xref: /linux/net/xfrm/xfrm_input.c (revision 9cf621bd5fcbeadc2804951d13d487e22e95b363)
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 
28 struct xfrm_trans_tasklet {
29 	struct work_struct work;
30 	spinlock_t queue_lock;
31 	struct sk_buff_head queue;
32 };
33 
34 struct 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 
47 static DEFINE_SPINLOCK(xfrm_input_afinfo_lock);
48 static struct xfrm_input_afinfo const __rcu *xfrm_input_afinfo[2][AF_INET6 + 1];
49 
50 static struct gro_cells gro_cells;
51 static struct net_device xfrm_napi_dev;
52 
53 static DEFINE_PER_CPU(struct xfrm_trans_tasklet, xfrm_trans_tasklet);
54 
55 int 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(&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(&xfrm_input_afinfo_lock);
68 	return err;
69 }
70 EXPORT_SYMBOL(xfrm_input_register_afinfo);
71 
72 int xfrm_input_unregister_afinfo(const struct xfrm_input_afinfo *afinfo)
73 {
74 	int err = 0;
75 
76 	spin_lock_bh(&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(&xfrm_input_afinfo_lock);
84 	synchronize_rcu();
85 	return err;
86 }
87 EXPORT_SYMBOL(xfrm_input_unregister_afinfo);
88 
89 static 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 
103 static 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 
120 struct sec_path *secpath_set(struct sk_buff *skb)
121 {
122 	struct sec_path *sp, *tmp = skb_ext_find(skb, SKB_EXT_SEC_PATH);
123 
124 	sp = skb_ext_add(skb, 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 }
139 EXPORT_SYMBOL(secpath_set);
140 
141 /* Fetch spi and seq from ipsec header */
142 
143 int 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, 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, 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 }
176 EXPORT_SYMBOL(xfrm_parse_spi);
177 
178 static 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, 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, phlen))
203 			goto out;
204 		__skb_pull(skb, phlen);
205 	}
206 
207 	skb_push(skb, 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(skb_network_header(skb), iph->ihl);
221 	err = 0;
222 out:
223 	return err;
224 }
225 
226 static 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(inner_iph);
232 }
233 
234 static 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, 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, 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 
259 out:
260 	return err;
261 }
262 
263 static 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, inner_iph);
269 }
270 
271 static 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, 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, 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 
296 out:
297 	return err;
298 }
299 
300 static 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, size + skb->mac_len);
309 	if (err)
310 		goto out;
311 
312 	__skb_push(skb, 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;
323 out:
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  */
337 static int
338 xfrm_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 
365 static 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  */
390 static 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 
404 static 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 
424 static 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 
448 int 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(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->dir && x->dir != XFRM_SA_DIR_IN)) {
470 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEDIRERROR);
471 			goto drop;
472 		}
473 
474 		if (unlikely(x->km.state != XFRM_STATE_VALID)) {
475 			if (x->km.state == XFRM_STATE_ACQ)
476 				XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR);
477 			else
478 				XFRM_INC_STATS(net,
479 					       LINUX_MIB_XFRMINSTATEINVALID);
480 
481 			if (encap_type == -1)
482 				dev_put(skb->dev);
483 			goto drop;
484 		}
485 
486 		family = x->props.family;
487 
488 		/* An encap_type of -1 indicates async resumption. */
489 		if (encap_type == -1) {
490 			async = 1;
491 			seq = XFRM_SKB_CB(skb)->seq.input.low;
492 			goto resume;
493 		}
494 		/* GRO call */
495 		seq = XFRM_SPI_SKB_CB(skb)->seq;
496 
497 		if (xo && (xo->flags & CRYPTO_DONE)) {
498 			crypto_done = true;
499 			family = XFRM_SPI_SKB_CB(skb)->family;
500 
501 			if (!(xo->status & CRYPTO_SUCCESS)) {
502 				if (xo->status &
503 				    (CRYPTO_TRANSPORT_AH_AUTH_FAILED |
504 				     CRYPTO_TRANSPORT_ESP_AUTH_FAILED |
505 				     CRYPTO_TUNNEL_AH_AUTH_FAILED |
506 				     CRYPTO_TUNNEL_ESP_AUTH_FAILED)) {
507 
508 					xfrm_audit_state_icvfail(x, skb,
509 								 x->type->proto);
510 					x->stats.integrity_failed++;
511 					XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
512 					goto drop;
513 				}
514 
515 				if (xo->status & CRYPTO_INVALID_PROTOCOL) {
516 					XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
517 					goto drop;
518 				}
519 
520 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
521 				goto drop;
522 			}
523 
524 			if (xfrm_parse_spi(skb, nexthdr, &spi, &seq)) {
525 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
526 				goto drop;
527 			}
528 		}
529 
530 		goto lock;
531 	}
532 
533 	family = XFRM_SPI_SKB_CB(skb)->family;
534 
535 	/* if tunnel is present override skb->mark value with tunnel i_key */
536 	switch (family) {
537 	case AF_INET:
538 		if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4)
539 			mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4->parms.i_key);
540 		break;
541 	case AF_INET6:
542 		if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6)
543 			mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6->parms.i_key);
544 		break;
545 	}
546 
547 	sp = secpath_set(skb);
548 	if (!sp) {
549 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
550 		goto drop;
551 	}
552 
553 	seq = 0;
554 	if (!spi && xfrm_parse_spi(skb, nexthdr, &spi, &seq)) {
555 		secpath_reset(skb);
556 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
557 		goto drop;
558 	}
559 
560 	daddr = (xfrm_address_t *)(skb_network_header(skb) +
561 				   XFRM_SPI_SKB_CB(skb)->daddroff);
562 	do {
563 		sp = skb_sec_path(skb);
564 
565 		if (sp->len == XFRM_MAX_DEPTH) {
566 			secpath_reset(skb);
567 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
568 			goto drop;
569 		}
570 
571 		x = xfrm_state_lookup(net, mark, daddr, spi, nexthdr, family);
572 		if (x == NULL) {
573 			secpath_reset(skb);
574 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
575 			xfrm_audit_state_notfound(skb, family, spi, seq);
576 			goto drop;
577 		}
578 
579 		if (unlikely(x->dir && x->dir != XFRM_SA_DIR_IN)) {
580 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEDIRERROR);
581 			xfrm_state_put(x);
582 			goto drop;
583 		}
584 
585 		skb->mark = xfrm_smark_get(skb->mark, x);
586 
587 		sp->xvec[sp->len++] = x;
588 
589 		skb_dst_force(skb);
590 		if (!skb_dst(skb)) {
591 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
592 			goto drop;
593 		}
594 
595 lock:
596 		spin_lock(&x->lock);
597 
598 		if (unlikely(x->km.state != XFRM_STATE_VALID)) {
599 			if (x->km.state == XFRM_STATE_ACQ)
600 				XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR);
601 			else
602 				XFRM_INC_STATS(net,
603 					       LINUX_MIB_XFRMINSTATEINVALID);
604 			goto drop_unlock;
605 		}
606 
607 		if ((x->encap ? x->encap->encap_type : 0) != encap_type) {
608 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
609 			goto drop_unlock;
610 		}
611 
612 		if (xfrm_replay_check(x, skb, seq)) {
613 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
614 			goto drop_unlock;
615 		}
616 
617 		if (xfrm_state_check_expire(x)) {
618 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEEXPIRED);
619 			goto drop_unlock;
620 		}
621 
622 		spin_unlock(&x->lock);
623 
624 		if (xfrm_tunnel_check(skb, x, family)) {
625 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
626 			goto drop;
627 		}
628 
629 		seq_hi = htonl(xfrm_replay_seqhi(x, seq));
630 
631 		XFRM_SKB_CB(skb)->seq.input.low = seq;
632 		XFRM_SKB_CB(skb)->seq.input.hi = seq_hi;
633 
634 		dev_hold(skb->dev);
635 
636 		if (crypto_done)
637 			nexthdr = x->type_offload->input_tail(x, skb);
638 		else
639 			nexthdr = x->type->input(x, skb);
640 
641 		if (nexthdr == -EINPROGRESS)
642 			return 0;
643 resume:
644 		dev_put(skb->dev);
645 
646 		spin_lock(&x->lock);
647 		if (nexthdr < 0) {
648 			if (nexthdr == -EBADMSG) {
649 				xfrm_audit_state_icvfail(x, skb,
650 							 x->type->proto);
651 				x->stats.integrity_failed++;
652 			}
653 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
654 			goto drop_unlock;
655 		}
656 
657 		/* only the first xfrm gets the encap type */
658 		encap_type = 0;
659 
660 		if (xfrm_replay_recheck(x, skb, seq)) {
661 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
662 			goto drop_unlock;
663 		}
664 
665 		xfrm_replay_advance(x, seq);
666 
667 		x->curlft.bytes += skb->len;
668 		x->curlft.packets++;
669 		x->lastused = ktime_get_real_seconds();
670 
671 		spin_unlock(&x->lock);
672 
673 		XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;
674 
675 		if (xfrm_inner_mode_input(x, skb)) {
676 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
677 			goto drop;
678 		}
679 
680 		if (x->outer_mode.flags & XFRM_MODE_FLAG_TUNNEL) {
681 			decaps = 1;
682 			break;
683 		}
684 
685 		/*
686 		 * We need the inner address.  However, we only get here for
687 		 * transport mode so the outer address is identical.
688 		 */
689 		daddr = &x->id.daddr;
690 		family = x->props.family;
691 
692 		err = xfrm_parse_spi(skb, nexthdr, &spi, &seq);
693 		if (err < 0) {
694 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
695 			goto drop;
696 		}
697 		crypto_done = false;
698 	} while (!err);
699 
700 	err = xfrm_rcv_cb(skb, family, x->type->proto, 0);
701 	if (err)
702 		goto drop;
703 
704 	nf_reset_ct(skb);
705 
706 	if (decaps) {
707 		sp = skb_sec_path(skb);
708 		if (sp)
709 			sp->olen = 0;
710 		if (skb_valid_dst(skb))
711 			skb_dst_drop(skb);
712 		gro_cells_receive(&gro_cells, skb);
713 		return 0;
714 	} else {
715 		xo = xfrm_offload(skb);
716 		if (xo)
717 			xfrm_gro = xo->flags & XFRM_GRO;
718 
719 		err = -EAFNOSUPPORT;
720 		rcu_read_lock();
721 		afinfo = xfrm_state_afinfo_get_rcu(x->props.family);
722 		if (likely(afinfo))
723 			err = afinfo->transport_finish(skb, xfrm_gro || async);
724 		rcu_read_unlock();
725 		if (xfrm_gro) {
726 			sp = skb_sec_path(skb);
727 			if (sp)
728 				sp->olen = 0;
729 			if (skb_valid_dst(skb))
730 				skb_dst_drop(skb);
731 			gro_cells_receive(&gro_cells, skb);
732 			return err;
733 		}
734 
735 		return err;
736 	}
737 
738 drop_unlock:
739 	spin_unlock(&x->lock);
740 drop:
741 	xfrm_rcv_cb(skb, family, x && x->type ? x->type->proto : nexthdr, -1);
742 	kfree_skb(skb);
743 	return 0;
744 }
745 EXPORT_SYMBOL(xfrm_input);
746 
747 int xfrm_input_resume(struct sk_buff *skb, int nexthdr)
748 {
749 	return xfrm_input(skb, nexthdr, 0, -1);
750 }
751 EXPORT_SYMBOL(xfrm_input_resume);
752 
753 static void xfrm_trans_reinject(struct work_struct *work)
754 {
755 	struct xfrm_trans_tasklet *trans = container_of(work, struct xfrm_trans_tasklet, work);
756 	struct sk_buff_head queue;
757 	struct sk_buff *skb;
758 
759 	__skb_queue_head_init(&queue);
760 	spin_lock_bh(&trans->queue_lock);
761 	skb_queue_splice_init(&trans->queue, &queue);
762 	spin_unlock_bh(&trans->queue_lock);
763 
764 	local_bh_disable();
765 	while ((skb = __skb_dequeue(&queue)))
766 		XFRM_TRANS_SKB_CB(skb)->finish(XFRM_TRANS_SKB_CB(skb)->net,
767 					       NULL, skb);
768 	local_bh_enable();
769 }
770 
771 int xfrm_trans_queue_net(struct net *net, struct sk_buff *skb,
772 			 int (*finish)(struct net *, struct sock *,
773 				       struct sk_buff *))
774 {
775 	struct xfrm_trans_tasklet *trans;
776 
777 	trans = this_cpu_ptr(&xfrm_trans_tasklet);
778 
779 	if (skb_queue_len(&trans->queue) >= READ_ONCE(net_hotdata.max_backlog))
780 		return -ENOBUFS;
781 
782 	BUILD_BUG_ON(sizeof(struct xfrm_trans_cb) > sizeof(skb->cb));
783 
784 	XFRM_TRANS_SKB_CB(skb)->finish = finish;
785 	XFRM_TRANS_SKB_CB(skb)->net = net;
786 	spin_lock_bh(&trans->queue_lock);
787 	__skb_queue_tail(&trans->queue, skb);
788 	spin_unlock_bh(&trans->queue_lock);
789 	schedule_work(&trans->work);
790 	return 0;
791 }
792 EXPORT_SYMBOL(xfrm_trans_queue_net);
793 
794 int xfrm_trans_queue(struct sk_buff *skb,
795 		     int (*finish)(struct net *, struct sock *,
796 				   struct sk_buff *))
797 {
798 	return xfrm_trans_queue_net(dev_net(skb->dev), skb, finish);
799 }
800 EXPORT_SYMBOL(xfrm_trans_queue);
801 
802 void __init xfrm_input_init(void)
803 {
804 	int err;
805 	int i;
806 
807 	init_dummy_netdev(&xfrm_napi_dev);
808 	err = gro_cells_init(&gro_cells, &xfrm_napi_dev);
809 	if (err)
810 		gro_cells.cells = NULL;
811 
812 	for_each_possible_cpu(i) {
813 		struct xfrm_trans_tasklet *trans;
814 
815 		trans = &per_cpu(xfrm_trans_tasklet, i);
816 		spin_lock_init(&trans->queue_lock);
817 		__skb_queue_head_init(&trans->queue);
818 		INIT_WORK(&trans->work, xfrm_trans_reinject);
819 	}
820 }
821