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[PATCH] cifs: Handle multiple response transact2 part 1 of 2
[linux-2.6/linux-mips.git] / net / xfrm / xfrm_policy.c
blob80828078733dd9771a3ee197364902b6b9f46c87
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/module.h>
26 #include <net/xfrm.h>
27 #include <net/ip.h>
28
29 DECLARE_MUTEX(xfrm_cfg_sem);
30 EXPORT_SYMBOL(xfrm_cfg_sem);
31
32 static DEFINE_RWLOCK(xfrm_policy_lock);
33
34 struct xfrm_policy *xfrm_policy_list[XFRM_POLICY_MAX*2];
35 EXPORT_SYMBOL(xfrm_policy_list);
36
37 static DEFINE_RWLOCK(xfrm_policy_afinfo_lock);
38 static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO];
39
40 static kmem_cache_t *xfrm_dst_cache;
41
42 static struct work_struct xfrm_policy_gc_work;
43 static struct list_head xfrm_policy_gc_list =
44 LIST_HEAD_INIT(xfrm_policy_gc_list);
45 static DEFINE_SPINLOCK(xfrm_policy_gc_lock);
46
47 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family);
48 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);
49
50 int 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 }
69 EXPORT_SYMBOL(xfrm_register_type);
70
71 int 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 }
90 EXPORT_SYMBOL(xfrm_unregister_type);
91
92 struct 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
99 retry:
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 }
121 EXPORT_SYMBOL(xfrm_get_type);
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 = xp->index & 7;
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 km_policy_expired(xp, dir, 1);
220 xfrm_policy_delete(xp, dir);
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(int 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 if (!policy->dead)
252 BUG();
253
254 if (policy->bundles)
255 BUG();
256
257 if (del_timer(&policy->timer))
258 BUG();
259
260 kfree(policy);
261 }
262 EXPORT_SYMBOL(__xfrm_policy_destroy);
263
264 static void xfrm_policy_gc_kill(struct xfrm_policy *policy)
265 {
266 struct dst_entry *dst;
267
268 while ((dst = policy->bundles) != NULL) {
269 policy->bundles = dst->next;
270 dst_free(dst);
271 }
272
273 if (del_timer(&policy->timer))
274 atomic_dec(&policy->refcnt);
275
276 if (atomic_read(&policy->refcnt) > 1)
277 flow_cache_flush();
278
279 xfrm_pol_put(policy);
280 }
281
282 static void xfrm_policy_gc_task(void *data)
283 {
284 struct xfrm_policy *policy;
285 struct list_head *entry, *tmp;
286 struct list_head gc_list = LIST_HEAD_INIT(gc_list);
287
288 spin_lock_bh(&xfrm_policy_gc_lock);
289 list_splice_init(&xfrm_policy_gc_list, &gc_list);
290 spin_unlock_bh(&xfrm_policy_gc_lock);
291
292 list_for_each_safe(entry, tmp, &gc_list) {
293 policy = list_entry(entry, struct xfrm_policy, list);
294 xfrm_policy_gc_kill(policy);
295 }
296 }
297
298 /* Rule must be locked. Release descentant resources, announce
299 * entry dead. The rule must be unlinked from lists to the moment.
300 */
301
302 static void xfrm_policy_kill(struct xfrm_policy *policy)
303 {
304 int dead;
305
306 write_lock_bh(&policy->lock);
307 dead = policy->dead;
308 policy->dead = 1;
309 write_unlock_bh(&policy->lock);
310
311 if (unlikely(dead)) {
312 WARN_ON(1);
313 return;
314 }
315
316 spin_lock(&xfrm_policy_gc_lock);
317 list_add(&policy->list, &xfrm_policy_gc_list);
318 spin_unlock(&xfrm_policy_gc_lock);
319
320 schedule_work(&xfrm_policy_gc_work);
321 }
322
323 /* Generate new index... KAME seems to generate them ordered by cost
324 * of an absolute inpredictability of ordering of rules. This will not pass. */
325 static u32 xfrm_gen_index(int dir)
326 {
327 u32 idx;
328 struct xfrm_policy *p;
329 static u32 idx_generator;
330
331 for (;;) {
332 idx = (idx_generator | dir);
333 idx_generator += 8;
334 if (idx == 0)
335 idx = 8;
336 for (p = xfrm_policy_list[dir]; p; p = p->next) {
337 if (p->index == idx)
338 break;
339 }
340 if (!p)
341 return idx;
342 }
343 }
344
345 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
346 {
347 struct xfrm_policy *pol, **p;
348 struct xfrm_policy *delpol = NULL;
349 struct xfrm_policy **newpos = NULL;
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 if (excl) {
355 write_unlock_bh(&xfrm_policy_lock);
356 return -EEXIST;
357 }
358 *p = pol->next;
359 delpol = pol;
360 if (policy->priority > pol->priority)
361 continue;
362 } else if (policy->priority >= pol->priority) {
363 p = &pol->next;
364 continue;
365 }
366 if (!newpos)
367 newpos = p;
368 if (delpol)
369 break;
370 p = &pol->next;
371 }
372 if (newpos)
373 p = newpos;
374 xfrm_pol_hold(policy);
375 policy->next = *p;
376 *p = policy;
377 atomic_inc(&flow_cache_genid);
378 policy->index = delpol ? delpol->index : xfrm_gen_index(dir);
379 policy->curlft.add_time = (unsigned long)xtime.tv_sec;
380 policy->curlft.use_time = 0;
381 if (!mod_timer(&policy->timer, jiffies + HZ))
382 xfrm_pol_hold(policy);
383 write_unlock_bh(&xfrm_policy_lock);
384
385 if (delpol) {
386 xfrm_policy_kill(delpol);
387 }
388 return 0;
389 }
390 EXPORT_SYMBOL(xfrm_policy_insert);
391
392 struct xfrm_policy *xfrm_policy_bysel(int dir, struct xfrm_selector *sel,
393 int delete)
394 {
395 struct xfrm_policy *pol, **p;
396
397 write_lock_bh(&xfrm_policy_lock);
398 for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL; p = &pol->next) {
399 if (memcmp(sel, &pol->selector, sizeof(*sel)) == 0) {
400 xfrm_pol_hold(pol);
401 if (delete)
402 *p = pol->next;
403 break;
404 }
405 }
406 write_unlock_bh(&xfrm_policy_lock);
407
408 if (pol && delete) {
409 atomic_inc(&flow_cache_genid);
410 xfrm_policy_kill(pol);
411 }
412 return pol;
413 }
414 EXPORT_SYMBOL(xfrm_policy_bysel);
415
416 struct xfrm_policy *xfrm_policy_byid(int dir, u32 id, int delete)
417 {
418 struct xfrm_policy *pol, **p;
419
420 write_lock_bh(&xfrm_policy_lock);
421 for (p = &xfrm_policy_list[id & 7]; (pol=*p)!=NULL; p = &pol->next) {
422 if (pol->index == id) {
423 xfrm_pol_hold(pol);
424 if (delete)
425 *p = pol->next;
426 break;
427 }
428 }
429 write_unlock_bh(&xfrm_policy_lock);
430
431 if (pol && delete) {
432 atomic_inc(&flow_cache_genid);
433 xfrm_policy_kill(pol);
434 }
435 return pol;
436 }
437 EXPORT_SYMBOL(xfrm_policy_byid);
438
439 void xfrm_policy_flush(void)
440 {
441 struct xfrm_policy *xp;
442 int dir;
443
444 write_lock_bh(&xfrm_policy_lock);
445 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
446 while ((xp = xfrm_policy_list[dir]) != NULL) {
447 xfrm_policy_list[dir] = xp->next;
448 write_unlock_bh(&xfrm_policy_lock);
449
450 xfrm_policy_kill(xp);
451
452 write_lock_bh(&xfrm_policy_lock);
453 }
454 }
455 atomic_inc(&flow_cache_genid);
456 write_unlock_bh(&xfrm_policy_lock);
457 }
458 EXPORT_SYMBOL(xfrm_policy_flush);
459
460 int xfrm_policy_walk(int (*func)(struct xfrm_policy *, int, int, void*),
461 void *data)
462 {
463 struct xfrm_policy *xp;
464 int dir;
465 int count = 0;
466 int error = 0;
467
468 read_lock_bh(&xfrm_policy_lock);
469 for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
470 for (xp = xfrm_policy_list[dir]; xp; xp = xp->next)
471 count++;
472 }
473
474 if (count == 0) {
475 error = -ENOENT;
476 goto out;
477 }
478
479 for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
480 for (xp = xfrm_policy_list[dir]; xp; xp = xp->next) {
481 error = func(xp, dir%XFRM_POLICY_MAX, --count, data);
482 if (error)
483 goto out;
484 }
485 }
486
487 out:
488 read_unlock_bh(&xfrm_policy_lock);
489 return error;
490 }
491 EXPORT_SYMBOL(xfrm_policy_walk);
492
493 /* Find policy to apply to this flow. */
494
495 static void xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
496 void **objp, atomic_t **obj_refp)
497 {
498 struct xfrm_policy *pol;
499
500 read_lock_bh(&xfrm_policy_lock);
501 for (pol = xfrm_policy_list[dir]; pol; pol = pol->next) {
502 struct xfrm_selector *sel = &pol->selector;
503 int match;
504
505 if (pol->family != family)
506 continue;
507
508 match = xfrm_selector_match(sel, fl, family);
509 if (match) {
510 xfrm_pol_hold(pol);
511 break;
512 }
513 }
514 read_unlock_bh(&xfrm_policy_lock);
515 if ((*objp = (void *) pol) != NULL)
516 *obj_refp = &pol->refcnt;
517 }
518
519 static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl)
520 {
521 struct xfrm_policy *pol;
522
523 read_lock_bh(&xfrm_policy_lock);
524 if ((pol = sk->sk_policy[dir]) != NULL) {
525 int match = xfrm_selector_match(&pol->selector, fl,
526 sk->sk_family);
527 if (match)
528 xfrm_pol_hold(pol);
529 else
530 pol = NULL;
531 }
532 read_unlock_bh(&xfrm_policy_lock);
533 return pol;
534 }
535
536 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
537 {
538 pol->next = xfrm_policy_list[dir];
539 xfrm_policy_list[dir] = pol;
540 xfrm_pol_hold(pol);
541 }
542
543 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
544 int dir)
545 {
546 struct xfrm_policy **polp;
547
548 for (polp = &xfrm_policy_list[dir];
549 *polp != NULL; polp = &(*polp)->next) {
550 if (*polp == pol) {
551 *polp = pol->next;
552 return pol;
553 }
554 }
555 return NULL;
556 }
557
558 void xfrm_policy_delete(struct xfrm_policy *pol, int dir)
559 {
560 write_lock_bh(&xfrm_policy_lock);
561 pol = __xfrm_policy_unlink(pol, dir);
562 write_unlock_bh(&xfrm_policy_lock);
563 if (pol) {
564 if (dir < XFRM_POLICY_MAX)
565 atomic_inc(&flow_cache_genid);
566 xfrm_policy_kill(pol);
567 }
568 }
569
570 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
571 {
572 struct xfrm_policy *old_pol;
573
574 write_lock_bh(&xfrm_policy_lock);
575 old_pol = sk->sk_policy[dir];
576 sk->sk_policy[dir] = pol;
577 if (pol) {
578 pol->curlft.add_time = (unsigned long)xtime.tv_sec;
579 pol->index = xfrm_gen_index(XFRM_POLICY_MAX+dir);
580 __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
581 }
582 if (old_pol)
583 __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
584 write_unlock_bh(&xfrm_policy_lock);
585
586 if (old_pol) {
587 xfrm_policy_kill(old_pol);
588 }
589 return 0;
590 }
591
592 static struct xfrm_policy *clone_policy(struct xfrm_policy *old, int dir)
593 {
594 struct xfrm_policy *newp = xfrm_policy_alloc(GFP_ATOMIC);
595
596 if (newp) {
597 newp->selector = old->selector;
598 newp->lft = old->lft;
599 newp->curlft = old->curlft;
600 newp->action = old->action;
601 newp->flags = old->flags;
602 newp->xfrm_nr = old->xfrm_nr;
603 newp->index = old->index;
604 memcpy(newp->xfrm_vec, old->xfrm_vec,
605 newp->xfrm_nr*sizeof(struct xfrm_tmpl));
606 write_lock_bh(&xfrm_policy_lock);
607 __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir);
608 write_unlock_bh(&xfrm_policy_lock);
609 xfrm_pol_put(newp);
610 }
611 return newp;
612 }
613
614 int __xfrm_sk_clone_policy(struct sock *sk)
615 {
616 struct xfrm_policy *p0 = sk->sk_policy[0],
617 *p1 = sk->sk_policy[1];
618
619 sk->sk_policy[0] = sk->sk_policy[1] = NULL;
620 if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL)
621 return -ENOMEM;
622 if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL)
623 return -ENOMEM;
624 return 0;
625 }
626
627 /* Resolve list of templates for the flow, given policy. */
628
629 static int
630 xfrm_tmpl_resolve(struct xfrm_policy *policy, struct flowi *fl,
631 struct xfrm_state **xfrm,
632 unsigned short family)
633 {
634 int nx;
635 int i, error;
636 xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
637 xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
638
639 for (nx=0, i = 0; i < policy->xfrm_nr; i++) {
640 struct xfrm_state *x;
641 xfrm_address_t *remote = daddr;
642 xfrm_address_t *local = saddr;
643 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
644
645 if (tmpl->mode) {
646 remote = &tmpl->id.daddr;
647 local = &tmpl->saddr;
648 }
649
650 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
651
652 if (x && x->km.state == XFRM_STATE_VALID) {
653 xfrm[nx++] = x;
654 daddr = remote;
655 saddr = local;
656 continue;
657 }
658 if (x) {
659 error = (x->km.state == XFRM_STATE_ERROR ?
660 -EINVAL : -EAGAIN);
661 xfrm_state_put(x);
662 }
663
664 if (!tmpl->optional)
665 goto fail;
666 }
667 return nx;
668
669 fail:
670 for (nx--; nx>=0; nx--)
671 xfrm_state_put(xfrm[nx]);
672 return error;
673 }
674
675 /* Check that the bundle accepts the flow and its components are
676 * still valid.
677 */
678
679 static struct dst_entry *
680 xfrm_find_bundle(struct flowi *fl, struct xfrm_policy *policy, unsigned short family)
681 {
682 struct dst_entry *x;
683 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
684 if (unlikely(afinfo == NULL))
685 return ERR_PTR(-EINVAL);
686 x = afinfo->find_bundle(fl, policy);
687 xfrm_policy_put_afinfo(afinfo);
688 return x;
689 }
690
691 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
692 * all the metrics... Shortly, bundle a bundle.
693 */
694
695 static int
696 xfrm_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
697 struct flowi *fl, struct dst_entry **dst_p,
698 unsigned short family)
699 {
700 int err;
701 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
702 if (unlikely(afinfo == NULL))
703 return -EINVAL;
704 err = afinfo->bundle_create(policy, xfrm, nx, fl, dst_p);
705 xfrm_policy_put_afinfo(afinfo);
706 return err;
707 }
708
709 static inline int policy_to_flow_dir(int dir)
710 {
711 if (XFRM_POLICY_IN == FLOW_DIR_IN &&
712 XFRM_POLICY_OUT == FLOW_DIR_OUT &&
713 XFRM_POLICY_FWD == FLOW_DIR_FWD)
714 return dir;
715 switch (dir) {
716 default:
717 case XFRM_POLICY_IN:
718 return FLOW_DIR_IN;
719 case XFRM_POLICY_OUT:
720 return FLOW_DIR_OUT;
721 case XFRM_POLICY_FWD:
722 return FLOW_DIR_FWD;
723 };
724 }
725
726 static int stale_bundle(struct dst_entry *dst);
727
728 /* Main function: finds/creates a bundle for given flow.
729 *
730 * At the moment we eat a raw IP route. Mostly to speed up lookups
731 * on interfaces with disabled IPsec.
732 */
733 int xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
734 struct sock *sk, int flags)
735 {
736 struct xfrm_policy *policy;
737 struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
738 struct dst_entry *dst, *dst_orig = *dst_p;
739 int nx = 0;
740 int err;
741 u32 genid;
742 u16 family = dst_orig->ops->family;
743 restart:
744 genid = atomic_read(&flow_cache_genid);
745 policy = NULL;
746 if (sk && sk->sk_policy[1])
747 policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
748
749 if (!policy) {
750 /* To accelerate a bit... */
751 if ((dst_orig->flags & DST_NOXFRM) || !xfrm_policy_list[XFRM_POLICY_OUT])
752 return 0;
753
754 policy = flow_cache_lookup(fl, family,
755 policy_to_flow_dir(XFRM_POLICY_OUT),
756 xfrm_policy_lookup);
757 }
758
759 if (!policy)
760 return 0;
761
762 policy->curlft.use_time = (unsigned long)xtime.tv_sec;
763
764 switch (policy->action) {
765 case XFRM_POLICY_BLOCK:
766 /* Prohibit the flow */
767 xfrm_pol_put(policy);
768 return -EPERM;
769
770 case XFRM_POLICY_ALLOW:
771 if (policy->xfrm_nr == 0) {
772 /* Flow passes not transformed. */
773 xfrm_pol_put(policy);
774 return 0;
775 }
776
777 /* Try to find matching bundle.
778 *
779 * LATER: help from flow cache. It is optional, this
780 * is required only for output policy.
781 */
782 dst = xfrm_find_bundle(fl, policy, family);
783 if (IS_ERR(dst)) {
784 xfrm_pol_put(policy);
785 return PTR_ERR(dst);
786 }
787
788 if (dst)
789 break;
790
791 nx = xfrm_tmpl_resolve(policy, fl, xfrm, family);
792
793 if (unlikely(nx<0)) {
794 err = nx;
795 if (err == -EAGAIN && flags) {
796 DECLARE_WAITQUEUE(wait, current);
797
798 add_wait_queue(&km_waitq, &wait);
799 set_current_state(TASK_INTERRUPTIBLE);
800 schedule();
801 set_current_state(TASK_RUNNING);
802 remove_wait_queue(&km_waitq, &wait);
803
804 nx = xfrm_tmpl_resolve(policy, fl, xfrm, family);
805
806 if (nx == -EAGAIN && signal_pending(current)) {
807 err = -ERESTART;
808 goto error;
809 }
810 if (nx == -EAGAIN ||
811 genid != atomic_read(&flow_cache_genid)) {
812 xfrm_pol_put(policy);
813 goto restart;
814 }
815 err = nx;
816 }
817 if (err < 0)
818 goto error;
819 }
820 if (nx == 0) {
821 /* Flow passes not transformed. */
822 xfrm_pol_put(policy);
823 return 0;
824 }
825
826 dst = dst_orig;
827 err = xfrm_bundle_create(policy, xfrm, nx, fl, &dst, family);
828
829 if (unlikely(err)) {
830 int i;
831 for (i=0; i<nx; i++)
832 xfrm_state_put(xfrm[i]);
833 goto error;
834 }
835
836 write_lock_bh(&policy->lock);
837 if (unlikely(policy->dead || stale_bundle(dst))) {
838 /* Wow! While we worked on resolving, this
839 * policy has gone. Retry. It is not paranoia,
840 * we just cannot enlist new bundle to dead object.
841 * We can't enlist stable bundles either.
842 */
843 write_unlock_bh(&policy->lock);
844
845 xfrm_pol_put(policy);
846 if (dst)
847 dst_free(dst);
848 goto restart;
849 }
850 dst->next = policy->bundles;
851 policy->bundles = dst;
852 dst_hold(dst);
853 write_unlock_bh(&policy->lock);
854 }
855 *dst_p = dst;
856 dst_release(dst_orig);
857 xfrm_pol_put(policy);
858 return 0;
859
860 error:
861 dst_release(dst_orig);
862 xfrm_pol_put(policy);
863 *dst_p = NULL;
864 return err;
865 }
866 EXPORT_SYMBOL(xfrm_lookup);
867
868 /* When skb is transformed back to its "native" form, we have to
869 * check policy restrictions. At the moment we make this in maximally
870 * stupid way. Shame on me. :-) Of course, connected sockets must
871 * have policy cached at them.
872 */
873
874 static inline int
875 xfrm_state_ok(struct xfrm_tmpl *tmpl, struct xfrm_state *x,
876 unsigned short family)
877 {
878 if (xfrm_state_kern(x))
879 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, family);
880 return x->id.proto == tmpl->id.proto &&
881 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
882 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
883 x->props.mode == tmpl->mode &&
884 (tmpl->aalgos & (1<<x->props.aalgo)) &&
885 !(x->props.mode && xfrm_state_addr_cmp(tmpl, x, family));
886 }
887
888 static inline int
889 xfrm_policy_ok(struct xfrm_tmpl *tmpl, struct sec_path *sp, int start,
890 unsigned short family)
891 {
892 int idx = start;
893
894 if (tmpl->optional) {
895 if (!tmpl->mode)
896 return start;
897 } else
898 start = -1;
899 for (; idx < sp->len; idx++) {
900 if (xfrm_state_ok(tmpl, sp->x[idx].xvec, family))
901 return ++idx;
902 if (sp->x[idx].xvec->props.mode)
903 break;
904 }
905 return start;
906 }
907
908 static int
909 _decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family)
910 {
911 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
912
913 if (unlikely(afinfo == NULL))
914 return -EAFNOSUPPORT;
915
916 afinfo->decode_session(skb, fl);
917 xfrm_policy_put_afinfo(afinfo);
918 return 0;
919 }
920
921 static inline int secpath_has_tunnel(struct sec_path *sp, int k)
922 {
923 for (; k < sp->len; k++) {
924 if (sp->x[k].xvec->props.mode)
925 return 1;
926 }
927
928 return 0;
929 }
930
931 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
932 unsigned short family)
933 {
934 struct xfrm_policy *pol;
935 struct flowi fl;
936
937 if (_decode_session(skb, &fl, family) < 0)
938 return 0;
939
940 /* First, check used SA against their selectors. */
941 if (skb->sp) {
942 int i;
943
944 for (i=skb->sp->len-1; i>=0; i--) {
945 struct sec_decap_state *xvec = &(skb->sp->x[i]);
946 if (!xfrm_selector_match(&xvec->xvec->sel, &fl, family))
947 return 0;
948
949 /* If there is a post_input processor, try running it */
950 if (xvec->xvec->type->post_input &&
951 (xvec->xvec->type->post_input)(xvec->xvec,
952 &(xvec->decap),
953 skb) != 0)
954 return 0;
955 }
956 }
957
958 pol = NULL;
959 if (sk && sk->sk_policy[dir])
960 pol = xfrm_sk_policy_lookup(sk, dir, &fl);
961
962 if (!pol)
963 pol = flow_cache_lookup(&fl, family,
964 policy_to_flow_dir(dir),
965 xfrm_policy_lookup);
966
967 if (!pol)
968 return !skb->sp || !secpath_has_tunnel(skb->sp, 0);
969
970 pol->curlft.use_time = (unsigned long)xtime.tv_sec;
971
972 if (pol->action == XFRM_POLICY_ALLOW) {
973 struct sec_path *sp;
974 static struct sec_path dummy;
975 int i, k;
976
977 if ((sp = skb->sp) == NULL)
978 sp = &dummy;
979
980 /* For each tunnel xfrm, find the first matching tmpl.
981 * For each tmpl before that, find corresponding xfrm.
982 * Order is _important_. Later we will implement
983 * some barriers, but at the moment barriers
984 * are implied between each two transformations.
985 */
986 for (i = pol->xfrm_nr-1, k = 0; i >= 0; i--) {
987 k = xfrm_policy_ok(pol->xfrm_vec+i, sp, k, family);
988 if (k < 0)
989 goto reject;
990 }
991
992 if (secpath_has_tunnel(sp, k))
993 goto reject;
994
995 xfrm_pol_put(pol);
996 return 1;
997 }
998
999 reject:
1000 xfrm_pol_put(pol);
1001 return 0;
1002 }
1003 EXPORT_SYMBOL(__xfrm_policy_check);
1004
1005 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
1006 {
1007 struct flowi fl;
1008
1009 if (_decode_session(skb, &fl, family) < 0)
1010 return 0;
1011
1012 return xfrm_lookup(&skb->dst, &fl, NULL, 0) == 0;
1013 }
1014 EXPORT_SYMBOL(__xfrm_route_forward);
1015
1016 /* Optimize later using cookies and generation ids. */
1017
1018 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
1019 {
1020 if (!stale_bundle(dst))
1021 return dst;
1022
1023 return NULL;
1024 }
1025
1026 static int stale_bundle(struct dst_entry *dst)
1027 {
1028 return !xfrm_bundle_ok((struct xfrm_dst *)dst, NULL, AF_UNSPEC);
1029 }
1030
1031 static void xfrm_dst_destroy(struct dst_entry *dst)
1032 {
1033 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1034
1035 dst_release(xdst->route);
1036
1037 if (!dst->xfrm)
1038 return;
1039 xfrm_state_put(dst->xfrm);
1040 dst->xfrm = NULL;
1041 }
1042
1043 static void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
1044 int unregister)
1045 {
1046 if (!unregister)
1047 return;
1048
1049 while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
1050 dst->dev = &loopback_dev;
1051 dev_hold(&loopback_dev);
1052 dev_put(dev);
1053 }
1054 }
1055
1056 static void xfrm_link_failure(struct sk_buff *skb)
1057 {
1058 /* Impossible. Such dst must be popped before reaches point of failure. */
1059 return;
1060 }
1061
1062 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
1063 {
1064 if (dst) {
1065 if (dst->obsolete) {
1066 dst_release(dst);
1067 dst = NULL;
1068 }
1069 }
1070 return dst;
1071 }
1072
1073 static void xfrm_prune_bundles(int (*func)(struct dst_entry *))
1074 {
1075 int i;
1076 struct xfrm_policy *pol;
1077 struct dst_entry *dst, **dstp, *gc_list = NULL;
1078
1079 read_lock_bh(&xfrm_policy_lock);
1080 for (i=0; i<2*XFRM_POLICY_MAX; i++) {
1081 for (pol = xfrm_policy_list[i]; pol; pol = pol->next) {
1082 write_lock(&pol->lock);
1083 dstp = &pol->bundles;
1084 while ((dst=*dstp) != NULL) {
1085 if (func(dst)) {
1086 *dstp = dst->next;
1087 dst->next = gc_list;
1088 gc_list = dst;
1089 } else {
1090 dstp = &dst->next;
1091 }
1092 }
1093 write_unlock(&pol->lock);
1094 }
1095 }
1096 read_unlock_bh(&xfrm_policy_lock);
1097
1098 while (gc_list) {
1099 dst = gc_list;
1100 gc_list = dst->next;
1101 dst_free(dst);
1102 }
1103 }
1104
1105 static int unused_bundle(struct dst_entry *dst)
1106 {
1107 return !atomic_read(&dst->__refcnt);
1108 }
1109
1110 static void __xfrm_garbage_collect(void)
1111 {
1112 xfrm_prune_bundles(unused_bundle);
1113 }
1114
1115 int xfrm_flush_bundles(void)
1116 {
1117 xfrm_prune_bundles(stale_bundle);
1118 return 0;
1119 }
1120
1121 void xfrm_init_pmtu(struct dst_entry *dst)
1122 {
1123 do {
1124 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1125 u32 pmtu, route_mtu_cached;
1126
1127 pmtu = dst_mtu(dst->child);
1128 xdst->child_mtu_cached = pmtu;
1129
1130 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
1131
1132 route_mtu_cached = dst_mtu(xdst->route);
1133 xdst->route_mtu_cached = route_mtu_cached;
1134
1135 if (pmtu > route_mtu_cached)
1136 pmtu = route_mtu_cached;
1137
1138 dst->metrics[RTAX_MTU-1] = pmtu;
1139 } while ((dst = dst->next));
1140 }
1141
1142 EXPORT_SYMBOL(xfrm_init_pmtu);
1143
1144 /* Check that the bundle accepts the flow and its components are
1145 * still valid.
1146 */
1147
1148 int xfrm_bundle_ok(struct xfrm_dst *first, struct flowi *fl, int family)
1149 {
1150 struct dst_entry *dst = &first->u.dst;
1151 struct xfrm_dst *last;
1152 u32 mtu;
1153
1154 if (!dst_check(dst->path, 0) ||
1155 (dst->dev && !netif_running(dst->dev)))
1156 return 0;
1157
1158 last = NULL;
1159
1160 do {
1161 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1162
1163 if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family))
1164 return 0;
1165 if (dst->xfrm->km.state != XFRM_STATE_VALID)
1166 return 0;
1167
1168 mtu = dst_mtu(dst->child);
1169 if (xdst->child_mtu_cached != mtu) {
1170 last = xdst;
1171 xdst->child_mtu_cached = mtu;
1172 }
1173
1174 if (!dst_check(xdst->route, 0))
1175 return 0;
1176 mtu = dst_mtu(xdst->route);
1177 if (xdst->route_mtu_cached != mtu) {
1178 last = xdst;
1179 xdst->route_mtu_cached = mtu;
1180 }
1181
1182 dst = dst->child;
1183 } while (dst->xfrm);
1184
1185 if (likely(!last))
1186 return 1;
1187
1188 mtu = last->child_mtu_cached;
1189 for (;;) {
1190 dst = &last->u.dst;
1191
1192 mtu = xfrm_state_mtu(dst->xfrm, mtu);
1193 if (mtu > last->route_mtu_cached)
1194 mtu = last->route_mtu_cached;
1195 dst->metrics[RTAX_MTU-1] = mtu;
1196
1197 if (last == first)
1198 break;
1199
1200 last = last->u.next;
1201 last->child_mtu_cached = mtu;
1202 }
1203
1204 return 1;
1205 }
1206
1207 EXPORT_SYMBOL(xfrm_bundle_ok);
1208
1209 /* Well... that's _TASK_. We need to scan through transformation
1210 * list and figure out what mss tcp should generate in order to
1211 * final datagram fit to mtu. Mama mia... :-)
1212 *
1213 * Apparently, some easy way exists, but we used to choose the most
1214 * bizarre ones. :-) So, raising Kalashnikov... tra-ta-ta.
1215 *
1216 * Consider this function as something like dark humour. :-)
1217 */
1218 static int xfrm_get_mss(struct dst_entry *dst, u32 mtu)
1219 {
1220 int res = mtu - dst->header_len;
1221
1222 for (;;) {
1223 struct dst_entry *d = dst;
1224 int m = res;
1225
1226 do {
1227 struct xfrm_state *x = d->xfrm;
1228 if (x) {
1229 spin_lock_bh(&x->lock);
1230 if (x->km.state == XFRM_STATE_VALID &&
1231 x->type && x->type->get_max_size)
1232 m = x->type->get_max_size(d->xfrm, m);
1233 else
1234 m += x->props.header_len;
1235 spin_unlock_bh(&x->lock);
1236 }
1237 } while ((d = d->child) != NULL);
1238
1239 if (m <= mtu)
1240 break;
1241 res -= (m - mtu);
1242 if (res < 88)
1243 return mtu;
1244 }
1245
1246 return res + dst->header_len;
1247 }
1248
1249 int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
1250 {
1251 int err = 0;
1252 if (unlikely(afinfo == NULL))
1253 return -EINVAL;
1254 if (unlikely(afinfo->family >= NPROTO))
1255 return -EAFNOSUPPORT;
1256 write_lock(&xfrm_policy_afinfo_lock);
1257 if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
1258 err = -ENOBUFS;
1259 else {
1260 struct dst_ops *dst_ops = afinfo->dst_ops;
1261 if (likely(dst_ops->kmem_cachep == NULL))
1262 dst_ops->kmem_cachep = xfrm_dst_cache;
1263 if (likely(dst_ops->check == NULL))
1264 dst_ops->check = xfrm_dst_check;
1265 if (likely(dst_ops->destroy == NULL))
1266 dst_ops->destroy = xfrm_dst_destroy;
1267 if (likely(dst_ops->ifdown == NULL))
1268 dst_ops->ifdown = xfrm_dst_ifdown;
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(dst_ops->get_mss == NULL))
1274 dst_ops->get_mss = xfrm_get_mss;
1275 if (likely(afinfo->garbage_collect == NULL))
1276 afinfo->garbage_collect = __xfrm_garbage_collect;
1277 xfrm_policy_afinfo[afinfo->family] = afinfo;
1278 }
1279 write_unlock(&xfrm_policy_afinfo_lock);
1280 return err;
1281 }
1282 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
1283
1284 int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
1285 {
1286 int err = 0;
1287 if (unlikely(afinfo == NULL))
1288 return -EINVAL;
1289 if (unlikely(afinfo->family >= NPROTO))
1290 return -EAFNOSUPPORT;
1291 write_lock(&xfrm_policy_afinfo_lock);
1292 if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
1293 if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
1294 err = -EINVAL;
1295 else {
1296 struct dst_ops *dst_ops = afinfo->dst_ops;
1297 xfrm_policy_afinfo[afinfo->family] = NULL;
1298 dst_ops->kmem_cachep = NULL;
1299 dst_ops->check = NULL;
1300 dst_ops->destroy = NULL;
1301 dst_ops->ifdown = NULL;
1302 dst_ops->negative_advice = NULL;
1303 dst_ops->link_failure = NULL;
1304 dst_ops->get_mss = NULL;
1305 afinfo->garbage_collect = NULL;
1306 }
1307 }
1308 write_unlock(&xfrm_policy_afinfo_lock);
1309 return err;
1310 }
1311 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
1312
1313 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
1314 {
1315 struct xfrm_policy_afinfo *afinfo;
1316 if (unlikely(family >= NPROTO))
1317 return NULL;
1318 read_lock(&xfrm_policy_afinfo_lock);
1319 afinfo = xfrm_policy_afinfo[family];
1320 if (likely(afinfo != NULL))
1321 read_lock(&afinfo->lock);
1322 read_unlock(&xfrm_policy_afinfo_lock);
1323 return afinfo;
1324 }
1325
1326 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
1327 {
1328 if (unlikely(afinfo == NULL))
1329 return;
1330 read_unlock(&afinfo->lock);
1331 }
1332
1333 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
1334 {
1335 switch (event) {
1336 case NETDEV_DOWN:
1337 xfrm_flush_bundles();
1338 }
1339 return NOTIFY_DONE;
1340 }
1341
1342 static struct notifier_block xfrm_dev_notifier = {
1343 xfrm_dev_event,
1344 NULL,
1345 0
1346 };
1347
1348 static void __init xfrm_policy_init(void)
1349 {
1350 xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
1351 sizeof(struct xfrm_dst),
1352 0, SLAB_HWCACHE_ALIGN,
1353 NULL, NULL);
1354 if (!xfrm_dst_cache)
1355 panic("XFRM: failed to allocate xfrm_dst_cache\n");
1356
1357 INIT_WORK(&xfrm_policy_gc_work, xfrm_policy_gc_task, NULL);
1358 register_netdevice_notifier(&xfrm_dev_notifier);
1359 }
1360
1361 void __init xfrm_init(void)
1362 {
1363 xfrm_state_init();
1364 xfrm_policy_init();
1365 xfrm_input_init();
1366 }
1367
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