skbuff.h source code [linux/include/linux/skbuff.h]

1	/ SPDX-License-Identifier: GPL-2.0-or-later /
2	/*
3	* Definitions for the 'struct sk_buff' memory handlers.
4	*
5	* Authors:
6	* Alan Cox, <gw4pts@gw4pts.ampr.org>
7	* Florian La Roche, <rzsfl@rz.uni-sb.de>
8	*/
9
10	#ifndef _LINUX_SKBUFF_H
11	#define _LINUX_SKBUFF_H
12
13	#include <linux/kernel.h>
14	#include <linux/compiler.h>
15	#include <linux/time.h>
16	#include <linux/bug.h>
17	#include <linux/bvec.h>
18	#include <linux/cache.h>
19	#include <linux/rbtree.h>
20	#include <linux/socket.h>
21	#include <linux/refcount.h>
22
23	#include <linux/atomic.h>
24	#include <asm/types.h>
25	#include <linux/spinlock.h>
26	#include <linux/net.h>
27	#include <linux/textsearch.h>
28	#include <net/checksum.h>
29	#include <linux/rcupdate.h>
30	#include <linux/hrtimer.h>
31	#include <linux/dma-mapping.h>
32	#include <linux/netdev_features.h>
33	#include <linux/sched.h>
34	#include <linux/sched/clock.h>
35	#include <net/flow_dissector.h>
36	#include <linux/splice.h>
37	#include <linux/in6.h>
38	#include <linux/if_packet.h>
39	#include <linux/llist.h>
40	#include <net/flow.h>
41	#include <net/page_pool.h>
42	#if IS_ENABLED(CONFIG_NF_CONNTRACK)
43	#include <linux/netfilter/nf_conntrack_common.h>
44	#endif
45	#include <net/net_debug.h>
46	#include <net/dropreason.h>
47
48	/**
49	* DOC: skb checksums
50	*
51	* The interface for checksum offload between the stack and networking drivers
52	* is as follows...
53	*
54	* IP checksum related features
55	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
56	*
57	* Drivers advertise checksum offload capabilities in the features of a device.
58	* From the stack's point of view these are capabilities offered by the driver.
59	* A driver typically only advertises features that it is capable of offloading
60	* to its device.
61	*
62	* .. flat-table:: Checksum related device features
63	* :widths: 1 10
64	*
65	* * - %NETIF_F_HW_CSUM
66	* - The driver (or its device) is able to compute one
67	* IP (one's complement) checksum for any combination
68	* of protocols or protocol layering. The checksum is
69	* computed and set in a packet per the CHECKSUM_PARTIAL
70	* interface (see below).
71	*
72	* * - %NETIF_F_IP_CSUM
73	* - Driver (device) is only able to checksum plain
74	* TCP or UDP packets over IPv4. These are specifically
75	* unencapsulated packets of the form IPv4\|TCP or
76	* IPv4\|UDP where the Protocol field in the IPv4 header
77	* is TCP or UDP. The IPv4 header may contain IP options.
78	* This feature cannot be set in features for a device
79	* with NETIF_F_HW_CSUM also set. This feature is being
80	* DEPRECATED (see below).
81	*
82	* * - %NETIF_F_IPV6_CSUM
83	* - Driver (device) is only able to checksum plain
84	* TCP or UDP packets over IPv6. These are specifically
85	* unencapsulated packets of the form IPv6\|TCP or
86	* IPv6\|UDP where the Next Header field in the IPv6
87	* header is either TCP or UDP. IPv6 extension headers
88	* are not supported with this feature. This feature
89	* cannot be set in features for a device with
90	* NETIF_F_HW_CSUM also set. This feature is being
91	* DEPRECATED (see below).
92	*
93	* * - %NETIF_F_RXCSUM
94	* - Driver (device) performs receive checksum offload.
95	* This flag is only used to disable the RX checksum
96	* feature for a device. The stack will accept receive
97	* checksum indication in packets received on a device
98	* regardless of whether NETIF_F_RXCSUM is set.
99	*
100	* Checksumming of received packets by device
101	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
102	*
103	* Indication of checksum verification is set in &sk_buff.ip_summed.
104	* Possible values are:
105	*
106	* - %CHECKSUM_NONE
107	*
108	* Device did not checksum this packet e.g. due to lack of capabilities.
109	* The packet contains full (though not verified) checksum in packet but
110	* not in skb->csum. Thus, skb->csum is undefined in this case.
111	*
112	* - %CHECKSUM_UNNECESSARY
113	*
114	* The hardware you're dealing with doesn't calculate the full checksum
115	* (as in %CHECKSUM_COMPLETE), but it does parse headers and verify checksums
116	* for specific protocols. For such packets it will set %CHECKSUM_UNNECESSARY
117	* if their checksums are okay. &sk_buff.csum is still undefined in this case
118	* though. A driver or device must never modify the checksum field in the
119	* packet even if checksum is verified.
120	*
121	* %CHECKSUM_UNNECESSARY is applicable to following protocols:
122	*
123	* - TCP: IPv6 and IPv4.
124	* - UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
125	* zero UDP checksum for either IPv4 or IPv6, the networking stack
126	* may perform further validation in this case.
127	* - GRE: only if the checksum is present in the header.
128	* - SCTP: indicates the CRC in SCTP header has been validated.
129	* - FCOE: indicates the CRC in FC frame has been validated.
130	*
131	* &sk_buff.csum_level indicates the number of consecutive checksums found in
132	* the packet minus one that have been verified as %CHECKSUM_UNNECESSARY.
133	* For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
134	* and a device is able to verify the checksums for UDP (possibly zero),
135	* GRE (checksum flag is set) and TCP, &sk_buff.csum_level would be set to
136	* two. If the device were only able to verify the UDP checksum and not
137	* GRE, either because it doesn't support GRE checksum or because GRE
138	* checksum is bad, skb->csum_level would be set to zero (TCP checksum is
139	* not considered in this case).
140	*
141	* - %CHECKSUM_COMPLETE
142	*
143	* This is the most generic way. The device supplied checksum of the _whole_
144	* packet as seen by netif_rx() and fills in &sk_buff.csum. This means the
145	* hardware doesn't need to parse L3/L4 headers to implement this.
146	*
147	* Notes:
148	*
149	* - Even if device supports only some protocols, but is able to produce
150	* skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
151	* - CHECKSUM_COMPLETE is not applicable to SCTP and FCoE protocols.
152	*
153	* - %CHECKSUM_PARTIAL
154	*
155	* A checksum is set up to be offloaded to a device as described in the
156	* output description for CHECKSUM_PARTIAL. This may occur on a packet
157	* received directly from another Linux OS, e.g., a virtualized Linux kernel
158	* on the same host, or it may be set in the input path in GRO or remote
159	* checksum offload. For the purposes of checksum verification, the checksum
160	* referred to by skb->csum_start + skb->csum_offset and any preceding
161	* checksums in the packet are considered verified. Any checksums in the
162	* packet that are after the checksum being offloaded are not considered to
163	* be verified.
164	*
165	* Checksumming on transmit for non-GSO
166	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
167	*
168	* The stack requests checksum offload in the &sk_buff.ip_summed for a packet.
169	* Values are:
170	*
171	* - %CHECKSUM_PARTIAL
172	*
173	* The driver is required to checksum the packet as seen by hard_start_xmit()
174	* from &sk_buff.csum_start up to the end, and to record/write the checksum at
175	* offset &sk_buff.csum_start + &sk_buff.csum_offset.
176	* A driver may verify that the
177	* csum_start and csum_offset values are valid values given the length and
178	* offset of the packet, but it should not attempt to validate that the
179	* checksum refers to a legitimate transport layer checksum -- it is the
180	* purview of the stack to validate that csum_start and csum_offset are set
181	* correctly.
182	*
183	* When the stack requests checksum offload for a packet, the driver MUST
184	* ensure that the checksum is set correctly. A driver can either offload the
185	* checksum calculation to the device, or call skb_checksum_help (in the case
186	* that the device does not support offload for a particular checksum).
187	*
188	* %NETIF_F_IP_CSUM and %NETIF_F_IPV6_CSUM are being deprecated in favor of
189	* %NETIF_F_HW_CSUM. New devices should use %NETIF_F_HW_CSUM to indicate
190	* checksum offload capability.
191	* skb_csum_hwoffload_help() can be called to resolve %CHECKSUM_PARTIAL based
192	* on network device checksumming capabilities: if a packet does not match
193	* them, skb_checksum_help() or skb_crc32c_help() (depending on the value of
194	* &sk_buff.csum_not_inet, see :ref:`crc`)
195	* is called to resolve the checksum.
196	*
197	* - %CHECKSUM_NONE
198	*
199	* The skb was already checksummed by the protocol, or a checksum is not
200	* required.
201	*
202	* - %CHECKSUM_UNNECESSARY
203	*
204	* This has the same meaning as CHECKSUM_NONE for checksum offload on
205	* output.
206	*
207	* - %CHECKSUM_COMPLETE
208	*
209	* Not used in checksum output. If a driver observes a packet with this value
210	* set in skbuff, it should treat the packet as if %CHECKSUM_NONE were set.
211	*
212	* .. _crc:
213	*
214	* Non-IP checksum (CRC) offloads
215	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
216	*
217	* .. flat-table::
218	* :widths: 1 10
219	*
220	* * - %NETIF_F_SCTP_CRC
221	* - This feature indicates that a device is capable of
222	* offloading the SCTP CRC in a packet. To perform this offload the stack
223	* will set csum_start and csum_offset accordingly, set ip_summed to
224	* %CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication
225	* in the skbuff that the %CHECKSUM_PARTIAL refers to CRC32c.
226	* A driver that supports both IP checksum offload and SCTP CRC32c offload
227	* must verify which offload is configured for a packet by testing the
228	* value of &sk_buff.csum_not_inet; skb_crc32c_csum_help() is provided to
229	* resolve %CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1.
230	*
231	* * - %NETIF_F_FCOE_CRC
232	* - This feature indicates that a device is capable of offloading the FCOE
233	* CRC in a packet. To perform this offload the stack will set ip_summed
234	* to %CHECKSUM_PARTIAL and set csum_start and csum_offset
235	* accordingly. Note that there is no indication in the skbuff that the
236	* %CHECKSUM_PARTIAL refers to an FCOE checksum, so a driver that supports
237	* both IP checksum offload and FCOE CRC offload must verify which offload
238	* is configured for a packet, presumably by inspecting packet headers.
239	*
240	* Checksumming on output with GSO
241	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
242	*
243	* In the case of a GSO packet (skb_is_gso() is true), checksum offload
244	* is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the
245	* gso_type is %SKB_GSO_TCPV4 or %SKB_GSO_TCPV6, TCP checksum offload as
246	* part of the GSO operation is implied. If a checksum is being offloaded
247	* with GSO then ip_summed is %CHECKSUM_PARTIAL, and both csum_start and
248	* csum_offset are set to refer to the outermost checksum being offloaded
249	* (two offloaded checksums are possible with UDP encapsulation).
250	*/
251
252	/ Don't change this without changing skb_csum_unnecessary! /
253	#define CHECKSUM_NONE 0
254	#define CHECKSUM_UNNECESSARY 1
255	#define CHECKSUM_COMPLETE 2
256	#define CHECKSUM_PARTIAL 3
257
258	/ Maximum value in skb->csum_level /
259	#define SKB_MAX_CSUM_LEVEL 3
260
261	#define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
262	#define SKB_WITH_OVERHEAD(X) \
263	((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
264	#define SKB_MAX_ORDER(X, ORDER) \
265	SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
266	#define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
267	#define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
268
269	/ return minimum truesize of one skb containing X bytes of data /
270	#define SKB_TRUESIZE(X) ((X) + \
271	SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
272	SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
273
274	struct ahash_request;
275	struct net_device;
276	struct scatterlist;
277	struct pipe_inode_info;
278	struct iov_iter;
279	struct napi_struct;
280	struct bpf_prog;
281	union bpf_attr;
282	struct skb_ext;
283
284	#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
285	struct nf_bridge_info {
286	enum {
287	BRNF_PROTO_UNCHANGED,
288	BRNF_PROTO_8021Q,
289	BRNF_PROTO_PPPOE
290	} orig_proto:`8`;
291	u8 pkt_otherhost:`1`;
292	u8 in_prerouting:`1`;
293	u8 bridged_dnat:`1`;
294	__u16 frag_max_size;
295	struct net_device *physindev;
296
297	/ always valid & non-NULL from FORWARD on, for physdev match /
298	struct net_device *physoutdev;
299	union {
300	/ prerouting: detect dnat in orig/reply direction /
301	__be32 ipv4_daddr;
302	struct in6_addr ipv6_daddr;
303
304	/ after prerouting + nat detected: store original source*
305	* mac since neigh resolution overwrites it, only used while
306	* skb is out in neigh layer.
307	*/
308	char neigh_header[`8`];
309	};
310	};
311	#endif
312
313	#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
314	/ Chain in tc_skb_ext will be used to share the tc chain with*
315	* ovs recirc_id. It will be set to the current chain by tc
316	* and read by ovs to recirc_id.
317	*/
318	struct tc_skb_ext {
319	__u32 chain;
320	__u16 mru;
321	__u16 zone;
322	u8 post_ct:`1`;
323	u8 post_ct_snat:`1`;
324	u8 post_ct_dnat:`1`;
325	};
326	#endif
327
328	struct sk_buff_head {
329	/ These two members must be first to match sk_buff. /
330	struct_group_tagged(sk_buff_list, list,
331	struct sk_buff *next;
332	struct sk_buff *prev;
333	);
334
335	__u32 qlen;
336	spinlock_t lock;
337	};
338
339	struct sk_buff;
340
341	/ To allow 64K frame to be packed as single skb without frag_list we*
342	* require 64K/PAGE_SIZE pages plus 1 additional page to allow for
343	* buffers which do not start on a page boundary.
344	*
345	* Since GRO uses frags we allocate at least 16 regardless of page
346	* size.
347	*/
348	#if (65536/PAGE_SIZE + 1) < 16
349	#define MAX_SKB_FRAGS 16UL
350	#else
351	#define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
352	#endif
353	extern int sysctl_max_skb_frags;
354
355	/ Set skb_shinfo(skb)->gso_size to this in case you want skb_segment to*
356	* segment using its current segmentation instead.
357	*/
358	#define GSO_BY_FRAGS 0xFFFF
359
360	typedef struct bio_vec skb_frag_t;
361
362	/**
363	* skb_frag_size() - Returns the size of a skb fragment
364	* @frag: skb fragment
365	*/
366	static inline unsigned int skb_frag_size(const skb_frag_t *frag)
367	{
368	return frag->bv_len;
369	}
370
371	/**
372	* skb_frag_size_set() - Sets the size of a skb fragment
373	* @frag: skb fragment
374	* @size: size of fragment
375	*/
376	static inline void skb_frag_size_set(skb_frag_t frag, unsigned* int size)
377	{
378	frag->bv_len = size;
379	}
380
381	/**
382	* skb_frag_size_add() - Increments the size of a skb fragment by @delta
383	* @frag: skb fragment
384	* @delta: value to add
385	*/
386	static inline void skb_frag_size_add(skb_frag_t frag, int* delta)
387	{
388	frag->bv_len += delta;
389	}
390
391	/**
392	* skb_frag_size_sub() - Decrements the size of a skb fragment by @delta
393	* @frag: skb fragment
394	* @delta: value to subtract
395	*/
396	static inline void skb_frag_size_sub(skb_frag_t frag, int* delta)
397	{
398	frag->bv_len -= delta;
399	}
400
401	/**
402	* skb_frag_must_loop - Test if %p is a high memory page
403	* @p: fragment's page
404	*/
405	static inline bool skb_frag_must_loop(struct page *p)
406	{
407	#if defined(CONFIG_HIGHMEM)
408	if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP) \|\| PageHighMem(p))
409	return true;
410	#endif
411	return false;
412	}
413
414	/**
415	* skb_frag_foreach_page - loop over pages in a fragment
416	*
417	* @f: skb frag to operate on
418	* @f_off: offset from start of f->bv_page
419	* @f_len: length from f_off to loop over
420	* @p: (temp var) current page
421	* @p_off: (temp var) offset from start of current page,
422	* non-zero only on first page.
423	* @p_len: (temp var) length in current page,
424	* < PAGE_SIZE only on first and last page.
425	* @copied: (temp var) length so far, excluding current p_len.
426	*
427	* A fragment can hold a compound page, in which case per-page
428	* operations, notably kmap_atomic, must be called for each
429	* regular page.
430	*/
431	#define skb_frag_foreach_page(f, f_off, f_len, p, p_off, p_len, copied) \
432	for (p = skb_frag_page(f) + ((f_off) >> PAGE_SHIFT), \
433	p_off = (f_off) & (PAGE_SIZE - 1), \
434	p_len = skb_frag_must_loop(p) ? \
435	min_t(u32, f_len, PAGE_SIZE - p_off) : f_len, \
436	copied = 0; \
437	copied < f_len; \
438	copied += p_len, p++, p_off = 0, \
439	p_len = min_t(u32, f_len - copied, PAGE_SIZE)) \
440
441	#define HAVE_HW_TIME_STAMP
442
443	/**
444	* struct skb_shared_hwtstamps - hardware time stamps
445	* @hwtstamp: hardware time stamp transformed into duration
446	* since arbitrary point in time
447	* @netdev_data: address/cookie of network device driver used as
448	* reference to actual hardware time stamp
449	*
450	* Software time stamps generated by ktime_get_real() are stored in
451	* skb->tstamp.
452	*
453	* hwtstamps can only be compared against other hwtstamps from
454	* the same device.
455	*
456	* This structure is attached to packets as part of the
457	* &skb_shared_info. Use skb_hwtstamps() to get a pointer.
458	*/
459	struct skb_shared_hwtstamps {
460	union {
461	ktime_t hwtstamp;
462	void *netdev_data;
463	};
464	};
465
466	/ Definitions for tx_flags in struct skb_shared_info /
467	enum {
468	/ generate hardware time stamp /
469	SKBTX_HW_TSTAMP = `1` << `0`,
470
471	/ generate software time stamp when queueing packet to NIC /
472	SKBTX_SW_TSTAMP = `1` << `1`,
473
474	/ device driver is going to provide hardware time stamp /
475	SKBTX_IN_PROGRESS = `1` << `2`,
476
477	/ generate hardware time stamp based on cycles if supported /
478	SKBTX_HW_TSTAMP_USE_CYCLES = `1` << `3`,
479
480	/ generate wifi status information (where possible) /
481	SKBTX_WIFI_STATUS = `1` << `4`,
482
483	/ determine hardware time stamp based on time or cycles /
484	SKBTX_HW_TSTAMP_NETDEV = `1` << `5`,
485
486	/ generate software time stamp when entering packet scheduling /
487	SKBTX_SCHED_TSTAMP = `1` << `6`,
488	};
489
490	#define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP \| \
491	SKBTX_SCHED_TSTAMP)
492	#define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP \| \
493	SKBTX_HW_TSTAMP_USE_CYCLES \| \
494	SKBTX_ANY_SW_TSTAMP)
495
496	/ Definitions for flags in struct skb_shared_info /
497	enum {
498	/ use zcopy routines /
499	SKBFL_ZEROCOPY_ENABLE = BIT(`0`),
500
501	/ This indicates at least one fragment might be overwritten*
502	* (as in vmsplice(), sendfile() ...)
503	* If we need to compute a TX checksum, we'll need to copy
504	* all frags to avoid possible bad checksum
505	*/
506	SKBFL_SHARED_FRAG = BIT(`1`),
507
508	/ segment contains only zerocopy data and should not be*
509	* charged to the kernel memory.
510	*/
511	SKBFL_PURE_ZEROCOPY = BIT(`2`),
512
513	SKBFL_DONT_ORPHAN = BIT(`3`),
514
515	/ page references are managed by the ubuf_info, so it's safe to*
516	* use frags only up until ubuf_info is released
517	*/
518	SKBFL_MANAGED_FRAG_REFS = BIT(`4`),
519	};
520
521	#define SKBFL_ZEROCOPY_FRAG (SKBFL_ZEROCOPY_ENABLE \| SKBFL_SHARED_FRAG)
522	#define SKBFL_ALL_ZEROCOPY (SKBFL_ZEROCOPY_FRAG \| SKBFL_PURE_ZEROCOPY \| \
523	SKBFL_DONT_ORPHAN \| SKBFL_MANAGED_FRAG_REFS)
524
525	/*
526	* The callback notifies userspace to release buffers when skb DMA is done in
527	* lower device, the skb last reference should be 0 when calling this.
528	* The zerocopy_success argument is true if zero copy transmit occurred,
529	* false on data copy or out of memory error caused by data copy attempt.
530	* The ctx field is used to track device context.
531	* The desc field is used to track userspace buffer index.
532	*/
533	struct ubuf_info {
534	void (callback)(struct* sk_buff , struct* ubuf_info *,
535	bool zerocopy_success);
536	union {
537	struct {
538	unsigned long desc;
539	void *ctx;
540	};
541	struct {
542	u32 id;
543	u16 len;
544	u16 zerocopy:`1`;
545	u32 bytelen;
546	};
547	};
548	refcount_t refcnt;
549	u8 flags;
550
551	struct mmpin {
552	struct user_struct *user;
553	unsigned int num_pg;
554	} mmp;
555	};
556
557	#define skb_uarg(SKB) ((struct ubuf_info *)(skb_shinfo(SKB)->destructor_arg))
558
559	int mm_account_pinned_pages(struct mmpin *mmp, size_t size);
560	void mm_unaccount_pinned_pages(struct mmpin *mmp);
561
562	/ This data is invariant across clones and lives at*
563	* the end of the header data, ie. at skb->end.
564	*/
565	struct skb_shared_info {
566	__u8 flags;
567	__u8 meta_len;
568	__u8 nr_frags;
569	__u8 tx_flags;
570	unsigned short gso_size;
571	/ Warning: this field is not always filled in (UFO)! /
572	unsigned short gso_segs;
573	struct sk_buff *frag_list;
574	struct skb_shared_hwtstamps hwtstamps;
575	unsigned int gso_type;
576	u32 tskey;
577
578	/*
579	* Warning : all fields before dataref are cleared in __alloc_skb()
580	*/
581	atomic_t dataref;
582	unsigned int xdp_frags_size;
583
584	/ Intermediate layers must ensure that destructor_arg*
585	* remains valid until skb destructor */
586	void * destructor_arg;
587
588	/ must be last field, see pskb_expand_head() /
589	skb_frag_t frags[MAX_SKB_FRAGS];
590	};
591
592	/**
593	* DOC: dataref and headerless skbs
594	*
595	* Transport layers send out clones of payload skbs they hold for
596	* retransmissions. To allow lower layers of the stack to prepend their headers
597	* we split &skb_shared_info.dataref into two halves.
598	* The lower 16 bits count the overall number of references.
599	* The higher 16 bits indicate how many of the references are payload-only.
600	* skb_header_cloned() checks if skb is allowed to add / write the headers.
601	*
602	* The creator of the skb (e.g. TCP) marks its skb as &sk_buff.nohdr
603	* (via __skb_header_release()). Any clone created from marked skb will get
604	* &sk_buff.hdr_len populated with the available headroom.
605	* If there's the only clone in existence it's able to modify the headroom
606	* at will. The sequence of calls inside the transport layer is::
607	*
608	* <alloc skb>
609	* skb_reserve()
610	* __skb_header_release()
611	* skb_clone()
612	* // send the clone down the stack
613	*
614	* This is not a very generic construct and it depends on the transport layers
615	* doing the right thing. In practice there's usually only one payload-only skb.
616	* Having multiple payload-only skbs with different lengths of hdr_len is not
617	* possible. The payload-only skbs should never leave their owner.
618	*/
619	#define SKB_DATAREF_SHIFT 16
620	#define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
621
622
623	enum {
624	SKB_FCLONE_UNAVAILABLE, / skb has no fclone (from head_cache) /
625	SKB_FCLONE_ORIG, / orig skb (from fclone_cache) /
626	SKB_FCLONE_CLONE, / companion fclone skb (from fclone_cache) /
627	};
628
629	enum {
630	SKB_GSO_TCPV4 = `1` << `0`,
631
632	/ This indicates the skb is from an untrusted source. /
633	SKB_GSO_DODGY = `1` << `1`,
634
635	/ This indicates the tcp segment has CWR set. /
636	SKB_GSO_TCP_ECN = `1` << `2`,
637
638	SKB_GSO_TCP_FIXEDID = `1` << `3`,
639
640	SKB_GSO_TCPV6 = `1` << `4`,
641
642	SKB_GSO_FCOE = `1` << `5`,
643
644	SKB_GSO_GRE = `1` << `6`,
645
646	SKB_GSO_GRE_CSUM = `1` << `7`,
647
648	SKB_GSO_IPXIP4 = `1` << `8`,
649
650	SKB_GSO_IPXIP6 = `1` << `9`,
651
652	SKB_GSO_UDP_TUNNEL = `1` << `10`,
653
654	SKB_GSO_UDP_TUNNEL_CSUM = `1` << `11`,
655
656	SKB_GSO_PARTIAL = `1` << `12`,
657
658	SKB_GSO_TUNNEL_REMCSUM = `1` << `13`,
659
660	SKB_GSO_SCTP = `1` << `14`,
661
662	SKB_GSO_ESP = `1` << `15`,
663
664	SKB_GSO_UDP = `1` << `16`,
665
666	SKB_GSO_UDP_L4 = `1` << `17`,
667
668	SKB_GSO_FRAGLIST = `1` << `18`,
669	};
670
671	#if BITS_PER_LONG > 32
672	#define NET_SKBUFF_DATA_USES_OFFSET 1
673	#endif
674
675	#ifdef NET_SKBUFF_DATA_USES_OFFSET
676	typedef unsigned int sk_buff_data_t;
677	#else
678	typedef unsigned char *sk_buff_data_t;
679	#endif
680
681	/**
682	* DOC: Basic sk_buff geometry
683	*
684	* struct sk_buff itself is a metadata structure and does not hold any packet
685	* data. All the data is held in associated buffers.
686	*
687	* &sk_buff.head points to the main "head" buffer. The head buffer is divided
688	* into two parts:
689	*
690	* - data buffer, containing headers and sometimes payload;
691	* this is the part of the skb operated on by the common helpers
692	* such as skb_put() or skb_pull();
693	* - shared info (struct skb_shared_info) which holds an array of pointers
694	* to read-only data in the (page, offset, length) format.
695	*
696	* Optionally &skb_shared_info.frag_list may point to another skb.
697	*
698	* Basic diagram may look like this::
699	*
700	* ---------------
701	* \| sk_buff \|
702	* ---------------
703	* ,--------------------------- + head
704	* / ,----------------- + data
705	* / / ,----------- + tail
706	* \| \| \| , + end
707	* \| \| \| \|
708	* v v v v
709	* -----------------------------------------------
710	* \| headroom \| data \| tailroom \| skb_shared_info \|
711	* -----------------------------------------------
712	* + [page frag]
713	* + [page frag]
714	* + [page frag]
715	* + [page frag] ---------
716	* + frag_list --> \| sk_buff \|
717	* ---------
718	*
719	*/
720
721	/**
722	* struct sk_buff - socket buffer
723	* @next: Next buffer in list
724	* @prev: Previous buffer in list
725	* @tstamp: Time we arrived/left
726	* @skb_mstamp_ns: (aka @tstamp) earliest departure time; start point
727	* for retransmit timer
728	* @rbnode: RB tree node, alternative to next/prev for netem/tcp
729	* @list: queue head
730	* @ll_node: anchor in an llist (eg socket defer_list)
731	* @sk: Socket we are owned by
732	* @ip_defrag_offset: (aka @sk) alternate use of @sk, used in
733	* fragmentation management
734	* @dev: Device we arrived on/are leaving by
735	* @dev_scratch: (aka @dev) alternate use of @dev when @dev would be %NULL
736	* @cb: Control buffer. Free for use by every layer. Put private vars here
737	* @_skb_refdst: destination entry (with norefcount bit)
738	* @sp: the security path, used for xfrm
739	* @len: Length of actual data
740	* @data_len: Data length
741	* @mac_len: Length of link layer header
742	* @hdr_len: writable header length of cloned skb
743	* @csum: Checksum (must include start/offset pair)
744	* @csum_start: Offset from skb->head where checksumming should start
745	* @csum_offset: Offset from csum_start where checksum should be stored
746	* @priority: Packet queueing priority
747	* @ignore_df: allow local fragmentation
748	* @cloned: Head may be cloned (check refcnt to be sure)
749	* @ip_summed: Driver fed us an IP checksum
750	* @nohdr: Payload reference only, must not modify header
751	* @pkt_type: Packet class
752	* @fclone: skbuff clone status
753	* @ipvs_property: skbuff is owned by ipvs
754	* @inner_protocol_type: whether the inner protocol is
755	* ENCAP_TYPE_ETHER or ENCAP_TYPE_IPPROTO
756	* @remcsum_offload: remote checksum offload is enabled
757	* @offload_fwd_mark: Packet was L2-forwarded in hardware
758	* @offload_l3_fwd_mark: Packet was L3-forwarded in hardware
759	* @tc_skip_classify: do not classify packet. set by IFB device
760	* @tc_at_ingress: used within tc_classify to distinguish in/egress
761	* @redirected: packet was redirected by packet classifier
762	* @from_ingress: packet was redirected from the ingress path
763	* @nf_skip_egress: packet shall skip nf egress - see netfilter_netdev.h
764	* @peeked: this packet has been seen already, so stats have been
765	* done for it, don't do them again
766	* @nf_trace: netfilter packet trace flag
767	* @protocol: Packet protocol from driver
768	* @destructor: Destruct function
769	* @tcp_tsorted_anchor: list structure for TCP (tp->tsorted_sent_queue)
770	* @_sk_redir: socket redirection information for skmsg
771	* @_nfct: Associated connection, if any (with nfctinfo bits)
772	* @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
773	* @skb_iif: ifindex of device we arrived on
774	* @tc_index: Traffic control index
775	* @hash: the packet hash
776	* @queue_mapping: Queue mapping for multiqueue devices
777	* @head_frag: skb was allocated from page fragments,
778	* not allocated by kmalloc() or vmalloc().
779	* @pfmemalloc: skbuff was allocated from PFMEMALLOC reserves
780	* @pp_recycle: mark the packet for recycling instead of freeing (implies
781	* page_pool support on driver)
782	* @active_extensions: active extensions (skb_ext_id types)
783	* @ndisc_nodetype: router type (from link layer)
784	* @ooo_okay: allow the mapping of a socket to a queue to be changed
785	* @l4_hash: indicate hash is a canonical 4-tuple hash over transport
786	* ports.
787	* @sw_hash: indicates hash was computed in software stack
788	* @wifi_acked_valid: wifi_acked was set
789	* @wifi_acked: whether frame was acked on wifi or not
790	* @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
791	* @encapsulation: indicates the inner headers in the skbuff are valid
792	* @encap_hdr_csum: software checksum is needed
793	* @csum_valid: checksum is already valid
794	* @csum_not_inet: use CRC32c to resolve CHECKSUM_PARTIAL
795	* @csum_complete_sw: checksum was completed by software
796	* @csum_level: indicates the number of consecutive checksums found in
797	* the packet minus one that have been verified as
798	* CHECKSUM_UNNECESSARY (max 3)
799	* @dst_pending_confirm: need to confirm neighbour
800	* @decrypted: Decrypted SKB
801	* @slow_gro: state present at GRO time, slower prepare step required
802	* @mono_delivery_time: When set, skb->tstamp has the
803	* delivery_time in mono clock base (i.e. EDT). Otherwise, the
804	* skb->tstamp has the (rcv) timestamp at ingress and
805	* delivery_time at egress.
806	* @napi_id: id of the NAPI struct this skb came from
807	* @sender_cpu: (aka @napi_id) source CPU in XPS
808	* @alloc_cpu: CPU which did the skb allocation.
809	* @secmark: security marking
810	* @mark: Generic packet mark
811	* @reserved_tailroom: (aka @mark) number of bytes of free space available
812	* at the tail of an sk_buff
813	* @vlan_present: VLAN tag is present
814	* @vlan_proto: vlan encapsulation protocol
815	* @vlan_tci: vlan tag control information
816	* @inner_protocol: Protocol (encapsulation)
817	* @inner_ipproto: (aka @inner_protocol) stores ipproto when
818	* skb->inner_protocol_type == ENCAP_TYPE_IPPROTO;
819	* @inner_transport_header: Inner transport layer header (encapsulation)
820	* @inner_network_header: Network layer header (encapsulation)
821	* @inner_mac_header: Link layer header (encapsulation)
822	* @transport_header: Transport layer header
823	* @network_header: Network layer header
824	* @mac_header: Link layer header
825	* @kcov_handle: KCOV remote handle for remote coverage collection
826	* @tail: Tail pointer
827	* @end: End pointer
828	* @head: Head of buffer
829	* @data: Data head pointer
830	* @truesize: Buffer size
831	* @users: User count - see {datagram,tcp}.c
832	* @extensions: allocated extensions, valid if active_extensions is nonzero
833	*/
834
835	struct sk_buff {
836	union {
837	struct {
838	/ These two members must be first to match sk_buff_head. /
839	struct sk_buff *next;
840	struct sk_buff *prev;
841
842	union {
843	struct net_device *dev;
844	/ Some protocols might use this space to store information,*
845	* while device pointer would be NULL.
846	* UDP receive path is one user.
847	*/
848	unsigned long dev_scratch;
849	};
850	};
851	struct rb_node rbnode; / used in netem, ip4 defrag, and tcp stack /
852	struct list_head list;
853	struct llist_node ll_node;
854	};
855
856	union {
857	struct sock *sk;
858	int ip_defrag_offset;
859	};
860
861	union {
862	ktime_t tstamp;
863	u64 skb_mstamp_ns; / earliest departure time /
864	};
865	/*
866	* This is the control buffer. It is free to use for every
867	* layer. Please put your private variables there. If you
868	* want to keep them across layers you have to do a skb_clone()
869	* first. This is owned by whoever has the skb queued ATM.
870	*/
871	char cb[`48`] __aligned(`8`);
872
873	union {
874	struct {
875	unsigned long _skb_refdst;
876	void (destructor)(struct* sk_buff *skb);
877	};
878	struct list_head tcp_tsorted_anchor;
879	#ifdef CONFIG_NET_SOCK_MSG
880	unsigned long _sk_redir;
881	#endif
882	};
883
884	#if defined(CONFIG_NF_CONNTRACK) \|\| defined(CONFIG_NF_CONNTRACK_MODULE)
885	unsigned long _nfct;
886	#endif
887	unsigned int len,
888	data_len;
889	__u16 mac_len,
890	hdr_len;
891
892	/ Following fields are _not_ copied in __copy_skb_header()*
893	* Note that queue_mapping is here mostly to fill a hole.
894	*/
895	__u16 queue_mapping;
896
897	/ if you move cloned around you also must adapt those constants /
898	#ifdef __BIG_ENDIAN_BITFIELD
899	#define CLONED_MASK (1 << 7)
900	#else
901	#define CLONED_MASK 1
902	#endif
903	#define CLONED_OFFSET offsetof(struct sk_buff, __cloned_offset)
904
905	/ private: /
906	__u8 __cloned_offset[`0`];
907	/ public: /
908	__u8 cloned:`1`,
909	nohdr:`1`,
910	fclone:`2`,
911	peeked:`1`,
912	head_frag:`1`,
913	pfmemalloc:`1`,
914	pp_recycle:`1`; / page_pool recycle indicator /
915	#ifdef CONFIG_SKB_EXTENSIONS
916	__u8 active_extensions;
917	#endif
918
919	/ Fields enclosed in headers group are copied*
920	* using a single memcpy() in __copy_skb_header()
921	*/
922	struct_group(headers,
923
924	/ private: /
925	__u8 __pkt_type_offset[`0`];
926	/ public: /
927	__u8 pkt_type:`3`; / see PKT_TYPE_MAX /
928	__u8 ignore_df:`1`;
929	__u8 nf_trace:`1`;
930	__u8 ip_summed:`2`;
931	__u8 ooo_okay:`1`;
932
933	__u8 l4_hash:`1`;
934	__u8 sw_hash:`1`;
935	__u8 wifi_acked_valid:`1`;
936	__u8 wifi_acked:`1`;
937	__u8 no_fcs:`1`;
938	/ Indicates the inner headers are valid in the skbuff. /
939	__u8 encapsulation:`1`;
940	__u8 encap_hdr_csum:`1`;
941	__u8 csum_valid:`1`;
942
943	/ private: /
944	__u8 __pkt_vlan_present_offset[`0`];
945	/ public: /
946	__u8 vlan_present:`1`; / See PKT_VLAN_PRESENT_BIT /
947	__u8 csum_complete_sw:`1`;
948	__u8 csum_level:`2`;
949	__u8 dst_pending_confirm:`1`;
950	__u8 mono_delivery_time:`1`; / See SKB_MONO_DELIVERY_TIME_MASK /
951	#ifdef CONFIG_NET_CLS_ACT
952	__u8 tc_skip_classify:`1`;
953	__u8 tc_at_ingress:`1`; / See TC_AT_INGRESS_MASK /
954	#endif
955	#ifdef CONFIG_IPV6_NDISC_NODETYPE
956	__u8 ndisc_nodetype:`2`;
957	#endif
958
959	__u8 ipvs_property:`1`;
960	__u8 inner_protocol_type:`1`;
961	__u8 remcsum_offload:`1`;
962	#ifdef CONFIG_NET_SWITCHDEV
963	__u8 offload_fwd_mark:`1`;
964	__u8 offload_l3_fwd_mark:`1`;
965	#endif
966	__u8 redirected:`1`;
967	#ifdef CONFIG_NET_REDIRECT
968	__u8 from_ingress:`1`;
969	#endif
970	#ifdef CONFIG_NETFILTER_SKIP_EGRESS
971	__u8 nf_skip_egress:`1`;
972	#endif
973	#ifdef CONFIG_TLS_DEVICE
974	__u8 decrypted:`1`;
975	#endif
976	__u8 slow_gro:`1`;
977	__u8 csum_not_inet:`1`;
978
979	#ifdef CONFIG_NET_SCHED
980	__u16 tc_index; / traffic control index /
981	#endif
982
983	union {
984	__wsum csum;
985	struct {
986	__u16 csum_start;
987	__u16 csum_offset;
988	};
989	};
990	__u32 priority;
991	int skb_iif;
992	__u32 hash;
993	__be16 vlan_proto;
994	__u16 vlan_tci;
995	#if defined(CONFIG_NET_RX_BUSY_POLL) \|\| defined(CONFIG_XPS)
996	union {
997	unsigned int napi_id;
998	unsigned int sender_cpu;
999	};
1000	#endif
1001	u16 alloc_cpu;
1002	#ifdef CONFIG_NETWORK_SECMARK
1003	__u32 secmark;
1004	#endif
1005
1006	union {
1007	__u32 mark;
1008	__u32 reserved_tailroom;
1009	};
1010
1011	union {
1012	__be16 inner_protocol;
1013	__u8 inner_ipproto;
1014	};
1015
1016	__u16 inner_transport_header;
1017	__u16 inner_network_header;
1018	__u16 inner_mac_header;
1019
1020	__be16 protocol;
1021	__u16 transport_header;
1022	__u16 network_header;
1023	__u16 mac_header;
1024
1025	#ifdef CONFIG_KCOV
1026	u64 kcov_handle;
1027	#endif
1028
1029	); / end headers group /
1030
1031	/ These elements must be at the end, see alloc_skb() for details. /
1032	sk_buff_data_t tail;
1033	sk_buff_data_t end;
1034	unsigned char *head,
1035	*data;
1036	unsigned int truesize;
1037	refcount_t users;
1038
1039	#ifdef CONFIG_SKB_EXTENSIONS
1040	/ only useable after checking ->active_extensions != 0 /
1041	struct skb_ext *extensions;
1042	#endif
1043	};
1044
1045	/ if you move pkt_type around you also must adapt those constants /
1046	#ifdef __BIG_ENDIAN_BITFIELD
1047	#define PKT_TYPE_MAX (7 << 5)
1048	#else
1049	#define PKT_TYPE_MAX 7
1050	#endif
1051	#define PKT_TYPE_OFFSET offsetof(struct sk_buff, __pkt_type_offset)
1052
1053	/ if you move pkt_vlan_present, tc_at_ingress, or mono_delivery_time*
1054	* around, you also must adapt these constants.
1055	*/
1056	#ifdef __BIG_ENDIAN_BITFIELD
1057	#define PKT_VLAN_PRESENT_BIT 7
1058	#define TC_AT_INGRESS_MASK (1 << 0)
1059	#define SKB_MONO_DELIVERY_TIME_MASK (1 << 2)
1060	#else
1061	#define PKT_VLAN_PRESENT_BIT 0
1062	#define TC_AT_INGRESS_MASK (1 << 7)
1063	#define SKB_MONO_DELIVERY_TIME_MASK (1 << 5)
1064	#endif
1065	#define PKT_VLAN_PRESENT_OFFSET offsetof(struct sk_buff, __pkt_vlan_present_offset)
1066
1067	#ifdef __KERNEL__
1068	/*
1069	* Handling routines are only of interest to the kernel
1070	*/
1071
1072	#define SKB_ALLOC_FCLONE 0x01
1073	#define SKB_ALLOC_RX 0x02
1074	#define SKB_ALLOC_NAPI 0x04
1075
1076	/**
1077	* skb_pfmemalloc - Test if the skb was allocated from PFMEMALLOC reserves
1078	* @skb: buffer
1079	*/
1080	static inline bool skb_pfmemalloc(const struct sk_buff *skb)
1081	{
1082	return unlikely(skb->pfmemalloc);
1083	}
1084
1085	/*
1086	* skb might have a dst pointer attached, refcounted or not.
1087	* _skb_refdst low order bit is set if refcount was _not_ taken
1088	*/
1089	#define SKB_DST_NOREF 1UL
1090	#define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
1091
1092	/**
1093	* skb_dst - returns skb dst_entry
1094	* @skb: buffer
1095	*
1096	* Returns skb dst_entry, regardless of reference taken or not.
1097	*/
1098	static inline struct dst_entry skb_dst(const* struct sk_buff *skb)
1099	{
1100	/ If refdst was not refcounted, check we still are in a*
1101	* rcu_read_lock section
1102	*/
1103	WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
1104	!rcu_read_lock_held() &&
1105	!rcu_read_lock_bh_held());
1106	return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
1107	}
1108
1109	/**
1110	* skb_dst_set - sets skb dst
1111	* @skb: buffer
1112	* @dst: dst entry
1113	*
1114	* Sets skb dst, assuming a reference was taken on dst and should
1115	* be released by skb_dst_drop()
1116	*/
1117	static inline void skb_dst_set(struct sk_buff skb, struct* dst_entry *dst)
1118	{
1119	skb->slow_gro \|= !!dst;
1120	skb->_skb_refdst = (unsigned long)dst;
1121	}
1122
1123	/**
1124	* skb_dst_set_noref - sets skb dst, hopefully, without taking reference
1125	* @skb: buffer
1126	* @dst: dst entry
1127	*
1128	* Sets skb dst, assuming a reference was not taken on dst.
1129	* If dst entry is cached, we do not take reference and dst_release
1130	* will be avoided by refdst_drop. If dst entry is not cached, we take
1131	* reference, so that last dst_release can destroy the dst immediately.
1132	*/
1133	static inline void skb_dst_set_noref(struct sk_buff skb, struct* dst_entry *dst)
1134	{
1135	WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
1136	skb->slow_gro \|= !!dst;
1137	skb->_skb_refdst = (unsigned long)dst \| SKB_DST_NOREF;
1138	}
1139
1140	/**
1141	* skb_dst_is_noref - Test if skb dst isn't refcounted
1142	* @skb: buffer
1143	*/
1144	static inline bool skb_dst_is_noref(const struct sk_buff *skb)
1145	{
1146	return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
1147	}
1148
1149	/**
1150	* skb_rtable - Returns the skb &rtable
1151	* @skb: buffer
1152	*/
1153	static inline struct rtable skb_rtable(const* struct sk_buff *skb)
1154	{
1155	return (struct rtable *)skb_dst(skb);
1156	}
1157
1158	/ For mangling skb->pkt_type from user space side from applications*
1159	* such as nft, tc, etc, we only allow a conservative subset of
1160	* possible pkt_types to be set.
1161	*/
1162	static inline bool skb_pkt_type_ok(u32 ptype)
1163	{
1164	return ptype <= PACKET_OTHERHOST;
1165	}
1166
1167	/**
1168	* skb_napi_id - Returns the skb's NAPI id
1169	* @skb: buffer
1170	*/
1171	static inline unsigned int skb_napi_id(const struct sk_buff *skb)
1172	{
1173	#ifdef CONFIG_NET_RX_BUSY_POLL
1174	return skb->napi_id;
1175	#else
1176	return `0`;
1177	#endif
1178	}
1179
1180	/**
1181	* skb_unref - decrement the skb's reference count
1182	* @skb: buffer
1183	*
1184	* Returns true if we can free the skb.
1185	*/
1186	static inline bool skb_unref(struct sk_buff *skb)
1187	{
1188	if (unlikely(!skb))
1189	return false;
1190	if (likely(refcount_read(&skb->users) == `1`))
1191	smp_rmb();
1192	else if (likely(!refcount_dec_and_test(&skb->users)))
1193	return false;
1194
1195	return true;
1196	}
1197
1198	void kfree_skb_reason(struct sk_buff skb, enum* skb_drop_reason reason);
1199
1200	/**
1201	* kfree_skb - free an sk_buff with 'NOT_SPECIFIED' reason
1202	* @skb: buffer to free
1203	*/
1204	static inline void kfree_skb(struct sk_buff *skb)
1205	{
1206	kfree_skb_reason(skb, SKB_DROP_REASON_NOT_SPECIFIED);
1207	}
1208
1209	void skb_release_head_state(struct sk_buff *skb);
1210	void kfree_skb_list_reason(struct sk_buff *segs,
1211	enum skb_drop_reason reason);
1212	void skb_dump(const char level, const* struct sk_buff *skb, bool full_pkt);
1213	void skb_tx_error(struct sk_buff *skb);
1214
1215	static inline void kfree_skb_list(struct sk_buff *segs)
1216	{
1217	kfree_skb_list_reason(segs, SKB_DROP_REASON_NOT_SPECIFIED);
1218	}
1219
1220	#ifdef CONFIG_TRACEPOINTS
1221	void consume_skb(struct sk_buff *skb);
1222	#else
1223	static inline void consume_skb(struct sk_buff *skb)
1224	{
1225	return kfree_skb(skb);
1226	}
1227	#endif
1228
1229	void __consume_stateless_skb(struct sk_buff *skb);
1230	void __kfree_skb(struct sk_buff *skb);
1231	extern struct kmem_cache *skbuff_head_cache;
1232
1233	void kfree_skb_partial(struct sk_buff *skb, bool head_stolen);
1234	bool skb_try_coalesce(struct sk_buff to, struct* sk_buff *from,
1235	bool fragstolen, int* *delta_truesize);
1236
1237	struct sk_buff __alloc_skb(unsigned* int size, gfp_t priority, int flags,
1238	int node);
1239	struct sk_buff __build_skb(void* data, unsigned* int frag_size);
1240	struct sk_buff build_skb(void* data, unsigned* int frag_size);
1241	struct sk_buff build_skb_around(struct* sk_buff *skb,
1242	void data, unsigned* int frag_size);
1243	void skb_attempt_defer_free(struct sk_buff *skb);
1244
1245	struct sk_buff napi_build_skb(void* data, unsigned* int frag_size);
1246
1247	/**
1248	* alloc_skb - allocate a network buffer
1249	* @size: size to allocate
1250	* @priority: allocation mask
1251	*
1252	* This function is a convenient wrapper around __alloc_skb().
1253	*/
1254	static inline struct sk_buff alloc_skb(unsigned* int size,
1255	gfp_t priority)
1256	{
1257	return __alloc_skb(size, priority, `0`, NUMA_NO_NODE);
1258	}
1259
1260	struct sk_buff alloc_skb_with_frags(unsigned* long header_len,
1261	unsigned long data_len,
1262	int max_page_order,
1263	int *errcode,
1264	gfp_t gfp_mask);
1265	struct sk_buff alloc_skb_for_msg(struct* sk_buff *first);
1266
1267	/ Layout of fast clones : [skb1][skb2][fclone_ref] /
1268	struct sk_buff_fclones {
1269	struct sk_buff skb1;
1270
1271	struct sk_buff skb2;
1272
1273	refcount_t fclone_ref;
1274	};
1275
1276	/**
1277	* skb_fclone_busy - check if fclone is busy
1278	* @sk: socket
1279	* @skb: buffer
1280	*
1281	* Returns true if skb is a fast clone, and its clone is not freed.
1282	* Some drivers call skb_orphan() in their ndo_start_xmit(),
1283	* so we also check that this didnt happen.
1284	*/
1285	static inline bool skb_fclone_busy(const struct sock *sk,
1286	const struct sk_buff *skb)
1287	{
1288	const struct sk_buff_fclones *fclones;
1289
1290	fclones = container_of(skb, struct sk_buff_fclones, skb1);
1291
1292	return skb->fclone == SKB_FCLONE_ORIG &&
1293	refcount_read(&fclones->fclone_ref) > `1` &&
1294	READ_ONCE(fclones->skb2.sk) == sk;
1295	}
1296
1297	/**
1298	* alloc_skb_fclone - allocate a network buffer from fclone cache
1299	* @size: size to allocate
1300	* @priority: allocation mask
1301	*
1302	* This function is a convenient wrapper around __alloc_skb().
1303	*/
1304	static inline struct sk_buff alloc_skb_fclone(unsigned* int size,
1305	gfp_t priority)
1306	{
1307	return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE);
1308	}
1309
1310	struct sk_buff skb_morph(struct* sk_buff dst, struct* sk_buff *src);
1311	void skb_headers_offset_update(struct sk_buff skb, int* off);
1312	int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
1313	struct sk_buff skb_clone(struct* sk_buff *skb, gfp_t priority);
1314	void skb_copy_header(struct sk_buff new, const* struct sk_buff *old);
1315	struct sk_buff skb_copy(const* struct sk_buff *skb, gfp_t priority);
1316	struct sk_buff __pskb_copy_fclone(struct* sk_buff skb, int* headroom,
1317	gfp_t gfp_mask, bool fclone);
1318	static inline struct sk_buff __pskb_copy(struct* sk_buff skb, int* headroom,
1319	gfp_t gfp_mask)
1320	{
1321	return __pskb_copy_fclone(skb, headroom, gfp_mask, false);
1322	}
1323
1324	int pskb_expand_head(struct sk_buff skb, int* nhead, int ntail, gfp_t gfp_mask);
1325	struct sk_buff skb_realloc_headroom(struct* sk_buff *skb,
1326	unsigned int headroom);
1327	struct sk_buff skb_expand_head(struct* sk_buff skb, unsigned* int headroom);
1328	struct sk_buff skb_copy_expand(const* struct sk_buff skb, int* newheadroom,
1329	int newtailroom, gfp_t priority);
1330	int __must_check skb_to_sgvec_nomark(struct sk_buff skb, struct* scatterlist *sg,
1331	int offset, int len);
1332	int __must_check skb_to_sgvec(struct sk_buff skb, struct* scatterlist *sg,
1333	int offset, int len);
1334	int skb_cow_data(struct sk_buff skb, int* tailbits, struct sk_buff **trailer);
1335	int __skb_pad(struct sk_buff skb, int* pad, bool free_on_error);
1336
1337	/**
1338	* skb_pad - zero pad the tail of an skb
1339	* @skb: buffer to pad
1340	* @pad: space to pad
1341	*
1342	* Ensure that a buffer is followed by a padding area that is zero
1343	* filled. Used by network drivers which may DMA or transfer data
1344	* beyond the buffer end onto the wire.
1345	*
1346	* May return error in out of memory cases. The skb is freed on error.
1347	*/
1348	static inline int skb_pad(struct sk_buff skb, int* pad)
1349	{
1350	return __skb_pad(skb, pad, true);
1351	}
1352	#define dev_kfree_skb(a) consume_skb(a)
1353
1354	int skb_append_pagefrags(struct sk_buff skb, struct* page *page,
1355	int offset, size_t size);
1356
1357	struct skb_seq_state {
1358	__u32 lower_offset;
1359	__u32 upper_offset;
1360	__u32 frag_idx;
1361	__u32 stepped_offset;
1362	struct sk_buff *root_skb;
1363	struct sk_buff *cur_skb;
1364	__u8 *frag_data;
1365	__u32 frag_off;
1366	};
1367
1368	void skb_prepare_seq_read(struct sk_buff skb, unsigned* int from,
1369	unsigned int to, struct skb_seq_state *st);
1370	unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
1371	struct skb_seq_state *st);
1372	void skb_abort_seq_read(struct skb_seq_state *st);
1373
1374	unsigned int skb_find_text(struct sk_buff skb, unsigned* int from,
1375	unsigned int to, struct ts_config *config);
1376
1377	/*
1378	* Packet hash types specify the type of hash in skb_set_hash.
1379	*
1380	* Hash types refer to the protocol layer addresses which are used to
1381	* construct a packet's hash. The hashes are used to differentiate or identify
1382	* flows of the protocol layer for the hash type. Hash types are either
1383	* layer-2 (L2), layer-3 (L3), or layer-4 (L4).
1384	*
1385	* Properties of hashes:
1386	*
1387	* 1) Two packets in different flows have different hash values
1388	* 2) Two packets in the same flow should have the same hash value
1389	*
1390	* A hash at a higher layer is considered to be more specific. A driver should
1391	* set the most specific hash possible.
1392	*
1393	* A driver cannot indicate a more specific hash than the layer at which a hash
1394	* was computed. For instance an L3 hash cannot be set as an L4 hash.
1395	*
1396	* A driver may indicate a hash level which is less specific than the
1397	* actual layer the hash was computed on. For instance, a hash computed
1398	* at L4 may be considered an L3 hash. This should only be done if the
1399	* driver can't unambiguously determine that the HW computed the hash at
1400	* the higher layer. Note that the "should" in the second property above
1401	* permits this.
1402	*/
1403	enum pkt_hash_types {
1404	PKT_HASH_TYPE_NONE, / Undefined type /
1405	PKT_HASH_TYPE_L2, / Input: src_MAC, dest_MAC /
1406	PKT_HASH_TYPE_L3, / Input: src_IP, dst_IP /
1407	PKT_HASH_TYPE_L4, / Input: src_IP, dst_IP, src_port, dst_port /
1408	};
1409
1410	static inline void skb_clear_hash(struct sk_buff *skb)
1411	{
1412	skb->hash = `0`;
1413	skb->sw_hash = `0`;
1414	skb->l4_hash = `0`;
1415	}
1416
1417	static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb)
1418	{
1419	if (!skb->l4_hash)
1420	skb_clear_hash(skb);
1421	}
1422
1423	static inline void
1424	__skb_set_hash(struct sk_buff *skb, __u32 hash, bool is_sw, bool is_l4)
1425	{
1426	skb->l4_hash = is_l4;
1427	skb->sw_hash = is_sw;
1428	skb->hash = hash;
1429	}
1430
1431	static inline void
1432	skb_set_hash(struct sk_buff skb, __u32 hash, enum* pkt_hash_types type)
1433	{
1434	/ Used by drivers to set hash from HW /
1435	__skb_set_hash(skb, hash, false, type == PKT_HASH_TYPE_L4);
1436	}
1437
1438	static inline void
1439	__skb_set_sw_hash(struct sk_buff *skb, __u32 hash, bool is_l4)
1440	{
1441	__skb_set_hash(skb, hash, true, is_l4);
1442	}
1443
1444	void __skb_get_hash(struct sk_buff *skb);
1445	u32 __skb_get_hash_symmetric(const struct sk_buff *skb);
1446	u32 skb_get_poff(const struct sk_buff *skb);
1447	u32 __skb_get_poff(const struct sk_buff skb, const* void *data,
1448	const struct flow_keys_basic keys, int* hlen);
1449	__be32 __skb_flow_get_ports(const struct sk_buff skb, int* thoff, u8 ip_proto,
1450	const void data, int* hlen_proto);
1451
1452	static inline __be32 skb_flow_get_ports(const struct sk_buff *skb,
1453	int thoff, u8 ip_proto)
1454	{
1455	return __skb_flow_get_ports(skb, thoff, ip_proto, NULL, `0`);
1456	}
1457
1458	void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
1459	const struct flow_dissector_key *key,
1460	unsigned int key_count);
1461
1462	struct bpf_flow_dissector;
1463	bool bpf_flow_dissect(struct bpf_prog prog, struct* bpf_flow_dissector *ctx,
1464	__be16 proto, int nhoff, int hlen, unsigned int flags);
1465
1466	bool __skb_flow_dissect(const struct net *net,
1467	const struct sk_buff *skb,
1468	struct flow_dissector *flow_dissector,
1469	void target_container, const* void *data,
1470	__be16 proto, int nhoff, int hlen, unsigned int flags);
1471
1472	static inline bool skb_flow_dissect(const struct sk_buff *skb,
1473	struct flow_dissector *flow_dissector,
1474	void target_container, unsigned* int flags)
1475	{
1476	return __skb_flow_dissect(NULL, skb, flow_dissector,
1477	target_container, NULL, `0`, `0`, `0`, flags);
1478	}
1479
1480	static inline bool skb_flow_dissect_flow_keys(const struct sk_buff *skb,
1481	struct flow_keys *flow,
1482	unsigned int flags)
1483	{
1484	memset(flow, `0`, sizeof(*flow));
1485	return __skb_flow_dissect(NULL, skb, &flow_keys_dissector,
1486	flow, NULL, `0`, `0`, `0`, flags);
1487	}
1488
1489	static inline bool
1490	skb_flow_dissect_flow_keys_basic(const struct net *net,
1491	const struct sk_buff *skb,
1492	struct flow_keys_basic *flow,
1493	const void *data, __be16 proto,
1494	int nhoff, int hlen, unsigned int flags)
1495	{
1496	memset(flow, `0`, sizeof(*flow));
1497	return __skb_flow_dissect(net, skb, &flow_keys_basic_dissector, flow,
1498	data, proto, nhoff, hlen, flags);
1499	}
1500
1501	void skb_flow_dissect_meta(const struct sk_buff *skb,
1502	struct flow_dissector *flow_dissector,
1503	void *target_container);
1504
1505	/ Gets a skb connection tracking info, ctinfo map should be a*
1506	* map of mapsize to translate enum ip_conntrack_info states
1507	* to user states.
1508	*/
1509	void
1510	skb_flow_dissect_ct(const struct sk_buff *skb,
1511	struct flow_dissector *flow_dissector,
1512	void *target_container,
1513	u16 *ctinfo_map, size_t mapsize,
1514	bool post_ct, u16 zone);
1515	void
1516	skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
1517	struct flow_dissector *flow_dissector,
1518	void *target_container);
1519
1520	void skb_flow_dissect_hash(const struct sk_buff *skb,
1521	struct flow_dissector *flow_dissector,
1522	void *target_container);
1523
1524	static inline __u32 skb_get_hash(struct sk_buff *skb)
1525	{
1526	if (!skb->l4_hash && !skb->sw_hash)
1527	__skb_get_hash(skb);
1528
1529	return skb->hash;
1530	}
1531
1532	static inline __u32 skb_get_hash_flowi6(struct sk_buff skb, const* struct flowi6 *fl6)
1533	{
1534	if (!skb->l4_hash && !skb->sw_hash) {
1535	struct flow_keys keys;
1536	__u32 hash = __get_hash_from_flowi6(fl6, &keys);
1537
1538	__skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1539	}
1540
1541	return skb->hash;
1542	}
1543
1544	__u32 skb_get_hash_perturb(const struct sk_buff *skb,
1545	const siphash_key_t *perturb);
1546
1547	static inline __u32 skb_get_hash_raw(const struct sk_buff *skb)
1548	{
1549	return skb->hash;
1550	}
1551
1552	static inline void skb_copy_hash(struct sk_buff to, const* struct sk_buff *from)
1553	{
1554	to->hash = from->hash;
1555	to->sw_hash = from->sw_hash;
1556	to->l4_hash = from->l4_hash;
1557	};
1558
1559	static inline void skb_copy_decrypted(struct sk_buff *to,
1560	const struct sk_buff *from)
1561	{
1562	#ifdef CONFIG_TLS_DEVICE
1563	to->decrypted = from->decrypted;
1564	#endif
1565	}
1566
1567	#ifdef NET_SKBUFF_DATA_USES_OFFSET
1568	static inline unsigned char skb_end_pointer(const* struct sk_buff *skb)
1569	{
1570	return skb->head + skb->end;
1571	}
1572
1573	static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1574	{
1575	return skb->end;
1576	}
1577
1578	static inline void skb_set_end_offset(struct sk_buff skb, unsigned* int offset)
1579	{
1580	skb->end = offset;
1581	}
1582	#else
1583	static inline unsigned char skb_end_pointer(const* struct sk_buff *skb)
1584	{
1585	return skb->end;
1586	}
1587
1588	static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1589	{
1590	return skb->end - skb->head;
1591	}
1592
1593	static inline void skb_set_end_offset(struct sk_buff skb, unsigned* int offset)
1594	{
1595	skb->end = skb->head + offset;
1596	}
1597	#endif
1598
1599	struct ubuf_info msg_zerocopy_realloc(struct* sock *sk, size_t size,
1600	struct ubuf_info *uarg);
1601
1602	void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref);
1603
1604	void msg_zerocopy_callback(struct sk_buff skb, struct* ubuf_info *uarg,
1605	bool success);
1606
1607	int __zerocopy_sg_from_iter(struct msghdr msg, struct* sock *sk,
1608	struct sk_buff skb, struct* iov_iter *from,
1609	size_t length);
1610
1611	static inline int skb_zerocopy_iter_dgram(struct sk_buff *skb,
1612	struct msghdr msg, int* len)
1613	{
1614	return __zerocopy_sg_from_iter(msg, skb->sk, skb, &msg->msg_iter, len);
1615	}
1616
1617	int skb_zerocopy_iter_stream(struct sock sk, struct* sk_buff *skb,
1618	struct msghdr msg, int* len,
1619	struct ubuf_info *uarg);
1620
1621	/ Internal /
1622	#define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
1623
1624	static inline struct skb_shared_hwtstamps skb_hwtstamps(struct* sk_buff *skb)
1625	{
1626	return &skb_shinfo(skb)->hwtstamps;
1627	}
1628
1629	static inline struct ubuf_info skb_zcopy(struct* sk_buff *skb)
1630	{
1631	bool is_zcopy = skb && skb_shinfo(skb)->flags & SKBFL_ZEROCOPY_ENABLE;
1632
1633	return is_zcopy ? skb_uarg(skb) : NULL;
1634	}
1635
1636	static inline bool skb_zcopy_pure(const struct sk_buff *skb)
1637	{
1638	return skb_shinfo(skb)->flags & SKBFL_PURE_ZEROCOPY;
1639	}
1640
1641	static inline bool skb_zcopy_managed(const struct sk_buff *skb)
1642	{
1643	return skb_shinfo(skb)->flags & SKBFL_MANAGED_FRAG_REFS;
1644	}
1645
1646	static inline bool skb_pure_zcopy_same(const struct sk_buff *skb1,
1647	const struct sk_buff *skb2)
1648	{
1649	return skb_zcopy_pure(skb1) == skb_zcopy_pure(skb2);
1650	}
1651
1652	static inline void net_zcopy_get(struct ubuf_info *uarg)
1653	{
1654	refcount_inc(&uarg->refcnt);
1655	}
1656
1657	static inline void skb_zcopy_init(struct sk_buff skb, struct* ubuf_info *uarg)
1658	{
1659	skb_shinfo(skb)->destructor_arg = uarg;
1660	skb_shinfo(skb)->flags \|= uarg->flags;
1661	}
1662
1663	static inline void skb_zcopy_set(struct sk_buff skb, struct* ubuf_info *uarg,
1664	bool *have_ref)
1665	{
1666	if (skb && uarg && !skb_zcopy(skb)) {
1667	if (unlikely(have_ref && *have_ref))
1668	*have_ref = false;
1669	else
1670	net_zcopy_get(uarg);
1671	skb_zcopy_init(skb, uarg);
1672	}
1673	}
1674
1675	static inline void skb_zcopy_set_nouarg(struct sk_buff skb, void* *val)
1676	{
1677	skb_shinfo(skb)->destructor_arg = (void *)((uintptr_t) val \| `0x1UL`);
1678	skb_shinfo(skb)->flags \|= SKBFL_ZEROCOPY_FRAG;
1679	}
1680
1681	static inline bool skb_zcopy_is_nouarg(struct sk_buff *skb)
1682	{
1683	return (uintptr_t) skb_shinfo(skb)->destructor_arg & `0x1UL`;
1684	}
1685
1686	static inline void skb_zcopy_get_nouarg(struct* sk_buff *skb)
1687	{
1688	return (void *)((uintptr_t) skb_shinfo(skb)->destructor_arg & ~`0x1UL`);
1689	}
1690
1691	static inline void net_zcopy_put(struct ubuf_info *uarg)
1692	{
1693	if (uarg)
1694	uarg->callback(NULL, uarg, true);
1695	}
1696
1697	static inline void net_zcopy_put_abort(struct ubuf_info *uarg, bool have_uref)
1698	{
1699	if (uarg) {
1700	if (uarg->callback == msg_zerocopy_callback)
1701	msg_zerocopy_put_abort(uarg, have_uref);
1702	else if (have_uref)
1703	net_zcopy_put(uarg);
1704	}
1705	}
1706
1707	/ Release a reference on a zerocopy structure /
1708	static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success)
1709	{
1710	struct ubuf_info *uarg = skb_zcopy(skb);
1711
1712	if (uarg) {
1713	if (!skb_zcopy_is_nouarg(skb))
1714	uarg->callback(skb, uarg, zerocopy_success);
1715
1716	skb_shinfo(skb)->flags &= ~SKBFL_ALL_ZEROCOPY;
1717	}
1718	}
1719
1720	void __skb_zcopy_downgrade_managed(struct sk_buff *skb);
1721
1722	static inline void skb_zcopy_downgrade_managed(struct sk_buff *skb)
1723	{
1724	if (unlikely(skb_zcopy_managed(skb)))
1725	__skb_zcopy_downgrade_managed(skb);
1726	}
1727
1728	static inline void skb_mark_not_on_list(struct sk_buff *skb)
1729	{
1730	skb->next = NULL;
1731	}
1732
1733	/ Iterate through singly-linked GSO fragments of an skb. /
1734	#define skb_list_walk_safe(first, skb, next_skb) \
1735	for ((skb) = (first), (next_skb) = (skb) ? (skb)->next : NULL; (skb); \
1736	(skb) = (next_skb), (next_skb) = (skb) ? (skb)->next : NULL)
1737
1738	static inline void skb_list_del_init(struct sk_buff *skb)
1739	{
1740	__list_del_entry(&skb->list);
1741	skb_mark_not_on_list(skb);
1742	}
1743
1744	/**
1745	* skb_queue_empty - check if a queue is empty
1746	* @list: queue head
1747	*
1748	* Returns true if the queue is empty, false otherwise.
1749	*/
1750	static inline int skb_queue_empty(const struct sk_buff_head *list)
1751	{
1752	return list->next == (const struct sk_buff *) list;
1753	}
1754
1755	/**
1756	* skb_queue_empty_lockless - check if a queue is empty
1757	* @list: queue head
1758	*
1759	* Returns true if the queue is empty, false otherwise.
1760	* This variant can be used in lockless contexts.
1761	*/
1762	static inline bool skb_queue_empty_lockless(const struct sk_buff_head *list)
1763	{
1764	return READ_ONCE(list->next) == (const struct sk_buff *) list;
1765	}
1766
1767
1768	/**
1769	* skb_queue_is_last - check if skb is the last entry in the queue
1770	* @list: queue head
1771	* @skb: buffer
1772	*
1773	* Returns true if @skb is the last buffer on the list.
1774	*/
1775	static inline bool skb_queue_is_last(const struct sk_buff_head *list,
1776	const struct sk_buff *skb)
1777	{
1778	return skb->next == (const struct sk_buff *) list;
1779	}
1780
1781	/**
1782	* skb_queue_is_first - check if skb is the first entry in the queue
1783	* @list: queue head
1784	* @skb: buffer
1785	*
1786	* Returns true if @skb is the first buffer on the list.
1787	*/
1788	static inline bool skb_queue_is_first(const struct sk_buff_head *list,
1789	const struct sk_buff *skb)
1790	{
1791	return skb->prev == (const struct sk_buff *) list;
1792	}
1793
1794	/**
1795	* skb_queue_next - return the next packet in the queue
1796	* @list: queue head
1797	* @skb: current buffer
1798	*
1799	* Return the next packet in @list after @skb. It is only valid to
1800	* call this if skb_queue_is_last() evaluates to false.
1801	*/
1802	static inline struct sk_buff skb_queue_next(const* struct sk_buff_head *list,
1803	const struct sk_buff *skb)
1804	{
1805	/ This BUG_ON may seem severe, but if we just return then we*
1806	* are going to dereference garbage.
1807	*/
1808	BUG_ON(skb_queue_is_last(list, skb));
1809	return skb->next;
1810	}
1811
1812	/**
1813	* skb_queue_prev - return the prev packet in the queue
1814	* @list: queue head
1815	* @skb: current buffer
1816	*
1817	* Return the prev packet in @list before @skb. It is only valid to
1818	* call this if skb_queue_is_first() evaluates to false.
1819	*/
1820	static inline struct sk_buff skb_queue_prev(const* struct sk_buff_head *list,
1821	const struct sk_buff *skb)
1822	{
1823	/ This BUG_ON may seem severe, but if we just return then we*
1824	* are going to dereference garbage.
1825	*/
1826	BUG_ON(skb_queue_is_first(list, skb));
1827	return skb->prev;
1828	}
1829
1830	/**
1831	* skb_get - reference buffer
1832	* @skb: buffer to reference
1833	*
1834	* Makes another reference to a socket buffer and returns a pointer
1835	* to the buffer.
1836	*/
1837	static inline struct sk_buff skb_get(struct* sk_buff *skb)
1838	{
1839	refcount_inc(&skb->users);
1840	return skb;
1841	}
1842
1843	/*
1844	* If users == 1, we are the only owner and can avoid redundant atomic changes.
1845	*/
1846
1847	/**
1848	* skb_cloned - is the buffer a clone
1849	* @skb: buffer to check
1850	*
1851	* Returns true if the buffer was generated with skb_clone() and is
1852	* one of multiple shared copies of the buffer. Cloned buffers are
1853	* shared data so must not be written to under normal circumstances.
1854	*/
1855	static inline int skb_cloned(const struct sk_buff *skb)
1856	{
1857	return skb->cloned &&
1858	(atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != `1`;
1859	}
1860
1861	static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
1862	{
1863	might_sleep_if(gfpflags_allow_blocking(pri));
1864
1865	if (skb_cloned(skb))
1866	return pskb_expand_head(skb, `0`, `0`, pri);
1867
1868	return `0`;
1869	}
1870
1871	/ This variant of skb_unclone() makes sure skb->truesize*
1872	* and skb_end_offset() are not changed, whenever a new skb->head is needed.
1873	*
1874	* Indeed there is no guarantee that ksize(kmalloc(X)) == ksize(kmalloc(X))
1875	* when various debugging features are in place.
1876	*/
1877	int __skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri);
1878	static inline int skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri)
1879	{
1880	might_sleep_if(gfpflags_allow_blocking(pri));
1881
1882	if (skb_cloned(skb))
1883	return __skb_unclone_keeptruesize(skb, pri);
1884	return `0`;
1885	}
1886
1887	/**
1888	* skb_header_cloned - is the header a clone
1889	* @skb: buffer to check
1890	*
1891	* Returns true if modifying the header part of the buffer requires
1892	* the data to be copied.
1893	*/
1894	static inline int skb_header_cloned(const struct sk_buff *skb)
1895	{
1896	int dataref;
1897
1898	if (!skb->cloned)
1899	return `0`;
1900
1901	dataref = atomic_read(&skb_shinfo(skb)->dataref);
1902	dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
1903	return dataref != `1`;
1904	}
1905
1906	static inline int skb_header_unclone(struct sk_buff *skb, gfp_t pri)
1907	{
1908	might_sleep_if(gfpflags_allow_blocking(pri));
1909
1910	if (skb_header_cloned(skb))
1911	return pskb_expand_head(skb, `0`, `0`, pri);
1912
1913	return `0`;
1914	}
1915
1916	/**
1917	* __skb_header_release() - allow clones to use the headroom
1918	* @skb: buffer to operate on
1919	*
1920	* See "DOC: dataref and headerless skbs".
1921	*/
1922	static inline void __skb_header_release(struct sk_buff *skb)
1923	{
1924	skb->nohdr = `1`;
1925	atomic_set(&skb_shinfo(skb)->dataref, `1` + (`1` << SKB_DATAREF_SHIFT));
1926	}
1927
1928
1929	/**
1930	* skb_shared - is the buffer shared
1931	* @skb: buffer to check
1932	*
1933	* Returns true if more than one person has a reference to this
1934	* buffer.
1935	*/
1936	static inline int skb_shared(const struct sk_buff *skb)
1937	{
1938	return refcount_read(&skb->users) != `1`;
1939	}
1940
1941	/**
1942	* skb_share_check - check if buffer is shared and if so clone it
1943	* @skb: buffer to check
1944	* @pri: priority for memory allocation
1945	*
1946	* If the buffer is shared the buffer is cloned and the old copy
1947	* drops a reference. A new clone with a single reference is returned.
1948	* If the buffer is not shared the original buffer is returned. When
1949	* being called from interrupt status or with spinlocks held pri must
1950	* be GFP_ATOMIC.
1951	*
1952	* NULL is returned on a memory allocation failure.
1953	*/
1954	static inline struct sk_buff skb_share_check(struct* sk_buff *skb, gfp_t pri)
1955	{
1956	might_sleep_if(gfpflags_allow_blocking(pri));
1957	if (skb_shared(skb)) {
1958	struct sk_buff *nskb = skb_clone(skb, pri);
1959
1960	if (likely(nskb))
1961	consume_skb(skb);
1962	else
1963	kfree_skb(skb);
1964	skb = nskb;
1965	}
1966	return skb;
1967	}
1968
1969	/*
1970	* Copy shared buffers into a new sk_buff. We effectively do COW on
1971	* packets to handle cases where we have a local reader and forward
1972	* and a couple of other messy ones. The normal one is tcpdumping
1973	* a packet thats being forwarded.
1974	*/
1975
1976	/**
1977	* skb_unshare - make a copy of a shared buffer
1978	* @skb: buffer to check
1979	* @pri: priority for memory allocation
1980	*
1981	* If the socket buffer is a clone then this function creates a new
1982	* copy of the data, drops a reference count on the old copy and returns
1983	* the new copy with the reference count at 1. If the buffer is not a clone
1984	* the original buffer is returned. When called with a spinlock held or
1985	* from interrupt state @pri must be %GFP_ATOMIC
1986	*
1987	* %NULL is returned on a memory allocation failure.
1988	*/
1989	static inline struct sk_buff skb_unshare(struct* sk_buff *skb,
1990	gfp_t pri)
1991	{
1992	might_sleep_if(gfpflags_allow_blocking(pri));
1993	if (skb_cloned(skb)) {
1994	struct sk_buff *nskb = skb_copy(skb, pri);
1995
1996	/ Free our shared copy /
1997	if (likely(nskb))
1998	consume_skb(skb);
1999	else
2000	kfree_skb(skb);
2001	skb = nskb;
2002	}
2003	return skb;
2004	}
2005
2006	/**
2007	* skb_peek - peek at the head of an &sk_buff_head
2008	* @list_: list to peek at
2009	*
2010	* Peek an &sk_buff. Unlike most other operations you _MUST_
2011	* be careful with this one. A peek leaves the buffer on the
2012	* list and someone else may run off with it. You must hold
2013	* the appropriate locks or have a private queue to do this.
2014	*
2015	* Returns %NULL for an empty list or a pointer to the head element.
2016	* The reference count is not incremented and the reference is therefore
2017	* volatile. Use with caution.
2018	*/
2019	static inline struct sk_buff skb_peek(const* struct sk_buff_head *list_)
2020	{
2021	struct sk_buff *skb = list_->next;
2022
2023	if (skb == (struct sk_buff *)list_)
2024	skb = NULL;
2025	return skb;
2026	}
2027
2028	/**
2029	* __skb_peek - peek at the head of a non-empty &sk_buff_head
2030	* @list_: list to peek at
2031	*
2032	* Like skb_peek(), but the caller knows that the list is not empty.
2033	*/
2034	static inline struct sk_buff __skb_peek(const* struct sk_buff_head *list_)
2035	{
2036	return list_->next;
2037	}
2038
2039	/**
2040	* skb_peek_next - peek skb following the given one from a queue
2041	* @skb: skb to start from
2042	* @list_: list to peek at
2043	*
2044	* Returns %NULL when the end of the list is met or a pointer to the
2045	* next element. The reference count is not incremented and the
2046	* reference is therefore volatile. Use with caution.
2047	*/
2048	static inline struct sk_buff skb_peek_next(struct* sk_buff *skb,
2049	const struct sk_buff_head *list_)
2050	{
2051	struct sk_buff *next = skb->next;
2052
2053	if (next == (struct sk_buff *)list_)
2054	next = NULL;
2055	return next;
2056	}
2057
2058	/**
2059	* skb_peek_tail - peek at the tail of an &sk_buff_head
2060	* @list_: list to peek at
2061	*
2062	* Peek an &sk_buff. Unlike most other operations you _MUST_
2063	* be careful with this one. A peek leaves the buffer on the
2064	* list and someone else may run off with it. You must hold
2065	* the appropriate locks or have a private queue to do this.
2066	*
2067	* Returns %NULL for an empty list or a pointer to the tail element.
2068	* The reference count is not incremented and the reference is therefore
2069	* volatile. Use with caution.
2070	*/
2071	static inline struct sk_buff skb_peek_tail(const* struct sk_buff_head *list_)
2072	{
2073	struct sk_buff *skb = READ_ONCE(list_->prev);
2074
2075	if (skb == (struct sk_buff *)list_)
2076	skb = NULL;
2077	return skb;
2078
2079	}
2080
2081	/**
2082	* skb_queue_len - get queue length
2083	* @list_: list to measure
2084	*
2085	* Return the length of an &sk_buff queue.
2086	*/
2087	static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
2088	{
2089	return list_->qlen;
2090	}
2091
2092	/**
2093	* skb_queue_len_lockless - get queue length
2094	* @list_: list to measure
2095	*
2096	* Return the length of an &sk_buff queue.
2097	* This variant can be used in lockless contexts.
2098	*/
2099	static inline __u32 skb_queue_len_lockless(const struct sk_buff_head *list_)
2100	{
2101	return READ_ONCE(list_->qlen);
2102	}
2103
2104	/**
2105	* __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
2106	* @list: queue to initialize
2107	*
2108	* This initializes only the list and queue length aspects of
2109	* an sk_buff_head object. This allows to initialize the list
2110	* aspects of an sk_buff_head without reinitializing things like
2111	* the spinlock. It can also be used for on-stack sk_buff_head
2112	* objects where the spinlock is known to not be used.
2113	*/
2114	static inline void __skb_queue_head_init(struct sk_buff_head *list)
2115	{
2116	list->prev = list->next = (struct sk_buff *)list;
2117	list->qlen = `0`;
2118	}
2119
2120	/*
2121	* This function creates a split out lock class for each invocation;
2122	* this is needed for now since a whole lot of users of the skb-queue
2123	* infrastructure in drivers have different locking usage (in hardirq)
2124	* than the networking core (in softirq only). In the long run either the
2125	* network layer or drivers should need annotation to consolidate the
2126	* main types of usage into 3 classes.
2127	*/
2128	static inline void skb_queue_head_init(struct sk_buff_head *list)
2129	{
2130	spin_lock_init(&list->lock);
2131	__skb_queue_head_init(list);
2132	}
2133
2134	static inline void skb_queue_head_init_class(struct sk_buff_head *list,
2135	struct lock_class_key *class)
2136	{
2137	skb_queue_head_init(list);
2138	lockdep_set_class(&list->lock, class);
2139	}
2140
2141	/*
2142	* Insert an sk_buff on a list.
2143	*
2144	* The "__skb_xxxx()" functions are the non-atomic ones that
2145	* can only be called with interrupts disabled.
2146	*/
2147	static inline void __skb_insert(struct sk_buff *newsk,
2148	struct sk_buff prev, struct* sk_buff *next,
2149	struct sk_buff_head *list)
2150	{
2151	/ See skb_queue_empty_lockless() and skb_peek_tail()*
2152	* for the opposite READ_ONCE()
2153	*/
2154	WRITE_ONCE(newsk->next, next);
2155	WRITE_ONCE(newsk->prev, prev);
2156	WRITE_ONCE(((struct sk_buff_list *)next)->prev, newsk);
2157	WRITE_ONCE(((struct sk_buff_list *)prev)->next, newsk);
2158	WRITE_ONCE(list->qlen, list->qlen + `1`);
2159	}
2160
2161	static inline void __skb_queue_splice(const struct sk_buff_head *list,
2162	struct sk_buff *prev,
2163	struct sk_buff *next)
2164	{
2165	struct sk_buff *first = list->next;
2166	struct sk_buff *last = list->prev;
2167
2168	WRITE_ONCE(first->prev, prev);
2169	WRITE_ONCE(prev->next, first);
2170
2171	WRITE_ONCE(last->next, next);
2172	WRITE_ONCE(next->prev, last);
2173	}
2174
2175	/**
2176	* skb_queue_splice - join two skb lists, this is designed for stacks
2177	* @list: the new list to add
2178	* @head: the place to add it in the first list
2179	*/
2180	static inline void skb_queue_splice(const struct sk_buff_head *list,
2181	struct sk_buff_head *head)
2182	{
2183	if (!skb_queue_empty(list)) {
2184	__skb_queue_splice(list, (struct sk_buff *) head, head->next);
2185	head->qlen += list->qlen;
2186	}
2187	}
2188
2189	/**
2190	* skb_queue_splice_init - join two skb lists and reinitialise the emptied list
2191	* @list: the new list to add
2192	* @head: the place to add it in the first list
2193	*
2194	* The list at @list is reinitialised
2195	*/
2196	static inline void skb_queue_splice_init(struct sk_buff_head *list,
2197	struct sk_buff_head *head)
2198	{
2199	if (!skb_queue_empty(list)) {
2200	__skb_queue_splice(list, (struct sk_buff *) head, head->next);
2201	head->qlen += list->qlen;
2202	__skb_queue_head_init(list);
2203	}
2204	}
2205
2206	/**
2207	* skb_queue_splice_tail - join two skb lists, each list being a queue
2208	* @list: the new list to add
2209	* @head: the place to add it in the first list
2210	*/
2211	static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
2212	struct sk_buff_head *head)
2213	{
2214	if (!skb_queue_empty(list)) {
2215	__skb_queue_splice(list, head->prev, (struct sk_buff *) head);
2216	head->qlen += list->qlen;
2217	}
2218	}
2219
2220	/**
2221	* skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
2222	* @list: the new list to add
2223	* @head: the place to add it in the first list
2224	*
2225	* Each of the lists is a queue.
2226	* The list at @list is reinitialised
2227	*/
2228	static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
2229	struct sk_buff_head *head)
2230	{
2231	if (!skb_queue_empty(list)) {
2232	__skb_queue_splice(list, head->prev, (struct sk_buff *) head);
2233	head->qlen += list->qlen;
2234	__skb_queue_head_init(list);
2235	}
2236	}
2237
2238	/**
2239	* __skb_queue_after - queue a buffer at the list head
2240	* @list: list to use
2241	* @prev: place after this buffer
2242	* @newsk: buffer to queue
2243	*
2244	* Queue a buffer int the middle of a list. This function takes no locks
2245	* and you must therefore hold required locks before calling it.
2246	*
2247	* A buffer cannot be placed on two lists at the same time.
2248	*/
2249	static inline void __skb_queue_after(struct sk_buff_head *list,
2250	struct sk_buff *prev,
2251	struct sk_buff *newsk)
2252	{
2253	__skb_insert(newsk, prev, ((struct sk_buff_list *)prev)->next, list);
2254	}
2255
2256	void skb_append(struct sk_buff old, struct* sk_buff *newsk,
2257	struct sk_buff_head *list);
2258
2259	static inline void __skb_queue_before(struct sk_buff_head *list,
2260	struct sk_buff *next,
2261	struct sk_buff *newsk)
2262	{
2263	__skb_insert(newsk, ((struct sk_buff_list *)next)->prev, next, list);
2264	}
2265
2266	/**
2267	* __skb_queue_head - queue a buffer at the list head
2268	* @list: list to use
2269	* @newsk: buffer to queue
2270	*
2271	* Queue a buffer at the start of a list. This function takes no locks
2272	* and you must therefore hold required locks before calling it.
2273	*
2274	* A buffer cannot be placed on two lists at the same time.
2275	*/
2276	static inline void __skb_queue_head(struct sk_buff_head *list,
2277	struct sk_buff *newsk)
2278	{
2279	__skb_queue_after(list, (struct sk_buff *)list, newsk);
2280	}
2281	void skb_queue_head(struct sk_buff_head list, struct* sk_buff *newsk);
2282
2283	/**
2284	* __skb_queue_tail - queue a buffer at the list tail
2285	* @list: list to use
2286	* @newsk: buffer to queue
2287	*
2288	* Queue a buffer at the end of a list. This function takes no locks
2289	* and you must therefore hold required locks before calling it.
2290	*
2291	* A buffer cannot be placed on two lists at the same time.
2292	*/
2293	static inline void __skb_queue_tail(struct sk_buff_head *list,
2294	struct sk_buff *newsk)
2295	{
2296	__skb_queue_before(list, (struct sk_buff *)list, newsk);
2297	}
2298	void skb_queue_tail(struct sk_buff_head list, struct* sk_buff *newsk);
2299
2300	/*
2301	* remove sk_buff from list. _Must_ be called atomically, and with
2302	* the list known..
2303	*/
2304	void skb_unlink(struct sk_buff skb, struct* sk_buff_head *list);
2305	static inline void __skb_unlink(struct sk_buff skb, struct* sk_buff_head *list)
2306	{
2307	struct sk_buff next, prev;
2308
2309	WRITE_ONCE(list->qlen, list->qlen - `1`);
2310	next = skb->next;
2311	prev = skb->prev;
2312	skb->next = skb->prev = NULL;
2313	WRITE_ONCE(next->prev, prev);
2314	WRITE_ONCE(prev->next, next);
2315	}
2316
2317	/**
2318	* __skb_dequeue - remove from the head of the queue
2319	* @list: list to dequeue from
2320	*
2321	* Remove the head of the list. This function does not take any locks
2322	* so must be used with appropriate locks held only. The head item is
2323	* returned or %NULL if the list is empty.
2324	*/
2325	static inline struct sk_buff __skb_dequeue(struct* sk_buff_head *list)
2326	{
2327	struct sk_buff *skb = skb_peek(list);
2328	if (skb)
2329	__skb_unlink(skb, list);
2330	return skb;
2331	}
2332	struct sk_buff skb_dequeue(struct* sk_buff_head *list);
2333
2334	/**
2335	* __skb_dequeue_tail - remove from the tail of the queue
2336	* @list: list to dequeue from
2337	*
2338	* Remove the tail of the list. This function does not take any locks
2339	* so must be used with appropriate locks held only. The tail item is
2340	* returned or %NULL if the list is empty.
2341	*/
2342	static inline struct sk_buff __skb_dequeue_tail(struct* sk_buff_head *list)
2343	{
2344	struct sk_buff *skb = skb_peek_tail(list);
2345	if (skb)
2346	__skb_unlink(skb, list);
2347	return skb;
2348	}
2349	struct sk_buff skb_dequeue_tail(struct* sk_buff_head *list);
2350
2351
2352	static inline bool skb_is_nonlinear(const struct sk_buff *skb)
2353	{
2354	return skb->data_len;
2355	}
2356
2357	static inline unsigned int skb_headlen(const struct sk_buff *skb)
2358	{
2359	return skb->len - skb->data_len;
2360	}
2361
2362	static inline unsigned int __skb_pagelen(const struct sk_buff *skb)
2363	{
2364	unsigned int i, len = `0`;
2365
2366	for (i = skb_shinfo(skb)->nr_frags - `1`; (int)i >= `0`; i--)
2367	len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
2368	return len;
2369	}
2370
2371	static inline unsigned int skb_pagelen(const struct sk_buff *skb)
2372	{
2373	return skb_headlen(skb) + __skb_pagelen(skb);
2374	}
2375
2376	static inline void __skb_fill_page_desc_noacc(struct skb_shared_info *shinfo,
2377	int i, struct page *page,
2378	int off, int size)
2379	{
2380	skb_frag_t *frag = &shinfo->frags[i];
2381
2382	/*
2383	* Propagate page pfmemalloc to the skb if we can. The problem is
2384	* that not all callers have unique ownership of the page but rely
2385	* on page_is_pfmemalloc doing the right thing(tm).
2386	*/
2387	frag->bv_page = page;
2388	frag->bv_offset = off;
2389	skb_frag_size_set(frag, size);
2390	}
2391
2392	/**
2393	* skb_len_add - adds a number to len fields of skb
2394	* @skb: buffer to add len to
2395	* @delta: number of bytes to add
2396	*/
2397	static inline void skb_len_add(struct sk_buff skb, int* delta)
2398	{
2399	skb->len += delta;
2400	skb->data_len += delta;
2401	skb->truesize += delta;
2402	}
2403
2404	/**
2405	* __skb_fill_page_desc - initialise a paged fragment in an skb
2406	* @skb: buffer containing fragment to be initialised
2407	* @i: paged fragment index to initialise
2408	* @page: the page to use for this fragment
2409	* @off: the offset to the data with @page
2410	* @size: the length of the data
2411	*
2412	* Initialises the @i'th fragment of @skb to point to &size bytes at
2413	* offset @off within @page.
2414	*
2415	* Does not take any additional reference on the fragment.
2416	*/
2417	static inline void __skb_fill_page_desc(struct sk_buff skb, int* i,
2418	struct page page, int* off, int size)
2419	{
2420	__skb_fill_page_desc_noacc(skb_shinfo(skb), i, page, off, size);
2421	page = compound_head(page);
2422	if (page_is_pfmemalloc(page))
2423	skb->pfmemalloc = true;
2424	}
2425
2426	/**
2427	* skb_fill_page_desc - initialise a paged fragment in an skb
2428	* @skb: buffer containing fragment to be initialised
2429	* @i: paged fragment index to initialise
2430	* @page: the page to use for this fragment
2431	* @off: the offset to the data with @page
2432	* @size: the length of the data
2433	*
2434	* As per __skb_fill_page_desc() -- initialises the @i'th fragment of
2435	* @skb to point to @size bytes at offset @off within @page. In
2436	* addition updates @skb such that @i is the last fragment.
2437	*
2438	* Does not take any additional reference on the fragment.
2439	*/
2440	static inline void skb_fill_page_desc(struct sk_buff skb, int* i,
2441	struct page page, int* off, int size)
2442	{
2443	__skb_fill_page_desc(skb, i, page, off, size);
2444	skb_shinfo(skb)->nr_frags = i + `1`;
2445	}
2446
2447	void skb_add_rx_frag(struct sk_buff skb, int* i, struct page page, int* off,
2448	int size, unsigned int truesize);
2449
2450	void skb_coalesce_rx_frag(struct sk_buff skb, int* i, int size,
2451	unsigned int truesize);
2452
2453	#define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
2454
2455	#ifdef NET_SKBUFF_DATA_USES_OFFSET
2456	static inline unsigned char skb_tail_pointer(const* struct sk_buff *skb)
2457	{
2458	return skb->head + skb->tail;
2459	}
2460
2461	static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2462	{
2463	skb->tail = skb->data - skb->head;
2464	}
2465
2466	static inline void skb_set_tail_pointer(struct sk_buff skb, const* int offset)
2467	{
2468	skb_reset_tail_pointer(skb);
2469	skb->tail += offset;
2470	}
2471
2472	#else /* NET_SKBUFF_DATA_USES_OFFSET */
2473	static inline unsigned char skb_tail_pointer(const* struct sk_buff *skb)
2474	{
2475	return skb->tail;
2476	}
2477
2478	static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2479	{
2480	skb->tail = skb->data;
2481	}
2482
2483	static inline void skb_set_tail_pointer(struct sk_buff skb, const* int offset)
2484	{
2485	skb->tail = skb->data + offset;
2486	}
2487
2488	#endif /* NET_SKBUFF_DATA_USES_OFFSET */
2489
2490	static inline void skb_assert_len(struct sk_buff *skb)
2491	{
2492	#ifdef CONFIG_DEBUG_NET
2493	if (WARN_ONCE(!skb->len, "%s\n", __func__))
2494	DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
2495	#endif /* CONFIG_DEBUG_NET */
2496	}
2497
2498	/*
2499	* Add data to an sk_buff
2500	*/
2501	void pskb_put(struct* sk_buff skb, struct* sk_buff tail, int* len);
2502	void skb_put(struct* sk_buff skb, unsigned* int len);
2503	static inline void __skb_put(struct* sk_buff skb, unsigned* int len)
2504	{
2505	void *tmp = skb_tail_pointer(skb);
2506	SKB_LINEAR_ASSERT(skb);
2507	skb->tail += len;
2508	skb->len += len;
2509	return tmp;
2510	}
2511
2512	static inline void __skb_put_zero(struct* sk_buff skb, unsigned* int len)
2513	{
2514	void *tmp = __skb_put(skb, len);
2515
2516	memset(tmp, `0`, len);
2517	return tmp;
2518	}
2519
2520	static inline void __skb_put_data(struct* sk_buff skb, const* void *data,
2521	unsigned int len)
2522	{
2523	void *tmp = __skb_put(skb, len);
2524
2525	memcpy(tmp, data, len);
2526	return tmp;
2527	}
2528
2529	static inline void __skb_put_u8(struct sk_buff *skb, u8 val)
2530	{
2531	(u8 )__skb_put(skb, `1`) = val;
2532	}
2533
2534	static inline void skb_put_zero(struct* sk_buff skb, unsigned* int len)
2535	{
2536	void *tmp = skb_put(skb, len);
2537
2538	memset(tmp, `0`, len);
2539
2540	return tmp;
2541	}
2542
2543	static inline void skb_put_data(struct* sk_buff skb, const* void *data,
2544	unsigned int len)
2545	{
2546	void *tmp = skb_put(skb, len);
2547
2548	memcpy(tmp, data, len);
2549
2550	return tmp;
2551	}
2552
2553	static inline void skb_put_u8(struct sk_buff *skb, u8 val)
2554	{
2555	(u8 )skb_put(skb, `1`) = val;
2556	}
2557
2558	void skb_push(struct* sk_buff skb, unsigned* int len);
2559	static inline void __skb_push(struct* sk_buff skb, unsigned* int len)
2560	{
2561	skb->data -= len;
2562	skb->len += len;
2563	return skb->data;
2564	}
2565
2566	void skb_pull(struct* sk_buff skb, unsigned* int len);
2567	static inline void __skb_pull(struct* sk_buff skb, unsigned* int len)
2568	{
2569	skb->len -= len;
2570	if (unlikely(skb->len < skb->data_len)) {
2571	#if defined(CONFIG_DEBUG_NET)
2572	skb->len += len;
2573	pr_err("__skb_pull(len=%u)\n", len);
2574	skb_dump(KERN_ERR, skb, false);
2575	#endif
2576	BUG();
2577	}
2578	return skb->data += len;
2579	}
2580
2581	static inline void skb_pull_inline(struct* sk_buff skb, unsigned* int len)
2582	{
2583	return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
2584	}
2585
2586	void skb_pull_data(struct* sk_buff *skb, size_t len);
2587
2588	void __pskb_pull_tail(struct* sk_buff skb, int* delta);
2589
2590	static inline void __pskb_pull(struct* sk_buff skb, unsigned* int len)
2591	{
2592	if (len > skb_headlen(skb) &&
2593	!__pskb_pull_tail(skb, len - skb_headlen(skb)))
2594	return NULL;
2595	skb->len -= len;
2596	return skb->data += len;
2597	}
2598
2599	static inline void pskb_pull(struct* sk_buff skb, unsigned* int len)
2600	{
2601	return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
2602	}
2603
2604	static inline bool pskb_may_pull(struct sk_buff skb, unsigned* int len)
2605	{
2606	if (likely(len <= skb_headlen(skb)))
2607	return true;
2608	if (unlikely(len > skb->len))
2609	return false;
2610	return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
2611	}
2612
2613	void skb_condense(struct sk_buff *skb);
2614
2615	/**
2616	* skb_headroom - bytes at buffer head
2617	* @skb: buffer to check
2618	*
2619	* Return the number of bytes of free space at the head of an &sk_buff.
2620	*/
2621	static inline unsigned int skb_headroom(const struct sk_buff *skb)
2622	{
2623	return skb->data - skb->head;
2624	}
2625
2626	/**
2627	* skb_tailroom - bytes at buffer end
2628	* @skb: buffer to check
2629	*
2630	* Return the number of bytes of free space at the tail of an sk_buff
2631	*/
2632	static inline int skb_tailroom(const struct sk_buff *skb)
2633	{
2634	return skb_is_nonlinear(skb) ? `0` : skb->end - skb->tail;
2635	}
2636
2637	/**
2638	* skb_availroom - bytes at buffer end
2639	* @skb: buffer to check
2640	*
2641	* Return the number of bytes of free space at the tail of an sk_buff
2642	* allocated by sk_stream_alloc()
2643	*/
2644	static inline int skb_availroom(const struct sk_buff *skb)
2645	{
2646	if (skb_is_nonlinear(skb))
2647	return `0`;
2648
2649	return skb->end - skb->tail - skb->reserved_tailroom;
2650	}
2651
2652	/**
2653	* skb_reserve - adjust headroom
2654	* @skb: buffer to alter
2655	* @len: bytes to move
2656	*
2657	* Increase the headroom of an empty &sk_buff by reducing the tail
2658	* room. This is only allowed for an empty buffer.
2659	*/
2660	static inline void skb_reserve(struct sk_buff skb, int* len)
2661	{
2662	skb->data += len;
2663	skb->tail += len;
2664	}
2665
2666	/**
2667	* skb_tailroom_reserve - adjust reserved_tailroom
2668	* @skb: buffer to alter
2669	* @mtu: maximum amount of headlen permitted
2670	* @needed_tailroom: minimum amount of reserved_tailroom
2671	*
2672	* Set reserved_tailroom so that headlen can be as large as possible but
2673	* not larger than mtu and tailroom cannot be smaller than
2674	* needed_tailroom.
2675	* The required headroom should already have been reserved before using
2676	* this function.
2677	*/
2678	static inline void skb_tailroom_reserve(struct sk_buff skb, unsigned* int mtu,
2679	unsigned int needed_tailroom)
2680	{
2681	SKB_LINEAR_ASSERT(skb);
2682	if (mtu < skb_tailroom(skb) - needed_tailroom)
2683	/ use at most mtu /
2684	skb->reserved_tailroom = skb_tailroom(skb) - mtu;
2685	else
2686	/ use up to all available space /
2687	skb->reserved_tailroom = needed_tailroom;
2688	}
2689
2690	#define ENCAP_TYPE_ETHER 0
2691	#define ENCAP_TYPE_IPPROTO 1
2692
2693	static inline void skb_set_inner_protocol(struct sk_buff *skb,
2694	__be16 protocol)
2695	{
2696	skb->inner_protocol = protocol;
2697	skb->inner_protocol_type = ENCAP_TYPE_ETHER;
2698	}
2699
2700	static inline void skb_set_inner_ipproto(struct sk_buff *skb,
2701	__u8 ipproto)
2702	{
2703	skb->inner_ipproto = ipproto;
2704	skb->inner_protocol_type = ENCAP_TYPE_IPPROTO;
2705	}
2706
2707	static inline void skb_reset_inner_headers(struct sk_buff *skb)
2708	{
2709	skb->inner_mac_header = skb->mac_header;
2710	skb->inner_network_header = skb->network_header;
2711	skb->inner_transport_header = skb->transport_header;
2712	}
2713
2714	static inline void skb_reset_mac_len(struct sk_buff *skb)
2715	{
2716	skb->mac_len = skb->network_header - skb->mac_header;
2717	}
2718
2719	static inline unsigned char skb_inner_transport_header(const* struct sk_buff
2720	*skb)
2721	{
2722	return skb->head + skb->inner_transport_header;
2723	}
2724
2725	static inline int skb_inner_transport_offset(const struct sk_buff *skb)
2726	{
2727	return skb_inner_transport_header(skb) - skb->data;
2728	}
2729
2730	static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
2731	{
2732	skb->inner_transport_header = skb->data - skb->head;
2733	}
2734
2735	static inline void skb_set_inner_transport_header(struct sk_buff *skb,
2736	const int offset)
2737	{
2738	skb_reset_inner_transport_header(skb);
2739	skb->inner_transport_header += offset;
2740	}
2741
2742	static inline unsigned char skb_inner_network_header(const* struct sk_buff *skb)
2743	{
2744	return skb->head + skb->inner_network_header;
2745	}
2746
2747	static inline void skb_reset_inner_network_header(struct sk_buff *skb)
2748	{
2749	skb->inner_network_header = skb->data - skb->head;
2750	}
2751
2752	static inline void skb_set_inner_network_header(struct sk_buff *skb,
2753	const int offset)
2754	{
2755	skb_reset_inner_network_header(skb);
2756	skb->inner_network_header += offset;
2757	}
2758
2759	static inline unsigned char skb_inner_mac_header(const* struct sk_buff *skb)
2760	{
2761	return skb->head + skb->inner_mac_header;
2762	}
2763
2764	static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
2765	{
2766	skb->inner_mac_header = skb->data - skb->head;
2767	}
2768
2769	static inline void skb_set_inner_mac_header(struct sk_buff *skb,
2770	const int offset)
2771	{
2772	skb_reset_inner_mac_header(skb);
2773	skb->inner_mac_header += offset;
2774	}
2775	static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
2776	{
2777	return skb->transport_header != (typeof(skb->transport_header))~`0U`;
2778	}
2779
2780	static inline unsigned char skb_transport_header(const* struct sk_buff *skb)
2781	{
2782	DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb));
2783	return skb->head + skb->transport_header;
2784	}
2785
2786	static inline void skb_reset_transport_header(struct sk_buff *skb)
2787	{
2788	skb->transport_header = skb->data - skb->head;
2789	}
2790
2791	static inline void skb_set_transport_header(struct sk_buff *skb,
2792	const int offset)
2793	{
2794	skb_reset_transport_header(skb);
2795	skb->transport_header += offset;
2796	}
2797
2798	static inline unsigned char skb_network_header(const* struct sk_buff *skb)
2799	{
2800	return skb->head + skb->network_header;
2801	}
2802
2803	static inline void skb_reset_network_header(struct sk_buff *skb)
2804	{
2805	skb->network_header = skb->data - skb->head;
2806	}
2807
2808	static inline void skb_set_network_header(struct sk_buff skb, const* int offset)
2809	{
2810	skb_reset_network_header(skb);
2811	skb->network_header += offset;
2812	}
2813
2814	static inline int skb_mac_header_was_set(const struct sk_buff *skb)
2815	{
2816	return skb->mac_header != (typeof(skb->mac_header))~`0U`;
2817	}
2818
2819	static inline unsigned char skb_mac_header(const* struct sk_buff *skb)
2820	{
2821	DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb));
2822	return skb->head + skb->mac_header;
2823	}
2824
2825	static inline int skb_mac_offset(const struct sk_buff *skb)
2826	{
2827	return skb_mac_header(skb) - skb->data;
2828	}
2829
2830	static inline u32 skb_mac_header_len(const struct sk_buff *skb)
2831	{
2832	DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb));
2833	return skb->network_header - skb->mac_header;
2834	}
2835
2836	static inline void skb_unset_mac_header(struct sk_buff *skb)
2837	{
2838	skb->mac_header = (typeof(skb->mac_header))~`0U`;
2839	}
2840
2841	static inline void skb_reset_mac_header(struct sk_buff *skb)
2842	{
2843	skb->mac_header = skb->data - skb->head;
2844	}
2845
2846	static inline void skb_set_mac_header(struct sk_buff skb, const* int offset)
2847	{
2848	skb_reset_mac_header(skb);
2849	skb->mac_header += offset;
2850	}
2851
2852	static inline void skb_pop_mac_header(struct sk_buff *skb)
2853	{
2854	skb->mac_header = skb->network_header;
2855	}
2856
2857	static inline void skb_probe_transport_header(struct sk_buff *skb)
2858	{
2859	struct flow_keys_basic keys;
2860
2861	if (skb_transport_header_was_set(skb))
2862	return;
2863
2864	if (skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
2865	NULL, `0`, `0`, `0`, `0`))
2866	skb_set_transport_header(skb, keys.control.thoff);
2867	}
2868
2869	static inline void skb_mac_header_rebuild(struct sk_buff *skb)
2870	{
2871	if (skb_mac_header_was_set(skb)) {
2872	const unsigned char *old_mac = skb_mac_header(skb);
2873
2874	skb_set_mac_header(skb, -skb->mac_len);
2875	memmove(skb_mac_header(skb), old_mac, skb->mac_len);
2876	}
2877	}
2878
2879	static inline int skb_checksum_start_offset(const struct sk_buff *skb)
2880	{
2881	return skb->csum_start - skb_headroom(skb);
2882	}
2883
2884	static inline unsigned char skb_checksum_start(const* struct sk_buff *skb)
2885	{
2886	return skb->head + skb->csum_start;
2887	}
2888
2889	static inline int skb_transport_offset(const struct sk_buff *skb)
2890	{
2891	return skb_transport_header(skb) - skb->data;
2892	}
2893
2894	static inline u32 skb_network_header_len(const struct sk_buff *skb)
2895	{
2896	return skb->transport_header - skb->network_header;
2897	}
2898
2899	static inline u32 skb_inner_network_header_len(const struct sk_buff *skb)
2900	{
2901	return skb->inner_transport_header - skb->inner_network_header;
2902	}
2903
2904	static inline int skb_network_offset(const struct sk_buff *skb)
2905	{
2906	return skb_network_header(skb) - skb->data;
2907	}
2908
2909	static inline int skb_inner_network_offset(const struct sk_buff *skb)
2910	{
2911	return skb_inner_network_header(skb) - skb->data;
2912	}
2913
2914	static inline int pskb_network_may_pull(struct sk_buff skb, unsigned* int len)
2915	{
2916	return pskb_may_pull(skb, skb_network_offset(skb) + len);
2917	}
2918
2919	/*
2920	* CPUs often take a performance hit when accessing unaligned memory
2921	* locations. The actual performance hit varies, it can be small if the
2922	* hardware handles it or large if we have to take an exception and fix it
2923	* in software.
2924	*
2925	* Since an ethernet header is 14 bytes network drivers often end up with
2926	* the IP header at an unaligned offset. The IP header can be aligned by
2927	* shifting the start of the packet by 2 bytes. Drivers should do this
2928	* with:
2929	*
2930	* skb_reserve(skb, NET_IP_ALIGN);
2931	*
2932	* The downside to this alignment of the IP header is that the DMA is now
2933	* unaligned. On some architectures the cost of an unaligned DMA is high
2934	* and this cost outweighs the gains made by aligning the IP header.
2935	*
2936	* Since this trade off varies between architectures, we allow NET_IP_ALIGN
2937	* to be overridden.
2938	*/
2939	#ifndef NET_IP_ALIGN
2940	#define NET_IP_ALIGN 2
2941	#endif
2942
2943	/*
2944	* The networking layer reserves some headroom in skb data (via
2945	* dev_alloc_skb). This is used to avoid having to reallocate skb data when
2946	* the header has to grow. In the default case, if the header has to grow
2947	* 32 bytes or less we avoid the reallocation.
2948	*
2949	* Unfortunately this headroom changes the DMA alignment of the resulting
2950	* network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
2951	* on some architectures. An architecture can override this value,
2952	* perhaps setting it to a cacheline in size (since that will maintain
2953	* cacheline alignment of the DMA). It must be a power of 2.
2954	*
2955	* Various parts of the networking layer expect at least 32 bytes of
2956	* headroom, you should not reduce this.
2957	*
2958	* Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
2959	* to reduce average number of cache lines per packet.
2960	* get_rps_cpu() for example only access one 64 bytes aligned block :
2961	* NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
2962	*/
2963	#ifndef NET_SKB_PAD
2964	#define NET_SKB_PAD max(32, L1_CACHE_BYTES)
2965	#endif
2966
2967	int ___pskb_trim(struct sk_buff skb, unsigned* int len);
2968
2969	static inline void __skb_set_length(struct sk_buff skb, unsigned* int len)
2970	{
2971	if (WARN_ON(skb_is_nonlinear(skb)))
2972	return;
2973	skb->len = len;
2974	skb_set_tail_pointer(skb, len);
2975	}
2976
2977	static inline void __skb_trim(struct sk_buff skb, unsigned* int len)
2978	{
2979	__skb_set_length(skb, len);
2980	}
2981
2982	void skb_trim(struct sk_buff skb, unsigned* int len);
2983
2984	static inline int __pskb_trim(struct sk_buff skb, unsigned* int len)
2985	{
2986	if (skb->data_len)
2987	return ___pskb_trim(skb, len);
2988	__skb_trim(skb, len);
2989	return `0`;
2990	}
2991
2992	static inline int pskb_trim(struct sk_buff skb, unsigned* int len)
2993	{
2994	return (len < skb->len) ? __pskb_trim(skb, len) : `0`;
2995	}
2996
2997	/**
2998	* pskb_trim_unique - remove end from a paged unique (not cloned) buffer
2999	* @skb: buffer to alter
3000	* @len: new length
3001	*
3002	* This is identical to pskb_trim except that the caller knows that
3003	* the skb is not cloned so we should never get an error due to out-
3004	* of-memory.
3005	*/
3006	static inline void pskb_trim_unique(struct sk_buff skb, unsigned* int len)
3007	{
3008	int err = pskb_trim(skb, len);
3009	BUG_ON(err);
3010	}
3011
3012	static inline int __skb_grow(struct sk_buff skb, unsigned* int len)
3013	{
3014	unsigned int diff = len - skb->len;
3015
3016	if (skb_tailroom(skb) < diff) {
3017	int ret = pskb_expand_head(skb, `0`, diff - skb_tailroom(skb),
3018	GFP_ATOMIC);
3019	if (ret)
3020	return ret;
3021	}
3022	__skb_set_length(skb, len);
3023	return `0`;
3024	}
3025
3026	/**
3027	* skb_orphan - orphan a buffer
3028	* @skb: buffer to orphan
3029	*
3030	* If a buffer currently has an owner then we call the owner's
3031	* destructor function and make the @skb unowned. The buffer continues
3032	* to exist but is no longer charged to its former owner.
3033	*/
3034	static inline void skb_orphan(struct sk_buff *skb)
3035	{
3036	if (skb->destructor) {
3037	skb->destructor(skb);
3038	skb->destructor = NULL;
3039	skb->sk = NULL;
3040	} else {
3041	BUG_ON(skb->sk);
3042	}
3043	}
3044
3045	/**
3046	* skb_orphan_frags - orphan the frags contained in a buffer
3047	* @skb: buffer to orphan frags from
3048	* @gfp_mask: allocation mask for replacement pages
3049	*
3050	* For each frag in the SKB which needs a destructor (i.e. has an
3051	* owner) create a copy of that frag and release the original
3052	* page by calling the destructor.
3053	*/
3054	static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
3055	{
3056	if (likely(!skb_zcopy(skb)))
3057	return `0`;
3058	if (skb_shinfo(skb)->flags & SKBFL_DONT_ORPHAN)
3059	return `0`;
3060	return skb_copy_ubufs(skb, gfp_mask);
3061	}
3062
3063	/ Frags must be orphaned, even if refcounted, if skb might loop to rx path /
3064	static inline int skb_orphan_frags_rx(struct sk_buff *skb, gfp_t gfp_mask)
3065	{
3066	if (likely(!skb_zcopy(skb)))
3067	return `0`;
3068	return skb_copy_ubufs(skb, gfp_mask);
3069	}
3070
3071	/**
3072	* __skb_queue_purge - empty a list
3073	* @list: list to empty
3074	*
3075	* Delete all buffers on an &sk_buff list. Each buffer is removed from
3076	* the list and one reference dropped. This function does not take the
3077	* list lock and the caller must hold the relevant locks to use it.
3078	*/
3079	static inline void __skb_queue_purge(struct sk_buff_head *list)
3080	{
3081	struct sk_buff *skb;
3082	while ((skb = __skb_dequeue(list)) != NULL)
3083	kfree_skb(skb);
3084	}
3085	void skb_queue_purge(struct sk_buff_head *list);
3086
3087	unsigned int skb_rbtree_purge(struct rb_root *root);
3088
3089	void __netdev_alloc_frag_align(unsigned* int fragsz, unsigned int align_mask);
3090
3091	/**
3092	* netdev_alloc_frag - allocate a page fragment
3093	* @fragsz: fragment size
3094	*
3095	* Allocates a frag from a page for receive buffer.
3096	* Uses GFP_ATOMIC allocations.
3097	*/
3098	static inline void netdev_alloc_frag(unsigned* int fragsz)
3099	{
3100	return __netdev_alloc_frag_align(fragsz, ~`0u`);
3101	}
3102
3103	static inline void netdev_alloc_frag_align(unsigned* int fragsz,
3104	unsigned int align)
3105	{
3106	WARN_ON_ONCE(!is_power_of_2(align));
3107	return __netdev_alloc_frag_align(fragsz, -align);
3108	}
3109
3110	struct sk_buff __netdev_alloc_skb(struct* net_device dev, unsigned* int length,
3111	gfp_t gfp_mask);
3112
3113	/**
3114	* netdev_alloc_skb - allocate an skbuff for rx on a specific device
3115	* @dev: network device to receive on
3116	* @length: length to allocate
3117	*
3118	* Allocate a new &sk_buff and assign it a usage count of one. The
3119	* buffer has unspecified headroom built in. Users should allocate
3120	* the headroom they think they need without accounting for the
3121	* built in space. The built in space is used for optimisations.
3122	*
3123	* %NULL is returned if there is no free memory. Although this function
3124	* allocates memory it can be called from an interrupt.
3125	*/
3126	static inline struct sk_buff netdev_alloc_skb(struct* net_device *dev,
3127	unsigned int length)
3128	{
3129	return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
3130	}
3131
3132	/ legacy helper around __netdev_alloc_skb() /
3133	static inline struct sk_buff __dev_alloc_skb(unsigned* int length,
3134	gfp_t gfp_mask)
3135	{
3136	return __netdev_alloc_skb(NULL, length, gfp_mask);
3137	}
3138
3139	/ legacy helper around netdev_alloc_skb() /
3140	static inline struct sk_buff dev_alloc_skb(unsigned* int length)
3141	{
3142	return netdev_alloc_skb(NULL, length);
3143	}
3144
3145
3146	static inline struct sk_buff __netdev_alloc_skb_ip_align(struct* net_device *dev,
3147	unsigned int length, gfp_t gfp)
3148	{
3149	struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
3150
3151	if (NET_IP_ALIGN && skb)
3152	skb_reserve(skb, NET_IP_ALIGN);
3153	return skb;
3154	}
3155
3156	static inline struct sk_buff netdev_alloc_skb_ip_align(struct* net_device *dev,
3157	unsigned int length)
3158	{
3159	return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
3160	}
3161
3162	static inline void skb_free_frag(void *addr)
3163	{
3164	page_frag_free(addr);
3165	}
3166
3167	void __napi_alloc_frag_align(unsigned* int fragsz, unsigned int align_mask);
3168
3169	static inline void napi_alloc_frag(unsigned* int fragsz)
3170	{
3171	return __napi_alloc_frag_align(fragsz, ~`0u`);
3172	}
3173
3174	static inline void napi_alloc_frag_align(unsigned* int fragsz,
3175	unsigned int align)
3176	{
3177	WARN_ON_ONCE(!is_power_of_2(align));
3178	return __napi_alloc_frag_align(fragsz, -align);
3179	}
3180
3181	struct sk_buff __napi_alloc_skb(struct* napi_struct *napi,
3182	unsigned int length, gfp_t gfp_mask);
3183	static inline struct sk_buff napi_alloc_skb(struct* napi_struct *napi,
3184	unsigned int length)
3185	{
3186	return __napi_alloc_skb(napi, length, GFP_ATOMIC);
3187	}
3188	void napi_consume_skb(struct sk_buff skb, int* budget);
3189
3190	void napi_skb_free_stolen_head(struct sk_buff *skb);
3191	void __kfree_skb_defer(struct sk_buff *skb);
3192
3193	/**
3194	* __dev_alloc_pages - allocate page for network Rx
3195	* @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
3196	* @order: size of the allocation
3197	*
3198	* Allocate a new page.
3199	*
3200	* %NULL is returned if there is no free memory.
3201	*/
3202	static inline struct page *__dev_alloc_pages(gfp_t gfp_mask,
3203	unsigned int order)
3204	{
3205	/ This piece of code contains several assumptions.*
3206	* 1. This is for device Rx, therefor a cold page is preferred.
3207	* 2. The expectation is the user wants a compound page.
3208	* 3. If requesting a order 0 page it will not be compound
3209	* due to the check to see if order has a value in prep_new_page
3210	* 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
3211	* code in gfp_to_alloc_flags that should be enforcing this.
3212	*/
3213	gfp_mask \|= __GFP_COMP \| __GFP_MEMALLOC;
3214
3215	return alloc_pages_node(NUMA_NO_NODE, gfp_mask, order);
3216	}
3217
3218	static inline struct page dev_alloc_pages(unsigned* int order)
3219	{
3220	return __dev_alloc_pages(GFP_ATOMIC \| __GFP_NOWARN, order);
3221	}
3222
3223	/**
3224	* __dev_alloc_page - allocate a page for network Rx
3225	* @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
3226	*
3227	* Allocate a new page.
3228	*
3229	* %NULL is returned if there is no free memory.
3230	*/
3231	static inline struct page *__dev_alloc_page(gfp_t gfp_mask)
3232	{
3233	return __dev_alloc_pages(gfp_mask, `0`);
3234	}
3235
3236	static inline struct page dev_alloc_page(void*)
3237	{
3238	return dev_alloc_pages(`0`);
3239	}
3240
3241	/**
3242	* dev_page_is_reusable - check whether a page can be reused for network Rx
3243	* @page: the page to test
3244	*
3245	* A page shouldn't be considered for reusing/recycling if it was allocated
3246	* under memory pressure or at a distant memory node.
3247	*
3248	* Returns false if this page should be returned to page allocator, true
3249	* otherwise.
3250	*/
3251	static inline bool dev_page_is_reusable(const struct page *page)
3252	{
3253	return likely(page_to_nid(page) == numa_mem_id() &&
3254	!page_is_pfmemalloc(page));
3255	}
3256
3257	/**
3258	* skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
3259	* @page: The page that was allocated from skb_alloc_page
3260	* @skb: The skb that may need pfmemalloc set
3261	*/
3262	static inline void skb_propagate_pfmemalloc(const struct page *page,
3263	struct sk_buff *skb)
3264	{
3265	if (page_is_pfmemalloc(page))
3266	skb->pfmemalloc = true;
3267	}
3268
3269	/**
3270	* skb_frag_off() - Returns the offset of a skb fragment
3271	* @frag: the paged fragment
3272	*/
3273	static inline unsigned int skb_frag_off(const skb_frag_t *frag)
3274	{
3275	return frag->bv_offset;
3276	}
3277
3278	/**
3279	* skb_frag_off_add() - Increments the offset of a skb fragment by @delta
3280	* @frag: skb fragment
3281	* @delta: value to add
3282	*/
3283	static inline void skb_frag_off_add(skb_frag_t frag, int* delta)
3284	{
3285	frag->bv_offset += delta;
3286	}
3287
3288	/**
3289	* skb_frag_off_set() - Sets the offset of a skb fragment
3290	* @frag: skb fragment
3291	* @offset: offset of fragment
3292	*/
3293	static inline void skb_frag_off_set(skb_frag_t frag, unsigned* int offset)
3294	{
3295	frag->bv_offset = offset;
3296	}
3297
3298	/**
3299	* skb_frag_off_copy() - Sets the offset of a skb fragment from another fragment
3300	* @fragto: skb fragment where offset is set
3301	* @fragfrom: skb fragment offset is copied from
3302	*/
3303	static inline void skb_frag_off_copy(skb_frag_t *fragto,
3304	const skb_frag_t *fragfrom)
3305	{
3306	fragto->bv_offset = fragfrom->bv_offset;
3307	}
3308
3309	/**
3310	* skb_frag_page - retrieve the page referred to by a paged fragment
3311	* @frag: the paged fragment
3312	*
3313	* Returns the &struct page associated with @frag.
3314	*/
3315	static inline struct page skb_frag_page(const* skb_frag_t *frag)
3316	{
3317	return frag->bv_page;
3318	}
3319
3320	/**
3321	* __skb_frag_ref - take an addition reference on a paged fragment.
3322	* @frag: the paged fragment
3323	*
3324	* Takes an additional reference on the paged fragment @frag.
3325	*/
3326	static inline void __skb_frag_ref(skb_frag_t *frag)
3327	{
3328	get_page(skb_frag_page(frag));
3329	}
3330
3331	/**
3332	* skb_frag_ref - take an addition reference on a paged fragment of an skb.
3333	* @skb: the buffer
3334	* @f: the fragment offset.
3335	*
3336	* Takes an additional reference on the @f'th paged fragment of @skb.
3337	*/
3338	static inline void skb_frag_ref(struct sk_buff skb, int* f)
3339	{
3340	__skb_frag_ref(&skb_shinfo(skb)->frags[f]);
3341	}
3342
3343	/**
3344	* __skb_frag_unref - release a reference on a paged fragment.
3345	* @frag: the paged fragment
3346	* @recycle: recycle the page if allocated via page_pool
3347	*
3348	* Releases a reference on the paged fragment @frag
3349	* or recycles the page via the page_pool API.
3350	*/
3351	static inline void __skb_frag_unref(skb_frag_t *frag, bool recycle)
3352	{
3353	struct page *page = skb_frag_page(frag);
3354
3355	#ifdef CONFIG_PAGE_POOL
3356	if (recycle && page_pool_return_skb_page(page))
3357	return;
3358	#endif
3359	put_page(page);
3360	}
3361
3362	/**
3363	* skb_frag_unref - release a reference on a paged fragment of an skb.
3364	* @skb: the buffer
3365	* @f: the fragment offset
3366	*
3367	* Releases a reference on the @f'th paged fragment of @skb.
3368	*/
3369	static inline void skb_frag_unref(struct sk_buff skb, int* f)
3370	{
3371	struct skb_shared_info *shinfo = skb_shinfo(skb);
3372
3373	if (!skb_zcopy_managed(skb))
3374	__skb_frag_unref(&shinfo->frags[f], skb->pp_recycle);
3375	}
3376
3377	/**
3378	* skb_frag_address - gets the address of the data contained in a paged fragment
3379	* @frag: the paged fragment buffer
3380	*
3381	* Returns the address of the data within @frag. The page must already
3382	* be mapped.
3383	*/
3384	static inline void skb_frag_address(const* skb_frag_t *frag)
3385	{
3386	return page_address(skb_frag_page(frag)) + skb_frag_off(frag);
3387	}
3388
3389	/**
3390	* skb_frag_address_safe - gets the address of the data contained in a paged fragment
3391	* @frag: the paged fragment buffer
3392	*
3393	* Returns the address of the data within @frag. Checks that the page
3394	* is mapped and returns %NULL otherwise.
3395	*/
3396	static inline void skb_frag_address_safe(const* skb_frag_t *frag)
3397	{
3398	void *ptr = page_address(skb_frag_page(frag));
3399	if (unlikely(!ptr))
3400	return NULL;
3401
3402	return ptr + skb_frag_off(frag);
3403	}
3404
3405	/**
3406	* skb_frag_page_copy() - sets the page in a fragment from another fragment
3407	* @fragto: skb fragment where page is set
3408	* @fragfrom: skb fragment page is copied from
3409	*/
3410	static inline void skb_frag_page_copy(skb_frag_t *fragto,
3411	const skb_frag_t *fragfrom)
3412	{
3413	fragto->bv_page = fragfrom->bv_page;
3414	}
3415
3416	/**
3417	* __skb_frag_set_page - sets the page contained in a paged fragment
3418	* @frag: the paged fragment
3419	* @page: the page to set
3420	*
3421	* Sets the fragment @frag to contain @page.
3422	*/
3423	static inline void __skb_frag_set_page(skb_frag_t frag, struct* page *page)
3424	{
3425	frag->bv_page = page;
3426	}
3427
3428	/**
3429	* skb_frag_set_page - sets the page contained in a paged fragment of an skb
3430	* @skb: the buffer
3431	* @f: the fragment offset
3432	* @page: the page to set
3433	*
3434	* Sets the @f'th fragment of @skb to contain @page.
3435	*/
3436	static inline void skb_frag_set_page(struct sk_buff skb, int* f,
3437	struct page *page)
3438	{
3439	__skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
3440	}
3441
3442	bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio);
3443
3444	/**
3445	* skb_frag_dma_map - maps a paged fragment via the DMA API
3446	* @dev: the device to map the fragment to
3447	* @frag: the paged fragment to map
3448	* @offset: the offset within the fragment (starting at the
3449	* fragment's own offset)
3450	* @size: the number of bytes to map
3451	* @dir: the direction of the mapping (``PCI_DMA_*``)
3452	*
3453	* Maps the page associated with @frag to @device.
3454	*/
3455	static inline dma_addr_t skb_frag_dma_map(struct device *dev,
3456	const skb_frag_t *frag,
3457	size_t offset, size_t size,
3458	enum dma_data_direction dir)
3459	{
3460	return dma_map_page(dev, skb_frag_page(frag),
3461	skb_frag_off(frag) + offset, size, dir);
3462	}
3463
3464	static inline struct sk_buff pskb_copy(struct* sk_buff *skb,
3465	gfp_t gfp_mask)
3466	{
3467	return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
3468	}
3469
3470
3471	static inline struct sk_buff pskb_copy_for_clone(struct* sk_buff *skb,
3472	gfp_t gfp_mask)
3473	{
3474	return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true);
3475	}
3476
3477
3478	/**
3479	* skb_clone_writable - is the header of a clone writable
3480	* @skb: buffer to check
3481	* @len: length up to which to write
3482	*
3483	* Returns true if modifying the header part of the cloned buffer
3484	* does not requires the data to be copied.
3485	*/
3486	static inline int skb_clone_writable(const struct sk_buff skb, unsigned* int len)
3487	{
3488	return !skb_header_cloned(skb) &&
3489	skb_headroom(skb) + len <= skb->hdr_len;
3490	}
3491
3492	static inline int skb_try_make_writable(struct sk_buff *skb,
3493	unsigned int write_len)
3494	{
3495	return skb_cloned(skb) && !skb_clone_writable(skb, write_len) &&
3496	pskb_expand_head(skb, `0`, `0`, GFP_ATOMIC);
3497	}
3498
3499	static inline int __skb_cow(struct sk_buff skb, unsigned* int headroom,
3500	int cloned)
3501	{
3502	int delta = `0`;
3503
3504	if (headroom > skb_headroom(skb))
3505	delta = headroom - skb_headroom(skb);
3506
3507	if (delta \|\| cloned)
3508	return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), `0`,
3509	GFP_ATOMIC);
3510	return `0`;
3511	}
3512
3513	/**
3514	* skb_cow - copy header of skb when it is required
3515	* @skb: buffer to cow
3516	* @headroom: needed headroom
3517	*
3518	* If the skb passed lacks sufficient headroom or its data part
3519	* is shared, data is reallocated. If reallocation fails, an error
3520	* is returned and original skb is not changed.
3521	*
3522	* The result is skb with writable area skb->head...skb->tail
3523	* and at least @headroom of space at head.
3524	*/
3525	static inline int skb_cow(struct sk_buff skb, unsigned* int headroom)
3526	{
3527	return __skb_cow(skb, headroom, skb_cloned(skb));
3528	}
3529
3530	/**
3531	* skb_cow_head - skb_cow but only making the head writable
3532	* @skb: buffer to cow
3533	* @headroom: needed headroom
3534	*
3535	* This function is identical to skb_cow except that we replace the
3536	* skb_cloned check by skb_header_cloned. It should be used when
3537	* you only need to push on some header and do not need to modify
3538	* the data.
3539	*/
3540	static inline int skb_cow_head(struct sk_buff skb, unsigned* int headroom)
3541	{
3542	return __skb_cow(skb, headroom, skb_header_cloned(skb));
3543	}
3544
3545	/**
3546	* skb_padto - pad an skbuff up to a minimal size
3547	* @skb: buffer to pad
3548	* @len: minimal length
3549	*
3550	* Pads up a buffer to ensure the trailing bytes exist and are
3551	* blanked. If the buffer already contains sufficient data it
3552	* is untouched. Otherwise it is extended. Returns zero on
3553	* success. The skb is freed on error.
3554	*/
3555	static inline int skb_padto(struct sk_buff skb, unsigned* int len)
3556	{
3557	unsigned int size = skb->len;
3558	if (likely(size >= len))
3559	return `0`;
3560	return skb_pad(skb, len - size);
3561	}
3562
3563	/**
3564	* __skb_put_padto - increase size and pad an skbuff up to a minimal size
3565	* @skb: buffer to pad
3566	* @len: minimal length
3567	* @free_on_error: free buffer on error
3568	*
3569	* Pads up a buffer to ensure the trailing bytes exist and are
3570	* blanked. If the buffer already contains sufficient data it
3571	* is untouched. Otherwise it is extended. Returns zero on
3572	* success. The skb is freed on error if @free_on_error is true.
3573	*/
3574	static inline int __must_check __skb_put_padto(struct sk_buff *skb,
3575	unsigned int len,
3576	bool free_on_error)
3577	{
3578	unsigned int size = skb->len;
3579
3580	if (unlikely(size < len)) {
3581	len -= size;
3582	if (__skb_pad(skb, len, free_on_error))
3583	return -ENOMEM;
3584	__skb_put(skb, len);
3585	}
3586	return `0`;
3587	}
3588
3589	/**
3590	* skb_put_padto - increase size and pad an skbuff up to a minimal size
3591	* @skb: buffer to pad
3592	* @len: minimal length
3593	*
3594	* Pads up a buffer to ensure the trailing bytes exist and are
3595	* blanked. If the buffer already contains sufficient data it
3596	* is untouched. Otherwise it is extended. Returns zero on
3597	* success. The skb is freed on error.
3598	*/
3599	static inline int __must_check skb_put_padto(struct sk_buff skb, unsigned* int len)
3600	{
3601	return __skb_put_padto(skb, len, true);
3602	}
3603
3604	static inline int skb_add_data(struct sk_buff *skb,
3605	struct iov_iter from, int* copy)
3606	{
3607	const int off = skb->len;
3608
3609	if (skb->ip_summed == CHECKSUM_NONE) {
3610	__wsum csum = `0`;
3611	if (csum_and_copy_from_iter_full(skb_put(skb, copy), copy,
3612	&csum, from)) {
3613	skb->csum = csum_block_add(skb->csum, csum, off);
3614	return `0`;
3615	}
3616	} else if (copy_from_iter_full(skb_put(skb, copy), copy, from))
3617	return `0`;
3618
3619	__skb_trim(skb, off);
3620	return -EFAULT;
3621	}
3622
3623	static inline bool skb_can_coalesce(struct sk_buff skb, int* i,
3624	const struct page page, int* off)
3625	{
3626	if (skb_zcopy(skb))
3627	return false;
3628	if (i) {
3629	const skb_frag_t *frag = &skb_shinfo(skb)->frags[i - `1`];
3630
3631	return page == skb_frag_page(frag) &&
3632	off == skb_frag_off(frag) + skb_frag_size(frag);
3633	}
3634	return false;
3635	}
3636
3637	static inline int __skb_linearize(struct sk_buff *skb)
3638	{
3639	return __pskb_pull_tail(skb, skb->data_len) ? `0` : -ENOMEM;
3640	}
3641
3642	/**
3643	* skb_linearize - convert paged skb to linear one
3644	* @skb: buffer to linarize
3645	*
3646	* If there is no free memory -ENOMEM is returned, otherwise zero
3647	* is returned and the old skb data released.
3648	*/
3649	static inline int skb_linearize(struct sk_buff *skb)
3650	{
3651	return skb_is_nonlinear(skb) ? __skb_linearize(skb) : `0`;
3652	}
3653
3654	/**
3655	* skb_has_shared_frag - can any frag be overwritten
3656	* @skb: buffer to test
3657	*
3658	* Return true if the skb has at least one frag that might be modified
3659	* by an external entity (as in vmsplice()/sendfile())
3660	*/
3661	static inline bool skb_has_shared_frag(const struct sk_buff *skb)
3662	{
3663	return skb_is_nonlinear(skb) &&
3664	skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG;
3665	}
3666
3667	/**
3668	* skb_linearize_cow - make sure skb is linear and writable
3669	* @skb: buffer to process
3670	*
3671	* If there is no free memory -ENOMEM is returned, otherwise zero
3672	* is returned and the old skb data released.
3673	*/
3674	static inline int skb_linearize_cow(struct sk_buff *skb)
3675	{
3676	return skb_is_nonlinear(skb) \|\| skb_cloned(skb) ?
3677	__skb_linearize(skb) : `0`;
3678	}
3679
3680	static __always_inline void
3681	__skb_postpull_rcsum(struct sk_buff skb, const* void start, unsigned* int len,
3682	unsigned int off)
3683	{
3684	if (skb->ip_summed == CHECKSUM_COMPLETE)
3685	skb->csum = csum_block_sub(skb->csum,
3686	csum_partial(start, len, `0`), off);
3687	else if (skb->ip_summed == CHECKSUM_PARTIAL &&
3688	skb_checksum_start_offset(skb) < `0`)
3689	skb->ip_summed = CHECKSUM_NONE;
3690	}
3691
3692	/**
3693	* skb_postpull_rcsum - update checksum for received skb after pull
3694	* @skb: buffer to update
3695	* @start: start of data before pull
3696	* @len: length of data pulled
3697	*
3698	* After doing a pull on a received packet, you need to call this to
3699	* update the CHECKSUM_COMPLETE checksum, or set ip_summed to
3700	* CHECKSUM_NONE so that it can be recomputed from scratch.
3701	*/
3702	static inline void skb_postpull_rcsum(struct sk_buff *skb,
3703	const void start, unsigned* int len)
3704	{
3705	if (skb->ip_summed == CHECKSUM_COMPLETE)
3706	skb->csum = wsum_negate(csum_partial(start, len,
3707	wsum_negate(skb->csum)));
3708	else if (skb->ip_summed == CHECKSUM_PARTIAL &&
3709	skb_checksum_start_offset(skb) < `0`)
3710	skb->ip_summed = CHECKSUM_NONE;
3711	}
3712
3713	static __always_inline void
3714	__skb_postpush_rcsum(struct sk_buff skb, const* void start, unsigned* int len,
3715	unsigned int off)
3716	{
3717	if (skb->ip_summed == CHECKSUM_COMPLETE)
3718	skb->csum = csum_block_add(skb->csum,
3719	csum_partial(start, len, `0`), off);
3720	}
3721
3722	/**
3723	* skb_postpush_rcsum - update checksum for received skb after push
3724	* @skb: buffer to update
3725	* @start: start of data after push
3726	* @len: length of data pushed
3727	*
3728	* After doing a push on a received packet, you need to call this to
3729	* update the CHECKSUM_COMPLETE checksum.
3730	*/
3731	static inline void skb_postpush_rcsum(struct sk_buff *skb,
3732	const void start, unsigned* int len)
3733	{
3734	__skb_postpush_rcsum(skb, start, len, `0`);
3735	}
3736
3737	void skb_pull_rcsum(struct* sk_buff skb, unsigned* int len);
3738
3739	/**
3740	* skb_push_rcsum - push skb and update receive checksum
3741	* @skb: buffer to update
3742	* @len: length of data pulled
3743	*
3744	* This function performs an skb_push on the packet and updates
3745	* the CHECKSUM_COMPLETE checksum. It should be used on
3746	* receive path processing instead of skb_push unless you know
3747	* that the checksum difference is zero (e.g., a valid IP header)
3748	* or you are setting ip_summed to CHECKSUM_NONE.
3749	*/
3750	static inline void skb_push_rcsum(struct* sk_buff skb, unsigned* int len)
3751	{
3752	skb_push(skb, len);
3753	skb_postpush_rcsum(skb, skb->data, len);
3754	return skb->data;
3755	}
3756
3757	int pskb_trim_rcsum_slow(struct sk_buff skb, unsigned* int len);
3758	/**
3759	* pskb_trim_rcsum - trim received skb and update checksum
3760	* @skb: buffer to trim
3761	* @len: new length
3762	*
3763	* This is exactly the same as pskb_trim except that it ensures the
3764	* checksum of received packets are still valid after the operation.
3765	* It can change skb pointers.
3766	*/
3767
3768	static inline int pskb_trim_rcsum(struct sk_buff skb, unsigned* int len)
3769	{
3770	if (likely(len >= skb->len))
3771	return `0`;
3772	return pskb_trim_rcsum_slow(skb, len);
3773	}
3774
3775	static inline int __skb_trim_rcsum(struct sk_buff skb, unsigned* int len)
3776	{
3777	if (skb->ip_summed == CHECKSUM_COMPLETE)
3778	skb->ip_summed = CHECKSUM_NONE;
3779	__skb_trim(skb, len);
3780	return `0`;
3781	}
3782
3783	static inline int __skb_grow_rcsum(struct sk_buff skb, unsigned* int len)
3784	{
3785	if (skb->ip_summed == CHECKSUM_COMPLETE)
3786	skb->ip_summed = CHECKSUM_NONE;
3787	return __skb_grow(skb, len);
3788	}
3789
3790	#define rb_to_skb(rb) rb_entry_safe(rb, struct sk_buff, rbnode)
3791	#define skb_rb_first(root) rb_to_skb(rb_first(root))
3792	#define skb_rb_last(root) rb_to_skb(rb_last(root))
3793	#define skb_rb_next(skb) rb_to_skb(rb_next(&(skb)->rbnode))
3794	#define skb_rb_prev(skb) rb_to_skb(rb_prev(&(skb)->rbnode))
3795
3796	#define skb_queue_walk(queue, skb) \
3797	for (skb = (queue)->next; \
3798	skb != (struct sk_buff *)(queue); \
3799	skb = skb->next)
3800
3801	#define skb_queue_walk_safe(queue, skb, tmp) \
3802	for (skb = (queue)->next, tmp = skb->next; \
3803	skb != (struct sk_buff *)(queue); \
3804	skb = tmp, tmp = skb->next)
3805
3806	#define skb_queue_walk_from(queue, skb) \
3807	for (; skb != (struct sk_buff *)(queue); \
3808	skb = skb->next)
3809
3810	#define skb_rbtree_walk(skb, root) \
3811	for (skb = skb_rb_first(root); skb != NULL; \
3812	skb = skb_rb_next(skb))
3813
3814	#define skb_rbtree_walk_from(skb) \
3815	for (; skb != NULL; \
3816	skb = skb_rb_next(skb))
3817
3818	#define skb_rbtree_walk_from_safe(skb, tmp) \
3819	for (; tmp = skb ? skb_rb_next(skb) : NULL, (skb != NULL); \
3820	skb = tmp)
3821
3822	#define skb_queue_walk_from_safe(queue, skb, tmp) \
3823	for (tmp = skb->next; \
3824	skb != (struct sk_buff *)(queue); \
3825	skb = tmp, tmp = skb->next)
3826
3827	#define skb_queue_reverse_walk(queue, skb) \
3828	for (skb = (queue)->prev; \
3829	skb != (struct sk_buff *)(queue); \
3830	skb = skb->prev)
3831
3832	#define skb_queue_reverse_walk_safe(queue, skb, tmp) \
3833	for (skb = (queue)->prev, tmp = skb->prev; \
3834	skb != (struct sk_buff *)(queue); \
3835	skb = tmp, tmp = skb->prev)
3836
3837	#define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
3838	for (tmp = skb->prev; \
3839	skb != (struct sk_buff *)(queue); \
3840	skb = tmp, tmp = skb->prev)
3841
3842	static inline bool skb_has_frag_list(const struct sk_buff *skb)
3843	{
3844	return skb_shinfo(skb)->frag_list != NULL;
3845	}
3846
3847	static inline void skb_frag_list_init(struct sk_buff *skb)
3848	{
3849	skb_shinfo(skb)->frag_list = NULL;
3850	}
3851
3852	#define skb_walk_frags(skb, iter) \
3853	for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
3854
3855
3856	int __skb_wait_for_more_packets(struct sock sk, struct* sk_buff_head *queue,
3857	int err, long* *timeo_p,
3858	const struct sk_buff *skb);
3859	struct sk_buff __skb_try_recv_from_queue(struct* sock *sk,
3860	struct sk_buff_head *queue,
3861	unsigned int flags,
3862	int off, int* *err,
3863	struct sk_buff **last);
3864	struct sk_buff __skb_try_recv_datagram(struct* sock *sk,
3865	struct sk_buff_head *queue,
3866	unsigned int flags, int off, int* *err,
3867	struct sk_buff **last);
3868	struct sk_buff __skb_recv_datagram(struct* sock *sk,
3869	struct sk_buff_head *sk_queue,
3870	unsigned int flags, int off, int* *err);
3871	struct sk_buff skb_recv_datagram(struct* sock sk, unsigned* int flags, int *err);
3872	__poll_t datagram_poll(struct file file, struct* socket *sock,
3873	struct poll_table_struct *wait);
3874	int skb_copy_datagram_iter(const struct sk_buff from, int* offset,
3875	struct iov_iter to, int* size);
3876	static inline int skb_copy_datagram_msg(const struct sk_buff from, int* offset,
3877	struct msghdr msg, int* size)
3878	{
3879	return skb_copy_datagram_iter(from, offset, &msg->msg_iter, size);
3880	}
3881	int skb_copy_and_csum_datagram_msg(struct sk_buff skb, int* hlen,
3882	struct msghdr *msg);
3883	int skb_copy_and_hash_datagram_iter(const struct sk_buff skb, int* offset,
3884	struct iov_iter to, int* len,
3885	struct ahash_request *hash);
3886	int skb_copy_datagram_from_iter(struct sk_buff skb, int* offset,
3887	struct iov_iter from, int* len);
3888	int zerocopy_sg_from_iter(struct sk_buff skb, struct* iov_iter *frm);
3889	void skb_free_datagram(struct sock sk, struct* sk_buff *skb);
3890	void __skb_free_datagram_locked(struct sock sk, struct* sk_buff skb, int* len);
3891	static inline void skb_free_datagram_locked(struct sock *sk,
3892	struct sk_buff *skb)
3893	{
3894	__skb_free_datagram_locked(sk, skb, `0`);
3895	}
3896	int skb_kill_datagram(struct sock sk, struct* sk_buff skb, unsigned* int flags);
3897	int skb_copy_bits(const struct sk_buff skb, int* offset, void to, int* len);
3898	int skb_store_bits(struct sk_buff skb, int* offset, const void from, int* len);
3899	__wsum skb_copy_and_csum_bits(const struct sk_buff skb, int* offset, u8 *to,
3900	int len);
3901	int skb_splice_bits(struct sk_buff skb, struct* sock sk, unsigned* int offset,
3902	struct pipe_inode_info pipe, unsigned* int len,
3903	unsigned int flags);
3904	int skb_send_sock_locked(struct sock sk, struct* sk_buff skb, int* offset,
3905	int len);
3906	int skb_send_sock(struct sock sk, struct* sk_buff skb, int* offset, int len);
3907	void skb_copy_and_csum_dev(const struct sk_buff skb, u8 to);
3908	unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
3909	int skb_zerocopy(struct sk_buff to, struct* sk_buff *from,
3910	int len, int hlen);
3911	void skb_split(struct sk_buff skb, struct* sk_buff skb1, const* u32 len);
3912	int skb_shift(struct sk_buff tgt, struct* sk_buff skb, int* shiftlen);
3913	void skb_scrub_packet(struct sk_buff *skb, bool xnet);
3914	bool skb_gso_validate_network_len(const struct sk_buff skb, unsigned* int mtu);
3915	bool skb_gso_validate_mac_len(const struct sk_buff skb, unsigned* int len);
3916	struct sk_buff skb_segment(struct* sk_buff *skb, netdev_features_t features);
3917	struct sk_buff skb_segment_list(struct* sk_buff *skb, netdev_features_t features,
3918	unsigned int offset);
3919	struct sk_buff skb_vlan_untag(struct* sk_buff *skb);
3920	int skb_ensure_writable(struct sk_buff skb, unsigned* int write_len);
3921	int __skb_vlan_pop(struct sk_buff skb, u16 vlan_tci);
3922	int skb_vlan_pop(struct sk_buff *skb);
3923	int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);
3924	int skb_eth_pop(struct sk_buff *skb);
3925	int skb_eth_push(struct sk_buff skb, const* unsigned char *dst,
3926	const unsigned char *src);
3927	int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto,
3928	int mac_len, bool ethernet);
3929	int skb_mpls_pop(struct sk_buff skb, __be16 next_proto, int* mac_len,
3930	bool ethernet);
3931	int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse);
3932	int skb_mpls_dec_ttl(struct sk_buff *skb);
3933	struct sk_buff pskb_extract(struct* sk_buff skb, int* off, int to_copy,
3934	gfp_t gfp);
3935
3936	static inline int memcpy_from_msg(void data, struct* msghdr msg, int* len)
3937	{
3938	return copy_from_iter_full(data, len, &msg->msg_iter) ? `0` : -EFAULT;
3939	}
3940
3941	static inline int memcpy_to_msg(struct msghdr msg, void* data, int* len)
3942	{
3943	return copy_to_iter(data, len, &msg->msg_iter) == len ? `0` : -EFAULT;
3944	}
3945
3946	struct skb_checksum_ops {
3947	__wsum (update)(const* void mem, int* len, __wsum wsum);
3948	__wsum (combine)(__wsum csum, __wsum csum2, int* offset, int len);
3949	};
3950
3951	extern const struct skb_checksum_ops *crc32c_csum_stub __read_mostly;
3952
3953	__wsum __skb_checksum(const struct sk_buff skb, int* offset, int len,
3954	__wsum csum, const struct skb_checksum_ops *ops);
3955	__wsum skb_checksum(const struct sk_buff skb, int* offset, int len,
3956	__wsum csum);
3957
3958	static inline void * __must_check
3959	__skb_header_pointer(const struct sk_buff skb, int* offset, int len,
3960	const void data, int* hlen, void *buffer)
3961	{
3962	if (likely(hlen - offset >= len))
3963	return (void *)data + offset;
3964
3965	if (!skb \|\| unlikely(skb_copy_bits(skb, offset, buffer, len) < `0`))
3966	return NULL;
3967
3968	return buffer;
3969	}
3970
3971	static inline void * __must_check
3972	skb_header_pointer(const struct sk_buff skb, int* offset, int len, void *buffer)
3973	{
3974	return __skb_header_pointer(skb, offset, len, skb->data,
3975	skb_headlen(skb), buffer);
3976	}
3977
3978	/**
3979	* skb_needs_linearize - check if we need to linearize a given skb
3980	* depending on the given device features.
3981	* @skb: socket buffer to check
3982	* @features: net device features
3983	*
3984	* Returns true if either:
3985	* 1. skb has frag_list and the device doesn't support FRAGLIST, or
3986	* 2. skb is fragmented and the device does not support SG.
3987	*/
3988	static inline bool skb_needs_linearize(struct sk_buff *skb,
3989	netdev_features_t features)
3990	{
3991	return skb_is_nonlinear(skb) &&
3992	((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) \|\|
3993	(skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG)));
3994	}
3995
3996	static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
3997	void *to,
3998	const unsigned int len)
3999	{
4000	memcpy(to, skb->data, len);
4001	}
4002
4003	static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
4004	const int offset, void *to,
4005	const unsigned int len)
4006	{
4007	memcpy(to, skb->data + offset, len);
4008	}
4009
4010	static inline void skb_copy_to_linear_data(struct sk_buff *skb,
4011	const void *from,
4012	const unsigned int len)
4013	{
4014	memcpy(skb->data, from, len);
4015	}
4016
4017	static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
4018	const int offset,
4019	const void *from,
4020	const unsigned int len)
4021	{
4022	memcpy(skb->data + offset, from, len);
4023	}
4024
4025	void skb_init(void);
4026
4027	static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
4028	{
4029	return skb->tstamp;
4030	}
4031
4032	/**
4033	* skb_get_timestamp - get timestamp from a skb
4034	* @skb: skb to get stamp from
4035	* @stamp: pointer to struct __kernel_old_timeval to store stamp in
4036	*
4037	* Timestamps are stored in the skb as offsets to a base timestamp.
4038	* This function converts the offset back to a struct timeval and stores
4039	* it in stamp.
4040	*/
4041	static inline void skb_get_timestamp(const struct sk_buff *skb,
4042	struct __kernel_old_timeval *stamp)
4043	{
4044	*stamp = ns_to_kernel_old_timeval(skb->tstamp);
4045	}
4046
4047	static inline void skb_get_new_timestamp(const struct sk_buff *skb,
4048	struct __kernel_sock_timeval *stamp)
4049	{
4050	struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4051
4052	stamp->tv_sec = ts.tv_sec;
4053	stamp->tv_usec = ts.tv_nsec / `1000`;
4054	}
4055
4056	static inline void skb_get_timestampns(const struct sk_buff *skb,
4057	struct __kernel_old_timespec *stamp)
4058	{
4059	struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4060
4061	stamp->tv_sec = ts.tv_sec;
4062	stamp->tv_nsec = ts.tv_nsec;
4063	}
4064
4065	static inline void skb_get_new_timestampns(const struct sk_buff *skb,
4066	struct __kernel_timespec *stamp)
4067	{
4068	struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4069
4070	stamp->tv_sec = ts.tv_sec;
4071	stamp->tv_nsec = ts.tv_nsec;
4072	}
4073
4074	static inline void __net_timestamp(struct sk_buff *skb)
4075	{
4076	skb->tstamp = ktime_get_real();
4077	skb->mono_delivery_time = `0`;
4078	}
4079
4080	static inline ktime_t net_timedelta(ktime_t t)
4081	{
4082	return ktime_sub(ktime_get_real(), t);
4083	}
4084
4085	static inline void skb_set_delivery_time(struct sk_buff *skb, ktime_t kt,
4086	bool mono)
4087	{
4088	skb->tstamp = kt;
4089	skb->mono_delivery_time = kt && mono;
4090	}
4091
4092	DECLARE_STATIC_KEY_FALSE(netstamp_needed_key);
4093
4094	/ It is used in the ingress path to clear the delivery_time.*
4095	* If needed, set the skb->tstamp to the (rcv) timestamp.
4096	*/
4097	static inline void skb_clear_delivery_time(struct sk_buff *skb)
4098	{
4099	if (skb->mono_delivery_time) {
4100	skb->mono_delivery_time = `0`;
4101	if (static_branch_unlikely(&netstamp_needed_key))
4102	skb->tstamp = ktime_get_real();
4103	else
4104	skb->tstamp = `0`;
4105	}
4106	}
4107
4108	static inline void skb_clear_tstamp(struct sk_buff *skb)
4109	{
4110	if (skb->mono_delivery_time)
4111	return;
4112
4113	skb->tstamp = `0`;
4114	}
4115
4116	static inline ktime_t skb_tstamp(const struct sk_buff *skb)
4117	{
4118	if (skb->mono_delivery_time)
4119	return `0`;
4120
4121	return skb->tstamp;
4122	}
4123
4124	static inline ktime_t skb_tstamp_cond(const struct sk_buff *skb, bool cond)
4125	{
4126	if (!skb->mono_delivery_time && skb->tstamp)
4127	return skb->tstamp;
4128
4129	if (static_branch_unlikely(&netstamp_needed_key) \|\| cond)
4130	return ktime_get_real();
4131
4132	return `0`;
4133	}
4134
4135	static inline u8 skb_metadata_len(const struct sk_buff *skb)
4136	{
4137	return skb_shinfo(skb)->meta_len;
4138	}
4139
4140	static inline void skb_metadata_end(const* struct sk_buff *skb)
4141	{
4142	return skb_mac_header(skb);
4143	}
4144
4145	static inline bool __skb_metadata_differs(const struct sk_buff *skb_a,
4146	const struct sk_buff *skb_b,
4147	u8 meta_len)
4148	{
4149	const void *a = skb_metadata_end(skb_a);
4150	const void *b = skb_metadata_end(skb_b);
4151	/ Using more efficient varaiant than plain call to memcmp(). /
4152	#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
4153	u64 diffs = `0`;
4154
4155	switch (meta_len) {
4156	#define __it(x, op) (x -= sizeof(u##op))
4157	#define __it_diff(a, b, op) ((u##op )__it(a, op)) ^ ((u##op )__it(b, op))
4158	case `32`: diffs \|= __it_diff(a, b, `64`);
4159	fallthrough;
4160	case `24`: diffs \|= __it_diff(a, b, `64`);
4161	fallthrough;
4162	case `16`: diffs \|= __it_diff(a, b, `64`);
4163	fallthrough;
4164	case `8`: diffs \|= __it_diff(a, b, `64`);
4165	break;
4166	case `28`: diffs \|= __it_diff(a, b, `64`);
4167	fallthrough;
4168	case `20`: diffs \|= __it_diff(a, b, `64`);
4169	fallthrough;
4170	case `12`: diffs \|= __it_diff(a, b, `64`);
4171	fallthrough;
4172	case `4`: diffs \|= __it_diff(a, b, `32`);
4173	break;
4174	}
4175	return diffs;
4176	#else
4177	return memcmp(a - meta_len, b - meta_len, meta_len);
4178	#endif
4179	}
4180
4181	static inline bool skb_metadata_differs(const struct sk_buff *skb_a,
4182	const struct sk_buff *skb_b)
4183	{
4184	u8 len_a = skb_metadata_len(skb_a);
4185	u8 len_b = skb_metadata_len(skb_b);
4186
4187	if (!(len_a \| len_b))
4188	return false;
4189
4190	return len_a != len_b ?
4191	true : __skb_metadata_differs(skb_a, skb_b, len_a);
4192	}
4193
4194	static inline void skb_metadata_set(struct sk_buff *skb, u8 meta_len)
4195	{
4196	skb_shinfo(skb)->meta_len = meta_len;
4197	}
4198
4199	static inline void skb_metadata_clear(struct sk_buff *skb)
4200	{
4201	skb_metadata_set(skb, `0`);
4202	}
4203
4204	struct sk_buff skb_clone_sk(struct* sk_buff *skb);
4205
4206	#ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
4207
4208	void skb_clone_tx_timestamp(struct sk_buff *skb);
4209	bool skb_defer_rx_timestamp(struct sk_buff *skb);
4210
4211	#else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
4212
4213	static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
4214	{
4215	}
4216
4217	static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
4218	{
4219	return false;
4220	}
4221
4222	#endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
4223
4224	/**
4225	* skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
4226	*
4227	* PHY drivers may accept clones of transmitted packets for
4228	* timestamping via their phy_driver.txtstamp method. These drivers
4229	* must call this function to return the skb back to the stack with a
4230	* timestamp.
4231	*
4232	* @skb: clone of the original outgoing packet
4233	* @hwtstamps: hardware time stamps
4234	*
4235	*/
4236	void skb_complete_tx_timestamp(struct sk_buff *skb,
4237	struct skb_shared_hwtstamps *hwtstamps);
4238
4239	void __skb_tstamp_tx(struct sk_buff orig_skb, const* struct sk_buff *ack_skb,
4240	struct skb_shared_hwtstamps *hwtstamps,
4241	struct sock sk, int* tstype);
4242
4243	/**
4244	* skb_tstamp_tx - queue clone of skb with send time stamps
4245	* @orig_skb: the original outgoing packet
4246	* @hwtstamps: hardware time stamps, may be NULL if not available
4247	*
4248	* If the skb has a socket associated, then this function clones the
4249	* skb (thus sharing the actual data and optional structures), stores
4250	* the optional hardware time stamping information (if non NULL) or
4251	* generates a software time stamp (otherwise), then queues the clone
4252	* to the error queue of the socket. Errors are silently ignored.
4253	*/
4254	void skb_tstamp_tx(struct sk_buff *orig_skb,
4255	struct skb_shared_hwtstamps *hwtstamps);
4256
4257	/**
4258	* skb_tx_timestamp() - Driver hook for transmit timestamping
4259	*
4260	* Ethernet MAC Drivers should call this function in their hard_xmit()
4261	* function immediately before giving the sk_buff to the MAC hardware.
4262	*
4263	* Specifically, one should make absolutely sure that this function is
4264	* called before TX completion of this packet can trigger. Otherwise
4265	* the packet could potentially already be freed.
4266	*
4267	* @skb: A socket buffer.
4268	*/
4269	static inline void skb_tx_timestamp(struct sk_buff *skb)
4270	{
4271	skb_clone_tx_timestamp(skb);
4272	if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP)
4273	skb_tstamp_tx(skb, NULL);
4274	}
4275
4276	/**
4277	* skb_complete_wifi_ack - deliver skb with wifi status
4278	*
4279	* @skb: the original outgoing packet
4280	* @acked: ack status
4281	*
4282	*/
4283	void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
4284
4285	__sum16 __skb_checksum_complete_head(struct sk_buff skb, int* len);
4286	__sum16 __skb_checksum_complete(struct sk_buff *skb);
4287
4288	static inline int skb_csum_unnecessary(const struct sk_buff *skb)
4289	{
4290	return ((skb->ip_summed == CHECKSUM_UNNECESSARY) \|\|
4291	skb->csum_valid \|\|
4292	(skb->ip_summed == CHECKSUM_PARTIAL &&
4293	skb_checksum_start_offset(skb) >= `0`));
4294	}
4295
4296	/**
4297	* skb_checksum_complete - Calculate checksum of an entire packet
4298	* @skb: packet to process
4299	*
4300	* This function calculates the checksum over the entire packet plus
4301	* the value of skb->csum. The latter can be used to supply the
4302	* checksum of a pseudo header as used by TCP/UDP. It returns the
4303	* checksum.
4304	*
4305	* For protocols that contain complete checksums such as ICMP/TCP/UDP,
4306	* this function can be used to verify that checksum on received
4307	* packets. In that case the function should return zero if the
4308	* checksum is correct. In particular, this function will return zero
4309	* if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
4310	* hardware has already verified the correctness of the checksum.
4311	*/
4312	static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
4313	{
4314	return skb_csum_unnecessary(skb) ?
4315	`0` : __skb_checksum_complete(skb);
4316	}
4317
4318	static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb)
4319	{
4320	if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4321	if (skb->csum_level == `0`)
4322	skb->ip_summed = CHECKSUM_NONE;
4323	else
4324	skb->csum_level--;
4325	}
4326	}
4327
4328	static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb)
4329	{
4330	if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4331	if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
4332	skb->csum_level++;
4333	} else if (skb->ip_summed == CHECKSUM_NONE) {
4334	skb->ip_summed = CHECKSUM_UNNECESSARY;
4335	skb->csum_level = `0`;
4336	}
4337	}
4338
4339	static inline void __skb_reset_checksum_unnecessary(struct sk_buff *skb)
4340	{
4341	if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4342	skb->ip_summed = CHECKSUM_NONE;
4343	skb->csum_level = `0`;
4344	}
4345	}
4346
4347	/ Check if we need to perform checksum complete validation.*
4348	*
4349	* Returns true if checksum complete is needed, false otherwise
4350	* (either checksum is unnecessary or zero checksum is allowed).
4351	*/
4352	static inline bool __skb_checksum_validate_needed(struct sk_buff *skb,
4353	bool zero_okay,
4354	__sum16 check)
4355	{
4356	if (skb_csum_unnecessary(skb) \|\| (zero_okay && !check)) {
4357	skb->csum_valid = `1`;
4358	__skb_decr_checksum_unnecessary(skb);
4359	return false;
4360	}
4361
4362	return true;
4363	}
4364
4365	/ For small packets <= CHECKSUM_BREAK perform checksum complete directly*
4366	* in checksum_init.
4367	*/
4368	#define CHECKSUM_BREAK 76
4369
4370	/ Unset checksum-complete*
4371	*
4372	* Unset checksum complete can be done when packet is being modified
4373	* (uncompressed for instance) and checksum-complete value is
4374	* invalidated.
4375	*/
4376	static inline void skb_checksum_complete_unset(struct sk_buff *skb)
4377	{
4378	if (skb->ip_summed == CHECKSUM_COMPLETE)
4379	skb->ip_summed = CHECKSUM_NONE;
4380	}
4381
4382	/ Validate (init) checksum based on checksum complete.*
4383	*
4384	* Return values:
4385	* 0: checksum is validated or try to in skb_checksum_complete. In the latter
4386	* case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
4387	* checksum is stored in skb->csum for use in __skb_checksum_complete
4388	* non-zero: value of invalid checksum
4389	*
4390	*/
4391	static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb,
4392	bool complete,
4393	__wsum psum)
4394	{
4395	if (skb->ip_summed == CHECKSUM_COMPLETE) {
4396	if (!csum_fold(csum_add(psum, skb->csum))) {
4397	skb->csum_valid = `1`;
4398	return `0`;
4399	}
4400	}
4401
4402	skb->csum = psum;
4403
4404	if (complete \|\| skb->len <= CHECKSUM_BREAK) {
4405	__sum16 csum;
4406
4407	csum = __skb_checksum_complete(skb);
4408	skb->csum_valid = !csum;
4409	return csum;
4410	}
4411
4412	return `0`;
4413	}
4414
4415	static inline __wsum null_compute_pseudo(struct sk_buff skb, int* proto)
4416	{
4417	return `0`;
4418	}
4419
4420	/ Perform checksum validate (init). Note that this is a macro since we only*
4421	* want to calculate the pseudo header which is an input function if necessary.
4422	* First we try to validate without any computation (checksum unnecessary) and
4423	* then calculate based on checksum complete calling the function to compute
4424	* pseudo header.
4425	*
4426	* Return values:
4427	* 0: checksum is validated or try to in skb_checksum_complete
4428	* non-zero: value of invalid checksum
4429	*/
4430	#define __skb_checksum_validate(skb, proto, complete, \
4431	zero_okay, check, compute_pseudo) \
4432	({ \
4433	__sum16 __ret = 0; \
4434	skb->csum_valid = 0; \
4435	if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
4436	__ret = __skb_checksum_validate_complete(skb, \
4437	complete, compute_pseudo(skb, proto)); \
4438	__ret; \
4439	})
4440
4441	#define skb_checksum_init(skb, proto, compute_pseudo) \
4442	__skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
4443
4444	#define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
4445	__skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
4446
4447	#define skb_checksum_validate(skb, proto, compute_pseudo) \
4448	__skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
4449
4450	#define skb_checksum_validate_zero_check(skb, proto, check, \
4451	compute_pseudo) \
4452	__skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
4453
4454	#define skb_checksum_simple_validate(skb) \
4455	__skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
4456
4457	static inline bool __skb_checksum_convert_check(struct sk_buff *skb)
4458	{
4459	return (skb->ip_summed == CHECKSUM_NONE && skb->csum_valid);
4460	}
4461
4462	static inline void __skb_checksum_convert(struct sk_buff *skb, __wsum pseudo)
4463	{
4464	skb->csum = ~pseudo;
4465	skb->ip_summed = CHECKSUM_COMPLETE;
4466	}
4467
4468	#define skb_checksum_try_convert(skb, proto, compute_pseudo) \
4469	do { \
4470	if (__skb_checksum_convert_check(skb)) \
4471	__skb_checksum_convert(skb, compute_pseudo(skb, proto)); \
4472	} while (0)
4473
4474	static inline void skb_remcsum_adjust_partial(struct sk_buff skb, void* *ptr,
4475	u16 start, u16 offset)
4476	{
4477	skb->ip_summed = CHECKSUM_PARTIAL;
4478	skb->csum_start = ((unsigned char *)ptr + start) - skb->head;
4479	skb->csum_offset = offset - start;
4480	}
4481
4482	/ Update skbuf and packet to reflect the remote checksum offload operation.*
4483	* When called, ptr indicates the starting point for skb->csum when
4484	* ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
4485	* here, skb_postpull_rcsum is done so skb->csum start is ptr.
4486	*/
4487	static inline void skb_remcsum_process(struct sk_buff skb, void* *ptr,
4488	int start, int offset, bool nopartial)
4489	{
4490	__wsum delta;
4491
4492	if (!nopartial) {
4493	skb_remcsum_adjust_partial(skb, ptr, start, offset);
4494	return;
4495	}
4496
4497	if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) {
4498	__skb_checksum_complete(skb);
4499	skb_postpull_rcsum(skb, skb->data, ptr - (void *)skb->data);
4500	}
4501
4502	delta = remcsum_adjust(ptr, skb->csum, start, offset);
4503
4504	/ Adjust skb->csum since we changed the packet /
4505	skb->csum = csum_add(skb->csum, delta);
4506	}
4507
4508	static inline struct nf_conntrack skb_nfct(const* struct sk_buff *skb)
4509	{
4510	#if IS_ENABLED(CONFIG_NF_CONNTRACK)
4511	return (void *)(skb->_nfct & NFCT_PTRMASK);
4512	#else
4513	return NULL;
4514	#endif
4515	}
4516
4517	static inline unsigned long skb_get_nfct(const struct sk_buff *skb)
4518	{
4519	#if IS_ENABLED(CONFIG_NF_CONNTRACK)
4520	return skb->_nfct;
4521	#else
4522	return `0UL`;
4523	#endif
4524	}
4525
4526	static inline void skb_set_nfct(struct sk_buff skb, unsigned* long nfct)
4527	{
4528	#if IS_ENABLED(CONFIG_NF_CONNTRACK)
4529	skb->slow_gro \|= !!nfct;
4530	skb->_nfct = nfct;
4531	#endif
4532	}
4533
4534	#ifdef CONFIG_SKB_EXTENSIONS
4535	enum skb_ext_id {
4536	#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
4537	SKB_EXT_BRIDGE_NF,
4538	#endif
4539	#ifdef CONFIG_XFRM
4540	SKB_EXT_SEC_PATH,
4541	#endif
4542	#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
4543	TC_SKB_EXT,
4544	#endif
4545	#if IS_ENABLED(CONFIG_MPTCP)
4546	SKB_EXT_MPTCP,
4547	#endif
4548	#if IS_ENABLED(CONFIG_MCTP_FLOWS)
4549	SKB_EXT_MCTP,
4550	#endif
4551	SKB_EXT_NUM, / must be last /
4552	};
4553
4554	/**
4555	* struct skb_ext - sk_buff extensions
4556	* @refcnt: 1 on allocation, deallocated on 0
4557	* @offset: offset to add to @data to obtain extension address
4558	* @chunks: size currently allocated, stored in SKB_EXT_ALIGN_SHIFT units
4559	* @data: start of extension data, variable sized
4560	*
4561	* Note: offsets/lengths are stored in chunks of 8 bytes, this allows
4562	* to use 'u8' types while allowing up to 2kb worth of extension data.
4563	*/
4564	struct skb_ext {
4565	refcount_t refcnt;
4566	u8 offset[SKB_EXT_NUM]; / in chunks of 8 bytes /
4567	u8 chunks; / same /
4568	char data[] __aligned(`8`);
4569	};
4570
4571	struct skb_ext *__skb_ext_alloc(gfp_t flags);
4572	void __skb_ext_set(struct* sk_buff skb, enum* skb_ext_id id,
4573	struct skb_ext *ext);
4574	void skb_ext_add(struct* sk_buff skb, enum* skb_ext_id id);
4575	void __skb_ext_del(struct sk_buff skb, enum* skb_ext_id id);
4576	void __skb_ext_put(struct skb_ext *ext);
4577
4578	static inline void skb_ext_put(struct sk_buff *skb)
4579	{
4580	if (skb->active_extensions)
4581	__skb_ext_put(skb->extensions);
4582	}
4583
4584	static inline void __skb_ext_copy(struct sk_buff *dst,
4585	const struct sk_buff *src)
4586	{
4587	dst->active_extensions = src->active_extensions;
4588
4589	if (src->active_extensions) {
4590	struct skb_ext *ext = src->extensions;
4591
4592	refcount_inc(&ext->refcnt);
4593	dst->extensions = ext;
4594	}
4595	}
4596
4597	static inline void skb_ext_copy(struct sk_buff dst, const* struct sk_buff *src)
4598	{
4599	skb_ext_put(dst);
4600	__skb_ext_copy(dst, src);
4601	}
4602
4603	static inline bool __skb_ext_exist(const struct skb_ext ext, enum* skb_ext_id i)
4604	{
4605	return !!ext->offset[i];
4606	}
4607
4608	static inline bool skb_ext_exist(const struct sk_buff skb, enum* skb_ext_id id)
4609	{
4610	return skb->active_extensions & (`1` << id);
4611	}
4612
4613	static inline void skb_ext_del(struct sk_buff skb, enum* skb_ext_id id)
4614	{
4615	if (skb_ext_exist(skb, id))
4616	__skb_ext_del(skb, id);
4617	}
4618
4619	static inline void skb_ext_find(const* struct sk_buff skb, enum* skb_ext_id id)
4620	{
4621	if (skb_ext_exist(skb, id)) {
4622	struct skb_ext *ext = skb->extensions;
4623
4624	return (void *)ext + (ext->offset[id] << `3`);
4625	}
4626
4627	return NULL;
4628	}
4629
4630	static inline void skb_ext_reset(struct sk_buff *skb)
4631	{
4632	if (unlikely(skb->active_extensions)) {
4633	__skb_ext_put(skb->extensions);
4634	skb->active_extensions = `0`;
4635	}
4636	}
4637
4638	static inline bool skb_has_extensions(struct sk_buff *skb)
4639	{
4640	return unlikely(skb->active_extensions);
4641	}
4642	#else
4643	static inline void skb_ext_put(struct sk_buff *skb) {}
4644	static inline void skb_ext_reset(struct sk_buff *skb) {}
4645	static inline void skb_ext_del(struct sk_buff skb, int* unused) {}
4646	static inline void __skb_ext_copy(struct sk_buff d, const* struct sk_buff *s) {}
4647	static inline void skb_ext_copy(struct sk_buff dst, const* struct sk_buff *s) {}
4648	static inline bool skb_has_extensions(struct sk_buff skb) { return* false; }
4649	#endif /* CONFIG_SKB_EXTENSIONS */
4650
4651	static inline void nf_reset_ct(struct sk_buff *skb)
4652	{
4653	#if defined(CONFIG_NF_CONNTRACK) \|\| defined(CONFIG_NF_CONNTRACK_MODULE)
4654	nf_conntrack_put(skb_nfct(skb));
4655	skb->_nfct = `0`;
4656	#endif
4657	}
4658
4659	static inline void nf_reset_trace(struct sk_buff *skb)
4660	{
4661	#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) \|\| defined(CONFIG_NF_TABLES)
4662	skb->nf_trace = `0`;
4663	#endif
4664	}
4665
4666	static inline void ipvs_reset(struct sk_buff *skb)
4667	{
4668	#if IS_ENABLED(CONFIG_IP_VS)
4669	skb->ipvs_property = `0`;
4670	#endif
4671	}
4672
4673	/ Note: This doesn't put any conntrack info in dst. /
4674	static inline void __nf_copy(struct sk_buff dst, const* struct sk_buff *src,
4675	bool copy)
4676	{
4677	#if defined(CONFIG_NF_CONNTRACK) \|\| defined(CONFIG_NF_CONNTRACK_MODULE)
4678	dst->_nfct = src->_nfct;
4679	nf_conntrack_get(skb_nfct(src));
4680	#endif
4681	#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) \|\| defined(CONFIG_NF_TABLES)
4682	if (copy)
4683	dst->nf_trace = src->nf_trace;
4684	#endif
4685	}
4686
4687	static inline void nf_copy(struct sk_buff dst, const* struct sk_buff *src)
4688	{
4689	#if defined(CONFIG_NF_CONNTRACK) \|\| defined(CONFIG_NF_CONNTRACK_MODULE)
4690	nf_conntrack_put(skb_nfct(dst));
4691	#endif
4692	dst->slow_gro = src->slow_gro;
4693	__nf_copy(dst, src, true);
4694	}
4695
4696	#ifdef CONFIG_NETWORK_SECMARK
4697	static inline void skb_copy_secmark(struct sk_buff to, const* struct sk_buff *from)
4698	{
4699	to->secmark = from->secmark;
4700	}
4701
4702	static inline void skb_init_secmark(struct sk_buff *skb)
4703	{
4704	skb->secmark = `0`;
4705	}
4706	#else
4707	static inline void skb_copy_secmark(struct sk_buff to, const* struct sk_buff *from)
4708	{ }
4709
4710	static inline void skb_init_secmark(struct sk_buff *skb)
4711	{ }
4712	#endif
4713
4714	static inline int secpath_exists(const struct sk_buff *skb)
4715	{
4716	#ifdef CONFIG_XFRM
4717	return skb_ext_exist(skb, SKB_EXT_SEC_PATH);
4718	#else
4719	return `0`;
4720	#endif
4721	}
4722
4723	static inline bool skb_irq_freeable(const struct sk_buff *skb)
4724	{
4725	return !skb->destructor &&
4726	!secpath_exists(skb) &&
4727	!skb_nfct(skb) &&
4728	!skb->_skb_refdst &&
4729	!skb_has_frag_list(skb);
4730	}
4731
4732	static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
4733	{
4734	skb->queue_mapping = queue_mapping;
4735	}
4736
4737	static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
4738	{
4739	return skb->queue_mapping;
4740	}
4741
4742	static inline void skb_copy_queue_mapping(struct sk_buff to, const* struct sk_buff *from)
4743	{
4744	to->queue_mapping = from->queue_mapping;
4745	}
4746
4747	static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
4748	{
4749	skb->queue_mapping = rx_queue + `1`;
4750	}
4751
4752	static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
4753	{
4754	return skb->queue_mapping - `1`;
4755	}
4756
4757	static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
4758	{
4759	return skb->queue_mapping != `0`;
4760	}
4761
4762	static inline void skb_set_dst_pending_confirm(struct sk_buff *skb, u32 val)
4763	{
4764	skb->dst_pending_confirm = val;
4765	}
4766
4767	static inline bool skb_get_dst_pending_confirm(const struct sk_buff *skb)
4768	{
4769	return skb->dst_pending_confirm != `0`;
4770	}
4771
4772	static inline struct sec_path skb_sec_path(const* struct sk_buff *skb)
4773	{
4774	#ifdef CONFIG_XFRM
4775	return skb_ext_find(skb, SKB_EXT_SEC_PATH);
4776	#else
4777	return NULL;
4778	#endif
4779	}
4780
4781	/ Keeps track of mac header offset relative to skb->head.*
4782	* It is useful for TSO of Tunneling protocol. e.g. GRE.
4783	* For non-tunnel skb it points to skb_mac_header() and for
4784	* tunnel skb it points to outer mac header.
4785	* Keeps track of level of encapsulation of network headers.
4786	*/
4787	struct skb_gso_cb {
4788	union {
4789	int mac_offset;
4790	int data_offset;
4791	};
4792	int encap_level;
4793	__wsum csum;
4794	__u16 csum_start;
4795	};
4796	#define SKB_GSO_CB_OFFSET 32
4797	#define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_GSO_CB_OFFSET))
4798
4799	static inline int skb_tnl_header_len(const struct sk_buff *inner_skb)
4800	{
4801	return (skb_mac_header(inner_skb) - inner_skb->head) -
4802	SKB_GSO_CB(inner_skb)->mac_offset;
4803	}
4804
4805	static inline int gso_pskb_expand_head(struct sk_buff skb, int* extra)
4806	{
4807	int new_headroom, headroom;
4808	int ret;
4809
4810	headroom = skb_headroom(skb);
4811	ret = pskb_expand_head(skb, extra, `0`, GFP_ATOMIC);
4812	if (ret)
4813	return ret;
4814
4815	new_headroom = skb_headroom(skb);
4816	SKB_GSO_CB(skb)->mac_offset += (new_headroom - headroom);
4817	return `0`;
4818	}
4819
4820	static inline void gso_reset_checksum(struct sk_buff *skb, __wsum res)
4821	{
4822	/ Do not update partial checksums if remote checksum is enabled. /
4823	if (skb->remcsum_offload)
4824	return;
4825
4826