xref: /openbmc/linux/net/xfrm/xfrm_policy.c (revision f7d84fa7)
1 /*
2  * xfrm_policy.c
3  *
4  * Changes:
5  *	Mitsuru KANDA @USAGI
6  * 	Kazunori MIYAZAWA @USAGI
7  * 	Kunihiro Ishiguro <kunihiro@ipinfusion.com>
8  * 		IPv6 support
9  * 	Kazunori MIYAZAWA @USAGI
10  * 	YOSHIFUJI Hideaki
11  * 		Split up af-specific portion
12  *	Derek Atkins <derek@ihtfp.com>		Add the post_input processor
13  *
14  */
15 
16 #include <linux/err.h>
17 #include <linux/slab.h>
18 #include <linux/kmod.h>
19 #include <linux/list.h>
20 #include <linux/spinlock.h>
21 #include <linux/workqueue.h>
22 #include <linux/notifier.h>
23 #include <linux/netdevice.h>
24 #include <linux/netfilter.h>
25 #include <linux/module.h>
26 #include <linux/cache.h>
27 #include <linux/audit.h>
28 #include <net/dst.h>
29 #include <net/flow.h>
30 #include <net/xfrm.h>
31 #include <net/ip.h>
32 #ifdef CONFIG_XFRM_STATISTICS
33 #include <net/snmp.h>
34 #endif
35 
36 #include "xfrm_hash.h"
37 
38 #define XFRM_QUEUE_TMO_MIN ((unsigned)(HZ/10))
39 #define XFRM_QUEUE_TMO_MAX ((unsigned)(60*HZ))
40 #define XFRM_MAX_QUEUE_LEN	100
41 
42 struct xfrm_flo {
43 	struct dst_entry *dst_orig;
44 	u8 flags;
45 };
46 
47 static DEFINE_SPINLOCK(xfrm_policy_afinfo_lock);
48 static struct xfrm_policy_afinfo const __rcu *xfrm_policy_afinfo[AF_INET6 + 1]
49 						__read_mostly;
50 
51 static struct kmem_cache *xfrm_dst_cache __read_mostly;
52 static __read_mostly seqcount_t xfrm_policy_hash_generation;
53 
54 static void xfrm_init_pmtu(struct dst_entry *dst);
55 static int stale_bundle(struct dst_entry *dst);
56 static int xfrm_bundle_ok(struct xfrm_dst *xdst);
57 static void xfrm_policy_queue_process(unsigned long arg);
58 
59 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir);
60 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
61 						int dir);
62 
63 static inline bool xfrm_pol_hold_rcu(struct xfrm_policy *policy)
64 {
65 	return atomic_inc_not_zero(&policy->refcnt);
66 }
67 
68 static inline bool
69 __xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
70 {
71 	const struct flowi4 *fl4 = &fl->u.ip4;
72 
73 	return  addr4_match(fl4->daddr, sel->daddr.a4, sel->prefixlen_d) &&
74 		addr4_match(fl4->saddr, sel->saddr.a4, sel->prefixlen_s) &&
75 		!((xfrm_flowi_dport(fl, &fl4->uli) ^ sel->dport) & sel->dport_mask) &&
76 		!((xfrm_flowi_sport(fl, &fl4->uli) ^ sel->sport) & sel->sport_mask) &&
77 		(fl4->flowi4_proto == sel->proto || !sel->proto) &&
78 		(fl4->flowi4_oif == sel->ifindex || !sel->ifindex);
79 }
80 
81 static inline bool
82 __xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
83 {
84 	const struct flowi6 *fl6 = &fl->u.ip6;
85 
86 	return  addr_match(&fl6->daddr, &sel->daddr, sel->prefixlen_d) &&
87 		addr_match(&fl6->saddr, &sel->saddr, sel->prefixlen_s) &&
88 		!((xfrm_flowi_dport(fl, &fl6->uli) ^ sel->dport) & sel->dport_mask) &&
89 		!((xfrm_flowi_sport(fl, &fl6->uli) ^ sel->sport) & sel->sport_mask) &&
90 		(fl6->flowi6_proto == sel->proto || !sel->proto) &&
91 		(fl6->flowi6_oif == sel->ifindex || !sel->ifindex);
92 }
93 
94 bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl,
95 			 unsigned short family)
96 {
97 	switch (family) {
98 	case AF_INET:
99 		return __xfrm4_selector_match(sel, fl);
100 	case AF_INET6:
101 		return __xfrm6_selector_match(sel, fl);
102 	}
103 	return false;
104 }
105 
106 static const struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
107 {
108 	const struct xfrm_policy_afinfo *afinfo;
109 
110 	if (unlikely(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
111 		return NULL;
112 	rcu_read_lock();
113 	afinfo = rcu_dereference(xfrm_policy_afinfo[family]);
114 	if (unlikely(!afinfo))
115 		rcu_read_unlock();
116 	return afinfo;
117 }
118 
119 struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos, int oif,
120 				    const xfrm_address_t *saddr,
121 				    const xfrm_address_t *daddr,
122 				    int family)
123 {
124 	const struct xfrm_policy_afinfo *afinfo;
125 	struct dst_entry *dst;
126 
127 	afinfo = xfrm_policy_get_afinfo(family);
128 	if (unlikely(afinfo == NULL))
129 		return ERR_PTR(-EAFNOSUPPORT);
130 
131 	dst = afinfo->dst_lookup(net, tos, oif, saddr, daddr);
132 
133 	rcu_read_unlock();
134 
135 	return dst;
136 }
137 EXPORT_SYMBOL(__xfrm_dst_lookup);
138 
139 static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x,
140 						int tos, int oif,
141 						xfrm_address_t *prev_saddr,
142 						xfrm_address_t *prev_daddr,
143 						int family)
144 {
145 	struct net *net = xs_net(x);
146 	xfrm_address_t *saddr = &x->props.saddr;
147 	xfrm_address_t *daddr = &x->id.daddr;
148 	struct dst_entry *dst;
149 
150 	if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) {
151 		saddr = x->coaddr;
152 		daddr = prev_daddr;
153 	}
154 	if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) {
155 		saddr = prev_saddr;
156 		daddr = x->coaddr;
157 	}
158 
159 	dst = __xfrm_dst_lookup(net, tos, oif, saddr, daddr, family);
160 
161 	if (!IS_ERR(dst)) {
162 		if (prev_saddr != saddr)
163 			memcpy(prev_saddr, saddr,  sizeof(*prev_saddr));
164 		if (prev_daddr != daddr)
165 			memcpy(prev_daddr, daddr,  sizeof(*prev_daddr));
166 	}
167 
168 	return dst;
169 }
170 
171 static inline unsigned long make_jiffies(long secs)
172 {
173 	if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
174 		return MAX_SCHEDULE_TIMEOUT-1;
175 	else
176 		return secs*HZ;
177 }
178 
179 static void xfrm_policy_timer(unsigned long data)
180 {
181 	struct xfrm_policy *xp = (struct xfrm_policy *)data;
182 	unsigned long now = get_seconds();
183 	long next = LONG_MAX;
184 	int warn = 0;
185 	int dir;
186 
187 	read_lock(&xp->lock);
188 
189 	if (unlikely(xp->walk.dead))
190 		goto out;
191 
192 	dir = xfrm_policy_id2dir(xp->index);
193 
194 	if (xp->lft.hard_add_expires_seconds) {
195 		long tmo = xp->lft.hard_add_expires_seconds +
196 			xp->curlft.add_time - now;
197 		if (tmo <= 0)
198 			goto expired;
199 		if (tmo < next)
200 			next = tmo;
201 	}
202 	if (xp->lft.hard_use_expires_seconds) {
203 		long tmo = xp->lft.hard_use_expires_seconds +
204 			(xp->curlft.use_time ? : xp->curlft.add_time) - now;
205 		if (tmo <= 0)
206 			goto expired;
207 		if (tmo < next)
208 			next = tmo;
209 	}
210 	if (xp->lft.soft_add_expires_seconds) {
211 		long tmo = xp->lft.soft_add_expires_seconds +
212 			xp->curlft.add_time - now;
213 		if (tmo <= 0) {
214 			warn = 1;
215 			tmo = XFRM_KM_TIMEOUT;
216 		}
217 		if (tmo < next)
218 			next = tmo;
219 	}
220 	if (xp->lft.soft_use_expires_seconds) {
221 		long tmo = xp->lft.soft_use_expires_seconds +
222 			(xp->curlft.use_time ? : xp->curlft.add_time) - now;
223 		if (tmo <= 0) {
224 			warn = 1;
225 			tmo = XFRM_KM_TIMEOUT;
226 		}
227 		if (tmo < next)
228 			next = tmo;
229 	}
230 
231 	if (warn)
232 		km_policy_expired(xp, dir, 0, 0);
233 	if (next != LONG_MAX &&
234 	    !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
235 		xfrm_pol_hold(xp);
236 
237 out:
238 	read_unlock(&xp->lock);
239 	xfrm_pol_put(xp);
240 	return;
241 
242 expired:
243 	read_unlock(&xp->lock);
244 	if (!xfrm_policy_delete(xp, dir))
245 		km_policy_expired(xp, dir, 1, 0);
246 	xfrm_pol_put(xp);
247 }
248 
249 static struct flow_cache_object *xfrm_policy_flo_get(struct flow_cache_object *flo)
250 {
251 	struct xfrm_policy *pol = container_of(flo, struct xfrm_policy, flo);
252 
253 	if (unlikely(pol->walk.dead))
254 		flo = NULL;
255 	else
256 		xfrm_pol_hold(pol);
257 
258 	return flo;
259 }
260 
261 static int xfrm_policy_flo_check(struct flow_cache_object *flo)
262 {
263 	struct xfrm_policy *pol = container_of(flo, struct xfrm_policy, flo);
264 
265 	return !pol->walk.dead;
266 }
267 
268 static void xfrm_policy_flo_delete(struct flow_cache_object *flo)
269 {
270 	xfrm_pol_put(container_of(flo, struct xfrm_policy, flo));
271 }
272 
273 static const struct flow_cache_ops xfrm_policy_fc_ops = {
274 	.get = xfrm_policy_flo_get,
275 	.check = xfrm_policy_flo_check,
276 	.delete = xfrm_policy_flo_delete,
277 };
278 
279 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
280  * SPD calls.
281  */
282 
283 struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
284 {
285 	struct xfrm_policy *policy;
286 
287 	policy = kzalloc(sizeof(struct xfrm_policy), gfp);
288 
289 	if (policy) {
290 		write_pnet(&policy->xp_net, net);
291 		INIT_LIST_HEAD(&policy->walk.all);
292 		INIT_HLIST_NODE(&policy->bydst);
293 		INIT_HLIST_NODE(&policy->byidx);
294 		rwlock_init(&policy->lock);
295 		atomic_set(&policy->refcnt, 1);
296 		skb_queue_head_init(&policy->polq.hold_queue);
297 		setup_timer(&policy->timer, xfrm_policy_timer,
298 				(unsigned long)policy);
299 		setup_timer(&policy->polq.hold_timer, xfrm_policy_queue_process,
300 			    (unsigned long)policy);
301 		policy->flo.ops = &xfrm_policy_fc_ops;
302 	}
303 	return policy;
304 }
305 EXPORT_SYMBOL(xfrm_policy_alloc);
306 
307 static void xfrm_policy_destroy_rcu(struct rcu_head *head)
308 {
309 	struct xfrm_policy *policy = container_of(head, struct xfrm_policy, rcu);
310 
311 	security_xfrm_policy_free(policy->security);
312 	kfree(policy);
313 }
314 
315 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
316 
317 void xfrm_policy_destroy(struct xfrm_policy *policy)
318 {
319 	BUG_ON(!policy->walk.dead);
320 
321 	if (del_timer(&policy->timer) || del_timer(&policy->polq.hold_timer))
322 		BUG();
323 
324 	call_rcu(&policy->rcu, xfrm_policy_destroy_rcu);
325 }
326 EXPORT_SYMBOL(xfrm_policy_destroy);
327 
328 /* Rule must be locked. Release descendant resources, announce
329  * entry dead. The rule must be unlinked from lists to the moment.
330  */
331 
332 static void xfrm_policy_kill(struct xfrm_policy *policy)
333 {
334 	policy->walk.dead = 1;
335 
336 	atomic_inc(&policy->genid);
337 
338 	if (del_timer(&policy->polq.hold_timer))
339 		xfrm_pol_put(policy);
340 	skb_queue_purge(&policy->polq.hold_queue);
341 
342 	if (del_timer(&policy->timer))
343 		xfrm_pol_put(policy);
344 
345 	xfrm_pol_put(policy);
346 }
347 
348 static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
349 
350 static inline unsigned int idx_hash(struct net *net, u32 index)
351 {
352 	return __idx_hash(index, net->xfrm.policy_idx_hmask);
353 }
354 
355 /* calculate policy hash thresholds */
356 static void __get_hash_thresh(struct net *net,
357 			      unsigned short family, int dir,
358 			      u8 *dbits, u8 *sbits)
359 {
360 	switch (family) {
361 	case AF_INET:
362 		*dbits = net->xfrm.policy_bydst[dir].dbits4;
363 		*sbits = net->xfrm.policy_bydst[dir].sbits4;
364 		break;
365 
366 	case AF_INET6:
367 		*dbits = net->xfrm.policy_bydst[dir].dbits6;
368 		*sbits = net->xfrm.policy_bydst[dir].sbits6;
369 		break;
370 
371 	default:
372 		*dbits = 0;
373 		*sbits = 0;
374 	}
375 }
376 
377 static struct hlist_head *policy_hash_bysel(struct net *net,
378 					    const struct xfrm_selector *sel,
379 					    unsigned short family, int dir)
380 {
381 	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
382 	unsigned int hash;
383 	u8 dbits;
384 	u8 sbits;
385 
386 	__get_hash_thresh(net, family, dir, &dbits, &sbits);
387 	hash = __sel_hash(sel, family, hmask, dbits, sbits);
388 
389 	if (hash == hmask + 1)
390 		return &net->xfrm.policy_inexact[dir];
391 
392 	return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
393 		     lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
394 }
395 
396 static struct hlist_head *policy_hash_direct(struct net *net,
397 					     const xfrm_address_t *daddr,
398 					     const xfrm_address_t *saddr,
399 					     unsigned short family, int dir)
400 {
401 	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
402 	unsigned int hash;
403 	u8 dbits;
404 	u8 sbits;
405 
406 	__get_hash_thresh(net, family, dir, &dbits, &sbits);
407 	hash = __addr_hash(daddr, saddr, family, hmask, dbits, sbits);
408 
409 	return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
410 		     lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
411 }
412 
413 static void xfrm_dst_hash_transfer(struct net *net,
414 				   struct hlist_head *list,
415 				   struct hlist_head *ndsttable,
416 				   unsigned int nhashmask,
417 				   int dir)
418 {
419 	struct hlist_node *tmp, *entry0 = NULL;
420 	struct xfrm_policy *pol;
421 	unsigned int h0 = 0;
422 	u8 dbits;
423 	u8 sbits;
424 
425 redo:
426 	hlist_for_each_entry_safe(pol, tmp, list, bydst) {
427 		unsigned int h;
428 
429 		__get_hash_thresh(net, pol->family, dir, &dbits, &sbits);
430 		h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
431 				pol->family, nhashmask, dbits, sbits);
432 		if (!entry0) {
433 			hlist_del_rcu(&pol->bydst);
434 			hlist_add_head_rcu(&pol->bydst, ndsttable + h);
435 			h0 = h;
436 		} else {
437 			if (h != h0)
438 				continue;
439 			hlist_del_rcu(&pol->bydst);
440 			hlist_add_behind_rcu(&pol->bydst, entry0);
441 		}
442 		entry0 = &pol->bydst;
443 	}
444 	if (!hlist_empty(list)) {
445 		entry0 = NULL;
446 		goto redo;
447 	}
448 }
449 
450 static void xfrm_idx_hash_transfer(struct hlist_head *list,
451 				   struct hlist_head *nidxtable,
452 				   unsigned int nhashmask)
453 {
454 	struct hlist_node *tmp;
455 	struct xfrm_policy *pol;
456 
457 	hlist_for_each_entry_safe(pol, tmp, list, byidx) {
458 		unsigned int h;
459 
460 		h = __idx_hash(pol->index, nhashmask);
461 		hlist_add_head(&pol->byidx, nidxtable+h);
462 	}
463 }
464 
465 static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
466 {
467 	return ((old_hmask + 1) << 1) - 1;
468 }
469 
470 static void xfrm_bydst_resize(struct net *net, int dir)
471 {
472 	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
473 	unsigned int nhashmask = xfrm_new_hash_mask(hmask);
474 	unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
475 	struct hlist_head *ndst = xfrm_hash_alloc(nsize);
476 	struct hlist_head *odst;
477 	int i;
478 
479 	if (!ndst)
480 		return;
481 
482 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
483 	write_seqcount_begin(&xfrm_policy_hash_generation);
484 
485 	odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
486 				lockdep_is_held(&net->xfrm.xfrm_policy_lock));
487 
488 	odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
489 				lockdep_is_held(&net->xfrm.xfrm_policy_lock));
490 
491 	for (i = hmask; i >= 0; i--)
492 		xfrm_dst_hash_transfer(net, odst + i, ndst, nhashmask, dir);
493 
494 	rcu_assign_pointer(net->xfrm.policy_bydst[dir].table, ndst);
495 	net->xfrm.policy_bydst[dir].hmask = nhashmask;
496 
497 	write_seqcount_end(&xfrm_policy_hash_generation);
498 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
499 
500 	synchronize_rcu();
501 
502 	xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
503 }
504 
505 static void xfrm_byidx_resize(struct net *net, int total)
506 {
507 	unsigned int hmask = net->xfrm.policy_idx_hmask;
508 	unsigned int nhashmask = xfrm_new_hash_mask(hmask);
509 	unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
510 	struct hlist_head *oidx = net->xfrm.policy_byidx;
511 	struct hlist_head *nidx = xfrm_hash_alloc(nsize);
512 	int i;
513 
514 	if (!nidx)
515 		return;
516 
517 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
518 
519 	for (i = hmask; i >= 0; i--)
520 		xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
521 
522 	net->xfrm.policy_byidx = nidx;
523 	net->xfrm.policy_idx_hmask = nhashmask;
524 
525 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
526 
527 	xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
528 }
529 
530 static inline int xfrm_bydst_should_resize(struct net *net, int dir, int *total)
531 {
532 	unsigned int cnt = net->xfrm.policy_count[dir];
533 	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
534 
535 	if (total)
536 		*total += cnt;
537 
538 	if ((hmask + 1) < xfrm_policy_hashmax &&
539 	    cnt > hmask)
540 		return 1;
541 
542 	return 0;
543 }
544 
545 static inline int xfrm_byidx_should_resize(struct net *net, int total)
546 {
547 	unsigned int hmask = net->xfrm.policy_idx_hmask;
548 
549 	if ((hmask + 1) < xfrm_policy_hashmax &&
550 	    total > hmask)
551 		return 1;
552 
553 	return 0;
554 }
555 
556 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
557 {
558 	si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
559 	si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
560 	si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
561 	si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
562 	si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
563 	si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
564 	si->spdhcnt = net->xfrm.policy_idx_hmask;
565 	si->spdhmcnt = xfrm_policy_hashmax;
566 }
567 EXPORT_SYMBOL(xfrm_spd_getinfo);
568 
569 static DEFINE_MUTEX(hash_resize_mutex);
570 static void xfrm_hash_resize(struct work_struct *work)
571 {
572 	struct net *net = container_of(work, struct net, xfrm.policy_hash_work);
573 	int dir, total;
574 
575 	mutex_lock(&hash_resize_mutex);
576 
577 	total = 0;
578 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
579 		if (xfrm_bydst_should_resize(net, dir, &total))
580 			xfrm_bydst_resize(net, dir);
581 	}
582 	if (xfrm_byidx_should_resize(net, total))
583 		xfrm_byidx_resize(net, total);
584 
585 	mutex_unlock(&hash_resize_mutex);
586 }
587 
588 static void xfrm_hash_rebuild(struct work_struct *work)
589 {
590 	struct net *net = container_of(work, struct net,
591 				       xfrm.policy_hthresh.work);
592 	unsigned int hmask;
593 	struct xfrm_policy *pol;
594 	struct xfrm_policy *policy;
595 	struct hlist_head *chain;
596 	struct hlist_head *odst;
597 	struct hlist_node *newpos;
598 	int i;
599 	int dir;
600 	unsigned seq;
601 	u8 lbits4, rbits4, lbits6, rbits6;
602 
603 	mutex_lock(&hash_resize_mutex);
604 
605 	/* read selector prefixlen thresholds */
606 	do {
607 		seq = read_seqbegin(&net->xfrm.policy_hthresh.lock);
608 
609 		lbits4 = net->xfrm.policy_hthresh.lbits4;
610 		rbits4 = net->xfrm.policy_hthresh.rbits4;
611 		lbits6 = net->xfrm.policy_hthresh.lbits6;
612 		rbits6 = net->xfrm.policy_hthresh.rbits6;
613 	} while (read_seqretry(&net->xfrm.policy_hthresh.lock, seq));
614 
615 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
616 
617 	/* reset the bydst and inexact table in all directions */
618 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
619 		INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
620 		hmask = net->xfrm.policy_bydst[dir].hmask;
621 		odst = net->xfrm.policy_bydst[dir].table;
622 		for (i = hmask; i >= 0; i--)
623 			INIT_HLIST_HEAD(odst + i);
624 		if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
625 			/* dir out => dst = remote, src = local */
626 			net->xfrm.policy_bydst[dir].dbits4 = rbits4;
627 			net->xfrm.policy_bydst[dir].sbits4 = lbits4;
628 			net->xfrm.policy_bydst[dir].dbits6 = rbits6;
629 			net->xfrm.policy_bydst[dir].sbits6 = lbits6;
630 		} else {
631 			/* dir in/fwd => dst = local, src = remote */
632 			net->xfrm.policy_bydst[dir].dbits4 = lbits4;
633 			net->xfrm.policy_bydst[dir].sbits4 = rbits4;
634 			net->xfrm.policy_bydst[dir].dbits6 = lbits6;
635 			net->xfrm.policy_bydst[dir].sbits6 = rbits6;
636 		}
637 	}
638 
639 	/* re-insert all policies by order of creation */
640 	list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
641 		if (xfrm_policy_id2dir(policy->index) >= XFRM_POLICY_MAX) {
642 			/* skip socket policies */
643 			continue;
644 		}
645 		newpos = NULL;
646 		chain = policy_hash_bysel(net, &policy->selector,
647 					  policy->family,
648 					  xfrm_policy_id2dir(policy->index));
649 		hlist_for_each_entry(pol, chain, bydst) {
650 			if (policy->priority >= pol->priority)
651 				newpos = &pol->bydst;
652 			else
653 				break;
654 		}
655 		if (newpos)
656 			hlist_add_behind(&policy->bydst, newpos);
657 		else
658 			hlist_add_head(&policy->bydst, chain);
659 	}
660 
661 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
662 
663 	mutex_unlock(&hash_resize_mutex);
664 }
665 
666 void xfrm_policy_hash_rebuild(struct net *net)
667 {
668 	schedule_work(&net->xfrm.policy_hthresh.work);
669 }
670 EXPORT_SYMBOL(xfrm_policy_hash_rebuild);
671 
672 /* Generate new index... KAME seems to generate them ordered by cost
673  * of an absolute inpredictability of ordering of rules. This will not pass. */
674 static u32 xfrm_gen_index(struct net *net, int dir, u32 index)
675 {
676 	static u32 idx_generator;
677 
678 	for (;;) {
679 		struct hlist_head *list;
680 		struct xfrm_policy *p;
681 		u32 idx;
682 		int found;
683 
684 		if (!index) {
685 			idx = (idx_generator | dir);
686 			idx_generator += 8;
687 		} else {
688 			idx = index;
689 			index = 0;
690 		}
691 
692 		if (idx == 0)
693 			idx = 8;
694 		list = net->xfrm.policy_byidx + idx_hash(net, idx);
695 		found = 0;
696 		hlist_for_each_entry(p, list, byidx) {
697 			if (p->index == idx) {
698 				found = 1;
699 				break;
700 			}
701 		}
702 		if (!found)
703 			return idx;
704 	}
705 }
706 
707 static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
708 {
709 	u32 *p1 = (u32 *) s1;
710 	u32 *p2 = (u32 *) s2;
711 	int len = sizeof(struct xfrm_selector) / sizeof(u32);
712 	int i;
713 
714 	for (i = 0; i < len; i++) {
715 		if (p1[i] != p2[i])
716 			return 1;
717 	}
718 
719 	return 0;
720 }
721 
722 static void xfrm_policy_requeue(struct xfrm_policy *old,
723 				struct xfrm_policy *new)
724 {
725 	struct xfrm_policy_queue *pq = &old->polq;
726 	struct sk_buff_head list;
727 
728 	if (skb_queue_empty(&pq->hold_queue))
729 		return;
730 
731 	__skb_queue_head_init(&list);
732 
733 	spin_lock_bh(&pq->hold_queue.lock);
734 	skb_queue_splice_init(&pq->hold_queue, &list);
735 	if (del_timer(&pq->hold_timer))
736 		xfrm_pol_put(old);
737 	spin_unlock_bh(&pq->hold_queue.lock);
738 
739 	pq = &new->polq;
740 
741 	spin_lock_bh(&pq->hold_queue.lock);
742 	skb_queue_splice(&list, &pq->hold_queue);
743 	pq->timeout = XFRM_QUEUE_TMO_MIN;
744 	if (!mod_timer(&pq->hold_timer, jiffies))
745 		xfrm_pol_hold(new);
746 	spin_unlock_bh(&pq->hold_queue.lock);
747 }
748 
749 static bool xfrm_policy_mark_match(struct xfrm_policy *policy,
750 				   struct xfrm_policy *pol)
751 {
752 	u32 mark = policy->mark.v & policy->mark.m;
753 
754 	if (policy->mark.v == pol->mark.v && policy->mark.m == pol->mark.m)
755 		return true;
756 
757 	if ((mark & pol->mark.m) == pol->mark.v &&
758 	    policy->priority == pol->priority)
759 		return true;
760 
761 	return false;
762 }
763 
764 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
765 {
766 	struct net *net = xp_net(policy);
767 	struct xfrm_policy *pol;
768 	struct xfrm_policy *delpol;
769 	struct hlist_head *chain;
770 	struct hlist_node *newpos;
771 
772 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
773 	chain = policy_hash_bysel(net, &policy->selector, policy->family, dir);
774 	delpol = NULL;
775 	newpos = NULL;
776 	hlist_for_each_entry(pol, chain, bydst) {
777 		if (pol->type == policy->type &&
778 		    !selector_cmp(&pol->selector, &policy->selector) &&
779 		    xfrm_policy_mark_match(policy, pol) &&
780 		    xfrm_sec_ctx_match(pol->security, policy->security) &&
781 		    !WARN_ON(delpol)) {
782 			if (excl) {
783 				spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
784 				return -EEXIST;
785 			}
786 			delpol = pol;
787 			if (policy->priority > pol->priority)
788 				continue;
789 		} else if (policy->priority >= pol->priority) {
790 			newpos = &pol->bydst;
791 			continue;
792 		}
793 		if (delpol)
794 			break;
795 	}
796 	if (newpos)
797 		hlist_add_behind(&policy->bydst, newpos);
798 	else
799 		hlist_add_head(&policy->bydst, chain);
800 	__xfrm_policy_link(policy, dir);
801 	atomic_inc(&net->xfrm.flow_cache_genid);
802 
803 	/* After previous checking, family can either be AF_INET or AF_INET6 */
804 	if (policy->family == AF_INET)
805 		rt_genid_bump_ipv4(net);
806 	else
807 		rt_genid_bump_ipv6(net);
808 
809 	if (delpol) {
810 		xfrm_policy_requeue(delpol, policy);
811 		__xfrm_policy_unlink(delpol, dir);
812 	}
813 	policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir, policy->index);
814 	hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
815 	policy->curlft.add_time = get_seconds();
816 	policy->curlft.use_time = 0;
817 	if (!mod_timer(&policy->timer, jiffies + HZ))
818 		xfrm_pol_hold(policy);
819 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
820 
821 	if (delpol)
822 		xfrm_policy_kill(delpol);
823 	else if (xfrm_bydst_should_resize(net, dir, NULL))
824 		schedule_work(&net->xfrm.policy_hash_work);
825 
826 	return 0;
827 }
828 EXPORT_SYMBOL(xfrm_policy_insert);
829 
830 struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u8 type,
831 					  int dir, struct xfrm_selector *sel,
832 					  struct xfrm_sec_ctx *ctx, int delete,
833 					  int *err)
834 {
835 	struct xfrm_policy *pol, *ret;
836 	struct hlist_head *chain;
837 
838 	*err = 0;
839 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
840 	chain = policy_hash_bysel(net, sel, sel->family, dir);
841 	ret = NULL;
842 	hlist_for_each_entry(pol, chain, bydst) {
843 		if (pol->type == type &&
844 		    (mark & pol->mark.m) == pol->mark.v &&
845 		    !selector_cmp(sel, &pol->selector) &&
846 		    xfrm_sec_ctx_match(ctx, pol->security)) {
847 			xfrm_pol_hold(pol);
848 			if (delete) {
849 				*err = security_xfrm_policy_delete(
850 								pol->security);
851 				if (*err) {
852 					spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
853 					return pol;
854 				}
855 				__xfrm_policy_unlink(pol, dir);
856 			}
857 			ret = pol;
858 			break;
859 		}
860 	}
861 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
862 
863 	if (ret && delete)
864 		xfrm_policy_kill(ret);
865 	return ret;
866 }
867 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
868 
869 struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8 type,
870 				     int dir, u32 id, int delete, int *err)
871 {
872 	struct xfrm_policy *pol, *ret;
873 	struct hlist_head *chain;
874 
875 	*err = -ENOENT;
876 	if (xfrm_policy_id2dir(id) != dir)
877 		return NULL;
878 
879 	*err = 0;
880 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
881 	chain = net->xfrm.policy_byidx + idx_hash(net, id);
882 	ret = NULL;
883 	hlist_for_each_entry(pol, chain, byidx) {
884 		if (pol->type == type && pol->index == id &&
885 		    (mark & pol->mark.m) == pol->mark.v) {
886 			xfrm_pol_hold(pol);
887 			if (delete) {
888 				*err = security_xfrm_policy_delete(
889 								pol->security);
890 				if (*err) {
891 					spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
892 					return pol;
893 				}
894 				__xfrm_policy_unlink(pol, dir);
895 			}
896 			ret = pol;
897 			break;
898 		}
899 	}
900 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
901 
902 	if (ret && delete)
903 		xfrm_policy_kill(ret);
904 	return ret;
905 }
906 EXPORT_SYMBOL(xfrm_policy_byid);
907 
908 #ifdef CONFIG_SECURITY_NETWORK_XFRM
909 static inline int
910 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
911 {
912 	int dir, err = 0;
913 
914 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
915 		struct xfrm_policy *pol;
916 		int i;
917 
918 		hlist_for_each_entry(pol,
919 				     &net->xfrm.policy_inexact[dir], bydst) {
920 			if (pol->type != type)
921 				continue;
922 			err = security_xfrm_policy_delete(pol->security);
923 			if (err) {
924 				xfrm_audit_policy_delete(pol, 0, task_valid);
925 				return err;
926 			}
927 		}
928 		for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
929 			hlist_for_each_entry(pol,
930 					     net->xfrm.policy_bydst[dir].table + i,
931 					     bydst) {
932 				if (pol->type != type)
933 					continue;
934 				err = security_xfrm_policy_delete(
935 								pol->security);
936 				if (err) {
937 					xfrm_audit_policy_delete(pol, 0,
938 								 task_valid);
939 					return err;
940 				}
941 			}
942 		}
943 	}
944 	return err;
945 }
946 #else
947 static inline int
948 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
949 {
950 	return 0;
951 }
952 #endif
953 
954 int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
955 {
956 	int dir, err = 0, cnt = 0;
957 
958 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
959 
960 	err = xfrm_policy_flush_secctx_check(net, type, task_valid);
961 	if (err)
962 		goto out;
963 
964 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
965 		struct xfrm_policy *pol;
966 		int i;
967 
968 	again1:
969 		hlist_for_each_entry(pol,
970 				     &net->xfrm.policy_inexact[dir], bydst) {
971 			if (pol->type != type)
972 				continue;
973 			__xfrm_policy_unlink(pol, dir);
974 			spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
975 			cnt++;
976 
977 			xfrm_audit_policy_delete(pol, 1, task_valid);
978 
979 			xfrm_policy_kill(pol);
980 
981 			spin_lock_bh(&net->xfrm.xfrm_policy_lock);
982 			goto again1;
983 		}
984 
985 		for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
986 	again2:
987 			hlist_for_each_entry(pol,
988 					     net->xfrm.policy_bydst[dir].table + i,
989 					     bydst) {
990 				if (pol->type != type)
991 					continue;
992 				__xfrm_policy_unlink(pol, dir);
993 				spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
994 				cnt++;
995 
996 				xfrm_audit_policy_delete(pol, 1, task_valid);
997 				xfrm_policy_kill(pol);
998 
999 				spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1000 				goto again2;
1001 			}
1002 		}
1003 
1004 	}
1005 	if (!cnt)
1006 		err = -ESRCH;
1007 out:
1008 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1009 
1010 	if (cnt)
1011 		xfrm_garbage_collect(net);
1012 
1013 	return err;
1014 }
1015 EXPORT_SYMBOL(xfrm_policy_flush);
1016 
1017 int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
1018 		     int (*func)(struct xfrm_policy *, int, int, void*),
1019 		     void *data)
1020 {
1021 	struct xfrm_policy *pol;
1022 	struct xfrm_policy_walk_entry *x;
1023 	int error = 0;
1024 
1025 	if (walk->type >= XFRM_POLICY_TYPE_MAX &&
1026 	    walk->type != XFRM_POLICY_TYPE_ANY)
1027 		return -EINVAL;
1028 
1029 	if (list_empty(&walk->walk.all) && walk->seq != 0)
1030 		return 0;
1031 
1032 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1033 	if (list_empty(&walk->walk.all))
1034 		x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
1035 	else
1036 		x = list_first_entry(&walk->walk.all,
1037 				     struct xfrm_policy_walk_entry, all);
1038 
1039 	list_for_each_entry_from(x, &net->xfrm.policy_all, all) {
1040 		if (x->dead)
1041 			continue;
1042 		pol = container_of(x, struct xfrm_policy, walk);
1043 		if (walk->type != XFRM_POLICY_TYPE_ANY &&
1044 		    walk->type != pol->type)
1045 			continue;
1046 		error = func(pol, xfrm_policy_id2dir(pol->index),
1047 			     walk->seq, data);
1048 		if (error) {
1049 			list_move_tail(&walk->walk.all, &x->all);
1050 			goto out;
1051 		}
1052 		walk->seq++;
1053 	}
1054 	if (walk->seq == 0) {
1055 		error = -ENOENT;
1056 		goto out;
1057 	}
1058 	list_del_init(&walk->walk.all);
1059 out:
1060 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1061 	return error;
1062 }
1063 EXPORT_SYMBOL(xfrm_policy_walk);
1064 
1065 void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type)
1066 {
1067 	INIT_LIST_HEAD(&walk->walk.all);
1068 	walk->walk.dead = 1;
1069 	walk->type = type;
1070 	walk->seq = 0;
1071 }
1072 EXPORT_SYMBOL(xfrm_policy_walk_init);
1073 
1074 void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net)
1075 {
1076 	if (list_empty(&walk->walk.all))
1077 		return;
1078 
1079 	spin_lock_bh(&net->xfrm.xfrm_policy_lock); /*FIXME where is net? */
1080 	list_del(&walk->walk.all);
1081 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1082 }
1083 EXPORT_SYMBOL(xfrm_policy_walk_done);
1084 
1085 /*
1086  * Find policy to apply to this flow.
1087  *
1088  * Returns 0 if policy found, else an -errno.
1089  */
1090 static int xfrm_policy_match(const struct xfrm_policy *pol,
1091 			     const struct flowi *fl,
1092 			     u8 type, u16 family, int dir)
1093 {
1094 	const struct xfrm_selector *sel = &pol->selector;
1095 	int ret = -ESRCH;
1096 	bool match;
1097 
1098 	if (pol->family != family ||
1099 	    (fl->flowi_mark & pol->mark.m) != pol->mark.v ||
1100 	    pol->type != type)
1101 		return ret;
1102 
1103 	match = xfrm_selector_match(sel, fl, family);
1104 	if (match)
1105 		ret = security_xfrm_policy_lookup(pol->security, fl->flowi_secid,
1106 						  dir);
1107 
1108 	return ret;
1109 }
1110 
1111 static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
1112 						     const struct flowi *fl,
1113 						     u16 family, u8 dir)
1114 {
1115 	int err;
1116 	struct xfrm_policy *pol, *ret;
1117 	const xfrm_address_t *daddr, *saddr;
1118 	struct hlist_head *chain;
1119 	unsigned int sequence;
1120 	u32 priority;
1121 
1122 	daddr = xfrm_flowi_daddr(fl, family);
1123 	saddr = xfrm_flowi_saddr(fl, family);
1124 	if (unlikely(!daddr || !saddr))
1125 		return NULL;
1126 
1127 	rcu_read_lock();
1128  retry:
1129 	do {
1130 		sequence = read_seqcount_begin(&xfrm_policy_hash_generation);
1131 		chain = policy_hash_direct(net, daddr, saddr, family, dir);
1132 	} while (read_seqcount_retry(&xfrm_policy_hash_generation, sequence));
1133 
1134 	priority = ~0U;
1135 	ret = NULL;
1136 	hlist_for_each_entry_rcu(pol, chain, bydst) {
1137 		err = xfrm_policy_match(pol, fl, type, family, dir);
1138 		if (err) {
1139 			if (err == -ESRCH)
1140 				continue;
1141 			else {
1142 				ret = ERR_PTR(err);
1143 				goto fail;
1144 			}
1145 		} else {
1146 			ret = pol;
1147 			priority = ret->priority;
1148 			break;
1149 		}
1150 	}
1151 	chain = &net->xfrm.policy_inexact[dir];
1152 	hlist_for_each_entry_rcu(pol, chain, bydst) {
1153 		if ((pol->priority >= priority) && ret)
1154 			break;
1155 
1156 		err = xfrm_policy_match(pol, fl, type, family, dir);
1157 		if (err) {
1158 			if (err == -ESRCH)
1159 				continue;
1160 			else {
1161 				ret = ERR_PTR(err);
1162 				goto fail;
1163 			}
1164 		} else {
1165 			ret = pol;
1166 			break;
1167 		}
1168 	}
1169 
1170 	if (read_seqcount_retry(&xfrm_policy_hash_generation, sequence))
1171 		goto retry;
1172 
1173 	if (ret && !xfrm_pol_hold_rcu(ret))
1174 		goto retry;
1175 fail:
1176 	rcu_read_unlock();
1177 
1178 	return ret;
1179 }
1180 
1181 static struct xfrm_policy *
1182 __xfrm_policy_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir)
1183 {
1184 #ifdef CONFIG_XFRM_SUB_POLICY
1185 	struct xfrm_policy *pol;
1186 
1187 	pol = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_SUB, fl, family, dir);
1188 	if (pol != NULL)
1189 		return pol;
1190 #endif
1191 	return xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, fl, family, dir);
1192 }
1193 
1194 static int flow_to_policy_dir(int dir)
1195 {
1196 	if (XFRM_POLICY_IN == FLOW_DIR_IN &&
1197 	    XFRM_POLICY_OUT == FLOW_DIR_OUT &&
1198 	    XFRM_POLICY_FWD == FLOW_DIR_FWD)
1199 		return dir;
1200 
1201 	switch (dir) {
1202 	default:
1203 	case FLOW_DIR_IN:
1204 		return XFRM_POLICY_IN;
1205 	case FLOW_DIR_OUT:
1206 		return XFRM_POLICY_OUT;
1207 	case FLOW_DIR_FWD:
1208 		return XFRM_POLICY_FWD;
1209 	}
1210 }
1211 
1212 static struct flow_cache_object *
1213 xfrm_policy_lookup(struct net *net, const struct flowi *fl, u16 family,
1214 		   u8 dir, struct flow_cache_object *old_obj, void *ctx)
1215 {
1216 	struct xfrm_policy *pol;
1217 
1218 	if (old_obj)
1219 		xfrm_pol_put(container_of(old_obj, struct xfrm_policy, flo));
1220 
1221 	pol = __xfrm_policy_lookup(net, fl, family, flow_to_policy_dir(dir));
1222 	if (IS_ERR_OR_NULL(pol))
1223 		return ERR_CAST(pol);
1224 
1225 	/* Resolver returns two references:
1226 	 * one for cache and one for caller of flow_cache_lookup() */
1227 	xfrm_pol_hold(pol);
1228 
1229 	return &pol->flo;
1230 }
1231 
1232 static inline int policy_to_flow_dir(int dir)
1233 {
1234 	if (XFRM_POLICY_IN == FLOW_DIR_IN &&
1235 	    XFRM_POLICY_OUT == FLOW_DIR_OUT &&
1236 	    XFRM_POLICY_FWD == FLOW_DIR_FWD)
1237 		return dir;
1238 	switch (dir) {
1239 	default:
1240 	case XFRM_POLICY_IN:
1241 		return FLOW_DIR_IN;
1242 	case XFRM_POLICY_OUT:
1243 		return FLOW_DIR_OUT;
1244 	case XFRM_POLICY_FWD:
1245 		return FLOW_DIR_FWD;
1246 	}
1247 }
1248 
1249 static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir,
1250 						 const struct flowi *fl, u16 family)
1251 {
1252 	struct xfrm_policy *pol;
1253 
1254 	rcu_read_lock();
1255  again:
1256 	pol = rcu_dereference(sk->sk_policy[dir]);
1257 	if (pol != NULL) {
1258 		bool match = xfrm_selector_match(&pol->selector, fl, family);
1259 		int err = 0;
1260 
1261 		if (match) {
1262 			if ((sk->sk_mark & pol->mark.m) != pol->mark.v) {
1263 				pol = NULL;
1264 				goto out;
1265 			}
1266 			err = security_xfrm_policy_lookup(pol->security,
1267 						      fl->flowi_secid,
1268 						      policy_to_flow_dir(dir));
1269 			if (!err) {
1270 				if (!xfrm_pol_hold_rcu(pol))
1271 					goto again;
1272 			} else if (err == -ESRCH) {
1273 				pol = NULL;
1274 			} else {
1275 				pol = ERR_PTR(err);
1276 			}
1277 		} else
1278 			pol = NULL;
1279 	}
1280 out:
1281 	rcu_read_unlock();
1282 	return pol;
1283 }
1284 
1285 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
1286 {
1287 	struct net *net = xp_net(pol);
1288 
1289 	list_add(&pol->walk.all, &net->xfrm.policy_all);
1290 	net->xfrm.policy_count[dir]++;
1291 	xfrm_pol_hold(pol);
1292 }
1293 
1294 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
1295 						int dir)
1296 {
1297 	struct net *net = xp_net(pol);
1298 
1299 	if (list_empty(&pol->walk.all))
1300 		return NULL;
1301 
1302 	/* Socket policies are not hashed. */
1303 	if (!hlist_unhashed(&pol->bydst)) {
1304 		hlist_del_rcu(&pol->bydst);
1305 		hlist_del(&pol->byidx);
1306 	}
1307 
1308 	list_del_init(&pol->walk.all);
1309 	net->xfrm.policy_count[dir]--;
1310 
1311 	return pol;
1312 }
1313 
1314 static void xfrm_sk_policy_link(struct xfrm_policy *pol, int dir)
1315 {
1316 	__xfrm_policy_link(pol, XFRM_POLICY_MAX + dir);
1317 }
1318 
1319 static void xfrm_sk_policy_unlink(struct xfrm_policy *pol, int dir)
1320 {
1321 	__xfrm_policy_unlink(pol, XFRM_POLICY_MAX + dir);
1322 }
1323 
1324 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
1325 {
1326 	struct net *net = xp_net(pol);
1327 
1328 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1329 	pol = __xfrm_policy_unlink(pol, dir);
1330 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1331 	if (pol) {
1332 		xfrm_policy_kill(pol);
1333 		return 0;
1334 	}
1335 	return -ENOENT;
1336 }
1337 EXPORT_SYMBOL(xfrm_policy_delete);
1338 
1339 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
1340 {
1341 	struct net *net = xp_net(pol);
1342 	struct xfrm_policy *old_pol;
1343 
1344 #ifdef CONFIG_XFRM_SUB_POLICY
1345 	if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
1346 		return -EINVAL;
1347 #endif
1348 
1349 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1350 	old_pol = rcu_dereference_protected(sk->sk_policy[dir],
1351 				lockdep_is_held(&net->xfrm.xfrm_policy_lock));
1352 	if (pol) {
1353 		pol->curlft.add_time = get_seconds();
1354 		pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir, 0);
1355 		xfrm_sk_policy_link(pol, dir);
1356 	}
1357 	rcu_assign_pointer(sk->sk_policy[dir], pol);
1358 	if (old_pol) {
1359 		if (pol)
1360 			xfrm_policy_requeue(old_pol, pol);
1361 
1362 		/* Unlinking succeeds always. This is the only function
1363 		 * allowed to delete or replace socket policy.
1364 		 */
1365 		xfrm_sk_policy_unlink(old_pol, dir);
1366 	}
1367 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1368 
1369 	if (old_pol) {
1370 		xfrm_policy_kill(old_pol);
1371 	}
1372 	return 0;
1373 }
1374 
1375 static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
1376 {
1377 	struct xfrm_policy *newp = xfrm_policy_alloc(xp_net(old), GFP_ATOMIC);
1378 	struct net *net = xp_net(old);
1379 
1380 	if (newp) {
1381 		newp->selector = old->selector;
1382 		if (security_xfrm_policy_clone(old->security,
1383 					       &newp->security)) {
1384 			kfree(newp);
1385 			return NULL;  /* ENOMEM */
1386 		}
1387 		newp->lft = old->lft;
1388 		newp->curlft = old->curlft;
1389 		newp->mark = old->mark;
1390 		newp->action = old->action;
1391 		newp->flags = old->flags;
1392 		newp->xfrm_nr = old->xfrm_nr;
1393 		newp->index = old->index;
1394 		newp->type = old->type;
1395 		memcpy(newp->xfrm_vec, old->xfrm_vec,
1396 		       newp->xfrm_nr*sizeof(struct xfrm_tmpl));
1397 		spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1398 		xfrm_sk_policy_link(newp, dir);
1399 		spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1400 		xfrm_pol_put(newp);
1401 	}
1402 	return newp;
1403 }
1404 
1405 int __xfrm_sk_clone_policy(struct sock *sk, const struct sock *osk)
1406 {
1407 	const struct xfrm_policy *p;
1408 	struct xfrm_policy *np;
1409 	int i, ret = 0;
1410 
1411 	rcu_read_lock();
1412 	for (i = 0; i < 2; i++) {
1413 		p = rcu_dereference(osk->sk_policy[i]);
1414 		if (p) {
1415 			np = clone_policy(p, i);
1416 			if (unlikely(!np)) {
1417 				ret = -ENOMEM;
1418 				break;
1419 			}
1420 			rcu_assign_pointer(sk->sk_policy[i], np);
1421 		}
1422 	}
1423 	rcu_read_unlock();
1424 	return ret;
1425 }
1426 
1427 static int
1428 xfrm_get_saddr(struct net *net, int oif, xfrm_address_t *local,
1429 	       xfrm_address_t *remote, unsigned short family)
1430 {
1431 	int err;
1432 	const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1433 
1434 	if (unlikely(afinfo == NULL))
1435 		return -EINVAL;
1436 	err = afinfo->get_saddr(net, oif, local, remote);
1437 	rcu_read_unlock();
1438 	return err;
1439 }
1440 
1441 /* Resolve list of templates for the flow, given policy. */
1442 
1443 static int
1444 xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
1445 		      struct xfrm_state **xfrm, unsigned short family)
1446 {
1447 	struct net *net = xp_net(policy);
1448 	int nx;
1449 	int i, error;
1450 	xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
1451 	xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
1452 	xfrm_address_t tmp;
1453 
1454 	for (nx = 0, i = 0; i < policy->xfrm_nr; i++) {
1455 		struct xfrm_state *x;
1456 		xfrm_address_t *remote = daddr;
1457 		xfrm_address_t *local  = saddr;
1458 		struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
1459 
1460 		if (tmpl->mode == XFRM_MODE_TUNNEL ||
1461 		    tmpl->mode == XFRM_MODE_BEET) {
1462 			remote = &tmpl->id.daddr;
1463 			local = &tmpl->saddr;
1464 			if (xfrm_addr_any(local, tmpl->encap_family)) {
1465 				error = xfrm_get_saddr(net, fl->flowi_oif,
1466 						       &tmp, remote,
1467 						       tmpl->encap_family);
1468 				if (error)
1469 					goto fail;
1470 				local = &tmp;
1471 			}
1472 		}
1473 
1474 		x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
1475 
1476 		if (x && x->km.state == XFRM_STATE_VALID) {
1477 			xfrm[nx++] = x;
1478 			daddr = remote;
1479 			saddr = local;
1480 			continue;
1481 		}
1482 		if (x) {
1483 			error = (x->km.state == XFRM_STATE_ERROR ?
1484 				 -EINVAL : -EAGAIN);
1485 			xfrm_state_put(x);
1486 		} else if (error == -ESRCH) {
1487 			error = -EAGAIN;
1488 		}
1489 
1490 		if (!tmpl->optional)
1491 			goto fail;
1492 	}
1493 	return nx;
1494 
1495 fail:
1496 	for (nx--; nx >= 0; nx--)
1497 		xfrm_state_put(xfrm[nx]);
1498 	return error;
1499 }
1500 
1501 static int
1502 xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, const struct flowi *fl,
1503 		  struct xfrm_state **xfrm, unsigned short family)
1504 {
1505 	struct xfrm_state *tp[XFRM_MAX_DEPTH];
1506 	struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
1507 	int cnx = 0;
1508 	int error;
1509 	int ret;
1510 	int i;
1511 
1512 	for (i = 0; i < npols; i++) {
1513 		if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
1514 			error = -ENOBUFS;
1515 			goto fail;
1516 		}
1517 
1518 		ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
1519 		if (ret < 0) {
1520 			error = ret;
1521 			goto fail;
1522 		} else
1523 			cnx += ret;
1524 	}
1525 
1526 	/* found states are sorted for outbound processing */
1527 	if (npols > 1)
1528 		xfrm_state_sort(xfrm, tpp, cnx, family);
1529 
1530 	return cnx;
1531 
1532  fail:
1533 	for (cnx--; cnx >= 0; cnx--)
1534 		xfrm_state_put(tpp[cnx]);
1535 	return error;
1536 
1537 }
1538 
1539 static int xfrm_get_tos(const struct flowi *fl, int family)
1540 {
1541 	const struct xfrm_policy_afinfo *afinfo;
1542 	int tos = 0;
1543 
1544 	afinfo = xfrm_policy_get_afinfo(family);
1545 	tos = afinfo ? afinfo->get_tos(fl) : 0;
1546 
1547 	rcu_read_unlock();
1548 
1549 	return tos;
1550 }
1551 
1552 static struct flow_cache_object *xfrm_bundle_flo_get(struct flow_cache_object *flo)
1553 {
1554 	struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1555 	struct dst_entry *dst = &xdst->u.dst;
1556 
1557 	if (xdst->route == NULL) {
1558 		/* Dummy bundle - if it has xfrms we were not
1559 		 * able to build bundle as template resolution failed.
1560 		 * It means we need to try again resolving. */
1561 		if (xdst->num_xfrms > 0)
1562 			return NULL;
1563 	} else if (dst->flags & DST_XFRM_QUEUE) {
1564 		return NULL;
1565 	} else {
1566 		/* Real bundle */
1567 		if (stale_bundle(dst))
1568 			return NULL;
1569 	}
1570 
1571 	dst_hold(dst);
1572 	return flo;
1573 }
1574 
1575 static int xfrm_bundle_flo_check(struct flow_cache_object *flo)
1576 {
1577 	struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1578 	struct dst_entry *dst = &xdst->u.dst;
1579 
1580 	if (!xdst->route)
1581 		return 0;
1582 	if (stale_bundle(dst))
1583 		return 0;
1584 
1585 	return 1;
1586 }
1587 
1588 static void xfrm_bundle_flo_delete(struct flow_cache_object *flo)
1589 {
1590 	struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1591 	struct dst_entry *dst = &xdst->u.dst;
1592 
1593 	dst_free(dst);
1594 }
1595 
1596 static const struct flow_cache_ops xfrm_bundle_fc_ops = {
1597 	.get = xfrm_bundle_flo_get,
1598 	.check = xfrm_bundle_flo_check,
1599 	.delete = xfrm_bundle_flo_delete,
1600 };
1601 
1602 static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
1603 {
1604 	const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1605 	struct dst_ops *dst_ops;
1606 	struct xfrm_dst *xdst;
1607 
1608 	if (!afinfo)
1609 		return ERR_PTR(-EINVAL);
1610 
1611 	switch (family) {
1612 	case AF_INET:
1613 		dst_ops = &net->xfrm.xfrm4_dst_ops;
1614 		break;
1615 #if IS_ENABLED(CONFIG_IPV6)
1616 	case AF_INET6:
1617 		dst_ops = &net->xfrm.xfrm6_dst_ops;
1618 		break;
1619 #endif
1620 	default:
1621 		BUG();
1622 	}
1623 	xdst = dst_alloc(dst_ops, NULL, 0, DST_OBSOLETE_NONE, 0);
1624 
1625 	if (likely(xdst)) {
1626 		struct dst_entry *dst = &xdst->u.dst;
1627 
1628 		memset(dst + 1, 0, sizeof(*xdst) - sizeof(*dst));
1629 		xdst->flo.ops = &xfrm_bundle_fc_ops;
1630 	} else
1631 		xdst = ERR_PTR(-ENOBUFS);
1632 
1633 	rcu_read_unlock();
1634 
1635 	return xdst;
1636 }
1637 
1638 static inline int xfrm_init_path(struct xfrm_dst *path, struct dst_entry *dst,
1639 				 int nfheader_len)
1640 {
1641 	const struct xfrm_policy_afinfo *afinfo =
1642 		xfrm_policy_get_afinfo(dst->ops->family);
1643 	int err;
1644 
1645 	if (!afinfo)
1646 		return -EINVAL;
1647 
1648 	err = afinfo->init_path(path, dst, nfheader_len);
1649 
1650 	rcu_read_unlock();
1651 
1652 	return err;
1653 }
1654 
1655 static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
1656 				const struct flowi *fl)
1657 {
1658 	const struct xfrm_policy_afinfo *afinfo =
1659 		xfrm_policy_get_afinfo(xdst->u.dst.ops->family);
1660 	int err;
1661 
1662 	if (!afinfo)
1663 		return -EINVAL;
1664 
1665 	err = afinfo->fill_dst(xdst, dev, fl);
1666 
1667 	rcu_read_unlock();
1668 
1669 	return err;
1670 }
1671 
1672 
1673 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
1674  * all the metrics... Shortly, bundle a bundle.
1675  */
1676 
1677 static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
1678 					    struct xfrm_state **xfrm, int nx,
1679 					    const struct flowi *fl,
1680 					    struct dst_entry *dst)
1681 {
1682 	struct net *net = xp_net(policy);
1683 	unsigned long now = jiffies;
1684 	struct net_device *dev;
1685 	struct xfrm_mode *inner_mode;
1686 	struct dst_entry *dst_prev = NULL;
1687 	struct dst_entry *dst0 = NULL;
1688 	int i = 0;
1689 	int err;
1690 	int header_len = 0;
1691 	int nfheader_len = 0;
1692 	int trailer_len = 0;
1693 	int tos;
1694 	int family = policy->selector.family;
1695 	xfrm_address_t saddr, daddr;
1696 
1697 	xfrm_flowi_addr_get(fl, &saddr, &daddr, family);
1698 
1699 	tos = xfrm_get_tos(fl, family);
1700 
1701 	dst_hold(dst);
1702 
1703 	for (; i < nx; i++) {
1704 		struct xfrm_dst *xdst = xfrm_alloc_dst(net, family);
1705 		struct dst_entry *dst1 = &xdst->u.dst;
1706 
1707 		err = PTR_ERR(xdst);
1708 		if (IS_ERR(xdst)) {
1709 			dst_release(dst);
1710 			goto put_states;
1711 		}
1712 
1713 		if (xfrm[i]->sel.family == AF_UNSPEC) {
1714 			inner_mode = xfrm_ip2inner_mode(xfrm[i],
1715 							xfrm_af2proto(family));
1716 			if (!inner_mode) {
1717 				err = -EAFNOSUPPORT;
1718 				dst_release(dst);
1719 				goto put_states;
1720 			}
1721 		} else
1722 			inner_mode = xfrm[i]->inner_mode;
1723 
1724 		if (!dst_prev)
1725 			dst0 = dst1;
1726 		else {
1727 			dst_prev->child = dst_clone(dst1);
1728 			dst1->flags |= DST_NOHASH;
1729 		}
1730 
1731 		xdst->route = dst;
1732 		dst_copy_metrics(dst1, dst);
1733 
1734 		if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
1735 			family = xfrm[i]->props.family;
1736 			dst = xfrm_dst_lookup(xfrm[i], tos, fl->flowi_oif,
1737 					      &saddr, &daddr, family);
1738 			err = PTR_ERR(dst);
1739 			if (IS_ERR(dst))
1740 				goto put_states;
1741 		} else
1742 			dst_hold(dst);
1743 
1744 		dst1->xfrm = xfrm[i];
1745 		xdst->xfrm_genid = xfrm[i]->genid;
1746 
1747 		dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
1748 		dst1->flags |= DST_HOST;
1749 		dst1->lastuse = now;
1750 
1751 		dst1->input = dst_discard;
1752 		dst1->output = inner_mode->afinfo->output;
1753 
1754 		dst1->next = dst_prev;
1755 		dst_prev = dst1;
1756 
1757 		header_len += xfrm[i]->props.header_len;
1758 		if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
1759 			nfheader_len += xfrm[i]->props.header_len;
1760 		trailer_len += xfrm[i]->props.trailer_len;
1761 	}
1762 
1763 	dst_prev->child = dst;
1764 	dst0->path = dst;
1765 
1766 	err = -ENODEV;
1767 	dev = dst->dev;
1768 	if (!dev)
1769 		goto free_dst;
1770 
1771 	xfrm_init_path((struct xfrm_dst *)dst0, dst, nfheader_len);
1772 	xfrm_init_pmtu(dst_prev);
1773 
1774 	for (dst_prev = dst0; dst_prev != dst; dst_prev = dst_prev->child) {
1775 		struct xfrm_dst *xdst = (struct xfrm_dst *)dst_prev;
1776 
1777 		err = xfrm_fill_dst(xdst, dev, fl);
1778 		if (err)
1779 			goto free_dst;
1780 
1781 		dst_prev->header_len = header_len;
1782 		dst_prev->trailer_len = trailer_len;
1783 		header_len -= xdst->u.dst.xfrm->props.header_len;
1784 		trailer_len -= xdst->u.dst.xfrm->props.trailer_len;
1785 	}
1786 
1787 out:
1788 	return dst0;
1789 
1790 put_states:
1791 	for (; i < nx; i++)
1792 		xfrm_state_put(xfrm[i]);
1793 free_dst:
1794 	if (dst0)
1795 		dst_free(dst0);
1796 	dst0 = ERR_PTR(err);
1797 	goto out;
1798 }
1799 
1800 static int xfrm_expand_policies(const struct flowi *fl, u16 family,
1801 				struct xfrm_policy **pols,
1802 				int *num_pols, int *num_xfrms)
1803 {
1804 	int i;
1805 
1806 	if (*num_pols == 0 || !pols[0]) {
1807 		*num_pols = 0;
1808 		*num_xfrms = 0;
1809 		return 0;
1810 	}
1811 	if (IS_ERR(pols[0]))
1812 		return PTR_ERR(pols[0]);
1813 
1814 	*num_xfrms = pols[0]->xfrm_nr;
1815 
1816 #ifdef CONFIG_XFRM_SUB_POLICY
1817 	if (pols[0] && pols[0]->action == XFRM_POLICY_ALLOW &&
1818 	    pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1819 		pols[1] = xfrm_policy_lookup_bytype(xp_net(pols[0]),
1820 						    XFRM_POLICY_TYPE_MAIN,
1821 						    fl, family,
1822 						    XFRM_POLICY_OUT);
1823 		if (pols[1]) {
1824 			if (IS_ERR(pols[1])) {
1825 				xfrm_pols_put(pols, *num_pols);
1826 				return PTR_ERR(pols[1]);
1827 			}
1828 			(*num_pols)++;
1829 			(*num_xfrms) += pols[1]->xfrm_nr;
1830 		}
1831 	}
1832 #endif
1833 	for (i = 0; i < *num_pols; i++) {
1834 		if (pols[i]->action != XFRM_POLICY_ALLOW) {
1835 			*num_xfrms = -1;
1836 			break;
1837 		}
1838 	}
1839 
1840 	return 0;
1841 
1842 }
1843 
1844 static struct xfrm_dst *
1845 xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
1846 			       const struct flowi *fl, u16 family,
1847 			       struct dst_entry *dst_orig)
1848 {
1849 	struct net *net = xp_net(pols[0]);
1850 	struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
1851 	struct dst_entry *dst;
1852 	struct xfrm_dst *xdst;
1853 	int err;
1854 
1855 	/* Try to instantiate a bundle */
1856 	err = xfrm_tmpl_resolve(pols, num_pols, fl, xfrm, family);
1857 	if (err <= 0) {
1858 		if (err != 0 && err != -EAGAIN)
1859 			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
1860 		return ERR_PTR(err);
1861 	}
1862 
1863 	dst = xfrm_bundle_create(pols[0], xfrm, err, fl, dst_orig);
1864 	if (IS_ERR(dst)) {
1865 		XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR);
1866 		return ERR_CAST(dst);
1867 	}
1868 
1869 	xdst = (struct xfrm_dst *)dst;
1870 	xdst->num_xfrms = err;
1871 	xdst->num_pols = num_pols;
1872 	memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
1873 	xdst->policy_genid = atomic_read(&pols[0]->genid);
1874 
1875 	return xdst;
1876 }
1877 
1878 static void xfrm_policy_queue_process(unsigned long arg)
1879 {
1880 	struct sk_buff *skb;
1881 	struct sock *sk;
1882 	struct dst_entry *dst;
1883 	struct xfrm_policy *pol = (struct xfrm_policy *)arg;
1884 	struct net *net = xp_net(pol);
1885 	struct xfrm_policy_queue *pq = &pol->polq;
1886 	struct flowi fl;
1887 	struct sk_buff_head list;
1888 
1889 	spin_lock(&pq->hold_queue.lock);
1890 	skb = skb_peek(&pq->hold_queue);
1891 	if (!skb) {
1892 		spin_unlock(&pq->hold_queue.lock);
1893 		goto out;
1894 	}
1895 	dst = skb_dst(skb);
1896 	sk = skb->sk;
1897 	xfrm_decode_session(skb, &fl, dst->ops->family);
1898 	spin_unlock(&pq->hold_queue.lock);
1899 
1900 	dst_hold(dst->path);
1901 	dst = xfrm_lookup(net, dst->path, &fl, sk, 0);
1902 	if (IS_ERR(dst))
1903 		goto purge_queue;
1904 
1905 	if (dst->flags & DST_XFRM_QUEUE) {
1906 		dst_release(dst);
1907 
1908 		if (pq->timeout >= XFRM_QUEUE_TMO_MAX)
1909 			goto purge_queue;
1910 
1911 		pq->timeout = pq->timeout << 1;
1912 		if (!mod_timer(&pq->hold_timer, jiffies + pq->timeout))
1913 			xfrm_pol_hold(pol);
1914 	goto out;
1915 	}
1916 
1917 	dst_release(dst);
1918 
1919 	__skb_queue_head_init(&list);
1920 
1921 	spin_lock(&pq->hold_queue.lock);
1922 	pq->timeout = 0;
1923 	skb_queue_splice_init(&pq->hold_queue, &list);
1924 	spin_unlock(&pq->hold_queue.lock);
1925 
1926 	while (!skb_queue_empty(&list)) {
1927 		skb = __skb_dequeue(&list);
1928 
1929 		xfrm_decode_session(skb, &fl, skb_dst(skb)->ops->family);
1930 		dst_hold(skb_dst(skb)->path);
1931 		dst = xfrm_lookup(net, skb_dst(skb)->path, &fl, skb->sk, 0);
1932 		if (IS_ERR(dst)) {
1933 			kfree_skb(skb);
1934 			continue;
1935 		}
1936 
1937 		nf_reset(skb);
1938 		skb_dst_drop(skb);
1939 		skb_dst_set(skb, dst);
1940 
1941 		dst_output(net, skb->sk, skb);
1942 	}
1943 
1944 out:
1945 	xfrm_pol_put(pol);
1946 	return;
1947 
1948 purge_queue:
1949 	pq->timeout = 0;
1950 	skb_queue_purge(&pq->hold_queue);
1951 	xfrm_pol_put(pol);
1952 }
1953 
1954 static int xdst_queue_output(struct net *net, struct sock *sk, struct sk_buff *skb)
1955 {
1956 	unsigned long sched_next;
1957 	struct dst_entry *dst = skb_dst(skb);
1958 	struct xfrm_dst *xdst = (struct xfrm_dst *) dst;
1959 	struct xfrm_policy *pol = xdst->pols[0];
1960 	struct xfrm_policy_queue *pq = &pol->polq;
1961 
1962 	if (unlikely(skb_fclone_busy(sk, skb))) {
1963 		kfree_skb(skb);
1964 		return 0;
1965 	}
1966 
1967 	if (pq->hold_queue.qlen > XFRM_MAX_QUEUE_LEN) {
1968 		kfree_skb(skb);
1969 		return -EAGAIN;
1970 	}
1971 
1972 	skb_dst_force(skb);
1973 
1974 	spin_lock_bh(&pq->hold_queue.lock);
1975 
1976 	if (!pq->timeout)
1977 		pq->timeout = XFRM_QUEUE_TMO_MIN;
1978 
1979 	sched_next = jiffies + pq->timeout;
1980 
1981 	if (del_timer(&pq->hold_timer)) {
1982 		if (time_before(pq->hold_timer.expires, sched_next))
1983 			sched_next = pq->hold_timer.expires;
1984 		xfrm_pol_put(pol);
1985 	}
1986 
1987 	__skb_queue_tail(&pq->hold_queue, skb);
1988 	if (!mod_timer(&pq->hold_timer, sched_next))
1989 		xfrm_pol_hold(pol);
1990 
1991 	spin_unlock_bh(&pq->hold_queue.lock);
1992 
1993 	return 0;
1994 }
1995 
1996 static struct xfrm_dst *xfrm_create_dummy_bundle(struct net *net,
1997 						 struct xfrm_flo *xflo,
1998 						 const struct flowi *fl,
1999 						 int num_xfrms,
2000 						 u16 family)
2001 {
2002 	int err;
2003 	struct net_device *dev;
2004 	struct dst_entry *dst;
2005 	struct dst_entry *dst1;
2006 	struct xfrm_dst *xdst;
2007 
2008 	xdst = xfrm_alloc_dst(net, family);
2009 	if (IS_ERR(xdst))
2010 		return xdst;
2011 
2012 	if (!(xflo->flags & XFRM_LOOKUP_QUEUE) ||
2013 	    net->xfrm.sysctl_larval_drop ||
2014 	    num_xfrms <= 0)
2015 		return xdst;
2016 
2017 	dst = xflo->dst_orig;
2018 	dst1 = &xdst->u.dst;
2019 	dst_hold(dst);
2020 	xdst->route = dst;
2021 
2022 	dst_copy_metrics(dst1, dst);
2023 
2024 	dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
2025 	dst1->flags |= DST_HOST | DST_XFRM_QUEUE;
2026 	dst1->lastuse = jiffies;
2027 
2028 	dst1->input = dst_discard;
2029 	dst1->output = xdst_queue_output;
2030 
2031 	dst_hold(dst);
2032 	dst1->child = dst;
2033 	dst1->path = dst;
2034 
2035 	xfrm_init_path((struct xfrm_dst *)dst1, dst, 0);
2036 
2037 	err = -ENODEV;
2038 	dev = dst->dev;
2039 	if (!dev)
2040 		goto free_dst;
2041 
2042 	err = xfrm_fill_dst(xdst, dev, fl);
2043 	if (err)
2044 		goto free_dst;
2045 
2046 out:
2047 	return xdst;
2048 
2049 free_dst:
2050 	dst_release(dst1);
2051 	xdst = ERR_PTR(err);
2052 	goto out;
2053 }
2054 
2055 static struct flow_cache_object *
2056 xfrm_bundle_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir,
2057 		   struct flow_cache_object *oldflo, void *ctx)
2058 {
2059 	struct xfrm_flo *xflo = (struct xfrm_flo *)ctx;
2060 	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2061 	struct xfrm_dst *xdst, *new_xdst;
2062 	int num_pols = 0, num_xfrms = 0, i, err, pol_dead;
2063 
2064 	/* Check if the policies from old bundle are usable */
2065 	xdst = NULL;
2066 	if (oldflo) {
2067 		xdst = container_of(oldflo, struct xfrm_dst, flo);
2068 		num_pols = xdst->num_pols;
2069 		num_xfrms = xdst->num_xfrms;
2070 		pol_dead = 0;
2071 		for (i = 0; i < num_pols; i++) {
2072 			pols[i] = xdst->pols[i];
2073 			pol_dead |= pols[i]->walk.dead;
2074 		}
2075 		if (pol_dead) {
2076 			dst_free(&xdst->u.dst);
2077 			xdst = NULL;
2078 			num_pols = 0;
2079 			num_xfrms = 0;
2080 			oldflo = NULL;
2081 		}
2082 	}
2083 
2084 	/* Resolve policies to use if we couldn't get them from
2085 	 * previous cache entry */
2086 	if (xdst == NULL) {
2087 		num_pols = 1;
2088 		pols[0] = __xfrm_policy_lookup(net, fl, family,
2089 					       flow_to_policy_dir(dir));
2090 		err = xfrm_expand_policies(fl, family, pols,
2091 					   &num_pols, &num_xfrms);
2092 		if (err < 0)
2093 			goto inc_error;
2094 		if (num_pols == 0)
2095 			return NULL;
2096 		if (num_xfrms <= 0)
2097 			goto make_dummy_bundle;
2098 	}
2099 
2100 	new_xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family,
2101 						  xflo->dst_orig);
2102 	if (IS_ERR(new_xdst)) {
2103 		err = PTR_ERR(new_xdst);
2104 		if (err != -EAGAIN)
2105 			goto error;
2106 		if (oldflo == NULL)
2107 			goto make_dummy_bundle;
2108 		dst_hold(&xdst->u.dst);
2109 		return oldflo;
2110 	} else if (new_xdst == NULL) {
2111 		num_xfrms = 0;
2112 		if (oldflo == NULL)
2113 			goto make_dummy_bundle;
2114 		xdst->num_xfrms = 0;
2115 		dst_hold(&xdst->u.dst);
2116 		return oldflo;
2117 	}
2118 
2119 	/* Kill the previous bundle */
2120 	if (xdst) {
2121 		/* The policies were stolen for newly generated bundle */
2122 		xdst->num_pols = 0;
2123 		dst_free(&xdst->u.dst);
2124 	}
2125 
2126 	/* Flow cache does not have reference, it dst_free()'s,
2127 	 * but we do need to return one reference for original caller */
2128 	dst_hold(&new_xdst->u.dst);
2129 	return &new_xdst->flo;
2130 
2131 make_dummy_bundle:
2132 	/* We found policies, but there's no bundles to instantiate:
2133 	 * either because the policy blocks, has no transformations or
2134 	 * we could not build template (no xfrm_states).*/
2135 	xdst = xfrm_create_dummy_bundle(net, xflo, fl, num_xfrms, family);
2136 	if (IS_ERR(xdst)) {
2137 		xfrm_pols_put(pols, num_pols);
2138 		return ERR_CAST(xdst);
2139 	}
2140 	xdst->num_pols = num_pols;
2141 	xdst->num_xfrms = num_xfrms;
2142 	memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
2143 
2144 	dst_hold(&xdst->u.dst);
2145 	return &xdst->flo;
2146 
2147 inc_error:
2148 	XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
2149 error:
2150 	if (xdst != NULL)
2151 		dst_free(&xdst->u.dst);
2152 	else
2153 		xfrm_pols_put(pols, num_pols);
2154 	return ERR_PTR(err);
2155 }
2156 
2157 static struct dst_entry *make_blackhole(struct net *net, u16 family,
2158 					struct dst_entry *dst_orig)
2159 {
2160 	const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2161 	struct dst_entry *ret;
2162 
2163 	if (!afinfo) {
2164 		dst_release(dst_orig);
2165 		return ERR_PTR(-EINVAL);
2166 	} else {
2167 		ret = afinfo->blackhole_route(net, dst_orig);
2168 	}
2169 	rcu_read_unlock();
2170 
2171 	return ret;
2172 }
2173 
2174 /* Main function: finds/creates a bundle for given flow.
2175  *
2176  * At the moment we eat a raw IP route. Mostly to speed up lookups
2177  * on interfaces with disabled IPsec.
2178  */
2179 struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
2180 			      const struct flowi *fl,
2181 			      const struct sock *sk, int flags)
2182 {
2183 	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2184 	struct flow_cache_object *flo;
2185 	struct xfrm_dst *xdst;
2186 	struct dst_entry *dst, *route;
2187 	u16 family = dst_orig->ops->family;
2188 	u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
2189 	int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
2190 
2191 	dst = NULL;
2192 	xdst = NULL;
2193 	route = NULL;
2194 
2195 	sk = sk_const_to_full_sk(sk);
2196 	if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
2197 		num_pols = 1;
2198 		pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, family);
2199 		err = xfrm_expand_policies(fl, family, pols,
2200 					   &num_pols, &num_xfrms);
2201 		if (err < 0)
2202 			goto dropdst;
2203 
2204 		if (num_pols) {
2205 			if (num_xfrms <= 0) {
2206 				drop_pols = num_pols;
2207 				goto no_transform;
2208 			}
2209 
2210 			xdst = xfrm_resolve_and_create_bundle(
2211 					pols, num_pols, fl,
2212 					family, dst_orig);
2213 			if (IS_ERR(xdst)) {
2214 				xfrm_pols_put(pols, num_pols);
2215 				err = PTR_ERR(xdst);
2216 				goto dropdst;
2217 			} else if (xdst == NULL) {
2218 				num_xfrms = 0;
2219 				drop_pols = num_pols;
2220 				goto no_transform;
2221 			}
2222 
2223 			dst_hold(&xdst->u.dst);
2224 			xdst->u.dst.flags |= DST_NOCACHE;
2225 			route = xdst->route;
2226 		}
2227 	}
2228 
2229 	if (xdst == NULL) {
2230 		struct xfrm_flo xflo;
2231 
2232 		xflo.dst_orig = dst_orig;
2233 		xflo.flags = flags;
2234 
2235 		/* To accelerate a bit...  */
2236 		if ((dst_orig->flags & DST_NOXFRM) ||
2237 		    !net->xfrm.policy_count[XFRM_POLICY_OUT])
2238 			goto nopol;
2239 
2240 		flo = flow_cache_lookup(net, fl, family, dir,
2241 					xfrm_bundle_lookup, &xflo);
2242 		if (flo == NULL)
2243 			goto nopol;
2244 		if (IS_ERR(flo)) {
2245 			err = PTR_ERR(flo);
2246 			goto dropdst;
2247 		}
2248 		xdst = container_of(flo, struct xfrm_dst, flo);
2249 
2250 		num_pols = xdst->num_pols;
2251 		num_xfrms = xdst->num_xfrms;
2252 		memcpy(pols, xdst->pols, sizeof(struct xfrm_policy *) * num_pols);
2253 		route = xdst->route;
2254 	}
2255 
2256 	dst = &xdst->u.dst;
2257 	if (route == NULL && num_xfrms > 0) {
2258 		/* The only case when xfrm_bundle_lookup() returns a
2259 		 * bundle with null route, is when the template could
2260 		 * not be resolved. It means policies are there, but
2261 		 * bundle could not be created, since we don't yet
2262 		 * have the xfrm_state's. We need to wait for KM to
2263 		 * negotiate new SA's or bail out with error.*/
2264 		if (net->xfrm.sysctl_larval_drop) {
2265 			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
2266 			err = -EREMOTE;
2267 			goto error;
2268 		}
2269 
2270 		err = -EAGAIN;
2271 
2272 		XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
2273 		goto error;
2274 	}
2275 
2276 no_transform:
2277 	if (num_pols == 0)
2278 		goto nopol;
2279 
2280 	if ((flags & XFRM_LOOKUP_ICMP) &&
2281 	    !(pols[0]->flags & XFRM_POLICY_ICMP)) {
2282 		err = -ENOENT;
2283 		goto error;
2284 	}
2285 
2286 	for (i = 0; i < num_pols; i++)
2287 		pols[i]->curlft.use_time = get_seconds();
2288 
2289 	if (num_xfrms < 0) {
2290 		/* Prohibit the flow */
2291 		XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLBLOCK);
2292 		err = -EPERM;
2293 		goto error;
2294 	} else if (num_xfrms > 0) {
2295 		/* Flow transformed */
2296 		dst_release(dst_orig);
2297 	} else {
2298 		/* Flow passes untransformed */
2299 		dst_release(dst);
2300 		dst = dst_orig;
2301 	}
2302 ok:
2303 	xfrm_pols_put(pols, drop_pols);
2304 	if (dst && dst->xfrm &&
2305 	    dst->xfrm->props.mode == XFRM_MODE_TUNNEL)
2306 		dst->flags |= DST_XFRM_TUNNEL;
2307 	return dst;
2308 
2309 nopol:
2310 	if (!(flags & XFRM_LOOKUP_ICMP)) {
2311 		dst = dst_orig;
2312 		goto ok;
2313 	}
2314 	err = -ENOENT;
2315 error:
2316 	dst_release(dst);
2317 dropdst:
2318 	if (!(flags & XFRM_LOOKUP_KEEP_DST_REF))
2319 		dst_release(dst_orig);
2320 	xfrm_pols_put(pols, drop_pols);
2321 	return ERR_PTR(err);
2322 }
2323 EXPORT_SYMBOL(xfrm_lookup);
2324 
2325 /* Callers of xfrm_lookup_route() must ensure a call to dst_output().
2326  * Otherwise we may send out blackholed packets.
2327  */
2328 struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
2329 				    const struct flowi *fl,
2330 				    const struct sock *sk, int flags)
2331 {
2332 	struct dst_entry *dst = xfrm_lookup(net, dst_orig, fl, sk,
2333 					    flags | XFRM_LOOKUP_QUEUE |
2334 					    XFRM_LOOKUP_KEEP_DST_REF);
2335 
2336 	if (IS_ERR(dst) && PTR_ERR(dst) == -EREMOTE)
2337 		return make_blackhole(net, dst_orig->ops->family, dst_orig);
2338 
2339 	return dst;
2340 }
2341 EXPORT_SYMBOL(xfrm_lookup_route);
2342 
2343 static inline int
2344 xfrm_secpath_reject(int idx, struct sk_buff *skb, const struct flowi *fl)
2345 {
2346 	struct xfrm_state *x;
2347 
2348 	if (!skb->sp || idx < 0 || idx >= skb->sp->len)
2349 		return 0;
2350 	x = skb->sp->xvec[idx];
2351 	if (!x->type->reject)
2352 		return 0;
2353 	return x->type->reject(x, skb, fl);
2354 }
2355 
2356 /* When skb is transformed back to its "native" form, we have to
2357  * check policy restrictions. At the moment we make this in maximally
2358  * stupid way. Shame on me. :-) Of course, connected sockets must
2359  * have policy cached at them.
2360  */
2361 
2362 static inline int
2363 xfrm_state_ok(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x,
2364 	      unsigned short family)
2365 {
2366 	if (xfrm_state_kern(x))
2367 		return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
2368 	return	x->id.proto == tmpl->id.proto &&
2369 		(x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
2370 		(x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
2371 		x->props.mode == tmpl->mode &&
2372 		(tmpl->allalgs || (tmpl->aalgos & (1<<x->props.aalgo)) ||
2373 		 !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
2374 		!(x->props.mode != XFRM_MODE_TRANSPORT &&
2375 		  xfrm_state_addr_cmp(tmpl, x, family));
2376 }
2377 
2378 /*
2379  * 0 or more than 0 is returned when validation is succeeded (either bypass
2380  * because of optional transport mode, or next index of the mathced secpath
2381  * state with the template.
2382  * -1 is returned when no matching template is found.
2383  * Otherwise "-2 - errored_index" is returned.
2384  */
2385 static inline int
2386 xfrm_policy_ok(const struct xfrm_tmpl *tmpl, const struct sec_path *sp, int start,
2387 	       unsigned short family)
2388 {
2389 	int idx = start;
2390 
2391 	if (tmpl->optional) {
2392 		if (tmpl->mode == XFRM_MODE_TRANSPORT)
2393 			return start;
2394 	} else
2395 		start = -1;
2396 	for (; idx < sp->len; idx++) {
2397 		if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
2398 			return ++idx;
2399 		if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
2400 			if (start == -1)
2401 				start = -2-idx;
2402 			break;
2403 		}
2404 	}
2405 	return start;
2406 }
2407 
2408 int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
2409 			  unsigned int family, int reverse)
2410 {
2411 	const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2412 	int err;
2413 
2414 	if (unlikely(afinfo == NULL))
2415 		return -EAFNOSUPPORT;
2416 
2417 	afinfo->decode_session(skb, fl, reverse);
2418 	err = security_xfrm_decode_session(skb, &fl->flowi_secid);
2419 	rcu_read_unlock();
2420 	return err;
2421 }
2422 EXPORT_SYMBOL(__xfrm_decode_session);
2423 
2424 static inline int secpath_has_nontransport(const struct sec_path *sp, int k, int *idxp)
2425 {
2426 	for (; k < sp->len; k++) {
2427 		if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
2428 			*idxp = k;
2429 			return 1;
2430 		}
2431 	}
2432 
2433 	return 0;
2434 }
2435 
2436 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
2437 			unsigned short family)
2438 {
2439 	struct net *net = dev_net(skb->dev);
2440 	struct xfrm_policy *pol;
2441 	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2442 	int npols = 0;
2443 	int xfrm_nr;
2444 	int pi;
2445 	int reverse;
2446 	struct flowi fl;
2447 	u8 fl_dir;
2448 	int xerr_idx = -1;
2449 
2450 	reverse = dir & ~XFRM_POLICY_MASK;
2451 	dir &= XFRM_POLICY_MASK;
2452 	fl_dir = policy_to_flow_dir(dir);
2453 
2454 	if (__xfrm_decode_session(skb, &fl, family, reverse) < 0) {
2455 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
2456 		return 0;
2457 	}
2458 
2459 	nf_nat_decode_session(skb, &fl, family);
2460 
2461 	/* First, check used SA against their selectors. */
2462 	if (skb->sp) {
2463 		int i;
2464 
2465 		for (i = skb->sp->len-1; i >= 0; i--) {
2466 			struct xfrm_state *x = skb->sp->xvec[i];
2467 			if (!xfrm_selector_match(&x->sel, &fl, family)) {
2468 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
2469 				return 0;
2470 			}
2471 		}
2472 	}
2473 
2474 	pol = NULL;
2475 	sk = sk_to_full_sk(sk);
2476 	if (sk && sk->sk_policy[dir]) {
2477 		pol = xfrm_sk_policy_lookup(sk, dir, &fl, family);
2478 		if (IS_ERR(pol)) {
2479 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2480 			return 0;
2481 		}
2482 	}
2483 
2484 	if (!pol) {
2485 		struct flow_cache_object *flo;
2486 
2487 		flo = flow_cache_lookup(net, &fl, family, fl_dir,
2488 					xfrm_policy_lookup, NULL);
2489 		if (IS_ERR_OR_NULL(flo))
2490 			pol = ERR_CAST(flo);
2491 		else
2492 			pol = container_of(flo, struct xfrm_policy, flo);
2493 	}
2494 
2495 	if (IS_ERR(pol)) {
2496 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2497 		return 0;
2498 	}
2499 
2500 	if (!pol) {
2501 		if (skb->sp && secpath_has_nontransport(skb->sp, 0, &xerr_idx)) {
2502 			xfrm_secpath_reject(xerr_idx, skb, &fl);
2503 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
2504 			return 0;
2505 		}
2506 		return 1;
2507 	}
2508 
2509 	pol->curlft.use_time = get_seconds();
2510 
2511 	pols[0] = pol;
2512 	npols++;
2513 #ifdef CONFIG_XFRM_SUB_POLICY
2514 	if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
2515 		pols[1] = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN,
2516 						    &fl, family,
2517 						    XFRM_POLICY_IN);
2518 		if (pols[1]) {
2519 			if (IS_ERR(pols[1])) {
2520 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2521 				return 0;
2522 			}
2523 			pols[1]->curlft.use_time = get_seconds();
2524 			npols++;
2525 		}
2526 	}
2527 #endif
2528 
2529 	if (pol->action == XFRM_POLICY_ALLOW) {
2530 		struct sec_path *sp;
2531 		static struct sec_path dummy;
2532 		struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
2533 		struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
2534 		struct xfrm_tmpl **tpp = tp;
2535 		int ti = 0;
2536 		int i, k;
2537 
2538 		if ((sp = skb->sp) == NULL)
2539 			sp = &dummy;
2540 
2541 		for (pi = 0; pi < npols; pi++) {
2542 			if (pols[pi] != pol &&
2543 			    pols[pi]->action != XFRM_POLICY_ALLOW) {
2544 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2545 				goto reject;
2546 			}
2547 			if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH) {
2548 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
2549 				goto reject_error;
2550 			}
2551 			for (i = 0; i < pols[pi]->xfrm_nr; i++)
2552 				tpp[ti++] = &pols[pi]->xfrm_vec[i];
2553 		}
2554 		xfrm_nr = ti;
2555 		if (npols > 1) {
2556 			xfrm_tmpl_sort(stp, tpp, xfrm_nr, family, net);
2557 			tpp = stp;
2558 		}
2559 
2560 		/* For each tunnel xfrm, find the first matching tmpl.
2561 		 * For each tmpl before that, find corresponding xfrm.
2562 		 * Order is _important_. Later we will implement
2563 		 * some barriers, but at the moment barriers
2564 		 * are implied between each two transformations.
2565 		 */
2566 		for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
2567 			k = xfrm_policy_ok(tpp[i], sp, k, family);
2568 			if (k < 0) {
2569 				if (k < -1)
2570 					/* "-2 - errored_index" returned */
2571 					xerr_idx = -(2+k);
2572 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2573 				goto reject;
2574 			}
2575 		}
2576 
2577 		if (secpath_has_nontransport(sp, k, &xerr_idx)) {
2578 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2579 			goto reject;
2580 		}
2581 
2582 		xfrm_pols_put(pols, npols);
2583 		return 1;
2584 	}
2585 	XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2586 
2587 reject:
2588 	xfrm_secpath_reject(xerr_idx, skb, &fl);
2589 reject_error:
2590 	xfrm_pols_put(pols, npols);
2591 	return 0;
2592 }
2593 EXPORT_SYMBOL(__xfrm_policy_check);
2594 
2595 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
2596 {
2597 	struct net *net = dev_net(skb->dev);
2598 	struct flowi fl;
2599 	struct dst_entry *dst;
2600 	int res = 1;
2601 
2602 	if (xfrm_decode_session(skb, &fl, family) < 0) {
2603 		XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
2604 		return 0;
2605 	}
2606 
2607 	skb_dst_force(skb);
2608 
2609 	dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, XFRM_LOOKUP_QUEUE);
2610 	if (IS_ERR(dst)) {
2611 		res = 0;
2612 		dst = NULL;
2613 	}
2614 	skb_dst_set(skb, dst);
2615 	return res;
2616 }
2617 EXPORT_SYMBOL(__xfrm_route_forward);
2618 
2619 /* Optimize later using cookies and generation ids. */
2620 
2621 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
2622 {
2623 	/* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
2624 	 * to DST_OBSOLETE_FORCE_CHK to force all XFRM destinations to
2625 	 * get validated by dst_ops->check on every use.  We do this
2626 	 * because when a normal route referenced by an XFRM dst is
2627 	 * obsoleted we do not go looking around for all parent
2628 	 * referencing XFRM dsts so that we can invalidate them.  It
2629 	 * is just too much work.  Instead we make the checks here on
2630 	 * every use.  For example:
2631 	 *
2632 	 *	XFRM dst A --> IPv4 dst X
2633 	 *
2634 	 * X is the "xdst->route" of A (X is also the "dst->path" of A
2635 	 * in this example).  If X is marked obsolete, "A" will not
2636 	 * notice.  That's what we are validating here via the
2637 	 * stale_bundle() check.
2638 	 *
2639 	 * When a policy's bundle is pruned, we dst_free() the XFRM
2640 	 * dst which causes it's ->obsolete field to be set to
2641 	 * DST_OBSOLETE_DEAD.  If an XFRM dst has been pruned like
2642 	 * this, we want to force a new route lookup.
2643 	 */
2644 	if (dst->obsolete < 0 && !stale_bundle(dst))
2645 		return dst;
2646 
2647 	return NULL;
2648 }
2649 
2650 static int stale_bundle(struct dst_entry *dst)
2651 {
2652 	return !xfrm_bundle_ok((struct xfrm_dst *)dst);
2653 }
2654 
2655 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
2656 {
2657 	while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
2658 		dst->dev = dev_net(dev)->loopback_dev;
2659 		dev_hold(dst->dev);
2660 		dev_put(dev);
2661 	}
2662 }
2663 EXPORT_SYMBOL(xfrm_dst_ifdown);
2664 
2665 static void xfrm_link_failure(struct sk_buff *skb)
2666 {
2667 	/* Impossible. Such dst must be popped before reaches point of failure. */
2668 }
2669 
2670 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
2671 {
2672 	if (dst) {
2673 		if (dst->obsolete) {
2674 			dst_release(dst);
2675 			dst = NULL;
2676 		}
2677 	}
2678 	return dst;
2679 }
2680 
2681 void xfrm_garbage_collect(struct net *net)
2682 {
2683 	flow_cache_flush(net);
2684 }
2685 EXPORT_SYMBOL(xfrm_garbage_collect);
2686 
2687 void xfrm_garbage_collect_deferred(struct net *net)
2688 {
2689 	flow_cache_flush_deferred(net);
2690 }
2691 EXPORT_SYMBOL(xfrm_garbage_collect_deferred);
2692 
2693 static void xfrm_init_pmtu(struct dst_entry *dst)
2694 {
2695 	do {
2696 		struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2697 		u32 pmtu, route_mtu_cached;
2698 
2699 		pmtu = dst_mtu(dst->child);
2700 		xdst->child_mtu_cached = pmtu;
2701 
2702 		pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
2703 
2704 		route_mtu_cached = dst_mtu(xdst->route);
2705 		xdst->route_mtu_cached = route_mtu_cached;
2706 
2707 		if (pmtu > route_mtu_cached)
2708 			pmtu = route_mtu_cached;
2709 
2710 		dst_metric_set(dst, RTAX_MTU, pmtu);
2711 	} while ((dst = dst->next));
2712 }
2713 
2714 /* Check that the bundle accepts the flow and its components are
2715  * still valid.
2716  */
2717 
2718 static int xfrm_bundle_ok(struct xfrm_dst *first)
2719 {
2720 	struct dst_entry *dst = &first->u.dst;
2721 	struct xfrm_dst *last;
2722 	u32 mtu;
2723 
2724 	if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) ||
2725 	    (dst->dev && !netif_running(dst->dev)))
2726 		return 0;
2727 
2728 	if (dst->flags & DST_XFRM_QUEUE)
2729 		return 1;
2730 
2731 	last = NULL;
2732 
2733 	do {
2734 		struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2735 
2736 		if (dst->xfrm->km.state != XFRM_STATE_VALID)
2737 			return 0;
2738 		if (xdst->xfrm_genid != dst->xfrm->genid)
2739 			return 0;
2740 		if (xdst->num_pols > 0 &&
2741 		    xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
2742 			return 0;
2743 
2744 		mtu = dst_mtu(dst->child);
2745 		if (xdst->child_mtu_cached != mtu) {
2746 			last = xdst;
2747 			xdst->child_mtu_cached = mtu;
2748 		}
2749 
2750 		if (!dst_check(xdst->route, xdst->route_cookie))
2751 			return 0;
2752 		mtu = dst_mtu(xdst->route);
2753 		if (xdst->route_mtu_cached != mtu) {
2754 			last = xdst;
2755 			xdst->route_mtu_cached = mtu;
2756 		}
2757 
2758 		dst = dst->child;
2759 	} while (dst->xfrm);
2760 
2761 	if (likely(!last))
2762 		return 1;
2763 
2764 	mtu = last->child_mtu_cached;
2765 	for (;;) {
2766 		dst = &last->u.dst;
2767 
2768 		mtu = xfrm_state_mtu(dst->xfrm, mtu);
2769 		if (mtu > last->route_mtu_cached)
2770 			mtu = last->route_mtu_cached;
2771 		dst_metric_set(dst, RTAX_MTU, mtu);
2772 
2773 		if (last == first)
2774 			break;
2775 
2776 		last = (struct xfrm_dst *)last->u.dst.next;
2777 		last->child_mtu_cached = mtu;
2778 	}
2779 
2780 	return 1;
2781 }
2782 
2783 static unsigned int xfrm_default_advmss(const struct dst_entry *dst)
2784 {
2785 	return dst_metric_advmss(dst->path);
2786 }
2787 
2788 static unsigned int xfrm_mtu(const struct dst_entry *dst)
2789 {
2790 	unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2791 
2792 	return mtu ? : dst_mtu(dst->path);
2793 }
2794 
2795 static const void *xfrm_get_dst_nexthop(const struct dst_entry *dst,
2796 					const void *daddr)
2797 {
2798 	const struct dst_entry *path = dst->path;
2799 
2800 	for (; dst != path; dst = dst->child) {
2801 		const struct xfrm_state *xfrm = dst->xfrm;
2802 
2803 		if (xfrm->props.mode == XFRM_MODE_TRANSPORT)
2804 			continue;
2805 		if (xfrm->type->flags & XFRM_TYPE_REMOTE_COADDR)
2806 			daddr = xfrm->coaddr;
2807 		else if (!(xfrm->type->flags & XFRM_TYPE_LOCAL_COADDR))
2808 			daddr = &xfrm->id.daddr;
2809 	}
2810 	return daddr;
2811 }
2812 
2813 static struct neighbour *xfrm_neigh_lookup(const struct dst_entry *dst,
2814 					   struct sk_buff *skb,
2815 					   const void *daddr)
2816 {
2817 	const struct dst_entry *path = dst->path;
2818 
2819 	if (!skb)
2820 		daddr = xfrm_get_dst_nexthop(dst, daddr);
2821 	return path->ops->neigh_lookup(path, skb, daddr);
2822 }
2823 
2824 static void xfrm_confirm_neigh(const struct dst_entry *dst, const void *daddr)
2825 {
2826 	const struct dst_entry *path = dst->path;
2827 
2828 	daddr = xfrm_get_dst_nexthop(dst, daddr);
2829 	path->ops->confirm_neigh(path, daddr);
2830 }
2831 
2832 int xfrm_policy_register_afinfo(const struct xfrm_policy_afinfo *afinfo, int family)
2833 {
2834 	int err = 0;
2835 
2836 	if (WARN_ON(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
2837 		return -EAFNOSUPPORT;
2838 
2839 	spin_lock(&xfrm_policy_afinfo_lock);
2840 	if (unlikely(xfrm_policy_afinfo[family] != NULL))
2841 		err = -EEXIST;
2842 	else {
2843 		struct dst_ops *dst_ops = afinfo->dst_ops;
2844 		if (likely(dst_ops->kmem_cachep == NULL))
2845 			dst_ops->kmem_cachep = xfrm_dst_cache;
2846 		if (likely(dst_ops->check == NULL))
2847 			dst_ops->check = xfrm_dst_check;
2848 		if (likely(dst_ops->default_advmss == NULL))
2849 			dst_ops->default_advmss = xfrm_default_advmss;
2850 		if (likely(dst_ops->mtu == NULL))
2851 			dst_ops->mtu = xfrm_mtu;
2852 		if (likely(dst_ops->negative_advice == NULL))
2853 			dst_ops->negative_advice = xfrm_negative_advice;
2854 		if (likely(dst_ops->link_failure == NULL))
2855 			dst_ops->link_failure = xfrm_link_failure;
2856 		if (likely(dst_ops->neigh_lookup == NULL))
2857 			dst_ops->neigh_lookup = xfrm_neigh_lookup;
2858 		if (likely(!dst_ops->confirm_neigh))
2859 			dst_ops->confirm_neigh = xfrm_confirm_neigh;
2860 		rcu_assign_pointer(xfrm_policy_afinfo[family], afinfo);
2861 	}
2862 	spin_unlock(&xfrm_policy_afinfo_lock);
2863 
2864 	return err;
2865 }
2866 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
2867 
2868 void xfrm_policy_unregister_afinfo(const struct xfrm_policy_afinfo *afinfo)
2869 {
2870 	struct dst_ops *dst_ops = afinfo->dst_ops;
2871 	int i;
2872 
2873 	for (i = 0; i < ARRAY_SIZE(xfrm_policy_afinfo); i++) {
2874 		if (xfrm_policy_afinfo[i] != afinfo)
2875 			continue;
2876 		RCU_INIT_POINTER(xfrm_policy_afinfo[i], NULL);
2877 		break;
2878 	}
2879 
2880 	synchronize_rcu();
2881 
2882 	dst_ops->kmem_cachep = NULL;
2883 	dst_ops->check = NULL;
2884 	dst_ops->negative_advice = NULL;
2885 	dst_ops->link_failure = NULL;
2886 }
2887 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
2888 
2889 #ifdef CONFIG_XFRM_STATISTICS
2890 static int __net_init xfrm_statistics_init(struct net *net)
2891 {
2892 	int rv;
2893 	net->mib.xfrm_statistics = alloc_percpu(struct linux_xfrm_mib);
2894 	if (!net->mib.xfrm_statistics)
2895 		return -ENOMEM;
2896 	rv = xfrm_proc_init(net);
2897 	if (rv < 0)
2898 		free_percpu(net->mib.xfrm_statistics);
2899 	return rv;
2900 }
2901 
2902 static void xfrm_statistics_fini(struct net *net)
2903 {
2904 	xfrm_proc_fini(net);
2905 	free_percpu(net->mib.xfrm_statistics);
2906 }
2907 #else
2908 static int __net_init xfrm_statistics_init(struct net *net)
2909 {
2910 	return 0;
2911 }
2912 
2913 static void xfrm_statistics_fini(struct net *net)
2914 {
2915 }
2916 #endif
2917 
2918 static int __net_init xfrm_policy_init(struct net *net)
2919 {
2920 	unsigned int hmask, sz;
2921 	int dir;
2922 
2923 	if (net_eq(net, &init_net))
2924 		xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
2925 					   sizeof(struct xfrm_dst),
2926 					   0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
2927 					   NULL);
2928 
2929 	hmask = 8 - 1;
2930 	sz = (hmask+1) * sizeof(struct hlist_head);
2931 
2932 	net->xfrm.policy_byidx = xfrm_hash_alloc(sz);
2933 	if (!net->xfrm.policy_byidx)
2934 		goto out_byidx;
2935 	net->xfrm.policy_idx_hmask = hmask;
2936 
2937 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
2938 		struct xfrm_policy_hash *htab;
2939 
2940 		net->xfrm.policy_count[dir] = 0;
2941 		net->xfrm.policy_count[XFRM_POLICY_MAX + dir] = 0;
2942 		INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
2943 
2944 		htab = &net->xfrm.policy_bydst[dir];
2945 		htab->table = xfrm_hash_alloc(sz);
2946 		if (!htab->table)
2947 			goto out_bydst;
2948 		htab->hmask = hmask;
2949 		htab->dbits4 = 32;
2950 		htab->sbits4 = 32;
2951 		htab->dbits6 = 128;
2952 		htab->sbits6 = 128;
2953 	}
2954 	net->xfrm.policy_hthresh.lbits4 = 32;
2955 	net->xfrm.policy_hthresh.rbits4 = 32;
2956 	net->xfrm.policy_hthresh.lbits6 = 128;
2957 	net->xfrm.policy_hthresh.rbits6 = 128;
2958 
2959 	seqlock_init(&net->xfrm.policy_hthresh.lock);
2960 
2961 	INIT_LIST_HEAD(&net->xfrm.policy_all);
2962 	INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
2963 	INIT_WORK(&net->xfrm.policy_hthresh.work, xfrm_hash_rebuild);
2964 	if (net_eq(net, &init_net))
2965 		xfrm_dev_init();
2966 	return 0;
2967 
2968 out_bydst:
2969 	for (dir--; dir >= 0; dir--) {
2970 		struct xfrm_policy_hash *htab;
2971 
2972 		htab = &net->xfrm.policy_bydst[dir];
2973 		xfrm_hash_free(htab->table, sz);
2974 	}
2975 	xfrm_hash_free(net->xfrm.policy_byidx, sz);
2976 out_byidx:
2977 	return -ENOMEM;
2978 }
2979 
2980 static void xfrm_policy_fini(struct net *net)
2981 {
2982 	unsigned int sz;
2983 	int dir;
2984 
2985 	flush_work(&net->xfrm.policy_hash_work);
2986 #ifdef CONFIG_XFRM_SUB_POLICY
2987 	xfrm_policy_flush(net, XFRM_POLICY_TYPE_SUB, false);
2988 #endif
2989 	xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, false);
2990 
2991 	WARN_ON(!list_empty(&net->xfrm.policy_all));
2992 
2993 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
2994 		struct xfrm_policy_hash *htab;
2995 
2996 		WARN_ON(!hlist_empty(&net->xfrm.policy_inexact[dir]));
2997 
2998 		htab = &net->xfrm.policy_bydst[dir];
2999 		sz = (htab->hmask + 1) * sizeof(struct hlist_head);
3000 		WARN_ON(!hlist_empty(htab->table));
3001 		xfrm_hash_free(htab->table, sz);
3002 	}
3003 
3004 	sz = (net->xfrm.policy_idx_hmask + 1) * sizeof(struct hlist_head);
3005 	WARN_ON(!hlist_empty(net->xfrm.policy_byidx));
3006 	xfrm_hash_free(net->xfrm.policy_byidx, sz);
3007 }
3008 
3009 static int __net_init xfrm_net_init(struct net *net)
3010 {
3011 	int rv;
3012 
3013 	/* Initialize the per-net locks here */
3014 	spin_lock_init(&net->xfrm.xfrm_state_lock);
3015 	spin_lock_init(&net->xfrm.xfrm_policy_lock);
3016 	mutex_init(&net->xfrm.xfrm_cfg_mutex);
3017 
3018 	rv = xfrm_statistics_init(net);
3019 	if (rv < 0)
3020 		goto out_statistics;
3021 	rv = xfrm_state_init(net);
3022 	if (rv < 0)
3023 		goto out_state;
3024 	rv = xfrm_policy_init(net);
3025 	if (rv < 0)
3026 		goto out_policy;
3027 	rv = xfrm_sysctl_init(net);
3028 	if (rv < 0)
3029 		goto out_sysctl;
3030 	rv = flow_cache_init(net);
3031 	if (rv < 0)
3032 		goto out;
3033 
3034 	return 0;
3035 
3036 out:
3037 	xfrm_sysctl_fini(net);
3038 out_sysctl:
3039 	xfrm_policy_fini(net);
3040 out_policy:
3041 	xfrm_state_fini(net);
3042 out_state:
3043 	xfrm_statistics_fini(net);
3044 out_statistics:
3045 	return rv;
3046 }
3047 
3048 static void __net_exit xfrm_net_exit(struct net *net)
3049 {
3050 	flow_cache_fini(net);
3051 	xfrm_sysctl_fini(net);
3052 	xfrm_policy_fini(net);
3053 	xfrm_state_fini(net);
3054 	xfrm_statistics_fini(net);
3055 }
3056 
3057 static struct pernet_operations __net_initdata xfrm_net_ops = {
3058 	.init = xfrm_net_init,
3059 	.exit = xfrm_net_exit,
3060 };
3061 
3062 void __init xfrm_init(void)
3063 {
3064 	flow_cache_hp_init();
3065 	register_pernet_subsys(&xfrm_net_ops);
3066 	seqcount_init(&xfrm_policy_hash_generation);
3067 	xfrm_input_init();
3068 }
3069 
3070 #ifdef CONFIG_AUDITSYSCALL
3071 static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
3072 					 struct audit_buffer *audit_buf)
3073 {
3074 	struct xfrm_sec_ctx *ctx = xp->security;
3075 	struct xfrm_selector *sel = &xp->selector;
3076 
3077 	if (ctx)
3078 		audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
3079 				 ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str);
3080 
3081 	switch (sel->family) {
3082 	case AF_INET:
3083 		audit_log_format(audit_buf, " src=%pI4", &sel->saddr.a4);
3084 		if (sel->prefixlen_s != 32)
3085 			audit_log_format(audit_buf, " src_prefixlen=%d",
3086 					 sel->prefixlen_s);
3087 		audit_log_format(audit_buf, " dst=%pI4", &sel->daddr.a4);
3088 		if (sel->prefixlen_d != 32)
3089 			audit_log_format(audit_buf, " dst_prefixlen=%d",
3090 					 sel->prefixlen_d);
3091 		break;
3092 	case AF_INET6:
3093 		audit_log_format(audit_buf, " src=%pI6", sel->saddr.a6);
3094 		if (sel->prefixlen_s != 128)
3095 			audit_log_format(audit_buf, " src_prefixlen=%d",
3096 					 sel->prefixlen_s);
3097 		audit_log_format(audit_buf, " dst=%pI6", sel->daddr.a6);
3098 		if (sel->prefixlen_d != 128)
3099 			audit_log_format(audit_buf, " dst_prefixlen=%d",
3100 					 sel->prefixlen_d);
3101 		break;
3102 	}
3103 }
3104 
3105 void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid)
3106 {
3107 	struct audit_buffer *audit_buf;
3108 
3109 	audit_buf = xfrm_audit_start("SPD-add");
3110 	if (audit_buf == NULL)
3111 		return;
3112 	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
3113 	audit_log_format(audit_buf, " res=%u", result);
3114 	xfrm_audit_common_policyinfo(xp, audit_buf);
3115 	audit_log_end(audit_buf);
3116 }
3117 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
3118 
3119 void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
3120 			      bool task_valid)
3121 {
3122 	struct audit_buffer *audit_buf;
3123 
3124 	audit_buf = xfrm_audit_start("SPD-delete");
3125 	if (audit_buf == NULL)
3126 		return;
3127 	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
3128 	audit_log_format(audit_buf, " res=%u", result);
3129 	xfrm_audit_common_policyinfo(xp, audit_buf);
3130 	audit_log_end(audit_buf);
3131 }
3132 EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
3133 #endif
3134 
3135 #ifdef CONFIG_XFRM_MIGRATE
3136 static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp,
3137 					const struct xfrm_selector *sel_tgt)
3138 {
3139 	if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
3140 		if (sel_tgt->family == sel_cmp->family &&
3141 		    xfrm_addr_equal(&sel_tgt->daddr, &sel_cmp->daddr,
3142 				    sel_cmp->family) &&
3143 		    xfrm_addr_equal(&sel_tgt->saddr, &sel_cmp->saddr,
3144 				    sel_cmp->family) &&
3145 		    sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
3146 		    sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
3147 			return true;
3148 		}
3149 	} else {
3150 		if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
3151 			return true;
3152 		}
3153 	}
3154 	return false;
3155 }
3156 
3157 static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector *sel,
3158 						    u8 dir, u8 type, struct net *net)
3159 {
3160 	struct xfrm_policy *pol, *ret = NULL;
3161 	struct hlist_head *chain;
3162 	u32 priority = ~0U;
3163 
3164 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
3165 	chain = policy_hash_direct(net, &sel->daddr, &sel->saddr, sel->family, dir);
3166 	hlist_for_each_entry(pol, chain, bydst) {
3167 		if (xfrm_migrate_selector_match(sel, &pol->selector) &&
3168 		    pol->type == type) {
3169 			ret = pol;
3170 			priority = ret->priority;
3171 			break;
3172 		}
3173 	}
3174 	chain = &net->xfrm.policy_inexact[dir];
3175 	hlist_for_each_entry(pol, chain, bydst) {
3176 		if ((pol->priority >= priority) && ret)
3177 			break;
3178 
3179 		if (xfrm_migrate_selector_match(sel, &pol->selector) &&
3180 		    pol->type == type) {
3181 			ret = pol;
3182 			break;
3183 		}
3184 	}
3185 
3186 	xfrm_pol_hold(ret);
3187 
3188 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
3189 
3190 	return ret;
3191 }
3192 
3193 static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t)
3194 {
3195 	int match = 0;
3196 
3197 	if (t->mode == m->mode && t->id.proto == m->proto &&
3198 	    (m->reqid == 0 || t->reqid == m->reqid)) {
3199 		switch (t->mode) {
3200 		case XFRM_MODE_TUNNEL:
3201 		case XFRM_MODE_BEET:
3202 			if (xfrm_addr_equal(&t->id.daddr, &m->old_daddr,
3203 					    m->old_family) &&
3204 			    xfrm_addr_equal(&t->saddr, &m->old_saddr,
3205 					    m->old_family)) {
3206 				match = 1;
3207 			}
3208 			break;
3209 		case XFRM_MODE_TRANSPORT:
3210 			/* in case of transport mode, template does not store
3211 			   any IP addresses, hence we just compare mode and
3212 			   protocol */
3213 			match = 1;
3214 			break;
3215 		default:
3216 			break;
3217 		}
3218 	}
3219 	return match;
3220 }
3221 
3222 /* update endpoint address(es) of template(s) */
3223 static int xfrm_policy_migrate(struct xfrm_policy *pol,
3224 			       struct xfrm_migrate *m, int num_migrate)
3225 {
3226 	struct xfrm_migrate *mp;
3227 	int i, j, n = 0;
3228 
3229 	write_lock_bh(&pol->lock);
3230 	if (unlikely(pol->walk.dead)) {
3231 		/* target policy has been deleted */
3232 		write_unlock_bh(&pol->lock);
3233 		return -ENOENT;
3234 	}
3235 
3236 	for (i = 0; i < pol->xfrm_nr; i++) {
3237 		for (j = 0, mp = m; j < num_migrate; j++, mp++) {
3238 			if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
3239 				continue;
3240 			n++;
3241 			if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
3242 			    pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
3243 				continue;
3244 			/* update endpoints */
3245 			memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
3246 			       sizeof(pol->xfrm_vec[i].id.daddr));
3247 			memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
3248 			       sizeof(pol->xfrm_vec[i].saddr));
3249 			pol->xfrm_vec[i].encap_family = mp->new_family;
3250 			/* flush bundles */
3251 			atomic_inc(&pol->genid);
3252 		}
3253 	}
3254 
3255 	write_unlock_bh(&pol->lock);
3256 
3257 	if (!n)
3258 		return -ENODATA;
3259 
3260 	return 0;
3261 }
3262 
3263 static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate)
3264 {
3265 	int i, j;
3266 
3267 	if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
3268 		return -EINVAL;
3269 
3270 	for (i = 0; i < num_migrate; i++) {
3271 		if (xfrm_addr_equal(&m[i].old_daddr, &m[i].new_daddr,
3272 				    m[i].old_family) &&
3273 		    xfrm_addr_equal(&m[i].old_saddr, &m[i].new_saddr,
3274 				    m[i].old_family))
3275 			return -EINVAL;
3276 		if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
3277 		    xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
3278 			return -EINVAL;
3279 
3280 		/* check if there is any duplicated entry */
3281 		for (j = i + 1; j < num_migrate; j++) {
3282 			if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
3283 				    sizeof(m[i].old_daddr)) &&
3284 			    !memcmp(&m[i].old_saddr, &m[j].old_saddr,
3285 				    sizeof(m[i].old_saddr)) &&
3286 			    m[i].proto == m[j].proto &&
3287 			    m[i].mode == m[j].mode &&
3288 			    m[i].reqid == m[j].reqid &&
3289 			    m[i].old_family == m[j].old_family)
3290 				return -EINVAL;
3291 		}
3292 	}
3293 
3294 	return 0;
3295 }
3296 
3297 int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
3298 		 struct xfrm_migrate *m, int num_migrate,
3299 		 struct xfrm_kmaddress *k, struct net *net)
3300 {
3301 	int i, err, nx_cur = 0, nx_new = 0;
3302 	struct xfrm_policy *pol = NULL;
3303 	struct xfrm_state *x, *xc;
3304 	struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
3305 	struct xfrm_state *x_new[XFRM_MAX_DEPTH];
3306 	struct xfrm_migrate *mp;
3307 
3308 	if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
3309 		goto out;
3310 
3311 	/* Stage 1 - find policy */
3312 	if ((pol = xfrm_migrate_policy_find(sel, dir, type, net)) == NULL) {
3313 		err = -ENOENT;
3314 		goto out;
3315 	}
3316 
3317 	/* Stage 2 - find and update state(s) */
3318 	for (i = 0, mp = m; i < num_migrate; i++, mp++) {
3319 		if ((x = xfrm_migrate_state_find(mp, net))) {
3320 			x_cur[nx_cur] = x;
3321 			nx_cur++;
3322 			if ((xc = xfrm_state_migrate(x, mp))) {
3323 				x_new[nx_new] = xc;
3324 				nx_new++;
3325 			} else {
3326 				err = -ENODATA;
3327 				goto restore_state;
3328 			}
3329 		}
3330 	}
3331 
3332 	/* Stage 3 - update policy */
3333 	if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
3334 		goto restore_state;
3335 
3336 	/* Stage 4 - delete old state(s) */
3337 	if (nx_cur) {
3338 		xfrm_states_put(x_cur, nx_cur);
3339 		xfrm_states_delete(x_cur, nx_cur);
3340 	}
3341 
3342 	/* Stage 5 - announce */
3343 	km_migrate(sel, dir, type, m, num_migrate, k);
3344 
3345 	xfrm_pol_put(pol);
3346 
3347 	return 0;
3348 out:
3349 	return err;
3350 
3351 restore_state:
3352 	if (pol)
3353 		xfrm_pol_put(pol);
3354 	if (nx_cur)
3355 		xfrm_states_put(x_cur, nx_cur);
3356 	if (nx_new)
3357 		xfrm_states_delete(x_new, nx_new);
3358 
3359 	return err;
3360 }
3361 EXPORT_SYMBOL(xfrm_migrate);
3362 #endif
3363