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   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
  29 #include "xfrm_hash.h"
  30
  31 DEFINE_MUTEX(xfrm_cfg_mutex);
  32 EXPORT_SYMBOL(xfrm_cfg_mutex);
  33
  34 static DEFINE_RWLOCK(xfrm_policy_lock);
  35
  36 unsigned int xfrm_policy_count[XFRM_POLICY_MAX*2];
  37 EXPORT_SYMBOL(xfrm_policy_count);
  38
  39 static DEFINE_RWLOCK(xfrm_policy_afinfo_lock);
  40 static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO];
  41
  42 static kmem_cache_t *xfrm_dst_cache __read_mostly;
  43
  44 static struct work_struct xfrm_policy_gc_work;
  45 static HLIST_HEAD(xfrm_policy_gc_list);
  46 static DEFINE_SPINLOCK(xfrm_policy_gc_lock);
  47
  48 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family);
  49 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);
  50 static struct xfrm_policy_afinfo *xfrm_policy_lock_afinfo(unsigned int family);
  51 static void xfrm_policy_unlock_afinfo(struct xfrm_policy_afinfo *afinfo);
  52
  53 int xfrm_register_type(struct xfrm_type *type, unsigned short family)
  54 {
  55         struct xfrm_policy_afinfo *afinfo = xfrm_policy_lock_afinfo(family);
  56         struct xfrm_type **typemap;
  57         int err = 0;
  58
  59         if (unlikely(afinfo == NULL))
  60                 return -EAFNOSUPPORT;
  61         typemap = afinfo->type_map;
  62
  63         if (likely(typemap[type->proto] == NULL))
  64                 typemap[type->proto] = type;
  65         else
  66                 err = -EEXIST;
  67         xfrm_policy_unlock_afinfo(afinfo);
  68         return err;
  69 }
  70 EXPORT_SYMBOL(xfrm_register_type);
  71
  72 int xfrm_unregister_type(struct xfrm_type *type, unsigned short family)
  73 {
  74         struct xfrm_policy_afinfo *afinfo = xfrm_policy_lock_afinfo(family);
  75         struct xfrm_type **typemap;
  76         int err = 0;
  77
  78         if (unlikely(afinfo == NULL))
  79                 return -EAFNOSUPPORT;
  80         typemap = afinfo->type_map;
  81
  82         if (unlikely(typemap[type->proto] != type))
  83                 err = -ENOENT;
  84         else
  85                 typemap[type->proto] = NULL;
  86         xfrm_policy_unlock_afinfo(afinfo);
  87         return err;
  88 }
  89 EXPORT_SYMBOL(xfrm_unregister_type);
  90
  91 struct xfrm_type *xfrm_get_type(u8 proto, unsigned short family)
  92 {
  93         struct xfrm_policy_afinfo *afinfo;
  94         struct xfrm_type **typemap;
  95         struct xfrm_type *type;
  96         int modload_attempted = 0;
  97
  98 retry:
  99         afinfo = xfrm_policy_get_afinfo(family);
 100         if (unlikely(afinfo == NULL))
 101                 return NULL;
 102         typemap = afinfo->type_map;
 103
 104         type = typemap[proto];
 105         if (unlikely(type && !try_module_get(type->owner)))
 106                 type = NULL;
 107         if (!type && !modload_attempted) {
 108                 xfrm_policy_put_afinfo(afinfo);
 109                 request_module("xfrm-type-%d-%d",
 110                                (int) family, (int) proto);
 111                 modload_attempted = 1;
 112                 goto retry;
 113         }
 114
 115         xfrm_policy_put_afinfo(afinfo);
 116         return type;
 117 }
 118
 119 int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl,
 120                     unsigned short family)
 121 {
 122         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
 123         int err = 0;
 124
 125         if (unlikely(afinfo == NULL))
 126                 return -EAFNOSUPPORT;
 127
 128         if (likely(afinfo->dst_lookup != NULL))
 129                 err = afinfo->dst_lookup(dst, fl);
 130         else
 131                 err = -EINVAL;
 132         xfrm_policy_put_afinfo(afinfo);
 133         return err;
 134 }
 135 EXPORT_SYMBOL(xfrm_dst_lookup);
 136
 137 void xfrm_put_type(struct xfrm_type *type)
 138 {
 139         module_put(type->owner);
 140 }
 141
 142 int xfrm_register_mode(struct xfrm_mode *mode, int family)
 143 {
 144         struct xfrm_policy_afinfo *afinfo;
 145         struct xfrm_mode **modemap;
 146         int err;
 147
 148         if (unlikely(mode->encap >= XFRM_MODE_MAX))
 149                 return -EINVAL;
 150
 151         afinfo = xfrm_policy_lock_afinfo(family);
 152         if (unlikely(afinfo == NULL))
 153                 return -EAFNOSUPPORT;
 154
 155         err = -EEXIST;
 156         modemap = afinfo->mode_map;
 157         if (likely(modemap[mode->encap] == NULL)) {
 158                 modemap[mode->encap] = mode;
 159                 err = 0;
 160         }
 161
 162         xfrm_policy_unlock_afinfo(afinfo);
 163         return err;
 164 }
 165 EXPORT_SYMBOL(xfrm_register_mode);
 166
 167 int xfrm_unregister_mode(struct xfrm_mode *mode, int family)
 168 {
 169         struct xfrm_policy_afinfo *afinfo;
 170         struct xfrm_mode **modemap;
 171         int err;
 172
 173         if (unlikely(mode->encap >= XFRM_MODE_MAX))
 174                 return -EINVAL;
 175
 176         afinfo = xfrm_policy_lock_afinfo(family);
 177         if (unlikely(afinfo == NULL))
 178                 return -EAFNOSUPPORT;
 179
 180         err = -ENOENT;
 181         modemap = afinfo->mode_map;
 182         if (likely(modemap[mode->encap] == mode)) {
 183                 modemap[mode->encap] = NULL;
 184                 err = 0;
 185         }
 186
 187         xfrm_policy_unlock_afinfo(afinfo);
 188         return err;
 189 }
 190 EXPORT_SYMBOL(xfrm_unregister_mode);
 191
 192 struct xfrm_mode *xfrm_get_mode(unsigned int encap, int family)
 193 {
 194         struct xfrm_policy_afinfo *afinfo;
 195         struct xfrm_mode *mode;
 196         int modload_attempted = 0;
 197
 198         if (unlikely(encap >= XFRM_MODE_MAX))
 199                 return NULL;
 200
 201 retry:
 202         afinfo = xfrm_policy_get_afinfo(family);
 203         if (unlikely(afinfo == NULL))
 204                 return NULL;
 205
 206         mode = afinfo->mode_map[encap];
 207         if (unlikely(mode && !try_module_get(mode->owner)))
 208                 mode = NULL;
 209         if (!mode && !modload_attempted) {
 210                 xfrm_policy_put_afinfo(afinfo);
 211                 request_module("xfrm-mode-%d-%d", family, encap);
 212                 modload_attempted = 1;
 213                 goto retry;
 214         }
 215
 216         xfrm_policy_put_afinfo(afinfo);
 217         return mode;
 218 }
 219
 220 void xfrm_put_mode(struct xfrm_mode *mode)
 221 {
 222         module_put(mode->owner);
 223 }
 224
 225 static inline unsigned long make_jiffies(long secs)
 226 {
 227         if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
 228                 return MAX_SCHEDULE_TIMEOUT-1;
 229         else
 230                 return secs*HZ;
 231 }
 232
 233 static void xfrm_policy_timer(unsigned long data)
 234 {
 235         struct xfrm_policy *xp = (struct xfrm_policy*)data;
 236         unsigned long now = (unsigned long)xtime.tv_sec;
 237         long next = LONG_MAX;
 238         int warn = 0;
 239         int dir;
 240
 241         read_lock(&xp->lock);
 242
 243         if (xp->dead)
 244                 goto out;
 245
 246         dir = xfrm_policy_id2dir(xp->index);
 247
 248         if (xp->lft.hard_add_expires_seconds) {
 249                 long tmo = xp->lft.hard_add_expires_seconds +
 250                         xp->curlft.add_time - now;
 251                 if (tmo <= 0)
 252                         goto expired;
 253                 if (tmo < next)
 254                         next = tmo;
 255         }
 256         if (xp->lft.hard_use_expires_seconds) {
 257                 long tmo = xp->lft.hard_use_expires_seconds +
 258                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 259                 if (tmo <= 0)
 260                         goto expired;
 261                 if (tmo < next)
 262                         next = tmo;
 263         }
 264         if (xp->lft.soft_add_expires_seconds) {
 265                 long tmo = xp->lft.soft_add_expires_seconds +
 266                         xp->curlft.add_time - now;
 267                 if (tmo <= 0) {
 268                         warn = 1;
 269                         tmo = XFRM_KM_TIMEOUT;
 270                 }
 271                 if (tmo < next)
 272                         next = tmo;
 273         }
 274         if (xp->lft.soft_use_expires_seconds) {
 275                 long tmo = xp->lft.soft_use_expires_seconds +
 276                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 277                 if (tmo <= 0) {
 278                         warn = 1;
 279                         tmo = XFRM_KM_TIMEOUT;
 280                 }
 281                 if (tmo < next)
 282                         next = tmo;
 283         }
 284
 285         if (warn)
 286                 km_policy_expired(xp, dir, 0, 0);
 287         if (next != LONG_MAX &&
 288             !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
 289                 xfrm_pol_hold(xp);
 290
 291 out:
 292         read_unlock(&xp->lock);
 293         xfrm_pol_put(xp);
 294         return;
 295
 296 expired:
 297         read_unlock(&xp->lock);
 298         if (!xfrm_policy_delete(xp, dir))
 299                 km_policy_expired(xp, dir, 1, 0);
 300         xfrm_pol_put(xp);
 301 }
 302
 303
 304 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
 305  * SPD calls.
 306  */
 307
 308 struct xfrm_policy *xfrm_policy_alloc(gfp_t gfp)
 309 {
 310         struct xfrm_policy *policy;
 311
 312         policy = kzalloc(sizeof(struct xfrm_policy), gfp);
 313
 314         if (policy) {
 315                 INIT_HLIST_NODE(&policy->bydst);
 316                 INIT_HLIST_NODE(&policy->byidx);
 317                 rwlock_init(&policy->lock);
 318                 atomic_set(&policy->refcnt, 1);
 319                 init_timer(&policy->timer);
 320                 policy->timer.data = (unsigned long)policy;
 321                 policy->timer.function = xfrm_policy_timer;
 322         }
 323         return policy;
 324 }
 325 EXPORT_SYMBOL(xfrm_policy_alloc);
 326
 327 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
 328
 329 void __xfrm_policy_destroy(struct xfrm_policy *policy)
 330 {
 331         BUG_ON(!policy->dead);
 332
 333         BUG_ON(policy->bundles);
 334
 335         if (del_timer(&policy->timer))
 336                 BUG();
 337
 338         security_xfrm_policy_free(policy);
 339         kfree(policy);
 340 }
 341 EXPORT_SYMBOL(__xfrm_policy_destroy);
 342
 343 static void xfrm_policy_gc_kill(struct xfrm_policy *policy)
 344 {
 345         struct dst_entry *dst;
 346
 347         while ((dst = policy->bundles) != NULL) {
 348                 policy->bundles = dst->next;
 349                 dst_free(dst);
 350         }
 351
 352         if (del_timer(&policy->timer))
 353                 atomic_dec(&policy->refcnt);
 354
 355         if (atomic_read(&policy->refcnt) > 1)
 356                 flow_cache_flush();
 357
 358         xfrm_pol_put(policy);
 359 }
 360
 361 static void xfrm_policy_gc_task(void *data)
 362 {
 363         struct xfrm_policy *policy;
 364         struct hlist_node *entry, *tmp;
 365         struct hlist_head gc_list;
 366
 367         spin_lock_bh(&xfrm_policy_gc_lock);
 368         gc_list.first = xfrm_policy_gc_list.first;
 369         INIT_HLIST_HEAD(&xfrm_policy_gc_list);
 370         spin_unlock_bh(&xfrm_policy_gc_lock);
 371
 372         hlist_for_each_entry_safe(policy, entry, tmp, &gc_list, bydst)
 373                 xfrm_policy_gc_kill(policy);
 374 }
 375
 376 /* Rule must be locked. Release descentant resources, announce
 377  * entry dead. The rule must be unlinked from lists to the moment.
 378  */
 379
 380 static void xfrm_policy_kill(struct xfrm_policy *policy)
 381 {
 382         int dead;
 383
 384         write_lock_bh(&policy->lock);
 385         dead = policy->dead;
 386         policy->dead = 1;
 387         write_unlock_bh(&policy->lock);
 388
 389         if (unlikely(dead)) {
 390                 WARN_ON(1);
 391                 return;
 392         }
 393
 394         spin_lock(&xfrm_policy_gc_lock);
 395         hlist_add_head(&policy->bydst, &xfrm_policy_gc_list);
 396         spin_unlock(&xfrm_policy_gc_lock);
 397
 398         schedule_work(&xfrm_policy_gc_work);
 399 }
 400
 401 struct xfrm_policy_hash {
 402         struct hlist_head       *table;
 403         unsigned int            hmask;
 404 };
 405
 406 static struct hlist_head xfrm_policy_inexact[XFRM_POLICY_MAX*2];
 407 static struct xfrm_policy_hash xfrm_policy_bydst[XFRM_POLICY_MAX*2] __read_mostly;
 408 static struct hlist_head *xfrm_policy_byidx __read_mostly;
 409 static unsigned int xfrm_idx_hmask __read_mostly;
 410 static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
 411
 412 static inline unsigned int idx_hash(u32 index)
 413 {
 414         return __idx_hash(index, xfrm_idx_hmask);
 415 }
 416
 417 static struct hlist_head *policy_hash_bysel(struct xfrm_selector *sel, unsigned short family, int dir)
 418 {
 419         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
 420         unsigned int hash = __sel_hash(sel, family, hmask);
 421
 422         return (hash == hmask + 1 ?
 423                 &xfrm_policy_inexact[dir] :
 424                 xfrm_policy_bydst[dir].table + hash);
 425 }
 426
 427 static struct hlist_head *policy_hash_direct(xfrm_address_t *daddr, xfrm_address_t *saddr, unsigned short family, int dir)
 428 {
 429         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
 430         unsigned int hash = __addr_hash(daddr, saddr, family, hmask);
 431
 432         return xfrm_policy_bydst[dir].table + hash;
 433 }
 434
 435 static void xfrm_dst_hash_transfer(struct hlist_head *list,
 436                                    struct hlist_head *ndsttable,
 437                                    unsigned int nhashmask)
 438 {
 439         struct hlist_node *entry, *tmp;
 440         struct xfrm_policy *pol;
 441
 442         hlist_for_each_entry_safe(pol, entry, tmp, list, bydst) {
 443                 unsigned int h;
 444
 445                 h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
 446                                 pol->family, nhashmask);
 447                 hlist_add_head(&pol->bydst, ndsttable+h);
 448         }
 449 }
 450
 451 static void xfrm_idx_hash_transfer(struct hlist_head *list,
 452                                    struct hlist_head *nidxtable,
 453                                    unsigned int nhashmask)
 454 {
 455         struct hlist_node *entry, *tmp;
 456         struct xfrm_policy *pol;
 457
 458         hlist_for_each_entry_safe(pol, entry, tmp, list, byidx) {
 459                 unsigned int h;
 460
 461                 h = __idx_hash(pol->index, nhashmask);
 462                 hlist_add_head(&pol->byidx, nidxtable+h);
 463         }
 464 }
 465
 466 static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
 467 {
 468         return ((old_hmask + 1) << 1) - 1;
 469 }
 470
 471 static void xfrm_bydst_resize(int dir)
 472 {
 473         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
 474         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 475         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 476         struct hlist_head *odst = xfrm_policy_bydst[dir].table;
 477         struct hlist_head *ndst = xfrm_hash_alloc(nsize);
 478         int i;
 479
 480         if (!ndst)
 481                 return;
 482
 483         write_lock_bh(&xfrm_policy_lock);
 484
 485         for (i = hmask; i >= 0; i--)
 486                 xfrm_dst_hash_transfer(odst + i, ndst, nhashmask);
 487
 488         xfrm_policy_bydst[dir].table = ndst;
 489         xfrm_policy_bydst[dir].hmask = nhashmask;
 490
 491         write_unlock_bh(&xfrm_policy_lock);
 492
 493         xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
 494 }
 495
 496 static void xfrm_byidx_resize(int total)
 497 {
 498         unsigned int hmask = xfrm_idx_hmask;
 499         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 500         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 501         struct hlist_head *oidx = xfrm_policy_byidx;
 502         struct hlist_head *nidx = xfrm_hash_alloc(nsize);
 503         int i;
 504
 505         if (!nidx)
 506                 return;
 507
 508         write_lock_bh(&xfrm_policy_lock);
 509
 510         for (i = hmask; i >= 0; i--)
 511                 xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
 512
 513         xfrm_policy_byidx = nidx;
 514         xfrm_idx_hmask = nhashmask;
 515
 516         write_unlock_bh(&xfrm_policy_lock);
 517
 518         xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
 519 }
 520
 521 static inline int xfrm_bydst_should_resize(int dir, int *total)
 522 {
 523         unsigned int cnt = xfrm_policy_count[dir];
 524         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
 525
 526         if (total)
 527                 *total += cnt;
 528
 529         if ((hmask + 1) < xfrm_policy_hashmax &&
 530             cnt > hmask)
 531                 return 1;
 532
 533         return 0;
 534 }
 535
 536 static inline int xfrm_byidx_should_resize(int total)
 537 {
 538         unsigned int hmask = xfrm_idx_hmask;
 539
 540         if ((hmask + 1) < xfrm_policy_hashmax &&
 541             total > hmask)
 542                 return 1;
 543
 544         return 0;
 545 }
 546
 547 static DEFINE_MUTEX(hash_resize_mutex);
 548
 549 static void xfrm_hash_resize(void *__unused)
 550 {
 551         int dir, total;
 552
 553         mutex_lock(&hash_resize_mutex);
 554
 555         total = 0;
 556         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
 557                 if (xfrm_bydst_should_resize(dir, &total))
 558                         xfrm_bydst_resize(dir);
 559         }
 560         if (xfrm_byidx_should_resize(total))
 561                 xfrm_byidx_resize(total);
 562
 563         mutex_unlock(&hash_resize_mutex);
 564 }
 565
 566 static DECLARE_WORK(xfrm_hash_work, xfrm_hash_resize, NULL);
 567
 568 /* Generate new index... KAME seems to generate them ordered by cost
 569  * of an absolute inpredictability of ordering of rules. This will not pass. */
 570 static u32 xfrm_gen_index(u8 type, int dir)
 571 {
 572         static u32 idx_generator;
 573
 574         for (;;) {
 575                 struct hlist_node *entry;
 576                 struct hlist_head *list;
 577                 struct xfrm_policy *p;
 578                 u32 idx;
 579                 int found;
 580
 581                 idx = (idx_generator | dir);
 582                 idx_generator += 8;
 583                 if (idx == 0)
 584                         idx = 8;
 585                 list = xfrm_policy_byidx + idx_hash(idx);
 586                 found = 0;
 587                 hlist_for_each_entry(p, entry, list, byidx) {
 588                         if (p->index == idx) {
 589                                 found = 1;
 590                                 break;
 591                         }
 592                 }
 593                 if (!found)
 594                         return idx;
 595         }
 596 }
 597
 598 static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
 599 {
 600         u32 *p1 = (u32 *) s1;
 601         u32 *p2 = (u32 *) s2;
 602         int len = sizeof(struct xfrm_selector) / sizeof(u32);
 603         int i;
 604
 605         for (i = 0; i < len; i++) {
 606                 if (p1[i] != p2[i])
 607                         return 1;
 608         }
 609
 610         return 0;
 611 }
 612
 613 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 614 {
 615         struct xfrm_policy *pol;
 616         struct xfrm_policy *delpol;
 617         struct hlist_head *chain;
 618         struct hlist_node *entry, *newpos, *last;
 619         struct dst_entry *gc_list;
 620
 621         write_lock_bh(&xfrm_policy_lock);
 622         chain = policy_hash_bysel(&policy->selector, policy->family, dir);
 623         delpol = NULL;
 624         newpos = NULL;
 625         last = NULL;
 626         hlist_for_each_entry(pol, entry, chain, bydst) {
 627                 if (!delpol &&
 628                     pol->type == policy->type &&
 629                     !selector_cmp(&pol->selector, &policy->selector) &&
 630                     xfrm_sec_ctx_match(pol->security, policy->security)) {
 631                         if (excl) {
 632                                 write_unlock_bh(&xfrm_policy_lock);
 633                                 return -EEXIST;
 634                         }
 635                         delpol = pol;
 636                         if (policy->priority > pol->priority)
 637                                 continue;
 638                 } else if (policy->priority >= pol->priority) {
 639                         last = &pol->bydst;
 640                         continue;
 641                 }
 642                 if (!newpos)
 643                         newpos = &pol->bydst;
 644                 if (delpol)
 645                         break;
 646                 last = &pol->bydst;
 647         }
 648         if (!newpos)
 649                 newpos = last;
 650         if (newpos)
 651                 hlist_add_after(newpos, &policy->bydst);
 652         else
 653                 hlist_add_head(&policy->bydst, chain);
 654         xfrm_pol_hold(policy);
 655         xfrm_policy_count[dir]++;
 656         atomic_inc(&flow_cache_genid);
 657         if (delpol) {
 658                 hlist_del(&delpol->bydst);
 659                 hlist_del(&delpol->byidx);
 660                 xfrm_policy_count[dir]--;
 661         }
 662         policy->index = delpol ? delpol->index : xfrm_gen_index(policy->type, dir);
 663         hlist_add_head(&policy->byidx, xfrm_policy_byidx+idx_hash(policy->index));
 664         policy->curlft.add_time = (unsigned long)xtime.tv_sec;
 665         policy->curlft.use_time = 0;
 666         if (!mod_timer(&policy->timer, jiffies + HZ))
 667                 xfrm_pol_hold(policy);
 668         write_unlock_bh(&xfrm_policy_lock);
 669
 670         if (delpol)
 671                 xfrm_policy_kill(delpol);
 672         else if (xfrm_bydst_should_resize(dir, NULL))
 673                 schedule_work(&xfrm_hash_work);
 674
 675         read_lock_bh(&xfrm_policy_lock);
 676         gc_list = NULL;
 677         entry = &policy->bydst;
 678         hlist_for_each_entry_continue(policy, entry, bydst) {
 679                 struct dst_entry *dst;
 680
 681                 write_lock(&policy->lock);
 682                 dst = policy->bundles;
 683                 if (dst) {
 684                         struct dst_entry *tail = dst;
 685                         while (tail->next)
 686                                 tail = tail->next;
 687                         tail->next = gc_list;
 688                         gc_list = dst;
 689
 690                         policy->bundles = NULL;
 691                 }
 692                 write_unlock(&policy->lock);
 693         }
 694         read_unlock_bh(&xfrm_policy_lock);
 695
 696         while (gc_list) {
 697                 struct dst_entry *dst = gc_list;
 698
 699                 gc_list = dst->next;
 700                 dst_free(dst);
 701         }
 702
 703         return 0;
 704 }
 705 EXPORT_SYMBOL(xfrm_policy_insert);
 706
 707 struct xfrm_policy *xfrm_policy_bysel_ctx(u8 type, int dir,
 708                                           struct xfrm_selector *sel,
 709                                           struct xfrm_sec_ctx *ctx, int delete)
 710 {
 711         struct xfrm_policy *pol, *ret;
 712         struct hlist_head *chain;
 713         struct hlist_node *entry;
 714
 715         write_lock_bh(&xfrm_policy_lock);
 716         chain = policy_hash_bysel(sel, sel->family, dir);
 717         ret = NULL;
 718         hlist_for_each_entry(pol, entry, chain, bydst) {
 719                 if (pol->type == type &&
 720                     !selector_cmp(sel, &pol->selector) &&
 721                     xfrm_sec_ctx_match(ctx, pol->security)) {
 722                         xfrm_pol_hold(pol);
 723                         if (delete) {
 724                                 hlist_del(&pol->bydst);
 725                                 hlist_del(&pol->byidx);
 726                                 xfrm_policy_count[dir]--;
 727                         }
 728                         ret = pol;
 729                         break;
 730                 }
 731         }
 732         write_unlock_bh(&xfrm_policy_lock);
 733
 734         if (ret && delete) {
 735                 atomic_inc(&flow_cache_genid);
 736                 xfrm_policy_kill(ret);
 737         }
 738         return ret;
 739 }
 740 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
 741
 742 struct xfrm_policy *xfrm_policy_byid(u8 type, int dir, u32 id, int delete)
 743 {
 744         struct xfrm_policy *pol, *ret;
 745         struct hlist_head *chain;
 746         struct hlist_node *entry;
 747
 748         write_lock_bh(&xfrm_policy_lock);
 749         chain = xfrm_policy_byidx + idx_hash(id);
 750         ret = NULL;
 751         hlist_for_each_entry(pol, entry, chain, byidx) {
 752                 if (pol->type == type && pol->index == id) {
 753                         xfrm_pol_hold(pol);
 754                         if (delete) {
 755                                 hlist_del(&pol->bydst);
 756                                 hlist_del(&pol->byidx);
 757                                 xfrm_policy_count[dir]--;
 758                         }
 759                         ret = pol;
 760                         break;
 761                 }
 762         }
 763         write_unlock_bh(&xfrm_policy_lock);
 764
 765         if (ret && delete) {
 766                 atomic_inc(&flow_cache_genid);
 767                 xfrm_policy_kill(ret);
 768         }
 769         return ret;
 770 }
 771 EXPORT_SYMBOL(xfrm_policy_byid);
 772
 773 void xfrm_policy_flush(u8 type)
 774 {
 775         int dir;
 776
 777         write_lock_bh(&xfrm_policy_lock);
 778         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 779                 struct xfrm_policy *pol;
 780                 struct hlist_node *entry;
 781                 int i;
 782
 783         again1:
 784                 hlist_for_each_entry(pol, entry,
 785                                      &xfrm_policy_inexact[dir], bydst) {
 786                         if (pol->type != type)
 787                                 continue;
 788                         hlist_del(&pol->bydst);
 789                         hlist_del(&pol->byidx);
 790                         write_unlock_bh(&xfrm_policy_lock);
 791
 792                         xfrm_policy_kill(pol);
 793
 794                         write_lock_bh(&xfrm_policy_lock);
 795                         goto again1;
 796                 }
 797
 798                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
 799         again2:
 800                         hlist_for_each_entry(pol, entry,
 801                                              xfrm_policy_bydst[dir].table + i,
 802                                              bydst) {
 803                                 if (pol->type != type)
 804                                         continue;
 805                                 hlist_del(&pol->bydst);
 806                                 hlist_del(&pol->byidx);
 807                                 write_unlock_bh(&xfrm_policy_lock);
 808
 809                                 xfrm_policy_kill(pol);
 810
 811                                 write_lock_bh(&xfrm_policy_lock);
 812                                 goto again2;
 813                         }
 814                 }
 815
 816                 xfrm_policy_count[dir] = 0;
 817         }
 818         atomic_inc(&flow_cache_genid);
 819         write_unlock_bh(&xfrm_policy_lock);
 820 }
 821 EXPORT_SYMBOL(xfrm_policy_flush);
 822
 823 int xfrm_policy_walk(u8 type, int (*func)(struct xfrm_policy *, int, int, void*),
 824                      void *data)
 825 {
 826         struct xfrm_policy *pol;
 827         struct hlist_node *entry;
 828         int dir, count, error;
 829
 830         read_lock_bh(&xfrm_policy_lock);
 831         count = 0;
 832         for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
 833                 struct hlist_head *table = xfrm_policy_bydst[dir].table;
 834                 int i;
 835
 836                 hlist_for_each_entry(pol, entry,
 837                                      &xfrm_policy_inexact[dir], bydst) {
 838                         if (pol->type == type)
 839                                 count++;
 840                 }
 841                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
 842                         hlist_for_each_entry(pol, entry, table + i, bydst) {
 843                                 if (pol->type == type)
 844                                         count++;
 845                         }
 846                 }
 847         }
 848
 849         if (count == 0) {
 850                 error = -ENOENT;
 851                 goto out;
 852         }
 853
 854         for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
 855                 struct hlist_head *table = xfrm_policy_bydst[dir].table;
 856                 int i;
 857
 858                 hlist_for_each_entry(pol, entry,
 859                                      &xfrm_policy_inexact[dir], bydst) {
 860                         if (pol->type != type)
 861                                 continue;
 862                         error = func(pol, dir % XFRM_POLICY_MAX, --count, data);
 863                         if (error)
 864                                 goto out;
 865                 }
 866                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
 867                         hlist_for_each_entry(pol, entry, table + i, bydst) {
 868                                 if (pol->type != type)
 869                                         continue;
 870                                 error = func(pol, dir % XFRM_POLICY_MAX, --count, data);
 871                                 if (error)
 872                                         goto out;
 873                         }
 874                 }
 875         }
 876         error = 0;
 877 out:
 878         read_unlock_bh(&xfrm_policy_lock);
 879         return error;
 880 }
 881 EXPORT_SYMBOL(xfrm_policy_walk);
 882
 883 /* Find policy to apply to this flow. */
 884
 885 static int xfrm_policy_match(struct xfrm_policy *pol, struct flowi *fl,
 886                              u8 type, u16 family, int dir)
 887 {
 888         struct xfrm_selector *sel = &pol->selector;
 889         int match;
 890
 891         if (pol->family != family ||
 892             pol->type != type)
 893                 return 0;
 894
 895         match = xfrm_selector_match(sel, fl, family);
 896         if (match) {
 897                 if (!security_xfrm_policy_lookup(pol, fl->secid, dir))
 898                         return 1;
 899         }
 900
 901         return 0;
 902 }
 903
 904 static struct xfrm_policy *xfrm_policy_lookup_bytype(u8 type, struct flowi *fl,
 905                                                      u16 family, u8 dir)
 906 {
 907         struct xfrm_policy *pol, *ret;
 908         xfrm_address_t *daddr, *saddr;
 909         struct hlist_node *entry;
 910         struct hlist_head *chain;
 911         u32 priority = ~0U;
 912
 913         daddr = xfrm_flowi_daddr(fl, family);
 914         saddr = xfrm_flowi_saddr(fl, family);
 915         if (unlikely(!daddr || !saddr))
 916                 return NULL;
 917
 918         read_lock_bh(&xfrm_policy_lock);
 919         chain = policy_hash_direct(daddr, saddr, family, dir);
 920         ret = NULL;
 921         hlist_for_each_entry(pol, entry, chain, bydst) {
 922                 if (xfrm_policy_match(pol, fl, type, family, dir)) {
 923                         ret = pol;
 924                         priority = ret->priority;
 925                         break;
 926                 }
 927         }
 928         chain = &xfrm_policy_inexact[dir];
 929         hlist_for_each_entry(pol, entry, chain, bydst) {
 930                 if (xfrm_policy_match(pol, fl, type, family, dir) &&
 931                     pol->priority < priority) {
 932                         ret = pol;
 933                         break;
 934                 }
 935         }
 936         if (ret)
 937                 xfrm_pol_hold(ret);
 938         read_unlock_bh(&xfrm_policy_lock);
 939
 940         return ret;
 941 }
 942
 943 static void xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
 944                                void **objp, atomic_t **obj_refp)
 945 {
 946         struct xfrm_policy *pol;
 947
 948 #ifdef CONFIG_XFRM_SUB_POLICY
 949         pol = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_SUB, fl, family, dir);
 950         if (pol)
 951                 goto end;
 952 #endif
 953         pol = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN, fl, family, dir);
 954
 955 #ifdef CONFIG_XFRM_SUB_POLICY
 956 end:
 957 #endif
 958         if ((*objp = (void *) pol) != NULL)
 959                 *obj_refp = &pol->refcnt;
 960 }
 961
 962 static inline int policy_to_flow_dir(int dir)
 963 {
 964         if (XFRM_POLICY_IN == FLOW_DIR_IN &&
 965             XFRM_POLICY_OUT == FLOW_DIR_OUT &&
 966             XFRM_POLICY_FWD == FLOW_DIR_FWD)
 967                 return dir;
 968         switch (dir) {
 969         default:
 970         case XFRM_POLICY_IN:
 971                 return FLOW_DIR_IN;
 972         case XFRM_POLICY_OUT:
 973                 return FLOW_DIR_OUT;
 974         case XFRM_POLICY_FWD:
 975                 return FLOW_DIR_FWD;
 976         };
 977 }
 978
 979 static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl)
 980 {
 981         struct xfrm_policy *pol;
 982
 983         read_lock_bh(&xfrm_policy_lock);
 984         if ((pol = sk->sk_policy[dir]) != NULL) {
 985                 int match = xfrm_selector_match(&pol->selector, fl,
 986                                                 sk->sk_family);
 987                 int err = 0;
 988
 989                 if (match)
 990                   err = security_xfrm_policy_lookup(pol, fl->secid, policy_to_flow_dir(dir));
 991
 992                 if (match && !err)
 993                         xfrm_pol_hold(pol);
 994                 else
 995                         pol = NULL;
 996         }
 997         read_unlock_bh(&xfrm_policy_lock);
 998         return pol;
 999 }
1000
1001 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
1002 {
1003         struct hlist_head *chain = policy_hash_bysel(&pol->selector,
1004                                                      pol->family, dir);
1005
1006         hlist_add_head(&pol->bydst, chain);
1007         hlist_add_head(&pol->byidx, xfrm_policy_byidx+idx_hash(pol->index));
1008         xfrm_policy_count[dir]++;
1009         xfrm_pol_hold(pol);
1010
1011         if (xfrm_bydst_should_resize(dir, NULL))
1012                 schedule_work(&xfrm_hash_work);
1013 }
1014
1015 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
1016                                                 int dir)
1017 {
1018         if (hlist_unhashed(&pol->bydst))
1019                 return NULL;
1020
1021         hlist_del(&pol->bydst);
1022         hlist_del(&pol->byidx);
1023         xfrm_policy_count[dir]--;
1024
1025         return pol;
1026 }
1027
1028 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
1029 {
1030         write_lock_bh(&xfrm_policy_lock);
1031         pol = __xfrm_policy_unlink(pol, dir);
1032         write_unlock_bh(&xfrm_policy_lock);
1033         if (pol) {
1034                 if (dir < XFRM_POLICY_MAX)
1035                         atomic_inc(&flow_cache_genid);
1036                 xfrm_policy_kill(pol);
1037                 return 0;
1038         }
1039         return -ENOENT;
1040 }
1041 EXPORT_SYMBOL(xfrm_policy_delete);
1042
1043 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
1044 {
1045         struct xfrm_policy *old_pol;
1046
1047 #ifdef CONFIG_XFRM_SUB_POLICY
1048         if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
1049                 return -EINVAL;
1050 #endif
1051
1052         write_lock_bh(&xfrm_policy_lock);
1053         old_pol = sk->sk_policy[dir];
1054         sk->sk_policy[dir] = pol;
1055         if (pol) {
1056                 pol->curlft.add_time = (unsigned long)xtime.tv_sec;
1057                 pol->index = xfrm_gen_index(pol->type, XFRM_POLICY_MAX+dir);
1058                 __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
1059         }
1060         if (old_pol)
1061                 __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
1062         write_unlock_bh(&xfrm_policy_lock);
1063
1064         if (old_pol) {
1065                 xfrm_policy_kill(old_pol);
1066         }
1067         return 0;
1068 }
1069
1070 static struct xfrm_policy *clone_policy(struct xfrm_policy *old, int dir)
1071 {
1072         struct xfrm_policy *newp = xfrm_policy_alloc(GFP_ATOMIC);
1073
1074         if (newp) {
1075                 newp->selector = old->selector;
1076                 if (security_xfrm_policy_clone(old, newp)) {
1077                         kfree(newp);
1078                         return NULL;  /* ENOMEM */
1079                 }
1080                 newp->lft = old->lft;
1081                 newp->curlft = old->curlft;
1082                 newp->action = old->action;
1083                 newp->flags = old->flags;
1084                 newp->xfrm_nr = old->xfrm_nr;
1085                 newp->index = old->index;
1086                 newp->type = old->type;
1087                 memcpy(newp->xfrm_vec, old->xfrm_vec,
1088                        newp->xfrm_nr*sizeof(struct xfrm_tmpl));
1089                 write_lock_bh(&xfrm_policy_lock);
1090                 __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir);
1091                 write_unlock_bh(&xfrm_policy_lock);
1092                 xfrm_pol_put(newp);
1093         }
1094         return newp;
1095 }
1096
1097 int __xfrm_sk_clone_policy(struct sock *sk)
1098 {
1099         struct xfrm_policy *p0 = sk->sk_policy[0],
1100                            *p1 = sk->sk_policy[1];
1101
1102         sk->sk_policy[0] = sk->sk_policy[1] = NULL;
1103         if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL)
1104                 return -ENOMEM;
1105         if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL)
1106                 return -ENOMEM;
1107         return 0;
1108 }
1109
1110 static int
1111 xfrm_get_saddr(xfrm_address_t *local, xfrm_address_t *remote,
1112                unsigned short family)
1113 {
1114         int err;
1115         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1116
1117         if (unlikely(afinfo == NULL))
1118                 return -EINVAL;
1119         err = afinfo->get_saddr(local, remote);
1120         xfrm_policy_put_afinfo(afinfo);
1121         return err;
1122 }
1123
1124 /* Resolve list of templates for the flow, given policy. */
1125
1126 static int
1127 xfrm_tmpl_resolve_one(struct xfrm_policy *policy, struct flowi *fl,
1128                       struct xfrm_state **xfrm,
1129                       unsigned short family)
1130 {
1131         int nx;
1132         int i, error;
1133         xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
1134         xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
1135         xfrm_address_t tmp;
1136
1137         for (nx=0, i = 0; i < policy->xfrm_nr; i++) {
1138                 struct xfrm_state *x;
1139                 xfrm_address_t *remote = daddr;
1140                 xfrm_address_t *local  = saddr;
1141                 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
1142
1143                 if (tmpl->mode == XFRM_MODE_TUNNEL) {
1144                         remote = &tmpl->id.daddr;
1145                         local = &tmpl->saddr;
1146                         if (xfrm_addr_any(local, family)) {
1147                                 error = xfrm_get_saddr(&tmp, remote, family);
1148                                 if (error)
1149                                         goto fail;
1150                                 local = &tmp;
1151                         }
1152                 }
1153
1154                 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
1155
1156                 if (x && x->km.state == XFRM_STATE_VALID) {
1157                         xfrm[nx++] = x;
1158                         daddr = remote;
1159                         saddr = local;
1160                         continue;
1161                 }
1162                 if (x) {
1163                         error = (x->km.state == XFRM_STATE_ERROR ?
1164                                  -EINVAL : -EAGAIN);
1165                         xfrm_state_put(x);
1166                 }
1167
1168                 if (!tmpl->optional)
1169                         goto fail;
1170         }
1171         return nx;
1172
1173 fail:
1174         for (nx--; nx>=0; nx--)
1175                 xfrm_state_put(xfrm[nx]);
1176         return error;
1177 }
1178
1179 static int
1180 xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, struct flowi *fl,
1181                   struct xfrm_state **xfrm,
1182                   unsigned short family)
1183 {
1184         struct xfrm_state *tp[XFRM_MAX_DEPTH];
1185         struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
1186         int cnx = 0;
1187         int error;
1188         int ret;
1189         int i;
1190
1191         for (i = 0; i < npols; i++) {
1192                 if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
1193                         error = -ENOBUFS;
1194                         goto fail;
1195                 }
1196
1197                 ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
1198                 if (ret < 0) {
1199                         error = ret;
1200                         goto fail;
1201                 } else
1202                         cnx += ret;
1203         }
1204
1205         /* found states are sorted for outbound processing */
1206         if (npols > 1)
1207                 xfrm_state_sort(xfrm, tpp, cnx, family);
1208
1209         return cnx;
1210
1211  fail:
1212         for (cnx--; cnx>=0; cnx--)
1213                 xfrm_state_put(tpp[cnx]);
1214         return error;
1215
1216 }
1217
1218 /* Check that the bundle accepts the flow and its components are
1219  * still valid.
1220  */
1221
1222 static struct dst_entry *
1223 xfrm_find_bundle(struct flowi *fl, struct xfrm_policy *policy, unsigned short family)
1224 {
1225         struct dst_entry *x;
1226         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1227         if (unlikely(afinfo == NULL))
1228                 return ERR_PTR(-EINVAL);
1229         x = afinfo->find_bundle(fl, policy);
1230         xfrm_policy_put_afinfo(afinfo);
1231         return x;
1232 }
1233
1234 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
1235  * all the metrics... Shortly, bundle a bundle.
1236  */
1237
1238 static int
1239 xfrm_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
1240                    struct flowi *fl, struct dst_entry **dst_p,
1241                    unsigned short family)
1242 {
1243         int err;
1244         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1245         if (unlikely(afinfo == NULL))
1246                 return -EINVAL;
1247         err = afinfo->bundle_create(policy, xfrm, nx, fl, dst_p);
1248         xfrm_policy_put_afinfo(afinfo);
1249         return err;
1250 }
1251
1252
1253 static int stale_bundle(struct dst_entry *dst);
1254
1255 /* Main function: finds/creates a bundle for given flow.
1256  *
1257  * At the moment we eat a raw IP route. Mostly to speed up lookups
1258  * on interfaces with disabled IPsec.
1259  */
1260 int xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
1261                 struct sock *sk, int flags)
1262 {
1263         struct xfrm_policy *policy;
1264         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1265         int npols;
1266         int pol_dead;
1267         int xfrm_nr;
1268         int pi;
1269         struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
1270         struct dst_entry *dst, *dst_orig = *dst_p;
1271         int nx = 0;
1272         int err;
1273         u32 genid;
1274         u16 family;
1275         u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
1276
1277 restart:
1278         genid = atomic_read(&flow_cache_genid);
1279         policy = NULL;
1280         for (pi = 0; pi < ARRAY_SIZE(pols); pi++)
1281                 pols[pi] = NULL;
1282         npols = 0;
1283         pol_dead = 0;
1284         xfrm_nr = 0;
1285
1286         if (sk && sk->sk_policy[1])
1287                 policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
1288
1289         if (!policy) {
1290                 /* To accelerate a bit...  */
1291                 if ((dst_orig->flags & DST_NOXFRM) ||
1292                     !xfrm_policy_count[XFRM_POLICY_OUT])
1293                         return 0;
1294
1295                 policy = flow_cache_lookup(fl, dst_orig->ops->family,
1296                                            dir, xfrm_policy_lookup);
1297         }
1298
1299         if (!policy)
1300                 return 0;
1301
1302         family = dst_orig->ops->family;
1303         policy->curlft.use_time = (unsigned long)xtime.tv_sec;
1304         pols[0] = policy;
1305         npols ++;
1306         xfrm_nr += pols[0]->xfrm_nr;
1307
1308         switch (policy->action) {
1309         case XFRM_POLICY_BLOCK:
1310                 /* Prohibit the flow */
1311                 err = -EPERM;
1312                 goto error;
1313
1314         case XFRM_POLICY_ALLOW:
1315 #ifndef CONFIG_XFRM_SUB_POLICY
1316                 if (policy->xfrm_nr == 0) {
1317                         /* Flow passes not transformed. */
1318                         xfrm_pol_put(policy);
1319                         return 0;
1320                 }
1321 #endif
1322
1323                 /* Try to find matching bundle.
1324                  *
1325                  * LATER: help from flow cache. It is optional, this
1326                  * is required only for output policy.
1327                  */
1328                 dst = xfrm_find_bundle(fl, policy, family);
1329                 if (IS_ERR(dst)) {
1330                         err = PTR_ERR(dst);
1331                         goto error;
1332                 }
1333
1334                 if (dst)
1335                         break;
1336
1337 #ifdef CONFIG_XFRM_SUB_POLICY
1338                 if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1339                         pols[1] = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN,
1340                                                             fl, family,
1341                                                             XFRM_POLICY_OUT);
1342                         if (pols[1]) {
1343                                 if (pols[1]->action == XFRM_POLICY_BLOCK) {
1344                                         err = -EPERM;
1345                                         goto error;
1346                                 }
1347                                 npols ++;
1348                                 xfrm_nr += pols[1]->xfrm_nr;
1349                         }
1350                 }
1351
1352                 /*
1353                  * Because neither flowi nor bundle information knows about
1354                  * transformation template size. On more than one policy usage
1355                  * we can realize whether all of them is bypass or not after
1356                  * they are searched. See above not-transformed bypass
1357                  * is surrounded by non-sub policy configuration, too.
1358                  */
1359                 if (xfrm_nr == 0) {
1360                         /* Flow passes not transformed. */
1361                         xfrm_pols_put(pols, npols);
1362                         return 0;
1363                 }
1364
1365 #endif
1366                 nx = xfrm_tmpl_resolve(pols, npols, fl, xfrm, family);
1367
1368                 if (unlikely(nx<0)) {
1369                         err = nx;
1370                         if (err == -EAGAIN && flags) {
1371                                 DECLARE_WAITQUEUE(wait, current);
1372
1373                                 add_wait_queue(&km_waitq, &wait);
1374                                 set_current_state(TASK_INTERRUPTIBLE);
1375                                 schedule();
1376                                 set_current_state(TASK_RUNNING);
1377                                 remove_wait_queue(&km_waitq, &wait);
1378
1379                                 nx = xfrm_tmpl_resolve(pols, npols, fl, xfrm, family);
1380
1381                                 if (nx == -EAGAIN && signal_pending(current)) {
1382                                         err = -ERESTART;
1383                                         goto error;
1384                                 }
1385                                 if (nx == -EAGAIN ||
1386                                     genid != atomic_read(&flow_cache_genid)) {
1387                                         xfrm_pols_put(pols, npols);
1388                                         goto restart;
1389                                 }
1390                                 err = nx;
1391                         }
1392                         if (err < 0)
1393                                 goto error;
1394                 }
1395                 if (nx == 0) {
1396                         /* Flow passes not transformed. */
1397                         xfrm_pols_put(pols, npols);
1398                         return 0;
1399                 }
1400
1401                 dst = dst_orig;
1402                 err = xfrm_bundle_create(policy, xfrm, nx, fl, &dst, family);
1403
1404                 if (unlikely(err)) {
1405                         int i;
1406                         for (i=0; i<nx; i++)
1407                                 xfrm_state_put(xfrm[i]);
1408                         goto error;
1409                 }
1410
1411                 for (pi = 0; pi < npols; pi++) {
1412                         read_lock_bh(&pols[pi]->lock);
1413                         pol_dead |= pols[pi]->dead;
1414                         read_unlock_bh(&pols[pi]->lock);
1415                 }
1416
1417                 write_lock_bh(&policy->lock);
1418                 if (unlikely(pol_dead || stale_bundle(dst))) {
1419                         /* Wow! While we worked on resolving, this
1420                          * policy has gone. Retry. It is not paranoia,
1421                          * we just cannot enlist new bundle to dead object.
1422                          * We can't enlist stable bundles either.
1423                          */
1424                         write_unlock_bh(&policy->lock);
1425                         if (dst)
1426                                 dst_free(dst);
1427
1428                         err = -EHOSTUNREACH;
1429                         goto error;
1430                 }
1431                 dst->next = policy->bundles;
1432                 policy->bundles = dst;
1433                 dst_hold(dst);
1434                 write_unlock_bh(&policy->lock);
1435         }
1436         *dst_p = dst;
1437         dst_release(dst_orig);
1438         xfrm_pols_put(pols, npols);
1439         return 0;
1440
1441 error:
1442         dst_release(dst_orig);
1443         xfrm_pols_put(pols, npols);
1444         *dst_p = NULL;
1445         return err;
1446 }
1447 EXPORT_SYMBOL(xfrm_lookup);
1448
1449 static inline int
1450 xfrm_secpath_reject(int idx, struct sk_buff *skb, struct flowi *fl)
1451 {
1452         struct xfrm_state *x;
1453         int err;
1454
1455         if (!skb->sp || idx < 0 || idx >= skb->sp->len)
1456                 return 0;
1457         x = skb->sp->xvec[idx];
1458         if (!x->type->reject)
1459                 return 0;
1460         xfrm_state_hold(x);
1461         err = x->type->reject(x, skb, fl);
1462         xfrm_state_put(x);
1463         return err;
1464 }
1465
1466 /* When skb is transformed back to its "native" form, we have to
1467  * check policy restrictions. At the moment we make this in maximally
1468  * stupid way. Shame on me. :-) Of course, connected sockets must
1469  * have policy cached at them.
1470  */
1471
1472 static inline int
1473 xfrm_state_ok(struct xfrm_tmpl *tmpl, struct xfrm_state *x,
1474               unsigned short family)
1475 {
1476         if (xfrm_state_kern(x))
1477                 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, family);
1478         return  x->id.proto == tmpl->id.proto &&
1479                 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
1480                 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
1481                 x->props.mode == tmpl->mode &&
1482                 ((tmpl->aalgos & (1<<x->props.aalgo)) ||
1483                  !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
1484                 !(x->props.mode != XFRM_MODE_TRANSPORT &&
1485                   xfrm_state_addr_cmp(tmpl, x, family));
1486 }
1487
1488 /*
1489  * 0 or more than 0 is returned when validation is succeeded (either bypass
1490  * because of optional transport mode, or next index of the mathced secpath
1491  * state with the template.
1492  * -1 is returned when no matching template is found.
1493  * Otherwise "-2 - errored_index" is returned.
1494  */
1495 static inline int
1496 xfrm_policy_ok(struct xfrm_tmpl *tmpl, struct sec_path *sp, int start,
1497                unsigned short family)
1498 {
1499         int idx = start;
1500
1501         if (tmpl->optional) {
1502                 if (tmpl->mode == XFRM_MODE_TRANSPORT)
1503                         return start;
1504         } else
1505                 start = -1;
1506         for (; idx < sp->len; idx++) {
1507                 if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
1508                         return ++idx;
1509                 if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
1510                         if (start == -1)
1511                                 start = -2-idx;
1512                         break;
1513                 }
1514         }
1515         return start;
1516 }
1517
1518 int
1519 xfrm_decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family)
1520 {
1521         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1522         int err;
1523
1524         if (unlikely(afinfo == NULL))
1525                 return -EAFNOSUPPORT;
1526
1527         afinfo->decode_session(skb, fl);
1528         err = security_xfrm_decode_session(skb, &fl->secid);
1529         xfrm_policy_put_afinfo(afinfo);
1530         return err;
1531 }
1532 EXPORT_SYMBOL(xfrm_decode_session);
1533
1534 static inline int secpath_has_nontransport(struct sec_path *sp, int k, int *idxp)
1535 {
1536         for (; k < sp->len; k++) {
1537                 if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
1538                         *idxp = k;
1539                         return 1;
1540                 }
1541         }
1542
1543         return 0;
1544 }
1545
1546 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
1547                         unsigned short family)
1548 {
1549         struct xfrm_policy *pol;
1550         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1551         int npols = 0;
1552         int xfrm_nr;
1553         int pi;
1554         struct flowi fl;
1555         u8 fl_dir = policy_to_flow_dir(dir);
1556         int xerr_idx = -1;
1557
1558         if (xfrm_decode_session(skb, &fl, family) < 0)
1559                 return 0;
1560         nf_nat_decode_session(skb, &fl, family);
1561
1562         /* First, check used SA against their selectors. */
1563         if (skb->sp) {
1564                 int i;
1565
1566                 for (i=skb->sp->len-1; i>=0; i--) {
1567                         struct xfrm_state *x = skb->sp->xvec[i];
1568                         if (!xfrm_selector_match(&x->sel, &fl, family))
1569                                 return 0;
1570                 }
1571         }
1572
1573         pol = NULL;
1574         if (sk && sk->sk_policy[dir])
1575                 pol = xfrm_sk_policy_lookup(sk, dir, &fl);
1576
1577         if (!pol)
1578                 pol = flow_cache_lookup(&fl, family, fl_dir,
1579                                         xfrm_policy_lookup);
1580
1581         if (!pol) {
1582                 if (skb->sp && secpath_has_nontransport(skb->sp, 0, &xerr_idx)) {
1583                         xfrm_secpath_reject(xerr_idx, skb, &fl);
1584                         return 0;
1585                 }
1586                 return 1;
1587         }
1588
1589         pol->curlft.use_time = (unsigned long)xtime.tv_sec;
1590
1591         pols[0] = pol;
1592         npols ++;
1593 #ifdef CONFIG_XFRM_SUB_POLICY
1594         if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1595                 pols[1] = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN,
1596                                                     &fl, family,
1597                                                     XFRM_POLICY_IN);
1598                 if (pols[1]) {
1599                         pols[1]->curlft.use_time = (unsigned long)xtime.tv_sec;
1600                         npols ++;
1601                 }
1602         }
1603 #endif
1604
1605         if (pol->action == XFRM_POLICY_ALLOW) {
1606                 struct sec_path *sp;
1607                 static struct sec_path dummy;
1608                 struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
1609                 struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
1610                 struct xfrm_tmpl **tpp = tp;
1611                 int ti = 0;
1612                 int i, k;
1613
1614                 if ((sp = skb->sp) == NULL)
1615                         sp = &dummy;
1616
1617                 for (pi = 0; pi < npols; pi++) {
1618                         if (pols[pi] != pol &&
1619                             pols[pi]->action != XFRM_POLICY_ALLOW)
1620                                 goto reject;
1621                         if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH)
1622                                 goto reject_error;
1623                         for (i = 0; i < pols[pi]->xfrm_nr; i++)
1624                                 tpp[ti++] = &pols[pi]->xfrm_vec[i];
1625                 }
1626                 xfrm_nr = ti;
1627                 if (npols > 1) {
1628                         xfrm_tmpl_sort(stp, tpp, xfrm_nr, family);
1629                         tpp = stp;
1630                 }
1631
1632                 /* For each tunnel xfrm, find the first matching tmpl.
1633                  * For each tmpl before that, find corresponding xfrm.
1634                  * Order is _important_. Later we will implement
1635                  * some barriers, but at the moment barriers
1636                  * are implied between each two transformations.
1637                  */
1638                 for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
1639                         k = xfrm_policy_ok(tpp[i], sp, k, family);
1640                         if (k < 0) {
1641                                 if (k < -1)
1642                                         /* "-2 - errored_index" returned */
1643                                         xerr_idx = -(2+k);
1644                                 goto reject;
1645                         }
1646                 }
1647
1648                 if (secpath_has_nontransport(sp, k, &xerr_idx))
1649                         goto reject;
1650
1651                 xfrm_pols_put(pols, npols);
1652                 return 1;
1653         }
1654
1655 reject:
1656         xfrm_secpath_reject(xerr_idx, skb, &fl);
1657 reject_error:
1658         xfrm_pols_put(pols, npols);
1659         return 0;
1660 }
1661 EXPORT_SYMBOL(__xfrm_policy_check);
1662
1663 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
1664 {
1665         struct flowi fl;
1666
1667         if (xfrm_decode_session(skb, &fl, family) < 0)
1668                 return 0;
1669
1670         return xfrm_lookup(&skb->dst, &fl, NULL, 0) == 0;
1671 }
1672 EXPORT_SYMBOL(__xfrm_route_forward);
1673
1674 /* Optimize later using cookies and generation ids. */
1675
1676 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
1677 {
1678         /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
1679          * to "-1" to force all XFRM destinations to get validated by
1680          * dst_ops->check on every use.  We do this because when a
1681          * normal route referenced by an XFRM dst is obsoleted we do
1682          * not go looking around for all parent referencing XFRM dsts
1683          * so that we can invalidate them.  It is just too much work.
1684          * Instead we make the checks here on every use.  For example:
1685          *
1686          *      XFRM dst A --> IPv4 dst X
1687          *
1688          * X is the "xdst->route" of A (X is also the "dst->path" of A
1689          * in this example).  If X is marked obsolete, "A" will not
1690          * notice.  That's what we are validating here via the
1691          * stale_bundle() check.
1692          *
1693          * When a policy's bundle is pruned, we dst_free() the XFRM
1694          * dst which causes it's ->obsolete field to be set to a
1695          * positive non-zero integer.  If an XFRM dst has been pruned
1696          * like this, we want to force a new route lookup.
1697          */
1698         if (dst->obsolete < 0 && !stale_bundle(dst))
1699                 return dst;
1700
1701         return NULL;
1702 }
1703
1704 static int stale_bundle(struct dst_entry *dst)
1705 {
1706         return !xfrm_bundle_ok((struct xfrm_dst *)dst, NULL, AF_UNSPEC, 0);
1707 }
1708
1709 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
1710 {
1711         while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
1712                 dst->dev = &loopback_dev;
1713                 dev_hold(&loopback_dev);
1714                 dev_put(dev);
1715         }
1716 }
1717 EXPORT_SYMBOL(xfrm_dst_ifdown);
1718
1719 static void xfrm_link_failure(struct sk_buff *skb)
1720 {
1721         /* Impossible. Such dst must be popped before reaches point of failure. */
1722         return;
1723 }
1724
1725 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
1726 {
1727         if (dst) {
1728                 if (dst->obsolete) {
1729                         dst_release(dst);
1730                         dst = NULL;
1731                 }
1732         }
1733         return dst;
1734 }
1735
1736 static void prune_one_bundle(struct xfrm_policy *pol, int (*func)(struct dst_entry *), struct dst_entry **gc_list_p)
1737 {
1738         struct dst_entry *dst, **dstp;
1739
1740         write_lock(&pol->lock);
1741         dstp = &pol->bundles;
1742         while ((dst=*dstp) != NULL) {
1743                 if (func(dst)) {
1744                         *dstp = dst->next;
1745                         dst->next = *gc_list_p;
1746                         *gc_list_p = dst;
1747                 } else {
1748                         dstp = &dst->next;
1749                 }
1750         }
1751         write_unlock(&pol->lock);
1752 }
1753
1754 static void xfrm_prune_bundles(int (*func)(struct dst_entry *))
1755 {
1756         struct dst_entry *gc_list = NULL;
1757         int dir;
1758
1759         read_lock_bh(&xfrm_policy_lock);
1760         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
1761                 struct xfrm_policy *pol;
1762                 struct hlist_node *entry;
1763                 struct hlist_head *table;
1764                 int i;
1765
1766                 hlist_for_each_entry(pol, entry,
1767                                      &xfrm_policy_inexact[dir], bydst)
1768                         prune_one_bundle(pol, func, &gc_list);
1769
1770                 table = xfrm_policy_bydst[dir].table;
1771                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
1772                         hlist_for_each_entry(pol, entry, table + i, bydst)
1773                                 prune_one_bundle(pol, func, &gc_list);
1774                 }
1775         }
1776         read_unlock_bh(&xfrm_policy_lock);
1777
1778         while (gc_list) {
1779                 struct dst_entry *dst = gc_list;
1780                 gc_list = dst->next;
1781                 dst_free(dst);
1782         }
1783 }
1784
1785 static int unused_bundle(struct dst_entry *dst)
1786 {
1787         return !atomic_read(&dst->__refcnt);
1788 }
1789
1790 static void __xfrm_garbage_collect(void)
1791 {
1792         xfrm_prune_bundles(unused_bundle);
1793 }
1794
1795 static int xfrm_flush_bundles(void)
1796 {
1797         xfrm_prune_bundles(stale_bundle);
1798         return 0;
1799 }
1800
1801 void xfrm_init_pmtu(struct dst_entry *dst)
1802 {
1803         do {
1804                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1805                 u32 pmtu, route_mtu_cached;
1806
1807                 pmtu = dst_mtu(dst->child);
1808                 xdst->child_mtu_cached = pmtu;
1809
1810                 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
1811
1812                 route_mtu_cached = dst_mtu(xdst->route);
1813                 xdst->route_mtu_cached = route_mtu_cached;
1814
1815                 if (pmtu > route_mtu_cached)
1816                         pmtu = route_mtu_cached;
1817
1818                 dst->metrics[RTAX_MTU-1] = pmtu;
1819         } while ((dst = dst->next));
1820 }
1821
1822 EXPORT_SYMBOL(xfrm_init_pmtu);
1823
1824 /* Check that the bundle accepts the flow and its components are
1825  * still valid.
1826  */
1827
1828 int xfrm_bundle_ok(struct xfrm_dst *first, struct flowi *fl, int family, int strict)
1829 {
1830         struct dst_entry *dst = &first->u.dst;
1831         struct xfrm_dst *last;
1832         u32 mtu;
1833
1834         if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) ||
1835             (dst->dev && !netif_running(dst->dev)))
1836                 return 0;
1837
1838         last = NULL;
1839
1840         do {
1841                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1842
1843                 if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family))
1844                         return 0;
1845                 if (fl && !security_xfrm_flow_state_match(fl, dst->xfrm))
1846                         return 0;
1847                 if (dst->xfrm->km.state != XFRM_STATE_VALID)
1848                         return 0;
1849                 if (xdst->genid != dst->xfrm->genid)
1850                         return 0;
1851
1852                 if (strict && fl && dst->xfrm->props.mode != XFRM_MODE_TUNNEL &&
1853                     !xfrm_state_addr_flow_check(dst->xfrm, fl, family))
1854                         return 0;
1855
1856                 mtu = dst_mtu(dst->child);
1857                 if (xdst->child_mtu_cached != mtu) {
1858                         last = xdst;
1859                         xdst->child_mtu_cached = mtu;
1860                 }
1861
1862                 if (!dst_check(xdst->route, xdst->route_cookie))
1863                         return 0;
1864                 mtu = dst_mtu(xdst->route);
1865                 if (xdst->route_mtu_cached != mtu) {
1866                         last = xdst;
1867                         xdst->route_mtu_cached = mtu;
1868                 }
1869
1870                 dst = dst->child;
1871         } while (dst->xfrm);
1872
1873         if (likely(!last))
1874                 return 1;
1875
1876         mtu = last->child_mtu_cached;
1877         for (;;) {
1878                 dst = &last->u.dst;
1879
1880                 mtu = xfrm_state_mtu(dst->xfrm, mtu);
1881                 if (mtu > last->route_mtu_cached)
1882                         mtu = last->route_mtu_cached;
1883                 dst->metrics[RTAX_MTU-1] = mtu;
1884
1885                 if (last == first)
1886                         break;
1887
1888                 last = last->u.next;
1889                 last->child_mtu_cached = mtu;
1890         }
1891
1892         return 1;
1893 }
1894
1895 EXPORT_SYMBOL(xfrm_bundle_ok);
1896
1897 int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
1898 {
1899         int err = 0;
1900         if (unlikely(afinfo == NULL))
1901                 return -EINVAL;
1902         if (unlikely(afinfo->family >= NPROTO))
1903                 return -EAFNOSUPPORT;
1904         write_lock_bh(&xfrm_policy_afinfo_lock);
1905         if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
1906                 err = -ENOBUFS;
1907         else {
1908                 struct dst_ops *dst_ops = afinfo->dst_ops;
1909                 if (likely(dst_ops->kmem_cachep == NULL))
1910                         dst_ops->kmem_cachep = xfrm_dst_cache;
1911                 if (likely(dst_ops->check == NULL))
1912                         dst_ops->check = xfrm_dst_check;
1913                 if (likely(dst_ops->negative_advice == NULL))
1914                         dst_ops->negative_advice = xfrm_negative_advice;
1915                 if (likely(dst_ops->link_failure == NULL))
1916                         dst_ops->link_failure = xfrm_link_failure;
1917                 if (likely(afinfo->garbage_collect == NULL))
1918                         afinfo->garbage_collect = __xfrm_garbage_collect;
1919                 xfrm_policy_afinfo[afinfo->family] = afinfo;
1920         }
1921         write_unlock_bh(&xfrm_policy_afinfo_lock);
1922         return err;
1923 }
1924 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
1925
1926 int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
1927 {
1928         int err = 0;
1929         if (unlikely(afinfo == NULL))
1930                 return -EINVAL;
1931         if (unlikely(afinfo->family >= NPROTO))
1932                 return -EAFNOSUPPORT;
1933         write_lock_bh(&xfrm_policy_afinfo_lock);
1934         if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
1935                 if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
1936                         err = -EINVAL;
1937                 else {
1938                         struct dst_ops *dst_ops = afinfo->dst_ops;
1939                         xfrm_policy_afinfo[afinfo->family] = NULL;
1940                         dst_ops->kmem_cachep = NULL;
1941                         dst_ops->check = NULL;
1942                         dst_ops->negative_advice = NULL;
1943                         dst_ops->link_failure = NULL;
1944                         afinfo->garbage_collect = NULL;
1945                 }
1946         }
1947         write_unlock_bh(&xfrm_policy_afinfo_lock);
1948         return err;
1949 }
1950 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
1951
1952 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
1953 {
1954         struct xfrm_policy_afinfo *afinfo;
1955         if (unlikely(family >= NPROTO))
1956                 return NULL;
1957         read_lock(&xfrm_policy_afinfo_lock);
1958         afinfo = xfrm_policy_afinfo[family];
1959         if (unlikely(!afinfo))
1960                 read_unlock(&xfrm_policy_afinfo_lock);
1961         return afinfo;
1962 }
1963
1964 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
1965 {
1966         read_unlock(&xfrm_policy_afinfo_lock);
1967 }
1968
1969 static struct xfrm_policy_afinfo *xfrm_policy_lock_afinfo(unsigned int family)
1970 {
1971         struct xfrm_policy_afinfo *afinfo;
1972         if (unlikely(family >= NPROTO))
1973                 return NULL;
1974         write_lock_bh(&xfrm_policy_afinfo_lock);
1975         afinfo = xfrm_policy_afinfo[family];
1976         if (unlikely(!afinfo))
1977                 write_unlock_bh(&xfrm_policy_afinfo_lock);
1978         return afinfo;
1979 }
1980
1981 static void xfrm_policy_unlock_afinfo(struct xfrm_policy_afinfo *afinfo)
1982 {
1983         write_unlock_bh(&xfrm_policy_afinfo_lock);
1984 }
1985
1986 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
1987 {
1988         switch (event) {
1989         case NETDEV_DOWN:
1990                 xfrm_flush_bundles();
1991         }
1992         return NOTIFY_DONE;
1993 }
1994
1995 static struct notifier_block xfrm_dev_notifier = {
1996         xfrm_dev_event,
1997         NULL,
1998         0
1999 };
2000
2001 static void __init xfrm_policy_init(void)
2002 {
2003         unsigned int hmask, sz;
2004         int dir;
2005
2006         xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
2007                                            sizeof(struct xfrm_dst),
2008                                            0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
2009                                            NULL, NULL);
2010
2011         hmask = 8 - 1;
2012         sz = (hmask+1) * sizeof(struct hlist_head);
2013
2014         xfrm_policy_byidx = xfrm_hash_alloc(sz);
2015         xfrm_idx_hmask = hmask;
2016         if (!xfrm_policy_byidx)
2017                 panic("XFRM: failed to allocate byidx hash\n");
2018
2019         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
2020                 struct xfrm_policy_hash *htab;
2021
2022                 INIT_HLIST_HEAD(&xfrm_policy_inexact[dir]);
2023
2024                 htab = &xfrm_policy_bydst[dir];
2025                 htab->table = xfrm_hash_alloc(sz);
2026                 htab->hmask = hmask;
2027                 if (!htab->table)
2028                         panic("XFRM: failed to allocate bydst hash\n");
2029         }
2030
2031         INIT_WORK(&xfrm_policy_gc_work, xfrm_policy_gc_task, NULL);
2032         register_netdevice_notifier(&xfrm_dev_notifier);
2033 }
2034
2035 void __init xfrm_init(void)
2036 {
2037         xfrm_state_init();
2038         xfrm_policy_init();
2039         xfrm_input_init();
2040 }
2041