Merge tag 'acpi-5.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...
[sfrench/cifs-2.6.git] / net / xfrm / xfrm_policy.c
1 /*
2  * xfrm_policy.c
3  *
4  * Changes:
5  *      Mitsuru KANDA @USAGI
6  *      Kazunori MIYAZAWA @USAGI
7  *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
8  *              IPv6 support
9  *      Kazunori MIYAZAWA @USAGI
10  *      YOSHIFUJI Hideaki
11  *              Split up af-specific portion
12  *      Derek Atkins <derek@ihtfp.com>          Add the post_input processor
13  *
14  */
15
16 #include <linux/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/cpu.h>
28 #include <linux/audit.h>
29 #include <linux/rhashtable.h>
30 #include <net/dst.h>
31 #include <net/flow.h>
32 #include <net/xfrm.h>
33 #include <net/ip.h>
34 #ifdef CONFIG_XFRM_STATISTICS
35 #include <net/snmp.h>
36 #endif
37
38 #include "xfrm_hash.h"
39
40 #define XFRM_QUEUE_TMO_MIN ((unsigned)(HZ/10))
41 #define XFRM_QUEUE_TMO_MAX ((unsigned)(60*HZ))
42 #define XFRM_MAX_QUEUE_LEN      100
43
44 struct xfrm_flo {
45         struct dst_entry *dst_orig;
46         u8 flags;
47 };
48
49 /* prefixes smaller than this are stored in lists, not trees. */
50 #define INEXACT_PREFIXLEN_IPV4  16
51 #define INEXACT_PREFIXLEN_IPV6  48
52
53 struct xfrm_pol_inexact_node {
54         struct rb_node node;
55         union {
56                 xfrm_address_t addr;
57                 struct rcu_head rcu;
58         };
59         u8 prefixlen;
60
61         struct rb_root root;
62
63         /* the policies matching this node, can be empty list */
64         struct hlist_head hhead;
65 };
66
67 /* xfrm inexact policy search tree:
68  * xfrm_pol_inexact_bin = hash(dir,type,family,if_id);
69  *  |
70  * +---- root_d: sorted by daddr:prefix
71  * |                 |
72  * |        xfrm_pol_inexact_node
73  * |                 |
74  * |                 +- root: sorted by saddr/prefix
75  * |                 |              |
76  * |                 |         xfrm_pol_inexact_node
77  * |                 |              |
78  * |                 |              + root: unused
79  * |                 |              |
80  * |                 |              + hhead: saddr:daddr policies
81  * |                 |
82  * |                 +- coarse policies and all any:daddr policies
83  * |
84  * +---- root_s: sorted by saddr:prefix
85  * |                 |
86  * |        xfrm_pol_inexact_node
87  * |                 |
88  * |                 + root: unused
89  * |                 |
90  * |                 + hhead: saddr:any policies
91  * |
92  * +---- coarse policies and all any:any policies
93  *
94  * Lookups return four candidate lists:
95  * 1. any:any list from top-level xfrm_pol_inexact_bin
96  * 2. any:daddr list from daddr tree
97  * 3. saddr:daddr list from 2nd level daddr tree
98  * 4. saddr:any list from saddr tree
99  *
100  * This result set then needs to be searched for the policy with
101  * the lowest priority.  If two results have same prio, youngest one wins.
102  */
103
104 struct xfrm_pol_inexact_key {
105         possible_net_t net;
106         u32 if_id;
107         u16 family;
108         u8 dir, type;
109 };
110
111 struct xfrm_pol_inexact_bin {
112         struct xfrm_pol_inexact_key k;
113         struct rhash_head head;
114         /* list containing '*:*' policies */
115         struct hlist_head hhead;
116
117         seqcount_t count;
118         /* tree sorted by daddr/prefix */
119         struct rb_root root_d;
120
121         /* tree sorted by saddr/prefix */
122         struct rb_root root_s;
123
124         /* slow path below */
125         struct list_head inexact_bins;
126         struct rcu_head rcu;
127 };
128
129 enum xfrm_pol_inexact_candidate_type {
130         XFRM_POL_CAND_BOTH,
131         XFRM_POL_CAND_SADDR,
132         XFRM_POL_CAND_DADDR,
133         XFRM_POL_CAND_ANY,
134
135         XFRM_POL_CAND_MAX,
136 };
137
138 struct xfrm_pol_inexact_candidates {
139         struct hlist_head *res[XFRM_POL_CAND_MAX];
140 };
141
142 static DEFINE_SPINLOCK(xfrm_if_cb_lock);
143 static struct xfrm_if_cb const __rcu *xfrm_if_cb __read_mostly;
144
145 static DEFINE_SPINLOCK(xfrm_policy_afinfo_lock);
146 static struct xfrm_policy_afinfo const __rcu *xfrm_policy_afinfo[AF_INET6 + 1]
147                                                 __read_mostly;
148
149 static struct kmem_cache *xfrm_dst_cache __ro_after_init;
150 static __read_mostly seqcount_t xfrm_policy_hash_generation;
151
152 static struct rhashtable xfrm_policy_inexact_table;
153 static const struct rhashtable_params xfrm_pol_inexact_params;
154
155 static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr);
156 static int stale_bundle(struct dst_entry *dst);
157 static int xfrm_bundle_ok(struct xfrm_dst *xdst);
158 static void xfrm_policy_queue_process(struct timer_list *t);
159
160 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir);
161 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
162                                                 int dir);
163
164 static struct xfrm_pol_inexact_bin *
165 xfrm_policy_inexact_lookup(struct net *net, u8 type, u16 family, u8 dir,
166                            u32 if_id);
167
168 static struct xfrm_pol_inexact_bin *
169 xfrm_policy_inexact_lookup_rcu(struct net *net,
170                                u8 type, u16 family, u8 dir, u32 if_id);
171 static struct xfrm_policy *
172 xfrm_policy_insert_list(struct hlist_head *chain, struct xfrm_policy *policy,
173                         bool excl);
174 static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
175                                             struct xfrm_policy *policy);
176
177 static bool
178 xfrm_policy_find_inexact_candidates(struct xfrm_pol_inexact_candidates *cand,
179                                     struct xfrm_pol_inexact_bin *b,
180                                     const xfrm_address_t *saddr,
181                                     const xfrm_address_t *daddr);
182
183 static inline bool xfrm_pol_hold_rcu(struct xfrm_policy *policy)
184 {
185         return refcount_inc_not_zero(&policy->refcnt);
186 }
187
188 static inline bool
189 __xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
190 {
191         const struct flowi4 *fl4 = &fl->u.ip4;
192
193         return  addr4_match(fl4->daddr, sel->daddr.a4, sel->prefixlen_d) &&
194                 addr4_match(fl4->saddr, sel->saddr.a4, sel->prefixlen_s) &&
195                 !((xfrm_flowi_dport(fl, &fl4->uli) ^ sel->dport) & sel->dport_mask) &&
196                 !((xfrm_flowi_sport(fl, &fl4->uli) ^ sel->sport) & sel->sport_mask) &&
197                 (fl4->flowi4_proto == sel->proto || !sel->proto) &&
198                 (fl4->flowi4_oif == sel->ifindex || !sel->ifindex);
199 }
200
201 static inline bool
202 __xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
203 {
204         const struct flowi6 *fl6 = &fl->u.ip6;
205
206         return  addr_match(&fl6->daddr, &sel->daddr, sel->prefixlen_d) &&
207                 addr_match(&fl6->saddr, &sel->saddr, sel->prefixlen_s) &&
208                 !((xfrm_flowi_dport(fl, &fl6->uli) ^ sel->dport) & sel->dport_mask) &&
209                 !((xfrm_flowi_sport(fl, &fl6->uli) ^ sel->sport) & sel->sport_mask) &&
210                 (fl6->flowi6_proto == sel->proto || !sel->proto) &&
211                 (fl6->flowi6_oif == sel->ifindex || !sel->ifindex);
212 }
213
214 bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl,
215                          unsigned short family)
216 {
217         switch (family) {
218         case AF_INET:
219                 return __xfrm4_selector_match(sel, fl);
220         case AF_INET6:
221                 return __xfrm6_selector_match(sel, fl);
222         }
223         return false;
224 }
225
226 static const struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
227 {
228         const struct xfrm_policy_afinfo *afinfo;
229
230         if (unlikely(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
231                 return NULL;
232         rcu_read_lock();
233         afinfo = rcu_dereference(xfrm_policy_afinfo[family]);
234         if (unlikely(!afinfo))
235                 rcu_read_unlock();
236         return afinfo;
237 }
238
239 /* Called with rcu_read_lock(). */
240 static const struct xfrm_if_cb *xfrm_if_get_cb(void)
241 {
242         return rcu_dereference(xfrm_if_cb);
243 }
244
245 struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos, int oif,
246                                     const xfrm_address_t *saddr,
247                                     const xfrm_address_t *daddr,
248                                     int family, u32 mark)
249 {
250         const struct xfrm_policy_afinfo *afinfo;
251         struct dst_entry *dst;
252
253         afinfo = xfrm_policy_get_afinfo(family);
254         if (unlikely(afinfo == NULL))
255                 return ERR_PTR(-EAFNOSUPPORT);
256
257         dst = afinfo->dst_lookup(net, tos, oif, saddr, daddr, mark);
258
259         rcu_read_unlock();
260
261         return dst;
262 }
263 EXPORT_SYMBOL(__xfrm_dst_lookup);
264
265 static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x,
266                                                 int tos, int oif,
267                                                 xfrm_address_t *prev_saddr,
268                                                 xfrm_address_t *prev_daddr,
269                                                 int family, u32 mark)
270 {
271         struct net *net = xs_net(x);
272         xfrm_address_t *saddr = &x->props.saddr;
273         xfrm_address_t *daddr = &x->id.daddr;
274         struct dst_entry *dst;
275
276         if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) {
277                 saddr = x->coaddr;
278                 daddr = prev_daddr;
279         }
280         if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) {
281                 saddr = prev_saddr;
282                 daddr = x->coaddr;
283         }
284
285         dst = __xfrm_dst_lookup(net, tos, oif, saddr, daddr, family, mark);
286
287         if (!IS_ERR(dst)) {
288                 if (prev_saddr != saddr)
289                         memcpy(prev_saddr, saddr,  sizeof(*prev_saddr));
290                 if (prev_daddr != daddr)
291                         memcpy(prev_daddr, daddr,  sizeof(*prev_daddr));
292         }
293
294         return dst;
295 }
296
297 static inline unsigned long make_jiffies(long secs)
298 {
299         if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
300                 return MAX_SCHEDULE_TIMEOUT-1;
301         else
302                 return secs*HZ;
303 }
304
305 static void xfrm_policy_timer(struct timer_list *t)
306 {
307         struct xfrm_policy *xp = from_timer(xp, t, timer);
308         time64_t now = ktime_get_real_seconds();
309         time64_t next = TIME64_MAX;
310         int warn = 0;
311         int dir;
312
313         read_lock(&xp->lock);
314
315         if (unlikely(xp->walk.dead))
316                 goto out;
317
318         dir = xfrm_policy_id2dir(xp->index);
319
320         if (xp->lft.hard_add_expires_seconds) {
321                 time64_t tmo = xp->lft.hard_add_expires_seconds +
322                         xp->curlft.add_time - now;
323                 if (tmo <= 0)
324                         goto expired;
325                 if (tmo < next)
326                         next = tmo;
327         }
328         if (xp->lft.hard_use_expires_seconds) {
329                 time64_t tmo = xp->lft.hard_use_expires_seconds +
330                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
331                 if (tmo <= 0)
332                         goto expired;
333                 if (tmo < next)
334                         next = tmo;
335         }
336         if (xp->lft.soft_add_expires_seconds) {
337                 time64_t tmo = xp->lft.soft_add_expires_seconds +
338                         xp->curlft.add_time - now;
339                 if (tmo <= 0) {
340                         warn = 1;
341                         tmo = XFRM_KM_TIMEOUT;
342                 }
343                 if (tmo < next)
344                         next = tmo;
345         }
346         if (xp->lft.soft_use_expires_seconds) {
347                 time64_t tmo = xp->lft.soft_use_expires_seconds +
348                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
349                 if (tmo <= 0) {
350                         warn = 1;
351                         tmo = XFRM_KM_TIMEOUT;
352                 }
353                 if (tmo < next)
354                         next = tmo;
355         }
356
357         if (warn)
358                 km_policy_expired(xp, dir, 0, 0);
359         if (next != TIME64_MAX &&
360             !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
361                 xfrm_pol_hold(xp);
362
363 out:
364         read_unlock(&xp->lock);
365         xfrm_pol_put(xp);
366         return;
367
368 expired:
369         read_unlock(&xp->lock);
370         if (!xfrm_policy_delete(xp, dir))
371                 km_policy_expired(xp, dir, 1, 0);
372         xfrm_pol_put(xp);
373 }
374
375 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
376  * SPD calls.
377  */
378
379 struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
380 {
381         struct xfrm_policy *policy;
382
383         policy = kzalloc(sizeof(struct xfrm_policy), gfp);
384
385         if (policy) {
386                 write_pnet(&policy->xp_net, net);
387                 INIT_LIST_HEAD(&policy->walk.all);
388                 INIT_HLIST_NODE(&policy->bydst_inexact_list);
389                 INIT_HLIST_NODE(&policy->bydst);
390                 INIT_HLIST_NODE(&policy->byidx);
391                 rwlock_init(&policy->lock);
392                 refcount_set(&policy->refcnt, 1);
393                 skb_queue_head_init(&policy->polq.hold_queue);
394                 timer_setup(&policy->timer, xfrm_policy_timer, 0);
395                 timer_setup(&policy->polq.hold_timer,
396                             xfrm_policy_queue_process, 0);
397         }
398         return policy;
399 }
400 EXPORT_SYMBOL(xfrm_policy_alloc);
401
402 static void xfrm_policy_destroy_rcu(struct rcu_head *head)
403 {
404         struct xfrm_policy *policy = container_of(head, struct xfrm_policy, rcu);
405
406         security_xfrm_policy_free(policy->security);
407         kfree(policy);
408 }
409
410 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
411
412 void xfrm_policy_destroy(struct xfrm_policy *policy)
413 {
414         BUG_ON(!policy->walk.dead);
415
416         if (del_timer(&policy->timer) || del_timer(&policy->polq.hold_timer))
417                 BUG();
418
419         call_rcu(&policy->rcu, xfrm_policy_destroy_rcu);
420 }
421 EXPORT_SYMBOL(xfrm_policy_destroy);
422
423 /* Rule must be locked. Release descendant resources, announce
424  * entry dead. The rule must be unlinked from lists to the moment.
425  */
426
427 static void xfrm_policy_kill(struct xfrm_policy *policy)
428 {
429         policy->walk.dead = 1;
430
431         atomic_inc(&policy->genid);
432
433         if (del_timer(&policy->polq.hold_timer))
434                 xfrm_pol_put(policy);
435         skb_queue_purge(&policy->polq.hold_queue);
436
437         if (del_timer(&policy->timer))
438                 xfrm_pol_put(policy);
439
440         xfrm_pol_put(policy);
441 }
442
443 static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
444
445 static inline unsigned int idx_hash(struct net *net, u32 index)
446 {
447         return __idx_hash(index, net->xfrm.policy_idx_hmask);
448 }
449
450 /* calculate policy hash thresholds */
451 static void __get_hash_thresh(struct net *net,
452                               unsigned short family, int dir,
453                               u8 *dbits, u8 *sbits)
454 {
455         switch (family) {
456         case AF_INET:
457                 *dbits = net->xfrm.policy_bydst[dir].dbits4;
458                 *sbits = net->xfrm.policy_bydst[dir].sbits4;
459                 break;
460
461         case AF_INET6:
462                 *dbits = net->xfrm.policy_bydst[dir].dbits6;
463                 *sbits = net->xfrm.policy_bydst[dir].sbits6;
464                 break;
465
466         default:
467                 *dbits = 0;
468                 *sbits = 0;
469         }
470 }
471
472 static struct hlist_head *policy_hash_bysel(struct net *net,
473                                             const struct xfrm_selector *sel,
474                                             unsigned short family, int dir)
475 {
476         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
477         unsigned int hash;
478         u8 dbits;
479         u8 sbits;
480
481         __get_hash_thresh(net, family, dir, &dbits, &sbits);
482         hash = __sel_hash(sel, family, hmask, dbits, sbits);
483
484         if (hash == hmask + 1)
485                 return NULL;
486
487         return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
488                      lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
489 }
490
491 static struct hlist_head *policy_hash_direct(struct net *net,
492                                              const xfrm_address_t *daddr,
493                                              const xfrm_address_t *saddr,
494                                              unsigned short family, int dir)
495 {
496         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
497         unsigned int hash;
498         u8 dbits;
499         u8 sbits;
500
501         __get_hash_thresh(net, family, dir, &dbits, &sbits);
502         hash = __addr_hash(daddr, saddr, family, hmask, dbits, sbits);
503
504         return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
505                      lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
506 }
507
508 static void xfrm_dst_hash_transfer(struct net *net,
509                                    struct hlist_head *list,
510                                    struct hlist_head *ndsttable,
511                                    unsigned int nhashmask,
512                                    int dir)
513 {
514         struct hlist_node *tmp, *entry0 = NULL;
515         struct xfrm_policy *pol;
516         unsigned int h0 = 0;
517         u8 dbits;
518         u8 sbits;
519
520 redo:
521         hlist_for_each_entry_safe(pol, tmp, list, bydst) {
522                 unsigned int h;
523
524                 __get_hash_thresh(net, pol->family, dir, &dbits, &sbits);
525                 h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
526                                 pol->family, nhashmask, dbits, sbits);
527                 if (!entry0) {
528                         hlist_del_rcu(&pol->bydst);
529                         hlist_add_head_rcu(&pol->bydst, ndsttable + h);
530                         h0 = h;
531                 } else {
532                         if (h != h0)
533                                 continue;
534                         hlist_del_rcu(&pol->bydst);
535                         hlist_add_behind_rcu(&pol->bydst, entry0);
536                 }
537                 entry0 = &pol->bydst;
538         }
539         if (!hlist_empty(list)) {
540                 entry0 = NULL;
541                 goto redo;
542         }
543 }
544
545 static void xfrm_idx_hash_transfer(struct hlist_head *list,
546                                    struct hlist_head *nidxtable,
547                                    unsigned int nhashmask)
548 {
549         struct hlist_node *tmp;
550         struct xfrm_policy *pol;
551
552         hlist_for_each_entry_safe(pol, tmp, list, byidx) {
553                 unsigned int h;
554
555                 h = __idx_hash(pol->index, nhashmask);
556                 hlist_add_head(&pol->byidx, nidxtable+h);
557         }
558 }
559
560 static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
561 {
562         return ((old_hmask + 1) << 1) - 1;
563 }
564
565 static void xfrm_bydst_resize(struct net *net, int dir)
566 {
567         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
568         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
569         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
570         struct hlist_head *ndst = xfrm_hash_alloc(nsize);
571         struct hlist_head *odst;
572         int i;
573
574         if (!ndst)
575                 return;
576
577         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
578         write_seqcount_begin(&xfrm_policy_hash_generation);
579
580         odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
581                                 lockdep_is_held(&net->xfrm.xfrm_policy_lock));
582
583         odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
584                                 lockdep_is_held(&net->xfrm.xfrm_policy_lock));
585
586         for (i = hmask; i >= 0; i--)
587                 xfrm_dst_hash_transfer(net, odst + i, ndst, nhashmask, dir);
588
589         rcu_assign_pointer(net->xfrm.policy_bydst[dir].table, ndst);
590         net->xfrm.policy_bydst[dir].hmask = nhashmask;
591
592         write_seqcount_end(&xfrm_policy_hash_generation);
593         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
594
595         synchronize_rcu();
596
597         xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
598 }
599
600 static void xfrm_byidx_resize(struct net *net, int total)
601 {
602         unsigned int hmask = net->xfrm.policy_idx_hmask;
603         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
604         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
605         struct hlist_head *oidx = net->xfrm.policy_byidx;
606         struct hlist_head *nidx = xfrm_hash_alloc(nsize);
607         int i;
608
609         if (!nidx)
610                 return;
611
612         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
613
614         for (i = hmask; i >= 0; i--)
615                 xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
616
617         net->xfrm.policy_byidx = nidx;
618         net->xfrm.policy_idx_hmask = nhashmask;
619
620         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
621
622         xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
623 }
624
625 static inline int xfrm_bydst_should_resize(struct net *net, int dir, int *total)
626 {
627         unsigned int cnt = net->xfrm.policy_count[dir];
628         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
629
630         if (total)
631                 *total += cnt;
632
633         if ((hmask + 1) < xfrm_policy_hashmax &&
634             cnt > hmask)
635                 return 1;
636
637         return 0;
638 }
639
640 static inline int xfrm_byidx_should_resize(struct net *net, int total)
641 {
642         unsigned int hmask = net->xfrm.policy_idx_hmask;
643
644         if ((hmask + 1) < xfrm_policy_hashmax &&
645             total > hmask)
646                 return 1;
647
648         return 0;
649 }
650
651 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
652 {
653         si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
654         si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
655         si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
656         si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
657         si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
658         si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
659         si->spdhcnt = net->xfrm.policy_idx_hmask;
660         si->spdhmcnt = xfrm_policy_hashmax;
661 }
662 EXPORT_SYMBOL(xfrm_spd_getinfo);
663
664 static DEFINE_MUTEX(hash_resize_mutex);
665 static void xfrm_hash_resize(struct work_struct *work)
666 {
667         struct net *net = container_of(work, struct net, xfrm.policy_hash_work);
668         int dir, total;
669
670         mutex_lock(&hash_resize_mutex);
671
672         total = 0;
673         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
674                 if (xfrm_bydst_should_resize(net, dir, &total))
675                         xfrm_bydst_resize(net, dir);
676         }
677         if (xfrm_byidx_should_resize(net, total))
678                 xfrm_byidx_resize(net, total);
679
680         mutex_unlock(&hash_resize_mutex);
681 }
682
683 /* Make sure *pol can be inserted into fastbin.
684  * Useful to check that later insert requests will be sucessful
685  * (provided xfrm_policy_lock is held throughout).
686  */
687 static struct xfrm_pol_inexact_bin *
688 xfrm_policy_inexact_alloc_bin(const struct xfrm_policy *pol, u8 dir)
689 {
690         struct xfrm_pol_inexact_bin *bin, *prev;
691         struct xfrm_pol_inexact_key k = {
692                 .family = pol->family,
693                 .type = pol->type,
694                 .dir = dir,
695                 .if_id = pol->if_id,
696         };
697         struct net *net = xp_net(pol);
698
699         lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
700
701         write_pnet(&k.net, net);
702         bin = rhashtable_lookup_fast(&xfrm_policy_inexact_table, &k,
703                                      xfrm_pol_inexact_params);
704         if (bin)
705                 return bin;
706
707         bin = kzalloc(sizeof(*bin), GFP_ATOMIC);
708         if (!bin)
709                 return NULL;
710
711         bin->k = k;
712         INIT_HLIST_HEAD(&bin->hhead);
713         bin->root_d = RB_ROOT;
714         bin->root_s = RB_ROOT;
715         seqcount_init(&bin->count);
716
717         prev = rhashtable_lookup_get_insert_key(&xfrm_policy_inexact_table,
718                                                 &bin->k, &bin->head,
719                                                 xfrm_pol_inexact_params);
720         if (!prev) {
721                 list_add(&bin->inexact_bins, &net->xfrm.inexact_bins);
722                 return bin;
723         }
724
725         kfree(bin);
726
727         return IS_ERR(prev) ? NULL : prev;
728 }
729
730 static bool xfrm_pol_inexact_addr_use_any_list(const xfrm_address_t *addr,
731                                                int family, u8 prefixlen)
732 {
733         if (xfrm_addr_any(addr, family))
734                 return true;
735
736         if (family == AF_INET6 && prefixlen < INEXACT_PREFIXLEN_IPV6)
737                 return true;
738
739         if (family == AF_INET && prefixlen < INEXACT_PREFIXLEN_IPV4)
740                 return true;
741
742         return false;
743 }
744
745 static bool
746 xfrm_policy_inexact_insert_use_any_list(const struct xfrm_policy *policy)
747 {
748         const xfrm_address_t *addr;
749         bool saddr_any, daddr_any;
750         u8 prefixlen;
751
752         addr = &policy->selector.saddr;
753         prefixlen = policy->selector.prefixlen_s;
754
755         saddr_any = xfrm_pol_inexact_addr_use_any_list(addr,
756                                                        policy->family,
757                                                        prefixlen);
758         addr = &policy->selector.daddr;
759         prefixlen = policy->selector.prefixlen_d;
760         daddr_any = xfrm_pol_inexact_addr_use_any_list(addr,
761                                                        policy->family,
762                                                        prefixlen);
763         return saddr_any && daddr_any;
764 }
765
766 static void xfrm_pol_inexact_node_init(struct xfrm_pol_inexact_node *node,
767                                        const xfrm_address_t *addr, u8 prefixlen)
768 {
769         node->addr = *addr;
770         node->prefixlen = prefixlen;
771 }
772
773 static struct xfrm_pol_inexact_node *
774 xfrm_pol_inexact_node_alloc(const xfrm_address_t *addr, u8 prefixlen)
775 {
776         struct xfrm_pol_inexact_node *node;
777
778         node = kzalloc(sizeof(*node), GFP_ATOMIC);
779         if (node)
780                 xfrm_pol_inexact_node_init(node, addr, prefixlen);
781
782         return node;
783 }
784
785 static int xfrm_policy_addr_delta(const xfrm_address_t *a,
786                                   const xfrm_address_t *b,
787                                   u8 prefixlen, u16 family)
788 {
789         unsigned int pdw, pbi;
790         int delta = 0;
791
792         switch (family) {
793         case AF_INET:
794                 if (sizeof(long) == 4 && prefixlen == 0)
795                         return ntohl(a->a4) - ntohl(b->a4);
796                 return (ntohl(a->a4) & ((~0UL << (32 - prefixlen)))) -
797                        (ntohl(b->a4) & ((~0UL << (32 - prefixlen))));
798         case AF_INET6:
799                 pdw = prefixlen >> 5;
800                 pbi = prefixlen & 0x1f;
801
802                 if (pdw) {
803                         delta = memcmp(a->a6, b->a6, pdw << 2);
804                         if (delta)
805                                 return delta;
806                 }
807                 if (pbi) {
808                         u32 mask = ~0u << (32 - pbi);
809
810                         delta = (ntohl(a->a6[pdw]) & mask) -
811                                 (ntohl(b->a6[pdw]) & mask);
812                 }
813                 break;
814         default:
815                 break;
816         }
817
818         return delta;
819 }
820
821 static void xfrm_policy_inexact_list_reinsert(struct net *net,
822                                               struct xfrm_pol_inexact_node *n,
823                                               u16 family)
824 {
825         unsigned int matched_s, matched_d;
826         struct xfrm_policy *policy, *p;
827
828         matched_s = 0;
829         matched_d = 0;
830
831         list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
832                 struct hlist_node *newpos = NULL;
833                 bool matches_s, matches_d;
834
835                 if (!policy->bydst_reinsert)
836                         continue;
837
838                 WARN_ON_ONCE(policy->family != family);
839
840                 policy->bydst_reinsert = false;
841                 hlist_for_each_entry(p, &n->hhead, bydst) {
842                         if (policy->priority > p->priority)
843                                 newpos = &p->bydst;
844                         else if (policy->priority == p->priority &&
845                                  policy->pos > p->pos)
846                                 newpos = &p->bydst;
847                         else
848                                 break;
849                 }
850
851                 if (newpos)
852                         hlist_add_behind_rcu(&policy->bydst, newpos);
853                 else
854                         hlist_add_head_rcu(&policy->bydst, &n->hhead);
855
856                 /* paranoia checks follow.
857                  * Check that the reinserted policy matches at least
858                  * saddr or daddr for current node prefix.
859                  *
860                  * Matching both is fine, matching saddr in one policy
861                  * (but not daddr) and then matching only daddr in another
862                  * is a bug.
863                  */
864                 matches_s = xfrm_policy_addr_delta(&policy->selector.saddr,
865                                                    &n->addr,
866                                                    n->prefixlen,
867                                                    family) == 0;
868                 matches_d = xfrm_policy_addr_delta(&policy->selector.daddr,
869                                                    &n->addr,
870                                                    n->prefixlen,
871                                                    family) == 0;
872                 if (matches_s && matches_d)
873                         continue;
874
875                 WARN_ON_ONCE(!matches_s && !matches_d);
876                 if (matches_s)
877                         matched_s++;
878                 if (matches_d)
879                         matched_d++;
880                 WARN_ON_ONCE(matched_s && matched_d);
881         }
882 }
883
884 static void xfrm_policy_inexact_node_reinsert(struct net *net,
885                                               struct xfrm_pol_inexact_node *n,
886                                               struct rb_root *new,
887                                               u16 family)
888 {
889         struct xfrm_pol_inexact_node *node;
890         struct rb_node **p, *parent;
891
892         /* we should not have another subtree here */
893         WARN_ON_ONCE(!RB_EMPTY_ROOT(&n->root));
894 restart:
895         parent = NULL;
896         p = &new->rb_node;
897         while (*p) {
898                 u8 prefixlen;
899                 int delta;
900
901                 parent = *p;
902                 node = rb_entry(*p, struct xfrm_pol_inexact_node, node);
903
904                 prefixlen = min(node->prefixlen, n->prefixlen);
905
906                 delta = xfrm_policy_addr_delta(&n->addr, &node->addr,
907                                                prefixlen, family);
908                 if (delta < 0) {
909                         p = &parent->rb_left;
910                 } else if (delta > 0) {
911                         p = &parent->rb_right;
912                 } else {
913                         struct xfrm_policy *tmp;
914
915                         hlist_for_each_entry(tmp, &n->hhead, bydst) {
916                                 tmp->bydst_reinsert = true;
917                                 hlist_del_rcu(&tmp->bydst);
918                         }
919
920                         xfrm_policy_inexact_list_reinsert(net, node, family);
921
922                         if (node->prefixlen == n->prefixlen) {
923                                 kfree_rcu(n, rcu);
924                                 return;
925                         }
926
927                         rb_erase(*p, new);
928                         kfree_rcu(n, rcu);
929                         n = node;
930                         n->prefixlen = prefixlen;
931                         goto restart;
932                 }
933         }
934
935         rb_link_node_rcu(&n->node, parent, p);
936         rb_insert_color(&n->node, new);
937 }
938
939 /* merge nodes v and n */
940 static void xfrm_policy_inexact_node_merge(struct net *net,
941                                            struct xfrm_pol_inexact_node *v,
942                                            struct xfrm_pol_inexact_node *n,
943                                            u16 family)
944 {
945         struct xfrm_pol_inexact_node *node;
946         struct xfrm_policy *tmp;
947         struct rb_node *rnode;
948
949         /* To-be-merged node v has a subtree.
950          *
951          * Dismantle it and insert its nodes to n->root.
952          */
953         while ((rnode = rb_first(&v->root)) != NULL) {
954                 node = rb_entry(rnode, struct xfrm_pol_inexact_node, node);
955                 rb_erase(&node->node, &v->root);
956                 xfrm_policy_inexact_node_reinsert(net, node, &n->root,
957                                                   family);
958         }
959
960         hlist_for_each_entry(tmp, &v->hhead, bydst) {
961                 tmp->bydst_reinsert = true;
962                 hlist_del_rcu(&tmp->bydst);
963         }
964
965         xfrm_policy_inexact_list_reinsert(net, n, family);
966 }
967
968 static struct xfrm_pol_inexact_node *
969 xfrm_policy_inexact_insert_node(struct net *net,
970                                 struct rb_root *root,
971                                 xfrm_address_t *addr,
972                                 u16 family, u8 prefixlen, u8 dir)
973 {
974         struct xfrm_pol_inexact_node *cached = NULL;
975         struct rb_node **p, *parent = NULL;
976         struct xfrm_pol_inexact_node *node;
977
978         p = &root->rb_node;
979         while (*p) {
980                 int delta;
981
982                 parent = *p;
983                 node = rb_entry(*p, struct xfrm_pol_inexact_node, node);
984
985                 delta = xfrm_policy_addr_delta(addr, &node->addr,
986                                                node->prefixlen,
987                                                family);
988                 if (delta == 0 && prefixlen >= node->prefixlen) {
989                         WARN_ON_ONCE(cached); /* ipsec policies got lost */
990                         return node;
991                 }
992
993                 if (delta < 0)
994                         p = &parent->rb_left;
995                 else
996                         p = &parent->rb_right;
997
998                 if (prefixlen < node->prefixlen) {
999                         delta = xfrm_policy_addr_delta(addr, &node->addr,
1000                                                        prefixlen,
1001                                                        family);
1002                         if (delta)
1003                                 continue;
1004
1005                         /* This node is a subnet of the new prefix. It needs
1006                          * to be removed and re-inserted with the smaller
1007                          * prefix and all nodes that are now also covered
1008                          * by the reduced prefixlen.
1009                          */
1010                         rb_erase(&node->node, root);
1011
1012                         if (!cached) {
1013                                 xfrm_pol_inexact_node_init(node, addr,
1014                                                            prefixlen);
1015                                 cached = node;
1016                         } else {
1017                                 /* This node also falls within the new
1018                                  * prefixlen. Merge the to-be-reinserted
1019                                  * node and this one.
1020                                  */
1021                                 xfrm_policy_inexact_node_merge(net, node,
1022                                                                cached, family);
1023                                 kfree_rcu(node, rcu);
1024                         }
1025
1026                         /* restart */
1027                         p = &root->rb_node;
1028                         parent = NULL;
1029                 }
1030         }
1031
1032         node = cached;
1033         if (!node) {
1034                 node = xfrm_pol_inexact_node_alloc(addr, prefixlen);
1035                 if (!node)
1036                         return NULL;
1037         }
1038
1039         rb_link_node_rcu(&node->node, parent, p);
1040         rb_insert_color(&node->node, root);
1041
1042         return node;
1043 }
1044
1045 static void xfrm_policy_inexact_gc_tree(struct rb_root *r, bool rm)
1046 {
1047         struct xfrm_pol_inexact_node *node;
1048         struct rb_node *rn = rb_first(r);
1049
1050         while (rn) {
1051                 node = rb_entry(rn, struct xfrm_pol_inexact_node, node);
1052
1053                 xfrm_policy_inexact_gc_tree(&node->root, rm);
1054                 rn = rb_next(rn);
1055
1056                 if (!hlist_empty(&node->hhead) || !RB_EMPTY_ROOT(&node->root)) {
1057                         WARN_ON_ONCE(rm);
1058                         continue;
1059                 }
1060
1061                 rb_erase(&node->node, r);
1062                 kfree_rcu(node, rcu);
1063         }
1064 }
1065
1066 static void __xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin *b, bool net_exit)
1067 {
1068         write_seqcount_begin(&b->count);
1069         xfrm_policy_inexact_gc_tree(&b->root_d, net_exit);
1070         xfrm_policy_inexact_gc_tree(&b->root_s, net_exit);
1071         write_seqcount_end(&b->count);
1072
1073         if (!RB_EMPTY_ROOT(&b->root_d) || !RB_EMPTY_ROOT(&b->root_s) ||
1074             !hlist_empty(&b->hhead)) {
1075                 WARN_ON_ONCE(net_exit);
1076                 return;
1077         }
1078
1079         if (rhashtable_remove_fast(&xfrm_policy_inexact_table, &b->head,
1080                                    xfrm_pol_inexact_params) == 0) {
1081                 list_del(&b->inexact_bins);
1082                 kfree_rcu(b, rcu);
1083         }
1084 }
1085
1086 static void xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin *b)
1087 {
1088         struct net *net = read_pnet(&b->k.net);
1089
1090         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1091         __xfrm_policy_inexact_prune_bin(b, false);
1092         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1093 }
1094
1095 static void __xfrm_policy_inexact_flush(struct net *net)
1096 {
1097         struct xfrm_pol_inexact_bin *bin, *t;
1098
1099         lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1100
1101         list_for_each_entry_safe(bin, t, &net->xfrm.inexact_bins, inexact_bins)
1102                 __xfrm_policy_inexact_prune_bin(bin, false);
1103 }
1104
1105 static struct hlist_head *
1106 xfrm_policy_inexact_alloc_chain(struct xfrm_pol_inexact_bin *bin,
1107                                 struct xfrm_policy *policy, u8 dir)
1108 {
1109         struct xfrm_pol_inexact_node *n;
1110         struct net *net;
1111
1112         net = xp_net(policy);
1113         lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1114
1115         if (xfrm_policy_inexact_insert_use_any_list(policy))
1116                 return &bin->hhead;
1117
1118         if (xfrm_pol_inexact_addr_use_any_list(&policy->selector.daddr,
1119                                                policy->family,
1120                                                policy->selector.prefixlen_d)) {
1121                 write_seqcount_begin(&bin->count);
1122                 n = xfrm_policy_inexact_insert_node(net,
1123                                                     &bin->root_s,
1124                                                     &policy->selector.saddr,
1125                                                     policy->family,
1126                                                     policy->selector.prefixlen_s,
1127                                                     dir);
1128                 write_seqcount_end(&bin->count);
1129                 if (!n)
1130                         return NULL;
1131
1132                 return &n->hhead;
1133         }
1134
1135         /* daddr is fixed */
1136         write_seqcount_begin(&bin->count);
1137         n = xfrm_policy_inexact_insert_node(net,
1138                                             &bin->root_d,
1139                                             &policy->selector.daddr,
1140                                             policy->family,
1141                                             policy->selector.prefixlen_d, dir);
1142         write_seqcount_end(&bin->count);
1143         if (!n)
1144                 return NULL;
1145
1146         /* saddr is wildcard */
1147         if (xfrm_pol_inexact_addr_use_any_list(&policy->selector.saddr,
1148                                                policy->family,
1149                                                policy->selector.prefixlen_s))
1150                 return &n->hhead;
1151
1152         write_seqcount_begin(&bin->count);
1153         n = xfrm_policy_inexact_insert_node(net,
1154                                             &n->root,
1155                                             &policy->selector.saddr,
1156                                             policy->family,
1157                                             policy->selector.prefixlen_s, dir);
1158         write_seqcount_end(&bin->count);
1159         if (!n)
1160                 return NULL;
1161
1162         return &n->hhead;
1163 }
1164
1165 static struct xfrm_policy *
1166 xfrm_policy_inexact_insert(struct xfrm_policy *policy, u8 dir, int excl)
1167 {
1168         struct xfrm_pol_inexact_bin *bin;
1169         struct xfrm_policy *delpol;
1170         struct hlist_head *chain;
1171         struct net *net;
1172
1173         bin = xfrm_policy_inexact_alloc_bin(policy, dir);
1174         if (!bin)
1175                 return ERR_PTR(-ENOMEM);
1176
1177         net = xp_net(policy);
1178         lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1179
1180         chain = xfrm_policy_inexact_alloc_chain(bin, policy, dir);
1181         if (!chain) {
1182                 __xfrm_policy_inexact_prune_bin(bin, false);
1183                 return ERR_PTR(-ENOMEM);
1184         }
1185
1186         delpol = xfrm_policy_insert_list(chain, policy, excl);
1187         if (delpol && excl) {
1188                 __xfrm_policy_inexact_prune_bin(bin, false);
1189                 return ERR_PTR(-EEXIST);
1190         }
1191
1192         chain = &net->xfrm.policy_inexact[dir];
1193         xfrm_policy_insert_inexact_list(chain, policy);
1194
1195         if (delpol)
1196                 __xfrm_policy_inexact_prune_bin(bin, false);
1197
1198         return delpol;
1199 }
1200
1201 static void xfrm_hash_rebuild(struct work_struct *work)
1202 {
1203         struct net *net = container_of(work, struct net,
1204                                        xfrm.policy_hthresh.work);
1205         unsigned int hmask;
1206         struct xfrm_policy *pol;
1207         struct xfrm_policy *policy;
1208         struct hlist_head *chain;
1209         struct hlist_head *odst;
1210         struct hlist_node *newpos;
1211         int i;
1212         int dir;
1213         unsigned seq;
1214         u8 lbits4, rbits4, lbits6, rbits6;
1215
1216         mutex_lock(&hash_resize_mutex);
1217
1218         /* read selector prefixlen thresholds */
1219         do {
1220                 seq = read_seqbegin(&net->xfrm.policy_hthresh.lock);
1221
1222                 lbits4 = net->xfrm.policy_hthresh.lbits4;
1223                 rbits4 = net->xfrm.policy_hthresh.rbits4;
1224                 lbits6 = net->xfrm.policy_hthresh.lbits6;
1225                 rbits6 = net->xfrm.policy_hthresh.rbits6;
1226         } while (read_seqretry(&net->xfrm.policy_hthresh.lock, seq));
1227
1228         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1229         write_seqcount_begin(&xfrm_policy_hash_generation);
1230
1231         /* make sure that we can insert the indirect policies again before
1232          * we start with destructive action.
1233          */
1234         list_for_each_entry(policy, &net->xfrm.policy_all, walk.all) {
1235                 struct xfrm_pol_inexact_bin *bin;
1236                 u8 dbits, sbits;
1237
1238                 dir = xfrm_policy_id2dir(policy->index);
1239                 if (policy->walk.dead || dir >= XFRM_POLICY_MAX)
1240                         continue;
1241
1242                 if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
1243                         if (policy->family == AF_INET) {
1244                                 dbits = rbits4;
1245                                 sbits = lbits4;
1246                         } else {
1247                                 dbits = rbits6;
1248                                 sbits = lbits6;
1249                         }
1250                 } else {
1251                         if (policy->family == AF_INET) {
1252                                 dbits = lbits4;
1253                                 sbits = rbits4;
1254                         } else {
1255                                 dbits = lbits6;
1256                                 sbits = rbits6;
1257                         }
1258                 }
1259
1260                 if (policy->selector.prefixlen_d < dbits ||
1261                     policy->selector.prefixlen_s < sbits)
1262                         continue;
1263
1264                 bin = xfrm_policy_inexact_alloc_bin(policy, dir);
1265                 if (!bin)
1266                         goto out_unlock;
1267
1268                 if (!xfrm_policy_inexact_alloc_chain(bin, policy, dir))
1269                         goto out_unlock;
1270         }
1271
1272         /* reset the bydst and inexact table in all directions */
1273         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
1274                 struct hlist_node *n;
1275
1276                 hlist_for_each_entry_safe(policy, n,
1277                                           &net->xfrm.policy_inexact[dir],
1278                                           bydst_inexact_list)
1279                         hlist_del_init(&policy->bydst_inexact_list);
1280
1281                 hmask = net->xfrm.policy_bydst[dir].hmask;
1282                 odst = net->xfrm.policy_bydst[dir].table;
1283                 for (i = hmask; i >= 0; i--)
1284                         INIT_HLIST_HEAD(odst + i);
1285                 if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
1286                         /* dir out => dst = remote, src = local */
1287                         net->xfrm.policy_bydst[dir].dbits4 = rbits4;
1288                         net->xfrm.policy_bydst[dir].sbits4 = lbits4;
1289                         net->xfrm.policy_bydst[dir].dbits6 = rbits6;
1290                         net->xfrm.policy_bydst[dir].sbits6 = lbits6;
1291                 } else {
1292                         /* dir in/fwd => dst = local, src = remote */
1293                         net->xfrm.policy_bydst[dir].dbits4 = lbits4;
1294                         net->xfrm.policy_bydst[dir].sbits4 = rbits4;
1295                         net->xfrm.policy_bydst[dir].dbits6 = lbits6;
1296                         net->xfrm.policy_bydst[dir].sbits6 = rbits6;
1297                 }
1298         }
1299
1300         /* re-insert all policies by order of creation */
1301         list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
1302                 if (policy->walk.dead)
1303                         continue;
1304                 dir = xfrm_policy_id2dir(policy->index);
1305                 if (dir >= XFRM_POLICY_MAX) {
1306                         /* skip socket policies */
1307                         continue;
1308                 }
1309                 newpos = NULL;
1310                 chain = policy_hash_bysel(net, &policy->selector,
1311                                           policy->family, dir);
1312
1313                 hlist_del_rcu(&policy->bydst);
1314
1315                 if (!chain) {
1316                         void *p = xfrm_policy_inexact_insert(policy, dir, 0);
1317
1318                         WARN_ONCE(IS_ERR(p), "reinsert: %ld\n", PTR_ERR(p));
1319                         continue;
1320                 }
1321
1322                 hlist_for_each_entry(pol, chain, bydst) {
1323                         if (policy->priority >= pol->priority)
1324                                 newpos = &pol->bydst;
1325                         else
1326                                 break;
1327                 }
1328                 if (newpos)
1329                         hlist_add_behind_rcu(&policy->bydst, newpos);
1330                 else
1331                         hlist_add_head_rcu(&policy->bydst, chain);
1332         }
1333
1334 out_unlock:
1335         __xfrm_policy_inexact_flush(net);
1336         write_seqcount_end(&xfrm_policy_hash_generation);
1337         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1338
1339         mutex_unlock(&hash_resize_mutex);
1340 }
1341
1342 void xfrm_policy_hash_rebuild(struct net *net)
1343 {
1344         schedule_work(&net->xfrm.policy_hthresh.work);
1345 }
1346 EXPORT_SYMBOL(xfrm_policy_hash_rebuild);
1347
1348 /* Generate new index... KAME seems to generate them ordered by cost
1349  * of an absolute inpredictability of ordering of rules. This will not pass. */
1350 static u32 xfrm_gen_index(struct net *net, int dir, u32 index)
1351 {
1352         static u32 idx_generator;
1353
1354         for (;;) {
1355                 struct hlist_head *list;
1356                 struct xfrm_policy *p;
1357                 u32 idx;
1358                 int found;
1359
1360                 if (!index) {
1361                         idx = (idx_generator | dir);
1362                         idx_generator += 8;
1363                 } else {
1364                         idx = index;
1365                         index = 0;
1366                 }
1367
1368                 if (idx == 0)
1369                         idx = 8;
1370                 list = net->xfrm.policy_byidx + idx_hash(net, idx);
1371                 found = 0;
1372                 hlist_for_each_entry(p, list, byidx) {
1373                         if (p->index == idx) {
1374                                 found = 1;
1375                                 break;
1376                         }
1377                 }
1378                 if (!found)
1379                         return idx;
1380         }
1381 }
1382
1383 static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
1384 {
1385         u32 *p1 = (u32 *) s1;
1386         u32 *p2 = (u32 *) s2;
1387         int len = sizeof(struct xfrm_selector) / sizeof(u32);
1388         int i;
1389
1390         for (i = 0; i < len; i++) {
1391                 if (p1[i] != p2[i])
1392                         return 1;
1393         }
1394
1395         return 0;
1396 }
1397
1398 static void xfrm_policy_requeue(struct xfrm_policy *old,
1399                                 struct xfrm_policy *new)
1400 {
1401         struct xfrm_policy_queue *pq = &old->polq;
1402         struct sk_buff_head list;
1403
1404         if (skb_queue_empty(&pq->hold_queue))
1405                 return;
1406
1407         __skb_queue_head_init(&list);
1408
1409         spin_lock_bh(&pq->hold_queue.lock);
1410         skb_queue_splice_init(&pq->hold_queue, &list);
1411         if (del_timer(&pq->hold_timer))
1412                 xfrm_pol_put(old);
1413         spin_unlock_bh(&pq->hold_queue.lock);
1414
1415         pq = &new->polq;
1416
1417         spin_lock_bh(&pq->hold_queue.lock);
1418         skb_queue_splice(&list, &pq->hold_queue);
1419         pq->timeout = XFRM_QUEUE_TMO_MIN;
1420         if (!mod_timer(&pq->hold_timer, jiffies))
1421                 xfrm_pol_hold(new);
1422         spin_unlock_bh(&pq->hold_queue.lock);
1423 }
1424
1425 static bool xfrm_policy_mark_match(struct xfrm_policy *policy,
1426                                    struct xfrm_policy *pol)
1427 {
1428         u32 mark = policy->mark.v & policy->mark.m;
1429
1430         if (policy->mark.v == pol->mark.v && policy->mark.m == pol->mark.m)
1431                 return true;
1432
1433         if ((mark & pol->mark.m) == pol->mark.v &&
1434             policy->priority == pol->priority)
1435                 return true;
1436
1437         return false;
1438 }
1439
1440 static u32 xfrm_pol_bin_key(const void *data, u32 len, u32 seed)
1441 {
1442         const struct xfrm_pol_inexact_key *k = data;
1443         u32 a = k->type << 24 | k->dir << 16 | k->family;
1444
1445         return jhash_3words(a, k->if_id, net_hash_mix(read_pnet(&k->net)),
1446                             seed);
1447 }
1448
1449 static u32 xfrm_pol_bin_obj(const void *data, u32 len, u32 seed)
1450 {
1451         const struct xfrm_pol_inexact_bin *b = data;
1452
1453         return xfrm_pol_bin_key(&b->k, 0, seed);
1454 }
1455
1456 static int xfrm_pol_bin_cmp(struct rhashtable_compare_arg *arg,
1457                             const void *ptr)
1458 {
1459         const struct xfrm_pol_inexact_key *key = arg->key;
1460         const struct xfrm_pol_inexact_bin *b = ptr;
1461         int ret;
1462
1463         if (!net_eq(read_pnet(&b->k.net), read_pnet(&key->net)))
1464                 return -1;
1465
1466         ret = b->k.dir ^ key->dir;
1467         if (ret)
1468                 return ret;
1469
1470         ret = b->k.type ^ key->type;
1471         if (ret)
1472                 return ret;
1473
1474         ret = b->k.family ^ key->family;
1475         if (ret)
1476                 return ret;
1477
1478         return b->k.if_id ^ key->if_id;
1479 }
1480
1481 static const struct rhashtable_params xfrm_pol_inexact_params = {
1482         .head_offset            = offsetof(struct xfrm_pol_inexact_bin, head),
1483         .hashfn                 = xfrm_pol_bin_key,
1484         .obj_hashfn             = xfrm_pol_bin_obj,
1485         .obj_cmpfn              = xfrm_pol_bin_cmp,
1486         .automatic_shrinking    = true,
1487 };
1488
1489 static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
1490                                             struct xfrm_policy *policy)
1491 {
1492         struct xfrm_policy *pol, *delpol = NULL;
1493         struct hlist_node *newpos = NULL;
1494         int i = 0;
1495
1496         hlist_for_each_entry(pol, chain, bydst_inexact_list) {
1497                 if (pol->type == policy->type &&
1498                     pol->if_id == policy->if_id &&
1499                     !selector_cmp(&pol->selector, &policy->selector) &&
1500                     xfrm_policy_mark_match(policy, pol) &&
1501                     xfrm_sec_ctx_match(pol->security, policy->security) &&
1502                     !WARN_ON(delpol)) {
1503                         delpol = pol;
1504                         if (policy->priority > pol->priority)
1505                                 continue;
1506                 } else if (policy->priority >= pol->priority) {
1507                         newpos = &pol->bydst_inexact_list;
1508                         continue;
1509                 }
1510                 if (delpol)
1511                         break;
1512         }
1513
1514         if (newpos)
1515                 hlist_add_behind_rcu(&policy->bydst_inexact_list, newpos);
1516         else
1517                 hlist_add_head_rcu(&policy->bydst_inexact_list, chain);
1518
1519         hlist_for_each_entry(pol, chain, bydst_inexact_list) {
1520                 pol->pos = i;
1521                 i++;
1522         }
1523 }
1524
1525 static struct xfrm_policy *xfrm_policy_insert_list(struct hlist_head *chain,
1526                                                    struct xfrm_policy *policy,
1527                                                    bool excl)
1528 {
1529         struct xfrm_policy *pol, *newpos = NULL, *delpol = NULL;
1530
1531         hlist_for_each_entry(pol, chain, bydst) {
1532                 if (pol->type == policy->type &&
1533                     pol->if_id == policy->if_id &&
1534                     !selector_cmp(&pol->selector, &policy->selector) &&
1535                     xfrm_policy_mark_match(policy, pol) &&
1536                     xfrm_sec_ctx_match(pol->security, policy->security) &&
1537                     !WARN_ON(delpol)) {
1538                         if (excl)
1539                                 return ERR_PTR(-EEXIST);
1540                         delpol = pol;
1541                         if (policy->priority > pol->priority)
1542                                 continue;
1543                 } else if (policy->priority >= pol->priority) {
1544                         newpos = pol;
1545                         continue;
1546                 }
1547                 if (delpol)
1548                         break;
1549         }
1550
1551         if (newpos)
1552                 hlist_add_behind_rcu(&policy->bydst, &newpos->bydst);
1553         else
1554                 hlist_add_head_rcu(&policy->bydst, chain);
1555
1556         return delpol;
1557 }
1558
1559 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
1560 {
1561         struct net *net = xp_net(policy);
1562         struct xfrm_policy *delpol;
1563         struct hlist_head *chain;
1564
1565         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1566         chain = policy_hash_bysel(net, &policy->selector, policy->family, dir);
1567         if (chain)
1568                 delpol = xfrm_policy_insert_list(chain, policy, excl);
1569         else
1570                 delpol = xfrm_policy_inexact_insert(policy, dir, excl);
1571
1572         if (IS_ERR(delpol)) {
1573                 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1574                 return PTR_ERR(delpol);
1575         }
1576
1577         __xfrm_policy_link(policy, dir);
1578
1579         /* After previous checking, family can either be AF_INET or AF_INET6 */
1580         if (policy->family == AF_INET)
1581                 rt_genid_bump_ipv4(net);
1582         else
1583                 rt_genid_bump_ipv6(net);
1584
1585         if (delpol) {
1586                 xfrm_policy_requeue(delpol, policy);
1587                 __xfrm_policy_unlink(delpol, dir);
1588         }
1589         policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir, policy->index);
1590         hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
1591         policy->curlft.add_time = ktime_get_real_seconds();
1592         policy->curlft.use_time = 0;
1593         if (!mod_timer(&policy->timer, jiffies + HZ))
1594                 xfrm_pol_hold(policy);
1595         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1596
1597         if (delpol)
1598                 xfrm_policy_kill(delpol);
1599         else if (xfrm_bydst_should_resize(net, dir, NULL))
1600                 schedule_work(&net->xfrm.policy_hash_work);
1601
1602         return 0;
1603 }
1604 EXPORT_SYMBOL(xfrm_policy_insert);
1605
1606 static struct xfrm_policy *
1607 __xfrm_policy_bysel_ctx(struct hlist_head *chain, u32 mark, u32 if_id,
1608                         u8 type, int dir,
1609                         struct xfrm_selector *sel,
1610                         struct xfrm_sec_ctx *ctx)
1611 {
1612         struct xfrm_policy *pol;
1613
1614         if (!chain)
1615                 return NULL;
1616
1617         hlist_for_each_entry(pol, chain, bydst) {
1618                 if (pol->type == type &&
1619                     pol->if_id == if_id &&
1620                     (mark & pol->mark.m) == pol->mark.v &&
1621                     !selector_cmp(sel, &pol->selector) &&
1622                     xfrm_sec_ctx_match(ctx, pol->security))
1623                         return pol;
1624         }
1625
1626         return NULL;
1627 }
1628
1629 struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u32 if_id,
1630                                           u8 type, int dir,
1631                                           struct xfrm_selector *sel,
1632                                           struct xfrm_sec_ctx *ctx, int delete,
1633                                           int *err)
1634 {
1635         struct xfrm_pol_inexact_bin *bin = NULL;
1636         struct xfrm_policy *pol, *ret = NULL;
1637         struct hlist_head *chain;
1638
1639         *err = 0;
1640         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1641         chain = policy_hash_bysel(net, sel, sel->family, dir);
1642         if (!chain) {
1643                 struct xfrm_pol_inexact_candidates cand;
1644                 int i;
1645
1646                 bin = xfrm_policy_inexact_lookup(net, type,
1647                                                  sel->family, dir, if_id);
1648                 if (!bin) {
1649                         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1650                         return NULL;
1651                 }
1652
1653                 if (!xfrm_policy_find_inexact_candidates(&cand, bin,
1654                                                          &sel->saddr,
1655                                                          &sel->daddr)) {
1656                         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1657                         return NULL;
1658                 }
1659
1660                 pol = NULL;
1661                 for (i = 0; i < ARRAY_SIZE(cand.res); i++) {
1662                         struct xfrm_policy *tmp;
1663
1664                         tmp = __xfrm_policy_bysel_ctx(cand.res[i], mark,
1665                                                       if_id, type, dir,
1666                                                       sel, ctx);
1667                         if (!tmp)
1668                                 continue;
1669
1670                         if (!pol || tmp->pos < pol->pos)
1671                                 pol = tmp;
1672                 }
1673         } else {
1674                 pol = __xfrm_policy_bysel_ctx(chain, mark, if_id, type, dir,
1675                                               sel, ctx);
1676         }
1677
1678         if (pol) {
1679                 xfrm_pol_hold(pol);
1680                 if (delete) {
1681                         *err = security_xfrm_policy_delete(pol->security);
1682                         if (*err) {
1683                                 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1684                                 return pol;
1685                         }
1686                         __xfrm_policy_unlink(pol, dir);
1687                 }
1688                 ret = pol;
1689         }
1690         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1691
1692         if (ret && delete)
1693                 xfrm_policy_kill(ret);
1694         if (bin && delete)
1695                 xfrm_policy_inexact_prune_bin(bin);
1696         return ret;
1697 }
1698 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
1699
1700 struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u32 if_id,
1701                                      u8 type, int dir, u32 id, int delete,
1702                                      int *err)
1703 {
1704         struct xfrm_policy *pol, *ret;
1705         struct hlist_head *chain;
1706
1707         *err = -ENOENT;
1708         if (xfrm_policy_id2dir(id) != dir)
1709                 return NULL;
1710
1711         *err = 0;
1712         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1713         chain = net->xfrm.policy_byidx + idx_hash(net, id);
1714         ret = NULL;
1715         hlist_for_each_entry(pol, chain, byidx) {
1716                 if (pol->type == type && pol->index == id &&
1717                     pol->if_id == if_id &&
1718                     (mark & pol->mark.m) == pol->mark.v) {
1719                         xfrm_pol_hold(pol);
1720                         if (delete) {
1721                                 *err = security_xfrm_policy_delete(
1722                                                                 pol->security);
1723                                 if (*err) {
1724                                         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1725                                         return pol;
1726                                 }
1727                                 __xfrm_policy_unlink(pol, dir);
1728                         }
1729                         ret = pol;
1730                         break;
1731                 }
1732         }
1733         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1734
1735         if (ret && delete)
1736                 xfrm_policy_kill(ret);
1737         return ret;
1738 }
1739 EXPORT_SYMBOL(xfrm_policy_byid);
1740
1741 #ifdef CONFIG_SECURITY_NETWORK_XFRM
1742 static inline int
1743 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
1744 {
1745         struct xfrm_policy *pol;
1746         int err = 0;
1747
1748         list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
1749                 if (pol->walk.dead ||
1750                     xfrm_policy_id2dir(pol->index) >= XFRM_POLICY_MAX ||
1751                     pol->type != type)
1752                         continue;
1753
1754                 err = security_xfrm_policy_delete(pol->security);
1755                 if (err) {
1756                         xfrm_audit_policy_delete(pol, 0, task_valid);
1757                         return err;
1758                 }
1759         }
1760         return err;
1761 }
1762 #else
1763 static inline int
1764 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
1765 {
1766         return 0;
1767 }
1768 #endif
1769
1770 int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
1771 {
1772         int dir, err = 0, cnt = 0;
1773         struct xfrm_policy *pol;
1774
1775         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1776
1777         err = xfrm_policy_flush_secctx_check(net, type, task_valid);
1778         if (err)
1779                 goto out;
1780
1781 again:
1782         list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
1783                 dir = xfrm_policy_id2dir(pol->index);
1784                 if (pol->walk.dead ||
1785                     dir >= XFRM_POLICY_MAX ||
1786                     pol->type != type)
1787                         continue;
1788
1789                 __xfrm_policy_unlink(pol, dir);
1790                 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1791                 cnt++;
1792                 xfrm_audit_policy_delete(pol, 1, task_valid);
1793                 xfrm_policy_kill(pol);
1794                 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1795                 goto again;
1796         }
1797         if (cnt)
1798                 __xfrm_policy_inexact_flush(net);
1799         else
1800                 err = -ESRCH;
1801 out:
1802         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1803         return err;
1804 }
1805 EXPORT_SYMBOL(xfrm_policy_flush);
1806
1807 int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
1808                      int (*func)(struct xfrm_policy *, int, int, void*),
1809                      void *data)
1810 {
1811         struct xfrm_policy *pol;
1812         struct xfrm_policy_walk_entry *x;
1813         int error = 0;
1814
1815         if (walk->type >= XFRM_POLICY_TYPE_MAX &&
1816             walk->type != XFRM_POLICY_TYPE_ANY)
1817                 return -EINVAL;
1818
1819         if (list_empty(&walk->walk.all) && walk->seq != 0)
1820                 return 0;
1821
1822         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1823         if (list_empty(&walk->walk.all))
1824                 x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
1825         else
1826                 x = list_first_entry(&walk->walk.all,
1827                                      struct xfrm_policy_walk_entry, all);
1828
1829         list_for_each_entry_from(x, &net->xfrm.policy_all, all) {
1830                 if (x->dead)
1831                         continue;
1832                 pol = container_of(x, struct xfrm_policy, walk);
1833                 if (walk->type != XFRM_POLICY_TYPE_ANY &&
1834                     walk->type != pol->type)
1835                         continue;
1836                 error = func(pol, xfrm_policy_id2dir(pol->index),
1837                              walk->seq, data);
1838                 if (error) {
1839                         list_move_tail(&walk->walk.all, &x->all);
1840                         goto out;
1841                 }
1842                 walk->seq++;
1843         }
1844         if (walk->seq == 0) {
1845                 error = -ENOENT;
1846                 goto out;
1847         }
1848         list_del_init(&walk->walk.all);
1849 out:
1850         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1851         return error;
1852 }
1853 EXPORT_SYMBOL(xfrm_policy_walk);
1854
1855 void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type)
1856 {
1857         INIT_LIST_HEAD(&walk->walk.all);
1858         walk->walk.dead = 1;
1859         walk->type = type;
1860         walk->seq = 0;
1861 }
1862 EXPORT_SYMBOL(xfrm_policy_walk_init);
1863
1864 void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net)
1865 {
1866         if (list_empty(&walk->walk.all))
1867                 return;
1868
1869         spin_lock_bh(&net->xfrm.xfrm_policy_lock); /*FIXME where is net? */
1870         list_del(&walk->walk.all);
1871         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1872 }
1873 EXPORT_SYMBOL(xfrm_policy_walk_done);
1874
1875 /*
1876  * Find policy to apply to this flow.
1877  *
1878  * Returns 0 if policy found, else an -errno.
1879  */
1880 static int xfrm_policy_match(const struct xfrm_policy *pol,
1881                              const struct flowi *fl,
1882                              u8 type, u16 family, int dir, u32 if_id)
1883 {
1884         const struct xfrm_selector *sel = &pol->selector;
1885         int ret = -ESRCH;
1886         bool match;
1887
1888         if (pol->family != family ||
1889             pol->if_id != if_id ||
1890             (fl->flowi_mark & pol->mark.m) != pol->mark.v ||
1891             pol->type != type)
1892                 return ret;
1893
1894         match = xfrm_selector_match(sel, fl, family);
1895         if (match)
1896                 ret = security_xfrm_policy_lookup(pol->security, fl->flowi_secid,
1897                                                   dir);
1898         return ret;
1899 }
1900
1901 static struct xfrm_pol_inexact_node *
1902 xfrm_policy_lookup_inexact_addr(const struct rb_root *r,
1903                                 seqcount_t *count,
1904                                 const xfrm_address_t *addr, u16 family)
1905 {
1906         const struct rb_node *parent;
1907         int seq;
1908
1909 again:
1910         seq = read_seqcount_begin(count);
1911
1912         parent = rcu_dereference_raw(r->rb_node);
1913         while (parent) {
1914                 struct xfrm_pol_inexact_node *node;
1915                 int delta;
1916
1917                 node = rb_entry(parent, struct xfrm_pol_inexact_node, node);
1918
1919                 delta = xfrm_policy_addr_delta(addr, &node->addr,
1920                                                node->prefixlen, family);
1921                 if (delta < 0) {
1922                         parent = rcu_dereference_raw(parent->rb_left);
1923                         continue;
1924                 } else if (delta > 0) {
1925                         parent = rcu_dereference_raw(parent->rb_right);
1926                         continue;
1927                 }
1928
1929                 return node;
1930         }
1931
1932         if (read_seqcount_retry(count, seq))
1933                 goto again;
1934
1935         return NULL;
1936 }
1937
1938 static bool
1939 xfrm_policy_find_inexact_candidates(struct xfrm_pol_inexact_candidates *cand,
1940                                     struct xfrm_pol_inexact_bin *b,
1941                                     const xfrm_address_t *saddr,
1942                                     const xfrm_address_t *daddr)
1943 {
1944         struct xfrm_pol_inexact_node *n;
1945         u16 family;
1946
1947         if (!b)
1948                 return false;
1949
1950         family = b->k.family;
1951         memset(cand, 0, sizeof(*cand));
1952         cand->res[XFRM_POL_CAND_ANY] = &b->hhead;
1953
1954         n = xfrm_policy_lookup_inexact_addr(&b->root_d, &b->count, daddr,
1955                                             family);
1956         if (n) {
1957                 cand->res[XFRM_POL_CAND_DADDR] = &n->hhead;
1958                 n = xfrm_policy_lookup_inexact_addr(&n->root, &b->count, saddr,
1959                                                     family);
1960                 if (n)
1961                         cand->res[XFRM_POL_CAND_BOTH] = &n->hhead;
1962         }
1963
1964         n = xfrm_policy_lookup_inexact_addr(&b->root_s, &b->count, saddr,
1965                                             family);
1966         if (n)
1967                 cand->res[XFRM_POL_CAND_SADDR] = &n->hhead;
1968
1969         return true;
1970 }
1971
1972 static struct xfrm_pol_inexact_bin *
1973 xfrm_policy_inexact_lookup_rcu(struct net *net, u8 type, u16 family,
1974                                u8 dir, u32 if_id)
1975 {
1976         struct xfrm_pol_inexact_key k = {
1977                 .family = family,
1978                 .type = type,
1979                 .dir = dir,
1980                 .if_id = if_id,
1981         };
1982
1983         write_pnet(&k.net, net);
1984
1985         return rhashtable_lookup(&xfrm_policy_inexact_table, &k,
1986                                  xfrm_pol_inexact_params);
1987 }
1988
1989 static struct xfrm_pol_inexact_bin *
1990 xfrm_policy_inexact_lookup(struct net *net, u8 type, u16 family,
1991                            u8 dir, u32 if_id)
1992 {
1993         struct xfrm_pol_inexact_bin *bin;
1994
1995         lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1996
1997         rcu_read_lock();
1998         bin = xfrm_policy_inexact_lookup_rcu(net, type, family, dir, if_id);
1999         rcu_read_unlock();
2000
2001         return bin;
2002 }
2003
2004 static struct xfrm_policy *
2005 __xfrm_policy_eval_candidates(struct hlist_head *chain,
2006                               struct xfrm_policy *prefer,
2007                               const struct flowi *fl,
2008                               u8 type, u16 family, int dir, u32 if_id)
2009 {
2010         u32 priority = prefer ? prefer->priority : ~0u;
2011         struct xfrm_policy *pol;
2012
2013         if (!chain)
2014                 return NULL;
2015
2016         hlist_for_each_entry_rcu(pol, chain, bydst) {
2017                 int err;
2018
2019                 if (pol->priority > priority)
2020                         break;
2021
2022                 err = xfrm_policy_match(pol, fl, type, family, dir, if_id);
2023                 if (err) {
2024                         if (err != -ESRCH)
2025                                 return ERR_PTR(err);
2026
2027                         continue;
2028                 }
2029
2030                 if (prefer) {
2031                         /* matches.  Is it older than *prefer? */
2032                         if (pol->priority == priority &&
2033                             prefer->pos < pol->pos)
2034                                 return prefer;
2035                 }
2036
2037                 return pol;
2038         }
2039
2040         return NULL;
2041 }
2042
2043 static struct xfrm_policy *
2044 xfrm_policy_eval_candidates(struct xfrm_pol_inexact_candidates *cand,
2045                             struct xfrm_policy *prefer,
2046                             const struct flowi *fl,
2047                             u8 type, u16 family, int dir, u32 if_id)
2048 {
2049         struct xfrm_policy *tmp;
2050         int i;
2051
2052         for (i = 0; i < ARRAY_SIZE(cand->res); i++) {
2053                 tmp = __xfrm_policy_eval_candidates(cand->res[i],
2054                                                     prefer,
2055                                                     fl, type, family, dir,
2056                                                     if_id);
2057                 if (!tmp)
2058                         continue;
2059
2060                 if (IS_ERR(tmp))
2061                         return tmp;
2062                 prefer = tmp;
2063         }
2064
2065         return prefer;
2066 }
2067
2068 static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
2069                                                      const struct flowi *fl,
2070                                                      u16 family, u8 dir,
2071                                                      u32 if_id)
2072 {
2073         struct xfrm_pol_inexact_candidates cand;
2074         const xfrm_address_t *daddr, *saddr;
2075         struct xfrm_pol_inexact_bin *bin;
2076         struct xfrm_policy *pol, *ret;
2077         struct hlist_head *chain;
2078         unsigned int sequence;
2079         int err;
2080
2081         daddr = xfrm_flowi_daddr(fl, family);
2082         saddr = xfrm_flowi_saddr(fl, family);
2083         if (unlikely(!daddr || !saddr))
2084                 return NULL;
2085
2086         rcu_read_lock();
2087  retry:
2088         do {
2089                 sequence = read_seqcount_begin(&xfrm_policy_hash_generation);
2090                 chain = policy_hash_direct(net, daddr, saddr, family, dir);
2091         } while (read_seqcount_retry(&xfrm_policy_hash_generation, sequence));
2092
2093         ret = NULL;
2094         hlist_for_each_entry_rcu(pol, chain, bydst) {
2095                 err = xfrm_policy_match(pol, fl, type, family, dir, if_id);
2096                 if (err) {
2097                         if (err == -ESRCH)
2098                                 continue;
2099                         else {
2100                                 ret = ERR_PTR(err);
2101                                 goto fail;
2102                         }
2103                 } else {
2104                         ret = pol;
2105                         break;
2106                 }
2107         }
2108         bin = xfrm_policy_inexact_lookup_rcu(net, type, family, dir, if_id);
2109         if (!bin || !xfrm_policy_find_inexact_candidates(&cand, bin, saddr,
2110                                                          daddr))
2111                 goto skip_inexact;
2112
2113         pol = xfrm_policy_eval_candidates(&cand, ret, fl, type,
2114                                           family, dir, if_id);
2115         if (pol) {
2116                 ret = pol;
2117                 if (IS_ERR(pol))
2118                         goto fail;
2119         }
2120
2121 skip_inexact:
2122         if (read_seqcount_retry(&xfrm_policy_hash_generation, sequence))
2123                 goto retry;
2124
2125         if (ret && !xfrm_pol_hold_rcu(ret))
2126                 goto retry;
2127 fail:
2128         rcu_read_unlock();
2129
2130         return ret;
2131 }
2132
2133 static struct xfrm_policy *xfrm_policy_lookup(struct net *net,
2134                                               const struct flowi *fl,
2135                                               u16 family, u8 dir, u32 if_id)
2136 {
2137 #ifdef CONFIG_XFRM_SUB_POLICY
2138         struct xfrm_policy *pol;
2139
2140         pol = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_SUB, fl, family,
2141                                         dir, if_id);
2142         if (pol != NULL)
2143                 return pol;
2144 #endif
2145         return xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, fl, family,
2146                                          dir, if_id);
2147 }
2148
2149 static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir,
2150                                                  const struct flowi *fl,
2151                                                  u16 family, u32 if_id)
2152 {
2153         struct xfrm_policy *pol;
2154
2155         rcu_read_lock();
2156  again:
2157         pol = rcu_dereference(sk->sk_policy[dir]);
2158         if (pol != NULL) {
2159                 bool match;
2160                 int err = 0;
2161
2162                 if (pol->family != family) {
2163                         pol = NULL;
2164                         goto out;
2165                 }
2166
2167                 match = xfrm_selector_match(&pol->selector, fl, family);
2168                 if (match) {
2169                         if ((sk->sk_mark & pol->mark.m) != pol->mark.v ||
2170                             pol->if_id != if_id) {
2171                                 pol = NULL;
2172                                 goto out;
2173                         }
2174                         err = security_xfrm_policy_lookup(pol->security,
2175                                                       fl->flowi_secid,
2176                                                       dir);
2177                         if (!err) {
2178                                 if (!xfrm_pol_hold_rcu(pol))
2179                                         goto again;
2180                         } else if (err == -ESRCH) {
2181                                 pol = NULL;
2182                         } else {
2183                                 pol = ERR_PTR(err);
2184                         }
2185                 } else
2186                         pol = NULL;
2187         }
2188 out:
2189         rcu_read_unlock();
2190         return pol;
2191 }
2192
2193 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
2194 {
2195         struct net *net = xp_net(pol);
2196
2197         list_add(&pol->walk.all, &net->xfrm.policy_all);
2198         net->xfrm.policy_count[dir]++;
2199         xfrm_pol_hold(pol);
2200 }
2201
2202 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
2203                                                 int dir)
2204 {
2205         struct net *net = xp_net(pol);
2206
2207         if (list_empty(&pol->walk.all))
2208                 return NULL;
2209
2210         /* Socket policies are not hashed. */
2211         if (!hlist_unhashed(&pol->bydst)) {
2212                 hlist_del_rcu(&pol->bydst);
2213                 hlist_del_init(&pol->bydst_inexact_list);
2214                 hlist_del(&pol->byidx);
2215         }
2216
2217         list_del_init(&pol->walk.all);
2218         net->xfrm.policy_count[dir]--;
2219
2220         return pol;
2221 }
2222
2223 static void xfrm_sk_policy_link(struct xfrm_policy *pol, int dir)
2224 {
2225         __xfrm_policy_link(pol, XFRM_POLICY_MAX + dir);
2226 }
2227
2228 static void xfrm_sk_policy_unlink(struct xfrm_policy *pol, int dir)
2229 {
2230         __xfrm_policy_unlink(pol, XFRM_POLICY_MAX + dir);
2231 }
2232
2233 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
2234 {
2235         struct net *net = xp_net(pol);
2236
2237         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2238         pol = __xfrm_policy_unlink(pol, dir);
2239         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2240         if (pol) {
2241                 xfrm_policy_kill(pol);
2242                 return 0;
2243         }
2244         return -ENOENT;
2245 }
2246 EXPORT_SYMBOL(xfrm_policy_delete);
2247
2248 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
2249 {
2250         struct net *net = sock_net(sk);
2251         struct xfrm_policy *old_pol;
2252
2253 #ifdef CONFIG_XFRM_SUB_POLICY
2254         if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
2255                 return -EINVAL;
2256 #endif
2257
2258         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2259         old_pol = rcu_dereference_protected(sk->sk_policy[dir],
2260                                 lockdep_is_held(&net->xfrm.xfrm_policy_lock));
2261         if (pol) {
2262                 pol->curlft.add_time = ktime_get_real_seconds();
2263                 pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir, 0);
2264                 xfrm_sk_policy_link(pol, dir);
2265         }
2266         rcu_assign_pointer(sk->sk_policy[dir], pol);
2267         if (old_pol) {
2268                 if (pol)
2269                         xfrm_policy_requeue(old_pol, pol);
2270
2271                 /* Unlinking succeeds always. This is the only function
2272                  * allowed to delete or replace socket policy.
2273                  */
2274                 xfrm_sk_policy_unlink(old_pol, dir);
2275         }
2276         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2277
2278         if (old_pol) {
2279                 xfrm_policy_kill(old_pol);
2280         }
2281         return 0;
2282 }
2283
2284 static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
2285 {
2286         struct xfrm_policy *newp = xfrm_policy_alloc(xp_net(old), GFP_ATOMIC);
2287         struct net *net = xp_net(old);
2288
2289         if (newp) {
2290                 newp->selector = old->selector;
2291                 if (security_xfrm_policy_clone(old->security,
2292                                                &newp->security)) {
2293                         kfree(newp);
2294                         return NULL;  /* ENOMEM */
2295                 }
2296                 newp->lft = old->lft;
2297                 newp->curlft = old->curlft;
2298                 newp->mark = old->mark;
2299                 newp->if_id = old->if_id;
2300                 newp->action = old->action;
2301                 newp->flags = old->flags;
2302                 newp->xfrm_nr = old->xfrm_nr;
2303                 newp->index = old->index;
2304                 newp->type = old->type;
2305                 newp->family = old->family;
2306                 memcpy(newp->xfrm_vec, old->xfrm_vec,
2307                        newp->xfrm_nr*sizeof(struct xfrm_tmpl));
2308                 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2309                 xfrm_sk_policy_link(newp, dir);
2310                 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2311                 xfrm_pol_put(newp);
2312         }
2313         return newp;
2314 }
2315
2316 int __xfrm_sk_clone_policy(struct sock *sk, const struct sock *osk)
2317 {
2318         const struct xfrm_policy *p;
2319         struct xfrm_policy *np;
2320         int i, ret = 0;
2321
2322         rcu_read_lock();
2323         for (i = 0; i < 2; i++) {
2324                 p = rcu_dereference(osk->sk_policy[i]);
2325                 if (p) {
2326                         np = clone_policy(p, i);
2327                         if (unlikely(!np)) {
2328                                 ret = -ENOMEM;
2329                                 break;
2330                         }
2331                         rcu_assign_pointer(sk->sk_policy[i], np);
2332                 }
2333         }
2334         rcu_read_unlock();
2335         return ret;
2336 }
2337
2338 static int
2339 xfrm_get_saddr(struct net *net, int oif, xfrm_address_t *local,
2340                xfrm_address_t *remote, unsigned short family, u32 mark)
2341 {
2342         int err;
2343         const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2344
2345         if (unlikely(afinfo == NULL))
2346                 return -EINVAL;
2347         err = afinfo->get_saddr(net, oif, local, remote, mark);
2348         rcu_read_unlock();
2349         return err;
2350 }
2351
2352 /* Resolve list of templates for the flow, given policy. */
2353
2354 static int
2355 xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
2356                       struct xfrm_state **xfrm, unsigned short family)
2357 {
2358         struct net *net = xp_net(policy);
2359         int nx;
2360         int i, error;
2361         xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
2362         xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
2363         xfrm_address_t tmp;
2364
2365         for (nx = 0, i = 0; i < policy->xfrm_nr; i++) {
2366                 struct xfrm_state *x;
2367                 xfrm_address_t *remote = daddr;
2368                 xfrm_address_t *local  = saddr;
2369                 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
2370
2371                 if (tmpl->mode == XFRM_MODE_TUNNEL ||
2372                     tmpl->mode == XFRM_MODE_BEET) {
2373                         remote = &tmpl->id.daddr;
2374                         local = &tmpl->saddr;
2375                         if (xfrm_addr_any(local, tmpl->encap_family)) {
2376                                 error = xfrm_get_saddr(net, fl->flowi_oif,
2377                                                        &tmp, remote,
2378                                                        tmpl->encap_family, 0);
2379                                 if (error)
2380                                         goto fail;
2381                                 local = &tmp;
2382                         }
2383                 }
2384
2385                 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error,
2386                                     family, policy->if_id);
2387
2388                 if (x && x->km.state == XFRM_STATE_VALID) {
2389                         xfrm[nx++] = x;
2390                         daddr = remote;
2391                         saddr = local;
2392                         continue;
2393                 }
2394                 if (x) {
2395                         error = (x->km.state == XFRM_STATE_ERROR ?
2396                                  -EINVAL : -EAGAIN);
2397                         xfrm_state_put(x);
2398                 } else if (error == -ESRCH) {
2399                         error = -EAGAIN;
2400                 }
2401
2402                 if (!tmpl->optional)
2403                         goto fail;
2404         }
2405         return nx;
2406
2407 fail:
2408         for (nx--; nx >= 0; nx--)
2409                 xfrm_state_put(xfrm[nx]);
2410         return error;
2411 }
2412
2413 static int
2414 xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, const struct flowi *fl,
2415                   struct xfrm_state **xfrm, unsigned short family)
2416 {
2417         struct xfrm_state *tp[XFRM_MAX_DEPTH];
2418         struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
2419         int cnx = 0;
2420         int error;
2421         int ret;
2422         int i;
2423
2424         for (i = 0; i < npols; i++) {
2425                 if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
2426                         error = -ENOBUFS;
2427                         goto fail;
2428                 }
2429
2430                 ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
2431                 if (ret < 0) {
2432                         error = ret;
2433                         goto fail;
2434                 } else
2435                         cnx += ret;
2436         }
2437
2438         /* found states are sorted for outbound processing */
2439         if (npols > 1)
2440                 xfrm_state_sort(xfrm, tpp, cnx, family);
2441
2442         return cnx;
2443
2444  fail:
2445         for (cnx--; cnx >= 0; cnx--)
2446                 xfrm_state_put(tpp[cnx]);
2447         return error;
2448
2449 }
2450
2451 static int xfrm_get_tos(const struct flowi *fl, int family)
2452 {
2453         const struct xfrm_policy_afinfo *afinfo;
2454         int tos;
2455
2456         afinfo = xfrm_policy_get_afinfo(family);
2457         if (!afinfo)
2458                 return 0;
2459
2460         tos = afinfo->get_tos(fl);
2461
2462         rcu_read_unlock();
2463
2464         return tos;
2465 }
2466
2467 static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
2468 {
2469         const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2470         struct dst_ops *dst_ops;
2471         struct xfrm_dst *xdst;
2472
2473         if (!afinfo)
2474                 return ERR_PTR(-EINVAL);
2475
2476         switch (family) {
2477         case AF_INET:
2478                 dst_ops = &net->xfrm.xfrm4_dst_ops;
2479                 break;
2480 #if IS_ENABLED(CONFIG_IPV6)
2481         case AF_INET6:
2482                 dst_ops = &net->xfrm.xfrm6_dst_ops;
2483                 break;
2484 #endif
2485         default:
2486                 BUG();
2487         }
2488         xdst = dst_alloc(dst_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2489
2490         if (likely(xdst)) {
2491                 struct dst_entry *dst = &xdst->u.dst;
2492
2493                 memset(dst + 1, 0, sizeof(*xdst) - sizeof(*dst));
2494         } else
2495                 xdst = ERR_PTR(-ENOBUFS);
2496
2497         rcu_read_unlock();
2498
2499         return xdst;
2500 }
2501
2502 static inline int xfrm_init_path(struct xfrm_dst *path, struct dst_entry *dst,
2503                                  int nfheader_len)
2504 {
2505         const struct xfrm_policy_afinfo *afinfo =
2506                 xfrm_policy_get_afinfo(dst->ops->family);
2507         int err;
2508
2509         if (!afinfo)
2510                 return -EINVAL;
2511
2512         err = afinfo->init_path(path, dst, nfheader_len);
2513
2514         rcu_read_unlock();
2515
2516         return err;
2517 }
2518
2519 static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
2520                                 const struct flowi *fl)
2521 {
2522         const struct xfrm_policy_afinfo *afinfo =
2523                 xfrm_policy_get_afinfo(xdst->u.dst.ops->family);
2524         int err;
2525
2526         if (!afinfo)
2527                 return -EINVAL;
2528
2529         err = afinfo->fill_dst(xdst, dev, fl);
2530
2531         rcu_read_unlock();
2532
2533         return err;
2534 }
2535
2536
2537 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
2538  * all the metrics... Shortly, bundle a bundle.
2539  */
2540
2541 static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
2542                                             struct xfrm_state **xfrm,
2543                                             struct xfrm_dst **bundle,
2544                                             int nx,
2545                                             const struct flowi *fl,
2546                                             struct dst_entry *dst)
2547 {
2548         struct net *net = xp_net(policy);
2549         unsigned long now = jiffies;
2550         struct net_device *dev;
2551         struct xfrm_mode *inner_mode;
2552         struct xfrm_dst *xdst_prev = NULL;
2553         struct xfrm_dst *xdst0 = NULL;
2554         int i = 0;
2555         int err;
2556         int header_len = 0;
2557         int nfheader_len = 0;
2558         int trailer_len = 0;
2559         int tos;
2560         int family = policy->selector.family;
2561         xfrm_address_t saddr, daddr;
2562
2563         xfrm_flowi_addr_get(fl, &saddr, &daddr, family);
2564
2565         tos = xfrm_get_tos(fl, family);
2566
2567         dst_hold(dst);
2568
2569         for (; i < nx; i++) {
2570                 struct xfrm_dst *xdst = xfrm_alloc_dst(net, family);
2571                 struct dst_entry *dst1 = &xdst->u.dst;
2572
2573                 err = PTR_ERR(xdst);
2574                 if (IS_ERR(xdst)) {
2575                         dst_release(dst);
2576                         goto put_states;
2577                 }
2578
2579                 bundle[i] = xdst;
2580                 if (!xdst_prev)
2581                         xdst0 = xdst;
2582                 else
2583                         /* Ref count is taken during xfrm_alloc_dst()
2584                          * No need to do dst_clone() on dst1
2585                          */
2586                         xfrm_dst_set_child(xdst_prev, &xdst->u.dst);
2587
2588                 if (xfrm[i]->sel.family == AF_UNSPEC) {
2589                         inner_mode = xfrm_ip2inner_mode(xfrm[i],
2590                                                         xfrm_af2proto(family));
2591                         if (!inner_mode) {
2592                                 err = -EAFNOSUPPORT;
2593                                 dst_release(dst);
2594                                 goto put_states;
2595                         }
2596                 } else
2597                         inner_mode = xfrm[i]->inner_mode;
2598
2599                 xdst->route = dst;
2600                 dst_copy_metrics(dst1, dst);
2601
2602                 if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
2603                         __u32 mark = 0;
2604
2605                         if (xfrm[i]->props.smark.v || xfrm[i]->props.smark.m)
2606                                 mark = xfrm_smark_get(fl->flowi_mark, xfrm[i]);
2607
2608                         family = xfrm[i]->props.family;
2609                         dst = xfrm_dst_lookup(xfrm[i], tos, fl->flowi_oif,
2610                                               &saddr, &daddr, family, mark);
2611                         err = PTR_ERR(dst);
2612                         if (IS_ERR(dst))
2613                                 goto put_states;
2614                 } else
2615                         dst_hold(dst);
2616
2617                 dst1->xfrm = xfrm[i];
2618                 xdst->xfrm_genid = xfrm[i]->genid;
2619
2620                 dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
2621                 dst1->flags |= DST_HOST;
2622                 dst1->lastuse = now;
2623
2624                 dst1->input = dst_discard;
2625                 dst1->output = inner_mode->afinfo->output;
2626
2627                 xdst_prev = xdst;
2628
2629                 header_len += xfrm[i]->props.header_len;
2630                 if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
2631                         nfheader_len += xfrm[i]->props.header_len;
2632                 trailer_len += xfrm[i]->props.trailer_len;
2633         }
2634
2635         xfrm_dst_set_child(xdst_prev, dst);
2636         xdst0->path = dst;
2637
2638         err = -ENODEV;
2639         dev = dst->dev;
2640         if (!dev)
2641                 goto free_dst;
2642
2643         xfrm_init_path(xdst0, dst, nfheader_len);
2644         xfrm_init_pmtu(bundle, nx);
2645
2646         for (xdst_prev = xdst0; xdst_prev != (struct xfrm_dst *)dst;
2647              xdst_prev = (struct xfrm_dst *) xfrm_dst_child(&xdst_prev->u.dst)) {
2648                 err = xfrm_fill_dst(xdst_prev, dev, fl);
2649                 if (err)
2650                         goto free_dst;
2651
2652                 xdst_prev->u.dst.header_len = header_len;
2653                 xdst_prev->u.dst.trailer_len = trailer_len;
2654                 header_len -= xdst_prev->u.dst.xfrm->props.header_len;
2655                 trailer_len -= xdst_prev->u.dst.xfrm->props.trailer_len;
2656         }
2657
2658         return &xdst0->u.dst;
2659
2660 put_states:
2661         for (; i < nx; i++)
2662                 xfrm_state_put(xfrm[i]);
2663 free_dst:
2664         if (xdst0)
2665                 dst_release_immediate(&xdst0->u.dst);
2666
2667         return ERR_PTR(err);
2668 }
2669
2670 static int xfrm_expand_policies(const struct flowi *fl, u16 family,
2671                                 struct xfrm_policy **pols,
2672                                 int *num_pols, int *num_xfrms)
2673 {
2674         int i;
2675
2676         if (*num_pols == 0 || !pols[0]) {
2677                 *num_pols = 0;
2678                 *num_xfrms = 0;
2679                 return 0;
2680         }
2681         if (IS_ERR(pols[0]))
2682                 return PTR_ERR(pols[0]);
2683
2684         *num_xfrms = pols[0]->xfrm_nr;
2685
2686 #ifdef CONFIG_XFRM_SUB_POLICY
2687         if (pols[0] && pols[0]->action == XFRM_POLICY_ALLOW &&
2688             pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
2689                 pols[1] = xfrm_policy_lookup_bytype(xp_net(pols[0]),
2690                                                     XFRM_POLICY_TYPE_MAIN,
2691                                                     fl, family,
2692                                                     XFRM_POLICY_OUT,
2693                                                     pols[0]->if_id);
2694                 if (pols[1]) {
2695                         if (IS_ERR(pols[1])) {
2696                                 xfrm_pols_put(pols, *num_pols);
2697                                 return PTR_ERR(pols[1]);
2698                         }
2699                         (*num_pols)++;
2700                         (*num_xfrms) += pols[1]->xfrm_nr;
2701                 }
2702         }
2703 #endif
2704         for (i = 0; i < *num_pols; i++) {
2705                 if (pols[i]->action != XFRM_POLICY_ALLOW) {
2706                         *num_xfrms = -1;
2707                         break;
2708                 }
2709         }
2710
2711         return 0;
2712
2713 }
2714
2715 static struct xfrm_dst *
2716 xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
2717                                const struct flowi *fl, u16 family,
2718                                struct dst_entry *dst_orig)
2719 {
2720         struct net *net = xp_net(pols[0]);
2721         struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
2722         struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
2723         struct xfrm_dst *xdst;
2724         struct dst_entry *dst;
2725         int err;
2726
2727         /* Try to instantiate a bundle */
2728         err = xfrm_tmpl_resolve(pols, num_pols, fl, xfrm, family);
2729         if (err <= 0) {
2730                 if (err == 0)
2731                         return NULL;
2732
2733                 if (err != -EAGAIN)
2734                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
2735                 return ERR_PTR(err);
2736         }
2737
2738         dst = xfrm_bundle_create(pols[0], xfrm, bundle, err, fl, dst_orig);
2739         if (IS_ERR(dst)) {
2740                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR);
2741                 return ERR_CAST(dst);
2742         }
2743
2744         xdst = (struct xfrm_dst *)dst;
2745         xdst->num_xfrms = err;
2746         xdst->num_pols = num_pols;
2747         memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
2748         xdst->policy_genid = atomic_read(&pols[0]->genid);
2749
2750         return xdst;
2751 }
2752
2753 static void xfrm_policy_queue_process(struct timer_list *t)
2754 {
2755         struct sk_buff *skb;
2756         struct sock *sk;
2757         struct dst_entry *dst;
2758         struct xfrm_policy *pol = from_timer(pol, t, polq.hold_timer);
2759         struct net *net = xp_net(pol);
2760         struct xfrm_policy_queue *pq = &pol->polq;
2761         struct flowi fl;
2762         struct sk_buff_head list;
2763
2764         spin_lock(&pq->hold_queue.lock);
2765         skb = skb_peek(&pq->hold_queue);
2766         if (!skb) {
2767                 spin_unlock(&pq->hold_queue.lock);
2768                 goto out;
2769         }
2770         dst = skb_dst(skb);
2771         sk = skb->sk;
2772         xfrm_decode_session(skb, &fl, dst->ops->family);
2773         spin_unlock(&pq->hold_queue.lock);
2774
2775         dst_hold(xfrm_dst_path(dst));
2776         dst = xfrm_lookup(net, xfrm_dst_path(dst), &fl, sk, XFRM_LOOKUP_QUEUE);
2777         if (IS_ERR(dst))
2778                 goto purge_queue;
2779
2780         if (dst->flags & DST_XFRM_QUEUE) {
2781                 dst_release(dst);
2782
2783                 if (pq->timeout >= XFRM_QUEUE_TMO_MAX)
2784                         goto purge_queue;
2785
2786                 pq->timeout = pq->timeout << 1;
2787                 if (!mod_timer(&pq->hold_timer, jiffies + pq->timeout))
2788                         xfrm_pol_hold(pol);
2789                 goto out;
2790         }
2791
2792         dst_release(dst);
2793
2794         __skb_queue_head_init(&list);
2795
2796         spin_lock(&pq->hold_queue.lock);
2797         pq->timeout = 0;
2798         skb_queue_splice_init(&pq->hold_queue, &list);
2799         spin_unlock(&pq->hold_queue.lock);
2800
2801         while (!skb_queue_empty(&list)) {
2802                 skb = __skb_dequeue(&list);
2803
2804                 xfrm_decode_session(skb, &fl, skb_dst(skb)->ops->family);
2805                 dst_hold(xfrm_dst_path(skb_dst(skb)));
2806                 dst = xfrm_lookup(net, xfrm_dst_path(skb_dst(skb)), &fl, skb->sk, 0);
2807                 if (IS_ERR(dst)) {
2808                         kfree_skb(skb);
2809                         continue;
2810                 }
2811
2812                 nf_reset(skb);
2813                 skb_dst_drop(skb);
2814                 skb_dst_set(skb, dst);
2815
2816                 dst_output(net, skb->sk, skb);
2817         }
2818
2819 out:
2820         xfrm_pol_put(pol);
2821         return;
2822
2823 purge_queue:
2824         pq->timeout = 0;
2825         skb_queue_purge(&pq->hold_queue);
2826         xfrm_pol_put(pol);
2827 }
2828
2829 static int xdst_queue_output(struct net *net, struct sock *sk, struct sk_buff *skb)
2830 {
2831         unsigned long sched_next;
2832         struct dst_entry *dst = skb_dst(skb);
2833         struct xfrm_dst *xdst = (struct xfrm_dst *) dst;
2834         struct xfrm_policy *pol = xdst->pols[0];
2835         struct xfrm_policy_queue *pq = &pol->polq;
2836
2837         if (unlikely(skb_fclone_busy(sk, skb))) {
2838                 kfree_skb(skb);
2839                 return 0;
2840         }
2841
2842         if (pq->hold_queue.qlen > XFRM_MAX_QUEUE_LEN) {
2843                 kfree_skb(skb);
2844                 return -EAGAIN;
2845         }
2846
2847         skb_dst_force(skb);
2848
2849         spin_lock_bh(&pq->hold_queue.lock);
2850
2851         if (!pq->timeout)
2852                 pq->timeout = XFRM_QUEUE_TMO_MIN;
2853
2854         sched_next = jiffies + pq->timeout;
2855
2856         if (del_timer(&pq->hold_timer)) {
2857                 if (time_before(pq->hold_timer.expires, sched_next))
2858                         sched_next = pq->hold_timer.expires;
2859                 xfrm_pol_put(pol);
2860         }
2861
2862         __skb_queue_tail(&pq->hold_queue, skb);
2863         if (!mod_timer(&pq->hold_timer, sched_next))
2864                 xfrm_pol_hold(pol);
2865
2866         spin_unlock_bh(&pq->hold_queue.lock);
2867
2868         return 0;
2869 }
2870
2871 static struct xfrm_dst *xfrm_create_dummy_bundle(struct net *net,
2872                                                  struct xfrm_flo *xflo,
2873                                                  const struct flowi *fl,
2874                                                  int num_xfrms,
2875                                                  u16 family)
2876 {
2877         int err;
2878         struct net_device *dev;
2879         struct dst_entry *dst;
2880         struct dst_entry *dst1;
2881         struct xfrm_dst *xdst;
2882
2883         xdst = xfrm_alloc_dst(net, family);
2884         if (IS_ERR(xdst))
2885                 return xdst;
2886
2887         if (!(xflo->flags & XFRM_LOOKUP_QUEUE) ||
2888             net->xfrm.sysctl_larval_drop ||
2889             num_xfrms <= 0)
2890                 return xdst;
2891
2892         dst = xflo->dst_orig;
2893         dst1 = &xdst->u.dst;
2894         dst_hold(dst);
2895         xdst->route = dst;
2896
2897         dst_copy_metrics(dst1, dst);
2898
2899         dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
2900         dst1->flags |= DST_HOST | DST_XFRM_QUEUE;
2901         dst1->lastuse = jiffies;
2902
2903         dst1->input = dst_discard;
2904         dst1->output = xdst_queue_output;
2905
2906         dst_hold(dst);
2907         xfrm_dst_set_child(xdst, dst);
2908         xdst->path = dst;
2909
2910         xfrm_init_path((struct xfrm_dst *)dst1, dst, 0);
2911
2912         err = -ENODEV;
2913         dev = dst->dev;
2914         if (!dev)
2915                 goto free_dst;
2916
2917         err = xfrm_fill_dst(xdst, dev, fl);
2918         if (err)
2919                 goto free_dst;
2920
2921 out:
2922         return xdst;
2923
2924 free_dst:
2925         dst_release(dst1);
2926         xdst = ERR_PTR(err);
2927         goto out;
2928 }
2929
2930 static struct xfrm_dst *xfrm_bundle_lookup(struct net *net,
2931                                            const struct flowi *fl,
2932                                            u16 family, u8 dir,
2933                                            struct xfrm_flo *xflo, u32 if_id)
2934 {
2935         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2936         int num_pols = 0, num_xfrms = 0, err;
2937         struct xfrm_dst *xdst;
2938
2939         /* Resolve policies to use if we couldn't get them from
2940          * previous cache entry */
2941         num_pols = 1;
2942         pols[0] = xfrm_policy_lookup(net, fl, family, dir, if_id);
2943         err = xfrm_expand_policies(fl, family, pols,
2944                                            &num_pols, &num_xfrms);
2945         if (err < 0)
2946                 goto inc_error;
2947         if (num_pols == 0)
2948                 return NULL;
2949         if (num_xfrms <= 0)
2950                 goto make_dummy_bundle;
2951
2952         xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family,
2953                                               xflo->dst_orig);
2954         if (IS_ERR(xdst)) {
2955                 err = PTR_ERR(xdst);
2956                 if (err == -EREMOTE) {
2957                         xfrm_pols_put(pols, num_pols);
2958                         return NULL;
2959                 }
2960
2961                 if (err != -EAGAIN)
2962                         goto error;
2963                 goto make_dummy_bundle;
2964         } else if (xdst == NULL) {
2965                 num_xfrms = 0;
2966                 goto make_dummy_bundle;
2967         }
2968
2969         return xdst;
2970
2971 make_dummy_bundle:
2972         /* We found policies, but there's no bundles to instantiate:
2973          * either because the policy blocks, has no transformations or
2974          * we could not build template (no xfrm_states).*/
2975         xdst = xfrm_create_dummy_bundle(net, xflo, fl, num_xfrms, family);
2976         if (IS_ERR(xdst)) {
2977                 xfrm_pols_put(pols, num_pols);
2978                 return ERR_CAST(xdst);
2979         }
2980         xdst->num_pols = num_pols;
2981         xdst->num_xfrms = num_xfrms;
2982         memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
2983
2984         return xdst;
2985
2986 inc_error:
2987         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
2988 error:
2989         xfrm_pols_put(pols, num_pols);
2990         return ERR_PTR(err);
2991 }
2992
2993 static struct dst_entry *make_blackhole(struct net *net, u16 family,
2994                                         struct dst_entry *dst_orig)
2995 {
2996         const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2997         struct dst_entry *ret;
2998
2999         if (!afinfo) {
3000                 dst_release(dst_orig);
3001                 return ERR_PTR(-EINVAL);
3002         } else {
3003                 ret = afinfo->blackhole_route(net, dst_orig);
3004         }
3005         rcu_read_unlock();
3006
3007         return ret;
3008 }
3009
3010 /* Finds/creates a bundle for given flow and if_id
3011  *
3012  * At the moment we eat a raw IP route. Mostly to speed up lookups
3013  * on interfaces with disabled IPsec.
3014  *
3015  * xfrm_lookup uses an if_id of 0 by default, and is provided for
3016  * compatibility
3017  */
3018 struct dst_entry *xfrm_lookup_with_ifid(struct net *net,
3019                                         struct dst_entry *dst_orig,
3020                                         const struct flowi *fl,
3021                                         const struct sock *sk,
3022                                         int flags, u32 if_id)
3023 {
3024         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
3025         struct xfrm_dst *xdst;
3026         struct dst_entry *dst, *route;
3027         u16 family = dst_orig->ops->family;
3028         u8 dir = XFRM_POLICY_OUT;
3029         int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
3030
3031         dst = NULL;
3032         xdst = NULL;
3033         route = NULL;
3034
3035         sk = sk_const_to_full_sk(sk);
3036         if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
3037                 num_pols = 1;
3038                 pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, family,
3039                                                 if_id);
3040                 err = xfrm_expand_policies(fl, family, pols,
3041                                            &num_pols, &num_xfrms);
3042                 if (err < 0)
3043                         goto dropdst;
3044
3045                 if (num_pols) {
3046                         if (num_xfrms <= 0) {
3047                                 drop_pols = num_pols;
3048                                 goto no_transform;
3049                         }
3050
3051                         xdst = xfrm_resolve_and_create_bundle(
3052                                         pols, num_pols, fl,
3053                                         family, dst_orig);
3054
3055                         if (IS_ERR(xdst)) {
3056                                 xfrm_pols_put(pols, num_pols);
3057                                 err = PTR_ERR(xdst);
3058                                 if (err == -EREMOTE)
3059                                         goto nopol;
3060
3061                                 goto dropdst;
3062                         } else if (xdst == NULL) {
3063                                 num_xfrms = 0;
3064                                 drop_pols = num_pols;
3065                                 goto no_transform;
3066                         }
3067
3068                         route = xdst->route;
3069                 }
3070         }
3071
3072         if (xdst == NULL) {
3073                 struct xfrm_flo xflo;
3074
3075                 xflo.dst_orig = dst_orig;
3076                 xflo.flags = flags;
3077
3078                 /* To accelerate a bit...  */
3079                 if ((dst_orig->flags & DST_NOXFRM) ||
3080                     !net->xfrm.policy_count[XFRM_POLICY_OUT])
3081                         goto nopol;
3082
3083                 xdst = xfrm_bundle_lookup(net, fl, family, dir, &xflo, if_id);
3084                 if (xdst == NULL)
3085                         goto nopol;
3086                 if (IS_ERR(xdst)) {
3087                         err = PTR_ERR(xdst);
3088                         goto dropdst;
3089                 }
3090
3091                 num_pols = xdst->num_pols;
3092                 num_xfrms = xdst->num_xfrms;
3093                 memcpy(pols, xdst->pols, sizeof(struct xfrm_policy *) * num_pols);
3094                 route = xdst->route;
3095         }
3096
3097         dst = &xdst->u.dst;
3098         if (route == NULL && num_xfrms > 0) {
3099                 /* The only case when xfrm_bundle_lookup() returns a
3100                  * bundle with null route, is when the template could
3101                  * not be resolved. It means policies are there, but
3102                  * bundle could not be created, since we don't yet
3103                  * have the xfrm_state's. We need to wait for KM to
3104                  * negotiate new SA's or bail out with error.*/
3105                 if (net->xfrm.sysctl_larval_drop) {
3106                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
3107                         err = -EREMOTE;
3108                         goto error;
3109                 }
3110
3111                 err = -EAGAIN;
3112
3113                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
3114                 goto error;
3115         }
3116
3117 no_transform:
3118         if (num_pols == 0)
3119                 goto nopol;
3120
3121         if ((flags & XFRM_LOOKUP_ICMP) &&
3122             !(pols[0]->flags & XFRM_POLICY_ICMP)) {
3123                 err = -ENOENT;
3124                 goto error;
3125         }
3126
3127         for (i = 0; i < num_pols; i++)
3128                 pols[i]->curlft.use_time = ktime_get_real_seconds();
3129
3130         if (num_xfrms < 0) {
3131                 /* Prohibit the flow */
3132                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLBLOCK);
3133                 err = -EPERM;
3134                 goto error;
3135         } else if (num_xfrms > 0) {
3136                 /* Flow transformed */
3137                 dst_release(dst_orig);
3138         } else {
3139                 /* Flow passes untransformed */
3140                 dst_release(dst);
3141                 dst = dst_orig;
3142         }
3143 ok:
3144         xfrm_pols_put(pols, drop_pols);
3145         if (dst && dst->xfrm &&
3146             dst->xfrm->props.mode == XFRM_MODE_TUNNEL)
3147                 dst->flags |= DST_XFRM_TUNNEL;
3148         return dst;
3149
3150 nopol:
3151         if (!(flags & XFRM_LOOKUP_ICMP)) {
3152                 dst = dst_orig;
3153                 goto ok;
3154         }
3155         err = -ENOENT;
3156 error:
3157         dst_release(dst);
3158 dropdst:
3159         if (!(flags & XFRM_LOOKUP_KEEP_DST_REF))
3160                 dst_release(dst_orig);
3161         xfrm_pols_put(pols, drop_pols);
3162         return ERR_PTR(err);
3163 }
3164 EXPORT_SYMBOL(xfrm_lookup_with_ifid);
3165
3166 /* Main function: finds/creates a bundle for given flow.
3167  *
3168  * At the moment we eat a raw IP route. Mostly to speed up lookups
3169  * on interfaces with disabled IPsec.
3170  */
3171 struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
3172                               const struct flowi *fl, const struct sock *sk,
3173                               int flags)
3174 {
3175         return xfrm_lookup_with_ifid(net, dst_orig, fl, sk, flags, 0);
3176 }
3177 EXPORT_SYMBOL(xfrm_lookup);
3178
3179 /* Callers of xfrm_lookup_route() must ensure a call to dst_output().
3180  * Otherwise we may send out blackholed packets.
3181  */
3182 struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
3183                                     const struct flowi *fl,
3184                                     const struct sock *sk, int flags)
3185 {
3186         struct dst_entry *dst = xfrm_lookup(net, dst_orig, fl, sk,
3187                                             flags | XFRM_LOOKUP_QUEUE |
3188                                             XFRM_LOOKUP_KEEP_DST_REF);
3189
3190         if (IS_ERR(dst) && PTR_ERR(dst) == -EREMOTE)
3191                 return make_blackhole(net, dst_orig->ops->family, dst_orig);
3192
3193         if (IS_ERR(dst))