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[ARM] Support register switch in nommu mode
[linux-2.6/verdex.git] / net / xfrm / xfrm_policy.c
blob077bbf9fb9b7605f08af1de583141bbea0429be0
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 <asm/bug.h>
17 #include <linux/config.h>
18 #include <linux/slab.h>
19 #include <linux/kmod.h>
20 #include <linux/list.h>
21 #include <linux/spinlock.h>
22 #include <linux/workqueue.h>
23 #include <linux/notifier.h>
24 #include <linux/netdevice.h>
25 #include <linux/netfilter.h>
26 #include <linux/module.h>
27 #include <net/xfrm.h>
28 #include <net/ip.h>
29
30 DECLARE_MUTEX(xfrm_cfg_sem);
31 EXPORT_SYMBOL(xfrm_cfg_sem);
32
33 static DEFINE_RWLOCK(xfrm_policy_lock);
34
35 struct xfrm_policy *xfrm_policy_list[XFRM_POLICY_MAX*2];
36 EXPORT_SYMBOL(xfrm_policy_list);
37
38 static DEFINE_RWLOCK(xfrm_policy_afinfo_lock);
39 static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO];
40
41 static kmem_cache_t *xfrm_dst_cache __read_mostly;
42
43 static struct work_struct xfrm_policy_gc_work;
44 static struct list_head xfrm_policy_gc_list =
45 LIST_HEAD_INIT(xfrm_policy_gc_list);
46 static DEFINE_SPINLOCK(xfrm_policy_gc_lock);
47
48 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family);
49 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);
50
51 int xfrm_register_type(struct xfrm_type *type, unsigned short family)
52 {
53 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
54 struct xfrm_type_map *typemap;
55 int err = 0;
56
57 if (unlikely(afinfo == NULL))
58 return -EAFNOSUPPORT;
59 typemap = afinfo->type_map;
60
61 write_lock(&typemap->lock);
62 if (likely(typemap->map[type->proto] == NULL))
63 typemap->map[type->proto] = type;
64 else
65 err = -EEXIST;
66 write_unlock(&typemap->lock);
67 xfrm_policy_put_afinfo(afinfo);
68 return err;
69 }
70 EXPORT_SYMBOL(xfrm_register_type);
71
72 int xfrm_unregister_type(struct xfrm_type *type, unsigned short family)
73 {
74 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
75 struct xfrm_type_map *typemap;
76 int err = 0;
77
78 if (unlikely(afinfo == NULL))
79 return -EAFNOSUPPORT;
80 typemap = afinfo->type_map;
81
82 write_lock(&typemap->lock);
83 if (unlikely(typemap->map[type->proto] != type))
84 err = -ENOENT;
85 else
86 typemap->map[type->proto] = NULL;
87 write_unlock(&typemap->lock);
88 xfrm_policy_put_afinfo(afinfo);
89 return err;
90 }
91 EXPORT_SYMBOL(xfrm_unregister_type);
92
93 struct xfrm_type *xfrm_get_type(u8 proto, unsigned short family)
94 {
95 struct xfrm_policy_afinfo *afinfo;
96 struct xfrm_type_map *typemap;
97 struct xfrm_type *type;
98 int modload_attempted = 0;
99
100 retry:
101 afinfo = xfrm_policy_get_afinfo(family);
102 if (unlikely(afinfo == NULL))
103 return NULL;
104 typemap = afinfo->type_map;
105
106 read_lock(&typemap->lock);
107 type = typemap->map[proto];
108 if (unlikely(type && !try_module_get(type->owner)))
109 type = NULL;
110 read_unlock(&typemap->lock);
111 if (!type && !modload_attempted) {
112 xfrm_policy_put_afinfo(afinfo);
113 request_module("xfrm-type-%d-%d",
114 (int) family, (int) proto);
115 modload_attempted = 1;
116 goto retry;
117 }
118
119 xfrm_policy_put_afinfo(afinfo);
120 return type;
121 }
122
123 int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl,
124 unsigned short family)
125 {
126 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
127 int err = 0;
128
129 if (unlikely(afinfo == NULL))
130 return -EAFNOSUPPORT;
131
132 if (likely(afinfo->dst_lookup != NULL))
133 err = afinfo->dst_lookup(dst, fl);
134 else
135 err = -EINVAL;
136 xfrm_policy_put_afinfo(afinfo);
137 return err;
138 }
139 EXPORT_SYMBOL(xfrm_dst_lookup);
140
141 void xfrm_put_type(struct xfrm_type *type)
142 {
143 module_put(type->owner);
144 }
145
146 static inline unsigned long make_jiffies(long secs)
147 {
148 if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
149 return MAX_SCHEDULE_TIMEOUT-1;
150 else
151 return secs*HZ;
152 }
153
154 static void xfrm_policy_timer(unsigned long data)
155 {
156 struct xfrm_policy *xp = (struct xfrm_policy*)data;
157 unsigned long now = (unsigned long)xtime.tv_sec;
158 long next = LONG_MAX;
159 int warn = 0;
160 int dir;
161
162 read_lock(&xp->lock);
163
164 if (xp->dead)
165 goto out;
166
167 dir = xfrm_policy_id2dir(xp->index);
168
169 if (xp->lft.hard_add_expires_seconds) {
170 long tmo = xp->lft.hard_add_expires_seconds +
171 xp->curlft.add_time - now;
172 if (tmo <= 0)
173 goto expired;
174 if (tmo < next)
175 next = tmo;
176 }
177 if (xp->lft.hard_use_expires_seconds) {
178 long tmo = xp->lft.hard_use_expires_seconds +
179 (xp->curlft.use_time ? : xp->curlft.add_time) - now;
180 if (tmo <= 0)
181 goto expired;
182 if (tmo < next)
183 next = tmo;
184 }
185 if (xp->lft.soft_add_expires_seconds) {
186 long tmo = xp->lft.soft_add_expires_seconds +
187 xp->curlft.add_time - now;
188 if (tmo <= 0) {
189 warn = 1;
190 tmo = XFRM_KM_TIMEOUT;
191 }
192 if (tmo < next)
193 next = tmo;
194 }
195 if (xp->lft.soft_use_expires_seconds) {
196 long tmo = xp->lft.soft_use_expires_seconds +
197 (xp->curlft.use_time ? : xp->curlft.add_time) - now;
198 if (tmo <= 0) {
199 warn = 1;
200 tmo = XFRM_KM_TIMEOUT;
201 }
202 if (tmo < next)
203 next = tmo;
204 }
205
206 if (warn)
207 km_policy_expired(xp, dir, 0);
208 if (next != LONG_MAX &&
209 !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
210 xfrm_pol_hold(xp);
211
212 out:
213 read_unlock(&xp->lock);
214 xfrm_pol_put(xp);
215 return;
216
217 expired:
218 read_unlock(&xp->lock);
219 if (!xfrm_policy_delete(xp, dir))
220 km_policy_expired(xp, dir, 1);
221 xfrm_pol_put(xp);
222 }
223
224
225 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
226 * SPD calls.
227 */
228
229 struct xfrm_policy *xfrm_policy_alloc(gfp_t gfp)
230 {
231 struct xfrm_policy *policy;
232
233 policy = kmalloc(sizeof(struct xfrm_policy), gfp);
234
235 if (policy) {
236 memset(policy, 0, sizeof(struct xfrm_policy));
237 atomic_set(&policy->refcnt, 1);
238 rwlock_init(&policy->lock);
239 init_timer(&policy->timer);
240 policy->timer.data = (unsigned long)policy;
241 policy->timer.function = xfrm_policy_timer;
242 }
243 return policy;
244 }
245 EXPORT_SYMBOL(xfrm_policy_alloc);
246
247 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
248
249 void __xfrm_policy_destroy(struct xfrm_policy *policy)
250 {
251 BUG_ON(!policy->dead);
252
253 BUG_ON(policy->bundles);
254
255 if (del_timer(&policy->timer))
256 BUG();
257
258 security_xfrm_policy_free(policy);
259 kfree(policy);
260 }
261 EXPORT_SYMBOL(__xfrm_policy_destroy);
262
263 static void xfrm_policy_gc_kill(struct xfrm_policy *policy)
264 {
265 struct dst_entry *dst;
266
267 while ((dst = policy->bundles) != NULL) {
268 policy->bundles = dst->next;
269 dst_free(dst);
270 }
271
272 if (del_timer(&policy->timer))
273 atomic_dec(&policy->refcnt);
274
275 if (atomic_read(&policy->refcnt) > 1)
276 flow_cache_flush();
277
278 xfrm_pol_put(policy);
279 }
280
281 static void xfrm_policy_gc_task(void *data)
282 {
283 struct xfrm_policy *policy;
284 struct list_head *entry, *tmp;
285 struct list_head gc_list = LIST_HEAD_INIT(gc_list);
286
287 spin_lock_bh(&xfrm_policy_gc_lock);
288 list_splice_init(&xfrm_policy_gc_list, &gc_list);
289 spin_unlock_bh(&xfrm_policy_gc_lock);
290
291 list_for_each_safe(entry, tmp, &gc_list) {
292 policy = list_entry(entry, struct xfrm_policy, list);
293 xfrm_policy_gc_kill(policy);
294 }
295 }
296
297 /* Rule must be locked. Release descentant resources, announce
298 * entry dead. The rule must be unlinked from lists to the moment.
299 */
300
301 static void xfrm_policy_kill(struct xfrm_policy *policy)
302 {
303 int dead;
304
305 write_lock_bh(&policy->lock);
306 dead = policy->dead;
307 policy->dead = 1;
308 write_unlock_bh(&policy->lock);
309
310 if (unlikely(dead)) {
311 WARN_ON(1);
312 return;
313 }
314
315 spin_lock(&xfrm_policy_gc_lock);
316 list_add(&policy->list, &xfrm_policy_gc_list);
317 spin_unlock(&xfrm_policy_gc_lock);
318
319 schedule_work(&xfrm_policy_gc_work);
320 }
321
322 /* Generate new index... KAME seems to generate them ordered by cost
323 * of an absolute inpredictability of ordering of rules. This will not pass. */
324 static u32 xfrm_gen_index(int dir)
325 {
326 u32 idx;
327 struct xfrm_policy *p;
328 static u32 idx_generator;
329
330 for (;;) {
331 idx = (idx_generator | dir);
332 idx_generator += 8;
333 if (idx == 0)
334 idx = 8;
335 for (p = xfrm_policy_list[dir]; p; p = p->next) {
336 if (p->index == idx)
337 break;
338 }
339 if (!p)
340 return idx;
341 }
342 }
343
344 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
345 {
346 struct xfrm_policy *pol, **p;
347 struct xfrm_policy *delpol = NULL;
348 struct xfrm_policy **newpos = NULL;
349 struct dst_entry *gc_list;
350
351 write_lock_bh(&xfrm_policy_lock);
352 for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL;) {
353 if (!delpol && memcmp(&policy->selector, &pol->selector, sizeof(pol->selector)) == 0 &&
354 xfrm_sec_ctx_match(pol->security, policy->security)) {
355 if (excl) {
356 write_unlock_bh(&xfrm_policy_lock);
357 return -EEXIST;
358 }
359 *p = pol->next;
360 delpol = pol;
361 if (policy->priority > pol->priority)
362 continue;
363 } else if (policy->priority >= pol->priority) {
364 p = &pol->next;
365 continue;
366 }
367 if (!newpos)
368 newpos = p;
369 if (delpol)
370 break;
371 p = &pol->next;
372 }
373 if (newpos)
374 p = newpos;
375 xfrm_pol_hold(policy);
376 policy->next = *p;
377 *p = policy;
378 atomic_inc(&flow_cache_genid);
379 policy->index = delpol ? delpol->index : xfrm_gen_index(dir);
380 policy->curlft.add_time = (unsigned long)xtime.tv_sec;
381 policy->curlft.use_time = 0;
382 if (!mod_timer(&policy->timer, jiffies + HZ))
383 xfrm_pol_hold(policy);
384 write_unlock_bh(&xfrm_policy_lock);
385
386 if (delpol)
387 xfrm_policy_kill(delpol);
388
389 read_lock_bh(&xfrm_policy_lock);
390 gc_list = NULL;
391 for (policy = policy->next; policy; policy = policy->next) {
392 struct dst_entry *dst;
393
394 write_lock(&policy->lock);
395 dst = policy->bundles;
396 if (dst) {
397 struct dst_entry *tail = dst;
398 while (tail->next)
399 tail = tail->next;
400 tail->next = gc_list;
401 gc_list = dst;
402
403 policy->bundles = NULL;
404 }
405 write_unlock(&policy->lock);
406 }
407 read_unlock_bh(&xfrm_policy_lock);
408
409 while (gc_list) {
410 struct dst_entry *dst = gc_list;
411
412 gc_list = dst->next;
413 dst_free(dst);
414 }
415
416 return 0;
417 }
418 EXPORT_SYMBOL(xfrm_policy_insert);
419
420 struct xfrm_policy *xfrm_policy_bysel_ctx(int dir, struct xfrm_selector *sel,
421 struct xfrm_sec_ctx *ctx, int delete)
422 {
423 struct xfrm_policy *pol, **p;
424
425 write_lock_bh(&xfrm_policy_lock);
426 for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL; p = &pol->next) {
427 if ((memcmp(sel, &pol->selector, sizeof(*sel)) == 0) &&
428 (xfrm_sec_ctx_match(ctx, pol->security))) {
429 xfrm_pol_hold(pol);
430 if (delete)
431 *p = pol->next;
432 break;
433 }
434 }
435 write_unlock_bh(&xfrm_policy_lock);
436
437 if (pol && delete) {
438 atomic_inc(&flow_cache_genid);
439 xfrm_policy_kill(pol);
440 }
441 return pol;
442 }
443 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
444
445 struct xfrm_policy *xfrm_policy_byid(int dir, u32 id, int delete)
446 {
447 struct xfrm_policy *pol, **p;
448
449 write_lock_bh(&xfrm_policy_lock);
450 for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL; p = &pol->next) {
451 if (pol->index == id) {
452 xfrm_pol_hold(pol);
453 if (delete)
454 *p = pol->next;
455 break;
456 }
457 }
458 write_unlock_bh(&xfrm_policy_lock);
459
460 if (pol && delete) {
461 atomic_inc(&flow_cache_genid);
462 xfrm_policy_kill(pol);
463 }
464 return pol;
465 }
466 EXPORT_SYMBOL(xfrm_policy_byid);
467
468 void xfrm_policy_flush(void)
469 {
470 struct xfrm_policy *xp;
471 int dir;
472
473 write_lock_bh(&xfrm_policy_lock);
474 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
475 while ((xp = xfrm_policy_list[dir]) != NULL) {
476 xfrm_policy_list[dir] = xp->next;
477 write_unlock_bh(&xfrm_policy_lock);
478
479 xfrm_policy_kill(xp);
480
481 write_lock_bh(&xfrm_policy_lock);
482 }
483 }
484 atomic_inc(&flow_cache_genid);
485 write_unlock_bh(&xfrm_policy_lock);
486 }
487 EXPORT_SYMBOL(xfrm_policy_flush);
488
489 int xfrm_policy_walk(int (*func)(struct xfrm_policy *, int, int, void*),
490 void *data)
491 {
492 struct xfrm_policy *xp;
493 int dir;
494 int count = 0;
495 int error = 0;
496
497 read_lock_bh(&xfrm_policy_lock);
498 for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
499 for (xp = xfrm_policy_list[dir]; xp; xp = xp->next)
500 count++;
501 }
502
503 if (count == 0) {
504 error = -ENOENT;
505 goto out;
506 }
507
508 for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
509 for (xp = xfrm_policy_list[dir]; xp; xp = xp->next) {
510 error = func(xp, dir%XFRM_POLICY_MAX, --count, data);
511 if (error)
512 goto out;
513 }
514 }
515
516 out:
517 read_unlock_bh(&xfrm_policy_lock);
518 return error;
519 }
520 EXPORT_SYMBOL(xfrm_policy_walk);
521
522 /* Find policy to apply to this flow. */
523
524 static void xfrm_policy_lookup(struct flowi *fl, u32 sk_sid, u16 family, u8 dir,
525 void **objp, atomic_t **obj_refp)
526 {
527 struct xfrm_policy *pol;
528
529 read_lock_bh(&xfrm_policy_lock);
530 for (pol = xfrm_policy_list[dir]; pol; pol = pol->next) {
531 struct xfrm_selector *sel = &pol->selector;
532 int match;
533
534 if (pol->family != family)
535 continue;
536
537 match = xfrm_selector_match(sel, fl, family);
538
539 if (match) {
540 if (!security_xfrm_policy_lookup(pol, sk_sid, dir)) {
541 xfrm_pol_hold(pol);
542 break;
543 }
544 }
545 }
546 read_unlock_bh(&xfrm_policy_lock);
547 if ((*objp = (void *) pol) != NULL)
548 *obj_refp = &pol->refcnt;
549 }
550
551 static inline int policy_to_flow_dir(int dir)
552 {
553 if (XFRM_POLICY_IN == FLOW_DIR_IN &&
554 XFRM_POLICY_OUT == FLOW_DIR_OUT &&
555 XFRM_POLICY_FWD == FLOW_DIR_FWD)
556 return dir;
557 switch (dir) {
558 default:
559 case XFRM_POLICY_IN:
560 return FLOW_DIR_IN;
561 case XFRM_POLICY_OUT:
562 return FLOW_DIR_OUT;
563 case XFRM_POLICY_FWD:
564 return FLOW_DIR_FWD;
565 };
566 }
567
568 static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl, u32 sk_sid)
569 {
570 struct xfrm_policy *pol;
571
572 read_lock_bh(&xfrm_policy_lock);
573 if ((pol = sk->sk_policy[dir]) != NULL) {
574 int match = xfrm_selector_match(&pol->selector, fl,
575 sk->sk_family);
576 int err = 0;
577
578 if (match)
579 err = security_xfrm_policy_lookup(pol, sk_sid, policy_to_flow_dir(dir));
580
581 if (match && !err)
582 xfrm_pol_hold(pol);
583 else
584 pol = NULL;
585 }
586 read_unlock_bh(&xfrm_policy_lock);
587 return pol;
588 }
589
590 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
591 {
592 pol->next = xfrm_policy_list[dir];
593 xfrm_policy_list[dir] = pol;
594 xfrm_pol_hold(pol);
595 }
596
597 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
598 int dir)
599 {
600 struct xfrm_policy **polp;
601
602 for (polp = &xfrm_policy_list[dir];
603 *polp != NULL; polp = &(*polp)->next) {
604 if (*polp == pol) {
605 *polp = pol->next;
606 return pol;
607 }
608 }
609 return NULL;
610 }
611
612 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
613 {
614 write_lock_bh(&xfrm_policy_lock);
615 pol = __xfrm_policy_unlink(pol, dir);
616 write_unlock_bh(&xfrm_policy_lock);
617 if (pol) {
618 if (dir < XFRM_POLICY_MAX)
619 atomic_inc(&flow_cache_genid);
620 xfrm_policy_kill(pol);
621 return 0;
622 }
623 return -ENOENT;
624 }
625
626 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
627 {
628 struct xfrm_policy *old_pol;
629
630 write_lock_bh(&xfrm_policy_lock);
631 old_pol = sk->sk_policy[dir];
632 sk->sk_policy[dir] = pol;
633 if (pol) {
634 pol->curlft.add_time = (unsigned long)xtime.tv_sec;
635 pol->index = xfrm_gen_index(XFRM_POLICY_MAX+dir);
636 __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
637 }
638 if (old_pol)
639 __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
640 write_unlock_bh(&xfrm_policy_lock);
641
642 if (old_pol) {
643 xfrm_policy_kill(old_pol);
644 }
645 return 0;
646 }
647
648 static struct xfrm_policy *clone_policy(struct xfrm_policy *old, int dir)
649 {
650 struct xfrm_policy *newp = xfrm_policy_alloc(GFP_ATOMIC);
651
652 if (newp) {
653 newp->selector = old->selector;
654 if (security_xfrm_policy_clone(old, newp)) {
655 kfree(newp);
656 return NULL; /* ENOMEM */
657 }
658 newp->lft = old->lft;
659 newp->curlft = old->curlft;
660 newp->action = old->action;
661 newp->flags = old->flags;
662 newp->xfrm_nr = old->xfrm_nr;
663 newp->index = old->index;
664 memcpy(newp->xfrm_vec, old->xfrm_vec,
665 newp->xfrm_nr*sizeof(struct xfrm_tmpl));
666 write_lock_bh(&xfrm_policy_lock);
667 __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir);
668 write_unlock_bh(&xfrm_policy_lock);
669 xfrm_pol_put(newp);
670 }
671 return newp;
672 }
673
674 int __xfrm_sk_clone_policy(struct sock *sk)
675 {
676 struct xfrm_policy *p0 = sk->sk_policy[0],
677 *p1 = sk->sk_policy[1];
678
679 sk->sk_policy[0] = sk->sk_policy[1] = NULL;
680 if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL)
681 return -ENOMEM;
682 if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL)
683 return -ENOMEM;
684 return 0;
685 }
686
687 /* Resolve list of templates for the flow, given policy. */
688
689 static int
690 xfrm_tmpl_resolve(struct xfrm_policy *policy, struct flowi *fl,
691 struct xfrm_state **xfrm,
692 unsigned short family)
693 {
694 int nx;
695 int i, error;
696 xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
697 xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
698
699 for (nx=0, i = 0; i < policy->xfrm_nr; i++) {
700 struct xfrm_state *x;
701 xfrm_address_t *remote = daddr;
702 xfrm_address_t *local = saddr;
703 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
704
705 if (tmpl->mode) {
706 remote = &tmpl->id.daddr;
707 local = &tmpl->saddr;
708 }
709
710 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
711
712 if (x && x->km.state == XFRM_STATE_VALID) {
713 xfrm[nx++] = x;
714 daddr = remote;
715 saddr = local;
716 continue;
717 }
718 if (x) {
719 error = (x->km.state == XFRM_STATE_ERROR ?
720 -EINVAL : -EAGAIN);
721 xfrm_state_put(x);
722 }
723
724 if (!tmpl->optional)
725 goto fail;
726 }
727 return nx;
728
729 fail:
730 for (nx--; nx>=0; nx--)
731 xfrm_state_put(xfrm[nx]);
732 return error;
733 }
734
735 /* Check that the bundle accepts the flow and its components are
736 * still valid.
737 */
738
739 static struct dst_entry *
740 xfrm_find_bundle(struct flowi *fl, struct xfrm_policy *policy, unsigned short family)
741 {
742 struct dst_entry *x;
743 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
744 if (unlikely(afinfo == NULL))
745 return ERR_PTR(-EINVAL);
746 x = afinfo->find_bundle(fl, policy);
747 xfrm_policy_put_afinfo(afinfo);
748 return x;
749 }
750
751 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
752 * all the metrics... Shortly, bundle a bundle.
753 */
754
755 static int
756 xfrm_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
757 struct flowi *fl, struct dst_entry **dst_p,
758 unsigned short family)
759 {
760 int err;
761 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
762 if (unlikely(afinfo == NULL))
763 return -EINVAL;
764 err = afinfo->bundle_create(policy, xfrm, nx, fl, dst_p);
765 xfrm_policy_put_afinfo(afinfo);
766 return err;
767 }
768
769
770 static int stale_bundle(struct dst_entry *dst);
771
772 /* Main function: finds/creates a bundle for given flow.
773 *
774 * At the moment we eat a raw IP route. Mostly to speed up lookups
775 * on interfaces with disabled IPsec.
776 */
777 int xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
778 struct sock *sk, int flags)
779 {
780 struct xfrm_policy *policy;
781 struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
782 struct dst_entry *dst, *dst_orig = *dst_p;
783 int nx = 0;
784 int err;
785 u32 genid;
786 u16 family = dst_orig->ops->family;
787 u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
788 u32 sk_sid = security_sk_sid(sk, fl, dir);
789 restart:
790 genid = atomic_read(&flow_cache_genid);
791 policy = NULL;
792 if (sk && sk->sk_policy[1])
793 policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, sk_sid);
794
795 if (!policy) {
796 /* To accelerate a bit... */
797 if ((dst_orig->flags & DST_NOXFRM) || !xfrm_policy_list[XFRM_POLICY_OUT])
798 return 0;
799
800 policy = flow_cache_lookup(fl, sk_sid, family, dir,
801 xfrm_policy_lookup);
802 }
803
804 if (!policy)
805 return 0;
806
807 policy->curlft.use_time = (unsigned long)xtime.tv_sec;
808
809 switch (policy->action) {
810 case XFRM_POLICY_BLOCK:
811 /* Prohibit the flow */
812 err = -EPERM;
813 goto error;
814
815 case XFRM_POLICY_ALLOW:
816 if (policy->xfrm_nr == 0) {
817 /* Flow passes not transformed. */
818 xfrm_pol_put(policy);
819 return 0;
820 }
821
822 /* Try to find matching bundle.
823 *
824 * LATER: help from flow cache. It is optional, this
825 * is required only for output policy.
826 */
827 dst = xfrm_find_bundle(fl, policy, family);
828 if (IS_ERR(dst)) {
829 err = PTR_ERR(dst);
830 goto error;
831 }
832
833 if (dst)
834 break;
835
836 nx = xfrm_tmpl_resolve(policy, fl, xfrm, family);
837
838 if (unlikely(nx<0)) {
839 err = nx;
840 if (err == -EAGAIN && flags) {
841 DECLARE_WAITQUEUE(wait, current);
842
843 add_wait_queue(&km_waitq, &wait);
844 set_current_state(TASK_INTERRUPTIBLE);
845 schedule();
846 set_current_state(TASK_RUNNING);
847 remove_wait_queue(&km_waitq, &wait);
848
849 nx = xfrm_tmpl_resolve(policy, fl, xfrm, family);
850
851 if (nx == -EAGAIN && signal_pending(current)) {
852 err = -ERESTART;
853 goto error;
854 }
855 if (nx == -EAGAIN ||
856 genid != atomic_read(&flow_cache_genid)) {
857 xfrm_pol_put(policy);
858 goto restart;
859 }
860 err = nx;
861 }
862 if (err < 0)
863 goto error;
864 }
865 if (nx == 0) {
866 /* Flow passes not transformed. */
867 xfrm_pol_put(policy);
868 return 0;
869 }
870
871 dst = dst_orig;
872 err = xfrm_bundle_create(policy, xfrm, nx, fl, &dst, family);
873
874 if (unlikely(err)) {
875 int i;
876 for (i=0; i<nx; i++)
877 xfrm_state_put(xfrm[i]);
878 goto error;
879 }
880
881 write_lock_bh(&policy->lock);
882 if (unlikely(policy->dead || stale_bundle(dst))) {
883 /* Wow! While we worked on resolving, this
884 * policy has gone. Retry. It is not paranoia,
885 * we just cannot enlist new bundle to dead object.
886 * We can't enlist stable bundles either.
887 */
888 write_unlock_bh(&policy->lock);
889
890 xfrm_pol_put(policy);
891 if (dst)
892 dst_free(dst);
893 goto restart;
894 }
895 dst->next = policy->bundles;
896 policy->bundles = dst;
897 dst_hold(dst);
898 write_unlock_bh(&policy->lock);
899 }
900 *dst_p = dst;
901 dst_release(dst_orig);
902 xfrm_pol_put(policy);
903 return 0;
904
905 error:
906 dst_release(dst_orig);
907 xfrm_pol_put(policy);
908 *dst_p = NULL;
909 return err;
910 }
911 EXPORT_SYMBOL(xfrm_lookup);
912
913 /* When skb is transformed back to its "native" form, we have to
914 * check policy restrictions. At the moment we make this in maximally
915 * stupid way. Shame on me. :-) Of course, connected sockets must
916 * have policy cached at them.
917 */
918
919 static inline int
920 xfrm_state_ok(struct xfrm_tmpl *tmpl, struct xfrm_state *x,
921 unsigned short family)
922 {
923 if (xfrm_state_kern(x))
924 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, family);
925 return x->id.proto == tmpl->id.proto &&
926 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
927 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
928 x->props.mode == tmpl->mode &&
929 (tmpl->aalgos & (1<<x->props.aalgo)) &&
930 !(x->props.mode && xfrm_state_addr_cmp(tmpl, x, family));
931 }
932
933 static inline int
934 xfrm_policy_ok(struct xfrm_tmpl *tmpl, struct sec_path *sp, int start,
935 unsigned short family)
936 {
937 int idx = start;
938
939 if (tmpl->optional) {
940 if (!tmpl->mode)
941 return start;
942 } else
943 start = -1;
944 for (; idx < sp->len; idx++) {
945 if (xfrm_state_ok(tmpl, sp->x[idx].xvec, family))
946 return ++idx;
947 if (sp->x[idx].xvec->props.mode)
948 break;
949 }
950 return start;
951 }
952
953 int
954 xfrm_decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family)
955 {
956 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
957
958 if (unlikely(afinfo == NULL))
959 return -EAFNOSUPPORT;
960
961 afinfo->decode_session(skb, fl);
962 xfrm_policy_put_afinfo(afinfo);
963 return 0;
964 }
965 EXPORT_SYMBOL(xfrm_decode_session);
966
967 static inline int secpath_has_tunnel(struct sec_path *sp, int k)
968 {
969 for (; k < sp->len; k++) {
970 if (sp->x[k].xvec->props.mode)
971 return 1;
972 }
973
974 return 0;
975 }
976
977 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
978 unsigned short family)
979 {
980 struct xfrm_policy *pol;
981 struct flowi fl;
982 u8 fl_dir = policy_to_flow_dir(dir);
983 u32 sk_sid;
984
985 if (xfrm_decode_session(skb, &fl, family) < 0)
986 return 0;
987 nf_nat_decode_session(skb, &fl, family);
988
989 sk_sid = security_sk_sid(sk, &fl, fl_dir);
990
991 /* First, check used SA against their selectors. */
992 if (skb->sp) {
993 int i;
994
995 for (i=skb->sp->len-1; i>=0; i--) {
996 struct sec_decap_state *xvec = &(skb->sp->x[i]);
997 if (!xfrm_selector_match(&xvec->xvec->sel, &fl, family))
998 return 0;
999
1000 /* If there is a post_input processor, try running it */
1001 if (xvec->xvec->type->post_input &&
1002 (xvec->xvec->type->post_input)(xvec->xvec,
1003 &(xvec->decap),
1004 skb) != 0)
1005 return 0;
1006 }
1007 }
1008
1009 pol = NULL;
1010 if (sk && sk->sk_policy[dir])
1011 pol = xfrm_sk_policy_lookup(sk, dir, &fl, sk_sid);
1012
1013 if (!pol)
1014 pol = flow_cache_lookup(&fl, sk_sid, family, fl_dir,
1015 xfrm_policy_lookup);
1016
1017 if (!pol)
1018 return !skb->sp || !secpath_has_tunnel(skb->sp, 0);
1019
1020 pol->curlft.use_time = (unsigned long)xtime.tv_sec;
1021
1022 if (pol->action == XFRM_POLICY_ALLOW) {
1023 struct sec_path *sp;
1024 static struct sec_path dummy;
1025 int i, k;
1026
1027 if ((sp = skb->sp) == NULL)
1028 sp = &dummy;
1029
1030 /* For each tunnel xfrm, find the first matching tmpl.
1031 * For each tmpl before that, find corresponding xfrm.
1032 * Order is _important_. Later we will implement
1033 * some barriers, but at the moment barriers
1034 * are implied between each two transformations.
1035 */
1036 for (i = pol->xfrm_nr-1, k = 0; i >= 0; i--) {
1037 k = xfrm_policy_ok(pol->xfrm_vec+i, sp, k, family);
1038 if (k < 0)
1039 goto reject;
1040 }
1041
1042 if (secpath_has_tunnel(sp, k))
1043 goto reject;
1044
1045 xfrm_pol_put(pol);
1046 return 1;
1047 }
1048
1049 reject:
1050 xfrm_pol_put(pol);
1051 return 0;
1052 }
1053 EXPORT_SYMBOL(__xfrm_policy_check);
1054
1055 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
1056 {
1057 struct flowi fl;
1058
1059 if (xfrm_decode_session(skb, &fl, family) < 0)
1060 return 0;
1061
1062 return xfrm_lookup(&skb->dst, &fl, NULL, 0) == 0;
1063 }
1064 EXPORT_SYMBOL(__xfrm_route_forward);
1065
1066 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
1067 {
1068 /* If it is marked obsolete, which is how we even get here,
1069 * then we have purged it from the policy bundle list and we
1070 * did that for a good reason.
1071 */
1072 return NULL;
1073 }
1074
1075 static int stale_bundle(struct dst_entry *dst)
1076 {
1077 return !xfrm_bundle_ok((struct xfrm_dst *)dst, NULL, AF_UNSPEC);
1078 }
1079
1080 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
1081 {
1082 while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
1083 dst->dev = &loopback_dev;
1084 dev_hold(&loopback_dev);
1085 dev_put(dev);
1086 }
1087 }
1088 EXPORT_SYMBOL(xfrm_dst_ifdown);
1089
1090 static void xfrm_link_failure(struct sk_buff *skb)
1091 {
1092 /* Impossible. Such dst must be popped before reaches point of failure. */
1093 return;
1094 }
1095
1096 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
1097 {
1098 if (dst) {
1099 if (dst->obsolete) {
1100 dst_release(dst);
1101 dst = NULL;
1102 }
1103 }
1104 return dst;
1105 }
1106
1107 static void xfrm_prune_bundles(int (*func)(struct dst_entry *))
1108 {
1109 int i;
1110 struct xfrm_policy *pol;
1111 struct dst_entry *dst, **dstp, *gc_list = NULL;
1112
1113 read_lock_bh(&xfrm_policy_lock);
1114 for (i=0; i<2*XFRM_POLICY_MAX; i++) {
1115 for (pol = xfrm_policy_list[i]; pol; pol = pol->next) {
1116 write_lock(&pol->lock);
1117 dstp = &pol->bundles;
1118 while ((dst=*dstp) != NULL) {
1119 if (func(dst)) {
1120 *dstp = dst->next;
1121 dst->next = gc_list;
1122 gc_list = dst;
1123 } else {
1124 dstp = &dst->next;
1125 }
1126 }
1127 write_unlock(&pol->lock);
1128 }
1129 }
1130 read_unlock_bh(&xfrm_policy_lock);
1131
1132 while (gc_list) {
1133 dst = gc_list;
1134 gc_list = dst->next;
1135 dst_free(dst);
1136 }
1137 }
1138
1139 static int unused_bundle(struct dst_entry *dst)
1140 {
1141 return !atomic_read(&dst->__refcnt);
1142 }
1143
1144 static void __xfrm_garbage_collect(void)
1145 {
1146 xfrm_prune_bundles(unused_bundle);
1147 }
1148
1149 int xfrm_flush_bundles(void)
1150 {
1151 xfrm_prune_bundles(stale_bundle);
1152 return 0;
1153 }
1154
1155 static int always_true(struct dst_entry *dst)
1156 {
1157 return 1;
1158 }
1159
1160 void xfrm_flush_all_bundles(void)
1161 {
1162 xfrm_prune_bundles(always_true);
1163 }
1164
1165 void xfrm_init_pmtu(struct dst_entry *dst)
1166 {
1167 do {
1168 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1169 u32 pmtu, route_mtu_cached;
1170
1171 pmtu = dst_mtu(dst->child);
1172 xdst->child_mtu_cached = pmtu;
1173
1174 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
1175
1176 route_mtu_cached = dst_mtu(xdst->route);
1177 xdst->route_mtu_cached = route_mtu_cached;
1178
1179 if (pmtu > route_mtu_cached)
1180 pmtu = route_mtu_cached;
1181
1182 dst->metrics[RTAX_MTU-1] = pmtu;
1183 } while ((dst = dst->next));
1184 }
1185
1186 EXPORT_SYMBOL(xfrm_init_pmtu);
1187
1188 /* Check that the bundle accepts the flow and its components are
1189 * still valid.
1190 */
1191
1192 int xfrm_bundle_ok(struct xfrm_dst *first, struct flowi *fl, int family)
1193 {
1194 struct dst_entry *dst = &first->u.dst;
1195 struct xfrm_dst *last;
1196 u32 mtu;
1197
1198 if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) ||
1199 (dst->dev && !netif_running(dst->dev)))
1200 return 0;
1201
1202 last = NULL;
1203
1204 do {
1205 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1206
1207 if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family))
1208 return 0;
1209 if (dst->xfrm->km.state != XFRM_STATE_VALID)
1210 return 0;
1211
1212 mtu = dst_mtu(dst->child);
1213 if (xdst->child_mtu_cached != mtu) {
1214 last = xdst;
1215 xdst->child_mtu_cached = mtu;
1216 }
1217
1218 if (!dst_check(xdst->route, xdst->route_cookie))
1219 return 0;
1220 mtu = dst_mtu(xdst->route);
1221 if (xdst->route_mtu_cached != mtu) {
1222 last = xdst;
1223 xdst->route_mtu_cached = mtu;
1224 }
1225
1226 dst = dst->child;
1227 } while (dst->xfrm);
1228
1229 if (likely(!last))
1230 return 1;
1231
1232 mtu = last->child_mtu_cached;
1233 for (;;) {
1234 dst = &last->u.dst;
1235
1236 mtu = xfrm_state_mtu(dst->xfrm, mtu);
1237 if (mtu > last->route_mtu_cached)
1238 mtu = last->route_mtu_cached;
1239 dst->metrics[RTAX_MTU-1] = mtu;
1240
1241 if (last == first)
1242 break;
1243
1244 last = last->u.next;
1245 last->child_mtu_cached = mtu;
1246 }
1247
1248 return 1;
1249 }
1250
1251 EXPORT_SYMBOL(xfrm_bundle_ok);
1252
1253 int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
1254 {
1255 int err = 0;
1256 if (unlikely(afinfo == NULL))
1257 return -EINVAL;
1258 if (unlikely(afinfo->family >= NPROTO))
1259 return -EAFNOSUPPORT;
1260 write_lock(&xfrm_policy_afinfo_lock);
1261 if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
1262 err = -ENOBUFS;
1263 else {
1264 struct dst_ops *dst_ops = afinfo->dst_ops;
1265 if (likely(dst_ops->kmem_cachep == NULL))
1266 dst_ops->kmem_cachep = xfrm_dst_cache;
1267 if (likely(dst_ops->check == NULL))
1268 dst_ops->check = xfrm_dst_check;
1269 if (likely(dst_ops->negative_advice == NULL))
1270 dst_ops->negative_advice = xfrm_negative_advice;
1271 if (likely(dst_ops->link_failure == NULL))
1272 dst_ops->link_failure = xfrm_link_failure;
1273 if (likely(afinfo->garbage_collect == NULL))
1274 afinfo->garbage_collect = __xfrm_garbage_collect;
1275 xfrm_policy_afinfo[afinfo->family] = afinfo;
1276 }
1277 write_unlock(&xfrm_policy_afinfo_lock);
1278 return err;
1279 }
1280 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
1281
1282 int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
1283 {
1284 int err = 0;
1285 if (unlikely(afinfo == NULL))
1286 return -EINVAL;
1287 if (unlikely(afinfo->family >= NPROTO))
1288 return -EAFNOSUPPORT;
1289 write_lock(&xfrm_policy_afinfo_lock);
1290 if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
1291 if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
1292 err = -EINVAL;
1293 else {
1294 struct dst_ops *dst_ops = afinfo->dst_ops;
1295 xfrm_policy_afinfo[afinfo->family] = NULL;
1296 dst_ops->kmem_cachep = NULL;
1297 dst_ops->check = NULL;
1298 dst_ops->negative_advice = NULL;
1299 dst_ops->link_failure = NULL;
1300 afinfo->garbage_collect = NULL;
1301 }
1302 }
1303 write_unlock(&xfrm_policy_afinfo_lock);
1304 return err;
1305 }
1306 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
1307
1308 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
1309 {
1310 struct xfrm_policy_afinfo *afinfo;
1311 if (unlikely(family >= NPROTO))
1312 return NULL;
1313 read_lock(&xfrm_policy_afinfo_lock);
1314 afinfo = xfrm_policy_afinfo[family];
1315 if (likely(afinfo != NULL))
1316 read_lock(&afinfo->lock);
1317 read_unlock(&xfrm_policy_afinfo_lock);
1318 return afinfo;
1319 }
1320
1321 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
1322 {
1323 if (unlikely(afinfo == NULL))
1324 return;
1325 read_unlock(&afinfo->lock);
1326 }
1327
1328 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
1329 {
1330 switch (event) {
1331 case NETDEV_DOWN:
1332 xfrm_flush_bundles();
1333 }
1334 return NOTIFY_DONE;
1335 }
1336
1337 static struct notifier_block xfrm_dev_notifier = {
1338 xfrm_dev_event,
1339 NULL,
1340 0
1341 };
1342
1343 static void __init xfrm_policy_init(void)
1344 {
1345 xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
1346 sizeof(struct xfrm_dst),
1347 0, SLAB_HWCACHE_ALIGN,
1348 NULL, NULL);
1349 if (!xfrm_dst_cache)
1350 panic("XFRM: failed to allocate xfrm_dst_cache\n");
1351
1352 INIT_WORK(&xfrm_policy_gc_work, xfrm_policy_gc_task, NULL);
1353 register_netdevice_notifier(&xfrm_dev_notifier);
1354 }
1355
1356 void __init xfrm_init(void)
1357 {
1358 xfrm_state_init();
1359 xfrm_policy_init();
1360 xfrm_input_init();
1361 }
1362
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