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/slab.h>
  17 #include <linux/kmod.h>
  18 #include <linux/list.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/workqueue.h>
  21 #include <linux/notifier.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/netfilter.h>
  24 #include <linux/module.h>
  25 #include <linux/cache.h>
  26 #include <net/xfrm.h>
  27 #include <net/ip.h>
  28 #include <linux/audit.h>
  29 #include <linux/cache.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 struct xfrm_policy_afinfo *xfrm_policy_lock_afinfo(unsigned int family);
  55 static void xfrm_policy_unlock_afinfo(struct xfrm_policy_afinfo *afinfo);
  56
  57 static inline int
  58 __xfrm4_selector_match(struct xfrm_selector *sel, struct flowi *fl)
  59 {
  60         return  addr_match(&fl->fl4_dst, &sel->daddr, sel->prefixlen_d) &&
  61                 addr_match(&fl->fl4_src, &sel->saddr, sel->prefixlen_s) &&
  62                 !((xfrm_flowi_dport(fl) ^ sel->dport) & sel->dport_mask) &&
  63                 !((xfrm_flowi_sport(fl) ^ sel->sport) & sel->sport_mask) &&
  64                 (fl->proto == sel->proto || !sel->proto) &&
  65                 (fl->oif == sel->ifindex || !sel->ifindex);
  66 }
  67
  68 static inline int
  69 __xfrm6_selector_match(struct xfrm_selector *sel, struct flowi *fl)
  70 {
  71         return  addr_match(&fl->fl6_dst, &sel->daddr, sel->prefixlen_d) &&
  72                 addr_match(&fl->fl6_src, &sel->saddr, sel->prefixlen_s) &&
  73                 !((xfrm_flowi_dport(fl) ^ sel->dport) & sel->dport_mask) &&
  74                 !((xfrm_flowi_sport(fl) ^ sel->sport) & sel->sport_mask) &&
  75                 (fl->proto == sel->proto || !sel->proto) &&
  76                 (fl->oif == sel->ifindex || !sel->ifindex);
  77 }
  78
  79 int xfrm_selector_match(struct xfrm_selector *sel, struct flowi *fl,
  80                     unsigned short family)
  81 {
  82         switch (family) {
  83         case AF_INET:
  84                 return __xfrm4_selector_match(sel, fl);
  85         case AF_INET6:
  86                 return __xfrm6_selector_match(sel, fl);
  87         }
  88         return 0;
  89 }
  90
  91 int xfrm_register_type(struct xfrm_type *type, unsigned short family)
  92 {
  93         struct xfrm_policy_afinfo *afinfo = xfrm_policy_lock_afinfo(family);
  94         struct xfrm_type **typemap;
  95         int err = 0;
  96
  97         if (unlikely(afinfo == NULL))
  98                 return -EAFNOSUPPORT;
  99         typemap = afinfo->type_map;
 100
 101         if (likely(typemap[type->proto] == NULL))
 102                 typemap[type->proto] = type;
 103         else
 104                 err = -EEXIST;
 105         xfrm_policy_unlock_afinfo(afinfo);
 106         return err;
 107 }
 108 EXPORT_SYMBOL(xfrm_register_type);
 109
 110 int xfrm_unregister_type(struct xfrm_type *type, unsigned short family)
 111 {
 112         struct xfrm_policy_afinfo *afinfo = xfrm_policy_lock_afinfo(family);
 113         struct xfrm_type **typemap;
 114         int err = 0;
 115
 116         if (unlikely(afinfo == NULL))
 117                 return -EAFNOSUPPORT;
 118         typemap = afinfo->type_map;
 119
 120         if (unlikely(typemap[type->proto] != type))
 121                 err = -ENOENT;
 122         else
 123                 typemap[type->proto] = NULL;
 124         xfrm_policy_unlock_afinfo(afinfo);
 125         return err;
 126 }
 127 EXPORT_SYMBOL(xfrm_unregister_type);
 128
 129 struct xfrm_type *xfrm_get_type(u8 proto, unsigned short family)
 130 {
 131         struct xfrm_policy_afinfo *afinfo;
 132         struct xfrm_type **typemap;
 133         struct xfrm_type *type;
 134         int modload_attempted = 0;
 135
 136 retry:
 137         afinfo = xfrm_policy_get_afinfo(family);
 138         if (unlikely(afinfo == NULL))
 139                 return NULL;
 140         typemap = afinfo->type_map;
 141
 142         type = typemap[proto];
 143         if (unlikely(type && !try_module_get(type->owner)))
 144                 type = NULL;
 145         if (!type && !modload_attempted) {
 146                 xfrm_policy_put_afinfo(afinfo);
 147                 request_module("xfrm-type-%d-%d",
 148                                (int) family, (int) proto);
 149                 modload_attempted = 1;
 150                 goto retry;
 151         }
 152
 153         xfrm_policy_put_afinfo(afinfo);
 154         return type;
 155 }
 156
 157 int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl,
 158                     unsigned short family)
 159 {
 160         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
 161         int err = 0;
 162
 163         if (unlikely(afinfo == NULL))
 164                 return -EAFNOSUPPORT;
 165
 166         if (likely(afinfo->dst_lookup != NULL))
 167                 err = afinfo->dst_lookup(dst, fl);
 168         else
 169                 err = -EINVAL;
 170         xfrm_policy_put_afinfo(afinfo);
 171         return err;
 172 }
 173 EXPORT_SYMBOL(xfrm_dst_lookup);
 174
 175 void xfrm_put_type(struct xfrm_type *type)
 176 {
 177         module_put(type->owner);
 178 }
 179
 180 int xfrm_register_mode(struct xfrm_mode *mode, int family)
 181 {
 182         struct xfrm_policy_afinfo *afinfo;
 183         struct xfrm_mode **modemap;
 184         int err;
 185
 186         if (unlikely(mode->encap >= XFRM_MODE_MAX))
 187                 return -EINVAL;
 188
 189         afinfo = xfrm_policy_lock_afinfo(family);
 190         if (unlikely(afinfo == NULL))
 191                 return -EAFNOSUPPORT;
 192
 193         err = -EEXIST;
 194         modemap = afinfo->mode_map;
 195         if (likely(modemap[mode->encap] == NULL)) {
 196                 modemap[mode->encap] = mode;
 197                 err = 0;
 198         }
 199
 200         xfrm_policy_unlock_afinfo(afinfo);
 201         return err;
 202 }
 203 EXPORT_SYMBOL(xfrm_register_mode);
 204
 205 int xfrm_unregister_mode(struct xfrm_mode *mode, int family)
 206 {
 207         struct xfrm_policy_afinfo *afinfo;
 208         struct xfrm_mode **modemap;
 209         int err;
 210
 211         if (unlikely(mode->encap >= XFRM_MODE_MAX))
 212                 return -EINVAL;
 213
 214         afinfo = xfrm_policy_lock_afinfo(family);
 215         if (unlikely(afinfo == NULL))
 216                 return -EAFNOSUPPORT;
 217
 218         err = -ENOENT;
 219         modemap = afinfo->mode_map;
 220         if (likely(modemap[mode->encap] == mode)) {
 221                 modemap[mode->encap] = NULL;
 222                 err = 0;
 223         }
 224
 225         xfrm_policy_unlock_afinfo(afinfo);
 226         return err;
 227 }
 228 EXPORT_SYMBOL(xfrm_unregister_mode);
 229
 230 struct xfrm_mode *xfrm_get_mode(unsigned int encap, int family)
 231 {
 232         struct xfrm_policy_afinfo *afinfo;
 233         struct xfrm_mode *mode;
 234         int modload_attempted = 0;
 235
 236         if (unlikely(encap >= XFRM_MODE_MAX))
 237                 return NULL;
 238
 239 retry:
 240         afinfo = xfrm_policy_get_afinfo(family);
 241         if (unlikely(afinfo == NULL))
 242                 return NULL;
 243
 244         mode = afinfo->mode_map[encap];
 245         if (unlikely(mode && !try_module_get(mode->owner)))
 246                 mode = NULL;
 247         if (!mode && !modload_attempted) {
 248                 xfrm_policy_put_afinfo(afinfo);
 249                 request_module("xfrm-mode-%d-%d", family, encap);
 250                 modload_attempted = 1;
 251                 goto retry;
 252         }
 253
 254         xfrm_policy_put_afinfo(afinfo);
 255         return mode;
 256 }
 257
 258 void xfrm_put_mode(struct xfrm_mode *mode)
 259 {
 260         module_put(mode->owner);
 261 }
 262
 263 static inline unsigned long make_jiffies(long secs)
 264 {
 265         if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
 266                 return MAX_SCHEDULE_TIMEOUT-1;
 267         else
 268                 return secs*HZ;
 269 }
 270
 271 static void xfrm_policy_timer(unsigned long data)
 272 {
 273         struct xfrm_policy *xp = (struct xfrm_policy*)data;
 274         unsigned long now = get_seconds();
 275         long next = LONG_MAX;
 276         int warn = 0;
 277         int dir;
 278
 279         read_lock(&xp->lock);
 280
 281         if (xp->dead)
 282                 goto out;
 283
 284         dir = xfrm_policy_id2dir(xp->index);
 285
 286         if (xp->lft.hard_add_expires_seconds) {
 287                 long tmo = xp->lft.hard_add_expires_seconds +
 288                         xp->curlft.add_time - now;
 289                 if (tmo <= 0)
 290                         goto expired;
 291                 if (tmo < next)
 292                         next = tmo;
 293         }
 294         if (xp->lft.hard_use_expires_seconds) {
 295                 long tmo = xp->lft.hard_use_expires_seconds +
 296                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 297                 if (tmo <= 0)
 298                         goto expired;
 299                 if (tmo < next)
 300                         next = tmo;
 301         }
 302         if (xp->lft.soft_add_expires_seconds) {
 303                 long tmo = xp->lft.soft_add_expires_seconds +
 304                         xp->curlft.add_time - now;
 305                 if (tmo <= 0) {
 306                         warn = 1;
 307                         tmo = XFRM_KM_TIMEOUT;
 308                 }
 309                 if (tmo < next)
 310                         next = tmo;
 311         }
 312         if (xp->lft.soft_use_expires_seconds) {
 313                 long tmo = xp->lft.soft_use_expires_seconds +
 314                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 315                 if (tmo <= 0) {
 316                         warn = 1;
 317                         tmo = XFRM_KM_TIMEOUT;
 318                 }
 319                 if (tmo < next)
 320                         next = tmo;
 321         }
 322
 323         if (warn)
 324                 km_policy_expired(xp, dir, 0, 0);
 325         if (next != LONG_MAX &&
 326             !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
 327                 xfrm_pol_hold(xp);
 328
 329 out:
 330         read_unlock(&xp->lock);
 331         xfrm_pol_put(xp);
 332         return;
 333
 334 expired:
 335         read_unlock(&xp->lock);
 336         if (!xfrm_policy_delete(xp, dir))
 337                 km_policy_expired(xp, dir, 1, 0);
 338         xfrm_pol_put(xp);
 339 }
 340
 341
 342 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
 343  * SPD calls.
 344  */
 345
 346 struct xfrm_policy *xfrm_policy_alloc(gfp_t gfp)
 347 {
 348         struct xfrm_policy *policy;
 349
 350         policy = kzalloc(sizeof(struct xfrm_policy), gfp);
 351
 352         if (policy) {
 353                 INIT_HLIST_NODE(&policy->bydst);
 354                 INIT_HLIST_NODE(&policy->byidx);
 355                 rwlock_init(&policy->lock);
 356                 atomic_set(&policy->refcnt, 1);
 357                 init_timer(&policy->timer);
 358                 policy->timer.data = (unsigned long)policy;
 359                 policy->timer.function = xfrm_policy_timer;
 360         }
 361         return policy;
 362 }
 363 EXPORT_SYMBOL(xfrm_policy_alloc);
 364
 365 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
 366
 367 void __xfrm_policy_destroy(struct xfrm_policy *policy)
 368 {
 369         BUG_ON(!policy->dead);
 370
 371         BUG_ON(policy->bundles);
 372
 373         if (del_timer(&policy->timer))
 374                 BUG();
 375
 376         security_xfrm_policy_free(policy);
 377         kfree(policy);
 378 }
 379 EXPORT_SYMBOL(__xfrm_policy_destroy);
 380
 381 static void xfrm_policy_gc_kill(struct xfrm_policy *policy)
 382 {
 383         struct dst_entry *dst;
 384
 385         while ((dst = policy->bundles) != NULL) {
 386                 policy->bundles = dst->next;
 387                 dst_free(dst);
 388         }
 389
 390         if (del_timer(&policy->timer))
 391                 atomic_dec(&policy->refcnt);
 392
 393         if (atomic_read(&policy->refcnt) > 1)
 394                 flow_cache_flush();
 395
 396         xfrm_pol_put(policy);
 397 }
 398
 399 static void xfrm_policy_gc_task(struct work_struct *work)
 400 {
 401         struct xfrm_policy *policy;
 402         struct hlist_node *entry, *tmp;
 403         struct hlist_head gc_list;
 404
 405         spin_lock_bh(&xfrm_policy_gc_lock);
 406         gc_list.first = xfrm_policy_gc_list.first;
 407         INIT_HLIST_HEAD(&xfrm_policy_gc_list);
 408         spin_unlock_bh(&xfrm_policy_gc_lock);
 409
 410         hlist_for_each_entry_safe(policy, entry, tmp, &gc_list, bydst)
 411                 xfrm_policy_gc_kill(policy);
 412 }
 413
 414 /* Rule must be locked. Release descentant resources, announce
 415  * entry dead. The rule must be unlinked from lists to the moment.
 416  */
 417
 418 static void xfrm_policy_kill(struct xfrm_policy *policy)
 419 {
 420         int dead;
 421
 422         write_lock_bh(&policy->lock);
 423         dead = policy->dead;
 424         policy->dead = 1;
 425         write_unlock_bh(&policy->lock);
 426
 427         if (unlikely(dead)) {
 428                 WARN_ON(1);
 429                 return;
 430         }
 431
 432         spin_lock(&xfrm_policy_gc_lock);
 433         hlist_add_head(&policy->bydst, &xfrm_policy_gc_list);
 434         spin_unlock(&xfrm_policy_gc_lock);
 435
 436         schedule_work(&xfrm_policy_gc_work);
 437 }
 438
 439 struct xfrm_policy_hash {
 440         struct hlist_head       *table;
 441         unsigned int            hmask;
 442 };
 443
 444 static struct hlist_head xfrm_policy_inexact[XFRM_POLICY_MAX*2];
 445 static struct xfrm_policy_hash xfrm_policy_bydst[XFRM_POLICY_MAX*2] __read_mostly;
 446 static struct hlist_head *xfrm_policy_byidx __read_mostly;
 447 static unsigned int xfrm_idx_hmask __read_mostly;
 448 static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
 449
 450 static inline unsigned int idx_hash(u32 index)
 451 {
 452         return __idx_hash(index, xfrm_idx_hmask);
 453 }
 454
 455 static struct hlist_head *policy_hash_bysel(struct xfrm_selector *sel, unsigned short family, int dir)
 456 {
 457         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
 458         unsigned int hash = __sel_hash(sel, family, hmask);
 459
 460         return (hash == hmask + 1 ?
 461                 &xfrm_policy_inexact[dir] :
 462                 xfrm_policy_bydst[dir].table + hash);
 463 }
 464
 465 static struct hlist_head *policy_hash_direct(xfrm_address_t *daddr, xfrm_address_t *saddr, unsigned short family, int dir)
 466 {
 467         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
 468         unsigned int hash = __addr_hash(daddr, saddr, family, hmask);
 469
 470         return xfrm_policy_bydst[dir].table + hash;
 471 }
 472
 473 static void xfrm_dst_hash_transfer(struct hlist_head *list,
 474                                    struct hlist_head *ndsttable,
 475                                    unsigned int nhashmask)
 476 {
 477         struct hlist_node *entry, *tmp;
 478         struct xfrm_policy *pol;
 479
 480         hlist_for_each_entry_safe(pol, entry, tmp, list, bydst) {
 481                 unsigned int h;
 482
 483                 h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
 484                                 pol->family, nhashmask);
 485                 hlist_add_head(&pol->bydst, ndsttable+h);
 486         }
 487 }
 488
 489 static void xfrm_idx_hash_transfer(struct hlist_head *list,
 490                                    struct hlist_head *nidxtable,
 491                                    unsigned int nhashmask)
 492 {
 493         struct hlist_node *entry, *tmp;
 494         struct xfrm_policy *pol;
 495
 496         hlist_for_each_entry_safe(pol, entry, tmp, list, byidx) {
 497                 unsigned int h;
 498
 499                 h = __idx_hash(pol->index, nhashmask);
 500                 hlist_add_head(&pol->byidx, nidxtable+h);
 501         }
 502 }
 503
 504 static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
 505 {
 506         return ((old_hmask + 1) << 1) - 1;
 507 }
 508
 509 static void xfrm_bydst_resize(int dir)
 510 {
 511         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
 512         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 513         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 514         struct hlist_head *odst = xfrm_policy_bydst[dir].table;
 515         struct hlist_head *ndst = xfrm_hash_alloc(nsize);
 516         int i;
 517
 518         if (!ndst)
 519                 return;
 520
 521         write_lock_bh(&xfrm_policy_lock);
 522
 523         for (i = hmask; i >= 0; i--)
 524                 xfrm_dst_hash_transfer(odst + i, ndst, nhashmask);
 525
 526         xfrm_policy_bydst[dir].table = ndst;
 527         xfrm_policy_bydst[dir].hmask = nhashmask;
 528
 529         write_unlock_bh(&xfrm_policy_lock);
 530
 531         xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
 532 }
 533
 534 static void xfrm_byidx_resize(int total)
 535 {
 536         unsigned int hmask = xfrm_idx_hmask;
 537         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 538         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 539         struct hlist_head *oidx = xfrm_policy_byidx;
 540         struct hlist_head *nidx = xfrm_hash_alloc(nsize);
 541         int i;
 542
 543         if (!nidx)
 544                 return;
 545
 546         write_lock_bh(&xfrm_policy_lock);
 547
 548         for (i = hmask; i >= 0; i--)
 549                 xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
 550
 551         xfrm_policy_byidx = nidx;
 552         xfrm_idx_hmask = nhashmask;
 553
 554         write_unlock_bh(&xfrm_policy_lock);
 555
 556         xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
 557 }
 558
 559 static inline int xfrm_bydst_should_resize(int dir, int *total)
 560 {
 561         unsigned int cnt = xfrm_policy_count[dir];
 562         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
 563
 564         if (total)
 565                 *total += cnt;
 566
 567         if ((hmask + 1) < xfrm_policy_hashmax &&
 568             cnt > hmask)
 569                 return 1;
 570
 571         return 0;
 572 }
 573
 574 static inline int xfrm_byidx_should_resize(int total)
 575 {
 576         unsigned int hmask = xfrm_idx_hmask;
 577
 578         if ((hmask + 1) < xfrm_policy_hashmax &&
 579             total > hmask)
 580                 return 1;
 581
 582         return 0;
 583 }
 584
 585 void xfrm_spd_getinfo(struct xfrmk_spdinfo *si)
 586 {
 587         read_lock_bh(&xfrm_policy_lock);
 588         si->incnt = xfrm_policy_count[XFRM_POLICY_IN];
 589         si->outcnt = xfrm_policy_count[XFRM_POLICY_OUT];
 590         si->fwdcnt = xfrm_policy_count[XFRM_POLICY_FWD];
 591         si->inscnt = xfrm_policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX];
 592         si->outscnt = xfrm_policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX];
 593         si->fwdscnt = xfrm_policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
 594         si->spdhcnt = xfrm_idx_hmask;
 595         si->spdhmcnt = xfrm_policy_hashmax;
 596         read_unlock_bh(&xfrm_policy_lock);
 597 }
 598 EXPORT_SYMBOL(xfrm_spd_getinfo);
 599
 600 static DEFINE_MUTEX(hash_resize_mutex);
 601 static void xfrm_hash_resize(struct work_struct *__unused)
 602 {
 603         int dir, total;
 604
 605         mutex_lock(&hash_resize_mutex);
 606
 607         total = 0;
 608         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
 609                 if (xfrm_bydst_should_resize(dir, &total))
 610                         xfrm_bydst_resize(dir);
 611         }
 612         if (xfrm_byidx_should_resize(total))
 613                 xfrm_byidx_resize(total);
 614
 615         mutex_unlock(&hash_resize_mutex);
 616 }
 617
 618 static DECLARE_WORK(xfrm_hash_work, xfrm_hash_resize);
 619
 620 /* Generate new index... KAME seems to generate them ordered by cost
 621  * of an absolute inpredictability of ordering of rules. This will not pass. */
 622 static u32 xfrm_gen_index(u8 type, int dir)
 623 {
 624         static u32 idx_generator;
 625
 626         for (;;) {
 627                 struct hlist_node *entry;
 628                 struct hlist_head *list;
 629                 struct xfrm_policy *p;
 630                 u32 idx;
 631                 int found;
 632
 633                 idx = (idx_generator | dir);
 634                 idx_generator += 8;
 635                 if (idx == 0)
 636                         idx = 8;
 637                 list = xfrm_policy_byidx + idx_hash(idx);
 638                 found = 0;
 639                 hlist_for_each_entry(p, entry, list, byidx) {
 640                         if (p->index == idx) {
 641                                 found = 1;
 642                                 break;
 643                         }
 644                 }
 645                 if (!found)
 646                         return idx;
 647         }
 648 }
 649
 650 static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
 651 {
 652         u32 *p1 = (u32 *) s1;
 653         u32 *p2 = (u32 *) s2;
 654         int len = sizeof(struct xfrm_selector) / sizeof(u32);
 655         int i;
 656
 657         for (i = 0; i < len; i++) {
 658                 if (p1[i] != p2[i])
 659                         return 1;
 660         }
 661
 662         return 0;
 663 }
 664
 665 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 666 {
 667         struct xfrm_policy *pol;
 668         struct xfrm_policy *delpol;
 669         struct hlist_head *chain;
 670         struct hlist_node *entry, *newpos;
 671         struct dst_entry *gc_list;
 672
 673         write_lock_bh(&xfrm_policy_lock);
 674         chain = policy_hash_bysel(&policy->selector, policy->family, dir);
 675         delpol = NULL;
 676         newpos = NULL;
 677         hlist_for_each_entry(pol, entry, chain, bydst) {
 678                 if (pol->type == policy->type &&
 679                     !selector_cmp(&pol->selector, &policy->selector) &&
 680                     xfrm_sec_ctx_match(pol->security, policy->security) &&
 681                     !WARN_ON(delpol)) {
 682                         if (excl) {
 683                                 write_unlock_bh(&xfrm_policy_lock);
 684                                 return -EEXIST;
 685                         }
 686                         delpol = pol;
 687                         if (policy->priority > pol->priority)
 688                                 continue;
 689                 } else if (policy->priority >= pol->priority) {
 690                         newpos = &pol->bydst;
 691                         continue;
 692                 }
 693                 if (delpol)
 694                         break;
 695         }
 696         if (newpos)
 697                 hlist_add_after(newpos, &policy->bydst);
 698         else
 699                 hlist_add_head(&policy->bydst, chain);
 700         xfrm_pol_hold(policy);
 701         xfrm_policy_count[dir]++;
 702         atomic_inc(&flow_cache_genid);
 703         if (delpol) {
 704                 hlist_del(&delpol->bydst);
 705                 hlist_del(&delpol->byidx);
 706                 xfrm_policy_count[dir]--;
 707         }
 708         policy->index = delpol ? delpol->index : xfrm_gen_index(policy->type, dir);
 709         hlist_add_head(&policy->byidx, xfrm_policy_byidx+idx_hash(policy->index));
 710         policy->curlft.add_time = get_seconds();
 711         policy->curlft.use_time = 0;
 712         if (!mod_timer(&policy->timer, jiffies + HZ))
 713                 xfrm_pol_hold(policy);
 714         write_unlock_bh(&xfrm_policy_lock);
 715
 716         if (delpol)
 717                 xfrm_policy_kill(delpol);
 718         else if (xfrm_bydst_should_resize(dir, NULL))
 719                 schedule_work(&xfrm_hash_work);
 720
 721         read_lock_bh(&xfrm_policy_lock);
 722         gc_list = NULL;
 723         entry = &policy->bydst;
 724         hlist_for_each_entry_continue(policy, entry, bydst) {
 725                 struct dst_entry *dst;
 726
 727                 write_lock(&policy->lock);
 728                 dst = policy->bundles;
 729                 if (dst) {
 730                         struct dst_entry *tail = dst;
 731                         while (tail->next)
 732                                 tail = tail->next;
 733                         tail->next = gc_list;
 734                         gc_list = dst;
 735
 736                         policy->bundles = NULL;
 737                 }
 738                 write_unlock(&policy->lock);
 739         }
 740         read_unlock_bh(&xfrm_policy_lock);
 741
 742         while (gc_list) {
 743                 struct dst_entry *dst = gc_list;
 744
 745                 gc_list = dst->next;
 746                 dst_free(dst);
 747         }
 748
 749         return 0;
 750 }
 751 EXPORT_SYMBOL(xfrm_policy_insert);
 752
 753 struct xfrm_policy *xfrm_policy_bysel_ctx(u8 type, int dir,
 754                                           struct xfrm_selector *sel,
 755                                           struct xfrm_sec_ctx *ctx, int delete,
 756                                           int *err)
 757 {
 758         struct xfrm_policy *pol, *ret;
 759         struct hlist_head *chain;
 760         struct hlist_node *entry;
 761
 762         *err = 0;
 763         write_lock_bh(&xfrm_policy_lock);
 764         chain = policy_hash_bysel(sel, sel->family, dir);
 765         ret = NULL;
 766         hlist_for_each_entry(pol, entry, chain, bydst) {
 767                 if (pol->type == type &&
 768                     !selector_cmp(sel, &pol->selector) &&
 769                     xfrm_sec_ctx_match(ctx, pol->security)) {
 770                         xfrm_pol_hold(pol);
 771                         if (delete) {
 772                                 *err = security_xfrm_policy_delete(pol);
 773                                 if (*err) {
 774                                         write_unlock_bh(&xfrm_policy_lock);
 775                                         return pol;
 776                                 }
 777                                 hlist_del(&pol->bydst);
 778                                 hlist_del(&pol->byidx);
 779                                 xfrm_policy_count[dir]--;
 780                         }
 781                         ret = pol;
 782                         break;
 783                 }
 784         }
 785         write_unlock_bh(&xfrm_policy_lock);
 786
 787         if (ret && delete) {
 788                 atomic_inc(&flow_cache_genid);
 789                 xfrm_policy_kill(ret);
 790         }
 791         return ret;
 792 }
 793 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
 794
 795 struct xfrm_policy *xfrm_policy_byid(u8 type, int dir, u32 id, int delete,
 796                                      int *err)
 797 {
 798         struct xfrm_policy *pol, *ret;
 799         struct hlist_head *chain;
 800         struct hlist_node *entry;
 801
 802         *err = -ENOENT;
 803         if (xfrm_policy_id2dir(id) != dir)
 804                 return NULL;
 805
 806         *err = 0;
 807         write_lock_bh(&xfrm_policy_lock);
 808         chain = xfrm_policy_byidx + idx_hash(id);
 809         ret = NULL;
 810         hlist_for_each_entry(pol, entry, chain, byidx) {
 811                 if (pol->type == type && pol->index == id) {
 812                         xfrm_pol_hold(pol);
 813                         if (delete) {
 814                                 *err = security_xfrm_policy_delete(pol);
 815                                 if (*err) {
 816                                         write_unlock_bh(&xfrm_policy_lock);
 817                                         return pol;
 818                                 }
 819                                 hlist_del(&pol->bydst);
 820                                 hlist_del(&pol->byidx);
 821                                 xfrm_policy_count[dir]--;
 822                         }
 823                         ret = pol;
 824                         break;
 825                 }
 826         }
 827         write_unlock_bh(&xfrm_policy_lock);
 828
 829         if (ret && delete) {
 830                 atomic_inc(&flow_cache_genid);
 831                 xfrm_policy_kill(ret);
 832         }
 833         return ret;
 834 }
 835 EXPORT_SYMBOL(xfrm_policy_byid);
 836
 837 #ifdef CONFIG_SECURITY_NETWORK_XFRM
 838 static inline int
 839 xfrm_policy_flush_secctx_check(u8 type, struct xfrm_audit *audit_info)
 840 {
 841         int dir, err = 0;
 842
 843         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 844                 struct xfrm_policy *pol;
 845                 struct hlist_node *entry;
 846                 int i;
 847
 848                 hlist_for_each_entry(pol, entry,
 849                                      &xfrm_policy_inexact[dir], bydst) {
 850                         if (pol->type != type)
 851                                 continue;
 852                         err = security_xfrm_policy_delete(pol);
 853                         if (err) {
 854                                 xfrm_audit_log(audit_info->loginuid,
 855                                                audit_info->secid,
 856                                                AUDIT_MAC_IPSEC_DELSPD, 0,
 857                                                pol, NULL);
 858                                 return err;
 859                         }
 860                 }
 861                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
 862                         hlist_for_each_entry(pol, entry,
 863                                              xfrm_policy_bydst[dir].table + i,
 864                                              bydst) {
 865                                 if (pol->type != type)
 866                                         continue;
 867                                 err = security_xfrm_policy_delete(pol);
 868                                 if (err) {
 869                                         xfrm_audit_log(audit_info->loginuid,
 870                                                        audit_info->secid,
 871                                                        AUDIT_MAC_IPSEC_DELSPD,
 872                                                        0, pol, NULL);
 873                                         return err;
 874                                 }
 875                         }
 876                 }
 877         }
 878         return err;
 879 }
 880 #else
 881 static inline int
 882 xfrm_policy_flush_secctx_check(u8 type, struct xfrm_audit *audit_info)
 883 {
 884         return 0;
 885 }
 886 #endif
 887
 888 int xfrm_policy_flush(u8 type, struct xfrm_audit *audit_info)
 889 {
 890         int dir, err = 0;
 891
 892         write_lock_bh(&xfrm_policy_lock);
 893
 894         err = xfrm_policy_flush_secctx_check(type, audit_info);
 895         if (err)
 896                 goto out;
 897
 898         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 899                 struct xfrm_policy *pol;
 900                 struct hlist_node *entry;
 901                 int i, killed;
 902
 903                 killed = 0;
 904         again1:
 905                 hlist_for_each_entry(pol, entry,
 906                                      &xfrm_policy_inexact[dir], bydst) {
 907                         if (pol->type != type)
 908                                 continue;
 909                         hlist_del(&pol->bydst);
 910                         hlist_del(&pol->byidx);
 911                         write_unlock_bh(&xfrm_policy_lock);
 912
 913                         xfrm_audit_log(audit_info->loginuid, audit_info->secid,
 914                                        AUDIT_MAC_IPSEC_DELSPD, 1, pol, NULL);
 915
 916                         xfrm_policy_kill(pol);
 917                         killed++;
 918
 919                         write_lock_bh(&xfrm_policy_lock);
 920                         goto again1;
 921                 }
 922
 923                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
 924         again2:
 925                         hlist_for_each_entry(pol, entry,
 926                                              xfrm_policy_bydst[dir].table + i,
 927                                              bydst) {
 928                                 if (pol->type != type)
 929                                         continue;
 930                                 hlist_del(&pol->bydst);
 931                                 hlist_del(&pol->byidx);
 932                                 write_unlock_bh(&xfrm_policy_lock);
 933
 934                                 xfrm_audit_log(audit_info->loginuid,
 935                                                audit_info->secid,
 936                                                AUDIT_MAC_IPSEC_DELSPD, 1,
 937                                                pol, NULL);
 938
 939                                 xfrm_policy_kill(pol);
 940                                 killed++;
 941
 942                                 write_lock_bh(&xfrm_policy_lock);
 943                                 goto again2;
 944                         }
 945                 }
 946
 947                 xfrm_policy_count[dir] -= killed;
 948         }
 949         atomic_inc(&flow_cache_genid);
 950 out:
 951         write_unlock_bh(&xfrm_policy_lock);
 952         return err;
 953 }
 954 EXPORT_SYMBOL(xfrm_policy_flush);
 955
 956 int xfrm_policy_walk(u8 type, int (*func)(struct xfrm_policy *, int, int, void*),
 957                      void *data)
 958 {
 959         struct xfrm_policy *pol, *last = NULL;
 960         struct hlist_node *entry;
 961         int dir, last_dir = 0, count, error;
 962
 963         read_lock_bh(&xfrm_policy_lock);
 964         count = 0;
 965
 966         for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
 967                 struct hlist_head *table = xfrm_policy_bydst[dir].table;
 968                 int i;
 969
 970                 hlist_for_each_entry(pol, entry,
 971                                      &xfrm_policy_inexact[dir], bydst) {
 972                         if (pol->type != type)
 973                                 continue;
 974                         if (last) {
 975                                 error = func(last, last_dir % XFRM_POLICY_MAX,
 976                                              count, data);
 977                                 if (error)
 978                                         goto out;
 979                         }
 980                         last = pol;
 981                         last_dir = dir;
 982                         count++;
 983                 }
 984                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
 985                         hlist_for_each_entry(pol, entry, table + i, bydst) {
 986                                 if (pol->type != type)
 987                                         continue;
 988                                 if (last) {
 989                                         error = func(last, last_dir % XFRM_POLICY_MAX,
 990                                                      count, data);
 991                                         if (error)
 992                                                 goto out;
 993                                 }
 994                                 last = pol;
 995                                 last_dir = dir;
 996                                 count++;
 997                         }
 998                 }
 999         }
1000         if (count == 0) {
1001                 error = -ENOENT;
1002                 goto out;
1003         }
1004         error = func(last, last_dir % XFRM_POLICY_MAX, 0, data);
1005 out:
1006         read_unlock_bh(&xfrm_policy_lock);
1007         return error;
1008 }
1009 EXPORT_SYMBOL(xfrm_policy_walk);
1010
1011 /*
1012  * Find policy to apply to this flow.
1013  *
1014  * Returns 0 if policy found, else an -errno.
1015  */
1016 static int xfrm_policy_match(struct xfrm_policy *pol, struct flowi *fl,
1017                              u8 type, u16 family, int dir)
1018 {
1019         struct xfrm_selector *sel = &pol->selector;
1020         int match, ret = -ESRCH;
1021
1022         if (pol->family != family ||
1023             pol->type != type)
1024                 return ret;
1025
1026         match = xfrm_selector_match(sel, fl, family);
1027         if (match)
1028                 ret = security_xfrm_policy_lookup(pol, fl->secid, dir);
1029
1030         return ret;
1031 }
1032
1033 static struct xfrm_policy *xfrm_policy_lookup_bytype(u8 type, struct flowi *fl,
1034                                                      u16 family, u8 dir)
1035 {
1036         int err;
1037         struct xfrm_policy *pol, *ret;
1038         xfrm_address_t *daddr, *saddr;
1039         struct hlist_node *entry;
1040         struct hlist_head *chain;
1041         u32 priority = ~0U;
1042
1043         daddr = xfrm_flowi_daddr(fl, family);
1044         saddr = xfrm_flowi_saddr(fl, family);
1045         if (unlikely(!daddr || !saddr))
1046                 return NULL;
1047
1048         read_lock_bh(&xfrm_policy_lock);
1049         chain = policy_hash_direct(daddr, saddr, family, dir);
1050         ret = NULL;
1051         hlist_for_each_entry(pol, entry, chain, bydst) {
1052                 err = xfrm_policy_match(pol, fl, type, family, dir);
1053                 if (err) {
1054                         if (err == -ESRCH)
1055                                 continue;
1056                         else {
1057                                 ret = ERR_PTR(err);
1058                                 goto fail;
1059                         }
1060                 } else {
1061                         ret = pol;
1062                         priority = ret->priority;
1063                         break;
1064                 }
1065         }
1066         chain = &xfrm_policy_inexact[dir];
1067         hlist_for_each_entry(pol, entry, chain, bydst) {
1068                 err = xfrm_policy_match(pol, fl, type, family, dir);
1069                 if (err) {
1070                         if (err == -ESRCH)
1071                                 continue;
1072                         else {
1073                                 ret = ERR_PTR(err);
1074                                 goto fail;
1075                         }
1076                 } else if (pol->priority < priority) {
1077                         ret = pol;
1078                         break;
1079                 }
1080         }
1081         if (ret)
1082                 xfrm_pol_hold(ret);
1083 fail:
1084         read_unlock_bh(&xfrm_policy_lock);
1085
1086         return ret;
1087 }
1088
1089 static int xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
1090                                void **objp, atomic_t **obj_refp)
1091 {
1092         struct xfrm_policy *pol;
1093         int err = 0;
1094
1095 #ifdef CONFIG_XFRM_SUB_POLICY
1096         pol = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_SUB, fl, family, dir);
1097         if (IS_ERR(pol)) {
1098                 err = PTR_ERR(pol);
1099                 pol = NULL;
1100         }
1101         if (pol || err)
1102                 goto end;
1103 #endif
1104         pol = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN, fl, family, dir);
1105         if (IS_ERR(pol)) {
1106                 err = PTR_ERR(pol);
1107                 pol = NULL;
1108         }
1109 #ifdef CONFIG_XFRM_SUB_POLICY
1110 end:
1111 #endif
1112         if ((*objp = (void *) pol) != NULL)
1113                 *obj_refp = &pol->refcnt;
1114         return err;
1115 }
1116
1117 static inline int policy_to_flow_dir(int dir)
1118 {
1119         if (XFRM_POLICY_IN == FLOW_DIR_IN &&
1120             XFRM_POLICY_OUT == FLOW_DIR_OUT &&
1121             XFRM_POLICY_FWD == FLOW_DIR_FWD)
1122                 return dir;
1123         switch (dir) {
1124         default:
1125         case XFRM_POLICY_IN:
1126                 return FLOW_DIR_IN;
1127         case XFRM_POLICY_OUT:
1128                 return FLOW_DIR_OUT;
1129         case XFRM_POLICY_FWD:
1130                 return FLOW_DIR_FWD;
1131         }
1132 }
1133
1134 static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl)
1135 {
1136         struct xfrm_policy *pol;
1137
1138         read_lock_bh(&xfrm_policy_lock);
1139         if ((pol = sk->sk_policy[dir]) != NULL) {
1140                 int match = xfrm_selector_match(&pol->selector, fl,
1141                                                 sk->sk_family);
1142                 int err = 0;
1143
1144                 if (match) {
1145                         err = security_xfrm_policy_lookup(pol, fl->secid,
1146                                         policy_to_flow_dir(dir));
1147                         if (!err)
1148                                 xfrm_pol_hold(pol);
1149                         else if (err == -ESRCH)
1150                                 pol = NULL;
1151                         else
1152                                 pol = ERR_PTR(err);
1153                 } else
1154                         pol = NULL;
1155         }
1156         read_unlock_bh(&xfrm_policy_lock);
1157         return pol;
1158 }
1159
1160 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
1161 {
1162         struct hlist_head *chain = policy_hash_bysel(&pol->selector,
1163                                                      pol->family, dir);
1164
1165         hlist_add_head(&pol->bydst, chain);
1166         hlist_add_head(&pol->byidx, xfrm_policy_byidx+idx_hash(pol->index));
1167         xfrm_policy_count[dir]++;
1168         xfrm_pol_hold(pol);
1169
1170         if (xfrm_bydst_should_resize(dir, NULL))
1171                 schedule_work(&xfrm_hash_work);
1172 }
1173
1174 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
1175                                                 int dir)
1176 {
1177         if (hlist_unhashed(&pol->bydst))
1178                 return NULL;
1179
1180         hlist_del(&pol->bydst);
1181         hlist_del(&pol->byidx);
1182         xfrm_policy_count[dir]--;
1183
1184         return pol;
1185 }
1186
1187 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
1188 {
1189         write_lock_bh(&xfrm_policy_lock);
1190         pol = __xfrm_policy_unlink(pol, dir);
1191         write_unlock_bh(&xfrm_policy_lock);
1192         if (pol) {
1193                 if (dir < XFRM_POLICY_MAX)
1194                         atomic_inc(&flow_cache_genid);
1195                 xfrm_policy_kill(pol);
1196                 return 0;
1197         }
1198         return -ENOENT;
1199 }
1200 EXPORT_SYMBOL(xfrm_policy_delete);
1201
1202 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
1203 {
1204         struct xfrm_policy *old_pol;
1205
1206 #ifdef CONFIG_XFRM_SUB_POLICY
1207         if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
1208                 return -EINVAL;
1209 #endif
1210
1211         write_lock_bh(&xfrm_policy_lock);
1212         old_pol = sk->sk_policy[dir];
1213         sk->sk_policy[dir] = pol;
1214         if (pol) {
1215                 pol->curlft.add_time = get_seconds();
1216                 pol->index = xfrm_gen_index(pol->type, XFRM_POLICY_MAX+dir);
1217                 __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
1218         }
1219         if (old_pol)
1220                 __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
1221         write_unlock_bh(&xfrm_policy_lock);
1222
1223         if (old_pol) {
1224                 xfrm_policy_kill(old_pol);
1225         }
1226         return 0;
1227 }
1228
1229 static struct xfrm_policy *clone_policy(struct xfrm_policy *old, int dir)
1230 {
1231         struct xfrm_policy *newp = xfrm_policy_alloc(GFP_ATOMIC);
1232
1233         if (newp) {
1234                 newp->selector = old->selector;
1235                 if (security_xfrm_policy_clone(old, newp)) {
1236                         kfree(newp);
1237                         return NULL;  /* ENOMEM */
1238                 }
1239                 newp->lft = old->lft;
1240                 newp->curlft = old->curlft;
1241                 newp->action = old->action;
1242                 newp->flags = old->flags;
1243                 newp->xfrm_nr = old->xfrm_nr;
1244                 newp->index = old->index;
1245                 newp->type = old->type;
1246                 memcpy(newp->xfrm_vec, old->xfrm_vec,
1247                        newp->xfrm_nr*sizeof(struct xfrm_tmpl));
1248                 write_lock_bh(&xfrm_policy_lock);
1249                 __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir);
1250                 write_unlock_bh(&xfrm_policy_lock);
1251                 xfrm_pol_put(newp);
1252         }
1253         return newp;
1254 }
1255
1256 int __xfrm_sk_clone_policy(struct sock *sk)
1257 {
1258         struct xfrm_policy *p0 = sk->sk_policy[0],
1259                            *p1 = sk->sk_policy[1];
1260
1261         sk->sk_policy[0] = sk->sk_policy[1] = NULL;
1262         if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL)
1263                 return -ENOMEM;
1264         if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL)
1265                 return -ENOMEM;
1266         return 0;
1267 }
1268
1269 static int
1270 xfrm_get_saddr(xfrm_address_t *local, xfrm_address_t *remote,
1271                unsigned short family)
1272 {
1273         int err;
1274         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1275
1276         if (unlikely(afinfo == NULL))
1277                 return -EINVAL;
1278         err = afinfo->get_saddr(local, remote);
1279         xfrm_policy_put_afinfo(afinfo);
1280         return err;
1281 }
1282
1283 /* Resolve list of templates for the flow, given policy. */
1284
1285 static int
1286 xfrm_tmpl_resolve_one(struct xfrm_policy *policy, struct flowi *fl,
1287                       struct xfrm_state **xfrm,
1288                       unsigned short family)
1289 {
1290         int nx;
1291         int i, error;
1292         xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
1293         xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
1294         xfrm_address_t tmp;
1295
1296         for (nx=0, i = 0; i < policy->xfrm_nr; i++) {
1297                 struct xfrm_state *x;
1298                 xfrm_address_t *remote = daddr;
1299                 xfrm_address_t *local  = saddr;
1300                 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
1301
1302                 if (tmpl->mode == XFRM_MODE_TUNNEL ||
1303                     tmpl->mode == XFRM_MODE_BEET) {
1304                         remote = &tmpl->id.daddr;
1305                         local = &tmpl->saddr;
1306                         family = tmpl->encap_family;
1307                         if (xfrm_addr_any(local, family)) {
1308                                 error = xfrm_get_saddr(&tmp, remote, family);
1309                                 if (error)
1310                                         goto fail;
1311                                 local = &tmp;
1312                         }
1313                 }
1314
1315                 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
1316
1317                 if (x && x->km.state == XFRM_STATE_VALID) {
1318                         xfrm[nx++] = x;
1319                         daddr = remote;
1320                         saddr = local;
1321                         continue;
1322                 }
1323                 if (x) {
1324                         error = (x->km.state == XFRM_STATE_ERROR ?
1325                                  -EINVAL : -EAGAIN);
1326                         xfrm_state_put(x);
1327                 }
1328
1329                 if (!tmpl->optional)
1330                         goto fail;
1331         }
1332         return nx;
1333
1334 fail:
1335         for (nx--; nx>=0; nx--)
1336                 xfrm_state_put(xfrm[nx]);
1337         return error;
1338 }
1339
1340 static int
1341 xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, struct flowi *fl,
1342                   struct xfrm_state **xfrm,
1343                   unsigned short family)
1344 {
1345         struct xfrm_state *tp[XFRM_MAX_DEPTH];
1346         struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
1347         int cnx = 0;
1348         int error;
1349         int ret;
1350         int i;
1351
1352         for (i = 0; i < npols; i++) {
1353                 if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
1354                         error = -ENOBUFS;
1355                         goto fail;
1356                 }
1357
1358                 ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
1359                 if (ret < 0) {
1360                         error = ret;
1361                         goto fail;
1362                 } else
1363                         cnx += ret;
1364         }
1365
1366         /* found states are sorted for outbound processing */
1367         if (npols > 1)
1368                 xfrm_state_sort(xfrm, tpp, cnx, family);
1369
1370         return cnx;
1371
1372  fail:
1373         for (cnx--; cnx>=0; cnx--)
1374                 xfrm_state_put(tpp[cnx]);
1375         return error;
1376
1377 }
1378
1379 /* Check that the bundle accepts the flow and its components are
1380  * still valid.
1381  */
1382
1383 static struct dst_entry *
1384 xfrm_find_bundle(struct flowi *fl, struct xfrm_policy *policy, unsigned short family)
1385 {
1386         struct dst_entry *x;
1387         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1388         if (unlikely(afinfo == NULL))
1389                 return ERR_PTR(-EINVAL);
1390         x = afinfo->find_bundle(fl, policy);
1391         xfrm_policy_put_afinfo(afinfo);
1392         return x;
1393 }
1394
1395 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
1396  * all the metrics... Shortly, bundle a bundle.
1397  */
1398
1399 static int
1400 xfrm_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
1401                    struct flowi *fl, struct dst_entry **dst_p,
1402                    unsigned short family)
1403 {
1404         int err;
1405         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1406         if (unlikely(afinfo == NULL))
1407                 return -EINVAL;
1408         err = afinfo->bundle_create(policy, xfrm, nx, fl, dst_p);
1409         xfrm_policy_put_afinfo(afinfo);
1410         return err;
1411 }
1412
1413 static int inline
1414 xfrm_dst_alloc_copy(void **target, void *src, int size)
1415 {
1416         if (!*target) {
1417                 *target = kmalloc(size, GFP_ATOMIC);
1418                 if (!*target)
1419                         return -ENOMEM;
1420         }
1421         memcpy(*target, src, size);
1422         return 0;
1423 }
1424
1425 static int inline
1426 xfrm_dst_update_parent(struct dst_entry *dst, struct xfrm_selector *sel)
1427 {
1428 #ifdef CONFIG_XFRM_SUB_POLICY
1429         struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1430         return xfrm_dst_alloc_copy((void **)&(xdst->partner),
1431                                    sel, sizeof(*sel));
1432 #else
1433         return 0;
1434 #endif
1435 }
1436
1437 static int inline
1438 xfrm_dst_update_origin(struct dst_entry *dst, struct flowi *fl)
1439 {
1440 #ifdef CONFIG_XFRM_SUB_POLICY
1441         struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1442         return xfrm_dst_alloc_copy((void **)&(xdst->origin), fl, sizeof(*fl));
1443 #else
1444         return 0;
1445 #endif
1446 }
1447
1448 static int stale_bundle(struct dst_entry *dst);
1449
1450 /* Main function: finds/creates a bundle for given flow.
1451  *
1452  * At the moment we eat a raw IP route. Mostly to speed up lookups
1453  * on interfaces with disabled IPsec.
1454  */
1455 int __xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
1456                   struct sock *sk, int flags)
1457 {
1458         struct xfrm_policy *policy;
1459         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1460         int npols;
1461         int pol_dead;
1462         int xfrm_nr;
1463         int pi;
1464         struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
1465         struct dst_entry *dst, *dst_orig = *dst_p;
1466         int nx = 0;
1467         int err;
1468         u32 genid;
1469         u16 family;
1470         u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
1471
1472 restart:
1473         genid = atomic_read(&flow_cache_genid);
1474         policy = NULL;
1475         for (pi = 0; pi < ARRAY_SIZE(pols); pi++)
1476                 pols[pi] = NULL;
1477         npols = 0;
1478         pol_dead = 0;
1479         xfrm_nr = 0;
1480
1481         if (sk && sk->sk_policy[1]) {
1482                 policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
1483                 if (IS_ERR(policy))
1484                         return PTR_ERR(policy);
1485         }
1486
1487         if (!policy) {
1488                 /* To accelerate a bit...  */
1489                 if ((dst_orig->flags & DST_NOXFRM) ||
1490                     !xfrm_policy_count[XFRM_POLICY_OUT])
1491                         return 0;
1492
1493                 policy = flow_cache_lookup(fl, dst_orig->ops->family,
1494                                            dir, xfrm_policy_lookup);
1495                 if (IS_ERR(policy))
1496                         return PTR_ERR(policy);
1497         }
1498
1499         if (!policy)
1500                 return 0;
1501
1502         family = dst_orig->ops->family;
1503         policy->curlft.use_time = get_seconds();
1504         pols[0] = policy;
1505         npols ++;
1506         xfrm_nr += pols[0]->xfrm_nr;
1507
1508         switch (policy->action) {
1509         case XFRM_POLICY_BLOCK:
1510                 /* Prohibit the flow */
1511                 err = -EPERM;
1512                 goto error;
1513
1514         case XFRM_POLICY_ALLOW:
1515 #ifndef CONFIG_XFRM_SUB_POLICY
1516                 if (policy->xfrm_nr == 0) {
1517                         /* Flow passes not transformed. */
1518                         xfrm_pol_put(policy);
1519                         return 0;
1520                 }
1521 #endif
1522
1523                 /* Try to find matching bundle.
1524                  *
1525                  * LATER: help from flow cache. It is optional, this
1526                  * is required only for output policy.
1527                  */
1528                 dst = xfrm_find_bundle(fl, policy, family);
1529                 if (IS_ERR(dst)) {
1530                         err = PTR_ERR(dst);
1531                         goto error;
1532                 }
1533
1534                 if (dst)
1535                         break;
1536
1537 #ifdef CONFIG_XFRM_SUB_POLICY
1538                 if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1539                         pols[1] = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN,
1540                                                             fl, family,
1541                                                             XFRM_POLICY_OUT);
1542                         if (pols[1]) {
1543                                 if (IS_ERR(pols[1])) {
1544                                         err = PTR_ERR(pols[1]);
1545                                         goto error;
1546                                 }
1547                                 if (pols[1]->action == XFRM_POLICY_BLOCK) {
1548                                         err = -EPERM;
1549                                         goto error;
1550                                 }
1551                                 npols ++;
1552                                 xfrm_nr += pols[1]->xfrm_nr;
1553                         }
1554                 }
1555
1556                 /*
1557                  * Because neither flowi nor bundle information knows about
1558                  * transformation template size. On more than one policy usage
1559                  * we can realize whether all of them is bypass or not after
1560                  * they are searched. See above not-transformed bypass
1561                  * is surrounded by non-sub policy configuration, too.
1562                  */
1563                 if (xfrm_nr == 0) {
1564                         /* Flow passes not transformed. */
1565                         xfrm_pols_put(pols, npols);
1566                         return 0;
1567                 }
1568
1569 #endif
1570                 nx = xfrm_tmpl_resolve(pols, npols, fl, xfrm, family);
1571
1572                 if (unlikely(nx<0)) {
1573                         err = nx;
1574                         if (err == -EAGAIN && sysctl_xfrm_larval_drop) {
1575                                 /* EREMOTE tells the caller to generate
1576                                  * a one-shot blackhole route.
1577                                  */
1578                                 xfrm_pol_put(policy);
1579                                 return -EREMOTE;
1580                         }
1581                         if (err == -EAGAIN && flags) {
1582                                 DECLARE_WAITQUEUE(wait, current);
1583
1584                                 add_wait_queue(&km_waitq, &wait);
1585                                 set_current_state(TASK_INTERRUPTIBLE);
1586                                 schedule();
1587                                 set_current_state(TASK_RUNNING);
1588                                 remove_wait_queue(&km_waitq, &wait);
1589
1590                                 nx = xfrm_tmpl_resolve(pols, npols, fl, xfrm, family);
1591
1592                                 if (nx == -EAGAIN && signal_pending(current)) {
1593                                         err = -ERESTART;
1594                                         goto error;
1595                                 }
1596                                 if (nx == -EAGAIN ||
1597                                     genid != atomic_read(&flow_cache_genid)) {
1598                                         xfrm_pols_put(pols, npols);
1599                                         goto restart;
1600                                 }
1601                                 err = nx;
1602                         }
1603                         if (err < 0)
1604                                 goto error;
1605                 }
1606                 if (nx == 0) {
1607                         /* Flow passes not transformed. */
1608                         xfrm_pols_put(pols, npols);
1609                         return 0;
1610                 }
1611
1612                 dst = dst_orig;
1613                 err = xfrm_bundle_create(policy, xfrm, nx, fl, &dst, family);
1614
1615                 if (unlikely(err)) {
1616                         int i;
1617                         for (i=0; i<nx; i++)
1618                                 xfrm_state_put(xfrm[i]);
1619                         goto error;
1620                 }
1621
1622                 for (pi = 0; pi < npols; pi++) {
1623                         read_lock_bh(&pols[pi]->lock);
1624                         pol_dead |= pols[pi]->dead;
1625                         read_unlock_bh(&pols[pi]->lock);
1626                 }
1627
1628                 write_lock_bh(&policy->lock);
1629                 if (unlikely(pol_dead || stale_bundle(dst))) {
1630                         /* Wow! While we worked on resolving, this
1631                          * policy has gone. Retry. It is not paranoia,
1632                          * we just cannot enlist new bundle to dead object.
1633                          * We can't enlist stable bundles either.
1634                          */
1635                         write_unlock_bh(&policy->lock);
1636                         if (dst)
1637                                 dst_free(dst);
1638
1639                         err = -EHOSTUNREACH;
1640                         goto error;
1641                 }
1642
1643                 if (npols > 1)
1644                         err = xfrm_dst_update_parent(dst, &pols[1]->selector);
1645                 else
1646                         err = xfrm_dst_update_origin(dst, fl);
1647                 if (unlikely(err)) {
1648                         write_unlock_bh(&policy->lock);
1649                         if (dst)
1650                                 dst_free(dst);
1651                         goto error;
1652                 }
1653
1654                 dst->next = policy->bundles;
1655                 policy->bundles = dst;
1656                 dst_hold(dst);
1657                 write_unlock_bh(&policy->lock);
1658         }
1659         *dst_p = dst;
1660         dst_release(dst_orig);
1661         xfrm_pols_put(pols, npols);
1662         return 0;
1663
1664 error:
1665         dst_release(dst_orig);
1666         xfrm_pols_put(pols, npols);
1667         *dst_p = NULL;
1668         return err;
1669 }
1670 EXPORT_SYMBOL(__xfrm_lookup);
1671
1672 int xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
1673                 struct sock *sk, int flags)
1674 {
1675         int err = __xfrm_lookup(dst_p, fl, sk, flags);
1676
1677         if (err == -EREMOTE) {
1678                 dst_release(*dst_p);
1679                 *dst_p = NULL;
1680                 err = -EAGAIN;
1681         }
1682
1683         return err;
1684 }
1685 EXPORT_SYMBOL(xfrm_lookup);
1686
1687 static inline int
1688 xfrm_secpath_reject(int idx, struct sk_buff *skb, struct flowi *fl)
1689 {
1690         struct xfrm_state *x;
1691         int err;
1692
1693         if (!skb->sp || idx < 0 || idx >= skb->sp->len)
1694                 return 0;
1695         x = skb->sp->xvec[idx];
1696         if (!x->type->reject)
1697                 return 0;
1698         xfrm_state_hold(x);
1699         err = x->type->reject(x, skb, fl);
1700         xfrm_state_put(x);
1701         return err;
1702 }
1703
1704 /* When skb is transformed back to its "native" form, we have to
1705  * check policy restrictions. At the moment we make this in maximally
1706  * stupid way. Shame on me. :-) Of course, connected sockets must
1707  * have policy cached at them.
1708  */
1709
1710 static inline int
1711 xfrm_state_ok(struct xfrm_tmpl *tmpl, struct xfrm_state *x,
1712               unsigned short family)
1713 {
1714         if (xfrm_state_kern(x))
1715                 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
1716         return  x->id.proto == tmpl->id.proto &&
1717                 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
1718                 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
1719                 x->props.mode == tmpl->mode &&
1720                 ((tmpl->aalgos & (1<<x->props.aalgo)) ||
1721                  !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
1722                 !(x->props.mode != XFRM_MODE_TRANSPORT &&
1723                   xfrm_state_addr_cmp(tmpl, x, family));
1724 }
1725
1726 /*
1727  * 0 or more than 0 is returned when validation is succeeded (either bypass
1728  * because of optional transport mode, or next index of the mathced secpath
1729  * state with the template.
1730  * -1 is returned when no matching template is found.
1731  * Otherwise "-2 - errored_index" is returned.
1732  */
1733 static inline int
1734 xfrm_policy_ok(struct xfrm_tmpl *tmpl, struct sec_path *sp, int start,
1735                unsigned short family)
1736 {
1737         int idx = start;
1738
1739         if (tmpl->optional) {
1740                 if (tmpl->mode == XFRM_MODE_TRANSPORT)
1741                         return start;
1742         } else
1743                 start = -1;
1744         for (; idx < sp->len; idx++) {
1745                 if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
1746                         return ++idx;
1747                 if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
1748                         if (start == -1)
1749                                 start = -2-idx;
1750                         break;
1751                 }
1752         }
1753         return start;
1754 }
1755
1756 int
1757 xfrm_decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family)
1758 {
1759         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1760         int err;
1761
1762         if (unlikely(afinfo == NULL))
1763                 return -EAFNOSUPPORT;
1764
1765         afinfo->decode_session(skb, fl);
1766         err = security_xfrm_decode_session(skb, &fl->secid);
1767         xfrm_policy_put_afinfo(afinfo);
1768         return err;
1769 }
1770 EXPORT_SYMBOL(xfrm_decode_session);
1771
1772 static inline int secpath_has_nontransport(struct sec_path *sp, int k, int *idxp)
1773 {
1774         for (; k < sp->len; k++) {
1775                 if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
1776                         *idxp = k;
1777                         return 1;
1778                 }
1779         }
1780
1781         return 0;
1782 }
1783
1784 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
1785                         unsigned short family)
1786 {
1787         struct xfrm_policy *pol;
1788         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1789         int npols = 0;
1790         int xfrm_nr;
1791         int pi;
1792         struct flowi fl;
1793         u8 fl_dir = policy_to_flow_dir(dir);
1794         int xerr_idx = -1;
1795
1796         if (xfrm_decode_session(skb, &fl, family) < 0)
1797                 return 0;
1798         nf_nat_decode_session(skb, &fl, family);
1799
1800         /* First, check used SA against their selectors. */
1801         if (skb->sp) {
1802                 int i;
1803
1804                 for (i=skb->sp->len-1; i>=0; i--) {
1805                         struct xfrm_state *x = skb->sp->xvec[i];
1806                         if (!xfrm_selector_match(&x->sel, &fl, family))
1807                                 return 0;
1808                 }
1809         }
1810
1811         pol = NULL;
1812         if (sk && sk->sk_policy[dir]) {
1813                 pol = xfrm_sk_policy_lookup(sk, dir, &fl);
1814                 if (IS_ERR(pol))
1815                         return 0;
1816         }
1817
1818         if (!pol)
1819                 pol = flow_cache_lookup(&fl, family, fl_dir,
1820                                         xfrm_policy_lookup);
1821
1822         if (IS_ERR(pol))
1823                 return 0;
1824
1825         if (!pol) {
1826                 if (skb->sp && secpath_has_nontransport(skb->sp, 0, &xerr_idx)) {
1827                         xfrm_secpath_reject(xerr_idx, skb, &fl);
1828                         return 0;
1829                 }
1830                 return 1;
1831         }
1832
1833         pol->curlft.use_time = get_seconds();
1834
1835         pols[0] = pol;
1836         npols ++;
1837 #ifdef CONFIG_XFRM_SUB_POLICY
1838         if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1839                 pols[1] = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN,
1840                                                     &fl, family,
1841                                                     XFRM_POLICY_IN);
1842                 if (pols[1]) {
1843                         if (IS_ERR(pols[1]))
1844                                 return 0;
1845                         pols[1]->curlft.use_time = get_seconds();
1846                         npols ++;
1847                 }
1848         }
1849 #endif
1850
1851         if (pol->action == XFRM_POLICY_ALLOW) {
1852                 struct sec_path *sp;
1853                 static struct sec_path dummy;
1854                 struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
1855                 struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
1856                 struct xfrm_tmpl **tpp = tp;
1857                 int ti = 0;
1858                 int i, k;
1859
1860                 if ((sp = skb->sp) == NULL)
1861                         sp = &dummy;
1862
1863                 for (pi = 0; pi < npols; pi++) {
1864                         if (pols[pi] != pol &&
1865                             pols[pi]->action != XFRM_POLICY_ALLOW)
1866                                 goto reject;
1867                         if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH)
1868                                 goto reject_error;
1869                         for (i = 0; i < pols[pi]->xfrm_nr; i++)
1870                                 tpp[ti++] = &pols[pi]->xfrm_vec[i];
1871                 }
1872                 xfrm_nr = ti;
1873                 if (npols > 1) {
1874                         xfrm_tmpl_sort(stp, tpp, xfrm_nr, family);
1875                         tpp = stp;
1876                 }
1877
1878                 /* For each tunnel xfrm, find the first matching tmpl.
1879                  * For each tmpl before that, find corresponding xfrm.
1880                  * Order is _important_. Later we will implement
1881                  * some barriers, but at the moment barriers
1882                  * are implied between each two transformations.
1883                  */
1884                 for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
1885                         k = xfrm_policy_ok(tpp[i], sp, k, family);
1886                         if (k < 0) {
1887                                 if (k < -1)
1888                                         /* "-2 - errored_index" returned */
1889                                         xerr_idx = -(2+k);
1890                                 goto reject;
1891                         }
1892                 }
1893
1894                 if (secpath_has_nontransport(sp, k, &xerr_idx))
1895                         goto reject;
1896
1897                 xfrm_pols_put(pols, npols);
1898                 return 1;
1899         }
1900
1901 reject:
1902         xfrm_secpath_reject(xerr_idx, skb, &fl);
1903 reject_error:
1904         xfrm_pols_put(pols, npols);
1905         return 0;
1906 }
1907 EXPORT_SYMBOL(__xfrm_policy_check);
1908
1909 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
1910 {
1911         struct flowi fl;
1912
1913         if (xfrm_decode_session(skb, &fl, family) < 0)
1914                 return 0;
1915
1916         return xfrm_lookup(&skb->dst, &fl, NULL, 0) == 0;
1917 }
1918 EXPORT_SYMBOL(__xfrm_route_forward);
1919
1920 /* Optimize later using cookies and generation ids. */
1921
1922 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
1923 {
1924         /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
1925          * to "-1" to force all XFRM destinations to get validated by
1926          * dst_ops->check on every use.  We do this because when a
1927          * normal route referenced by an XFRM dst is obsoleted we do
1928          * not go looking around for all parent referencing XFRM dsts
1929          * so that we can invalidate them.  It is just too much work.
1930          * Instead we make the checks here on every use.  For example:
1931          *
1932          *      XFRM dst A --> IPv4 dst X
1933          *
1934          * X is the "xdst->route" of A (X is also the "dst->path" of A
1935          * in this example).  If X is marked obsolete, "A" will not
1936          * notice.  That's what we are validating here via the
1937          * stale_bundle() check.
1938          *
1939          * When a policy's bundle is pruned, we dst_free() the XFRM
1940          * dst which causes it's ->obsolete field to be set to a
1941          * positive non-zero integer.  If an XFRM dst has been pruned
1942          * like this, we want to force a new route lookup.
1943          */
1944         if (dst->obsolete < 0 && !stale_bundle(dst))
1945                 return dst;
1946
1947         return NULL;
1948 }
1949
1950 static int stale_bundle(struct dst_entry *dst)
1951 {
1952         return !xfrm_bundle_ok(NULL, (struct xfrm_dst *)dst, NULL, AF_UNSPEC, 0);
1953 }
1954
1955 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
1956 {
1957         while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
1958                 dst->dev = &loopback_dev;
1959                 dev_hold(&loopback_dev);
1960                 dev_put(dev);
1961         }
1962 }
1963 EXPORT_SYMBOL(xfrm_dst_ifdown);
1964
1965 static void xfrm_link_failure(struct sk_buff *skb)
1966 {
1967         /* Impossible. Such dst must be popped before reaches point of failure. */
1968         return;
1969 }
1970
1971 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
1972 {
1973         if (dst) {
1974                 if (dst->obsolete) {
1975                         dst_release(dst);
1976                         dst = NULL;
1977                 }
1978         }
1979         return dst;
1980 }
1981
1982 static void prune_one_bundle(struct xfrm_policy *pol, int (*func)(struct dst_entry *), struct dst_entry **gc_list_p)
1983 {
1984         struct dst_entry *dst, **dstp;
1985
1986         write_lock(&pol->lock);
1987         dstp = &pol->bundles;
1988         while ((dst=*dstp) != NULL) {
1989                 if (func(dst)) {
1990                         *dstp = dst->next;
1991                         dst->next = *gc_list_p;
1992                         *gc_list_p = dst;
1993                 } else {
1994                         dstp = &dst->next;
1995                 }
1996         }
1997         write_unlock(&pol->lock);
1998 }
1999
2000 static void xfrm_prune_bundles(int (*func)(struct dst_entry *))
2001 {
2002         struct dst_entry *gc_list = NULL;
2003         int dir;
2004
2005         read_lock_bh(&xfrm_policy_lock);
2006         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
2007                 struct xfrm_policy *pol;
2008                 struct hlist_node *entry;
2009                 struct hlist_head *table;
2010                 int i;
2011
2012                 hlist_for_each_entry(pol, entry,
2013                                      &xfrm_policy_inexact[dir], bydst)
2014                         prune_one_bundle(pol, func, &gc_list);
2015
2016                 table = xfrm_policy_bydst[dir].table;
2017                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
2018                         hlist_for_each_entry(pol, entry, table + i, bydst)
2019                                 prune_one_bundle(pol, func, &gc_list);
2020                 }
2021         }
2022         read_unlock_bh(&xfrm_policy_lock);
2023
2024         while (gc_list) {
2025                 struct dst_entry *dst = gc_list;
2026                 gc_list = dst->next;
2027                 dst_free(dst);
2028         }
2029 }
2030
2031 static int unused_bundle(struct dst_entry *dst)
2032 {
2033         return !atomic_read(&dst->__refcnt);
2034 }
2035
2036 static void __xfrm_garbage_collect(void)
2037 {
2038         xfrm_prune_bundles(unused_bundle);
2039 }
2040
2041 static int xfrm_flush_bundles(void)
2042 {
2043         xfrm_prune_bundles(stale_bundle);
2044         return 0;
2045 }
2046
2047 void xfrm_init_pmtu(struct dst_entry *dst)
2048 {
2049         do {
2050                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2051                 u32 pmtu, route_mtu_cached;
2052
2053                 pmtu = dst_mtu(dst->child);
2054                 xdst->child_mtu_cached = pmtu;
2055
2056                 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
2057
2058                 route_mtu_cached = dst_mtu(xdst->route);
2059                 xdst->route_mtu_cached = route_mtu_cached;
2060
2061                 if (pmtu > route_mtu_cached)
2062                         pmtu = route_mtu_cached;
2063
2064                 dst->metrics[RTAX_MTU-1] = pmtu;
2065         } while ((dst = dst->next));
2066 }
2067
2068 EXPORT_SYMBOL(xfrm_init_pmtu);
2069
2070 /* Check that the bundle accepts the flow and its components are
2071  * still valid.
2072  */
2073
2074 int xfrm_bundle_ok(struct xfrm_policy *pol, struct xfrm_dst *first,
2075                 struct flowi *fl, int family, int strict)
2076 {
2077         struct dst_entry *dst = &first->u.dst;
2078         struct xfrm_dst *last;
2079         u32 mtu;
2080
2081         if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) ||
2082             (dst->dev && !netif_running(dst->dev)))
2083                 return 0;
2084 #ifdef CONFIG_XFRM_SUB_POLICY
2085         if (fl) {
2086                 if (first->origin && !flow_cache_uli_match(first->origin, fl))
2087                         return 0;
2088                 if (first->partner &&
2089                     !xfrm_selector_match(first->partner, fl, family))
2090                         return 0;
2091         }
2092 #endif
2093
2094         last = NULL;
2095
2096         do {
2097                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
2098
2099                 if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family))
2100                         return 0;
2101                 if (fl && pol &&
2102                     !security_xfrm_state_pol_flow_match(dst->xfrm, pol, fl))
2103                         return 0;
2104                 if (dst->xfrm->km.state != XFRM_STATE_VALID)
2105                         return 0;
2106                 if (xdst->genid != dst->xfrm->genid)
2107                         return 0;
2108
2109                 if (strict && fl && dst->xfrm->props.mode != XFRM_MODE_TUNNEL &&
2110                     !xfrm_state_addr_flow_check(dst->xfrm, fl, family))
2111                         return 0;
2112
2113                 mtu = dst_mtu(dst->child);
2114                 if (xdst->child_mtu_cached != mtu) {
2115                         last = xdst;
2116                         xdst->child_mtu_cached = mtu;
2117                 }
2118
2119                 if (!dst_check(xdst->route, xdst->route_cookie))
2120                         return 0;
2121                 mtu = dst_mtu(xdst->route);
2122                 if (xdst->route_mtu_cached != mtu) {
2123                         last = xdst;
2124                         xdst->route_mtu_cached = mtu;
2125                 }
2126
2127                 dst = dst->child;
2128         } while (dst->xfrm);
2129
2130         if (likely(!last))
2131                 return 1;
2132
2133         mtu = last->child_mtu_cached;
2134         for (;;) {
2135                 dst = &last->u.dst;
2136
2137                 mtu = xfrm_state_mtu(dst->xfrm, mtu);
2138                 if (mtu > last->route_mtu_cached)
2139                         mtu = last->route_mtu_cached;
2140                 dst->metrics[RTAX_MTU-1] = mtu;
2141
2142                 if (last == first)
2143                         break;
2144
2145                 last = (struct xfrm_dst *)last->u.dst.next;
2146                 last->child_mtu_cached = mtu;
2147         }
2148
2149         return 1;
2150 }
2151
2152 EXPORT_SYMBOL(xfrm_bundle_ok);
2153
2154 #ifdef CONFIG_AUDITSYSCALL
2155 /* Audit addition and deletion of SAs and ipsec policy */
2156
2157 void xfrm_audit_log(uid_t auid, u32 sid, int type, int result,
2158                     struct xfrm_policy *xp, struct xfrm_state *x)
2159 {
2160
2161         char *secctx;
2162         u32 secctx_len;
2163         struct xfrm_sec_ctx *sctx = NULL;
2164         struct audit_buffer *audit_buf;
2165         int family;
2166         extern int audit_enabled;
2167
2168         if (audit_enabled == 0)
2169                 return;
2170
2171         BUG_ON((type == AUDIT_MAC_IPSEC_ADDSA ||
2172                 type == AUDIT_MAC_IPSEC_DELSA) && !x);
2173         BUG_ON((type == AUDIT_MAC_IPSEC_ADDSPD ||
2174                 type == AUDIT_MAC_IPSEC_DELSPD) && !xp);
2175
2176         audit_buf = audit_log_start(current->audit_context, GFP_ATOMIC, type);
2177         if (audit_buf == NULL)
2178                 return;
2179
2180         switch(type) {
2181         case AUDIT_MAC_IPSEC_ADDSA:
2182                 audit_log_format(audit_buf, "SAD add: auid=%u", auid);
2183                 break;
2184         case AUDIT_MAC_IPSEC_DELSA:
2185                 audit_log_format(audit_buf, "SAD delete: auid=%u", auid);
2186                 break;
2187         case AUDIT_MAC_IPSEC_ADDSPD:
2188                 audit_log_format(audit_buf, "SPD add: auid=%u", auid);
2189                 break;
2190         case AUDIT_MAC_IPSEC_DELSPD:
2191                 audit_log_format(audit_buf, "SPD delete: auid=%u", auid);
2192                 break;
2193         default:
2194                 return;
2195         }
2196
2197         if (sid != 0 &&
2198                 security_secid_to_secctx(sid, &secctx, &secctx_len) == 0)
2199                 audit_log_format(audit_buf, " subj=%s", secctx);
2200         else
2201                 audit_log_task_context(audit_buf);
2202
2203         if (xp) {
2204                 family = xp->selector.family;
2205                 if (xp->security)
2206                         sctx = xp->security;
2207         } else {
2208                 family = x->props.family;
2209                 if (x->security)
2210                         sctx = x->security;
2211         }
2212
2213         if (sctx)
2214                 audit_log_format(audit_buf,
2215                                 " sec_alg=%u sec_doi=%u sec_obj=%s",
2216                                 sctx->ctx_alg, sctx->ctx_doi, sctx->ctx_str);
2217
2218         switch(family) {
2219         case AF_INET:
2220                 {
2221                         struct in_addr saddr, daddr;
2222                         if (xp) {
2223                                 saddr.s_addr = xp->selector.saddr.a4;
2224                                 daddr.s_addr = xp->selector.daddr.a4;
2225                         } else {
2226                                 saddr.s_addr = x->props.saddr.a4;
2227                                 daddr.s_addr = x->id.daddr.a4;
2228                         }
2229                         audit_log_format(audit_buf,
2230                                          " src=%u.%u.%u.%u dst=%u.%u.%u.%u",
2231                                          NIPQUAD(saddr), NIPQUAD(daddr));
2232                 }
2233                         break;
2234         case AF_INET6:
2235                 {
2236                         struct in6_addr saddr6, daddr6;
2237                         if (xp) {
2238                                 memcpy(&saddr6, xp->selector.saddr.a6,
2239                                         sizeof(struct in6_addr));
2240                                 memcpy(&daddr6, xp->selector.daddr.a6,
2241                                         sizeof(struct in6_addr));
2242                         } else {
2243                                 memcpy(&saddr6, x->props.saddr.a6,
2244                                         sizeof(struct in6_addr));
2245                                 memcpy(&daddr6, x->id.daddr.a6,
2246                                         sizeof(struct in6_addr));
2247                         }
2248                         audit_log_format(audit_buf,
2249                                          " src=" NIP6_FMT " dst=" NIP6_FMT,
2250                                          NIP6(saddr6), NIP6(daddr6));
2251                 }
2252                 break;
2253         }
2254
2255         if (x)
2256                 audit_log_format(audit_buf, " spi=%lu(0x%lx) protocol=%s",
2257                                 (unsigned long)ntohl(x->id.spi),
2258                                 (unsigned long)ntohl(x->id.spi),
2259                                 x->id.proto == IPPROTO_AH ? "AH" :
2260                                 (x->id.proto == IPPROTO_ESP ?
2261                                 "ESP" : "IPCOMP"));
2262
2263         audit_log_format(audit_buf, " res=%u", result);
2264         audit_log_end(audit_buf);
2265 }
2266
2267 EXPORT_SYMBOL(xfrm_audit_log);
2268 #endif /* CONFIG_AUDITSYSCALL */
2269
2270 int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
2271 {
2272         int err = 0;
2273         if (unlikely(afinfo == NULL))
2274                 return -EINVAL;
2275         if (unlikely(afinfo->family >= NPROTO))
2276                 return -EAFNOSUPPORT;
2277         write_lock_bh(&xfrm_policy_afinfo_lock);
2278         if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
2279                 err = -ENOBUFS;
2280         else {
2281                 struct dst_ops *dst_ops = afinfo->dst_ops;
2282                 if (likely(dst_ops->kmem_cachep == NULL))
2283                         dst_ops->kmem_cachep = xfrm_dst_cache;
2284                 if (likely(dst_ops->check == NULL))
2285                         dst_ops->check = xfrm_dst_check;
2286                 if (likely(dst_ops->negative_advice == NULL))
2287                         dst_ops->negative_advice = xfrm_negative_advice;
2288                 if (likely(dst_ops->link_failure == NULL))
2289                         dst_ops->link_failure = xfrm_link_failure;
2290                 if (likely(afinfo->garbage_collect == NULL))
2291                         afinfo->garbage_collect = __xfrm_garbage_collect;
2292                 xfrm_policy_afinfo[afinfo->family] = afinfo;
2293         }
2294         write_unlock_bh(&xfrm_policy_afinfo_lock);
2295         return err;
2296 }
2297 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
2298
2299 int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
2300 {
2301         int err = 0;
2302         if (unlikely(afinfo == NULL))
2303                 return -EINVAL;
2304         if (unlikely(afinfo->family >= NPROTO))
2305                 return -EAFNOSUPPORT;
2306         write_lock_bh(&xfrm_policy_afinfo_lock);
2307         if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
2308                 if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
2309                         err = -EINVAL;
2310                 else {
2311                         struct dst_ops *dst_ops = afinfo->dst_ops;
2312                         xfrm_policy_afinfo[afinfo->family] = NULL;
2313                         dst_ops->kmem_cachep = NULL;
2314                         dst_ops->check = NULL;
2315                         dst_ops->negative_advice = NULL;
2316                         dst_ops->link_failure = NULL;
2317                         afinfo->garbage_collect = NULL;
2318                 }
2319         }
2320         write_unlock_bh(&xfrm_policy_afinfo_lock);
2321         return err;
2322 }
2323 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
2324
2325 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
2326 {
2327         struct xfrm_policy_afinfo *afinfo;
2328         if (unlikely(family >= NPROTO))
2329                 return NULL;
2330         read_lock(&xfrm_policy_afinfo_lock);
2331         afinfo = xfrm_policy_afinfo[family];
2332         if (unlikely(!afinfo))
2333                 read_unlock(&xfrm_policy_afinfo_lock);
2334         return afinfo;
2335 }
2336
2337 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
2338 {
2339         read_unlock(&xfrm_policy_afinfo_lock);
2340 }
2341
2342 static struct xfrm_policy_afinfo *xfrm_policy_lock_afinfo(unsigned int family)
2343 {
2344         struct xfrm_policy_afinfo *afinfo;
2345         if (unlikely(family >= NPROTO))
2346                 return NULL;
2347         write_lock_bh(&xfrm_policy_afinfo_lock);
2348         afinfo = xfrm_policy_afinfo[family];
2349         if (unlikely(!afinfo))
2350                 write_unlock_bh(&xfrm_policy_afinfo_lock);
2351         return afinfo;
2352 }
2353
2354 static void xfrm_policy_unlock_afinfo(struct xfrm_policy_afinfo *afinfo)
2355 {
2356         write_unlock_bh(&xfrm_policy_afinfo_lock);
2357 }
2358
2359 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
2360 {
2361         switch (event) {
2362         case NETDEV_DOWN:
2363                 xfrm_flush_bundles();
2364         }
2365         return NOTIFY_DONE;
2366 }
2367
2368 static struct notifier_block xfrm_dev_notifier = {
2369         xfrm_dev_event,
2370         NULL,
2371         0
2372 };
2373
2374 static void __init xfrm_policy_init(void)
2375 {
2376         unsigned int hmask, sz;
2377         int dir;
2378
2379         xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
2380                                            sizeof(struct xfrm_dst),
2381                                            0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
2382                                            NULL);
2383
2384         hmask = 8 - 1;
2385         sz = (hmask+1) * sizeof(struct hlist_head);
2386
2387         xfrm_policy_byidx = xfrm_hash_alloc(sz);
2388         xfrm_idx_hmask = hmask;
2389         if (!xfrm_policy_byidx)
2390                 panic("XFRM: failed to allocate byidx hash\n");
2391
2392         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
2393                 struct xfrm_policy_hash *htab;
2394
2395                 INIT_HLIST_HEAD(&xfrm_policy_inexact[dir]);
2396
2397                 htab = &xfrm_policy_bydst[dir];
2398                 htab->table = xfrm_hash_alloc(sz);
2399                 htab->hmask = hmask;
2400                 if (!htab->table)
2401                         panic("XFRM: failed to allocate bydst hash\n");
2402         }
2403
2404         INIT_WORK(&xfrm_policy_gc_work, xfrm_policy_gc_task);
2405         register_netdevice_notifier(&xfrm_dev_notifier);
2406 }
2407
2408 void __init xfrm_init(void)
2409 {
2410         xfrm_state_init();
2411         xfrm_policy_init();
2412         xfrm_input_init();
2413 }
2414
2415 #ifdef CONFIG_XFRM_MIGRATE
2416 static int xfrm_migrate_selector_match(struct xfrm_selector *sel_cmp,
2417                                        struct xfrm_selector *sel_tgt)
2418 {
2419         if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
2420                 if (sel_tgt->family == sel_cmp->family &&
2421                     xfrm_addr_cmp(&sel_tgt->daddr, &sel_cmp->daddr,
2422                                   sel_cmp->family) == 0 &&
2423                     xfrm_addr_cmp(&sel_tgt->saddr, &sel_cmp->saddr,
2424                                   sel_cmp->family) == 0 &&
2425                     sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
2426                     sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
2427                         return 1;
2428                 }
2429         } else {
2430                 if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
2431                         return 1;
2432                 }
2433         }
2434         return 0;
2435 }
2436
2437 static struct xfrm_policy * xfrm_migrate_policy_find(struct xfrm_selector *sel,
2438                                                      u8 dir, u8 type)
2439 {
2440         struct xfrm_policy *pol, *ret = NULL;
2441         struct hlist_node *entry;
2442         struct hlist_head *chain;
2443         u32 priority = ~0U;
2444
2445         read_lock_bh(&xfrm_policy_lock);
2446         chain = policy_hash_direct(&sel->daddr, &sel->saddr, sel->family, dir);
2447         hlist_for_each_entry(pol, entry, chain, bydst) {
2448                 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
2449                     pol->type == type) {
2450                         ret = pol;
2451                         priority = ret->priority;
2452                         break;
2453                 }
2454         }
2455         chain = &xfrm_policy_inexact[dir];
2456         hlist_for_each_entry(pol, entry, chain, bydst) {
2457                 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
2458                     pol->type == type &&
2459                     pol->priority < priority) {
2460                         ret = pol;
2461                         break;
2462                 }
2463         }
2464
2465         if (ret)
2466                 xfrm_pol_hold(ret);
2467
2468         read_unlock_bh(&xfrm_policy_lock);
2469
2470         return ret;
2471 }
2472
2473 static int migrate_tmpl_match(struct xfrm_migrate *m, struct xfrm_tmpl *t)
2474 {
2475         int match = 0;
2476
2477         if (t->mode == m->mode && t->id.proto == m->proto &&
2478             (m->reqid == 0 || t->reqid == m->reqid)) {
2479                 switch (t->mode) {
2480                 case XFRM_MODE_TUNNEL:
2481                 case XFRM_MODE_BEET:
2482                         if (xfrm_addr_cmp(&t->id.daddr, &m->old_daddr,
2483                                           m->old_family) == 0 &&
2484                             xfrm_addr_cmp(&t->saddr, &m->old_saddr,
2485                                           m->old_family) == 0) {
2486                                 match = 1;
2487                         }
2488                         break;
2489                 case XFRM_MODE_TRANSPORT:
2490                         /* in case of transport mode, template does not store
2491                            any IP addresses, hence we just compare mode and
2492                            protocol */
2493                         match = 1;
2494                         break;
2495                 default:
2496                         break;
2497                 }
2498         }
2499         return match;
2500 }
2501
2502 /* update endpoint address(es) of template(s) */
2503 static int xfrm_policy_migrate(struct xfrm_policy *pol,
2504                                struct xfrm_migrate *m, int num_migrate)
2505 {
2506         struct xfrm_migrate *mp;
2507         struct dst_entry *dst;
2508         int i, j, n = 0;
2509
2510         write_lock_bh(&pol->lock);
2511         if (unlikely(pol->dead)) {
2512                 /* target policy has been deleted */
2513                 write_unlock_bh(&pol->lock);
2514                 return -ENOENT;
2515         }
2516
2517         for (i = 0; i < pol->xfrm_nr; i++) {
2518                 for (j = 0, mp = m; j < num_migrate; j++, mp++) {
2519                         if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
2520                                 continue;
2521                         n++;
2522                         if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL)
2523                                 continue;
2524                         /* update endpoints */
2525                         memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
2526                                sizeof(pol->xfrm_vec[i].id.daddr));
2527                         memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
2528                                sizeof(pol->xfrm_vec[i].saddr));
2529                         pol->xfrm_vec[i].encap_family = mp->new_family;
2530                         /* flush bundles */
2531                         while ((dst = pol->bundles) != NULL) {
2532                                 pol->bundles = dst->next;
2533                                 dst_free(dst);
2534                         }
2535                 }
2536         }
2537
2538         write_unlock_bh(&pol->lock);
2539
2540         if (!n)
2541                 return -ENODATA;
2542
2543         return 0;
2544 }
2545
2546 static int xfrm_migrate_check(struct xfrm_migrate *m, int num_migrate)
2547 {
2548         int i, j;
2549
2550         if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
2551                 return -EINVAL;
2552
2553         for (i = 0; i < num_migrate; i++) {
2554                 if ((xfrm_addr_cmp(&m[i].old_daddr, &m[i].new_daddr,
2555                                    m[i].old_family) == 0) &&
2556                     (xfrm_addr_cmp(&m[i].old_saddr, &m[i].new_saddr,
2557                                    m[i].old_family) == 0))
2558                         return -EINVAL;
2559                 if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
2560                     xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
2561                         return -EINVAL;
2562
2563                 /* check if there is any duplicated entry */
2564                 for (j = i + 1; j < num_migrate; j++) {
2565                         if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
2566                                     sizeof(m[i].old_daddr)) &&
2567                             !memcmp(&m[i].old_saddr, &m[j].old_saddr,
2568                                     sizeof(m[i].old_saddr)) &&
2569                             m[i].proto == m[j].proto &&
2570                             m[i].mode == m[j].mode &&
2571                             m[i].reqid == m[j].reqid &&
2572                             m[i].old_family == m[j].old_family)
2573                                 return -EINVAL;
2574                 }
2575         }
2576
2577         return 0;
2578 }
2579
2580 int xfrm_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
2581                  struct xfrm_migrate *m, int num_migrate)
2582 {
2583         int i, err, nx_cur = 0, nx_new = 0;
2584         struct xfrm_policy *pol = NULL;
2585         struct xfrm_state *x, *xc;
2586         struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
2587         struct xfrm_state *x_new[XFRM_MAX_DEPTH];
2588         struct xfrm_migrate *mp;
2589
2590         if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
2591                 goto out;
2592
2593         /* Stage 1 - find policy */
2594         if ((pol = xfrm_migrate_policy_find(sel, dir, type)) == NULL) {
2595                 err = -ENOENT;
2596                 goto out;
2597         }
2598
2599         /* Stage 2 - find and update state(s) */
2600         for (i = 0, mp = m; i < num_migrate; i++, mp++) {
2601                 if ((x = xfrm_migrate_state_find(mp))) {
2602                         x_cur[nx_cur] = x;
2603                         nx_cur++;
2604                         if ((xc = xfrm_state_migrate(x, mp))) {
2605                                 x_new[nx_new] = xc;
2606                                 nx_new++;
2607                         } else {
2608                                 err = -ENODATA;
2609                                 goto restore_state;
2610                         }
2611                 }
2612         }
2613
2614         /* Stage 3 - update policy */
2615         if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
2616                 goto restore_state;
2617
2618         /* Stage 4 - delete old state(s) */
2619         if (nx_cur) {
2620                 xfrm_states_put(x_cur, nx_cur);
2621                 xfrm_states_delete(x_cur, nx_cur);
2622         }
2623
2624         /* Stage 5 - announce */
2625         km_migrate(sel, dir, type, m, num_migrate);
2626
2627         xfrm_pol_put(pol);
2628
2629         return 0;
2630 out:
2631         return err;
2632
2633 restore_state:
2634         if (pol)
2635                 xfrm_pol_put(pol);
2636         if (nx_cur)
2637                 xfrm_states_put(x_cur, nx_cur);
2638         if (nx_new)
2639                 xfrm_states_delete(x_new, nx_new);
2640
2641         return err;
2642 }
2643 EXPORT_SYMBOL(xfrm_migrate);
2644 #endif