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