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Merge tag 'for-4.15/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git...
[mirror_ubuntu-bionic-kernel.git] / net / xfrm / xfrm_policy.c
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 dst_entry *dst);
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 = xp_net(pol);
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 = 0;
1462
1463 afinfo = xfrm_policy_get_afinfo(family);
1464 tos = afinfo ? afinfo->get_tos(fl) : 0;
1465
1466 rcu_read_unlock();
1467
1468 return tos;
1469 }
1470
1471 static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
1472 {
1473 const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1474 struct dst_ops *dst_ops;
1475 struct xfrm_dst *xdst;
1476
1477 if (!afinfo)
1478 return ERR_PTR(-EINVAL);
1479
1480 switch (family) {
1481 case AF_INET:
1482 dst_ops = &net->xfrm.xfrm4_dst_ops;
1483 break;
1484 #if IS_ENABLED(CONFIG_IPV6)
1485 case AF_INET6:
1486 dst_ops = &net->xfrm.xfrm6_dst_ops;
1487 break;
1488 #endif
1489 default:
1490 BUG();
1491 }
1492 xdst = dst_alloc(dst_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
1493
1494 if (likely(xdst)) {
1495 struct dst_entry *dst = &xdst->u.dst;
1496
1497 memset(dst + 1, 0, sizeof(*xdst) - sizeof(*dst));
1498 } else
1499 xdst = ERR_PTR(-ENOBUFS);
1500
1501 rcu_read_unlock();
1502
1503 return xdst;
1504 }
1505
1506 static inline int xfrm_init_path(struct xfrm_dst *path, struct dst_entry *dst,
1507 int nfheader_len)
1508 {
1509 const struct xfrm_policy_afinfo *afinfo =
1510 xfrm_policy_get_afinfo(dst->ops->family);
1511 int err;
1512
1513 if (!afinfo)
1514 return -EINVAL;
1515
1516 err = afinfo->init_path(path, dst, nfheader_len);
1517
1518 rcu_read_unlock();
1519
1520 return err;
1521 }
1522
1523 static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
1524 const struct flowi *fl)
1525 {
1526 const struct xfrm_policy_afinfo *afinfo =
1527 xfrm_policy_get_afinfo(xdst->u.dst.ops->family);
1528 int err;
1529
1530 if (!afinfo)
1531 return -EINVAL;
1532
1533 err = afinfo->fill_dst(xdst, dev, fl);
1534
1535 rcu_read_unlock();
1536
1537 return err;
1538 }
1539
1540
1541 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
1542 * all the metrics... Shortly, bundle a bundle.
1543 */
1544
1545 static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
1546 struct xfrm_state **xfrm, int nx,
1547 const struct flowi *fl,
1548 struct dst_entry *dst)
1549 {
1550 struct net *net = xp_net(policy);
1551 unsigned long now = jiffies;
1552 struct net_device *dev;
1553 struct xfrm_mode *inner_mode;
1554 struct dst_entry *dst_prev = NULL;
1555 struct dst_entry *dst0 = NULL;
1556 int i = 0;
1557 int err;
1558 int header_len = 0;
1559 int nfheader_len = 0;
1560 int trailer_len = 0;
1561 int tos;
1562 int family = policy->selector.family;
1563 xfrm_address_t saddr, daddr;
1564
1565 xfrm_flowi_addr_get(fl, &saddr, &daddr, family);
1566
1567 tos = xfrm_get_tos(fl, family);
1568
1569 dst_hold(dst);
1570
1571 for (; i < nx; i++) {
1572 struct xfrm_dst *xdst = xfrm_alloc_dst(net, family);
1573 struct dst_entry *dst1 = &xdst->u.dst;
1574
1575 err = PTR_ERR(xdst);
1576 if (IS_ERR(xdst)) {
1577 dst_release(dst);
1578 goto put_states;
1579 }
1580
1581 if (!dst_prev)
1582 dst0 = dst1;
1583 else
1584 /* Ref count is taken during xfrm_alloc_dst()
1585 * No need to do dst_clone() on dst1
1586 */
1587 dst_prev->child = dst1;
1588
1589 if (xfrm[i]->sel.family == AF_UNSPEC) {
1590 inner_mode = xfrm_ip2inner_mode(xfrm[i],
1591 xfrm_af2proto(family));
1592 if (!inner_mode) {
1593 err = -EAFNOSUPPORT;
1594 dst_release(dst);
1595 goto put_states;
1596 }
1597 } else
1598 inner_mode = xfrm[i]->inner_mode;
1599
1600 xdst->route = dst;
1601 dst_copy_metrics(dst1, dst);
1602
1603 if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
1604 family = xfrm[i]->props.family;
1605 dst = xfrm_dst_lookup(xfrm[i], tos, fl->flowi_oif,
1606 &saddr, &daddr, family,
1607 xfrm[i]->props.output_mark);
1608 err = PTR_ERR(dst);
1609 if (IS_ERR(dst))
1610 goto put_states;
1611 } else
1612 dst_hold(dst);
1613
1614 dst1->xfrm = xfrm[i];
1615 xdst->xfrm_genid = xfrm[i]->genid;
1616
1617 dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
1618 dst1->flags |= DST_HOST;
1619 dst1->lastuse = now;
1620
1621 dst1->input = dst_discard;
1622 dst1->output = inner_mode->afinfo->output;
1623
1624 dst1->next = dst_prev;
1625 dst_prev = dst1;
1626
1627 header_len += xfrm[i]->props.header_len;
1628 if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
1629 nfheader_len += xfrm[i]->props.header_len;
1630 trailer_len += xfrm[i]->props.trailer_len;
1631 }
1632
1633 dst_prev->child = dst;
1634 dst0->path = dst;
1635
1636 err = -ENODEV;
1637 dev = dst->dev;
1638 if (!dev)
1639 goto free_dst;
1640
1641 xfrm_init_path((struct xfrm_dst *)dst0, dst, nfheader_len);
1642 xfrm_init_pmtu(dst_prev);
1643
1644 for (dst_prev = dst0; dst_prev != dst; dst_prev = dst_prev->child) {
1645 struct xfrm_dst *xdst = (struct xfrm_dst *)dst_prev;
1646
1647 err = xfrm_fill_dst(xdst, dev, fl);
1648 if (err)
1649 goto free_dst;
1650
1651 dst_prev->header_len = header_len;
1652 dst_prev->trailer_len = trailer_len;
1653 header_len -= xdst->u.dst.xfrm->props.header_len;
1654 trailer_len -= xdst->u.dst.xfrm->props.trailer_len;
1655 }
1656
1657 out:
1658 return dst0;
1659
1660 put_states:
1661 for (; i < nx; i++)
1662 xfrm_state_put(xfrm[i]);
1663 free_dst:
1664 if (dst0)
1665 dst_release_immediate(dst0);
1666 dst0 = ERR_PTR(err);
1667 goto out;
1668 }
1669
1670 static int xfrm_expand_policies(const struct flowi *fl, u16 family,
1671 struct xfrm_policy **pols,
1672 int *num_pols, int *num_xfrms)
1673 {
1674 int i;
1675
1676 if (*num_pols == 0 || !pols[0]) {
1677 *num_pols = 0;
1678 *num_xfrms = 0;
1679 return 0;
1680 }
1681 if (IS_ERR(pols[0]))
1682 return PTR_ERR(pols[0]);
1683
1684 *num_xfrms = pols[0]->xfrm_nr;
1685
1686 #ifdef CONFIG_XFRM_SUB_POLICY
1687 if (pols[0] && pols[0]->action == XFRM_POLICY_ALLOW &&
1688 pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1689 pols[1] = xfrm_policy_lookup_bytype(xp_net(pols[0]),
1690 XFRM_POLICY_TYPE_MAIN,
1691 fl, family,
1692 XFRM_POLICY_OUT);
1693 if (pols[1]) {
1694 if (IS_ERR(pols[1])) {
1695 xfrm_pols_put(pols, *num_pols);
1696 return PTR_ERR(pols[1]);
1697 }
1698 (*num_pols)++;
1699 (*num_xfrms) += pols[1]->xfrm_nr;
1700 }
1701 }
1702 #endif
1703 for (i = 0; i < *num_pols; i++) {
1704 if (pols[i]->action != XFRM_POLICY_ALLOW) {
1705 *num_xfrms = -1;
1706 break;
1707 }
1708 }
1709
1710 return 0;
1711
1712 }
1713
1714 static void xfrm_last_dst_update(struct xfrm_dst *xdst, struct xfrm_dst *old)
1715 {
1716 this_cpu_write(xfrm_last_dst, xdst);
1717 if (old)
1718 dst_release(&old->u.dst);
1719 }
1720
1721 static void __xfrm_pcpu_work_fn(void)
1722 {
1723 struct xfrm_dst *old;
1724
1725 old = this_cpu_read(xfrm_last_dst);
1726 if (old && !xfrm_bundle_ok(old))
1727 xfrm_last_dst_update(NULL, old);
1728 }
1729
1730 static void xfrm_pcpu_work_fn(struct work_struct *work)
1731 {
1732 local_bh_disable();
1733 rcu_read_lock();
1734 __xfrm_pcpu_work_fn();
1735 rcu_read_unlock();
1736 local_bh_enable();
1737 }
1738
1739 void xfrm_policy_cache_flush(void)
1740 {
1741 struct xfrm_dst *old;
1742 bool found = 0;
1743 int cpu;
1744
1745 might_sleep();
1746
1747 local_bh_disable();
1748 rcu_read_lock();
1749 for_each_possible_cpu(cpu) {
1750 old = per_cpu(xfrm_last_dst, cpu);
1751 if (old && !xfrm_bundle_ok(old)) {
1752 if (smp_processor_id() == cpu) {
1753 __xfrm_pcpu_work_fn();
1754 continue;
1755 }
1756 found = true;
1757 break;
1758 }
1759 }
1760
1761 rcu_read_unlock();
1762 local_bh_enable();
1763
1764 if (!found)
1765 return;
1766
1767 get_online_cpus();
1768
1769 for_each_possible_cpu(cpu) {
1770 bool bundle_release;
1771
1772 rcu_read_lock();
1773 old = per_cpu(xfrm_last_dst, cpu);
1774 bundle_release = old && !xfrm_bundle_ok(old);
1775 rcu_read_unlock();
1776
1777 if (!bundle_release)
1778 continue;
1779
1780 if (cpu_online(cpu)) {
1781 schedule_work_on(cpu, &xfrm_pcpu_work[cpu]);
1782 continue;
1783 }
1784
1785 rcu_read_lock();
1786 old = per_cpu(xfrm_last_dst, cpu);
1787 if (old && !xfrm_bundle_ok(old)) {
1788 per_cpu(xfrm_last_dst, cpu) = NULL;
1789 dst_release(&old->u.dst);
1790 }
1791 rcu_read_unlock();
1792 }
1793
1794 put_online_cpus();
1795 }
1796
1797 static bool xfrm_xdst_can_reuse(struct xfrm_dst *xdst,
1798 struct xfrm_state * const xfrm[],
1799 int num)
1800 {
1801 const struct dst_entry *dst = &xdst->u.dst;
1802 int i;
1803
1804 if (xdst->num_xfrms != num)
1805 return false;
1806
1807 for (i = 0; i < num; i++) {
1808 if (!dst || dst->xfrm != xfrm[i])
1809 return false;
1810 dst = dst->child;
1811 }
1812
1813 return xfrm_bundle_ok(xdst);
1814 }
1815
1816 static struct xfrm_dst *
1817 xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
1818 const struct flowi *fl, u16 family,
1819 struct dst_entry *dst_orig)
1820 {
1821 struct net *net = xp_net(pols[0]);
1822 struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
1823 struct xfrm_dst *xdst, *old;
1824 struct dst_entry *dst;
1825 int err;
1826
1827 /* Try to instantiate a bundle */
1828 err = xfrm_tmpl_resolve(pols, num_pols, fl, xfrm, family);
1829 if (err <= 0) {
1830 if (err != 0 && err != -EAGAIN)
1831 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
1832 return ERR_PTR(err);
1833 }
1834
1835 xdst = this_cpu_read(xfrm_last_dst);
1836 if (xdst &&
1837 xdst->u.dst.dev == dst_orig->dev &&
1838 xdst->num_pols == num_pols &&
1839 memcmp(xdst->pols, pols,
1840 sizeof(struct xfrm_policy *) * num_pols) == 0 &&
1841 xfrm_xdst_can_reuse(xdst, xfrm, err)) {
1842 dst_hold(&xdst->u.dst);
1843 xfrm_pols_put(pols, num_pols);
1844 while (err > 0)
1845 xfrm_state_put(xfrm[--err]);
1846 return xdst;
1847 }
1848
1849 old = xdst;
1850
1851 dst = xfrm_bundle_create(pols[0], xfrm, err, fl, dst_orig);
1852 if (IS_ERR(dst)) {
1853 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR);
1854 return ERR_CAST(dst);
1855 }
1856
1857 xdst = (struct xfrm_dst *)dst;
1858 xdst->num_xfrms = err;
1859 xdst->num_pols = num_pols;
1860 memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
1861 xdst->policy_genid = atomic_read(&pols[0]->genid);
1862
1863 atomic_set(&xdst->u.dst.__refcnt, 2);
1864 xfrm_last_dst_update(xdst, old);
1865
1866 return xdst;
1867 }
1868
1869 static void xfrm_policy_queue_process(struct timer_list *t)
1870 {
1871 struct sk_buff *skb;
1872 struct sock *sk;
1873 struct dst_entry *dst;
1874 struct xfrm_policy *pol = from_timer(pol, t, polq.hold_timer);
1875 struct net *net = xp_net(pol);
1876 struct xfrm_policy_queue *pq = &pol->polq;
1877 struct flowi fl;
1878 struct sk_buff_head list;
1879
1880 spin_lock(&pq->hold_queue.lock);
1881 skb = skb_peek(&pq->hold_queue);
1882 if (!skb) {
1883 spin_unlock(&pq->hold_queue.lock);
1884 goto out;
1885 }
1886 dst = skb_dst(skb);
1887 sk = skb->sk;
1888 xfrm_decode_session(skb, &fl, dst->ops->family);
1889 spin_unlock(&pq->hold_queue.lock);
1890
1891 dst_hold(dst->path);
1892 dst = xfrm_lookup(net, dst->path, &fl, sk, 0);
1893 if (IS_ERR(dst))
1894 goto purge_queue;
1895
1896 if (dst->flags & DST_XFRM_QUEUE) {
1897 dst_release(dst);
1898
1899 if (pq->timeout >= XFRM_QUEUE_TMO_MAX)
1900 goto purge_queue;
1901
1902 pq->timeout = pq->timeout << 1;
1903 if (!mod_timer(&pq->hold_timer, jiffies + pq->timeout))
1904 xfrm_pol_hold(pol);
1905 goto out;
1906 }
1907
1908 dst_release(dst);
1909
1910 __skb_queue_head_init(&list);
1911
1912 spin_lock(&pq->hold_queue.lock);
1913 pq->timeout = 0;
1914 skb_queue_splice_init(&pq->hold_queue, &list);
1915 spin_unlock(&pq->hold_queue.lock);
1916
1917 while (!skb_queue_empty(&list)) {
1918 skb = __skb_dequeue(&list);
1919
1920 xfrm_decode_session(skb, &fl, skb_dst(skb)->ops->family);
1921 dst_hold(skb_dst(skb)->path);
1922 dst = xfrm_lookup(net, skb_dst(skb)->path, &fl, skb->sk, 0);
1923 if (IS_ERR(dst)) {
1924 kfree_skb(skb);
1925 continue;
1926 }
1927
1928 nf_reset(skb);
1929 skb_dst_drop(skb);
1930 skb_dst_set(skb, dst);
1931
1932 dst_output(net, skb->sk, skb);
1933 }
1934
1935 out:
1936 xfrm_pol_put(pol);
1937 return;
1938
1939 purge_queue:
1940 pq->timeout = 0;
1941 skb_queue_purge(&pq->hold_queue);
1942 xfrm_pol_put(pol);
1943 }
1944
1945 static int xdst_queue_output(struct net *net, struct sock *sk, struct sk_buff *skb)
1946 {
1947 unsigned long sched_next;
1948 struct dst_entry *dst = skb_dst(skb);
1949 struct xfrm_dst *xdst = (struct xfrm_dst *) dst;
1950 struct xfrm_policy *pol = xdst->pols[0];
1951 struct xfrm_policy_queue *pq = &pol->polq;
1952
1953 if (unlikely(skb_fclone_busy(sk, skb))) {
1954 kfree_skb(skb);
1955 return 0;
1956 }
1957
1958 if (pq->hold_queue.qlen > XFRM_MAX_QUEUE_LEN) {
1959 kfree_skb(skb);
1960 return -EAGAIN;
1961 }
1962
1963 skb_dst_force(skb);
1964
1965 spin_lock_bh(&pq->hold_queue.lock);
1966
1967 if (!pq->timeout)
1968 pq->timeout = XFRM_QUEUE_TMO_MIN;
1969
1970 sched_next = jiffies + pq->timeout;
1971
1972 if (del_timer(&pq->hold_timer)) {
1973 if (time_before(pq->hold_timer.expires, sched_next))
1974 sched_next = pq->hold_timer.expires;
1975 xfrm_pol_put(pol);
1976 }
1977
1978 __skb_queue_tail(&pq->hold_queue, skb);
1979 if (!mod_timer(&pq->hold_timer, sched_next))
1980 xfrm_pol_hold(pol);
1981
1982 spin_unlock_bh(&pq->hold_queue.lock);
1983
1984 return 0;
1985 }
1986
1987 static struct xfrm_dst *xfrm_create_dummy_bundle(struct net *net,
1988 struct xfrm_flo *xflo,
1989 const struct flowi *fl,
1990 int num_xfrms,
1991 u16 family)
1992 {
1993 int err;
1994 struct net_device *dev;
1995 struct dst_entry *dst;
1996 struct dst_entry *dst1;
1997 struct xfrm_dst *xdst;
1998
1999 xdst = xfrm_alloc_dst(net, family);
2000 if (IS_ERR(xdst))
2001 return xdst;
2002
2003 if (!(xflo->flags & XFRM_LOOKUP_QUEUE) ||
2004 net->xfrm.sysctl_larval_drop ||
2005 num_xfrms <= 0)
2006 return xdst;
2007
2008 dst = xflo->dst_orig;
2009 dst1 = &xdst->u.dst;
2010 dst_hold(dst);
2011 xdst->route = dst;
2012
2013 dst_copy_metrics(dst1, dst);
2014
2015 dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
2016 dst1->flags |= DST_HOST | DST_XFRM_QUEUE;
2017 dst1->lastuse = jiffies;
2018
2019 dst1->input = dst_discard;
2020 dst1->output = xdst_queue_output;
2021
2022 dst_hold(dst);
2023 dst1->child = dst;
2024 dst1->path = dst;
2025
2026 xfrm_init_path((struct xfrm_dst *)dst1, dst, 0);
2027
2028 err = -ENODEV;
2029 dev = dst->dev;
2030 if (!dev)
2031 goto free_dst;
2032
2033 err = xfrm_fill_dst(xdst, dev, fl);
2034 if (err)
2035 goto free_dst;
2036
2037 out:
2038 return xdst;
2039
2040 free_dst:
2041 dst_release(dst1);
2042 xdst = ERR_PTR(err);
2043 goto out;
2044 }
2045
2046 static struct xfrm_dst *
2047 xfrm_bundle_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir, struct xfrm_flo *xflo)
2048 {
2049 struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2050 int num_pols = 0, num_xfrms = 0, err;
2051 struct xfrm_dst *xdst;
2052
2053 /* Resolve policies to use if we couldn't get them from
2054 * previous cache entry */
2055 num_pols = 1;
2056 pols[0] = xfrm_policy_lookup(net, fl, family, dir);
2057 err = xfrm_expand_policies(fl, family, pols,
2058 &num_pols, &num_xfrms);
2059 if (err < 0)
2060 goto inc_error;
2061 if (num_pols == 0)
2062 return NULL;
2063 if (num_xfrms <= 0)
2064 goto make_dummy_bundle;
2065
2066 local_bh_disable();
2067 xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family,
2068 xflo->dst_orig);
2069 local_bh_enable();
2070
2071 if (IS_ERR(xdst)) {
2072 err = PTR_ERR(xdst);
2073 if (err != -EAGAIN)
2074 goto error;
2075 goto make_dummy_bundle;
2076 } else if (xdst == NULL) {
2077 num_xfrms = 0;
2078 goto make_dummy_bundle;
2079 }
2080
2081 return xdst;
2082
2083 make_dummy_bundle:
2084 /* We found policies, but there's no bundles to instantiate:
2085 * either because the policy blocks, has no transformations or
2086 * we could not build template (no xfrm_states).*/
2087 xdst = xfrm_create_dummy_bundle(net, xflo, fl, num_xfrms, family);
2088 if (IS_ERR(xdst)) {
2089 xfrm_pols_put(pols, num_pols);
2090 return ERR_CAST(xdst);
2091 }
2092 xdst->num_pols = num_pols;
2093 xdst->num_xfrms = num_xfrms;
2094 memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
2095
2096 return xdst;
2097
2098 inc_error:
2099 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
2100 error:
2101 xfrm_pols_put(pols, num_pols);
2102 return ERR_PTR(err);
2103 }
2104
2105 static struct dst_entry *make_blackhole(struct net *net, u16 family,
2106 struct dst_entry *dst_orig)
2107 {
2108 const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2109 struct dst_entry *ret;
2110
2111 if (!afinfo) {
2112 dst_release(dst_orig);
2113 return ERR_PTR(-EINVAL);
2114 } else {
2115 ret = afinfo->blackhole_route(net, dst_orig);
2116 }
2117 rcu_read_unlock();
2118
2119 return ret;
2120 }
2121
2122 /* Main function: finds/creates a bundle for given flow.
2123 *
2124 * At the moment we eat a raw IP route. Mostly to speed up lookups
2125 * on interfaces with disabled IPsec.
2126 */
2127 struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
2128 const struct flowi *fl,
2129 const struct sock *sk, int flags)
2130 {
2131 struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2132 struct xfrm_dst *xdst;
2133 struct dst_entry *dst, *route;
2134 u16 family = dst_orig->ops->family;
2135 u8 dir = XFRM_POLICY_OUT;
2136 int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
2137
2138 dst = NULL;
2139 xdst = NULL;
2140 route = NULL;
2141
2142 sk = sk_const_to_full_sk(sk);
2143 if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
2144 num_pols = 1;
2145 pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, family);
2146 err = xfrm_expand_policies(fl, family, pols,
2147 &num_pols, &num_xfrms);
2148 if (err < 0)
2149 goto dropdst;
2150
2151 if (num_pols) {
2152 if (num_xfrms <= 0) {
2153 drop_pols = num_pols;
2154 goto no_transform;
2155 }
2156
2157 local_bh_disable();
2158 xdst = xfrm_resolve_and_create_bundle(
2159 pols, num_pols, fl,
2160 family, dst_orig);
2161 local_bh_enable();
2162
2163 if (IS_ERR(xdst)) {
2164 xfrm_pols_put(pols, num_pols);
2165 err = PTR_ERR(xdst);
2166 goto dropdst;
2167 } else if (xdst == NULL) {
2168 num_xfrms = 0;
2169 drop_pols = num_pols;
2170 goto no_transform;
2171 }
2172
2173 route = xdst->route;
2174 }
2175 }
2176
2177 if (xdst == NULL) {
2178 struct xfrm_flo xflo;
2179
2180 xflo.dst_orig = dst_orig;
2181 xflo.flags = flags;
2182
2183 /* To accelerate a bit... */
2184 if ((dst_orig->flags & DST_NOXFRM) ||
2185 !net->xfrm.policy_count[XFRM_POLICY_OUT])
2186 goto nopol;
2187
2188 xdst = xfrm_bundle_lookup(net, fl, family, dir, &xflo);
2189 if (xdst == NULL)
2190 goto nopol;
2191 if (IS_ERR(xdst)) {
2192 err = PTR_ERR(xdst);
2193 goto dropdst;
2194 }
2195
2196 num_pols = xdst->num_pols;
2197 num_xfrms = xdst->num_xfrms;
2198 memcpy(pols, xdst->pols, sizeof(struct xfrm_policy *) * num_pols);
2199 route = xdst->route;
2200 }
2201
2202 dst = &xdst->u.dst;
2203 if (route == NULL && num_xfrms > 0) {
2204 /* The only case when xfrm_bundle_lookup() returns a
2205 * bundle with null route, is when the template could
2206 * not be resolved. It means policies are there, but
2207 * bundle could not be created, since we don't yet
2208 * have the xfrm_state's. We need to wait for KM to
2209 * negotiate new SA's or bail out with error.*/
2210 if (net->xfrm.sysctl_larval_drop) {
2211 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
2212 err = -EREMOTE;
2213 goto error;
2214 }
2215
2216 err = -EAGAIN;
2217
2218 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
2219 goto error;
2220 }
2221
2222 no_transform:
2223 if (num_pols == 0)
2224 goto nopol;
2225
2226 if ((flags & XFRM_LOOKUP_ICMP) &&
2227 !(pols[0]->flags & XFRM_POLICY_ICMP)) {
2228 err = -ENOENT;
2229 goto error;
2230 }
2231
2232 for (i = 0; i < num_pols; i++)
2233 pols[i]->curlft.use_time = get_seconds();
2234
2235 if (num_xfrms < 0) {
2236 /* Prohibit the flow */
2237 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLBLOCK);
2238 err = -EPERM;
2239 goto error;
2240 } else if (num_xfrms > 0) {
2241 /* Flow transformed */
2242 dst_release(dst_orig);
2243 } else {
2244 /* Flow passes untransformed */
2245 dst_release(dst);
2246 dst = dst_orig;
2247 }
2248 ok:
2249 xfrm_pols_put(pols, drop_pols);
2250 if (dst && dst->xfrm &&
2251 dst->xfrm->props.mode == XFRM_MODE_TUNNEL)
2252 dst->flags |= DST_XFRM_TUNNEL;
2253 return dst;
2254
2255 nopol:
2256 if (!(flags & XFRM_LOOKUP_ICMP)) {
2257 dst = dst_orig;
2258 goto ok;
2259 }
2260 err = -ENOENT;
2261 error:
2262 dst_release(dst);
2263 dropdst:
2264 if (!(flags & XFRM_LOOKUP_KEEP_DST_REF))
2265 dst_release(dst_orig);
2266 xfrm_pols_put(pols, drop_pols);
2267 return ERR_PTR(err);
2268 }
2269 EXPORT_SYMBOL(xfrm_lookup);
2270
2271 /* Callers of xfrm_lookup_route() must ensure a call to dst_output().
2272 * Otherwise we may send out blackholed packets.
2273 */
2274 struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
2275 const struct flowi *fl,
2276 const struct sock *sk, int flags)
2277 {
2278 struct dst_entry *dst = xfrm_lookup(net, dst_orig, fl, sk,
2279 flags | XFRM_LOOKUP_QUEUE |
2280 XFRM_LOOKUP_KEEP_DST_REF);
2281
2282 if (IS_ERR(dst) && PTR_ERR(dst) == -EREMOTE)
2283 return make_blackhole(net, dst_orig->ops->family, dst_orig);
2284
2285 return dst;
2286 }
2287 EXPORT_SYMBOL(xfrm_lookup_route);
2288
2289 static inline int
2290 xfrm_secpath_reject(int idx, struct sk_buff *skb, const struct flowi *fl)
2291 {
2292 struct xfrm_state *x;
2293
2294 if (!skb->sp || idx < 0 || idx >= skb->sp->len)
2295 return 0;
2296 x = skb->sp->xvec[idx];
2297 if (!x->type->reject)
2298 return 0;
2299 return x->type->reject(x, skb, fl);
2300 }
2301
2302 /* When skb is transformed back to its "native" form, we have to
2303 * check policy restrictions. At the moment we make this in maximally
2304 * stupid way. Shame on me. :-) Of course, connected sockets must
2305 * have policy cached at them.
2306 */
2307
2308 static inline int
2309 xfrm_state_ok(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x,
2310 unsigned short family)
2311 {
2312 if (xfrm_state_kern(x))
2313 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
2314 return x->id.proto == tmpl->id.proto &&
2315 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
2316 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
2317 x->props.mode == tmpl->mode &&
2318 (tmpl->allalgs || (tmpl->aalgos & (1<<x->props.aalgo)) ||
2319 !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
2320 !(x->props.mode != XFRM_MODE_TRANSPORT &&
2321 xfrm_state_addr_cmp(tmpl, x, family));
2322 }
2323
2324 /*
2325 * 0 or more than 0 is returned when validation is succeeded (either bypass
2326 * because of optional transport mode, or next index of the mathced secpath
2327 * state with the template.
2328 * -1 is returned when no matching template is found.
2329 * Otherwise "-2 - errored_index" is returned.
2330 */
2331 static inline int
2332 xfrm_policy_ok(const struct xfrm_tmpl *tmpl, const struct sec_path *sp, int start,
2333 unsigned short family)
2334 {
2335 int idx = start;
2336
2337 if (tmpl->optional) {
2338 if (tmpl->mode == XFRM_MODE_TRANSPORT)
2339 return start;
2340 } else
2341 start = -1;
2342 for (; idx < sp->len; idx++) {
2343 if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
2344 return ++idx;
2345 if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
2346 if (start == -1)
2347 start = -2-idx;
2348 break;
2349 }
2350 }
2351 return start;
2352 }
2353
2354 int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
2355 unsigned int family, int reverse)
2356 {
2357 const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2358 int err;
2359
2360 if (unlikely(afinfo == NULL))
2361 return -EAFNOSUPPORT;
2362
2363 afinfo->decode_session(skb, fl, reverse);
2364 err = security_xfrm_decode_session(skb, &fl->flowi_secid);
2365 rcu_read_unlock();
2366 return err;
2367 }
2368 EXPORT_SYMBOL(__xfrm_decode_session);
2369
2370 static inline int secpath_has_nontransport(const struct sec_path *sp, int k, int *idxp)
2371 {
2372 for (; k < sp->len; k++) {
2373 if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
2374 *idxp = k;
2375 return 1;
2376 }
2377 }
2378
2379 return 0;
2380 }
2381
2382 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
2383 unsigned short family)
2384 {
2385 struct net *net = dev_net(skb->dev);
2386 struct xfrm_policy *pol;
2387 struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2388 int npols = 0;
2389 int xfrm_nr;
2390 int pi;
2391 int reverse;
2392 struct flowi fl;
2393 int xerr_idx = -1;
2394
2395 reverse = dir & ~XFRM_POLICY_MASK;
2396 dir &= XFRM_POLICY_MASK;
2397
2398 if (__xfrm_decode_session(skb, &fl, family, reverse) < 0) {
2399 XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
2400 return 0;
2401 }
2402
2403 nf_nat_decode_session(skb, &fl, family);
2404
2405 /* First, check used SA against their selectors. */
2406 if (skb->sp) {
2407 int i;
2408
2409 for (i = skb->sp->len-1; i >= 0; i--) {
2410 struct xfrm_state *x = skb->sp->xvec[i];
2411 if (!xfrm_selector_match(&x->sel, &fl, family)) {
2412 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
2413 return 0;
2414 }
2415 }
2416 }
2417
2418 pol = NULL;
2419 sk = sk_to_full_sk(sk);
2420 if (sk && sk->sk_policy[dir]) {
2421 pol = xfrm_sk_policy_lookup(sk, dir, &fl, family);
2422 if (IS_ERR(pol)) {
2423 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2424 return 0;
2425 }
2426 }
2427
2428 if (!pol)
2429 pol = xfrm_policy_lookup(net, &fl, family, dir);
2430
2431 if (IS_ERR(pol)) {
2432 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2433 return 0;
2434 }
2435
2436 if (!pol) {
2437 if (skb->sp && secpath_has_nontransport(skb->sp, 0, &xerr_idx)) {
2438 xfrm_secpath_reject(xerr_idx, skb, &fl);
2439 XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
2440 return 0;
2441 }
2442 return 1;
2443 }
2444
2445 pol->curlft.use_time = get_seconds();
2446
2447 pols[0] = pol;
2448 npols++;
2449 #ifdef CONFIG_XFRM_SUB_POLICY
2450 if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
2451 pols[1] = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN,
2452 &fl, family,
2453 XFRM_POLICY_IN);
2454 if (pols[1]) {
2455 if (IS_ERR(pols[1])) {
2456 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2457 return 0;
2458 }
2459 pols[1]->curlft.use_time = get_seconds();
2460 npols++;
2461 }
2462 }
2463 #endif
2464
2465 if (pol->action == XFRM_POLICY_ALLOW) {
2466 struct sec_path *sp;
2467 static struct sec_path dummy;
2468 struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
2469 struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
2470 struct xfrm_tmpl **tpp = tp;
2471 int ti = 0;
2472 int i, k;
2473
2474 if ((sp = skb->sp) == NULL)
2475 sp = &dummy;
2476
2477 for (pi = 0; pi < npols; pi++) {
2478 if (pols[pi] != pol &&
2479 pols[pi]->action != XFRM_POLICY_ALLOW) {
2480 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2481 goto reject;
2482 }
2483 if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH) {
2484 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
2485 goto reject_error;
2486 }
2487 for (i = 0; i < pols[pi]->xfrm_nr; i++)
2488 tpp[ti++] = &pols[pi]->xfrm_vec[i];
2489 }
2490 xfrm_nr = ti;
2491 if (npols > 1) {
2492 xfrm_tmpl_sort(stp, tpp, xfrm_nr, family, net);
2493 tpp = stp;
2494 }
2495
2496 /* For each tunnel xfrm, find the first matching tmpl.
2497 * For each tmpl before that, find corresponding xfrm.
2498 * Order is _important_. Later we will implement
2499 * some barriers, but at the moment barriers
2500 * are implied between each two transformations.
2501 */
2502 for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
2503 k = xfrm_policy_ok(tpp[i], sp, k, family);
2504 if (k < 0) {
2505 if (k < -1)
2506 /* "-2 - errored_index" returned */
2507 xerr_idx = -(2+k);
2508 XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2509 goto reject;
2510 }
2511 }
2512
2513 if (secpath_has_nontransport(sp, k, &xerr_idx)) {
2514 XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2515 goto reject;
2516 }
2517
2518 xfrm_pols_put(pols, npols);
2519 return 1;
2520 }
2521 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2522
2523 reject:
2524 xfrm_secpath_reject(xerr_idx, skb, &fl);
2525 reject_error:
2526 xfrm_pols_put(pols, npols);
2527 return 0;
2528 }
2529 EXPORT_SYMBOL(__xfrm_policy_check);
2530
2531 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
2532 {
2533 struct net *net = dev_net(skb->dev);
2534 struct flowi fl;
2535 struct dst_entry *dst;
2536 int res = 1;
2537
2538 if (xfrm_decode_session(skb, &fl, family) < 0) {
2539 XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
2540 return 0;
2541 }
2542
2543 skb_dst_force(skb);
2544
2545 dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, XFRM_LOOKUP_QUEUE);
2546 if (IS_ERR(dst)) {
2547 res = 0;
2548 dst = NULL;
2549 }
2550 skb_dst_set(skb, dst);
2551 return res;
2552 }
2553 EXPORT_SYMBOL(__xfrm_route_forward);
2554
2555 /* Optimize later using cookies and generation ids. */
2556
2557 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
2558 {
2559 /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
2560 * to DST_OBSOLETE_FORCE_CHK to force all XFRM destinations to
2561 * get validated by dst_ops->check on every use. We do this
2562 * because when a normal route referenced by an XFRM dst is
2563 * obsoleted we do not go looking around for all parent
2564 * referencing XFRM dsts so that we can invalidate them. It
2565 * is just too much work. Instead we make the checks here on
2566 * every use. For example:
2567 *
2568 * XFRM dst A --> IPv4 dst X
2569 *
2570 * X is the "xdst->route" of A (X is also the "dst->path" of A
2571 * in this example). If X is marked obsolete, "A" will not
2572 * notice. That's what we are validating here via the
2573 * stale_bundle() check.
2574 *
2575 * When a dst is removed from the fib tree, DST_OBSOLETE_DEAD will
2576 * be marked on it.
2577 * This will force stale_bundle() to fail on any xdst bundle with
2578 * this dst linked in it.
2579 */
2580 if (dst->obsolete < 0 && !stale_bundle(dst))
2581 return dst;
2582
2583 return NULL;
2584 }
2585
2586 static int stale_bundle(struct dst_entry *dst)
2587 {
2588 return !xfrm_bundle_ok((struct xfrm_dst *)dst);
2589 }
2590
2591 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
2592 {
2593 while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
2594 dst->dev = dev_net(dev)->loopback_dev;
2595 dev_hold(dst->dev);
2596 dev_put(dev);
2597 }
2598 }
2599 EXPORT_SYMBOL(xfrm_dst_ifdown);
2600
2601 static void xfrm_link_failure(struct sk_buff *skb)
2602 {
2603 /* Impossible. Such dst must be popped before reaches point of failure. */
2604 }
2605
2606 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
2607 {
2608 if (dst) {
2609 if (dst->obsolete) {
2610 dst_release(dst);
2611 dst = NULL;
2612 }
2613 }
2614 return dst;
2615 }
2616
2617 static void xfrm_init_pmtu(struct dst_entry *dst)
2618 {
2619 do {
2620 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2621 u32 pmtu, route_mtu_cached;
2622
2623 pmtu = dst_mtu(dst->child);
2624 xdst->child_mtu_cached = pmtu;
2625
2626 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
2627
2628 route_mtu_cached = dst_mtu(xdst->route);
2629 xdst->route_mtu_cached = route_mtu_cached;
2630
2631 if (pmtu > route_mtu_cached)
2632 pmtu = route_mtu_cached;
2633
2634 dst_metric_set(dst, RTAX_MTU, pmtu);
2635 } while ((dst = dst->next));
2636 }
2637
2638 /* Check that the bundle accepts the flow and its components are
2639 * still valid.
2640 */
2641
2642 static int xfrm_bundle_ok(struct xfrm_dst *first)
2643 {
2644 struct dst_entry *dst = &first->u.dst;
2645 struct xfrm_dst *last;
2646 u32 mtu;
2647
2648 if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) ||
2649 (dst->dev && !netif_running(dst->dev)))
2650 return 0;
2651
2652 if (dst->flags & DST_XFRM_QUEUE)
2653 return 1;
2654
2655 last = NULL;
2656
2657 do {
2658 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2659
2660 if (dst->xfrm->km.state != XFRM_STATE_VALID)
2661 return 0;
2662 if (xdst->xfrm_genid != dst->xfrm->genid)
2663 return 0;
2664 if (xdst->num_pols > 0 &&
2665 xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
2666 return 0;
2667
2668 mtu = dst_mtu(dst->child);
2669 if (xdst->child_mtu_cached != mtu) {
2670 last = xdst;
2671 xdst->child_mtu_cached = mtu;
2672 }
2673
2674 if (!dst_check(xdst->route, xdst->route_cookie))
2675 return 0;
2676 mtu = dst_mtu(xdst->route);
2677 if (xdst->route_mtu_cached != mtu) {
2678 last = xdst;
2679 xdst->route_mtu_cached = mtu;
2680 }
2681
2682 dst = dst->child;
2683 } while (dst->xfrm);
2684
2685 if (likely(!last))
2686 return 1;
2687
2688 mtu = last->child_mtu_cached;
2689 for (;;) {
2690 dst = &last->u.dst;
2691
2692 mtu = xfrm_state_mtu(dst->xfrm, mtu);
2693 if (mtu > last->route_mtu_cached)
2694 mtu = last->route_mtu_cached;
2695 dst_metric_set(dst, RTAX_MTU, mtu);
2696
2697 if (last == first)
2698 break;
2699
2700 last = (struct xfrm_dst *)last->u.dst.next;
2701 last->child_mtu_cached = mtu;
2702 }
2703
2704 return 1;
2705 }
2706
2707 static unsigned int xfrm_default_advmss(const struct dst_entry *dst)
2708 {
2709 return dst_metric_advmss(dst->path);
2710 }
2711
2712 static unsigned int xfrm_mtu(const struct dst_entry *dst)
2713 {
2714 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2715
2716 return mtu ? : dst_mtu(dst->path);
2717 }
2718
2719 static const void *xfrm_get_dst_nexthop(const struct dst_entry *dst,
2720 const void *daddr)
2721 {
2722 const struct dst_entry *path = dst->path;
2723
2724 for (; dst != path; dst = dst->child) {
2725 const struct xfrm_state *xfrm = dst->xfrm;
2726
2727 if (xfrm->props.mode == XFRM_MODE_TRANSPORT)
2728 continue;
2729 if (xfrm->type->flags & XFRM_TYPE_REMOTE_COADDR)
2730 daddr = xfrm->coaddr;
2731 else if (!(xfrm->type->flags & XFRM_TYPE_LOCAL_COADDR))
2732 daddr = &xfrm->id.daddr;
2733 }
2734 return daddr;
2735 }
2736
2737 static struct neighbour *xfrm_neigh_lookup(const struct dst_entry *dst,
2738 struct sk_buff *skb,
2739 const void *daddr)
2740 {
2741 const struct dst_entry *path = dst->path;
2742
2743 if (!skb)
2744 daddr = xfrm_get_dst_nexthop(dst, daddr);
2745 return path->ops->neigh_lookup(path, skb, daddr);
2746 }
2747
2748 static void xfrm_confirm_neigh(const struct dst_entry *dst, const void *daddr)
2749 {
2750 const struct dst_entry *path = dst->path;
2751
2752 daddr = xfrm_get_dst_nexthop(dst, daddr);
2753 path->ops->confirm_neigh(path, daddr);
2754 }
2755
2756 int xfrm_policy_register_afinfo(const struct xfrm_policy_afinfo *afinfo, int family)
2757 {
2758 int err = 0;
2759
2760 if (WARN_ON(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
2761 return -EAFNOSUPPORT;
2762
2763 spin_lock(&xfrm_policy_afinfo_lock);
2764 if (unlikely(xfrm_policy_afinfo[family] != NULL))
2765 err = -EEXIST;
2766 else {
2767 struct dst_ops *dst_ops = afinfo->dst_ops;
2768 if (likely(dst_ops->kmem_cachep == NULL))
2769 dst_ops->kmem_cachep = xfrm_dst_cache;
2770 if (likely(dst_ops->check == NULL))
2771 dst_ops->check = xfrm_dst_check;
2772 if (likely(dst_ops->default_advmss == NULL))
2773 dst_ops->default_advmss = xfrm_default_advmss;
2774 if (likely(dst_ops->mtu == NULL))
2775 dst_ops->mtu = xfrm_mtu;
2776 if (likely(dst_ops->negative_advice == NULL))
2777 dst_ops->negative_advice = xfrm_negative_advice;
2778 if (likely(dst_ops->link_failure == NULL))
2779 dst_ops->link_failure = xfrm_link_failure;
2780 if (likely(dst_ops->neigh_lookup == NULL))
2781 dst_ops->neigh_lookup = xfrm_neigh_lookup;
2782 if (likely(!dst_ops->confirm_neigh))
2783 dst_ops->confirm_neigh = xfrm_confirm_neigh;
2784 rcu_assign_pointer(xfrm_policy_afinfo[family], afinfo);
2785 }
2786 spin_unlock(&xfrm_policy_afinfo_lock);
2787
2788 return err;
2789 }
2790 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
2791
2792 void xfrm_policy_unregister_afinfo(const struct xfrm_policy_afinfo *afinfo)
2793 {
2794 struct dst_ops *dst_ops = afinfo->dst_ops;
2795 int i;
2796
2797 for (i = 0; i < ARRAY_SIZE(xfrm_policy_afinfo); i++) {
2798 if (xfrm_policy_afinfo[i] != afinfo)
2799 continue;
2800 RCU_INIT_POINTER(xfrm_policy_afinfo[i], NULL);
2801 break;
2802 }
2803
2804 synchronize_rcu();
2805
2806 dst_ops->kmem_cachep = NULL;
2807 dst_ops->check = NULL;
2808 dst_ops->negative_advice = NULL;
2809 dst_ops->link_failure = NULL;
2810 }
2811 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
2812
2813 #ifdef CONFIG_XFRM_STATISTICS
2814 static int __net_init xfrm_statistics_init(struct net *net)
2815 {
2816 int rv;
2817 net->mib.xfrm_statistics = alloc_percpu(struct linux_xfrm_mib);
2818 if (!net->mib.xfrm_statistics)
2819 return -ENOMEM;
2820 rv = xfrm_proc_init(net);
2821 if (rv < 0)
2822 free_percpu(net->mib.xfrm_statistics);
2823 return rv;
2824 }
2825
2826 static void xfrm_statistics_fini(struct net *net)
2827 {
2828 xfrm_proc_fini(net);
2829 free_percpu(net->mib.xfrm_statistics);
2830 }
2831 #else
2832 static int __net_init xfrm_statistics_init(struct net *net)
2833 {
2834 return 0;
2835 }
2836
2837 static void xfrm_statistics_fini(struct net *net)
2838 {
2839 }
2840 #endif
2841
2842 static int __net_init xfrm_policy_init(struct net *net)
2843 {
2844 unsigned int hmask, sz;
2845 int dir;
2846
2847 if (net_eq(net, &init_net))
2848 xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
2849 sizeof(struct xfrm_dst),
2850 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
2851 NULL);
2852
2853 hmask = 8 - 1;
2854 sz = (hmask+1) * sizeof(struct hlist_head);
2855
2856 net->xfrm.policy_byidx = xfrm_hash_alloc(sz);
2857 if (!net->xfrm.policy_byidx)
2858 goto out_byidx;
2859 net->xfrm.policy_idx_hmask = hmask;
2860
2861 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
2862 struct xfrm_policy_hash *htab;
2863
2864 net->xfrm.policy_count[dir] = 0;
2865 net->xfrm.policy_count[XFRM_POLICY_MAX + dir] = 0;
2866 INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
2867
2868 htab = &net->xfrm.policy_bydst[dir];
2869 htab->table = xfrm_hash_alloc(sz);
2870 if (!htab->table)
2871 goto out_bydst;
2872 htab->hmask = hmask;
2873 htab->dbits4 = 32;
2874 htab->sbits4 = 32;
2875 htab->dbits6 = 128;
2876 htab->sbits6 = 128;
2877 }
2878 net->xfrm.policy_hthresh.lbits4 = 32;
2879 net->xfrm.policy_hthresh.rbits4 = 32;
2880 net->xfrm.policy_hthresh.lbits6 = 128;
2881 net->xfrm.policy_hthresh.rbits6 = 128;
2882
2883 seqlock_init(&net->xfrm.policy_hthresh.lock);
2884
2885 INIT_LIST_HEAD(&net->xfrm.policy_all);
2886 INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
2887 INIT_WORK(&net->xfrm.policy_hthresh.work, xfrm_hash_rebuild);
2888 if (net_eq(net, &init_net))
2889 xfrm_dev_init();
2890 return 0;
2891
2892 out_bydst:
2893 for (dir--; dir >= 0; dir--) {
2894 struct xfrm_policy_hash *htab;
2895
2896 htab = &net->xfrm.policy_bydst[dir];
2897 xfrm_hash_free(htab->table, sz);
2898 }
2899 xfrm_hash_free(net->xfrm.policy_byidx, sz);
2900 out_byidx:
2901 return -ENOMEM;
2902 }
2903
2904 static void xfrm_policy_fini(struct net *net)
2905 {
2906 unsigned int sz;
2907 int dir;
2908
2909 flush_work(&net->xfrm.policy_hash_work);
2910 #ifdef CONFIG_XFRM_SUB_POLICY
2911 xfrm_policy_flush(net, XFRM_POLICY_TYPE_SUB, false);
2912 #endif
2913 xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, false);
2914
2915 WARN_ON(!list_empty(&net->xfrm.policy_all));
2916
2917 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
2918 struct xfrm_policy_hash *htab;
2919
2920 WARN_ON(!hlist_empty(&net->xfrm.policy_inexact[dir]));
2921
2922 htab = &net->xfrm.policy_bydst[dir];
2923 sz = (htab->hmask + 1) * sizeof(struct hlist_head);
2924 WARN_ON(!hlist_empty(htab->table));
2925 xfrm_hash_free(htab->table, sz);
2926 }
2927
2928 sz = (net->xfrm.policy_idx_hmask + 1) * sizeof(struct hlist_head);
2929 WARN_ON(!hlist_empty(net->xfrm.policy_byidx));
2930 xfrm_hash_free(net->xfrm.policy_byidx, sz);
2931 }
2932
2933 static int __net_init xfrm_net_init(struct net *net)
2934 {
2935 int rv;
2936
2937 /* Initialize the per-net locks here */
2938 spin_lock_init(&net->xfrm.xfrm_state_lock);
2939 spin_lock_init(&net->xfrm.xfrm_policy_lock);
2940 mutex_init(&net->xfrm.xfrm_cfg_mutex);
2941
2942 rv = xfrm_statistics_init(net);
2943 if (rv < 0)
2944 goto out_statistics;
2945 rv = xfrm_state_init(net);
2946 if (rv < 0)
2947 goto out_state;
2948 rv = xfrm_policy_init(net);
2949 if (rv < 0)
2950 goto out_policy;
2951 rv = xfrm_sysctl_init(net);
2952 if (rv < 0)
2953 goto out_sysctl;
2954
2955 return 0;
2956
2957 out_sysctl:
2958 xfrm_policy_fini(net);
2959 out_policy:
2960 xfrm_state_fini(net);
2961 out_state:
2962 xfrm_statistics_fini(net);
2963 out_statistics:
2964 return rv;
2965 }
2966
2967 static void __net_exit xfrm_net_exit(struct net *net)
2968 {
2969 xfrm_sysctl_fini(net);
2970 xfrm_policy_fini(net);
2971 xfrm_state_fini(net);
2972 xfrm_statistics_fini(net);
2973 }
2974
2975 static struct pernet_operations __net_initdata xfrm_net_ops = {
2976 .init = xfrm_net_init,
2977 .exit = xfrm_net_exit,
2978 };
2979
2980 void __init xfrm_init(void)
2981 {
2982 int i;
2983
2984 xfrm_pcpu_work = kmalloc_array(NR_CPUS, sizeof(*xfrm_pcpu_work),
2985 GFP_KERNEL);
2986 BUG_ON(!xfrm_pcpu_work);
2987
2988 for (i = 0; i < NR_CPUS; i++)
2989 INIT_WORK(&xfrm_pcpu_work[i], xfrm_pcpu_work_fn);
2990
2991 register_pernet_subsys(&xfrm_net_ops);
2992 seqcount_init(&xfrm_policy_hash_generation);
2993 xfrm_input_init();
2994 }
2995
2996 #ifdef CONFIG_AUDITSYSCALL
2997 static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
2998 struct audit_buffer *audit_buf)
2999 {
3000 struct xfrm_sec_ctx *ctx = xp->security;
3001 struct xfrm_selector *sel = &xp->selector;
3002
3003 if (ctx)
3004 audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
3005 ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str);
3006
3007 switch (sel->family) {
3008 case AF_INET:
3009 audit_log_format(audit_buf, " src=%pI4", &sel->saddr.a4);
3010 if (sel->prefixlen_s != 32)
3011 audit_log_format(audit_buf, " src_prefixlen=%d",
3012 sel->prefixlen_s);
3013 audit_log_format(audit_buf, " dst=%pI4", &sel->daddr.a4);
3014 if (sel->prefixlen_d != 32)
3015 audit_log_format(audit_buf, " dst_prefixlen=%d",
3016 sel->prefixlen_d);
3017 break;
3018 case AF_INET6:
3019 audit_log_format(audit_buf, " src=%pI6", sel->saddr.a6);
3020 if (sel->prefixlen_s != 128)
3021 audit_log_format(audit_buf, " src_prefixlen=%d",
3022 sel->prefixlen_s);
3023 audit_log_format(audit_buf, " dst=%pI6", sel->daddr.a6);
3024 if (sel->prefixlen_d != 128)
3025 audit_log_format(audit_buf, " dst_prefixlen=%d",
3026 sel->prefixlen_d);
3027 break;
3028 }
3029 }
3030
3031 void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid)
3032 {
3033 struct audit_buffer *audit_buf;
3034
3035 audit_buf = xfrm_audit_start("SPD-add");
3036 if (audit_buf == NULL)
3037 return;
3038 xfrm_audit_helper_usrinfo(task_valid, audit_buf);
3039 audit_log_format(audit_buf, " res=%u", result);
3040 xfrm_audit_common_policyinfo(xp, audit_buf);
3041 audit_log_end(audit_buf);
3042 }
3043 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
3044
3045 void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
3046 bool task_valid)
3047 {
3048 struct audit_buffer *audit_buf;
3049
3050 audit_buf = xfrm_audit_start("SPD-delete");
3051 if (audit_buf == NULL)
3052 return;
3053 xfrm_audit_helper_usrinfo(task_valid, audit_buf);
3054 audit_log_format(audit_buf, " res=%u", result);
3055 xfrm_audit_common_policyinfo(xp, audit_buf);
3056 audit_log_end(audit_buf);
3057 }
3058 EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
3059 #endif
3060
3061 #ifdef CONFIG_XFRM_MIGRATE
3062 static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp,
3063 const struct xfrm_selector *sel_tgt)
3064 {
3065 if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
3066 if (sel_tgt->family == sel_cmp->family &&
3067 xfrm_addr_equal(&sel_tgt->daddr, &sel_cmp->daddr,
3068 sel_cmp->family) &&
3069 xfrm_addr_equal(&sel_tgt->saddr, &sel_cmp->saddr,
3070 sel_cmp->family) &&
3071 sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
3072 sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
3073 return true;
3074 }
3075 } else {
3076 if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
3077 return true;
3078 }
3079 }
3080 return false;
3081 }
3082
3083 static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector *sel,
3084 u8 dir, u8 type, struct net *net)
3085 {
3086 struct xfrm_policy *pol, *ret = NULL;
3087 struct hlist_head *chain;
3088 u32 priority = ~0U;
3089
3090 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
3091 chain = policy_hash_direct(net, &sel->daddr, &sel->saddr, sel->family, dir);
3092 hlist_for_each_entry(pol, chain, bydst) {
3093 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
3094 pol->type == type) {
3095 ret = pol;
3096 priority = ret->priority;
3097 break;
3098 }
3099 }
3100 chain = &net->xfrm.policy_inexact[dir];
3101 hlist_for_each_entry(pol, chain, bydst) {
3102 if ((pol->priority >= priority) && ret)
3103 break;
3104
3105 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
3106 pol->type == type) {
3107 ret = pol;
3108 break;
3109 }
3110 }
3111
3112 xfrm_pol_hold(ret);
3113
3114 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
3115
3116 return ret;
3117 }
3118
3119 static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t)
3120 {
3121 int match = 0;
3122
3123 if (t->mode == m->mode && t->id.proto == m->proto &&
3124 (m->reqid == 0 || t->reqid == m->reqid)) {
3125 switch (t->mode) {
3126 case XFRM_MODE_TUNNEL:
3127 case XFRM_MODE_BEET:
3128 if (xfrm_addr_equal(&t->id.daddr, &m->old_daddr,
3129 m->old_family) &&
3130 xfrm_addr_equal(&t->saddr, &m->old_saddr,
3131 m->old_family)) {
3132 match = 1;
3133 }
3134 break;
3135 case XFRM_MODE_TRANSPORT:
3136 /* in case of transport mode, template does not store
3137 any IP addresses, hence we just compare mode and
3138 protocol */
3139 match = 1;
3140 break;
3141 default:
3142 break;
3143 }
3144 }
3145 return match;
3146 }
3147
3148 /* update endpoint address(es) of template(s) */
3149 static int xfrm_policy_migrate(struct xfrm_policy *pol,
3150 struct xfrm_migrate *m, int num_migrate)
3151 {
3152 struct xfrm_migrate *mp;
3153 int i, j, n = 0;
3154
3155 write_lock_bh(&pol->lock);
3156 if (unlikely(pol->walk.dead)) {
3157 /* target policy has been deleted */
3158 write_unlock_bh(&pol->lock);
3159 return -ENOENT;
3160 }
3161
3162 for (i = 0; i < pol->xfrm_nr; i++) {
3163 for (j = 0, mp = m; j < num_migrate; j++, mp++) {
3164 if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
3165 continue;
3166 n++;
3167 if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
3168 pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
3169 continue;
3170 /* update endpoints */
3171 memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
3172 sizeof(pol->xfrm_vec[i].id.daddr));
3173 memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
3174 sizeof(pol->xfrm_vec[i].saddr));
3175 pol->xfrm_vec[i].encap_family = mp->new_family;
3176 /* flush bundles */
3177 atomic_inc(&pol->genid);
3178 }
3179 }
3180
3181 write_unlock_bh(&pol->lock);
3182
3183 if (!n)
3184 return -ENODATA;
3185
3186 return 0;
3187 }
3188
3189 static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate)
3190 {
3191 int i, j;
3192
3193 if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
3194 return -EINVAL;
3195
3196 for (i = 0; i < num_migrate; i++) {
3197 if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
3198 xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
3199 return -EINVAL;
3200
3201 /* check if there is any duplicated entry */
3202 for (j = i + 1; j < num_migrate; j++) {
3203 if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
3204 sizeof(m[i].old_daddr)) &&
3205 !memcmp(&m[i].old_saddr, &m[j].old_saddr,
3206 sizeof(m[i].old_saddr)) &&
3207 m[i].proto == m[j].proto &&
3208 m[i].mode == m[j].mode &&
3209 m[i].reqid == m[j].reqid &&
3210 m[i].old_family == m[j].old_family)
3211 return -EINVAL;
3212 }
3213 }
3214
3215 return 0;
3216 }
3217
3218 int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
3219 struct xfrm_migrate *m, int num_migrate,
3220 struct xfrm_kmaddress *k, struct net *net,
3221 struct xfrm_encap_tmpl *encap)
3222 {
3223 int i, err, nx_cur = 0, nx_new = 0;
3224 struct xfrm_policy *pol = NULL;
3225 struct xfrm_state *x, *xc;
3226 struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
3227 struct xfrm_state *x_new[XFRM_MAX_DEPTH];
3228 struct xfrm_migrate *mp;
3229
3230 /* Stage 0 - sanity checks */
3231 if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
3232 goto out;
3233
3234 if (dir >= XFRM_POLICY_MAX) {
3235 err = -EINVAL;
3236 goto out;
3237 }
3238
3239 /* Stage 1 - find policy */
3240 if ((pol = xfrm_migrate_policy_find(sel, dir, type, net)) == NULL) {
3241 err = -ENOENT;
3242 goto out;
3243 }
3244
3245 /* Stage 2 - find and update state(s) */
3246 for (i = 0, mp = m; i < num_migrate; i++, mp++) {
3247 if ((x = xfrm_migrate_state_find(mp, net))) {
3248 x_cur[nx_cur] = x;
3249 nx_cur++;
3250 xc = xfrm_state_migrate(x, mp, encap);
3251 if (xc) {
3252 x_new[nx_new] = xc;
3253 nx_new++;
3254 } else {
3255 err = -ENODATA;
3256 goto restore_state;
3257 }
3258 }
3259 }
3260
3261 /* Stage 3 - update policy */
3262 if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
3263 goto restore_state;
3264
3265 /* Stage 4 - delete old state(s) */
3266 if (nx_cur) {
3267 xfrm_states_put(x_cur, nx_cur);
3268 xfrm_states_delete(x_cur, nx_cur);
3269 }
3270
3271 /* Stage 5 - announce */
3272 km_migrate(sel, dir, type, m, num_migrate, k, encap);
3273
3274 xfrm_pol_put(pol);
3275
3276 return 0;
3277 out:
3278 return err;
3279
3280 restore_state:
3281 if (pol)
3282 xfrm_pol_put(pol);
3283 if (nx_cur)
3284 xfrm_states_put(x_cur, nx_cur);
3285 if (nx_new)
3286 xfrm_states_delete(x_new, nx_new);
3287
3288 return err;
3289 }
3290 EXPORT_SYMBOL(xfrm_migrate);
3291 #endif
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