net/xfrm/xfrm_policy.c

   1 /*
   2  * xfrm_policy.c
   3  *
   4  * Changes:
   5  *      Mitsuru KANDA @USAGI
   6  *      Kazunori MIYAZAWA @USAGI
   7  *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
   8  *              IPv6 support
   9  *      Kazunori MIYAZAWA @USAGI
  10  *      YOSHIFUJI Hideaki
  11  *              Split up af-specific portion
  12  *      Derek Atkins <derek@ihtfp.com>          Add the post_input processor
  13  *
  14  */
  15
  16 #include <linux/err.h>
  17 #include <linux/slab.h>
  18 #include <linux/kmod.h>
  19 #include <linux/list.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/workqueue.h>
  22 #include <linux/notifier.h>
  23 #include <linux/netdevice.h>
  24 #include <linux/netfilter.h>
  25 #include <linux/module.h>
  26 #include <linux/cache.h>
  27 #include <linux/audit.h>
  28 #include <net/dst.h>
  29 #include <net/flow.h>
  30 #include <net/xfrm.h>
  31 #include <net/ip.h>
  32 #ifdef CONFIG_XFRM_STATISTICS
  33 #include <net/snmp.h>
  34 #endif
  35
  36 #include "xfrm_hash.h"
  37
  38 #define XFRM_QUEUE_TMO_MIN ((unsigned)(HZ/10))
  39 #define XFRM_QUEUE_TMO_MAX ((unsigned)(60*HZ))
  40 #define XFRM_MAX_QUEUE_LEN      100
  41
  42 struct xfrm_flo {
  43         struct dst_entry *dst_orig;
  44         u8 flags;
  45 };
  46
  47 static DEFINE_SPINLOCK(xfrm_policy_afinfo_lock);
  48 static struct xfrm_policy_afinfo const __rcu *xfrm_policy_afinfo[AF_INET6 + 1]
  49                                                 __read_mostly;
  50
  51 static struct kmem_cache *xfrm_dst_cache __read_mostly;
  52 static __read_mostly seqcount_t xfrm_policy_hash_generation;
  53
  54 static void xfrm_init_pmtu(struct dst_entry *dst);
  55 static int stale_bundle(struct dst_entry *dst);
  56 static int xfrm_bundle_ok(struct xfrm_dst *xdst);
  57 static void xfrm_policy_queue_process(unsigned long arg);
  58
  59 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir);
  60 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
  61                                                 int dir);
  62
  63 static inline bool xfrm_pol_hold_rcu(struct xfrm_policy *policy)
  64 {
  65         return refcount_inc_not_zero(&policy->refcnt);
  66 }
  67
  68 static inline bool
  69 __xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
  70 {
  71         const struct flowi4 *fl4 = &fl->u.ip4;
  72
  73         return  addr4_match(fl4->daddr, sel->daddr.a4, sel->prefixlen_d) &&
  74                 addr4_match(fl4->saddr, sel->saddr.a4, sel->prefixlen_s) &&
  75                 !((xfrm_flowi_dport(fl, &fl4->uli) ^ sel->dport) & sel->dport_mask) &&
  76                 !((xfrm_flowi_sport(fl, &fl4->uli) ^ sel->sport) & sel->sport_mask) &&
  77                 (fl4->flowi4_proto == sel->proto || !sel->proto) &&
  78                 (fl4->flowi4_oif == sel->ifindex || !sel->ifindex);
  79 }
  80
  81 static inline bool
  82 __xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
  83 {
  84         const struct flowi6 *fl6 = &fl->u.ip6;
  85
  86         return  addr_match(&fl6->daddr, &sel->daddr, sel->prefixlen_d) &&
  87                 addr_match(&fl6->saddr, &sel->saddr, sel->prefixlen_s) &&
  88                 !((xfrm_flowi_dport(fl, &fl6->uli) ^ sel->dport) & sel->dport_mask) &&
  89                 !((xfrm_flowi_sport(fl, &fl6->uli) ^ sel->sport) & sel->sport_mask) &&
  90                 (fl6->flowi6_proto == sel->proto || !sel->proto) &&
  91                 (fl6->flowi6_oif == sel->ifindex || !sel->ifindex);
  92 }
  93
  94 bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl,
  95                          unsigned short family)
  96 {
  97         switch (family) {
  98         case AF_INET:
  99                 return __xfrm4_selector_match(sel, fl);
 100         case AF_INET6:
 101                 return __xfrm6_selector_match(sel, fl);
 102         }
 103         return false;
 104 }
 105
 106 static const struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
 107 {
 108         const struct xfrm_policy_afinfo *afinfo;
 109
 110         if (unlikely(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
 111                 return NULL;
 112         rcu_read_lock();
 113         afinfo = rcu_dereference(xfrm_policy_afinfo[family]);
 114         if (unlikely(!afinfo))
 115                 rcu_read_unlock();
 116         return afinfo;
 117 }
 118
 119 struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos, int oif,
 120                                     const xfrm_address_t *saddr,
 121                                     const xfrm_address_t *daddr,
 122                                     int family)
 123 {
 124         const struct xfrm_policy_afinfo *afinfo;
 125         struct dst_entry *dst;
 126
 127         afinfo = xfrm_policy_get_afinfo(family);
 128         if (unlikely(afinfo == NULL))
 129                 return ERR_PTR(-EAFNOSUPPORT);
 130
 131         dst = afinfo->dst_lookup(net, tos, oif, saddr, daddr);
 132
 133         rcu_read_unlock();
 134
 135         return dst;
 136 }
 137 EXPORT_SYMBOL(__xfrm_dst_lookup);
 138
 139 static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x,
 140                                                 int tos, int oif,
 141                                                 xfrm_address_t *prev_saddr,
 142                                                 xfrm_address_t *prev_daddr,
 143                                                 int family)
 144 {
 145         struct net *net = xs_net(x);
 146         xfrm_address_t *saddr = &x->props.saddr;
 147         xfrm_address_t *daddr = &x->id.daddr;
 148         struct dst_entry *dst;
 149
 150         if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) {
 151                 saddr = x->coaddr;
 152                 daddr = prev_daddr;
 153         }
 154         if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) {
 155                 saddr = prev_saddr;
 156                 daddr = x->coaddr;
 157         }
 158
 159         dst = __xfrm_dst_lookup(net, tos, oif, saddr, daddr, family);
 160
 161         if (!IS_ERR(dst)) {
 162                 if (prev_saddr != saddr)
 163                         memcpy(prev_saddr, saddr,  sizeof(*prev_saddr));
 164                 if (prev_daddr != daddr)
 165                         memcpy(prev_daddr, daddr,  sizeof(*prev_daddr));
 166         }
 167
 168         return dst;
 169 }
 170
 171 static inline unsigned long make_jiffies(long secs)
 172 {
 173         if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
 174                 return MAX_SCHEDULE_TIMEOUT-1;
 175         else
 176                 return secs*HZ;
 177 }
 178
 179 static void xfrm_policy_timer(unsigned long data)
 180 {
 181         struct xfrm_policy *xp = (struct xfrm_policy *)data;
 182         unsigned long now = get_seconds();
 183         long next = LONG_MAX;
 184         int warn = 0;
 185         int dir;
 186
 187         read_lock(&xp->lock);
 188
 189         if (unlikely(xp->walk.dead))
 190                 goto out;
 191
 192         dir = xfrm_policy_id2dir(xp->index);
 193
 194         if (xp->lft.hard_add_expires_seconds) {
 195                 long tmo = xp->lft.hard_add_expires_seconds +
 196                         xp->curlft.add_time - now;
 197                 if (tmo <= 0)
 198                         goto expired;
 199                 if (tmo < next)
 200                         next = tmo;
 201         }
 202         if (xp->lft.hard_use_expires_seconds) {
 203                 long tmo = xp->lft.hard_use_expires_seconds +
 204                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 205                 if (tmo <= 0)
 206                         goto expired;
 207                 if (tmo < next)
 208                         next = tmo;
 209         }
 210         if (xp->lft.soft_add_expires_seconds) {
 211                 long tmo = xp->lft.soft_add_expires_seconds +
 212                         xp->curlft.add_time - now;
 213                 if (tmo <= 0) {
 214                         warn = 1;
 215                         tmo = XFRM_KM_TIMEOUT;
 216                 }
 217                 if (tmo < next)
 218                         next = tmo;
 219         }
 220         if (xp->lft.soft_use_expires_seconds) {
 221                 long tmo = xp->lft.soft_use_expires_seconds +
 222                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 223                 if (tmo <= 0) {
 224                         warn = 1;
 225                         tmo = XFRM_KM_TIMEOUT;
 226                 }
 227                 if (tmo < next)
 228                         next = tmo;
 229         }
 230
 231         if (warn)
 232                 km_policy_expired(xp, dir, 0, 0);
 233         if (next != LONG_MAX &&
 234             !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
 235                 xfrm_pol_hold(xp);
 236
 237 out:
 238         read_unlock(&xp->lock);
 239         xfrm_pol_put(xp);
 240         return;
 241
 242 expired:
 243         read_unlock(&xp->lock);
 244         if (!xfrm_policy_delete(xp, dir))
 245                 km_policy_expired(xp, dir, 1, 0);
 246         xfrm_pol_put(xp);
 247 }
 248
 249 static struct flow_cache_object *xfrm_policy_flo_get(struct flow_cache_object *flo)
 250 {
 251         struct xfrm_policy *pol = container_of(flo, struct xfrm_policy, flo);
 252
 253         if (unlikely(pol->walk.dead))
 254                 flo = NULL;
 255         else
 256                 xfrm_pol_hold(pol);
 257
 258         return flo;
 259 }
 260
 261 static int xfrm_policy_flo_check(struct flow_cache_object *flo)
 262 {
 263         struct xfrm_policy *pol = container_of(flo, struct xfrm_policy, flo);
 264
 265         return !pol->walk.dead;
 266 }
 267
 268 static void xfrm_policy_flo_delete(struct flow_cache_object *flo)
 269 {
 270         xfrm_pol_put(container_of(flo, struct xfrm_policy, flo));
 271 }
 272
 273 static const struct flow_cache_ops xfrm_policy_fc_ops = {
 274         .get = xfrm_policy_flo_get,
 275         .check = xfrm_policy_flo_check,
 276         .delete = xfrm_policy_flo_delete,
 277 };
 278
 279 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
 280  * SPD calls.
 281  */
 282
 283 struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
 284 {
 285         struct xfrm_policy *policy;
 286
 287         policy = kzalloc(sizeof(struct xfrm_policy), gfp);
 288
 289         if (policy) {
 290                 write_pnet(&policy->xp_net, net);
 291                 INIT_LIST_HEAD(&policy->walk.all);
 292                 INIT_HLIST_NODE(&policy->bydst);
 293                 INIT_HLIST_NODE(&policy->byidx);
 294                 rwlock_init(&policy->lock);
 295                 refcount_set(&policy->refcnt, 1);
 296                 skb_queue_head_init(&policy->polq.hold_queue);
 297                 setup_timer(&policy->timer, xfrm_policy_timer,
 298                                 (unsigned long)policy);
 299                 setup_timer(&policy->polq.hold_timer, xfrm_policy_queue_process,
 300                             (unsigned long)policy);
 301                 policy->flo.ops = &xfrm_policy_fc_ops;
 302         }
 303         return policy;
 304 }
 305 EXPORT_SYMBOL(xfrm_policy_alloc);
 306
 307 static void xfrm_policy_destroy_rcu(struct rcu_head *head)
 308 {
 309         struct xfrm_policy *policy = container_of(head, struct xfrm_policy, rcu);
 310
 311         security_xfrm_policy_free(policy->security);
 312         kfree(policy);
 313 }
 314
 315 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
 316
 317 void xfrm_policy_destroy(struct xfrm_policy *policy)
 318 {
 319         BUG_ON(!policy->walk.dead);
 320
 321         if (del_timer(&policy->timer) || del_timer(&policy->polq.hold_timer))
 322                 BUG();
 323
 324         call_rcu(&policy->rcu, xfrm_policy_destroy_rcu);
 325 }
 326 EXPORT_SYMBOL(xfrm_policy_destroy);
 327
 328 /* Rule must be locked. Release descendant resources, announce
 329  * entry dead. The rule must be unlinked from lists to the moment.
 330  */
 331
 332 static void xfrm_policy_kill(struct xfrm_policy *policy)
 333 {
 334         policy->walk.dead = 1;
 335
 336         atomic_inc(&policy->genid);
 337
 338         if (del_timer(&policy->polq.hold_timer))
 339                 xfrm_pol_put(policy);
 340         skb_queue_purge(&policy->polq.hold_queue);
 341
 342         if (del_timer(&policy->timer))
 343                 xfrm_pol_put(policy);
 344
 345         xfrm_pol_put(policy);
 346 }
 347
 348 static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
 349
 350 static inline unsigned int idx_hash(struct net *net, u32 index)
 351 {
 352         return __idx_hash(index, net->xfrm.policy_idx_hmask);
 353 }
 354
 355 /* calculate policy hash thresholds */
 356 static void __get_hash_thresh(struct net *net,
 357                               unsigned short family, int dir,
 358                               u8 *dbits, u8 *sbits)
 359 {
 360         switch (family) {
 361         case AF_INET:
 362                 *dbits = net->xfrm.policy_bydst[dir].dbits4;
 363                 *sbits = net->xfrm.policy_bydst[dir].sbits4;
 364                 break;
 365
 366         case AF_INET6:
 367                 *dbits = net->xfrm.policy_bydst[dir].dbits6;
 368                 *sbits = net->xfrm.policy_bydst[dir].sbits6;
 369                 break;
 370
 371         default:
 372                 *dbits = 0;
 373                 *sbits = 0;
 374         }
 375 }
 376
 377 static struct hlist_head *policy_hash_bysel(struct net *net,
 378                                             const struct xfrm_selector *sel,
 379                                             unsigned short family, int dir)
 380 {
 381         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 382         unsigned int hash;
 383         u8 dbits;
 384         u8 sbits;
 385
 386         __get_hash_thresh(net, family, dir, &dbits, &sbits);
 387         hash = __sel_hash(sel, family, hmask, dbits, sbits);
 388
 389         if (hash == hmask + 1)
 390                 return &net->xfrm.policy_inexact[dir];
 391
 392         return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
 393                      lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
 394 }
 395
 396 static struct hlist_head *policy_hash_direct(struct net *net,
 397                                              const xfrm_address_t *daddr,
 398                                              const xfrm_address_t *saddr,
 399                                              unsigned short family, int dir)
 400 {
 401         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 402         unsigned int hash;
 403         u8 dbits;
 404         u8 sbits;
 405
 406         __get_hash_thresh(net, family, dir, &dbits, &sbits);
 407         hash = __addr_hash(daddr, saddr, family, hmask, dbits, sbits);
 408
 409         return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
 410                      lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
 411 }
 412
 413 static void xfrm_dst_hash_transfer(struct net *net,
 414                                    struct hlist_head *list,
 415                                    struct hlist_head *ndsttable,
 416                                    unsigned int nhashmask,
 417                                    int dir)
 418 {
 419         struct hlist_node *tmp, *entry0 = NULL;
 420         struct xfrm_policy *pol;
 421         unsigned int h0 = 0;
 422         u8 dbits;
 423         u8 sbits;
 424
 425 redo:
 426         hlist_for_each_entry_safe(pol, tmp, list, bydst) {
 427                 unsigned int h;
 428
 429                 __get_hash_thresh(net, pol->family, dir, &dbits, &sbits);
 430                 h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
 431                                 pol->family, nhashmask, dbits, sbits);
 432                 if (!entry0) {
 433                         hlist_del_rcu(&pol->bydst);
 434                         hlist_add_head_rcu(&pol->bydst, ndsttable + h);
 435                         h0 = h;
 436                 } else {
 437                         if (h != h0)
 438                                 continue;
 439                         hlist_del_rcu(&pol->bydst);
 440                         hlist_add_behind_rcu(&pol->bydst, entry0);
 441                 }
 442                 entry0 = &pol->bydst;
 443         }
 444         if (!hlist_empty(list)) {
 445                 entry0 = NULL;
 446                 goto redo;
 447         }
 448 }
 449
 450 static void xfrm_idx_hash_transfer(struct hlist_head *list,
 451                                    struct hlist_head *nidxtable,
 452                                    unsigned int nhashmask)
 453 {
 454         struct hlist_node *tmp;
 455         struct xfrm_policy *pol;
 456
 457         hlist_for_each_entry_safe(pol, tmp, list, byidx) {
 458                 unsigned int h;
 459
 460                 h = __idx_hash(pol->index, nhashmask);
 461                 hlist_add_head(&pol->byidx, nidxtable+h);
 462         }
 463 }
 464
 465 static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
 466 {
 467         return ((old_hmask + 1) << 1) - 1;
 468 }
 469
 470 static void xfrm_bydst_resize(struct net *net, int dir)
 471 {
 472         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 473         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 474         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 475         struct hlist_head *ndst = xfrm_hash_alloc(nsize);
 476         struct hlist_head *odst;
 477         int i;
 478
 479         if (!ndst)
 480                 return;
 481
 482         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 483         write_seqcount_begin(&xfrm_policy_hash_generation);
 484
 485         odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
 486                                 lockdep_is_held(&net->xfrm.xfrm_policy_lock));
 487
 488         odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
 489                                 lockdep_is_held(&net->xfrm.xfrm_policy_lock));
 490
 491         for (i = hmask; i >= 0; i--)
 492                 xfrm_dst_hash_transfer(net, odst + i, ndst, nhashmask, dir);
 493
 494         rcu_assign_pointer(net->xfrm.policy_bydst[dir].table, ndst);
 495         net->xfrm.policy_bydst[dir].hmask = nhashmask;
 496
 497         write_seqcount_end(&xfrm_policy_hash_generation);
 498         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 499
 500         synchronize_rcu();
 501
 502         xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
 503 }
 504
 505 static void xfrm_byidx_resize(struct net *net, int total)
 506 {
 507         unsigned int hmask = net->xfrm.policy_idx_hmask;
 508         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 509         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 510         struct hlist_head *oidx = net->xfrm.policy_byidx;
 511         struct hlist_head *nidx = xfrm_hash_alloc(nsize);
 512         int i;
 513
 514         if (!nidx)
 515                 return;
 516
 517         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 518
 519         for (i = hmask; i >= 0; i--)
 520                 xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
 521
 522         net->xfrm.policy_byidx = nidx;
 523         net->xfrm.policy_idx_hmask = nhashmask;
 524
 525         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 526
 527         xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
 528 }
 529
 530 static inline int xfrm_bydst_should_resize(struct net *net, int dir, int *total)
 531 {
 532         unsigned int cnt = net->xfrm.policy_count[dir];
 533         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 534
 535         if (total)
 536                 *total += cnt;
 537
 538         if ((hmask + 1) < xfrm_policy_hashmax &&
 539             cnt > hmask)
 540                 return 1;
 541
 542         return 0;
 543 }
 544
 545 static inline int xfrm_byidx_should_resize(struct net *net, int total)
 546 {
 547         unsigned int hmask = net->xfrm.policy_idx_hmask;
 548
 549         if ((hmask + 1) < xfrm_policy_hashmax &&
 550             total > hmask)
 551                 return 1;
 552
 553         return 0;
 554 }
 555
 556 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
 557 {
 558         si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
 559         si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
 560         si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
 561         si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
 562         si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
 563         si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
 564         si->spdhcnt = net->xfrm.policy_idx_hmask;
 565         si->spdhmcnt = xfrm_policy_hashmax;
 566 }
 567 EXPORT_SYMBOL(xfrm_spd_getinfo);
 568
 569 static DEFINE_MUTEX(hash_resize_mutex);
 570 static void xfrm_hash_resize(struct work_struct *work)
 571 {
 572         struct net *net = container_of(work, struct net, xfrm.policy_hash_work);
 573         int dir, total;
 574
 575         mutex_lock(&hash_resize_mutex);
 576
 577         total = 0;
 578         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 579                 if (xfrm_bydst_should_resize(net, dir, &total))
 580                         xfrm_bydst_resize(net, dir);
 581         }
 582         if (xfrm_byidx_should_resize(net, total))
 583                 xfrm_byidx_resize(net, total);
 584
 585         mutex_unlock(&hash_resize_mutex);
 586 }
 587
 588 static void xfrm_hash_rebuild(struct work_struct *work)
 589 {
 590         struct net *net = container_of(work, struct net,
 591                                        xfrm.policy_hthresh.work);
 592         unsigned int hmask;
 593         struct xfrm_policy *pol;
 594         struct xfrm_policy *policy;
 595         struct hlist_head *chain;
 596         struct hlist_head *odst;
 597         struct hlist_node *newpos;
 598         int i;
 599         int dir;
 600         unsigned seq;
 601         u8 lbits4, rbits4, lbits6, rbits6;
 602
 603         mutex_lock(&hash_resize_mutex);
 604
 605         /* read selector prefixlen thresholds */
 606         do {
 607                 seq = read_seqbegin(&net->xfrm.policy_hthresh.lock);
 608
 609                 lbits4 = net->xfrm.policy_hthresh.lbits4;
 610                 rbits4 = net->xfrm.policy_hthresh.rbits4;
 611                 lbits6 = net->xfrm.policy_hthresh.lbits6;
 612                 rbits6 = net->xfrm.policy_hthresh.rbits6;
 613         } while (read_seqretry(&net->xfrm.policy_hthresh.lock, seq));
 614
 615         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 616
 617         /* reset the bydst and inexact table in all directions */
 618         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 619                 INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
 620                 hmask = net->xfrm.policy_bydst[dir].hmask;
 621                 odst = net->xfrm.policy_bydst[dir].table;
 622                 for (i = hmask; i >= 0; i--)
 623                         INIT_HLIST_HEAD(odst + i);
 624                 if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
 625                         /* dir out => dst = remote, src = local */
 626                         net->xfrm.policy_bydst[dir].dbits4 = rbits4;
 627                         net->xfrm.policy_bydst[dir].sbits4 = lbits4;
 628                         net->xfrm.policy_bydst[dir].dbits6 = rbits6;
 629                         net->xfrm.policy_bydst[dir].sbits6 = lbits6;
 630                 } else {
 631                         /* dir in/fwd => dst = local, src = remote */
 632                         net->xfrm.policy_bydst[dir].dbits4 = lbits4;
 633                         net->xfrm.policy_bydst[dir].sbits4 = rbits4;
 634                         net->xfrm.policy_bydst[dir].dbits6 = lbits6;
 635                         net->xfrm.policy_bydst[dir].sbits6 = rbits6;
 636                 }
 637         }
 638
 639         /* re-insert all policies by order of creation */
 640         list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
 641                 if (xfrm_policy_id2dir(policy->index) >= XFRM_POLICY_MAX) {
 642                         /* skip socket policies */
 643                         continue;
 644                 }
 645                 newpos = NULL;
 646                 chain = policy_hash_bysel(net, &policy->selector,
 647                                           policy->family,
 648                                           xfrm_policy_id2dir(policy->index));
 649                 hlist_for_each_entry(pol, chain, bydst) {
 650                         if (policy->priority >= pol->priority)
 651                                 newpos = &pol->bydst;
 652                         else
 653                                 break;
 654                 }
 655                 if (newpos)
 656                         hlist_add_behind(&policy->bydst, newpos);
 657                 else
 658                         hlist_add_head(&policy->bydst, chain);
 659         }
 660
 661         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 662
 663         mutex_unlock(&hash_resize_mutex);
 664 }
 665
 666 void xfrm_policy_hash_rebuild(struct net *net)
 667 {
 668         schedule_work(&net->xfrm.policy_hthresh.work);
 669 }
 670 EXPORT_SYMBOL(xfrm_policy_hash_rebuild);
 671
 672 /* Generate new index... KAME seems to generate them ordered by cost
 673  * of an absolute inpredictability of ordering of rules. This will not pass. */
 674 static u32 xfrm_gen_index(struct net *net, int dir, u32 index)
 675 {
 676         static u32 idx_generator;
 677
 678         for (;;) {
 679                 struct hlist_head *list;
 680                 struct xfrm_policy *p;
 681                 u32 idx;
 682                 int found;
 683
 684                 if (!index) {
 685                         idx = (idx_generator | dir);
 686                         idx_generator += 8;
 687                 } else {
 688                         idx = index;
 689                         index = 0;
 690                 }
 691
 692                 if (idx == 0)
 693                         idx = 8;
 694                 list = net->xfrm.policy_byidx + idx_hash(net, idx);
 695                 found = 0;
 696                 hlist_for_each_entry(p, list, byidx) {
 697                         if (p->index == idx) {
 698                                 found = 1;
 699                                 break;
 700                         }
 701                 }
 702                 if (!found)
 703                         return idx;
 704         }
 705 }
 706
 707 static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
 708 {
 709         u32 *p1 = (u32 *) s1;
 710         u32 *p2 = (u32 *) s2;
 711         int len = sizeof(struct xfrm_selector) / sizeof(u32);
 712         int i;
 713
 714         for (i = 0; i < len; i++) {
 715                 if (p1[i] != p2[i])
 716                         return 1;
 717         }
 718
 719         return 0;
 720 }
 721
 722 static void xfrm_policy_requeue(struct xfrm_policy *old,
 723                                 struct xfrm_policy *new)
 724 {
 725         struct xfrm_policy_queue *pq = &old->polq;
 726         struct sk_buff_head list;
 727
 728         if (skb_queue_empty(&pq->hold_queue))
 729                 return;
 730
 731         __skb_queue_head_init(&list);
 732
 733         spin_lock_bh(&pq->hold_queue.lock);
 734         skb_queue_splice_init(&pq->hold_queue, &list);
 735         if (del_timer(&pq->hold_timer))
 736                 xfrm_pol_put(old);
 737         spin_unlock_bh(&pq->hold_queue.lock);
 738
 739         pq = &new->polq;
 740
 741         spin_lock_bh(&pq->hold_queue.lock);
 742         skb_queue_splice(&list, &pq->hold_queue);
 743         pq->timeout = XFRM_QUEUE_TMO_MIN;
 744         if (!mod_timer(&pq->hold_timer, jiffies))
 745                 xfrm_pol_hold(new);
 746         spin_unlock_bh(&pq->hold_queue.lock);
 747 }
 748
 749 static bool xfrm_policy_mark_match(struct xfrm_policy *policy,
 750                                    struct xfrm_policy *pol)
 751 {
 752         u32 mark = policy->mark.v & policy->mark.m;
 753
 754         if (policy->mark.v == pol->mark.v && policy->mark.m == pol->mark.m)
 755                 return true;
 756
 757         if ((mark & pol->mark.m) == pol->mark.v &&
 758             policy->priority == pol->priority)
 759                 return true;
 760
 761         return false;
 762 }
 763
 764 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 765 {
 766         struct net *net = xp_net(policy);
 767         struct xfrm_policy *pol;
 768         struct xfrm_policy *delpol;
 769         struct hlist_head *chain;
 770         struct hlist_node *newpos;
 771
 772         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 773         chain = policy_hash_bysel(net, &policy->selector, policy->family, dir);
 774         delpol = NULL;
 775         newpos = NULL;
 776         hlist_for_each_entry(pol, chain, bydst) {
 777                 if (pol->type == policy->type &&
 778                     !selector_cmp(&pol->selector, &policy->selector) &&
 779                     xfrm_policy_mark_match(policy, pol) &&
 780                     xfrm_sec_ctx_match(pol->security, policy->security) &&
 781                     !WARN_ON(delpol)) {
 782                         if (excl) {
 783                                 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 784                                 return -EEXIST;
 785                         }
 786                         delpol = pol;
 787                         if (policy->priority > pol->priority)
 788                                 continue;
 789                 } else if (policy->priority >= pol->priority) {
 790                         newpos = &pol->bydst;
 791                         continue;
 792                 }
 793                 if (delpol)
 794                         break;
 795         }
 796         if (newpos)
 797                 hlist_add_behind(&policy->bydst, newpos);
 798         else
 799                 hlist_add_head(&policy->bydst, chain);
 800         __xfrm_policy_link(policy, dir);
 801         atomic_inc(&net->xfrm.flow_cache_genid);
 802
 803         /* After previous checking, family can either be AF_INET or AF_INET6 */
 804         if (policy->family == AF_INET)
 805                 rt_genid_bump_ipv4(net);
 806         else
 807                 rt_genid_bump_ipv6(net);
 808
 809         if (delpol) {
 810                 xfrm_policy_requeue(delpol, policy);
 811                 __xfrm_policy_unlink(delpol, dir);
 812         }
 813         policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir, policy->index);
 814         hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
 815         policy->curlft.add_time = get_seconds();
 816         policy->curlft.use_time = 0;
 817         if (!mod_timer(&policy->timer, jiffies + HZ))
 818                 xfrm_pol_hold(policy);
 819         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 820
 821         if (delpol)
 822                 xfrm_policy_kill(delpol);
 823         else if (xfrm_bydst_should_resize(net, dir, NULL))
 824                 schedule_work(&net->xfrm.policy_hash_work);
 825
 826         return 0;
 827 }
 828 EXPORT_SYMBOL(xfrm_policy_insert);
 829
 830 struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u8 type,
 831                                           int dir, struct xfrm_selector *sel,
 832                                           struct xfrm_sec_ctx *ctx, int delete,
 833                                           int *err)
 834 {
 835         struct xfrm_policy *pol, *ret;
 836         struct hlist_head *chain;
 837
 838         *err = 0;
 839         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 840         chain = policy_hash_bysel(net, sel, sel->family, dir);
 841         ret = NULL;
 842         hlist_for_each_entry(pol, chain, bydst) {
 843                 if (pol->type == type &&
 844                     (mark & pol->mark.m) == pol->mark.v &&
 845                     !selector_cmp(sel, &pol->selector) &&
 846                     xfrm_sec_ctx_match(ctx, pol->security)) {
 847                         xfrm_pol_hold(pol);
 848                         if (delete) {
 849                                 *err = security_xfrm_policy_delete(
 850                                                                 pol->security);
 851                                 if (*err) {
 852                                         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 853                                         return pol;
 854                                 }
 855                                 __xfrm_policy_unlink(pol, dir);
 856                         }
 857                         ret = pol;
 858                         break;
 859                 }
 860         }
 861         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 862
 863         if (ret && delete)
 864                 xfrm_policy_kill(ret);
 865         return ret;
 866 }
 867 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
 868
 869 struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8 type,
 870                                      int dir, u32 id, int delete, int *err)
 871 {
 872         struct xfrm_policy *pol, *ret;
 873         struct hlist_head *chain;
 874
 875         *err = -ENOENT;
 876         if (xfrm_policy_id2dir(id) != dir)
 877                 return NULL;
 878
 879         *err = 0;
 880         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 881         chain = net->xfrm.policy_byidx + idx_hash(net, id);
 882         ret = NULL;
 883         hlist_for_each_entry(pol, chain, byidx) {
 884                 if (pol->type == type && pol->index == id &&
 885                     (mark & pol->mark.m) == pol->mark.v) {
 886                         xfrm_pol_hold(pol);
 887                         if (delete) {
 888                                 *err = security_xfrm_policy_delete(
 889                                                                 pol->security);
 890                                 if (*err) {
 891                                         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 892                                         return pol;
 893                                 }
 894                                 __xfrm_policy_unlink(pol, dir);
 895                         }
 896                         ret = pol;
 897                         break;
 898                 }
 899         }
 900         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 901
 902         if (ret && delete)
 903                 xfrm_policy_kill(ret);
 904         return ret;
 905 }
 906 EXPORT_SYMBOL(xfrm_policy_byid);
 907
 908 #ifdef CONFIG_SECURITY_NETWORK_XFRM
 909 static inline int
 910 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
 911 {
 912         int dir, err = 0;
 913
 914         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 915                 struct xfrm_policy *pol;
 916                 int i;
 917
 918                 hlist_for_each_entry(pol,
 919                                      &net->xfrm.policy_inexact[dir], bydst) {
 920                         if (pol->type != type)
 921                                 continue;
 922                         err = security_xfrm_policy_delete(pol->security);
 923                         if (err) {
 924                                 xfrm_audit_policy_delete(pol, 0, task_valid);
 925                                 return err;
 926                         }
 927                 }
 928                 for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
 929                         hlist_for_each_entry(pol,
 930                                              net->xfrm.policy_bydst[dir].table + i,
 931                                              bydst) {
 932                                 if (pol->type != type)
 933                                         continue;
 934                                 err = security_xfrm_policy_delete(
 935                                                                 pol->security);
 936                                 if (err) {
 937                                         xfrm_audit_policy_delete(pol, 0,
 938                                                                  task_valid);
 939                                         return err;
 940                                 }
 941                         }
 942                 }
 943         }
 944         return err;
 945 }
 946 #else
 947 static inline int
 948 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
 949 {
 950         return 0;
 951 }
 952 #endif
 953
 954 int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
 955 {
 956         int dir, err = 0, cnt = 0;
 957
 958         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 959
 960         err = xfrm_policy_flush_secctx_check(net, type, task_valid);
 961         if (err)
 962                 goto out;
 963
 964         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 965                 struct xfrm_policy *pol;
 966                 int i;
 967
 968         again1:
 969                 hlist_for_each_entry(pol,
 970                                      &net->xfrm.policy_inexact[dir], bydst) {
 971                         if (pol->type != type)
 972                                 continue;
 973                         __xfrm_policy_unlink(pol, dir);
 974                         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 975                         cnt++;
 976
 977                         xfrm_audit_policy_delete(pol, 1, task_valid);
 978
 979                         xfrm_policy_kill(pol);
 980
 981                         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 982                         goto again1;
 983                 }
 984
 985                 for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
 986         again2:
 987                         hlist_for_each_entry(pol,
 988                                              net->xfrm.policy_bydst[dir].table + i,
 989                                              bydst) {
 990                                 if (pol->type != type)
 991                                         continue;
 992                                 __xfrm_policy_unlink(pol, dir);
 993                                 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 994                                 cnt++;
 995
 996                                 xfrm_audit_policy_delete(pol, 1, task_valid);
 997                                 xfrm_policy_kill(pol);
 998
 999                                 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1000                                 goto again2;
1001                         }
1002                 }
1003
1004         }
1005         if (!cnt)
1006                 err = -ESRCH;
1007 out:
1008         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1009         return err;
1010 }
1011 EXPORT_SYMBOL(xfrm_policy_flush);
1012
1013 int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
1014                      int (*func)(struct xfrm_policy *, int, int, void*),
1015                      void *data)
1016 {
1017         struct xfrm_policy *pol;
1018         struct xfrm_policy_walk_entry *x;
1019         int error = 0;
1020
1021         if (walk->type >= XFRM_POLICY_TYPE_MAX &&
1022             walk->type != XFRM_POLICY_TYPE_ANY)
1023                 return -EINVAL;
1024
1025         if (list_empty(&walk->walk.all) && walk->seq != 0)
1026                 return 0;
1027
1028         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1029         if (list_empty(&walk->walk.all))
1030                 x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
1031         else
1032                 x = list_first_entry(&walk->walk.all,
1033                                      struct xfrm_policy_walk_entry, all);
1034
1035         list_for_each_entry_from(x, &net->xfrm.policy_all, all) {
1036                 if (x->dead)
1037                         continue;
1038                 pol = container_of(x, struct xfrm_policy, walk);
1039                 if (walk->type != XFRM_POLICY_TYPE_ANY &&
1040                     walk->type != pol->type)
1041                         continue;
1042                 error = func(pol, xfrm_policy_id2dir(pol->index),
1043                              walk->seq, data);
1044                 if (error) {
1045                         list_move_tail(&walk->walk.all, &x->all);
1046                         goto out;
1047                 }
1048                 walk->seq++;
1049         }
1050         if (walk->seq == 0) {
1051                 error = -ENOENT;
1052                 goto out;
1053         }
1054         list_del_init(&walk->walk.all);
1055 out:
1056         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1057         return error;
1058 }
1059 EXPORT_SYMBOL(xfrm_policy_walk);
1060
1061 void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type)
1062 {
1063         INIT_LIST_HEAD(&walk->walk.all);
1064         walk->walk.dead = 1;
1065         walk->type = type;
1066         walk->seq = 0;
1067 }
1068 EXPORT_SYMBOL(xfrm_policy_walk_init);
1069
1070 void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net)
1071 {
1072         if (list_empty(&walk->walk.all))
1073                 return;
1074
1075         spin_lock_bh(&net->xfrm.xfrm_policy_lock); /*FIXME where is net? */
1076         list_del(&walk->walk.all);
1077         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1078 }
1079 EXPORT_SYMBOL(xfrm_policy_walk_done);
1080
1081 /*
1082  * Find policy to apply to this flow.
1083  *
1084  * Returns 0 if policy found, else an -errno.
1085  */
1086 static int xfrm_policy_match(const struct xfrm_policy *pol,
1087                              const struct flowi *fl,
1088                              u8 type, u16 family, int dir)
1089 {
1090         const struct xfrm_selector *sel = &pol->selector;
1091         int ret = -ESRCH;
1092         bool match;
1093
1094         if (pol->family != family ||
1095             (fl->flowi_mark & pol->mark.m) != pol->mark.v ||
1096             pol->type != type)
1097                 return ret;
1098
1099         match = xfrm_selector_match(sel, fl, family);
1100         if (match)
1101                 ret = security_xfrm_policy_lookup(pol->security, fl->flowi_secid,
1102                                                   dir);
1103
1104         return ret;
1105 }
1106
1107 static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
1108                                                      const struct flowi *fl,
1109                                                      u16 family, u8 dir)
1110 {
1111         int err;
1112         struct xfrm_policy *pol, *ret;
1113         const xfrm_address_t *daddr, *saddr;
1114         struct hlist_head *chain;
1115         unsigned int sequence;
1116         u32 priority;
1117
1118         daddr = xfrm_flowi_daddr(fl, family);
1119         saddr = xfrm_flowi_saddr(fl, family);
1120         if (unlikely(!daddr || !saddr))
1121                 return NULL;
1122
1123         rcu_read_lock();
1124  retry:
1125         do {
1126                 sequence = read_seqcount_begin(&xfrm_policy_hash_generation);
1127                 chain = policy_hash_direct(net, daddr, saddr, family, dir);
1128         } while (read_seqcount_retry(&xfrm_policy_hash_generation, sequence));
1129
1130         priority = ~0U;
1131         ret = NULL;
1132         hlist_for_each_entry_rcu(pol, chain, bydst) {
1133                 err = xfrm_policy_match(pol, fl, type, family, dir);
1134                 if (err) {
1135                         if (err == -ESRCH)
1136                                 continue;
1137                         else {
1138                                 ret = ERR_PTR(err);
1139                                 goto fail;
1140                         }
1141                 } else {
1142                         ret = pol;
1143                         priority = ret->priority;
1144                         break;
1145                 }
1146         }
1147         chain = &net->xfrm.policy_inexact[dir];
1148         hlist_for_each_entry_rcu(pol, chain, bydst) {
1149                 if ((pol->priority >= priority) && ret)
1150                         break;
1151
1152                 err = xfrm_policy_match(pol, fl, type, family, dir);
1153                 if (err) {
1154                         if (err == -ESRCH)
1155                                 continue;
1156                         else {
1157                                 ret = ERR_PTR(err);
1158                                 goto fail;
1159                         }
1160                 } else {
1161                         ret = pol;
1162                         break;
1163                 }
1164         }
1165
1166         if (read_seqcount_retry(&xfrm_policy_hash_generation, sequence))
1167                 goto retry;
1168
1169         if (ret && !xfrm_pol_hold_rcu(ret))
1170                 goto retry;
1171 fail:
1172         rcu_read_unlock();
1173
1174         return ret;
1175 }
1176
1177 static struct xfrm_policy *
1178 __xfrm_policy_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir)
1179 {
1180 #ifdef CONFIG_XFRM_SUB_POLICY
1181         struct xfrm_policy *pol;
1182
1183         pol = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_SUB, fl, family, dir);
1184         if (pol != NULL)
1185                 return pol;
1186 #endif
1187         return xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, fl, family, dir);
1188 }
1189
1190 static int flow_to_policy_dir(int dir)
1191 {
1192         if (XFRM_POLICY_IN == FLOW_DIR_IN &&
1193             XFRM_POLICY_OUT == FLOW_DIR_OUT &&
1194             XFRM_POLICY_FWD == FLOW_DIR_FWD)
1195                 return dir;
1196
1197         switch (dir) {
1198         default:
1199         case FLOW_DIR_IN:
1200                 return XFRM_POLICY_IN;
1201         case FLOW_DIR_OUT:
1202                 return XFRM_POLICY_OUT;
1203         case FLOW_DIR_FWD:
1204                 return XFRM_POLICY_FWD;
1205         }
1206 }
1207
1208 static struct flow_cache_object *
1209 xfrm_policy_lookup(struct net *net, const struct flowi *fl, u16 family,
1210                    u8 dir, struct flow_cache_object *old_obj, void *ctx)
1211 {
1212         struct xfrm_policy *pol;
1213
1214         if (old_obj)
1215                 xfrm_pol_put(container_of(old_obj, struct xfrm_policy, flo));
1216
1217         pol = __xfrm_policy_lookup(net, fl, family, flow_to_policy_dir(dir));
1218         if (IS_ERR_OR_NULL(pol))
1219                 return ERR_CAST(pol);
1220
1221         /* Resolver returns two references:
1222          * one for cache and one for caller of flow_cache_lookup() */
1223         xfrm_pol_hold(pol);
1224
1225         return &pol->flo;
1226 }
1227
1228 static inline int policy_to_flow_dir(int dir)
1229 {
1230         if (XFRM_POLICY_IN == FLOW_DIR_IN &&
1231             XFRM_POLICY_OUT == FLOW_DIR_OUT &&
1232             XFRM_POLICY_FWD == FLOW_DIR_FWD)
1233                 return dir;
1234         switch (dir) {
1235         default:
1236         case XFRM_POLICY_IN:
1237                 return FLOW_DIR_IN;
1238         case XFRM_POLICY_OUT:
1239                 return FLOW_DIR_OUT;
1240         case XFRM_POLICY_FWD:
1241                 return FLOW_DIR_FWD;
1242         }
1243 }
1244
1245 static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir,
1246                                                  const struct flowi *fl, u16 family)
1247 {
1248         struct xfrm_policy *pol;
1249
1250         rcu_read_lock();
1251  again:
1252         pol = rcu_dereference(sk->sk_policy[dir]);
1253         if (pol != NULL) {
1254                 bool match = xfrm_selector_match(&pol->selector, fl, family);
1255                 int err = 0;
1256
1257                 if (match) {
1258                         if ((sk->sk_mark & pol->mark.m) != pol->mark.v) {
1259                                 pol = NULL;
1260                                 goto out;
1261                         }
1262                         err = security_xfrm_policy_lookup(pol->security,
1263                                                       fl->flowi_secid,
1264                                                       policy_to_flow_dir(dir));
1265                         if (!err) {
1266                                 if (!xfrm_pol_hold_rcu(pol))
1267                                         goto again;
1268                         } else if (err == -ESRCH) {
1269                                 pol = NULL;
1270                         } else {
1271                                 pol = ERR_PTR(err);
1272                         }
1273                 } else
1274                         pol = NULL;
1275         }
1276 out:
1277         rcu_read_unlock();
1278         return pol;
1279 }
1280
1281 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
1282 {
1283         struct net *net = xp_net(pol);
1284
1285         list_add(&pol->walk.all, &net->xfrm.policy_all);
1286         net->xfrm.policy_count[dir]++;
1287         xfrm_pol_hold(pol);
1288 }
1289
1290 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
1291                                                 int dir)
1292 {
1293         struct net *net = xp_net(pol);
1294
1295         if (list_empty(&pol->walk.all))
1296                 return NULL;
1297
1298         /* Socket policies are not hashed. */
1299         if (!hlist_unhashed(&pol->bydst)) {
1300                 hlist_del_rcu(&pol->bydst);
1301                 hlist_del(&pol->byidx);
1302         }
1303
1304         list_del_init(&pol->walk.all);
1305         net->xfrm.policy_count[dir]--;
1306
1307         return pol;
1308 }
1309
1310 static void xfrm_sk_policy_link(struct xfrm_policy *pol, int dir)
1311 {
1312         __xfrm_policy_link(pol, XFRM_POLICY_MAX + dir);
1313 }
1314
1315 static void xfrm_sk_policy_unlink(struct xfrm_policy *pol, int dir)
1316 {
1317         __xfrm_policy_unlink(pol, XFRM_POLICY_MAX + dir);
1318 }
1319
1320 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
1321 {
1322         struct net *net = xp_net(pol);
1323
1324         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1325         pol = __xfrm_policy_unlink(pol, dir);
1326         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1327         if (pol) {
1328                 xfrm_policy_kill(pol);
1329                 return 0;
1330         }
1331         return -ENOENT;
1332 }
1333 EXPORT_SYMBOL(xfrm_policy_delete);
1334
1335 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
1336 {
1337         struct net *net = xp_net(pol);
1338         struct xfrm_policy *old_pol;
1339
1340 #ifdef CONFIG_XFRM_SUB_POLICY
1341         if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
1342                 return -EINVAL;
1343 #endif
1344
1345         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1346         old_pol = rcu_dereference_protected(sk->sk_policy[dir],
1347                                 lockdep_is_held(&net->xfrm.xfrm_policy_lock));
1348         if (pol) {
1349                 pol->curlft.add_time = get_seconds();
1350                 pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir, 0);
1351                 xfrm_sk_policy_link(pol, dir);
1352         }
1353         rcu_assign_pointer(sk->sk_policy[dir], pol);
1354         if (old_pol) {
1355                 if (pol)
1356                         xfrm_policy_requeue(old_pol, pol);
1357
1358                 /* Unlinking succeeds always. This is the only function
1359                  * allowed to delete or replace socket policy.
1360                  */
1361                 xfrm_sk_policy_unlink(old_pol, dir);
1362         }
1363         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1364
1365         if (old_pol) {
1366                 xfrm_policy_kill(old_pol);
1367         }
1368         return 0;
1369 }
1370
1371 static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
1372 {
1373         struct xfrm_policy *newp = xfrm_policy_alloc(xp_net(old), GFP_ATOMIC);
1374         struct net *net = xp_net(old);
1375
1376         if (newp) {
1377                 newp->selector = old->selector;
1378                 if (security_xfrm_policy_clone(old->security,
1379                                                &newp->security)) {
1380                         kfree(newp);
1381                         return NULL;  /* ENOMEM */
1382                 }
1383                 newp->lft = old->lft;
1384                 newp->curlft = old->curlft;
1385                 newp->mark = old->mark;
1386                 newp->action = old->action;
1387                 newp->flags = old->flags;
1388                 newp->xfrm_nr = old->xfrm_nr;
1389                 newp->index = old->index;
1390                 newp->type = old->type;
1391                 memcpy(newp->xfrm_vec, old->xfrm_vec,
1392                        newp->xfrm_nr*sizeof(struct xfrm_tmpl));
1393                 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1394                 xfrm_sk_policy_link(newp, dir);
1395                 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1396                 xfrm_pol_put(newp);
1397         }
1398         return newp;
1399 }
1400
1401 int __xfrm_sk_clone_policy(struct sock *sk, const struct sock *osk)
1402 {
1403         const struct xfrm_policy *p;
1404         struct xfrm_policy *np;
1405         int i, ret = 0;
1406
1407         rcu_read_lock();
1408         for (i = 0; i < 2; i++) {
1409                 p = rcu_dereference(osk->sk_policy[i]);
1410                 if (p) {
1411                         np = clone_policy(p, i);
1412                         if (unlikely(!np)) {
1413                                 ret = -ENOMEM;
1414                                 break;
1415                         }
1416                         rcu_assign_pointer(sk->sk_policy[i], np);
1417                 }
1418         }
1419         rcu_read_unlock();
1420         return ret;
1421 }
1422
1423 static int
1424 xfrm_get_saddr(struct net *net, int oif, xfrm_address_t *local,
1425                xfrm_address_t *remote, unsigned short family)
1426 {
1427         int err;
1428         const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1429
1430         if (unlikely(afinfo == NULL))
1431                 return -EINVAL;
1432         err = afinfo->get_saddr(net, oif, local, remote);
1433         rcu_read_unlock();
1434         return err;
1435 }
1436
1437 /* Resolve list of templates for the flow, given policy. */
1438
1439 static int
1440 xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
1441                       struct xfrm_state **xfrm, unsigned short family)
1442 {
1443         struct net *net = xp_net(policy);
1444         int nx;
1445         int i, error;
1446         xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
1447         xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
1448         xfrm_address_t tmp;
1449
1450         for (nx = 0, i = 0; i < policy->xfrm_nr; i++) {
1451                 struct xfrm_state *x;
1452                 xfrm_address_t *remote = daddr;
1453                 xfrm_address_t *local  = saddr;
1454                 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
1455
1456                 if (tmpl->mode == XFRM_MODE_TUNNEL ||
1457                     tmpl->mode == XFRM_MODE_BEET) {
1458                         remote = &tmpl->id.daddr;
1459                         local = &tmpl->saddr;
1460                         if (xfrm_addr_any(local, tmpl->encap_family)) {
1461                                 error = xfrm_get_saddr(net, fl->flowi_oif,
1462                                                        &tmp, remote,
1463                                                        tmpl->encap_family);
1464                                 if (error)
1465                                         goto fail;
1466                                 local = &tmp;
1467                         }
1468                 }
1469
1470                 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
1471
1472                 if (x && x->km.state == XFRM_STATE_VALID) {
1473                         xfrm[nx++] = x;
1474                         daddr = remote;
1475                         saddr = local;
1476                         continue;
1477                 }
1478                 if (x) {
1479                         error = (x->km.state == XFRM_STATE_ERROR ?
1480                                  -EINVAL : -EAGAIN);
1481                         xfrm_state_put(x);
1482                 } else if (error == -ESRCH) {
1483                         error = -EAGAIN;
1484                 }
1485
1486                 if (!tmpl->optional)
1487                         goto fail;
1488         }
1489         return nx;
1490
1491 fail:
1492         for (nx--; nx >= 0; nx--)
1493                 xfrm_state_put(xfrm[nx]);
1494         return error;
1495 }
1496
1497 static int
1498 xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, const struct flowi *fl,
1499                   struct xfrm_state **xfrm, unsigned short family)
1500 {
1501         struct xfrm_state *tp[XFRM_MAX_DEPTH];
1502         struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
1503         int cnx = 0;
1504         int error;
1505         int ret;
1506         int i;
1507
1508         for (i = 0; i < npols; i++) {
1509                 if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
1510                         error = -ENOBUFS;
1511                         goto fail;
1512                 }
1513
1514                 ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
1515                 if (ret < 0) {
1516                         error = ret;
1517                         goto fail;
1518                 } else
1519                         cnx += ret;
1520         }
1521
1522         /* found states are sorted for outbound processing */
1523         if (npols > 1)
1524                 xfrm_state_sort(xfrm, tpp, cnx, family);
1525
1526         return cnx;
1527
1528  fail:
1529         for (cnx--; cnx >= 0; cnx--)
1530                 xfrm_state_put(tpp[cnx]);
1531         return error;
1532
1533 }
1534
1535 static int xfrm_get_tos(const struct flowi *fl, int family)
1536 {
1537         const struct xfrm_policy_afinfo *afinfo;
1538         int tos = 0;
1539
1540         afinfo = xfrm_policy_get_afinfo(family);
1541         tos = afinfo ? afinfo->get_tos(fl) : 0;
1542
1543         rcu_read_unlock();
1544
1545         return tos;
1546 }
1547
1548 static struct flow_cache_object *xfrm_bundle_flo_get(struct flow_cache_object *flo)
1549 {
1550         struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1551         struct dst_entry *dst = &xdst->u.dst;
1552
1553         if (xdst->route == NULL) {
1554                 /* Dummy bundle - if it has xfrms we were not
1555                  * able to build bundle as template resolution failed.
1556                  * It means we need to try again resolving. */
1557                 if (xdst->num_xfrms > 0)
1558                         return NULL;
1559         } else if (dst->flags & DST_XFRM_QUEUE) {
1560                 return NULL;
1561         } else {
1562                 /* Real bundle */
1563                 if (stale_bundle(dst))
1564                         return NULL;
1565         }
1566
1567         dst_hold(dst);
1568         return flo;
1569 }
1570
1571 static int xfrm_bundle_flo_check(struct flow_cache_object *flo)
1572 {
1573         struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1574         struct dst_entry *dst = &xdst->u.dst;
1575
1576         if (!xdst->route)
1577                 return 0;
1578         if (stale_bundle(dst))
1579                 return 0;
1580
1581         return 1;
1582 }
1583
1584 static void xfrm_bundle_flo_delete(struct flow_cache_object *flo)
1585 {
1586         struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1587         struct dst_entry *dst = &xdst->u.dst;
1588
1589         /* Mark DST_OBSOLETE_DEAD to fail the next xfrm_dst_check() */
1590         dst->obsolete = DST_OBSOLETE_DEAD;
1591         dst_release_immediate(dst);
1592 }
1593
1594 static const struct flow_cache_ops xfrm_bundle_fc_ops = {
1595         .get = xfrm_bundle_flo_get,
1596         .check = xfrm_bundle_flo_check,
1597         .delete = xfrm_bundle_flo_delete,
1598 };
1599
1600 static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
1601 {
1602         const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1603         struct dst_ops *dst_ops;
1604         struct xfrm_dst *xdst;
1605
1606         if (!afinfo)
1607                 return ERR_PTR(-EINVAL);
1608
1609         switch (family) {
1610         case AF_INET:
1611                 dst_ops = &net->xfrm.xfrm4_dst_ops;
1612                 break;
1613 #if IS_ENABLED(CONFIG_IPV6)
1614         case AF_INET6:
1615                 dst_ops = &net->xfrm.xfrm6_dst_ops;
1616                 break;
1617 #endif
1618         default:
1619                 BUG();
1620         }
1621         xdst = dst_alloc(dst_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
1622
1623         if (likely(xdst)) {
1624                 struct dst_entry *dst = &xdst->u.dst;
1625
1626                 memset(dst + 1, 0, sizeof(*xdst) - sizeof(*dst));
1627                 xdst->flo.ops = &xfrm_bundle_fc_ops;
1628         } else
1629                 xdst = ERR_PTR(-ENOBUFS);
1630
1631         rcu_read_unlock();
1632
1633         return xdst;
1634 }
1635
1636 static inline int xfrm_init_path(struct xfrm_dst *path, struct dst_entry *dst,
1637                                  int nfheader_len)
1638 {
1639         const struct xfrm_policy_afinfo *afinfo =
1640                 xfrm_policy_get_afinfo(dst->ops->family);
1641         int err;
1642
1643         if (!afinfo)
1644                 return -EINVAL;
1645
1646         err = afinfo->init_path(path, dst, nfheader_len);
1647
1648         rcu_read_unlock();
1649
1650         return err;
1651 }
1652
1653 static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
1654                                 const struct flowi *fl)
1655 {
1656         const struct xfrm_policy_afinfo *afinfo =
1657                 xfrm_policy_get_afinfo(xdst->u.dst.ops->family);
1658         int err;
1659
1660         if (!afinfo)
1661                 return -EINVAL;
1662
1663         err = afinfo->fill_dst(xdst, dev, fl);
1664
1665         rcu_read_unlock();
1666
1667         return err;
1668 }
1669
1670
1671 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
1672  * all the metrics... Shortly, bundle a bundle.
1673  */
1674
1675 static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
1676                                             struct xfrm_state **xfrm, int nx,
1677                                             const struct flowi *fl,
1678                                             struct dst_entry *dst)
1679 {
1680         struct net *net = xp_net(policy);
1681         unsigned long now = jiffies;
1682         struct net_device *dev;
1683         struct xfrm_mode *inner_mode;
1684         struct dst_entry *dst_prev = NULL;
1685         struct dst_entry *dst0 = NULL;
1686         int i = 0;
1687         int err;
1688         int header_len = 0;
1689         int nfheader_len = 0;
1690         int trailer_len = 0;
1691         int tos;
1692         int family = policy->selector.family;
1693         xfrm_address_t saddr, daddr;
1694
1695         xfrm_flowi_addr_get(fl, &saddr, &daddr, family);
1696
1697         tos = xfrm_get_tos(fl, family);
1698
1699         dst_hold(dst);
1700
1701         for (; i < nx; i++) {
1702                 struct xfrm_dst *xdst = xfrm_alloc_dst(net, family);
1703                 struct dst_entry *dst1 = &xdst->u.dst;
1704
1705                 err = PTR_ERR(xdst);
1706                 if (IS_ERR(xdst)) {
1707                         dst_release(dst);
1708                         goto put_states;
1709                 }
1710
1711                 if (xfrm[i]->sel.family == AF_UNSPEC) {
1712                         inner_mode = xfrm_ip2inner_mode(xfrm[i],
1713                                                         xfrm_af2proto(family));
1714                         if (!inner_mode) {
1715                                 err = -EAFNOSUPPORT;
1716                                 dst_release(dst);
1717                                 goto put_states;
1718                         }
1719                 } else
1720                         inner_mode = xfrm[i]->inner_mode;
1721
1722                 if (!dst_prev)
1723                         dst0 = dst1;
1724                 else
1725                         /* Ref count is taken during xfrm_alloc_dst()
1726                          * No need to do dst_clone() on dst1
1727                          */
1728                         dst_prev->child = dst1;
1729
1730                 xdst->route = dst;
1731                 dst_copy_metrics(dst1, dst);
1732
1733                 if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
1734                         family = xfrm[i]->props.family;
1735                         dst = xfrm_dst_lookup(xfrm[i], tos, fl->flowi_oif,
1736                                               &saddr, &daddr, family);
1737                         err = PTR_ERR(dst);
1738                         if (IS_ERR(dst))
1739                                 goto put_states;
1740                 } else
1741                         dst_hold(dst);
1742
1743                 dst1->xfrm = xfrm[i];
1744                 xdst->xfrm_genid = xfrm[i]->genid;
1745
1746                 dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
1747                 dst1->flags |= DST_HOST;
1748                 dst1->lastuse = now;
1749
1750                 dst1->input = dst_discard;
1751                 dst1->output = inner_mode->afinfo->output;
1752
1753                 dst1->next = dst_prev;
1754                 dst_prev = dst1;
1755
1756                 header_len += xfrm[i]->props.header_len;
1757                 if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
1758                         nfheader_len += xfrm[i]->props.header_len;
1759                 trailer_len += xfrm[i]->props.trailer_len;
1760         }
1761
1762         dst_prev->child = dst;
1763         dst0->path = dst;
1764
1765         err = -ENODEV;
1766         dev = dst->dev;
1767         if (!dev)
1768                 goto free_dst;
1769
1770         xfrm_init_path((struct xfrm_dst *)dst0, dst, nfheader_len);
1771         xfrm_init_pmtu(dst_prev);
1772
1773         for (dst_prev = dst0; dst_prev != dst; dst_prev = dst_prev->child) {
1774                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst_prev;
1775
1776                 err = xfrm_fill_dst(xdst, dev, fl);
1777                 if (err)
1778                         goto free_dst;
1779
1780                 dst_prev->header_len = header_len;
1781                 dst_prev->trailer_len = trailer_len;
1782                 header_len -= xdst->u.dst.xfrm->props.header_len;
1783                 trailer_len -= xdst->u.dst.xfrm->props.trailer_len;
1784         }
1785
1786 out:
1787         return dst0;
1788
1789 put_states:
1790         for (; i < nx; i++)
1791                 xfrm_state_put(xfrm[i]);
1792 free_dst:
1793         if (dst0)
1794                 dst_release_immediate(dst0);
1795         dst0 = ERR_PTR(err);
1796         goto out;
1797 }
1798
1799 static int xfrm_expand_policies(const struct flowi *fl, u16 family,
1800                                 struct xfrm_policy **pols,
1801                                 int *num_pols, int *num_xfrms)
1802 {
1803         int i;
1804
1805         if (*num_pols == 0 || !pols[0]) {
1806                 *num_pols = 0;
1807                 *num_xfrms = 0;
1808                 return 0;
1809         }
1810         if (IS_ERR(pols[0]))
1811                 return PTR_ERR(pols[0]);
1812
1813         *num_xfrms = pols[0]->xfrm_nr;
1814
1815 #ifdef CONFIG_XFRM_SUB_POLICY
1816         if (pols[0] && pols[0]->action == XFRM_POLICY_ALLOW &&
1817             pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1818                 pols[1] = xfrm_policy_lookup_bytype(xp_net(pols[0]),
1819                                                     XFRM_POLICY_TYPE_MAIN,
1820                                                     fl, family,
1821                                                     XFRM_POLICY_OUT);
1822                 if (pols[1]) {
1823                         if (IS_ERR(pols[1])) {
1824                                 xfrm_pols_put(pols, *num_pols);
1825                                 return PTR_ERR(pols[1]);
1826                         }
1827                         (*num_pols)++;
1828                         (*num_xfrms) += pols[1]->xfrm_nr;
1829                 }
1830         }
1831 #endif
1832         for (i = 0; i < *num_pols; i++) {
1833                 if (pols[i]->action != XFRM_POLICY_ALLOW) {
1834                         *num_xfrms = -1;
1835                         break;
1836                 }
1837         }
1838
1839         return 0;
1840
1841 }
1842
1843 static struct xfrm_dst *
1844 xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
1845                                const struct flowi *fl, u16 family,
1846                                struct dst_entry *dst_orig)
1847 {
1848         struct net *net = xp_net(pols[0]);
1849         struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
1850         struct dst_entry *dst;
1851         struct xfrm_dst *xdst;
1852         int err;
1853
1854         /* Try to instantiate a bundle */
1855         err = xfrm_tmpl_resolve(pols, num_pols, fl, xfrm, family);
1856         if (err <= 0) {
1857                 if (err != 0 && err != -EAGAIN)
1858                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
1859                 return ERR_PTR(err);
1860         }
1861
1862         dst = xfrm_bundle_create(pols[0], xfrm, err, fl, dst_orig);
1863         if (IS_ERR(dst)) {
1864                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR);
1865                 return ERR_CAST(dst);
1866         }
1867
1868         xdst = (struct xfrm_dst *)dst;
1869         xdst->num_xfrms = err;
1870         xdst->num_pols = num_pols;
1871         memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
1872         xdst->policy_genid = atomic_read(&pols[0]->genid);
1873
1874         return xdst;
1875 }
1876
1877 static void xfrm_policy_queue_process(unsigned long arg)
1878 {
1879         struct sk_buff *skb;
1880         struct sock *sk;
1881         struct dst_entry *dst;
1882         struct xfrm_policy *pol = (struct xfrm_policy *)arg;
1883         struct net *net = xp_net(pol);
1884         struct xfrm_policy_queue *pq = &pol->polq;
1885         struct flowi fl;
1886         struct sk_buff_head list;
1887
1888         spin_lock(&pq->hold_queue.lock);
1889         skb = skb_peek(&pq->hold_queue);
1890         if (!skb) {
1891                 spin_unlock(&pq->hold_queue.lock);
1892                 goto out;
1893         }
1894         dst = skb_dst(skb);
1895         sk = skb->sk;
1896         xfrm_decode_session(skb, &fl, dst->ops->family);
1897         spin_unlock(&pq->hold_queue.lock);
1898
1899         dst_hold(dst->path);
1900         dst = xfrm_lookup(net, dst->path, &fl, sk, 0);
1901         if (IS_ERR(dst))
1902                 goto purge_queue;
1903
1904         if (dst->flags & DST_XFRM_QUEUE) {
1905                 dst_release(dst);
1906
1907                 if (pq->timeout >= XFRM_QUEUE_TMO_MAX)
1908                         goto purge_queue;
1909
1910                 pq->timeout = pq->timeout << 1;
1911                 if (!mod_timer(&pq->hold_timer, jiffies + pq->timeout))
1912                         xfrm_pol_hold(pol);
1913         goto out;
1914         }
1915
1916         dst_release(dst);
1917
1918         __skb_queue_head_init(&list);
1919
1920         spin_lock(&pq->hold_queue.lock);
1921         pq->timeout = 0;
1922         skb_queue_splice_init(&pq->hold_queue, &list);
1923         spin_unlock(&pq->hold_queue.lock);
1924
1925         while (!skb_queue_empty(&list)) {
1926                 skb = __skb_dequeue(&list);
1927
1928                 xfrm_decode_session(skb, &fl, skb_dst(skb)->ops->family);
1929                 dst_hold(skb_dst(skb)->path);
1930                 dst = xfrm_lookup(net, skb_dst(skb)->path, &fl, skb->sk, 0);
1931                 if (IS_ERR(dst)) {
1932                         kfree_skb(skb);
1933                         continue;
1934                 }
1935
1936                 nf_reset(skb);
1937                 skb_dst_drop(skb);
1938                 skb_dst_set(skb, dst);
1939
1940                 dst_output(net, skb->sk, skb);
1941         }
1942
1943 out:
1944         xfrm_pol_put(pol);
1945         return;
1946
1947 purge_queue:
1948         pq->timeout = 0;
1949         skb_queue_purge(&pq->hold_queue);
1950         xfrm_pol_put(pol);
1951 }
1952
1953 static int xdst_queue_output(struct net *net, struct sock *sk, struct sk_buff *skb)
1954 {
1955         unsigned long sched_next;
1956         struct dst_entry *dst = skb_dst(skb);
1957         struct xfrm_dst *xdst = (struct xfrm_dst *) dst;
1958         struct xfrm_policy *pol = xdst->pols[0];
1959         struct xfrm_policy_queue *pq = &pol->polq;
1960
1961         if (unlikely(skb_fclone_busy(sk, skb))) {
1962                 kfree_skb(skb);
1963                 return 0;
1964         }
1965
1966         if (pq->hold_queue.qlen > XFRM_MAX_QUEUE_LEN) {
1967                 kfree_skb(skb);
1968                 return -EAGAIN;
1969         }
1970
1971         skb_dst_force(skb);
1972
1973         spin_lock_bh(&pq->hold_queue.lock);
1974
1975         if (!pq->timeout)
1976                 pq->timeout = XFRM_QUEUE_TMO_MIN;
1977
1978         sched_next = jiffies + pq->timeout;
1979
1980         if (del_timer(&pq->hold_timer)) {
1981                 if (time_before(pq->hold_timer.expires, sched_next))
1982                         sched_next = pq->hold_timer.expires;
1983                 xfrm_pol_put(pol);
1984         }
1985
1986         __skb_queue_tail(&pq->hold_queue, skb);
1987         if (!mod_timer(&pq->hold_timer, sched_next))
1988                 xfrm_pol_hold(pol);
1989
1990         spin_unlock_bh(&pq->hold_queue.lock);
1991
1992         return 0;
1993 }
1994
1995 static struct xfrm_dst *xfrm_create_dummy_bundle(struct net *net,
1996                                                  struct xfrm_flo *xflo,
1997                                                  const struct flowi *fl,
1998                                                  int num_xfrms,
1999                                                  u16 family)
2000 {
2001         int err;
2002         struct net_device *dev;
2003         struct dst_entry *dst;
2004         struct dst_entry *dst1;
2005         struct xfrm_dst *xdst;
2006
2007         xdst = xfrm_alloc_dst(net, family);
2008         if (IS_ERR(xdst))
2009                 return xdst;
2010
2011         if (!(xflo->flags & XFRM_LOOKUP_QUEUE) ||
2012             net->xfrm.sysctl_larval_drop ||
2013             num_xfrms <= 0)
2014                 return xdst;
2015
2016         dst = xflo->dst_orig;
2017         dst1 = &xdst->u.dst;
2018         dst_hold(dst);
2019         xdst->route = dst;
2020
2021         dst_copy_metrics(dst1, dst);
2022
2023         dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
2024         dst1->flags |= DST_HOST | DST_XFRM_QUEUE;
2025         dst1->lastuse = jiffies;
2026
2027         dst1->input = dst_discard;
2028         dst1->output = xdst_queue_output;
2029
2030         dst_hold(dst);
2031         dst1->child = dst;
2032         dst1->path = dst;
2033
2034         xfrm_init_path((struct xfrm_dst *)dst1, dst, 0);
2035
2036         err = -ENODEV;
2037         dev = dst->dev;
2038         if (!dev)
2039                 goto free_dst;
2040
2041         err = xfrm_fill_dst(xdst, dev, fl);
2042         if (err)
2043                 goto free_dst;
2044
2045 out:
2046         return xdst;
2047
2048 free_dst:
2049         dst_release(dst1);
2050         xdst = ERR_PTR(err);
2051         goto out;
2052 }
2053
2054 static struct flow_cache_object *
2055 xfrm_bundle_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir,
2056                    struct flow_cache_object *oldflo, void *ctx)
2057 {
2058         struct xfrm_flo *xflo = (struct xfrm_flo *)ctx;
2059         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2060         struct xfrm_dst *xdst, *new_xdst;
2061         int num_pols = 0, num_xfrms = 0, i, err, pol_dead;
2062
2063         /* Check if the policies from old bundle are usable */
2064         xdst = NULL;
2065         if (oldflo) {
2066                 xdst = container_of(oldflo, struct xfrm_dst, flo);
2067                 num_pols = xdst->num_pols;
2068                 num_xfrms = xdst->num_xfrms;
2069                 pol_dead = 0;
2070                 for (i = 0; i < num_pols; i++) {
2071                         pols[i] = xdst->pols[i];
2072                         pol_dead |= pols[i]->walk.dead;
2073                 }
2074                 if (pol_dead) {
2075                         /* Mark DST_OBSOLETE_DEAD to fail the next
2076                          * xfrm_dst_check()
2077                          */
2078                         xdst->u.dst.obsolete = DST_OBSOLETE_DEAD;
2079                         dst_release_immediate(&xdst->u.dst);
2080                         xdst = NULL;
2081                         num_pols = 0;
2082                         num_xfrms = 0;
2083                         oldflo = NULL;
2084                 }
2085         }
2086
2087         /* Resolve policies to use if we couldn't get them from
2088          * previous cache entry */
2089         if (xdst == NULL) {
2090                 num_pols = 1;
2091                 pols[0] = __xfrm_policy_lookup(net, fl, family,
2092                                                flow_to_policy_dir(dir));
2093                 err = xfrm_expand_policies(fl, family, pols,
2094                                            &num_pols, &num_xfrms);
2095                 if (err < 0)
2096                         goto inc_error;
2097                 if (num_pols == 0)
2098                         return NULL;
2099                 if (num_xfrms <= 0)
2100                         goto make_dummy_bundle;
2101         }
2102
2103         new_xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family,
2104                                                   xflo->dst_orig);
2105         if (IS_ERR(new_xdst)) {
2106                 err = PTR_ERR(new_xdst);
2107                 if (err != -EAGAIN)
2108                         goto error;
2109                 if (oldflo == NULL)
2110                         goto make_dummy_bundle;
2111                 dst_hold(&xdst->u.dst);
2112                 return oldflo;
2113         } else if (new_xdst == NULL) {
2114                 num_xfrms = 0;
2115                 if (oldflo == NULL)
2116                         goto make_dummy_bundle;
2117                 xdst->num_xfrms = 0;
2118                 dst_hold(&xdst->u.dst);
2119                 return oldflo;
2120         }
2121
2122         /* Kill the previous bundle */
2123         if (xdst) {
2124                 /* The policies were stolen for newly generated bundle */
2125                 xdst->num_pols = 0;
2126                 /* Mark DST_OBSOLETE_DEAD to fail the next xfrm_dst_check() */
2127                 xdst->u.dst.obsolete = DST_OBSOLETE_DEAD;
2128                 dst_release_immediate(&xdst->u.dst);
2129         }
2130
2131         /* We do need to return one reference for original caller */
2132         dst_hold(&new_xdst->u.dst);
2133         return &new_xdst->flo;
2134
2135 make_dummy_bundle:
2136         /* We found policies, but there's no bundles to instantiate:
2137          * either because the policy blocks, has no transformations or
2138          * we could not build template (no xfrm_states).*/
2139         xdst = xfrm_create_dummy_bundle(net, xflo, fl, num_xfrms, family);
2140         if (IS_ERR(xdst)) {
2141                 xfrm_pols_put(pols, num_pols);
2142                 return ERR_CAST(xdst);
2143         }
2144         xdst->num_pols = num_pols;
2145         xdst->num_xfrms = num_xfrms;
2146         memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
2147
2148         dst_hold(&xdst->u.dst);
2149         return &xdst->flo;
2150
2151 inc_error:
2152         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
2153 error:
2154         if (xdst != NULL) {
2155                 /* Mark DST_OBSOLETE_DEAD to fail the next xfrm_dst_check() */
2156                 xdst->u.dst.obsolete = DST_OBSOLETE_DEAD;
2157                 dst_release_immediate(&xdst->u.dst);
2158         } else
2159                 xfrm_pols_put(pols, num_pols);
2160         return ERR_PTR(err);
2161 }
2162
2163 static struct dst_entry *make_blackhole(struct net *net, u16 family,
2164                                         struct dst_entry *dst_orig)
2165 {
2166         const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2167         struct dst_entry *ret;
2168
2169         if (!afinfo) {
2170                 dst_release(dst_orig);
2171                 return ERR_PTR(-EINVAL);
2172         } else {
2173                 ret = afinfo->blackhole_route(net, dst_orig);
2174         }
2175         rcu_read_unlock();
2176
2177         return ret;
2178 }
2179
2180 /* Main function: finds/creates a bundle for given flow.
2181  *
2182  * At the moment we eat a raw IP route. Mostly to speed up lookups
2183  * on interfaces with disabled IPsec.
2184  */
2185 struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
2186                               const struct flowi *fl,
2187                               const struct sock *sk, int flags)
2188 {
2189         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2190         struct flow_cache_object *flo;
2191         struct xfrm_dst *xdst;
2192         struct dst_entry *dst, *route;
2193         u16 family = dst_orig->ops->family;
2194         u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
2195         int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
2196
2197         dst = NULL;
2198         xdst = NULL;
2199         route = NULL;
2200
2201         sk = sk_const_to_full_sk(sk);
2202         if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
2203                 num_pols = 1;
2204                 pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, family);
2205                 err = xfrm_expand_policies(fl, family, pols,
2206                                            &num_pols, &num_xfrms);
2207                 if (err < 0)
2208                         goto dropdst;
2209
2210                 if (num_pols) {
2211                         if (num_xfrms <= 0) {
2212                                 drop_pols = num_pols;
2213                                 goto no_transform;
2214                         }
2215
2216                         xdst = xfrm_resolve_and_create_bundle(
2217                                         pols, num_pols, fl,
2218                                         family, dst_orig);
2219                         if (IS_ERR(xdst)) {
2220                                 xfrm_pols_put(pols, num_pols);
2221                                 err = PTR_ERR(xdst);
2222                                 goto dropdst;
2223                         } else if (xdst == NULL) {
2224                                 num_xfrms = 0;
2225                                 drop_pols = num_pols;
2226                                 goto no_transform;
2227                         }
2228
2229                         route = xdst->route;
2230                 }
2231         }
2232
2233         if (xdst == NULL) {
2234                 struct xfrm_flo xflo;
2235
2236                 xflo.dst_orig = dst_orig;
2237                 xflo.flags = flags;
2238
2239                 /* To accelerate a bit...  */
2240                 if ((dst_orig->flags & DST_NOXFRM) ||
2241                     !net->xfrm.policy_count[XFRM_POLICY_OUT])
2242                         goto nopol;
2243
2244                 flo = flow_cache_lookup(net, fl, family, dir,
2245                                         xfrm_bundle_lookup, &xflo);
2246                 if (flo == NULL)
2247                         goto nopol;
2248                 if (IS_ERR(flo)) {
2249                         err = PTR_ERR(flo);
2250                         goto dropdst;
2251                 }
2252                 xdst = container_of(flo, struct xfrm_dst, flo);
2253
2254                 num_pols = xdst->num_pols;
2255                 num_xfrms = xdst->num_xfrms;
2256                 memcpy(pols, xdst->pols, sizeof(struct xfrm_policy *) * num_pols);
2257                 route = xdst->route;
2258         }
2259
2260         dst = &xdst->u.dst;
2261         if (route == NULL && num_xfrms > 0) {
2262                 /* The only case when xfrm_bundle_lookup() returns a
2263                  * bundle with null route, is when the template could
2264                  * not be resolved. It means policies are there, but
2265                  * bundle could not be created, since we don't yet
2266                  * have the xfrm_state's. We need to wait for KM to
2267                  * negotiate new SA's or bail out with error.*/
2268                 if (net->xfrm.sysctl_larval_drop) {
2269                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
2270                         err = -EREMOTE;
2271                         goto error;
2272                 }
2273
2274                 err = -EAGAIN;
2275
2276                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
2277                 goto error;
2278         }
2279
2280 no_transform:
2281         if (num_pols == 0)
2282                 goto nopol;
2283
2284         if ((flags & XFRM_LOOKUP_ICMP) &&
2285             !(pols[0]->flags & XFRM_POLICY_ICMP)) {
2286                 err = -ENOENT;
2287                 goto error;
2288         }
2289
2290         for (i = 0; i < num_pols; i++)
2291                 pols[i]->curlft.use_time = get_seconds();
2292
2293         if (num_xfrms < 0) {
2294                 /* Prohibit the flow */
2295                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLBLOCK);
2296                 err = -EPERM;
2297                 goto error;
2298         } else if (num_xfrms > 0) {
2299                 /* Flow transformed */
2300                 dst_release(dst_orig);
2301         } else {
2302                 /* Flow passes untransformed */
2303                 dst_release(dst);
2304                 dst = dst_orig;
2305         }
2306 ok:
2307         xfrm_pols_put(pols, drop_pols);
2308         if (dst && dst->xfrm &&
2309             dst->xfrm->props.mode == XFRM_MODE_TUNNEL)
2310                 dst->flags |= DST_XFRM_TUNNEL;
2311         return dst;
2312
2313 nopol:
2314         if (!(flags & XFRM_LOOKUP_ICMP)) {
2315                 dst = dst_orig;
2316                 goto ok;
2317         }
2318         err = -ENOENT;
2319 error:
2320         dst_release(dst);
2321 dropdst:
2322         if (!(flags & XFRM_LOOKUP_KEEP_DST_REF))
2323                 dst_release(dst_orig);
2324         xfrm_pols_put(pols, drop_pols);
2325         return ERR_PTR(err);
2326 }
2327 EXPORT_SYMBOL(xfrm_lookup);
2328
2329 /* Callers of xfrm_lookup_route() must ensure a call to dst_output().
2330  * Otherwise we may send out blackholed packets.
2331  */
2332 struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
2333                                     const struct flowi *fl,
2334                                     const struct sock *sk, int flags)
2335 {
2336         struct dst_entry *dst = xfrm_lookup(net, dst_orig, fl, sk,
2337                                             flags | XFRM_LOOKUP_QUEUE |
2338                                             XFRM_LOOKUP_KEEP_DST_REF);
2339
2340         if (IS_ERR(dst) && PTR_ERR(dst) == -EREMOTE)
2341                 return make_blackhole(net, dst_orig->ops->family, dst_orig);
2342
2343         return dst;
2344 }
2345 EXPORT_SYMBOL(xfrm_lookup_route);
2346
2347 static inline int
2348 xfrm_secpath_reject(int idx, struct sk_buff *skb, const struct flowi *fl)
2349 {
2350         struct xfrm_state *x;
2351
2352         if (!skb->sp || idx < 0 || idx >= skb->sp->len)
2353                 return 0;
2354         x = skb->sp->xvec[idx];
2355         if (!x->type->reject)
2356                 return 0;
2357         return x->type->reject(x, skb, fl);
2358 }
2359
2360 /* When skb is transformed back to its "native" form, we have to
2361  * check policy restrictions. At the moment we make this in maximally
2362  * stupid way. Shame on me. :-) Of course, connected sockets must
2363  * have policy cached at them.
2364  */
2365
2366 static inline int
2367 xfrm_state_ok(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x,
2368               unsigned short family)
2369 {
2370         if (xfrm_state_kern(x))
2371                 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
2372         return  x->id.proto == tmpl->id.proto &&
2373                 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
2374                 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
2375                 x->props.mode == tmpl->mode &&
2376                 (tmpl->allalgs || (tmpl->aalgos & (1<<x->props.aalgo)) ||
2377                  !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
2378                 !(x->props.mode != XFRM_MODE_TRANSPORT &&
2379                   xfrm_state_addr_cmp(tmpl, x, family));
2380 }
2381
2382 /*
2383  * 0 or more than 0 is returned when validation is succeeded (either bypass
2384  * because of optional transport mode, or next index of the mathced secpath
2385  * state with the template.
2386  * -1 is returned when no matching template is found.
2387  * Otherwise "-2 - errored_index" is returned.
2388  */
2389 static inline int
2390 xfrm_policy_ok(const struct xfrm_tmpl *tmpl, const struct sec_path *sp, int start,
2391                unsigned short family)
2392 {
2393         int idx = start;
2394
2395         if (tmpl->optional) {
2396                 if (tmpl->mode == XFRM_MODE_TRANSPORT)
2397                         return start;
2398         } else
2399                 start = -1;
2400         for (; idx < sp->len; idx++) {
2401                 if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
2402                         return ++idx;
2403                 if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
2404                         if (start == -1)
2405                                 start = -2-idx;
2406                         break;
2407                 }
2408         }
2409         return start;
2410 }
2411
2412 int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
2413                           unsigned int family, int reverse)
2414 {
2415         const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2416         int err;
2417
2418         if (unlikely(afinfo == NULL))
2419                 return -EAFNOSUPPORT;
2420
2421         afinfo->decode_session(skb, fl, reverse);
2422         err = security_xfrm_decode_session(skb, &fl->flowi_secid);
2423         rcu_read_unlock();
2424         return err;
2425 }
2426 EXPORT_SYMBOL(__xfrm_decode_session);
2427
2428 static inline int secpath_has_nontransport(const struct sec_path *sp, int k, int *idxp)
2429 {
2430         for (; k < sp->len; k++) {
2431                 if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
2432                         *idxp = k;
2433                         return 1;
2434                 }
2435         }
2436
2437         return 0;
2438 }
2439
2440 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
2441                         unsigned short family)
2442 {
2443         struct net *net = dev_net(skb->dev);
2444         struct xfrm_policy *pol;
2445         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2446         int npols = 0;
2447         int xfrm_nr;
2448         int pi;
2449         int reverse;
2450         struct flowi fl;
2451         u8 fl_dir;
2452         int xerr_idx = -1;
2453
2454         reverse = dir & ~XFRM_POLICY_MASK;
2455         dir &= XFRM_POLICY_MASK;
2456         fl_dir = policy_to_flow_dir(dir);
2457
2458         if (__xfrm_decode_session(skb, &fl, family, reverse) < 0) {
2459                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
2460                 return 0;
2461         }
2462
2463         nf_nat_decode_session(skb, &fl, family);
2464
2465         /* First, check used SA against their selectors. */
2466         if (skb->sp) {
2467                 int i;
2468
2469                 for (i = skb->sp->len-1; i >= 0; i--) {
2470                         struct xfrm_state *x = skb->sp->xvec[i];
2471                         if (!xfrm_selector_match(&x->sel, &fl, family)) {
2472                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
2473                                 return 0;
2474                         }
2475                 }
2476         }
2477
2478         pol = NULL;
2479         sk = sk_to_full_sk(sk);
2480         if (sk && sk->sk_policy[dir]) {
2481                 pol = xfrm_sk_policy_lookup(sk, dir, &fl, family);
2482                 if (IS_ERR(pol)) {
2483                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2484                         return 0;
2485                 }
2486         }
2487
2488         if (!pol) {
2489                 struct flow_cache_object *flo;
2490
2491                 flo = flow_cache_lookup(net, &fl, family, fl_dir,
2492                                         xfrm_policy_lookup, NULL);
2493                 if (IS_ERR_OR_NULL(flo))
2494                         pol = ERR_CAST(flo);
2495                 else
2496                         pol = container_of(flo, struct xfrm_policy, flo);
2497         }
2498
2499         if (IS_ERR(pol)) {
2500                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2501                 return 0;
2502         }
2503
2504         if (!pol) {
2505                 if (skb->sp && secpath_has_nontransport(skb->sp, 0, &xerr_idx)) {
2506                         xfrm_secpath_reject(xerr_idx, skb, &fl);
2507                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
2508                         return 0;
2509                 }
2510                 return 1;
2511         }
2512
2513         pol->curlft.use_time = get_seconds();
2514
2515         pols[0] = pol;
2516         npols++;
2517 #ifdef CONFIG_XFRM_SUB_POLICY
2518         if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
2519                 pols[1] = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN,
2520                                                     &fl, family,
2521                                                     XFRM_POLICY_IN);
2522                 if (pols[1]) {
2523                         if (IS_ERR(pols[1])) {
2524                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2525                                 return 0;
2526                         }
2527                         pols[1]->curlft.use_time = get_seconds();
2528                         npols++;
2529                 }
2530         }
2531 #endif
2532
2533         if (pol->action == XFRM_POLICY_ALLOW) {
2534                 struct sec_path *sp;
2535                 static struct sec_path dummy;
2536                 struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
2537                 struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
2538                 struct xfrm_tmpl **tpp = tp;
2539                 int ti = 0;
2540                 int i, k;
2541
2542                 if ((sp = skb->sp) == NULL)
2543                         sp = &dummy;
2544
2545                 for (pi = 0; pi < npols; pi++) {
2546                         if (pols[pi] != pol &&
2547                             pols[pi]->action != XFRM_POLICY_ALLOW) {
2548                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2549                                 goto reject;
2550                         }
2551                         if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH) {
2552                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
2553                                 goto reject_error;
2554                         }
2555                         for (i = 0; i < pols[pi]->xfrm_nr; i++)
2556                                 tpp[ti++] = &pols[pi]->xfrm_vec[i];
2557                 }
2558                 xfrm_nr = ti;
2559                 if (npols > 1) {
2560                         xfrm_tmpl_sort(stp, tpp, xfrm_nr, family, net);
2561                         tpp = stp;
2562                 }
2563
2564                 /* For each tunnel xfrm, find the first matching tmpl.
2565                  * For each tmpl before that, find corresponding xfrm.
2566                  * Order is _important_. Later we will implement
2567                  * some barriers, but at the moment barriers
2568                  * are implied between each two transformations.
2569                  */
2570                 for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
2571                         k = xfrm_policy_ok(tpp[i], sp, k, family);
2572                         if (k < 0) {
2573                                 if (k < -1)
2574                                         /* "-2 - errored_index" returned */
2575                                         xerr_idx = -(2+k);
2576                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2577                                 goto reject;
2578                         }
2579                 }
2580
2581                 if (secpath_has_nontransport(sp, k, &xerr_idx)) {
2582                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2583                         goto reject;
2584                 }
2585
2586                 xfrm_pols_put(pols, npols);
2587                 return 1;
2588         }
2589         XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2590
2591 reject:
2592         xfrm_secpath_reject(xerr_idx, skb, &fl);
2593 reject_error:
2594         xfrm_pols_put(pols, npols);
2595         return 0;
2596 }
2597 EXPORT_SYMBOL(__xfrm_policy_check);
2598
2599 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
2600 {
2601         struct net *net = dev_net(skb->dev);
2602         struct flowi fl;
2603         struct dst_entry *dst;
2604         int res = 1;
2605
2606         if (xfrm_decode_session(skb, &fl, family) < 0) {
2607                 XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
2608                 return 0;
2609         }
2610
2611         skb_dst_force(skb);
2612
2613         dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, XFRM_LOOKUP_QUEUE);
2614         if (IS_ERR(dst)) {
2615                 res = 0;
2616                 dst = NULL;
2617         }
2618         skb_dst_set(skb, dst);
2619         return res;
2620 }
2621 EXPORT_SYMBOL(__xfrm_route_forward);
2622
2623 /* Optimize later using cookies and generation ids. */
2624
2625 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
2626 {
2627         /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
2628          * to DST_OBSOLETE_FORCE_CHK to force all XFRM destinations to
2629          * get validated by dst_ops->check on every use.  We do this
2630          * because when a normal route referenced by an XFRM dst is
2631          * obsoleted we do not go looking around for all parent
2632          * referencing XFRM dsts so that we can invalidate them.  It
2633          * is just too much work.  Instead we make the checks here on
2634          * every use.  For example:
2635          *
2636          *      XFRM dst A --> IPv4 dst X
2637          *
2638          * X is the "xdst->route" of A (X is also the "dst->path" of A
2639          * in this example).  If X is marked obsolete, "A" will not
2640          * notice.  That's what we are validating here via the
2641          * stale_bundle() check.
2642          *
2643          * When an xdst is removed from flow cache, DST_OBSOLETE_DEAD will
2644          * be marked on it.
2645          * When a dst is removed from the fib tree, DST_OBSOLETE_DEAD will
2646          * be marked on it.
2647          * Both will force stable_bundle() to fail on any xdst bundle with
2648          * this dst linked in it.
2649          */
2650         if (dst->obsolete < 0 && !stale_bundle(dst))
2651                 return dst;
2652
2653         return NULL;
2654 }
2655
2656 static int stale_bundle(struct dst_entry *dst)
2657 {
2658         return !xfrm_bundle_ok((struct xfrm_dst *)dst);
2659 }
2660
2661 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
2662 {
2663         while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
2664                 dst->dev = dev_net(dev)->loopback_dev;
2665                 dev_hold(dst->dev);
2666                 dev_put(dev);
2667         }
2668 }
2669 EXPORT_SYMBOL(xfrm_dst_ifdown);
2670
2671 static void xfrm_link_failure(struct sk_buff *skb)
2672 {
2673         /* Impossible. Such dst must be popped before reaches point of failure. */
2674 }
2675
2676 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
2677 {
2678         if (dst) {
2679                 if (dst->obsolete) {
2680                         dst_release(dst);
2681                         dst = NULL;
2682                 }
2683         }
2684         return dst;
2685 }
2686
2687 void xfrm_garbage_collect(struct net *net)
2688 {
2689         flow_cache_flush(net);
2690 }
2691 EXPORT_SYMBOL(xfrm_garbage_collect);
2692
2693 void xfrm_garbage_collect_deferred(struct net *net)
2694 {
2695         flow_cache_flush_deferred(net);
2696 }
2697 EXPORT_SYMBOL(xfrm_garbage_collect_deferred);
2698
2699 static void xfrm_init_pmtu(struct dst_entry *dst)
2700 {
2701         do {
2702                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2703                 u32 pmtu, route_mtu_cached;
2704
2705                 pmtu = dst_mtu(dst->child);
2706                 xdst->child_mtu_cached = pmtu;
2707
2708                 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
2709
2710                 route_mtu_cached = dst_mtu(xdst->route);
2711                 xdst->route_mtu_cached = route_mtu_cached;
2712
2713                 if (pmtu > route_mtu_cached)
2714                         pmtu = route_mtu_cached;
2715
2716                 dst_metric_set(dst, RTAX_MTU, pmtu);
2717         } while ((dst = dst->next));
2718 }
2719
2720 /* Check that the bundle accepts the flow and its components are
2721  * still valid.
2722  */
2723
2724 static int xfrm_bundle_ok(struct xfrm_dst *first)
2725 {
2726         struct dst_entry *dst = &first->u.dst;
2727         struct xfrm_dst *last;
2728         u32 mtu;
2729
2730         if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) ||
2731             (dst->dev && !netif_running(dst->dev)))
2732                 return 0;
2733
2734         if (dst->flags & DST_XFRM_QUEUE)
2735                 return 1;
2736
2737         last = NULL;
2738
2739         do {
2740                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2741
2742                 if (dst->xfrm->km.state != XFRM_STATE_VALID)
2743                         return 0;
2744                 if (xdst->xfrm_genid != dst->xfrm->genid)
2745                         return 0;
2746                 if (xdst->num_pols > 0 &&
2747                     xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
2748                         return 0;
2749
2750                 mtu = dst_mtu(dst->child);
2751                 if (xdst->child_mtu_cached != mtu) {
2752                         last = xdst;
2753                         xdst->child_mtu_cached = mtu;
2754                 }
2755
2756                 if (!dst_check(xdst->route, xdst->route_cookie))
2757                         return 0;
2758                 mtu = dst_mtu(xdst->route);
2759                 if (xdst->route_mtu_cached != mtu) {
2760                         last = xdst;
2761                         xdst->route_mtu_cached = mtu;
2762                 }
2763
2764                 dst = dst->child;
2765         } while (dst->xfrm);
2766
2767         if (likely(!last))
2768                 return 1;
2769
2770         mtu = last->child_mtu_cached;
2771         for (;;) {
2772                 dst = &last->u.dst;
2773
2774                 mtu = xfrm_state_mtu(dst->xfrm, mtu);
2775                 if (mtu > last->route_mtu_cached)
2776                         mtu = last->route_mtu_cached;
2777                 dst_metric_set(dst, RTAX_MTU, mtu);
2778
2779                 if (last == first)
2780                         break;
2781
2782                 last = (struct xfrm_dst *)last->u.dst.next;
2783                 last->child_mtu_cached = mtu;
2784         }
2785
2786         return 1;
2787 }
2788
2789 static unsigned int xfrm_default_advmss(const struct dst_entry *dst)
2790 {
2791         return dst_metric_advmss(dst->path);
2792 }
2793
2794 static unsigned int xfrm_mtu(const struct dst_entry *dst)
2795 {
2796         unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2797
2798         return mtu ? : dst_mtu(dst->path);
2799 }
2800
2801 static const void *xfrm_get_dst_nexthop(const struct dst_entry *dst,
2802                                         const void *daddr)
2803 {
2804         const struct dst_entry *path = dst->path;
2805
2806         for (; dst != path; dst = dst->child) {
2807                 const struct xfrm_state *xfrm = dst->xfrm;
2808
2809                 if (xfrm->props.mode == XFRM_MODE_TRANSPORT)
2810                         continue;
2811                 if (xfrm->type->flags & XFRM_TYPE_REMOTE_COADDR)
2812                         daddr = xfrm->coaddr;
2813                 else if (!(xfrm->type->flags & XFRM_TYPE_LOCAL_COADDR))
2814                         daddr = &xfrm->id.daddr;
2815         }
2816         return daddr;
2817 }
2818
2819 static struct neighbour *xfrm_neigh_lookup(const struct dst_entry *dst,
2820                                            struct sk_buff *skb,
2821                                            const void *daddr)
2822 {
2823         const struct dst_entry *path = dst->path;
2824
2825         if (!skb)
2826                 daddr = xfrm_get_dst_nexthop(dst, daddr);
2827         return path->ops->neigh_lookup(path, skb, daddr);
2828 }
2829
2830 static void xfrm_confirm_neigh(const struct dst_entry *dst, const void *daddr)
2831 {
2832         const struct dst_entry *path = dst->path;
2833
2834         daddr = xfrm_get_dst_nexthop(dst, daddr);
2835         path->ops->confirm_neigh(path, daddr);
2836 }
2837
2838 int xfrm_policy_register_afinfo(const struct xfrm_policy_afinfo *afinfo, int family)
2839 {
2840         int err = 0;
2841
2842         if (WARN_ON(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
2843                 return -EAFNOSUPPORT;
2844
2845         spin_lock(&xfrm_policy_afinfo_lock);
2846         if (unlikely(xfrm_policy_afinfo[family] != NULL))
2847                 err = -EEXIST;
2848         else {
2849                 struct dst_ops *dst_ops = afinfo->dst_ops;
2850                 if (likely(dst_ops->kmem_cachep == NULL))
2851                         dst_ops->kmem_cachep = xfrm_dst_cache;
2852                 if (likely(dst_ops->check == NULL))
2853                         dst_ops->check = xfrm_dst_check;
2854                 if (likely(dst_ops->default_advmss == NULL))
2855                         dst_ops->default_advmss = xfrm_default_advmss;
2856                 if (likely(dst_ops->mtu == NULL))
2857                         dst_ops->mtu = xfrm_mtu;
2858                 if (likely(dst_ops->negative_advice == NULL))
2859                         dst_ops->negative_advice = xfrm_negative_advice;
2860                 if (likely(dst_ops->link_failure == NULL))
2861                         dst_ops->link_failure = xfrm_link_failure;
2862                 if (likely(dst_ops->neigh_lookup == NULL))
2863                         dst_ops->neigh_lookup = xfrm_neigh_lookup;
2864                 if (likely(!dst_ops->confirm_neigh))
2865                         dst_ops->confirm_neigh = xfrm_confirm_neigh;
2866                 rcu_assign_pointer(xfrm_policy_afinfo[family], afinfo);
2867         }
2868         spin_unlock(&xfrm_policy_afinfo_lock);
2869
2870         return err;
2871 }
2872 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
2873
2874 void xfrm_policy_unregister_afinfo(const struct xfrm_policy_afinfo *afinfo)
2875 {
2876         struct dst_ops *dst_ops = afinfo->dst_ops;
2877         int i;
2878
2879         for (i = 0; i < ARRAY_SIZE(xfrm_policy_afinfo); i++) {
2880                 if (xfrm_policy_afinfo[i] != afinfo)
2881                         continue;
2882                 RCU_INIT_POINTER(xfrm_policy_afinfo[i], NULL);
2883                 break;
2884         }
2885
2886         synchronize_rcu();
2887
2888         dst_ops->kmem_cachep = NULL;
2889         dst_ops->check = NULL;
2890         dst_ops->negative_advice = NULL;
2891         dst_ops->link_failure = NULL;
2892 }
2893 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
2894
2895 #ifdef CONFIG_XFRM_STATISTICS
2896 static int __net_init xfrm_statistics_init(struct net *net)
2897 {
2898         int rv;
2899         net->mib.xfrm_statistics = alloc_percpu(struct linux_xfrm_mib);
2900         if (!net->mib.xfrm_statistics)
2901                 return -ENOMEM;
2902         rv = xfrm_proc_init(net);
2903         if (rv < 0)
2904                 free_percpu(net->mib.xfrm_statistics);
2905         return rv;
2906 }
2907
2908 static void xfrm_statistics_fini(struct net *net)
2909 {
2910         xfrm_proc_fini(net);
2911         free_percpu(net->mib.xfrm_statistics);
2912 }
2913 #else
2914 static int __net_init xfrm_statistics_init(struct net *net)
2915 {
2916         return 0;
2917 }
2918
2919 static void xfrm_statistics_fini(struct net *net)
2920 {
2921 }
2922 #endif
2923
2924 static int __net_init xfrm_policy_init(struct net *net)
2925 {
2926         unsigned int hmask, sz;
2927         int dir;
2928
2929         if (net_eq(net, &init_net))
2930                 xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
2931                                            sizeof(struct xfrm_dst),
2932                                            0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
2933                                            NULL);
2934
2935         hmask = 8 - 1;
2936         sz = (hmask+1) * sizeof(struct hlist_head);
2937
2938         net->xfrm.policy_byidx = xfrm_hash_alloc(sz);
2939         if (!net->xfrm.policy_byidx)
2940                 goto out_byidx;
2941         net->xfrm.policy_idx_hmask = hmask;
2942
2943         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
2944                 struct xfrm_policy_hash *htab;
2945
2946                 net->xfrm.policy_count[dir] = 0;
2947                 net->xfrm.policy_count[XFRM_POLICY_MAX + dir] = 0;
2948                 INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
2949
2950                 htab = &net->xfrm.policy_bydst[dir];
2951                 htab->table = xfrm_hash_alloc(sz);
2952                 if (!htab->table)
2953                         goto out_bydst;
2954                 htab->hmask = hmask;
2955                 htab->dbits4 = 32;
2956                 htab->sbits4 = 32;
2957                 htab->dbits6 = 128;
2958                 htab->sbits6 = 128;
2959         }
2960         net->xfrm.policy_hthresh.lbits4 = 32;
2961         net->xfrm.policy_hthresh.rbits4 = 32;
2962         net->xfrm.policy_hthresh.lbits6 = 128;
2963         net->xfrm.policy_hthresh.rbits6 = 128;
2964
2965         seqlock_init(&net->xfrm.policy_hthresh.lock);
2966
2967         INIT_LIST_HEAD(&net->xfrm.policy_all);
2968         INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
2969         INIT_WORK(&net->xfrm.policy_hthresh.work, xfrm_hash_rebuild);
2970         if (net_eq(net, &init_net))
2971                 xfrm_dev_init();
2972         return 0;
2973
2974 out_bydst:
2975         for (dir--; dir >= 0; dir--) {
2976                 struct xfrm_policy_hash *htab;
2977
2978                 htab = &net->xfrm.policy_bydst[dir];
2979                 xfrm_hash_free(htab->table, sz);
2980         }
2981         xfrm_hash_free(net->xfrm.policy_byidx, sz);
2982 out_byidx:
2983         return -ENOMEM;
2984 }
2985
2986 static void xfrm_policy_fini(struct net *net)
2987 {
2988         unsigned int sz;
2989         int dir;
2990
2991         flush_work(&net->xfrm.policy_hash_work);
2992 #ifdef CONFIG_XFRM_SUB_POLICY
2993         xfrm_policy_flush(net, XFRM_POLICY_TYPE_SUB, false);
2994 #endif
2995         xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, false);
2996
2997         WARN_ON(!list_empty(&net->xfrm.policy_all));
2998
2999         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
3000                 struct xfrm_policy_hash *htab;
3001
3002                 WARN_ON(!hlist_empty(&net->xfrm.policy_inexact[dir]));
3003
3004                 htab = &net->xfrm.policy_bydst[dir];
3005                 sz = (htab->hmask + 1) * sizeof(struct hlist_head);
3006                 WARN_ON(!hlist_empty(htab->table));
3007                 xfrm_hash_free(htab->table, sz);
3008         }
3009
3010         sz = (net->xfrm.policy_idx_hmask + 1) * sizeof(struct hlist_head);
3011         WARN_ON(!hlist_empty(net->xfrm.policy_byidx));
3012         xfrm_hash_free(net->xfrm.policy_byidx, sz);
3013 }
3014
3015 static int __net_init xfrm_net_init(struct net *net)
3016 {
3017         int rv;
3018
3019         /* Initialize the per-net locks here */
3020         spin_lock_init(&net->xfrm.xfrm_state_lock);
3021         spin_lock_init(&net->xfrm.xfrm_policy_lock);
3022         mutex_init(&net->xfrm.xfrm_cfg_mutex);
3023
3024         rv = xfrm_statistics_init(net);
3025         if (rv < 0)
3026                 goto out_statistics;
3027         rv = xfrm_state_init(net);
3028         if (rv < 0)
3029                 goto out_state;
3030         rv = xfrm_policy_init(net);
3031         if (rv < 0)
3032                 goto out_policy;
3033         rv = xfrm_sysctl_init(net);
3034         if (rv < 0)
3035                 goto out_sysctl;
3036         rv = flow_cache_init(net);
3037         if (rv < 0)
3038                 goto out;
3039
3040         return 0;
3041
3042 out:
3043         xfrm_sysctl_fini(net);
3044 out_sysctl:
3045         xfrm_policy_fini(net);
3046 out_policy:
3047         xfrm_state_fini(net);
3048 out_state:
3049         xfrm_statistics_fini(net);
3050 out_statistics:
3051         return rv;
3052 }
3053
3054 static void __net_exit xfrm_net_exit(struct net *net)
3055 {
3056         flow_cache_fini(net);
3057         xfrm_sysctl_fini(net);
3058         xfrm_policy_fini(net);
3059         xfrm_state_fini(net);
3060         xfrm_statistics_fini(net);
3061 }
3062
3063 static struct pernet_operations __net_initdata xfrm_net_ops = {
3064         .init = xfrm_net_init,
3065         .exit = xfrm_net_exit,
3066 };
3067
3068 void __init xfrm_init(void)
3069 {
3070         flow_cache_hp_init();
3071         register_pernet_subsys(&xfrm_net_ops);
3072         seqcount_init(&xfrm_policy_hash_generation);
3073         xfrm_input_init();
3074 }
3075
3076 #ifdef CONFIG_AUDITSYSCALL
3077 static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
3078                                          struct audit_buffer *audit_buf)
3079 {
3080         struct xfrm_sec_ctx *ctx = xp->security;
3081         struct xfrm_selector *sel = &xp->selector;
3082
3083         if (ctx)
3084                 audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
3085                                  ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str);
3086
3087         switch (sel->family) {
3088         case AF_INET:
3089                 audit_log_format(audit_buf, " src=%pI4", &sel->saddr.a4);
3090                 if (sel->prefixlen_s != 32)
3091                         audit_log_format(audit_buf, " src_prefixlen=%d",
3092                                          sel->prefixlen_s);
3093                 audit_log_format(audit_buf, " dst=%pI4", &sel->daddr.a4);
3094                 if (sel->prefixlen_d != 32)
3095                         audit_log_format(audit_buf, " dst_prefixlen=%d",
3096                                          sel->prefixlen_d);
3097                 break;
3098         case AF_INET6:
3099                 audit_log_format(audit_buf, " src=%pI6", sel->saddr.a6);
3100                 if (sel->prefixlen_s != 128)
3101                         audit_log_format(audit_buf, " src_prefixlen=%d",
3102                                          sel->prefixlen_s);
3103                 audit_log_format(audit_buf, " dst=%pI6", sel->daddr.a6);
3104                 if (sel->prefixlen_d != 128)
3105                         audit_log_format(audit_buf, " dst_prefixlen=%d",
3106                                          sel->prefixlen_d);
3107                 break;
3108         }
3109 }
3110
3111 void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid)
3112 {
3113         struct audit_buffer *audit_buf;
3114
3115         audit_buf = xfrm_audit_start("SPD-add");
3116         if (audit_buf == NULL)
3117                 return;
3118         xfrm_audit_helper_usrinfo(task_valid, audit_buf);
3119         audit_log_format(audit_buf, " res=%u", result);
3120         xfrm_audit_common_policyinfo(xp, audit_buf);
3121         audit_log_end(audit_buf);
3122 }
3123 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
3124
3125 void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
3126                               bool task_valid)
3127 {
3128         struct audit_buffer *audit_buf;
3129
3130         audit_buf = xfrm_audit_start("SPD-delete");
3131         if (audit_buf == NULL)
3132                 return;
3133         xfrm_audit_helper_usrinfo(task_valid, audit_buf);
3134         audit_log_format(audit_buf, " res=%u", result);
3135         xfrm_audit_common_policyinfo(xp, audit_buf);
3136         audit_log_end(audit_buf);
3137 }
3138 EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
3139 #endif
3140
3141 #ifdef CONFIG_XFRM_MIGRATE
3142 static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp,
3143                                         const struct xfrm_selector *sel_tgt)
3144 {
3145         if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
3146                 if (sel_tgt->family == sel_cmp->family &&
3147                     xfrm_addr_equal(&sel_tgt->daddr, &sel_cmp->daddr,
3148                                     sel_cmp->family) &&
3149                     xfrm_addr_equal(&sel_tgt->saddr, &sel_cmp->saddr,
3150                                     sel_cmp->family) &&
3151                     sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
3152                     sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
3153                         return true;
3154                 }
3155         } else {
3156                 if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
3157                         return true;
3158                 }
3159         }
3160         return false;
3161 }
3162
3163 static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector *sel,
3164                                                     u8 dir, u8 type, struct net *net)
3165 {
3166         struct xfrm_policy *pol, *ret = NULL;
3167         struct hlist_head *chain;
3168         u32 priority = ~0U;
3169
3170         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
3171         chain = policy_hash_direct(net, &sel->daddr, &sel->saddr, sel->family, dir);
3172         hlist_for_each_entry(pol, chain, bydst) {
3173                 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
3174                     pol->type == type) {
3175                         ret = pol;
3176                         priority = ret->priority;
3177                         break;
3178                 }
3179         }
3180         chain = &net->xfrm.policy_inexact[dir];
3181         hlist_for_each_entry(pol, chain, bydst) {
3182                 if ((pol->priority >= priority) && ret)
3183                         break;
3184
3185                 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
3186                     pol->type == type) {
3187                         ret = pol;
3188                         break;
3189                 }
3190         }
3191
3192         xfrm_pol_hold(ret);
3193
3194         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
3195
3196         return ret;
3197 }
3198
3199 static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t)
3200 {
3201         int match = 0;
3202
3203         if (t->mode == m->mode && t->id.proto == m->proto &&
3204             (m->reqid == 0 || t->reqid == m->reqid)) {
3205                 switch (t->mode) {
3206                 case XFRM_MODE_TUNNEL:
3207                 case XFRM_MODE_BEET:
3208                         if (xfrm_addr_equal(&t->id.daddr, &m->old_daddr,
3209                                             m->old_family) &&
3210                             xfrm_addr_equal(&t->saddr, &m->old_saddr,
3211                                             m->old_family)) {
3212                                 match = 1;
3213                         }
3214                         break;
3215                 case XFRM_MODE_TRANSPORT:
3216                         /* in case of transport mode, template does not store
3217                            any IP addresses, hence we just compare mode and
3218                            protocol */
3219                         match = 1;
3220                         break;
3221                 default:
3222                         break;
3223                 }
3224         }
3225         return match;
3226 }
3227
3228 /* update endpoint address(es) of template(s) */
3229 static int xfrm_policy_migrate(struct xfrm_policy *pol,
3230                                struct xfrm_migrate *m, int num_migrate)
3231 {
3232         struct xfrm_migrate *mp;
3233         int i, j, n = 0;
3234
3235         write_lock_bh(&pol->lock);
3236         if (unlikely(pol->walk.dead)) {
3237                 /* target policy has been deleted */
3238                 write_unlock_bh(&pol->lock);
3239                 return -ENOENT;
3240         }
3241
3242         for (i = 0; i < pol->xfrm_nr; i++) {
3243                 for (j = 0, mp = m; j < num_migrate; j++, mp++) {
3244                         if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
3245                                 continue;
3246                         n++;
3247                         if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
3248                             pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
3249                                 continue;
3250                         /* update endpoints */
3251                         memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
3252                                sizeof(pol->xfrm_vec[i].id.daddr));
3253                         memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
3254                                sizeof(pol->xfrm_vec[i].saddr));
3255                         pol->xfrm_vec[i].encap_family = mp->new_family;
3256                         /* flush bundles */
3257                         atomic_inc(&pol->genid);
3258                 }
3259         }
3260
3261         write_unlock_bh(&pol->lock);
3262
3263         if (!n)
3264                 return -ENODATA;
3265
3266         return 0;
3267 }
3268
3269 static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate)
3270 {
3271         int i, j;
3272
3273         if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
3274                 return -EINVAL;
3275
3276         for (i = 0; i < num_migrate; i++) {
3277                 if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
3278                     xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
3279                         return -EINVAL;
3280
3281                 /* check if there is any duplicated entry */
3282                 for (j = i + 1; j < num_migrate; j++) {
3283                         if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
3284                                     sizeof(m[i].old_daddr)) &&
3285                             !memcmp(&m[i].old_saddr, &m[j].old_saddr,
3286                                     sizeof(m[i].old_saddr)) &&
3287                             m[i].proto == m[j].proto &&
3288                             m[i].mode == m[j].mode &&
3289                             m[i].reqid == m[j].reqid &&
3290                             m[i].old_family == m[j].old_family)
3291                                 return -EINVAL;
3292                 }
3293         }
3294
3295         return 0;
3296 }
3297
3298 int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
3299                  struct xfrm_migrate *m, int num_migrate,
3300                  struct xfrm_kmaddress *k, struct net *net,
3301                  struct xfrm_encap_tmpl *encap)
3302 {
3303         int i, err, nx_cur = 0, nx_new = 0;
3304         struct xfrm_policy *pol = NULL;
3305         struct xfrm_state *x, *xc;
3306         struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
3307         struct xfrm_state *x_new[XFRM_MAX_DEPTH];
3308         struct xfrm_migrate *mp;
3309
3310         /* Stage 0 - sanity checks */
3311         if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
3312                 goto out;
3313
3314         if (dir >= XFRM_POLICY_MAX) {
3315                 err = -EINVAL;
3316                 goto out;
3317         }
3318
3319         /* Stage 1 - find policy */
3320         if ((pol = xfrm_migrate_policy_find(sel, dir, type, net)) == NULL) {
3321                 err = -ENOENT;
3322                 goto out;
3323         }
3324
3325         /* Stage 2 - find and update state(s) */
3326         for (i = 0, mp = m; i < num_migrate; i++, mp++) {
3327                 if ((x = xfrm_migrate_state_find(mp, net))) {
3328                         x_cur[nx_cur] = x;
3329                         nx_cur++;
3330                         xc = xfrm_state_migrate(x, mp, encap);
3331                         if (xc) {
3332                                 x_new[nx_new] = xc;
3333                                 nx_new++;
3334                         } else {
3335                                 err = -ENODATA;
3336                                 goto restore_state;
3337                         }
3338                 }
3339         }
3340
3341         /* Stage 3 - update policy */
3342         if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
3343                 goto restore_state;
3344
3345         /* Stage 4 - delete old state(s) */
3346         if (nx_cur) {
3347                 xfrm_states_put(x_cur, nx_cur);
3348                 xfrm_states_delete(x_cur, nx_cur);
3349         }
3350
3351         /* Stage 5 - announce */
3352         km_migrate(sel, dir, type, m, num_migrate, k, encap);
3353
3354         xfrm_pol_put(pol);
3355
3356         return 0;
3357 out:
3358         return err;
3359
3360 restore_state:
3361         if (pol)
3362                 xfrm_pol_put(pol);
3363         if (nx_cur)
3364                 xfrm_states_put(x_cur, nx_cur);
3365         if (nx_new)
3366                 xfrm_states_delete(x_new, nx_new);
3367
3368         return err;
3369 }
3370 EXPORT_SYMBOL(xfrm_migrate);
3371 #endif