[XFRM]: Add XFRM_MODE_xxx for future use.
[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 = kzalloc(sizeof(struct xfrm_policy), gfp);
311
312         if (policy) {
313                 atomic_set(&policy->refcnt, 1);
314                 rwlock_init(&policy->lock);
315                 init_timer(&policy->timer);
316                 policy->timer.data = (unsigned long)policy;
317                 policy->timer.function = xfrm_policy_timer;
318         }
319         return policy;
320 }
321 EXPORT_SYMBOL(xfrm_policy_alloc);
322
323 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
324
325 void __xfrm_policy_destroy(struct xfrm_policy *policy)
326 {
327         BUG_ON(!policy->dead);
328
329         BUG_ON(policy->bundles);
330
331         if (del_timer(&policy->timer))
332                 BUG();
333
334         security_xfrm_policy_free(policy);
335         kfree(policy);
336 }
337 EXPORT_SYMBOL(__xfrm_policy_destroy);
338
339 static void xfrm_policy_gc_kill(struct xfrm_policy *policy)
340 {
341         struct dst_entry *dst;
342
343         while ((dst = policy->bundles) != NULL) {
344                 policy->bundles = dst->next;
345                 dst_free(dst);
346         }
347
348         if (del_timer(&policy->timer))
349                 atomic_dec(&policy->refcnt);
350
351         if (atomic_read(&policy->refcnt) > 1)
352                 flow_cache_flush();
353
354         xfrm_pol_put(policy);
355 }
356
357 static void xfrm_policy_gc_task(void *data)
358 {
359         struct xfrm_policy *policy;
360         struct list_head *entry, *tmp;
361         struct list_head gc_list = LIST_HEAD_INIT(gc_list);
362
363         spin_lock_bh(&xfrm_policy_gc_lock);
364         list_splice_init(&xfrm_policy_gc_list, &gc_list);
365         spin_unlock_bh(&xfrm_policy_gc_lock);
366
367         list_for_each_safe(entry, tmp, &gc_list) {
368                 policy = list_entry(entry, struct xfrm_policy, list);
369                 xfrm_policy_gc_kill(policy);
370         }
371 }
372
373 /* Rule must be locked. Release descentant resources, announce
374  * entry dead. The rule must be unlinked from lists to the moment.
375  */
376
377 static void xfrm_policy_kill(struct xfrm_policy *policy)
378 {
379         int dead;
380
381         write_lock_bh(&policy->lock);
382         dead = policy->dead;
383         policy->dead = 1;
384         write_unlock_bh(&policy->lock);
385
386         if (unlikely(dead)) {
387                 WARN_ON(1);
388                 return;
389         }
390
391         spin_lock(&xfrm_policy_gc_lock);
392         list_add(&policy->list, &xfrm_policy_gc_list);
393         spin_unlock(&xfrm_policy_gc_lock);
394
395         schedule_work(&xfrm_policy_gc_work);
396 }
397
398 /* Generate new index... KAME seems to generate them ordered by cost
399  * of an absolute inpredictability of ordering of rules. This will not pass. */
400 static u32 xfrm_gen_index(int dir)
401 {
402         u32 idx;
403         struct xfrm_policy *p;
404         static u32 idx_generator;
405
406         for (;;) {
407                 idx = (idx_generator | dir);
408                 idx_generator += 8;
409                 if (idx == 0)
410                         idx = 8;
411                 for (p = xfrm_policy_list[dir]; p; p = p->next) {
412                         if (p->index == idx)
413                                 break;
414                 }
415                 if (!p)
416                         return idx;
417         }
418 }
419
420 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
421 {
422         struct xfrm_policy *pol, **p;
423         struct xfrm_policy *delpol = NULL;
424         struct xfrm_policy **newpos = NULL;
425         struct dst_entry *gc_list;
426
427         write_lock_bh(&xfrm_policy_lock);
428         for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL;) {
429                 if (!delpol && memcmp(&policy->selector, &pol->selector, sizeof(pol->selector)) == 0 &&
430                     xfrm_sec_ctx_match(pol->security, policy->security)) {
431                         if (excl) {
432                                 write_unlock_bh(&xfrm_policy_lock);
433                                 return -EEXIST;
434                         }
435                         *p = pol->next;
436                         delpol = pol;
437                         if (policy->priority > pol->priority)
438                                 continue;
439                 } else if (policy->priority >= pol->priority) {
440                         p = &pol->next;
441                         continue;
442                 }
443                 if (!newpos)
444                         newpos = p;
445                 if (delpol)
446                         break;
447                 p = &pol->next;
448         }
449         if (newpos)
450                 p = newpos;
451         xfrm_pol_hold(policy);
452         policy->next = *p;
453         *p = policy;
454         atomic_inc(&flow_cache_genid);
455         policy->index = delpol ? delpol->index : xfrm_gen_index(dir);
456         policy->curlft.add_time = (unsigned long)xtime.tv_sec;
457         policy->curlft.use_time = 0;
458         if (!mod_timer(&policy->timer, jiffies + HZ))
459                 xfrm_pol_hold(policy);
460         write_unlock_bh(&xfrm_policy_lock);
461
462         if (delpol)
463                 xfrm_policy_kill(delpol);
464
465         read_lock_bh(&xfrm_policy_lock);
466         gc_list = NULL;
467         for (policy = policy->next; policy; policy = policy->next) {
468                 struct dst_entry *dst;
469
470                 write_lock(&policy->lock);
471                 dst = policy->bundles;
472                 if (dst) {
473                         struct dst_entry *tail = dst;
474                         while (tail->next)
475                                 tail = tail->next;
476                         tail->next = gc_list;
477                         gc_list = dst;
478
479                         policy->bundles = NULL;
480                 }
481                 write_unlock(&policy->lock);
482         }
483         read_unlock_bh(&xfrm_policy_lock);
484
485         while (gc_list) {
486                 struct dst_entry *dst = gc_list;
487
488                 gc_list = dst->next;
489                 dst_free(dst);
490         }
491
492         return 0;
493 }
494 EXPORT_SYMBOL(xfrm_policy_insert);
495
496 struct xfrm_policy *xfrm_policy_bysel_ctx(int dir, struct xfrm_selector *sel,
497                                           struct xfrm_sec_ctx *ctx, int delete)
498 {
499         struct xfrm_policy *pol, **p;
500
501         write_lock_bh(&xfrm_policy_lock);
502         for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL; p = &pol->next) {
503                 if ((memcmp(sel, &pol->selector, sizeof(*sel)) == 0) &&
504                     (xfrm_sec_ctx_match(ctx, pol->security))) {
505                         xfrm_pol_hold(pol);
506                         if (delete)
507                                 *p = pol->next;
508                         break;
509                 }
510         }
511         write_unlock_bh(&xfrm_policy_lock);
512
513         if (pol && delete) {
514                 atomic_inc(&flow_cache_genid);
515                 xfrm_policy_kill(pol);
516         }
517         return pol;
518 }
519 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
520
521 struct xfrm_policy *xfrm_policy_byid(int dir, u32 id, int delete)
522 {
523         struct xfrm_policy *pol, **p;
524
525         write_lock_bh(&xfrm_policy_lock);
526         for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL; p = &pol->next) {
527                 if (pol->index == id) {
528                         xfrm_pol_hold(pol);
529                         if (delete)
530                                 *p = pol->next;
531                         break;
532                 }
533         }
534         write_unlock_bh(&xfrm_policy_lock);
535
536         if (pol && delete) {
537                 atomic_inc(&flow_cache_genid);
538                 xfrm_policy_kill(pol);
539         }
540         return pol;
541 }
542 EXPORT_SYMBOL(xfrm_policy_byid);
543
544 void xfrm_policy_flush(void)
545 {
546         struct xfrm_policy *xp;
547         int dir;
548
549         write_lock_bh(&xfrm_policy_lock);
550         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
551                 while ((xp = xfrm_policy_list[dir]) != NULL) {
552                         xfrm_policy_list[dir] = xp->next;
553                         write_unlock_bh(&xfrm_policy_lock);
554
555                         xfrm_policy_kill(xp);
556
557                         write_lock_bh(&xfrm_policy_lock);
558                 }
559         }
560         atomic_inc(&flow_cache_genid);
561         write_unlock_bh(&xfrm_policy_lock);
562 }
563 EXPORT_SYMBOL(xfrm_policy_flush);
564
565 int xfrm_policy_walk(int (*func)(struct xfrm_policy *, int, int, void*),
566                      void *data)
567 {
568         struct xfrm_policy *xp;
569         int dir;
570         int count = 0;
571         int error = 0;
572
573         read_lock_bh(&xfrm_policy_lock);
574         for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
575                 for (xp = xfrm_policy_list[dir]; xp; xp = xp->next)
576                         count++;
577         }
578
579         if (count == 0) {
580                 error = -ENOENT;
581                 goto out;
582         }
583
584         for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
585                 for (xp = xfrm_policy_list[dir]; xp; xp = xp->next) {
586                         error = func(xp, dir%XFRM_POLICY_MAX, --count, data);
587                         if (error)
588                                 goto out;
589                 }
590         }
591
592 out:
593         read_unlock_bh(&xfrm_policy_lock);
594         return error;
595 }
596 EXPORT_SYMBOL(xfrm_policy_walk);
597
598 /* Find policy to apply to this flow. */
599
600 static void xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
601                                void **objp, atomic_t **obj_refp)
602 {
603         struct xfrm_policy *pol;
604
605         read_lock_bh(&xfrm_policy_lock);
606         for (pol = xfrm_policy_list[dir]; pol; pol = pol->next) {
607                 struct xfrm_selector *sel = &pol->selector;
608                 int match;
609
610                 if (pol->family != family)
611                         continue;
612
613                 match = xfrm_selector_match(sel, fl, family);
614
615                 if (match) {
616                         if (!security_xfrm_policy_lookup(pol, fl->secid, dir)) {
617                                 xfrm_pol_hold(pol);
618                                 break;
619                         }
620                 }
621         }
622         read_unlock_bh(&xfrm_policy_lock);
623         if ((*objp = (void *) pol) != NULL)
624                 *obj_refp = &pol->refcnt;
625 }
626
627 static inline int policy_to_flow_dir(int dir)
628 {
629         if (XFRM_POLICY_IN == FLOW_DIR_IN &&
630             XFRM_POLICY_OUT == FLOW_DIR_OUT &&
631             XFRM_POLICY_FWD == FLOW_DIR_FWD)
632                 return dir;
633         switch (dir) {
634         default:
635         case XFRM_POLICY_IN:
636                 return FLOW_DIR_IN;
637         case XFRM_POLICY_OUT:
638                 return FLOW_DIR_OUT;
639         case XFRM_POLICY_FWD:
640                 return FLOW_DIR_FWD;
641         };
642 }
643
644 static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl)
645 {
646         struct xfrm_policy *pol;
647
648         read_lock_bh(&xfrm_policy_lock);
649         if ((pol = sk->sk_policy[dir]) != NULL) {
650                 int match = xfrm_selector_match(&pol->selector, fl,
651                                                 sk->sk_family);
652                 int err = 0;
653
654                 if (match)
655                   err = security_xfrm_policy_lookup(pol, fl->secid, policy_to_flow_dir(dir));
656
657                 if (match && !err)
658                         xfrm_pol_hold(pol);
659                 else
660                         pol = NULL;
661         }
662         read_unlock_bh(&xfrm_policy_lock);
663         return pol;
664 }
665
666 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
667 {
668         pol->next = xfrm_policy_list[dir];
669         xfrm_policy_list[dir] = pol;
670         xfrm_pol_hold(pol);
671 }
672
673 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
674                                                 int dir)
675 {
676         struct xfrm_policy **polp;
677
678         for (polp = &xfrm_policy_list[dir];
679              *polp != NULL; polp = &(*polp)->next) {
680                 if (*polp == pol) {
681                         *polp = pol->next;
682                         return pol;
683                 }
684         }
685         return NULL;
686 }
687
688 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
689 {
690         write_lock_bh(&xfrm_policy_lock);
691         pol = __xfrm_policy_unlink(pol, dir);
692         write_unlock_bh(&xfrm_policy_lock);
693         if (pol) {
694                 if (dir < XFRM_POLICY_MAX)
695                         atomic_inc(&flow_cache_genid);
696                 xfrm_policy_kill(pol);
697                 return 0;
698         }
699         return -ENOENT;
700 }
701 EXPORT_SYMBOL(xfrm_policy_delete);
702
703 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
704 {
705         struct xfrm_policy *old_pol;
706
707         write_lock_bh(&xfrm_policy_lock);
708         old_pol = sk->sk_policy[dir];
709         sk->sk_policy[dir] = pol;
710         if (pol) {
711                 pol->curlft.add_time = (unsigned long)xtime.tv_sec;
712                 pol->index = xfrm_gen_index(XFRM_POLICY_MAX+dir);
713                 __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
714         }
715         if (old_pol)
716                 __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
717         write_unlock_bh(&xfrm_policy_lock);
718
719         if (old_pol) {
720                 xfrm_policy_kill(old_pol);
721         }
722         return 0;
723 }
724
725 static struct xfrm_policy *clone_policy(struct xfrm_policy *old, int dir)
726 {
727         struct xfrm_policy *newp = xfrm_policy_alloc(GFP_ATOMIC);
728
729         if (newp) {
730                 newp->selector = old->selector;
731                 if (security_xfrm_policy_clone(old, newp)) {
732                         kfree(newp);
733                         return NULL;  /* ENOMEM */
734                 }
735                 newp->lft = old->lft;
736                 newp->curlft = old->curlft;
737                 newp->action = old->action;
738                 newp->flags = old->flags;
739                 newp->xfrm_nr = old->xfrm_nr;
740                 newp->index = old->index;
741                 memcpy(newp->xfrm_vec, old->xfrm_vec,
742                        newp->xfrm_nr*sizeof(struct xfrm_tmpl));
743                 write_lock_bh(&xfrm_policy_lock);
744                 __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir);
745                 write_unlock_bh(&xfrm_policy_lock);
746                 xfrm_pol_put(newp);
747         }
748         return newp;
749 }
750
751 int __xfrm_sk_clone_policy(struct sock *sk)
752 {
753         struct xfrm_policy *p0 = sk->sk_policy[0],
754                            *p1 = sk->sk_policy[1];
755
756         sk->sk_policy[0] = sk->sk_policy[1] = NULL;
757         if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL)
758                 return -ENOMEM;
759         if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL)
760                 return -ENOMEM;
761         return 0;
762 }
763
764 /* Resolve list of templates for the flow, given policy. */
765
766 static int
767 xfrm_tmpl_resolve(struct xfrm_policy *policy, struct flowi *fl,
768                   struct xfrm_state **xfrm,
769                   unsigned short family)
770 {
771         int nx;
772         int i, error;
773         xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
774         xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
775
776         for (nx=0, i = 0; i < policy->xfrm_nr; i++) {
777                 struct xfrm_state *x;
778                 xfrm_address_t *remote = daddr;
779                 xfrm_address_t *local  = saddr;
780                 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
781
782                 if (tmpl->mode == XFRM_MODE_TUNNEL) {
783                         remote = &tmpl->id.daddr;
784                         local = &tmpl->saddr;
785                 }
786
787                 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
788
789                 if (x && x->km.state == XFRM_STATE_VALID) {
790                         xfrm[nx++] = x;
791                         daddr = remote;
792                         saddr = local;
793                         continue;
794                 }
795                 if (x) {
796                         error = (x->km.state == XFRM_STATE_ERROR ?
797                                  -EINVAL : -EAGAIN);
798                         xfrm_state_put(x);
799                 }
800
801                 if (!tmpl->optional)
802                         goto fail;
803         }
804         return nx;
805
806 fail:
807         for (nx--; nx>=0; nx--)
808                 xfrm_state_put(xfrm[nx]);
809         return error;
810 }
811
812 /* Check that the bundle accepts the flow and its components are
813  * still valid.
814  */
815
816 static struct dst_entry *
817 xfrm_find_bundle(struct flowi *fl, struct xfrm_policy *policy, unsigned short family)
818 {
819         struct dst_entry *x;
820         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
821         if (unlikely(afinfo == NULL))
822                 return ERR_PTR(-EINVAL);
823         x = afinfo->find_bundle(fl, policy);
824         xfrm_policy_put_afinfo(afinfo);
825         return x;
826 }
827
828 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
829  * all the metrics... Shortly, bundle a bundle.
830  */
831
832 static int
833 xfrm_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
834                    struct flowi *fl, struct dst_entry **dst_p,
835                    unsigned short family)
836 {
837         int err;
838         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
839         if (unlikely(afinfo == NULL))
840                 return -EINVAL;
841         err = afinfo->bundle_create(policy, xfrm, nx, fl, dst_p);
842         xfrm_policy_put_afinfo(afinfo);
843         return err;
844 }
845
846
847 static int stale_bundle(struct dst_entry *dst);
848
849 /* Main function: finds/creates a bundle for given flow.
850  *
851  * At the moment we eat a raw IP route. Mostly to speed up lookups
852  * on interfaces with disabled IPsec.
853  */
854 int xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
855                 struct sock *sk, int flags)
856 {
857         struct xfrm_policy *policy;
858         struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
859         struct dst_entry *dst, *dst_orig = *dst_p;
860         int nx = 0;
861         int err;
862         u32 genid;
863         u16 family;
864         u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
865
866 restart:
867         genid = atomic_read(&flow_cache_genid);
868         policy = NULL;
869         if (sk && sk->sk_policy[1])
870                 policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
871
872         if (!policy) {
873                 /* To accelerate a bit...  */
874                 if ((dst_orig->flags & DST_NOXFRM) || !xfrm_policy_list[XFRM_POLICY_OUT])
875                         return 0;
876
877                 policy = flow_cache_lookup(fl, dst_orig->ops->family,
878                                            dir, xfrm_policy_lookup);
879         }
880
881         if (!policy)
882                 return 0;
883
884         family = dst_orig->ops->family;
885         policy->curlft.use_time = (unsigned long)xtime.tv_sec;
886
887         switch (policy->action) {
888         case XFRM_POLICY_BLOCK:
889                 /* Prohibit the flow */
890                 err = -EPERM;
891                 goto error;
892
893         case XFRM_POLICY_ALLOW:
894                 if (policy->xfrm_nr == 0) {
895                         /* Flow passes not transformed. */
896                         xfrm_pol_put(policy);
897                         return 0;
898                 }
899
900                 /* Try to find matching bundle.
901                  *
902                  * LATER: help from flow cache. It is optional, this
903                  * is required only for output policy.
904                  */
905                 dst = xfrm_find_bundle(fl, policy, family);
906                 if (IS_ERR(dst)) {
907                         err = PTR_ERR(dst);
908                         goto error;
909                 }
910
911                 if (dst)
912                         break;
913
914                 nx = xfrm_tmpl_resolve(policy, fl, xfrm, family);
915
916                 if (unlikely(nx<0)) {
917                         err = nx;
918                         if (err == -EAGAIN && flags) {
919                                 DECLARE_WAITQUEUE(wait, current);
920
921                                 add_wait_queue(&km_waitq, &wait);
922                                 set_current_state(TASK_INTERRUPTIBLE);
923                                 schedule();
924                                 set_current_state(TASK_RUNNING);
925                                 remove_wait_queue(&km_waitq, &wait);
926
927                                 nx = xfrm_tmpl_resolve(policy, fl, xfrm, family);
928
929                                 if (nx == -EAGAIN && signal_pending(current)) {
930                                         err = -ERESTART;
931                                         goto error;
932                                 }
933                                 if (nx == -EAGAIN ||
934                                     genid != atomic_read(&flow_cache_genid)) {
935                                         xfrm_pol_put(policy);
936                                         goto restart;
937                                 }
938                                 err = nx;
939                         }
940                         if (err < 0)
941                                 goto error;
942                 }
943                 if (nx == 0) {
944                         /* Flow passes not transformed. */
945                         xfrm_pol_put(policy);
946                         return 0;
947                 }
948
949                 dst = dst_orig;
950                 err = xfrm_bundle_create(policy, xfrm, nx, fl, &dst, family);
951
952                 if (unlikely(err)) {
953                         int i;
954                         for (i=0; i<nx; i++)
955                                 xfrm_state_put(xfrm[i]);
956                         goto error;
957                 }
958
959                 write_lock_bh(&policy->lock);
960                 if (unlikely(policy->dead || stale_bundle(dst))) {
961                         /* Wow! While we worked on resolving, this
962                          * policy has gone. Retry. It is not paranoia,
963                          * we just cannot enlist new bundle to dead object.
964                          * We can't enlist stable bundles either.
965                          */
966                         write_unlock_bh(&policy->lock);
967                         if (dst)
968                                 dst_free(dst);
969
970                         err = -EHOSTUNREACH;
971                         goto error;
972                 }
973                 dst->next = policy->bundles;
974                 policy->bundles = dst;
975                 dst_hold(dst);
976                 write_unlock_bh(&policy->lock);
977         }
978         *dst_p = dst;
979         dst_release(dst_orig);
980         xfrm_pol_put(policy);
981         return 0;
982
983 error:
984         dst_release(dst_orig);
985         xfrm_pol_put(policy);
986         *dst_p = NULL;
987         return err;
988 }
989 EXPORT_SYMBOL(xfrm_lookup);
990
991 /* When skb is transformed back to its "native" form, we have to
992  * check policy restrictions. At the moment we make this in maximally
993  * stupid way. Shame on me. :-) Of course, connected sockets must
994  * have policy cached at them.
995  */
996
997 static inline int
998 xfrm_state_ok(struct xfrm_tmpl *tmpl, struct xfrm_state *x, 
999               unsigned short family)
1000 {
1001         if (xfrm_state_kern(x))
1002                 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, family);
1003         return  x->id.proto == tmpl->id.proto &&
1004                 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
1005                 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
1006                 x->props.mode == tmpl->mode &&
1007                 (tmpl->aalgos & (1<<x->props.aalgo)) &&
1008                 !(x->props.mode != XFRM_MODE_TRANSPORT &&
1009                   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 == XFRM_MODE_TRANSPORT)
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 != XFRM_MODE_TRANSPORT)
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         int err;
1037
1038         if (unlikely(afinfo == NULL))
1039                 return -EAFNOSUPPORT;
1040
1041         afinfo->decode_session(skb, fl);
1042         err = security_xfrm_decode_session(skb, &fl->secid);
1043         xfrm_policy_put_afinfo(afinfo);
1044         return err;
1045 }
1046 EXPORT_SYMBOL(xfrm_decode_session);
1047
1048 static inline int secpath_has_tunnel(struct sec_path *sp, int k)
1049 {
1050         for (; k < sp->len; k++) {
1051                 if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT)
1052                         return 1;
1053         }
1054
1055         return 0;
1056 }
1057
1058 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, 
1059                         unsigned short family)
1060 {
1061         struct xfrm_policy *pol;
1062         struct flowi fl;
1063         u8 fl_dir = policy_to_flow_dir(dir);
1064
1065         if (xfrm_decode_session(skb, &fl, family) < 0)
1066                 return 0;
1067         nf_nat_decode_session(skb, &fl, family);
1068
1069         /* First, check used SA against their selectors. */
1070         if (skb->sp) {
1071                 int i;
1072
1073                 for (i=skb->sp->len-1; i>=0; i--) {
1074                         struct xfrm_state *x = skb->sp->xvec[i];
1075                         if (!xfrm_selector_match(&x->sel, &fl, family))
1076                                 return 0;
1077                 }
1078         }
1079
1080         pol = NULL;
1081         if (sk && sk->sk_policy[dir])
1082                 pol = xfrm_sk_policy_lookup(sk, dir, &fl);
1083
1084         if (!pol)
1085                 pol = flow_cache_lookup(&fl, family, fl_dir,
1086                                         xfrm_policy_lookup);
1087
1088         if (!pol)
1089                 return !skb->sp || !secpath_has_tunnel(skb->sp, 0);
1090
1091         pol->curlft.use_time = (unsigned long)xtime.tv_sec;
1092
1093         if (pol->action == XFRM_POLICY_ALLOW) {
1094                 struct sec_path *sp;
1095                 static struct sec_path dummy;
1096                 int i, k;
1097
1098                 if ((sp = skb->sp) == NULL)
1099                         sp = &dummy;
1100
1101                 /* For each tunnel xfrm, find the first matching tmpl.
1102                  * For each tmpl before that, find corresponding xfrm.
1103                  * Order is _important_. Later we will implement
1104                  * some barriers, but at the moment barriers
1105                  * are implied between each two transformations.
1106                  */
1107                 for (i = pol->xfrm_nr-1, k = 0; i >= 0; i--) {
1108                         k = xfrm_policy_ok(pol->xfrm_vec+i, sp, k, family);
1109                         if (k < 0)
1110                                 goto reject;
1111                 }
1112
1113                 if (secpath_has_tunnel(sp, k))
1114                         goto reject;
1115
1116                 xfrm_pol_put(pol);
1117                 return 1;
1118         }
1119
1120 reject:
1121         xfrm_pol_put(pol);
1122         return 0;
1123 }
1124 EXPORT_SYMBOL(__xfrm_policy_check);
1125
1126 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
1127 {
1128         struct flowi fl;
1129
1130         if (xfrm_decode_session(skb, &fl, family) < 0)
1131                 return 0;
1132
1133         return xfrm_lookup(&skb->dst, &fl, NULL, 0) == 0;
1134 }
1135 EXPORT_SYMBOL(__xfrm_route_forward);
1136
1137 /* Optimize later using cookies and generation ids. */
1138
1139 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
1140 {
1141         /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
1142          * to "-1" to force all XFRM destinations to get validated by
1143          * dst_ops->check on every use.  We do this because when a
1144          * normal route referenced by an XFRM dst is obsoleted we do
1145          * not go looking around for all parent referencing XFRM dsts
1146          * so that we can invalidate them.  It is just too much work.
1147          * Instead we make the checks here on every use.  For example:
1148          *
1149          *      XFRM dst A --> IPv4 dst X
1150          *
1151          * X is the "xdst->route" of A (X is also the "dst->path" of A
1152          * in this example).  If X is marked obsolete, "A" will not
1153          * notice.  That's what we are validating here via the
1154          * stale_bundle() check.
1155          *
1156          * When a policy's bundle is pruned, we dst_free() the XFRM
1157          * dst which causes it's ->obsolete field to be set to a
1158          * positive non-zero integer.  If an XFRM dst has been pruned
1159          * like this, we want to force a new route lookup.
1160          */
1161         if (dst->obsolete < 0 && !stale_bundle(dst))
1162                 return dst;
1163
1164         return NULL;
1165 }
1166
1167 static int stale_bundle(struct dst_entry *dst)
1168 {
1169         return !xfrm_bundle_ok((struct xfrm_dst *)dst, NULL, AF_UNSPEC);
1170 }
1171
1172 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
1173 {
1174         while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
1175                 dst->dev = &loopback_dev;
1176                 dev_hold(&loopback_dev);
1177                 dev_put(dev);
1178         }
1179 }
1180 EXPORT_SYMBOL(xfrm_dst_ifdown);
1181
1182 static void xfrm_link_failure(struct sk_buff *skb)
1183 {
1184         /* Impossible. Such dst must be popped before reaches point of failure. */
1185         return;
1186 }
1187
1188 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
1189 {
1190         if (dst) {
1191                 if (dst->obsolete) {
1192                         dst_release(dst);
1193                         dst = NULL;
1194                 }
1195         }
1196         return dst;
1197 }
1198
1199 static void xfrm_prune_bundles(int (*func)(struct dst_entry *))
1200 {
1201         int i;
1202         struct xfrm_policy *pol;
1203         struct dst_entry *dst, **dstp, *gc_list = NULL;
1204
1205         read_lock_bh(&xfrm_policy_lock);
1206         for (i=0; i<2*XFRM_POLICY_MAX; i++) {
1207                 for (pol = xfrm_policy_list[i]; pol; pol = pol->next) {
1208                         write_lock(&pol->lock);
1209                         dstp = &pol->bundles;
1210                         while ((dst=*dstp) != NULL) {
1211                                 if (func(dst)) {
1212                                         *dstp = dst->next;
1213                                         dst->next = gc_list;
1214                                         gc_list = dst;
1215                                 } else {
1216                                         dstp = &dst->next;
1217                                 }
1218                         }
1219                         write_unlock(&pol->lock);
1220                 }
1221         }
1222         read_unlock_bh(&xfrm_policy_lock);
1223
1224         while (gc_list) {
1225                 dst = gc_list;
1226                 gc_list = dst->next;
1227                 dst_free(dst);
1228         }
1229 }
1230
1231 static int unused_bundle(struct dst_entry *dst)
1232 {
1233         return !atomic_read(&dst->__refcnt);
1234 }
1235
1236 static void __xfrm_garbage_collect(void)
1237 {
1238         xfrm_prune_bundles(unused_bundle);
1239 }
1240
1241 int xfrm_flush_bundles(void)
1242 {
1243         xfrm_prune_bundles(stale_bundle);
1244         return 0;
1245 }
1246
1247 static int always_true(struct dst_entry *dst)
1248 {
1249         return 1;
1250 }
1251
1252 void xfrm_flush_all_bundles(void)
1253 {
1254         xfrm_prune_bundles(always_true);
1255 }
1256
1257 void xfrm_init_pmtu(struct dst_entry *dst)
1258 {
1259         do {
1260                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1261                 u32 pmtu, route_mtu_cached;
1262
1263                 pmtu = dst_mtu(dst->child);
1264                 xdst->child_mtu_cached = pmtu;
1265
1266                 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
1267
1268                 route_mtu_cached = dst_mtu(xdst->route);
1269                 xdst->route_mtu_cached = route_mtu_cached;
1270
1271                 if (pmtu > route_mtu_cached)
1272                         pmtu = route_mtu_cached;
1273
1274                 dst->metrics[RTAX_MTU-1] = pmtu;
1275         } while ((dst = dst->next));
1276 }
1277
1278 EXPORT_SYMBOL(xfrm_init_pmtu);
1279
1280 /* Check that the bundle accepts the flow and its components are
1281  * still valid.
1282  */
1283
1284 int xfrm_bundle_ok(struct xfrm_dst *first, struct flowi *fl, int family)
1285 {
1286         struct dst_entry *dst = &first->u.dst;
1287         struct xfrm_dst *last;
1288         u32 mtu;
1289
1290         if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) ||
1291             (dst->dev && !netif_running(dst->dev)))
1292                 return 0;
1293
1294         last = NULL;
1295
1296         do {
1297                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1298
1299                 if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family))
1300                         return 0;
1301                 if (fl && !security_xfrm_flow_state_match(fl, dst->xfrm))
1302                         return 0;
1303                 if (dst->xfrm->km.state != XFRM_STATE_VALID)
1304                         return 0;
1305
1306                 mtu = dst_mtu(dst->child);
1307                 if (xdst->child_mtu_cached != mtu) {
1308                         last = xdst;
1309                         xdst->child_mtu_cached = mtu;
1310                 }
1311
1312                 if (!dst_check(xdst->route, xdst->route_cookie))
1313                         return 0;
1314                 mtu = dst_mtu(xdst->route);
1315                 if (xdst->route_mtu_cached != mtu) {
1316                         last = xdst;
1317                         xdst->route_mtu_cached = mtu;
1318                 }
1319
1320                 dst = dst->child;
1321         } while (dst->xfrm);
1322
1323         if (likely(!last))
1324                 return 1;
1325
1326         mtu = last->child_mtu_cached;
1327         for (;;) {
1328                 dst = &last->u.dst;
1329
1330                 mtu = xfrm_state_mtu(dst->xfrm, mtu);
1331                 if (mtu > last->route_mtu_cached)
1332                         mtu = last->route_mtu_cached;
1333                 dst->metrics[RTAX_MTU-1] = mtu;
1334
1335                 if (last == first)
1336                         break;
1337
1338                 last = last->u.next;
1339                 last->child_mtu_cached = mtu;
1340         }
1341
1342         return 1;
1343 }
1344
1345 EXPORT_SYMBOL(xfrm_bundle_ok);
1346
1347 int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
1348 {
1349         int err = 0;
1350         if (unlikely(afinfo == NULL))
1351                 return -EINVAL;
1352         if (unlikely(afinfo->family >= NPROTO))
1353                 return -EAFNOSUPPORT;
1354         write_lock_bh(&xfrm_policy_afinfo_lock);
1355         if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
1356                 err = -ENOBUFS;
1357         else {
1358                 struct dst_ops *dst_ops = afinfo->dst_ops;
1359                 if (likely(dst_ops->kmem_cachep == NULL))
1360                         dst_ops->kmem_cachep = xfrm_dst_cache;
1361                 if (likely(dst_ops->check == NULL))
1362                         dst_ops->check = xfrm_dst_check;
1363                 if (likely(dst_ops->negative_advice == NULL))
1364                         dst_ops->negative_advice = xfrm_negative_advice;
1365                 if (likely(dst_ops->link_failure == NULL))
1366                         dst_ops->link_failure = xfrm_link_failure;
1367                 if (likely(afinfo->garbage_collect == NULL))
1368                         afinfo->garbage_collect = __xfrm_garbage_collect;
1369                 xfrm_policy_afinfo[afinfo->family] = afinfo;
1370         }
1371         write_unlock_bh(&xfrm_policy_afinfo_lock);
1372         return err;
1373 }
1374 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
1375
1376 int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
1377 {
1378         int err = 0;
1379         if (unlikely(afinfo == NULL))
1380                 return -EINVAL;
1381         if (unlikely(afinfo->family >= NPROTO))
1382                 return -EAFNOSUPPORT;
1383         write_lock_bh(&xfrm_policy_afinfo_lock);
1384         if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
1385                 if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
1386                         err = -EINVAL;
1387                 else {
1388                         struct dst_ops *dst_ops = afinfo->dst_ops;
1389                         xfrm_policy_afinfo[afinfo->family] = NULL;
1390                         dst_ops->kmem_cachep = NULL;
1391                         dst_ops->check = NULL;
1392                         dst_ops->negative_advice = NULL;
1393                         dst_ops->link_failure = NULL;
1394                         afinfo->garbage_collect = NULL;
1395                 }
1396         }
1397         write_unlock_bh(&xfrm_policy_afinfo_lock);
1398         return err;
1399 }
1400 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
1401
1402 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
1403 {
1404         struct xfrm_policy_afinfo *afinfo;
1405         if (unlikely(family >= NPROTO))
1406                 return NULL;
1407         read_lock(&xfrm_policy_afinfo_lock);
1408         afinfo = xfrm_policy_afinfo[family];
1409         if (unlikely(!afinfo))
1410                 read_unlock(&xfrm_policy_afinfo_lock);
1411         return afinfo;
1412 }
1413
1414 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
1415 {
1416         read_unlock(&xfrm_policy_afinfo_lock);
1417 }
1418
1419 static struct xfrm_policy_afinfo *xfrm_policy_lock_afinfo(unsigned int family)
1420 {
1421         struct xfrm_policy_afinfo *afinfo;
1422         if (unlikely(family >= NPROTO))
1423                 return NULL;
1424         write_lock_bh(&xfrm_policy_afinfo_lock);
1425         afinfo = xfrm_policy_afinfo[family];
1426         if (unlikely(!afinfo))
1427                 write_unlock_bh(&xfrm_policy_afinfo_lock);
1428         return afinfo;
1429 }
1430
1431 static void xfrm_policy_unlock_afinfo(struct xfrm_policy_afinfo *afinfo)
1432 {
1433         write_unlock_bh(&xfrm_policy_afinfo_lock);
1434 }
1435
1436 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
1437 {
1438         switch (event) {
1439         case NETDEV_DOWN:
1440                 xfrm_flush_bundles();
1441         }
1442         return NOTIFY_DONE;
1443 }
1444
1445 static struct notifier_block xfrm_dev_notifier = {
1446         xfrm_dev_event,
1447         NULL,
1448         0
1449 };
1450
1451 static void __init xfrm_policy_init(void)
1452 {
1453         xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
1454                                            sizeof(struct xfrm_dst),
1455                                            0, SLAB_HWCACHE_ALIGN,
1456                                            NULL, NULL);
1457         if (!xfrm_dst_cache)
1458                 panic("XFRM: failed to allocate xfrm_dst_cache\n");
1459
1460         INIT_WORK(&xfrm_policy_gc_work, xfrm_policy_gc_task, NULL);
1461         register_netdevice_notifier(&xfrm_dev_notifier);
1462 }
1463
1464 void __init xfrm_init(void)
1465 {
1466         xfrm_state_init();
1467         xfrm_policy_init();
1468         xfrm_input_init();
1469 }
1470