26b846e11bfb3241f268f86c7daa45c872a65164
[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 <linux/cache.h>
26 #include <net/xfrm.h>
27 #include <net/ip.h>
28
29 #include "xfrm_hash.h"
30
31 int sysctl_xfrm_larval_drop __read_mostly;
32
33 DEFINE_MUTEX(xfrm_cfg_mutex);
34 EXPORT_SYMBOL(xfrm_cfg_mutex);
35
36 static DEFINE_RWLOCK(xfrm_policy_lock);
37
38 unsigned int xfrm_policy_count[XFRM_POLICY_MAX*2];
39 EXPORT_SYMBOL(xfrm_policy_count);
40
41 static DEFINE_RWLOCK(xfrm_policy_afinfo_lock);
42 static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO];
43
44 static struct kmem_cache *xfrm_dst_cache __read_mostly;
45
46 static struct work_struct xfrm_policy_gc_work;
47 static HLIST_HEAD(xfrm_policy_gc_list);
48 static DEFINE_SPINLOCK(xfrm_policy_gc_lock);
49
50 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family);
51 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);
52
53 static inline int
54 __xfrm4_selector_match(struct xfrm_selector *sel, struct flowi *fl)
55 {
56         return  addr_match(&fl->fl4_dst, &sel->daddr, sel->prefixlen_d) &&
57                 addr_match(&fl->fl4_src, &sel->saddr, sel->prefixlen_s) &&
58                 !((xfrm_flowi_dport(fl) ^ sel->dport) & sel->dport_mask) &&
59                 !((xfrm_flowi_sport(fl) ^ sel->sport) & sel->sport_mask) &&
60                 (fl->proto == sel->proto || !sel->proto) &&
61                 (fl->oif == sel->ifindex || !sel->ifindex);
62 }
63
64 static inline int
65 __xfrm6_selector_match(struct xfrm_selector *sel, struct flowi *fl)
66 {
67         return  addr_match(&fl->fl6_dst, &sel->daddr, sel->prefixlen_d) &&
68                 addr_match(&fl->fl6_src, &sel->saddr, sel->prefixlen_s) &&
69                 !((xfrm_flowi_dport(fl) ^ sel->dport) & sel->dport_mask) &&
70                 !((xfrm_flowi_sport(fl) ^ sel->sport) & sel->sport_mask) &&
71                 (fl->proto == sel->proto || !sel->proto) &&
72                 (fl->oif == sel->ifindex || !sel->ifindex);
73 }
74
75 int xfrm_selector_match(struct xfrm_selector *sel, struct flowi *fl,
76                     unsigned short family)
77 {
78         switch (family) {
79         case AF_INET:
80                 return __xfrm4_selector_match(sel, fl);
81         case AF_INET6:
82                 return __xfrm6_selector_match(sel, fl);
83         }
84         return 0;
85 }
86
87 int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl,
88                     unsigned short family)
89 {
90         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
91         int err = 0;
92
93         if (unlikely(afinfo == NULL))
94                 return -EAFNOSUPPORT;
95
96         if (likely(afinfo->dst_lookup != NULL))
97                 err = afinfo->dst_lookup(dst, fl);
98         else
99                 err = -EINVAL;
100         xfrm_policy_put_afinfo(afinfo);
101         return err;
102 }
103 EXPORT_SYMBOL(xfrm_dst_lookup);
104
105 static inline unsigned long make_jiffies(long secs)
106 {
107         if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
108                 return MAX_SCHEDULE_TIMEOUT-1;
109         else
110                 return secs*HZ;
111 }
112
113 static void xfrm_policy_timer(unsigned long data)
114 {
115         struct xfrm_policy *xp = (struct xfrm_policy*)data;
116         unsigned long now = get_seconds();
117         long next = LONG_MAX;
118         int warn = 0;
119         int dir;
120
121         read_lock(&xp->lock);
122
123         if (xp->dead)
124                 goto out;
125
126         dir = xfrm_policy_id2dir(xp->index);
127
128         if (xp->lft.hard_add_expires_seconds) {
129                 long tmo = xp->lft.hard_add_expires_seconds +
130                         xp->curlft.add_time - now;
131                 if (tmo <= 0)
132                         goto expired;
133                 if (tmo < next)
134                         next = tmo;
135         }
136         if (xp->lft.hard_use_expires_seconds) {
137                 long tmo = xp->lft.hard_use_expires_seconds +
138                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
139                 if (tmo <= 0)
140                         goto expired;
141                 if (tmo < next)
142                         next = tmo;
143         }
144         if (xp->lft.soft_add_expires_seconds) {
145                 long tmo = xp->lft.soft_add_expires_seconds +
146                         xp->curlft.add_time - now;
147                 if (tmo <= 0) {
148                         warn = 1;
149                         tmo = XFRM_KM_TIMEOUT;
150                 }
151                 if (tmo < next)
152                         next = tmo;
153         }
154         if (xp->lft.soft_use_expires_seconds) {
155                 long tmo = xp->lft.soft_use_expires_seconds +
156                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
157                 if (tmo <= 0) {
158                         warn = 1;
159                         tmo = XFRM_KM_TIMEOUT;
160                 }
161                 if (tmo < next)
162                         next = tmo;
163         }
164
165         if (warn)
166                 km_policy_expired(xp, dir, 0, 0);
167         if (next != LONG_MAX &&
168             !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
169                 xfrm_pol_hold(xp);
170
171 out:
172         read_unlock(&xp->lock);
173         xfrm_pol_put(xp);
174         return;
175
176 expired:
177         read_unlock(&xp->lock);
178         if (!xfrm_policy_delete(xp, dir))
179                 km_policy_expired(xp, dir, 1, 0);
180         xfrm_pol_put(xp);
181 }
182
183
184 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
185  * SPD calls.
186  */
187
188 struct xfrm_policy *xfrm_policy_alloc(gfp_t gfp)
189 {
190         struct xfrm_policy *policy;
191
192         policy = kzalloc(sizeof(struct xfrm_policy), gfp);
193
194         if (policy) {
195                 INIT_HLIST_NODE(&policy->bydst);
196                 INIT_HLIST_NODE(&policy->byidx);
197                 rwlock_init(&policy->lock);
198                 atomic_set(&policy->refcnt, 1);
199                 init_timer(&policy->timer);
200                 policy->timer.data = (unsigned long)policy;
201                 policy->timer.function = xfrm_policy_timer;
202         }
203         return policy;
204 }
205 EXPORT_SYMBOL(xfrm_policy_alloc);
206
207 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
208
209 void __xfrm_policy_destroy(struct xfrm_policy *policy)
210 {
211         BUG_ON(!policy->dead);
212
213         BUG_ON(policy->bundles);
214
215         if (del_timer(&policy->timer))
216                 BUG();
217
218         security_xfrm_policy_free(policy);
219         kfree(policy);
220 }
221 EXPORT_SYMBOL(__xfrm_policy_destroy);
222
223 static void xfrm_policy_gc_kill(struct xfrm_policy *policy)
224 {
225         struct dst_entry *dst;
226
227         while ((dst = policy->bundles) != NULL) {
228                 policy->bundles = dst->next;
229                 dst_free(dst);
230         }
231
232         if (del_timer(&policy->timer))
233                 atomic_dec(&policy->refcnt);
234
235         if (atomic_read(&policy->refcnt) > 1)
236                 flow_cache_flush();
237
238         xfrm_pol_put(policy);
239 }
240
241 static void xfrm_policy_gc_task(struct work_struct *work)
242 {
243         struct xfrm_policy *policy;
244         struct hlist_node *entry, *tmp;
245         struct hlist_head gc_list;
246
247         spin_lock_bh(&xfrm_policy_gc_lock);
248         gc_list.first = xfrm_policy_gc_list.first;
249         INIT_HLIST_HEAD(&xfrm_policy_gc_list);
250         spin_unlock_bh(&xfrm_policy_gc_lock);
251
252         hlist_for_each_entry_safe(policy, entry, tmp, &gc_list, bydst)
253                 xfrm_policy_gc_kill(policy);
254 }
255
256 /* Rule must be locked. Release descentant resources, announce
257  * entry dead. The rule must be unlinked from lists to the moment.
258  */
259
260 static void xfrm_policy_kill(struct xfrm_policy *policy)
261 {
262         int dead;
263
264         write_lock_bh(&policy->lock);
265         dead = policy->dead;
266         policy->dead = 1;
267         write_unlock_bh(&policy->lock);
268
269         if (unlikely(dead)) {
270                 WARN_ON(1);
271                 return;
272         }
273
274         spin_lock(&xfrm_policy_gc_lock);
275         hlist_add_head(&policy->bydst, &xfrm_policy_gc_list);
276         spin_unlock(&xfrm_policy_gc_lock);
277
278         schedule_work(&xfrm_policy_gc_work);
279 }
280
281 struct xfrm_policy_hash {
282         struct hlist_head       *table;
283         unsigned int            hmask;
284 };
285
286 static struct hlist_head xfrm_policy_inexact[XFRM_POLICY_MAX*2];
287 static struct xfrm_policy_hash xfrm_policy_bydst[XFRM_POLICY_MAX*2] __read_mostly;
288 static struct hlist_head *xfrm_policy_byidx __read_mostly;
289 static unsigned int xfrm_idx_hmask __read_mostly;
290 static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
291
292 static inline unsigned int idx_hash(u32 index)
293 {
294         return __idx_hash(index, xfrm_idx_hmask);
295 }
296
297 static struct hlist_head *policy_hash_bysel(struct xfrm_selector *sel, unsigned short family, int dir)
298 {
299         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
300         unsigned int hash = __sel_hash(sel, family, hmask);
301
302         return (hash == hmask + 1 ?
303                 &xfrm_policy_inexact[dir] :
304                 xfrm_policy_bydst[dir].table + hash);
305 }
306
307 static struct hlist_head *policy_hash_direct(xfrm_address_t *daddr, xfrm_address_t *saddr, unsigned short family, int dir)
308 {
309         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
310         unsigned int hash = __addr_hash(daddr, saddr, family, hmask);
311
312         return xfrm_policy_bydst[dir].table + hash;
313 }
314
315 static void xfrm_dst_hash_transfer(struct hlist_head *list,
316                                    struct hlist_head *ndsttable,
317                                    unsigned int nhashmask)
318 {
319         struct hlist_node *entry, *tmp;
320         struct xfrm_policy *pol;
321
322         hlist_for_each_entry_safe(pol, entry, tmp, list, bydst) {
323                 unsigned int h;
324
325                 h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
326                                 pol->family, nhashmask);
327                 hlist_add_head(&pol->bydst, ndsttable+h);
328         }
329 }
330
331 static void xfrm_idx_hash_transfer(struct hlist_head *list,
332                                    struct hlist_head *nidxtable,
333                                    unsigned int nhashmask)
334 {
335         struct hlist_node *entry, *tmp;
336         struct xfrm_policy *pol;
337
338         hlist_for_each_entry_safe(pol, entry, tmp, list, byidx) {
339                 unsigned int h;
340
341                 h = __idx_hash(pol->index, nhashmask);
342                 hlist_add_head(&pol->byidx, nidxtable+h);
343         }
344 }
345
346 static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
347 {
348         return ((old_hmask + 1) << 1) - 1;
349 }
350
351 static void xfrm_bydst_resize(int dir)
352 {
353         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
354         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
355         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
356         struct hlist_head *odst = xfrm_policy_bydst[dir].table;
357         struct hlist_head *ndst = xfrm_hash_alloc(nsize);
358         int i;
359
360         if (!ndst)
361                 return;
362
363         write_lock_bh(&xfrm_policy_lock);
364
365         for (i = hmask; i >= 0; i--)
366                 xfrm_dst_hash_transfer(odst + i, ndst, nhashmask);
367
368         xfrm_policy_bydst[dir].table = ndst;
369         xfrm_policy_bydst[dir].hmask = nhashmask;
370
371         write_unlock_bh(&xfrm_policy_lock);
372
373         xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
374 }
375
376 static void xfrm_byidx_resize(int total)
377 {
378         unsigned int hmask = xfrm_idx_hmask;
379         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
380         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
381         struct hlist_head *oidx = xfrm_policy_byidx;
382         struct hlist_head *nidx = xfrm_hash_alloc(nsize);
383         int i;
384
385         if (!nidx)
386                 return;
387
388         write_lock_bh(&xfrm_policy_lock);
389
390         for (i = hmask; i >= 0; i--)
391                 xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
392
393         xfrm_policy_byidx = nidx;
394         xfrm_idx_hmask = nhashmask;
395
396         write_unlock_bh(&xfrm_policy_lock);
397
398         xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
399 }
400
401 static inline int xfrm_bydst_should_resize(int dir, int *total)
402 {
403         unsigned int cnt = xfrm_policy_count[dir];
404         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
405
406         if (total)
407                 *total += cnt;
408
409         if ((hmask + 1) < xfrm_policy_hashmax &&
410             cnt > hmask)
411                 return 1;
412
413         return 0;
414 }
415
416 static inline int xfrm_byidx_should_resize(int total)
417 {
418         unsigned int hmask = xfrm_idx_hmask;
419
420         if ((hmask + 1) < xfrm_policy_hashmax &&
421             total > hmask)
422                 return 1;
423
424         return 0;
425 }
426
427 void xfrm_spd_getinfo(struct xfrmk_spdinfo *si)
428 {
429         read_lock_bh(&xfrm_policy_lock);
430         si->incnt = xfrm_policy_count[XFRM_POLICY_IN];
431         si->outcnt = xfrm_policy_count[XFRM_POLICY_OUT];
432         si->fwdcnt = xfrm_policy_count[XFRM_POLICY_FWD];
433         si->inscnt = xfrm_policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
434         si->outscnt = xfrm_policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
435         si->fwdscnt = xfrm_policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
436         si->spdhcnt = xfrm_idx_hmask;
437         si->spdhmcnt = xfrm_policy_hashmax;
438         read_unlock_bh(&xfrm_policy_lock);
439 }
440 EXPORT_SYMBOL(xfrm_spd_getinfo);
441
442 static DEFINE_MUTEX(hash_resize_mutex);
443 static void xfrm_hash_resize(struct work_struct *__unused)
444 {
445         int dir, total;
446
447         mutex_lock(&hash_resize_mutex);
448
449         total = 0;
450         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
451                 if (xfrm_bydst_should_resize(dir, &total))
452                         xfrm_bydst_resize(dir);
453         }
454         if (xfrm_byidx_should_resize(total))
455                 xfrm_byidx_resize(total);
456
457         mutex_unlock(&hash_resize_mutex);
458 }
459
460 static DECLARE_WORK(xfrm_hash_work, xfrm_hash_resize);
461
462 /* Generate new index... KAME seems to generate them ordered by cost
463  * of an absolute inpredictability of ordering of rules. This will not pass. */
464 static u32 xfrm_gen_index(u8 type, int dir)
465 {
466         static u32 idx_generator;
467
468         for (;;) {
469                 struct hlist_node *entry;
470                 struct hlist_head *list;
471                 struct xfrm_policy *p;
472                 u32 idx;
473                 int found;
474
475                 idx = (idx_generator | dir);
476                 idx_generator += 8;
477                 if (idx == 0)
478                         idx = 8;
479                 list = xfrm_policy_byidx + idx_hash(idx);
480                 found = 0;
481                 hlist_for_each_entry(p, entry, list, byidx) {
482                         if (p->index == idx) {
483                                 found = 1;
484                                 break;
485                         }
486                 }
487                 if (!found)
488                         return idx;
489         }
490 }
491
492 static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
493 {
494         u32 *p1 = (u32 *) s1;
495         u32 *p2 = (u32 *) s2;
496         int len = sizeof(struct xfrm_selector) / sizeof(u32);
497         int i;
498
499         for (i = 0; i < len; i++) {
500                 if (p1[i] != p2[i])
501                         return 1;
502         }
503
504         return 0;
505 }
506
507 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
508 {
509         struct xfrm_policy *pol;
510         struct xfrm_policy *delpol;
511         struct hlist_head *chain;
512         struct hlist_node *entry, *newpos;
513         struct dst_entry *gc_list;
514
515         write_lock_bh(&xfrm_policy_lock);
516         chain = policy_hash_bysel(&policy->selector, policy->family, dir);
517         delpol = NULL;
518         newpos = NULL;
519         hlist_for_each_entry(pol, entry, chain, bydst) {
520                 if (pol->type == policy->type &&
521                     !selector_cmp(&pol->selector, &policy->selector) &&
522                     xfrm_sec_ctx_match(pol->security, policy->security) &&
523                     !WARN_ON(delpol)) {
524                         if (excl) {
525                                 write_unlock_bh(&xfrm_policy_lock);
526                                 return -EEXIST;
527                         }
528                         delpol = pol;
529                         if (policy->priority > pol->priority)
530                                 continue;
531                 } else if (policy->priority >= pol->priority) {
532                         newpos = &pol->bydst;
533                         continue;
534                 }
535                 if (delpol)
536                         break;
537         }
538         if (newpos)
539                 hlist_add_after(newpos, &policy->bydst);
540         else
541                 hlist_add_head(&policy->bydst, chain);
542         xfrm_pol_hold(policy);
543         xfrm_policy_count[dir]++;
544         atomic_inc(&flow_cache_genid);
545         if (delpol) {
546                 hlist_del(&delpol->bydst);
547                 hlist_del(&delpol->byidx);
548                 xfrm_policy_count[dir]--;
549         }
550         policy->index = delpol ? delpol->index : xfrm_gen_index(policy->type, dir);
551         hlist_add_head(&policy->byidx, xfrm_policy_byidx+idx_hash(policy->index));
552         policy->curlft.add_time = get_seconds();
553         policy->curlft.use_time = 0;
554         if (!mod_timer(&policy->timer, jiffies + HZ))
555                 xfrm_pol_hold(policy);
556         write_unlock_bh(&xfrm_policy_lock);
557
558         if (delpol)
559                 xfrm_policy_kill(delpol);
560         else if (xfrm_bydst_should_resize(dir, NULL))
561                 schedule_work(&xfrm_hash_work);
562
563         read_lock_bh(&xfrm_policy_lock);
564         gc_list = NULL;
565         entry = &policy->bydst;
566         hlist_for_each_entry_continue(policy, entry, bydst) {
567                 struct dst_entry *dst;
568
569                 write_lock(&policy->lock);
570                 dst = policy->bundles;
571                 if (dst) {
572                         struct dst_entry *tail = dst;
573                         while (tail->next)
574                                 tail = tail->next;
575                         tail->next = gc_list;
576                         gc_list = dst;
577
578                         policy->bundles = NULL;
579                 }
580                 write_unlock(&policy->lock);
581         }
582         read_unlock_bh(&xfrm_policy_lock);
583
584         while (gc_list) {
585                 struct dst_entry *dst = gc_list;
586
587                 gc_list = dst->next;
588                 dst_free(dst);
589         }
590
591         return 0;
592 }
593 EXPORT_SYMBOL(xfrm_policy_insert);
594
595 struct xfrm_policy *xfrm_policy_bysel_ctx(u8 type, int dir,
596                                           struct xfrm_selector *sel,
597                                           struct xfrm_sec_ctx *ctx, int delete,
598                                           int *err)
599 {
600         struct xfrm_policy *pol, *ret;
601         struct hlist_head *chain;
602         struct hlist_node *entry;
603
604         *err = 0;
605         write_lock_bh(&xfrm_policy_lock);
606         chain = policy_hash_bysel(sel, sel->family, dir);
607         ret = NULL;
608         hlist_for_each_entry(pol, entry, chain, bydst) {
609                 if (pol->type == type &&
610                     !selector_cmp(sel, &pol->selector) &&
611                     xfrm_sec_ctx_match(ctx, pol->security)) {
612                         xfrm_pol_hold(pol);
613                         if (delete) {
614                                 *err = security_xfrm_policy_delete(pol);
615                                 if (*err) {
616                                         write_unlock_bh(&xfrm_policy_lock);
617                                         return pol;
618                                 }
619                                 hlist_del(&pol->bydst);
620                                 hlist_del(&pol->byidx);
621                                 xfrm_policy_count[dir]--;
622                         }
623                         ret = pol;
624                         break;
625                 }
626         }
627         write_unlock_bh(&xfrm_policy_lock);
628
629         if (ret && delete) {
630                 atomic_inc(&flow_cache_genid);
631                 xfrm_policy_kill(ret);
632         }
633         return ret;
634 }
635 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
636
637 struct xfrm_policy *xfrm_policy_byid(u8 type, int dir, u32 id, int delete,
638                                      int *err)
639 {
640         struct xfrm_policy *pol, *ret;
641         struct hlist_head *chain;
642         struct hlist_node *entry;
643
644         *err = -ENOENT;
645         if (xfrm_policy_id2dir(id) != dir)
646                 return NULL;
647
648         *err = 0;
649         write_lock_bh(&xfrm_policy_lock);
650         chain = xfrm_policy_byidx + idx_hash(id);
651         ret = NULL;
652         hlist_for_each_entry(pol, entry, chain, byidx) {
653                 if (pol->type == type && pol->index == id) {
654                         xfrm_pol_hold(pol);
655                         if (delete) {
656                                 *err = security_xfrm_policy_delete(pol);
657                                 if (*err) {
658                                         write_unlock_bh(&xfrm_policy_lock);
659                                         return pol;
660                                 }
661                                 hlist_del(&pol->bydst);
662                                 hlist_del(&pol->byidx);
663                                 xfrm_policy_count[dir]--;
664                         }
665                         ret = pol;
666                         break;
667                 }
668         }
669         write_unlock_bh(&xfrm_policy_lock);
670
671         if (ret && delete) {
672                 atomic_inc(&flow_cache_genid);
673                 xfrm_policy_kill(ret);
674         }
675         return ret;
676 }
677 EXPORT_SYMBOL(xfrm_policy_byid);
678
679 #ifdef CONFIG_SECURITY_NETWORK_XFRM
680 static inline int
681 xfrm_policy_flush_secctx_check(u8 type, struct xfrm_audit *audit_info)
682 {
683         int dir, err = 0;
684
685         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
686                 struct xfrm_policy *pol;
687                 struct hlist_node *entry;
688                 int i;
689
690                 hlist_for_each_entry(pol, entry,
691                                      &xfrm_policy_inexact[dir], bydst) {
692                         if (pol->type != type)
693                                 continue;
694                         err = security_xfrm_policy_delete(pol);
695                         if (err) {
696                                 xfrm_audit_policy_delete(pol, 0,
697                                                          audit_info->loginuid,
698                                                          audit_info->secid);
699                                 return err;
700                         }
701                 }
702                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
703                         hlist_for_each_entry(pol, entry,
704                                              xfrm_policy_bydst[dir].table + i,
705                                              bydst) {
706                                 if (pol->type != type)
707                                         continue;
708                                 err = security_xfrm_policy_delete(pol);
709                                 if (err) {
710                                         xfrm_audit_policy_delete(pol, 0,
711                                                         audit_info->loginuid,
712                                                         audit_info->secid);
713                                         return err;
714                                 }
715                         }
716                 }
717         }
718         return err;
719 }
720 #else
721 static inline int
722 xfrm_policy_flush_secctx_check(u8 type, struct xfrm_audit *audit_info)
723 {
724         return 0;
725 }
726 #endif
727
728 int xfrm_policy_flush(u8 type, struct xfrm_audit *audit_info)
729 {
730         int dir, err = 0;
731
732         write_lock_bh(&xfrm_policy_lock);
733
734         err = xfrm_policy_flush_secctx_check(type, audit_info);
735         if (err)
736                 goto out;
737
738         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
739                 struct xfrm_policy *pol;
740                 struct hlist_node *entry;
741                 int i, killed;
742
743                 killed = 0;
744         again1:
745                 hlist_for_each_entry(pol, entry,
746                                      &xfrm_policy_inexact[dir], bydst) {
747                         if (pol->type != type)
748                                 continue;
749                         hlist_del(&pol->bydst);
750                         hlist_del(&pol->byidx);
751                         write_unlock_bh(&xfrm_policy_lock);
752
753                         xfrm_audit_policy_delete(pol, 1, audit_info->loginuid,
754                                                  audit_info->secid);
755
756                         xfrm_policy_kill(pol);
757                         killed++;
758
759                         write_lock_bh(&xfrm_policy_lock);
760                         goto again1;
761                 }
762
763                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
764         again2:
765                         hlist_for_each_entry(pol, entry,
766                                              xfrm_policy_bydst[dir].table + i,
767                                              bydst) {
768                                 if (pol->type != type)
769                                         continue;
770                                 hlist_del(&pol->bydst);
771                                 hlist_del(&pol->byidx);
772                                 write_unlock_bh(&xfrm_policy_lock);
773
774                                 xfrm_audit_policy_delete(pol, 1,
775                                                          audit_info->loginuid,
776                                                          audit_info->secid);
777                                 xfrm_policy_kill(pol);
778                                 killed++;
779
780                                 write_lock_bh(&xfrm_policy_lock);
781                                 goto again2;
782                         }
783                 }
784
785                 xfrm_policy_count[dir] -= killed;
786         }
787         atomic_inc(&flow_cache_genid);
788 out:
789         write_unlock_bh(&xfrm_policy_lock);
790         return err;
791 }
792 EXPORT_SYMBOL(xfrm_policy_flush);
793
794 int xfrm_policy_walk(u8 type, int (*func)(struct xfrm_policy *, int, int, void*),
795                      void *data)
796 {
797         struct xfrm_policy *pol, *last = NULL;
798         struct hlist_node *entry;
799         int dir, last_dir = 0, count, error;
800
801         read_lock_bh(&xfrm_policy_lock);
802         count = 0;
803
804         for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
805                 struct hlist_head *table = xfrm_policy_bydst[dir].table;
806                 int i;
807
808                 hlist_for_each_entry(pol, entry,
809                                      &xfrm_policy_inexact[dir], bydst) {
810                         if (pol->type != type)
811                                 continue;
812                         if (last) {
813                                 error = func(last, last_dir % XFRM_POLICY_MAX,
814                                              count, data);
815                                 if (error)
816                                         goto out;
817                         }
818                         last = pol;
819                         last_dir = dir;
820                         count++;
821                 }
822                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
823                         hlist_for_each_entry(pol, entry, table + i, bydst) {
824                                 if (pol->type != type)
825                                         continue;
826                                 if (last) {
827                                         error = func(last, last_dir % XFRM_POLICY_MAX,
828                                                      count, data);
829                                         if (error)
830                                                 goto out;
831                                 }
832                                 last = pol;
833                                 last_dir = dir;
834                                 count++;
835                         }
836                 }
837         }
838         if (count == 0) {
839                 error = -ENOENT;
840                 goto out;
841         }
842         error = func(last, last_dir % XFRM_POLICY_MAX, 0, data);
843 out:
844         read_unlock_bh(&xfrm_policy_lock);
845         return error;
846 }
847 EXPORT_SYMBOL(xfrm_policy_walk);
848
849 /*
850  * Find policy to apply to this flow.
851  *
852  * Returns 0 if policy found, else an -errno.
853  */
854 static int xfrm_policy_match(struct xfrm_policy *pol, struct flowi *fl,
855                              u8 type, u16 family, int dir)
856 {
857         struct xfrm_selector *sel = &pol->selector;
858         int match, ret = -ESRCH;
859
860         if (pol->family != family ||
861             pol->type != type)
862                 return ret;
863
864         match = xfrm_selector_match(sel, fl, family);
865         if (match)
866                 ret = security_xfrm_policy_lookup(pol, fl->secid, dir);
867
868         return ret;
869 }
870
871 static struct xfrm_policy *xfrm_policy_lookup_bytype(u8 type, struct flowi *fl,
872                                                      u16 family, u8 dir)
873 {
874         int err;
875         struct xfrm_policy *pol, *ret;
876         xfrm_address_t *daddr, *saddr;
877         struct hlist_node *entry;
878         struct hlist_head *chain;
879         u32 priority = ~0U;
880
881         daddr = xfrm_flowi_daddr(fl, family);
882         saddr = xfrm_flowi_saddr(fl, family);
883         if (unlikely(!daddr || !saddr))
884                 return NULL;
885
886         read_lock_bh(&xfrm_policy_lock);
887         chain = policy_hash_direct(daddr, saddr, family, dir);
888         ret = NULL;
889         hlist_for_each_entry(pol, entry, chain, bydst) {
890                 err = xfrm_policy_match(pol, fl, type, family, dir);
891                 if (err) {
892                         if (err == -ESRCH)
893                                 continue;
894                         else {
895                                 ret = ERR_PTR(err);
896                                 goto fail;
897                         }
898                 } else {
899                         ret = pol;
900                         priority = ret->priority;
901                         break;
902                 }
903         }
904         chain = &xfrm_policy_inexact[dir];
905         hlist_for_each_entry(pol, entry, chain, bydst) {
906                 err = xfrm_policy_match(pol, fl, type, family, dir);
907                 if (err) {
908                         if (err == -ESRCH)
909                                 continue;
910                         else {
911                                 ret = ERR_PTR(err);
912                                 goto fail;
913                         }
914                 } else if (pol->priority < priority) {
915                         ret = pol;
916                         break;
917                 }
918         }
919         if (ret)
920                 xfrm_pol_hold(ret);
921 fail:
922         read_unlock_bh(&xfrm_policy_lock);
923
924         return ret;
925 }
926
927 static int xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
928                                void **objp, atomic_t **obj_refp)
929 {
930         struct xfrm_policy *pol;
931         int err = 0;
932
933 #ifdef CONFIG_XFRM_SUB_POLICY
934         pol = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_SUB, fl, family, dir);
935         if (IS_ERR(pol)) {
936                 err = PTR_ERR(pol);
937                 pol = NULL;
938         }
939         if (pol || err)
940                 goto end;
941 #endif
942         pol = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN, fl, family, dir);
943         if (IS_ERR(pol)) {
944                 err = PTR_ERR(pol);
945                 pol = NULL;
946         }
947 #ifdef CONFIG_XFRM_SUB_POLICY
948 end:
949 #endif
950         if ((*objp = (void *) pol) != NULL)
951                 *obj_refp = &pol->refcnt;
952         return err;
953 }
954
955 static inline int policy_to_flow_dir(int dir)
956 {
957         if (XFRM_POLICY_IN == FLOW_DIR_IN &&
958             XFRM_POLICY_OUT == FLOW_DIR_OUT &&
959             XFRM_POLICY_FWD == FLOW_DIR_FWD)
960                 return dir;
961         switch (dir) {
962         default:
963         case XFRM_POLICY_IN:
964                 return FLOW_DIR_IN;
965         case XFRM_POLICY_OUT:
966                 return FLOW_DIR_OUT;
967         case XFRM_POLICY_FWD:
968                 return FLOW_DIR_FWD;
969         }
970 }
971
972 static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl)
973 {
974         struct xfrm_policy *pol;
975
976         read_lock_bh(&xfrm_policy_lock);
977         if ((pol = sk->sk_policy[dir]) != NULL) {
978                 int match = xfrm_selector_match(&pol->selector, fl,
979                                                 sk->sk_family);
980                 int err = 0;
981
982                 if (match) {
983                         err = security_xfrm_policy_lookup(pol, fl->secid,
984                                         policy_to_flow_dir(dir));
985                         if (!err)
986                                 xfrm_pol_hold(pol);
987                         else if (err == -ESRCH)
988                                 pol = NULL;
989                         else
990                                 pol = ERR_PTR(err);
991                 } else
992                         pol = NULL;
993         }
994         read_unlock_bh(&xfrm_policy_lock);
995         return pol;
996 }
997
998 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
999 {
1000         struct hlist_head *chain = policy_hash_bysel(&pol->selector,
1001                                                      pol->family, dir);
1002
1003         hlist_add_head(&pol->bydst, chain);
1004         hlist_add_head(&pol->byidx, xfrm_policy_byidx+idx_hash(pol->index));
1005         xfrm_policy_count[dir]++;
1006         xfrm_pol_hold(pol);
1007
1008         if (xfrm_bydst_should_resize(dir, NULL))
1009                 schedule_work(&xfrm_hash_work);
1010 }
1011
1012 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
1013                                                 int dir)
1014 {
1015         if (hlist_unhashed(&pol->bydst))
1016                 return NULL;
1017
1018         hlist_del(&pol->bydst);
1019         hlist_del(&pol->byidx);
1020         xfrm_policy_count[dir]--;
1021
1022         return pol;
1023 }
1024
1025 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
1026 {
1027         write_lock_bh(&xfrm_policy_lock);
1028         pol = __xfrm_policy_unlink(pol, dir);
1029         write_unlock_bh(&xfrm_policy_lock);
1030         if (pol) {
1031                 if (dir < XFRM_POLICY_MAX)
1032                         atomic_inc(&flow_cache_genid);
1033                 xfrm_policy_kill(pol);
1034                 return 0;
1035         }
1036         return -ENOENT;
1037 }
1038 EXPORT_SYMBOL(xfrm_policy_delete);
1039
1040 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
1041 {
1042         struct xfrm_policy *old_pol;
1043
1044 #ifdef CONFIG_XFRM_SUB_POLICY
1045         if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
1046                 return -EINVAL;
1047 #endif
1048
1049         write_lock_bh(&xfrm_policy_lock);
1050         old_pol = sk->sk_policy[dir];
1051         sk->sk_policy[dir] = pol;
1052         if (pol) {
1053                 pol->curlft.add_time = get_seconds();
1054                 pol->index = xfrm_gen_index(pol->type, XFRM_POLICY_MAX+dir);
1055                 __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
1056         }
1057         if (old_pol)
1058                 __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
1059         write_unlock_bh(&xfrm_policy_lock);
1060
1061         if (old_pol) {
1062                 xfrm_policy_kill(old_pol);
1063         }
1064         return 0;
1065 }
1066
1067 static struct xfrm_policy *clone_policy(struct xfrm_policy *old, int dir)
1068 {
1069         struct xfrm_policy *newp = xfrm_policy_alloc(GFP_ATOMIC);
1070
1071         if (newp) {
1072                 newp->selector = old->selector;
1073                 if (security_xfrm_policy_clone(old, newp)) {
1074                         kfree(newp);
1075                         return NULL;  /* ENOMEM */
1076                 }
1077                 newp->lft = old->lft;
1078                 newp->curlft = old->curlft;
1079                 newp->action = old->action;
1080                 newp->flags = old->flags;
1081                 newp->xfrm_nr = old->xfrm_nr;
1082                 newp->index = old->index;
1083                 newp->type = old->type;
1084                 memcpy(newp->xfrm_vec, old->xfrm_vec,
1085                        newp->xfrm_nr*sizeof(struct xfrm_tmpl));
1086                 write_lock_bh(&xfrm_policy_lock);
1087                 __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir);
1088                 write_unlock_bh(&xfrm_policy_lock);
1089                 xfrm_pol_put(newp);
1090         }
1091         return newp;
1092 }
1093
1094 int __xfrm_sk_clone_policy(struct sock *sk)
1095 {
1096         struct xfrm_policy *p0 = sk->sk_policy[0],
1097                            *p1 = sk->sk_policy[1];
1098
1099         sk->sk_policy[0] = sk->sk_policy[1] = NULL;
1100         if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL)
1101                 return -ENOMEM;
1102         if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL)
1103                 return -ENOMEM;
1104         return 0;
1105 }
1106
1107 static int
1108 xfrm_get_saddr(xfrm_address_t *local, xfrm_address_t *remote,
1109                unsigned short family)
1110 {
1111         int err;
1112         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1113
1114         if (unlikely(afinfo == NULL))
1115                 return -EINVAL;
1116         err = afinfo->get_saddr(local, remote);
1117         xfrm_policy_put_afinfo(afinfo);
1118         return err;
1119 }
1120
1121 /* Resolve list of templates for the flow, given policy. */
1122
1123 static int
1124 xfrm_tmpl_resolve_one(struct xfrm_policy *policy, struct flowi *fl,
1125                       struct xfrm_state **xfrm,
1126                       unsigned short family)
1127 {
1128         int nx;
1129         int i, error;
1130         xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
1131         xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
1132         xfrm_address_t tmp;
1133
1134         for (nx=0, i = 0; i < policy->xfrm_nr; i++) {
1135                 struct xfrm_state *x;
1136                 xfrm_address_t *remote = daddr;
1137                 xfrm_address_t *local  = saddr;
1138                 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
1139
1140                 if (tmpl->mode == XFRM_MODE_TUNNEL ||
1141                     tmpl->mode == XFRM_MODE_BEET) {
1142                         remote = &tmpl->id.daddr;
1143                         local = &tmpl->saddr;
1144                         family = tmpl->encap_family;
1145                         if (xfrm_addr_any(local, family)) {
1146                                 error = xfrm_get_saddr(&tmp, remote, family);
1147                                 if (error)
1148                                         goto fail;
1149                                 local = &tmp;
1150                         }
1151                 }
1152
1153                 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
1154
1155                 if (x && x->km.state == XFRM_STATE_VALID) {
1156                         xfrm[nx++] = x;
1157                         daddr = remote;
1158                         saddr = local;
1159                         continue;
1160                 }
1161                 if (x) {
1162                         error = (x->km.state == XFRM_STATE_ERROR ?
1163                                  -EINVAL : -EAGAIN);
1164                         xfrm_state_put(x);
1165                 }
1166
1167                 if (!tmpl->optional)
1168                         goto fail;
1169         }
1170         return nx;
1171
1172 fail:
1173         for (nx--; nx>=0; nx--)
1174                 xfrm_state_put(xfrm[nx]);
1175         return error;
1176 }
1177
1178 static int
1179 xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, struct flowi *fl,
1180                   struct xfrm_state **xfrm,
1181                   unsigned short family)
1182 {
1183         struct xfrm_state *tp[XFRM_MAX_DEPTH];
1184         struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
1185         int cnx = 0;
1186         int error;
1187         int ret;
1188         int i;
1189
1190         for (i = 0; i < npols; i++) {
1191                 if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
1192                         error = -ENOBUFS;
1193                         goto fail;
1194                 }
1195
1196                 ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
1197                 if (ret < 0) {
1198                         error = ret;
1199                         goto fail;
1200                 } else
1201                         cnx += ret;
1202         }
1203
1204         /* found states are sorted for outbound processing */
1205         if (npols > 1)
1206                 xfrm_state_sort(xfrm, tpp, cnx, family);
1207
1208         return cnx;
1209
1210  fail:
1211         for (cnx--; cnx>=0; cnx--)
1212                 xfrm_state_put(tpp[cnx]);
1213         return error;
1214
1215 }
1216
1217 /* Check that the bundle accepts the flow and its components are
1218  * still valid.
1219  */
1220
1221 static struct dst_entry *
1222 xfrm_find_bundle(struct flowi *fl, struct xfrm_policy *policy, unsigned short family)
1223 {
1224         struct dst_entry *x;
1225         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1226         if (unlikely(afinfo == NULL))
1227                 return ERR_PTR(-EINVAL);
1228         x = afinfo->find_bundle(fl, policy);
1229         xfrm_policy_put_afinfo(afinfo);
1230         return x;
1231 }
1232
1233 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
1234  * all the metrics... Shortly, bundle a bundle.
1235  */
1236
1237 static int
1238 xfrm_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
1239                    struct flowi *fl, struct dst_entry **dst_p,
1240                    unsigned short family)
1241 {
1242         int err;
1243         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1244         if (unlikely(afinfo == NULL))
1245                 return -EINVAL;
1246         err = afinfo->bundle_create(policy, xfrm, nx, fl, dst_p);
1247         xfrm_policy_put_afinfo(afinfo);
1248         return err;
1249 }
1250
1251 static int inline
1252 xfrm_dst_alloc_copy(void **target, void *src, int size)
1253 {
1254         if (!*target) {
1255                 *target = kmalloc(size, GFP_ATOMIC);
1256                 if (!*target)
1257                         return -ENOMEM;
1258         }
1259         memcpy(*target, src, size);
1260         return 0;
1261 }
1262
1263 static int inline
1264 xfrm_dst_update_parent(struct dst_entry *dst, struct xfrm_selector *sel)
1265 {
1266 #ifdef CONFIG_XFRM_SUB_POLICY
1267         struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1268         return xfrm_dst_alloc_copy((void **)&(xdst->partner),
1269                                    sel, sizeof(*sel));
1270 #else
1271         return 0;
1272 #endif
1273 }
1274
1275 static int inline
1276 xfrm_dst_update_origin(struct dst_entry *dst, struct flowi *fl)
1277 {
1278 #ifdef CONFIG_XFRM_SUB_POLICY
1279         struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1280         return xfrm_dst_alloc_copy((void **)&(xdst->origin), fl, sizeof(*fl));
1281 #else
1282         return 0;
1283 #endif
1284 }
1285
1286 static int stale_bundle(struct dst_entry *dst);
1287
1288 /* Main function: finds/creates a bundle for given flow.
1289  *
1290  * At the moment we eat a raw IP route. Mostly to speed up lookups
1291  * on interfaces with disabled IPsec.
1292  */
1293 int __xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
1294                   struct sock *sk, int flags)
1295 {
1296         struct xfrm_policy *policy;
1297         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1298         int npols;
1299         int pol_dead;
1300         int xfrm_nr;
1301         int pi;
1302         struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
1303         struct dst_entry *dst, *dst_orig = *dst_p;
1304         int nx = 0;
1305         int err;
1306         u32 genid;
1307         u16 family;
1308         u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
1309
1310 restart:
1311         genid = atomic_read(&flow_cache_genid);
1312         policy = NULL;
1313         for (pi = 0; pi < ARRAY_SIZE(pols); pi++)
1314                 pols[pi] = NULL;
1315         npols = 0;
1316         pol_dead = 0;
1317         xfrm_nr = 0;
1318
1319         if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
1320                 policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
1321                 err = PTR_ERR(policy);
1322                 if (IS_ERR(policy))
1323                         goto dropdst;
1324         }
1325
1326         if (!policy) {
1327                 /* To accelerate a bit...  */
1328                 if ((dst_orig->flags & DST_NOXFRM) ||
1329                     !xfrm_policy_count[XFRM_POLICY_OUT])
1330                         return 0;
1331
1332                 policy = flow_cache_lookup(fl, dst_orig->ops->family,
1333                                            dir, xfrm_policy_lookup);
1334                 err = PTR_ERR(policy);
1335                 if (IS_ERR(policy))
1336                         goto dropdst;
1337         }
1338
1339         if (!policy)
1340                 return 0;
1341
1342         family = dst_orig->ops->family;
1343         policy->curlft.use_time = get_seconds();
1344         pols[0] = policy;
1345         npols ++;
1346         xfrm_nr += pols[0]->xfrm_nr;
1347
1348         switch (policy->action) {
1349         default:
1350         case XFRM_POLICY_BLOCK:
1351                 /* Prohibit the flow */
1352                 err = -EPERM;
1353                 goto error;
1354
1355         case XFRM_POLICY_ALLOW:
1356 #ifndef CONFIG_XFRM_SUB_POLICY
1357                 if (policy->xfrm_nr == 0) {
1358                         /* Flow passes not transformed. */
1359                         xfrm_pol_put(policy);
1360                         return 0;
1361                 }
1362 #endif
1363
1364                 /* Try to find matching bundle.
1365                  *
1366                  * LATER: help from flow cache. It is optional, this
1367                  * is required only for output policy.
1368                  */
1369                 dst = xfrm_find_bundle(fl, policy, family);
1370                 if (IS_ERR(dst)) {
1371                         err = PTR_ERR(dst);
1372                         goto error;
1373                 }
1374
1375                 if (dst)
1376                         break;
1377
1378 #ifdef CONFIG_XFRM_SUB_POLICY
1379                 if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1380                         pols[1] = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN,
1381                                                             fl, family,
1382                                                             XFRM_POLICY_OUT);
1383                         if (pols[1]) {
1384                                 if (IS_ERR(pols[1])) {
1385                                         err = PTR_ERR(pols[1]);
1386                                         goto error;
1387                                 }
1388                                 if (pols[1]->action == XFRM_POLICY_BLOCK) {
1389                                         err = -EPERM;
1390                                         goto error;
1391                                 }
1392                                 npols ++;
1393                                 xfrm_nr += pols[1]->xfrm_nr;
1394                         }
1395                 }
1396
1397                 /*
1398                  * Because neither flowi nor bundle information knows about
1399                  * transformation template size. On more than one policy usage
1400                  * we can realize whether all of them is bypass or not after
1401                  * they are searched. See above not-transformed bypass
1402                  * is surrounded by non-sub policy configuration, too.
1403                  */
1404                 if (xfrm_nr == 0) {
1405                         /* Flow passes not transformed. */
1406                         xfrm_pols_put(pols, npols);
1407                         return 0;
1408                 }
1409
1410 #endif
1411                 nx = xfrm_tmpl_resolve(pols, npols, fl, xfrm, family);
1412
1413                 if (unlikely(nx<0)) {
1414                         err = nx;
1415                         if (err == -EAGAIN && sysctl_xfrm_larval_drop) {
1416                                 /* EREMOTE tells the caller to generate
1417                                  * a one-shot blackhole route.
1418                                  */
1419                                 xfrm_pol_put(policy);
1420                                 return -EREMOTE;
1421                         }
1422                         if (err == -EAGAIN && flags) {
1423                                 DECLARE_WAITQUEUE(wait, current);
1424
1425                                 add_wait_queue(&km_waitq, &wait);
1426                                 set_current_state(TASK_INTERRUPTIBLE);
1427                                 schedule();
1428                                 set_current_state(TASK_RUNNING);
1429                                 remove_wait_queue(&km_waitq, &wait);
1430
1431                                 nx = xfrm_tmpl_resolve(pols, npols, fl, xfrm, family);
1432
1433                                 if (nx == -EAGAIN && signal_pending(current)) {
1434                                         err = -ERESTART;
1435                                         goto error;
1436                                 }
1437                                 if (nx == -EAGAIN ||
1438                                     genid != atomic_read(&flow_cache_genid)) {
1439                                         xfrm_pols_put(pols, npols);
1440                                         goto restart;
1441                                 }
1442                                 err = nx;
1443                         }
1444                         if (err < 0)
1445                                 goto error;
1446                 }
1447                 if (nx == 0) {
1448                         /* Flow passes not transformed. */
1449                         xfrm_pols_put(pols, npols);
1450                         return 0;
1451                 }
1452
1453                 dst = dst_orig;
1454                 err = xfrm_bundle_create(policy, xfrm, nx, fl, &dst, family);
1455
1456                 if (unlikely(err)) {
1457                         int i;
1458                         for (i=0; i<nx; i++)
1459                                 xfrm_state_put(xfrm[i]);
1460                         goto error;
1461                 }
1462
1463                 for (pi = 0; pi < npols; pi++) {
1464                         read_lock_bh(&pols[pi]->lock);
1465                         pol_dead |= pols[pi]->dead;
1466                         read_unlock_bh(&pols[pi]->lock);
1467                 }
1468
1469                 write_lock_bh(&policy->lock);
1470                 if (unlikely(pol_dead || stale_bundle(dst))) {
1471                         /* Wow! While we worked on resolving, this
1472                          * policy has gone. Retry. It is not paranoia,
1473                          * we just cannot enlist new bundle to dead object.
1474                          * We can't enlist stable bundles either.
1475                          */
1476                         write_unlock_bh(&policy->lock);
1477                         if (dst)
1478                                 dst_free(dst);
1479
1480                         err = -EHOSTUNREACH;
1481                         goto error;
1482                 }
1483
1484                 if (npols > 1)
1485                         err = xfrm_dst_update_parent(dst, &pols[1]->selector);
1486                 else
1487                         err = xfrm_dst_update_origin(dst, fl);
1488                 if (unlikely(err)) {
1489                         write_unlock_bh(&policy->lock);
1490                         if (dst)
1491                                 dst_free(dst);
1492                         goto error;
1493                 }
1494
1495                 dst->next = policy->bundles;
1496                 policy->bundles = dst;
1497                 dst_hold(dst);
1498                 write_unlock_bh(&policy->lock);
1499         }
1500         *dst_p = dst;
1501         dst_release(dst_orig);
1502         xfrm_pols_put(pols, npols);
1503         return 0;
1504
1505 error:
1506         xfrm_pols_put(pols, npols);
1507 dropdst:
1508         dst_release(dst_orig);
1509         *dst_p = NULL;
1510         return err;
1511 }
1512 EXPORT_SYMBOL(__xfrm_lookup);
1513
1514 int xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
1515                 struct sock *sk, int flags)
1516 {
1517         int err = __xfrm_lookup(dst_p, fl, sk, flags);
1518
1519         if (err == -EREMOTE) {
1520                 dst_release(*dst_p);
1521                 *dst_p = NULL;
1522                 err = -EAGAIN;
1523         }
1524
1525         return err;
1526 }
1527 EXPORT_SYMBOL(xfrm_lookup);
1528
1529 static inline int
1530 xfrm_secpath_reject(int idx, struct sk_buff *skb, struct flowi *fl)
1531 {
1532         struct xfrm_state *x;
1533
1534         if (!skb->sp || idx < 0 || idx >= skb->sp->len)
1535                 return 0;
1536         x = skb->sp->xvec[idx];
1537         if (!x->type->reject)
1538                 return 0;
1539         return x->type->reject(x, skb, fl);
1540 }
1541
1542 /* When skb is transformed back to its "native" form, we have to
1543  * check policy restrictions. At the moment we make this in maximally
1544  * stupid way. Shame on me. :-) Of course, connected sockets must
1545  * have policy cached at them.
1546  */
1547
1548 static inline int
1549 xfrm_state_ok(struct xfrm_tmpl *tmpl, struct xfrm_state *x,
1550               unsigned short family)
1551 {
1552         if (xfrm_state_kern(x))
1553                 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
1554         return  x->id.proto == tmpl->id.proto &&
1555                 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
1556                 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
1557                 x->props.mode == tmpl->mode &&
1558                 ((tmpl->aalgos & (1<<x->props.aalgo)) ||
1559                  !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
1560                 !(x->props.mode != XFRM_MODE_TRANSPORT &&
1561                   xfrm_state_addr_cmp(tmpl, x, family));
1562 }
1563
1564 /*
1565  * 0 or more than 0 is returned when validation is succeeded (either bypass
1566  * because of optional transport mode, or next index of the mathced secpath
1567  * state with the template.
1568  * -1 is returned when no matching template is found.
1569  * Otherwise "-2 - errored_index" is returned.
1570  */
1571 static inline int
1572 xfrm_policy_ok(struct xfrm_tmpl *tmpl, struct sec_path *sp, int start,
1573                unsigned short family)
1574 {
1575         int idx = start;
1576
1577         if (tmpl->optional) {
1578                 if (tmpl->mode == XFRM_MODE_TRANSPORT)
1579                         return start;
1580         } else
1581                 start = -1;
1582         for (; idx < sp->len; idx++) {
1583                 if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
1584                         return ++idx;
1585                 if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
1586                         if (start == -1)
1587                                 start = -2-idx;
1588                         break;
1589                 }
1590         }
1591         return start;
1592 }
1593
1594 int
1595 xfrm_decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family)
1596 {
1597         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1598         int err;
1599
1600         if (unlikely(afinfo == NULL))
1601                 return -EAFNOSUPPORT;
1602
1603         afinfo->decode_session(skb, fl);
1604         err = security_xfrm_decode_session(skb, &fl->secid);
1605         xfrm_policy_put_afinfo(afinfo);
1606         return err;
1607 }
1608 EXPORT_SYMBOL(xfrm_decode_session);
1609
1610 static inline int secpath_has_nontransport(struct sec_path *sp, int k, int *idxp)
1611 {
1612         for (; k < sp->len; k++) {
1613                 if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
1614                         *idxp = k;
1615                         return 1;
1616                 }
1617         }
1618
1619         return 0;
1620 }
1621
1622 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
1623                         unsigned short family)
1624 {
1625         struct xfrm_policy *pol;
1626         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1627         int npols = 0;
1628         int xfrm_nr;
1629         int pi;
1630         struct flowi fl;
1631         u8 fl_dir = policy_to_flow_dir(dir);
1632         int xerr_idx = -1;
1633
1634         if (xfrm_decode_session(skb, &fl, family) < 0)
1635                 return 0;
1636         nf_nat_decode_session(skb, &fl, family);
1637
1638         /* First, check used SA against their selectors. */
1639         if (skb->sp) {
1640                 int i;
1641
1642                 for (i=skb->sp->len-1; i>=0; i--) {
1643                         struct xfrm_state *x = skb->sp->xvec[i];
1644                         if (!xfrm_selector_match(&x->sel, &fl, family))
1645                                 return 0;
1646                 }
1647         }
1648
1649         pol = NULL;
1650         if (sk && sk->sk_policy[dir]) {
1651                 pol = xfrm_sk_policy_lookup(sk, dir, &fl);
1652                 if (IS_ERR(pol))
1653                         return 0;
1654         }
1655
1656         if (!pol)
1657                 pol = flow_cache_lookup(&fl, family, fl_dir,
1658                                         xfrm_policy_lookup);
1659
1660         if (IS_ERR(pol))
1661                 return 0;
1662
1663         if (!pol) {
1664                 if (skb->sp && secpath_has_nontransport(skb->sp, 0, &xerr_idx)) {
1665                         xfrm_secpath_reject(xerr_idx, skb, &fl);
1666                         return 0;
1667                 }
1668                 return 1;
1669         }
1670
1671         pol->curlft.use_time = get_seconds();
1672
1673         pols[0] = pol;
1674         npols ++;
1675 #ifdef CONFIG_XFRM_SUB_POLICY
1676         if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1677                 pols[1] = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN,
1678                                                     &fl, family,
1679                                                     XFRM_POLICY_IN);
1680                 if (pols[1]) {
1681                         if (IS_ERR(pols[1]))
1682                                 return 0;
1683                         pols[1]->curlft.use_time = get_seconds();
1684                         npols ++;
1685                 }
1686         }
1687 #endif
1688
1689         if (pol->action == XFRM_POLICY_ALLOW) {
1690                 struct sec_path *sp;
1691                 static struct sec_path dummy;
1692                 struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
1693                 struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
1694                 struct xfrm_tmpl **tpp = tp;
1695                 int ti = 0;
1696                 int i, k;
1697
1698                 if ((sp = skb->sp) == NULL)
1699                         sp = &dummy;
1700
1701                 for (pi = 0; pi < npols; pi++) {
1702                         if (pols[pi] != pol &&
1703                             pols[pi]->action != XFRM_POLICY_ALLOW)
1704                                 goto reject;
1705                         if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH)
1706                                 goto reject_error;
1707                         for (i = 0; i < pols[pi]->xfrm_nr; i++)
1708                                 tpp[ti++] = &pols[pi]->xfrm_vec[i];
1709                 }
1710                 xfrm_nr = ti;
1711                 if (npols > 1) {
1712                         xfrm_tmpl_sort(stp, tpp, xfrm_nr, family);
1713                         tpp = stp;
1714                 }
1715
1716                 /* For each tunnel xfrm, find the first matching tmpl.
1717                  * For each tmpl before that, find corresponding xfrm.
1718                  * Order is _important_. Later we will implement
1719                  * some barriers, but at the moment barriers
1720                  * are implied between each two transformations.
1721                  */
1722                 for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
1723                         k = xfrm_policy_ok(tpp[i], sp, k, family);
1724                         if (k < 0) {
1725                                 if (k < -1)
1726                                         /* "-2 - errored_index" returned */
1727                                         xerr_idx = -(2+k);
1728                                 goto reject;
1729                         }
1730                 }
1731
1732                 if (secpath_has_nontransport(sp, k, &xerr_idx))
1733                         goto reject;
1734
1735                 xfrm_pols_put(pols, npols);
1736                 return 1;
1737         }
1738
1739 reject:
1740         xfrm_secpath_reject(xerr_idx, skb, &fl);
1741 reject_error:
1742         xfrm_pols_put(pols, npols);
1743         return 0;
1744 }
1745 EXPORT_SYMBOL(__xfrm_policy_check);
1746
1747 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
1748 {
1749         struct flowi fl;
1750
1751         if (xfrm_decode_session(skb, &fl, family) < 0)
1752                 return 0;
1753
1754         return xfrm_lookup(&skb->dst, &fl, NULL, 0) == 0;
1755 }
1756 EXPORT_SYMBOL(__xfrm_route_forward);
1757
1758 /* Optimize later using cookies and generation ids. */
1759
1760 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
1761 {
1762         /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
1763          * to "-1" to force all XFRM destinations to get validated by
1764          * dst_ops->check on every use.  We do this because when a
1765          * normal route referenced by an XFRM dst is obsoleted we do
1766          * not go looking around for all parent referencing XFRM dsts
1767          * so that we can invalidate them.  It is just too much work.
1768          * Instead we make the checks here on every use.  For example:
1769          *
1770          *      XFRM dst A --> IPv4 dst X
1771          *
1772          * X is the "xdst->route" of A (X is also the "dst->path" of A
1773          * in this example).  If X is marked obsolete, "A" will not
1774          * notice.  That's what we are validating here via the
1775          * stale_bundle() check.
1776          *
1777          * When a policy's bundle is pruned, we dst_free() the XFRM
1778          * dst which causes it's ->obsolete field to be set to a
1779          * positive non-zero integer.  If an XFRM dst has been pruned
1780          * like this, we want to force a new route lookup.
1781          */
1782         if (dst->obsolete < 0 && !stale_bundle(dst))
1783                 return dst;
1784
1785         return NULL;
1786 }
1787
1788 static int stale_bundle(struct dst_entry *dst)
1789 {
1790         return !xfrm_bundle_ok(NULL, (struct xfrm_dst *)dst, NULL, AF_UNSPEC, 0);
1791 }
1792
1793 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
1794 {
1795         while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
1796                 dst->dev = init_net.loopback_dev;
1797                 dev_hold(dst->dev);
1798                 dev_put(dev);
1799         }
1800 }
1801 EXPORT_SYMBOL(xfrm_dst_ifdown);
1802
1803 static void xfrm_link_failure(struct sk_buff *skb)
1804 {
1805         /* Impossible. Such dst must be popped before reaches point of failure. */
1806         return;
1807 }
1808
1809 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
1810 {
1811         if (dst) {
1812                 if (dst->obsolete) {
1813                         dst_release(dst);
1814                         dst = NULL;
1815                 }
1816         }
1817         return dst;
1818 }
1819
1820 static void prune_one_bundle(struct xfrm_policy *pol, int (*func)(struct dst_entry *), struct dst_entry **gc_list_p)
1821 {
1822         struct dst_entry *dst, **dstp;
1823
1824         write_lock(&pol->lock);
1825         dstp = &pol->bundles;
1826         while ((dst=*dstp) != NULL) {
1827                 if (func(dst)) {
1828                         *dstp = dst->next;
1829                         dst->next = *gc_list_p;
1830                         *gc_list_p = dst;
1831                 } else {
1832                         dstp = &dst->next;
1833                 }
1834         }
1835         write_unlock(&pol->lock);
1836 }
1837
1838 static void xfrm_prune_bundles(int (*func)(struct dst_entry *))
1839 {
1840         struct dst_entry *gc_list = NULL;
1841         int dir;
1842
1843         read_lock_bh(&xfrm_policy_lock);
1844         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
1845                 struct xfrm_policy *pol;
1846                 struct hlist_node *entry;
1847                 struct hlist_head *table;
1848                 int i;
1849
1850                 hlist_for_each_entry(pol, entry,
1851                                      &xfrm_policy_inexact[dir], bydst)
1852                         prune_one_bundle(pol, func, &gc_list);
1853
1854                 table = xfrm_policy_bydst[dir].table;
1855                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
1856                         hlist_for_each_entry(pol, entry, table + i, bydst)
1857                                 prune_one_bundle(pol, func, &gc_list);
1858                 }
1859         }
1860         read_unlock_bh(&xfrm_policy_lock);
1861
1862         while (gc_list) {
1863                 struct dst_entry *dst = gc_list;
1864                 gc_list = dst->next;
1865                 dst_free(dst);
1866         }
1867 }
1868
1869 static int unused_bundle(struct dst_entry *dst)
1870 {
1871         return !atomic_read(&dst->__refcnt);
1872 }
1873
1874 static void __xfrm_garbage_collect(void)
1875 {
1876         xfrm_prune_bundles(unused_bundle);
1877 }
1878
1879 static int xfrm_flush_bundles(void)
1880 {
1881         xfrm_prune_bundles(stale_bundle);
1882         return 0;
1883 }
1884
1885 void xfrm_init_pmtu(struct dst_entry *dst)
1886 {
1887         do {
1888                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1889                 u32 pmtu, route_mtu_cached;
1890
1891                 pmtu = dst_mtu(dst->child);
1892                 xdst->child_mtu_cached = pmtu;
1893
1894                 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
1895
1896                 route_mtu_cached = dst_mtu(xdst->route);
1897                 xdst->route_mtu_cached = route_mtu_cached;
1898
1899                 if (pmtu > route_mtu_cached)
1900                         pmtu = route_mtu_cached;
1901
1902                 dst->metrics[RTAX_MTU-1] = pmtu;
1903         } while ((dst = dst->next));
1904 }
1905
1906 EXPORT_SYMBOL(xfrm_init_pmtu);
1907
1908 /* Check that the bundle accepts the flow and its components are
1909  * still valid.
1910  */
1911
1912 int xfrm_bundle_ok(struct xfrm_policy *pol, struct xfrm_dst *first,
1913                 struct flowi *fl, int family, int strict)
1914 {
1915         struct dst_entry *dst = &first->u.dst;
1916         struct xfrm_dst *last;
1917         u32 mtu;
1918
1919         if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) ||
1920             (dst->dev && !netif_running(dst->dev)))
1921                 return 0;
1922 #ifdef CONFIG_XFRM_SUB_POLICY
1923         if (fl) {
1924                 if (first->origin && !flow_cache_uli_match(first->origin, fl))
1925                         return 0;
1926                 if (first->partner &&
1927                     !xfrm_selector_match(first->partner, fl, family))
1928                         return 0;
1929         }
1930 #endif
1931
1932         last = NULL;
1933
1934         do {
1935                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1936
1937                 if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family))
1938                         return 0;
1939                 if (fl && pol &&
1940                     !security_xfrm_state_pol_flow_match(dst->xfrm, pol, fl))
1941                         return 0;
1942                 if (dst->xfrm->km.state != XFRM_STATE_VALID)
1943                         return 0;
1944                 if (xdst->genid != dst->xfrm->genid)
1945                         return 0;
1946
1947                 if (strict && fl &&
1948                     !(dst->xfrm->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) &&
1949                     !xfrm_state_addr_flow_check(dst->xfrm, fl, family))
1950                         return 0;
1951
1952                 mtu = dst_mtu(dst->child);
1953                 if (xdst->child_mtu_cached != mtu) {
1954                         last = xdst;
1955                         xdst->child_mtu_cached = mtu;
1956                 }
1957
1958                 if (!dst_check(xdst->route, xdst->route_cookie))
1959                         return 0;
1960                 mtu = dst_mtu(xdst->route);
1961                 if (xdst->route_mtu_cached != mtu) {
1962                         last = xdst;
1963                         xdst->route_mtu_cached = mtu;
1964                 }
1965
1966                 dst = dst->child;
1967         } while (dst->xfrm);
1968
1969         if (likely(!last))
1970                 return 1;
1971
1972         mtu = last->child_mtu_cached;
1973         for (;;) {
1974                 dst = &last->u.dst;
1975
1976                 mtu = xfrm_state_mtu(dst->xfrm, mtu);
1977                 if (mtu > last->route_mtu_cached)
1978                         mtu = last->route_mtu_cached;
1979                 dst->metrics[RTAX_MTU-1] = mtu;
1980
1981                 if (last == first)
1982                         break;
1983
1984                 last = (struct xfrm_dst *)last->u.dst.next;
1985                 last->child_mtu_cached = mtu;
1986         }
1987
1988         return 1;
1989 }
1990
1991 EXPORT_SYMBOL(xfrm_bundle_ok);
1992
1993 int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
1994 {
1995         int err = 0;
1996         if (unlikely(afinfo == NULL))
1997                 return -EINVAL;
1998         if (unlikely(afinfo->family >= NPROTO))
1999                 return -EAFNOSUPPORT;
2000         write_lock_bh(&xfrm_policy_afinfo_lock);
2001         if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
2002                 err = -ENOBUFS;
2003         else {
2004                 struct dst_ops *dst_ops = afinfo->dst_ops;
2005                 if (likely(dst_ops->kmem_cachep == NULL))
2006                         dst_ops->kmem_cachep = xfrm_dst_cache;
2007                 if (likely(dst_ops->check == NULL))
2008                         dst_ops->check = xfrm_dst_check;
2009                 if (likely(dst_ops->negative_advice == NULL))
2010                         dst_ops->negative_advice = xfrm_negative_advice;
2011                 if (likely(dst_ops->link_failure == NULL))
2012                         dst_ops->link_failure = xfrm_link_failure;
2013                 if (likely(afinfo->garbage_collect == NULL))
2014                         afinfo->garbage_collect = __xfrm_garbage_collect;
2015                 xfrm_policy_afinfo[afinfo->family] = afinfo;
2016         }
2017         write_unlock_bh(&xfrm_policy_afinfo_lock);
2018         return err;
2019 }
2020 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
2021
2022 int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
2023 {
2024         int err = 0;
2025         if (unlikely(afinfo == NULL))
2026                 return -EINVAL;
2027         if (unlikely(afinfo->family >= NPROTO))
2028                 return -EAFNOSUPPORT;
2029         write_lock_bh(&xfrm_policy_afinfo_lock);
2030         if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
2031                 if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
2032                         err = -EINVAL;
2033                 else {
2034                         struct dst_ops *dst_ops = afinfo->dst_ops;
2035                         xfrm_policy_afinfo[afinfo->family] = NULL;
2036                         dst_ops->kmem_cachep = NULL;
2037                         dst_ops->check = NULL;
2038                         dst_ops->negative_advice = NULL;
2039                         dst_ops->link_failure = NULL;
2040                         afinfo->garbage_collect = NULL;
2041                 }
2042         }
2043         write_unlock_bh(&xfrm_policy_afinfo_lock);
2044         return err;
2045 }
2046 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
2047
2048 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
2049 {
2050         struct xfrm_policy_afinfo *afinfo;
2051         if (unlikely(family >= NPROTO))
2052                 return NULL;
2053         read_lock(&xfrm_policy_afinfo_lock);
2054         afinfo = xfrm_policy_afinfo[family];
2055         if (unlikely(!afinfo))
2056                 read_unlock(&xfrm_policy_afinfo_lock);
2057         return afinfo;
2058 }
2059
2060 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
2061 {
2062         read_unlock(&xfrm_policy_afinfo_lock);
2063 }
2064
2065 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
2066 {
2067         struct net_device *dev = ptr;
2068
2069         if (dev->nd_net != &init_net)
2070                 return NOTIFY_DONE;
2071
2072         switch (event) {
2073         case NETDEV_DOWN:
2074                 xfrm_flush_bundles();
2075         }
2076         return NOTIFY_DONE;
2077 }
2078
2079 static struct notifier_block xfrm_dev_notifier = {
2080         xfrm_dev_event,
2081         NULL,
2082         0
2083 };
2084
2085 static void __init xfrm_policy_init(void)
2086 {
2087         unsigned int hmask, sz;
2088         int dir;
2089
2090         xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
2091                                            sizeof(struct xfrm_dst),
2092                                            0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
2093                                            NULL);
2094
2095         hmask = 8 - 1;
2096         sz = (hmask+1) * sizeof(struct hlist_head);
2097
2098         xfrm_policy_byidx = xfrm_hash_alloc(sz);
2099         xfrm_idx_hmask = hmask;
2100         if (!xfrm_policy_byidx)
2101                 panic("XFRM: failed to allocate byidx hash\n");
2102
2103         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
2104                 struct xfrm_policy_hash *htab;
2105
2106                 INIT_HLIST_HEAD(&xfrm_policy_inexact[dir]);
2107
2108                 htab = &xfrm_policy_bydst[dir];
2109                 htab->table = xfrm_hash_alloc(sz);
2110                 htab->hmask = hmask;
2111                 if (!htab->table)
2112                         panic("XFRM: failed to allocate bydst hash\n");
2113         }
2114
2115         INIT_WORK(&xfrm_policy_gc_work, xfrm_policy_gc_task);
2116         register_netdevice_notifier(&xfrm_dev_notifier);
2117 }
2118
2119 void __init xfrm_init(void)
2120 {
2121         xfrm_state_init();
2122         xfrm_policy_init();
2123         xfrm_input_init();
2124 }
2125
2126 #ifdef CONFIG_AUDITSYSCALL
2127 static inline void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
2128                                                 struct audit_buffer *audit_buf)
2129 {
2130         if (xp->security)
2131                 audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
2132                                  xp->security->ctx_alg, xp->security->ctx_doi,
2133                                  xp->security->ctx_str);
2134
2135         switch(xp->selector.family) {
2136         case AF_INET:
2137                 audit_log_format(audit_buf, " src=%u.%u.%u.%u dst=%u.%u.%u.%u",
2138                                  NIPQUAD(xp->selector.saddr.a4),
2139                                  NIPQUAD(xp->selector.daddr.a4));
2140                 break;
2141         case AF_INET6:
2142                 {
2143                         struct in6_addr saddr6, daddr6;
2144
2145                         memcpy(&saddr6, xp->selector.saddr.a6,
2146                                 sizeof(struct in6_addr));
2147                         memcpy(&daddr6, xp->selector.daddr.a6,
2148                                 sizeof(struct in6_addr));
2149                         audit_log_format(audit_buf,
2150                                 " src=" NIP6_FMT " dst=" NIP6_FMT,
2151                                 NIP6(saddr6), NIP6(daddr6));
2152                 }
2153                 break;
2154         }
2155 }
2156
2157 void
2158 xfrm_audit_policy_add(struct xfrm_policy *xp, int result, u32 auid, u32 sid)
2159 {
2160         struct audit_buffer *audit_buf;
2161         extern int audit_enabled;
2162
2163         if (audit_enabled == 0)
2164                 return;
2165         audit_buf = xfrm_audit_start(auid, sid);
2166         if (audit_buf == NULL)
2167                 return;
2168         audit_log_format(audit_buf, " op=SPD-add res=%u", result);
2169         xfrm_audit_common_policyinfo(xp, audit_buf);
2170         audit_log_end(audit_buf);
2171 }
2172 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
2173
2174 void
2175 xfrm_audit_policy_delete(struct xfrm_policy *xp, int result, u32 auid, u32 sid)
2176 {
2177         struct audit_buffer *audit_buf;
2178         extern int audit_enabled;
2179
2180         if (audit_enabled == 0)
2181                 return;
2182         audit_buf = xfrm_audit_start(auid, sid);
2183         if (audit_buf == NULL)
2184                 return;
2185         audit_log_format(audit_buf, " op=SPD-delete res=%u", result);
2186         xfrm_audit_common_policyinfo(xp, audit_buf);
2187         audit_log_end(audit_buf);
2188 }
2189 EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
2190 #endif
2191
2192 #ifdef CONFIG_XFRM_MIGRATE
2193 static int xfrm_migrate_selector_match(struct xfrm_selector *sel_cmp,
2194                                        struct xfrm_selector *sel_tgt)
2195 {
2196         if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
2197                 if (sel_tgt->family == sel_cmp->family &&
2198                     xfrm_addr_cmp(&sel_tgt->daddr, &sel_cmp->daddr,
2199                                   sel_cmp->family) == 0 &&
2200                     xfrm_addr_cmp(&sel_tgt->saddr, &sel_cmp->saddr,
2201                                   sel_cmp->family) == 0 &&
2202                     sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
2203                     sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
2204                         return 1;
2205                 }
2206         } else {
2207                 if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
2208                         return 1;
2209                 }
2210         }
2211         return 0;
2212 }
2213
2214 static struct xfrm_policy * xfrm_migrate_policy_find(struct xfrm_selector *sel,
2215                                                      u8 dir, u8 type)
2216 {
2217         struct xfrm_policy *pol, *ret = NULL;
2218         struct hlist_node *entry;
2219         struct hlist_head *chain;
2220         u32 priority = ~0U;
2221
2222         read_lock_bh(&xfrm_policy_lock);
2223         chain = policy_hash_direct(&sel->daddr, &sel->saddr, sel->family, dir);
2224         hlist_for_each_entry(pol, entry, chain, bydst) {
2225                 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
2226                     pol->type == type) {
2227                         ret = pol;
2228                         priority = ret->priority;
2229                         break;
2230                 }
2231         }
2232         chain = &xfrm_policy_inexact[dir];
2233         hlist_for_each_entry(pol, entry, chain, bydst) {
2234                 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
2235                     pol->type == type &&
2236                     pol->priority < priority) {
2237                         ret = pol;
2238                         break;
2239                 }
2240         }
2241
2242         if (ret)
2243                 xfrm_pol_hold(ret);
2244
2245         read_unlock_bh(&xfrm_policy_lock);
2246
2247         return ret;
2248 }
2249
2250 static int migrate_tmpl_match(struct xfrm_migrate *m, struct xfrm_tmpl *t)
2251 {
2252         int match = 0;
2253
2254         if (t->mode == m->mode && t->id.proto == m->proto &&
2255             (m->reqid == 0 || t->reqid == m->reqid)) {
2256                 switch (t->mode) {
2257                 case XFRM_MODE_TUNNEL:
2258                 case XFRM_MODE_BEET:
2259                         if (xfrm_addr_cmp(&t->id.daddr, &m->old_daddr,
2260                                           m->old_family) == 0 &&
2261                             xfrm_addr_cmp(&t->saddr, &m->old_saddr,
2262                                           m->old_family) == 0) {
2263                                 match = 1;
2264                         }
2265                         break;
2266                 case XFRM_MODE_TRANSPORT:
2267                         /* in case of transport mode, template does not store
2268                            any IP addresses, hence we just compare mode and
2269                            protocol */
2270                         match = 1;
2271                         break;
2272                 default:
2273                         break;
2274                 }
2275         }
2276         return match;
2277 }
2278
2279 /* update endpoint address(es) of template(s) */
2280 static int xfrm_policy_migrate(struct xfrm_policy *pol,
2281                                struct xfrm_migrate *m, int num_migrate)
2282 {
2283         struct xfrm_migrate *mp;
2284         struct dst_entry *dst;
2285         int i, j, n = 0;
2286
2287         write_lock_bh(&pol->lock);
2288         if (unlikely(pol->dead)) {
2289                 /* target policy has been deleted */
2290                 write_unlock_bh(&pol->lock);
2291                 return -ENOENT;
2292         }
2293
2294         for (i = 0; i < pol->xfrm_nr; i++) {
2295                 for (j = 0, mp = m; j < num_migrate; j++, mp++) {
2296                         if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
2297                                 continue;
2298                         n++;
2299                         if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
2300                             pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
2301                                 continue;
2302                         /* update endpoints */
2303                         memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
2304                                sizeof(pol->xfrm_vec[i].id.daddr));
2305                         memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
2306                                sizeof(pol->xfrm_vec[i].saddr));
2307                         pol->xfrm_vec[i].encap_family = mp->new_family;
2308                         /* flush bundles */
2309                         while ((dst = pol->bundles) != NULL) {
2310                                 pol->bundles = dst->next;
2311                                 dst_free(dst);
2312                         }
2313                 }
2314         }
2315
2316         write_unlock_bh(&pol->lock);
2317
2318         if (!n)
2319                 return -ENODATA;
2320
2321         return 0;
2322 }
2323
2324 static int xfrm_migrate_check(struct xfrm_migrate *m, int num_migrate)
2325 {
2326         int i, j;
2327
2328         if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
2329                 return -EINVAL;
2330
2331         for (i = 0; i < num_migrate; i++) {
2332                 if ((xfrm_addr_cmp(&m[i].old_daddr, &m[i].new_daddr,
2333                                    m[i].old_family) == 0) &&
2334                     (xfrm_addr_cmp(&m[i].old_saddr, &m[i].new_saddr,
2335                                    m[i].old_family) == 0))
2336                         return -EINVAL;
2337                 if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
2338                     xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
2339                         return -EINVAL;
2340
2341                 /* check if there is any duplicated entry */
2342                 for (j = i + 1; j < num_migrate; j++) {
2343                         if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
2344                                     sizeof(m[i].old_daddr)) &&
2345                             !memcmp(&m[i].old_saddr, &m[j].old_saddr,
2346                                     sizeof(m[i].old_saddr)) &&
2347                             m[i].proto == m[j].proto &&
2348                             m[i].mode == m[j].mode &&
2349                             m[i].reqid == m[j].reqid &&
2350                             m[i].old_family == m[j].old_family)
2351                                 return -EINVAL;
2352                 }
2353         }
2354
2355         return 0;
2356 }
2357
2358 int xfrm_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
2359                  struct xfrm_migrate *m, int num_migrate)
2360 {
2361         int i, err, nx_cur = 0, nx_new = 0;
2362         struct xfrm_policy *pol = NULL;
2363         struct xfrm_state *x, *xc;
2364         struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
2365         struct xfrm_state *x_new[XFRM_MAX_DEPTH];
2366         struct xfrm_migrate *mp;
2367
2368         if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
2369                 goto out;
2370
2371         /* Stage 1 - find policy */
2372         if ((pol = xfrm_migrate_policy_find(sel, dir, type)) == NULL) {
2373                 err = -ENOENT;
2374                 goto out;
2375         }
2376
2377         /* Stage 2 - find and update state(s) */
2378         for (i = 0, mp = m; i < num_migrate; i++, mp++) {
2379                 if ((x = xfrm_migrate_state_find(mp))) {
2380                         x_cur[nx_cur] = x;
2381                         nx_cur++;
2382                         if ((xc = xfrm_state_migrate(x, mp))) {
2383                                 x_new[nx_new] = xc;
2384                                 nx_new++;
2385                         } else {
2386                                 err = -ENODATA;
2387                                 goto restore_state;
2388                         }
2389                 }
2390         }
2391
2392         /* Stage 3 - update policy */
2393         if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
2394                 goto restore_state;
2395
2396         /* Stage 4 - delete old state(s) */
2397         if (nx_cur) {
2398                 xfrm_states_put(x_cur, nx_cur);
2399                 xfrm_states_delete(x_cur, nx_cur);
2400         }
2401
2402         /* Stage 5 - announce */
2403         km_migrate(sel, dir, type, m, num_migrate);
2404
2405         xfrm_pol_put(pol);
2406
2407         return 0;
2408 out:
2409         return err;
2410
2411 restore_state:
2412         if (pol)
2413                 xfrm_pol_put(pol);
2414         if (nx_cur)
2415                 xfrm_states_put(x_cur, nx_cur);
2416         if (nx_new)
2417                 xfrm_states_delete(x_new, nx_new);
2418
2419         return err;
2420 }
2421 EXPORT_SYMBOL(xfrm_migrate);
2422 #endif