bpf.h source code [linux/include/uapi/linux/bpf.h]

1	/ SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note /
2	/ Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com*
3	*
4	* This program is free software; you can redistribute it and/or
5	* modify it under the terms of version 2 of the GNU General Public
6	* License as published by the Free Software Foundation.
7	*/
8	#ifndef _UAPI__LINUX_BPF_H__
9	#define _UAPI__LINUX_BPF_H__
10
11	#include <linux/types.h>
12	#include <linux/bpf_common.h>
13
14	/ Extended instruction set based on top of classic BPF /
15
16	/ instruction classes /
17	#define BPF_JMP32 0x06 /* jmp mode in word width */
18	#define BPF_ALU64 0x07 /* alu mode in double word width */
19
20	/ ld/ldx fields /
21	#define BPF_DW 0x18 /* double word (64-bit) */
22	#define BPF_MEMSX 0x80 /* load with sign extension */
23	#define BPF_ATOMIC 0xc0 /* atomic memory ops - op type in immediate */
24	#define BPF_XADD 0xc0 /* exclusive add - legacy name */
25
26	/ alu/jmp fields /
27	#define BPF_MOV 0xb0 /* mov reg to reg */
28	#define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */
29
30	/ change endianness of a register /
31	#define BPF_END 0xd0 /* flags for endianness conversion: */
32	#define BPF_TO_LE 0x00 /* convert to little-endian */
33	#define BPF_TO_BE 0x08 /* convert to big-endian */
34	#define BPF_FROM_LE BPF_TO_LE
35	#define BPF_FROM_BE BPF_TO_BE
36
37	/ jmp encodings /
38	#define BPF_JNE 0x50 /* jump != */
39	#define BPF_JLT 0xa0 /* LT is unsigned, '<' */
40	#define BPF_JLE 0xb0 /* LE is unsigned, '<=' */
41	#define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */
42	#define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */
43	#define BPF_JSLT 0xc0 /* SLT is signed, '<' */
44	#define BPF_JSLE 0xd0 /* SLE is signed, '<=' */
45	#define BPF_CALL 0x80 /* function call */
46	#define BPF_EXIT 0x90 /* function return */
47
48	/ atomic op type fields (stored in immediate) /
49	#define BPF_FETCH 0x01 /* not an opcode on its own, used to build others */
50	#define BPF_XCHG (0xe0 \| BPF_FETCH) /* atomic exchange */
51	#define BPF_CMPXCHG (0xf0 \| BPF_FETCH) /* atomic compare-and-write */
52
53	/ Register numbers /
54	enum {
55	BPF_REG_0 = `0`,
56	BPF_REG_1,
57	BPF_REG_2,
58	BPF_REG_3,
59	BPF_REG_4,
60	BPF_REG_5,
61	BPF_REG_6,
62	BPF_REG_7,
63	BPF_REG_8,
64	BPF_REG_9,
65	BPF_REG_10,
66	__MAX_BPF_REG,
67	};
68
69	/ BPF has 10 general purpose 64-bit registers and stack frame. /
70	#define MAX_BPF_REG __MAX_BPF_REG
71
72	struct bpf_insn {
73	__u8 code; / opcode /
74	__u8 dst_reg:`4`; / dest register /
75	__u8 src_reg:`4`; / source register /
76	__s16 off; / signed offset /
77	__s32 imm; / signed immediate constant /
78	};
79
80	/ Key of an a BPF_MAP_TYPE_LPM_TRIE entry /
81	struct bpf_lpm_trie_key {
82	__u32 prefixlen; / up to 32 for AF_INET, 128 for AF_INET6 /
83	__u8 data[`0`]; / Arbitrary size /
84	};
85
86	struct bpf_cgroup_storage_key {
87	__u64 cgroup_inode_id; / cgroup inode id /
88	__u32 attach_type; / program attach type (enum bpf_attach_type) /
89	};
90
91	enum bpf_cgroup_iter_order {
92	BPF_CGROUP_ITER_ORDER_UNSPEC = `0`,
93	BPF_CGROUP_ITER_SELF_ONLY, / process only a single object. /
94	BPF_CGROUP_ITER_DESCENDANTS_PRE, / walk descendants in pre-order. /
95	BPF_CGROUP_ITER_DESCENDANTS_POST, / walk descendants in post-order. /
96	BPF_CGROUP_ITER_ANCESTORS_UP, / walk ancestors upward. /
97	};
98
99	union bpf_iter_link_info {
100	struct {
101	__u32 map_fd;
102	} map;
103	struct {
104	enum bpf_cgroup_iter_order order;
105
106	/ At most one of cgroup_fd and cgroup_id can be non-zero. If*
107	* both are zero, the walk starts from the default cgroup v2
108	* root. For walking v1 hierarchy, one should always explicitly
109	* specify cgroup_fd.
110	*/
111	__u32 cgroup_fd;
112	__u64 cgroup_id;
113	} cgroup;
114	/ Parameters of task iterators. /
115	struct {
116	__u32 tid;
117	__u32 pid;
118	__u32 pid_fd;
119	} task;
120	};
121
122	/ BPF syscall commands, see bpf(2) man-page for more details. /
123	/**
124	* DOC: eBPF Syscall Preamble
125	*
126	* The operation to be performed by the bpf\ () system call is determined
127	* by the cmd argument. Each operation takes an accompanying argument,
128	* provided via attr, which is a pointer to a union of type bpf_attr (see
129	* below). The size argument is the size of the union pointed to by attr.
130	*/
131	/**
132	* DOC: eBPF Syscall Commands
133	*
134	* BPF_MAP_CREATE
135	* Description
136	* Create a map and return a file descriptor that refers to the
137	* map. The close-on-exec file descriptor flag (see fcntl\ (2))
138	* is automatically enabled for the new file descriptor.
139	*
140	* Applying close\ (2) to the file descriptor returned by
141	* BPF_MAP_CREATE will delete the map (but see NOTES).
142	*
143	* Return
144	* A new file descriptor (a nonnegative integer), or -1 if an
145	* error occurred (in which case, errno is set appropriately).
146	*
147	* BPF_MAP_LOOKUP_ELEM
148	* Description
149	* Look up an element with a given key in the map referred to
150	* by the file descriptor map_fd.
151	*
152	* The flags argument may be specified as one of the
153	* following:
154	*
155	* BPF_F_LOCK
156	* Look up the value of a spin-locked map without
157	* returning the lock. This must be specified if the
158	* elements contain a spinlock.
159	*
160	* Return
161	* Returns zero on success. On error, -1 is returned and errno
162	* is set appropriately.
163	*
164	* BPF_MAP_UPDATE_ELEM
165	* Description
166	* Create or update an element (key/value pair) in a specified map.
167	*
168	* The flags argument should be specified as one of the
169	* following:
170	*
171	* BPF_ANY
172	* Create a new element or update an existing element.
173	* BPF_NOEXIST
174	* Create a new element only if it did not exist.
175	* BPF_EXIST
176	* Update an existing element.
177	* BPF_F_LOCK
178	* Update a spin_lock-ed map element.
179	*
180	* Return
181	* Returns zero on success. On error, -1 is returned and errno
182	* is set appropriately.
183	*
184	* May set errno to EINVAL, EPERM, ENOMEM,
185	* E2BIG, EEXIST, or ENOENT.
186	*
187	* E2BIG
188	* The number of elements in the map reached the
189	* max_entries limit specified at map creation time.
190	* EEXIST
191	* If flags specifies BPF_NOEXIST and the element
192	* with key already exists in the map.
193	* ENOENT
194	* If flags specifies BPF_EXIST and the element with
195	* key does not exist in the map.
196	*
197	* BPF_MAP_DELETE_ELEM
198	* Description
199	* Look up and delete an element by key in a specified map.
200	*
201	* Return
202	* Returns zero on success. On error, -1 is returned and errno
203	* is set appropriately.
204	*
205	* BPF_MAP_GET_NEXT_KEY
206	* Description
207	* Look up an element by key in a specified map and return the key
208	* of the next element. Can be used to iterate over all elements
209	* in the map.
210	*
211	* Return
212	* Returns zero on success. On error, -1 is returned and errno
213	* is set appropriately.
214	*
215	* The following cases can be used to iterate over all elements of
216	* the map:
217	*
218	* * If key is not found, the operation returns zero and sets
219	* the next_key pointer to the key of the first element.
220	* * If key is found, the operation returns zero and sets the
221	* next_key pointer to the key of the next element.
222	* * If key is the last element, returns -1 and errno is set
223	* to ENOENT.
224	*
225	* May set errno to ENOMEM, EFAULT, EPERM, or
226	* EINVAL on error.
227	*
228	* BPF_PROG_LOAD
229	* Description
230	* Verify and load an eBPF program, returning a new file
231	* descriptor associated with the program.
232	*
233	* Applying close\ (2) to the file descriptor returned by
234	* BPF_PROG_LOAD will unload the eBPF program (but see NOTES).
235	*
236	* The close-on-exec file descriptor flag (see fcntl\ (2)) is
237	* automatically enabled for the new file descriptor.
238	*
239	* Return
240	* A new file descriptor (a nonnegative integer), or -1 if an
241	* error occurred (in which case, errno is set appropriately).
242	*
243	* BPF_OBJ_PIN
244	* Description
245	* Pin an eBPF program or map referred by the specified bpf_fd
246	* to the provided pathname on the filesystem.
247	*
248	* The pathname argument must not contain a dot (".").
249	*
250	* On success, pathname retains a reference to the eBPF object,
251	* preventing deallocation of the object when the original
252	* bpf_fd is closed. This allow the eBPF object to live beyond
253	* close\ (\ bpf_fd\ ), and hence the lifetime of the parent
254	* process.
255	*
256	* Applying unlink\ (2) or similar calls to the pathname
257	* unpins the object from the filesystem, removing the reference.
258	* If no other file descriptors or filesystem nodes refer to the
259	* same object, it will be deallocated (see NOTES).
260	*
261	* The filesystem type for the parent directory of pathname must
262	* be BPF_FS_MAGIC.
263	*
264	* Return
265	* Returns zero on success. On error, -1 is returned and errno
266	* is set appropriately.
267	*
268	* BPF_OBJ_GET
269	* Description
270	* Open a file descriptor for the eBPF object pinned to the
271	* specified pathname.
272	*
273	* Return
274	* A new file descriptor (a nonnegative integer), or -1 if an
275	* error occurred (in which case, errno is set appropriately).
276	*
277	* BPF_PROG_ATTACH
278	* Description
279	* Attach an eBPF program to a target_fd at the specified
280	* attach_type hook.
281	*
282	* The attach_type specifies the eBPF attachment point to
283	* attach the program to, and must be one of bpf_attach_type
284	* (see below).
285	*
286	* The attach_bpf_fd must be a valid file descriptor for a
287	* loaded eBPF program of a cgroup, flow dissector, LIRC, sockmap
288	* or sock_ops type corresponding to the specified attach_type.
289	*
290	* The target_fd must be a valid file descriptor for a kernel
291	* object which depends on the attach type of attach_bpf_fd:
292	*
293	* BPF_PROG_TYPE_CGROUP_DEVICE,
294	* BPF_PROG_TYPE_CGROUP_SKB,
295	* BPF_PROG_TYPE_CGROUP_SOCK,
296	* BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
297	* BPF_PROG_TYPE_CGROUP_SOCKOPT,
298	* BPF_PROG_TYPE_CGROUP_SYSCTL,
299	* BPF_PROG_TYPE_SOCK_OPS
300	*
301	* Control Group v2 hierarchy with the eBPF controller
302	* enabled. Requires the kernel to be compiled with
303	* CONFIG_CGROUP_BPF.
304	*
305	* BPF_PROG_TYPE_FLOW_DISSECTOR
306	*
307	* Network namespace (eg /proc/self/ns/net).
308	*
309	* BPF_PROG_TYPE_LIRC_MODE2
310	*
311	* LIRC device path (eg /dev/lircN). Requires the kernel
312	* to be compiled with CONFIG_BPF_LIRC_MODE2.
313	*
314	* BPF_PROG_TYPE_SK_SKB,
315	* BPF_PROG_TYPE_SK_MSG
316	*
317	* eBPF map of socket type (eg BPF_MAP_TYPE_SOCKHASH).
318	*
319	* Return
320	* Returns zero on success. On error, -1 is returned and errno
321	* is set appropriately.
322	*
323	* BPF_PROG_DETACH
324	* Description
325	* Detach the eBPF program associated with the target_fd at the
326	* hook specified by attach_type. The program must have been
327	* previously attached using BPF_PROG_ATTACH.
328	*
329	* Return
330	* Returns zero on success. On error, -1 is returned and errno
331	* is set appropriately.
332	*
333	* BPF_PROG_TEST_RUN
334	* Description
335	* Run the eBPF program associated with the prog_fd a repeat
336	* number of times against a provided program context ctx_in and
337	* data data_in, and return the modified program context
338	* ctx_out, data_out (for example, packet data), result of the
339	* execution retval, and duration of the test run.
340	*
341	* The sizes of the buffers provided as input and output
342	* parameters ctx_in, ctx_out, data_in, and data_out must
343	* be provided in the corresponding variables ctx_size_in,
344	* ctx_size_out, data_size_in, and/or data_size_out. If any
345	* of these parameters are not provided (ie set to NULL), the
346	* corresponding size field must be zero.
347	*
348	* Some program types have particular requirements:
349	*
350	* BPF_PROG_TYPE_SK_LOOKUP
351	* data_in and data_out must be NULL.
352	*
353	* BPF_PROG_TYPE_RAW_TRACEPOINT,
354	* BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE
355	*
356	* ctx_out, data_in and data_out must be NULL.
357	* repeat must be zero.
358	*
359	* BPF_PROG_RUN is an alias for BPF_PROG_TEST_RUN.
360	*
361	* Return
362	* Returns zero on success. On error, -1 is returned and errno
363	* is set appropriately.
364	*
365	* ENOSPC
366	* Either data_size_out or ctx_size_out is too small.
367	* ENOTSUPP
368	* This command is not supported by the program type of
369	* the program referred to by prog_fd.
370	*
371	* BPF_PROG_GET_NEXT_ID
372	* Description
373	* Fetch the next eBPF program currently loaded into the kernel.
374	*
375	* Looks for the eBPF program with an id greater than start_id
376	* and updates next_id on success. If no other eBPF programs
377	* remain with ids higher than start_id, returns -1 and sets
378	* errno to ENOENT.
379	*
380	* Return
381	* Returns zero on success. On error, or when no id remains, -1
382	* is returned and errno is set appropriately.
383	*
384	* BPF_MAP_GET_NEXT_ID
385	* Description
386	* Fetch the next eBPF map currently loaded into the kernel.
387	*
388	* Looks for the eBPF map with an id greater than start_id
389	* and updates next_id on success. If no other eBPF maps
390	* remain with ids higher than start_id, returns -1 and sets
391	* errno to ENOENT.
392	*
393	* Return
394	* Returns zero on success. On error, or when no id remains, -1
395	* is returned and errno is set appropriately.
396	*
397	* BPF_PROG_GET_FD_BY_ID
398	* Description
399	* Open a file descriptor for the eBPF program corresponding to
400	* prog_id.
401	*
402	* Return
403	* A new file descriptor (a nonnegative integer), or -1 if an
404	* error occurred (in which case, errno is set appropriately).
405	*
406	* BPF_MAP_GET_FD_BY_ID
407	* Description
408	* Open a file descriptor for the eBPF map corresponding to
409	* map_id.
410	*
411	* Return
412	* A new file descriptor (a nonnegative integer), or -1 if an
413	* error occurred (in which case, errno is set appropriately).
414	*
415	* BPF_OBJ_GET_INFO_BY_FD
416	* Description
417	* Obtain information about the eBPF object corresponding to
418	* bpf_fd.
419	*
420	* Populates up to info_len bytes of info, which will be in
421	* one of the following formats depending on the eBPF object type
422	* of bpf_fd:
423	*
424	* * struct bpf_prog_info
425	* * struct bpf_map_info
426	* * struct bpf_btf_info
427	* * struct bpf_link_info
428	*
429	* Return
430	* Returns zero on success. On error, -1 is returned and errno
431	* is set appropriately.
432	*
433	* BPF_PROG_QUERY
434	* Description
435	* Obtain information about eBPF programs associated with the
436	* specified attach_type hook.
437	*
438	* The target_fd must be a valid file descriptor for a kernel
439	* object which depends on the attach type of attach_bpf_fd:
440	*
441	* BPF_PROG_TYPE_CGROUP_DEVICE,
442	* BPF_PROG_TYPE_CGROUP_SKB,
443	* BPF_PROG_TYPE_CGROUP_SOCK,
444	* BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
445	* BPF_PROG_TYPE_CGROUP_SOCKOPT,
446	* BPF_PROG_TYPE_CGROUP_SYSCTL,
447	* BPF_PROG_TYPE_SOCK_OPS
448	*
449	* Control Group v2 hierarchy with the eBPF controller
450	* enabled. Requires the kernel to be compiled with
451	* CONFIG_CGROUP_BPF.
452	*
453	* BPF_PROG_TYPE_FLOW_DISSECTOR
454	*
455	* Network namespace (eg /proc/self/ns/net).
456	*
457	* BPF_PROG_TYPE_LIRC_MODE2
458	*
459	* LIRC device path (eg /dev/lircN). Requires the kernel
460	* to be compiled with CONFIG_BPF_LIRC_MODE2.
461	*
462	* BPF_PROG_QUERY always fetches the number of programs
463	* attached and the attach_flags which were used to attach those
464	* programs. Additionally, if prog_ids is nonzero and the number
465	* of attached programs is less than prog_cnt, populates
466	* prog_ids with the eBPF program ids of the programs attached
467	* at target_fd.
468	*
469	* The following flags may alter the result:
470	*
471	* BPF_F_QUERY_EFFECTIVE
472	* Only return information regarding programs which are
473	* currently effective at the specified target_fd.
474	*
475	* Return
476	* Returns zero on success. On error, -1 is returned and errno
477	* is set appropriately.
478	*
479	* BPF_RAW_TRACEPOINT_OPEN
480	* Description
481	* Attach an eBPF program to a tracepoint name to access kernel
482	* internal arguments of the tracepoint in their raw form.
483	*
484	* The prog_fd must be a valid file descriptor associated with
485	* a loaded eBPF program of type BPF_PROG_TYPE_RAW_TRACEPOINT.
486	*
487	* No ABI guarantees are made about the content of tracepoint
488	* arguments exposed to the corresponding eBPF program.
489	*
490	* Applying close\ (2) to the file descriptor returned by
491	* BPF_RAW_TRACEPOINT_OPEN will delete the map (but see NOTES).
492	*
493	* Return
494	* A new file descriptor (a nonnegative integer), or -1 if an
495	* error occurred (in which case, errno is set appropriately).
496	*
497	* BPF_BTF_LOAD
498	* Description
499	* Verify and load BPF Type Format (BTF) metadata into the kernel,
500	* returning a new file descriptor associated with the metadata.
501	* BTF is described in more detail at
502	* https://www.kernel.org/doc/html/latest/bpf/btf.html.
503	*
504	* The btf parameter must point to valid memory providing
505	* btf_size bytes of BTF binary metadata.
506	*
507	* The returned file descriptor can be passed to other bpf\ ()
508	* subcommands such as BPF_PROG_LOAD or BPF_MAP_CREATE to
509	* associate the BTF with those objects.
510	*
511	* Similar to BPF_PROG_LOAD, BPF_BTF_LOAD has optional
512	* parameters to specify a btf_log_buf, btf_log_size and
513	* btf_log_level which allow the kernel to return freeform log
514	* output regarding the BTF verification process.
515	*
516	* Return
517	* A new file descriptor (a nonnegative integer), or -1 if an
518	* error occurred (in which case, errno is set appropriately).
519	*
520	* BPF_BTF_GET_FD_BY_ID
521	* Description
522	* Open a file descriptor for the BPF Type Format (BTF)
523	* corresponding to btf_id.
524	*
525	* Return
526	* A new file descriptor (a nonnegative integer), or -1 if an
527	* error occurred (in which case, errno is set appropriately).
528	*
529	* BPF_TASK_FD_QUERY
530	* Description
531	* Obtain information about eBPF programs associated with the
532	* target process identified by pid and fd.
533	*
534	* If the pid and fd are associated with a tracepoint, kprobe
535	* or uprobe perf event, then the prog_id and fd_type will
536	* be populated with the eBPF program id and file descriptor type
537	* of type bpf_task_fd_type. If associated with a kprobe or
538	* uprobe, the probe_offset and probe_addr will also be
539	* populated. Optionally, if buf is provided, then up to
540	* buf_len bytes of buf will be populated with the name of
541	* the tracepoint, kprobe or uprobe.
542	*
543	* The resulting prog_id may be introspected in deeper detail
544	* using BPF_PROG_GET_FD_BY_ID and BPF_OBJ_GET_INFO_BY_FD.
545	*
546	* Return
547	* Returns zero on success. On error, -1 is returned and errno
548	* is set appropriately.
549	*
550	* BPF_MAP_LOOKUP_AND_DELETE_ELEM
551	* Description
552	* Look up an element with the given key in the map referred to
553	* by the file descriptor fd, and if found, delete the element.
554	*
555	* For BPF_MAP_TYPE_QUEUE and BPF_MAP_TYPE_STACK map
556	* types, the flags argument needs to be set to 0, but for other
557	* map types, it may be specified as:
558	*
559	* BPF_F_LOCK
560	* Look up and delete the value of a spin-locked map
561	* without returning the lock. This must be specified if
562	* the elements contain a spinlock.
563	*
564	* The BPF_MAP_TYPE_QUEUE and BPF_MAP_TYPE_STACK map types
565	* implement this command as a "pop" operation, deleting the top
566	* element rather than one corresponding to key.
567	* The key and key_len parameters should be zeroed when
568	* issuing this operation for these map types.
569	*
570	* This command is only valid for the following map types:
571	* * BPF_MAP_TYPE_QUEUE
572	* * BPF_MAP_TYPE_STACK
573	* * BPF_MAP_TYPE_HASH
574	* * BPF_MAP_TYPE_PERCPU_HASH
575	* * BPF_MAP_TYPE_LRU_HASH
576	* * BPF_MAP_TYPE_LRU_PERCPU_HASH
577	*
578	* Return
579	* Returns zero on success. On error, -1 is returned and errno
580	* is set appropriately.
581	*
582	* BPF_MAP_FREEZE
583	* Description
584	* Freeze the permissions of the specified map.
585	*
586	* Write permissions may be frozen by passing zero flags.
587	* Upon success, no future syscall invocations may alter the
588	* map state of map_fd. Write operations from eBPF programs
589	* are still possible for a frozen map.
590	*
591	* Not supported for maps of type BPF_MAP_TYPE_STRUCT_OPS.
592	*
593	* Return
594	* Returns zero on success. On error, -1 is returned and errno
595	* is set appropriately.
596	*
597	* BPF_BTF_GET_NEXT_ID
598	* Description
599	* Fetch the next BPF Type Format (BTF) object currently loaded
600	* into the kernel.
601	*
602	* Looks for the BTF object with an id greater than start_id
603	* and updates next_id on success. If no other BTF objects
604	* remain with ids higher than start_id, returns -1 and sets
605	* errno to ENOENT.
606	*
607	* Return
608	* Returns zero on success. On error, or when no id remains, -1
609	* is returned and errno is set appropriately.
610	*
611	* BPF_MAP_LOOKUP_BATCH
612	* Description
613	* Iterate and fetch multiple elements in a map.
614	*
615	* Two opaque values are used to manage batch operations,
616	* in_batch and out_batch. Initially, in_batch must be set
617	* to NULL to begin the batched operation. After each subsequent
618	* BPF_MAP_LOOKUP_BATCH, the caller should pass the resultant
619	* out_batch as the in_batch for the next operation to
620	* continue iteration from the current point.
621	*
622	* The keys and values are output parameters which must point
623	* to memory large enough to hold count items based on the key
624	* and value size of the map map_fd. The keys buffer must be
625	* of key_size * count. The values buffer must be of
626	* value_size * count.
627	*
628	* The elem_flags argument may be specified as one of the
629	* following:
630	*
631	* BPF_F_LOCK
632	* Look up the value of a spin-locked map without
633	* returning the lock. This must be specified if the
634	* elements contain a spinlock.
635	*
636	* On success, count elements from the map are copied into the
637	* user buffer, with the keys copied into keys and the values
638	* copied into the corresponding indices in values.
639	*
640	* If an error is returned and errno is not EFAULT, count
641	* is set to the number of successfully processed elements.
642	*
643	* Return
644	* Returns zero on success. On error, -1 is returned and errno
645	* is set appropriately.
646	*
647	* May set errno to ENOSPC to indicate that keys or
648	* values is too small to dump an entire bucket during
649	* iteration of a hash-based map type.
650	*
651	* BPF_MAP_LOOKUP_AND_DELETE_BATCH
652	* Description
653	* Iterate and delete all elements in a map.
654	*
655	* This operation has the same behavior as
656	* BPF_MAP_LOOKUP_BATCH with two exceptions:
657	*
658	* * Every element that is successfully returned is also deleted
659	* from the map. This is at least count elements. Note that
660	* count is both an input and an output parameter.
661	* * Upon returning with errno set to EFAULT, up to
662	* count elements may be deleted without returning the keys
663	* and values of the deleted elements.
664	*
665	* Return
666	* Returns zero on success. On error, -1 is returned and errno
667	* is set appropriately.
668	*
669	* BPF_MAP_UPDATE_BATCH
670	* Description
671	* Update multiple elements in a map by key.
672	*
673	* The keys and values are input parameters which must point
674	* to memory large enough to hold count items based on the key
675	* and value size of the map map_fd. The keys buffer must be
676	* of key_size * count. The values buffer must be of
677	* value_size * count.
678	*
679	* Each element specified in keys is sequentially updated to the
680	* value in the corresponding index in values. The in_batch
681	* and out_batch parameters are ignored and should be zeroed.
682	*
683	* The elem_flags argument should be specified as one of the
684	* following:
685	*
686	* BPF_ANY
687	* Create new elements or update a existing elements.
688	* BPF_NOEXIST
689	* Create new elements only if they do not exist.
690	* BPF_EXIST
691	* Update existing elements.
692	* BPF_F_LOCK
693	* Update spin_lock-ed map elements. This must be
694	* specified if the map value contains a spinlock.
695	*
696	* On success, count elements from the map are updated.
697	*
698	* If an error is returned and errno is not EFAULT, count
699	* is set to the number of successfully processed elements.
700	*
701	* Return
702	* Returns zero on success. On error, -1 is returned and errno
703	* is set appropriately.
704	*
705	* May set errno to EINVAL, EPERM, ENOMEM, or
706	* E2BIG. E2BIG indicates that the number of elements in
707	* the map reached the max_entries limit specified at map
708	* creation time.
709	*
710	* May set errno to one of the following error codes under
711	* specific circumstances:
712	*
713	* EEXIST
714	* If flags specifies BPF_NOEXIST and the element
715	* with key already exists in the map.
716	* ENOENT
717	* If flags specifies BPF_EXIST and the element with
718	* key does not exist in the map.
719	*
720	* BPF_MAP_DELETE_BATCH
721	* Description
722	* Delete multiple elements in a map by key.
723	*
724	* The keys parameter is an input parameter which must point
725	* to memory large enough to hold count items based on the key
726	* size of the map map_fd, that is, key_size * count.
727	*
728	* Each element specified in keys is sequentially deleted. The
729	* in_batch, out_batch, and values parameters are ignored
730	* and should be zeroed.
731	*
732	* The elem_flags argument may be specified as one of the
733	* following:
734	*
735	* BPF_F_LOCK
736	* Look up the value of a spin-locked map without
737	* returning the lock. This must be specified if the
738	* elements contain a spinlock.
739	*
740	* On success, count elements from the map are updated.
741	*
742	* If an error is returned and errno is not EFAULT, count
743	* is set to the number of successfully processed elements. If
744	* errno is EFAULT, up to count elements may be been
745	* deleted.
746	*
747	* Return
748	* Returns zero on success. On error, -1 is returned and errno
749	* is set appropriately.
750	*
751	* BPF_LINK_CREATE
752	* Description
753	* Attach an eBPF program to a target_fd at the specified
754	* attach_type hook and return a file descriptor handle for
755	* managing the link.
756	*
757	* Return
758	* A new file descriptor (a nonnegative integer), or -1 if an
759	* error occurred (in which case, errno is set appropriately).
760	*
761	* BPF_LINK_UPDATE
762	* Description
763	* Update the eBPF program in the specified link_fd to
764	* new_prog_fd.
765	*
766	* Return
767	* Returns zero on success. On error, -1 is returned and errno
768	* is set appropriately.
769	*
770	* BPF_LINK_GET_FD_BY_ID
771	* Description
772	* Open a file descriptor for the eBPF Link corresponding to
773	* link_id.
774	*
775	* Return
776	* A new file descriptor (a nonnegative integer), or -1 if an
777	* error occurred (in which case, errno is set appropriately).
778	*
779	* BPF_LINK_GET_NEXT_ID
780	* Description
781	* Fetch the next eBPF link currently loaded into the kernel.
782	*
783	* Looks for the eBPF link with an id greater than start_id
784	* and updates next_id on success. If no other eBPF links
785	* remain with ids higher than start_id, returns -1 and sets
786	* errno to ENOENT.
787	*
788	* Return
789	* Returns zero on success. On error, or when no id remains, -1
790	* is returned and errno is set appropriately.
791	*
792	* BPF_ENABLE_STATS
793	* Description
794	* Enable eBPF runtime statistics gathering.
795	*
796	* Runtime statistics gathering for the eBPF runtime is disabled
797	* by default to minimize the corresponding performance overhead.
798	* This command enables statistics globally.
799	*
800	* Multiple programs may independently enable statistics.
801	* After gathering the desired statistics, eBPF runtime statistics
802	* may be disabled again by calling close\ (2) for the file
803	* descriptor returned by this function. Statistics will only be
804	* disabled system-wide when all outstanding file descriptors
805	* returned by prior calls for this subcommand are closed.
806	*
807	* Return
808	* A new file descriptor (a nonnegative integer), or -1 if an
809	* error occurred (in which case, errno is set appropriately).
810	*
811	* BPF_ITER_CREATE
812	* Description
813	* Create an iterator on top of the specified link_fd (as
814	* previously created using BPF_LINK_CREATE) and return a
815	* file descriptor that can be used to trigger the iteration.
816	*
817	* If the resulting file descriptor is pinned to the filesystem
818	* using BPF_OBJ_PIN, then subsequent read\ (2) syscalls
819	* for that path will trigger the iterator to read kernel state
820	* using the eBPF program attached to link_fd.
821	*
822	* Return
823	* A new file descriptor (a nonnegative integer), or -1 if an
824	* error occurred (in which case, errno is set appropriately).
825	*
826	* BPF_LINK_DETACH
827	* Description
828	* Forcefully detach the specified link_fd from its
829	* corresponding attachment point.
830	*
831	* Return
832	* Returns zero on success. On error, -1 is returned and errno
833	* is set appropriately.
834	*
835	* BPF_PROG_BIND_MAP
836	* Description
837	* Bind a map to the lifetime of an eBPF program.
838	*
839	* The map identified by map_fd is bound to the program
840	* identified by prog_fd and only released when prog_fd is
841	* released. This may be used in cases where metadata should be
842	* associated with a program which otherwise does not contain any
843	* references to the map (for example, embedded in the eBPF
844	* program instructions).
845	*
846	* Return
847	* Returns zero on success. On error, -1 is returned and errno
848	* is set appropriately.
849	*
850	* NOTES
851	* eBPF objects (maps and programs) can be shared between processes.
852	*
853	* * After fork\ (2), the child inherits file descriptors
854	* referring to the same eBPF objects.
855	* * File descriptors referring to eBPF objects can be transferred over
856	* unix\ (7) domain sockets.
857	* * File descriptors referring to eBPF objects can be duplicated in the
858	* usual way, using dup\ (2) and similar calls.
859	* * File descriptors referring to eBPF objects can be pinned to the
860	* filesystem using the BPF_OBJ_PIN command of bpf\ (2).
861	*
862	* An eBPF object is deallocated only after all file descriptors referring
863	* to the object have been closed and no references remain pinned to the
864	* filesystem or attached (for example, bound to a program or device).
865	*/
866	enum bpf_cmd {
867	BPF_MAP_CREATE,
868	BPF_MAP_LOOKUP_ELEM,
869	BPF_MAP_UPDATE_ELEM,
870	BPF_MAP_DELETE_ELEM,
871	BPF_MAP_GET_NEXT_KEY,
872	BPF_PROG_LOAD,
873	BPF_OBJ_PIN,
874	BPF_OBJ_GET,
875	BPF_PROG_ATTACH,
876	BPF_PROG_DETACH,
877	BPF_PROG_TEST_RUN,
878	BPF_PROG_RUN = BPF_PROG_TEST_RUN,
879	BPF_PROG_GET_NEXT_ID,
880	BPF_MAP_GET_NEXT_ID,
881	BPF_PROG_GET_FD_BY_ID,
882	BPF_MAP_GET_FD_BY_ID,
883	BPF_OBJ_GET_INFO_BY_FD,
884	BPF_PROG_QUERY,
885	BPF_RAW_TRACEPOINT_OPEN,
886	BPF_BTF_LOAD,
887	BPF_BTF_GET_FD_BY_ID,
888	BPF_TASK_FD_QUERY,
889	BPF_MAP_LOOKUP_AND_DELETE_ELEM,
890	BPF_MAP_FREEZE,
891	BPF_BTF_GET_NEXT_ID,
892	BPF_MAP_LOOKUP_BATCH,
893	BPF_MAP_LOOKUP_AND_DELETE_BATCH,
894	BPF_MAP_UPDATE_BATCH,
895	BPF_MAP_DELETE_BATCH,
896	BPF_LINK_CREATE,
897	BPF_LINK_UPDATE,
898	BPF_LINK_GET_FD_BY_ID,
899	BPF_LINK_GET_NEXT_ID,
900	BPF_ENABLE_STATS,
901	BPF_ITER_CREATE,
902	BPF_LINK_DETACH,
903	BPF_PROG_BIND_MAP,
904	};
905
906	enum bpf_map_type {
907	BPF_MAP_TYPE_UNSPEC,
908	BPF_MAP_TYPE_HASH,
909	BPF_MAP_TYPE_ARRAY,
910	BPF_MAP_TYPE_PROG_ARRAY,
911	BPF_MAP_TYPE_PERF_EVENT_ARRAY,
912	BPF_MAP_TYPE_PERCPU_HASH,
913	BPF_MAP_TYPE_PERCPU_ARRAY,
914	BPF_MAP_TYPE_STACK_TRACE,
915	BPF_MAP_TYPE_CGROUP_ARRAY,
916	BPF_MAP_TYPE_LRU_HASH,
917	BPF_MAP_TYPE_LRU_PERCPU_HASH,
918	BPF_MAP_TYPE_LPM_TRIE,
919	BPF_MAP_TYPE_ARRAY_OF_MAPS,
920	BPF_MAP_TYPE_HASH_OF_MAPS,
921	BPF_MAP_TYPE_DEVMAP,
922	BPF_MAP_TYPE_SOCKMAP,
923	BPF_MAP_TYPE_CPUMAP,
924	BPF_MAP_TYPE_XSKMAP,
925	BPF_MAP_TYPE_SOCKHASH,
926	BPF_MAP_TYPE_CGROUP_STORAGE_DEPRECATED,
927	/ BPF_MAP_TYPE_CGROUP_STORAGE is available to bpf programs attaching*
928	* to a cgroup. The newer BPF_MAP_TYPE_CGRP_STORAGE is available to
929	* both cgroup-attached and other progs and supports all functionality
930	* provided by BPF_MAP_TYPE_CGROUP_STORAGE. So mark
931	* BPF_MAP_TYPE_CGROUP_STORAGE deprecated.
932	*/
933	BPF_MAP_TYPE_CGROUP_STORAGE = BPF_MAP_TYPE_CGROUP_STORAGE_DEPRECATED,
934	BPF_MAP_TYPE_REUSEPORT_SOCKARRAY,
935	BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE_DEPRECATED,
936	/ BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE is available to bpf programs*
937	* attaching to a cgroup. The new mechanism (BPF_MAP_TYPE_CGRP_STORAGE +
938	* local percpu kptr) supports all BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE
939	* functionality and more. So mark * BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE
940	* deprecated.
941	*/
942	BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE = BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE_DEPRECATED,
943	BPF_MAP_TYPE_QUEUE,
944	BPF_MAP_TYPE_STACK,
945	BPF_MAP_TYPE_SK_STORAGE,
946	BPF_MAP_TYPE_DEVMAP_HASH,
947	BPF_MAP_TYPE_STRUCT_OPS,
948	BPF_MAP_TYPE_RINGBUF,
949	BPF_MAP_TYPE_INODE_STORAGE,
950	BPF_MAP_TYPE_TASK_STORAGE,
951	BPF_MAP_TYPE_BLOOM_FILTER,
952	BPF_MAP_TYPE_USER_RINGBUF,
953	BPF_MAP_TYPE_CGRP_STORAGE,
954	};
955
956	/ Note that tracing related programs such as*
957	* BPF_PROG_TYPE_{KPROBE,TRACEPOINT,PERF_EVENT,RAW_TRACEPOINT}
958	* are not subject to a stable API since kernel internal data
959	* structures can change from release to release and may
960	* therefore break existing tracing BPF programs. Tracing BPF
961	* programs correspond to /a/ specific kernel which is to be
962	* analyzed, and not /a/ specific kernel /and/ all future ones.
963	*/
964	enum bpf_prog_type {
965	BPF_PROG_TYPE_UNSPEC,
966	BPF_PROG_TYPE_SOCKET_FILTER,
967	BPF_PROG_TYPE_KPROBE,
968	BPF_PROG_TYPE_SCHED_CLS,
969	BPF_PROG_TYPE_SCHED_ACT,
970	BPF_PROG_TYPE_TRACEPOINT,
971	BPF_PROG_TYPE_XDP,
972	BPF_PROG_TYPE_PERF_EVENT,
973	BPF_PROG_TYPE_CGROUP_SKB,
974	BPF_PROG_TYPE_CGROUP_SOCK,
975	BPF_PROG_TYPE_LWT_IN,
976	BPF_PROG_TYPE_LWT_OUT,
977	BPF_PROG_TYPE_LWT_XMIT,
978	BPF_PROG_TYPE_SOCK_OPS,
979	BPF_PROG_TYPE_SK_SKB,
980	BPF_PROG_TYPE_CGROUP_DEVICE,
981	BPF_PROG_TYPE_SK_MSG,
982	BPF_PROG_TYPE_RAW_TRACEPOINT,
983	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
984	BPF_PROG_TYPE_LWT_SEG6LOCAL,
985	BPF_PROG_TYPE_LIRC_MODE2,
986	BPF_PROG_TYPE_SK_REUSEPORT,
987	BPF_PROG_TYPE_FLOW_DISSECTOR,
988	BPF_PROG_TYPE_CGROUP_SYSCTL,
989	BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
990	BPF_PROG_TYPE_CGROUP_SOCKOPT,
991	BPF_PROG_TYPE_TRACING,
992	BPF_PROG_TYPE_STRUCT_OPS,
993	BPF_PROG_TYPE_EXT,
994	BPF_PROG_TYPE_LSM,
995	BPF_PROG_TYPE_SK_LOOKUP,
996	BPF_PROG_TYPE_SYSCALL, / a program that can execute syscalls /
997	BPF_PROG_TYPE_NETFILTER,
998	};
999
1000	enum bpf_attach_type {
1001	BPF_CGROUP_INET_INGRESS,
1002	BPF_CGROUP_INET_EGRESS,
1003	BPF_CGROUP_INET_SOCK_CREATE,
1004	BPF_CGROUP_SOCK_OPS,
1005	BPF_SK_SKB_STREAM_PARSER,
1006	BPF_SK_SKB_STREAM_VERDICT,
1007	BPF_CGROUP_DEVICE,
1008	BPF_SK_MSG_VERDICT,
1009	BPF_CGROUP_INET4_BIND,
1010	BPF_CGROUP_INET6_BIND,
1011	BPF_CGROUP_INET4_CONNECT,
1012	BPF_CGROUP_INET6_CONNECT,
1013	BPF_CGROUP_INET4_POST_BIND,
1014	BPF_CGROUP_INET6_POST_BIND,
1015	BPF_CGROUP_UDP4_SENDMSG,
1016	BPF_CGROUP_UDP6_SENDMSG,
1017	BPF_LIRC_MODE2,
1018	BPF_FLOW_DISSECTOR,
1019	BPF_CGROUP_SYSCTL,
1020	BPF_CGROUP_UDP4_RECVMSG,
1021	BPF_CGROUP_UDP6_RECVMSG,
1022	BPF_CGROUP_GETSOCKOPT,
1023	BPF_CGROUP_SETSOCKOPT,
1024	BPF_TRACE_RAW_TP,
1025	BPF_TRACE_FENTRY,
1026	BPF_TRACE_FEXIT,
1027	BPF_MODIFY_RETURN,
1028	BPF_LSM_MAC,
1029	BPF_TRACE_ITER,
1030	BPF_CGROUP_INET4_GETPEERNAME,
1031	BPF_CGROUP_INET6_GETPEERNAME,
1032	BPF_CGROUP_INET4_GETSOCKNAME,
1033	BPF_CGROUP_INET6_GETSOCKNAME,
1034	BPF_XDP_DEVMAP,
1035	BPF_CGROUP_INET_SOCK_RELEASE,
1036	BPF_XDP_CPUMAP,
1037	BPF_SK_LOOKUP,
1038	BPF_XDP,
1039	BPF_SK_SKB_VERDICT,
1040	BPF_SK_REUSEPORT_SELECT,
1041	BPF_SK_REUSEPORT_SELECT_OR_MIGRATE,
1042	BPF_PERF_EVENT,
1043	BPF_TRACE_KPROBE_MULTI,
1044	BPF_LSM_CGROUP,
1045	BPF_STRUCT_OPS,
1046	BPF_NETFILTER,
1047	BPF_TCX_INGRESS,
1048	BPF_TCX_EGRESS,
1049	BPF_TRACE_UPROBE_MULTI,
1050	BPF_CGROUP_UNIX_CONNECT,
1051	BPF_CGROUP_UNIX_SENDMSG,
1052	BPF_CGROUP_UNIX_RECVMSG,
1053	BPF_CGROUP_UNIX_GETPEERNAME,
1054	BPF_CGROUP_UNIX_GETSOCKNAME,
1055	BPF_NETKIT_PRIMARY,
1056	BPF_NETKIT_PEER,
1057	__MAX_BPF_ATTACH_TYPE
1058	};
1059
1060	#define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE
1061
1062	enum bpf_link_type {
1063	BPF_LINK_TYPE_UNSPEC = `0`,
1064	BPF_LINK_TYPE_RAW_TRACEPOINT = `1`,
1065	BPF_LINK_TYPE_TRACING = `2`,
1066	BPF_LINK_TYPE_CGROUP = `3`,
1067	BPF_LINK_TYPE_ITER = `4`,
1068	BPF_LINK_TYPE_NETNS = `5`,
1069	BPF_LINK_TYPE_XDP = `6`,
1070	BPF_LINK_TYPE_PERF_EVENT = `7`,
1071	BPF_LINK_TYPE_KPROBE_MULTI = `8`,
1072	BPF_LINK_TYPE_STRUCT_OPS = `9`,
1073	BPF_LINK_TYPE_NETFILTER = `10`,
1074	BPF_LINK_TYPE_TCX = `11`,
1075	BPF_LINK_TYPE_UPROBE_MULTI = `12`,
1076	BPF_LINK_TYPE_NETKIT = `13`,
1077	MAX_BPF_LINK_TYPE,
1078	};
1079
1080	enum bpf_perf_event_type {
1081	BPF_PERF_EVENT_UNSPEC = `0`,
1082	BPF_PERF_EVENT_UPROBE = `1`,
1083	BPF_PERF_EVENT_URETPROBE = `2`,
1084	BPF_PERF_EVENT_KPROBE = `3`,
1085	BPF_PERF_EVENT_KRETPROBE = `4`,
1086	BPF_PERF_EVENT_TRACEPOINT = `5`,
1087	BPF_PERF_EVENT_EVENT = `6`,
1088	};
1089
1090	/ cgroup-bpf attach flags used in BPF_PROG_ATTACH command*
1091	*
1092	* NONE(default): No further bpf programs allowed in the subtree.
1093	*
1094	* BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program,
1095	* the program in this cgroup yields to sub-cgroup program.
1096	*
1097	* BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program,
1098	* that cgroup program gets run in addition to the program in this cgroup.
1099	*
1100	* Only one program is allowed to be attached to a cgroup with
1101	* NONE or BPF_F_ALLOW_OVERRIDE flag.
1102	* Attaching another program on top of NONE or BPF_F_ALLOW_OVERRIDE will
1103	* release old program and attach the new one. Attach flags has to match.
1104	*
1105	* Multiple programs are allowed to be attached to a cgroup with
1106	* BPF_F_ALLOW_MULTI flag. They are executed in FIFO order
1107	* (those that were attached first, run first)
1108	* The programs of sub-cgroup are executed first, then programs of
1109	* this cgroup and then programs of parent cgroup.
1110	* When children program makes decision (like picking TCP CA or sock bind)
1111	* parent program has a chance to override it.
1112	*
1113	* With BPF_F_ALLOW_MULTI a new program is added to the end of the list of
1114	* programs for a cgroup. Though it's possible to replace an old program at
1115	* any position by also specifying BPF_F_REPLACE flag and position itself in
1116	* replace_bpf_fd attribute. Old program at this position will be released.
1117	*
1118	* A cgroup with MULTI or OVERRIDE flag allows any attach flags in sub-cgroups.
1119	* A cgroup with NONE doesn't allow any programs in sub-cgroups.
1120	* Ex1:
1121	* cgrp1 (MULTI progs A, B) ->
1122	* cgrp2 (OVERRIDE prog C) ->
1123	* cgrp3 (MULTI prog D) ->
1124	* cgrp4 (OVERRIDE prog E) ->
1125	* cgrp5 (NONE prog F)
1126	* the event in cgrp5 triggers execution of F,D,A,B in that order.
1127	* if prog F is detached, the execution is E,D,A,B
1128	* if prog F and D are detached, the execution is E,A,B
1129	* if prog F, E and D are detached, the execution is C,A,B
1130	*
1131	* All eligible programs are executed regardless of return code from
1132	* earlier programs.
1133	*/
1134	#define BPF_F_ALLOW_OVERRIDE (1U << 0)
1135	#define BPF_F_ALLOW_MULTI (1U << 1)
1136	/ Generic attachment flags. /
1137	#define BPF_F_REPLACE (1U << 2)
1138	#define BPF_F_BEFORE (1U << 3)
1139	#define BPF_F_AFTER (1U << 4)
1140	#define BPF_F_ID (1U << 5)
1141	#define BPF_F_LINK BPF_F_LINK /* 1 << 13 */
1142
1143	/ If BPF_F_STRICT_ALIGNMENT is used in BPF_PROG_LOAD command, the*
1144	* verifier will perform strict alignment checking as if the kernel
1145	* has been built with CONFIG_EFFICIENT_UNALIGNED_ACCESS not set,
1146	* and NET_IP_ALIGN defined to 2.
1147	*/
1148	#define BPF_F_STRICT_ALIGNMENT (1U << 0)
1149
1150	/ If BPF_F_ANY_ALIGNMENT is used in BPF_PROG_LOAD command, the*
1151	* verifier will allow any alignment whatsoever. On platforms
1152	* with strict alignment requirements for loads ands stores (such
1153	* as sparc and mips) the verifier validates that all loads and
1154	* stores provably follow this requirement. This flag turns that
1155	* checking and enforcement off.
1156	*
1157	* It is mostly used for testing when we want to validate the
1158	* context and memory access aspects of the verifier, but because
1159	* of an unaligned access the alignment check would trigger before
1160	* the one we are interested in.
1161	*/
1162	#define BPF_F_ANY_ALIGNMENT (1U << 1)
1163
1164	/ BPF_F_TEST_RND_HI32 is used in BPF_PROG_LOAD command for testing purpose.*
1165	* Verifier does sub-register def/use analysis and identifies instructions whose
1166	* def only matters for low 32-bit, high 32-bit is never referenced later
1167	* through implicit zero extension. Therefore verifier notifies JIT back-ends
1168	* that it is safe to ignore clearing high 32-bit for these instructions. This
1169	* saves some back-ends a lot of code-gen. However such optimization is not
1170	* necessary on some arches, for example x86_64, arm64 etc, whose JIT back-ends
1171	* hence hasn't used verifier's analysis result. But, we really want to have a
1172	* way to be able to verify the correctness of the described optimization on
1173	* x86_64 on which testsuites are frequently exercised.
1174	*
1175	* So, this flag is introduced. Once it is set, verifier will randomize high
1176	* 32-bit for those instructions who has been identified as safe to ignore them.
1177	* Then, if verifier is not doing correct analysis, such randomization will
1178	* regress tests to expose bugs.
1179	*/
1180	#define BPF_F_TEST_RND_HI32 (1U << 2)
1181
1182	/ The verifier internal test flag. Behavior is undefined /
1183	#define BPF_F_TEST_STATE_FREQ (1U << 3)
1184
1185	/ If BPF_F_SLEEPABLE is used in BPF_PROG_LOAD command, the verifier will*
1186	* restrict map and helper usage for such programs. Sleepable BPF programs can
1187	* only be attached to hooks where kernel execution context allows sleeping.
1188	* Such programs are allowed to use helpers that may sleep like
1189	* bpf_copy_from_user().
1190	*/
1191	#define BPF_F_SLEEPABLE (1U << 4)
1192
1193	/ If BPF_F_XDP_HAS_FRAGS is used in BPF_PROG_LOAD command, the loaded program*
1194	* fully support xdp frags.
1195	*/
1196	#define BPF_F_XDP_HAS_FRAGS (1U << 5)
1197
1198	/ If BPF_F_XDP_DEV_BOUND_ONLY is used in BPF_PROG_LOAD command, the loaded*
1199	* program becomes device-bound but can access XDP metadata.
1200	*/
1201	#define BPF_F_XDP_DEV_BOUND_ONLY (1U << 6)
1202
1203	/ link_create.kprobe_multi.flags used in LINK_CREATE command for*
1204	* BPF_TRACE_KPROBE_MULTI attach type to create return probe.
1205	*/
1206	enum {
1207	BPF_F_KPROBE_MULTI_RETURN = (`1U` << `0`)
1208	};
1209
1210	/ link_create.uprobe_multi.flags used in LINK_CREATE command for*
1211	* BPF_TRACE_UPROBE_MULTI attach type to create return probe.
1212	*/
1213	enum {
1214	BPF_F_UPROBE_MULTI_RETURN = (`1U` << `0`)
1215	};
1216
1217	/ link_create.netfilter.flags used in LINK_CREATE command for*
1218	* BPF_PROG_TYPE_NETFILTER to enable IP packet defragmentation.
1219	*/
1220	#define BPF_F_NETFILTER_IP_DEFRAG (1U << 0)
1221
1222	/ When BPF ldimm64's insn[0].src_reg != 0 then this can have*
1223	* the following extensions:
1224	*
1225	* insn[0].src_reg: BPF_PSEUDO_MAP_[FD\|IDX]
1226	* insn[0].imm: map fd or fd_idx
1227	* insn[1].imm: 0
1228	* insn[0].off: 0
1229	* insn[1].off: 0
1230	* ldimm64 rewrite: address of map
1231	* verifier type: CONST_PTR_TO_MAP
1232	*/
1233	#define BPF_PSEUDO_MAP_FD 1
1234	#define BPF_PSEUDO_MAP_IDX 5
1235
1236	/ insn[0].src_reg: BPF_PSEUDO_MAP_[IDX_]VALUE*
1237	* insn[0].imm: map fd or fd_idx
1238	* insn[1].imm: offset into value
1239	* insn[0].off: 0
1240	* insn[1].off: 0
1241	* ldimm64 rewrite: address of map[0]+offset
1242	* verifier type: PTR_TO_MAP_VALUE
1243	*/
1244	#define BPF_PSEUDO_MAP_VALUE 2
1245	#define BPF_PSEUDO_MAP_IDX_VALUE 6
1246
1247	/ insn[0].src_reg: BPF_PSEUDO_BTF_ID*
1248	* insn[0].imm: kernel btd id of VAR
1249	* insn[1].imm: 0
1250	* insn[0].off: 0
1251	* insn[1].off: 0
1252	* ldimm64 rewrite: address of the kernel variable
1253	* verifier type: PTR_TO_BTF_ID or PTR_TO_MEM, depending on whether the var
1254	* is struct/union.
1255	*/
1256	#define BPF_PSEUDO_BTF_ID 3
1257	/ insn[0].src_reg: BPF_PSEUDO_FUNC*
1258	* insn[0].imm: insn offset to the func
1259	* insn[1].imm: 0
1260	* insn[0].off: 0
1261	* insn[1].off: 0
1262	* ldimm64 rewrite: address of the function
1263	* verifier type: PTR_TO_FUNC.
1264	*/
1265	#define BPF_PSEUDO_FUNC 4
1266
1267	/ when bpf_call->src_reg == BPF_PSEUDO_CALL, bpf_call->imm == pc-relative*
1268	* offset to another bpf function
1269	*/
1270	#define BPF_PSEUDO_CALL 1
1271	/ when bpf_call->src_reg == BPF_PSEUDO_KFUNC_CALL,*
1272	* bpf_call->imm == btf_id of a BTF_KIND_FUNC in the running kernel
1273	*/
1274	#define BPF_PSEUDO_KFUNC_CALL 2
1275
1276	/ flags for BPF_MAP_UPDATE_ELEM command /
1277	enum {
1278	BPF_ANY = `0`, / create new element or update existing /
1279	BPF_NOEXIST = `1`, / create new element if it didn't exist /
1280	BPF_EXIST = `2`, / update existing element /
1281	BPF_F_LOCK = `4`, / spin_lock-ed map_lookup/map_update /
1282	};
1283
1284	/ flags for BPF_MAP_CREATE command /
1285	enum {
1286	BPF_F_NO_PREALLOC = (`1U` << `0`),
1287	/ Instead of having one common LRU list in the*
1288	* BPF_MAP_TYPE_LRU_[PERCPU_]HASH map, use a percpu LRU list
1289	* which can scale and perform better.
1290	* Note, the LRU nodes (including free nodes) cannot be moved
1291	* across different LRU lists.
1292	*/
1293	BPF_F_NO_COMMON_LRU = (`1U` << `1`),
1294	/ Specify numa node during map creation /
1295	BPF_F_NUMA_NODE = (`1U` << `2`),
1296
1297	/ Flags for accessing BPF object from syscall side. /
1298	BPF_F_RDONLY = (`1U` << `3`),
1299	BPF_F_WRONLY = (`1U` << `4`),
1300
1301	/ Flag for stack_map, store build_id+offset instead of pointer /
1302	BPF_F_STACK_BUILD_ID = (`1U` << `5`),
1303
1304	/ Zero-initialize hash function seed. This should only be used for testing. /
1305	BPF_F_ZERO_SEED = (`1U` << `6`),
1306
1307	/ Flags for accessing BPF object from program side. /
1308	BPF_F_RDONLY_PROG = (`1U` << `7`),
1309	BPF_F_WRONLY_PROG = (`1U` << `8`),
1310
1311	/ Clone map from listener for newly accepted socket /
1312	BPF_F_CLONE = (`1U` << `9`),
1313
1314	/ Enable memory-mapping BPF map /
1315	BPF_F_MMAPABLE = (`1U` << `10`),
1316
1317	/ Share perf_event among processes /
1318	BPF_F_PRESERVE_ELEMS = (`1U` << `11`),
1319
1320	/ Create a map that is suitable to be an inner map with dynamic max entries /
1321	BPF_F_INNER_MAP = (`1U` << `12`),
1322
1323	/ Create a map that will be registered/unregesitered by the backed bpf_link /
1324	BPF_F_LINK = (`1U` << `13`),
1325
1326	/ Get path from provided FD in BPF_OBJ_PIN/BPF_OBJ_GET commands /
1327	BPF_F_PATH_FD = (`1U` << `14`),
1328	};
1329
1330	/ Flags for BPF_PROG_QUERY. /
1331
1332	/ Query effective (directly attached + inherited from ancestor cgroups)*
1333	* programs that will be executed for events within a cgroup.
1334	* attach_flags with this flag are always returned 0.
1335	*/
1336	#define BPF_F_QUERY_EFFECTIVE (1U << 0)
1337
1338	/ Flags for BPF_PROG_TEST_RUN /
1339
1340	/ If set, run the test on the cpu specified by bpf_attr.test.cpu /
1341	#define BPF_F_TEST_RUN_ON_CPU (1U << 0)
1342	/ If set, XDP frames will be transmitted after processing /
1343	#define BPF_F_TEST_XDP_LIVE_FRAMES (1U << 1)
1344
1345	/ type for BPF_ENABLE_STATS /
1346	enum bpf_stats_type {
1347	/ enabled run_time_ns and run_cnt /
1348	BPF_STATS_RUN_TIME = `0`,
1349	};
1350
1351	enum bpf_stack_build_id_status {
1352	/ user space need an empty entry to identify end of a trace /
1353	BPF_STACK_BUILD_ID_EMPTY = `0`,
1354	/ with valid build_id and offset /
1355	BPF_STACK_BUILD_ID_VALID = `1`,
1356	/ couldn't get build_id, fallback to ip /
1357	BPF_STACK_BUILD_ID_IP = `2`,
1358	};
1359
1360	#define BPF_BUILD_ID_SIZE 20
1361	struct bpf_stack_build_id {
1362	__s32 status;
1363	unsigned char build_id[BPF_BUILD_ID_SIZE];
1364	union {
1365	__u64 offset;
1366	__u64 ip;
1367	};
1368	};
1369
1370	#define BPF_OBJ_NAME_LEN 16U
1371
1372	union bpf_attr {
1373	struct { / anonymous struct used by BPF_MAP_CREATE command /
1374	__u32 map_type; / one of enum bpf_map_type /
1375	__u32 key_size; / size of key in bytes /
1376	__u32 value_size; / size of value in bytes /
1377	__u32 max_entries; / max number of entries in a map /
1378	__u32 map_flags; / BPF_MAP_CREATE related*
1379	* flags defined above.
1380	*/
1381	__u32 inner_map_fd; / fd pointing to the inner map /
1382	__u32 numa_node; / numa node (effective only if*
1383	* BPF_F_NUMA_NODE is set).
1384	*/
1385	char map_name[BPF_OBJ_NAME_LEN];
1386	__u32 map_ifindex; / ifindex of netdev to create on /
1387	__u32 btf_fd; / fd pointing to a BTF type data /
1388	__u32 btf_key_type_id; / BTF type_id of the key /
1389	__u32 btf_value_type_id; / BTF type_id of the value /
1390	__u32 btf_vmlinux_value_type_id;/ BTF type_id of a kernel-*
1391	* struct stored as the
1392	* map value
1393	*/
1394	/ Any per-map-type extra fields*
1395	*
1396	* BPF_MAP_TYPE_BLOOM_FILTER - the lowest 4 bits indicate the
1397	* number of hash functions (if 0, the bloom filter will default
1398	* to using 5 hash functions).
1399	*/
1400	__u64 map_extra;
1401	};
1402
1403	struct { / anonymous struct used by BPF_MAP__ELEM commands /*
1404	__u32 map_fd;
1405	__aligned_u64 key;
1406	union {
1407	__aligned_u64 value;
1408	__aligned_u64 next_key;
1409	};
1410	__u64 flags;
1411	};
1412
1413	struct { / struct used by BPF_MAP__BATCH commands /*
1414	__aligned_u64 in_batch; / start batch,*
1415	* NULL to start from beginning
1416	*/
1417	__aligned_u64 out_batch; / output: next start batch /
1418	__aligned_u64 keys;
1419	__aligned_u64 values;
1420	__u32 count; / input/output:*
1421	* input: # of key/value
1422	* elements
1423	* output: # of filled elements
1424	*/
1425	__u32 map_fd;
1426	__u64 elem_flags;
1427	__u64 flags;
1428	} batch;
1429
1430	struct { / anonymous struct used by BPF_PROG_LOAD command /
1431	__u32 prog_type; / one of enum bpf_prog_type /
1432	__u32 insn_cnt;
1433	__aligned_u64 insns;
1434	__aligned_u64 license;
1435	__u32 log_level; / verbosity level of verifier /
1436	__u32 log_size; / size of user buffer /
1437	__aligned_u64 log_buf; / user supplied buffer /
1438	__u32 kern_version; / not used /
1439	__u32 prog_flags;
1440	char prog_name[BPF_OBJ_NAME_LEN];
1441	__u32 prog_ifindex; / ifindex of netdev to prep for /
1442	/ For some prog types expected attach type must be known at*
1443	* load time to verify attach type specific parts of prog
1444	* (context accesses, allowed helpers, etc).
1445	*/
1446	__u32 expected_attach_type;
1447	__u32 prog_btf_fd; / fd pointing to BTF type data /
1448	__u32 func_info_rec_size; / userspace bpf_func_info size /
1449	__aligned_u64 func_info; / func info /
1450	__u32 func_info_cnt; / number of bpf_func_info records /
1451	__u32 line_info_rec_size; / userspace bpf_line_info size /
1452	__aligned_u64 line_info; / line info /
1453	__u32 line_info_cnt; / number of bpf_line_info records /
1454	__u32 attach_btf_id; / in-kernel BTF type id to attach to /
1455	union {
1456	/ valid prog_fd to attach to bpf prog /
1457	__u32 attach_prog_fd;
1458	/ or valid module BTF object fd or 0 to attach to vmlinux /
1459	__u32 attach_btf_obj_fd;
1460	};
1461	__u32 core_relo_cnt; / number of bpf_core_relo /
1462	__aligned_u64 fd_array; / array of FDs /
1463	__aligned_u64 core_relos;
1464	__u32 core_relo_rec_size; / sizeof(struct bpf_core_relo) /
1465	/ output: actual total log contents size (including termintaing zero).*
1466	* It could be both larger than original log_size (if log was
1467	* truncated), or smaller (if log buffer wasn't filled completely).
1468	*/
1469	__u32 log_true_size;
1470	};
1471
1472	struct { / anonymous struct used by BPF_OBJ_* commands /
1473	__aligned_u64 pathname;
1474	__u32 bpf_fd;
1475	__u32 file_flags;
1476	/ Same as dirfd in openat() syscall; see openat(2)*
1477	* manpage for details of path FD and pathname semantics;
1478	* path_fd should accompanied by BPF_F_PATH_FD flag set in
1479	* file_flags field, otherwise it should be set to zero;
1480	* if BPF_F_PATH_FD flag is not set, AT_FDCWD is assumed.
1481	*/
1482	__s32 path_fd;
1483	};
1484
1485	struct { / anonymous struct used by BPF_PROG_ATTACH/DETACH commands /
1486	union {
1487	__u32 target_fd; / target object to attach to or ... /
1488	__u32 target_ifindex; / target ifindex /
1489	};
1490	__u32 attach_bpf_fd;
1491	__u32 attach_type;
1492	__u32 attach_flags;
1493	__u32 replace_bpf_fd;
1494	union {
1495	__u32 relative_fd;
1496	__u32 relative_id;
1497	};
1498	__u64 expected_revision;
1499	};
1500
1501	struct { / anonymous struct used by BPF_PROG_TEST_RUN command /
1502	__u32 prog_fd;
1503	__u32 retval;
1504	__u32 data_size_in; / input: len of data_in /
1505	__u32 data_size_out; / input/output: len of data_out*
1506	* returns ENOSPC if data_out
1507	* is too small.
1508	*/
1509	__aligned_u64 data_in;
1510	__aligned_u64 data_out;
1511	__u32 repeat;
1512	__u32 duration;
1513	__u32 ctx_size_in; / input: len of ctx_in /
1514	__u32 ctx_size_out; / input/output: len of ctx_out*
1515	* returns ENOSPC if ctx_out
1516	* is too small.
1517	*/
1518	__aligned_u64 ctx_in;
1519	__aligned_u64 ctx_out;
1520	__u32 flags;
1521	__u32 cpu;
1522	__u32 batch_size;
1523	} test;
1524
1525	struct { / anonymous struct used by BPF__GET__ID /
1526	union {
1527	__u32 start_id;
1528	__u32 prog_id;
1529	__u32 map_id;
1530	__u32 btf_id;
1531	__u32 link_id;
1532	};
1533	__u32 next_id;
1534	__u32 open_flags;
1535	};
1536
1537	struct { / anonymous struct used by BPF_OBJ_GET_INFO_BY_FD /
1538	__u32 bpf_fd;
1539	__u32 info_len;
1540	__aligned_u64 info;
1541	} info;
1542
1543	struct { / anonymous struct used by BPF_PROG_QUERY command /
1544	union {
1545	__u32 target_fd; / target object to query or ... /
1546	__u32 target_ifindex; / target ifindex /
1547	};
1548	__u32 attach_type;
1549	__u32 query_flags;
1550	__u32 attach_flags;
1551	__aligned_u64 prog_ids;
1552	union {
1553	__u32 prog_cnt;
1554	__u32 count;
1555	};
1556	__u32 :`32`;
1557	/ output: per-program attach_flags.*
1558	* not allowed to be set during effective query.
1559	*/
1560	__aligned_u64 prog_attach_flags;
1561	__aligned_u64 link_ids;
1562	__aligned_u64 link_attach_flags;
1563	__u64 revision;
1564	} query;
1565
1566	struct { / anonymous struct used by BPF_RAW_TRACEPOINT_OPEN command /
1567	__u64 name;
1568	__u32 prog_fd;
1569	} raw_tracepoint;
1570
1571	struct { / anonymous struct for BPF_BTF_LOAD /
1572	__aligned_u64 btf;
1573	__aligned_u64 btf_log_buf;
1574	__u32 btf_size;
1575	__u32 btf_log_size;
1576	__u32 btf_log_level;
1577	/ output: actual total log contents size (including termintaing zero).*
1578	* It could be both larger than original log_size (if log was
1579	* truncated), or smaller (if log buffer wasn't filled completely).
1580	*/
1581	__u32 btf_log_true_size;
1582	};
1583
1584	struct {
1585	__u32 pid; / input: pid /
1586	__u32 fd; / input: fd /
1587	__u32 flags; / input: flags /
1588	__u32 buf_len; / input/output: buf len /
1589	__aligned_u64 buf; / input/output:*
1590	* tp_name for tracepoint
1591	* symbol for kprobe
1592	* filename for uprobe
1593	*/
1594	__u32 prog_id; / output: prod_id /
1595	__u32 fd_type; / output: BPF_FD_TYPE_* /
1596	__u64 probe_offset; / output: probe_offset /
1597	__u64 probe_addr; / output: probe_addr /
1598	} task_fd_query;
1599
1600	struct { / struct used by BPF_LINK_CREATE command /
1601	union {
1602	__u32 prog_fd; / eBPF program to attach /
1603	__u32 map_fd; / struct_ops to attach /
1604	};
1605	union {
1606	__u32 target_fd; / target object to attach to or ... /
1607	__u32 target_ifindex; / target ifindex /
1608	};
1609	__u32 attach_type; / attach type /
1610	__u32 flags; / extra flags /
1611	union {
1612	__u32 target_btf_id; / btf_id of target to attach to /
1613	struct {
1614	__aligned_u64 iter_info; / extra bpf_iter_link_info /
1615	__u32 iter_info_len; / iter_info length /
1616	};
1617	struct {
1618	/ black box user-provided value passed through*
1619	* to BPF program at the execution time and
1620	* accessible through bpf_get_attach_cookie() BPF helper
1621	*/
1622	__u64 bpf_cookie;
1623	} perf_event;
1624	struct {
1625	__u32 flags;
1626	__u32 cnt;
1627	__aligned_u64 syms;
1628	__aligned_u64 addrs;
1629	__aligned_u64 cookies;
1630	} kprobe_multi;
1631	struct {
1632	/ this is overlaid with the target_btf_id above. /
1633	__u32 target_btf_id;
1634	/ black box user-provided value passed through*
1635	* to BPF program at the execution time and
1636	* accessible through bpf_get_attach_cookie() BPF helper
1637	*/
1638	__u64 cookie;
1639	} tracing;
1640	struct {
1641	__u32 pf;
1642	__u32 hooknum;
1643	__s32 priority;
1644	__u32 flags;
1645	} netfilter;
1646	struct {
1647	union {
1648	__u32 relative_fd;
1649	__u32 relative_id;
1650	};
1651	__u64 expected_revision;
1652	} tcx;
1653	struct {
1654	__aligned_u64 path;
1655	__aligned_u64 offsets;
1656	__aligned_u64 ref_ctr_offsets;
1657	__aligned_u64 cookies;
1658	__u32 cnt;
1659	__u32 flags;
1660	__u32 pid;
1661	} uprobe_multi;
1662	struct {
1663	union {
1664	__u32 relative_fd;
1665	__u32 relative_id;
1666	};
1667	__u64 expected_revision;
1668	} netkit;
1669	};
1670	} link_create;
1671
1672	struct { / struct used by BPF_LINK_UPDATE command /
1673	__u32 link_fd; / link fd /
1674	union {
1675	/ new program fd to update link with /
1676	__u32 new_prog_fd;
1677	/ new struct_ops map fd to update link with /
1678	__u32 new_map_fd;
1679	};
1680	__u32 flags; / extra flags /
1681	union {
1682	/ expected link's program fd; is specified only if*
1683	* BPF_F_REPLACE flag is set in flags.
1684	*/
1685	__u32 old_prog_fd;
1686	/ expected link's map fd; is specified only*
1687	* if BPF_F_REPLACE flag is set.
1688	*/
1689	__u32 old_map_fd;
1690	};
1691	} link_update;
1692
1693	struct {
1694	__u32 link_fd;
1695	} link_detach;
1696
1697	struct { / struct used by BPF_ENABLE_STATS command /
1698	__u32 type;
1699	} enable_stats;
1700
1701	struct { / struct used by BPF_ITER_CREATE command /
1702	__u32 link_fd;
1703	__u32 flags;
1704	} iter_create;
1705
1706	struct { / struct used by BPF_PROG_BIND_MAP command /
1707	__u32 prog_fd;
1708	__u32 map_fd;
1709	__u32 flags; / extra flags /
1710	} prog_bind_map;
1711
1712	} __attribute__((aligned(`8`)));
1713
1714	/ The description below is an attempt at providing documentation to eBPF*
1715	* developers about the multiple available eBPF helper functions. It can be
1716	* parsed and used to produce a manual page. The workflow is the following,
1717	* and requires the rst2man utility:
1718	*
1719	* $ ./scripts/bpf_doc.py \
1720	* --filename include/uapi/linux/bpf.h > /tmp/bpf-helpers.rst
1721	* $ rst2man /tmp/bpf-helpers.rst > /tmp/bpf-helpers.7
1722	* $ man /tmp/bpf-helpers.7
1723	*
1724	* Note that in order to produce this external documentation, some RST
1725	* formatting is used in the descriptions to get "bold" and "italics" in
1726	* manual pages. Also note that the few trailing white spaces are
1727	* intentional, removing them would break paragraphs for rst2man.
1728	*
1729	* Start of BPF helper function descriptions:
1730	*
1731	* void bpf_map_lookup_elem(struct bpf_map map, const void *key)
1732	* Description
1733	* Perform a lookup in map for an entry associated to key.
1734	* Return
1735	* Map value associated to key, or NULL if no entry was
1736	* found.
1737	*
1738	* long bpf_map_update_elem(struct bpf_map map, const void key, const void *value, u64 flags)
1739	* Description
1740	* Add or update the value of the entry associated to key in
1741	* map with value. flags is one of:
1742	*
1743	* BPF_NOEXIST
1744	* The entry for key must not exist in the map.
1745	* BPF_EXIST
1746	* The entry for key must already exist in the map.
1747	* BPF_ANY
1748	* No condition on the existence of the entry for key.
1749	*
1750	* Flag value BPF_NOEXIST cannot be used for maps of types
1751	* BPF_MAP_TYPE_ARRAY or BPF_MAP_TYPE_PERCPU_ARRAY (all
1752	* elements always exist), the helper would return an error.
1753	* Return
1754	* 0 on success, or a negative error in case of failure.
1755	*
1756	* long bpf_map_delete_elem(struct bpf_map map, const void key)
1757	* Description
1758	* Delete entry with key from map.
1759	* Return
1760	* 0 on success, or a negative error in case of failure.
1761	*
1762	* long bpf_probe_read(void dst, u32 size, const void unsafe_ptr)
1763	* Description
1764	* For tracing programs, safely attempt to read size bytes from
1765	* kernel space address unsafe_ptr and store the data in dst.
1766	*
1767	* Generally, use bpf_probe_read_user\ () or
1768	* bpf_probe_read_kernel\ () instead.
1769	* Return
1770	* 0 on success, or a negative error in case of failure.
1771	*
1772	* u64 bpf_ktime_get_ns(void)
1773	* Description
1774	* Return the time elapsed since system boot, in nanoseconds.
1775	* Does not include time the system was suspended.
1776	* See: clock_gettime\ (CLOCK_MONOTONIC)
1777	* Return
1778	* Current ktime.
1779	*
1780	* long bpf_trace_printk(const char *fmt, u32 fmt_size, ...)
1781	* Description
1782	* This helper is a "printk()-like" facility for debugging. It
1783	* prints a message defined by format fmt (of size fmt_size)
1784	* to file \/sys/kernel/tracing/trace from TraceFS, if
1785	* available. It can take up to three additional u64
1786	* arguments (as an eBPF helpers, the total number of arguments is
1787	* limited to five).
1788	*
1789	* Each time the helper is called, it appends a line to the trace.
1790	* Lines are discarded while \/sys/kernel/tracing/trace is
1791	* open, use \/sys/kernel/tracing/trace_pipe to avoid this.
1792	* The format of the trace is customizable, and the exact output
1793	* one will get depends on the options set in
1794	* \/sys/kernel/tracing/trace_options (see also the
1795	* README file under the same directory). However, it usually
1796	* defaults to something like:
1797	*
1798	* ::
1799	*
1800	* telnet-470 [001] .N.. 419421.045894: 0x00000001: <formatted msg>
1801	*
1802	* In the above:
1803	*
1804	* * ``telnet`` is the name of the current task.
1805	* * ``470`` is the PID of the current task.
1806	* * ``001`` is the CPU number on which the task is
1807	* running.
1808	* * In ``.N..``, each character refers to a set of
1809	* options (whether irqs are enabled, scheduling
1810	* options, whether hard/softirqs are running, level of
1811	* preempt_disabled respectively). N means that
1812	* TIF_NEED_RESCHED and PREEMPT_NEED_RESCHED
1813	* are set.
1814	* * ``419421.045894`` is a timestamp.
1815	* * ``0x00000001`` is a fake value used by BPF for the
1816	* instruction pointer register.
1817	* * ``<formatted msg>`` is the message formatted with
1818	* fmt.
1819	*
1820	* The conversion specifiers supported by fmt are similar, but
1821	* more limited than for printk(). They are %d, %i,
1822	* %u, %x, %ld, %li, %lu, %lx, %lld,
1823	* %lli, %llu, %llx, %p, %s. No modifier (size
1824	* of field, padding with zeroes, etc.) is available, and the
1825	* helper will return -EINVAL (but print nothing) if it
1826	* encounters an unknown specifier.
1827	*
1828	* Also, note that bpf_trace_printk\ () is slow, and should
1829	* only be used for debugging purposes. For this reason, a notice
1830	* block (spanning several lines) is printed to kernel logs and
1831	* states that the helper should not be used "for production use"
1832	* the first time this helper is used (or more precisely, when
1833	* trace_printk\ () buffers are allocated). For passing values
1834	* to user space, perf events should be preferred.
1835	* Return
1836	* The number of bytes written to the buffer, or a negative error
1837	* in case of failure.
1838	*
1839	* u32 bpf_get_prandom_u32(void)
1840	* Description
1841	* Get a pseudo-random number.
1842	*
1843	* From a security point of view, this helper uses its own
1844	* pseudo-random internal state, and cannot be used to infer the
1845	* seed of other random functions in the kernel. However, it is
1846	* essential to note that the generator used by the helper is not
1847	* cryptographically secure.
1848	* Return
1849	* A random 32-bit unsigned value.
1850	*
1851	* u32 bpf_get_smp_processor_id(void)
1852	* Description
1853	* Get the SMP (symmetric multiprocessing) processor id. Note that
1854	* all programs run with migration disabled, which means that the
1855	* SMP processor id is stable during all the execution of the
1856	* program.
1857	* Return
1858	* The SMP id of the processor running the program.
1859	*
1860	* long bpf_skb_store_bytes(struct sk_buff skb, u32 offset, const void from, u32 len, u64 flags)
1861	* Description
1862	* Store len bytes from address from into the packet
1863	* associated to skb, at offset. flags are a combination of
1864	* BPF_F_RECOMPUTE_CSUM (automatically recompute the
1865	* checksum for the packet after storing the bytes) and
1866	* BPF_F_INVALIDATE_HASH (set skb\ ->hash, skb\
1867	* ->swhash and skb\ ->l4hash to 0).
1868	*
1869	* A call to this helper is susceptible to change the underlying
1870	* packet buffer. Therefore, at load time, all checks on pointers
1871	* previously done by the verifier are invalidated and must be
1872	* performed again, if the helper is used in combination with
1873	* direct packet access.
1874	* Return
1875	* 0 on success, or a negative error in case of failure.
1876	*
1877	* long bpf_l3_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 size)
1878	* Description
1879	* Recompute the layer 3 (e.g. IP) checksum for the packet
1880	* associated to skb. Computation is incremental, so the helper
1881	* must know the former value of the header field that was
1882	* modified (from), the new value of this field (to), and the
1883	* number of bytes (2 or 4) for this field, stored in size.
1884	* Alternatively, it is possible to store the difference between
1885	* the previous and the new values of the header field in to, by
1886	* setting from and size to 0. For both methods, offset
1887	* indicates the location of the IP checksum within the packet.
1888	*
1889	* This helper works in combination with bpf_csum_diff\ (),
1890	* which does not update the checksum in-place, but offers more
1891	* flexibility and can handle sizes larger than 2 or 4 for the
1892	* checksum to update.
1893	*
1894	* A call to this helper is susceptible to change the underlying
1895	* packet buffer. Therefore, at load time, all checks on pointers
1896	* previously done by the verifier are invalidated and must be
1897	* performed again, if the helper is used in combination with
1898	* direct packet access.
1899	* Return
1900	* 0 on success, or a negative error in case of failure.
1901	*
1902	* long bpf_l4_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 flags)
1903	* Description
1904	* Recompute the layer 4 (e.g. TCP, UDP or ICMP) checksum for the
1905	* packet associated to skb. Computation is incremental, so the
1906	* helper must know the former value of the header field that was
1907	* modified (from), the new value of this field (to), and the
1908	* number of bytes (2 or 4) for this field, stored on the lowest
1909	* four bits of flags. Alternatively, it is possible to store
1910	* the difference between the previous and the new values of the
1911	* header field in to, by setting from and the four lowest
1912	* bits of flags to 0. For both methods, offset indicates the
1913	* location of the IP checksum within the packet. In addition to
1914	* the size of the field, flags can be added (bitwise OR) actual
1915	* flags. With BPF_F_MARK_MANGLED_0, a null checksum is left
1916	* untouched (unless BPF_F_MARK_ENFORCE is added as well), and
1917	* for updates resulting in a null checksum the value is set to
1918	* CSUM_MANGLED_0 instead. Flag BPF_F_PSEUDO_HDR indicates
1919	* the checksum is to be computed against a pseudo-header.
1920	*
1921	* This helper works in combination with bpf_csum_diff\ (),
1922	* which does not update the checksum in-place, but offers more
1923	* flexibility and can handle sizes larger than 2 or 4 for the
1924	* checksum to update.
1925	*
1926	* A call to this helper is susceptible to change the underlying
1927	* packet buffer. Therefore, at load time, all checks on pointers
1928	* previously done by the verifier are invalidated and must be
1929	* performed again, if the helper is used in combination with
1930	* direct packet access.
1931	* Return
1932	* 0 on success, or a negative error in case of failure.
1933	*
1934	* long bpf_tail_call(void ctx, struct bpf_map prog_array_map, u32 index)
1935	* Description
1936	* This special helper is used to trigger a "tail call", or in
1937	* other words, to jump into another eBPF program. The same stack
1938	* frame is used (but values on stack and in registers for the
1939	* caller are not accessible to the callee). This mechanism allows
1940	* for program chaining, either for raising the maximum number of
1941	* available eBPF instructions, or to execute given programs in
1942	* conditional blocks. For security reasons, there is an upper
1943	* limit to the number of successive tail calls that can be
1944	* performed.
1945	*
1946	* Upon call of this helper, the program attempts to jump into a
1947	* program referenced at index index in prog_array_map, a
1948	* special map of type BPF_MAP_TYPE_PROG_ARRAY, and passes
1949	* ctx, a pointer to the context.
1950	*
1951	* If the call succeeds, the kernel immediately runs the first
1952	* instruction of the new program. This is not a function call,
1953	* and it never returns to the previous program. If the call
1954	* fails, then the helper has no effect, and the caller continues
1955	* to run its subsequent instructions. A call can fail if the
1956	* destination program for the jump does not exist (i.e. index
1957	* is superior to the number of entries in prog_array_map), or
1958	* if the maximum number of tail calls has been reached for this
1959	* chain of programs. This limit is defined in the kernel by the
1960	* macro MAX_TAIL_CALL_CNT (not accessible to user space),
1961	* which is currently set to 33.
1962	* Return
1963	* 0 on success, or a negative error in case of failure.
1964	*
1965	* long bpf_clone_redirect(struct sk_buff *skb, u32 ifindex, u64 flags)
1966	* Description
1967	* Clone and redirect the packet associated to skb to another
1968	* net device of index ifindex. Both ingress and egress
1969	* interfaces can be used for redirection. The BPF_F_INGRESS
1970	* value in flags is used to make the distinction (ingress path
1971	* is selected if the flag is present, egress path otherwise).
1972	* This is the only flag supported for now.
1973	*
1974	* In comparison with bpf_redirect\ () helper,
1975	* bpf_clone_redirect\ () has the associated cost of
1976	* duplicating the packet buffer, but this can be executed out of
1977	* the eBPF program. Conversely, bpf_redirect\ () is more
1978	* efficient, but it is handled through an action code where the
1979	* redirection happens only after the eBPF program has returned.
1980	*
1981	* A call to this helper is susceptible to change the underlying
1982	* packet buffer. Therefore, at load time, all checks on pointers
1983	* previously done by the verifier are invalidated and must be
1984	* performed again, if the helper is used in combination with
1985	* direct packet access.
1986	* Return
1987	* 0 on success, or a negative error in case of failure. Positive
1988	* error indicates a potential drop or congestion in the target
1989	* device. The particular positive error codes are not defined.
1990	*
1991	* u64 bpf_get_current_pid_tgid(void)
1992	* Description
1993	* Get the current pid and tgid.
1994	* Return
1995	* A 64-bit integer containing the current tgid and pid, and
1996	* created as such:
1997	* current_task\ ->tgid << 32 \\|
1998	* current_task\ ->pid.
1999	*
2000	* u64 bpf_get_current_uid_gid(void)
2001	* Description
2002	* Get the current uid and gid.
2003	* Return
2004	* A 64-bit integer containing the current GID and UID, and
2005	* created as such: current_gid << 32 \\| current_uid.
2006	*
2007	* long bpf_get_current_comm(void *buf, u32 size_of_buf)
2008	* Description
2009	* Copy the comm attribute of the current task into buf of
2010	* size_of_buf. The comm attribute contains the name of
2011	* the executable (excluding the path) for the current task. The
2012	* size_of_buf must be strictly positive. On success, the
2013	* helper makes sure that the buf is NUL-terminated. On failure,
2014	* it is filled with zeroes.
2015	* Return
2016	* 0 on success, or a negative error in case of failure.
2017	*
2018	* u32 bpf_get_cgroup_classid(struct sk_buff *skb)
2019	* Description
2020	* Retrieve the classid for the current task, i.e. for the net_cls
2021	* cgroup to which skb belongs.
2022	*
2023	* This helper can be used on TC egress path, but not on ingress.
2024	*
2025	* The net_cls cgroup provides an interface to tag network packets
2026	* based on a user-provided identifier for all traffic coming from
2027	* the tasks belonging to the related cgroup. See also the related
2028	* kernel documentation, available from the Linux sources in file
2029	* Documentation/admin-guide/cgroup-v1/net_cls.rst.
2030	*
2031	* The Linux kernel has two versions for cgroups: there are
2032	* cgroups v1 and cgroups v2. Both are available to users, who can
2033	* use a mixture of them, but note that the net_cls cgroup is for
2034	* cgroup v1 only. This makes it incompatible with BPF programs
2035	* run on cgroups, which is a cgroup-v2-only feature (a socket can
2036	* only hold data for one version of cgroups at a time).
2037	*
2038	* This helper is only available is the kernel was compiled with
2039	* the CONFIG_CGROUP_NET_CLASSID configuration option set to
2040	* "y" or to "m".
2041	* Return
2042	* The classid, or 0 for the default unconfigured classid.
2043	*
2044	* long bpf_skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci)
2045	* Description
2046	* Push a vlan_tci (VLAN tag control information) of protocol
2047	* vlan_proto to the packet associated to skb, then update
2048	* the checksum. Note that if vlan_proto is different from
2049	* ETH_P_8021Q and ETH_P_8021AD, it is considered to
2050	* be ETH_P_8021Q.
2051	*
2052	* A call to this helper is susceptible to change the underlying
2053	* packet buffer. Therefore, at load time, all checks on pointers
2054	* previously done by the verifier are invalidated and must be
2055	* performed again, if the helper is used in combination with
2056	* direct packet access.
2057	* Return
2058	* 0 on success, or a negative error in case of failure.
2059	*
2060	* long bpf_skb_vlan_pop(struct sk_buff *skb)
2061	* Description
2062	* Pop a VLAN header from the packet associated to skb.
2063	*
2064	* A call to this helper is susceptible to change the underlying
2065	* packet buffer. Therefore, at load time, all checks on pointers
2066	* previously done by the verifier are invalidated and must be
2067	* performed again, if the helper is used in combination with
2068	* direct packet access.
2069	* Return
2070	* 0 on success, or a negative error in case of failure.
2071	*
2072	* long bpf_skb_get_tunnel_key(struct sk_buff skb, struct bpf_tunnel_key key, u32 size, u64 flags)
2073	* Description
2074	* Get tunnel metadata. This helper takes a pointer key to an
2075	* empty struct bpf_tunnel_key of size, that will be
2076	* filled with tunnel metadata for the packet associated to skb.
2077	* The flags can be set to BPF_F_TUNINFO_IPV6, which
2078	* indicates that the tunnel is based on IPv6 protocol instead of
2079	* IPv4.
2080	*
2081	* The struct bpf_tunnel_key is an object that generalizes the
2082	* principal parameters used by various tunneling protocols into a
2083	* single struct. This way, it can be used to easily make a
2084	* decision based on the contents of the encapsulation header,
2085	* "summarized" in this struct. In particular, it holds the IP
2086	* address of the remote end (IPv4 or IPv6, depending on the case)
2087	* in key\ ->remote_ipv4 or key\ ->remote_ipv6. Also,
2088	* this struct exposes the key\ ->tunnel_id, which is
2089	* generally mapped to a VNI (Virtual Network Identifier), making
2090	* it programmable together with the bpf_skb_set_tunnel_key\
2091	* () helper.
2092	*
2093	* Let's imagine that the following code is part of a program
2094	* attached to the TC ingress interface, on one end of a GRE
2095	* tunnel, and is supposed to filter out all messages coming from
2096	* remote ends with IPv4 address other than 10.0.0.1:
2097	*
2098	* ::
2099	*
2100	* int ret;
2101	* struct bpf_tunnel_key key = {};
2102	*
2103	* ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
2104	* if (ret < 0)
2105	* return TC_ACT_SHOT; // drop packet
2106	*
2107	* if (key.remote_ipv4 != 0x0a000001)
2108	* return TC_ACT_SHOT; // drop packet
2109	*
2110	* return TC_ACT_OK; // accept packet
2111	*
2112	* This interface can also be used with all encapsulation devices
2113	* that can operate in "collect metadata" mode: instead of having
2114	* one network device per specific configuration, the "collect
2115	* metadata" mode only requires a single device where the
2116	* configuration can be extracted from this helper.
2117	*
2118	* This can be used together with various tunnels such as VXLan,
2119	* Geneve, GRE or IP in IP (IPIP).
2120	* Return
2121	* 0 on success, or a negative error in case of failure.
2122	*
2123	* long bpf_skb_set_tunnel_key(struct sk_buff skb, struct bpf_tunnel_key key, u32 size, u64 flags)
2124	* Description
2125	* Populate tunnel metadata for packet associated to skb. The
2126	* tunnel metadata is set to the contents of key, of size. The
2127	* flags can be set to a combination of the following values:
2128	*
2129	* BPF_F_TUNINFO_IPV6
2130	* Indicate that the tunnel is based on IPv6 protocol
2131	* instead of IPv4.
2132	* BPF_F_ZERO_CSUM_TX
2133	* For IPv4 packets, add a flag to tunnel metadata
2134	* indicating that checksum computation should be skipped
2135	* and checksum set to zeroes.
2136	* BPF_F_DONT_FRAGMENT
2137	* Add a flag to tunnel metadata indicating that the
2138	* packet should not be fragmented.
2139	* BPF_F_SEQ_NUMBER
2140	* Add a flag to tunnel metadata indicating that a
2141	* sequence number should be added to tunnel header before
2142	* sending the packet. This flag was added for GRE
2143	* encapsulation, but might be used with other protocols
2144	* as well in the future.
2145	* BPF_F_NO_TUNNEL_KEY
2146	* Add a flag to tunnel metadata indicating that no tunnel
2147	* key should be set in the resulting tunnel header.
2148	*
2149	* Here is a typical usage on the transmit path:
2150	*
2151	* ::
2152	*
2153	* struct bpf_tunnel_key key;
2154	* populate key ...
2155	* bpf_skb_set_tunnel_key(skb, &key, sizeof(key), 0);
2156	* bpf_clone_redirect(skb, vxlan_dev_ifindex, 0);
2157	*
2158	* See also the description of the bpf_skb_get_tunnel_key\ ()
2159	* helper for additional information.
2160	* Return
2161	* 0 on success, or a negative error in case of failure.
2162	*
2163	* u64 bpf_perf_event_read(struct bpf_map *map, u64 flags)
2164	* Description
2165	* Read the value of a perf event counter. This helper relies on a
2166	* map of type BPF_MAP_TYPE_PERF_EVENT_ARRAY. The nature of
2167	* the perf event counter is selected when map is updated with
2168	* perf event file descriptors. The map is an array whose size
2169	* is the number of available CPUs, and each cell contains a value
2170	* relative to one CPU. The value to retrieve is indicated by
2171	* flags, that contains the index of the CPU to look up, masked
2172	* with BPF_F_INDEX_MASK. Alternatively, flags can be set to
2173	* BPF_F_CURRENT_CPU to indicate that the value for the
2174	* current CPU should be retrieved.
2175	*
2176	* Note that before Linux 4.13, only hardware perf event can be
2177	* retrieved.
2178	*
2179	* Also, be aware that the newer helper
2180	* bpf_perf_event_read_value\ () is recommended over
2181	* bpf_perf_event_read\ () in general. The latter has some ABI
2182	* quirks where error and counter value are used as a return code
2183	* (which is wrong to do since ranges may overlap). This issue is
2184	* fixed with bpf_perf_event_read_value\ (), which at the same
2185	* time provides more features over the bpf_perf_event_read\
2186	* () interface. Please refer to the description of
2187	* bpf_perf_event_read_value\ () for details.
2188	* Return
2189	* The value of the perf event counter read from the map, or a
2190	* negative error code in case of failure.
2191	*
2192	* long bpf_redirect(u32 ifindex, u64 flags)
2193	* Description
2194	* Redirect the packet to another net device of index ifindex.
2195	* This helper is somewhat similar to bpf_clone_redirect\
2196	* (), except that the packet is not cloned, which provides
2197	* increased performance.
2198	*
2199	* Except for XDP, both ingress and egress interfaces can be used
2200	* for redirection. The BPF_F_INGRESS value in flags is used
2201	* to make the distinction (ingress path is selected if the flag
2202	* is present, egress path otherwise). Currently, XDP only
2203	* supports redirection to the egress interface, and accepts no
2204	* flag at all.
2205	*
2206	* The same effect can also be attained with the more generic
2207	* bpf_redirect_map\ (), which uses a BPF map to store the
2208	* redirect target instead of providing it directly to the helper.
2209	* Return
2210	* For XDP, the helper returns XDP_REDIRECT on success or
2211	* XDP_ABORTED on error. For other program types, the values
2212	* are TC_ACT_REDIRECT on success or TC_ACT_SHOT on
2213	* error.
2214	*
2215	* u32 bpf_get_route_realm(struct sk_buff *skb)
2216	* Description
2217	* Retrieve the realm or the route, that is to say the
2218	* tclassid field of the destination for the skb. The
2219	* identifier retrieved is a user-provided tag, similar to the
2220	* one used with the net_cls cgroup (see description for
2221	* bpf_get_cgroup_classid\ () helper), but here this tag is
2222	* held by a route (a destination entry), not by a task.
2223	*
2224	* Retrieving this identifier works with the clsact TC egress hook
2225	* (see also tc-bpf(8)), or alternatively on conventional
2226	* classful egress qdiscs, but not on TC ingress path. In case of
2227	* clsact TC egress hook, this has the advantage that, internally,
2228	* the destination entry has not been dropped yet in the transmit
2229	* path. Therefore, the destination entry does not need to be
2230	* artificially held via netif_keep_dst\ () for a classful
2231	* qdisc until the skb is freed.
2232	*
2233	* This helper is available only if the kernel was compiled with
2234	* CONFIG_IP_ROUTE_CLASSID configuration option.
2235	* Return
2236	* The realm of the route for the packet associated to skb, or 0
2237	* if none was found.
2238	*
2239	* long bpf_perf_event_output(void ctx, struct bpf_map map, u64 flags, void *data, u64 size)
2240	* Description
2241	* Write raw data blob into a special BPF perf event held by
2242	* map of type BPF_MAP_TYPE_PERF_EVENT_ARRAY. This perf
2243	* event must have the following attributes: PERF_SAMPLE_RAW
2244	* as sample_type, PERF_TYPE_SOFTWARE as type, and
2245	* PERF_COUNT_SW_BPF_OUTPUT as config.
2246	*
2247	* The flags are used to indicate the index in map for which
2248	* the value must be put, masked with BPF_F_INDEX_MASK.
2249	* Alternatively, flags can be set to BPF_F_CURRENT_CPU
2250	* to indicate that the index of the current CPU core should be
2251	* used.
2252	*
2253	* The value to write, of size, is passed through eBPF stack and
2254	* pointed by data.
2255	*
2256	* The context of the program ctx needs also be passed to the
2257	* helper.
2258	*
2259	* On user space, a program willing to read the values needs to
2260	* call perf_event_open\ () on the perf event (either for
2261	* one or for all CPUs) and to store the file descriptor into the
2262	* map. This must be done before the eBPF program can send data
2263	* into it. An example is available in file
2264	* samples/bpf/trace_output_user.c in the Linux kernel source
2265	* tree (the eBPF program counterpart is in
2266	* samples/bpf/trace_output_kern.c).
2267	*
2268	* bpf_perf_event_output\ () achieves better performance
2269	* than bpf_trace_printk\ () for sharing data with user
2270	* space, and is much better suitable for streaming data from eBPF
2271	* programs.
2272	*
2273	* Note that this helper is not restricted to tracing use cases
2274	* and can be used with programs attached to TC or XDP as well,
2275	* where it allows for passing data to user space listeners. Data
2276	* can be:
2277	*
2278	* * Only custom structs,
2279	* * Only the packet payload, or
2280	* * A combination of both.
2281	* Return
2282	* 0 on success, or a negative error in case of failure.
2283	*
2284	* long bpf_skb_load_bytes(const void skb, u32 offset, void to, u32 len)
2285	* Description
2286	* This helper was provided as an easy way to load data from a
2287	* packet. It can be used to load len bytes from offset from
2288	* the packet associated to skb, into the buffer pointed by
2289	* to.
2290	*
2291	* Since Linux 4.7, usage of this helper has mostly been replaced
2292	* by "direct packet access", enabling packet data to be
2293	* manipulated with skb\ ->data and skb\ ->data_end
2294	* pointing respectively to the first byte of packet data and to
2295	* the byte after the last byte of packet data. However, it
2296	* remains useful if one wishes to read large quantities of data
2297	* at once from a packet into the eBPF stack.
2298	* Return
2299	* 0 on success, or a negative error in case of failure.
2300	*
2301	* long bpf_get_stackid(void ctx, struct bpf_map map, u64 flags)
2302	* Description
2303	* Walk a user or a kernel stack and return its id. To achieve
2304	* this, the helper needs ctx, which is a pointer to the context
2305	* on which the tracing program is executed, and a pointer to a
2306	* map of type BPF_MAP_TYPE_STACK_TRACE.
2307	*
2308	* The last argument, flags, holds the number of stack frames to
2309	* skip (from 0 to 255), masked with
2310	* BPF_F_SKIP_FIELD_MASK. The next bits can be used to set
2311	* a combination of the following flags:
2312	*
2313	* BPF_F_USER_STACK
2314	* Collect a user space stack instead of a kernel stack.
2315	* BPF_F_FAST_STACK_CMP
2316	* Compare stacks by hash only.
2317	* BPF_F_REUSE_STACKID
2318	* If two different stacks hash into the same stackid,
2319	* discard the old one.
2320	*
2321	* The stack id retrieved is a 32 bit long integer handle which
2322	* can be further combined with other data (including other stack
2323	* ids) and used as a key into maps. This can be useful for
2324	* generating a variety of graphs (such as flame graphs or off-cpu
2325	* graphs).
2326	*
2327	* For walking a stack, this helper is an improvement over
2328	* bpf_probe_read\ (), which can be used with unrolled loops
2329	* but is not efficient and consumes a lot of eBPF instructions.
2330	* Instead, bpf_get_stackid\ () can collect up to
2331	* PERF_MAX_STACK_DEPTH both kernel and user frames. Note that
2332	* this limit can be controlled with the sysctl program, and
2333	* that it should be manually increased in order to profile long
2334	* user stacks (such as stacks for Java programs). To do so, use:
2335	*
2336	* ::
2337	*
2338	* # sysctl kernel.perf_event_max_stack=<new value>
2339	* Return
2340	* The positive or null stack id on success, or a negative error
2341	* in case of failure.
2342	*
2343	* s64 bpf_csum_diff(__be32 from, u32 from_size, __be32 to, u32 to_size, __wsum seed)
2344	* Description
2345	* Compute a checksum difference, from the raw buffer pointed by
2346	* from, of length from_size (that must be a multiple of 4),
2347	* towards the raw buffer pointed by to, of size to_size
2348	* (same remark). An optional seed can be added to the value
2349	* (this can be cascaded, the seed may come from a previous call
2350	* to the helper).
2351	*
2352	* This is flexible enough to be used in several ways:
2353	*
2354	* * With from_size == 0, to_size > 0 and seed set to
2355	* checksum, it can be used when pushing new data.
2356	* * With from_size > 0, to_size == 0 and seed set to
2357	* checksum, it can be used when removing data from a packet.
2358	* * With from_size > 0, to_size > 0 and seed set to 0, it
2359	* can be used to compute a diff. Note that from_size and
2360	* to_size do not need to be equal.
2361	*
2362	* This helper can be used in combination with
2363	* bpf_l3_csum_replace\ () and bpf_l4_csum_replace\ (), to
2364	* which one can feed in the difference computed with
2365	* bpf_csum_diff\ ().
2366	* Return
2367	* The checksum result, or a negative error code in case of
2368	* failure.
2369	*
2370	* long bpf_skb_get_tunnel_opt(struct sk_buff skb, void opt, u32 size)
2371	* Description
2372	* Retrieve tunnel options metadata for the packet associated to
2373	* skb, and store the raw tunnel option data to the buffer opt
2374	* of size.
2375	*
2376	* This helper can be used with encapsulation devices that can
2377	* operate in "collect metadata" mode (please refer to the related
2378	* note in the description of bpf_skb_get_tunnel_key\ () for
2379	* more details). A particular example where this can be used is
2380	* in combination with the Geneve encapsulation protocol, where it
2381	* allows for pushing (with bpf_skb_get_tunnel_opt\ () helper)
2382	* and retrieving arbitrary TLVs (Type-Length-Value headers) from
2383	* the eBPF program. This allows for full customization of these
2384	* headers.
2385	* Return
2386	* The size of the option data retrieved.
2387	*
2388	* long bpf_skb_set_tunnel_opt(struct sk_buff skb, void opt, u32 size)
2389	* Description
2390	* Set tunnel options metadata for the packet associated to skb
2391	* to the option data contained in the raw buffer opt of size.
2392	*
2393	* See also the description of the bpf_skb_get_tunnel_opt\ ()
2394	* helper for additional information.
2395	* Return
2396	* 0 on success, or a negative error in case of failure.
2397	*
2398	* long bpf_skb_change_proto(struct sk_buff *skb, __be16 proto, u64 flags)
2399	* Description
2400	* Change the protocol of the skb to proto. Currently
2401	* supported are transition from IPv4 to IPv6, and from IPv6 to
2402	* IPv4. The helper takes care of the groundwork for the
2403	* transition, including resizing the socket buffer. The eBPF
2404	* program is expected to fill the new headers, if any, via
2405	* skb_store_bytes\ () and to recompute the checksums with
2406	* bpf_l3_csum_replace\ () and bpf_l4_csum_replace\
2407	* (). The main case for this helper is to perform NAT64
2408	* operations out of an eBPF program.
2409	*
2410	* Internally, the GSO type is marked as dodgy so that headers are
2411	* checked and segments are recalculated by the GSO/GRO engine.
2412	* The size for GSO target is adapted as well.
2413	*
2414	* All values for flags are reserved for future usage, and must
2415	* be left at zero.
2416	*
2417	* A call to this helper is susceptible to change the underlying
2418	* packet buffer. Therefore, at load time, all checks on pointers
2419	* previously done by the verifier are invalidated and must be
2420	* performed again, if the helper is used in combination with
2421	* direct packet access.
2422	* Return
2423	* 0 on success, or a negative error in case of failure.
2424	*
2425	* long bpf_skb_change_type(struct sk_buff *skb, u32 type)
2426	* Description
2427	* Change the packet type for the packet associated to skb. This
2428	* comes down to setting skb\ ->pkt_type to type, except
2429	* the eBPF program does not have a write access to skb\
2430	* ->pkt_type beside this helper. Using a helper here allows
2431	* for graceful handling of errors.
2432	*
2433	* The major use case is to change incoming skbs to
2434	* PACKET_HOST in a programmatic way instead of having to
2435	* recirculate via redirect\ (..., BPF_F_INGRESS), for
2436	* example.
2437	*
2438	* Note that type only allows certain values. At this time, they
2439	* are:
2440	*
2441	* PACKET_HOST
2442	* Packet is for us.
2443	* PACKET_BROADCAST
2444	* Send packet to all.
2445	* PACKET_MULTICAST
2446	* Send packet to group.
2447	* PACKET_OTHERHOST
2448	* Send packet to someone else.
2449	* Return
2450	* 0 on success, or a negative error in case of failure.
2451	*
2452	* long bpf_skb_under_cgroup(struct sk_buff skb, struct bpf_map map, u32 index)
2453	* Description
2454	* Check whether skb is a descendant of the cgroup2 held by
2455	* map of type BPF_MAP_TYPE_CGROUP_ARRAY, at index.
2456	* Return
2457	* The return value depends on the result of the test, and can be:
2458	*
2459	* * 0, if the skb failed the cgroup2 descendant test.
2460	* * 1, if the skb succeeded the cgroup2 descendant test.
2461	* * A negative error code, if an error occurred.
2462	*
2463	* u32 bpf_get_hash_recalc(struct sk_buff *skb)
2464	* Description
2465	* Retrieve the hash of the packet, skb\ ->hash. If it is
2466	* not set, in particular if the hash was cleared due to mangling,
2467	* recompute this hash. Later accesses to the hash can be done
2468	* directly with skb\ ->hash.
2469	*
2470	* Calling bpf_set_hash_invalid\ (), changing a packet
2471	* prototype with bpf_skb_change_proto\ (), or calling
2472	* bpf_skb_store_bytes\ () with the
2473	* BPF_F_INVALIDATE_HASH are actions susceptible to clear
2474	* the hash and to trigger a new computation for the next call to
2475	* bpf_get_hash_recalc\ ().
2476	* Return
2477	* The 32-bit hash.
2478	*
2479	* u64 bpf_get_current_task(void)
2480	* Description
2481	* Get the current task.
2482	* Return
2483	* A pointer to the current task struct.
2484	*
2485	* long bpf_probe_write_user(void dst, const void src, u32 len)
2486	* Description
2487	* Attempt in a safe way to write len bytes from the buffer
2488	* src to dst in memory. It only works for threads that are in
2489	* user context, and dst must be a valid user space address.
2490	*
2491	* This helper should not be used to implement any kind of
2492	* security mechanism because of TOC-TOU attacks, but rather to
2493	* debug, divert, and manipulate execution of semi-cooperative
2494	* processes.
2495	*
2496	* Keep in mind that this feature is meant for experiments, and it
2497	* has a risk of crashing the system and running programs.
2498	* Therefore, when an eBPF program using this helper is attached,
2499	* a warning including PID and process name is printed to kernel
2500	* logs.
2501	* Return
2502	* 0 on success, or a negative error in case of failure.
2503	*
2504	* long bpf_current_task_under_cgroup(struct bpf_map *map, u32 index)
2505	* Description
2506	* Check whether the probe is being run is the context of a given
2507	* subset of the cgroup2 hierarchy. The cgroup2 to test is held by
2508	* map of type BPF_MAP_TYPE_CGROUP_ARRAY, at index.
2509	* Return
2510	* The return value depends on the result of the test, and can be:
2511	*
2512	* * 1, if current task belongs to the cgroup2.
2513	* * 0, if current task does not belong to the cgroup2.
2514	* * A negative error code, if an error occurred.
2515	*
2516	* long bpf_skb_change_tail(struct sk_buff *skb, u32 len, u64 flags)
2517	* Description
2518	* Resize (trim or grow) the packet associated to skb to the
2519	* new len. The flags are reserved for future usage, and must
2520	* be left at zero.
2521	*
2522	* The basic idea is that the helper performs the needed work to
2523	* change the size of the packet, then the eBPF program rewrites
2524	* the rest via helpers like bpf_skb_store_bytes\ (),
2525	* bpf_l3_csum_replace\ (), bpf_l3_csum_replace\ ()
2526	* and others. This helper is a slow path utility intended for
2527	* replies with control messages. And because it is targeted for
2528	* slow path, the helper itself can afford to be slow: it
2529	* implicitly linearizes, unclones and drops offloads from the
2530	* skb.
2531	*
2532	* A call to this helper is susceptible to change the underlying
2533	* packet buffer. Therefore, at load time, all checks on pointers
2534	* previously done by the verifier are invalidated and must be
2535	* performed again, if the helper is used in combination with
2536	* direct packet access.
2537	* Return
2538	* 0 on success, or a negative error in case of failure.
2539	*
2540	* long bpf_skb_pull_data(struct sk_buff *skb, u32 len)
2541	* Description
2542	* Pull in non-linear data in case the skb is non-linear and not
2543	* all of len are part of the linear section. Make len bytes
2544	* from skb readable and writable. If a zero value is passed for
2545	* len, then all bytes in the linear part of skb will be made
2546	* readable and writable.
2547	*
2548	* This helper is only needed for reading and writing with direct
2549	* packet access.
2550	*
2551	* For direct packet access, testing that offsets to access
2552	* are within packet boundaries (test on skb\ ->data_end) is
2553	* susceptible to fail if offsets are invalid, or if the requested
2554	* data is in non-linear parts of the skb. On failure the
2555	* program can just bail out, or in the case of a non-linear
2556	* buffer, use a helper to make the data available. The
2557	* bpf_skb_load_bytes\ () helper is a first solution to access
2558	* the data. Another one consists in using bpf_skb_pull_data
2559	* to pull in once the non-linear parts, then retesting and
2560	* eventually access the data.
2561	*
2562	* At the same time, this also makes sure the skb is uncloned,
2563	* which is a necessary condition for direct write. As this needs
2564	* to be an invariant for the write part only, the verifier
2565	* detects writes and adds a prologue that is calling
2566	* bpf_skb_pull_data() to effectively unclone the skb from
2567	* the very beginning in case it is indeed cloned.
2568	*
2569	* A call to this helper is susceptible to change the underlying
2570	* packet buffer. Therefore, at load time, all checks on pointers
2571	* previously done by the verifier are invalidated and must be
2572	* performed again, if the helper is used in combination with
2573	* direct packet access.
2574	* Return
2575	* 0 on success, or a negative error in case of failure.
2576	*
2577	* s64 bpf_csum_update(struct sk_buff *skb, __wsum csum)
2578	* Description
2579	* Add the checksum csum into skb\ ->csum in case the
2580	* driver has supplied a checksum for the entire packet into that
2581	* field. Return an error otherwise. This helper is intended to be
2582	* used in combination with bpf_csum_diff\ (), in particular
2583	* when the checksum needs to be updated after data has been
2584	* written into the packet through direct packet access.
2585	* Return
2586	* The checksum on success, or a negative error code in case of
2587	* failure.
2588	*
2589	* void bpf_set_hash_invalid(struct sk_buff *skb)
2590	* Description
2591	* Invalidate the current skb\ ->hash. It can be used after
2592	* mangling on headers through direct packet access, in order to
2593	* indicate that the hash is outdated and to trigger a
2594	* recalculation the next time the kernel tries to access this
2595	* hash or when the bpf_get_hash_recalc\ () helper is called.
2596	* Return
2597	* void.
2598	*
2599	* long bpf_get_numa_node_id(void)
2600	* Description
2601	* Return the id of the current NUMA node. The primary use case
2602	* for this helper is the selection of sockets for the local NUMA
2603	* node, when the program is attached to sockets using the
2604	* SO_ATTACH_REUSEPORT_EBPF option (see also socket(7)),
2605	* but the helper is also available to other eBPF program types,
2606	* similarly to bpf_get_smp_processor_id\ ().
2607	* Return
2608	* The id of current NUMA node.
2609	*
2610	* long bpf_skb_change_head(struct sk_buff *skb, u32 len, u64 flags)
2611	* Description
2612	* Grows headroom of packet associated to skb and adjusts the
2613	* offset of the MAC header accordingly, adding len bytes of
2614	* space. It automatically extends and reallocates memory as
2615	* required.
2616	*
2617	* This helper can be used on a layer 3 skb to push a MAC header
2618	* for redirection into a layer 2 device.
2619	*
2620	* All values for flags are reserved for future usage, and must
2621	* be left at zero.
2622	*
2623	* A call to this helper is susceptible to change the underlying
2624	* packet buffer. Therefore, at load time, all checks on pointers
2625	* previously done by the verifier are invalidated and must be
2626	* performed again, if the helper is used in combination with
2627	* direct packet access.
2628	* Return
2629	* 0 on success, or a negative error in case of failure.
2630	*
2631	* long bpf_xdp_adjust_head(struct xdp_buff *xdp_md, int delta)
2632	* Description
2633	* Adjust (move) xdp_md\ ->data by delta bytes. Note that
2634	* it is possible to use a negative value for delta. This helper
2635	* can be used to prepare the packet for pushing or popping
2636	* headers.
2637	*
2638	* A call to this helper is susceptible to change the underlying
2639	* packet buffer. Therefore, at load time, all checks on pointers
2640	* previously done by the verifier are invalidated and must be
2641	* performed again, if the helper is used in combination with
2642	* direct packet access.
2643	* Return
2644	* 0 on success, or a negative error in case of failure.
2645	*
2646	* long bpf_probe_read_str(void dst, u32 size, const void unsafe_ptr)
2647	* Description
2648	* Copy a NUL terminated string from an unsafe kernel address
2649	* unsafe_ptr to dst. See bpf_probe_read_kernel_str\ () for
2650	* more details.
2651	*
2652	* Generally, use bpf_probe_read_user_str\ () or
2653	* bpf_probe_read_kernel_str\ () instead.
2654	* Return
2655	* On success, the strictly positive length of the string,
2656	* including the trailing NUL character. On error, a negative
2657	* value.
2658	*
2659	* u64 bpf_get_socket_cookie(struct sk_buff *skb)
2660	* Description
2661	* If the struct sk_buff pointed by skb has a known socket,
2662	* retrieve the cookie (generated by the kernel) of this socket.
2663	* If no cookie has been set yet, generate a new cookie. Once
2664	* generated, the socket cookie remains stable for the life of the
2665	* socket. This helper can be useful for monitoring per socket
2666	* networking traffic statistics as it provides a global socket
2667	* identifier that can be assumed unique.
2668	* Return
2669	* A 8-byte long unique number on success, or 0 if the socket
2670	* field is missing inside skb.
2671	*
2672	* u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx)
2673	* Description
2674	* Equivalent to bpf_get_socket_cookie() helper that accepts
2675	* skb, but gets socket from struct bpf_sock_addr context.
2676	* Return
2677	* A 8-byte long unique number.
2678	*
2679	* u64 bpf_get_socket_cookie(struct bpf_sock_ops *ctx)
2680	* Description
2681	* Equivalent to bpf_get_socket_cookie\ () helper that accepts
2682	* skb, but gets socket from struct bpf_sock_ops context.
2683	* Return
2684	* A 8-byte long unique number.
2685	*
2686	* u64 bpf_get_socket_cookie(struct sock *sk)
2687	* Description
2688	* Equivalent to bpf_get_socket_cookie\ () helper that accepts
2689	* sk, but gets socket from a BTF struct sock. This helper
2690	* also works for sleepable programs.
2691	* Return
2692	* A 8-byte long unique number or 0 if sk is NULL.
2693	*
2694	* u32 bpf_get_socket_uid(struct sk_buff *skb)
2695	* Description
2696	* Get the owner UID of the socked associated to skb.
2697	* Return
2698	* The owner UID of the socket associated to skb. If the socket
2699	* is NULL, or if it is not a full socket (i.e. if it is a
2700	* time-wait or a request socket instead), overflowuid value
2701	* is returned (note that overflowuid might also be the actual
2702	* UID value for the socket).
2703	*
2704	* long bpf_set_hash(struct sk_buff *skb, u32 hash)
2705	* Description
2706	* Set the full hash for skb (set the field skb\ ->hash)
2707	* to value hash.
2708	* Return
2709	* 0
2710	*
2711	* long bpf_setsockopt(void bpf_socket, int level, int optname, void optval, int optlen)
2712	* Description
2713	* Emulate a call to setsockopt() on the socket associated to
2714	* bpf_socket, which must be a full socket. The level at
2715	* which the option resides and the name optname of the option
2716	* must be specified, see setsockopt(2) for more information.
2717	* The option value of length optlen is pointed by optval.
2718	*
2719	* bpf_socket should be one of the following:
2720	*
2721	* * struct bpf_sock_ops for BPF_PROG_TYPE_SOCK_OPS.
2722	* * struct bpf_sock_addr for BPF_CGROUP_INET4_CONNECT,
2723	* BPF_CGROUP_INET6_CONNECT and BPF_CGROUP_UNIX_CONNECT.
2724	*
2725	* This helper actually implements a subset of setsockopt().
2726	* It supports the following level\ s:
2727	*
2728	* * SOL_SOCKET, which supports the following optname\ s:
2729	* SO_RCVBUF, SO_SNDBUF, SO_MAX_PACING_RATE,
2730	* SO_PRIORITY, SO_RCVLOWAT, SO_MARK,
2731	* SO_BINDTODEVICE, SO_KEEPALIVE, SO_REUSEADDR,
2732	* SO_REUSEPORT, SO_BINDTOIFINDEX, SO_TXREHASH.
2733	* * IPPROTO_TCP, which supports the following optname\ s:
2734	* TCP_CONGESTION, TCP_BPF_IW,
2735	* TCP_BPF_SNDCWND_CLAMP, TCP_SAVE_SYN,
2736	* TCP_KEEPIDLE, TCP_KEEPINTVL, TCP_KEEPCNT,
2737	* TCP_SYNCNT, TCP_USER_TIMEOUT, TCP_NOTSENT_LOWAT,
2738	* TCP_NODELAY, TCP_MAXSEG, TCP_WINDOW_CLAMP,
2739	* TCP_THIN_LINEAR_TIMEOUTS, TCP_BPF_DELACK_MAX,
2740	* TCP_BPF_RTO_MIN.
2741	* * IPPROTO_IP, which supports optname IP_TOS.
2742	* * IPPROTO_IPV6, which supports the following optname\ s:
2743	* IPV6_TCLASS, IPV6_AUTOFLOWLABEL.
2744	* Return
2745	* 0 on success, or a negative error in case of failure.
2746	*
2747	* long bpf_skb_adjust_room(struct sk_buff *skb, s32 len_diff, u32 mode, u64 flags)
2748	* Description
2749	* Grow or shrink the room for data in the packet associated to
2750	* skb by len_diff, and according to the selected mode.
2751	*
2752	* By default, the helper will reset any offloaded checksum
2753	* indicator of the skb to CHECKSUM_NONE. This can be avoided
2754	* by the following flag:
2755	*
2756	* * BPF_F_ADJ_ROOM_NO_CSUM_RESET: Do not reset offloaded
2757	* checksum data of the skb to CHECKSUM_NONE.
2758	*
2759	* There are two supported modes at this time:
2760	*
2761	* * BPF_ADJ_ROOM_MAC: Adjust room at the mac layer
2762	* (room space is added or removed between the layer 2 and
2763	* layer 3 headers).
2764	*
2765	* * BPF_ADJ_ROOM_NET: Adjust room at the network layer
2766	* (room space is added or removed between the layer 3 and
2767	* layer 4 headers).
2768	*
2769	* The following flags are supported at this time:
2770	*
2771	* * BPF_F_ADJ_ROOM_FIXED_GSO: Do not adjust gso_size.
2772	* Adjusting mss in this way is not allowed for datagrams.
2773	*
2774	* * BPF_F_ADJ_ROOM_ENCAP_L3_IPV4,
2775	* BPF_F_ADJ_ROOM_ENCAP_L3_IPV6:
2776	* Any new space is reserved to hold a tunnel header.
2777	* Configure skb offsets and other fields accordingly.
2778	*
2779	* * BPF_F_ADJ_ROOM_ENCAP_L4_GRE,
2780	* BPF_F_ADJ_ROOM_ENCAP_L4_UDP:
2781	* Use with ENCAP_L3 flags to further specify the tunnel type.
2782	*
2783	* * BPF_F_ADJ_ROOM_ENCAP_L2\ (len):
2784	* Use with ENCAP_L3/L4 flags to further specify the tunnel
2785	* type; len is the length of the inner MAC header.
2786	*
2787	* * BPF_F_ADJ_ROOM_ENCAP_L2_ETH:
2788	* Use with BPF_F_ADJ_ROOM_ENCAP_L2 flag to further specify the
2789	* L2 type as Ethernet.
2790	*
2791	* * BPF_F_ADJ_ROOM_DECAP_L3_IPV4,
2792	* BPF_F_ADJ_ROOM_DECAP_L3_IPV6:
2793	* Indicate the new IP header version after decapsulating the outer
2794	* IP header. Used when the inner and outer IP versions are different.
2795	*
2796	* A call to this helper is susceptible to change the underlying
2797	* packet buffer. Therefore, at load time, all checks on pointers
2798	* previously done by the verifier are invalidated and must be
2799	* performed again, if the helper is used in combination with
2800	* direct packet access.
2801	* Return
2802	* 0 on success, or a negative error in case of failure.
2803	*
2804	* long bpf_redirect_map(struct bpf_map *map, u64 key, u64 flags)
2805	* Description
2806	* Redirect the packet to the endpoint referenced by map at
2807	* index key. Depending on its type, this map can contain
2808	* references to net devices (for forwarding packets through other
2809	* ports), or to CPUs (for redirecting XDP frames to another CPU;
2810	* but this is only implemented for native XDP (with driver
2811	* support) as of this writing).
2812	*
2813	* The lower two bits of flags are used as the return code if
2814	* the map lookup fails. This is so that the return value can be
2815	* one of the XDP program return codes up to XDP_TX, as chosen
2816	* by the caller. The higher bits of flags can be set to
2817	* BPF_F_BROADCAST or BPF_F_EXCLUDE_INGRESS as defined below.
2818	*
2819	* With BPF_F_BROADCAST the packet will be broadcasted to all the
2820	* interfaces in the map, with BPF_F_EXCLUDE_INGRESS the ingress
2821	* interface will be excluded when do broadcasting.
2822	*
2823	* See also bpf_redirect\ (), which only supports redirecting
2824	* to an ifindex, but doesn't require a map to do so.
2825	* Return
2826	* XDP_REDIRECT on success, or the value of the two lower bits
2827	* of the flags argument on error.
2828	*
2829	* long bpf_sk_redirect_map(struct sk_buff skb, struct bpf_map map, u32 key, u64 flags)
2830	* Description
2831	* Redirect the packet to the socket referenced by map (of type
2832	* BPF_MAP_TYPE_SOCKMAP) at index key. Both ingress and
2833	* egress interfaces can be used for redirection. The
2834	* BPF_F_INGRESS value in flags is used to make the
2835	* distinction (ingress path is selected if the flag is present,
2836	* egress path otherwise). This is the only flag supported for now.
2837	* Return
2838	* SK_PASS on success, or SK_DROP on error.
2839	*
2840	* long bpf_sock_map_update(struct bpf_sock_ops skops, struct bpf_map map, void *key, u64 flags)
2841	* Description
2842	* Add an entry to, or update a map referencing sockets. The
2843	* skops is used as a new value for the entry associated to
2844	* key. flags is one of:
2845	*
2846	* BPF_NOEXIST
2847	* The entry for key must not exist in the map.
2848	* BPF_EXIST
2849	* The entry for key must already exist in the map.
2850	* BPF_ANY
2851	* No condition on the existence of the entry for key.
2852	*
2853	* If the map has eBPF programs (parser and verdict), those will
2854	* be inherited by the socket being added. If the socket is
2855	* already attached to eBPF programs, this results in an error.
2856	* Return
2857	* 0 on success, or a negative error in case of failure.
2858	*
2859	* long bpf_xdp_adjust_meta(struct xdp_buff *xdp_md, int delta)
2860	* Description
2861	* Adjust the address pointed by xdp_md\ ->data_meta by
2862	* delta (which can be positive or negative). Note that this
2863	* operation modifies the address stored in xdp_md\ ->data,
2864	* so the latter must be loaded only after the helper has been
2865	* called.
2866	*
2867	* The use of xdp_md\ ->data_meta is optional and programs
2868	* are not required to use it. The rationale is that when the
2869	* packet is processed with XDP (e.g. as DoS filter), it is
2870	* possible to push further meta data along with it before passing
2871	* to the stack, and to give the guarantee that an ingress eBPF
2872	* program attached as a TC classifier on the same device can pick
2873	* this up for further post-processing. Since TC works with socket
2874	* buffers, it remains possible to set from XDP the mark or
2875	* priority pointers, or other pointers for the socket buffer.
2876	* Having this scratch space generic and programmable allows for
2877	* more flexibility as the user is free to store whatever meta
2878	* data they need.
2879	*
2880	* A call to this helper is susceptible to change the underlying
2881	* packet buffer. Therefore, at load time, all checks on pointers
2882	* previously done by the verifier are invalidated and must be
2883	* performed again, if the helper is used in combination with
2884	* direct packet access.
2885	* Return
2886	* 0 on success, or a negative error in case of failure.
2887	*
2888	* long bpf_perf_event_read_value(struct bpf_map map, u64 flags, struct bpf_perf_event_value buf, u32 buf_size)
2889	* Description
2890	* Read the value of a perf event counter, and store it into buf
2891	* of size buf_size. This helper relies on a map of type
2892	* BPF_MAP_TYPE_PERF_EVENT_ARRAY. The nature of the perf event
2893	* counter is selected when map is updated with perf event file
2894	* descriptors. The map is an array whose size is the number of
2895	* available CPUs, and each cell contains a value relative to one
2896	* CPU. The value to retrieve is indicated by flags, that
2897	* contains the index of the CPU to look up, masked with
2898	* BPF_F_INDEX_MASK. Alternatively, flags can be set to
2899	* BPF_F_CURRENT_CPU to indicate that the value for the
2900	* current CPU should be retrieved.
2901	*
2902	* This helper behaves in a way close to
2903	* bpf_perf_event_read\ () helper, save that instead of
2904	* just returning the value observed, it fills the buf
2905	* structure. This allows for additional data to be retrieved: in
2906	* particular, the enabled and running times (in buf\
2907	* ->enabled and buf\ ->running, respectively) are
2908	* copied. In general, bpf_perf_event_read_value\ () is
2909	* recommended over bpf_perf_event_read\ (), which has some
2910	* ABI issues and provides fewer functionalities.
2911	*
2912	* These values are interesting, because hardware PMU (Performance
2913	* Monitoring Unit) counters are limited resources. When there are
2914	* more PMU based perf events opened than available counters,
2915	* kernel will multiplex these events so each event gets certain
2916	* percentage (but not all) of the PMU time. In case that
2917	* multiplexing happens, the number of samples or counter value
2918	* will not reflect the case compared to when no multiplexing
2919	* occurs. This makes comparison between different runs difficult.
2920	* Typically, the counter value should be normalized before
2921	* comparing to other experiments. The usual normalization is done
2922	* as follows.
2923	*
2924	* ::
2925	*
2926	* normalized_counter = counter * t_enabled / t_running
2927	*
2928	* Where t_enabled is the time enabled for event and t_running is
2929	* the time running for event since last normalization. The
2930	* enabled and running times are accumulated since the perf event
2931	* open. To achieve scaling factor between two invocations of an
2932	* eBPF program, users can use CPU id as the key (which is
2933	* typical for perf array usage model) to remember the previous
2934	* value and do the calculation inside the eBPF program.
2935	* Return
2936	* 0 on success, or a negative error in case of failure.
2937	*
2938	* long bpf_perf_prog_read_value(struct bpf_perf_event_data ctx, struct bpf_perf_event_value buf, u32 buf_size)
2939	* Description
2940	* For an eBPF program attached to a perf event, retrieve the
2941	* value of the event counter associated to ctx and store it in
2942	* the structure pointed by buf and of size buf_size. Enabled
2943	* and running times are also stored in the structure (see
2944	* description of helper bpf_perf_event_read_value\ () for
2945	* more details).
2946	* Return
2947	* 0 on success, or a negative error in case of failure.
2948	*
2949	* long bpf_getsockopt(void bpf_socket, int level, int optname, void optval, int optlen)
2950	* Description
2951	* Emulate a call to getsockopt() on the socket associated to
2952	* bpf_socket, which must be a full socket. The level at
2953	* which the option resides and the name optname of the option
2954	* must be specified, see getsockopt(2) for more information.
2955	* The retrieved value is stored in the structure pointed by
2956	* opval and of length optlen.
2957	*
2958	* bpf_socket should be one of the following:
2959	*
2960	* * struct bpf_sock_ops for BPF_PROG_TYPE_SOCK_OPS.
2961	* * struct bpf_sock_addr for BPF_CGROUP_INET4_CONNECT,
2962	* BPF_CGROUP_INET6_CONNECT and BPF_CGROUP_UNIX_CONNECT.
2963	*
2964	* This helper actually implements a subset of getsockopt().
2965	* It supports the same set of optname\ s that is supported by
2966	* the bpf_setsockopt\ () helper. The exceptions are
2967	* TCP_BPF_* is bpf_setsockopt\ () only and
2968	* TCP_SAVED_SYN is bpf_getsockopt\ () only.
2969	* Return
2970	* 0 on success, or a negative error in case of failure.
2971	*
2972	* long bpf_override_return(struct pt_regs *regs, u64 rc)
2973	* Description
2974	* Used for error injection, this helper uses kprobes to override
2975	* the return value of the probed function, and to set it to rc.
2976	* The first argument is the context regs on which the kprobe
2977	* works.
2978	*
2979	* This helper works by setting the PC (program counter)
2980	* to an override function which is run in place of the original
2981	* probed function. This means the probed function is not run at
2982	* all. The replacement function just returns with the required
2983	* value.
2984	*
2985	* This helper has security implications, and thus is subject to
2986	* restrictions. It is only available if the kernel was compiled
2987	* with the CONFIG_BPF_KPROBE_OVERRIDE configuration
2988	* option, and in this case it only works on functions tagged with
2989	* ALLOW_ERROR_INJECTION in the kernel code.
2990	*
2991	* Also, the helper is only available for the architectures having
2992	* the CONFIG_FUNCTION_ERROR_INJECTION option. As of this writing,
2993	* x86 architecture is the only one to support this feature.
2994	* Return
2995	* 0
2996	*
2997	* long bpf_sock_ops_cb_flags_set(struct bpf_sock_ops *bpf_sock, int argval)
2998	* Description
2999	* Attempt to set the value of the bpf_sock_ops_cb_flags field
3000	* for the full TCP socket associated to bpf_sock_ops to
3001	* argval.
3002	*
3003	* The primary use of this field is to determine if there should
3004	* be calls to eBPF programs of type
3005	* BPF_PROG_TYPE_SOCK_OPS at various points in the TCP
3006	* code. A program of the same type can change its value, per
3007	* connection and as necessary, when the connection is
3008	* established. This field is directly accessible for reading, but
3009	* this helper must be used for updates in order to return an
3010	* error if an eBPF program tries to set a callback that is not
3011	* supported in the current kernel.
3012	*
3013	* argval is a flag array which can combine these flags:
3014	*
3015	* * BPF_SOCK_OPS_RTO_CB_FLAG (retransmission time out)
3016	* * BPF_SOCK_OPS_RETRANS_CB_FLAG (retransmission)
3017	* * BPF_SOCK_OPS_STATE_CB_FLAG (TCP state change)
3018	* * BPF_SOCK_OPS_RTT_CB_FLAG (every RTT)
3019	*
3020	* Therefore, this function can be used to clear a callback flag by
3021	* setting the appropriate bit to zero. e.g. to disable the RTO
3022	* callback:
3023	*
3024	* bpf_sock_ops_cb_flags_set(bpf_sock,
3025	* bpf_sock->bpf_sock_ops_cb_flags & ~BPF_SOCK_OPS_RTO_CB_FLAG)
3026	*
3027	* Here are some examples of where one could call such eBPF
3028	* program:
3029	*
3030	* * When RTO fires.
3031	* * When a packet is retransmitted.
3032	* * When the connection terminates.
3033	* * When a packet is sent.
3034	* * When a packet is received.
3035	* Return
3036	* Code -EINVAL if the socket is not a full TCP socket;
3037	* otherwise, a positive number containing the bits that could not
3038	* be set is returned (which comes down to 0 if all bits were set
3039	* as required).
3040	*
3041	* long bpf_msg_redirect_map(struct sk_msg_buff msg, struct bpf_map map, u32 key, u64 flags)
3042	* Description
3043	* This helper is used in programs implementing policies at the
3044	* socket level. If the message msg is allowed to pass (i.e. if
3045	* the verdict eBPF program returns SK_PASS), redirect it to
3046	* the socket referenced by map (of type
3047	* BPF_MAP_TYPE_SOCKMAP) at index key. Both ingress and
3048	* egress interfaces can be used for redirection. The
3049	* BPF_F_INGRESS value in flags is used to make the
3050	* distinction (ingress path is selected if the flag is present,
3051	* egress path otherwise). This is the only flag supported for now.
3052	* Return
3053	* SK_PASS on success, or SK_DROP on error.
3054	*
3055	* long bpf_msg_apply_bytes(struct sk_msg_buff *msg, u32 bytes)
3056	* Description
3057	* For socket policies, apply the verdict of the eBPF program to
3058	* the next bytes (number of bytes) of message msg.
3059	*
3060	* For example, this helper can be used in the following cases:
3061	*
3062	* * A single sendmsg\ () or sendfile\ () system call
3063	* contains multiple logical messages that the eBPF program is
3064	* supposed to read and for which it should apply a verdict.
3065	* * An eBPF program only cares to read the first bytes of a
3066	* msg. If the message has a large payload, then setting up
3067	* and calling the eBPF program repeatedly for all bytes, even
3068	* though the verdict is already known, would create unnecessary
3069	* overhead.
3070	*
3071	* When called from within an eBPF program, the helper sets a
3072	* counter internal to the BPF infrastructure, that is used to
3073	* apply the last verdict to the next bytes. If bytes is
3074	* smaller than the current data being processed from a
3075	* sendmsg\ () or sendfile\ () system call, the first
3076	* bytes will be sent and the eBPF program will be re-run with
3077	* the pointer for start of data pointing to byte number bytes
3078	* + 1. If bytes is larger than the current data being
3079	* processed, then the eBPF verdict will be applied to multiple
3080	* sendmsg\ () or sendfile\ () calls until bytes are
3081	* consumed.
3082	*
3083	* Note that if a socket closes with the internal counter holding
3084	* a non-zero value, this is not a problem because data is not
3085	* being buffered for bytes and is sent as it is received.
3086	* Return
3087	* 0
3088	*
3089	* long bpf_msg_cork_bytes(struct sk_msg_buff *msg, u32 bytes)
3090	* Description
3091	* For socket policies, prevent the execution of the verdict eBPF
3092	* program for message msg until bytes (byte number) have been
3093	* accumulated.
3094	*
3095	* This can be used when one needs a specific number of bytes
3096	* before a verdict can be assigned, even if the data spans
3097	* multiple sendmsg\ () or sendfile\ () calls. The extreme
3098	* case would be a user calling sendmsg\ () repeatedly with
3099	* 1-byte long message segments. Obviously, this is bad for
3100	* performance, but it is still valid. If the eBPF program needs
3101	* bytes bytes to validate a header, this helper can be used to
3102	* prevent the eBPF program to be called again until bytes have
3103	* been accumulated.
3104	* Return
3105	* 0
3106	*
3107	* long bpf_msg_pull_data(struct sk_msg_buff *msg, u32 start, u32 end, u64 flags)
3108	* Description
3109	* For socket policies, pull in non-linear data from user space
3110	* for msg and set pointers msg\ ->data and msg\
3111	* ->data_end to start and end bytes offsets into msg,
3112	* respectively.
3113	*
3114	* If a program of type BPF_PROG_TYPE_SK_MSG is run on a
3115	* msg it can only parse data that the (data, data_end)
3116	* pointers have already consumed. For sendmsg\ () hooks this
3117	* is likely the first scatterlist element. But for calls relying
3118	* on the sendpage handler (e.g. sendfile\ ()) this will
3119	* be the range (0, 0) because the data is shared with
3120	* user space and by default the objective is to avoid allowing
3121	* user space to modify data while (or after) eBPF verdict is
3122	* being decided. This helper can be used to pull in data and to
3123	* set the start and end pointer to given values. Data will be
3124	* copied if necessary (i.e. if data was not linear and if start
3125	* and end pointers do not point to the same chunk).
3126	*
3127	* A call to this helper is susceptible to change the underlying
3128	* packet buffer. Therefore, at load time, all checks on pointers
3129	* previously done by the verifier are invalidated and must be
3130	* performed again, if the helper is used in combination with
3131	* direct packet access.
3132	*
3133	* All values for flags are reserved for future usage, and must
3134	* be left at zero.
3135	* Return
3136	* 0 on success, or a negative error in case of failure.
3137	*
3138	* long bpf_bind(struct bpf_sock_addr ctx, struct sockaddr addr, int addr_len)
3139	* Description
3140	* Bind the socket associated to ctx to the address pointed by
3141	* addr, of length addr_len. This allows for making outgoing
3142	* connection from the desired IP address, which can be useful for
3143	* example when all processes inside a cgroup should use one
3144	* single IP address on a host that has multiple IP configured.
3145	*
3146	* This helper works for IPv4 and IPv6, TCP and UDP sockets. The
3147	* domain (addr\ ->sa_family) must be AF_INET (or
3148	* AF_INET6). It's advised to pass zero port (sin_port
3149	* or sin6_port) which triggers IP_BIND_ADDRESS_NO_PORT-like
3150	* behavior and lets the kernel efficiently pick up an unused
3151	* port as long as 4-tuple is unique. Passing non-zero port might
3152	* lead to degraded performance.
3153	* Return
3154	* 0 on success, or a negative error in case of failure.
3155	*
3156	* long bpf_xdp_adjust_tail(struct xdp_buff *xdp_md, int delta)
3157	* Description
3158	* Adjust (move) xdp_md\ ->data_end by delta bytes. It is
3159	* possible to both shrink and grow the packet tail.
3160	* Shrink done via delta being a negative integer.
3161	*
3162	* A call to this helper is susceptible to change the underlying
3163	* packet buffer. Therefore, at load time, all checks on pointers
3164	* previously done by the verifier are invalidated and must be
3165	* performed again, if the helper is used in combination with
3166	* direct packet access.
3167	* Return
3168	* 0 on success, or a negative error in case of failure.
3169	*
3170	* long bpf_skb_get_xfrm_state(struct sk_buff skb, u32 index, struct bpf_xfrm_state xfrm_state, u32 size, u64 flags)
3171	* Description
3172	* Retrieve the XFRM state (IP transform framework, see also
3173	* ip-xfrm(8)) at index in XFRM "security path" for skb.
3174	*
3175	* The retrieved value is stored in the struct bpf_xfrm_state
3176	* pointed by xfrm_state and of length size.
3177	*
3178	* All values for flags are reserved for future usage, and must
3179	* be left at zero.
3180	*
3181	* This helper is available only if the kernel was compiled with
3182	* CONFIG_XFRM configuration option.
3183	* Return
3184	* 0 on success, or a negative error in case of failure.
3185	*
3186	* long bpf_get_stack(void ctx, void buf, u32 size, u64 flags)
3187	* Description
3188	* Return a user or a kernel stack in bpf program provided buffer.
3189	* To achieve this, the helper needs ctx, which is a pointer
3190	* to the context on which the tracing program is executed.
3191	* To store the stacktrace, the bpf program provides buf with
3192	* a nonnegative size.
3193	*
3194	* The last argument, flags, holds the number of stack frames to
3195	* skip (from 0 to 255), masked with
3196	* BPF_F_SKIP_FIELD_MASK. The next bits can be used to set
3197	* the following flags:
3198	*
3199	* BPF_F_USER_STACK
3200	* Collect a user space stack instead of a kernel stack.
3201	* BPF_F_USER_BUILD_ID
3202	* Collect (build_id, file_offset) instead of ips for user
3203	* stack, only valid if BPF_F_USER_STACK is also
3204	* specified.
3205	*
3206	* file_offset is an offset relative to the beginning
3207	* of the executable or shared object file backing the vma
3208	* which the ip falls in. It is not an offset relative
3209	* to that object's base address. Accordingly, it must be
3210	* adjusted by adding (sh_addr - sh_offset), where
3211	* sh_{addr,offset} correspond to the executable section
3212	* containing file_offset in the object, for comparisons
3213	* to symbols' st_value to be valid.
3214	*
3215	* bpf_get_stack\ () can collect up to
3216	* PERF_MAX_STACK_DEPTH both kernel and user frames, subject
3217	* to sufficient large buffer size. Note that
3218	* this limit can be controlled with the sysctl program, and
3219	* that it should be manually increased in order to profile long
3220	* user stacks (such as stacks for Java programs). To do so, use:
3221	*
3222	* ::
3223	*
3224	* # sysctl kernel.perf_event_max_stack=<new value>
3225	* Return
3226	* The non-negative copied buf length equal to or less than
3227	* size on success, or a negative error in case of failure.
3228	*
3229	* long bpf_skb_load_bytes_relative(const void skb, u32 offset, void to, u32 len, u32 start_header)
3230	* Description
3231	* This helper is similar to bpf_skb_load_bytes\ () in that
3232	* it provides an easy way to load len bytes from offset
3233	* from the packet associated to skb, into the buffer pointed
3234	* by to. The difference to bpf_skb_load_bytes\ () is that
3235	* a fifth argument start_header exists in order to select a
3236	* base offset to start from. start_header can be one of:
3237	*
3238	* BPF_HDR_START_MAC
3239	* Base offset to load data from is skb's mac header.
3240	* BPF_HDR_START_NET
3241	* Base offset to load data from is skb's network header.
3242	*
3243	* In general, "direct packet access" is the preferred method to
3244	* access packet data, however, this helper is in particular useful
3245	* in socket filters where skb\ ->data does not always point
3246	* to the start of the mac header and where "direct packet access"
3247	* is not available.
3248	* Return
3249	* 0 on success, or a negative error in case of failure.
3250	*
3251	* long bpf_fib_lookup(void ctx, struct bpf_fib_lookup params, int plen, u32 flags)
3252	* Description
3253	* Do FIB lookup in kernel tables using parameters in params.
3254	* If lookup is successful and result shows packet is to be
3255	* forwarded, the neighbor tables are searched for the nexthop.
3256	* If successful (ie., FIB lookup shows forwarding and nexthop
3257	* is resolved), the nexthop address is returned in ipv4_dst
3258	* or ipv6_dst based on family, smac is set to mac address of
3259	* egress device, dmac is set to nexthop mac address, rt_metric
3260	* is set to metric from route (IPv4/IPv6 only), and ifindex
3261	* is set to the device index of the nexthop from the FIB lookup.
3262	*
3263	* plen argument is the size of the passed in struct.
3264	* flags argument can be a combination of one or more of the
3265	* following values:
3266	*
3267	* BPF_FIB_LOOKUP_DIRECT
3268	* Do a direct table lookup vs full lookup using FIB
3269	* rules.
3270	* BPF_FIB_LOOKUP_TBID
3271	* Used with BPF_FIB_LOOKUP_DIRECT.
3272	* Use the routing table ID present in params->tbid
3273	* for the fib lookup.
3274	* BPF_FIB_LOOKUP_OUTPUT
3275	* Perform lookup from an egress perspective (default is
3276	* ingress).
3277	* BPF_FIB_LOOKUP_SKIP_NEIGH
3278	* Skip the neighbour table lookup. params->dmac
3279	* and params->smac will not be set as output. A common
3280	* use case is to call bpf_redirect_neigh\ () after
3281	* doing bpf_fib_lookup\ ().
3282	* BPF_FIB_LOOKUP_SRC
3283	* Derive and set source IP addr in params->ipv{4,6}_src
3284	* for the nexthop. If the src addr cannot be derived,
3285	* BPF_FIB_LKUP_RET_NO_SRC_ADDR is returned. In this
3286	* case, params->dmac and params->smac are not set either.
3287	*
3288	* ctx is either struct xdp_md for XDP programs or
3289	* struct sk_buff tc cls_act programs.
3290	* Return
3291	* * < 0 if any input argument is invalid
3292	* * 0 on success (packet is forwarded, nexthop neighbor exists)
3293	* * > 0 one of BPF_FIB_LKUP_RET_ codes explaining why the
3294	* packet is not forwarded or needs assist from full stack
3295	*
3296	* If lookup fails with BPF_FIB_LKUP_RET_FRAG_NEEDED, then the MTU
3297	* was exceeded and output params->mtu_result contains the MTU.
3298	*
3299	* long bpf_sock_hash_update(struct bpf_sock_ops skops, struct bpf_map map, void *key, u64 flags)
3300	* Description
3301	* Add an entry to, or update a sockhash map referencing sockets.
3302	* The skops is used as a new value for the entry associated to
3303	* key. flags is one of:
3304	*
3305	* BPF_NOEXIST
3306	* The entry for key must not exist in the map.
3307	* BPF_EXIST
3308	* The entry for key must already exist in the map.
3309	* BPF_ANY
3310	* No condition on the existence of the entry for key.
3311	*
3312	* If the map has eBPF programs (parser and verdict), those will
3313	* be inherited by the socket being added. If the socket is
3314	* already attached to eBPF programs, this results in an error.
3315	* Return
3316	* 0 on success, or a negative error in case of failure.
3317	*
3318	* long bpf_msg_redirect_hash(struct sk_msg_buff msg, struct bpf_map map, void *key, u64 flags)
3319	* Description
3320	* This helper is used in programs implementing policies at the
3321	* socket level. If the message msg is allowed to pass (i.e. if
3322	* the verdict eBPF program returns SK_PASS), redirect it to
3323	* the socket referenced by map (of type
3324	* BPF_MAP_TYPE_SOCKHASH) using hash key. Both ingress and
3325	* egress interfaces can be used for redirection. The
3326	* BPF_F_INGRESS value in flags is used to make the
3327	* distinction (ingress path is selected if the flag is present,
3328	* egress path otherwise). This is the only flag supported for now.
3329	* Return
3330	* SK_PASS on success, or SK_DROP on error.
3331	*
3332	* long bpf_sk_redirect_hash(struct sk_buff skb, struct bpf_map map, void *key, u64 flags)
3333	* Description
3334	* This helper is used in programs implementing policies at the
3335	* skb socket level. If the sk_buff skb is allowed to pass (i.e.
3336	* if the verdict eBPF program returns SK_PASS), redirect it
3337	* to the socket referenced by map (of type
3338	* BPF_MAP_TYPE_SOCKHASH) using hash key. Both ingress and
3339	* egress interfaces can be used for redirection. The
3340	* BPF_F_INGRESS value in flags is used to make the
3341	* distinction (ingress path is selected if the flag is present,
3342	* egress otherwise). This is the only flag supported for now.
3343	* Return
3344	* SK_PASS on success, or SK_DROP on error.
3345	*
3346	* long bpf_lwt_push_encap(struct sk_buff skb, u32 type, void hdr, u32 len)
3347	* Description
3348	* Encapsulate the packet associated to skb within a Layer 3
3349	* protocol header. This header is provided in the buffer at
3350	* address hdr, with len its size in bytes. type indicates
3351	* the protocol of the header and can be one of:
3352	*
3353	* BPF_LWT_ENCAP_SEG6
3354	* IPv6 encapsulation with Segment Routing Header
3355	* (struct ipv6_sr_hdr). hdr only contains the SRH,
3356	* the IPv6 header is computed by the kernel.
3357	* BPF_LWT_ENCAP_SEG6_INLINE
3358	* Only works if skb contains an IPv6 packet. Insert a
3359	* Segment Routing Header (struct ipv6_sr_hdr) inside
3360	* the IPv6 header.
3361	* BPF_LWT_ENCAP_IP
3362	* IP encapsulation (GRE/GUE/IPIP/etc). The outer header
3363	* must be IPv4 or IPv6, followed by zero or more
3364	* additional headers, up to LWT_BPF_MAX_HEADROOM
3365	* total bytes in all prepended headers. Please note that
3366	* if skb_is_gso\ (skb) is true, no more than two
3367	* headers can be prepended, and the inner header, if
3368	* present, should be either GRE or UDP/GUE.
3369	*
3370	* BPF_LWT_ENCAP_SEG6\ \* types can be called by BPF programs
3371	* of type BPF_PROG_TYPE_LWT_IN; BPF_LWT_ENCAP_IP type can
3372	* be called by bpf programs of types BPF_PROG_TYPE_LWT_IN and
3373	* BPF_PROG_TYPE_LWT_XMIT.
3374	*
3375	* A call to this helper is susceptible to change the underlying
3376	* packet buffer. Therefore, at load time, all checks on pointers
3377	* previously done by the verifier are invalidated and must be
3378	* performed again, if the helper is used in combination with
3379	* direct packet access.
3380	* Return
3381	* 0 on success, or a negative error in case of failure.
3382	*
3383	* long bpf_lwt_seg6_store_bytes(struct sk_buff skb, u32 offset, const void from, u32 len)
3384	* Description
3385	* Store len bytes from address from into the packet
3386	* associated to skb, at offset. Only the flags, tag and TLVs
3387	* inside the outermost IPv6 Segment Routing Header can be
3388	* modified through this helper.
3389	*
3390	* A call to this helper is susceptible to change the underlying
3391	* packet buffer. Therefore, at load time, all checks on pointers
3392	* previously done by the verifier are invalidated and must be
3393	* performed again, if the helper is used in combination with
3394	* direct packet access.
3395	* Return
3396	* 0 on success, or a negative error in case of failure.
3397	*
3398	* long bpf_lwt_seg6_adjust_srh(struct sk_buff *skb, u32 offset, s32 delta)
3399	* Description
3400	* Adjust the size allocated to TLVs in the outermost IPv6
3401	* Segment Routing Header contained in the packet associated to
3402	* skb, at position offset by delta bytes. Only offsets
3403	* after the segments are accepted. delta can be as well
3404	* positive (growing) as negative (shrinking).
3405	*
3406	* A call to this helper is susceptible to change the underlying
3407	* packet buffer. Therefore, at load time, all checks on pointers
3408	* previously done by the verifier are invalidated and must be
3409	* performed again, if the helper is used in combination with
3410	* direct packet access.
3411	* Return
3412	* 0 on success, or a negative error in case of failure.
3413	*
3414	* long bpf_lwt_seg6_action(struct sk_buff skb, u32 action, void param, u32 param_len)
3415	* Description
3416	* Apply an IPv6 Segment Routing action of type action to the
3417	* packet associated to skb. Each action takes a parameter
3418	* contained at address param, and of length param_len bytes.
3419	* action can be one of:
3420	*
3421	* SEG6_LOCAL_ACTION_END_X
3422	* End.X action: Endpoint with Layer-3 cross-connect.
3423	* Type of param: struct in6_addr.
3424	* SEG6_LOCAL_ACTION_END_T
3425	* End.T action: Endpoint with specific IPv6 table lookup.
3426	* Type of param: int.
3427	* SEG6_LOCAL_ACTION_END_B6
3428	* End.B6 action: Endpoint bound to an SRv6 policy.
3429	* Type of param: struct ipv6_sr_hdr.
3430	* SEG6_LOCAL_ACTION_END_B6_ENCAP
3431	* End.B6.Encap action: Endpoint bound to an SRv6
3432	* encapsulation policy.
3433	* Type of param: struct ipv6_sr_hdr.
3434	*
3435	* A call to this helper is susceptible to change the underlying
3436	* packet buffer. Therefore, at load time, all checks on pointers
3437	* previously done by the verifier are invalidated and must be
3438	* performed again, if the helper is used in combination with
3439	* direct packet access.
3440	* Return
3441	* 0 on success, or a negative error in case of failure.
3442	*
3443	* long bpf_rc_repeat(void *ctx)
3444	* Description
3445	* This helper is used in programs implementing IR decoding, to
3446	* report a successfully decoded repeat key message. This delays
3447	* the generation of a key up event for previously generated
3448	* key down event.
3449	*
3450	* Some IR protocols like NEC have a special IR message for
3451	* repeating last button, for when a button is held down.
3452	*
3453	* The ctx should point to the lirc sample as passed into
3454	* the program.
3455	*
3456	* This helper is only available is the kernel was compiled with
3457	* the CONFIG_BPF_LIRC_MODE2 configuration option set to
3458	* "y".
3459	* Return
3460	* 0
3461	*
3462	* long bpf_rc_keydown(void *ctx, u32 protocol, u64 scancode, u32 toggle)
3463	* Description
3464	* This helper is used in programs implementing IR decoding, to
3465	* report a successfully decoded key press with scancode,
3466	* toggle value in the given protocol. The scancode will be
3467	* translated to a keycode using the rc keymap, and reported as
3468	* an input key down event. After a period a key up event is
3469	* generated. This period can be extended by calling either
3470	* bpf_rc_keydown\ () again with the same values, or calling
3471	* bpf_rc_repeat\ ().
3472	*
3473	* Some protocols include a toggle bit, in case the button was
3474	* released and pressed again between consecutive scancodes.
3475	*
3476	* The ctx should point to the lirc sample as passed into
3477	* the program.
3478	*
3479	* The protocol is the decoded protocol number (see
3480	* enum rc_proto for some predefined values).
3481	*
3482	* This helper is only available is the kernel was compiled with
3483	* the CONFIG_BPF_LIRC_MODE2 configuration option set to
3484	* "y".
3485	* Return
3486	* 0
3487	*
3488	* u64 bpf_skb_cgroup_id(struct sk_buff *skb)
3489	* Description
3490	* Return the cgroup v2 id of the socket associated with the skb.
3491	* This is roughly similar to the bpf_get_cgroup_classid\ ()
3492	* helper for cgroup v1 by providing a tag resp. identifier that
3493	* can be matched on or used for map lookups e.g. to implement
3494	* policy. The cgroup v2 id of a given path in the hierarchy is
3495	* exposed in user space through the f_handle API in order to get
3496	* to the same 64-bit id.
3497	*
3498	* This helper can be used on TC egress path, but not on ingress,
3499	* and is available only if the kernel was compiled with the
3500	* CONFIG_SOCK_CGROUP_DATA configuration option.
3501	* Return
3502	* The id is returned or 0 in case the id could not be retrieved.
3503	*
3504	* u64 bpf_get_current_cgroup_id(void)
3505	* Description
3506	* Get the current cgroup id based on the cgroup within which
3507	* the current task is running.
3508	* Return
3509	* A 64-bit integer containing the current cgroup id based
3510	* on the cgroup within which the current task is running.
3511	*
3512	* void bpf_get_local_storage(void map, u64 flags)
3513	* Description
3514	* Get the pointer to the local storage area.
3515	* The type and the size of the local storage is defined
3516	* by the map argument.
3517	* The flags meaning is specific for each map type,
3518	* and has to be 0 for cgroup local storage.
3519	*
3520	* Depending on the BPF program type, a local storage area
3521	* can be shared between multiple instances of the BPF program,
3522	* running simultaneously.
3523	*
3524	* A user should care about the synchronization by himself.
3525	* For example, by using the BPF_ATOMIC instructions to alter
3526	* the shared data.
3527	* Return
3528	* A pointer to the local storage area.
3529	*
3530	* long bpf_sk_select_reuseport(struct sk_reuseport_md reuse, struct bpf_map map, void *key, u64 flags)
3531	* Description
3532	* Select a SO_REUSEPORT socket from a
3533	* BPF_MAP_TYPE_REUSEPORT_SOCKARRAY map.
3534	* It checks the selected socket is matching the incoming
3535	* request in the socket buffer.
3536	* Return
3537	* 0 on success, or a negative error in case of failure.
3538	*
3539	* u64 bpf_skb_ancestor_cgroup_id(struct sk_buff *skb, int ancestor_level)
3540	* Description
3541	* Return id of cgroup v2 that is ancestor of cgroup associated
3542	* with the skb at the ancestor_level. The root cgroup is at
3543	* ancestor_level zero and each step down the hierarchy
3544	* increments the level. If ancestor_level == level of cgroup
3545	* associated with skb, then return value will be same as that
3546	* of bpf_skb_cgroup_id\ ().
3547	*
3548	* The helper is useful to implement policies based on cgroups
3549	* that are upper in hierarchy than immediate cgroup associated
3550	* with skb.
3551	*
3552	* The format of returned id and helper limitations are same as in
3553	* bpf_skb_cgroup_id\ ().
3554	* Return
3555	* The id is returned or 0 in case the id could not be retrieved.
3556	*
3557	* struct bpf_sock bpf_sk_lookup_tcp(void ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
3558	* Description
3559	* Look for TCP socket matching tuple, optionally in a child
3560	* network namespace netns. The return value must be checked,
3561	* and if non-NULL, released via bpf_sk_release\ ().
3562	*
3563	* The ctx should point to the context of the program, such as
3564	* the skb or socket (depending on the hook in use). This is used
3565	* to determine the base network namespace for the lookup.
3566	*
3567	* tuple_size must be one of:
3568	*
3569	* sizeof\ (tuple\ ->ipv4)
3570	* Look for an IPv4 socket.
3571	* sizeof\ (tuple\ ->ipv6)
3572	* Look for an IPv6 socket.
3573	*
3574	* If the netns is a negative signed 32-bit integer, then the
3575	* socket lookup table in the netns associated with the ctx
3576	* will be used. For the TC hooks, this is the netns of the device
3577	* in the skb. For socket hooks, this is the netns of the socket.
3578	* If netns is any other signed 32-bit value greater than or
3579	* equal to zero then it specifies the ID of the netns relative to
3580	* the netns associated with the ctx. netns values beyond the
3581	* range of 32-bit integers are reserved for future use.
3582	*
3583	* All values for flags are reserved for future usage, and must
3584	* be left at zero.
3585	*
3586	* This helper is available only if the kernel was compiled with
3587	* CONFIG_NET configuration option.
3588	* Return
3589	* Pointer to struct bpf_sock, or NULL in case of failure.
3590	* For sockets with reuseport option, the struct bpf_sock
3591	* result is from reuse\ ->socks\ [] using the hash of the
3592	* tuple.
3593	*
3594	* struct bpf_sock bpf_sk_lookup_udp(void ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
3595	* Description
3596	* Look for UDP socket matching tuple, optionally in a child
3597	* network namespace netns. The return value must be checked,
3598	* and if non-NULL, released via bpf_sk_release\ ().
3599	*
3600	* The ctx should point to the context of the program, such as
3601	* the skb or socket (depending on the hook in use). This is used
3602	* to determine the base network namespace for the lookup.
3603	*
3604	* tuple_size must be one of:
3605	*
3606	* sizeof\ (tuple\ ->ipv4)
3607	* Look for an IPv4 socket.
3608	* sizeof\ (tuple\ ->ipv6)
3609	* Look for an IPv6 socket.
3610	*
3611	* If the netns is a negative signed 32-bit integer, then the
3612	* socket lookup table in the netns associated with the ctx
3613	* will be used. For the TC hooks, this is the netns of the device
3614	* in the skb. For socket hooks, this is the netns of the socket.
3615	* If netns is any other signed 32-bit value greater than or
3616	* equal to zero then it specifies the ID of the netns relative to
3617	* the netns associated with the ctx. netns values beyond the
3618	* range of 32-bit integers are reserved for future use.
3619	*
3620	* All values for flags are reserved for future usage, and must
3621	* be left at zero.
3622	*
3623	* This helper is available only if the kernel was compiled with
3624	* CONFIG_NET configuration option.
3625	* Return
3626	* Pointer to struct bpf_sock, or NULL in case of failure.
3627	* For sockets with reuseport option, the struct bpf_sock
3628	* result is from reuse\ ->socks\ [] using the hash of the
3629	* tuple.
3630	*
3631	* long bpf_sk_release(void *sock)
3632	* Description
3633	* Release the reference held by sock. sock must be a
3634	* non-NULL pointer that was returned from
3635	* bpf_sk_lookup_xxx\ ().
3636	* Return
3637	* 0 on success, or a negative error in case of failure.
3638	*
3639	* long bpf_map_push_elem(struct bpf_map map, const void value, u64 flags)
3640	* Description
3641	* Push an element value in map. flags is one of:
3642	*
3643	* BPF_EXIST
3644	* If the queue/stack is full, the oldest element is
3645	* removed to make room for this.
3646	* Return
3647	* 0 on success, or a negative error in case of failure.
3648	*
3649	* long bpf_map_pop_elem(struct bpf_map map, void value)
3650	* Description
3651	* Pop an element from map.
3652	* Return
3653	* 0 on success, or a negative error in case of failure.
3654	*
3655	* long bpf_map_peek_elem(struct bpf_map map, void value)
3656	* Description
3657	* Get an element from map without removing it.
3658	* Return
3659	* 0 on success, or a negative error in case of failure.
3660	*
3661	* long bpf_msg_push_data(struct sk_msg_buff *msg, u32 start, u32 len, u64 flags)
3662	* Description
3663	* For socket policies, insert len bytes into msg at offset
3664	* start.
3665	*
3666	* If a program of type BPF_PROG_TYPE_SK_MSG is run on a
3667	* msg it may want to insert metadata or options into the msg.
3668	* This can later be read and used by any of the lower layer BPF
3669	* hooks.
3670	*
3671	* This helper may fail if under memory pressure (a malloc
3672	* fails) in these cases BPF programs will get an appropriate
3673	* error and BPF programs will need to handle them.
3674	* Return
3675	* 0 on success, or a negative error in case of failure.
3676	*
3677	* long bpf_msg_pop_data(struct sk_msg_buff *msg, u32 start, u32 len, u64 flags)
3678	* Description
3679	* Will remove len bytes from a msg starting at byte start.
3680	* This may result in ENOMEM errors under certain situations if
3681	* an allocation and copy are required due to a full ring buffer.
3682	* However, the helper will try to avoid doing the allocation
3683	* if possible. Other errors can occur if input parameters are
3684	* invalid either due to start byte not being valid part of msg
3685	* payload and/or pop value being to large.
3686	* Return
3687	* 0 on success, or a negative error in case of failure.
3688	*
3689	* long bpf_rc_pointer_rel(void *ctx, s32 rel_x, s32 rel_y)
3690	* Description
3691	* This helper is used in programs implementing IR decoding, to
3692	* report a successfully decoded pointer movement.
3693	*
3694	* The ctx should point to the lirc sample as passed into
3695	* the program.
3696	*
3697	* This helper is only available is the kernel was compiled with
3698	* the CONFIG_BPF_LIRC_MODE2 configuration option set to
3699	* "y".
3700	* Return
3701	* 0
3702	*
3703	* long bpf_spin_lock(struct bpf_spin_lock *lock)
3704	* Description
3705	* Acquire a spinlock represented by the pointer lock, which is
3706	* stored as part of a value of a map. Taking the lock allows to
3707	* safely update the rest of the fields in that value. The
3708	* spinlock can (and must) later be released with a call to
3709	* bpf_spin_unlock\ (\ lock\ ).
3710	*
3711	* Spinlocks in BPF programs come with a number of restrictions
3712	* and constraints:
3713	*
3714	* * bpf_spin_lock objects are only allowed inside maps of
3715	* types BPF_MAP_TYPE_HASH and BPF_MAP_TYPE_ARRAY (this
3716	* list could be extended in the future).
3717	* * BTF description of the map is mandatory.
3718	* * The BPF program can take ONE lock at a time, since taking two
3719	* or more could cause dead locks.
3720	* * Only one struct bpf_spin_lock is allowed per map element.
3721	* * When the lock is taken, calls (either BPF to BPF or helpers)
3722	* are not allowed.
3723	* * The BPF_LD_ABS and BPF_LD_IND instructions are not
3724	* allowed inside a spinlock-ed region.
3725	* * The BPF program MUST call bpf_spin_unlock\ () to release
3726	* the lock, on all execution paths, before it returns.
3727	* * The BPF program can access struct bpf_spin_lock only via
3728	* the bpf_spin_lock\ () and bpf_spin_unlock\ ()
3729	* helpers. Loading or storing data into the **struct
3730	* bpf_spin_lock** lock\ ; field of a map is not allowed.
3731	* * To use the bpf_spin_lock\ () helper, the BTF description
3732	* of the map value must be a struct and have **struct
3733	* bpf_spin_lock** anyname\ ; field at the top level.
3734	* Nested lock inside another struct is not allowed.
3735	* * The struct bpf_spin_lock lock field in a map value must
3736	* be aligned on a multiple of 4 bytes in that value.
3737	* * Syscall with command BPF_MAP_LOOKUP_ELEM does not copy
3738	* the bpf_spin_lock field to user space.
3739	* * Syscall with command BPF_MAP_UPDATE_ELEM, or update from
3740	* a BPF program, do not update the bpf_spin_lock field.
3741	* * bpf_spin_lock cannot be on the stack or inside a
3742	* networking packet (it can only be inside of a map values).
3743	* * bpf_spin_lock is available to root only.
3744	* * Tracing programs and socket filter programs cannot use
3745	* bpf_spin_lock\ () due to insufficient preemption checks
3746	* (but this may change in the future).
3747	* * bpf_spin_lock is not allowed in inner maps of map-in-map.
3748	* Return
3749	* 0
3750	*
3751	* long bpf_spin_unlock(struct bpf_spin_lock *lock)
3752	* Description
3753	* Release the lock previously locked by a call to
3754	* bpf_spin_lock\ (\ lock\ ).
3755	* Return
3756	* 0
3757	*
3758	* struct bpf_sock bpf_sk_fullsock(struct bpf_sock sk)
3759	* Description
3760	* This helper gets a struct bpf_sock pointer such
3761	* that all the fields in this bpf_sock can be accessed.
3762	* Return
3763	* A struct bpf_sock pointer on success, or NULL in
3764	* case of failure.
3765	*
3766	* struct bpf_tcp_sock bpf_tcp_sock(struct bpf_sock sk)
3767	* Description
3768	* This helper gets a struct bpf_tcp_sock pointer from a
3769	* struct bpf_sock pointer.
3770	* Return
3771	* A struct bpf_tcp_sock pointer on success, or NULL in
3772	* case of failure.
3773	*
3774	* long bpf_skb_ecn_set_ce(struct sk_buff *skb)
3775	* Description
3776	* Set ECN (Explicit Congestion Notification) field of IP header
3777	* to CE (Congestion Encountered) if current value is ECT
3778	* (ECN Capable Transport). Otherwise, do nothing. Works with IPv6
3779	* and IPv4.
3780	* Return
3781	* 1 if the CE flag is set (either by the current helper call
3782	* or because it was already present), 0 if it is not set.
3783	*
3784	* struct bpf_sock bpf_get_listener_sock(struct bpf_sock sk)
3785	* Description
3786	* Return a struct bpf_sock pointer in TCP_LISTEN state.
3787	* bpf_sk_release\ () is unnecessary and not allowed.
3788	* Return
3789	* A struct bpf_sock pointer on success, or NULL in
3790	* case of failure.
3791	*
3792	* struct bpf_sock bpf_skc_lookup_tcp(void ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
3793	* Description
3794	* Look for TCP socket matching tuple, optionally in a child
3795	* network namespace netns. The return value must be checked,
3796	* and if non-NULL, released via bpf_sk_release\ ().
3797	*
3798	* This function is identical to bpf_sk_lookup_tcp\ (), except
3799	* that it also returns timewait or request sockets. Use
3800	* bpf_sk_fullsock\ () or bpf_tcp_sock\ () to access the
3801	* full structure.
3802	*
3803	* This helper is available only if the kernel was compiled with
3804	* CONFIG_NET configuration option.
3805	* Return
3806	* Pointer to struct bpf_sock, or NULL in case of failure.
3807	* For sockets with reuseport option, the struct bpf_sock
3808	* result is from reuse\ ->socks\ [] using the hash of the
3809	* tuple.
3810	*
3811	* long bpf_tcp_check_syncookie(void sk, void iph, u32 iph_len, struct tcphdr *th, u32 th_len)
3812	* Description
3813	* Check whether iph and th contain a valid SYN cookie ACK for
3814	* the listening socket in sk.
3815	*
3816	* iph points to the start of the IPv4 or IPv6 header, while
3817	* iph_len contains sizeof\ (struct iphdr) or
3818	* sizeof\ (struct ipv6hdr).
3819	*
3820	* th points to the start of the TCP header, while th_len
3821	* contains the length of the TCP header (at least
3822	* sizeof\ (struct tcphdr)).
3823	* Return
3824	* 0 if iph and th are a valid SYN cookie ACK, or a negative
3825	* error otherwise.
3826	*
3827	* long bpf_sysctl_get_name(struct bpf_sysctl ctx, char buf, size_t buf_len, u64 flags)
3828	* Description
3829	* Get name of sysctl in /proc/sys/ and copy it into provided by
3830	* program buffer buf of size buf_len.
3831	*
3832	* The buffer is always NUL terminated, unless it's zero-sized.
3833	*
3834	* If flags is zero, full name (e.g. "net/ipv4/tcp_mem") is
3835	* copied. Use BPF_F_SYSCTL_BASE_NAME flag to copy base name
3836	* only (e.g. "tcp_mem").
3837	* Return
3838	* Number of character copied (not including the trailing NUL).
3839	*
3840	* -E2BIG if the buffer wasn't big enough (buf will contain
3841	* truncated name in this case).
3842	*
3843	* long bpf_sysctl_get_current_value(struct bpf_sysctl ctx, char buf, size_t buf_len)
3844	* Description
3845	* Get current value of sysctl as it is presented in /proc/sys
3846	* (incl. newline, etc), and copy it as a string into provided
3847	* by program buffer buf of size buf_len.
3848	*
3849	* The whole value is copied, no matter what file position user
3850	* space issued e.g. sys_read at.
3851	*
3852	* The buffer is always NUL terminated, unless it's zero-sized.
3853	* Return
3854	* Number of character copied (not including the trailing NUL).
3855	*
3856	* -E2BIG if the buffer wasn't big enough (buf will contain
3857	* truncated name in this case).
3858	*
3859	* -EINVAL if current value was unavailable, e.g. because
3860	* sysctl is uninitialized and read returns -EIO for it.
3861	*
3862	* long bpf_sysctl_get_new_value(struct bpf_sysctl ctx, char buf, size_t buf_len)
3863	* Description
3864	* Get new value being written by user space to sysctl (before
3865	* the actual write happens) and copy it as a string into
3866	* provided by program buffer buf of size buf_len.
3867	*
3868	* User space may write new value at file position > 0.
3869	*
3870	* The buffer is always NUL terminated, unless it's zero-sized.
3871	* Return
3872	* Number of character copied (not including the trailing NUL).
3873	*
3874	* -E2BIG if the buffer wasn't big enough (buf will contain
3875	* truncated name in this case).
3876	*
3877	* -EINVAL if sysctl is being read.
3878	*
3879	* long bpf_sysctl_set_new_value(struct bpf_sysctl ctx, const char buf, size_t buf_len)
3880	* Description
3881	* Override new value being written by user space to sysctl with
3882	* value provided by program in buffer buf of size buf_len.
3883	*
3884	* buf should contain a string in same form as provided by user
3885	* space on sysctl write.
3886	*
3887	* User space may write new value at file position > 0. To override
3888	* the whole sysctl value file position should be set to zero.
3889	* Return
3890	* 0 on success.
3891	*
3892	* -E2BIG if the buf_len is too big.
3893	*
3894	* -EINVAL if sysctl is being read.
3895	*
3896	* long bpf_strtol(const char buf, size_t buf_len, u64 flags, long res)
3897	* Description
3898	* Convert the initial part of the string from buffer buf of
3899	* size buf_len to a long integer according to the given base
3900	* and save the result in res.
3901	*
3902	* The string may begin with an arbitrary amount of white space
3903	* (as determined by isspace\ (3)) followed by a single
3904	* optional '-' sign.
3905	*
3906	* Five least significant bits of flags encode base, other bits
3907	* are currently unused.
3908	*
3909	* Base must be either 8, 10, 16 or 0 to detect it automatically
3910	* similar to user space strtol\ (3).
3911	* Return
3912	* Number of characters consumed on success. Must be positive but
3913	* no more than buf_len.
3914	*
3915	* -EINVAL if no valid digits were found or unsupported base
3916	* was provided.
3917	*
3918	* -ERANGE if resulting value was out of range.
3919	*
3920	* long bpf_strtoul(const char buf, size_t buf_len, u64 flags, unsigned long res)
3921	* Description
3922	* Convert the initial part of the string from buffer buf of
3923	* size buf_len to an unsigned long integer according to the
3924	* given base and save the result in res.
3925	*
3926	* The string may begin with an arbitrary amount of white space
3927	* (as determined by isspace\ (3)).
3928	*
3929	* Five least significant bits of flags encode base, other bits
3930	* are currently unused.
3931	*
3932	* Base must be either 8, 10, 16 or 0 to detect it automatically
3933	* similar to user space strtoul\ (3).
3934	* Return
3935	* Number of characters consumed on success. Must be positive but
3936	* no more than buf_len.
3937	*
3938	* -EINVAL if no valid digits were found or unsupported base
3939	* was provided.
3940	*
3941	* -ERANGE if resulting value was out of range.
3942	*
3943	* void bpf_sk_storage_get(struct bpf_map map, void sk, void value, u64 flags)
3944	* Description
3945	* Get a bpf-local-storage from a sk.
3946	*
3947	* Logically, it could be thought of getting the value from
3948	* a map with sk as the key. From this
3949	* perspective, the usage is not much different from
3950	* bpf_map_lookup_elem\ (map, &\ sk) except this
3951	* helper enforces the key must be a full socket and the map must
3952	* be a BPF_MAP_TYPE_SK_STORAGE also.
3953	*
3954	* Underneath, the value is stored locally at sk instead of
3955	* the map. The map is used as the bpf-local-storage
3956	* "type". The bpf-local-storage "type" (i.e. the map) is
3957	* searched against all bpf-local-storages residing at sk.
3958	*
3959	* sk is a kernel struct sock pointer for LSM program.
3960	* sk is a struct bpf_sock pointer for other program types.
3961	*
3962	* An optional flags (BPF_SK_STORAGE_GET_F_CREATE) can be
3963	* used such that a new bpf-local-storage will be
3964	* created if one does not exist. value can be used
3965	* together with BPF_SK_STORAGE_GET_F_CREATE to specify
3966	* the initial value of a bpf-local-storage. If value is
3967	* NULL, the new bpf-local-storage will be zero initialized.
3968	* Return
3969	* A bpf-local-storage pointer is returned on success.
3970	*
3971	* NULL if not found or there was an error in adding
3972	* a new bpf-local-storage.
3973	*
3974	* long bpf_sk_storage_delete(struct bpf_map map, void sk)
3975	* Description
3976	* Delete a bpf-local-storage from a sk.
3977	* Return
3978	* 0 on success.
3979	*
3980	* -ENOENT if the bpf-local-storage cannot be found.
3981	* -EINVAL if sk is not a fullsock (e.g. a request_sock).
3982	*
3983	* long bpf_send_signal(u32 sig)
3984	* Description
3985	* Send signal sig to the process of the current task.
3986	* The signal may be delivered to any of this process's threads.
3987	* Return
3988	* 0 on success or successfully queued.
3989	*
3990	* -EBUSY if work queue under nmi is full.
3991	*
3992	* -EINVAL if sig is invalid.
3993	*
3994	* -EPERM if no permission to send the sig.
3995	*
3996	* -EAGAIN if bpf program can try again.
3997	*
3998	* s64 bpf_tcp_gen_syncookie(void sk, void iph, u32 iph_len, struct tcphdr *th, u32 th_len)
3999	* Description
4000	* Try to issue a SYN cookie for the packet with corresponding
4001	* IP/TCP headers, iph and th, on the listening socket in sk.
4002	*
4003	* iph points to the start of the IPv4 or IPv6 header, while
4004	* iph_len contains sizeof\ (struct iphdr) or
4005	* sizeof\ (struct ipv6hdr).
4006	*
4007	* th points to the start of the TCP header, while th_len
4008	* contains the length of the TCP header with options (at least
4009	* sizeof\ (struct tcphdr)).
4010	* Return
4011	* On success, lower 32 bits hold the generated SYN cookie in
4012	* followed by 16 bits which hold the MSS value for that cookie,
4013	* and the top 16 bits are unused.
4014	*
4015	* On failure, the returned value is one of the following:
4016	*
4017	* -EINVAL SYN cookie cannot be issued due to error
4018	*
4019	* -ENOENT SYN cookie should not be issued (no SYN flood)
4020	*
4021	* -EOPNOTSUPP kernel configuration does not enable SYN cookies
4022	*
4023	* -EPROTONOSUPPORT IP packet version is not 4 or 6
4024	*
4025	* long bpf_skb_output(void ctx, struct bpf_map map, u64 flags, void *data, u64 size)
4026	* Description
4027	* Write raw data blob into a special BPF perf event held by
4028	* map of type BPF_MAP_TYPE_PERF_EVENT_ARRAY. This perf
4029	* event must have the following attributes: PERF_SAMPLE_RAW
4030	* as sample_type, PERF_TYPE_SOFTWARE as type, and
4031	* PERF_COUNT_SW_BPF_OUTPUT as config.
4032	*
4033	* The flags are used to indicate the index in map for which
4034	* the value must be put, masked with BPF_F_INDEX_MASK.
4035	* Alternatively, flags can be set to BPF_F_CURRENT_CPU
4036	* to indicate that the index of the current CPU core should be
4037	* used.
4038	*
4039	* The value to write, of size, is passed through eBPF stack and
4040	* pointed by data.
4041	*
4042	* ctx is a pointer to in-kernel struct sk_buff.
4043	*
4044	* This helper is similar to bpf_perf_event_output\ () but
4045	* restricted to raw_tracepoint bpf programs.
4046	* Return
4047	* 0 on success, or a negative error in case of failure.
4048	*
4049	* long bpf_probe_read_user(void dst, u32 size, const void unsafe_ptr)
4050	* Description
4051	* Safely attempt to read size bytes from user space address
4052	* unsafe_ptr and store the data in dst.
4053	* Return
4054	* 0 on success, or a negative error in case of failure.
4055	*
4056	* long bpf_probe_read_kernel(void dst, u32 size, const void unsafe_ptr)
4057	* Description
4058	* Safely attempt to read size bytes from kernel space address
4059	* unsafe_ptr and store the data in dst.
4060	* Return
4061	* 0 on success, or a negative error in case of failure.
4062	*
4063	* long bpf_probe_read_user_str(void dst, u32 size, const void unsafe_ptr)
4064	* Description
4065	* Copy a NUL terminated string from an unsafe user address
4066	* unsafe_ptr to dst. The size should include the
4067	* terminating NUL byte. In case the string length is smaller than
4068	* size, the target is not padded with further NUL bytes. If the
4069	* string length is larger than size, just size-1 bytes are
4070	* copied and the last byte is set to NUL.
4071	*
4072	* On success, returns the number of bytes that were written,
4073	* including the terminal NUL. This makes this helper useful in
4074	* tracing programs for reading strings, and more importantly to
4075	* get its length at runtime. See the following snippet:
4076	*
4077	* ::
4078	*
4079	* SEC("kprobe/sys_open")
4080	* void bpf_sys_open(struct pt_regs *ctx)
4081	* {
4082	* char buf[PATHLEN]; // PATHLEN is defined to 256
4083	* int res = bpf_probe_read_user_str(buf, sizeof(buf),
4084	* ctx->di);
4085	*
4086	* // Consume buf, for example push it to
4087	* // userspace via bpf_perf_event_output(); we
4088	* // can use res (the string length) as event
4089	* // size, after checking its boundaries.
4090	* }
4091	*
4092	* In comparison, using bpf_probe_read_user\ () helper here
4093	* instead to read the string would require to estimate the length
4094	* at compile time, and would often result in copying more memory
4095	* than necessary.
4096	*
4097	* Another useful use case is when parsing individual process
4098	* arguments or individual environment variables navigating
4099	* current\ ->mm->arg_start and current\
4100	* ->mm->env_start: using this helper and the return value,
4101	* one can quickly iterate at the right offset of the memory area.
4102	* Return
4103	* On success, the strictly positive length of the output string,
4104	* including the trailing NUL character. On error, a negative
4105	* value.
4106	*
4107	* long bpf_probe_read_kernel_str(void dst, u32 size, const void unsafe_ptr)
4108	* Description
4109	* Copy a NUL terminated string from an unsafe kernel address unsafe_ptr
4110	* to dst. Same semantics as with bpf_probe_read_user_str\ () apply.
4111	* Return
4112	* On success, the strictly positive length of the string, including
4113	* the trailing NUL character. On error, a negative value.
4114	*
4115	* long bpf_tcp_send_ack(void *tp, u32 rcv_nxt)
4116	* Description
4117	* Send out a tcp-ack. tp is the in-kernel struct tcp_sock.
4118	* rcv_nxt is the ack_seq to be sent out.
4119	* Return
4120	* 0 on success, or a negative error in case of failure.
4121	*
4122	* long bpf_send_signal_thread(u32 sig)
4123	* Description
4124	* Send signal sig to the thread corresponding to the current task.
4125	* Return
4126	* 0 on success or successfully queued.
4127	*
4128	* -EBUSY if work queue under nmi is full.
4129	*
4130	* -EINVAL if sig is invalid.
4131	*
4132	* -EPERM if no permission to send the sig.
4133	*
4134	* -EAGAIN if bpf program can try again.
4135	*
4136	* u64 bpf_jiffies64(void)
4137	* Description
4138	* Obtain the 64bit jiffies
4139	* Return
4140	* The 64 bit jiffies
4141	*
4142	* long bpf_read_branch_records(struct bpf_perf_event_data ctx, void buf, u32 size, u64 flags)
4143	* Description
4144	* For an eBPF program attached to a perf event, retrieve the
4145	* branch records (struct perf_branch_entry) associated to ctx
4146	* and store it in the buffer pointed by buf up to size
4147	* size bytes.
4148	* Return
4149	* On success, number of bytes written to buf. On error, a
4150	* negative value.
4151	*
4152	* The flags can be set to BPF_F_GET_BRANCH_RECORDS_SIZE to
4153	* instead return the number of bytes required to store all the
4154	* branch entries. If this flag is set, buf may be NULL.
4155	*
4156	* -EINVAL if arguments invalid or size not a multiple
4157	* of sizeof\ (struct perf_branch_entry\ ).
4158	*
4159	* -ENOENT if architecture does not support branch records.
4160	*
4161	* long bpf_get_ns_current_pid_tgid(u64 dev, u64 ino, struct bpf_pidns_info *nsdata, u32 size)
4162	* Description
4163	* Returns 0 on success, values for pid and tgid as seen from the current
4164	* namespace will be returned in nsdata.
4165	* Return
4166	* 0 on success, or one of the following in case of failure:
4167	*
4168	* -EINVAL if dev and inum supplied don't match dev_t and inode number
4169	* with nsfs of current task, or if dev conversion to dev_t lost high bits.
4170	*
4171	* -ENOENT if pidns does not exists for the current task.
4172	*
4173	* long bpf_xdp_output(void ctx, struct bpf_map map, u64 flags, void *data, u64 size)
4174	* Description
4175	* Write raw data blob into a special BPF perf event held by
4176	* map of type BPF_MAP_TYPE_PERF_EVENT_ARRAY. This perf
4177	* event must have the following attributes: PERF_SAMPLE_RAW
4178	* as sample_type, PERF_TYPE_SOFTWARE as type, and
4179	* PERF_COUNT_SW_BPF_OUTPUT as config.
4180	*
4181	* The flags are used to indicate the index in map for which
4182	* the value must be put, masked with BPF_F_INDEX_MASK.
4183	* Alternatively, flags can be set to BPF_F_CURRENT_CPU
4184	* to indicate that the index of the current CPU core should be
4185	* used.
4186	*
4187	* The value to write, of size, is passed through eBPF stack and
4188	* pointed by data.
4189	*
4190	* ctx is a pointer to in-kernel struct xdp_buff.
4191	*
4192	* This helper is similar to bpf_perf_eventoutput\ () but
4193	* restricted to raw_tracepoint bpf programs.
4194	* Return
4195	* 0 on success, or a negative error in case of failure.
4196	*
4197	* u64 bpf_get_netns_cookie(void *ctx)
4198	* Description
4199	* Retrieve the cookie (generated by the kernel) of the network
4200	* namespace the input ctx is associated with. The network
4201	* namespace cookie remains stable for its lifetime and provides
4202	* a global identifier that can be assumed unique. If ctx is
4203	* NULL, then the helper returns the cookie for the initial
4204	* network namespace. The cookie itself is very similar to that
4205	* of bpf_get_socket_cookie\ () helper, but for network
4206	* namespaces instead of sockets.
4207	* Return
4208	* A 8-byte long opaque number.
4209	*
4210	* u64 bpf_get_current_ancestor_cgroup_id(int ancestor_level)
4211	* Description
4212	* Return id of cgroup v2 that is ancestor of the cgroup associated
4213	* with the current task at the ancestor_level. The root cgroup
4214	* is at ancestor_level zero and each step down the hierarchy
4215	* increments the level. If ancestor_level == level of cgroup
4216	* associated with the current task, then return value will be the
4217	* same as that of bpf_get_current_cgroup_id\ ().
4218	*
4219	* The helper is useful to implement policies based on cgroups
4220	* that are upper in hierarchy than immediate cgroup associated
4221	* with the current task.
4222	*
4223	* The format of returned id and helper limitations are same as in
4224	* bpf_get_current_cgroup_id\ ().
4225	* Return
4226	* The id is returned or 0 in case the id could not be retrieved.
4227	*
4228	* long bpf_sk_assign(struct sk_buff skb, void sk, u64 flags)
4229	* Description
4230	* Helper is overloaded depending on BPF program type. This
4231	* description applies to BPF_PROG_TYPE_SCHED_CLS and
4232	* BPF_PROG_TYPE_SCHED_ACT programs.
4233	*
4234	* Assign the sk to the skb. When combined with appropriate
4235	* routing configuration to receive the packet towards the socket,
4236	* will cause skb to be delivered to the specified socket.
4237	* Subsequent redirection of skb via bpf_redirect\ (),
4238	* bpf_clone_redirect\ () or other methods outside of BPF may
4239	* interfere with successful delivery to the socket.
4240	*
4241	* This operation is only valid from TC ingress path.
4242	*
4243	* The flags argument must be zero.
4244	* Return
4245	* 0 on success, or a negative error in case of failure:
4246	*
4247	* -EINVAL if specified flags are not supported.
4248	*
4249	* -ENOENT if the socket is unavailable for assignment.
4250	*
4251	* -ENETUNREACH if the socket is unreachable (wrong netns).
4252	*
4253	* -EOPNOTSUPP if the operation is not supported, for example
4254	* a call from outside of TC ingress.
4255	*
4256	* long bpf_sk_assign(struct bpf_sk_lookup ctx, struct bpf_sock sk, u64 flags)
4257	* Description
4258	* Helper is overloaded depending on BPF program type. This
4259	* description applies to BPF_PROG_TYPE_SK_LOOKUP programs.
4260	*
4261	* Select the sk as a result of a socket lookup.
4262	*
4263	* For the operation to succeed passed socket must be compatible
4264	* with the packet description provided by the ctx object.
4265	*
4266	* L4 protocol (IPPROTO_TCP or IPPROTO_UDP) must
4267	* be an exact match. While IP family (AF_INET or
4268	* AF_INET6) must be compatible, that is IPv6 sockets
4269	* that are not v6-only can be selected for IPv4 packets.
4270	*
4271	* Only TCP listeners and UDP unconnected sockets can be
4272	* selected. sk can also be NULL to reset any previous
4273	* selection.
4274	*
4275	* flags argument can combination of following values:
4276	*
4277	* * BPF_SK_LOOKUP_F_REPLACE to override the previous
4278	* socket selection, potentially done by a BPF program
4279	* that ran before us.
4280	*
4281	* * BPF_SK_LOOKUP_F_NO_REUSEPORT to skip
4282	* load-balancing within reuseport group for the socket
4283	* being selected.
4284	*
4285	* On success ctx->sk will point to the selected socket.
4286	*
4287	* Return
4288	* 0 on success, or a negative errno in case of failure.
4289	*
4290	* * -EAFNOSUPPORT if socket family (sk->family) is
4291	* not compatible with packet family (ctx->family).
4292	*
4293	* * -EEXIST if socket has been already selected,
4294	* potentially by another program, and
4295	* BPF_SK_LOOKUP_F_REPLACE flag was not specified.
4296	*
4297	* * -EINVAL if unsupported flags were specified.
4298	*
4299	* * -EPROTOTYPE if socket L4 protocol
4300	* (sk->protocol) doesn't match packet protocol
4301	* (ctx->protocol).
4302	*
4303	* * -ESOCKTNOSUPPORT if socket is not in allowed
4304	* state (TCP listening or UDP unconnected).
4305	*
4306	* u64 bpf_ktime_get_boot_ns(void)
4307	* Description
4308	* Return the time elapsed since system boot, in nanoseconds.
4309	* Does include the time the system was suspended.
4310	* See: clock_gettime\ (CLOCK_BOOTTIME)
4311	* Return
4312	* Current ktime.
4313	*
4314	* long bpf_seq_printf(struct seq_file m, const char fmt, u32 fmt_size, const void *data, u32 data_len)
4315	* Description
4316	* bpf_seq_printf\ () uses seq_file seq_printf\ () to print
4317	* out the format string.
4318	* The m represents the seq_file. The fmt and fmt_size are for
4319	* the format string itself. The data and data_len are format string
4320	* arguments. The data are a u64 array and corresponding format string
4321	* values are stored in the array. For strings and pointers where pointees
4322	* are accessed, only the pointer values are stored in the data array.
4323	* The data_len is the size of data in bytes - must be a multiple of 8.
4324	*
4325	* Formats %s, %p{i,I}{4,6} requires to read kernel memory.
4326	* Reading kernel memory may fail due to either invalid address or
4327	* valid address but requiring a major memory fault. If reading kernel memory
4328	* fails, the string for %s will be an empty string, and the ip
4329	* address for %p{i,I}{4,6} will be 0. Not returning error to
4330	* bpf program is consistent with what bpf_trace_printk\ () does for now.
4331	* Return
4332	* 0 on success, or a negative error in case of failure:
4333	*
4334	* -EBUSY if per-CPU memory copy buffer is busy, can try again
4335	* by returning 1 from bpf program.
4336	*
4337	* -EINVAL if arguments are invalid, or if fmt is invalid/unsupported.
4338	*
4339	* -E2BIG if fmt contains too many format specifiers.
4340	*
4341	* -EOVERFLOW if an overflow happened: The same object will be tried again.
4342	*
4343	* long bpf_seq_write(struct seq_file m, const void data, u32 len)
4344	* Description
4345	* bpf_seq_write\ () uses seq_file seq_write\ () to write the data.
4346	* The m represents the seq_file. The data and len represent the
4347	* data to write in bytes.
4348	* Return
4349	* 0 on success, or a negative error in case of failure:
4350	*
4351	* -EOVERFLOW if an overflow happened: The same object will be tried again.
4352	*
4353	* u64 bpf_sk_cgroup_id(void *sk)
4354	* Description
4355	* Return the cgroup v2 id of the socket sk.
4356	*
4357	* sk must be a non-NULL pointer to a socket, e.g. one
4358	* returned from bpf_sk_lookup_xxx\ (),
4359	* bpf_sk_fullsock\ (), etc. The format of returned id is
4360	* same as in bpf_skb_cgroup_id\ ().
4361	*
4362	* This helper is available only if the kernel was compiled with
4363	* the CONFIG_SOCK_CGROUP_DATA configuration option.
4364	* Return
4365	* The id is returned or 0 in case the id could not be retrieved.
4366	*
4367	* u64 bpf_sk_ancestor_cgroup_id(void *sk, int ancestor_level)
4368	* Description
4369	* Return id of cgroup v2 that is ancestor of cgroup associated
4370	* with the sk at the ancestor_level. The root cgroup is at
4371	* ancestor_level zero and each step down the hierarchy
4372	* increments the level. If ancestor_level == level of cgroup
4373	* associated with sk, then return value will be same as that
4374	* of bpf_sk_cgroup_id\ ().
4375	*
4376	* The helper is useful to implement policies based on cgroups
4377	* that are upper in hierarchy than immediate cgroup associated
4378	* with sk.
4379	*
4380	* The format of returned id and helper limitations are same as in
4381	* bpf_sk_cgroup_id\ ().
4382	* Return
4383	* The id is returned or 0 in case the id could not be retrieved.
4384	*
4385	* long bpf_ringbuf_output(void ringbuf, void data, u64 size, u64 flags)
4386	* Description
4387	* Copy size bytes from data into a ring buffer ringbuf.
4388	* If BPF_RB_NO_WAKEUP is specified in flags, no notification
4389	* of new data availability is sent.
4390	* If BPF_RB_FORCE_WAKEUP is specified in flags, notification
4391	* of new data availability is sent unconditionally.
4392	* If 0 is specified in flags, an adaptive notification
4393	* of new data availability is sent.
4394	*
4395	* An adaptive notification is a notification sent whenever the user-space
4396	* process has caught up and consumed all available payloads. In case the user-space
4397	* process is still processing a previous payload, then no notification is needed
4398	* as it will process the newly added payload automatically.
4399	* Return
4400	* 0 on success, or a negative error in case of failure.
4401	*
4402	* void bpf_ringbuf_reserve(void ringbuf, u64 size, u64 flags)
4403	* Description
4404	* Reserve size bytes of payload in a ring buffer ringbuf.
4405	* flags must be 0.
4406	* Return
4407	* Valid pointer with size bytes of memory available; NULL,
4408	* otherwise.
4409	*
4410	* void bpf_ringbuf_submit(void *data, u64 flags)
4411	* Description
4412	* Submit reserved ring buffer sample, pointed to by data.
4413	* If BPF_RB_NO_WAKEUP is specified in flags, no notification
4414	* of new data availability is sent.
4415	* If BPF_RB_FORCE_WAKEUP is specified in flags, notification
4416	* of new data availability is sent unconditionally.
4417	* If 0 is specified in flags, an adaptive notification
4418	* of new data availability is sent.
4419	*
4420	* See 'bpf_ringbuf_output()' for the definition of adaptive notification.
4421	* Return
4422	* Nothing. Always succeeds.
4423	*
4424	* void bpf_ringbuf_discard(void *data, u64 flags)
4425	* Description
4426	* Discard reserved ring buffer sample, pointed to by data.
4427	* If BPF_RB_NO_WAKEUP is specified in flags, no notification
4428	* of new data availability is sent.
4429	* If BPF_RB_FORCE_WAKEUP is specified in flags, notification
4430	* of new data availability is sent unconditionally.
4431	* If 0 is specified in flags, an adaptive notification
4432	* of new data availability is sent.
4433	*
4434	* See 'bpf_ringbuf_output()' for the definition of adaptive notification.
4435	* Return
4436	* Nothing. Always succeeds.
4437	*
4438	* u64 bpf_ringbuf_query(void *ringbuf, u64 flags)
4439	* Description
4440	* Query various characteristics of provided ring buffer. What
4441	* exactly is queries is determined by flags:
4442	*
4443	* * BPF_RB_AVAIL_DATA: Amount of data not yet consumed.
4444	* * BPF_RB_RING_SIZE: The size of ring buffer.
4445	* * BPF_RB_CONS_POS: Consumer position (can wrap around).
4446	* * BPF_RB_PROD_POS: Producer(s) position (can wrap around).
4447	*
4448	* Data returned is just a momentary snapshot of actual values
4449	* and could be inaccurate, so this facility should be used to
4450	* power heuristics and for reporting, not to make 100% correct
4451	* calculation.
4452	* Return
4453	* Requested value, or 0, if flags are not recognized.
4454	*
4455	* long bpf_csum_level(struct sk_buff *skb, u64 level)
4456	* Description
4457	* Change the skbs checksum level by one layer up or down, or
4458	* reset it entirely to none in order to have the stack perform
4459	* checksum validation. The level is applicable to the following
4460	* protocols: TCP, UDP, GRE, SCTP, FCOE. For example, a decap of
4461	* \| ETH \| IP \| UDP \| GUE \| IP \| TCP \| into \| ETH \| IP \| TCP \|
4462	* through bpf_skb_adjust_room\ () helper with passing in
4463	* BPF_F_ADJ_ROOM_NO_CSUM_RESET flag would require one call
4464	* to bpf_csum_level\ () with BPF_CSUM_LEVEL_DEC since
4465	* the UDP header is removed. Similarly, an encap of the latter
4466	* into the former could be accompanied by a helper call to
4467	* bpf_csum_level\ () with BPF_CSUM_LEVEL_INC if the
4468	* skb is still intended to be processed in higher layers of the
4469	* stack instead of just egressing at tc.
4470	*
4471	* There are three supported level settings at this time:
4472	*
4473	* * BPF_CSUM_LEVEL_INC: Increases skb->csum_level for skbs
4474	* with CHECKSUM_UNNECESSARY.
4475	* * BPF_CSUM_LEVEL_DEC: Decreases skb->csum_level for skbs
4476	* with CHECKSUM_UNNECESSARY.
4477	* * BPF_CSUM_LEVEL_RESET: Resets skb->csum_level to 0 and
4478	* sets CHECKSUM_NONE to force checksum validation by the stack.
4479	* * BPF_CSUM_LEVEL_QUERY: No-op, returns the current
4480	* skb->csum_level.
4481	* Return
4482	* 0 on success, or a negative error in case of failure. In the
4483	* case of BPF_CSUM_LEVEL_QUERY, the current skb->csum_level
4484	* is returned or the error code -EACCES in case the skb is not
4485	* subject to CHECKSUM_UNNECESSARY.
4486	*
4487	* struct tcp6_sock bpf_skc_to_tcp6_sock(void sk)
4488	* Description
4489	* Dynamically cast a sk pointer to a tcp6_sock pointer.
4490	* Return
4491	* sk if casting is valid, or NULL otherwise.
4492	*
4493	* struct tcp_sock bpf_skc_to_tcp_sock(void sk)
4494	* Description
4495	* Dynamically cast a sk pointer to a tcp_sock pointer.
4496	* Return
4497	* sk if casting is valid, or NULL otherwise.
4498	*
4499	* struct tcp_timewait_sock bpf_skc_to_tcp_timewait_sock(void sk)
4500	* Description
4501	* Dynamically cast a sk pointer to a tcp_timewait_sock pointer.
4502	* Return
4503	* sk if casting is valid, or NULL otherwise.
4504	*
4505	* struct tcp_request_sock bpf_skc_to_tcp_request_sock(void sk)
4506	* Description
4507	* Dynamically cast a sk pointer to a tcp_request_sock pointer.
4508	* Return
4509	* sk if casting is valid, or NULL otherwise.
4510	*
4511	* struct udp6_sock bpf_skc_to_udp6_sock(void sk)
4512	* Description
4513	* Dynamically cast a sk pointer to a udp6_sock pointer.
4514	* Return
4515	* sk if casting is valid, or NULL otherwise.
4516	*
4517	* long bpf_get_task_stack(struct task_struct task, void buf, u32 size, u64 flags)
4518	* Description
4519	* Return a user or a kernel stack in bpf program provided buffer.
4520	* To achieve this, the helper needs task, which is a valid
4521	* pointer to struct task_struct. To store the stacktrace, the
4522	* bpf program provides buf with a nonnegative size.
4523	*
4524	* The last argument, flags, holds the number of stack frames to
4525	* skip (from 0 to 255), masked with
4526	* BPF_F_SKIP_FIELD_MASK. The next bits can be used to set
4527	* the following flags:
4528	*
4529	* BPF_F_USER_STACK
4530	* Collect a user space stack instead of a kernel stack.
4531	* BPF_F_USER_BUILD_ID
4532	* Collect buildid+offset instead of ips for user stack,
4533	* only valid if BPF_F_USER_STACK is also specified.
4534	*
4535	* bpf_get_task_stack\ () can collect up to
4536	* PERF_MAX_STACK_DEPTH both kernel and user frames, subject
4537	* to sufficient large buffer size. Note that
4538	* this limit can be controlled with the sysctl program, and
4539	* that it should be manually increased in order to profile long
4540	* user stacks (such as stacks for Java programs). To do so, use:
4541	*
4542	* ::
4543	*
4544	* # sysctl kernel.perf_event_max_stack=<new value>
4545	* Return
4546	* The non-negative copied buf length equal to or less than
4547	* size on success, or a negative error in case of failure.
4548	*
4549	* long bpf_load_hdr_opt(struct bpf_sock_ops skops, void searchby_res, u32 len, u64 flags)
4550	* Description
4551	* Load header option. Support reading a particular TCP header
4552	* option for bpf program (BPF_PROG_TYPE_SOCK_OPS).
4553	*
4554	* If flags is 0, it will search the option from the
4555	* skops\ ->skb_data. The comment in struct bpf_sock_ops
4556	* has details on what skb_data contains under different
4557	* skops\ ->op.
4558	*
4559	* The first byte of the searchby_res specifies the
4560	* kind that it wants to search.
4561	*
4562	* If the searching kind is an experimental kind
4563	* (i.e. 253 or 254 according to RFC6994). It also
4564	* needs to specify the "magic" which is either
4565	* 2 bytes or 4 bytes. It then also needs to
4566	* specify the size of the magic by using
4567	* the 2nd byte which is "kind-length" of a TCP
4568	* header option and the "kind-length" also
4569	* includes the first 2 bytes "kind" and "kind-length"
4570	* itself as a normal TCP header option also does.
4571	*
4572	* For example, to search experimental kind 254 with
4573	* 2 byte magic 0xeB9F, the searchby_res should be
4574	* [ 254, 4, 0xeB, 0x9F, 0, 0, .... 0 ].
4575	*
4576	* To search for the standard window scale option (3),
4577	* the searchby_res should be [ 3, 0, 0, .... 0 ].
4578	* Note, kind-length must be 0 for regular option.
4579	*
4580	* Searching for No-Op (0) and End-of-Option-List (1) are
4581	* not supported.
4582	*
4583	* len must be at least 2 bytes which is the minimal size
4584	* of a header option.
4585	*
4586	* Supported flags:
4587	*
4588	* * BPF_LOAD_HDR_OPT_TCP_SYN to search from the
4589	* saved_syn packet or the just-received syn packet.
4590	*
4591	* Return
4592	* > 0 when found, the header option is copied to searchby_res.
4593	* The return value is the total length copied. On failure, a
4594	* negative error code is returned:
4595	*
4596	* -EINVAL if a parameter is invalid.
4597	*
4598	* -ENOMSG if the option is not found.
4599	*
4600	* -ENOENT if no syn packet is available when
4601	* BPF_LOAD_HDR_OPT_TCP_SYN is used.
4602	*
4603	* -ENOSPC if there is not enough space. Only len number of
4604	* bytes are copied.
4605	*
4606	* -EFAULT on failure to parse the header options in the
4607	* packet.
4608	*
4609	* -EPERM if the helper cannot be used under the current
4610	* skops\ ->op.
4611	*
4612	* long bpf_store_hdr_opt(struct bpf_sock_ops skops, const void from, u32 len, u64 flags)
4613	* Description
4614	* Store header option. The data will be copied
4615	* from buffer from with length len to the TCP header.
4616	*
4617	* The buffer from should have the whole option that
4618	* includes the kind, kind-length, and the actual
4619	* option data. The len must be at least kind-length
4620	* long. The kind-length does not have to be 4 byte
4621	* aligned. The kernel will take care of the padding
4622	* and setting the 4 bytes aligned value to th->doff.
4623	*
4624	* This helper will check for duplicated option
4625	* by searching the same option in the outgoing skb.
4626	*
4627	* This helper can only be called during
4628	* BPF_SOCK_OPS_WRITE_HDR_OPT_CB.
4629	*
4630	* Return
4631	* 0 on success, or negative error in case of failure:
4632	*
4633	* -EINVAL If param is invalid.
4634	*
4635	* -ENOSPC if there is not enough space in the header.
4636	* Nothing has been written
4637	*
4638	* -EEXIST if the option already exists.
4639	*
4640	* -EFAULT on failure to parse the existing header options.
4641	*
4642	* -EPERM if the helper cannot be used under the current
4643	* skops\ ->op.
4644	*
4645	* long bpf_reserve_hdr_opt(struct bpf_sock_ops *skops, u32 len, u64 flags)
4646	* Description
4647	* Reserve len bytes for the bpf header option. The
4648	* space will be used by bpf_store_hdr_opt\ () later in
4649	* BPF_SOCK_OPS_WRITE_HDR_OPT_CB.
4650	*
4651	* If bpf_reserve_hdr_opt\ () is called multiple times,
4652	* the total number of bytes will be reserved.
4653	*
4654	* This helper can only be called during
4655	* BPF_SOCK_OPS_HDR_OPT_LEN_CB.
4656	*
4657	* Return
4658	* 0 on success, or negative error in case of failure:
4659	*
4660	* -EINVAL if a parameter is invalid.
4661	*
4662	* -ENOSPC if there is not enough space in the header.
4663	*
4664	* -EPERM if the helper cannot be used under the current
4665	* skops\ ->op.
4666	*
4667	* void bpf_inode_storage_get(struct bpf_map map, void inode, void value, u64 flags)
4668	* Description
4669	* Get a bpf_local_storage from an inode.
4670	*
4671	* Logically, it could be thought of as getting the value from
4672	* a map with inode as the key. From this
4673	* perspective, the usage is not much different from
4674	* bpf_map_lookup_elem\ (map, &\ inode) except this
4675	* helper enforces the key must be an inode and the map must also
4676	* be a BPF_MAP_TYPE_INODE_STORAGE.
4677	*
4678	* Underneath, the value is stored locally at inode instead of
4679	* the map. The map is used as the bpf-local-storage
4680	* "type". The bpf-local-storage "type" (i.e. the map) is
4681	* searched against all bpf_local_storage residing at inode.
4682	*
4683	* An optional flags (BPF_LOCAL_STORAGE_GET_F_CREATE) can be
4684	* used such that a new bpf_local_storage will be
4685	* created if one does not exist. value can be used
4686	* together with BPF_LOCAL_STORAGE_GET_F_CREATE to specify
4687	* the initial value of a bpf_local_storage. If value is
4688	* NULL, the new bpf_local_storage will be zero initialized.
4689	* Return
4690	* A bpf_local_storage pointer is returned on success.
4691	*
4692	* NULL if not found or there was an error in adding
4693	* a new bpf_local_storage.
4694	*
4695	* int bpf_inode_storage_delete(struct bpf_map map, void inode)
4696	* Description
4697	* Delete a bpf_local_storage from an inode.
4698	* Return
4699	* 0 on success.
4700	*
4701	* -ENOENT if the bpf_local_storage cannot be found.
4702	*
4703	* long bpf_d_path(struct path path, char buf, u32 sz)
4704	* Description
4705	* Return full path for given struct path object, which
4706	* needs to be the kernel BTF path object. The path is
4707	* returned in the provided buffer buf of size sz and
4708	* is zero terminated.
4709	*
4710	* Return
4711	* On success, the strictly positive length of the string,
4712	* including the trailing NUL character. On error, a negative
4713	* value.
4714	*
4715	* long bpf_copy_from_user(void dst, u32 size, const void user_ptr)
4716	* Description
4717	* Read size bytes from user space address user_ptr and store
4718	* the data in dst. This is a wrapper of copy_from_user\ ().
4719	* Return
4720	* 0 on success, or a negative error in case of failure.
4721	*
4722	* long bpf_snprintf_btf(char str, u32 str_size, struct btf_ptr ptr, u32 btf_ptr_size, u64 flags)
4723	* Description
4724	* Use BTF to store a string representation of ptr->ptr in str,
4725	* using ptr->type_id. This value should specify the type
4726	* that ptr->ptr points to. LLVM __builtin_btf_type_id(type, 1)
4727	* can be used to look up vmlinux BTF type ids. Traversing the
4728	* data structure using BTF, the type information and values are
4729	* stored in the first str_size - 1 bytes of str. Safe copy of
4730	* the pointer data is carried out to avoid kernel crashes during
4731	* operation. Smaller types can use string space on the stack;
4732	* larger programs can use map data to store the string
4733	* representation.
4734	*
4735	* The string can be subsequently shared with userspace via
4736	* bpf_perf_event_output() or ring buffer interfaces.
4737	* bpf_trace_printk() is to be avoided as it places too small
4738	* a limit on string size to be useful.
4739	*
4740	* flags is a combination of
4741	*
4742	* BTF_F_COMPACT
4743	* no formatting around type information
4744	* BTF_F_NONAME
4745	* no struct/union member names/types
4746	* BTF_F_PTR_RAW
4747	* show raw (unobfuscated) pointer values;
4748	* equivalent to printk specifier %px.
4749	* BTF_F_ZERO
4750	* show zero-valued struct/union members; they
4751	* are not displayed by default
4752	*
4753	* Return
4754	* The number of bytes that were written (or would have been
4755	* written if output had to be truncated due to string size),
4756	* or a negative error in cases of failure.
4757	*
4758	* long bpf_seq_printf_btf(struct seq_file m, struct btf_ptr ptr, u32 ptr_size, u64 flags)
4759	* Description
4760	* Use BTF to write to seq_write a string representation of
4761	* ptr->ptr, using ptr->type_id as per bpf_snprintf_btf().
4762	* flags are identical to those used for bpf_snprintf_btf.
4763	* Return
4764	* 0 on success or a negative error in case of failure.
4765	*
4766	* u64 bpf_skb_cgroup_classid(struct sk_buff *skb)
4767	* Description
4768	* See bpf_get_cgroup_classid\ () for the main description.
4769	* This helper differs from bpf_get_cgroup_classid\ () in that
4770	* the cgroup v1 net_cls class is retrieved only from the skb's
4771	* associated socket instead of the current process.
4772	* Return
4773	* The id is returned or 0 in case the id could not be retrieved.
4774	*
4775	* long bpf_redirect_neigh(u32 ifindex, struct bpf_redir_neigh *params, int plen, u64 flags)
4776	* Description
4777	* Redirect the packet to another net device of index ifindex
4778	* and fill in L2 addresses from neighboring subsystem. This helper
4779	* is somewhat similar to bpf_redirect\ (), except that it
4780	* populates L2 addresses as well, meaning, internally, the helper
4781	* relies on the neighbor lookup for the L2 address of the nexthop.
4782	*
4783	* The helper will perform a FIB lookup based on the skb's
4784	* networking header to get the address of the next hop, unless
4785	* this is supplied by the caller in the params argument. The
4786	* plen argument indicates the len of params and should be set
4787	* to 0 if params is NULL.
4788	*
4789	* The flags argument is reserved and must be 0. The helper is
4790	* currently only supported for tc BPF program types, and enabled
4791	* for IPv4 and IPv6 protocols.
4792	* Return
4793	* The helper returns TC_ACT_REDIRECT on success or
4794	* TC_ACT_SHOT on error.
4795	*
4796	* void bpf_per_cpu_ptr(const void percpu_ptr, u32 cpu)
4797	* Description
4798	* Take a pointer to a percpu ksym, percpu_ptr, and return a
4799	* pointer to the percpu kernel variable on cpu. A ksym is an
4800	* extern variable decorated with '__ksym'. For ksym, there is a
4801	* global var (either static or global) defined of the same name
4802	* in the kernel. The ksym is percpu if the global var is percpu.
4803	* The returned pointer points to the global percpu var on cpu.
4804	*
4805	* bpf_per_cpu_ptr() has the same semantic as per_cpu_ptr() in the
4806	* kernel, except that bpf_per_cpu_ptr() may return NULL. This
4807	* happens if cpu is larger than nr_cpu_ids. The caller of
4808	* bpf_per_cpu_ptr() must check the returned value.
4809	* Return
4810	* A pointer pointing to the kernel percpu variable on cpu, or
4811	* NULL, if cpu is invalid.
4812	*
4813	* void bpf_this_cpu_ptr(const void percpu_ptr)
4814	* Description
4815	* Take a pointer to a percpu ksym, percpu_ptr, and return a
4816	* pointer to the percpu kernel variable on this cpu. See the
4817	* description of 'ksym' in bpf_per_cpu_ptr\ ().
4818	*
4819	* bpf_this_cpu_ptr() has the same semantic as this_cpu_ptr() in
4820	* the kernel. Different from bpf_per_cpu_ptr\ (), it would
4821	* never return NULL.
4822	* Return
4823	* A pointer pointing to the kernel percpu variable on this cpu.
4824	*
4825	* long bpf_redirect_peer(u32 ifindex, u64 flags)
4826	* Description
4827	* Redirect the packet to another net device of index ifindex.
4828	* This helper is somewhat similar to bpf_redirect\ (), except
4829	* that the redirection happens to the ifindex' peer device and
4830	* the netns switch takes place from ingress to ingress without
4831	* going through the CPU's backlog queue.
4832	*
4833	* The flags argument is reserved and must be 0. The helper is
4834	* currently only supported for tc BPF program types at the ingress
4835	* hook and for veth device types. The peer device must reside in a
4836	* different network namespace.
4837	* Return
4838	* The helper returns TC_ACT_REDIRECT on success or
4839	* TC_ACT_SHOT on error.
4840	*
4841	* void bpf_task_storage_get(struct bpf_map map, struct task_struct task, void value, u64 flags)
4842	* Description
4843	* Get a bpf_local_storage from the task.
4844	*
4845	* Logically, it could be thought of as getting the value from
4846	* a map with task as the key. From this
4847	* perspective, the usage is not much different from
4848	* bpf_map_lookup_elem\ (map, &\ task) except this
4849	* helper enforces the key must be a task_struct and the map must also
4850	* be a BPF_MAP_TYPE_TASK_STORAGE.
4851	*
4852	* Underneath, the value is stored locally at task instead of
4853	* the map. The map is used as the bpf-local-storage
4854	* "type". The bpf-local-storage "type" (i.e. the map) is
4855	* searched against all bpf_local_storage residing at task.
4856	*
4857	* An optional flags (BPF_LOCAL_STORAGE_GET_F_CREATE) can be
4858	* used such that a new bpf_local_storage will be
4859	* created if one does not exist. value can be used
4860	* together with BPF_LOCAL_STORAGE_GET_F_CREATE to specify
4861	* the initial value of a bpf_local_storage. If value is
4862	* NULL, the new bpf_local_storage will be zero initialized.
4863	* Return
4864	* A bpf_local_storage pointer is returned on success.
4865	*
4866	* NULL if not found or there was an error in adding
4867	* a new bpf_local_storage.
4868	*
4869	* long bpf_task_storage_delete(struct bpf_map map, struct task_struct task)
4870	* Description
4871	* Delete a bpf_local_storage from a task.
4872	* Return
4873	* 0 on success.
4874	*
4875	* -ENOENT if the bpf_local_storage cannot be found.
4876	*
4877	* struct task_struct *bpf_get_current_task_btf(void)
4878	* Description
4879	* Return a BTF pointer to the "current" task.
4880	* This pointer can also be used in helpers that accept an
4881	* ARG_PTR_TO_BTF_ID of type task_struct.
4882	* Return
4883	* Pointer to the current task.
4884	*
4885	* long bpf_bprm_opts_set(struct linux_binprm *bprm, u64 flags)
4886	* Description
4887	* Set or clear certain options on bprm:
4888	*
4889	* BPF_F_BPRM_SECUREEXEC Set the secureexec bit
4890	* which sets the AT_SECURE auxv for glibc. The bit
4891	* is cleared if the flag is not specified.
4892	* Return
4893	* -EINVAL if invalid flags are passed, zero otherwise.
4894	*
4895	* u64 bpf_ktime_get_coarse_ns(void)
4896	* Description
4897	* Return a coarse-grained version of the time elapsed since
4898	* system boot, in nanoseconds. Does not include time the system
4899	* was suspended.
4900	*
4901	* See: clock_gettime\ (CLOCK_MONOTONIC_COARSE)
4902	* Return
4903	* Current ktime.
4904	*
4905	* long bpf_ima_inode_hash(struct inode inode, void dst, u32 size)
4906	* Description
4907	* Returns the stored IMA hash of the inode (if it's available).
4908	* If the hash is larger than size, then only size
4909	* bytes will be copied to dst
4910	* Return
4911	* The hash_algo is returned on success,
4912	* -EOPNOTSUP if IMA is disabled or -EINVAL if
4913	* invalid arguments are passed.
4914	*
4915	* struct socket bpf_sock_from_file(struct file file)
4916	* Description
4917	* If the given file represents a socket, returns the associated
4918	* socket.
4919	* Return
4920	* A pointer to a struct socket on success or NULL if the file is
4921	* not a socket.
4922	*
4923	* long bpf_check_mtu(void ctx, u32 ifindex, u32 mtu_len, s32 len_diff, u64 flags)
4924	* Description
4925	* Check packet size against exceeding MTU of net device (based
4926	* on ifindex). This helper will likely be used in combination
4927	* with helpers that adjust/change the packet size.
4928	*
4929	* The argument len_diff can be used for querying with a planned
4930	* size change. This allows to check MTU prior to changing packet
4931	* ctx. Providing a len_diff adjustment that is larger than the
4932	* actual packet size (resulting in negative packet size) will in
4933	* principle not exceed the MTU, which is why it is not considered
4934	* a failure. Other BPF helpers are needed for performing the
4935	* planned size change; therefore the responsibility for catching
4936	* a negative packet size belongs in those helpers.
4937	*
4938	* Specifying ifindex zero means the MTU check is performed
4939	* against the current net device. This is practical if this isn't
4940	* used prior to redirect.
4941	*
4942	* On input mtu_len must be a valid pointer, else verifier will
4943	* reject BPF program. If the value mtu_len is initialized to
4944	* zero then the ctx packet size is use. When value mtu_len is
4945	* provided as input this specify the L3 length that the MTU check
4946	* is done against. Remember XDP and TC length operate at L2, but
4947	* this value is L3 as this correlate to MTU and IP-header tot_len
4948	* values which are L3 (similar behavior as bpf_fib_lookup).
4949	*
4950	* The Linux kernel route table can configure MTUs on a more
4951	* specific per route level, which is not provided by this helper.
4952	* For route level MTU checks use the bpf_fib_lookup\ ()
4953	* helper.
4954	*
4955	* ctx is either struct xdp_md for XDP programs or
4956	* struct sk_buff for tc cls_act programs.
4957	*
4958	* The flags argument can be a combination of one or more of the
4959	* following values:
4960	*
4961	* BPF_MTU_CHK_SEGS
4962	* This flag will only works for ctx struct sk_buff.
4963	* If packet context contains extra packet segment buffers
4964	* (often knows as GSO skb), then MTU check is harder to
4965	* check at this point, because in transmit path it is
4966	* possible for the skb packet to get re-segmented
4967	* (depending on net device features). This could still be
4968	* a MTU violation, so this flag enables performing MTU
4969	* check against segments, with a different violation
4970	* return code to tell it apart. Check cannot use len_diff.
4971	*
4972	* On return mtu_len pointer contains the MTU value of the net
4973	* device. Remember the net device configured MTU is the L3 size,
4974	* which is returned here and XDP and TC length operate at L2.
4975	* Helper take this into account for you, but remember when using
4976	* MTU value in your BPF-code.
4977	*
4978	* Return
4979	* * 0 on success, and populate MTU value in mtu_len pointer.
4980	*
4981	* * < 0 if any input argument is invalid (mtu_len not updated)
4982	*
4983	* MTU violations return positive values, but also populate MTU
4984	* value in mtu_len pointer, as this can be needed for
4985	* implementing PMTU handing:
4986	*
4987	* * BPF_MTU_CHK_RET_FRAG_NEEDED
4988	* * BPF_MTU_CHK_RET_SEGS_TOOBIG
4989	*
4990	* long bpf_for_each_map_elem(struct bpf_map map, void callback_fn, void *callback_ctx, u64 flags)
4991	* Description
4992	* For each element in map, call callback_fn function with
4993	* map, callback_ctx and other map-specific parameters.
4994	* The callback_fn should be a static function and
4995	* the callback_ctx should be a pointer to the stack.
4996	* The flags is used to control certain aspects of the helper.
4997	* Currently, the flags must be 0.
4998	*
4999	* The following are a list of supported map types and their
5000	* respective expected callback signatures:
5001	*
5002	* BPF_MAP_TYPE_HASH, BPF_MAP_TYPE_PERCPU_HASH,
5003	* BPF_MAP_TYPE_LRU_HASH, BPF_MAP_TYPE_LRU_PERCPU_HASH,
5004	* BPF_MAP_TYPE_ARRAY, BPF_MAP_TYPE_PERCPU_ARRAY
5005	*
5006	* long (\callback_fn)(struct bpf_map \map, const void \key, void \value, void \*ctx);
5007	*
5008	* For per_cpu maps, the map_value is the value on the cpu where the
5009	* bpf_prog is running.
5010	*
5011	* If callback_fn return 0, the helper will continue to the next
5012	* element. If return value is 1, the helper will skip the rest of
5013	* elements and return. Other return values are not used now.
5014	*
5015	* Return
5016	* The number of traversed map elements for success, -EINVAL for
5017	* invalid flags.
5018	*
5019	* long bpf_snprintf(char str, u32 str_size, const char fmt, u64 *data, u32 data_len)
5020	* Description
5021	* Outputs a string into the str buffer of size str_size
5022	* based on a format string stored in a read-only map pointed by
5023	* fmt.
5024	*
5025	* Each format specifier in fmt corresponds to one u64 element
5026	* in the data array. For strings and pointers where pointees
5027	* are accessed, only the pointer values are stored in the data
5028	* array. The data_len is the size of data in bytes - must be
5029	* a multiple of 8.
5030	*
5031	* Formats %s and %p{i,I}{4,6} require to read kernel
5032	* memory. Reading kernel memory may fail due to either invalid
5033	* address or valid address but requiring a major memory fault. If
5034	* reading kernel memory fails, the string for %s will be an
5035	* empty string, and the ip address for %p{i,I}{4,6} will be 0.
5036	* Not returning error to bpf program is consistent with what
5037	* bpf_trace_printk\ () does for now.
5038	*
5039	* Return
5040	* The strictly positive length of the formatted string, including
5041	* the trailing zero character. If the return value is greater than
5042	* str_size, str contains a truncated string, guaranteed to
5043	* be zero-terminated except when str_size is 0.
5044	*
5045	* Or -EBUSY if the per-CPU memory copy buffer is busy.
5046	*
5047	* long bpf_sys_bpf(u32 cmd, void *attr, u32 attr_size)
5048	* Description
5049	* Execute bpf syscall with given arguments.
5050	* Return
5051	* A syscall result.
5052	*
5053	* long bpf_btf_find_by_name_kind(char *name, int name_sz, u32 kind, int flags)
5054	* Description
5055	* Find BTF type with given name and kind in vmlinux BTF or in module's BTFs.
5056	* Return
5057	* Returns btf_id and btf_obj_fd in lower and upper 32 bits.
5058	*
5059	* long bpf_sys_close(u32 fd)
5060	* Description
5061	* Execute close syscall for given FD.
5062	* Return
5063	* A syscall result.
5064	*
5065	* long bpf_timer_init(struct bpf_timer timer, struct bpf_map map, u64 flags)
5066	* Description
5067	* Initialize the timer.
5068	* First 4 bits of flags specify clockid.
5069	* Only CLOCK_MONOTONIC, CLOCK_REALTIME, CLOCK_BOOTTIME are allowed.
5070	* All other bits of flags are reserved.
5071	* The verifier will reject the program if timer is not from
5072	* the same map.
5073	* Return
5074	* 0 on success.
5075	* -EBUSY if timer is already initialized.
5076	* -EINVAL if invalid flags are passed.
5077	* -EPERM if timer is in a map that doesn't have any user references.
5078	* The user space should either hold a file descriptor to a map with timers
5079	* or pin such map in bpffs. When map is unpinned or file descriptor is
5080	* closed all timers in the map will be cancelled and freed.
5081	*
5082	* long bpf_timer_set_callback(struct bpf_timer timer, void callback_fn)
5083	* Description
5084	* Configure the timer to call callback_fn static function.
5085	* Return
5086	* 0 on success.
5087	* -EINVAL if timer was not initialized with bpf_timer_init() earlier.
5088	* -EPERM if timer is in a map that doesn't have any user references.
5089	* The user space should either hold a file descriptor to a map with timers
5090	* or pin such map in bpffs. When map is unpinned or file descriptor is
5091	* closed all timers in the map will be cancelled and freed.
5092	*
5093	* long bpf_timer_start(struct bpf_timer *timer, u64 nsecs, u64 flags)
5094	* Description
5095	* Set timer expiration N nanoseconds from the current time. The
5096	* configured callback will be invoked in soft irq context on some cpu
5097	* and will not repeat unless another bpf_timer_start() is made.
5098	* In such case the next invocation can migrate to a different cpu.
5099	* Since struct bpf_timer is a field inside map element the map
5100	* owns the timer. The bpf_timer_set_callback() will increment refcnt
5101	* of BPF program to make sure that callback_fn code stays valid.
5102	* When user space reference to a map reaches zero all timers
5103	* in a map are cancelled and corresponding program's refcnts are
5104	* decremented. This is done to make sure that Ctrl-C of a user
5105	* process doesn't leave any timers running. If map is pinned in
5106	* bpffs the callback_fn can re-arm itself indefinitely.
5107	* bpf_map_update/delete_elem() helpers and user space sys_bpf commands
5108	* cancel and free the timer in the given map element.
5109	* The map can contain timers that invoke callback_fn-s from different
5110	* programs. The same callback_fn can serve different timers from
5111	* different maps if key/value layout matches across maps.
5112	* Every bpf_timer_set_callback() can have different callback_fn.
5113	*
5114	* flags can be one of:
5115	*
5116	* BPF_F_TIMER_ABS
5117	* Start the timer in absolute expire value instead of the
5118	* default relative one.
5119	* BPF_F_TIMER_CPU_PIN
5120	* Timer will be pinned to the CPU of the caller.
5121	*
5122	* Return
5123	* 0 on success.
5124	* -EINVAL if timer was not initialized with bpf_timer_init() earlier
5125	* or invalid flags are passed.
5126	*
5127	* long bpf_timer_cancel(struct bpf_timer *timer)
5128	* Description
5129	* Cancel the timer and wait for callback_fn to finish if it was running.
5130	* Return
5131	* 0 if the timer was not active.
5132	* 1 if the timer was active.
5133	* -EINVAL if timer was not initialized with bpf_timer_init() earlier.
5134	* -EDEADLK if callback_fn tried to call bpf_timer_cancel() on its
5135	* own timer which would have led to a deadlock otherwise.
5136	*
5137	* u64 bpf_get_func_ip(void *ctx)
5138	* Description
5139	* Get address of the traced function (for tracing and kprobe programs).
5140	*
5141	* When called for kprobe program attached as uprobe it returns
5142	* probe address for both entry and return uprobe.
5143	*
5144	* Return
5145	* Address of the traced function for kprobe.
5146	* 0 for kprobes placed within the function (not at the entry).
5147	* Address of the probe for uprobe and return uprobe.
5148	*
5149	* u64 bpf_get_attach_cookie(void *ctx)
5150	* Description
5151	* Get bpf_cookie value provided (optionally) during the program
5152	* attachment. It might be different for each individual
5153	* attachment, even if BPF program itself is the same.
5154	* Expects BPF program context ctx as a first argument.
5155	*
5156	* Supported for the following program types:
5157	* - kprobe/uprobe;
5158	* - tracepoint;
5159	* - perf_event.
5160	* Return
5161	* Value specified by user at BPF link creation/attachment time
5162	* or 0, if it was not specified.
5163	*
5164	* long bpf_task_pt_regs(struct task_struct *task)
5165	* Description
5166	* Get the struct pt_regs associated with task.
5167	* Return
5168	* A pointer to struct pt_regs.
5169	*
5170	* long bpf_get_branch_snapshot(void *entries, u32 size, u64 flags)
5171	* Description
5172	* Get branch trace from hardware engines like Intel LBR. The
5173	* hardware engine is stopped shortly after the helper is
5174	* called. Therefore, the user need to filter branch entries
5175	* based on the actual use case. To capture branch trace
5176	* before the trigger point of the BPF program, the helper
5177	* should be called at the beginning of the BPF program.
5178	*
5179	* The data is stored as struct perf_branch_entry into output
5180	* buffer entries. size is the size of entries in bytes.
5181	* flags is reserved for now and must be zero.
5182	*
5183	* Return
5184	* On success, number of bytes written to buf. On error, a
5185	* negative value.
5186	*
5187	* -EINVAL if flags is not zero.
5188	*
5189	* -ENOENT if architecture does not support branch records.
5190	*
5191	* long bpf_trace_vprintk(const char fmt, u32 fmt_size, const void data, u32 data_len)
5192	* Description
5193	* Behaves like bpf_trace_printk\ () helper, but takes an array of u64
5194	* to format and can handle more format args as a result.
5195	*
5196	* Arguments are to be used as in bpf_seq_printf\ () helper.
5197	* Return
5198	* The number of bytes written to the buffer, or a negative error
5199	* in case of failure.
5200	*
5201	* struct unix_sock bpf_skc_to_unix_sock(void sk)
5202	* Description
5203	* Dynamically cast a sk pointer to a unix_sock pointer.
5204	* Return
5205	* sk if casting is valid, or NULL otherwise.
5206	*
5207	* long bpf_kallsyms_lookup_name(const char name, int name_sz, int flags, u64 res)
5208	* Description
5209	* Get the address of a kernel symbol, returned in res. res is
5210	* set to 0 if the symbol is not found.
5211	* Return
5212	* On success, zero. On error, a negative value.
5213	*
5214	* -EINVAL if flags is not zero.
5215	*
5216	* -EINVAL if string name is not the same size as name_sz.
5217	*
5218	* -ENOENT if symbol is not found.
5219	*
5220	* -EPERM if caller does not have permission to obtain kernel address.
5221	*
5222	* long bpf_find_vma(struct task_struct task, u64 addr, void callback_fn, void *callback_ctx, u64 flags)
5223	* Description
5224	* Find vma of task that contains addr, call callback_fn
5225	* function with task, vma, and callback_ctx.
5226	* The callback_fn should be a static function and
5227	* the callback_ctx should be a pointer to the stack.
5228	* The flags is used to control certain aspects of the helper.
5229	* Currently, the flags must be 0.
5230	*
5231	* The expected callback signature is
5232	*
5233	* long (\callback_fn)(struct task_struct \task, struct vm_area_struct \vma, void \callback_ctx);
5234	*
5235	* Return
5236	* 0 on success.
5237	* -ENOENT if task->mm is NULL, or no vma contains addr.
5238	* -EBUSY if failed to try lock mmap_lock.
5239	* -EINVAL for invalid flags.
5240	*
5241	* long bpf_loop(u32 nr_loops, void callback_fn, void callback_ctx, u64 flags)
5242	* Description
5243	* For nr_loops, call callback_fn function
5244	* with callback_ctx as the context parameter.
5245	* The callback_fn should be a static function and
5246	* the callback_ctx should be a pointer to the stack.
5247	* The flags is used to control certain aspects of the helper.
5248	* Currently, the flags must be 0. Currently, nr_loops is
5249	* limited to 1 << 23 (~8 million) loops.
5250	*
5251	* long (\callback_fn)(u32 index, void \ctx);
5252	*
5253	* where index is the current index in the loop. The index
5254	* is zero-indexed.
5255	*
5256	* If callback_fn returns 0, the helper will continue to the next
5257	* loop. If return value is 1, the helper will skip the rest of
5258	* the loops and return. Other return values are not used now,
5259	* and will be rejected by the verifier.
5260	*
5261	* Return
5262	* The number of loops performed, -EINVAL for invalid flags,
5263	* -E2BIG if nr_loops exceeds the maximum number of loops.
5264	*
5265	* long bpf_strncmp(const char s1, u32 s1_sz, const char s2)
5266	* Description
5267	* Do strncmp() between s1 and s2. s1 doesn't need
5268	* to be null-terminated and s1_sz is the maximum storage
5269	* size of s1. s2 must be a read-only string.
5270	* Return
5271	* An integer less than, equal to, or greater than zero
5272	* if the first s1_sz bytes of s1 is found to be
5273	* less than, to match, or be greater than s2.
5274	*
5275	* long bpf_get_func_arg(void ctx, u32 n, u64 value)
5276	* Description
5277	* Get n-th argument register (zero based) of the traced function (for tracing programs)
5278	* returned in value.
5279	*
5280	* Return
5281	* 0 on success.
5282	* -EINVAL if n >= argument register count of traced function.
5283	*
5284	* long bpf_get_func_ret(void ctx, u64 value)
5285	* Description
5286	* Get return value of the traced function (for tracing programs)
5287	* in value.
5288	*
5289	* Return
5290	* 0 on success.
5291	* -EOPNOTSUPP for tracing programs other than BPF_TRACE_FEXIT or BPF_MODIFY_RETURN.
5292	*
5293	* long bpf_get_func_arg_cnt(void *ctx)
5294	* Description
5295	* Get number of registers of the traced function (for tracing programs) where
5296	* function arguments are stored in these registers.
5297	*
5298	* Return
5299	* The number of argument registers of the traced function.
5300	*
5301	* int bpf_get_retval(void)
5302	* Description
5303	* Get the BPF program's return value that will be returned to the upper layers.
5304	*
5305	* This helper is currently supported by cgroup programs and only by the hooks
5306	* where BPF program's return value is returned to the userspace via errno.
5307	* Return
5308	* The BPF program's return value.
5309	*
5310	* int bpf_set_retval(int retval)
5311	* Description
5312	* Set the BPF program's return value that will be returned to the upper layers.
5313	*
5314	* This helper is currently supported by cgroup programs and only by the hooks
5315	* where BPF program's return value is returned to the userspace via errno.
5316	*
5317	* Note that there is the following corner case where the program exports an error
5318	* via bpf_set_retval but signals success via 'return 1':
5319	*
5320	* bpf_set_retval(-EPERM);
5321	* return 1;
5322	*
5323	* In this case, the BPF program's return value will use helper's -EPERM. This
5324	* still holds true for cgroup/bind{4,6} which supports extra 'return 3' success case.
5325	*
5326	* Return
5327	* 0 on success, or a negative error in case of failure.
5328	*
5329	* u64 bpf_xdp_get_buff_len(struct xdp_buff *xdp_md)
5330	* Description
5331	* Get the total size of a given xdp buff (linear and paged area)
5332	* Return
5333	* The total size of a given xdp buffer.
5334	*
5335	* long bpf_xdp_load_bytes(struct xdp_buff xdp_md, u32 offset, void buf, u32 len)
5336	* Description
5337	* This helper is provided as an easy way to load data from a
5338	* xdp buffer. It can be used to load len bytes from offset from
5339	* the frame associated to xdp_md, into the buffer pointed by
5340	* buf.
5341	* Return
5342	* 0 on success, or a negative error in case of failure.
5343	*
5344	* long bpf_xdp_store_bytes(struct xdp_buff xdp_md, u32 offset, void buf, u32 len)
5345	* Description
5346	* Store len bytes from buffer buf into the frame
5347	* associated to xdp_md, at offset.
5348	* Return
5349	* 0 on success, or a negative error in case of failure.
5350	*
5351	* long bpf_copy_from_user_task(void dst, u32 size, const void user_ptr, struct task_struct *tsk, u64 flags)
5352	* Description
5353	* Read size bytes from user space address user_ptr in tsk's
5354	* address space, and stores the data in dst. flags is not
5355	* used yet and is provided for future extensibility. This helper
5356	* can only be used by sleepable programs.
5357	* Return
5358	* 0 on success, or a negative error in case of failure. On error
5359	* dst buffer is zeroed out.
5360	*
5361	* long bpf_skb_set_tstamp(struct sk_buff *skb, u64 tstamp, u32 tstamp_type)
5362	* Description
5363	* Change the __sk_buff->tstamp_type to tstamp_type
5364	* and set tstamp to the __sk_buff->tstamp together.
5365	*
5366	* If there is no need to change the __sk_buff->tstamp_type,
5367	* the tstamp value can be directly written to __sk_buff->tstamp
5368	* instead.
5369	*
5370	* BPF_SKB_TSTAMP_DELIVERY_MONO is the only tstamp that
5371	* will be kept during bpf_redirect_*(). A non zero
5372	* tstamp must be used with the BPF_SKB_TSTAMP_DELIVERY_MONO
5373	* tstamp_type.
5374	*
5375	* A BPF_SKB_TSTAMP_UNSPEC tstamp_type can only be used
5376	* with a zero tstamp.
5377	*
5378	* Only IPv4 and IPv6 skb->protocol are supported.
5379	*
5380	* This function is most useful when it needs to set a
5381	* mono delivery time to __sk_buff->tstamp and then
5382	* bpf_redirect_*() to the egress of an iface. For example,
5383	* changing the (rcv) timestamp in __sk_buff->tstamp at
5384	* ingress to a mono delivery time and then bpf_redirect_*()
5385	* to sch_fq@phy-dev.
5386	* Return
5387	* 0 on success.
5388	* -EINVAL for invalid input
5389	* -EOPNOTSUPP for unsupported protocol
5390	*
5391	* long bpf_ima_file_hash(struct file file, void dst, u32 size)
5392	* Description
5393	* Returns a calculated IMA hash of the file.
5394	* If the hash is larger than size, then only size
5395	* bytes will be copied to dst
5396	* Return
5397	* The hash_algo is returned on success,
5398	* -EOPNOTSUP if the hash calculation failed or -EINVAL if
5399	* invalid arguments are passed.
5400	*
5401	* void bpf_kptr_xchg(void map_value, void *ptr)
5402	* Description
5403	* Exchange kptr at pointer map_value with ptr, and return the
5404	* old value. ptr can be NULL, otherwise it must be a referenced
5405	* pointer which will be released when this helper is called.
5406	* Return
5407	* The old value of kptr (which can be NULL). The returned pointer
5408	* if not NULL, is a reference which must be released using its
5409	* corresponding release function, or moved into a BPF map before
5410	* program exit.
5411	*
5412	* void bpf_map_lookup_percpu_elem(struct bpf_map map, const void *key, u32 cpu)
5413	* Description
5414	* Perform a lookup in percpu map for an entry associated to
5415	* key on cpu.
5416	* Return
5417	* Map value associated to key on cpu, or NULL if no entry
5418	* was found or cpu is invalid.
5419	*
5420	* struct mptcp_sock bpf_skc_to_mptcp_sock(void sk)
5421	* Description
5422	* Dynamically cast a sk pointer to a mptcp_sock pointer.
5423	* Return
5424	* sk if casting is valid, or NULL otherwise.
5425	*
5426	* long bpf_dynptr_from_mem(void data, u32 size, u64 flags, struct bpf_dynptr ptr)
5427	* Description
5428	* Get a dynptr to local memory data.
5429	*
5430	* data must be a ptr to a map value.
5431	* The maximum size supported is DYNPTR_MAX_SIZE.
5432	* flags is currently unused.
5433	* Return
5434	* 0 on success, -E2BIG if the size exceeds DYNPTR_MAX_SIZE,
5435	* -EINVAL if flags is not 0.
5436	*
5437	* long bpf_ringbuf_reserve_dynptr(void ringbuf, u32 size, u64 flags, struct bpf_dynptr ptr)
5438	* Description
5439	* Reserve size bytes of payload in a ring buffer ringbuf
5440	* through the dynptr interface. flags must be 0.
5441	*
5442	* Please note that a corresponding bpf_ringbuf_submit_dynptr or
5443	* bpf_ringbuf_discard_dynptr must be called on ptr, even if the
5444	* reservation fails. This is enforced by the verifier.
5445	* Return
5446	* 0 on success, or a negative error in case of failure.
5447	*
5448	* void bpf_ringbuf_submit_dynptr(struct bpf_dynptr *ptr, u64 flags)
5449	* Description
5450	* Submit reserved ring buffer sample, pointed to by data,
5451	* through the dynptr interface. This is a no-op if the dynptr is
5452	* invalid/null.
5453	*
5454	* For more information on flags, please see
5455	* 'bpf_ringbuf_submit'.
5456	* Return
5457	* Nothing. Always succeeds.
5458	*
5459	* void bpf_ringbuf_discard_dynptr(struct bpf_dynptr *ptr, u64 flags)
5460	* Description
5461	* Discard reserved ring buffer sample through the dynptr
5462	* interface. This is a no-op if the dynptr is invalid/null.
5463	*
5464	* For more information on flags, please see
5465	* 'bpf_ringbuf_discard'.
5466	* Return
5467	* Nothing. Always succeeds.
5468	*
5469	* long bpf_dynptr_read(void dst, u32 len, const struct bpf_dynptr src, u32 offset, u64 flags)
5470	* Description
5471	* Read len bytes from src into dst, starting from offset
5472	* into src.
5473	* flags is currently unused.
5474	* Return
5475	* 0 on success, -E2BIG if offset + len exceeds the length
5476	* of src's data, -EINVAL if src is an invalid dynptr or if
5477	* flags is not 0.
5478	*
5479	* long bpf_dynptr_write(const struct bpf_dynptr dst, u32 offset, void src, u32 len, u64 flags)
5480	* Description
5481	* Write len bytes from src into dst, starting from offset
5482	* into dst.
5483	*
5484	* flags must be 0 except for skb-type dynptrs.
5485	*
5486	* For skb-type dynptrs:
5487	* * All data slices of the dynptr are automatically
5488	* invalidated after bpf_dynptr_write\ (). This is
5489	* because writing may pull the skb and change the
5490	* underlying packet buffer.
5491	*
5492	* * For flags, please see the flags accepted by
5493	* bpf_skb_store_bytes\ ().
5494	* Return
5495	* 0 on success, -E2BIG if offset + len exceeds the length
5496	* of dst's data, -EINVAL if dst is an invalid dynptr or if dst
5497	* is a read-only dynptr or if flags is not correct. For skb-type dynptrs,
5498	* other errors correspond to errors returned by bpf_skb_store_bytes\ ().
5499	*
5500	* void bpf_dynptr_data(const struct bpf_dynptr ptr, u32 offset, u32 len)
5501	* Description
5502	* Get a pointer to the underlying dynptr data.
5503	*
5504	* len must be a statically known value. The returned data slice
5505	* is invalidated whenever the dynptr is invalidated.
5506	*
5507	* skb and xdp type dynptrs may not use bpf_dynptr_data. They should
5508	* instead use bpf_dynptr_slice and bpf_dynptr_slice_rdwr.
5509	* Return
5510	* Pointer to the underlying dynptr data, NULL if the dynptr is
5511	* read-only, if the dynptr is invalid, or if the offset and length
5512	* is out of bounds.
5513	*
5514	* s64 bpf_tcp_raw_gen_syncookie_ipv4(struct iphdr iph, struct tcphdr th, u32 th_len)
5515	* Description
5516	* Try to issue a SYN cookie for the packet with corresponding
5517	* IPv4/TCP headers, iph and th, without depending on a
5518	* listening socket.
5519	*
5520	* iph points to the IPv4 header.
5521	*
5522	* th points to the start of the TCP header, while th_len
5523	* contains the length of the TCP header (at least
5524	* sizeof\ (struct tcphdr)).
5525	* Return
5526	* On success, lower 32 bits hold the generated SYN cookie in
5527	* followed by 16 bits which hold the MSS value for that cookie,
5528	* and the top 16 bits are unused.
5529	*
5530	* On failure, the returned value is one of the following:
5531	*
5532	* -EINVAL if th_len is invalid.
5533	*
5534	* s64 bpf_tcp_raw_gen_syncookie_ipv6(struct ipv6hdr iph, struct tcphdr th, u32 th_len)
5535	* Description
5536	* Try to issue a SYN cookie for the packet with corresponding
5537	* IPv6/TCP headers, iph and th, without depending on a
5538	* listening socket.
5539	*
5540	* iph points to the IPv6 header.
5541	*
5542	* th points to the start of the TCP header, while th_len
5543	* contains the length of the TCP header (at least
5544	* sizeof\ (struct tcphdr)).
5545	* Return
5546	* On success, lower 32 bits hold the generated SYN cookie in
5547	* followed by 16 bits which hold the MSS value for that cookie,
5548	* and the top 16 bits are unused.
5549	*
5550	* On failure, the returned value is one of the following:
5551	*
5552	* -EINVAL if th_len is invalid.
5553	*
5554	* -EPROTONOSUPPORT if CONFIG_IPV6 is not builtin.
5555	*
5556	* long bpf_tcp_raw_check_syncookie_ipv4(struct iphdr iph, struct tcphdr th)
5557	* Description
5558	* Check whether iph and th contain a valid SYN cookie ACK
5559	* without depending on a listening socket.
5560	*
5561	* iph points to the IPv4 header.
5562	*
5563	* th points to the TCP header.
5564	* Return
5565	* 0 if iph and th are a valid SYN cookie ACK.
5566	*
5567	* On failure, the returned value is one of the following:
5568	*
5569	* -EACCES if the SYN cookie is not valid.
5570	*
5571	* long bpf_tcp_raw_check_syncookie_ipv6(struct ipv6hdr iph, struct tcphdr th)
5572	* Description
5573	* Check whether iph and th contain a valid SYN cookie ACK
5574	* without depending on a listening socket.
5575	*
5576	* iph points to the IPv6 header.
5577	*
5578	* th points to the TCP header.
5579	* Return
5580	* 0 if iph and th are a valid SYN cookie ACK.
5581	*
5582	* On failure, the returned value is one of the following:
5583	*
5584	* -EACCES if the SYN cookie is not valid.
5585	*
5586	* -EPROTONOSUPPORT if CONFIG_IPV6 is not builtin.
5587	*
5588	* u64 bpf_ktime_get_tai_ns(void)
5589	* Description
5590	* A nonsettable system-wide clock derived from wall-clock time but
5591	* ignoring leap seconds. This clock does not experience
5592	* discontinuities and backwards jumps caused by NTP inserting leap
5593	* seconds as CLOCK_REALTIME does.
5594	*
5595	* See: clock_gettime\ (CLOCK_TAI)
5596	* Return
5597	* Current ktime.
5598	*
5599	* long bpf_user_ringbuf_drain(struct bpf_map map, void callback_fn, void *ctx, u64 flags)
5600	* Description
5601	* Drain samples from the specified user ring buffer, and invoke
5602	* the provided callback for each such sample:
5603	*
5604	* long (\callback_fn)(const struct bpf_dynptr \dynptr, void \*ctx);
5605	*
5606	* If callback_fn returns 0, the helper will continue to try
5607	* and drain the next sample, up to a maximum of
5608	* BPF_MAX_USER_RINGBUF_SAMPLES samples. If the return value is 1,
5609	* the helper will skip the rest of the samples and return. Other
5610	* return values are not used now, and will be rejected by the
5611	* verifier.
5612	* Return
5613	* The number of drained samples if no error was encountered while
5614	* draining samples, or 0 if no samples were present in the ring
5615	* buffer. If a user-space producer was epoll-waiting on this map,
5616	* and at least one sample was drained, they will receive an event
5617	* notification notifying them of available space in the ring
5618	* buffer. If the BPF_RB_NO_WAKEUP flag is passed to this
5619	* function, no wakeup notification will be sent. If the
5620	* BPF_RB_FORCE_WAKEUP flag is passed, a wakeup notification will
5621	* be sent even if no sample was drained.
5622	*
5623	* On failure, the returned value is one of the following:
5624	*
5625	* -EBUSY if the ring buffer is contended, and another calling
5626	* context was concurrently draining the ring buffer.
5627	*
5628	* -EINVAL if user-space is not properly tracking the ring
5629	* buffer due to the producer position not being aligned to 8
5630	* bytes, a sample not being aligned to 8 bytes, or the producer
5631	* position not matching the advertised length of a sample.
5632	*
5633	* -E2BIG if user-space has tried to publish a sample which is
5634	* larger than the size of the ring buffer, or which cannot fit
5635	* within a struct bpf_dynptr.
5636	*
5637	* void bpf_cgrp_storage_get(struct bpf_map map, struct cgroup cgroup, void value, u64 flags)
5638	* Description
5639	* Get a bpf_local_storage from the cgroup.
5640	*
5641	* Logically, it could be thought of as getting the value from
5642	* a map with cgroup as the key. From this
5643	* perspective, the usage is not much different from
5644	* bpf_map_lookup_elem\ (map, &\ cgroup) except this
5645	* helper enforces the key must be a cgroup struct and the map must also
5646	* be a BPF_MAP_TYPE_CGRP_STORAGE.
5647	*
5648	* In reality, the local-storage value is embedded directly inside of the
5649	* cgroup object itself, rather than being located in the
5650	* BPF_MAP_TYPE_CGRP_STORAGE map. When the local-storage value is
5651	* queried for some map on a cgroup object, the kernel will perform an
5652	* O(n) iteration over all of the live local-storage values for that
5653	* cgroup object until the local-storage value for the map is found.
5654	*
5655	* An optional flags (BPF_LOCAL_STORAGE_GET_F_CREATE) can be
5656	* used such that a new bpf_local_storage will be
5657	* created if one does not exist. value can be used
5658	* together with BPF_LOCAL_STORAGE_GET_F_CREATE to specify
5659	* the initial value of a bpf_local_storage. If value is
5660	* NULL, the new bpf_local_storage will be zero initialized.
5661	* Return
5662	* A bpf_local_storage pointer is returned on success.
5663	*
5664	* NULL if not found or there was an error in adding
5665	* a new bpf_local_storage.
5666	*
5667	* long bpf_cgrp_storage_delete(struct bpf_map map, struct cgroup cgroup)
5668	* Description
5669	* Delete a bpf_local_storage from a cgroup.
5670	* Return
5671	* 0 on success.
5672	*
5673	* -ENOENT if the bpf_local_storage cannot be found.
5674	*/
5675	#define ___BPF_FUNC_MAPPER(FN, ctx...) \
5676	FN(unspec, 0, ##ctx) \
5677	FN(map_lookup_elem, 1, ##ctx) \
5678	FN(map_update_elem, 2, ##ctx) \
5679	FN(map_delete_elem, 3, ##ctx) \
5680	FN(probe_read, 4, ##ctx) \
5681	FN(ktime_get_ns, 5, ##ctx) \
5682	FN(trace_printk, 6, ##ctx) \
5683	FN(get_prandom_u32, 7, ##ctx) \
5684	FN(get_smp_processor_id, 8, ##ctx) \
5685	FN(skb_store_bytes, 9, ##ctx) \
5686	FN(l3_csum_replace, 10, ##ctx) \
5687	FN(l4_csum_replace, 11, ##ctx) \
5688	FN(tail_call, 12, ##ctx) \
5689	FN(clone_redirect, 13, ##ctx) \
5690	FN(get_current_pid_tgid, 14, ##ctx) \
5691	FN(get_current_uid_gid, 15, ##ctx) \
5692	FN(get_current_comm, 16, ##ctx) \
5693	FN(get_cgroup_classid, 17, ##ctx) \
5694	FN(skb_vlan_push, 18, ##ctx) \
5695	FN(skb_vlan_pop, 19, ##ctx) \
5696	FN(skb_get_tunnel_key, 20, ##ctx) \
5697	FN(skb_set_tunnel_key, 21, ##ctx) \
5698	FN(perf_event_read, 22, ##ctx) \
5699	FN(redirect, 23, ##ctx) \
5700	FN(get_route_realm, 24, ##ctx) \
5701	FN(perf_event_output, 25, ##ctx) \
5702	FN(skb_load_bytes, 26, ##ctx) \
5703	FN(get_stackid, 27, ##ctx) \
5704	FN(csum_diff, 28, ##ctx) \
5705	FN(skb_get_tunnel_opt, 29, ##ctx) \
5706	FN(skb_set_tunnel_opt, 30, ##ctx) \
5707	FN(skb_change_proto, 31, ##ctx) \
5708	FN(skb_change_type, 32, ##ctx) \
5709	FN(skb_under_cgroup, 33, ##ctx) \
5710	FN(get_hash_recalc, 34, ##ctx) \
5711	FN(get_current_task, 35, ##ctx) \
5712	FN(probe_write_user, 36, ##ctx) \
5713	FN(current_task_under_cgroup, 37, ##ctx) \
5714	FN(skb_change_tail, 38, ##ctx) \
5715	FN(skb_pull_data, 39, ##ctx) \
5716	FN(csum_update, 40, ##ctx) \
5717	FN(set_hash_invalid, 41, ##ctx) \
5718	FN(get_numa_node_id, 42, ##ctx) \
5719	FN(skb_change_head, 43, ##ctx) \
5720	FN(xdp_adjust_head, 44, ##ctx) \
5721	FN(probe_read_str, 45, ##ctx) \
5722	FN(get_socket_cookie, 46, ##ctx) \
5723	FN(get_socket_uid, 47, ##ctx) \
5724	FN(set_hash, 48, ##ctx) \
5725	FN(setsockopt, 49, ##ctx) \
5726	FN(skb_adjust_room, 50, ##ctx) \
5727	FN(redirect_map, 51, ##ctx) \
5728	FN(sk_redirect_map, 52, ##ctx) \
5729	FN(sock_map_update, 53, ##ctx) \
5730	FN(xdp_adjust_meta, 54, ##ctx) \
5731	FN(perf_event_read_value, 55, ##ctx) \
5732	FN(perf_prog_read_value, 56, ##ctx) \
5733	FN(getsockopt, 57, ##ctx) \
5734	FN(override_return, 58, ##ctx) \
5735	FN(sock_ops_cb_flags_set, 59, ##ctx) \
5736	FN(msg_redirect_map, 60, ##ctx) \
5737	FN(msg_apply_bytes, 61, ##ctx) \
5738	FN(msg_cork_bytes, 62, ##ctx) \
5739	FN(msg_pull_data, 63, ##ctx) \
5740	FN(bind, 64, ##ctx) \
5741	FN(xdp_adjust_tail, 65, ##ctx) \
5742	FN(skb_get_xfrm_state, 66, ##ctx) \
5743	FN(get_stack, 67, ##ctx) \
5744	FN(skb_load_bytes_relative, 68, ##ctx) \
5745	FN(fib_lookup, 69, ##ctx) \
5746	FN(sock_hash_update, 70, ##ctx) \
5747	FN(msg_redirect_hash, 71, ##ctx) \
5748	FN(sk_redirect_hash, 72, ##ctx) \
5749	FN(lwt_push_encap, 73, ##ctx) \
5750	FN(lwt_seg6_store_bytes, 74, ##ctx) \
5751	FN(lwt_seg6_adjust_srh, 75, ##ctx) \
5752	FN(lwt_seg6_action, 76, ##ctx) \
5753	FN(rc_repeat, 77, ##ctx) \
5754	FN(rc_keydown, 78, ##ctx) \
5755	FN(skb_cgroup_id, 79, ##ctx) \
5756	FN(get_current_cgroup_id, 80, ##ctx) \
5757	FN(get_local_storage, 81, ##ctx) \
5758	FN(sk_select_reuseport, 82, ##ctx) \
5759	FN(skb_ancestor_cgroup_id, 83, ##ctx) \
5760	FN(sk_lookup_tcp, 84, ##ctx) \
5761	FN(sk_lookup_udp, 85, ##ctx) \
5762	FN(sk_release, 86, ##ctx) \
5763	FN(map_push_elem, 87, ##ctx) \
5764	FN(map_pop_elem, 88, ##ctx) \
5765	FN(map_peek_elem, 89, ##ctx) \
5766	FN(msg_push_data, 90, ##ctx) \
5767	FN(msg_pop_data, 91, ##ctx) \
5768	FN(rc_pointer_rel, 92, ##ctx) \
5769	FN(spin_lock, 93, ##ctx) \
5770	FN(spin_unlock, 94, ##ctx) \
5771	FN(sk_fullsock, 95, ##ctx) \
5772	FN(tcp_sock, 96, ##ctx) \
5773	FN(skb_ecn_set_ce, 97, ##ctx) \
5774	FN(get_listener_sock, 98, ##ctx) \
5775	FN(skc_lookup_tcp, 99, ##ctx) \
5776	FN(tcp_check_syncookie, 100, ##ctx) \
5777	FN(sysctl_get_name, 101, ##ctx) \
5778	FN(sysctl_get_current_value, 102, ##ctx) \
5779	FN(sysctl_get_new_value, 103, ##ctx) \
5780	FN(sysctl_set_new_value, 104, ##ctx) \
5781	FN(strtol, 105, ##ctx) \
5782	FN(strtoul, 106, ##ctx) \
5783	FN(sk_storage_get, 107, ##ctx) \
5784	FN(sk_storage_delete, 108, ##ctx) \
5785	FN(send_signal, 109, ##ctx) \
5786	FN(tcp_gen_syncookie, 110, ##ctx) \
5787	FN(skb_output, 111, ##ctx) \
5788	FN(probe_read_user, 112, ##ctx) \
5789	FN(probe_read_kernel, 113, ##ctx) \
5790	FN(probe_read_user_str, 114, ##ctx) \
5791	FN(probe_read_kernel_str, 115, ##ctx) \
5792	FN(tcp_send_ack, 116, ##ctx) \
5793	FN(send_signal_thread, 117, ##ctx) \
5794	FN(jiffies64, 118, ##ctx) \
5795	FN(read_branch_records, 119, ##ctx) \
5796	FN(get_ns_current_pid_tgid, 120, ##ctx) \
5797	FN(xdp_output, 121, ##ctx) \
5798	FN(get_netns_cookie, 122, ##ctx) \
5799	FN(get_current_ancestor_cgroup_id, 123, ##ctx) \
5800	FN(sk_assign, 124, ##ctx) \
5801	FN(ktime_get_boot_ns, 125, ##ctx) \
5802	FN(seq_printf, 126, ##ctx) \
5803	FN(seq_write, 127, ##ctx) \
5804	FN(sk_cgroup_id, 128, ##ctx) \
5805	FN(sk_ancestor_cgroup_id, 129, ##ctx) \
5806	FN(ringbuf_output, 130, ##ctx) \
5807	FN(ringbuf_reserve, 131, ##ctx) \
5808	FN(ringbuf_submit, 132, ##ctx) \
5809	FN(ringbuf_discard, 133, ##ctx) \
5810	FN(ringbuf_query, 134, ##ctx) \
5811	FN(csum_level, 135, ##ctx) \
5812	FN(skc_to_tcp6_sock, 136, ##ctx) \
5813	FN(skc_to_tcp_sock, 137, ##ctx) \
5814	FN(skc_to_tcp_timewait_sock, 138, ##ctx) \
5815	FN(skc_to_tcp_request_sock, 139, ##ctx) \
5816	FN(skc_to_udp6_sock, 140, ##ctx) \
5817	FN(get_task_stack, 141, ##ctx) \
5818	FN(load_hdr_opt, 142, ##ctx) \
5819	FN(store_hdr_opt, 143, ##ctx) \
5820	FN(reserve_hdr_opt, 144, ##ctx) \
5821	FN(inode_storage_get, 145, ##ctx) \
5822	FN(inode_storage_delete, 146, ##ctx) \
5823	FN(d_path, 147, ##ctx) \
5824	FN(copy_from_user, 148, ##ctx) \
5825	FN(snprintf_btf, 149, ##ctx) \
5826	FN(seq_printf_btf, 150, ##ctx) \
5827	FN(skb_cgroup_classid, 151, ##ctx) \
5828	FN(redirect_neigh, 152, ##ctx) \
5829	FN(per_cpu_ptr, 153, ##ctx) \
5830	FN(this_cpu_ptr, 154, ##ctx) \
5831	FN(redirect_peer, 155, ##ctx) \
5832	FN(task_storage_get, 156, ##ctx) \
5833	FN(task_storage_delete, 157, ##ctx) \
5834	FN(get_current_task_btf, 158, ##ctx) \
5835	FN(bprm_opts_set, 159, ##ctx) \
5836	FN(ktime_get_coarse_ns, 160, ##ctx) \
5837	FN(ima_inode_hash, 161, ##ctx) \
5838	FN(sock_from_file, 162, ##ctx) \
5839	FN(check_mtu, 163, ##ctx) \
5840	FN(for_each_map_elem, 164, ##ctx) \
5841	FN(snprintf, 165, ##ctx) \
5842	FN(sys_bpf, 166, ##ctx) \
5843	FN(btf_find_by_name_kind, 167, ##ctx) \
5844	FN(sys_close, 168, ##ctx) \
5845	FN(timer_init, 169, ##ctx) \
5846	FN(timer_set_callback, 170, ##ctx) \
5847	FN(timer_start, 171, ##ctx) \
5848	FN(timer_cancel, 172, ##ctx) \
5849	FN(get_func_ip, 173, ##ctx) \
5850	FN(get_attach_cookie, 174, ##ctx) \
5851	FN(task_pt_regs, 175, ##ctx) \
5852	FN(get_branch_snapshot, 176, ##ctx) \
5853	FN(trace_vprintk, 177, ##ctx) \
5854	FN(skc_to_unix_sock, 178, ##ctx) \
5855	FN(kallsyms_lookup_name, 179, ##ctx) \
5856	FN(find_vma, 180, ##ctx) \
5857	FN(loop, 181, ##ctx) \
5858	FN(strncmp, 182, ##ctx) \
5859	FN(get_func_arg, 183, ##ctx) \
5860	FN(get_func_ret, 184, ##ctx) \
5861	FN(get_func_arg_cnt, 185, ##ctx) \
5862	FN(get_retval, 186, ##ctx) \
5863	FN(set_retval, 187, ##ctx) \
5864	FN(xdp_get_buff_len, 188, ##ctx) \
5865	FN(xdp_load_bytes, 189, ##ctx) \
5866	FN(xdp_store_bytes, 190, ##ctx) \
5867	FN(copy_from_user_task, 191, ##ctx) \
5868	FN(skb_set_tstamp, 192, ##ctx) \
5869	FN(ima_file_hash, 193, ##ctx) \
5870	FN(kptr_xchg, 194, ##ctx) \
5871	FN(map_lookup_percpu_elem, 195, ##ctx) \
5872	FN(skc_to_mptcp_sock, 196, ##ctx) \
5873	FN(dynptr_from_mem, 197, ##ctx) \
5874	FN(ringbuf_reserve_dynptr, 198, ##ctx) \
5875	FN(ringbuf_submit_dynptr, 199, ##ctx) \
5876	FN(ringbuf_discard_dynptr, 200, ##ctx) \
5877	FN(dynptr_read, 201, ##ctx) \
5878	FN(dynptr_write, 202, ##ctx) \
5879	FN(dynptr_data, 203, ##ctx) \
5880	FN(tcp_raw_gen_syncookie_ipv4, 204, ##ctx) \
5881	FN(tcp_raw_gen_syncookie_ipv6, 205, ##ctx) \
5882	FN(tcp_raw_check_syncookie_ipv4, 206, ##ctx) \
5883	FN(tcp_raw_check_syncookie_ipv6, 207, ##ctx) \
5884	FN(ktime_get_tai_ns, 208, ##ctx) \
5885	FN(user_ringbuf_drain, 209, ##ctx) \
5886	FN(cgrp_storage_get, 210, ##ctx) \
5887	FN(cgrp_storage_delete, 211, ##ctx) \
5888	/* */
5889
5890	/ backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't*
5891	* know or care about integer value that is now passed as second argument
5892	*/
5893	#define __BPF_FUNC_MAPPER_APPLY(name, value, FN) FN(name),
5894	#define __BPF_FUNC_MAPPER(FN) ___BPF_FUNC_MAPPER(__BPF_FUNC_MAPPER_APPLY, FN)
5895
5896	/ integer value in 'imm' field of BPF_CALL instruction selects which helper*
5897	* function eBPF program intends to call
5898	*/
5899	#define __BPF_ENUM_FN(x, y) BPF_FUNC_ ## x = y,
5900	enum bpf_func_id {
5901	___BPF_FUNC_MAPPER(__BPF_ENUM_FN)
5902	__BPF_FUNC_MAX_ID,
5903	};
5904	#undef __BPF_ENUM_FN
5905
5906	/ All flags used by eBPF helper functions, placed here. /
5907
5908	/ BPF_FUNC_skb_store_bytes flags. /
5909	enum {
5910	BPF_F_RECOMPUTE_CSUM = (`1ULL` << `0`),
5911	BPF_F_INVALIDATE_HASH = (`1ULL` << `1`),
5912	};
5913
5914	/ BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags.*
5915	* First 4 bits are for passing the header field size.
5916	*/
5917	enum {
5918	BPF_F_HDR_FIELD_MASK = `0xfULL`,
5919	};
5920
5921	/ BPF_FUNC_l4_csum_replace flags. /
5922	enum {
5923	BPF_F_PSEUDO_HDR = (`1ULL` << `4`),
5924	BPF_F_MARK_MANGLED_0 = (`1ULL` << `5`),
5925	BPF_F_MARK_ENFORCE = (`1ULL` << `6`),
5926	};
5927
5928	/ BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. /
5929	enum {
5930	BPF_F_INGRESS = (`1ULL` << `0`),
5931	};
5932
5933	/ BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. /
5934	enum {
5935	BPF_F_TUNINFO_IPV6 = (`1ULL` << `0`),
5936	};
5937
5938	/ flags for both BPF_FUNC_get_stackid and BPF_FUNC_get_stack. /
5939	enum {
5940	BPF_F_SKIP_FIELD_MASK = `0xffULL`,
5941	BPF_F_USER_STACK = (`1ULL` << `8`),
5942	/ flags used by BPF_FUNC_get_stackid only. /
5943	BPF_F_FAST_STACK_CMP = (`1ULL` << `9`),
5944	BPF_F_REUSE_STACKID = (`1ULL` << `10`),
5945	/ flags used by BPF_FUNC_get_stack only. /
5946	BPF_F_USER_BUILD_ID = (`1ULL` << `11`),
5947	};
5948
5949	/ BPF_FUNC_skb_set_tunnel_key flags. /
5950	enum {
5951	BPF_F_ZERO_CSUM_TX = (`1ULL` << `1`),
5952	BPF_F_DONT_FRAGMENT = (`1ULL` << `2`),
5953	BPF_F_SEQ_NUMBER = (`1ULL` << `3`),
5954	BPF_F_NO_TUNNEL_KEY = (`1ULL` << `4`),
5955	};
5956
5957	/ BPF_FUNC_skb_get_tunnel_key flags. /
5958	enum {
5959	BPF_F_TUNINFO_FLAGS = (`1ULL` << `4`),
5960	};
5961
5962	/ BPF_FUNC_perf_event_output, BPF_FUNC_perf_event_read and*
5963	* BPF_FUNC_perf_event_read_value flags.
5964	*/
5965	enum {
5966	BPF_F_INDEX_MASK = `0xffffffffULL`,
5967	BPF_F_CURRENT_CPU = BPF_F_INDEX_MASK,
5968	/ BPF_FUNC_perf_event_output for sk_buff input context. /
5969	BPF_F_CTXLEN_MASK = (`0xfffffULL` << `32`),
5970	};
5971
5972	/ Current network namespace /
5973	enum {
5974	BPF_F_CURRENT_NETNS = (-`1L`),
5975	};
5976
5977	/ BPF_FUNC_csum_level level values. /
5978	enum {
5979	BPF_CSUM_LEVEL_QUERY,
5980	BPF_CSUM_LEVEL_INC,
5981	BPF_CSUM_LEVEL_DEC,
5982	BPF_CSUM_LEVEL_RESET,
5983	};
5984
5985	/ BPF_FUNC_skb_adjust_room flags. /
5986	enum {
5987	BPF_F_ADJ_ROOM_FIXED_GSO = (`1ULL` << `0`),
5988	BPF_F_ADJ_ROOM_ENCAP_L3_IPV4 = (`1ULL` << `1`),
5989	BPF_F_ADJ_ROOM_ENCAP_L3_IPV6 = (`1ULL` << `2`),
5990	BPF_F_ADJ_ROOM_ENCAP_L4_GRE = (`1ULL` << `3`),
5991	BPF_F_ADJ_ROOM_ENCAP_L4_UDP = (`1ULL` << `4`),
5992	BPF_F_ADJ_ROOM_NO_CSUM_RESET = (`1ULL` << `5`),
5993	BPF_F_ADJ_ROOM_ENCAP_L2_ETH = (`1ULL` << `6`),
5994	BPF_F_ADJ_ROOM_DECAP_L3_IPV4 = (`1ULL` << `7`),
5995	BPF_F_ADJ_ROOM_DECAP_L3_IPV6 = (`1ULL` << `8`),
5996	};
5997
5998	enum {
5999	BPF_ADJ_ROOM_ENCAP_L2_MASK = `0xff`,
6000	BPF_ADJ_ROOM_ENCAP_L2_SHIFT = `56`,
6001	};
6002
6003	#define BPF_F_ADJ_ROOM_ENCAP_L2(len) (((__u64)len & \
6004	BPF_ADJ_ROOM_ENCAP_L2_MASK) \
6005	<< BPF_ADJ_ROOM_ENCAP_L2_SHIFT)
6006
6007	/ BPF_FUNC_sysctl_get_name flags. /
6008	enum {
6009	BPF_F_SYSCTL_BASE_NAME = (`1ULL` << `0`),
6010	};
6011
6012	/ BPF_FUNC_<kernel_obj>_storage_get flags /
6013	enum {
6014	BPF_LOCAL_STORAGE_GET_F_CREATE = (`1ULL` << `0`),
6015	/ BPF_SK_STORAGE_GET_F_CREATE is only kept for backward compatibility*
6016	* and BPF_LOCAL_STORAGE_GET_F_CREATE must be used instead.
6017	*/
6018	BPF_SK_STORAGE_GET_F_CREATE = BPF_LOCAL_STORAGE_GET_F_CREATE,
6019	};
6020
6021	/ BPF_FUNC_read_branch_records flags. /
6022	enum {
6023	BPF_F_GET_BRANCH_RECORDS_SIZE = (`1ULL` << `0`),
6024	};
6025
6026	/ BPF_FUNC_bpf_ringbuf_commit, BPF_FUNC_bpf_ringbuf_discard, and*
6027	* BPF_FUNC_bpf_ringbuf_output flags.
6028	*/
6029	enum {
6030	BPF_RB_NO_WAKEUP = (`1ULL` << `0`),
6031	BPF_RB_FORCE_WAKEUP = (`1ULL` << `1`),
6032	};
6033
6034	/ BPF_FUNC_bpf_ringbuf_query flags /
6035	enum {
6036	BPF_RB_AVAIL_DATA = `0`,
6037	BPF_RB_RING_SIZE = `1`,
6038	BPF_RB_CONS_POS = `2`,
6039	BPF_RB_PROD_POS = `3`,
6040	};
6041
6042	/ BPF ring buffer constants /
6043	enum {
6044	BPF_RINGBUF_BUSY_BIT = (`1U` << `31`),
6045	BPF_RINGBUF_DISCARD_BIT = (`1U` << `30`),
6046	BPF_RINGBUF_HDR_SZ = `8`,
6047	};
6048
6049	/ BPF_FUNC_sk_assign flags in bpf_sk_lookup context. /
6050	enum {
6051	BPF_SK_LOOKUP_F_REPLACE = (`1ULL` << `0`),
6052	BPF_SK_LOOKUP_F_NO_REUSEPORT = (`1ULL` << `1`),
6053	};
6054
6055	/ Mode for BPF_FUNC_skb_adjust_room helper. /
6056	enum bpf_adj_room_mode {
6057	BPF_ADJ_ROOM_NET,
6058	BPF_ADJ_ROOM_MAC,
6059	};
6060
6061	/ Mode for BPF_FUNC_skb_load_bytes_relative helper. /
6062	enum bpf_hdr_start_off {
6063	BPF_HDR_START_MAC,
6064	BPF_HDR_START_NET,
6065	};
6066
6067	/ Encapsulation type for BPF_FUNC_lwt_push_encap helper. /
6068	enum bpf_lwt_encap_mode {
6069	BPF_LWT_ENCAP_SEG6,
6070	BPF_LWT_ENCAP_SEG6_INLINE,
6071	BPF_LWT_ENCAP_IP,
6072	};
6073
6074	/ Flags for bpf_bprm_opts_set helper /
6075	enum {
6076	BPF_F_BPRM_SECUREEXEC = (`1ULL` << `0`),
6077	};
6078
6079	/ Flags for bpf_redirect_map helper /
6080	enum {
6081	BPF_F_BROADCAST = (`1ULL` << `3`),
6082	BPF_F_EXCLUDE_INGRESS = (`1ULL` << `4`),
6083	};
6084
6085	#define __bpf_md_ptr(type, name) \
6086	union { \
6087	type name; \
6088	__u64 :64; \
6089	} __attribute__((aligned(8)))
6090
6091	enum {
6092	BPF_SKB_TSTAMP_UNSPEC,
6093	BPF_SKB_TSTAMP_DELIVERY_MONO, / tstamp has mono delivery time /
6094	/ For any BPF_SKB_TSTAMP_* that the bpf prog cannot handle,*
6095	* the bpf prog should handle it like BPF_SKB_TSTAMP_UNSPEC
6096	* and try to deduce it by ingress, egress or skb->sk->sk_clockid.
6097	*/
6098	};
6099
6100	/ user accessible mirror of in-kernel sk_buff.*
6101	* new fields can only be added to the end of this structure
6102	*/
6103	struct __sk_buff {
6104	__u32 len;
6105	__u32 pkt_type;
6106	__u32 mark;
6107	__u32 queue_mapping;
6108	__u32 protocol;
6109	__u32 vlan_present;
6110	__u32 vlan_tci;
6111	__u32 vlan_proto;
6112	__u32 priority;
6113	__u32 ingress_ifindex;
6114	__u32 ifindex;
6115	__u32 tc_index;
6116	__u32 cb[`5`];
6117	__u32 hash;
6118	__u32 tc_classid;
6119	__u32 data;
6120	__u32 data_end;
6121	__u32 napi_id;
6122
6123	/ Accessed by BPF_PROG_TYPE_sk_skb types from here to ... /
6124	__u32 family;
6125	__u32 remote_ip4; / Stored in network byte order /
6126	__u32 local_ip4; / Stored in network byte order /
6127	__u32 remote_ip6[`4`]; / Stored in network byte order /
6128	__u32 local_ip6[`4`]; / Stored in network byte order /
6129	__u32 remote_port; / Stored in network byte order /
6130	__u32 local_port; / stored in host byte order /
6131	/ ... here. /
6132
6133	__u32 data_meta;
6134	__bpf_md_ptr(struct bpf_flow_keys *, flow_keys);
6135	__u64 tstamp;
6136	__u32 wire_len;
6137	__u32 gso_segs;
6138	__bpf_md_ptr(struct bpf_sock *, sk);
6139	__u32 gso_size;
6140	__u8 tstamp_type;
6141	__u32 :`24`; / Padding, future use. /
6142	__u64 hwtstamp;
6143	};
6144
6145	struct bpf_tunnel_key {
6146	__u32 tunnel_id;
6147	union {
6148	__u32 remote_ipv4;
6149	__u32 remote_ipv6[`4`];
6150	};
6151	__u8 tunnel_tos;
6152	__u8 tunnel_ttl;
6153	union {
6154	__u16 tunnel_ext; / compat /
6155	__be16 tunnel_flags;
6156	};
6157	__u32 tunnel_label;
6158	union {
6159	__u32 local_ipv4;
6160	__u32 local_ipv6[`4`];
6161	};
6162	};
6163
6164	/ user accessible mirror of in-kernel xfrm_state.*
6165	* new fields can only be added to the end of this structure
6166	*/
6167	struct bpf_xfrm_state {
6168	__u32 reqid;
6169	__u32 spi; / Stored in network byte order /
6170	__u16 family;
6171	__u16 ext; / Padding, future use. /
6172	union {
6173	__u32 remote_ipv4; / Stored in network byte order /
6174	__u32 remote_ipv6[`4`]; / Stored in network byte order /
6175	};
6176	};
6177
6178	/ Generic BPF return codes which all BPF program types may support.*
6179	* The values are binary compatible with their TC_ACT_* counter-part to
6180	* provide backwards compatibility with existing SCHED_CLS and SCHED_ACT
6181	* programs.
6182	*
6183	* XDP is handled seprately, see XDP_*.
6184	*/
6185	enum bpf_ret_code {
6186	BPF_OK = `0`,
6187	/ 1 reserved /
6188	BPF_DROP = `2`,
6189	/ 3-6 reserved /
6190	BPF_REDIRECT = `7`,
6191	/ >127 are reserved for prog type specific return codes.*
6192	*
6193	* BPF_LWT_REROUTE: used by BPF_PROG_TYPE_LWT_IN and
6194	* BPF_PROG_TYPE_LWT_XMIT to indicate that skb had been
6195	* changed and should be routed based on its new L3 header.
6196	* (This is an L3 redirect, as opposed to L2 redirect
6197	* represented by BPF_REDIRECT above).
6198	*/
6199	BPF_LWT_REROUTE = `128`,
6200	/ BPF_FLOW_DISSECTOR_CONTINUE: used by BPF_PROG_TYPE_FLOW_DISSECTOR*
6201	* to indicate that no custom dissection was performed, and
6202	* fallback to standard dissector is requested.
6203	*/
6204	BPF_FLOW_DISSECTOR_CONTINUE = `129`,
6205	};
6206
6207	struct bpf_sock {
6208	__u32 bound_dev_if;
6209	__u32 family;
6210	__u32 type;
6211	__u32 protocol;
6212	__u32 mark;
6213	__u32 priority;
6214	/ IP address also allows 1 and 2 bytes access /
6215	__u32 src_ip4;
6216	__u32 src_ip6[`4`];
6217	__u32 src_port; / host byte order /
6218	__be16 dst_port; / network byte order /
6219	__u16 :`16`; / zero padding /
6220	__u32 dst_ip4;
6221	__u32 dst_ip6[`4`];
6222	__u32 state;
6223	__s32 rx_queue_mapping;
6224	};
6225
6226	struct bpf_tcp_sock {
6227	__u32 snd_cwnd; / Sending congestion window /
6228	__u32 srtt_us; / smoothed round trip time << 3 in usecs /
6229	__u32 rtt_min;
6230	__u32 snd_ssthresh; / Slow start size threshold /
6231	__u32 rcv_nxt; / What we want to receive next /
6232	__u32 snd_nxt; / Next sequence we send /
6233	__u32 snd_una; / First byte we want an ack for /
6234	__u32 mss_cache; / Cached effective mss, not including SACKS /
6235	__u32 ecn_flags; / ECN status bits. /
6236	__u32 rate_delivered; / saved rate sample: packets delivered /
6237	__u32 rate_interval_us; / saved rate sample: time elapsed /
6238	__u32 packets_out; / Packets which are "in flight" /
6239	__u32 retrans_out; / Retransmitted packets out /
6240	__u32 total_retrans; / Total retransmits for entire connection /
6241	__u32 segs_in; / RFC4898 tcpEStatsPerfSegsIn*
6242	* total number of segments in.
6243	*/
6244	__u32 data_segs_in; / RFC4898 tcpEStatsPerfDataSegsIn*
6245	* total number of data segments in.
6246	*/
6247	__u32 segs_out; / RFC4898 tcpEStatsPerfSegsOut*
6248	* The total number of segments sent.
6249	*/
6250	__u32 data_segs_out; / RFC4898 tcpEStatsPerfDataSegsOut*
6251	* total number of data segments sent.
6252	*/
6253	__u32 lost_out; / Lost packets /
6254	__u32 sacked_out; / SACK'd packets /
6255	__u64 bytes_received; / RFC4898 tcpEStatsAppHCThruOctetsReceived*
6256	* sum(delta(rcv_nxt)), or how many bytes
6257	* were acked.
6258	*/
6259	__u64 bytes_acked; / RFC4898 tcpEStatsAppHCThruOctetsAcked*
6260	* sum(delta(snd_una)), or how many bytes
6261	* were acked.
6262	*/
6263	__u32 dsack_dups; / RFC4898 tcpEStatsStackDSACKDups*
6264	* total number of DSACK blocks received
6265	*/
6266	__u32 delivered; / Total data packets delivered incl. rexmits /
6267	__u32 delivered_ce; / Like the above but only ECE marked packets /
6268	__u32 icsk_retransmits; / Number of unrecovered [RTO] timeouts /
6269	};
6270
6271	struct bpf_sock_tuple {
6272	union {
6273	struct {
6274	__be32 saddr;
6275	__be32 daddr;
6276	__be16 sport;
6277	__be16 dport;
6278	} ipv4;
6279	struct {
6280	__be32 saddr[`4`];
6281	__be32 daddr[`4`];
6282	__be16 sport;
6283	__be16 dport;
6284	} ipv6;
6285	};
6286	};
6287
6288	/ (Simplified) user return codes for tcx prog type.*
6289	* A valid tcx program must return one of these defined values. All other
6290	* return codes are reserved for future use. Must remain compatible with
6291	* their TC_ACT_* counter-parts. For compatibility in behavior, unknown
6292	* return codes are mapped to TCX_NEXT.
6293	*/
6294	enum tcx_action_base {
6295	TCX_NEXT = -`1`,
6296	TCX_PASS = `0`,
6297	TCX_DROP = `2`,
6298	TCX_REDIRECT = `7`,
6299	};
6300
6301	struct bpf_xdp_sock {
6302	__u32 queue_id;
6303	};
6304
6305	#define XDP_PACKET_HEADROOM 256
6306
6307	/ User return codes for XDP prog type.*
6308	* A valid XDP program must return one of these defined values. All other
6309	* return codes are reserved for future use. Unknown return codes will
6310	* result in packet drops and a warning via bpf_warn_invalid_xdp_action().
6311	*/
6312	enum xdp_action {
6313	XDP_ABORTED = `0`,
6314	XDP_DROP,
6315	XDP_PASS,
6316	XDP_TX,
6317	XDP_REDIRECT,
6318	};
6319
6320	/ user accessible metadata for XDP packet hook*
6321	* new fields must be added to the end of this structure
6322	*/
6323	struct xdp_md {
6324	__u32 data;
6325	__u32 data_end;
6326	__u32 data_meta;
6327	/ Below access go through struct xdp_rxq_info /
6328	__u32 ingress_ifindex; / rxq->dev->ifindex /
6329	__u32 rx_queue_index; / rxq->queue_index /
6330
6331	__u32 egress_ifindex; / txq->dev->ifindex /
6332	};
6333
6334	/ DEVMAP map-value layout*
6335	*
6336	* The struct data-layout of map-value is a configuration interface.
6337	* New members can only be added to the end of this structure.
6338	*/
6339	struct bpf_devmap_val {
6340	__u32 ifindex; / device index /
6341	union {
6342	int fd; / prog fd on map write /
6343	__u32 id; / prog id on map read /
6344	} bpf_prog;
6345	};
6346
6347	/ CPUMAP map-value layout*
6348	*
6349	* The struct data-layout of map-value is a configuration interface.
6350	* New members can only be added to the end of this structure.
6351	*/
6352	struct bpf_cpumap_val {
6353	__u32 qsize; / queue size to remote target CPU /
6354	union {
6355	int fd; / prog fd on map write /
6356	__u32 id; / prog id on map read /
6357	} bpf_prog;
6358	};
6359
6360	enum sk_action {
6361	SK_DROP = `0`,
6362	SK_PASS,
6363	};
6364
6365	/ user accessible metadata for SK_MSG packet hook, new fields must*
6366	* be added to the end of this structure
6367	*/
6368	struct sk_msg_md {
6369	__bpf_md_ptr(void *, data);
6370	__bpf_md_ptr(void *, data_end);
6371
6372	__u32 family;
6373	__u32 remote_ip4; / Stored in network byte order /
6374	__u32 local_ip4; / Stored in network byte order /
6375	__u32 remote_ip6[`4`]; / Stored in network byte order /
6376	__u32 local_ip6[`4`]; / Stored in network byte order /
6377	__u32 remote_port; / Stored in network byte order /
6378	__u32 local_port; / stored in host byte order /
6379	__u32 size; / Total size of sk_msg /
6380
6381	__bpf_md_ptr(struct bpf_sock , sk); /* current socket /
6382	};
6383
6384	struct sk_reuseport_md {
6385	/*
6386	* Start of directly accessible data. It begins from
6387	* the tcp/udp header.
6388	*/
6389	__bpf_md_ptr(void *, data);
6390	/ End of directly accessible data /
6391	__bpf_md_ptr(void *, data_end);
6392	/*
6393	* Total length of packet (starting from the tcp/udp header).
6394	* Note that the directly accessible bytes (data_end - data)
6395	* could be less than this "len". Those bytes could be
6396	* indirectly read by a helper "bpf_skb_load_bytes()".
6397	*/
6398	__u32 len;
6399	/*
6400	* Eth protocol in the mac header (network byte order). e.g.
6401	* ETH_P_IP(0x0800) and ETH_P_IPV6(0x86DD)
6402	*/
6403	__u32 eth_protocol;
6404	__u32 ip_protocol; / IP protocol. e.g. IPPROTO_TCP, IPPROTO_UDP /
6405	__u32 bind_inany; / Is sock bound to an INANY address? /
6406	__u32 hash; / A hash of the packet 4 tuples /
6407	/ When reuse->migrating_sk is NULL, it is selecting a sk for the*
6408	* new incoming connection request (e.g. selecting a listen sk for
6409	* the received SYN in the TCP case). reuse->sk is one of the sk
6410	* in the reuseport group. The bpf prog can use reuse->sk to learn
6411	* the local listening ip/port without looking into the skb.
6412	*
6413	* When reuse->migrating_sk is not NULL, reuse->sk is closed and
6414	* reuse->migrating_sk is the socket that needs to be migrated
6415	* to another listening socket. migrating_sk could be a fullsock
6416	* sk that is fully established or a reqsk that is in-the-middle
6417	* of 3-way handshake.
6418	*/
6419	__bpf_md_ptr(struct bpf_sock *, sk);
6420	__bpf_md_ptr(struct bpf_sock *, migrating_sk);
6421	};
6422
6423	#define BPF_TAG_SIZE 8
6424
6425	struct bpf_prog_info {
6426	__u32 type;
6427	__u32 id;
6428	__u8 tag[BPF_TAG_SIZE];
6429	__u32 jited_prog_len;
6430	__u32 xlated_prog_len;
6431	__aligned_u64 jited_prog_insns;
6432	__aligned_u64 xlated_prog_insns;
6433	__u64 load_time; / ns since boottime /
6434	__u32 created_by_uid;
6435	__u32 nr_map_ids;
6436	__aligned_u64 map_ids;
6437	char name[BPF_OBJ_NAME_LEN];
6438	__u32 ifindex;
6439	__u32 gpl_compatible:`1`;
6440	__u32 :`31`; / alignment pad /
6441	__u64 netns_dev;
6442	__u64 netns_ino;
6443	__u32 nr_jited_ksyms;
6444	__u32 nr_jited_func_lens;
6445	__aligned_u64 jited_ksyms;
6446	__aligned_u64 jited_func_lens;
6447	__u32 btf_id;
6448	__u32 func_info_rec_size;
6449	__aligned_u64 func_info;
6450	__u32 nr_func_info;
6451	__u32 nr_line_info;
6452	__aligned_u64 line_info;
6453	__aligned_u64 jited_line_info;
6454	__u32 nr_jited_line_info;
6455	__u32 line_info_rec_size;
6456	__u32 jited_line_info_rec_size;
6457	__u32 nr_prog_tags;
6458	__aligned_u64 prog_tags;
6459	__u64 run_time_ns;
6460	__u64 run_cnt;
6461	__u64 recursion_misses;
6462	__u32 verified_insns;
6463	__u32 attach_btf_obj_id;
6464	__u32 attach_btf_id;
6465	} __attribute__((aligned(`8`)));
6466
6467	struct bpf_map_info {
6468	__u32 type;
6469	__u32 id;
6470	__u32 key_size;
6471	__u32 value_size;
6472	__u32 max_entries;
6473	__u32 map_flags;
6474	char name[BPF_OBJ_NAME_LEN];
6475	__u32 ifindex;
6476	__u32 btf_vmlinux_value_type_id;
6477	__u64 netns_dev;
6478	__u64 netns_ino;
6479	__u32 btf_id;
6480	__u32 btf_key_type_id;
6481	__u32 btf_value_type_id;
6482	__u32 :`32`; / alignment pad /
6483	__u64 map_extra;
6484	} __attribute__((aligned(`8`)));
6485
6486	struct bpf_btf_info {
6487	__aligned_u64 btf;
6488	__u32 btf_size;
6489	__u32 id;
6490	__aligned_u64 name;
6491	__u32 name_len;
6492	__u32 kernel_btf;
6493	} __attribute__((aligned(`8`)));
6494
6495	struct bpf_link_info {
6496	__u32 type;
6497	__u32 id;
6498	__u32 prog_id;
6499	union {
6500	struct {
6501	__aligned_u64 tp_name; / in/out: tp_name buffer ptr /
6502	__u32 tp_name_len; / in/out: tp_name buffer len /
6503	} raw_tracepoint;
6504	struct {
6505	__u32 attach_type;
6506	__u32 target_obj_id; / prog_id for PROG_EXT, otherwise btf object id /
6507	__u32 target_btf_id; / BTF type id inside the object /
6508	} tracing;
6509	struct {
6510	__u64 cgroup_id;
6511	__u32 attach_type;
6512	} cgroup;
6513	struct {
6514	__aligned_u64 target_name; / in/out: target_name buffer ptr /
6515	__u32 target_name_len; / in/out: target_name buffer len /
6516
6517	/ If the iter specific field is 32 bits, it can be put*
6518	* in the first or second union. Otherwise it should be
6519	* put in the second union.
6520	*/
6521	union {
6522	struct {
6523	__u32 map_id;
6524	} map;
6525	};
6526	union {
6527	struct {
6528	__u64 cgroup_id;
6529	__u32 order;
6530	} cgroup;
6531	struct {
6532	__u32 tid;
6533	__u32 pid;
6534	} task;
6535	};
6536	} iter;
6537	struct {
6538	__u32 netns_ino;
6539	__u32 attach_type;
6540	} netns;
6541	struct {
6542	__u32 ifindex;
6543	} xdp;
6544	struct {
6545	__u32 map_id;
6546	} struct_ops;
6547	struct {
6548	__u32 pf;
6549	__u32 hooknum;
6550	__s32 priority;
6551	__u32 flags;
6552	} netfilter;
6553	struct {
6554	__aligned_u64 addrs;
6555	__u32 count; / in/out: kprobe_multi function count /
6556	__u32 flags;
6557	__u64 missed;
6558	} kprobe_multi;
6559	struct {
6560	__u32 type; / enum bpf_perf_event_type /
6561	__u32 :`32`;
6562	union {
6563	struct {
6564	__aligned_u64 file_name; / in/out /
6565	__u32 name_len;
6566	__u32 offset; / offset from file_name /
6567	} uprobe; / BPF_PERF_EVENT_UPROBE, BPF_PERF_EVENT_URETPROBE /
6568	struct {
6569	__aligned_u64 func_name; / in/out /
6570	__u32 name_len;
6571	__u32 offset; / offset from func_name /
6572	__u64 addr;
6573	__u64 missed;
6574	} kprobe; / BPF_PERF_EVENT_KPROBE, BPF_PERF_EVENT_KRETPROBE /
6575	struct {
6576	__aligned_u64 tp_name; / in/out /
6577	__u32 name_len;
6578	} tracepoint; / BPF_PERF_EVENT_TRACEPOINT /
6579	struct {
6580	__u64 config;
6581	__u32 type;
6582	} event; / BPF_PERF_EVENT_EVENT /
6583	};
6584	} perf_event;
6585	struct {
6586	__u32 ifindex;
6587	__u32 attach_type;
6588	} tcx;
6589	struct {
6590	__u32 ifindex;
6591	__u32 attach_type;
6592	} netkit;
6593	};
6594	} __attribute__((aligned(`8`)));
6595
6596	/ User bpf_sock_addr struct to access socket fields and sockaddr struct passed*
6597	* by user and intended to be used by socket (e.g. to bind to, depends on
6598	* attach type).
6599	*/
6600	struct bpf_sock_addr {
6601	__u32 user_family; / Allows 4-byte read, but no write. /
6602	__u32 user_ip4; / Allows 1,2,4-byte read and 4-byte write.*
6603	* Stored in network byte order.
6604	*/
6605	__u32 user_ip6[`4`]; / Allows 1,2,4,8-byte read and 4,8-byte write.*
6606	* Stored in network byte order.
6607	*/
6608	__u32 user_port; / Allows 1,2,4-byte read and 4-byte write.*
6609	* Stored in network byte order
6610	*/
6611	__u32 family; / Allows 4-byte read, but no write /
6612	__u32 type; / Allows 4-byte read, but no write /
6613	__u32 protocol; / Allows 4-byte read, but no write /
6614	__u32 msg_src_ip4; / Allows 1,2,4-byte read and 4-byte write.*
6615	* Stored in network byte order.
6616	*/
6617	__u32 msg_src_ip6[`4`]; / Allows 1,2,4,8-byte read and 4,8-byte write.*
6618	* Stored in network byte order.
6619	*/
6620	__bpf_md_ptr(struct bpf_sock *, sk);
6621	};
6622
6623	/ User bpf_sock_ops struct to access socket values and specify request ops*
6624	* and their replies.
6625	* Some of this fields are in network (bigendian) byte order and may need
6626	* to be converted before use (bpf_ntohl() defined in samples/bpf/bpf_endian.h).
6627	* New fields can only be added at the end of this structure
6628	*/
6629	struct bpf_sock_ops {
6630	__u32 op;
6631	union {
6632	__u32 args[`4`]; / Optionally passed to bpf program /
6633	__u32 reply; / Returned by bpf program /
6634	__u32 replylong[`4`]; / Optionally returned by bpf prog /
6635	};
6636	__u32 family;
6637	__u32 remote_ip4; / Stored in network byte order /
6638	__u32 local_ip4; / Stored in network byte order /
6639	__u32 remote_ip6[`4`]; / Stored in network byte order /
6640	__u32 local_ip6[`4`]; / Stored in network byte order /
6641	__u32 remote_port; / Stored in network byte order /
6642	__u32 local_port; / stored in host byte order /
6643	__u32 is_fullsock; / Some TCP fields are only valid if*
6644	* there is a full socket. If not, the
6645	* fields read as zero.
6646	*/
6647	__u32 snd_cwnd;
6648	__u32 srtt_us; / Averaged RTT << 3 in usecs /
6649	__u32 bpf_sock_ops_cb_flags; / flags defined in uapi/linux/tcp.h /
6650	__u32 state;
6651	__u32 rtt_min;
6652	__u32 snd_ssthresh;
6653	__u32 rcv_nxt;
6654	__u32 snd_nxt;
6655	__u32 snd_una;
6656	__u32 mss_cache;
6657	__u32 ecn_flags;
6658	__u32 rate_delivered;
6659	__u32 rate_interval_us;
6660	__u32 packets_out;
6661	__u32 retrans_out;
6662	__u32 total_retrans;
6663	__u32 segs_in;
6664	__u32 data_segs_in;
6665	__u32 segs_out;
6666	__u32 data_segs_out;
6667	__u32 lost_out;
6668	__u32 sacked_out;
6669	__u32 sk_txhash;
6670	__u64 bytes_received;
6671	__u64 bytes_acked;
6672	__bpf_md_ptr(struct bpf_sock *, sk);
6673	/ [skb_data, skb_data_end) covers the whole TCP header.*
6674	*
6675	* BPF_SOCK_OPS_PARSE_HDR_OPT_CB: The packet received
6676	* BPF_SOCK_OPS_HDR_OPT_LEN_CB: Not useful because the
6677	* header has not been written.
6678	* BPF_SOCK_OPS_WRITE_HDR_OPT_CB: The header and options have
6679	* been written so far.
6680	* BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB: The SYNACK that concludes
6681	* the 3WHS.
6682	* BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: The ACK that concludes
6683	* the 3WHS.
6684	*
6685	* bpf_load_hdr_opt() can also be used to read a particular option.
6686	*/
6687	__bpf_md_ptr(void *, skb_data);
6688	__bpf_md_ptr(void *, skb_data_end);
6689	__u32 skb_len; / The total length of a packet.*
6690	* It includes the header, options,
6691	* and payload.
6692	*/
6693	__u32 skb_tcp_flags; / tcp_flags of the header. It provides*
6694	* an easy way to check for tcp_flags
6695	* without parsing skb_data.
6696	*
6697	* In particular, the skb_tcp_flags
6698	* will still be available in
6699	* BPF_SOCK_OPS_HDR_OPT_LEN even though
6700	* the outgoing header has not
6701	* been written yet.
6702	*/
6703	__u64 skb_hwtstamp;
6704	};
6705
6706	/ Definitions for bpf_sock_ops_cb_flags /
6707	enum {
6708	BPF_SOCK_OPS_RTO_CB_FLAG = (`1`<<`0`),
6709	BPF_SOCK_OPS_RETRANS_CB_FLAG = (`1`<<`1`),
6710	BPF_SOCK_OPS_STATE_CB_FLAG = (`1`<<`2`),
6711	BPF_SOCK_OPS_RTT_CB_FLAG = (`1`<<`3`),
6712	/ Call bpf for all received TCP headers. The bpf prog will be*
6713	* called under sock_ops->op == BPF_SOCK_OPS_PARSE_HDR_OPT_CB
6714	*
6715	* Please refer to the comment in BPF_SOCK_OPS_PARSE_HDR_OPT_CB
6716	* for the header option related helpers that will be useful
6717	* to the bpf programs.
6718	*
6719	* It could be used at the client/active side (i.e. connect() side)
6720	* when the server told it that the server was in syncookie
6721	* mode and required the active side to resend the bpf-written
6722	* options. The active side can keep writing the bpf-options until
6723	* it received a valid packet from the server side to confirm
6724	* the earlier packet (and options) has been received. The later
6725	* example patch is using it like this at the active side when the
6726	* server is in syncookie mode.
6727	*
6728	* The bpf prog will usually turn this off in the common cases.
6729	*/
6730	BPF_SOCK_OPS_PARSE_ALL_HDR_OPT_CB_FLAG = (`1`<<`4`),
6731	/ Call bpf when kernel has received a header option that*
6732	* the kernel cannot handle. The bpf prog will be called under
6733	* sock_ops->op == BPF_SOCK_OPS_PARSE_HDR_OPT_CB.
6734	*
6735	* Please refer to the comment in BPF_SOCK_OPS_PARSE_HDR_OPT_CB
6736	* for the header option related helpers that will be useful
6737	* to the bpf programs.
6738	*/
6739	BPF_SOCK_OPS_PARSE_UNKNOWN_HDR_OPT_CB_FLAG = (`1`<<`5`),
6740	/ Call bpf when the kernel is writing header options for the*
6741	* outgoing packet. The bpf prog will first be called
6742	* to reserve space in a skb under
6743	* sock_ops->op == BPF_SOCK_OPS_HDR_OPT_LEN_CB. Then
6744	* the bpf prog will be called to write the header option(s)
6745	* under sock_ops->op == BPF_SOCK_OPS_WRITE_HDR_OPT_CB.
6746	*
6747	* Please refer to the comment in BPF_SOCK_OPS_HDR_OPT_LEN_CB
6748	* and BPF_SOCK_OPS_WRITE_HDR_OPT_CB for the header option
6749	* related helpers that will be useful to the bpf programs.
6750	*
6751	* The kernel gets its chance to reserve space and write
6752	* options first before the BPF program does.
6753	*/
6754	BPF_SOCK_OPS_WRITE_HDR_OPT_CB_FLAG = (`1`<<`6`),
6755	/ Mask of all currently supported cb flags /
6756	BPF_SOCK_OPS_ALL_CB_FLAGS = `0x7F`,
6757	};
6758
6759	/ List of known BPF sock_ops operators.*
6760	* New entries can only be added at the end
6761	*/
6762	enum {
6763	BPF_SOCK_OPS_VOID,
6764	BPF_SOCK_OPS_TIMEOUT_INIT, / Should return SYN-RTO value to use or*
6765	* -1 if default value should be used
6766	*/
6767	BPF_SOCK_OPS_RWND_INIT, / Should return initial advertized*
6768	* window (in packets) or -1 if default
6769	* value should be used
6770	*/
6771	BPF_SOCK_OPS_TCP_CONNECT_CB, / Calls BPF program right before an*
6772	* active connection is initialized
6773	*/
6774	BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB, / Calls BPF program when an*
6775	* active connection is
6776	* established
6777	*/
6778	BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB, / Calls BPF program when a*
6779	* passive connection is
6780	* established
6781	*/
6782	BPF_SOCK_OPS_NEEDS_ECN, / If connection's congestion control*
6783	* needs ECN
6784	*/
6785	BPF_SOCK_OPS_BASE_RTT, / Get base RTT. The correct value is*
6786	* based on the path and may be
6787	* dependent on the congestion control
6788	* algorithm. In general it indicates
6789	* a congestion threshold. RTTs above
6790	* this indicate congestion
6791	*/
6792	BPF_SOCK_OPS_RTO_CB, / Called when an RTO has triggered.*
6793	* Arg1: value of icsk_retransmits
6794	* Arg2: value of icsk_rto
6795	* Arg3: whether RTO has expired
6796	*/
6797	BPF_SOCK_OPS_RETRANS_CB, / Called when skb is retransmitted.*
6798	* Arg1: sequence number of 1st byte
6799	* Arg2: # segments
6800	* Arg3: return value of
6801	* tcp_transmit_skb (0 => success)
6802	*/
6803	BPF_SOCK_OPS_STATE_CB, / Called when TCP changes state.*
6804	* Arg1: old_state
6805	* Arg2: new_state
6806	*/
6807	BPF_SOCK_OPS_TCP_LISTEN_CB, / Called on listen(2), right after*
6808	* socket transition to LISTEN state.
6809	*/
6810	BPF_SOCK_OPS_RTT_CB, / Called on every RTT.*
6811	*/
6812	BPF_SOCK_OPS_PARSE_HDR_OPT_CB, / Parse the header option.*
6813	* It will be called to handle
6814	* the packets received at
6815	* an already established
6816	* connection.
6817	*
6818	* sock_ops->skb_data:
6819	* Referring to the received skb.
6820	* It covers the TCP header only.
6821	*
6822	* bpf_load_hdr_opt() can also
6823	* be used to search for a
6824	* particular option.
6825	*/
6826	BPF_SOCK_OPS_HDR_OPT_LEN_CB, / Reserve space for writing the*
6827	* header option later in
6828	* BPF_SOCK_OPS_WRITE_HDR_OPT_CB.
6829	* Arg1: bool want_cookie. (in
6830	* writing SYNACK only)
6831	*
6832	* sock_ops->skb_data:
6833	* Not available because no header has
6834	* been written yet.
6835	*
6836	* sock_ops->skb_tcp_flags:
6837	* The tcp_flags of the
6838	* outgoing skb. (e.g. SYN, ACK, FIN).
6839	*
6840	* bpf_reserve_hdr_opt() should
6841	* be used to reserve space.
6842	*/
6843	BPF_SOCK_OPS_WRITE_HDR_OPT_CB, / Write the header options*
6844	* Arg1: bool want_cookie. (in
6845	* writing SYNACK only)
6846	*
6847	* sock_ops->skb_data:
6848	* Referring to the outgoing skb.
6849	* It covers the TCP header
6850	* that has already been written
6851	* by the kernel and the
6852	* earlier bpf-progs.
6853	*
6854	* sock_ops->skb_tcp_flags:
6855	* The tcp_flags of the outgoing
6856	* skb. (e.g. SYN, ACK, FIN).
6857	*
6858	* bpf_store_hdr_opt() should
6859	* be used to write the
6860	* option.
6861	*
6862	* bpf_load_hdr_opt() can also
6863	* be used to search for a
6864	* particular option that
6865	* has already been written
6866	* by the kernel or the
6867	* earlier bpf-progs.
6868	*/
6869	};
6870
6871	/ List of TCP states. There is a build check in net/ipv4/tcp.c to detect*
6872	* changes between the TCP and BPF versions. Ideally this should never happen.
6873	* If it does, we need to add code to convert them before calling
6874	* the BPF sock_ops function.
6875	*/
6876	enum {
6877	BPF_TCP_ESTABLISHED = `1`,
6878	BPF_TCP_SYN_SENT,
6879	BPF_TCP_SYN_RECV,
6880	BPF_TCP_FIN_WAIT1,
6881	BPF_TCP_FIN_WAIT2,
6882	BPF_TCP_TIME_WAIT,
6883	BPF_TCP_CLOSE,
6884	BPF_TCP_CLOSE_WAIT,
6885	BPF_TCP_LAST_ACK,
6886	BPF_TCP_LISTEN,
6887	BPF_TCP_CLOSING, / Now a valid state /
6888	BPF_TCP_NEW_SYN_RECV,
6889
6890	BPF_TCP_MAX_STATES / Leave at the end! /
6891	};
6892
6893	enum {
6894	TCP_BPF_IW = `1001`, / Set TCP initial congestion window /
6895	TCP_BPF_SNDCWND_CLAMP = `1002`, / Set sndcwnd_clamp /
6896	TCP_BPF_DELACK_MAX = `1003`, / Max delay ack in usecs /
6897	TCP_BPF_RTO_MIN = `1004`, / Min delay ack in usecs /
6898	/ Copy the SYN pkt to optval*
6899	*
6900	* BPF_PROG_TYPE_SOCK_OPS only. It is similar to the
6901	* bpf_getsockopt(TCP_SAVED_SYN) but it does not limit
6902	* to only getting from the saved_syn. It can either get the
6903	* syn packet from:
6904	*
6905	* 1. the just-received SYN packet (only available when writing the
6906	* SYNACK). It will be useful when it is not necessary to
6907	* save the SYN packet for latter use. It is also the only way
6908	* to get the SYN during syncookie mode because the syn
6909	* packet cannot be saved during syncookie.
6910	*
6911	* OR
6912	*
6913	* 2. the earlier saved syn which was done by
6914	* bpf_setsockopt(TCP_SAVE_SYN).
6915	*
6916	* The bpf_getsockopt(TCP_BPF_SYN*) option will hide where the
6917	* SYN packet is obtained.
6918	*
6919	* If the bpf-prog does not need the IP[46] header, the
6920	* bpf-prog can avoid parsing the IP header by using
6921	* TCP_BPF_SYN. Otherwise, the bpf-prog can get both
6922	* IP[46] and TCP header by using TCP_BPF_SYN_IP.
6923	*
6924	* >0: Total number of bytes copied
6925	* -ENOSPC: Not enough space in optval. Only optlen number of
6926	* bytes is copied.
6927	* -ENOENT: The SYN skb is not available now and the earlier SYN pkt
6928	* is not saved by setsockopt(TCP_SAVE_SYN).
6929	*/
6930	TCP_BPF_SYN = `1005`, / Copy the TCP header /
6931	TCP_BPF_SYN_IP = `1006`, / Copy the IP[46] and TCP header /
6932	TCP_BPF_SYN_MAC = `1007`, / Copy the MAC, IP[46], and TCP header /
6933	};
6934
6935	enum {
6936	BPF_LOAD_HDR_OPT_TCP_SYN = (`1ULL` << `0`),
6937	};
6938
6939	/ args[0] value during BPF_SOCK_OPS_HDR_OPT_LEN_CB and*
6940	* BPF_SOCK_OPS_WRITE_HDR_OPT_CB.
6941	*/
6942	enum {
6943	BPF_WRITE_HDR_TCP_CURRENT_MSS = `1`, / Kernel is finding the*
6944	* total option spaces
6945	* required for an established
6946	* sk in order to calculate the
6947	* MSS. No skb is actually
6948	* sent.
6949	*/
6950	BPF_WRITE_HDR_TCP_SYNACK_COOKIE = `2`, / Kernel is in syncookie mode*
6951	* when sending a SYN.
6952	*/
6953	};
6954
6955	struct bpf_perf_event_value {
6956	__u64 counter;
6957	__u64 enabled;
6958	__u64 running;
6959	};
6960
6961	enum {
6962	BPF_DEVCG_ACC_MKNOD = (`1ULL` << `0`),
6963	BPF_DEVCG_ACC_READ = (`1ULL` << `1`),
6964	BPF_DEVCG_ACC_WRITE = (`1ULL` << `2`),
6965	};
6966
6967	enum {
6968	BPF_DEVCG_DEV_BLOCK = (`1ULL` << `0`),
6969	BPF_DEVCG_DEV_CHAR = (`1ULL` << `1`),
6970	};
6971
6972	struct bpf_cgroup_dev_ctx {
6973	/ access_type encoded as (BPF_DEVCG_ACC_* << 16) \| BPF_DEVCG_DEV_* /
6974	__u32 access_type;
6975	__u32 major;
6976	__u32 minor;
6977	};
6978
6979	struct bpf_raw_tracepoint_args {
6980	__u64 args[`0`];
6981	};
6982
6983	/ DIRECT: Skip the FIB rules and go to FIB table associated with device*
6984	* OUTPUT: Do lookup from egress perspective; default is ingress
6985	*/
6986	enum {
6987	BPF_FIB_LOOKUP_DIRECT = (`1U` << `0`),
6988	BPF_FIB_LOOKUP_OUTPUT = (`1U` << `1`),
6989	BPF_FIB_LOOKUP_SKIP_NEIGH = (`1U` << `2`),
6990	BPF_FIB_LOOKUP_TBID = (`1U` << `3`),
6991	BPF_FIB_LOOKUP_SRC = (`1U` << `4`),
6992	};
6993
6994	enum {
6995	BPF_FIB_LKUP_RET_SUCCESS, / lookup successful /
6996	BPF_FIB_LKUP_RET_BLACKHOLE, / dest is blackholed; can be dropped /
6997	BPF_FIB_LKUP_RET_UNREACHABLE, / dest is unreachable; can be dropped /
6998	BPF_FIB_LKUP_RET_PROHIBIT, / dest not allowed; can be dropped /
6999	BPF_FIB_LKUP_RET_NOT_FWDED, / packet is not forwarded /
7000	BPF_FIB_LKUP_RET_FWD_DISABLED, / fwding is not enabled on ingress /
7001	BPF_FIB_LKUP_RET_UNSUPP_LWT, / fwd requires encapsulation /
7002	BPF_FIB_LKUP_RET_NO_NEIGH, / no neighbor entry for nh /
7003	BPF_FIB_LKUP_RET_FRAG_NEEDED, / fragmentation required to fwd /
7004	BPF_FIB_LKUP_RET_NO_SRC_ADDR, / failed to derive IP src addr /
7005	};
7006
7007	struct bpf_fib_lookup {
7008	/ input: network family for lookup (AF_INET, AF_INET6)*
7009	* output: network family of egress nexthop
7010	*/
7011	__u8 family;
7012
7013	/ set if lookup is to consider L4 data - e.g., FIB rules /
7014	__u8 l4_protocol;
7015	__be16 sport;
7016	__be16 dport;
7017
7018	union { / used for MTU check /
7019	/ input to lookup /
7020	__u16 tot_len; / L3 length from network hdr (iph->tot_len) /
7021
7022	/ output: MTU value /
7023	__u16 mtu_result;
7024	};
7025	/ input: L3 device index for lookup*
7026	* output: device index from FIB lookup
7027	*/
7028	__u32 ifindex;
7029
7030	union {
7031	/ inputs to lookup /
7032	__u8 tos; / AF_INET /
7033	__be32 flowinfo; / AF_INET6, flow_label + priority /
7034
7035	/ output: metric of fib result (IPv4/IPv6 only) /
7036	__u32 rt_metric;
7037	};
7038
7039	/ input: source address to consider for lookup*
7040	* output: source address result from lookup
7041	*/
7042	union {
7043	__be32 ipv4_src;
7044	__u32 ipv6_src[`4`]; / in6_addr; network order /
7045	};
7046
7047	/ input to bpf_fib_lookup, ipv{4,6}_dst is destination address in*
7048	* network header. output: bpf_fib_lookup sets to gateway address
7049	* if FIB lookup returns gateway route
7050	*/
7051	union {
7052	__be32 ipv4_dst;
7053	__u32 ipv6_dst[`4`]; / in6_addr; network order /
7054	};
7055
7056	union {
7057	struct {
7058	/ output /
7059	__be16 h_vlan_proto;
7060	__be16 h_vlan_TCI;
7061	};
7062	/ input: when accompanied with the*
7063	* 'BPF_FIB_LOOKUP_DIRECT \| BPF_FIB_LOOKUP_TBID` flags, a
7064	* specific routing table to use for the fib lookup.
7065	*/
7066	__u32 tbid;
7067	};
7068
7069	__u8 smac[`6`]; / ETH_ALEN /
7070	__u8 dmac[`6`]; / ETH_ALEN /
7071	};
7072
7073	struct bpf_redir_neigh {
7074	/ network family for lookup (AF_INET, AF_INET6) /
7075	__u32 nh_family;
7076	/ network address of nexthop; skips fib lookup to find gateway /
7077	union {
7078	__be32 ipv4_nh;
7079	__u32 ipv6_nh[`4`]; / in6_addr; network order /
7080	};
7081	};
7082
7083	/ bpf_check_mtu flags/
7084	enum bpf_check_mtu_flags {
7085	BPF_MTU_CHK_SEGS = (`1U` << `0`),
7086	};
7087
7088	enum bpf_check_mtu_ret {
7089	BPF_MTU_CHK_RET_SUCCESS, / check and lookup successful /
7090	BPF_MTU_CHK_RET_FRAG_NEEDED, / fragmentation required to fwd /
7091	BPF_MTU_CHK_RET_SEGS_TOOBIG, / GSO re-segmentation needed to fwd /
7092	};
7093
7094	enum bpf_task_fd_type {
7095	BPF_FD_TYPE_RAW_TRACEPOINT, / tp name /
7096	BPF_FD_TYPE_TRACEPOINT, / tp name /
7097	BPF_FD_TYPE_KPROBE, / (symbol + offset) or addr /
7098	BPF_FD_TYPE_KRETPROBE, / (symbol + offset) or addr /
7099	BPF_FD_TYPE_UPROBE, / filename + offset /
7100	BPF_FD_TYPE_URETPROBE, / filename + offset /
7101	};
7102
7103	enum {
7104	BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG = (`1U` << `0`),
7105	BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL = (`1U` << `1`),
7106	BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP = (`1U` << `2`),
7107	};
7108
7109	struct bpf_flow_keys {
7110	__u16 nhoff;
7111	__u16 thoff;
7112	__u16 addr_proto; / ETH_P_* of valid addrs /
7113	__u8 is_frag;
7114	__u8 is_first_frag;
7115	__u8 is_encap;
7116	__u8 ip_proto;
7117	__be16 n_proto;
7118	__be16 sport;
7119	__be16 dport;
7120	union {
7121	struct {
7122	__be32 ipv4_src;
7123	__be32 ipv4_dst;
7124	};
7125	struct {
7126	__u32 ipv6_src[`4`]; / in6_addr; network order /
7127	__u32 ipv6_dst[`4`]; / in6_addr; network order /
7128	};
7129	};
7130	__u32 flags;
7131	__be32 flow_label;
7132	};
7133
7134	struct bpf_func_info {
7135	__u32 insn_off;
7136	__u32 type_id;
7137	};
7138
7139	#define BPF_LINE_INFO_LINE_NUM(line_col) ((line_col) >> 10)
7140	#define BPF_LINE_INFO_LINE_COL(line_col) ((line_col) & 0x3ff)
7141
7142	struct bpf_line_info {
7143	__u32 insn_off;
7144	__u32 file_name_off;
7145	__u32 line_off;
7146	__u32 line_col;
7147	};
7148
7149	struct bpf_spin_lock {
7150	__u32 val;
7151	};
7152
7153	struct bpf_timer {
7154	__u64 :`64`;
7155	__u64 :`64`;
7156	} __attribute__((aligned(`8`)));
7157
7158	struct bpf_dynptr {
7159	__u64 :`64`;
7160	__u64 :`64`;
7161	} __attribute__((aligned(`8`)));
7162
7163	struct bpf_list_head {
7164	__u64 :`64`;
7165	__u64 :`64`;
7166	} __attribute__((aligned(`8`)));
7167
7168	struct bpf_list_node {
7169	__u64 :`64`;
7170	__u64 :`64`;
7171	__u64 :`64`;
7172	} __attribute__((aligned(`8`)));
7173
7174	struct bpf_rb_root {
7175	__u64 :`64`;
7176	__u64 :`64`;
7177	} __attribute__((aligned(`8`)));
7178
7179	struct bpf_rb_node {
7180	__u64 :`64`;
7181	__u64 :`64`;
7182	__u64 :`64`;
7183	__u64 :`64`;
7184	} __attribute__((aligned(`8`)));
7185
7186	struct bpf_refcount {
7187	__u32 :`32`;
7188	} __attribute__((aligned(`4`)));
7189
7190	struct bpf_sysctl {
7191	__u32 write; / Sysctl is being read (= 0) or written (= 1).*
7192	* Allows 1,2,4-byte read, but no write.
7193	*/
7194	__u32 file_pos; / Sysctl file position to read from, write to.*
7195	* Allows 1,2,4-byte read an 4-byte write.
7196	*/
7197	};
7198
7199	struct bpf_sockopt {
7200	__bpf_md_ptr(struct bpf_sock *, sk);
7201	__bpf_md_ptr(void *, optval);
7202	__bpf_md_ptr(void *, optval_end);
7203
7204	__s32 level;
7205	__s32 optname;
7206	__s32 optlen;
7207	__s32 retval;
7208	};
7209
7210	struct bpf_pidns_info {
7211	__u32 pid;
7212	__u32 tgid;
7213	};
7214
7215	/ User accessible data for SK_LOOKUP programs. Add new fields at the end. /
7216	struct bpf_sk_lookup {
7217	union {
7218	__bpf_md_ptr(struct bpf_sock , sk); /* Selected socket /
7219	__u64 cookie; / Non-zero if socket was selected in PROG_TEST_RUN /
7220	};
7221
7222	__u32 family; / Protocol family (AF_INET, AF_INET6) /
7223	__u32 protocol; / IP protocol (IPPROTO_TCP, IPPROTO_UDP) /
7224	__u32 remote_ip4; / Network byte order /
7225	__u32 remote_ip6[`4`]; / Network byte order /
7226	__be16 remote_port; / Network byte order /
7227	__u16 :`16`; / Zero padding /
7228	__u32 local_ip4; / Network byte order /
7229	__u32 local_ip6[`4`]; / Network byte order /
7230	__u32 local_port; / Host byte order /
7231	__u32 ingress_ifindex; / The arriving interface. Determined by inet_iif. /
7232	};
7233
7234	/*
7235	* struct btf_ptr is used for typed pointer representation; the
7236	* type id is used to render the pointer data as the appropriate type
7237	* via the bpf_snprintf_btf() helper described above. A flags field -
7238	* potentially to specify additional details about the BTF pointer
7239	* (rather than its mode of display) - is included for future use.
7240	* Display flags - BTF_F_* - are passed to bpf_snprintf_btf separately.
7241	*/
7242	struct btf_ptr {
7243	void *ptr;
7244	__u32 type_id;
7245	__u32 flags; / BTF ptr flags; unused at present. /
7246	};
7247
7248	/*
7249	* Flags to control bpf_snprintf_btf() behaviour.
7250	* - BTF_F_COMPACT: no formatting around type information
7251	* - BTF_F_NONAME: no struct/union member names/types
7252	* - BTF_F_PTR_RAW: show raw (unobfuscated) pointer values;
7253	* equivalent to %px.
7254	* - BTF_F_ZERO: show zero-valued struct/union members; they
7255	* are not displayed by default
7256	*/
7257	enum {
7258	BTF_F_COMPACT = (`1ULL` << `0`),
7259	BTF_F_NONAME = (`1ULL` << `1`),
7260	BTF_F_PTR_RAW = (`1ULL` << `2`),
7261	BTF_F_ZERO = (`1ULL` << `3`),
7262	};
7263
7264	/ bpf_core_relo_kind encodes which aspect of captured field/type/enum value*
7265	* has to be adjusted by relocations. It is emitted by llvm and passed to
7266	* libbpf and later to the kernel.
7267	*/
7268	enum bpf_core_relo_kind {
7269	BPF_CORE_FIELD_BYTE_OFFSET = `0`, / field byte offset /
7270	BPF_CORE_FIELD_BYTE_SIZE = `1`, / field size in bytes /
7271	BPF_CORE_FIELD_EXISTS = `2`, / field existence in target kernel /
7272	BPF_CORE_FIELD_SIGNED = `3`, / field signedness (0 - unsigned, 1 - signed) /
7273	BPF_CORE_FIELD_LSHIFT_U64 = `4`, / bitfield-specific left bitshift /
7274	BPF_CORE_FIELD_RSHIFT_U64 = `5`, / bitfield-specific right bitshift /
7275	BPF_CORE_TYPE_ID_LOCAL = `6`, / type ID in local BPF object /
7276	BPF_CORE_TYPE_ID_TARGET = `7`, / type ID in target kernel /
7277	BPF_CORE_TYPE_EXISTS = `8`, / type existence in target kernel /
7278	BPF_CORE_TYPE_SIZE = `9`, / type size in bytes /
7279	BPF_CORE_ENUMVAL_EXISTS = `10`, / enum value existence in target kernel /
7280	BPF_CORE_ENUMVAL_VALUE = `11`, / enum value integer value /
7281	BPF_CORE_TYPE_MATCHES = `12`, / type match in target kernel /
7282	};
7283
7284	/*
7285	* "struct bpf_core_relo" is used to pass relocation data form LLVM to libbpf
7286	* and from libbpf to the kernel.
7287	*
7288	* CO-RE relocation captures the following data:
7289	* - insn_off - instruction offset (in bytes) within a BPF program that needs
7290	* its insn->imm field to be relocated with actual field info;
7291	* - type_id - BTF type ID of the "root" (containing) entity of a relocatable
7292	* type or field;
7293	* - access_str_off - offset into corresponding .BTF string section. String
7294	* interpretation depends on specific relocation kind:
7295	* - for field-based relocations, string encodes an accessed field using
7296	* a sequence of field and array indices, separated by colon (:). It's
7297	* conceptually very close to LLVM's getelementptr ([0]) instruction's
7298	* arguments for identifying offset to a field.
7299	* - for type-based relocations, strings is expected to be just "0";
7300	* - for enum value-based relocations, string contains an index of enum
7301	* value within its enum type;
7302	* - kind - one of enum bpf_core_relo_kind;
7303	*
7304	* Example:
7305	* struct sample {
7306	* int a;
7307	* struct {
7308	* int b[10];
7309	* };
7310	* };
7311	*
7312	* struct sample *s = ...;
7313	* int *x = &s->a; // encoded as "0:0" (a is field #0)
7314	* int *y = &s->b[5]; // encoded as "0:1:0:5" (anon struct is field #1,
7315	* // b is field #0 inside anon struct, accessing elem #5)
7316	* int *z = &s[10]->b; // encoded as "10:1" (ptr is used as an array)
7317	*
7318	* type_id for all relocs in this example will capture BTF type id of
7319	* `struct sample`.
7320	*
7321	* Such relocation is emitted when using __builtin_preserve_access_index()
7322	* Clang built-in, passing expression that captures field address, e.g.:
7323	*
7324	* bpf_probe_read(&dst, sizeof(dst),
7325	* __builtin_preserve_access_index(&src->a.b.c));
7326	*
7327	* In this case Clang will emit field relocation recording necessary data to
7328	* be able to find offset of embedded `a.b.c` field within `src` struct.
7329	*
7330	* [0] https://llvm.org/docs/LangRef.html#getelementptr-instruction
7331	*/
7332	struct bpf_core_relo {
7333	__u32 insn_off;
7334	__u32 type_id;
7335	__u32 access_str_off;
7336	enum bpf_core_relo_kind kind;
7337	};
7338
7339	/*
7340	* Flags to control bpf_timer_start() behaviour.
7341	* - BPF_F_TIMER_ABS: Timeout passed is absolute time, by default it is
7342	* relative to current time.
7343	* - BPF_F_TIMER_CPU_PIN: Timer will be pinned to the CPU of the caller.
7344	*/
7345	enum {
7346	BPF_F_TIMER_ABS = (`1ULL` << `0`),
7347	BPF_F_TIMER_CPU_PIN = (`1ULL` << `1`),
7348	};
7349
7350	/ BPF numbers iterator state /
7351	struct bpf_iter_num {
7352	/ opaque iterator state; having __u64 here allows to preserve correct*
7353	* alignment requirements in vmlinux.h, generated from BTF
7354	*/
7355	__u64 __opaque[`1`];
7356	} __attribute__((aligned(`8`)));
7357
7358	#endif /* _UAPI__LINUX_BPF_H__ */
7359

source code of linux/include/uapi/linux/bpf.h