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TOMOYO Linux Cross Reference
Linux/net/xfrm/xfrm_policy.c

Version: ~ [ linux-5.8-rc3 ] ~ [ linux-5.7.5 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.48 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.129 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.185 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.228 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.228 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 <net/dst.h>
 30 #include <net/flow.h>
 31 #include <net/xfrm.h>
 32 #include <net/ip.h>
 33 #ifdef CONFIG_XFRM_STATISTICS
 34 #include <net/snmp.h>
 35 #endif
 36 
 37 #include "xfrm_hash.h"
 38 
 39 #define XFRM_QUEUE_TMO_MIN ((unsigned)(HZ/10))
 40 #define XFRM_QUEUE_TMO_MAX ((unsigned)(60*HZ))
 41 #define XFRM_MAX_QUEUE_LEN      100
 42 
 43 struct xfrm_flo {
 44         struct dst_entry *dst_orig;
 45         u8 flags;
 46 };
 47 
 48 static DEFINE_PER_CPU(struct xfrm_dst *, xfrm_last_dst);
 49 static struct work_struct *xfrm_pcpu_work __read_mostly;
 50 static DEFINE_SPINLOCK(xfrm_policy_afinfo_lock);
 51 static struct xfrm_policy_afinfo const __rcu *xfrm_policy_afinfo[AF_INET6 + 1]
 52                                                 __read_mostly;
 53 
 54 static struct kmem_cache *xfrm_dst_cache __ro_after_init;
 55 static __read_mostly seqcount_t xfrm_policy_hash_generation;
 56 
 57 static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr);
 58 static int stale_bundle(struct dst_entry *dst);
 59 static int xfrm_bundle_ok(struct xfrm_dst *xdst);
 60 static void xfrm_policy_queue_process(struct timer_list *t);
 61 
 62 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir);
 63 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
 64                                                 int dir);
 65 
 66 static inline bool xfrm_pol_hold_rcu(struct xfrm_policy *policy)
 67 {
 68         return refcount_inc_not_zero(&policy->refcnt);
 69 }
 70 
 71 static inline bool
 72 __xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
 73 {
 74         const struct flowi4 *fl4 = &fl->u.ip4;
 75 
 76         return  addr4_match(fl4->daddr, sel->daddr.a4, sel->prefixlen_d) &&
 77                 addr4_match(fl4->saddr, sel->saddr.a4, sel->prefixlen_s) &&
 78                 !((xfrm_flowi_dport(fl, &fl4->uli) ^ sel->dport) & sel->dport_mask) &&
 79                 !((xfrm_flowi_sport(fl, &fl4->uli) ^ sel->sport) & sel->sport_mask) &&
 80                 (fl4->flowi4_proto == sel->proto || !sel->proto) &&
 81                 (fl4->flowi4_oif == sel->ifindex || !sel->ifindex);
 82 }
 83 
 84 static inline bool
 85 __xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
 86 {
 87         const struct flowi6 *fl6 = &fl->u.ip6;
 88 
 89         return  addr_match(&fl6->daddr, &sel->daddr, sel->prefixlen_d) &&
 90                 addr_match(&fl6->saddr, &sel->saddr, sel->prefixlen_s) &&
 91                 !((xfrm_flowi_dport(fl, &fl6->uli) ^ sel->dport) & sel->dport_mask) &&
 92                 !((xfrm_flowi_sport(fl, &fl6->uli) ^ sel->sport) & sel->sport_mask) &&
 93                 (fl6->flowi6_proto == sel->proto || !sel->proto) &&
 94                 (fl6->flowi6_oif == sel->ifindex || !sel->ifindex);
 95 }
 96 
 97 bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl,
 98                          unsigned short family)
 99 {
100         switch (family) {
101         case AF_INET:
102                 return __xfrm4_selector_match(sel, fl);
103         case AF_INET6:
104                 return __xfrm6_selector_match(sel, fl);
105         }
106         return false;
107 }
108 
109 static const struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
110 {
111         const struct xfrm_policy_afinfo *afinfo;
112 
113         if (unlikely(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
114                 return NULL;
115         rcu_read_lock();
116         afinfo = rcu_dereference(xfrm_policy_afinfo[family]);
117         if (unlikely(!afinfo))
118                 rcu_read_unlock();
119         return afinfo;
120 }
121 
122 struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos, int oif,
123                                     const xfrm_address_t *saddr,
124                                     const xfrm_address_t *daddr,
125                                     int family, u32 mark)
126 {
127         const struct xfrm_policy_afinfo *afinfo;
128         struct dst_entry *dst;
129 
130         afinfo = xfrm_policy_get_afinfo(family);
131         if (unlikely(afinfo == NULL))
132                 return ERR_PTR(-EAFNOSUPPORT);
133 
134         dst = afinfo->dst_lookup(net, tos, oif, saddr, daddr, mark);
135 
136         rcu_read_unlock();
137 
138         return dst;
139 }
140 EXPORT_SYMBOL(__xfrm_dst_lookup);
141 
142 static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x,
143                                                 int tos, int oif,
144                                                 xfrm_address_t *prev_saddr,
145                                                 xfrm_address_t *prev_daddr,
146                                                 int family, u32 mark)
147 {
148         struct net *net = xs_net(x);
149         xfrm_address_t *saddr = &x->props.saddr;
150         xfrm_address_t *daddr = &x->id.daddr;
151         struct dst_entry *dst;
152 
153         if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) {
154                 saddr = x->coaddr;
155                 daddr = prev_daddr;
156         }
157         if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) {
158                 saddr = prev_saddr;
159                 daddr = x->coaddr;
160         }
161 
162         dst = __xfrm_dst_lookup(net, tos, oif, saddr, daddr, family, mark);
163 
164         if (!IS_ERR(dst)) {
165                 if (prev_saddr != saddr)
166                         memcpy(prev_saddr, saddr,  sizeof(*prev_saddr));
167                 if (prev_daddr != daddr)
168                         memcpy(prev_daddr, daddr,  sizeof(*prev_daddr));
169         }
170 
171         return dst;
172 }
173 
174 static inline unsigned long make_jiffies(long secs)
175 {
176         if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
177                 return MAX_SCHEDULE_TIMEOUT-1;
178         else
179                 return secs*HZ;
180 }
181 
182 static void xfrm_policy_timer(struct timer_list *t)
183 {
184         struct xfrm_policy *xp = from_timer(xp, t, timer);
185         unsigned long now = get_seconds();
186         long next = LONG_MAX;
187         int warn = 0;
188         int dir;
189 
190         read_lock(&xp->lock);
191 
192         if (unlikely(xp->walk.dead))
193                 goto out;
194 
195         dir = xfrm_policy_id2dir(xp->index);
196 
197         if (xp->lft.hard_add_expires_seconds) {
198                 long tmo = xp->lft.hard_add_expires_seconds +
199                         xp->curlft.add_time - now;
200                 if (tmo <= 0)
201                         goto expired;
202                 if (tmo < next)
203                         next = tmo;
204         }
205         if (xp->lft.hard_use_expires_seconds) {
206                 long tmo = xp->lft.hard_use_expires_seconds +
207                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
208                 if (tmo <= 0)
209                         goto expired;
210                 if (tmo < next)
211                         next = tmo;
212         }
213         if (xp->lft.soft_add_expires_seconds) {
214                 long tmo = xp->lft.soft_add_expires_seconds +
215                         xp->curlft.add_time - now;
216                 if (tmo <= 0) {
217                         warn = 1;
218                         tmo = XFRM_KM_TIMEOUT;
219                 }
220                 if (tmo < next)
221                         next = tmo;
222         }
223         if (xp->lft.soft_use_expires_seconds) {
224                 long tmo = xp->lft.soft_use_expires_seconds +
225                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
226                 if (tmo <= 0) {
227                         warn = 1;
228                         tmo = XFRM_KM_TIMEOUT;
229                 }
230                 if (tmo < next)
231                         next = tmo;
232         }
233 
234         if (warn)
235                 km_policy_expired(xp, dir, 0, 0);
236         if (next != LONG_MAX &&
237             !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
238                 xfrm_pol_hold(xp);
239 
240 out:
241         read_unlock(&xp->lock);
242         xfrm_pol_put(xp);
243         return;
244 
245 expired:
246         read_unlock(&xp->lock);
247         if (!xfrm_policy_delete(xp, dir))
248                 km_policy_expired(xp, dir, 1, 0);
249         xfrm_pol_put(xp);
250 }
251 
252 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
253  * SPD calls.
254  */
255 
256 struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
257 {
258         struct xfrm_policy *policy;
259 
260         policy = kzalloc(sizeof(struct xfrm_policy), gfp);
261 
262         if (policy) {
263                 write_pnet(&policy->xp_net, net);
264                 INIT_LIST_HEAD(&policy->walk.all);
265                 INIT_HLIST_NODE(&policy->bydst);
266                 INIT_HLIST_NODE(&policy->byidx);
267                 rwlock_init(&policy->lock);
268                 refcount_set(&policy->refcnt, 1);
269                 skb_queue_head_init(&policy->polq.hold_queue);
270                 timer_setup(&policy->timer, xfrm_policy_timer, 0);
271                 timer_setup(&policy->polq.hold_timer,
272                             xfrm_policy_queue_process, 0);
273         }
274         return policy;
275 }
276 EXPORT_SYMBOL(xfrm_policy_alloc);
277 
278 static void xfrm_policy_destroy_rcu(struct rcu_head *head)
279 {
280         struct xfrm_policy *policy = container_of(head, struct xfrm_policy, rcu);
281 
282         security_xfrm_policy_free(policy->security);
283         kfree(policy);
284 }
285 
286 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
287 
288 void xfrm_policy_destroy(struct xfrm_policy *policy)
289 {
290         BUG_ON(!policy->walk.dead);
291 
292         if (del_timer(&policy->timer) || del_timer(&policy->polq.hold_timer))
293                 BUG();
294 
295         call_rcu(&policy->rcu, xfrm_policy_destroy_rcu);
296 }
297 EXPORT_SYMBOL(xfrm_policy_destroy);
298 
299 /* Rule must be locked. Release descendant resources, announce
300  * entry dead. The rule must be unlinked from lists to the moment.
301  */
302 
303 static void xfrm_policy_kill(struct xfrm_policy *policy)
304 {
305         policy->walk.dead = 1;
306 
307         atomic_inc(&policy->genid);
308 
309         if (del_timer(&policy->polq.hold_timer))
310                 xfrm_pol_put(policy);
311         skb_queue_purge(&policy->polq.hold_queue);
312 
313         if (del_timer(&policy->timer))
314                 xfrm_pol_put(policy);
315 
316         xfrm_pol_put(policy);
317 }
318 
319 static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
320 
321 static inline unsigned int idx_hash(struct net *net, u32 index)
322 {
323         return __idx_hash(index, net->xfrm.policy_idx_hmask);
324 }
325 
326 /* calculate policy hash thresholds */
327 static void __get_hash_thresh(struct net *net,
328                               unsigned short family, int dir,
329                               u8 *dbits, u8 *sbits)
330 {
331         switch (family) {
332         case AF_INET:
333                 *dbits = net->xfrm.policy_bydst[dir].dbits4;
334                 *sbits = net->xfrm.policy_bydst[dir].sbits4;
335                 break;
336 
337         case AF_INET6:
338                 *dbits = net->xfrm.policy_bydst[dir].dbits6;
339                 *sbits = net->xfrm.policy_bydst[dir].sbits6;
340                 break;
341 
342         default:
343                 *dbits = 0;
344                 *sbits = 0;
345         }
346 }
347 
348 static struct hlist_head *policy_hash_bysel(struct net *net,
349                                             const struct xfrm_selector *sel,
350                                             unsigned short family, int dir)
351 {
352         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
353         unsigned int hash;
354         u8 dbits;
355         u8 sbits;
356 
357         __get_hash_thresh(net, family, dir, &dbits, &sbits);
358         hash = __sel_hash(sel, family, hmask, dbits, sbits);
359 
360         if (hash == hmask + 1)
361                 return &net->xfrm.policy_inexact[dir];
362 
363         return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
364                      lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
365 }
366 
367 static struct hlist_head *policy_hash_direct(struct net *net,
368                                              const xfrm_address_t *daddr,
369                                              const xfrm_address_t *saddr,
370                                              unsigned short family, int dir)
371 {
372         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
373         unsigned int hash;
374         u8 dbits;
375         u8 sbits;
376 
377         __get_hash_thresh(net, family, dir, &dbits, &sbits);
378         hash = __addr_hash(daddr, saddr, family, hmask, dbits, sbits);
379 
380         return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
381                      lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
382 }
383 
384 static void xfrm_dst_hash_transfer(struct net *net,
385                                    struct hlist_head *list,
386                                    struct hlist_head *ndsttable,
387                                    unsigned int nhashmask,
388                                    int dir)
389 {
390         struct hlist_node *tmp, *entry0 = NULL;
391         struct xfrm_policy *pol;
392         unsigned int h0 = 0;
393         u8 dbits;
394         u8 sbits;
395 
396 redo:
397         hlist_for_each_entry_safe(pol, tmp, list, bydst) {
398                 unsigned int h;
399 
400                 __get_hash_thresh(net, pol->family, dir, &dbits, &sbits);
401                 h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
402                                 pol->family, nhashmask, dbits, sbits);
403                 if (!entry0) {
404                         hlist_del_rcu(&pol->bydst);
405                         hlist_add_head_rcu(&pol->bydst, ndsttable + h);
406                         h0 = h;
407                 } else {
408                         if (h != h0)
409                                 continue;
410                         hlist_del_rcu(&pol->bydst);
411                         hlist_add_behind_rcu(&pol->bydst, entry0);
412                 }
413                 entry0 = &pol->bydst;
414         }
415         if (!hlist_empty(list)) {
416                 entry0 = NULL;
417                 goto redo;
418         }
419 }
420 
421 static void xfrm_idx_hash_transfer(struct hlist_head *list,
422                                    struct hlist_head *nidxtable,
423                                    unsigned int nhashmask)
424 {
425         struct hlist_node *tmp;
426         struct xfrm_policy *pol;
427 
428         hlist_for_each_entry_safe(pol, tmp, list, byidx) {
429                 unsigned int h;
430 
431                 h = __idx_hash(pol->index, nhashmask);
432                 hlist_add_head(&pol->byidx, nidxtable+h);
433         }
434 }
435 
436 static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
437 {
438         return ((old_hmask + 1) << 1) - 1;
439 }
440 
441 static void xfrm_bydst_resize(struct net *net, int dir)
442 {
443         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
444         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
445         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
446         struct hlist_head *ndst = xfrm_hash_alloc(nsize);
447         struct hlist_head *odst;
448         int i;
449 
450         if (!ndst)
451                 return;
452 
453         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
454         write_seqcount_begin(&xfrm_policy_hash_generation);
455 
456         odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
457                                 lockdep_is_held(&net->xfrm.xfrm_policy_lock));
458 
459         odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
460                                 lockdep_is_held(&net->xfrm.xfrm_policy_lock));
461 
462         for (i = hmask; i >= 0; i--)
463                 xfrm_dst_hash_transfer(net, odst + i, ndst, nhashmask, dir);
464 
465         rcu_assign_pointer(net->xfrm.policy_bydst[dir].table, ndst);
466         net->xfrm.policy_bydst[dir].hmask = nhashmask;
467 
468         write_seqcount_end(&xfrm_policy_hash_generation);
469         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
470 
471         synchronize_rcu();
472 
473         xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
474 }
475 
476 static void xfrm_byidx_resize(struct net *net, int total)
477 {
478         unsigned int hmask = net->xfrm.policy_idx_hmask;
479         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
480         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
481         struct hlist_head *oidx = net->xfrm.policy_byidx;
482         struct hlist_head *nidx = xfrm_hash_alloc(nsize);
483         int i;
484 
485         if (!nidx)
486                 return;
487 
488         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
489 
490         for (i = hmask; i >= 0; i--)
491                 xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
492 
493         net->xfrm.policy_byidx = nidx;
494         net->xfrm.policy_idx_hmask = nhashmask;
495 
496         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
497 
498         xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
499 }
500 
501 static inline int xfrm_bydst_should_resize(struct net *net, int dir, int *total)
502 {
503         unsigned int cnt = net->xfrm.policy_count[dir];
504         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
505 
506         if (total)
507                 *total += cnt;
508 
509         if ((hmask + 1) < xfrm_policy_hashmax &&
510             cnt > hmask)
511                 return 1;
512 
513         return 0;
514 }
515 
516 static inline int xfrm_byidx_should_resize(struct net *net, int total)
517 {
518         unsigned int hmask = net->xfrm.policy_idx_hmask;
519 
520         if ((hmask + 1) < xfrm_policy_hashmax &&
521             total > hmask)
522                 return 1;
523 
524         return 0;
525 }
526 
527 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
528 {
529         si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
530         si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
531         si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
532         si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
533         si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
534         si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
535         si->spdhcnt = net->xfrm.policy_idx_hmask;
536         si->spdhmcnt = xfrm_policy_hashmax;
537 }
538 EXPORT_SYMBOL(xfrm_spd_getinfo);
539 
540 static DEFINE_MUTEX(hash_resize_mutex);
541 static void xfrm_hash_resize(struct work_struct *work)
542 {
543         struct net *net = container_of(work, struct net, xfrm.policy_hash_work);
544         int dir, total;
545 
546         mutex_lock(&hash_resize_mutex);
547 
548         total = 0;
549         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
550                 if (xfrm_bydst_should_resize(net, dir, &total))
551                         xfrm_bydst_resize(net, dir);
552         }
553         if (xfrm_byidx_should_resize(net, total))
554                 xfrm_byidx_resize(net, total);
555 
556         mutex_unlock(&hash_resize_mutex);
557 }
558 
559 static void xfrm_hash_rebuild(struct work_struct *work)
560 {
561         struct net *net = container_of(work, struct net,
562                                        xfrm.policy_hthresh.work);
563         unsigned int hmask;
564         struct xfrm_policy *pol;
565         struct xfrm_policy *policy;
566         struct hlist_head *chain;
567         struct hlist_head *odst;
568         struct hlist_node *newpos;
569         int i;
570         int dir;
571         unsigned seq;
572         u8 lbits4, rbits4, lbits6, rbits6;
573 
574         mutex_lock(&hash_resize_mutex);
575 
576         /* read selector prefixlen thresholds */
577         do {
578                 seq = read_seqbegin(&net->xfrm.policy_hthresh.lock);
579 
580                 lbits4 = net->xfrm.policy_hthresh.lbits4;
581                 rbits4 = net->xfrm.policy_hthresh.rbits4;
582                 lbits6 = net->xfrm.policy_hthresh.lbits6;
583                 rbits6 = net->xfrm.policy_hthresh.rbits6;
584         } while (read_seqretry(&net->xfrm.policy_hthresh.lock, seq));
585 
586         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
587 
588         /* reset the bydst and inexact table in all directions */
589         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
590                 INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
591                 hmask = net->xfrm.policy_bydst[dir].hmask;
592                 odst = net->xfrm.policy_bydst[dir].table;
593                 for (i = hmask; i >= 0; i--)
594                         INIT_HLIST_HEAD(odst + i);
595                 if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
596                         /* dir out => dst = remote, src = local */
597                         net->xfrm.policy_bydst[dir].dbits4 = rbits4;
598                         net->xfrm.policy_bydst[dir].sbits4 = lbits4;
599                         net->xfrm.policy_bydst[dir].dbits6 = rbits6;
600                         net->xfrm.policy_bydst[dir].sbits6 = lbits6;
601                 } else {
602                         /* dir in/fwd => dst = local, src = remote */
603                         net->xfrm.policy_bydst[dir].dbits4 = lbits4;
604                         net->xfrm.policy_bydst[dir].sbits4 = rbits4;
605                         net->xfrm.policy_bydst[dir].dbits6 = lbits6;
606                         net->xfrm.policy_bydst[dir].sbits6 = rbits6;
607                 }
608         }
609 
610         /* re-insert all policies by order of creation */
611         list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
612                 if (policy->walk.dead ||
613                     xfrm_policy_id2dir(policy->index) >= XFRM_POLICY_MAX) {
614                         /* skip socket policies */
615                         continue;
616                 }
617                 newpos = NULL;
618                 chain = policy_hash_bysel(net, &policy->selector,
619                                           policy->family,
620                                           xfrm_policy_id2dir(policy->index));
621                 hlist_for_each_entry(pol, chain, bydst) {
622                         if (policy->priority >= pol->priority)
623                                 newpos = &pol->bydst;
624                         else
625                                 break;
626                 }
627                 if (newpos)
628                         hlist_add_behind_rcu(&policy->bydst, newpos);
629                 else
630                         hlist_add_head_rcu(&policy->bydst, chain);
631         }
632 
633         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
634 
635         mutex_unlock(&hash_resize_mutex);
636 }
637 
638 void xfrm_policy_hash_rebuild(struct net *net)
639 {
640         schedule_work(&net->xfrm.policy_hthresh.work);
641 }
642 EXPORT_SYMBOL(xfrm_policy_hash_rebuild);
643 
644 /* Generate new index... KAME seems to generate them ordered by cost
645  * of an absolute inpredictability of ordering of rules. This will not pass. */
646 static u32 xfrm_gen_index(struct net *net, int dir, u32 index)
647 {
648         static u32 idx_generator;
649 
650         for (;;) {
651                 struct hlist_head *list;
652                 struct xfrm_policy *p;
653                 u32 idx;
654                 int found;
655 
656                 if (!index) {
657                         idx = (idx_generator | dir);
658                         idx_generator += 8;
659                 } else {
660                         idx = index;
661                         index = 0;
662                 }
663 
664                 if (idx == 0)
665                         idx = 8;
666                 list = net->xfrm.policy_byidx + idx_hash(net, idx);
667                 found = 0;
668                 hlist_for_each_entry(p, list, byidx) {
669                         if (p->index == idx) {
670                                 found = 1;
671                                 break;
672                         }
673                 }
674                 if (!found)
675                         return idx;
676         }
677 }
678 
679 static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
680 {
681         u32 *p1 = (u32 *) s1;
682         u32 *p2 = (u32 *) s2;
683         int len = sizeof(struct xfrm_selector) / sizeof(u32);
684         int i;
685 
686         for (i = 0; i < len; i++) {
687                 if (p1[i] != p2[i])
688                         return 1;
689         }
690 
691         return 0;
692 }
693 
694 static void xfrm_policy_requeue(struct xfrm_policy *old,
695                                 struct xfrm_policy *new)
696 {
697         struct xfrm_policy_queue *pq = &old->polq;
698         struct sk_buff_head list;
699 
700         if (skb_queue_empty(&pq->hold_queue))
701                 return;
702 
703         __skb_queue_head_init(&list);
704 
705         spin_lock_bh(&pq->hold_queue.lock);
706         skb_queue_splice_init(&pq->hold_queue, &list);
707         if (del_timer(&pq->hold_timer))
708                 xfrm_pol_put(old);
709         spin_unlock_bh(&pq->hold_queue.lock);
710 
711         pq = &new->polq;
712 
713         spin_lock_bh(&pq->hold_queue.lock);
714         skb_queue_splice(&list, &pq->hold_queue);
715         pq->timeout = XFRM_QUEUE_TMO_MIN;
716         if (!mod_timer(&pq->hold_timer, jiffies))
717                 xfrm_pol_hold(new);
718         spin_unlock_bh(&pq->hold_queue.lock);
719 }
720 
721 static bool xfrm_policy_mark_match(struct xfrm_policy *policy,
722                                    struct xfrm_policy *pol)
723 {
724         u32 mark = policy->mark.v & policy->mark.m;
725 
726         if (policy->mark.v == pol->mark.v && policy->mark.m == pol->mark.m)
727                 return true;
728 
729         if ((mark & pol->mark.m) == pol->mark.v &&
730             policy->priority == pol->priority)
731                 return true;
732 
733         return false;
734 }
735 
736 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
737 {
738         struct net *net = xp_net(policy);
739         struct xfrm_policy *pol;
740         struct xfrm_policy *delpol;
741         struct hlist_head *chain;
742         struct hlist_node *newpos;
743 
744         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
745         chain = policy_hash_bysel(net, &policy->selector, policy->family, dir);
746         delpol = NULL;
747         newpos = NULL;
748         hlist_for_each_entry(pol, chain, bydst) {
749                 if (pol->type == policy->type &&
750                     !selector_cmp(&pol->selector, &policy->selector) &&
751                     xfrm_policy_mark_match(policy, pol) &&
752                     xfrm_sec_ctx_match(pol->security, policy->security) &&
753                     !WARN_ON(delpol)) {
754                         if (excl) {
755                                 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
756                                 return -EEXIST;
757                         }
758                         delpol = pol;
759                         if (policy->priority > pol->priority)
760                                 continue;
761                 } else if (policy->priority >= pol->priority) {
762                         newpos = &pol->bydst;
763                         continue;
764                 }
765                 if (delpol)
766                         break;
767         }
768         if (newpos)
769                 hlist_add_behind_rcu(&policy->bydst, newpos);
770         else
771                 hlist_add_head_rcu(&policy->bydst, chain);
772         __xfrm_policy_link(policy, dir);
773 
774         /* After previous checking, family can either be AF_INET or AF_INET6 */
775         if (policy->family == AF_INET)
776                 rt_genid_bump_ipv4(net);
777         else
778                 rt_genid_bump_ipv6(net);
779 
780         if (delpol) {
781                 xfrm_policy_requeue(delpol, policy);
782                 __xfrm_policy_unlink(delpol, dir);
783         }
784         policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir, policy->index);
785         hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
786         policy->curlft.add_time = get_seconds();
787         policy->curlft.use_time = 0;
788         if (!mod_timer(&policy->timer, jiffies + HZ))
789                 xfrm_pol_hold(policy);
790         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
791 
792         if (delpol)
793                 xfrm_policy_kill(delpol);
794         else if (xfrm_bydst_should_resize(net, dir, NULL))
795                 schedule_work(&net->xfrm.policy_hash_work);
796 
797         return 0;
798 }
799 EXPORT_SYMBOL(xfrm_policy_insert);
800 
801 struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u8 type,
802                                           int dir, struct xfrm_selector *sel,
803                                           struct xfrm_sec_ctx *ctx, int delete,
804                                           int *err)
805 {
806         struct xfrm_policy *pol, *ret;
807         struct hlist_head *chain;
808 
809         *err = 0;
810         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
811         chain = policy_hash_bysel(net, sel, sel->family, dir);
812         ret = NULL;
813         hlist_for_each_entry(pol, chain, bydst) {
814                 if (pol->type == type &&
815                     (mark & pol->mark.m) == pol->mark.v &&
816                     !selector_cmp(sel, &pol->selector) &&
817                     xfrm_sec_ctx_match(ctx, pol->security)) {
818                         xfrm_pol_hold(pol);
819                         if (delete) {
820                                 *err = security_xfrm_policy_delete(
821                                                                 pol->security);
822                                 if (*err) {
823                                         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
824                                         return pol;
825                                 }
826                                 __xfrm_policy_unlink(pol, dir);
827                         }
828                         ret = pol;
829                         break;
830                 }
831         }
832         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
833 
834         if (ret && delete)
835                 xfrm_policy_kill(ret);
836         return ret;
837 }
838 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
839 
840 struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8 type,
841                                      int dir, u32 id, int delete, int *err)
842 {
843         struct xfrm_policy *pol, *ret;
844         struct hlist_head *chain;
845 
846         *err = -ENOENT;
847         if (xfrm_policy_id2dir(id) != dir)
848                 return NULL;
849 
850         *err = 0;
851         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
852         chain = net->xfrm.policy_byidx + idx_hash(net, id);
853         ret = NULL;
854         hlist_for_each_entry(pol, chain, byidx) {
855                 if (pol->type == type && pol->index == id &&
856                     (mark & pol->mark.m) == pol->mark.v) {
857                         xfrm_pol_hold(pol);
858                         if (delete) {
859                                 *err = security_xfrm_policy_delete(
860                                                                 pol->security);
861                                 if (*err) {
862                                         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
863                                         return pol;
864                                 }
865                                 __xfrm_policy_unlink(pol, dir);
866                         }
867                         ret = pol;
868                         break;
869                 }
870         }
871         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
872 
873         if (ret && delete)
874                 xfrm_policy_kill(ret);
875         return ret;
876 }
877 EXPORT_SYMBOL(xfrm_policy_byid);
878 
879 #ifdef CONFIG_SECURITY_NETWORK_XFRM
880 static inline int
881 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
882 {
883         int dir, err = 0;
884 
885         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
886                 struct xfrm_policy *pol;
887                 int i;
888 
889                 hlist_for_each_entry(pol,
890                                      &net->xfrm.policy_inexact[dir], bydst) {
891                         if (pol->type != type)
892                                 continue;
893                         err = security_xfrm_policy_delete(pol->security);
894                         if (err) {
895                                 xfrm_audit_policy_delete(pol, 0, task_valid);
896                                 return err;
897                         }
898                 }
899                 for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
900                         hlist_for_each_entry(pol,
901                                              net->xfrm.policy_bydst[dir].table + i,
902                                              bydst) {
903                                 if (pol->type != type)
904                                         continue;
905                                 err = security_xfrm_policy_delete(
906                                                                 pol->security);
907                                 if (err) {
908                                         xfrm_audit_policy_delete(pol, 0,
909                                                                  task_valid);
910                                         return err;
911                                 }
912                         }
913                 }
914         }
915         return err;
916 }
917 #else
918 static inline int
919 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
920 {
921         return 0;
922 }
923 #endif
924 
925 int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
926 {
927         int dir, err = 0, cnt = 0;
928 
929         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
930 
931         err = xfrm_policy_flush_secctx_check(net, type, task_valid);
932         if (err)
933                 goto out;
934 
935         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
936                 struct xfrm_policy *pol;
937                 int i;
938 
939         again1:
940                 hlist_for_each_entry(pol,
941                                      &net->xfrm.policy_inexact[dir], bydst) {
942                         if (pol->type != type)
943                                 continue;
944                         __xfrm_policy_unlink(pol, dir);
945                         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
946                         cnt++;
947 
948                         xfrm_audit_policy_delete(pol, 1, task_valid);
949 
950                         xfrm_policy_kill(pol);
951 
952                         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
953                         goto again1;
954                 }
955 
956                 for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
957         again2:
958                         hlist_for_each_entry(pol,
959                                              net->xfrm.policy_bydst[dir].table + i,
960                                              bydst) {
961                                 if (pol->type != type)
962                                         continue;
963                                 __xfrm_policy_unlink(pol, dir);
964                                 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
965                                 cnt++;
966 
967                                 xfrm_audit_policy_delete(pol, 1, task_valid);
968                                 xfrm_policy_kill(pol);
969 
970                                 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
971                                 goto again2;
972                         }
973                 }
974 
975         }
976         if (!cnt)
977                 err = -ESRCH;
978 out:
979         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
980         return err;
981 }
982 EXPORT_SYMBOL(xfrm_policy_flush);
983 
984 int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
985                      int (*func)(struct xfrm_policy *, int, int, void*),
986                      void *data)
987 {
988         struct xfrm_policy *pol;
989         struct xfrm_policy_walk_entry *x;
990         int error = 0;
991 
992         if (walk->type >= XFRM_POLICY_TYPE_MAX &&
993             walk->type != XFRM_POLICY_TYPE_ANY)
994                 return -EINVAL;
995 
996         if (list_empty(&walk->walk.all) && walk->seq != 0)
997                 return 0;
998 
999         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1000         if (list_empty(&walk->walk.all))
1001                 x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
1002         else
1003                 x = list_first_entry(&walk->walk.all,
1004                                      struct xfrm_policy_walk_entry, all);
1005 
1006         list_for_each_entry_from(x, &net->xfrm.policy_all, all) {
1007                 if (x->dead)
1008                         continue;
1009                 pol = container_of(x, struct xfrm_policy, walk);
1010                 if (walk->type != XFRM_POLICY_TYPE_ANY &&
1011                     walk->type != pol->type)
1012                         continue;
1013                 error = func(pol, xfrm_policy_id2dir(pol->index),
1014                              walk->seq, data);
1015                 if (error) {
1016                         list_move_tail(&walk->walk.all, &x->all);
1017                         goto out;
1018                 }
1019                 walk->seq++;
1020         }
1021         if (walk->seq == 0) {
1022                 error = -ENOENT;
1023                 goto out;
1024         }
1025         list_del_init(&walk->walk.all);
1026 out:
1027         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1028         return error;
1029 }
1030 EXPORT_SYMBOL(xfrm_policy_walk);
1031 
1032 void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type)
1033 {
1034         INIT_LIST_HEAD(&walk->walk.all);
1035         walk->walk.dead = 1;
1036         walk->type = type;
1037         walk->seq = 0;
1038 }
1039 EXPORT_SYMBOL(xfrm_policy_walk_init);
1040 
1041 void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net)
1042 {
1043         if (list_empty(&walk->walk.all))
1044                 return;
1045 
1046         spin_lock_bh(&net->xfrm.xfrm_policy_lock); /*FIXME where is net? */
1047         list_del(&walk->walk.all);
1048         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1049 }
1050 EXPORT_SYMBOL(xfrm_policy_walk_done);
1051 
1052 /*
1053  * Find policy to apply to this flow.
1054  *
1055  * Returns 0 if policy found, else an -errno.
1056  */
1057 static int xfrm_policy_match(const struct xfrm_policy *pol,
1058                              const struct flowi *fl,
1059                              u8 type, u16 family, int dir)
1060 {
1061         const struct xfrm_selector *sel = &pol->selector;
1062         int ret = -ESRCH;
1063         bool match;
1064 
1065         if (pol->family != family ||
1066             (fl->flowi_mark & pol->mark.m) != pol->mark.v ||
1067             pol->type != type)
1068                 return ret;
1069 
1070         match = xfrm_selector_match(sel, fl, family);
1071         if (match)
1072                 ret = security_xfrm_policy_lookup(pol->security, fl->flowi_secid,
1073                                                   dir);
1074 
1075         return ret;
1076 }
1077 
1078 static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
1079                                                      const struct flowi *fl,
1080                                                      u16 family, u8 dir)
1081 {
1082         int err;
1083         struct xfrm_policy *pol, *ret;
1084         const xfrm_address_t *daddr, *saddr;
1085         struct hlist_head *chain;
1086         unsigned int sequence;
1087         u32 priority;
1088 
1089         daddr = xfrm_flowi_daddr(fl, family);
1090         saddr = xfrm_flowi_saddr(fl, family);
1091         if (unlikely(!daddr || !saddr))
1092                 return NULL;
1093 
1094         rcu_read_lock();
1095  retry:
1096         do {
1097                 sequence = read_seqcount_begin(&xfrm_policy_hash_generation);
1098                 chain = policy_hash_direct(net, daddr, saddr, family, dir);
1099         } while (read_seqcount_retry(&xfrm_policy_hash_generation, sequence));
1100 
1101         priority = ~0U;
1102         ret = NULL;
1103         hlist_for_each_entry_rcu(pol, chain, bydst) {
1104                 err = xfrm_policy_match(pol, fl, type, family, dir);
1105                 if (err) {
1106                         if (err == -ESRCH)
1107                                 continue;
1108                         else {
1109                                 ret = ERR_PTR(err);
1110                                 goto fail;
1111                         }
1112                 } else {
1113                         ret = pol;
1114                         priority = ret->priority;
1115                         break;
1116                 }
1117         }
1118         chain = &net->xfrm.policy_inexact[dir];
1119         hlist_for_each_entry_rcu(pol, chain, bydst) {
1120                 if ((pol->priority >= priority) && ret)
1121                         break;
1122 
1123                 err = xfrm_policy_match(pol, fl, type, family, dir);
1124                 if (err) {
1125                         if (err == -ESRCH)
1126                                 continue;
1127                         else {
1128                                 ret = ERR_PTR(err);
1129                                 goto fail;
1130                         }
1131                 } else {
1132                         ret = pol;
1133                         break;
1134                 }
1135         }
1136 
1137         if (read_seqcount_retry(&xfrm_policy_hash_generation, sequence))
1138                 goto retry;
1139 
1140         if (ret && !xfrm_pol_hold_rcu(ret))
1141                 goto retry;
1142 fail:
1143         rcu_read_unlock();
1144 
1145         return ret;
1146 }
1147 
1148 static struct xfrm_policy *
1149 xfrm_policy_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir)
1150 {
1151 #ifdef CONFIG_XFRM_SUB_POLICY
1152         struct xfrm_policy *pol;
1153 
1154         pol = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_SUB, fl, family, dir);
1155         if (pol != NULL)
1156                 return pol;
1157 #endif
1158         return xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, fl, family, dir);
1159 }
1160 
1161 static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir,
1162                                                  const struct flowi *fl, u16 family)
1163 {
1164         struct xfrm_policy *pol;
1165 
1166         rcu_read_lock();
1167  again:
1168         pol = rcu_dereference(sk->sk_policy[dir]);
1169         if (pol != NULL) {
1170                 bool match;
1171                 int err = 0;
1172 
1173                 if (pol->family != family) {
1174                         pol = NULL;
1175                         goto out;
1176                 }
1177 
1178                 match = xfrm_selector_match(&pol->selector, fl, family);
1179                 if (match) {
1180                         if ((sk->sk_mark & pol->mark.m) != pol->mark.v) {
1181                                 pol = NULL;
1182                                 goto out;
1183                         }
1184                         err = security_xfrm_policy_lookup(pol->security,
1185                                                       fl->flowi_secid,
1186                                                       dir);
1187                         if (!err) {
1188                                 if (!xfrm_pol_hold_rcu(pol))
1189                                         goto again;
1190                         } else if (err == -ESRCH) {
1191                                 pol = NULL;
1192                         } else {
1193                                 pol = ERR_PTR(err);
1194                         }
1195                 } else
1196                         pol = NULL;
1197         }
1198 out:
1199         rcu_read_unlock();
1200         return pol;
1201 }
1202 
1203 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
1204 {
1205         struct net *net = xp_net(pol);
1206 
1207         list_add(&pol->walk.all, &net->xfrm.policy_all);
1208         net->xfrm.policy_count[dir]++;
1209         xfrm_pol_hold(pol);
1210 }
1211 
1212 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
1213                                                 int dir)
1214 {
1215         struct net *net = xp_net(pol);
1216 
1217         if (list_empty(&pol->walk.all))
1218                 return NULL;
1219 
1220         /* Socket policies are not hashed. */
1221         if (!hlist_unhashed(&pol->bydst)) {
1222                 hlist_del_rcu(&pol->bydst);
1223                 hlist_del(&pol->byidx);
1224         }
1225 
1226         list_del_init(&pol->walk.all);
1227         net->xfrm.policy_count[dir]--;
1228 
1229         return pol;
1230 }
1231 
1232 static void xfrm_sk_policy_link(struct xfrm_policy *pol, int dir)
1233 {
1234         __xfrm_policy_link(pol, XFRM_POLICY_MAX + dir);
1235 }
1236 
1237 static void xfrm_sk_policy_unlink(struct xfrm_policy *pol, int dir)
1238 {
1239         __xfrm_policy_unlink(pol, XFRM_POLICY_MAX + dir);
1240 }
1241 
1242 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
1243 {
1244         struct net *net = xp_net(pol);
1245 
1246         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1247         pol = __xfrm_policy_unlink(pol, dir);
1248         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1249         if (pol) {
1250                 xfrm_policy_kill(pol);
1251                 return 0;
1252         }
1253         return -ENOENT;
1254 }
1255 EXPORT_SYMBOL(xfrm_policy_delete);
1256 
1257 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
1258 {
1259         struct net *net = sock_net(sk);
1260         struct xfrm_policy *old_pol;
1261 
1262 #ifdef CONFIG_XFRM_SUB_POLICY
1263         if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
1264                 return -EINVAL;
1265 #endif
1266 
1267         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1268         old_pol = rcu_dereference_protected(sk->sk_policy[dir],
1269                                 lockdep_is_held(&net->xfrm.xfrm_policy_lock));
1270         if (pol) {
1271                 pol->curlft.add_time = get_seconds();
1272                 pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir, 0);
1273                 xfrm_sk_policy_link(pol, dir);
1274         }
1275         rcu_assign_pointer(sk->sk_policy[dir], pol);
1276         if (old_pol) {
1277                 if (pol)
1278                         xfrm_policy_requeue(old_pol, pol);
1279 
1280                 /* Unlinking succeeds always. This is the only function
1281                  * allowed to delete or replace socket policy.
1282                  */
1283                 xfrm_sk_policy_unlink(old_pol, dir);
1284         }
1285         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1286 
1287         if (old_pol) {
1288                 xfrm_policy_kill(old_pol);
1289         }
1290         return 0;
1291 }
1292 
1293 static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
1294 {
1295         struct xfrm_policy *newp = xfrm_policy_alloc(xp_net(old), GFP_ATOMIC);
1296         struct net *net = xp_net(old);
1297 
1298         if (newp) {
1299                 newp->selector = old->selector;
1300                 if (security_xfrm_policy_clone(old->security,
1301                                                &newp->security)) {
1302                         kfree(newp);
1303                         return NULL;  /* ENOMEM */
1304                 }
1305                 newp->lft = old->lft;
1306                 newp->curlft = old->curlft;
1307                 newp->mark = old->mark;
1308                 newp->action = old->action;
1309                 newp->flags = old->flags;
1310                 newp->xfrm_nr = old->xfrm_nr;
1311                 newp->index = old->index;
1312                 newp->type = old->type;
1313                 newp->family = old->family;
1314                 memcpy(newp->xfrm_vec, old->xfrm_vec,
1315                        newp->xfrm_nr*sizeof(struct xfrm_tmpl));
1316                 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1317                 xfrm_sk_policy_link(newp, dir);
1318                 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1319                 xfrm_pol_put(newp);
1320         }
1321         return newp;
1322 }
1323 
1324 int __xfrm_sk_clone_policy(struct sock *sk, const struct sock *osk)
1325 {
1326         const struct xfrm_policy *p;
1327         struct xfrm_policy *np;
1328         int i, ret = 0;
1329 
1330         rcu_read_lock();
1331         for (i = 0; i < 2; i++) {
1332                 p = rcu_dereference(osk->sk_policy[i]);
1333                 if (p) {
1334                         np = clone_policy(p, i);
1335                         if (unlikely(!np)) {
1336                                 ret = -ENOMEM;
1337                                 break;
1338                         }
1339                         rcu_assign_pointer(sk->sk_policy[i], np);
1340                 }
1341         }
1342         rcu_read_unlock();
1343         return ret;
1344 }
1345 
1346 static int
1347 xfrm_get_saddr(struct net *net, int oif, xfrm_address_t *local,
1348                xfrm_address_t *remote, unsigned short family, u32 mark)
1349 {
1350         int err;
1351         const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1352 
1353         if (unlikely(afinfo == NULL))
1354                 return -EINVAL;
1355         err = afinfo->get_saddr(net, oif, local, remote, mark);
1356         rcu_read_unlock();
1357         return err;
1358 }
1359 
1360 /* Resolve list of templates for the flow, given policy. */
1361 
1362 static int
1363 xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
1364                       struct xfrm_state **xfrm, unsigned short family)
1365 {
1366         struct net *net = xp_net(policy);
1367         int nx;
1368         int i, error;
1369         xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
1370         xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
1371         xfrm_address_t tmp;
1372 
1373         for (nx = 0, i = 0; i < policy->xfrm_nr; i++) {
1374                 struct xfrm_state *x;
1375                 xfrm_address_t *remote = daddr;
1376                 xfrm_address_t *local  = saddr;
1377                 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
1378 
1379                 if (tmpl->mode == XFRM_MODE_TUNNEL ||
1380                     tmpl->mode == XFRM_MODE_BEET) {
1381                         remote = &tmpl->id.daddr;
1382                         local = &tmpl->saddr;
1383                         if (xfrm_addr_any(local, tmpl->encap_family)) {
1384                                 error = xfrm_get_saddr(net, fl->flowi_oif,
1385                                                        &tmp, remote,
1386                                                        tmpl->encap_family, 0);
1387                                 if (error)
1388                                         goto fail;
1389                                 local = &tmp;
1390                         }
1391                 }
1392 
1393                 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
1394 
1395                 if (x && x->km.state == XFRM_STATE_VALID) {
1396                         xfrm[nx++] = x;
1397                         daddr = remote;
1398                         saddr = local;
1399                         continue;
1400                 }
1401                 if (x) {
1402                         error = (x->km.state == XFRM_STATE_ERROR ?
1403                                  -EINVAL : -EAGAIN);
1404                         xfrm_state_put(x);
1405                 } else if (error == -ESRCH) {
1406                         error = -EAGAIN;
1407                 }
1408 
1409                 if (!tmpl->optional)
1410                         goto fail;
1411         }
1412         return nx;
1413 
1414 fail:
1415         for (nx--; nx >= 0; nx--)
1416                 xfrm_state_put(xfrm[nx]);
1417         return error;
1418 }
1419 
1420 static int
1421 xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, const struct flowi *fl,
1422                   struct xfrm_state **xfrm, unsigned short family)
1423 {
1424         struct xfrm_state *tp[XFRM_MAX_DEPTH];
1425         struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
1426         int cnx = 0;
1427         int error;
1428         int ret;
1429         int i;
1430 
1431         for (i = 0; i < npols; i++) {
1432                 if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
1433                         error = -ENOBUFS;
1434                         goto fail;
1435                 }
1436 
1437                 ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
1438                 if (ret < 0) {
1439                         error = ret;
1440                         goto fail;
1441                 } else
1442                         cnx += ret;
1443         }
1444 
1445         /* found states are sorted for outbound processing */
1446         if (npols > 1)
1447                 xfrm_state_sort(xfrm, tpp, cnx, family);
1448 
1449         return cnx;
1450 
1451  fail:
1452         for (cnx--; cnx >= 0; cnx--)
1453                 xfrm_state_put(tpp[cnx]);
1454         return error;
1455 
1456 }
1457 
1458 static int xfrm_get_tos(const struct flowi *fl, int family)
1459 {
1460         const struct xfrm_policy_afinfo *afinfo;
1461         int tos;
1462 
1463         afinfo = xfrm_policy_get_afinfo(family);
1464         if (!afinfo)
1465                 return 0;
1466 
1467         tos = afinfo->get_tos(fl);
1468 
1469         rcu_read_unlock();
1470 
1471         return tos;
1472 }
1473 
1474 static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
1475 {
1476         const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1477         struct dst_ops *dst_ops;
1478         struct xfrm_dst *xdst;
1479 
1480         if (!afinfo)
1481                 return ERR_PTR(-EINVAL);
1482 
1483         switch (family) {
1484         case AF_INET:
1485                 dst_ops = &net->xfrm.xfrm4_dst_ops;
1486                 break;
1487 #if IS_ENABLED(CONFIG_IPV6)
1488         case AF_INET6:
1489                 dst_ops = &net->xfrm.xfrm6_dst_ops;
1490                 break;
1491 #endif
1492         default:
1493                 BUG();
1494         }
1495         xdst = dst_alloc(dst_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
1496 
1497         if (likely(xdst)) {
1498                 struct dst_entry *dst = &xdst->u.dst;
1499 
1500                 memset(dst + 1, 0, sizeof(*xdst) - sizeof(*dst));
1501         } else
1502                 xdst = ERR_PTR(-ENOBUFS);
1503 
1504         rcu_read_unlock();
1505 
1506         return xdst;
1507 }
1508 
1509 static inline int xfrm_init_path(struct xfrm_dst *path, struct dst_entry *dst,
1510                                  int nfheader_len)
1511 {
1512         const struct xfrm_policy_afinfo *afinfo =
1513                 xfrm_policy_get_afinfo(dst->ops->family);
1514         int err;
1515 
1516         if (!afinfo)
1517                 return -EINVAL;
1518 
1519         err = afinfo->init_path(path, dst, nfheader_len);
1520 
1521         rcu_read_unlock();
1522 
1523         return err;
1524 }
1525 
1526 static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
1527                                 const struct flowi *fl)
1528 {
1529         const struct xfrm_policy_afinfo *afinfo =
1530                 xfrm_policy_get_afinfo(xdst->u.dst.ops->family);
1531         int err;
1532 
1533         if (!afinfo)
1534                 return -EINVAL;
1535 
1536         err = afinfo->fill_dst(xdst, dev, fl);
1537 
1538         rcu_read_unlock();
1539 
1540         return err;
1541 }
1542 
1543 
1544 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
1545  * all the metrics... Shortly, bundle a bundle.
1546  */
1547 
1548 static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
1549                                             struct xfrm_state **xfrm,
1550                                             struct xfrm_dst **bundle,
1551                                             int nx,
1552                                             const struct flowi *fl,
1553                                             struct dst_entry *dst)
1554 {
1555         struct net *net = xp_net(policy);
1556         unsigned long now = jiffies;
1557         struct net_device *dev;
1558         struct xfrm_mode *inner_mode;
1559         struct xfrm_dst *xdst_prev = NULL;
1560         struct xfrm_dst *xdst0 = NULL;
1561         int i = 0;
1562         int err;
1563         int header_len = 0;
1564         int nfheader_len = 0;
1565         int trailer_len = 0;
1566         int tos;
1567         int family = policy->selector.family;
1568         xfrm_address_t saddr, daddr;
1569 
1570         xfrm_flowi_addr_get(fl, &saddr, &daddr, family);
1571 
1572         tos = xfrm_get_tos(fl, family);
1573 
1574         dst_hold(dst);
1575 
1576         for (; i < nx; i++) {
1577                 struct xfrm_dst *xdst = xfrm_alloc_dst(net, family);
1578                 struct dst_entry *dst1 = &xdst->u.dst;
1579 
1580                 err = PTR_ERR(xdst);
1581                 if (IS_ERR(xdst)) {
1582                         dst_release(dst);
1583                         goto put_states;
1584                 }
1585 
1586                 bundle[i] = xdst;
1587                 if (!xdst_prev)
1588                         xdst0 = xdst;
1589                 else
1590                         /* Ref count is taken during xfrm_alloc_dst()
1591                          * No need to do dst_clone() on dst1
1592                          */
1593                         xfrm_dst_set_child(xdst_prev, &xdst->u.dst);
1594 
1595                 if (xfrm[i]->sel.family == AF_UNSPEC) {
1596                         inner_mode = xfrm_ip2inner_mode(xfrm[i],
1597                                                         xfrm_af2proto(family));
1598                         if (!inner_mode) {
1599                                 err = -EAFNOSUPPORT;
1600                                 dst_release(dst);
1601                                 goto put_states;
1602                         }
1603                 } else
1604                         inner_mode = xfrm[i]->inner_mode;
1605 
1606                 xdst->route = dst;
1607                 dst_copy_metrics(dst1, dst);
1608 
1609                 if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
1610                         family = xfrm[i]->props.family;
1611                         dst = xfrm_dst_lookup(xfrm[i], tos, fl->flowi_oif,
1612                                               &saddr, &daddr, family,
1613                                               xfrm[i]->props.output_mark);
1614                         err = PTR_ERR(dst);
1615                         if (IS_ERR(dst))
1616                                 goto put_states;
1617                 } else
1618                         dst_hold(dst);
1619 
1620                 dst1->xfrm = xfrm[i];
1621                 xdst->xfrm_genid = xfrm[i]->genid;
1622 
1623                 dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
1624                 dst1->flags |= DST_HOST;
1625                 dst1->lastuse = now;
1626 
1627                 dst1->input = dst_discard;
1628                 dst1->output = inner_mode->afinfo->output;
1629 
1630                 xdst_prev = xdst;
1631 
1632                 header_len += xfrm[i]->props.header_len;
1633                 if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
1634                         nfheader_len += xfrm[i]->props.header_len;
1635                 trailer_len += xfrm[i]->props.trailer_len;
1636         }
1637 
1638         xfrm_dst_set_child(xdst_prev, dst);
1639         xdst0->path = dst;
1640 
1641         err = -ENODEV;
1642         dev = dst->dev;
1643         if (!dev)
1644                 goto free_dst;
1645 
1646         xfrm_init_path(xdst0, dst, nfheader_len);
1647         xfrm_init_pmtu(bundle, nx);
1648 
1649         for (xdst_prev = xdst0; xdst_prev != (struct xfrm_dst *)dst;
1650              xdst_prev = (struct xfrm_dst *) xfrm_dst_child(&xdst_prev->u.dst)) {
1651                 err = xfrm_fill_dst(xdst_prev, dev, fl);
1652                 if (err)
1653                         goto free_dst;
1654 
1655                 xdst_prev->u.dst.header_len = header_len;
1656                 xdst_prev->u.dst.trailer_len = trailer_len;
1657                 header_len -= xdst_prev->u.dst.xfrm->props.header_len;
1658                 trailer_len -= xdst_prev->u.dst.xfrm->props.trailer_len;
1659         }
1660 
1661         return &xdst0->u.dst;
1662 
1663 put_states:
1664         for (; i < nx; i++)
1665                 xfrm_state_put(xfrm[i]);
1666 free_dst:
1667         if (xdst0)
1668                 dst_release_immediate(&xdst0->u.dst);
1669 
1670         return ERR_PTR(err);
1671 }
1672 
1673 static int xfrm_expand_policies(const struct flowi *fl, u16 family,
1674                                 struct xfrm_policy **pols,
1675                                 int *num_pols, int *num_xfrms)
1676 {
1677         int i;
1678 
1679         if (*num_pols == 0 || !pols[0]) {
1680                 *num_pols = 0;
1681                 *num_xfrms = 0;
1682                 return 0;
1683         }
1684         if (IS_ERR(pols[0]))
1685                 return PTR_ERR(pols[0]);
1686 
1687         *num_xfrms = pols[0]->xfrm_nr;
1688 
1689 #ifdef CONFIG_XFRM_SUB_POLICY
1690         if (pols[0] && pols[0]->action == XFRM_POLICY_ALLOW &&
1691             pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1692                 pols[1] = xfrm_policy_lookup_bytype(xp_net(pols[0]),
1693                                                     XFRM_POLICY_TYPE_MAIN,
1694                                                     fl, family,
1695                                                     XFRM_POLICY_OUT);
1696                 if (pols[1]) {
1697                         if (IS_ERR(pols[1])) {
1698                                 xfrm_pols_put(pols, *num_pols);
1699                                 return PTR_ERR(pols[1]);
1700                         }
1701                         (*num_pols)++;
1702                         (*num_xfrms) += pols[1]->xfrm_nr;
1703                 }
1704         }
1705 #endif
1706         for (i = 0; i < *num_pols; i++) {
1707                 if (pols[i]->action != XFRM_POLICY_ALLOW) {
1708                         *num_xfrms = -1;
1709                         break;
1710                 }
1711         }
1712 
1713         return 0;
1714 
1715 }
1716 
1717 static void xfrm_last_dst_update(struct xfrm_dst *xdst, struct xfrm_dst *old)
1718 {
1719         this_cpu_write(xfrm_last_dst, xdst);
1720         if (old)
1721                 dst_release(&old->u.dst);
1722 }
1723 
1724 static void __xfrm_pcpu_work_fn(void)
1725 {
1726         struct xfrm_dst *old;
1727 
1728         old = this_cpu_read(xfrm_last_dst);
1729         if (old && !xfrm_bundle_ok(old))
1730                 xfrm_last_dst_update(NULL, old);
1731 }
1732 
1733 static void xfrm_pcpu_work_fn(struct work_struct *work)
1734 {
1735         local_bh_disable();
1736         rcu_read_lock();
1737         __xfrm_pcpu_work_fn();
1738         rcu_read_unlock();
1739         local_bh_enable();
1740 }
1741 
1742 void xfrm_policy_cache_flush(void)
1743 {
1744         struct xfrm_dst *old;
1745         bool found = false;
1746         int cpu;
1747 
1748         might_sleep();
1749 
1750         local_bh_disable();
1751         rcu_read_lock();
1752         for_each_possible_cpu(cpu) {
1753                 old = per_cpu(xfrm_last_dst, cpu);
1754                 if (old && !xfrm_bundle_ok(old)) {
1755                         if (smp_processor_id() == cpu) {
1756                                 __xfrm_pcpu_work_fn();
1757                                 continue;
1758                         }
1759                         found = true;
1760                         break;
1761                 }
1762         }
1763 
1764         rcu_read_unlock();
1765         local_bh_enable();
1766 
1767         if (!found)
1768                 return;
1769 
1770         get_online_cpus();
1771 
1772         for_each_possible_cpu(cpu) {
1773                 bool bundle_release;
1774 
1775                 rcu_read_lock();
1776                 old = per_cpu(xfrm_last_dst, cpu);
1777                 bundle_release = old && !xfrm_bundle_ok(old);
1778                 rcu_read_unlock();
1779 
1780                 if (!bundle_release)
1781                         continue;
1782 
1783                 if (cpu_online(cpu)) {
1784                         schedule_work_on(cpu, &xfrm_pcpu_work[cpu]);
1785                         continue;
1786                 }
1787 
1788                 rcu_read_lock();
1789                 old = per_cpu(xfrm_last_dst, cpu);
1790                 if (old && !xfrm_bundle_ok(old)) {
1791                         per_cpu(xfrm_last_dst, cpu) = NULL;
1792                         dst_release(&old->u.dst);
1793                 }
1794                 rcu_read_unlock();
1795         }
1796 
1797         put_online_cpus();
1798 }
1799 
1800 static bool xfrm_xdst_can_reuse(struct xfrm_dst *xdst,
1801                                 struct xfrm_state * const xfrm[],
1802                                 int num)
1803 {
1804         const struct dst_entry *dst = &xdst->u.dst;
1805         int i;
1806 
1807         if (xdst->num_xfrms != num)
1808                 return false;
1809 
1810         for (i = 0; i < num; i++) {
1811                 if (!dst || dst->xfrm != xfrm[i])
1812                         return false;
1813                 dst = xfrm_dst_child(dst);
1814         }
1815 
1816         return xfrm_bundle_ok(xdst);
1817 }
1818 
1819 static struct xfrm_dst *
1820 xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
1821                                const struct flowi *fl, u16 family,
1822                                struct dst_entry *dst_orig)
1823 {
1824         struct net *net = xp_net(pols[0]);
1825         struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
1826         struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
1827         struct xfrm_dst *xdst, *old;
1828         struct dst_entry *dst;
1829         int err;
1830 
1831         /* Try to instantiate a bundle */
1832         err = xfrm_tmpl_resolve(pols, num_pols, fl, xfrm, family);
1833         if (err <= 0) {
1834                 if (err == 0)
1835                         return NULL;
1836 
1837                 if (err != -EAGAIN)
1838                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
1839                 return ERR_PTR(err);
1840         }
1841 
1842         xdst = this_cpu_read(xfrm_last_dst);
1843         if (xdst &&
1844             xdst->u.dst.dev == dst_orig->dev &&
1845             xdst->num_pols == num_pols &&
1846             memcmp(xdst->pols, pols,
1847                    sizeof(struct xfrm_policy *) * num_pols) == 0 &&
1848             xfrm_xdst_can_reuse(xdst, xfrm, err)) {
1849                 dst_hold(&xdst->u.dst);
1850                 xfrm_pols_put(pols, num_pols);
1851                 while (err > 0)
1852                         xfrm_state_put(xfrm[--err]);
1853                 return xdst;
1854         }
1855 
1856         old = xdst;
1857 
1858         dst = xfrm_bundle_create(pols[0], xfrm, bundle, err, fl, dst_orig);
1859         if (IS_ERR(dst)) {
1860                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR);
1861                 return ERR_CAST(dst);
1862         }
1863 
1864         xdst = (struct xfrm_dst *)dst;
1865         xdst->num_xfrms = err;
1866         xdst->num_pols = num_pols;
1867         memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
1868         xdst->policy_genid = atomic_read(&pols[0]->genid);
1869 
1870         atomic_set(&xdst->u.dst.__refcnt, 2);
1871         xfrm_last_dst_update(xdst, old);
1872 
1873         return xdst;
1874 }
1875 
1876 static void xfrm_policy_queue_process(struct timer_list *t)
1877 {
1878         struct sk_buff *skb;
1879         struct sock *sk;
1880         struct dst_entry *dst;
1881         struct xfrm_policy *pol = from_timer(pol, t, polq.hold_timer);
1882         struct net *net = xp_net(pol);
1883         struct xfrm_policy_queue *pq = &pol->polq;
1884         struct flowi fl;
1885         struct sk_buff_head list;
1886 
1887         spin_lock(&pq->hold_queue.lock);
1888         skb = skb_peek(&pq->hold_queue);
1889         if (!skb) {
1890                 spin_unlock(&pq->hold_queue.lock);
1891                 goto out;
1892         }
1893         dst = skb_dst(skb);
1894         sk = skb->sk;
1895         xfrm_decode_session(skb, &fl, dst->ops->family);
1896         spin_unlock(&pq->hold_queue.lock);
1897 
1898         dst_hold(xfrm_dst_path(dst));
1899         dst = xfrm_lookup(net, xfrm_dst_path(dst), &fl, sk, XFRM_LOOKUP_QUEUE);
1900         if (IS_ERR(dst))
1901                 goto purge_queue;
1902 
1903         if (dst->flags & DST_XFRM_QUEUE) {
1904                 dst_release(dst);
1905 
1906                 if (pq->timeout >= XFRM_QUEUE_TMO_MAX)
1907                         goto purge_queue;
1908 
1909                 pq->timeout = pq->timeout << 1;
1910                 if (!mod_timer(&pq->hold_timer, jiffies + pq->timeout))
1911                         xfrm_pol_hold(pol);
1912         goto out;
1913         }
1914 
1915         dst_release(dst);
1916 
1917         __skb_queue_head_init(&list);
1918 
1919         spin_lock(&pq->hold_queue.lock);
1920         pq->timeout = 0;
1921         skb_queue_splice_init(&pq->hold_queue, &list);
1922         spin_unlock(&pq->hold_queue.lock);
1923 
1924         while (!skb_queue_empty(&list)) {
1925                 skb = __skb_dequeue(&list);
1926 
1927                 xfrm_decode_session(skb, &fl, skb_dst(skb)->ops->family);
1928                 dst_hold(xfrm_dst_path(skb_dst(skb)));
1929                 dst = xfrm_lookup(net, xfrm_dst_path(skb_dst(skb)), &fl, skb->sk, 0);
1930                 if (IS_ERR(dst)) {
1931                         kfree_skb(skb);
1932                         continue;
1933                 }
1934 
1935                 nf_reset(skb);
1936                 skb_dst_drop(skb);
1937                 skb_dst_set(skb, dst);
1938 
1939                 dst_output(net, skb->sk, skb);
1940         }
1941 
1942 out:
1943         xfrm_pol_put(pol);
1944         return;
1945 
1946 purge_queue:
1947         pq->timeout = 0;
1948         skb_queue_purge(&pq->hold_queue);
1949         xfrm_pol_put(pol);
1950 }
1951 
1952 static int xdst_queue_output(struct net *net, struct sock *sk, struct sk_buff *skb)
1953 {
1954         unsigned long sched_next;
1955         struct dst_entry *dst = skb_dst(skb);
1956         struct xfrm_dst *xdst = (struct xfrm_dst *) dst;
1957         struct xfrm_policy *pol = xdst->pols[0];
1958         struct xfrm_policy_queue *pq = &pol->polq;
1959 
1960         if (unlikely(skb_fclone_busy(sk, skb))) {
1961                 kfree_skb(skb);
1962                 return 0;
1963         }
1964 
1965         if (pq->hold_queue.qlen > XFRM_MAX_QUEUE_LEN) {
1966                 kfree_skb(skb);
1967                 return -EAGAIN;
1968         }
1969 
1970         skb_dst_force(skb);
1971 
1972         spin_lock_bh(&pq->hold_queue.lock);
1973 
1974         if (!pq->timeout)
1975                 pq->timeout = XFRM_QUEUE_TMO_MIN;
1976 
1977         sched_next = jiffies + pq->timeout;
1978 
1979         if (del_timer(&pq->hold_timer)) {
1980                 if (time_before(pq->hold_timer.expires, sched_next))
1981                         sched_next = pq->hold_timer.expires;
1982                 xfrm_pol_put(pol);
1983         }
1984 
1985         __skb_queue_tail(&pq->hold_queue, skb);
1986         if (!mod_timer(&pq->hold_timer, sched_next))
1987                 xfrm_pol_hold(pol);
1988 
1989         spin_unlock_bh(&pq->hold_queue.lock);
1990 
1991         return 0;
1992 }
1993 
1994 static struct xfrm_dst *xfrm_create_dummy_bundle(struct net *net,
1995                                                  struct xfrm_flo *xflo,
1996                                                  const struct flowi *fl,
1997                                                  int num_xfrms,
1998                                                  u16 family)
1999 {
2000         int err;
2001         struct net_device *dev;
2002         struct dst_entry *dst;
2003         struct dst_entry *dst1;
2004         struct xfrm_dst *xdst;
2005 
2006         xdst = xfrm_alloc_dst(net, family);
2007         if (IS_ERR(xdst))
2008                 return xdst;
2009 
2010         if (!(xflo->flags & XFRM_LOOKUP_QUEUE) ||
2011             net->xfrm.sysctl_larval_drop ||
2012             num_xfrms <= 0)
2013                 return xdst;
2014 
2015         dst = xflo->dst_orig;
2016         dst1 = &xdst->u.dst;
2017         dst_hold(dst);
2018         xdst->route = dst;
2019 
2020         dst_copy_metrics(dst1, dst);
2021 
2022         dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
2023         dst1->flags |= DST_HOST | DST_XFRM_QUEUE;
2024         dst1->lastuse = jiffies;
2025 
2026         dst1->input = dst_discard;
2027         dst1->output = xdst_queue_output;
2028 
2029         dst_hold(dst);
2030         xfrm_dst_set_child(xdst, dst);
2031         xdst->path = dst;
2032 
2033         xfrm_init_path((struct xfrm_dst *)dst1, dst, 0);
2034 
2035         err = -ENODEV;
2036         dev = dst->dev;
2037         if (!dev)
2038                 goto free_dst;
2039 
2040         err = xfrm_fill_dst(xdst, dev, fl);
2041         if (err)
2042                 goto free_dst;
2043 
2044 out:
2045         return xdst;
2046 
2047 free_dst:
2048         dst_release(dst1);
2049         xdst = ERR_PTR(err);
2050         goto out;
2051 }
2052 
2053 static struct xfrm_dst *
2054 xfrm_bundle_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir, struct xfrm_flo *xflo)
2055 {
2056         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2057         int num_pols = 0, num_xfrms = 0, err;
2058         struct xfrm_dst *xdst;
2059 
2060         /* Resolve policies to use if we couldn't get them from
2061          * previous cache entry */
2062         num_pols = 1;
2063         pols[0] = xfrm_policy_lookup(net, fl, family, dir);
2064         err = xfrm_expand_policies(fl, family, pols,
2065                                            &num_pols, &num_xfrms);
2066         if (err < 0)
2067                 goto inc_error;
2068         if (num_pols == 0)
2069                 return NULL;
2070         if (num_xfrms <= 0)
2071                 goto make_dummy_bundle;
2072 
2073         local_bh_disable();
2074         xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family,
2075                                               xflo->dst_orig);
2076         local_bh_enable();
2077 
2078         if (IS_ERR(xdst)) {
2079                 err = PTR_ERR(xdst);
2080                 if (err != -EAGAIN)
2081                         goto error;
2082                 goto make_dummy_bundle;
2083         } else if (xdst == NULL) {
2084                 num_xfrms = 0;
2085                 goto make_dummy_bundle;
2086         }
2087 
2088         return xdst;
2089 
2090 make_dummy_bundle:
2091         /* We found policies, but there's no bundles to instantiate:
2092          * either because the policy blocks, has no transformations or
2093          * we could not build template (no xfrm_states).*/
2094         xdst = xfrm_create_dummy_bundle(net, xflo, fl, num_xfrms, family);
2095         if (IS_ERR(xdst)) {
2096                 xfrm_pols_put(pols, num_pols);
2097                 return ERR_CAST(xdst);
2098         }
2099         xdst->num_pols = num_pols;
2100         xdst->num_xfrms = num_xfrms;
2101         memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
2102 
2103         return xdst;
2104 
2105 inc_error:
2106         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
2107 error:
2108         xfrm_pols_put(pols, num_pols);
2109         return ERR_PTR(err);
2110 }
2111 
2112 static struct dst_entry *make_blackhole(struct net *net, u16 family,
2113                                         struct dst_entry *dst_orig)
2114 {
2115         const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2116         struct dst_entry *ret;
2117 
2118         if (!afinfo) {
2119                 dst_release(dst_orig);
2120                 return ERR_PTR(-EINVAL);
2121         } else {
2122                 ret = afinfo->blackhole_route(net, dst_orig);
2123         }
2124         rcu_read_unlock();
2125 
2126         return ret;
2127 }
2128 
2129 /* Main function: finds/creates a bundle for given flow.
2130  *
2131  * At the moment we eat a raw IP route. Mostly to speed up lookups
2132  * on interfaces with disabled IPsec.
2133  */
2134 struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
2135                               const struct flowi *fl,
2136                               const struct sock *sk, int flags)
2137 {
2138         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2139         struct xfrm_dst *xdst;
2140         struct dst_entry *dst, *route;
2141         u16 family = dst_orig->ops->family;
2142         u8 dir = XFRM_POLICY_OUT;
2143         int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
2144 
2145         dst = NULL;
2146         xdst = NULL;
2147         route = NULL;
2148 
2149         sk = sk_const_to_full_sk(sk);
2150         if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
2151                 num_pols = 1;
2152                 pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, family);
2153                 err = xfrm_expand_policies(fl, family, pols,
2154                                            &num_pols, &num_xfrms);
2155                 if (err < 0)
2156                         goto dropdst;
2157 
2158                 if (num_pols) {
2159                         if (num_xfrms <= 0) {
2160                                 drop_pols = num_pols;
2161                                 goto no_transform;
2162                         }
2163 
2164                         local_bh_disable();
2165                         xdst = xfrm_resolve_and_create_bundle(
2166                                         pols, num_pols, fl,
2167                                         family, dst_orig);
2168                         local_bh_enable();
2169 
2170                         if (IS_ERR(xdst)) {
2171                                 xfrm_pols_put(pols, num_pols);
2172                                 err = PTR_ERR(xdst);
2173                                 goto dropdst;
2174                         } else if (xdst == NULL) {
2175                                 num_xfrms = 0;
2176                                 drop_pols = num_pols;
2177                                 goto no_transform;
2178                         }
2179 
2180                         route = xdst->route;
2181                 }
2182         }
2183 
2184         if (xdst == NULL) {
2185                 struct xfrm_flo xflo;
2186 
2187                 xflo.dst_orig = dst_orig;
2188                 xflo.flags = flags;
2189 
2190                 /* To accelerate a bit...  */
2191                 if ((dst_orig->flags & DST_NOXFRM) ||
2192                     !net->xfrm.policy_count[XFRM_POLICY_OUT])
2193                         goto nopol;
2194 
2195                 xdst = xfrm_bundle_lookup(net, fl, family, dir, &xflo);
2196                 if (xdst == NULL)
2197                         goto nopol;
2198                 if (IS_ERR(xdst)) {
2199                         err = PTR_ERR(xdst);
2200                         goto dropdst;
2201                 }
2202 
2203                 num_pols = xdst->num_pols;
2204                 num_xfrms = xdst->num_xfrms;
2205                 memcpy(pols, xdst->pols, sizeof(struct xfrm_policy *) * num_pols);
2206                 route = xdst->route;
2207         }
2208 
2209         dst = &xdst->u.dst;
2210         if (route == NULL && num_xfrms > 0) {
2211                 /* The only case when xfrm_bundle_lookup() returns a
2212                  * bundle with null route, is when the template could
2213                  * not be resolved. It means policies are there, but
2214                  * bundle could not be created, since we don't yet
2215                  * have the xfrm_state's. We need to wait for KM to
2216                  * negotiate new SA's or bail out with error.*/
2217                 if (net->xfrm.sysctl_larval_drop) {
2218                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
2219                         err = -EREMOTE;
2220                         goto error;
2221                 }
2222 
2223                 err = -EAGAIN;
2224 
2225                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
2226                 goto error;
2227         }
2228 
2229 no_transform:
2230         if (num_pols == 0)
2231                 goto nopol;
2232 
2233         if ((flags & XFRM_LOOKUP_ICMP) &&
2234             !(pols[0]->flags & XFRM_POLICY_ICMP)) {
2235                 err = -ENOENT;
2236                 goto error;
2237         }
2238 
2239         for (i = 0; i < num_pols; i++)
2240                 pols[i]->curlft.use_time = get_seconds();
2241 
2242         if (num_xfrms < 0) {
2243                 /* Prohibit the flow */
2244                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLBLOCK);
2245                 err = -EPERM;
2246                 goto error;
2247         } else if (num_xfrms > 0) {
2248                 /* Flow transformed */
2249                 dst_release(dst_orig);
2250         } else {
2251                 /* Flow passes untransformed */
2252                 dst_release(dst);
2253                 dst = dst_orig;
2254         }
2255 ok:
2256         xfrm_pols_put(pols, drop_pols);
2257         if (dst && dst->xfrm &&
2258             dst->xfrm->props.mode == XFRM_MODE_TUNNEL)
2259                 dst->flags |= DST_XFRM_TUNNEL;
2260         return dst;
2261 
2262 nopol:
2263         if (!(flags & XFRM_LOOKUP_ICMP)) {
2264                 dst = dst_orig;
2265                 goto ok;
2266         }
2267         err = -ENOENT;
2268 error:
2269         dst_release(dst);
2270 dropdst:
2271         if (!(flags & XFRM_LOOKUP_KEEP_DST_REF))
2272                 dst_release(dst_orig);
2273         xfrm_pols_put(pols, drop_pols);
2274         return ERR_PTR(err);
2275 }
2276 EXPORT_SYMBOL(xfrm_lookup);
2277 
2278 /* Callers of xfrm_lookup_route() must ensure a call to dst_output().
2279  * Otherwise we may send out blackholed packets.
2280  */
2281 struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
2282                                     const struct flowi *fl,
2283                                     const struct sock *sk, int flags)
2284 {
2285         struct dst_entry *dst = xfrm_lookup(net, dst_orig, fl, sk,
2286                                             flags | XFRM_LOOKUP_QUEUE |
2287                                             XFRM_LOOKUP_KEEP_DST_REF);
2288 
2289         if (IS_ERR(dst) && PTR_ERR(dst) == -EREMOTE)
2290                 return make_blackhole(net, dst_orig->ops->family, dst_orig);
2291 
2292         if (IS_ERR(dst))
2293                 dst_release(dst_orig);
2294 
2295         return dst;
2296 }
2297 EXPORT_SYMBOL(xfrm_lookup_route);
2298 
2299 static inline int
2300 xfrm_secpath_reject(int idx, struct sk_buff *skb, const struct flowi *fl)
2301 {
2302         struct xfrm_state *x;
2303 
2304         if (!skb->sp || idx < 0 || idx >= skb->sp->len)
2305                 return 0;
2306         x = skb->sp->xvec[idx];
2307         if (!x->type->reject)
2308                 return 0;
2309         return x->type->reject(x, skb, fl);
2310 }
2311 
2312 /* When skb is transformed back to its "native" form, we have to
2313  * check policy restrictions. At the moment we make this in maximally
2314  * stupid way. Shame on me. :-) Of course, connected sockets must
2315  * have policy cached at them.
2316  */
2317 
2318 static inline int
2319 xfrm_state_ok(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x,
2320               unsigned short family)
2321 {
2322         if (xfrm_state_kern(x))
2323                 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
2324         return  x->id.proto == tmpl->id.proto &&
2325                 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
2326                 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
2327                 x->props.mode == tmpl->mode &&
2328                 (tmpl->allalgs || (tmpl->aalgos & (1<<x->props.aalgo)) ||
2329                  !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
2330                 !(x->props.mode != XFRM_MODE_TRANSPORT &&
2331                   xfrm_state_addr_cmp(tmpl, x, family));
2332 }
2333 
2334 /*
2335  * 0 or more than 0 is returned when validation is succeeded (either bypass
2336  * because of optional transport mode, or next index of the mathced secpath
2337  * state with the template.
2338  * -1 is returned when no matching template is found.
2339  * Otherwise "-2 - errored_index" is returned.
2340  */
2341 static inline int
2342 xfrm_policy_ok(const struct xfrm_tmpl *tmpl, const struct sec_path *sp, int start,
2343                unsigned short family)
2344 {
2345         int idx = start;
2346 
2347         if (tmpl->optional) {
2348                 if (tmpl->mode == XFRM_MODE_TRANSPORT)
2349                         return start;
2350         } else
2351                 start = -1;
2352         for (; idx < sp->len; idx++) {
2353                 if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
2354                         return ++idx;
2355                 if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
2356                         if (start == -1)
2357                                 start = -2-idx;
2358                         break;
2359                 }
2360         }
2361         return start;
2362 }
2363 
2364 int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
2365                           unsigned int family, int reverse)
2366 {
2367         const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2368         int err;
2369 
2370         if (unlikely(afinfo == NULL))
2371                 return -EAFNOSUPPORT;
2372 
2373         afinfo->decode_session(skb, fl, reverse);
2374         err = security_xfrm_decode_session(skb, &fl->flowi_secid);
2375         rcu_read_unlock();
2376         return err;
2377 }
2378 EXPORT_SYMBOL(__xfrm_decode_session);
2379 
2380 static inline int secpath_has_nontransport(const struct sec_path *sp, int k, int *idxp)
2381 {
2382         for (; k < sp->len; k++) {
2383                 if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
2384                         *idxp = k;
2385                         return 1;
2386                 }
2387         }
2388 
2389         return 0;
2390 }
2391 
2392 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
2393                         unsigned short family)
2394 {
2395         struct net *net = dev_net(skb->dev);
2396         struct xfrm_policy *pol;
2397         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2398         int npols = 0;
2399         int xfrm_nr;
2400         int pi;
2401         int reverse;
2402         struct flowi fl;
2403         int xerr_idx = -1;
2404 
2405         reverse = dir & ~XFRM_POLICY_MASK;
2406         dir &= XFRM_POLICY_MASK;
2407 
2408         if (__xfrm_decode_session(skb, &fl, family, reverse) < 0) {
2409                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
2410                 return 0;
2411         }
2412 
2413         nf_nat_decode_session(skb, &fl, family);
2414 
2415         /* First, check used SA against their selectors. */
2416         if (skb->sp) {
2417                 int i;
2418 
2419                 for (i = skb->sp->len-1; i >= 0; i--) {
2420                         struct xfrm_state *x = skb->sp->xvec[i];
2421                         if (!xfrm_selector_match(&x->sel, &fl, family)) {
2422                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
2423                                 return 0;
2424                         }
2425                 }
2426         }
2427 
2428         pol = NULL;
2429         sk = sk_to_full_sk(sk);
2430         if (sk && sk->sk_policy[dir]) {
2431                 pol = xfrm_sk_policy_lookup(sk, dir, &fl, family);
2432                 if (IS_ERR(pol)) {
2433                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2434                         return 0;
2435                 }
2436         }
2437 
2438         if (!pol)
2439                 pol = xfrm_policy_lookup(net, &fl, family, dir);
2440 
2441         if (IS_ERR(pol)) {
2442                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2443                 return 0;
2444         }
2445 
2446         if (!pol) {
2447                 if (skb->sp && secpath_has_nontransport(skb->sp, 0, &xerr_idx)) {
2448                         xfrm_secpath_reject(xerr_idx, skb, &fl);
2449                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
2450                         return 0;
2451                 }
2452                 return 1;
2453         }
2454 
2455         pol->curlft.use_time = get_seconds();
2456 
2457         pols[0] = pol;
2458         npols++;
2459 #ifdef CONFIG_XFRM_SUB_POLICY
2460         if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
2461                 pols[1] = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN,
2462                                                     &fl, family,
2463                                                     XFRM_POLICY_IN);
2464                 if (pols[1]) {
2465                         if (IS_ERR(pols[1])) {
2466                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2467                                 return 0;
2468                         }
2469                         pols[1]->curlft.use_time = get_seconds();
2470                         npols++;
2471                 }
2472         }
2473 #endif
2474 
2475         if (pol->action == XFRM_POLICY_ALLOW) {
2476                 struct sec_path *sp;
2477                 static struct sec_path dummy;
2478                 struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
2479                 struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
2480                 struct xfrm_tmpl **tpp = tp;
2481                 int ti = 0;
2482                 int i, k;
2483 
2484                 if ((sp = skb->sp) == NULL)
2485                         sp = &dummy;
2486 
2487                 for (pi = 0; pi < npols; pi++) {
2488                         if (pols[pi] != pol &&
2489                             pols[pi]->action != XFRM_POLICY_ALLOW) {
2490                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2491                                 goto reject;
2492                         }
2493                         if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH) {
2494                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
2495                                 goto reject_error;
2496                         }
2497                         for (i = 0; i < pols[pi]->xfrm_nr; i++)
2498                                 tpp[ti++] = &pols[pi]->xfrm_vec[i];
2499                 }
2500                 xfrm_nr = ti;
2501                 if (npols > 1) {
2502                         xfrm_tmpl_sort(stp, tpp, xfrm_nr, family, net);
2503                         tpp = stp;
2504                 }
2505 
2506                 /* For each tunnel xfrm, find the first matching tmpl.
2507                  * For each tmpl before that, find corresponding xfrm.
2508                  * Order is _important_. Later we will implement
2509                  * some barriers, but at the moment barriers
2510                  * are implied between each two transformations.
2511                  */
2512                 for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
2513                         k = xfrm_policy_ok(tpp[i], sp, k, family);
2514                         if (k < 0) {
2515                                 if (k < -1)
2516                                         /* "-2 - errored_index" returned */
2517                                         xerr_idx = -(2+k);
2518                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2519                                 goto reject;
2520                         }
2521                 }
2522 
2523                 if (secpath_has_nontransport(sp, k, &xerr_idx)) {
2524                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2525                         goto reject;
2526                 }
2527 
2528                 xfrm_pols_put(pols, npols);
2529                 return 1;
2530         }
2531         XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2532 
2533 reject:
2534         xfrm_secpath_reject(xerr_idx, skb, &fl);
2535 reject_error:
2536         xfrm_pols_put(pols, npols);
2537         return 0;
2538 }
2539 EXPORT_SYMBOL(__xfrm_policy_check);
2540 
2541 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
2542 {
2543         struct net *net = dev_net(skb->dev);
2544         struct flowi fl;
2545         struct dst_entry *dst;
2546         int res = 1;
2547 
2548         if (xfrm_decode_session(skb, &fl, family) < 0) {
2549                 XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
2550                 return 0;
2551         }
2552 
2553         skb_dst_force(skb);
2554         if (!skb_dst(skb)) {
2555                 XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
2556                 return 0;
2557         }
2558 
2559         dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, XFRM_LOOKUP_QUEUE);
2560         if (IS_ERR(dst)) {
2561                 res = 0;
2562                 dst = NULL;
2563         }
2564         skb_dst_set(skb, dst);
2565         return res;
2566 }
2567 EXPORT_SYMBOL(__xfrm_route_forward);
2568 
2569 /* Optimize later using cookies and generation ids. */
2570 
2571 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
2572 {
2573         /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
2574          * to DST_OBSOLETE_FORCE_CHK to force all XFRM destinations to
2575          * get validated by dst_ops->check on every use.  We do this
2576          * because when a normal route referenced by an XFRM dst is
2577          * obsoleted we do not go looking around for all parent
2578          * referencing XFRM dsts so that we can invalidate them.  It
2579          * is just too much work.  Instead we make the checks here on
2580          * every use.  For example:
2581          *
2582          *      XFRM dst A --> IPv4 dst X
2583          *
2584          * X is the "xdst->route" of A (X is also the "dst->path" of A
2585          * in this example).  If X is marked obsolete, "A" will not
2586          * notice.  That's what we are validating here via the
2587          * stale_bundle() check.
2588          *
2589          * When a dst is removed from the fib tree, DST_OBSOLETE_DEAD will
2590          * be marked on it.
2591          * This will force stale_bundle() to fail on any xdst bundle with
2592          * this dst linked in it.
2593          */
2594         if (dst->obsolete < 0 && !stale_bundle(dst))
2595                 return dst;
2596 
2597         return NULL;
2598 }
2599 
2600 static int stale_bundle(struct dst_entry *dst)
2601 {
2602         return !xfrm_bundle_ok((struct xfrm_dst *)dst);
2603 }
2604 
2605 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
2606 {
2607         while ((dst = xfrm_dst_child(dst)) && dst->xfrm && dst->dev == dev) {
2608                 dst->dev = dev_net(dev)->loopback_dev;
2609                 dev_hold(dst->dev);
2610                 dev_put(dev);
2611         }
2612 }
2613 EXPORT_SYMBOL(xfrm_dst_ifdown);
2614 
2615 static void xfrm_link_failure(struct sk_buff *skb)
2616 {
2617         /* Impossible. Such dst must be popped before reaches point of failure. */
2618 }
2619 
2620 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
2621 {
2622         if (dst) {
2623                 if (dst->obsolete) {
2624                         dst_release(dst);
2625                         dst = NULL;
2626                 }
2627         }
2628         return dst;
2629 }
2630 
2631 static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr)
2632 {
2633         while (nr--) {
2634                 struct xfrm_dst *xdst = bundle[nr];
2635                 u32 pmtu, route_mtu_cached;
2636                 struct dst_entry *dst;
2637 
2638                 dst = &xdst->u.dst;
2639                 pmtu = dst_mtu(xfrm_dst_child(dst));
2640                 xdst->child_mtu_cached = pmtu;
2641 
2642                 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
2643 
2644                 route_mtu_cached = dst_mtu(xdst->route);
2645                 xdst->route_mtu_cached = route_mtu_cached;
2646 
2647                 if (pmtu > route_mtu_cached)
2648                         pmtu = route_mtu_cached;
2649 
2650                 dst_metric_set(dst, RTAX_MTU, pmtu);
2651         }
2652 }
2653 
2654 /* Check that the bundle accepts the flow and its components are
2655  * still valid.
2656  */
2657 
2658 static int xfrm_bundle_ok(struct xfrm_dst *first)
2659 {
2660         struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
2661         struct dst_entry *dst = &first->u.dst;
2662         struct xfrm_dst *xdst;
2663         int start_from, nr;
2664         u32 mtu;
2665 
2666         if (!dst_check(xfrm_dst_path(dst), ((struct xfrm_dst *)dst)->path_cookie) ||
2667             (dst->dev && !netif_running(dst->dev)))
2668                 return 0;
2669 
2670         if (dst->flags & DST_XFRM_QUEUE)
2671                 return 1;
2672 
2673         start_from = nr = 0;
2674         do {
2675                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2676 
2677                 if (dst->xfrm->km.state != XFRM_STATE_VALID)
2678                         return 0;
2679                 if (xdst->xfrm_genid != dst->xfrm->genid)
2680                         return 0;
2681                 if (xdst->num_pols > 0 &&
2682                     xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
2683                         return 0;
2684 
2685                 bundle[nr++] = xdst;
2686 
2687                 mtu = dst_mtu(xfrm_dst_child(dst));
2688                 if (xdst->child_mtu_cached != mtu) {
2689                         start_from = nr;
2690                         xdst->child_mtu_cached = mtu;
2691                 }
2692 
2693                 if (!dst_check(xdst->route, xdst->route_cookie))
2694                         return 0;
2695                 mtu = dst_mtu(xdst->route);
2696                 if (xdst->route_mtu_cached != mtu) {
2697                         start_from = nr;
2698                         xdst->route_mtu_cached = mtu;
2699                 }
2700 
2701                 dst = xfrm_dst_child(dst);
2702         } while (dst->xfrm);
2703 
2704         if (likely(!start_from))
2705                 return 1;
2706 
2707         xdst = bundle[start_from - 1];
2708         mtu = xdst->child_mtu_cached;
2709         while (start_from--) {
2710                 dst = &xdst->u.dst;
2711 
2712                 mtu = xfrm_state_mtu(dst->xfrm, mtu);
2713                 if (mtu > xdst->route_mtu_cached)
2714                         mtu = xdst->route_mtu_cached;
2715                 dst_metric_set(dst, RTAX_MTU, mtu);
2716                 if (!start_from)
2717                         break;
2718 
2719                 xdst = bundle[start_from - 1];
2720                 xdst->child_mtu_cached = mtu;
2721         }
2722 
2723         return 1;
2724 }
2725 
2726 static unsigned int xfrm_default_advmss(const struct dst_entry *dst)
2727 {
2728         return dst_metric_advmss(xfrm_dst_path(dst));
2729 }
2730 
2731 static unsigned int xfrm_mtu(const struct dst_entry *dst)
2732 {
2733         unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2734 
2735         return mtu ? : dst_mtu(xfrm_dst_path(dst));
2736 }
2737 
2738 static const void *xfrm_get_dst_nexthop(const struct dst_entry *dst,
2739                                         const void *daddr)
2740 {
2741         while (dst->xfrm) {
2742                 const struct xfrm_state *xfrm = dst->xfrm;
2743 
2744                 dst = xfrm_dst_child(dst);
2745 
2746                 if (xfrm->props.mode == XFRM_MODE_TRANSPORT)
2747                         continue;
2748                 if (xfrm->type->flags & XFRM_TYPE_REMOTE_COADDR)
2749                         daddr = xfrm->coaddr;
2750                 else if (!(xfrm->type->flags & XFRM_TYPE_LOCAL_COADDR))
2751                         daddr = &xfrm->id.daddr;
2752         }
2753         return daddr;
2754 }
2755 
2756 static struct neighbour *xfrm_neigh_lookup(const struct dst_entry *dst,
2757                                            struct sk_buff *skb,
2758                                            const void *daddr)
2759 {
2760         const struct dst_entry *path = xfrm_dst_path(dst);
2761 
2762         if (!skb)
2763                 daddr = xfrm_get_dst_nexthop(dst, daddr);
2764         return path->ops->neigh_lookup(path, skb, daddr);
2765 }
2766 
2767 static void xfrm_confirm_neigh(const struct dst_entry *dst, const void *daddr)
2768 {
2769         const struct dst_entry *path = xfrm_dst_path(dst);
2770 
2771         daddr = xfrm_get_dst_nexthop(dst, daddr);
2772         path->ops->confirm_neigh(path, daddr);
2773 }
2774 
2775 int xfrm_policy_register_afinfo(const struct xfrm_policy_afinfo *afinfo, int family)
2776 {
2777         int err = 0;
2778 
2779         if (WARN_ON(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
2780                 return -EAFNOSUPPORT;
2781 
2782         spin_lock(&xfrm_policy_afinfo_lock);
2783         if (unlikely(xfrm_policy_afinfo[family] != NULL))
2784                 err = -EEXIST;
2785         else {
2786                 struct dst_ops *dst_ops = afinfo->dst_ops;
2787                 if (likely(dst_ops->kmem_cachep == NULL))
2788                         dst_ops->kmem_cachep = xfrm_dst_cache;
2789                 if (likely(dst_ops->check == NULL))
2790                         dst_ops->check = xfrm_dst_check;
2791                 if (likely(dst_ops->default_advmss == NULL))
2792                         dst_ops->default_advmss = xfrm_default_advmss;
2793                 if (likely(dst_ops->mtu == NULL))
2794                         dst_ops->mtu = xfrm_mtu;
2795                 if (likely(dst_ops->negative_advice == NULL))
2796                         dst_ops->negative_advice = xfrm_negative_advice;
2797                 if (likely(dst_ops->link_failure == NULL))
2798                         dst_ops->link_failure = xfrm_link_failure;
2799                 if (likely(dst_ops->neigh_lookup == NULL))
2800                         dst_ops->neigh_lookup = xfrm_neigh_lookup;
2801                 if (likely(!dst_ops->confirm_neigh))
2802                         dst_ops->confirm_neigh = xfrm_confirm_neigh;
2803                 rcu_assign_pointer(xfrm_policy_afinfo[family], afinfo);
2804         }
2805         spin_unlock(&xfrm_policy_afinfo_lock);
2806 
2807         return err;
2808 }
2809 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
2810 
2811 void xfrm_policy_unregister_afinfo(const struct xfrm_policy_afinfo *afinfo)
2812 {
2813         struct dst_ops *dst_ops = afinfo->dst_ops;
2814         int i;
2815 
2816         for (i = 0; i < ARRAY_SIZE(xfrm_policy_afinfo); i++) {
2817                 if (xfrm_policy_afinfo[i] != afinfo)
2818                         continue;
2819                 RCU_INIT_POINTER(xfrm_policy_afinfo[i], NULL);
2820                 break;
2821         }
2822 
2823         synchronize_rcu();
2824 
2825         dst_ops->kmem_cachep = NULL;
2826         dst_ops->check = NULL;
2827         dst_ops->negative_advice = NULL;
2828         dst_ops->link_failure = NULL;
2829 }
2830 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
2831 
2832 #ifdef CONFIG_XFRM_STATISTICS
2833 static int __net_init xfrm_statistics_init(struct net *net)
2834 {
2835         int rv;
2836         net->mib.xfrm_statistics = alloc_percpu(struct linux_xfrm_mib);
2837         if (!net->mib.xfrm_statistics)
2838                 return -ENOMEM;
2839         rv = xfrm_proc_init(net);
2840         if (rv < 0)
2841                 free_percpu(net->mib.xfrm_statistics);
2842         return rv;
2843 }
2844 
2845 static void xfrm_statistics_fini(struct net *net)
2846 {
2847         xfrm_proc_fini(net);
2848         free_percpu(net->mib.xfrm_statistics);
2849 }
2850 #else
2851 static int __net_init xfrm_statistics_init(struct net *net)
2852 {
2853         return 0;
2854 }
2855 
2856 static void xfrm_statistics_fini(struct net *net)
2857 {
2858 }
2859 #endif
2860 
2861 static int __net_init xfrm_policy_init(struct net *net)
2862 {
2863         unsigned int hmask, sz;
2864         int dir;
2865 
2866         if (net_eq(net, &init_net))
2867                 xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
2868                                            sizeof(struct xfrm_dst),
2869                                            0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
2870                                            NULL);
2871 
2872         hmask = 8 - 1;
2873         sz = (hmask+1) * sizeof(struct hlist_head);
2874 
2875         net->xfrm.policy_byidx = xfrm_hash_alloc(sz);
2876         if (!net->xfrm.policy_byidx)
2877                 goto out_byidx;
2878         net->xfrm.policy_idx_hmask = hmask;
2879 
2880         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
2881                 struct xfrm_policy_hash *htab;
2882 
2883                 net->xfrm.policy_count[dir] = 0;
2884                 net->xfrm.policy_count[XFRM_POLICY_MAX + dir] = 0;
2885                 INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
2886 
2887                 htab = &net->xfrm.policy_bydst[dir];
2888                 htab->table = xfrm_hash_alloc(sz);
2889                 if (!htab->table)
2890                         goto out_bydst;
2891                 htab->hmask = hmask;
2892                 htab->dbits4 = 32;
2893                 htab->sbits4 = 32;
2894                 htab->dbits6 = 128;
2895                 htab->sbits6 = 128;
2896         }
2897         net->xfrm.policy_hthresh.lbits4 = 32;
2898         net->xfrm.policy_hthresh.rbits4 = 32;
2899         net->xfrm.policy_hthresh.lbits6 = 128;
2900         net->xfrm.policy_hthresh.rbits6 = 128;
2901 
2902         seqlock_init(&net->xfrm.policy_hthresh.lock);
2903 
2904         INIT_LIST_HEAD(&net->xfrm.policy_all);
2905         INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
2906         INIT_WORK(&net->xfrm.policy_hthresh.work, xfrm_hash_rebuild);
2907         return 0;
2908 
2909 out_bydst:
2910         for (dir--; dir >= 0; dir--) {
2911                 struct xfrm_policy_hash *htab;
2912 
2913                 htab = &net->xfrm.policy_bydst[dir];
2914                 xfrm_hash_free(htab->table, sz);
2915         }
2916         xfrm_hash_free(net->xfrm.policy_byidx, sz);
2917 out_byidx:
2918         return -ENOMEM;
2919 }
2920 
2921 static void xfrm_policy_fini(struct net *net)
2922 {
2923         unsigned int sz;
2924         int dir;
2925 
2926         flush_work(&net->xfrm.policy_hash_work);
2927 #ifdef CONFIG_XFRM_SUB_POLICY
2928         xfrm_policy_flush(net, XFRM_POLICY_TYPE_SUB, false);
2929 #endif
2930         xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, false);
2931 
2932         WARN_ON(!list_empty(&net->xfrm.policy_all));
2933 
2934         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
2935                 struct xfrm_policy_hash *htab;
2936 
2937                 WARN_ON(!hlist_empty(&net->xfrm.policy_inexact[dir]));
2938 
2939                 htab = &net->xfrm.policy_bydst[dir];
2940                 sz = (htab->hmask + 1) * sizeof(struct hlist_head);
2941                 WARN_ON(!hlist_empty(htab->table));
2942                 xfrm_hash_free(htab->table, sz);
2943         }
2944 
2945         sz = (net->xfrm.policy_idx_hmask + 1) * sizeof(struct hlist_head);
2946         WARN_ON(!hlist_empty(net->xfrm.policy_byidx));
2947         xfrm_hash_free(net->xfrm.policy_byidx, sz);
2948 }
2949 
2950 static int __net_init xfrm_net_init(struct net *net)
2951 {
2952         int rv;
2953 
2954         /* Initialize the per-net locks here */
2955         spin_lock_init(&net->xfrm.xfrm_state_lock);
2956         spin_lock_init(&net->xfrm.xfrm_policy_lock);
2957         mutex_init(&net->xfrm.xfrm_cfg_mutex);
2958 
2959         rv = xfrm_statistics_init(net);
2960         if (rv < 0)
2961                 goto out_statistics;
2962         rv = xfrm_state_init(net);
2963         if (rv < 0)
2964                 goto out_state;
2965         rv = xfrm_policy_init(net);
2966         if (rv < 0)
2967                 goto out_policy;
2968         rv = xfrm_sysctl_init(net);
2969         if (rv < 0)
2970                 goto out_sysctl;
2971 
2972         return 0;
2973 
2974 out_sysctl:
2975         xfrm_policy_fini(net);
2976 out_policy:
2977         xfrm_state_fini(net);
2978 out_state:
2979         xfrm_statistics_fini(net);
2980 out_statistics:
2981         return rv;
2982 }
2983 
2984 static void __net_exit xfrm_net_exit(struct net *net)
2985 {
2986         xfrm_sysctl_fini(net);
2987         xfrm_policy_fini(net);
2988         xfrm_state_fini(net);
2989         xfrm_statistics_fini(net);
2990 }
2991 
2992 static struct pernet_operations __net_initdata xfrm_net_ops = {
2993         .init = xfrm_net_init,
2994         .exit = xfrm_net_exit,
2995 };
2996 
2997 void __init xfrm_init(void)
2998 {
2999         int i;
3000 
3001         xfrm_pcpu_work = kmalloc_array(NR_CPUS, sizeof(*xfrm_pcpu_work),
3002                                        GFP_KERNEL);
3003         BUG_ON(!xfrm_pcpu_work);
3004 
3005         for (i = 0; i < NR_CPUS; i++)
3006                 INIT_WORK(&xfrm_pcpu_work[i], xfrm_pcpu_work_fn);
3007 
3008         register_pernet_subsys(&xfrm_net_ops);
3009         xfrm_dev_init();
3010         seqcount_init(&xfrm_policy_hash_generation);
3011         xfrm_input_init();
3012 }
3013 
3014 #ifdef CONFIG_AUDITSYSCALL
3015 static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
3016                                          struct audit_buffer *audit_buf)
3017 {
3018         struct xfrm_sec_ctx *ctx = xp->security;
3019         struct xfrm_selector *sel = &xp->selector;
3020 
3021         if (ctx)
3022                 audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
3023                                  ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str);
3024 
3025         switch (sel->family) {
3026         case AF_INET:
3027                 audit_log_format(audit_buf, " src=%pI4", &sel->saddr.a4);
3028                 if (sel->prefixlen_s != 32)
3029                         audit_log_format(audit_buf, " src_prefixlen=%d",
3030                                          sel->prefixlen_s);
3031                 audit_log_format(audit_buf, " dst=%pI4", &sel->daddr.a4);
3032                 if (sel->prefixlen_d != 32)
3033                         audit_log_format(audit_buf, " dst_prefixlen=%d",
3034                                          sel->prefixlen_d);
3035                 break;
3036         case AF_INET6:
3037                 audit_log_format(audit_buf, " src=%pI6", sel->saddr.a6);
3038                 if (sel->prefixlen_s != 128)
3039                         audit_log_format(audit_buf, " src_prefixlen=%d",
3040                                          sel->prefixlen_s);
3041                 audit_log_format(audit_buf, " dst=%pI6", sel->daddr.a6);
3042                 if (sel->prefixlen_d != 128)
3043                         audit_log_format(audit_buf, " dst_prefixlen=%d",
3044                                          sel->prefixlen_d);
3045                 break;
3046         }
3047 }
3048 
3049 void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid)
3050 {
3051         struct audit_buffer *audit_buf;
3052 
3053         audit_buf = xfrm_audit_start("SPD-add");
3054         if (audit_buf == NULL)
3055                 return;
3056         xfrm_audit_helper_usrinfo(task_valid, audit_buf);
3057         audit_log_format(audit_buf, " res=%u", result);
3058         xfrm_audit_common_policyinfo(xp, audit_buf);
3059         audit_log_end(audit_buf);
3060 }
3061 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
3062 
3063 void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
3064                               bool task_valid)
3065 {
3066         struct audit_buffer *audit_buf;
3067 
3068         audit_buf = xfrm_audit_start("SPD-delete");
3069         if (audit_buf == NULL)
3070                 return;
3071         xfrm_audit_helper_usrinfo(task_valid, audit_buf);
3072         audit_log_format(audit_buf, " res=%u", result);
3073         xfrm_audit_common_policyinfo(xp, audit_buf);
3074         audit_log_end(audit_buf);
3075 }
3076 EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
3077 #endif
3078 
3079 #ifdef CONFIG_XFRM_MIGRATE
3080 static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp,
3081                                         const struct xfrm_selector *sel_tgt)
3082 {
3083         if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
3084                 if (sel_tgt->family == sel_cmp->family &&
3085                     xfrm_addr_equal(&sel_tgt->daddr, &sel_cmp->daddr,
3086                                     sel_cmp->family) &&
3087                     xfrm_addr_equal(&sel_tgt->saddr, &sel_cmp->saddr,
3088                                     sel_cmp->family) &&
3089                     sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
3090                     sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
3091                         return true;
3092                 }
3093         } else {
3094                 if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
3095                         return true;
3096                 }
3097         }
3098         return false;
3099 }
3100 
3101 static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector *sel,
3102                                                     u8 dir, u8 type, struct net *net)
3103 {
3104         struct xfrm_policy *pol, *ret = NULL;
3105         struct hlist_head *chain;
3106         u32 priority = ~0U;
3107 
3108         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
3109         chain = policy_hash_direct(net, &sel->daddr, &sel->saddr, sel->family, dir);
3110         hlist_for_each_entry(pol, chain, bydst) {
3111                 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
3112                     pol->type == type) {
3113                         ret = pol;
3114                         priority = ret->priority;
3115                         break;
3116                 }
3117         }
3118         chain = &net->xfrm.policy_inexact[dir];
3119         hlist_for_each_entry(pol, chain, bydst) {
3120                 if ((pol->priority >= priority) && ret)
3121                         break;
3122 
3123                 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
3124                     pol->type == type) {
3125                         ret = pol;
3126                         break;
3127                 }
3128         }
3129 
3130         xfrm_pol_hold(ret);
3131 
3132         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
3133 
3134         return ret;
3135 }
3136 
3137 static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t)
3138 {
3139         int match = 0;
3140 
3141         if (t->mode == m->mode && t->id.proto == m->proto &&
3142             (m->reqid == 0 || t->reqid == m->reqid)) {
3143                 switch (t->mode) {
3144                 case XFRM_MODE_TUNNEL:
3145                 case XFRM_MODE_BEET:
3146                         if (xfrm_addr_equal(&t->id.daddr, &m->old_daddr,
3147                                             m->old_family) &&
3148                             xfrm_addr_equal(&t->saddr, &m->old_saddr,
3149                                             m->old_family)) {
3150                                 match = 1;
3151                         }
3152                         break;
3153                 case XFRM_MODE_TRANSPORT:
3154                         /* in case of transport mode, template does not store
3155                            any IP addresses, hence we just compare mode and
3156                            protocol */
3157                         match = 1;
3158                         break;
3159                 default:
3160                         break;
3161                 }
3162         }
3163         return match;
3164 }
3165 
3166 /* update endpoint address(es) of template(s) */
3167 static int xfrm_policy_migrate(struct xfrm_policy *pol,
3168                                struct xfrm_migrate *m, int num_migrate)
3169 {
3170         struct xfrm_migrate *mp;
3171         int i, j, n = 0;
3172 
3173         write_lock_bh(&pol->lock);
3174         if (unlikely(pol->walk.dead)) {
3175                 /* target policy has been deleted */
3176                 write_unlock_bh(&pol->lock);
3177                 return -ENOENT;
3178         }
3179 
3180         for (i = 0; i < pol->xfrm_nr; i++) {
3181                 for (j = 0, mp = m; j < num_migrate; j++, mp++) {
3182                         if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
3183                                 continue;
3184                         n++;
3185                         if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
3186                             pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
3187                                 continue;
3188                         /* update endpoints */
3189                         memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
3190                                sizeof(pol->xfrm_vec[i].id.daddr));
3191                         memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
3192                                sizeof(pol->xfrm_vec[i].saddr));
3193                         pol->xfrm_vec[i].encap_family = mp->new_family;
3194                         /* flush bundles */
3195                         atomic_inc(&pol->genid);
3196                 }
3197         }
3198 
3199         write_unlock_bh(&pol->lock);
3200 
3201         if (!n)
3202                 return -ENODATA;
3203 
3204         return 0;
3205 }
3206 
3207 static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate)
3208 {
3209         int i, j;
3210 
3211         if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
3212                 return -EINVAL;
3213 
3214         for (i = 0; i < num_migrate; i++) {
3215                 if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
3216                     xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
3217                         return -EINVAL;
3218 
3219                 /* check if there is any duplicated entry */
3220                 for (j = i + 1; j < num_migrate; j++) {
3221                         if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
3222                                     sizeof(m[i].old_daddr)) &&
3223                             !memcmp(&m[i].old_saddr, &m[j].old_saddr,
3224                                     sizeof(m[i].old_saddr)) &&
3225                             m[i].proto == m[j].proto &&
3226                             m[i].mode == m[j].mode &&
3227                             m[i].reqid == m[j].reqid &&
3228                             m[i].old_family == m[j].old_family)
3229                                 return -EINVAL;
3230                 }
3231         }
3232 
3233         return 0;
3234 }
3235 
3236 int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
3237                  struct xfrm_migrate *m, int num_migrate,
3238                  struct xfrm_kmaddress *k, struct net *net,
3239                  struct xfrm_encap_tmpl *encap)
3240 {
3241         int i, err, nx_cur = 0, nx_new = 0;
3242         struct xfrm_policy *pol = NULL;
3243         struct xfrm_state *x, *xc;
3244         struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
3245         struct xfrm_state *x_new[XFRM_MAX_DEPTH];
3246         struct xfrm_migrate *mp;
3247 
3248         /* Stage 0 - sanity checks */
3249         if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
3250                 goto out;
3251 
3252         if (dir >= XFRM_POLICY_MAX) {
3253                 err = -EINVAL;
3254                 goto out;
3255         }
3256 
3257         /* Stage 1 - find policy */
3258         if ((pol = xfrm_migrate_policy_find(sel, dir, type, net)) == NULL) {
3259                 err = -ENOENT;
3260                 goto out;
3261         }
3262 
3263         /* Stage 2 - find and update state(s) */
3264         for (i = 0, mp = m; i < num_migrate; i++, mp++) {
3265                 if ((x = xfrm_migrate_state_find(mp, net))) {
3266                         x_cur[nx_cur] = x;
3267                         nx_cur++;
3268                         xc = xfrm_state_migrate(x, mp, encap);
3269                         if (xc) {
3270                                 x_new[nx_new] = xc;
3271                                 nx_new++;
3272                         } else {
3273                                 err = -ENODATA;
3274                                 goto restore_state;
3275                         }
3276                 }
3277         }
3278 
3279         /* Stage 3 - update policy */
3280         if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
3281                 goto restore_state;
3282 
3283         /* Stage 4 - delete old state(s) */
3284         if (nx_cur) {
3285                 xfrm_states_put(x_cur, nx_cur);
3286                 xfrm_states_delete(x_cur, nx_cur);
3287         }
3288 
3289         /* Stage 5 - announce */
3290         km_migrate(sel, dir, type, m, num_migrate, k, encap);
3291 
3292         xfrm_pol_put(pol);
3293 
3294         return 0;
3295 out:
3296         return err;
3297 
3298 restore_state:
3299         if (pol)
3300                 xfrm_pol_put(pol);
3301         if (nx_cur)
3302                 xfrm_states_put(x_cur, nx_cur);
3303         if (nx_new)
3304                 xfrm_states_delete(x_new, nx_new);
3305 
3306         return err;
3307 }
3308 EXPORT_SYMBOL(xfrm_migrate);
3309 #endif
3310 

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