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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * xfrm_output.c - Common IPsec encapsulation code.
4 *
5 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
6 */
7
8#include <linux/errno.h>
9#include <linux/module.h>
10#include <linux/netdevice.h>
11#include <linux/netfilter.h>
12#include <linux/skbuff.h>
13#include <linux/slab.h>
14#include <linux/spinlock.h>
15#include <net/dst.h>
16#include <net/inet_ecn.h>
17#include <net/xfrm.h>
18
19#include "xfrm_inout.h"
20
21static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb);
22static int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb);
23
24static int xfrm_skb_check_space(struct sk_buff *skb)
25{
26 struct dst_entry *dst = skb_dst(skb);
27 int nhead = dst->header_len + LL_RESERVED_SPACE(dst->dev)
28 - skb_headroom(skb);
29 int ntail = dst->dev->needed_tailroom - skb_tailroom(skb);
30
31 if (nhead <= 0) {
32 if (ntail <= 0)
33 return 0;
34 nhead = 0;
35 } else if (ntail < 0)
36 ntail = 0;
37
38 return pskb_expand_head(skb, nhead, ntail, GFP_ATOMIC);
39}
40
41/* Children define the path of the packet through the
42 * Linux networking. Thus, destinations are stackable.
43 */
44
45static struct dst_entry *skb_dst_pop(struct sk_buff *skb)
46{
47 struct dst_entry *child = dst_clone(xfrm_dst_child(skb_dst(skb)));
48
49 skb_dst_drop(skb);
50 return child;
51}
52
53/* Add encapsulation header.
54 *
55 * The IP header will be moved forward to make space for the encapsulation
56 * header.
57 */
58static int xfrm4_transport_output(struct xfrm_state *x, struct sk_buff *skb)
59{
60 struct iphdr *iph = ip_hdr(skb);
61 int ihl = iph->ihl * 4;
62
63 skb_set_inner_transport_header(skb, skb_transport_offset(skb));
64
65 skb_set_network_header(skb, -x->props.header_len);
66 skb->mac_header = skb->network_header +
67 offsetof(struct iphdr, protocol);
68 skb->transport_header = skb->network_header + ihl;
69 __skb_pull(skb, ihl);
70 memmove(skb_network_header(skb), iph, ihl);
71 return 0;
72}
73
74/* Add encapsulation header.
75 *
76 * The IP header and mutable extension headers will be moved forward to make
77 * space for the encapsulation header.
78 */
79static int xfrm6_transport_output(struct xfrm_state *x, struct sk_buff *skb)
80{
81#if IS_ENABLED(CONFIG_IPV6)
82 struct ipv6hdr *iph;
83 u8 *prevhdr;
84 int hdr_len;
85
86 iph = ipv6_hdr(skb);
87 skb_set_inner_transport_header(skb, skb_transport_offset(skb));
88
89 hdr_len = x->type->hdr_offset(x, skb, &prevhdr);
90 if (hdr_len < 0)
91 return hdr_len;
92 skb_set_mac_header(skb,
93 (prevhdr - x->props.header_len) - skb->data);
94 skb_set_network_header(skb, -x->props.header_len);
95 skb->transport_header = skb->network_header + hdr_len;
96 __skb_pull(skb, hdr_len);
97 memmove(ipv6_hdr(skb), iph, hdr_len);
98 return 0;
99#else
100 WARN_ON_ONCE(1);
101 return -EAFNOSUPPORT;
102#endif
103}
104
105/* Add route optimization header space.
106 *
107 * The IP header and mutable extension headers will be moved forward to make
108 * space for the route optimization header.
109 */
110static int xfrm6_ro_output(struct xfrm_state *x, struct sk_buff *skb)
111{
112#if IS_ENABLED(CONFIG_IPV6)
113 struct ipv6hdr *iph;
114 u8 *prevhdr;
115 int hdr_len;
116
117 iph = ipv6_hdr(skb);
118
119 hdr_len = x->type->hdr_offset(x, skb, &prevhdr);
120 if (hdr_len < 0)
121 return hdr_len;
122 skb_set_mac_header(skb,
123 (prevhdr - x->props.header_len) - skb->data);
124 skb_set_network_header(skb, -x->props.header_len);
125 skb->transport_header = skb->network_header + hdr_len;
126 __skb_pull(skb, hdr_len);
127 memmove(ipv6_hdr(skb), iph, hdr_len);
128
129 x->lastused = ktime_get_real_seconds();
130
131 return 0;
132#else
133 WARN_ON_ONCE(1);
134 return -EAFNOSUPPORT;
135#endif
136}
137
138/* Add encapsulation header.
139 *
140 * The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.
141 */
142static int xfrm4_beet_encap_add(struct xfrm_state *x, struct sk_buff *skb)
143{
144 struct ip_beet_phdr *ph;
145 struct iphdr *top_iph;
146 int hdrlen, optlen;
147
148 hdrlen = 0;
149 optlen = XFRM_MODE_SKB_CB(skb)->optlen;
150 if (unlikely(optlen))
151 hdrlen += IPV4_BEET_PHMAXLEN - (optlen & 4);
152
153 skb_set_network_header(skb, -x->props.header_len - hdrlen +
154 (XFRM_MODE_SKB_CB(skb)->ihl - sizeof(*top_iph)));
155 if (x->sel.family != AF_INET6)
156 skb->network_header += IPV4_BEET_PHMAXLEN;
157 skb->mac_header = skb->network_header +
158 offsetof(struct iphdr, protocol);
159 skb->transport_header = skb->network_header + sizeof(*top_iph);
160
161 xfrm4_beet_make_header(skb);
162
163 ph = __skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl - hdrlen);
164
165 top_iph = ip_hdr(skb);
166
167 if (unlikely(optlen)) {
168 if (WARN_ON(optlen < 0))
169 return -EINVAL;
170
171 ph->padlen = 4 - (optlen & 4);
172 ph->hdrlen = optlen / 8;
173 ph->nexthdr = top_iph->protocol;
174 if (ph->padlen)
175 memset(ph + 1, IPOPT_NOP, ph->padlen);
176
177 top_iph->protocol = IPPROTO_BEETPH;
178 top_iph->ihl = sizeof(struct iphdr) / 4;
179 }
180
181 top_iph->saddr = x->props.saddr.a4;
182 top_iph->daddr = x->id.daddr.a4;
183
184 return 0;
185}
186
187/* Add encapsulation header.
188 *
189 * The top IP header will be constructed per RFC 2401.
190 */
191static int xfrm4_tunnel_encap_add(struct xfrm_state *x, struct sk_buff *skb)
192{
193 struct dst_entry *dst = skb_dst(skb);
194 struct iphdr *top_iph;
195 int flags;
196
197 skb_set_inner_network_header(skb, skb_network_offset(skb));
198 skb_set_inner_transport_header(skb, skb_transport_offset(skb));
199
200 skb_set_network_header(skb, -x->props.header_len);
201 skb->mac_header = skb->network_header +
202 offsetof(struct iphdr, protocol);
203 skb->transport_header = skb->network_header + sizeof(*top_iph);
204 top_iph = ip_hdr(skb);
205
206 top_iph->ihl = 5;
207 top_iph->version = 4;
208
209 top_iph->protocol = xfrm_af2proto(skb_dst(skb)->ops->family);
210
211 /* DS disclosing depends on XFRM_SA_XFLAG_DONT_ENCAP_DSCP */
212 if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
213 top_iph->tos = 0;
214 else
215 top_iph->tos = XFRM_MODE_SKB_CB(skb)->tos;
216 top_iph->tos = INET_ECN_encapsulate(top_iph->tos,
217 XFRM_MODE_SKB_CB(skb)->tos);
218
219 flags = x->props.flags;
220 if (flags & XFRM_STATE_NOECN)
221 IP_ECN_clear(top_iph);
222
223 top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
224 0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF));
225
226 top_iph->ttl = ip4_dst_hoplimit(xfrm_dst_child(dst));
227
228 top_iph->saddr = x->props.saddr.a4;
229 top_iph->daddr = x->id.daddr.a4;
230 ip_select_ident(dev_net(dst->dev), skb, NULL);
231
232 return 0;
233}
234
235#if IS_ENABLED(CONFIG_IPV6)
236static int xfrm6_tunnel_encap_add(struct xfrm_state *x, struct sk_buff *skb)
237{
238 struct dst_entry *dst = skb_dst(skb);
239 struct ipv6hdr *top_iph;
240 int dsfield;
241
242 skb_set_inner_network_header(skb, skb_network_offset(skb));
243 skb_set_inner_transport_header(skb, skb_transport_offset(skb));
244
245 skb_set_network_header(skb, -x->props.header_len);
246 skb->mac_header = skb->network_header +
247 offsetof(struct ipv6hdr, nexthdr);
248 skb->transport_header = skb->network_header + sizeof(*top_iph);
249 top_iph = ipv6_hdr(skb);
250
251 top_iph->version = 6;
252
253 memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
254 sizeof(top_iph->flow_lbl));
255 top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family);
256
257 if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
258 dsfield = 0;
259 else
260 dsfield = XFRM_MODE_SKB_CB(skb)->tos;
261 dsfield = INET_ECN_encapsulate(dsfield, XFRM_MODE_SKB_CB(skb)->tos);
262 if (x->props.flags & XFRM_STATE_NOECN)
263 dsfield &= ~INET_ECN_MASK;
264 ipv6_change_dsfield(top_iph, 0, dsfield);
265 top_iph->hop_limit = ip6_dst_hoplimit(xfrm_dst_child(dst));
266 top_iph->saddr = *(struct in6_addr *)&x->props.saddr;
267 top_iph->daddr = *(struct in6_addr *)&x->id.daddr;
268 return 0;
269}
270
271static int xfrm6_beet_encap_add(struct xfrm_state *x, struct sk_buff *skb)
272{
273 struct ipv6hdr *top_iph;
274 struct ip_beet_phdr *ph;
275 int optlen, hdr_len;
276
277 hdr_len = 0;
278 optlen = XFRM_MODE_SKB_CB(skb)->optlen;
279 if (unlikely(optlen))
280 hdr_len += IPV4_BEET_PHMAXLEN - (optlen & 4);
281
282 skb_set_network_header(skb, -x->props.header_len - hdr_len);
283 if (x->sel.family != AF_INET6)
284 skb->network_header += IPV4_BEET_PHMAXLEN;
285 skb->mac_header = skb->network_header +
286 offsetof(struct ipv6hdr, nexthdr);
287 skb->transport_header = skb->network_header + sizeof(*top_iph);
288 ph = __skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl - hdr_len);
289
290 xfrm6_beet_make_header(skb);
291
292 top_iph = ipv6_hdr(skb);
293 if (unlikely(optlen)) {
294 if (WARN_ON(optlen < 0))
295 return -EINVAL;
296
297 ph->padlen = 4 - (optlen & 4);
298 ph->hdrlen = optlen / 8;
299 ph->nexthdr = top_iph->nexthdr;
300 if (ph->padlen)
301 memset(ph + 1, IPOPT_NOP, ph->padlen);
302
303 top_iph->nexthdr = IPPROTO_BEETPH;
304 }
305
306 top_iph->saddr = *(struct in6_addr *)&x->props.saddr;
307 top_iph->daddr = *(struct in6_addr *)&x->id.daddr;
308 return 0;
309}
310#endif
311
312/* Add encapsulation header.
313 *
314 * On exit, the transport header will be set to the start of the
315 * encapsulation header to be filled in by x->type->output and the mac
316 * header will be set to the nextheader (protocol for IPv4) field of the
317 * extension header directly preceding the encapsulation header, or in
318 * its absence, that of the top IP header.
319 * The value of the network header will always point to the top IP header
320 * while skb->data will point to the payload.
321 */
322static int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
323{
324 int err;
325
326 err = xfrm_inner_extract_output(x, skb);
327 if (err)
328 return err;
329
330 IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
331 skb->protocol = htons(ETH_P_IP);
332
333 switch (x->outer_mode.encap) {
334 case XFRM_MODE_BEET:
335 return xfrm4_beet_encap_add(x, skb);
336 case XFRM_MODE_TUNNEL:
337 return xfrm4_tunnel_encap_add(x, skb);
338 }
339
340 WARN_ON_ONCE(1);
341 return -EOPNOTSUPP;
342}
343
344static int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
345{
346#if IS_ENABLED(CONFIG_IPV6)
347 int err;
348
349 err = xfrm_inner_extract_output(x, skb);
350 if (err)
351 return err;
352
353 skb->ignore_df = 1;
354 skb->protocol = htons(ETH_P_IPV6);
355
356 switch (x->outer_mode.encap) {
357 case XFRM_MODE_BEET:
358 return xfrm6_beet_encap_add(x, skb);
359 case XFRM_MODE_TUNNEL:
360 return xfrm6_tunnel_encap_add(x, skb);
361 default:
362 WARN_ON_ONCE(1);
363 return -EOPNOTSUPP;
364 }
365#endif
366 WARN_ON_ONCE(1);
367 return -EAFNOSUPPORT;
368}
369
370static int xfrm_outer_mode_output(struct xfrm_state *x, struct sk_buff *skb)
371{
372 switch (x->outer_mode.encap) {
373 case XFRM_MODE_BEET:
374 case XFRM_MODE_TUNNEL:
375 if (x->outer_mode.family == AF_INET)
376 return xfrm4_prepare_output(x, skb);
377 if (x->outer_mode.family == AF_INET6)
378 return xfrm6_prepare_output(x, skb);
379 break;
380 case XFRM_MODE_TRANSPORT:
381 if (x->outer_mode.family == AF_INET)
382 return xfrm4_transport_output(x, skb);
383 if (x->outer_mode.family == AF_INET6)
384 return xfrm6_transport_output(x, skb);
385 break;
386 case XFRM_MODE_ROUTEOPTIMIZATION:
387 if (x->outer_mode.family == AF_INET6)
388 return xfrm6_ro_output(x, skb);
389 WARN_ON_ONCE(1);
390 break;
391 default:
392 WARN_ON_ONCE(1);
393 break;
394 }
395
396 return -EOPNOTSUPP;
397}
398
399#if IS_ENABLED(CONFIG_NET_PKTGEN)
400int pktgen_xfrm_outer_mode_output(struct xfrm_state *x, struct sk_buff *skb)
401{
402 return xfrm_outer_mode_output(x, skb);
403}
404EXPORT_SYMBOL_GPL(pktgen_xfrm_outer_mode_output);
405#endif
406
407static int xfrm_output_one(struct sk_buff *skb, int err)
408{
409 struct dst_entry *dst = skb_dst(skb);
410 struct xfrm_state *x = dst->xfrm;
411 struct net *net = xs_net(x);
412
413 if (err <= 0)
414 goto resume;
415
416 do {
417 err = xfrm_skb_check_space(skb);
418 if (err) {
419 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
420 goto error_nolock;
421 }
422
423 skb->mark = xfrm_smark_get(skb->mark, x);
424
425 err = xfrm_outer_mode_output(x, skb);
426 if (err) {
427 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEMODEERROR);
428 goto error_nolock;
429 }
430
431 spin_lock_bh(&x->lock);
432
433 if (unlikely(x->km.state != XFRM_STATE_VALID)) {
434 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEINVALID);
435 err = -EINVAL;
436 goto error;
437 }
438
439 err = xfrm_state_check_expire(x);
440 if (err) {
441 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEEXPIRED);
442 goto error;
443 }
444
445 err = x->repl->overflow(x, skb);
446 if (err) {
447 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR);
448 goto error;
449 }
450
451 x->curlft.bytes += skb->len;
452 x->curlft.packets++;
453
454 spin_unlock_bh(&x->lock);
455
456 skb_dst_force(skb);
457 if (!skb_dst(skb)) {
458 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
459 err = -EHOSTUNREACH;
460 goto error_nolock;
461 }
462
463 if (xfrm_offload(skb)) {
464 x->type_offload->encap(x, skb);
465 } else {
466 /* Inner headers are invalid now. */
467 skb->encapsulation = 0;
468
469 err = x->type->output(x, skb);
470 if (err == -EINPROGRESS)
471 goto out;
472 }
473
474resume:
475 if (err) {
476 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR);
477 goto error_nolock;
478 }
479
480 dst = skb_dst_pop(skb);
481 if (!dst) {
482 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
483 err = -EHOSTUNREACH;
484 goto error_nolock;
485 }
486 skb_dst_set(skb, dst);
487 x = dst->xfrm;
488 } while (x && !(x->outer_mode.flags & XFRM_MODE_FLAG_TUNNEL));
489
490 return 0;
491
492error:
493 spin_unlock_bh(&x->lock);
494error_nolock:
495 kfree_skb(skb);
496out:
497 return err;
498}
499
500int xfrm_output_resume(struct sk_buff *skb, int err)
501{
502 struct net *net = xs_net(skb_dst(skb)->xfrm);
503
504 while (likely((err = xfrm_output_one(skb, err)) == 0)) {
505 nf_reset_ct(skb);
506
507 err = skb_dst(skb)->ops->local_out(net, skb->sk, skb);
508 if (unlikely(err != 1))
509 goto out;
510
511 if (!skb_dst(skb)->xfrm)
512 return dst_output(net, skb->sk, skb);
513
514 err = nf_hook(skb_dst(skb)->ops->family,
515 NF_INET_POST_ROUTING, net, skb->sk, skb,
516 NULL, skb_dst(skb)->dev, xfrm_output2);
517 if (unlikely(err != 1))
518 goto out;
519 }
520
521 if (err == -EINPROGRESS)
522 err = 0;
523
524out:
525 return err;
526}
527EXPORT_SYMBOL_GPL(xfrm_output_resume);
528
529static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb)
530{
531 return xfrm_output_resume(skb, 1);
532}
533
534static int xfrm_output_gso(struct net *net, struct sock *sk, struct sk_buff *skb)
535{
536 struct sk_buff *segs;
537
538 BUILD_BUG_ON(sizeof(*IPCB(skb)) > SKB_SGO_CB_OFFSET);
539 BUILD_BUG_ON(sizeof(*IP6CB(skb)) > SKB_SGO_CB_OFFSET);
540 segs = skb_gso_segment(skb, 0);
541 kfree_skb(skb);
542 if (IS_ERR(segs))
543 return PTR_ERR(segs);
544 if (segs == NULL)
545 return -EINVAL;
546
547 do {
548 struct sk_buff *nskb = segs->next;
549 int err;
550
551 skb_mark_not_on_list(segs);
552 err = xfrm_output2(net, sk, segs);
553
554 if (unlikely(err)) {
555 kfree_skb_list(nskb);
556 return err;
557 }
558
559 segs = nskb;
560 } while (segs);
561
562 return 0;
563}
564
565int xfrm_output(struct sock *sk, struct sk_buff *skb)
566{
567 struct net *net = dev_net(skb_dst(skb)->dev);
568 struct xfrm_state *x = skb_dst(skb)->xfrm;
569 int err;
570
571 secpath_reset(skb);
572
573 if (xfrm_dev_offload_ok(skb, x)) {
574 struct sec_path *sp;
575
576 sp = secpath_set(skb);
577 if (!sp) {
578 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
579 kfree_skb(skb);
580 return -ENOMEM;
581 }
582 skb->encapsulation = 1;
583
584 sp->olen++;
585 sp->xvec[sp->len++] = x;
586 xfrm_state_hold(x);
587
588 if (skb_is_gso(skb)) {
589 skb_shinfo(skb)->gso_type |= SKB_GSO_ESP;
590
591 return xfrm_output2(net, sk, skb);
592 }
593
594 if (x->xso.dev && x->xso.dev->features & NETIF_F_HW_ESP_TX_CSUM)
595 goto out;
596 }
597
598 if (skb_is_gso(skb))
599 return xfrm_output_gso(net, sk, skb);
600
601 if (skb->ip_summed == CHECKSUM_PARTIAL) {
602 err = skb_checksum_help(skb);
603 if (err) {
604 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
605 kfree_skb(skb);
606 return err;
607 }
608 }
609
610out:
611 return xfrm_output2(net, sk, skb);
612}
613EXPORT_SYMBOL_GPL(xfrm_output);
614
615static int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb)
616{
617 const struct xfrm_state_afinfo *afinfo;
618 const struct xfrm_mode *inner_mode;
619 int err = -EAFNOSUPPORT;
620
621 if (x->sel.family == AF_UNSPEC)
622 inner_mode = xfrm_ip2inner_mode(x,
623 xfrm_af2proto(skb_dst(skb)->ops->family));
624 else
625 inner_mode = &x->inner_mode;
626
627 if (inner_mode == NULL)
628 return -EAFNOSUPPORT;
629
630 rcu_read_lock();
631 afinfo = xfrm_state_afinfo_get_rcu(inner_mode->family);
632 if (likely(afinfo))
633 err = afinfo->extract_output(x, skb);
634 rcu_read_unlock();
635
636 return err;
637}
638
639void xfrm_local_error(struct sk_buff *skb, int mtu)
640{
641 unsigned int proto;
642 struct xfrm_state_afinfo *afinfo;
643
644 if (skb->protocol == htons(ETH_P_IP))
645 proto = AF_INET;
646 else if (skb->protocol == htons(ETH_P_IPV6))
647 proto = AF_INET6;
648 else
649 return;
650
651 afinfo = xfrm_state_get_afinfo(proto);
652 if (afinfo) {
653 afinfo->local_error(skb, mtu);
654 rcu_read_unlock();
655 }
656}
657EXPORT_SYMBOL_GPL(xfrm_local_error);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * xfrm_output.c - Common IPsec encapsulation code.
4 *
5 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
6 */
7
8#include <linux/errno.h>
9#include <linux/module.h>
10#include <linux/netdevice.h>
11#include <linux/netfilter.h>
12#include <linux/skbuff.h>
13#include <linux/slab.h>
14#include <linux/spinlock.h>
15#include <net/dst.h>
16#include <net/icmp.h>
17#include <net/inet_ecn.h>
18#include <net/xfrm.h>
19
20#if IS_ENABLED(CONFIG_IPV6)
21#include <net/ip6_route.h>
22#include <net/ipv6_stubs.h>
23#endif
24
25#include "xfrm_inout.h"
26
27static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb);
28static int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb);
29
30static int xfrm_skb_check_space(struct sk_buff *skb)
31{
32 struct dst_entry *dst = skb_dst(skb);
33 int nhead = dst->header_len + LL_RESERVED_SPACE(dst->dev)
34 - skb_headroom(skb);
35 int ntail = dst->dev->needed_tailroom - skb_tailroom(skb);
36
37 if (nhead <= 0) {
38 if (ntail <= 0)
39 return 0;
40 nhead = 0;
41 } else if (ntail < 0)
42 ntail = 0;
43
44 return pskb_expand_head(skb, nhead, ntail, GFP_ATOMIC);
45}
46
47/* Children define the path of the packet through the
48 * Linux networking. Thus, destinations are stackable.
49 */
50
51static struct dst_entry *skb_dst_pop(struct sk_buff *skb)
52{
53 struct dst_entry *child = dst_clone(xfrm_dst_child(skb_dst(skb)));
54
55 skb_dst_drop(skb);
56 return child;
57}
58
59/* Add encapsulation header.
60 *
61 * The IP header will be moved forward to make space for the encapsulation
62 * header.
63 */
64static int xfrm4_transport_output(struct xfrm_state *x, struct sk_buff *skb)
65{
66 struct iphdr *iph = ip_hdr(skb);
67 int ihl = iph->ihl * 4;
68
69 skb_set_inner_transport_header(skb, skb_transport_offset(skb));
70
71 skb_set_network_header(skb, -x->props.header_len);
72 skb->mac_header = skb->network_header +
73 offsetof(struct iphdr, protocol);
74 skb->transport_header = skb->network_header + ihl;
75 __skb_pull(skb, ihl);
76 memmove(skb_network_header(skb), iph, ihl);
77 return 0;
78}
79
80/* Add encapsulation header.
81 *
82 * The IP header and mutable extension headers will be moved forward to make
83 * space for the encapsulation header.
84 */
85static int xfrm6_transport_output(struct xfrm_state *x, struct sk_buff *skb)
86{
87#if IS_ENABLED(CONFIG_IPV6)
88 struct ipv6hdr *iph;
89 u8 *prevhdr;
90 int hdr_len;
91
92 iph = ipv6_hdr(skb);
93 skb_set_inner_transport_header(skb, skb_transport_offset(skb));
94
95 hdr_len = x->type->hdr_offset(x, skb, &prevhdr);
96 if (hdr_len < 0)
97 return hdr_len;
98 skb_set_mac_header(skb,
99 (prevhdr - x->props.header_len) - skb->data);
100 skb_set_network_header(skb, -x->props.header_len);
101 skb->transport_header = skb->network_header + hdr_len;
102 __skb_pull(skb, hdr_len);
103 memmove(ipv6_hdr(skb), iph, hdr_len);
104 return 0;
105#else
106 WARN_ON_ONCE(1);
107 return -EAFNOSUPPORT;
108#endif
109}
110
111/* Add route optimization header space.
112 *
113 * The IP header and mutable extension headers will be moved forward to make
114 * space for the route optimization header.
115 */
116static int xfrm6_ro_output(struct xfrm_state *x, struct sk_buff *skb)
117{
118#if IS_ENABLED(CONFIG_IPV6)
119 struct ipv6hdr *iph;
120 u8 *prevhdr;
121 int hdr_len;
122
123 iph = ipv6_hdr(skb);
124
125 hdr_len = x->type->hdr_offset(x, skb, &prevhdr);
126 if (hdr_len < 0)
127 return hdr_len;
128 skb_set_mac_header(skb,
129 (prevhdr - x->props.header_len) - skb->data);
130 skb_set_network_header(skb, -x->props.header_len);
131 skb->transport_header = skb->network_header + hdr_len;
132 __skb_pull(skb, hdr_len);
133 memmove(ipv6_hdr(skb), iph, hdr_len);
134
135 x->lastused = ktime_get_real_seconds();
136
137 return 0;
138#else
139 WARN_ON_ONCE(1);
140 return -EAFNOSUPPORT;
141#endif
142}
143
144/* Add encapsulation header.
145 *
146 * The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.
147 */
148static int xfrm4_beet_encap_add(struct xfrm_state *x, struct sk_buff *skb)
149{
150 struct ip_beet_phdr *ph;
151 struct iphdr *top_iph;
152 int hdrlen, optlen;
153
154 hdrlen = 0;
155 optlen = XFRM_MODE_SKB_CB(skb)->optlen;
156 if (unlikely(optlen))
157 hdrlen += IPV4_BEET_PHMAXLEN - (optlen & 4);
158
159 skb_set_network_header(skb, -x->props.header_len - hdrlen +
160 (XFRM_MODE_SKB_CB(skb)->ihl - sizeof(*top_iph)));
161 if (x->sel.family != AF_INET6)
162 skb->network_header += IPV4_BEET_PHMAXLEN;
163 skb->mac_header = skb->network_header +
164 offsetof(struct iphdr, protocol);
165 skb->transport_header = skb->network_header + sizeof(*top_iph);
166
167 xfrm4_beet_make_header(skb);
168
169 ph = __skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl - hdrlen);
170
171 top_iph = ip_hdr(skb);
172
173 if (unlikely(optlen)) {
174 if (WARN_ON(optlen < 0))
175 return -EINVAL;
176
177 ph->padlen = 4 - (optlen & 4);
178 ph->hdrlen = optlen / 8;
179 ph->nexthdr = top_iph->protocol;
180 if (ph->padlen)
181 memset(ph + 1, IPOPT_NOP, ph->padlen);
182
183 top_iph->protocol = IPPROTO_BEETPH;
184 top_iph->ihl = sizeof(struct iphdr) / 4;
185 }
186
187 top_iph->saddr = x->props.saddr.a4;
188 top_iph->daddr = x->id.daddr.a4;
189
190 return 0;
191}
192
193/* Add encapsulation header.
194 *
195 * The top IP header will be constructed per RFC 2401.
196 */
197static int xfrm4_tunnel_encap_add(struct xfrm_state *x, struct sk_buff *skb)
198{
199 struct dst_entry *dst = skb_dst(skb);
200 struct iphdr *top_iph;
201 int flags;
202
203 skb_set_inner_network_header(skb, skb_network_offset(skb));
204 skb_set_inner_transport_header(skb, skb_transport_offset(skb));
205
206 skb_set_network_header(skb, -x->props.header_len);
207 skb->mac_header = skb->network_header +
208 offsetof(struct iphdr, protocol);
209 skb->transport_header = skb->network_header + sizeof(*top_iph);
210 top_iph = ip_hdr(skb);
211
212 top_iph->ihl = 5;
213 top_iph->version = 4;
214
215 top_iph->protocol = xfrm_af2proto(skb_dst(skb)->ops->family);
216
217 /* DS disclosing depends on XFRM_SA_XFLAG_DONT_ENCAP_DSCP */
218 if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
219 top_iph->tos = 0;
220 else
221 top_iph->tos = XFRM_MODE_SKB_CB(skb)->tos;
222 top_iph->tos = INET_ECN_encapsulate(top_iph->tos,
223 XFRM_MODE_SKB_CB(skb)->tos);
224
225 flags = x->props.flags;
226 if (flags & XFRM_STATE_NOECN)
227 IP_ECN_clear(top_iph);
228
229 top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
230 0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF));
231
232 top_iph->ttl = ip4_dst_hoplimit(xfrm_dst_child(dst));
233
234 top_iph->saddr = x->props.saddr.a4;
235 top_iph->daddr = x->id.daddr.a4;
236 ip_select_ident(dev_net(dst->dev), skb, NULL);
237
238 return 0;
239}
240
241#if IS_ENABLED(CONFIG_IPV6)
242static int xfrm6_tunnel_encap_add(struct xfrm_state *x, struct sk_buff *skb)
243{
244 struct dst_entry *dst = skb_dst(skb);
245 struct ipv6hdr *top_iph;
246 int dsfield;
247
248 skb_set_inner_network_header(skb, skb_network_offset(skb));
249 skb_set_inner_transport_header(skb, skb_transport_offset(skb));
250
251 skb_set_network_header(skb, -x->props.header_len);
252 skb->mac_header = skb->network_header +
253 offsetof(struct ipv6hdr, nexthdr);
254 skb->transport_header = skb->network_header + sizeof(*top_iph);
255 top_iph = ipv6_hdr(skb);
256
257 top_iph->version = 6;
258
259 memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
260 sizeof(top_iph->flow_lbl));
261 top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family);
262
263 if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
264 dsfield = 0;
265 else
266 dsfield = XFRM_MODE_SKB_CB(skb)->tos;
267 dsfield = INET_ECN_encapsulate(dsfield, XFRM_MODE_SKB_CB(skb)->tos);
268 if (x->props.flags & XFRM_STATE_NOECN)
269 dsfield &= ~INET_ECN_MASK;
270 ipv6_change_dsfield(top_iph, 0, dsfield);
271 top_iph->hop_limit = ip6_dst_hoplimit(xfrm_dst_child(dst));
272 top_iph->saddr = *(struct in6_addr *)&x->props.saddr;
273 top_iph->daddr = *(struct in6_addr *)&x->id.daddr;
274 return 0;
275}
276
277static int xfrm6_beet_encap_add(struct xfrm_state *x, struct sk_buff *skb)
278{
279 struct ipv6hdr *top_iph;
280 struct ip_beet_phdr *ph;
281 int optlen, hdr_len;
282
283 hdr_len = 0;
284 optlen = XFRM_MODE_SKB_CB(skb)->optlen;
285 if (unlikely(optlen))
286 hdr_len += IPV4_BEET_PHMAXLEN - (optlen & 4);
287
288 skb_set_network_header(skb, -x->props.header_len - hdr_len);
289 if (x->sel.family != AF_INET6)
290 skb->network_header += IPV4_BEET_PHMAXLEN;
291 skb->mac_header = skb->network_header +
292 offsetof(struct ipv6hdr, nexthdr);
293 skb->transport_header = skb->network_header + sizeof(*top_iph);
294 ph = __skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl - hdr_len);
295
296 xfrm6_beet_make_header(skb);
297
298 top_iph = ipv6_hdr(skb);
299 if (unlikely(optlen)) {
300 if (WARN_ON(optlen < 0))
301 return -EINVAL;
302
303 ph->padlen = 4 - (optlen & 4);
304 ph->hdrlen = optlen / 8;
305 ph->nexthdr = top_iph->nexthdr;
306 if (ph->padlen)
307 memset(ph + 1, IPOPT_NOP, ph->padlen);
308
309 top_iph->nexthdr = IPPROTO_BEETPH;
310 }
311
312 top_iph->saddr = *(struct in6_addr *)&x->props.saddr;
313 top_iph->daddr = *(struct in6_addr *)&x->id.daddr;
314 return 0;
315}
316#endif
317
318/* Add encapsulation header.
319 *
320 * On exit, the transport header will be set to the start of the
321 * encapsulation header to be filled in by x->type->output and the mac
322 * header will be set to the nextheader (protocol for IPv4) field of the
323 * extension header directly preceding the encapsulation header, or in
324 * its absence, that of the top IP header.
325 * The value of the network header will always point to the top IP header
326 * while skb->data will point to the payload.
327 */
328static int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
329{
330 int err;
331
332 err = xfrm_inner_extract_output(x, skb);
333 if (err)
334 return err;
335
336 IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
337 skb->protocol = htons(ETH_P_IP);
338
339 switch (x->outer_mode.encap) {
340 case XFRM_MODE_BEET:
341 return xfrm4_beet_encap_add(x, skb);
342 case XFRM_MODE_TUNNEL:
343 return xfrm4_tunnel_encap_add(x, skb);
344 }
345
346 WARN_ON_ONCE(1);
347 return -EOPNOTSUPP;
348}
349
350static int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
351{
352#if IS_ENABLED(CONFIG_IPV6)
353 int err;
354
355 err = xfrm_inner_extract_output(x, skb);
356 if (err)
357 return err;
358
359 skb->ignore_df = 1;
360 skb->protocol = htons(ETH_P_IPV6);
361
362 switch (x->outer_mode.encap) {
363 case XFRM_MODE_BEET:
364 return xfrm6_beet_encap_add(x, skb);
365 case XFRM_MODE_TUNNEL:
366 return xfrm6_tunnel_encap_add(x, skb);
367 default:
368 WARN_ON_ONCE(1);
369 return -EOPNOTSUPP;
370 }
371#endif
372 WARN_ON_ONCE(1);
373 return -EAFNOSUPPORT;
374}
375
376static int xfrm_outer_mode_output(struct xfrm_state *x, struct sk_buff *skb)
377{
378 switch (x->outer_mode.encap) {
379 case XFRM_MODE_BEET:
380 case XFRM_MODE_TUNNEL:
381 if (x->outer_mode.family == AF_INET)
382 return xfrm4_prepare_output(x, skb);
383 if (x->outer_mode.family == AF_INET6)
384 return xfrm6_prepare_output(x, skb);
385 break;
386 case XFRM_MODE_TRANSPORT:
387 if (x->outer_mode.family == AF_INET)
388 return xfrm4_transport_output(x, skb);
389 if (x->outer_mode.family == AF_INET6)
390 return xfrm6_transport_output(x, skb);
391 break;
392 case XFRM_MODE_ROUTEOPTIMIZATION:
393 if (x->outer_mode.family == AF_INET6)
394 return xfrm6_ro_output(x, skb);
395 WARN_ON_ONCE(1);
396 break;
397 default:
398 WARN_ON_ONCE(1);
399 break;
400 }
401
402 return -EOPNOTSUPP;
403}
404
405#if IS_ENABLED(CONFIG_NET_PKTGEN)
406int pktgen_xfrm_outer_mode_output(struct xfrm_state *x, struct sk_buff *skb)
407{
408 return xfrm_outer_mode_output(x, skb);
409}
410EXPORT_SYMBOL_GPL(pktgen_xfrm_outer_mode_output);
411#endif
412
413static int xfrm_output_one(struct sk_buff *skb, int err)
414{
415 struct dst_entry *dst = skb_dst(skb);
416 struct xfrm_state *x = dst->xfrm;
417 struct net *net = xs_net(x);
418
419 if (err <= 0)
420 goto resume;
421
422 do {
423 err = xfrm_skb_check_space(skb);
424 if (err) {
425 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
426 goto error_nolock;
427 }
428
429 skb->mark = xfrm_smark_get(skb->mark, x);
430
431 err = xfrm_outer_mode_output(x, skb);
432 if (err) {
433 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEMODEERROR);
434 goto error_nolock;
435 }
436
437 spin_lock_bh(&x->lock);
438
439 if (unlikely(x->km.state != XFRM_STATE_VALID)) {
440 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEINVALID);
441 err = -EINVAL;
442 goto error;
443 }
444
445 err = xfrm_state_check_expire(x);
446 if (err) {
447 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEEXPIRED);
448 goto error;
449 }
450
451 err = x->repl->overflow(x, skb);
452 if (err) {
453 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR);
454 goto error;
455 }
456
457 x->curlft.bytes += skb->len;
458 x->curlft.packets++;
459
460 spin_unlock_bh(&x->lock);
461
462 skb_dst_force(skb);
463 if (!skb_dst(skb)) {
464 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
465 err = -EHOSTUNREACH;
466 goto error_nolock;
467 }
468
469 if (xfrm_offload(skb)) {
470 x->type_offload->encap(x, skb);
471 } else {
472 /* Inner headers are invalid now. */
473 skb->encapsulation = 0;
474
475 err = x->type->output(x, skb);
476 if (err == -EINPROGRESS)
477 goto out;
478 }
479
480resume:
481 if (err) {
482 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR);
483 goto error_nolock;
484 }
485
486 dst = skb_dst_pop(skb);
487 if (!dst) {
488 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
489 err = -EHOSTUNREACH;
490 goto error_nolock;
491 }
492 skb_dst_set(skb, dst);
493 x = dst->xfrm;
494 } while (x && !(x->outer_mode.flags & XFRM_MODE_FLAG_TUNNEL));
495
496 return 0;
497
498error:
499 spin_unlock_bh(&x->lock);
500error_nolock:
501 kfree_skb(skb);
502out:
503 return err;
504}
505
506int xfrm_output_resume(struct sk_buff *skb, int err)
507{
508 struct net *net = xs_net(skb_dst(skb)->xfrm);
509
510 while (likely((err = xfrm_output_one(skb, err)) == 0)) {
511 nf_reset_ct(skb);
512
513 err = skb_dst(skb)->ops->local_out(net, skb->sk, skb);
514 if (unlikely(err != 1))
515 goto out;
516
517 if (!skb_dst(skb)->xfrm)
518 return dst_output(net, skb->sk, skb);
519
520 err = nf_hook(skb_dst(skb)->ops->family,
521 NF_INET_POST_ROUTING, net, skb->sk, skb,
522 NULL, skb_dst(skb)->dev, xfrm_output2);
523 if (unlikely(err != 1))
524 goto out;
525 }
526
527 if (err == -EINPROGRESS)
528 err = 0;
529
530out:
531 return err;
532}
533EXPORT_SYMBOL_GPL(xfrm_output_resume);
534
535static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb)
536{
537 return xfrm_output_resume(skb, 1);
538}
539
540static int xfrm_output_gso(struct net *net, struct sock *sk, struct sk_buff *skb)
541{
542 struct sk_buff *segs, *nskb;
543
544 BUILD_BUG_ON(sizeof(*IPCB(skb)) > SKB_GSO_CB_OFFSET);
545 BUILD_BUG_ON(sizeof(*IP6CB(skb)) > SKB_GSO_CB_OFFSET);
546 segs = skb_gso_segment(skb, 0);
547 kfree_skb(skb);
548 if (IS_ERR(segs))
549 return PTR_ERR(segs);
550 if (segs == NULL)
551 return -EINVAL;
552
553 skb_list_walk_safe(segs, segs, nskb) {
554 int err;
555
556 skb_mark_not_on_list(segs);
557 err = xfrm_output2(net, sk, segs);
558
559 if (unlikely(err)) {
560 kfree_skb_list(nskb);
561 return err;
562 }
563 }
564
565 return 0;
566}
567
568int xfrm_output(struct sock *sk, struct sk_buff *skb)
569{
570 struct net *net = dev_net(skb_dst(skb)->dev);
571 struct xfrm_state *x = skb_dst(skb)->xfrm;
572 int err;
573
574 switch (x->outer_mode.family) {
575 case AF_INET:
576 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
577 IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
578 break;
579 case AF_INET6:
580 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
581
582 IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
583 break;
584 }
585
586 secpath_reset(skb);
587
588 if (xfrm_dev_offload_ok(skb, x)) {
589 struct sec_path *sp;
590
591 sp = secpath_set(skb);
592 if (!sp) {
593 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
594 kfree_skb(skb);
595 return -ENOMEM;
596 }
597 skb->encapsulation = 1;
598
599 sp->olen++;
600 sp->xvec[sp->len++] = x;
601 xfrm_state_hold(x);
602
603 if (skb_is_gso(skb)) {
604 if (skb->inner_protocol)
605 return xfrm_output_gso(net, sk, skb);
606
607 skb_shinfo(skb)->gso_type |= SKB_GSO_ESP;
608 goto out;
609 }
610
611 if (x->xso.dev && x->xso.dev->features & NETIF_F_HW_ESP_TX_CSUM)
612 goto out;
613 } else {
614 if (skb_is_gso(skb))
615 return xfrm_output_gso(net, sk, skb);
616 }
617
618 if (skb->ip_summed == CHECKSUM_PARTIAL) {
619 err = skb_checksum_help(skb);
620 if (err) {
621 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
622 kfree_skb(skb);
623 return err;
624 }
625 }
626
627out:
628 return xfrm_output2(net, sk, skb);
629}
630EXPORT_SYMBOL_GPL(xfrm_output);
631
632static int xfrm4_tunnel_check_size(struct sk_buff *skb)
633{
634 int mtu, ret = 0;
635
636 if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
637 goto out;
638
639 if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) || skb->ignore_df)
640 goto out;
641
642 mtu = dst_mtu(skb_dst(skb));
643 if ((!skb_is_gso(skb) && skb->len > mtu) ||
644 (skb_is_gso(skb) &&
645 !skb_gso_validate_network_len(skb, ip_skb_dst_mtu(skb->sk, skb)))) {
646 skb->protocol = htons(ETH_P_IP);
647
648 if (skb->sk)
649 xfrm_local_error(skb, mtu);
650 else
651 icmp_send(skb, ICMP_DEST_UNREACH,
652 ICMP_FRAG_NEEDED, htonl(mtu));
653 ret = -EMSGSIZE;
654 }
655out:
656 return ret;
657}
658
659static int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb)
660{
661 int err;
662
663 err = xfrm4_tunnel_check_size(skb);
664 if (err)
665 return err;
666
667 XFRM_MODE_SKB_CB(skb)->protocol = ip_hdr(skb)->protocol;
668
669 xfrm4_extract_header(skb);
670 return 0;
671}
672
673#if IS_ENABLED(CONFIG_IPV6)
674static int xfrm6_tunnel_check_size(struct sk_buff *skb)
675{
676 int mtu, ret = 0;
677 struct dst_entry *dst = skb_dst(skb);
678
679 if (skb->ignore_df)
680 goto out;
681
682 mtu = dst_mtu(dst);
683 if (mtu < IPV6_MIN_MTU)
684 mtu = IPV6_MIN_MTU;
685
686 if ((!skb_is_gso(skb) && skb->len > mtu) ||
687 (skb_is_gso(skb) &&
688 !skb_gso_validate_network_len(skb, ip6_skb_dst_mtu(skb)))) {
689 skb->dev = dst->dev;
690 skb->protocol = htons(ETH_P_IPV6);
691
692 if (xfrm6_local_dontfrag(skb->sk))
693 ipv6_stub->xfrm6_local_rxpmtu(skb, mtu);
694 else if (skb->sk)
695 xfrm_local_error(skb, mtu);
696 else
697 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
698 ret = -EMSGSIZE;
699 }
700out:
701 return ret;
702}
703#endif
704
705static int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb)
706{
707#if IS_ENABLED(CONFIG_IPV6)
708 int err;
709
710 err = xfrm6_tunnel_check_size(skb);
711 if (err)
712 return err;
713
714 XFRM_MODE_SKB_CB(skb)->protocol = ipv6_hdr(skb)->nexthdr;
715
716 xfrm6_extract_header(skb);
717 return 0;
718#else
719 WARN_ON_ONCE(1);
720 return -EAFNOSUPPORT;
721#endif
722}
723
724static int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb)
725{
726 const struct xfrm_mode *inner_mode;
727
728 if (x->sel.family == AF_UNSPEC)
729 inner_mode = xfrm_ip2inner_mode(x,
730 xfrm_af2proto(skb_dst(skb)->ops->family));
731 else
732 inner_mode = &x->inner_mode;
733
734 if (inner_mode == NULL)
735 return -EAFNOSUPPORT;
736
737 switch (inner_mode->family) {
738 case AF_INET:
739 return xfrm4_extract_output(x, skb);
740 case AF_INET6:
741 return xfrm6_extract_output(x, skb);
742 }
743
744 return -EAFNOSUPPORT;
745}
746
747void xfrm_local_error(struct sk_buff *skb, int mtu)
748{
749 unsigned int proto;
750 struct xfrm_state_afinfo *afinfo;
751
752 if (skb->protocol == htons(ETH_P_IP))
753 proto = AF_INET;
754 else if (skb->protocol == htons(ETH_P_IPV6) &&
755 skb->sk->sk_family == AF_INET6)
756 proto = AF_INET6;
757 else
758 return;
759
760 afinfo = xfrm_state_get_afinfo(proto);
761 if (afinfo) {
762 afinfo->local_error(skb, mtu);
763 rcu_read_unlock();
764 }
765}
766EXPORT_SYMBOL_GPL(xfrm_local_error);