1/* SPDX-License-Identifier: GPL-2.0-or-later */
2
3#ifndef _NET_GRO_H
4#define _NET_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#include <net/hotdata.h>
13
14/* This should be increased if a protocol with a bigger head is added. */
15#define GRO_MAX_HEAD (MAX_HEADER + 128)
16
17struct napi_gro_cb {
18 union {
19 struct {
20 /* Virtual address of skb_shinfo(skb)->frags[0].page + offset. */
21 void *frag0;
22
23 /* Length of frag0. */
24 unsigned int frag0_len;
25 };
26
27 struct {
28 /* used in skb_gro_receive() slow path */
29 struct sk_buff *last;
30
31 /* jiffies when first packet was created/queued */
32 unsigned long age;
33 };
34 };
35
36 /* This indicates where we are processing relative to skb->data. */
37 int data_offset;
38
39 /* This is non-zero if the packet cannot be merged with the new skb. */
40 u16 flush;
41
42 /* Number of segments aggregated. */
43 u16 count;
44
45 /* Used in ipv6_gro_receive() and foo-over-udp and esp-in-udp */
46 u16 proto;
47
48 u16 pad;
49
50/* Used in napi_gro_cb::free */
51#define NAPI_GRO_FREE 1
52#define NAPI_GRO_FREE_STOLEN_HEAD 2
53 /* portion of the cb set to zero at every gro iteration */
54 struct_group(zeroed,
55
56 /* Start offset for remote checksum offload */
57 u16 gro_remcsum_start;
58
59 /* This is non-zero if the packet may be of the same flow. */
60 u8 same_flow:1;
61
62 /* Used in tunnel GRO receive */
63 u8 encap_mark:1;
64
65 /* GRO checksum is valid */
66 u8 csum_valid:1;
67
68 /* Number of checksums via CHECKSUM_UNNECESSARY */
69 u8 csum_cnt:3;
70
71 /* Free the skb? */
72 u8 free:2;
73
74 /* Used in foo-over-udp, set in udp[46]_gro_receive */
75 u8 is_ipv6:1;
76
77 /* Used in GRE, set in fou/gue_gro_receive */
78 u8 is_fou:1;
79
80 /* Used to determine if ipid_offset can be ignored */
81 u8 ip_fixedid:1;
82
83 /* Number of gro_receive callbacks this packet already went through */
84 u8 recursion_counter:4;
85
86 /* GRO is done by frag_list pointer chaining. */
87 u8 is_flist:1;
88 );
89
90 /* used to support CHECKSUM_COMPLETE for tunneling protocols */
91 __wsum csum;
92
93 /* L3 offsets */
94 union {
95 struct {
96 u16 network_offset;
97 u16 inner_network_offset;
98 };
99 u16 network_offsets[2];
100 };
101};
102
103#define NAPI_GRO_CB(skb) ((struct napi_gro_cb *)(skb)->cb)
104
105#define GRO_RECURSION_LIMIT 15
106static inline int gro_recursion_inc_test(struct sk_buff *skb)
107{
108 return ++NAPI_GRO_CB(skb)->recursion_counter == GRO_RECURSION_LIMIT;
109}
110
111typedef struct sk_buff *(*gro_receive_t)(struct list_head *, struct sk_buff *);
112static inline struct sk_buff *call_gro_receive(gro_receive_t cb,
113 struct list_head *head,
114 struct sk_buff *skb)
115{
116 if (unlikely(gro_recursion_inc_test(skb))) {
117 NAPI_GRO_CB(skb)->flush |= 1;
118 return NULL;
119 }
120
121 return cb(head, skb);
122}
123
124typedef struct sk_buff *(*gro_receive_sk_t)(struct sock *, struct list_head *,
125 struct sk_buff *);
126static inline struct sk_buff *call_gro_receive_sk(gro_receive_sk_t cb,
127 struct sock *sk,
128 struct list_head *head,
129 struct sk_buff *skb)
130{
131 if (unlikely(gro_recursion_inc_test(skb))) {
132 NAPI_GRO_CB(skb)->flush |= 1;
133 return NULL;
134 }
135
136 return cb(sk, head, skb);
137}
138
139static inline unsigned int skb_gro_offset(const struct sk_buff *skb)
140{
141 return NAPI_GRO_CB(skb)->data_offset;
142}
143
144static inline unsigned int skb_gro_len(const struct sk_buff *skb)
145{
146 return skb->len - NAPI_GRO_CB(skb)->data_offset;
147}
148
149static inline void skb_gro_pull(struct sk_buff *skb, unsigned int len)
150{
151 NAPI_GRO_CB(skb)->data_offset += len;
152}
153
154static inline void *skb_gro_header_fast(const struct sk_buff *skb,
155 unsigned int offset)
156{
157 return NAPI_GRO_CB(skb)->frag0 + offset;
158}
159
160static inline bool skb_gro_may_pull(const struct sk_buff *skb,
161 unsigned int hlen)
162{
163 return likely(hlen <= NAPI_GRO_CB(skb)->frag0_len);
164}
165
166static inline void *skb_gro_header_slow(struct sk_buff *skb, unsigned int hlen,
167 unsigned int offset)
168{
169 if (!pskb_may_pull(skb, len: hlen))
170 return NULL;
171
172 return skb->data + offset;
173}
174
175static inline void *skb_gro_header(struct sk_buff *skb, unsigned int hlen,
176 unsigned int offset)
177{
178 void *ptr;
179
180 ptr = skb_gro_header_fast(skb, offset);
181 if (!skb_gro_may_pull(skb, hlen))
182 ptr = skb_gro_header_slow(skb, hlen, offset);
183 return ptr;
184}
185
186static inline int skb_gro_receive_network_offset(const struct sk_buff *skb)
187{
188 return NAPI_GRO_CB(skb)->network_offsets[NAPI_GRO_CB(skb)->encap_mark];
189}
190
191static inline void *skb_gro_network_header(const struct sk_buff *skb)
192{
193 if (skb_gro_may_pull(skb, hlen: skb_gro_offset(skb)))
194 return skb_gro_header_fast(skb, offset: skb_gro_receive_network_offset(skb));
195
196 return skb->data + skb_gro_receive_network_offset(skb);
197}
198
199static inline __wsum inet_gro_compute_pseudo(const struct sk_buff *skb,
200 int proto)
201{
202 const struct iphdr *iph = skb_gro_network_header(skb);
203
204 return csum_tcpudp_nofold(saddr: iph->saddr, daddr: iph->daddr,
205 len: skb_gro_len(skb), proto, sum: 0);
206}
207
208static inline void skb_gro_postpull_rcsum(struct sk_buff *skb,
209 const void *start, unsigned int len)
210{
211 if (NAPI_GRO_CB(skb)->csum_valid)
212 NAPI_GRO_CB(skb)->csum = wsum_negate(val: csum_partial(buff: start, len,
213 sum: wsum_negate(NAPI_GRO_CB(skb)->csum)));
214}
215
216/* GRO checksum functions. These are logical equivalents of the normal
217 * checksum functions (in skbuff.h) except that they operate on the GRO
218 * offsets and fields in sk_buff.
219 */
220
221__sum16 __skb_gro_checksum_complete(struct sk_buff *skb);
222
223static inline bool skb_at_gro_remcsum_start(struct sk_buff *skb)
224{
225 return (NAPI_GRO_CB(skb)->gro_remcsum_start == skb_gro_offset(skb));
226}
227
228static inline bool __skb_gro_checksum_validate_needed(struct sk_buff *skb,
229 bool zero_okay,
230 __sum16 check)
231{
232 return ((skb->ip_summed != CHECKSUM_PARTIAL ||
233 skb_checksum_start_offset(skb) <
234 skb_gro_offset(skb)) &&
235 !skb_at_gro_remcsum_start(skb) &&
236 NAPI_GRO_CB(skb)->csum_cnt == 0 &&
237 (!zero_okay || check));
238}
239
240static inline __sum16 __skb_gro_checksum_validate_complete(struct sk_buff *skb,
241 __wsum psum)
242{
243 if (NAPI_GRO_CB(skb)->csum_valid &&
244 !csum_fold(csum: csum_add(csum: psum, NAPI_GRO_CB(skb)->csum)))
245 return 0;
246
247 NAPI_GRO_CB(skb)->csum = psum;
248
249 return __skb_gro_checksum_complete(skb);
250}
251
252static inline void skb_gro_incr_csum_unnecessary(struct sk_buff *skb)
253{
254 if (NAPI_GRO_CB(skb)->csum_cnt > 0) {
255 /* Consume a checksum from CHECKSUM_UNNECESSARY */
256 NAPI_GRO_CB(skb)->csum_cnt--;
257 } else {
258 /* Update skb for CHECKSUM_UNNECESSARY and csum_level when we
259 * verified a new top level checksum or an encapsulated one
260 * during GRO. This saves work if we fallback to normal path.
261 */
262 __skb_incr_checksum_unnecessary(skb);
263 }
264}
265
266#define __skb_gro_checksum_validate(skb, proto, zero_okay, check, \
267 compute_pseudo) \
268({ \
269 __sum16 __ret = 0; \
270 if (__skb_gro_checksum_validate_needed(skb, zero_okay, check)) \
271 __ret = __skb_gro_checksum_validate_complete(skb, \
272 compute_pseudo(skb, proto)); \
273 if (!__ret) \
274 skb_gro_incr_csum_unnecessary(skb); \
275 __ret; \
276})
277
278#define skb_gro_checksum_validate(skb, proto, compute_pseudo) \
279 __skb_gro_checksum_validate(skb, proto, false, 0, compute_pseudo)
280
281#define skb_gro_checksum_validate_zero_check(skb, proto, check, \
282 compute_pseudo) \
283 __skb_gro_checksum_validate(skb, proto, true, check, compute_pseudo)
284
285#define skb_gro_checksum_simple_validate(skb) \
286 __skb_gro_checksum_validate(skb, 0, false, 0, null_compute_pseudo)
287
288static inline bool __skb_gro_checksum_convert_check(struct sk_buff *skb)
289{
290 return (NAPI_GRO_CB(skb)->csum_cnt == 0 &&
291 !NAPI_GRO_CB(skb)->csum_valid);
292}
293
294static inline void __skb_gro_checksum_convert(struct sk_buff *skb,
295 __wsum pseudo)
296{
297 NAPI_GRO_CB(skb)->csum = ~pseudo;
298 NAPI_GRO_CB(skb)->csum_valid = 1;
299}
300
301#define skb_gro_checksum_try_convert(skb, proto, compute_pseudo) \
302do { \
303 if (__skb_gro_checksum_convert_check(skb)) \
304 __skb_gro_checksum_convert(skb, \
305 compute_pseudo(skb, proto)); \
306} while (0)
307
308struct gro_remcsum {
309 int offset;
310 __wsum delta;
311};
312
313static inline void skb_gro_remcsum_init(struct gro_remcsum *grc)
314{
315 grc->offset = 0;
316 grc->delta = 0;
317}
318
319static inline void *skb_gro_remcsum_process(struct sk_buff *skb, void *ptr,
320 unsigned int off, size_t hdrlen,
321 int start, int offset,
322 struct gro_remcsum *grc,
323 bool nopartial)
324{
325 __wsum delta;
326 size_t plen = hdrlen + max_t(size_t, offset + sizeof(u16), start);
327
328 BUG_ON(!NAPI_GRO_CB(skb)->csum_valid);
329
330 if (!nopartial) {
331 NAPI_GRO_CB(skb)->gro_remcsum_start = off + hdrlen + start;
332 return ptr;
333 }
334
335 ptr = skb_gro_header(skb, hlen: off + plen, offset: off);
336 if (!ptr)
337 return NULL;
338
339 delta = remcsum_adjust(ptr: ptr + hdrlen, NAPI_GRO_CB(skb)->csum,
340 start, offset);
341
342 /* Adjust skb->csum since we changed the packet */
343 NAPI_GRO_CB(skb)->csum = csum_add(NAPI_GRO_CB(skb)->csum, addend: delta);
344
345 grc->offset = off + hdrlen + offset;
346 grc->delta = delta;
347
348 return ptr;
349}
350
351static inline void skb_gro_remcsum_cleanup(struct sk_buff *skb,
352 struct gro_remcsum *grc)
353{
354 void *ptr;
355 size_t plen = grc->offset + sizeof(u16);
356
357 if (!grc->delta)
358 return;
359
360 ptr = skb_gro_header(skb, hlen: plen, offset: grc->offset);
361 if (!ptr)
362 return;
363
364 remcsum_unadjust(psum: (__sum16 *)ptr, delta: grc->delta);
365}
366
367#ifdef CONFIG_XFRM_OFFLOAD
368static inline void skb_gro_flush_final(struct sk_buff *skb, struct sk_buff *pp, int flush)
369{
370 if (PTR_ERR(ptr: pp) != -EINPROGRESS)
371 NAPI_GRO_CB(skb)->flush |= flush;
372}
373static inline void skb_gro_flush_final_remcsum(struct sk_buff *skb,
374 struct sk_buff *pp,
375 int flush,
376 struct gro_remcsum *grc)
377{
378 if (PTR_ERR(ptr: pp) != -EINPROGRESS) {
379 NAPI_GRO_CB(skb)->flush |= flush;
380 skb_gro_remcsum_cleanup(skb, grc);
381 skb->remcsum_offload = 0;
382 }
383}
384#else
385static inline void skb_gro_flush_final(struct sk_buff *skb, struct sk_buff *pp, int flush)
386{
387 NAPI_GRO_CB(skb)->flush |= flush;
388}
389static inline void skb_gro_flush_final_remcsum(struct sk_buff *skb,
390 struct sk_buff *pp,
391 int flush,
392 struct gro_remcsum *grc)
393{
394 NAPI_GRO_CB(skb)->flush |= flush;
395 skb_gro_remcsum_cleanup(skb, grc);
396 skb->remcsum_offload = 0;
397}
398#endif
399
400INDIRECT_CALLABLE_DECLARE(struct sk_buff *ipv6_gro_receive(struct list_head *,
401 struct sk_buff *));
402INDIRECT_CALLABLE_DECLARE(int ipv6_gro_complete(struct sk_buff *, int));
403INDIRECT_CALLABLE_DECLARE(struct sk_buff *inet_gro_receive(struct list_head *,
404 struct sk_buff *));
405INDIRECT_CALLABLE_DECLARE(int inet_gro_complete(struct sk_buff *, int));
406
407INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp4_gro_receive(struct list_head *,
408 struct sk_buff *));
409INDIRECT_CALLABLE_DECLARE(int udp4_gro_complete(struct sk_buff *, int));
410
411INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp6_gro_receive(struct list_head *,
412 struct sk_buff *));
413INDIRECT_CALLABLE_DECLARE(int udp6_gro_complete(struct sk_buff *, int));
414
415#define indirect_call_gro_receive_inet(cb, f2, f1, head, skb) \
416({ \
417 unlikely(gro_recursion_inc_test(skb)) ? \
418 NAPI_GRO_CB(skb)->flush |= 1, NULL : \
419 INDIRECT_CALL_INET(cb, f2, f1, head, skb); \
420})
421
422struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb,
423 struct udphdr *uh, struct sock *sk);
424int udp_gro_complete(struct sk_buff *skb, int nhoff, udp_lookup_t lookup);
425
426static inline struct udphdr *udp_gro_udphdr(struct sk_buff *skb)
427{
428 struct udphdr *uh;
429 unsigned int hlen, off;
430
431 off = skb_gro_offset(skb);
432 hlen = off + sizeof(*uh);
433 uh = skb_gro_header(skb, hlen, offset: off);
434
435 return uh;
436}
437
438static inline __wsum ip6_gro_compute_pseudo(const struct sk_buff *skb,
439 int proto)
440{
441 const struct ipv6hdr *iph = skb_gro_network_header(skb);
442
443 return ~csum_unfold(n: csum_ipv6_magic(saddr: &iph->saddr, daddr: &iph->daddr,
444 len: skb_gro_len(skb), proto, csum: 0));
445}
446
447static inline int inet_gro_flush(const struct iphdr *iph, const struct iphdr *iph2,
448 struct sk_buff *p, bool outer)
449{
450 const u32 id = ntohl(*(__be32 *)&iph->id);
451 const u32 id2 = ntohl(*(__be32 *)&iph2->id);
452 const u16 ipid_offset = (id >> 16) - (id2 >> 16);
453 const u16 count = NAPI_GRO_CB(p)->count;
454 const u32 df = id & IP_DF;
455 int flush;
456
457 /* All fields must match except length and checksum. */
458 flush = (iph->ttl ^ iph2->ttl) | (iph->tos ^ iph2->tos) | (df ^ (id2 & IP_DF));
459
460 if (flush | (outer && df))
461 return flush;
462
463 /* When we receive our second frame we can make a decision on if we
464 * continue this flow as an atomic flow with a fixed ID or if we use
465 * an incrementing ID.
466 */
467 if (count == 1 && df && !ipid_offset)
468 NAPI_GRO_CB(p)->ip_fixedid = true;
469
470 return ipid_offset ^ (count * !NAPI_GRO_CB(p)->ip_fixedid);
471}
472
473static inline int ipv6_gro_flush(const struct ipv6hdr *iph, const struct ipv6hdr *iph2)
474{
475 /* <Version:4><Traffic_Class:8><Flow_Label:20> */
476 __be32 first_word = *(__be32 *)iph ^ *(__be32 *)iph2;
477
478 /* Flush if Traffic Class fields are different. */
479 return !!((first_word & htonl(0x0FF00000)) |
480 (__force __be32)(iph->hop_limit ^ iph2->hop_limit));
481}
482
483static inline int __gro_receive_network_flush(const void *th, const void *th2,
484 struct sk_buff *p, const u16 diff,
485 bool outer)
486{
487 const void *nh = th - diff;
488 const void *nh2 = th2 - diff;
489
490 if (((struct iphdr *)nh)->version == 6)
491 return ipv6_gro_flush(iph: nh, iph2: nh2);
492 else
493 return inet_gro_flush(iph: nh, iph2: nh2, p, outer);
494}
495
496static inline int gro_receive_network_flush(const void *th, const void *th2,
497 struct sk_buff *p)
498{
499 const bool encap_mark = NAPI_GRO_CB(p)->encap_mark;
500 int off = skb_transport_offset(skb: p);
501 int flush;
502
503 flush = __gro_receive_network_flush(th, th2, p, diff: off - NAPI_GRO_CB(p)->network_offset, outer: encap_mark);
504 if (encap_mark)
505 flush |= __gro_receive_network_flush(th, th2, p, diff: off - NAPI_GRO_CB(p)->inner_network_offset, outer: false);
506
507 return flush;
508}
509
510int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb);
511int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb);
512void __gro_flush(struct gro_node *gro, bool flush_old);
513
514static inline void gro_flush(struct gro_node *gro, bool flush_old)
515{
516 if (!gro->bitmask)
517 return;
518
519 __gro_flush(gro, flush_old);
520}
521
522static inline void napi_gro_flush(struct napi_struct *napi, bool flush_old)
523{
524 gro_flush(gro: &napi->gro, flush_old);
525}
526
527/* Pass the currently batched GRO_NORMAL SKBs up to the stack. */
528static inline void gro_normal_list(struct gro_node *gro)
529{
530 if (!gro->rx_count)
531 return;
532 netif_receive_skb_list_internal(head: &gro->rx_list);
533 INIT_LIST_HEAD(list: &gro->rx_list);
534 gro->rx_count = 0;
535}
536
537/* Queue one GRO_NORMAL SKB up for list processing. If batch size exceeded,
538 * pass the whole batch up to the stack.
539 */
540static inline void gro_normal_one(struct gro_node *gro, struct sk_buff *skb,
541 int segs)
542{
543 list_add_tail(new: &skb->list, head: &gro->rx_list);
544 gro->rx_count += segs;
545 if (gro->rx_count >= READ_ONCE(net_hotdata.gro_normal_batch))
546 gro_normal_list(gro);
547}
548
549void gro_init(struct gro_node *gro);
550void gro_cleanup(struct gro_node *gro);
551
552/* This function is the alternative of 'inet_iif' and 'inet_sdif'
553 * functions in case we can not rely on fields of IPCB.
554 *
555 * The caller must verify skb_valid_dst(skb) is false and skb->dev is initialized.
556 * The caller must hold the RCU read lock.
557 */
558static inline void inet_get_iif_sdif(const struct sk_buff *skb, int *iif, int *sdif)
559{
560 *iif = inet_iif(skb) ?: skb->dev->ifindex;
561 *sdif = 0;
562
563#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
564 if (netif_is_l3_slave(dev: skb->dev)) {
565 struct net_device *master = netdev_master_upper_dev_get_rcu(dev: skb->dev);
566
567 *sdif = *iif;
568 *iif = master ? master->ifindex : 0;
569 }
570#endif
571}
572
573/* This function is the alternative of 'inet6_iif' and 'inet6_sdif'
574 * functions in case we can not rely on fields of IP6CB.
575 *
576 * The caller must verify skb_valid_dst(skb) is false and skb->dev is initialized.
577 * The caller must hold the RCU read lock.
578 */
579static inline void inet6_get_iif_sdif(const struct sk_buff *skb, int *iif, int *sdif)
580{
581 /* using skb->dev->ifindex because skb_dst(skb) is not initialized */
582 *iif = skb->dev->ifindex;
583 *sdif = 0;
584
585#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
586 if (netif_is_l3_slave(dev: skb->dev)) {
587 struct net_device *master = netdev_master_upper_dev_get_rcu(dev: skb->dev);
588
589 *sdif = *iif;
590 *iif = master ? master->ifindex : 0;
591 }
592#endif
593}
594
595struct packet_offload *gro_find_receive_by_type(__be16 type);
596struct packet_offload *gro_find_complete_by_type(__be16 type);
597
598#endif /* _NET_GRO_H */
599

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

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