xref: /linux/net/xfrm/xfrm_input.c (revision 103b4f5b4007cb484f40b1c8095a7e0526e5aff6)
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 		const struct xfrm_input_afinfo *cur;
79 
80 		cur = rcu_access_pointer(xfrm_input_afinfo[afinfo->is_ipip][afinfo->family]);
81 		if (unlikely(cur != afinfo))
82 			err = -EINVAL;
83 		else
84 			RCU_INIT_POINTER(xfrm_input_afinfo[afinfo->is_ipip][afinfo->family], NULL);
85 	}
86 	spin_unlock_bh(&xfrm_input_afinfo_lock);
87 	synchronize_rcu();
88 	return err;
89 }
90 EXPORT_SYMBOL(xfrm_input_unregister_afinfo);
91 
92 static const struct xfrm_input_afinfo *xfrm_input_get_afinfo(u8 family, bool is_ipip)
93 {
94 	const struct xfrm_input_afinfo *afinfo;
95 
96 	if (WARN_ON_ONCE(family > AF_INET6))
97 		return NULL;
98 
99 	rcu_read_lock();
100 	afinfo = rcu_dereference(xfrm_input_afinfo[is_ipip][family]);
101 	if (unlikely(!afinfo))
102 		rcu_read_unlock();
103 	return afinfo;
104 }
105 
106 static int xfrm_rcv_cb(struct sk_buff *skb, unsigned int family, u8 protocol,
107 		       int err)
108 {
109 	bool is_ipip = (protocol == IPPROTO_IPIP || protocol == IPPROTO_IPV6);
110 	const struct xfrm_input_afinfo *afinfo;
111 	int ret;
112 
113 	afinfo = xfrm_input_get_afinfo(family, is_ipip);
114 	if (!afinfo)
115 		return -EAFNOSUPPORT;
116 
117 	ret = afinfo->callback(skb, protocol, err);
118 	rcu_read_unlock();
119 
120 	return ret;
121 }
122 
123 struct sec_path *secpath_set(struct sk_buff *skb)
124 {
125 	struct sec_path *sp, *tmp = skb_ext_find(skb, SKB_EXT_SEC_PATH);
126 
127 	sp = skb_ext_add(skb, SKB_EXT_SEC_PATH);
128 	if (!sp)
129 		return NULL;
130 
131 	if (tmp) /* reused existing one (was COW'd if needed) */
132 		return sp;
133 
134 	/* allocated new secpath */
135 	memset(sp->ovec, 0, sizeof(sp->ovec));
136 	sp->olen = 0;
137 	sp->len = 0;
138 	sp->verified_cnt = 0;
139 
140 	return sp;
141 }
142 EXPORT_SYMBOL(secpath_set);
143 
144 /* Fetch spi and seq from ipsec header */
145 
146 int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq)
147 {
148 	int offset, offset_seq;
149 	int hlen;
150 
151 	switch (nexthdr) {
152 	case IPPROTO_AH:
153 		hlen = sizeof(struct ip_auth_hdr);
154 		offset = offsetof(struct ip_auth_hdr, spi);
155 		offset_seq = offsetof(struct ip_auth_hdr, seq_no);
156 		break;
157 	case IPPROTO_ESP:
158 		hlen = sizeof(struct ip_esp_hdr);
159 		offset = offsetof(struct ip_esp_hdr, spi);
160 		offset_seq = offsetof(struct ip_esp_hdr, seq_no);
161 		break;
162 	case IPPROTO_COMP:
163 		if (!pskb_may_pull(skb, sizeof(struct ip_comp_hdr)))
164 			return -EINVAL;
165 		*spi = htonl(ntohs(*(__be16 *)(skb_transport_header(skb) + 2)));
166 		*seq = 0;
167 		return 0;
168 	default:
169 		return 1;
170 	}
171 
172 	if (!pskb_may_pull(skb, hlen))
173 		return -EINVAL;
174 
175 	*spi = *(__be32 *)(skb_transport_header(skb) + offset);
176 	*seq = *(__be32 *)(skb_transport_header(skb) + offset_seq);
177 	return 0;
178 }
179 EXPORT_SYMBOL(xfrm_parse_spi);
180 
181 static int xfrm4_remove_beet_encap(struct xfrm_state *x, struct sk_buff *skb)
182 {
183 	struct iphdr *iph;
184 	int optlen = 0;
185 	int err = -EINVAL;
186 
187 	skb->protocol = htons(ETH_P_IP);
188 
189 	if (unlikely(XFRM_MODE_SKB_CB(skb)->protocol == IPPROTO_BEETPH)) {
190 		struct ip_beet_phdr *ph;
191 		int phlen;
192 
193 		if (!pskb_may_pull(skb, sizeof(*ph)))
194 			goto out;
195 
196 		ph = (struct ip_beet_phdr *)skb->data;
197 
198 		phlen = sizeof(*ph) + ph->padlen;
199 		optlen = ph->hdrlen * 8 + (IPV4_BEET_PHMAXLEN - phlen);
200 		if (optlen < 0 || optlen & 3 || optlen > 250)
201 			goto out;
202 
203 		XFRM_MODE_SKB_CB(skb)->protocol = ph->nexthdr;
204 
205 		if (!pskb_may_pull(skb, phlen))
206 			goto out;
207 		__skb_pull(skb, phlen);
208 	}
209 
210 	skb_push(skb, sizeof(*iph));
211 	skb_reset_network_header(skb);
212 	skb_mac_header_rebuild(skb);
213 
214 	xfrm4_beet_make_header(skb);
215 
216 	iph = ip_hdr(skb);
217 
218 	iph->ihl += optlen / 4;
219 	iph->tot_len = htons(skb->len);
220 	iph->daddr = x->sel.daddr.a4;
221 	iph->saddr = x->sel.saddr.a4;
222 	iph->check = 0;
223 	iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
224 	err = 0;
225 out:
226 	return err;
227 }
228 
229 static void ipip_ecn_decapsulate(struct sk_buff *skb)
230 {
231 	struct iphdr *inner_iph = ipip_hdr(skb);
232 
233 	if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
234 		IP_ECN_set_ce(inner_iph);
235 }
236 
237 static int xfrm4_remove_tunnel_encap(struct xfrm_state *x, struct sk_buff *skb)
238 {
239 	int err = -EINVAL;
240 
241 	skb->protocol = htons(ETH_P_IP);
242 
243 	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
244 		goto out;
245 
246 	err = skb_unclone(skb, GFP_ATOMIC);
247 	if (err)
248 		goto out;
249 
250 	if (x->props.flags & XFRM_STATE_DECAP_DSCP)
251 		ipv4_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, ipip_hdr(skb));
252 	if (!(x->props.flags & XFRM_STATE_NOECN))
253 		ipip_ecn_decapsulate(skb);
254 
255 	skb_reset_network_header(skb);
256 	skb_mac_header_rebuild(skb);
257 	if (skb->mac_len)
258 		eth_hdr(skb)->h_proto = skb->protocol;
259 
260 	err = 0;
261 
262 out:
263 	return err;
264 }
265 
266 static void ipip6_ecn_decapsulate(struct sk_buff *skb)
267 {
268 	struct ipv6hdr *inner_iph = ipipv6_hdr(skb);
269 
270 	if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
271 		IP6_ECN_set_ce(skb, inner_iph);
272 }
273 
274 static int xfrm6_remove_tunnel_encap(struct xfrm_state *x, struct sk_buff *skb)
275 {
276 	int err = -EINVAL;
277 
278 	skb->protocol = htons(ETH_P_IPV6);
279 
280 	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
281 		goto out;
282 
283 	err = skb_unclone(skb, GFP_ATOMIC);
284 	if (err)
285 		goto out;
286 
287 	if (x->props.flags & XFRM_STATE_DECAP_DSCP)
288 		ipv6_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, ipipv6_hdr(skb));
289 	if (!(x->props.flags & XFRM_STATE_NOECN))
290 		ipip6_ecn_decapsulate(skb);
291 
292 	skb_reset_network_header(skb);
293 	skb_mac_header_rebuild(skb);
294 	if (skb->mac_len)
295 		eth_hdr(skb)->h_proto = skb->protocol;
296 
297 	err = 0;
298 
299 out:
300 	return err;
301 }
302 
303 static int xfrm6_remove_beet_encap(struct xfrm_state *x, struct sk_buff *skb)
304 {
305 	struct ipv6hdr *ip6h;
306 	int size = sizeof(struct ipv6hdr);
307 	int err;
308 
309 	skb->protocol = htons(ETH_P_IPV6);
310 
311 	err = skb_cow_head(skb, size + skb->mac_len);
312 	if (err)
313 		goto out;
314 
315 	__skb_push(skb, size);
316 	skb_reset_network_header(skb);
317 	skb_mac_header_rebuild(skb);
318 
319 	xfrm6_beet_make_header(skb);
320 
321 	ip6h = ipv6_hdr(skb);
322 	ip6h->payload_len = htons(skb->len - size);
323 	ip6h->daddr = x->sel.daddr.in6;
324 	ip6h->saddr = x->sel.saddr.in6;
325 	err = 0;
326 out:
327 	return err;
328 }
329 
330 /* Remove encapsulation header.
331  *
332  * The IP header will be moved over the top of the encapsulation
333  * header.
334  *
335  * On entry, the transport header shall point to where the IP header
336  * should be and the network header shall be set to where the IP
337  * header currently is.  skb->data shall point to the start of the
338  * payload.
339  */
340 static int
341 xfrm_inner_mode_encap_remove(struct xfrm_state *x,
342 			     struct sk_buff *skb)
343 {
344 	switch (x->props.mode) {
345 	case XFRM_MODE_BEET:
346 		switch (x->sel.family) {
347 		case AF_INET:
348 			return xfrm4_remove_beet_encap(x, skb);
349 		case AF_INET6:
350 			return xfrm6_remove_beet_encap(x, skb);
351 		}
352 		break;
353 	case XFRM_MODE_TUNNEL:
354 		switch (XFRM_MODE_SKB_CB(skb)->protocol) {
355 		case IPPROTO_IPIP:
356 			return xfrm4_remove_tunnel_encap(x, skb);
357 		case IPPROTO_IPV6:
358 			return xfrm6_remove_tunnel_encap(x, skb);
359 		break;
360 		}
361 		return -EINVAL;
362 	}
363 
364 	WARN_ON_ONCE(1);
365 	return -EOPNOTSUPP;
366 }
367 
368 static int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb)
369 {
370 	switch (x->props.family) {
371 	case AF_INET:
372 		xfrm4_extract_header(skb);
373 		break;
374 	case AF_INET6:
375 		xfrm6_extract_header(skb);
376 		break;
377 	default:
378 		WARN_ON_ONCE(1);
379 		return -EAFNOSUPPORT;
380 	}
381 
382 	return xfrm_inner_mode_encap_remove(x, skb);
383 }
384 
385 /* Remove encapsulation header.
386  *
387  * The IP header will be moved over the top of the encapsulation header.
388  *
389  * On entry, skb_transport_header() shall point to where the IP header
390  * should be and skb_network_header() shall be set to where the IP header
391  * currently is.  skb->data shall point to the start of the payload.
392  */
393 static int xfrm4_transport_input(struct xfrm_state *x, struct sk_buff *skb)
394 {
395 	struct xfrm_offload *xo = xfrm_offload(skb);
396 	int ihl = skb->data - skb_transport_header(skb);
397 
398 	if (skb->transport_header != skb->network_header) {
399 		memmove(skb_transport_header(skb),
400 			skb_network_header(skb), ihl);
401 		if (xo)
402 			xo->orig_mac_len =
403 				skb_mac_header_was_set(skb) ? skb_mac_header_len(skb) : 0;
404 		skb->network_header = skb->transport_header;
405 	}
406 	ip_hdr(skb)->tot_len = htons(skb->len + ihl);
407 	skb_reset_transport_header(skb);
408 	return 0;
409 }
410 
411 static int xfrm6_transport_input(struct xfrm_state *x, struct sk_buff *skb)
412 {
413 #if IS_ENABLED(CONFIG_IPV6)
414 	struct xfrm_offload *xo = xfrm_offload(skb);
415 	int ihl = skb->data - skb_transport_header(skb);
416 
417 	if (skb->transport_header != skb->network_header) {
418 		memmove(skb_transport_header(skb),
419 			skb_network_header(skb), ihl);
420 		if (xo)
421 			xo->orig_mac_len =
422 				skb_mac_header_was_set(skb) ? skb_mac_header_len(skb) : 0;
423 		skb->network_header = skb->transport_header;
424 	}
425 	ipv6_hdr(skb)->payload_len = htons(skb->len + ihl -
426 					   sizeof(struct ipv6hdr));
427 	skb_reset_transport_header(skb);
428 	return 0;
429 #else
430 	WARN_ON_ONCE(1);
431 	return -EAFNOSUPPORT;
432 #endif
433 }
434 
435 static int xfrm_inner_mode_input(struct xfrm_state *x,
436 				 struct sk_buff *skb)
437 {
438 	switch (x->props.mode) {
439 	case XFRM_MODE_BEET:
440 	case XFRM_MODE_TUNNEL:
441 		return xfrm_prepare_input(x, skb);
442 	case XFRM_MODE_TRANSPORT:
443 		if (x->props.family == AF_INET)
444 			return xfrm4_transport_input(x, skb);
445 		if (x->props.family == AF_INET6)
446 			return xfrm6_transport_input(x, skb);
447 		break;
448 	case XFRM_MODE_ROUTEOPTIMIZATION:
449 		WARN_ON_ONCE(1);
450 		break;
451 	default:
452 		if (x->mode_cbs && x->mode_cbs->input)
453 			return x->mode_cbs->input(x, skb);
454 
455 		WARN_ON_ONCE(1);
456 		break;
457 	}
458 
459 	return -EOPNOTSUPP;
460 }
461 
462 /* NOTE: encap_type - In addition to the normal (non-negative) values for
463  * encap_type, a negative value of -1 or -2 can be used to resume/restart this
464  * function after a previous invocation early terminated for async operation.
465  */
466 int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
467 {
468 	const struct xfrm_state_afinfo *afinfo;
469 	struct net *net = dev_net(skb->dev);
470 	int err;
471 	__be32 seq;
472 	__be32 seq_hi;
473 	struct xfrm_state *x = NULL;
474 	xfrm_address_t *daddr;
475 	u32 mark = skb->mark;
476 	unsigned int family = AF_UNSPEC;
477 	int decaps = 0;
478 	int async = 0;
479 	bool xfrm_gro = false;
480 	bool crypto_done = false;
481 	struct xfrm_offload *xo = xfrm_offload(skb);
482 	struct sec_path *sp;
483 
484 	if (encap_type < 0 || (xo && (xo->flags & XFRM_GRO || encap_type == 0 ||
485 				      encap_type == UDP_ENCAP_ESPINUDP))) {
486 		x = xfrm_input_state(skb);
487 
488 		if (unlikely(x->km.state != XFRM_STATE_VALID)) {
489 			if (x->km.state == XFRM_STATE_ACQ)
490 				XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR);
491 			else
492 				XFRM_INC_STATS(net,
493 					       LINUX_MIB_XFRMINSTATEINVALID);
494 
495 			if (encap_type == -1)
496 				dev_put(skb->dev);
497 			goto drop;
498 		}
499 
500 		family = x->props.family;
501 
502 		/* An encap_type of -2 indicates reconstructed inner packet */
503 		if (encap_type == -2)
504 			goto resume_decapped;
505 
506 		/* An encap_type of -1 indicates async resumption. */
507 		if (encap_type == -1) {
508 			async = 1;
509 			dev_put(skb->dev);
510 			seq = XFRM_SKB_CB(skb)->seq.input.low;
511 			spin_lock(&x->lock);
512 			goto resume;
513 		}
514 		/* GRO call */
515 		seq = XFRM_SPI_SKB_CB(skb)->seq;
516 
517 		if (xo && (xo->flags & CRYPTO_DONE)) {
518 			crypto_done = true;
519 			family = XFRM_SPI_SKB_CB(skb)->family;
520 
521 			if (!(xo->status & CRYPTO_SUCCESS)) {
522 				if (xo->status &
523 				    (CRYPTO_TRANSPORT_AH_AUTH_FAILED |
524 				     CRYPTO_TRANSPORT_ESP_AUTH_FAILED |
525 				     CRYPTO_TUNNEL_AH_AUTH_FAILED |
526 				     CRYPTO_TUNNEL_ESP_AUTH_FAILED)) {
527 
528 					xfrm_audit_state_icvfail(x, skb,
529 								 x->type->proto);
530 					x->stats.integrity_failed++;
531 					XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
532 					goto drop;
533 				}
534 
535 				if (xo->status & CRYPTO_INVALID_PROTOCOL) {
536 					XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
537 					goto drop;
538 				}
539 
540 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
541 				goto drop;
542 			}
543 
544 			if (xfrm_parse_spi(skb, nexthdr, &spi, &seq)) {
545 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
546 				goto drop;
547 			}
548 
549 			nexthdr = x->type_offload->input_tail(x, skb);
550 		}
551 
552 		goto process;
553 	}
554 
555 	family = XFRM_SPI_SKB_CB(skb)->family;
556 
557 	/* if tunnel is present override skb->mark value with tunnel i_key */
558 	switch (family) {
559 	case AF_INET:
560 		if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4)
561 			mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4->parms.i_key);
562 		break;
563 	case AF_INET6:
564 		if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6)
565 			mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6->parms.i_key);
566 		break;
567 	}
568 
569 	sp = secpath_set(skb);
570 	if (!sp) {
571 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
572 		goto drop;
573 	}
574 
575 	seq = 0;
576 	if (!spi && xfrm_parse_spi(skb, nexthdr, &spi, &seq)) {
577 		secpath_reset(skb);
578 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
579 		goto drop;
580 	}
581 
582 	daddr = (xfrm_address_t *)(skb_network_header(skb) +
583 				   XFRM_SPI_SKB_CB(skb)->daddroff);
584 	do {
585 		sp = skb_sec_path(skb);
586 
587 		if (sp->len == XFRM_MAX_DEPTH) {
588 			secpath_reset(skb);
589 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
590 			goto drop;
591 		}
592 
593 		x = xfrm_input_state_lookup(net, mark, daddr, spi, nexthdr, family);
594 		if (x == NULL) {
595 			secpath_reset(skb);
596 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
597 			xfrm_audit_state_notfound(skb, family, spi, seq);
598 			goto drop;
599 		}
600 
601 		if (unlikely(x->dir && x->dir != XFRM_SA_DIR_IN)) {
602 			secpath_reset(skb);
603 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEDIRERROR);
604 			xfrm_audit_state_notfound(skb, family, spi, seq);
605 			xfrm_state_put(x);
606 			x = NULL;
607 			goto drop;
608 		}
609 
610 		skb->mark = xfrm_smark_get(skb->mark, x);
611 
612 		sp->xvec[sp->len++] = x;
613 
614 		skb_dst_force(skb);
615 		if (!skb_dst(skb)) {
616 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
617 			goto drop;
618 		}
619 
620 process:
621 		seq_hi = htonl(xfrm_replay_seqhi(x, seq));
622 
623 		XFRM_SKB_CB(skb)->seq.input.low = seq;
624 		XFRM_SKB_CB(skb)->seq.input.hi = seq_hi;
625 
626 		spin_lock(&x->lock);
627 
628 		if (unlikely(x->km.state != XFRM_STATE_VALID)) {
629 			if (x->km.state == XFRM_STATE_ACQ)
630 				XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR);
631 			else
632 				XFRM_INC_STATS(net,
633 					       LINUX_MIB_XFRMINSTATEINVALID);
634 			goto drop_unlock;
635 		}
636 
637 		if ((x->encap ? x->encap->encap_type : 0) != encap_type) {
638 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
639 			goto drop_unlock;
640 		}
641 
642 		if (xfrm_replay_check(x, skb, seq)) {
643 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
644 			goto drop_unlock;
645 		}
646 
647 		if (xfrm_state_check_expire(x)) {
648 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEEXPIRED);
649 			goto drop_unlock;
650 		}
651 
652 		if (xfrm_tunnel_check(skb, x, family)) {
653 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
654 			goto drop_unlock;
655 		}
656 
657 		if (!crypto_done) {
658 			spin_unlock(&x->lock);
659 			dev_hold(skb->dev);
660 
661 			nexthdr = x->type->input(x, skb);
662 			if (nexthdr == -EINPROGRESS)
663 				return 0;
664 
665 			dev_put(skb->dev);
666 			spin_lock(&x->lock);
667 		}
668 resume:
669 		if (nexthdr < 0) {
670 			if (nexthdr == -EBADMSG) {
671 				xfrm_audit_state_icvfail(x, skb,
672 							 x->type->proto);
673 				x->stats.integrity_failed++;
674 			}
675 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
676 			goto drop_unlock;
677 		}
678 
679 		/* only the first xfrm gets the encap type */
680 		encap_type = 0;
681 
682 		if (!crypto_done && xfrm_replay_recheck(x, skb, seq)) {
683 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
684 			goto drop_unlock;
685 		}
686 
687 		xfrm_replay_advance(x, seq);
688 
689 		x->curlft.bytes += skb->len;
690 		x->curlft.packets++;
691 		x->lastused = ktime_get_real_seconds();
692 
693 		spin_unlock(&x->lock);
694 
695 		XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;
696 
697 		err = xfrm_inner_mode_input(x, skb);
698 		if (err == -EINPROGRESS)
699 			return 0;
700 		else if (err) {
701 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
702 			goto drop;
703 		}
704 resume_decapped:
705 		if (x->outer_mode.flags & XFRM_MODE_FLAG_TUNNEL) {
706 			decaps = 1;
707 			break;
708 		}
709 
710 		/*
711 		 * We need the inner address.  However, we only get here for
712 		 * transport mode so the outer address is identical.
713 		 */
714 		daddr = &x->id.daddr;
715 		family = x->props.family;
716 
717 		err = xfrm_parse_spi(skb, nexthdr, &spi, &seq);
718 		if (err < 0) {
719 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
720 			goto drop;
721 		}
722 		crypto_done = false;
723 	} while (!err);
724 
725 	err = xfrm_rcv_cb(skb, family, x->type->proto, 0);
726 	if (err)
727 		goto drop;
728 
729 	nf_reset_ct(skb);
730 
731 	if (decaps) {
732 		sp = skb_sec_path(skb);
733 		if (sp)
734 			sp->olen = 0;
735 		if (skb_valid_dst(skb))
736 			skb_dst_drop(skb);
737 		gro_cells_receive(&gro_cells, skb);
738 		return 0;
739 	} else {
740 		xo = xfrm_offload(skb);
741 		if (xo)
742 			xfrm_gro = xo->flags & XFRM_GRO;
743 
744 		err = -EAFNOSUPPORT;
745 		rcu_read_lock();
746 		afinfo = xfrm_state_afinfo_get_rcu(x->props.family);
747 		if (likely(afinfo))
748 			err = afinfo->transport_finish(skb, xfrm_gro || async);
749 		rcu_read_unlock();
750 		if (xfrm_gro) {
751 			sp = skb_sec_path(skb);
752 			if (sp)
753 				sp->olen = 0;
754 			if (skb_valid_dst(skb))
755 				skb_dst_drop(skb);
756 			gro_cells_receive(&gro_cells, skb);
757 			return err;
758 		}
759 
760 		return err;
761 	}
762 
763 drop_unlock:
764 	spin_unlock(&x->lock);
765 drop:
766 	xfrm_rcv_cb(skb, family, x && x->type ? x->type->proto : nexthdr, -1);
767 	kfree_skb(skb);
768 	return 0;
769 }
770 EXPORT_SYMBOL(xfrm_input);
771 
772 int xfrm_input_resume(struct sk_buff *skb, int nexthdr)
773 {
774 	return xfrm_input(skb, nexthdr, 0, -1);
775 }
776 EXPORT_SYMBOL(xfrm_input_resume);
777 
778 static void xfrm_trans_reinject(struct work_struct *work)
779 {
780 	struct xfrm_trans_tasklet *trans = container_of(work, struct xfrm_trans_tasklet, work);
781 	struct sk_buff_head queue;
782 	struct sk_buff *skb;
783 
784 	__skb_queue_head_init(&queue);
785 	spin_lock_bh(&trans->queue_lock);
786 	skb_queue_splice_init(&trans->queue, &queue);
787 	spin_unlock_bh(&trans->queue_lock);
788 
789 	local_bh_disable();
790 	while ((skb = __skb_dequeue(&queue)))
791 		XFRM_TRANS_SKB_CB(skb)->finish(XFRM_TRANS_SKB_CB(skb)->net,
792 					       NULL, skb);
793 	local_bh_enable();
794 }
795 
796 int xfrm_trans_queue_net(struct net *net, struct sk_buff *skb,
797 			 int (*finish)(struct net *, struct sock *,
798 				       struct sk_buff *))
799 {
800 	struct xfrm_trans_tasklet *trans;
801 
802 	trans = this_cpu_ptr(&xfrm_trans_tasklet);
803 
804 	if (skb_queue_len(&trans->queue) >= READ_ONCE(net_hotdata.max_backlog))
805 		return -ENOBUFS;
806 
807 	BUILD_BUG_ON(sizeof(struct xfrm_trans_cb) > sizeof(skb->cb));
808 
809 	XFRM_TRANS_SKB_CB(skb)->finish = finish;
810 	XFRM_TRANS_SKB_CB(skb)->net = net;
811 	spin_lock_bh(&trans->queue_lock);
812 	__skb_queue_tail(&trans->queue, skb);
813 	spin_unlock_bh(&trans->queue_lock);
814 	schedule_work(&trans->work);
815 	return 0;
816 }
817 EXPORT_SYMBOL(xfrm_trans_queue_net);
818 
819 int xfrm_trans_queue(struct sk_buff *skb,
820 		     int (*finish)(struct net *, struct sock *,
821 				   struct sk_buff *))
822 {
823 	return xfrm_trans_queue_net(dev_net(skb->dev), skb, finish);
824 }
825 EXPORT_SYMBOL(xfrm_trans_queue);
826 
827 void __init xfrm_input_init(void)
828 {
829 	int err;
830 	int i;
831 
832 	xfrm_napi_dev = alloc_netdev_dummy(0);
833 	if (!xfrm_napi_dev)
834 		panic("Failed to allocate XFRM dummy netdev\n");
835 
836 	err = gro_cells_init(&gro_cells, xfrm_napi_dev);
837 	if (err)
838 		gro_cells.cells = NULL;
839 
840 	for_each_possible_cpu(i) {
841 		struct xfrm_trans_tasklet *trans;
842 
843 		trans = &per_cpu(xfrm_trans_tasklet, i);
844 		spin_lock_init(&trans->queue_lock);
845 		__skb_queue_head_init(&trans->queue);
846 		INIT_WORK(&trans->work, xfrm_trans_reinject);
847 	}
848 }
849