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 <net/dst.h>
33 #include <net/flow.h>
34 #include <net/inet_ecn.h>
35 #include <net/xfrm.h>
36 #include <net/ip.h>
37 #include <net/gre.h>
38 #if IS_ENABLED(CONFIG_IPV6_MIP6)
39 #include <net/mip6.h>
40 #endif
41 #ifdef CONFIG_XFRM_STATISTICS
42 #include <net/snmp.h>
43 #endif
44 #ifdef CONFIG_XFRM_ESPINTCP
45 #include <net/espintcp.h>
46 #endif
47 
48 #include "xfrm_hash.h"
49 
50 #define XFRM_QUEUE_TMO_MIN ((unsigned)(HZ/10))
51 #define XFRM_QUEUE_TMO_MAX ((unsigned)(60*HZ))
52 #define XFRM_MAX_QUEUE_LEN	100
53 
54 struct xfrm_flo {
55 	struct dst_entry *dst_orig;
56 	u8 flags;
57 };
58 
59 /* prefixes smaller than this are stored in lists, not trees. */
60 #define INEXACT_PREFIXLEN_IPV4	16
61 #define INEXACT_PREFIXLEN_IPV6	48
62 
63 struct xfrm_pol_inexact_node {
64 	struct rb_node node;
65 	union {
66 		xfrm_address_t addr;
67 		struct rcu_head rcu;
68 	};
69 	u8 prefixlen;
70 
71 	struct rb_root root;
72 
73 	/* the policies matching this node, can be empty list */
74 	struct hlist_head hhead;
75 };
76 
77 /* xfrm inexact policy search tree:
78  * xfrm_pol_inexact_bin = hash(dir,type,family,if_id);
79  *  |
80  * +---- root_d: sorted by daddr:prefix
81  * |                 |
82  * |        xfrm_pol_inexact_node
83  * |                 |
84  * |                 +- root: sorted by saddr/prefix
85  * |                 |              |
86  * |                 |         xfrm_pol_inexact_node
87  * |                 |              |
88  * |                 |              + root: unused
89  * |                 |              |
90  * |                 |              + hhead: saddr:daddr policies
91  * |                 |
92  * |                 +- coarse policies and all any:daddr policies
93  * |
94  * +---- root_s: sorted by saddr:prefix
95  * |                 |
96  * |        xfrm_pol_inexact_node
97  * |                 |
98  * |                 + root: unused
99  * |                 |
100  * |                 + hhead: saddr:any policies
101  * |
102  * +---- coarse policies and all any:any policies
103  *
104  * Lookups return four candidate lists:
105  * 1. any:any list from top-level xfrm_pol_inexact_bin
106  * 2. any:daddr list from daddr tree
107  * 3. saddr:daddr list from 2nd level daddr tree
108  * 4. saddr:any list from saddr tree
109  *
110  * This result set then needs to be searched for the policy with
111  * the lowest priority.  If two results have same prio, youngest one wins.
112  */
113 
114 struct xfrm_pol_inexact_key {
115 	possible_net_t net;
116 	u32 if_id;
117 	u16 family;
118 	u8 dir, type;
119 };
120 
121 struct xfrm_pol_inexact_bin {
122 	struct xfrm_pol_inexact_key k;
123 	struct rhash_head head;
124 	/* list containing '*:*' policies */
125 	struct hlist_head hhead;
126 
127 	seqcount_spinlock_t count;
128 	/* tree sorted by daddr/prefix */
129 	struct rb_root root_d;
130 
131 	/* tree sorted by saddr/prefix */
132 	struct rb_root root_s;
133 
134 	/* slow path below */
135 	struct list_head inexact_bins;
136 	struct rcu_head rcu;
137 };
138 
139 enum xfrm_pol_inexact_candidate_type {
140 	XFRM_POL_CAND_BOTH,
141 	XFRM_POL_CAND_SADDR,
142 	XFRM_POL_CAND_DADDR,
143 	XFRM_POL_CAND_ANY,
144 
145 	XFRM_POL_CAND_MAX,
146 };
147 
148 struct xfrm_pol_inexact_candidates {
149 	struct hlist_head *res[XFRM_POL_CAND_MAX];
150 };
151 
152 static DEFINE_SPINLOCK(xfrm_if_cb_lock);
153 static struct xfrm_if_cb const __rcu *xfrm_if_cb __read_mostly;
154 
155 static DEFINE_SPINLOCK(xfrm_policy_afinfo_lock);
156 static struct xfrm_policy_afinfo const __rcu *xfrm_policy_afinfo[AF_INET6 + 1]
157 						__read_mostly;
158 
159 static struct kmem_cache *xfrm_dst_cache __ro_after_init;
160 
161 static struct rhashtable xfrm_policy_inexact_table;
162 static const struct rhashtable_params xfrm_pol_inexact_params;
163 
164 static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr);
165 static int stale_bundle(struct dst_entry *dst);
166 static int xfrm_bundle_ok(struct xfrm_dst *xdst);
167 static void xfrm_policy_queue_process(struct timer_list *t);
168 
169 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir);
170 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
171 						int dir);
172 
173 static struct xfrm_pol_inexact_bin *
174 xfrm_policy_inexact_lookup(struct net *net, u8 type, u16 family, u8 dir,
175 			   u32 if_id);
176 
177 static struct xfrm_pol_inexact_bin *
178 xfrm_policy_inexact_lookup_rcu(struct net *net,
179 			       u8 type, u16 family, u8 dir, u32 if_id);
180 static struct xfrm_policy *
181 xfrm_policy_insert_list(struct hlist_head *chain, struct xfrm_policy *policy,
182 			bool excl);
183 static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
184 					    struct xfrm_policy *policy);
185 
186 static bool
187 xfrm_policy_find_inexact_candidates(struct xfrm_pol_inexact_candidates *cand,
188 				    struct xfrm_pol_inexact_bin *b,
189 				    const xfrm_address_t *saddr,
190 				    const xfrm_address_t *daddr);
191 
xfrm_pol_hold_rcu(struct xfrm_policy * policy)192 static inline bool xfrm_pol_hold_rcu(struct xfrm_policy *policy)
193 {
194 	return refcount_inc_not_zero(&policy->refcnt);
195 }
196 
197 static inline bool
__xfrm4_selector_match(const struct xfrm_selector * sel,const struct flowi * fl)198 __xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
199 {
200 	const struct flowi4 *fl4 = &fl->u.ip4;
201 
202 	return  addr4_match(fl4->daddr, sel->daddr.a4, sel->prefixlen_d) &&
203 		addr4_match(fl4->saddr, sel->saddr.a4, sel->prefixlen_s) &&
204 		!((xfrm_flowi_dport(fl, &fl4->uli) ^ sel->dport) & sel->dport_mask) &&
205 		!((xfrm_flowi_sport(fl, &fl4->uli) ^ sel->sport) & sel->sport_mask) &&
206 		(fl4->flowi4_proto == sel->proto || !sel->proto) &&
207 		(fl4->flowi4_oif == sel->ifindex || !sel->ifindex);
208 }
209 
210 static inline bool
__xfrm6_selector_match(const struct xfrm_selector * sel,const struct flowi * fl)211 __xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
212 {
213 	const struct flowi6 *fl6 = &fl->u.ip6;
214 
215 	return  addr_match(&fl6->daddr, &sel->daddr, sel->prefixlen_d) &&
216 		addr_match(&fl6->saddr, &sel->saddr, sel->prefixlen_s) &&
217 		!((xfrm_flowi_dport(fl, &fl6->uli) ^ sel->dport) & sel->dport_mask) &&
218 		!((xfrm_flowi_sport(fl, &fl6->uli) ^ sel->sport) & sel->sport_mask) &&
219 		(fl6->flowi6_proto == sel->proto || !sel->proto) &&
220 		(fl6->flowi6_oif == sel->ifindex || !sel->ifindex);
221 }
222 
xfrm_selector_match(const struct xfrm_selector * sel,const struct flowi * fl,unsigned short family)223 bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl,
224 			 unsigned short family)
225 {
226 	switch (family) {
227 	case AF_INET:
228 		return __xfrm4_selector_match(sel, fl);
229 	case AF_INET6:
230 		return __xfrm6_selector_match(sel, fl);
231 	}
232 	return false;
233 }
234 
xfrm_policy_get_afinfo(unsigned short family)235 static const struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
236 {
237 	const struct xfrm_policy_afinfo *afinfo;
238 
239 	if (unlikely(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
240 		return NULL;
241 	rcu_read_lock();
242 	afinfo = rcu_dereference(xfrm_policy_afinfo[family]);
243 	if (unlikely(!afinfo))
244 		rcu_read_unlock();
245 	return afinfo;
246 }
247 
248 /* Called with rcu_read_lock(). */
xfrm_if_get_cb(void)249 static const struct xfrm_if_cb *xfrm_if_get_cb(void)
250 {
251 	return rcu_dereference(xfrm_if_cb);
252 }
253 
__xfrm_dst_lookup(struct net * net,int tos,int oif,const xfrm_address_t * saddr,const xfrm_address_t * daddr,int family,u32 mark)254 struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos, int oif,
255 				    const xfrm_address_t *saddr,
256 				    const xfrm_address_t *daddr,
257 				    int family, u32 mark)
258 {
259 	const struct xfrm_policy_afinfo *afinfo;
260 	struct dst_entry *dst;
261 
262 	afinfo = xfrm_policy_get_afinfo(family);
263 	if (unlikely(afinfo == NULL))
264 		return ERR_PTR(-EAFNOSUPPORT);
265 
266 	dst = afinfo->dst_lookup(net, tos, oif, saddr, daddr, mark);
267 
268 	rcu_read_unlock();
269 
270 	return dst;
271 }
272 EXPORT_SYMBOL(__xfrm_dst_lookup);
273 
xfrm_dst_lookup(struct xfrm_state * x,int tos,int oif,xfrm_address_t * prev_saddr,xfrm_address_t * prev_daddr,int family,u32 mark)274 static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x,
275 						int tos, int oif,
276 						xfrm_address_t *prev_saddr,
277 						xfrm_address_t *prev_daddr,
278 						int family, u32 mark)
279 {
280 	struct net *net = xs_net(x);
281 	xfrm_address_t *saddr = &x->props.saddr;
282 	xfrm_address_t *daddr = &x->id.daddr;
283 	struct dst_entry *dst;
284 
285 	if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) {
286 		saddr = x->coaddr;
287 		daddr = prev_daddr;
288 	}
289 	if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) {
290 		saddr = prev_saddr;
291 		daddr = x->coaddr;
292 	}
293 
294 	dst = __xfrm_dst_lookup(net, tos, oif, saddr, daddr, family, mark);
295 
296 	if (!IS_ERR(dst)) {
297 		if (prev_saddr != saddr)
298 			memcpy(prev_saddr, saddr,  sizeof(*prev_saddr));
299 		if (prev_daddr != daddr)
300 			memcpy(prev_daddr, daddr,  sizeof(*prev_daddr));
301 	}
302 
303 	return dst;
304 }
305 
make_jiffies(long secs)306 static inline unsigned long make_jiffies(long secs)
307 {
308 	if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
309 		return MAX_SCHEDULE_TIMEOUT-1;
310 	else
311 		return secs*HZ;
312 }
313 
xfrm_policy_timer(struct timer_list * t)314 static void xfrm_policy_timer(struct timer_list *t)
315 {
316 	struct xfrm_policy *xp = from_timer(xp, t, timer);
317 	time64_t now = ktime_get_real_seconds();
318 	time64_t next = TIME64_MAX;
319 	int warn = 0;
320 	int dir;
321 
322 	read_lock(&xp->lock);
323 
324 	if (unlikely(xp->walk.dead))
325 		goto out;
326 
327 	dir = xfrm_policy_id2dir(xp->index);
328 
329 	if (xp->lft.hard_add_expires_seconds) {
330 		time64_t tmo = xp->lft.hard_add_expires_seconds +
331 			xp->curlft.add_time - now;
332 		if (tmo <= 0)
333 			goto expired;
334 		if (tmo < next)
335 			next = tmo;
336 	}
337 	if (xp->lft.hard_use_expires_seconds) {
338 		time64_t tmo = xp->lft.hard_use_expires_seconds +
339 			(xp->curlft.use_time ? : xp->curlft.add_time) - now;
340 		if (tmo <= 0)
341 			goto expired;
342 		if (tmo < next)
343 			next = tmo;
344 	}
345 	if (xp->lft.soft_add_expires_seconds) {
346 		time64_t tmo = xp->lft.soft_add_expires_seconds +
347 			xp->curlft.add_time - now;
348 		if (tmo <= 0) {
349 			warn = 1;
350 			tmo = XFRM_KM_TIMEOUT;
351 		}
352 		if (tmo < next)
353 			next = tmo;
354 	}
355 	if (xp->lft.soft_use_expires_seconds) {
356 		time64_t tmo = xp->lft.soft_use_expires_seconds +
357 			(xp->curlft.use_time ? : xp->curlft.add_time) - now;
358 		if (tmo <= 0) {
359 			warn = 1;
360 			tmo = XFRM_KM_TIMEOUT;
361 		}
362 		if (tmo < next)
363 			next = tmo;
364 	}
365 
366 	if (warn)
367 		km_policy_expired(xp, dir, 0, 0);
368 	if (next != TIME64_MAX &&
369 	    !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
370 		xfrm_pol_hold(xp);
371 
372 out:
373 	read_unlock(&xp->lock);
374 	xfrm_pol_put(xp);
375 	return;
376 
377 expired:
378 	read_unlock(&xp->lock);
379 	if (!xfrm_policy_delete(xp, dir))
380 		km_policy_expired(xp, dir, 1, 0);
381 	xfrm_pol_put(xp);
382 }
383 
384 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
385  * SPD calls.
386  */
387 
xfrm_policy_alloc(struct net * net,gfp_t gfp)388 struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
389 {
390 	struct xfrm_policy *policy;
391 
392 	policy = kzalloc(sizeof(struct xfrm_policy), gfp);
393 
394 	if (policy) {
395 		write_pnet(&policy->xp_net, net);
396 		INIT_LIST_HEAD(&policy->walk.all);
397 		INIT_HLIST_NODE(&policy->bydst_inexact_list);
398 		INIT_HLIST_NODE(&policy->bydst);
399 		INIT_HLIST_NODE(&policy->byidx);
400 		rwlock_init(&policy->lock);
401 		refcount_set(&policy->refcnt, 1);
402 		skb_queue_head_init(&policy->polq.hold_queue);
403 		timer_setup(&policy->timer, xfrm_policy_timer, 0);
404 		timer_setup(&policy->polq.hold_timer,
405 			    xfrm_policy_queue_process, 0);
406 	}
407 	return policy;
408 }
409 EXPORT_SYMBOL(xfrm_policy_alloc);
410 
xfrm_policy_destroy_rcu(struct rcu_head * head)411 static void xfrm_policy_destroy_rcu(struct rcu_head *head)
412 {
413 	struct xfrm_policy *policy = container_of(head, struct xfrm_policy, rcu);
414 
415 	security_xfrm_policy_free(policy->security);
416 	kfree(policy);
417 }
418 
419 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
420 
xfrm_policy_destroy(struct xfrm_policy * policy)421 void xfrm_policy_destroy(struct xfrm_policy *policy)
422 {
423 	BUG_ON(!policy->walk.dead);
424 
425 	if (del_timer(&policy->timer) || del_timer(&policy->polq.hold_timer))
426 		BUG();
427 
428 	call_rcu(&policy->rcu, xfrm_policy_destroy_rcu);
429 }
430 EXPORT_SYMBOL(xfrm_policy_destroy);
431 
432 /* Rule must be locked. Release descendant resources, announce
433  * entry dead. The rule must be unlinked from lists to the moment.
434  */
435 
xfrm_policy_kill(struct xfrm_policy * policy)436 static void xfrm_policy_kill(struct xfrm_policy *policy)
437 {
438 	write_lock_bh(&policy->lock);
439 	policy->walk.dead = 1;
440 	write_unlock_bh(&policy->lock);
441 
442 	atomic_inc(&policy->genid);
443 
444 	if (del_timer(&policy->polq.hold_timer))
445 		xfrm_pol_put(policy);
446 	skb_queue_purge(&policy->polq.hold_queue);
447 
448 	if (del_timer(&policy->timer))
449 		xfrm_pol_put(policy);
450 
451 	xfrm_pol_put(policy);
452 }
453 
454 static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
455 
idx_hash(struct net * net,u32 index)456 static inline unsigned int idx_hash(struct net *net, u32 index)
457 {
458 	return __idx_hash(index, net->xfrm.policy_idx_hmask);
459 }
460 
461 /* calculate policy hash thresholds */
__get_hash_thresh(struct net * net,unsigned short family,int dir,u8 * dbits,u8 * sbits)462 static void __get_hash_thresh(struct net *net,
463 			      unsigned short family, int dir,
464 			      u8 *dbits, u8 *sbits)
465 {
466 	switch (family) {
467 	case AF_INET:
468 		*dbits = net->xfrm.policy_bydst[dir].dbits4;
469 		*sbits = net->xfrm.policy_bydst[dir].sbits4;
470 		break;
471 
472 	case AF_INET6:
473 		*dbits = net->xfrm.policy_bydst[dir].dbits6;
474 		*sbits = net->xfrm.policy_bydst[dir].sbits6;
475 		break;
476 
477 	default:
478 		*dbits = 0;
479 		*sbits = 0;
480 	}
481 }
482 
policy_hash_bysel(struct net * net,const struct xfrm_selector * sel,unsigned short family,int dir)483 static struct hlist_head *policy_hash_bysel(struct net *net,
484 					    const struct xfrm_selector *sel,
485 					    unsigned short family, int dir)
486 {
487 	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
488 	unsigned int hash;
489 	u8 dbits;
490 	u8 sbits;
491 
492 	__get_hash_thresh(net, family, dir, &dbits, &sbits);
493 	hash = __sel_hash(sel, family, hmask, dbits, sbits);
494 
495 	if (hash == hmask + 1)
496 		return NULL;
497 
498 	return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
499 		     lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
500 }
501 
policy_hash_direct(struct net * net,const xfrm_address_t * daddr,const xfrm_address_t * saddr,unsigned short family,int dir)502 static struct hlist_head *policy_hash_direct(struct net *net,
503 					     const xfrm_address_t *daddr,
504 					     const xfrm_address_t *saddr,
505 					     unsigned short family, int dir)
506 {
507 	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
508 	unsigned int hash;
509 	u8 dbits;
510 	u8 sbits;
511 
512 	__get_hash_thresh(net, family, dir, &dbits, &sbits);
513 	hash = __addr_hash(daddr, saddr, family, hmask, dbits, sbits);
514 
515 	return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
516 		     lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
517 }
518 
xfrm_dst_hash_transfer(struct net * net,struct hlist_head * list,struct hlist_head * ndsttable,unsigned int nhashmask,int dir)519 static void xfrm_dst_hash_transfer(struct net *net,
520 				   struct hlist_head *list,
521 				   struct hlist_head *ndsttable,
522 				   unsigned int nhashmask,
523 				   int dir)
524 {
525 	struct hlist_node *tmp, *entry0 = NULL;
526 	struct xfrm_policy *pol;
527 	unsigned int h0 = 0;
528 	u8 dbits;
529 	u8 sbits;
530 
531 redo:
532 	hlist_for_each_entry_safe(pol, tmp, list, bydst) {
533 		unsigned int h;
534 
535 		__get_hash_thresh(net, pol->family, dir, &dbits, &sbits);
536 		h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
537 				pol->family, nhashmask, dbits, sbits);
538 		if (!entry0) {
539 			hlist_del_rcu(&pol->bydst);
540 			hlist_add_head_rcu(&pol->bydst, ndsttable + h);
541 			h0 = h;
542 		} else {
543 			if (h != h0)
544 				continue;
545 			hlist_del_rcu(&pol->bydst);
546 			hlist_add_behind_rcu(&pol->bydst, entry0);
547 		}
548 		entry0 = &pol->bydst;
549 	}
550 	if (!hlist_empty(list)) {
551 		entry0 = NULL;
552 		goto redo;
553 	}
554 }
555 
xfrm_idx_hash_transfer(struct hlist_head * list,struct hlist_head * nidxtable,unsigned int nhashmask)556 static void xfrm_idx_hash_transfer(struct hlist_head *list,
557 				   struct hlist_head *nidxtable,
558 				   unsigned int nhashmask)
559 {
560 	struct hlist_node *tmp;
561 	struct xfrm_policy *pol;
562 
563 	hlist_for_each_entry_safe(pol, tmp, list, byidx) {
564 		unsigned int h;
565 
566 		h = __idx_hash(pol->index, nhashmask);
567 		hlist_add_head(&pol->byidx, nidxtable+h);
568 	}
569 }
570 
xfrm_new_hash_mask(unsigned int old_hmask)571 static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
572 {
573 	return ((old_hmask + 1) << 1) - 1;
574 }
575 
xfrm_bydst_resize(struct net * net,int dir)576 static void xfrm_bydst_resize(struct net *net, int dir)
577 {
578 	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
579 	unsigned int nhashmask = xfrm_new_hash_mask(hmask);
580 	unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
581 	struct hlist_head *ndst = xfrm_hash_alloc(nsize);
582 	struct hlist_head *odst;
583 	int i;
584 
585 	if (!ndst)
586 		return;
587 
588 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
589 	write_seqcount_begin(&net->xfrm.xfrm_policy_hash_generation);
590 
591 	odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
592 				lockdep_is_held(&net->xfrm.xfrm_policy_lock));
593 
594 	for (i = hmask; i >= 0; i--)
595 		xfrm_dst_hash_transfer(net, odst + i, ndst, nhashmask, dir);
596 
597 	rcu_assign_pointer(net->xfrm.policy_bydst[dir].table, ndst);
598 	net->xfrm.policy_bydst[dir].hmask = nhashmask;
599 
600 	write_seqcount_end(&net->xfrm.xfrm_policy_hash_generation);
601 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
602 
603 	synchronize_rcu();
604 
605 	xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
606 }
607 
xfrm_byidx_resize(struct net * net,int total)608 static void xfrm_byidx_resize(struct net *net, int total)
609 {
610 	unsigned int hmask = net->xfrm.policy_idx_hmask;
611 	unsigned int nhashmask = xfrm_new_hash_mask(hmask);
612 	unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
613 	struct hlist_head *oidx = net->xfrm.policy_byidx;
614 	struct hlist_head *nidx = xfrm_hash_alloc(nsize);
615 	int i;
616 
617 	if (!nidx)
618 		return;
619 
620 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
621 
622 	for (i = hmask; i >= 0; i--)
623 		xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
624 
625 	net->xfrm.policy_byidx = nidx;
626 	net->xfrm.policy_idx_hmask = nhashmask;
627 
628 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
629 
630 	xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
631 }
632 
xfrm_bydst_should_resize(struct net * net,int dir,int * total)633 static inline int xfrm_bydst_should_resize(struct net *net, int dir, int *total)
634 {
635 	unsigned int cnt = net->xfrm.policy_count[dir];
636 	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
637 
638 	if (total)
639 		*total += cnt;
640 
641 	if ((hmask + 1) < xfrm_policy_hashmax &&
642 	    cnt > hmask)
643 		return 1;
644 
645 	return 0;
646 }
647 
xfrm_byidx_should_resize(struct net * net,int total)648 static inline int xfrm_byidx_should_resize(struct net *net, int total)
649 {
650 	unsigned int hmask = net->xfrm.policy_idx_hmask;
651 
652 	if ((hmask + 1) < xfrm_policy_hashmax &&
653 	    total > hmask)
654 		return 1;
655 
656 	return 0;
657 }
658 
xfrm_spd_getinfo(struct net * net,struct xfrmk_spdinfo * si)659 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
660 {
661 	si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
662 	si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
663 	si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
664 	si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
665 	si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
666 	si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
667 	si->spdhcnt = net->xfrm.policy_idx_hmask;
668 	si->spdhmcnt = xfrm_policy_hashmax;
669 }
670 EXPORT_SYMBOL(xfrm_spd_getinfo);
671 
672 static DEFINE_MUTEX(hash_resize_mutex);
xfrm_hash_resize(struct work_struct * work)673 static void xfrm_hash_resize(struct work_struct *work)
674 {
675 	struct net *net = container_of(work, struct net, xfrm.policy_hash_work);
676 	int dir, total;
677 
678 	mutex_lock(&hash_resize_mutex);
679 
680 	total = 0;
681 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
682 		if (xfrm_bydst_should_resize(net, dir, &total))
683 			xfrm_bydst_resize(net, dir);
684 	}
685 	if (xfrm_byidx_should_resize(net, total))
686 		xfrm_byidx_resize(net, total);
687 
688 	mutex_unlock(&hash_resize_mutex);
689 }
690 
691 /* Make sure *pol can be inserted into fastbin.
692  * Useful to check that later insert requests will be successful
693  * (provided xfrm_policy_lock is held throughout).
694  */
695 static struct xfrm_pol_inexact_bin *
xfrm_policy_inexact_alloc_bin(const struct xfrm_policy * pol,u8 dir)696 xfrm_policy_inexact_alloc_bin(const struct xfrm_policy *pol, u8 dir)
697 {
698 	struct xfrm_pol_inexact_bin *bin, *prev;
699 	struct xfrm_pol_inexact_key k = {
700 		.family = pol->family,
701 		.type = pol->type,
702 		.dir = dir,
703 		.if_id = pol->if_id,
704 	};
705 	struct net *net = xp_net(pol);
706 
707 	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
708 
709 	write_pnet(&k.net, net);
710 	bin = rhashtable_lookup_fast(&xfrm_policy_inexact_table, &k,
711 				     xfrm_pol_inexact_params);
712 	if (bin)
713 		return bin;
714 
715 	bin = kzalloc(sizeof(*bin), GFP_ATOMIC);
716 	if (!bin)
717 		return NULL;
718 
719 	bin->k = k;
720 	INIT_HLIST_HEAD(&bin->hhead);
721 	bin->root_d = RB_ROOT;
722 	bin->root_s = RB_ROOT;
723 	seqcount_spinlock_init(&bin->count, &net->xfrm.xfrm_policy_lock);
724 
725 	prev = rhashtable_lookup_get_insert_key(&xfrm_policy_inexact_table,
726 						&bin->k, &bin->head,
727 						xfrm_pol_inexact_params);
728 	if (!prev) {
729 		list_add(&bin->inexact_bins, &net->xfrm.inexact_bins);
730 		return bin;
731 	}
732 
733 	kfree(bin);
734 
735 	return IS_ERR(prev) ? NULL : prev;
736 }
737 
xfrm_pol_inexact_addr_use_any_list(const xfrm_address_t * addr,int family,u8 prefixlen)738 static bool xfrm_pol_inexact_addr_use_any_list(const xfrm_address_t *addr,
739 					       int family, u8 prefixlen)
740 {
741 	if (xfrm_addr_any(addr, family))
742 		return true;
743 
744 	if (family == AF_INET6 && prefixlen < INEXACT_PREFIXLEN_IPV6)
745 		return true;
746 
747 	if (family == AF_INET && prefixlen < INEXACT_PREFIXLEN_IPV4)
748 		return true;
749 
750 	return false;
751 }
752 
753 static bool
xfrm_policy_inexact_insert_use_any_list(const struct xfrm_policy * policy)754 xfrm_policy_inexact_insert_use_any_list(const struct xfrm_policy *policy)
755 {
756 	const xfrm_address_t *addr;
757 	bool saddr_any, daddr_any;
758 	u8 prefixlen;
759 
760 	addr = &policy->selector.saddr;
761 	prefixlen = policy->selector.prefixlen_s;
762 
763 	saddr_any = xfrm_pol_inexact_addr_use_any_list(addr,
764 						       policy->family,
765 						       prefixlen);
766 	addr = &policy->selector.daddr;
767 	prefixlen = policy->selector.prefixlen_d;
768 	daddr_any = xfrm_pol_inexact_addr_use_any_list(addr,
769 						       policy->family,
770 						       prefixlen);
771 	return saddr_any && daddr_any;
772 }
773 
xfrm_pol_inexact_node_init(struct xfrm_pol_inexact_node * node,const xfrm_address_t * addr,u8 prefixlen)774 static void xfrm_pol_inexact_node_init(struct xfrm_pol_inexact_node *node,
775 				       const xfrm_address_t *addr, u8 prefixlen)
776 {
777 	node->addr = *addr;
778 	node->prefixlen = prefixlen;
779 }
780 
781 static struct xfrm_pol_inexact_node *
xfrm_pol_inexact_node_alloc(const xfrm_address_t * addr,u8 prefixlen)782 xfrm_pol_inexact_node_alloc(const xfrm_address_t *addr, u8 prefixlen)
783 {
784 	struct xfrm_pol_inexact_node *node;
785 
786 	node = kzalloc(sizeof(*node), GFP_ATOMIC);
787 	if (node)
788 		xfrm_pol_inexact_node_init(node, addr, prefixlen);
789 
790 	return node;
791 }
792 
xfrm_policy_addr_delta(const xfrm_address_t * a,const xfrm_address_t * b,u8 prefixlen,u16 family)793 static int xfrm_policy_addr_delta(const xfrm_address_t *a,
794 				  const xfrm_address_t *b,
795 				  u8 prefixlen, u16 family)
796 {
797 	u32 ma, mb, mask;
798 	unsigned int pdw, pbi;
799 	int delta = 0;
800 
801 	switch (family) {
802 	case AF_INET:
803 		if (prefixlen == 0)
804 			return 0;
805 		mask = ~0U << (32 - prefixlen);
806 		ma = ntohl(a->a4) & mask;
807 		mb = ntohl(b->a4) & mask;
808 		if (ma < mb)
809 			delta = -1;
810 		else if (ma > mb)
811 			delta = 1;
812 		break;
813 	case AF_INET6:
814 		pdw = prefixlen >> 5;
815 		pbi = prefixlen & 0x1f;
816 
817 		if (pdw) {
818 			delta = memcmp(a->a6, b->a6, pdw << 2);
819 			if (delta)
820 				return delta;
821 		}
822 		if (pbi) {
823 			mask = ~0U << (32 - pbi);
824 			ma = ntohl(a->a6[pdw]) & mask;
825 			mb = ntohl(b->a6[pdw]) & mask;
826 			if (ma < mb)
827 				delta = -1;
828 			else if (ma > mb)
829 				delta = 1;
830 		}
831 		break;
832 	default:
833 		break;
834 	}
835 
836 	return delta;
837 }
838 
xfrm_policy_inexact_list_reinsert(struct net * net,struct xfrm_pol_inexact_node * n,u16 family)839 static void xfrm_policy_inexact_list_reinsert(struct net *net,
840 					      struct xfrm_pol_inexact_node *n,
841 					      u16 family)
842 {
843 	unsigned int matched_s, matched_d;
844 	struct xfrm_policy *policy, *p;
845 
846 	matched_s = 0;
847 	matched_d = 0;
848 
849 	list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
850 		struct hlist_node *newpos = NULL;
851 		bool matches_s, matches_d;
852 
853 		if (!policy->bydst_reinsert)
854 			continue;
855 
856 		WARN_ON_ONCE(policy->family != family);
857 
858 		policy->bydst_reinsert = false;
859 		hlist_for_each_entry(p, &n->hhead, bydst) {
860 			if (policy->priority > p->priority)
861 				newpos = &p->bydst;
862 			else if (policy->priority == p->priority &&
863 				 policy->pos > p->pos)
864 				newpos = &p->bydst;
865 			else
866 				break;
867 		}
868 
869 		if (newpos)
870 			hlist_add_behind_rcu(&policy->bydst, newpos);
871 		else
872 			hlist_add_head_rcu(&policy->bydst, &n->hhead);
873 
874 		/* paranoia checks follow.
875 		 * Check that the reinserted policy matches at least
876 		 * saddr or daddr for current node prefix.
877 		 *
878 		 * Matching both is fine, matching saddr in one policy
879 		 * (but not daddr) and then matching only daddr in another
880 		 * is a bug.
881 		 */
882 		matches_s = xfrm_policy_addr_delta(&policy->selector.saddr,
883 						   &n->addr,
884 						   n->prefixlen,
885 						   family) == 0;
886 		matches_d = xfrm_policy_addr_delta(&policy->selector.daddr,
887 						   &n->addr,
888 						   n->prefixlen,
889 						   family) == 0;
890 		if (matches_s && matches_d)
891 			continue;
892 
893 		WARN_ON_ONCE(!matches_s && !matches_d);
894 		if (matches_s)
895 			matched_s++;
896 		if (matches_d)
897 			matched_d++;
898 		WARN_ON_ONCE(matched_s && matched_d);
899 	}
900 }
901 
xfrm_policy_inexact_node_reinsert(struct net * net,struct xfrm_pol_inexact_node * n,struct rb_root * new,u16 family)902 static void xfrm_policy_inexact_node_reinsert(struct net *net,
903 					      struct xfrm_pol_inexact_node *n,
904 					      struct rb_root *new,
905 					      u16 family)
906 {
907 	struct xfrm_pol_inexact_node *node;
908 	struct rb_node **p, *parent;
909 
910 	/* we should not have another subtree here */
911 	WARN_ON_ONCE(!RB_EMPTY_ROOT(&n->root));
912 restart:
913 	parent = NULL;
914 	p = &new->rb_node;
915 	while (*p) {
916 		u8 prefixlen;
917 		int delta;
918 
919 		parent = *p;
920 		node = rb_entry(*p, struct xfrm_pol_inexact_node, node);
921 
922 		prefixlen = min(node->prefixlen, n->prefixlen);
923 
924 		delta = xfrm_policy_addr_delta(&n->addr, &node->addr,
925 					       prefixlen, family);
926 		if (delta < 0) {
927 			p = &parent->rb_left;
928 		} else if (delta > 0) {
929 			p = &parent->rb_right;
930 		} else {
931 			bool same_prefixlen = node->prefixlen == n->prefixlen;
932 			struct xfrm_policy *tmp;
933 
934 			hlist_for_each_entry(tmp, &n->hhead, bydst) {
935 				tmp->bydst_reinsert = true;
936 				hlist_del_rcu(&tmp->bydst);
937 			}
938 
939 			node->prefixlen = prefixlen;
940 
941 			xfrm_policy_inexact_list_reinsert(net, node, family);
942 
943 			if (same_prefixlen) {
944 				kfree_rcu(n, rcu);
945 				return;
946 			}
947 
948 			rb_erase(*p, new);
949 			kfree_rcu(n, rcu);
950 			n = node;
951 			goto restart;
952 		}
953 	}
954 
955 	rb_link_node_rcu(&n->node, parent, p);
956 	rb_insert_color(&n->node, new);
957 }
958 
959 /* merge nodes v and n */
xfrm_policy_inexact_node_merge(struct net * net,struct xfrm_pol_inexact_node * v,struct xfrm_pol_inexact_node * n,u16 family)960 static void xfrm_policy_inexact_node_merge(struct net *net,
961 					   struct xfrm_pol_inexact_node *v,
962 					   struct xfrm_pol_inexact_node *n,
963 					   u16 family)
964 {
965 	struct xfrm_pol_inexact_node *node;
966 	struct xfrm_policy *tmp;
967 	struct rb_node *rnode;
968 
969 	/* To-be-merged node v has a subtree.
970 	 *
971 	 * Dismantle it and insert its nodes to n->root.
972 	 */
973 	while ((rnode = rb_first(&v->root)) != NULL) {
974 		node = rb_entry(rnode, struct xfrm_pol_inexact_node, node);
975 		rb_erase(&node->node, &v->root);
976 		xfrm_policy_inexact_node_reinsert(net, node, &n->root,
977 						  family);
978 	}
979 
980 	hlist_for_each_entry(tmp, &v->hhead, bydst) {
981 		tmp->bydst_reinsert = true;
982 		hlist_del_rcu(&tmp->bydst);
983 	}
984 
985 	xfrm_policy_inexact_list_reinsert(net, n, family);
986 }
987 
988 static struct xfrm_pol_inexact_node *
xfrm_policy_inexact_insert_node(struct net * net,struct rb_root * root,xfrm_address_t * addr,u16 family,u8 prefixlen,u8 dir)989 xfrm_policy_inexact_insert_node(struct net *net,
990 				struct rb_root *root,
991 				xfrm_address_t *addr,
992 				u16 family, u8 prefixlen, u8 dir)
993 {
994 	struct xfrm_pol_inexact_node *cached = NULL;
995 	struct rb_node **p, *parent = NULL;
996 	struct xfrm_pol_inexact_node *node;
997 
998 	p = &root->rb_node;
999 	while (*p) {
1000 		int delta;
1001 
1002 		parent = *p;
1003 		node = rb_entry(*p, struct xfrm_pol_inexact_node, node);
1004 
1005 		delta = xfrm_policy_addr_delta(addr, &node->addr,
1006 					       node->prefixlen,
1007 					       family);
1008 		if (delta == 0 && prefixlen >= node->prefixlen) {
1009 			WARN_ON_ONCE(cached); /* ipsec policies got lost */
1010 			return node;
1011 		}
1012 
1013 		if (delta < 0)
1014 			p = &parent->rb_left;
1015 		else
1016 			p = &parent->rb_right;
1017 
1018 		if (prefixlen < node->prefixlen) {
1019 			delta = xfrm_policy_addr_delta(addr, &node->addr,
1020 						       prefixlen,
1021 						       family);
1022 			if (delta)
1023 				continue;
1024 
1025 			/* This node is a subnet of the new prefix. It needs
1026 			 * to be removed and re-inserted with the smaller
1027 			 * prefix and all nodes that are now also covered
1028 			 * by the reduced prefixlen.
1029 			 */
1030 			rb_erase(&node->node, root);
1031 
1032 			if (!cached) {
1033 				xfrm_pol_inexact_node_init(node, addr,
1034 							   prefixlen);
1035 				cached = node;
1036 			} else {
1037 				/* This node also falls within the new
1038 				 * prefixlen. Merge the to-be-reinserted
1039 				 * node and this one.
1040 				 */
1041 				xfrm_policy_inexact_node_merge(net, node,
1042 							       cached, family);
1043 				kfree_rcu(node, rcu);
1044 			}
1045 
1046 			/* restart */
1047 			p = &root->rb_node;
1048 			parent = NULL;
1049 		}
1050 	}
1051 
1052 	node = cached;
1053 	if (!node) {
1054 		node = xfrm_pol_inexact_node_alloc(addr, prefixlen);
1055 		if (!node)
1056 			return NULL;
1057 	}
1058 
1059 	rb_link_node_rcu(&node->node, parent, p);
1060 	rb_insert_color(&node->node, root);
1061 
1062 	return node;
1063 }
1064 
xfrm_policy_inexact_gc_tree(struct rb_root * r,bool rm)1065 static void xfrm_policy_inexact_gc_tree(struct rb_root *r, bool rm)
1066 {
1067 	struct xfrm_pol_inexact_node *node;
1068 	struct rb_node *rn = rb_first(r);
1069 
1070 	while (rn) {
1071 		node = rb_entry(rn, struct xfrm_pol_inexact_node, node);
1072 
1073 		xfrm_policy_inexact_gc_tree(&node->root, rm);
1074 		rn = rb_next(rn);
1075 
1076 		if (!hlist_empty(&node->hhead) || !RB_EMPTY_ROOT(&node->root)) {
1077 			WARN_ON_ONCE(rm);
1078 			continue;
1079 		}
1080 
1081 		rb_erase(&node->node, r);
1082 		kfree_rcu(node, rcu);
1083 	}
1084 }
1085 
__xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin * b,bool net_exit)1086 static void __xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin *b, bool net_exit)
1087 {
1088 	write_seqcount_begin(&b->count);
1089 	xfrm_policy_inexact_gc_tree(&b->root_d, net_exit);
1090 	xfrm_policy_inexact_gc_tree(&b->root_s, net_exit);
1091 	write_seqcount_end(&b->count);
1092 
1093 	if (!RB_EMPTY_ROOT(&b->root_d) || !RB_EMPTY_ROOT(&b->root_s) ||
1094 	    !hlist_empty(&b->hhead)) {
1095 		WARN_ON_ONCE(net_exit);
1096 		return;
1097 	}
1098 
1099 	if (rhashtable_remove_fast(&xfrm_policy_inexact_table, &b->head,
1100 				   xfrm_pol_inexact_params) == 0) {
1101 		list_del(&b->inexact_bins);
1102 		kfree_rcu(b, rcu);
1103 	}
1104 }
1105 
xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin * b)1106 static void xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin *b)
1107 {
1108 	struct net *net = read_pnet(&b->k.net);
1109 
1110 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1111 	__xfrm_policy_inexact_prune_bin(b, false);
1112 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1113 }
1114 
__xfrm_policy_inexact_flush(struct net * net)1115 static void __xfrm_policy_inexact_flush(struct net *net)
1116 {
1117 	struct xfrm_pol_inexact_bin *bin, *t;
1118 
1119 	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1120 
1121 	list_for_each_entry_safe(bin, t, &net->xfrm.inexact_bins, inexact_bins)
1122 		__xfrm_policy_inexact_prune_bin(bin, false);
1123 }
1124 
1125 static struct hlist_head *
xfrm_policy_inexact_alloc_chain(struct xfrm_pol_inexact_bin * bin,struct xfrm_policy * policy,u8 dir)1126 xfrm_policy_inexact_alloc_chain(struct xfrm_pol_inexact_bin *bin,
1127 				struct xfrm_policy *policy, u8 dir)
1128 {
1129 	struct xfrm_pol_inexact_node *n;
1130 	struct net *net;
1131 
1132 	net = xp_net(policy);
1133 	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1134 
1135 	if (xfrm_policy_inexact_insert_use_any_list(policy))
1136 		return &bin->hhead;
1137 
1138 	if (xfrm_pol_inexact_addr_use_any_list(&policy->selector.daddr,
1139 					       policy->family,
1140 					       policy->selector.prefixlen_d)) {
1141 		write_seqcount_begin(&bin->count);
1142 		n = xfrm_policy_inexact_insert_node(net,
1143 						    &bin->root_s,
1144 						    &policy->selector.saddr,
1145 						    policy->family,
1146 						    policy->selector.prefixlen_s,
1147 						    dir);
1148 		write_seqcount_end(&bin->count);
1149 		if (!n)
1150 			return NULL;
1151 
1152 		return &n->hhead;
1153 	}
1154 
1155 	/* daddr is fixed */
1156 	write_seqcount_begin(&bin->count);
1157 	n = xfrm_policy_inexact_insert_node(net,
1158 					    &bin->root_d,
1159 					    &policy->selector.daddr,
1160 					    policy->family,
1161 					    policy->selector.prefixlen_d, dir);
1162 	write_seqcount_end(&bin->count);
1163 	if (!n)
1164 		return NULL;
1165 
1166 	/* saddr is wildcard */
1167 	if (xfrm_pol_inexact_addr_use_any_list(&policy->selector.saddr,
1168 					       policy->family,
1169 					       policy->selector.prefixlen_s))
1170 		return &n->hhead;
1171 
1172 	write_seqcount_begin(&bin->count);
1173 	n = xfrm_policy_inexact_insert_node(net,
1174 					    &n->root,
1175 					    &policy->selector.saddr,
1176 					    policy->family,
1177 					    policy->selector.prefixlen_s, dir);
1178 	write_seqcount_end(&bin->count);
1179 	if (!n)
1180 		return NULL;
1181 
1182 	return &n->hhead;
1183 }
1184 
1185 static struct xfrm_policy *
xfrm_policy_inexact_insert(struct xfrm_policy * policy,u8 dir,int excl)1186 xfrm_policy_inexact_insert(struct xfrm_policy *policy, u8 dir, int excl)
1187 {
1188 	struct xfrm_pol_inexact_bin *bin;
1189 	struct xfrm_policy *delpol;
1190 	struct hlist_head *chain;
1191 	struct net *net;
1192 
1193 	bin = xfrm_policy_inexact_alloc_bin(policy, dir);
1194 	if (!bin)
1195 		return ERR_PTR(-ENOMEM);
1196 
1197 	net = xp_net(policy);
1198 	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1199 
1200 	chain = xfrm_policy_inexact_alloc_chain(bin, policy, dir);
1201 	if (!chain) {
1202 		__xfrm_policy_inexact_prune_bin(bin, false);
1203 		return ERR_PTR(-ENOMEM);
1204 	}
1205 
1206 	delpol = xfrm_policy_insert_list(chain, policy, excl);
1207 	if (delpol && excl) {
1208 		__xfrm_policy_inexact_prune_bin(bin, false);
1209 		return ERR_PTR(-EEXIST);
1210 	}
1211 
1212 	chain = &net->xfrm.policy_inexact[dir];
1213 	xfrm_policy_insert_inexact_list(chain, policy);
1214 
1215 	if (delpol)
1216 		__xfrm_policy_inexact_prune_bin(bin, false);
1217 
1218 	return delpol;
1219 }
1220 
xfrm_hash_rebuild(struct work_struct * work)1221 static void xfrm_hash_rebuild(struct work_struct *work)
1222 {
1223 	struct net *net = container_of(work, struct net,
1224 				       xfrm.policy_hthresh.work);
1225 	unsigned int hmask;
1226 	struct xfrm_policy *pol;
1227 	struct xfrm_policy *policy;
1228 	struct hlist_head *chain;
1229 	struct hlist_head *odst;
1230 	struct hlist_node *newpos;
1231 	int i;
1232 	int dir;
1233 	unsigned seq;
1234 	u8 lbits4, rbits4, lbits6, rbits6;
1235 
1236 	mutex_lock(&hash_resize_mutex);
1237 
1238 	/* read selector prefixlen thresholds */
1239 	do {
1240 		seq = read_seqbegin(&net->xfrm.policy_hthresh.lock);
1241 
1242 		lbits4 = net->xfrm.policy_hthresh.lbits4;
1243 		rbits4 = net->xfrm.policy_hthresh.rbits4;
1244 		lbits6 = net->xfrm.policy_hthresh.lbits6;
1245 		rbits6 = net->xfrm.policy_hthresh.rbits6;
1246 	} while (read_seqretry(&net->xfrm.policy_hthresh.lock, seq));
1247 
1248 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1249 	write_seqcount_begin(&net->xfrm.xfrm_policy_hash_generation);
1250 
1251 	/* make sure that we can insert the indirect policies again before
1252 	 * we start with destructive action.
1253 	 */
1254 	list_for_each_entry(policy, &net->xfrm.policy_all, walk.all) {
1255 		struct xfrm_pol_inexact_bin *bin;
1256 		u8 dbits, sbits;
1257 
1258 		dir = xfrm_policy_id2dir(policy->index);
1259 		if (policy->walk.dead || dir >= XFRM_POLICY_MAX)
1260 			continue;
1261 
1262 		if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
1263 			if (policy->family == AF_INET) {
1264 				dbits = rbits4;
1265 				sbits = lbits4;
1266 			} else {
1267 				dbits = rbits6;
1268 				sbits = lbits6;
1269 			}
1270 		} else {
1271 			if (policy->family == AF_INET) {
1272 				dbits = lbits4;
1273 				sbits = rbits4;
1274 			} else {
1275 				dbits = lbits6;
1276 				sbits = rbits6;
1277 			}
1278 		}
1279 
1280 		if (policy->selector.prefixlen_d < dbits ||
1281 		    policy->selector.prefixlen_s < sbits)
1282 			continue;
1283 
1284 		bin = xfrm_policy_inexact_alloc_bin(policy, dir);
1285 		if (!bin)
1286 			goto out_unlock;
1287 
1288 		if (!xfrm_policy_inexact_alloc_chain(bin, policy, dir))
1289 			goto out_unlock;
1290 	}
1291 
1292 	/* reset the bydst and inexact table in all directions */
1293 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
1294 		struct hlist_node *n;
1295 
1296 		hlist_for_each_entry_safe(policy, n,
1297 					  &net->xfrm.policy_inexact[dir],
1298 					  bydst_inexact_list) {
1299 			hlist_del_rcu(&policy->bydst);
1300 			hlist_del_init(&policy->bydst_inexact_list);
1301 		}
1302 
1303 		hmask = net->xfrm.policy_bydst[dir].hmask;
1304 		odst = net->xfrm.policy_bydst[dir].table;
1305 		for (i = hmask; i >= 0; i--) {
1306 			hlist_for_each_entry_safe(policy, n, odst + i, bydst)
1307 				hlist_del_rcu(&policy->bydst);
1308 		}
1309 		if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
1310 			/* dir out => dst = remote, src = local */
1311 			net->xfrm.policy_bydst[dir].dbits4 = rbits4;
1312 			net->xfrm.policy_bydst[dir].sbits4 = lbits4;
1313 			net->xfrm.policy_bydst[dir].dbits6 = rbits6;
1314 			net->xfrm.policy_bydst[dir].sbits6 = lbits6;
1315 		} else {
1316 			/* dir in/fwd => dst = local, src = remote */
1317 			net->xfrm.policy_bydst[dir].dbits4 = lbits4;
1318 			net->xfrm.policy_bydst[dir].sbits4 = rbits4;
1319 			net->xfrm.policy_bydst[dir].dbits6 = lbits6;
1320 			net->xfrm.policy_bydst[dir].sbits6 = rbits6;
1321 		}
1322 	}
1323 
1324 	/* re-insert all policies by order of creation */
1325 	list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
1326 		if (policy->walk.dead)
1327 			continue;
1328 		dir = xfrm_policy_id2dir(policy->index);
1329 		if (dir >= XFRM_POLICY_MAX) {
1330 			/* skip socket policies */
1331 			continue;
1332 		}
1333 		newpos = NULL;
1334 		chain = policy_hash_bysel(net, &policy->selector,
1335 					  policy->family, dir);
1336 
1337 		if (!chain) {
1338 			void *p = xfrm_policy_inexact_insert(policy, dir, 0);
1339 
1340 			WARN_ONCE(IS_ERR(p), "reinsert: %ld\n", PTR_ERR(p));
1341 			continue;
1342 		}
1343 
1344 		hlist_for_each_entry(pol, chain, bydst) {
1345 			if (policy->priority >= pol->priority)
1346 				newpos = &pol->bydst;
1347 			else
1348 				break;
1349 		}
1350 		if (newpos)
1351 			hlist_add_behind_rcu(&policy->bydst, newpos);
1352 		else
1353 			hlist_add_head_rcu(&policy->bydst, chain);
1354 	}
1355 
1356 out_unlock:
1357 	__xfrm_policy_inexact_flush(net);
1358 	write_seqcount_end(&net->xfrm.xfrm_policy_hash_generation);
1359 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1360 
1361 	mutex_unlock(&hash_resize_mutex);
1362 }
1363 
xfrm_policy_hash_rebuild(struct net * net)1364 void xfrm_policy_hash_rebuild(struct net *net)
1365 {
1366 	schedule_work(&net->xfrm.policy_hthresh.work);
1367 }
1368 EXPORT_SYMBOL(xfrm_policy_hash_rebuild);
1369 
1370 /* Generate new index... KAME seems to generate them ordered by cost
1371  * of an absolute inpredictability of ordering of rules. This will not pass. */
xfrm_gen_index(struct net * net,int dir,u32 index)1372 static u32 xfrm_gen_index(struct net *net, int dir, u32 index)
1373 {
1374 	static u32 idx_generator;
1375 
1376 	for (;;) {
1377 		struct hlist_head *list;
1378 		struct xfrm_policy *p;
1379 		u32 idx;
1380 		int found;
1381 
1382 		if (!index) {
1383 			idx = (idx_generator | dir);
1384 			idx_generator += 8;
1385 		} else {
1386 			idx = index;
1387 			index = 0;
1388 		}
1389 
1390 		if (idx == 0)
1391 			idx = 8;
1392 		list = net->xfrm.policy_byidx + idx_hash(net, idx);
1393 		found = 0;
1394 		hlist_for_each_entry(p, list, byidx) {
1395 			if (p->index == idx) {
1396 				found = 1;
1397 				break;
1398 			}
1399 		}
1400 		if (!found)
1401 			return idx;
1402 	}
1403 }
1404 
selector_cmp(struct xfrm_selector * s1,struct xfrm_selector * s2)1405 static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
1406 {
1407 	u32 *p1 = (u32 *) s1;
1408 	u32 *p2 = (u32 *) s2;
1409 	int len = sizeof(struct xfrm_selector) / sizeof(u32);
1410 	int i;
1411 
1412 	for (i = 0; i < len; i++) {
1413 		if (p1[i] != p2[i])
1414 			return 1;
1415 	}
1416 
1417 	return 0;
1418 }
1419 
xfrm_policy_requeue(struct xfrm_policy * old,struct xfrm_policy * new)1420 static void xfrm_policy_requeue(struct xfrm_policy *old,
1421 				struct xfrm_policy *new)
1422 {
1423 	struct xfrm_policy_queue *pq = &old->polq;
1424 	struct sk_buff_head list;
1425 
1426 	if (skb_queue_empty(&pq->hold_queue))
1427 		return;
1428 
1429 	__skb_queue_head_init(&list);
1430 
1431 	spin_lock_bh(&pq->hold_queue.lock);
1432 	skb_queue_splice_init(&pq->hold_queue, &list);
1433 	if (del_timer(&pq->hold_timer))
1434 		xfrm_pol_put(old);
1435 	spin_unlock_bh(&pq->hold_queue.lock);
1436 
1437 	pq = &new->polq;
1438 
1439 	spin_lock_bh(&pq->hold_queue.lock);
1440 	skb_queue_splice(&list, &pq->hold_queue);
1441 	pq->timeout = XFRM_QUEUE_TMO_MIN;
1442 	if (!mod_timer(&pq->hold_timer, jiffies))
1443 		xfrm_pol_hold(new);
1444 	spin_unlock_bh(&pq->hold_queue.lock);
1445 }
1446 
xfrm_policy_mark_match(const struct xfrm_mark * mark,struct xfrm_policy * pol)1447 static inline bool xfrm_policy_mark_match(const struct xfrm_mark *mark,
1448 					  struct xfrm_policy *pol)
1449 {
1450 	return mark->v == pol->mark.v && mark->m == pol->mark.m;
1451 }
1452 
xfrm_pol_bin_key(const void * data,u32 len,u32 seed)1453 static u32 xfrm_pol_bin_key(const void *data, u32 len, u32 seed)
1454 {
1455 	const struct xfrm_pol_inexact_key *k = data;
1456 	u32 a = k->type << 24 | k->dir << 16 | k->family;
1457 
1458 	return jhash_3words(a, k->if_id, net_hash_mix(read_pnet(&k->net)),
1459 			    seed);
1460 }
1461 
xfrm_pol_bin_obj(const void * data,u32 len,u32 seed)1462 static u32 xfrm_pol_bin_obj(const void *data, u32 len, u32 seed)
1463 {
1464 	const struct xfrm_pol_inexact_bin *b = data;
1465 
1466 	return xfrm_pol_bin_key(&b->k, 0, seed);
1467 }
1468 
xfrm_pol_bin_cmp(struct rhashtable_compare_arg * arg,const void * ptr)1469 static int xfrm_pol_bin_cmp(struct rhashtable_compare_arg *arg,
1470 			    const void *ptr)
1471 {
1472 	const struct xfrm_pol_inexact_key *key = arg->key;
1473 	const struct xfrm_pol_inexact_bin *b = ptr;
1474 	int ret;
1475 
1476 	if (!net_eq(read_pnet(&b->k.net), read_pnet(&key->net)))
1477 		return -1;
1478 
1479 	ret = b->k.dir ^ key->dir;
1480 	if (ret)
1481 		return ret;
1482 
1483 	ret = b->k.type ^ key->type;
1484 	if (ret)
1485 		return ret;
1486 
1487 	ret = b->k.family ^ key->family;
1488 	if (ret)
1489 		return ret;
1490 
1491 	return b->k.if_id ^ key->if_id;
1492 }
1493 
1494 static const struct rhashtable_params xfrm_pol_inexact_params = {
1495 	.head_offset		= offsetof(struct xfrm_pol_inexact_bin, head),
1496 	.hashfn			= xfrm_pol_bin_key,
1497 	.obj_hashfn		= xfrm_pol_bin_obj,
1498 	.obj_cmpfn		= xfrm_pol_bin_cmp,
1499 	.automatic_shrinking	= true,
1500 };
1501 
xfrm_policy_insert_inexact_list(struct hlist_head * chain,struct xfrm_policy * policy)1502 static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
1503 					    struct xfrm_policy *policy)
1504 {
1505 	struct xfrm_policy *pol, *delpol = NULL;
1506 	struct hlist_node *newpos = NULL;
1507 	int i = 0;
1508 
1509 	hlist_for_each_entry(pol, chain, bydst_inexact_list) {
1510 		if (pol->type == policy->type &&
1511 		    pol->if_id == policy->if_id &&
1512 		    !selector_cmp(&pol->selector, &policy->selector) &&
1513 		    xfrm_policy_mark_match(&policy->mark, pol) &&
1514 		    xfrm_sec_ctx_match(pol->security, policy->security) &&
1515 		    !WARN_ON(delpol)) {
1516 			delpol = pol;
1517 			if (policy->priority > pol->priority)
1518 				continue;
1519 		} else if (policy->priority >= pol->priority) {
1520 			newpos = &pol->bydst_inexact_list;
1521 			continue;
1522 		}
1523 		if (delpol)
1524 			break;
1525 	}
1526 
1527 	if (newpos)
1528 		hlist_add_behind_rcu(&policy->bydst_inexact_list, newpos);
1529 	else
1530 		hlist_add_head_rcu(&policy->bydst_inexact_list, chain);
1531 
1532 	hlist_for_each_entry(pol, chain, bydst_inexact_list) {
1533 		pol->pos = i;
1534 		i++;
1535 	}
1536 }
1537 
xfrm_policy_insert_list(struct hlist_head * chain,struct xfrm_policy * policy,bool excl)1538 static struct xfrm_policy *xfrm_policy_insert_list(struct hlist_head *chain,
1539 						   struct xfrm_policy *policy,
1540 						   bool excl)
1541 {
1542 	struct xfrm_policy *pol, *newpos = NULL, *delpol = NULL;
1543 
1544 	hlist_for_each_entry(pol, chain, bydst) {
1545 		if (pol->type == policy->type &&
1546 		    pol->if_id == policy->if_id &&
1547 		    !selector_cmp(&pol->selector, &policy->selector) &&
1548 		    xfrm_policy_mark_match(&policy->mark, pol) &&
1549 		    xfrm_sec_ctx_match(pol->security, policy->security) &&
1550 		    !WARN_ON(delpol)) {
1551 			if (excl)
1552 				return ERR_PTR(-EEXIST);
1553 			delpol = pol;
1554 			if (policy->priority > pol->priority)
1555 				continue;
1556 		} else if (policy->priority >= pol->priority) {
1557 			newpos = pol;
1558 			continue;
1559 		}
1560 		if (delpol)
1561 			break;
1562 	}
1563 
1564 	if (newpos)
1565 		hlist_add_behind_rcu(&policy->bydst, &newpos->bydst);
1566 	else
1567 		hlist_add_head_rcu(&policy->bydst, chain);
1568 
1569 	return delpol;
1570 }
1571 
xfrm_policy_insert(int dir,struct xfrm_policy * policy,int excl)1572 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
1573 {
1574 	struct net *net = xp_net(policy);
1575 	struct xfrm_policy *delpol;
1576 	struct hlist_head *chain;
1577 
1578 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1579 	chain = policy_hash_bysel(net, &policy->selector, policy->family, dir);
1580 	if (chain)
1581 		delpol = xfrm_policy_insert_list(chain, policy, excl);
1582 	else
1583 		delpol = xfrm_policy_inexact_insert(policy, dir, excl);
1584 
1585 	if (IS_ERR(delpol)) {
1586 		spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1587 		return PTR_ERR(delpol);
1588 	}
1589 
1590 	__xfrm_policy_link(policy, dir);
1591 
1592 	/* After previous checking, family can either be AF_INET or AF_INET6 */
1593 	if (policy->family == AF_INET)
1594 		rt_genid_bump_ipv4(net);
1595 	else
1596 		rt_genid_bump_ipv6(net);
1597 
1598 	if (delpol) {
1599 		xfrm_policy_requeue(delpol, policy);
1600 		__xfrm_policy_unlink(delpol, dir);
1601 	}
1602 	policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir, policy->index);
1603 	hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
1604 	policy->curlft.add_time = ktime_get_real_seconds();
1605 	policy->curlft.use_time = 0;
1606 	if (!mod_timer(&policy->timer, jiffies + HZ))
1607 		xfrm_pol_hold(policy);
1608 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1609 
1610 	if (delpol)
1611 		xfrm_policy_kill(delpol);
1612 	else if (xfrm_bydst_should_resize(net, dir, NULL))
1613 		schedule_work(&net->xfrm.policy_hash_work);
1614 
1615 	return 0;
1616 }
1617 EXPORT_SYMBOL(xfrm_policy_insert);
1618 
1619 static struct xfrm_policy *
__xfrm_policy_bysel_ctx(struct hlist_head * chain,const struct xfrm_mark * mark,u32 if_id,u8 type,int dir,struct xfrm_selector * sel,struct xfrm_sec_ctx * ctx)1620 __xfrm_policy_bysel_ctx(struct hlist_head *chain, const struct xfrm_mark *mark,
1621 			u32 if_id, u8 type, int dir, struct xfrm_selector *sel,
1622 			struct xfrm_sec_ctx *ctx)
1623 {
1624 	struct xfrm_policy *pol;
1625 
1626 	if (!chain)
1627 		return NULL;
1628 
1629 	hlist_for_each_entry(pol, chain, bydst) {
1630 		if (pol->type == type &&
1631 		    pol->if_id == if_id &&
1632 		    xfrm_policy_mark_match(mark, pol) &&
1633 		    !selector_cmp(sel, &pol->selector) &&
1634 		    xfrm_sec_ctx_match(ctx, pol->security))
1635 			return pol;
1636 	}
1637 
1638 	return NULL;
1639 }
1640 
1641 struct xfrm_policy *
xfrm_policy_bysel_ctx(struct net * net,const struct xfrm_mark * mark,u32 if_id,u8 type,int dir,struct xfrm_selector * sel,struct xfrm_sec_ctx * ctx,int delete,int * err)1642 xfrm_policy_bysel_ctx(struct net *net, const struct xfrm_mark *mark, u32 if_id,
1643 		      u8 type, int dir, struct xfrm_selector *sel,
1644 		      struct xfrm_sec_ctx *ctx, int delete, int *err)
1645 {
1646 	struct xfrm_pol_inexact_bin *bin = NULL;
1647 	struct xfrm_policy *pol, *ret = NULL;
1648 	struct hlist_head *chain;
1649 
1650 	*err = 0;
1651 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1652 	chain = policy_hash_bysel(net, sel, sel->family, dir);
1653 	if (!chain) {
1654 		struct xfrm_pol_inexact_candidates cand;
1655 		int i;
1656 
1657 		bin = xfrm_policy_inexact_lookup(net, type,
1658 						 sel->family, dir, if_id);
1659 		if (!bin) {
1660 			spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1661 			return NULL;
1662 		}
1663 
1664 		if (!xfrm_policy_find_inexact_candidates(&cand, bin,
1665 							 &sel->saddr,
1666 							 &sel->daddr)) {
1667 			spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1668 			return NULL;
1669 		}
1670 
1671 		pol = NULL;
1672 		for (i = 0; i < ARRAY_SIZE(cand.res); i++) {
1673 			struct xfrm_policy *tmp;
1674 
1675 			tmp = __xfrm_policy_bysel_ctx(cand.res[i], mark,
1676 						      if_id, type, dir,
1677 						      sel, ctx);
1678 			if (!tmp)
1679 				continue;
1680 
1681 			if (!pol || tmp->pos < pol->pos)
1682 				pol = tmp;
1683 		}
1684 	} else {
1685 		pol = __xfrm_policy_bysel_ctx(chain, mark, if_id, type, dir,
1686 					      sel, ctx);
1687 	}
1688 
1689 	if (pol) {
1690 		xfrm_pol_hold(pol);
1691 		if (delete) {
1692 			*err = security_xfrm_policy_delete(pol->security);
1693 			if (*err) {
1694 				spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1695 				return pol;
1696 			}
1697 			__xfrm_policy_unlink(pol, dir);
1698 		}
1699 		ret = pol;
1700 	}
1701 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1702 
1703 	if (ret && delete)
1704 		xfrm_policy_kill(ret);
1705 	if (bin && delete)
1706 		xfrm_policy_inexact_prune_bin(bin);
1707 	return ret;
1708 }
1709 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
1710 
1711 struct xfrm_policy *
xfrm_policy_byid(struct net * net,const struct xfrm_mark * mark,u32 if_id,u8 type,int dir,u32 id,int delete,int * err)1712 xfrm_policy_byid(struct net *net, const struct xfrm_mark *mark, u32 if_id,
1713 		 u8 type, int dir, u32 id, int delete, int *err)
1714 {
1715 	struct xfrm_policy *pol, *ret;
1716 	struct hlist_head *chain;
1717 
1718 	*err = -ENOENT;
1719 	if (xfrm_policy_id2dir(id) != dir)
1720 		return NULL;
1721 
1722 	*err = 0;
1723 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1724 	chain = net->xfrm.policy_byidx + idx_hash(net, id);
1725 	ret = NULL;
1726 	hlist_for_each_entry(pol, chain, byidx) {
1727 		if (pol->type == type && pol->index == id &&
1728 		    pol->if_id == if_id && xfrm_policy_mark_match(mark, pol)) {
1729 			xfrm_pol_hold(pol);
1730 			if (delete) {
1731 				*err = security_xfrm_policy_delete(
1732 								pol->security);
1733 				if (*err) {
1734 					spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1735 					return pol;
1736 				}
1737 				__xfrm_policy_unlink(pol, dir);
1738 			}
1739 			ret = pol;
1740 			break;
1741 		}
1742 	}
1743 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1744 
1745 	if (ret && delete)
1746 		xfrm_policy_kill(ret);
1747 	return ret;
1748 }
1749 EXPORT_SYMBOL(xfrm_policy_byid);
1750 
1751 #ifdef CONFIG_SECURITY_NETWORK_XFRM
1752 static inline int
xfrm_policy_flush_secctx_check(struct net * net,u8 type,bool task_valid)1753 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
1754 {
1755 	struct xfrm_policy *pol;
1756 	int err = 0;
1757 
1758 	list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
1759 		if (pol->walk.dead ||
1760 		    xfrm_policy_id2dir(pol->index) >= XFRM_POLICY_MAX ||
1761 		    pol->type != type)
1762 			continue;
1763 
1764 		err = security_xfrm_policy_delete(pol->security);
1765 		if (err) {
1766 			xfrm_audit_policy_delete(pol, 0, task_valid);
1767 			return err;
1768 		}
1769 	}
1770 	return err;
1771 }
1772 #else
1773 static inline int
xfrm_policy_flush_secctx_check(struct net * net,u8 type,bool task_valid)1774 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
1775 {
1776 	return 0;
1777 }
1778 #endif
1779 
xfrm_policy_flush(struct net * net,u8 type,bool task_valid)1780 int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
1781 {
1782 	int dir, err = 0, cnt = 0;
1783 	struct xfrm_policy *pol;
1784 
1785 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1786 
1787 	err = xfrm_policy_flush_secctx_check(net, type, task_valid);
1788 	if (err)
1789 		goto out;
1790 
1791 again:
1792 	list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
1793 		dir = xfrm_policy_id2dir(pol->index);
1794 		if (pol->walk.dead ||
1795 		    dir >= XFRM_POLICY_MAX ||
1796 		    pol->type != type)
1797 			continue;
1798 
1799 		__xfrm_policy_unlink(pol, dir);
1800 		spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1801 		cnt++;
1802 		xfrm_audit_policy_delete(pol, 1, task_valid);
1803 		xfrm_policy_kill(pol);
1804 		spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1805 		goto again;
1806 	}
1807 	if (cnt)
1808 		__xfrm_policy_inexact_flush(net);
1809 	else
1810 		err = -ESRCH;
1811 out:
1812 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1813 	return err;
1814 }
1815 EXPORT_SYMBOL(xfrm_policy_flush);
1816 
xfrm_policy_walk(struct net * net,struct xfrm_policy_walk * walk,int (* func)(struct xfrm_policy *,int,int,void *),void * data)1817 int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
1818 		     int (*func)(struct xfrm_policy *, int, int, void*),
1819 		     void *data)
1820 {
1821 	struct xfrm_policy *pol;
1822 	struct xfrm_policy_walk_entry *x;
1823 	int error = 0;
1824 
1825 	if (walk->type >= XFRM_POLICY_TYPE_MAX &&
1826 	    walk->type != XFRM_POLICY_TYPE_ANY)
1827 		return -EINVAL;
1828 
1829 	if (list_empty(&walk->walk.all) && walk->seq != 0)
1830 		return 0;
1831 
1832 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1833 	if (list_empty(&walk->walk.all))
1834 		x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
1835 	else
1836 		x = list_first_entry(&walk->walk.all,
1837 				     struct xfrm_policy_walk_entry, all);
1838 
1839 	list_for_each_entry_from(x, &net->xfrm.policy_all, all) {
1840 		if (x->dead)
1841 			continue;
1842 		pol = container_of(x, struct xfrm_policy, walk);
1843 		if (walk->type != XFRM_POLICY_TYPE_ANY &&
1844 		    walk->type != pol->type)
1845 			continue;
1846 		error = func(pol, xfrm_policy_id2dir(pol->index),
1847 			     walk->seq, data);
1848 		if (error) {
1849 			list_move_tail(&walk->walk.all, &x->all);
1850 			goto out;
1851 		}
1852 		walk->seq++;
1853 	}
1854 	if (walk->seq == 0) {
1855 		error = -ENOENT;
1856 		goto out;
1857 	}
1858 	list_del_init(&walk->walk.all);
1859 out:
1860 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1861 	return error;
1862 }
1863 EXPORT_SYMBOL(xfrm_policy_walk);
1864 
xfrm_policy_walk_init(struct xfrm_policy_walk * walk,u8 type)1865 void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type)
1866 {
1867 	INIT_LIST_HEAD(&walk->walk.all);
1868 	walk->walk.dead = 1;
1869 	walk->type = type;
1870 	walk->seq = 0;
1871 }
1872 EXPORT_SYMBOL(xfrm_policy_walk_init);
1873 
xfrm_policy_walk_done(struct xfrm_policy_walk * walk,struct net * net)1874 void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net)
1875 {
1876 	if (list_empty(&walk->walk.all))
1877 		return;
1878 
1879 	spin_lock_bh(&net->xfrm.xfrm_policy_lock); /*FIXME where is net? */
1880 	list_del(&walk->walk.all);
1881 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1882 }
1883 EXPORT_SYMBOL(xfrm_policy_walk_done);
1884 
1885 /*
1886  * Find policy to apply to this flow.
1887  *
1888  * Returns 0 if policy found, else an -errno.
1889  */
xfrm_policy_match(const struct xfrm_policy * pol,const struct flowi * fl,u8 type,u16 family,int dir,u32 if_id)1890 static int xfrm_policy_match(const struct xfrm_policy *pol,
1891 			     const struct flowi *fl,
1892 			     u8 type, u16 family, int dir, u32 if_id)
1893 {
1894 	const struct xfrm_selector *sel = &pol->selector;
1895 	int ret = -ESRCH;
1896 	bool match;
1897 
1898 	if (pol->family != family ||
1899 	    pol->if_id != if_id ||
1900 	    (fl->flowi_mark & pol->mark.m) != pol->mark.v ||
1901 	    pol->type != type)
1902 		return ret;
1903 
1904 	match = xfrm_selector_match(sel, fl, family);
1905 	if (match)
1906 		ret = security_xfrm_policy_lookup(pol->security, fl->flowi_secid);
1907 	return ret;
1908 }
1909 
1910 static struct xfrm_pol_inexact_node *
xfrm_policy_lookup_inexact_addr(const struct rb_root * r,seqcount_spinlock_t * count,const xfrm_address_t * addr,u16 family)1911 xfrm_policy_lookup_inexact_addr(const struct rb_root *r,
1912 				seqcount_spinlock_t *count,
1913 				const xfrm_address_t *addr, u16 family)
1914 {
1915 	const struct rb_node *parent;
1916 	int seq;
1917 
1918 again:
1919 	seq = read_seqcount_begin(count);
1920 
1921 	parent = rcu_dereference_raw(r->rb_node);
1922 	while (parent) {
1923 		struct xfrm_pol_inexact_node *node;
1924 		int delta;
1925 
1926 		node = rb_entry(parent, struct xfrm_pol_inexact_node, node);
1927 
1928 		delta = xfrm_policy_addr_delta(addr, &node->addr,
1929 					       node->prefixlen, family);
1930 		if (delta < 0) {
1931 			parent = rcu_dereference_raw(parent->rb_left);
1932 			continue;
1933 		} else if (delta > 0) {
1934 			parent = rcu_dereference_raw(parent->rb_right);
1935 			continue;
1936 		}
1937 
1938 		return node;
1939 	}
1940 
1941 	if (read_seqcount_retry(count, seq))
1942 		goto again;
1943 
1944 	return NULL;
1945 }
1946 
1947 static bool
xfrm_policy_find_inexact_candidates(struct xfrm_pol_inexact_candidates * cand,struct xfrm_pol_inexact_bin * b,const xfrm_address_t * saddr,const xfrm_address_t * daddr)1948 xfrm_policy_find_inexact_candidates(struct xfrm_pol_inexact_candidates *cand,
1949 				    struct xfrm_pol_inexact_bin *b,
1950 				    const xfrm_address_t *saddr,
1951 				    const xfrm_address_t *daddr)
1952 {
1953 	struct xfrm_pol_inexact_node *n;
1954 	u16 family;
1955 
1956 	if (!b)
1957 		return false;
1958 
1959 	family = b->k.family;
1960 	memset(cand, 0, sizeof(*cand));
1961 	cand->res[XFRM_POL_CAND_ANY] = &b->hhead;
1962 
1963 	n = xfrm_policy_lookup_inexact_addr(&b->root_d, &b->count, daddr,
1964 					    family);
1965 	if (n) {
1966 		cand->res[XFRM_POL_CAND_DADDR] = &n->hhead;
1967 		n = xfrm_policy_lookup_inexact_addr(&n->root, &b->count, saddr,
1968 						    family);
1969 		if (n)
1970 			cand->res[XFRM_POL_CAND_BOTH] = &n->hhead;
1971 	}
1972 
1973 	n = xfrm_policy_lookup_inexact_addr(&b->root_s, &b->count, saddr,
1974 					    family);
1975 	if (n)
1976 		cand->res[XFRM_POL_CAND_SADDR] = &n->hhead;
1977 
1978 	return true;
1979 }
1980 
1981 static struct xfrm_pol_inexact_bin *
xfrm_policy_inexact_lookup_rcu(struct net * net,u8 type,u16 family,u8 dir,u32 if_id)1982 xfrm_policy_inexact_lookup_rcu(struct net *net, u8 type, u16 family,
1983 			       u8 dir, u32 if_id)
1984 {
1985 	struct xfrm_pol_inexact_key k = {
1986 		.family = family,
1987 		.type = type,
1988 		.dir = dir,
1989 		.if_id = if_id,
1990 	};
1991 
1992 	write_pnet(&k.net, net);
1993 
1994 	return rhashtable_lookup(&xfrm_policy_inexact_table, &k,
1995 				 xfrm_pol_inexact_params);
1996 }
1997 
1998 static struct xfrm_pol_inexact_bin *
xfrm_policy_inexact_lookup(struct net * net,u8 type,u16 family,u8 dir,u32 if_id)1999 xfrm_policy_inexact_lookup(struct net *net, u8 type, u16 family,
2000 			   u8 dir, u32 if_id)
2001 {
2002 	struct xfrm_pol_inexact_bin *bin;
2003 
2004 	lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
2005 
2006 	rcu_read_lock();
2007 	bin = xfrm_policy_inexact_lookup_rcu(net, type, family, dir, if_id);
2008 	rcu_read_unlock();
2009 
2010 	return bin;
2011 }
2012 
2013 static struct xfrm_policy *
__xfrm_policy_eval_candidates(struct hlist_head * chain,struct xfrm_policy * prefer,const struct flowi * fl,u8 type,u16 family,int dir,u32 if_id)2014 __xfrm_policy_eval_candidates(struct hlist_head *chain,
2015 			      struct xfrm_policy *prefer,
2016 			      const struct flowi *fl,
2017 			      u8 type, u16 family, int dir, u32 if_id)
2018 {
2019 	u32 priority = prefer ? prefer->priority : ~0u;
2020 	struct xfrm_policy *pol;
2021 
2022 	if (!chain)
2023 		return NULL;
2024 
2025 	hlist_for_each_entry_rcu(pol, chain, bydst) {
2026 		int err;
2027 
2028 		if (pol->priority > priority)
2029 			break;
2030 
2031 		err = xfrm_policy_match(pol, fl, type, family, dir, if_id);
2032 		if (err) {
2033 			if (err != -ESRCH)
2034 				return ERR_PTR(err);
2035 
2036 			continue;
2037 		}
2038 
2039 		if (prefer) {
2040 			/* matches.  Is it older than *prefer? */
2041 			if (pol->priority == priority &&
2042 			    prefer->pos < pol->pos)
2043 				return prefer;
2044 		}
2045 
2046 		return pol;
2047 	}
2048 
2049 	return NULL;
2050 }
2051 
2052 static struct xfrm_policy *
xfrm_policy_eval_candidates(struct xfrm_pol_inexact_candidates * cand,struct xfrm_policy * prefer,const struct flowi * fl,u8 type,u16 family,int dir,u32 if_id)2053 xfrm_policy_eval_candidates(struct xfrm_pol_inexact_candidates *cand,
2054 			    struct xfrm_policy *prefer,
2055 			    const struct flowi *fl,
2056 			    u8 type, u16 family, int dir, u32 if_id)
2057 {
2058 	struct xfrm_policy *tmp;
2059 	int i;
2060 
2061 	for (i = 0; i < ARRAY_SIZE(cand->res); i++) {
2062 		tmp = __xfrm_policy_eval_candidates(cand->res[i],
2063 						    prefer,
2064 						    fl, type, family, dir,
2065 						    if_id);
2066 		if (!tmp)
2067 			continue;
2068 
2069 		if (IS_ERR(tmp))
2070 			return tmp;
2071 		prefer = tmp;
2072 	}
2073 
2074 	return prefer;
2075 }
2076 
xfrm_policy_lookup_bytype(struct net * net,u8 type,const struct flowi * fl,u16 family,u8 dir,u32 if_id)2077 static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
2078 						     const struct flowi *fl,
2079 						     u16 family, u8 dir,
2080 						     u32 if_id)
2081 {
2082 	struct xfrm_pol_inexact_candidates cand;
2083 	const xfrm_address_t *daddr, *saddr;
2084 	struct xfrm_pol_inexact_bin *bin;
2085 	struct xfrm_policy *pol, *ret;
2086 	struct hlist_head *chain;
2087 	unsigned int sequence;
2088 	int err;
2089 
2090 	daddr = xfrm_flowi_daddr(fl, family);
2091 	saddr = xfrm_flowi_saddr(fl, family);
2092 	if (unlikely(!daddr || !saddr))
2093 		return NULL;
2094 
2095 	rcu_read_lock();
2096  retry:
2097 	do {
2098 		sequence = read_seqcount_begin(&net->xfrm.xfrm_policy_hash_generation);
2099 		chain = policy_hash_direct(net, daddr, saddr, family, dir);
2100 	} while (read_seqcount_retry(&net->xfrm.xfrm_policy_hash_generation, sequence));
2101 
2102 	ret = NULL;
2103 	hlist_for_each_entry_rcu(pol, chain, bydst) {
2104 		err = xfrm_policy_match(pol, fl, type, family, dir, if_id);
2105 		if (err) {
2106 			if (err == -ESRCH)
2107 				continue;
2108 			else {
2109 				ret = ERR_PTR(err);
2110 				goto fail;
2111 			}
2112 		} else {
2113 			ret = pol;
2114 			break;
2115 		}
2116 	}
2117 	bin = xfrm_policy_inexact_lookup_rcu(net, type, family, dir, if_id);
2118 	if (!bin || !xfrm_policy_find_inexact_candidates(&cand, bin, saddr,
2119 							 daddr))
2120 		goto skip_inexact;
2121 
2122 	pol = xfrm_policy_eval_candidates(&cand, ret, fl, type,
2123 					  family, dir, if_id);
2124 	if (pol) {
2125 		ret = pol;
2126 		if (IS_ERR(pol))
2127 			goto fail;
2128 	}
2129 
2130 skip_inexact:
2131 	if (read_seqcount_retry(&net->xfrm.xfrm_policy_hash_generation, sequence))
2132 		goto retry;
2133 
2134 	if (ret && !xfrm_pol_hold_rcu(ret))
2135 		goto retry;
2136 fail:
2137 	rcu_read_unlock();
2138 
2139 	return ret;
2140 }
2141 
xfrm_policy_lookup(struct net * net,const struct flowi * fl,u16 family,u8 dir,u32 if_id)2142 static struct xfrm_policy *xfrm_policy_lookup(struct net *net,
2143 					      const struct flowi *fl,
2144 					      u16 family, u8 dir, u32 if_id)
2145 {
2146 #ifdef CONFIG_XFRM_SUB_POLICY
2147 	struct xfrm_policy *pol;
2148 
2149 	pol = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_SUB, fl, family,
2150 					dir, if_id);
2151 	if (pol != NULL)
2152 		return pol;
2153 #endif
2154 	return xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, fl, family,
2155 					 dir, if_id);
2156 }
2157 
xfrm_sk_policy_lookup(const struct sock * sk,int dir,const struct flowi * fl,u16 family,u32 if_id)2158 static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir,
2159 						 const struct flowi *fl,
2160 						 u16 family, u32 if_id)
2161 {
2162 	struct xfrm_policy *pol;
2163 
2164 	rcu_read_lock();
2165  again:
2166 	pol = rcu_dereference(sk->sk_policy[dir]);
2167 	if (pol != NULL) {
2168 		bool match;
2169 		int err = 0;
2170 
2171 		if (pol->family != family) {
2172 			pol = NULL;
2173 			goto out;
2174 		}
2175 
2176 		match = xfrm_selector_match(&pol->selector, fl, family);
2177 		if (match) {
2178 			if ((sk->sk_mark & pol->mark.m) != pol->mark.v ||
2179 			    pol->if_id != if_id) {
2180 				pol = NULL;
2181 				goto out;
2182 			}
2183 			err = security_xfrm_policy_lookup(pol->security,
2184 						      fl->flowi_secid);
2185 			if (!err) {
2186 				if (!xfrm_pol_hold_rcu(pol))
2187 					goto again;
2188 			} else if (err == -ESRCH) {
2189 				pol = NULL;
2190 			} else {
2191 				pol = ERR_PTR(err);
2192 			}
2193 		} else
2194 			pol = NULL;
2195 	}
2196 out:
2197 	rcu_read_unlock();
2198 	return pol;
2199 }
2200 
__xfrm_policy_link(struct xfrm_policy * pol,int dir)2201 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
2202 {
2203 	struct net *net = xp_net(pol);
2204 
2205 	list_add(&pol->walk.all, &net->xfrm.policy_all);
2206 	net->xfrm.policy_count[dir]++;
2207 	xfrm_pol_hold(pol);
2208 }
2209 
__xfrm_policy_unlink(struct xfrm_policy * pol,int dir)2210 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
2211 						int dir)
2212 {
2213 	struct net *net = xp_net(pol);
2214 
2215 	if (list_empty(&pol->walk.all))
2216 		return NULL;
2217 
2218 	/* Socket policies are not hashed. */
2219 	if (!hlist_unhashed(&pol->bydst)) {
2220 		hlist_del_rcu(&pol->bydst);
2221 		hlist_del_init(&pol->bydst_inexact_list);
2222 		hlist_del(&pol->byidx);
2223 	}
2224 
2225 	list_del_init(&pol->walk.all);
2226 	net->xfrm.policy_count[dir]--;
2227 
2228 	return pol;
2229 }
2230 
xfrm_sk_policy_link(struct xfrm_policy * pol,int dir)2231 static void xfrm_sk_policy_link(struct xfrm_policy *pol, int dir)
2232 {
2233 	__xfrm_policy_link(pol, XFRM_POLICY_MAX + dir);
2234 }
2235 
xfrm_sk_policy_unlink(struct xfrm_policy * pol,int dir)2236 static void xfrm_sk_policy_unlink(struct xfrm_policy *pol, int dir)
2237 {
2238 	__xfrm_policy_unlink(pol, XFRM_POLICY_MAX + dir);
2239 }
2240 
xfrm_policy_delete(struct xfrm_policy * pol,int dir)2241 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
2242 {
2243 	struct net *net = xp_net(pol);
2244 
2245 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2246 	pol = __xfrm_policy_unlink(pol, dir);
2247 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2248 	if (pol) {
2249 		xfrm_policy_kill(pol);
2250 		return 0;
2251 	}
2252 	return -ENOENT;
2253 }
2254 EXPORT_SYMBOL(xfrm_policy_delete);
2255 
xfrm_sk_policy_insert(struct sock * sk,int dir,struct xfrm_policy * pol)2256 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
2257 {
2258 	struct net *net = sock_net(sk);
2259 	struct xfrm_policy *old_pol;
2260 
2261 #ifdef CONFIG_XFRM_SUB_POLICY
2262 	if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
2263 		return -EINVAL;
2264 #endif
2265 
2266 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2267 	old_pol = rcu_dereference_protected(sk->sk_policy[dir],
2268 				lockdep_is_held(&net->xfrm.xfrm_policy_lock));
2269 	if (pol) {
2270 		pol->curlft.add_time = ktime_get_real_seconds();
2271 		pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir, 0);
2272 		xfrm_sk_policy_link(pol, dir);
2273 	}
2274 	rcu_assign_pointer(sk->sk_policy[dir], pol);
2275 	if (old_pol) {
2276 		if (pol)
2277 			xfrm_policy_requeue(old_pol, pol);
2278 
2279 		/* Unlinking succeeds always. This is the only function
2280 		 * allowed to delete or replace socket policy.
2281 		 */
2282 		xfrm_sk_policy_unlink(old_pol, dir);
2283 	}
2284 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2285 
2286 	if (old_pol) {
2287 		xfrm_policy_kill(old_pol);
2288 	}
2289 	return 0;
2290 }
2291 
clone_policy(const struct xfrm_policy * old,int dir)2292 static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
2293 {
2294 	struct xfrm_policy *newp = xfrm_policy_alloc(xp_net(old), GFP_ATOMIC);
2295 	struct net *net = xp_net(old);
2296 
2297 	if (newp) {
2298 		newp->selector = old->selector;
2299 		if (security_xfrm_policy_clone(old->security,
2300 					       &newp->security)) {
2301 			kfree(newp);
2302 			return NULL;  /* ENOMEM */
2303 		}
2304 		newp->lft = old->lft;
2305 		newp->curlft = old->curlft;
2306 		newp->mark = old->mark;
2307 		newp->if_id = old->if_id;
2308 		newp->action = old->action;
2309 		newp->flags = old->flags;
2310 		newp->xfrm_nr = old->xfrm_nr;
2311 		newp->index = old->index;
2312 		newp->type = old->type;
2313 		newp->family = old->family;
2314 		memcpy(newp->xfrm_vec, old->xfrm_vec,
2315 		       newp->xfrm_nr*sizeof(struct xfrm_tmpl));
2316 		spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2317 		xfrm_sk_policy_link(newp, dir);
2318 		spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2319 		xfrm_pol_put(newp);
2320 	}
2321 	return newp;
2322 }
2323 
__xfrm_sk_clone_policy(struct sock * sk,const struct sock * osk)2324 int __xfrm_sk_clone_policy(struct sock *sk, const struct sock *osk)
2325 {
2326 	const struct xfrm_policy *p;
2327 	struct xfrm_policy *np;
2328 	int i, ret = 0;
2329 
2330 	rcu_read_lock();
2331 	for (i = 0; i < 2; i++) {
2332 		p = rcu_dereference(osk->sk_policy[i]);
2333 		if (p) {
2334 			np = clone_policy(p, i);
2335 			if (unlikely(!np)) {
2336 				ret = -ENOMEM;
2337 				break;
2338 			}
2339 			rcu_assign_pointer(sk->sk_policy[i], np);
2340 		}
2341 	}
2342 	rcu_read_unlock();
2343 	return ret;
2344 }
2345 
2346 static int
xfrm_get_saddr(struct net * net,int oif,xfrm_address_t * local,xfrm_address_t * remote,unsigned short family,u32 mark)2347 xfrm_get_saddr(struct net *net, int oif, xfrm_address_t *local,
2348 	       xfrm_address_t *remote, unsigned short family, u32 mark)
2349 {
2350 	int err;
2351 	const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2352 
2353 	if (unlikely(afinfo == NULL))
2354 		return -EINVAL;
2355 	err = afinfo->get_saddr(net, oif, local, remote, mark);
2356 	rcu_read_unlock();
2357 	return err;
2358 }
2359 
2360 /* Resolve list of templates for the flow, given policy. */
2361 
2362 static int
xfrm_tmpl_resolve_one(struct xfrm_policy * policy,const struct flowi * fl,struct xfrm_state ** xfrm,unsigned short family)2363 xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
2364 		      struct xfrm_state **xfrm, unsigned short family)
2365 {
2366 	struct net *net = xp_net(policy);
2367 	int nx;
2368 	int i, error;
2369 	xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
2370 	xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
2371 	xfrm_address_t tmp;
2372 
2373 	for (nx = 0, i = 0; i < policy->xfrm_nr; i++) {
2374 		struct xfrm_state *x;
2375 		xfrm_address_t *remote = daddr;
2376 		xfrm_address_t *local  = saddr;
2377 		struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
2378 
2379 		if (tmpl->mode == XFRM_MODE_TUNNEL ||
2380 		    tmpl->mode == XFRM_MODE_BEET) {
2381 			remote = &tmpl->id.daddr;
2382 			local = &tmpl->saddr;
2383 			if (xfrm_addr_any(local, tmpl->encap_family)) {
2384 				error = xfrm_get_saddr(net, fl->flowi_oif,
2385 						       &tmp, remote,
2386 						       tmpl->encap_family, 0);
2387 				if (error)
2388 					goto fail;
2389 				local = &tmp;
2390 			}
2391 		}
2392 
2393 		x = xfrm_state_find(remote, local, fl, tmpl, policy, &error,
2394 				    family, policy->if_id);
2395 
2396 		if (x && x->km.state == XFRM_STATE_VALID) {
2397 			xfrm[nx++] = x;
2398 			daddr = remote;
2399 			saddr = local;
2400 			continue;
2401 		}
2402 		if (x) {
2403 			error = (x->km.state == XFRM_STATE_ERROR ?
2404 				 -EINVAL : -EAGAIN);
2405 			xfrm_state_put(x);
2406 		} else if (error == -ESRCH) {
2407 			error = -EAGAIN;
2408 		}
2409 
2410 		if (!tmpl->optional)
2411 			goto fail;
2412 	}
2413 	return nx;
2414 
2415 fail:
2416 	for (nx--; nx >= 0; nx--)
2417 		xfrm_state_put(xfrm[nx]);
2418 	return error;
2419 }
2420 
2421 static int
xfrm_tmpl_resolve(struct xfrm_policy ** pols,int npols,const struct flowi * fl,struct xfrm_state ** xfrm,unsigned short family)2422 xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, const struct flowi *fl,
2423 		  struct xfrm_state **xfrm, unsigned short family)
2424 {
2425 	struct xfrm_state *tp[XFRM_MAX_DEPTH];
2426 	struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
2427 	int cnx = 0;
2428 	int error;
2429 	int ret;
2430 	int i;
2431 
2432 	for (i = 0; i < npols; i++) {
2433 		if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
2434 			error = -ENOBUFS;
2435 			goto fail;
2436 		}
2437 
2438 		ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
2439 		if (ret < 0) {
2440 			error = ret;
2441 			goto fail;
2442 		} else
2443 			cnx += ret;
2444 	}
2445 
2446 	/* found states are sorted for outbound processing */
2447 	if (npols > 1)
2448 		xfrm_state_sort(xfrm, tpp, cnx, family);
2449 
2450 	return cnx;
2451 
2452  fail:
2453 	for (cnx--; cnx >= 0; cnx--)
2454 		xfrm_state_put(tpp[cnx]);
2455 	return error;
2456 
2457 }
2458 
xfrm_get_tos(const struct flowi * fl,int family)2459 static int xfrm_get_tos(const struct flowi *fl, int family)
2460 {
2461 	if (family == AF_INET)
2462 		return IPTOS_RT_MASK & fl->u.ip4.flowi4_tos;
2463 
2464 	return 0;
2465 }
2466 
xfrm_alloc_dst(struct net * net,int family)2467 static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
2468 {
2469 	const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2470 	struct dst_ops *dst_ops;
2471 	struct xfrm_dst *xdst;
2472 
2473 	if (!afinfo)
2474 		return ERR_PTR(-EINVAL);
2475 
2476 	switch (family) {
2477 	case AF_INET:
2478 		dst_ops = &net->xfrm.xfrm4_dst_ops;
2479 		break;
2480 #if IS_ENABLED(CONFIG_IPV6)
2481 	case AF_INET6:
2482 		dst_ops = &net->xfrm.xfrm6_dst_ops;
2483 		break;
2484 #endif
2485 	default:
2486 		BUG();
2487 	}
2488 	xdst = dst_alloc(dst_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2489 
2490 	if (likely(xdst)) {
2491 		memset_after(xdst, 0, u.dst);
2492 	} else
2493 		xdst = ERR_PTR(-ENOBUFS);
2494 
2495 	rcu_read_unlock();
2496 
2497 	return xdst;
2498 }
2499 
xfrm_init_path(struct xfrm_dst * path,struct dst_entry * dst,int nfheader_len)2500 static void xfrm_init_path(struct xfrm_dst *path, struct dst_entry *dst,
2501 			   int nfheader_len)
2502 {
2503 	if (dst->ops->family == AF_INET6) {
2504 		struct rt6_info *rt = (struct rt6_info *)dst;
2505 		path->path_cookie = rt6_get_cookie(rt);
2506 		path->u.rt6.rt6i_nfheader_len = nfheader_len;
2507 	}
2508 }
2509 
xfrm_fill_dst(struct xfrm_dst * xdst,struct net_device * dev,const struct flowi * fl)2510 static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
2511 				const struct flowi *fl)
2512 {
2513 	const struct xfrm_policy_afinfo *afinfo =
2514 		xfrm_policy_get_afinfo(xdst->u.dst.ops->family);
2515 	int err;
2516 
2517 	if (!afinfo)
2518 		return -EINVAL;
2519 
2520 	err = afinfo->fill_dst(xdst, dev, fl);
2521 
2522 	rcu_read_unlock();
2523 
2524 	return err;
2525 }
2526 
2527 
2528 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
2529  * all the metrics... Shortly, bundle a bundle.
2530  */
2531 
xfrm_bundle_create(struct xfrm_policy * policy,struct xfrm_state ** xfrm,struct xfrm_dst ** bundle,int nx,const struct flowi * fl,struct dst_entry * dst)2532 static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
2533 					    struct xfrm_state **xfrm,
2534 					    struct xfrm_dst **bundle,
2535 					    int nx,
2536 					    const struct flowi *fl,
2537 					    struct dst_entry *dst)
2538 {
2539 	const struct xfrm_state_afinfo *afinfo;
2540 	const struct xfrm_mode *inner_mode;
2541 	struct net *net = xp_net(policy);
2542 	unsigned long now = jiffies;
2543 	struct net_device *dev;
2544 	struct xfrm_dst *xdst_prev = NULL;
2545 	struct xfrm_dst *xdst0 = NULL;
2546 	int i = 0;
2547 	int err;
2548 	int header_len = 0;
2549 	int nfheader_len = 0;
2550 	int trailer_len = 0;
2551 	int tos;
2552 	int family = policy->selector.family;
2553 	xfrm_address_t saddr, daddr;
2554 
2555 	xfrm_flowi_addr_get(fl, &saddr, &daddr, family);
2556 
2557 	tos = xfrm_get_tos(fl, family);
2558 
2559 	dst_hold(dst);
2560 
2561 	for (; i < nx; i++) {
2562 		struct xfrm_dst *xdst = xfrm_alloc_dst(net, family);
2563 		struct dst_entry *dst1 = &xdst->u.dst;
2564 
2565 		err = PTR_ERR(xdst);
2566 		if (IS_ERR(xdst)) {
2567 			dst_release(dst);
2568 			goto put_states;
2569 		}
2570 
2571 		bundle[i] = xdst;
2572 		if (!xdst_prev)
2573 			xdst0 = xdst;
2574 		else
2575 			/* Ref count is taken during xfrm_alloc_dst()
2576 			 * No need to do dst_clone() on dst1
2577 			 */
2578 			xfrm_dst_set_child(xdst_prev, &xdst->u.dst);
2579 
2580 		if (xfrm[i]->sel.family == AF_UNSPEC) {
2581 			inner_mode = xfrm_ip2inner_mode(xfrm[i],
2582 							xfrm_af2proto(family));
2583 			if (!inner_mode) {
2584 				err = -EAFNOSUPPORT;
2585 				dst_release(dst);
2586 				goto put_states;
2587 			}
2588 		} else
2589 			inner_mode = &xfrm[i]->inner_mode;
2590 
2591 		xdst->route = dst;
2592 		dst_copy_metrics(dst1, dst);
2593 
2594 		if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
2595 			__u32 mark = 0;
2596 			int oif;
2597 
2598 			if (xfrm[i]->props.smark.v || xfrm[i]->props.smark.m)
2599 				mark = xfrm_smark_get(fl->flowi_mark, xfrm[i]);
2600 
2601 			family = xfrm[i]->props.family;
2602 			oif = fl->flowi_oif ? : fl->flowi_l3mdev;
2603 			dst = xfrm_dst_lookup(xfrm[i], tos, oif,
2604 					      &saddr, &daddr, family, mark);
2605 			err = PTR_ERR(dst);
2606 			if (IS_ERR(dst))
2607 				goto put_states;
2608 		} else
2609 			dst_hold(dst);
2610 
2611 		dst1->xfrm = xfrm[i];
2612 		xdst->xfrm_genid = xfrm[i]->genid;
2613 
2614 		dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
2615 		dst1->lastuse = now;
2616 
2617 		dst1->input = dst_discard;
2618 
2619 		rcu_read_lock();
2620 		afinfo = xfrm_state_afinfo_get_rcu(inner_mode->family);
2621 		if (likely(afinfo))
2622 			dst1->output = afinfo->output;
2623 		else
2624 			dst1->output = dst_discard_out;
2625 		rcu_read_unlock();
2626 
2627 		xdst_prev = xdst;
2628 
2629 		header_len += xfrm[i]->props.header_len;
2630 		if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
2631 			nfheader_len += xfrm[i]->props.header_len;
2632 		trailer_len += xfrm[i]->props.trailer_len;
2633 	}
2634 
2635 	xfrm_dst_set_child(xdst_prev, dst);
2636 	xdst0->path = dst;
2637 
2638 	err = -ENODEV;
2639 	dev = dst->dev;
2640 	if (!dev)
2641 		goto free_dst;
2642 
2643 	xfrm_init_path(xdst0, dst, nfheader_len);
2644 	xfrm_init_pmtu(bundle, nx);
2645 
2646 	for (xdst_prev = xdst0; xdst_prev != (struct xfrm_dst *)dst;
2647 	     xdst_prev = (struct xfrm_dst *) xfrm_dst_child(&xdst_prev->u.dst)) {
2648 		err = xfrm_fill_dst(xdst_prev, dev, fl);
2649 		if (err)
2650 			goto free_dst;
2651 
2652 		xdst_prev->u.dst.header_len = header_len;
2653 		xdst_prev->u.dst.trailer_len = trailer_len;
2654 		header_len -= xdst_prev->u.dst.xfrm->props.header_len;
2655 		trailer_len -= xdst_prev->u.dst.xfrm->props.trailer_len;
2656 	}
2657 
2658 	return &xdst0->u.dst;
2659 
2660 put_states:
2661 	for (; i < nx; i++)
2662 		xfrm_state_put(xfrm[i]);
2663 free_dst:
2664 	if (xdst0)
2665 		dst_release_immediate(&xdst0->u.dst);
2666 
2667 	return ERR_PTR(err);
2668 }
2669 
xfrm_expand_policies(const struct flowi * fl,u16 family,struct xfrm_policy ** pols,int * num_pols,int * num_xfrms)2670 static int xfrm_expand_policies(const struct flowi *fl, u16 family,
2671 				struct xfrm_policy **pols,
2672 				int *num_pols, int *num_xfrms)
2673 {
2674 	int i;
2675 
2676 	if (*num_pols == 0 || !pols[0]) {
2677 		*num_pols = 0;
2678 		*num_xfrms = 0;
2679 		return 0;
2680 	}
2681 	if (IS_ERR(pols[0])) {
2682 		*num_pols = 0;
2683 		return PTR_ERR(pols[0]);
2684 	}
2685 
2686 	*num_xfrms = pols[0]->xfrm_nr;
2687 
2688 #ifdef CONFIG_XFRM_SUB_POLICY
2689 	if (pols[0]->action == XFRM_POLICY_ALLOW &&
2690 	    pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
2691 		pols[1] = xfrm_policy_lookup_bytype(xp_net(pols[0]),
2692 						    XFRM_POLICY_TYPE_MAIN,
2693 						    fl, family,
2694 						    XFRM_POLICY_OUT,
2695 						    pols[0]->if_id);
2696 		if (pols[1]) {
2697 			if (IS_ERR(pols[1])) {
2698 				xfrm_pols_put(pols, *num_pols);
2699 				*num_pols = 0;
2700 				return PTR_ERR(pols[1]);
2701 			}
2702 			(*num_pols)++;
2703 			(*num_xfrms) += pols[1]->xfrm_nr;
2704 		}
2705 	}
2706 #endif
2707 	for (i = 0; i < *num_pols; i++) {
2708 		if (pols[i]->action != XFRM_POLICY_ALLOW) {
2709 			*num_xfrms = -1;
2710 			break;
2711 		}
2712 	}
2713 
2714 	return 0;
2715 
2716 }
2717 
2718 static struct xfrm_dst *
xfrm_resolve_and_create_bundle(struct xfrm_policy ** pols,int num_pols,const struct flowi * fl,u16 family,struct dst_entry * dst_orig)2719 xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
2720 			       const struct flowi *fl, u16 family,
2721 			       struct dst_entry *dst_orig)
2722 {
2723 	struct net *net = xp_net(pols[0]);
2724 	struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
2725 	struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
2726 	struct xfrm_dst *xdst;
2727 	struct dst_entry *dst;
2728 	int err;
2729 
2730 	/* Try to instantiate a bundle */
2731 	err = xfrm_tmpl_resolve(pols, num_pols, fl, xfrm, family);
2732 	if (err <= 0) {
2733 		if (err == 0)
2734 			return NULL;
2735 
2736 		if (err != -EAGAIN)
2737 			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
2738 		return ERR_PTR(err);
2739 	}
2740 
2741 	dst = xfrm_bundle_create(pols[0], xfrm, bundle, err, fl, dst_orig);
2742 	if (IS_ERR(dst)) {
2743 		XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR);
2744 		return ERR_CAST(dst);
2745 	}
2746 
2747 	xdst = (struct xfrm_dst *)dst;
2748 	xdst->num_xfrms = err;
2749 	xdst->num_pols = num_pols;
2750 	memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
2751 	xdst->policy_genid = atomic_read(&pols[0]->genid);
2752 
2753 	return xdst;
2754 }
2755 
xfrm_policy_queue_process(struct timer_list * t)2756 static void xfrm_policy_queue_process(struct timer_list *t)
2757 {
2758 	struct sk_buff *skb;
2759 	struct sock *sk;
2760 	struct dst_entry *dst;
2761 	struct xfrm_policy *pol = from_timer(pol, t, polq.hold_timer);
2762 	struct net *net = xp_net(pol);
2763 	struct xfrm_policy_queue *pq = &pol->polq;
2764 	struct flowi fl;
2765 	struct sk_buff_head list;
2766 	__u32 skb_mark;
2767 
2768 	spin_lock(&pq->hold_queue.lock);
2769 	skb = skb_peek(&pq->hold_queue);
2770 	if (!skb) {
2771 		spin_unlock(&pq->hold_queue.lock);
2772 		goto out;
2773 	}
2774 	dst = skb_dst(skb);
2775 	sk = skb->sk;
2776 
2777 	/* Fixup the mark to support VTI. */
2778 	skb_mark = skb->mark;
2779 	skb->mark = pol->mark.v;
2780 	xfrm_decode_session(skb, &fl, dst->ops->family);
2781 	skb->mark = skb_mark;
2782 	spin_unlock(&pq->hold_queue.lock);
2783 
2784 	dst_hold(xfrm_dst_path(dst));
2785 	dst = xfrm_lookup(net, xfrm_dst_path(dst), &fl, sk, XFRM_LOOKUP_QUEUE);
2786 	if (IS_ERR(dst))
2787 		goto purge_queue;
2788 
2789 	if (dst->flags & DST_XFRM_QUEUE) {
2790 		dst_release(dst);
2791 
2792 		if (pq->timeout >= XFRM_QUEUE_TMO_MAX)
2793 			goto purge_queue;
2794 
2795 		pq->timeout = pq->timeout << 1;
2796 		if (!mod_timer(&pq->hold_timer, jiffies + pq->timeout))
2797 			xfrm_pol_hold(pol);
2798 		goto out;
2799 	}
2800 
2801 	dst_release(dst);
2802 
2803 	__skb_queue_head_init(&list);
2804 
2805 	spin_lock(&pq->hold_queue.lock);
2806 	pq->timeout = 0;
2807 	skb_queue_splice_init(&pq->hold_queue, &list);
2808 	spin_unlock(&pq->hold_queue.lock);
2809 
2810 	while (!skb_queue_empty(&list)) {
2811 		skb = __skb_dequeue(&list);
2812 
2813 		/* Fixup the mark to support VTI. */
2814 		skb_mark = skb->mark;
2815 		skb->mark = pol->mark.v;
2816 		xfrm_decode_session(skb, &fl, skb_dst(skb)->ops->family);
2817 		skb->mark = skb_mark;
2818 
2819 		dst_hold(xfrm_dst_path(skb_dst(skb)));
2820 		dst = xfrm_lookup(net, xfrm_dst_path(skb_dst(skb)), &fl, skb->sk, 0);
2821 		if (IS_ERR(dst)) {
2822 			kfree_skb(skb);
2823 			continue;
2824 		}
2825 
2826 		nf_reset_ct(skb);
2827 		skb_dst_drop(skb);
2828 		skb_dst_set(skb, dst);
2829 
2830 		dst_output(net, skb->sk, skb);
2831 	}
2832 
2833 out:
2834 	xfrm_pol_put(pol);
2835 	return;
2836 
2837 purge_queue:
2838 	pq->timeout = 0;
2839 	skb_queue_purge(&pq->hold_queue);
2840 	xfrm_pol_put(pol);
2841 }
2842 
xdst_queue_output(struct net * net,struct sock * sk,struct sk_buff * skb)2843 static int xdst_queue_output(struct net *net, struct sock *sk, struct sk_buff *skb)
2844 {
2845 	unsigned long sched_next;
2846 	struct dst_entry *dst = skb_dst(skb);
2847 	struct xfrm_dst *xdst = (struct xfrm_dst *) dst;
2848 	struct xfrm_policy *pol = xdst->pols[0];
2849 	struct xfrm_policy_queue *pq = &pol->polq;
2850 
2851 	if (unlikely(skb_fclone_busy(sk, skb))) {
2852 		kfree_skb(skb);
2853 		return 0;
2854 	}
2855 
2856 	if (pq->hold_queue.qlen > XFRM_MAX_QUEUE_LEN) {
2857 		kfree_skb(skb);
2858 		return -EAGAIN;
2859 	}
2860 
2861 	skb_dst_force(skb);
2862 
2863 	spin_lock_bh(&pq->hold_queue.lock);
2864 
2865 	if (!pq->timeout)
2866 		pq->timeout = XFRM_QUEUE_TMO_MIN;
2867 
2868 	sched_next = jiffies + pq->timeout;
2869 
2870 	if (del_timer(&pq->hold_timer)) {
2871 		if (time_before(pq->hold_timer.expires, sched_next))
2872 			sched_next = pq->hold_timer.expires;
2873 		xfrm_pol_put(pol);
2874 	}
2875 
2876 	__skb_queue_tail(&pq->hold_queue, skb);
2877 	if (!mod_timer(&pq->hold_timer, sched_next))
2878 		xfrm_pol_hold(pol);
2879 
2880 	spin_unlock_bh(&pq->hold_queue.lock);
2881 
2882 	return 0;
2883 }
2884 
xfrm_create_dummy_bundle(struct net * net,struct xfrm_flo * xflo,const struct flowi * fl,int num_xfrms,u16 family)2885 static struct xfrm_dst *xfrm_create_dummy_bundle(struct net *net,
2886 						 struct xfrm_flo *xflo,
2887 						 const struct flowi *fl,
2888 						 int num_xfrms,
2889 						 u16 family)
2890 {
2891 	int err;
2892 	struct net_device *dev;
2893 	struct dst_entry *dst;
2894 	struct dst_entry *dst1;
2895 	struct xfrm_dst *xdst;
2896 
2897 	xdst = xfrm_alloc_dst(net, family);
2898 	if (IS_ERR(xdst))
2899 		return xdst;
2900 
2901 	if (!(xflo->flags & XFRM_LOOKUP_QUEUE) ||
2902 	    net->xfrm.sysctl_larval_drop ||
2903 	    num_xfrms <= 0)
2904 		return xdst;
2905 
2906 	dst = xflo->dst_orig;
2907 	dst1 = &xdst->u.dst;
2908 	dst_hold(dst);
2909 	xdst->route = dst;
2910 
2911 	dst_copy_metrics(dst1, dst);
2912 
2913 	dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
2914 	dst1->flags |= DST_XFRM_QUEUE;
2915 	dst1->lastuse = jiffies;
2916 
2917 	dst1->input = dst_discard;
2918 	dst1->output = xdst_queue_output;
2919 
2920 	dst_hold(dst);
2921 	xfrm_dst_set_child(xdst, dst);
2922 	xdst->path = dst;
2923 
2924 	xfrm_init_path((struct xfrm_dst *)dst1, dst, 0);
2925 
2926 	err = -ENODEV;
2927 	dev = dst->dev;
2928 	if (!dev)
2929 		goto free_dst;
2930 
2931 	err = xfrm_fill_dst(xdst, dev, fl);
2932 	if (err)
2933 		goto free_dst;
2934 
2935 out:
2936 	return xdst;
2937 
2938 free_dst:
2939 	dst_release(dst1);
2940 	xdst = ERR_PTR(err);
2941 	goto out;
2942 }
2943 
xfrm_bundle_lookup(struct net * net,const struct flowi * fl,u16 family,u8 dir,struct xfrm_flo * xflo,u32 if_id)2944 static struct xfrm_dst *xfrm_bundle_lookup(struct net *net,
2945 					   const struct flowi *fl,
2946 					   u16 family, u8 dir,
2947 					   struct xfrm_flo *xflo, u32 if_id)
2948 {
2949 	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2950 	int num_pols = 0, num_xfrms = 0, err;
2951 	struct xfrm_dst *xdst;
2952 
2953 	/* Resolve policies to use if we couldn't get them from
2954 	 * previous cache entry */
2955 	num_pols = 1;
2956 	pols[0] = xfrm_policy_lookup(net, fl, family, dir, if_id);
2957 	err = xfrm_expand_policies(fl, family, pols,
2958 					   &num_pols, &num_xfrms);
2959 	if (err < 0)
2960 		goto inc_error;
2961 	if (num_pols == 0)
2962 		return NULL;
2963 	if (num_xfrms <= 0)
2964 		goto make_dummy_bundle;
2965 
2966 	xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family,
2967 					      xflo->dst_orig);
2968 	if (IS_ERR(xdst)) {
2969 		err = PTR_ERR(xdst);
2970 		if (err == -EREMOTE) {
2971 			xfrm_pols_put(pols, num_pols);
2972 			return NULL;
2973 		}
2974 
2975 		if (err != -EAGAIN)
2976 			goto error;
2977 		goto make_dummy_bundle;
2978 	} else if (xdst == NULL) {
2979 		num_xfrms = 0;
2980 		goto make_dummy_bundle;
2981 	}
2982 
2983 	return xdst;
2984 
2985 make_dummy_bundle:
2986 	/* We found policies, but there's no bundles to instantiate:
2987 	 * either because the policy blocks, has no transformations or
2988 	 * we could not build template (no xfrm_states).*/
2989 	xdst = xfrm_create_dummy_bundle(net, xflo, fl, num_xfrms, family);
2990 	if (IS_ERR(xdst)) {
2991 		xfrm_pols_put(pols, num_pols);
2992 		return ERR_CAST(xdst);
2993 	}
2994 	xdst->num_pols = num_pols;
2995 	xdst->num_xfrms = num_xfrms;
2996 	memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
2997 
2998 	return xdst;
2999 
3000 inc_error:
3001 	XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
3002 error:
3003 	xfrm_pols_put(pols, num_pols);
3004 	return ERR_PTR(err);
3005 }
3006 
make_blackhole(struct net * net,u16 family,struct dst_entry * dst_orig)3007 static struct dst_entry *make_blackhole(struct net *net, u16 family,
3008 					struct dst_entry *dst_orig)
3009 {
3010 	const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
3011 	struct dst_entry *ret;
3012 
3013 	if (!afinfo) {
3014 		dst_release(dst_orig);
3015 		return ERR_PTR(-EINVAL);
3016 	} else {
3017 		ret = afinfo->blackhole_route(net, dst_orig);
3018 	}
3019 	rcu_read_unlock();
3020 
3021 	return ret;
3022 }
3023 
3024 /* Finds/creates a bundle for given flow and if_id
3025  *
3026  * At the moment we eat a raw IP route. Mostly to speed up lookups
3027  * on interfaces with disabled IPsec.
3028  *
3029  * xfrm_lookup uses an if_id of 0 by default, and is provided for
3030  * compatibility
3031  */
xfrm_lookup_with_ifid(struct net * net,struct dst_entry * dst_orig,const struct flowi * fl,const struct sock * sk,int flags,u32 if_id)3032 struct dst_entry *xfrm_lookup_with_ifid(struct net *net,
3033 					struct dst_entry *dst_orig,
3034 					const struct flowi *fl,
3035 					const struct sock *sk,
3036 					int flags, u32 if_id)
3037 {
3038 	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
3039 	struct xfrm_dst *xdst;
3040 	struct dst_entry *dst, *route;
3041 	u16 family = dst_orig->ops->family;
3042 	u8 dir = XFRM_POLICY_OUT;
3043 	int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
3044 
3045 	dst = NULL;
3046 	xdst = NULL;
3047 	route = NULL;
3048 
3049 	sk = sk_const_to_full_sk(sk);
3050 	if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
3051 		num_pols = 1;
3052 		pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, family,
3053 						if_id);
3054 		err = xfrm_expand_policies(fl, family, pols,
3055 					   &num_pols, &num_xfrms);
3056 		if (err < 0)
3057 			goto dropdst;
3058 
3059 		if (num_pols) {
3060 			if (num_xfrms <= 0) {
3061 				drop_pols = num_pols;
3062 				goto no_transform;
3063 			}
3064 
3065 			xdst = xfrm_resolve_and_create_bundle(
3066 					pols, num_pols, fl,
3067 					family, dst_orig);
3068 
3069 			if (IS_ERR(xdst)) {
3070 				xfrm_pols_put(pols, num_pols);
3071 				err = PTR_ERR(xdst);
3072 				if (err == -EREMOTE)
3073 					goto nopol;
3074 
3075 				goto dropdst;
3076 			} else if (xdst == NULL) {
3077 				num_xfrms = 0;
3078 				drop_pols = num_pols;
3079 				goto no_transform;
3080 			}
3081 
3082 			route = xdst->route;
3083 		}
3084 	}
3085 
3086 	if (xdst == NULL) {
3087 		struct xfrm_flo xflo;
3088 
3089 		xflo.dst_orig = dst_orig;
3090 		xflo.flags = flags;
3091 
3092 		/* To accelerate a bit...  */
3093 		if (!if_id && ((dst_orig->flags & DST_NOXFRM) ||
3094 			       !net->xfrm.policy_count[XFRM_POLICY_OUT]))
3095 			goto nopol;
3096 
3097 		xdst = xfrm_bundle_lookup(net, fl, family, dir, &xflo, if_id);
3098 		if (xdst == NULL)
3099 			goto nopol;
3100 		if (IS_ERR(xdst)) {
3101 			err = PTR_ERR(xdst);
3102 			goto dropdst;
3103 		}
3104 
3105 		num_pols = xdst->num_pols;
3106 		num_xfrms = xdst->num_xfrms;
3107 		memcpy(pols, xdst->pols, sizeof(struct xfrm_policy *) * num_pols);
3108 		route = xdst->route;
3109 	}
3110 
3111 	dst = &xdst->u.dst;
3112 	if (route == NULL && num_xfrms > 0) {
3113 		/* The only case when xfrm_bundle_lookup() returns a
3114 		 * bundle with null route, is when the template could
3115 		 * not be resolved. It means policies are there, but
3116 		 * bundle could not be created, since we don't yet
3117 		 * have the xfrm_state's. We need to wait for KM to
3118 		 * negotiate new SA's or bail out with error.*/
3119 		if (net->xfrm.sysctl_larval_drop) {
3120 			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
3121 			err = -EREMOTE;
3122 			goto error;
3123 		}
3124 
3125 		err = -EAGAIN;
3126 
3127 		XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
3128 		goto error;
3129 	}
3130 
3131 no_transform:
3132 	if (num_pols == 0)
3133 		goto nopol;
3134 
3135 	if ((flags & XFRM_LOOKUP_ICMP) &&
3136 	    !(pols[0]->flags & XFRM_POLICY_ICMP)) {
3137 		err = -ENOENT;
3138 		goto error;
3139 	}
3140 
3141 	for (i = 0; i < num_pols; i++)
3142 		pols[i]->curlft.use_time = ktime_get_real_seconds();
3143 
3144 	if (num_xfrms < 0) {
3145 		/* Prohibit the flow */
3146 		XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLBLOCK);
3147 		err = -EPERM;
3148 		goto error;
3149 	} else if (num_xfrms > 0) {
3150 		/* Flow transformed */
3151 		dst_release(dst_orig);
3152 	} else {
3153 		/* Flow passes untransformed */
3154 		dst_release(dst);
3155 		dst = dst_orig;
3156 	}
3157 ok:
3158 	xfrm_pols_put(pols, drop_pols);
3159 	if (dst && dst->xfrm &&
3160 	    dst->xfrm->props.mode == XFRM_MODE_TUNNEL)
3161 		dst->flags |= DST_XFRM_TUNNEL;
3162 	return dst;
3163 
3164 nopol:
3165 	if ((!dst_orig->dev || !(dst_orig->dev->flags & IFF_LOOPBACK)) &&
3166 	    net->xfrm.policy_default[dir] == XFRM_USERPOLICY_BLOCK) {
3167 		err = -EPERM;
3168 		goto error;
3169 	}
3170 	if (!(flags & XFRM_LOOKUP_ICMP)) {
3171 		dst = dst_orig;
3172 		goto ok;
3173 	}
3174 	err = -ENOENT;
3175 error:
3176 	dst_release(dst);
3177 dropdst:
3178 	if (!(flags & XFRM_LOOKUP_KEEP_DST_REF))
3179 		dst_release(dst_orig);
3180 	xfrm_pols_put(pols, drop_pols);
3181 	return ERR_PTR(err);
3182 }
3183 EXPORT_SYMBOL(xfrm_lookup_with_ifid);
3184 
3185 /* Main function: finds/creates a bundle for given flow.
3186  *
3187  * At the moment we eat a raw IP route. Mostly to speed up lookups
3188  * on interfaces with disabled IPsec.
3189  */
xfrm_lookup(struct net * net,struct dst_entry * dst_orig,const struct flowi * fl,const struct sock * sk,int flags)3190 struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
3191 			      const struct flowi *fl, const struct sock *sk,
3192 			      int flags)
3193 {
3194 	return xfrm_lookup_with_ifid(net, dst_orig, fl, sk, flags, 0);
3195 }
3196 EXPORT_SYMBOL(xfrm_lookup);
3197 
3198 /* Callers of xfrm_lookup_route() must ensure a call to dst_output().
3199  * Otherwise we may send out blackholed packets.
3200  */
xfrm_lookup_route(struct net * net,struct dst_entry * dst_orig,const struct flowi * fl,const struct sock * sk,int flags)3201 struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
3202 				    const struct flowi *fl,
3203 				    const struct sock *sk, int flags)
3204 {
3205 	struct dst_entry *dst = xfrm_lookup(net, dst_orig, fl, sk,
3206 					    flags | XFRM_LOOKUP_QUEUE |
3207 					    XFRM_LOOKUP_KEEP_DST_REF);
3208 
3209 	if (PTR_ERR(dst) == -EREMOTE)
3210 		return make_blackhole(net, dst_orig->ops->family, dst_orig);
3211 
3212 	if (IS_ERR(dst))
3213 		dst_release(dst_orig);
3214 
3215 	return dst;
3216 }
3217 EXPORT_SYMBOL(xfrm_lookup_route);
3218 
3219 static inline int
xfrm_secpath_reject(int idx,struct sk_buff * skb,const struct flowi * fl)3220 xfrm_secpath_reject(int idx, struct sk_buff *skb, const struct flowi *fl)
3221 {
3222 	struct sec_path *sp = skb_sec_path(skb);
3223 	struct xfrm_state *x;
3224 
3225 	if (!sp || idx < 0 || idx >= sp->len)
3226 		return 0;
3227 	x = sp->xvec[idx];
3228 	if (!x->type->reject)
3229 		return 0;
3230 	return x->type->reject(x, skb, fl);
3231 }
3232 
3233 /* When skb is transformed back to its "native" form, we have to
3234  * check policy restrictions. At the moment we make this in maximally
3235  * stupid way. Shame on me. :-) Of course, connected sockets must
3236  * have policy cached at them.
3237  */
3238 
3239 static inline int
xfrm_state_ok(const struct xfrm_tmpl * tmpl,const struct xfrm_state * x,unsigned short family)3240 xfrm_state_ok(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x,
3241 	      unsigned short family)
3242 {
3243 	if (xfrm_state_kern(x))
3244 		return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
3245 	return	x->id.proto == tmpl->id.proto &&
3246 		(x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
3247 		(x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
3248 		x->props.mode == tmpl->mode &&
3249 		(tmpl->allalgs || (tmpl->aalgos & (1<<x->props.aalgo)) ||
3250 		 !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
3251 		!(x->props.mode != XFRM_MODE_TRANSPORT &&
3252 		  xfrm_state_addr_cmp(tmpl, x, family));
3253 }
3254 
3255 /*
3256  * 0 or more than 0 is returned when validation is succeeded (either bypass
3257  * because of optional transport mode, or next index of the matched secpath
3258  * state with the template.
3259  * -1 is returned when no matching template is found.
3260  * Otherwise "-2 - errored_index" is returned.
3261  */
3262 static inline int
xfrm_policy_ok(const struct xfrm_tmpl * tmpl,const struct sec_path * sp,int start,unsigned short family)3263 xfrm_policy_ok(const struct xfrm_tmpl *tmpl, const struct sec_path *sp, int start,
3264 	       unsigned short family)
3265 {
3266 	int idx = start;
3267 
3268 	if (tmpl->optional) {
3269 		if (tmpl->mode == XFRM_MODE_TRANSPORT)
3270 			return start;
3271 	} else
3272 		start = -1;
3273 	for (; idx < sp->len; idx++) {
3274 		if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
3275 			return ++idx;
3276 		if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
3277 			if (start == -1)
3278 				start = -2-idx;
3279 			break;
3280 		}
3281 	}
3282 	return start;
3283 }
3284 
3285 static void
decode_session4(struct sk_buff * skb,struct flowi * fl,bool reverse)3286 decode_session4(struct sk_buff *skb, struct flowi *fl, bool reverse)
3287 {
3288 	const struct iphdr *iph = ip_hdr(skb);
3289 	int ihl = iph->ihl;
3290 	u8 *xprth = skb_network_header(skb) + ihl * 4;
3291 	struct flowi4 *fl4 = &fl->u.ip4;
3292 	int oif = 0;
3293 
3294 	if (skb_dst(skb) && skb_dst(skb)->dev)
3295 		oif = skb_dst(skb)->dev->ifindex;
3296 
3297 	memset(fl4, 0, sizeof(struct flowi4));
3298 	fl4->flowi4_mark = skb->mark;
3299 	fl4->flowi4_oif = reverse ? skb->skb_iif : oif;
3300 
3301 	fl4->flowi4_proto = iph->protocol;
3302 	fl4->daddr = reverse ? iph->saddr : iph->daddr;
3303 	fl4->saddr = reverse ? iph->daddr : iph->saddr;
3304 	fl4->flowi4_tos = iph->tos & ~INET_ECN_MASK;
3305 
3306 	if (!ip_is_fragment(iph)) {
3307 		switch (iph->protocol) {
3308 		case IPPROTO_UDP:
3309 		case IPPROTO_UDPLITE:
3310 		case IPPROTO_TCP:
3311 		case IPPROTO_SCTP:
3312 		case IPPROTO_DCCP:
3313 			if (xprth + 4 < skb->data ||
3314 			    pskb_may_pull(skb, xprth + 4 - skb->data)) {
3315 				__be16 *ports;
3316 
3317 				xprth = skb_network_header(skb) + ihl * 4;
3318 				ports = (__be16 *)xprth;
3319 
3320 				fl4->fl4_sport = ports[!!reverse];
3321 				fl4->fl4_dport = ports[!reverse];
3322 			}
3323 			break;
3324 		case IPPROTO_ICMP:
3325 			if (xprth + 2 < skb->data ||
3326 			    pskb_may_pull(skb, xprth + 2 - skb->data)) {
3327 				u8 *icmp;
3328 
3329 				xprth = skb_network_header(skb) + ihl * 4;
3330 				icmp = xprth;
3331 
3332 				fl4->fl4_icmp_type = icmp[0];
3333 				fl4->fl4_icmp_code = icmp[1];
3334 			}
3335 			break;
3336 		case IPPROTO_GRE:
3337 			if (xprth + 12 < skb->data ||
3338 			    pskb_may_pull(skb, xprth + 12 - skb->data)) {
3339 				__be16 *greflags;
3340 				__be32 *gre_hdr;
3341 
3342 				xprth = skb_network_header(skb) + ihl * 4;
3343 				greflags = (__be16 *)xprth;
3344 				gre_hdr = (__be32 *)xprth;
3345 
3346 				if (greflags[0] & GRE_KEY) {
3347 					if (greflags[0] & GRE_CSUM)
3348 						gre_hdr++;
3349 					fl4->fl4_gre_key = gre_hdr[1];
3350 				}
3351 			}
3352 			break;
3353 		default:
3354 			break;
3355 		}
3356 	}
3357 }
3358 
3359 #if IS_ENABLED(CONFIG_IPV6)
3360 static void
decode_session6(struct sk_buff * skb,struct flowi * fl,bool reverse)3361 decode_session6(struct sk_buff *skb, struct flowi *fl, bool reverse)
3362 {
3363 	struct flowi6 *fl6 = &fl->u.ip6;
3364 	int onlyproto = 0;
3365 	const struct ipv6hdr *hdr = ipv6_hdr(skb);
3366 	u32 offset = sizeof(*hdr);
3367 	struct ipv6_opt_hdr *exthdr;
3368 	const unsigned char *nh = skb_network_header(skb);
3369 	u16 nhoff = IP6CB(skb)->nhoff;
3370 	int oif = 0;
3371 	u8 nexthdr;
3372 
3373 	if (!nhoff)
3374 		nhoff = offsetof(struct ipv6hdr, nexthdr);
3375 
3376 	nexthdr = nh[nhoff];
3377 
3378 	if (skb_dst(skb) && skb_dst(skb)->dev)
3379 		oif = skb_dst(skb)->dev->ifindex;
3380 
3381 	memset(fl6, 0, sizeof(struct flowi6));
3382 	fl6->flowi6_mark = skb->mark;
3383 	fl6->flowi6_oif = reverse ? skb->skb_iif : oif;
3384 
3385 	fl6->daddr = reverse ? hdr->saddr : hdr->daddr;
3386 	fl6->saddr = reverse ? hdr->daddr : hdr->saddr;
3387 
3388 	while (nh + offset + sizeof(*exthdr) < skb->data ||
3389 	       pskb_may_pull(skb, nh + offset + sizeof(*exthdr) - skb->data)) {
3390 		nh = skb_network_header(skb);
3391 		exthdr = (struct ipv6_opt_hdr *)(nh + offset);
3392 
3393 		switch (nexthdr) {
3394 		case NEXTHDR_FRAGMENT:
3395 			onlyproto = 1;
3396 			fallthrough;
3397 		case NEXTHDR_ROUTING:
3398 		case NEXTHDR_HOP:
3399 		case NEXTHDR_DEST:
3400 			offset += ipv6_optlen(exthdr);
3401 			nexthdr = exthdr->nexthdr;
3402 			break;
3403 		case IPPROTO_UDP:
3404 		case IPPROTO_UDPLITE:
3405 		case IPPROTO_TCP:
3406 		case IPPROTO_SCTP:
3407 		case IPPROTO_DCCP:
3408 			if (!onlyproto && (nh + offset + 4 < skb->data ||
3409 			     pskb_may_pull(skb, nh + offset + 4 - skb->data))) {
3410 				__be16 *ports;
3411 
3412 				nh = skb_network_header(skb);
3413 				ports = (__be16 *)(nh + offset);
3414 				fl6->fl6_sport = ports[!!reverse];
3415 				fl6->fl6_dport = ports[!reverse];
3416 			}
3417 			fl6->flowi6_proto = nexthdr;
3418 			return;
3419 		case IPPROTO_ICMPV6:
3420 			if (!onlyproto && (nh + offset + 2 < skb->data ||
3421 			    pskb_may_pull(skb, nh + offset + 2 - skb->data))) {
3422 				u8 *icmp;
3423 
3424 				nh = skb_network_header(skb);
3425 				icmp = (u8 *)(nh + offset);
3426 				fl6->fl6_icmp_type = icmp[0];
3427 				fl6->fl6_icmp_code = icmp[1];
3428 			}
3429 			fl6->flowi6_proto = nexthdr;
3430 			return;
3431 		case IPPROTO_GRE:
3432 			if (!onlyproto &&
3433 			    (nh + offset + 12 < skb->data ||
3434 			     pskb_may_pull(skb, nh + offset + 12 - skb->data))) {
3435 				struct gre_base_hdr *gre_hdr;
3436 				__be32 *gre_key;
3437 
3438 				nh = skb_network_header(skb);
3439 				gre_hdr = (struct gre_base_hdr *)(nh + offset);
3440 				gre_key = (__be32 *)(gre_hdr + 1);
3441 
3442 				if (gre_hdr->flags & GRE_KEY) {
3443 					if (gre_hdr->flags & GRE_CSUM)
3444 						gre_key++;
3445 					fl6->fl6_gre_key = *gre_key;
3446 				}
3447 			}
3448 			fl6->flowi6_proto = nexthdr;
3449 			return;
3450 
3451 #if IS_ENABLED(CONFIG_IPV6_MIP6)
3452 		case IPPROTO_MH:
3453 			offset += ipv6_optlen(exthdr);
3454 			if (!onlyproto && (nh + offset + 3 < skb->data ||
3455 			    pskb_may_pull(skb, nh + offset + 3 - skb->data))) {
3456 				struct ip6_mh *mh;
3457 
3458 				nh = skb_network_header(skb);
3459 				mh = (struct ip6_mh *)(nh + offset);
3460 				fl6->fl6_mh_type = mh->ip6mh_type;
3461 			}
3462 			fl6->flowi6_proto = nexthdr;
3463 			return;
3464 #endif
3465 		default:
3466 			fl6->flowi6_proto = nexthdr;
3467 			return;
3468 		}
3469 	}
3470 }
3471 #endif
3472 
__xfrm_decode_session(struct sk_buff * skb,struct flowi * fl,unsigned int family,int reverse)3473 int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
3474 			  unsigned int family, int reverse)
3475 {
3476 	switch (family) {
3477 	case AF_INET:
3478 		decode_session4(skb, fl, reverse);
3479 		break;
3480 #if IS_ENABLED(CONFIG_IPV6)
3481 	case AF_INET6:
3482 		decode_session6(skb, fl, reverse);
3483 		break;
3484 #endif
3485 	default:
3486 		return -EAFNOSUPPORT;
3487 	}
3488 
3489 	return security_xfrm_decode_session(skb, &fl->flowi_secid);
3490 }
3491 EXPORT_SYMBOL(__xfrm_decode_session);
3492 
secpath_has_nontransport(const struct sec_path * sp,int k,int * idxp)3493 static inline int secpath_has_nontransport(const struct sec_path *sp, int k, int *idxp)
3494 {
3495 	for (; k < sp->len; k++) {
3496 		if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
3497 			*idxp = k;
3498 			return 1;
3499 		}
3500 	}
3501 
3502 	return 0;
3503 }
3504 
__xfrm_policy_check(struct sock * sk,int dir,struct sk_buff * skb,unsigned short family)3505 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
3506 			unsigned short family)
3507 {
3508 	struct net *net = dev_net(skb->dev);
3509 	struct xfrm_policy *pol;
3510 	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
3511 	int npols = 0;
3512 	int xfrm_nr;
3513 	int pi;
3514 	int reverse;
3515 	struct flowi fl;
3516 	int xerr_idx = -1;
3517 	const struct xfrm_if_cb *ifcb;
3518 	struct sec_path *sp;
3519 	struct xfrm_if *xi;
3520 	u32 if_id = 0;
3521 
3522 	rcu_read_lock();
3523 	ifcb = xfrm_if_get_cb();
3524 
3525 	if (ifcb) {
3526 		xi = ifcb->decode_session(skb, family);
3527 		if (xi) {
3528 			if_id = xi->p.if_id;
3529 			net = xi->net;
3530 		}
3531 	}
3532 	rcu_read_unlock();
3533 
3534 	reverse = dir & ~XFRM_POLICY_MASK;
3535 	dir &= XFRM_POLICY_MASK;
3536 
3537 	if (__xfrm_decode_session(skb, &fl, family, reverse) < 0) {
3538 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
3539 		return 0;
3540 	}
3541 
3542 	nf_nat_decode_session(skb, &fl, family);
3543 
3544 	/* First, check used SA against their selectors. */
3545 	sp = skb_sec_path(skb);
3546 	if (sp) {
3547 		int i;
3548 
3549 		for (i = sp->len - 1; i >= 0; i--) {
3550 			struct xfrm_state *x = sp->xvec[i];
3551 			if (!xfrm_selector_match(&x->sel, &fl, family)) {
3552 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
3553 				return 0;
3554 			}
3555 		}
3556 	}
3557 
3558 	pol = NULL;
3559 	sk = sk_to_full_sk(sk);
3560 	if (sk && sk->sk_policy[dir]) {
3561 		pol = xfrm_sk_policy_lookup(sk, dir, &fl, family, if_id);
3562 		if (IS_ERR(pol)) {
3563 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
3564 			return 0;
3565 		}
3566 	}
3567 
3568 	if (!pol)
3569 		pol = xfrm_policy_lookup(net, &fl, family, dir, if_id);
3570 
3571 	if (IS_ERR(pol)) {
3572 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
3573 		return 0;
3574 	}
3575 
3576 	if (!pol) {
3577 		if (net->xfrm.policy_default[dir] == XFRM_USERPOLICY_BLOCK) {
3578 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
3579 			return 0;
3580 		}
3581 
3582 		if (sp && secpath_has_nontransport(sp, 0, &xerr_idx)) {
3583 			xfrm_secpath_reject(xerr_idx, skb, &fl);
3584 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
3585 			return 0;
3586 		}
3587 		return 1;
3588 	}
3589 
3590 	pol->curlft.use_time = ktime_get_real_seconds();
3591 
3592 	pols[0] = pol;
3593 	npols++;
3594 #ifdef CONFIG_XFRM_SUB_POLICY
3595 	if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
3596 		pols[1] = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN,
3597 						    &fl, family,
3598 						    XFRM_POLICY_IN, if_id);
3599 		if (pols[1]) {
3600 			if (IS_ERR(pols[1])) {
3601 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
3602 				xfrm_pol_put(pols[0]);
3603 				return 0;
3604 			}
3605 			pols[1]->curlft.use_time = ktime_get_real_seconds();
3606 			npols++;
3607 		}
3608 	}
3609 #endif
3610 
3611 	if (pol->action == XFRM_POLICY_ALLOW) {
3612 		static struct sec_path dummy;
3613 		struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
3614 		struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
3615 		struct xfrm_tmpl **tpp = tp;
3616 		int ti = 0;
3617 		int i, k;
3618 
3619 		sp = skb_sec_path(skb);
3620 		if (!sp)
3621 			sp = &dummy;
3622 
3623 		for (pi = 0; pi < npols; pi++) {
3624 			if (pols[pi] != pol &&
3625 			    pols[pi]->action != XFRM_POLICY_ALLOW) {
3626 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
3627 				goto reject;
3628 			}
3629 			if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH) {
3630 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
3631 				goto reject_error;
3632 			}
3633 			for (i = 0; i < pols[pi]->xfrm_nr; i++)
3634 				tpp[ti++] = &pols[pi]->xfrm_vec[i];
3635 		}
3636 		xfrm_nr = ti;
3637 
3638 		if (net->xfrm.policy_default[dir] == XFRM_USERPOLICY_BLOCK &&
3639 		    !xfrm_nr) {
3640 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
3641 			goto reject;
3642 		}
3643 
3644 		if (npols > 1) {
3645 			xfrm_tmpl_sort(stp, tpp, xfrm_nr, family);
3646 			tpp = stp;
3647 		}
3648 
3649 		/* For each tunnel xfrm, find the first matching tmpl.
3650 		 * For each tmpl before that, find corresponding xfrm.
3651 		 * Order is _important_. Later we will implement
3652 		 * some barriers, but at the moment barriers
3653 		 * are implied between each two transformations.
3654 		 */
3655 		for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
3656 			k = xfrm_policy_ok(tpp[i], sp, k, family);
3657 			if (k < 0) {
3658 				if (k < -1)
3659 					/* "-2 - errored_index" returned */
3660 					xerr_idx = -(2+k);
3661 				XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
3662 				goto reject;
3663 			}
3664 		}
3665 
3666 		if (secpath_has_nontransport(sp, k, &xerr_idx)) {
3667 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
3668 			goto reject;
3669 		}
3670 
3671 		xfrm_pols_put(pols, npols);
3672 		return 1;
3673 	}
3674 	XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
3675 
3676 reject:
3677 	xfrm_secpath_reject(xerr_idx, skb, &fl);
3678 reject_error:
3679 	xfrm_pols_put(pols, npols);
3680 	return 0;
3681 }
3682 EXPORT_SYMBOL(__xfrm_policy_check);
3683 
__xfrm_route_forward(struct sk_buff * skb,unsigned short family)3684 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
3685 {
3686 	struct net *net = dev_net(skb->dev);
3687 	struct flowi fl;
3688 	struct dst_entry *dst;
3689 	int res = 1;
3690 
3691 	if (xfrm_decode_session(skb, &fl, family) < 0) {
3692 		XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
3693 		return 0;
3694 	}
3695 
3696 	skb_dst_force(skb);
3697 	if (!skb_dst(skb)) {
3698 		XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
3699 		return 0;
3700 	}
3701 
3702 	dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, XFRM_LOOKUP_QUEUE);
3703 	if (IS_ERR(dst)) {
3704 		res = 0;
3705 		dst = NULL;
3706 	}
3707 	skb_dst_set(skb, dst);
3708 	return res;
3709 }
3710 EXPORT_SYMBOL(__xfrm_route_forward);
3711 
3712 /* Optimize later using cookies and generation ids. */
3713 
xfrm_dst_check(struct dst_entry * dst,u32 cookie)3714 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
3715 {
3716 	/* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
3717 	 * to DST_OBSOLETE_FORCE_CHK to force all XFRM destinations to
3718 	 * get validated by dst_ops->check on every use.  We do this
3719 	 * because when a normal route referenced by an XFRM dst is
3720 	 * obsoleted we do not go looking around for all parent
3721 	 * referencing XFRM dsts so that we can invalidate them.  It
3722 	 * is just too much work.  Instead we make the checks here on
3723 	 * every use.  For example:
3724 	 *
3725 	 *	XFRM dst A --> IPv4 dst X
3726 	 *
3727 	 * X is the "xdst->route" of A (X is also the "dst->path" of A
3728 	 * in this example).  If X is marked obsolete, "A" will not
3729 	 * notice.  That's what we are validating here via the
3730 	 * stale_bundle() check.
3731 	 *
3732 	 * When a dst is removed from the fib tree, DST_OBSOLETE_DEAD will
3733 	 * be marked on it.
3734 	 * This will force stale_bundle() to fail on any xdst bundle with
3735 	 * this dst linked in it.
3736 	 */
3737 	if (dst->obsolete < 0 && !stale_bundle(dst))
3738 		return dst;
3739 
3740 	return NULL;
3741 }
3742 
stale_bundle(struct dst_entry * dst)3743 static int stale_bundle(struct dst_entry *dst)
3744 {
3745 	return !xfrm_bundle_ok((struct xfrm_dst *)dst);
3746 }
3747 
xfrm_dst_ifdown(struct dst_entry * dst,struct net_device * dev)3748 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
3749 {
3750 	while ((dst = xfrm_dst_child(dst)) && dst->xfrm && dst->dev == dev) {
3751 		dst->dev = blackhole_netdev;
3752 		dev_hold(dst->dev);
3753 		dev_put(dev);
3754 	}
3755 }
3756 EXPORT_SYMBOL(xfrm_dst_ifdown);
3757 
xfrm_link_failure(struct sk_buff * skb)3758 static void xfrm_link_failure(struct sk_buff *skb)
3759 {
3760 	/* Impossible. Such dst must be popped before reaches point of failure. */
3761 }
3762 
xfrm_negative_advice(struct dst_entry * dst)3763 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
3764 {
3765 	if (dst) {
3766 		if (dst->obsolete) {
3767 			dst_release(dst);
3768 			dst = NULL;
3769 		}
3770 	}
3771 	return dst;
3772 }
3773 
xfrm_init_pmtu(struct xfrm_dst ** bundle,int nr)3774 static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr)
3775 {
3776 	while (nr--) {
3777 		struct xfrm_dst *xdst = bundle[nr];
3778 		u32 pmtu, route_mtu_cached;
3779 		struct dst_entry *dst;
3780 
3781 		dst = &xdst->u.dst;
3782 		pmtu = dst_mtu(xfrm_dst_child(dst));
3783 		xdst->child_mtu_cached = pmtu;
3784 
3785 		pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
3786 
3787 		route_mtu_cached = dst_mtu(xdst->route);
3788 		xdst->route_mtu_cached = route_mtu_cached;
3789 
3790 		if (pmtu > route_mtu_cached)
3791 			pmtu = route_mtu_cached;
3792 
3793 		dst_metric_set(dst, RTAX_MTU, pmtu);
3794 	}
3795 }
3796 
3797 /* Check that the bundle accepts the flow and its components are
3798  * still valid.
3799  */
3800 
xfrm_bundle_ok(struct xfrm_dst * first)3801 static int xfrm_bundle_ok(struct xfrm_dst *first)
3802 {
3803 	struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
3804 	struct dst_entry *dst = &first->u.dst;
3805 	struct xfrm_dst *xdst;
3806 	int start_from, nr;
3807 	u32 mtu;
3808 
3809 	if (!dst_check(xfrm_dst_path(dst), ((struct xfrm_dst *)dst)->path_cookie) ||
3810 	    (dst->dev && !netif_running(dst->dev)))
3811 		return 0;
3812 
3813 	if (dst->flags & DST_XFRM_QUEUE)
3814 		return 1;
3815 
3816 	start_from = nr = 0;
3817 	do {
3818 		struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
3819 
3820 		if (dst->xfrm->km.state != XFRM_STATE_VALID)
3821 			return 0;
3822 		if (xdst->xfrm_genid != dst->xfrm->genid)
3823 			return 0;
3824 		if (xdst->num_pols > 0 &&
3825 		    xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
3826 			return 0;
3827 
3828 		bundle[nr++] = xdst;
3829 
3830 		mtu = dst_mtu(xfrm_dst_child(dst));
3831 		if (xdst->child_mtu_cached != mtu) {
3832 			start_from = nr;
3833 			xdst->child_mtu_cached = mtu;
3834 		}
3835 
3836 		if (!dst_check(xdst->route, xdst->route_cookie))
3837 			return 0;
3838 		mtu = dst_mtu(xdst->route);
3839 		if (xdst->route_mtu_cached != mtu) {
3840 			start_from = nr;
3841 			xdst->route_mtu_cached = mtu;
3842 		}
3843 
3844 		dst = xfrm_dst_child(dst);
3845 	} while (dst->xfrm);
3846 
3847 	if (likely(!start_from))
3848 		return 1;
3849 
3850 	xdst = bundle[start_from - 1];
3851 	mtu = xdst->child_mtu_cached;
3852 	while (start_from--) {
3853 		dst = &xdst->u.dst;
3854 
3855 		mtu = xfrm_state_mtu(dst->xfrm, mtu);
3856 		if (mtu > xdst->route_mtu_cached)
3857 			mtu = xdst->route_mtu_cached;
3858 		dst_metric_set(dst, RTAX_MTU, mtu);
3859 		if (!start_from)
3860 			break;
3861 
3862 		xdst = bundle[start_from - 1];
3863 		xdst->child_mtu_cached = mtu;
3864 	}
3865 
3866 	return 1;
3867 }
3868 
xfrm_default_advmss(const struct dst_entry * dst)3869 static unsigned int xfrm_default_advmss(const struct dst_entry *dst)
3870 {
3871 	return dst_metric_advmss(xfrm_dst_path(dst));
3872 }
3873 
xfrm_mtu(const struct dst_entry * dst)3874 static unsigned int xfrm_mtu(const struct dst_entry *dst)
3875 {
3876 	unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
3877 
3878 	return mtu ? : dst_mtu(xfrm_dst_path(dst));
3879 }
3880 
xfrm_get_dst_nexthop(const struct dst_entry * dst,const void * daddr)3881 static const void *xfrm_get_dst_nexthop(const struct dst_entry *dst,
3882 					const void *daddr)
3883 {
3884 	while (dst->xfrm) {
3885 		const struct xfrm_state *xfrm = dst->xfrm;
3886 
3887 		dst = xfrm_dst_child(dst);
3888 
3889 		if (xfrm->props.mode == XFRM_MODE_TRANSPORT)
3890 			continue;
3891 		if (xfrm->type->flags & XFRM_TYPE_REMOTE_COADDR)
3892 			daddr = xfrm->coaddr;
3893 		else if (!(xfrm->type->flags & XFRM_TYPE_LOCAL_COADDR))
3894 			daddr = &xfrm->id.daddr;
3895 	}
3896 	return daddr;
3897 }
3898 
xfrm_neigh_lookup(const struct dst_entry * dst,struct sk_buff * skb,const void * daddr)3899 static struct neighbour *xfrm_neigh_lookup(const struct dst_entry *dst,
3900 					   struct sk_buff *skb,
3901 					   const void *daddr)
3902 {
3903 	const struct dst_entry *path = xfrm_dst_path(dst);
3904 
3905 	if (!skb)
3906 		daddr = xfrm_get_dst_nexthop(dst, daddr);
3907 	return path->ops->neigh_lookup(path, skb, daddr);
3908 }
3909 
xfrm_confirm_neigh(const struct dst_entry * dst,const void * daddr)3910 static void xfrm_confirm_neigh(const struct dst_entry *dst, const void *daddr)
3911 {
3912 	const struct dst_entry *path = xfrm_dst_path(dst);
3913 
3914 	daddr = xfrm_get_dst_nexthop(dst, daddr);
3915 	path->ops->confirm_neigh(path, daddr);
3916 }
3917 
xfrm_policy_register_afinfo(const struct xfrm_policy_afinfo * afinfo,int family)3918 int xfrm_policy_register_afinfo(const struct xfrm_policy_afinfo *afinfo, int family)
3919 {
3920 	int err = 0;
3921 
3922 	if (WARN_ON(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
3923 		return -EAFNOSUPPORT;
3924 
3925 	spin_lock(&xfrm_policy_afinfo_lock);
3926 	if (unlikely(xfrm_policy_afinfo[family] != NULL))
3927 		err = -EEXIST;
3928 	else {
3929 		struct dst_ops *dst_ops = afinfo->dst_ops;
3930 		if (likely(dst_ops->kmem_cachep == NULL))
3931 			dst_ops->kmem_cachep = xfrm_dst_cache;
3932 		if (likely(dst_ops->check == NULL))
3933 			dst_ops->check = xfrm_dst_check;
3934 		if (likely(dst_ops->default_advmss == NULL))
3935 			dst_ops->default_advmss = xfrm_default_advmss;
3936 		if (likely(dst_ops->mtu == NULL))
3937 			dst_ops->mtu = xfrm_mtu;
3938 		if (likely(dst_ops->negative_advice == NULL))
3939 			dst_ops->negative_advice = xfrm_negative_advice;
3940 		if (likely(dst_ops->link_failure == NULL))
3941 			dst_ops->link_failure = xfrm_link_failure;
3942 		if (likely(dst_ops->neigh_lookup == NULL))
3943 			dst_ops->neigh_lookup = xfrm_neigh_lookup;
3944 		if (likely(!dst_ops->confirm_neigh))
3945 			dst_ops->confirm_neigh = xfrm_confirm_neigh;
3946 		rcu_assign_pointer(xfrm_policy_afinfo[family], afinfo);
3947 	}
3948 	spin_unlock(&xfrm_policy_afinfo_lock);
3949 
3950 	return err;
3951 }
3952 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
3953 
xfrm_policy_unregister_afinfo(const struct xfrm_policy_afinfo * afinfo)3954 void xfrm_policy_unregister_afinfo(const struct xfrm_policy_afinfo *afinfo)
3955 {
3956 	struct dst_ops *dst_ops = afinfo->dst_ops;
3957 	int i;
3958 
3959 	for (i = 0; i < ARRAY_SIZE(xfrm_policy_afinfo); i++) {
3960 		if (xfrm_policy_afinfo[i] != afinfo)
3961 			continue;
3962 		RCU_INIT_POINTER(xfrm_policy_afinfo[i], NULL);
3963 		break;
3964 	}
3965 
3966 	synchronize_rcu();
3967 
3968 	dst_ops->kmem_cachep = NULL;
3969 	dst_ops->check = NULL;
3970 	dst_ops->negative_advice = NULL;
3971 	dst_ops->link_failure = NULL;
3972 }
3973 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
3974 
xfrm_if_register_cb(const struct xfrm_if_cb * ifcb)3975 void xfrm_if_register_cb(const struct xfrm_if_cb *ifcb)
3976 {
3977 	spin_lock(&xfrm_if_cb_lock);
3978 	rcu_assign_pointer(xfrm_if_cb, ifcb);
3979 	spin_unlock(&xfrm_if_cb_lock);
3980 }
3981 EXPORT_SYMBOL(xfrm_if_register_cb);
3982 
xfrm_if_unregister_cb(void)3983 void xfrm_if_unregister_cb(void)
3984 {
3985 	RCU_INIT_POINTER(xfrm_if_cb, NULL);
3986 	synchronize_rcu();
3987 }
3988 EXPORT_SYMBOL(xfrm_if_unregister_cb);
3989 
3990 #ifdef CONFIG_XFRM_STATISTICS
xfrm_statistics_init(struct net * net)3991 static int __net_init xfrm_statistics_init(struct net *net)
3992 {
3993 	int rv;
3994 	net->mib.xfrm_statistics = alloc_percpu(struct linux_xfrm_mib);
3995 	if (!net->mib.xfrm_statistics)
3996 		return -ENOMEM;
3997 	rv = xfrm_proc_init(net);
3998 	if (rv < 0)
3999 		free_percpu(net->mib.xfrm_statistics);
4000 	return rv;
4001 }
4002 
xfrm_statistics_fini(struct net * net)4003 static void xfrm_statistics_fini(struct net *net)
4004 {
4005 	xfrm_proc_fini(net);
4006 	free_percpu(net->mib.xfrm_statistics);
4007 }
4008 #else
xfrm_statistics_init(struct net * net)4009 static int __net_init xfrm_statistics_init(struct net *net)
4010 {
4011 	return 0;
4012 }
4013 
xfrm_statistics_fini(struct net * net)4014 static void xfrm_statistics_fini(struct net *net)
4015 {
4016 }
4017 #endif
4018 
xfrm_policy_init(struct net * net)4019 static int __net_init xfrm_policy_init(struct net *net)
4020 {
4021 	unsigned int hmask, sz;
4022 	int dir, err;
4023 
4024 	if (net_eq(net, &init_net)) {
4025 		xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
4026 					   sizeof(struct xfrm_dst),
4027 					   0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
4028 					   NULL);
4029 		err = rhashtable_init(&xfrm_policy_inexact_table,
4030 				      &xfrm_pol_inexact_params);
4031 		BUG_ON(err);
4032 	}
4033 
4034 	hmask = 8 - 1;
4035 	sz = (hmask+1) * sizeof(struct hlist_head);
4036 
4037 	net->xfrm.policy_byidx = xfrm_hash_alloc(sz);
4038 	if (!net->xfrm.policy_byidx)
4039 		goto out_byidx;
4040 	net->xfrm.policy_idx_hmask = hmask;
4041 
4042 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
4043 		struct xfrm_policy_hash *htab;
4044 
4045 		net->xfrm.policy_count[dir] = 0;
4046 		net->xfrm.policy_count[XFRM_POLICY_MAX + dir] = 0;
4047 		INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
4048 
4049 		htab = &net->xfrm.policy_bydst[dir];
4050 		htab->table = xfrm_hash_alloc(sz);
4051 		if (!htab->table)
4052 			goto out_bydst;
4053 		htab->hmask = hmask;
4054 		htab->dbits4 = 32;
4055 		htab->sbits4 = 32;
4056 		htab->dbits6 = 128;
4057 		htab->sbits6 = 128;
4058 	}
4059 	net->xfrm.policy_hthresh.lbits4 = 32;
4060 	net->xfrm.policy_hthresh.rbits4 = 32;
4061 	net->xfrm.policy_hthresh.lbits6 = 128;
4062 	net->xfrm.policy_hthresh.rbits6 = 128;
4063 
4064 	seqlock_init(&net->xfrm.policy_hthresh.lock);
4065 
4066 	INIT_LIST_HEAD(&net->xfrm.policy_all);
4067 	INIT_LIST_HEAD(&net->xfrm.inexact_bins);
4068 	INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
4069 	INIT_WORK(&net->xfrm.policy_hthresh.work, xfrm_hash_rebuild);
4070 	return 0;
4071 
4072 out_bydst:
4073 	for (dir--; dir >= 0; dir--) {
4074 		struct xfrm_policy_hash *htab;
4075 
4076 		htab = &net->xfrm.policy_bydst[dir];
4077 		xfrm_hash_free(htab->table, sz);
4078 	}
4079 	xfrm_hash_free(net->xfrm.policy_byidx, sz);
4080 out_byidx:
4081 	return -ENOMEM;
4082 }
4083 
xfrm_policy_fini(struct net * net)4084 static void xfrm_policy_fini(struct net *net)
4085 {
4086 	struct xfrm_pol_inexact_bin *b, *t;
4087 	unsigned int sz;
4088 	int dir;
4089 
4090 	flush_work(&net->xfrm.policy_hash_work);
4091 #ifdef CONFIG_XFRM_SUB_POLICY
4092 	xfrm_policy_flush(net, XFRM_POLICY_TYPE_SUB, false);
4093 #endif
4094 	xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, false);
4095 
4096 	WARN_ON(!list_empty(&net->xfrm.policy_all));
4097 
4098 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
4099 		struct xfrm_policy_hash *htab;
4100 
4101 		WARN_ON(!hlist_empty(&net->xfrm.policy_inexact[dir]));
4102 
4103 		htab = &net->xfrm.policy_bydst[dir];
4104 		sz = (htab->hmask + 1) * sizeof(struct hlist_head);
4105 		WARN_ON(!hlist_empty(htab->table));
4106 		xfrm_hash_free(htab->table, sz);
4107 	}
4108 
4109 	sz = (net->xfrm.policy_idx_hmask + 1) * sizeof(struct hlist_head);
4110 	WARN_ON(!hlist_empty(net->xfrm.policy_byidx));
4111 	xfrm_hash_free(net->xfrm.policy_byidx, sz);
4112 
4113 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
4114 	list_for_each_entry_safe(b, t, &net->xfrm.inexact_bins, inexact_bins)
4115 		__xfrm_policy_inexact_prune_bin(b, true);
4116 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
4117 }
4118 
xfrm_net_init(struct net * net)4119 static int __net_init xfrm_net_init(struct net *net)
4120 {
4121 	int rv;
4122 
4123 	/* Initialize the per-net locks here */
4124 	spin_lock_init(&net->xfrm.xfrm_state_lock);
4125 	spin_lock_init(&net->xfrm.xfrm_policy_lock);
4126 	seqcount_spinlock_init(&net->xfrm.xfrm_policy_hash_generation, &net->xfrm.xfrm_policy_lock);
4127 	mutex_init(&net->xfrm.xfrm_cfg_mutex);
4128 	net->xfrm.policy_default[XFRM_POLICY_IN] = XFRM_USERPOLICY_ACCEPT;
4129 	net->xfrm.policy_default[XFRM_POLICY_FWD] = XFRM_USERPOLICY_ACCEPT;
4130 	net->xfrm.policy_default[XFRM_POLICY_OUT] = XFRM_USERPOLICY_ACCEPT;
4131 
4132 	rv = xfrm_statistics_init(net);
4133 	if (rv < 0)
4134 		goto out_statistics;
4135 	rv = xfrm_state_init(net);
4136 	if (rv < 0)
4137 		goto out_state;
4138 	rv = xfrm_policy_init(net);
4139 	if (rv < 0)
4140 		goto out_policy;
4141 	rv = xfrm_sysctl_init(net);
4142 	if (rv < 0)
4143 		goto out_sysctl;
4144 
4145 	return 0;
4146 
4147 out_sysctl:
4148 	xfrm_policy_fini(net);
4149 out_policy:
4150 	xfrm_state_fini(net);
4151 out_state:
4152 	xfrm_statistics_fini(net);
4153 out_statistics:
4154 	return rv;
4155 }
4156 
xfrm_net_exit(struct net * net)4157 static void __net_exit xfrm_net_exit(struct net *net)
4158 {
4159 	xfrm_sysctl_fini(net);
4160 	xfrm_policy_fini(net);
4161 	xfrm_state_fini(net);
4162 	xfrm_statistics_fini(net);
4163 }
4164 
4165 static struct pernet_operations __net_initdata xfrm_net_ops = {
4166 	.init = xfrm_net_init,
4167 	.exit = xfrm_net_exit,
4168 };
4169 
xfrm_init(void)4170 void __init xfrm_init(void)
4171 {
4172 	register_pernet_subsys(&xfrm_net_ops);
4173 	xfrm_dev_init();
4174 	xfrm_input_init();
4175 
4176 #ifdef CONFIG_XFRM_ESPINTCP
4177 	espintcp_init();
4178 #endif
4179 }
4180 
4181 #ifdef CONFIG_AUDITSYSCALL
xfrm_audit_common_policyinfo(struct xfrm_policy * xp,struct audit_buffer * audit_buf)4182 static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
4183 					 struct audit_buffer *audit_buf)
4184 {
4185 	struct xfrm_sec_ctx *ctx = xp->security;
4186 	struct xfrm_selector *sel = &xp->selector;
4187 
4188 	if (ctx)
4189 		audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
4190 				 ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str);
4191 
4192 	switch (sel->family) {
4193 	case AF_INET:
4194 		audit_log_format(audit_buf, " src=%pI4", &sel->saddr.a4);
4195 		if (sel->prefixlen_s != 32)
4196 			audit_log_format(audit_buf, " src_prefixlen=%d",
4197 					 sel->prefixlen_s);
4198 		audit_log_format(audit_buf, " dst=%pI4", &sel->daddr.a4);
4199 		if (sel->prefixlen_d != 32)
4200 			audit_log_format(audit_buf, " dst_prefixlen=%d",
4201 					 sel->prefixlen_d);
4202 		break;
4203 	case AF_INET6:
4204 		audit_log_format(audit_buf, " src=%pI6", sel->saddr.a6);
4205 		if (sel->prefixlen_s != 128)
4206 			audit_log_format(audit_buf, " src_prefixlen=%d",
4207 					 sel->prefixlen_s);
4208 		audit_log_format(audit_buf, " dst=%pI6", sel->daddr.a6);
4209 		if (sel->prefixlen_d != 128)
4210 			audit_log_format(audit_buf, " dst_prefixlen=%d",
4211 					 sel->prefixlen_d);
4212 		break;
4213 	}
4214 }
4215 
xfrm_audit_policy_add(struct xfrm_policy * xp,int result,bool task_valid)4216 void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid)
4217 {
4218 	struct audit_buffer *audit_buf;
4219 
4220 	audit_buf = xfrm_audit_start("SPD-add");
4221 	if (audit_buf == NULL)
4222 		return;
4223 	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
4224 	audit_log_format(audit_buf, " res=%u", result);
4225 	xfrm_audit_common_policyinfo(xp, audit_buf);
4226 	audit_log_end(audit_buf);
4227 }
4228 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
4229 
xfrm_audit_policy_delete(struct xfrm_policy * xp,int result,bool task_valid)4230 void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
4231 			      bool task_valid)
4232 {
4233 	struct audit_buffer *audit_buf;
4234 
4235 	audit_buf = xfrm_audit_start("SPD-delete");
4236 	if (audit_buf == NULL)
4237 		return;
4238 	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
4239 	audit_log_format(audit_buf, " res=%u", result);
4240 	xfrm_audit_common_policyinfo(xp, audit_buf);
4241 	audit_log_end(audit_buf);
4242 }
4243 EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
4244 #endif
4245 
4246 #ifdef CONFIG_XFRM_MIGRATE
xfrm_migrate_selector_match(const struct xfrm_selector * sel_cmp,const struct xfrm_selector * sel_tgt)4247 static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp,
4248 					const struct xfrm_selector *sel_tgt)
4249 {
4250 	if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
4251 		if (sel_tgt->family == sel_cmp->family &&
4252 		    xfrm_addr_equal(&sel_tgt->daddr, &sel_cmp->daddr,
4253 				    sel_cmp->family) &&
4254 		    xfrm_addr_equal(&sel_tgt->saddr, &sel_cmp->saddr,
4255 				    sel_cmp->family) &&
4256 		    sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
4257 		    sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
4258 			return true;
4259 		}
4260 	} else {
4261 		if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
4262 			return true;
4263 		}
4264 	}
4265 	return false;
4266 }
4267 
xfrm_migrate_policy_find(const struct xfrm_selector * sel,u8 dir,u8 type,struct net * net,u32 if_id)4268 static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector *sel,
4269 						    u8 dir, u8 type, struct net *net, u32 if_id)
4270 {
4271 	struct xfrm_policy *pol, *ret = NULL;
4272 	struct hlist_head *chain;
4273 	u32 priority = ~0U;
4274 
4275 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
4276 	chain = policy_hash_direct(net, &sel->daddr, &sel->saddr, sel->family, dir);
4277 	hlist_for_each_entry(pol, chain, bydst) {
4278 		if ((if_id == 0 || pol->if_id == if_id) &&
4279 		    xfrm_migrate_selector_match(sel, &pol->selector) &&
4280 		    pol->type == type) {
4281 			ret = pol;
4282 			priority = ret->priority;
4283 			break;
4284 		}
4285 	}
4286 	chain = &net->xfrm.policy_inexact[dir];
4287 	hlist_for_each_entry(pol, chain, bydst_inexact_list) {
4288 		if ((pol->priority >= priority) && ret)
4289 			break;
4290 
4291 		if ((if_id == 0 || pol->if_id == if_id) &&
4292 		    xfrm_migrate_selector_match(sel, &pol->selector) &&
4293 		    pol->type == type) {
4294 			ret = pol;
4295 			break;
4296 		}
4297 	}
4298 
4299 	xfrm_pol_hold(ret);
4300 
4301 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
4302 
4303 	return ret;
4304 }
4305 
migrate_tmpl_match(const struct xfrm_migrate * m,const struct xfrm_tmpl * t)4306 static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t)
4307 {
4308 	int match = 0;
4309 
4310 	if (t->mode == m->mode && t->id.proto == m->proto &&
4311 	    (m->reqid == 0 || t->reqid == m->reqid)) {
4312 		switch (t->mode) {
4313 		case XFRM_MODE_TUNNEL:
4314 		case XFRM_MODE_BEET:
4315 			if (xfrm_addr_equal(&t->id.daddr, &m->old_daddr,
4316 					    m->old_family) &&
4317 			    xfrm_addr_equal(&t->saddr, &m->old_saddr,
4318 					    m->old_family)) {
4319 				match = 1;
4320 			}
4321 			break;
4322 		case XFRM_MODE_TRANSPORT:
4323 			/* in case of transport mode, template does not store
4324 			   any IP addresses, hence we just compare mode and
4325 			   protocol */
4326 			match = 1;
4327 			break;
4328 		default:
4329 			break;
4330 		}
4331 	}
4332 	return match;
4333 }
4334 
4335 /* update endpoint address(es) of template(s) */
xfrm_policy_migrate(struct xfrm_policy * pol,struct xfrm_migrate * m,int num_migrate)4336 static int xfrm_policy_migrate(struct xfrm_policy *pol,
4337 			       struct xfrm_migrate *m, int num_migrate)
4338 {
4339 	struct xfrm_migrate *mp;
4340 	int i, j, n = 0;
4341 
4342 	write_lock_bh(&pol->lock);
4343 	if (unlikely(pol->walk.dead)) {
4344 		/* target policy has been deleted */
4345 		write_unlock_bh(&pol->lock);
4346 		return -ENOENT;
4347 	}
4348 
4349 	for (i = 0; i < pol->xfrm_nr; i++) {
4350 		for (j = 0, mp = m; j < num_migrate; j++, mp++) {
4351 			if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
4352 				continue;
4353 			n++;
4354 			if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
4355 			    pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
4356 				continue;
4357 			/* update endpoints */
4358 			memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
4359 			       sizeof(pol->xfrm_vec[i].id.daddr));
4360 			memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
4361 			       sizeof(pol->xfrm_vec[i].saddr));
4362 			pol->xfrm_vec[i].encap_family = mp->new_family;
4363 			/* flush bundles */
4364 			atomic_inc(&pol->genid);
4365 		}
4366 	}
4367 
4368 	write_unlock_bh(&pol->lock);
4369 
4370 	if (!n)
4371 		return -ENODATA;
4372 
4373 	return 0;
4374 }
4375 
xfrm_migrate_check(const struct xfrm_migrate * m,int num_migrate)4376 static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate)
4377 {
4378 	int i, j;
4379 
4380 	if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
4381 		return -EINVAL;
4382 
4383 	for (i = 0; i < num_migrate; i++) {
4384 		if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
4385 		    xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
4386 			return -EINVAL;
4387 
4388 		/* check if there is any duplicated entry */
4389 		for (j = i + 1; j < num_migrate; j++) {
4390 			if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
4391 				    sizeof(m[i].old_daddr)) &&
4392 			    !memcmp(&m[i].old_saddr, &m[j].old_saddr,
4393 				    sizeof(m[i].old_saddr)) &&
4394 			    m[i].proto == m[j].proto &&
4395 			    m[i].mode == m[j].mode &&
4396 			    m[i].reqid == m[j].reqid &&
4397 			    m[i].old_family == m[j].old_family)
4398 				return -EINVAL;
4399 		}
4400 	}
4401 
4402 	return 0;
4403 }
4404 
xfrm_migrate(const struct xfrm_selector * sel,u8 dir,u8 type,struct xfrm_migrate * m,int num_migrate,struct xfrm_kmaddress * k,struct net * net,struct xfrm_encap_tmpl * encap,u32 if_id)4405 int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
4406 		 struct xfrm_migrate *m, int num_migrate,
4407 		 struct xfrm_kmaddress *k, struct net *net,
4408 		 struct xfrm_encap_tmpl *encap, u32 if_id)
4409 {
4410 	int i, err, nx_cur = 0, nx_new = 0;
4411 	struct xfrm_policy *pol = NULL;
4412 	struct xfrm_state *x, *xc;
4413 	struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
4414 	struct xfrm_state *x_new[XFRM_MAX_DEPTH];
4415 	struct xfrm_migrate *mp;
4416 
4417 	/* Stage 0 - sanity checks */
4418 	if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
4419 		goto out;
4420 
4421 	if (dir >= XFRM_POLICY_MAX) {
4422 		err = -EINVAL;
4423 		goto out;
4424 	}
4425 
4426 	/* Stage 1 - find policy */
4427 	if ((pol = xfrm_migrate_policy_find(sel, dir, type, net, if_id)) == NULL) {
4428 		err = -ENOENT;
4429 		goto out;
4430 	}
4431 
4432 	/* Stage 2 - find and update state(s) */
4433 	for (i = 0, mp = m; i < num_migrate; i++, mp++) {
4434 		if ((x = xfrm_migrate_state_find(mp, net, if_id))) {
4435 			x_cur[nx_cur] = x;
4436 			nx_cur++;
4437 			xc = xfrm_state_migrate(x, mp, encap);
4438 			if (xc) {
4439 				x_new[nx_new] = xc;
4440 				nx_new++;
4441 			} else {
4442 				err = -ENODATA;
4443 				goto restore_state;
4444 			}
4445 		}
4446 	}
4447 
4448 	/* Stage 3 - update policy */
4449 	if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
4450 		goto restore_state;
4451 
4452 	/* Stage 4 - delete old state(s) */
4453 	if (nx_cur) {
4454 		xfrm_states_put(x_cur, nx_cur);
4455 		xfrm_states_delete(x_cur, nx_cur);
4456 	}
4457 
4458 	/* Stage 5 - announce */
4459 	km_migrate(sel, dir, type, m, num_migrate, k, encap);
4460 
4461 	xfrm_pol_put(pol);
4462 
4463 	return 0;
4464 out:
4465 	return err;
4466 
4467 restore_state:
4468 	if (pol)
4469 		xfrm_pol_put(pol);
4470 	if (nx_cur)
4471 		xfrm_states_put(x_cur, nx_cur);
4472 	if (nx_new)
4473 		xfrm_states_delete(x_new, nx_new);
4474 
4475 	return err;
4476 }
4477 EXPORT_SYMBOL(xfrm_migrate);
4478 #endif
4479