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wifi: mac80211: mlme: Fix double unlock on assoc success handling
[linux-block.git] / net / core / gro.c
CommitLineData
e456a18a
ED		 1// SPDX-License-Identifier: GPL-2.0-or-later
2#include <net/gro.h>
587652bb
ED		 3#include <net/dst_metadata.h>
4#include <net/busy_poll.h>
5#include <trace/events/net.h>
6
7#define MAX_GRO_SKBS 8
8
9/* This should be increased if a protocol with a bigger head is added. */
10#define GRO_MAX_HEAD (MAX_HEADER + 128)
11
12static DEFINE_SPINLOCK(offload_lock);
13static struct list_head offload_base __read_mostly = LIST_HEAD_INIT(offload_base);
14/* Maximum number of GRO_NORMAL skbs to batch up for list-RX */
15int gro_normal_batch __read_mostly = 8;
16
17/**
18 * dev_add_offload - register offload handlers
19 * @po: protocol offload declaration
20 *
21 * Add protocol offload handlers to the networking stack. The passed
22 * &proto_offload is linked into kernel lists and may not be freed until
23 * it has been removed from the kernel lists.
24 *
25 * This call does not sleep therefore it can not
26 * guarantee all CPU's that are in middle of receiving packets
27 * will see the new offload handlers (until the next received packet).
28 */
29void dev_add_offload(struct packet_offload *po)
30{
31 struct packet_offload *elem;
32
33 spin_lock(&offload_lock);
34 list_for_each_entry(elem, &offload_base, list) {
35 if (po->priority < elem->priority)
36 break;
37 }
38 list_add_rcu(&po->list, elem->list.prev);
39 spin_unlock(&offload_lock);
40}
41EXPORT_SYMBOL(dev_add_offload);
42
43/**
44 * __dev_remove_offload - remove offload handler
45 * @po: packet offload declaration
46 *
47 * Remove a protocol offload handler that was previously added to the
48 * kernel offload handlers by dev_add_offload(). The passed &offload_type
49 * is removed from the kernel lists and can be freed or reused once this
50 * function returns.
51 *
52 * The packet type might still be in use by receivers
53 * and must not be freed until after all the CPU's have gone
54 * through a quiescent state.
55 */
56static void __dev_remove_offload(struct packet_offload *po)
57{
58 struct list_head *head = &offload_base;
59 struct packet_offload *po1;
60
61 spin_lock(&offload_lock);
62
63 list_for_each_entry(po1, head, list) {
64 if (po == po1) {
65 list_del_rcu(&po->list);
66 goto out;
67 }
68 }
69
70 pr_warn("dev_remove_offload: %p not found\n", po);
71out:
72 spin_unlock(&offload_lock);
73}
74
75/**
76 * dev_remove_offload - remove packet offload handler
77 * @po: packet offload declaration
78 *
79 * Remove a packet offload handler that was previously added to the kernel
80 * offload handlers by dev_add_offload(). The passed &offload_type is
81 * removed from the kernel lists and can be freed or reused once this
82 * function returns.
83 *
84 * This call sleeps to guarantee that no CPU is looking at the packet
85 * type after return.
86 */
87void dev_remove_offload(struct packet_offload *po)
88{
89 __dev_remove_offload(po);
90
91 synchronize_net();
92}
93EXPORT_SYMBOL(dev_remove_offload);
94
23c7f8d7
SK		 95/**
96 * skb_eth_gso_segment - segmentation handler for ethernet protocols.
97 * @skb: buffer to segment
98 * @features: features for the output path (see dev->features)
99 * @type: Ethernet Protocol ID
100 */
101struct sk_buff *skb_eth_gso_segment(struct sk_buff *skb,
102 netdev_features_t features, __be16 type)
103{
104 struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
105 struct packet_offload *ptype;
106
107 rcu_read_lock();
108 list_for_each_entry_rcu(ptype, &offload_base, list) {
109 if (ptype->type == type && ptype->callbacks.gso_segment) {
110 segs = ptype->callbacks.gso_segment(skb, features);
111 break;
112 }
113 }
114 rcu_read_unlock();
115
116 return segs;
117}
118EXPORT_SYMBOL(skb_eth_gso_segment);
119
587652bb
ED		 120/**
121 * skb_mac_gso_segment - mac layer segmentation handler.
122 * @skb: buffer to segment
123 * @features: features for the output path (see dev->features)
124 */
125struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb,
126 netdev_features_t features)
127{
128 struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
129 struct packet_offload *ptype;
130 int vlan_depth = skb->mac_len;
131 __be16 type = skb_network_protocol(skb, &vlan_depth);
132
133 if (unlikely(!type))
134 return ERR_PTR(-EINVAL);
135
136 __skb_pull(skb, vlan_depth);
137
138 rcu_read_lock();
139 list_for_each_entry_rcu(ptype, &offload_base, list) {
140 if (ptype->type == type && ptype->callbacks.gso_segment) {
141 segs = ptype->callbacks.gso_segment(skb, features);
142 break;
143 }
144 }
145 rcu_read_unlock();
146
147 __skb_push(skb, skb->data - skb_mac_header(skb));
148
149 return segs;
150}
151EXPORT_SYMBOL(skb_mac_gso_segment);
e456a18a
ED		 152
153int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb)
154{
155 struct skb_shared_info *pinfo, *skbinfo = skb_shinfo(skb);
156 unsigned int offset = skb_gro_offset(skb);
157 unsigned int headlen = skb_headlen(skb);
158 unsigned int len = skb_gro_len(skb);
159 unsigned int delta_truesize;
eac1b93c 160 unsigned int gro_max_size;
e456a18a
ED		 161 unsigned int new_truesize;
162 struct sk_buff *lp;
163
eac1b93c
CL		 164 /* pairs with WRITE_ONCE() in netif_set_gro_max_size() */
165 gro_max_size = READ_ONCE(p->dev->gro_max_size);
166
167 if (unlikely(p->len + len >= gro_max_size || NAPI_GRO_CB(skb)->flush))
e456a18a
ED		 168 return -E2BIG;
169
0fe79f28
AD		 170 if (unlikely(p->len + len >= GRO_LEGACY_MAX_SIZE)) {
171 if (p->protocol != htons(ETH_P_IPV6) ||
172 skb_headroom(p) < sizeof(struct hop_jumbo_hdr) ||
173 ipv6_hdr(p)->nexthdr != IPPROTO_TCP ||
174 p->encapsulation)
175 return -E2BIG;
176 }
177
e456a18a
ED		 178 lp = NAPI_GRO_CB(p)->last;
179 pinfo = skb_shinfo(lp);
180
181 if (headlen <= offset) {
182 skb_frag_t *frag;
183 skb_frag_t *frag2;
184 int i = skbinfo->nr_frags;
185 int nr_frags = pinfo->nr_frags + i;
186
187 if (nr_frags > MAX_SKB_FRAGS)
188 goto merge;
189
190 offset -= headlen;
191 pinfo->nr_frags = nr_frags;
192 skbinfo->nr_frags = 0;
193
194 frag = pinfo->frags + nr_frags;
195 frag2 = skbinfo->frags + i;
196 do {
197 *--frag = *--frag2;
198 } while (--i);
199
200 skb_frag_off_add(frag, offset);
201 skb_frag_size_sub(frag, offset);
202
203 /* all fragments truesize : remove (head size + sk_buff) */
204 new_truesize = SKB_TRUESIZE(skb_end_offset(skb));
205 delta_truesize = skb->truesize - new_truesize;
206
207 skb->truesize = new_truesize;
208 skb->len -= skb->data_len;
209 skb->data_len = 0;
210
211 NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE;
212 goto done;
213 } else if (skb->head_frag) {
214 int nr_frags = pinfo->nr_frags;
215 skb_frag_t *frag = pinfo->frags + nr_frags;
216 struct page *page = virt_to_head_page(skb->head);
217 unsigned int first_size = headlen - offset;
218 unsigned int first_offset;
219
220 if (nr_frags + 1 + skbinfo->nr_frags > MAX_SKB_FRAGS)
221 goto merge;
222
223 first_offset = skb->data -
224 (unsigned char *)page_address(page) +
225 offset;
226
227 pinfo->nr_frags = nr_frags + 1 + skbinfo->nr_frags;
228
229 __skb_frag_set_page(frag, page);
230 skb_frag_off_set(frag, first_offset);
231 skb_frag_size_set(frag, first_size);
232
233 memcpy(frag + 1, skbinfo->frags, sizeof(*frag) * skbinfo->nr_frags);
234 /* We dont need to clear skbinfo->nr_frags here */
235
236 new_truesize = SKB_DATA_ALIGN(sizeof(struct sk_buff));
237 delta_truesize = skb->truesize - new_truesize;
238 skb->truesize = new_truesize;
239 NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD;
240 goto done;
241 }
242
243merge:
244 /* sk owenrship - if any - completely transferred to the aggregated packet */
245 skb->destructor = NULL;
246 delta_truesize = skb->truesize;
247 if (offset > headlen) {
248 unsigned int eat = offset - headlen;
249
250 skb_frag_off_add(&skbinfo->frags[0], eat);
251 skb_frag_size_sub(&skbinfo->frags[0], eat);
252 skb->data_len -= eat;
253 skb->len -= eat;
254 offset = headlen;
255 }
256
257 __skb_pull(skb, offset);
258
259 if (NAPI_GRO_CB(p)->last == p)
260 skb_shinfo(p)->frag_list = skb;
261 else
262 NAPI_GRO_CB(p)->last->next = skb;
263 NAPI_GRO_CB(p)->last = skb;
264 __skb_header_release(skb);
265 lp = p;
266
267done:
268 NAPI_GRO_CB(p)->count++;
269 p->data_len += len;
270 p->truesize += delta_truesize;
271 p->len += len;
272 if (lp != p) {
273 lp->data_len += len;
274 lp->truesize += delta_truesize;
275 lp->len += len;
276 }
277 NAPI_GRO_CB(skb)->same_flow = 1;
278 return 0;
279}
587652bb
ED		 280
281
282static void napi_gro_complete(struct napi_struct *napi, struct sk_buff *skb)
283{
284 struct packet_offload *ptype;
285 __be16 type = skb->protocol;
286 struct list_head *head = &offload_base;
287 int err = -ENOENT;
288
289 BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb));
290
291 if (NAPI_GRO_CB(skb)->count == 1) {
292 skb_shinfo(skb)->gso_size = 0;
293 goto out;
294 }
295
296 rcu_read_lock();
297 list_for_each_entry_rcu(ptype, head, list) {
298 if (ptype->type != type || !ptype->callbacks.gro_complete)
299 continue;
300
301 err = INDIRECT_CALL_INET(ptype->callbacks.gro_complete,
302 ipv6_gro_complete, inet_gro_complete,
303 skb, 0);
304 break;
305 }
306 rcu_read_unlock();
307
308 if (err) {
309 WARN_ON(&ptype->list == head);
310 kfree_skb(skb);
311 return;
312 }
313
314out:
315 gro_normal_one(napi, skb, NAPI_GRO_CB(skb)->count);
316}
317
318static void __napi_gro_flush_chain(struct napi_struct *napi, u32 index,
319 bool flush_old)
320{
321 struct list_head *head = &napi->gro_hash[index].list;
322 struct sk_buff *skb, *p;
323
324 list_for_each_entry_safe_reverse(skb, p, head, list) {
325 if (flush_old && NAPI_GRO_CB(skb)->age == jiffies)
326 return;
327 skb_list_del_init(skb);
328 napi_gro_complete(napi, skb);
329 napi->gro_hash[index].count--;
330 }
331
332 if (!napi->gro_hash[index].count)
333 __clear_bit(index, &napi->gro_bitmask);
334}
335
336/* napi->gro_hash[].list contains packets ordered by age.
337 * youngest packets at the head of it.
338 * Complete skbs in reverse order to reduce latencies.
339 */
340void napi_gro_flush(struct napi_struct *napi, bool flush_old)
341{
342 unsigned long bitmask = napi->gro_bitmask;
343 unsigned int i, base = ~0U;
344
345 while ((i = ffs(bitmask)) != 0) {
346 bitmask >>= i;
347 base += i;
348 __napi_gro_flush_chain(napi, base, flush_old);
349 }
350}
351EXPORT_SYMBOL(napi_gro_flush);
352
353static void gro_list_prepare(const struct list_head *head,
354 const struct sk_buff *skb)
355{
356 unsigned int maclen = skb->dev->hard_header_len;
357 u32 hash = skb_get_hash_raw(skb);
358 struct sk_buff *p;
359
360 list_for_each_entry(p, head, list) {
361 unsigned long diffs;
362
363 NAPI_GRO_CB(p)->flush = 0;
364
365 if (hash != skb_get_hash_raw(p)) {
366 NAPI_GRO_CB(p)->same_flow = 0;
367 continue;
368 }
369
370 diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
371 diffs |= skb_vlan_tag_present(p) ^ skb_vlan_tag_present(skb);
372 if (skb_vlan_tag_present(p))
373 diffs |= skb_vlan_tag_get(p) ^ skb_vlan_tag_get(skb);
374 diffs |= skb_metadata_differs(p, skb);
375 if (maclen == ETH_HLEN)
376 diffs |= compare_ether_header(skb_mac_header(p),
377 skb_mac_header(skb));
378 else if (!diffs)
379 diffs = memcmp(skb_mac_header(p),
380 skb_mac_header(skb),
381 maclen);
382
383 /* in most common scenarions 'slow_gro' is 0
384 * otherwise we are already on some slower paths
385 * either skip all the infrequent tests altogether or
386 * avoid trying too hard to skip each of them individually
387 */
388 if (!diffs && unlikely(skb->slow_gro | p->slow_gro)) {
389#if IS_ENABLED(CONFIG_SKB_EXTENSIONS) && IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
390 struct tc_skb_ext *skb_ext;
391 struct tc_skb_ext *p_ext;
392#endif
393
394 diffs |= p->sk != skb->sk;
395 diffs |= skb_metadata_dst_cmp(p, skb);
396 diffs |= skb_get_nfct(p) ^ skb_get_nfct(skb);
397
398#if IS_ENABLED(CONFIG_SKB_EXTENSIONS) && IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
399 skb_ext = skb_ext_find(skb, TC_SKB_EXT);
400 p_ext = skb_ext_find(p, TC_SKB_EXT);
401
402 diffs |= (!!p_ext) ^ (!!skb_ext);
403 if (!diffs && unlikely(skb_ext))
404 diffs |= p_ext->chain ^ skb_ext->chain;
405#endif
406 }
407
408 NAPI_GRO_CB(p)->same_flow = !diffs;
409 }
410}
411
412static inline void skb_gro_reset_offset(struct sk_buff *skb, u32 nhoff)
413{
414 const struct skb_shared_info *pinfo = skb_shinfo(skb);
415 const skb_frag_t *frag0 = &pinfo->frags[0];
416
417 NAPI_GRO_CB(skb)->data_offset = 0;
418 NAPI_GRO_CB(skb)->frag0 = NULL;
419 NAPI_GRO_CB(skb)->frag0_len = 0;
420
421 if (!skb_headlen(skb) && pinfo->nr_frags &&
422 !PageHighMem(skb_frag_page(frag0)) &&
423 (!NET_IP_ALIGN || !((skb_frag_off(frag0) + nhoff) & 3))) {
424 NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0);
425 NAPI_GRO_CB(skb)->frag0_len = min_t(unsigned int,
426 skb_frag_size(frag0),
427 skb->end - skb->tail);
428 }
429}
430
431static void gro_pull_from_frag0(struct sk_buff *skb, int grow)
432{
433 struct skb_shared_info *pinfo = skb_shinfo(skb);
434
435 BUG_ON(skb->end - skb->tail < grow);
436
437 memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
438
439 skb->data_len -= grow;
440 skb->tail += grow;
441
442 skb_frag_off_add(&pinfo->frags[0], grow);
443 skb_frag_size_sub(&pinfo->frags[0], grow);
444
445 if (unlikely(!skb_frag_size(&pinfo->frags[0]))) {
446 skb_frag_unref(skb, 0);
447 memmove(pinfo->frags, pinfo->frags + 1,
448 --pinfo->nr_frags * sizeof(pinfo->frags[0]));
449 }
450}
451
452static void gro_flush_oldest(struct napi_struct *napi, struct list_head *head)
453{
454 struct sk_buff *oldest;
455
456 oldest = list_last_entry(head, struct sk_buff, list);
457
458 /* We are called with head length >= MAX_GRO_SKBS, so this is
459 * impossible.
460 */
461 if (WARN_ON_ONCE(!oldest))
462 return;
463
464 /* Do not adjust napi->gro_hash[].count, caller is adding a new
465 * SKB to the chain.
466 */
467 skb_list_del_init(oldest);
468 napi_gro_complete(napi, oldest);
469}
470
471static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
472{
473 u32 bucket = skb_get_hash_raw(skb) & (GRO_HASH_BUCKETS - 1);
474 struct gro_list *gro_list = &napi->gro_hash[bucket];
475 struct list_head *head = &offload_base;
476 struct packet_offload *ptype;
477 __be16 type = skb->protocol;
478 struct sk_buff *pp = NULL;
479 enum gro_result ret;
480 int same_flow;
481 int grow;
482
483 if (netif_elide_gro(skb->dev))
484 goto normal;
485
486 gro_list_prepare(&gro_list->list, skb);
487
488 rcu_read_lock();
489 list_for_each_entry_rcu(ptype, head, list) {
490 if (ptype->type != type || !ptype->callbacks.gro_receive)
491 continue;
492
493 skb_set_network_header(skb, skb_gro_offset(skb));
494 skb_reset_mac_len(skb);
de5a1f3c
PA		 495 BUILD_BUG_ON(sizeof_field(struct napi_gro_cb, zeroed) != sizeof(u32));
496 BUILD_BUG_ON(!IS_ALIGNED(offsetof(struct napi_gro_cb, zeroed),
497 sizeof(u32))); /* Avoid slow unaligned acc */
498 *(u32 *)&NAPI_GRO_CB(skb)->zeroed = 0;
587652bb 499 NAPI_GRO_CB(skb)->flush = skb_is_gso(skb) || skb_has_frag_list(skb);
587652bb 500 NAPI_GRO_CB(skb)->is_atomic = 1;
587652bb
ED		 501
502 /* Setup for GRO checksum validation */
503 switch (skb->ip_summed) {
504 case CHECKSUM_COMPLETE:
505 NAPI_GRO_CB(skb)->csum = skb->csum;
506 NAPI_GRO_CB(skb)->csum_valid = 1;
587652bb
ED		 507 break;
508 case CHECKSUM_UNNECESSARY:
509 NAPI_GRO_CB(skb)->csum_cnt = skb->csum_level + 1;
587652bb 510 break;
587652bb
ED		 511 }
512
513 pp = INDIRECT_CALL_INET(ptype->callbacks.gro_receive,
514 ipv6_gro_receive, inet_gro_receive,
515 &gro_list->list, skb);
516 break;
517 }
518 rcu_read_unlock();
519
520 if (&ptype->list == head)
521 goto normal;
522
523 if (PTR_ERR(pp) == -EINPROGRESS) {
524 ret = GRO_CONSUMED;
525 goto ok;
526 }
527
528 same_flow = NAPI_GRO_CB(skb)->same_flow;
529 ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
530
531 if (pp) {
532 skb_list_del_init(pp);
533 napi_gro_complete(napi, pp);
534 gro_list->count--;
535 }
536
537 if (same_flow)
538 goto ok;
539
540 if (NAPI_GRO_CB(skb)->flush)
541 goto normal;
542
543 if (unlikely(gro_list->count >= MAX_GRO_SKBS))
544 gro_flush_oldest(napi, &gro_list->list);
545 else
546 gro_list->count++;
547
548 NAPI_GRO_CB(skb)->count = 1;
549 NAPI_GRO_CB(skb)->age = jiffies;
550 NAPI_GRO_CB(skb)->last = skb;
551 skb_shinfo(skb)->gso_size = skb_gro_len(skb);
552 list_add(&skb->list, &gro_list->list);
553 ret = GRO_HELD;
554
555pull:
556 grow = skb_gro_offset(skb) - skb_headlen(skb);
557 if (grow > 0)
558 gro_pull_from_frag0(skb, grow);
559ok:
560 if (gro_list->count) {
561 if (!test_bit(bucket, &napi->gro_bitmask))
562 __set_bit(bucket, &napi->gro_bitmask);
563 } else if (test_bit(bucket, &napi->gro_bitmask)) {
564 __clear_bit(bucket, &napi->gro_bitmask);
565 }
566
567 return ret;
568
569normal:
570 ret = GRO_NORMAL;
571 goto pull;
572}
573
574struct packet_offload *gro_find_receive_by_type(__be16 type)
575{
576 struct list_head *offload_head = &offload_base;
577 struct packet_offload *ptype;
578
579 list_for_each_entry_rcu(ptype, offload_head, list) {
580 if (ptype->type != type || !ptype->callbacks.gro_receive)
581 continue;
582 return ptype;
583 }
584 return NULL;
585}
586EXPORT_SYMBOL(gro_find_receive_by_type);
587
588struct packet_offload *gro_find_complete_by_type(__be16 type)
589{
590 struct list_head *offload_head = &offload_base;
591 struct packet_offload *ptype;
592
593 list_for_each_entry_rcu(ptype, offload_head, list) {
594 if (ptype->type != type || !ptype->callbacks.gro_complete)
595 continue;
596 return ptype;
597 }
598 return NULL;
599}
600EXPORT_SYMBOL(gro_find_complete_by_type);
601
602static gro_result_t napi_skb_finish(struct napi_struct *napi,
603 struct sk_buff *skb,
604 gro_result_t ret)
605{
606 switch (ret) {
607 case GRO_NORMAL:
608 gro_normal_one(napi, skb, 1);
609 break;
610
611 case GRO_MERGED_FREE:
612 if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
613 napi_skb_free_stolen_head(skb);
614 else if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
615 __kfree_skb(skb);
616 else
617 __kfree_skb_defer(skb);
618 break;
619
620 case GRO_HELD:
621 case GRO_MERGED:
622 case GRO_CONSUMED:
623 break;
624 }
625
626 return ret;
627}
628
629gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
630{
631 gro_result_t ret;
632
633 skb_mark_napi_id(skb, napi);
634 trace_napi_gro_receive_entry(skb);
635
636 skb_gro_reset_offset(skb, 0);
637
638 ret = napi_skb_finish(napi, skb, dev_gro_receive(napi, skb));
639 trace_napi_gro_receive_exit(ret);
640
641 return ret;
642}
643EXPORT_SYMBOL(napi_gro_receive);
644
645static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
646{
647 if (unlikely(skb->pfmemalloc)) {
648 consume_skb(skb);
649 return;
650 }
651 __skb_pull(skb, skb_headlen(skb));
652 /* restore the reserve we had after netdev_alloc_skb_ip_align() */
653 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
654 __vlan_hwaccel_clear_tag(skb);
655 skb->dev = napi->dev;
656 skb->skb_iif = 0;
657
658 /* eth_type_trans() assumes pkt_type is PACKET_HOST */
659 skb->pkt_type = PACKET_HOST;
660
661 skb->encapsulation = 0;
662 skb_shinfo(skb)->gso_type = 0;
587652bb
ED		 663 if (unlikely(skb->slow_gro)) {
664 skb_orphan(skb);
665 skb_ext_reset(skb);
666 nf_reset_ct(skb);
667 skb->slow_gro = 0;
668 }
669
670 napi->skb = skb;
671}
672
673struct sk_buff *napi_get_frags(struct napi_struct *napi)
674{
675 struct sk_buff *skb = napi->skb;
676
677 if (!skb) {
678 skb = napi_alloc_skb(napi, GRO_MAX_HEAD);
679 if (skb) {
680 napi->skb = skb;
681 skb_mark_napi_id(skb, napi);
682 }
683 }
684 return skb;
685}
686EXPORT_SYMBOL(napi_get_frags);
687
688static gro_result_t napi_frags_finish(struct napi_struct *napi,
689 struct sk_buff *skb,
690 gro_result_t ret)
691{
692 switch (ret) {
693 case GRO_NORMAL:
694 case GRO_HELD:
695 __skb_push(skb, ETH_HLEN);
696 skb->protocol = eth_type_trans(skb, skb->dev);
697 if (ret == GRO_NORMAL)
698 gro_normal_one(napi, skb, 1);
699 break;
700
701 case GRO_MERGED_FREE:
702 if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
703 napi_skb_free_stolen_head(skb);
704 else
705 napi_reuse_skb(napi, skb);
706 break;
707
708 case GRO_MERGED:
709 case GRO_CONSUMED:
710 break;
711 }
712
713 return ret;
714}
715
716/* Upper GRO stack assumes network header starts at gro_offset=0
717 * Drivers could call both napi_gro_frags() and napi_gro_receive()
718 * We copy ethernet header into skb->data to have a common layout.
719 */
720static struct sk_buff *napi_frags_skb(struct napi_struct *napi)
721{
722 struct sk_buff *skb = napi->skb;
723 const struct ethhdr *eth;
724 unsigned int hlen = sizeof(*eth);
725
726 napi->skb = NULL;
727
728 skb_reset_mac_header(skb);
729 skb_gro_reset_offset(skb, hlen);
730
731 if (unlikely(skb_gro_header_hard(skb, hlen))) {
732 eth = skb_gro_header_slow(skb, hlen, 0);
733 if (unlikely(!eth)) {
734 net_warn_ratelimited("%s: dropping impossible skb from %s\n",
735 __func__, napi->dev->name);
736 napi_reuse_skb(napi, skb);
737 return NULL;
738 }
739 } else {
740 eth = (const struct ethhdr *)skb->data;
741 gro_pull_from_frag0(skb, hlen);
742 NAPI_GRO_CB(skb)->frag0 += hlen;
743 NAPI_GRO_CB(skb)->frag0_len -= hlen;
744 }
745 __skb_pull(skb, hlen);
746
747 /*
748 * This works because the only protocols we care about don't require
749 * special handling.
750 * We'll fix it up properly in napi_frags_finish()
751 */
752 skb->protocol = eth->h_proto;
753
754 return skb;
755}
756
757gro_result_t napi_gro_frags(struct napi_struct *napi)
758{
759 gro_result_t ret;
760 struct sk_buff *skb = napi_frags_skb(napi);
761
762 trace_napi_gro_frags_entry(skb);
763
764 ret = napi_frags_finish(napi, skb, dev_gro_receive(napi, skb));
765 trace_napi_gro_frags_exit(ret);
766
767 return ret;
768}
769EXPORT_SYMBOL(napi_gro_frags);
770
771/* Compute the checksum from gro_offset and return the folded value
772 * after adding in any pseudo checksum.
773 */
774__sum16 __skb_gro_checksum_complete(struct sk_buff *skb)
775{
776 __wsum wsum;
777 __sum16 sum;
778
779 wsum = skb_checksum(skb, skb_gro_offset(skb), skb_gro_len(skb), 0);
780
781 /* NAPI_GRO_CB(skb)->csum holds pseudo checksum */
782 sum = csum_fold(csum_add(NAPI_GRO_CB(skb)->csum, wsum));
783 /* See comments in __skb_checksum_complete(). */
784 if (likely(!sum)) {
785 if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
786 !skb->csum_complete_sw)
787 netdev_rx_csum_fault(skb->dev, skb);
788 }
789
790 NAPI_GRO_CB(skb)->csum = wsum;
791 NAPI_GRO_CB(skb)->csum_valid = 1;
792
793 return sum;
794}
795EXPORT_SYMBOL(__skb_gro_checksum_complete);
Linux 6.x block layer and io_uring tree(s)