1// SPDX-License-Identifier: GPL-2.0
2/*
3 * xfrm_input.c
4 *
5 * Changes:
6 * YOSHIFUJI Hideaki @USAGI
7 * Split up af-specific portion
8 *
9 */
10
11#include <linux/bottom_half.h>
12#include <linux/cache.h>
13#include <linux/interrupt.h>
14#include <linux/slab.h>
15#include <linux/module.h>
16#include <linux/netdevice.h>
17#include <linux/percpu.h>
18#include <net/dst.h>
19#include <net/ip.h>
20#include <net/xfrm.h>
21#include <net/ip_tunnels.h>
22#include <net/ip6_tunnel.h>
23#include <net/dst_metadata.h>
24#include <net/hotdata.h>
25
26#include "xfrm_inout.h"
27
28struct xfrm_trans_tasklet {
29 struct work_struct work;
30 spinlock_t queue_lock;
31 struct sk_buff_head queue;
32};
33
34struct xfrm_trans_cb {
35 union {
36 struct inet_skb_parm h4;
37#if IS_ENABLED(CONFIG_IPV6)
38 struct inet6_skb_parm h6;
39#endif
40 } header;
41 int (*finish)(struct net *net, struct sock *sk, struct sk_buff *skb);
42 struct net *net;
43};
44
45#define XFRM_TRANS_SKB_CB(__skb) ((struct xfrm_trans_cb *)&((__skb)->cb[0]))
46
47static DEFINE_SPINLOCK(xfrm_input_afinfo_lock);
48static struct xfrm_input_afinfo const __rcu *xfrm_input_afinfo[2][AF_INET6 + 1];
49
50static struct gro_cells gro_cells;
51static struct net_device xfrm_napi_dev;
52
53static DEFINE_PER_CPU(struct xfrm_trans_tasklet, xfrm_trans_tasklet);
54
55int xfrm_input_register_afinfo(const struct xfrm_input_afinfo *afinfo)
56{
57 int err = 0;
58
59 if (WARN_ON(afinfo->family > AF_INET6))
60 return -EAFNOSUPPORT;
61
62 spin_lock_bh(lock: &xfrm_input_afinfo_lock);
63 if (unlikely(xfrm_input_afinfo[afinfo->is_ipip][afinfo->family]))
64 err = -EEXIST;
65 else
66 rcu_assign_pointer(xfrm_input_afinfo[afinfo->is_ipip][afinfo->family], afinfo);
67 spin_unlock_bh(lock: &xfrm_input_afinfo_lock);
68 return err;
69}
70EXPORT_SYMBOL(xfrm_input_register_afinfo);
71
72int xfrm_input_unregister_afinfo(const struct xfrm_input_afinfo *afinfo)
73{
74 int err = 0;
75
76 spin_lock_bh(lock: &xfrm_input_afinfo_lock);
77 if (likely(xfrm_input_afinfo[afinfo->is_ipip][afinfo->family])) {
78 if (unlikely(xfrm_input_afinfo[afinfo->is_ipip][afinfo->family] != afinfo))
79 err = -EINVAL;
80 else
81 RCU_INIT_POINTER(xfrm_input_afinfo[afinfo->is_ipip][afinfo->family], NULL);
82 }
83 spin_unlock_bh(lock: &xfrm_input_afinfo_lock);
84 synchronize_rcu();
85 return err;
86}
87EXPORT_SYMBOL(xfrm_input_unregister_afinfo);
88
89static const struct xfrm_input_afinfo *xfrm_input_get_afinfo(u8 family, bool is_ipip)
90{
91 const struct xfrm_input_afinfo *afinfo;
92
93 if (WARN_ON_ONCE(family > AF_INET6))
94 return NULL;
95
96 rcu_read_lock();
97 afinfo = rcu_dereference(xfrm_input_afinfo[is_ipip][family]);
98 if (unlikely(!afinfo))
99 rcu_read_unlock();
100 return afinfo;
101}
102
103static int xfrm_rcv_cb(struct sk_buff *skb, unsigned int family, u8 protocol,
104 int err)
105{
106 bool is_ipip = (protocol == IPPROTO_IPIP || protocol == IPPROTO_IPV6);
107 const struct xfrm_input_afinfo *afinfo;
108 int ret;
109
110 afinfo = xfrm_input_get_afinfo(family, is_ipip);
111 if (!afinfo)
112 return -EAFNOSUPPORT;
113
114 ret = afinfo->callback(skb, protocol, err);
115 rcu_read_unlock();
116
117 return ret;
118}
119
120struct sec_path *secpath_set(struct sk_buff *skb)
121{
122 struct sec_path *sp, *tmp = skb_ext_find(skb, id: SKB_EXT_SEC_PATH);
123
124 sp = skb_ext_add(skb, id: SKB_EXT_SEC_PATH);
125 if (!sp)
126 return NULL;
127
128 if (tmp) /* reused existing one (was COW'd if needed) */
129 return sp;
130
131 /* allocated new secpath */
132 memset(sp->ovec, 0, sizeof(sp->ovec));
133 sp->olen = 0;
134 sp->len = 0;
135 sp->verified_cnt = 0;
136
137 return sp;
138}
139EXPORT_SYMBOL(secpath_set);
140
141/* Fetch spi and seq from ipsec header */
142
143int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq)
144{
145 int offset, offset_seq;
146 int hlen;
147
148 switch (nexthdr) {
149 case IPPROTO_AH:
150 hlen = sizeof(struct ip_auth_hdr);
151 offset = offsetof(struct ip_auth_hdr, spi);
152 offset_seq = offsetof(struct ip_auth_hdr, seq_no);
153 break;
154 case IPPROTO_ESP:
155 hlen = sizeof(struct ip_esp_hdr);
156 offset = offsetof(struct ip_esp_hdr, spi);
157 offset_seq = offsetof(struct ip_esp_hdr, seq_no);
158 break;
159 case IPPROTO_COMP:
160 if (!pskb_may_pull(skb, len: sizeof(struct ip_comp_hdr)))
161 return -EINVAL;
162 *spi = htonl(ntohs(*(__be16 *)(skb_transport_header(skb) + 2)));
163 *seq = 0;
164 return 0;
165 default:
166 return 1;
167 }
168
169 if (!pskb_may_pull(skb, len: hlen))
170 return -EINVAL;
171
172 *spi = *(__be32 *)(skb_transport_header(skb) + offset);
173 *seq = *(__be32 *)(skb_transport_header(skb) + offset_seq);
174 return 0;
175}
176EXPORT_SYMBOL(xfrm_parse_spi);
177
178static int xfrm4_remove_beet_encap(struct xfrm_state *x, struct sk_buff *skb)
179{
180 struct iphdr *iph;
181 int optlen = 0;
182 int err = -EINVAL;
183
184 skb->protocol = htons(ETH_P_IP);
185
186 if (unlikely(XFRM_MODE_SKB_CB(skb)->protocol == IPPROTO_BEETPH)) {
187 struct ip_beet_phdr *ph;
188 int phlen;
189
190 if (!pskb_may_pull(skb, len: sizeof(*ph)))
191 goto out;
192
193 ph = (struct ip_beet_phdr *)skb->data;
194
195 phlen = sizeof(*ph) + ph->padlen;
196 optlen = ph->hdrlen * 8 + (IPV4_BEET_PHMAXLEN - phlen);
197 if (optlen < 0 || optlen & 3 || optlen > 250)
198 goto out;
199
200 XFRM_MODE_SKB_CB(skb)->protocol = ph->nexthdr;
201
202 if (!pskb_may_pull(skb, len: phlen))
203 goto out;
204 __skb_pull(skb, len: phlen);
205 }
206
207 skb_push(skb, len: sizeof(*iph));
208 skb_reset_network_header(skb);
209 skb_mac_header_rebuild(skb);
210
211 xfrm4_beet_make_header(skb);
212
213 iph = ip_hdr(skb);
214
215 iph->ihl += optlen / 4;
216 iph->tot_len = htons(skb->len);
217 iph->daddr = x->sel.daddr.a4;
218 iph->saddr = x->sel.saddr.a4;
219 iph->check = 0;
220 iph->check = ip_fast_csum(iph: skb_network_header(skb), ihl: iph->ihl);
221 err = 0;
222out:
223 return err;
224}
225
226static void ipip_ecn_decapsulate(struct sk_buff *skb)
227{
228 struct iphdr *inner_iph = ipip_hdr(skb);
229
230 if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
231 IP_ECN_set_ce(iph: inner_iph);
232}
233
234static int xfrm4_remove_tunnel_encap(struct xfrm_state *x, struct sk_buff *skb)
235{
236 int err = -EINVAL;
237
238 skb->protocol = htons(ETH_P_IP);
239
240 if (!pskb_may_pull(skb, len: sizeof(struct iphdr)))
241 goto out;
242
243 err = skb_unclone(skb, GFP_ATOMIC);
244 if (err)
245 goto out;
246
247 if (x->props.flags & XFRM_STATE_DECAP_DSCP)
248 ipv4_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, inner: ipip_hdr(skb));
249 if (!(x->props.flags & XFRM_STATE_NOECN))
250 ipip_ecn_decapsulate(skb);
251
252 skb_reset_network_header(skb);
253 skb_mac_header_rebuild(skb);
254 if (skb->mac_len)
255 eth_hdr(skb)->h_proto = skb->protocol;
256
257 err = 0;
258
259out:
260 return err;
261}
262
263static void ipip6_ecn_decapsulate(struct sk_buff *skb)
264{
265 struct ipv6hdr *inner_iph = ipipv6_hdr(skb);
266
267 if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
268 IP6_ECN_set_ce(skb, iph: inner_iph);
269}
270
271static int xfrm6_remove_tunnel_encap(struct xfrm_state *x, struct sk_buff *skb)
272{
273 int err = -EINVAL;
274
275 skb->protocol = htons(ETH_P_IPV6);
276
277 if (!pskb_may_pull(skb, len: sizeof(struct ipv6hdr)))
278 goto out;
279
280 err = skb_unclone(skb, GFP_ATOMIC);
281 if (err)
282 goto out;
283
284 if (x->props.flags & XFRM_STATE_DECAP_DSCP)
285 ipv6_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, inner: ipipv6_hdr(skb));
286 if (!(x->props.flags & XFRM_STATE_NOECN))
287 ipip6_ecn_decapsulate(skb);
288
289 skb_reset_network_header(skb);
290 skb_mac_header_rebuild(skb);
291 if (skb->mac_len)
292 eth_hdr(skb)->h_proto = skb->protocol;
293
294 err = 0;
295
296out:
297 return err;
298}
299
300static int xfrm6_remove_beet_encap(struct xfrm_state *x, struct sk_buff *skb)
301{
302 struct ipv6hdr *ip6h;
303 int size = sizeof(struct ipv6hdr);
304 int err;
305
306 skb->protocol = htons(ETH_P_IPV6);
307
308 err = skb_cow_head(skb, headroom: size + skb->mac_len);
309 if (err)
310 goto out;
311
312 __skb_push(skb, len: size);
313 skb_reset_network_header(skb);
314 skb_mac_header_rebuild(skb);
315
316 xfrm6_beet_make_header(skb);
317
318 ip6h = ipv6_hdr(skb);
319 ip6h->payload_len = htons(skb->len - size);
320 ip6h->daddr = x->sel.daddr.in6;
321 ip6h->saddr = x->sel.saddr.in6;
322 err = 0;
323out:
324 return err;
325}
326
327/* Remove encapsulation header.
328 *
329 * The IP header will be moved over the top of the encapsulation
330 * header.
331 *
332 * On entry, the transport header shall point to where the IP header
333 * should be and the network header shall be set to where the IP
334 * header currently is. skb->data shall point to the start of the
335 * payload.
336 */
337static int
338xfrm_inner_mode_encap_remove(struct xfrm_state *x,
339 struct sk_buff *skb)
340{
341 switch (x->props.mode) {
342 case XFRM_MODE_BEET:
343 switch (x->sel.family) {
344 case AF_INET:
345 return xfrm4_remove_beet_encap(x, skb);
346 case AF_INET6:
347 return xfrm6_remove_beet_encap(x, skb);
348 }
349 break;
350 case XFRM_MODE_TUNNEL:
351 switch (XFRM_MODE_SKB_CB(skb)->protocol) {
352 case IPPROTO_IPIP:
353 return xfrm4_remove_tunnel_encap(x, skb);
354 case IPPROTO_IPV6:
355 return xfrm6_remove_tunnel_encap(x, skb);
356 break;
357 }
358 return -EINVAL;
359 }
360
361 WARN_ON_ONCE(1);
362 return -EOPNOTSUPP;
363}
364
365static int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb)
366{
367 switch (x->props.family) {
368 case AF_INET:
369 xfrm4_extract_header(skb);
370 break;
371 case AF_INET6:
372 xfrm6_extract_header(skb);
373 break;
374 default:
375 WARN_ON_ONCE(1);
376 return -EAFNOSUPPORT;
377 }
378
379 return xfrm_inner_mode_encap_remove(x, skb);
380}
381
382/* Remove encapsulation header.
383 *
384 * The IP header will be moved over the top of the encapsulation header.
385 *
386 * On entry, skb_transport_header() shall point to where the IP header
387 * should be and skb_network_header() shall be set to where the IP header
388 * currently is. skb->data shall point to the start of the payload.
389 */
390static int xfrm4_transport_input(struct xfrm_state *x, struct sk_buff *skb)
391{
392 int ihl = skb->data - skb_transport_header(skb);
393
394 if (skb->transport_header != skb->network_header) {
395 memmove(skb_transport_header(skb),
396 skb_network_header(skb), ihl);
397 skb->network_header = skb->transport_header;
398 }
399 ip_hdr(skb)->tot_len = htons(skb->len + ihl);
400 skb_reset_transport_header(skb);
401 return 0;
402}
403
404static int xfrm6_transport_input(struct xfrm_state *x, struct sk_buff *skb)
405{
406#if IS_ENABLED(CONFIG_IPV6)
407 int ihl = skb->data - skb_transport_header(skb);
408
409 if (skb->transport_header != skb->network_header) {
410 memmove(skb_transport_header(skb),
411 skb_network_header(skb), ihl);
412 skb->network_header = skb->transport_header;
413 }
414 ipv6_hdr(skb)->payload_len = htons(skb->len + ihl -
415 sizeof(struct ipv6hdr));
416 skb_reset_transport_header(skb);
417 return 0;
418#else
419 WARN_ON_ONCE(1);
420 return -EAFNOSUPPORT;
421#endif
422}
423
424static int xfrm_inner_mode_input(struct xfrm_state *x,
425 struct sk_buff *skb)
426{
427 switch (x->props.mode) {
428 case XFRM_MODE_BEET:
429 case XFRM_MODE_TUNNEL:
430 return xfrm_prepare_input(x, skb);
431 case XFRM_MODE_TRANSPORT:
432 if (x->props.family == AF_INET)
433 return xfrm4_transport_input(x, skb);
434 if (x->props.family == AF_INET6)
435 return xfrm6_transport_input(x, skb);
436 break;
437 case XFRM_MODE_ROUTEOPTIMIZATION:
438 WARN_ON_ONCE(1);
439 break;
440 default:
441 WARN_ON_ONCE(1);
442 break;
443 }
444
445 return -EOPNOTSUPP;
446}
447
448int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
449{
450 const struct xfrm_state_afinfo *afinfo;
451 struct net *net = dev_net(dev: skb->dev);
452 int err;
453 __be32 seq;
454 __be32 seq_hi;
455 struct xfrm_state *x = NULL;
456 xfrm_address_t *daddr;
457 u32 mark = skb->mark;
458 unsigned int family = AF_UNSPEC;
459 int decaps = 0;
460 int async = 0;
461 bool xfrm_gro = false;
462 bool crypto_done = false;
463 struct xfrm_offload *xo = xfrm_offload(skb);
464 struct sec_path *sp;
465
466 if (encap_type < 0 || (xo && xo->flags & XFRM_GRO)) {
467 x = xfrm_input_state(skb);
468
469 if (unlikely(x->km.state != XFRM_STATE_VALID)) {
470 if (x->km.state == XFRM_STATE_ACQ)
471 XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR);
472 else
473 XFRM_INC_STATS(net,
474 LINUX_MIB_XFRMINSTATEINVALID);
475
476 if (encap_type == -1)
477 dev_put(dev: skb->dev);
478 goto drop;
479 }
480
481 family = x->props.family;
482
483 /* An encap_type of -1 indicates async resumption. */
484 if (encap_type == -1) {
485 async = 1;
486 seq = XFRM_SKB_CB(skb)->seq.input.low;
487 goto resume;
488 }
489 /* GRO call */
490 seq = XFRM_SPI_SKB_CB(skb)->seq;
491
492 if (xo && (xo->flags & CRYPTO_DONE)) {
493 crypto_done = true;
494 family = XFRM_SPI_SKB_CB(skb)->family;
495
496 if (!(xo->status & CRYPTO_SUCCESS)) {
497 if (xo->status &
498 (CRYPTO_TRANSPORT_AH_AUTH_FAILED |
499 CRYPTO_TRANSPORT_ESP_AUTH_FAILED |
500 CRYPTO_TUNNEL_AH_AUTH_FAILED |
501 CRYPTO_TUNNEL_ESP_AUTH_FAILED)) {
502
503 xfrm_audit_state_icvfail(x, skb,
504 proto: x->type->proto);
505 x->stats.integrity_failed++;
506 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
507 goto drop;
508 }
509
510 if (xo->status & CRYPTO_INVALID_PROTOCOL) {
511 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
512 goto drop;
513 }
514
515 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
516 goto drop;
517 }
518
519 if (xfrm_parse_spi(skb, nexthdr, &spi, &seq)) {
520 XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
521 goto drop;
522 }
523 }
524
525 goto lock;
526 }
527
528 family = XFRM_SPI_SKB_CB(skb)->family;
529
530 /* if tunnel is present override skb->mark value with tunnel i_key */
531 switch (family) {
532 case AF_INET:
533 if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4)
534 mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4->parms.i_key);
535 break;
536 case AF_INET6:
537 if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6)
538 mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6->parms.i_key);
539 break;
540 }
541
542 sp = secpath_set(skb);
543 if (!sp) {
544 XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
545 goto drop;
546 }
547
548 seq = 0;
549 if (!spi && xfrm_parse_spi(skb, nexthdr, &spi, &seq)) {
550 secpath_reset(skb);
551 XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
552 goto drop;
553 }
554
555 daddr = (xfrm_address_t *)(skb_network_header(skb) +
556 XFRM_SPI_SKB_CB(skb)->daddroff);
557 do {
558 sp = skb_sec_path(skb);
559
560 if (sp->len == XFRM_MAX_DEPTH) {
561 secpath_reset(skb);
562 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
563 goto drop;
564 }
565
566 x = xfrm_state_lookup(net, mark, daddr, spi, proto: nexthdr, family);
567 if (x == NULL) {
568 secpath_reset(skb);
569 XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
570 xfrm_audit_state_notfound(skb, family, net_spi: spi, net_seq: seq);
571 goto drop;
572 }
573
574 skb->mark = xfrm_smark_get(mark: skb->mark, x);
575
576 sp->xvec[sp->len++] = x;
577
578 skb_dst_force(skb);
579 if (!skb_dst(skb)) {
580 XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
581 goto drop;
582 }
583
584lock:
585 spin_lock(lock: &x->lock);
586
587 if (unlikely(x->km.state != XFRM_STATE_VALID)) {
588 if (x->km.state == XFRM_STATE_ACQ)
589 XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR);
590 else
591 XFRM_INC_STATS(net,
592 LINUX_MIB_XFRMINSTATEINVALID);
593 goto drop_unlock;
594 }
595
596 if ((x->encap ? x->encap->encap_type : 0) != encap_type) {
597 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
598 goto drop_unlock;
599 }
600
601 if (xfrm_replay_check(x, skb, net_seq: seq)) {
602 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
603 goto drop_unlock;
604 }
605
606 if (xfrm_state_check_expire(x)) {
607 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEEXPIRED);
608 goto drop_unlock;
609 }
610
611 spin_unlock(lock: &x->lock);
612
613 if (xfrm_tunnel_check(skb, x, family)) {
614 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
615 goto drop;
616 }
617
618 seq_hi = htonl(xfrm_replay_seqhi(x, seq));
619
620 XFRM_SKB_CB(skb)->seq.input.low = seq;
621 XFRM_SKB_CB(skb)->seq.input.hi = seq_hi;
622
623 dev_hold(dev: skb->dev);
624
625 if (crypto_done)
626 nexthdr = x->type_offload->input_tail(x, skb);
627 else
628 nexthdr = x->type->input(x, skb);
629
630 if (nexthdr == -EINPROGRESS)
631 return 0;
632resume:
633 dev_put(dev: skb->dev);
634
635 spin_lock(lock: &x->lock);
636 if (nexthdr < 0) {
637 if (nexthdr == -EBADMSG) {
638 xfrm_audit_state_icvfail(x, skb,
639 proto: x->type->proto);
640 x->stats.integrity_failed++;
641 }
642 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
643 goto drop_unlock;
644 }
645
646 /* only the first xfrm gets the encap type */
647 encap_type = 0;
648
649 if (xfrm_replay_recheck(x, skb, net_seq: seq)) {
650 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
651 goto drop_unlock;
652 }
653
654 xfrm_replay_advance(x, net_seq: seq);
655
656 x->curlft.bytes += skb->len;
657 x->curlft.packets++;
658 x->lastused = ktime_get_real_seconds();
659
660 spin_unlock(lock: &x->lock);
661
662 XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;
663
664 if (xfrm_inner_mode_input(x, skb)) {
665 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
666 goto drop;
667 }
668
669 if (x->outer_mode.flags & XFRM_MODE_FLAG_TUNNEL) {
670 decaps = 1;
671 break;
672 }
673
674 /*
675 * We need the inner address. However, we only get here for
676 * transport mode so the outer address is identical.
677 */
678 daddr = &x->id.daddr;
679 family = x->props.family;
680
681 err = xfrm_parse_spi(skb, nexthdr, &spi, &seq);
682 if (err < 0) {
683 XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
684 goto drop;
685 }
686 crypto_done = false;
687 } while (!err);
688
689 err = xfrm_rcv_cb(skb, family, protocol: x->type->proto, err: 0);
690 if (err)
691 goto drop;
692
693 nf_reset_ct(skb);
694
695 if (decaps) {
696 sp = skb_sec_path(skb);
697 if (sp)
698 sp->olen = 0;
699 if (skb_valid_dst(skb))
700 skb_dst_drop(skb);
701 gro_cells_receive(gcells: &gro_cells, skb);
702 return 0;
703 } else {
704 xo = xfrm_offload(skb);
705 if (xo)
706 xfrm_gro = xo->flags & XFRM_GRO;
707
708 err = -EAFNOSUPPORT;
709 rcu_read_lock();
710 afinfo = xfrm_state_afinfo_get_rcu(family: x->props.family);
711 if (likely(afinfo))
712 err = afinfo->transport_finish(skb, xfrm_gro || async);
713 rcu_read_unlock();
714 if (xfrm_gro) {
715 sp = skb_sec_path(skb);
716 if (sp)
717 sp->olen = 0;
718 if (skb_valid_dst(skb))
719 skb_dst_drop(skb);
720 gro_cells_receive(gcells: &gro_cells, skb);
721 return err;
722 }
723
724 return err;
725 }
726
727drop_unlock:
728 spin_unlock(lock: &x->lock);
729drop:
730 xfrm_rcv_cb(skb, family, protocol: x && x->type ? x->type->proto : nexthdr, err: -1);
731 kfree_skb(skb);
732 return 0;
733}
734EXPORT_SYMBOL(xfrm_input);
735
736int xfrm_input_resume(struct sk_buff *skb, int nexthdr)
737{
738 return xfrm_input(skb, nexthdr, 0, -1);
739}
740EXPORT_SYMBOL(xfrm_input_resume);
741
742static void xfrm_trans_reinject(struct work_struct *work)
743{
744 struct xfrm_trans_tasklet *trans = container_of(work, struct xfrm_trans_tasklet, work);
745 struct sk_buff_head queue;
746 struct sk_buff *skb;
747
748 __skb_queue_head_init(list: &queue);
749 spin_lock_bh(lock: &trans->queue_lock);
750 skb_queue_splice_init(list: &trans->queue, head: &queue);
751 spin_unlock_bh(lock: &trans->queue_lock);
752
753 local_bh_disable();
754 while ((skb = __skb_dequeue(list: &queue)))
755 XFRM_TRANS_SKB_CB(skb)->finish(XFRM_TRANS_SKB_CB(skb)->net,
756 NULL, skb);
757 local_bh_enable();
758}
759
760int xfrm_trans_queue_net(struct net *net, struct sk_buff *skb,
761 int (*finish)(struct net *, struct sock *,
762 struct sk_buff *))
763{
764 struct xfrm_trans_tasklet *trans;
765
766 trans = this_cpu_ptr(&xfrm_trans_tasklet);
767
768 if (skb_queue_len(list_: &trans->queue) >= READ_ONCE(net_hotdata.max_backlog))
769 return -ENOBUFS;
770
771 BUILD_BUG_ON(sizeof(struct xfrm_trans_cb) > sizeof(skb->cb));
772
773 XFRM_TRANS_SKB_CB(skb)->finish = finish;
774 XFRM_TRANS_SKB_CB(skb)->net = net;
775 spin_lock_bh(lock: &trans->queue_lock);
776 __skb_queue_tail(list: &trans->queue, newsk: skb);
777 spin_unlock_bh(lock: &trans->queue_lock);
778 schedule_work(work: &trans->work);
779 return 0;
780}
781EXPORT_SYMBOL(xfrm_trans_queue_net);
782
783int xfrm_trans_queue(struct sk_buff *skb,
784 int (*finish)(struct net *, struct sock *,
785 struct sk_buff *))
786{
787 return xfrm_trans_queue_net(dev_net(dev: skb->dev), skb, finish);
788}
789EXPORT_SYMBOL(xfrm_trans_queue);
790
791void __init xfrm_input_init(void)
792{
793 int err;
794 int i;
795
796 init_dummy_netdev(dev: &xfrm_napi_dev);
797 err = gro_cells_init(gcells: &gro_cells, dev: &xfrm_napi_dev);
798 if (err)
799 gro_cells.cells = NULL;
800
801 for_each_possible_cpu(i) {
802 struct xfrm_trans_tasklet *trans;
803
804 trans = &per_cpu(xfrm_trans_tasklet, i);
805 spin_lock_init(&trans->queue_lock);
806 __skb_queue_head_init(list: &trans->queue);
807 INIT_WORK(&trans->work, xfrm_trans_reinject);
808 }
809}
810

source code of linux/net/xfrm/xfrm_input.c