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bpf: Prevent memory disambiguation attack
[linux/fpc-iii.git] / net / xfrm / xfrm_policy.c
blob625b3fca570419455656021b61bf132fb08e8b2a
1 /*
2 * xfrm_policy.c
3 *
4 * Changes:
5 * Mitsuru KANDA @USAGI
6 * Kazunori MIYAZAWA @USAGI
7 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
8 * IPv6 support
9 * Kazunori MIYAZAWA @USAGI
10 * YOSHIFUJI Hideaki
11 * Split up af-specific portion
12 * Derek Atkins <derek@ihtfp.com> Add the post_input processor
13 *
14 */
15
16 #include <linux/err.h>
17 #include <linux/slab.h>
18 #include <linux/kmod.h>
19 #include <linux/list.h>
20 #include <linux/spinlock.h>
21 #include <linux/workqueue.h>
22 #include <linux/notifier.h>
23 #include <linux/netdevice.h>
24 #include <linux/netfilter.h>
25 #include <linux/module.h>
26 #include <linux/cache.h>
27 #include <linux/cpu.h>
28 #include <linux/audit.h>
29 #include <net/dst.h>
30 #include <net/flow.h>
31 #include <net/xfrm.h>
32 #include <net/ip.h>
33 #ifdef CONFIG_XFRM_STATISTICS
34 #include <net/snmp.h>
35 #endif
36
37 #include "xfrm_hash.h"
38
39 #define XFRM_QUEUE_TMO_MIN ((unsigned)(HZ/10))
40 #define XFRM_QUEUE_TMO_MAX ((unsigned)(60*HZ))
41 #define XFRM_MAX_QUEUE_LEN 100
42
43 struct xfrm_flo {
44 struct dst_entry *dst_orig;
45 u8 flags;
46 };
47
48 static DEFINE_PER_CPU(struct xfrm_dst *, xfrm_last_dst);
49 static struct work_struct *xfrm_pcpu_work __read_mostly;
50 static DEFINE_SPINLOCK(xfrm_policy_afinfo_lock);
51 static struct xfrm_policy_afinfo const __rcu *xfrm_policy_afinfo[AF_INET6 + 1]
52 __read_mostly;
53
54 static struct kmem_cache *xfrm_dst_cache __read_mostly;
55 static __read_mostly seqcount_t xfrm_policy_hash_generation;
56
57 static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr);
58 static int stale_bundle(struct dst_entry *dst);
59 static int xfrm_bundle_ok(struct xfrm_dst *xdst);
60 static void xfrm_policy_queue_process(struct timer_list *t);
61
62 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir);
63 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
64 int dir);
65
66 static inline bool xfrm_pol_hold_rcu(struct xfrm_policy *policy)
67 {
68 return refcount_inc_not_zero(&policy->refcnt);
69 }
70
71 static inline bool
72 __xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
73 {
74 const struct flowi4 *fl4 = &fl->u.ip4;
75
76 return addr4_match(fl4->daddr, sel->daddr.a4, sel->prefixlen_d) &&
77 addr4_match(fl4->saddr, sel->saddr.a4, sel->prefixlen_s) &&
78 !((xfrm_flowi_dport(fl, &fl4->uli) ^ sel->dport) & sel->dport_mask) &&
79 !((xfrm_flowi_sport(fl, &fl4->uli) ^ sel->sport) & sel->sport_mask) &&
80 (fl4->flowi4_proto == sel->proto || !sel->proto) &&
81 (fl4->flowi4_oif == sel->ifindex || !sel->ifindex);
82 }
83
84 static inline bool
85 __xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
86 {
87 const struct flowi6 *fl6 = &fl->u.ip6;
88
89 return addr_match(&fl6->daddr, &sel->daddr, sel->prefixlen_d) &&
90 addr_match(&fl6->saddr, &sel->saddr, sel->prefixlen_s) &&
91 !((xfrm_flowi_dport(fl, &fl6->uli) ^ sel->dport) & sel->dport_mask) &&
92 !((xfrm_flowi_sport(fl, &fl6->uli) ^ sel->sport) & sel->sport_mask) &&
93 (fl6->flowi6_proto == sel->proto || !sel->proto) &&
94 (fl6->flowi6_oif == sel->ifindex || !sel->ifindex);
95 }
96
97 bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl,
98 unsigned short family)
99 {
100 switch (family) {
101 case AF_INET:
102 return __xfrm4_selector_match(sel, fl);
103 case AF_INET6:
104 return __xfrm6_selector_match(sel, fl);
105 }
106 return false;
107 }
108
109 static const struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
110 {
111 const struct xfrm_policy_afinfo *afinfo;
112
113 if (unlikely(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
114 return NULL;
115 rcu_read_lock();
116 afinfo = rcu_dereference(xfrm_policy_afinfo[family]);
117 if (unlikely(!afinfo))
118 rcu_read_unlock();
119 return afinfo;
120 }
121
122 struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos, int oif,
123 const xfrm_address_t *saddr,
124 const xfrm_address_t *daddr,
125 int family, u32 mark)
126 {
127 const struct xfrm_policy_afinfo *afinfo;
128 struct dst_entry *dst;
129
130 afinfo = xfrm_policy_get_afinfo(family);
131 if (unlikely(afinfo == NULL))
132 return ERR_PTR(-EAFNOSUPPORT);
133
134 dst = afinfo->dst_lookup(net, tos, oif, saddr, daddr, mark);
135
136 rcu_read_unlock();
137
138 return dst;
139 }
140 EXPORT_SYMBOL(__xfrm_dst_lookup);
141
142 static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x,
143 int tos, int oif,
144 xfrm_address_t *prev_saddr,
145 xfrm_address_t *prev_daddr,
146 int family, u32 mark)
147 {
148 struct net *net = xs_net(x);
149 xfrm_address_t *saddr = &x->props.saddr;
150 xfrm_address_t *daddr = &x->id.daddr;
151 struct dst_entry *dst;
152
153 if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) {
154 saddr = x->coaddr;
155 daddr = prev_daddr;
156 }
157 if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) {
158 saddr = prev_saddr;
159 daddr = x->coaddr;
160 }
161
162 dst = __xfrm_dst_lookup(net, tos, oif, saddr, daddr, family, mark);
163
164 if (!IS_ERR(dst)) {
165 if (prev_saddr != saddr)
166 memcpy(prev_saddr, saddr, sizeof(*prev_saddr));
167 if (prev_daddr != daddr)
168 memcpy(prev_daddr, daddr, sizeof(*prev_daddr));
169 }
170
171 return dst;
172 }
173
174 static inline unsigned long make_jiffies(long secs)
175 {
176 if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
177 return MAX_SCHEDULE_TIMEOUT-1;
178 else
179 return secs*HZ;
180 }
181
182 static void xfrm_policy_timer(struct timer_list *t)
183 {
184 struct xfrm_policy *xp = from_timer(xp, t, timer);
185 unsigned long now = get_seconds();
186 long next = LONG_MAX;
187 int warn = 0;
188 int dir;
189
190 read_lock(&xp->lock);
191
192 if (unlikely(xp->walk.dead))
193 goto out;
194
195 dir = xfrm_policy_id2dir(xp->index);
196
197 if (xp->lft.hard_add_expires_seconds) {
198 long tmo = xp->lft.hard_add_expires_seconds +
199 xp->curlft.add_time - now;
200 if (tmo <= 0)
201 goto expired;
202 if (tmo < next)
203 next = tmo;
204 }
205 if (xp->lft.hard_use_expires_seconds) {
206 long tmo = xp->lft.hard_use_expires_seconds +
207 (xp->curlft.use_time ? : xp->curlft.add_time) - now;
208 if (tmo <= 0)
209 goto expired;
210 if (tmo < next)
211 next = tmo;
212 }
213 if (xp->lft.soft_add_expires_seconds) {
214 long tmo = xp->lft.soft_add_expires_seconds +
215 xp->curlft.add_time - now;
216 if (tmo <= 0) {
217 warn = 1;
218 tmo = XFRM_KM_TIMEOUT;
219 }
220 if (tmo < next)
221 next = tmo;
222 }
223 if (xp->lft.soft_use_expires_seconds) {
224 long tmo = xp->lft.soft_use_expires_seconds +
225 (xp->curlft.use_time ? : xp->curlft.add_time) - now;
226 if (tmo <= 0) {
227 warn = 1;
228 tmo = XFRM_KM_TIMEOUT;
229 }
230 if (tmo < next)
231 next = tmo;
232 }
233
234 if (warn)
235 km_policy_expired(xp, dir, 0, 0);
236 if (next != LONG_MAX &&
237 !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
238 xfrm_pol_hold(xp);
239
240 out:
241 read_unlock(&xp->lock);
242 xfrm_pol_put(xp);
243 return;
244
245 expired:
246 read_unlock(&xp->lock);
247 if (!xfrm_policy_delete(xp, dir))
248 km_policy_expired(xp, dir, 1, 0);
249 xfrm_pol_put(xp);
250 }
251
252 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
253 * SPD calls.
254 */
255
256 struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
257 {
258 struct xfrm_policy *policy;
259
260 policy = kzalloc(sizeof(struct xfrm_policy), gfp);
261
262 if (policy) {
263 write_pnet(&policy->xp_net, net);
264 INIT_LIST_HEAD(&policy->walk.all);
265 INIT_HLIST_NODE(&policy->bydst);
266 INIT_HLIST_NODE(&policy->byidx);
267 rwlock_init(&policy->lock);
268 refcount_set(&policy->refcnt, 1);
269 skb_queue_head_init(&policy->polq.hold_queue);
270 timer_setup(&policy->timer, xfrm_policy_timer, 0);
271 timer_setup(&policy->polq.hold_timer,
272 xfrm_policy_queue_process, 0);
273 }
274 return policy;
275 }
276 EXPORT_SYMBOL(xfrm_policy_alloc);
277
278 static void xfrm_policy_destroy_rcu(struct rcu_head *head)
279 {
280 struct xfrm_policy *policy = container_of(head, struct xfrm_policy, rcu);
281
282 security_xfrm_policy_free(policy->security);
283 kfree(policy);
284 }
285
286 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
287
288 void xfrm_policy_destroy(struct xfrm_policy *policy)
289 {
290 BUG_ON(!policy->walk.dead);
291
292 if (del_timer(&policy->timer) || del_timer(&policy->polq.hold_timer))
293 BUG();
294
295 call_rcu(&policy->rcu, xfrm_policy_destroy_rcu);
296 }
297 EXPORT_SYMBOL(xfrm_policy_destroy);
298
299 /* Rule must be locked. Release descendant resources, announce
300 * entry dead. The rule must be unlinked from lists to the moment.
301 */
302
303 static void xfrm_policy_kill(struct xfrm_policy *policy)
304 {
305 policy->walk.dead = 1;
306
307 atomic_inc(&policy->genid);
308
309 if (del_timer(&policy->polq.hold_timer))
310 xfrm_pol_put(policy);
311 skb_queue_purge(&policy->polq.hold_queue);
312
313 if (del_timer(&policy->timer))
314 xfrm_pol_put(policy);
315
316 xfrm_pol_put(policy);
317 }
318
319 static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
320
321 static inline unsigned int idx_hash(struct net *net, u32 index)
322 {
323 return __idx_hash(index, net->xfrm.policy_idx_hmask);
324 }
325
326 /* calculate policy hash thresholds */
327 static void __get_hash_thresh(struct net *net,
328 unsigned short family, int dir,
329 u8 *dbits, u8 *sbits)
330 {
331 switch (family) {
332 case AF_INET:
333 *dbits = net->xfrm.policy_bydst[dir].dbits4;
334 *sbits = net->xfrm.policy_bydst[dir].sbits4;
335 break;
336
337 case AF_INET6:
338 *dbits = net->xfrm.policy_bydst[dir].dbits6;
339 *sbits = net->xfrm.policy_bydst[dir].sbits6;
340 break;
341
342 default:
343 *dbits = 0;
344 *sbits = 0;
345 }
346 }
347
348 static struct hlist_head *policy_hash_bysel(struct net *net,
349 const struct xfrm_selector *sel,
350 unsigned short family, int dir)
351 {
352 unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
353 unsigned int hash;
354 u8 dbits;
355 u8 sbits;
356
357 __get_hash_thresh(net, family, dir, &dbits, &sbits);
358 hash = __sel_hash(sel, family, hmask, dbits, sbits);
359
360 if (hash == hmask + 1)
361 return &net->xfrm.policy_inexact[dir];
362
363 return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
364 lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
365 }
366
367 static struct hlist_head *policy_hash_direct(struct net *net,
368 const xfrm_address_t *daddr,
369 const xfrm_address_t *saddr,
370 unsigned short family, int dir)
371 {
372 unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
373 unsigned int hash;
374 u8 dbits;
375 u8 sbits;
376
377 __get_hash_thresh(net, family, dir, &dbits, &sbits);
378 hash = __addr_hash(daddr, saddr, family, hmask, dbits, sbits);
379
380 return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
381 lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
382 }
383
384 static void xfrm_dst_hash_transfer(struct net *net,
385 struct hlist_head *list,
386 struct hlist_head *ndsttable,
387 unsigned int nhashmask,
388 int dir)
389 {
390 struct hlist_node *tmp, *entry0 = NULL;
391 struct xfrm_policy *pol;
392 unsigned int h0 = 0;
393 u8 dbits;
394 u8 sbits;
395
396 redo:
397 hlist_for_each_entry_safe(pol, tmp, list, bydst) {
398 unsigned int h;
399
400 __get_hash_thresh(net, pol->family, dir, &dbits, &sbits);
401 h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
402 pol->family, nhashmask, dbits, sbits);
403 if (!entry0) {
404 hlist_del_rcu(&pol->bydst);
405 hlist_add_head_rcu(&pol->bydst, ndsttable + h);
406 h0 = h;
407 } else {
408 if (h != h0)
409 continue;
410 hlist_del_rcu(&pol->bydst);
411 hlist_add_behind_rcu(&pol->bydst, entry0);
412 }
413 entry0 = &pol->bydst;
414 }
415 if (!hlist_empty(list)) {
416 entry0 = NULL;
417 goto redo;
418 }
419 }
420
421 static void xfrm_idx_hash_transfer(struct hlist_head *list,
422 struct hlist_head *nidxtable,
423 unsigned int nhashmask)
424 {
425 struct hlist_node *tmp;
426 struct xfrm_policy *pol;
427
428 hlist_for_each_entry_safe(pol, tmp, list, byidx) {
429 unsigned int h;
430
431 h = __idx_hash(pol->index, nhashmask);
432 hlist_add_head(&pol->byidx, nidxtable+h);
433 }
434 }
435
436 static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
437 {
438 return ((old_hmask + 1) << 1) - 1;
439 }
440
441 static void xfrm_bydst_resize(struct net *net, int dir)
442 {
443 unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
444 unsigned int nhashmask = xfrm_new_hash_mask(hmask);
445 unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
446 struct hlist_head *ndst = xfrm_hash_alloc(nsize);
447 struct hlist_head *odst;
448 int i;
449
450 if (!ndst)
451 return;
452
453 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
454 write_seqcount_begin(&xfrm_policy_hash_generation);
455
456 odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
457 lockdep_is_held(&net->xfrm.xfrm_policy_lock));
458
459 odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
460 lockdep_is_held(&net->xfrm.xfrm_policy_lock));
461
462 for (i = hmask; i >= 0; i--)
463 xfrm_dst_hash_transfer(net, odst + i, ndst, nhashmask, dir);
464
465 rcu_assign_pointer(net->xfrm.policy_bydst[dir].table, ndst);
466 net->xfrm.policy_bydst[dir].hmask = nhashmask;
467
468 write_seqcount_end(&xfrm_policy_hash_generation);
469 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
470
471 synchronize_rcu();
472
473 xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
474 }
475
476 static void xfrm_byidx_resize(struct net *net, int total)
477 {
478 unsigned int hmask = net->xfrm.policy_idx_hmask;
479 unsigned int nhashmask = xfrm_new_hash_mask(hmask);
480 unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
481 struct hlist_head *oidx = net->xfrm.policy_byidx;
482 struct hlist_head *nidx = xfrm_hash_alloc(nsize);
483 int i;
484
485 if (!nidx)
486 return;
487
488 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
489
490 for (i = hmask; i >= 0; i--)
491 xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
492
493 net->xfrm.policy_byidx = nidx;
494 net->xfrm.policy_idx_hmask = nhashmask;
495
496 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
497
498 xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
499 }
500
501 static inline int xfrm_bydst_should_resize(struct net *net, int dir, int *total)
502 {
503 unsigned int cnt = net->xfrm.policy_count[dir];
504 unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
505
506 if (total)
507 *total += cnt;
508
509 if ((hmask + 1) < xfrm_policy_hashmax &&
510 cnt > hmask)
511 return 1;
512
513 return 0;
514 }
515
516 static inline int xfrm_byidx_should_resize(struct net *net, int total)
517 {
518 unsigned int hmask = net->xfrm.policy_idx_hmask;
519
520 if ((hmask + 1) < xfrm_policy_hashmax &&
521 total > hmask)
522 return 1;
523
524 return 0;
525 }
526
527 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
528 {
529 si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
530 si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
531 si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
532 si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
533 si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
534 si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
535 si->spdhcnt = net->xfrm.policy_idx_hmask;
536 si->spdhmcnt = xfrm_policy_hashmax;
537 }
538 EXPORT_SYMBOL(xfrm_spd_getinfo);
539
540 static DEFINE_MUTEX(hash_resize_mutex);
541 static void xfrm_hash_resize(struct work_struct *work)
542 {
543 struct net *net = container_of(work, struct net, xfrm.policy_hash_work);
544 int dir, total;
545
546 mutex_lock(&hash_resize_mutex);
547
548 total = 0;
549 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
550 if (xfrm_bydst_should_resize(net, dir, &total))
551 xfrm_bydst_resize(net, dir);
552 }
553 if (xfrm_byidx_should_resize(net, total))
554 xfrm_byidx_resize(net, total);
555
556 mutex_unlock(&hash_resize_mutex);
557 }
558
559 static void xfrm_hash_rebuild(struct work_struct *work)
560 {
561 struct net *net = container_of(work, struct net,
562 xfrm.policy_hthresh.work);
563 unsigned int hmask;
564 struct xfrm_policy *pol;
565 struct xfrm_policy *policy;
566 struct hlist_head *chain;
567 struct hlist_head *odst;
568 struct hlist_node *newpos;
569 int i;
570 int dir;
571 unsigned seq;
572 u8 lbits4, rbits4, lbits6, rbits6;
573
574 mutex_lock(&hash_resize_mutex);
575
576 /* read selector prefixlen thresholds */
577 do {
578 seq = read_seqbegin(&net->xfrm.policy_hthresh.lock);
579
580 lbits4 = net->xfrm.policy_hthresh.lbits4;
581 rbits4 = net->xfrm.policy_hthresh.rbits4;
582 lbits6 = net->xfrm.policy_hthresh.lbits6;
583 rbits6 = net->xfrm.policy_hthresh.rbits6;
584 } while (read_seqretry(&net->xfrm.policy_hthresh.lock, seq));
585
586 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
587
588 /* reset the bydst and inexact table in all directions */
589 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
590 INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
591 hmask = net->xfrm.policy_bydst[dir].hmask;
592 odst = net->xfrm.policy_bydst[dir].table;
593 for (i = hmask; i >= 0; i--)
594 INIT_HLIST_HEAD(odst + i);
595 if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
596 /* dir out => dst = remote, src = local */
597 net->xfrm.policy_bydst[dir].dbits4 = rbits4;
598 net->xfrm.policy_bydst[dir].sbits4 = lbits4;
599 net->xfrm.policy_bydst[dir].dbits6 = rbits6;
600 net->xfrm.policy_bydst[dir].sbits6 = lbits6;
601 } else {
602 /* dir in/fwd => dst = local, src = remote */
603 net->xfrm.policy_bydst[dir].dbits4 = lbits4;
604 net->xfrm.policy_bydst[dir].sbits4 = rbits4;
605 net->xfrm.policy_bydst[dir].dbits6 = lbits6;
606 net->xfrm.policy_bydst[dir].sbits6 = rbits6;
607 }
608 }
609
610 /* re-insert all policies by order of creation */
611 list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
612 if (policy->walk.dead ||
613 xfrm_policy_id2dir(policy->index) >= XFRM_POLICY_MAX) {
614 /* skip socket policies */
615 continue;
616 }
617 newpos = NULL;
618 chain = policy_hash_bysel(net, &policy->selector,
619 policy->family,
620 xfrm_policy_id2dir(policy->index));
621 hlist_for_each_entry(pol, chain, bydst) {
622 if (policy->priority >= pol->priority)
623 newpos = &pol->bydst;
624 else
625 break;
626 }
627 if (newpos)
628 hlist_add_behind(&policy->bydst, newpos);
629 else
630 hlist_add_head(&policy->bydst, chain);
631 }
632
633 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
634
635 mutex_unlock(&hash_resize_mutex);
636 }
637
638 void xfrm_policy_hash_rebuild(struct net *net)
639 {
640 schedule_work(&net->xfrm.policy_hthresh.work);
641 }
642 EXPORT_SYMBOL(xfrm_policy_hash_rebuild);
643
644 /* Generate new index... KAME seems to generate them ordered by cost
645 * of an absolute inpredictability of ordering of rules. This will not pass. */
646 static u32 xfrm_gen_index(struct net *net, int dir, u32 index)
647 {
648 static u32 idx_generator;
649
650 for (;;) {
651 struct hlist_head *list;
652 struct xfrm_policy *p;
653 u32 idx;
654 int found;
655
656 if (!index) {
657 idx = (idx_generator | dir);
658 idx_generator += 8;
659 } else {
660 idx = index;
661 index = 0;
662 }
663
664 if (idx == 0)
665 idx = 8;
666 list = net->xfrm.policy_byidx + idx_hash(net, idx);
667 found = 0;
668 hlist_for_each_entry(p, list, byidx) {
669 if (p->index == idx) {
670 found = 1;
671 break;
672 }
673 }
674 if (!found)
675 return idx;
676 }
677 }
678
679 static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
680 {
681 u32 *p1 = (u32 *) s1;
682 u32 *p2 = (u32 *) s2;
683 int len = sizeof(struct xfrm_selector) / sizeof(u32);
684 int i;
685
686 for (i = 0; i < len; i++) {
687 if (p1[i] != p2[i])
688 return 1;
689 }
690
691 return 0;
692 }
693
694 static void xfrm_policy_requeue(struct xfrm_policy *old,
695 struct xfrm_policy *new)
696 {
697 struct xfrm_policy_queue *pq = &old->polq;
698 struct sk_buff_head list;
699
700 if (skb_queue_empty(&pq->hold_queue))
701 return;
702
703 __skb_queue_head_init(&list);
704
705 spin_lock_bh(&pq->hold_queue.lock);
706 skb_queue_splice_init(&pq->hold_queue, &list);
707 if (del_timer(&pq->hold_timer))
708 xfrm_pol_put(old);
709 spin_unlock_bh(&pq->hold_queue.lock);
710
711 pq = &new->polq;
712
713 spin_lock_bh(&pq->hold_queue.lock);
714 skb_queue_splice(&list, &pq->hold_queue);
715 pq->timeout = XFRM_QUEUE_TMO_MIN;
716 if (!mod_timer(&pq->hold_timer, jiffies))
717 xfrm_pol_hold(new);
718 spin_unlock_bh(&pq->hold_queue.lock);
719 }
720
721 static bool xfrm_policy_mark_match(struct xfrm_policy *policy,
722 struct xfrm_policy *pol)
723 {
724 u32 mark = policy->mark.v & policy->mark.m;
725
726 if (policy->mark.v == pol->mark.v && policy->mark.m == pol->mark.m)
727 return true;
728
729 if ((mark & pol->mark.m) == pol->mark.v &&
730 policy->priority == pol->priority)
731 return true;
732
733 return false;
734 }
735
736 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
737 {
738 struct net *net = xp_net(policy);
739 struct xfrm_policy *pol;
740 struct xfrm_policy *delpol;
741 struct hlist_head *chain;
742 struct hlist_node *newpos;
743
744 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
745 chain = policy_hash_bysel(net, &policy->selector, policy->family, dir);
746 delpol = NULL;
747 newpos = NULL;
748 hlist_for_each_entry(pol, chain, bydst) {
749 if (pol->type == policy->type &&
750 !selector_cmp(&pol->selector, &policy->selector) &&
751 xfrm_policy_mark_match(policy, pol) &&
752 xfrm_sec_ctx_match(pol->security, policy->security) &&
753 !WARN_ON(delpol)) {
754 if (excl) {
755 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
756 return -EEXIST;
757 }
758 delpol = pol;
759 if (policy->priority > pol->priority)
760 continue;
761 } else if (policy->priority >= pol->priority) {
762 newpos = &pol->bydst;
763 continue;
764 }
765 if (delpol)
766 break;
767 }
768 if (newpos)
769 hlist_add_behind(&policy->bydst, newpos);
770 else
771 hlist_add_head(&policy->bydst, chain);
772 __xfrm_policy_link(policy, dir);
773
774 /* After previous checking, family can either be AF_INET or AF_INET6 */
775 if (policy->family == AF_INET)
776 rt_genid_bump_ipv4(net);
777 else
778 rt_genid_bump_ipv6(net);
779
780 if (delpol) {
781 xfrm_policy_requeue(delpol, policy);
782 __xfrm_policy_unlink(delpol, dir);
783 }
784 policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir, policy->index);
785 hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
786 policy->curlft.add_time = get_seconds();
787 policy->curlft.use_time = 0;
788 if (!mod_timer(&policy->timer, jiffies + HZ))
789 xfrm_pol_hold(policy);
790 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
791
792 if (delpol)
793 xfrm_policy_kill(delpol);
794 else if (xfrm_bydst_should_resize(net, dir, NULL))
795 schedule_work(&net->xfrm.policy_hash_work);
796
797 return 0;
798 }
799 EXPORT_SYMBOL(xfrm_policy_insert);
800
801 struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u8 type,
802 int dir, struct xfrm_selector *sel,
803 struct xfrm_sec_ctx *ctx, int delete,
804 int *err)
805 {
806 struct xfrm_policy *pol, *ret;
807 struct hlist_head *chain;
808
809 *err = 0;
810 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
811 chain = policy_hash_bysel(net, sel, sel->family, dir);
812 ret = NULL;
813 hlist_for_each_entry(pol, chain, bydst) {
814 if (pol->type == type &&
815 (mark & pol->mark.m) == pol->mark.v &&
816 !selector_cmp(sel, &pol->selector) &&
817 xfrm_sec_ctx_match(ctx, pol->security)) {
818 xfrm_pol_hold(pol);
819 if (delete) {
820 *err = security_xfrm_policy_delete(
821 pol->security);
822 if (*err) {
823 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
824 return pol;
825 }
826 __xfrm_policy_unlink(pol, dir);
827 }
828 ret = pol;
829 break;
830 }
831 }
832 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
833
834 if (ret && delete)
835 xfrm_policy_kill(ret);
836 return ret;
837 }
838 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
839
840 struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8 type,
841 int dir, u32 id, int delete, int *err)
842 {
843 struct xfrm_policy *pol, *ret;
844 struct hlist_head *chain;
845
846 *err = -ENOENT;
847 if (xfrm_policy_id2dir(id) != dir)
848 return NULL;
849
850 *err = 0;
851 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
852 chain = net->xfrm.policy_byidx + idx_hash(net, id);
853 ret = NULL;
854 hlist_for_each_entry(pol, chain, byidx) {
855 if (pol->type == type && pol->index == id &&
856 (mark & pol->mark.m) == pol->mark.v) {
857 xfrm_pol_hold(pol);
858 if (delete) {
859 *err = security_xfrm_policy_delete(
860 pol->security);
861 if (*err) {
862 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
863 return pol;
864 }
865 __xfrm_policy_unlink(pol, dir);
866 }
867 ret = pol;
868 break;
869 }
870 }
871 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
872
873 if (ret && delete)
874 xfrm_policy_kill(ret);
875 return ret;
876 }
877 EXPORT_SYMBOL(xfrm_policy_byid);
878
879 #ifdef CONFIG_SECURITY_NETWORK_XFRM
880 static inline int
881 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
882 {
883 int dir, err = 0;
884
885 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
886 struct xfrm_policy *pol;
887 int i;
888
889 hlist_for_each_entry(pol,
890 &net->xfrm.policy_inexact[dir], bydst) {
891 if (pol->type != type)
892 continue;
893 err = security_xfrm_policy_delete(pol->security);
894 if (err) {
895 xfrm_audit_policy_delete(pol, 0, task_valid);
896 return err;
897 }
898 }
899 for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
900 hlist_for_each_entry(pol,
901 net->xfrm.policy_bydst[dir].table + i,
902 bydst) {
903 if (pol->type != type)
904 continue;
905 err = security_xfrm_policy_delete(
906 pol->security);
907 if (err) {
908 xfrm_audit_policy_delete(pol, 0,
909 task_valid);
910 return err;
911 }
912 }
913 }
914 }
915 return err;
916 }
917 #else
918 static inline int
919 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
920 {
921 return 0;
922 }
923 #endif
924
925 int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
926 {
927 int dir, err = 0, cnt = 0;
928
929 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
930
931 err = xfrm_policy_flush_secctx_check(net, type, task_valid);
932 if (err)
933 goto out;
934
935 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
936 struct xfrm_policy *pol;
937 int i;
938
939 again1:
940 hlist_for_each_entry(pol,
941 &net->xfrm.policy_inexact[dir], bydst) {
942 if (pol->type != type)
943 continue;
944 __xfrm_policy_unlink(pol, dir);
945 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
946 cnt++;
947
948 xfrm_audit_policy_delete(pol, 1, task_valid);
949
950 xfrm_policy_kill(pol);
951
952 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
953 goto again1;
954 }
955
956 for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
957 again2:
958 hlist_for_each_entry(pol,
959 net->xfrm.policy_bydst[dir].table + i,
960 bydst) {
961 if (pol->type != type)
962 continue;
963 __xfrm_policy_unlink(pol, dir);
964 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
965 cnt++;
966
967 xfrm_audit_policy_delete(pol, 1, task_valid);
968 xfrm_policy_kill(pol);
969
970 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
971 goto again2;
972 }
973 }
974
975 }
976 if (!cnt)
977 err = -ESRCH;
978 out:
979 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
980 return err;
981 }
982 EXPORT_SYMBOL(xfrm_policy_flush);
983
984 int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
985 int (*func)(struct xfrm_policy *, int, int, void*),
986 void *data)
987 {
988 struct xfrm_policy *pol;
989 struct xfrm_policy_walk_entry *x;
990 int error = 0;
991
992 if (walk->type >= XFRM_POLICY_TYPE_MAX &&
993 walk->type != XFRM_POLICY_TYPE_ANY)
994 return -EINVAL;
995
996 if (list_empty(&walk->walk.all) && walk->seq != 0)
997 return 0;
998
999 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1000 if (list_empty(&walk->walk.all))
1001 x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
1002 else
1003 x = list_first_entry(&walk->walk.all,
1004 struct xfrm_policy_walk_entry, all);
1005
1006 list_for_each_entry_from(x, &net->xfrm.policy_all, all) {
1007 if (x->dead)
1008 continue;
1009 pol = container_of(x, struct xfrm_policy, walk);
1010 if (walk->type != XFRM_POLICY_TYPE_ANY &&
1011 walk->type != pol->type)
1012 continue;
1013 error = func(pol, xfrm_policy_id2dir(pol->index),
1014 walk->seq, data);
1015 if (error) {
1016 list_move_tail(&walk->walk.all, &x->all);
1017 goto out;
1018 }
1019 walk->seq++;
1020 }
1021 if (walk->seq == 0) {
1022 error = -ENOENT;
1023 goto out;
1024 }
1025 list_del_init(&walk->walk.all);
1026 out:
1027 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1028 return error;
1029 }
1030 EXPORT_SYMBOL(xfrm_policy_walk);
1031
1032 void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type)
1033 {
1034 INIT_LIST_HEAD(&walk->walk.all);
1035 walk->walk.dead = 1;
1036 walk->type = type;
1037 walk->seq = 0;
1038 }
1039 EXPORT_SYMBOL(xfrm_policy_walk_init);
1040
1041 void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net)
1042 {
1043 if (list_empty(&walk->walk.all))
1044 return;
1045
1046 spin_lock_bh(&net->xfrm.xfrm_policy_lock); /*FIXME where is net? */
1047 list_del(&walk->walk.all);
1048 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1049 }
1050 EXPORT_SYMBOL(xfrm_policy_walk_done);
1051
1052 /*
1053 * Find policy to apply to this flow.
1054 *
1055 * Returns 0 if policy found, else an -errno.
1056 */
1057 static int xfrm_policy_match(const struct xfrm_policy *pol,
1058 const struct flowi *fl,
1059 u8 type, u16 family, int dir)
1060 {
1061 const struct xfrm_selector *sel = &pol->selector;
1062 int ret = -ESRCH;
1063 bool match;
1064
1065 if (pol->family != family ||
1066 (fl->flowi_mark & pol->mark.m) != pol->mark.v ||
1067 pol->type != type)
1068 return ret;
1069
1070 match = xfrm_selector_match(sel, fl, family);
1071 if (match)
1072 ret = security_xfrm_policy_lookup(pol->security, fl->flowi_secid,
1073 dir);
1074
1075 return ret;
1076 }
1077
1078 static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
1079 const struct flowi *fl,
1080 u16 family, u8 dir)
1081 {
1082 int err;
1083 struct xfrm_policy *pol, *ret;
1084 const xfrm_address_t *daddr, *saddr;
1085 struct hlist_head *chain;
1086 unsigned int sequence;
1087 u32 priority;
1088
1089 daddr = xfrm_flowi_daddr(fl, family);
1090 saddr = xfrm_flowi_saddr(fl, family);
1091 if (unlikely(!daddr || !saddr))
1092 return NULL;
1093
1094 rcu_read_lock();
1095 retry:
1096 do {
1097 sequence = read_seqcount_begin(&xfrm_policy_hash_generation);
1098 chain = policy_hash_direct(net, daddr, saddr, family, dir);
1099 } while (read_seqcount_retry(&xfrm_policy_hash_generation, sequence));
1100
1101 priority = ~0U;
1102 ret = NULL;
1103 hlist_for_each_entry_rcu(pol, chain, bydst) {
1104 err = xfrm_policy_match(pol, fl, type, family, dir);
1105 if (err) {
1106 if (err == -ESRCH)
1107 continue;
1108 else {
1109 ret = ERR_PTR(err);
1110 goto fail;
1111 }
1112 } else {
1113 ret = pol;
1114 priority = ret->priority;
1115 break;
1116 }
1117 }
1118 chain = &net->xfrm.policy_inexact[dir];
1119 hlist_for_each_entry_rcu(pol, chain, bydst) {
1120 if ((pol->priority >= priority) && ret)
1121 break;
1122
1123 err = xfrm_policy_match(pol, fl, type, family, dir);
1124 if (err) {
1125 if (err == -ESRCH)
1126 continue;
1127 else {
1128 ret = ERR_PTR(err);
1129 goto fail;
1130 }
1131 } else {
1132 ret = pol;
1133 break;
1134 }
1135 }
1136
1137 if (read_seqcount_retry(&xfrm_policy_hash_generation, sequence))
1138 goto retry;
1139
1140 if (ret && !xfrm_pol_hold_rcu(ret))
1141 goto retry;
1142 fail:
1143 rcu_read_unlock();
1144
1145 return ret;
1146 }
1147
1148 static struct xfrm_policy *
1149 xfrm_policy_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir)
1150 {
1151 #ifdef CONFIG_XFRM_SUB_POLICY
1152 struct xfrm_policy *pol;
1153
1154 pol = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_SUB, fl, family, dir);
1155 if (pol != NULL)
1156 return pol;
1157 #endif
1158 return xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, fl, family, dir);
1159 }
1160
1161 static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir,
1162 const struct flowi *fl, u16 family)
1163 {
1164 struct xfrm_policy *pol;
1165
1166 rcu_read_lock();
1167 again:
1168 pol = rcu_dereference(sk->sk_policy[dir]);
1169 if (pol != NULL) {
1170 bool match;
1171 int err = 0;
1172
1173 if (pol->family != family) {
1174 pol = NULL;
1175 goto out;
1176 }
1177
1178 match = xfrm_selector_match(&pol->selector, fl, family);
1179 if (match) {
1180 if ((sk->sk_mark & pol->mark.m) != pol->mark.v) {
1181 pol = NULL;
1182 goto out;
1183 }
1184 err = security_xfrm_policy_lookup(pol->security,
1185 fl->flowi_secid,
1186 dir);
1187 if (!err) {
1188 if (!xfrm_pol_hold_rcu(pol))
1189 goto again;
1190 } else if (err == -ESRCH) {
1191 pol = NULL;
1192 } else {
1193 pol = ERR_PTR(err);
1194 }
1195 } else
1196 pol = NULL;
1197 }
1198 out:
1199 rcu_read_unlock();
1200 return pol;
1201 }
1202
1203 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
1204 {
1205 struct net *net = xp_net(pol);
1206
1207 list_add(&pol->walk.all, &net->xfrm.policy_all);
1208 net->xfrm.policy_count[dir]++;
1209 xfrm_pol_hold(pol);
1210 }
1211
1212 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
1213 int dir)
1214 {
1215 struct net *net = xp_net(pol);
1216
1217 if (list_empty(&pol->walk.all))
1218 return NULL;
1219
1220 /* Socket policies are not hashed. */
1221 if (!hlist_unhashed(&pol->bydst)) {
1222 hlist_del_rcu(&pol->bydst);
1223 hlist_del(&pol->byidx);
1224 }
1225
1226 list_del_init(&pol->walk.all);
1227 net->xfrm.policy_count[dir]--;
1228
1229 return pol;
1230 }
1231
1232 static void xfrm_sk_policy_link(struct xfrm_policy *pol, int dir)
1233 {
1234 __xfrm_policy_link(pol, XFRM_POLICY_MAX + dir);
1235 }
1236
1237 static void xfrm_sk_policy_unlink(struct xfrm_policy *pol, int dir)
1238 {
1239 __xfrm_policy_unlink(pol, XFRM_POLICY_MAX + dir);
1240 }
1241
1242 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
1243 {
1244 struct net *net = xp_net(pol);
1245
1246 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1247 pol = __xfrm_policy_unlink(pol, dir);
1248 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1249 if (pol) {
1250 xfrm_policy_kill(pol);
1251 return 0;
1252 }
1253 return -ENOENT;
1254 }
1255 EXPORT_SYMBOL(xfrm_policy_delete);
1256
1257 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
1258 {
1259 struct net *net = sock_net(sk);
1260 struct xfrm_policy *old_pol;
1261
1262 #ifdef CONFIG_XFRM_SUB_POLICY
1263 if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
1264 return -EINVAL;
1265 #endif
1266
1267 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1268 old_pol = rcu_dereference_protected(sk->sk_policy[dir],
1269 lockdep_is_held(&net->xfrm.xfrm_policy_lock));
1270 if (pol) {
1271 pol->curlft.add_time = get_seconds();
1272 pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir, 0);
1273 xfrm_sk_policy_link(pol, dir);
1274 }
1275 rcu_assign_pointer(sk->sk_policy[dir], pol);
1276 if (old_pol) {
1277 if (pol)
1278 xfrm_policy_requeue(old_pol, pol);
1279
1280 /* Unlinking succeeds always. This is the only function
1281 * allowed to delete or replace socket policy.
1282 */
1283 xfrm_sk_policy_unlink(old_pol, dir);
1284 }
1285 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1286
1287 if (old_pol) {
1288 xfrm_policy_kill(old_pol);
1289 }
1290 return 0;
1291 }
1292
1293 static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
1294 {
1295 struct xfrm_policy *newp = xfrm_policy_alloc(xp_net(old), GFP_ATOMIC);
1296 struct net *net = xp_net(old);
1297
1298 if (newp) {
1299 newp->selector = old->selector;
1300 if (security_xfrm_policy_clone(old->security,
1301 &newp->security)) {
1302 kfree(newp);
1303 return NULL; /* ENOMEM */
1304 }
1305 newp->lft = old->lft;
1306 newp->curlft = old->curlft;
1307 newp->mark = old->mark;
1308 newp->action = old->action;
1309 newp->flags = old->flags;
1310 newp->xfrm_nr = old->xfrm_nr;
1311 newp->index = old->index;
1312 newp->type = old->type;
1313 newp->family = old->family;
1314 memcpy(newp->xfrm_vec, old->xfrm_vec,
1315 newp->xfrm_nr*sizeof(struct xfrm_tmpl));
1316 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1317 xfrm_sk_policy_link(newp, dir);
1318 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1319 xfrm_pol_put(newp);
1320 }
1321 return newp;
1322 }
1323
1324 int __xfrm_sk_clone_policy(struct sock *sk, const struct sock *osk)
1325 {
1326 const struct xfrm_policy *p;
1327 struct xfrm_policy *np;
1328 int i, ret = 0;
1329
1330 rcu_read_lock();
1331 for (i = 0; i < 2; i++) {
1332 p = rcu_dereference(osk->sk_policy[i]);
1333 if (p) {
1334 np = clone_policy(p, i);
1335 if (unlikely(!np)) {
1336 ret = -ENOMEM;
1337 break;
1338 }
1339 rcu_assign_pointer(sk->sk_policy[i], np);
1340 }
1341 }
1342 rcu_read_unlock();
1343 return ret;
1344 }
1345
1346 static int
1347 xfrm_get_saddr(struct net *net, int oif, xfrm_address_t *local,
1348 xfrm_address_t *remote, unsigned short family, u32 mark)
1349 {
1350 int err;
1351 const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1352
1353 if (unlikely(afinfo == NULL))
1354 return -EINVAL;
1355 err = afinfo->get_saddr(net, oif, local, remote, mark);
1356 rcu_read_unlock();
1357 return err;
1358 }
1359
1360 /* Resolve list of templates for the flow, given policy. */
1361
1362 static int
1363 xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
1364 struct xfrm_state **xfrm, unsigned short family)
1365 {
1366 struct net *net = xp_net(policy);
1367 int nx;
1368 int i, error;
1369 xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
1370 xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
1371 xfrm_address_t tmp;
1372
1373 for (nx = 0, i = 0; i < policy->xfrm_nr; i++) {
1374 struct xfrm_state *x;
1375 xfrm_address_t *remote = daddr;
1376 xfrm_address_t *local = saddr;
1377 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
1378
1379 if (tmpl->mode == XFRM_MODE_TUNNEL ||
1380 tmpl->mode == XFRM_MODE_BEET) {
1381 remote = &tmpl->id.daddr;
1382 local = &tmpl->saddr;
1383 if (xfrm_addr_any(local, tmpl->encap_family)) {
1384 error = xfrm_get_saddr(net, fl->flowi_oif,
1385 &tmp, remote,
1386 tmpl->encap_family, 0);
1387 if (error)
1388 goto fail;
1389 local = &tmp;
1390 }
1391 }
1392
1393 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
1394
1395 if (x && x->km.state == XFRM_STATE_VALID) {
1396 xfrm[nx++] = x;
1397 daddr = remote;
1398 saddr = local;
1399 continue;
1400 }
1401 if (x) {
1402 error = (x->km.state == XFRM_STATE_ERROR ?
1403 -EINVAL : -EAGAIN);
1404 xfrm_state_put(x);
1405 } else if (error == -ESRCH) {
1406 error = -EAGAIN;
1407 }
1408
1409 if (!tmpl->optional)
1410 goto fail;
1411 }
1412 return nx;
1413
1414 fail:
1415 for (nx--; nx >= 0; nx--)
1416 xfrm_state_put(xfrm[nx]);
1417 return error;
1418 }
1419
1420 static int
1421 xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, const struct flowi *fl,
1422 struct xfrm_state **xfrm, unsigned short family)
1423 {
1424 struct xfrm_state *tp[XFRM_MAX_DEPTH];
1425 struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
1426 int cnx = 0;
1427 int error;
1428 int ret;
1429 int i;
1430
1431 for (i = 0; i < npols; i++) {
1432 if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
1433 error = -ENOBUFS;
1434 goto fail;
1435 }
1436
1437 ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
1438 if (ret < 0) {
1439 error = ret;
1440 goto fail;
1441 } else
1442 cnx += ret;
1443 }
1444
1445 /* found states are sorted for outbound processing */
1446 if (npols > 1)
1447 xfrm_state_sort(xfrm, tpp, cnx, family);
1448
1449 return cnx;
1450
1451 fail:
1452 for (cnx--; cnx >= 0; cnx--)
1453 xfrm_state_put(tpp[cnx]);
1454 return error;
1455
1456 }
1457
1458 static int xfrm_get_tos(const struct flowi *fl, int family)
1459 {
1460 const struct xfrm_policy_afinfo *afinfo;
1461 int tos;
1462
1463 afinfo = xfrm_policy_get_afinfo(family);
1464 if (!afinfo)
1465 return 0;
1466
1467 tos = afinfo->get_tos(fl);
1468
1469 rcu_read_unlock();
1470
1471 return tos;
1472 }
1473
1474 static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
1475 {
1476 const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1477 struct dst_ops *dst_ops;
1478 struct xfrm_dst *xdst;
1479
1480 if (!afinfo)
1481 return ERR_PTR(-EINVAL);
1482
1483 switch (family) {
1484 case AF_INET:
1485 dst_ops = &net->xfrm.xfrm4_dst_ops;
1486 break;
1487 #if IS_ENABLED(CONFIG_IPV6)
1488 case AF_INET6:
1489 dst_ops = &net->xfrm.xfrm6_dst_ops;
1490 break;
1491 #endif
1492 default:
1493 BUG();
1494 }
1495 xdst = dst_alloc(dst_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
1496
1497 if (likely(xdst)) {
1498 struct dst_entry *dst = &xdst->u.dst;
1499
1500 memset(dst + 1, 0, sizeof(*xdst) - sizeof(*dst));
1501 } else
1502 xdst = ERR_PTR(-ENOBUFS);
1503
1504 rcu_read_unlock();
1505
1506 return xdst;
1507 }
1508
1509 static inline int xfrm_init_path(struct xfrm_dst *path, struct dst_entry *dst,
1510 int nfheader_len)
1511 {
1512 const struct xfrm_policy_afinfo *afinfo =
1513 xfrm_policy_get_afinfo(dst->ops->family);
1514 int err;
1515
1516 if (!afinfo)
1517 return -EINVAL;
1518
1519 err = afinfo->init_path(path, dst, nfheader_len);
1520
1521 rcu_read_unlock();
1522
1523 return err;
1524 }
1525
1526 static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
1527 const struct flowi *fl)
1528 {
1529 const struct xfrm_policy_afinfo *afinfo =
1530 xfrm_policy_get_afinfo(xdst->u.dst.ops->family);
1531 int err;
1532
1533 if (!afinfo)
1534 return -EINVAL;
1535
1536 err = afinfo->fill_dst(xdst, dev, fl);
1537
1538 rcu_read_unlock();
1539
1540 return err;
1541 }
1542
1543
1544 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
1545 * all the metrics... Shortly, bundle a bundle.
1546 */
1547
1548 static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
1549 struct xfrm_state **xfrm,
1550 struct xfrm_dst **bundle,
1551 int nx,
1552 const struct flowi *fl,
1553 struct dst_entry *dst)
1554 {
1555 struct net *net = xp_net(policy);
1556 unsigned long now = jiffies;
1557 struct net_device *dev;
1558 struct xfrm_mode *inner_mode;
1559 struct xfrm_dst *xdst_prev = NULL;
1560 struct xfrm_dst *xdst0 = NULL;
1561 int i = 0;
1562 int err;
1563 int header_len = 0;
1564 int nfheader_len = 0;
1565 int trailer_len = 0;
1566 int tos;
1567 int family = policy->selector.family;
1568 xfrm_address_t saddr, daddr;
1569
1570 xfrm_flowi_addr_get(fl, &saddr, &daddr, family);
1571
1572 tos = xfrm_get_tos(fl, family);
1573
1574 dst_hold(dst);
1575
1576 for (; i < nx; i++) {
1577 struct xfrm_dst *xdst = xfrm_alloc_dst(net, family);
1578 struct dst_entry *dst1 = &xdst->u.dst;
1579
1580 err = PTR_ERR(xdst);
1581 if (IS_ERR(xdst)) {
1582 dst_release(dst);
1583 goto put_states;
1584 }
1585
1586 bundle[i] = xdst;
1587 if (!xdst_prev)
1588 xdst0 = xdst;
1589 else
1590 /* Ref count is taken during xfrm_alloc_dst()
1591 * No need to do dst_clone() on dst1
1592 */
1593 xfrm_dst_set_child(xdst_prev, &xdst->u.dst);
1594
1595 if (xfrm[i]->sel.family == AF_UNSPEC) {
1596 inner_mode = xfrm_ip2inner_mode(xfrm[i],
1597 xfrm_af2proto(family));
1598 if (!inner_mode) {
1599 err = -EAFNOSUPPORT;
1600 dst_release(dst);
1601 goto put_states;
1602 }
1603 } else
1604 inner_mode = xfrm[i]->inner_mode;
1605
1606 xdst->route = dst;
1607 dst_copy_metrics(dst1, dst);
1608
1609 if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
1610 family = xfrm[i]->props.family;
1611 dst = xfrm_dst_lookup(xfrm[i], tos, fl->flowi_oif,
1612 &saddr, &daddr, family,
1613 xfrm[i]->props.output_mark);
1614 err = PTR_ERR(dst);
1615 if (IS_ERR(dst))
1616 goto put_states;
1617 } else
1618 dst_hold(dst);
1619
1620 dst1->xfrm = xfrm[i];
1621 xdst->xfrm_genid = xfrm[i]->genid;
1622
1623 dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
1624 dst1->flags |= DST_HOST;
1625 dst1->lastuse = now;
1626
1627 dst1->input = dst_discard;
1628 dst1->output = inner_mode->afinfo->output;
1629
1630 xdst_prev = xdst;
1631
1632 header_len += xfrm[i]->props.header_len;
1633 if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
1634 nfheader_len += xfrm[i]->props.header_len;
1635 trailer_len += xfrm[i]->props.trailer_len;
1636 }
1637
1638 xfrm_dst_set_child(xdst_prev, dst);
1639 xdst0->path = dst;
1640
1641 err = -ENODEV;
1642 dev = dst->dev;
1643 if (!dev)
1644 goto free_dst;
1645
1646 xfrm_init_path(xdst0, dst, nfheader_len);
1647 xfrm_init_pmtu(bundle, nx);
1648
1649 for (xdst_prev = xdst0; xdst_prev != (struct xfrm_dst *)dst;
1650 xdst_prev = (struct xfrm_dst *) xfrm_dst_child(&xdst_prev->u.dst)) {
1651 err = xfrm_fill_dst(xdst_prev, dev, fl);
1652 if (err)
1653 goto free_dst;
1654
1655 xdst_prev->u.dst.header_len = header_len;
1656 xdst_prev->u.dst.trailer_len = trailer_len;
1657 header_len -= xdst_prev->u.dst.xfrm->props.header_len;
1658 trailer_len -= xdst_prev->u.dst.xfrm->props.trailer_len;
1659 }
1660
1661 out:
1662 return &xdst0->u.dst;
1663
1664 put_states:
1665 for (; i < nx; i++)
1666 xfrm_state_put(xfrm[i]);
1667 free_dst:
1668 if (xdst0)
1669 dst_release_immediate(&xdst0->u.dst);
1670 xdst0 = ERR_PTR(err);
1671 goto out;
1672 }
1673
1674 static int xfrm_expand_policies(const struct flowi *fl, u16 family,
1675 struct xfrm_policy **pols,
1676 int *num_pols, int *num_xfrms)
1677 {
1678 int i;
1679
1680 if (*num_pols == 0 || !pols[0]) {
1681 *num_pols = 0;
1682 *num_xfrms = 0;
1683 return 0;
1684 }
1685 if (IS_ERR(pols[0]))
1686 return PTR_ERR(pols[0]);
1687
1688 *num_xfrms = pols[0]->xfrm_nr;
1689
1690 #ifdef CONFIG_XFRM_SUB_POLICY
1691 if (pols[0] && pols[0]->action == XFRM_POLICY_ALLOW &&
1692 pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1693 pols[1] = xfrm_policy_lookup_bytype(xp_net(pols[0]),
1694 XFRM_POLICY_TYPE_MAIN,
1695 fl, family,
1696 XFRM_POLICY_OUT);
1697 if (pols[1]) {
1698 if (IS_ERR(pols[1])) {
1699 xfrm_pols_put(pols, *num_pols);
1700 return PTR_ERR(pols[1]);
1701 }
1702 (*num_pols)++;
1703 (*num_xfrms) += pols[1]->xfrm_nr;
1704 }
1705 }
1706 #endif
1707 for (i = 0; i < *num_pols; i++) {
1708 if (pols[i]->action != XFRM_POLICY_ALLOW) {
1709 *num_xfrms = -1;
1710 break;
1711 }
1712 }
1713
1714 return 0;
1715
1716 }
1717
1718 static void xfrm_last_dst_update(struct xfrm_dst *xdst, struct xfrm_dst *old)
1719 {
1720 this_cpu_write(xfrm_last_dst, xdst);
1721 if (old)
1722 dst_release(&old->u.dst);
1723 }
1724
1725 static void __xfrm_pcpu_work_fn(void)
1726 {
1727 struct xfrm_dst *old;
1728
1729 old = this_cpu_read(xfrm_last_dst);
1730 if (old && !xfrm_bundle_ok(old))
1731 xfrm_last_dst_update(NULL, old);
1732 }
1733
1734 static void xfrm_pcpu_work_fn(struct work_struct *work)
1735 {
1736 local_bh_disable();
1737 rcu_read_lock();
1738 __xfrm_pcpu_work_fn();
1739 rcu_read_unlock();
1740 local_bh_enable();
1741 }
1742
1743 void xfrm_policy_cache_flush(void)
1744 {
1745 struct xfrm_dst *old;
1746 bool found = 0;
1747 int cpu;
1748
1749 might_sleep();
1750
1751 local_bh_disable();
1752 rcu_read_lock();
1753 for_each_possible_cpu(cpu) {
1754 old = per_cpu(xfrm_last_dst, cpu);
1755 if (old && !xfrm_bundle_ok(old)) {
1756 if (smp_processor_id() == cpu) {
1757 __xfrm_pcpu_work_fn();
1758 continue;
1759 }
1760 found = true;
1761 break;
1762 }
1763 }
1764
1765 rcu_read_unlock();
1766 local_bh_enable();
1767
1768 if (!found)
1769 return;
1770
1771 get_online_cpus();
1772
1773 for_each_possible_cpu(cpu) {
1774 bool bundle_release;
1775
1776 rcu_read_lock();
1777 old = per_cpu(xfrm_last_dst, cpu);
1778 bundle_release = old && !xfrm_bundle_ok(old);
1779 rcu_read_unlock();
1780
1781 if (!bundle_release)
1782 continue;
1783
1784 if (cpu_online(cpu)) {
1785 schedule_work_on(cpu, &xfrm_pcpu_work[cpu]);
1786 continue;
1787 }
1788
1789 rcu_read_lock();
1790 old = per_cpu(xfrm_last_dst, cpu);
1791 if (old && !xfrm_bundle_ok(old)) {
1792 per_cpu(xfrm_last_dst, cpu) = NULL;
1793 dst_release(&old->u.dst);
1794 }
1795 rcu_read_unlock();
1796 }
1797
1798 put_online_cpus();
1799 }
1800
1801 static bool xfrm_xdst_can_reuse(struct xfrm_dst *xdst,
1802 struct xfrm_state * const xfrm[],
1803 int num)
1804 {
1805 const struct dst_entry *dst = &xdst->u.dst;
1806 int i;
1807
1808 if (xdst->num_xfrms != num)
1809 return false;
1810
1811 for (i = 0; i < num; i++) {
1812 if (!dst || dst->xfrm != xfrm[i])
1813 return false;
1814 dst = xfrm_dst_child(dst);
1815 }
1816
1817 return xfrm_bundle_ok(xdst);
1818 }
1819
1820 static struct xfrm_dst *
1821 xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
1822 const struct flowi *fl, u16 family,
1823 struct dst_entry *dst_orig)
1824 {
1825 struct net *net = xp_net(pols[0]);
1826 struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
1827 struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
1828 struct xfrm_dst *xdst, *old;
1829 struct dst_entry *dst;
1830 int err;
1831
1832 /* Try to instantiate a bundle */
1833 err = xfrm_tmpl_resolve(pols, num_pols, fl, xfrm, family);
1834 if (err <= 0) {
1835 if (err != 0 && err != -EAGAIN)
1836 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
1837 return ERR_PTR(err);
1838 }
1839
1840 xdst = this_cpu_read(xfrm_last_dst);
1841 if (xdst &&
1842 xdst->u.dst.dev == dst_orig->dev &&
1843 xdst->num_pols == num_pols &&
1844 memcmp(xdst->pols, pols,
1845 sizeof(struct xfrm_policy *) * num_pols) == 0 &&
1846 xfrm_xdst_can_reuse(xdst, xfrm, err)) {
1847 dst_hold(&xdst->u.dst);
1848 xfrm_pols_put(pols, num_pols);
1849 while (err > 0)
1850 xfrm_state_put(xfrm[--err]);
1851 return xdst;
1852 }
1853
1854 old = xdst;
1855
1856 dst = xfrm_bundle_create(pols[0], xfrm, bundle, err, fl, dst_orig);
1857 if (IS_ERR(dst)) {
1858 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR);
1859 return ERR_CAST(dst);
1860 }
1861
1862 xdst = (struct xfrm_dst *)dst;
1863 xdst->num_xfrms = err;
1864 xdst->num_pols = num_pols;
1865 memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
1866 xdst->policy_genid = atomic_read(&pols[0]->genid);
1867
1868 atomic_set(&xdst->u.dst.__refcnt, 2);
1869 xfrm_last_dst_update(xdst, old);
1870
1871 return xdst;
1872 }
1873
1874 static void xfrm_policy_queue_process(struct timer_list *t)
1875 {
1876 struct sk_buff *skb;
1877 struct sock *sk;
1878 struct dst_entry *dst;
1879 struct xfrm_policy *pol = from_timer(pol, t, polq.hold_timer);
1880 struct net *net = xp_net(pol);
1881 struct xfrm_policy_queue *pq = &pol->polq;
1882 struct flowi fl;
1883 struct sk_buff_head list;
1884
1885 spin_lock(&pq->hold_queue.lock);
1886 skb = skb_peek(&pq->hold_queue);
1887 if (!skb) {
1888 spin_unlock(&pq->hold_queue.lock);
1889 goto out;
1890 }
1891 dst = skb_dst(skb);
1892 sk = skb->sk;
1893 xfrm_decode_session(skb, &fl, dst->ops->family);
1894 spin_unlock(&pq->hold_queue.lock);
1895
1896 dst_hold(xfrm_dst_path(dst));
1897 dst = xfrm_lookup(net, xfrm_dst_path(dst), &fl, sk, XFRM_LOOKUP_QUEUE);
1898 if (IS_ERR(dst))
1899 goto purge_queue;
1900
1901 if (dst->flags & DST_XFRM_QUEUE) {
1902 dst_release(dst);
1903
1904 if (pq->timeout >= XFRM_QUEUE_TMO_MAX)
1905 goto purge_queue;
1906
1907 pq->timeout = pq->timeout << 1;
1908 if (!mod_timer(&pq->hold_timer, jiffies + pq->timeout))
1909 xfrm_pol_hold(pol);
1910 goto out;
1911 }
1912
1913 dst_release(dst);
1914
1915 __skb_queue_head_init(&list);
1916
1917 spin_lock(&pq->hold_queue.lock);
1918 pq->timeout = 0;
1919 skb_queue_splice_init(&pq->hold_queue, &list);
1920 spin_unlock(&pq->hold_queue.lock);
1921
1922 while (!skb_queue_empty(&list)) {
1923 skb = __skb_dequeue(&list);
1924
1925 xfrm_decode_session(skb, &fl, skb_dst(skb)->ops->family);
1926 dst_hold(xfrm_dst_path(skb_dst(skb)));
1927 dst = xfrm_lookup(net, xfrm_dst_path(skb_dst(skb)), &fl, skb->sk, 0);
1928 if (IS_ERR(dst)) {
1929 kfree_skb(skb);
1930 continue;
1931 }
1932
1933 nf_reset(skb);
1934 skb_dst_drop(skb);
1935 skb_dst_set(skb, dst);
1936
1937 dst_output(net, skb->sk, skb);
1938 }
1939
1940 out:
1941 xfrm_pol_put(pol);
1942 return;
1943
1944 purge_queue:
1945 pq->timeout = 0;
1946 skb_queue_purge(&pq->hold_queue);
1947 xfrm_pol_put(pol);
1948 }
1949
1950 static int xdst_queue_output(struct net *net, struct sock *sk, struct sk_buff *skb)
1951 {
1952 unsigned long sched_next;
1953 struct dst_entry *dst = skb_dst(skb);
1954 struct xfrm_dst *xdst = (struct xfrm_dst *) dst;
1955 struct xfrm_policy *pol = xdst->pols[0];
1956 struct xfrm_policy_queue *pq = &pol->polq;
1957
1958 if (unlikely(skb_fclone_busy(sk, skb))) {
1959 kfree_skb(skb);
1960 return 0;
1961 }
1962
1963 if (pq->hold_queue.qlen > XFRM_MAX_QUEUE_LEN) {
1964 kfree_skb(skb);
1965 return -EAGAIN;
1966 }
1967
1968 skb_dst_force(skb);
1969
1970 spin_lock_bh(&pq->hold_queue.lock);
1971
1972 if (!pq->timeout)
1973 pq->timeout = XFRM_QUEUE_TMO_MIN;
1974
1975 sched_next = jiffies + pq->timeout;
1976
1977 if (del_timer(&pq->hold_timer)) {
1978 if (time_before(pq->hold_timer.expires, sched_next))
1979 sched_next = pq->hold_timer.expires;
1980 xfrm_pol_put(pol);
1981 }
1982
1983 __skb_queue_tail(&pq->hold_queue, skb);
1984 if (!mod_timer(&pq->hold_timer, sched_next))
1985 xfrm_pol_hold(pol);
1986
1987 spin_unlock_bh(&pq->hold_queue.lock);
1988
1989 return 0;
1990 }
1991
1992 static struct xfrm_dst *xfrm_create_dummy_bundle(struct net *net,
1993 struct xfrm_flo *xflo,
1994 const struct flowi *fl,
1995 int num_xfrms,
1996 u16 family)
1997 {
1998 int err;
1999 struct net_device *dev;
2000 struct dst_entry *dst;
2001 struct dst_entry *dst1;
2002 struct xfrm_dst *xdst;
2003
2004 xdst = xfrm_alloc_dst(net, family);
2005 if (IS_ERR(xdst))
2006 return xdst;
2007
2008 if (!(xflo->flags & XFRM_LOOKUP_QUEUE) ||
2009 net->xfrm.sysctl_larval_drop ||
2010 num_xfrms <= 0)
2011 return xdst;
2012
2013 dst = xflo->dst_orig;
2014 dst1 = &xdst->u.dst;
2015 dst_hold(dst);
2016 xdst->route = dst;
2017
2018 dst_copy_metrics(dst1, dst);
2019
2020 dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
2021 dst1->flags |= DST_HOST | DST_XFRM_QUEUE;
2022 dst1->lastuse = jiffies;
2023
2024 dst1->input = dst_discard;
2025 dst1->output = xdst_queue_output;
2026
2027 dst_hold(dst);
2028 xfrm_dst_set_child(xdst, dst);
2029 xdst->path = dst;
2030
2031 xfrm_init_path((struct xfrm_dst *)dst1, dst, 0);
2032
2033 err = -ENODEV;
2034 dev = dst->dev;
2035 if (!dev)
2036 goto free_dst;
2037
2038 err = xfrm_fill_dst(xdst, dev, fl);
2039 if (err)
2040 goto free_dst;
2041
2042 out:
2043 return xdst;
2044
2045 free_dst:
2046 dst_release(dst1);
2047 xdst = ERR_PTR(err);
2048 goto out;
2049 }
2050
2051 static struct xfrm_dst *
2052 xfrm_bundle_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir, struct xfrm_flo *xflo)
2053 {
2054 struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2055 int num_pols = 0, num_xfrms = 0, err;
2056 struct xfrm_dst *xdst;
2057
2058 /* Resolve policies to use if we couldn't get them from
2059 * previous cache entry */
2060 num_pols = 1;
2061 pols[0] = xfrm_policy_lookup(net, fl, family, dir);
2062 err = xfrm_expand_policies(fl, family, pols,
2063 &num_pols, &num_xfrms);
2064 if (err < 0)
2065 goto inc_error;
2066 if (num_pols == 0)
2067 return NULL;
2068 if (num_xfrms <= 0)
2069 goto make_dummy_bundle;
2070
2071 local_bh_disable();
2072 xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family,
2073 xflo->dst_orig);
2074 local_bh_enable();
2075
2076 if (IS_ERR(xdst)) {
2077 err = PTR_ERR(xdst);
2078 if (err != -EAGAIN)
2079 goto error;
2080 goto make_dummy_bundle;
2081 } else if (xdst == NULL) {
2082 num_xfrms = 0;
2083 goto make_dummy_bundle;
2084 }
2085
2086 return xdst;
2087
2088 make_dummy_bundle:
2089 /* We found policies, but there's no bundles to instantiate:
2090 * either because the policy blocks, has no transformations or
2091 * we could not build template (no xfrm_states).*/
2092 xdst = xfrm_create_dummy_bundle(net, xflo, fl, num_xfrms, family);
2093 if (IS_ERR(xdst)) {
2094 xfrm_pols_put(pols, num_pols);
2095 return ERR_CAST(xdst);
2096 }
2097 xdst->num_pols = num_pols;
2098 xdst->num_xfrms = num_xfrms;
2099 memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
2100
2101 return xdst;
2102
2103 inc_error:
2104 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
2105 error:
2106 xfrm_pols_put(pols, num_pols);
2107 return ERR_PTR(err);
2108 }
2109
2110 static struct dst_entry *make_blackhole(struct net *net, u16 family,
2111 struct dst_entry *dst_orig)
2112 {
2113 const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2114 struct dst_entry *ret;
2115
2116 if (!afinfo) {
2117 dst_release(dst_orig);
2118 return ERR_PTR(-EINVAL);
2119 } else {
2120 ret = afinfo->blackhole_route(net, dst_orig);
2121 }
2122 rcu_read_unlock();
2123
2124 return ret;
2125 }
2126
2127 /* Main function: finds/creates a bundle for given flow.
2128 *
2129 * At the moment we eat a raw IP route. Mostly to speed up lookups
2130 * on interfaces with disabled IPsec.
2131 */
2132 struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
2133 const struct flowi *fl,
2134 const struct sock *sk, int flags)
2135 {
2136 struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2137 struct xfrm_dst *xdst;
2138 struct dst_entry *dst, *route;
2139 u16 family = dst_orig->ops->family;
2140 u8 dir = XFRM_POLICY_OUT;
2141 int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
2142
2143 dst = NULL;
2144 xdst = NULL;
2145 route = NULL;
2146
2147 sk = sk_const_to_full_sk(sk);
2148 if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
2149 num_pols = 1;
2150 pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, family);
2151 err = xfrm_expand_policies(fl, family, pols,
2152 &num_pols, &num_xfrms);
2153 if (err < 0)
2154 goto dropdst;
2155
2156 if (num_pols) {
2157 if (num_xfrms <= 0) {
2158 drop_pols = num_pols;
2159 goto no_transform;
2160 }
2161
2162 local_bh_disable();
2163 xdst = xfrm_resolve_and_create_bundle(
2164 pols, num_pols, fl,
2165 family, dst_orig);
2166 local_bh_enable();
2167
2168 if (IS_ERR(xdst)) {
2169 xfrm_pols_put(pols, num_pols);
2170 err = PTR_ERR(xdst);
2171 goto dropdst;
2172 } else if (xdst == NULL) {
2173 num_xfrms = 0;
2174 drop_pols = num_pols;
2175 goto no_transform;
2176 }
2177
2178 route = xdst->route;
2179 }
2180 }
2181
2182 if (xdst == NULL) {
2183 struct xfrm_flo xflo;
2184
2185 xflo.dst_orig = dst_orig;
2186 xflo.flags = flags;
2187
2188 /* To accelerate a bit... */
2189 if ((dst_orig->flags & DST_NOXFRM) ||
2190 !net->xfrm.policy_count[XFRM_POLICY_OUT])
2191 goto nopol;
2192
2193 xdst = xfrm_bundle_lookup(net, fl, family, dir, &xflo);
2194 if (xdst == NULL)
2195 goto nopol;
2196 if (IS_ERR(xdst)) {
2197 err = PTR_ERR(xdst);
2198 goto dropdst;
2199 }
2200
2201 num_pols = xdst->num_pols;
2202 num_xfrms = xdst->num_xfrms;
2203 memcpy(pols, xdst->pols, sizeof(struct xfrm_policy *) * num_pols);
2204 route = xdst->route;
2205 }
2206
2207 dst = &xdst->u.dst;
2208 if (route == NULL && num_xfrms > 0) {
2209 /* The only case when xfrm_bundle_lookup() returns a
2210 * bundle with null route, is when the template could
2211 * not be resolved. It means policies are there, but
2212 * bundle could not be created, since we don't yet
2213 * have the xfrm_state's. We need to wait for KM to
2214 * negotiate new SA's or bail out with error.*/
2215 if (net->xfrm.sysctl_larval_drop) {
2216 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
2217 err = -EREMOTE;
2218 goto error;
2219 }
2220
2221 err = -EAGAIN;
2222
2223 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
2224 goto error;
2225 }
2226
2227 no_transform:
2228 if (num_pols == 0)
2229 goto nopol;
2230
2231 if ((flags & XFRM_LOOKUP_ICMP) &&
2232 !(pols[0]->flags & XFRM_POLICY_ICMP)) {
2233 err = -ENOENT;
2234 goto error;
2235 }
2236
2237 for (i = 0; i < num_pols; i++)
2238 pols[i]->curlft.use_time = get_seconds();
2239
2240 if (num_xfrms < 0) {
2241 /* Prohibit the flow */
2242 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLBLOCK);
2243 err = -EPERM;
2244 goto error;
2245 } else if (num_xfrms > 0) {
2246 /* Flow transformed */
2247 dst_release(dst_orig);
2248 } else {
2249 /* Flow passes untransformed */
2250 dst_release(dst);
2251 dst = dst_orig;
2252 }
2253 ok:
2254 xfrm_pols_put(pols, drop_pols);
2255 if (dst && dst->xfrm &&
2256 dst->xfrm->props.mode == XFRM_MODE_TUNNEL)
2257 dst->flags |= DST_XFRM_TUNNEL;
2258 return dst;
2259
2260 nopol:
2261 if (!(flags & XFRM_LOOKUP_ICMP)) {
2262 dst = dst_orig;
2263 goto ok;
2264 }
2265 err = -ENOENT;
2266 error:
2267 dst_release(dst);
2268 dropdst:
2269 if (!(flags & XFRM_LOOKUP_KEEP_DST_REF))
2270 dst_release(dst_orig);
2271 xfrm_pols_put(pols, drop_pols);
2272 return ERR_PTR(err);
2273 }
2274 EXPORT_SYMBOL(xfrm_lookup);
2275
2276 /* Callers of xfrm_lookup_route() must ensure a call to dst_output().
2277 * Otherwise we may send out blackholed packets.
2278 */
2279 struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
2280 const struct flowi *fl,
2281 const struct sock *sk, int flags)
2282 {
2283 struct dst_entry *dst = xfrm_lookup(net, dst_orig, fl, sk,
2284 flags | XFRM_LOOKUP_QUEUE |
2285 XFRM_LOOKUP_KEEP_DST_REF);
2286
2287 if (IS_ERR(dst) && PTR_ERR(dst) == -EREMOTE)
2288 return make_blackhole(net, dst_orig->ops->family, dst_orig);
2289
2290 return dst;
2291 }
2292 EXPORT_SYMBOL(xfrm_lookup_route);
2293
2294 static inline int
2295 xfrm_secpath_reject(int idx, struct sk_buff *skb, const struct flowi *fl)
2296 {
2297 struct xfrm_state *x;
2298
2299 if (!skb->sp || idx < 0 || idx >= skb->sp->len)
2300 return 0;
2301 x = skb->sp->xvec[idx];
2302 if (!x->type->reject)
2303 return 0;
2304 return x->type->reject(x, skb, fl);
2305 }
2306
2307 /* When skb is transformed back to its "native" form, we have to
2308 * check policy restrictions. At the moment we make this in maximally
2309 * stupid way. Shame on me. :-) Of course, connected sockets must
2310 * have policy cached at them.
2311 */
2312
2313 static inline int
2314 xfrm_state_ok(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x,
2315 unsigned short family)
2316 {
2317 if (xfrm_state_kern(x))
2318 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
2319 return x->id.proto == tmpl->id.proto &&
2320 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
2321 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
2322 x->props.mode == tmpl->mode &&
2323 (tmpl->allalgs || (tmpl->aalgos & (1<<x->props.aalgo)) ||
2324 !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
2325 !(x->props.mode != XFRM_MODE_TRANSPORT &&
2326 xfrm_state_addr_cmp(tmpl, x, family));
2327 }
2328
2329 /*
2330 * 0 or more than 0 is returned when validation is succeeded (either bypass
2331 * because of optional transport mode, or next index of the mathced secpath
2332 * state with the template.
2333 * -1 is returned when no matching template is found.
2334 * Otherwise "-2 - errored_index" is returned.
2335 */
2336 static inline int
2337 xfrm_policy_ok(const struct xfrm_tmpl *tmpl, const struct sec_path *sp, int start,
2338 unsigned short family)
2339 {
2340 int idx = start;
2341
2342 if (tmpl->optional) {
2343 if (tmpl->mode == XFRM_MODE_TRANSPORT)
2344 return start;
2345 } else
2346 start = -1;
2347 for (; idx < sp->len; idx++) {
2348 if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
2349 return ++idx;
2350 if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
2351 if (start == -1)
2352 start = -2-idx;
2353 break;
2354 }
2355 }
2356 return start;
2357 }
2358
2359 int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
2360 unsigned int family, int reverse)
2361 {
2362 const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2363 int err;
2364
2365 if (unlikely(afinfo == NULL))
2366 return -EAFNOSUPPORT;
2367
2368 afinfo->decode_session(skb, fl, reverse);
2369 err = security_xfrm_decode_session(skb, &fl->flowi_secid);
2370 rcu_read_unlock();
2371 return err;
2372 }
2373 EXPORT_SYMBOL(__xfrm_decode_session);
2374
2375 static inline int secpath_has_nontransport(const struct sec_path *sp, int k, int *idxp)
2376 {
2377 for (; k < sp->len; k++) {
2378 if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
2379 *idxp = k;
2380 return 1;
2381 }
2382 }
2383
2384 return 0;
2385 }
2386
2387 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
2388 unsigned short family)
2389 {
2390 struct net *net = dev_net(skb->dev);
2391 struct xfrm_policy *pol;
2392 struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2393 int npols = 0;
2394 int xfrm_nr;
2395 int pi;
2396 int reverse;
2397 struct flowi fl;
2398 int xerr_idx = -1;
2399
2400 reverse = dir & ~XFRM_POLICY_MASK;
2401 dir &= XFRM_POLICY_MASK;
2402
2403 if (__xfrm_decode_session(skb, &fl, family, reverse) < 0) {
2404 XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
2405 return 0;
2406 }
2407
2408 nf_nat_decode_session(skb, &fl, family);
2409
2410 /* First, check used SA against their selectors. */
2411 if (skb->sp) {
2412 int i;
2413
2414 for (i = skb->sp->len-1; i >= 0; i--) {
2415 struct xfrm_state *x = skb->sp->xvec[i];
2416 if (!xfrm_selector_match(&x->sel, &fl, family)) {
2417 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
2418 return 0;
2419 }
2420 }
2421 }
2422
2423 pol = NULL;
2424 sk = sk_to_full_sk(sk);
2425 if (sk && sk->sk_policy[dir]) {
2426 pol = xfrm_sk_policy_lookup(sk, dir, &fl, family);
2427 if (IS_ERR(pol)) {
2428 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2429 return 0;
2430 }
2431 }
2432
2433 if (!pol)
2434 pol = xfrm_policy_lookup(net, &fl, family, dir);
2435
2436 if (IS_ERR(pol)) {
2437 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2438 return 0;
2439 }
2440
2441 if (!pol) {
2442 if (skb->sp && secpath_has_nontransport(skb->sp, 0, &xerr_idx)) {
2443 xfrm_secpath_reject(xerr_idx, skb, &fl);
2444 XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
2445 return 0;
2446 }
2447 return 1;
2448 }
2449
2450 pol->curlft.use_time = get_seconds();
2451
2452 pols[0] = pol;
2453 npols++;
2454 #ifdef CONFIG_XFRM_SUB_POLICY
2455 if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
2456 pols[1] = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN,
2457 &fl, family,
2458 XFRM_POLICY_IN);
2459 if (pols[1]) {
2460 if (IS_ERR(pols[1])) {
2461 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2462 return 0;
2463 }
2464 pols[1]->curlft.use_time = get_seconds();
2465 npols++;
2466 }
2467 }
2468 #endif
2469
2470 if (pol->action == XFRM_POLICY_ALLOW) {
2471 struct sec_path *sp;
2472 static struct sec_path dummy;
2473 struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
2474 struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
2475 struct xfrm_tmpl **tpp = tp;
2476 int ti = 0;
2477 int i, k;
2478
2479 if ((sp = skb->sp) == NULL)
2480 sp = &dummy;
2481
2482 for (pi = 0; pi < npols; pi++) {
2483 if (pols[pi] != pol &&
2484 pols[pi]->action != XFRM_POLICY_ALLOW) {
2485 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2486 goto reject;
2487 }
2488 if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH) {
2489 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
2490 goto reject_error;
2491 }
2492 for (i = 0; i < pols[pi]->xfrm_nr; i++)
2493 tpp[ti++] = &pols[pi]->xfrm_vec[i];
2494 }
2495 xfrm_nr = ti;
2496 if (npols > 1) {
2497 xfrm_tmpl_sort(stp, tpp, xfrm_nr, family, net);
2498 tpp = stp;
2499 }
2500
2501 /* For each tunnel xfrm, find the first matching tmpl.
2502 * For each tmpl before that, find corresponding xfrm.
2503 * Order is _important_. Later we will implement
2504 * some barriers, but at the moment barriers
2505 * are implied between each two transformations.
2506 */
2507 for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
2508 k = xfrm_policy_ok(tpp[i], sp, k, family);
2509 if (k < 0) {
2510 if (k < -1)
2511 /* "-2 - errored_index" returned */
2512 xerr_idx = -(2+k);
2513 XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2514 goto reject;
2515 }
2516 }
2517
2518 if (secpath_has_nontransport(sp, k, &xerr_idx)) {
2519 XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2520 goto reject;
2521 }
2522
2523 xfrm_pols_put(pols, npols);
2524 return 1;
2525 }
2526 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2527
2528 reject:
2529 xfrm_secpath_reject(xerr_idx, skb, &fl);
2530 reject_error:
2531 xfrm_pols_put(pols, npols);
2532 return 0;
2533 }
2534 EXPORT_SYMBOL(__xfrm_policy_check);
2535
2536 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
2537 {
2538 struct net *net = dev_net(skb->dev);
2539 struct flowi fl;
2540 struct dst_entry *dst;
2541 int res = 1;
2542
2543 if (xfrm_decode_session(skb, &fl, family) < 0) {
2544 XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
2545 return 0;
2546 }
2547
2548 skb_dst_force(skb);
2549
2550 dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, XFRM_LOOKUP_QUEUE);
2551 if (IS_ERR(dst)) {
2552 res = 0;
2553 dst = NULL;
2554 }
2555 skb_dst_set(skb, dst);
2556 return res;
2557 }
2558 EXPORT_SYMBOL(__xfrm_route_forward);
2559
2560 /* Optimize later using cookies and generation ids. */
2561
2562 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
2563 {
2564 /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
2565 * to DST_OBSOLETE_FORCE_CHK to force all XFRM destinations to
2566 * get validated by dst_ops->check on every use. We do this
2567 * because when a normal route referenced by an XFRM dst is
2568 * obsoleted we do not go looking around for all parent
2569 * referencing XFRM dsts so that we can invalidate them. It
2570 * is just too much work. Instead we make the checks here on
2571 * every use. For example:
2572 *
2573 * XFRM dst A --> IPv4 dst X
2574 *
2575 * X is the "xdst->route" of A (X is also the "dst->path" of A
2576 * in this example). If X is marked obsolete, "A" will not
2577 * notice. That's what we are validating here via the
2578 * stale_bundle() check.
2579 *
2580 * When a dst is removed from the fib tree, DST_OBSOLETE_DEAD will
2581 * be marked on it.
2582 * This will force stale_bundle() to fail on any xdst bundle with
2583 * this dst linked in it.
2584 */
2585 if (dst->obsolete < 0 && !stale_bundle(dst))
2586 return dst;
2587
2588 return NULL;
2589 }
2590
2591 static int stale_bundle(struct dst_entry *dst)
2592 {
2593 return !xfrm_bundle_ok((struct xfrm_dst *)dst);
2594 }
2595
2596 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
2597 {
2598 while ((dst = xfrm_dst_child(dst)) && dst->xfrm && dst->dev == dev) {
2599 dst->dev = dev_net(dev)->loopback_dev;
2600 dev_hold(dst->dev);
2601 dev_put(dev);
2602 }
2603 }
2604 EXPORT_SYMBOL(xfrm_dst_ifdown);
2605
2606 static void xfrm_link_failure(struct sk_buff *skb)
2607 {
2608 /* Impossible. Such dst must be popped before reaches point of failure. */
2609 }
2610
2611 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
2612 {
2613 if (dst) {
2614 if (dst->obsolete) {
2615 dst_release(dst);
2616 dst = NULL;
2617 }
2618 }
2619 return dst;
2620 }
2621
2622 static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr)
2623 {
2624 while (nr--) {
2625 struct xfrm_dst *xdst = bundle[nr];
2626 u32 pmtu, route_mtu_cached;
2627 struct dst_entry *dst;
2628
2629 dst = &xdst->u.dst;
2630 pmtu = dst_mtu(xfrm_dst_child(dst));
2631 xdst->child_mtu_cached = pmtu;
2632
2633 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
2634
2635 route_mtu_cached = dst_mtu(xdst->route);
2636 xdst->route_mtu_cached = route_mtu_cached;
2637
2638 if (pmtu > route_mtu_cached)
2639 pmtu = route_mtu_cached;
2640
2641 dst_metric_set(dst, RTAX_MTU, pmtu);
2642 }
2643 }
2644
2645 /* Check that the bundle accepts the flow and its components are
2646 * still valid.
2647 */
2648
2649 static int xfrm_bundle_ok(struct xfrm_dst *first)
2650 {
2651 struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
2652 struct dst_entry *dst = &first->u.dst;
2653 struct xfrm_dst *xdst;
2654 int start_from, nr;
2655 u32 mtu;
2656
2657 if (!dst_check(xfrm_dst_path(dst), ((struct xfrm_dst *)dst)->path_cookie) ||
2658 (dst->dev && !netif_running(dst->dev)))
2659 return 0;
2660
2661 if (dst->flags & DST_XFRM_QUEUE)
2662 return 1;
2663
2664 start_from = nr = 0;
2665 do {
2666 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2667
2668 if (dst->xfrm->km.state != XFRM_STATE_VALID)
2669 return 0;
2670 if (xdst->xfrm_genid != dst->xfrm->genid)
2671 return 0;
2672 if (xdst->num_pols > 0 &&
2673 xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
2674 return 0;
2675
2676 bundle[nr++] = xdst;
2677
2678 mtu = dst_mtu(xfrm_dst_child(dst));
2679 if (xdst->child_mtu_cached != mtu) {
2680 start_from = nr;
2681 xdst->child_mtu_cached = mtu;
2682 }
2683
2684 if (!dst_check(xdst->route, xdst->route_cookie))
2685 return 0;
2686 mtu = dst_mtu(xdst->route);
2687 if (xdst->route_mtu_cached != mtu) {
2688 start_from = nr;
2689 xdst->route_mtu_cached = mtu;
2690 }
2691
2692 dst = xfrm_dst_child(dst);
2693 } while (dst->xfrm);
2694
2695 if (likely(!start_from))
2696 return 1;
2697
2698 xdst = bundle[start_from - 1];
2699 mtu = xdst->child_mtu_cached;
2700 while (start_from--) {
2701 dst = &xdst->u.dst;
2702
2703 mtu = xfrm_state_mtu(dst->xfrm, mtu);
2704 if (mtu > xdst->route_mtu_cached)
2705 mtu = xdst->route_mtu_cached;
2706 dst_metric_set(dst, RTAX_MTU, mtu);
2707 if (!start_from)
2708 break;
2709
2710 xdst = bundle[start_from - 1];
2711 xdst->child_mtu_cached = mtu;
2712 }
2713
2714 return 1;
2715 }
2716
2717 static unsigned int xfrm_default_advmss(const struct dst_entry *dst)
2718 {
2719 return dst_metric_advmss(xfrm_dst_path(dst));
2720 }
2721
2722 static unsigned int xfrm_mtu(const struct dst_entry *dst)
2723 {
2724 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2725
2726 return mtu ? : dst_mtu(xfrm_dst_path(dst));
2727 }
2728
2729 static const void *xfrm_get_dst_nexthop(const struct dst_entry *dst,
2730 const void *daddr)
2731 {
2732 while (dst->xfrm) {
2733 const struct xfrm_state *xfrm = dst->xfrm;
2734
2735 dst = xfrm_dst_child(dst);
2736
2737 if (xfrm->props.mode == XFRM_MODE_TRANSPORT)
2738 continue;
2739 if (xfrm->type->flags & XFRM_TYPE_REMOTE_COADDR)
2740 daddr = xfrm->coaddr;
2741 else if (!(xfrm->type->flags & XFRM_TYPE_LOCAL_COADDR))
2742 daddr = &xfrm->id.daddr;
2743 }
2744 return daddr;
2745 }
2746
2747 static struct neighbour *xfrm_neigh_lookup(const struct dst_entry *dst,
2748 struct sk_buff *skb,
2749 const void *daddr)
2750 {
2751 const struct dst_entry *path = xfrm_dst_path(dst);
2752
2753 if (!skb)
2754 daddr = xfrm_get_dst_nexthop(dst, daddr);
2755 return path->ops->neigh_lookup(path, skb, daddr);
2756 }
2757
2758 static void xfrm_confirm_neigh(const struct dst_entry *dst, const void *daddr)
2759 {
2760 const struct dst_entry *path = xfrm_dst_path(dst);
2761
2762 daddr = xfrm_get_dst_nexthop(dst, daddr);
2763 path->ops->confirm_neigh(path, daddr);
2764 }
2765
2766 int xfrm_policy_register_afinfo(const struct xfrm_policy_afinfo *afinfo, int family)
2767 {
2768 int err = 0;
2769
2770 if (WARN_ON(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
2771 return -EAFNOSUPPORT;
2772
2773 spin_lock(&xfrm_policy_afinfo_lock);
2774 if (unlikely(xfrm_policy_afinfo[family] != NULL))
2775 err = -EEXIST;
2776 else {
2777 struct dst_ops *dst_ops = afinfo->dst_ops;
2778 if (likely(dst_ops->kmem_cachep == NULL))
2779 dst_ops->kmem_cachep = xfrm_dst_cache;
2780 if (likely(dst_ops->check == NULL))
2781 dst_ops->check = xfrm_dst_check;
2782 if (likely(dst_ops->default_advmss == NULL))
2783 dst_ops->default_advmss = xfrm_default_advmss;
2784 if (likely(dst_ops->mtu == NULL))
2785 dst_ops->mtu = xfrm_mtu;
2786 if (likely(dst_ops->negative_advice == NULL))
2787 dst_ops->negative_advice = xfrm_negative_advice;
2788 if (likely(dst_ops->link_failure == NULL))
2789 dst_ops->link_failure = xfrm_link_failure;
2790 if (likely(dst_ops->neigh_lookup == NULL))
2791 dst_ops->neigh_lookup = xfrm_neigh_lookup;
2792 if (likely(!dst_ops->confirm_neigh))
2793 dst_ops->confirm_neigh = xfrm_confirm_neigh;
2794 rcu_assign_pointer(xfrm_policy_afinfo[family], afinfo);
2795 }
2796 spin_unlock(&xfrm_policy_afinfo_lock);
2797
2798 return err;
2799 }
2800 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
2801
2802 void xfrm_policy_unregister_afinfo(const struct xfrm_policy_afinfo *afinfo)
2803 {
2804 struct dst_ops *dst_ops = afinfo->dst_ops;
2805 int i;
2806
2807 for (i = 0; i < ARRAY_SIZE(xfrm_policy_afinfo); i++) {
2808 if (xfrm_policy_afinfo[i] != afinfo)
2809 continue;
2810 RCU_INIT_POINTER(xfrm_policy_afinfo[i], NULL);
2811 break;
2812 }
2813
2814 synchronize_rcu();
2815
2816 dst_ops->kmem_cachep = NULL;
2817 dst_ops->check = NULL;
2818 dst_ops->negative_advice = NULL;
2819 dst_ops->link_failure = NULL;
2820 }
2821 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
2822
2823 #ifdef CONFIG_XFRM_STATISTICS
2824 static int __net_init xfrm_statistics_init(struct net *net)
2825 {
2826 int rv;
2827 net->mib.xfrm_statistics = alloc_percpu(struct linux_xfrm_mib);
2828 if (!net->mib.xfrm_statistics)
2829 return -ENOMEM;
2830 rv = xfrm_proc_init(net);
2831 if (rv < 0)
2832 free_percpu(net->mib.xfrm_statistics);
2833 return rv;
2834 }
2835
2836 static void xfrm_statistics_fini(struct net *net)
2837 {
2838 xfrm_proc_fini(net);
2839 free_percpu(net->mib.xfrm_statistics);
2840 }
2841 #else
2842 static int __net_init xfrm_statistics_init(struct net *net)
2843 {
2844 return 0;
2845 }
2846
2847 static void xfrm_statistics_fini(struct net *net)
2848 {
2849 }
2850 #endif
2851
2852 static int __net_init xfrm_policy_init(struct net *net)
2853 {
2854 unsigned int hmask, sz;
2855 int dir;
2856
2857 if (net_eq(net, &init_net))
2858 xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
2859 sizeof(struct xfrm_dst),
2860 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
2861 NULL);
2862
2863 hmask = 8 - 1;
2864 sz = (hmask+1) * sizeof(struct hlist_head);
2865
2866 net->xfrm.policy_byidx = xfrm_hash_alloc(sz);
2867 if (!net->xfrm.policy_byidx)
2868 goto out_byidx;
2869 net->xfrm.policy_idx_hmask = hmask;
2870
2871 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
2872 struct xfrm_policy_hash *htab;
2873
2874 net->xfrm.policy_count[dir] = 0;
2875 net->xfrm.policy_count[XFRM_POLICY_MAX + dir] = 0;
2876 INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
2877
2878 htab = &net->xfrm.policy_bydst[dir];
2879 htab->table = xfrm_hash_alloc(sz);
2880 if (!htab->table)
2881 goto out_bydst;
2882 htab->hmask = hmask;
2883 htab->dbits4 = 32;
2884 htab->sbits4 = 32;
2885 htab->dbits6 = 128;
2886 htab->sbits6 = 128;
2887 }
2888 net->xfrm.policy_hthresh.lbits4 = 32;
2889 net->xfrm.policy_hthresh.rbits4 = 32;
2890 net->xfrm.policy_hthresh.lbits6 = 128;
2891 net->xfrm.policy_hthresh.rbits6 = 128;
2892
2893 seqlock_init(&net->xfrm.policy_hthresh.lock);
2894
2895 INIT_LIST_HEAD(&net->xfrm.policy_all);
2896 INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
2897 INIT_WORK(&net->xfrm.policy_hthresh.work, xfrm_hash_rebuild);
2898 if (net_eq(net, &init_net))
2899 xfrm_dev_init();
2900 return 0;
2901
2902 out_bydst:
2903 for (dir--; dir >= 0; dir--) {
2904 struct xfrm_policy_hash *htab;
2905
2906 htab = &net->xfrm.policy_bydst[dir];
2907 xfrm_hash_free(htab->table, sz);
2908 }
2909 xfrm_hash_free(net->xfrm.policy_byidx, sz);
2910 out_byidx:
2911 return -ENOMEM;
2912 }
2913
2914 static void xfrm_policy_fini(struct net *net)
2915 {
2916 unsigned int sz;
2917 int dir;
2918
2919 flush_work(&net->xfrm.policy_hash_work);
2920 #ifdef CONFIG_XFRM_SUB_POLICY
2921 xfrm_policy_flush(net, XFRM_POLICY_TYPE_SUB, false);
2922 #endif
2923 xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, false);
2924
2925 WARN_ON(!list_empty(&net->xfrm.policy_all));
2926
2927 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
2928 struct xfrm_policy_hash *htab;
2929
2930 WARN_ON(!hlist_empty(&net->xfrm.policy_inexact[dir]));
2931
2932 htab = &net->xfrm.policy_bydst[dir];
2933 sz = (htab->hmask + 1) * sizeof(struct hlist_head);
2934 WARN_ON(!hlist_empty(htab->table));
2935 xfrm_hash_free(htab->table, sz);
2936 }
2937
2938 sz = (net->xfrm.policy_idx_hmask + 1) * sizeof(struct hlist_head);
2939 WARN_ON(!hlist_empty(net->xfrm.policy_byidx));
2940 xfrm_hash_free(net->xfrm.policy_byidx, sz);
2941 }
2942
2943 static int __net_init xfrm_net_init(struct net *net)
2944 {
2945 int rv;
2946
2947 /* Initialize the per-net locks here */
2948 spin_lock_init(&net->xfrm.xfrm_state_lock);
2949 spin_lock_init(&net->xfrm.xfrm_policy_lock);
2950 mutex_init(&net->xfrm.xfrm_cfg_mutex);
2951
2952 rv = xfrm_statistics_init(net);
2953 if (rv < 0)
2954 goto out_statistics;
2955 rv = xfrm_state_init(net);
2956 if (rv < 0)
2957 goto out_state;
2958 rv = xfrm_policy_init(net);
2959 if (rv < 0)
2960 goto out_policy;
2961 rv = xfrm_sysctl_init(net);
2962 if (rv < 0)
2963 goto out_sysctl;
2964
2965 return 0;
2966
2967 out_sysctl:
2968 xfrm_policy_fini(net);
2969 out_policy:
2970 xfrm_state_fini(net);
2971 out_state:
2972 xfrm_statistics_fini(net);
2973 out_statistics:
2974 return rv;
2975 }
2976
2977 static void __net_exit xfrm_net_exit(struct net *net)
2978 {
2979 xfrm_sysctl_fini(net);
2980 xfrm_policy_fini(net);
2981 xfrm_state_fini(net);
2982 xfrm_statistics_fini(net);
2983 }
2984
2985 static struct pernet_operations __net_initdata xfrm_net_ops = {
2986 .init = xfrm_net_init,
2987 .exit = xfrm_net_exit,
2988 };
2989
2990 void __init xfrm_init(void)
2991 {
2992 int i;
2993
2994 xfrm_pcpu_work = kmalloc_array(NR_CPUS, sizeof(*xfrm_pcpu_work),
2995 GFP_KERNEL);
2996 BUG_ON(!xfrm_pcpu_work);
2997
2998 for (i = 0; i < NR_CPUS; i++)
2999 INIT_WORK(&xfrm_pcpu_work[i], xfrm_pcpu_work_fn);
3000
3001 register_pernet_subsys(&xfrm_net_ops);
3002 seqcount_init(&xfrm_policy_hash_generation);
3003 xfrm_input_init();
3004 }
3005
3006 #ifdef CONFIG_AUDITSYSCALL
3007 static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
3008 struct audit_buffer *audit_buf)
3009 {
3010 struct xfrm_sec_ctx *ctx = xp->security;
3011 struct xfrm_selector *sel = &xp->selector;
3012
3013 if (ctx)
3014 audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
3015 ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str);
3016
3017 switch (sel->family) {
3018 case AF_INET:
3019 audit_log_format(audit_buf, " src=%pI4", &sel->saddr.a4);
3020 if (sel->prefixlen_s != 32)
3021 audit_log_format(audit_buf, " src_prefixlen=%d",
3022 sel->prefixlen_s);
3023 audit_log_format(audit_buf, " dst=%pI4", &sel->daddr.a4);
3024 if (sel->prefixlen_d != 32)
3025 audit_log_format(audit_buf, " dst_prefixlen=%d",
3026 sel->prefixlen_d);
3027 break;
3028 case AF_INET6:
3029 audit_log_format(audit_buf, " src=%pI6", sel->saddr.a6);
3030 if (sel->prefixlen_s != 128)
3031 audit_log_format(audit_buf, " src_prefixlen=%d",
3032 sel->prefixlen_s);
3033 audit_log_format(audit_buf, " dst=%pI6", sel->daddr.a6);
3034 if (sel->prefixlen_d != 128)
3035 audit_log_format(audit_buf, " dst_prefixlen=%d",
3036 sel->prefixlen_d);
3037 break;
3038 }
3039 }
3040
3041 void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid)
3042 {
3043 struct audit_buffer *audit_buf;
3044
3045 audit_buf = xfrm_audit_start("SPD-add");
3046 if (audit_buf == NULL)
3047 return;
3048 xfrm_audit_helper_usrinfo(task_valid, audit_buf);
3049 audit_log_format(audit_buf, " res=%u", result);
3050 xfrm_audit_common_policyinfo(xp, audit_buf);
3051 audit_log_end(audit_buf);
3052 }
3053 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
3054
3055 void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
3056 bool task_valid)
3057 {
3058 struct audit_buffer *audit_buf;
3059
3060 audit_buf = xfrm_audit_start("SPD-delete");
3061 if (audit_buf == NULL)
3062 return;
3063 xfrm_audit_helper_usrinfo(task_valid, audit_buf);
3064 audit_log_format(audit_buf, " res=%u", result);
3065 xfrm_audit_common_policyinfo(xp, audit_buf);
3066 audit_log_end(audit_buf);
3067 }
3068 EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
3069 #endif
3070
3071 #ifdef CONFIG_XFRM_MIGRATE
3072 static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp,
3073 const struct xfrm_selector *sel_tgt)
3074 {
3075 if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
3076 if (sel_tgt->family == sel_cmp->family &&
3077 xfrm_addr_equal(&sel_tgt->daddr, &sel_cmp->daddr,
3078 sel_cmp->family) &&
3079 xfrm_addr_equal(&sel_tgt->saddr, &sel_cmp->saddr,
3080 sel_cmp->family) &&
3081 sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
3082 sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
3083 return true;
3084 }
3085 } else {
3086 if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
3087 return true;
3088 }
3089 }
3090 return false;
3091 }
3092
3093 static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector *sel,
3094 u8 dir, u8 type, struct net *net)
3095 {
3096 struct xfrm_policy *pol, *ret = NULL;
3097 struct hlist_head *chain;
3098 u32 priority = ~0U;
3099
3100 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
3101 chain = policy_hash_direct(net, &sel->daddr, &sel->saddr, sel->family, dir);
3102 hlist_for_each_entry(pol, chain, bydst) {
3103 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
3104 pol->type == type) {
3105 ret = pol;
3106 priority = ret->priority;
3107 break;
3108 }
3109 }
3110 chain = &net->xfrm.policy_inexact[dir];
3111 hlist_for_each_entry(pol, chain, bydst) {
3112 if ((pol->priority >= priority) && ret)
3113 break;
3114
3115 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
3116 pol->type == type) {
3117 ret = pol;
3118 break;
3119 }
3120 }
3121
3122 xfrm_pol_hold(ret);
3123
3124 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
3125
3126 return ret;
3127 }
3128
3129 static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t)
3130 {
3131 int match = 0;
3132
3133 if (t->mode == m->mode && t->id.proto == m->proto &&
3134 (m->reqid == 0 || t->reqid == m->reqid)) {
3135 switch (t->mode) {
3136 case XFRM_MODE_TUNNEL:
3137 case XFRM_MODE_BEET:
3138 if (xfrm_addr_equal(&t->id.daddr, &m->old_daddr,
3139 m->old_family) &&
3140 xfrm_addr_equal(&t->saddr, &m->old_saddr,
3141 m->old_family)) {
3142 match = 1;
3143 }
3144 break;
3145 case XFRM_MODE_TRANSPORT:
3146 /* in case of transport mode, template does not store
3147 any IP addresses, hence we just compare mode and
3148 protocol */
3149 match = 1;
3150 break;
3151 default:
3152 break;
3153 }
3154 }
3155 return match;
3156 }
3157
3158 /* update endpoint address(es) of template(s) */
3159 static int xfrm_policy_migrate(struct xfrm_policy *pol,
3160 struct xfrm_migrate *m, int num_migrate)
3161 {
3162 struct xfrm_migrate *mp;
3163 int i, j, n = 0;
3164
3165 write_lock_bh(&pol->lock);
3166 if (unlikely(pol->walk.dead)) {
3167 /* target policy has been deleted */
3168 write_unlock_bh(&pol->lock);
3169 return -ENOENT;
3170 }
3171
3172 for (i = 0; i < pol->xfrm_nr; i++) {
3173 for (j = 0, mp = m; j < num_migrate; j++, mp++) {
3174 if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
3175 continue;
3176 n++;
3177 if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
3178 pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
3179 continue;
3180 /* update endpoints */
3181 memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
3182 sizeof(pol->xfrm_vec[i].id.daddr));
3183 memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
3184 sizeof(pol->xfrm_vec[i].saddr));
3185 pol->xfrm_vec[i].encap_family = mp->new_family;
3186 /* flush bundles */
3187 atomic_inc(&pol->genid);
3188 }
3189 }
3190
3191 write_unlock_bh(&pol->lock);
3192
3193 if (!n)
3194 return -ENODATA;
3195
3196 return 0;
3197 }
3198
3199 static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate)
3200 {
3201 int i, j;
3202
3203 if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
3204 return -EINVAL;
3205
3206 for (i = 0; i < num_migrate; i++) {
3207 if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
3208 xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
3209 return -EINVAL;
3210
3211 /* check if there is any duplicated entry */
3212 for (j = i + 1; j < num_migrate; j++) {
3213 if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
3214 sizeof(m[i].old_daddr)) &&
3215 !memcmp(&m[i].old_saddr, &m[j].old_saddr,
3216 sizeof(m[i].old_saddr)) &&
3217 m[i].proto == m[j].proto &&
3218 m[i].mode == m[j].mode &&
3219 m[i].reqid == m[j].reqid &&
3220 m[i].old_family == m[j].old_family)
3221 return -EINVAL;
3222 }
3223 }
3224
3225 return 0;
3226 }
3227
3228 int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
3229 struct xfrm_migrate *m, int num_migrate,
3230 struct xfrm_kmaddress *k, struct net *net,
3231 struct xfrm_encap_tmpl *encap)
3232 {
3233 int i, err, nx_cur = 0, nx_new = 0;
3234 struct xfrm_policy *pol = NULL;
3235 struct xfrm_state *x, *xc;
3236 struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
3237 struct xfrm_state *x_new[XFRM_MAX_DEPTH];
3238 struct xfrm_migrate *mp;
3239
3240 /* Stage 0 - sanity checks */
3241 if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
3242 goto out;
3243
3244 if (dir >= XFRM_POLICY_MAX) {
3245 err = -EINVAL;
3246 goto out;
3247 }
3248
3249 /* Stage 1 - find policy */
3250 if ((pol = xfrm_migrate_policy_find(sel, dir, type, net)) == NULL) {
3251 err = -ENOENT;
3252 goto out;
3253 }
3254
3255 /* Stage 2 - find and update state(s) */
3256 for (i = 0, mp = m; i < num_migrate; i++, mp++) {
3257 if ((x = xfrm_migrate_state_find(mp, net))) {
3258 x_cur[nx_cur] = x;
3259 nx_cur++;
3260 xc = xfrm_state_migrate(x, mp, encap);
3261 if (xc) {
3262 x_new[nx_new] = xc;
3263 nx_new++;
3264 } else {
3265 err = -ENODATA;
3266 goto restore_state;
3267 }
3268 }
3269 }
3270
3271 /* Stage 3 - update policy */
3272 if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
3273 goto restore_state;
3274
3275 /* Stage 4 - delete old state(s) */
3276 if (nx_cur) {
3277 xfrm_states_put(x_cur, nx_cur);
3278 xfrm_states_delete(x_cur, nx_cur);
3279 }
3280
3281 /* Stage 5 - announce */
3282 km_migrate(sel, dir, type, m, num_migrate, k, encap);
3283
3284 xfrm_pol_put(pol);
3285
3286 return 0;
3287 out:
3288 return err;
3289
3290 restore_state:
3291 if (pol)
3292 xfrm_pol_put(pol);
3293 if (nx_cur)
3294 xfrm_states_put(x_cur, nx_cur);
3295 if (nx_new)
3296 xfrm_states_delete(x_new, nx_new);
3297
3298 return err;
3299 }
3300 EXPORT_SYMBOL(xfrm_migrate);
3301 #endif
Linux with added FPC-III support