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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 
24 #include "xfrm_inout.h"
25 
26 struct xfrm_trans_tasklet {
27 	struct tasklet_struct tasklet;
28 	struct sk_buff_head queue;
29 };
30 
31 struct xfrm_trans_cb {
32 	union {
33 		struct inet_skb_parm	h4;
34 #if IS_ENABLED(CONFIG_IPV6)
35 		struct inet6_skb_parm	h6;
36 #endif
37 	} header;
38 	int (*finish)(struct net *net, struct sock *sk, struct sk_buff *skb);
39 };
40 
41 #define XFRM_TRANS_SKB_CB(__skb) ((struct xfrm_trans_cb *)&((__skb)->cb[0]))
42 
43 static DEFINE_SPINLOCK(xfrm_input_afinfo_lock);
44 static struct xfrm_input_afinfo const __rcu *xfrm_input_afinfo[AF_INET6 + 1];
45 
46 static struct gro_cells gro_cells;
47 static struct net_device xfrm_napi_dev;
48 
49 static DEFINE_PER_CPU(struct xfrm_trans_tasklet, xfrm_trans_tasklet);
50 
xfrm_input_register_afinfo(const struct xfrm_input_afinfo * afinfo)51 int xfrm_input_register_afinfo(const struct xfrm_input_afinfo *afinfo)
52 {
53 	int err = 0;
54 
55 	if (WARN_ON(afinfo->family >= ARRAY_SIZE(xfrm_input_afinfo)))
56 		return -EAFNOSUPPORT;
57 
58 	spin_lock_bh(&xfrm_input_afinfo_lock);
59 	if (unlikely(xfrm_input_afinfo[afinfo->family] != NULL))
60 		err = -EEXIST;
61 	else
62 		rcu_assign_pointer(xfrm_input_afinfo[afinfo->family], afinfo);
63 	spin_unlock_bh(&xfrm_input_afinfo_lock);
64 	return err;
65 }
66 EXPORT_SYMBOL(xfrm_input_register_afinfo);
67 
xfrm_input_unregister_afinfo(const struct xfrm_input_afinfo * afinfo)68 int xfrm_input_unregister_afinfo(const struct xfrm_input_afinfo *afinfo)
69 {
70 	int err = 0;
71 
72 	spin_lock_bh(&xfrm_input_afinfo_lock);
73 	if (likely(xfrm_input_afinfo[afinfo->family] != NULL)) {
74 		if (unlikely(xfrm_input_afinfo[afinfo->family] != afinfo))
75 			err = -EINVAL;
76 		else
77 			RCU_INIT_POINTER(xfrm_input_afinfo[afinfo->family], NULL);
78 	}
79 	spin_unlock_bh(&xfrm_input_afinfo_lock);
80 	synchronize_rcu();
81 	return err;
82 }
83 EXPORT_SYMBOL(xfrm_input_unregister_afinfo);
84 
xfrm_input_get_afinfo(unsigned int family)85 static const struct xfrm_input_afinfo *xfrm_input_get_afinfo(unsigned int family)
86 {
87 	const struct xfrm_input_afinfo *afinfo;
88 
89 	if (WARN_ON_ONCE(family >= ARRAY_SIZE(xfrm_input_afinfo)))
90 		return NULL;
91 
92 	rcu_read_lock();
93 	afinfo = rcu_dereference(xfrm_input_afinfo[family]);
94 	if (unlikely(!afinfo))
95 		rcu_read_unlock();
96 	return afinfo;
97 }
98 
xfrm_rcv_cb(struct sk_buff * skb,unsigned int family,u8 protocol,int err)99 static int xfrm_rcv_cb(struct sk_buff *skb, unsigned int family, u8 protocol,
100 		       int err)
101 {
102 	int ret;
103 	const struct xfrm_input_afinfo *afinfo = xfrm_input_get_afinfo(family);
104 
105 	if (!afinfo)
106 		return -EAFNOSUPPORT;
107 
108 	ret = afinfo->callback(skb, protocol, err);
109 	rcu_read_unlock();
110 
111 	return ret;
112 }
113 
secpath_set(struct sk_buff * skb)114 struct sec_path *secpath_set(struct sk_buff *skb)
115 {
116 	struct sec_path *sp, *tmp = skb_ext_find(skb, SKB_EXT_SEC_PATH);
117 
118 	sp = skb_ext_add(skb, SKB_EXT_SEC_PATH);
119 	if (!sp)
120 		return NULL;
121 
122 	if (tmp) /* reused existing one (was COW'd if needed) */
123 		return sp;
124 
125 	/* allocated new secpath */
126 	memset(sp->ovec, 0, sizeof(sp->ovec));
127 	sp->olen = 0;
128 	sp->len = 0;
129 
130 	return sp;
131 }
132 EXPORT_SYMBOL(secpath_set);
133 
134 /* Fetch spi and seq from ipsec header */
135 
xfrm_parse_spi(struct sk_buff * skb,u8 nexthdr,__be32 * spi,__be32 * seq)136 int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq)
137 {
138 	int offset, offset_seq;
139 	int hlen;
140 
141 	switch (nexthdr) {
142 	case IPPROTO_AH:
143 		hlen = sizeof(struct ip_auth_hdr);
144 		offset = offsetof(struct ip_auth_hdr, spi);
145 		offset_seq = offsetof(struct ip_auth_hdr, seq_no);
146 		break;
147 	case IPPROTO_ESP:
148 		hlen = sizeof(struct ip_esp_hdr);
149 		offset = offsetof(struct ip_esp_hdr, spi);
150 		offset_seq = offsetof(struct ip_esp_hdr, seq_no);
151 		break;
152 	case IPPROTO_COMP:
153 		if (!pskb_may_pull(skb, sizeof(struct ip_comp_hdr)))
154 			return -EINVAL;
155 		*spi = htonl(ntohs(*(__be16 *)(skb_transport_header(skb) + 2)));
156 		*seq = 0;
157 		return 0;
158 	default:
159 		return 1;
160 	}
161 
162 	if (!pskb_may_pull(skb, hlen))
163 		return -EINVAL;
164 
165 	*spi = *(__be32 *)(skb_transport_header(skb) + offset);
166 	*seq = *(__be32 *)(skb_transport_header(skb) + offset_seq);
167 	return 0;
168 }
169 EXPORT_SYMBOL(xfrm_parse_spi);
170 
xfrm4_remove_beet_encap(struct xfrm_state * x,struct sk_buff * skb)171 static int xfrm4_remove_beet_encap(struct xfrm_state *x, struct sk_buff *skb)
172 {
173 	struct iphdr *iph;
174 	int optlen = 0;
175 	int err = -EINVAL;
176 
177 	if (unlikely(XFRM_MODE_SKB_CB(skb)->protocol == IPPROTO_BEETPH)) {
178 		struct ip_beet_phdr *ph;
179 		int phlen;
180 
181 		if (!pskb_may_pull(skb, sizeof(*ph)))
182 			goto out;
183 
184 		ph = (struct ip_beet_phdr *)skb->data;
185 
186 		phlen = sizeof(*ph) + ph->padlen;
187 		optlen = ph->hdrlen * 8 + (IPV4_BEET_PHMAXLEN - phlen);
188 		if (optlen < 0 || optlen & 3 || optlen > 250)
189 			goto out;
190 
191 		XFRM_MODE_SKB_CB(skb)->protocol = ph->nexthdr;
192 
193 		if (!pskb_may_pull(skb, phlen))
194 			goto out;
195 		__skb_pull(skb, phlen);
196 	}
197 
198 	skb_push(skb, sizeof(*iph));
199 	skb_reset_network_header(skb);
200 	skb_mac_header_rebuild(skb);
201 
202 	xfrm4_beet_make_header(skb);
203 
204 	iph = ip_hdr(skb);
205 
206 	iph->ihl += optlen / 4;
207 	iph->tot_len = htons(skb->len);
208 	iph->daddr = x->sel.daddr.a4;
209 	iph->saddr = x->sel.saddr.a4;
210 	iph->check = 0;
211 	iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
212 	err = 0;
213 out:
214 	return err;
215 }
216 
ipip_ecn_decapsulate(struct sk_buff * skb)217 static void ipip_ecn_decapsulate(struct sk_buff *skb)
218 {
219 	struct iphdr *inner_iph = ipip_hdr(skb);
220 
221 	if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
222 		IP_ECN_set_ce(inner_iph);
223 }
224 
xfrm4_remove_tunnel_encap(struct xfrm_state * x,struct sk_buff * skb)225 static int xfrm4_remove_tunnel_encap(struct xfrm_state *x, struct sk_buff *skb)
226 {
227 	int err = -EINVAL;
228 
229 	if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPIP)
230 		goto out;
231 
232 	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
233 		goto out;
234 
235 	err = skb_unclone(skb, GFP_ATOMIC);
236 	if (err)
237 		goto out;
238 
239 	if (x->props.flags & XFRM_STATE_DECAP_DSCP)
240 		ipv4_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, ipip_hdr(skb));
241 	if (!(x->props.flags & XFRM_STATE_NOECN))
242 		ipip_ecn_decapsulate(skb);
243 
244 	skb_reset_network_header(skb);
245 	skb_mac_header_rebuild(skb);
246 	if (skb->mac_len)
247 		eth_hdr(skb)->h_proto = skb->protocol;
248 
249 	err = 0;
250 
251 out:
252 	return err;
253 }
254 
ipip6_ecn_decapsulate(struct sk_buff * skb)255 static void ipip6_ecn_decapsulate(struct sk_buff *skb)
256 {
257 	struct ipv6hdr *inner_iph = ipipv6_hdr(skb);
258 
259 	if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
260 		IP6_ECN_set_ce(skb, inner_iph);
261 }
262 
xfrm6_remove_tunnel_encap(struct xfrm_state * x,struct sk_buff * skb)263 static int xfrm6_remove_tunnel_encap(struct xfrm_state *x, struct sk_buff *skb)
264 {
265 	int err = -EINVAL;
266 
267 	if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
268 		goto out;
269 	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
270 		goto out;
271 
272 	err = skb_unclone(skb, GFP_ATOMIC);
273 	if (err)
274 		goto out;
275 
276 	if (x->props.flags & XFRM_STATE_DECAP_DSCP)
277 		ipv6_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, ipipv6_hdr(skb));
278 	if (!(x->props.flags & XFRM_STATE_NOECN))
279 		ipip6_ecn_decapsulate(skb);
280 
281 	skb_reset_network_header(skb);
282 	skb_mac_header_rebuild(skb);
283 	if (skb->mac_len)
284 		eth_hdr(skb)->h_proto = skb->protocol;
285 
286 	err = 0;
287 
288 out:
289 	return err;
290 }
291 
xfrm6_remove_beet_encap(struct xfrm_state * x,struct sk_buff * skb)292 static int xfrm6_remove_beet_encap(struct xfrm_state *x, struct sk_buff *skb)
293 {
294 	struct ipv6hdr *ip6h;
295 	int size = sizeof(struct ipv6hdr);
296 	int err;
297 
298 	err = skb_cow_head(skb, size + skb->mac_len);
299 	if (err)
300 		goto out;
301 
302 	__skb_push(skb, size);
303 	skb_reset_network_header(skb);
304 	skb_mac_header_rebuild(skb);
305 
306 	xfrm6_beet_make_header(skb);
307 
308 	ip6h = ipv6_hdr(skb);
309 	ip6h->payload_len = htons(skb->len - size);
310 	ip6h->daddr = x->sel.daddr.in6;
311 	ip6h->saddr = x->sel.saddr.in6;
312 	err = 0;
313 out:
314 	return err;
315 }
316 
317 /* Remove encapsulation header.
318  *
319  * The IP header will be moved over the top of the encapsulation
320  * header.
321  *
322  * On entry, the transport header shall point to where the IP header
323  * should be and the network header shall be set to where the IP
324  * header currently is.  skb->data shall point to the start of the
325  * payload.
326  */
327 static int
xfrm_inner_mode_encap_remove(struct xfrm_state * x,const struct xfrm_mode * inner_mode,struct sk_buff * skb)328 xfrm_inner_mode_encap_remove(struct xfrm_state *x,
329 			     const struct xfrm_mode *inner_mode,
330 			     struct sk_buff *skb)
331 {
332 	switch (inner_mode->encap) {
333 	case XFRM_MODE_BEET:
334 		if (inner_mode->family == AF_INET)
335 			return xfrm4_remove_beet_encap(x, skb);
336 		if (inner_mode->family == AF_INET6)
337 			return xfrm6_remove_beet_encap(x, skb);
338 		break;
339 	case XFRM_MODE_TUNNEL:
340 		if (inner_mode->family == AF_INET)
341 			return xfrm4_remove_tunnel_encap(x, skb);
342 		if (inner_mode->family == AF_INET6)
343 			return xfrm6_remove_tunnel_encap(x, skb);
344 		break;
345 	}
346 
347 	WARN_ON_ONCE(1);
348 	return -EOPNOTSUPP;
349 }
350 
xfrm_prepare_input(struct xfrm_state * x,struct sk_buff * skb)351 static int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb)
352 {
353 	const struct xfrm_mode *inner_mode = &x->inner_mode;
354 	const struct xfrm_state_afinfo *afinfo;
355 	int err = -EAFNOSUPPORT;
356 
357 	rcu_read_lock();
358 	afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode.family);
359 	if (likely(afinfo))
360 		err = afinfo->extract_input(x, skb);
361 	rcu_read_unlock();
362 
363 	if (err)
364 		return err;
365 
366 	if (x->sel.family == AF_UNSPEC) {
367 		inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
368 		if (!inner_mode)
369 			return -EAFNOSUPPORT;
370 	}
371 
372 	switch (inner_mode->family) {
373 	case AF_INET:
374 		skb->protocol = htons(ETH_P_IP);
375 		break;
376 	case AF_INET6:
377 		skb->protocol = htons(ETH_P_IPV6);
378 		break;
379 	default:
380 		WARN_ON_ONCE(1);
381 		break;
382 	}
383 
384 	return xfrm_inner_mode_encap_remove(x, inner_mode, skb);
385 }
386 
387 /* Remove encapsulation header.
388  *
389  * The IP header will be moved over the top of the encapsulation header.
390  *
391  * On entry, skb_transport_header() shall point to where the IP header
392  * should be and skb_network_header() shall be set to where the IP header
393  * currently is.  skb->data shall point to the start of the payload.
394  */
xfrm4_transport_input(struct xfrm_state * x,struct sk_buff * skb)395 static int xfrm4_transport_input(struct xfrm_state *x, struct sk_buff *skb)
396 {
397 	int ihl = skb->data - skb_transport_header(skb);
398 
399 	if (skb->transport_header != skb->network_header) {
400 		memmove(skb_transport_header(skb),
401 			skb_network_header(skb), ihl);
402 		skb->network_header = skb->transport_header;
403 	}
404 	ip_hdr(skb)->tot_len = htons(skb->len + ihl);
405 	skb_reset_transport_header(skb);
406 	return 0;
407 }
408 
xfrm6_transport_input(struct xfrm_state * x,struct sk_buff * skb)409 static int xfrm6_transport_input(struct xfrm_state *x, struct sk_buff *skb)
410 {
411 #if IS_ENABLED(CONFIG_IPV6)
412 	int ihl = skb->data - skb_transport_header(skb);
413 
414 	if (skb->transport_header != skb->network_header) {
415 		memmove(skb_transport_header(skb),
416 			skb_network_header(skb), ihl);
417 		skb->network_header = skb->transport_header;
418 	}
419 	ipv6_hdr(skb)->payload_len = htons(skb->len + ihl -
420 					   sizeof(struct ipv6hdr));
421 	skb_reset_transport_header(skb);
422 	return 0;
423 #else
424 	WARN_ON_ONCE(1);
425 	return -EAFNOSUPPORT;
426 #endif
427 }
428 
xfrm_inner_mode_input(struct xfrm_state * x,const struct xfrm_mode * inner_mode,struct sk_buff * skb)429 static int xfrm_inner_mode_input(struct xfrm_state *x,
430 				 const struct xfrm_mode *inner_mode,
431 				 struct sk_buff *skb)
432 {
433 	switch (inner_mode->encap) {
434 	case XFRM_MODE_BEET:
435 	case XFRM_MODE_TUNNEL:
436 		return xfrm_prepare_input(x, skb);
437 	case XFRM_MODE_TRANSPORT:
438 		if (inner_mode->family == AF_INET)
439 			return xfrm4_transport_input(x, skb);
440 		if (inner_mode->family == AF_INET6)
441 			return xfrm6_transport_input(x, skb);
442 		break;
443 	case XFRM_MODE_ROUTEOPTIMIZATION:
444 		WARN_ON_ONCE(1);
445 		break;
446 	default:
447 		WARN_ON_ONCE(1);
448 		break;
449 	}
450 
451 	return -EOPNOTSUPP;
452 }
453 
xfrm_input(struct sk_buff * skb,int nexthdr,__be32 spi,int encap_type)454 int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
455 {
456 	const struct xfrm_state_afinfo *afinfo;
457 	struct net *net = dev_net(skb->dev);
458 	const struct xfrm_mode *inner_mode;
459 	int err;
460 	__be32 seq;
461 	__be32 seq_hi;
462 	struct xfrm_state *x = NULL;
463 	xfrm_address_t *daddr;
464 	u32 mark = skb->mark;
465 	unsigned int family = AF_UNSPEC;
466 	int decaps = 0;
467 	int async = 0;
468 	bool xfrm_gro = false;
469 	bool crypto_done = false;
470 	struct xfrm_offload *xo = xfrm_offload(skb);
471 	struct sec_path *sp;
472 
473 	if (encap_type < 0) {
474 		x = xfrm_input_state(skb);
475 
476 		if (unlikely(x->km.state != XFRM_STATE_VALID)) {
477 			if (x->km.state == XFRM_STATE_ACQ)
478 				XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR);
479 			else
480 				XFRM_INC_STATS(net,
481 					       LINUX_MIB_XFRMINSTATEINVALID);
482 
483 			if (encap_type == -1)
484 				dev_put(skb->dev);
485 			goto drop;
486 		}
487 
488 		family = x->outer_mode.family;
489 
490 		/* An encap_type of -1 indicates async resumption. */
491 		if (encap_type == -1) {
492 			async = 1;
493 			seq = XFRM_SKB_CB(skb)->seq.input.low;
494 			goto resume;
495 		}
496 
497 		/* encap_type < -1 indicates a GRO call. */
498 		encap_type = 0;
499 		seq = XFRM_SPI_SKB_CB(skb)->seq;
500 
501 		if (xo && (xo->flags & CRYPTO_DONE)) {
502 			crypto_done = true;
503 			family = XFRM_SPI_SKB_CB(skb)->family;
504 
505 			if (!(xo->status & CRYPTO_SUCCESS)) {
506 				if (xo->status &
507 				    (CRYPTO_TRANSPORT_AH_AUTH_FAILED |
508 				     CRYPTO_TRANSPORT_ESP_AUTH_FAILED |
509 				     CRYPTO_TUNNEL_AH_AUTH_FAILED |
510 				     CRYPTO_TUNNEL_ESP_AUTH_FAILED)) {
511 
512 					xfrm_audit_state_icvfail(x, skb,
513 								 x->type->proto);
514 					x->stats.integrity_failed++;
515 					XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
516 					goto drop;
517 				}
518 
519 				if (xo->status & CRYPTO_INVALID_PROTOCOL) {
520 					XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
521 					goto drop;
522 				}
523 
524 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
525 				goto drop;
526 			}
527 
528 			if ((err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0) {
529 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
530 				goto drop;
531 			}
532 		}
533 
534 		goto lock;
535 	}
536 
537 	family = XFRM_SPI_SKB_CB(skb)->family;
538 
539 	/* if tunnel is present override skb->mark value with tunnel i_key */
540 	switch (family) {
541 	case AF_INET:
542 		if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4)
543 			mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4->parms.i_key);
544 		break;
545 	case AF_INET6:
546 		if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6)
547 			mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6->parms.i_key);
548 		break;
549 	}
550 
551 	sp = secpath_set(skb);
552 	if (!sp) {
553 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
554 		goto drop;
555 	}
556 
557 	seq = 0;
558 	if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0) {
559 		secpath_reset(skb);
560 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
561 		goto drop;
562 	}
563 
564 	daddr = (xfrm_address_t *)(skb_network_header(skb) +
565 				   XFRM_SPI_SKB_CB(skb)->daddroff);
566 	do {
567 		sp = skb_sec_path(skb);
568 
569 		if (sp->len == XFRM_MAX_DEPTH) {
570 			secpath_reset(skb);
571 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
572 			goto drop;
573 		}
574 
575 		x = xfrm_state_lookup(net, mark, daddr, spi, nexthdr, family);
576 		if (x == NULL) {
577 			secpath_reset(skb);
578 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
579 			xfrm_audit_state_notfound(skb, family, spi, seq);
580 			goto drop;
581 		}
582 
583 		skb->mark = xfrm_smark_get(skb->mark, x);
584 
585 		sp->xvec[sp->len++] = x;
586 
587 		skb_dst_force(skb);
588 		if (!skb_dst(skb)) {
589 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
590 			goto drop;
591 		}
592 
593 lock:
594 		spin_lock(&x->lock);
595 
596 		if (unlikely(x->km.state != XFRM_STATE_VALID)) {
597 			if (x->km.state == XFRM_STATE_ACQ)
598 				XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR);
599 			else
600 				XFRM_INC_STATS(net,
601 					       LINUX_MIB_XFRMINSTATEINVALID);
602 			goto drop_unlock;
603 		}
604 
605 		if ((x->encap ? x->encap->encap_type : 0) != encap_type) {
606 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
607 			goto drop_unlock;
608 		}
609 
610 		if (x->repl->check(x, skb, seq)) {
611 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
612 			goto drop_unlock;
613 		}
614 
615 		if (xfrm_state_check_expire(x)) {
616 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEEXPIRED);
617 			goto drop_unlock;
618 		}
619 
620 		spin_unlock(&x->lock);
621 
622 		if (xfrm_tunnel_check(skb, x, family)) {
623 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
624 			goto drop;
625 		}
626 
627 		seq_hi = htonl(xfrm_replay_seqhi(x, seq));
628 
629 		XFRM_SKB_CB(skb)->seq.input.low = seq;
630 		XFRM_SKB_CB(skb)->seq.input.hi = seq_hi;
631 
632 		dev_hold(skb->dev);
633 
634 		if (crypto_done)
635 			nexthdr = x->type_offload->input_tail(x, skb);
636 		else
637 			nexthdr = x->type->input(x, skb);
638 
639 		if (nexthdr == -EINPROGRESS)
640 			return 0;
641 resume:
642 		dev_put(skb->dev);
643 
644 		spin_lock(&x->lock);
645 		if (nexthdr < 0) {
646 			if (nexthdr == -EBADMSG) {
647 				xfrm_audit_state_icvfail(x, skb,
648 							 x->type->proto);
649 				x->stats.integrity_failed++;
650 			}
651 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
652 			goto drop_unlock;
653 		}
654 
655 		/* only the first xfrm gets the encap type */
656 		encap_type = 0;
657 
658 		if (x->repl->recheck(x, skb, seq)) {
659 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
660 			goto drop_unlock;
661 		}
662 
663 		x->repl->advance(x, seq);
664 
665 		x->curlft.bytes += skb->len;
666 		x->curlft.packets++;
667 
668 		spin_unlock(&x->lock);
669 
670 		XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;
671 
672 		inner_mode = &x->inner_mode;
673 
674 		if (x->sel.family == AF_UNSPEC) {
675 			inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
676 			if (inner_mode == NULL) {
677 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
678 				goto drop;
679 			}
680 		}
681 
682 		if (xfrm_inner_mode_input(x, inner_mode, skb)) {
683 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
684 			goto drop;
685 		}
686 
687 		if (x->outer_mode.flags & XFRM_MODE_FLAG_TUNNEL) {
688 			decaps = 1;
689 			break;
690 		}
691 
692 		/*
693 		 * We need the inner address.  However, we only get here for
694 		 * transport mode so the outer address is identical.
695 		 */
696 		daddr = &x->id.daddr;
697 		family = x->outer_mode.family;
698 
699 		err = xfrm_parse_spi(skb, nexthdr, &spi, &seq);
700 		if (err < 0) {
701 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
702 			goto drop;
703 		}
704 		crypto_done = false;
705 	} while (!err);
706 
707 	err = xfrm_rcv_cb(skb, family, x->type->proto, 0);
708 	if (err)
709 		goto drop;
710 
711 	nf_reset_ct(skb);
712 
713 	if (decaps) {
714 		sp = skb_sec_path(skb);
715 		if (sp)
716 			sp->olen = 0;
717 		skb_dst_drop(skb);
718 		gro_cells_receive(&gro_cells, skb);
719 		return 0;
720 	} else {
721 		xo = xfrm_offload(skb);
722 		if (xo)
723 			xfrm_gro = xo->flags & XFRM_GRO;
724 
725 		err = -EAFNOSUPPORT;
726 		rcu_read_lock();
727 		afinfo = xfrm_state_afinfo_get_rcu(x->inner_mode.family);
728 		if (likely(afinfo))
729 			err = afinfo->transport_finish(skb, xfrm_gro || async);
730 		rcu_read_unlock();
731 		if (xfrm_gro) {
732 			sp = skb_sec_path(skb);
733 			if (sp)
734 				sp->olen = 0;
735 			skb_dst_drop(skb);
736 			gro_cells_receive(&gro_cells, skb);
737 			return err;
738 		}
739 
740 		return err;
741 	}
742 
743 drop_unlock:
744 	spin_unlock(&x->lock);
745 drop:
746 	xfrm_rcv_cb(skb, family, x && x->type ? x->type->proto : nexthdr, -1);
747 	kfree_skb(skb);
748 	return 0;
749 }
750 EXPORT_SYMBOL(xfrm_input);
751 
xfrm_input_resume(struct sk_buff * skb,int nexthdr)752 int xfrm_input_resume(struct sk_buff *skb, int nexthdr)
753 {
754 	return xfrm_input(skb, nexthdr, 0, -1);
755 }
756 EXPORT_SYMBOL(xfrm_input_resume);
757 
xfrm_trans_reinject(unsigned long data)758 static void xfrm_trans_reinject(unsigned long data)
759 {
760 	struct xfrm_trans_tasklet *trans = (void *)data;
761 	struct sk_buff_head queue;
762 	struct sk_buff *skb;
763 
764 	__skb_queue_head_init(&queue);
765 	skb_queue_splice_init(&trans->queue, &queue);
766 
767 	while ((skb = __skb_dequeue(&queue)))
768 		XFRM_TRANS_SKB_CB(skb)->finish(dev_net(skb->dev), NULL, skb);
769 }
770 
xfrm_trans_queue(struct sk_buff * skb,int (* finish)(struct net *,struct sock *,struct sk_buff *))771 int xfrm_trans_queue(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) >= netdev_max_backlog)
780 		return -ENOBUFS;
781 
782 	XFRM_TRANS_SKB_CB(skb)->finish = finish;
783 	__skb_queue_tail(&trans->queue, skb);
784 	tasklet_schedule(&trans->tasklet);
785 	return 0;
786 }
787 EXPORT_SYMBOL(xfrm_trans_queue);
788 
xfrm_input_init(void)789 void __init xfrm_input_init(void)
790 {
791 	int err;
792 	int i;
793 
794 	init_dummy_netdev(&xfrm_napi_dev);
795 	err = gro_cells_init(&gro_cells, &xfrm_napi_dev);
796 	if (err)
797 		gro_cells.cells = NULL;
798 
799 	for_each_possible_cpu(i) {
800 		struct xfrm_trans_tasklet *trans;
801 
802 		trans = &per_cpu(xfrm_trans_tasklet, i);
803 		__skb_queue_head_init(&trans->queue);
804 		tasklet_init(&trans->tasklet, xfrm_trans_reinject,
805 			     (unsigned long)trans);
806 	}
807 }
808