net/xfrm/xfrm_policy.c

   1 /*
   2  * xfrm_policy.c
   3  *
   4  * Changes:
   5  *      Mitsuru KANDA @USAGI
   6  *      Kazunori MIYAZAWA @USAGI
   7  *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
   8  *              IPv6 support
   9  *      Kazunori MIYAZAWA @USAGI
  10  *      YOSHIFUJI Hideaki
  11  *              Split up af-specific portion
  12  *      Derek Atkins <derek@ihtfp.com>          Add the post_input processor
  13  *
  14  */
  15
  16 #include <linux/err.h>
  17 #include <linux/slab.h>
  18 #include <linux/kmod.h>
  19 #include <linux/list.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/workqueue.h>
  22 #include <linux/notifier.h>
  23 #include <linux/netdevice.h>
  24 #include <linux/netfilter.h>
  25 #include <linux/module.h>
  26 #include <linux/cache.h>
  27 #include <linux/audit.h>
  28 #include <net/dst.h>
  29 #include <net/flow.h>
  30 #include <net/xfrm.h>
  31 #include <net/ip.h>
  32 #ifdef CONFIG_XFRM_STATISTICS
  33 #include <net/snmp.h>
  34 #endif
  35
  36 #include "xfrm_hash.h"
  37
  38 DEFINE_MUTEX(xfrm_cfg_mutex);
  39 EXPORT_SYMBOL(xfrm_cfg_mutex);
  40
  41 static DEFINE_SPINLOCK(xfrm_policy_sk_bundle_lock);
  42 static struct dst_entry *xfrm_policy_sk_bundles;
  43 static DEFINE_RWLOCK(xfrm_policy_lock);
  44
  45 static DEFINE_RWLOCK(xfrm_policy_afinfo_lock);
  46 static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO];
  47
  48 static struct kmem_cache *xfrm_dst_cache __read_mostly;
  49
  50 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family);
  51 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);
  52 static void xfrm_init_pmtu(struct dst_entry *dst);
  53 static int stale_bundle(struct dst_entry *dst);
  54 static int xfrm_bundle_ok(struct xfrm_dst *xdst);
  55
  56
  57 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
  58                                                 int dir);
  59
  60 static inline bool
  61 __xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
  62 {
  63         const struct flowi4 *fl4 = &fl->u.ip4;
  64
  65         return  addr4_match(fl4->daddr, sel->daddr.a4, sel->prefixlen_d) &&
  66                 addr4_match(fl4->saddr, sel->saddr.a4, sel->prefixlen_s) &&
  67                 !((xfrm_flowi_dport(fl, &fl4->uli) ^ sel->dport) & sel->dport_mask) &&
  68                 !((xfrm_flowi_sport(fl, &fl4->uli) ^ sel->sport) & sel->sport_mask) &&
  69                 (fl4->flowi4_proto == sel->proto || !sel->proto) &&
  70                 (fl4->flowi4_oif == sel->ifindex || !sel->ifindex);
  71 }
  72
  73 static inline bool
  74 __xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
  75 {
  76         const struct flowi6 *fl6 = &fl->u.ip6;
  77
  78         return  addr_match(&fl6->daddr, &sel->daddr, sel->prefixlen_d) &&
  79                 addr_match(&fl6->saddr, &sel->saddr, sel->prefixlen_s) &&
  80                 !((xfrm_flowi_dport(fl, &fl6->uli) ^ sel->dport) & sel->dport_mask) &&
  81                 !((xfrm_flowi_sport(fl, &fl6->uli) ^ sel->sport) & sel->sport_mask) &&
  82                 (fl6->flowi6_proto == sel->proto || !sel->proto) &&
  83                 (fl6->flowi6_oif == sel->ifindex || !sel->ifindex);
  84 }
  85
  86 bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl,
  87                          unsigned short family)
  88 {
  89         switch (family) {
  90         case AF_INET:
  91                 return __xfrm4_selector_match(sel, fl);
  92         case AF_INET6:
  93                 return __xfrm6_selector_match(sel, fl);
  94         }
  95         return false;
  96 }
  97
  98 static inline struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos,
  99                                                   const xfrm_address_t *saddr,
 100                                                   const xfrm_address_t *daddr,
 101                                                   int family)
 102 {
 103         struct xfrm_policy_afinfo *afinfo;
 104         struct dst_entry *dst;
 105
 106         afinfo = xfrm_policy_get_afinfo(family);
 107         if (unlikely(afinfo == NULL))
 108                 return ERR_PTR(-EAFNOSUPPORT);
 109
 110         dst = afinfo->dst_lookup(net, tos, saddr, daddr);
 111
 112         xfrm_policy_put_afinfo(afinfo);
 113
 114         return dst;
 115 }
 116
 117 static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x, int tos,
 118                                                 xfrm_address_t *prev_saddr,
 119                                                 xfrm_address_t *prev_daddr,
 120                                                 int family)
 121 {
 122         struct net *net = xs_net(x);
 123         xfrm_address_t *saddr = &x->props.saddr;
 124         xfrm_address_t *daddr = &x->id.daddr;
 125         struct dst_entry *dst;
 126
 127         if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) {
 128                 saddr = x->coaddr;
 129                 daddr = prev_daddr;
 130         }
 131         if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) {
 132                 saddr = prev_saddr;
 133                 daddr = x->coaddr;
 134         }
 135
 136         dst = __xfrm_dst_lookup(net, tos, saddr, daddr, family);
 137
 138         if (!IS_ERR(dst)) {
 139                 if (prev_saddr != saddr)
 140                         memcpy(prev_saddr, saddr,  sizeof(*prev_saddr));
 141                 if (prev_daddr != daddr)
 142                         memcpy(prev_daddr, daddr,  sizeof(*prev_daddr));
 143         }
 144
 145         return dst;
 146 }
 147
 148 static inline unsigned long make_jiffies(long secs)
 149 {
 150         if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
 151                 return MAX_SCHEDULE_TIMEOUT-1;
 152         else
 153                 return secs*HZ;
 154 }
 155
 156 static void xfrm_policy_timer(unsigned long data)
 157 {
 158         struct xfrm_policy *xp = (struct xfrm_policy*)data;
 159         unsigned long now = get_seconds();
 160         long next = LONG_MAX;
 161         int warn = 0;
 162         int dir;
 163
 164         read_lock(&xp->lock);
 165
 166         if (unlikely(xp->walk.dead))
 167                 goto out;
 168
 169         dir = xfrm_policy_id2dir(xp->index);
 170
 171         if (xp->lft.hard_add_expires_seconds) {
 172                 long tmo = xp->lft.hard_add_expires_seconds +
 173                         xp->curlft.add_time - now;
 174                 if (tmo <= 0)
 175                         goto expired;
 176                 if (tmo < next)
 177                         next = tmo;
 178         }
 179         if (xp->lft.hard_use_expires_seconds) {
 180                 long tmo = xp->lft.hard_use_expires_seconds +
 181                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 182                 if (tmo <= 0)
 183                         goto expired;
 184                 if (tmo < next)
 185                         next = tmo;
 186         }
 187         if (xp->lft.soft_add_expires_seconds) {
 188                 long tmo = xp->lft.soft_add_expires_seconds +
 189                         xp->curlft.add_time - now;
 190                 if (tmo <= 0) {
 191                         warn = 1;
 192                         tmo = XFRM_KM_TIMEOUT;
 193                 }
 194                 if (tmo < next)
 195                         next = tmo;
 196         }
 197         if (xp->lft.soft_use_expires_seconds) {
 198                 long tmo = xp->lft.soft_use_expires_seconds +
 199                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 200                 if (tmo <= 0) {
 201                         warn = 1;
 202                         tmo = XFRM_KM_TIMEOUT;
 203                 }
 204                 if (tmo < next)
 205                         next = tmo;
 206         }
 207
 208         if (warn)
 209                 km_policy_expired(xp, dir, 0, 0);
 210         if (next != LONG_MAX &&
 211             !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
 212                 xfrm_pol_hold(xp);
 213
 214 out:
 215         read_unlock(&xp->lock);
 216         xfrm_pol_put(xp);
 217         return;
 218
 219 expired:
 220         read_unlock(&xp->lock);
 221         if (!xfrm_policy_delete(xp, dir))
 222                 km_policy_expired(xp, dir, 1, 0);
 223         xfrm_pol_put(xp);
 224 }
 225
 226 static struct flow_cache_object *xfrm_policy_flo_get(struct flow_cache_object *flo)
 227 {
 228         struct xfrm_policy *pol = container_of(flo, struct xfrm_policy, flo);
 229
 230         if (unlikely(pol->walk.dead))
 231                 flo = NULL;
 232         else
 233                 xfrm_pol_hold(pol);
 234
 235         return flo;
 236 }
 237
 238 static int xfrm_policy_flo_check(struct flow_cache_object *flo)
 239 {
 240         struct xfrm_policy *pol = container_of(flo, struct xfrm_policy, flo);
 241
 242         return !pol->walk.dead;
 243 }
 244
 245 static void xfrm_policy_flo_delete(struct flow_cache_object *flo)
 246 {
 247         xfrm_pol_put(container_of(flo, struct xfrm_policy, flo));
 248 }
 249
 250 static const struct flow_cache_ops xfrm_policy_fc_ops = {
 251         .get = xfrm_policy_flo_get,
 252         .check = xfrm_policy_flo_check,
 253         .delete = xfrm_policy_flo_delete,
 254 };
 255
 256 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
 257  * SPD calls.
 258  */
 259
 260 struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
 261 {
 262         struct xfrm_policy *policy;
 263
 264         policy = kzalloc(sizeof(struct xfrm_policy), gfp);
 265
 266         if (policy) {
 267                 write_pnet(&policy->xp_net, net);
 268                 INIT_LIST_HEAD(&policy->walk.all);
 269                 INIT_HLIST_NODE(&policy->bydst);
 270                 INIT_HLIST_NODE(&policy->byidx);
 271                 rwlock_init(&policy->lock);
 272                 atomic_set(&policy->refcnt, 1);
 273                 setup_timer(&policy->timer, xfrm_policy_timer,
 274                                 (unsigned long)policy);
 275                 policy->flo.ops = &xfrm_policy_fc_ops;
 276         }
 277         return policy;
 278 }
 279 EXPORT_SYMBOL(xfrm_policy_alloc);
 280
 281 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
 282
 283 void xfrm_policy_destroy(struct xfrm_policy *policy)
 284 {
 285         BUG_ON(!policy->walk.dead);
 286
 287         if (del_timer(&policy->timer))
 288                 BUG();
 289
 290         security_xfrm_policy_free(policy->security);
 291         kfree(policy);
 292 }
 293 EXPORT_SYMBOL(xfrm_policy_destroy);
 294
 295 /* Rule must be locked. Release descentant resources, announce
 296  * entry dead. The rule must be unlinked from lists to the moment.
 297  */
 298
 299 static void xfrm_policy_kill(struct xfrm_policy *policy)
 300 {
 301         policy->walk.dead = 1;
 302
 303         atomic_inc(&policy->genid);
 304
 305         if (del_timer(&policy->timer))
 306                 xfrm_pol_put(policy);
 307
 308         xfrm_pol_put(policy);
 309 }
 310
 311 static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
 312
 313 static inline unsigned int idx_hash(struct net *net, u32 index)
 314 {
 315         return __idx_hash(index, net->xfrm.policy_idx_hmask);
 316 }
 317
 318 static struct hlist_head *policy_hash_bysel(struct net *net,
 319                                             const struct xfrm_selector *sel,
 320                                             unsigned short family, int dir)
 321 {
 322         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 323         unsigned int hash = __sel_hash(sel, family, hmask);
 324
 325         return (hash == hmask + 1 ?
 326                 &net->xfrm.policy_inexact[dir] :
 327                 net->xfrm.policy_bydst[dir].table + hash);
 328 }
 329
 330 static struct hlist_head *policy_hash_direct(struct net *net,
 331                                              const xfrm_address_t *daddr,
 332                                              const xfrm_address_t *saddr,
 333                                              unsigned short family, int dir)
 334 {
 335         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 336         unsigned int hash = __addr_hash(daddr, saddr, family, hmask);
 337
 338         return net->xfrm.policy_bydst[dir].table + hash;
 339 }
 340
 341 static void xfrm_dst_hash_transfer(struct hlist_head *list,
 342                                    struct hlist_head *ndsttable,
 343                                    unsigned int nhashmask)
 344 {
 345         struct hlist_node *entry, *tmp, *entry0 = NULL;
 346         struct xfrm_policy *pol;
 347         unsigned int h0 = 0;
 348
 349 redo:
 350         hlist_for_each_entry_safe(pol, entry, tmp, list, bydst) {
 351                 unsigned int h;
 352
 353                 h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
 354                                 pol->family, nhashmask);
 355                 if (!entry0) {
 356                         hlist_del(entry);
 357                         hlist_add_head(&pol->bydst, ndsttable+h);
 358                         h0 = h;
 359                 } else {
 360                         if (h != h0)
 361                                 continue;
 362                         hlist_del(entry);
 363                         hlist_add_after(entry0, &pol->bydst);
 364                 }
 365                 entry0 = entry;
 366         }
 367         if (!hlist_empty(list)) {
 368                 entry0 = NULL;
 369                 goto redo;
 370         }
 371 }
 372
 373 static void xfrm_idx_hash_transfer(struct hlist_head *list,
 374                                    struct hlist_head *nidxtable,
 375                                    unsigned int nhashmask)
 376 {
 377         struct hlist_node *entry, *tmp;
 378         struct xfrm_policy *pol;
 379
 380         hlist_for_each_entry_safe(pol, entry, tmp, list, byidx) {
 381                 unsigned int h;
 382
 383                 h = __idx_hash(pol->index, nhashmask);
 384                 hlist_add_head(&pol->byidx, nidxtable+h);
 385         }
 386 }
 387
 388 static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
 389 {
 390         return ((old_hmask + 1) << 1) - 1;
 391 }
 392
 393 static void xfrm_bydst_resize(struct net *net, int dir)
 394 {
 395         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 396         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 397         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 398         struct hlist_head *odst = net->xfrm.policy_bydst[dir].table;
 399         struct hlist_head *ndst = xfrm_hash_alloc(nsize);
 400         int i;
 401
 402         if (!ndst)
 403                 return;
 404
 405         write_lock_bh(&xfrm_policy_lock);
 406
 407         for (i = hmask; i >= 0; i--)
 408                 xfrm_dst_hash_transfer(odst + i, ndst, nhashmask);
 409
 410         net->xfrm.policy_bydst[dir].table = ndst;
 411         net->xfrm.policy_bydst[dir].hmask = nhashmask;
 412
 413         write_unlock_bh(&xfrm_policy_lock);
 414
 415         xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
 416 }
 417
 418 static void xfrm_byidx_resize(struct net *net, int total)
 419 {
 420         unsigned int hmask = net->xfrm.policy_idx_hmask;
 421         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 422         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 423         struct hlist_head *oidx = net->xfrm.policy_byidx;
 424         struct hlist_head *nidx = xfrm_hash_alloc(nsize);
 425         int i;
 426
 427         if (!nidx)
 428                 return;
 429
 430         write_lock_bh(&xfrm_policy_lock);
 431
 432         for (i = hmask; i >= 0; i--)
 433                 xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
 434
 435         net->xfrm.policy_byidx = nidx;
 436         net->xfrm.policy_idx_hmask = nhashmask;
 437
 438         write_unlock_bh(&xfrm_policy_lock);
 439
 440         xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
 441 }
 442
 443 static inline int xfrm_bydst_should_resize(struct net *net, int dir, int *total)
 444 {
 445         unsigned int cnt = net->xfrm.policy_count[dir];
 446         unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 447
 448         if (total)
 449                 *total += cnt;
 450
 451         if ((hmask + 1) < xfrm_policy_hashmax &&
 452             cnt > hmask)
 453                 return 1;
 454
 455         return 0;
 456 }
 457
 458 static inline int xfrm_byidx_should_resize(struct net *net, int total)
 459 {
 460         unsigned int hmask = net->xfrm.policy_idx_hmask;
 461
 462         if ((hmask + 1) < xfrm_policy_hashmax &&
 463             total > hmask)
 464                 return 1;
 465
 466         return 0;
 467 }
 468
 469 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
 470 {
 471         read_lock_bh(&xfrm_policy_lock);
 472         si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
 473         si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
 474         si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
 475         si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
 476         si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
 477         si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
 478         si->spdhcnt = net->xfrm.policy_idx_hmask;
 479         si->spdhmcnt = xfrm_policy_hashmax;
 480         read_unlock_bh(&xfrm_policy_lock);
 481 }
 482 EXPORT_SYMBOL(xfrm_spd_getinfo);
 483
 484 static DEFINE_MUTEX(hash_resize_mutex);
 485 static void xfrm_hash_resize(struct work_struct *work)
 486 {
 487         struct net *net = container_of(work, struct net, xfrm.policy_hash_work);
 488         int dir, total;
 489
 490         mutex_lock(&hash_resize_mutex);
 491
 492         total = 0;
 493         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
 494                 if (xfrm_bydst_should_resize(net, dir, &total))
 495                         xfrm_bydst_resize(net, dir);
 496         }
 497         if (xfrm_byidx_should_resize(net, total))
 498                 xfrm_byidx_resize(net, total);
 499
 500         mutex_unlock(&hash_resize_mutex);
 501 }
 502
 503 /* Generate new index... KAME seems to generate them ordered by cost
 504  * of an absolute inpredictability of ordering of rules. This will not pass. */
 505 static u32 xfrm_gen_index(struct net *net, int dir)
 506 {
 507         static u32 idx_generator;
 508
 509         for (;;) {
 510                 struct hlist_node *entry;
 511                 struct hlist_head *list;
 512                 struct xfrm_policy *p;
 513                 u32 idx;
 514                 int found;
 515
 516                 idx = (idx_generator | dir);
 517                 idx_generator += 8;
 518                 if (idx == 0)
 519                         idx = 8;
 520                 list = net->xfrm.policy_byidx + idx_hash(net, idx);
 521                 found = 0;
 522                 hlist_for_each_entry(p, entry, list, byidx) {
 523                         if (p->index == idx) {
 524                                 found = 1;
 525                                 break;
 526                         }
 527                 }
 528                 if (!found)
 529                         return idx;
 530         }
 531 }
 532
 533 static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
 534 {
 535         u32 *p1 = (u32 *) s1;
 536         u32 *p2 = (u32 *) s2;
 537         int len = sizeof(struct xfrm_selector) / sizeof(u32);
 538         int i;
 539
 540         for (i = 0; i < len; i++) {
 541                 if (p1[i] != p2[i])
 542                         return 1;
 543         }
 544
 545         return 0;
 546 }
 547
 548 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 549 {
 550         struct net *net = xp_net(policy);
 551         struct xfrm_policy *pol;
 552         struct xfrm_policy *delpol;
 553         struct hlist_head *chain;
 554         struct hlist_node *entry, *newpos;
 555         u32 mark = policy->mark.v & policy->mark.m;
 556
 557         write_lock_bh(&xfrm_policy_lock);
 558         chain = policy_hash_bysel(net, &policy->selector, policy->family, dir);
 559         delpol = NULL;
 560         newpos = NULL;
 561         hlist_for_each_entry(pol, entry, chain, bydst) {
 562                 if (pol->type == policy->type &&
 563                     !selector_cmp(&pol->selector, &policy->selector) &&
 564                     (mark & pol->mark.m) == pol->mark.v &&
 565                     xfrm_sec_ctx_match(pol->security, policy->security) &&
 566                     !WARN_ON(delpol)) {
 567                         if (excl) {
 568                                 write_unlock_bh(&xfrm_policy_lock);
 569                                 return -EEXIST;
 570                         }
 571                         delpol = pol;
 572                         if (policy->priority > pol->priority)
 573                                 continue;
 574                 } else if (policy->priority >= pol->priority) {
 575                         newpos = &pol->bydst;
 576                         continue;
 577                 }
 578                 if (delpol)
 579                         break;
 580         }
 581         if (newpos)
 582                 hlist_add_after(newpos, &policy->bydst);
 583         else
 584                 hlist_add_head(&policy->bydst, chain);
 585         xfrm_pol_hold(policy);
 586         net->xfrm.policy_count[dir]++;
 587         atomic_inc(&flow_cache_genid);
 588         rt_genid_bump(net);
 589         if (delpol)
 590                 __xfrm_policy_unlink(delpol, dir);
 591         policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir);
 592         hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index));
 593         policy->curlft.add_time = get_seconds();
 594         policy->curlft.use_time = 0;
 595         if (!mod_timer(&policy->timer, jiffies + HZ))
 596                 xfrm_pol_hold(policy);
 597         list_add(&policy->walk.all, &net->xfrm.policy_all);
 598         write_unlock_bh(&xfrm_policy_lock);
 599
 600         if (delpol)
 601                 xfrm_policy_kill(delpol);
 602         else if (xfrm_bydst_should_resize(net, dir, NULL))
 603                 schedule_work(&net->xfrm.policy_hash_work);
 604
 605         return 0;
 606 }
 607 EXPORT_SYMBOL(xfrm_policy_insert);
 608
 609 struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u8 type,
 610                                           int dir, struct xfrm_selector *sel,
 611                                           struct xfrm_sec_ctx *ctx, int delete,
 612                                           int *err)
 613 {
 614         struct xfrm_policy *pol, *ret;
 615         struct hlist_head *chain;
 616         struct hlist_node *entry;
 617
 618         *err = 0;
 619         write_lock_bh(&xfrm_policy_lock);
 620         chain = policy_hash_bysel(net, sel, sel->family, dir);
 621         ret = NULL;
 622         hlist_for_each_entry(pol, entry, chain, bydst) {
 623                 if (pol->type == type &&
 624                     (mark & pol->mark.m) == pol->mark.v &&
 625                     !selector_cmp(sel, &pol->selector) &&
 626                     xfrm_sec_ctx_match(ctx, pol->security)) {
 627                         xfrm_pol_hold(pol);
 628                         if (delete) {
 629                                 *err = security_xfrm_policy_delete(
 630                                                                 pol->security);
 631                                 if (*err) {
 632                                         write_unlock_bh(&xfrm_policy_lock);
 633                                         return pol;
 634                                 }
 635                                 __xfrm_policy_unlink(pol, dir);
 636                         }
 637                         ret = pol;
 638                         break;
 639                 }
 640         }
 641         write_unlock_bh(&xfrm_policy_lock);
 642
 643         if (ret && delete)
 644                 xfrm_policy_kill(ret);
 645         return ret;
 646 }
 647 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
 648
 649 struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8 type,
 650                                      int dir, u32 id, int delete, int *err)
 651 {
 652         struct xfrm_policy *pol, *ret;
 653         struct hlist_head *chain;
 654         struct hlist_node *entry;
 655
 656         *err = -ENOENT;
 657         if (xfrm_policy_id2dir(id) != dir)
 658                 return NULL;
 659
 660         *err = 0;
 661         write_lock_bh(&xfrm_policy_lock);
 662         chain = net->xfrm.policy_byidx + idx_hash(net, id);
 663         ret = NULL;
 664         hlist_for_each_entry(pol, entry, chain, byidx) {
 665                 if (pol->type == type && pol->index == id &&
 666                     (mark & pol->mark.m) == pol->mark.v) {
 667                         xfrm_pol_hold(pol);
 668                         if (delete) {
 669                                 *err = security_xfrm_policy_delete(
 670                                                                 pol->security);
 671                                 if (*err) {
 672                                         write_unlock_bh(&xfrm_policy_lock);
 673                                         return pol;
 674                                 }
 675                                 __xfrm_policy_unlink(pol, dir);
 676                         }
 677                         ret = pol;
 678                         break;
 679                 }
 680         }
 681         write_unlock_bh(&xfrm_policy_lock);
 682
 683         if (ret && delete)
 684                 xfrm_policy_kill(ret);
 685         return ret;
 686 }
 687 EXPORT_SYMBOL(xfrm_policy_byid);
 688
 689 #ifdef CONFIG_SECURITY_NETWORK_XFRM
 690 static inline int
 691 xfrm_policy_flush_secctx_check(struct net *net, u8 type, struct xfrm_audit *audit_info)
 692 {
 693         int dir, err = 0;
 694
 695         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 696                 struct xfrm_policy *pol;
 697                 struct hlist_node *entry;
 698                 int i;
 699
 700                 hlist_for_each_entry(pol, entry,
 701                                      &net->xfrm.policy_inexact[dir], bydst) {
 702                         if (pol->type != type)
 703                                 continue;
 704                         err = security_xfrm_policy_delete(pol->security);
 705                         if (err) {
 706                                 xfrm_audit_policy_delete(pol, 0,
 707                                                          audit_info->loginuid,
 708                                                          audit_info->sessionid,
 709                                                          audit_info->secid);
 710                                 return err;
 711                         }
 712                 }
 713                 for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
 714                         hlist_for_each_entry(pol, entry,
 715                                              net->xfrm.policy_bydst[dir].table + i,
 716                                              bydst) {
 717                                 if (pol->type != type)
 718                                         continue;
 719                                 err = security_xfrm_policy_delete(
 720                                                                 pol->security);
 721                                 if (err) {
 722                                         xfrm_audit_policy_delete(pol, 0,
 723                                                         audit_info->loginuid,
 724                                                         audit_info->sessionid,
 725                                                         audit_info->secid);
 726                                         return err;
 727                                 }
 728                         }
 729                 }
 730         }
 731         return err;
 732 }
 733 #else
 734 static inline int
 735 xfrm_policy_flush_secctx_check(struct net *net, u8 type, struct xfrm_audit *audit_info)
 736 {
 737         return 0;
 738 }
 739 #endif
 740
 741 int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info)
 742 {
 743         int dir, err = 0, cnt = 0;
 744
 745         write_lock_bh(&xfrm_policy_lock);
 746
 747         err = xfrm_policy_flush_secctx_check(net, type, audit_info);
 748         if (err)
 749                 goto out;
 750
 751         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 752                 struct xfrm_policy *pol;
 753                 struct hlist_node *entry;
 754                 int i;
 755
 756         again1:
 757                 hlist_for_each_entry(pol, entry,
 758                                      &net->xfrm.policy_inexact[dir], bydst) {
 759                         if (pol->type != type)
 760                                 continue;
 761                         __xfrm_policy_unlink(pol, dir);
 762                         write_unlock_bh(&xfrm_policy_lock);
 763                         cnt++;
 764
 765                         xfrm_audit_policy_delete(pol, 1, audit_info->loginuid,
 766                                                  audit_info->sessionid,
 767                                                  audit_info->secid);
 768
 769                         xfrm_policy_kill(pol);
 770
 771                         write_lock_bh(&xfrm_policy_lock);
 772                         goto again1;
 773                 }
 774
 775                 for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) {
 776         again2:
 777                         hlist_for_each_entry(pol, entry,
 778                                              net->xfrm.policy_bydst[dir].table + i,
 779                                              bydst) {
 780                                 if (pol->type != type)
 781                                         continue;
 782                                 __xfrm_policy_unlink(pol, dir);
 783                                 write_unlock_bh(&xfrm_policy_lock);
 784                                 cnt++;
 785
 786                                 xfrm_audit_policy_delete(pol, 1,
 787                                                          audit_info->loginuid,
 788                                                          audit_info->sessionid,
 789                                                          audit_info->secid);
 790                                 xfrm_policy_kill(pol);
 791
 792                                 write_lock_bh(&xfrm_policy_lock);
 793                                 goto again2;
 794                         }
 795                 }
 796
 797         }
 798         if (!cnt)
 799                 err = -ESRCH;
 800 out:
 801         write_unlock_bh(&xfrm_policy_lock);
 802         return err;
 803 }
 804 EXPORT_SYMBOL(xfrm_policy_flush);
 805
 806 int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
 807                      int (*func)(struct xfrm_policy *, int, int, void*),
 808                      void *data)
 809 {
 810         struct xfrm_policy *pol;
 811         struct xfrm_policy_walk_entry *x;
 812         int error = 0;
 813
 814         if (walk->type >= XFRM_POLICY_TYPE_MAX &&
 815             walk->type != XFRM_POLICY_TYPE_ANY)
 816                 return -EINVAL;
 817
 818         if (list_empty(&walk->walk.all) && walk->seq != 0)
 819                 return 0;
 820
 821         write_lock_bh(&xfrm_policy_lock);
 822         if (list_empty(&walk->walk.all))
 823                 x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
 824         else
 825                 x = list_entry(&walk->walk.all, struct xfrm_policy_walk_entry, all);
 826         list_for_each_entry_from(x, &net->xfrm.policy_all, all) {
 827                 if (x->dead)
 828                         continue;
 829                 pol = container_of(x, struct xfrm_policy, walk);
 830                 if (walk->type != XFRM_POLICY_TYPE_ANY &&
 831                     walk->type != pol->type)
 832                         continue;
 833                 error = func(pol, xfrm_policy_id2dir(pol->index),
 834                              walk->seq, data);
 835                 if (error) {
 836                         list_move_tail(&walk->walk.all, &x->all);
 837                         goto out;
 838                 }
 839                 walk->seq++;
 840         }
 841         if (walk->seq == 0) {
 842                 error = -ENOENT;
 843                 goto out;
 844         }
 845         list_del_init(&walk->walk.all);
 846 out:
 847         write_unlock_bh(&xfrm_policy_lock);
 848         return error;
 849 }
 850 EXPORT_SYMBOL(xfrm_policy_walk);
 851
 852 void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type)
 853 {
 854         INIT_LIST_HEAD(&walk->walk.all);
 855         walk->walk.dead = 1;
 856         walk->type = type;
 857         walk->seq = 0;
 858 }
 859 EXPORT_SYMBOL(xfrm_policy_walk_init);
 860
 861 void xfrm_policy_walk_done(struct xfrm_policy_walk *walk)
 862 {
 863         if (list_empty(&walk->walk.all))
 864                 return;
 865
 866         write_lock_bh(&xfrm_policy_lock);
 867         list_del(&walk->walk.all);
 868         write_unlock_bh(&xfrm_policy_lock);
 869 }
 870 EXPORT_SYMBOL(xfrm_policy_walk_done);
 871
 872 /*
 873  * Find policy to apply to this flow.
 874  *
 875  * Returns 0 if policy found, else an -errno.
 876  */
 877 static int xfrm_policy_match(const struct xfrm_policy *pol,
 878                              const struct flowi *fl,
 879                              u8 type, u16 family, int dir)
 880 {
 881         const struct xfrm_selector *sel = &pol->selector;
 882         int ret = -ESRCH;
 883         bool match;
 884
 885         if (pol->family != family ||
 886             (fl->flowi_mark & pol->mark.m) != pol->mark.v ||
 887             pol->type != type)
 888                 return ret;
 889
 890         match = xfrm_selector_match(sel, fl, family);
 891         if (match)
 892                 ret = security_xfrm_policy_lookup(pol->security, fl->flowi_secid,
 893                                                   dir);
 894
 895         return ret;
 896 }
 897
 898 static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
 899                                                      const struct flowi *fl,
 900                                                      u16 family, u8 dir)
 901 {
 902         int err;
 903         struct xfrm_policy *pol, *ret;
 904         const xfrm_address_t *daddr, *saddr;
 905         struct hlist_node *entry;
 906         struct hlist_head *chain;
 907         u32 priority = ~0U;
 908
 909         daddr = xfrm_flowi_daddr(fl, family);
 910         saddr = xfrm_flowi_saddr(fl, family);
 911         if (unlikely(!daddr || !saddr))
 912                 return NULL;
 913
 914         read_lock_bh(&xfrm_policy_lock);
 915         chain = policy_hash_direct(net, daddr, saddr, family, dir);
 916         ret = NULL;
 917         hlist_for_each_entry(pol, entry, chain, bydst) {
 918                 err = xfrm_policy_match(pol, fl, type, family, dir);
 919                 if (err) {
 920                         if (err == -ESRCH)
 921                                 continue;
 922                         else {
 923                                 ret = ERR_PTR(err);
 924                                 goto fail;
 925                         }
 926                 } else {
 927                         ret = pol;
 928                         priority = ret->priority;
 929                         break;
 930                 }
 931         }
 932         chain = &net->xfrm.policy_inexact[dir];
 933         hlist_for_each_entry(pol, entry, chain, bydst) {
 934                 err = xfrm_policy_match(pol, fl, type, family, dir);
 935                 if (err) {
 936                         if (err == -ESRCH)
 937                                 continue;
 938                         else {
 939                                 ret = ERR_PTR(err);
 940                                 goto fail;
 941                         }
 942                 } else if (pol->priority < priority) {
 943                         ret = pol;
 944                         break;
 945                 }
 946         }
 947         if (ret)
 948                 xfrm_pol_hold(ret);
 949 fail:
 950         read_unlock_bh(&xfrm_policy_lock);
 951
 952         return ret;
 953 }
 954
 955 static struct xfrm_policy *
 956 __xfrm_policy_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir)
 957 {
 958 #ifdef CONFIG_XFRM_SUB_POLICY
 959         struct xfrm_policy *pol;
 960
 961         pol = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_SUB, fl, family, dir);
 962         if (pol != NULL)
 963                 return pol;
 964 #endif
 965         return xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, fl, family, dir);
 966 }
 967
 968 static struct flow_cache_object *
 969 xfrm_policy_lookup(struct net *net, const struct flowi *fl, u16 family,
 970                    u8 dir, struct flow_cache_object *old_obj, void *ctx)
 971 {
 972         struct xfrm_policy *pol;
 973
 974         if (old_obj)
 975                 xfrm_pol_put(container_of(old_obj, struct xfrm_policy, flo));
 976
 977         pol = __xfrm_policy_lookup(net, fl, family, dir);
 978         if (IS_ERR_OR_NULL(pol))
 979                 return ERR_CAST(pol);
 980
 981         /* Resolver returns two references:
 982          * one for cache and one for caller of flow_cache_lookup() */
 983         xfrm_pol_hold(pol);
 984
 985         return &pol->flo;
 986 }
 987
 988 static inline int policy_to_flow_dir(int dir)
 989 {
 990         if (XFRM_POLICY_IN == FLOW_DIR_IN &&
 991             XFRM_POLICY_OUT == FLOW_DIR_OUT &&
 992             XFRM_POLICY_FWD == FLOW_DIR_FWD)
 993                 return dir;
 994         switch (dir) {
 995         default:
 996         case XFRM_POLICY_IN:
 997                 return FLOW_DIR_IN;
 998         case XFRM_POLICY_OUT:
 999                 return FLOW_DIR_OUT;
1000         case XFRM_POLICY_FWD:
1001                 return FLOW_DIR_FWD;
1002         }
1003 }
1004
1005 static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir,
1006                                                  const struct flowi *fl)
1007 {
1008         struct xfrm_policy *pol;
1009
1010         read_lock_bh(&xfrm_policy_lock);
1011         if ((pol = sk->sk_policy[dir]) != NULL) {
1012                 bool match = xfrm_selector_match(&pol->selector, fl,
1013                                                  sk->sk_family);
1014                 int err = 0;
1015
1016                 if (match) {
1017                         if ((sk->sk_mark & pol->mark.m) != pol->mark.v) {
1018                                 pol = NULL;
1019                                 goto out;
1020                         }
1021                         err = security_xfrm_policy_lookup(pol->security,
1022                                                       fl->flowi_secid,
1023                                                       policy_to_flow_dir(dir));
1024                         if (!err)
1025                                 xfrm_pol_hold(pol);
1026                         else if (err == -ESRCH)
1027                                 pol = NULL;
1028                         else
1029                                 pol = ERR_PTR(err);
1030                 } else
1031                         pol = NULL;
1032         }
1033 out:
1034         read_unlock_bh(&xfrm_policy_lock);
1035         return pol;
1036 }
1037
1038 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
1039 {
1040         struct net *net = xp_net(pol);
1041         struct hlist_head *chain = policy_hash_bysel(net, &pol->selector,
1042                                                      pol->family, dir);
1043
1044         list_add(&pol->walk.all, &net->xfrm.policy_all);
1045         hlist_add_head(&pol->bydst, chain);
1046         hlist_add_head(&pol->byidx, net->xfrm.policy_byidx+idx_hash(net, pol->index));
1047         net->xfrm.policy_count[dir]++;
1048         xfrm_pol_hold(pol);
1049
1050         if (xfrm_bydst_should_resize(net, dir, NULL))
1051                 schedule_work(&net->xfrm.policy_hash_work);
1052 }
1053
1054 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
1055                                                 int dir)
1056 {
1057         struct net *net = xp_net(pol);
1058
1059         if (hlist_unhashed(&pol->bydst))
1060                 return NULL;
1061
1062         hlist_del(&pol->bydst);
1063         hlist_del(&pol->byidx);
1064         list_del(&pol->walk.all);
1065         net->xfrm.policy_count[dir]--;
1066
1067         return pol;
1068 }
1069
1070 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
1071 {
1072         write_lock_bh(&xfrm_policy_lock);
1073         pol = __xfrm_policy_unlink(pol, dir);
1074         write_unlock_bh(&xfrm_policy_lock);
1075         if (pol) {
1076                 xfrm_policy_kill(pol);
1077                 return 0;
1078         }
1079         return -ENOENT;
1080 }
1081 EXPORT_SYMBOL(xfrm_policy_delete);
1082
1083 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
1084 {
1085         struct net *net = xp_net(pol);
1086         struct xfrm_policy *old_pol;
1087
1088 #ifdef CONFIG_XFRM_SUB_POLICY
1089         if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
1090                 return -EINVAL;
1091 #endif
1092
1093         write_lock_bh(&xfrm_policy_lock);
1094         old_pol = sk->sk_policy[dir];
1095         sk->sk_policy[dir] = pol;
1096         if (pol) {
1097                 pol->curlft.add_time = get_seconds();
1098                 pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir);
1099                 __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
1100         }
1101         if (old_pol)
1102                 /* Unlinking succeeds always. This is the only function
1103                  * allowed to delete or replace socket policy.
1104                  */
1105                 __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
1106         write_unlock_bh(&xfrm_policy_lock);
1107
1108         if (old_pol) {
1109                 xfrm_policy_kill(old_pol);
1110         }
1111         return 0;
1112 }
1113
1114 static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
1115 {
1116         struct xfrm_policy *newp = xfrm_policy_alloc(xp_net(old), GFP_ATOMIC);
1117
1118         if (newp) {
1119                 newp->selector = old->selector;
1120                 if (security_xfrm_policy_clone(old->security,
1121                                                &newp->security)) {
1122                         kfree(newp);
1123                         return NULL;  /* ENOMEM */
1124                 }
1125                 newp->lft = old->lft;
1126                 newp->curlft = old->curlft;
1127                 newp->mark = old->mark;
1128                 newp->action = old->action;
1129                 newp->flags = old->flags;
1130                 newp->xfrm_nr = old->xfrm_nr;
1131                 newp->index = old->index;
1132                 newp->type = old->type;
1133                 memcpy(newp->xfrm_vec, old->xfrm_vec,
1134                        newp->xfrm_nr*sizeof(struct xfrm_tmpl));
1135                 write_lock_bh(&xfrm_policy_lock);
1136                 __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir);
1137                 write_unlock_bh(&xfrm_policy_lock);
1138                 xfrm_pol_put(newp);
1139         }
1140         return newp;
1141 }
1142
1143 int __xfrm_sk_clone_policy(struct sock *sk)
1144 {
1145         struct xfrm_policy *p0 = sk->sk_policy[0],
1146                            *p1 = sk->sk_policy[1];
1147
1148         sk->sk_policy[0] = sk->sk_policy[1] = NULL;
1149         if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL)
1150                 return -ENOMEM;
1151         if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL)
1152                 return -ENOMEM;
1153         return 0;
1154 }
1155
1156 static int
1157 xfrm_get_saddr(struct net *net, xfrm_address_t *local, xfrm_address_t *remote,
1158                unsigned short family)
1159 {
1160         int err;
1161         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1162
1163         if (unlikely(afinfo == NULL))
1164                 return -EINVAL;
1165         err = afinfo->get_saddr(net, local, remote);
1166         xfrm_policy_put_afinfo(afinfo);
1167         return err;
1168 }
1169
1170 /* Resolve list of templates for the flow, given policy. */
1171
1172 static int
1173 xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
1174                       struct xfrm_state **xfrm, unsigned short family)
1175 {
1176         struct net *net = xp_net(policy);
1177         int nx;
1178         int i, error;
1179         xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
1180         xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
1181         xfrm_address_t tmp;
1182
1183         for (nx=0, i = 0; i < policy->xfrm_nr; i++) {
1184                 struct xfrm_state *x;
1185                 xfrm_address_t *remote = daddr;
1186                 xfrm_address_t *local  = saddr;
1187                 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
1188
1189                 if (tmpl->mode == XFRM_MODE_TUNNEL ||
1190                     tmpl->mode == XFRM_MODE_BEET) {
1191                         remote = &tmpl->id.daddr;
1192                         local = &tmpl->saddr;
1193                         if (xfrm_addr_any(local, tmpl->encap_family)) {
1194                                 error = xfrm_get_saddr(net, &tmp, remote, tmpl->encap_family);
1195                                 if (error)
1196                                         goto fail;
1197                                 local = &tmp;
1198                         }
1199                 }
1200
1201                 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
1202
1203                 if (x && x->km.state == XFRM_STATE_VALID) {
1204                         xfrm[nx++] = x;
1205                         daddr = remote;
1206                         saddr = local;
1207                         continue;
1208                 }
1209                 if (x) {
1210                         error = (x->km.state == XFRM_STATE_ERROR ?
1211                                  -EINVAL : -EAGAIN);
1212                         xfrm_state_put(x);
1213                 }
1214                 else if (error == -ESRCH)
1215                         error = -EAGAIN;
1216
1217                 if (!tmpl->optional)
1218                         goto fail;
1219         }
1220         return nx;
1221
1222 fail:
1223         for (nx--; nx>=0; nx--)
1224                 xfrm_state_put(xfrm[nx]);
1225         return error;
1226 }
1227
1228 static int
1229 xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, const struct flowi *fl,
1230                   struct xfrm_state **xfrm, unsigned short family)
1231 {
1232         struct xfrm_state *tp[XFRM_MAX_DEPTH];
1233         struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
1234         int cnx = 0;
1235         int error;
1236         int ret;
1237         int i;
1238
1239         for (i = 0; i < npols; i++) {
1240                 if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
1241                         error = -ENOBUFS;
1242                         goto fail;
1243                 }
1244
1245                 ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
1246                 if (ret < 0) {
1247                         error = ret;
1248                         goto fail;
1249                 } else
1250                         cnx += ret;
1251         }
1252
1253         /* found states are sorted for outbound processing */
1254         if (npols > 1)
1255                 xfrm_state_sort(xfrm, tpp, cnx, family);
1256
1257         return cnx;
1258
1259  fail:
1260         for (cnx--; cnx>=0; cnx--)
1261                 xfrm_state_put(tpp[cnx]);
1262         return error;
1263
1264 }
1265
1266 /* Check that the bundle accepts the flow and its components are
1267  * still valid.
1268  */
1269
1270 static inline int xfrm_get_tos(const struct flowi *fl, int family)
1271 {
1272         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1273         int tos;
1274
1275         if (!afinfo)
1276                 return -EINVAL;
1277
1278         tos = afinfo->get_tos(fl);
1279
1280         xfrm_policy_put_afinfo(afinfo);
1281
1282         return tos;
1283 }
1284
1285 static struct flow_cache_object *xfrm_bundle_flo_get(struct flow_cache_object *flo)
1286 {
1287         struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1288         struct dst_entry *dst = &xdst->u.dst;
1289
1290         if (xdst->route == NULL) {
1291                 /* Dummy bundle - if it has xfrms we were not
1292                  * able to build bundle as template resolution failed.
1293                  * It means we need to try again resolving. */
1294                 if (xdst->num_xfrms > 0)
1295                         return NULL;
1296         } else {
1297                 /* Real bundle */
1298                 if (stale_bundle(dst))
1299                         return NULL;
1300         }
1301
1302         dst_hold(dst);
1303         return flo;
1304 }
1305
1306 static int xfrm_bundle_flo_check(struct flow_cache_object *flo)
1307 {
1308         struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1309         struct dst_entry *dst = &xdst->u.dst;
1310
1311         if (!xdst->route)
1312                 return 0;
1313         if (stale_bundle(dst))
1314                 return 0;
1315
1316         return 1;
1317 }
1318
1319 static void xfrm_bundle_flo_delete(struct flow_cache_object *flo)
1320 {
1321         struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
1322         struct dst_entry *dst = &xdst->u.dst;
1323
1324         dst_free(dst);
1325 }
1326
1327 static const struct flow_cache_ops xfrm_bundle_fc_ops = {
1328         .get = xfrm_bundle_flo_get,
1329         .check = xfrm_bundle_flo_check,
1330         .delete = xfrm_bundle_flo_delete,
1331 };
1332
1333 static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
1334 {
1335         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1336         struct dst_ops *dst_ops;
1337         struct xfrm_dst *xdst;
1338
1339         if (!afinfo)
1340                 return ERR_PTR(-EINVAL);
1341
1342         switch (family) {
1343         case AF_INET:
1344                 dst_ops = &net->xfrm.xfrm4_dst_ops;
1345                 break;
1346 #if IS_ENABLED(CONFIG_IPV6)
1347         case AF_INET6:
1348                 dst_ops = &net->xfrm.xfrm6_dst_ops;
1349                 break;
1350 #endif
1351         default:
1352                 BUG();
1353         }
1354         xdst = dst_alloc(dst_ops, NULL, 0, DST_OBSOLETE_NONE, 0);
1355
1356         if (likely(xdst)) {
1357                 struct dst_entry *dst = &xdst->u.dst;
1358
1359                 memset(dst + 1, 0, sizeof(*xdst) - sizeof(*dst));
1360                 xdst->flo.ops = &xfrm_bundle_fc_ops;
1361                 if (afinfo->init_dst)
1362                         afinfo->init_dst(net, xdst);
1363         } else
1364                 xdst = ERR_PTR(-ENOBUFS);
1365
1366         xfrm_policy_put_afinfo(afinfo);
1367
1368         return xdst;
1369 }
1370
1371 static inline int xfrm_init_path(struct xfrm_dst *path, struct dst_entry *dst,
1372                                  int nfheader_len)
1373 {
1374         struct xfrm_policy_afinfo *afinfo =
1375                 xfrm_policy_get_afinfo(dst->ops->family);
1376         int err;
1377
1378         if (!afinfo)
1379                 return -EINVAL;
1380
1381         err = afinfo->init_path(path, dst, nfheader_len);
1382
1383         xfrm_policy_put_afinfo(afinfo);
1384
1385         return err;
1386 }
1387
1388 static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
1389                                 const struct flowi *fl)
1390 {
1391         struct xfrm_policy_afinfo *afinfo =
1392                 xfrm_policy_get_afinfo(xdst->u.dst.ops->family);
1393         int err;
1394
1395         if (!afinfo)
1396                 return -EINVAL;
1397
1398         err = afinfo->fill_dst(xdst, dev, fl);
1399
1400         xfrm_policy_put_afinfo(afinfo);
1401
1402         return err;
1403 }
1404
1405
1406 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
1407  * all the metrics... Shortly, bundle a bundle.
1408  */
1409
1410 static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
1411                                             struct xfrm_state **xfrm, int nx,
1412                                             const struct flowi *fl,
1413                                             struct dst_entry *dst)
1414 {
1415         struct net *net = xp_net(policy);
1416         unsigned long now = jiffies;
1417         struct net_device *dev;
1418         struct xfrm_mode *inner_mode;
1419         struct dst_entry *dst_prev = NULL;
1420         struct dst_entry *dst0 = NULL;
1421         int i = 0;
1422         int err;
1423         int header_len = 0;
1424         int nfheader_len = 0;
1425         int trailer_len = 0;
1426         int tos;
1427         int family = policy->selector.family;
1428         xfrm_address_t saddr, daddr;
1429
1430         xfrm_flowi_addr_get(fl, &saddr, &daddr, family);
1431
1432         tos = xfrm_get_tos(fl, family);
1433         err = tos;
1434         if (tos < 0)
1435                 goto put_states;
1436
1437         dst_hold(dst);
1438
1439         for (; i < nx; i++) {
1440                 struct xfrm_dst *xdst = xfrm_alloc_dst(net, family);
1441                 struct dst_entry *dst1 = &xdst->u.dst;
1442
1443                 err = PTR_ERR(xdst);
1444                 if (IS_ERR(xdst)) {
1445                         dst_release(dst);
1446                         goto put_states;
1447                 }
1448
1449                 if (xfrm[i]->sel.family == AF_UNSPEC) {
1450                         inner_mode = xfrm_ip2inner_mode(xfrm[i],
1451                                                         xfrm_af2proto(family));
1452                         if (!inner_mode) {
1453                                 err = -EAFNOSUPPORT;
1454                                 dst_release(dst);
1455                                 goto put_states;
1456                         }
1457                 } else
1458                         inner_mode = xfrm[i]->inner_mode;
1459
1460                 if (!dst_prev)
1461                         dst0 = dst1;
1462                 else {
1463                         dst_prev->child = dst_clone(dst1);
1464                         dst1->flags |= DST_NOHASH;
1465                 }
1466
1467                 xdst->route = dst;
1468                 dst_copy_metrics(dst1, dst);
1469
1470                 if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
1471                         family = xfrm[i]->props.family;
1472                         dst = xfrm_dst_lookup(xfrm[i], tos, &saddr, &daddr,
1473                                               family);
1474                         err = PTR_ERR(dst);
1475                         if (IS_ERR(dst))
1476                                 goto put_states;
1477                 } else
1478                         dst_hold(dst);
1479
1480                 dst1->xfrm = xfrm[i];
1481                 xdst->xfrm_genid = xfrm[i]->genid;
1482
1483                 dst1->obsolete = DST_OBSOLETE_FORCE_CHK;
1484                 dst1->flags |= DST_HOST;
1485                 dst1->lastuse = now;
1486
1487                 dst1->input = dst_discard;
1488                 dst1->output = inner_mode->afinfo->output;
1489
1490                 dst1->next = dst_prev;
1491                 dst_prev = dst1;
1492
1493                 header_len += xfrm[i]->props.header_len;
1494                 if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
1495                         nfheader_len += xfrm[i]->props.header_len;
1496                 trailer_len += xfrm[i]->props.trailer_len;
1497         }
1498
1499         dst_prev->child = dst;
1500         dst0->path = dst;
1501
1502         err = -ENODEV;
1503         dev = dst->dev;
1504         if (!dev)
1505                 goto free_dst;
1506
1507         xfrm_init_path((struct xfrm_dst *)dst0, dst, nfheader_len);
1508         xfrm_init_pmtu(dst_prev);
1509
1510         for (dst_prev = dst0; dst_prev != dst; dst_prev = dst_prev->child) {
1511                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst_prev;
1512
1513                 err = xfrm_fill_dst(xdst, dev, fl);
1514                 if (err)
1515                         goto free_dst;
1516
1517                 dst_prev->header_len = header_len;
1518                 dst_prev->trailer_len = trailer_len;
1519                 header_len -= xdst->u.dst.xfrm->props.header_len;
1520                 trailer_len -= xdst->u.dst.xfrm->props.trailer_len;
1521         }
1522
1523 out:
1524         return dst0;
1525
1526 put_states:
1527         for (; i < nx; i++)
1528                 xfrm_state_put(xfrm[i]);
1529 free_dst:
1530         if (dst0)
1531                 dst_free(dst0);
1532         dst0 = ERR_PTR(err);
1533         goto out;
1534 }
1535
1536 static int inline
1537 xfrm_dst_alloc_copy(void **target, const void *src, int size)
1538 {
1539         if (!*target) {
1540                 *target = kmalloc(size, GFP_ATOMIC);
1541                 if (!*target)
1542                         return -ENOMEM;
1543         }
1544         memcpy(*target, src, size);
1545         return 0;
1546 }
1547
1548 static int inline
1549 xfrm_dst_update_parent(struct dst_entry *dst, const struct xfrm_selector *sel)
1550 {
1551 #ifdef CONFIG_XFRM_SUB_POLICY
1552         struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1553         return xfrm_dst_alloc_copy((void **)&(xdst->partner),
1554                                    sel, sizeof(*sel));
1555 #else
1556         return 0;
1557 #endif
1558 }
1559
1560 static int inline
1561 xfrm_dst_update_origin(struct dst_entry *dst, const struct flowi *fl)
1562 {
1563 #ifdef CONFIG_XFRM_SUB_POLICY
1564         struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1565         return xfrm_dst_alloc_copy((void **)&(xdst->origin), fl, sizeof(*fl));
1566 #else
1567         return 0;
1568 #endif
1569 }
1570
1571 static int xfrm_expand_policies(const struct flowi *fl, u16 family,
1572                                 struct xfrm_policy **pols,
1573                                 int *num_pols, int *num_xfrms)
1574 {
1575         int i;
1576
1577         if (*num_pols == 0 || !pols[0]) {
1578                 *num_pols = 0;
1579                 *num_xfrms = 0;
1580                 return 0;
1581         }
1582         if (IS_ERR(pols[0]))
1583                 return PTR_ERR(pols[0]);
1584
1585         *num_xfrms = pols[0]->xfrm_nr;
1586
1587 #ifdef CONFIG_XFRM_SUB_POLICY
1588         if (pols[0] && pols[0]->action == XFRM_POLICY_ALLOW &&
1589             pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1590                 pols[1] = xfrm_policy_lookup_bytype(xp_net(pols[0]),
1591                                                     XFRM_POLICY_TYPE_MAIN,
1592                                                     fl, family,
1593                                                     XFRM_POLICY_OUT);
1594                 if (pols[1]) {
1595                         if (IS_ERR(pols[1])) {
1596                                 xfrm_pols_put(pols, *num_pols);
1597                                 return PTR_ERR(pols[1]);
1598                         }
1599                         (*num_pols) ++;
1600                         (*num_xfrms) += pols[1]->xfrm_nr;
1601                 }
1602         }
1603 #endif
1604         for (i = 0; i < *num_pols; i++) {
1605                 if (pols[i]->action != XFRM_POLICY_ALLOW) {
1606                         *num_xfrms = -1;
1607                         break;
1608                 }
1609         }
1610
1611         return 0;
1612
1613 }
1614
1615 static struct xfrm_dst *
1616 xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols,
1617                                const struct flowi *fl, u16 family,
1618                                struct dst_entry *dst_orig)
1619 {
1620         struct net *net = xp_net(pols[0]);
1621         struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
1622         struct dst_entry *dst;
1623         struct xfrm_dst *xdst;
1624         int err;
1625
1626         /* Try to instantiate a bundle */
1627         err = xfrm_tmpl_resolve(pols, num_pols, fl, xfrm, family);
1628         if (err <= 0) {
1629                 if (err != 0 && err != -EAGAIN)
1630                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
1631                 return ERR_PTR(err);
1632         }
1633
1634         dst = xfrm_bundle_create(pols[0], xfrm, err, fl, dst_orig);
1635         if (IS_ERR(dst)) {
1636                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR);
1637                 return ERR_CAST(dst);
1638         }
1639
1640         xdst = (struct xfrm_dst *)dst;
1641         xdst->num_xfrms = err;
1642         if (num_pols > 1)
1643                 err = xfrm_dst_update_parent(dst, &pols[1]->selector);
1644         else
1645                 err = xfrm_dst_update_origin(dst, fl);
1646         if (unlikely(err)) {
1647                 dst_free(dst);
1648                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLECHECKERROR);
1649                 return ERR_PTR(err);
1650         }
1651
1652         xdst->num_pols = num_pols;
1653         memcpy(xdst->pols, pols, sizeof(struct xfrm_policy*) * num_pols);
1654         xdst->policy_genid = atomic_read(&pols[0]->genid);
1655
1656         return xdst;
1657 }
1658
1659 static struct flow_cache_object *
1660 xfrm_bundle_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir,
1661                    struct flow_cache_object *oldflo, void *ctx)
1662 {
1663         struct dst_entry *dst_orig = (struct dst_entry *)ctx;
1664         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1665         struct xfrm_dst *xdst, *new_xdst;
1666         int num_pols = 0, num_xfrms = 0, i, err, pol_dead;
1667
1668         /* Check if the policies from old bundle are usable */
1669         xdst = NULL;
1670         if (oldflo) {
1671                 xdst = container_of(oldflo, struct xfrm_dst, flo);
1672                 num_pols = xdst->num_pols;
1673                 num_xfrms = xdst->num_xfrms;
1674                 pol_dead = 0;
1675                 for (i = 0; i < num_pols; i++) {
1676                         pols[i] = xdst->pols[i];
1677                         pol_dead |= pols[i]->walk.dead;
1678                 }
1679                 if (pol_dead) {
1680                         dst_free(&xdst->u.dst);
1681                         xdst = NULL;
1682                         num_pols = 0;
1683                         num_xfrms = 0;
1684                         oldflo = NULL;
1685                 }
1686         }
1687
1688         /* Resolve policies to use if we couldn't get them from
1689          * previous cache entry */
1690         if (xdst == NULL) {
1691                 num_pols = 1;
1692                 pols[0] = __xfrm_policy_lookup(net, fl, family, dir);
1693                 err = xfrm_expand_policies(fl, family, pols,
1694                                            &num_pols, &num_xfrms);
1695                 if (err < 0)
1696                         goto inc_error;
1697                 if (num_pols == 0)
1698                         return NULL;
1699                 if (num_xfrms <= 0)
1700                         goto make_dummy_bundle;
1701         }
1702
1703         new_xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family, dst_orig);
1704         if (IS_ERR(new_xdst)) {
1705                 err = PTR_ERR(new_xdst);
1706                 if (err != -EAGAIN)
1707                         goto error;
1708                 if (oldflo == NULL)
1709                         goto make_dummy_bundle;
1710                 dst_hold(&xdst->u.dst);
1711                 return oldflo;
1712         } else if (new_xdst == NULL) {
1713                 num_xfrms = 0;
1714                 if (oldflo == NULL)
1715                         goto make_dummy_bundle;
1716                 xdst->num_xfrms = 0;
1717                 dst_hold(&xdst->u.dst);
1718                 return oldflo;
1719         }
1720
1721         /* Kill the previous bundle */
1722         if (xdst) {
1723                 /* The policies were stolen for newly generated bundle */
1724                 xdst->num_pols = 0;
1725                 dst_free(&xdst->u.dst);
1726         }
1727
1728         /* Flow cache does not have reference, it dst_free()'s,
1729          * but we do need to return one reference for original caller */
1730         dst_hold(&new_xdst->u.dst);
1731         return &new_xdst->flo;
1732
1733 make_dummy_bundle:
1734         /* We found policies, but there's no bundles to instantiate:
1735          * either because the policy blocks, has no transformations or
1736          * we could not build template (no xfrm_states).*/
1737         xdst = xfrm_alloc_dst(net, family);
1738         if (IS_ERR(xdst)) {
1739                 xfrm_pols_put(pols, num_pols);
1740                 return ERR_CAST(xdst);
1741         }
1742         xdst->num_pols = num_pols;
1743         xdst->num_xfrms = num_xfrms;
1744         memcpy(xdst->pols, pols, sizeof(struct xfrm_policy*) * num_pols);
1745
1746         dst_hold(&xdst->u.dst);
1747         return &xdst->flo;
1748
1749 inc_error:
1750         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR);
1751 error:
1752         if (xdst != NULL)
1753                 dst_free(&xdst->u.dst);
1754         else
1755                 xfrm_pols_put(pols, num_pols);
1756         return ERR_PTR(err);
1757 }
1758
1759 static struct dst_entry *make_blackhole(struct net *net, u16 family,
1760                                         struct dst_entry *dst_orig)
1761 {
1762         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1763         struct dst_entry *ret;
1764
1765         if (!afinfo) {
1766                 dst_release(dst_orig);
1767                 return ERR_PTR(-EINVAL);
1768         } else {
1769                 ret = afinfo->blackhole_route(net, dst_orig);
1770         }
1771         xfrm_policy_put_afinfo(afinfo);
1772
1773         return ret;
1774 }
1775
1776 /* Main function: finds/creates a bundle for given flow.
1777  *
1778  * At the moment we eat a raw IP route. Mostly to speed up lookups
1779  * on interfaces with disabled IPsec.
1780  */
1781 struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
1782                               const struct flowi *fl,
1783                               struct sock *sk, int flags)
1784 {
1785         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1786         struct flow_cache_object *flo;
1787         struct xfrm_dst *xdst;
1788         struct dst_entry *dst, *route;
1789         u16 family = dst_orig->ops->family;
1790         u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
1791         int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
1792
1793 restart:
1794         dst = NULL;
1795         xdst = NULL;
1796         route = NULL;
1797
1798         if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
1799                 num_pols = 1;
1800                 pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
1801                 err = xfrm_expand_policies(fl, family, pols,
1802                                            &num_pols, &num_xfrms);
1803                 if (err < 0)
1804                         goto dropdst;
1805
1806                 if (num_pols) {
1807                         if (num_xfrms <= 0) {
1808                                 drop_pols = num_pols;
1809                                 goto no_transform;
1810                         }
1811
1812                         xdst = xfrm_resolve_and_create_bundle(
1813                                         pols, num_pols, fl,
1814                                         family, dst_orig);
1815                         if (IS_ERR(xdst)) {
1816                                 xfrm_pols_put(pols, num_pols);
1817                                 err = PTR_ERR(xdst);
1818                                 goto dropdst;
1819                         } else if (xdst == NULL) {
1820                                 num_xfrms = 0;
1821                                 drop_pols = num_pols;
1822                                 goto no_transform;
1823                         }
1824
1825                         dst_hold(&xdst->u.dst);
1826
1827                         spin_lock_bh(&xfrm_policy_sk_bundle_lock);
1828                         xdst->u.dst.next = xfrm_policy_sk_bundles;
1829                         xfrm_policy_sk_bundles = &xdst->u.dst;
1830                         spin_unlock_bh(&xfrm_policy_sk_bundle_lock);
1831
1832                         route = xdst->route;
1833                 }
1834         }
1835
1836         if (xdst == NULL) {
1837                 /* To accelerate a bit...  */
1838                 if ((dst_orig->flags & DST_NOXFRM) ||
1839                     !net->xfrm.policy_count[XFRM_POLICY_OUT])
1840                         goto nopol;
1841
1842                 flo = flow_cache_lookup(net, fl, family, dir,
1843                                         xfrm_bundle_lookup, dst_orig);
1844                 if (flo == NULL)
1845                         goto nopol;
1846                 if (IS_ERR(flo)) {
1847                         err = PTR_ERR(flo);
1848                         goto dropdst;
1849                 }
1850                 xdst = container_of(flo, struct xfrm_dst, flo);
1851
1852                 num_pols = xdst->num_pols;
1853                 num_xfrms = xdst->num_xfrms;
1854                 memcpy(pols, xdst->pols, sizeof(struct xfrm_policy*) * num_pols);
1855                 route = xdst->route;
1856         }
1857
1858         dst = &xdst->u.dst;
1859         if (route == NULL && num_xfrms > 0) {
1860                 /* The only case when xfrm_bundle_lookup() returns a
1861                  * bundle with null route, is when the template could
1862                  * not be resolved. It means policies are there, but
1863                  * bundle could not be created, since we don't yet
1864                  * have the xfrm_state's. We need to wait for KM to
1865                  * negotiate new SA's or bail out with error.*/
1866                 if (net->xfrm.sysctl_larval_drop) {
1867                         /* EREMOTE tells the caller to generate
1868                          * a one-shot blackhole route. */
1869                         dst_release(dst);
1870                         xfrm_pols_put(pols, drop_pols);
1871                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
1872
1873                         return make_blackhole(net, family, dst_orig);
1874                 }
1875                 if (fl->flowi_flags & FLOWI_FLAG_CAN_SLEEP) {
1876                         DECLARE_WAITQUEUE(wait, current);
1877
1878                         add_wait_queue(&net->xfrm.km_waitq, &wait);
1879                         set_current_state(TASK_INTERRUPTIBLE);
1880                         schedule();
1881                         set_current_state(TASK_RUNNING);
1882                         remove_wait_queue(&net->xfrm.km_waitq, &wait);
1883
1884                         if (!signal_pending(current)) {
1885                                 dst_release(dst);
1886                                 goto restart;
1887                         }
1888
1889                         err = -ERESTART;
1890                 } else
1891                         err = -EAGAIN;
1892
1893                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
1894                 goto error;
1895         }
1896
1897 no_transform:
1898         if (num_pols == 0)
1899                 goto nopol;
1900
1901         if ((flags & XFRM_LOOKUP_ICMP) &&
1902             !(pols[0]->flags & XFRM_POLICY_ICMP)) {
1903                 err = -ENOENT;
1904                 goto error;
1905         }
1906
1907         for (i = 0; i < num_pols; i++)
1908                 pols[i]->curlft.use_time = get_seconds();
1909
1910         if (num_xfrms < 0) {
1911                 /* Prohibit the flow */
1912                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLBLOCK);
1913                 err = -EPERM;
1914                 goto error;
1915         } else if (num_xfrms > 0) {
1916                 /* Flow transformed */
1917                 dst_release(dst_orig);
1918         } else {
1919                 /* Flow passes untransformed */
1920                 dst_release(dst);
1921                 dst = dst_orig;
1922         }
1923 ok:
1924         xfrm_pols_put(pols, drop_pols);
1925         if (dst && dst->xfrm &&
1926             dst->xfrm->props.mode == XFRM_MODE_TUNNEL)
1927                 dst->flags |= DST_XFRM_TUNNEL;
1928         return dst;
1929
1930 nopol:
1931         if (!(flags & XFRM_LOOKUP_ICMP)) {
1932                 dst = dst_orig;
1933                 goto ok;
1934         }
1935         err = -ENOENT;
1936 error:
1937         dst_release(dst);
1938 dropdst:
1939         dst_release(dst_orig);
1940         xfrm_pols_put(pols, drop_pols);
1941         return ERR_PTR(err);
1942 }
1943 EXPORT_SYMBOL(xfrm_lookup);
1944
1945 static inline int
1946 xfrm_secpath_reject(int idx, struct sk_buff *skb, const struct flowi *fl)
1947 {
1948         struct xfrm_state *x;
1949
1950         if (!skb->sp || idx < 0 || idx >= skb->sp->len)
1951                 return 0;
1952         x = skb->sp->xvec[idx];
1953         if (!x->type->reject)
1954                 return 0;
1955         return x->type->reject(x, skb, fl);
1956 }
1957
1958 /* When skb is transformed back to its "native" form, we have to
1959  * check policy restrictions. At the moment we make this in maximally
1960  * stupid way. Shame on me. :-) Of course, connected sockets must
1961  * have policy cached at them.
1962  */
1963
1964 static inline int
1965 xfrm_state_ok(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x,
1966               unsigned short family)
1967 {
1968         if (xfrm_state_kern(x))
1969                 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
1970         return  x->id.proto == tmpl->id.proto &&
1971                 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
1972                 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
1973                 x->props.mode == tmpl->mode &&
1974                 (tmpl->allalgs || (tmpl->aalgos & (1<<x->props.aalgo)) ||
1975                  !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
1976                 !(x->props.mode != XFRM_MODE_TRANSPORT &&
1977                   xfrm_state_addr_cmp(tmpl, x, family));
1978 }
1979
1980 /*
1981  * 0 or more than 0 is returned when validation is succeeded (either bypass
1982  * because of optional transport mode, or next index of the mathced secpath
1983  * state with the template.
1984  * -1 is returned when no matching template is found.
1985  * Otherwise "-2 - errored_index" is returned.
1986  */
1987 static inline int
1988 xfrm_policy_ok(const struct xfrm_tmpl *tmpl, const struct sec_path *sp, int start,
1989                unsigned short family)
1990 {
1991         int idx = start;
1992
1993         if (tmpl->optional) {
1994                 if (tmpl->mode == XFRM_MODE_TRANSPORT)
1995                         return start;
1996         } else
1997                 start = -1;
1998         for (; idx < sp->len; idx++) {
1999                 if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
2000                         return ++idx;
2001                 if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
2002                         if (start == -1)
2003                                 start = -2-idx;
2004                         break;
2005                 }
2006         }
2007         return start;
2008 }
2009
2010 int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
2011                           unsigned int family, int reverse)
2012 {
2013         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
2014         int err;
2015
2016         if (unlikely(afinfo == NULL))
2017                 return -EAFNOSUPPORT;
2018
2019         afinfo->decode_session(skb, fl, reverse);
2020         err = security_xfrm_decode_session(skb, &fl->flowi_secid);
2021         xfrm_policy_put_afinfo(afinfo);
2022         return err;
2023 }
2024 EXPORT_SYMBOL(__xfrm_decode_session);
2025
2026 static inline int secpath_has_nontransport(const struct sec_path *sp, int k, int *idxp)
2027 {
2028         for (; k < sp->len; k++) {
2029                 if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
2030                         *idxp = k;
2031                         return 1;
2032                 }
2033         }
2034
2035         return 0;
2036 }
2037
2038 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
2039                         unsigned short family)
2040 {
2041         struct net *net = dev_net(skb->dev);
2042         struct xfrm_policy *pol;
2043         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
2044         int npols = 0;
2045         int xfrm_nr;
2046         int pi;
2047         int reverse;
2048         struct flowi fl;
2049         u8 fl_dir;
2050         int xerr_idx = -1;
2051
2052         reverse = dir & ~XFRM_POLICY_MASK;
2053         dir &= XFRM_POLICY_MASK;
2054         fl_dir = policy_to_flow_dir(dir);
2055
2056         if (__xfrm_decode_session(skb, &fl, family, reverse) < 0) {
2057                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
2058                 return 0;
2059         }
2060
2061         nf_nat_decode_session(skb, &fl, family);
2062
2063         /* First, check used SA against their selectors. */
2064         if (skb->sp) {
2065                 int i;
2066
2067                 for (i=skb->sp->len-1; i>=0; i--) {
2068                         struct xfrm_state *x = skb->sp->xvec[i];
2069                         if (!xfrm_selector_match(&x->sel, &fl, family)) {
2070                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
2071                                 return 0;
2072                         }
2073                 }
2074         }
2075
2076         pol = NULL;
2077         if (sk && sk->sk_policy[dir]) {
2078                 pol = xfrm_sk_policy_lookup(sk, dir, &fl);
2079                 if (IS_ERR(pol)) {
2080                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2081                         return 0;
2082                 }
2083         }
2084
2085         if (!pol) {
2086                 struct flow_cache_object *flo;
2087
2088                 flo = flow_cache_lookup(net, &fl, family, fl_dir,
2089                                         xfrm_policy_lookup, NULL);
2090                 if (IS_ERR_OR_NULL(flo))
2091                         pol = ERR_CAST(flo);
2092                 else
2093                         pol = container_of(flo, struct xfrm_policy, flo);
2094         }
2095
2096         if (IS_ERR(pol)) {
2097                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2098                 return 0;
2099         }
2100
2101         if (!pol) {
2102                 if (skb->sp && secpath_has_nontransport(skb->sp, 0, &xerr_idx)) {
2103                         xfrm_secpath_reject(xerr_idx, skb, &fl);
2104                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS);
2105                         return 0;
2106                 }
2107                 return 1;
2108         }
2109
2110         pol->curlft.use_time = get_seconds();
2111
2112         pols[0] = pol;
2113         npols ++;
2114 #ifdef CONFIG_XFRM_SUB_POLICY
2115         if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
2116                 pols[1] = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN,
2117                                                     &fl, family,
2118                                                     XFRM_POLICY_IN);
2119                 if (pols[1]) {
2120                         if (IS_ERR(pols[1])) {
2121                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR);
2122                                 return 0;
2123                         }
2124                         pols[1]->curlft.use_time = get_seconds();
2125                         npols ++;
2126                 }
2127         }
2128 #endif
2129
2130         if (pol->action == XFRM_POLICY_ALLOW) {
2131                 struct sec_path *sp;
2132                 static struct sec_path dummy;
2133                 struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
2134                 struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
2135                 struct xfrm_tmpl **tpp = tp;
2136                 int ti = 0;
2137                 int i, k;
2138
2139                 if ((sp = skb->sp) == NULL)
2140                         sp = &dummy;
2141
2142                 for (pi = 0; pi < npols; pi++) {
2143                         if (pols[pi] != pol &&
2144                             pols[pi]->action != XFRM_POLICY_ALLOW) {
2145                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2146                                 goto reject;
2147                         }
2148                         if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH) {
2149                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
2150                                 goto reject_error;
2151                         }
2152                         for (i = 0; i < pols[pi]->xfrm_nr; i++)
2153                                 tpp[ti++] = &pols[pi]->xfrm_vec[i];
2154                 }
2155                 xfrm_nr = ti;
2156                 if (npols > 1) {
2157                         xfrm_tmpl_sort(stp, tpp, xfrm_nr, family);
2158                         tpp = stp;
2159                 }
2160
2161                 /* For each tunnel xfrm, find the first matching tmpl.
2162                  * For each tmpl before that, find corresponding xfrm.
2163                  * Order is _important_. Later we will implement
2164                  * some barriers, but at the moment barriers
2165                  * are implied between each two transformations.
2166                  */
2167                 for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
2168                         k = xfrm_policy_ok(tpp[i], sp, k, family);
2169                         if (k < 0) {
2170                                 if (k < -1)
2171                                         /* "-2 - errored_index" returned */
2172                                         xerr_idx = -(2+k);
2173                                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2174                                 goto reject;
2175                         }
2176                 }
2177
2178                 if (secpath_has_nontransport(sp, k, &xerr_idx)) {
2179                         XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH);
2180                         goto reject;
2181                 }
2182
2183                 xfrm_pols_put(pols, npols);
2184                 return 1;
2185         }
2186         XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK);
2187
2188 reject:
2189         xfrm_secpath_reject(xerr_idx, skb, &fl);
2190 reject_error:
2191         xfrm_pols_put(pols, npols);
2192         return 0;
2193 }
2194 EXPORT_SYMBOL(__xfrm_policy_check);
2195
2196 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
2197 {
2198         struct net *net = dev_net(skb->dev);
2199         struct flowi fl;
2200         struct dst_entry *dst;
2201         int res = 1;
2202
2203         if (xfrm_decode_session(skb, &fl, family) < 0) {
2204                 XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
2205                 return 0;
2206         }
2207
2208         skb_dst_force(skb);
2209
2210         dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, 0);
2211         if (IS_ERR(dst)) {
2212                 res = 0;
2213                 dst = NULL;
2214         }
2215         skb_dst_set(skb, dst);
2216         return res;
2217 }
2218 EXPORT_SYMBOL(__xfrm_route_forward);
2219
2220 /* Optimize later using cookies and generation ids. */
2221
2222 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
2223 {
2224         /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
2225          * to DST_OBSOLETE_FORCE_CHK to force all XFRM destinations to
2226          * get validated by dst_ops->check on every use.  We do this
2227          * because when a normal route referenced by an XFRM dst is
2228          * obsoleted we do not go looking around for all parent
2229          * referencing XFRM dsts so that we can invalidate them.  It
2230          * is just too much work.  Instead we make the checks here on
2231          * every use.  For example:
2232          *
2233          *      XFRM dst A --> IPv4 dst X
2234          *
2235          * X is the "xdst->route" of A (X is also the "dst->path" of A
2236          * in this example).  If X is marked obsolete, "A" will not
2237          * notice.  That's what we are validating here via the
2238          * stale_bundle() check.
2239          *
2240          * When a policy's bundle is pruned, we dst_free() the XFRM
2241          * dst which causes it's ->obsolete field to be set to
2242          * DST_OBSOLETE_DEAD.  If an XFRM dst has been pruned like
2243          * this, we want to force a new route lookup.
2244          */
2245         if (dst->obsolete < 0 && !stale_bundle(dst))
2246                 return dst;
2247
2248         return NULL;
2249 }
2250
2251 static int stale_bundle(struct dst_entry *dst)
2252 {
2253         return !xfrm_bundle_ok((struct xfrm_dst *)dst);
2254 }
2255
2256 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
2257 {
2258         while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
2259                 dst->dev = dev_net(dev)->loopback_dev;
2260                 dev_hold(dst->dev);
2261                 dev_put(dev);
2262         }
2263 }
2264 EXPORT_SYMBOL(xfrm_dst_ifdown);
2265
2266 static void xfrm_link_failure(struct sk_buff *skb)
2267 {
2268         /* Impossible. Such dst must be popped before reaches point of failure. */
2269 }
2270
2271 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
2272 {
2273         if (dst) {
2274                 if (dst->obsolete) {
2275                         dst_release(dst);
2276                         dst = NULL;
2277                 }
2278         }
2279         return dst;
2280 }
2281
2282 static void __xfrm_garbage_collect(struct net *net)
2283 {
2284         struct dst_entry *head, *next;
2285
2286         spin_lock_bh(&xfrm_policy_sk_bundle_lock);
2287         head = xfrm_policy_sk_bundles;
2288         xfrm_policy_sk_bundles = NULL;
2289         spin_unlock_bh(&xfrm_policy_sk_bundle_lock);
2290
2291         while (head) {
2292                 next = head->next;
2293                 dst_free(head);
2294                 head = next;
2295         }
2296 }
2297
2298 static void xfrm_garbage_collect(struct net *net)
2299 {
2300         flow_cache_flush();
2301         __xfrm_garbage_collect(net);
2302 }
2303
2304 static void xfrm_garbage_collect_deferred(struct net *net)
2305 {
2306         flow_cache_flush_deferred();
2307         __xfrm_garbage_collect(net);
2308 }
2309
2310 static void xfrm_init_pmtu(struct dst_entry *dst)
2311 {
2312         do {
2313                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2314                 u32 pmtu, route_mtu_cached;
2315
2316                 pmtu = dst_mtu(dst->child);
2317                 xdst->child_mtu_cached = pmtu;
2318
2319                 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
2320
2321                 route_mtu_cached = dst_mtu(xdst->route);
2322                 xdst->route_mtu_cached = route_mtu_cached;
2323
2324                 if (pmtu > route_mtu_cached)
2325                         pmtu = route_mtu_cached;
2326
2327                 dst_metric_set(dst, RTAX_MTU, pmtu);
2328         } while ((dst = dst->next));
2329 }
2330
2331 /* Check that the bundle accepts the flow and its components are
2332  * still valid.
2333  */
2334
2335 static int xfrm_bundle_ok(struct xfrm_dst *first)
2336 {
2337         struct dst_entry *dst = &first->u.dst;
2338         struct xfrm_dst *last;
2339         u32 mtu;
2340
2341         if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) ||
2342             (dst->dev && !netif_running(dst->dev)))
2343                 return 0;
2344
2345         last = NULL;
2346
2347         do {
2348                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2349
2350                 if (dst->xfrm->km.state != XFRM_STATE_VALID)
2351                         return 0;
2352                 if (xdst->xfrm_genid != dst->xfrm->genid)
2353                         return 0;
2354                 if (xdst->num_pols > 0 &&
2355                     xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
2356                         return 0;
2357
2358                 mtu = dst_mtu(dst->child);
2359                 if (xdst->child_mtu_cached != mtu) {
2360                         last = xdst;
2361                         xdst->child_mtu_cached = mtu;
2362                 }
2363
2364                 if (!dst_check(xdst->route, xdst->route_cookie))
2365                         return 0;
2366                 mtu = dst_mtu(xdst->route);
2367                 if (xdst->route_mtu_cached != mtu) {
2368                         last = xdst;
2369                         xdst->route_mtu_cached = mtu;
2370                 }
2371
2372                 dst = dst->child;
2373         } while (dst->xfrm);
2374
2375         if (likely(!last))
2376                 return 1;
2377
2378         mtu = last->child_mtu_cached;
2379         for (;;) {
2380                 dst = &last->u.dst;
2381
2382                 mtu = xfrm_state_mtu(dst->xfrm, mtu);
2383                 if (mtu > last->route_mtu_cached)
2384                         mtu = last->route_mtu_cached;
2385                 dst_metric_set(dst, RTAX_MTU, mtu);
2386
2387                 if (last == first)
2388                         break;
2389
2390                 last = (struct xfrm_dst *)last->u.dst.next;
2391                 last->child_mtu_cached = mtu;
2392         }
2393
2394         return 1;
2395 }
2396
2397 static unsigned int xfrm_default_advmss(const struct dst_entry *dst)
2398 {
2399         return dst_metric_advmss(dst->path);
2400 }
2401
2402 static unsigned int xfrm_mtu(const struct dst_entry *dst)
2403 {
2404         unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2405
2406         return mtu ? : dst_mtu(dst->path);
2407 }
2408
2409 static struct neighbour *xfrm_neigh_lookup(const struct dst_entry *dst,
2410                                            struct sk_buff *skb,
2411                                            const void *daddr)
2412 {
2413         return dst->path->ops->neigh_lookup(dst, skb, daddr);
2414 }
2415
2416 int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
2417 {
2418         struct net *net;
2419         int err = 0;
2420         if (unlikely(afinfo == NULL))
2421                 return -EINVAL;
2422         if (unlikely(afinfo->family >= NPROTO))
2423                 return -EAFNOSUPPORT;
2424         write_lock_bh(&xfrm_policy_afinfo_lock);
2425         if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
2426                 err = -ENOBUFS;
2427         else {
2428                 struct dst_ops *dst_ops = afinfo->dst_ops;
2429                 if (likely(dst_ops->kmem_cachep == NULL))
2430                         dst_ops->kmem_cachep = xfrm_dst_cache;
2431                 if (likely(dst_ops->check == NULL))
2432                         dst_ops->check = xfrm_dst_check;
2433                 if (likely(dst_ops->default_advmss == NULL))
2434                         dst_ops->default_advmss = xfrm_default_advmss;
2435                 if (likely(dst_ops->mtu == NULL))
2436                         dst_ops->mtu = xfrm_mtu;
2437                 if (likely(dst_ops->negative_advice == NULL))
2438                         dst_ops->negative_advice = xfrm_negative_advice;
2439                 if (likely(dst_ops->link_failure == NULL))
2440                         dst_ops->link_failure = xfrm_link_failure;
2441                 if (likely(dst_ops->neigh_lookup == NULL))
2442                         dst_ops->neigh_lookup = xfrm_neigh_lookup;
2443                 if (likely(afinfo->garbage_collect == NULL))
2444                         afinfo->garbage_collect = xfrm_garbage_collect_deferred;
2445                 xfrm_policy_afinfo[afinfo->family] = afinfo;
2446         }
2447         write_unlock_bh(&xfrm_policy_afinfo_lock);
2448
2449         rtnl_lock();
2450         for_each_net(net) {
2451                 struct dst_ops *xfrm_dst_ops;
2452
2453                 switch (afinfo->family) {
2454                 case AF_INET:
2455                         xfrm_dst_ops = &net->xfrm.xfrm4_dst_ops;
2456                         break;
2457 #if IS_ENABLED(CONFIG_IPV6)
2458                 case AF_INET6:
2459                         xfrm_dst_ops = &net->xfrm.xfrm6_dst_ops;
2460                         break;
2461 #endif
2462                 default:
2463                         BUG();
2464                 }
2465                 *xfrm_dst_ops = *afinfo->dst_ops;
2466         }
2467         rtnl_unlock();
2468
2469         return err;
2470 }
2471 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
2472
2473 int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
2474 {
2475         int err = 0;
2476         if (unlikely(afinfo == NULL))
2477                 return -EINVAL;
2478         if (unlikely(afinfo->family >= NPROTO))
2479                 return -EAFNOSUPPORT;
2480         write_lock_bh(&xfrm_policy_afinfo_lock);
2481         if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
2482                 if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
2483                         err = -EINVAL;
2484                 else {
2485                         struct dst_ops *dst_ops = afinfo->dst_ops;
2486                         xfrm_policy_afinfo[afinfo->family] = NULL;
2487                         dst_ops->kmem_cachep = NULL;
2488                         dst_ops->check = NULL;
2489                         dst_ops->negative_advice = NULL;
2490                         dst_ops->link_failure = NULL;
2491                         afinfo->garbage_collect = NULL;
2492                 }
2493         }
2494         write_unlock_bh(&xfrm_policy_afinfo_lock);
2495         return err;
2496 }
2497 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
2498
2499 static void __net_init xfrm_dst_ops_init(struct net *net)
2500 {
2501         struct xfrm_policy_afinfo *afinfo;
2502
2503         read_lock_bh(&xfrm_policy_afinfo_lock);
2504         afinfo = xfrm_policy_afinfo[AF_INET];
2505         if (afinfo)
2506                 net->xfrm.xfrm4_dst_ops = *afinfo->dst_ops;
2507 #if IS_ENABLED(CONFIG_IPV6)
2508         afinfo = xfrm_policy_afinfo[AF_INET6];
2509         if (afinfo)
2510                 net->xfrm.xfrm6_dst_ops = *afinfo->dst_ops;
2511 #endif
2512         read_unlock_bh(&xfrm_policy_afinfo_lock);
2513 }
2514
2515 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
2516 {
2517         struct xfrm_policy_afinfo *afinfo;
2518         if (unlikely(family >= NPROTO))
2519                 return NULL;
2520         read_lock(&xfrm_policy_afinfo_lock);
2521         afinfo = xfrm_policy_afinfo[family];
2522         if (unlikely(!afinfo))
2523                 read_unlock(&xfrm_policy_afinfo_lock);
2524         return afinfo;
2525 }
2526
2527 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
2528 {
2529         read_unlock(&xfrm_policy_afinfo_lock);
2530 }
2531
2532 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
2533 {
2534         struct net_device *dev = ptr;
2535
2536         switch (event) {
2537         case NETDEV_DOWN:
2538                 xfrm_garbage_collect(dev_net(dev));
2539         }
2540         return NOTIFY_DONE;
2541 }
2542
2543 static struct notifier_block xfrm_dev_notifier = {
2544         .notifier_call  = xfrm_dev_event,
2545 };
2546
2547 #ifdef CONFIG_XFRM_STATISTICS
2548 static int __net_init xfrm_statistics_init(struct net *net)
2549 {
2550         int rv;
2551
2552         if (snmp_mib_init((void __percpu **)net->mib.xfrm_statistics,
2553                           sizeof(struct linux_xfrm_mib),
2554                           __alignof__(struct linux_xfrm_mib)) < 0)
2555                 return -ENOMEM;
2556         rv = xfrm_proc_init(net);
2557         if (rv < 0)
2558                 snmp_mib_free((void __percpu **)net->mib.xfrm_statistics);
2559         return rv;
2560 }
2561
2562 static void xfrm_statistics_fini(struct net *net)
2563 {
2564         xfrm_proc_fini(net);
2565         snmp_mib_free((void __percpu **)net->mib.xfrm_statistics);
2566 }
2567 #else
2568 static int __net_init xfrm_statistics_init(struct net *net)
2569 {
2570         return 0;
2571 }
2572
2573 static void xfrm_statistics_fini(struct net *net)
2574 {
2575 }
2576 #endif
2577
2578 static int __net_init xfrm_policy_init(struct net *net)
2579 {
2580         unsigned int hmask, sz;
2581         int dir;
2582
2583         if (net_eq(net, &init_net))
2584                 xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
2585                                            sizeof(struct xfrm_dst),
2586                                            0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
2587                                            NULL);
2588
2589         hmask = 8 - 1;
2590         sz = (hmask+1) * sizeof(struct hlist_head);
2591
2592         net->xfrm.policy_byidx = xfrm_hash_alloc(sz);
2593         if (!net->xfrm.policy_byidx)
2594                 goto out_byidx;
2595         net->xfrm.policy_idx_hmask = hmask;
2596
2597         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
2598                 struct xfrm_policy_hash *htab;
2599
2600                 net->xfrm.policy_count[dir] = 0;
2601                 INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
2602
2603                 htab = &net->xfrm.policy_bydst[dir];
2604                 htab->table = xfrm_hash_alloc(sz);
2605                 if (!htab->table)
2606                         goto out_bydst;
2607                 htab->hmask = hmask;
2608         }
2609
2610         INIT_LIST_HEAD(&net->xfrm.policy_all);
2611         INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
2612         if (net_eq(net, &init_net))
2613                 register_netdevice_notifier(&xfrm_dev_notifier);
2614         return 0;
2615
2616 out_bydst:
2617         for (dir--; dir >= 0; dir--) {
2618                 struct xfrm_policy_hash *htab;
2619
2620                 htab = &net->xfrm.policy_bydst[dir];
2621                 xfrm_hash_free(htab->table, sz);
2622         }
2623         xfrm_hash_free(net->xfrm.policy_byidx, sz);
2624 out_byidx:
2625         return -ENOMEM;
2626 }
2627
2628 static void xfrm_policy_fini(struct net *net)
2629 {
2630         struct xfrm_audit audit_info;
2631         unsigned int sz;
2632         int dir;
2633
2634         flush_work(&net->xfrm.policy_hash_work);
2635 #ifdef CONFIG_XFRM_SUB_POLICY
2636         audit_info.loginuid = -1;
2637         audit_info.sessionid = -1;
2638         audit_info.secid = 0;
2639         xfrm_policy_flush(net, XFRM_POLICY_TYPE_SUB, &audit_info);
2640 #endif
2641         audit_info.loginuid = -1;
2642         audit_info.sessionid = -1;
2643         audit_info.secid = 0;
2644         xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, &audit_info);
2645
2646         WARN_ON(!list_empty(&net->xfrm.policy_all));
2647
2648         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
2649                 struct xfrm_policy_hash *htab;
2650
2651                 WARN_ON(!hlist_empty(&net->xfrm.policy_inexact[dir]));
2652
2653                 htab = &net->xfrm.policy_bydst[dir];
2654                 sz = (htab->hmask + 1);
2655                 WARN_ON(!hlist_empty(htab->table));
2656                 xfrm_hash_free(htab->table, sz);
2657         }
2658
2659         sz = (net->xfrm.policy_idx_hmask + 1) * sizeof(struct hlist_head);
2660         WARN_ON(!hlist_empty(net->xfrm.policy_byidx));
2661         xfrm_hash_free(net->xfrm.policy_byidx, sz);
2662 }
2663
2664 static int __net_init xfrm_net_init(struct net *net)
2665 {
2666         int rv;
2667
2668         rv = xfrm_statistics_init(net);
2669         if (rv < 0)
2670                 goto out_statistics;
2671         rv = xfrm_state_init(net);
2672         if (rv < 0)
2673                 goto out_state;
2674         rv = xfrm_policy_init(net);
2675         if (rv < 0)
2676                 goto out_policy;
2677         xfrm_dst_ops_init(net);
2678         rv = xfrm_sysctl_init(net);
2679         if (rv < 0)
2680                 goto out_sysctl;
2681         return 0;
2682
2683 out_sysctl:
2684         xfrm_policy_fini(net);
2685 out_policy:
2686         xfrm_state_fini(net);
2687 out_state:
2688         xfrm_statistics_fini(net);
2689 out_statistics:
2690         return rv;
2691 }
2692
2693 static void __net_exit xfrm_net_exit(struct net *net)
2694 {
2695         xfrm_sysctl_fini(net);
2696         xfrm_policy_fini(net);
2697         xfrm_state_fini(net);
2698         xfrm_statistics_fini(net);
2699 }
2700
2701 static struct pernet_operations __net_initdata xfrm_net_ops = {
2702         .init = xfrm_net_init,
2703         .exit = xfrm_net_exit,
2704 };
2705
2706 void __init xfrm_init(void)
2707 {
2708         register_pernet_subsys(&xfrm_net_ops);
2709         xfrm_input_init();
2710 }
2711
2712 #ifdef CONFIG_AUDITSYSCALL
2713 static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
2714                                          struct audit_buffer *audit_buf)
2715 {
2716         struct xfrm_sec_ctx *ctx = xp->security;
2717         struct xfrm_selector *sel = &xp->selector;
2718
2719         if (ctx)
2720                 audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
2721                                  ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str);
2722
2723         switch(sel->family) {
2724         case AF_INET:
2725                 audit_log_format(audit_buf, " src=%pI4", &sel->saddr.a4);
2726                 if (sel->prefixlen_s != 32)
2727                         audit_log_format(audit_buf, " src_prefixlen=%d",
2728                                          sel->prefixlen_s);
2729                 audit_log_format(audit_buf, " dst=%pI4", &sel->daddr.a4);
2730                 if (sel->prefixlen_d != 32)
2731                         audit_log_format(audit_buf, " dst_prefixlen=%d",
2732                                          sel->prefixlen_d);
2733                 break;
2734         case AF_INET6:
2735                 audit_log_format(audit_buf, " src=%pI6", sel->saddr.a6);
2736                 if (sel->prefixlen_s != 128)
2737                         audit_log_format(audit_buf, " src_prefixlen=%d",
2738                                          sel->prefixlen_s);
2739                 audit_log_format(audit_buf, " dst=%pI6", sel->daddr.a6);
2740                 if (sel->prefixlen_d != 128)
2741                         audit_log_format(audit_buf, " dst_prefixlen=%d",
2742                                          sel->prefixlen_d);
2743                 break;
2744         }
2745 }
2746
2747 void xfrm_audit_policy_add(struct xfrm_policy *xp, int result,
2748                            uid_t auid, u32 sessionid, u32 secid)
2749 {
2750         struct audit_buffer *audit_buf;
2751
2752         audit_buf = xfrm_audit_start("SPD-add");
2753         if (audit_buf == NULL)
2754                 return;
2755         xfrm_audit_helper_usrinfo(auid, sessionid, secid, audit_buf);
2756         audit_log_format(audit_buf, " res=%u", result);
2757         xfrm_audit_common_policyinfo(xp, audit_buf);
2758         audit_log_end(audit_buf);
2759 }
2760 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
2761
2762 void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
2763                               uid_t auid, u32 sessionid, u32 secid)
2764 {
2765         struct audit_buffer *audit_buf;
2766
2767         audit_buf = xfrm_audit_start("SPD-delete");
2768         if (audit_buf == NULL)
2769                 return;
2770         xfrm_audit_helper_usrinfo(auid, sessionid, secid, audit_buf);
2771         audit_log_format(audit_buf, " res=%u", result);
2772         xfrm_audit_common_policyinfo(xp, audit_buf);
2773         audit_log_end(audit_buf);
2774 }
2775 EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
2776 #endif
2777
2778 #ifdef CONFIG_XFRM_MIGRATE
2779 static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp,
2780                                         const struct xfrm_selector *sel_tgt)
2781 {
2782         if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
2783                 if (sel_tgt->family == sel_cmp->family &&
2784                     xfrm_addr_cmp(&sel_tgt->daddr, &sel_cmp->daddr,
2785                                   sel_cmp->family) == 0 &&
2786                     xfrm_addr_cmp(&sel_tgt->saddr, &sel_cmp->saddr,
2787                                   sel_cmp->family) == 0 &&
2788                     sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
2789                     sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
2790                         return true;
2791                 }
2792         } else {
2793                 if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
2794                         return true;
2795                 }
2796         }
2797         return false;
2798 }
2799
2800 static struct xfrm_policy * xfrm_migrate_policy_find(const struct xfrm_selector *sel,
2801                                                      u8 dir, u8 type)
2802 {
2803         struct xfrm_policy *pol, *ret = NULL;
2804         struct hlist_node *entry;
2805         struct hlist_head *chain;
2806         u32 priority = ~0U;
2807
2808         read_lock_bh(&xfrm_policy_lock);
2809         chain = policy_hash_direct(&init_net, &sel->daddr, &sel->saddr, sel->family, dir);
2810         hlist_for_each_entry(pol, entry, chain, bydst) {
2811                 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
2812                     pol->type == type) {
2813                         ret = pol;
2814                         priority = ret->priority;
2815                         break;
2816                 }
2817         }
2818         chain = &init_net.xfrm.policy_inexact[dir];
2819         hlist_for_each_entry(pol, entry, chain, bydst) {
2820                 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
2821                     pol->type == type &&
2822                     pol->priority < priority) {
2823                         ret = pol;
2824                         break;
2825                 }
2826         }
2827
2828         if (ret)
2829                 xfrm_pol_hold(ret);
2830
2831         read_unlock_bh(&xfrm_policy_lock);
2832
2833         return ret;
2834 }
2835
2836 static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t)
2837 {
2838         int match = 0;
2839
2840         if (t->mode == m->mode && t->id.proto == m->proto &&
2841             (m->reqid == 0 || t->reqid == m->reqid)) {
2842                 switch (t->mode) {
2843                 case XFRM_MODE_TUNNEL:
2844                 case XFRM_MODE_BEET:
2845                         if (xfrm_addr_cmp(&t->id.daddr, &m->old_daddr,
2846                                           m->old_family) == 0 &&
2847                             xfrm_addr_cmp(&t->saddr, &m->old_saddr,
2848                                           m->old_family) == 0) {
2849                                 match = 1;
2850                         }
2851                         break;
2852                 case XFRM_MODE_TRANSPORT:
2853                         /* in case of transport mode, template does not store
2854                            any IP addresses, hence we just compare mode and
2855                            protocol */
2856                         match = 1;
2857                         break;
2858                 default:
2859                         break;
2860                 }
2861         }
2862         return match;
2863 }
2864
2865 /* update endpoint address(es) of template(s) */
2866 static int xfrm_policy_migrate(struct xfrm_policy *pol,
2867                                struct xfrm_migrate *m, int num_migrate)
2868 {
2869         struct xfrm_migrate *mp;
2870         int i, j, n = 0;
2871
2872         write_lock_bh(&pol->lock);
2873         if (unlikely(pol->walk.dead)) {
2874                 /* target policy has been deleted */
2875                 write_unlock_bh(&pol->lock);
2876                 return -ENOENT;
2877         }
2878
2879         for (i = 0; i < pol->xfrm_nr; i++) {
2880                 for (j = 0, mp = m; j < num_migrate; j++, mp++) {
2881                         if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
2882                                 continue;
2883                         n++;
2884                         if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
2885                             pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
2886                                 continue;
2887                         /* update endpoints */
2888                         memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
2889                                sizeof(pol->xfrm_vec[i].id.daddr));
2890                         memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
2891                                sizeof(pol->xfrm_vec[i].saddr));
2892                         pol->xfrm_vec[i].encap_family = mp->new_family;
2893                         /* flush bundles */
2894                         atomic_inc(&pol->genid);
2895                 }
2896         }
2897
2898         write_unlock_bh(&pol->lock);
2899
2900         if (!n)
2901                 return -ENODATA;
2902
2903         return 0;
2904 }
2905
2906 static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate)
2907 {
2908         int i, j;
2909
2910         if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
2911                 return -EINVAL;
2912
2913         for (i = 0; i < num_migrate; i++) {
2914                 if ((xfrm_addr_cmp(&m[i].old_daddr, &m[i].new_daddr,
2915                                    m[i].old_family) == 0) &&
2916                     (xfrm_addr_cmp(&m[i].old_saddr, &m[i].new_saddr,
2917                                    m[i].old_family) == 0))
2918                         return -EINVAL;
2919                 if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
2920                     xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
2921                         return -EINVAL;
2922
2923                 /* check if there is any duplicated entry */
2924                 for (j = i + 1; j < num_migrate; j++) {
2925                         if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
2926                                     sizeof(m[i].old_daddr)) &&
2927                             !memcmp(&m[i].old_saddr, &m[j].old_saddr,
2928                                     sizeof(m[i].old_saddr)) &&
2929                             m[i].proto == m[j].proto &&
2930                             m[i].mode == m[j].mode &&
2931                             m[i].reqid == m[j].reqid &&
2932                             m[i].old_family == m[j].old_family)
2933                                 return -EINVAL;
2934                 }
2935         }
2936
2937         return 0;
2938 }
2939
2940 int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
2941                  struct xfrm_migrate *m, int num_migrate,
2942                  struct xfrm_kmaddress *k)
2943 {
2944         int i, err, nx_cur = 0, nx_new = 0;
2945         struct xfrm_policy *pol = NULL;
2946         struct xfrm_state *x, *xc;
2947         struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
2948         struct xfrm_state *x_new[XFRM_MAX_DEPTH];
2949         struct xfrm_migrate *mp;
2950
2951         if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
2952                 goto out;
2953
2954         /* Stage 1 - find policy */
2955         if ((pol = xfrm_migrate_policy_find(sel, dir, type)) == NULL) {
2956                 err = -ENOENT;
2957                 goto out;
2958         }
2959
2960         /* Stage 2 - find and update state(s) */
2961         for (i = 0, mp = m; i < num_migrate; i++, mp++) {
2962                 if ((x = xfrm_migrate_state_find(mp))) {
2963                         x_cur[nx_cur] = x;
2964                         nx_cur++;
2965                         if ((xc = xfrm_state_migrate(x, mp))) {
2966                                 x_new[nx_new] = xc;
2967                                 nx_new++;
2968                         } else {
2969                                 err = -ENODATA;
2970                                 goto restore_state;
2971                         }
2972                 }
2973         }
2974
2975         /* Stage 3 - update policy */
2976         if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
2977                 goto restore_state;
2978
2979         /* Stage 4 - delete old state(s) */
2980         if (nx_cur) {
2981                 xfrm_states_put(x_cur, nx_cur);
2982                 xfrm_states_delete(x_cur, nx_cur);
2983         }
2984
2985         /* Stage 5 - announce */
2986         km_migrate(sel, dir, type, m, num_migrate, k);
2987
2988         xfrm_pol_put(pol);
2989
2990         return 0;
2991 out:
2992         return err;
2993
2994 restore_state:
2995         if (pol)
2996                 xfrm_pol_put(pol);
2997         if (nx_cur)
2998                 xfrm_states_put(x_cur, nx_cur);
2999         if (nx_new)
3000                 xfrm_states_delete(x_new, nx_new);
3001
3002         return err;
3003 }
3004 EXPORT_SYMBOL(xfrm_migrate);
3005 #endif