1 // SPDX-License-Identifier: GPL-2.0-or-later
2 #include <net/psp.h>
3 #include <net/gro.h>
4 #include <net/dst_metadata.h>
5 #include <net/busy_poll.h>
6 #include <trace/events/net.h>
7 #include <linux/skbuff_ref.h>
8
9 #define MAX_GRO_SKBS 8
10
11 static DEFINE_SPINLOCK(offload_lock);
12
13 /**
14 * dev_add_offload - register offload handlers
15 * @po: protocol offload declaration
16 *
17 * Add protocol offload handlers to the networking stack. The passed
18 * &proto_offload is linked into kernel lists and may not be freed until
19 * it has been removed from the kernel lists.
20 *
21 * This call does not sleep therefore it can not
22 * guarantee all CPU's that are in middle of receiving packets
23 * will see the new offload handlers (until the next received packet).
24 */
dev_add_offload(struct packet_offload * po)25 void dev_add_offload(struct packet_offload *po)
26 {
27 struct packet_offload *elem;
28
29 spin_lock(&offload_lock);
30 list_for_each_entry(elem, &net_hotdata.offload_base, list) {
31 if (po->priority < elem->priority)
32 break;
33 }
34 list_add_rcu(&po->list, elem->list.prev);
35 spin_unlock(&offload_lock);
36 }
37 EXPORT_SYMBOL(dev_add_offload);
38
39 /**
40 * __dev_remove_offload - remove offload handler
41 * @po: packet offload declaration
42 *
43 * Remove a protocol offload handler that was previously added to the
44 * kernel offload handlers by dev_add_offload(). The passed &offload_type
45 * is removed from the kernel lists and can be freed or reused once this
46 * function returns.
47 *
48 * The packet type might still be in use by receivers
49 * and must not be freed until after all the CPU's have gone
50 * through a quiescent state.
51 */
__dev_remove_offload(struct packet_offload * po)52 static void __dev_remove_offload(struct packet_offload *po)
53 {
54 struct list_head *head = &net_hotdata.offload_base;
55 struct packet_offload *po1;
56
57 spin_lock(&offload_lock);
58
59 list_for_each_entry(po1, head, list) {
60 if (po == po1) {
61 list_del_rcu(&po->list);
62 goto out;
63 }
64 }
65
66 pr_warn("dev_remove_offload: %p not found\n", po);
67 out:
68 spin_unlock(&offload_lock);
69 }
70
71 /**
72 * dev_remove_offload - remove packet offload handler
73 * @po: packet offload declaration
74 *
75 * Remove a packet offload handler that was previously added to the kernel
76 * offload handlers by dev_add_offload(). The passed &offload_type is
77 * removed from the kernel lists and can be freed or reused once this
78 * function returns.
79 *
80 * This call sleeps to guarantee that no CPU is looking at the packet
81 * type after return.
82 */
dev_remove_offload(struct packet_offload * po)83 void dev_remove_offload(struct packet_offload *po)
84 {
85 __dev_remove_offload(po);
86
87 synchronize_net();
88 }
89 EXPORT_SYMBOL(dev_remove_offload);
90
91
skb_gro_receive(struct sk_buff * p,struct sk_buff * skb)92 int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb)
93 {
94 struct skb_shared_info *pinfo, *skbinfo = skb_shinfo(skb);
95 unsigned int offset = skb_gro_offset(skb);
96 unsigned int headlen = skb_headlen(skb);
97 unsigned int len = skb_gro_len(skb);
98 unsigned int delta_truesize;
99 unsigned int new_truesize;
100 struct sk_buff *lp;
101 int segs;
102
103 /* Do not splice page pool based packets w/ non-page pool
104 * packets. This can result in reference count issues as page
105 * pool pages will not decrement the reference count and will
106 * instead be immediately returned to the pool or have frag
107 * count decremented.
108 */
109 if (p->pp_recycle != skb->pp_recycle)
110 return -ETOOMANYREFS;
111
112 if (unlikely(p->len + len >= netif_get_gro_max_size(p->dev, p) ||
113 NAPI_GRO_CB(skb)->flush))
114 return -E2BIG;
115
116 if (unlikely(p->len + len >= GRO_LEGACY_MAX_SIZE)) {
117 if (NAPI_GRO_CB(skb)->proto != IPPROTO_TCP ||
118 (p->protocol == htons(ETH_P_IPV6) &&
119 skb_headroom(p) < sizeof(struct hop_jumbo_hdr)) ||
120 p->encapsulation)
121 return -E2BIG;
122 }
123
124 segs = NAPI_GRO_CB(skb)->count;
125 lp = NAPI_GRO_CB(p)->last;
126 pinfo = skb_shinfo(lp);
127
128 if (headlen <= offset) {
129 skb_frag_t *frag;
130 skb_frag_t *frag2;
131 int i = skbinfo->nr_frags;
132 int nr_frags = pinfo->nr_frags + i;
133
134 if (nr_frags > MAX_SKB_FRAGS)
135 goto merge;
136
137 offset -= headlen;
138 pinfo->nr_frags = nr_frags;
139 skbinfo->nr_frags = 0;
140
141 frag = pinfo->frags + nr_frags;
142 frag2 = skbinfo->frags + i;
143 do {
144 *--frag = *--frag2;
145 } while (--i);
146
147 skb_frag_off_add(frag, offset);
148 skb_frag_size_sub(frag, offset);
149
150 /* all fragments truesize : remove (head size + sk_buff) */
151 new_truesize = SKB_TRUESIZE(skb_end_offset(skb));
152 delta_truesize = skb->truesize - new_truesize;
153
154 skb->truesize = new_truesize;
155 skb->len -= skb->data_len;
156 skb->data_len = 0;
157
158 NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE;
159 goto done;
160 } else if (skb->head_frag) {
161 int nr_frags = pinfo->nr_frags;
162 skb_frag_t *frag = pinfo->frags + nr_frags;
163 struct page *page = virt_to_head_page(skb->head);
164 unsigned int first_size = headlen - offset;
165 unsigned int first_offset;
166
167 if (nr_frags + 1 + skbinfo->nr_frags > MAX_SKB_FRAGS)
168 goto merge;
169
170 first_offset = skb->data -
171 (unsigned char *)page_address(page) +
172 offset;
173
174 pinfo->nr_frags = nr_frags + 1 + skbinfo->nr_frags;
175
176 skb_frag_fill_page_desc(frag, page, first_offset, first_size);
177
178 memcpy(frag + 1, skbinfo->frags, sizeof(*frag) * skbinfo->nr_frags);
179 /* We dont need to clear skbinfo->nr_frags here */
180
181 new_truesize = SKB_DATA_ALIGN(sizeof(struct sk_buff));
182 delta_truesize = skb->truesize - new_truesize;
183 skb->truesize = new_truesize;
184 NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD;
185 goto done;
186 }
187
188 merge:
189 /* sk ownership - if any - completely transferred to the aggregated packet */
190 skb->destructor = NULL;
191 skb->sk = NULL;
192 delta_truesize = skb->truesize;
193 if (offset > headlen) {
194 unsigned int eat = offset - headlen;
195
196 skb_frag_off_add(&skbinfo->frags[0], eat);
197 skb_frag_size_sub(&skbinfo->frags[0], eat);
198 skb->data_len -= eat;
199 skb->len -= eat;
200 offset = headlen;
201 }
202
203 __skb_pull(skb, offset);
204
205 if (NAPI_GRO_CB(p)->last == p)
206 skb_shinfo(p)->frag_list = skb;
207 else
208 NAPI_GRO_CB(p)->last->next = skb;
209 NAPI_GRO_CB(p)->last = skb;
210 __skb_header_release(skb);
211 lp = p;
212
213 done:
214 NAPI_GRO_CB(p)->count += segs;
215 p->data_len += len;
216 p->truesize += delta_truesize;
217 p->len += len;
218 if (lp != p) {
219 lp->data_len += len;
220 lp->truesize += delta_truesize;
221 lp->len += len;
222 }
223 NAPI_GRO_CB(skb)->same_flow = 1;
224 return 0;
225 }
226
skb_gro_receive_list(struct sk_buff * p,struct sk_buff * skb)227 int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb)
228 {
229 if (unlikely(p->len + skb->len >= 65536))
230 return -E2BIG;
231
232 if (NAPI_GRO_CB(p)->last == p)
233 skb_shinfo(p)->frag_list = skb;
234 else
235 NAPI_GRO_CB(p)->last->next = skb;
236
237 skb_pull(skb, skb_gro_offset(skb));
238
239 NAPI_GRO_CB(p)->last = skb;
240 NAPI_GRO_CB(p)->count++;
241 p->data_len += skb->len;
242
243 /* sk ownership - if any - completely transferred to the aggregated packet */
244 skb->destructor = NULL;
245 skb->sk = NULL;
246 p->truesize += skb->truesize;
247 p->len += skb->len;
248
249 NAPI_GRO_CB(skb)->same_flow = 1;
250
251 return 0;
252 }
253
gro_complete(struct gro_node * gro,struct sk_buff * skb)254 static void gro_complete(struct gro_node *gro, struct sk_buff *skb)
255 {
256 struct list_head *head = &net_hotdata.offload_base;
257 struct packet_offload *ptype;
258 __be16 type = skb->protocol;
259 int err = -ENOENT;
260
261 BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb));
262
263 if (NAPI_GRO_CB(skb)->count == 1) {
264 skb_shinfo(skb)->gso_size = 0;
265 goto out;
266 }
267
268 rcu_read_lock();
269 list_for_each_entry_rcu(ptype, head, list) {
270 if (ptype->type != type || !ptype->callbacks.gro_complete)
271 continue;
272
273 err = INDIRECT_CALL_INET(ptype->callbacks.gro_complete,
274 ipv6_gro_complete, inet_gro_complete,
275 skb, 0);
276 break;
277 }
278 rcu_read_unlock();
279
280 if (err) {
281 WARN_ON(&ptype->list == head);
282 kfree_skb(skb);
283 return;
284 }
285
286 out:
287 gro_normal_one(gro, skb, NAPI_GRO_CB(skb)->count);
288 }
289
__gro_flush_chain(struct gro_node * gro,u32 index,bool flush_old)290 static void __gro_flush_chain(struct gro_node *gro, u32 index, bool flush_old)
291 {
292 struct list_head *head = &gro->hash[index].list;
293 struct sk_buff *skb, *p;
294
295 list_for_each_entry_safe_reverse(skb, p, head, list) {
296 if (flush_old && NAPI_GRO_CB(skb)->age == jiffies)
297 return;
298 skb_list_del_init(skb);
299 gro_complete(gro, skb);
300 gro->hash[index].count--;
301 }
302
303 if (!gro->hash[index].count)
304 __clear_bit(index, &gro->bitmask);
305 }
306
307 /*
308 * gro->hash[].list contains packets ordered by age.
309 * youngest packets at the head of it.
310 * Complete skbs in reverse order to reduce latencies.
311 */
__gro_flush(struct gro_node * gro,bool flush_old)312 void __gro_flush(struct gro_node *gro, bool flush_old)
313 {
314 unsigned long bitmask = gro->bitmask;
315 unsigned int i, base = ~0U;
316
317 while ((i = ffs(bitmask)) != 0) {
318 bitmask >>= i;
319 base += i;
320 __gro_flush_chain(gro, base, flush_old);
321 }
322 }
323 EXPORT_SYMBOL(__gro_flush);
324
gro_list_prepare_tc_ext(const struct sk_buff * skb,const struct sk_buff * p,unsigned long diffs)325 static unsigned long gro_list_prepare_tc_ext(const struct sk_buff *skb,
326 const struct sk_buff *p,
327 unsigned long diffs)
328 {
329 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
330 struct tc_skb_ext *skb_ext;
331 struct tc_skb_ext *p_ext;
332
333 skb_ext = skb_ext_find(skb, TC_SKB_EXT);
334 p_ext = skb_ext_find(p, TC_SKB_EXT);
335
336 diffs |= (!!p_ext) ^ (!!skb_ext);
337 if (!diffs && unlikely(skb_ext))
338 diffs |= p_ext->chain ^ skb_ext->chain;
339 #endif
340 return diffs;
341 }
342
gro_list_prepare(const struct list_head * head,const struct sk_buff * skb)343 static void gro_list_prepare(const struct list_head *head,
344 const struct sk_buff *skb)
345 {
346 unsigned int maclen = skb->dev->hard_header_len;
347 u32 hash = skb_get_hash_raw(skb);
348 struct sk_buff *p;
349
350 list_for_each_entry(p, head, list) {
351 unsigned long diffs;
352
353 if (hash != skb_get_hash_raw(p)) {
354 NAPI_GRO_CB(p)->same_flow = 0;
355 continue;
356 }
357
358 diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
359 diffs |= p->vlan_all ^ skb->vlan_all;
360 diffs |= skb_metadata_differs(p, skb);
361 if (maclen == ETH_HLEN)
362 diffs |= compare_ether_header(skb_mac_header(p),
363 skb_mac_header(skb));
364 else if (!diffs)
365 diffs = memcmp(skb_mac_header(p),
366 skb_mac_header(skb),
367 maclen);
368
369 /* in most common scenarios 'slow_gro' is 0
370 * otherwise we are already on some slower paths
371 * either skip all the infrequent tests altogether or
372 * avoid trying too hard to skip each of them individually
373 */
374 if (!diffs && unlikely(skb->slow_gro | p->slow_gro)) {
375 diffs |= p->sk != skb->sk;
376 diffs |= skb_metadata_dst_cmp(p, skb);
377 diffs |= skb_get_nfct(p) ^ skb_get_nfct(skb);
378
379 diffs |= gro_list_prepare_tc_ext(skb, p, diffs);
380 diffs |= __psp_skb_coalesce_diff(skb, p, diffs);
381 }
382
383 NAPI_GRO_CB(p)->same_flow = !diffs;
384 }
385 }
386
skb_gro_reset_offset(struct sk_buff * skb,u32 nhoff)387 static inline void skb_gro_reset_offset(struct sk_buff *skb, u32 nhoff)
388 {
389 const struct skb_shared_info *pinfo;
390 const skb_frag_t *frag0;
391 unsigned int headlen;
392
393 NAPI_GRO_CB(skb)->network_offset = 0;
394 NAPI_GRO_CB(skb)->data_offset = 0;
395 headlen = skb_headlen(skb);
396 NAPI_GRO_CB(skb)->frag0 = skb->data;
397 NAPI_GRO_CB(skb)->frag0_len = headlen;
398 if (headlen)
399 return;
400
401 pinfo = skb_shinfo(skb);
402 frag0 = &pinfo->frags[0];
403
404 if (pinfo->nr_frags && skb_frag_page(frag0) &&
405 !PageHighMem(skb_frag_page(frag0)) &&
406 (!NET_IP_ALIGN || !((skb_frag_off(frag0) + nhoff) & 3))) {
407 NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0);
408 NAPI_GRO_CB(skb)->frag0_len = min_t(unsigned int,
409 skb_frag_size(frag0),
410 skb->end - skb->tail);
411 }
412 }
413
gro_pull_from_frag0(struct sk_buff * skb,int grow)414 static void gro_pull_from_frag0(struct sk_buff *skb, int grow)
415 {
416 struct skb_shared_info *pinfo = skb_shinfo(skb);
417
418 BUG_ON(skb->end - skb->tail < grow);
419
420 memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
421
422 skb->data_len -= grow;
423 skb->tail += grow;
424
425 skb_frag_off_add(&pinfo->frags[0], grow);
426 skb_frag_size_sub(&pinfo->frags[0], grow);
427
428 if (unlikely(!skb_frag_size(&pinfo->frags[0]))) {
429 skb_frag_unref(skb, 0);
430 memmove(pinfo->frags, pinfo->frags + 1,
431 --pinfo->nr_frags * sizeof(pinfo->frags[0]));
432 }
433 }
434
gro_try_pull_from_frag0(struct sk_buff * skb)435 static void gro_try_pull_from_frag0(struct sk_buff *skb)
436 {
437 int grow = skb_gro_offset(skb) - skb_headlen(skb);
438
439 if (grow > 0)
440 gro_pull_from_frag0(skb, grow);
441 }
442
gro_flush_oldest(struct gro_node * gro,struct list_head * head)443 static void gro_flush_oldest(struct gro_node *gro, struct list_head *head)
444 {
445 struct sk_buff *oldest;
446
447 oldest = list_last_entry(head, struct sk_buff, list);
448
449 /* We are called with head length >= MAX_GRO_SKBS, so this is
450 * impossible.
451 */
452 if (WARN_ON_ONCE(!oldest))
453 return;
454
455 /* Do not adjust napi->gro_hash[].count, caller is adding a new
456 * SKB to the chain.
457 */
458 skb_list_del_init(oldest);
459 gro_complete(gro, oldest);
460 }
461
dev_gro_receive(struct gro_node * gro,struct sk_buff * skb)462 static enum gro_result dev_gro_receive(struct gro_node *gro,
463 struct sk_buff *skb)
464 {
465 u32 bucket = skb_get_hash_raw(skb) & (GRO_HASH_BUCKETS - 1);
466 struct list_head *head = &net_hotdata.offload_base;
467 struct gro_list *gro_list = &gro->hash[bucket];
468 struct packet_offload *ptype;
469 __be16 type = skb->protocol;
470 struct sk_buff *pp = NULL;
471 enum gro_result ret;
472 int same_flow;
473
474 if (netif_elide_gro(skb->dev))
475 goto normal;
476
477 gro_list_prepare(&gro_list->list, skb);
478
479 rcu_read_lock();
480 list_for_each_entry_rcu(ptype, head, list) {
481 if (ptype->type == type && ptype->callbacks.gro_receive)
482 goto found_ptype;
483 }
484 rcu_read_unlock();
485 goto normal;
486
487 found_ptype:
488 skb_set_network_header(skb, skb_gro_offset(skb));
489 skb_reset_mac_len(skb);
490 BUILD_BUG_ON(sizeof_field(struct napi_gro_cb, zeroed) != sizeof(u32));
491 BUILD_BUG_ON(!IS_ALIGNED(offsetof(struct napi_gro_cb, zeroed),
492 sizeof(u32))); /* Avoid slow unaligned acc */
493 *(u32 *)&NAPI_GRO_CB(skb)->zeroed = 0;
494 NAPI_GRO_CB(skb)->flush = skb_has_frag_list(skb);
495 NAPI_GRO_CB(skb)->count = 1;
496 if (unlikely(skb_is_gso(skb))) {
497 NAPI_GRO_CB(skb)->count = skb_shinfo(skb)->gso_segs;
498 /* Only support TCP and non DODGY users. */
499 if (!skb_is_gso_tcp(skb) ||
500 (skb_shinfo(skb)->gso_type & SKB_GSO_DODGY))
501 NAPI_GRO_CB(skb)->flush = 1;
502 }
503
504 /* Setup for GRO checksum validation */
505 switch (skb->ip_summed) {
506 case CHECKSUM_COMPLETE:
507 NAPI_GRO_CB(skb)->csum = skb->csum;
508 NAPI_GRO_CB(skb)->csum_valid = 1;
509 break;
510 case CHECKSUM_UNNECESSARY:
511 NAPI_GRO_CB(skb)->csum_cnt = skb->csum_level + 1;
512 break;
513 }
514
515 pp = INDIRECT_CALL_INET(ptype->callbacks.gro_receive,
516 ipv6_gro_receive, inet_gro_receive,
517 &gro_list->list, skb);
518
519 rcu_read_unlock();
520
521 if (PTR_ERR(pp) == -EINPROGRESS) {
522 ret = GRO_CONSUMED;
523 goto ok;
524 }
525
526 same_flow = NAPI_GRO_CB(skb)->same_flow;
527 ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
528
529 if (pp) {
530 skb_list_del_init(pp);
531 gro_complete(gro, pp);
532 gro_list->count--;
533 }
534
535 if (same_flow)
536 goto ok;
537
538 if (NAPI_GRO_CB(skb)->flush)
539 goto normal;
540
541 if (unlikely(gro_list->count >= MAX_GRO_SKBS))
542 gro_flush_oldest(gro, &gro_list->list);
543 else
544 gro_list->count++;
545
546 /* Must be called before setting NAPI_GRO_CB(skb)->{age|last} */
547 gro_try_pull_from_frag0(skb);
548 NAPI_GRO_CB(skb)->age = jiffies;
549 NAPI_GRO_CB(skb)->last = skb;
550 if (!skb_is_gso(skb))
551 skb_shinfo(skb)->gso_size = skb_gro_len(skb);
552 list_add(&skb->list, &gro_list->list);
553 ret = GRO_HELD;
554 ok:
555 if (gro_list->count) {
556 if (!test_bit(bucket, &gro->bitmask))
557 __set_bit(bucket, &gro->bitmask);
558 } else if (test_bit(bucket, &gro->bitmask)) {
559 __clear_bit(bucket, &gro->bitmask);
560 }
561
562 return ret;
563
564 normal:
565 ret = GRO_NORMAL;
566 gro_try_pull_from_frag0(skb);
567 goto ok;
568 }
569
gro_find_receive_by_type(__be16 type)570 struct packet_offload *gro_find_receive_by_type(__be16 type)
571 {
572 struct list_head *offload_head = &net_hotdata.offload_base;
573 struct packet_offload *ptype;
574
575 list_for_each_entry_rcu(ptype, offload_head, list) {
576 if (ptype->type != type || !ptype->callbacks.gro_receive)
577 continue;
578 return ptype;
579 }
580 return NULL;
581 }
582 EXPORT_SYMBOL(gro_find_receive_by_type);
583
gro_find_complete_by_type(__be16 type)584 struct packet_offload *gro_find_complete_by_type(__be16 type)
585 {
586 struct list_head *offload_head = &net_hotdata.offload_base;
587 struct packet_offload *ptype;
588
589 list_for_each_entry_rcu(ptype, offload_head, list) {
590 if (ptype->type != type || !ptype->callbacks.gro_complete)
591 continue;
592 return ptype;
593 }
594 return NULL;
595 }
596 EXPORT_SYMBOL(gro_find_complete_by_type);
597
gro_skb_finish(struct gro_node * gro,struct sk_buff * skb,gro_result_t ret)598 static gro_result_t gro_skb_finish(struct gro_node *gro, struct sk_buff *skb,
599 gro_result_t ret)
600 {
601 switch (ret) {
602 case GRO_NORMAL:
603 gro_normal_one(gro, skb, 1);
604 break;
605
606 case GRO_MERGED_FREE:
607 if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
608 napi_skb_free_stolen_head(skb);
609 else if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
610 __kfree_skb(skb);
611 else
612 __napi_kfree_skb(skb, SKB_CONSUMED);
613 break;
614
615 case GRO_HELD:
616 case GRO_MERGED:
617 case GRO_CONSUMED:
618 break;
619 }
620
621 return ret;
622 }
623
gro_receive_skb(struct gro_node * gro,struct sk_buff * skb)624 gro_result_t gro_receive_skb(struct gro_node *gro, struct sk_buff *skb)
625 {
626 gro_result_t ret;
627
628 __skb_mark_napi_id(skb, gro);
629 trace_napi_gro_receive_entry(skb);
630
631 skb_gro_reset_offset(skb, 0);
632
633 ret = gro_skb_finish(gro, skb, dev_gro_receive(gro, skb));
634 trace_napi_gro_receive_exit(ret);
635
636 return ret;
637 }
638 EXPORT_SYMBOL(gro_receive_skb);
639
napi_reuse_skb(struct napi_struct * napi,struct sk_buff * skb)640 static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
641 {
642 struct skb_shared_info *shinfo;
643
644 if (unlikely(skb->pfmemalloc)) {
645 consume_skb(skb);
646 return;
647 }
648 __skb_pull(skb, skb_headlen(skb));
649 /* restore the reserve we had after netdev_alloc_skb_ip_align() */
650 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
651 __vlan_hwaccel_clear_tag(skb);
652 skb->dev = napi->dev;
653 skb->skb_iif = 0;
654
655 /* eth_type_trans() assumes pkt_type is PACKET_HOST */
656 skb->pkt_type = PACKET_HOST;
657
658 skb->encapsulation = 0;
659 skb->ip_summed = CHECKSUM_NONE;
660
661 shinfo = skb_shinfo(skb);
662 shinfo->gso_type = 0;
663 shinfo->gso_size = 0;
664 shinfo->hwtstamps.hwtstamp = 0;
665
666 if (unlikely(skb->slow_gro)) {
667 skb_orphan(skb);
668 skb_ext_reset(skb);
669 nf_reset_ct(skb);
670 skb->slow_gro = 0;
671 }
672
673 napi->skb = skb;
674 }
675
napi_get_frags(struct napi_struct * napi)676 struct sk_buff *napi_get_frags(struct napi_struct *napi)
677 {
678 struct sk_buff *skb = napi->skb;
679
680 if (!skb) {
681 skb = napi_alloc_skb(napi, GRO_MAX_HEAD);
682 if (skb) {
683 napi->skb = skb;
684 skb_mark_napi_id(skb, napi);
685 }
686 }
687 return skb;
688 }
689 EXPORT_SYMBOL(napi_get_frags);
690
napi_frags_finish(struct napi_struct * napi,struct sk_buff * skb,gro_result_t ret)691 static gro_result_t napi_frags_finish(struct napi_struct *napi,
692 struct sk_buff *skb,
693 gro_result_t ret)
694 {
695 switch (ret) {
696 case GRO_NORMAL:
697 case GRO_HELD:
698 __skb_push(skb, ETH_HLEN);
699 skb->protocol = eth_type_trans(skb, skb->dev);
700 if (ret == GRO_NORMAL)
701 gro_normal_one(&napi->gro, skb, 1);
702 break;
703
704 case GRO_MERGED_FREE:
705 if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
706 napi_skb_free_stolen_head(skb);
707 else
708 napi_reuse_skb(napi, skb);
709 break;
710
711 case GRO_MERGED:
712 case GRO_CONSUMED:
713 break;
714 }
715
716 return ret;
717 }
718
719 /* Upper GRO stack assumes network header starts at gro_offset=0
720 * Drivers could call both napi_gro_frags() and napi_gro_receive()
721 * We copy ethernet header into skb->data to have a common layout.
722 */
napi_frags_skb(struct napi_struct * napi)723 static struct sk_buff *napi_frags_skb(struct napi_struct *napi)
724 {
725 struct sk_buff *skb = napi->skb;
726 const struct ethhdr *eth;
727 unsigned int hlen = sizeof(*eth);
728
729 napi->skb = NULL;
730
731 skb_reset_mac_header(skb);
732 skb_gro_reset_offset(skb, hlen);
733
734 if (unlikely(!skb_gro_may_pull(skb, hlen))) {
735 eth = skb_gro_header_slow(skb, hlen, 0);
736 if (unlikely(!eth)) {
737 net_warn_ratelimited("%s: dropping impossible skb from %s\n",
738 __func__, napi->dev->name);
739 napi_reuse_skb(napi, skb);
740 return NULL;
741 }
742 } else {
743 eth = (const struct ethhdr *)skb->data;
744
745 if (NAPI_GRO_CB(skb)->frag0 != skb->data)
746 gro_pull_from_frag0(skb, hlen);
747
748 NAPI_GRO_CB(skb)->frag0 += hlen;
749 NAPI_GRO_CB(skb)->frag0_len -= hlen;
750 }
751 __skb_pull(skb, hlen);
752
753 /*
754 * This works because the only protocols we care about don't require
755 * special handling.
756 * We'll fix it up properly in napi_frags_finish()
757 */
758 skb->protocol = eth->h_proto;
759
760 return skb;
761 }
762
napi_gro_frags(struct napi_struct * napi)763 gro_result_t napi_gro_frags(struct napi_struct *napi)
764 {
765 gro_result_t ret;
766 struct sk_buff *skb = napi_frags_skb(napi);
767
768 trace_napi_gro_frags_entry(skb);
769
770 ret = napi_frags_finish(napi, skb, dev_gro_receive(&napi->gro, skb));
771 trace_napi_gro_frags_exit(ret);
772
773 return ret;
774 }
775 EXPORT_SYMBOL(napi_gro_frags);
776
777 /* Compute the checksum from gro_offset and return the folded value
778 * after adding in any pseudo checksum.
779 */
__skb_gro_checksum_complete(struct sk_buff * skb)780 __sum16 __skb_gro_checksum_complete(struct sk_buff *skb)
781 {
782 __wsum wsum;
783 __sum16 sum;
784
785 wsum = skb_checksum(skb, skb_gro_offset(skb), skb_gro_len(skb), 0);
786
787 /* NAPI_GRO_CB(skb)->csum holds pseudo checksum */
788 sum = csum_fold(csum_add(NAPI_GRO_CB(skb)->csum, wsum));
789 /* See comments in __skb_checksum_complete(). */
790 if (likely(!sum)) {
791 if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
792 !skb->csum_complete_sw)
793 netdev_rx_csum_fault(skb->dev, skb);
794 }
795
796 NAPI_GRO_CB(skb)->csum = wsum;
797 NAPI_GRO_CB(skb)->csum_valid = 1;
798
799 return sum;
800 }
801 EXPORT_SYMBOL(__skb_gro_checksum_complete);
802
gro_init(struct gro_node * gro)803 void gro_init(struct gro_node *gro)
804 {
805 for (u32 i = 0; i < GRO_HASH_BUCKETS; i++) {
806 INIT_LIST_HEAD(&gro->hash[i].list);
807 gro->hash[i].count = 0;
808 }
809
810 gro->bitmask = 0;
811 gro->cached_napi_id = 0;
812
813 INIT_LIST_HEAD(&gro->rx_list);
814 gro->rx_count = 0;
815 }
816
gro_cleanup(struct gro_node * gro)817 void gro_cleanup(struct gro_node *gro)
818 {
819 struct sk_buff *skb, *n;
820
821 for (u32 i = 0; i < GRO_HASH_BUCKETS; i++) {
822 list_for_each_entry_safe(skb, n, &gro->hash[i].list, list)
823 kfree_skb(skb);
824
825 gro->hash[i].count = 0;
826 }
827
828 gro->bitmask = 0;
829 gro->cached_napi_id = 0;
830
831 list_for_each_entry_safe(skb, n, &gro->rx_list, list)
832 kfree_skb(skb);
833
834 gro->rx_count = 0;
835 }
836