1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * IPV4 GSO/GRO offload support
4 * Linux INET implementation
5 *
6 * UDPv4 GSO support
7 */
8
9 #include <linux/skbuff.h>
10 #include <net/udp.h>
11 #include <net/protocol.h>
12 #include <net/inet_common.h>
13 #include <net/ip6_checksum.h>
14
__skb_udp_tunnel_segment(struct sk_buff * skb,netdev_features_t features,struct sk_buff * (* gso_inner_segment)(struct sk_buff * skb,netdev_features_t features),__be16 new_protocol,bool is_ipv6)15 static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
16 netdev_features_t features,
17 struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb,
18 netdev_features_t features),
19 __be16 new_protocol, bool is_ipv6)
20 {
21 int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
22 bool remcsum, need_csum, offload_csum, gso_partial;
23 struct sk_buff *segs = ERR_PTR(-EINVAL);
24 struct udphdr *uh = udp_hdr(skb);
25 u16 mac_offset = skb->mac_header;
26 __be16 protocol = skb->protocol;
27 u16 mac_len = skb->mac_len;
28 int udp_offset, outer_hlen;
29 __wsum partial;
30 bool need_ipsec;
31
32 if (unlikely(!pskb_may_pull(skb, tnl_hlen)))
33 goto out;
34
35 /* Adjust partial header checksum to negate old length.
36 * We cannot rely on the value contained in uh->len as it is
37 * possible that the actual value exceeds the boundaries of the
38 * 16 bit length field due to the header being added outside of an
39 * IP or IPv6 frame that was already limited to 64K - 1.
40 */
41 if (skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL)
42 partial = (__force __wsum)uh->len;
43 else
44 partial = (__force __wsum)htonl(skb->len);
45 partial = csum_sub(csum_unfold(uh->check), partial);
46
47 /* setup inner skb. */
48 skb->encapsulation = 0;
49 SKB_GSO_CB(skb)->encap_level = 0;
50 __skb_pull(skb, tnl_hlen);
51 skb_reset_mac_header(skb);
52 skb_set_network_header(skb, skb_inner_network_offset(skb));
53 skb->mac_len = skb_inner_network_offset(skb);
54 skb->protocol = new_protocol;
55
56 need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM);
57 skb->encap_hdr_csum = need_csum;
58
59 remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM);
60 skb->remcsum_offload = remcsum;
61
62 need_ipsec = skb_dst(skb) && dst_xfrm(skb_dst(skb));
63 /* Try to offload checksum if possible */
64 offload_csum = !!(need_csum &&
65 !need_ipsec &&
66 (skb->dev->features &
67 (is_ipv6 ? (NETIF_F_HW_CSUM | NETIF_F_IPV6_CSUM) :
68 (NETIF_F_HW_CSUM | NETIF_F_IP_CSUM))));
69
70 features &= skb->dev->hw_enc_features;
71
72 /* The only checksum offload we care about from here on out is the
73 * outer one so strip the existing checksum feature flags and
74 * instead set the flag based on our outer checksum offload value.
75 */
76 if (remcsum) {
77 features &= ~NETIF_F_CSUM_MASK;
78 if (!need_csum || offload_csum)
79 features |= NETIF_F_HW_CSUM;
80 }
81
82 /* segment inner packet. */
83 segs = gso_inner_segment(skb, features);
84 if (IS_ERR_OR_NULL(segs)) {
85 skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset,
86 mac_len);
87 goto out;
88 }
89
90 gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
91
92 outer_hlen = skb_tnl_header_len(skb);
93 udp_offset = outer_hlen - tnl_hlen;
94 skb = segs;
95 do {
96 unsigned int len;
97
98 if (remcsum)
99 skb->ip_summed = CHECKSUM_NONE;
100
101 /* Set up inner headers if we are offloading inner checksum */
102 if (skb->ip_summed == CHECKSUM_PARTIAL) {
103 skb_reset_inner_headers(skb);
104 skb->encapsulation = 1;
105 }
106
107 skb->mac_len = mac_len;
108 skb->protocol = protocol;
109
110 __skb_push(skb, outer_hlen);
111 skb_reset_mac_header(skb);
112 skb_set_network_header(skb, mac_len);
113 skb_set_transport_header(skb, udp_offset);
114 len = skb->len - udp_offset;
115 uh = udp_hdr(skb);
116
117 /* If we are only performing partial GSO the inner header
118 * will be using a length value equal to only one MSS sized
119 * segment instead of the entire frame.
120 */
121 if (gso_partial && skb_is_gso(skb)) {
122 uh->len = htons(skb_shinfo(skb)->gso_size +
123 SKB_GSO_CB(skb)->data_offset +
124 skb->head - (unsigned char *)uh);
125 } else {
126 uh->len = htons(len);
127 }
128
129 if (!need_csum)
130 continue;
131
132 uh->check = ~csum_fold(csum_add(partial,
133 (__force __wsum)htonl(len)));
134
135 if (skb->encapsulation || !offload_csum) {
136 uh->check = gso_make_checksum(skb, ~uh->check);
137 if (uh->check == 0)
138 uh->check = CSUM_MANGLED_0;
139 } else {
140 skb->ip_summed = CHECKSUM_PARTIAL;
141 skb->csum_start = skb_transport_header(skb) - skb->head;
142 skb->csum_offset = offsetof(struct udphdr, check);
143 }
144 } while ((skb = skb->next));
145 out:
146 return segs;
147 }
148
skb_udp_tunnel_segment(struct sk_buff * skb,netdev_features_t features,bool is_ipv6)149 struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
150 netdev_features_t features,
151 bool is_ipv6)
152 {
153 __be16 protocol = skb->protocol;
154 const struct net_offload **offloads;
155 const struct net_offload *ops;
156 struct sk_buff *segs = ERR_PTR(-EINVAL);
157 struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb,
158 netdev_features_t features);
159
160 rcu_read_lock();
161
162 switch (skb->inner_protocol_type) {
163 case ENCAP_TYPE_ETHER:
164 protocol = skb->inner_protocol;
165 gso_inner_segment = skb_mac_gso_segment;
166 break;
167 case ENCAP_TYPE_IPPROTO:
168 offloads = is_ipv6 ? inet6_offloads : inet_offloads;
169 ops = rcu_dereference(offloads[skb->inner_ipproto]);
170 if (!ops || !ops->callbacks.gso_segment)
171 goto out_unlock;
172 gso_inner_segment = ops->callbacks.gso_segment;
173 break;
174 default:
175 goto out_unlock;
176 }
177
178 segs = __skb_udp_tunnel_segment(skb, features, gso_inner_segment,
179 protocol, is_ipv6);
180
181 out_unlock:
182 rcu_read_unlock();
183
184 return segs;
185 }
186 EXPORT_SYMBOL(skb_udp_tunnel_segment);
187
__udpv4_gso_segment_csum(struct sk_buff * seg,__be32 * oldip,__be32 * newip,__be16 * oldport,__be16 * newport)188 static void __udpv4_gso_segment_csum(struct sk_buff *seg,
189 __be32 *oldip, __be32 *newip,
190 __be16 *oldport, __be16 *newport)
191 {
192 struct udphdr *uh;
193 struct iphdr *iph;
194
195 if (*oldip == *newip && *oldport == *newport)
196 return;
197
198 uh = udp_hdr(seg);
199 iph = ip_hdr(seg);
200
201 if (uh->check) {
202 inet_proto_csum_replace4(&uh->check, seg, *oldip, *newip,
203 true);
204 inet_proto_csum_replace2(&uh->check, seg, *oldport, *newport,
205 false);
206 if (!uh->check)
207 uh->check = CSUM_MANGLED_0;
208 }
209 *oldport = *newport;
210
211 csum_replace4(&iph->check, *oldip, *newip);
212 *oldip = *newip;
213 }
214
__udpv4_gso_segment_list_csum(struct sk_buff * segs)215 static struct sk_buff *__udpv4_gso_segment_list_csum(struct sk_buff *segs)
216 {
217 struct sk_buff *seg;
218 struct udphdr *uh, *uh2;
219 struct iphdr *iph, *iph2;
220
221 seg = segs;
222 uh = udp_hdr(seg);
223 iph = ip_hdr(seg);
224
225 if ((udp_hdr(seg)->dest == udp_hdr(seg->next)->dest) &&
226 (udp_hdr(seg)->source == udp_hdr(seg->next)->source) &&
227 (ip_hdr(seg)->daddr == ip_hdr(seg->next)->daddr) &&
228 (ip_hdr(seg)->saddr == ip_hdr(seg->next)->saddr))
229 return segs;
230
231 while ((seg = seg->next)) {
232 uh2 = udp_hdr(seg);
233 iph2 = ip_hdr(seg);
234
235 __udpv4_gso_segment_csum(seg,
236 &iph2->saddr, &iph->saddr,
237 &uh2->source, &uh->source);
238 __udpv4_gso_segment_csum(seg,
239 &iph2->daddr, &iph->daddr,
240 &uh2->dest, &uh->dest);
241 }
242
243 return segs;
244 }
245
__udp_gso_segment_list(struct sk_buff * skb,netdev_features_t features,bool is_ipv6)246 static struct sk_buff *__udp_gso_segment_list(struct sk_buff *skb,
247 netdev_features_t features,
248 bool is_ipv6)
249 {
250 unsigned int mss = skb_shinfo(skb)->gso_size;
251
252 skb = skb_segment_list(skb, features, skb_mac_header_len(skb));
253 if (IS_ERR(skb))
254 return skb;
255
256 udp_hdr(skb)->len = htons(sizeof(struct udphdr) + mss);
257
258 return is_ipv6 ? skb : __udpv4_gso_segment_list_csum(skb);
259 }
260
__udp_gso_segment(struct sk_buff * gso_skb,netdev_features_t features,bool is_ipv6)261 struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
262 netdev_features_t features, bool is_ipv6)
263 {
264 struct sock *sk = gso_skb->sk;
265 unsigned int sum_truesize = 0;
266 struct sk_buff *segs, *seg;
267 struct udphdr *uh;
268 unsigned int mss;
269 bool copy_dtor;
270 __sum16 check;
271 __be16 newlen;
272 int ret = 0;
273
274 if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST) {
275 /* Detect modified geometry and pass those to skb_segment. */
276 if (skb_pagelen(gso_skb) - sizeof(*uh) == skb_shinfo(gso_skb)->gso_size)
277 return __udp_gso_segment_list(gso_skb, features, is_ipv6);
278
279 ret = __skb_linearize(gso_skb);
280 if (ret)
281 return ERR_PTR(ret);
282
283 /* Setup csum, as fraglist skips this in udp4_gro_receive. */
284 gso_skb->csum_start = skb_transport_header(gso_skb) - gso_skb->head;
285 gso_skb->csum_offset = offsetof(struct udphdr, check);
286 gso_skb->ip_summed = CHECKSUM_PARTIAL;
287
288 uh = udp_hdr(gso_skb);
289 if (is_ipv6)
290 uh->check = ~udp_v6_check(gso_skb->len,
291 &ipv6_hdr(gso_skb)->saddr,
292 &ipv6_hdr(gso_skb)->daddr, 0);
293 else
294 uh->check = ~udp_v4_check(gso_skb->len,
295 ip_hdr(gso_skb)->saddr,
296 ip_hdr(gso_skb)->daddr, 0);
297 }
298
299 mss = skb_shinfo(gso_skb)->gso_size;
300 if (gso_skb->len <= sizeof(*uh) + mss)
301 return ERR_PTR(-EINVAL);
302
303 skb_pull(gso_skb, sizeof(*uh));
304
305 /* clear destructor to avoid skb_segment assigning it to tail */
306 copy_dtor = gso_skb->destructor == sock_wfree;
307 if (copy_dtor) {
308 gso_skb->destructor = NULL;
309 gso_skb->sk = NULL;
310 }
311
312 segs = skb_segment(gso_skb, features);
313 if (IS_ERR_OR_NULL(segs)) {
314 if (copy_dtor) {
315 gso_skb->destructor = sock_wfree;
316 gso_skb->sk = sk;
317 }
318 return segs;
319 }
320
321 /* GSO partial and frag_list segmentation only requires splitting
322 * the frame into an MSS multiple and possibly a remainder, both
323 * cases return a GSO skb. So update the mss now.
324 */
325 if (skb_is_gso(segs))
326 mss *= skb_shinfo(segs)->gso_segs;
327
328 seg = segs;
329 uh = udp_hdr(seg);
330
331 /* preserve TX timestamp flags and TS key for first segment */
332 skb_shinfo(seg)->tskey = skb_shinfo(gso_skb)->tskey;
333 skb_shinfo(seg)->tx_flags |=
334 (skb_shinfo(gso_skb)->tx_flags & SKBTX_ANY_TSTAMP);
335
336 /* compute checksum adjustment based on old length versus new */
337 newlen = htons(sizeof(*uh) + mss);
338 check = csum16_add(csum16_sub(uh->check, uh->len), newlen);
339
340 for (;;) {
341 if (copy_dtor) {
342 seg->destructor = sock_wfree;
343 seg->sk = sk;
344 sum_truesize += seg->truesize;
345 }
346
347 if (!seg->next)
348 break;
349
350 uh->len = newlen;
351 uh->check = check;
352
353 if (seg->ip_summed == CHECKSUM_PARTIAL)
354 gso_reset_checksum(seg, ~check);
355 else
356 uh->check = gso_make_checksum(seg, ~check) ? :
357 CSUM_MANGLED_0;
358
359 seg = seg->next;
360 uh = udp_hdr(seg);
361 }
362
363 /* last packet can be partial gso_size, account for that in checksum */
364 newlen = htons(skb_tail_pointer(seg) - skb_transport_header(seg) +
365 seg->data_len);
366 check = csum16_add(csum16_sub(uh->check, uh->len), newlen);
367
368 uh->len = newlen;
369 uh->check = check;
370
371 if (seg->ip_summed == CHECKSUM_PARTIAL)
372 gso_reset_checksum(seg, ~check);
373 else
374 uh->check = gso_make_checksum(seg, ~check) ? : CSUM_MANGLED_0;
375
376 /* update refcount for the packet */
377 if (copy_dtor) {
378 int delta = sum_truesize - gso_skb->truesize;
379
380 /* In some pathological cases, delta can be negative.
381 * We need to either use refcount_add() or refcount_sub_and_test()
382 */
383 if (likely(delta >= 0))
384 refcount_add(delta, &sk->sk_wmem_alloc);
385 else
386 WARN_ON_ONCE(refcount_sub_and_test(-delta, &sk->sk_wmem_alloc));
387 }
388 return segs;
389 }
390 EXPORT_SYMBOL_GPL(__udp_gso_segment);
391
udp4_ufo_fragment(struct sk_buff * skb,netdev_features_t features)392 static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
393 netdev_features_t features)
394 {
395 struct sk_buff *segs = ERR_PTR(-EINVAL);
396 unsigned int mss;
397 __wsum csum;
398 struct udphdr *uh;
399 struct iphdr *iph;
400
401 if (skb->encapsulation &&
402 (skb_shinfo(skb)->gso_type &
403 (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) {
404 segs = skb_udp_tunnel_segment(skb, features, false);
405 goto out;
406 }
407
408 if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_UDP | SKB_GSO_UDP_L4)))
409 goto out;
410
411 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
412 goto out;
413
414 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
415 return __udp_gso_segment(skb, features, false);
416
417 mss = skb_shinfo(skb)->gso_size;
418 if (unlikely(skb->len <= mss))
419 goto out;
420
421 /* Do software UFO. Complete and fill in the UDP checksum as
422 * HW cannot do checksum of UDP packets sent as multiple
423 * IP fragments.
424 */
425
426 uh = udp_hdr(skb);
427 iph = ip_hdr(skb);
428
429 uh->check = 0;
430 csum = skb_checksum(skb, 0, skb->len, 0);
431 uh->check = udp_v4_check(skb->len, iph->saddr, iph->daddr, csum);
432 if (uh->check == 0)
433 uh->check = CSUM_MANGLED_0;
434
435 skb->ip_summed = CHECKSUM_UNNECESSARY;
436
437 /* If there is no outer header we can fake a checksum offload
438 * due to the fact that we have already done the checksum in
439 * software prior to segmenting the frame.
440 */
441 if (!skb->encap_hdr_csum)
442 features |= NETIF_F_HW_CSUM;
443
444 /* Fragment the skb. IP headers of the fragments are updated in
445 * inet_gso_segment()
446 */
447 segs = skb_segment(skb, features);
448 out:
449 return segs;
450 }
451
452 #define UDP_GRO_CNT_MAX 64
udp_gro_receive_segment(struct list_head * head,struct sk_buff * skb)453 static struct sk_buff *udp_gro_receive_segment(struct list_head *head,
454 struct sk_buff *skb)
455 {
456 struct udphdr *uh = udp_gro_udphdr(skb);
457 struct sk_buff *pp = NULL;
458 struct udphdr *uh2;
459 struct sk_buff *p;
460 unsigned int ulen;
461 int ret = 0;
462
463 /* requires non zero csum, for symmetry with GSO */
464 if (!uh->check) {
465 NAPI_GRO_CB(skb)->flush = 1;
466 return NULL;
467 }
468
469 /* Do not deal with padded or malicious packets, sorry ! */
470 ulen = ntohs(uh->len);
471 if (ulen <= sizeof(*uh) || ulen != skb_gro_len(skb)) {
472 NAPI_GRO_CB(skb)->flush = 1;
473 return NULL;
474 }
475 /* pull encapsulating udp header */
476 skb_gro_pull(skb, sizeof(struct udphdr));
477
478 list_for_each_entry(p, head, list) {
479 if (!NAPI_GRO_CB(p)->same_flow)
480 continue;
481
482 uh2 = udp_hdr(p);
483
484 /* Match ports only, as csum is always non zero */
485 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source)) {
486 NAPI_GRO_CB(p)->same_flow = 0;
487 continue;
488 }
489
490 if (NAPI_GRO_CB(skb)->is_flist != NAPI_GRO_CB(p)->is_flist) {
491 NAPI_GRO_CB(skb)->flush = 1;
492 return p;
493 }
494
495 /* Terminate the flow on len mismatch or if it grow "too much".
496 * Under small packet flood GRO count could elsewhere grow a lot
497 * leading to excessive truesize values.
498 * On len mismatch merge the first packet shorter than gso_size,
499 * otherwise complete the GRO packet.
500 */
501 if (ulen > ntohs(uh2->len)) {
502 pp = p;
503 } else {
504 if (NAPI_GRO_CB(skb)->is_flist) {
505 if (!pskb_may_pull(skb, skb_gro_offset(skb))) {
506 NAPI_GRO_CB(skb)->flush = 1;
507 return NULL;
508 }
509 if ((skb->ip_summed != p->ip_summed) ||
510 (skb->csum_level != p->csum_level)) {
511 NAPI_GRO_CB(skb)->flush = 1;
512 return NULL;
513 }
514 ret = skb_gro_receive_list(p, skb);
515 } else {
516 skb_gro_postpull_rcsum(skb, uh,
517 sizeof(struct udphdr));
518
519 ret = skb_gro_receive(p, skb);
520 }
521 }
522
523 if (ret || ulen != ntohs(uh2->len) ||
524 NAPI_GRO_CB(p)->count >= UDP_GRO_CNT_MAX)
525 pp = p;
526
527 return pp;
528 }
529
530 /* mismatch, but we never need to flush */
531 return NULL;
532 }
533
udp_gro_receive(struct list_head * head,struct sk_buff * skb,struct udphdr * uh,struct sock * sk)534 struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb,
535 struct udphdr *uh, struct sock *sk)
536 {
537 struct sk_buff *pp = NULL;
538 struct sk_buff *p;
539 struct udphdr *uh2;
540 unsigned int off = skb_gro_offset(skb);
541 int flush = 1;
542
543 /* We can do L4 aggregation only if the packet can't land in a tunnel
544 * otherwise we could corrupt the inner stream. Detecting such packets
545 * cannot be foolproof and the aggregation might still happen in some
546 * cases. Such packets should be caught in udp_unexpected_gso later.
547 */
548 NAPI_GRO_CB(skb)->is_flist = 0;
549 if (skb->dev->features & NETIF_F_GRO_FRAGLIST)
550 NAPI_GRO_CB(skb)->is_flist = sk ? !udp_sk(sk)->gro_enabled: 1;
551
552 if ((sk && udp_sk(sk)->gro_enabled) || NAPI_GRO_CB(skb)->is_flist) {
553 pp = call_gro_receive(udp_gro_receive_segment, head, skb);
554 return pp;
555 }
556
557 if (!sk || NAPI_GRO_CB(skb)->encap_mark ||
558 (uh->check && skb->ip_summed != CHECKSUM_PARTIAL &&
559 NAPI_GRO_CB(skb)->csum_cnt == 0 &&
560 !NAPI_GRO_CB(skb)->csum_valid) ||
561 !udp_sk(sk)->gro_receive)
562 goto out;
563
564 /* mark that this skb passed once through the tunnel gro layer */
565 NAPI_GRO_CB(skb)->encap_mark = 1;
566
567 flush = 0;
568
569 list_for_each_entry(p, head, list) {
570 if (!NAPI_GRO_CB(p)->same_flow)
571 continue;
572
573 uh2 = (struct udphdr *)(p->data + off);
574
575 /* Match ports and either checksums are either both zero
576 * or nonzero.
577 */
578 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source) ||
579 (!uh->check ^ !uh2->check)) {
580 NAPI_GRO_CB(p)->same_flow = 0;
581 continue;
582 }
583 }
584
585 skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */
586 skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr));
587 pp = call_gro_receive_sk(udp_sk(sk)->gro_receive, sk, head, skb);
588
589 out:
590 skb_gro_flush_final(skb, pp, flush);
591 return pp;
592 }
593 EXPORT_SYMBOL(udp_gro_receive);
594
udp4_gro_lookup_skb(struct sk_buff * skb,__be16 sport,__be16 dport)595 static struct sock *udp4_gro_lookup_skb(struct sk_buff *skb, __be16 sport,
596 __be16 dport)
597 {
598 const struct iphdr *iph = skb_gro_network_header(skb);
599
600 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
601 iph->daddr, dport, inet_iif(skb),
602 inet_sdif(skb), &udp_table, NULL);
603 }
604
605 INDIRECT_CALLABLE_SCOPE
udp4_gro_receive(struct list_head * head,struct sk_buff * skb)606 struct sk_buff *udp4_gro_receive(struct list_head *head, struct sk_buff *skb)
607 {
608 struct udphdr *uh = udp_gro_udphdr(skb);
609 struct sock *sk = NULL;
610 struct sk_buff *pp;
611
612 if (unlikely(!uh))
613 goto flush;
614
615 /* Don't bother verifying checksum if we're going to flush anyway. */
616 if (NAPI_GRO_CB(skb)->flush)
617 goto skip;
618
619 if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check,
620 inet_gro_compute_pseudo))
621 goto flush;
622 else if (uh->check)
623 skb_gro_checksum_try_convert(skb, IPPROTO_UDP,
624 inet_gro_compute_pseudo);
625 skip:
626 NAPI_GRO_CB(skb)->is_ipv6 = 0;
627 rcu_read_lock();
628
629 if (static_branch_unlikely(&udp_encap_needed_key))
630 sk = udp4_gro_lookup_skb(skb, uh->source, uh->dest);
631
632 pp = udp_gro_receive(head, skb, uh, sk);
633 rcu_read_unlock();
634 return pp;
635
636 flush:
637 NAPI_GRO_CB(skb)->flush = 1;
638 return NULL;
639 }
640
udp_gro_complete_segment(struct sk_buff * skb)641 static int udp_gro_complete_segment(struct sk_buff *skb)
642 {
643 struct udphdr *uh = udp_hdr(skb);
644
645 skb->csum_start = (unsigned char *)uh - skb->head;
646 skb->csum_offset = offsetof(struct udphdr, check);
647 skb->ip_summed = CHECKSUM_PARTIAL;
648
649 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
650 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_L4;
651
652 if (skb->encapsulation)
653 skb->inner_transport_header = skb->transport_header;
654
655 return 0;
656 }
657
udp_gro_complete(struct sk_buff * skb,int nhoff,udp_lookup_t lookup)658 int udp_gro_complete(struct sk_buff *skb, int nhoff,
659 udp_lookup_t lookup)
660 {
661 __be16 newlen = htons(skb->len - nhoff);
662 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
663 int err = -ENOSYS;
664 struct sock *sk;
665
666 uh->len = newlen;
667
668 rcu_read_lock();
669 sk = INDIRECT_CALL_INET(lookup, udp6_lib_lookup_skb,
670 udp4_lib_lookup_skb, skb, uh->source, uh->dest);
671 if (sk && udp_sk(sk)->gro_complete) {
672 skb_shinfo(skb)->gso_type = uh->check ? SKB_GSO_UDP_TUNNEL_CSUM
673 : SKB_GSO_UDP_TUNNEL;
674
675 /* Set encapsulation before calling into inner gro_complete()
676 * functions to make them set up the inner offsets.
677 */
678 skb->encapsulation = 1;
679 err = udp_sk(sk)->gro_complete(sk, skb,
680 nhoff + sizeof(struct udphdr));
681 } else {
682 err = udp_gro_complete_segment(skb);
683 }
684 rcu_read_unlock();
685
686 if (skb->remcsum_offload)
687 skb_shinfo(skb)->gso_type |= SKB_GSO_TUNNEL_REMCSUM;
688
689 return err;
690 }
691 EXPORT_SYMBOL(udp_gro_complete);
692
udp4_gro_complete(struct sk_buff * skb,int nhoff)693 INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff)
694 {
695 const struct iphdr *iph = ip_hdr(skb);
696 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
697
698 if (NAPI_GRO_CB(skb)->is_flist) {
699 uh->len = htons(skb->len - nhoff);
700
701 skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4);
702 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
703
704 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
705 if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
706 skb->csum_level++;
707 } else {
708 skb->ip_summed = CHECKSUM_UNNECESSARY;
709 skb->csum_level = 0;
710 }
711
712 return 0;
713 }
714
715 if (uh->check)
716 uh->check = ~udp_v4_check(skb->len - nhoff, iph->saddr,
717 iph->daddr, 0);
718
719 return udp_gro_complete(skb, nhoff, udp4_lib_lookup_skb);
720 }
721
722 static const struct net_offload udpv4_offload = {
723 .callbacks = {
724 .gso_segment = udp4_ufo_fragment,
725 .gro_receive = udp4_gro_receive,
726 .gro_complete = udp4_gro_complete,
727 },
728 };
729
udpv4_offload_init(void)730 int __init udpv4_offload_init(void)
731 {
732 return inet_add_offload(&udpv4_offload, IPPROTO_UDP);
733 }
734