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[linux-3.10.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/err.h>
17 #include <linux/slab.h>
18 #include <linux/kmod.h>
19 #include <linux/list.h>
20 #include <linux/spinlock.h>
21 #include <linux/workqueue.h>
22 #include <linux/notifier.h>
23 #include <linux/netdevice.h>
24 #include <linux/netfilter.h>
25 #include <linux/module.h>
26 #include <linux/cache.h>
27 #include <linux/audit.h>
28 #include <net/dst.h>
29 #include <net/flow.h>
30 #include <net/xfrm.h>
31 #include <net/ip.h>
32 #ifdef CONFIG_XFRM_STATISTICS
33 #include <net/snmp.h>
34 #endif
35
36 #include "xfrm_hash.h"
37
38 DEFINE_MUTEX(xfrm_cfg_mutex);
39 EXPORT_SYMBOL(xfrm_cfg_mutex);
40
41 static DEFINE_SPINLOCK(xfrm_policy_sk_bundle_lock);
42 static struct dst_entry *xfrm_policy_sk_bundles;
43 static DEFINE_RWLOCK(xfrm_policy_lock);
44
45 static DEFINE_RWLOCK(xfrm_policy_afinfo_lock);
46 static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO];
47
48 static struct kmem_cache *xfrm_dst_cache __read_mostly;
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 static void xfrm_init_pmtu(struct dst_entry *dst);
53 static int stale_bundle(struct dst_entry *dst);
54 static int xfrm_bundle_ok(struct xfrm_dst *xdst);
55
56
57 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
58                                                 int dir);
59
60 static inline bool
61 __xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
62 {
63         const struct flowi4 *fl4 = &fl->u.ip4;
64
65         return  addr4_match(fl4->daddr, sel->daddr.a4, sel->prefixlen_d) &&
66                 addr4_match(fl4->saddr, sel->saddr.a4, sel->prefixlen_s) &&
67                 !((xfrm_flowi_dport(fl, &fl4->uli) ^ sel->dport) & sel->dport_mask) &&
68                 !((xfrm_flowi_sport(fl, &fl4->uli) ^ sel->sport) & sel->sport_mask) &&
69                 (fl4->flowi4_proto == sel->proto || !sel->proto) &&
70                 (fl4->flowi4_oif == sel->ifindex || !sel->ifindex);
71 }
72
73 static inline bool
74 __xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
75 {
76         const struct flowi6 *fl6 = &fl->u.ip6;
77
78         return  addr_match(&fl6->daddr, &sel->daddr, sel->prefixlen_d) &&
79                 addr_match(&fl6->saddr, &sel->saddr, sel->prefixlen_s) &&
80                 !((xfrm_flowi_dport(fl, &fl6->uli) ^ sel->dport) & sel->dport_mask) &&
81                 !((xfrm_flowi_sport(fl, &fl6->uli) ^ sel->sport) & sel->sport_mask) &&
82                 (fl6->flowi6_proto == sel->proto || !sel->proto) &&
83                 (fl6->flowi6_oif == sel->ifindex || !sel->ifindex);
84 }
85
86 bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl,
87                          unsigned short family)
88 {
89         switch (family) {
90         case AF_INET:
91                 return __xfrm4_selector_match(sel, fl);
92         case AF_INET6:
93                 return __xfrm6_selector_match(sel, fl);
94         }
95         return false;
96 }
97
98 static inline struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos,
99                                                   const xfrm_address_t *saddr,
100                                                   const xfrm_address_t *daddr,
101                                                   int family)
102 {
103         struct xfrm_policy_afinfo *afinfo;
104         struct dst_entry *dst;
105
106         afinfo = xfrm_policy_get_afinfo(family);
107         if (unlikely(afinfo == NULL))
108                 return ERR_PTR(-EAFNOSUPPORT);
109
110         dst = afinfo->dst_lookup(net, tos, saddr, daddr);
111
112         xfrm_policy_put_afinfo(afinfo);
113
114         return dst;
115 }
116
117 static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x, int tos,
118                                                 xfrm_address_t *prev_saddr,
119                                                 xfrm_address_t *prev_daddr,
120                                                 int family)
121 {
122         struct net *net = xs_net(x);
123         xfrm_address_t *saddr = &x->props.saddr;
124         xfrm_address_t *daddr = &x->id.daddr;
125         struct dst_entry *dst;
126
127         if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) {
128                 saddr = x->coaddr;
129                 daddr = prev_daddr;
130         }
131         if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) {
132                 saddr = prev_saddr;
133                 daddr = x->coaddr;
134         }
135
136         dst = __xfrm_dst_lookup(net, tos, saddr, daddr, family);
137
138         if (!IS_ERR(dst)) {
139                 if (prev_saddr != saddr)
140                         memcpy(prev_saddr, saddr,  sizeof(*prev_saddr));
141                 if (prev_daddr != daddr)
142                         memcpy(prev_daddr, daddr,  sizeof(*prev_daddr));
143         }
144
145         return dst;
146 }
147
148 static inline unsigned long make_jiffies(long secs)
149 {
150         if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
151                 return MAX_SCHEDULE_TIMEOUT-1;
152         else
153                 return secs*HZ;
154 }
155
156 static void xfrm_policy_timer(unsigned long data)
157 {
158         struct xfrm_policy *xp = (struct xfrm_policy*)data;
159         unsigned long now = get_seconds();
160         long next = LONG_MAX;
161         int warn = 0;
162         int dir;
163
164         read_lock(&xp->lock);
165
166         if (unlikely(xp->walk.dead))
167                 goto out;
168
169         dir = xfrm_policy_id2dir(xp->index);
170
171         if (xp->lft.hard_add_expires_seconds) {
172                 long tmo = xp->lft.hard_add_expires_seconds +
173                         xp->curlft.add_time - now;
174                 if (tmo <= 0)
175                         goto expired;
176                 if (tmo < next)
177                         next = tmo;
178         }
179         if (xp->lft.hard_use_expires_seconds) {
180                 long tmo = xp->lft.hard_use_expires_seconds +
181                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
182                 if (tmo <= 0)
183                         goto expired;
184                 if (tmo < next)
185                         next = tmo;
186         }
187         if (xp->lft.soft_add_expires_seconds) {
188                 long tmo = xp->lft.soft_add_expires_seconds +
189                         xp->curlft.add_time - now;
190                 if (tmo <= 0) {
191                         warn = 1;
192                         tmo = XFRM_KM_TIMEOUT;
193                 }
194                 if (tmo < next)
195                         next = tmo;
196         }
197         if (xp->lft.soft_use_expires_seconds) {
198                 long tmo = xp->lft.soft_use_expires_seconds +
199                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
200                 if (tmo <= 0) {
201                         warn = 1;
202                         tmo = XFRM_KM_TIMEOUT;
203                 }
204                 if (tmo < next)
205                         next = tmo;
206         }
207
208         if (warn)
209                 km_policy_expired(xp, dir, 0, 0);
210         if (next != LONG_MAX &&
211             !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
212                 xfrm_pol_hold(xp);
213
214 out:
215         read_unlock(&xp->lock);
216         xfrm_pol_put(xp);
217         return;
218
219 expired:
220         read_unlock(&xp->lock);
221         if (!xfrm_policy_delete(xp, dir))
222                 km_policy_expired(xp, dir, 1, 0);
223         xfrm_pol_put(xp);
224 }
225
226 static struct flow_cache_object *xfrm_policy_flo_get(struct flow_cache_object *flo)
227 {
228         struct xfrm_policy *pol = container_of(flo, struct xfrm_policy, flo);
229
230         if (unlikely(pol->walk.dead))
231                 flo = NULL;
232         else
233                 xfrm_pol_hold(pol);
234
235         return flo;
236 }
237
238 static int xfrm_policy_flo_check(struct flow_cache_object *flo)
239 {
240         struct xfrm_policy *pol = container_of(flo, struct xfrm_policy, flo);
241
242         return !pol->walk.dead;
243 }
244
245 static void xfrm_policy_flo_delete(struct flow_cache_object *flo)
246 {
247         xfrm_pol_put(container_of(flo, struct xfrm_policy, flo));
248 }
249
250 static const struct flow_cache_ops xfrm_policy_fc_ops = {
251         .get = xfrm_policy_flo_get,
252         .check = xfrm_policy_flo_check,
253         .delete = xfrm_policy_flo_delete,
254 };
255
256 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
257  * SPD calls.
258  */
259
260 struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
261 {
262         struct xfrm_policy *policy;
263
264         policy = kzalloc(sizeof(struct xfrm_policy), gfp);
265
266         if (policy) {
267                 write_pnet(&policy->xp_net, net);
268                 INIT_LIST_HEAD(&policy->walk.all);
269                 INIT_HLIST_NODE(&policy->bydst);
270                 INIT_HLIST_NODE(&policy->byidx);
271                 rwlock_init(&policy->lock);
272                 atomic_set(&policy->refcnt, 1);
273                 setup_timer(&policy->timer, xfrm_policy_timer,
274                                 (unsigned long)policy);
275                 policy->flo.ops = &xfrm_policy_fc_ops;
276         }
277         return policy;
278 }
279 EXPORT_SYMBOL(xfrm_policy_alloc);
280
281 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
282
283 void xfrm_policy_destroy(struct xfrm_policy *policy)
284 {
285         BUG_ON(!policy->walk.dead);
286
287         if (del_timer(&policy->timer))
288                 BUG();
289
290         security_xfrm_policy_free(policy->security);
291         kfree(policy);
292 }
293 EXPORT_SYMBOL(xfrm_policy_destroy);
294
295 /* Rule must be locked. Release descentant resources, announce
296  * entry dead. The rule must be unlinked from lists to the moment.
297  */
298
299 static void xfrm_policy_kill(struct xfrm_policy *policy)
300 {
301         policy->walk.dead = 1;
302
303         atomic_inc(&policy->genid);
304
305         if (del_timer(&policy->timer))
306                 xfrm_pol_put(policy);
307
308         xfrm_pol_put(policy);
309 }
310
311 static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
312
313 static inline unsigned int idx_hash(struct net *net, u32 index)
314 {
315         return __idx_hash(index, net->xfrm.policy_idx_hmask);
316 }
317
318 static struct hlist_head *policy_hash_bysel(struct net *net,
319                                             const struct xfrm_selector *sel,
320                                             unsigned short family, int dir)
321 {
322         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
323         unsigned int hash = __sel_hash(sel, family, hmask);
324
325         return (hash == hmask + 1 ?
326                 &net->xfrm.policy_inexact[dir] :
327                 net->xfrm.policy_bydst[dir].table + hash);
328 }
329
330 static struct hlist_head *policy_hash_direct(struct net *net,
331                                              const xfrm_address_t *daddr,
332                                              const xfrm_address_t *saddr,
333                                              unsigned short family, int dir)
334 {
335         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
336         unsigned int hash = __addr_hash(daddr, saddr, family, hmask);
337
338         return net->xfrm.policy_bydst[dir].table + hash;
339 }
340
341 static void xfrm_dst_hash_transfer(struct hlist_head *list,
342                                    struct hlist_head *ndsttable,
343                                    unsigned int nhashmask)
344 {
345         struct hlist_node *entry, *tmp, *entry0 = NULL;
346         struct xfrm_policy *pol;
347         unsigned int h0 = 0;
348
349 redo:
350         hlist_for_each_entry_safe(pol, entry, tmp, list, bydst) {
351                 unsigned int h;
352
353                 h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
354                                 pol->family, nhashmask);
355                 if (!entry0) {
356                         hlist_del(entry);
357                         hlist_add_head(&pol->bydst, ndsttable+h);
358                         h0 = h;
359                 } else {
360                         if (h != h0)
361                                 continue;
362                         hlist_del(entry);
363                         hlist_add_after(entry0, &pol->bydst);
364                 }
365                 entry0 = entry;
366         }
367         if (!hlist_empty(list)) {
368                 entry0 = NULL;
369                 goto redo;
370         }
371 }
372
373 static void xfrm_idx_hash_transfer(struct hlist_head *list,
374                                    struct hlist_head *nidxtable,
375                                    unsigned int nhashmask)
376 {
377         struct hlist_node *entry, *tmp;
378         struct xfrm_policy *pol;
379
380         hlist_for_each_entry_safe(pol, entry, tmp, list, byidx) {
381                 unsigned int h;
382
383                 h = __idx_hash(pol->index, nhashmask);
384                 hlist_add_head(&pol->byidx, nidxtable+h);
385         }
386 }
387
388 static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
389 {
390         return ((old_hmask + 1) << 1) - 1;
391 }
392
393 static void xfrm_bydst_resize(struct net *net, int dir)
394 {
395         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
396         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
397         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
398         struct hlist_head *odst = net->xfrm.policy_bydst[dir].table;
399         struct hlist_head *ndst = xfrm_hash_alloc(nsize);
400         int i;
401
402         if (!ndst)
403                 return;
404
405         write_lock_bh(&xfrm_policy_lock);
406
407         for (i = hmask; i >= 0; i--)
408                 xfrm_dst_hash_transfer(odst + i, ndst, nhashmask);
409
410         net->xfrm.policy_bydst[dir].table = ndst;
411         net->xfrm.policy_bydst[dir].hmask = nhashmask;
412
413         write_unlock_bh(&xfrm_policy_lock);
414
415         xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
416 }
417
418 static void xfrm_byidx_resize(struct net *net, int total)
419 {
420         unsigned int hmask = net->xfrm.policy_idx_hmask;
421         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
422         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
423         struct hlist_head *oidx = net->xfrm.policy_byidx;
424         struct hlist_head *nidx = xfrm_hash_alloc(nsize);
425         int i;
426
427         if (!nidx)
428                 return;
429
430         write_lock_bh(&xfrm_policy_lock);
431
432         for (i = hmask; i >= 0; i--)
433                 xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
434
435         net->xfrm.policy_byidx = nidx;
436         net->xfrm.policy_idx_hmask = nhashmask;
437
438         write_unlock_bh(&xfrm_policy_lock);
439
440         xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
441 }
442
443 static inline int xfrm_bydst_should_resize(struct net *net, int dir, int *total)
444 {
445         unsigned int cnt = net->xfrm.policy_count[dir];
446         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
447
448         if (total)
449                 *total += cnt;
450
451         if ((hmask + 1) < xfrm_policy_hashmax &&
452             cnt > hmask)
453                 return 1;
454
455         return 0;
456 }
457
458 static inline int xfrm_byidx_should_resize(struct net *net, int total)
459 {
460         unsigned int hmask = net->xfrm.policy_idx_hmask;
461
462         if ((hmask + 1) < xfrm_policy_hashmax &&
463             total > hmask)
464                 return 1;
465
466         return 0;
467 }
468
469 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
470 {
471         read_lock_bh(&xfrm_policy_lock);
472         si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
473         si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
474         si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
475         si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
476         si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
477         si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
478         si->spdhcnt = net->xfrm.policy_idx_hmask;
479         si->spdhmcnt = xfrm_policy_hashmax;
480         read_unlock_bh(&xfrm_policy_lock);
481 }
482 EXPORT_SYMBOL(xfrm_spd_getinfo);
483
484 static DEFINE_MUTEX(hash_resize_mutex);
485 static void xfrm_hash_resize(struct work_struct *work)
486 {
487         struct net *net = container_of(work, struct net, xfrm.policy_hash_work);
488         int dir, total;
489
490         mutex_lock(&hash_resize_mutex);
491
492         total = 0;
493         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
494                 if (xfrm_bydst_should_resize(net, dir, &total))
495                         xfrm_bydst_resize(net, dir);
496         }
497         if (xfrm_byidx_should_resize(net, total))
498                 xfrm_byidx_resize(net, total);
499
500         mutex_unlock(&hash_resize_mutex);
501 }
502
503 /* Generate new index... KAME seems to generate them ordered by cost
504  * of an absolute inpredictability of ordering of rules. This will not pass. */
505 static u32 xfrm_gen_index(struct net *net, int dir)
506 {
507         static u32 idx_generator;
508
509         for (;;) {
510                 struct hlist_node *entry;
511                 struct hlist_head *list;
512                 struct xfrm_policy *p;
513                 u32 idx;
514                 int found;
515
516                 idx = (idx_generator | dir);
517                 idx_generator += 8;
518                 if (idx == 0)
519                         idx = 8;
520                 list = net->xfrm.policy_byidx + idx_hash(net, idx);
521                 found = 0;
522                 hlist_for_each_entry(p, entry, list, byidx) {
523                         if (p->index == idx) {
524                                 found = 1;
525                                 break;
526                         }
527                 }
528                 if (!found)
529                         return idx;
530         }
531 }
532
533 static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
534 {
535         u32 *p1 = (u32 *) s1;
536         u32 *p2 = (u32 *) s2;
537         int len = sizeof(struct xfrm_selector) / sizeof(u32);
538         int i;
539
540         for (i = 0; i < len; i++) {
541                 if (p1[i] != p2[i])
542                         return 1;
543         }
544
545         return 0;
546 }
547
548 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
549 {
550         struct net *net = xp_net(policy);
551         struct xfrm_policy *pol;
552         struct xfrm_policy *delpol;
553         struct hlist_head *chain;
554         struct hlist_node *entry, *newpos;
555         u32 mark = policy->mark.v & policy->mark.m;
556
557         write_lock_bh(&xfrm_policy_lock);
558         chain = policy_hash_bysel(net, &policy->selector, policy->family, dir);
559         delpol = NULL;
560         newpos = NULL;
561         hlist_for_each_entry(pol, entry, chain, bydst) {
562                 if (pol->type == policy->type &&
563                     !selector_cmp(&pol->selector, &policy->selector) &&
564                     (mark & pol->mark.m) == pol->mark.v &&
565                     xfrm_sec_ctx_match(pol->security, policy->security) &&
566                     !WARN_ON(delpol)) {
567                         if (excl) {
568                                 write_unlock_bh(&xfrm_policy_lock);
569                                 return -EEXIST;
570                         }
571                         delpol = pol;
572                         if (policy->priority > pol->priority)
573                                 continue;
574                 } else if (policy->priority >= pol->priority) {
575                         newpos = &pol->bydst;
576                         continue;
577                 }
578                 if (delpol)
579                         break;
580         }
581         if (newpos)
582                 hlist_add_after(newpos, &policy->bydst);
583         else
584                 hlist_add_head(&policy->bydst, chain);
585         xfrm_pol_hold(policy);
586         net->xfrm.policy_count[dir]++;
587         atomic_inc(&flow_cache_genid);
588         if (delpol)
589                 __xfrm_policy_unlink(delpol, dir);
590         policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir);
591         hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
592         policy->curlft.add_time = get_seconds();
593         policy->curlft.use_time = 0;
594         if (!mod_timer(&policy->timer, jiffies + HZ))
595                 xfrm_pol_hold(policy);
596         list_add(&policy->walk.all, &net->xfrm.policy_all);
597         write_unlock_bh(&xfrm_policy_lock);
598
599         if (delpol)
600                 xfrm_policy_kill(delpol);
601         else if (xfrm_bydst_should_resize(net, dir, NULL))
602                 schedule_work(&net->xfrm.policy_hash_work);
603
604         return 0;
605 }
606 EXPORT_SYMBOL(xfrm_policy_insert);
607
608 struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u8 type,
609                                           int dir, struct xfrm_selector *sel,
610                                           struct xfrm_sec_ctx *ctx, int delete,
611                                           int *err)
612 {
613         struct xfrm_policy *pol, *ret;
614         struct hlist_head *chain;
615         struct hlist_node *entry;
616
617         *err = 0;
618         write_lock_bh(&xfrm_policy_lock);
619         chain = policy_hash_bysel(net, sel, sel->family, dir);
620         ret = NULL;
621         hlist_for_each_entry(pol, entry, chain, bydst) {
622                 if (pol->type == type &&
623                     (mark & pol->mark.m) == pol->mark.v &&
624                     !selector_cmp(sel, &pol->selector) &&
625                     xfrm_sec_ctx_match(ctx, pol->security)) {
626                         xfrm_pol_hold(pol);
627                         if (delete) {
628                                 *err = security_xfrm_policy_delete(
629                                                                 pol->security);
630                                 if (*err) {
631                                         write_unlock_bh(&xfrm_policy_lock);
632                                         return pol;
633                                 }
634                                 __xfrm_policy_unlink(pol, dir);
635                         }
636                         ret = pol;
637                         break;
638                 }
639         }
640         write_unlock_bh(&xfrm_policy_lock);
641
642         if (ret && delete)
643                 xfrm_policy_kill(ret);
644         return ret;
645 }
646 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
647
648 struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8 type,
649                                      int dir, u32 id, int delete, int *err)
650 {
651         struct xfrm_policy *pol, *ret;
652         struct hlist_head *chain;
653         struct hlist_node *entry;
654
655         *err = -ENOENT;
656         if (xfrm_policy_id2dir(id) != dir)
657                 return NULL;
658
659         *err = 0;
660         write_lock_bh(&xfrm_policy_lock);
661         chain = net->xfrm.policy_byidx + idx_hash(net, id);
662         ret = NULL;
663         hlist_for_each_entry(pol, entry, chain, byidx) {
664                 if (pol->type == type && pol->index == id &&
665                     (mark & pol->mark.m) == pol->mark.v) {
666                         xfrm_pol_hold(pol);
667                         if (delete) {
668                                 *err = security_xfrm_policy_delete(
669                                                                 pol->security);
670                                 if (*err) {
671                                         write_unlock_bh(&xfrm_policy_lock);
672                                         return pol;
673                                 }
674                                 __xfrm_policy_unlink(pol, dir);
675                         }
676                         ret = pol;
677                         break;
678                 }
679         }
680         write_unlock_bh(&xfrm_policy_lock);
681
682         if (ret && delete)
683                 xfrm_policy_kill(ret);
684         return ret;
685 }
686 EXPORT_SYMBOL(xfrm_policy_byid);
687
688 #ifdef CONFIG_SECURITY_NETWORK_XFRM
689 static inline int
690 xfrm_policy_flush_secctx_check(struct net *net, u8 type, struct xfrm_audit *audit_info)
691 {
692         int dir, err = 0;
693
694         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
695                 struct xfrm_policy *pol;
696                 struct hlist_node *entry;
697                 int i;
698
699                 hlist_for_each_entry(pol, entry,
700                                      &net->xfrm.policy_inexact[dir], bydst) {
701                         if (pol->type != type)
702                                 continue;
703                         err = security_xfrm_policy_delete(pol->security);
704                         if (err) {
705                                 xfrm_audit_policy_delete(pol, 0,
706                                                          audit_info->loginuid,
707                                                          audit_info->sessionid,
708                                                          audit_info->secid);
709                                 return err;
710                         }
711                 }
712                 for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
713                         hlist_for_each_entry(pol, entry,
714                                              net->xfrm.policy_bydst[dir].table + i,
715                                              bydst) {
716                                 if (pol->type != type)
717                                         continue;
718                                 err = security_xfrm_policy_delete(
719                                                                 pol->security);
720                                 if (err) {
721                                         xfrm_audit_policy_delete(pol, 0,
722                                                         audit_info->loginuid,
723                                                         audit_info->sessionid,
724                                                         audit_info->secid);
725                                         return err;
726                                 }
727                         }
728                 }
729         }
730         return err;
731 }
732 #else
733 static inline int
734 xfrm_policy_flush_secctx_check(struct net *net, u8 type, struct xfrm_audit *audit_info)
735 {
736         return 0;
737 }
738 #endif
739
740 int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info)
741 {
742         int dir, err = 0, cnt = 0;
743
744         write_lock_bh(&xfrm_policy_lock);
745
746         err = xfrm_policy_flush_secctx_check(net, type, audit_info);
747         if (err)
748                 goto out;
749
750         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
751                 struct xfrm_policy *pol;
752                 struct hlist_node *entry;
753                 int i;
754
755         again1:
756                 hlist_for_each_entry(pol, entry,
757                                      &net->xfrm.policy_inexact[dir], bydst) {
758                         if (pol->type != type)
759                                 continue;
760                         __xfrm_policy_unlink(pol, dir);
761                         write_unlock_bh(&xfrm_policy_lock);
762                         cnt++;
763
764                         xfrm_audit_policy_delete(pol, 1, audit_info->loginuid,
765                                                  audit_info->sessionid,
766                                                  audit_info->secid);
767
768                         xfrm_policy_kill(pol);
769
770                         write_lock_bh(&xfrm_policy_lock);
771                         goto again1;
772                 }
773
774                 for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
775         again2:
776                         hlist_for_each_entry(pol, entry,
777                                              net->xfrm.policy_bydst[dir].table + i,
778                                              bydst) {
779                                 if (pol->type != type)
780                                         continue;
781                                 __xfrm_policy_unlink(pol, dir);
782                                 write_unlock_bh(&xfrm_policy_lock);
783                                 cnt++;
784
785                                 xfrm_audit_policy_delete(pol, 1,
786                                                          audit_info->loginuid,
787                                                          audit_info->sessionid,
788                                                          audit_info->secid);
789                                 xfrm_policy_kill(pol);
790
791                                 write_lock_bh(&xfrm_policy_lock);
792                                 goto again2;
793                         }
794                 }
795
796         }
797         if (!cnt)
798                 err = -ESRCH;
799 out:
800         write_unlock_bh(&xfrm_policy_lock);
801         return err;
802 }
803 EXPORT_SYMBOL(xfrm_policy_flush);
804
805 int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
806                      int (*func)(struct xfrm_policy *, int, int, void*),
807                      void *data)
808 {
809         struct xfrm_policy *pol;
810         struct xfrm_policy_walk_entry *x;
811         int error = 0;
812
813         if (walk->type >= XFRM_POLICY_TYPE_MAX &&
814             walk->type != XFRM_POLICY_TYPE_ANY)
815                 return -EINVAL;
816
817         if (list_empty(&walk->walk.all) && walk->seq != 0)
818                 return 0;
819
820         write_lock_bh(&xfrm_policy_lock);
821         if (list_empty(&walk->walk.all))
822                 x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
823         else
824                 x = list_entry(&walk->walk.all, struct xfrm_policy_walk_entry, all);
825         list_for_each_entry_from(x, &net->xfrm.policy_all, all) {
826                 if (x->dead)
827                         continue;
828                 pol = container_of(x, struct xfrm_policy, walk);
829                 if (walk->type != XFRM_POLICY_TYPE_ANY &&
830                     walk->type != pol->type)
831                         continue;
832                 error = func(pol, xfrm_policy_id2dir(pol->index),
833                              walk->seq, data);
834                 if (error) {
835                         list_move_tail(&walk->walk.all, &x->all);
836                         goto out;
837                 }
838                 walk->seq++;
839         }
840         if (walk->seq == 0) {
841                 error = -ENOENT;
842                 goto out;
843         }
844         list_del_init(&walk->walk.all);
845 out:
846         write_unlock_bh(&xfrm_policy_lock);
847         return error;
848 }
849 EXPORT_SYMBOL(xfrm_policy_walk);
850
851 void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type)
852 {
853         INIT_LIST_HEAD(&walk->walk.all);
854         walk->walk.dead = 1;
855         walk->type = type;
856         walk->seq = 0;
857 }
858 EXPORT_SYMBOL(xfrm_policy_walk_init);
859
860 void xfrm_policy_walk_done(struct xfrm_policy_walk *walk)
861 {
862         if (list_empty(&walk->walk.all))
863                 return;
864
865         write_lock_bh(&xfrm_policy_lock);
866         list_del(&walk->walk.all);
867         write_unlock_bh(&xfrm_policy_lock);
868 }
869 EXPORT_SYMBOL(xfrm_policy_walk_done);
870
871 /*
872  * Find policy to apply to this flow.
873  *
874  * Returns 0 if policy found, else an -errno.
875  */
876 static int xfrm_policy_match(const struct xfrm_policy *pol,
877                              const struct flowi *fl,
878                              u8 type, u16 family, int dir)
879 {
880         const struct xfrm_selector *sel = &pol->selector;
881         int ret = -ESRCH;
882         bool match;
883
884         if (pol->family != family ||
885             (fl->flowi_mark & pol->mark.m) != pol->mark.v ||
886             pol->type != type)
887                 return ret;
888
889         match = xfrm_selector_match(sel, fl, family);
890         if (match)
891                 ret = security_xfrm_policy_lookup(pol->security, fl->flowi_secid,
892                                                   dir);
893
894         return ret;
895 }
896
897 static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
898                                                      const struct flowi *fl,
899                                                      u16 family, u8 dir)
900 {
901         int err;
902         struct xfrm_policy *pol, *ret;
903         const xfrm_address_t *daddr, *saddr;
904         struct hlist_node *entry;
905         struct hlist_head *chain;
906         u32 priority = ~0U;
907
908         daddr = xfrm_flowi_daddr(fl, family);
909         saddr = xfrm_flowi_saddr(fl, family);
910         if (unlikely(!daddr || !saddr))
911                 return NULL;
912
913         read_lock_bh(&xfrm_policy_lock);
914         chain = policy_hash_direct(net, daddr, saddr, family, dir);
915         ret = NULL;
916         hlist_for_each_entry(pol, entry, chain, bydst) {
917                 err = xfrm_policy_match(pol, fl, type, family, dir);
918                 if (err) {
919                         if (err == -ESRCH)
920                                 continue;
921                         else {
922                                 ret = ERR_PTR(err);
923                                 goto fail;
924                         }
925                 } else {
926                         ret = pol;
927                         priority = ret->priority;
928                         break;
929                 }
930         }
931         chain = &net->xfrm.policy_inexact[dir];
932         hlist_for_each_entry(pol, entry, chain, bydst) {
933                 err = xfrm_policy_match(pol, fl, type, family, dir);
934                 if (err) {
935                         if (err == -ESRCH)
936                                 continue;
937                         else {
938                                 ret = ERR_PTR(err);
939                                 goto fail;
940                         }
941                 } else if (pol->priority < priority) {
942                         ret = pol;
943                         break;
944                 }
945         }
946         if (ret)
947                 xfrm_pol_hold(ret);
948 fail:
949         read_unlock_bh(&xfrm_policy_lock);
950
951         return ret;
952 }
953
954 static struct xfrm_policy *
955 __xfrm_policy_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir)
956 {
957 #ifdef CONFIG_XFRM_SUB_POLICY
958         struct xfrm_policy *pol;
959
960         pol = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_SUB, fl, family, dir);
961         if (pol != NULL)
962                 return pol;
963 #endif
964         return xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, fl, family, dir);
965 }
966
967 static struct flow_cache_object *
968 xfrm_policy_lookup(struct net *net, const struct flowi *fl, u16 family,
969                    u8 dir, struct flow_cache_object *old_obj, void *ctx)
970 {
971         struct xfrm_policy *pol;
972
973         if (old_obj)
974                 xfrm_pol_put(container_of(old_obj, struct xfrm_policy, flo));
975
976         pol = __xfrm_policy_lookup(net, fl, family, dir);
977         if (IS_ERR_OR_NULL(pol))
978                 return ERR_CAST(pol);
979
980         /* Resolver returns two references:
981          * one for cache and one for caller of flow_cache_lookup() */
982         xfrm_pol_hold(pol);
983
984         return &pol->flo;
985 }
986
987 static inline int policy_to_flow_dir(int dir)
988 {
989         if (XFRM_POLICY_IN == FLOW_DIR_IN &&
990             XFRM_POLICY_OUT == FLOW_DIR_OUT &&
991             XFRM_POLICY_FWD == FLOW_DIR_FWD)
992                 return dir;
993         switch (dir) {
994         default:
995         case XFRM_POLICY_IN:
996                 return FLOW_DIR_IN;
997         case XFRM_POLICY_OUT:
998                 return FLOW_DIR_OUT;
999         case XFRM_POLICY_FWD:
1000                 return FLOW_DIR_FWD;
1001         }
1002 }
1003
1004 static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir,
1005                                                  const struct flowi *fl)
1006 {
1007         struct xfrm_policy *pol;
1008
1009         read_lock_bh(&xfrm_policy_lock);
1010         if ((pol = sk->sk_policy[dir]) != NULL) {
1011                 bool match = xfrm_selector_match(&pol->selector, fl,
1012                                                  sk->sk_family);
1013                 int err = 0;
1014
1015                 if (match) {
1016                         if ((sk->sk_mark & pol->mark.m) != pol->mark.v) {
1017                                 pol = NULL;
1018                                 goto out;
1019                         }
1020                         err = security_xfrm_policy_lookup(pol->security,
1021                                                       fl->flowi_secid,
1022                                                       policy_to_flow_dir(dir));
1023                         if (!err)
1024                                 xfrm_pol_hold(pol);
1025                         else if (err == -ESRCH)
1026                                 pol = NULL;
1027                         else
1028                                 pol = ERR_PTR(err);
1029                 } else
1030                         pol = NULL;
1031         }
1032 out:
1033         read_unlock_bh(&xfrm_policy_lock);
1034         return pol;
1035 }
1036
1037 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
1038 {
1039         struct net *net = xp_net(pol);
1040         struct hlist_head *chain = policy_hash_bysel(net, &pol->selector,
1041                                                      pol->family, dir);
1042
1043         list_add(&pol->walk.all, &net->xfrm.policy_all);
1044         hlist_add_head(&pol->bydst, chain);
1045         hlist_add_head(&pol->byidx, net->xfrm.policy_byidx+idx_hash(net, pol->index));
1046         net->xfrm.policy_count[dir]++;
1047         xfrm_pol_hold(pol);
1048
1049         if (xfrm_bydst_should_resize(net, dir, NULL))
1050                 schedule_work(&net->xfrm.policy_hash_work);
1051 }
1052
1053 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
1054                                                 int dir)
1055 {
1056         struct net *net = xp_net(pol);
1057
1058         if (hlist_unhashed(&pol->bydst))
1059                 return NULL;
1060
1061         hlist_del(&pol->bydst);
1062         hlist_del(&pol->byidx);
1063         list_del(&pol->walk.all);
1064         net->xfrm.policy_count[dir]--;
1065
1066         return pol;
1067 }
1068
1069 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
1070 {
1071         write_lock_bh(&xfrm_policy_lock);
1072         pol = __xfrm_policy_unlink(pol, dir);
1073         write_unlock_bh(&xfrm_policy_lock);
1074         if (pol) {
1075                 xfrm_policy_kill(pol);
1076                 return 0;
1077         }
1078         return -ENOENT;
1079 }
1080 EXPORT_SYMBOL(xfrm_policy_delete);
1081
1082 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
1083 {
1084         struct net *net = xp_net(pol);
1085         struct xfrm_policy *old_pol;
1086
1087 #ifdef CONFIG_XFRM_SUB_POLICY
1088         if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
1089                 return -EINVAL;
1090 #endif
1091
1092         write_lock_bh(&xfrm_policy_lock);
1093         old_pol = sk->sk_policy[dir];
1094         sk->sk_policy[dir] = pol;
1095         if (pol) {
1096                 pol->curlft.add_time = get_seconds();
1097                 pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir);
1098                 __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
1099         }
1100         if (old_pol)
1101                 /* Unlinking succeeds always. This is the only function
1102                  * allowed to delete or replace socket policy.
1103                  */
1104                 __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
1105         write_unlock_bh(&xfrm_policy_lock);
1106
1107         if (old_pol) {
1108                 xfrm_policy_kill(old_pol);
1109         }
1110         return 0;
1111 }
1112
1113 static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
1114 {
1115         struct xfrm_policy *newp = xfrm_policy_alloc(xp_net(old), GFP_ATOMIC);
1116
1117         if (newp) {
1118                 newp->selector = old->selector;
1119                 if (security_xfrm_policy_clone(old->security,
1120                                                &newp->security)) {
1121                         kfree(newp);
1122                         return NULL;  /* ENOMEM */
1123                 }
1124                 newp->lft = old->lft;
1125                 newp->curlft = old->curlft;
1126                 newp->mark = old->mark;
1127                 newp->action = old->action;
1128                 newp->flags = old->flags;
1129                 newp->xfrm_nr = old->xfrm_nr;
1130                 newp->index = old->index;
1131                 newp->type = old->type;
1132                 memcpy(newp->xfrm_vec, old->xfrm_vec,
1133                        newp->xfrm_nr*sizeof(struct xfrm_tmpl));
1134                 write_lock_bh(&xfrm_policy_lock);
1135                 __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir);
1136                 write_unlock_bh(&xfrm_policy_lock);
1137                 xfrm_pol_put(newp);
1138         }
1139         return newp;
1140 }
1141
1142 int __xfrm_sk_clone_policy(struct sock *sk)
1143 {
1144         struct xfrm_policy *p0 = sk->sk_policy[0],
1145                            *p1 = sk->sk_policy[1];
1146
1147         sk->sk_policy[0] = sk->sk_policy[1] = NULL;
1148         if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL)
1149                 return -ENOMEM;
1150         if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL)
1151                 return -ENOMEM;
1152         return 0;
1153 }
1154
1155 static int
1156 xfrm_get_saddr(struct net *net, xfrm_address_t *local, xfrm_address_t *remote,
1157                unsigned short family)
1158 {
1159         int err;
1160         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1161
1162         if (unlikely(afinfo == NULL))
1163                 return -EINVAL;
1164         err = afinfo->get_saddr(net, local, remote);
1165         xfrm_policy_put_afinfo(afinfo);
1166         return err;
1167 }
1168
1169 /* Resolve list of templates for the flow, given policy. */
1170
1171 static int
1172 xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
1173                       struct xfrm_state **xfrm, unsigned short family)
1174 {
1175         struct net *net = xp_net(policy);
1176         int nx;
1177         int i, error;
1178         xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
1179         xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
1180         xfrm_address_t tmp;
1181
1182         for (nx=0, i = 0; i < policy->xfrm_nr; i++) {
1183                 struct xfrm_state *x;
1184                 xfrm_address_t *remote = daddr;
1185                 xfrm_address_t *local  = saddr;
1186                 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
1187
1188                 if (tmpl->mode == XFRM_MODE_TUNNEL ||
1189                     tmpl->mode == XFRM_MODE_BEET) {
1190                         remote = &tmpl->id.daddr;
1191                         local = &tmpl->saddr;
1192                         if (xfrm_addr_any(local, tmpl->encap_family)) {
1193                                 error = xfrm_get_saddr(net, &tmp, remote, tmpl->encap_family);
1194                                 if (error)
1195                                         goto fail;
1196                                 local = &tmp;
1197                         }
1198                 }
1199
1200                 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
1201
1202                 if (x && x->km.state == XFRM_STATE_VALID) {
1203                         xfrm[nx++] = x;
1204                         daddr = remote;
1205                         saddr = local;
1206                         continue;
1207                 }
1208                 if (x) {
1209                         error = (x->km.state == XFRM_STATE_ERROR ?
1210                                  -EINVAL : -EAGAIN);
1211                         xfrm_state_put(x);
1212                 }
1213                 else if (error == -ESRCH)
1214                         error = -EAGAIN;
1215
1216                 if (!tmpl->optional)
1217                         goto fail;
1218         }
1219         return nx;
1220
1221 fail:
1222         for (nx--; nx>=0; nx--)
1223                 xfrm_state_put(xfrm[nx]);
1224         return error;
1225 }
1226
1227 static int
1228 xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, const struct flowi *fl,
1229                   struct xfrm_state **xfrm, unsigned short family)
1230 {
1231         struct xfrm_state *tp[XFRM_MAX_DEPTH];
1232         struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
1233         int cnx = 0;
1234         int error;
1235         int ret;
1236         int i;
1237
1238         for (i = 0; i < npols; i++) {
1239                 if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
1240                         error = -ENOBUFS;
1241                         goto fail;
1242                 }
1243
1244                 ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
1245                 if (ret < 0) {
1246                         error = ret;
1247                         goto fail;
1248                 } else
1249                         cnx += ret;
1250         }
1251
1252         /* found states are sorted for outbound processing */
1253         if (npols > 1)
1254                 xfrm_state_sort(xfrm, tpp, cnx, family);
1255
1256         return cnx;
1257
1258  fail:
1259         for (cnx--; cnx>=0; cnx--)
1260                 xfrm_state_put(tpp[cnx]);
1261         return error;
1262
1263 }
1264
1265 /* Check that the bundle accepts the flow and its components are
1266  * still valid.
1267  */
1268
1269 static inline int xfrm_get_tos(const struct flowi *fl, int family)
1270 {
1271         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1272         int tos;
1273
1274         if (!afinfo)
1275                 return -EINVAL;
1276
1277         tos = afinfo->get_tos(fl);
1278
1279         xfrm_policy_put_afinfo(afinfo);
1280
1281         return tos;
1282 }
1283
1284 static struct flow_cache_object *xfrm_bundle_flo_get(struct flow_cache_object *flo)
1285 {
1286         struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1287         struct dst_entry *dst = &xdst->u.dst;
1288
1289         if (xdst->route == NULL) {
1290                 /* Dummy bundle - if it has xfrms we were not
1291                  * able to build bundle as template resolution failed.
1292                  * It means we need to try again resolving. */
1293                 if (xdst->num_xfrms > 0)
1294                         return NULL;
1295         } else {
1296                 /* Real bundle */
1297                 if (stale_bundle(dst))
1298                         return NULL;
1299         }
1300
1301         dst_hold(dst);
1302         return flo;
1303 }
1304
1305 static int xfrm_bundle_flo_check(struct flow_cache_object *flo)
1306 {
1307         struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1308         struct dst_entry *dst = &xdst->u.dst;
1309
1310         if (!xdst->route)
1311                 return 0;
1312         if (stale_bundle(dst))
1313                 return 0;
1314
1315         return 1;
1316 }
1317
1318 static void xfrm_bundle_flo_delete(struct flow_cache_object *flo)
1319 {
1320         struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1321         struct dst_entry *dst = &xdst->u.dst;
1322
1323         dst_free(dst);
1324 }
1325
1326 static const struct flow_cache_ops xfrm_bundle_fc_ops = {
1327         .get = xfrm_bundle_flo_get,
1328         .check = xfrm_bundle_flo_check,
1329         .delete = xfrm_bundle_flo_delete,
1330 };
1331
1332 static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
1333 {
1334         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1335         struct dst_ops *dst_ops;
1336         struct xfrm_dst *xdst;
1337
1338         if (!afinfo)
1339                 return ERR_PTR(-EINVAL);
1340
1341         switch (family) {
1342         case AF_INET:
1343                 dst_ops = &net->xfrm.xfrm4_dst_ops;
1344                 break;
1345 #if IS_ENABLED(CONFIG_IPV6)
1346         case AF_INET6:
1347                 dst_ops = &net->xfrm.xfrm6_dst_ops;
1348                 break;
1349 #endif
1350         default:
1351                 BUG();
1352         }
1353         xdst = dst_alloc(dst_ops, NULL, 0, 0, 0);
1354
1355         if (likely(xdst)) {
1356                 memset(&xdst->u.rt6.rt6i_table, 0,
1357                         sizeof(*xdst) - sizeof(struct dst_entry));
1358                 xdst->flo.ops = &xfrm_bundle_fc_ops;
1359         } else
1360                 xdst = ERR_PTR(-ENOBUFS);
1361
1362         xfrm_policy_put_afinfo(afinfo);
1363
1364         return xdst;
1365 }
1366
1367 static inline int xfrm_init_path(struct xfrm_dst *path, struct dst_entry *dst,
1368                                  int nfheader_len)
1369 {
1370         struct xfrm_policy_afinfo *afinfo =
1371                 xfrm_policy_get_afinfo(dst->ops->family);
1372         int err;
1373
1374         if (!afinfo)
1375                 return -EINVAL;
1376
1377         err = afinfo->init_path(path, dst, nfheader_len);
1378
1379         xfrm_policy_put_afinfo(afinfo);
1380
1381         return err;
1382 }
1383
1384 static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
1385                                 const struct flowi *fl)
1386 {
1387         struct xfrm_policy_afinfo *afinfo =
1388                 xfrm_policy_get_afinfo(xdst->u.dst.ops->family);
1389         int err;
1390
1391         if (!afinfo)
1392                 return -EINVAL;
1393
1394         err = afinfo->fill_dst(xdst, dev, fl);
1395
1396         xfrm_policy_put_afinfo(afinfo);
1397
1398         return err;
1399 }
1400
1401
1402 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
1403  * all the metrics... Shortly, bundle a bundle.
1404  */
1405
1406 static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
1407                                             struct xfrm_state **xfrm, int nx,
1408                                             const struct flowi *fl,
1409                                             struct dst_entry *dst)
1410 {
1411         struct net *net = xp_net(policy);
1412         unsigned long now = jiffies;
1413         struct net_device *dev;
1414         struct xfrm_mode *inner_mode;
1415         struct dst_entry *dst_prev = NULL;
1416         struct dst_entry *dst0 = NULL;
1417         int i = 0;
1418         int err;
1419         int header_len = 0;
1420         int nfheader_len = 0;
1421         int trailer_len = 0;
1422         int tos;
1423         int family = policy->selector.family;
1424         xfrm_address_t saddr, daddr;
1425
1426         xfrm_flowi_addr_get(fl, &saddr, &daddr, family);
1427
1428         tos = xfrm_get_tos(fl, family);
1429         err = tos;
1430         if (tos < 0)
1431                 goto put_states;
1432
1433         dst_hold(dst);
1434
1435         for (; i < nx; i++) {
1436                 struct xfrm_dst *xdst = xfrm_alloc_dst(net, family);
1437                 struct dst_entry *dst1 = &xdst->u.dst;
1438
1439                 err = PTR_ERR(xdst);
1440                 if (IS_ERR(xdst)) {
1441                         dst_release(dst);
1442                         goto put_states;
1443                 }
1444
1445                 if (xfrm[i]->sel.family == AF_UNSPEC) {
1446                         inner_mode = xfrm_ip2inner_mode(xfrm[i],
1447                                                         xfrm_af2proto(family));
1448                         if (!inner_mode) {
1449                                 err = -EAFNOSUPPORT;
1450                                 dst_release(dst);
1451                                 goto put_states;
1452                         }
1453                 } else
1454                         inner_mode = xfrm[i]->inner_mode;
1455
1456                 if (!dst_prev)
1457                         dst0 = dst1;
1458                 else {
1459                         dst_prev->child = dst_clone(dst1);
1460                         dst1->flags |= DST_NOHASH;
1461                 }
1462
1463                 xdst->route = dst;
1464                 dst_copy_metrics(dst1, dst);
1465
1466                 if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
1467                         family = xfrm[i]->props.family;
1468                         dst = xfrm_dst_lookup(xfrm[i], tos, &saddr, &daddr,
1469                                               family);
1470                         err = PTR_ERR(dst);
1471                         if (IS_ERR(dst))
1472                                 goto put_states;
1473                 } else
1474                         dst_hold(dst);
1475
1476                 dst1->xfrm = xfrm[i];
1477                 xdst->xfrm_genid = xfrm[i]->genid;
1478
1479                 dst1->obsolete = -1;
1480                 dst1->flags |= DST_HOST;
1481                 dst1->lastuse = now;
1482
1483                 dst1->input = dst_discard;
1484                 dst1->output = inner_mode->afinfo->output;
1485
1486                 dst1->next = dst_prev;
1487                 dst_prev = dst1;
1488
1489                 header_len += xfrm[i]->props.header_len;
1490                 if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
1491                         nfheader_len += xfrm[i]->props.header_len;
1492                 trailer_len += xfrm[i]->props.trailer_len;
1493         }
1494
1495         dst_prev->child = dst;
1496         dst0->path = dst;
1497
1498         err = -ENODEV;
1499         dev = dst->dev;
1500         if (!dev)
1501                 goto free_dst;
1502
1503         /* Copy neighbour for reachability confirmation */
1504         dst_set_neighbour(dst0, neigh_clone(dst_get_neighbour_noref(dst)));
1505
1506         xfrm_init_path((struct xfrm_dst *)dst0, dst, nfheader_len);
1507         xfrm_init_pmtu(dst_prev);
1508
1509         for (dst_prev = dst0; dst_prev != dst; dst_prev = dst_prev->child) {
1510                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst_prev;
1511
1512                 err = xfrm_fill_dst(xdst, dev, fl);
1513                 if (err)
1514                         goto free_dst;
1515
1516                 dst_prev->header_len = header_len;
1517                 dst_prev->trailer_len = trailer_len;
1518                 header_len -= xdst->u.dst.xfrm->props.header_len;
1519                 trailer_len -= xdst->u.dst.xfrm->props.trailer_len;
1520         }
1521
1522 out:
1523         return dst0;
1524
1525 put_states:
1526         for (; i < nx; i++)
1527                 xfrm_state_put(xfrm[i]);
1528 free_dst:
1529         if (dst0)
1530                 dst_free(dst0);
1531         dst0 = ERR_PTR(err);
1532         goto out;
1533 }
1534
1535 static int inline
1536 xfrm_dst_alloc_copy(void **target, const void *src, int size)
1537 {
1538         if (!*target) {
1539                 *target = kmalloc(size, GFP_ATOMIC);
1540                 if (!*target)
1541                         return -ENOMEM;
1542         }
1543         memcpy(*target, src, size);
1544         return 0;
1545 }
1546
1547 static int inline
1548 xfrm_dst_update_parent(struct dst_entry *dst, const struct xfrm_selector *sel)
1549 {
1550 #ifdef CONFIG_XFRM_SUB_POLICY
1551         struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1552         return xfrm_dst_alloc_copy((void **)&(xdst->partner),
1553                                    sel, sizeof(*sel));
1554 #else
1555         return 0;
1556 #endif
1557 }
1558
1559 static int inline
1560 xfrm_dst_update_origin(struct dst_entry *dst, const struct flowi *fl)
1561 {
1562 #ifdef CONFIG_XFRM_SUB_POLICY
1563         struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1564         return xfrm_dst_alloc_copy((void **)&(xdst->origin), fl, sizeof(*fl));
1565 #else
1566         return 0;
1567 #endif
1568 }
1569
1570 static int xfrm_expand_policies(const struct flowi *fl, u16 family,
1571                                 struct xfrm_policy **pols,
1572                                 int *num_pols, int *num_xfrms)
1573 {
1574         int i;
1575
1576         if (*num_pols == 0 || !pols[0]) {
1577                 *num_pols = 0;
1578                 *num_xfrms = 0;
1579                 return 0;
1580         }
1581         if (IS_ERR(pols[0]))
1582                 return PTR_ERR(pols[0]);
1583
1584         *num_xfrms = pols[0]->xfrm_nr;
1585
1586 #ifdef CONFIG_XFRM_SUB_POLICY
1587         if (pols[0] && pols[0]->action == XFRM_POLICY_ALLOW &&
1588             pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1589                 pols[1] = xfrm_policy_lookup_bytype(xp_net(pols[0]),
1590                                                     XFRM_POLICY_TYPE_MAIN,
1591                                                     fl, family,
1592                                                     XFRM_POLICY_OUT);
1593                 if (pols[1]) {
1594                         if (IS_ERR(pols[1])) {
1595                                 xfrm_pols_put(pols, *num_pols);
1596                                 return PTR_ERR(pols[1]);
1597                         }
1598                         (*num_pols) ++;
1599                         (*num_xfrms) += pols[1]->xfrm_nr;
1600                 }
1601         }
1602 #endif
1603         for (i = 0; i < *num_pols; i++) {
1604                 if (pols[i]->action != XFRM_POLICY_ALLOW) {
1605                         *num_xfrms = -1;
1606                         break;
1607                 }
1608         }
1609
1610         return 0;
1611
1612 }
1613
1614 static struct xfrm_dst *
1615 xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
1616                                const struct flowi *fl, u16 family,
1617                                struct dst_entry *dst_orig)
1618 {
1619         struct net *net = xp_net(pols[0]);
1620         struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
1621         struct dst_entry *dst;
1622         struct xfrm_dst *xdst;
1623         int err;
1624
1625         /* Try to instantiate a bundle */
1626         err = xfrm_tmpl_resolve(pols, num_pols, fl, xfrm, family);
1627         if (err <= 0) {
1628                 if (err != 0 && err != -EAGAIN)
1629                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
1630                 return ERR_PTR(err);
1631         }
1632
1633         dst = xfrm_bundle_create(pols[0], xfrm, err, fl, dst_orig);
1634         if (IS_ERR(dst)) {
1635                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR);
1636                 return ERR_CAST(dst);
1637         }
1638
1639         xdst = (struct xfrm_dst *)dst;
1640         xdst->num_xfrms = err;
1641         if (num_pols > 1)
1642                 err = xfrm_dst_update_parent(dst, &pols[1]->selector);
1643         else
1644                 err = xfrm_dst_update_origin(dst, fl);
1645         if (unlikely(err)) {
1646                 dst_free(dst);
1647                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLECHECKERROR);
1648                 return ERR_PTR(err);
1649         }
1650
1651         xdst->num_pols = num_pols;
1652         memcpy(xdst->pols, pols, sizeof(struct xfrm_policy*) * num_pols);
1653         xdst->policy_genid = atomic_read(&pols[0]->genid);
1654
1655         return xdst;
1656 }
1657
1658 static struct flow_cache_object *
1659 xfrm_bundle_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir,
1660                    struct flow_cache_object *oldflo, void *ctx)
1661 {
1662         struct dst_entry *dst_orig = (struct dst_entry *)ctx;
1663         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1664         struct xfrm_dst *xdst, *new_xdst;
1665         int num_pols = 0, num_xfrms = 0, i, err, pol_dead;
1666
1667         /* Check if the policies from old bundle are usable */
1668         xdst = NULL;
1669         if (oldflo) {
1670                 xdst = container_of(oldflo, struct xfrm_dst, flo);
1671                 num_pols = xdst->num_pols;
1672                 num_xfrms = xdst->num_xfrms;
1673                 pol_dead = 0;
1674                 for (i = 0; i < num_pols; i++) {
1675                         pols[i] = xdst->pols[i];
1676                         pol_dead |= pols[i]->walk.dead;
1677                 }
1678                 if (pol_dead) {
1679                         dst_free(&xdst->u.dst);
1680                         xdst = NULL;
1681                         num_pols = 0;
1682                         num_xfrms = 0;
1683                         oldflo = NULL;
1684                 }
1685         }
1686
1687         /* Resolve policies to use if we couldn't get them from
1688          * previous cache entry */
1689         if (xdst == NULL) {
1690                 num_pols = 1;
1691                 pols[0] = __xfrm_policy_lookup(net, fl, family, dir);
1692                 err = xfrm_expand_policies(fl, family, pols,
1693                                            &num_pols, &num_xfrms);
1694                 if (err < 0)
1695                         goto inc_error;
1696                 if (num_pols == 0)
1697                         return NULL;
1698                 if (num_xfrms <= 0)
1699                         goto make_dummy_bundle;
1700         }
1701
1702         new_xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family, dst_orig);
1703         if (IS_ERR(new_xdst)) {
1704                 err = PTR_ERR(new_xdst);
1705                 if (err != -EAGAIN)
1706                         goto error;
1707                 if (oldflo == NULL)
1708                         goto make_dummy_bundle;
1709                 dst_hold(&xdst->u.dst);
1710                 return oldflo;
1711         } else if (new_xdst == NULL) {
1712                 num_xfrms = 0;
1713                 if (oldflo == NULL)
1714                         goto make_dummy_bundle;
1715                 xdst->num_xfrms = 0;
1716                 dst_hold(&xdst->u.dst);
1717                 return oldflo;
1718         }
1719
1720         /* Kill the previous bundle */
1721         if (xdst) {
1722                 /* The policies were stolen for newly generated bundle */
1723                 xdst->num_pols = 0;
1724                 dst_free(&xdst->u.dst);
1725         }
1726
1727         /* Flow cache does not have reference, it dst_free()'s,
1728          * but we do need to return one reference for original caller */
1729         dst_hold(&new_xdst->u.dst);
1730         return &new_xdst->flo;
1731
1732 make_dummy_bundle:
1733         /* We found policies, but there's no bundles to instantiate:
1734          * either because the policy blocks, has no transformations or
1735          * we could not build template (no xfrm_states).*/
1736         xdst = xfrm_alloc_dst(net, family);
1737         if (IS_ERR(xdst)) {
1738                 xfrm_pols_put(pols, num_pols);
1739                 return ERR_CAST(xdst);
1740         }
1741         xdst->num_pols = num_pols;
1742         xdst->num_xfrms = num_xfrms;
1743         memcpy(xdst->pols, pols, sizeof(struct xfrm_policy*) * num_pols);
1744
1745         dst_hold(&xdst->u.dst);
1746         return &xdst->flo;
1747
1748 inc_error:
1749         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
1750 error:
1751         if (xdst != NULL)
1752                 dst_free(&xdst->u.dst);
1753         else
1754                 xfrm_pols_put(pols, num_pols);
1755         return ERR_PTR(err);
1756 }
1757
1758 static struct dst_entry *make_blackhole(struct net *net, u16 family,
1759                                         struct dst_entry *dst_orig)
1760 {
1761         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1762         struct dst_entry *ret;
1763
1764         if (!afinfo) {
1765                 dst_release(dst_orig);
1766                 ret = ERR_PTR(-EINVAL);
1767         } else {
1768                 ret = afinfo->blackhole_route(net, dst_orig);
1769         }
1770         xfrm_policy_put_afinfo(afinfo);
1771
1772         return ret;
1773 }
1774
1775 /* Main function: finds/creates a bundle for given flow.
1776  *
1777  * At the moment we eat a raw IP route. Mostly to speed up lookups
1778  * on interfaces with disabled IPsec.
1779  */
1780 struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
1781                               const struct flowi *fl,
1782                               struct sock *sk, int flags)
1783 {
1784         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1785         struct flow_cache_object *flo;
1786         struct xfrm_dst *xdst;
1787         struct dst_entry *dst, *route;
1788         u16 family = dst_orig->ops->family;
1789         u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
1790         int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
1791
1792 restart:
1793         dst = NULL;
1794         xdst = NULL;
1795         route = NULL;
1796
1797         if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
1798                 num_pols = 1;
1799                 pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
1800                 err = xfrm_expand_policies(fl, family, pols,
1801                                            &num_pols, &num_xfrms);
1802                 if (err < 0)
1803                         goto dropdst;
1804
1805                 if (num_pols) {
1806                         if (num_xfrms <= 0) {
1807                                 drop_pols = num_pols;
1808                                 goto no_transform;
1809                         }
1810
1811                         xdst = xfrm_resolve_and_create_bundle(
1812                                         pols, num_pols, fl,
1813                                         family, dst_orig);
1814                         if (IS_ERR(xdst)) {
1815                                 xfrm_pols_put(pols, num_pols);
1816                                 err = PTR_ERR(xdst);
1817                                 goto dropdst;
1818                         } else if (xdst == NULL) {
1819                                 num_xfrms = 0;
1820                                 drop_pols = num_pols;
1821                                 goto no_transform;
1822                         }
1823
1824                         dst_hold(&xdst->u.dst);
1825
1826                         spin_lock_bh(&xfrm_policy_sk_bundle_lock);
1827                         xdst->u.dst.next = xfrm_policy_sk_bundles;
1828                         xfrm_policy_sk_bundles = &xdst->u.dst;
1829                         spin_unlock_bh(&xfrm_policy_sk_bundle_lock);
1830
1831                         route = xdst->route;
1832                 }
1833         }
1834
1835         if (xdst == NULL) {
1836                 /* To accelerate a bit...  */
1837                 if ((dst_orig->flags & DST_NOXFRM) ||
1838                     !net->xfrm.policy_count[XFRM_POLICY_OUT])
1839                         goto nopol;
1840
1841                 flo = flow_cache_lookup(net, fl, family, dir,
1842                                         xfrm_bundle_lookup, dst_orig);
1843                 if (flo == NULL)
1844                         goto nopol;
1845                 if (IS_ERR(flo)) {
1846                         err = PTR_ERR(flo);
1847                         goto dropdst;
1848                 }
1849                 xdst = container_of(flo, struct xfrm_dst, flo);
1850
1851                 num_pols = xdst->num_pols;
1852                 num_xfrms = xdst->num_xfrms;
1853                 memcpy(pols, xdst->pols, sizeof(struct xfrm_policy*) * num_pols);
1854                 route = xdst->route;
1855         }
1856
1857         dst = &xdst->u.dst;
1858         if (route == NULL && num_xfrms > 0) {
1859                 /* The only case when xfrm_bundle_lookup() returns a
1860                  * bundle with null route, is when the template could
1861                  * not be resolved. It means policies are there, but
1862                  * bundle could not be created, since we don't yet
1863                  * have the xfrm_state's. We need to wait for KM to
1864                  * negotiate new SA's or bail out with error.*/
1865                 if (net->xfrm.sysctl_larval_drop) {
1866                         /* EREMOTE tells the caller to generate
1867                          * a one-shot blackhole route. */
1868                         dst_release(dst);
1869                         xfrm_pols_put(pols, drop_pols);
1870                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
1871
1872                         return make_blackhole(net, family, dst_orig);
1873                 }
1874                 if (fl->flowi_flags & FLOWI_FLAG_CAN_SLEEP) {
1875                         DECLARE_WAITQUEUE(wait, current);
1876
1877                         add_wait_queue(&net->xfrm.km_waitq, &wait);
1878                         set_current_state(TASK_INTERRUPTIBLE);
1879                         schedule();
1880                         set_current_state(TASK_RUNNING);
1881                         remove_wait_queue(&net->xfrm.km_waitq, &wait);
1882
1883                         if (!signal_pending(current)) {
1884                                 dst_release(dst);
1885                                 goto restart;
1886                         }
1887
1888                         err = -ERESTART;
1889                 } else
1890                         err = -EAGAIN;
1891
1892                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
1893                 goto error;
1894         }
1895
1896 no_transform:
1897         if (num_pols == 0)
1898                 goto nopol;
1899
1900         if ((flags & XFRM_LOOKUP_ICMP) &&
1901             !(pols[0]->flags & XFRM_POLICY_ICMP)) {
1902                 err = -ENOENT;
1903                 goto error;
1904         }
1905
1906         for (i = 0; i < num_pols; i++)
1907                 pols[i]->curlft.use_time = get_seconds();
1908
1909         if (num_xfrms < 0) {
1910                 /* Prohibit the flow */
1911                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLBLOCK);
1912                 err = -EPERM;
1913                 goto error;
1914         } else if (num_xfrms > 0) {
1915                 /* Flow transformed */
1916                 dst_release(dst_orig);
1917         } else {
1918                 /* Flow passes untransformed */
1919                 dst_release(dst);
1920                 dst = dst_orig;
1921         }
1922 ok:
1923         xfrm_pols_put(pols, drop_pols);
1924         if (dst && dst->xfrm &&
1925             dst->xfrm->props.mode == XFRM_MODE_TUNNEL)
1926                 dst->flags |= DST_XFRM_TUNNEL;
1927         return dst;
1928
1929 nopol:
1930         if (!(flags & XFRM_LOOKUP_ICMP)) {
1931                 dst = dst_orig;
1932                 goto ok;
1933         }
1934         err = -ENOENT;
1935 error:
1936         dst_release(dst);
1937 dropdst:
1938         dst_release(dst_orig);
1939         xfrm_pols_put(pols, drop_pols);
1940         return ERR_PTR(err);
1941 }
1942 EXPORT_SYMBOL(xfrm_lookup);
1943
1944 static inline int
1945 xfrm_secpath_reject(int idx, struct sk_buff *skb, const struct flowi *fl)
1946 {
1947         struct xfrm_state *x;
1948
1949         if (!skb->sp || idx < 0 || idx >= skb->sp->len)
1950                 return 0;
1951         x = skb->sp->xvec[idx];
1952         if (!x->type->reject)
1953                 return 0;
1954         return x->type->reject(x, skb, fl);
1955 }
1956
1957 /* When skb is transformed back to its "native" form, we have to
1958  * check policy restrictions. At the moment we make this in maximally
1959  * stupid way. Shame on me. :-) Of course, connected sockets must
1960  * have policy cached at them.
1961  */
1962
1963 static inline int
1964 xfrm_state_ok(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x,
1965               unsigned short family)
1966 {
1967         if (xfrm_state_kern(x))
1968                 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
1969         return  x->id.proto == tmpl->id.proto &&
1970                 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
1971                 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
1972                 x->props.mode == tmpl->mode &&
1973                 (tmpl->allalgs || (tmpl->aalgos & (1<<x->props.aalgo)) ||
1974                  !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
1975                 !(x->props.mode != XFRM_MODE_TRANSPORT &&
1976                   xfrm_state_addr_cmp(tmpl, x, family));
1977 }
1978
1979 /*
1980  * 0 or more than 0 is returned when validation is succeeded (either bypass
1981  * because of optional transport mode, or next index of the mathced secpath
1982  * state with the template.
1983  * -1 is returned when no matching template is found.
1984  * Otherwise "-2 - errored_index" is returned.
1985  */
1986 static inline int
1987 xfrm_policy_ok(const struct xfrm_tmpl *tmpl, const struct sec_path *sp, int start,
1988                unsigned short family)
1989 {
1990         int idx = start;
1991
1992         if (tmpl->optional) {
1993                 if (tmpl->mode == XFRM_MODE_TRANSPORT)
1994                         return start;
1995         } else
1996                 start = -1;
1997         for (; idx < sp->len; idx++) {
1998                 if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
1999                         return ++idx;
2000                 if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
2001                         if (start == -1)
2002                                 start = -2-idx;
2003                         break;
2004                 }
2005         }
2006         return start;
2007 }
2008
2009 int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
2010                           unsigned int family, int reverse)
2011 {
2012         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2013         int err;
2014
2015         if (unlikely(afinfo == NULL))
2016                 return -EAFNOSUPPORT;
2017
2018         afinfo->decode_session(skb, fl, reverse);
2019         err = security_xfrm_decode_session(skb, &fl->flowi_secid);
2020         xfrm_policy_put_afinfo(afinfo);
2021         return err;
2022 }
2023 EXPORT_SYMBOL(__xfrm_decode_session);
2024
2025 static inline int secpath_has_nontransport(const struct sec_path *sp, int k, int *idxp)
2026 {
2027         for (; k < sp->len; k++) {
2028                 if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
2029                         *idxp = k;
2030                         return 1;
2031                 }
2032         }
2033
2034         return 0;
2035 }
2036
2037 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
2038                         unsigned short family)
2039 {
2040         struct net *net = dev_net(skb->dev);
2041         struct xfrm_policy *pol;
2042         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2043         int npols = 0;
2044         int xfrm_nr;
2045         int pi;
2046         int reverse;
2047         struct flowi fl;
2048         u8 fl_dir;
2049         int xerr_idx = -1;
2050
2051         reverse = dir & ~XFRM_POLICY_MASK;
2052         dir &= XFRM_POLICY_MASK;
2053         fl_dir = policy_to_flow_dir(dir);
2054
2055         if (__xfrm_decode_session(skb, &fl, family, reverse) < 0) {
2056                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
2057                 return 0;
2058         }
2059
2060         nf_nat_decode_session(skb, &fl, family);
2061
2062         /* First, check used SA against their selectors. */
2063         if (skb->sp) {
2064                 int i;
2065
2066                 for (i=skb->sp->len-1; i>=0; i--) {
2067                         struct xfrm_state *x = skb->sp->xvec[i];
2068                         if (!xfrm_selector_match(&x->sel, &fl, family)) {
2069                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
2070                                 return 0;
2071                         }
2072                 }
2073         }
2074
2075         pol = NULL;
2076         if (sk && sk->sk_policy[dir]) {
2077                 pol = xfrm_sk_policy_lookup(sk, dir, &fl);
2078                 if (IS_ERR(pol)) {
2079                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2080                         return 0;
2081                 }
2082         }
2083
2084         if (!pol) {
2085                 struct flow_cache_object *flo;
2086
2087                 flo = flow_cache_lookup(net, &fl, family, fl_dir,
2088                                         xfrm_policy_lookup, NULL);
2089                 if (IS_ERR_OR_NULL(flo))
2090                         pol = ERR_CAST(flo);
2091                 else
2092                         pol = container_of(flo, struct xfrm_policy, flo);
2093         }
2094
2095         if (IS_ERR(pol)) {
2096                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2097                 return 0;
2098         }
2099
2100         if (!pol) {
2101                 if (skb->sp && secpath_has_nontransport(skb->sp, 0, &xerr_idx)) {
2102                         xfrm_secpath_reject(xerr_idx, skb, &fl);
2103                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
2104                         return 0;
2105                 }
2106                 return 1;
2107         }
2108
2109         pol->curlft.use_time = get_seconds();
2110
2111         pols[0] = pol;
2112         npols ++;
2113 #ifdef CONFIG_XFRM_SUB_POLICY
2114         if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
2115                 pols[1] = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN,
2116                                                     &fl, family,
2117                                                     XFRM_POLICY_IN);
2118                 if (pols[1]) {
2119                         if (IS_ERR(pols[1])) {
2120                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2121                                 return 0;
2122                         }
2123                         pols[1]->curlft.use_time = get_seconds();
2124                         npols ++;
2125                 }
2126         }
2127 #endif
2128
2129         if (pol->action == XFRM_POLICY_ALLOW) {
2130                 struct sec_path *sp;
2131                 static struct sec_path dummy;
2132                 struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
2133                 struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
2134                 struct xfrm_tmpl **tpp = tp;
2135                 int ti = 0;
2136                 int i, k;
2137
2138                 if ((sp = skb->sp) == NULL)
2139                         sp = &dummy;
2140
2141                 for (pi = 0; pi < npols; pi++) {
2142                         if (pols[pi] != pol &&
2143                             pols[pi]->action != XFRM_POLICY_ALLOW) {
2144                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2145                                 goto reject;
2146                         }
2147                         if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH) {
2148                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
2149                                 goto reject_error;
2150                         }
2151                         for (i = 0; i < pols[pi]->xfrm_nr; i++)
2152                                 tpp[ti++] = &pols[pi]->xfrm_vec[i];
2153                 }
2154                 xfrm_nr = ti;
2155                 if (npols > 1) {
2156                         xfrm_tmpl_sort(stp, tpp, xfrm_nr, family);
2157                         tpp = stp;
2158                 }
2159
2160                 /* For each tunnel xfrm, find the first matching tmpl.
2161                  * For each tmpl before that, find corresponding xfrm.
2162                  * Order is _important_. Later we will implement
2163                  * some barriers, but at the moment barriers
2164                  * are implied between each two transformations.
2165                  */
2166                 for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
2167                         k = xfrm_policy_ok(tpp[i], sp, k, family);
2168                         if (k < 0) {
2169                                 if (k < -1)
2170                                         /* "-2 - errored_index" returned */
2171                                         xerr_idx = -(2+k);
2172                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2173                                 goto reject;
2174                         }
2175                 }
2176
2177                 if (secpath_has_nontransport(sp, k, &xerr_idx)) {
2178                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2179                         goto reject;
2180                 }
2181
2182                 xfrm_pols_put(pols, npols);
2183                 return 1;
2184         }
2185         XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2186
2187 reject:
2188         xfrm_secpath_reject(xerr_idx, skb, &fl);
2189 reject_error:
2190         xfrm_pols_put(pols, npols);
2191         return 0;
2192 }
2193 EXPORT_SYMBOL(__xfrm_policy_check);
2194
2195 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
2196 {
2197         struct net *net = dev_net(skb->dev);
2198         struct flowi fl;
2199         struct dst_entry *dst;
2200         int res = 1;
2201
2202         if (xfrm_decode_session(skb, &fl, family) < 0) {
2203                 XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
2204                 return 0;
2205         }
2206
2207         skb_dst_force(skb);
2208
2209         dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, 0);
2210         if (IS_ERR(dst)) {
2211                 res = 0;
2212                 dst = NULL;
2213         }
2214         skb_dst_set(skb, dst);
2215         return res;
2216 }
2217 EXPORT_SYMBOL(__xfrm_route_forward);
2218
2219 /* Optimize later using cookies and generation ids. */
2220
2221 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
2222 {
2223         /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
2224          * to "-1" to force all XFRM destinations to get validated by
2225          * dst_ops->check on every use.  We do this because when a
2226          * normal route referenced by an XFRM dst is obsoleted we do
2227          * not go looking around for all parent referencing XFRM dsts
2228          * so that we can invalidate them.  It is just too much work.
2229          * Instead we make the checks here on every use.  For example:
2230          *
2231          *      XFRM dst A --> IPv4 dst X
2232          *
2233          * X is the "xdst->route" of A (X is also the "dst->path" of A
2234          * in this example).  If X is marked obsolete, "A" will not
2235          * notice.  That's what we are validating here via the
2236          * stale_bundle() check.
2237          *
2238          * When a policy's bundle is pruned, we dst_free() the XFRM
2239          * dst which causes it's ->obsolete field to be set to a
2240          * positive non-zero integer.  If an XFRM dst has been pruned
2241          * like this, we want to force a new route lookup.
2242          */
2243         if (dst->obsolete < 0 && !stale_bundle(dst))
2244                 return dst;
2245
2246         return NULL;
2247 }
2248
2249 static int stale_bundle(struct dst_entry *dst)
2250 {
2251         return !xfrm_bundle_ok((struct xfrm_dst *)dst);
2252 }
2253
2254 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
2255 {
2256         while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
2257                 dst->dev = dev_net(dev)->loopback_dev;
2258                 dev_hold(dst->dev);
2259                 dev_put(dev);
2260         }
2261 }
2262 EXPORT_SYMBOL(xfrm_dst_ifdown);
2263
2264 static void xfrm_link_failure(struct sk_buff *skb)
2265 {
2266         /* Impossible. Such dst must be popped before reaches point of failure. */
2267 }
2268
2269 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
2270 {
2271         if (dst) {
2272                 if (dst->obsolete) {
2273                         dst_release(dst);
2274                         dst = NULL;
2275                 }
2276         }
2277         return dst;
2278 }
2279
2280 static void __xfrm_garbage_collect(struct net *net)
2281 {
2282         struct dst_entry *head, *next;
2283
2284         spin_lock_bh(&xfrm_policy_sk_bundle_lock);
2285         head = xfrm_policy_sk_bundles;
2286         xfrm_policy_sk_bundles = NULL;
2287         spin_unlock_bh(&xfrm_policy_sk_bundle_lock);
2288
2289         while (head) {
2290                 next = head->next;
2291                 dst_free(head);
2292                 head = next;
2293         }
2294 }
2295
2296 static void xfrm_garbage_collect(struct net *net)
2297 {
2298         flow_cache_flush();
2299         __xfrm_garbage_collect(net);
2300 }
2301
2302 static void xfrm_garbage_collect_deferred(struct net *net)
2303 {
2304         flow_cache_flush_deferred();
2305         __xfrm_garbage_collect(net);
2306 }
2307
2308 static void xfrm_init_pmtu(struct dst_entry *dst)
2309 {
2310         do {
2311                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2312                 u32 pmtu, route_mtu_cached;
2313
2314                 pmtu = dst_mtu(dst->child);
2315                 xdst->child_mtu_cached = pmtu;
2316
2317                 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
2318
2319                 route_mtu_cached = dst_mtu(xdst->route);
2320                 xdst->route_mtu_cached = route_mtu_cached;
2321
2322                 if (pmtu > route_mtu_cached)
2323                         pmtu = route_mtu_cached;
2324
2325                 dst_metric_set(dst, RTAX_MTU, pmtu);
2326         } while ((dst = dst->next));
2327 }
2328
2329 /* Check that the bundle accepts the flow and its components are
2330  * still valid.
2331  */
2332
2333 static int xfrm_bundle_ok(struct xfrm_dst *first)
2334 {
2335         struct dst_entry *dst = &first->u.dst;
2336         struct xfrm_dst *last;
2337         u32 mtu;
2338
2339         if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) ||
2340             (dst->dev && !netif_running(dst->dev)))
2341                 return 0;
2342
2343         last = NULL;
2344
2345         do {
2346                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2347
2348                 if (dst->xfrm->km.state != XFRM_STATE_VALID)
2349                         return 0;
2350                 if (xdst->xfrm_genid != dst->xfrm->genid)
2351                         return 0;
2352                 if (xdst->num_pols > 0 &&
2353                     xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
2354                         return 0;
2355
2356                 mtu = dst_mtu(dst->child);
2357                 if (xdst->child_mtu_cached != mtu) {
2358                         last = xdst;
2359                         xdst->child_mtu_cached = mtu;
2360                 }
2361
2362                 if (!dst_check(xdst->route, xdst->route_cookie))
2363                         return 0;
2364                 mtu = dst_mtu(xdst->route);
2365                 if (xdst->route_mtu_cached != mtu) {
2366                         last = xdst;
2367                         xdst->route_mtu_cached = mtu;
2368                 }
2369
2370                 dst = dst->child;
2371         } while (dst->xfrm);
2372
2373         if (likely(!last))
2374                 return 1;
2375
2376         mtu = last->child_mtu_cached;
2377         for (;;) {
2378                 dst = &last->u.dst;
2379
2380                 mtu = xfrm_state_mtu(dst->xfrm, mtu);
2381                 if (mtu > last->route_mtu_cached)
2382                         mtu = last->route_mtu_cached;
2383                 dst_metric_set(dst, RTAX_MTU, mtu);
2384
2385                 if (last == first)
2386                         break;
2387
2388                 last = (struct xfrm_dst *)last->u.dst.next;
2389                 last->child_mtu_cached = mtu;
2390         }
2391
2392         return 1;
2393 }
2394
2395 static unsigned int xfrm_default_advmss(const struct dst_entry *dst)
2396 {
2397         return dst_metric_advmss(dst->path);
2398 }
2399
2400 static unsigned int xfrm_mtu(const struct dst_entry *dst)
2401 {
2402         unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2403
2404         return mtu ? : dst_mtu(dst->path);
2405 }
2406
2407 static struct neighbour *xfrm_neigh_lookup(const struct dst_entry *dst, const void *daddr)
2408 {
2409         return dst_neigh_lookup(dst->path, daddr);
2410 }
2411
2412 int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
2413 {
2414         struct net *net;
2415         int err = 0;
2416         if (unlikely(afinfo == NULL))
2417                 return -EINVAL;
2418         if (unlikely(afinfo->family >= NPROTO))
2419                 return -EAFNOSUPPORT;
2420         write_lock_bh(&xfrm_policy_afinfo_lock);
2421         if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
2422                 err = -ENOBUFS;
2423         else {
2424                 struct dst_ops *dst_ops = afinfo->dst_ops;
2425                 if (likely(dst_ops->kmem_cachep == NULL))
2426                         dst_ops->kmem_cachep = xfrm_dst_cache;
2427                 if (likely(dst_ops->check == NULL))
2428                         dst_ops->check = xfrm_dst_check;
2429                 if (likely(dst_ops->default_advmss == NULL))
2430                         dst_ops->default_advmss = xfrm_default_advmss;
2431                 if (likely(dst_ops->mtu == NULL))
2432                         dst_ops->mtu = xfrm_mtu;
2433                 if (likely(dst_ops->negative_advice == NULL))
2434                         dst_ops->negative_advice = xfrm_negative_advice;
2435                 if (likely(dst_ops->link_failure == NULL))
2436                         dst_ops->link_failure = xfrm_link_failure;
2437                 if (likely(dst_ops->neigh_lookup == NULL))
2438                         dst_ops->neigh_lookup = xfrm_neigh_lookup;
2439                 if (likely(afinfo->garbage_collect == NULL))
2440                         afinfo->garbage_collect = xfrm_garbage_collect_deferred;
2441                 xfrm_policy_afinfo[afinfo->family] = afinfo;
2442         }
2443         write_unlock_bh(&xfrm_policy_afinfo_lock);
2444
2445         rtnl_lock();
2446         for_each_net(net) {
2447                 struct dst_ops *xfrm_dst_ops;
2448
2449                 switch (afinfo->family) {
2450                 case AF_INET:
2451                         xfrm_dst_ops = &net->xfrm.xfrm4_dst_ops;
2452                         break;
2453 #if IS_ENABLED(CONFIG_IPV6)
2454                 case AF_INET6:
2455                         xfrm_dst_ops = &net->xfrm.xfrm6_dst_ops;
2456                         break;
2457 #endif
2458                 default:
2459                         BUG();
2460                 }
2461                 *xfrm_dst_ops = *afinfo->dst_ops;
2462         }
2463         rtnl_unlock();
2464
2465         return err;
2466 }
2467 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
2468
2469 int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
2470 {
2471         int err = 0;
2472         if (unlikely(afinfo == NULL))
2473                 return -EINVAL;
2474         if (unlikely(afinfo->family >= NPROTO))
2475                 return -EAFNOSUPPORT;
2476         write_lock_bh(&xfrm_policy_afinfo_lock);
2477         if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
2478                 if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
2479                         err = -EINVAL;
2480                 else {
2481                         struct dst_ops *dst_ops = afinfo->dst_ops;
2482                         xfrm_policy_afinfo[afinfo->family] = NULL;
2483                         dst_ops->kmem_cachep = NULL;
2484                         dst_ops->check = NULL;
2485                         dst_ops->negative_advice = NULL;
2486                         dst_ops->link_failure = NULL;
2487                         afinfo->garbage_collect = NULL;
2488                 }
2489         }
2490         write_unlock_bh(&xfrm_policy_afinfo_lock);
2491         return err;
2492 }
2493 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
2494
2495 static void __net_init xfrm_dst_ops_init(struct net *net)
2496 {
2497         struct xfrm_policy_afinfo *afinfo;
2498
2499         read_lock_bh(&xfrm_policy_afinfo_lock);
2500         afinfo = xfrm_policy_afinfo[AF_INET];
2501         if (afinfo)
2502                 net->xfrm.xfrm4_dst_ops = *afinfo->dst_ops;
2503 #if IS_ENABLED(CONFIG_IPV6)
2504         afinfo = xfrm_policy_afinfo[AF_INET6];
2505         if (afinfo)
2506                 net->xfrm.xfrm6_dst_ops = *afinfo->dst_ops;
2507 #endif
2508         read_unlock_bh(&xfrm_policy_afinfo_lock);
2509 }
2510
2511 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
2512 {
2513         struct xfrm_policy_afinfo *afinfo;
2514         if (unlikely(family >= NPROTO))
2515                 return NULL;
2516         read_lock(&xfrm_policy_afinfo_lock);
2517         afinfo = xfrm_policy_afinfo[family];
2518         if (unlikely(!afinfo))
2519                 read_unlock(&xfrm_policy_afinfo_lock);
2520         return afinfo;
2521 }
2522
2523 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
2524 {
2525         read_unlock(&xfrm_policy_afinfo_lock);
2526 }
2527
2528 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
2529 {
2530         struct net_device *dev = ptr;
2531
2532         switch (event) {
2533         case NETDEV_DOWN:
2534                 xfrm_garbage_collect(dev_net(dev));
2535         }
2536         return NOTIFY_DONE;
2537 }
2538
2539 static struct notifier_block xfrm_dev_notifier = {
2540         .notifier_call  = xfrm_dev_event,
2541 };
2542
2543 #ifdef CONFIG_XFRM_STATISTICS
2544 static int __net_init xfrm_statistics_init(struct net *net)
2545 {
2546         int rv;
2547
2548         if (snmp_mib_init((void __percpu **)net->mib.xfrm_statistics,
2549                           sizeof(struct linux_xfrm_mib),
2550                           __alignof__(struct linux_xfrm_mib)) < 0)
2551                 return -ENOMEM;
2552         rv = xfrm_proc_init(net);
2553         if (rv < 0)
2554                 snmp_mib_free((void __percpu **)net->mib.xfrm_statistics);
2555         return rv;
2556 }
2557
2558 static void xfrm_statistics_fini(struct net *net)
2559 {
2560         xfrm_proc_fini(net);
2561         snmp_mib_free((void __percpu **)net->mib.xfrm_statistics);
2562 }
2563 #else
2564 static int __net_init xfrm_statistics_init(struct net *net)
2565 {
2566         return 0;
2567 }
2568
2569 static void xfrm_statistics_fini(struct net *net)
2570 {
2571 }
2572 #endif
2573
2574 static int __net_init xfrm_policy_init(struct net *net)
2575 {
2576         unsigned int hmask, sz;
2577         int dir;
2578
2579         if (net_eq(net, &init_net))
2580                 xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
2581                                            sizeof(struct xfrm_dst),
2582                                            0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
2583                                            NULL);
2584
2585         hmask = 8 - 1;
2586         sz = (hmask+1) * sizeof(struct hlist_head);
2587
2588         net->xfrm.policy_byidx = xfrm_hash_alloc(sz);
2589         if (!net->xfrm.policy_byidx)
2590                 goto out_byidx;
2591         net->xfrm.policy_idx_hmask = hmask;
2592
2593         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
2594                 struct xfrm_policy_hash *htab;
2595
2596                 net->xfrm.policy_count[dir] = 0;
2597                 INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
2598
2599                 htab = &net->xfrm.policy_bydst[dir];
2600                 htab->table = xfrm_hash_alloc(sz);
2601                 if (!htab->table)
2602                         goto out_bydst;
2603                 htab->hmask = hmask;
2604         }
2605
2606         INIT_LIST_HEAD(&net->xfrm.policy_all);
2607         INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
2608         if (net_eq(net, &init_net))
2609                 register_netdevice_notifier(&xfrm_dev_notifier);
2610         return 0;
2611
2612 out_bydst:
2613         for (dir--; dir >= 0; dir--) {
2614                 struct xfrm_policy_hash *htab;
2615
2616                 htab = &net->xfrm.policy_bydst[dir];
2617                 xfrm_hash_free(htab->table, sz);
2618         }
2619         xfrm_hash_free(net->xfrm.policy_byidx, sz);
2620 out_byidx:
2621         return -ENOMEM;
2622 }
2623
2624 static void xfrm_policy_fini(struct net *net)
2625 {
2626         struct xfrm_audit audit_info;
2627         unsigned int sz;
2628         int dir;
2629
2630         flush_work(&net->xfrm.policy_hash_work);
2631 #ifdef CONFIG_XFRM_SUB_POLICY
2632         audit_info.loginuid = -1;
2633         audit_info.sessionid = -1;
2634         audit_info.secid = 0;
2635         xfrm_policy_flush(net, XFRM_POLICY_TYPE_SUB, &audit_info);
2636 #endif
2637         audit_info.loginuid = -1;
2638         audit_info.sessionid = -1;
2639         audit_info.secid = 0;
2640         xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, &audit_info);
2641
2642         WARN_ON(!list_empty(&net->xfrm.policy_all));
2643
2644         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
2645                 struct xfrm_policy_hash *htab;
2646
2647                 WARN_ON(!hlist_empty(&net->xfrm.policy_inexact[dir]));
2648
2649                 htab = &net->xfrm.policy_bydst[dir];
2650                 sz = (htab->hmask + 1);
2651                 WARN_ON(!hlist_empty(htab->table));
2652                 xfrm_hash_free(htab->table, sz);
2653         }
2654
2655         sz = (net->xfrm.policy_idx_hmask + 1) * sizeof(struct hlist_head);
2656         WARN_ON(!hlist_empty(net->xfrm.policy_byidx));
2657         xfrm_hash_free(net->xfrm.policy_byidx, sz);
2658 }
2659
2660 static int __net_init xfrm_net_init(struct net *net)
2661 {
2662         int rv;
2663
2664         rv = xfrm_statistics_init(net);
2665         if (rv < 0)
2666                 goto out_statistics;
2667         rv = xfrm_state_init(net);
2668         if (rv < 0)
2669                 goto out_state;
2670         rv = xfrm_policy_init(net);
2671         if (rv < 0)
2672                 goto out_policy;
2673         xfrm_dst_ops_init(net);
2674         rv = xfrm_sysctl_init(net);
2675         if (rv < 0)
2676                 goto out_sysctl;
2677         return 0;
2678
2679 out_sysctl:
2680         xfrm_policy_fini(net);
2681 out_policy:
2682         xfrm_state_fini(net);
2683 out_state:
2684         xfrm_statistics_fini(net);
2685 out_statistics:
2686         return rv;
2687 }
2688
2689 static void __net_exit xfrm_net_exit(struct net *net)
2690 {
2691         xfrm_sysctl_fini(net);
2692         xfrm_policy_fini(net);
2693         xfrm_state_fini(net);
2694         xfrm_statistics_fini(net);
2695 }
2696
2697 static struct pernet_operations __net_initdata xfrm_net_ops = {
2698         .init = xfrm_net_init,
2699         .exit = xfrm_net_exit,
2700 };
2701
2702 void __init xfrm_init(void)
2703 {
2704         register_pernet_subsys(&xfrm_net_ops);
2705         xfrm_input_init();
2706 }
2707
2708 #ifdef CONFIG_AUDITSYSCALL
2709 static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
2710                                          struct audit_buffer *audit_buf)
2711 {
2712         struct xfrm_sec_ctx *ctx = xp->security;
2713         struct xfrm_selector *sel = &xp->selector;
2714
2715         if (ctx)
2716                 audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
2717                                  ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str);
2718
2719         switch(sel->family) {
2720         case AF_INET:
2721                 audit_log_format(audit_buf, " src=%pI4", &sel->saddr.a4);
2722                 if (sel->prefixlen_s != 32)
2723                         audit_log_format(audit_buf, " src_prefixlen=%d",
2724                                          sel->prefixlen_s);
2725                 audit_log_format(audit_buf, " dst=%pI4", &sel->daddr.a4);
2726                 if (sel->prefixlen_d != 32)
2727                         audit_log_format(audit_buf, " dst_prefixlen=%d",
2728                                          sel->prefixlen_d);
2729                 break;
2730         case AF_INET6:
2731                 audit_log_format(audit_buf, " src=%pI6", sel->saddr.a6);
2732                 if (sel->prefixlen_s != 128)
2733                         audit_log_format(audit_buf, " src_prefixlen=%d",
2734                                          sel->prefixlen_s);
2735                 audit_log_format(audit_buf, " dst=%pI6", sel->daddr.a6);
2736                 if (sel->prefixlen_d != 128)
2737                         audit_log_format(audit_buf, " dst_prefixlen=%d",
2738                                          sel->prefixlen_d);
2739                 break;
2740         }
2741 }
2742
2743 void xfrm_audit_policy_add(struct xfrm_policy *xp, int result,
2744                            uid_t auid, u32 sessionid, u32 secid)
2745 {
2746         struct audit_buffer *audit_buf;
2747
2748         audit_buf = xfrm_audit_start("SPD-add");
2749         if (audit_buf == NULL)
2750                 return;
2751         xfrm_audit_helper_usrinfo(auid, sessionid, secid, audit_buf);
2752         audit_log_format(audit_buf, " res=%u", result);
2753         xfrm_audit_common_policyinfo(xp, audit_buf);
2754         audit_log_end(audit_buf);
2755 }
2756 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
2757
2758 void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
2759                               uid_t auid, u32 sessionid, u32 secid)
2760 {
2761         struct audit_buffer *audit_buf;
2762
2763         audit_buf = xfrm_audit_start("SPD-delete");
2764         if (audit_buf == NULL)
2765                 return;
2766         xfrm_audit_helper_usrinfo(auid, sessionid, secid, audit_buf);
2767         audit_log_format(audit_buf, " res=%u", result);
2768         xfrm_audit_common_policyinfo(xp, audit_buf);
2769         audit_log_end(audit_buf);
2770 }
2771 EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
2772 #endif
2773
2774 #ifdef CONFIG_XFRM_MIGRATE
2775 static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp,
2776                                         const struct xfrm_selector *sel_tgt)
2777 {
2778         if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
2779                 if (sel_tgt->family == sel_cmp->family &&
2780                     xfrm_addr_cmp(&sel_tgt->daddr, &sel_cmp->daddr,
2781                                   sel_cmp->family) == 0 &&
2782                     xfrm_addr_cmp(&sel_tgt->saddr, &sel_cmp->saddr,
2783                                   sel_cmp->family) == 0 &&
2784                     sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
2785                     sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
2786                         return true;
2787                 }
2788         } else {
2789                 if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
2790                         return true;
2791                 }
2792         }
2793         return false;
2794 }
2795
2796 static struct xfrm_policy * xfrm_migrate_policy_find(const struct xfrm_selector *sel,
2797                                                      u8 dir, u8 type)
2798 {
2799         struct xfrm_policy *pol, *ret = NULL;
2800         struct hlist_node *entry;
2801         struct hlist_head *chain;
2802         u32 priority = ~0U;
2803
2804         read_lock_bh(&xfrm_policy_lock);
2805         chain = policy_hash_direct(&init_net, &sel->daddr, &sel->saddr, sel->family, dir);
2806         hlist_for_each_entry(pol, entry, chain, bydst) {
2807                 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
2808                     pol->type == type) {
2809                         ret = pol;
2810                         priority = ret->priority;
2811                         break;
2812                 }
2813         }
2814         chain = &init_net.xfrm.policy_inexact[dir];
2815         hlist_for_each_entry(pol, entry, chain, bydst) {
2816                 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
2817                     pol->type == type &&
2818                     pol->priority < priority) {
2819                         ret = pol;
2820                         break;
2821                 }
2822         }
2823
2824         if (ret)
2825                 xfrm_pol_hold(ret);
2826
2827         read_unlock_bh(&xfrm_policy_lock);
2828
2829         return ret;
2830 }
2831
2832 static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t)
2833 {
2834         int match = 0;
2835
2836         if (t->mode == m->mode && t->id.proto == m->proto &&
2837             (m->reqid == 0 || t->reqid == m->reqid)) {
2838                 switch (t->mode) {
2839                 case XFRM_MODE_TUNNEL:
2840                 case XFRM_MODE_BEET:
2841                         if (xfrm_addr_cmp(&t->id.daddr, &m->old_daddr,
2842                                           m->old_family) == 0 &&
2843                             xfrm_addr_cmp(&t->saddr, &m->old_saddr,
2844                                           m->old_family) == 0) {
2845                                 match = 1;
2846                         }
2847                         break;
2848                 case XFRM_MODE_TRANSPORT:
2849                         /* in case of transport mode, template does not store
2850                            any IP addresses, hence we just compare mode and
2851                            protocol */
2852                         match = 1;
2853                         break;
2854                 default:
2855                         break;
2856                 }
2857         }
2858         return match;
2859 }
2860
2861 /* update endpoint address(es) of template(s) */
2862 static int xfrm_policy_migrate(struct xfrm_policy *pol,
2863                                struct xfrm_migrate *m, int num_migrate)
2864 {
2865         struct xfrm_migrate *mp;
2866         int i, j, n = 0;
2867
2868         write_lock_bh(&pol->lock);
2869         if (unlikely(pol->walk.dead)) {
2870                 /* target policy has been deleted */
2871                 write_unlock_bh(&pol->lock);
2872                 return -ENOENT;
2873         }
2874
2875         for (i = 0; i < pol->xfrm_nr; i++) {
2876                 for (j = 0, mp = m; j < num_migrate; j++, mp++) {
2877                         if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
2878                                 continue;
2879                         n++;
2880                         if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
2881                             pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
2882                                 continue;
2883                         /* update endpoints */
2884                         memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
2885                                sizeof(pol->xfrm_vec[i].id.daddr));
2886                         memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
2887                                sizeof(pol->xfrm_vec[i].saddr));
2888                         pol->xfrm_vec[i].encap_family = mp->new_family;
2889                         /* flush bundles */
2890                         atomic_inc(&pol->genid);
2891                 }
2892         }
2893
2894         write_unlock_bh(&pol->lock);
2895
2896         if (!n)
2897                 return -ENODATA;
2898
2899         return 0;
2900 }
2901
2902 static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate)
2903 {
2904         int i, j;
2905
2906         if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
2907                 return -EINVAL;
2908
2909         for (i = 0; i < num_migrate; i++) {
2910                 if ((xfrm_addr_cmp(&m[i].old_daddr, &m[i].new_daddr,
2911                                    m[i].old_family) == 0) &&
2912                     (xfrm_addr_cmp(&m[i].old_saddr, &m[i].new_saddr,
2913                                    m[i].old_family) == 0))
2914                         return -EINVAL;
2915                 if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
2916                     xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
2917                         return -EINVAL;
2918
2919                 /* check if there is any duplicated entry */
2920                 for (j = i + 1; j < num_migrate; j++) {
2921                         if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
2922                                     sizeof(m[i].old_daddr)) &&
2923                             !memcmp(&m[i].old_saddr, &m[j].old_saddr,
2924                                     sizeof(m[i].old_saddr)) &&
2925                             m[i].proto == m[j].proto &&
2926                             m[i].mode == m[j].mode &&
2927                             m[i].reqid == m[j].reqid &&
2928                             m[i].old_family == m[j].old_family)
2929                                 return -EINVAL;
2930                 }
2931         }
2932
2933         return 0;
2934 }
2935
2936 int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
2937                  struct xfrm_migrate *m, int num_migrate,
2938                  struct xfrm_kmaddress *k)
2939 {
2940         int i, err, nx_cur = 0, nx_new = 0;
2941         struct xfrm_policy *pol = NULL;
2942         struct xfrm_state *x, *xc;
2943         struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
2944         struct xfrm_state *x_new[XFRM_MAX_DEPTH];
2945         struct xfrm_migrate *mp;
2946
2947         if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
2948                 goto out;
2949
2950         /* Stage 1 - find policy */
2951         if ((pol = xfrm_migrate_policy_find(sel, dir, type)) == NULL) {
2952                 err = -ENOENT;
2953                 goto out;
2954         }
2955
2956         /* Stage 2 - find and update state(s) */
2957         for (i = 0, mp = m; i < num_migrate; i++, mp++) {
2958                 if ((x = xfrm_migrate_state_find(mp))) {
2959                         x_cur[nx_cur] = x;
2960                         nx_cur++;
2961                         if ((xc = xfrm_state_migrate(x, mp))) {
2962                                 x_new[nx_new] = xc;
2963                                 nx_new++;
2964                         } else {
2965                                 err = -ENODATA;
2966                                 goto restore_state;
2967                         }
2968                 }
2969         }
2970
2971         /* Stage 3 - update policy */
2972         if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
2973                 goto restore_state;
2974
2975         /* Stage 4 - delete old state(s) */
2976         if (nx_cur) {
2977                 xfrm_states_put(x_cur, nx_cur);
2978                 xfrm_states_delete(x_cur, nx_cur);
2979         }
2980
2981         /* Stage 5 - announce */
2982         km_migrate(sel, dir, type, m, num_migrate, k);
2983
2984         xfrm_pol_put(pol);
2985
2986         return 0;
2987 out:
2988         return err;
2989
2990 restore_state:
2991         if (pol)
2992                 xfrm_pol_put(pol);
2993         if (nx_cur)
2994                 xfrm_states_put(x_cur, nx_cur);
2995         if (nx_new)
2996                 xfrm_states_delete(x_new, nx_new);
2997
2998         return err;
2999 }
3000 EXPORT_SYMBOL(xfrm_migrate);
3001 #endif