blob: 061b44cc245170ac7f9336cf3447d0597bb15164 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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/module.h>
26#include <net/xfrm.h>
27#include <net/ip.h>
28
29DECLARE_MUTEX(xfrm_cfg_sem);
30EXPORT_SYMBOL(xfrm_cfg_sem);
31
32static DEFINE_RWLOCK(xfrm_policy_lock);
33
34struct xfrm_policy *xfrm_policy_list[XFRM_POLICY_MAX*2];
35EXPORT_SYMBOL(xfrm_policy_list);
36
37static DEFINE_RWLOCK(xfrm_policy_afinfo_lock);
38static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO];
39
Eric Dumazetba899662005-08-26 12:05:31 -070040static kmem_cache_t *xfrm_dst_cache __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
42static struct work_struct xfrm_policy_gc_work;
43static struct list_head xfrm_policy_gc_list =
44 LIST_HEAD_INIT(xfrm_policy_gc_list);
45static DEFINE_SPINLOCK(xfrm_policy_gc_lock);
46
47static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family);
48static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);
49
50int xfrm_register_type(struct xfrm_type *type, unsigned short family)
51{
52 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
53 struct xfrm_type_map *typemap;
54 int err = 0;
55
56 if (unlikely(afinfo == NULL))
57 return -EAFNOSUPPORT;
58 typemap = afinfo->type_map;
59
60 write_lock(&typemap->lock);
61 if (likely(typemap->map[type->proto] == NULL))
62 typemap->map[type->proto] = type;
63 else
64 err = -EEXIST;
65 write_unlock(&typemap->lock);
66 xfrm_policy_put_afinfo(afinfo);
67 return err;
68}
69EXPORT_SYMBOL(xfrm_register_type);
70
71int xfrm_unregister_type(struct xfrm_type *type, unsigned short family)
72{
73 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
74 struct xfrm_type_map *typemap;
75 int err = 0;
76
77 if (unlikely(afinfo == NULL))
78 return -EAFNOSUPPORT;
79 typemap = afinfo->type_map;
80
81 write_lock(&typemap->lock);
82 if (unlikely(typemap->map[type->proto] != type))
83 err = -ENOENT;
84 else
85 typemap->map[type->proto] = NULL;
86 write_unlock(&typemap->lock);
87 xfrm_policy_put_afinfo(afinfo);
88 return err;
89}
90EXPORT_SYMBOL(xfrm_unregister_type);
91
92struct xfrm_type *xfrm_get_type(u8 proto, unsigned short family)
93{
94 struct xfrm_policy_afinfo *afinfo;
95 struct xfrm_type_map *typemap;
96 struct xfrm_type *type;
97 int modload_attempted = 0;
98
99retry:
100 afinfo = xfrm_policy_get_afinfo(family);
101 if (unlikely(afinfo == NULL))
102 return NULL;
103 typemap = afinfo->type_map;
104
105 read_lock(&typemap->lock);
106 type = typemap->map[proto];
107 if (unlikely(type && !try_module_get(type->owner)))
108 type = NULL;
109 read_unlock(&typemap->lock);
110 if (!type && !modload_attempted) {
111 xfrm_policy_put_afinfo(afinfo);
112 request_module("xfrm-type-%d-%d",
113 (int) family, (int) proto);
114 modload_attempted = 1;
115 goto retry;
116 }
117
118 xfrm_policy_put_afinfo(afinfo);
119 return type;
120}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121
122int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl,
123 unsigned short family)
124{
125 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
126 int err = 0;
127
128 if (unlikely(afinfo == NULL))
129 return -EAFNOSUPPORT;
130
131 if (likely(afinfo->dst_lookup != NULL))
132 err = afinfo->dst_lookup(dst, fl);
133 else
134 err = -EINVAL;
135 xfrm_policy_put_afinfo(afinfo);
136 return err;
137}
138EXPORT_SYMBOL(xfrm_dst_lookup);
139
140void xfrm_put_type(struct xfrm_type *type)
141{
142 module_put(type->owner);
143}
144
145static inline unsigned long make_jiffies(long secs)
146{
147 if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
148 return MAX_SCHEDULE_TIMEOUT-1;
149 else
150 return secs*HZ;
151}
152
153static void xfrm_policy_timer(unsigned long data)
154{
155 struct xfrm_policy *xp = (struct xfrm_policy*)data;
156 unsigned long now = (unsigned long)xtime.tv_sec;
157 long next = LONG_MAX;
158 int warn = 0;
159 int dir;
160
161 read_lock(&xp->lock);
162
163 if (xp->dead)
164 goto out;
165
Herbert Xu77d8d7a2005-10-05 12:15:12 -0700166 dir = xfrm_policy_id2dir(xp->index);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167
168 if (xp->lft.hard_add_expires_seconds) {
169 long tmo = xp->lft.hard_add_expires_seconds +
170 xp->curlft.add_time - now;
171 if (tmo <= 0)
172 goto expired;
173 if (tmo < next)
174 next = tmo;
175 }
176 if (xp->lft.hard_use_expires_seconds) {
177 long tmo = xp->lft.hard_use_expires_seconds +
178 (xp->curlft.use_time ? : xp->curlft.add_time) - now;
179 if (tmo <= 0)
180 goto expired;
181 if (tmo < next)
182 next = tmo;
183 }
184 if (xp->lft.soft_add_expires_seconds) {
185 long tmo = xp->lft.soft_add_expires_seconds +
186 xp->curlft.add_time - now;
187 if (tmo <= 0) {
188 warn = 1;
189 tmo = XFRM_KM_TIMEOUT;
190 }
191 if (tmo < next)
192 next = tmo;
193 }
194 if (xp->lft.soft_use_expires_seconds) {
195 long tmo = xp->lft.soft_use_expires_seconds +
196 (xp->curlft.use_time ? : xp->curlft.add_time) - now;
197 if (tmo <= 0) {
198 warn = 1;
199 tmo = XFRM_KM_TIMEOUT;
200 }
201 if (tmo < next)
202 next = tmo;
203 }
204
205 if (warn)
206 km_policy_expired(xp, dir, 0);
207 if (next != LONG_MAX &&
208 !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
209 xfrm_pol_hold(xp);
210
211out:
212 read_unlock(&xp->lock);
213 xfrm_pol_put(xp);
214 return;
215
216expired:
217 read_unlock(&xp->lock);
Herbert Xu4666faa2005-06-18 22:43:22 -0700218 if (!xfrm_policy_delete(xp, dir))
219 km_policy_expired(xp, dir, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 xfrm_pol_put(xp);
221}
222
223
224/* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
225 * SPD calls.
226 */
227
Randy Dunlap83fa3402005-10-04 22:45:35 -0700228struct xfrm_policy *xfrm_policy_alloc(unsigned int __nocast gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229{
230 struct xfrm_policy *policy;
231
232 policy = kmalloc(sizeof(struct xfrm_policy), gfp);
233
234 if (policy) {
235 memset(policy, 0, sizeof(struct xfrm_policy));
236 atomic_set(&policy->refcnt, 1);
237 rwlock_init(&policy->lock);
238 init_timer(&policy->timer);
239 policy->timer.data = (unsigned long)policy;
240 policy->timer.function = xfrm_policy_timer;
241 }
242 return policy;
243}
244EXPORT_SYMBOL(xfrm_policy_alloc);
245
246/* Destroy xfrm_policy: descendant resources must be released to this moment. */
247
248void __xfrm_policy_destroy(struct xfrm_policy *policy)
249{
250 if (!policy->dead)
251 BUG();
252
253 if (policy->bundles)
254 BUG();
255
256 if (del_timer(&policy->timer))
257 BUG();
258
259 kfree(policy);
260}
261EXPORT_SYMBOL(__xfrm_policy_destroy);
262
263static 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
281static 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
301static 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. */
324static 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
344int 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
350 write_lock_bh(&xfrm_policy_lock);
351 for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL;) {
352 if (!delpol && memcmp(&policy->selector, &pol->selector, sizeof(pol->selector)) == 0) {
353 if (excl) {
354 write_unlock_bh(&xfrm_policy_lock);
355 return -EEXIST;
356 }
357 *p = pol->next;
358 delpol = pol;
359 if (policy->priority > pol->priority)
360 continue;
361 } else if (policy->priority >= pol->priority) {
362 p = &pol->next;
363 continue;
364 }
365 if (!newpos)
366 newpos = p;
367 if (delpol)
368 break;
369 p = &pol->next;
370 }
371 if (newpos)
372 p = newpos;
373 xfrm_pol_hold(policy);
374 policy->next = *p;
375 *p = policy;
376 atomic_inc(&flow_cache_genid);
377 policy->index = delpol ? delpol->index : xfrm_gen_index(dir);
378 policy->curlft.add_time = (unsigned long)xtime.tv_sec;
379 policy->curlft.use_time = 0;
380 if (!mod_timer(&policy->timer, jiffies + HZ))
381 xfrm_pol_hold(policy);
382 write_unlock_bh(&xfrm_policy_lock);
383
384 if (delpol) {
385 xfrm_policy_kill(delpol);
386 }
387 return 0;
388}
389EXPORT_SYMBOL(xfrm_policy_insert);
390
391struct xfrm_policy *xfrm_policy_bysel(int dir, struct xfrm_selector *sel,
392 int delete)
393{
394 struct xfrm_policy *pol, **p;
395
396 write_lock_bh(&xfrm_policy_lock);
397 for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL; p = &pol->next) {
398 if (memcmp(sel, &pol->selector, sizeof(*sel)) == 0) {
399 xfrm_pol_hold(pol);
400 if (delete)
401 *p = pol->next;
402 break;
403 }
404 }
405 write_unlock_bh(&xfrm_policy_lock);
406
407 if (pol && delete) {
408 atomic_inc(&flow_cache_genid);
409 xfrm_policy_kill(pol);
410 }
411 return pol;
412}
413EXPORT_SYMBOL(xfrm_policy_bysel);
414
415struct xfrm_policy *xfrm_policy_byid(int dir, u32 id, int delete)
416{
417 struct xfrm_policy *pol, **p;
418
419 write_lock_bh(&xfrm_policy_lock);
Herbert Xu77d8d7a2005-10-05 12:15:12 -0700420 for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL; p = &pol->next) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 if (pol->index == id) {
422 xfrm_pol_hold(pol);
423 if (delete)
424 *p = pol->next;
425 break;
426 }
427 }
428 write_unlock_bh(&xfrm_policy_lock);
429
430 if (pol && delete) {
431 atomic_inc(&flow_cache_genid);
432 xfrm_policy_kill(pol);
433 }
434 return pol;
435}
436EXPORT_SYMBOL(xfrm_policy_byid);
437
438void xfrm_policy_flush(void)
439{
440 struct xfrm_policy *xp;
441 int dir;
442
443 write_lock_bh(&xfrm_policy_lock);
444 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
445 while ((xp = xfrm_policy_list[dir]) != NULL) {
446 xfrm_policy_list[dir] = xp->next;
447 write_unlock_bh(&xfrm_policy_lock);
448
449 xfrm_policy_kill(xp);
450
451 write_lock_bh(&xfrm_policy_lock);
452 }
453 }
454 atomic_inc(&flow_cache_genid);
455 write_unlock_bh(&xfrm_policy_lock);
456}
457EXPORT_SYMBOL(xfrm_policy_flush);
458
459int xfrm_policy_walk(int (*func)(struct xfrm_policy *, int, int, void*),
460 void *data)
461{
462 struct xfrm_policy *xp;
463 int dir;
464 int count = 0;
465 int error = 0;
466
467 read_lock_bh(&xfrm_policy_lock);
468 for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
469 for (xp = xfrm_policy_list[dir]; xp; xp = xp->next)
470 count++;
471 }
472
473 if (count == 0) {
474 error = -ENOENT;
475 goto out;
476 }
477
478 for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
479 for (xp = xfrm_policy_list[dir]; xp; xp = xp->next) {
480 error = func(xp, dir%XFRM_POLICY_MAX, --count, data);
481 if (error)
482 goto out;
483 }
484 }
485
486out:
487 read_unlock_bh(&xfrm_policy_lock);
488 return error;
489}
490EXPORT_SYMBOL(xfrm_policy_walk);
491
492/* Find policy to apply to this flow. */
493
494static void xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
495 void **objp, atomic_t **obj_refp)
496{
497 struct xfrm_policy *pol;
498
499 read_lock_bh(&xfrm_policy_lock);
500 for (pol = xfrm_policy_list[dir]; pol; pol = pol->next) {
501 struct xfrm_selector *sel = &pol->selector;
502 int match;
503
504 if (pol->family != family)
505 continue;
506
507 match = xfrm_selector_match(sel, fl, family);
508 if (match) {
509 xfrm_pol_hold(pol);
510 break;
511 }
512 }
513 read_unlock_bh(&xfrm_policy_lock);
514 if ((*objp = (void *) pol) != NULL)
515 *obj_refp = &pol->refcnt;
516}
517
518static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl)
519{
520 struct xfrm_policy *pol;
521
522 read_lock_bh(&xfrm_policy_lock);
523 if ((pol = sk->sk_policy[dir]) != NULL) {
524 int match = xfrm_selector_match(&pol->selector, fl,
525 sk->sk_family);
526 if (match)
527 xfrm_pol_hold(pol);
528 else
529 pol = NULL;
530 }
531 read_unlock_bh(&xfrm_policy_lock);
532 return pol;
533}
534
535static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
536{
537 pol->next = xfrm_policy_list[dir];
538 xfrm_policy_list[dir] = pol;
539 xfrm_pol_hold(pol);
540}
541
542static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
543 int dir)
544{
545 struct xfrm_policy **polp;
546
547 for (polp = &xfrm_policy_list[dir];
548 *polp != NULL; polp = &(*polp)->next) {
549 if (*polp == pol) {
550 *polp = pol->next;
551 return pol;
552 }
553 }
554 return NULL;
555}
556
Herbert Xu4666faa2005-06-18 22:43:22 -0700557int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558{
559 write_lock_bh(&xfrm_policy_lock);
560 pol = __xfrm_policy_unlink(pol, dir);
561 write_unlock_bh(&xfrm_policy_lock);
562 if (pol) {
563 if (dir < XFRM_POLICY_MAX)
564 atomic_inc(&flow_cache_genid);
565 xfrm_policy_kill(pol);
Herbert Xu4666faa2005-06-18 22:43:22 -0700566 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 }
Herbert Xu4666faa2005-06-18 22:43:22 -0700568 return -ENOENT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569}
570
571int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
572{
573 struct xfrm_policy *old_pol;
574
575 write_lock_bh(&xfrm_policy_lock);
576 old_pol = sk->sk_policy[dir];
577 sk->sk_policy[dir] = pol;
578 if (pol) {
579 pol->curlft.add_time = (unsigned long)xtime.tv_sec;
580 pol->index = xfrm_gen_index(XFRM_POLICY_MAX+dir);
581 __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
582 }
583 if (old_pol)
584 __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
585 write_unlock_bh(&xfrm_policy_lock);
586
587 if (old_pol) {
588 xfrm_policy_kill(old_pol);
589 }
590 return 0;
591}
592
593static struct xfrm_policy *clone_policy(struct xfrm_policy *old, int dir)
594{
595 struct xfrm_policy *newp = xfrm_policy_alloc(GFP_ATOMIC);
596
597 if (newp) {
598 newp->selector = old->selector;
599 newp->lft = old->lft;
600 newp->curlft = old->curlft;
601 newp->action = old->action;
602 newp->flags = old->flags;
603 newp->xfrm_nr = old->xfrm_nr;
604 newp->index = old->index;
605 memcpy(newp->xfrm_vec, old->xfrm_vec,
606 newp->xfrm_nr*sizeof(struct xfrm_tmpl));
607 write_lock_bh(&xfrm_policy_lock);
608 __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir);
609 write_unlock_bh(&xfrm_policy_lock);
610 xfrm_pol_put(newp);
611 }
612 return newp;
613}
614
615int __xfrm_sk_clone_policy(struct sock *sk)
616{
617 struct xfrm_policy *p0 = sk->sk_policy[0],
618 *p1 = sk->sk_policy[1];
619
620 sk->sk_policy[0] = sk->sk_policy[1] = NULL;
621 if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL)
622 return -ENOMEM;
623 if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL)
624 return -ENOMEM;
625 return 0;
626}
627
628/* Resolve list of templates for the flow, given policy. */
629
630static int
631xfrm_tmpl_resolve(struct xfrm_policy *policy, struct flowi *fl,
632 struct xfrm_state **xfrm,
633 unsigned short family)
634{
635 int nx;
636 int i, error;
637 xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
638 xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
639
640 for (nx=0, i = 0; i < policy->xfrm_nr; i++) {
641 struct xfrm_state *x;
642 xfrm_address_t *remote = daddr;
643 xfrm_address_t *local = saddr;
644 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
645
646 if (tmpl->mode) {
647 remote = &tmpl->id.daddr;
648 local = &tmpl->saddr;
649 }
650
651 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
652
653 if (x && x->km.state == XFRM_STATE_VALID) {
654 xfrm[nx++] = x;
655 daddr = remote;
656 saddr = local;
657 continue;
658 }
659 if (x) {
660 error = (x->km.state == XFRM_STATE_ERROR ?
661 -EINVAL : -EAGAIN);
662 xfrm_state_put(x);
663 }
664
665 if (!tmpl->optional)
666 goto fail;
667 }
668 return nx;
669
670fail:
671 for (nx--; nx>=0; nx--)
672 xfrm_state_put(xfrm[nx]);
673 return error;
674}
675
676/* Check that the bundle accepts the flow and its components are
677 * still valid.
678 */
679
680static struct dst_entry *
681xfrm_find_bundle(struct flowi *fl, struct xfrm_policy *policy, unsigned short family)
682{
683 struct dst_entry *x;
684 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
685 if (unlikely(afinfo == NULL))
686 return ERR_PTR(-EINVAL);
687 x = afinfo->find_bundle(fl, policy);
688 xfrm_policy_put_afinfo(afinfo);
689 return x;
690}
691
692/* Allocate chain of dst_entry's, attach known xfrm's, calculate
693 * all the metrics... Shortly, bundle a bundle.
694 */
695
696static int
697xfrm_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
698 struct flowi *fl, struct dst_entry **dst_p,
699 unsigned short family)
700{
701 int err;
702 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
703 if (unlikely(afinfo == NULL))
704 return -EINVAL;
705 err = afinfo->bundle_create(policy, xfrm, nx, fl, dst_p);
706 xfrm_policy_put_afinfo(afinfo);
707 return err;
708}
709
710static inline int policy_to_flow_dir(int dir)
711{
712 if (XFRM_POLICY_IN == FLOW_DIR_IN &&
713 XFRM_POLICY_OUT == FLOW_DIR_OUT &&
714 XFRM_POLICY_FWD == FLOW_DIR_FWD)
715 return dir;
716 switch (dir) {
717 default:
718 case XFRM_POLICY_IN:
719 return FLOW_DIR_IN;
720 case XFRM_POLICY_OUT:
721 return FLOW_DIR_OUT;
722 case XFRM_POLICY_FWD:
723 return FLOW_DIR_FWD;
724 };
725}
726
727static int stale_bundle(struct dst_entry *dst);
728
729/* Main function: finds/creates a bundle for given flow.
730 *
731 * At the moment we eat a raw IP route. Mostly to speed up lookups
732 * on interfaces with disabled IPsec.
733 */
734int xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
735 struct sock *sk, int flags)
736{
737 struct xfrm_policy *policy;
738 struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
739 struct dst_entry *dst, *dst_orig = *dst_p;
740 int nx = 0;
741 int err;
742 u32 genid;
743 u16 family = dst_orig->ops->family;
744restart:
745 genid = atomic_read(&flow_cache_genid);
746 policy = NULL;
747 if (sk && sk->sk_policy[1])
748 policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
749
750 if (!policy) {
751 /* To accelerate a bit... */
752 if ((dst_orig->flags & DST_NOXFRM) || !xfrm_policy_list[XFRM_POLICY_OUT])
753 return 0;
754
755 policy = flow_cache_lookup(fl, family,
756 policy_to_flow_dir(XFRM_POLICY_OUT),
757 xfrm_policy_lookup);
758 }
759
760 if (!policy)
761 return 0;
762
763 policy->curlft.use_time = (unsigned long)xtime.tv_sec;
764
765 switch (policy->action) {
766 case XFRM_POLICY_BLOCK:
767 /* Prohibit the flow */
Patrick McHardye104411b2005-09-08 15:11:55 -0700768 err = -EPERM;
769 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770
771 case XFRM_POLICY_ALLOW:
772 if (policy->xfrm_nr == 0) {
773 /* Flow passes not transformed. */
774 xfrm_pol_put(policy);
775 return 0;
776 }
777
778 /* Try to find matching bundle.
779 *
780 * LATER: help from flow cache. It is optional, this
781 * is required only for output policy.
782 */
783 dst = xfrm_find_bundle(fl, policy, family);
784 if (IS_ERR(dst)) {
Patrick McHardye104411b2005-09-08 15:11:55 -0700785 err = PTR_ERR(dst);
786 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 }
788
789 if (dst)
790 break;
791
792 nx = xfrm_tmpl_resolve(policy, fl, xfrm, family);
793
794 if (unlikely(nx<0)) {
795 err = nx;
796 if (err == -EAGAIN && flags) {
797 DECLARE_WAITQUEUE(wait, current);
798
799 add_wait_queue(&km_waitq, &wait);
800 set_current_state(TASK_INTERRUPTIBLE);
801 schedule();
802 set_current_state(TASK_RUNNING);
803 remove_wait_queue(&km_waitq, &wait);
804
805 nx = xfrm_tmpl_resolve(policy, fl, xfrm, family);
806
807 if (nx == -EAGAIN && signal_pending(current)) {
808 err = -ERESTART;
809 goto error;
810 }
811 if (nx == -EAGAIN ||
812 genid != atomic_read(&flow_cache_genid)) {
813 xfrm_pol_put(policy);
814 goto restart;
815 }
816 err = nx;
817 }
818 if (err < 0)
819 goto error;
820 }
821 if (nx == 0) {
822 /* Flow passes not transformed. */
823 xfrm_pol_put(policy);
824 return 0;
825 }
826
827 dst = dst_orig;
828 err = xfrm_bundle_create(policy, xfrm, nx, fl, &dst, family);
829
830 if (unlikely(err)) {
831 int i;
832 for (i=0; i<nx; i++)
833 xfrm_state_put(xfrm[i]);
834 goto error;
835 }
836
837 write_lock_bh(&policy->lock);
838 if (unlikely(policy->dead || stale_bundle(dst))) {
839 /* Wow! While we worked on resolving, this
840 * policy has gone. Retry. It is not paranoia,
841 * we just cannot enlist new bundle to dead object.
842 * We can't enlist stable bundles either.
843 */
844 write_unlock_bh(&policy->lock);
845
846 xfrm_pol_put(policy);
847 if (dst)
848 dst_free(dst);
849 goto restart;
850 }
851 dst->next = policy->bundles;
852 policy->bundles = dst;
853 dst_hold(dst);
854 write_unlock_bh(&policy->lock);
855 }
856 *dst_p = dst;
857 dst_release(dst_orig);
858 xfrm_pol_put(policy);
859 return 0;
860
861error:
862 dst_release(dst_orig);
863 xfrm_pol_put(policy);
864 *dst_p = NULL;
865 return err;
866}
867EXPORT_SYMBOL(xfrm_lookup);
868
869/* When skb is transformed back to its "native" form, we have to
870 * check policy restrictions. At the moment we make this in maximally
871 * stupid way. Shame on me. :-) Of course, connected sockets must
872 * have policy cached at them.
873 */
874
875static inline int
876xfrm_state_ok(struct xfrm_tmpl *tmpl, struct xfrm_state *x,
877 unsigned short family)
878{
879 if (xfrm_state_kern(x))
880 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, family);
881 return x->id.proto == tmpl->id.proto &&
882 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
883 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
884 x->props.mode == tmpl->mode &&
885 (tmpl->aalgos & (1<<x->props.aalgo)) &&
886 !(x->props.mode && xfrm_state_addr_cmp(tmpl, x, family));
887}
888
889static inline int
890xfrm_policy_ok(struct xfrm_tmpl *tmpl, struct sec_path *sp, int start,
891 unsigned short family)
892{
893 int idx = start;
894
895 if (tmpl->optional) {
896 if (!tmpl->mode)
897 return start;
898 } else
899 start = -1;
900 for (; idx < sp->len; idx++) {
901 if (xfrm_state_ok(tmpl, sp->x[idx].xvec, family))
902 return ++idx;
903 if (sp->x[idx].xvec->props.mode)
904 break;
905 }
906 return start;
907}
908
909static int
910_decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family)
911{
912 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
913
914 if (unlikely(afinfo == NULL))
915 return -EAFNOSUPPORT;
916
917 afinfo->decode_session(skb, fl);
918 xfrm_policy_put_afinfo(afinfo);
919 return 0;
920}
921
922static inline int secpath_has_tunnel(struct sec_path *sp, int k)
923{
924 for (; k < sp->len; k++) {
925 if (sp->x[k].xvec->props.mode)
926 return 1;
927 }
928
929 return 0;
930}
931
932int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
933 unsigned short family)
934{
935 struct xfrm_policy *pol;
936 struct flowi fl;
937
938 if (_decode_session(skb, &fl, family) < 0)
939 return 0;
940
941 /* First, check used SA against their selectors. */
942 if (skb->sp) {
943 int i;
944
945 for (i=skb->sp->len-1; i>=0; i--) {
946 struct sec_decap_state *xvec = &(skb->sp->x[i]);
947 if (!xfrm_selector_match(&xvec->xvec->sel, &fl, family))
948 return 0;
949
950 /* If there is a post_input processor, try running it */
951 if (xvec->xvec->type->post_input &&
952 (xvec->xvec->type->post_input)(xvec->xvec,
953 &(xvec->decap),
954 skb) != 0)
955 return 0;
956 }
957 }
958
959 pol = NULL;
960 if (sk && sk->sk_policy[dir])
961 pol = xfrm_sk_policy_lookup(sk, dir, &fl);
962
963 if (!pol)
964 pol = flow_cache_lookup(&fl, family,
965 policy_to_flow_dir(dir),
966 xfrm_policy_lookup);
967
968 if (!pol)
969 return !skb->sp || !secpath_has_tunnel(skb->sp, 0);
970
971 pol->curlft.use_time = (unsigned long)xtime.tv_sec;
972
973 if (pol->action == XFRM_POLICY_ALLOW) {
974 struct sec_path *sp;
975 static struct sec_path dummy;
976 int i, k;
977
978 if ((sp = skb->sp) == NULL)
979 sp = &dummy;
980
981 /* For each tunnel xfrm, find the first matching tmpl.
982 * For each tmpl before that, find corresponding xfrm.
983 * Order is _important_. Later we will implement
984 * some barriers, but at the moment barriers
985 * are implied between each two transformations.
986 */
987 for (i = pol->xfrm_nr-1, k = 0; i >= 0; i--) {
988 k = xfrm_policy_ok(pol->xfrm_vec+i, sp, k, family);
989 if (k < 0)
990 goto reject;
991 }
992
993 if (secpath_has_tunnel(sp, k))
994 goto reject;
995
996 xfrm_pol_put(pol);
997 return 1;
998 }
999
1000reject:
1001 xfrm_pol_put(pol);
1002 return 0;
1003}
1004EXPORT_SYMBOL(__xfrm_policy_check);
1005
1006int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
1007{
1008 struct flowi fl;
1009
1010 if (_decode_session(skb, &fl, family) < 0)
1011 return 0;
1012
1013 return xfrm_lookup(&skb->dst, &fl, NULL, 0) == 0;
1014}
1015EXPORT_SYMBOL(__xfrm_route_forward);
1016
1017/* Optimize later using cookies and generation ids. */
1018
1019static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
1020{
1021 if (!stale_bundle(dst))
1022 return dst;
1023
1024 return NULL;
1025}
1026
1027static int stale_bundle(struct dst_entry *dst)
1028{
1029 return !xfrm_bundle_ok((struct xfrm_dst *)dst, NULL, AF_UNSPEC);
1030}
1031
Herbert Xuaabc9762005-05-03 16:27:10 -07001032void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001033{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034 while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
1035 dst->dev = &loopback_dev;
1036 dev_hold(&loopback_dev);
1037 dev_put(dev);
1038 }
1039}
Herbert Xuaabc9762005-05-03 16:27:10 -07001040EXPORT_SYMBOL(xfrm_dst_ifdown);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001041
1042static void xfrm_link_failure(struct sk_buff *skb)
1043{
1044 /* Impossible. Such dst must be popped before reaches point of failure. */
1045 return;
1046}
1047
1048static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
1049{
1050 if (dst) {
1051 if (dst->obsolete) {
1052 dst_release(dst);
1053 dst = NULL;
1054 }
1055 }
1056 return dst;
1057}
1058
1059static void xfrm_prune_bundles(int (*func)(struct dst_entry *))
1060{
1061 int i;
1062 struct xfrm_policy *pol;
1063 struct dst_entry *dst, **dstp, *gc_list = NULL;
1064
1065 read_lock_bh(&xfrm_policy_lock);
1066 for (i=0; i<2*XFRM_POLICY_MAX; i++) {
1067 for (pol = xfrm_policy_list[i]; pol; pol = pol->next) {
1068 write_lock(&pol->lock);
1069 dstp = &pol->bundles;
1070 while ((dst=*dstp) != NULL) {
1071 if (func(dst)) {
1072 *dstp = dst->next;
1073 dst->next = gc_list;
1074 gc_list = dst;
1075 } else {
1076 dstp = &dst->next;
1077 }
1078 }
1079 write_unlock(&pol->lock);
1080 }
1081 }
1082 read_unlock_bh(&xfrm_policy_lock);
1083
1084 while (gc_list) {
1085 dst = gc_list;
1086 gc_list = dst->next;
1087 dst_free(dst);
1088 }
1089}
1090
1091static int unused_bundle(struct dst_entry *dst)
1092{
1093 return !atomic_read(&dst->__refcnt);
1094}
1095
1096static void __xfrm_garbage_collect(void)
1097{
1098 xfrm_prune_bundles(unused_bundle);
1099}
1100
1101int xfrm_flush_bundles(void)
1102{
1103 xfrm_prune_bundles(stale_bundle);
1104 return 0;
1105}
1106
1107void xfrm_init_pmtu(struct dst_entry *dst)
1108{
1109 do {
1110 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1111 u32 pmtu, route_mtu_cached;
1112
1113 pmtu = dst_mtu(dst->child);
1114 xdst->child_mtu_cached = pmtu;
1115
1116 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
1117
1118 route_mtu_cached = dst_mtu(xdst->route);
1119 xdst->route_mtu_cached = route_mtu_cached;
1120
1121 if (pmtu > route_mtu_cached)
1122 pmtu = route_mtu_cached;
1123
1124 dst->metrics[RTAX_MTU-1] = pmtu;
1125 } while ((dst = dst->next));
1126}
1127
1128EXPORT_SYMBOL(xfrm_init_pmtu);
1129
1130/* Check that the bundle accepts the flow and its components are
1131 * still valid.
1132 */
1133
1134int xfrm_bundle_ok(struct xfrm_dst *first, struct flowi *fl, int family)
1135{
1136 struct dst_entry *dst = &first->u.dst;
1137 struct xfrm_dst *last;
1138 u32 mtu;
1139
Hideaki YOSHIFUJI92d63de2005-05-26 12:58:04 -07001140 if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141 (dst->dev && !netif_running(dst->dev)))
1142 return 0;
1143
1144 last = NULL;
1145
1146 do {
1147 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1148
1149 if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family))
1150 return 0;
1151 if (dst->xfrm->km.state != XFRM_STATE_VALID)
1152 return 0;
1153
1154 mtu = dst_mtu(dst->child);
1155 if (xdst->child_mtu_cached != mtu) {
1156 last = xdst;
1157 xdst->child_mtu_cached = mtu;
1158 }
1159
Hideaki YOSHIFUJI92d63de2005-05-26 12:58:04 -07001160 if (!dst_check(xdst->route, xdst->route_cookie))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161 return 0;
1162 mtu = dst_mtu(xdst->route);
1163 if (xdst->route_mtu_cached != mtu) {
1164 last = xdst;
1165 xdst->route_mtu_cached = mtu;
1166 }
1167
1168 dst = dst->child;
1169 } while (dst->xfrm);
1170
1171 if (likely(!last))
1172 return 1;
1173
1174 mtu = last->child_mtu_cached;
1175 for (;;) {
1176 dst = &last->u.dst;
1177
1178 mtu = xfrm_state_mtu(dst->xfrm, mtu);
1179 if (mtu > last->route_mtu_cached)
1180 mtu = last->route_mtu_cached;
1181 dst->metrics[RTAX_MTU-1] = mtu;
1182
1183 if (last == first)
1184 break;
1185
1186 last = last->u.next;
1187 last->child_mtu_cached = mtu;
1188 }
1189
1190 return 1;
1191}
1192
1193EXPORT_SYMBOL(xfrm_bundle_ok);
1194
1195/* Well... that's _TASK_. We need to scan through transformation
1196 * list and figure out what mss tcp should generate in order to
1197 * final datagram fit to mtu. Mama mia... :-)
1198 *
1199 * Apparently, some easy way exists, but we used to choose the most
1200 * bizarre ones. :-) So, raising Kalashnikov... tra-ta-ta.
1201 *
1202 * Consider this function as something like dark humour. :-)
1203 */
1204static int xfrm_get_mss(struct dst_entry *dst, u32 mtu)
1205{
1206 int res = mtu - dst->header_len;
1207
1208 for (;;) {
1209 struct dst_entry *d = dst;
1210 int m = res;
1211
1212 do {
1213 struct xfrm_state *x = d->xfrm;
1214 if (x) {
1215 spin_lock_bh(&x->lock);
1216 if (x->km.state == XFRM_STATE_VALID &&
1217 x->type && x->type->get_max_size)
1218 m = x->type->get_max_size(d->xfrm, m);
1219 else
1220 m += x->props.header_len;
1221 spin_unlock_bh(&x->lock);
1222 }
1223 } while ((d = d->child) != NULL);
1224
1225 if (m <= mtu)
1226 break;
1227 res -= (m - mtu);
1228 if (res < 88)
1229 return mtu;
1230 }
1231
1232 return res + dst->header_len;
1233}
1234
1235int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
1236{
1237 int err = 0;
1238 if (unlikely(afinfo == NULL))
1239 return -EINVAL;
1240 if (unlikely(afinfo->family >= NPROTO))
1241 return -EAFNOSUPPORT;
1242 write_lock(&xfrm_policy_afinfo_lock);
1243 if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
1244 err = -ENOBUFS;
1245 else {
1246 struct dst_ops *dst_ops = afinfo->dst_ops;
1247 if (likely(dst_ops->kmem_cachep == NULL))
1248 dst_ops->kmem_cachep = xfrm_dst_cache;
1249 if (likely(dst_ops->check == NULL))
1250 dst_ops->check = xfrm_dst_check;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251 if (likely(dst_ops->negative_advice == NULL))
1252 dst_ops->negative_advice = xfrm_negative_advice;
1253 if (likely(dst_ops->link_failure == NULL))
1254 dst_ops->link_failure = xfrm_link_failure;
1255 if (likely(dst_ops->get_mss == NULL))
1256 dst_ops->get_mss = xfrm_get_mss;
1257 if (likely(afinfo->garbage_collect == NULL))
1258 afinfo->garbage_collect = __xfrm_garbage_collect;
1259 xfrm_policy_afinfo[afinfo->family] = afinfo;
1260 }
1261 write_unlock(&xfrm_policy_afinfo_lock);
1262 return err;
1263}
1264EXPORT_SYMBOL(xfrm_policy_register_afinfo);
1265
1266int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
1267{
1268 int err = 0;
1269 if (unlikely(afinfo == NULL))
1270 return -EINVAL;
1271 if (unlikely(afinfo->family >= NPROTO))
1272 return -EAFNOSUPPORT;
1273 write_lock(&xfrm_policy_afinfo_lock);
1274 if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
1275 if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
1276 err = -EINVAL;
1277 else {
1278 struct dst_ops *dst_ops = afinfo->dst_ops;
1279 xfrm_policy_afinfo[afinfo->family] = NULL;
1280 dst_ops->kmem_cachep = NULL;
1281 dst_ops->check = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001282 dst_ops->negative_advice = NULL;
1283 dst_ops->link_failure = NULL;
1284 dst_ops->get_mss = NULL;
1285 afinfo->garbage_collect = NULL;
1286 }
1287 }
1288 write_unlock(&xfrm_policy_afinfo_lock);
1289 return err;
1290}
1291EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
1292
1293static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
1294{
1295 struct xfrm_policy_afinfo *afinfo;
1296 if (unlikely(family >= NPROTO))
1297 return NULL;
1298 read_lock(&xfrm_policy_afinfo_lock);
1299 afinfo = xfrm_policy_afinfo[family];
1300 if (likely(afinfo != NULL))
1301 read_lock(&afinfo->lock);
1302 read_unlock(&xfrm_policy_afinfo_lock);
1303 return afinfo;
1304}
1305
1306static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
1307{
1308 if (unlikely(afinfo == NULL))
1309 return;
1310 read_unlock(&afinfo->lock);
1311}
1312
1313static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
1314{
1315 switch (event) {
1316 case NETDEV_DOWN:
1317 xfrm_flush_bundles();
1318 }
1319 return NOTIFY_DONE;
1320}
1321
1322static struct notifier_block xfrm_dev_notifier = {
1323 xfrm_dev_event,
1324 NULL,
1325 0
1326};
1327
1328static void __init xfrm_policy_init(void)
1329{
1330 xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
1331 sizeof(struct xfrm_dst),
1332 0, SLAB_HWCACHE_ALIGN,
1333 NULL, NULL);
1334 if (!xfrm_dst_cache)
1335 panic("XFRM: failed to allocate xfrm_dst_cache\n");
1336
1337 INIT_WORK(&xfrm_policy_gc_work, xfrm_policy_gc_task, NULL);
1338 register_netdevice_notifier(&xfrm_dev_notifier);
1339}
1340
1341void __init xfrm_init(void)
1342{
1343 xfrm_state_init();
1344 xfrm_policy_init();
1345 xfrm_input_init();
1346}
1347