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gpio: rcar: Fix runtime PM imbalance on error
[linux/fpc-iii.git] / net / ipv4 / udp_offload.c
blobe67a66fbf27b830f9c911ab9a469860d3496fff0
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 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 int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
21 bool remcsum, need_csum, offload_csum, gso_partial;
22 struct sk_buff *segs = ERR_PTR(-EINVAL);
23 struct udphdr *uh = udp_hdr(skb);
24 u16 mac_offset = skb->mac_header;
25 __be16 protocol = skb->protocol;
26 u16 mac_len = skb->mac_len;
27 int udp_offset, outer_hlen;
28 __wsum partial;
29 bool need_ipsec;
30
31 if (unlikely(!pskb_may_pull(skb, tnl_hlen)))
32 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 if (skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL)
41 partial = (__force __wsum)uh->len;
42 else
43 partial = (__force __wsum)htonl(skb->len);
44 partial = csum_sub(csum_unfold(uh->check), partial);
45
46 /* setup inner skb. */
47 skb->encapsulation = 0;
48 SKB_GSO_CB(skb)->encap_level = 0;
49 __skb_pull(skb, tnl_hlen);
50 skb_reset_mac_header(skb);
51 skb_set_network_header(skb, skb_inner_network_offset(skb));
52 skb->mac_len = skb_inner_network_offset(skb);
53 skb->protocol = new_protocol;
54
55 need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM);
56 skb->encap_hdr_csum = need_csum;
57
58 remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM);
59 skb->remcsum_offload = remcsum;
60
61 need_ipsec = skb_dst(skb) && dst_xfrm(skb_dst(skb));
62 /* Try to offload checksum if possible */
63 offload_csum = !!(need_csum &&
64 !need_ipsec &&
65 (skb->dev->features &
66 (is_ipv6 ? (NETIF_F_HW_CSUM | NETIF_F_IPV6_CSUM) :
67 (NETIF_F_HW_CSUM | NETIF_F_IP_CSUM))));
68
69 features &= skb->dev->hw_enc_features;
70
71 /* The only checksum offload we care about from here on out is the
72 * outer one so strip the existing checksum feature flags and
73 * instead set the flag based on our outer checksum offload value.
74 */
75 if (remcsum) {
76 features &= ~NETIF_F_CSUM_MASK;
77 if (!need_csum || offload_csum)
78 features |= NETIF_F_HW_CSUM;
79 }
80
81 /* segment inner packet. */
82 segs = gso_inner_segment(skb, features);
83 if (IS_ERR_OR_NULL(segs)) {
84 skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset,
85 mac_len);
86 goto out;
87 }
88
89 gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
90
91 outer_hlen = skb_tnl_header_len(skb);
92 udp_offset = outer_hlen - tnl_hlen;
93 skb = segs;
94 do {
95 unsigned int len;
96
97 if (remcsum)
98 skb->ip_summed = CHECKSUM_NONE;
99
100 /* Set up inner headers if we are offloading inner checksum */
101 if (skb->ip_summed == CHECKSUM_PARTIAL) {
102 skb_reset_inner_headers(skb);
103 skb->encapsulation = 1;
104 }
105
106 skb->mac_len = mac_len;
107 skb->protocol = protocol;
108
109 __skb_push(skb, outer_hlen);
110 skb_reset_mac_header(skb);
111 skb_set_network_header(skb, mac_len);
112 skb_set_transport_header(skb, udp_offset);
113 len = skb->len - udp_offset;
114 uh = udp_hdr(skb);
115
116 /* If we are only performing partial GSO the inner header
117 * will be using a length value equal to only one MSS sized
118 * segment instead of the entire frame.
119 */
120 if (gso_partial && skb_is_gso(skb)) {
121 uh->len = htons(skb_shinfo(skb)->gso_size +
122 SKB_GSO_CB(skb)->data_offset +
123 skb->head - (unsigned char *)uh);
124 } else {
125 uh->len = htons(len);
126 }
127
128 if (!need_csum)
129 continue;
130
131 uh->check = ~csum_fold(csum_add(partial,
132 (__force __wsum)htonl(len)));
133
134 if (skb->encapsulation || !offload_csum) {
135 uh->check = gso_make_checksum(skb, ~uh->check);
136 if (uh->check == 0)
137 uh->check = CSUM_MANGLED_0;
138 } else {
139 skb->ip_summed = CHECKSUM_PARTIAL;
140 skb->csum_start = skb_transport_header(skb) - skb->head;
141 skb->csum_offset = offsetof(struct udphdr, check);
142 }
143 } while ((skb = skb->next));
144 out:
145 return segs;
146 }
147
148 struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
149 netdev_features_t features,
150 bool is_ipv6)
151 {
152 __be16 protocol = skb->protocol;
153 const struct net_offload **offloads;
154 const struct net_offload *ops;
155 struct sk_buff *segs = ERR_PTR(-EINVAL);
156 struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb,
157 netdev_features_t features);
158
159 rcu_read_lock();
160
161 switch (skb->inner_protocol_type) {
162 case ENCAP_TYPE_ETHER:
163 protocol = skb->inner_protocol;
164 gso_inner_segment = skb_mac_gso_segment;
165 break;
166 case ENCAP_TYPE_IPPROTO:
167 offloads = is_ipv6 ? inet6_offloads : inet_offloads;
168 ops = rcu_dereference(offloads[skb->inner_ipproto]);
169 if (!ops || !ops->callbacks.gso_segment)
170 goto out_unlock;
171 gso_inner_segment = ops->callbacks.gso_segment;
172 break;
173 default:
174 goto out_unlock;
175 }
176
177 segs = __skb_udp_tunnel_segment(skb, features, gso_inner_segment,
178 protocol, is_ipv6);
179
180 out_unlock:
181 rcu_read_unlock();
182
183 return segs;
184 }
185 EXPORT_SYMBOL(skb_udp_tunnel_segment);
186
187 static struct sk_buff *__udp_gso_segment_list(struct sk_buff *skb,
188 netdev_features_t features)
189 {
190 unsigned int mss = skb_shinfo(skb)->gso_size;
191
192 skb = skb_segment_list(skb, features, skb_mac_header_len(skb));
193 if (IS_ERR(skb))
194 return skb;
195
196 udp_hdr(skb)->len = htons(sizeof(struct udphdr) + mss);
197
198 return skb;
199 }
200
201 struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
202 netdev_features_t features)
203 {
204 struct sock *sk = gso_skb->sk;
205 unsigned int sum_truesize = 0;
206 struct sk_buff *segs, *seg;
207 struct udphdr *uh;
208 unsigned int mss;
209 bool copy_dtor;
210 __sum16 check;
211 __be16 newlen;
212
213 if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST)
214 return __udp_gso_segment_list(gso_skb, features);
215
216 mss = skb_shinfo(gso_skb)->gso_size;
217 if (gso_skb->len <= sizeof(*uh) + mss)
218 return ERR_PTR(-EINVAL);
219
220 skb_pull(gso_skb, sizeof(*uh));
221
222 /* clear destructor to avoid skb_segment assigning it to tail */
223 copy_dtor = gso_skb->destructor == sock_wfree;
224 if (copy_dtor)
225 gso_skb->destructor = NULL;
226
227 segs = skb_segment(gso_skb, features);
228 if (IS_ERR_OR_NULL(segs)) {
229 if (copy_dtor)
230 gso_skb->destructor = sock_wfree;
231 return segs;
232 }
233
234 /* GSO partial and frag_list segmentation only requires splitting
235 * the frame into an MSS multiple and possibly a remainder, both
236 * cases return a GSO skb. So update the mss now.
237 */
238 if (skb_is_gso(segs))
239 mss *= skb_shinfo(segs)->gso_segs;
240
241 seg = segs;
242 uh = udp_hdr(seg);
243
244 /* preserve TX timestamp flags and TS key for first segment */
245 skb_shinfo(seg)->tskey = skb_shinfo(gso_skb)->tskey;
246 skb_shinfo(seg)->tx_flags |=
247 (skb_shinfo(gso_skb)->tx_flags & SKBTX_ANY_TSTAMP);
248
249 /* compute checksum adjustment based on old length versus new */
250 newlen = htons(sizeof(*uh) + mss);
251 check = csum16_add(csum16_sub(uh->check, uh->len), newlen);
252
253 for (;;) {
254 if (copy_dtor) {
255 seg->destructor = sock_wfree;
256 seg->sk = sk;
257 sum_truesize += seg->truesize;
258 }
259
260 if (!seg->next)
261 break;
262
263 uh->len = newlen;
264 uh->check = check;
265
266 if (seg->ip_summed == CHECKSUM_PARTIAL)
267 gso_reset_checksum(seg, ~check);
268 else
269 uh->check = gso_make_checksum(seg, ~check) ? :
270 CSUM_MANGLED_0;
271
272 seg = seg->next;
273 uh = udp_hdr(seg);
274 }
275
276 /* last packet can be partial gso_size, account for that in checksum */
277 newlen = htons(skb_tail_pointer(seg) - skb_transport_header(seg) +
278 seg->data_len);
279 check = csum16_add(csum16_sub(uh->check, uh->len), newlen);
280
281 uh->len = newlen;
282 uh->check = check;
283
284 if (seg->ip_summed == CHECKSUM_PARTIAL)
285 gso_reset_checksum(seg, ~check);
286 else
287 uh->check = gso_make_checksum(seg, ~check) ? : CSUM_MANGLED_0;
288
289 /* update refcount for the packet */
290 if (copy_dtor) {
291 int delta = sum_truesize - gso_skb->truesize;
292
293 /* In some pathological cases, delta can be negative.
294 * We need to either use refcount_add() or refcount_sub_and_test()
295 */
296 if (likely(delta >= 0))
297 refcount_add(delta, &sk->sk_wmem_alloc);
298 else
299 WARN_ON_ONCE(refcount_sub_and_test(-delta, &sk->sk_wmem_alloc));
300 }
301 return segs;
302 }
303 EXPORT_SYMBOL_GPL(__udp_gso_segment);
304
305 static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
306 netdev_features_t features)
307 {
308 struct sk_buff *segs = ERR_PTR(-EINVAL);
309 unsigned int mss;
310 __wsum csum;
311 struct udphdr *uh;
312 struct iphdr *iph;
313
314 if (skb->encapsulation &&
315 (skb_shinfo(skb)->gso_type &
316 (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) {
317 segs = skb_udp_tunnel_segment(skb, features, false);
318 goto out;
319 }
320
321 if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_UDP | SKB_GSO_UDP_L4)))
322 goto out;
323
324 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
325 goto out;
326
327 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
328 return __udp_gso_segment(skb, features);
329
330 mss = skb_shinfo(skb)->gso_size;
331 if (unlikely(skb->len <= mss))
332 goto out;
333
334 /* Do software UFO. Complete and fill in the UDP checksum as
335 * HW cannot do checksum of UDP packets sent as multiple
336 * IP fragments.
337 */
338
339 uh = udp_hdr(skb);
340 iph = ip_hdr(skb);
341
342 uh->check = 0;
343 csum = skb_checksum(skb, 0, skb->len, 0);
344 uh->check = udp_v4_check(skb->len, iph->saddr, iph->daddr, csum);
345 if (uh->check == 0)
346 uh->check = CSUM_MANGLED_0;
347
348 skb->ip_summed = CHECKSUM_UNNECESSARY;
349
350 /* If there is no outer header we can fake a checksum offload
351 * due to the fact that we have already done the checksum in
352 * software prior to segmenting the frame.
353 */
354 if (!skb->encap_hdr_csum)
355 features |= NETIF_F_HW_CSUM;
356
357 /* Fragment the skb. IP headers of the fragments are updated in
358 * inet_gso_segment()
359 */
360 segs = skb_segment(skb, features);
361 out:
362 return segs;
363 }
364
365 #define UDP_GRO_CNT_MAX 64
366 static struct sk_buff *udp_gro_receive_segment(struct list_head *head,
367 struct sk_buff *skb)
368 {
369 struct udphdr *uh = udp_hdr(skb);
370 struct sk_buff *pp = NULL;
371 struct udphdr *uh2;
372 struct sk_buff *p;
373 unsigned int ulen;
374 int ret = 0;
375
376 /* requires non zero csum, for symmetry with GSO */
377 if (!uh->check) {
378 NAPI_GRO_CB(skb)->flush = 1;
379 return NULL;
380 }
381
382 /* Do not deal with padded or malicious packets, sorry ! */
383 ulen = ntohs(uh->len);
384 if (ulen <= sizeof(*uh) || ulen != skb_gro_len(skb)) {
385 NAPI_GRO_CB(skb)->flush = 1;
386 return NULL;
387 }
388 /* pull encapsulating udp header */
389 skb_gro_pull(skb, sizeof(struct udphdr));
390
391 list_for_each_entry(p, head, list) {
392 if (!NAPI_GRO_CB(p)->same_flow)
393 continue;
394
395 uh2 = udp_hdr(p);
396
397 /* Match ports only, as csum is always non zero */
398 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source)) {
399 NAPI_GRO_CB(p)->same_flow = 0;
400 continue;
401 }
402
403 if (NAPI_GRO_CB(skb)->is_flist != NAPI_GRO_CB(p)->is_flist) {
404 NAPI_GRO_CB(skb)->flush = 1;
405 return p;
406 }
407
408 /* Terminate the flow on len mismatch or if it grow "too much".
409 * Under small packet flood GRO count could elsewhere grow a lot
410 * leading to excessive truesize values.
411 * On len mismatch merge the first packet shorter than gso_size,
412 * otherwise complete the GRO packet.
413 */
414 if (ulen > ntohs(uh2->len)) {
415 pp = p;
416 } else {
417 if (NAPI_GRO_CB(skb)->is_flist) {
418 if (!pskb_may_pull(skb, skb_gro_offset(skb))) {
419 NAPI_GRO_CB(skb)->flush = 1;
420 return NULL;
421 }
422 if ((skb->ip_summed != p->ip_summed) ||
423 (skb->csum_level != p->csum_level)) {
424 NAPI_GRO_CB(skb)->flush = 1;
425 return NULL;
426 }
427 ret = skb_gro_receive_list(p, skb);
428 } else {
429 skb_gro_postpull_rcsum(skb, uh,
430 sizeof(struct udphdr));
431
432 ret = skb_gro_receive(p, skb);
433 }
434 }
435
436 if (ret || ulen != ntohs(uh2->len) ||
437 NAPI_GRO_CB(p)->count >= UDP_GRO_CNT_MAX)
438 pp = p;
439
440 return pp;
441 }
442
443 /* mismatch, but we never need to flush */
444 return NULL;
445 }
446
447 struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb,
448 struct udphdr *uh, struct sock *sk)
449 {
450 struct sk_buff *pp = NULL;
451 struct sk_buff *p;
452 struct udphdr *uh2;
453 unsigned int off = skb_gro_offset(skb);
454 int flush = 1;
455
456 NAPI_GRO_CB(skb)->is_flist = 0;
457 if (skb->dev->features & NETIF_F_GRO_FRAGLIST)
458 NAPI_GRO_CB(skb)->is_flist = sk ? !udp_sk(sk)->gro_enabled: 1;
459
460 if ((sk && udp_sk(sk)->gro_enabled) || NAPI_GRO_CB(skb)->is_flist) {
461 pp = call_gro_receive(udp_gro_receive_segment, head, skb);
462 return pp;
463 }
464
465 if (!sk || NAPI_GRO_CB(skb)->encap_mark ||
466 (skb->ip_summed != CHECKSUM_PARTIAL &&
467 NAPI_GRO_CB(skb)->csum_cnt == 0 &&
468 !NAPI_GRO_CB(skb)->csum_valid) ||
469 !udp_sk(sk)->gro_receive)
470 goto out;
471
472 /* mark that this skb passed once through the tunnel gro layer */
473 NAPI_GRO_CB(skb)->encap_mark = 1;
474
475 flush = 0;
476
477 list_for_each_entry(p, head, list) {
478 if (!NAPI_GRO_CB(p)->same_flow)
479 continue;
480
481 uh2 = (struct udphdr *)(p->data + off);
482
483 /* Match ports and either checksums are either both zero
484 * or nonzero.
485 */
486 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source) ||
487 (!uh->check ^ !uh2->check)) {
488 NAPI_GRO_CB(p)->same_flow = 0;
489 continue;
490 }
491 }
492
493 skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */
494 skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr));
495 pp = call_gro_receive_sk(udp_sk(sk)->gro_receive, sk, head, skb);
496
497 out:
498 skb_gro_flush_final(skb, pp, flush);
499 return pp;
500 }
501 EXPORT_SYMBOL(udp_gro_receive);
502
503 INDIRECT_CALLABLE_SCOPE
504 struct sk_buff *udp4_gro_receive(struct list_head *head, struct sk_buff *skb)
505 {
506 struct udphdr *uh = udp_gro_udphdr(skb);
507 struct sk_buff *pp;
508 struct sock *sk;
509
510 if (unlikely(!uh))
511 goto flush;
512
513 /* Don't bother verifying checksum if we're going to flush anyway. */
514 if (NAPI_GRO_CB(skb)->flush)
515 goto skip;
516
517 if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check,
518 inet_gro_compute_pseudo))
519 goto flush;
520 else if (uh->check)
521 skb_gro_checksum_try_convert(skb, IPPROTO_UDP,
522 inet_gro_compute_pseudo);
523 skip:
524 NAPI_GRO_CB(skb)->is_ipv6 = 0;
525 rcu_read_lock();
526 sk = static_branch_unlikely(&udp_encap_needed_key) ? udp4_lib_lookup_skb(skb, uh->source, uh->dest) : NULL;
527 pp = udp_gro_receive(head, skb, uh, sk);
528 rcu_read_unlock();
529 return pp;
530
531 flush:
532 NAPI_GRO_CB(skb)->flush = 1;
533 return NULL;
534 }
535
536 static int udp_gro_complete_segment(struct sk_buff *skb)
537 {
538 struct udphdr *uh = udp_hdr(skb);
539
540 skb->csum_start = (unsigned char *)uh - skb->head;
541 skb->csum_offset = offsetof(struct udphdr, check);
542 skb->ip_summed = CHECKSUM_PARTIAL;
543
544 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
545 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_L4;
546 return 0;
547 }
548
549 int udp_gro_complete(struct sk_buff *skb, int nhoff,
550 udp_lookup_t lookup)
551 {
552 __be16 newlen = htons(skb->len - nhoff);
553 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
554 int err = -ENOSYS;
555 struct sock *sk;
556
557 uh->len = newlen;
558
559 rcu_read_lock();
560 sk = INDIRECT_CALL_INET(lookup, udp6_lib_lookup_skb,
561 udp4_lib_lookup_skb, skb, uh->source, uh->dest);
562 if (sk && udp_sk(sk)->gro_complete) {
563 skb_shinfo(skb)->gso_type = uh->check ? SKB_GSO_UDP_TUNNEL_CSUM
564 : SKB_GSO_UDP_TUNNEL;
565
566 /* Set encapsulation before calling into inner gro_complete()
567 * functions to make them set up the inner offsets.
568 */
569 skb->encapsulation = 1;
570 err = udp_sk(sk)->gro_complete(sk, skb,
571 nhoff + sizeof(struct udphdr));
572 } else {
573 err = udp_gro_complete_segment(skb);
574 }
575 rcu_read_unlock();
576
577 if (skb->remcsum_offload)
578 skb_shinfo(skb)->gso_type |= SKB_GSO_TUNNEL_REMCSUM;
579
580 return err;
581 }
582 EXPORT_SYMBOL(udp_gro_complete);
583
584 INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff)
585 {
586 const struct iphdr *iph = ip_hdr(skb);
587 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
588
589 if (NAPI_GRO_CB(skb)->is_flist) {
590 uh->len = htons(skb->len - nhoff);
591
592 skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4);
593 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
594
595 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
596 if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
597 skb->csum_level++;
598 } else {
599 skb->ip_summed = CHECKSUM_UNNECESSARY;
600 skb->csum_level = 0;
601 }
602
603 return 0;
604 }
605
606 if (uh->check)
607 uh->check = ~udp_v4_check(skb->len - nhoff, iph->saddr,
608 iph->daddr, 0);
609
610 return udp_gro_complete(skb, nhoff, udp4_lib_lookup_skb);
611 }
612
613 static const struct net_offload udpv4_offload = {
614 .callbacks = {
615 .gso_segment = udp4_ufo_fragment,
616 .gro_receive = udp4_gro_receive,
617 .gro_complete = udp4_gro_complete,
618 },
619 };
620
621 int __init udpv4_offload_init(void)
622 {
623 return inet_add_offload(&udpv4_offload, IPPROTO_UDP);
624 }
Linux with added FPC-III support