net/xfrm/xfrm_policy.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * xfrm_policy.c
   4  *
   5  * Changes:
   6  *      Mitsuru KANDA @USAGI
   7  *      Kazunori MIYAZAWA @USAGI
   8  *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
   9  *              IPv6 support
  10  *      Kazunori MIYAZAWA @USAGI
  11  *      YOSHIFUJI Hideaki
  12  *              Split up af-specific portion
  13  *      Derek Atkins <derek@ihtfp.com>          Add the post_input processor
  14  *
  15  */
  16
  17 #include <linux/err.h>
  18 #include <linux/slab.h>
  19 #include <linux/kmod.h>
  20 #include <linux/list.h>
  21 #include <linux/spinlock.h>
  22 #include <linux/workqueue.h>
  23 #include <linux/notifier.h>
  24 #include <linux/netdevice.h>
  25 #include <linux/netfilter.h>
  26 #include <linux/module.h>
  27 #include <linux/cache.h>
  28 #include <linux/cpu.h>
  29 #include <linux/audit.h>
  30 #include <linux/rhashtable.h>
  31 #include <linux/if_tunnel.h>
  32 #include <net/dst.h>
  33 #include <net/flow.h>
  34 #include <net/inet_ecn.h>
  35 #include <net/xfrm.h>
  36 #include <net/ip.h>
  37 #include <net/gre.h>
  38 #if IS_ENABLED(CONFIG_IPV6_MIP6)
  39 #include <net/mip6.h>
  40 #endif
  41 #ifdef CONFIG_XFRM_STATISTICS
  42 #include <net/snmp.h>
  43 #endif
  44 #ifdef CONFIG_XFRM_ESPINTCP
  45 #include <net/espintcp.h>
  46 #endif
  47
  48 #include "xfrm_hash.h"
  49
  50 #define XFRM_QUEUE_TMO_MIN ((unsigned)(HZ/10))
  51 #define XFRM_QUEUE_TMO_MAX ((unsigned)(60*HZ))
  52 #define XFRM_MAX_QUEUE_LEN      100
  53
  54 struct xfrm_flo {
  55         struct dst_entry *dst_orig;
  56         u8 flags;
  57 };
  58
  59 /* prefixes smaller than this are stored in lists, not trees. */
  60 #define INEXACT_PREFIXLEN_IPV4  16
  61 #define INEXACT_PREFIXLEN_IPV6  48
  62
  63 struct xfrm_pol_inexact_node {
  64         struct rb_node node;
  65         union {
  66                 xfrm_address_t addr;
  67                 struct rcu_head rcu;
  68         };
  69         u8 prefixlen;
  70
  71         struct rb_root root;
  72
  73         /* the policies matching this node, can be empty list */
  74         struct hlist_head hhead;
  75 };
  76
  77 /* xfrm inexact policy search tree:
  78  * xfrm_pol_inexact_bin = hash(dir,type,family,if_id);
  79  *  |
  80  * +---- root_d: sorted by daddr:prefix
  81  * |                 |
  82  * |        xfrm_pol_inexact_node
  83  * |                 |
  84  * |                 +- root: sorted by saddr/prefix
  85  * |                 |              |
  86  * |                 |         xfrm_pol_inexact_node
  87  * |                 |              |
  88  * |                 |              + root: unused
  89  * |                 |              |
  90  * |                 |              + hhead: saddr:daddr policies
  91  * |                 |
  92  * |                 +- coarse policies and all any:daddr policies
  93  * |
  94  * +---- root_s: sorted by saddr:prefix
  95  * |                 |
  96  * |        xfrm_pol_inexact_node
  97  * |                 |
  98  * |                 + root: unused
  99  * |                 |
 100  * |                 + hhead: saddr:any policies
 101  * |
 102  * +---- coarse policies and all any:any policies
 103  *
 104  * Lookups return four candidate lists:
 105  * 1. any:any list from top-level xfrm_pol_inexact_bin
 106  * 2. any:daddr list from daddr tree
 107  * 3. saddr:daddr list from 2nd level daddr tree
 108  * 4. saddr:any list from saddr tree
 109  *
 110  * This result set then needs to be searched for the policy with
 111  * the lowest priority.  If two results have same prio, youngest one wins.
 112  */
 113
 114 struct xfrm_pol_inexact_key {
 115         possible_net_t net;
 116         u32 if_id;
 117         u16 family;
 118         u8 dir, type;
 119 };
 120
 121 struct xfrm_pol_inexact_bin {
 122         struct xfrm_pol_inexact_key k;
 123         struct rhash_head head;
 124         /* list containing '*:*' policies */
 125         struct hlist_head hhead;
 126
 127         seqcount_spinlock_t count;
 128         /* tree sorted by daddr/prefix */
 129         struct rb_root root_d;
 130
 131         /* tree sorted by saddr/prefix */
 132         struct rb_root root_s;
 133
 134         /* slow path below */
 135         struct list_head inexact_bins;
 136         struct rcu_head rcu;
 137 };
 138
 139 enum xfrm_pol_inexact_candidate_type {
 140         XFRM_POL_CAND_BOTH,
 141         XFRM_POL_CAND_SADDR,
 142         XFRM_POL_CAND_DADDR,
 143         XFRM_POL_CAND_ANY,
 144
 145         XFRM_POL_CAND_MAX,
 146 };
 147
 148 struct xfrm_pol_inexact_candidates {
 149         struct hlist_head *res[XFRM_POL_CAND_MAX];
 150 };
 151
 152 static DEFINE_SPINLOCK(xfrm_if_cb_lock);
 153 static struct xfrm_if_cb const __rcu *xfrm_if_cb __read_mostly;
 154
 155 static DEFINE_SPINLOCK(xfrm_policy_afinfo_lock);
 156 static struct xfrm_policy_afinfo const __rcu *xfrm_policy_afinfo[AF_INET6 + 1]
 157                                                 __read_mostly;
 158
 159 static struct kmem_cache *xfrm_dst_cache __ro_after_init;
 160
 161 static struct rhashtable xfrm_policy_inexact_table;
 162 static const struct rhashtable_params xfrm_pol_inexact_params;
 163
 164 static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr);
 165 static int stale_bundle(struct dst_entry *dst);
 166 static int xfrm_bundle_ok(struct xfrm_dst *xdst);
 167 static void xfrm_policy_queue_process(struct timer_list *t);
 168
 169 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir);
 170 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
 171                                                 int dir);
 172
 173 static struct xfrm_pol_inexact_bin *
 174 xfrm_policy_inexact_lookup(struct net *net, u8 type, u16 family, u8 dir,
 175                            u32 if_id);
 176
 177 static struct xfrm_pol_inexact_bin *
 178 xfrm_policy_inexact_lookup_rcu(struct net *net,
 179                                u8 type, u16 family, u8 dir, u32 if_id);
 180 static struct xfrm_policy *
 181 xfrm_policy_insert_list(struct hlist_head *chain, struct xfrm_policy *policy,
 182                         bool excl);
 183 static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
 184                                             struct xfrm_policy *policy);
 185
 186 static bool
 187 xfrm_policy_find_inexact_candidates(struct xfrm_pol_inexact_candidates *cand,
 188                                     struct xfrm_pol_inexact_bin *b,
 189                                     const xfrm_address_t *saddr,
 190                                     const xfrm_address_t *daddr);
 191
 192 static inline bool xfrm_pol_hold_rcu(struct xfrm_policy *policy)
 193 {
 194         return refcount_inc_not_zero(&policy->refcnt);
 195 }
 196
 197 static inline bool
 198 __xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
 199 {
 200         const struct flowi4 *fl4 = &fl->u.ip4;
 201
 202         return  addr4_match(fl4->daddr, sel->daddr.a4, sel->prefixlen_d) &&
 203                 addr4_match(fl4->saddr, sel->saddr.a4, sel->prefixlen_s) &&
 204                 !((xfrm_flowi_dport(fl, &fl4->uli) ^ sel->dport) & sel->dport_mask) &&
 205                 !((xfrm_flowi_sport(fl, &fl4->uli) ^ sel->sport) & sel->sport_mask) &&
 206                 (fl4->flowi4_proto == sel->proto || !sel->proto) &&
 207                 (fl4->flowi4_oif == sel->ifindex || !sel->ifindex);
 208 }
 209
 210 static inline bool
 211 __xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
 212 {
 213         const struct flowi6 *fl6 = &fl->u.ip6;
 214
 215         return  addr_match(&fl6->daddr, &sel->daddr, sel->prefixlen_d) &&
 216                 addr_match(&fl6->saddr, &sel->saddr, sel->prefixlen_s) &&
 217                 !((xfrm_flowi_dport(fl, &fl6->uli) ^ sel->dport) & sel->dport_mask) &&
 218                 !((xfrm_flowi_sport(fl, &fl6->uli) ^ sel->sport) & sel->sport_mask) &&
 219                 (fl6->flowi6_proto == sel->proto || !sel->proto) &&
 220                 (fl6->flowi6_oif == sel->ifindex || !sel->ifindex);
 221 }
 222
 223 bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl,
 224                          unsigned short family)
 225 {
 226         switch (family) {
 227         case AF_INET:
 228                 return __xfrm4_selector_match(sel, fl);
 229         case AF_INET6:
 230                 return __xfrm6_selector_match(sel, fl);
 231         }
 232         return false;
 233 }
 234
 235 static const struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
 236 {
 237         const struct xfrm_policy_afinfo *afinfo;
 238
 239         if (unlikely(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
 240                 return NULL;
 241         rcu_read_lock();
 242         afinfo = rcu_dereference(xfrm_policy_afinfo[family]);
 243         if (unlikely(!afinfo))
 244                 rcu_read_unlock();
 245         return afinfo;
 246 }
 247
 248 /* Called with rcu_read_lock(). */
 249 static const struct xfrm_if_cb *xfrm_if_get_cb(void)
 250 {
 251         return rcu_dereference(xfrm_if_cb);
 252 }
 253
 254 struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos, int oif,
 255                                     const xfrm_address_t *saddr,
 256                                     const xfrm_address_t *daddr,
 257                                     int family, u32 mark)
 258 {
 259         const struct xfrm_policy_afinfo *afinfo;
 260         struct dst_entry *dst;
 261
 262         afinfo = xfrm_policy_get_afinfo(family);
 263         if (unlikely(afinfo == NULL))
 264                 return ERR_PTR(-EAFNOSUPPORT);
 265
 266         dst = afinfo->dst_lookup(net, tos, oif, saddr, daddr, mark);
 267
 268         rcu_read_unlock();
 269
 270         return dst;
 271 }
 272 EXPORT_SYMBOL(__xfrm_dst_lookup);
 273
 274 static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x,
 275                                                 int tos, int oif,
 276                                                 xfrm_address_t *prev_saddr,
 277                                                 xfrm_address_t *prev_daddr,
 278                                                 int family, u32 mark)
 279 {
 280         struct net *net = xs_net(x);
 281         xfrm_address_t *saddr = &x->props.saddr;
 282         xfrm_address_t *daddr = &x->id.daddr;
 283         struct dst_entry *dst;
 284
 285         if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) {
 286                 saddr = x->coaddr;
 287                 daddr = prev_daddr;
 288         }
 289         if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) {
 290                 saddr = prev_saddr;
 291                 daddr = x->coaddr;
 292         }
 293
 294         dst = __xfrm_dst_lookup(net, tos, oif, saddr, daddr, family, mark);
 295
 296         if (!IS_ERR(dst)) {
 297                 if (prev_saddr != saddr)
 298                         memcpy(prev_saddr, saddr,  sizeof(*prev_saddr));
 299                 if (prev_daddr != daddr)
 300                         memcpy(prev_daddr, daddr,  sizeof(*prev_daddr));
 301         }
 302
 303         return dst;
 304 }
 305
 306 static inline unsigned long make_jiffies(long secs)
 307 {
 308         if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
 309                 return MAX_SCHEDULE_TIMEOUT-1;
 310         else
 311                 return secs*HZ;
 312 }
 313
 314 static void xfrm_policy_timer(struct timer_list *t)
 315 {
 316         struct xfrm_policy *xp = from_timer(xp, t, timer);
 317         time64_t now = ktime_get_real_seconds();
 318         time64_t next = TIME64_MAX;
 319         int warn = 0;
 320         int dir;
 321
 322         read_lock(&xp->lock);
 323
 324         if (unlikely(xp->walk.dead))
 325                 goto out;
 326
 327         dir = xfrm_policy_id2dir(xp->index);
 328
 329         if (xp->lft.hard_add_expires_seconds) {
 330                 time64_t tmo = xp->lft.hard_add_expires_seconds +
 331                         xp->curlft.add_time - now;
 332                 if (tmo <= 0)
 333                         goto expired;
 334                 if (tmo < next)
 335                         next = tmo;
 336         }
 337         if (xp->lft.hard_use_expires_seconds) {
 338                 time64_t tmo = xp->lft.hard_use_expires_seconds +
 339                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 340                 if (tmo <= 0)
 341                         goto expired;
 342                 if (tmo < next)
 343                         next = tmo;
 344         }
 345         if (xp->lft.soft_add_expires_seconds) {
 346                 time64_t tmo = xp->lft.soft_add_expires_seconds +
 347                         xp->curlft.add_time - now;
 348                 if (tmo <= 0) {
 349                         warn = 1;
 350                         tmo = XFRM_KM_TIMEOUT;
 351                 }
 352                 if (tmo < next)
 353                         next = tmo;
 354         }
 355         if (xp->lft.soft_use_expires_seconds) {
 356                 time64_t tmo = xp->lft.soft_use_expires_seconds +
 357                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 358                 if (tmo <= 0) {
 359                         warn = 1;
 360                         tmo = XFRM_KM_TIMEOUT;
 361                 }
 362                 if (tmo < next)
 363                         next = tmo;
 364         }
 365
 366         if (warn)
 367                 km_policy_expired(xp, dir, 0, 0);
 368         if (next != TIME64_MAX &&
 369             !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
 370                 xfrm_pol_hold(xp);
 371
 372 out:
 373         read_unlock(&xp->lock);
 374         xfrm_pol_put(xp);
 375         return;
 376
 377 expired:
 378         read_unlock(&xp->lock);
 379         if (!xfrm_policy_delete(xp, dir))
 380                 km_policy_expired(xp, dir, 1, 0);
 381         xfrm_pol_put(xp);
 382 }
 383
 384 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
 385  * SPD calls.
 386  */
 387
 388 struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
 389 {
 390         struct xfrm_policy *policy;
 391
 392         policy = kzalloc(sizeof(struct xfrm_policy), gfp);
 393
 394         if (policy) {
 395                 write_pnet(&policy->xp_net, net);
 396                 INIT_LIST_HEAD(&policy->walk.all);
 397                 INIT_HLIST_NODE(&policy->bydst_inexact_list);
 398                 INIT_HLIST_NODE(&policy->bydst);
 399                 INIT_HLIST_NODE(&policy->byidx);
 400                 rwlock_init(&policy->lock);
 401                 refcount_set(&policy->refcnt, 1);
 402                 skb_queue_head_init(&policy->polq.hold_queue);
 403                 timer_setup(&policy->timer, xfrm_policy_timer, 0);
 404                 timer_setup(&policy->polq.hold_timer,
 405                             xfrm_policy_queue_process, 0);
 406         }
 407         return policy;
 408 }
 409 EXPORT_SYMBOL(xfrm_policy_alloc);
 410
 411 static void xfrm_policy_destroy_rcu(struct rcu_head *head)
 412 {
 413         struct xfrm_policy *policy = container_of(head, struct xfrm_policy, rcu);
 414
 415         security_xfrm_policy_free(policy->security);
 416         kfree(policy);
 417 }
 418
 419 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
 420
 421 void xfrm_policy_destroy(struct xfrm_policy *policy)
 422 {
 423         BUG_ON(!policy->walk.dead);
 424
 425         if (del_timer(&policy->timer) || del_timer(&policy->polq.hold_timer))
 426                 BUG();
 427
 428         call_rcu(&policy->rcu, xfrm_policy_destroy_rcu);
 429 }
 430 EXPORT_SYMBOL(xfrm_policy_destroy);
 431
 432 /* Rule must be locked. Release descendant resources, announce
 433  * entry dead. The rule must be unlinked from lists to the moment.
 434  */
 435
 436 static void xfrm_policy_kill(struct xfrm_policy *policy)
 437 {
 438         write_lock_bh(&policy->lock);
 439         policy->walk.dead = 1;
 440         write_unlock_bh(&policy->lock);
 441
 442         atomic_inc(&policy->genid);
 443
 444         if (del_timer(&policy->polq.hold_timer))
 445                 xfrm_pol_put(policy);
 446         skb_queue_purge(&policy->polq.hold_queue);
 447
 448         if (del_timer(&policy->timer))
 449                 xfrm_pol_put(policy);
 450
 451         xfrm_pol_put(policy);
 452 }
 453
 454 static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
 455
 456 static inline unsigned int idx_hash(struct net *net, u32 index)
 457 {
 458         return __idx_hash(index, net->xfrm.policy_idx_hmask);
 459 }
 460
 461 /* calculate policy hash thresholds */
 462 static void __get_hash_thresh(struct net *net,
 463                               unsigned short family, int dir,
 464                               u8 *dbits, u8 *sbits)
 465 {
 466         switch (family) {
 467         case AF_INET:
 468                 *dbits = net->xfrm.policy_bydst[dir].dbits4;
 469                 *sbits = net->xfrm.policy_bydst[dir].sbits4;
 470                 break;
 471
 472         case AF_INET6:
 473                 *dbits = net->xfrm.policy_bydst[dir].dbits6;
 474                 *sbits = net->xfrm.policy_bydst[dir].sbits6;
 475                 break;
 476
 477         default:
 478                 *dbits = 0;
 479                 *sbits = 0;
 480         }
 481 }
 482
 483 static struct hlist_head *policy_hash_bysel(struct net *net,
 484                                             const struct xfrm_selector *sel,
 485                                             unsigned short family, int dir)
 486 {
 487         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 488         unsigned int hash;
 489         u8 dbits;
 490         u8 sbits;
 491
 492         __get_hash_thresh(net, family, dir, &dbits, &sbits);
 493         hash = __sel_hash(sel, family, hmask, dbits, sbits);
 494
 495         if (hash == hmask + 1)
 496                 return NULL;
 497
 498         return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
 499                      lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
 500 }
 501
 502 static struct hlist_head *policy_hash_direct(struct net *net,
 503                                              const xfrm_address_t *daddr,
 504                                              const xfrm_address_t *saddr,
 505                                              unsigned short family, int dir)
 506 {
 507         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 508         unsigned int hash;
 509         u8 dbits;
 510         u8 sbits;
 511
 512         __get_hash_thresh(net, family, dir, &dbits, &sbits);
 513         hash = __addr_hash(daddr, saddr, family, hmask, dbits, sbits);
 514
 515         return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
 516                      lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
 517 }
 518
 519 static void xfrm_dst_hash_transfer(struct net *net,
 520                                    struct hlist_head *list,
 521                                    struct hlist_head *ndsttable,
 522                                    unsigned int nhashmask,
 523                                    int dir)
 524 {
 525         struct hlist_node *tmp, *entry0 = NULL;
 526         struct xfrm_policy *pol;
 527         unsigned int h0 = 0;
 528         u8 dbits;
 529         u8 sbits;
 530
 531 redo:
 532         hlist_for_each_entry_safe(pol, tmp, list, bydst) {
 533                 unsigned int h;
 534
 535                 __get_hash_thresh(net, pol->family, dir, &dbits, &sbits);
 536                 h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
 537                                 pol->family, nhashmask, dbits, sbits);
 538                 if (!entry0) {
 539                         hlist_del_rcu(&pol->bydst);
 540                         hlist_add_head_rcu(&pol->bydst, ndsttable + h);
 541                         h0 = h;
 542                 } else {
 543                         if (h != h0)
 544                                 continue;
 545                         hlist_del_rcu(&pol->bydst);
 546                         hlist_add_behind_rcu(&pol->bydst, entry0);
 547                 }
 548                 entry0 = &pol->bydst;
 549         }
 550         if (!hlist_empty(list)) {
 551                 entry0 = NULL;
 552                 goto redo;
 553         }
 554 }
 555
 556 static void xfrm_idx_hash_transfer(struct hlist_head *list,
 557                                    struct hlist_head *nidxtable,
 558                                    unsigned int nhashmask)
 559 {
 560         struct hlist_node *tmp;
 561         struct xfrm_policy *pol;
 562
 563         hlist_for_each_entry_safe(pol, tmp, list, byidx) {
 564                 unsigned int h;
 565
 566                 h = __idx_hash(pol->index, nhashmask);
 567                 hlist_add_head(&pol->byidx, nidxtable+h);
 568         }
 569 }
 570
 571 static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
 572 {
 573         return ((old_hmask + 1) << 1) - 1;
 574 }
 575
 576 static void xfrm_bydst_resize(struct net *net, int dir)
 577 {
 578         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 579         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 580         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 581         struct hlist_head *ndst = xfrm_hash_alloc(nsize);
 582         struct hlist_head *odst;
 583         int i;
 584
 585         if (!ndst)
 586                 return;
 587
 588         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 589         write_seqcount_begin(&net->xfrm.xfrm_policy_hash_generation);
 590
 591         odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
 592                                 lockdep_is_held(&net->xfrm.xfrm_policy_lock));
 593
 594         for (i = hmask; i >= 0; i--)
 595                 xfrm_dst_hash_transfer(net, odst + i, ndst, nhashmask, dir);
 596
 597         rcu_assign_pointer(net->xfrm.policy_bydst[dir].table, ndst);
 598         net->xfrm.policy_bydst[dir].hmask = nhashmask;
 599
 600         write_seqcount_end(&net->xfrm.xfrm_policy_hash_generation);
 601         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 602
 603         synchronize_rcu();
 604
 605         xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
 606 }
 607
 608 static void xfrm_byidx_resize(struct net *net, int total)
 609 {
 610         unsigned int hmask = net->xfrm.policy_idx_hmask;
 611         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 612         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 613         struct hlist_head *oidx = net->xfrm.policy_byidx;
 614         struct hlist_head *nidx = xfrm_hash_alloc(nsize);
 615         int i;
 616
 617         if (!nidx)
 618                 return;
 619
 620         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 621
 622         for (i = hmask; i >= 0; i--)
 623                 xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
 624
 625         net->xfrm.policy_byidx = nidx;
 626         net->xfrm.policy_idx_hmask = nhashmask;
 627
 628         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 629
 630         xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
 631 }
 632
 633 static inline int xfrm_bydst_should_resize(struct net *net, int dir, int *total)
 634 {
 635         unsigned int cnt = net->xfrm.policy_count[dir];
 636         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 637
 638         if (total)
 639                 *total += cnt;
 640
 641         if ((hmask + 1) < xfrm_policy_hashmax &&
 642             cnt > hmask)
 643                 return 1;
 644
 645         return 0;
 646 }
 647
 648 static inline int xfrm_byidx_should_resize(struct net *net, int total)
 649 {
 650         unsigned int hmask = net->xfrm.policy_idx_hmask;
 651
 652         if ((hmask + 1) < xfrm_policy_hashmax &&
 653             total > hmask)
 654                 return 1;
 655
 656         return 0;
 657 }
 658
 659 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
 660 {
 661         si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
 662         si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
 663         si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
 664         si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
 665         si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
 666         si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
 667         si->spdhcnt = net->xfrm.policy_idx_hmask;
 668         si->spdhmcnt = xfrm_policy_hashmax;
 669 }
 670 EXPORT_SYMBOL(xfrm_spd_getinfo);
 671
 672 static DEFINE_MUTEX(hash_resize_mutex);
 673 static void xfrm_hash_resize(struct work_struct *work)
 674 {
 675         struct net *net = container_of(work, struct net, xfrm.policy_hash_work);
 676         int dir, total;
 677
 678         mutex_lock(&hash_resize_mutex);
 679
 680         total = 0;
 681         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 682                 if (xfrm_bydst_should_resize(net, dir, &total))
 683                         xfrm_bydst_resize(net, dir);
 684         }
 685         if (xfrm_byidx_should_resize(net, total))
 686                 xfrm_byidx_resize(net, total);
 687
 688         mutex_unlock(&hash_resize_mutex);
 689 }
 690
 691 /* Make sure *pol can be inserted into fastbin.
 692  * Useful to check that later insert requests will be successful
 693  * (provided xfrm_policy_lock is held throughout).
 694  */
 695 static struct xfrm_pol_inexact_bin *
 696 xfrm_policy_inexact_alloc_bin(const struct xfrm_policy *pol, u8 dir)
 697 {
 698         struct xfrm_pol_inexact_bin *bin, *prev;
 699         struct xfrm_pol_inexact_key k = {
 700                 .family = pol->family,
 701                 .type = pol->type,
 702                 .dir = dir,
 703                 .if_id = pol->if_id,
 704         };
 705         struct net *net = xp_net(pol);
 706
 707         lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
 708
 709         write_pnet(&k.net, net);
 710         bin = rhashtable_lookup_fast(&xfrm_policy_inexact_table, &k,
 711                                      xfrm_pol_inexact_params);
 712         if (bin)
 713                 return bin;
 714
 715         bin = kzalloc(sizeof(*bin), GFP_ATOMIC);
 716         if (!bin)
 717                 return NULL;
 718
 719         bin->k = k;
 720         INIT_HLIST_HEAD(&bin->hhead);
 721         bin->root_d = RB_ROOT;
 722         bin->root_s = RB_ROOT;
 723         seqcount_spinlock_init(&bin->count, &net->xfrm.xfrm_policy_lock);
 724
 725         prev = rhashtable_lookup_get_insert_key(&xfrm_policy_inexact_table,
 726                                                 &bin->k, &bin->head,
 727                                                 xfrm_pol_inexact_params);
 728         if (!prev) {
 729                 list_add(&bin->inexact_bins, &net->xfrm.inexact_bins);
 730                 return bin;
 731         }
 732
 733         kfree(bin);
 734
 735         return IS_ERR(prev) ? NULL : prev;
 736 }
 737
 738 static bool xfrm_pol_inexact_addr_use_any_list(const xfrm_address_t *addr,
 739                                                int family, u8 prefixlen)
 740 {
 741         if (xfrm_addr_any(addr, family))
 742                 return true;
 743
 744         if (family == AF_INET6 && prefixlen < INEXACT_PREFIXLEN_IPV6)
 745                 return true;
 746
 747         if (family == AF_INET && prefixlen < INEXACT_PREFIXLEN_IPV4)
 748                 return true;
 749
 750         return false;
 751 }
 752
 753 static bool
 754 xfrm_policy_inexact_insert_use_any_list(const struct xfrm_policy *policy)
 755 {
 756         const xfrm_address_t *addr;
 757         bool saddr_any, daddr_any;
 758         u8 prefixlen;
 759
 760         addr = &policy->selector.saddr;
 761         prefixlen = policy->selector.prefixlen_s;
 762
 763         saddr_any = xfrm_pol_inexact_addr_use_any_list(addr,
 764                                                        policy->family,
 765                                                        prefixlen);
 766         addr = &policy->selector.daddr;
 767         prefixlen = policy->selector.prefixlen_d;
 768         daddr_any = xfrm_pol_inexact_addr_use_any_list(addr,
 769                                                        policy->family,
 770                                                        prefixlen);
 771         return saddr_any && daddr_any;
 772 }
 773
 774 static void xfrm_pol_inexact_node_init(struct xfrm_pol_inexact_node *node,
 775                                        const xfrm_address_t *addr, u8 prefixlen)
 776 {
 777         node->addr = *addr;
 778         node->prefixlen = prefixlen;
 779 }
 780
 781 static struct xfrm_pol_inexact_node *
 782 xfrm_pol_inexact_node_alloc(const xfrm_address_t *addr, u8 prefixlen)
 783 {
 784         struct xfrm_pol_inexact_node *node;
 785
 786         node = kzalloc(sizeof(*node), GFP_ATOMIC);
 787         if (node)
 788                 xfrm_pol_inexact_node_init(node, addr, prefixlen);
 789
 790         return node;
 791 }
 792
 793 static int xfrm_policy_addr_delta(const xfrm_address_t *a,
 794                                   const xfrm_address_t *b,
 795                                   u8 prefixlen, u16 family)
 796 {
 797         u32 ma, mb, mask;
 798         unsigned int pdw, pbi;
 799         int delta = 0;
 800
 801         switch (family) {
 802         case AF_INET:
 803                 if (prefixlen == 0)
 804                         return 0;
 805                 mask = ~0U << (32 - prefixlen);
 806                 ma = ntohl(a->a4) & mask;
 807                 mb = ntohl(b->a4) & mask;
 808                 if (ma < mb)
 809                         delta = -1;
 810                 else if (ma > mb)
 811                         delta = 1;
 812                 break;
 813         case AF_INET6:
 814                 pdw = prefixlen >> 5;
 815                 pbi = prefixlen & 0x1f;
 816
 817                 if (pdw) {
 818                         delta = memcmp(a->a6, b->a6, pdw << 2);
 819                         if (delta)
 820                                 return delta;
 821                 }
 822                 if (pbi) {
 823                         mask = ~0U << (32 - pbi);
 824                         ma = ntohl(a->a6[pdw]) & mask;
 825                         mb = ntohl(b->a6[pdw]) & mask;
 826                         if (ma < mb)
 827                                 delta = -1;
 828                         else if (ma > mb)
 829                                 delta = 1;
 830                 }
 831                 break;
 832         default:
 833                 break;
 834         }
 835
 836         return delta;
 837 }
 838
 839 static void xfrm_policy_inexact_list_reinsert(struct net *net,
 840                                               struct xfrm_pol_inexact_node *n,
 841                                               u16 family)
 842 {
 843         unsigned int matched_s, matched_d;
 844         struct xfrm_policy *policy, *p;
 845
 846         matched_s = 0;
 847         matched_d = 0;
 848
 849         list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
 850                 struct hlist_node *newpos = NULL;
 851                 bool matches_s, matches_d;
 852
 853                 if (!policy->bydst_reinsert)
 854                         continue;
 855
 856                 WARN_ON_ONCE(policy->family != family);
 857
 858                 policy->bydst_reinsert = false;
 859                 hlist_for_each_entry(p, &n->hhead, bydst) {
 860                         if (policy->priority > p->priority)
 861                                 newpos = &p->bydst;
 862                         else if (policy->priority == p->priority &&
 863                                  policy->pos > p->pos)
 864                                 newpos = &p->bydst;
 865                         else
 866                                 break;
 867                 }
 868
 869                 if (newpos)
 870                         hlist_add_behind_rcu(&policy->bydst, newpos);
 871                 else
 872                         hlist_add_head_rcu(&policy->bydst, &n->hhead);
 873
 874                 /* paranoia checks follow.
 875                  * Check that the reinserted policy matches at least
 876                  * saddr or daddr for current node prefix.
 877                  *
 878                  * Matching both is fine, matching saddr in one policy
 879                  * (but not daddr) and then matching only daddr in another
 880                  * is a bug.
 881                  */
 882                 matches_s = xfrm_policy_addr_delta(&policy->selector.saddr,
 883                                                    &n->addr,
 884                                                    n->prefixlen,
 885                                                    family) == 0;
 886                 matches_d = xfrm_policy_addr_delta(&policy->selector.daddr,
 887                                                    &n->addr,
 888                                                    n->prefixlen,
 889                                                    family) == 0;
 890                 if (matches_s && matches_d)
 891                         continue;
 892
 893                 WARN_ON_ONCE(!matches_s && !matches_d);
 894                 if (matches_s)
 895                         matched_s++;
 896                 if (matches_d)
 897                         matched_d++;
 898                 WARN_ON_ONCE(matched_s && matched_d);
 899         }
 900 }
 901
 902 static void xfrm_policy_inexact_node_reinsert(struct net *net,
 903                                               struct xfrm_pol_inexact_node *n,
 904                                               struct rb_root *new,
 905                                               u16 family)
 906 {
 907         struct xfrm_pol_inexact_node *node;
 908         struct rb_node **p, *parent;
 909
 910         /* we should not have another subtree here */
 911         WARN_ON_ONCE(!RB_EMPTY_ROOT(&n->root));
 912 restart:
 913         parent = NULL;
 914         p = &new->rb_node;
 915         while (*p) {
 916                 u8 prefixlen;
 917                 int delta;
 918
 919                 parent = *p;
 920                 node = rb_entry(*p, struct xfrm_pol_inexact_node, node);
 921
 922                 prefixlen = min(node->prefixlen, n->prefixlen);
 923
 924                 delta = xfrm_policy_addr_delta(&n->addr, &node->addr,
 925                                                prefixlen, family);
 926                 if (delta < 0) {
 927                         p = &parent->rb_left;
 928                 } else if (delta > 0) {
 929                         p = &parent->rb_right;
 930                 } else {
 931                         bool same_prefixlen = node->prefixlen == n->prefixlen;
 932                         struct xfrm_policy *tmp;
 933
 934                         hlist_for_each_entry(tmp, &n->hhead, bydst) {
 935                                 tmp->bydst_reinsert = true;
 936                                 hlist_del_rcu(&tmp->bydst);
 937                         }
 938
 939                         node->prefixlen = prefixlen;
 940
 941                         xfrm_policy_inexact_list_reinsert(net, node, family);
 942
 943                         if (same_prefixlen) {
 944                                 kfree_rcu(n, rcu);
 945                                 return;
 946                         }
 947
 948                         rb_erase(*p, new);
 949                         kfree_rcu(n, rcu);
 950                         n = node;
 951                         goto restart;
 952                 }
 953         }
 954
 955         rb_link_node_rcu(&n->node, parent, p);
 956         rb_insert_color(&n->node, new);
 957 }
 958
 959 /* merge nodes v and n */
 960 static void xfrm_policy_inexact_node_merge(struct net *net,
 961                                            struct xfrm_pol_inexact_node *v,
 962                                            struct xfrm_pol_inexact_node *n,
 963                                            u16 family)
 964 {
 965         struct xfrm_pol_inexact_node *node;
 966         struct xfrm_policy *tmp;
 967         struct rb_node *rnode;
 968
 969         /* To-be-merged node v has a subtree.
 970          *
 971          * Dismantle it and insert its nodes to n->root.
 972          */
 973         while ((rnode = rb_first(&v->root)) != NULL) {
 974                 node = rb_entry(rnode, struct xfrm_pol_inexact_node, node);
 975                 rb_erase(&node->node, &v->root);
 976                 xfrm_policy_inexact_node_reinsert(net, node, &n->root,
 977                                                   family);
 978         }
 979
 980         hlist_for_each_entry(tmp, &v->hhead, bydst) {
 981                 tmp->bydst_reinsert = true;
 982                 hlist_del_rcu(&tmp->bydst);
 983         }
 984
 985         xfrm_policy_inexact_list_reinsert(net, n, family);
 986 }
 987
 988 static struct xfrm_pol_inexact_node *
 989 xfrm_policy_inexact_insert_node(struct net *net,
 990                                 struct rb_root *root,
 991                                 xfrm_address_t *addr,
 992                                 u16 family, u8 prefixlen, u8 dir)
 993 {
 994         struct xfrm_pol_inexact_node *cached = NULL;
 995         struct rb_node **p, *parent = NULL;
 996         struct xfrm_pol_inexact_node *node;
 997
 998         p = &root->rb_node;
 999         while (*p) {
1000                 int delta;
1001
1002                 parent = *p;
1003                 node = rb_entry(*p, struct xfrm_pol_inexact_node, node);
1004
1005                 delta = xfrm_policy_addr_delta(addr, &node->addr,
1006                                                node->prefixlen,
1007                                                family);
1008                 if (delta == 0 && prefixlen >= node->prefixlen) {
1009                         WARN_ON_ONCE(cached); /* ipsec policies got lost */
1010                         return node;
1011                 }
1012
1013                 if (delta < 0)
1014                         p = &parent->rb_left;
1015                 else
1016                         p = &parent->rb_right;
1017
1018                 if (prefixlen < node->prefixlen) {
1019                         delta = xfrm_policy_addr_delta(addr, &node->addr,
1020                                                        prefixlen,
1021                                                        family);
1022                         if (delta)
1023                                 continue;
1024
1025                         /* This node is a subnet of the new prefix. It needs
1026                          * to be removed and re-inserted with the smaller
1027                          * prefix and all nodes that are now also covered
1028                          * by the reduced prefixlen.
1029                          */
1030                         rb_erase(&node->node, root);
1031
1032                         if (!cached) {
1033                                 xfrm_pol_inexact_node_init(node, addr,
1034                                                            prefixlen);
1035                                 cached = node;
1036                         } else {
1037                                 /* This node also falls within the new
1038                                  * prefixlen. Merge the to-be-reinserted
1039                                  * node and this one.
1040                                  */
1041                                 xfrm_policy_inexact_node_merge(net, node,
1042                                                                cached, family);
1043                                 kfree_rcu(node, rcu);
1044                         }
1045
1046                         /* restart */
1047                         p = &root->rb_node;
1048                         parent = NULL;
1049                 }
1050         }
1051
1052         node = cached;
1053         if (!node) {
1054                 node = xfrm_pol_inexact_node_alloc(addr, prefixlen);
1055                 if (!node)
1056                         return NULL;
1057         }
1058
1059         rb_link_node_rcu(&node->node, parent, p);
1060         rb_insert_color(&node->node, root);
1061
1062         return node;
1063 }
1064
1065 static void xfrm_policy_inexact_gc_tree(struct rb_root *r, bool rm)
1066 {
1067         struct xfrm_pol_inexact_node *node;
1068         struct rb_node *rn = rb_first(r);
1069
1070         while (rn) {
1071                 node = rb_entry(rn, struct xfrm_pol_inexact_node, node);
1072
1073                 xfrm_policy_inexact_gc_tree(&node->root, rm);
1074                 rn = rb_next(rn);
1075
1076                 if (!hlist_empty(&node->hhead) || !RB_EMPTY_ROOT(&node->root)) {
1077                         WARN_ON_ONCE(rm);
1078                         continue;
1079                 }
1080
1081                 rb_erase(&node->node, r);
1082                 kfree_rcu(node, rcu);
1083         }
1084 }
1085
1086 static void __xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin *b, bool net_exit)
1087 {
1088         write_seqcount_begin(&b->count);
1089         xfrm_policy_inexact_gc_tree(&b->root_d, net_exit);
1090         xfrm_policy_inexact_gc_tree(&b->root_s, net_exit);
1091         write_seqcount_end(&b->count);
1092
1093         if (!RB_EMPTY_ROOT(&b->root_d) || !RB_EMPTY_ROOT(&b->root_s) ||
1094             !hlist_empty(&b->hhead)) {
1095                 WARN_ON_ONCE(net_exit);
1096                 return;
1097         }
1098
1099         if (rhashtable_remove_fast(&xfrm_policy_inexact_table, &b->head,
1100                                    xfrm_pol_inexact_params) == 0) {
1101                 list_del(&b->inexact_bins);
1102                 kfree_rcu(b, rcu);
1103         }
1104 }
1105
1106 static void xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin *b)
1107 {
1108         struct net *net = read_pnet(&b->k.net);
1109
1110         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1111         __xfrm_policy_inexact_prune_bin(b, false);
1112         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1113 }
1114
1115 static void __xfrm_policy_inexact_flush(struct net *net)
1116 {
1117         struct xfrm_pol_inexact_bin *bin, *t;
1118
1119         lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1120
1121         list_for_each_entry_safe(bin, t, &net->xfrm.inexact_bins, inexact_bins)
1122                 __xfrm_policy_inexact_prune_bin(bin, false);
1123 }
1124
1125 static struct hlist_head *
1126 xfrm_policy_inexact_alloc_chain(struct xfrm_pol_inexact_bin *bin,
1127                                 struct xfrm_policy *policy, u8 dir)
1128 {
1129         struct xfrm_pol_inexact_node *n;
1130         struct net *net;
1131
1132         net = xp_net(policy);
1133         lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1134
1135         if (xfrm_policy_inexact_insert_use_any_list(policy))
1136                 return &bin->hhead;
1137
1138         if (xfrm_pol_inexact_addr_use_any_list(&policy->selector.daddr,
1139                                                policy->family,
1140                                                policy->selector.prefixlen_d)) {
1141                 write_seqcount_begin(&bin->count);
1142                 n = xfrm_policy_inexact_insert_node(net,
1143                                                     &bin->root_s,
1144                                                     &policy->selector.saddr,
1145                                                     policy->family,
1146                                                     policy->selector.prefixlen_s,
1147                                                     dir);
1148                 write_seqcount_end(&bin->count);
1149                 if (!n)
1150                         return NULL;
1151
1152                 return &n->hhead;
1153         }
1154
1155         /* daddr is fixed */
1156         write_seqcount_begin(&bin->count);
1157         n = xfrm_policy_inexact_insert_node(net,
1158                                             &bin->root_d,
1159                                             &policy->selector.daddr,
1160                                             policy->family,
1161                                             policy->selector.prefixlen_d, dir);
1162         write_seqcount_end(&bin->count);
1163         if (!n)
1164                 return NULL;
1165
1166         /* saddr is wildcard */
1167         if (xfrm_pol_inexact_addr_use_any_list(&policy->selector.saddr,
1168                                                policy->family,
1169                                                policy->selector.prefixlen_s))
1170                 return &n->hhead;
1171
1172         write_seqcount_begin(&bin->count);
1173         n = xfrm_policy_inexact_insert_node(net,
1174                                             &n->root,
1175                                             &policy->selector.saddr,
1176                                             policy->family,
1177                                             policy->selector.prefixlen_s, dir);
1178         write_seqcount_end(&bin->count);
1179         if (!n)
1180                 return NULL;
1181
1182         return &n->hhead;
1183 }
1184
1185 static struct xfrm_policy *
1186 xfrm_policy_inexact_insert(struct xfrm_policy *policy, u8 dir, int excl)
1187 {
1188         struct xfrm_pol_inexact_bin *bin;
1189         struct xfrm_policy *delpol;
1190         struct hlist_head *chain;
1191         struct net *net;
1192
1193         bin = xfrm_policy_inexact_alloc_bin(policy, dir);
1194         if (!bin)
1195                 return ERR_PTR(-ENOMEM);
1196
1197         net = xp_net(policy);
1198         lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
1199
1200         chain = xfrm_policy_inexact_alloc_chain(bin, policy, dir);
1201         if (!chain) {
1202                 __xfrm_policy_inexact_prune_bin(bin, false);
1203                 return ERR_PTR(-ENOMEM);
1204         }
1205
1206         delpol = xfrm_policy_insert_list(chain, policy, excl);
1207         if (delpol && excl) {
1208                 __xfrm_policy_inexact_prune_bin(bin, false);
1209                 return ERR_PTR(-EEXIST);
1210         }
1211
1212         chain = &net->xfrm.policy_inexact[dir];
1213         xfrm_policy_insert_inexact_list(chain, policy);
1214
1215         if (delpol)
1216                 __xfrm_policy_inexact_prune_bin(bin, false);
1217
1218         return delpol;
1219 }
1220
1221 static void xfrm_hash_rebuild(struct work_struct *work)
1222 {
1223         struct net *net = container_of(work, struct net,
1224                                        xfrm.policy_hthresh.work);
1225         unsigned int hmask;
1226         struct xfrm_policy *pol;
1227         struct xfrm_policy *policy;
1228         struct hlist_head *chain;
1229         struct hlist_head *odst;
1230         struct hlist_node *newpos;
1231         int i;
1232         int dir;
1233         unsigned seq;
1234         u8 lbits4, rbits4, lbits6, rbits6;
1235
1236         mutex_lock(&hash_resize_mutex);
1237
1238         /* read selector prefixlen thresholds */
1239         do {
1240                 seq = read_seqbegin(&net->xfrm.policy_hthresh.lock);
1241
1242                 lbits4 = net->xfrm.policy_hthresh.lbits4;
1243                 rbits4 = net->xfrm.policy_hthresh.rbits4;
1244                 lbits6 = net->xfrm.policy_hthresh.lbits6;
1245                 rbits6 = net->xfrm.policy_hthresh.rbits6;
1246         } while (read_seqretry(&net->xfrm.policy_hthresh.lock, seq));
1247
1248         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1249         write_seqcount_begin(&net->xfrm.xfrm_policy_hash_generation);
1250
1251         /* make sure that we can insert the indirect policies again before
1252          * we start with destructive action.
1253          */
1254         list_for_each_entry(policy, &net->xfrm.policy_all, walk.all) {
1255                 struct xfrm_pol_inexact_bin *bin;
1256                 u8 dbits, sbits;
1257
1258                 dir = xfrm_policy_id2dir(policy->index);
1259                 if (policy->walk.dead || dir >= XFRM_POLICY_MAX)
1260                         continue;
1261
1262                 if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
1263                         if (policy->family == AF_INET) {
1264                                 dbits = rbits4;
1265                                 sbits = lbits4;
1266                         } else {
1267                                 dbits = rbits6;
1268                                 sbits = lbits6;
1269                         }
1270                 } else {
1271                         if (policy->family == AF_INET) {
1272                                 dbits = lbits4;
1273                                 sbits = rbits4;
1274                         } else {
1275                                 dbits = lbits6;
1276                                 sbits = rbits6;
1277                         }
1278                 }
1279
1280                 if (policy->selector.prefixlen_d < dbits ||
1281                     policy->selector.prefixlen_s < sbits)
1282                         continue;
1283
1284                 bin = xfrm_policy_inexact_alloc_bin(policy, dir);
1285                 if (!bin)
1286                         goto out_unlock;
1287
1288                 if (!xfrm_policy_inexact_alloc_chain(bin, policy, dir))
1289                         goto out_unlock;
1290         }
1291
1292         /* reset the bydst and inexact table in all directions */
1293         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
1294                 struct hlist_node *n;
1295
1296                 hlist_for_each_entry_safe(policy, n,
1297                                           &net->xfrm.policy_inexact[dir],
1298                                           bydst_inexact_list) {
1299                         hlist_del_rcu(&policy->bydst);
1300                         hlist_del_init(&policy->bydst_inexact_list);
1301                 }
1302
1303                 hmask = net->xfrm.policy_bydst[dir].hmask;
1304                 odst = net->xfrm.policy_bydst[dir].table;
1305                 for (i = hmask; i >= 0; i--) {
1306                         hlist_for_each_entry_safe(policy, n, odst + i, bydst)
1307                                 hlist_del_rcu(&policy->bydst);
1308                 }
1309                 if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
1310                         /* dir out => dst = remote, src = local */
1311                         net->xfrm.policy_bydst[dir].dbits4 = rbits4;
1312                         net->xfrm.policy_bydst[dir].sbits4 = lbits4;
1313                         net->xfrm.policy_bydst[dir].dbits6 = rbits6;
1314                         net->xfrm.policy_bydst[dir].sbits6 = lbits6;
1315                 } else {
1316                         /* dir in/fwd => dst = local, src = remote */
1317                         net->xfrm.policy_bydst[dir].dbits4 = lbits4;
1318                         net->xfrm.policy_bydst[dir].sbits4 = rbits4;
1319                         net->xfrm.policy_bydst[dir].dbits6 = lbits6;
1320                         net->xfrm.policy_bydst[dir].sbits6 = rbits6;
1321                 }
1322         }
1323
1324         /* re-insert all policies by order of creation */
1325         list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
1326                 if (policy->walk.dead)
1327                         continue;
1328                 dir = xfrm_policy_id2dir(policy->index);
1329                 if (dir >= XFRM_POLICY_MAX) {
1330                         /* skip socket policies */
1331                         continue;
1332                 }
1333                 newpos = NULL;
1334                 chain = policy_hash_bysel(net, &policy->selector,
1335                                           policy->family, dir);
1336
1337                 if (!chain) {
1338                         void *p = xfrm_policy_inexact_insert(policy, dir, 0);
1339
1340                         WARN_ONCE(IS_ERR(p), "reinsert: %ld\n", PTR_ERR(p));
1341                         continue;
1342                 }
1343
1344                 hlist_for_each_entry(pol, chain, bydst) {
1345                         if (policy->priority >= pol->priority)
1346                                 newpos = &pol->bydst;
1347                         else
1348                                 break;
1349                 }
1350                 if (newpos)
1351                         hlist_add_behind_rcu(&policy->bydst, newpos);
1352                 else
1353                         hlist_add_head_rcu(&policy->bydst, chain);
1354         }
1355
1356 out_unlock:
1357         __xfrm_policy_inexact_flush(net);
1358         write_seqcount_end(&net->xfrm.xfrm_policy_hash_generation);
1359         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1360
1361         mutex_unlock(&hash_resize_mutex);
1362 }
1363
1364 void xfrm_policy_hash_rebuild(struct net *net)
1365 {
1366         schedule_work(&net->xfrm.policy_hthresh.work);
1367 }
1368 EXPORT_SYMBOL(xfrm_policy_hash_rebuild);
1369
1370 /* Generate new index... KAME seems to generate them ordered by cost
1371  * of an absolute inpredictability of ordering of rules. This will not pass. */
1372 static u32 xfrm_gen_index(struct net *net, int dir, u32 index)
1373 {
1374         static u32 idx_generator;
1375
1376         for (;;) {
1377                 struct hlist_head *list;
1378                 struct xfrm_policy *p;
1379                 u32 idx;
1380                 int found;
1381
1382                 if (!index) {
1383                         idx = (idx_generator | dir);
1384                         idx_generator += 8;
1385                 } else {
1386                         idx = index;
1387                         index = 0;
1388                 }
1389
1390                 if (idx == 0)
1391                         idx = 8;
1392                 list = net->xfrm.policy_byidx + idx_hash(net, idx);
1393                 found = 0;
1394                 hlist_for_each_entry(p, list, byidx) {
1395                         if (p->index == idx) {
1396                                 found = 1;
1397                                 break;
1398                         }
1399                 }
1400                 if (!found)
1401                         return idx;
1402         }
1403 }
1404
1405 static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
1406 {
1407         u32 *p1 = (u32 *) s1;
1408         u32 *p2 = (u32 *) s2;
1409         int len = sizeof(struct xfrm_selector) / sizeof(u32);
1410         int i;
1411
1412         for (i = 0; i < len; i++) {
1413                 if (p1[i] != p2[i])
1414                         return 1;
1415         }
1416
1417         return 0;
1418 }
1419
1420 static void xfrm_policy_requeue(struct xfrm_policy *old,
1421                                 struct xfrm_policy *new)
1422 {
1423         struct xfrm_policy_queue *pq = &old->polq;
1424         struct sk_buff_head list;
1425
1426         if (skb_queue_empty(&pq->hold_queue))
1427                 return;
1428
1429         __skb_queue_head_init(&list);
1430
1431         spin_lock_bh(&pq->hold_queue.lock);
1432         skb_queue_splice_init(&pq->hold_queue, &list);
1433         if (del_timer(&pq->hold_timer))
1434                 xfrm_pol_put(old);
1435         spin_unlock_bh(&pq->hold_queue.lock);
1436
1437         pq = &new->polq;
1438
1439         spin_lock_bh(&pq->hold_queue.lock);
1440         skb_queue_splice(&list, &pq->hold_queue);
1441         pq->timeout = XFRM_QUEUE_TMO_MIN;
1442         if (!mod_timer(&pq->hold_timer, jiffies))
1443                 xfrm_pol_hold(new);
1444         spin_unlock_bh(&pq->hold_queue.lock);
1445 }
1446
1447 static inline bool xfrm_policy_mark_match(const struct xfrm_mark *mark,
1448                                           struct xfrm_policy *pol)
1449 {
1450         return mark->v == pol->mark.v && mark->m == pol->mark.m;
1451 }
1452
1453 static u32 xfrm_pol_bin_key(const void *data, u32 len, u32 seed)
1454 {
1455         const struct xfrm_pol_inexact_key *k = data;
1456         u32 a = k->type << 24 | k->dir << 16 | k->family;
1457
1458         return jhash_3words(a, k->if_id, net_hash_mix(read_pnet(&k->net)),
1459                             seed);
1460 }
1461
1462 static u32 xfrm_pol_bin_obj(const void *data, u32 len, u32 seed)
1463 {
1464         const struct xfrm_pol_inexact_bin *b = data;
1465
1466         return xfrm_pol_bin_key(&b->k, 0, seed);
1467 }
1468
1469 static int xfrm_pol_bin_cmp(struct rhashtable_compare_arg *arg,
1470                             const void *ptr)
1471 {
1472         const struct xfrm_pol_inexact_key *key = arg->key;
1473         const struct xfrm_pol_inexact_bin *b = ptr;
1474         int ret;
1475
1476         if (!net_eq(read_pnet(&b->k.net), read_pnet(&key->net)))
1477                 return -1;
1478
1479         ret = b->k.dir ^ key->dir;
1480         if (ret)
1481                 return ret;
1482
1483         ret = b->k.type ^ key->type;
1484         if (ret)
1485                 return ret;
1486
1487         ret = b->k.family ^ key->family;
1488         if (ret)
1489                 return ret;
1490
1491         return b->k.if_id ^ key->if_id;
1492 }
1493
1494 static const struct rhashtable_params xfrm_pol_inexact_params = {
1495         .head_offset            = offsetof(struct xfrm_pol_inexact_bin, head),
1496         .hashfn                 = xfrm_pol_bin_key,
1497         .obj_hashfn             = xfrm_pol_bin_obj,
1498         .obj_cmpfn              = xfrm_pol_bin_cmp,
1499         .automatic_shrinking    = true,
1500 };
1501
1502 static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
1503                                             struct xfrm_policy *policy)
1504 {
1505         struct xfrm_policy *pol, *delpol = NULL;
1506         struct hlist_node *newpos = NULL;
1507         int i = 0;
1508
1509         hlist_for_each_entry(pol, chain, bydst_inexact_list) {
1510                 if (pol->type == policy->type &&
1511                     pol->if_id == policy->if_id &&
1512                     !selector_cmp(&pol->selector, &policy->selector) &&
1513                     xfrm_policy_mark_match(&policy->mark, pol) &&
1514                     xfrm_sec_ctx_match(pol->security, policy->security) &&
1515                     !WARN_ON(delpol)) {
1516                         delpol = pol;
1517                         if (policy->priority > pol->priority)
1518                                 continue;
1519                 } else if (policy->priority >= pol->priority) {
1520                         newpos = &pol->bydst_inexact_list;
1521                         continue;
1522                 }
1523                 if (delpol)
1524                         break;
1525         }
1526
1527         if (newpos)
1528                 hlist_add_behind_rcu(&policy->bydst_inexact_list, newpos);
1529         else
1530                 hlist_add_head_rcu(&policy->bydst_inexact_list, chain);
1531
1532         hlist_for_each_entry(pol, chain, bydst_inexact_list) {
1533                 pol->pos = i;
1534                 i++;
1535         }
1536 }
1537
1538 static struct xfrm_policy *xfrm_policy_insert_list(struct hlist_head *chain,
1539                                                    struct xfrm_policy *policy,
1540                                                    bool excl)
1541 {
1542         struct xfrm_policy *pol, *newpos = NULL, *delpol = NULL;
1543
1544         hlist_for_each_entry(pol, chain, bydst) {
1545                 if (pol->type == policy->type &&
1546                     pol->if_id == policy->if_id &&
1547                     !selector_cmp(&pol->selector, &policy->selector) &&
1548                     xfrm_policy_mark_match(&policy->mark, pol) &&
1549                     xfrm_sec_ctx_match(pol->security, policy->security) &&
1550                     !WARN_ON(delpol)) {
1551                         if (excl)
1552                                 return ERR_PTR(-EEXIST);
1553                         delpol = pol;
1554                         if (policy->priority > pol->priority)
1555                                 continue;
1556                 } else if (policy->priority >= pol->priority) {
1557                         newpos = pol;
1558                         continue;
1559                 }
1560                 if (delpol)
1561                         break;
1562         }
1563
1564         if (newpos)
1565                 hlist_add_behind_rcu(&policy->bydst, &newpos->bydst);
1566         else
1567                 hlist_add_head_rcu(&policy->bydst, chain);
1568
1569         return delpol;
1570 }
1571
1572 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
1573 {
1574         struct net *net = xp_net(policy);
1575         struct xfrm_policy *delpol;
1576         struct hlist_head *chain;
1577
1578         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1579         chain = policy_hash_bysel(net, &policy->selector, policy->family, dir);
1580         if (chain)
1581                 delpol = xfrm_policy_insert_list(chain, policy, excl);
1582         else
1583                 delpol = xfrm_policy_inexact_insert(policy, dir, excl);
1584
1585         if (IS_ERR(delpol)) {
1586                 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1587                 return PTR_ERR(delpol);
1588         }
1589
1590         __xfrm_policy_link(policy, dir);
1591
1592         /* After previous checking, family can either be AF_INET or AF_INET6 */
1593         if (policy->family == AF_INET)
1594                 rt_genid_bump_ipv4(net);
1595         else
1596                 rt_genid_bump_ipv6(net);
1597
1598         if (delpol) {
1599                 xfrm_policy_requeue(delpol, policy);
1600                 __xfrm_policy_unlink(delpol, dir);
1601         }
1602         policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir, policy->index);
1603         hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
1604         policy->curlft.add_time = ktime_get_real_seconds();
1605         policy->curlft.use_time = 0;
1606         if (!mod_timer(&policy->timer, jiffies + HZ))
1607                 xfrm_pol_hold(policy);
1608         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1609
1610         if (delpol)
1611                 xfrm_policy_kill(delpol);
1612         else if (xfrm_bydst_should_resize(net, dir, NULL))
1613                 schedule_work(&net->xfrm.policy_hash_work);
1614
1615         return 0;
1616 }
1617 EXPORT_SYMBOL(xfrm_policy_insert);
1618
1619 static struct xfrm_policy *
1620 __xfrm_policy_bysel_ctx(struct hlist_head *chain, const struct xfrm_mark *mark,
1621                         u32 if_id, u8 type, int dir, struct xfrm_selector *sel,
1622                         struct xfrm_sec_ctx *ctx)
1623 {
1624         struct xfrm_policy *pol;
1625
1626         if (!chain)
1627                 return NULL;
1628
1629         hlist_for_each_entry(pol, chain, bydst) {
1630                 if (pol->type == type &&
1631                     pol->if_id == if_id &&
1632                     xfrm_policy_mark_match(mark, pol) &&
1633                     !selector_cmp(sel, &pol->selector) &&
1634                     xfrm_sec_ctx_match(ctx, pol->security))
1635                         return pol;
1636         }
1637
1638         return NULL;
1639 }
1640
1641 struct xfrm_policy *
1642 xfrm_policy_bysel_ctx(struct net *net, const struct xfrm_mark *mark, u32 if_id,
1643                       u8 type, int dir, struct xfrm_selector *sel,
1644                       struct xfrm_sec_ctx *ctx, int delete, int *err)
1645 {
1646         struct xfrm_pol_inexact_bin *bin = NULL;
1647         struct xfrm_policy *pol, *ret = NULL;
1648         struct hlist_head *chain;
1649
1650         *err = 0;
1651         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1652         chain = policy_hash_bysel(net, sel, sel->family, dir);
1653         if (!chain) {
1654                 struct xfrm_pol_inexact_candidates cand;
1655                 int i;
1656
1657                 bin = xfrm_policy_inexact_lookup(net, type,
1658                                                  sel->family, dir, if_id);
1659                 if (!bin) {
1660                         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1661                         return NULL;
1662                 }
1663
1664                 if (!xfrm_policy_find_inexact_candidates(&cand, bin,
1665                                                          &sel->saddr,
1666                                                          &sel->daddr)) {
1667                         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1668                         return NULL;
1669                 }
1670
1671                 pol = NULL;
1672                 for (i = 0; i < ARRAY_SIZE(cand.res); i++) {
1673                         struct xfrm_policy *tmp;
1674
1675                         tmp = __xfrm_policy_bysel_ctx(cand.res[i], mark,
1676                                                       if_id, type, dir,
1677                                                       sel, ctx);
1678                         if (!tmp)
1679                                 continue;
1680
1681                         if (!pol || tmp->pos < pol->pos)
1682                                 pol = tmp;
1683                 }
1684         } else {
1685                 pol = __xfrm_policy_bysel_ctx(chain, mark, if_id, type, dir,
1686                                               sel, ctx);
1687         }
1688
1689         if (pol) {
1690                 xfrm_pol_hold(pol);
1691                 if (delete) {
1692                         *err = security_xfrm_policy_delete(pol->security);
1693                         if (*err) {
1694                                 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1695                                 return pol;
1696                         }
1697                         __xfrm_policy_unlink(pol, dir);
1698                 }
1699                 ret = pol;
1700         }
1701         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1702
1703         if (ret && delete)
1704                 xfrm_policy_kill(ret);
1705         if (bin && delete)
1706                 xfrm_policy_inexact_prune_bin(bin);
1707         return ret;
1708 }
1709 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
1710
1711 struct xfrm_policy *
1712 xfrm_policy_byid(struct net *net, const struct xfrm_mark *mark, u32 if_id,
1713                  u8 type, int dir, u32 id, int delete, int *err)
1714 {
1715         struct xfrm_policy *pol, *ret;
1716         struct hlist_head *chain;
1717
1718         *err = -ENOENT;
1719         if (xfrm_policy_id2dir(id) != dir)
1720                 return NULL;
1721
1722         *err = 0;
1723         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1724         chain = net->xfrm.policy_byidx + idx_hash(net, id);
1725         ret = NULL;
1726         hlist_for_each_entry(pol, chain, byidx) {
1727                 if (pol->type == type && pol->index == id &&
1728                     pol->if_id == if_id && xfrm_policy_mark_match(mark, pol)) {
1729                         xfrm_pol_hold(pol);
1730                         if (delete) {
1731                                 *err = security_xfrm_policy_delete(
1732                                                                 pol->security);
1733                                 if (*err) {
1734                                         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1735                                         return pol;
1736                                 }
1737                                 __xfrm_policy_unlink(pol, dir);
1738                         }
1739                         ret = pol;
1740                         break;
1741                 }
1742         }
1743         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1744
1745         if (ret && delete)
1746                 xfrm_policy_kill(ret);
1747         return ret;
1748 }
1749 EXPORT_SYMBOL(xfrm_policy_byid);
1750
1751 #ifdef CONFIG_SECURITY_NETWORK_XFRM
1752 static inline int
1753 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
1754 {
1755         struct xfrm_policy *pol;
1756         int err = 0;
1757
1758         list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
1759                 if (pol->walk.dead ||
1760                     xfrm_policy_id2dir(pol->index) >= XFRM_POLICY_MAX ||
1761                     pol->type != type)
1762                         continue;
1763
1764                 err = security_xfrm_policy_delete(pol->security);
1765                 if (err) {
1766                         xfrm_audit_policy_delete(pol, 0, task_valid);
1767                         return err;
1768                 }
1769         }
1770         return err;
1771 }
1772 #else
1773 static inline int
1774 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
1775 {
1776         return 0;
1777 }
1778 #endif
1779
1780 int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
1781 {
1782         int dir, err = 0, cnt = 0;
1783         struct xfrm_policy *pol;
1784
1785         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1786
1787         err = xfrm_policy_flush_secctx_check(net, type, task_valid);
1788         if (err)
1789                 goto out;
1790
1791 again:
1792         list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
1793                 dir = xfrm_policy_id2dir(pol->index);
1794                 if (pol->walk.dead ||
1795                     dir >= XFRM_POLICY_MAX ||
1796                     pol->type != type)
1797                         continue;
1798
1799                 __xfrm_policy_unlink(pol, dir);
1800                 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1801                 cnt++;
1802                 xfrm_audit_policy_delete(pol, 1, task_valid);
1803                 xfrm_policy_kill(pol);
1804                 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1805                 goto again;
1806         }
1807         if (cnt)
1808                 __xfrm_policy_inexact_flush(net);
1809         else
1810                 err = -ESRCH;
1811 out:
1812         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1813         return err;
1814 }
1815 EXPORT_SYMBOL(xfrm_policy_flush);
1816
1817 int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
1818                      int (*func)(struct xfrm_policy *, int, int, void*),
1819                      void *data)
1820 {
1821         struct xfrm_policy *pol;
1822         struct xfrm_policy_walk_entry *x;
1823         int error = 0;
1824
1825         if (walk->type >= XFRM_POLICY_TYPE_MAX &&
1826             walk->type != XFRM_POLICY_TYPE_ANY)
1827                 return -EINVAL;
1828
1829         if (list_empty(&walk->walk.all) && walk->seq != 0)
1830                 return 0;
1831
1832         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
1833         if (list_empty(&walk->walk.all))
1834                 x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
1835         else
1836                 x = list_first_entry(&walk->walk.all,
1837                                      struct xfrm_policy_walk_entry, all);
1838
1839         list_for_each_entry_from(x, &net->xfrm.policy_all, all) {
1840                 if (x->dead)
1841                         continue;
1842                 pol = container_of(x, struct xfrm_policy, walk);
1843                 if (walk->type != XFRM_POLICY_TYPE_ANY &&
1844                     walk->type != pol->type)
1845                         continue;
1846                 error = func(pol, xfrm_policy_id2dir(pol->index),
1847                              walk->seq, data);
1848                 if (error) {
1849                         list_move_tail(&walk->walk.all, &x->all);
1850                         goto out;
1851                 }
1852                 walk->seq++;
1853         }
1854         if (walk->seq == 0) {
1855                 error = -ENOENT;
1856                 goto out;
1857         }
1858         list_del_init(&walk->walk.all);
1859 out:
1860         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1861         return error;
1862 }
1863 EXPORT_SYMBOL(xfrm_policy_walk);
1864
1865 void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type)
1866 {
1867         INIT_LIST_HEAD(&walk->walk.all);
1868         walk->walk.dead = 1;
1869         walk->type = type;
1870         walk->seq = 0;
1871 }
1872 EXPORT_SYMBOL(xfrm_policy_walk_init);
1873
1874 void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net)
1875 {
1876         if (list_empty(&walk->walk.all))
1877                 return;
1878
1879         spin_lock_bh(&net->xfrm.xfrm_policy_lock); /*FIXME where is net? */
1880         list_del(&walk->walk.all);
1881         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
1882 }
1883 EXPORT_SYMBOL(xfrm_policy_walk_done);
1884
1885 /*
1886  * Find policy to apply to this flow.
1887  *
1888  * Returns 0 if policy found, else an -errno.
1889  */
1890 static int xfrm_policy_match(const struct xfrm_policy *pol,
1891                              const struct flowi *fl,
1892                              u8 type, u16 family, int dir, u32 if_id)
1893 {
1894         const struct xfrm_selector *sel = &pol->selector;
1895         int ret = -ESRCH;
1896         bool match;
1897
1898         if (pol->family != family ||
1899             pol->if_id != if_id ||
1900             (fl->flowi_mark & pol->mark.m) != pol->mark.v ||
1901             pol->type != type)
1902                 return ret;
1903
1904         match = xfrm_selector_match(sel, fl, family);
1905         if (match)
1906                 ret = security_xfrm_policy_lookup(pol->security, fl->flowi_secid);
1907         return ret;
1908 }
1909
1910 static struct xfrm_pol_inexact_node *
1911 xfrm_policy_lookup_inexact_addr(const struct rb_root *r,
1912                                 seqcount_spinlock_t *count,
1913                                 const xfrm_address_t *addr, u16 family)
1914 {
1915         const struct rb_node *parent;
1916         int seq;
1917
1918 again:
1919         seq = read_seqcount_begin(count);
1920
1921         parent = rcu_dereference_raw(r->rb_node);
1922         while (parent) {
1923                 struct xfrm_pol_inexact_node *node;
1924                 int delta;
1925
1926                 node = rb_entry(parent, struct xfrm_pol_inexact_node, node);
1927
1928                 delta = xfrm_policy_addr_delta(addr, &node->addr,
1929                                                node->prefixlen, family);
1930                 if (delta < 0) {
1931                         parent = rcu_dereference_raw(parent->rb_left);
1932                         continue;
1933                 } else if (delta > 0) {
1934                         parent = rcu_dereference_raw(parent->rb_right);
1935                         continue;
1936                 }
1937
1938                 return node;
1939         }
1940
1941         if (read_seqcount_retry(count, seq))
1942                 goto again;
1943
1944         return NULL;
1945 }
1946
1947 static bool
1948 xfrm_policy_find_inexact_candidates(struct xfrm_pol_inexact_candidates *cand,
1949                                     struct xfrm_pol_inexact_bin *b,
1950                                     const xfrm_address_t *saddr,
1951                                     const xfrm_address_t *daddr)
1952 {
1953         struct xfrm_pol_inexact_node *n;
1954         u16 family;
1955
1956         if (!b)
1957                 return false;
1958
1959         family = b->k.family;
1960         memset(cand, 0, sizeof(*cand));
1961         cand->res[XFRM_POL_CAND_ANY] = &b->hhead;
1962
1963         n = xfrm_policy_lookup_inexact_addr(&b->root_d, &b->count, daddr,
1964                                             family);
1965         if (n) {
1966                 cand->res[XFRM_POL_CAND_DADDR] = &n->hhead;
1967                 n = xfrm_policy_lookup_inexact_addr(&n->root, &b->count, saddr,
1968                                                     family);
1969                 if (n)
1970                         cand->res[XFRM_POL_CAND_BOTH] = &n->hhead;
1971         }
1972
1973         n = xfrm_policy_lookup_inexact_addr(&b->root_s, &b->count, saddr,
1974                                             family);
1975         if (n)
1976                 cand->res[XFRM_POL_CAND_SADDR] = &n->hhead;
1977
1978         return true;
1979 }
1980
1981 static struct xfrm_pol_inexact_bin *
1982 xfrm_policy_inexact_lookup_rcu(struct net *net, u8 type, u16 family,
1983                                u8 dir, u32 if_id)
1984 {
1985         struct xfrm_pol_inexact_key k = {
1986                 .family = family,
1987                 .type = type,
1988                 .dir = dir,
1989                 .if_id = if_id,
1990         };
1991
1992         write_pnet(&k.net, net);
1993
1994         return rhashtable_lookup(&xfrm_policy_inexact_table, &k,
1995                                  xfrm_pol_inexact_params);
1996 }
1997
1998 static struct xfrm_pol_inexact_bin *
1999 xfrm_policy_inexact_lookup(struct net *net, u8 type, u16 family,
2000                            u8 dir, u32 if_id)
2001 {
2002         struct xfrm_pol_inexact_bin *bin;
2003
2004         lockdep_assert_held(&net->xfrm.xfrm_policy_lock);
2005
2006         rcu_read_lock();
2007         bin = xfrm_policy_inexact_lookup_rcu(net, type, family, dir, if_id);
2008         rcu_read_unlock();
2009
2010         return bin;
2011 }
2012
2013 static struct xfrm_policy *
2014 __xfrm_policy_eval_candidates(struct hlist_head *chain,
2015                               struct xfrm_policy *prefer,
2016                               const struct flowi *fl,
2017                               u8 type, u16 family, int dir, u32 if_id)
2018 {
2019         u32 priority = prefer ? prefer->priority : ~0u;
2020         struct xfrm_policy *pol;
2021
2022         if (!chain)
2023                 return NULL;
2024
2025         hlist_for_each_entry_rcu(pol, chain, bydst) {
2026                 int err;
2027
2028                 if (pol->priority > priority)
2029                         break;
2030
2031                 err = xfrm_policy_match(pol, fl, type, family, dir, if_id);
2032                 if (err) {
2033                         if (err != -ESRCH)
2034                                 return ERR_PTR(err);
2035
2036                         continue;
2037                 }
2038
2039                 if (prefer) {
2040                         /* matches.  Is it older than *prefer? */
2041                         if (pol->priority == priority &&
2042                             prefer->pos < pol->pos)
2043                                 return prefer;
2044                 }
2045
2046                 return pol;
2047         }
2048
2049         return NULL;
2050 }
2051
2052 static struct xfrm_policy *
2053 xfrm_policy_eval_candidates(struct xfrm_pol_inexact_candidates *cand,
2054                             struct xfrm_policy *prefer,
2055                             const struct flowi *fl,
2056                             u8 type, u16 family, int dir, u32 if_id)
2057 {
2058         struct xfrm_policy *tmp;
2059         int i;
2060
2061         for (i = 0; i < ARRAY_SIZE(cand->res); i++) {
2062                 tmp = __xfrm_policy_eval_candidates(cand->res[i],
2063                                                     prefer,
2064                                                     fl, type, family, dir,
2065                                                     if_id);
2066                 if (!tmp)
2067                         continue;
2068
2069                 if (IS_ERR(tmp))
2070                         return tmp;
2071                 prefer = tmp;
2072         }
2073
2074         return prefer;
2075 }
2076
2077 static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
2078                                                      const struct flowi *fl,
2079                                                      u16 family, u8 dir,
2080                                                      u32 if_id)
2081 {
2082         struct xfrm_pol_inexact_candidates cand;
2083         const xfrm_address_t *daddr, *saddr;
2084         struct xfrm_pol_inexact_bin *bin;
2085         struct xfrm_policy *pol, *ret;
2086         struct hlist_head *chain;
2087         unsigned int sequence;
2088         int err;
2089
2090         daddr = xfrm_flowi_daddr(fl, family);
2091         saddr = xfrm_flowi_saddr(fl, family);
2092         if (unlikely(!daddr || !saddr))
2093                 return NULL;
2094
2095         rcu_read_lock();
2096  retry:
2097         do {
2098                 sequence = read_seqcount_begin(&net->xfrm.xfrm_policy_hash_generation);
2099                 chain = policy_hash_direct(net, daddr, saddr, family, dir);
2100         } while (read_seqcount_retry(&net->xfrm.xfrm_policy_hash_generation, sequence));
2101
2102         ret = NULL;
2103         hlist_for_each_entry_rcu(pol, chain, bydst) {
2104                 err = xfrm_policy_match(pol, fl, type, family, dir, if_id);
2105                 if (err) {
2106                         if (err == -ESRCH)
2107                                 continue;
2108                         else {
2109                                 ret = ERR_PTR(err);
2110                                 goto fail;
2111                         }
2112                 } else {
2113                         ret = pol;
2114                         break;
2115                 }
2116         }
2117         bin = xfrm_policy_inexact_lookup_rcu(net, type, family, dir, if_id);
2118         if (!bin || !xfrm_policy_find_inexact_candidates(&cand, bin, saddr,
2119                                                          daddr))
2120                 goto skip_inexact;
2121
2122         pol = xfrm_policy_eval_candidates(&cand, ret, fl, type,
2123                                           family, dir, if_id);
2124         if (pol) {
2125                 ret = pol;
2126                 if (IS_ERR(pol))
2127                         goto fail;
2128         }
2129
2130 skip_inexact:
2131         if (read_seqcount_retry(&net->xfrm.xfrm_policy_hash_generation, sequence))
2132                 goto retry;
2133
2134         if (ret && !xfrm_pol_hold_rcu(ret))
2135                 goto retry;
2136 fail:
2137         rcu_read_unlock();
2138
2139         return ret;
2140 }
2141
2142 static struct xfrm_policy *xfrm_policy_lookup(struct net *net,
2143                                               const struct flowi *fl,
2144                                               u16 family, u8 dir, u32 if_id)
2145 {
2146 #ifdef CONFIG_XFRM_SUB_POLICY
2147         struct xfrm_policy *pol;
2148
2149         pol = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_SUB, fl, family,
2150                                         dir, if_id);
2151         if (pol != NULL)
2152                 return pol;
2153 #endif
2154         return xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, fl, family,
2155                                          dir, if_id);
2156 }
2157
2158 static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir,
2159                                                  const struct flowi *fl,
2160                                                  u16 family, u32 if_id)
2161 {
2162         struct xfrm_policy *pol;
2163
2164         rcu_read_lock();
2165  again:
2166         pol = rcu_dereference(sk->sk_policy[dir]);
2167         if (pol != NULL) {
2168                 bool match;
2169                 int err = 0;
2170
2171                 if (pol->family != family) {
2172                         pol = NULL;
2173                         goto out;
2174                 }
2175
2176                 match = xfrm_selector_match(&pol->selector, fl, family);
2177                 if (match) {
2178                         if ((sk->sk_mark & pol->mark.m) != pol->mark.v ||
2179                             pol->if_id != if_id) {
2180                                 pol = NULL;
2181                                 goto out;
2182                         }
2183                         err = security_xfrm_policy_lookup(pol->security,
2184                                                       fl->flowi_secid);
2185                         if (!err) {
2186                                 if (!xfrm_pol_hold_rcu(pol))
2187                                         goto again;
2188                         } else if (err == -ESRCH) {
2189                                 pol = NULL;
2190                         } else {
2191                                 pol = ERR_PTR(err);
2192                         }
2193                 } else
2194                         pol = NULL;
2195         }
2196 out:
2197         rcu_read_unlock();
2198         return pol;
2199 }
2200
2201 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
2202 {
2203         struct net *net = xp_net(pol);
2204
2205         list_add(&pol->walk.all, &net->xfrm.policy_all);
2206         net->xfrm.policy_count[dir]++;
2207         xfrm_pol_hold(pol);
2208 }
2209
2210 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
2211                                                 int dir)
2212 {
2213         struct net *net = xp_net(pol);
2214
2215         if (list_empty(&pol->walk.all))
2216                 return NULL;
2217
2218         /* Socket policies are not hashed. */
2219         if (!hlist_unhashed(&pol->bydst)) {
2220                 hlist_del_rcu(&pol->bydst);
2221                 hlist_del_init(&pol->bydst_inexact_list);
2222                 hlist_del(&pol->byidx);
2223         }
2224
2225         list_del_init(&pol->walk.all);
2226         net->xfrm.policy_count[dir]--;
2227
2228         return pol;
2229 }
2230
2231 static void xfrm_sk_policy_link(struct xfrm_policy *pol, int dir)
2232 {
2233         __xfrm_policy_link(pol, XFRM_POLICY_MAX + dir);
2234 }
2235
2236 static void xfrm_sk_policy_unlink(struct xfrm_policy *pol, int dir)
2237 {
2238         __xfrm_policy_unlink(pol, XFRM_POLICY_MAX + dir);
2239 }
2240
2241 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
2242 {
2243         struct net *net = xp_net(pol);
2244
2245         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2246         pol = __xfrm_policy_unlink(pol, dir);
2247         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2248         if (pol) {
2249                 xfrm_policy_kill(pol);
2250                 return 0;
2251         }
2252         return -ENOENT;
2253 }
2254 EXPORT_SYMBOL(xfrm_policy_delete);
2255
2256 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
2257 {
2258         struct net *net = sock_net(sk);
2259         struct xfrm_policy *old_pol;
2260
2261 #ifdef CONFIG_XFRM_SUB_POLICY
2262         if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
2263                 return -EINVAL;
2264 #endif
2265
2266         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2267         old_pol = rcu_dereference_protected(sk->sk_policy[dir],
2268                                 lockdep_is_held(&net->xfrm.xfrm_policy_lock));
2269         if (pol) {
2270                 pol->curlft.add_time = ktime_get_real_seconds();
2271                 pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir, 0);
2272                 xfrm_sk_policy_link(pol, dir);
2273         }
2274         rcu_assign_pointer(sk->sk_policy[dir], pol);
2275         if (old_pol) {
2276                 if (pol)
2277                         xfrm_policy_requeue(old_pol, pol);
2278
2279                 /* Unlinking succeeds always. This is the only function
2280                  * allowed to delete or replace socket policy.
2281                  */
2282                 xfrm_sk_policy_unlink(old_pol, dir);
2283         }
2284         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2285
2286         if (old_pol) {
2287                 xfrm_policy_kill(old_pol);
2288         }
2289         return 0;
2290 }
2291
2292 static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
2293 {
2294         struct xfrm_policy *newp = xfrm_policy_alloc(xp_net(old), GFP_ATOMIC);
2295         struct net *net = xp_net(old);
2296
2297         if (newp) {
2298                 newp->selector = old->selector;
2299                 if (security_xfrm_policy_clone(old->security,
2300                                                &newp->security)) {
2301                         kfree(newp);
2302                         return NULL;  /* ENOMEM */
2303                 }
2304                 newp->lft = old->lft;
2305                 newp->curlft = old->curlft;
2306                 newp->mark = old->mark;
2307                 newp->if_id = old->if_id;
2308                 newp->action = old->action;
2309                 newp->flags = old->flags;
2310                 newp->xfrm_nr = old->xfrm_nr;
2311                 newp->index = old->index;
2312                 newp->type = old->type;
2313                 newp->family = old->family;
2314                 memcpy(newp->xfrm_vec, old->xfrm_vec,
2315                        newp->xfrm_nr*sizeof(struct xfrm_tmpl));
2316                 spin_lock_bh(&net->xfrm.xfrm_policy_lock);
2317                 xfrm_sk_policy_link(newp, dir);
2318                 spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
2319                 xfrm_pol_put(newp);
2320         }
2321         return newp;
2322 }
2323
2324 int __xfrm_sk_clone_policy(struct sock *sk, const struct sock *osk)
2325 {
2326         const struct xfrm_policy *p;
2327         struct xfrm_policy *np;
2328         int i, ret = 0;
2329
2330         rcu_read_lock();
2331         for (i = 0; i < 2; i++) {
2332                 p = rcu_dereference(osk->sk_policy[i]);
2333                 if (p) {
2334                         np = clone_policy(p, i);
2335                         if (unlikely(!np)) {
2336                                 ret = -ENOMEM;
2337                                 break;
2338                         }
2339                         rcu_assign_pointer(sk->sk_policy[i], np);
2340                 }
2341         }
2342         rcu_read_unlock();
2343         return ret;
2344 }
2345
2346 static int
2347 xfrm_get_saddr(struct net *net, int oif, xfrm_address_t *local,
2348                xfrm_address_t *remote, unsigned short family, u32 mark)
2349 {
2350         int err;
2351         const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2352
2353         if (unlikely(afinfo == NULL))
2354                 return -EINVAL;
2355         err = afinfo->get_saddr(net, oif, local, remote, mark);
2356         rcu_read_unlock();
2357         return err;
2358 }
2359
2360 /* Resolve list of templates for the flow, given policy. */
2361
2362 static int
2363 xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
2364                       struct xfrm_state **xfrm, unsigned short family)
2365 {
2366         struct net *net = xp_net(policy);
2367         int nx;
2368         int i, error;
2369         xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
2370         xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
2371         xfrm_address_t tmp;
2372
2373         for (nx = 0, i = 0; i < policy->xfrm_nr; i++) {
2374                 struct xfrm_state *x;
2375                 xfrm_address_t *remote = daddr;
2376                 xfrm_address_t *local  = saddr;
2377                 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
2378
2379                 if (tmpl->mode == XFRM_MODE_TUNNEL ||
2380                     tmpl->mode == XFRM_MODE_BEET) {
2381                         remote = &tmpl->id.daddr;
2382                         local = &tmpl->saddr;
2383                         if (xfrm_addr_any(local, tmpl->encap_family)) {
2384                                 error = xfrm_get_saddr(net, fl->flowi_oif,
2385                                                        &tmp, remote,
2386                                                        tmpl->encap_family, 0);
2387                                 if (error)
2388                                         goto fail;
2389                                 local = &tmp;
2390                         }
2391                 }
2392
2393                 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error,
2394                                     family, policy->if_id);
2395
2396                 if (x && x->km.state == XFRM_STATE_VALID) {
2397                         xfrm[nx++] = x;
2398                         daddr = remote;
2399                         saddr = local;
2400                         continue;
2401                 }
2402                 if (x) {
2403                         error = (x->km.state == XFRM_STATE_ERROR ?
2404                                  -EINVAL : -EAGAIN);
2405                         xfrm_state_put(x);
2406                 } else if (error == -ESRCH) {
2407                         error = -EAGAIN;
2408                 }
2409
2410                 if (!tmpl->optional)
2411                         goto fail;
2412         }
2413         return nx;
2414
2415 fail:
2416         for (nx--; nx >= 0; nx--)
2417                 xfrm_state_put(xfrm[nx]);
2418         return error;
2419 }
2420
2421 static int
2422 xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, const struct flowi *fl,
2423                   struct xfrm_state **xfrm, unsigned short family)
2424 {
2425         struct xfrm_state *tp[XFRM_MAX_DEPTH];
2426         struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
2427         int cnx = 0;
2428         int error;
2429         int ret;
2430         int i;
2431
2432         for (i = 0; i < npols; i++) {
2433                 if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
2434                         error = -ENOBUFS;
2435                         goto fail;
2436                 }
2437
2438                 ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
2439                 if (ret < 0) {
2440                         error = ret;
2441                         goto fail;
2442                 } else
2443                         cnx += ret;
2444         }
2445
2446         /* found states are sorted for outbound processing */
2447         if (npols > 1)
2448                 xfrm_state_sort(xfrm, tpp, cnx, family);
2449
2450         return cnx;
2451
2452  fail:
2453         for (cnx--; cnx >= 0; cnx--)
2454                 xfrm_state_put(tpp[cnx]);
2455         return error;
2456
2457 }
2458
2459 static int xfrm_get_tos(const struct flowi *fl, int family)
2460 {
2461         if (family == AF_INET)
2462                 return IPTOS_RT_MASK & fl->u.ip4.flowi4_tos;
2463
2464         return 0;
2465 }
2466
2467 static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
2468 {
2469         const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2470         struct dst_ops *dst_ops;
2471         struct xfrm_dst *xdst;
2472
2473         if (!afinfo)
2474                 return ERR_PTR(-EINVAL);
2475
2476         switch (family) {
2477         case AF_INET:
2478                 dst_ops = &net->xfrm.xfrm4_dst_ops;
2479                 break;
2480 #if IS_ENABLED(CONFIG_IPV6)
2481         case AF_INET6:
2482                 dst_ops = &net->xfrm.xfrm6_dst_ops;
2483                 break;
2484 #endif
2485         default:
2486                 BUG();
2487         }
2488         xdst = dst_alloc(dst_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2489
2490         if (likely(xdst)) {
2491                 memset_after(xdst, 0, u.dst);
2492         } else
2493                 xdst = ERR_PTR(-ENOBUFS);
2494
2495         rcu_read_unlock();
2496
2497         return xdst;
2498 }
2499
2500 static void xfrm_init_path(struct xfrm_dst *path, struct dst_entry *dst,
2501                            int nfheader_len)
2502 {
2503         if (dst->ops->family == AF_INET6) {
2504                 struct rt6_info *rt = (struct rt6_info *)dst;
2505                 path->path_cookie = rt6_get_cookie(rt);
2506                 path->u.rt6.rt6i_nfheader_len = nfheader_len;
2507         }
2508 }
2509
2510 static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
2511                                 const struct flowi *fl)
2512 {
2513         const struct xfrm_policy_afinfo *afinfo =
2514                 xfrm_policy_get_afinfo(xdst->u.dst.ops->family);
2515         int err;
2516
2517         if (!afinfo)
2518                 return -EINVAL;
2519
2520         err = afinfo->fill_dst(xdst, dev, fl);
2521
2522         rcu_read_unlock();
2523
2524         return err;
2525 }
2526
2527
2528 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
2529  * all the metrics... Shortly, bundle a bundle.
2530  */
2531
2532 static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
2533                                             struct xfrm_state **xfrm,
2534                                             struct xfrm_dst **bundle,
2535                                             int nx,
2536                                             const struct flowi *fl,
2537                                             struct dst_entry *dst)
2538 {
2539         const struct xfrm_state_afinfo *afinfo;
2540         const struct xfrm_mode *inner_mode;
2541         struct net *net = xp_net(policy);
2542         unsigned long now = jiffies;
2543         struct net_device *dev;
2544         struct xfrm_dst *xdst_prev = NULL;
2545         struct xfrm_dst *xdst0 = NULL;
2546         int i = 0;
2547         int err;
2548         int header_len = 0;
2549         int nfheader_len = 0;
2550         int trailer_len = 0;
2551         int tos;
2552         int family = policy->selector.family;
2553         xfrm_address_t saddr, daddr;
2554
2555         xfrm_flowi_addr_get(fl, &saddr, &daddr, family);
2556
2557         tos = xfrm_get_tos(fl, family);
2558
2559         dst_hold(dst);
2560
2561         for (; i < nx; i++) {
2562                 struct xfrm_dst *xdst = xfrm_alloc_dst(net, family);
2563                 struct dst_entry *dst1 = &xdst->u.dst;
2564
2565                 err = PTR_ERR(xdst);
2566                 if (IS_ERR(xdst)) {
2567                         dst_release(dst);
2568                         goto put_states;
2569                 }
2570
2571                 bundle[i] = xdst;
2572                 if (!xdst_prev)
2573                         xdst0 = xdst;
2574                 else
2575                         /* Ref count is taken during xfrm_alloc_dst()
2576                          * No need to do dst_clone() on dst1
2577                          */
2578                         xfrm_dst_set_child(xdst_prev, &xdst->u.dst);
2579
2580                 if (xfrm[i]->sel.family == AF_UNSPEC) {
2581                         inner_mode = xfrm_ip2inner_mode(xfrm[i],
2582                                                         xfrm_af2proto(family));
2583                         if (!inner_mode) {
2584                                 err = -EAFNOSUPPORT;
2585                                 dst_release(dst);
2586                                 goto put_states;
2587                         }
2588                 } else
2589                         inner_mode = &xfrm[i]->inner_mode;
2590
2591                 xdst->route = dst;
2592                 dst_copy_metrics(dst1, dst);
2593
2594                 if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
2595                         __u32 mark = 0;
2596                         int oif;
2597
2598                         if (xfrm[i]->props.smark.v || xfrm[i]->props.smark.m)
2599                                 mark = xfrm_smark_get(fl->flowi_mark, xfrm[i]);
2600
2601                         family = xfrm[i]->props.family;
2602                         oif = fl->flowi_oif ? : fl->flowi_l3mdev;
2603                         dst = xfrm_dst_lookup(xfrm[i], tos, oif,
2604                                               &saddr, &daddr, family, mark);
2605                         err = PTR_ERR(dst);
2606                         if (IS_ERR(dst))
2607                                 goto put_states;
2608                 } else
2609                         dst_hold(dst);
2610
2611                 dst1->xfrm = xfrm[i];
2612                 xdst->xfrm_genid = xfrm[i]->genid;
2613
2614                 dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
2615                 dst1->lastuse = now;
2616
2617                 dst1->input = dst_discard;
2618
2619                 rcu_read_lock();
2620                 afinfo = xfrm_state_afinfo_get_rcu(inner_mode->family);
2621                 if (likely(afinfo))
2622                         dst1->output = afinfo->output;
2623                 else
2624                         dst1->output = dst_discard_out;
2625                 rcu_read_unlock();
2626
2627                 xdst_prev = xdst;
2628
2629                 header_len += xfrm[i]->props.header_len;
2630                 if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
2631                         nfheader_len += xfrm[i]->props.header_len;
2632                 trailer_len += xfrm[i]->props.trailer_len;
2633         }
2634
2635         xfrm_dst_set_child(xdst_prev, dst);
2636         xdst0->path = dst;
2637
2638         err = -ENODEV;
2639         dev = dst->dev;
2640         if (!dev)
2641                 goto free_dst;
2642
2643         xfrm_init_path(xdst0, dst, nfheader_len);
2644         xfrm_init_pmtu(bundle, nx);
2645
2646         for (xdst_prev = xdst0; xdst_prev != (struct xfrm_dst *)dst;
2647              xdst_prev = (struct xfrm_dst *) xfrm_dst_child(&xdst_prev->u.dst)) {
2648                 err = xfrm_fill_dst(xdst_prev, dev, fl);
2649                 if (err)
2650                         goto free_dst;
2651
2652                 xdst_prev->u.dst.header_len = header_len;
2653                 xdst_prev->u.dst.trailer_len = trailer_len;
2654                 header_len -= xdst_prev->u.dst.xfrm->props.header_len;
2655                 trailer_len -= xdst_prev->u.dst.xfrm->props.trailer_len;
2656         }
2657
2658         return &xdst0->u.dst;
2659
2660 put_states:
2661         for (; i < nx; i++)
2662                 xfrm_state_put(xfrm[i]);
2663 free_dst:
2664         if (xdst0)
2665                 dst_release_immediate(&xdst0->u.dst);
2666
2667         return ERR_PTR(err);
2668 }
2669
2670 static int xfrm_expand_policies(const struct flowi *fl, u16 family,
2671                                 struct xfrm_policy **pols,
2672                                 int *num_pols, int *num_xfrms)
2673 {
2674         int i;
2675
2676         if (*num_pols == 0 || !pols[0]) {
2677                 *num_pols = 0;
2678                 *num_xfrms = 0;
2679                 return 0;
2680         }
2681         if (IS_ERR(pols[0])) {
2682                 *num_pols = 0;
2683                 return PTR_ERR(pols[0]);
2684         }
2685
2686         *num_xfrms = pols[0]->xfrm_nr;
2687
2688 #ifdef CONFIG_XFRM_SUB_POLICY
2689         if (pols[0]->action == XFRM_POLICY_ALLOW &&
2690             pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
2691                 pols[1] = xfrm_policy_lookup_bytype(xp_net(pols[0]),
2692                                                     XFRM_POLICY_TYPE_MAIN,
2693                                                     fl, family,
2694                                                     XFRM_POLICY_OUT,
2695                                                     pols[0]->if_id);
2696                 if (pols[1]) {
2697                         if (IS_ERR(pols[1])) {
2698                                 xfrm_pols_put(pols, *num_pols);
2699                                 *num_pols = 0;
2700                                 return PTR_ERR(pols[1]);
2701                         }
2702                         (*num_pols)++;
2703                         (*num_xfrms) += pols[1]->xfrm_nr;
2704                 }
2705         }
2706 #endif
2707         for (i = 0; i < *num_pols; i++) {
2708                 if (pols[i]->action != XFRM_POLICY_ALLOW) {
2709                         *num_xfrms = -1;
2710                         break;
2711                 }
2712         }
2713
2714         return 0;
2715
2716 }
2717
2718 static struct xfrm_dst *
2719 xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
2720                                const struct flowi *fl, u16 family,
2721                                struct dst_entry *dst_orig)
2722 {
2723         struct net *net = xp_net(pols[0]);
2724         struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
2725         struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
2726         struct xfrm_dst *xdst;
2727         struct dst_entry *dst;
2728         int err;
2729
2730         /* Try to instantiate a bundle */
2731         err = xfrm_tmpl_resolve(pols, num_pols, fl, xfrm, family);
2732         if (err <= 0) {
2733                 if (err == 0)
2734                         return NULL;
2735
2736                 if (err != -EAGAIN)
2737                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
2738                 return ERR_PTR(err);
2739         }
2740
2741         dst = xfrm_bundle_create(pols[0], xfrm, bundle, err, fl, dst_orig);
2742         if (IS_ERR(dst)) {
2743                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR);
2744                 return ERR_CAST(dst);
2745         }
2746
2747         xdst = (struct xfrm_dst *)dst;
2748         xdst->num_xfrms = err;
2749         xdst->num_pols = num_pols;
2750         memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
2751         xdst->policy_genid = atomic_read(&pols[0]->genid);
2752
2753         return xdst;
2754 }
2755
2756 static void xfrm_policy_queue_process(struct timer_list *t)
2757 {
2758         struct sk_buff *skb;
2759         struct sock *sk;
2760         struct dst_entry *dst;
2761         struct xfrm_policy *pol = from_timer(pol, t, polq.hold_timer);
2762         struct net *net = xp_net(pol);
2763         struct xfrm_policy_queue *pq = &pol->polq;
2764         struct flowi fl;
2765         struct sk_buff_head list;
2766         __u32 skb_mark;
2767
2768         spin_lock(&pq->hold_queue.lock);
2769         skb = skb_peek(&pq->hold_queue);
2770         if (!skb) {
2771                 spin_unlock(&pq->hold_queue.lock);
2772                 goto out;
2773         }
2774         dst = skb_dst(skb);
2775         sk = skb->sk;
2776
2777         /* Fixup the mark to support VTI. */
2778         skb_mark = skb->mark;
2779         skb->mark = pol->mark.v;
2780         xfrm_decode_session(skb, &fl, dst->ops->family);
2781         skb->mark = skb_mark;
2782         spin_unlock(&pq->hold_queue.lock);
2783
2784         dst_hold(xfrm_dst_path(dst));
2785         dst = xfrm_lookup(net, xfrm_dst_path(dst), &fl, sk, XFRM_LOOKUP_QUEUE);
2786         if (IS_ERR(dst))
2787                 goto purge_queue;
2788
2789         if (dst->flags & DST_XFRM_QUEUE) {
2790                 dst_release(dst);
2791
2792                 if (pq->timeout >= XFRM_QUEUE_TMO_MAX)
2793                         goto purge_queue;
2794
2795                 pq->timeout = pq->timeout << 1;
2796                 if (!mod_timer(&pq->hold_timer, jiffies + pq->timeout))
2797                         xfrm_pol_hold(pol);
2798                 goto out;
2799         }
2800
2801         dst_release(dst);
2802
2803         __skb_queue_head_init(&list);
2804
2805         spin_lock(&pq->hold_queue.lock);
2806         pq->timeout = 0;
2807         skb_queue_splice_init(&pq->hold_queue, &list);
2808         spin_unlock(&pq->hold_queue.lock);
2809
2810         while (!skb_queue_empty(&list)) {
2811                 skb = __skb_dequeue(&list);
2812
2813                 /* Fixup the mark to support VTI. */
2814                 skb_mark = skb->mark;
2815                 skb->mark = pol->mark.v;
2816                 xfrm_decode_session(skb, &fl, skb_dst(skb)->ops->family);
2817                 skb->mark = skb_mark;
2818
2819                 dst_hold(xfrm_dst_path(skb_dst(skb)));
2820                 dst = xfrm_lookup(net, xfrm_dst_path(skb_dst(skb)), &fl, skb->sk, 0);
2821                 if (IS_ERR(dst)) {
2822                         kfree_skb(skb);
2823                         continue;
2824                 }
2825
2826                 nf_reset_ct(skb);
2827                 skb_dst_drop(skb);
2828                 skb_dst_set(skb, dst);
2829
2830                 dst_output(net, skb->sk, skb);
2831         }
2832
2833 out:
2834         xfrm_pol_put(pol);
2835         return;
2836
2837 purge_queue:
2838         pq->timeout = 0;
2839         skb_queue_purge(&pq->hold_queue);
2840         xfrm_pol_put(pol);
2841 }
2842
2843 static int xdst_queue_output(struct net *net, struct sock *sk, struct sk_buff *skb)
2844 {
2845         unsigned long sched_next;
2846         struct dst_entry *dst = skb_dst(skb);
2847         struct xfrm_dst *xdst = (struct xfrm_dst *) dst;
2848         struct xfrm_policy *pol = xdst->pols[0];
2849         struct xfrm_policy_queue *pq = &pol->polq;
2850
2851         if (unlikely(skb_fclone_busy(sk, skb))) {
2852                 kfree_skb(skb);
2853                 return 0;
2854         }
2855
2856         if (pq->hold_queue.qlen > XFRM_MAX_QUEUE_LEN) {
2857                 kfree_skb(skb);
2858                 return -EAGAIN;
2859         }
2860
2861         skb_dst_force(skb);
2862
2863         spin_lock_bh(&pq->hold_queue.lock);
2864
2865         if (!pq->timeout)
2866                 pq->timeout = XFRM_QUEUE_TMO_MIN;
2867
2868         sched_next = jiffies + pq->timeout;
2869
2870         if (del_timer(&pq->hold_timer)) {
2871                 if (time_before(pq->hold_timer.expires, sched_next))
2872                         sched_next = pq->hold_timer.expires;
2873                 xfrm_pol_put(pol);
2874         }
2875
2876         __skb_queue_tail(&pq->hold_queue, skb);
2877         if (!mod_timer(&pq->hold_timer, sched_next))
2878                 xfrm_pol_hold(pol);
2879
2880         spin_unlock_bh(&pq->hold_queue.lock);
2881
2882         return 0;
2883 }
2884
2885 static struct xfrm_dst *xfrm_create_dummy_bundle(struct net *net,
2886                                                  struct xfrm_flo *xflo,
2887                                                  const struct flowi *fl,
2888                                                  int num_xfrms,
2889                                                  u16 family)
2890 {
2891         int err;
2892         struct net_device *dev;
2893         struct dst_entry *dst;
2894         struct dst_entry *dst1;
2895         struct xfrm_dst *xdst;
2896
2897         xdst = xfrm_alloc_dst(net, family);
2898         if (IS_ERR(xdst))
2899                 return xdst;
2900
2901         if (!(xflo->flags & XFRM_LOOKUP_QUEUE) ||
2902             net->xfrm.sysctl_larval_drop ||
2903             num_xfrms <= 0)
2904                 return xdst;
2905
2906         dst = xflo->dst_orig;
2907         dst1 = &xdst->u.dst;
2908         dst_hold(dst);
2909         xdst->route = dst;
2910
2911         dst_copy_metrics(dst1, dst);
2912
2913         dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
2914         dst1->flags |= DST_XFRM_QUEUE;
2915         dst1->lastuse = jiffies;
2916
2917         dst1->input = dst_discard;
2918         dst1->output = xdst_queue_output;
2919
2920         dst_hold(dst);
2921         xfrm_dst_set_child(xdst, dst);
2922         xdst->path = dst;
2923
2924         xfrm_init_path((struct xfrm_dst *)dst1, dst, 0);
2925
2926         err = -ENODEV;
2927         dev = dst->dev;
2928         if (!dev)
2929                 goto free_dst;
2930
2931         err = xfrm_fill_dst(xdst, dev, fl);
2932         if (err)
2933                 goto free_dst;
2934
2935 out:
2936         return xdst;
2937
2938 free_dst:
2939         dst_release(dst1);
2940         xdst = ERR_PTR(err);
2941         goto out;
2942 }
2943
2944 static struct xfrm_dst *xfrm_bundle_lookup(struct net *net,
2945                                            const struct flowi *fl,
2946                                            u16 family, u8 dir,
2947                                            struct xfrm_flo *xflo, u32 if_id)
2948 {
2949         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2950         int num_pols = 0, num_xfrms = 0, err;
2951         struct xfrm_dst *xdst;
2952
2953         /* Resolve policies to use if we couldn't get them from
2954          * previous cache entry */
2955         num_pols = 1;
2956         pols[0] = xfrm_policy_lookup(net, fl, family, dir, if_id);
2957         err = xfrm_expand_policies(fl, family, pols,
2958                                            &num_pols, &num_xfrms);
2959         if (err < 0)
2960                 goto inc_error;
2961         if (num_pols == 0)
2962                 return NULL;
2963         if (num_xfrms <= 0)
2964                 goto make_dummy_bundle;
2965
2966         xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family,
2967                                               xflo->dst_orig);
2968         if (IS_ERR(xdst)) {
2969                 err = PTR_ERR(xdst);
2970                 if (err == -EREMOTE) {
2971                         xfrm_pols_put(pols, num_pols);
2972                         return NULL;
2973                 }
2974
2975                 if (err != -EAGAIN)
2976                         goto error;
2977                 goto make_dummy_bundle;
2978         } else if (xdst == NULL) {
2979                 num_xfrms = 0;
2980                 goto make_dummy_bundle;
2981         }
2982
2983         return xdst;
2984
2985 make_dummy_bundle:
2986         /* We found policies, but there's no bundles to instantiate:
2987          * either because the policy blocks, has no transformations or
2988          * we could not build template (no xfrm_states).*/
2989         xdst = xfrm_create_dummy_bundle(net, xflo, fl, num_xfrms, family);
2990         if (IS_ERR(xdst)) {
2991                 xfrm_pols_put(pols, num_pols);
2992                 return ERR_CAST(xdst);
2993         }
2994         xdst->num_pols = num_pols;
2995         xdst->num_xfrms = num_xfrms;
2996         memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols);
2997
2998         return xdst;
2999
3000 inc_error:
3001         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
3002 error:
3003         xfrm_pols_put(pols, num_pols);
3004         return ERR_PTR(err);
3005 }
3006
3007 static struct dst_entry *make_blackhole(struct net *net, u16 family,
3008                                         struct dst_entry *dst_orig)
3009 {
3010         const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
3011         struct dst_entry *ret;
3012
3013         if (!afinfo) {
3014                 dst_release(dst_orig);
3015                 return ERR_PTR(-EINVAL);
3016         } else {
3017                 ret = afinfo->blackhole_route(net, dst_orig);
3018         }
3019         rcu_read_unlock();
3020
3021         return ret;
3022 }
3023
3024 /* Finds/creates a bundle for given flow and if_id
3025  *
3026  * At the moment we eat a raw IP route. Mostly to speed up lookups
3027  * on interfaces with disabled IPsec.
3028  *
3029  * xfrm_lookup uses an if_id of 0 by default, and is provided for
3030  * compatibility
3031  */
3032 struct dst_entry *xfrm_lookup_with_ifid(struct net *net,
3033                                         struct dst_entry *dst_orig,
3034                                         const struct flowi *fl,
3035                                         const struct sock *sk,
3036                                         int flags, u32 if_id)
3037 {
3038         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
3039         struct xfrm_dst *xdst;
3040         struct dst_entry *dst, *route;
3041         u16 family = dst_orig->ops->family;
3042         u8 dir = XFRM_POLICY_OUT;
3043         int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
3044
3045         dst = NULL;
3046         xdst = NULL;
3047         route = NULL;
3048
3049         sk = sk_const_to_full_sk(sk);
3050         if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
3051                 num_pols = 1;
3052                 pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, family,
3053                                                 if_id);
3054                 err = xfrm_expand_policies(fl, family, pols,
3055                                            &num_pols, &num_xfrms);
3056                 if (err < 0)
3057                         goto dropdst;
3058
3059                 if (num_pols) {
3060                         if (num_xfrms <= 0) {
3061                                 drop_pols = num_pols;
3062                                 goto no_transform;
3063                         }
3064
3065                         xdst = xfrm_resolve_and_create_bundle(
3066                                         pols, num_pols, fl,
3067                                         family, dst_orig);
3068
3069                         if (IS_ERR(xdst)) {
3070                                 xfrm_pols_put(pols, num_pols);
3071                                 err = PTR_ERR(xdst);
3072                                 if (err == -EREMOTE)
3073                                         goto nopol;
3074
3075                                 goto dropdst;
3076                         } else if (xdst == NULL) {
3077                                 num_xfrms = 0;
3078                                 drop_pols = num_pols;
3079                                 goto no_transform;
3080                         }
3081
3082                         route = xdst->route;
3083                 }
3084         }
3085
3086         if (xdst == NULL) {
3087                 struct xfrm_flo xflo;
3088
3089                 xflo.dst_orig = dst_orig;
3090                 xflo.flags = flags;
3091
3092                 /* To accelerate a bit...  */
3093                 if (!if_id && ((dst_orig->flags & DST_NOXFRM) ||
3094                                !net->xfrm.policy_count[XFRM_POLICY_OUT]))
3095                         goto nopol;
3096
3097                 xdst = xfrm_bundle_lookup(net, fl, family, dir, &xflo, if_id);
3098                 if (xdst == NULL)
3099                         goto nopol;
3100                 if (IS_ERR(xdst)) {
3101                         err = PTR_ERR(xdst);
3102                         goto dropdst;
3103                 }
3104
3105                 num_pols = xdst->num_pols;
3106                 num_xfrms = xdst->num_xfrms;
3107                 memcpy(pols, xdst->pols, sizeof(struct xfrm_policy *) * num_pols);
3108                 route = xdst->route;
3109         }
3110
3111         dst = &xdst->u.dst;
3112         if (route == NULL && num_xfrms > 0) {
3113                 /* The only case when xfrm_bundle_lookup() returns a
3114                  * bundle with null route, is when the template could
3115                  * not be resolved. It means policies are there, but
3116                  * bundle could not be created, since we don't yet
3117                  * have the xfrm_state's. We need to wait for KM to
3118                  * negotiate new SA's or bail out with error.*/
3119                 if (net->xfrm.sysctl_larval_drop) {
3120                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
3121                         err = -EREMOTE;
3122                         goto error;
3123                 }
3124
3125                 err = -EAGAIN;
3126
3127                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
3128                 goto error;
3129         }
3130
3131 no_transform:
3132         if (num_pols == 0)
3133                 goto nopol;
3134
3135         if ((flags & XFRM_LOOKUP_ICMP) &&
3136             !(pols[0]->flags & XFRM_POLICY_ICMP)) {
3137                 err = -ENOENT;
3138                 goto error;
3139         }
3140
3141         for (i = 0; i < num_pols; i++)
3142                 pols[i]->curlft.use_time = ktime_get_real_seconds();
3143
3144         if (num_xfrms < 0) {
3145                 /* Prohibit the flow */
3146                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLBLOCK);
3147                 err = -EPERM;
3148                 goto error;
3149         } else if (num_xfrms > 0) {
3150                 /* Flow transformed */
3151                 dst_release(dst_orig);
3152         } else {
3153                 /* Flow passes untransformed */
3154                 dst_release(dst);
3155                 dst = dst_orig;
3156         }
3157 ok:
3158         xfrm_pols_put(pols, drop_pols);
3159         if (dst && dst->xfrm &&
3160             dst->xfrm->props.mode == XFRM_MODE_TUNNEL)
3161                 dst->flags |= DST_XFRM_TUNNEL;
3162         return dst;
3163
3164 nopol:
3165         if ((!dst_orig->dev || !(dst_orig->dev->flags & IFF_LOOPBACK)) &&
3166             net->xfrm.policy_default[dir] == XFRM_USERPOLICY_BLOCK) {
3167                 err = -EPERM;
3168                 goto error;
3169         }
3170         if (!(flags & XFRM_LOOKUP_ICMP)) {
3171                 dst = dst_orig;
3172                 goto ok;
3173         }
3174         err = -ENOENT;
3175 error:
3176         dst_release(dst);
3177 dropdst:
3178         if (!(flags & XFRM_LOOKUP_KEEP_DST_REF))
3179                 dst_release(dst_orig);
3180         xfrm_pols_put(pols, drop_pols);
3181         return ERR_PTR(err);
3182 }
3183 EXPORT_SYMBOL(xfrm_lookup_with_ifid);
3184
3185 /* Main function: finds/creates a bundle for given flow.
3186  *
3187  * At the moment we eat a raw IP route. Mostly to speed up lookups
3188  * on interfaces with disabled IPsec.
3189  */
3190 struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
3191                               const struct flowi *fl, const struct sock *sk,
3192                               int flags)
3193 {
3194         return xfrm_lookup_with_ifid(net, dst_orig, fl, sk, flags, 0);
3195 }
3196 EXPORT_SYMBOL(xfrm_lookup);
3197
3198 /* Callers of xfrm_lookup_route() must ensure a call to dst_output().
3199  * Otherwise we may send out blackholed packets.
3200  */
3201 struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
3202                                     const struct flowi *fl,
3203                                     const struct sock *sk, int flags)
3204 {
3205         struct dst_entry *dst = xfrm_lookup(net, dst_orig, fl, sk,
3206                                             flags | XFRM_LOOKUP_QUEUE |
3207                                             XFRM_LOOKUP_KEEP_DST_REF);
3208
3209         if (PTR_ERR(dst) == -EREMOTE)
3210                 return make_blackhole(net, dst_orig->ops->family, dst_orig);
3211
3212         if (IS_ERR(dst))
3213                 dst_release(dst_orig);
3214
3215         return dst;
3216 }
3217 EXPORT_SYMBOL(xfrm_lookup_route);
3218
3219 static inline int
3220 xfrm_secpath_reject(int idx, struct sk_buff *skb, const struct flowi *fl)
3221 {
3222         struct sec_path *sp = skb_sec_path(skb);
3223         struct xfrm_state *x;
3224
3225         if (!sp || idx < 0 || idx >= sp->len)
3226                 return 0;
3227         x = sp->xvec[idx];
3228         if (!x->type->reject)
3229                 return 0;
3230         return x->type->reject(x, skb, fl);
3231 }
3232
3233 /* When skb is transformed back to its "native" form, we have to
3234  * check policy restrictions. At the moment we make this in maximally
3235  * stupid way. Shame on me. :-) Of course, connected sockets must
3236  * have policy cached at them.
3237  */
3238
3239 static inline int
3240 xfrm_state_ok(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x,
3241               unsigned short family)
3242 {
3243         if (xfrm_state_kern(x))
3244                 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
3245         return  x->id.proto == tmpl->id.proto &&
3246                 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
3247                 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
3248                 x->props.mode == tmpl->mode &&
3249                 (tmpl->allalgs || (tmpl->aalgos & (1<<x->props.aalgo)) ||
3250                  !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
3251                 !(x->props.mode != XFRM_MODE_TRANSPORT &&
3252                   xfrm_state_addr_cmp(tmpl, x, family));
3253 }
3254
3255 /*
3256  * 0 or more than 0 is returned when validation is succeeded (either bypass
3257  * because of optional transport mode, or next index of the matched secpath
3258  * state with the template.
3259  * -1 is returned when no matching template is found.
3260  * Otherwise "-2 - errored_index" is returned.
3261  */
3262 static inline int
3263 xfrm_policy_ok(const struct xfrm_tmpl *tmpl, const struct sec_path *sp, int start,
3264                unsigned short family)
3265 {
3266         int idx = start;
3267
3268         if (tmpl->optional) {
3269                 if (tmpl->mode == XFRM_MODE_TRANSPORT)
3270                         return start;
3271         } else
3272                 start = -1;
3273         for (; idx < sp->len; idx++) {
3274                 if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
3275                         return ++idx;
3276                 if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
3277                         if (start == -1)
3278                                 start = -2-idx;
3279                         break;
3280                 }
3281         }
3282         return start;
3283 }
3284
3285 static void
3286 decode_session4(struct sk_buff *skb, struct flowi *fl, bool reverse)
3287 {
3288         const struct iphdr *iph = ip_hdr(skb);
3289         int ihl = iph->ihl;
3290         u8 *xprth = skb_network_header(skb) + ihl * 4;
3291         struct flowi4 *fl4 = &fl->u.ip4;
3292         int oif = 0;
3293
3294         if (skb_dst(skb) && skb_dst(skb)->dev)
3295                 oif = skb_dst(skb)->dev->ifindex;
3296
3297         memset(fl4, 0, sizeof(struct flowi4));
3298         fl4->flowi4_mark = skb->mark;
3299         fl4->flowi4_oif = reverse ? skb->skb_iif : oif;
3300
3301         fl4->flowi4_proto = iph->protocol;
3302         fl4->daddr = reverse ? iph->saddr : iph->daddr;
3303         fl4->saddr = reverse ? iph->daddr : iph->saddr;
3304         fl4->flowi4_tos = iph->tos & ~INET_ECN_MASK;
3305
3306         if (!ip_is_fragment(iph)) {
3307                 switch (iph->protocol) {
3308                 case IPPROTO_UDP:
3309                 case IPPROTO_UDPLITE:
3310                 case IPPROTO_TCP:
3311                 case IPPROTO_SCTP:
3312                 case IPPROTO_DCCP:
3313                         if (xprth + 4 < skb->data ||
3314                             pskb_may_pull(skb, xprth + 4 - skb->data)) {
3315                                 __be16 *ports;
3316
3317                                 xprth = skb_network_header(skb) + ihl * 4;
3318                                 ports = (__be16 *)xprth;
3319
3320                                 fl4->fl4_sport = ports[!!reverse];
3321                                 fl4->fl4_dport = ports[!reverse];
3322                         }
3323                         break;
3324                 case IPPROTO_ICMP:
3325                         if (xprth + 2 < skb->data ||
3326                             pskb_may_pull(skb, xprth + 2 - skb->data)) {
3327                                 u8 *icmp;
3328
3329                                 xprth = skb_network_header(skb) + ihl * 4;
3330                                 icmp = xprth;
3331
3332                                 fl4->fl4_icmp_type = icmp[0];
3333                                 fl4->fl4_icmp_code = icmp[1];
3334                         }
3335                         break;
3336                 case IPPROTO_GRE:
3337                         if (xprth + 12 < skb->data ||
3338                             pskb_may_pull(skb, xprth + 12 - skb->data)) {
3339                                 __be16 *greflags;
3340                                 __be32 *gre_hdr;
3341
3342                                 xprth = skb_network_header(skb) + ihl * 4;
3343                                 greflags = (__be16 *)xprth;
3344                                 gre_hdr = (__be32 *)xprth;
3345
3346                                 if (greflags[0] & GRE_KEY) {
3347                                         if (greflags[0] & GRE_CSUM)
3348                                                 gre_hdr++;
3349                                         fl4->fl4_gre_key = gre_hdr[1];
3350                                 }
3351                         }
3352                         break;
3353                 default:
3354                         break;
3355                 }
3356         }
3357 }
3358
3359 #if IS_ENABLED(CONFIG_IPV6)
3360 static void
3361 decode_session6(struct sk_buff *skb, struct flowi *fl, bool reverse)
3362 {
3363         struct flowi6 *fl6 = &fl->u.ip6;
3364         int onlyproto = 0;
3365         const struct ipv6hdr *hdr = ipv6_hdr(skb);
3366         u32 offset = sizeof(*hdr);
3367         struct ipv6_opt_hdr *exthdr;
3368         const unsigned char *nh = skb_network_header(skb);
3369         u16 nhoff = IP6CB(skb)->nhoff;
3370         int oif = 0;
3371         u8 nexthdr;
3372
3373         if (!nhoff)
3374                 nhoff = offsetof(struct ipv6hdr, nexthdr);
3375
3376         nexthdr = nh[nhoff];
3377
3378         if (skb_dst(skb) && skb_dst(skb)->dev)
3379                 oif = skb_dst(skb)->dev->ifindex;
3380
3381         memset(fl6, 0, sizeof(struct flowi6));
3382         fl6->flowi6_mark = skb->mark;
3383         fl6->flowi6_oif = reverse ? skb->skb_iif : oif;
3384
3385         fl6->daddr = reverse ? hdr->saddr : hdr->daddr;
3386         fl6->saddr = reverse ? hdr->daddr : hdr->saddr;
3387
3388         while (nh + offset + sizeof(*exthdr) < skb->data ||
3389                pskb_may_pull(skb, nh + offset + sizeof(*exthdr) - skb->data)) {
3390                 nh = skb_network_header(skb);
3391                 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
3392
3393                 switch (nexthdr) {
3394                 case NEXTHDR_FRAGMENT:
3395                         onlyproto = 1;
3396                         fallthrough;
3397                 case NEXTHDR_ROUTING:
3398                 case NEXTHDR_HOP:
3399                 case NEXTHDR_DEST:
3400                         offset += ipv6_optlen(exthdr);
3401                         nexthdr = exthdr->nexthdr;
3402                         break;
3403                 case IPPROTO_UDP:
3404                 case IPPROTO_UDPLITE:
3405                 case IPPROTO_TCP:
3406                 case IPPROTO_SCTP:
3407                 case IPPROTO_DCCP:
3408                         if (!onlyproto && (nh + offset + 4 < skb->data ||
3409                              pskb_may_pull(skb, nh + offset + 4 - skb->data))) {
3410                                 __be16 *ports;
3411
3412                                 nh = skb_network_header(skb);
3413                                 ports = (__be16 *)(nh + offset);
3414                                 fl6->fl6_sport = ports[!!reverse];
3415                                 fl6->fl6_dport = ports[!reverse];
3416                         }
3417                         fl6->flowi6_proto = nexthdr;
3418                         return;
3419                 case IPPROTO_ICMPV6:
3420                         if (!onlyproto && (nh + offset + 2 < skb->data ||
3421                             pskb_may_pull(skb, nh + offset + 2 - skb->data))) {
3422                                 u8 *icmp;
3423
3424                                 nh = skb_network_header(skb);
3425                                 icmp = (u8 *)(nh + offset);
3426                                 fl6->fl6_icmp_type = icmp[0];
3427                                 fl6->fl6_icmp_code = icmp[1];
3428                         }
3429                         fl6->flowi6_proto = nexthdr;
3430                         return;
3431                 case IPPROTO_GRE:
3432                         if (!onlyproto &&
3433                             (nh + offset + 12 < skb->data ||
3434                              pskb_may_pull(skb, nh + offset + 12 - skb->data))) {
3435                                 struct gre_base_hdr *gre_hdr;
3436                                 __be32 *gre_key;
3437
3438                                 nh = skb_network_header(skb);
3439                                 gre_hdr = (struct gre_base_hdr *)(nh + offset);
3440                                 gre_key = (__be32 *)(gre_hdr + 1);
3441
3442                                 if (gre_hdr->flags & GRE_KEY) {
3443                                         if (gre_hdr->flags & GRE_CSUM)
3444                                                 gre_key++;
3445                                         fl6->fl6_gre_key = *gre_key;
3446                                 }
3447                         }
3448                         fl6->flowi6_proto = nexthdr;
3449                         return;
3450
3451 #if IS_ENABLED(CONFIG_IPV6_MIP6)
3452                 case IPPROTO_MH:
3453                         offset += ipv6_optlen(exthdr);
3454                         if (!onlyproto && (nh + offset + 3 < skb->data ||
3455                             pskb_may_pull(skb, nh + offset + 3 - skb->data))) {
3456                                 struct ip6_mh *mh;
3457
3458                                 nh = skb_network_header(skb);
3459                                 mh = (struct ip6_mh *)(nh + offset);
3460                                 fl6->fl6_mh_type = mh->ip6mh_type;
3461                         }
3462                         fl6->flowi6_proto = nexthdr;
3463                         return;
3464 #endif
3465                 default:
3466                         fl6->flowi6_proto = nexthdr;
3467                         return;
3468                 }
3469         }
3470 }
3471 #endif
3472
3473 int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
3474                           unsigned int family, int reverse)
3475 {
3476         switch (family) {
3477         case AF_INET:
3478                 decode_session4(skb, fl, reverse);
3479                 break;
3480 #if IS_ENABLED(CONFIG_IPV6)
3481         case AF_INET6:
3482                 decode_session6(skb, fl, reverse);
3483                 break;
3484 #endif
3485         default:
3486                 return -EAFNOSUPPORT;
3487         }
3488
3489         return security_xfrm_decode_session(skb, &fl->flowi_secid);
3490 }
3491 EXPORT_SYMBOL(__xfrm_decode_session);
3492
3493 static inline int secpath_has_nontransport(const struct sec_path *sp, int k, int *idxp)
3494 {
3495         for (; k < sp->len; k++) {
3496                 if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
3497                         *idxp = k;
3498                         return 1;
3499                 }
3500         }
3501
3502         return 0;
3503 }
3504
3505 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
3506                         unsigned short family)
3507 {
3508         struct net *net = dev_net(skb->dev);
3509         struct xfrm_policy *pol;
3510         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
3511         int npols = 0;
3512         int xfrm_nr;
3513         int pi;
3514         int reverse;
3515         struct flowi fl;
3516         int xerr_idx = -1;
3517         const struct xfrm_if_cb *ifcb;
3518         struct sec_path *sp;
3519         struct xfrm_if *xi;
3520         u32 if_id = 0;
3521
3522         rcu_read_lock();
3523         ifcb = xfrm_if_get_cb();
3524
3525         if (ifcb) {
3526                 xi = ifcb->decode_session(skb, family);
3527                 if (xi) {
3528                         if_id = xi->p.if_id;
3529                         net = xi->net;
3530                 }
3531         }
3532         rcu_read_unlock();
3533
3534         reverse = dir & ~XFRM_POLICY_MASK;
3535         dir &= XFRM_POLICY_MASK;
3536
3537         if (__xfrm_decode_session(skb, &fl, family, reverse) < 0) {
3538                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
3539                 return 0;
3540         }
3541
3542         nf_nat_decode_session(skb, &fl, family);
3543
3544         /* First, check used SA against their selectors. */
3545         sp = skb_sec_path(skb);
3546         if (sp) {
3547                 int i;
3548
3549                 for (i = sp->len - 1; i >= 0; i--) {
3550                         struct xfrm_state *x = sp->xvec[i];
3551                         if (!xfrm_selector_match(&x->sel, &fl, family)) {
3552                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
3553                                 return 0;
3554                         }
3555                 }
3556         }
3557
3558         pol = NULL;
3559         sk = sk_to_full_sk(sk);
3560         if (sk && sk->sk_policy[dir]) {
3561                 pol = xfrm_sk_policy_lookup(sk, dir, &fl, family, if_id);
3562                 if (IS_ERR(pol)) {
3563                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
3564                         return 0;
3565                 }
3566         }
3567
3568         if (!pol)
3569                 pol = xfrm_policy_lookup(net, &fl, family, dir, if_id);
3570
3571         if (IS_ERR(pol)) {
3572                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
3573                 return 0;
3574         }
3575
3576         if (!pol) {
3577                 if (net->xfrm.policy_default[dir] == XFRM_USERPOLICY_BLOCK) {
3578                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
3579                         return 0;
3580                 }
3581
3582                 if (sp && secpath_has_nontransport(sp, 0, &xerr_idx)) {
3583                         xfrm_secpath_reject(xerr_idx, skb, &fl);
3584                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
3585                         return 0;
3586                 }
3587                 return 1;
3588         }
3589
3590         pol->curlft.use_time = ktime_get_real_seconds();
3591
3592         pols[0] = pol;
3593         npols++;
3594 #ifdef CONFIG_XFRM_SUB_POLICY
3595         if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
3596                 pols[1] = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN,
3597                                                     &fl, family,
3598                                                     XFRM_POLICY_IN, if_id);
3599                 if (pols[1]) {
3600                         if (IS_ERR(pols[1])) {
3601                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
3602                                 xfrm_pol_put(pols[0]);
3603                                 return 0;
3604                         }
3605                         pols[1]->curlft.use_time = ktime_get_real_seconds();
3606                         npols++;
3607                 }
3608         }
3609 #endif
3610
3611         if (pol->action == XFRM_POLICY_ALLOW) {
3612                 static struct sec_path dummy;
3613                 struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
3614                 struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
3615                 struct xfrm_tmpl **tpp = tp;
3616                 int ti = 0;
3617                 int i, k;
3618
3619                 sp = skb_sec_path(skb);
3620                 if (!sp)
3621                         sp = &dummy;
3622
3623                 for (pi = 0; pi < npols; pi++) {
3624                         if (pols[pi] != pol &&
3625                             pols[pi]->action != XFRM_POLICY_ALLOW) {
3626                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
3627                                 goto reject;
3628                         }
3629                         if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH) {
3630                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
3631                                 goto reject_error;
3632                         }
3633                         for (i = 0; i < pols[pi]->xfrm_nr; i++)
3634                                 tpp[ti++] = &pols[pi]->xfrm_vec[i];
3635                 }
3636                 xfrm_nr = ti;
3637
3638                 if (net->xfrm.policy_default[dir] == XFRM_USERPOLICY_BLOCK &&
3639                     !xfrm_nr) {
3640                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
3641                         goto reject;
3642                 }
3643
3644                 if (npols > 1) {
3645                         xfrm_tmpl_sort(stp, tpp, xfrm_nr, family);
3646                         tpp = stp;
3647                 }
3648
3649                 /* For each tunnel xfrm, find the first matching tmpl.
3650                  * For each tmpl before that, find corresponding xfrm.
3651                  * Order is _important_. Later we will implement
3652                  * some barriers, but at the moment barriers
3653                  * are implied between each two transformations.
3654                  */
3655                 for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
3656                         k = xfrm_policy_ok(tpp[i], sp, k, family);
3657                         if (k < 0) {
3658                                 if (k < -1)
3659                                         /* "-2 - errored_index" returned */
3660                                         xerr_idx = -(2+k);
3661                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
3662                                 goto reject;
3663                         }
3664                 }
3665
3666                 if (secpath_has_nontransport(sp, k, &xerr_idx)) {
3667                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
3668                         goto reject;
3669                 }
3670
3671                 xfrm_pols_put(pols, npols);
3672                 return 1;
3673         }
3674         XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
3675
3676 reject:
3677         xfrm_secpath_reject(xerr_idx, skb, &fl);
3678 reject_error:
3679         xfrm_pols_put(pols, npols);
3680         return 0;
3681 }
3682 EXPORT_SYMBOL(__xfrm_policy_check);
3683
3684 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
3685 {
3686         struct net *net = dev_net(skb->dev);
3687         struct flowi fl;
3688         struct dst_entry *dst;
3689         int res = 1;
3690
3691         if (xfrm_decode_session(skb, &fl, family) < 0) {
3692                 XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
3693                 return 0;
3694         }
3695
3696         skb_dst_force(skb);
3697         if (!skb_dst(skb)) {
3698                 XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
3699                 return 0;
3700         }
3701
3702         dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, XFRM_LOOKUP_QUEUE);
3703         if (IS_ERR(dst)) {
3704                 res = 0;
3705                 dst = NULL;
3706         }
3707         skb_dst_set(skb, dst);
3708         return res;
3709 }
3710 EXPORT_SYMBOL(__xfrm_route_forward);
3711
3712 /* Optimize later using cookies and generation ids. */
3713
3714 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
3715 {
3716         /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
3717          * to DST_OBSOLETE_FORCE_CHK to force all XFRM destinations to
3718          * get validated by dst_ops->check on every use.  We do this
3719          * because when a normal route referenced by an XFRM dst is
3720          * obsoleted we do not go looking around for all parent
3721          * referencing XFRM dsts so that we can invalidate them.  It
3722          * is just too much work.  Instead we make the checks here on
3723          * every use.  For example:
3724          *
3725          *      XFRM dst A --> IPv4 dst X
3726          *
3727          * X is the "xdst->route" of A (X is also the "dst->path" of A
3728          * in this example).  If X is marked obsolete, "A" will not
3729          * notice.  That's what we are validating here via the
3730          * stale_bundle() check.
3731          *
3732          * When a dst is removed from the fib tree, DST_OBSOLETE_DEAD will
3733          * be marked on it.
3734          * This will force stale_bundle() to fail on any xdst bundle with
3735          * this dst linked in it.
3736          */
3737         if (dst->obsolete < 0 && !stale_bundle(dst))
3738                 return dst;
3739
3740         return NULL;
3741 }
3742
3743 static int stale_bundle(struct dst_entry *dst)
3744 {
3745         return !xfrm_bundle_ok((struct xfrm_dst *)dst);
3746 }
3747
3748 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
3749 {
3750         while ((dst = xfrm_dst_child(dst)) && dst->xfrm && dst->dev == dev) {
3751                 dst->dev = blackhole_netdev;
3752                 dev_hold(dst->dev);
3753                 dev_put(dev);
3754         }
3755 }
3756 EXPORT_SYMBOL(xfrm_dst_ifdown);
3757
3758 static void xfrm_link_failure(struct sk_buff *skb)
3759 {
3760         /* Impossible. Such dst must be popped before reaches point of failure. */
3761 }
3762
3763 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
3764 {
3765         if (dst) {
3766                 if (dst->obsolete) {
3767                         dst_release(dst);
3768                         dst = NULL;
3769                 }
3770         }
3771         return dst;
3772 }
3773
3774 static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr)
3775 {
3776         while (nr--) {
3777                 struct xfrm_dst *xdst = bundle[nr];
3778                 u32 pmtu, route_mtu_cached;
3779                 struct dst_entry *dst;
3780
3781                 dst = &xdst->u.dst;
3782                 pmtu = dst_mtu(xfrm_dst_child(dst));
3783                 xdst->child_mtu_cached = pmtu;
3784
3785                 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
3786
3787                 route_mtu_cached = dst_mtu(xdst->route);
3788                 xdst->route_mtu_cached = route_mtu_cached;
3789
3790                 if (pmtu > route_mtu_cached)
3791                         pmtu = route_mtu_cached;
3792
3793                 dst_metric_set(dst, RTAX_MTU, pmtu);
3794         }
3795 }
3796
3797 /* Check that the bundle accepts the flow and its components are
3798  * still valid.
3799  */
3800
3801 static int xfrm_bundle_ok(struct xfrm_dst *first)
3802 {
3803         struct xfrm_dst *bundle[XFRM_MAX_DEPTH];
3804         struct dst_entry *dst = &first->u.dst;
3805         struct xfrm_dst *xdst;
3806         int start_from, nr;
3807         u32 mtu;
3808
3809         if (!dst_check(xfrm_dst_path(dst), ((struct xfrm_dst *)dst)->path_cookie) ||
3810             (dst->dev && !netif_running(dst->dev)))
3811                 return 0;
3812
3813         if (dst->flags & DST_XFRM_QUEUE)
3814                 return 1;
3815
3816         start_from = nr = 0;
3817         do {
3818                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
3819
3820                 if (dst->xfrm->km.state != XFRM_STATE_VALID)
3821                         return 0;
3822                 if (xdst->xfrm_genid != dst->xfrm->genid)
3823                         return 0;
3824                 if (xdst->num_pols > 0 &&
3825                     xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
3826                         return 0;
3827
3828                 bundle[nr++] = xdst;
3829
3830                 mtu = dst_mtu(xfrm_dst_child(dst));
3831                 if (xdst->child_mtu_cached != mtu) {
3832                         start_from = nr;
3833                         xdst->child_mtu_cached = mtu;
3834                 }
3835
3836                 if (!dst_check(xdst->route, xdst->route_cookie))
3837                         return 0;
3838                 mtu = dst_mtu(xdst->route);
3839                 if (xdst->route_mtu_cached != mtu) {
3840                         start_from = nr;
3841                         xdst->route_mtu_cached = mtu;
3842                 }
3843
3844                 dst = xfrm_dst_child(dst);
3845         } while (dst->xfrm);
3846
3847         if (likely(!start_from))
3848                 return 1;
3849
3850         xdst = bundle[start_from - 1];
3851         mtu = xdst->child_mtu_cached;
3852         while (start_from--) {
3853                 dst = &xdst->u.dst;
3854
3855                 mtu = xfrm_state_mtu(dst->xfrm, mtu);
3856                 if (mtu > xdst->route_mtu_cached)
3857                         mtu = xdst->route_mtu_cached;
3858                 dst_metric_set(dst, RTAX_MTU, mtu);
3859                 if (!start_from)
3860                         break;
3861
3862                 xdst = bundle[start_from - 1];
3863                 xdst->child_mtu_cached = mtu;
3864         }
3865
3866         return 1;
3867 }
3868
3869 static unsigned int xfrm_default_advmss(const struct dst_entry *dst)
3870 {
3871         return dst_metric_advmss(xfrm_dst_path(dst));
3872 }
3873
3874 static unsigned int xfrm_mtu(const struct dst_entry *dst)
3875 {
3876         unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
3877
3878         return mtu ? : dst_mtu(xfrm_dst_path(dst));
3879 }
3880
3881 static const void *xfrm_get_dst_nexthop(const struct dst_entry *dst,
3882                                         const void *daddr)
3883 {
3884         while (dst->xfrm) {
3885                 const struct xfrm_state *xfrm = dst->xfrm;
3886
3887                 dst = xfrm_dst_child(dst);
3888
3889                 if (xfrm->props.mode == XFRM_MODE_TRANSPORT)
3890                         continue;
3891                 if (xfrm->type->flags & XFRM_TYPE_REMOTE_COADDR)
3892                         daddr = xfrm->coaddr;
3893                 else if (!(xfrm->type->flags & XFRM_TYPE_LOCAL_COADDR))
3894                         daddr = &xfrm->id.daddr;
3895         }
3896         return daddr;
3897 }
3898
3899 static struct neighbour *xfrm_neigh_lookup(const struct dst_entry *dst,
3900                                            struct sk_buff *skb,
3901                                            const void *daddr)
3902 {
3903         const struct dst_entry *path = xfrm_dst_path(dst);
3904
3905         if (!skb)
3906                 daddr = xfrm_get_dst_nexthop(dst, daddr);
3907         return path->ops->neigh_lookup(path, skb, daddr);
3908 }
3909
3910 static void xfrm_confirm_neigh(const struct dst_entry *dst, const void *daddr)
3911 {
3912         const struct dst_entry *path = xfrm_dst_path(dst);
3913
3914         daddr = xfrm_get_dst_nexthop(dst, daddr);
3915         path->ops->confirm_neigh(path, daddr);
3916 }
3917
3918 int xfrm_policy_register_afinfo(const struct xfrm_policy_afinfo *afinfo, int family)
3919 {
3920         int err = 0;
3921
3922         if (WARN_ON(family >= ARRAY_SIZE(xfrm_policy_afinfo)))
3923                 return -EAFNOSUPPORT;
3924
3925         spin_lock(&xfrm_policy_afinfo_lock);
3926         if (unlikely(xfrm_policy_afinfo[family] != NULL))
3927                 err = -EEXIST;
3928         else {
3929                 struct dst_ops *dst_ops = afinfo->dst_ops;
3930                 if (likely(dst_ops->kmem_cachep == NULL))
3931                         dst_ops->kmem_cachep = xfrm_dst_cache;
3932                 if (likely(dst_ops->check == NULL))
3933                         dst_ops->check = xfrm_dst_check;
3934                 if (likely(dst_ops->default_advmss == NULL))
3935                         dst_ops->default_advmss = xfrm_default_advmss;
3936                 if (likely(dst_ops->mtu == NULL))
3937                         dst_ops->mtu = xfrm_mtu;
3938                 if (likely(dst_ops->negative_advice == NULL))
3939                         dst_ops->negative_advice = xfrm_negative_advice;
3940                 if (likely(dst_ops->link_failure == NULL))
3941                         dst_ops->link_failure = xfrm_link_failure;
3942                 if (likely(dst_ops->neigh_lookup == NULL))
3943                         dst_ops->neigh_lookup = xfrm_neigh_lookup;
3944                 if (likely(!dst_ops->confirm_neigh))
3945                         dst_ops->confirm_neigh = xfrm_confirm_neigh;
3946                 rcu_assign_pointer(xfrm_policy_afinfo[family], afinfo);
3947         }
3948         spin_unlock(&xfrm_policy_afinfo_lock);
3949
3950         return err;
3951 }
3952 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
3953
3954 void xfrm_policy_unregister_afinfo(const struct xfrm_policy_afinfo *afinfo)
3955 {
3956         struct dst_ops *dst_ops = afinfo->dst_ops;
3957         int i;
3958
3959         for (i = 0; i < ARRAY_SIZE(xfrm_policy_afinfo); i++) {
3960                 if (xfrm_policy_afinfo[i] != afinfo)
3961                         continue;
3962                 RCU_INIT_POINTER(xfrm_policy_afinfo[i], NULL);
3963                 break;
3964         }
3965
3966         synchronize_rcu();
3967
3968         dst_ops->kmem_cachep = NULL;
3969         dst_ops->check = NULL;
3970         dst_ops->negative_advice = NULL;
3971         dst_ops->link_failure = NULL;
3972 }
3973 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
3974
3975 void xfrm_if_register_cb(const struct xfrm_if_cb *ifcb)
3976 {
3977         spin_lock(&xfrm_if_cb_lock);
3978         rcu_assign_pointer(xfrm_if_cb, ifcb);
3979         spin_unlock(&xfrm_if_cb_lock);
3980 }
3981 EXPORT_SYMBOL(xfrm_if_register_cb);
3982
3983 void xfrm_if_unregister_cb(void)
3984 {
3985         RCU_INIT_POINTER(xfrm_if_cb, NULL);
3986         synchronize_rcu();
3987 }
3988 EXPORT_SYMBOL(xfrm_if_unregister_cb);
3989
3990 #ifdef CONFIG_XFRM_STATISTICS
3991 static int __net_init xfrm_statistics_init(struct net *net)
3992 {
3993         int rv;
3994         net->mib.xfrm_statistics = alloc_percpu(struct linux_xfrm_mib);
3995         if (!net->mib.xfrm_statistics)
3996                 return -ENOMEM;
3997         rv = xfrm_proc_init(net);
3998         if (rv < 0)
3999                 free_percpu(net->mib.xfrm_statistics);
4000         return rv;
4001 }
4002
4003 static void xfrm_statistics_fini(struct net *net)
4004 {
4005         xfrm_proc_fini(net);
4006         free_percpu(net->mib.xfrm_statistics);
4007 }
4008 #else
4009 static int __net_init xfrm_statistics_init(struct net *net)
4010 {
4011         return 0;
4012 }
4013
4014 static void xfrm_statistics_fini(struct net *net)
4015 {
4016 }
4017 #endif
4018
4019 static int __net_init xfrm_policy_init(struct net *net)
4020 {
4021         unsigned int hmask, sz;
4022         int dir, err;
4023
4024         if (net_eq(net, &init_net)) {
4025                 xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
4026                                            sizeof(struct xfrm_dst),
4027                                            0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
4028                                            NULL);
4029                 err = rhashtable_init(&xfrm_policy_inexact_table,
4030                                       &xfrm_pol_inexact_params);
4031                 BUG_ON(err);
4032         }
4033
4034         hmask = 8 - 1;
4035         sz = (hmask+1) * sizeof(struct hlist_head);
4036
4037         net->xfrm.policy_byidx = xfrm_hash_alloc(sz);
4038         if (!net->xfrm.policy_byidx)
4039                 goto out_byidx;
4040         net->xfrm.policy_idx_hmask = hmask;
4041
4042         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
4043                 struct xfrm_policy_hash *htab;
4044
4045                 net->xfrm.policy_count[dir] = 0;
4046                 net->xfrm.policy_count[XFRM_POLICY_MAX + dir] = 0;
4047                 INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
4048
4049                 htab = &net->xfrm.policy_bydst[dir];
4050                 htab->table = xfrm_hash_alloc(sz);
4051                 if (!htab->table)
4052                         goto out_bydst;
4053                 htab->hmask = hmask;
4054                 htab->dbits4 = 32;
4055                 htab->sbits4 = 32;
4056                 htab->dbits6 = 128;
4057                 htab->sbits6 = 128;
4058         }
4059         net->xfrm.policy_hthresh.lbits4 = 32;
4060         net->xfrm.policy_hthresh.rbits4 = 32;
4061         net->xfrm.policy_hthresh.lbits6 = 128;
4062         net->xfrm.policy_hthresh.rbits6 = 128;
4063
4064         seqlock_init(&net->xfrm.policy_hthresh.lock);
4065
4066         INIT_LIST_HEAD(&net->xfrm.policy_all);
4067         INIT_LIST_HEAD(&net->xfrm.inexact_bins);
4068         INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
4069         INIT_WORK(&net->xfrm.policy_hthresh.work, xfrm_hash_rebuild);
4070         return 0;
4071
4072 out_bydst:
4073         for (dir--; dir >= 0; dir--) {
4074                 struct xfrm_policy_hash *htab;
4075
4076                 htab = &net->xfrm.policy_bydst[dir];
4077                 xfrm_hash_free(htab->table, sz);
4078         }
4079         xfrm_hash_free(net->xfrm.policy_byidx, sz);
4080 out_byidx:
4081         return -ENOMEM;
4082 }
4083
4084 static void xfrm_policy_fini(struct net *net)
4085 {
4086         struct xfrm_pol_inexact_bin *b, *t;
4087         unsigned int sz;
4088         int dir;
4089
4090         flush_work(&net->xfrm.policy_hash_work);
4091 #ifdef CONFIG_XFRM_SUB_POLICY
4092         xfrm_policy_flush(net, XFRM_POLICY_TYPE_SUB, false);
4093 #endif
4094         xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, false);
4095
4096         WARN_ON(!list_empty(&net->xfrm.policy_all));
4097
4098         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
4099                 struct xfrm_policy_hash *htab;
4100
4101                 WARN_ON(!hlist_empty(&net->xfrm.policy_inexact[dir]));
4102
4103                 htab = &net->xfrm.policy_bydst[dir];
4104                 sz = (htab->hmask + 1) * sizeof(struct hlist_head);
4105                 WARN_ON(!hlist_empty(htab->table));
4106                 xfrm_hash_free(htab->table, sz);
4107         }
4108
4109         sz = (net->xfrm.policy_idx_hmask + 1) * sizeof(struct hlist_head);
4110         WARN_ON(!hlist_empty(net->xfrm.policy_byidx));
4111         xfrm_hash_free(net->xfrm.policy_byidx, sz);
4112
4113         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
4114         list_for_each_entry_safe(b, t, &net->xfrm.inexact_bins, inexact_bins)
4115                 __xfrm_policy_inexact_prune_bin(b, true);
4116         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
4117 }
4118
4119 static int __net_init xfrm_net_init(struct net *net)
4120 {
4121         int rv;
4122
4123         /* Initialize the per-net locks here */
4124         spin_lock_init(&net->xfrm.xfrm_state_lock);
4125         spin_lock_init(&net->xfrm.xfrm_policy_lock);
4126         seqcount_spinlock_init(&net->xfrm.xfrm_policy_hash_generation, &net->xfrm.xfrm_policy_lock);
4127         mutex_init(&net->xfrm.xfrm_cfg_mutex);
4128         net->xfrm.policy_default[XFRM_POLICY_IN] = XFRM_USERPOLICY_ACCEPT;
4129         net->xfrm.policy_default[XFRM_POLICY_FWD] = XFRM_USERPOLICY_ACCEPT;
4130         net->xfrm.policy_default[XFRM_POLICY_OUT] = XFRM_USERPOLICY_ACCEPT;
4131
4132         rv = xfrm_statistics_init(net);
4133         if (rv < 0)
4134                 goto out_statistics;
4135         rv = xfrm_state_init(net);
4136         if (rv < 0)
4137                 goto out_state;
4138         rv = xfrm_policy_init(net);
4139         if (rv < 0)
4140                 goto out_policy;
4141         rv = xfrm_sysctl_init(net);
4142         if (rv < 0)
4143                 goto out_sysctl;
4144
4145         return 0;
4146
4147 out_sysctl:
4148         xfrm_policy_fini(net);
4149 out_policy:
4150         xfrm_state_fini(net);
4151 out_state:
4152         xfrm_statistics_fini(net);
4153 out_statistics:
4154         return rv;
4155 }
4156
4157 static void __net_exit xfrm_net_exit(struct net *net)
4158 {
4159         xfrm_sysctl_fini(net);
4160         xfrm_policy_fini(net);
4161         xfrm_state_fini(net);
4162         xfrm_statistics_fini(net);
4163 }
4164
4165 static struct pernet_operations __net_initdata xfrm_net_ops = {
4166         .init = xfrm_net_init,
4167         .exit = xfrm_net_exit,
4168 };
4169
4170 void __init xfrm_init(void)
4171 {
4172         register_pernet_subsys(&xfrm_net_ops);
4173         xfrm_dev_init();
4174         xfrm_input_init();
4175
4176 #ifdef CONFIG_XFRM_ESPINTCP
4177         espintcp_init();
4178 #endif
4179 }
4180
4181 #ifdef CONFIG_AUDITSYSCALL
4182 static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
4183                                          struct audit_buffer *audit_buf)
4184 {
4185         struct xfrm_sec_ctx *ctx = xp->security;
4186         struct xfrm_selector *sel = &xp->selector;
4187
4188         if (ctx)
4189                 audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
4190                                  ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str);
4191
4192         switch (sel->family) {
4193         case AF_INET:
4194                 audit_log_format(audit_buf, " src=%pI4", &sel->saddr.a4);
4195                 if (sel->prefixlen_s != 32)
4196                         audit_log_format(audit_buf, " src_prefixlen=%d",
4197                                          sel->prefixlen_s);
4198                 audit_log_format(audit_buf, " dst=%pI4", &sel->daddr.a4);
4199                 if (sel->prefixlen_d != 32)
4200                         audit_log_format(audit_buf, " dst_prefixlen=%d",
4201                                          sel->prefixlen_d);
4202                 break;
4203         case AF_INET6:
4204                 audit_log_format(audit_buf, " src=%pI6", sel->saddr.a6);
4205                 if (sel->prefixlen_s != 128)
4206                         audit_log_format(audit_buf, " src_prefixlen=%d",
4207                                          sel->prefixlen_s);
4208                 audit_log_format(audit_buf, " dst=%pI6", sel->daddr.a6);
4209                 if (sel->prefixlen_d != 128)
4210                         audit_log_format(audit_buf, " dst_prefixlen=%d",
4211                                          sel->prefixlen_d);
4212                 break;
4213         }
4214 }
4215
4216 void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid)
4217 {
4218         struct audit_buffer *audit_buf;
4219
4220         audit_buf = xfrm_audit_start("SPD-add");
4221         if (audit_buf == NULL)
4222                 return;
4223         xfrm_audit_helper_usrinfo(task_valid, audit_buf);
4224         audit_log_format(audit_buf, " res=%u", result);
4225         xfrm_audit_common_policyinfo(xp, audit_buf);
4226         audit_log_end(audit_buf);
4227 }
4228 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
4229
4230 void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
4231                               bool task_valid)
4232 {
4233         struct audit_buffer *audit_buf;
4234
4235         audit_buf = xfrm_audit_start("SPD-delete");
4236         if (audit_buf == NULL)
4237                 return;
4238         xfrm_audit_helper_usrinfo(task_valid, audit_buf);
4239         audit_log_format(audit_buf, " res=%u", result);
4240         xfrm_audit_common_policyinfo(xp, audit_buf);
4241         audit_log_end(audit_buf);
4242 }
4243 EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
4244 #endif
4245
4246 #ifdef CONFIG_XFRM_MIGRATE
4247 static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp,
4248                                         const struct xfrm_selector *sel_tgt)
4249 {
4250         if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
4251                 if (sel_tgt->family == sel_cmp->family &&
4252                     xfrm_addr_equal(&sel_tgt->daddr, &sel_cmp->daddr,
4253                                     sel_cmp->family) &&
4254                     xfrm_addr_equal(&sel_tgt->saddr, &sel_cmp->saddr,
4255                                     sel_cmp->family) &&
4256                     sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
4257                     sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
4258                         return true;
4259                 }
4260         } else {
4261                 if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
4262                         return true;
4263                 }
4264         }
4265         return false;
4266 }
4267
4268 static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector *sel,
4269                                                     u8 dir, u8 type, struct net *net, u32 if_id)
4270 {
4271         struct xfrm_policy *pol, *ret = NULL;
4272         struct hlist_head *chain;
4273         u32 priority = ~0U;
4274
4275         spin_lock_bh(&net->xfrm.xfrm_policy_lock);
4276         chain = policy_hash_direct(net, &sel->daddr, &sel->saddr, sel->family, dir);
4277         hlist_for_each_entry(pol, chain, bydst) {
4278                 if ((if_id == 0 || pol->if_id == if_id) &&
4279                     xfrm_migrate_selector_match(sel, &pol->selector) &&
4280                     pol->type == type) {
4281                         ret = pol;
4282                         priority = ret->priority;
4283                         break;
4284                 }
4285         }
4286         chain = &net->xfrm.policy_inexact[dir];
4287         hlist_for_each_entry(pol, chain, bydst_inexact_list) {
4288                 if ((pol->priority >= priority) && ret)
4289                         break;
4290
4291                 if ((if_id == 0 || pol->if_id == if_id) &&
4292                     xfrm_migrate_selector_match(sel, &pol->selector) &&
4293                     pol->type == type) {
4294                         ret = pol;
4295                         break;
4296                 }
4297         }
4298
4299         xfrm_pol_hold(ret);
4300
4301         spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
4302
4303         return ret;
4304 }
4305
4306 static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t)
4307 {
4308         int match = 0;
4309
4310         if (t->mode == m->mode && t->id.proto == m->proto &&
4311             (m->reqid == 0 || t->reqid == m->reqid)) {
4312                 switch (t->mode) {
4313                 case XFRM_MODE_TUNNEL:
4314                 case XFRM_MODE_BEET:
4315                         if (xfrm_addr_equal(&t->id.daddr, &m->old_daddr,
4316                                             m->old_family) &&
4317                             xfrm_addr_equal(&t->saddr, &m->old_saddr,
4318                                             m->old_family)) {
4319                                 match = 1;
4320                         }
4321                         break;
4322                 case XFRM_MODE_TRANSPORT:
4323                         /* in case of transport mode, template does not store
4324                            any IP addresses, hence we just compare mode and
4325                            protocol */
4326                         match = 1;
4327                         break;
4328                 default:
4329                         break;
4330                 }
4331         }
4332         return match;
4333 }
4334
4335 /* update endpoint address(es) of template(s) */
4336 static int xfrm_policy_migrate(struct xfrm_policy *pol,
4337                                struct xfrm_migrate *m, int num_migrate)
4338 {
4339         struct xfrm_migrate *mp;
4340         int i, j, n = 0;
4341
4342         write_lock_bh(&pol->lock);
4343         if (unlikely(pol->walk.dead)) {
4344                 /* target policy has been deleted */
4345                 write_unlock_bh(&pol->lock);
4346                 return -ENOENT;
4347         }
4348
4349         for (i = 0; i < pol->xfrm_nr; i++) {
4350                 for (j = 0, mp = m; j < num_migrate; j++, mp++) {
4351                         if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
4352                                 continue;
4353                         n++;
4354                         if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
4355                             pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
4356                                 continue;
4357                         /* update endpoints */
4358                         memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
4359                                sizeof(pol->xfrm_vec[i].id.daddr));
4360                         memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
4361                                sizeof(pol->xfrm_vec[i].saddr));
4362                         pol->xfrm_vec[i].encap_family = mp->new_family;
4363                         /* flush bundles */
4364                         atomic_inc(&pol->genid);
4365                 }
4366         }
4367
4368         write_unlock_bh(&pol->lock);
4369
4370         if (!n)
4371                 return -ENODATA;
4372
4373         return 0;
4374 }
4375
4376 static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate)
4377 {
4378         int i, j;
4379
4380         if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
4381                 return -EINVAL;
4382
4383         for (i = 0; i < num_migrate; i++) {
4384                 if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
4385                     xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
4386                         return -EINVAL;
4387
4388                 /* check if there is any duplicated entry */
4389                 for (j = i + 1; j < num_migrate; j++) {
4390                         if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
4391                                     sizeof(m[i].old_daddr)) &&
4392                             !memcmp(&m[i].old_saddr, &m[j].old_saddr,
4393                                     sizeof(m[i].old_saddr)) &&
4394                             m[i].proto == m[j].proto &&
4395                             m[i].mode == m[j].mode &&
4396                             m[i].reqid == m[j].reqid &&
4397                             m[i].old_family == m[j].old_family)
4398                                 return -EINVAL;
4399                 }
4400         }
4401
4402         return 0;
4403 }
4404
4405 int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
4406                  struct xfrm_migrate *m, int num_migrate,
4407                  struct xfrm_kmaddress *k, struct net *net,
4408                  struct xfrm_encap_tmpl *encap, u32 if_id)
4409 {
4410         int i, err, nx_cur = 0, nx_new = 0;
4411         struct xfrm_policy *pol = NULL;
4412         struct xfrm_state *x, *xc;
4413         struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
4414         struct xfrm_state *x_new[XFRM_MAX_DEPTH];
4415         struct xfrm_migrate *mp;
4416
4417         /* Stage 0 - sanity checks */
4418         if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
4419                 goto out;
4420
4421         if (dir >= XFRM_POLICY_MAX) {
4422                 err = -EINVAL;
4423                 goto out;
4424         }
4425
4426         /* Stage 1 - find policy */
4427         if ((pol = xfrm_migrate_policy_find(sel, dir, type, net, if_id)) == NULL) {
4428                 err = -ENOENT;
4429                 goto out;
4430         }
4431
4432         /* Stage 2 - find and update state(s) */
4433         for (i = 0, mp = m; i < num_migrate; i++, mp++) {
4434                 if ((x = xfrm_migrate_state_find(mp, net, if_id))) {
4435                         x_cur[nx_cur] = x;
4436                         nx_cur++;
4437                         xc = xfrm_state_migrate(x, mp, encap);
4438                         if (xc) {
4439                                 x_new[nx_new] = xc;
4440                                 nx_new++;
4441                         } else {
4442                                 err = -ENODATA;
4443                                 goto restore_state;
4444                         }
4445                 }
4446         }
4447
4448         /* Stage 3 - update policy */
4449         if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
4450                 goto restore_state;
4451
4452         /* Stage 4 - delete old state(s) */
4453         if (nx_cur) {
4454                 xfrm_states_put(x_cur, nx_cur);
4455                 xfrm_states_delete(x_cur, nx_cur);
4456         }
4457
4458         /* Stage 5 - announce */
4459         km_migrate(sel, dir, type, m, num_migrate, k, encap);
4460
4461         xfrm_pol_put(pol);
4462
4463         return 0;
4464 out:
4465         return err;
4466
4467 restore_state:
4468         if (pol)
4469                 xfrm_pol_put(pol);
4470         if (nx_cur)
4471                 xfrm_states_put(x_cur, nx_cur);
4472         if (nx_new)
4473                 xfrm_states_delete(x_new, nx_new);
4474
4475         return err;
4476 }
4477 EXPORT_SYMBOL(xfrm_migrate);
4478 #endif