xref: /linux/net/xfrm/xfrm_policy.c (revision bd628c1bed7902ec1f24ba0fe70758949146abbe)
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/cpu.h>
28 #include <linux/audit.h>
29 #include <linux/rhashtable.h>
30 #include <net/dst.h>
31 #include <net/flow.h>
32 #include <net/xfrm.h>
33 #include <net/ip.h>
34 #ifdef CONFIG_XFRM_STATISTICS
35 #include <net/snmp.h>
36 #endif
37 
38 #include "xfrm_hash.h"
39 
40 #define XFRM_QUEUE_TMO_MIN ((unsigned)(HZ/10))
41 #define XFRM_QUEUE_TMO_MAX ((unsigned)(60*HZ))
42 #define XFRM_MAX_QUEUE_LEN	100
43 
44 struct xfrm_flo {
45 	struct dst_entry *dst_orig;
46 	u8 flags;
47 };
48 
49 /* prefixes smaller than this are stored in lists, not trees. */
50 #define INEXACT_PREFIXLEN_IPV4	16
51 #define INEXACT_PREFIXLEN_IPV6	48
52 
53 struct xfrm_pol_inexact_node {
54 	struct rb_node node;
55 	union {
56 		xfrm_address_t addr;
57 		struct rcu_head rcu;
58 	};
59 	u8 prefixlen;
60 
61 	struct rb_root root;
62 
63 	/* the policies matching this node, can be empty list */
64 	struct hlist_head hhead;
65 };
66 
67 /* xfrm inexact policy search tree:
68  * xfrm_pol_inexact_bin = hash(dir,type,family,if_id);
69  *  |
70  * +---- root_d: sorted by daddr:prefix
71  * |                 |
72  * |        xfrm_pol_inexact_node
73  * |                 |
74  * |                 +- root: sorted by saddr/prefix
75  * |                 |              |
76  * |                 |         xfrm_pol_inexact_node
77  * |                 |              |
78  * |                 |              + root: unused
79  * |                 |              |
80  * |                 |              + hhead: saddr:daddr policies
81  * |                 |
82  * |                 +- coarse policies and all any:daddr policies
83  * |
84  * +---- root_s: sorted by saddr:prefix
85  * |                 |
86  * |        xfrm_pol_inexact_node
87  * |                 |
88  * |                 + root: unused
89  * |                 |
90  * |                 + hhead: saddr:any policies
91  * |
92  * +---- coarse policies and all any:any policies
93  *
94  * Lookups return four candidate lists:
95  * 1. any:any list from top-level xfrm_pol_inexact_bin
96  * 2. any:daddr list from daddr tree
97  * 3. saddr:daddr list from 2nd level daddr tree
98  * 4. saddr:any list from saddr tree
99  *
100  * This result set then needs to be searched for the policy with
101  * the lowest priority.  If two results have same prio, youngest one wins.
102  */
103 
104 struct xfrm_pol_inexact_key {
105 	possible_net_t net;
106 	u32 if_id;
107 	u16 family;
108 	u8 dir, type;
109 };
110 
111 struct xfrm_pol_inexact_bin {
112 	struct xfrm_pol_inexact_key k;
113 	struct rhash_head head;
114 	/* list containing '*:*' policies */
115 	struct hlist_head hhead;
116 
117 	seqcount_t count;
118 	/* tree sorted by daddr/prefix */
119 	struct rb_root root_d;
120 
121 	/* tree sorted by saddr/prefix */
122 	struct rb_root root_s;
123 
124 	/* slow path below */
125 	struct list_head inexact_bins;
126 	struct rcu_head rcu;
127 };
128 
129 enum xfrm_pol_inexact_candidate_type {
130 	XFRM_POL_CAND_BOTH,
131 	XFRM_POL_CAND_SADDR,
132 	XFRM_POL_CAND_DADDR,
133 	XFRM_POL_CAND_ANY,
134 
135 	XFRM_POL_CAND_MAX,
136 };
137 
138 struct xfrm_pol_inexact_candidates {
139 	struct hlist_head *res[XFRM_POL_CAND_MAX];
140 };
141 
142 static DEFINE_SPINLOCK(xfrm_if_cb_lock);
143 static struct xfrm_if_cb const __rcu *xfrm_if_cb __read_mostly;
144 
145 static DEFINE_SPINLOCK(xfrm_policy_afinfo_lock);
146 static struct xfrm_policy_afinfo const __rcu *xfrm_policy_afinfo[AF_INET6 + 1]
147 						__read_mostly;
148 
149 static struct kmem_cache *xfrm_dst_cache __ro_after_init;
150 static __read_mostly seqcount_t xfrm_policy_hash_generation;
151 
152 static struct rhashtable xfrm_policy_inexact_table;
153 static const struct rhashtable_params xfrm_pol_inexact_params;
154 
155 static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr);
156 static int stale_bundle(struct dst_entry *dst);
157 static int xfrm_bundle_ok(struct xfrm_dst *xdst);
158 static void xfrm_policy_queue_process(struct timer_list *t);
159 
160 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir);
161 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
162 						int dir);
163 
164 static struct xfrm_pol_inexact_bin *
165 xfrm_policy_inexact_lookup(struct net *net, u8 type, u16 family, u8 dir,
166 			   u32 if_id);
167 
168 static struct xfrm_pol_inexact_bin *
169 xfrm_policy_inexact_lookup_rcu(struct net *net,
170 			       u8 type, u16 family, u8 dir, u32 if_id);
171 static struct xfrm_policy *
172 xfrm_policy_insert_list(struct hlist_head *chain, struct xfrm_policy *policy,
173 			bool excl);
174 static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
175 					    struct xfrm_policy *policy);
176 
177 static bool
178 xfrm_policy_find_inexact_candidates(struct xfrm_pol_inexact_candidates *cand,
179 				    struct xfrm_pol_inexact_bin *b,
180 				    const xfrm_address_t *saddr,
181 				    const xfrm_address_t *daddr);
182 
183 static inline bool xfrm_pol_hold_rcu(struct xfrm_policy *policy)
184 {
185 	return refcount_inc_not_zero(&policy->refcnt);
186 }
187 
188 static inline bool
189 __xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
190 {
191 	const struct flowi4 *fl4 = &fl->u.ip4;
192 
193 	return  addr4_match(fl4->daddr, sel->daddr.a4, sel->prefixlen_d) &&
194 		addr4_match(fl4->saddr, sel->saddr.a4, sel->prefixlen_s) &&
195 		!((xfrm_flowi_dport(fl, &fl4->uli) ^ sel->dport) & sel->dport_mask) &&
196 		!((xfrm_flowi_sport(fl, &fl4->uli) ^ sel->sport) & sel->sport_mask) &&
197 		(fl4->flowi4_proto == sel->proto || !sel->proto) &&
198 		(fl4->flowi4_oif == sel->ifindex || !sel->ifindex);
199 }
200 
201 static inline bool
202 __xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
203 {
204 	const struct flowi6 *fl6 = &fl->u.ip6;
205 
206 	return  addr_match(&fl6->daddr, &sel->daddr, sel->prefixlen_d) &&
207 		addr_match(&fl6->saddr, &sel->saddr, sel->prefixlen_s) &&
208 		!((xfrm_flowi_dport(fl, &fl6->uli) ^ sel->dport) & sel->dport_mask) &&
209 		!((xfrm_flowi_sport(fl, &fl6->uli) ^ sel->sport) & sel->sport_mask) &&
210 		(fl6->flowi6_proto == sel->proto || !sel->proto) &&
211 		(fl6->flowi6_oif == sel->ifindex || !sel->ifindex);
212 }
213 
214 bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl,
215 			 unsigned short family)
216 {
217 	switch (family) {
218 	case AF_INET:
219 		return __xfrm4_selector_match(sel, fl);
220 	case AF_INET6:
221 		return __xfrm6_selector_match(sel, fl);
222 	}
223 	return false;
224 }
225 
226 static const struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
227 {
228 	const struct xfrm_policy_afinfo *afinfo;
229 
230 	if (unlikely(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
231 		return NULL;
232 	rcu_read_lock();
233 	afinfo = rcu_dereference(xfrm_policy_afinfo[family]);
234 	if (unlikely(!afinfo))
235 		rcu_read_unlock();
236 	return afinfo;
237 }
238 
239 /* Called with rcu_read_lock(). */
240 static const struct xfrm_if_cb *xfrm_if_get_cb(void)
241 {
242 	return rcu_dereference(xfrm_if_cb);
243 }
244 
245 struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos, int oif,
246 				    const xfrm_address_t *saddr,
247 				    const xfrm_address_t *daddr,
248 				    int family, u32 mark)
249 {
250 	const struct xfrm_policy_afinfo *afinfo;
251 	struct dst_entry *dst;
252 
253 	afinfo = xfrm_policy_get_afinfo(family);
254 	if (unlikely(afinfo == NULL))
255 		return ERR_PTR(-EAFNOSUPPORT);
256 
257 	dst = afinfo->dst_lookup(net, tos, oif, saddr, daddr, mark);
258 
259 	rcu_read_unlock();
260 
261 	return dst;
262 }
263 EXPORT_SYMBOL(__xfrm_dst_lookup);
264 
265 static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x,
266 						int tos, int oif,
267 						xfrm_address_t *prev_saddr,
268 						xfrm_address_t *prev_daddr,
269 						int family, u32 mark)
270 {
271 	struct net *net = xs_net(x);
272 	xfrm_address_t *saddr = &x->props.saddr;
273 	xfrm_address_t *daddr = &x->id.daddr;
274 	struct dst_entry *dst;
275 
276 	if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) {
277 		saddr = x->coaddr;
278 		daddr = prev_daddr;
279 	}
280 	if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) {
281 		saddr = prev_saddr;
282 		daddr = x->coaddr;
283 	}
284 
285 	dst = __xfrm_dst_lookup(net, tos, oif, saddr, daddr, family, mark);
286 
287 	if (!IS_ERR(dst)) {
288 		if (prev_saddr != saddr)
289 			memcpy(prev_saddr, saddr,  sizeof(*prev_saddr));
290 		if (prev_daddr != daddr)
291 			memcpy(prev_daddr, daddr,  sizeof(*prev_daddr));
292 	}
293 
294 	return dst;
295 }
296 
297 static inline unsigned long make_jiffies(long secs)
298 {
299 	if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
300 		return MAX_SCHEDULE_TIMEOUT-1;
301 	else
302 		return secs*HZ;
303 }
304 
305 static void xfrm_policy_timer(struct timer_list *t)
306 {
307 	struct xfrm_policy *xp = from_timer(xp, t, timer);
308 	time64_t now = ktime_get_real_seconds();
309 	time64_t next = TIME64_MAX;
310 	int warn = 0;
311 	int dir;
312 
313 	read_lock(&xp->lock);
314 
315 	if (unlikely(xp->walk.dead))
316 		goto out;
317 
318 	dir = xfrm_policy_id2dir(xp->index);
319 
320 	if (xp->lft.hard_add_expires_seconds) {
321 		time64_t tmo = xp->lft.hard_add_expires_seconds +
322 			xp->curlft.add_time - now;
323 		if (tmo <= 0)
324 			goto expired;
325 		if (tmo < next)
326 			next = tmo;
327 	}
328 	if (xp->lft.hard_use_expires_seconds) {
329 		time64_t tmo = xp->lft.hard_use_expires_seconds +
330 			(xp->curlft.use_time ? : xp->curlft.add_time) - now;
331 		if (tmo <= 0)
332 			goto expired;
333 		if (tmo < next)
334 			next = tmo;
335 	}
336 	if (xp->lft.soft_add_expires_seconds) {
337 		time64_t tmo = xp->lft.soft_add_expires_seconds +
338 			xp->curlft.add_time - now;
339 		if (tmo <= 0) {
340 			warn = 1;
341 			tmo = XFRM_KM_TIMEOUT;
342 		}
343 		if (tmo < next)
344 			next = tmo;
345 	}
346 	if (xp->lft.soft_use_expires_seconds) {
347 		time64_t tmo = xp->lft.soft_use_expires_seconds +
348 			(xp->curlft.use_time ? : xp->curlft.add_time) - now;
349 		if (tmo <= 0) {
350 			warn = 1;
351 			tmo = XFRM_KM_TIMEOUT;
352 		}
353 		if (tmo < next)
354 			next = tmo;
355 	}
356 
357 	if (warn)
358 		km_policy_expired(xp, dir, 0, 0);
359 	if (next != TIME64_MAX &&
360 	    !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
361 		xfrm_pol_hold(xp);
362 
363 out:
364 	read_unlock(&xp->lock);
365 	xfrm_pol_put(xp);
366 	return;
367 
368 expired:
369 	read_unlock(&xp->lock);
370 	if (!xfrm_policy_delete(xp, dir))
371 		km_policy_expired(xp, dir, 1, 0);
372 	xfrm_pol_put(xp);
373 }
374 
375 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
376  * SPD calls.
377  */
378 
379 struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
380 {
381 	struct xfrm_policy *policy;
382 
383 	policy = kzalloc(sizeof(struct xfrm_policy), gfp);
384 
385 	if (policy) {
386 		write_pnet(&policy->xp_net, net);
387 		INIT_LIST_HEAD(&policy->walk.all);
388 		INIT_HLIST_NODE(&policy->bydst_inexact_list);
389 		INIT_HLIST_NODE(&policy->bydst);
390 		INIT_HLIST_NODE(&policy->byidx);
391 		rwlock_init(&policy->lock);
392 		refcount_set(&policy->refcnt, 1);
393 		skb_queue_head_init(&policy->polq.hold_queue);
394 		timer_setup(&policy->timer, xfrm_policy_timer, 0);
395 		timer_setup(&policy->polq.hold_timer,
396 			    xfrm_policy_queue_process, 0);
397 	}
398 	return policy;
399 }
400 EXPORT_SYMBOL(xfrm_policy_alloc);
401 
402 static void xfrm_policy_destroy_rcu(struct rcu_head *head)
403 {
404 	struct xfrm_policy *policy = container_of(head, struct xfrm_policy, rcu);
405 
406 	security_xfrm_policy_free(policy->security);
407 	kfree(policy);
408 }
409 
410 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
411 
412 void xfrm_policy_destroy(struct xfrm_policy *policy)
413 {
414 	BUG_ON(!policy->walk.dead);
415 
416 	if (del_timer(&policy->timer) || del_timer(&policy->polq.hold_timer))
417 		BUG();
418 
419 	call_rcu(&policy->rcu, xfrm_policy_destroy_rcu);
420 }
421 EXPORT_SYMBOL(xfrm_policy_destroy);
422 
423 /* Rule must be locked. Release descendant resources, announce
424  * entry dead. The rule must be unlinked from lists to the moment.
425  */
426 
427 static void xfrm_policy_kill(struct xfrm_policy *policy)
428 {
429 	policy->walk.dead = 1;
430 
431 	atomic_inc(&policy->genid);
432 
433 	if (del_timer(&policy->polq.hold_timer))
434 		xfrm_pol_put(policy);
435 	skb_queue_purge(&policy->polq.hold_queue);
436 
437 	if (del_timer(&policy->timer))
438 		xfrm_pol_put(policy);
439 
440 	xfrm_pol_put(policy);
441 }
442 
443 static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
444 
445 static inline unsigned int idx_hash(struct net *net, u32 index)
446 {
447 	return __idx_hash(index, net->xfrm.policy_idx_hmask);
448 }
449 
450 /* calculate policy hash thresholds */
451 static void __get_hash_thresh(struct net *net,
452 			      unsigned short family, int dir,
453 			      u8 *dbits, u8 *sbits)
454 {
455 	switch (family) {
456 	case AF_INET:
457 		*dbits = net->xfrm.policy_bydst[dir].dbits4;
458 		*sbits = net->xfrm.policy_bydst[dir].sbits4;
459 		break;
460 
461 	case AF_INET6:
462 		*dbits = net->xfrm.policy_bydst[dir].dbits6;
463 		*sbits = net->xfrm.policy_bydst[dir].sbits6;
464 		break;
465 
466 	default:
467 		*dbits = 0;
468 		*sbits = 0;
469 	}
470 }
471 
472 static struct hlist_head *policy_hash_bysel(struct net *net,
473 					    const struct xfrm_selector *sel,
474 					    unsigned short family, int dir)
475 {
476 	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
477 	unsigned int hash;
478 	u8 dbits;
479 	u8 sbits;
480 
481 	__get_hash_thresh(net, family, dir, &dbits, &sbits);
482 	hash = __sel_hash(sel, family, hmask, dbits, sbits);
483 
484 	if (hash == hmask + 1)
485 		return NULL;
486 
487 	return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
488 		     lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
489 }
490 
491 static struct hlist_head *policy_hash_direct(struct net *net,
492 					     const xfrm_address_t *daddr,
493 					     const xfrm_address_t *saddr,
494 					     unsigned short family, int dir)
495 {
496 	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
497 	unsigned int hash;
498 	u8 dbits;
499 	u8 sbits;
500 
501 	__get_hash_thresh(net, family, dir, &dbits, &sbits);
502 	hash = __addr_hash(daddr, saddr, family, hmask, dbits, sbits);
503 
504 	return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
505 		     lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
506 }
507 
508 static void xfrm_dst_hash_transfer(struct net *net,
509 				   struct hlist_head *list,
510 				   struct hlist_head *ndsttable,
511 				   unsigned int nhashmask,
512 				   int dir)
513 {
514 	struct hlist_node *tmp, *entry0 = NULL;
515 	struct xfrm_policy *pol;
516 	unsigned int h0 = 0;
517 	u8 dbits;
518 	u8 sbits;
519 
520 redo:
521 	hlist_for_each_entry_safe(pol, tmp, list, bydst) {
522 		unsigned int h;
523 
524 		__get_hash_thresh(net, pol->family, dir, &dbits, &sbits);
525 		h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
526 				pol->family, nhashmask, dbits, sbits);
527 		if (!entry0) {
528 			hlist_del_rcu(&pol->bydst);
529 			hlist_add_head_rcu(&pol->bydst, ndsttable + h);
530 			h0 = h;
531 		} else {
532 			if (h != h0)
533 				continue;
534 			hlist_del_rcu(&pol->bydst);
535 			hlist_add_behind_rcu(&pol->bydst, entry0);
536 		}
537 		entry0 = &pol->bydst;
538 	}
539 	if (!hlist_empty(list)) {
540 		entry0 = NULL;
541 		goto redo;
542 	}
543 }
544 
545 static void xfrm_idx_hash_transfer(struct hlist_head *list,
546 				   struct hlist_head *nidxtable,
547 				   unsigned int nhashmask)
548 {
549 	struct hlist_node *tmp;
550 	struct xfrm_policy *pol;
551 
552 	hlist_for_each_entry_safe(pol, tmp, list, byidx) {
553 		unsigned int h;
554 
555 		h = __idx_hash(pol->index, nhashmask);
556 		hlist_add_head(&pol->byidx, nidxtable+h);
557 	}
558 }
559 
560 static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
561 {
562 	return ((old_hmask + 1) << 1) - 1;
563 }
564 
565 static void xfrm_bydst_resize(struct net *net, int dir)
566 {
567 	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
568 	unsigned int nhashmask = xfrm_new_hash_mask(hmask);
569 	unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
570 	struct hlist_head *ndst = xfrm_hash_alloc(nsize);
571 	struct hlist_head *odst;
572 	int i;
573 
574 	if (!ndst)
575 		return;
576 
577 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
578 	write_seqcount_begin(&xfrm_policy_hash_generation);
579 
580 	odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
581 				lockdep_is_held(&net->xfrm.xfrm_policy_lock));
582 
583 	odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
584 				lockdep_is_held(&net->xfrm.xfrm_policy_lock));
585 
586 	for (i = hmask; i >= 0; i--)
587 		xfrm_dst_hash_transfer(net, odst + i, ndst, nhashmask, dir);
588 
589 	rcu_assign_pointer(net->xfrm.policy_bydst[dir].table, ndst);
590 	net->xfrm.policy_bydst[dir].hmask = nhashmask;
591 
592 	write_seqcount_end(&xfrm_policy_hash_generation);
593 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
594 
595 	synchronize_rcu();
596 
597 	xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
598 }
599 
600 static void xfrm_byidx_resize(struct net *net, int total)
601 {
602 	unsigned int hmask = net->xfrm.policy_idx_hmask;
603 	unsigned int nhashmask = xfrm_new_hash_mask(hmask);
604 	unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
605 	struct hlist_head *oidx = net->xfrm.policy_byidx;
606 	struct hlist_head *nidx = xfrm_hash_alloc(nsize);
607 	int i;
608 
609 	if (!nidx)
610 		return;
611 
612 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
613 
614 	for (i = hmask; i >= 0; i--)
615 		xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
616 
617 	net->xfrm.policy_byidx = nidx;
618 	net->xfrm.policy_idx_hmask = nhashmask;
619 
620 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
621 
622 	xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
623 }
624 
625 static inline int xfrm_bydst_should_resize(struct net *net, int dir, int *total)
626 {
627 	unsigned int cnt = net->xfrm.policy_count[dir];
628 	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
629 
630 	if (total)
631 		*total += cnt;
632 
633 	if ((hmask + 1) < xfrm_policy_hashmax &&
634 	    cnt > hmask)
635 		return 1;
636 
637 	return 0;
638 }
639 
640 static inline int xfrm_byidx_should_resize(struct net *net, int total)
641 {
642 	unsigned int hmask = net->xfrm.policy_idx_hmask;
643 
644 	if ((hmask + 1) < xfrm_policy_hashmax &&
645 	    total > hmask)
646 		return 1;
647 
648 	return 0;
649 }
650 
651 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
652 {
653 	si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
654 	si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
655 	si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
656 	si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
657 	si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
658 	si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
659 	si->spdhcnt = net->xfrm.policy_idx_hmask;
660 	si->spdhmcnt = xfrm_policy_hashmax;
661 }
662 EXPORT_SYMBOL(xfrm_spd_getinfo);
663 
664 static DEFINE_MUTEX(hash_resize_mutex);
665 static void xfrm_hash_resize(struct work_struct *work)
666 {
667 	struct net *net = container_of(work, struct net, xfrm.policy_hash_work);
668 	int dir, total;
669 
670 	mutex_lock(&hash_resize_mutex);
671 
672 	total = 0;
673 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
674 		if (xfrm_bydst_should_resize(net, dir, &total))
675 			xfrm_bydst_resize(net, dir);
676 	}
677 	if (xfrm_byidx_should_resize(net, total))
678 		xfrm_byidx_resize(net, total);
679 
680 	mutex_unlock(&hash_resize_mutex);
681 }
682 
683 static void xfrm_hash_reset_inexact_table(struct net *net)
684 {
685 	struct xfrm_pol_inexact_bin *b;
686 
687 	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
688 
689 	list_for_each_entry(b, &net->xfrm.inexact_bins, inexact_bins)
690 		INIT_HLIST_HEAD(&b->hhead);
691 }
692 
693 /* Make sure *pol can be inserted into fastbin.
694  * Useful to check that later insert requests will be sucessful
695  * (provided xfrm_policy_lock is held throughout).
696  */
697 static struct xfrm_pol_inexact_bin *
698 xfrm_policy_inexact_alloc_bin(const struct xfrm_policy *pol, u8 dir)
699 {
700 	struct xfrm_pol_inexact_bin *bin, *prev;
701 	struct xfrm_pol_inexact_key k = {
702 		.family = pol->family,
703 		.type = pol->type,
704 		.dir = dir,
705 		.if_id = pol->if_id,
706 	};
707 	struct net *net = xp_net(pol);
708 
709 	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
710 
711 	write_pnet(&k.net, net);
712 	bin = rhashtable_lookup_fast(&xfrm_policy_inexact_table, &k,
713 				     xfrm_pol_inexact_params);
714 	if (bin)
715 		return bin;
716 
717 	bin = kzalloc(sizeof(*bin), GFP_ATOMIC);
718 	if (!bin)
719 		return NULL;
720 
721 	bin->k = k;
722 	INIT_HLIST_HEAD(&bin->hhead);
723 	bin->root_d = RB_ROOT;
724 	bin->root_s = RB_ROOT;
725 	seqcount_init(&bin->count);
726 
727 	prev = rhashtable_lookup_get_insert_key(&xfrm_policy_inexact_table,
728 						&bin->k, &bin->head,
729 						xfrm_pol_inexact_params);
730 	if (!prev) {
731 		list_add(&bin->inexact_bins, &net->xfrm.inexact_bins);
732 		return bin;
733 	}
734 
735 	kfree(bin);
736 
737 	return IS_ERR(prev) ? NULL : prev;
738 }
739 
740 static bool xfrm_pol_inexact_addr_use_any_list(const xfrm_address_t *addr,
741 					       int family, u8 prefixlen)
742 {
743 	if (xfrm_addr_any(addr, family))
744 		return true;
745 
746 	if (family == AF_INET6 && prefixlen < INEXACT_PREFIXLEN_IPV6)
747 		return true;
748 
749 	if (family == AF_INET && prefixlen < INEXACT_PREFIXLEN_IPV4)
750 		return true;
751 
752 	return false;
753 }
754 
755 static bool
756 xfrm_policy_inexact_insert_use_any_list(const struct xfrm_policy *policy)
757 {
758 	const xfrm_address_t *addr;
759 	bool saddr_any, daddr_any;
760 	u8 prefixlen;
761 
762 	addr = &policy->selector.saddr;
763 	prefixlen = policy->selector.prefixlen_s;
764 
765 	saddr_any = xfrm_pol_inexact_addr_use_any_list(addr,
766 						       policy->family,
767 						       prefixlen);
768 	addr = &policy->selector.daddr;
769 	prefixlen = policy->selector.prefixlen_d;
770 	daddr_any = xfrm_pol_inexact_addr_use_any_list(addr,
771 						       policy->family,
772 						       prefixlen);
773 	return saddr_any && daddr_any;
774 }
775 
776 static void xfrm_pol_inexact_node_init(struct xfrm_pol_inexact_node *node,
777 				       const xfrm_address_t *addr, u8 prefixlen)
778 {
779 	node->addr = *addr;
780 	node->prefixlen = prefixlen;
781 }
782 
783 static struct xfrm_pol_inexact_node *
784 xfrm_pol_inexact_node_alloc(const xfrm_address_t *addr, u8 prefixlen)
785 {
786 	struct xfrm_pol_inexact_node *node;
787 
788 	node = kzalloc(sizeof(*node), GFP_ATOMIC);
789 	if (node)
790 		xfrm_pol_inexact_node_init(node, addr, prefixlen);
791 
792 	return node;
793 }
794 
795 static int xfrm_policy_addr_delta(const xfrm_address_t *a,
796 				  const xfrm_address_t *b,
797 				  u8 prefixlen, u16 family)
798 {
799 	unsigned int pdw, pbi;
800 	int delta = 0;
801 
802 	switch (family) {
803 	case AF_INET:
804 		if (sizeof(long) == 4 && prefixlen == 0)
805 			return ntohl(a->a4) - ntohl(b->a4);
806 		return (ntohl(a->a4) & ((~0UL << (32 - prefixlen)))) -
807 		       (ntohl(b->a4) & ((~0UL << (32 - prefixlen))));
808 	case AF_INET6:
809 		pdw = prefixlen >> 5;
810 		pbi = prefixlen & 0x1f;
811 
812 		if (pdw) {
813 			delta = memcmp(a->a6, b->a6, pdw << 2);
814 			if (delta)
815 				return delta;
816 		}
817 		if (pbi) {
818 			u32 mask = ~0u << (32 - pbi);
819 
820 			delta = (ntohl(a->a6[pdw]) & mask) -
821 				(ntohl(b->a6[pdw]) & mask);
822 		}
823 		break;
824 	default:
825 		break;
826 	}
827 
828 	return delta;
829 }
830 
831 static void xfrm_policy_inexact_list_reinsert(struct net *net,
832 					      struct xfrm_pol_inexact_node *n,
833 					      u16 family)
834 {
835 	unsigned int matched_s, matched_d;
836 	struct hlist_node *newpos = NULL;
837 	struct xfrm_policy *policy, *p;
838 
839 	matched_s = 0;
840 	matched_d = 0;
841 
842 	list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
843 		bool matches_s, matches_d;
844 
845 		if (!policy->bydst_reinsert)
846 			continue;
847 
848 		WARN_ON_ONCE(policy->family != family);
849 
850 		policy->bydst_reinsert = false;
851 		hlist_for_each_entry(p, &n->hhead, bydst) {
852 			if (policy->priority >= p->priority)
853 				newpos = &p->bydst;
854 			else
855 				break;
856 		}
857 
858 		if (newpos)
859 			hlist_add_behind(&policy->bydst, newpos);
860 		else
861 			hlist_add_head(&policy->bydst, &n->hhead);
862 
863 		/* paranoia checks follow.
864 		 * Check that the reinserted policy matches at least
865 		 * saddr or daddr for current node prefix.
866 		 *
867 		 * Matching both is fine, matching saddr in one policy
868 		 * (but not daddr) and then matching only daddr in another
869 		 * is a bug.
870 		 */
871 		matches_s = xfrm_policy_addr_delta(&policy->selector.saddr,
872 						   &n->addr,
873 						   n->prefixlen,
874 						   family) == 0;
875 		matches_d = xfrm_policy_addr_delta(&policy->selector.daddr,
876 						   &n->addr,
877 						   n->prefixlen,
878 						   family) == 0;
879 		if (matches_s && matches_d)
880 			continue;
881 
882 		WARN_ON_ONCE(!matches_s && !matches_d);
883 		if (matches_s)
884 			matched_s++;
885 		if (matches_d)
886 			matched_d++;
887 		WARN_ON_ONCE(matched_s && matched_d);
888 	}
889 }
890 
891 static void xfrm_policy_inexact_node_reinsert(struct net *net,
892 					      struct xfrm_pol_inexact_node *n,
893 					      struct rb_root *new,
894 					      u16 family)
895 {
896 	struct rb_node **p, *parent = NULL;
897 	struct xfrm_pol_inexact_node *node;
898 
899 	/* we should not have another subtree here */
900 	WARN_ON_ONCE(!RB_EMPTY_ROOT(&n->root));
901 
902 	p = &new->rb_node;
903 	while (*p) {
904 		u8 prefixlen;
905 		int delta;
906 
907 		parent = *p;
908 		node = rb_entry(*p, struct xfrm_pol_inexact_node, node);
909 
910 		prefixlen = min(node->prefixlen, n->prefixlen);
911 
912 		delta = xfrm_policy_addr_delta(&n->addr, &node->addr,
913 					       prefixlen, family);
914 		if (delta < 0) {
915 			p = &parent->rb_left;
916 		} else if (delta > 0) {
917 			p = &parent->rb_right;
918 		} else {
919 			struct xfrm_policy *tmp;
920 
921 			hlist_for_each_entry(tmp, &node->hhead, bydst)
922 				tmp->bydst_reinsert = true;
923 			hlist_for_each_entry(tmp, &n->hhead, bydst)
924 				tmp->bydst_reinsert = true;
925 
926 			INIT_HLIST_HEAD(&node->hhead);
927 			xfrm_policy_inexact_list_reinsert(net, node, family);
928 
929 			if (node->prefixlen == n->prefixlen) {
930 				kfree_rcu(n, rcu);
931 				return;
932 			}
933 
934 			rb_erase(*p, new);
935 			kfree_rcu(n, rcu);
936 			n = node;
937 			n->prefixlen = prefixlen;
938 			*p = new->rb_node;
939 			parent = NULL;
940 		}
941 	}
942 
943 	rb_link_node_rcu(&n->node, parent, p);
944 	rb_insert_color(&n->node, new);
945 }
946 
947 /* merge nodes v and n */
948 static void xfrm_policy_inexact_node_merge(struct net *net,
949 					   struct xfrm_pol_inexact_node *v,
950 					   struct xfrm_pol_inexact_node *n,
951 					   u16 family)
952 {
953 	struct xfrm_pol_inexact_node *node;
954 	struct xfrm_policy *tmp;
955 	struct rb_node *rnode;
956 
957 	/* To-be-merged node v has a subtree.
958 	 *
959 	 * Dismantle it and insert its nodes to n->root.
960 	 */
961 	while ((rnode = rb_first(&v->root)) != NULL) {
962 		node = rb_entry(rnode, struct xfrm_pol_inexact_node, node);
963 		rb_erase(&node->node, &v->root);
964 		xfrm_policy_inexact_node_reinsert(net, node, &n->root,
965 						  family);
966 	}
967 
968 	hlist_for_each_entry(tmp, &v->hhead, bydst)
969 		tmp->bydst_reinsert = true;
970 	hlist_for_each_entry(tmp, &n->hhead, bydst)
971 		tmp->bydst_reinsert = true;
972 
973 	INIT_HLIST_HEAD(&n->hhead);
974 	xfrm_policy_inexact_list_reinsert(net, n, family);
975 }
976 
977 static struct xfrm_pol_inexact_node *
978 xfrm_policy_inexact_insert_node(struct net *net,
979 				struct rb_root *root,
980 				xfrm_address_t *addr,
981 				u16 family, u8 prefixlen, u8 dir)
982 {
983 	struct xfrm_pol_inexact_node *cached = NULL;
984 	struct rb_node **p, *parent = NULL;
985 	struct xfrm_pol_inexact_node *node;
986 
987 	p = &root->rb_node;
988 	while (*p) {
989 		int delta;
990 
991 		parent = *p;
992 		node = rb_entry(*p, struct xfrm_pol_inexact_node, node);
993 
994 		delta = xfrm_policy_addr_delta(addr, &node->addr,
995 					       node->prefixlen,
996 					       family);
997 		if (delta == 0 && prefixlen >= node->prefixlen) {
998 			WARN_ON_ONCE(cached); /* ipsec policies got lost */
999 			return node;
1000 		}
1001 
1002 		if (delta < 0)
1003 			p = &parent->rb_left;
1004 		else
1005 			p = &parent->rb_right;
1006 
1007 		if (prefixlen < node->prefixlen) {
1008 			delta = xfrm_policy_addr_delta(addr, &node->addr,
1009 						       prefixlen,
1010 						       family);
1011 			if (delta)
1012 				continue;
1013 
1014 			/* This node is a subnet of the new prefix. It needs
1015 			 * to be removed and re-inserted with the smaller
1016 			 * prefix and all nodes that are now also covered
1017 			 * by the reduced prefixlen.
1018 			 */
1019 			rb_erase(&node->node, root);
1020 
1021 			if (!cached) {
1022 				xfrm_pol_inexact_node_init(node, addr,
1023 							   prefixlen);
1024 				cached = node;
1025 			} else {
1026 				/* This node also falls within the new
1027 				 * prefixlen. Merge the to-be-reinserted
1028 				 * node and this one.
1029 				 */
1030 				xfrm_policy_inexact_node_merge(net, node,
1031 							       cached, family);
1032 				kfree_rcu(node, rcu);
1033 			}
1034 
1035 			/* restart */
1036 			p = &root->rb_node;
1037 			parent = NULL;
1038 		}
1039 	}
1040 
1041 	node = cached;
1042 	if (!node) {
1043 		node = xfrm_pol_inexact_node_alloc(addr, prefixlen);
1044 		if (!node)
1045 			return NULL;
1046 	}
1047 
1048 	rb_link_node_rcu(&node->node, parent, p);
1049 	rb_insert_color(&node->node, root);
1050 
1051 	return node;
1052 }
1053 
1054 static void xfrm_policy_inexact_gc_tree(struct rb_root *r, bool rm)
1055 {
1056 	struct xfrm_pol_inexact_node *node;
1057 	struct rb_node *rn = rb_first(r);
1058 
1059 	while (rn) {
1060 		node = rb_entry(rn, struct xfrm_pol_inexact_node, node);
1061 
1062 		xfrm_policy_inexact_gc_tree(&node->root, rm);
1063 		rn = rb_next(rn);
1064 
1065 		if (!hlist_empty(&node->hhead) || !RB_EMPTY_ROOT(&node->root)) {
1066 			WARN_ON_ONCE(rm);
1067 			continue;
1068 		}
1069 
1070 		rb_erase(&node->node, r);
1071 		kfree_rcu(node, rcu);
1072 	}
1073 }
1074 
1075 static void __xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin *b, bool net_exit)
1076 {
1077 	write_seqcount_begin(&b->count);
1078 	xfrm_policy_inexact_gc_tree(&b->root_d, net_exit);
1079 	xfrm_policy_inexact_gc_tree(&b->root_s, net_exit);
1080 	write_seqcount_end(&b->count);
1081 
1082 	if (!RB_EMPTY_ROOT(&b->root_d) || !RB_EMPTY_ROOT(&b->root_s) ||
1083 	    !hlist_empty(&b->hhead)) {
1084 		WARN_ON_ONCE(net_exit);
1085 		return;
1086 	}
1087 
1088 	if (rhashtable_remove_fast(&xfrm_policy_inexact_table, &b->head,
1089 				   xfrm_pol_inexact_params) == 0) {
1090 		list_del(&b->inexact_bins);
1091 		kfree_rcu(b, rcu);
1092 	}
1093 }
1094 
1095 static void xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin *b)
1096 {
1097 	struct net *net = read_pnet(&b->k.net);
1098 
1099 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1100 	__xfrm_policy_inexact_prune_bin(b, false);
1101 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1102 }
1103 
1104 static void __xfrm_policy_inexact_flush(struct net *net)
1105 {
1106 	struct xfrm_pol_inexact_bin *bin, *t;
1107 
1108 	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1109 
1110 	list_for_each_entry_safe(bin, t, &net->xfrm.inexact_bins, inexact_bins)
1111 		__xfrm_policy_inexact_prune_bin(bin, false);
1112 }
1113 
1114 static struct hlist_head *
1115 xfrm_policy_inexact_alloc_chain(struct xfrm_pol_inexact_bin *bin,
1116 				struct xfrm_policy *policy, u8 dir)
1117 {
1118 	struct xfrm_pol_inexact_node *n;
1119 	struct net *net;
1120 
1121 	net = xp_net(policy);
1122 	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1123 
1124 	if (xfrm_policy_inexact_insert_use_any_list(policy))
1125 		return &bin->hhead;
1126 
1127 	if (xfrm_pol_inexact_addr_use_any_list(&policy->selector.daddr,
1128 					       policy->family,
1129 					       policy->selector.prefixlen_d)) {
1130 		write_seqcount_begin(&bin->count);
1131 		n = xfrm_policy_inexact_insert_node(net,
1132 						    &bin->root_s,
1133 						    &policy->selector.saddr,
1134 						    policy->family,
1135 						    policy->selector.prefixlen_s,
1136 						    dir);
1137 		write_seqcount_end(&bin->count);
1138 		if (!n)
1139 			return NULL;
1140 
1141 		return &n->hhead;
1142 	}
1143 
1144 	/* daddr is fixed */
1145 	write_seqcount_begin(&bin->count);
1146 	n = xfrm_policy_inexact_insert_node(net,
1147 					    &bin->root_d,
1148 					    &policy->selector.daddr,
1149 					    policy->family,
1150 					    policy->selector.prefixlen_d, dir);
1151 	write_seqcount_end(&bin->count);
1152 	if (!n)
1153 		return NULL;
1154 
1155 	/* saddr is wildcard */
1156 	if (xfrm_pol_inexact_addr_use_any_list(&policy->selector.saddr,
1157 					       policy->family,
1158 					       policy->selector.prefixlen_s))
1159 		return &n->hhead;
1160 
1161 	write_seqcount_begin(&bin->count);
1162 	n = xfrm_policy_inexact_insert_node(net,
1163 					    &n->root,
1164 					    &policy->selector.saddr,
1165 					    policy->family,
1166 					    policy->selector.prefixlen_s, dir);
1167 	write_seqcount_end(&bin->count);
1168 	if (!n)
1169 		return NULL;
1170 
1171 	return &n->hhead;
1172 }
1173 
1174 static struct xfrm_policy *
1175 xfrm_policy_inexact_insert(struct xfrm_policy *policy, u8 dir, int excl)
1176 {
1177 	struct xfrm_pol_inexact_bin *bin;
1178 	struct xfrm_policy *delpol;
1179 	struct hlist_head *chain;
1180 	struct net *net;
1181 
1182 	bin = xfrm_policy_inexact_alloc_bin(policy, dir);
1183 	if (!bin)
1184 		return ERR_PTR(-ENOMEM);
1185 
1186 	net = xp_net(policy);
1187 	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1188 
1189 	chain = xfrm_policy_inexact_alloc_chain(bin, policy, dir);
1190 	if (!chain) {
1191 		__xfrm_policy_inexact_prune_bin(bin, false);
1192 		return ERR_PTR(-ENOMEM);
1193 	}
1194 
1195 	delpol = xfrm_policy_insert_list(chain, policy, excl);
1196 	if (delpol && excl) {
1197 		__xfrm_policy_inexact_prune_bin(bin, false);
1198 		return ERR_PTR(-EEXIST);
1199 	}
1200 
1201 	chain = &net->xfrm.policy_inexact[dir];
1202 	xfrm_policy_insert_inexact_list(chain, policy);
1203 
1204 	if (delpol)
1205 		__xfrm_policy_inexact_prune_bin(bin, false);
1206 
1207 	return delpol;
1208 }
1209 
1210 static void xfrm_hash_rebuild(struct work_struct *work)
1211 {
1212 	struct net *net = container_of(work, struct net,
1213 				       xfrm.policy_hthresh.work);
1214 	unsigned int hmask;
1215 	struct xfrm_policy *pol;
1216 	struct xfrm_policy *policy;
1217 	struct hlist_head *chain;
1218 	struct hlist_head *odst;
1219 	struct hlist_node *newpos;
1220 	int i;
1221 	int dir;
1222 	unsigned seq;
1223 	u8 lbits4, rbits4, lbits6, rbits6;
1224 
1225 	mutex_lock(&hash_resize_mutex);
1226 
1227 	/* read selector prefixlen thresholds */
1228 	do {
1229 		seq = read_seqbegin(&net->xfrm.policy_hthresh.lock);
1230 
1231 		lbits4 = net->xfrm.policy_hthresh.lbits4;
1232 		rbits4 = net->xfrm.policy_hthresh.rbits4;
1233 		lbits6 = net->xfrm.policy_hthresh.lbits6;
1234 		rbits6 = net->xfrm.policy_hthresh.rbits6;
1235 	} while (read_seqretry(&net->xfrm.policy_hthresh.lock, seq));
1236 
1237 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1238 
1239 	/* make sure that we can insert the indirect policies again before
1240 	 * we start with destructive action.
1241 	 */
1242 	list_for_each_entry(policy, &net->xfrm.policy_all, walk.all) {
1243 		struct xfrm_pol_inexact_bin *bin;
1244 		u8 dbits, sbits;
1245 
1246 		dir = xfrm_policy_id2dir(policy->index);
1247 		if (policy->walk.dead || dir >= XFRM_POLICY_MAX)
1248 			continue;
1249 
1250 		if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
1251 			if (policy->family == AF_INET) {
1252 				dbits = rbits4;
1253 				sbits = lbits4;
1254 			} else {
1255 				dbits = rbits6;
1256 				sbits = lbits6;
1257 			}
1258 		} else {
1259 			if (policy->family == AF_INET) {
1260 				dbits = lbits4;
1261 				sbits = rbits4;
1262 			} else {
1263 				dbits = lbits6;
1264 				sbits = rbits6;
1265 			}
1266 		}
1267 
1268 		if (policy->selector.prefixlen_d < dbits ||
1269 		    policy->selector.prefixlen_s < sbits)
1270 			continue;
1271 
1272 		bin = xfrm_policy_inexact_alloc_bin(policy, dir);
1273 		if (!bin)
1274 			goto out_unlock;
1275 
1276 		if (!xfrm_policy_inexact_alloc_chain(bin, policy, dir))
1277 			goto out_unlock;
1278 	}
1279 
1280 	/* reset the bydst and inexact table in all directions */
1281 	xfrm_hash_reset_inexact_table(net);
1282 
1283 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
1284 		INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
1285 		hmask = net->xfrm.policy_bydst[dir].hmask;
1286 		odst = net->xfrm.policy_bydst[dir].table;
1287 		for (i = hmask; i >= 0; i--)
1288 			INIT_HLIST_HEAD(odst + i);
1289 		if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
1290 			/* dir out => dst = remote, src = local */
1291 			net->xfrm.policy_bydst[dir].dbits4 = rbits4;
1292 			net->xfrm.policy_bydst[dir].sbits4 = lbits4;
1293 			net->xfrm.policy_bydst[dir].dbits6 = rbits6;
1294 			net->xfrm.policy_bydst[dir].sbits6 = lbits6;
1295 		} else {
1296 			/* dir in/fwd => dst = local, src = remote */
1297 			net->xfrm.policy_bydst[dir].dbits4 = lbits4;
1298 			net->xfrm.policy_bydst[dir].sbits4 = rbits4;
1299 			net->xfrm.policy_bydst[dir].dbits6 = lbits6;
1300 			net->xfrm.policy_bydst[dir].sbits6 = rbits6;
1301 		}
1302 	}
1303 
1304 	/* re-insert all policies by order of creation */
1305 	list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
1306 		if (policy->walk.dead)
1307 			continue;
1308 		dir = xfrm_policy_id2dir(policy->index);
1309 		if (dir >= XFRM_POLICY_MAX) {
1310 			/* skip socket policies */
1311 			continue;
1312 		}
1313 		newpos = NULL;
1314 		chain = policy_hash_bysel(net, &policy->selector,
1315 					  policy->family, dir);
1316 		if (!chain) {
1317 			void *p = xfrm_policy_inexact_insert(policy, dir, 0);
1318 
1319 			WARN_ONCE(IS_ERR(p), "reinsert: %ld\n", PTR_ERR(p));
1320 			continue;
1321 		}
1322 
1323 		hlist_for_each_entry(pol, chain, bydst) {
1324 			if (policy->priority >= pol->priority)
1325 				newpos = &pol->bydst;
1326 			else
1327 				break;
1328 		}
1329 		if (newpos)
1330 			hlist_add_behind_rcu(&policy->bydst, newpos);
1331 		else
1332 			hlist_add_head_rcu(&policy->bydst, chain);
1333 	}
1334 
1335 out_unlock:
1336 	__xfrm_policy_inexact_flush(net);
1337 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1338 
1339 	mutex_unlock(&hash_resize_mutex);
1340 }
1341 
1342 void xfrm_policy_hash_rebuild(struct net *net)
1343 {
1344 	schedule_work(&net->xfrm.policy_hthresh.work);
1345 }
1346 EXPORT_SYMBOL(xfrm_policy_hash_rebuild);
1347 
1348 /* Generate new index... KAME seems to generate them ordered by cost
1349  * of an absolute inpredictability of ordering of rules. This will not pass. */
1350 static u32 xfrm_gen_index(struct net *net, int dir, u32 index)
1351 {
1352 	static u32 idx_generator;
1353 
1354 	for (;;) {
1355 		struct hlist_head *list;
1356 		struct xfrm_policy *p;
1357 		u32 idx;
1358 		int found;
1359 
1360 		if (!index) {
1361 			idx = (idx_generator | dir);
1362 			idx_generator += 8;
1363 		} else {
1364 			idx = index;
1365 			index = 0;
1366 		}
1367 
1368 		if (idx == 0)
1369 			idx = 8;
1370 		list = net->xfrm.policy_byidx + idx_hash(net, idx);
1371 		found = 0;
1372 		hlist_for_each_entry(p, list, byidx) {
1373 			if (p->index == idx) {
1374 				found = 1;
1375 				break;
1376 			}
1377 		}
1378 		if (!found)
1379 			return idx;
1380 	}
1381 }
1382 
1383 static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
1384 {
1385 	u32 *p1 = (u32 *) s1;
1386 	u32 *p2 = (u32 *) s2;
1387 	int len = sizeof(struct xfrm_selector) / sizeof(u32);
1388 	int i;
1389 
1390 	for (i = 0; i < len; i++) {
1391 		if (p1[i] != p2[i])
1392 			return 1;
1393 	}
1394 
1395 	return 0;
1396 }
1397 
1398 static void xfrm_policy_requeue(struct xfrm_policy *old,
1399 				struct xfrm_policy *new)
1400 {
1401 	struct xfrm_policy_queue *pq = &old->polq;
1402 	struct sk_buff_head list;
1403 
1404 	if (skb_queue_empty(&pq->hold_queue))
1405 		return;
1406 
1407 	__skb_queue_head_init(&list);
1408 
1409 	spin_lock_bh(&pq->hold_queue.lock);
1410 	skb_queue_splice_init(&pq->hold_queue, &list);
1411 	if (del_timer(&pq->hold_timer))
1412 		xfrm_pol_put(old);
1413 	spin_unlock_bh(&pq->hold_queue.lock);
1414 
1415 	pq = &new->polq;
1416 
1417 	spin_lock_bh(&pq->hold_queue.lock);
1418 	skb_queue_splice(&list, &pq->hold_queue);
1419 	pq->timeout = XFRM_QUEUE_TMO_MIN;
1420 	if (!mod_timer(&pq->hold_timer, jiffies))
1421 		xfrm_pol_hold(new);
1422 	spin_unlock_bh(&pq->hold_queue.lock);
1423 }
1424 
1425 static bool xfrm_policy_mark_match(struct xfrm_policy *policy,
1426 				   struct xfrm_policy *pol)
1427 {
1428 	u32 mark = policy->mark.v & policy->mark.m;
1429 
1430 	if (policy->mark.v == pol->mark.v && policy->mark.m == pol->mark.m)
1431 		return true;
1432 
1433 	if ((mark & pol->mark.m) == pol->mark.v &&
1434 	    policy->priority == pol->priority)
1435 		return true;
1436 
1437 	return false;
1438 }
1439 
1440 static u32 xfrm_pol_bin_key(const void *data, u32 len, u32 seed)
1441 {
1442 	const struct xfrm_pol_inexact_key *k = data;
1443 	u32 a = k->type << 24 | k->dir << 16 | k->family;
1444 
1445 	return jhash_3words(a, k->if_id, net_hash_mix(read_pnet(&k->net)),
1446 			    seed);
1447 }
1448 
1449 static u32 xfrm_pol_bin_obj(const void *data, u32 len, u32 seed)
1450 {
1451 	const struct xfrm_pol_inexact_bin *b = data;
1452 
1453 	return xfrm_pol_bin_key(&b->k, 0, seed);
1454 }
1455 
1456 static int xfrm_pol_bin_cmp(struct rhashtable_compare_arg *arg,
1457 			    const void *ptr)
1458 {
1459 	const struct xfrm_pol_inexact_key *key = arg->key;
1460 	const struct xfrm_pol_inexact_bin *b = ptr;
1461 	int ret;
1462 
1463 	if (!net_eq(read_pnet(&b->k.net), read_pnet(&key->net)))
1464 		return -1;
1465 
1466 	ret = b->k.dir ^ key->dir;
1467 	if (ret)
1468 		return ret;
1469 
1470 	ret = b->k.type ^ key->type;
1471 	if (ret)
1472 		return ret;
1473 
1474 	ret = b->k.family ^ key->family;
1475 	if (ret)
1476 		return ret;
1477 
1478 	return b->k.if_id ^ key->if_id;
1479 }
1480 
1481 static const struct rhashtable_params xfrm_pol_inexact_params = {
1482 	.head_offset		= offsetof(struct xfrm_pol_inexact_bin, head),
1483 	.hashfn			= xfrm_pol_bin_key,
1484 	.obj_hashfn		= xfrm_pol_bin_obj,
1485 	.obj_cmpfn		= xfrm_pol_bin_cmp,
1486 	.automatic_shrinking	= true,
1487 };
1488 
1489 static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
1490 					    struct xfrm_policy *policy)
1491 {
1492 	struct xfrm_policy *pol, *delpol = NULL;
1493 	struct hlist_node *newpos = NULL;
1494 	int i = 0;
1495 
1496 	hlist_for_each_entry(pol, chain, bydst_inexact_list) {
1497 		if (pol->type == policy->type &&
1498 		    pol->if_id == policy->if_id &&
1499 		    !selector_cmp(&pol->selector, &policy->selector) &&
1500 		    xfrm_policy_mark_match(policy, pol) &&
1501 		    xfrm_sec_ctx_match(pol->security, policy->security) &&
1502 		    !WARN_ON(delpol)) {
1503 			delpol = pol;
1504 			if (policy->priority > pol->priority)
1505 				continue;
1506 		} else if (policy->priority >= pol->priority) {
1507 			newpos = &pol->bydst_inexact_list;
1508 			continue;
1509 		}
1510 		if (delpol)
1511 			break;
1512 	}
1513 
1514 	if (newpos)
1515 		hlist_add_behind_rcu(&policy->bydst_inexact_list, newpos);
1516 	else
1517 		hlist_add_head_rcu(&policy->bydst_inexact_list, chain);
1518 
1519 	hlist_for_each_entry(pol, chain, bydst_inexact_list) {
1520 		pol->pos = i;
1521 		i++;
1522 	}
1523 }
1524 
1525 static struct xfrm_policy *xfrm_policy_insert_list(struct hlist_head *chain,
1526 						   struct xfrm_policy *policy,
1527 						   bool excl)
1528 {
1529 	struct xfrm_policy *pol, *newpos = NULL, *delpol = NULL;
1530 
1531 	hlist_for_each_entry(pol, chain, bydst) {
1532 		if (pol->type == policy->type &&
1533 		    pol->if_id == policy->if_id &&
1534 		    !selector_cmp(&pol->selector, &policy->selector) &&
1535 		    xfrm_policy_mark_match(policy, pol) &&
1536 		    xfrm_sec_ctx_match(pol->security, policy->security) &&
1537 		    !WARN_ON(delpol)) {
1538 			if (excl)
1539 				return ERR_PTR(-EEXIST);
1540 			delpol = pol;
1541 			if (policy->priority > pol->priority)
1542 				continue;
1543 		} else if (policy->priority >= pol->priority) {
1544 			newpos = pol;
1545 			continue;
1546 		}
1547 		if (delpol)
1548 			break;
1549 	}
1550 
1551 	if (newpos)
1552 		hlist_add_behind_rcu(&policy->bydst, &newpos->bydst);
1553 	else
1554 		hlist_add_head_rcu(&policy->bydst, chain);
1555 
1556 	return delpol;
1557 }
1558 
1559 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
1560 {
1561 	struct net *net = xp_net(policy);
1562 	struct xfrm_policy *delpol;
1563 	struct hlist_head *chain;
1564 
1565 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1566 	chain = policy_hash_bysel(net, &policy->selector, policy->family, dir);
1567 	if (chain)
1568 		delpol = xfrm_policy_insert_list(chain, policy, excl);
1569 	else
1570 		delpol = xfrm_policy_inexact_insert(policy, dir, excl);
1571 
1572 	if (IS_ERR(delpol)) {
1573 		spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1574 		return PTR_ERR(delpol);
1575 	}
1576 
1577 	__xfrm_policy_link(policy, dir);
1578 
1579 	/* After previous checking, family can either be AF_INET or AF_INET6 */
1580 	if (policy->family == AF_INET)
1581 		rt_genid_bump_ipv4(net);
1582 	else
1583 		rt_genid_bump_ipv6(net);
1584 
1585 	if (delpol) {
1586 		xfrm_policy_requeue(delpol, policy);
1587 		__xfrm_policy_unlink(delpol, dir);
1588 	}
1589 	policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir, policy->index);
1590 	hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
1591 	policy->curlft.add_time = ktime_get_real_seconds();
1592 	policy->curlft.use_time = 0;
1593 	if (!mod_timer(&policy->timer, jiffies + HZ))
1594 		xfrm_pol_hold(policy);
1595 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1596 
1597 	if (delpol)
1598 		xfrm_policy_kill(delpol);
1599 	else if (xfrm_bydst_should_resize(net, dir, NULL))
1600 		schedule_work(&net->xfrm.policy_hash_work);
1601 
1602 	return 0;
1603 }
1604 EXPORT_SYMBOL(xfrm_policy_insert);
1605 
1606 static struct xfrm_policy *
1607 __xfrm_policy_bysel_ctx(struct hlist_head *chain, u32 mark, u32 if_id,
1608 			u8 type, int dir,
1609 			struct xfrm_selector *sel,
1610 			struct xfrm_sec_ctx *ctx)
1611 {
1612 	struct xfrm_policy *pol;
1613 
1614 	if (!chain)
1615 		return NULL;
1616 
1617 	hlist_for_each_entry(pol, chain, bydst) {
1618 		if (pol->type == type &&
1619 		    pol->if_id == if_id &&
1620 		    (mark & pol->mark.m) == pol->mark.v &&
1621 		    !selector_cmp(sel, &pol->selector) &&
1622 		    xfrm_sec_ctx_match(ctx, pol->security))
1623 			return pol;
1624 	}
1625 
1626 	return NULL;
1627 }
1628 
1629 struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u32 if_id,
1630 					  u8 type, int dir,
1631 					  struct xfrm_selector *sel,
1632 					  struct xfrm_sec_ctx *ctx, int delete,
1633 					  int *err)
1634 {
1635 	struct xfrm_pol_inexact_bin *bin = NULL;
1636 	struct xfrm_policy *pol, *ret = NULL;
1637 	struct hlist_head *chain;
1638 
1639 	*err = 0;
1640 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1641 	chain = policy_hash_bysel(net, sel, sel->family, dir);
1642 	if (!chain) {
1643 		struct xfrm_pol_inexact_candidates cand;
1644 		int i;
1645 
1646 		bin = xfrm_policy_inexact_lookup(net, type,
1647 						 sel->family, dir, if_id);
1648 		if (!bin) {
1649 			spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1650 			return NULL;
1651 		}
1652 
1653 		if (!xfrm_policy_find_inexact_candidates(&cand, bin,
1654 							 &sel->saddr,
1655 							 &sel->daddr)) {
1656 			spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1657 			return NULL;
1658 		}
1659 
1660 		pol = NULL;
1661 		for (i = 0; i < ARRAY_SIZE(cand.res); i++) {
1662 			struct xfrm_policy *tmp;
1663 
1664 			tmp = __xfrm_policy_bysel_ctx(cand.res[i], mark,
1665 						      if_id, type, dir,
1666 						      sel, ctx);
1667 			if (!tmp)
1668 				continue;
1669 
1670 			if (!pol || tmp->pos < pol->pos)
1671 				pol = tmp;
1672 		}
1673 	} else {
1674 		pol = __xfrm_policy_bysel_ctx(chain, mark, if_id, type, dir,
1675 					      sel, ctx);
1676 	}
1677 
1678 	if (pol) {
1679 		xfrm_pol_hold(pol);
1680 		if (delete) {
1681 			*err = security_xfrm_policy_delete(pol->security);
1682 			if (*err) {
1683 				spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1684 				return pol;
1685 			}
1686 			__xfrm_policy_unlink(pol, dir);
1687 		}
1688 		ret = pol;
1689 	}
1690 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1691 
1692 	if (ret && delete)
1693 		xfrm_policy_kill(ret);
1694 	if (bin && delete)
1695 		xfrm_policy_inexact_prune_bin(bin);
1696 	return ret;
1697 }
1698 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
1699 
1700 struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u32 if_id,
1701 				     u8 type, int dir, u32 id, int delete,
1702 				     int *err)
1703 {
1704 	struct xfrm_policy *pol, *ret;
1705 	struct hlist_head *chain;
1706 
1707 	*err = -ENOENT;
1708 	if (xfrm_policy_id2dir(id) != dir)
1709 		return NULL;
1710 
1711 	*err = 0;
1712 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1713 	chain = net->xfrm.policy_byidx + idx_hash(net, id);
1714 	ret = NULL;
1715 	hlist_for_each_entry(pol, chain, byidx) {
1716 		if (pol->type == type && pol->index == id &&
1717 		    pol->if_id == if_id &&
1718 		    (mark & pol->mark.m) == pol->mark.v) {
1719 			xfrm_pol_hold(pol);
1720 			if (delete) {
1721 				*err = security_xfrm_policy_delete(
1722 								pol->security);
1723 				if (*err) {
1724 					spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1725 					return pol;
1726 				}
1727 				__xfrm_policy_unlink(pol, dir);
1728 			}
1729 			ret = pol;
1730 			break;
1731 		}
1732 	}
1733 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1734 
1735 	if (ret && delete)
1736 		xfrm_policy_kill(ret);
1737 	return ret;
1738 }
1739 EXPORT_SYMBOL(xfrm_policy_byid);
1740 
1741 #ifdef CONFIG_SECURITY_NETWORK_XFRM
1742 static inline int
1743 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
1744 {
1745 	struct xfrm_policy *pol;
1746 	int err = 0;
1747 
1748 	list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
1749 		if (pol->walk.dead ||
1750 		    xfrm_policy_id2dir(pol->index) >= XFRM_POLICY_MAX ||
1751 		    pol->type != type)
1752 			continue;
1753 
1754 		err = security_xfrm_policy_delete(pol->security);
1755 		if (err) {
1756 			xfrm_audit_policy_delete(pol, 0, task_valid);
1757 			return err;
1758 		}
1759 	}
1760 	return err;
1761 }
1762 #else
1763 static inline int
1764 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
1765 {
1766 	return 0;
1767 }
1768 #endif
1769 
1770 int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
1771 {
1772 	int dir, err = 0, cnt = 0;
1773 	struct xfrm_policy *pol;
1774 
1775 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1776 
1777 	err = xfrm_policy_flush_secctx_check(net, type, task_valid);
1778 	if (err)
1779 		goto out;
1780 
1781 again:
1782 	list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
1783 		dir = xfrm_policy_id2dir(pol->index);
1784 		if (pol->walk.dead ||
1785 		    dir >= XFRM_POLICY_MAX ||
1786 		    pol->type != type)
1787 			continue;
1788 
1789 		__xfrm_policy_unlink(pol, dir);
1790 		spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1791 		cnt++;
1792 		xfrm_audit_policy_delete(pol, 1, task_valid);
1793 		xfrm_policy_kill(pol);
1794 		spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1795 		goto again;
1796 	}
1797 	if (cnt)
1798 		__xfrm_policy_inexact_flush(net);
1799 	else
1800 		err = -ESRCH;
1801 out:
1802 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1803 	return err;
1804 }
1805 EXPORT_SYMBOL(xfrm_policy_flush);
1806 
1807 int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
1808 		     int (*func)(struct xfrm_policy *, int, int, void*),
1809 		     void *data)
1810 {
1811 	struct xfrm_policy *pol;
1812 	struct xfrm_policy_walk_entry *x;
1813 	int error = 0;
1814 
1815 	if (walk->type >= XFRM_POLICY_TYPE_MAX &&
1816 	    walk->type != XFRM_POLICY_TYPE_ANY)
1817 		return -EINVAL;
1818 
1819 	if (list_empty(&walk->walk.all) && walk->seq != 0)
1820 		return 0;
1821 
1822 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1823 	if (list_empty(&walk->walk.all))
1824 		x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
1825 	else
1826 		x = list_first_entry(&walk->walk.all,
1827 				     struct xfrm_policy_walk_entry, all);
1828 
1829 	list_for_each_entry_from(x, &net->xfrm.policy_all, all) {
1830 		if (x->dead)
1831 			continue;
1832 		pol = container_of(x, struct xfrm_policy, walk);
1833 		if (walk->type != XFRM_POLICY_TYPE_ANY &&
1834 		    walk->type != pol->type)
1835 			continue;
1836 		error = func(pol, xfrm_policy_id2dir(pol->index),
1837 			     walk->seq, data);
1838 		if (error) {
1839 			list_move_tail(&walk->walk.all, &x->all);
1840 			goto out;
1841 		}
1842 		walk->seq++;
1843 	}
1844 	if (walk->seq == 0) {
1845 		error = -ENOENT;
1846 		goto out;
1847 	}
1848 	list_del_init(&walk->walk.all);
1849 out:
1850 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1851 	return error;
1852 }
1853 EXPORT_SYMBOL(xfrm_policy_walk);
1854 
1855 void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type)
1856 {
1857 	INIT_LIST_HEAD(&walk->walk.all);
1858 	walk->walk.dead = 1;
1859 	walk->type = type;
1860 	walk->seq = 0;
1861 }
1862 EXPORT_SYMBOL(xfrm_policy_walk_init);
1863 
1864 void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net)
1865 {
1866 	if (list_empty(&walk->walk.all))
1867 		return;
1868 
1869 	spin_lock_bh(&net->xfrm.xfrm_policy_lock); /*FIXME where is net? */
1870 	list_del(&walk->walk.all);
1871 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1872 }
1873 EXPORT_SYMBOL(xfrm_policy_walk_done);
1874 
1875 /*
1876  * Find policy to apply to this flow.
1877  *
1878  * Returns 0 if policy found, else an -errno.
1879  */
1880 static int xfrm_policy_match(const struct xfrm_policy *pol,
1881 			     const struct flowi *fl,
1882 			     u8 type, u16 family, int dir, u32 if_id)
1883 {
1884 	const struct xfrm_selector *sel = &pol->selector;
1885 	int ret = -ESRCH;
1886 	bool match;
1887 
1888 	if (pol->family != family ||
1889 	    pol->if_id != if_id ||
1890 	    (fl->flowi_mark & pol->mark.m) != pol->mark.v ||
1891 	    pol->type != type)
1892 		return ret;
1893 
1894 	match = xfrm_selector_match(sel, fl, family);
1895 	if (match)
1896 		ret = security_xfrm_policy_lookup(pol->security, fl->flowi_secid,
1897 						  dir);
1898 	return ret;
1899 }
1900 
1901 static struct xfrm_pol_inexact_node *
1902 xfrm_policy_lookup_inexact_addr(const struct rb_root *r,
1903 				seqcount_t *count,
1904 				const xfrm_address_t *addr, u16 family)
1905 {
1906 	const struct rb_node *parent;
1907 	int seq;
1908 
1909 again:
1910 	seq = read_seqcount_begin(count);
1911 
1912 	parent = rcu_dereference_raw(r->rb_node);
1913 	while (parent) {
1914 		struct xfrm_pol_inexact_node *node;
1915 		int delta;
1916 
1917 		node = rb_entry(parent, struct xfrm_pol_inexact_node, node);
1918 
1919 		delta = xfrm_policy_addr_delta(addr, &node->addr,
1920 					       node->prefixlen, family);
1921 		if (delta < 0) {
1922 			parent = rcu_dereference_raw(parent->rb_left);
1923 			continue;
1924 		} else if (delta > 0) {
1925 			parent = rcu_dereference_raw(parent->rb_right);
1926 			continue;
1927 		}
1928 
1929 		return node;
1930 	}
1931 
1932 	if (read_seqcount_retry(count, seq))
1933 		goto again;
1934 
1935 	return NULL;
1936 }
1937 
1938 static bool
1939 xfrm_policy_find_inexact_candidates(struct xfrm_pol_inexact_candidates *cand,
1940 				    struct xfrm_pol_inexact_bin *b,
1941 				    const xfrm_address_t *saddr,
1942 				    const xfrm_address_t *daddr)
1943 {
1944 	struct xfrm_pol_inexact_node *n;
1945 	u16 family;
1946 
1947 	if (!b)
1948 		return false;
1949 
1950 	family = b->k.family;
1951 	memset(cand, 0, sizeof(*cand));
1952 	cand->res[XFRM_POL_CAND_ANY] = &b->hhead;
1953 
1954 	n = xfrm_policy_lookup_inexact_addr(&b->root_d, &b->count, daddr,
1955 					    family);
1956 	if (n) {
1957 		cand->res[XFRM_POL_CAND_DADDR] = &n->hhead;
1958 		n = xfrm_policy_lookup_inexact_addr(&n->root, &b->count, saddr,
1959 						    family);
1960 		if (n)
1961 			cand->res[XFRM_POL_CAND_BOTH] = &n->hhead;
1962 	}
1963 
1964 	n = xfrm_policy_lookup_inexact_addr(&b->root_s, &b->count, saddr,
1965 					    family);
1966 	if (n)
1967 		cand->res[XFRM_POL_CAND_SADDR] = &n->hhead;
1968 
1969 	return true;
1970 }
1971 
1972 static struct xfrm_pol_inexact_bin *
1973 xfrm_policy_inexact_lookup_rcu(struct net *net, u8 type, u16 family,
1974 			       u8 dir, u32 if_id)
1975 {
1976 	struct xfrm_pol_inexact_key k = {
1977 		.family = family,
1978 		.type = type,
1979 		.dir = dir,
1980 		.if_id = if_id,
1981 	};
1982 
1983 	write_pnet(&k.net, net);
1984 
1985 	return rhashtable_lookup(&xfrm_policy_inexact_table, &k,
1986 				 xfrm_pol_inexact_params);
1987 }
1988 
1989 static struct xfrm_pol_inexact_bin *
1990 xfrm_policy_inexact_lookup(struct net *net, u8 type, u16 family,
1991 			   u8 dir, u32 if_id)
1992 {
1993 	struct xfrm_pol_inexact_bin *bin;
1994 
1995 	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1996 
1997 	rcu_read_lock();
1998 	bin = xfrm_policy_inexact_lookup_rcu(net, type, family, dir, if_id);
1999 	rcu_read_unlock();
2000 
2001 	return bin;
2002 }
2003 
2004 static struct xfrm_policy *
2005 __xfrm_policy_eval_candidates(struct hlist_head *chain,
2006 			      struct xfrm_policy *prefer,
2007 			      const struct flowi *fl,
2008 			      u8 type, u16 family, int dir, u32 if_id)
2009 {
2010 	u32 priority = prefer ? prefer->priority : ~0u;
2011 	struct xfrm_policy *pol;
2012 
2013 	if (!chain)
2014 		return NULL;
2015 
2016 	hlist_for_each_entry_rcu(pol, chain, bydst) {
2017 		int err;
2018 
2019 		if (pol->priority > priority)
2020 			break;
2021 
2022 		err = xfrm_policy_match(pol, fl, type, family, dir, if_id);
2023 		if (err) {
2024 			if (err != -ESRCH)
2025 				return ERR_PTR(err);
2026 
2027 			continue;
2028 		}
2029 
2030 		if (prefer) {
2031 			/* matches.  Is it older than *prefer? */
2032 			if (pol->priority == priority &&
2033 			    prefer->pos < pol->pos)
2034 				return prefer;
2035 		}
2036 
2037 		return pol;
2038 	}
2039 
2040 	return NULL;
2041 }
2042 
2043 static struct xfrm_policy *
2044 xfrm_policy_eval_candidates(struct xfrm_pol_inexact_candidates *cand,
2045 			    struct xfrm_policy *prefer,
2046 			    const struct flowi *fl,
2047 			    u8 type, u16 family, int dir, u32 if_id)
2048 {
2049 	struct xfrm_policy *tmp;
2050 	int i;
2051 
2052 	for (i = 0; i < ARRAY_SIZE(cand->res); i++) {
2053 		tmp = __xfrm_policy_eval_candidates(cand->res[i],
2054 						    prefer,
2055 						    fl, type, family, dir,
2056 						    if_id);
2057 		if (!tmp)
2058 			continue;
2059 
2060 		if (IS_ERR(tmp))
2061 			return tmp;
2062 		prefer = tmp;
2063 	}
2064 
2065 	return prefer;
2066 }
2067 
2068 static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
2069 						     const struct flowi *fl,
2070 						     u16 family, u8 dir,
2071 						     u32 if_id)
2072 {
2073 	struct xfrm_pol_inexact_candidates cand;
2074 	const xfrm_address_t *daddr, *saddr;
2075 	struct xfrm_pol_inexact_bin *bin;
2076 	struct xfrm_policy *pol, *ret;
2077 	struct hlist_head *chain;
2078 	unsigned int sequence;
2079 	int err;
2080 
2081 	daddr = xfrm_flowi_daddr(fl, family);
2082 	saddr = xfrm_flowi_saddr(fl, family);
2083 	if (unlikely(!daddr || !saddr))
2084 		return NULL;
2085 
2086 	rcu_read_lock();
2087  retry:
2088 	do {
2089 		sequence = read_seqcount_begin(&xfrm_policy_hash_generation);
2090 		chain = policy_hash_direct(net, daddr, saddr, family, dir);
2091 	} while (read_seqcount_retry(&xfrm_policy_hash_generation, sequence));
2092 
2093 	ret = NULL;
2094 	hlist_for_each_entry_rcu(pol, chain, bydst) {
2095 		err = xfrm_policy_match(pol, fl, type, family, dir, if_id);
2096 		if (err) {
2097 			if (err == -ESRCH)
2098 				continue;
2099 			else {
2100 				ret = ERR_PTR(err);
2101 				goto fail;
2102 			}
2103 		} else {
2104 			ret = pol;
2105 			break;
2106 		}
2107 	}
2108 	bin = xfrm_policy_inexact_lookup_rcu(net, type, family, dir, if_id);
2109 	if (!bin || !xfrm_policy_find_inexact_candidates(&cand, bin, saddr,
2110 							 daddr))
2111 		goto skip_inexact;
2112 
2113 	pol = xfrm_policy_eval_candidates(&cand, ret, fl, type,
2114 					  family, dir, if_id);
2115 	if (pol) {
2116 		ret = pol;
2117 		if (IS_ERR(pol))
2118 			goto fail;
2119 	}
2120 
2121 skip_inexact:
2122 	if (read_seqcount_retry(&xfrm_policy_hash_generation, sequence))
2123 		goto retry;
2124 
2125 	if (ret && !xfrm_pol_hold_rcu(ret))
2126 		goto retry;
2127 fail:
2128 	rcu_read_unlock();
2129 
2130 	return ret;
2131 }
2132 
2133 static struct xfrm_policy *xfrm_policy_lookup(struct net *net,
2134 					      const struct flowi *fl,
2135 					      u16 family, u8 dir, u32 if_id)
2136 {
2137 #ifdef CONFIG_XFRM_SUB_POLICY
2138 	struct xfrm_policy *pol;
2139 
2140 	pol = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_SUB, fl, family,
2141 					dir, if_id);
2142 	if (pol != NULL)
2143 		return pol;
2144 #endif
2145 	return xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, fl, family,
2146 					 dir, if_id);
2147 }
2148 
2149 static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir,
2150 						 const struct flowi *fl,
2151 						 u16 family, u32 if_id)
2152 {
2153 	struct xfrm_policy *pol;
2154 
2155 	rcu_read_lock();
2156  again:
2157 	pol = rcu_dereference(sk->sk_policy[dir]);
2158 	if (pol != NULL) {
2159 		bool match;
2160 		int err = 0;
2161 
2162 		if (pol->family != family) {
2163 			pol = NULL;
2164 			goto out;
2165 		}
2166 
2167 		match = xfrm_selector_match(&pol->selector, fl, family);
2168 		if (match) {
2169 			if ((sk->sk_mark & pol->mark.m) != pol->mark.v ||
2170 			    pol->if_id != if_id) {
2171 				pol = NULL;
2172 				goto out;
2173 			}
2174 			err = security_xfrm_policy_lookup(pol->security,
2175 						      fl->flowi_secid,
2176 						      dir);
2177 			if (!err) {
2178 				if (!xfrm_pol_hold_rcu(pol))
2179 					goto again;
2180 			} else if (err == -ESRCH) {
2181 				pol = NULL;
2182 			} else {
2183 				pol = ERR_PTR(err);
2184 			}
2185 		} else
2186 			pol = NULL;
2187 	}
2188 out:
2189 	rcu_read_unlock();
2190 	return pol;
2191 }
2192 
2193 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
2194 {
2195 	struct net *net = xp_net(pol);
2196 
2197 	list_add(&pol->walk.all, &net->xfrm.policy_all);
2198 	net->xfrm.policy_count[dir]++;
2199 	xfrm_pol_hold(pol);
2200 }
2201 
2202 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
2203 						int dir)
2204 {
2205 	struct net *net = xp_net(pol);
2206 
2207 	if (list_empty(&pol->walk.all))
2208 		return NULL;
2209 
2210 	/* Socket policies are not hashed. */
2211 	if (!hlist_unhashed(&pol->bydst)) {
2212 		hlist_del_rcu(&pol->bydst);
2213 		hlist_del_init(&pol->bydst_inexact_list);
2214 		hlist_del(&pol->byidx);
2215 	}
2216 
2217 	list_del_init(&pol->walk.all);
2218 	net->xfrm.policy_count[dir]--;
2219 
2220 	return pol;
2221 }
2222 
2223 static void xfrm_sk_policy_link(struct xfrm_policy *pol, int dir)
2224 {
2225 	__xfrm_policy_link(pol, XFRM_POLICY_MAX + dir);
2226 }
2227 
2228 static void xfrm_sk_policy_unlink(struct xfrm_policy *pol, int dir)
2229 {
2230 	__xfrm_policy_unlink(pol, XFRM_POLICY_MAX + dir);
2231 }
2232 
2233 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
2234 {
2235 	struct net *net = xp_net(pol);
2236 
2237 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2238 	pol = __xfrm_policy_unlink(pol, dir);
2239 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2240 	if (pol) {
2241 		xfrm_policy_kill(pol);
2242 		return 0;
2243 	}
2244 	return -ENOENT;
2245 }
2246 EXPORT_SYMBOL(xfrm_policy_delete);
2247 
2248 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
2249 {
2250 	struct net *net = sock_net(sk);
2251 	struct xfrm_policy *old_pol;
2252 
2253 #ifdef CONFIG_XFRM_SUB_POLICY
2254 	if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
2255 		return -EINVAL;
2256 #endif
2257 
2258 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2259 	old_pol = rcu_dereference_protected(sk->sk_policy[dir],
2260 				lockdep_is_held(&net->xfrm.xfrm_policy_lock));
2261 	if (pol) {
2262 		pol->curlft.add_time = ktime_get_real_seconds();
2263 		pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir, 0);
2264 		xfrm_sk_policy_link(pol, dir);
2265 	}
2266 	rcu_assign_pointer(sk->sk_policy[dir], pol);
2267 	if (old_pol) {
2268 		if (pol)
2269 			xfrm_policy_requeue(old_pol, pol);
2270 
2271 		/* Unlinking succeeds always. This is the only function
2272 		 * allowed to delete or replace socket policy.
2273 		 */
2274 		xfrm_sk_policy_unlink(old_pol, dir);
2275 	}
2276 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2277 
2278 	if (old_pol) {
2279 		xfrm_policy_kill(old_pol);
2280 	}
2281 	return 0;
2282 }
2283 
2284 static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
2285 {
2286 	struct xfrm_policy *newp = xfrm_policy_alloc(xp_net(old), GFP_ATOMIC);
2287 	struct net *net = xp_net(old);
2288 
2289 	if (newp) {
2290 		newp->selector = old->selector;
2291 		if (security_xfrm_policy_clone(old->security,
2292 					       &newp->security)) {
2293 			kfree(newp);
2294 			return NULL;  /* ENOMEM */
2295 		}
2296 		newp->lft = old->lft;
2297 		newp->curlft = old->curlft;
2298 		newp->mark = old->mark;
2299 		newp->if_id = old->if_id;
2300 		newp->action = old->action;
2301 		newp->flags = old->flags;
2302 		newp->xfrm_nr = old->xfrm_nr;
2303 		newp->index = old->index;
2304 		newp->type = old->type;
2305 		newp->family = old->family;
2306 		memcpy(newp->xfrm_vec, old->xfrm_vec,
2307 		       newp->xfrm_nr*sizeof(struct xfrm_tmpl));
2308 		spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2309 		xfrm_sk_policy_link(newp, dir);
2310 		spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2311 		xfrm_pol_put(newp);
2312 	}
2313 	return newp;
2314 }
2315 
2316 int __xfrm_sk_clone_policy(struct sock *sk, const struct sock *osk)
2317 {
2318 	const struct xfrm_policy *p;
2319 	struct xfrm_policy *np;
2320 	int i, ret = 0;
2321 
2322 	rcu_read_lock();
2323 	for (i = 0; i < 2; i++) {
2324 		p = rcu_dereference(osk->sk_policy[i]);
2325 		if (p) {
2326 			np = clone_policy(p, i);
2327 			if (unlikely(!np)) {
2328 				ret = -ENOMEM;
2329 				break;
2330 			}
2331 			rcu_assign_pointer(sk->sk_policy[i], np);
2332 		}
2333 	}
2334 	rcu_read_unlock();
2335 	return ret;
2336 }
2337 
2338 static int
2339 xfrm_get_saddr(struct net *net, int oif, xfrm_address_t *local,
2340 	       xfrm_address_t *remote, unsigned short family, u32 mark)
2341 {
2342 	int err;
2343 	const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2344 
2345 	if (unlikely(afinfo == NULL))
2346 		return -EINVAL;
2347 	err = afinfo->get_saddr(net, oif, local, remote, mark);
2348 	rcu_read_unlock();
2349 	return err;
2350 }
2351 
2352 /* Resolve list of templates for the flow, given policy. */
2353 
2354 static int
2355 xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
2356 		      struct xfrm_state **xfrm, unsigned short family)
2357 {
2358 	struct net *net = xp_net(policy);
2359 	int nx;
2360 	int i, error;
2361 	xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
2362 	xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
2363 	xfrm_address_t tmp;
2364 
2365 	for (nx = 0, i = 0; i < policy->xfrm_nr; i++) {
2366 		struct xfrm_state *x;
2367 		xfrm_address_t *remote = daddr;
2368 		xfrm_address_t *local  = saddr;
2369 		struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
2370 
2371 		if (tmpl->mode == XFRM_MODE_TUNNEL ||
2372 		    tmpl->mode == XFRM_MODE_BEET) {
2373 			remote = &tmpl->id.daddr;
2374 			local = &tmpl->saddr;
2375 			if (xfrm_addr_any(local, tmpl->encap_family)) {
2376 				error = xfrm_get_saddr(net, fl->flowi_oif,
2377 						       &tmp, remote,
2378 						       tmpl->encap_family, 0);
2379 				if (error)
2380 					goto fail;
2381 				local = &tmp;
2382 			}
2383 		}
2384 
2385 		x = xfrm_state_find(remote, local, fl, tmpl, policy, &error,
2386 				    family, policy->if_id);
2387 
2388 		if (x && x->km.state == XFRM_STATE_VALID) {
2389 			xfrm[nx++] = x;
2390 			daddr = remote;
2391 			saddr = local;
2392 			continue;
2393 		}
2394 		if (x) {
2395 			error = (x->km.state == XFRM_STATE_ERROR ?
2396 				 -EINVAL : -EAGAIN);
2397 			xfrm_state_put(x);
2398 		} else if (error == -ESRCH) {
2399 			error = -EAGAIN;
2400 		}
2401 
2402 		if (!tmpl->optional)
2403 			goto fail;
2404 	}
2405 	return nx;
2406 
2407 fail:
2408 	for (nx--; nx >= 0; nx--)
2409 		xfrm_state_put(xfrm[nx]);
2410 	return error;
2411 }
2412 
2413 static int
2414 xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, const struct flowi *fl,
2415 		  struct xfrm_state **xfrm, unsigned short family)
2416 {
2417 	struct xfrm_state *tp[XFRM_MAX_DEPTH];
2418 	struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
2419 	int cnx = 0;
2420 	int error;
2421 	int ret;
2422 	int i;
2423 
2424 	for (i = 0; i < npols; i++) {
2425 		if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
2426 			error = -ENOBUFS;
2427 			goto fail;
2428 		}
2429 
2430 		ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
2431 		if (ret < 0) {
2432 			error = ret;
2433 			goto fail;
2434 		} else
2435 			cnx += ret;
2436 	}
2437 
2438 	/* found states are sorted for outbound processing */
2439 	if (npols > 1)
2440 		xfrm_state_sort(xfrm, tpp, cnx, family);
2441 
2442 	return cnx;
2443 
2444  fail:
2445 	for (cnx--; cnx >= 0; cnx--)
2446 		xfrm_state_put(tpp[cnx]);
2447 	return error;
2448 
2449 }
2450 
2451 static int xfrm_get_tos(const struct flowi *fl, int family)
2452 {
2453 	const struct xfrm_policy_afinfo *afinfo;
2454 	int tos;
2455 
2456 	afinfo = xfrm_policy_get_afinfo(family);
2457 	if (!afinfo)
2458 		return 0;
2459 
2460 	tos = afinfo->get_tos(fl);
2461 
2462 	rcu_read_unlock();
2463 
2464 	return tos;
2465 }
2466 
2467 static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
2468 {
2469 	const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2470 	struct dst_ops *dst_ops;
2471 	struct xfrm_dst *xdst;
2472 
2473 	if (!afinfo)
2474 		return ERR_PTR(-EINVAL);
2475 
2476 	switch (family) {
2477 	case AF_INET:
2478 		dst_ops = &net->xfrm.xfrm4_dst_ops;
2479 		break;
2480 #if IS_ENABLED(CONFIG_IPV6)
2481 	case AF_INET6:
2482 		dst_ops = &net->xfrm.xfrm6_dst_ops;
2483 		break;
2484 #endif
2485 	default:
2486 		BUG();
2487 	}
2488 	xdst = dst_alloc(dst_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2489 
2490 	if (likely(xdst)) {
2491 		struct dst_entry *dst = &xdst->u.dst;
2492 
2493 		memset(dst + 1, 0, sizeof(*xdst) - sizeof(*dst));
2494 	} else
2495 		xdst = ERR_PTR(-ENOBUFS);
2496 
2497 	rcu_read_unlock();
2498 
2499 	return xdst;
2500 }
2501 
2502 static inline int xfrm_init_path(struct xfrm_dst *path, struct dst_entry *dst,
2503 				 int nfheader_len)
2504 {
2505 	const struct xfrm_policy_afinfo *afinfo =
2506 		xfrm_policy_get_afinfo(dst->ops->family);
2507 	int err;
2508 
2509 	if (!afinfo)
2510 		return -EINVAL;
2511 
2512 	err = afinfo->init_path(path, dst, nfheader_len);
2513 
2514 	rcu_read_unlock();
2515 
2516 	return err;
2517 }
2518 
2519 static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
2520 				const struct flowi *fl)
2521 {
2522 	const struct xfrm_policy_afinfo *afinfo =
2523 		xfrm_policy_get_afinfo(xdst->u.dst.ops->family);
2524 	int err;
2525 
2526 	if (!afinfo)
2527 		return -EINVAL;
2528 
2529 	err = afinfo->fill_dst(xdst, dev, fl);
2530 
2531 	rcu_read_unlock();
2532 
2533 	return err;
2534 }
2535 
2536 
2537 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
2538  * all the metrics... Shortly, bundle a bundle.
2539  */
2540 
2541 static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
2542 					    struct xfrm_state **xfrm,
2543 					    struct xfrm_dst **bundle,
2544 					    int nx,
2545 					    const struct flowi *fl,
2546 					    struct dst_entry *dst)
2547 {
2548 	struct net *net = xp_net(policy);
2549 	unsigned long now = jiffies;
2550 	struct net_device *dev;
2551 	struct xfrm_mode *inner_mode;
2552 	struct xfrm_dst *xdst_prev = NULL;
2553 	struct xfrm_dst *xdst0 = NULL;
2554 	int i = 0;
2555 	int err;
2556 	int header_len = 0;
2557 	int nfheader_len = 0;
2558 	int trailer_len = 0;
2559 	int tos;
2560 	int family = policy->selector.family;
2561 	xfrm_address_t saddr, daddr;
2562 
2563 	xfrm_flowi_addr_get(fl, &saddr, &daddr, family);
2564 
2565 	tos = xfrm_get_tos(fl, family);
2566 
2567 	dst_hold(dst);
2568 
2569 	for (; i < nx; i++) {
2570 		struct xfrm_dst *xdst = xfrm_alloc_dst(net, family);
2571 		struct dst_entry *dst1 = &xdst->u.dst;
2572 
2573 		err = PTR_ERR(xdst);
2574 		if (IS_ERR(xdst)) {
2575 			dst_release(dst);
2576 			goto put_states;
2577 		}
2578 
2579 		bundle[i] = xdst;
2580 		if (!xdst_prev)
2581 			xdst0 = xdst;
2582 		else
2583 			/* Ref count is taken during xfrm_alloc_dst()
2584 			 * No need to do dst_clone() on dst1
2585 			 */
2586 			xfrm_dst_set_child(xdst_prev, &xdst->u.dst);
2587 
2588 		if (xfrm[i]->sel.family == AF_UNSPEC) {
2589 			inner_mode = xfrm_ip2inner_mode(xfrm[i],
2590 							xfrm_af2proto(family));
2591 			if (!inner_mode) {
2592 				err = -EAFNOSUPPORT;
2593 				dst_release(dst);
2594 				goto put_states;
2595 			}
2596 		} else
2597 			inner_mode = xfrm[i]->inner_mode;
2598 
2599 		xdst->route = dst;
2600 		dst_copy_metrics(dst1, dst);
2601 
2602 		if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
2603 			__u32 mark = xfrm_smark_get(fl->flowi_mark, xfrm[i]);
2604 
2605 			family = xfrm[i]->props.family;
2606 			dst = xfrm_dst_lookup(xfrm[i], tos, fl->flowi_oif,
2607 					      &saddr, &daddr, family, mark);
2608 			err = PTR_ERR(dst);
2609 			if (IS_ERR(dst))
2610 				goto put_states;
2611 		} else
2612 			dst_hold(dst);
2613 
2614 		dst1->xfrm = xfrm[i];
2615 		xdst->xfrm_genid = xfrm[i]->genid;
2616 
2617 		dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
2618 		dst1->flags |= DST_HOST;
2619 		dst1->lastuse = now;
2620 
2621 		dst1->input = dst_discard;
2622 		dst1->output = inner_mode->afinfo->output;
2623 
2624 		xdst_prev = xdst;
2625 
2626 		header_len += xfrm[i]->props.header_len;
2627 		if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
2628 			nfheader_len += xfrm[i]->props.header_len;
2629 		trailer_len += xfrm[i]->props.trailer_len;
2630 	}
2631 
2632 	xfrm_dst_set_child(xdst_prev, dst);
2633 	xdst0->path = dst;
2634 
2635 	err = -ENODEV;
2636 	dev = dst->dev;
2637 	if (!dev)
2638 		goto free_dst;
2639 
2640 	xfrm_init_path(xdst0, dst, nfheader_len);
2641 	xfrm_init_pmtu(bundle, nx);
2642 
2643 	for (xdst_prev = xdst0; xdst_prev != (struct xfrm_dst *)dst;
2644 	     xdst_prev = (struct xfrm_dst *) xfrm_dst_child(&xdst_prev->u.dst)) {
2645 		err = xfrm_fill_dst(xdst_prev, dev, fl);
2646 		if (err)
2647 			goto free_dst;
2648 
2649 		xdst_prev->u.dst.header_len = header_len;
2650 		xdst_prev->u.dst.trailer_len = trailer_len;
2651 		header_len -= xdst_prev->u.dst.xfrm->props.header_len;
2652 		trailer_len -= xdst_prev->u.dst.xfrm->props.trailer_len;
2653 	}
2654 
2655 	return &xdst0->u.dst;
2656 
2657 put_states:
2658 	for (; i < nx; i++)
2659 		xfrm_state_put(xfrm[i]);
2660 free_dst:
2661 	if (xdst0)
2662 		dst_release_immediate(&xdst0->u.dst);
2663 
2664 	return ERR_PTR(err);
2665 }
2666 
2667 static int xfrm_expand_policies(const struct flowi *fl, u16 family,
2668 				struct xfrm_policy **pols,
2669 				int *num_pols, int *num_xfrms)
2670 {
2671 	int i;
2672 
2673 	if (*num_pols == 0 || !pols[0]) {
2674 		*num_pols = 0;
2675 		*num_xfrms = 0;
2676 		return 0;
2677 	}
2678 	if (IS_ERR(pols[0]))
2679 		return PTR_ERR(pols[0]);
2680 
2681 	*num_xfrms = pols[0]->xfrm_nr;
2682 
2683 #ifdef CONFIG_XFRM_SUB_POLICY
2684 	if (pols[0] && pols[0]->action == XFRM_POLICY_ALLOW &&
2685 	    pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
2686 		pols[1] = xfrm_policy_lookup_bytype(xp_net(pols[0]),
2687 						    XFRM_POLICY_TYPE_MAIN,
2688 						    fl, family,
2689 						    XFRM_POLICY_OUT,
2690 						    pols[0]->if_id);
2691 		if (pols[1]) {
2692 			if (IS_ERR(pols[1])) {
2693 				xfrm_pols_put(pols, *num_pols);
2694 				return PTR_ERR(pols[1]);
2695 			}
2696 			(*num_pols)++;
2697 			(*num_xfrms) += pols[1]->xfrm_nr;
2698 		}
2699 	}
2700 #endif
2701 	for (i = 0; i < *num_pols; i++) {
2702 		if (pols[i]->action != XFRM_POLICY_ALLOW) {
2703 			*num_xfrms = -1;
2704 			break;
2705 		}
2706 	}
2707 
2708 	return 0;
2709 
2710 }
2711 
2712 static struct xfrm_dst *
2713 xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
2714 			       const struct flowi *fl, u16 family,
2715 			       struct dst_entry *dst_orig)
2716 {
2717 	struct net *net = xp_net(pols[0]);
2718 	struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
2719 	struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
2720 	struct xfrm_dst *xdst;
2721 	struct dst_entry *dst;
2722 	int err;
2723 
2724 	/* Try to instantiate a bundle */
2725 	err = xfrm_tmpl_resolve(pols, num_pols, fl, xfrm, family);
2726 	if (err <= 0) {
2727 		if (err == 0)
2728 			return NULL;
2729 
2730 		if (err != -EAGAIN)
2731 			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
2732 		return ERR_PTR(err);
2733 	}
2734 
2735 	dst = xfrm_bundle_create(pols[0], xfrm, bundle, err, fl, dst_orig);
2736 	if (IS_ERR(dst)) {
2737 		XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR);
2738 		return ERR_CAST(dst);
2739 	}
2740 
2741 	xdst = (struct xfrm_dst *)dst;
2742 	xdst->num_xfrms = err;
2743 	xdst->num_pols = num_pols;
2744 	memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
2745 	xdst->policy_genid = atomic_read(&pols[0]->genid);
2746 
2747 	return xdst;
2748 }
2749 
2750 static void xfrm_policy_queue_process(struct timer_list *t)
2751 {
2752 	struct sk_buff *skb;
2753 	struct sock *sk;
2754 	struct dst_entry *dst;
2755 	struct xfrm_policy *pol = from_timer(pol, t, polq.hold_timer);
2756 	struct net *net = xp_net(pol);
2757 	struct xfrm_policy_queue *pq = &pol->polq;
2758 	struct flowi fl;
2759 	struct sk_buff_head list;
2760 
2761 	spin_lock(&pq->hold_queue.lock);
2762 	skb = skb_peek(&pq->hold_queue);
2763 	if (!skb) {
2764 		spin_unlock(&pq->hold_queue.lock);
2765 		goto out;
2766 	}
2767 	dst = skb_dst(skb);
2768 	sk = skb->sk;
2769 	xfrm_decode_session(skb, &fl, dst->ops->family);
2770 	spin_unlock(&pq->hold_queue.lock);
2771 
2772 	dst_hold(xfrm_dst_path(dst));
2773 	dst = xfrm_lookup(net, xfrm_dst_path(dst), &fl, sk, XFRM_LOOKUP_QUEUE);
2774 	if (IS_ERR(dst))
2775 		goto purge_queue;
2776 
2777 	if (dst->flags & DST_XFRM_QUEUE) {
2778 		dst_release(dst);
2779 
2780 		if (pq->timeout >= XFRM_QUEUE_TMO_MAX)
2781 			goto purge_queue;
2782 
2783 		pq->timeout = pq->timeout << 1;
2784 		if (!mod_timer(&pq->hold_timer, jiffies + pq->timeout))
2785 			xfrm_pol_hold(pol);
2786 		goto out;
2787 	}
2788 
2789 	dst_release(dst);
2790 
2791 	__skb_queue_head_init(&list);
2792 
2793 	spin_lock(&pq->hold_queue.lock);
2794 	pq->timeout = 0;
2795 	skb_queue_splice_init(&pq->hold_queue, &list);
2796 	spin_unlock(&pq->hold_queue.lock);
2797 
2798 	while (!skb_queue_empty(&list)) {
2799 		skb = __skb_dequeue(&list);
2800 
2801 		xfrm_decode_session(skb, &fl, skb_dst(skb)->ops->family);
2802 		dst_hold(xfrm_dst_path(skb_dst(skb)));
2803 		dst = xfrm_lookup(net, xfrm_dst_path(skb_dst(skb)), &fl, skb->sk, 0);
2804 		if (IS_ERR(dst)) {
2805 			kfree_skb(skb);
2806 			continue;
2807 		}
2808 
2809 		nf_reset(skb);
2810 		skb_dst_drop(skb);
2811 		skb_dst_set(skb, dst);
2812 
2813 		dst_output(net, skb->sk, skb);
2814 	}
2815 
2816 out:
2817 	xfrm_pol_put(pol);
2818 	return;
2819 
2820 purge_queue:
2821 	pq->timeout = 0;
2822 	skb_queue_purge(&pq->hold_queue);
2823 	xfrm_pol_put(pol);
2824 }
2825 
2826 static int xdst_queue_output(struct net *net, struct sock *sk, struct sk_buff *skb)
2827 {
2828 	unsigned long sched_next;
2829 	struct dst_entry *dst = skb_dst(skb);
2830 	struct xfrm_dst *xdst = (struct xfrm_dst *) dst;
2831 	struct xfrm_policy *pol = xdst->pols[0];
2832 	struct xfrm_policy_queue *pq = &pol->polq;
2833 
2834 	if (unlikely(skb_fclone_busy(sk, skb))) {
2835 		kfree_skb(skb);
2836 		return 0;
2837 	}
2838 
2839 	if (pq->hold_queue.qlen > XFRM_MAX_QUEUE_LEN) {
2840 		kfree_skb(skb);
2841 		return -EAGAIN;
2842 	}
2843 
2844 	skb_dst_force(skb);
2845 
2846 	spin_lock_bh(&pq->hold_queue.lock);
2847 
2848 	if (!pq->timeout)
2849 		pq->timeout = XFRM_QUEUE_TMO_MIN;
2850 
2851 	sched_next = jiffies + pq->timeout;
2852 
2853 	if (del_timer(&pq->hold_timer)) {
2854 		if (time_before(pq->hold_timer.expires, sched_next))
2855 			sched_next = pq->hold_timer.expires;
2856 		xfrm_pol_put(pol);
2857 	}
2858 
2859 	__skb_queue_tail(&pq->hold_queue, skb);
2860 	if (!mod_timer(&pq->hold_timer, sched_next))
2861 		xfrm_pol_hold(pol);
2862 
2863 	spin_unlock_bh(&pq->hold_queue.lock);
2864 
2865 	return 0;
2866 }
2867 
2868 static struct xfrm_dst *xfrm_create_dummy_bundle(struct net *net,
2869 						 struct xfrm_flo *xflo,
2870 						 const struct flowi *fl,
2871 						 int num_xfrms,
2872 						 u16 family)
2873 {
2874 	int err;
2875 	struct net_device *dev;
2876 	struct dst_entry *dst;
2877 	struct dst_entry *dst1;
2878 	struct xfrm_dst *xdst;
2879 
2880 	xdst = xfrm_alloc_dst(net, family);
2881 	if (IS_ERR(xdst))
2882 		return xdst;
2883 
2884 	if (!(xflo->flags & XFRM_LOOKUP_QUEUE) ||
2885 	    net->xfrm.sysctl_larval_drop ||
2886 	    num_xfrms <= 0)
2887 		return xdst;
2888 
2889 	dst = xflo->dst_orig;
2890 	dst1 = &xdst->u.dst;
2891 	dst_hold(dst);
2892 	xdst->route = dst;
2893 
2894 	dst_copy_metrics(dst1, dst);
2895 
2896 	dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
2897 	dst1->flags |= DST_HOST | DST_XFRM_QUEUE;
2898 	dst1->lastuse = jiffies;
2899 
2900 	dst1->input = dst_discard;
2901 	dst1->output = xdst_queue_output;
2902 
2903 	dst_hold(dst);
2904 	xfrm_dst_set_child(xdst, dst);
2905 	xdst->path = dst;
2906 
2907 	xfrm_init_path((struct xfrm_dst *)dst1, dst, 0);
2908 
2909 	err = -ENODEV;
2910 	dev = dst->dev;
2911 	if (!dev)
2912 		goto free_dst;
2913 
2914 	err = xfrm_fill_dst(xdst, dev, fl);
2915 	if (err)
2916 		goto free_dst;
2917 
2918 out:
2919 	return xdst;
2920 
2921 free_dst:
2922 	dst_release(dst1);
2923 	xdst = ERR_PTR(err);
2924 	goto out;
2925 }
2926 
2927 static struct xfrm_dst *xfrm_bundle_lookup(struct net *net,
2928 					   const struct flowi *fl,
2929 					   u16 family, u8 dir,
2930 					   struct xfrm_flo *xflo, u32 if_id)
2931 {
2932 	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2933 	int num_pols = 0, num_xfrms = 0, err;
2934 	struct xfrm_dst *xdst;
2935 
2936 	/* Resolve policies to use if we couldn't get them from
2937 	 * previous cache entry */
2938 	num_pols = 1;
2939 	pols[0] = xfrm_policy_lookup(net, fl, family, dir, if_id);
2940 	err = xfrm_expand_policies(fl, family, pols,
2941 					   &num_pols, &num_xfrms);
2942 	if (err < 0)
2943 		goto inc_error;
2944 	if (num_pols == 0)
2945 		return NULL;
2946 	if (num_xfrms <= 0)
2947 		goto make_dummy_bundle;
2948 
2949 	xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family,
2950 					      xflo->dst_orig);
2951 	if (IS_ERR(xdst)) {
2952 		err = PTR_ERR(xdst);
2953 		if (err == -EREMOTE) {
2954 			xfrm_pols_put(pols, num_pols);
2955 			return NULL;
2956 		}
2957 
2958 		if (err != -EAGAIN)
2959 			goto error;
2960 		goto make_dummy_bundle;
2961 	} else if (xdst == NULL) {
2962 		num_xfrms = 0;
2963 		goto make_dummy_bundle;
2964 	}
2965 
2966 	return xdst;
2967 
2968 make_dummy_bundle:
2969 	/* We found policies, but there's no bundles to instantiate:
2970 	 * either because the policy blocks, has no transformations or
2971 	 * we could not build template (no xfrm_states).*/
2972 	xdst = xfrm_create_dummy_bundle(net, xflo, fl, num_xfrms, family);
2973 	if (IS_ERR(xdst)) {
2974 		xfrm_pols_put(pols, num_pols);
2975 		return ERR_CAST(xdst);
2976 	}
2977 	xdst->num_pols = num_pols;
2978 	xdst->num_xfrms = num_xfrms;
2979 	memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
2980 
2981 	return xdst;
2982 
2983 inc_error:
2984 	XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
2985 error:
2986 	xfrm_pols_put(pols, num_pols);
2987 	return ERR_PTR(err);
2988 }
2989 
2990 static struct dst_entry *make_blackhole(struct net *net, u16 family,
2991 					struct dst_entry *dst_orig)
2992 {
2993 	const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2994 	struct dst_entry *ret;
2995 
2996 	if (!afinfo) {
2997 		dst_release(dst_orig);
2998 		return ERR_PTR(-EINVAL);
2999 	} else {
3000 		ret = afinfo->blackhole_route(net, dst_orig);
3001 	}
3002 	rcu_read_unlock();
3003 
3004 	return ret;
3005 }
3006 
3007 /* Finds/creates a bundle for given flow and if_id
3008  *
3009  * At the moment we eat a raw IP route. Mostly to speed up lookups
3010  * on interfaces with disabled IPsec.
3011  *
3012  * xfrm_lookup uses an if_id of 0 by default, and is provided for
3013  * compatibility
3014  */
3015 struct dst_entry *xfrm_lookup_with_ifid(struct net *net,
3016 					struct dst_entry *dst_orig,
3017 					const struct flowi *fl,
3018 					const struct sock *sk,
3019 					int flags, u32 if_id)
3020 {
3021 	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
3022 	struct xfrm_dst *xdst;
3023 	struct dst_entry *dst, *route;
3024 	u16 family = dst_orig->ops->family;
3025 	u8 dir = XFRM_POLICY_OUT;
3026 	int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
3027 
3028 	dst = NULL;
3029 	xdst = NULL;
3030 	route = NULL;
3031 
3032 	sk = sk_const_to_full_sk(sk);
3033 	if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
3034 		num_pols = 1;
3035 		pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, family,
3036 						if_id);
3037 		err = xfrm_expand_policies(fl, family, pols,
3038 					   &num_pols, &num_xfrms);
3039 		if (err < 0)
3040 			goto dropdst;
3041 
3042 		if (num_pols) {
3043 			if (num_xfrms <= 0) {
3044 				drop_pols = num_pols;
3045 				goto no_transform;
3046 			}
3047 
3048 			xdst = xfrm_resolve_and_create_bundle(
3049 					pols, num_pols, fl,
3050 					family, dst_orig);
3051 
3052 			if (IS_ERR(xdst)) {
3053 				xfrm_pols_put(pols, num_pols);
3054 				err = PTR_ERR(xdst);
3055 				if (err == -EREMOTE)
3056 					goto nopol;
3057 
3058 				goto dropdst;
3059 			} else if (xdst == NULL) {
3060 				num_xfrms = 0;
3061 				drop_pols = num_pols;
3062 				goto no_transform;
3063 			}
3064 
3065 			route = xdst->route;
3066 		}
3067 	}
3068 
3069 	if (xdst == NULL) {
3070 		struct xfrm_flo xflo;
3071 
3072 		xflo.dst_orig = dst_orig;
3073 		xflo.flags = flags;
3074 
3075 		/* To accelerate a bit...  */
3076 		if ((dst_orig->flags & DST_NOXFRM) ||
3077 		    !net->xfrm.policy_count[XFRM_POLICY_OUT])
3078 			goto nopol;
3079 
3080 		xdst = xfrm_bundle_lookup(net, fl, family, dir, &xflo, if_id);
3081 		if (xdst == NULL)
3082 			goto nopol;
3083 		if (IS_ERR(xdst)) {
3084 			err = PTR_ERR(xdst);
3085 			goto dropdst;
3086 		}
3087 
3088 		num_pols = xdst->num_pols;
3089 		num_xfrms = xdst->num_xfrms;
3090 		memcpy(pols, xdst->pols, sizeof(struct xfrm_policy *) * num_pols);
3091 		route = xdst->route;
3092 	}
3093 
3094 	dst = &xdst->u.dst;
3095 	if (route == NULL && num_xfrms > 0) {
3096 		/* The only case when xfrm_bundle_lookup() returns a
3097 		 * bundle with null route, is when the template could
3098 		 * not be resolved. It means policies are there, but
3099 		 * bundle could not be created, since we don't yet
3100 		 * have the xfrm_state's. We need to wait for KM to
3101 		 * negotiate new SA's or bail out with error.*/
3102 		if (net->xfrm.sysctl_larval_drop) {
3103 			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
3104 			err = -EREMOTE;
3105 			goto error;
3106 		}
3107 
3108 		err = -EAGAIN;
3109 
3110 		XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
3111 		goto error;
3112 	}
3113 
3114 no_transform:
3115 	if (num_pols == 0)
3116 		goto nopol;
3117 
3118 	if ((flags & XFRM_LOOKUP_ICMP) &&
3119 	    !(pols[0]->flags & XFRM_POLICY_ICMP)) {
3120 		err = -ENOENT;
3121 		goto error;
3122 	}
3123 
3124 	for (i = 0; i < num_pols; i++)
3125 		pols[i]->curlft.use_time = ktime_get_real_seconds();
3126 
3127 	if (num_xfrms < 0) {
3128 		/* Prohibit the flow */
3129 		XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLBLOCK);
3130 		err = -EPERM;
3131 		goto error;
3132 	} else if (num_xfrms > 0) {
3133 		/* Flow transformed */
3134 		dst_release(dst_orig);
3135 	} else {
3136 		/* Flow passes untransformed */
3137 		dst_release(dst);
3138 		dst = dst_orig;
3139 	}
3140 ok:
3141 	xfrm_pols_put(pols, drop_pols);
3142 	if (dst && dst->xfrm &&
3143 	    dst->xfrm->props.mode == XFRM_MODE_TUNNEL)
3144 		dst->flags |= DST_XFRM_TUNNEL;
3145 	return dst;
3146 
3147 nopol:
3148 	if (!(flags & XFRM_LOOKUP_ICMP)) {
3149 		dst = dst_orig;
3150 		goto ok;
3151 	}
3152 	err = -ENOENT;
3153 error:
3154 	dst_release(dst);
3155 dropdst:
3156 	if (!(flags & XFRM_LOOKUP_KEEP_DST_REF))
3157 		dst_release(dst_orig);
3158 	xfrm_pols_put(pols, drop_pols);
3159 	return ERR_PTR(err);
3160 }
3161 EXPORT_SYMBOL(xfrm_lookup_with_ifid);
3162 
3163 /* Main function: finds/creates a bundle for given flow.
3164  *
3165  * At the moment we eat a raw IP route. Mostly to speed up lookups
3166  * on interfaces with disabled IPsec.
3167  */
3168 struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
3169 			      const struct flowi *fl, const struct sock *sk,
3170 			      int flags)
3171 {
3172 	return xfrm_lookup_with_ifid(net, dst_orig, fl, sk, flags, 0);
3173 }
3174 EXPORT_SYMBOL(xfrm_lookup);
3175 
3176 /* Callers of xfrm_lookup_route() must ensure a call to dst_output().
3177  * Otherwise we may send out blackholed packets.
3178  */
3179 struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
3180 				    const struct flowi *fl,
3181 				    const struct sock *sk, int flags)
3182 {
3183 	struct dst_entry *dst = xfrm_lookup(net, dst_orig, fl, sk,
3184 					    flags | XFRM_LOOKUP_QUEUE |
3185 					    XFRM_LOOKUP_KEEP_DST_REF);
3186 
3187 	if (IS_ERR(dst) && PTR_ERR(dst) == -EREMOTE)
3188 		return make_blackhole(net, dst_orig->ops->family, dst_orig);
3189 
3190 	if (IS_ERR(dst))
3191 		dst_release(dst_orig);
3192 
3193 	return dst;
3194 }
3195 EXPORT_SYMBOL(xfrm_lookup_route);
3196 
3197 static inline int
3198 xfrm_secpath_reject(int idx, struct sk_buff *skb, const struct flowi *fl)
3199 {
3200 	struct sec_path *sp = skb_sec_path(skb);
3201 	struct xfrm_state *x;
3202 
3203 	if (!sp || idx < 0 || idx >= sp->len)
3204 		return 0;
3205 	x = sp->xvec[idx];
3206 	if (!x->type->reject)
3207 		return 0;
3208 	return x->type->reject(x, skb, fl);
3209 }
3210 
3211 /* When skb is transformed back to its "native" form, we have to
3212  * check policy restrictions. At the moment we make this in maximally
3213  * stupid way. Shame on me. :-) Of course, connected sockets must
3214  * have policy cached at them.
3215  */
3216 
3217 static inline int
3218 xfrm_state_ok(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x,
3219 	      unsigned short family)
3220 {
3221 	if (xfrm_state_kern(x))
3222 		return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
3223 	return	x->id.proto == tmpl->id.proto &&
3224 		(x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
3225 		(x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
3226 		x->props.mode == tmpl->mode &&
3227 		(tmpl->allalgs || (tmpl->aalgos & (1<<x->props.aalgo)) ||
3228 		 !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
3229 		!(x->props.mode != XFRM_MODE_TRANSPORT &&
3230 		  xfrm_state_addr_cmp(tmpl, x, family));
3231 }
3232 
3233 /*
3234  * 0 or more than 0 is returned when validation is succeeded (either bypass
3235  * because of optional transport mode, or next index of the mathced secpath
3236  * state with the template.
3237  * -1 is returned when no matching template is found.
3238  * Otherwise "-2 - errored_index" is returned.
3239  */
3240 static inline int
3241 xfrm_policy_ok(const struct xfrm_tmpl *tmpl, const struct sec_path *sp, int start,
3242 	       unsigned short family)
3243 {
3244 	int idx = start;
3245 
3246 	if (tmpl->optional) {
3247 		if (tmpl->mode == XFRM_MODE_TRANSPORT)
3248 			return start;
3249 	} else
3250 		start = -1;
3251 	for (; idx < sp->len; idx++) {
3252 		if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
3253 			return ++idx;
3254 		if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
3255 			if (start == -1)
3256 				start = -2-idx;
3257 			break;
3258 		}
3259 	}
3260 	return start;
3261 }
3262 
3263 int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
3264 			  unsigned int family, int reverse)
3265 {
3266 	const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
3267 	int err;
3268 
3269 	if (unlikely(afinfo == NULL))
3270 		return -EAFNOSUPPORT;
3271 
3272 	afinfo->decode_session(skb, fl, reverse);
3273 
3274 	err = security_xfrm_decode_session(skb, &fl->flowi_secid);
3275 	rcu_read_unlock();
3276 	return err;
3277 }
3278 EXPORT_SYMBOL(__xfrm_decode_session);
3279 
3280 static inline int secpath_has_nontransport(const struct sec_path *sp, int k, int *idxp)
3281 {
3282 	for (; k < sp->len; k++) {
3283 		if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
3284 			*idxp = k;
3285 			return 1;
3286 		}
3287 	}
3288 
3289 	return 0;
3290 }
3291 
3292 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
3293 			unsigned short family)
3294 {
3295 	struct net *net = dev_net(skb->dev);
3296 	struct xfrm_policy *pol;
3297 	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
3298 	int npols = 0;
3299 	int xfrm_nr;
3300 	int pi;
3301 	int reverse;
3302 	struct flowi fl;
3303 	int xerr_idx = -1;
3304 	const struct xfrm_if_cb *ifcb;
3305 	struct sec_path *sp;
3306 	struct xfrm_if *xi;
3307 	u32 if_id = 0;
3308 
3309 	rcu_read_lock();
3310 	ifcb = xfrm_if_get_cb();
3311 
3312 	if (ifcb) {
3313 		xi = ifcb->decode_session(skb);
3314 		if (xi)
3315 			if_id = xi->p.if_id;
3316 	}
3317 	rcu_read_unlock();
3318 
3319 	reverse = dir & ~XFRM_POLICY_MASK;
3320 	dir &= XFRM_POLICY_MASK;
3321 
3322 	if (__xfrm_decode_session(skb, &fl, family, reverse) < 0) {
3323 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
3324 		return 0;
3325 	}
3326 
3327 	nf_nat_decode_session(skb, &fl, family);
3328 
3329 	/* First, check used SA against their selectors. */
3330 	sp = skb_sec_path(skb);
3331 	if (sp) {
3332 		int i;
3333 
3334 		for (i = sp->len - 1; i >= 0; i--) {
3335 			struct xfrm_state *x = sp->xvec[i];
3336 			if (!xfrm_selector_match(&x->sel, &fl, family)) {
3337 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
3338 				return 0;
3339 			}
3340 		}
3341 	}
3342 
3343 	pol = NULL;
3344 	sk = sk_to_full_sk(sk);
3345 	if (sk && sk->sk_policy[dir]) {
3346 		pol = xfrm_sk_policy_lookup(sk, dir, &fl, family, if_id);
3347 		if (IS_ERR(pol)) {
3348 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
3349 			return 0;
3350 		}
3351 	}
3352 
3353 	if (!pol)
3354 		pol = xfrm_policy_lookup(net, &fl, family, dir, if_id);
3355 
3356 	if (IS_ERR(pol)) {
3357 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
3358 		return 0;
3359 	}
3360 
3361 	if (!pol) {
3362 		if (sp && secpath_has_nontransport(sp, 0, &xerr_idx)) {
3363 			xfrm_secpath_reject(xerr_idx, skb, &fl);
3364 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
3365 			return 0;
3366 		}
3367 		return 1;
3368 	}
3369 
3370 	pol->curlft.use_time = ktime_get_real_seconds();
3371 
3372 	pols[0] = pol;
3373 	npols++;
3374 #ifdef CONFIG_XFRM_SUB_POLICY
3375 	if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
3376 		pols[1] = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN,
3377 						    &fl, family,
3378 						    XFRM_POLICY_IN, if_id);
3379 		if (pols[1]) {
3380 			if (IS_ERR(pols[1])) {
3381 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
3382 				return 0;
3383 			}
3384 			pols[1]->curlft.use_time = ktime_get_real_seconds();
3385 			npols++;
3386 		}
3387 	}
3388 #endif
3389 
3390 	if (pol->action == XFRM_POLICY_ALLOW) {
3391 		static struct sec_path dummy;
3392 		struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
3393 		struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
3394 		struct xfrm_tmpl **tpp = tp;
3395 		int ti = 0;
3396 		int i, k;
3397 
3398 		sp = skb_sec_path(skb);
3399 		if (!sp)
3400 			sp = &dummy;
3401 
3402 		for (pi = 0; pi < npols; pi++) {
3403 			if (pols[pi] != pol &&
3404 			    pols[pi]->action != XFRM_POLICY_ALLOW) {
3405 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
3406 				goto reject;
3407 			}
3408 			if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH) {
3409 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
3410 				goto reject_error;
3411 			}
3412 			for (i = 0; i < pols[pi]->xfrm_nr; i++)
3413 				tpp[ti++] = &pols[pi]->xfrm_vec[i];
3414 		}
3415 		xfrm_nr = ti;
3416 		if (npols > 1) {
3417 			xfrm_tmpl_sort(stp, tpp, xfrm_nr, family, net);
3418 			tpp = stp;
3419 		}
3420 
3421 		/* For each tunnel xfrm, find the first matching tmpl.
3422 		 * For each tmpl before that, find corresponding xfrm.
3423 		 * Order is _important_. Later we will implement
3424 		 * some barriers, but at the moment barriers
3425 		 * are implied between each two transformations.
3426 		 */
3427 		for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
3428 			k = xfrm_policy_ok(tpp[i], sp, k, family);
3429 			if (k < 0) {
3430 				if (k < -1)
3431 					/* "-2 - errored_index" returned */
3432 					xerr_idx = -(2+k);
3433 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
3434 				goto reject;
3435 			}
3436 		}
3437 
3438 		if (secpath_has_nontransport(sp, k, &xerr_idx)) {
3439 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
3440 			goto reject;
3441 		}
3442 
3443 		xfrm_pols_put(pols, npols);
3444 		return 1;
3445 	}
3446 	XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
3447 
3448 reject:
3449 	xfrm_secpath_reject(xerr_idx, skb, &fl);
3450 reject_error:
3451 	xfrm_pols_put(pols, npols);
3452 	return 0;
3453 }
3454 EXPORT_SYMBOL(__xfrm_policy_check);
3455 
3456 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
3457 {
3458 	struct net *net = dev_net(skb->dev);
3459 	struct flowi fl;
3460 	struct dst_entry *dst;
3461 	int res = 1;
3462 
3463 	if (xfrm_decode_session(skb, &fl, family) < 0) {
3464 		XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
3465 		return 0;
3466 	}
3467 
3468 	skb_dst_force(skb);
3469 	if (!skb_dst(skb)) {
3470 		XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
3471 		return 0;
3472 	}
3473 
3474 	dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, XFRM_LOOKUP_QUEUE);
3475 	if (IS_ERR(dst)) {
3476 		res = 0;
3477 		dst = NULL;
3478 	}
3479 	skb_dst_set(skb, dst);
3480 	return res;
3481 }
3482 EXPORT_SYMBOL(__xfrm_route_forward);
3483 
3484 /* Optimize later using cookies and generation ids. */
3485 
3486 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
3487 {
3488 	/* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
3489 	 * to DST_OBSOLETE_FORCE_CHK to force all XFRM destinations to
3490 	 * get validated by dst_ops->check on every use.  We do this
3491 	 * because when a normal route referenced by an XFRM dst is
3492 	 * obsoleted we do not go looking around for all parent
3493 	 * referencing XFRM dsts so that we can invalidate them.  It
3494 	 * is just too much work.  Instead we make the checks here on
3495 	 * every use.  For example:
3496 	 *
3497 	 *	XFRM dst A --> IPv4 dst X
3498 	 *
3499 	 * X is the "xdst->route" of A (X is also the "dst->path" of A
3500 	 * in this example).  If X is marked obsolete, "A" will not
3501 	 * notice.  That's what we are validating here via the
3502 	 * stale_bundle() check.
3503 	 *
3504 	 * When a dst is removed from the fib tree, DST_OBSOLETE_DEAD will
3505 	 * be marked on it.
3506 	 * This will force stale_bundle() to fail on any xdst bundle with
3507 	 * this dst linked in it.
3508 	 */
3509 	if (dst->obsolete < 0 && !stale_bundle(dst))
3510 		return dst;
3511 
3512 	return NULL;
3513 }
3514 
3515 static int stale_bundle(struct dst_entry *dst)
3516 {
3517 	return !xfrm_bundle_ok((struct xfrm_dst *)dst);
3518 }
3519 
3520 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
3521 {
3522 	while ((dst = xfrm_dst_child(dst)) && dst->xfrm && dst->dev == dev) {
3523 		dst->dev = dev_net(dev)->loopback_dev;
3524 		dev_hold(dst->dev);
3525 		dev_put(dev);
3526 	}
3527 }
3528 EXPORT_SYMBOL(xfrm_dst_ifdown);
3529 
3530 static void xfrm_link_failure(struct sk_buff *skb)
3531 {
3532 	/* Impossible. Such dst must be popped before reaches point of failure. */
3533 }
3534 
3535 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
3536 {
3537 	if (dst) {
3538 		if (dst->obsolete) {
3539 			dst_release(dst);
3540 			dst = NULL;
3541 		}
3542 	}
3543 	return dst;
3544 }
3545 
3546 static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr)
3547 {
3548 	while (nr--) {
3549 		struct xfrm_dst *xdst = bundle[nr];
3550 		u32 pmtu, route_mtu_cached;
3551 		struct dst_entry *dst;
3552 
3553 		dst = &xdst->u.dst;
3554 		pmtu = dst_mtu(xfrm_dst_child(dst));
3555 		xdst->child_mtu_cached = pmtu;
3556 
3557 		pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
3558 
3559 		route_mtu_cached = dst_mtu(xdst->route);
3560 		xdst->route_mtu_cached = route_mtu_cached;
3561 
3562 		if (pmtu > route_mtu_cached)
3563 			pmtu = route_mtu_cached;
3564 
3565 		dst_metric_set(dst, RTAX_MTU, pmtu);
3566 	}
3567 }
3568 
3569 /* Check that the bundle accepts the flow and its components are
3570  * still valid.
3571  */
3572 
3573 static int xfrm_bundle_ok(struct xfrm_dst *first)
3574 {
3575 	struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
3576 	struct dst_entry *dst = &first->u.dst;
3577 	struct xfrm_dst *xdst;
3578 	int start_from, nr;
3579 	u32 mtu;
3580 
3581 	if (!dst_check(xfrm_dst_path(dst), ((struct xfrm_dst *)dst)->path_cookie) ||
3582 	    (dst->dev && !netif_running(dst->dev)))
3583 		return 0;
3584 
3585 	if (dst->flags & DST_XFRM_QUEUE)
3586 		return 1;
3587 
3588 	start_from = nr = 0;
3589 	do {
3590 		struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
3591 
3592 		if (dst->xfrm->km.state != XFRM_STATE_VALID)
3593 			return 0;
3594 		if (xdst->xfrm_genid != dst->xfrm->genid)
3595 			return 0;
3596 		if (xdst->num_pols > 0 &&
3597 		    xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
3598 			return 0;
3599 
3600 		bundle[nr++] = xdst;
3601 
3602 		mtu = dst_mtu(xfrm_dst_child(dst));
3603 		if (xdst->child_mtu_cached != mtu) {
3604 			start_from = nr;
3605 			xdst->child_mtu_cached = mtu;
3606 		}
3607 
3608 		if (!dst_check(xdst->route, xdst->route_cookie))
3609 			return 0;
3610 		mtu = dst_mtu(xdst->route);
3611 		if (xdst->route_mtu_cached != mtu) {
3612 			start_from = nr;
3613 			xdst->route_mtu_cached = mtu;
3614 		}
3615 
3616 		dst = xfrm_dst_child(dst);
3617 	} while (dst->xfrm);
3618 
3619 	if (likely(!start_from))
3620 		return 1;
3621 
3622 	xdst = bundle[start_from - 1];
3623 	mtu = xdst->child_mtu_cached;
3624 	while (start_from--) {
3625 		dst = &xdst->u.dst;
3626 
3627 		mtu = xfrm_state_mtu(dst->xfrm, mtu);
3628 		if (mtu > xdst->route_mtu_cached)
3629 			mtu = xdst->route_mtu_cached;
3630 		dst_metric_set(dst, RTAX_MTU, mtu);
3631 		if (!start_from)
3632 			break;
3633 
3634 		xdst = bundle[start_from - 1];
3635 		xdst->child_mtu_cached = mtu;
3636 	}
3637 
3638 	return 1;
3639 }
3640 
3641 static unsigned int xfrm_default_advmss(const struct dst_entry *dst)
3642 {
3643 	return dst_metric_advmss(xfrm_dst_path(dst));
3644 }
3645 
3646 static unsigned int xfrm_mtu(const struct dst_entry *dst)
3647 {
3648 	unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
3649 
3650 	return mtu ? : dst_mtu(xfrm_dst_path(dst));
3651 }
3652 
3653 static const void *xfrm_get_dst_nexthop(const struct dst_entry *dst,
3654 					const void *daddr)
3655 {
3656 	while (dst->xfrm) {
3657 		const struct xfrm_state *xfrm = dst->xfrm;
3658 
3659 		dst = xfrm_dst_child(dst);
3660 
3661 		if (xfrm->props.mode == XFRM_MODE_TRANSPORT)
3662 			continue;
3663 		if (xfrm->type->flags & XFRM_TYPE_REMOTE_COADDR)
3664 			daddr = xfrm->coaddr;
3665 		else if (!(xfrm->type->flags & XFRM_TYPE_LOCAL_COADDR))
3666 			daddr = &xfrm->id.daddr;
3667 	}
3668 	return daddr;
3669 }
3670 
3671 static struct neighbour *xfrm_neigh_lookup(const struct dst_entry *dst,
3672 					   struct sk_buff *skb,
3673 					   const void *daddr)
3674 {
3675 	const struct dst_entry *path = xfrm_dst_path(dst);
3676 
3677 	if (!skb)
3678 		daddr = xfrm_get_dst_nexthop(dst, daddr);
3679 	return path->ops->neigh_lookup(path, skb, daddr);
3680 }
3681 
3682 static void xfrm_confirm_neigh(const struct dst_entry *dst, const void *daddr)
3683 {
3684 	const struct dst_entry *path = xfrm_dst_path(dst);
3685 
3686 	daddr = xfrm_get_dst_nexthop(dst, daddr);
3687 	path->ops->confirm_neigh(path, daddr);
3688 }
3689 
3690 int xfrm_policy_register_afinfo(const struct xfrm_policy_afinfo *afinfo, int family)
3691 {
3692 	int err = 0;
3693 
3694 	if (WARN_ON(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
3695 		return -EAFNOSUPPORT;
3696 
3697 	spin_lock(&xfrm_policy_afinfo_lock);
3698 	if (unlikely(xfrm_policy_afinfo[family] != NULL))
3699 		err = -EEXIST;
3700 	else {
3701 		struct dst_ops *dst_ops = afinfo->dst_ops;
3702 		if (likely(dst_ops->kmem_cachep == NULL))
3703 			dst_ops->kmem_cachep = xfrm_dst_cache;
3704 		if (likely(dst_ops->check == NULL))
3705 			dst_ops->check = xfrm_dst_check;
3706 		if (likely(dst_ops->default_advmss == NULL))
3707 			dst_ops->default_advmss = xfrm_default_advmss;
3708 		if (likely(dst_ops->mtu == NULL))
3709 			dst_ops->mtu = xfrm_mtu;
3710 		if (likely(dst_ops->negative_advice == NULL))
3711 			dst_ops->negative_advice = xfrm_negative_advice;
3712 		if (likely(dst_ops->link_failure == NULL))
3713 			dst_ops->link_failure = xfrm_link_failure;
3714 		if (likely(dst_ops->neigh_lookup == NULL))
3715 			dst_ops->neigh_lookup = xfrm_neigh_lookup;
3716 		if (likely(!dst_ops->confirm_neigh))
3717 			dst_ops->confirm_neigh = xfrm_confirm_neigh;
3718 		rcu_assign_pointer(xfrm_policy_afinfo[family], afinfo);
3719 	}
3720 	spin_unlock(&xfrm_policy_afinfo_lock);
3721 
3722 	return err;
3723 }
3724 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
3725 
3726 void xfrm_policy_unregister_afinfo(const struct xfrm_policy_afinfo *afinfo)
3727 {
3728 	struct dst_ops *dst_ops = afinfo->dst_ops;
3729 	int i;
3730 
3731 	for (i = 0; i < ARRAY_SIZE(xfrm_policy_afinfo); i++) {
3732 		if (xfrm_policy_afinfo[i] != afinfo)
3733 			continue;
3734 		RCU_INIT_POINTER(xfrm_policy_afinfo[i], NULL);
3735 		break;
3736 	}
3737 
3738 	synchronize_rcu();
3739 
3740 	dst_ops->kmem_cachep = NULL;
3741 	dst_ops->check = NULL;
3742 	dst_ops->negative_advice = NULL;
3743 	dst_ops->link_failure = NULL;
3744 }
3745 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
3746 
3747 void xfrm_if_register_cb(const struct xfrm_if_cb *ifcb)
3748 {
3749 	spin_lock(&xfrm_if_cb_lock);
3750 	rcu_assign_pointer(xfrm_if_cb, ifcb);
3751 	spin_unlock(&xfrm_if_cb_lock);
3752 }
3753 EXPORT_SYMBOL(xfrm_if_register_cb);
3754 
3755 void xfrm_if_unregister_cb(void)
3756 {
3757 	RCU_INIT_POINTER(xfrm_if_cb, NULL);
3758 	synchronize_rcu();
3759 }
3760 EXPORT_SYMBOL(xfrm_if_unregister_cb);
3761 
3762 #ifdef CONFIG_XFRM_STATISTICS
3763 static int __net_init xfrm_statistics_init(struct net *net)
3764 {
3765 	int rv;
3766 	net->mib.xfrm_statistics = alloc_percpu(struct linux_xfrm_mib);
3767 	if (!net->mib.xfrm_statistics)
3768 		return -ENOMEM;
3769 	rv = xfrm_proc_init(net);
3770 	if (rv < 0)
3771 		free_percpu(net->mib.xfrm_statistics);
3772 	return rv;
3773 }
3774 
3775 static void xfrm_statistics_fini(struct net *net)
3776 {
3777 	xfrm_proc_fini(net);
3778 	free_percpu(net->mib.xfrm_statistics);
3779 }
3780 #else
3781 static int __net_init xfrm_statistics_init(struct net *net)
3782 {
3783 	return 0;
3784 }
3785 
3786 static void xfrm_statistics_fini(struct net *net)
3787 {
3788 }
3789 #endif
3790 
3791 static int __net_init xfrm_policy_init(struct net *net)
3792 {
3793 	unsigned int hmask, sz;
3794 	int dir, err;
3795 
3796 	if (net_eq(net, &init_net)) {
3797 		xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
3798 					   sizeof(struct xfrm_dst),
3799 					   0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
3800 					   NULL);
3801 		err = rhashtable_init(&xfrm_policy_inexact_table,
3802 				      &xfrm_pol_inexact_params);
3803 		BUG_ON(err);
3804 	}
3805 
3806 	hmask = 8 - 1;
3807 	sz = (hmask+1) * sizeof(struct hlist_head);
3808 
3809 	net->xfrm.policy_byidx = xfrm_hash_alloc(sz);
3810 	if (!net->xfrm.policy_byidx)
3811 		goto out_byidx;
3812 	net->xfrm.policy_idx_hmask = hmask;
3813 
3814 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
3815 		struct xfrm_policy_hash *htab;
3816 
3817 		net->xfrm.policy_count[dir] = 0;
3818 		net->xfrm.policy_count[XFRM_POLICY_MAX + dir] = 0;
3819 		INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
3820 
3821 		htab = &net->xfrm.policy_bydst[dir];
3822 		htab->table = xfrm_hash_alloc(sz);
3823 		if (!htab->table)
3824 			goto out_bydst;
3825 		htab->hmask = hmask;
3826 		htab->dbits4 = 32;
3827 		htab->sbits4 = 32;
3828 		htab->dbits6 = 128;
3829 		htab->sbits6 = 128;
3830 	}
3831 	net->xfrm.policy_hthresh.lbits4 = 32;
3832 	net->xfrm.policy_hthresh.rbits4 = 32;
3833 	net->xfrm.policy_hthresh.lbits6 = 128;
3834 	net->xfrm.policy_hthresh.rbits6 = 128;
3835 
3836 	seqlock_init(&net->xfrm.policy_hthresh.lock);
3837 
3838 	INIT_LIST_HEAD(&net->xfrm.policy_all);
3839 	INIT_LIST_HEAD(&net->xfrm.inexact_bins);
3840 	INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
3841 	INIT_WORK(&net->xfrm.policy_hthresh.work, xfrm_hash_rebuild);
3842 	return 0;
3843 
3844 out_bydst:
3845 	for (dir--; dir >= 0; dir--) {
3846 		struct xfrm_policy_hash *htab;
3847 
3848 		htab = &net->xfrm.policy_bydst[dir];
3849 		xfrm_hash_free(htab->table, sz);
3850 	}
3851 	xfrm_hash_free(net->xfrm.policy_byidx, sz);
3852 out_byidx:
3853 	return -ENOMEM;
3854 }
3855 
3856 static void xfrm_policy_fini(struct net *net)
3857 {
3858 	struct xfrm_pol_inexact_bin *b, *t;
3859 	unsigned int sz;
3860 	int dir;
3861 
3862 	flush_work(&net->xfrm.policy_hash_work);
3863 #ifdef CONFIG_XFRM_SUB_POLICY
3864 	xfrm_policy_flush(net, XFRM_POLICY_TYPE_SUB, false);
3865 #endif
3866 	xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, false);
3867 
3868 	WARN_ON(!list_empty(&net->xfrm.policy_all));
3869 
3870 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
3871 		struct xfrm_policy_hash *htab;
3872 
3873 		WARN_ON(!hlist_empty(&net->xfrm.policy_inexact[dir]));
3874 
3875 		htab = &net->xfrm.policy_bydst[dir];
3876 		sz = (htab->hmask + 1) * sizeof(struct hlist_head);
3877 		WARN_ON(!hlist_empty(htab->table));
3878 		xfrm_hash_free(htab->table, sz);
3879 	}
3880 
3881 	sz = (net->xfrm.policy_idx_hmask + 1) * sizeof(struct hlist_head);
3882 	WARN_ON(!hlist_empty(net->xfrm.policy_byidx));
3883 	xfrm_hash_free(net->xfrm.policy_byidx, sz);
3884 
3885 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
3886 	list_for_each_entry_safe(b, t, &net->xfrm.inexact_bins, inexact_bins)
3887 		__xfrm_policy_inexact_prune_bin(b, true);
3888 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
3889 }
3890 
3891 static int __net_init xfrm_net_init(struct net *net)
3892 {
3893 	int rv;
3894 
3895 	/* Initialize the per-net locks here */
3896 	spin_lock_init(&net->xfrm.xfrm_state_lock);
3897 	spin_lock_init(&net->xfrm.xfrm_policy_lock);
3898 	mutex_init(&net->xfrm.xfrm_cfg_mutex);
3899 
3900 	rv = xfrm_statistics_init(net);
3901 	if (rv < 0)
3902 		goto out_statistics;
3903 	rv = xfrm_state_init(net);
3904 	if (rv < 0)
3905 		goto out_state;
3906 	rv = xfrm_policy_init(net);
3907 	if (rv < 0)
3908 		goto out_policy;
3909 	rv = xfrm_sysctl_init(net);
3910 	if (rv < 0)
3911 		goto out_sysctl;
3912 
3913 	return 0;
3914 
3915 out_sysctl:
3916 	xfrm_policy_fini(net);
3917 out_policy:
3918 	xfrm_state_fini(net);
3919 out_state:
3920 	xfrm_statistics_fini(net);
3921 out_statistics:
3922 	return rv;
3923 }
3924 
3925 static void __net_exit xfrm_net_exit(struct net *net)
3926 {
3927 	xfrm_sysctl_fini(net);
3928 	xfrm_policy_fini(net);
3929 	xfrm_state_fini(net);
3930 	xfrm_statistics_fini(net);
3931 }
3932 
3933 static struct pernet_operations __net_initdata xfrm_net_ops = {
3934 	.init = xfrm_net_init,
3935 	.exit = xfrm_net_exit,
3936 };
3937 
3938 void __init xfrm_init(void)
3939 {
3940 	register_pernet_subsys(&xfrm_net_ops);
3941 	xfrm_dev_init();
3942 	seqcount_init(&xfrm_policy_hash_generation);
3943 	xfrm_input_init();
3944 
3945 	RCU_INIT_POINTER(xfrm_if_cb, NULL);
3946 	synchronize_rcu();
3947 }
3948 
3949 #ifdef CONFIG_AUDITSYSCALL
3950 static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
3951 					 struct audit_buffer *audit_buf)
3952 {
3953 	struct xfrm_sec_ctx *ctx = xp->security;
3954 	struct xfrm_selector *sel = &xp->selector;
3955 
3956 	if (ctx)
3957 		audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
3958 				 ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str);
3959 
3960 	switch (sel->family) {
3961 	case AF_INET:
3962 		audit_log_format(audit_buf, " src=%pI4", &sel->saddr.a4);
3963 		if (sel->prefixlen_s != 32)
3964 			audit_log_format(audit_buf, " src_prefixlen=%d",
3965 					 sel->prefixlen_s);
3966 		audit_log_format(audit_buf, " dst=%pI4", &sel->daddr.a4);
3967 		if (sel->prefixlen_d != 32)
3968 			audit_log_format(audit_buf, " dst_prefixlen=%d",
3969 					 sel->prefixlen_d);
3970 		break;
3971 	case AF_INET6:
3972 		audit_log_format(audit_buf, " src=%pI6", sel->saddr.a6);
3973 		if (sel->prefixlen_s != 128)
3974 			audit_log_format(audit_buf, " src_prefixlen=%d",
3975 					 sel->prefixlen_s);
3976 		audit_log_format(audit_buf, " dst=%pI6", sel->daddr.a6);
3977 		if (sel->prefixlen_d != 128)
3978 			audit_log_format(audit_buf, " dst_prefixlen=%d",
3979 					 sel->prefixlen_d);
3980 		break;
3981 	}
3982 }
3983 
3984 void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid)
3985 {
3986 	struct audit_buffer *audit_buf;
3987 
3988 	audit_buf = xfrm_audit_start("SPD-add");
3989 	if (audit_buf == NULL)
3990 		return;
3991 	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
3992 	audit_log_format(audit_buf, " res=%u", result);
3993 	xfrm_audit_common_policyinfo(xp, audit_buf);
3994 	audit_log_end(audit_buf);
3995 }
3996 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
3997 
3998 void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
3999 			      bool task_valid)
4000 {
4001 	struct audit_buffer *audit_buf;
4002 
4003 	audit_buf = xfrm_audit_start("SPD-delete");
4004 	if (audit_buf == NULL)
4005 		return;
4006 	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
4007 	audit_log_format(audit_buf, " res=%u", result);
4008 	xfrm_audit_common_policyinfo(xp, audit_buf);
4009 	audit_log_end(audit_buf);
4010 }
4011 EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
4012 #endif
4013 
4014 #ifdef CONFIG_XFRM_MIGRATE
4015 static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp,
4016 					const struct xfrm_selector *sel_tgt)
4017 {
4018 	if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
4019 		if (sel_tgt->family == sel_cmp->family &&
4020 		    xfrm_addr_equal(&sel_tgt->daddr, &sel_cmp->daddr,
4021 				    sel_cmp->family) &&
4022 		    xfrm_addr_equal(&sel_tgt->saddr, &sel_cmp->saddr,
4023 				    sel_cmp->family) &&
4024 		    sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
4025 		    sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
4026 			return true;
4027 		}
4028 	} else {
4029 		if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
4030 			return true;
4031 		}
4032 	}
4033 	return false;
4034 }
4035 
4036 static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector *sel,
4037 						    u8 dir, u8 type, struct net *net)
4038 {
4039 	struct xfrm_policy *pol, *ret = NULL;
4040 	struct hlist_head *chain;
4041 	u32 priority = ~0U;
4042 
4043 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
4044 	chain = policy_hash_direct(net, &sel->daddr, &sel->saddr, sel->family, dir);
4045 	hlist_for_each_entry(pol, chain, bydst) {
4046 		if (xfrm_migrate_selector_match(sel, &pol->selector) &&
4047 		    pol->type == type) {
4048 			ret = pol;
4049 			priority = ret->priority;
4050 			break;
4051 		}
4052 	}
4053 	chain = &net->xfrm.policy_inexact[dir];
4054 	hlist_for_each_entry(pol, chain, bydst_inexact_list) {
4055 		if ((pol->priority >= priority) && ret)
4056 			break;
4057 
4058 		if (xfrm_migrate_selector_match(sel, &pol->selector) &&
4059 		    pol->type == type) {
4060 			ret = pol;
4061 			break;
4062 		}
4063 	}
4064 
4065 	xfrm_pol_hold(ret);
4066 
4067 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
4068 
4069 	return ret;
4070 }
4071 
4072 static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t)
4073 {
4074 	int match = 0;
4075 
4076 	if (t->mode == m->mode && t->id.proto == m->proto &&
4077 	    (m->reqid == 0 || t->reqid == m->reqid)) {
4078 		switch (t->mode) {
4079 		case XFRM_MODE_TUNNEL:
4080 		case XFRM_MODE_BEET:
4081 			if (xfrm_addr_equal(&t->id.daddr, &m->old_daddr,
4082 					    m->old_family) &&
4083 			    xfrm_addr_equal(&t->saddr, &m->old_saddr,
4084 					    m->old_family)) {
4085 				match = 1;
4086 			}
4087 			break;
4088 		case XFRM_MODE_TRANSPORT:
4089 			/* in case of transport mode, template does not store
4090 			   any IP addresses, hence we just compare mode and
4091 			   protocol */
4092 			match = 1;
4093 			break;
4094 		default:
4095 			break;
4096 		}
4097 	}
4098 	return match;
4099 }
4100 
4101 /* update endpoint address(es) of template(s) */
4102 static int xfrm_policy_migrate(struct xfrm_policy *pol,
4103 			       struct xfrm_migrate *m, int num_migrate)
4104 {
4105 	struct xfrm_migrate *mp;
4106 	int i, j, n = 0;
4107 
4108 	write_lock_bh(&pol->lock);
4109 	if (unlikely(pol->walk.dead)) {
4110 		/* target policy has been deleted */
4111 		write_unlock_bh(&pol->lock);
4112 		return -ENOENT;
4113 	}
4114 
4115 	for (i = 0; i < pol->xfrm_nr; i++) {
4116 		for (j = 0, mp = m; j < num_migrate; j++, mp++) {
4117 			if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
4118 				continue;
4119 			n++;
4120 			if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
4121 			    pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
4122 				continue;
4123 			/* update endpoints */
4124 			memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
4125 			       sizeof(pol->xfrm_vec[i].id.daddr));
4126 			memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
4127 			       sizeof(pol->xfrm_vec[i].saddr));
4128 			pol->xfrm_vec[i].encap_family = mp->new_family;
4129 			/* flush bundles */
4130 			atomic_inc(&pol->genid);
4131 		}
4132 	}
4133 
4134 	write_unlock_bh(&pol->lock);
4135 
4136 	if (!n)
4137 		return -ENODATA;
4138 
4139 	return 0;
4140 }
4141 
4142 static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate)
4143 {
4144 	int i, j;
4145 
4146 	if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
4147 		return -EINVAL;
4148 
4149 	for (i = 0; i < num_migrate; i++) {
4150 		if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
4151 		    xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
4152 			return -EINVAL;
4153 
4154 		/* check if there is any duplicated entry */
4155 		for (j = i + 1; j < num_migrate; j++) {
4156 			if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
4157 				    sizeof(m[i].old_daddr)) &&
4158 			    !memcmp(&m[i].old_saddr, &m[j].old_saddr,
4159 				    sizeof(m[i].old_saddr)) &&
4160 			    m[i].proto == m[j].proto &&
4161 			    m[i].mode == m[j].mode &&
4162 			    m[i].reqid == m[j].reqid &&
4163 			    m[i].old_family == m[j].old_family)
4164 				return -EINVAL;
4165 		}
4166 	}
4167 
4168 	return 0;
4169 }
4170 
4171 int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
4172 		 struct xfrm_migrate *m, int num_migrate,
4173 		 struct xfrm_kmaddress *k, struct net *net,
4174 		 struct xfrm_encap_tmpl *encap)
4175 {
4176 	int i, err, nx_cur = 0, nx_new = 0;
4177 	struct xfrm_policy *pol = NULL;
4178 	struct xfrm_state *x, *xc;
4179 	struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
4180 	struct xfrm_state *x_new[XFRM_MAX_DEPTH];
4181 	struct xfrm_migrate *mp;
4182 
4183 	/* Stage 0 - sanity checks */
4184 	if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
4185 		goto out;
4186 
4187 	if (dir >= XFRM_POLICY_MAX) {
4188 		err = -EINVAL;
4189 		goto out;
4190 	}
4191 
4192 	/* Stage 1 - find policy */
4193 	if ((pol = xfrm_migrate_policy_find(sel, dir, type, net)) == NULL) {
4194 		err = -ENOENT;
4195 		goto out;
4196 	}
4197 
4198 	/* Stage 2 - find and update state(s) */
4199 	for (i = 0, mp = m; i < num_migrate; i++, mp++) {
4200 		if ((x = xfrm_migrate_state_find(mp, net))) {
4201 			x_cur[nx_cur] = x;
4202 			nx_cur++;
4203 			xc = xfrm_state_migrate(x, mp, encap);
4204 			if (xc) {
4205 				x_new[nx_new] = xc;
4206 				nx_new++;
4207 			} else {
4208 				err = -ENODATA;
4209 				goto restore_state;
4210 			}
4211 		}
4212 	}
4213 
4214 	/* Stage 3 - update policy */
4215 	if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
4216 		goto restore_state;
4217 
4218 	/* Stage 4 - delete old state(s) */
4219 	if (nx_cur) {
4220 		xfrm_states_put(x_cur, nx_cur);
4221 		xfrm_states_delete(x_cur, nx_cur);
4222 	}
4223 
4224 	/* Stage 5 - announce */
4225 	km_migrate(sel, dir, type, m, num_migrate, k, encap);
4226 
4227 	xfrm_pol_put(pol);
4228 
4229 	return 0;
4230 out:
4231 	return err;
4232 
4233 restore_state:
4234 	if (pol)
4235 		xfrm_pol_put(pol);
4236 	if (nx_cur)
4237 		xfrm_states_put(x_cur, nx_cur);
4238 	if (nx_new)
4239 		xfrm_states_delete(x_new, nx_new);
4240 
4241 	return err;
4242 }
4243 EXPORT_SYMBOL(xfrm_migrate);
4244 #endif
4245