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 <net/dst.h>
  28 #include <net/xfrm.h>
  29 #include <net/ip.h>
  30
  31 #include "xfrm_hash.h"
  32
  33 int sysctl_xfrm_larval_drop __read_mostly;
  34
  35 DEFINE_MUTEX(xfrm_cfg_mutex);
  36 EXPORT_SYMBOL(xfrm_cfg_mutex);
  37
  38 static DEFINE_RWLOCK(xfrm_policy_lock);
  39
  40 unsigned int xfrm_policy_count[XFRM_POLICY_MAX*2];
  41 EXPORT_SYMBOL(xfrm_policy_count);
  42
  43 static DEFINE_RWLOCK(xfrm_policy_afinfo_lock);
  44 static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO];
  45
  46 static struct kmem_cache *xfrm_dst_cache __read_mostly;
  47
  48 static struct work_struct xfrm_policy_gc_work;
  49 static HLIST_HEAD(xfrm_policy_gc_list);
  50 static DEFINE_SPINLOCK(xfrm_policy_gc_lock);
  51
  52 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family);
  53 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);
  54 static void xfrm_init_pmtu(struct dst_entry *dst);
  55
  56 static inline int
  57 __xfrm4_selector_match(struct xfrm_selector *sel, struct flowi *fl)
  58 {
  59         return  addr_match(&fl->fl4_dst, &sel->daddr, sel->prefixlen_d) &&
  60                 addr_match(&fl->fl4_src, &sel->saddr, sel->prefixlen_s) &&
  61                 !((xfrm_flowi_dport(fl) ^ sel->dport) & sel->dport_mask) &&
  62                 !((xfrm_flowi_sport(fl) ^ sel->sport) & sel->sport_mask) &&
  63                 (fl->proto == sel->proto || !sel->proto) &&
  64                 (fl->oif == sel->ifindex || !sel->ifindex);
  65 }
  66
  67 static inline int
  68 __xfrm6_selector_match(struct xfrm_selector *sel, struct flowi *fl)
  69 {
  70         return  addr_match(&fl->fl6_dst, &sel->daddr, sel->prefixlen_d) &&
  71                 addr_match(&fl->fl6_src, &sel->saddr, sel->prefixlen_s) &&
  72                 !((xfrm_flowi_dport(fl) ^ sel->dport) & sel->dport_mask) &&
  73                 !((xfrm_flowi_sport(fl) ^ sel->sport) & sel->sport_mask) &&
  74                 (fl->proto == sel->proto || !sel->proto) &&
  75                 (fl->oif == sel->ifindex || !sel->ifindex);
  76 }
  77
  78 int xfrm_selector_match(struct xfrm_selector *sel, struct flowi *fl,
  79                     unsigned short family)
  80 {
  81         switch (family) {
  82         case AF_INET:
  83                 return __xfrm4_selector_match(sel, fl);
  84         case AF_INET6:
  85                 return __xfrm6_selector_match(sel, fl);
  86         }
  87         return 0;
  88 }
  89
  90 static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x, int tos,
  91                                                 int family)
  92 {
  93         xfrm_address_t *saddr = &x->props.saddr;
  94         xfrm_address_t *daddr = &x->id.daddr;
  95         struct xfrm_policy_afinfo *afinfo;
  96         struct dst_entry *dst;
  97
  98         if (x->type->flags & XFRM_TYPE_LOCAL_COADDR)
  99                 saddr = x->coaddr;
 100         if (x->type->flags & XFRM_TYPE_REMOTE_COADDR)
 101                 daddr = x->coaddr;
 102
 103         afinfo = xfrm_policy_get_afinfo(family);
 104         if (unlikely(afinfo == NULL))
 105                 return ERR_PTR(-EAFNOSUPPORT);
 106
 107         dst = afinfo->dst_lookup(tos, saddr, daddr);
 108         xfrm_policy_put_afinfo(afinfo);
 109         return dst;
 110 }
 111
 112 static inline unsigned long make_jiffies(long secs)
 113 {
 114         if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
 115                 return MAX_SCHEDULE_TIMEOUT-1;
 116         else
 117                 return secs*HZ;
 118 }
 119
 120 static void xfrm_policy_timer(unsigned long data)
 121 {
 122         struct xfrm_policy *xp = (struct xfrm_policy*)data;
 123         unsigned long now = get_seconds();
 124         long next = LONG_MAX;
 125         int warn = 0;
 126         int dir;
 127
 128         read_lock(&xp->lock);
 129
 130         if (xp->dead)
 131                 goto out;
 132
 133         dir = xfrm_policy_id2dir(xp->index);
 134
 135         if (xp->lft.hard_add_expires_seconds) {
 136                 long tmo = xp->lft.hard_add_expires_seconds +
 137                         xp->curlft.add_time - now;
 138                 if (tmo <= 0)
 139                         goto expired;
 140                 if (tmo < next)
 141                         next = tmo;
 142         }
 143         if (xp->lft.hard_use_expires_seconds) {
 144                 long tmo = xp->lft.hard_use_expires_seconds +
 145                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 146                 if (tmo <= 0)
 147                         goto expired;
 148                 if (tmo < next)
 149                         next = tmo;
 150         }
 151         if (xp->lft.soft_add_expires_seconds) {
 152                 long tmo = xp->lft.soft_add_expires_seconds +
 153                         xp->curlft.add_time - now;
 154                 if (tmo <= 0) {
 155                         warn = 1;
 156                         tmo = XFRM_KM_TIMEOUT;
 157                 }
 158                 if (tmo < next)
 159                         next = tmo;
 160         }
 161         if (xp->lft.soft_use_expires_seconds) {
 162                 long tmo = xp->lft.soft_use_expires_seconds +
 163                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 164                 if (tmo <= 0) {
 165                         warn = 1;
 166                         tmo = XFRM_KM_TIMEOUT;
 167                 }
 168                 if (tmo < next)
 169                         next = tmo;
 170         }
 171
 172         if (warn)
 173                 km_policy_expired(xp, dir, 0, 0);
 174         if (next != LONG_MAX &&
 175             !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
 176                 xfrm_pol_hold(xp);
 177
 178 out:
 179         read_unlock(&xp->lock);
 180         xfrm_pol_put(xp);
 181         return;
 182
 183 expired:
 184         read_unlock(&xp->lock);
 185         if (!xfrm_policy_delete(xp, dir))
 186                 km_policy_expired(xp, dir, 1, 0);
 187         xfrm_pol_put(xp);
 188 }
 189
 190
 191 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
 192  * SPD calls.
 193  */
 194
 195 struct xfrm_policy *xfrm_policy_alloc(gfp_t gfp)
 196 {
 197         struct xfrm_policy *policy;
 198
 199         policy = kzalloc(sizeof(struct xfrm_policy), gfp);
 200
 201         if (policy) {
 202                 INIT_HLIST_NODE(&policy->bydst);
 203                 INIT_HLIST_NODE(&policy->byidx);
 204                 rwlock_init(&policy->lock);
 205                 atomic_set(&policy->refcnt, 1);
 206                 setup_timer(&policy->timer, xfrm_policy_timer,
 207                                 (unsigned long)policy);
 208         }
 209         return policy;
 210 }
 211 EXPORT_SYMBOL(xfrm_policy_alloc);
 212
 213 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
 214
 215 void __xfrm_policy_destroy(struct xfrm_policy *policy)
 216 {
 217         BUG_ON(!policy->dead);
 218
 219         BUG_ON(policy->bundles);
 220
 221         if (del_timer(&policy->timer))
 222                 BUG();
 223
 224         security_xfrm_policy_free(policy);
 225         kfree(policy);
 226 }
 227 EXPORT_SYMBOL(__xfrm_policy_destroy);
 228
 229 static void xfrm_policy_gc_kill(struct xfrm_policy *policy)
 230 {
 231         struct dst_entry *dst;
 232
 233         while ((dst = policy->bundles) != NULL) {
 234                 policy->bundles = dst->next;
 235                 dst_free(dst);
 236         }
 237
 238         if (del_timer(&policy->timer))
 239                 atomic_dec(&policy->refcnt);
 240
 241         if (atomic_read(&policy->refcnt) > 1)
 242                 flow_cache_flush();
 243
 244         xfrm_pol_put(policy);
 245 }
 246
 247 static void xfrm_policy_gc_task(struct work_struct *work)
 248 {
 249         struct xfrm_policy *policy;
 250         struct hlist_node *entry, *tmp;
 251         struct hlist_head gc_list;
 252
 253         spin_lock_bh(&xfrm_policy_gc_lock);
 254         gc_list.first = xfrm_policy_gc_list.first;
 255         INIT_HLIST_HEAD(&xfrm_policy_gc_list);
 256         spin_unlock_bh(&xfrm_policy_gc_lock);
 257
 258         hlist_for_each_entry_safe(policy, entry, tmp, &gc_list, bydst)
 259                 xfrm_policy_gc_kill(policy);
 260 }
 261
 262 /* Rule must be locked. Release descentant resources, announce
 263  * entry dead. The rule must be unlinked from lists to the moment.
 264  */
 265
 266 static void xfrm_policy_kill(struct xfrm_policy *policy)
 267 {
 268         int dead;
 269
 270         write_lock_bh(&policy->lock);
 271         dead = policy->dead;
 272         policy->dead = 1;
 273         write_unlock_bh(&policy->lock);
 274
 275         if (unlikely(dead)) {
 276                 WARN_ON(1);
 277                 return;
 278         }
 279
 280         spin_lock(&xfrm_policy_gc_lock);
 281         hlist_add_head(&policy->bydst, &xfrm_policy_gc_list);
 282         spin_unlock(&xfrm_policy_gc_lock);
 283
 284         schedule_work(&xfrm_policy_gc_work);
 285 }
 286
 287 struct xfrm_policy_hash {
 288         struct hlist_head       *table;
 289         unsigned int            hmask;
 290 };
 291
 292 static struct hlist_head xfrm_policy_inexact[XFRM_POLICY_MAX*2];
 293 static struct xfrm_policy_hash xfrm_policy_bydst[XFRM_POLICY_MAX*2] __read_mostly;
 294 static struct hlist_head *xfrm_policy_byidx __read_mostly;
 295 static unsigned int xfrm_idx_hmask __read_mostly;
 296 static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
 297
 298 static inline unsigned int idx_hash(u32 index)
 299 {
 300         return __idx_hash(index, xfrm_idx_hmask);
 301 }
 302
 303 static struct hlist_head *policy_hash_bysel(struct xfrm_selector *sel, unsigned short family, int dir)
 304 {
 305         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
 306         unsigned int hash = __sel_hash(sel, family, hmask);
 307
 308         return (hash == hmask + 1 ?
 309                 &xfrm_policy_inexact[dir] :
 310                 xfrm_policy_bydst[dir].table + hash);
 311 }
 312
 313 static struct hlist_head *policy_hash_direct(xfrm_address_t *daddr, xfrm_address_t *saddr, unsigned short family, int dir)
 314 {
 315         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
 316         unsigned int hash = __addr_hash(daddr, saddr, family, hmask);
 317
 318         return xfrm_policy_bydst[dir].table + hash;
 319 }
 320
 321 static void xfrm_dst_hash_transfer(struct hlist_head *list,
 322                                    struct hlist_head *ndsttable,
 323                                    unsigned int nhashmask)
 324 {
 325         struct hlist_node *entry, *tmp;
 326         struct xfrm_policy *pol;
 327
 328         hlist_for_each_entry_safe(pol, entry, tmp, list, bydst) {
 329                 unsigned int h;
 330
 331                 h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
 332                                 pol->family, nhashmask);
 333                 hlist_add_head(&pol->bydst, ndsttable+h);
 334         }
 335 }
 336
 337 static void xfrm_idx_hash_transfer(struct hlist_head *list,
 338                                    struct hlist_head *nidxtable,
 339                                    unsigned int nhashmask)
 340 {
 341         struct hlist_node *entry, *tmp;
 342         struct xfrm_policy *pol;
 343
 344         hlist_for_each_entry_safe(pol, entry, tmp, list, byidx) {
 345                 unsigned int h;
 346
 347                 h = __idx_hash(pol->index, nhashmask);
 348                 hlist_add_head(&pol->byidx, nidxtable+h);
 349         }
 350 }
 351
 352 static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
 353 {
 354         return ((old_hmask + 1) << 1) - 1;
 355 }
 356
 357 static void xfrm_bydst_resize(int dir)
 358 {
 359         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
 360         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 361         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 362         struct hlist_head *odst = xfrm_policy_bydst[dir].table;
 363         struct hlist_head *ndst = xfrm_hash_alloc(nsize);
 364         int i;
 365
 366         if (!ndst)
 367                 return;
 368
 369         write_lock_bh(&xfrm_policy_lock);
 370
 371         for (i = hmask; i >= 0; i--)
 372                 xfrm_dst_hash_transfer(odst + i, ndst, nhashmask);
 373
 374         xfrm_policy_bydst[dir].table = ndst;
 375         xfrm_policy_bydst[dir].hmask = nhashmask;
 376
 377         write_unlock_bh(&xfrm_policy_lock);
 378
 379         xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
 380 }
 381
 382 static void xfrm_byidx_resize(int total)
 383 {
 384         unsigned int hmask = xfrm_idx_hmask;
 385         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 386         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 387         struct hlist_head *oidx = xfrm_policy_byidx;
 388         struct hlist_head *nidx = xfrm_hash_alloc(nsize);
 389         int i;
 390
 391         if (!nidx)
 392                 return;
 393
 394         write_lock_bh(&xfrm_policy_lock);
 395
 396         for (i = hmask; i >= 0; i--)
 397                 xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
 398
 399         xfrm_policy_byidx = nidx;
 400         xfrm_idx_hmask = nhashmask;
 401
 402         write_unlock_bh(&xfrm_policy_lock);
 403
 404         xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
 405 }
 406
 407 static inline int xfrm_bydst_should_resize(int dir, int *total)
 408 {
 409         unsigned int cnt = xfrm_policy_count[dir];
 410         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
 411
 412         if (total)
 413                 *total += cnt;
 414
 415         if ((hmask + 1) < xfrm_policy_hashmax &&
 416             cnt > hmask)
 417                 return 1;
 418
 419         return 0;
 420 }
 421
 422 static inline int xfrm_byidx_should_resize(int total)
 423 {
 424         unsigned int hmask = xfrm_idx_hmask;
 425
 426         if ((hmask + 1) < xfrm_policy_hashmax &&
 427             total > hmask)
 428                 return 1;
 429
 430         return 0;
 431 }
 432
 433 void xfrm_spd_getinfo(struct xfrmk_spdinfo *si)
 434 {
 435         read_lock_bh(&xfrm_policy_lock);
 436         si->incnt = xfrm_policy_count[XFRM_POLICY_IN];
 437         si->outcnt = xfrm_policy_count[XFRM_POLICY_OUT];
 438         si->fwdcnt = xfrm_policy_count[XFRM_POLICY_FWD];
 439         si->inscnt = xfrm_policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
 440         si->outscnt = xfrm_policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
 441         si->fwdscnt = xfrm_policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
 442         si->spdhcnt = xfrm_idx_hmask;
 443         si->spdhmcnt = xfrm_policy_hashmax;
 444         read_unlock_bh(&xfrm_policy_lock);
 445 }
 446 EXPORT_SYMBOL(xfrm_spd_getinfo);
 447
 448 static DEFINE_MUTEX(hash_resize_mutex);
 449 static void xfrm_hash_resize(struct work_struct *__unused)
 450 {
 451         int dir, total;
 452
 453         mutex_lock(&hash_resize_mutex);
 454
 455         total = 0;
 456         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
 457                 if (xfrm_bydst_should_resize(dir, &total))
 458                         xfrm_bydst_resize(dir);
 459         }
 460         if (xfrm_byidx_should_resize(total))
 461                 xfrm_byidx_resize(total);
 462
 463         mutex_unlock(&hash_resize_mutex);
 464 }
 465
 466 static DECLARE_WORK(xfrm_hash_work, xfrm_hash_resize);
 467
 468 /* Generate new index... KAME seems to generate them ordered by cost
 469  * of an absolute inpredictability of ordering of rules. This will not pass. */
 470 static u32 xfrm_gen_index(u8 type, int dir)
 471 {
 472         static u32 idx_generator;
 473
 474         for (;;) {
 475                 struct hlist_node *entry;
 476                 struct hlist_head *list;
 477                 struct xfrm_policy *p;
 478                 u32 idx;
 479                 int found;
 480
 481                 idx = (idx_generator | dir);
 482                 idx_generator += 8;
 483                 if (idx == 0)
 484                         idx = 8;
 485                 list = xfrm_policy_byidx + idx_hash(idx);
 486                 found = 0;
 487                 hlist_for_each_entry(p, entry, list, byidx) {
 488                         if (p->index == idx) {
 489                                 found = 1;
 490                                 break;
 491                         }
 492                 }
 493                 if (!found)
 494                         return idx;
 495         }
 496 }
 497
 498 static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
 499 {
 500         u32 *p1 = (u32 *) s1;
 501         u32 *p2 = (u32 *) s2;
 502         int len = sizeof(struct xfrm_selector) / sizeof(u32);
 503         int i;
 504
 505         for (i = 0; i < len; i++) {
 506                 if (p1[i] != p2[i])
 507                         return 1;
 508         }
 509
 510         return 0;
 511 }
 512
 513 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 514 {
 515         struct xfrm_policy *pol;
 516         struct xfrm_policy *delpol;
 517         struct hlist_head *chain;
 518         struct hlist_node *entry, *newpos;
 519         struct dst_entry *gc_list;
 520
 521         write_lock_bh(&xfrm_policy_lock);
 522         chain = policy_hash_bysel(&policy->selector, policy->family, dir);
 523         delpol = NULL;
 524         newpos = NULL;
 525         hlist_for_each_entry(pol, entry, chain, bydst) {
 526                 if (pol->type == policy->type &&
 527                     !selector_cmp(&pol->selector, &policy->selector) &&
 528                     xfrm_sec_ctx_match(pol->security, policy->security) &&
 529                     !WARN_ON(delpol)) {
 530                         if (excl) {
 531                                 write_unlock_bh(&xfrm_policy_lock);
 532                                 return -EEXIST;
 533                         }
 534                         delpol = pol;
 535                         if (policy->priority > pol->priority)
 536                                 continue;
 537                 } else if (policy->priority >= pol->priority) {
 538                         newpos = &pol->bydst;
 539                         continue;
 540                 }
 541                 if (delpol)
 542                         break;
 543         }
 544         if (newpos)
 545                 hlist_add_after(newpos, &policy->bydst);
 546         else
 547                 hlist_add_head(&policy->bydst, chain);
 548         xfrm_pol_hold(policy);
 549         xfrm_policy_count[dir]++;
 550         atomic_inc(&flow_cache_genid);
 551         if (delpol) {
 552                 hlist_del(&delpol->bydst);
 553                 hlist_del(&delpol->byidx);
 554                 xfrm_policy_count[dir]--;
 555         }
 556         policy->index = delpol ? delpol->index : xfrm_gen_index(policy->type, dir);
 557         hlist_add_head(&policy->byidx, xfrm_policy_byidx+idx_hash(policy->index));
 558         policy->curlft.add_time = get_seconds();
 559         policy->curlft.use_time = 0;
 560         if (!mod_timer(&policy->timer, jiffies + HZ))
 561                 xfrm_pol_hold(policy);
 562         write_unlock_bh(&xfrm_policy_lock);
 563
 564         if (delpol)
 565                 xfrm_policy_kill(delpol);
 566         else if (xfrm_bydst_should_resize(dir, NULL))
 567                 schedule_work(&xfrm_hash_work);
 568
 569         read_lock_bh(&xfrm_policy_lock);
 570         gc_list = NULL;
 571         entry = &policy->bydst;
 572         hlist_for_each_entry_continue(policy, entry, bydst) {
 573                 struct dst_entry *dst;
 574
 575                 write_lock(&policy->lock);
 576                 dst = policy->bundles;
 577                 if (dst) {
 578                         struct dst_entry *tail = dst;
 579                         while (tail->next)
 580                                 tail = tail->next;
 581                         tail->next = gc_list;
 582                         gc_list = dst;
 583
 584                         policy->bundles = NULL;
 585                 }
 586                 write_unlock(&policy->lock);
 587         }
 588         read_unlock_bh(&xfrm_policy_lock);
 589
 590         while (gc_list) {
 591                 struct dst_entry *dst = gc_list;
 592
 593                 gc_list = dst->next;
 594                 dst_free(dst);
 595         }
 596
 597         return 0;
 598 }
 599 EXPORT_SYMBOL(xfrm_policy_insert);
 600
 601 struct xfrm_policy *xfrm_policy_bysel_ctx(u8 type, int dir,
 602                                           struct xfrm_selector *sel,
 603                                           struct xfrm_sec_ctx *ctx, int delete,
 604                                           int *err)
 605 {
 606         struct xfrm_policy *pol, *ret;
 607         struct hlist_head *chain;
 608         struct hlist_node *entry;
 609
 610         *err = 0;
 611         write_lock_bh(&xfrm_policy_lock);
 612         chain = policy_hash_bysel(sel, sel->family, dir);
 613         ret = NULL;
 614         hlist_for_each_entry(pol, entry, chain, bydst) {
 615                 if (pol->type == type &&
 616                     !selector_cmp(sel, &pol->selector) &&
 617                     xfrm_sec_ctx_match(ctx, pol->security)) {
 618                         xfrm_pol_hold(pol);
 619                         if (delete) {
 620                                 *err = security_xfrm_policy_delete(pol);
 621                                 if (*err) {
 622                                         write_unlock_bh(&xfrm_policy_lock);
 623                                         return pol;
 624                                 }
 625                                 hlist_del(&pol->bydst);
 626                                 hlist_del(&pol->byidx);
 627                                 xfrm_policy_count[dir]--;
 628                         }
 629                         ret = pol;
 630                         break;
 631                 }
 632         }
 633         write_unlock_bh(&xfrm_policy_lock);
 634
 635         if (ret && delete) {
 636                 atomic_inc(&flow_cache_genid);
 637                 xfrm_policy_kill(ret);
 638         }
 639         return ret;
 640 }
 641 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
 642
 643 struct xfrm_policy *xfrm_policy_byid(u8 type, int dir, u32 id, int delete,
 644                                      int *err)
 645 {
 646         struct xfrm_policy *pol, *ret;
 647         struct hlist_head *chain;
 648         struct hlist_node *entry;
 649
 650         *err = -ENOENT;
 651         if (xfrm_policy_id2dir(id) != dir)
 652                 return NULL;
 653
 654         *err = 0;
 655         write_lock_bh(&xfrm_policy_lock);
 656         chain = xfrm_policy_byidx + idx_hash(id);
 657         ret = NULL;
 658         hlist_for_each_entry(pol, entry, chain, byidx) {
 659                 if (pol->type == type && pol->index == id) {
 660                         xfrm_pol_hold(pol);
 661                         if (delete) {
 662                                 *err = security_xfrm_policy_delete(pol);
 663                                 if (*err) {
 664                                         write_unlock_bh(&xfrm_policy_lock);
 665                                         return pol;
 666                                 }
 667                                 hlist_del(&pol->bydst);
 668                                 hlist_del(&pol->byidx);
 669                                 xfrm_policy_count[dir]--;
 670                         }
 671                         ret = pol;
 672                         break;
 673                 }
 674         }
 675         write_unlock_bh(&xfrm_policy_lock);
 676
 677         if (ret && delete) {
 678                 atomic_inc(&flow_cache_genid);
 679                 xfrm_policy_kill(ret);
 680         }
 681         return ret;
 682 }
 683 EXPORT_SYMBOL(xfrm_policy_byid);
 684
 685 #ifdef CONFIG_SECURITY_NETWORK_XFRM
 686 static inline int
 687 xfrm_policy_flush_secctx_check(u8 type, struct xfrm_audit *audit_info)
 688 {
 689         int dir, err = 0;
 690
 691         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 692                 struct xfrm_policy *pol;
 693                 struct hlist_node *entry;
 694                 int i;
 695
 696                 hlist_for_each_entry(pol, entry,
 697                                      &xfrm_policy_inexact[dir], bydst) {
 698                         if (pol->type != type)
 699                                 continue;
 700                         err = security_xfrm_policy_delete(pol);
 701                         if (err) {
 702                                 xfrm_audit_policy_delete(pol, 0,
 703                                                          audit_info->loginuid,
 704                                                          audit_info->secid);
 705                                 return err;
 706                         }
 707                 }
 708                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
 709                         hlist_for_each_entry(pol, entry,
 710                                              xfrm_policy_bydst[dir].table + i,
 711                                              bydst) {
 712                                 if (pol->type != type)
 713                                         continue;
 714                                 err = security_xfrm_policy_delete(pol);
 715                                 if (err) {
 716                                         xfrm_audit_policy_delete(pol, 0,
 717                                                         audit_info->loginuid,
 718                                                         audit_info->secid);
 719                                         return err;
 720                                 }
 721                         }
 722                 }
 723         }
 724         return err;
 725 }
 726 #else
 727 static inline int
 728 xfrm_policy_flush_secctx_check(u8 type, struct xfrm_audit *audit_info)
 729 {
 730         return 0;
 731 }
 732 #endif
 733
 734 int xfrm_policy_flush(u8 type, struct xfrm_audit *audit_info)
 735 {
 736         int dir, err = 0;
 737
 738         write_lock_bh(&xfrm_policy_lock);
 739
 740         err = xfrm_policy_flush_secctx_check(type, audit_info);
 741         if (err)
 742                 goto out;
 743
 744         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 745                 struct xfrm_policy *pol;
 746                 struct hlist_node *entry;
 747                 int i, killed;
 748
 749                 killed = 0;
 750         again1:
 751                 hlist_for_each_entry(pol, entry,
 752                                      &xfrm_policy_inexact[dir], bydst) {
 753                         if (pol->type != type)
 754                                 continue;
 755                         hlist_del(&pol->bydst);
 756                         hlist_del(&pol->byidx);
 757                         write_unlock_bh(&xfrm_policy_lock);
 758
 759                         xfrm_audit_policy_delete(pol, 1, audit_info->loginuid,
 760                                                  audit_info->secid);
 761
 762                         xfrm_policy_kill(pol);
 763                         killed++;
 764
 765                         write_lock_bh(&xfrm_policy_lock);
 766                         goto again1;
 767                 }
 768
 769                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
 770         again2:
 771                         hlist_for_each_entry(pol, entry,
 772                                              xfrm_policy_bydst[dir].table + i,
 773                                              bydst) {
 774                                 if (pol->type != type)
 775                                         continue;
 776                                 hlist_del(&pol->bydst);
 777                                 hlist_del(&pol->byidx);
 778                                 write_unlock_bh(&xfrm_policy_lock);
 779
 780                                 xfrm_audit_policy_delete(pol, 1,
 781                                                          audit_info->loginuid,
 782                                                          audit_info->secid);
 783                                 xfrm_policy_kill(pol);
 784                                 killed++;
 785
 786                                 write_lock_bh(&xfrm_policy_lock);
 787                                 goto again2;
 788                         }
 789                 }
 790
 791                 xfrm_policy_count[dir] -= killed;
 792         }
 793         atomic_inc(&flow_cache_genid);
 794 out:
 795         write_unlock_bh(&xfrm_policy_lock);
 796         return err;
 797 }
 798 EXPORT_SYMBOL(xfrm_policy_flush);
 799
 800 int xfrm_policy_walk(u8 type, int (*func)(struct xfrm_policy *, int, int, void*),
 801                      void *data)
 802 {
 803         struct xfrm_policy *pol, *last = NULL;
 804         struct hlist_node *entry;
 805         int dir, last_dir = 0, count, error;
 806
 807         read_lock_bh(&xfrm_policy_lock);
 808         count = 0;
 809
 810         for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
 811                 struct hlist_head *table = xfrm_policy_bydst[dir].table;
 812                 int i;
 813
 814                 hlist_for_each_entry(pol, entry,
 815                                      &xfrm_policy_inexact[dir], bydst) {
 816                         if (pol->type != type)
 817                                 continue;
 818                         if (last) {
 819                                 error = func(last, last_dir % XFRM_POLICY_MAX,
 820                                              count, data);
 821                                 if (error)
 822                                         goto out;
 823                         }
 824                         last = pol;
 825                         last_dir = dir;
 826                         count++;
 827                 }
 828                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
 829                         hlist_for_each_entry(pol, entry, table + i, bydst) {
 830                                 if (pol->type != type)
 831                                         continue;
 832                                 if (last) {
 833                                         error = func(last, last_dir % XFRM_POLICY_MAX,
 834                                                      count, data);
 835                                         if (error)
 836                                                 goto out;
 837                                 }
 838                                 last = pol;
 839                                 last_dir = dir;
 840                                 count++;
 841                         }
 842                 }
 843         }
 844         if (count == 0) {
 845                 error = -ENOENT;
 846                 goto out;
 847         }
 848         error = func(last, last_dir % XFRM_POLICY_MAX, 0, data);
 849 out:
 850         read_unlock_bh(&xfrm_policy_lock);
 851         return error;
 852 }
 853 EXPORT_SYMBOL(xfrm_policy_walk);
 854
 855 /*
 856  * Find policy to apply to this flow.
 857  *
 858  * Returns 0 if policy found, else an -errno.
 859  */
 860 static int xfrm_policy_match(struct xfrm_policy *pol, struct flowi *fl,
 861                              u8 type, u16 family, int dir)
 862 {
 863         struct xfrm_selector *sel = &pol->selector;
 864         int match, ret = -ESRCH;
 865
 866         if (pol->family != family ||
 867             pol->type != type)
 868                 return ret;
 869
 870         match = xfrm_selector_match(sel, fl, family);
 871         if (match)
 872                 ret = security_xfrm_policy_lookup(pol, fl->secid, dir);
 873
 874         return ret;
 875 }
 876
 877 static struct xfrm_policy *xfrm_policy_lookup_bytype(u8 type, struct flowi *fl,
 878                                                      u16 family, u8 dir)
 879 {
 880         int err;
 881         struct xfrm_policy *pol, *ret;
 882         xfrm_address_t *daddr, *saddr;
 883         struct hlist_node *entry;
 884         struct hlist_head *chain;
 885         u32 priority = ~0U;
 886
 887         daddr = xfrm_flowi_daddr(fl, family);
 888         saddr = xfrm_flowi_saddr(fl, family);
 889         if (unlikely(!daddr || !saddr))
 890                 return NULL;
 891
 892         read_lock_bh(&xfrm_policy_lock);
 893         chain = policy_hash_direct(daddr, saddr, family, dir);
 894         ret = NULL;
 895         hlist_for_each_entry(pol, entry, chain, bydst) {
 896                 err = xfrm_policy_match(pol, fl, type, family, dir);
 897                 if (err) {
 898                         if (err == -ESRCH)
 899                                 continue;
 900                         else {
 901                                 ret = ERR_PTR(err);
 902                                 goto fail;
 903                         }
 904                 } else {
 905                         ret = pol;
 906                         priority = ret->priority;
 907                         break;
 908                 }
 909         }
 910         chain = &xfrm_policy_inexact[dir];
 911         hlist_for_each_entry(pol, entry, chain, bydst) {
 912                 err = xfrm_policy_match(pol, fl, type, family, dir);
 913                 if (err) {
 914                         if (err == -ESRCH)
 915                                 continue;
 916                         else {
 917                                 ret = ERR_PTR(err);
 918                                 goto fail;
 919                         }
 920                 } else if (pol->priority < priority) {
 921                         ret = pol;
 922                         break;
 923                 }
 924         }
 925         if (ret)
 926                 xfrm_pol_hold(ret);
 927 fail:
 928         read_unlock_bh(&xfrm_policy_lock);
 929
 930         return ret;
 931 }
 932
 933 static int xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
 934                                void **objp, atomic_t **obj_refp)
 935 {
 936         struct xfrm_policy *pol;
 937         int err = 0;
 938
 939 #ifdef CONFIG_XFRM_SUB_POLICY
 940         pol = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_SUB, fl, family, dir);
 941         if (IS_ERR(pol)) {
 942                 err = PTR_ERR(pol);
 943                 pol = NULL;
 944         }
 945         if (pol || err)
 946                 goto end;
 947 #endif
 948         pol = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN, fl, family, dir);
 949         if (IS_ERR(pol)) {
 950                 err = PTR_ERR(pol);
 951                 pol = NULL;
 952         }
 953 #ifdef CONFIG_XFRM_SUB_POLICY
 954 end:
 955 #endif
 956         if ((*objp = (void *) pol) != NULL)
 957                 *obj_refp = &pol->refcnt;
 958         return err;
 959 }
 960
 961 static inline int policy_to_flow_dir(int dir)
 962 {
 963         if (XFRM_POLICY_IN == FLOW_DIR_IN &&
 964             XFRM_POLICY_OUT == FLOW_DIR_OUT &&
 965             XFRM_POLICY_FWD == FLOW_DIR_FWD)
 966                 return dir;
 967         switch (dir) {
 968         default:
 969         case XFRM_POLICY_IN:
 970                 return FLOW_DIR_IN;
 971         case XFRM_POLICY_OUT:
 972                 return FLOW_DIR_OUT;
 973         case XFRM_POLICY_FWD:
 974                 return FLOW_DIR_FWD;
 975         }
 976 }
 977
 978 static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl)
 979 {
 980         struct xfrm_policy *pol;
 981
 982         read_lock_bh(&xfrm_policy_lock);
 983         if ((pol = sk->sk_policy[dir]) != NULL) {
 984                 int match = xfrm_selector_match(&pol->selector, fl,
 985                                                 sk->sk_family);
 986                 int err = 0;
 987
 988                 if (match) {
 989                         err = security_xfrm_policy_lookup(pol, fl->secid,
 990                                         policy_to_flow_dir(dir));
 991                         if (!err)
 992                                 xfrm_pol_hold(pol);
 993                         else if (err == -ESRCH)
 994                                 pol = NULL;
 995                         else
 996                                 pol = ERR_PTR(err);
 997                 } else
 998                         pol = NULL;
 999         }
1000         read_unlock_bh(&xfrm_policy_lock);
1001         return pol;
1002 }
1003
1004 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
1005 {
1006         struct hlist_head *chain = policy_hash_bysel(&pol->selector,
1007                                                      pol->family, dir);
1008
1009         hlist_add_head(&pol->bydst, chain);
1010         hlist_add_head(&pol->byidx, xfrm_policy_byidx+idx_hash(pol->index));
1011         xfrm_policy_count[dir]++;
1012         xfrm_pol_hold(pol);
1013
1014         if (xfrm_bydst_should_resize(dir, NULL))
1015                 schedule_work(&xfrm_hash_work);
1016 }
1017
1018 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
1019                                                 int dir)
1020 {
1021         if (hlist_unhashed(&pol->bydst))
1022                 return NULL;
1023
1024         hlist_del(&pol->bydst);
1025         hlist_del(&pol->byidx);
1026         xfrm_policy_count[dir]--;
1027
1028         return pol;
1029 }
1030
1031 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
1032 {
1033         write_lock_bh(&xfrm_policy_lock);
1034         pol = __xfrm_policy_unlink(pol, dir);
1035         write_unlock_bh(&xfrm_policy_lock);
1036         if (pol) {
1037                 if (dir < XFRM_POLICY_MAX)
1038                         atomic_inc(&flow_cache_genid);
1039                 xfrm_policy_kill(pol);
1040                 return 0;
1041         }
1042         return -ENOENT;
1043 }
1044 EXPORT_SYMBOL(xfrm_policy_delete);
1045
1046 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
1047 {
1048         struct xfrm_policy *old_pol;
1049
1050 #ifdef CONFIG_XFRM_SUB_POLICY
1051         if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
1052                 return -EINVAL;
1053 #endif
1054
1055         write_lock_bh(&xfrm_policy_lock);
1056         old_pol = sk->sk_policy[dir];
1057         sk->sk_policy[dir] = pol;
1058         if (pol) {
1059                 pol->curlft.add_time = get_seconds();
1060                 pol->index = xfrm_gen_index(pol->type, XFRM_POLICY_MAX+dir);
1061                 __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
1062         }
1063         if (old_pol)
1064                 __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
1065         write_unlock_bh(&xfrm_policy_lock);
1066
1067         if (old_pol) {
1068                 xfrm_policy_kill(old_pol);
1069         }
1070         return 0;
1071 }
1072
1073 static struct xfrm_policy *clone_policy(struct xfrm_policy *old, int dir)
1074 {
1075         struct xfrm_policy *newp = xfrm_policy_alloc(GFP_ATOMIC);
1076
1077         if (newp) {
1078                 newp->selector = old->selector;
1079                 if (security_xfrm_policy_clone(old, newp)) {
1080                         kfree(newp);
1081                         return NULL;  /* ENOMEM */
1082                 }
1083                 newp->lft = old->lft;
1084                 newp->curlft = old->curlft;
1085                 newp->action = old->action;
1086                 newp->flags = old->flags;
1087                 newp->xfrm_nr = old->xfrm_nr;
1088                 newp->index = old->index;
1089                 newp->type = old->type;
1090                 memcpy(newp->xfrm_vec, old->xfrm_vec,
1091                        newp->xfrm_nr*sizeof(struct xfrm_tmpl));
1092                 write_lock_bh(&xfrm_policy_lock);
1093                 __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir);
1094                 write_unlock_bh(&xfrm_policy_lock);
1095                 xfrm_pol_put(newp);
1096         }
1097         return newp;
1098 }
1099
1100 int __xfrm_sk_clone_policy(struct sock *sk)
1101 {
1102         struct xfrm_policy *p0 = sk->sk_policy[0],
1103                            *p1 = sk->sk_policy[1];
1104
1105         sk->sk_policy[0] = sk->sk_policy[1] = NULL;
1106         if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL)
1107                 return -ENOMEM;
1108         if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL)
1109                 return -ENOMEM;
1110         return 0;
1111 }
1112
1113 static int
1114 xfrm_get_saddr(xfrm_address_t *local, xfrm_address_t *remote,
1115                unsigned short family)
1116 {
1117         int err;
1118         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1119
1120         if (unlikely(afinfo == NULL))
1121                 return -EINVAL;
1122         err = afinfo->get_saddr(local, remote);
1123         xfrm_policy_put_afinfo(afinfo);
1124         return err;
1125 }
1126
1127 /* Resolve list of templates for the flow, given policy. */
1128
1129 static int
1130 xfrm_tmpl_resolve_one(struct xfrm_policy *policy, struct flowi *fl,
1131                       struct xfrm_state **xfrm,
1132                       unsigned short family)
1133 {
1134         int nx;
1135         int i, error;
1136         xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
1137         xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
1138         xfrm_address_t tmp;
1139
1140         for (nx=0, i = 0; i < policy->xfrm_nr; i++) {
1141                 struct xfrm_state *x;
1142                 xfrm_address_t *remote = daddr;
1143                 xfrm_address_t *local  = saddr;
1144                 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
1145
1146                 if (tmpl->mode == XFRM_MODE_TUNNEL ||
1147                     tmpl->mode == XFRM_MODE_BEET) {
1148                         remote = &tmpl->id.daddr;
1149                         local = &tmpl->saddr;
1150                         family = tmpl->encap_family;
1151                         if (xfrm_addr_any(local, family)) {
1152                                 error = xfrm_get_saddr(&tmp, remote, family);
1153                                 if (error)
1154                                         goto fail;
1155                                 local = &tmp;
1156                         }
1157                 }
1158
1159                 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
1160
1161                 if (x && x->km.state == XFRM_STATE_VALID) {
1162                         xfrm[nx++] = x;
1163                         daddr = remote;
1164                         saddr = local;
1165                         continue;
1166                 }
1167                 if (x) {
1168                         error = (x->km.state == XFRM_STATE_ERROR ?
1169                                  -EINVAL : -EAGAIN);
1170                         xfrm_state_put(x);
1171                 }
1172
1173                 if (!tmpl->optional)
1174                         goto fail;
1175         }
1176         return nx;
1177
1178 fail:
1179         for (nx--; nx>=0; nx--)
1180                 xfrm_state_put(xfrm[nx]);
1181         return error;
1182 }
1183
1184 static int
1185 xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, struct flowi *fl,
1186                   struct xfrm_state **xfrm,
1187                   unsigned short family)
1188 {
1189         struct xfrm_state *tp[XFRM_MAX_DEPTH];
1190         struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
1191         int cnx = 0;
1192         int error;
1193         int ret;
1194         int i;
1195
1196         for (i = 0; i < npols; i++) {
1197                 if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
1198                         error = -ENOBUFS;
1199                         goto fail;
1200                 }
1201
1202                 ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
1203                 if (ret < 0) {
1204                         error = ret;
1205                         goto fail;
1206                 } else
1207                         cnx += ret;
1208         }
1209
1210         /* found states are sorted for outbound processing */
1211         if (npols > 1)
1212                 xfrm_state_sort(xfrm, tpp, cnx, family);
1213
1214         return cnx;
1215
1216  fail:
1217         for (cnx--; cnx>=0; cnx--)
1218                 xfrm_state_put(tpp[cnx]);
1219         return error;
1220
1221 }
1222
1223 /* Check that the bundle accepts the flow and its components are
1224  * still valid.
1225  */
1226
1227 static struct dst_entry *
1228 xfrm_find_bundle(struct flowi *fl, struct xfrm_policy *policy, unsigned short family)
1229 {
1230         struct dst_entry *x;
1231         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1232         if (unlikely(afinfo == NULL))
1233                 return ERR_PTR(-EINVAL);
1234         x = afinfo->find_bundle(fl, policy);
1235         xfrm_policy_put_afinfo(afinfo);
1236         return x;
1237 }
1238
1239 static inline int xfrm_get_tos(struct flowi *fl, int family)
1240 {
1241         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1242         int tos;
1243
1244         if (!afinfo)
1245                 return -EINVAL;
1246
1247         tos = afinfo->get_tos(fl);
1248
1249         xfrm_policy_put_afinfo(afinfo);
1250
1251         return tos;
1252 }
1253
1254 static inline struct xfrm_dst *xfrm_alloc_dst(int family)
1255 {
1256         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1257         struct xfrm_dst *xdst;
1258
1259         if (!afinfo)
1260                 return ERR_PTR(-EINVAL);
1261
1262         xdst = dst_alloc(afinfo->dst_ops) ?: ERR_PTR(-ENOBUFS);
1263
1264         xfrm_policy_put_afinfo(afinfo);
1265
1266         return xdst;
1267 }
1268
1269 static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev)
1270 {
1271         struct xfrm_policy_afinfo *afinfo =
1272                 xfrm_policy_get_afinfo(xdst->u.dst.ops->family);
1273         int err;
1274
1275         if (!afinfo)
1276                 return -EINVAL;
1277
1278         err = afinfo->fill_dst(xdst, dev);
1279
1280         xfrm_policy_put_afinfo(afinfo);
1281
1282         return err;
1283 }
1284
1285 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
1286  * all the metrics... Shortly, bundle a bundle.
1287  */
1288
1289 static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
1290                                             struct xfrm_state **xfrm, int nx,
1291                                             struct flowi *fl,
1292                                             struct dst_entry *dst)
1293 {
1294         unsigned long now = jiffies;
1295         struct net_device *dev;
1296         struct dst_entry *dst_prev = NULL;
1297         struct dst_entry *dst0 = NULL;
1298         int i = 0;
1299         int err;
1300         int header_len = 0;
1301         int trailer_len = 0;
1302         int tos;
1303         int family = policy->selector.family;
1304
1305         tos = xfrm_get_tos(fl, family);
1306         err = tos;
1307         if (tos < 0)
1308                 goto put_states;
1309
1310         dst_hold(dst);
1311
1312         for (; i < nx; i++) {
1313                 struct xfrm_dst *xdst = xfrm_alloc_dst(family);
1314                 struct dst_entry *dst1 = &xdst->u.dst;
1315
1316                 err = PTR_ERR(xdst);
1317                 if (IS_ERR(xdst)) {
1318                         dst_release(dst);
1319                         goto put_states;
1320                 }
1321
1322                 if (!dst_prev)
1323                         dst0 = dst1;
1324                 else {
1325                         dst_prev->child = dst_clone(dst1);
1326                         dst1->flags |= DST_NOHASH;
1327                 }
1328
1329                 xdst->route = dst;
1330                 memcpy(&dst1->metrics, &dst->metrics, sizeof(dst->metrics));
1331
1332                 if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
1333                         family = xfrm[i]->props.family;
1334                         dst = xfrm_dst_lookup(xfrm[i], tos, family);
1335                         err = PTR_ERR(dst);
1336                         if (IS_ERR(dst))
1337                                 goto put_states;
1338                 } else
1339                         dst_hold(dst);
1340
1341                 dst1->xfrm = xfrm[i];
1342                 xdst->genid = xfrm[i]->genid;
1343
1344                 dst1->obsolete = -1;
1345                 dst1->flags |= DST_HOST;
1346                 dst1->lastuse = now;
1347
1348                 dst1->input = dst_discard;
1349                 dst1->output = xfrm[i]->outer_mode->afinfo->output;
1350
1351                 dst1->next = dst_prev;
1352                 dst_prev = dst1;
1353
1354                 header_len += xfrm[i]->props.header_len;
1355                 trailer_len += xfrm[i]->props.trailer_len;
1356         }
1357
1358         dst_prev->child = dst;
1359         dst0->path = dst;
1360
1361         err = -ENODEV;
1362         dev = dst->dev;
1363         if (!dev)
1364                 goto free_dst;
1365
1366         /* Copy neighbout for reachability confirmation */
1367         dst0->neighbour = neigh_clone(dst->neighbour);
1368
1369         xfrm_init_pmtu(dst_prev);
1370
1371         for (dst_prev = dst0; dst_prev != dst; dst_prev = dst_prev->child) {
1372                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst_prev;
1373
1374                 err = xfrm_fill_dst(xdst, dev);
1375                 if (err)
1376                         goto free_dst;
1377
1378                 dst_prev->header_len = header_len;
1379                 dst_prev->trailer_len = trailer_len;
1380                 header_len -= xdst->u.dst.xfrm->props.header_len;
1381                 trailer_len -= xdst->u.dst.xfrm->props.trailer_len;
1382         }
1383
1384 out:
1385         return dst0;
1386
1387 put_states:
1388         for (; i < nx; i++)
1389                 xfrm_state_put(xfrm[i]);
1390 free_dst:
1391         if (dst0)
1392                 dst_free(dst0);
1393         dst0 = ERR_PTR(err);
1394         goto out;
1395 }
1396
1397 static int inline
1398 xfrm_dst_alloc_copy(void **target, void *src, int size)
1399 {
1400         if (!*target) {
1401                 *target = kmalloc(size, GFP_ATOMIC);
1402                 if (!*target)
1403                         return -ENOMEM;
1404         }
1405         memcpy(*target, src, size);
1406         return 0;
1407 }
1408
1409 static int inline
1410 xfrm_dst_update_parent(struct dst_entry *dst, struct xfrm_selector *sel)
1411 {
1412 #ifdef CONFIG_XFRM_SUB_POLICY
1413         struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1414         return xfrm_dst_alloc_copy((void **)&(xdst->partner),
1415                                    sel, sizeof(*sel));
1416 #else
1417         return 0;
1418 #endif
1419 }
1420
1421 static int inline
1422 xfrm_dst_update_origin(struct dst_entry *dst, struct flowi *fl)
1423 {
1424 #ifdef CONFIG_XFRM_SUB_POLICY
1425         struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1426         return xfrm_dst_alloc_copy((void **)&(xdst->origin), fl, sizeof(*fl));
1427 #else
1428         return 0;
1429 #endif
1430 }
1431
1432 static int stale_bundle(struct dst_entry *dst);
1433
1434 /* Main function: finds/creates a bundle for given flow.
1435  *
1436  * At the moment we eat a raw IP route. Mostly to speed up lookups
1437  * on interfaces with disabled IPsec.
1438  */
1439 int __xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
1440                   struct sock *sk, int flags)
1441 {
1442         struct xfrm_policy *policy;
1443         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1444         int npols;
1445         int pol_dead;
1446         int xfrm_nr;
1447         int pi;
1448         struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
1449         struct dst_entry *dst, *dst_orig = *dst_p;
1450         int nx = 0;
1451         int err;
1452         u32 genid;
1453         u16 family;
1454         u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
1455
1456 restart:
1457         genid = atomic_read(&flow_cache_genid);
1458         policy = NULL;
1459         for (pi = 0; pi < ARRAY_SIZE(pols); pi++)
1460                 pols[pi] = NULL;
1461         npols = 0;
1462         pol_dead = 0;
1463         xfrm_nr = 0;
1464
1465         if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
1466                 policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
1467                 err = PTR_ERR(policy);
1468                 if (IS_ERR(policy))
1469                         goto dropdst;
1470         }
1471
1472         if (!policy) {
1473                 /* To accelerate a bit...  */
1474                 if ((dst_orig->flags & DST_NOXFRM) ||
1475                     !xfrm_policy_count[XFRM_POLICY_OUT])
1476                         return 0;
1477
1478                 policy = flow_cache_lookup(fl, dst_orig->ops->family,
1479                                            dir, xfrm_policy_lookup);
1480                 err = PTR_ERR(policy);
1481                 if (IS_ERR(policy))
1482                         goto dropdst;
1483         }
1484
1485         if (!policy)
1486                 return 0;
1487
1488         family = dst_orig->ops->family;
1489         policy->curlft.use_time = get_seconds();
1490         pols[0] = policy;
1491         npols ++;
1492         xfrm_nr += pols[0]->xfrm_nr;
1493
1494         switch (policy->action) {
1495         default:
1496         case XFRM_POLICY_BLOCK:
1497                 /* Prohibit the flow */
1498                 err = -EPERM;
1499                 goto error;
1500
1501         case XFRM_POLICY_ALLOW:
1502 #ifndef CONFIG_XFRM_SUB_POLICY
1503                 if (policy->xfrm_nr == 0) {
1504                         /* Flow passes not transformed. */
1505                         xfrm_pol_put(policy);
1506                         return 0;
1507                 }
1508 #endif
1509
1510                 /* Try to find matching bundle.
1511                  *
1512                  * LATER: help from flow cache. It is optional, this
1513                  * is required only for output policy.
1514                  */
1515                 dst = xfrm_find_bundle(fl, policy, family);
1516                 if (IS_ERR(dst)) {
1517                         err = PTR_ERR(dst);
1518                         goto error;
1519                 }
1520
1521                 if (dst)
1522                         break;
1523
1524 #ifdef CONFIG_XFRM_SUB_POLICY
1525                 if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1526                         pols[1] = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN,
1527                                                             fl, family,
1528                                                             XFRM_POLICY_OUT);
1529                         if (pols[1]) {
1530                                 if (IS_ERR(pols[1])) {
1531                                         err = PTR_ERR(pols[1]);
1532                                         goto error;
1533                                 }
1534                                 if (pols[1]->action == XFRM_POLICY_BLOCK) {
1535                                         err = -EPERM;
1536                                         goto error;
1537                                 }
1538                                 npols ++;
1539                                 xfrm_nr += pols[1]->xfrm_nr;
1540                         }
1541                 }
1542
1543                 /*
1544                  * Because neither flowi nor bundle information knows about
1545                  * transformation template size. On more than one policy usage
1546                  * we can realize whether all of them is bypass or not after
1547                  * they are searched. See above not-transformed bypass
1548                  * is surrounded by non-sub policy configuration, too.
1549                  */
1550                 if (xfrm_nr == 0) {
1551                         /* Flow passes not transformed. */
1552                         xfrm_pols_put(pols, npols);
1553                         return 0;
1554                 }
1555
1556 #endif
1557                 nx = xfrm_tmpl_resolve(pols, npols, fl, xfrm, family);
1558
1559                 if (unlikely(nx<0)) {
1560                         err = nx;
1561                         if (err == -EAGAIN && sysctl_xfrm_larval_drop) {
1562                                 /* EREMOTE tells the caller to generate
1563                                  * a one-shot blackhole route.
1564                                  */
1565                                 xfrm_pol_put(policy);
1566                                 return -EREMOTE;
1567                         }
1568                         if (err == -EAGAIN && (flags & XFRM_LOOKUP_WAIT)) {
1569                                 DECLARE_WAITQUEUE(wait, current);
1570
1571                                 add_wait_queue(&km_waitq, &wait);
1572                                 set_current_state(TASK_INTERRUPTIBLE);
1573                                 schedule();
1574                                 set_current_state(TASK_RUNNING);
1575                                 remove_wait_queue(&km_waitq, &wait);
1576
1577                                 nx = xfrm_tmpl_resolve(pols, npols, fl, xfrm, family);
1578
1579                                 if (nx == -EAGAIN && signal_pending(current)) {
1580                                         err = -ERESTART;
1581                                         goto error;
1582                                 }
1583                                 if (nx == -EAGAIN ||
1584                                     genid != atomic_read(&flow_cache_genid)) {
1585                                         xfrm_pols_put(pols, npols);
1586                                         goto restart;
1587                                 }
1588                                 err = nx;
1589                         }
1590                         if (err < 0)
1591                                 goto error;
1592                 }
1593                 if (nx == 0) {
1594                         /* Flow passes not transformed. */
1595                         xfrm_pols_put(pols, npols);
1596                         return 0;
1597                 }
1598
1599                 dst = xfrm_bundle_create(policy, xfrm, nx, fl, dst_orig);
1600                 err = PTR_ERR(dst);
1601                 if (IS_ERR(dst))
1602                         goto error;
1603
1604                 for (pi = 0; pi < npols; pi++) {
1605                         read_lock_bh(&pols[pi]->lock);
1606                         pol_dead |= pols[pi]->dead;
1607                         read_unlock_bh(&pols[pi]->lock);
1608                 }
1609
1610                 write_lock_bh(&policy->lock);
1611                 if (unlikely(pol_dead || stale_bundle(dst))) {
1612                         /* Wow! While we worked on resolving, this
1613                          * policy has gone. Retry. It is not paranoia,
1614                          * we just cannot enlist new bundle to dead object.
1615                          * We can't enlist stable bundles either.
1616                          */
1617                         write_unlock_bh(&policy->lock);
1618                         if (dst)
1619                                 dst_free(dst);
1620
1621                         err = -EHOSTUNREACH;
1622                         goto error;
1623                 }
1624
1625                 if (npols > 1)
1626                         err = xfrm_dst_update_parent(dst, &pols[1]->selector);
1627                 else
1628                         err = xfrm_dst_update_origin(dst, fl);
1629                 if (unlikely(err)) {
1630                         write_unlock_bh(&policy->lock);
1631                         if (dst)
1632                                 dst_free(dst);
1633                         goto error;
1634                 }
1635
1636                 dst->next = policy->bundles;
1637                 policy->bundles = dst;
1638                 dst_hold(dst);
1639                 write_unlock_bh(&policy->lock);
1640         }
1641         *dst_p = dst;
1642         dst_release(dst_orig);
1643         xfrm_pols_put(pols, npols);
1644         return 0;
1645
1646 error:
1647         xfrm_pols_put(pols, npols);
1648 dropdst:
1649         dst_release(dst_orig);
1650         *dst_p = NULL;
1651         return err;
1652 }
1653 EXPORT_SYMBOL(__xfrm_lookup);
1654
1655 int xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
1656                 struct sock *sk, int flags)
1657 {
1658         int err = __xfrm_lookup(dst_p, fl, sk, flags);
1659
1660         if (err == -EREMOTE) {
1661                 dst_release(*dst_p);
1662                 *dst_p = NULL;
1663                 err = -EAGAIN;
1664         }
1665
1666         return err;
1667 }
1668 EXPORT_SYMBOL(xfrm_lookup);
1669
1670 static inline int
1671 xfrm_secpath_reject(int idx, struct sk_buff *skb, struct flowi *fl)
1672 {
1673         struct xfrm_state *x;
1674
1675         if (!skb->sp || idx < 0 || idx >= skb->sp->len)
1676                 return 0;
1677         x = skb->sp->xvec[idx];
1678         if (!x->type->reject)
1679                 return 0;
1680         return x->type->reject(x, skb, fl);
1681 }
1682
1683 /* When skb is transformed back to its "native" form, we have to
1684  * check policy restrictions. At the moment we make this in maximally
1685  * stupid way. Shame on me. :-) Of course, connected sockets must
1686  * have policy cached at them.
1687  */
1688
1689 static inline int
1690 xfrm_state_ok(struct xfrm_tmpl *tmpl, struct xfrm_state *x,
1691               unsigned short family)
1692 {
1693         if (xfrm_state_kern(x))
1694                 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
1695         return  x->id.proto == tmpl->id.proto &&
1696                 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
1697                 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
1698                 x->props.mode == tmpl->mode &&
1699                 ((tmpl->aalgos & (1<<x->props.aalgo)) ||
1700                  !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
1701                 !(x->props.mode != XFRM_MODE_TRANSPORT &&
1702                   xfrm_state_addr_cmp(tmpl, x, family));
1703 }
1704
1705 /*
1706  * 0 or more than 0 is returned when validation is succeeded (either bypass
1707  * because of optional transport mode, or next index of the mathced secpath
1708  * state with the template.
1709  * -1 is returned when no matching template is found.
1710  * Otherwise "-2 - errored_index" is returned.
1711  */
1712 static inline int
1713 xfrm_policy_ok(struct xfrm_tmpl *tmpl, struct sec_path *sp, int start,
1714                unsigned short family)
1715 {
1716         int idx = start;
1717
1718         if (tmpl->optional) {
1719                 if (tmpl->mode == XFRM_MODE_TRANSPORT)
1720                         return start;
1721         } else
1722                 start = -1;
1723         for (; idx < sp->len; idx++) {
1724                 if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
1725                         return ++idx;
1726                 if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
1727                         if (start == -1)
1728                                 start = -2-idx;
1729                         break;
1730                 }
1731         }
1732         return start;
1733 }
1734
1735 int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
1736                           unsigned int family, int reverse)
1737 {
1738         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1739         int err;
1740
1741         if (unlikely(afinfo == NULL))
1742                 return -EAFNOSUPPORT;
1743
1744         afinfo->decode_session(skb, fl, reverse);
1745         err = security_xfrm_decode_session(skb, &fl->secid);
1746         xfrm_policy_put_afinfo(afinfo);
1747         return err;
1748 }
1749 EXPORT_SYMBOL(__xfrm_decode_session);
1750
1751 static inline int secpath_has_nontransport(struct sec_path *sp, int k, int *idxp)
1752 {
1753         for (; k < sp->len; k++) {
1754                 if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
1755                         *idxp = k;
1756                         return 1;
1757                 }
1758         }
1759
1760         return 0;
1761 }
1762
1763 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
1764                         unsigned short family)
1765 {
1766         struct xfrm_policy *pol;
1767         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1768         int npols = 0;
1769         int xfrm_nr;
1770         int pi;
1771         int reverse;
1772         struct flowi fl;
1773         u8 fl_dir;
1774         int xerr_idx = -1;
1775
1776         reverse = dir & ~XFRM_POLICY_MASK;
1777         dir &= XFRM_POLICY_MASK;
1778         fl_dir = policy_to_flow_dir(dir);
1779
1780         if (__xfrm_decode_session(skb, &fl, family, reverse) < 0)
1781                 return 0;
1782         nf_nat_decode_session(skb, &fl, family);
1783
1784         /* First, check used SA against their selectors. */
1785         if (skb->sp) {
1786                 int i;
1787
1788                 for (i=skb->sp->len-1; i>=0; i--) {
1789                         struct xfrm_state *x = skb->sp->xvec[i];
1790                         if (!xfrm_selector_match(&x->sel, &fl, family))
1791                                 return 0;
1792                 }
1793         }
1794
1795         pol = NULL;
1796         if (sk && sk->sk_policy[dir]) {
1797                 pol = xfrm_sk_policy_lookup(sk, dir, &fl);
1798                 if (IS_ERR(pol))
1799                         return 0;
1800         }
1801
1802         if (!pol)
1803                 pol = flow_cache_lookup(&fl, family, fl_dir,
1804                                         xfrm_policy_lookup);
1805
1806         if (IS_ERR(pol))
1807                 return 0;
1808
1809         if (!pol) {
1810                 if (skb->sp && secpath_has_nontransport(skb->sp, 0, &xerr_idx)) {
1811                         xfrm_secpath_reject(xerr_idx, skb, &fl);
1812                         return 0;
1813                 }
1814                 return 1;
1815         }
1816
1817         pol->curlft.use_time = get_seconds();
1818
1819         pols[0] = pol;
1820         npols ++;
1821 #ifdef CONFIG_XFRM_SUB_POLICY
1822         if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1823                 pols[1] = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN,
1824                                                     &fl, family,
1825                                                     XFRM_POLICY_IN);
1826                 if (pols[1]) {
1827                         if (IS_ERR(pols[1]))
1828                                 return 0;
1829                         pols[1]->curlft.use_time = get_seconds();
1830                         npols ++;
1831                 }
1832         }
1833 #endif
1834
1835         if (pol->action == XFRM_POLICY_ALLOW) {
1836                 struct sec_path *sp;
1837                 static struct sec_path dummy;
1838                 struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
1839                 struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
1840                 struct xfrm_tmpl **tpp = tp;
1841                 int ti = 0;
1842                 int i, k;
1843
1844                 if ((sp = skb->sp) == NULL)
1845                         sp = &dummy;
1846
1847                 for (pi = 0; pi < npols; pi++) {
1848                         if (pols[pi] != pol &&
1849                             pols[pi]->action != XFRM_POLICY_ALLOW)
1850                                 goto reject;
1851                         if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH)
1852                                 goto reject_error;
1853                         for (i = 0; i < pols[pi]->xfrm_nr; i++)
1854                                 tpp[ti++] = &pols[pi]->xfrm_vec[i];
1855                 }
1856                 xfrm_nr = ti;
1857                 if (npols > 1) {
1858                         xfrm_tmpl_sort(stp, tpp, xfrm_nr, family);
1859                         tpp = stp;
1860                 }
1861
1862                 /* For each tunnel xfrm, find the first matching tmpl.
1863                  * For each tmpl before that, find corresponding xfrm.
1864                  * Order is _important_. Later we will implement
1865                  * some barriers, but at the moment barriers
1866                  * are implied between each two transformations.
1867                  */
1868                 for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
1869                         k = xfrm_policy_ok(tpp[i], sp, k, family);
1870                         if (k < 0) {
1871                                 if (k < -1)
1872                                         /* "-2 - errored_index" returned */
1873                                         xerr_idx = -(2+k);
1874                                 goto reject;
1875                         }
1876                 }
1877
1878                 if (secpath_has_nontransport(sp, k, &xerr_idx))
1879                         goto reject;
1880
1881                 xfrm_pols_put(pols, npols);
1882                 return 1;
1883         }
1884
1885 reject:
1886         xfrm_secpath_reject(xerr_idx, skb, &fl);
1887 reject_error:
1888         xfrm_pols_put(pols, npols);
1889         return 0;
1890 }
1891 EXPORT_SYMBOL(__xfrm_policy_check);
1892
1893 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
1894 {
1895         struct flowi fl;
1896
1897         if (xfrm_decode_session(skb, &fl, family) < 0)
1898                 return 0;
1899
1900         return xfrm_lookup(&skb->dst, &fl, NULL, 0) == 0;
1901 }
1902 EXPORT_SYMBOL(__xfrm_route_forward);
1903
1904 /* Optimize later using cookies and generation ids. */
1905
1906 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
1907 {
1908         /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
1909          * to "-1" to force all XFRM destinations to get validated by
1910          * dst_ops->check on every use.  We do this because when a
1911          * normal route referenced by an XFRM dst is obsoleted we do
1912          * not go looking around for all parent referencing XFRM dsts
1913          * so that we can invalidate them.  It is just too much work.
1914          * Instead we make the checks here on every use.  For example:
1915          *
1916          *      XFRM dst A --> IPv4 dst X
1917          *
1918          * X is the "xdst->route" of A (X is also the "dst->path" of A
1919          * in this example).  If X is marked obsolete, "A" will not
1920          * notice.  That's what we are validating here via the
1921          * stale_bundle() check.
1922          *
1923          * When a policy's bundle is pruned, we dst_free() the XFRM
1924          * dst which causes it's ->obsolete field to be set to a
1925          * positive non-zero integer.  If an XFRM dst has been pruned
1926          * like this, we want to force a new route lookup.
1927          */
1928         if (dst->obsolete < 0 && !stale_bundle(dst))
1929                 return dst;
1930
1931         return NULL;
1932 }
1933
1934 static int stale_bundle(struct dst_entry *dst)
1935 {
1936         return !xfrm_bundle_ok(NULL, (struct xfrm_dst *)dst, NULL, AF_UNSPEC, 0);
1937 }
1938
1939 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
1940 {
1941         while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
1942                 dst->dev = dev->nd_net->loopback_dev;
1943                 dev_hold(dst->dev);
1944                 dev_put(dev);
1945         }
1946 }
1947 EXPORT_SYMBOL(xfrm_dst_ifdown);
1948
1949 static void xfrm_link_failure(struct sk_buff *skb)
1950 {
1951         /* Impossible. Such dst must be popped before reaches point of failure. */
1952         return;
1953 }
1954
1955 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
1956 {
1957         if (dst) {
1958                 if (dst->obsolete) {
1959                         dst_release(dst);
1960                         dst = NULL;
1961                 }
1962         }
1963         return dst;
1964 }
1965
1966 static void prune_one_bundle(struct xfrm_policy *pol, int (*func)(struct dst_entry *), struct dst_entry **gc_list_p)
1967 {
1968         struct dst_entry *dst, **dstp;
1969
1970         write_lock(&pol->lock);
1971         dstp = &pol->bundles;
1972         while ((dst=*dstp) != NULL) {
1973                 if (func(dst)) {
1974                         *dstp = dst->next;
1975                         dst->next = *gc_list_p;
1976                         *gc_list_p = dst;
1977                 } else {
1978                         dstp = &dst->next;
1979                 }
1980         }
1981         write_unlock(&pol->lock);
1982 }
1983
1984 static void xfrm_prune_bundles(int (*func)(struct dst_entry *))
1985 {
1986         struct dst_entry *gc_list = NULL;
1987         int dir;
1988
1989         read_lock_bh(&xfrm_policy_lock);
1990         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
1991                 struct xfrm_policy *pol;
1992                 struct hlist_node *entry;
1993                 struct hlist_head *table;
1994                 int i;
1995
1996                 hlist_for_each_entry(pol, entry,
1997                                      &xfrm_policy_inexact[dir], bydst)
1998                         prune_one_bundle(pol, func, &gc_list);
1999
2000                 table = xfrm_policy_bydst[dir].table;
2001                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
2002                         hlist_for_each_entry(pol, entry, table + i, bydst)
2003                                 prune_one_bundle(pol, func, &gc_list);
2004                 }
2005         }
2006         read_unlock_bh(&xfrm_policy_lock);
2007
2008         while (gc_list) {
2009                 struct dst_entry *dst = gc_list;
2010                 gc_list = dst->next;
2011                 dst_free(dst);
2012         }
2013 }
2014
2015 static int unused_bundle(struct dst_entry *dst)
2016 {
2017         return !atomic_read(&dst->__refcnt);
2018 }
2019
2020 static void __xfrm_garbage_collect(void)
2021 {
2022         xfrm_prune_bundles(unused_bundle);
2023 }
2024
2025 static int xfrm_flush_bundles(void)
2026 {
2027         xfrm_prune_bundles(stale_bundle);
2028         return 0;
2029 }
2030
2031 static void xfrm_init_pmtu(struct dst_entry *dst)
2032 {
2033         do {
2034                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2035                 u32 pmtu, route_mtu_cached;
2036
2037                 pmtu = dst_mtu(dst->child);
2038                 xdst->child_mtu_cached = pmtu;
2039
2040                 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
2041
2042                 route_mtu_cached = dst_mtu(xdst->route);
2043                 xdst->route_mtu_cached = route_mtu_cached;
2044
2045                 if (pmtu > route_mtu_cached)
2046                         pmtu = route_mtu_cached;
2047
2048                 dst->metrics[RTAX_MTU-1] = pmtu;
2049         } while ((dst = dst->next));
2050 }
2051
2052 /* Check that the bundle accepts the flow and its components are
2053  * still valid.
2054  */
2055
2056 int xfrm_bundle_ok(struct xfrm_policy *pol, struct xfrm_dst *first,
2057                 struct flowi *fl, int family, int strict)
2058 {
2059         struct dst_entry *dst = &first->u.dst;
2060         struct xfrm_dst *last;
2061         u32 mtu;
2062
2063         if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) ||
2064             (dst->dev && !netif_running(dst->dev)))
2065                 return 0;
2066 #ifdef CONFIG_XFRM_SUB_POLICY
2067         if (fl) {
2068                 if (first->origin && !flow_cache_uli_match(first->origin, fl))
2069                         return 0;
2070                 if (first->partner &&
2071                     !xfrm_selector_match(first->partner, fl, family))
2072                         return 0;
2073         }
2074 #endif
2075
2076         last = NULL;
2077
2078         do {
2079                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2080
2081                 if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family))
2082                         return 0;
2083                 if (fl && pol &&
2084                     !security_xfrm_state_pol_flow_match(dst->xfrm, pol, fl))
2085                         return 0;
2086                 if (dst->xfrm->km.state != XFRM_STATE_VALID)
2087                         return 0;
2088                 if (xdst->genid != dst->xfrm->genid)
2089                         return 0;
2090
2091                 if (strict && fl &&
2092                     !(dst->xfrm->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) &&
2093                     !xfrm_state_addr_flow_check(dst->xfrm, fl, family))
2094                         return 0;
2095
2096                 mtu = dst_mtu(dst->child);
2097                 if (xdst->child_mtu_cached != mtu) {
2098                         last = xdst;
2099                         xdst->child_mtu_cached = mtu;
2100                 }
2101
2102                 if (!dst_check(xdst->route, xdst->route_cookie))
2103                         return 0;
2104                 mtu = dst_mtu(xdst->route);
2105                 if (xdst->route_mtu_cached != mtu) {
2106                         last = xdst;
2107                         xdst->route_mtu_cached = mtu;
2108                 }
2109
2110                 dst = dst->child;
2111         } while (dst->xfrm);
2112
2113         if (likely(!last))
2114                 return 1;
2115
2116         mtu = last->child_mtu_cached;
2117         for (;;) {
2118                 dst = &last->u.dst;
2119
2120                 mtu = xfrm_state_mtu(dst->xfrm, mtu);
2121                 if (mtu > last->route_mtu_cached)
2122                         mtu = last->route_mtu_cached;
2123                 dst->metrics[RTAX_MTU-1] = mtu;
2124
2125                 if (last == first)
2126                         break;
2127
2128                 last = (struct xfrm_dst *)last->u.dst.next;
2129                 last->child_mtu_cached = mtu;
2130         }
2131
2132         return 1;
2133 }
2134
2135 EXPORT_SYMBOL(xfrm_bundle_ok);
2136
2137 int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
2138 {
2139         int err = 0;
2140         if (unlikely(afinfo == NULL))
2141                 return -EINVAL;
2142         if (unlikely(afinfo->family >= NPROTO))
2143                 return -EAFNOSUPPORT;
2144         write_lock_bh(&xfrm_policy_afinfo_lock);
2145         if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
2146                 err = -ENOBUFS;
2147         else {
2148                 struct dst_ops *dst_ops = afinfo->dst_ops;
2149                 if (likely(dst_ops->kmem_cachep == NULL))
2150                         dst_ops->kmem_cachep = xfrm_dst_cache;
2151                 if (likely(dst_ops->check == NULL))
2152                         dst_ops->check = xfrm_dst_check;
2153                 if (likely(dst_ops->negative_advice == NULL))
2154                         dst_ops->negative_advice = xfrm_negative_advice;
2155                 if (likely(dst_ops->link_failure == NULL))
2156                         dst_ops->link_failure = xfrm_link_failure;
2157                 if (likely(afinfo->garbage_collect == NULL))
2158                         afinfo->garbage_collect = __xfrm_garbage_collect;
2159                 xfrm_policy_afinfo[afinfo->family] = afinfo;
2160         }
2161         write_unlock_bh(&xfrm_policy_afinfo_lock);
2162         return err;
2163 }
2164 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
2165
2166 int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
2167 {
2168         int err = 0;
2169         if (unlikely(afinfo == NULL))
2170                 return -EINVAL;
2171         if (unlikely(afinfo->family >= NPROTO))
2172                 return -EAFNOSUPPORT;
2173         write_lock_bh(&xfrm_policy_afinfo_lock);
2174         if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
2175                 if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
2176                         err = -EINVAL;
2177                 else {
2178                         struct dst_ops *dst_ops = afinfo->dst_ops;
2179                         xfrm_policy_afinfo[afinfo->family] = NULL;
2180                         dst_ops->kmem_cachep = NULL;
2181                         dst_ops->check = NULL;
2182                         dst_ops->negative_advice = NULL;
2183                         dst_ops->link_failure = NULL;
2184                         afinfo->garbage_collect = NULL;
2185                 }
2186         }
2187         write_unlock_bh(&xfrm_policy_afinfo_lock);
2188         return err;
2189 }
2190 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
2191
2192 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
2193 {
2194         struct xfrm_policy_afinfo *afinfo;
2195         if (unlikely(family >= NPROTO))
2196                 return NULL;
2197         read_lock(&xfrm_policy_afinfo_lock);
2198         afinfo = xfrm_policy_afinfo[family];
2199         if (unlikely(!afinfo))
2200                 read_unlock(&xfrm_policy_afinfo_lock);
2201         return afinfo;
2202 }
2203
2204 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
2205 {
2206         read_unlock(&xfrm_policy_afinfo_lock);
2207 }
2208
2209 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
2210 {
2211         struct net_device *dev = ptr;
2212
2213         if (dev->nd_net != &init_net)
2214                 return NOTIFY_DONE;
2215
2216         switch (event) {
2217         case NETDEV_DOWN:
2218                 xfrm_flush_bundles();
2219         }
2220         return NOTIFY_DONE;
2221 }
2222
2223 static struct notifier_block xfrm_dev_notifier = {
2224         xfrm_dev_event,
2225         NULL,
2226         0
2227 };
2228
2229 static void __init xfrm_policy_init(void)
2230 {
2231         unsigned int hmask, sz;
2232         int dir;
2233
2234         xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
2235                                            sizeof(struct xfrm_dst),
2236                                            0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
2237                                            NULL);
2238
2239         hmask = 8 - 1;
2240         sz = (hmask+1) * sizeof(struct hlist_head);
2241
2242         xfrm_policy_byidx = xfrm_hash_alloc(sz);
2243         xfrm_idx_hmask = hmask;
2244         if (!xfrm_policy_byidx)
2245                 panic("XFRM: failed to allocate byidx hash\n");
2246
2247         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
2248                 struct xfrm_policy_hash *htab;
2249
2250                 INIT_HLIST_HEAD(&xfrm_policy_inexact[dir]);
2251
2252                 htab = &xfrm_policy_bydst[dir];
2253                 htab->table = xfrm_hash_alloc(sz);
2254                 htab->hmask = hmask;
2255                 if (!htab->table)
2256                         panic("XFRM: failed to allocate bydst hash\n");
2257         }
2258
2259         INIT_WORK(&xfrm_policy_gc_work, xfrm_policy_gc_task);
2260         register_netdevice_notifier(&xfrm_dev_notifier);
2261 }
2262
2263 void __init xfrm_init(void)
2264 {
2265         xfrm_state_init();
2266         xfrm_policy_init();
2267         xfrm_input_init();
2268 }
2269
2270 #ifdef CONFIG_AUDITSYSCALL
2271 static inline void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
2272                                                 struct audit_buffer *audit_buf)
2273 {
2274         struct xfrm_sec_ctx *ctx = xp->security;
2275         struct xfrm_selector *sel = &xp->selector;
2276
2277         if (ctx)
2278                 audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s",
2279                                  ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str);
2280
2281         switch(sel->family) {
2282         case AF_INET:
2283                 audit_log_format(audit_buf, " src=" NIPQUAD_FMT,
2284                                  NIPQUAD(sel->saddr.a4));
2285                 if (sel->prefixlen_s != 32)
2286                         audit_log_format(audit_buf, " src_prefixlen=%d",
2287                                          sel->prefixlen_s);
2288                 audit_log_format(audit_buf, " dst=" NIPQUAD_FMT,
2289                                  NIPQUAD(sel->daddr.a4));
2290                 if (sel->prefixlen_d != 32)
2291                         audit_log_format(audit_buf, " dst_prefixlen=%d",
2292                                          sel->prefixlen_d);
2293                 break;
2294         case AF_INET6:
2295                 audit_log_format(audit_buf, " src=" NIP6_FMT,
2296                                  NIP6(*(struct in6_addr *)sel->saddr.a6));
2297                 if (sel->prefixlen_s != 128)
2298                         audit_log_format(audit_buf, " src_prefixlen=%d",
2299                                          sel->prefixlen_s);
2300                 audit_log_format(audit_buf, " dst=" NIP6_FMT,
2301                                  NIP6(*(struct in6_addr *)sel->daddr.a6));
2302                 if (sel->prefixlen_d != 128)
2303                         audit_log_format(audit_buf, " dst_prefixlen=%d",
2304                                          sel->prefixlen_d);
2305                 break;
2306         }
2307 }
2308
2309 void
2310 xfrm_audit_policy_add(struct xfrm_policy *xp, int result, u32 auid, u32 sid)
2311 {
2312         struct audit_buffer *audit_buf;
2313         extern int audit_enabled;
2314
2315         if (audit_enabled == 0)
2316                 return;
2317         audit_buf = xfrm_audit_start(auid, sid);
2318         if (audit_buf == NULL)
2319                 return;
2320         audit_log_format(audit_buf, " op=SPD-add res=%u", result);
2321         xfrm_audit_common_policyinfo(xp, audit_buf);
2322         audit_log_end(audit_buf);
2323 }
2324 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
2325
2326 void
2327 xfrm_audit_policy_delete(struct xfrm_policy *xp, int result, u32 auid, u32 sid)
2328 {
2329         struct audit_buffer *audit_buf;
2330         extern int audit_enabled;
2331
2332         if (audit_enabled == 0)
2333                 return;
2334         audit_buf = xfrm_audit_start(auid, sid);
2335         if (audit_buf == NULL)
2336                 return;
2337         audit_log_format(audit_buf, " op=SPD-delete res=%u", result);
2338         xfrm_audit_common_policyinfo(xp, audit_buf);
2339         audit_log_end(audit_buf);
2340 }
2341 EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
2342 #endif
2343
2344 #ifdef CONFIG_XFRM_MIGRATE
2345 static int xfrm_migrate_selector_match(struct xfrm_selector *sel_cmp,
2346                                        struct xfrm_selector *sel_tgt)
2347 {
2348         if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
2349                 if (sel_tgt->family == sel_cmp->family &&
2350                     xfrm_addr_cmp(&sel_tgt->daddr, &sel_cmp->daddr,
2351                                   sel_cmp->family) == 0 &&
2352                     xfrm_addr_cmp(&sel_tgt->saddr, &sel_cmp->saddr,
2353                                   sel_cmp->family) == 0 &&
2354                     sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
2355                     sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
2356                         return 1;
2357                 }
2358         } else {
2359                 if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
2360                         return 1;
2361                 }
2362         }
2363         return 0;
2364 }
2365
2366 static struct xfrm_policy * xfrm_migrate_policy_find(struct xfrm_selector *sel,
2367                                                      u8 dir, u8 type)
2368 {
2369         struct xfrm_policy *pol, *ret = NULL;
2370         struct hlist_node *entry;
2371         struct hlist_head *chain;
2372         u32 priority = ~0U;
2373
2374         read_lock_bh(&xfrm_policy_lock);
2375         chain = policy_hash_direct(&sel->daddr, &sel->saddr, sel->family, dir);
2376         hlist_for_each_entry(pol, entry, chain, bydst) {
2377                 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
2378                     pol->type == type) {
2379                         ret = pol;
2380                         priority = ret->priority;
2381                         break;
2382                 }
2383         }
2384         chain = &xfrm_policy_inexact[dir];
2385         hlist_for_each_entry(pol, entry, chain, bydst) {
2386                 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
2387                     pol->type == type &&
2388                     pol->priority < priority) {
2389                         ret = pol;
2390                         break;
2391                 }
2392         }
2393
2394         if (ret)
2395                 xfrm_pol_hold(ret);
2396
2397         read_unlock_bh(&xfrm_policy_lock);
2398
2399         return ret;
2400 }
2401
2402 static int migrate_tmpl_match(struct xfrm_migrate *m, struct xfrm_tmpl *t)
2403 {
2404         int match = 0;
2405
2406         if (t->mode == m->mode && t->id.proto == m->proto &&
2407             (m->reqid == 0 || t->reqid == m->reqid)) {
2408                 switch (t->mode) {
2409                 case XFRM_MODE_TUNNEL:
2410                 case XFRM_MODE_BEET:
2411                         if (xfrm_addr_cmp(&t->id.daddr, &m->old_daddr,
2412                                           m->old_family) == 0 &&
2413                             xfrm_addr_cmp(&t->saddr, &m->old_saddr,
2414                                           m->old_family) == 0) {
2415                                 match = 1;
2416                         }
2417                         break;
2418                 case XFRM_MODE_TRANSPORT:
2419                         /* in case of transport mode, template does not store
2420                            any IP addresses, hence we just compare mode and
2421                            protocol */
2422                         match = 1;
2423                         break;
2424                 default:
2425                         break;
2426                 }
2427         }
2428         return match;
2429 }
2430
2431 /* update endpoint address(es) of template(s) */
2432 static int xfrm_policy_migrate(struct xfrm_policy *pol,
2433                                struct xfrm_migrate *m, int num_migrate)
2434 {
2435         struct xfrm_migrate *mp;
2436         struct dst_entry *dst;
2437         int i, j, n = 0;
2438
2439         write_lock_bh(&pol->lock);
2440         if (unlikely(pol->dead)) {
2441                 /* target policy has been deleted */
2442                 write_unlock_bh(&pol->lock);
2443                 return -ENOENT;
2444         }
2445
2446         for (i = 0; i < pol->xfrm_nr; i++) {
2447                 for (j = 0, mp = m; j < num_migrate; j++, mp++) {
2448                         if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
2449                                 continue;
2450                         n++;
2451                         if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
2452                             pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
2453                                 continue;
2454                         /* update endpoints */
2455                         memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
2456                                sizeof(pol->xfrm_vec[i].id.daddr));
2457                         memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
2458                                sizeof(pol->xfrm_vec[i].saddr));
2459                         pol->xfrm_vec[i].encap_family = mp->new_family;
2460                         /* flush bundles */
2461                         while ((dst = pol->bundles) != NULL) {
2462                                 pol->bundles = dst->next;
2463                                 dst_free(dst);
2464                         }
2465                 }
2466         }
2467
2468         write_unlock_bh(&pol->lock);
2469
2470         if (!n)
2471                 return -ENODATA;
2472
2473         return 0;
2474 }
2475
2476 static int xfrm_migrate_check(struct xfrm_migrate *m, int num_migrate)
2477 {
2478         int i, j;
2479
2480         if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
2481                 return -EINVAL;
2482
2483         for (i = 0; i < num_migrate; i++) {
2484                 if ((xfrm_addr_cmp(&m[i].old_daddr, &m[i].new_daddr,
2485                                    m[i].old_family) == 0) &&
2486                     (xfrm_addr_cmp(&m[i].old_saddr, &m[i].new_saddr,
2487                                    m[i].old_family) == 0))
2488                         return -EINVAL;
2489                 if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
2490                     xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
2491                         return -EINVAL;
2492
2493                 /* check if there is any duplicated entry */
2494                 for (j = i + 1; j < num_migrate; j++) {
2495                         if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
2496                                     sizeof(m[i].old_daddr)) &&
2497                             !memcmp(&m[i].old_saddr, &m[j].old_saddr,
2498                                     sizeof(m[i].old_saddr)) &&
2499                             m[i].proto == m[j].proto &&
2500                             m[i].mode == m[j].mode &&
2501                             m[i].reqid == m[j].reqid &&
2502                             m[i].old_family == m[j].old_family)
2503                                 return -EINVAL;
2504                 }
2505         }
2506
2507         return 0;
2508 }
2509
2510 int xfrm_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
2511                  struct xfrm_migrate *m, int num_migrate)
2512 {
2513         int i, err, nx_cur = 0, nx_new = 0;
2514         struct xfrm_policy *pol = NULL;
2515         struct xfrm_state *x, *xc;
2516         struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
2517         struct xfrm_state *x_new[XFRM_MAX_DEPTH];
2518         struct xfrm_migrate *mp;
2519
2520         if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
2521                 goto out;
2522
2523         /* Stage 1 - find policy */
2524         if ((pol = xfrm_migrate_policy_find(sel, dir, type)) == NULL) {
2525                 err = -ENOENT;
2526                 goto out;
2527         }
2528
2529         /* Stage 2 - find and update state(s) */
2530         for (i = 0, mp = m; i < num_migrate; i++, mp++) {
2531                 if ((x = xfrm_migrate_state_find(mp))) {
2532                         x_cur[nx_cur] = x;
2533                         nx_cur++;
2534                         if ((xc = xfrm_state_migrate(x, mp))) {
2535                                 x_new[nx_new] = xc;
2536                                 nx_new++;
2537                         } else {
2538                                 err = -ENODATA;
2539                                 goto restore_state;
2540                         }
2541                 }
2542         }
2543
2544         /* Stage 3 - update policy */
2545         if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
2546                 goto restore_state;
2547
2548         /* Stage 4 - delete old state(s) */
2549         if (nx_cur) {
2550                 xfrm_states_put(x_cur, nx_cur);
2551                 xfrm_states_delete(x_cur, nx_cur);
2552         }
2553
2554         /* Stage 5 - announce */
2555         km_migrate(sel, dir, type, m, num_migrate);
2556
2557         xfrm_pol_put(pol);
2558
2559         return 0;
2560 out:
2561         return err;
2562
2563 restore_state:
2564         if (pol)
2565                 xfrm_pol_put(pol);
2566         if (nx_cur)
2567                 xfrm_states_put(x_cur, nx_cur);
2568         if (nx_new)
2569                 xfrm_states_delete(x_new, nx_new);
2570
2571         return err;
2572 }
2573 EXPORT_SYMBOL(xfrm_migrate);
2574 #endif