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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(ipv6_get_dsfield(ipv6_hdr(skb)),
278 			       ipipv6_hdr(skb));
279 	if (!(x->props.flags & XFRM_STATE_NOECN))
280 		ipip6_ecn_decapsulate(skb);
281 
282 	skb_reset_network_header(skb);
283 	skb_mac_header_rebuild(skb);
284 	if (skb->mac_len)
285 		eth_hdr(skb)->h_proto = skb->protocol;
286 
287 	err = 0;
288 
289 out:
290 	return err;
291 }
292 
xfrm6_remove_beet_encap(struct xfrm_state * x,struct sk_buff * skb)293 static int xfrm6_remove_beet_encap(struct xfrm_state *x, struct sk_buff *skb)
294 {
295 	struct ipv6hdr *ip6h;
296 	int size = sizeof(struct ipv6hdr);
297 	int err;
298 
299 	err = skb_cow_head(skb, size + skb->mac_len);
300 	if (err)
301 		goto out;
302 
303 	__skb_push(skb, size);
304 	skb_reset_network_header(skb);
305 	skb_mac_header_rebuild(skb);
306 
307 	xfrm6_beet_make_header(skb);
308 
309 	ip6h = ipv6_hdr(skb);
310 	ip6h->payload_len = htons(skb->len - size);
311 	ip6h->daddr = x->sel.daddr.in6;
312 	ip6h->saddr = x->sel.saddr.in6;
313 	err = 0;
314 out:
315 	return err;
316 }
317 
318 /* Remove encapsulation header.
319  *
320  * The IP header will be moved over the top of the encapsulation
321  * header.
322  *
323  * On entry, the transport header shall point to where the IP header
324  * should be and the network header shall be set to where the IP
325  * header currently is.  skb->data shall point to the start of the
326  * payload.
327  */
328 static int
xfrm_inner_mode_encap_remove(struct xfrm_state * x,const struct xfrm_mode * inner_mode,struct sk_buff * skb)329 xfrm_inner_mode_encap_remove(struct xfrm_state *x,
330 			     const struct xfrm_mode *inner_mode,
331 			     struct sk_buff *skb)
332 {
333 	switch (inner_mode->encap) {
334 	case XFRM_MODE_BEET:
335 		if (inner_mode->family == AF_INET)
336 			return xfrm4_remove_beet_encap(x, skb);
337 		if (inner_mode->family == AF_INET6)
338 			return xfrm6_remove_beet_encap(x, skb);
339 		break;
340 	case XFRM_MODE_TUNNEL:
341 		if (inner_mode->family == AF_INET)
342 			return xfrm4_remove_tunnel_encap(x, skb);
343 		if (inner_mode->family == AF_INET6)
344 			return xfrm6_remove_tunnel_encap(x, skb);
345 		break;
346 	}
347 
348 	WARN_ON_ONCE(1);
349 	return -EOPNOTSUPP;
350 }
351 
xfrm_prepare_input(struct xfrm_state * x,struct sk_buff * skb)352 static int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb)
353 {
354 	const struct xfrm_mode *inner_mode = &x->inner_mode;
355 	const struct xfrm_state_afinfo *afinfo;
356 	int err = -EAFNOSUPPORT;
357 
358 	rcu_read_lock();
359 	afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode.family);
360 	if (likely(afinfo))
361 		err = afinfo->extract_input(x, skb);
362 	rcu_read_unlock();
363 
364 	if (err)
365 		return err;
366 
367 	if (x->sel.family == AF_UNSPEC) {
368 		inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
369 		if (!inner_mode)
370 			return -EAFNOSUPPORT;
371 	}
372 
373 	switch (inner_mode->family) {
374 	case AF_INET:
375 		skb->protocol = htons(ETH_P_IP);
376 		break;
377 	case AF_INET6:
378 		skb->protocol = htons(ETH_P_IPV6);
379 		break;
380 	default:
381 		WARN_ON_ONCE(1);
382 		break;
383 	}
384 
385 	return xfrm_inner_mode_encap_remove(x, inner_mode, skb);
386 }
387 
388 /* Remove encapsulation header.
389  *
390  * The IP header will be moved over the top of the encapsulation header.
391  *
392  * On entry, skb_transport_header() shall point to where the IP header
393  * should be and skb_network_header() shall be set to where the IP header
394  * currently is.  skb->data shall point to the start of the payload.
395  */
xfrm4_transport_input(struct xfrm_state * x,struct sk_buff * skb)396 static int xfrm4_transport_input(struct xfrm_state *x, struct sk_buff *skb)
397 {
398 	int ihl = skb->data - skb_transport_header(skb);
399 
400 	if (skb->transport_header != skb->network_header) {
401 		memmove(skb_transport_header(skb),
402 			skb_network_header(skb), ihl);
403 		skb->network_header = skb->transport_header;
404 	}
405 	ip_hdr(skb)->tot_len = htons(skb->len + ihl);
406 	skb_reset_transport_header(skb);
407 	return 0;
408 }
409 
xfrm6_transport_input(struct xfrm_state * x,struct sk_buff * skb)410 static int xfrm6_transport_input(struct xfrm_state *x, struct sk_buff *skb)
411 {
412 #if IS_ENABLED(CONFIG_IPV6)
413 	int ihl = skb->data - skb_transport_header(skb);
414 
415 	if (skb->transport_header != skb->network_header) {
416 		memmove(skb_transport_header(skb),
417 			skb_network_header(skb), ihl);
418 		skb->network_header = skb->transport_header;
419 	}
420 	ipv6_hdr(skb)->payload_len = htons(skb->len + ihl -
421 					   sizeof(struct ipv6hdr));
422 	skb_reset_transport_header(skb);
423 	return 0;
424 #else
425 	WARN_ON_ONCE(1);
426 	return -EAFNOSUPPORT;
427 #endif
428 }
429 
xfrm_inner_mode_input(struct xfrm_state * x,const struct xfrm_mode * inner_mode,struct sk_buff * skb)430 static int xfrm_inner_mode_input(struct xfrm_state *x,
431 				 const struct xfrm_mode *inner_mode,
432 				 struct sk_buff *skb)
433 {
434 	switch (inner_mode->encap) {
435 	case XFRM_MODE_BEET:
436 	case XFRM_MODE_TUNNEL:
437 		return xfrm_prepare_input(x, skb);
438 	case XFRM_MODE_TRANSPORT:
439 		if (inner_mode->family == AF_INET)
440 			return xfrm4_transport_input(x, skb);
441 		if (inner_mode->family == AF_INET6)
442 			return xfrm6_transport_input(x, skb);
443 		break;
444 	case XFRM_MODE_ROUTEOPTIMIZATION:
445 		WARN_ON_ONCE(1);
446 		break;
447 	default:
448 		WARN_ON_ONCE(1);
449 		break;
450 	}
451 
452 	return -EOPNOTSUPP;
453 }
454 
xfrm_input(struct sk_buff * skb,int nexthdr,__be32 spi,int encap_type)455 int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
456 {
457 	const struct xfrm_state_afinfo *afinfo;
458 	struct net *net = dev_net(skb->dev);
459 	const struct xfrm_mode *inner_mode;
460 	int err;
461 	__be32 seq;
462 	__be32 seq_hi;
463 	struct xfrm_state *x = NULL;
464 	xfrm_address_t *daddr;
465 	u32 mark = skb->mark;
466 	unsigned int family = AF_UNSPEC;
467 	int decaps = 0;
468 	int async = 0;
469 	bool xfrm_gro = false;
470 	bool crypto_done = false;
471 	struct xfrm_offload *xo = xfrm_offload(skb);
472 	struct sec_path *sp;
473 
474 	if (encap_type < 0) {
475 		x = xfrm_input_state(skb);
476 
477 		if (unlikely(x->km.state != XFRM_STATE_VALID)) {
478 			if (x->km.state == XFRM_STATE_ACQ)
479 				XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR);
480 			else
481 				XFRM_INC_STATS(net,
482 					       LINUX_MIB_XFRMINSTATEINVALID);
483 
484 			if (encap_type == -1)
485 				dev_put(skb->dev);
486 			goto drop;
487 		}
488 
489 		family = x->outer_mode.family;
490 
491 		/* An encap_type of -1 indicates async resumption. */
492 		if (encap_type == -1) {
493 			async = 1;
494 			seq = XFRM_SKB_CB(skb)->seq.input.low;
495 			goto resume;
496 		}
497 
498 		/* encap_type < -1 indicates a GRO call. */
499 		encap_type = 0;
500 		seq = XFRM_SPI_SKB_CB(skb)->seq;
501 
502 		if (xo && (xo->flags & CRYPTO_DONE)) {
503 			crypto_done = true;
504 			family = XFRM_SPI_SKB_CB(skb)->family;
505 
506 			if (!(xo->status & CRYPTO_SUCCESS)) {
507 				if (xo->status &
508 				    (CRYPTO_TRANSPORT_AH_AUTH_FAILED |
509 				     CRYPTO_TRANSPORT_ESP_AUTH_FAILED |
510 				     CRYPTO_TUNNEL_AH_AUTH_FAILED |
511 				     CRYPTO_TUNNEL_ESP_AUTH_FAILED)) {
512 
513 					xfrm_audit_state_icvfail(x, skb,
514 								 x->type->proto);
515 					x->stats.integrity_failed++;
516 					XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
517 					goto drop;
518 				}
519 
520 				if (xo->status & CRYPTO_INVALID_PROTOCOL) {
521 					XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
522 					goto drop;
523 				}
524 
525 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
526 				goto drop;
527 			}
528 
529 			if ((err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0) {
530 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
531 				goto drop;
532 			}
533 		}
534 
535 		goto lock;
536 	}
537 
538 	family = XFRM_SPI_SKB_CB(skb)->family;
539 
540 	/* if tunnel is present override skb->mark value with tunnel i_key */
541 	switch (family) {
542 	case AF_INET:
543 		if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4)
544 			mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4->parms.i_key);
545 		break;
546 	case AF_INET6:
547 		if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6)
548 			mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6->parms.i_key);
549 		break;
550 	}
551 
552 	sp = secpath_set(skb);
553 	if (!sp) {
554 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
555 		goto drop;
556 	}
557 
558 	seq = 0;
559 	if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0) {
560 		secpath_reset(skb);
561 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
562 		goto drop;
563 	}
564 
565 	daddr = (xfrm_address_t *)(skb_network_header(skb) +
566 				   XFRM_SPI_SKB_CB(skb)->daddroff);
567 	do {
568 		sp = skb_sec_path(skb);
569 
570 		if (sp->len == XFRM_MAX_DEPTH) {
571 			secpath_reset(skb);
572 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
573 			goto drop;
574 		}
575 
576 		x = xfrm_state_lookup(net, mark, daddr, spi, nexthdr, family);
577 		if (x == NULL) {
578 			secpath_reset(skb);
579 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
580 			xfrm_audit_state_notfound(skb, family, spi, seq);
581 			goto drop;
582 		}
583 
584 		skb->mark = xfrm_smark_get(skb->mark, x);
585 
586 		sp->xvec[sp->len++] = x;
587 
588 		skb_dst_force(skb);
589 		if (!skb_dst(skb)) {
590 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
591 			goto drop;
592 		}
593 
594 lock:
595 		spin_lock(&x->lock);
596 
597 		if (unlikely(x->km.state != XFRM_STATE_VALID)) {
598 			if (x->km.state == XFRM_STATE_ACQ)
599 				XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR);
600 			else
601 				XFRM_INC_STATS(net,
602 					       LINUX_MIB_XFRMINSTATEINVALID);
603 			goto drop_unlock;
604 		}
605 
606 		if ((x->encap ? x->encap->encap_type : 0) != encap_type) {
607 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
608 			goto drop_unlock;
609 		}
610 
611 		if (x->repl->check(x, skb, seq)) {
612 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
613 			goto drop_unlock;
614 		}
615 
616 		if (xfrm_state_check_expire(x)) {
617 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEEXPIRED);
618 			goto drop_unlock;
619 		}
620 
621 		spin_unlock(&x->lock);
622 
623 		if (xfrm_tunnel_check(skb, x, family)) {
624 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
625 			goto drop;
626 		}
627 
628 		seq_hi = htonl(xfrm_replay_seqhi(x, seq));
629 
630 		XFRM_SKB_CB(skb)->seq.input.low = seq;
631 		XFRM_SKB_CB(skb)->seq.input.hi = seq_hi;
632 
633 		dev_hold(skb->dev);
634 
635 		if (crypto_done)
636 			nexthdr = x->type_offload->input_tail(x, skb);
637 		else
638 			nexthdr = x->type->input(x, skb);
639 
640 		if (nexthdr == -EINPROGRESS)
641 			return 0;
642 resume:
643 		dev_put(skb->dev);
644 
645 		spin_lock(&x->lock);
646 		if (nexthdr <= 0) {
647 			if (nexthdr == -EBADMSG) {
648 				xfrm_audit_state_icvfail(x, skb,
649 							 x->type->proto);
650 				x->stats.integrity_failed++;
651 			}
652 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
653 			goto drop_unlock;
654 		}
655 
656 		/* only the first xfrm gets the encap type */
657 		encap_type = 0;
658 
659 		if (async && x->repl->recheck(x, skb, seq)) {
660 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
661 			goto drop_unlock;
662 		}
663 
664 		x->repl->advance(x, seq);
665 
666 		x->curlft.bytes += skb->len;
667 		x->curlft.packets++;
668 
669 		spin_unlock(&x->lock);
670 
671 		XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;
672 
673 		inner_mode = &x->inner_mode;
674 
675 		if (x->sel.family == AF_UNSPEC) {
676 			inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
677 			if (inner_mode == NULL) {
678 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
679 				goto drop;
680 			}
681 		}
682 
683 		if (xfrm_inner_mode_input(x, inner_mode, skb)) {
684 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
685 			goto drop;
686 		}
687 
688 		if (x->outer_mode.flags & XFRM_MODE_FLAG_TUNNEL) {
689 			decaps = 1;
690 			break;
691 		}
692 
693 		/*
694 		 * We need the inner address.  However, we only get here for
695 		 * transport mode so the outer address is identical.
696 		 */
697 		daddr = &x->id.daddr;
698 		family = x->outer_mode.family;
699 
700 		err = xfrm_parse_spi(skb, nexthdr, &spi, &seq);
701 		if (err < 0) {
702 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
703 			goto drop;
704 		}
705 		crypto_done = false;
706 	} while (!err);
707 
708 	err = xfrm_rcv_cb(skb, family, x->type->proto, 0);
709 	if (err)
710 		goto drop;
711 
712 	nf_reset_ct(skb);
713 
714 	if (decaps) {
715 		sp = skb_sec_path(skb);
716 		if (sp)
717 			sp->olen = 0;
718 		skb_dst_drop(skb);
719 		gro_cells_receive(&gro_cells, skb);
720 		return 0;
721 	} else {
722 		xo = xfrm_offload(skb);
723 		if (xo)
724 			xfrm_gro = xo->flags & XFRM_GRO;
725 
726 		err = -EAFNOSUPPORT;
727 		rcu_read_lock();
728 		afinfo = xfrm_state_afinfo_get_rcu(x->inner_mode.family);
729 		if (likely(afinfo))
730 			err = afinfo->transport_finish(skb, xfrm_gro || async);
731 		rcu_read_unlock();
732 		if (xfrm_gro) {
733 			sp = skb_sec_path(skb);
734 			if (sp)
735 				sp->olen = 0;
736 			skb_dst_drop(skb);
737 			gro_cells_receive(&gro_cells, skb);
738 			return err;
739 		}
740 
741 		return err;
742 	}
743 
744 drop_unlock:
745 	spin_unlock(&x->lock);
746 drop:
747 	xfrm_rcv_cb(skb, family, x && x->type ? x->type->proto : nexthdr, -1);
748 	kfree_skb(skb);
749 	return 0;
750 }
751 EXPORT_SYMBOL(xfrm_input);
752 
xfrm_input_resume(struct sk_buff * skb,int nexthdr)753 int xfrm_input_resume(struct sk_buff *skb, int nexthdr)
754 {
755 	return xfrm_input(skb, nexthdr, 0, -1);
756 }
757 EXPORT_SYMBOL(xfrm_input_resume);
758 
xfrm_trans_reinject(unsigned long data)759 static void xfrm_trans_reinject(unsigned long data)
760 {
761 	struct xfrm_trans_tasklet *trans = (void *)data;
762 	struct sk_buff_head queue;
763 	struct sk_buff *skb;
764 
765 	__skb_queue_head_init(&queue);
766 	skb_queue_splice_init(&trans->queue, &queue);
767 
768 	while ((skb = __skb_dequeue(&queue)))
769 		XFRM_TRANS_SKB_CB(skb)->finish(dev_net(skb->dev), NULL, skb);
770 }
771 
xfrm_trans_queue(struct sk_buff * skb,int (* finish)(struct net *,struct sock *,struct sk_buff *))772 int xfrm_trans_queue(struct sk_buff *skb,
773 		     int (*finish)(struct net *, struct sock *,
774 				   struct sk_buff *))
775 {
776 	struct xfrm_trans_tasklet *trans;
777 
778 	trans = this_cpu_ptr(&xfrm_trans_tasklet);
779 
780 	if (skb_queue_len(&trans->queue) >= netdev_max_backlog)
781 		return -ENOBUFS;
782 
783 	XFRM_TRANS_SKB_CB(skb)->finish = finish;
784 	__skb_queue_tail(&trans->queue, skb);
785 	tasklet_schedule(&trans->tasklet);
786 	return 0;
787 }
788 EXPORT_SYMBOL(xfrm_trans_queue);
789 
xfrm_input_init(void)790 void __init xfrm_input_init(void)
791 {
792 	int err;
793 	int i;
794 
795 	init_dummy_netdev(&xfrm_napi_dev);
796 	err = gro_cells_init(&gro_cells, &xfrm_napi_dev);
797 	if (err)
798 		gro_cells.cells = NULL;
799 
800 	for_each_possible_cpu(i) {
801 		struct xfrm_trans_tasklet *trans;
802 
803 		trans = &per_cpu(xfrm_trans_tasklet, i);
804 		__skb_queue_head_init(&trans->queue);
805 		tasklet_init(&trans->tasklet, xfrm_trans_reinject,
806 			     (unsigned long)trans);
807 	}
808 }
809