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 <asm/bug.h>
  17 #include <linux/config.h>
  18 #include <linux/slab.h>
  19 #include <linux/kmod.h>
  20 #include <linux/list.h>
  21 #include <linux/spinlock.h>
  22 #include <linux/workqueue.h>
  23 #include <linux/notifier.h>
  24 #include <linux/netdevice.h>
  25 #include <linux/module.h>
  26 #include <net/xfrm.h>
  27 #include <net/ip.h>
  28
  29 DECLARE_MUTEX(xfrm_cfg_sem);
  30 EXPORT_SYMBOL(xfrm_cfg_sem);
  31
  32 static DEFINE_RWLOCK(xfrm_policy_lock);
  33
  34 struct xfrm_policy *xfrm_policy_list[XFRM_POLICY_MAX*2];
  35 EXPORT_SYMBOL(xfrm_policy_list);
  36
  37 static DEFINE_RWLOCK(xfrm_policy_afinfo_lock);
  38 static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO];
  39
  40 static kmem_cache_t *xfrm_dst_cache;
  41
  42 static struct work_struct xfrm_policy_gc_work;
  43 static struct list_head xfrm_policy_gc_list =
  44         LIST_HEAD_INIT(xfrm_policy_gc_list);
  45 static DEFINE_SPINLOCK(xfrm_policy_gc_lock);
  46
  47 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family);
  48 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);
  49
  50 int xfrm_register_type(struct xfrm_type *type, unsigned short family)
  51 {
  52         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
  53         struct xfrm_type_map *typemap;
  54         int err = 0;
  55
  56         if (unlikely(afinfo == NULL))
  57                 return -EAFNOSUPPORT;
  58         typemap = afinfo->type_map;
  59
  60         write_lock(&typemap->lock);
  61         if (likely(typemap->map[type->proto] == NULL))
  62                 typemap->map[type->proto] = type;
  63         else
  64                 err = -EEXIST;
  65         write_unlock(&typemap->lock);
  66         xfrm_policy_put_afinfo(afinfo);
  67         return err;
  68 }
  69 EXPORT_SYMBOL(xfrm_register_type);
  70
  71 int xfrm_unregister_type(struct xfrm_type *type, unsigned short family)
  72 {
  73         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
  74         struct xfrm_type_map *typemap;
  75         int err = 0;
  76
  77         if (unlikely(afinfo == NULL))
  78                 return -EAFNOSUPPORT;
  79         typemap = afinfo->type_map;
  80
  81         write_lock(&typemap->lock);
  82         if (unlikely(typemap->map[type->proto] != type))
  83                 err = -ENOENT;
  84         else
  85                 typemap->map[type->proto] = NULL;
  86         write_unlock(&typemap->lock);
  87         xfrm_policy_put_afinfo(afinfo);
  88         return err;
  89 }
  90 EXPORT_SYMBOL(xfrm_unregister_type);
  91
  92 struct xfrm_type *xfrm_get_type(u8 proto, unsigned short family)
  93 {
  94         struct xfrm_policy_afinfo *afinfo;
  95         struct xfrm_type_map *typemap;
  96         struct xfrm_type *type;
  97         int modload_attempted = 0;
  98
  99 retry:
 100         afinfo = xfrm_policy_get_afinfo(family);
 101         if (unlikely(afinfo == NULL))
 102                 return NULL;
 103         typemap = afinfo->type_map;
 104
 105         read_lock(&typemap->lock);
 106         type = typemap->map[proto];
 107         if (unlikely(type && !try_module_get(type->owner)))
 108                 type = NULL;
 109         read_unlock(&typemap->lock);
 110         if (!type && !modload_attempted) {
 111                 xfrm_policy_put_afinfo(afinfo);
 112                 request_module("xfrm-type-%d-%d",
 113                                (int) family, (int) proto);
 114                 modload_attempted = 1;
 115                 goto retry;
 116         }
 117
 118         xfrm_policy_put_afinfo(afinfo);
 119         return type;
 120 }
 121 EXPORT_SYMBOL(xfrm_get_type);
 122
 123 int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl,
 124                     unsigned short family)
 125 {
 126         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
 127         int err = 0;
 128
 129         if (unlikely(afinfo == NULL))
 130                 return -EAFNOSUPPORT;
 131
 132         if (likely(afinfo->dst_lookup != NULL))
 133                 err = afinfo->dst_lookup(dst, fl);
 134         else
 135                 err = -EINVAL;
 136         xfrm_policy_put_afinfo(afinfo);
 137         return err;
 138 }
 139 EXPORT_SYMBOL(xfrm_dst_lookup);
 140
 141 void xfrm_put_type(struct xfrm_type *type)
 142 {
 143         module_put(type->owner);
 144 }
 145
 146 static inline unsigned long make_jiffies(long secs)
 147 {
 148         if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
 149                 return MAX_SCHEDULE_TIMEOUT-1;
 150         else
 151                 return secs*HZ;
 152 }
 153
 154 static void xfrm_policy_timer(unsigned long data)
 155 {
 156         struct xfrm_policy *xp = (struct xfrm_policy*)data;
 157         unsigned long now = (unsigned long)xtime.tv_sec;
 158         long next = LONG_MAX;
 159         int warn = 0;
 160         int dir;
 161
 162         read_lock(&xp->lock);
 163
 164         if (xp->dead)
 165                 goto out;
 166
 167         dir = xp->index & 7;
 168
 169         if (xp->lft.hard_add_expires_seconds) {
 170                 long tmo = xp->lft.hard_add_expires_seconds +
 171                         xp->curlft.add_time - now;
 172                 if (tmo <= 0)
 173                         goto expired;
 174                 if (tmo < next)
 175                         next = tmo;
 176         }
 177         if (xp->lft.hard_use_expires_seconds) {
 178                 long tmo = xp->lft.hard_use_expires_seconds +
 179                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 180                 if (tmo <= 0)
 181                         goto expired;
 182                 if (tmo < next)
 183                         next = tmo;
 184         }
 185         if (xp->lft.soft_add_expires_seconds) {
 186                 long tmo = xp->lft.soft_add_expires_seconds +
 187                         xp->curlft.add_time - now;
 188                 if (tmo <= 0) {
 189                         warn = 1;
 190                         tmo = XFRM_KM_TIMEOUT;
 191                 }
 192                 if (tmo < next)
 193                         next = tmo;
 194         }
 195         if (xp->lft.soft_use_expires_seconds) {
 196                 long tmo = xp->lft.soft_use_expires_seconds +
 197                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 198                 if (tmo <= 0) {
 199                         warn = 1;
 200                         tmo = XFRM_KM_TIMEOUT;
 201                 }
 202                 if (tmo < next)
 203                         next = tmo;
 204         }
 205
 206         if (warn)
 207                 km_policy_expired(xp, dir, 0);
 208         if (next != LONG_MAX &&
 209             !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
 210                 xfrm_pol_hold(xp);
 211
 212 out:
 213         read_unlock(&xp->lock);
 214         xfrm_pol_put(xp);
 215         return;
 216
 217 expired:
 218         read_unlock(&xp->lock);
 219         km_policy_expired(xp, dir, 1);
 220         xfrm_policy_delete(xp, dir);
 221         xfrm_pol_put(xp);
 222 }
 223
 224
 225 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
 226  * SPD calls.
 227  */
 228
 229 struct xfrm_policy *xfrm_policy_alloc(int gfp)
 230 {
 231         struct xfrm_policy *policy;
 232
 233         policy = kmalloc(sizeof(struct xfrm_policy), gfp);
 234
 235         if (policy) {
 236                 memset(policy, 0, sizeof(struct xfrm_policy));
 237                 atomic_set(&policy->refcnt, 1);
 238                 rwlock_init(&policy->lock);
 239                 init_timer(&policy->timer);
 240                 policy->timer.data = (unsigned long)policy;
 241                 policy->timer.function = xfrm_policy_timer;
 242         }
 243         return policy;
 244 }
 245 EXPORT_SYMBOL(xfrm_policy_alloc);
 246
 247 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
 248
 249 void __xfrm_policy_destroy(struct xfrm_policy *policy)
 250 {
 251         if (!policy->dead)
 252                 BUG();
 253
 254         if (policy->bundles)
 255                 BUG();
 256
 257         if (del_timer(&policy->timer))
 258                 BUG();
 259
 260         kfree(policy);
 261 }
 262 EXPORT_SYMBOL(__xfrm_policy_destroy);
 263
 264 static void xfrm_policy_gc_kill(struct xfrm_policy *policy)
 265 {
 266         struct dst_entry *dst;
 267
 268         while ((dst = policy->bundles) != NULL) {
 269                 policy->bundles = dst->next;
 270                 dst_free(dst);
 271         }
 272
 273         if (del_timer(&policy->timer))
 274                 atomic_dec(&policy->refcnt);
 275
 276         if (atomic_read(&policy->refcnt) > 1)
 277                 flow_cache_flush();
 278
 279         xfrm_pol_put(policy);
 280 }
 281
 282 static void xfrm_policy_gc_task(void *data)
 283 {
 284         struct xfrm_policy *policy;
 285         struct list_head *entry, *tmp;
 286         struct list_head gc_list = LIST_HEAD_INIT(gc_list);
 287
 288         spin_lock_bh(&xfrm_policy_gc_lock);
 289         list_splice_init(&xfrm_policy_gc_list, &gc_list);
 290         spin_unlock_bh(&xfrm_policy_gc_lock);
 291
 292         list_for_each_safe(entry, tmp, &gc_list) {
 293                 policy = list_entry(entry, struct xfrm_policy, list);
 294                 xfrm_policy_gc_kill(policy);
 295         }
 296 }
 297
 298 /* Rule must be locked. Release descentant resources, announce
 299  * entry dead. The rule must be unlinked from lists to the moment.
 300  */
 301
 302 static void xfrm_policy_kill(struct xfrm_policy *policy)
 303 {
 304         int dead;
 305
 306         write_lock_bh(&policy->lock);
 307         dead = policy->dead;
 308         policy->dead = 1;
 309         write_unlock_bh(&policy->lock);
 310
 311         if (unlikely(dead)) {
 312                 WARN_ON(1);
 313                 return;
 314         }
 315
 316         spin_lock(&xfrm_policy_gc_lock);
 317         list_add(&policy->list, &xfrm_policy_gc_list);
 318         spin_unlock(&xfrm_policy_gc_lock);
 319
 320         schedule_work(&xfrm_policy_gc_work);
 321 }
 322
 323 /* Generate new index... KAME seems to generate them ordered by cost
 324  * of an absolute inpredictability of ordering of rules. This will not pass. */
 325 static u32 xfrm_gen_index(int dir)
 326 {
 327         u32 idx;
 328         struct xfrm_policy *p;
 329         static u32 idx_generator;
 330
 331         for (;;) {
 332                 idx = (idx_generator | dir);
 333                 idx_generator += 8;
 334                 if (idx == 0)
 335                         idx = 8;
 336                 for (p = xfrm_policy_list[dir]; p; p = p->next) {
 337                         if (p->index == idx)
 338                                 break;
 339                 }
 340                 if (!p)
 341                         return idx;
 342         }
 343 }
 344
 345 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 346 {
 347         struct xfrm_policy *pol, **p;
 348         struct xfrm_policy *delpol = NULL;
 349         struct xfrm_policy **newpos = NULL;
 350
 351         write_lock_bh(&xfrm_policy_lock);
 352         for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL;) {
 353                 if (!delpol && memcmp(&policy->selector, &pol->selector, sizeof(pol->selector)) == 0) {
 354                         if (excl) {
 355                                 write_unlock_bh(&xfrm_policy_lock);
 356                                 return -EEXIST;
 357                         }
 358                         *p = pol->next;
 359                         delpol = pol;
 360                         if (policy->priority > pol->priority)
 361                                 continue;
 362                 } else if (policy->priority >= pol->priority) {
 363                         p = &pol->next;
 364                         continue;
 365                 }
 366                 if (!newpos)
 367                         newpos = p;
 368                 if (delpol)
 369                         break;
 370                 p = &pol->next;
 371         }
 372         if (newpos)
 373                 p = newpos;
 374         xfrm_pol_hold(policy);
 375         policy->next = *p;
 376         *p = policy;
 377         atomic_inc(&flow_cache_genid);
 378         policy->index = delpol ? delpol->index : xfrm_gen_index(dir);
 379         policy->curlft.add_time = (unsigned long)xtime.tv_sec;
 380         policy->curlft.use_time = 0;
 381         if (!mod_timer(&policy->timer, jiffies + HZ))
 382                 xfrm_pol_hold(policy);
 383         write_unlock_bh(&xfrm_policy_lock);
 384
 385         if (delpol) {
 386                 xfrm_policy_kill(delpol);
 387         }
 388         return 0;
 389 }
 390 EXPORT_SYMBOL(xfrm_policy_insert);
 391
 392 struct xfrm_policy *xfrm_policy_bysel(int dir, struct xfrm_selector *sel,
 393                                       int delete)
 394 {
 395         struct xfrm_policy *pol, **p;
 396
 397         write_lock_bh(&xfrm_policy_lock);
 398         for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL; p = &pol->next) {
 399                 if (memcmp(sel, &pol->selector, sizeof(*sel)) == 0) {
 400                         xfrm_pol_hold(pol);
 401                         if (delete)
 402                                 *p = pol->next;
 403                         break;
 404                 }
 405         }
 406         write_unlock_bh(&xfrm_policy_lock);
 407
 408         if (pol && delete) {
 409                 atomic_inc(&flow_cache_genid);
 410                 xfrm_policy_kill(pol);
 411         }
 412         return pol;
 413 }
 414 EXPORT_SYMBOL(xfrm_policy_bysel);
 415
 416 struct xfrm_policy *xfrm_policy_byid(int dir, u32 id, int delete)
 417 {
 418         struct xfrm_policy *pol, **p;
 419
 420         write_lock_bh(&xfrm_policy_lock);
 421         for (p = &xfrm_policy_list[id & 7]; (pol=*p)!=NULL; p = &pol->next) {
 422                 if (pol->index == id) {
 423                         xfrm_pol_hold(pol);
 424                         if (delete)
 425                                 *p = pol->next;
 426                         break;
 427                 }
 428         }
 429         write_unlock_bh(&xfrm_policy_lock);
 430
 431         if (pol && delete) {
 432                 atomic_inc(&flow_cache_genid);
 433                 xfrm_policy_kill(pol);
 434         }
 435         return pol;
 436 }
 437 EXPORT_SYMBOL(xfrm_policy_byid);
 438
 439 void xfrm_policy_flush(void)
 440 {
 441         struct xfrm_policy *xp;
 442         int dir;
 443
 444         write_lock_bh(&xfrm_policy_lock);
 445         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 446                 while ((xp = xfrm_policy_list[dir]) != NULL) {
 447                         xfrm_policy_list[dir] = xp->next;
 448                         write_unlock_bh(&xfrm_policy_lock);
 449
 450                         xfrm_policy_kill(xp);
 451
 452                         write_lock_bh(&xfrm_policy_lock);
 453                 }
 454         }
 455         atomic_inc(&flow_cache_genid);
 456         write_unlock_bh(&xfrm_policy_lock);
 457 }
 458 EXPORT_SYMBOL(xfrm_policy_flush);
 459
 460 int xfrm_policy_walk(int (*func)(struct xfrm_policy *, int, int, void*),
 461                      void *data)
 462 {
 463         struct xfrm_policy *xp;
 464         int dir;
 465         int count = 0;
 466         int error = 0;
 467
 468         read_lock_bh(&xfrm_policy_lock);
 469         for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
 470                 for (xp = xfrm_policy_list[dir]; xp; xp = xp->next)
 471                         count++;
 472         }
 473
 474         if (count == 0) {
 475                 error = -ENOENT;
 476                 goto out;
 477         }
 478
 479         for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
 480                 for (xp = xfrm_policy_list[dir]; xp; xp = xp->next) {
 481                         error = func(xp, dir%XFRM_POLICY_MAX, --count, data);
 482                         if (error)
 483                                 goto out;
 484                 }
 485         }
 486
 487 out:
 488         read_unlock_bh(&xfrm_policy_lock);
 489         return error;
 490 }
 491 EXPORT_SYMBOL(xfrm_policy_walk);
 492
 493 /* Find policy to apply to this flow. */
 494
 495 static void xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
 496                                void **objp, atomic_t **obj_refp)
 497 {
 498         struct xfrm_policy *pol;
 499
 500         read_lock_bh(&xfrm_policy_lock);
 501         for (pol = xfrm_policy_list[dir]; pol; pol = pol->next) {
 502                 struct xfrm_selector *sel = &pol->selector;
 503                 int match;
 504
 505                 if (pol->family != family)
 506                         continue;
 507
 508                 match = xfrm_selector_match(sel, fl, family);
 509                 if (match) {
 510                         xfrm_pol_hold(pol);
 511                         break;
 512                 }
 513         }
 514         read_unlock_bh(&xfrm_policy_lock);
 515         if ((*objp = (void *) pol) != NULL)
 516                 *obj_refp = &pol->refcnt;
 517 }
 518
 519 static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl)
 520 {
 521         struct xfrm_policy *pol;
 522
 523         read_lock_bh(&xfrm_policy_lock);
 524         if ((pol = sk->sk_policy[dir]) != NULL) {
 525                 int match = xfrm_selector_match(&pol->selector, fl,
 526                                                 sk->sk_family);
 527                 if (match)
 528                         xfrm_pol_hold(pol);
 529                 else
 530                         pol = NULL;
 531         }
 532         read_unlock_bh(&xfrm_policy_lock);
 533         return pol;
 534 }
 535
 536 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
 537 {
 538         pol->next = xfrm_policy_list[dir];
 539         xfrm_policy_list[dir] = pol;
 540         xfrm_pol_hold(pol);
 541 }
 542
 543 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
 544                                                 int dir)
 545 {
 546         struct xfrm_policy **polp;
 547
 548         for (polp = &xfrm_policy_list[dir];
 549              *polp != NULL; polp = &(*polp)->next) {
 550                 if (*polp == pol) {
 551                         *polp = pol->next;
 552                         return pol;
 553                 }
 554         }
 555         return NULL;
 556 }
 557
 558 void xfrm_policy_delete(struct xfrm_policy *pol, int dir)
 559 {
 560         write_lock_bh(&xfrm_policy_lock);
 561         pol = __xfrm_policy_unlink(pol, dir);
 562         write_unlock_bh(&xfrm_policy_lock);
 563         if (pol) {
 564                 if (dir < XFRM_POLICY_MAX)
 565                         atomic_inc(&flow_cache_genid);
 566                 xfrm_policy_kill(pol);
 567         }
 568 }
 569
 570 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
 571 {
 572         struct xfrm_policy *old_pol;
 573
 574         write_lock_bh(&xfrm_policy_lock);
 575         old_pol = sk->sk_policy[dir];
 576         sk->sk_policy[dir] = pol;
 577         if (pol) {
 578                 pol->curlft.add_time = (unsigned long)xtime.tv_sec;
 579                 pol->index = xfrm_gen_index(XFRM_POLICY_MAX+dir);
 580                 __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
 581         }
 582         if (old_pol)
 583                 __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
 584         write_unlock_bh(&xfrm_policy_lock);
 585
 586         if (old_pol) {
 587                 xfrm_policy_kill(old_pol);
 588         }
 589         return 0;
 590 }
 591
 592 static struct xfrm_policy *clone_policy(struct xfrm_policy *old, int dir)
 593 {
 594         struct xfrm_policy *newp = xfrm_policy_alloc(GFP_ATOMIC);
 595
 596         if (newp) {
 597                 newp->selector = old->selector;
 598                 newp->lft = old->lft;
 599                 newp->curlft = old->curlft;
 600                 newp->action = old->action;
 601                 newp->flags = old->flags;
 602                 newp->xfrm_nr = old->xfrm_nr;
 603                 newp->index = old->index;
 604                 memcpy(newp->xfrm_vec, old->xfrm_vec,
 605                        newp->xfrm_nr*sizeof(struct xfrm_tmpl));
 606                 write_lock_bh(&xfrm_policy_lock);
 607                 __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir);
 608                 write_unlock_bh(&xfrm_policy_lock);
 609                 xfrm_pol_put(newp);
 610         }
 611         return newp;
 612 }
 613
 614 int __xfrm_sk_clone_policy(struct sock *sk)
 615 {
 616         struct xfrm_policy *p0 = sk->sk_policy[0],
 617                            *p1 = sk->sk_policy[1];
 618
 619         sk->sk_policy[0] = sk->sk_policy[1] = NULL;
 620         if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL)
 621                 return -ENOMEM;
 622         if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL)
 623                 return -ENOMEM;
 624         return 0;
 625 }
 626
 627 /* Resolve list of templates for the flow, given policy. */
 628
 629 static int
 630 xfrm_tmpl_resolve(struct xfrm_policy *policy, struct flowi *fl,
 631                   struct xfrm_state **xfrm,
 632                   unsigned short family)
 633 {
 634         int nx;
 635         int i, error;
 636         xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
 637         xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
 638
 639         for (nx=0, i = 0; i < policy->xfrm_nr; i++) {
 640                 struct xfrm_state *x;
 641                 xfrm_address_t *remote = daddr;
 642                 xfrm_address_t *local  = saddr;
 643                 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
 644
 645                 if (tmpl->mode) {
 646                         remote = &tmpl->id.daddr;
 647                         local = &tmpl->saddr;
 648                 }
 649
 650                 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
 651
 652                 if (x && x->km.state == XFRM_STATE_VALID) {
 653                         xfrm[nx++] = x;
 654                         daddr = remote;
 655                         saddr = local;
 656                         continue;
 657                 }
 658                 if (x) {
 659                         error = (x->km.state == XFRM_STATE_ERROR ?
 660                                  -EINVAL : -EAGAIN);
 661                         xfrm_state_put(x);
 662                 }
 663
 664                 if (!tmpl->optional)
 665                         goto fail;
 666         }
 667         return nx;
 668
 669 fail:
 670         for (nx--; nx>=0; nx--)
 671                 xfrm_state_put(xfrm[nx]);
 672         return error;
 673 }
 674
 675 /* Check that the bundle accepts the flow and its components are
 676  * still valid.
 677  */
 678
 679 static struct dst_entry *
 680 xfrm_find_bundle(struct flowi *fl, struct xfrm_policy *policy, unsigned short family)
 681 {
 682         struct dst_entry *x;
 683         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
 684         if (unlikely(afinfo == NULL))
 685                 return ERR_PTR(-EINVAL);
 686         x = afinfo->find_bundle(fl, policy);
 687         xfrm_policy_put_afinfo(afinfo);
 688         return x;
 689 }
 690
 691 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
 692  * all the metrics... Shortly, bundle a bundle.
 693  */
 694
 695 static int
 696 xfrm_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
 697                    struct flowi *fl, struct dst_entry **dst_p,
 698                    unsigned short family)
 699 {
 700         int err;
 701         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
 702         if (unlikely(afinfo == NULL))
 703                 return -EINVAL;
 704         err = afinfo->bundle_create(policy, xfrm, nx, fl, dst_p);
 705         xfrm_policy_put_afinfo(afinfo);
 706         return err;
 707 }
 708
 709 static inline int policy_to_flow_dir(int dir)
 710 {
 711         if (XFRM_POLICY_IN == FLOW_DIR_IN &&
 712             XFRM_POLICY_OUT == FLOW_DIR_OUT &&
 713             XFRM_POLICY_FWD == FLOW_DIR_FWD)
 714                 return dir;
 715         switch (dir) {
 716         default:
 717         case XFRM_POLICY_IN:
 718                 return FLOW_DIR_IN;
 719         case XFRM_POLICY_OUT:
 720                 return FLOW_DIR_OUT;
 721         case XFRM_POLICY_FWD:
 722                 return FLOW_DIR_FWD;
 723         };
 724 }
 725
 726 static int stale_bundle(struct dst_entry *dst);
 727
 728 /* Main function: finds/creates a bundle for given flow.
 729  *
 730  * At the moment we eat a raw IP route. Mostly to speed up lookups
 731  * on interfaces with disabled IPsec.
 732  */
 733 int xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
 734                 struct sock *sk, int flags)
 735 {
 736         struct xfrm_policy *policy;
 737         struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
 738         struct dst_entry *dst, *dst_orig = *dst_p;
 739         int nx = 0;
 740         int err;
 741         u32 genid;
 742         u16 family = dst_orig->ops->family;
 743 restart:
 744         genid = atomic_read(&flow_cache_genid);
 745         policy = NULL;
 746         if (sk && sk->sk_policy[1])
 747                 policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
 748
 749         if (!policy) {
 750                 /* To accelerate a bit...  */
 751                 if ((dst_orig->flags & DST_NOXFRM) || !xfrm_policy_list[XFRM_POLICY_OUT])
 752                         return 0;
 753
 754                 policy = flow_cache_lookup(fl, family,
 755                                            policy_to_flow_dir(XFRM_POLICY_OUT),
 756                                            xfrm_policy_lookup);
 757         }
 758
 759         if (!policy)
 760                 return 0;
 761
 762         policy->curlft.use_time = (unsigned long)xtime.tv_sec;
 763
 764         switch (policy->action) {
 765         case XFRM_POLICY_BLOCK:
 766                 /* Prohibit the flow */
 767                 xfrm_pol_put(policy);
 768                 return -EPERM;
 769
 770         case XFRM_POLICY_ALLOW:
 771                 if (policy->xfrm_nr == 0) {
 772                         /* Flow passes not transformed. */
 773                         xfrm_pol_put(policy);
 774                         return 0;
 775                 }
 776
 777                 /* Try to find matching bundle.
 778                  *
 779                  * LATER: help from flow cache. It is optional, this
 780                  * is required only for output policy.
 781                  */
 782                 dst = xfrm_find_bundle(fl, policy, family);
 783                 if (IS_ERR(dst)) {
 784                         xfrm_pol_put(policy);
 785                         return PTR_ERR(dst);
 786                 }
 787
 788                 if (dst)
 789                         break;
 790
 791                 nx = xfrm_tmpl_resolve(policy, fl, xfrm, family);
 792
 793                 if (unlikely(nx<0)) {
 794                         err = nx;
 795                         if (err == -EAGAIN && flags) {
 796                                 DECLARE_WAITQUEUE(wait, current);
 797
 798                                 add_wait_queue(&km_waitq, &wait);
 799                                 set_current_state(TASK_INTERRUPTIBLE);
 800                                 schedule();
 801                                 set_current_state(TASK_RUNNING);
 802                                 remove_wait_queue(&km_waitq, &wait);
 803
 804                                 nx = xfrm_tmpl_resolve(policy, fl, xfrm, family);
 805
 806                                 if (nx == -EAGAIN && signal_pending(current)) {
 807                                         err = -ERESTART;
 808                                         goto error;
 809                                 }
 810                                 if (nx == -EAGAIN ||
 811                                     genid != atomic_read(&flow_cache_genid)) {
 812                                         xfrm_pol_put(policy);
 813                                         goto restart;
 814                                 }
 815                                 err = nx;
 816                         }
 817                         if (err < 0)
 818                                 goto error;
 819                 }
 820                 if (nx == 0) {
 821                         /* Flow passes not transformed. */
 822                         xfrm_pol_put(policy);
 823                         return 0;
 824                 }
 825
 826                 dst = dst_orig;
 827                 err = xfrm_bundle_create(policy, xfrm, nx, fl, &dst, family);
 828
 829                 if (unlikely(err)) {
 830                         int i;
 831                         for (i=0; i<nx; i++)
 832                                 xfrm_state_put(xfrm[i]);
 833                         goto error;
 834                 }
 835
 836                 write_lock_bh(&policy->lock);
 837                 if (unlikely(policy->dead || stale_bundle(dst))) {
 838                         /* Wow! While we worked on resolving, this
 839                          * policy has gone. Retry. It is not paranoia,
 840                          * we just cannot enlist new bundle to dead object.
 841                          * We can't enlist stable bundles either.
 842                          */
 843                         write_unlock_bh(&policy->lock);
 844
 845                         xfrm_pol_put(policy);
 846                         if (dst)
 847                                 dst_free(dst);
 848                         goto restart;
 849                 }
 850                 dst->next = policy->bundles;
 851                 policy->bundles = dst;
 852                 dst_hold(dst);
 853                 write_unlock_bh(&policy->lock);
 854         }
 855         *dst_p = dst;
 856         dst_release(dst_orig);
 857         xfrm_pol_put(policy);
 858         return 0;
 859
 860 error:
 861         dst_release(dst_orig);
 862         xfrm_pol_put(policy);
 863         *dst_p = NULL;
 864         return err;
 865 }
 866 EXPORT_SYMBOL(xfrm_lookup);
 867
 868 /* When skb is transformed back to its "native" form, we have to
 869  * check policy restrictions. At the moment we make this in maximally
 870  * stupid way. Shame on me. :-) Of course, connected sockets must
 871  * have policy cached at them.
 872  */
 873
 874 static inline int
 875 xfrm_state_ok(struct xfrm_tmpl *tmpl, struct xfrm_state *x,
 876               unsigned short family)
 877 {
 878         if (xfrm_state_kern(x))
 879                 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, family);
 880         return  x->id.proto == tmpl->id.proto &&
 881                 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
 882                 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
 883                 x->props.mode == tmpl->mode &&
 884                 (tmpl->aalgos & (1<<x->props.aalgo)) &&
 885                 !(x->props.mode && xfrm_state_addr_cmp(tmpl, x, family));
 886 }
 887
 888 static inline int
 889 xfrm_policy_ok(struct xfrm_tmpl *tmpl, struct sec_path *sp, int start,
 890                unsigned short family)
 891 {
 892         int idx = start;
 893
 894         if (tmpl->optional) {
 895                 if (!tmpl->mode)
 896                         return start;
 897         } else
 898                 start = -1;
 899         for (; idx < sp->len; idx++) {
 900                 if (xfrm_state_ok(tmpl, sp->x[idx].xvec, family))
 901                         return ++idx;
 902                 if (sp->x[idx].xvec->props.mode)
 903                         break;
 904         }
 905         return start;
 906 }
 907
 908 static int
 909 _decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family)
 910 {
 911         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
 912
 913         if (unlikely(afinfo == NULL))
 914                 return -EAFNOSUPPORT;
 915
 916         afinfo->decode_session(skb, fl);
 917         xfrm_policy_put_afinfo(afinfo);
 918         return 0;
 919 }
 920
 921 static inline int secpath_has_tunnel(struct sec_path *sp, int k)
 922 {
 923         for (; k < sp->len; k++) {
 924                 if (sp->x[k].xvec->props.mode)
 925                         return 1;
 926         }
 927
 928         return 0;
 929 }
 930
 931 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
 932                         unsigned short family)
 933 {
 934         struct xfrm_policy *pol;
 935         struct flowi fl;
 936
 937         if (_decode_session(skb, &fl, family) < 0)
 938                 return 0;
 939
 940         /* First, check used SA against their selectors. */
 941         if (skb->sp) {
 942                 int i;
 943
 944                 for (i=skb->sp->len-1; i>=0; i--) {
 945                   struct sec_decap_state *xvec = &(skb->sp->x[i]);
 946                         if (!xfrm_selector_match(&xvec->xvec->sel, &fl, family))
 947                                 return 0;
 948
 949                         /* If there is a post_input processor, try running it */
 950                         if (xvec->xvec->type->post_input &&
 951                             (xvec->xvec->type->post_input)(xvec->xvec,
 952                                                            &(xvec->decap),
 953                                                            skb) != 0)
 954                                 return 0;
 955                 }
 956         }
 957
 958         pol = NULL;
 959         if (sk && sk->sk_policy[dir])
 960                 pol = xfrm_sk_policy_lookup(sk, dir, &fl);
 961
 962         if (!pol)
 963                 pol = flow_cache_lookup(&fl, family,
 964                                         policy_to_flow_dir(dir),
 965                                         xfrm_policy_lookup);
 966
 967         if (!pol)
 968                 return !skb->sp || !secpath_has_tunnel(skb->sp, 0);
 969
 970         pol->curlft.use_time = (unsigned long)xtime.tv_sec;
 971
 972         if (pol->action == XFRM_POLICY_ALLOW) {
 973                 struct sec_path *sp;
 974                 static struct sec_path dummy;
 975                 int i, k;
 976
 977                 if ((sp = skb->sp) == NULL)
 978                         sp = &dummy;
 979
 980                 /* For each tunnel xfrm, find the first matching tmpl.
 981                  * For each tmpl before that, find corresponding xfrm.
 982                  * Order is _important_. Later we will implement
 983                  * some barriers, but at the moment barriers
 984                  * are implied between each two transformations.
 985                  */
 986                 for (i = pol->xfrm_nr-1, k = 0; i >= 0; i--) {
 987                         k = xfrm_policy_ok(pol->xfrm_vec+i, sp, k, family);
 988                         if (k < 0)
 989                                 goto reject;
 990                 }
 991
 992                 if (secpath_has_tunnel(sp, k))
 993                         goto reject;
 994
 995                 xfrm_pol_put(pol);
 996                 return 1;
 997         }
 998
 999 reject:
1000         xfrm_pol_put(pol);
1001         return 0;
1002 }
1003 EXPORT_SYMBOL(__xfrm_policy_check);
1004
1005 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
1006 {
1007         struct flowi fl;
1008
1009         if (_decode_session(skb, &fl, family) < 0)
1010                 return 0;
1011
1012         return xfrm_lookup(&skb->dst, &fl, NULL, 0) == 0;
1013 }
1014 EXPORT_SYMBOL(__xfrm_route_forward);
1015
1016 /* Optimize later using cookies and generation ids. */
1017
1018 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
1019 {
1020         if (!stale_bundle(dst))
1021                 return dst;
1022
1023         return NULL;
1024 }
1025
1026 static int stale_bundle(struct dst_entry *dst)
1027 {
1028         return !xfrm_bundle_ok((struct xfrm_dst *)dst, NULL, AF_UNSPEC);
1029 }
1030
1031 static void xfrm_dst_destroy(struct dst_entry *dst)
1032 {
1033         struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1034
1035         dst_release(xdst->route);
1036
1037         if (!dst->xfrm)
1038                 return;
1039         xfrm_state_put(dst->xfrm);
1040         dst->xfrm = NULL;
1041 }
1042
1043 static void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
1044                             int unregister)
1045 {
1046         if (!unregister)
1047                 return;
1048
1049         while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
1050                 dst->dev = &loopback_dev;
1051                 dev_hold(&loopback_dev);
1052                 dev_put(dev);
1053         }
1054 }
1055
1056 static void xfrm_link_failure(struct sk_buff *skb)
1057 {
1058         /* Impossible. Such dst must be popped before reaches point of failure. */
1059         return;
1060 }
1061
1062 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
1063 {
1064         if (dst) {
1065                 if (dst->obsolete) {
1066                         dst_release(dst);
1067                         dst = NULL;
1068                 }
1069         }
1070         return dst;
1071 }
1072
1073 static void xfrm_prune_bundles(int (*func)(struct dst_entry *))
1074 {
1075         int i;
1076         struct xfrm_policy *pol;
1077         struct dst_entry *dst, **dstp, *gc_list = NULL;
1078
1079         read_lock_bh(&xfrm_policy_lock);
1080         for (i=0; i<2*XFRM_POLICY_MAX; i++) {
1081                 for (pol = xfrm_policy_list[i]; pol; pol = pol->next) {
1082                         write_lock(&pol->lock);
1083                         dstp = &pol->bundles;
1084                         while ((dst=*dstp) != NULL) {
1085                                 if (func(dst)) {
1086                                         *dstp = dst->next;
1087                                         dst->next = gc_list;
1088                                         gc_list = dst;
1089                                 } else {
1090                                         dstp = &dst->next;
1091                                 }
1092                         }
1093                         write_unlock(&pol->lock);
1094                 }
1095         }
1096         read_unlock_bh(&xfrm_policy_lock);
1097
1098         while (gc_list) {
1099                 dst = gc_list;
1100                 gc_list = dst->next;
1101                 dst_free(dst);
1102         }
1103 }
1104
1105 static int unused_bundle(struct dst_entry *dst)
1106 {
1107         return !atomic_read(&dst->__refcnt);
1108 }
1109
1110 static void __xfrm_garbage_collect(void)
1111 {
1112         xfrm_prune_bundles(unused_bundle);
1113 }
1114
1115 int xfrm_flush_bundles(void)
1116 {
1117         xfrm_prune_bundles(stale_bundle);
1118         return 0;
1119 }
1120
1121 void xfrm_init_pmtu(struct dst_entry *dst)
1122 {
1123         do {
1124                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1125                 u32 pmtu, route_mtu_cached;
1126
1127                 pmtu = dst_mtu(dst->child);
1128                 xdst->child_mtu_cached = pmtu;
1129
1130                 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
1131
1132                 route_mtu_cached = dst_mtu(xdst->route);
1133                 xdst->route_mtu_cached = route_mtu_cached;
1134
1135                 if (pmtu > route_mtu_cached)
1136                         pmtu = route_mtu_cached;
1137
1138                 dst->metrics[RTAX_MTU-1] = pmtu;
1139         } while ((dst = dst->next));
1140 }
1141
1142 EXPORT_SYMBOL(xfrm_init_pmtu);
1143
1144 /* Check that the bundle accepts the flow and its components are
1145  * still valid.
1146  */
1147
1148 int xfrm_bundle_ok(struct xfrm_dst *first, struct flowi *fl, int family)
1149 {
1150         struct dst_entry *dst = &first->u.dst;
1151         struct xfrm_dst *last;
1152         u32 mtu;
1153
1154         if (!dst_check(dst->path, 0) ||
1155             (dst->dev && !netif_running(dst->dev)))
1156                 return 0;
1157
1158         last = NULL;
1159
1160         do {
1161                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1162
1163                 if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family))
1164                         return 0;
1165                 if (dst->xfrm->km.state != XFRM_STATE_VALID)
1166                         return 0;
1167
1168                 mtu = dst_mtu(dst->child);
1169                 if (xdst->child_mtu_cached != mtu) {
1170                         last = xdst;
1171                         xdst->child_mtu_cached = mtu;
1172                 }
1173
1174                 if (!dst_check(xdst->route, 0))
1175                         return 0;
1176                 mtu = dst_mtu(xdst->route);
1177                 if (xdst->route_mtu_cached != mtu) {
1178                         last = xdst;
1179                         xdst->route_mtu_cached = mtu;
1180                 }
1181
1182                 dst = dst->child;
1183         } while (dst->xfrm);
1184
1185         if (likely(!last))
1186                 return 1;
1187
1188         mtu = last->child_mtu_cached;
1189         for (;;) {
1190                 dst = &last->u.dst;
1191
1192                 mtu = xfrm_state_mtu(dst->xfrm, mtu);
1193                 if (mtu > last->route_mtu_cached)
1194                         mtu = last->route_mtu_cached;
1195                 dst->metrics[RTAX_MTU-1] = mtu;
1196
1197                 if (last == first)
1198                         break;
1199
1200                 last = last->u.next;
1201                 last->child_mtu_cached = mtu;
1202         }
1203
1204         return 1;
1205 }
1206
1207 EXPORT_SYMBOL(xfrm_bundle_ok);
1208
1209 /* Well... that's _TASK_. We need to scan through transformation
1210  * list and figure out what mss tcp should generate in order to
1211  * final datagram fit to mtu. Mama mia... :-)
1212  *
1213  * Apparently, some easy way exists, but we used to choose the most
1214  * bizarre ones. :-) So, raising Kalashnikov... tra-ta-ta.
1215  *
1216  * Consider this function as something like dark humour. :-)
1217  */
1218 static int xfrm_get_mss(struct dst_entry *dst, u32 mtu)
1219 {
1220         int res = mtu - dst->header_len;
1221
1222         for (;;) {
1223                 struct dst_entry *d = dst;
1224                 int m = res;
1225
1226                 do {
1227                         struct xfrm_state *x = d->xfrm;
1228                         if (x) {
1229                                 spin_lock_bh(&x->lock);
1230                                 if (x->km.state == XFRM_STATE_VALID &&
1231                                     x->type && x->type->get_max_size)
1232                                         m = x->type->get_max_size(d->xfrm, m);
1233                                 else
1234                                         m += x->props.header_len;
1235                                 spin_unlock_bh(&x->lock);
1236                         }
1237                 } while ((d = d->child) != NULL);
1238
1239                 if (m <= mtu)
1240                         break;
1241                 res -= (m - mtu);
1242                 if (res < 88)
1243                         return mtu;
1244         }
1245
1246         return res + dst->header_len;
1247 }
1248
1249 int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
1250 {
1251         int err = 0;
1252         if (unlikely(afinfo == NULL))
1253                 return -EINVAL;
1254         if (unlikely(afinfo->family >= NPROTO))
1255                 return -EAFNOSUPPORT;
1256         write_lock(&xfrm_policy_afinfo_lock);
1257         if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
1258                 err = -ENOBUFS;
1259         else {
1260                 struct dst_ops *dst_ops = afinfo->dst_ops;
1261                 if (likely(dst_ops->kmem_cachep == NULL))
1262                         dst_ops->kmem_cachep = xfrm_dst_cache;
1263                 if (likely(dst_ops->check == NULL))
1264                         dst_ops->check = xfrm_dst_check;
1265                 if (likely(dst_ops->destroy == NULL))
1266                         dst_ops->destroy = xfrm_dst_destroy;
1267                 if (likely(dst_ops->ifdown == NULL))
1268                         dst_ops->ifdown = xfrm_dst_ifdown;
1269                 if (likely(dst_ops->negative_advice == NULL))
1270                         dst_ops->negative_advice = xfrm_negative_advice;
1271                 if (likely(dst_ops->link_failure == NULL))
1272                         dst_ops->link_failure = xfrm_link_failure;
1273                 if (likely(dst_ops->get_mss == NULL))
1274                         dst_ops->get_mss = xfrm_get_mss;
1275                 if (likely(afinfo->garbage_collect == NULL))
1276                         afinfo->garbage_collect = __xfrm_garbage_collect;
1277                 xfrm_policy_afinfo[afinfo->family] = afinfo;
1278         }
1279         write_unlock(&xfrm_policy_afinfo_lock);
1280         return err;
1281 }
1282 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
1283
1284 int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
1285 {
1286         int err = 0;
1287         if (unlikely(afinfo == NULL))
1288                 return -EINVAL;
1289         if (unlikely(afinfo->family >= NPROTO))
1290                 return -EAFNOSUPPORT;
1291         write_lock(&xfrm_policy_afinfo_lock);
1292         if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
1293                 if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
1294                         err = -EINVAL;
1295                 else {
1296                         struct dst_ops *dst_ops = afinfo->dst_ops;
1297                         xfrm_policy_afinfo[afinfo->family] = NULL;
1298                         dst_ops->kmem_cachep = NULL;
1299                         dst_ops->check = NULL;
1300                         dst_ops->destroy = NULL;
1301                         dst_ops->ifdown = NULL;
1302                         dst_ops->negative_advice = NULL;
1303                         dst_ops->link_failure = NULL;
1304                         dst_ops->get_mss = NULL;
1305                         afinfo->garbage_collect = NULL;
1306                 }
1307         }
1308         write_unlock(&xfrm_policy_afinfo_lock);
1309         return err;
1310 }
1311 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
1312
1313 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
1314 {
1315         struct xfrm_policy_afinfo *afinfo;
1316         if (unlikely(family >= NPROTO))
1317                 return NULL;
1318         read_lock(&xfrm_policy_afinfo_lock);
1319         afinfo = xfrm_policy_afinfo[family];
1320         if (likely(afinfo != NULL))
1321                 read_lock(&afinfo->lock);
1322         read_unlock(&xfrm_policy_afinfo_lock);
1323         return afinfo;
1324 }
1325
1326 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
1327 {
1328         if (unlikely(afinfo == NULL))
1329                 return;
1330         read_unlock(&afinfo->lock);
1331 }
1332
1333 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
1334 {
1335         switch (event) {
1336         case NETDEV_DOWN:
1337                 xfrm_flush_bundles();
1338         }
1339         return NOTIFY_DONE;
1340 }
1341
1342 static struct notifier_block xfrm_dev_notifier = {
1343         xfrm_dev_event,
1344         NULL,
1345         0
1346 };
1347
1348 static void __init xfrm_policy_init(void)
1349 {
1350         xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
1351                                            sizeof(struct xfrm_dst),
1352                                            0, SLAB_HWCACHE_ALIGN,
1353                                            NULL, NULL);
1354         if (!xfrm_dst_cache)
1355                 panic("XFRM: failed to allocate xfrm_dst_cache\n");
1356
1357         INIT_WORK(&xfrm_policy_gc_work, xfrm_policy_gc_task, NULL);
1358         register_netdevice_notifier(&xfrm_dev_notifier);
1359 }
1360
1361 void __init xfrm_init(void)
1362 {
1363         xfrm_state_init();
1364         xfrm_policy_init();
1365         xfrm_input_init();
1366 }
1367