xref: /linux/net/xfrm/xfrm_policy.c (revision 3f41368fbfe1b3d5922d317fe1a0a0cab6846802)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * xfrm_policy.c
4  *
5  * Changes:
6  *	Mitsuru KANDA @USAGI
7  * 	Kazunori MIYAZAWA @USAGI
8  * 	Kunihiro Ishiguro <kunihiro@ipinfusion.com>
9  * 		IPv6 support
10  * 	Kazunori MIYAZAWA @USAGI
11  * 	YOSHIFUJI Hideaki
12  * 		Split up af-specific portion
13  *	Derek Atkins <derek@ihtfp.com>		Add the post_input processor
14  *
15  */
16 
17 #include <linux/err.h>
18 #include <linux/slab.h>
19 #include <linux/kmod.h>
20 #include <linux/list.h>
21 #include <linux/spinlock.h>
22 #include <linux/workqueue.h>
23 #include <linux/notifier.h>
24 #include <linux/netdevice.h>
25 #include <linux/netfilter.h>
26 #include <linux/module.h>
27 #include <linux/cache.h>
28 #include <linux/cpu.h>
29 #include <linux/audit.h>
30 #include <linux/rhashtable.h>
31 #include <linux/if_tunnel.h>
32 #include <linux/icmp.h>
33 #include <net/dst.h>
34 #include <net/flow.h>
35 #include <net/inet_ecn.h>
36 #include <net/xfrm.h>
37 #include <net/ip.h>
38 #include <net/gre.h>
39 #if IS_ENABLED(CONFIG_IPV6_MIP6)
40 #include <net/mip6.h>
41 #endif
42 #ifdef CONFIG_XFRM_STATISTICS
43 #include <net/snmp.h>
44 #endif
45 #ifdef CONFIG_XFRM_ESPINTCP
46 #include <net/espintcp.h>
47 #endif
48 
49 #include "xfrm_hash.h"
50 
51 #define XFRM_QUEUE_TMO_MIN ((unsigned)(HZ/10))
52 #define XFRM_QUEUE_TMO_MAX ((unsigned)(60*HZ))
53 #define XFRM_MAX_QUEUE_LEN	100
54 
55 struct xfrm_flo {
56 	struct dst_entry *dst_orig;
57 	u8 flags;
58 };
59 
60 /* prefixes smaller than this are stored in lists, not trees. */
61 #define INEXACT_PREFIXLEN_IPV4	16
62 #define INEXACT_PREFIXLEN_IPV6	48
63 
64 struct xfrm_pol_inexact_node {
65 	struct rb_node node;
66 	union {
67 		xfrm_address_t addr;
68 		struct rcu_head rcu;
69 	};
70 	u8 prefixlen;
71 
72 	struct rb_root root;
73 
74 	/* the policies matching this node, can be empty list */
75 	struct hlist_head hhead;
76 };
77 
78 /* xfrm inexact policy search tree:
79  * xfrm_pol_inexact_bin = hash(dir,type,family,if_id);
80  *  |
81  * +---- root_d: sorted by daddr:prefix
82  * |                 |
83  * |        xfrm_pol_inexact_node
84  * |                 |
85  * |                 +- root: sorted by saddr/prefix
86  * |                 |              |
87  * |                 |         xfrm_pol_inexact_node
88  * |                 |              |
89  * |                 |              + root: unused
90  * |                 |              |
91  * |                 |              + hhead: saddr:daddr policies
92  * |                 |
93  * |                 +- coarse policies and all any:daddr policies
94  * |
95  * +---- root_s: sorted by saddr:prefix
96  * |                 |
97  * |        xfrm_pol_inexact_node
98  * |                 |
99  * |                 + root: unused
100  * |                 |
101  * |                 + hhead: saddr:any policies
102  * |
103  * +---- coarse policies and all any:any policies
104  *
105  * Lookups return four candidate lists:
106  * 1. any:any list from top-level xfrm_pol_inexact_bin
107  * 2. any:daddr list from daddr tree
108  * 3. saddr:daddr list from 2nd level daddr tree
109  * 4. saddr:any list from saddr tree
110  *
111  * This result set then needs to be searched for the policy with
112  * the lowest priority.  If two results have same prio, youngest one wins.
113  */
114 
115 struct xfrm_pol_inexact_key {
116 	possible_net_t net;
117 	u32 if_id;
118 	u16 family;
119 	u8 dir, type;
120 };
121 
122 struct xfrm_pol_inexact_bin {
123 	struct xfrm_pol_inexact_key k;
124 	struct rhash_head head;
125 	/* list containing '*:*' policies */
126 	struct hlist_head hhead;
127 
128 	seqcount_spinlock_t count;
129 	/* tree sorted by daddr/prefix */
130 	struct rb_root root_d;
131 
132 	/* tree sorted by saddr/prefix */
133 	struct rb_root root_s;
134 
135 	/* slow path below */
136 	struct list_head inexact_bins;
137 	struct rcu_head rcu;
138 };
139 
140 enum xfrm_pol_inexact_candidate_type {
141 	XFRM_POL_CAND_BOTH,
142 	XFRM_POL_CAND_SADDR,
143 	XFRM_POL_CAND_DADDR,
144 	XFRM_POL_CAND_ANY,
145 
146 	XFRM_POL_CAND_MAX,
147 };
148 
149 struct xfrm_pol_inexact_candidates {
150 	struct hlist_head *res[XFRM_POL_CAND_MAX];
151 };
152 
153 struct xfrm_flow_keys {
154 	struct flow_dissector_key_basic basic;
155 	struct flow_dissector_key_control control;
156 	union {
157 		struct flow_dissector_key_ipv4_addrs ipv4;
158 		struct flow_dissector_key_ipv6_addrs ipv6;
159 	} addrs;
160 	struct flow_dissector_key_ip ip;
161 	struct flow_dissector_key_icmp icmp;
162 	struct flow_dissector_key_ports ports;
163 	struct flow_dissector_key_keyid gre;
164 };
165 
166 static struct flow_dissector xfrm_session_dissector __ro_after_init;
167 
168 static DEFINE_SPINLOCK(xfrm_if_cb_lock);
169 static struct xfrm_if_cb const __rcu *xfrm_if_cb __read_mostly;
170 
171 static DEFINE_SPINLOCK(xfrm_policy_afinfo_lock);
172 static struct xfrm_policy_afinfo const __rcu *xfrm_policy_afinfo[AF_INET6 + 1]
173 						__read_mostly;
174 
175 static struct kmem_cache *xfrm_dst_cache __ro_after_init;
176 
177 static struct rhashtable xfrm_policy_inexact_table;
178 static const struct rhashtable_params xfrm_pol_inexact_params;
179 
180 static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr);
181 static int stale_bundle(struct dst_entry *dst);
182 static int xfrm_bundle_ok(struct xfrm_dst *xdst);
183 static void xfrm_policy_queue_process(struct timer_list *t);
184 
185 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir);
186 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
187 						int dir);
188 
189 static struct xfrm_pol_inexact_bin *
190 xfrm_policy_inexact_lookup(struct net *net, u8 type, u16 family, u8 dir,
191 			   u32 if_id);
192 
193 static struct xfrm_pol_inexact_bin *
194 xfrm_policy_inexact_lookup_rcu(struct net *net,
195 			       u8 type, u16 family, u8 dir, u32 if_id);
196 static struct xfrm_policy *
197 xfrm_policy_insert_list(struct hlist_head *chain, struct xfrm_policy *policy,
198 			bool excl);
199 static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
200 					    struct xfrm_policy *policy);
201 
202 static bool
203 xfrm_policy_find_inexact_candidates(struct xfrm_pol_inexact_candidates *cand,
204 				    struct xfrm_pol_inexact_bin *b,
205 				    const xfrm_address_t *saddr,
206 				    const xfrm_address_t *daddr);
207 
208 static inline bool xfrm_pol_hold_rcu(struct xfrm_policy *policy)
209 {
210 	return refcount_inc_not_zero(&policy->refcnt);
211 }
212 
213 static inline bool
214 __xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
215 {
216 	const struct flowi4 *fl4 = &fl->u.ip4;
217 
218 	return  addr4_match(fl4->daddr, sel->daddr.a4, sel->prefixlen_d) &&
219 		addr4_match(fl4->saddr, sel->saddr.a4, sel->prefixlen_s) &&
220 		!((xfrm_flowi_dport(fl, &fl4->uli) ^ sel->dport) & sel->dport_mask) &&
221 		!((xfrm_flowi_sport(fl, &fl4->uli) ^ sel->sport) & sel->sport_mask) &&
222 		(fl4->flowi4_proto == sel->proto || !sel->proto) &&
223 		(fl4->flowi4_oif == sel->ifindex || !sel->ifindex);
224 }
225 
226 static inline bool
227 __xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
228 {
229 	const struct flowi6 *fl6 = &fl->u.ip6;
230 
231 	return  addr_match(&fl6->daddr, &sel->daddr, sel->prefixlen_d) &&
232 		addr_match(&fl6->saddr, &sel->saddr, sel->prefixlen_s) &&
233 		!((xfrm_flowi_dport(fl, &fl6->uli) ^ sel->dport) & sel->dport_mask) &&
234 		!((xfrm_flowi_sport(fl, &fl6->uli) ^ sel->sport) & sel->sport_mask) &&
235 		(fl6->flowi6_proto == sel->proto || !sel->proto) &&
236 		(fl6->flowi6_oif == sel->ifindex || !sel->ifindex);
237 }
238 
239 bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl,
240 			 unsigned short family)
241 {
242 	switch (family) {
243 	case AF_INET:
244 		return __xfrm4_selector_match(sel, fl);
245 	case AF_INET6:
246 		return __xfrm6_selector_match(sel, fl);
247 	}
248 	return false;
249 }
250 
251 static const struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
252 {
253 	const struct xfrm_policy_afinfo *afinfo;
254 
255 	if (unlikely(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
256 		return NULL;
257 	rcu_read_lock();
258 	afinfo = rcu_dereference(xfrm_policy_afinfo[family]);
259 	if (unlikely(!afinfo))
260 		rcu_read_unlock();
261 	return afinfo;
262 }
263 
264 /* Called with rcu_read_lock(). */
265 static const struct xfrm_if_cb *xfrm_if_get_cb(void)
266 {
267 	return rcu_dereference(xfrm_if_cb);
268 }
269 
270 struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos, int oif,
271 				    const xfrm_address_t *saddr,
272 				    const xfrm_address_t *daddr,
273 				    int family, u32 mark)
274 {
275 	const struct xfrm_policy_afinfo *afinfo;
276 	struct dst_entry *dst;
277 
278 	afinfo = xfrm_policy_get_afinfo(family);
279 	if (unlikely(afinfo == NULL))
280 		return ERR_PTR(-EAFNOSUPPORT);
281 
282 	dst = afinfo->dst_lookup(net, tos, oif, saddr, daddr, mark);
283 
284 	rcu_read_unlock();
285 
286 	return dst;
287 }
288 EXPORT_SYMBOL(__xfrm_dst_lookup);
289 
290 static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x,
291 						int tos, int oif,
292 						xfrm_address_t *prev_saddr,
293 						xfrm_address_t *prev_daddr,
294 						int family, u32 mark)
295 {
296 	struct net *net = xs_net(x);
297 	xfrm_address_t *saddr = &x->props.saddr;
298 	xfrm_address_t *daddr = &x->id.daddr;
299 	struct dst_entry *dst;
300 
301 	if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) {
302 		saddr = x->coaddr;
303 		daddr = prev_daddr;
304 	}
305 	if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) {
306 		saddr = prev_saddr;
307 		daddr = x->coaddr;
308 	}
309 
310 	dst = __xfrm_dst_lookup(net, tos, oif, saddr, daddr, family, mark);
311 
312 	if (!IS_ERR(dst)) {
313 		if (prev_saddr != saddr)
314 			memcpy(prev_saddr, saddr,  sizeof(*prev_saddr));
315 		if (prev_daddr != daddr)
316 			memcpy(prev_daddr, daddr,  sizeof(*prev_daddr));
317 	}
318 
319 	return dst;
320 }
321 
322 static inline unsigned long make_jiffies(long secs)
323 {
324 	if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
325 		return MAX_SCHEDULE_TIMEOUT-1;
326 	else
327 		return secs*HZ;
328 }
329 
330 static void xfrm_policy_timer(struct timer_list *t)
331 {
332 	struct xfrm_policy *xp = from_timer(xp, t, timer);
333 	time64_t now = ktime_get_real_seconds();
334 	time64_t next = TIME64_MAX;
335 	int warn = 0;
336 	int dir;
337 
338 	read_lock(&xp->lock);
339 
340 	if (unlikely(xp->walk.dead))
341 		goto out;
342 
343 	dir = xfrm_policy_id2dir(xp->index);
344 
345 	if (xp->lft.hard_add_expires_seconds) {
346 		time64_t tmo = xp->lft.hard_add_expires_seconds +
347 			xp->curlft.add_time - now;
348 		if (tmo <= 0)
349 			goto expired;
350 		if (tmo < next)
351 			next = tmo;
352 	}
353 	if (xp->lft.hard_use_expires_seconds) {
354 		time64_t tmo = xp->lft.hard_use_expires_seconds +
355 			(READ_ONCE(xp->curlft.use_time) ? : xp->curlft.add_time) - now;
356 		if (tmo <= 0)
357 			goto expired;
358 		if (tmo < next)
359 			next = tmo;
360 	}
361 	if (xp->lft.soft_add_expires_seconds) {
362 		time64_t tmo = xp->lft.soft_add_expires_seconds +
363 			xp->curlft.add_time - now;
364 		if (tmo <= 0) {
365 			warn = 1;
366 			tmo = XFRM_KM_TIMEOUT;
367 		}
368 		if (tmo < next)
369 			next = tmo;
370 	}
371 	if (xp->lft.soft_use_expires_seconds) {
372 		time64_t tmo = xp->lft.soft_use_expires_seconds +
373 			(READ_ONCE(xp->curlft.use_time) ? : xp->curlft.add_time) - now;
374 		if (tmo <= 0) {
375 			warn = 1;
376 			tmo = XFRM_KM_TIMEOUT;
377 		}
378 		if (tmo < next)
379 			next = tmo;
380 	}
381 
382 	if (warn)
383 		km_policy_expired(xp, dir, 0, 0);
384 	if (next != TIME64_MAX &&
385 	    !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
386 		xfrm_pol_hold(xp);
387 
388 out:
389 	read_unlock(&xp->lock);
390 	xfrm_pol_put(xp);
391 	return;
392 
393 expired:
394 	read_unlock(&xp->lock);
395 	if (!xfrm_policy_delete(xp, dir))
396 		km_policy_expired(xp, dir, 1, 0);
397 	xfrm_pol_put(xp);
398 }
399 
400 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
401  * SPD calls.
402  */
403 
404 struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
405 {
406 	struct xfrm_policy *policy;
407 
408 	policy = kzalloc(sizeof(struct xfrm_policy), gfp);
409 
410 	if (policy) {
411 		write_pnet(&policy->xp_net, net);
412 		INIT_LIST_HEAD(&policy->walk.all);
413 		INIT_HLIST_NODE(&policy->bydst_inexact_list);
414 		INIT_HLIST_NODE(&policy->bydst);
415 		INIT_HLIST_NODE(&policy->byidx);
416 		rwlock_init(&policy->lock);
417 		refcount_set(&policy->refcnt, 1);
418 		skb_queue_head_init(&policy->polq.hold_queue);
419 		timer_setup(&policy->timer, xfrm_policy_timer, 0);
420 		timer_setup(&policy->polq.hold_timer,
421 			    xfrm_policy_queue_process, 0);
422 	}
423 	return policy;
424 }
425 EXPORT_SYMBOL(xfrm_policy_alloc);
426 
427 static void xfrm_policy_destroy_rcu(struct rcu_head *head)
428 {
429 	struct xfrm_policy *policy = container_of(head, struct xfrm_policy, rcu);
430 
431 	security_xfrm_policy_free(policy->security);
432 	kfree(policy);
433 }
434 
435 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
436 
437 void xfrm_policy_destroy(struct xfrm_policy *policy)
438 {
439 	BUG_ON(!policy->walk.dead);
440 
441 	if (del_timer(&policy->timer) || del_timer(&policy->polq.hold_timer))
442 		BUG();
443 
444 	xfrm_dev_policy_free(policy);
445 	call_rcu(&policy->rcu, xfrm_policy_destroy_rcu);
446 }
447 EXPORT_SYMBOL(xfrm_policy_destroy);
448 
449 /* Rule must be locked. Release descendant resources, announce
450  * entry dead. The rule must be unlinked from lists to the moment.
451  */
452 
453 static void xfrm_policy_kill(struct xfrm_policy *policy)
454 {
455 	write_lock_bh(&policy->lock);
456 	policy->walk.dead = 1;
457 	write_unlock_bh(&policy->lock);
458 
459 	atomic_inc(&policy->genid);
460 
461 	if (del_timer(&policy->polq.hold_timer))
462 		xfrm_pol_put(policy);
463 	skb_queue_purge(&policy->polq.hold_queue);
464 
465 	if (del_timer(&policy->timer))
466 		xfrm_pol_put(policy);
467 
468 	xfrm_pol_put(policy);
469 }
470 
471 static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
472 
473 static inline unsigned int idx_hash(struct net *net, u32 index)
474 {
475 	return __idx_hash(index, net->xfrm.policy_idx_hmask);
476 }
477 
478 /* calculate policy hash thresholds */
479 static void __get_hash_thresh(struct net *net,
480 			      unsigned short family, int dir,
481 			      u8 *dbits, u8 *sbits)
482 {
483 	switch (family) {
484 	case AF_INET:
485 		*dbits = net->xfrm.policy_bydst[dir].dbits4;
486 		*sbits = net->xfrm.policy_bydst[dir].sbits4;
487 		break;
488 
489 	case AF_INET6:
490 		*dbits = net->xfrm.policy_bydst[dir].dbits6;
491 		*sbits = net->xfrm.policy_bydst[dir].sbits6;
492 		break;
493 
494 	default:
495 		*dbits = 0;
496 		*sbits = 0;
497 	}
498 }
499 
500 static struct hlist_head *policy_hash_bysel(struct net *net,
501 					    const struct xfrm_selector *sel,
502 					    unsigned short family, int dir)
503 {
504 	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
505 	unsigned int hash;
506 	u8 dbits;
507 	u8 sbits;
508 
509 	__get_hash_thresh(net, family, dir, &dbits, &sbits);
510 	hash = __sel_hash(sel, family, hmask, dbits, sbits);
511 
512 	if (hash == hmask + 1)
513 		return NULL;
514 
515 	return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
516 		     lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
517 }
518 
519 static struct hlist_head *policy_hash_direct(struct net *net,
520 					     const xfrm_address_t *daddr,
521 					     const xfrm_address_t *saddr,
522 					     unsigned short family, int dir)
523 {
524 	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
525 	unsigned int hash;
526 	u8 dbits;
527 	u8 sbits;
528 
529 	__get_hash_thresh(net, family, dir, &dbits, &sbits);
530 	hash = __addr_hash(daddr, saddr, family, hmask, dbits, sbits);
531 
532 	return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
533 		     lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
534 }
535 
536 static void xfrm_dst_hash_transfer(struct net *net,
537 				   struct hlist_head *list,
538 				   struct hlist_head *ndsttable,
539 				   unsigned int nhashmask,
540 				   int dir)
541 {
542 	struct hlist_node *tmp, *entry0 = NULL;
543 	struct xfrm_policy *pol;
544 	unsigned int h0 = 0;
545 	u8 dbits;
546 	u8 sbits;
547 
548 redo:
549 	hlist_for_each_entry_safe(pol, tmp, list, bydst) {
550 		unsigned int h;
551 
552 		__get_hash_thresh(net, pol->family, dir, &dbits, &sbits);
553 		h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
554 				pol->family, nhashmask, dbits, sbits);
555 		if (!entry0 || pol->xdo.type == XFRM_DEV_OFFLOAD_PACKET) {
556 			hlist_del_rcu(&pol->bydst);
557 			hlist_add_head_rcu(&pol->bydst, ndsttable + h);
558 			h0 = h;
559 		} else {
560 			if (h != h0)
561 				continue;
562 			hlist_del_rcu(&pol->bydst);
563 			hlist_add_behind_rcu(&pol->bydst, entry0);
564 		}
565 		entry0 = &pol->bydst;
566 	}
567 	if (!hlist_empty(list)) {
568 		entry0 = NULL;
569 		goto redo;
570 	}
571 }
572 
573 static void xfrm_idx_hash_transfer(struct hlist_head *list,
574 				   struct hlist_head *nidxtable,
575 				   unsigned int nhashmask)
576 {
577 	struct hlist_node *tmp;
578 	struct xfrm_policy *pol;
579 
580 	hlist_for_each_entry_safe(pol, tmp, list, byidx) {
581 		unsigned int h;
582 
583 		h = __idx_hash(pol->index, nhashmask);
584 		hlist_add_head(&pol->byidx, nidxtable+h);
585 	}
586 }
587 
588 static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
589 {
590 	return ((old_hmask + 1) << 1) - 1;
591 }
592 
593 static void xfrm_bydst_resize(struct net *net, int dir)
594 {
595 	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
596 	unsigned int nhashmask = xfrm_new_hash_mask(hmask);
597 	unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
598 	struct hlist_head *ndst = xfrm_hash_alloc(nsize);
599 	struct hlist_head *odst;
600 	int i;
601 
602 	if (!ndst)
603 		return;
604 
605 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
606 	write_seqcount_begin(&net->xfrm.xfrm_policy_hash_generation);
607 
608 	odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
609 				lockdep_is_held(&net->xfrm.xfrm_policy_lock));
610 
611 	for (i = hmask; i >= 0; i--)
612 		xfrm_dst_hash_transfer(net, odst + i, ndst, nhashmask, dir);
613 
614 	rcu_assign_pointer(net->xfrm.policy_bydst[dir].table, ndst);
615 	net->xfrm.policy_bydst[dir].hmask = nhashmask;
616 
617 	write_seqcount_end(&net->xfrm.xfrm_policy_hash_generation);
618 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
619 
620 	synchronize_rcu();
621 
622 	xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
623 }
624 
625 static void xfrm_byidx_resize(struct net *net)
626 {
627 	unsigned int hmask = net->xfrm.policy_idx_hmask;
628 	unsigned int nhashmask = xfrm_new_hash_mask(hmask);
629 	unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
630 	struct hlist_head *oidx = net->xfrm.policy_byidx;
631 	struct hlist_head *nidx = xfrm_hash_alloc(nsize);
632 	int i;
633 
634 	if (!nidx)
635 		return;
636 
637 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
638 
639 	for (i = hmask; i >= 0; i--)
640 		xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
641 
642 	net->xfrm.policy_byidx = nidx;
643 	net->xfrm.policy_idx_hmask = nhashmask;
644 
645 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
646 
647 	xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
648 }
649 
650 static inline int xfrm_bydst_should_resize(struct net *net, int dir, int *total)
651 {
652 	unsigned int cnt = net->xfrm.policy_count[dir];
653 	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
654 
655 	if (total)
656 		*total += cnt;
657 
658 	if ((hmask + 1) < xfrm_policy_hashmax &&
659 	    cnt > hmask)
660 		return 1;
661 
662 	return 0;
663 }
664 
665 static inline int xfrm_byidx_should_resize(struct net *net, int total)
666 {
667 	unsigned int hmask = net->xfrm.policy_idx_hmask;
668 
669 	if ((hmask + 1) < xfrm_policy_hashmax &&
670 	    total > hmask)
671 		return 1;
672 
673 	return 0;
674 }
675 
676 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
677 {
678 	si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
679 	si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
680 	si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
681 	si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
682 	si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
683 	si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
684 	si->spdhcnt = net->xfrm.policy_idx_hmask;
685 	si->spdhmcnt = xfrm_policy_hashmax;
686 }
687 EXPORT_SYMBOL(xfrm_spd_getinfo);
688 
689 static DEFINE_MUTEX(hash_resize_mutex);
690 static void xfrm_hash_resize(struct work_struct *work)
691 {
692 	struct net *net = container_of(work, struct net, xfrm.policy_hash_work);
693 	int dir, total;
694 
695 	mutex_lock(&hash_resize_mutex);
696 
697 	total = 0;
698 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
699 		if (xfrm_bydst_should_resize(net, dir, &total))
700 			xfrm_bydst_resize(net, dir);
701 	}
702 	if (xfrm_byidx_should_resize(net, total))
703 		xfrm_byidx_resize(net);
704 
705 	mutex_unlock(&hash_resize_mutex);
706 }
707 
708 /* Make sure *pol can be inserted into fastbin.
709  * Useful to check that later insert requests will be successful
710  * (provided xfrm_policy_lock is held throughout).
711  */
712 static struct xfrm_pol_inexact_bin *
713 xfrm_policy_inexact_alloc_bin(const struct xfrm_policy *pol, u8 dir)
714 {
715 	struct xfrm_pol_inexact_bin *bin, *prev;
716 	struct xfrm_pol_inexact_key k = {
717 		.family = pol->family,
718 		.type = pol->type,
719 		.dir = dir,
720 		.if_id = pol->if_id,
721 	};
722 	struct net *net = xp_net(pol);
723 
724 	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
725 
726 	write_pnet(&k.net, net);
727 	bin = rhashtable_lookup_fast(&xfrm_policy_inexact_table, &k,
728 				     xfrm_pol_inexact_params);
729 	if (bin)
730 		return bin;
731 
732 	bin = kzalloc(sizeof(*bin), GFP_ATOMIC);
733 	if (!bin)
734 		return NULL;
735 
736 	bin->k = k;
737 	INIT_HLIST_HEAD(&bin->hhead);
738 	bin->root_d = RB_ROOT;
739 	bin->root_s = RB_ROOT;
740 	seqcount_spinlock_init(&bin->count, &net->xfrm.xfrm_policy_lock);
741 
742 	prev = rhashtable_lookup_get_insert_key(&xfrm_policy_inexact_table,
743 						&bin->k, &bin->head,
744 						xfrm_pol_inexact_params);
745 	if (!prev) {
746 		list_add(&bin->inexact_bins, &net->xfrm.inexact_bins);
747 		return bin;
748 	}
749 
750 	kfree(bin);
751 
752 	return IS_ERR(prev) ? NULL : prev;
753 }
754 
755 static bool xfrm_pol_inexact_addr_use_any_list(const xfrm_address_t *addr,
756 					       int family, u8 prefixlen)
757 {
758 	if (xfrm_addr_any(addr, family))
759 		return true;
760 
761 	if (family == AF_INET6 && prefixlen < INEXACT_PREFIXLEN_IPV6)
762 		return true;
763 
764 	if (family == AF_INET && prefixlen < INEXACT_PREFIXLEN_IPV4)
765 		return true;
766 
767 	return false;
768 }
769 
770 static bool
771 xfrm_policy_inexact_insert_use_any_list(const struct xfrm_policy *policy)
772 {
773 	const xfrm_address_t *addr;
774 	bool saddr_any, daddr_any;
775 	u8 prefixlen;
776 
777 	addr = &policy->selector.saddr;
778 	prefixlen = policy->selector.prefixlen_s;
779 
780 	saddr_any = xfrm_pol_inexact_addr_use_any_list(addr,
781 						       policy->family,
782 						       prefixlen);
783 	addr = &policy->selector.daddr;
784 	prefixlen = policy->selector.prefixlen_d;
785 	daddr_any = xfrm_pol_inexact_addr_use_any_list(addr,
786 						       policy->family,
787 						       prefixlen);
788 	return saddr_any && daddr_any;
789 }
790 
791 static void xfrm_pol_inexact_node_init(struct xfrm_pol_inexact_node *node,
792 				       const xfrm_address_t *addr, u8 prefixlen)
793 {
794 	node->addr = *addr;
795 	node->prefixlen = prefixlen;
796 }
797 
798 static struct xfrm_pol_inexact_node *
799 xfrm_pol_inexact_node_alloc(const xfrm_address_t *addr, u8 prefixlen)
800 {
801 	struct xfrm_pol_inexact_node *node;
802 
803 	node = kzalloc(sizeof(*node), GFP_ATOMIC);
804 	if (node)
805 		xfrm_pol_inexact_node_init(node, addr, prefixlen);
806 
807 	return node;
808 }
809 
810 static int xfrm_policy_addr_delta(const xfrm_address_t *a,
811 				  const xfrm_address_t *b,
812 				  u8 prefixlen, u16 family)
813 {
814 	u32 ma, mb, mask;
815 	unsigned int pdw, pbi;
816 	int delta = 0;
817 
818 	switch (family) {
819 	case AF_INET:
820 		if (prefixlen == 0)
821 			return 0;
822 		mask = ~0U << (32 - prefixlen);
823 		ma = ntohl(a->a4) & mask;
824 		mb = ntohl(b->a4) & mask;
825 		if (ma < mb)
826 			delta = -1;
827 		else if (ma > mb)
828 			delta = 1;
829 		break;
830 	case AF_INET6:
831 		pdw = prefixlen >> 5;
832 		pbi = prefixlen & 0x1f;
833 
834 		if (pdw) {
835 			delta = memcmp(a->a6, b->a6, pdw << 2);
836 			if (delta)
837 				return delta;
838 		}
839 		if (pbi) {
840 			mask = ~0U << (32 - pbi);
841 			ma = ntohl(a->a6[pdw]) & mask;
842 			mb = ntohl(b->a6[pdw]) & mask;
843 			if (ma < mb)
844 				delta = -1;
845 			else if (ma > mb)
846 				delta = 1;
847 		}
848 		break;
849 	default:
850 		break;
851 	}
852 
853 	return delta;
854 }
855 
856 static void xfrm_policy_inexact_list_reinsert(struct net *net,
857 					      struct xfrm_pol_inexact_node *n,
858 					      u16 family)
859 {
860 	unsigned int matched_s, matched_d;
861 	struct xfrm_policy *policy, *p;
862 
863 	matched_s = 0;
864 	matched_d = 0;
865 
866 	list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
867 		struct hlist_node *newpos = NULL;
868 		bool matches_s, matches_d;
869 
870 		if (policy->walk.dead || !policy->bydst_reinsert)
871 			continue;
872 
873 		WARN_ON_ONCE(policy->family != family);
874 
875 		policy->bydst_reinsert = false;
876 		hlist_for_each_entry(p, &n->hhead, bydst) {
877 			if (policy->priority > p->priority)
878 				newpos = &p->bydst;
879 			else if (policy->priority == p->priority &&
880 				 policy->pos > p->pos)
881 				newpos = &p->bydst;
882 			else
883 				break;
884 		}
885 
886 		if (newpos && policy->xdo.type != XFRM_DEV_OFFLOAD_PACKET)
887 			hlist_add_behind_rcu(&policy->bydst, newpos);
888 		else
889 			hlist_add_head_rcu(&policy->bydst, &n->hhead);
890 
891 		/* paranoia checks follow.
892 		 * Check that the reinserted policy matches at least
893 		 * saddr or daddr for current node prefix.
894 		 *
895 		 * Matching both is fine, matching saddr in one policy
896 		 * (but not daddr) and then matching only daddr in another
897 		 * is a bug.
898 		 */
899 		matches_s = xfrm_policy_addr_delta(&policy->selector.saddr,
900 						   &n->addr,
901 						   n->prefixlen,
902 						   family) == 0;
903 		matches_d = xfrm_policy_addr_delta(&policy->selector.daddr,
904 						   &n->addr,
905 						   n->prefixlen,
906 						   family) == 0;
907 		if (matches_s && matches_d)
908 			continue;
909 
910 		WARN_ON_ONCE(!matches_s && !matches_d);
911 		if (matches_s)
912 			matched_s++;
913 		if (matches_d)
914 			matched_d++;
915 		WARN_ON_ONCE(matched_s && matched_d);
916 	}
917 }
918 
919 static void xfrm_policy_inexact_node_reinsert(struct net *net,
920 					      struct xfrm_pol_inexact_node *n,
921 					      struct rb_root *new,
922 					      u16 family)
923 {
924 	struct xfrm_pol_inexact_node *node;
925 	struct rb_node **p, *parent;
926 
927 	/* we should not have another subtree here */
928 	WARN_ON_ONCE(!RB_EMPTY_ROOT(&n->root));
929 restart:
930 	parent = NULL;
931 	p = &new->rb_node;
932 	while (*p) {
933 		u8 prefixlen;
934 		int delta;
935 
936 		parent = *p;
937 		node = rb_entry(*p, struct xfrm_pol_inexact_node, node);
938 
939 		prefixlen = min(node->prefixlen, n->prefixlen);
940 
941 		delta = xfrm_policy_addr_delta(&n->addr, &node->addr,
942 					       prefixlen, family);
943 		if (delta < 0) {
944 			p = &parent->rb_left;
945 		} else if (delta > 0) {
946 			p = &parent->rb_right;
947 		} else {
948 			bool same_prefixlen = node->prefixlen == n->prefixlen;
949 			struct xfrm_policy *tmp;
950 
951 			hlist_for_each_entry(tmp, &n->hhead, bydst) {
952 				tmp->bydst_reinsert = true;
953 				hlist_del_rcu(&tmp->bydst);
954 			}
955 
956 			node->prefixlen = prefixlen;
957 
958 			xfrm_policy_inexact_list_reinsert(net, node, family);
959 
960 			if (same_prefixlen) {
961 				kfree_rcu(n, rcu);
962 				return;
963 			}
964 
965 			rb_erase(*p, new);
966 			kfree_rcu(n, rcu);
967 			n = node;
968 			goto restart;
969 		}
970 	}
971 
972 	rb_link_node_rcu(&n->node, parent, p);
973 	rb_insert_color(&n->node, new);
974 }
975 
976 /* merge nodes v and n */
977 static void xfrm_policy_inexact_node_merge(struct net *net,
978 					   struct xfrm_pol_inexact_node *v,
979 					   struct xfrm_pol_inexact_node *n,
980 					   u16 family)
981 {
982 	struct xfrm_pol_inexact_node *node;
983 	struct xfrm_policy *tmp;
984 	struct rb_node *rnode;
985 
986 	/* To-be-merged node v has a subtree.
987 	 *
988 	 * Dismantle it and insert its nodes to n->root.
989 	 */
990 	while ((rnode = rb_first(&v->root)) != NULL) {
991 		node = rb_entry(rnode, struct xfrm_pol_inexact_node, node);
992 		rb_erase(&node->node, &v->root);
993 		xfrm_policy_inexact_node_reinsert(net, node, &n->root,
994 						  family);
995 	}
996 
997 	hlist_for_each_entry(tmp, &v->hhead, bydst) {
998 		tmp->bydst_reinsert = true;
999 		hlist_del_rcu(&tmp->bydst);
1000 	}
1001 
1002 	xfrm_policy_inexact_list_reinsert(net, n, family);
1003 }
1004 
1005 static struct xfrm_pol_inexact_node *
1006 xfrm_policy_inexact_insert_node(struct net *net,
1007 				struct rb_root *root,
1008 				xfrm_address_t *addr,
1009 				u16 family, u8 prefixlen, u8 dir)
1010 {
1011 	struct xfrm_pol_inexact_node *cached = NULL;
1012 	struct rb_node **p, *parent = NULL;
1013 	struct xfrm_pol_inexact_node *node;
1014 
1015 	p = &root->rb_node;
1016 	while (*p) {
1017 		int delta;
1018 
1019 		parent = *p;
1020 		node = rb_entry(*p, struct xfrm_pol_inexact_node, node);
1021 
1022 		delta = xfrm_policy_addr_delta(addr, &node->addr,
1023 					       node->prefixlen,
1024 					       family);
1025 		if (delta == 0 && prefixlen >= node->prefixlen) {
1026 			WARN_ON_ONCE(cached); /* ipsec policies got lost */
1027 			return node;
1028 		}
1029 
1030 		if (delta < 0)
1031 			p = &parent->rb_left;
1032 		else
1033 			p = &parent->rb_right;
1034 
1035 		if (prefixlen < node->prefixlen) {
1036 			delta = xfrm_policy_addr_delta(addr, &node->addr,
1037 						       prefixlen,
1038 						       family);
1039 			if (delta)
1040 				continue;
1041 
1042 			/* This node is a subnet of the new prefix. It needs
1043 			 * to be removed and re-inserted with the smaller
1044 			 * prefix and all nodes that are now also covered
1045 			 * by the reduced prefixlen.
1046 			 */
1047 			rb_erase(&node->node, root);
1048 
1049 			if (!cached) {
1050 				xfrm_pol_inexact_node_init(node, addr,
1051 							   prefixlen);
1052 				cached = node;
1053 			} else {
1054 				/* This node also falls within the new
1055 				 * prefixlen. Merge the to-be-reinserted
1056 				 * node and this one.
1057 				 */
1058 				xfrm_policy_inexact_node_merge(net, node,
1059 							       cached, family);
1060 				kfree_rcu(node, rcu);
1061 			}
1062 
1063 			/* restart */
1064 			p = &root->rb_node;
1065 			parent = NULL;
1066 		}
1067 	}
1068 
1069 	node = cached;
1070 	if (!node) {
1071 		node = xfrm_pol_inexact_node_alloc(addr, prefixlen);
1072 		if (!node)
1073 			return NULL;
1074 	}
1075 
1076 	rb_link_node_rcu(&node->node, parent, p);
1077 	rb_insert_color(&node->node, root);
1078 
1079 	return node;
1080 }
1081 
1082 static void xfrm_policy_inexact_gc_tree(struct rb_root *r, bool rm)
1083 {
1084 	struct xfrm_pol_inexact_node *node;
1085 	struct rb_node *rn = rb_first(r);
1086 
1087 	while (rn) {
1088 		node = rb_entry(rn, struct xfrm_pol_inexact_node, node);
1089 
1090 		xfrm_policy_inexact_gc_tree(&node->root, rm);
1091 		rn = rb_next(rn);
1092 
1093 		if (!hlist_empty(&node->hhead) || !RB_EMPTY_ROOT(&node->root)) {
1094 			WARN_ON_ONCE(rm);
1095 			continue;
1096 		}
1097 
1098 		rb_erase(&node->node, r);
1099 		kfree_rcu(node, rcu);
1100 	}
1101 }
1102 
1103 static void __xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin *b, bool net_exit)
1104 {
1105 	write_seqcount_begin(&b->count);
1106 	xfrm_policy_inexact_gc_tree(&b->root_d, net_exit);
1107 	xfrm_policy_inexact_gc_tree(&b->root_s, net_exit);
1108 	write_seqcount_end(&b->count);
1109 
1110 	if (!RB_EMPTY_ROOT(&b->root_d) || !RB_EMPTY_ROOT(&b->root_s) ||
1111 	    !hlist_empty(&b->hhead)) {
1112 		WARN_ON_ONCE(net_exit);
1113 		return;
1114 	}
1115 
1116 	if (rhashtable_remove_fast(&xfrm_policy_inexact_table, &b->head,
1117 				   xfrm_pol_inexact_params) == 0) {
1118 		list_del(&b->inexact_bins);
1119 		kfree_rcu(b, rcu);
1120 	}
1121 }
1122 
1123 static void xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin *b)
1124 {
1125 	struct net *net = read_pnet(&b->k.net);
1126 
1127 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1128 	__xfrm_policy_inexact_prune_bin(b, false);
1129 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1130 }
1131 
1132 static void __xfrm_policy_inexact_flush(struct net *net)
1133 {
1134 	struct xfrm_pol_inexact_bin *bin, *t;
1135 
1136 	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1137 
1138 	list_for_each_entry_safe(bin, t, &net->xfrm.inexact_bins, inexact_bins)
1139 		__xfrm_policy_inexact_prune_bin(bin, false);
1140 }
1141 
1142 static struct hlist_head *
1143 xfrm_policy_inexact_alloc_chain(struct xfrm_pol_inexact_bin *bin,
1144 				struct xfrm_policy *policy, u8 dir)
1145 {
1146 	struct xfrm_pol_inexact_node *n;
1147 	struct net *net;
1148 
1149 	net = xp_net(policy);
1150 	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1151 
1152 	if (xfrm_policy_inexact_insert_use_any_list(policy))
1153 		return &bin->hhead;
1154 
1155 	if (xfrm_pol_inexact_addr_use_any_list(&policy->selector.daddr,
1156 					       policy->family,
1157 					       policy->selector.prefixlen_d)) {
1158 		write_seqcount_begin(&bin->count);
1159 		n = xfrm_policy_inexact_insert_node(net,
1160 						    &bin->root_s,
1161 						    &policy->selector.saddr,
1162 						    policy->family,
1163 						    policy->selector.prefixlen_s,
1164 						    dir);
1165 		write_seqcount_end(&bin->count);
1166 		if (!n)
1167 			return NULL;
1168 
1169 		return &n->hhead;
1170 	}
1171 
1172 	/* daddr is fixed */
1173 	write_seqcount_begin(&bin->count);
1174 	n = xfrm_policy_inexact_insert_node(net,
1175 					    &bin->root_d,
1176 					    &policy->selector.daddr,
1177 					    policy->family,
1178 					    policy->selector.prefixlen_d, dir);
1179 	write_seqcount_end(&bin->count);
1180 	if (!n)
1181 		return NULL;
1182 
1183 	/* saddr is wildcard */
1184 	if (xfrm_pol_inexact_addr_use_any_list(&policy->selector.saddr,
1185 					       policy->family,
1186 					       policy->selector.prefixlen_s))
1187 		return &n->hhead;
1188 
1189 	write_seqcount_begin(&bin->count);
1190 	n = xfrm_policy_inexact_insert_node(net,
1191 					    &n->root,
1192 					    &policy->selector.saddr,
1193 					    policy->family,
1194 					    policy->selector.prefixlen_s, dir);
1195 	write_seqcount_end(&bin->count);
1196 	if (!n)
1197 		return NULL;
1198 
1199 	return &n->hhead;
1200 }
1201 
1202 static struct xfrm_policy *
1203 xfrm_policy_inexact_insert(struct xfrm_policy *policy, u8 dir, int excl)
1204 {
1205 	struct xfrm_pol_inexact_bin *bin;
1206 	struct xfrm_policy *delpol;
1207 	struct hlist_head *chain;
1208 	struct net *net;
1209 
1210 	bin = xfrm_policy_inexact_alloc_bin(policy, dir);
1211 	if (!bin)
1212 		return ERR_PTR(-ENOMEM);
1213 
1214 	net = xp_net(policy);
1215 	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1216 
1217 	chain = xfrm_policy_inexact_alloc_chain(bin, policy, dir);
1218 	if (!chain) {
1219 		__xfrm_policy_inexact_prune_bin(bin, false);
1220 		return ERR_PTR(-ENOMEM);
1221 	}
1222 
1223 	delpol = xfrm_policy_insert_list(chain, policy, excl);
1224 	if (delpol && excl) {
1225 		__xfrm_policy_inexact_prune_bin(bin, false);
1226 		return ERR_PTR(-EEXIST);
1227 	}
1228 
1229 	chain = &net->xfrm.policy_inexact[dir];
1230 	xfrm_policy_insert_inexact_list(chain, policy);
1231 
1232 	if (delpol)
1233 		__xfrm_policy_inexact_prune_bin(bin, false);
1234 
1235 	return delpol;
1236 }
1237 
1238 static void xfrm_hash_rebuild(struct work_struct *work)
1239 {
1240 	struct net *net = container_of(work, struct net,
1241 				       xfrm.policy_hthresh.work);
1242 	unsigned int hmask;
1243 	struct xfrm_policy *pol;
1244 	struct xfrm_policy *policy;
1245 	struct hlist_head *chain;
1246 	struct hlist_head *odst;
1247 	struct hlist_node *newpos;
1248 	int i;
1249 	int dir;
1250 	unsigned seq;
1251 	u8 lbits4, rbits4, lbits6, rbits6;
1252 
1253 	mutex_lock(&hash_resize_mutex);
1254 
1255 	/* read selector prefixlen thresholds */
1256 	do {
1257 		seq = read_seqbegin(&net->xfrm.policy_hthresh.lock);
1258 
1259 		lbits4 = net->xfrm.policy_hthresh.lbits4;
1260 		rbits4 = net->xfrm.policy_hthresh.rbits4;
1261 		lbits6 = net->xfrm.policy_hthresh.lbits6;
1262 		rbits6 = net->xfrm.policy_hthresh.rbits6;
1263 	} while (read_seqretry(&net->xfrm.policy_hthresh.lock, seq));
1264 
1265 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1266 	write_seqcount_begin(&net->xfrm.xfrm_policy_hash_generation);
1267 
1268 	/* make sure that we can insert the indirect policies again before
1269 	 * we start with destructive action.
1270 	 */
1271 	list_for_each_entry(policy, &net->xfrm.policy_all, walk.all) {
1272 		struct xfrm_pol_inexact_bin *bin;
1273 		u8 dbits, sbits;
1274 
1275 		if (policy->walk.dead)
1276 			continue;
1277 
1278 		dir = xfrm_policy_id2dir(policy->index);
1279 		if (dir >= XFRM_POLICY_MAX)
1280 			continue;
1281 
1282 		if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
1283 			if (policy->family == AF_INET) {
1284 				dbits = rbits4;
1285 				sbits = lbits4;
1286 			} else {
1287 				dbits = rbits6;
1288 				sbits = lbits6;
1289 			}
1290 		} else {
1291 			if (policy->family == AF_INET) {
1292 				dbits = lbits4;
1293 				sbits = rbits4;
1294 			} else {
1295 				dbits = lbits6;
1296 				sbits = rbits6;
1297 			}
1298 		}
1299 
1300 		if (policy->selector.prefixlen_d < dbits ||
1301 		    policy->selector.prefixlen_s < sbits)
1302 			continue;
1303 
1304 		bin = xfrm_policy_inexact_alloc_bin(policy, dir);
1305 		if (!bin)
1306 			goto out_unlock;
1307 
1308 		if (!xfrm_policy_inexact_alloc_chain(bin, policy, dir))
1309 			goto out_unlock;
1310 	}
1311 
1312 	/* reset the bydst and inexact table in all directions */
1313 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
1314 		struct hlist_node *n;
1315 
1316 		hlist_for_each_entry_safe(policy, n,
1317 					  &net->xfrm.policy_inexact[dir],
1318 					  bydst_inexact_list) {
1319 			hlist_del_rcu(&policy->bydst);
1320 			hlist_del_init(&policy->bydst_inexact_list);
1321 		}
1322 
1323 		hmask = net->xfrm.policy_bydst[dir].hmask;
1324 		odst = net->xfrm.policy_bydst[dir].table;
1325 		for (i = hmask; i >= 0; i--) {
1326 			hlist_for_each_entry_safe(policy, n, odst + i, bydst)
1327 				hlist_del_rcu(&policy->bydst);
1328 		}
1329 		if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
1330 			/* dir out => dst = remote, src = local */
1331 			net->xfrm.policy_bydst[dir].dbits4 = rbits4;
1332 			net->xfrm.policy_bydst[dir].sbits4 = lbits4;
1333 			net->xfrm.policy_bydst[dir].dbits6 = rbits6;
1334 			net->xfrm.policy_bydst[dir].sbits6 = lbits6;
1335 		} else {
1336 			/* dir in/fwd => dst = local, src = remote */
1337 			net->xfrm.policy_bydst[dir].dbits4 = lbits4;
1338 			net->xfrm.policy_bydst[dir].sbits4 = rbits4;
1339 			net->xfrm.policy_bydst[dir].dbits6 = lbits6;
1340 			net->xfrm.policy_bydst[dir].sbits6 = rbits6;
1341 		}
1342 	}
1343 
1344 	/* re-insert all policies by order of creation */
1345 	list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
1346 		if (policy->walk.dead)
1347 			continue;
1348 		dir = xfrm_policy_id2dir(policy->index);
1349 		if (dir >= XFRM_POLICY_MAX) {
1350 			/* skip socket policies */
1351 			continue;
1352 		}
1353 		newpos = NULL;
1354 		chain = policy_hash_bysel(net, &policy->selector,
1355 					  policy->family, dir);
1356 
1357 		if (!chain) {
1358 			void *p = xfrm_policy_inexact_insert(policy, dir, 0);
1359 
1360 			WARN_ONCE(IS_ERR(p), "reinsert: %ld\n", PTR_ERR(p));
1361 			continue;
1362 		}
1363 
1364 		hlist_for_each_entry(pol, chain, bydst) {
1365 			if (policy->priority >= pol->priority)
1366 				newpos = &pol->bydst;
1367 			else
1368 				break;
1369 		}
1370 		if (newpos && policy->xdo.type != XFRM_DEV_OFFLOAD_PACKET)
1371 			hlist_add_behind_rcu(&policy->bydst, newpos);
1372 		else
1373 			hlist_add_head_rcu(&policy->bydst, chain);
1374 	}
1375 
1376 out_unlock:
1377 	__xfrm_policy_inexact_flush(net);
1378 	write_seqcount_end(&net->xfrm.xfrm_policy_hash_generation);
1379 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1380 
1381 	mutex_unlock(&hash_resize_mutex);
1382 }
1383 
1384 void xfrm_policy_hash_rebuild(struct net *net)
1385 {
1386 	schedule_work(&net->xfrm.policy_hthresh.work);
1387 }
1388 EXPORT_SYMBOL(xfrm_policy_hash_rebuild);
1389 
1390 /* Generate new index... KAME seems to generate them ordered by cost
1391  * of an absolute inpredictability of ordering of rules. This will not pass. */
1392 static u32 xfrm_gen_index(struct net *net, int dir, u32 index)
1393 {
1394 	for (;;) {
1395 		struct hlist_head *list;
1396 		struct xfrm_policy *p;
1397 		u32 idx;
1398 		int found;
1399 
1400 		if (!index) {
1401 			idx = (net->xfrm.idx_generator | dir);
1402 			net->xfrm.idx_generator += 8;
1403 		} else {
1404 			idx = index;
1405 			index = 0;
1406 		}
1407 
1408 		if (idx == 0)
1409 			idx = 8;
1410 		list = net->xfrm.policy_byidx + idx_hash(net, idx);
1411 		found = 0;
1412 		hlist_for_each_entry(p, list, byidx) {
1413 			if (p->index == idx) {
1414 				found = 1;
1415 				break;
1416 			}
1417 		}
1418 		if (!found)
1419 			return idx;
1420 	}
1421 }
1422 
1423 static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
1424 {
1425 	u32 *p1 = (u32 *) s1;
1426 	u32 *p2 = (u32 *) s2;
1427 	int len = sizeof(struct xfrm_selector) / sizeof(u32);
1428 	int i;
1429 
1430 	for (i = 0; i < len; i++) {
1431 		if (p1[i] != p2[i])
1432 			return 1;
1433 	}
1434 
1435 	return 0;
1436 }
1437 
1438 static void xfrm_policy_requeue(struct xfrm_policy *old,
1439 				struct xfrm_policy *new)
1440 {
1441 	struct xfrm_policy_queue *pq = &old->polq;
1442 	struct sk_buff_head list;
1443 
1444 	if (skb_queue_empty(&pq->hold_queue))
1445 		return;
1446 
1447 	__skb_queue_head_init(&list);
1448 
1449 	spin_lock_bh(&pq->hold_queue.lock);
1450 	skb_queue_splice_init(&pq->hold_queue, &list);
1451 	if (del_timer(&pq->hold_timer))
1452 		xfrm_pol_put(old);
1453 	spin_unlock_bh(&pq->hold_queue.lock);
1454 
1455 	pq = &new->polq;
1456 
1457 	spin_lock_bh(&pq->hold_queue.lock);
1458 	skb_queue_splice(&list, &pq->hold_queue);
1459 	pq->timeout = XFRM_QUEUE_TMO_MIN;
1460 	if (!mod_timer(&pq->hold_timer, jiffies))
1461 		xfrm_pol_hold(new);
1462 	spin_unlock_bh(&pq->hold_queue.lock);
1463 }
1464 
1465 static inline bool xfrm_policy_mark_match(const struct xfrm_mark *mark,
1466 					  struct xfrm_policy *pol)
1467 {
1468 	return mark->v == pol->mark.v && mark->m == pol->mark.m;
1469 }
1470 
1471 static u32 xfrm_pol_bin_key(const void *data, u32 len, u32 seed)
1472 {
1473 	const struct xfrm_pol_inexact_key *k = data;
1474 	u32 a = k->type << 24 | k->dir << 16 | k->family;
1475 
1476 	return jhash_3words(a, k->if_id, net_hash_mix(read_pnet(&k->net)),
1477 			    seed);
1478 }
1479 
1480 static u32 xfrm_pol_bin_obj(const void *data, u32 len, u32 seed)
1481 {
1482 	const struct xfrm_pol_inexact_bin *b = data;
1483 
1484 	return xfrm_pol_bin_key(&b->k, 0, seed);
1485 }
1486 
1487 static int xfrm_pol_bin_cmp(struct rhashtable_compare_arg *arg,
1488 			    const void *ptr)
1489 {
1490 	const struct xfrm_pol_inexact_key *key = arg->key;
1491 	const struct xfrm_pol_inexact_bin *b = ptr;
1492 	int ret;
1493 
1494 	if (!net_eq(read_pnet(&b->k.net), read_pnet(&key->net)))
1495 		return -1;
1496 
1497 	ret = b->k.dir ^ key->dir;
1498 	if (ret)
1499 		return ret;
1500 
1501 	ret = b->k.type ^ key->type;
1502 	if (ret)
1503 		return ret;
1504 
1505 	ret = b->k.family ^ key->family;
1506 	if (ret)
1507 		return ret;
1508 
1509 	return b->k.if_id ^ key->if_id;
1510 }
1511 
1512 static const struct rhashtable_params xfrm_pol_inexact_params = {
1513 	.head_offset		= offsetof(struct xfrm_pol_inexact_bin, head),
1514 	.hashfn			= xfrm_pol_bin_key,
1515 	.obj_hashfn		= xfrm_pol_bin_obj,
1516 	.obj_cmpfn		= xfrm_pol_bin_cmp,
1517 	.automatic_shrinking	= true,
1518 };
1519 
1520 static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
1521 					    struct xfrm_policy *policy)
1522 {
1523 	struct xfrm_policy *pol, *delpol = NULL;
1524 	struct hlist_node *newpos = NULL;
1525 	int i = 0;
1526 
1527 	hlist_for_each_entry(pol, chain, bydst_inexact_list) {
1528 		if (pol->type == policy->type &&
1529 		    pol->if_id == policy->if_id &&
1530 		    !selector_cmp(&pol->selector, &policy->selector) &&
1531 		    xfrm_policy_mark_match(&policy->mark, pol) &&
1532 		    xfrm_sec_ctx_match(pol->security, policy->security) &&
1533 		    !WARN_ON(delpol)) {
1534 			delpol = pol;
1535 			if (policy->priority > pol->priority)
1536 				continue;
1537 		} else if (policy->priority >= pol->priority) {
1538 			newpos = &pol->bydst_inexact_list;
1539 			continue;
1540 		}
1541 		if (delpol)
1542 			break;
1543 	}
1544 
1545 	if (newpos && policy->xdo.type != XFRM_DEV_OFFLOAD_PACKET)
1546 		hlist_add_behind_rcu(&policy->bydst_inexact_list, newpos);
1547 	else
1548 		hlist_add_head_rcu(&policy->bydst_inexact_list, chain);
1549 
1550 	hlist_for_each_entry(pol, chain, bydst_inexact_list) {
1551 		pol->pos = i;
1552 		i++;
1553 	}
1554 }
1555 
1556 static struct xfrm_policy *xfrm_policy_insert_list(struct hlist_head *chain,
1557 						   struct xfrm_policy *policy,
1558 						   bool excl)
1559 {
1560 	struct xfrm_policy *pol, *newpos = NULL, *delpol = NULL;
1561 
1562 	hlist_for_each_entry(pol, chain, bydst) {
1563 		if (pol->type == policy->type &&
1564 		    pol->if_id == policy->if_id &&
1565 		    !selector_cmp(&pol->selector, &policy->selector) &&
1566 		    xfrm_policy_mark_match(&policy->mark, pol) &&
1567 		    xfrm_sec_ctx_match(pol->security, policy->security) &&
1568 		    !WARN_ON(delpol)) {
1569 			if (excl)
1570 				return ERR_PTR(-EEXIST);
1571 			delpol = pol;
1572 			if (policy->priority > pol->priority)
1573 				continue;
1574 		} else if (policy->priority >= pol->priority) {
1575 			newpos = pol;
1576 			continue;
1577 		}
1578 		if (delpol)
1579 			break;
1580 	}
1581 
1582 	if (newpos && policy->xdo.type != XFRM_DEV_OFFLOAD_PACKET)
1583 		hlist_add_behind_rcu(&policy->bydst, &newpos->bydst);
1584 	else
1585 		/* Packet offload policies enter to the head
1586 		 * to speed-up lookups.
1587 		 */
1588 		hlist_add_head_rcu(&policy->bydst, chain);
1589 
1590 	return delpol;
1591 }
1592 
1593 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
1594 {
1595 	struct net *net = xp_net(policy);
1596 	struct xfrm_policy *delpol;
1597 	struct hlist_head *chain;
1598 
1599 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1600 	chain = policy_hash_bysel(net, &policy->selector, policy->family, dir);
1601 	if (chain)
1602 		delpol = xfrm_policy_insert_list(chain, policy, excl);
1603 	else
1604 		delpol = xfrm_policy_inexact_insert(policy, dir, excl);
1605 
1606 	if (IS_ERR(delpol)) {
1607 		spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1608 		return PTR_ERR(delpol);
1609 	}
1610 
1611 	__xfrm_policy_link(policy, dir);
1612 
1613 	/* After previous checking, family can either be AF_INET or AF_INET6 */
1614 	if (policy->family == AF_INET)
1615 		rt_genid_bump_ipv4(net);
1616 	else
1617 		rt_genid_bump_ipv6(net);
1618 
1619 	if (delpol) {
1620 		xfrm_policy_requeue(delpol, policy);
1621 		__xfrm_policy_unlink(delpol, dir);
1622 	}
1623 	policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir, policy->index);
1624 	hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
1625 	policy->curlft.add_time = ktime_get_real_seconds();
1626 	policy->curlft.use_time = 0;
1627 	if (!mod_timer(&policy->timer, jiffies + HZ))
1628 		xfrm_pol_hold(policy);
1629 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1630 
1631 	if (delpol)
1632 		xfrm_policy_kill(delpol);
1633 	else if (xfrm_bydst_should_resize(net, dir, NULL))
1634 		schedule_work(&net->xfrm.policy_hash_work);
1635 
1636 	return 0;
1637 }
1638 EXPORT_SYMBOL(xfrm_policy_insert);
1639 
1640 static struct xfrm_policy *
1641 __xfrm_policy_bysel_ctx(struct hlist_head *chain, const struct xfrm_mark *mark,
1642 			u32 if_id, u8 type, int dir, struct xfrm_selector *sel,
1643 			struct xfrm_sec_ctx *ctx)
1644 {
1645 	struct xfrm_policy *pol;
1646 
1647 	if (!chain)
1648 		return NULL;
1649 
1650 	hlist_for_each_entry(pol, chain, bydst) {
1651 		if (pol->type == type &&
1652 		    pol->if_id == if_id &&
1653 		    xfrm_policy_mark_match(mark, pol) &&
1654 		    !selector_cmp(sel, &pol->selector) &&
1655 		    xfrm_sec_ctx_match(ctx, pol->security))
1656 			return pol;
1657 	}
1658 
1659 	return NULL;
1660 }
1661 
1662 struct xfrm_policy *
1663 xfrm_policy_bysel_ctx(struct net *net, const struct xfrm_mark *mark, u32 if_id,
1664 		      u8 type, int dir, struct xfrm_selector *sel,
1665 		      struct xfrm_sec_ctx *ctx, int delete, int *err)
1666 {
1667 	struct xfrm_pol_inexact_bin *bin = NULL;
1668 	struct xfrm_policy *pol, *ret = NULL;
1669 	struct hlist_head *chain;
1670 
1671 	*err = 0;
1672 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1673 	chain = policy_hash_bysel(net, sel, sel->family, dir);
1674 	if (!chain) {
1675 		struct xfrm_pol_inexact_candidates cand;
1676 		int i;
1677 
1678 		bin = xfrm_policy_inexact_lookup(net, type,
1679 						 sel->family, dir, if_id);
1680 		if (!bin) {
1681 			spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1682 			return NULL;
1683 		}
1684 
1685 		if (!xfrm_policy_find_inexact_candidates(&cand, bin,
1686 							 &sel->saddr,
1687 							 &sel->daddr)) {
1688 			spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1689 			return NULL;
1690 		}
1691 
1692 		pol = NULL;
1693 		for (i = 0; i < ARRAY_SIZE(cand.res); i++) {
1694 			struct xfrm_policy *tmp;
1695 
1696 			tmp = __xfrm_policy_bysel_ctx(cand.res[i], mark,
1697 						      if_id, type, dir,
1698 						      sel, ctx);
1699 			if (!tmp)
1700 				continue;
1701 
1702 			if (!pol || tmp->pos < pol->pos)
1703 				pol = tmp;
1704 		}
1705 	} else {
1706 		pol = __xfrm_policy_bysel_ctx(chain, mark, if_id, type, dir,
1707 					      sel, ctx);
1708 	}
1709 
1710 	if (pol) {
1711 		xfrm_pol_hold(pol);
1712 		if (delete) {
1713 			*err = security_xfrm_policy_delete(pol->security);
1714 			if (*err) {
1715 				spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1716 				return pol;
1717 			}
1718 			__xfrm_policy_unlink(pol, dir);
1719 		}
1720 		ret = pol;
1721 	}
1722 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1723 
1724 	if (ret && delete)
1725 		xfrm_policy_kill(ret);
1726 	if (bin && delete)
1727 		xfrm_policy_inexact_prune_bin(bin);
1728 	return ret;
1729 }
1730 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
1731 
1732 struct xfrm_policy *
1733 xfrm_policy_byid(struct net *net, const struct xfrm_mark *mark, u32 if_id,
1734 		 u8 type, int dir, u32 id, int delete, int *err)
1735 {
1736 	struct xfrm_policy *pol, *ret;
1737 	struct hlist_head *chain;
1738 
1739 	*err = -ENOENT;
1740 	if (xfrm_policy_id2dir(id) != dir)
1741 		return NULL;
1742 
1743 	*err = 0;
1744 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1745 	chain = net->xfrm.policy_byidx + idx_hash(net, id);
1746 	ret = NULL;
1747 	hlist_for_each_entry(pol, chain, byidx) {
1748 		if (pol->type == type && pol->index == id &&
1749 		    pol->if_id == if_id && xfrm_policy_mark_match(mark, pol)) {
1750 			xfrm_pol_hold(pol);
1751 			if (delete) {
1752 				*err = security_xfrm_policy_delete(
1753 								pol->security);
1754 				if (*err) {
1755 					spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1756 					return pol;
1757 				}
1758 				__xfrm_policy_unlink(pol, dir);
1759 			}
1760 			ret = pol;
1761 			break;
1762 		}
1763 	}
1764 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1765 
1766 	if (ret && delete)
1767 		xfrm_policy_kill(ret);
1768 	return ret;
1769 }
1770 EXPORT_SYMBOL(xfrm_policy_byid);
1771 
1772 #ifdef CONFIG_SECURITY_NETWORK_XFRM
1773 static inline int
1774 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
1775 {
1776 	struct xfrm_policy *pol;
1777 	int err = 0;
1778 
1779 	list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
1780 		if (pol->walk.dead ||
1781 		    xfrm_policy_id2dir(pol->index) >= XFRM_POLICY_MAX ||
1782 		    pol->type != type)
1783 			continue;
1784 
1785 		err = security_xfrm_policy_delete(pol->security);
1786 		if (err) {
1787 			xfrm_audit_policy_delete(pol, 0, task_valid);
1788 			return err;
1789 		}
1790 	}
1791 	return err;
1792 }
1793 
1794 static inline int xfrm_dev_policy_flush_secctx_check(struct net *net,
1795 						     struct net_device *dev,
1796 						     bool task_valid)
1797 {
1798 	struct xfrm_policy *pol;
1799 	int err = 0;
1800 
1801 	list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
1802 		if (pol->walk.dead ||
1803 		    xfrm_policy_id2dir(pol->index) >= XFRM_POLICY_MAX ||
1804 		    pol->xdo.dev != dev)
1805 			continue;
1806 
1807 		err = security_xfrm_policy_delete(pol->security);
1808 		if (err) {
1809 			xfrm_audit_policy_delete(pol, 0, task_valid);
1810 			return err;
1811 		}
1812 	}
1813 	return err;
1814 }
1815 #else
1816 static inline int
1817 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
1818 {
1819 	return 0;
1820 }
1821 
1822 static inline int xfrm_dev_policy_flush_secctx_check(struct net *net,
1823 						     struct net_device *dev,
1824 						     bool task_valid)
1825 {
1826 	return 0;
1827 }
1828 #endif
1829 
1830 int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
1831 {
1832 	int dir, err = 0, cnt = 0;
1833 	struct xfrm_policy *pol;
1834 
1835 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1836 
1837 	err = xfrm_policy_flush_secctx_check(net, type, task_valid);
1838 	if (err)
1839 		goto out;
1840 
1841 again:
1842 	list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
1843 		if (pol->walk.dead)
1844 			continue;
1845 
1846 		dir = xfrm_policy_id2dir(pol->index);
1847 		if (dir >= XFRM_POLICY_MAX ||
1848 		    pol->type != type)
1849 			continue;
1850 
1851 		__xfrm_policy_unlink(pol, dir);
1852 		spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1853 		xfrm_dev_policy_delete(pol);
1854 		cnt++;
1855 		xfrm_audit_policy_delete(pol, 1, task_valid);
1856 		xfrm_policy_kill(pol);
1857 		spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1858 		goto again;
1859 	}
1860 	if (cnt)
1861 		__xfrm_policy_inexact_flush(net);
1862 	else
1863 		err = -ESRCH;
1864 out:
1865 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1866 	return err;
1867 }
1868 EXPORT_SYMBOL(xfrm_policy_flush);
1869 
1870 int xfrm_dev_policy_flush(struct net *net, struct net_device *dev,
1871 			  bool task_valid)
1872 {
1873 	int dir, err = 0, cnt = 0;
1874 	struct xfrm_policy *pol;
1875 
1876 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1877 
1878 	err = xfrm_dev_policy_flush_secctx_check(net, dev, task_valid);
1879 	if (err)
1880 		goto out;
1881 
1882 again:
1883 	list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
1884 		if (pol->walk.dead)
1885 			continue;
1886 
1887 		dir = xfrm_policy_id2dir(pol->index);
1888 		if (dir >= XFRM_POLICY_MAX ||
1889 		    pol->xdo.dev != dev)
1890 			continue;
1891 
1892 		__xfrm_policy_unlink(pol, dir);
1893 		spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1894 		xfrm_dev_policy_delete(pol);
1895 		cnt++;
1896 		xfrm_audit_policy_delete(pol, 1, task_valid);
1897 		xfrm_policy_kill(pol);
1898 		spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1899 		goto again;
1900 	}
1901 	if (cnt)
1902 		__xfrm_policy_inexact_flush(net);
1903 	else
1904 		err = -ESRCH;
1905 out:
1906 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1907 	return err;
1908 }
1909 EXPORT_SYMBOL(xfrm_dev_policy_flush);
1910 
1911 int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
1912 		     int (*func)(struct xfrm_policy *, int, int, void*),
1913 		     void *data)
1914 {
1915 	struct xfrm_policy *pol;
1916 	struct xfrm_policy_walk_entry *x;
1917 	int error = 0;
1918 
1919 	if (walk->type >= XFRM_POLICY_TYPE_MAX &&
1920 	    walk->type != XFRM_POLICY_TYPE_ANY)
1921 		return -EINVAL;
1922 
1923 	if (list_empty(&walk->walk.all) && walk->seq != 0)
1924 		return 0;
1925 
1926 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1927 	if (list_empty(&walk->walk.all))
1928 		x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
1929 	else
1930 		x = list_first_entry(&walk->walk.all,
1931 				     struct xfrm_policy_walk_entry, all);
1932 
1933 	list_for_each_entry_from(x, &net->xfrm.policy_all, all) {
1934 		if (x->dead)
1935 			continue;
1936 		pol = container_of(x, struct xfrm_policy, walk);
1937 		if (walk->type != XFRM_POLICY_TYPE_ANY &&
1938 		    walk->type != pol->type)
1939 			continue;
1940 		error = func(pol, xfrm_policy_id2dir(pol->index),
1941 			     walk->seq, data);
1942 		if (error) {
1943 			list_move_tail(&walk->walk.all, &x->all);
1944 			goto out;
1945 		}
1946 		walk->seq++;
1947 	}
1948 	if (walk->seq == 0) {
1949 		error = -ENOENT;
1950 		goto out;
1951 	}
1952 	list_del_init(&walk->walk.all);
1953 out:
1954 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1955 	return error;
1956 }
1957 EXPORT_SYMBOL(xfrm_policy_walk);
1958 
1959 void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type)
1960 {
1961 	INIT_LIST_HEAD(&walk->walk.all);
1962 	walk->walk.dead = 1;
1963 	walk->type = type;
1964 	walk->seq = 0;
1965 }
1966 EXPORT_SYMBOL(xfrm_policy_walk_init);
1967 
1968 void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net)
1969 {
1970 	if (list_empty(&walk->walk.all))
1971 		return;
1972 
1973 	spin_lock_bh(&net->xfrm.xfrm_policy_lock); /*FIXME where is net? */
1974 	list_del(&walk->walk.all);
1975 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1976 }
1977 EXPORT_SYMBOL(xfrm_policy_walk_done);
1978 
1979 /*
1980  * Find policy to apply to this flow.
1981  *
1982  * Returns 0 if policy found, else an -errno.
1983  */
1984 static int xfrm_policy_match(const struct xfrm_policy *pol,
1985 			     const struct flowi *fl,
1986 			     u8 type, u16 family, u32 if_id)
1987 {
1988 	const struct xfrm_selector *sel = &pol->selector;
1989 	int ret = -ESRCH;
1990 	bool match;
1991 
1992 	if (pol->family != family ||
1993 	    pol->if_id != if_id ||
1994 	    (fl->flowi_mark & pol->mark.m) != pol->mark.v ||
1995 	    pol->type != type)
1996 		return ret;
1997 
1998 	match = xfrm_selector_match(sel, fl, family);
1999 	if (match)
2000 		ret = security_xfrm_policy_lookup(pol->security, fl->flowi_secid);
2001 	return ret;
2002 }
2003 
2004 static struct xfrm_pol_inexact_node *
2005 xfrm_policy_lookup_inexact_addr(const struct rb_root *r,
2006 				seqcount_spinlock_t *count,
2007 				const xfrm_address_t *addr, u16 family)
2008 {
2009 	const struct rb_node *parent;
2010 	int seq;
2011 
2012 again:
2013 	seq = read_seqcount_begin(count);
2014 
2015 	parent = rcu_dereference_raw(r->rb_node);
2016 	while (parent) {
2017 		struct xfrm_pol_inexact_node *node;
2018 		int delta;
2019 
2020 		node = rb_entry(parent, struct xfrm_pol_inexact_node, node);
2021 
2022 		delta = xfrm_policy_addr_delta(addr, &node->addr,
2023 					       node->prefixlen, family);
2024 		if (delta < 0) {
2025 			parent = rcu_dereference_raw(parent->rb_left);
2026 			continue;
2027 		} else if (delta > 0) {
2028 			parent = rcu_dereference_raw(parent->rb_right);
2029 			continue;
2030 		}
2031 
2032 		return node;
2033 	}
2034 
2035 	if (read_seqcount_retry(count, seq))
2036 		goto again;
2037 
2038 	return NULL;
2039 }
2040 
2041 static bool
2042 xfrm_policy_find_inexact_candidates(struct xfrm_pol_inexact_candidates *cand,
2043 				    struct xfrm_pol_inexact_bin *b,
2044 				    const xfrm_address_t *saddr,
2045 				    const xfrm_address_t *daddr)
2046 {
2047 	struct xfrm_pol_inexact_node *n;
2048 	u16 family;
2049 
2050 	if (!b)
2051 		return false;
2052 
2053 	family = b->k.family;
2054 	memset(cand, 0, sizeof(*cand));
2055 	cand->res[XFRM_POL_CAND_ANY] = &b->hhead;
2056 
2057 	n = xfrm_policy_lookup_inexact_addr(&b->root_d, &b->count, daddr,
2058 					    family);
2059 	if (n) {
2060 		cand->res[XFRM_POL_CAND_DADDR] = &n->hhead;
2061 		n = xfrm_policy_lookup_inexact_addr(&n->root, &b->count, saddr,
2062 						    family);
2063 		if (n)
2064 			cand->res[XFRM_POL_CAND_BOTH] = &n->hhead;
2065 	}
2066 
2067 	n = xfrm_policy_lookup_inexact_addr(&b->root_s, &b->count, saddr,
2068 					    family);
2069 	if (n)
2070 		cand->res[XFRM_POL_CAND_SADDR] = &n->hhead;
2071 
2072 	return true;
2073 }
2074 
2075 static struct xfrm_pol_inexact_bin *
2076 xfrm_policy_inexact_lookup_rcu(struct net *net, u8 type, u16 family,
2077 			       u8 dir, u32 if_id)
2078 {
2079 	struct xfrm_pol_inexact_key k = {
2080 		.family = family,
2081 		.type = type,
2082 		.dir = dir,
2083 		.if_id = if_id,
2084 	};
2085 
2086 	write_pnet(&k.net, net);
2087 
2088 	return rhashtable_lookup(&xfrm_policy_inexact_table, &k,
2089 				 xfrm_pol_inexact_params);
2090 }
2091 
2092 static struct xfrm_pol_inexact_bin *
2093 xfrm_policy_inexact_lookup(struct net *net, u8 type, u16 family,
2094 			   u8 dir, u32 if_id)
2095 {
2096 	struct xfrm_pol_inexact_bin *bin;
2097 
2098 	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
2099 
2100 	rcu_read_lock();
2101 	bin = xfrm_policy_inexact_lookup_rcu(net, type, family, dir, if_id);
2102 	rcu_read_unlock();
2103 
2104 	return bin;
2105 }
2106 
2107 static struct xfrm_policy *
2108 __xfrm_policy_eval_candidates(struct hlist_head *chain,
2109 			      struct xfrm_policy *prefer,
2110 			      const struct flowi *fl,
2111 			      u8 type, u16 family, u32 if_id)
2112 {
2113 	u32 priority = prefer ? prefer->priority : ~0u;
2114 	struct xfrm_policy *pol;
2115 
2116 	if (!chain)
2117 		return NULL;
2118 
2119 	hlist_for_each_entry_rcu(pol, chain, bydst) {
2120 		int err;
2121 
2122 		if (pol->priority > priority)
2123 			break;
2124 
2125 		err = xfrm_policy_match(pol, fl, type, family, if_id);
2126 		if (err) {
2127 			if (err != -ESRCH)
2128 				return ERR_PTR(err);
2129 
2130 			continue;
2131 		}
2132 
2133 		if (prefer) {
2134 			/* matches.  Is it older than *prefer? */
2135 			if (pol->priority == priority &&
2136 			    prefer->pos < pol->pos)
2137 				return prefer;
2138 		}
2139 
2140 		return pol;
2141 	}
2142 
2143 	return NULL;
2144 }
2145 
2146 static struct xfrm_policy *
2147 xfrm_policy_eval_candidates(struct xfrm_pol_inexact_candidates *cand,
2148 			    struct xfrm_policy *prefer,
2149 			    const struct flowi *fl,
2150 			    u8 type, u16 family, u32 if_id)
2151 {
2152 	struct xfrm_policy *tmp;
2153 	int i;
2154 
2155 	for (i = 0; i < ARRAY_SIZE(cand->res); i++) {
2156 		tmp = __xfrm_policy_eval_candidates(cand->res[i],
2157 						    prefer,
2158 						    fl, type, family, if_id);
2159 		if (!tmp)
2160 			continue;
2161 
2162 		if (IS_ERR(tmp))
2163 			return tmp;
2164 		prefer = tmp;
2165 	}
2166 
2167 	return prefer;
2168 }
2169 
2170 static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
2171 						     const struct flowi *fl,
2172 						     u16 family, u8 dir,
2173 						     u32 if_id)
2174 {
2175 	struct xfrm_pol_inexact_candidates cand;
2176 	const xfrm_address_t *daddr, *saddr;
2177 	struct xfrm_pol_inexact_bin *bin;
2178 	struct xfrm_policy *pol, *ret;
2179 	struct hlist_head *chain;
2180 	unsigned int sequence;
2181 	int err;
2182 
2183 	daddr = xfrm_flowi_daddr(fl, family);
2184 	saddr = xfrm_flowi_saddr(fl, family);
2185 	if (unlikely(!daddr || !saddr))
2186 		return NULL;
2187 
2188 	rcu_read_lock();
2189  retry:
2190 	do {
2191 		sequence = read_seqcount_begin(&net->xfrm.xfrm_policy_hash_generation);
2192 		chain = policy_hash_direct(net, daddr, saddr, family, dir);
2193 	} while (read_seqcount_retry(&net->xfrm.xfrm_policy_hash_generation, sequence));
2194 
2195 	ret = NULL;
2196 	hlist_for_each_entry_rcu(pol, chain, bydst) {
2197 		err = xfrm_policy_match(pol, fl, type, family, if_id);
2198 		if (err) {
2199 			if (err == -ESRCH)
2200 				continue;
2201 			else {
2202 				ret = ERR_PTR(err);
2203 				goto fail;
2204 			}
2205 		} else {
2206 			ret = pol;
2207 			break;
2208 		}
2209 	}
2210 	if (ret && ret->xdo.type == XFRM_DEV_OFFLOAD_PACKET)
2211 		goto skip_inexact;
2212 
2213 	bin = xfrm_policy_inexact_lookup_rcu(net, type, family, dir, if_id);
2214 	if (!bin || !xfrm_policy_find_inexact_candidates(&cand, bin, saddr,
2215 							 daddr))
2216 		goto skip_inexact;
2217 
2218 	pol = xfrm_policy_eval_candidates(&cand, ret, fl, type,
2219 					  family, if_id);
2220 	if (pol) {
2221 		ret = pol;
2222 		if (IS_ERR(pol))
2223 			goto fail;
2224 	}
2225 
2226 skip_inexact:
2227 	if (read_seqcount_retry(&net->xfrm.xfrm_policy_hash_generation, sequence))
2228 		goto retry;
2229 
2230 	if (ret && !xfrm_pol_hold_rcu(ret))
2231 		goto retry;
2232 fail:
2233 	rcu_read_unlock();
2234 
2235 	return ret;
2236 }
2237 
2238 static struct xfrm_policy *xfrm_policy_lookup(struct net *net,
2239 					      const struct flowi *fl,
2240 					      u16 family, u8 dir, u32 if_id)
2241 {
2242 #ifdef CONFIG_XFRM_SUB_POLICY
2243 	struct xfrm_policy *pol;
2244 
2245 	pol = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_SUB, fl, family,
2246 					dir, if_id);
2247 	if (pol != NULL)
2248 		return pol;
2249 #endif
2250 	return xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, fl, family,
2251 					 dir, if_id);
2252 }
2253 
2254 static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir,
2255 						 const struct flowi *fl,
2256 						 u16 family, u32 if_id)
2257 {
2258 	struct xfrm_policy *pol;
2259 
2260 	rcu_read_lock();
2261  again:
2262 	pol = rcu_dereference(sk->sk_policy[dir]);
2263 	if (pol != NULL) {
2264 		bool match;
2265 		int err = 0;
2266 
2267 		if (pol->family != family) {
2268 			pol = NULL;
2269 			goto out;
2270 		}
2271 
2272 		match = xfrm_selector_match(&pol->selector, fl, family);
2273 		if (match) {
2274 			if ((READ_ONCE(sk->sk_mark) & pol->mark.m) != pol->mark.v ||
2275 			    pol->if_id != if_id) {
2276 				pol = NULL;
2277 				goto out;
2278 			}
2279 			err = security_xfrm_policy_lookup(pol->security,
2280 						      fl->flowi_secid);
2281 			if (!err) {
2282 				if (!xfrm_pol_hold_rcu(pol))
2283 					goto again;
2284 			} else if (err == -ESRCH) {
2285 				pol = NULL;
2286 			} else {
2287 				pol = ERR_PTR(err);
2288 			}
2289 		} else
2290 			pol = NULL;
2291 	}
2292 out:
2293 	rcu_read_unlock();
2294 	return pol;
2295 }
2296 
2297 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
2298 {
2299 	struct net *net = xp_net(pol);
2300 
2301 	list_add(&pol->walk.all, &net->xfrm.policy_all);
2302 	net->xfrm.policy_count[dir]++;
2303 	xfrm_pol_hold(pol);
2304 }
2305 
2306 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
2307 						int dir)
2308 {
2309 	struct net *net = xp_net(pol);
2310 
2311 	if (list_empty(&pol->walk.all))
2312 		return NULL;
2313 
2314 	/* Socket policies are not hashed. */
2315 	if (!hlist_unhashed(&pol->bydst)) {
2316 		hlist_del_rcu(&pol->bydst);
2317 		hlist_del_init(&pol->bydst_inexact_list);
2318 		hlist_del(&pol->byidx);
2319 	}
2320 
2321 	list_del_init(&pol->walk.all);
2322 	net->xfrm.policy_count[dir]--;
2323 
2324 	return pol;
2325 }
2326 
2327 static void xfrm_sk_policy_link(struct xfrm_policy *pol, int dir)
2328 {
2329 	__xfrm_policy_link(pol, XFRM_POLICY_MAX + dir);
2330 }
2331 
2332 static void xfrm_sk_policy_unlink(struct xfrm_policy *pol, int dir)
2333 {
2334 	__xfrm_policy_unlink(pol, XFRM_POLICY_MAX + dir);
2335 }
2336 
2337 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
2338 {
2339 	struct net *net = xp_net(pol);
2340 
2341 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2342 	pol = __xfrm_policy_unlink(pol, dir);
2343 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2344 	if (pol) {
2345 		xfrm_dev_policy_delete(pol);
2346 		xfrm_policy_kill(pol);
2347 		return 0;
2348 	}
2349 	return -ENOENT;
2350 }
2351 EXPORT_SYMBOL(xfrm_policy_delete);
2352 
2353 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
2354 {
2355 	struct net *net = sock_net(sk);
2356 	struct xfrm_policy *old_pol;
2357 
2358 #ifdef CONFIG_XFRM_SUB_POLICY
2359 	if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
2360 		return -EINVAL;
2361 #endif
2362 
2363 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2364 	old_pol = rcu_dereference_protected(sk->sk_policy[dir],
2365 				lockdep_is_held(&net->xfrm.xfrm_policy_lock));
2366 	if (pol) {
2367 		pol->curlft.add_time = ktime_get_real_seconds();
2368 		pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir, 0);
2369 		xfrm_sk_policy_link(pol, dir);
2370 	}
2371 	rcu_assign_pointer(sk->sk_policy[dir], pol);
2372 	if (old_pol) {
2373 		if (pol)
2374 			xfrm_policy_requeue(old_pol, pol);
2375 
2376 		/* Unlinking succeeds always. This is the only function
2377 		 * allowed to delete or replace socket policy.
2378 		 */
2379 		xfrm_sk_policy_unlink(old_pol, dir);
2380 	}
2381 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2382 
2383 	if (old_pol) {
2384 		xfrm_policy_kill(old_pol);
2385 	}
2386 	return 0;
2387 }
2388 
2389 static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
2390 {
2391 	struct xfrm_policy *newp = xfrm_policy_alloc(xp_net(old), GFP_ATOMIC);
2392 	struct net *net = xp_net(old);
2393 
2394 	if (newp) {
2395 		newp->selector = old->selector;
2396 		if (security_xfrm_policy_clone(old->security,
2397 					       &newp->security)) {
2398 			kfree(newp);
2399 			return NULL;  /* ENOMEM */
2400 		}
2401 		newp->lft = old->lft;
2402 		newp->curlft = old->curlft;
2403 		newp->mark = old->mark;
2404 		newp->if_id = old->if_id;
2405 		newp->action = old->action;
2406 		newp->flags = old->flags;
2407 		newp->xfrm_nr = old->xfrm_nr;
2408 		newp->index = old->index;
2409 		newp->type = old->type;
2410 		newp->family = old->family;
2411 		memcpy(newp->xfrm_vec, old->xfrm_vec,
2412 		       newp->xfrm_nr*sizeof(struct xfrm_tmpl));
2413 		spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2414 		xfrm_sk_policy_link(newp, dir);
2415 		spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2416 		xfrm_pol_put(newp);
2417 	}
2418 	return newp;
2419 }
2420 
2421 int __xfrm_sk_clone_policy(struct sock *sk, const struct sock *osk)
2422 {
2423 	const struct xfrm_policy *p;
2424 	struct xfrm_policy *np;
2425 	int i, ret = 0;
2426 
2427 	rcu_read_lock();
2428 	for (i = 0; i < 2; i++) {
2429 		p = rcu_dereference(osk->sk_policy[i]);
2430 		if (p) {
2431 			np = clone_policy(p, i);
2432 			if (unlikely(!np)) {
2433 				ret = -ENOMEM;
2434 				break;
2435 			}
2436 			rcu_assign_pointer(sk->sk_policy[i], np);
2437 		}
2438 	}
2439 	rcu_read_unlock();
2440 	return ret;
2441 }
2442 
2443 static int
2444 xfrm_get_saddr(struct net *net, int oif, xfrm_address_t *local,
2445 	       xfrm_address_t *remote, unsigned short family, u32 mark)
2446 {
2447 	int err;
2448 	const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2449 
2450 	if (unlikely(afinfo == NULL))
2451 		return -EINVAL;
2452 	err = afinfo->get_saddr(net, oif, local, remote, mark);
2453 	rcu_read_unlock();
2454 	return err;
2455 }
2456 
2457 /* Resolve list of templates for the flow, given policy. */
2458 
2459 static int
2460 xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
2461 		      struct xfrm_state **xfrm, unsigned short family)
2462 {
2463 	struct net *net = xp_net(policy);
2464 	int nx;
2465 	int i, error;
2466 	xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
2467 	xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
2468 	xfrm_address_t tmp;
2469 
2470 	for (nx = 0, i = 0; i < policy->xfrm_nr; i++) {
2471 		struct xfrm_state *x;
2472 		xfrm_address_t *remote = daddr;
2473 		xfrm_address_t *local  = saddr;
2474 		struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
2475 
2476 		if (tmpl->mode == XFRM_MODE_TUNNEL ||
2477 		    tmpl->mode == XFRM_MODE_BEET) {
2478 			remote = &tmpl->id.daddr;
2479 			local = &tmpl->saddr;
2480 			if (xfrm_addr_any(local, tmpl->encap_family)) {
2481 				error = xfrm_get_saddr(net, fl->flowi_oif,
2482 						       &tmp, remote,
2483 						       tmpl->encap_family, 0);
2484 				if (error)
2485 					goto fail;
2486 				local = &tmp;
2487 			}
2488 		}
2489 
2490 		x = xfrm_state_find(remote, local, fl, tmpl, policy, &error,
2491 				    family, policy->if_id);
2492 		if (x && x->dir && x->dir != XFRM_SA_DIR_OUT) {
2493 			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEDIRERROR);
2494 			xfrm_state_put(x);
2495 			error = -EINVAL;
2496 			goto fail;
2497 		}
2498 
2499 		if (x && x->km.state == XFRM_STATE_VALID) {
2500 			xfrm[nx++] = x;
2501 			daddr = remote;
2502 			saddr = local;
2503 			continue;
2504 		}
2505 		if (x) {
2506 			error = (x->km.state == XFRM_STATE_ERROR ?
2507 				 -EINVAL : -EAGAIN);
2508 			xfrm_state_put(x);
2509 		} else if (error == -ESRCH) {
2510 			error = -EAGAIN;
2511 		}
2512 
2513 		if (!tmpl->optional)
2514 			goto fail;
2515 	}
2516 	return nx;
2517 
2518 fail:
2519 	for (nx--; nx >= 0; nx--)
2520 		xfrm_state_put(xfrm[nx]);
2521 	return error;
2522 }
2523 
2524 static int
2525 xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, const struct flowi *fl,
2526 		  struct xfrm_state **xfrm, unsigned short family)
2527 {
2528 	struct xfrm_state *tp[XFRM_MAX_DEPTH];
2529 	struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
2530 	int cnx = 0;
2531 	int error;
2532 	int ret;
2533 	int i;
2534 
2535 	for (i = 0; i < npols; i++) {
2536 		if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
2537 			error = -ENOBUFS;
2538 			goto fail;
2539 		}
2540 
2541 		ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
2542 		if (ret < 0) {
2543 			error = ret;
2544 			goto fail;
2545 		} else
2546 			cnx += ret;
2547 	}
2548 
2549 	/* found states are sorted for outbound processing */
2550 	if (npols > 1)
2551 		xfrm_state_sort(xfrm, tpp, cnx, family);
2552 
2553 	return cnx;
2554 
2555  fail:
2556 	for (cnx--; cnx >= 0; cnx--)
2557 		xfrm_state_put(tpp[cnx]);
2558 	return error;
2559 
2560 }
2561 
2562 static int xfrm_get_tos(const struct flowi *fl, int family)
2563 {
2564 	if (family == AF_INET)
2565 		return IPTOS_RT_MASK & fl->u.ip4.flowi4_tos;
2566 
2567 	return 0;
2568 }
2569 
2570 static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
2571 {
2572 	const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2573 	struct dst_ops *dst_ops;
2574 	struct xfrm_dst *xdst;
2575 
2576 	if (!afinfo)
2577 		return ERR_PTR(-EINVAL);
2578 
2579 	switch (family) {
2580 	case AF_INET:
2581 		dst_ops = &net->xfrm.xfrm4_dst_ops;
2582 		break;
2583 #if IS_ENABLED(CONFIG_IPV6)
2584 	case AF_INET6:
2585 		dst_ops = &net->xfrm.xfrm6_dst_ops;
2586 		break;
2587 #endif
2588 	default:
2589 		BUG();
2590 	}
2591 	xdst = dst_alloc(dst_ops, NULL, DST_OBSOLETE_NONE, 0);
2592 
2593 	if (likely(xdst)) {
2594 		memset_after(xdst, 0, u.dst);
2595 	} else
2596 		xdst = ERR_PTR(-ENOBUFS);
2597 
2598 	rcu_read_unlock();
2599 
2600 	return xdst;
2601 }
2602 
2603 static void xfrm_init_path(struct xfrm_dst *path, struct dst_entry *dst,
2604 			   int nfheader_len)
2605 {
2606 	if (dst->ops->family == AF_INET6) {
2607 		path->path_cookie = rt6_get_cookie(dst_rt6_info(dst));
2608 		path->u.rt6.rt6i_nfheader_len = nfheader_len;
2609 	}
2610 }
2611 
2612 static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
2613 				const struct flowi *fl)
2614 {
2615 	const struct xfrm_policy_afinfo *afinfo =
2616 		xfrm_policy_get_afinfo(xdst->u.dst.ops->family);
2617 	int err;
2618 
2619 	if (!afinfo)
2620 		return -EINVAL;
2621 
2622 	err = afinfo->fill_dst(xdst, dev, fl);
2623 
2624 	rcu_read_unlock();
2625 
2626 	return err;
2627 }
2628 
2629 
2630 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
2631  * all the metrics... Shortly, bundle a bundle.
2632  */
2633 
2634 static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
2635 					    struct xfrm_state **xfrm,
2636 					    struct xfrm_dst **bundle,
2637 					    int nx,
2638 					    const struct flowi *fl,
2639 					    struct dst_entry *dst)
2640 {
2641 	const struct xfrm_state_afinfo *afinfo;
2642 	const struct xfrm_mode *inner_mode;
2643 	struct net *net = xp_net(policy);
2644 	unsigned long now = jiffies;
2645 	struct net_device *dev;
2646 	struct xfrm_dst *xdst_prev = NULL;
2647 	struct xfrm_dst *xdst0 = NULL;
2648 	int i = 0;
2649 	int err;
2650 	int header_len = 0;
2651 	int nfheader_len = 0;
2652 	int trailer_len = 0;
2653 	int tos;
2654 	int family = policy->selector.family;
2655 	xfrm_address_t saddr, daddr;
2656 
2657 	xfrm_flowi_addr_get(fl, &saddr, &daddr, family);
2658 
2659 	tos = xfrm_get_tos(fl, family);
2660 
2661 	dst_hold(dst);
2662 
2663 	for (; i < nx; i++) {
2664 		struct xfrm_dst *xdst = xfrm_alloc_dst(net, family);
2665 		struct dst_entry *dst1 = &xdst->u.dst;
2666 
2667 		err = PTR_ERR(xdst);
2668 		if (IS_ERR(xdst)) {
2669 			dst_release(dst);
2670 			goto put_states;
2671 		}
2672 
2673 		bundle[i] = xdst;
2674 		if (!xdst_prev)
2675 			xdst0 = xdst;
2676 		else
2677 			/* Ref count is taken during xfrm_alloc_dst()
2678 			 * No need to do dst_clone() on dst1
2679 			 */
2680 			xfrm_dst_set_child(xdst_prev, &xdst->u.dst);
2681 
2682 		if (xfrm[i]->sel.family == AF_UNSPEC) {
2683 			inner_mode = xfrm_ip2inner_mode(xfrm[i],
2684 							xfrm_af2proto(family));
2685 			if (!inner_mode) {
2686 				err = -EAFNOSUPPORT;
2687 				dst_release(dst);
2688 				goto put_states;
2689 			}
2690 		} else
2691 			inner_mode = &xfrm[i]->inner_mode;
2692 
2693 		xdst->route = dst;
2694 		dst_copy_metrics(dst1, dst);
2695 
2696 		if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
2697 			__u32 mark = 0;
2698 			int oif;
2699 
2700 			if (xfrm[i]->props.smark.v || xfrm[i]->props.smark.m)
2701 				mark = xfrm_smark_get(fl->flowi_mark, xfrm[i]);
2702 
2703 			if (xfrm[i]->xso.type != XFRM_DEV_OFFLOAD_PACKET)
2704 				family = xfrm[i]->props.family;
2705 
2706 			oif = fl->flowi_oif ? : fl->flowi_l3mdev;
2707 			dst = xfrm_dst_lookup(xfrm[i], tos, oif,
2708 					      &saddr, &daddr, family, mark);
2709 			err = PTR_ERR(dst);
2710 			if (IS_ERR(dst))
2711 				goto put_states;
2712 		} else
2713 			dst_hold(dst);
2714 
2715 		dst1->xfrm = xfrm[i];
2716 		xdst->xfrm_genid = xfrm[i]->genid;
2717 
2718 		dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
2719 		dst1->lastuse = now;
2720 
2721 		dst1->input = dst_discard;
2722 
2723 		rcu_read_lock();
2724 		afinfo = xfrm_state_afinfo_get_rcu(inner_mode->family);
2725 		if (likely(afinfo))
2726 			dst1->output = afinfo->output;
2727 		else
2728 			dst1->output = dst_discard_out;
2729 		rcu_read_unlock();
2730 
2731 		xdst_prev = xdst;
2732 
2733 		header_len += xfrm[i]->props.header_len;
2734 		if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
2735 			nfheader_len += xfrm[i]->props.header_len;
2736 		trailer_len += xfrm[i]->props.trailer_len;
2737 	}
2738 
2739 	xfrm_dst_set_child(xdst_prev, dst);
2740 	xdst0->path = dst;
2741 
2742 	err = -ENODEV;
2743 	dev = dst->dev;
2744 	if (!dev)
2745 		goto free_dst;
2746 
2747 	xfrm_init_path(xdst0, dst, nfheader_len);
2748 	xfrm_init_pmtu(bundle, nx);
2749 
2750 	for (xdst_prev = xdst0; xdst_prev != (struct xfrm_dst *)dst;
2751 	     xdst_prev = (struct xfrm_dst *) xfrm_dst_child(&xdst_prev->u.dst)) {
2752 		err = xfrm_fill_dst(xdst_prev, dev, fl);
2753 		if (err)
2754 			goto free_dst;
2755 
2756 		xdst_prev->u.dst.header_len = header_len;
2757 		xdst_prev->u.dst.trailer_len = trailer_len;
2758 		header_len -= xdst_prev->u.dst.xfrm->props.header_len;
2759 		trailer_len -= xdst_prev->u.dst.xfrm->props.trailer_len;
2760 	}
2761 
2762 	return &xdst0->u.dst;
2763 
2764 put_states:
2765 	for (; i < nx; i++)
2766 		xfrm_state_put(xfrm[i]);
2767 free_dst:
2768 	if (xdst0)
2769 		dst_release_immediate(&xdst0->u.dst);
2770 
2771 	return ERR_PTR(err);
2772 }
2773 
2774 static int xfrm_expand_policies(const struct flowi *fl, u16 family,
2775 				struct xfrm_policy **pols,
2776 				int *num_pols, int *num_xfrms)
2777 {
2778 	int i;
2779 
2780 	if (*num_pols == 0 || !pols[0]) {
2781 		*num_pols = 0;
2782 		*num_xfrms = 0;
2783 		return 0;
2784 	}
2785 	if (IS_ERR(pols[0])) {
2786 		*num_pols = 0;
2787 		return PTR_ERR(pols[0]);
2788 	}
2789 
2790 	*num_xfrms = pols[0]->xfrm_nr;
2791 
2792 #ifdef CONFIG_XFRM_SUB_POLICY
2793 	if (pols[0]->action == XFRM_POLICY_ALLOW &&
2794 	    pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
2795 		pols[1] = xfrm_policy_lookup_bytype(xp_net(pols[0]),
2796 						    XFRM_POLICY_TYPE_MAIN,
2797 						    fl, family,
2798 						    XFRM_POLICY_OUT,
2799 						    pols[0]->if_id);
2800 		if (pols[1]) {
2801 			if (IS_ERR(pols[1])) {
2802 				xfrm_pols_put(pols, *num_pols);
2803 				*num_pols = 0;
2804 				return PTR_ERR(pols[1]);
2805 			}
2806 			(*num_pols)++;
2807 			(*num_xfrms) += pols[1]->xfrm_nr;
2808 		}
2809 	}
2810 #endif
2811 	for (i = 0; i < *num_pols; i++) {
2812 		if (pols[i]->action != XFRM_POLICY_ALLOW) {
2813 			*num_xfrms = -1;
2814 			break;
2815 		}
2816 	}
2817 
2818 	return 0;
2819 
2820 }
2821 
2822 static struct xfrm_dst *
2823 xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
2824 			       const struct flowi *fl, u16 family,
2825 			       struct dst_entry *dst_orig)
2826 {
2827 	struct net *net = xp_net(pols[0]);
2828 	struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
2829 	struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
2830 	struct xfrm_dst *xdst;
2831 	struct dst_entry *dst;
2832 	int err;
2833 
2834 	/* Try to instantiate a bundle */
2835 	err = xfrm_tmpl_resolve(pols, num_pols, fl, xfrm, family);
2836 	if (err <= 0) {
2837 		if (err == 0)
2838 			return NULL;
2839 
2840 		if (err != -EAGAIN)
2841 			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
2842 		return ERR_PTR(err);
2843 	}
2844 
2845 	dst = xfrm_bundle_create(pols[0], xfrm, bundle, err, fl, dst_orig);
2846 	if (IS_ERR(dst)) {
2847 		XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR);
2848 		return ERR_CAST(dst);
2849 	}
2850 
2851 	xdst = (struct xfrm_dst *)dst;
2852 	xdst->num_xfrms = err;
2853 	xdst->num_pols = num_pols;
2854 	memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
2855 	xdst->policy_genid = atomic_read(&pols[0]->genid);
2856 
2857 	return xdst;
2858 }
2859 
2860 static void xfrm_policy_queue_process(struct timer_list *t)
2861 {
2862 	struct sk_buff *skb;
2863 	struct sock *sk;
2864 	struct dst_entry *dst;
2865 	struct xfrm_policy *pol = from_timer(pol, t, polq.hold_timer);
2866 	struct net *net = xp_net(pol);
2867 	struct xfrm_policy_queue *pq = &pol->polq;
2868 	struct flowi fl;
2869 	struct sk_buff_head list;
2870 	__u32 skb_mark;
2871 
2872 	spin_lock(&pq->hold_queue.lock);
2873 	skb = skb_peek(&pq->hold_queue);
2874 	if (!skb) {
2875 		spin_unlock(&pq->hold_queue.lock);
2876 		goto out;
2877 	}
2878 	dst = skb_dst(skb);
2879 	sk = skb->sk;
2880 
2881 	/* Fixup the mark to support VTI. */
2882 	skb_mark = skb->mark;
2883 	skb->mark = pol->mark.v;
2884 	xfrm_decode_session(net, skb, &fl, dst->ops->family);
2885 	skb->mark = skb_mark;
2886 	spin_unlock(&pq->hold_queue.lock);
2887 
2888 	dst_hold(xfrm_dst_path(dst));
2889 	dst = xfrm_lookup(net, xfrm_dst_path(dst), &fl, sk, XFRM_LOOKUP_QUEUE);
2890 	if (IS_ERR(dst))
2891 		goto purge_queue;
2892 
2893 	if (dst->flags & DST_XFRM_QUEUE) {
2894 		dst_release(dst);
2895 
2896 		if (pq->timeout >= XFRM_QUEUE_TMO_MAX)
2897 			goto purge_queue;
2898 
2899 		pq->timeout = pq->timeout << 1;
2900 		if (!mod_timer(&pq->hold_timer, jiffies + pq->timeout))
2901 			xfrm_pol_hold(pol);
2902 		goto out;
2903 	}
2904 
2905 	dst_release(dst);
2906 
2907 	__skb_queue_head_init(&list);
2908 
2909 	spin_lock(&pq->hold_queue.lock);
2910 	pq->timeout = 0;
2911 	skb_queue_splice_init(&pq->hold_queue, &list);
2912 	spin_unlock(&pq->hold_queue.lock);
2913 
2914 	while (!skb_queue_empty(&list)) {
2915 		skb = __skb_dequeue(&list);
2916 
2917 		/* Fixup the mark to support VTI. */
2918 		skb_mark = skb->mark;
2919 		skb->mark = pol->mark.v;
2920 		xfrm_decode_session(net, skb, &fl, skb_dst(skb)->ops->family);
2921 		skb->mark = skb_mark;
2922 
2923 		dst_hold(xfrm_dst_path(skb_dst(skb)));
2924 		dst = xfrm_lookup(net, xfrm_dst_path(skb_dst(skb)), &fl, skb->sk, 0);
2925 		if (IS_ERR(dst)) {
2926 			kfree_skb(skb);
2927 			continue;
2928 		}
2929 
2930 		nf_reset_ct(skb);
2931 		skb_dst_drop(skb);
2932 		skb_dst_set(skb, dst);
2933 
2934 		dst_output(net, skb->sk, skb);
2935 	}
2936 
2937 out:
2938 	xfrm_pol_put(pol);
2939 	return;
2940 
2941 purge_queue:
2942 	pq->timeout = 0;
2943 	skb_queue_purge(&pq->hold_queue);
2944 	xfrm_pol_put(pol);
2945 }
2946 
2947 static int xdst_queue_output(struct net *net, struct sock *sk, struct sk_buff *skb)
2948 {
2949 	unsigned long sched_next;
2950 	struct dst_entry *dst = skb_dst(skb);
2951 	struct xfrm_dst *xdst = (struct xfrm_dst *) dst;
2952 	struct xfrm_policy *pol = xdst->pols[0];
2953 	struct xfrm_policy_queue *pq = &pol->polq;
2954 
2955 	if (unlikely(skb_fclone_busy(sk, skb))) {
2956 		kfree_skb(skb);
2957 		return 0;
2958 	}
2959 
2960 	if (pq->hold_queue.qlen > XFRM_MAX_QUEUE_LEN) {
2961 		kfree_skb(skb);
2962 		return -EAGAIN;
2963 	}
2964 
2965 	skb_dst_force(skb);
2966 
2967 	spin_lock_bh(&pq->hold_queue.lock);
2968 
2969 	if (!pq->timeout)
2970 		pq->timeout = XFRM_QUEUE_TMO_MIN;
2971 
2972 	sched_next = jiffies + pq->timeout;
2973 
2974 	if (del_timer(&pq->hold_timer)) {
2975 		if (time_before(pq->hold_timer.expires, sched_next))
2976 			sched_next = pq->hold_timer.expires;
2977 		xfrm_pol_put(pol);
2978 	}
2979 
2980 	__skb_queue_tail(&pq->hold_queue, skb);
2981 	if (!mod_timer(&pq->hold_timer, sched_next))
2982 		xfrm_pol_hold(pol);
2983 
2984 	spin_unlock_bh(&pq->hold_queue.lock);
2985 
2986 	return 0;
2987 }
2988 
2989 static struct xfrm_dst *xfrm_create_dummy_bundle(struct net *net,
2990 						 struct xfrm_flo *xflo,
2991 						 const struct flowi *fl,
2992 						 int num_xfrms,
2993 						 u16 family)
2994 {
2995 	int err;
2996 	struct net_device *dev;
2997 	struct dst_entry *dst;
2998 	struct dst_entry *dst1;
2999 	struct xfrm_dst *xdst;
3000 
3001 	xdst = xfrm_alloc_dst(net, family);
3002 	if (IS_ERR(xdst))
3003 		return xdst;
3004 
3005 	if (!(xflo->flags & XFRM_LOOKUP_QUEUE) ||
3006 	    net->xfrm.sysctl_larval_drop ||
3007 	    num_xfrms <= 0)
3008 		return xdst;
3009 
3010 	dst = xflo->dst_orig;
3011 	dst1 = &xdst->u.dst;
3012 	dst_hold(dst);
3013 	xdst->route = dst;
3014 
3015 	dst_copy_metrics(dst1, dst);
3016 
3017 	dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
3018 	dst1->flags |= DST_XFRM_QUEUE;
3019 	dst1->lastuse = jiffies;
3020 
3021 	dst1->input = dst_discard;
3022 	dst1->output = xdst_queue_output;
3023 
3024 	dst_hold(dst);
3025 	xfrm_dst_set_child(xdst, dst);
3026 	xdst->path = dst;
3027 
3028 	xfrm_init_path((struct xfrm_dst *)dst1, dst, 0);
3029 
3030 	err = -ENODEV;
3031 	dev = dst->dev;
3032 	if (!dev)
3033 		goto free_dst;
3034 
3035 	err = xfrm_fill_dst(xdst, dev, fl);
3036 	if (err)
3037 		goto free_dst;
3038 
3039 out:
3040 	return xdst;
3041 
3042 free_dst:
3043 	dst_release(dst1);
3044 	xdst = ERR_PTR(err);
3045 	goto out;
3046 }
3047 
3048 static struct xfrm_dst *xfrm_bundle_lookup(struct net *net,
3049 					   const struct flowi *fl,
3050 					   u16 family, u8 dir,
3051 					   struct xfrm_flo *xflo, u32 if_id)
3052 {
3053 	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
3054 	int num_pols = 0, num_xfrms = 0, err;
3055 	struct xfrm_dst *xdst;
3056 
3057 	/* Resolve policies to use if we couldn't get them from
3058 	 * previous cache entry */
3059 	num_pols = 1;
3060 	pols[0] = xfrm_policy_lookup(net, fl, family, dir, if_id);
3061 	err = xfrm_expand_policies(fl, family, pols,
3062 					   &num_pols, &num_xfrms);
3063 	if (err < 0)
3064 		goto inc_error;
3065 	if (num_pols == 0)
3066 		return NULL;
3067 	if (num_xfrms <= 0)
3068 		goto make_dummy_bundle;
3069 
3070 	xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family,
3071 					      xflo->dst_orig);
3072 	if (IS_ERR(xdst)) {
3073 		err = PTR_ERR(xdst);
3074 		if (err == -EREMOTE) {
3075 			xfrm_pols_put(pols, num_pols);
3076 			return NULL;
3077 		}
3078 
3079 		if (err != -EAGAIN)
3080 			goto error;
3081 		goto make_dummy_bundle;
3082 	} else if (xdst == NULL) {
3083 		num_xfrms = 0;
3084 		goto make_dummy_bundle;
3085 	}
3086 
3087 	return xdst;
3088 
3089 make_dummy_bundle:
3090 	/* We found policies, but there's no bundles to instantiate:
3091 	 * either because the policy blocks, has no transformations or
3092 	 * we could not build template (no xfrm_states).*/
3093 	xdst = xfrm_create_dummy_bundle(net, xflo, fl, num_xfrms, family);
3094 	if (IS_ERR(xdst)) {
3095 		xfrm_pols_put(pols, num_pols);
3096 		return ERR_CAST(xdst);
3097 	}
3098 	xdst->num_pols = num_pols;
3099 	xdst->num_xfrms = num_xfrms;
3100 	memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
3101 
3102 	return xdst;
3103 
3104 inc_error:
3105 	XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
3106 error:
3107 	xfrm_pols_put(pols, num_pols);
3108 	return ERR_PTR(err);
3109 }
3110 
3111 static struct dst_entry *make_blackhole(struct net *net, u16 family,
3112 					struct dst_entry *dst_orig)
3113 {
3114 	const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
3115 	struct dst_entry *ret;
3116 
3117 	if (!afinfo) {
3118 		dst_release(dst_orig);
3119 		return ERR_PTR(-EINVAL);
3120 	} else {
3121 		ret = afinfo->blackhole_route(net, dst_orig);
3122 	}
3123 	rcu_read_unlock();
3124 
3125 	return ret;
3126 }
3127 
3128 /* Finds/creates a bundle for given flow and if_id
3129  *
3130  * At the moment we eat a raw IP route. Mostly to speed up lookups
3131  * on interfaces with disabled IPsec.
3132  *
3133  * xfrm_lookup uses an if_id of 0 by default, and is provided for
3134  * compatibility
3135  */
3136 struct dst_entry *xfrm_lookup_with_ifid(struct net *net,
3137 					struct dst_entry *dst_orig,
3138 					const struct flowi *fl,
3139 					const struct sock *sk,
3140 					int flags, u32 if_id)
3141 {
3142 	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
3143 	struct xfrm_dst *xdst;
3144 	struct dst_entry *dst, *route;
3145 	u16 family = dst_orig->ops->family;
3146 	u8 dir = XFRM_POLICY_OUT;
3147 	int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
3148 
3149 	dst = NULL;
3150 	xdst = NULL;
3151 	route = NULL;
3152 
3153 	sk = sk_const_to_full_sk(sk);
3154 	if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
3155 		num_pols = 1;
3156 		pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, family,
3157 						if_id);
3158 		err = xfrm_expand_policies(fl, family, pols,
3159 					   &num_pols, &num_xfrms);
3160 		if (err < 0)
3161 			goto dropdst;
3162 
3163 		if (num_pols) {
3164 			if (num_xfrms <= 0) {
3165 				drop_pols = num_pols;
3166 				goto no_transform;
3167 			}
3168 
3169 			xdst = xfrm_resolve_and_create_bundle(
3170 					pols, num_pols, fl,
3171 					family, dst_orig);
3172 
3173 			if (IS_ERR(xdst)) {
3174 				xfrm_pols_put(pols, num_pols);
3175 				err = PTR_ERR(xdst);
3176 				if (err == -EREMOTE)
3177 					goto nopol;
3178 
3179 				goto dropdst;
3180 			} else if (xdst == NULL) {
3181 				num_xfrms = 0;
3182 				drop_pols = num_pols;
3183 				goto no_transform;
3184 			}
3185 
3186 			route = xdst->route;
3187 		}
3188 	}
3189 
3190 	if (xdst == NULL) {
3191 		struct xfrm_flo xflo;
3192 
3193 		xflo.dst_orig = dst_orig;
3194 		xflo.flags = flags;
3195 
3196 		/* To accelerate a bit...  */
3197 		if (!if_id && ((dst_orig->flags & DST_NOXFRM) ||
3198 			       !net->xfrm.policy_count[XFRM_POLICY_OUT]))
3199 			goto nopol;
3200 
3201 		xdst = xfrm_bundle_lookup(net, fl, family, dir, &xflo, if_id);
3202 		if (xdst == NULL)
3203 			goto nopol;
3204 		if (IS_ERR(xdst)) {
3205 			err = PTR_ERR(xdst);
3206 			goto dropdst;
3207 		}
3208 
3209 		num_pols = xdst->num_pols;
3210 		num_xfrms = xdst->num_xfrms;
3211 		memcpy(pols, xdst->pols, sizeof(struct xfrm_policy *) * num_pols);
3212 		route = xdst->route;
3213 	}
3214 
3215 	dst = &xdst->u.dst;
3216 	if (route == NULL && num_xfrms > 0) {
3217 		/* The only case when xfrm_bundle_lookup() returns a
3218 		 * bundle with null route, is when the template could
3219 		 * not be resolved. It means policies are there, but
3220 		 * bundle could not be created, since we don't yet
3221 		 * have the xfrm_state's. We need to wait for KM to
3222 		 * negotiate new SA's or bail out with error.*/
3223 		if (net->xfrm.sysctl_larval_drop) {
3224 			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
3225 			err = -EREMOTE;
3226 			goto error;
3227 		}
3228 
3229 		err = -EAGAIN;
3230 
3231 		XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
3232 		goto error;
3233 	}
3234 
3235 no_transform:
3236 	if (num_pols == 0)
3237 		goto nopol;
3238 
3239 	if ((flags & XFRM_LOOKUP_ICMP) &&
3240 	    !(pols[0]->flags & XFRM_POLICY_ICMP)) {
3241 		err = -ENOENT;
3242 		goto error;
3243 	}
3244 
3245 	for (i = 0; i < num_pols; i++)
3246 		WRITE_ONCE(pols[i]->curlft.use_time, ktime_get_real_seconds());
3247 
3248 	if (num_xfrms < 0) {
3249 		/* Prohibit the flow */
3250 		XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLBLOCK);
3251 		err = -EPERM;
3252 		goto error;
3253 	} else if (num_xfrms > 0) {
3254 		/* Flow transformed */
3255 		dst_release(dst_orig);
3256 	} else {
3257 		/* Flow passes untransformed */
3258 		dst_release(dst);
3259 		dst = dst_orig;
3260 	}
3261 ok:
3262 	xfrm_pols_put(pols, drop_pols);
3263 	if (dst && dst->xfrm &&
3264 	    dst->xfrm->props.mode == XFRM_MODE_TUNNEL)
3265 		dst->flags |= DST_XFRM_TUNNEL;
3266 	return dst;
3267 
3268 nopol:
3269 	if ((!dst_orig->dev || !(dst_orig->dev->flags & IFF_LOOPBACK)) &&
3270 	    net->xfrm.policy_default[dir] == XFRM_USERPOLICY_BLOCK) {
3271 		err = -EPERM;
3272 		goto error;
3273 	}
3274 	if (!(flags & XFRM_LOOKUP_ICMP)) {
3275 		dst = dst_orig;
3276 		goto ok;
3277 	}
3278 	err = -ENOENT;
3279 error:
3280 	dst_release(dst);
3281 dropdst:
3282 	if (!(flags & XFRM_LOOKUP_KEEP_DST_REF))
3283 		dst_release(dst_orig);
3284 	xfrm_pols_put(pols, drop_pols);
3285 	return ERR_PTR(err);
3286 }
3287 EXPORT_SYMBOL(xfrm_lookup_with_ifid);
3288 
3289 /* Main function: finds/creates a bundle for given flow.
3290  *
3291  * At the moment we eat a raw IP route. Mostly to speed up lookups
3292  * on interfaces with disabled IPsec.
3293  */
3294 struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
3295 			      const struct flowi *fl, const struct sock *sk,
3296 			      int flags)
3297 {
3298 	return xfrm_lookup_with_ifid(net, dst_orig, fl, sk, flags, 0);
3299 }
3300 EXPORT_SYMBOL(xfrm_lookup);
3301 
3302 /* Callers of xfrm_lookup_route() must ensure a call to dst_output().
3303  * Otherwise we may send out blackholed packets.
3304  */
3305 struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
3306 				    const struct flowi *fl,
3307 				    const struct sock *sk, int flags)
3308 {
3309 	struct dst_entry *dst = xfrm_lookup(net, dst_orig, fl, sk,
3310 					    flags | XFRM_LOOKUP_QUEUE |
3311 					    XFRM_LOOKUP_KEEP_DST_REF);
3312 
3313 	if (PTR_ERR(dst) == -EREMOTE)
3314 		return make_blackhole(net, dst_orig->ops->family, dst_orig);
3315 
3316 	if (IS_ERR(dst))
3317 		dst_release(dst_orig);
3318 
3319 	return dst;
3320 }
3321 EXPORT_SYMBOL(xfrm_lookup_route);
3322 
3323 static inline int
3324 xfrm_secpath_reject(int idx, struct sk_buff *skb, const struct flowi *fl)
3325 {
3326 	struct sec_path *sp = skb_sec_path(skb);
3327 	struct xfrm_state *x;
3328 
3329 	if (!sp || idx < 0 || idx >= sp->len)
3330 		return 0;
3331 	x = sp->xvec[idx];
3332 	if (!x->type->reject)
3333 		return 0;
3334 	return x->type->reject(x, skb, fl);
3335 }
3336 
3337 /* When skb is transformed back to its "native" form, we have to
3338  * check policy restrictions. At the moment we make this in maximally
3339  * stupid way. Shame on me. :-) Of course, connected sockets must
3340  * have policy cached at them.
3341  */
3342 
3343 static inline int
3344 xfrm_state_ok(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x,
3345 	      unsigned short family, u32 if_id)
3346 {
3347 	if (xfrm_state_kern(x))
3348 		return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
3349 	return	x->id.proto == tmpl->id.proto &&
3350 		(x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
3351 		(x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
3352 		x->props.mode == tmpl->mode &&
3353 		(tmpl->allalgs || (tmpl->aalgos & (1<<x->props.aalgo)) ||
3354 		 !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
3355 		!(x->props.mode != XFRM_MODE_TRANSPORT &&
3356 		  xfrm_state_addr_cmp(tmpl, x, family)) &&
3357 		(if_id == 0 || if_id == x->if_id);
3358 }
3359 
3360 /*
3361  * 0 or more than 0 is returned when validation is succeeded (either bypass
3362  * because of optional transport mode, or next index of the matched secpath
3363  * state with the template.
3364  * -1 is returned when no matching template is found.
3365  * Otherwise "-2 - errored_index" is returned.
3366  */
3367 static inline int
3368 xfrm_policy_ok(const struct xfrm_tmpl *tmpl, const struct sec_path *sp, int start,
3369 	       unsigned short family, u32 if_id)
3370 {
3371 	int idx = start;
3372 
3373 	if (tmpl->optional) {
3374 		if (tmpl->mode == XFRM_MODE_TRANSPORT)
3375 			return start;
3376 	} else
3377 		start = -1;
3378 	for (; idx < sp->len; idx++) {
3379 		if (xfrm_state_ok(tmpl, sp->xvec[idx], family, if_id))
3380 			return ++idx;
3381 		if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
3382 			if (idx < sp->verified_cnt) {
3383 				/* Secpath entry previously verified, consider optional and
3384 				 * continue searching
3385 				 */
3386 				continue;
3387 			}
3388 
3389 			if (start == -1)
3390 				start = -2-idx;
3391 			break;
3392 		}
3393 	}
3394 	return start;
3395 }
3396 
3397 static void
3398 decode_session4(const struct xfrm_flow_keys *flkeys, struct flowi *fl, bool reverse)
3399 {
3400 	struct flowi4 *fl4 = &fl->u.ip4;
3401 
3402 	memset(fl4, 0, sizeof(struct flowi4));
3403 
3404 	if (reverse) {
3405 		fl4->saddr = flkeys->addrs.ipv4.dst;
3406 		fl4->daddr = flkeys->addrs.ipv4.src;
3407 		fl4->fl4_sport = flkeys->ports.dst;
3408 		fl4->fl4_dport = flkeys->ports.src;
3409 	} else {
3410 		fl4->saddr = flkeys->addrs.ipv4.src;
3411 		fl4->daddr = flkeys->addrs.ipv4.dst;
3412 		fl4->fl4_sport = flkeys->ports.src;
3413 		fl4->fl4_dport = flkeys->ports.dst;
3414 	}
3415 
3416 	switch (flkeys->basic.ip_proto) {
3417 	case IPPROTO_GRE:
3418 		fl4->fl4_gre_key = flkeys->gre.keyid;
3419 		break;
3420 	case IPPROTO_ICMP:
3421 		fl4->fl4_icmp_type = flkeys->icmp.type;
3422 		fl4->fl4_icmp_code = flkeys->icmp.code;
3423 		break;
3424 	}
3425 
3426 	fl4->flowi4_proto = flkeys->basic.ip_proto;
3427 	fl4->flowi4_tos = flkeys->ip.tos & ~INET_ECN_MASK;
3428 }
3429 
3430 #if IS_ENABLED(CONFIG_IPV6)
3431 static void
3432 decode_session6(const struct xfrm_flow_keys *flkeys, struct flowi *fl, bool reverse)
3433 {
3434 	struct flowi6 *fl6 = &fl->u.ip6;
3435 
3436 	memset(fl6, 0, sizeof(struct flowi6));
3437 
3438 	if (reverse) {
3439 		fl6->saddr = flkeys->addrs.ipv6.dst;
3440 		fl6->daddr = flkeys->addrs.ipv6.src;
3441 		fl6->fl6_sport = flkeys->ports.dst;
3442 		fl6->fl6_dport = flkeys->ports.src;
3443 	} else {
3444 		fl6->saddr = flkeys->addrs.ipv6.src;
3445 		fl6->daddr = flkeys->addrs.ipv6.dst;
3446 		fl6->fl6_sport = flkeys->ports.src;
3447 		fl6->fl6_dport = flkeys->ports.dst;
3448 	}
3449 
3450 	switch (flkeys->basic.ip_proto) {
3451 	case IPPROTO_GRE:
3452 		fl6->fl6_gre_key = flkeys->gre.keyid;
3453 		break;
3454 	case IPPROTO_ICMPV6:
3455 		fl6->fl6_icmp_type = flkeys->icmp.type;
3456 		fl6->fl6_icmp_code = flkeys->icmp.code;
3457 		break;
3458 	}
3459 
3460 	fl6->flowi6_proto = flkeys->basic.ip_proto;
3461 }
3462 #endif
3463 
3464 int __xfrm_decode_session(struct net *net, struct sk_buff *skb, struct flowi *fl,
3465 			  unsigned int family, int reverse)
3466 {
3467 	struct xfrm_flow_keys flkeys;
3468 
3469 	memset(&flkeys, 0, sizeof(flkeys));
3470 	__skb_flow_dissect(net, skb, &xfrm_session_dissector, &flkeys,
3471 			   NULL, 0, 0, 0, FLOW_DISSECTOR_F_STOP_AT_ENCAP);
3472 
3473 	switch (family) {
3474 	case AF_INET:
3475 		decode_session4(&flkeys, fl, reverse);
3476 		break;
3477 #if IS_ENABLED(CONFIG_IPV6)
3478 	case AF_INET6:
3479 		decode_session6(&flkeys, fl, reverse);
3480 		break;
3481 #endif
3482 	default:
3483 		return -EAFNOSUPPORT;
3484 	}
3485 
3486 	fl->flowi_mark = skb->mark;
3487 	if (reverse) {
3488 		fl->flowi_oif = skb->skb_iif;
3489 	} else {
3490 		int oif = 0;
3491 
3492 		if (skb_dst(skb) && skb_dst(skb)->dev)
3493 			oif = skb_dst(skb)->dev->ifindex;
3494 
3495 		fl->flowi_oif = oif;
3496 	}
3497 
3498 	return security_xfrm_decode_session(skb, &fl->flowi_secid);
3499 }
3500 EXPORT_SYMBOL(__xfrm_decode_session);
3501 
3502 static inline int secpath_has_nontransport(const struct sec_path *sp, int k, int *idxp)
3503 {
3504 	for (; k < sp->len; k++) {
3505 		if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
3506 			*idxp = k;
3507 			return 1;
3508 		}
3509 	}
3510 
3511 	return 0;
3512 }
3513 
3514 static bool icmp_err_packet(const struct flowi *fl, unsigned short family)
3515 {
3516 	const struct flowi4 *fl4 = &fl->u.ip4;
3517 
3518 	if (family == AF_INET &&
3519 	    fl4->flowi4_proto == IPPROTO_ICMP &&
3520 	    (fl4->fl4_icmp_type == ICMP_DEST_UNREACH ||
3521 	     fl4->fl4_icmp_type == ICMP_TIME_EXCEEDED))
3522 		return true;
3523 
3524 #if IS_ENABLED(CONFIG_IPV6)
3525 	if (family == AF_INET6) {
3526 		const struct flowi6 *fl6 = &fl->u.ip6;
3527 
3528 		if (fl6->flowi6_proto == IPPROTO_ICMPV6 &&
3529 		    (fl6->fl6_icmp_type == ICMPV6_DEST_UNREACH ||
3530 		    fl6->fl6_icmp_type == ICMPV6_PKT_TOOBIG ||
3531 		    fl6->fl6_icmp_type == ICMPV6_TIME_EXCEED))
3532 			return true;
3533 	}
3534 #endif
3535 	return false;
3536 }
3537 
3538 static bool xfrm_icmp_flow_decode(struct sk_buff *skb, unsigned short family,
3539 				  const struct flowi *fl, struct flowi *fl1)
3540 {
3541 	bool ret = true;
3542 	struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
3543 	int hl = family == AF_INET ? (sizeof(struct iphdr) +  sizeof(struct icmphdr)) :
3544 		 (sizeof(struct ipv6hdr) + sizeof(struct icmp6hdr));
3545 
3546 	if (!newskb)
3547 		return true;
3548 
3549 	if (!pskb_pull(newskb, hl))
3550 		goto out;
3551 
3552 	skb_reset_network_header(newskb);
3553 
3554 	if (xfrm_decode_session_reverse(dev_net(skb->dev), newskb, fl1, family) < 0)
3555 		goto out;
3556 
3557 	fl1->flowi_oif = fl->flowi_oif;
3558 	fl1->flowi_mark = fl->flowi_mark;
3559 	fl1->flowi_tos = fl->flowi_tos;
3560 	nf_nat_decode_session(newskb, fl1, family);
3561 	ret = false;
3562 
3563 out:
3564 	consume_skb(newskb);
3565 	return ret;
3566 }
3567 
3568 static bool xfrm_selector_inner_icmp_match(struct sk_buff *skb, unsigned short family,
3569 					   const struct xfrm_selector *sel,
3570 					   const struct flowi *fl)
3571 {
3572 	bool ret = false;
3573 
3574 	if (icmp_err_packet(fl, family)) {
3575 		struct flowi fl1;
3576 
3577 		if (xfrm_icmp_flow_decode(skb, family, fl, &fl1))
3578 			return ret;
3579 
3580 		ret = xfrm_selector_match(sel, &fl1, family);
3581 	}
3582 
3583 	return ret;
3584 }
3585 
3586 static inline struct
3587 xfrm_policy *xfrm_in_fwd_icmp(struct sk_buff *skb,
3588 			      const struct flowi *fl, unsigned short family,
3589 			      u32 if_id)
3590 {
3591 	struct xfrm_policy *pol = NULL;
3592 
3593 	if (icmp_err_packet(fl, family)) {
3594 		struct flowi fl1;
3595 		struct net *net = dev_net(skb->dev);
3596 
3597 		if (xfrm_icmp_flow_decode(skb, family, fl, &fl1))
3598 			return pol;
3599 
3600 		pol = xfrm_policy_lookup(net, &fl1, family, XFRM_POLICY_FWD, if_id);
3601 		if (IS_ERR(pol))
3602 			pol = NULL;
3603 	}
3604 
3605 	return pol;
3606 }
3607 
3608 static inline struct
3609 dst_entry *xfrm_out_fwd_icmp(struct sk_buff *skb, struct flowi *fl,
3610 			     unsigned short family, struct dst_entry *dst)
3611 {
3612 	if (icmp_err_packet(fl, family)) {
3613 		struct net *net = dev_net(skb->dev);
3614 		struct dst_entry *dst2;
3615 		struct flowi fl1;
3616 
3617 		if (xfrm_icmp_flow_decode(skb, family, fl, &fl1))
3618 			return dst;
3619 
3620 		dst_hold(dst);
3621 
3622 		dst2 = xfrm_lookup(net, dst, &fl1, NULL, (XFRM_LOOKUP_QUEUE | XFRM_LOOKUP_ICMP));
3623 
3624 		if (IS_ERR(dst2))
3625 			return dst;
3626 
3627 		if (dst2->xfrm) {
3628 			dst_release(dst);
3629 			dst = dst2;
3630 		} else {
3631 			dst_release(dst2);
3632 		}
3633 	}
3634 
3635 	return dst;
3636 }
3637 
3638 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
3639 			unsigned short family)
3640 {
3641 	struct net *net = dev_net(skb->dev);
3642 	struct xfrm_policy *pol;
3643 	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
3644 	int npols = 0;
3645 	int xfrm_nr;
3646 	int pi;
3647 	int reverse;
3648 	struct flowi fl;
3649 	int xerr_idx = -1;
3650 	const struct xfrm_if_cb *ifcb;
3651 	struct sec_path *sp;
3652 	u32 if_id = 0;
3653 
3654 	rcu_read_lock();
3655 	ifcb = xfrm_if_get_cb();
3656 
3657 	if (ifcb) {
3658 		struct xfrm_if_decode_session_result r;
3659 
3660 		if (ifcb->decode_session(skb, family, &r)) {
3661 			if_id = r.if_id;
3662 			net = r.net;
3663 		}
3664 	}
3665 	rcu_read_unlock();
3666 
3667 	reverse = dir & ~XFRM_POLICY_MASK;
3668 	dir &= XFRM_POLICY_MASK;
3669 
3670 	if (__xfrm_decode_session(net, skb, &fl, family, reverse) < 0) {
3671 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
3672 		return 0;
3673 	}
3674 
3675 	nf_nat_decode_session(skb, &fl, family);
3676 
3677 	/* First, check used SA against their selectors. */
3678 	sp = skb_sec_path(skb);
3679 	if (sp) {
3680 		int i;
3681 
3682 		for (i = sp->len - 1; i >= 0; i--) {
3683 			struct xfrm_state *x = sp->xvec[i];
3684 			int ret = 0;
3685 
3686 			if (!xfrm_selector_match(&x->sel, &fl, family)) {
3687 				ret = 1;
3688 				if (x->props.flags & XFRM_STATE_ICMP &&
3689 				    xfrm_selector_inner_icmp_match(skb, family, &x->sel, &fl))
3690 					ret = 0;
3691 				if (ret) {
3692 					XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
3693 					return 0;
3694 				}
3695 			}
3696 		}
3697 	}
3698 
3699 	pol = NULL;
3700 	sk = sk_to_full_sk(sk);
3701 	if (sk && sk->sk_policy[dir]) {
3702 		pol = xfrm_sk_policy_lookup(sk, dir, &fl, family, if_id);
3703 		if (IS_ERR(pol)) {
3704 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
3705 			return 0;
3706 		}
3707 	}
3708 
3709 	if (!pol)
3710 		pol = xfrm_policy_lookup(net, &fl, family, dir, if_id);
3711 
3712 	if (IS_ERR(pol)) {
3713 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
3714 		return 0;
3715 	}
3716 
3717 	if (!pol && dir == XFRM_POLICY_FWD)
3718 		pol = xfrm_in_fwd_icmp(skb, &fl, family, if_id);
3719 
3720 	if (!pol) {
3721 		if (net->xfrm.policy_default[dir] == XFRM_USERPOLICY_BLOCK) {
3722 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
3723 			return 0;
3724 		}
3725 
3726 		if (sp && secpath_has_nontransport(sp, 0, &xerr_idx)) {
3727 			xfrm_secpath_reject(xerr_idx, skb, &fl);
3728 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
3729 			return 0;
3730 		}
3731 		return 1;
3732 	}
3733 
3734 	/* This lockless write can happen from different cpus. */
3735 	WRITE_ONCE(pol->curlft.use_time, ktime_get_real_seconds());
3736 
3737 	pols[0] = pol;
3738 	npols++;
3739 #ifdef CONFIG_XFRM_SUB_POLICY
3740 	if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
3741 		pols[1] = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN,
3742 						    &fl, family,
3743 						    XFRM_POLICY_IN, if_id);
3744 		if (pols[1]) {
3745 			if (IS_ERR(pols[1])) {
3746 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
3747 				xfrm_pol_put(pols[0]);
3748 				return 0;
3749 			}
3750 			/* This write can happen from different cpus. */
3751 			WRITE_ONCE(pols[1]->curlft.use_time,
3752 				   ktime_get_real_seconds());
3753 			npols++;
3754 		}
3755 	}
3756 #endif
3757 
3758 	if (pol->action == XFRM_POLICY_ALLOW) {
3759 		static struct sec_path dummy;
3760 		struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
3761 		struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
3762 		struct xfrm_tmpl **tpp = tp;
3763 		int ti = 0;
3764 		int i, k;
3765 
3766 		sp = skb_sec_path(skb);
3767 		if (!sp)
3768 			sp = &dummy;
3769 
3770 		for (pi = 0; pi < npols; pi++) {
3771 			if (pols[pi] != pol &&
3772 			    pols[pi]->action != XFRM_POLICY_ALLOW) {
3773 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
3774 				goto reject;
3775 			}
3776 			if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH) {
3777 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
3778 				goto reject_error;
3779 			}
3780 			for (i = 0; i < pols[pi]->xfrm_nr; i++)
3781 				tpp[ti++] = &pols[pi]->xfrm_vec[i];
3782 		}
3783 		xfrm_nr = ti;
3784 
3785 		if (npols > 1) {
3786 			xfrm_tmpl_sort(stp, tpp, xfrm_nr, family);
3787 			tpp = stp;
3788 		}
3789 
3790 		/* For each tunnel xfrm, find the first matching tmpl.
3791 		 * For each tmpl before that, find corresponding xfrm.
3792 		 * Order is _important_. Later we will implement
3793 		 * some barriers, but at the moment barriers
3794 		 * are implied between each two transformations.
3795 		 * Upon success, marks secpath entries as having been
3796 		 * verified to allow them to be skipped in future policy
3797 		 * checks (e.g. nested tunnels).
3798 		 */
3799 		for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
3800 			k = xfrm_policy_ok(tpp[i], sp, k, family, if_id);
3801 			if (k < 0) {
3802 				if (k < -1)
3803 					/* "-2 - errored_index" returned */
3804 					xerr_idx = -(2+k);
3805 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
3806 				goto reject;
3807 			}
3808 		}
3809 
3810 		if (secpath_has_nontransport(sp, k, &xerr_idx)) {
3811 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
3812 			goto reject;
3813 		}
3814 
3815 		xfrm_pols_put(pols, npols);
3816 		sp->verified_cnt = k;
3817 
3818 		return 1;
3819 	}
3820 	XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
3821 
3822 reject:
3823 	xfrm_secpath_reject(xerr_idx, skb, &fl);
3824 reject_error:
3825 	xfrm_pols_put(pols, npols);
3826 	return 0;
3827 }
3828 EXPORT_SYMBOL(__xfrm_policy_check);
3829 
3830 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
3831 {
3832 	struct net *net = dev_net(skb->dev);
3833 	struct flowi fl;
3834 	struct dst_entry *dst;
3835 	int res = 1;
3836 
3837 	if (xfrm_decode_session(net, skb, &fl, family) < 0) {
3838 		XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
3839 		return 0;
3840 	}
3841 
3842 	skb_dst_force(skb);
3843 	if (!skb_dst(skb)) {
3844 		XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
3845 		return 0;
3846 	}
3847 
3848 	dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, XFRM_LOOKUP_QUEUE);
3849 	if (IS_ERR(dst)) {
3850 		res = 0;
3851 		dst = NULL;
3852 	}
3853 
3854 	if (dst && !dst->xfrm)
3855 		dst = xfrm_out_fwd_icmp(skb, &fl, family, dst);
3856 
3857 	skb_dst_set(skb, dst);
3858 	return res;
3859 }
3860 EXPORT_SYMBOL(__xfrm_route_forward);
3861 
3862 /* Optimize later using cookies and generation ids. */
3863 
3864 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
3865 {
3866 	/* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
3867 	 * to DST_OBSOLETE_FORCE_CHK to force all XFRM destinations to
3868 	 * get validated by dst_ops->check on every use.  We do this
3869 	 * because when a normal route referenced by an XFRM dst is
3870 	 * obsoleted we do not go looking around for all parent
3871 	 * referencing XFRM dsts so that we can invalidate them.  It
3872 	 * is just too much work.  Instead we make the checks here on
3873 	 * every use.  For example:
3874 	 *
3875 	 *	XFRM dst A --> IPv4 dst X
3876 	 *
3877 	 * X is the "xdst->route" of A (X is also the "dst->path" of A
3878 	 * in this example).  If X is marked obsolete, "A" will not
3879 	 * notice.  That's what we are validating here via the
3880 	 * stale_bundle() check.
3881 	 *
3882 	 * When a dst is removed from the fib tree, DST_OBSOLETE_DEAD will
3883 	 * be marked on it.
3884 	 * This will force stale_bundle() to fail on any xdst bundle with
3885 	 * this dst linked in it.
3886 	 */
3887 	if (dst->obsolete < 0 && !stale_bundle(dst))
3888 		return dst;
3889 
3890 	return NULL;
3891 }
3892 
3893 static int stale_bundle(struct dst_entry *dst)
3894 {
3895 	return !xfrm_bundle_ok((struct xfrm_dst *)dst);
3896 }
3897 
3898 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
3899 {
3900 	while ((dst = xfrm_dst_child(dst)) && dst->xfrm && dst->dev == dev) {
3901 		dst->dev = blackhole_netdev;
3902 		dev_hold(dst->dev);
3903 		dev_put(dev);
3904 	}
3905 }
3906 EXPORT_SYMBOL(xfrm_dst_ifdown);
3907 
3908 static void xfrm_link_failure(struct sk_buff *skb)
3909 {
3910 	/* Impossible. Such dst must be popped before reaches point of failure. */
3911 }
3912 
3913 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
3914 {
3915 	if (dst) {
3916 		if (dst->obsolete) {
3917 			dst_release(dst);
3918 			dst = NULL;
3919 		}
3920 	}
3921 	return dst;
3922 }
3923 
3924 static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr)
3925 {
3926 	while (nr--) {
3927 		struct xfrm_dst *xdst = bundle[nr];
3928 		u32 pmtu, route_mtu_cached;
3929 		struct dst_entry *dst;
3930 
3931 		dst = &xdst->u.dst;
3932 		pmtu = dst_mtu(xfrm_dst_child(dst));
3933 		xdst->child_mtu_cached = pmtu;
3934 
3935 		pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
3936 
3937 		route_mtu_cached = dst_mtu(xdst->route);
3938 		xdst->route_mtu_cached = route_mtu_cached;
3939 
3940 		if (pmtu > route_mtu_cached)
3941 			pmtu = route_mtu_cached;
3942 
3943 		dst_metric_set(dst, RTAX_MTU, pmtu);
3944 	}
3945 }
3946 
3947 /* Check that the bundle accepts the flow and its components are
3948  * still valid.
3949  */
3950 
3951 static int xfrm_bundle_ok(struct xfrm_dst *first)
3952 {
3953 	struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
3954 	struct dst_entry *dst = &first->u.dst;
3955 	struct xfrm_dst *xdst;
3956 	int start_from, nr;
3957 	u32 mtu;
3958 
3959 	if (!dst_check(xfrm_dst_path(dst), ((struct xfrm_dst *)dst)->path_cookie) ||
3960 	    (dst->dev && !netif_running(dst->dev)))
3961 		return 0;
3962 
3963 	if (dst->flags & DST_XFRM_QUEUE)
3964 		return 1;
3965 
3966 	start_from = nr = 0;
3967 	do {
3968 		struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
3969 
3970 		if (dst->xfrm->km.state != XFRM_STATE_VALID)
3971 			return 0;
3972 		if (xdst->xfrm_genid != dst->xfrm->genid)
3973 			return 0;
3974 		if (xdst->num_pols > 0 &&
3975 		    xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
3976 			return 0;
3977 
3978 		bundle[nr++] = xdst;
3979 
3980 		mtu = dst_mtu(xfrm_dst_child(dst));
3981 		if (xdst->child_mtu_cached != mtu) {
3982 			start_from = nr;
3983 			xdst->child_mtu_cached = mtu;
3984 		}
3985 
3986 		if (!dst_check(xdst->route, xdst->route_cookie))
3987 			return 0;
3988 		mtu = dst_mtu(xdst->route);
3989 		if (xdst->route_mtu_cached != mtu) {
3990 			start_from = nr;
3991 			xdst->route_mtu_cached = mtu;
3992 		}
3993 
3994 		dst = xfrm_dst_child(dst);
3995 	} while (dst->xfrm);
3996 
3997 	if (likely(!start_from))
3998 		return 1;
3999 
4000 	xdst = bundle[start_from - 1];
4001 	mtu = xdst->child_mtu_cached;
4002 	while (start_from--) {
4003 		dst = &xdst->u.dst;
4004 
4005 		mtu = xfrm_state_mtu(dst->xfrm, mtu);
4006 		if (mtu > xdst->route_mtu_cached)
4007 			mtu = xdst->route_mtu_cached;
4008 		dst_metric_set(dst, RTAX_MTU, mtu);
4009 		if (!start_from)
4010 			break;
4011 
4012 		xdst = bundle[start_from - 1];
4013 		xdst->child_mtu_cached = mtu;
4014 	}
4015 
4016 	return 1;
4017 }
4018 
4019 static unsigned int xfrm_default_advmss(const struct dst_entry *dst)
4020 {
4021 	return dst_metric_advmss(xfrm_dst_path(dst));
4022 }
4023 
4024 static unsigned int xfrm_mtu(const struct dst_entry *dst)
4025 {
4026 	unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
4027 
4028 	return mtu ? : dst_mtu(xfrm_dst_path(dst));
4029 }
4030 
4031 static const void *xfrm_get_dst_nexthop(const struct dst_entry *dst,
4032 					const void *daddr)
4033 {
4034 	while (dst->xfrm) {
4035 		const struct xfrm_state *xfrm = dst->xfrm;
4036 
4037 		dst = xfrm_dst_child(dst);
4038 
4039 		if (xfrm->props.mode == XFRM_MODE_TRANSPORT)
4040 			continue;
4041 		if (xfrm->type->flags & XFRM_TYPE_REMOTE_COADDR)
4042 			daddr = xfrm->coaddr;
4043 		else if (!(xfrm->type->flags & XFRM_TYPE_LOCAL_COADDR))
4044 			daddr = &xfrm->id.daddr;
4045 	}
4046 	return daddr;
4047 }
4048 
4049 static struct neighbour *xfrm_neigh_lookup(const struct dst_entry *dst,
4050 					   struct sk_buff *skb,
4051 					   const void *daddr)
4052 {
4053 	const struct dst_entry *path = xfrm_dst_path(dst);
4054 
4055 	if (!skb)
4056 		daddr = xfrm_get_dst_nexthop(dst, daddr);
4057 	return path->ops->neigh_lookup(path, skb, daddr);
4058 }
4059 
4060 static void xfrm_confirm_neigh(const struct dst_entry *dst, const void *daddr)
4061 {
4062 	const struct dst_entry *path = xfrm_dst_path(dst);
4063 
4064 	daddr = xfrm_get_dst_nexthop(dst, daddr);
4065 	path->ops->confirm_neigh(path, daddr);
4066 }
4067 
4068 int xfrm_policy_register_afinfo(const struct xfrm_policy_afinfo *afinfo, int family)
4069 {
4070 	int err = 0;
4071 
4072 	if (WARN_ON(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
4073 		return -EAFNOSUPPORT;
4074 
4075 	spin_lock(&xfrm_policy_afinfo_lock);
4076 	if (unlikely(xfrm_policy_afinfo[family] != NULL))
4077 		err = -EEXIST;
4078 	else {
4079 		struct dst_ops *dst_ops = afinfo->dst_ops;
4080 		if (likely(dst_ops->kmem_cachep == NULL))
4081 			dst_ops->kmem_cachep = xfrm_dst_cache;
4082 		if (likely(dst_ops->check == NULL))
4083 			dst_ops->check = xfrm_dst_check;
4084 		if (likely(dst_ops->default_advmss == NULL))
4085 			dst_ops->default_advmss = xfrm_default_advmss;
4086 		if (likely(dst_ops->mtu == NULL))
4087 			dst_ops->mtu = xfrm_mtu;
4088 		if (likely(dst_ops->negative_advice == NULL))
4089 			dst_ops->negative_advice = xfrm_negative_advice;
4090 		if (likely(dst_ops->link_failure == NULL))
4091 			dst_ops->link_failure = xfrm_link_failure;
4092 		if (likely(dst_ops->neigh_lookup == NULL))
4093 			dst_ops->neigh_lookup = xfrm_neigh_lookup;
4094 		if (likely(!dst_ops->confirm_neigh))
4095 			dst_ops->confirm_neigh = xfrm_confirm_neigh;
4096 		rcu_assign_pointer(xfrm_policy_afinfo[family], afinfo);
4097 	}
4098 	spin_unlock(&xfrm_policy_afinfo_lock);
4099 
4100 	return err;
4101 }
4102 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
4103 
4104 void xfrm_policy_unregister_afinfo(const struct xfrm_policy_afinfo *afinfo)
4105 {
4106 	struct dst_ops *dst_ops = afinfo->dst_ops;
4107 	int i;
4108 
4109 	for (i = 0; i < ARRAY_SIZE(xfrm_policy_afinfo); i++) {
4110 		if (xfrm_policy_afinfo[i] != afinfo)
4111 			continue;
4112 		RCU_INIT_POINTER(xfrm_policy_afinfo[i], NULL);
4113 		break;
4114 	}
4115 
4116 	synchronize_rcu();
4117 
4118 	dst_ops->kmem_cachep = NULL;
4119 	dst_ops->check = NULL;
4120 	dst_ops->negative_advice = NULL;
4121 	dst_ops->link_failure = NULL;
4122 }
4123 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
4124 
4125 void xfrm_if_register_cb(const struct xfrm_if_cb *ifcb)
4126 {
4127 	spin_lock(&xfrm_if_cb_lock);
4128 	rcu_assign_pointer(xfrm_if_cb, ifcb);
4129 	spin_unlock(&xfrm_if_cb_lock);
4130 }
4131 EXPORT_SYMBOL(xfrm_if_register_cb);
4132 
4133 void xfrm_if_unregister_cb(void)
4134 {
4135 	RCU_INIT_POINTER(xfrm_if_cb, NULL);
4136 	synchronize_rcu();
4137 }
4138 EXPORT_SYMBOL(xfrm_if_unregister_cb);
4139 
4140 #ifdef CONFIG_XFRM_STATISTICS
4141 static int __net_init xfrm_statistics_init(struct net *net)
4142 {
4143 	int rv;
4144 	net->mib.xfrm_statistics = alloc_percpu(struct linux_xfrm_mib);
4145 	if (!net->mib.xfrm_statistics)
4146 		return -ENOMEM;
4147 	rv = xfrm_proc_init(net);
4148 	if (rv < 0)
4149 		free_percpu(net->mib.xfrm_statistics);
4150 	return rv;
4151 }
4152 
4153 static void xfrm_statistics_fini(struct net *net)
4154 {
4155 	xfrm_proc_fini(net);
4156 	free_percpu(net->mib.xfrm_statistics);
4157 }
4158 #else
4159 static int __net_init xfrm_statistics_init(struct net *net)
4160 {
4161 	return 0;
4162 }
4163 
4164 static void xfrm_statistics_fini(struct net *net)
4165 {
4166 }
4167 #endif
4168 
4169 static int __net_init xfrm_policy_init(struct net *net)
4170 {
4171 	unsigned int hmask, sz;
4172 	int dir, err;
4173 
4174 	if (net_eq(net, &init_net)) {
4175 		xfrm_dst_cache = KMEM_CACHE(xfrm_dst, SLAB_HWCACHE_ALIGN | SLAB_PANIC);
4176 		err = rhashtable_init(&xfrm_policy_inexact_table,
4177 				      &xfrm_pol_inexact_params);
4178 		BUG_ON(err);
4179 	}
4180 
4181 	hmask = 8 - 1;
4182 	sz = (hmask+1) * sizeof(struct hlist_head);
4183 
4184 	net->xfrm.policy_byidx = xfrm_hash_alloc(sz);
4185 	if (!net->xfrm.policy_byidx)
4186 		goto out_byidx;
4187 	net->xfrm.policy_idx_hmask = hmask;
4188 
4189 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
4190 		struct xfrm_policy_hash *htab;
4191 
4192 		net->xfrm.policy_count[dir] = 0;
4193 		net->xfrm.policy_count[XFRM_POLICY_MAX + dir] = 0;
4194 		INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
4195 
4196 		htab = &net->xfrm.policy_bydst[dir];
4197 		htab->table = xfrm_hash_alloc(sz);
4198 		if (!htab->table)
4199 			goto out_bydst;
4200 		htab->hmask = hmask;
4201 		htab->dbits4 = 32;
4202 		htab->sbits4 = 32;
4203 		htab->dbits6 = 128;
4204 		htab->sbits6 = 128;
4205 	}
4206 	net->xfrm.policy_hthresh.lbits4 = 32;
4207 	net->xfrm.policy_hthresh.rbits4 = 32;
4208 	net->xfrm.policy_hthresh.lbits6 = 128;
4209 	net->xfrm.policy_hthresh.rbits6 = 128;
4210 
4211 	seqlock_init(&net->xfrm.policy_hthresh.lock);
4212 
4213 	INIT_LIST_HEAD(&net->xfrm.policy_all);
4214 	INIT_LIST_HEAD(&net->xfrm.inexact_bins);
4215 	INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
4216 	INIT_WORK(&net->xfrm.policy_hthresh.work, xfrm_hash_rebuild);
4217 	return 0;
4218 
4219 out_bydst:
4220 	for (dir--; dir >= 0; dir--) {
4221 		struct xfrm_policy_hash *htab;
4222 
4223 		htab = &net->xfrm.policy_bydst[dir];
4224 		xfrm_hash_free(htab->table, sz);
4225 	}
4226 	xfrm_hash_free(net->xfrm.policy_byidx, sz);
4227 out_byidx:
4228 	return -ENOMEM;
4229 }
4230 
4231 static void xfrm_policy_fini(struct net *net)
4232 {
4233 	struct xfrm_pol_inexact_bin *b, *t;
4234 	unsigned int sz;
4235 	int dir;
4236 
4237 	flush_work(&net->xfrm.policy_hash_work);
4238 #ifdef CONFIG_XFRM_SUB_POLICY
4239 	xfrm_policy_flush(net, XFRM_POLICY_TYPE_SUB, false);
4240 #endif
4241 	xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, false);
4242 
4243 	WARN_ON(!list_empty(&net->xfrm.policy_all));
4244 
4245 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
4246 		struct xfrm_policy_hash *htab;
4247 
4248 		WARN_ON(!hlist_empty(&net->xfrm.policy_inexact[dir]));
4249 
4250 		htab = &net->xfrm.policy_bydst[dir];
4251 		sz = (htab->hmask + 1) * sizeof(struct hlist_head);
4252 		WARN_ON(!hlist_empty(htab->table));
4253 		xfrm_hash_free(htab->table, sz);
4254 	}
4255 
4256 	sz = (net->xfrm.policy_idx_hmask + 1) * sizeof(struct hlist_head);
4257 	WARN_ON(!hlist_empty(net->xfrm.policy_byidx));
4258 	xfrm_hash_free(net->xfrm.policy_byidx, sz);
4259 
4260 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
4261 	list_for_each_entry_safe(b, t, &net->xfrm.inexact_bins, inexact_bins)
4262 		__xfrm_policy_inexact_prune_bin(b, true);
4263 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
4264 }
4265 
4266 static int __net_init xfrm_net_init(struct net *net)
4267 {
4268 	int rv;
4269 
4270 	/* Initialize the per-net locks here */
4271 	spin_lock_init(&net->xfrm.xfrm_state_lock);
4272 	spin_lock_init(&net->xfrm.xfrm_policy_lock);
4273 	seqcount_spinlock_init(&net->xfrm.xfrm_policy_hash_generation, &net->xfrm.xfrm_policy_lock);
4274 	mutex_init(&net->xfrm.xfrm_cfg_mutex);
4275 	net->xfrm.policy_default[XFRM_POLICY_IN] = XFRM_USERPOLICY_ACCEPT;
4276 	net->xfrm.policy_default[XFRM_POLICY_FWD] = XFRM_USERPOLICY_ACCEPT;
4277 	net->xfrm.policy_default[XFRM_POLICY_OUT] = XFRM_USERPOLICY_ACCEPT;
4278 
4279 	rv = xfrm_statistics_init(net);
4280 	if (rv < 0)
4281 		goto out_statistics;
4282 	rv = xfrm_state_init(net);
4283 	if (rv < 0)
4284 		goto out_state;
4285 	rv = xfrm_policy_init(net);
4286 	if (rv < 0)
4287 		goto out_policy;
4288 	rv = xfrm_sysctl_init(net);
4289 	if (rv < 0)
4290 		goto out_sysctl;
4291 
4292 	return 0;
4293 
4294 out_sysctl:
4295 	xfrm_policy_fini(net);
4296 out_policy:
4297 	xfrm_state_fini(net);
4298 out_state:
4299 	xfrm_statistics_fini(net);
4300 out_statistics:
4301 	return rv;
4302 }
4303 
4304 static void __net_exit xfrm_net_exit(struct net *net)
4305 {
4306 	xfrm_sysctl_fini(net);
4307 	xfrm_policy_fini(net);
4308 	xfrm_state_fini(net);
4309 	xfrm_statistics_fini(net);
4310 }
4311 
4312 static struct pernet_operations __net_initdata xfrm_net_ops = {
4313 	.init = xfrm_net_init,
4314 	.exit = xfrm_net_exit,
4315 };
4316 
4317 static const struct flow_dissector_key xfrm_flow_dissector_keys[] = {
4318 	{
4319 		.key_id = FLOW_DISSECTOR_KEY_CONTROL,
4320 		.offset = offsetof(struct xfrm_flow_keys, control),
4321 	},
4322 	{
4323 		.key_id = FLOW_DISSECTOR_KEY_BASIC,
4324 		.offset = offsetof(struct xfrm_flow_keys, basic),
4325 	},
4326 	{
4327 		.key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
4328 		.offset = offsetof(struct xfrm_flow_keys, addrs.ipv4),
4329 	},
4330 	{
4331 		.key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
4332 		.offset = offsetof(struct xfrm_flow_keys, addrs.ipv6),
4333 	},
4334 	{
4335 		.key_id = FLOW_DISSECTOR_KEY_PORTS,
4336 		.offset = offsetof(struct xfrm_flow_keys, ports),
4337 	},
4338 	{
4339 		.key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
4340 		.offset = offsetof(struct xfrm_flow_keys, gre),
4341 	},
4342 	{
4343 		.key_id = FLOW_DISSECTOR_KEY_IP,
4344 		.offset = offsetof(struct xfrm_flow_keys, ip),
4345 	},
4346 	{
4347 		.key_id = FLOW_DISSECTOR_KEY_ICMP,
4348 		.offset = offsetof(struct xfrm_flow_keys, icmp),
4349 	},
4350 };
4351 
4352 void __init xfrm_init(void)
4353 {
4354 	skb_flow_dissector_init(&xfrm_session_dissector,
4355 				xfrm_flow_dissector_keys,
4356 				ARRAY_SIZE(xfrm_flow_dissector_keys));
4357 
4358 	register_pernet_subsys(&xfrm_net_ops);
4359 	xfrm_dev_init();
4360 	xfrm_input_init();
4361 
4362 #ifdef CONFIG_XFRM_ESPINTCP
4363 	espintcp_init();
4364 #endif
4365 
4366 	register_xfrm_state_bpf();
4367 }
4368 
4369 #ifdef CONFIG_AUDITSYSCALL
4370 static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
4371 					 struct audit_buffer *audit_buf)
4372 {
4373 	struct xfrm_sec_ctx *ctx = xp->security;
4374 	struct xfrm_selector *sel = &xp->selector;
4375 
4376 	if (ctx)
4377 		audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
4378 				 ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str);
4379 
4380 	switch (sel->family) {
4381 	case AF_INET:
4382 		audit_log_format(audit_buf, " src=%pI4", &sel->saddr.a4);
4383 		if (sel->prefixlen_s != 32)
4384 			audit_log_format(audit_buf, " src_prefixlen=%d",
4385 					 sel->prefixlen_s);
4386 		audit_log_format(audit_buf, " dst=%pI4", &sel->daddr.a4);
4387 		if (sel->prefixlen_d != 32)
4388 			audit_log_format(audit_buf, " dst_prefixlen=%d",
4389 					 sel->prefixlen_d);
4390 		break;
4391 	case AF_INET6:
4392 		audit_log_format(audit_buf, " src=%pI6", sel->saddr.a6);
4393 		if (sel->prefixlen_s != 128)
4394 			audit_log_format(audit_buf, " src_prefixlen=%d",
4395 					 sel->prefixlen_s);
4396 		audit_log_format(audit_buf, " dst=%pI6", sel->daddr.a6);
4397 		if (sel->prefixlen_d != 128)
4398 			audit_log_format(audit_buf, " dst_prefixlen=%d",
4399 					 sel->prefixlen_d);
4400 		break;
4401 	}
4402 }
4403 
4404 void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid)
4405 {
4406 	struct audit_buffer *audit_buf;
4407 
4408 	audit_buf = xfrm_audit_start("SPD-add");
4409 	if (audit_buf == NULL)
4410 		return;
4411 	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
4412 	audit_log_format(audit_buf, " res=%u", result);
4413 	xfrm_audit_common_policyinfo(xp, audit_buf);
4414 	audit_log_end(audit_buf);
4415 }
4416 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
4417 
4418 void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
4419 			      bool task_valid)
4420 {
4421 	struct audit_buffer *audit_buf;
4422 
4423 	audit_buf = xfrm_audit_start("SPD-delete");
4424 	if (audit_buf == NULL)
4425 		return;
4426 	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
4427 	audit_log_format(audit_buf, " res=%u", result);
4428 	xfrm_audit_common_policyinfo(xp, audit_buf);
4429 	audit_log_end(audit_buf);
4430 }
4431 EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
4432 #endif
4433 
4434 #ifdef CONFIG_XFRM_MIGRATE
4435 static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp,
4436 					const struct xfrm_selector *sel_tgt)
4437 {
4438 	if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
4439 		if (sel_tgt->family == sel_cmp->family &&
4440 		    xfrm_addr_equal(&sel_tgt->daddr, &sel_cmp->daddr,
4441 				    sel_cmp->family) &&
4442 		    xfrm_addr_equal(&sel_tgt->saddr, &sel_cmp->saddr,
4443 				    sel_cmp->family) &&
4444 		    sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
4445 		    sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
4446 			return true;
4447 		}
4448 	} else {
4449 		if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
4450 			return true;
4451 		}
4452 	}
4453 	return false;
4454 }
4455 
4456 static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector *sel,
4457 						    u8 dir, u8 type, struct net *net, u32 if_id)
4458 {
4459 	struct xfrm_policy *pol, *ret = NULL;
4460 	struct hlist_head *chain;
4461 	u32 priority = ~0U;
4462 
4463 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
4464 	chain = policy_hash_direct(net, &sel->daddr, &sel->saddr, sel->family, dir);
4465 	hlist_for_each_entry(pol, chain, bydst) {
4466 		if ((if_id == 0 || pol->if_id == if_id) &&
4467 		    xfrm_migrate_selector_match(sel, &pol->selector) &&
4468 		    pol->type == type) {
4469 			ret = pol;
4470 			priority = ret->priority;
4471 			break;
4472 		}
4473 	}
4474 	chain = &net->xfrm.policy_inexact[dir];
4475 	hlist_for_each_entry(pol, chain, bydst_inexact_list) {
4476 		if ((pol->priority >= priority) && ret)
4477 			break;
4478 
4479 		if ((if_id == 0 || pol->if_id == if_id) &&
4480 		    xfrm_migrate_selector_match(sel, &pol->selector) &&
4481 		    pol->type == type) {
4482 			ret = pol;
4483 			break;
4484 		}
4485 	}
4486 
4487 	xfrm_pol_hold(ret);
4488 
4489 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
4490 
4491 	return ret;
4492 }
4493 
4494 static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t)
4495 {
4496 	int match = 0;
4497 
4498 	if (t->mode == m->mode && t->id.proto == m->proto &&
4499 	    (m->reqid == 0 || t->reqid == m->reqid)) {
4500 		switch (t->mode) {
4501 		case XFRM_MODE_TUNNEL:
4502 		case XFRM_MODE_BEET:
4503 			if (xfrm_addr_equal(&t->id.daddr, &m->old_daddr,
4504 					    m->old_family) &&
4505 			    xfrm_addr_equal(&t->saddr, &m->old_saddr,
4506 					    m->old_family)) {
4507 				match = 1;
4508 			}
4509 			break;
4510 		case XFRM_MODE_TRANSPORT:
4511 			/* in case of transport mode, template does not store
4512 			   any IP addresses, hence we just compare mode and
4513 			   protocol */
4514 			match = 1;
4515 			break;
4516 		default:
4517 			break;
4518 		}
4519 	}
4520 	return match;
4521 }
4522 
4523 /* update endpoint address(es) of template(s) */
4524 static int xfrm_policy_migrate(struct xfrm_policy *pol,
4525 			       struct xfrm_migrate *m, int num_migrate,
4526 			       struct netlink_ext_ack *extack)
4527 {
4528 	struct xfrm_migrate *mp;
4529 	int i, j, n = 0;
4530 
4531 	write_lock_bh(&pol->lock);
4532 	if (unlikely(pol->walk.dead)) {
4533 		/* target policy has been deleted */
4534 		NL_SET_ERR_MSG(extack, "Target policy not found");
4535 		write_unlock_bh(&pol->lock);
4536 		return -ENOENT;
4537 	}
4538 
4539 	for (i = 0; i < pol->xfrm_nr; i++) {
4540 		for (j = 0, mp = m; j < num_migrate; j++, mp++) {
4541 			if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
4542 				continue;
4543 			n++;
4544 			if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
4545 			    pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
4546 				continue;
4547 			/* update endpoints */
4548 			memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
4549 			       sizeof(pol->xfrm_vec[i].id.daddr));
4550 			memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
4551 			       sizeof(pol->xfrm_vec[i].saddr));
4552 			pol->xfrm_vec[i].encap_family = mp->new_family;
4553 			/* flush bundles */
4554 			atomic_inc(&pol->genid);
4555 		}
4556 	}
4557 
4558 	write_unlock_bh(&pol->lock);
4559 
4560 	if (!n)
4561 		return -ENODATA;
4562 
4563 	return 0;
4564 }
4565 
4566 static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate,
4567 			      struct netlink_ext_ack *extack)
4568 {
4569 	int i, j;
4570 
4571 	if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH) {
4572 		NL_SET_ERR_MSG(extack, "Invalid number of SAs to migrate, must be 0 < num <= XFRM_MAX_DEPTH (6)");
4573 		return -EINVAL;
4574 	}
4575 
4576 	for (i = 0; i < num_migrate; i++) {
4577 		if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
4578 		    xfrm_addr_any(&m[i].new_saddr, m[i].new_family)) {
4579 			NL_SET_ERR_MSG(extack, "Addresses in the MIGRATE attribute's list cannot be null");
4580 			return -EINVAL;
4581 		}
4582 
4583 		/* check if there is any duplicated entry */
4584 		for (j = i + 1; j < num_migrate; j++) {
4585 			if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
4586 				    sizeof(m[i].old_daddr)) &&
4587 			    !memcmp(&m[i].old_saddr, &m[j].old_saddr,
4588 				    sizeof(m[i].old_saddr)) &&
4589 			    m[i].proto == m[j].proto &&
4590 			    m[i].mode == m[j].mode &&
4591 			    m[i].reqid == m[j].reqid &&
4592 			    m[i].old_family == m[j].old_family) {
4593 				NL_SET_ERR_MSG(extack, "Entries in the MIGRATE attribute's list must be unique");
4594 				return -EINVAL;
4595 			}
4596 		}
4597 	}
4598 
4599 	return 0;
4600 }
4601 
4602 int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
4603 		 struct xfrm_migrate *m, int num_migrate,
4604 		 struct xfrm_kmaddress *k, struct net *net,
4605 		 struct xfrm_encap_tmpl *encap, u32 if_id,
4606 		 struct netlink_ext_ack *extack)
4607 {
4608 	int i, err, nx_cur = 0, nx_new = 0;
4609 	struct xfrm_policy *pol = NULL;
4610 	struct xfrm_state *x, *xc;
4611 	struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
4612 	struct xfrm_state *x_new[XFRM_MAX_DEPTH];
4613 	struct xfrm_migrate *mp;
4614 
4615 	/* Stage 0 - sanity checks */
4616 	err = xfrm_migrate_check(m, num_migrate, extack);
4617 	if (err < 0)
4618 		goto out;
4619 
4620 	if (dir >= XFRM_POLICY_MAX) {
4621 		NL_SET_ERR_MSG(extack, "Invalid policy direction");
4622 		err = -EINVAL;
4623 		goto out;
4624 	}
4625 
4626 	/* Stage 1 - find policy */
4627 	pol = xfrm_migrate_policy_find(sel, dir, type, net, if_id);
4628 	if (!pol) {
4629 		NL_SET_ERR_MSG(extack, "Target policy not found");
4630 		err = -ENOENT;
4631 		goto out;
4632 	}
4633 
4634 	/* Stage 2 - find and update state(s) */
4635 	for (i = 0, mp = m; i < num_migrate; i++, mp++) {
4636 		if ((x = xfrm_migrate_state_find(mp, net, if_id))) {
4637 			x_cur[nx_cur] = x;
4638 			nx_cur++;
4639 			xc = xfrm_state_migrate(x, mp, encap);
4640 			if (xc) {
4641 				x_new[nx_new] = xc;
4642 				nx_new++;
4643 			} else {
4644 				err = -ENODATA;
4645 				goto restore_state;
4646 			}
4647 		}
4648 	}
4649 
4650 	/* Stage 3 - update policy */
4651 	err = xfrm_policy_migrate(pol, m, num_migrate, extack);
4652 	if (err < 0)
4653 		goto restore_state;
4654 
4655 	/* Stage 4 - delete old state(s) */
4656 	if (nx_cur) {
4657 		xfrm_states_put(x_cur, nx_cur);
4658 		xfrm_states_delete(x_cur, nx_cur);
4659 	}
4660 
4661 	/* Stage 5 - announce */
4662 	km_migrate(sel, dir, type, m, num_migrate, k, encap);
4663 
4664 	xfrm_pol_put(pol);
4665 
4666 	return 0;
4667 out:
4668 	return err;
4669 
4670 restore_state:
4671 	if (pol)
4672 		xfrm_pol_put(pol);
4673 	if (nx_cur)
4674 		xfrm_states_put(x_cur, nx_cur);
4675 	if (nx_new)
4676 		xfrm_states_delete(x_new, nx_new);
4677 
4678 	return err;
4679 }
4680 EXPORT_SYMBOL(xfrm_migrate);
4681 #endif
4682