1/* SPDX-License-Identifier: GPL-2.0-or-later */
2
3#ifndef _NET_IPV6_GRO_H
4#define _NET_IPV6_GRO_H
5
6#include <linux/indirect_call_wrapper.h>
7#include <linux/ip.h>
8#include <linux/ipv6.h>
9#include <net/ip6_checksum.h>
10#include <linux/skbuff.h>
11#include <net/udp.h>
12
13struct napi_gro_cb {
14 union {
15 struct {
16 /* Virtual address of skb_shinfo(skb)->frags[0].page + offset. */
17 void *frag0;
18
19 /* Length of frag0. */
20 unsigned int frag0_len;
21 };
22
23 struct {
24 /* used in skb_gro_receive() slow path */
25 struct sk_buff *last;
26
27 /* jiffies when first packet was created/queued */
28 unsigned long age;
29 };
30 };
31
32 /* This indicates where we are processing relative to skb->data. */
33 int data_offset;
34
35 /* This is non-zero if the packet cannot be merged with the new skb. */
36 u16 flush;
37
38 /* Save the IP ID here and check when we get to the transport layer */
39 u16 flush_id;
40
41 /* Number of segments aggregated. */
42 u16 count;
43
44 /* Used in ipv6_gro_receive() and foo-over-udp and esp-in-udp */
45 u16 proto;
46
47/* Used in napi_gro_cb::free */
48#define NAPI_GRO_FREE 1
49#define NAPI_GRO_FREE_STOLEN_HEAD 2
50 /* portion of the cb set to zero at every gro iteration */
51 struct_group(zeroed,
52
53 /* Start offset for remote checksum offload */
54 u16 gro_remcsum_start;
55
56 /* This is non-zero if the packet may be of the same flow. */
57 u8 same_flow:1;
58
59 /* Used in tunnel GRO receive */
60 u8 encap_mark:1;
61
62 /* GRO checksum is valid */
63 u8 csum_valid:1;
64
65 /* Number of checksums via CHECKSUM_UNNECESSARY */
66 u8 csum_cnt:3;
67
68 /* Free the skb? */
69 u8 free:2;
70
71 /* Used in foo-over-udp, set in udp[46]_gro_receive */
72 u8 is_ipv6:1;
73
74 /* Used in GRE, set in fou/gue_gro_receive */
75 u8 is_fou:1;
76
77 /* Used to determine if flush_id can be ignored */
78 u8 is_atomic:1;
79
80 /* Number of gro_receive callbacks this packet already went through */
81 u8 recursion_counter:4;
82
83 /* GRO is done by frag_list pointer chaining. */
84 u8 is_flist:1;
85 );
86
87 /* used to support CHECKSUM_COMPLETE for tunneling protocols */
88 __wsum csum;
89};
90
91#define NAPI_GRO_CB(skb) ((struct napi_gro_cb *)(skb)->cb)
92
93#define GRO_RECURSION_LIMIT 15
94static inline int gro_recursion_inc_test(struct sk_buff *skb)
95{
96 return ++NAPI_GRO_CB(skb)->recursion_counter == GRO_RECURSION_LIMIT;
97}
98
99typedef struct sk_buff *(*gro_receive_t)(struct list_head *, struct sk_buff *);
100static inline struct sk_buff *call_gro_receive(gro_receive_t cb,
101 struct list_head *head,
102 struct sk_buff *skb)
103{
104 if (unlikely(gro_recursion_inc_test(skb))) {
105 NAPI_GRO_CB(skb)->flush |= 1;
106 return NULL;
107 }
108
109 return cb(head, skb);
110}
111
112typedef struct sk_buff *(*gro_receive_sk_t)(struct sock *, struct list_head *,
113 struct sk_buff *);
114static inline struct sk_buff *call_gro_receive_sk(gro_receive_sk_t cb,
115 struct sock *sk,
116 struct list_head *head,
117 struct sk_buff *skb)
118{
119 if (unlikely(gro_recursion_inc_test(skb))) {
120 NAPI_GRO_CB(skb)->flush |= 1;
121 return NULL;
122 }
123
124 return cb(sk, head, skb);
125}
126
127static inline unsigned int skb_gro_offset(const struct sk_buff *skb)
128{
129 return NAPI_GRO_CB(skb)->data_offset;
130}
131
132static inline unsigned int skb_gro_len(const struct sk_buff *skb)
133{
134 return skb->len - NAPI_GRO_CB(skb)->data_offset;
135}
136
137static inline void skb_gro_pull(struct sk_buff *skb, unsigned int len)
138{
139 NAPI_GRO_CB(skb)->data_offset += len;
140}
141
142static inline void *skb_gro_header_fast(struct sk_buff *skb,
143 unsigned int offset)
144{
145 return NAPI_GRO_CB(skb)->frag0 + offset;
146}
147
148static inline int skb_gro_header_hard(struct sk_buff *skb, unsigned int hlen)
149{
150 return NAPI_GRO_CB(skb)->frag0_len < hlen;
151}
152
153static inline void skb_gro_frag0_invalidate(struct sk_buff *skb)
154{
155 NAPI_GRO_CB(skb)->frag0 = NULL;
156 NAPI_GRO_CB(skb)->frag0_len = 0;
157}
158
159static inline void *skb_gro_header_slow(struct sk_buff *skb, unsigned int hlen,
160 unsigned int offset)
161{
162 if (!pskb_may_pull(skb, len: hlen))
163 return NULL;
164
165 skb_gro_frag0_invalidate(skb);
166 return skb->data + offset;
167}
168
169static inline void *skb_gro_header(struct sk_buff *skb,
170 unsigned int hlen, unsigned int offset)
171{
172 void *ptr;
173
174 ptr = skb_gro_header_fast(skb, offset);
175 if (skb_gro_header_hard(skb, hlen))
176 ptr = skb_gro_header_slow(skb, hlen, offset);
177 return ptr;
178}
179
180static inline void *skb_gro_network_header(struct sk_buff *skb)
181{
182 return (NAPI_GRO_CB(skb)->frag0 ?: skb->data) +
183 skb_network_offset(skb);
184}
185
186static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
187{
188 const struct iphdr *iph = skb_gro_network_header(skb);
189
190 return csum_tcpudp_nofold(saddr: iph->saddr, daddr: iph->daddr,
191 len: skb_gro_len(skb), proto, sum: 0);
192}
193
194static inline void skb_gro_postpull_rcsum(struct sk_buff *skb,
195 const void *start, unsigned int len)
196{
197 if (NAPI_GRO_CB(skb)->csum_valid)
198 NAPI_GRO_CB(skb)->csum = wsum_negate(val: csum_partial(buff: start, len,
199 sum: wsum_negate(NAPI_GRO_CB(skb)->csum)));
200}
201
202/* GRO checksum functions. These are logical equivalents of the normal
203 * checksum functions (in skbuff.h) except that they operate on the GRO
204 * offsets and fields in sk_buff.
205 */
206
207__sum16 __skb_gro_checksum_complete(struct sk_buff *skb);
208
209static inline bool skb_at_gro_remcsum_start(struct sk_buff *skb)
210{
211 return (NAPI_GRO_CB(skb)->gro_remcsum_start == skb_gro_offset(skb));
212}
213
214static inline bool __skb_gro_checksum_validate_needed(struct sk_buff *skb,
215 bool zero_okay,
216 __sum16 check)
217{
218 return ((skb->ip_summed != CHECKSUM_PARTIAL ||
219 skb_checksum_start_offset(skb) <
220 skb_gro_offset(skb)) &&
221 !skb_at_gro_remcsum_start(skb) &&
222 NAPI_GRO_CB(skb)->csum_cnt == 0 &&
223 (!zero_okay || check));
224}
225
226static inline __sum16 __skb_gro_checksum_validate_complete(struct sk_buff *skb,
227 __wsum psum)
228{
229 if (NAPI_GRO_CB(skb)->csum_valid &&
230 !csum_fold(sum: csum_add(csum: psum, NAPI_GRO_CB(skb)->csum)))
231 return 0;
232
233 NAPI_GRO_CB(skb)->csum = psum;
234
235 return __skb_gro_checksum_complete(skb);
236}
237
238static inline void skb_gro_incr_csum_unnecessary(struct sk_buff *skb)
239{
240 if (NAPI_GRO_CB(skb)->csum_cnt > 0) {
241 /* Consume a checksum from CHECKSUM_UNNECESSARY */
242 NAPI_GRO_CB(skb)->csum_cnt--;
243 } else {
244 /* Update skb for CHECKSUM_UNNECESSARY and csum_level when we
245 * verified a new top level checksum or an encapsulated one
246 * during GRO. This saves work if we fallback to normal path.
247 */
248 __skb_incr_checksum_unnecessary(skb);
249 }
250}
251
252#define __skb_gro_checksum_validate(skb, proto, zero_okay, check, \
253 compute_pseudo) \
254({ \
255 __sum16 __ret = 0; \
256 if (__skb_gro_checksum_validate_needed(skb, zero_okay, check)) \
257 __ret = __skb_gro_checksum_validate_complete(skb, \
258 compute_pseudo(skb, proto)); \
259 if (!__ret) \
260 skb_gro_incr_csum_unnecessary(skb); \
261 __ret; \
262})
263
264#define skb_gro_checksum_validate(skb, proto, compute_pseudo) \
265 __skb_gro_checksum_validate(skb, proto, false, 0, compute_pseudo)
266
267#define skb_gro_checksum_validate_zero_check(skb, proto, check, \
268 compute_pseudo) \
269 __skb_gro_checksum_validate(skb, proto, true, check, compute_pseudo)
270
271#define skb_gro_checksum_simple_validate(skb) \
272 __skb_gro_checksum_validate(skb, 0, false, 0, null_compute_pseudo)
273
274static inline bool __skb_gro_checksum_convert_check(struct sk_buff *skb)
275{
276 return (NAPI_GRO_CB(skb)->csum_cnt == 0 &&
277 !NAPI_GRO_CB(skb)->csum_valid);
278}
279
280static inline void __skb_gro_checksum_convert(struct sk_buff *skb,
281 __wsum pseudo)
282{
283 NAPI_GRO_CB(skb)->csum = ~pseudo;
284 NAPI_GRO_CB(skb)->csum_valid = 1;
285}
286
287#define skb_gro_checksum_try_convert(skb, proto, compute_pseudo) \
288do { \
289 if (__skb_gro_checksum_convert_check(skb)) \
290 __skb_gro_checksum_convert(skb, \
291 compute_pseudo(skb, proto)); \
292} while (0)
293
294struct gro_remcsum {
295 int offset;
296 __wsum delta;
297};
298
299static inline void skb_gro_remcsum_init(struct gro_remcsum *grc)
300{
301 grc->offset = 0;
302 grc->delta = 0;
303}
304
305static inline void *skb_gro_remcsum_process(struct sk_buff *skb, void *ptr,
306 unsigned int off, size_t hdrlen,
307 int start, int offset,
308 struct gro_remcsum *grc,
309 bool nopartial)
310{
311 __wsum delta;
312 size_t plen = hdrlen + max_t(size_t, offset + sizeof(u16), start);
313
314 BUG_ON(!NAPI_GRO_CB(skb)->csum_valid);
315
316 if (!nopartial) {
317 NAPI_GRO_CB(skb)->gro_remcsum_start = off + hdrlen + start;
318 return ptr;
319 }
320
321 ptr = skb_gro_header(skb, hlen: off + plen, offset: off);
322 if (!ptr)
323 return NULL;
324
325 delta = remcsum_adjust(ptr: ptr + hdrlen, NAPI_GRO_CB(skb)->csum,
326 start, offset);
327
328 /* Adjust skb->csum since we changed the packet */
329 NAPI_GRO_CB(skb)->csum = csum_add(NAPI_GRO_CB(skb)->csum, addend: delta);
330
331 grc->offset = off + hdrlen + offset;
332 grc->delta = delta;
333
334 return ptr;
335}
336
337static inline void skb_gro_remcsum_cleanup(struct sk_buff *skb,
338 struct gro_remcsum *grc)
339{
340 void *ptr;
341 size_t plen = grc->offset + sizeof(u16);
342
343 if (!grc->delta)
344 return;
345
346 ptr = skb_gro_header(skb, hlen: plen, offset: grc->offset);
347 if (!ptr)
348 return;
349
350 remcsum_unadjust(psum: (__sum16 *)ptr, delta: grc->delta);
351}
352
353#ifdef CONFIG_XFRM_OFFLOAD
354static inline void skb_gro_flush_final(struct sk_buff *skb, struct sk_buff *pp, int flush)
355{
356 if (PTR_ERR(ptr: pp) != -EINPROGRESS)
357 NAPI_GRO_CB(skb)->flush |= flush;
358}
359static inline void skb_gro_flush_final_remcsum(struct sk_buff *skb,
360 struct sk_buff *pp,
361 int flush,
362 struct gro_remcsum *grc)
363{
364 if (PTR_ERR(ptr: pp) != -EINPROGRESS) {
365 NAPI_GRO_CB(skb)->flush |= flush;
366 skb_gro_remcsum_cleanup(skb, grc);
367 skb->remcsum_offload = 0;
368 }
369}
370#else
371static inline void skb_gro_flush_final(struct sk_buff *skb, struct sk_buff *pp, int flush)
372{
373 NAPI_GRO_CB(skb)->flush |= flush;
374}
375static inline void skb_gro_flush_final_remcsum(struct sk_buff *skb,
376 struct sk_buff *pp,
377 int flush,
378 struct gro_remcsum *grc)
379{
380 NAPI_GRO_CB(skb)->flush |= flush;
381 skb_gro_remcsum_cleanup(skb, grc);
382 skb->remcsum_offload = 0;
383}
384#endif
385
386INDIRECT_CALLABLE_DECLARE(struct sk_buff *ipv6_gro_receive(struct list_head *,
387 struct sk_buff *));
388INDIRECT_CALLABLE_DECLARE(int ipv6_gro_complete(struct sk_buff *, int));
389INDIRECT_CALLABLE_DECLARE(struct sk_buff *inet_gro_receive(struct list_head *,
390 struct sk_buff *));
391INDIRECT_CALLABLE_DECLARE(int inet_gro_complete(struct sk_buff *, int));
392
393INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp4_gro_receive(struct list_head *,
394 struct sk_buff *));
395INDIRECT_CALLABLE_DECLARE(int udp4_gro_complete(struct sk_buff *, int));
396
397INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp6_gro_receive(struct list_head *,
398 struct sk_buff *));
399INDIRECT_CALLABLE_DECLARE(int udp6_gro_complete(struct sk_buff *, int));
400
401#define indirect_call_gro_receive_inet(cb, f2, f1, head, skb) \
402({ \
403 unlikely(gro_recursion_inc_test(skb)) ? \
404 NAPI_GRO_CB(skb)->flush |= 1, NULL : \
405 INDIRECT_CALL_INET(cb, f2, f1, head, skb); \
406})
407
408struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb,
409 struct udphdr *uh, struct sock *sk);
410int udp_gro_complete(struct sk_buff *skb, int nhoff, udp_lookup_t lookup);
411
412static inline struct udphdr *udp_gro_udphdr(struct sk_buff *skb)
413{
414 struct udphdr *uh;
415 unsigned int hlen, off;
416
417 off = skb_gro_offset(skb);
418 hlen = off + sizeof(*uh);
419 uh = skb_gro_header(skb, hlen, offset: off);
420
421 return uh;
422}
423
424static inline __wsum ip6_gro_compute_pseudo(struct sk_buff *skb, int proto)
425{
426 const struct ipv6hdr *iph = skb_gro_network_header(skb);
427
428 return ~csum_unfold(n: csum_ipv6_magic(saddr: &iph->saddr, daddr: &iph->daddr,
429 len: skb_gro_len(skb), proto, sum: 0));
430}
431
432int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb);
433
434/* Pass the currently batched GRO_NORMAL SKBs up to the stack. */
435static inline void gro_normal_list(struct napi_struct *napi)
436{
437 if (!napi->rx_count)
438 return;
439 netif_receive_skb_list_internal(head: &napi->rx_list);
440 INIT_LIST_HEAD(list: &napi->rx_list);
441 napi->rx_count = 0;
442}
443
444/* Queue one GRO_NORMAL SKB up for list processing. If batch size exceeded,
445 * pass the whole batch up to the stack.
446 */
447static inline void gro_normal_one(struct napi_struct *napi, struct sk_buff *skb, int segs)
448{
449 list_add_tail(new: &skb->list, head: &napi->rx_list);
450 napi->rx_count += segs;
451 if (napi->rx_count >= READ_ONCE(gro_normal_batch))
452 gro_normal_list(napi);
453}
454
455/* This function is the alternative of 'inet_iif' and 'inet_sdif'
456 * functions in case we can not rely on fields of IPCB.
457 *
458 * The caller must verify skb_valid_dst(skb) is false and skb->dev is initialized.
459 * The caller must hold the RCU read lock.
460 */
461static inline void inet_get_iif_sdif(const struct sk_buff *skb, int *iif, int *sdif)
462{
463 *iif = inet_iif(skb) ?: skb->dev->ifindex;
464 *sdif = 0;
465
466#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
467 if (netif_is_l3_slave(dev: skb->dev)) {
468 struct net_device *master = netdev_master_upper_dev_get_rcu(dev: skb->dev);
469
470 *sdif = *iif;
471 *iif = master ? master->ifindex : 0;
472 }
473#endif
474}
475
476/* This function is the alternative of 'inet6_iif' and 'inet6_sdif'
477 * functions in case we can not rely on fields of IP6CB.
478 *
479 * The caller must verify skb_valid_dst(skb) is false and skb->dev is initialized.
480 * The caller must hold the RCU read lock.
481 */
482static inline void inet6_get_iif_sdif(const struct sk_buff *skb, int *iif, int *sdif)
483{
484 /* using skb->dev->ifindex because skb_dst(skb) is not initialized */
485 *iif = skb->dev->ifindex;
486 *sdif = 0;
487
488#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
489 if (netif_is_l3_slave(dev: skb->dev)) {
490 struct net_device *master = netdev_master_upper_dev_get_rcu(dev: skb->dev);
491
492 *sdif = *iif;
493 *iif = master ? master->ifindex : 0;
494 }
495#endif
496}
497
498extern struct list_head offload_base;
499
500#endif /* _NET_IPV6_GRO_H */
501

source code of linux/include/net/gro.h