Remove obsolete #include <linux/config.h>
[linux-2.6.git] / net / xfrm / xfrm_policy.c
1 /* 
2  * xfrm_policy.c
3  *
4  * Changes:
5  *      Mitsuru KANDA @USAGI
6  *      Kazunori MIYAZAWA @USAGI
7  *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
8  *              IPv6 support
9  *      Kazunori MIYAZAWA @USAGI
10  *      YOSHIFUJI Hideaki
11  *              Split up af-specific portion
12  *      Derek Atkins <derek@ihtfp.com>          Add the post_input processor
13  *
14  */
15
16 #include <linux/slab.h>
17 #include <linux/kmod.h>
18 #include <linux/list.h>
19 #include <linux/spinlock.h>
20 #include <linux/workqueue.h>
21 #include <linux/notifier.h>
22 #include <linux/netdevice.h>
23 #include <linux/netfilter.h>
24 #include <linux/module.h>
25 #include <net/xfrm.h>
26 #include <net/ip.h>
27
28 DEFINE_MUTEX(xfrm_cfg_mutex);
29 EXPORT_SYMBOL(xfrm_cfg_mutex);
30
31 static DEFINE_RWLOCK(xfrm_policy_lock);
32
33 struct xfrm_policy *xfrm_policy_list[XFRM_POLICY_MAX*2];
34 EXPORT_SYMBOL(xfrm_policy_list);
35
36 static DEFINE_RWLOCK(xfrm_policy_afinfo_lock);
37 static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO];
38
39 static kmem_cache_t *xfrm_dst_cache __read_mostly;
40
41 static struct work_struct xfrm_policy_gc_work;
42 static struct list_head xfrm_policy_gc_list =
43         LIST_HEAD_INIT(xfrm_policy_gc_list);
44 static DEFINE_SPINLOCK(xfrm_policy_gc_lock);
45
46 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family);
47 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);
48 static struct xfrm_policy_afinfo *xfrm_policy_lock_afinfo(unsigned int family);
49 static void xfrm_policy_unlock_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_lock_afinfo(family);
54         struct xfrm_type **typemap;
55         int err = 0;
56
57         if (unlikely(afinfo == NULL))
58                 return -EAFNOSUPPORT;
59         typemap = afinfo->type_map;
60
61         if (likely(typemap[type->proto] == NULL))
62                 typemap[type->proto] = type;
63         else
64                 err = -EEXIST;
65         xfrm_policy_unlock_afinfo(afinfo);
66         return err;
67 }
68 EXPORT_SYMBOL(xfrm_register_type);
69
70 int xfrm_unregister_type(struct xfrm_type *type, unsigned short family)
71 {
72         struct xfrm_policy_afinfo *afinfo = xfrm_policy_lock_afinfo(family);
73         struct xfrm_type **typemap;
74         int err = 0;
75
76         if (unlikely(afinfo == NULL))
77                 return -EAFNOSUPPORT;
78         typemap = afinfo->type_map;
79
80         if (unlikely(typemap[type->proto] != type))
81                 err = -ENOENT;
82         else
83                 typemap[type->proto] = NULL;
84         xfrm_policy_unlock_afinfo(afinfo);
85         return err;
86 }
87 EXPORT_SYMBOL(xfrm_unregister_type);
88
89 struct xfrm_type *xfrm_get_type(u8 proto, unsigned short family)
90 {
91         struct xfrm_policy_afinfo *afinfo;
92         struct xfrm_type **typemap;
93         struct xfrm_type *type;
94         int modload_attempted = 0;
95
96 retry:
97         afinfo = xfrm_policy_get_afinfo(family);
98         if (unlikely(afinfo == NULL))
99                 return NULL;
100         typemap = afinfo->type_map;
101
102         type = typemap[proto];
103         if (unlikely(type && !try_module_get(type->owner)))
104                 type = NULL;
105         if (!type && !modload_attempted) {
106                 xfrm_policy_put_afinfo(afinfo);
107                 request_module("xfrm-type-%d-%d",
108                                (int) family, (int) proto);
109                 modload_attempted = 1;
110                 goto retry;
111         }
112
113         xfrm_policy_put_afinfo(afinfo);
114         return type;
115 }
116
117 int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl, 
118                     unsigned short family)
119 {
120         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
121         int err = 0;
122
123         if (unlikely(afinfo == NULL))
124                 return -EAFNOSUPPORT;
125
126         if (likely(afinfo->dst_lookup != NULL))
127                 err = afinfo->dst_lookup(dst, fl);
128         else
129                 err = -EINVAL;
130         xfrm_policy_put_afinfo(afinfo);
131         return err;
132 }
133 EXPORT_SYMBOL(xfrm_dst_lookup);
134
135 void xfrm_put_type(struct xfrm_type *type)
136 {
137         module_put(type->owner);
138 }
139
140 int xfrm_register_mode(struct xfrm_mode *mode, int family)
141 {
142         struct xfrm_policy_afinfo *afinfo;
143         struct xfrm_mode **modemap;
144         int err;
145
146         if (unlikely(mode->encap >= XFRM_MODE_MAX))
147                 return -EINVAL;
148
149         afinfo = xfrm_policy_lock_afinfo(family);
150         if (unlikely(afinfo == NULL))
151                 return -EAFNOSUPPORT;
152
153         err = -EEXIST;
154         modemap = afinfo->mode_map;
155         if (likely(modemap[mode->encap] == NULL)) {
156                 modemap[mode->encap] = mode;
157                 err = 0;
158         }
159
160         xfrm_policy_unlock_afinfo(afinfo);
161         return err;
162 }
163 EXPORT_SYMBOL(xfrm_register_mode);
164
165 int xfrm_unregister_mode(struct xfrm_mode *mode, int family)
166 {
167         struct xfrm_policy_afinfo *afinfo;
168         struct xfrm_mode **modemap;
169         int err;
170
171         if (unlikely(mode->encap >= XFRM_MODE_MAX))
172                 return -EINVAL;
173
174         afinfo = xfrm_policy_lock_afinfo(family);
175         if (unlikely(afinfo == NULL))
176                 return -EAFNOSUPPORT;
177
178         err = -ENOENT;
179         modemap = afinfo->mode_map;
180         if (likely(modemap[mode->encap] == mode)) {
181                 modemap[mode->encap] = NULL;
182                 err = 0;
183         }
184
185         xfrm_policy_unlock_afinfo(afinfo);
186         return err;
187 }
188 EXPORT_SYMBOL(xfrm_unregister_mode);
189
190 struct xfrm_mode *xfrm_get_mode(unsigned int encap, int family)
191 {
192         struct xfrm_policy_afinfo *afinfo;
193         struct xfrm_mode *mode;
194         int modload_attempted = 0;
195
196         if (unlikely(encap >= XFRM_MODE_MAX))
197                 return NULL;
198
199 retry:
200         afinfo = xfrm_policy_get_afinfo(family);
201         if (unlikely(afinfo == NULL))
202                 return NULL;
203
204         mode = afinfo->mode_map[encap];
205         if (unlikely(mode && !try_module_get(mode->owner)))
206                 mode = NULL;
207         if (!mode && !modload_attempted) {
208                 xfrm_policy_put_afinfo(afinfo);
209                 request_module("xfrm-mode-%d-%d", family, encap);
210                 modload_attempted = 1;
211                 goto retry;
212         }
213
214         xfrm_policy_put_afinfo(afinfo);
215         return mode;
216 }
217
218 void xfrm_put_mode(struct xfrm_mode *mode)
219 {
220         module_put(mode->owner);
221 }
222
223 static inline unsigned long make_jiffies(long secs)
224 {
225         if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
226                 return MAX_SCHEDULE_TIMEOUT-1;
227         else
228                 return secs*HZ;
229 }
230
231 static void xfrm_policy_timer(unsigned long data)
232 {
233         struct xfrm_policy *xp = (struct xfrm_policy*)data;
234         unsigned long now = (unsigned long)xtime.tv_sec;
235         long next = LONG_MAX;
236         int warn = 0;
237         int dir;
238
239         read_lock(&xp->lock);
240
241         if (xp->dead)
242                 goto out;
243
244         dir = xfrm_policy_id2dir(xp->index);
245
246         if (xp->lft.hard_add_expires_seconds) {
247                 long tmo = xp->lft.hard_add_expires_seconds +
248                         xp->curlft.add_time - now;
249                 if (tmo <= 0)
250                         goto expired;
251                 if (tmo < next)
252                         next = tmo;
253         }
254         if (xp->lft.hard_use_expires_seconds) {
255                 long tmo = xp->lft.hard_use_expires_seconds +
256                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
257                 if (tmo <= 0)
258                         goto expired;
259                 if (tmo < next)
260                         next = tmo;
261         }
262         if (xp->lft.soft_add_expires_seconds) {
263                 long tmo = xp->lft.soft_add_expires_seconds +
264                         xp->curlft.add_time - now;
265                 if (tmo <= 0) {
266                         warn = 1;
267                         tmo = XFRM_KM_TIMEOUT;
268                 }
269                 if (tmo < next)
270                         next = tmo;
271         }
272         if (xp->lft.soft_use_expires_seconds) {
273                 long tmo = xp->lft.soft_use_expires_seconds +
274                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
275                 if (tmo <= 0) {
276                         warn = 1;
277                         tmo = XFRM_KM_TIMEOUT;
278                 }
279                 if (tmo < next)
280                         next = tmo;
281         }
282
283         if (warn)
284                 km_policy_expired(xp, dir, 0, 0);
285         if (next != LONG_MAX &&
286             !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
287                 xfrm_pol_hold(xp);
288
289 out:
290         read_unlock(&xp->lock);
291         xfrm_pol_put(xp);
292         return;
293
294 expired:
295         read_unlock(&xp->lock);
296         if (!xfrm_policy_delete(xp, dir))
297                 km_policy_expired(xp, dir, 1, 0);
298         xfrm_pol_put(xp);
299 }
300
301
302 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
303  * SPD calls.
304  */
305
306 struct xfrm_policy *xfrm_policy_alloc(gfp_t gfp)
307 {
308         struct xfrm_policy *policy;
309
310         policy = kmalloc(sizeof(struct xfrm_policy), gfp);
311
312         if (policy) {
313                 memset(policy, 0, sizeof(struct xfrm_policy));
314                 atomic_set(&policy->refcnt, 1);
315                 rwlock_init(&policy->lock);
316                 init_timer(&policy->timer);
317                 policy->timer.data = (unsigned long)policy;
318                 policy->timer.function = xfrm_policy_timer;
319         }
320         return policy;
321 }
322 EXPORT_SYMBOL(xfrm_policy_alloc);
323
324 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
325
326 void __xfrm_policy_destroy(struct xfrm_policy *policy)
327 {
328         BUG_ON(!policy->dead);
329
330         BUG_ON(policy->bundles);
331
332         if (del_timer(&policy->timer))
333                 BUG();
334
335         security_xfrm_policy_free(policy);
336         kfree(policy);
337 }
338 EXPORT_SYMBOL(__xfrm_policy_destroy);
339
340 static void xfrm_policy_gc_kill(struct xfrm_policy *policy)
341 {
342         struct dst_entry *dst;
343
344         while ((dst = policy->bundles) != NULL) {
345                 policy->bundles = dst->next;
346                 dst_free(dst);
347         }
348
349         if (del_timer(&policy->timer))
350                 atomic_dec(&policy->refcnt);
351
352         if (atomic_read(&policy->refcnt) > 1)
353                 flow_cache_flush();
354
355         xfrm_pol_put(policy);
356 }
357
358 static void xfrm_policy_gc_task(void *data)
359 {
360         struct xfrm_policy *policy;
361         struct list_head *entry, *tmp;
362         struct list_head gc_list = LIST_HEAD_INIT(gc_list);
363
364         spin_lock_bh(&xfrm_policy_gc_lock);
365         list_splice_init(&xfrm_policy_gc_list, &gc_list);
366         spin_unlock_bh(&xfrm_policy_gc_lock);
367
368         list_for_each_safe(entry, tmp, &gc_list) {
369                 policy = list_entry(entry, struct xfrm_policy, list);
370                 xfrm_policy_gc_kill(policy);
371         }
372 }
373
374 /* Rule must be locked. Release descentant resources, announce
375  * entry dead. The rule must be unlinked from lists to the moment.
376  */
377
378 static void xfrm_policy_kill(struct xfrm_policy *policy)
379 {
380         int dead;
381
382         write_lock_bh(&policy->lock);
383         dead = policy->dead;
384         policy->dead = 1;
385         write_unlock_bh(&policy->lock);
386
387         if (unlikely(dead)) {
388                 WARN_ON(1);
389                 return;
390         }
391
392         spin_lock(&xfrm_policy_gc_lock);
393         list_add(&policy->list, &xfrm_policy_gc_list);
394         spin_unlock(&xfrm_policy_gc_lock);
395
396         schedule_work(&xfrm_policy_gc_work);
397 }
398
399 /* Generate new index... KAME seems to generate them ordered by cost
400  * of an absolute inpredictability of ordering of rules. This will not pass. */
401 static u32 xfrm_gen_index(int dir)
402 {
403         u32 idx;
404         struct xfrm_policy *p;
405         static u32 idx_generator;
406
407         for (;;) {
408                 idx = (idx_generator | dir);
409                 idx_generator += 8;
410                 if (idx == 0)
411                         idx = 8;
412                 for (p = xfrm_policy_list[dir]; p; p = p->next) {
413                         if (p->index == idx)
414                                 break;
415                 }
416                 if (!p)
417                         return idx;
418         }
419 }
420
421 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
422 {
423         struct xfrm_policy *pol, **p;
424         struct xfrm_policy *delpol = NULL;
425         struct xfrm_policy **newpos = NULL;
426         struct dst_entry *gc_list;
427
428         write_lock_bh(&xfrm_policy_lock);
429         for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL;) {
430                 if (!delpol && memcmp(&policy->selector, &pol->selector, sizeof(pol->selector)) == 0 &&
431                     xfrm_sec_ctx_match(pol->security, policy->security)) {
432                         if (excl) {
433                                 write_unlock_bh(&xfrm_policy_lock);
434                                 return -EEXIST;
435                         }
436                         *p = pol->next;
437                         delpol = pol;
438                         if (policy->priority > pol->priority)
439                                 continue;
440                 } else if (policy->priority >= pol->priority) {
441                         p = &pol->next;
442                         continue;
443                 }
444                 if (!newpos)
445                         newpos = p;
446                 if (delpol)
447                         break;
448                 p = &pol->next;
449         }
450         if (newpos)
451                 p = newpos;
452         xfrm_pol_hold(policy);
453         policy->next = *p;
454         *p = policy;
455         atomic_inc(&flow_cache_genid);
456         policy->index = delpol ? delpol->index : xfrm_gen_index(dir);
457         policy->curlft.add_time = (unsigned long)xtime.tv_sec;
458         policy->curlft.use_time = 0;
459         if (!mod_timer(&policy->timer, jiffies + HZ))
460                 xfrm_pol_hold(policy);
461         write_unlock_bh(&xfrm_policy_lock);
462
463         if (delpol)
464                 xfrm_policy_kill(delpol);
465
466         read_lock_bh(&xfrm_policy_lock);
467         gc_list = NULL;
468         for (policy = policy->next; policy; policy = policy->next) {
469                 struct dst_entry *dst;
470
471                 write_lock(&policy->lock);
472                 dst = policy->bundles;
473                 if (dst) {
474                         struct dst_entry *tail = dst;
475                         while (tail->next)
476                                 tail = tail->next;
477                         tail->next = gc_list;
478                         gc_list = dst;
479
480                         policy->bundles = NULL;
481                 }
482                 write_unlock(&policy->lock);
483         }
484         read_unlock_bh(&xfrm_policy_lock);
485
486         while (gc_list) {
487                 struct dst_entry *dst = gc_list;
488
489                 gc_list = dst->next;
490                 dst_free(dst);
491         }
492
493         return 0;
494 }
495 EXPORT_SYMBOL(xfrm_policy_insert);
496
497 struct xfrm_policy *xfrm_policy_bysel_ctx(int dir, struct xfrm_selector *sel,
498                                           struct xfrm_sec_ctx *ctx, int delete)
499 {
500         struct xfrm_policy *pol, **p;
501
502         write_lock_bh(&xfrm_policy_lock);
503         for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL; p = &pol->next) {
504                 if ((memcmp(sel, &pol->selector, sizeof(*sel)) == 0) &&
505                     (xfrm_sec_ctx_match(ctx, pol->security))) {
506                         xfrm_pol_hold(pol);
507                         if (delete)
508                                 *p = pol->next;
509                         break;
510                 }
511         }
512         write_unlock_bh(&xfrm_policy_lock);
513
514         if (pol && delete) {
515                 atomic_inc(&flow_cache_genid);
516                 xfrm_policy_kill(pol);
517         }
518         return pol;
519 }
520 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
521
522 struct xfrm_policy *xfrm_policy_byid(int dir, u32 id, int delete)
523 {
524         struct xfrm_policy *pol, **p;
525
526         write_lock_bh(&xfrm_policy_lock);
527         for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL; p = &pol->next) {
528                 if (pol->index == id) {
529                         xfrm_pol_hold(pol);
530                         if (delete)
531                                 *p = pol->next;
532                         break;
533                 }
534         }
535         write_unlock_bh(&xfrm_policy_lock);
536
537         if (pol && delete) {
538                 atomic_inc(&flow_cache_genid);
539                 xfrm_policy_kill(pol);
540         }
541         return pol;
542 }
543 EXPORT_SYMBOL(xfrm_policy_byid);
544
545 void xfrm_policy_flush(void)
546 {
547         struct xfrm_policy *xp;
548         int dir;
549
550         write_lock_bh(&xfrm_policy_lock);
551         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
552                 while ((xp = xfrm_policy_list[dir]) != NULL) {
553                         xfrm_policy_list[dir] = xp->next;
554                         write_unlock_bh(&xfrm_policy_lock);
555
556                         xfrm_policy_kill(xp);
557
558                         write_lock_bh(&xfrm_policy_lock);
559                 }
560         }
561         atomic_inc(&flow_cache_genid);
562         write_unlock_bh(&xfrm_policy_lock);
563 }
564 EXPORT_SYMBOL(xfrm_policy_flush);
565
566 int xfrm_policy_walk(int (*func)(struct xfrm_policy *, int, int, void*),
567                      void *data)
568 {
569         struct xfrm_policy *xp;
570         int dir;
571         int count = 0;
572         int error = 0;
573
574         read_lock_bh(&xfrm_policy_lock);
575         for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
576                 for (xp = xfrm_policy_list[dir]; xp; xp = xp->next)
577                         count++;
578         }
579
580         if (count == 0) {
581                 error = -ENOENT;
582                 goto out;
583         }
584
585         for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
586                 for (xp = xfrm_policy_list[dir]; xp; xp = xp->next) {
587                         error = func(xp, dir%XFRM_POLICY_MAX, --count, data);
588                         if (error)
589                                 goto out;
590                 }
591         }
592
593 out:
594         read_unlock_bh(&xfrm_policy_lock);
595         return error;
596 }
597 EXPORT_SYMBOL(xfrm_policy_walk);
598
599 /* Find policy to apply to this flow. */
600
601 static void xfrm_policy_lookup(struct flowi *fl, u32 sk_sid, u16 family, u8 dir,
602                                void **objp, atomic_t **obj_refp)
603 {
604         struct xfrm_policy *pol;
605
606         read_lock_bh(&xfrm_policy_lock);
607         for (pol = xfrm_policy_list[dir]; pol; pol = pol->next) {
608                 struct xfrm_selector *sel = &pol->selector;
609                 int match;
610
611                 if (pol->family != family)
612                         continue;
613
614                 match = xfrm_selector_match(sel, fl, family);
615
616                 if (match) {
617                         if (!security_xfrm_policy_lookup(pol, sk_sid, dir)) {
618                                 xfrm_pol_hold(pol);
619                                 break;
620                         }
621                 }
622         }
623         read_unlock_bh(&xfrm_policy_lock);
624         if ((*objp = (void *) pol) != NULL)
625                 *obj_refp = &pol->refcnt;
626 }
627
628 static inline int policy_to_flow_dir(int dir)
629 {
630         if (XFRM_POLICY_IN == FLOW_DIR_IN &&
631             XFRM_POLICY_OUT == FLOW_DIR_OUT &&
632             XFRM_POLICY_FWD == FLOW_DIR_FWD)
633                 return dir;
634         switch (dir) {
635         default:
636         case XFRM_POLICY_IN:
637                 return FLOW_DIR_IN;
638         case XFRM_POLICY_OUT:
639                 return FLOW_DIR_OUT;
640         case XFRM_POLICY_FWD:
641                 return FLOW_DIR_FWD;
642         };
643 }
644
645 static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl, u32 sk_sid)
646 {
647         struct xfrm_policy *pol;
648
649         read_lock_bh(&xfrm_policy_lock);
650         if ((pol = sk->sk_policy[dir]) != NULL) {
651                 int match = xfrm_selector_match(&pol->selector, fl,
652                                                 sk->sk_family);
653                 int err = 0;
654
655                 if (match)
656                   err = security_xfrm_policy_lookup(pol, sk_sid, policy_to_flow_dir(dir));
657
658                 if (match && !err)
659                         xfrm_pol_hold(pol);
660                 else
661                         pol = NULL;
662         }
663         read_unlock_bh(&xfrm_policy_lock);
664         return pol;
665 }
666
667 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
668 {
669         pol->next = xfrm_policy_list[dir];
670         xfrm_policy_list[dir] = pol;
671         xfrm_pol_hold(pol);
672 }
673
674 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
675                                                 int dir)
676 {
677         struct xfrm_policy **polp;
678
679         for (polp = &xfrm_policy_list[dir];
680              *polp != NULL; polp = &(*polp)->next) {
681                 if (*polp == pol) {
682                         *polp = pol->next;
683                         return pol;
684                 }
685         }
686         return NULL;
687 }
688
689 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
690 {
691         write_lock_bh(&xfrm_policy_lock);
692         pol = __xfrm_policy_unlink(pol, dir);
693         write_unlock_bh(&xfrm_policy_lock);
694         if (pol) {
695                 if (dir < XFRM_POLICY_MAX)
696                         atomic_inc(&flow_cache_genid);
697                 xfrm_policy_kill(pol);
698                 return 0;
699         }
700         return -ENOENT;
701 }
702 EXPORT_SYMBOL(xfrm_policy_delete);
703
704 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
705 {
706         struct xfrm_policy *old_pol;
707
708         write_lock_bh(&xfrm_policy_lock);
709         old_pol = sk->sk_policy[dir];
710         sk->sk_policy[dir] = pol;
711         if (pol) {
712                 pol->curlft.add_time = (unsigned long)xtime.tv_sec;
713                 pol->index = xfrm_gen_index(XFRM_POLICY_MAX+dir);
714                 __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
715         }
716         if (old_pol)
717                 __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
718         write_unlock_bh(&xfrm_policy_lock);
719
720         if (old_pol) {
721                 xfrm_policy_kill(old_pol);
722         }
723         return 0;
724 }
725
726 static struct xfrm_policy *clone_policy(struct xfrm_policy *old, int dir)
727 {
728         struct xfrm_policy *newp = xfrm_policy_alloc(GFP_ATOMIC);
729
730         if (newp) {
731                 newp->selector = old->selector;
732                 if (security_xfrm_policy_clone(old, newp)) {
733                         kfree(newp);
734                         return NULL;  /* ENOMEM */
735                 }
736                 newp->lft = old->lft;
737                 newp->curlft = old->curlft;
738                 newp->action = old->action;
739                 newp->flags = old->flags;
740                 newp->xfrm_nr = old->xfrm_nr;
741                 newp->index = old->index;
742                 memcpy(newp->xfrm_vec, old->xfrm_vec,
743                        newp->xfrm_nr*sizeof(struct xfrm_tmpl));
744                 write_lock_bh(&xfrm_policy_lock);
745                 __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir);
746                 write_unlock_bh(&xfrm_policy_lock);
747                 xfrm_pol_put(newp);
748         }
749         return newp;
750 }
751
752 int __xfrm_sk_clone_policy(struct sock *sk)
753 {
754         struct xfrm_policy *p0 = sk->sk_policy[0],
755                            *p1 = sk->sk_policy[1];
756
757         sk->sk_policy[0] = sk->sk_policy[1] = NULL;
758         if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL)
759                 return -ENOMEM;
760         if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL)
761                 return -ENOMEM;
762         return 0;
763 }
764
765 /* Resolve list of templates for the flow, given policy. */
766
767 static int
768 xfrm_tmpl_resolve(struct xfrm_policy *policy, struct flowi *fl,
769                   struct xfrm_state **xfrm,
770                   unsigned short family)
771 {
772         int nx;
773         int i, error;
774         xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
775         xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
776
777         for (nx=0, i = 0; i < policy->xfrm_nr; i++) {
778                 struct xfrm_state *x;
779                 xfrm_address_t *remote = daddr;
780                 xfrm_address_t *local  = saddr;
781                 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
782
783                 if (tmpl->mode) {
784                         remote = &tmpl->id.daddr;
785                         local = &tmpl->saddr;
786                 }
787
788                 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
789
790                 if (x && x->km.state == XFRM_STATE_VALID) {
791                         xfrm[nx++] = x;
792                         daddr = remote;
793                         saddr = local;
794                         continue;
795                 }
796                 if (x) {
797                         error = (x->km.state == XFRM_STATE_ERROR ?
798                                  -EINVAL : -EAGAIN);
799                         xfrm_state_put(x);
800                 }
801
802                 if (!tmpl->optional)
803                         goto fail;
804         }
805         return nx;
806
807 fail:
808         for (nx--; nx>=0; nx--)
809                 xfrm_state_put(xfrm[nx]);
810         return error;
811 }
812
813 /* Check that the bundle accepts the flow and its components are
814  * still valid.
815  */
816
817 static struct dst_entry *
818 xfrm_find_bundle(struct flowi *fl, struct xfrm_policy *policy, unsigned short family)
819 {
820         struct dst_entry *x;
821         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
822         if (unlikely(afinfo == NULL))
823                 return ERR_PTR(-EINVAL);
824         x = afinfo->find_bundle(fl, policy);
825         xfrm_policy_put_afinfo(afinfo);
826         return x;
827 }
828
829 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
830  * all the metrics... Shortly, bundle a bundle.
831  */
832
833 static int
834 xfrm_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
835                    struct flowi *fl, struct dst_entry **dst_p,
836                    unsigned short family)
837 {
838         int err;
839         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
840         if (unlikely(afinfo == NULL))
841                 return -EINVAL;
842         err = afinfo->bundle_create(policy, xfrm, nx, fl, dst_p);
843         xfrm_policy_put_afinfo(afinfo);
844         return err;
845 }
846
847
848 static int stale_bundle(struct dst_entry *dst);
849
850 /* Main function: finds/creates a bundle for given flow.
851  *
852  * At the moment we eat a raw IP route. Mostly to speed up lookups
853  * on interfaces with disabled IPsec.
854  */
855 int xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
856                 struct sock *sk, int flags)
857 {
858         struct xfrm_policy *policy;
859         struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
860         struct dst_entry *dst, *dst_orig = *dst_p;
861         int nx = 0;
862         int err;
863         u32 genid;
864         u16 family;
865         u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
866         u32 sk_sid = security_sk_sid(sk, fl, dir);
867 restart:
868         genid = atomic_read(&flow_cache_genid);
869         policy = NULL;
870         if (sk && sk->sk_policy[1])
871                 policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, sk_sid);
872
873         if (!policy) {
874                 /* To accelerate a bit...  */
875                 if ((dst_orig->flags & DST_NOXFRM) || !xfrm_policy_list[XFRM_POLICY_OUT])
876                         return 0;
877
878                 policy = flow_cache_lookup(fl, sk_sid, dst_orig->ops->family,
879                                            dir, xfrm_policy_lookup);
880         }
881
882         if (!policy)
883                 return 0;
884
885         family = dst_orig->ops->family;
886         policy->curlft.use_time = (unsigned long)xtime.tv_sec;
887
888         switch (policy->action) {
889         case XFRM_POLICY_BLOCK:
890                 /* Prohibit the flow */
891                 err = -EPERM;
892                 goto error;
893
894         case XFRM_POLICY_ALLOW:
895                 if (policy->xfrm_nr == 0) {
896                         /* Flow passes not transformed. */
897                         xfrm_pol_put(policy);
898                         return 0;
899                 }
900
901                 /* Try to find matching bundle.
902                  *
903                  * LATER: help from flow cache. It is optional, this
904                  * is required only for output policy.
905                  */
906                 dst = xfrm_find_bundle(fl, policy, family);
907                 if (IS_ERR(dst)) {
908                         err = PTR_ERR(dst);
909                         goto error;
910                 }
911
912                 if (dst)
913                         break;
914
915                 nx = xfrm_tmpl_resolve(policy, fl, xfrm, family);
916
917                 if (unlikely(nx<0)) {
918                         err = nx;
919                         if (err == -EAGAIN && flags) {
920                                 DECLARE_WAITQUEUE(wait, current);
921
922                                 add_wait_queue(&km_waitq, &wait);
923                                 set_current_state(TASK_INTERRUPTIBLE);
924                                 schedule();
925                                 set_current_state(TASK_RUNNING);
926                                 remove_wait_queue(&km_waitq, &wait);
927
928                                 nx = xfrm_tmpl_resolve(policy, fl, xfrm, family);
929
930                                 if (nx == -EAGAIN && signal_pending(current)) {
931                                         err = -ERESTART;
932                                         goto error;
933                                 }
934                                 if (nx == -EAGAIN ||
935                                     genid != atomic_read(&flow_cache_genid)) {
936                                         xfrm_pol_put(policy);
937                                         goto restart;
938                                 }
939                                 err = nx;
940                         }
941                         if (err < 0)
942                                 goto error;
943                 }
944                 if (nx == 0) {
945                         /* Flow passes not transformed. */
946                         xfrm_pol_put(policy);
947                         return 0;
948                 }
949
950                 dst = dst_orig;
951                 err = xfrm_bundle_create(policy, xfrm, nx, fl, &dst, family);
952
953                 if (unlikely(err)) {
954                         int i;
955                         for (i=0; i<nx; i++)
956                                 xfrm_state_put(xfrm[i]);
957                         goto error;
958                 }
959
960                 write_lock_bh(&policy->lock);
961                 if (unlikely(policy->dead || stale_bundle(dst))) {
962                         /* Wow! While we worked on resolving, this
963                          * policy has gone. Retry. It is not paranoia,
964                          * we just cannot enlist new bundle to dead object.
965                          * We can't enlist stable bundles either.
966                          */
967                         write_unlock_bh(&policy->lock);
968                         if (dst)
969                                 dst_free(dst);
970
971                         err = -EHOSTUNREACH;
972                         goto error;
973                 }
974                 dst->next = policy->bundles;
975                 policy->bundles = dst;
976                 dst_hold(dst);
977                 write_unlock_bh(&policy->lock);
978         }
979         *dst_p = dst;
980         dst_release(dst_orig);
981         xfrm_pol_put(policy);
982         return 0;
983
984 error:
985         dst_release(dst_orig);
986         xfrm_pol_put(policy);
987         *dst_p = NULL;
988         return err;
989 }
990 EXPORT_SYMBOL(xfrm_lookup);
991
992 /* When skb is transformed back to its "native" form, we have to
993  * check policy restrictions. At the moment we make this in maximally
994  * stupid way. Shame on me. :-) Of course, connected sockets must
995  * have policy cached at them.
996  */
997
998 static inline int
999 xfrm_state_ok(struct xfrm_tmpl *tmpl, struct xfrm_state *x, 
1000               unsigned short family)
1001 {
1002         if (xfrm_state_kern(x))
1003                 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, family);
1004         return  x->id.proto == tmpl->id.proto &&
1005                 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
1006                 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
1007                 x->props.mode == tmpl->mode &&
1008                 (tmpl->aalgos & (1<<x->props.aalgo)) &&
1009                 !(x->props.mode && xfrm_state_addr_cmp(tmpl, x, family));
1010 }
1011
1012 static inline int
1013 xfrm_policy_ok(struct xfrm_tmpl *tmpl, struct sec_path *sp, int start,
1014                unsigned short family)
1015 {
1016         int idx = start;
1017
1018         if (tmpl->optional) {
1019                 if (!tmpl->mode)
1020                         return start;
1021         } else
1022                 start = -1;
1023         for (; idx < sp->len; idx++) {
1024                 if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
1025                         return ++idx;
1026                 if (sp->xvec[idx]->props.mode)
1027                         break;
1028         }
1029         return start;
1030 }
1031
1032 int
1033 xfrm_decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family)
1034 {
1035         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1036
1037         if (unlikely(afinfo == NULL))
1038                 return -EAFNOSUPPORT;
1039
1040         afinfo->decode_session(skb, fl);
1041         xfrm_policy_put_afinfo(afinfo);
1042         return 0;
1043 }
1044 EXPORT_SYMBOL(xfrm_decode_session);
1045
1046 static inline int secpath_has_tunnel(struct sec_path *sp, int k)
1047 {
1048         for (; k < sp->len; k++) {
1049                 if (sp->xvec[k]->props.mode)
1050                         return 1;
1051         }
1052
1053         return 0;
1054 }
1055
1056 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, 
1057                         unsigned short family)
1058 {
1059         struct xfrm_policy *pol;
1060         struct flowi fl;
1061         u8 fl_dir = policy_to_flow_dir(dir);
1062         u32 sk_sid;
1063
1064         if (xfrm_decode_session(skb, &fl, family) < 0)
1065                 return 0;
1066         nf_nat_decode_session(skb, &fl, family);
1067
1068         sk_sid = security_sk_sid(sk, &fl, fl_dir);
1069
1070         /* First, check used SA against their selectors. */
1071         if (skb->sp) {
1072                 int i;
1073
1074                 for (i=skb->sp->len-1; i>=0; i--) {
1075                         struct xfrm_state *x = skb->sp->xvec[i];
1076                         if (!xfrm_selector_match(&x->sel, &fl, family))
1077                                 return 0;
1078                 }
1079         }
1080
1081         pol = NULL;
1082         if (sk && sk->sk_policy[dir])
1083                 pol = xfrm_sk_policy_lookup(sk, dir, &fl, sk_sid);
1084
1085         if (!pol)
1086                 pol = flow_cache_lookup(&fl, sk_sid, family, fl_dir,
1087                                         xfrm_policy_lookup);
1088
1089         if (!pol)
1090                 return !skb->sp || !secpath_has_tunnel(skb->sp, 0);
1091
1092         pol->curlft.use_time = (unsigned long)xtime.tv_sec;
1093
1094         if (pol->action == XFRM_POLICY_ALLOW) {
1095                 struct sec_path *sp;
1096                 static struct sec_path dummy;
1097                 int i, k;
1098
1099                 if ((sp = skb->sp) == NULL)
1100                         sp = &dummy;
1101
1102                 /* For each tunnel xfrm, find the first matching tmpl.
1103                  * For each tmpl before that, find corresponding xfrm.
1104                  * Order is _important_. Later we will implement
1105                  * some barriers, but at the moment barriers
1106                  * are implied between each two transformations.
1107                  */
1108                 for (i = pol->xfrm_nr-1, k = 0; i >= 0; i--) {
1109                         k = xfrm_policy_ok(pol->xfrm_vec+i, sp, k, family);
1110                         if (k < 0)
1111                                 goto reject;
1112                 }
1113
1114                 if (secpath_has_tunnel(sp, k))
1115                         goto reject;
1116
1117                 xfrm_pol_put(pol);
1118                 return 1;
1119         }
1120
1121 reject:
1122         xfrm_pol_put(pol);
1123         return 0;
1124 }
1125 EXPORT_SYMBOL(__xfrm_policy_check);
1126
1127 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
1128 {
1129         struct flowi fl;
1130
1131         if (xfrm_decode_session(skb, &fl, family) < 0)
1132                 return 0;
1133
1134         return xfrm_lookup(&skb->dst, &fl, NULL, 0) == 0;
1135 }
1136 EXPORT_SYMBOL(__xfrm_route_forward);
1137
1138 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
1139 {
1140         /* If it is marked obsolete, which is how we even get here,
1141          * then we have purged it from the policy bundle list and we
1142          * did that for a good reason.
1143          */
1144         return NULL;
1145 }
1146
1147 static int stale_bundle(struct dst_entry *dst)
1148 {
1149         return !xfrm_bundle_ok((struct xfrm_dst *)dst, NULL, AF_UNSPEC);
1150 }
1151
1152 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
1153 {
1154         while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
1155                 dst->dev = &loopback_dev;
1156                 dev_hold(&loopback_dev);
1157                 dev_put(dev);
1158         }
1159 }
1160 EXPORT_SYMBOL(xfrm_dst_ifdown);
1161
1162 static void xfrm_link_failure(struct sk_buff *skb)
1163 {
1164         /* Impossible. Such dst must be popped before reaches point of failure. */
1165         return;
1166 }
1167
1168 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
1169 {
1170         if (dst) {
1171                 if (dst->obsolete) {
1172                         dst_release(dst);
1173                         dst = NULL;
1174                 }
1175         }
1176         return dst;
1177 }
1178
1179 static void xfrm_prune_bundles(int (*func)(struct dst_entry *))
1180 {
1181         int i;
1182         struct xfrm_policy *pol;
1183         struct dst_entry *dst, **dstp, *gc_list = NULL;
1184
1185         read_lock_bh(&xfrm_policy_lock);
1186         for (i=0; i<2*XFRM_POLICY_MAX; i++) {
1187                 for (pol = xfrm_policy_list[i]; pol; pol = pol->next) {
1188                         write_lock(&pol->lock);
1189                         dstp = &pol->bundles;
1190                         while ((dst=*dstp) != NULL) {
1191                                 if (func(dst)) {
1192                                         *dstp = dst->next;
1193                                         dst->next = gc_list;
1194                                         gc_list = dst;
1195                                 } else {
1196                                         dstp = &dst->next;
1197                                 }
1198                         }
1199                         write_unlock(&pol->lock);
1200                 }
1201         }
1202         read_unlock_bh(&xfrm_policy_lock);
1203
1204         while (gc_list) {
1205                 dst = gc_list;
1206                 gc_list = dst->next;
1207                 dst_free(dst);
1208         }
1209 }
1210
1211 static int unused_bundle(struct dst_entry *dst)
1212 {
1213         return !atomic_read(&dst->__refcnt);
1214 }
1215
1216 static void __xfrm_garbage_collect(void)
1217 {
1218         xfrm_prune_bundles(unused_bundle);
1219 }
1220
1221 int xfrm_flush_bundles(void)
1222 {
1223         xfrm_prune_bundles(stale_bundle);
1224         return 0;
1225 }
1226
1227 static int always_true(struct dst_entry *dst)
1228 {
1229         return 1;
1230 }
1231
1232 void xfrm_flush_all_bundles(void)
1233 {
1234         xfrm_prune_bundles(always_true);
1235 }
1236
1237 void xfrm_init_pmtu(struct dst_entry *dst)
1238 {
1239         do {
1240                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1241                 u32 pmtu, route_mtu_cached;
1242
1243                 pmtu = dst_mtu(dst->child);
1244                 xdst->child_mtu_cached = pmtu;
1245
1246                 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
1247
1248                 route_mtu_cached = dst_mtu(xdst->route);
1249                 xdst->route_mtu_cached = route_mtu_cached;
1250
1251                 if (pmtu > route_mtu_cached)
1252                         pmtu = route_mtu_cached;
1253
1254                 dst->metrics[RTAX_MTU-1] = pmtu;
1255         } while ((dst = dst->next));
1256 }
1257
1258 EXPORT_SYMBOL(xfrm_init_pmtu);
1259
1260 /* Check that the bundle accepts the flow and its components are
1261  * still valid.
1262  */
1263
1264 int xfrm_bundle_ok(struct xfrm_dst *first, struct flowi *fl, int family)
1265 {
1266         struct dst_entry *dst = &first->u.dst;
1267         struct xfrm_dst *last;
1268         u32 mtu;
1269
1270         if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) ||
1271             (dst->dev && !netif_running(dst->dev)))
1272                 return 0;
1273
1274         last = NULL;
1275
1276         do {
1277                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1278
1279                 if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family))
1280                         return 0;
1281                 if (dst->xfrm->km.state != XFRM_STATE_VALID)
1282                         return 0;
1283
1284                 mtu = dst_mtu(dst->child);
1285                 if (xdst->child_mtu_cached != mtu) {
1286                         last = xdst;
1287                         xdst->child_mtu_cached = mtu;
1288                 }
1289
1290                 if (!dst_check(xdst->route, xdst->route_cookie))
1291                         return 0;
1292                 mtu = dst_mtu(xdst->route);
1293                 if (xdst->route_mtu_cached != mtu) {
1294                         last = xdst;
1295                         xdst->route_mtu_cached = mtu;
1296                 }
1297
1298                 dst = dst->child;
1299         } while (dst->xfrm);
1300
1301         if (likely(!last))
1302                 return 1;
1303
1304         mtu = last->child_mtu_cached;
1305         for (;;) {
1306                 dst = &last->u.dst;
1307
1308                 mtu = xfrm_state_mtu(dst->xfrm, mtu);
1309                 if (mtu > last->route_mtu_cached)
1310                         mtu = last->route_mtu_cached;
1311                 dst->metrics[RTAX_MTU-1] = mtu;
1312
1313                 if (last == first)
1314                         break;
1315
1316                 last = last->u.next;
1317                 last->child_mtu_cached = mtu;
1318         }
1319
1320         return 1;
1321 }
1322
1323 EXPORT_SYMBOL(xfrm_bundle_ok);
1324
1325 int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
1326 {
1327         int err = 0;
1328         if (unlikely(afinfo == NULL))
1329                 return -EINVAL;
1330         if (unlikely(afinfo->family >= NPROTO))
1331                 return -EAFNOSUPPORT;
1332         write_lock_bh(&xfrm_policy_afinfo_lock);
1333         if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
1334                 err = -ENOBUFS;
1335         else {
1336                 struct dst_ops *dst_ops = afinfo->dst_ops;
1337                 if (likely(dst_ops->kmem_cachep == NULL))
1338                         dst_ops->kmem_cachep = xfrm_dst_cache;
1339                 if (likely(dst_ops->check == NULL))
1340                         dst_ops->check = xfrm_dst_check;
1341                 if (likely(dst_ops->negative_advice == NULL))
1342                         dst_ops->negative_advice = xfrm_negative_advice;
1343                 if (likely(dst_ops->link_failure == NULL))
1344                         dst_ops->link_failure = xfrm_link_failure;
1345                 if (likely(afinfo->garbage_collect == NULL))
1346                         afinfo->garbage_collect = __xfrm_garbage_collect;
1347                 xfrm_policy_afinfo[afinfo->family] = afinfo;
1348         }
1349         write_unlock_bh(&xfrm_policy_afinfo_lock);
1350         return err;
1351 }
1352 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
1353
1354 int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
1355 {
1356         int err = 0;
1357         if (unlikely(afinfo == NULL))
1358                 return -EINVAL;
1359         if (unlikely(afinfo->family >= NPROTO))
1360                 return -EAFNOSUPPORT;
1361         write_lock_bh(&xfrm_policy_afinfo_lock);
1362         if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
1363                 if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
1364                         err = -EINVAL;
1365                 else {
1366                         struct dst_ops *dst_ops = afinfo->dst_ops;
1367                         xfrm_policy_afinfo[afinfo->family] = NULL;
1368                         dst_ops->kmem_cachep = NULL;
1369                         dst_ops->check = NULL;
1370                         dst_ops->negative_advice = NULL;
1371                         dst_ops->link_failure = NULL;
1372                         afinfo->garbage_collect = NULL;
1373                 }
1374         }
1375         write_unlock_bh(&xfrm_policy_afinfo_lock);
1376         return err;
1377 }
1378 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
1379
1380 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
1381 {
1382         struct xfrm_policy_afinfo *afinfo;
1383         if (unlikely(family >= NPROTO))
1384                 return NULL;
1385         read_lock(&xfrm_policy_afinfo_lock);
1386         afinfo = xfrm_policy_afinfo[family];
1387         if (unlikely(!afinfo))
1388                 read_unlock(&xfrm_policy_afinfo_lock);
1389         return afinfo;
1390 }
1391
1392 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
1393 {
1394         read_unlock(&xfrm_policy_afinfo_lock);
1395 }
1396
1397 static struct xfrm_policy_afinfo *xfrm_policy_lock_afinfo(unsigned int family)
1398 {
1399         struct xfrm_policy_afinfo *afinfo;
1400         if (unlikely(family >= NPROTO))
1401                 return NULL;
1402         write_lock_bh(&xfrm_policy_afinfo_lock);
1403         afinfo = xfrm_policy_afinfo[family];
1404         if (unlikely(!afinfo))
1405                 write_unlock_bh(&xfrm_policy_afinfo_lock);
1406         return afinfo;
1407 }
1408
1409 static void xfrm_policy_unlock_afinfo(struct xfrm_policy_afinfo *afinfo)
1410 {
1411         write_unlock_bh(&xfrm_policy_afinfo_lock);
1412 }
1413
1414 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
1415 {
1416         switch (event) {
1417         case NETDEV_DOWN:
1418                 xfrm_flush_bundles();
1419         }
1420         return NOTIFY_DONE;
1421 }
1422
1423 static struct notifier_block xfrm_dev_notifier = {
1424         xfrm_dev_event,
1425         NULL,
1426         0
1427 };
1428
1429 static void __init xfrm_policy_init(void)
1430 {
1431         xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
1432                                            sizeof(struct xfrm_dst),
1433                                            0, SLAB_HWCACHE_ALIGN,
1434                                            NULL, NULL);
1435         if (!xfrm_dst_cache)
1436                 panic("XFRM: failed to allocate xfrm_dst_cache\n");
1437
1438         INIT_WORK(&xfrm_policy_gc_work, xfrm_policy_gc_task, NULL);
1439         register_netdevice_notifier(&xfrm_dev_notifier);
1440 }
1441
1442 void __init xfrm_init(void)
1443 {
1444         xfrm_state_init();
1445         xfrm_policy_init();
1446         xfrm_input_init();
1447 }
1448