net/xfrm/xfrm_policy.c

   1 /*
   2  * xfrm_policy.c
   3  *
   4  * Changes:
   5  *      Mitsuru KANDA @USAGI
   6  *      Kazunori MIYAZAWA @USAGI
   7  *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
   8  *              IPv6 support
   9  *      Kazunori MIYAZAWA @USAGI
  10  *      YOSHIFUJI Hideaki
  11  *              Split up af-specific portion
  12  *      Derek Atkins <derek@ihtfp.com>          Add the post_input processor
  13  *
  14  */
  15
  16 #include <linux/slab.h>
  17 #include <linux/kmod.h>
  18 #include <linux/list.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/workqueue.h>
  21 #include <linux/notifier.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/netfilter.h>
  24 #include <linux/module.h>
  25 #include <linux/cache.h>
  26 #include <net/xfrm.h>
  27 #include <net/ip.h>
  28 #include <linux/audit.h>
  29
  30 #include "xfrm_hash.h"
  31
  32 DEFINE_MUTEX(xfrm_cfg_mutex);
  33 EXPORT_SYMBOL(xfrm_cfg_mutex);
  34
  35 static DEFINE_RWLOCK(xfrm_policy_lock);
  36
  37 unsigned int xfrm_policy_count[XFRM_POLICY_MAX*2];
  38 EXPORT_SYMBOL(xfrm_policy_count);
  39
  40 static DEFINE_RWLOCK(xfrm_policy_afinfo_lock);
  41 static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO];
  42
  43 static struct kmem_cache *xfrm_dst_cache __read_mostly;
  44
  45 static struct work_struct xfrm_policy_gc_work;
  46 static HLIST_HEAD(xfrm_policy_gc_list);
  47 static DEFINE_SPINLOCK(xfrm_policy_gc_lock);
  48
  49 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family);
  50 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);
  51 static struct xfrm_policy_afinfo *xfrm_policy_lock_afinfo(unsigned int family);
  52 static void xfrm_policy_unlock_afinfo(struct xfrm_policy_afinfo *afinfo);
  53
  54 static inline int
  55 __xfrm4_selector_match(struct xfrm_selector *sel, struct flowi *fl)
  56 {
  57         return  addr_match(&fl->fl4_dst, &sel->daddr, sel->prefixlen_d) &&
  58                 addr_match(&fl->fl4_src, &sel->saddr, sel->prefixlen_s) &&
  59                 !((xfrm_flowi_dport(fl) ^ sel->dport) & sel->dport_mask) &&
  60                 !((xfrm_flowi_sport(fl) ^ sel->sport) & sel->sport_mask) &&
  61                 (fl->proto == sel->proto || !sel->proto) &&
  62                 (fl->oif == sel->ifindex || !sel->ifindex);
  63 }
  64
  65 static inline int
  66 __xfrm6_selector_match(struct xfrm_selector *sel, struct flowi *fl)
  67 {
  68         return  addr_match(&fl->fl6_dst, &sel->daddr, sel->prefixlen_d) &&
  69                 addr_match(&fl->fl6_src, &sel->saddr, sel->prefixlen_s) &&
  70                 !((xfrm_flowi_dport(fl) ^ sel->dport) & sel->dport_mask) &&
  71                 !((xfrm_flowi_sport(fl) ^ sel->sport) & sel->sport_mask) &&
  72                 (fl->proto == sel->proto || !sel->proto) &&
  73                 (fl->oif == sel->ifindex || !sel->ifindex);
  74 }
  75
  76 int xfrm_selector_match(struct xfrm_selector *sel, struct flowi *fl,
  77                     unsigned short family)
  78 {
  79         switch (family) {
  80         case AF_INET:
  81                 return __xfrm4_selector_match(sel, fl);
  82         case AF_INET6:
  83                 return __xfrm6_selector_match(sel, fl);
  84         }
  85         return 0;
  86 }
  87
  88 int xfrm_register_type(struct xfrm_type *type, unsigned short family)
  89 {
  90         struct xfrm_policy_afinfo *afinfo = xfrm_policy_lock_afinfo(family);
  91         struct xfrm_type **typemap;
  92         int err = 0;
  93
  94         if (unlikely(afinfo == NULL))
  95                 return -EAFNOSUPPORT;
  96         typemap = afinfo->type_map;
  97
  98         if (likely(typemap[type->proto] == NULL))
  99                 typemap[type->proto] = type;
 100         else
 101                 err = -EEXIST;
 102         xfrm_policy_unlock_afinfo(afinfo);
 103         return err;
 104 }
 105 EXPORT_SYMBOL(xfrm_register_type);
 106
 107 int xfrm_unregister_type(struct xfrm_type *type, unsigned short family)
 108 {
 109         struct xfrm_policy_afinfo *afinfo = xfrm_policy_lock_afinfo(family);
 110         struct xfrm_type **typemap;
 111         int err = 0;
 112
 113         if (unlikely(afinfo == NULL))
 114                 return -EAFNOSUPPORT;
 115         typemap = afinfo->type_map;
 116
 117         if (unlikely(typemap[type->proto] != type))
 118                 err = -ENOENT;
 119         else
 120                 typemap[type->proto] = NULL;
 121         xfrm_policy_unlock_afinfo(afinfo);
 122         return err;
 123 }
 124 EXPORT_SYMBOL(xfrm_unregister_type);
 125
 126 struct xfrm_type *xfrm_get_type(u8 proto, unsigned short family)
 127 {
 128         struct xfrm_policy_afinfo *afinfo;
 129         struct xfrm_type **typemap;
 130         struct xfrm_type *type;
 131         int modload_attempted = 0;
 132
 133 retry:
 134         afinfo = xfrm_policy_get_afinfo(family);
 135         if (unlikely(afinfo == NULL))
 136                 return NULL;
 137         typemap = afinfo->type_map;
 138
 139         type = typemap[proto];
 140         if (unlikely(type && !try_module_get(type->owner)))
 141                 type = NULL;
 142         if (!type && !modload_attempted) {
 143                 xfrm_policy_put_afinfo(afinfo);
 144                 request_module("xfrm-type-%d-%d",
 145                                (int) family, (int) proto);
 146                 modload_attempted = 1;
 147                 goto retry;
 148         }
 149
 150         xfrm_policy_put_afinfo(afinfo);
 151         return type;
 152 }
 153
 154 int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl,
 155                     unsigned short family)
 156 {
 157         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
 158         int err = 0;
 159
 160         if (unlikely(afinfo == NULL))
 161                 return -EAFNOSUPPORT;
 162
 163         if (likely(afinfo->dst_lookup != NULL))
 164                 err = afinfo->dst_lookup(dst, fl);
 165         else
 166                 err = -EINVAL;
 167         xfrm_policy_put_afinfo(afinfo);
 168         return err;
 169 }
 170 EXPORT_SYMBOL(xfrm_dst_lookup);
 171
 172 void xfrm_put_type(struct xfrm_type *type)
 173 {
 174         module_put(type->owner);
 175 }
 176
 177 int xfrm_register_mode(struct xfrm_mode *mode, int family)
 178 {
 179         struct xfrm_policy_afinfo *afinfo;
 180         struct xfrm_mode **modemap;
 181         int err;
 182
 183         if (unlikely(mode->encap >= XFRM_MODE_MAX))
 184                 return -EINVAL;
 185
 186         afinfo = xfrm_policy_lock_afinfo(family);
 187         if (unlikely(afinfo == NULL))
 188                 return -EAFNOSUPPORT;
 189
 190         err = -EEXIST;
 191         modemap = afinfo->mode_map;
 192         if (likely(modemap[mode->encap] == NULL)) {
 193                 modemap[mode->encap] = mode;
 194                 err = 0;
 195         }
 196
 197         xfrm_policy_unlock_afinfo(afinfo);
 198         return err;
 199 }
 200 EXPORT_SYMBOL(xfrm_register_mode);
 201
 202 int xfrm_unregister_mode(struct xfrm_mode *mode, int family)
 203 {
 204         struct xfrm_policy_afinfo *afinfo;
 205         struct xfrm_mode **modemap;
 206         int err;
 207
 208         if (unlikely(mode->encap >= XFRM_MODE_MAX))
 209                 return -EINVAL;
 210
 211         afinfo = xfrm_policy_lock_afinfo(family);
 212         if (unlikely(afinfo == NULL))
 213                 return -EAFNOSUPPORT;
 214
 215         err = -ENOENT;
 216         modemap = afinfo->mode_map;
 217         if (likely(modemap[mode->encap] == mode)) {
 218                 modemap[mode->encap] = NULL;
 219                 err = 0;
 220         }
 221
 222         xfrm_policy_unlock_afinfo(afinfo);
 223         return err;
 224 }
 225 EXPORT_SYMBOL(xfrm_unregister_mode);
 226
 227 struct xfrm_mode *xfrm_get_mode(unsigned int encap, int family)
 228 {
 229         struct xfrm_policy_afinfo *afinfo;
 230         struct xfrm_mode *mode;
 231         int modload_attempted = 0;
 232
 233         if (unlikely(encap >= XFRM_MODE_MAX))
 234                 return NULL;
 235
 236 retry:
 237         afinfo = xfrm_policy_get_afinfo(family);
 238         if (unlikely(afinfo == NULL))
 239                 return NULL;
 240
 241         mode = afinfo->mode_map[encap];
 242         if (unlikely(mode && !try_module_get(mode->owner)))
 243                 mode = NULL;
 244         if (!mode && !modload_attempted) {
 245                 xfrm_policy_put_afinfo(afinfo);
 246                 request_module("xfrm-mode-%d-%d", family, encap);
 247                 modload_attempted = 1;
 248                 goto retry;
 249         }
 250
 251         xfrm_policy_put_afinfo(afinfo);
 252         return mode;
 253 }
 254
 255 void xfrm_put_mode(struct xfrm_mode *mode)
 256 {
 257         module_put(mode->owner);
 258 }
 259
 260 static inline unsigned long make_jiffies(long secs)
 261 {
 262         if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
 263                 return MAX_SCHEDULE_TIMEOUT-1;
 264         else
 265                 return secs*HZ;
 266 }
 267
 268 static void xfrm_policy_timer(unsigned long data)
 269 {
 270         struct xfrm_policy *xp = (struct xfrm_policy*)data;
 271         unsigned long now = get_seconds();
 272         long next = LONG_MAX;
 273         int warn = 0;
 274         int dir;
 275
 276         read_lock(&xp->lock);
 277
 278         if (xp->dead)
 279                 goto out;
 280
 281         dir = xfrm_policy_id2dir(xp->index);
 282
 283         if (xp->lft.hard_add_expires_seconds) {
 284                 long tmo = xp->lft.hard_add_expires_seconds +
 285                         xp->curlft.add_time - now;
 286                 if (tmo <= 0)
 287                         goto expired;
 288                 if (tmo < next)
 289                         next = tmo;
 290         }
 291         if (xp->lft.hard_use_expires_seconds) {
 292                 long tmo = xp->lft.hard_use_expires_seconds +
 293                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 294                 if (tmo <= 0)
 295                         goto expired;
 296                 if (tmo < next)
 297                         next = tmo;
 298         }
 299         if (xp->lft.soft_add_expires_seconds) {
 300                 long tmo = xp->lft.soft_add_expires_seconds +
 301                         xp->curlft.add_time - now;
 302                 if (tmo <= 0) {
 303                         warn = 1;
 304                         tmo = XFRM_KM_TIMEOUT;
 305                 }
 306                 if (tmo < next)
 307                         next = tmo;
 308         }
 309         if (xp->lft.soft_use_expires_seconds) {
 310                 long tmo = xp->lft.soft_use_expires_seconds +
 311                         (xp->curlft.use_time ? : xp->curlft.add_time) - now;
 312                 if (tmo <= 0) {
 313                         warn = 1;
 314                         tmo = XFRM_KM_TIMEOUT;
 315                 }
 316                 if (tmo < next)
 317                         next = tmo;
 318         }
 319
 320         if (warn)
 321                 km_policy_expired(xp, dir, 0, 0);
 322         if (next != LONG_MAX &&
 323             !mod_timer(&xp->timer, jiffies + make_jiffies(next)))
 324                 xfrm_pol_hold(xp);
 325
 326 out:
 327         read_unlock(&xp->lock);
 328         xfrm_pol_put(xp);
 329         return;
 330
 331 expired:
 332         read_unlock(&xp->lock);
 333         if (!xfrm_policy_delete(xp, dir))
 334                 km_policy_expired(xp, dir, 1, 0);
 335         xfrm_pol_put(xp);
 336 }
 337
 338
 339 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
 340  * SPD calls.
 341  */
 342
 343 struct xfrm_policy *xfrm_policy_alloc(gfp_t gfp)
 344 {
 345         struct xfrm_policy *policy;
 346
 347         policy = kzalloc(sizeof(struct xfrm_policy), gfp);
 348
 349         if (policy) {
 350                 INIT_HLIST_NODE(&policy->bydst);
 351                 INIT_HLIST_NODE(&policy->byidx);
 352                 rwlock_init(&policy->lock);
 353                 atomic_set(&policy->refcnt, 1);
 354                 init_timer(&policy->timer);
 355                 policy->timer.data = (unsigned long)policy;
 356                 policy->timer.function = xfrm_policy_timer;
 357         }
 358         return policy;
 359 }
 360 EXPORT_SYMBOL(xfrm_policy_alloc);
 361
 362 /* Destroy xfrm_policy: descendant resources must be released to this moment. */
 363
 364 void __xfrm_policy_destroy(struct xfrm_policy *policy)
 365 {
 366         BUG_ON(!policy->dead);
 367
 368         BUG_ON(policy->bundles);
 369
 370         if (del_timer(&policy->timer))
 371                 BUG();
 372
 373         security_xfrm_policy_free(policy);
 374         kfree(policy);
 375 }
 376 EXPORT_SYMBOL(__xfrm_policy_destroy);
 377
 378 static void xfrm_policy_gc_kill(struct xfrm_policy *policy)
 379 {
 380         struct dst_entry *dst;
 381
 382         while ((dst = policy->bundles) != NULL) {
 383                 policy->bundles = dst->next;
 384                 dst_free(dst);
 385         }
 386
 387         if (del_timer(&policy->timer))
 388                 atomic_dec(&policy->refcnt);
 389
 390         if (atomic_read(&policy->refcnt) > 1)
 391                 flow_cache_flush();
 392
 393         xfrm_pol_put(policy);
 394 }
 395
 396 static void xfrm_policy_gc_task(struct work_struct *work)
 397 {
 398         struct xfrm_policy *policy;
 399         struct hlist_node *entry, *tmp;
 400         struct hlist_head gc_list;
 401
 402         spin_lock_bh(&xfrm_policy_gc_lock);
 403         gc_list.first = xfrm_policy_gc_list.first;
 404         INIT_HLIST_HEAD(&xfrm_policy_gc_list);
 405         spin_unlock_bh(&xfrm_policy_gc_lock);
 406
 407         hlist_for_each_entry_safe(policy, entry, tmp, &gc_list, bydst)
 408                 xfrm_policy_gc_kill(policy);
 409 }
 410
 411 /* Rule must be locked. Release descentant resources, announce
 412  * entry dead. The rule must be unlinked from lists to the moment.
 413  */
 414
 415 static void xfrm_policy_kill(struct xfrm_policy *policy)
 416 {
 417         int dead;
 418
 419         write_lock_bh(&policy->lock);
 420         dead = policy->dead;
 421         policy->dead = 1;
 422         write_unlock_bh(&policy->lock);
 423
 424         if (unlikely(dead)) {
 425                 WARN_ON(1);
 426                 return;
 427         }
 428
 429         spin_lock(&xfrm_policy_gc_lock);
 430         hlist_add_head(&policy->bydst, &xfrm_policy_gc_list);
 431         spin_unlock(&xfrm_policy_gc_lock);
 432
 433         schedule_work(&xfrm_policy_gc_work);
 434 }
 435
 436 struct xfrm_policy_hash {
 437         struct hlist_head       *table;
 438         unsigned int            hmask;
 439 };
 440
 441 static struct hlist_head xfrm_policy_inexact[XFRM_POLICY_MAX*2];
 442 static struct xfrm_policy_hash xfrm_policy_bydst[XFRM_POLICY_MAX*2] __read_mostly;
 443 static struct hlist_head *xfrm_policy_byidx __read_mostly;
 444 static unsigned int xfrm_idx_hmask __read_mostly;
 445 static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024;
 446
 447 static inline unsigned int idx_hash(u32 index)
 448 {
 449         return __idx_hash(index, xfrm_idx_hmask);
 450 }
 451
 452 static struct hlist_head *policy_hash_bysel(struct xfrm_selector *sel, unsigned short family, int dir)
 453 {
 454         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
 455         unsigned int hash = __sel_hash(sel, family, hmask);
 456
 457         return (hash == hmask + 1 ?
 458                 &xfrm_policy_inexact[dir] :
 459                 xfrm_policy_bydst[dir].table + hash);
 460 }
 461
 462 static struct hlist_head *policy_hash_direct(xfrm_address_t *daddr, xfrm_address_t *saddr, unsigned short family, int dir)
 463 {
 464         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
 465         unsigned int hash = __addr_hash(daddr, saddr, family, hmask);
 466
 467         return xfrm_policy_bydst[dir].table + hash;
 468 }
 469
 470 static void xfrm_dst_hash_transfer(struct hlist_head *list,
 471                                    struct hlist_head *ndsttable,
 472                                    unsigned int nhashmask)
 473 {
 474         struct hlist_node *entry, *tmp;
 475         struct xfrm_policy *pol;
 476
 477         hlist_for_each_entry_safe(pol, entry, tmp, list, bydst) {
 478                 unsigned int h;
 479
 480                 h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
 481                                 pol->family, nhashmask);
 482                 hlist_add_head(&pol->bydst, ndsttable+h);
 483         }
 484 }
 485
 486 static void xfrm_idx_hash_transfer(struct hlist_head *list,
 487                                    struct hlist_head *nidxtable,
 488                                    unsigned int nhashmask)
 489 {
 490         struct hlist_node *entry, *tmp;
 491         struct xfrm_policy *pol;
 492
 493         hlist_for_each_entry_safe(pol, entry, tmp, list, byidx) {
 494                 unsigned int h;
 495
 496                 h = __idx_hash(pol->index, nhashmask);
 497                 hlist_add_head(&pol->byidx, nidxtable+h);
 498         }
 499 }
 500
 501 static unsigned long xfrm_new_hash_mask(unsigned int old_hmask)
 502 {
 503         return ((old_hmask + 1) << 1) - 1;
 504 }
 505
 506 static void xfrm_bydst_resize(int dir)
 507 {
 508         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
 509         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 510         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 511         struct hlist_head *odst = xfrm_policy_bydst[dir].table;
 512         struct hlist_head *ndst = xfrm_hash_alloc(nsize);
 513         int i;
 514
 515         if (!ndst)
 516                 return;
 517
 518         write_lock_bh(&xfrm_policy_lock);
 519
 520         for (i = hmask; i >= 0; i--)
 521                 xfrm_dst_hash_transfer(odst + i, ndst, nhashmask);
 522
 523         xfrm_policy_bydst[dir].table = ndst;
 524         xfrm_policy_bydst[dir].hmask = nhashmask;
 525
 526         write_unlock_bh(&xfrm_policy_lock);
 527
 528         xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
 529 }
 530
 531 static void xfrm_byidx_resize(int total)
 532 {
 533         unsigned int hmask = xfrm_idx_hmask;
 534         unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 535         unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
 536         struct hlist_head *oidx = xfrm_policy_byidx;
 537         struct hlist_head *nidx = xfrm_hash_alloc(nsize);
 538         int i;
 539
 540         if (!nidx)
 541                 return;
 542
 543         write_lock_bh(&xfrm_policy_lock);
 544
 545         for (i = hmask; i >= 0; i--)
 546                 xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
 547
 548         xfrm_policy_byidx = nidx;
 549         xfrm_idx_hmask = nhashmask;
 550
 551         write_unlock_bh(&xfrm_policy_lock);
 552
 553         xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
 554 }
 555
 556 static inline int xfrm_bydst_should_resize(int dir, int *total)
 557 {
 558         unsigned int cnt = xfrm_policy_count[dir];
 559         unsigned int hmask = xfrm_policy_bydst[dir].hmask;
 560
 561         if (total)
 562                 *total += cnt;
 563
 564         if ((hmask + 1) < xfrm_policy_hashmax &&
 565             cnt > hmask)
 566                 return 1;
 567
 568         return 0;
 569 }
 570
 571 static inline int xfrm_byidx_should_resize(int total)
 572 {
 573         unsigned int hmask = xfrm_idx_hmask;
 574
 575         if ((hmask + 1) < xfrm_policy_hashmax &&
 576             total > hmask)
 577                 return 1;
 578
 579         return 0;
 580 }
 581
 582 static DEFINE_MUTEX(hash_resize_mutex);
 583
 584 static void xfrm_hash_resize(struct work_struct *__unused)
 585 {
 586         int dir, total;
 587
 588         mutex_lock(&hash_resize_mutex);
 589
 590         total = 0;
 591         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
 592                 if (xfrm_bydst_should_resize(dir, &total))
 593                         xfrm_bydst_resize(dir);
 594         }
 595         if (xfrm_byidx_should_resize(total))
 596                 xfrm_byidx_resize(total);
 597
 598         mutex_unlock(&hash_resize_mutex);
 599 }
 600
 601 static DECLARE_WORK(xfrm_hash_work, xfrm_hash_resize);
 602
 603 /* Generate new index... KAME seems to generate them ordered by cost
 604  * of an absolute inpredictability of ordering of rules. This will not pass. */
 605 static u32 xfrm_gen_index(u8 type, int dir)
 606 {
 607         static u32 idx_generator;
 608
 609         for (;;) {
 610                 struct hlist_node *entry;
 611                 struct hlist_head *list;
 612                 struct xfrm_policy *p;
 613                 u32 idx;
 614                 int found;
 615
 616                 idx = (idx_generator | dir);
 617                 idx_generator += 8;
 618                 if (idx == 0)
 619                         idx = 8;
 620                 list = xfrm_policy_byidx + idx_hash(idx);
 621                 found = 0;
 622                 hlist_for_each_entry(p, entry, list, byidx) {
 623                         if (p->index == idx) {
 624                                 found = 1;
 625                                 break;
 626                         }
 627                 }
 628                 if (!found)
 629                         return idx;
 630         }
 631 }
 632
 633 static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2)
 634 {
 635         u32 *p1 = (u32 *) s1;
 636         u32 *p2 = (u32 *) s2;
 637         int len = sizeof(struct xfrm_selector) / sizeof(u32);
 638         int i;
 639
 640         for (i = 0; i < len; i++) {
 641                 if (p1[i] != p2[i])
 642                         return 1;
 643         }
 644
 645         return 0;
 646 }
 647
 648 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 649 {
 650         struct xfrm_policy *pol;
 651         struct xfrm_policy *delpol;
 652         struct hlist_head *chain;
 653         struct hlist_node *entry, *newpos;
 654         struct dst_entry *gc_list;
 655
 656         write_lock_bh(&xfrm_policy_lock);
 657         chain = policy_hash_bysel(&policy->selector, policy->family, dir);
 658         delpol = NULL;
 659         newpos = NULL;
 660         hlist_for_each_entry(pol, entry, chain, bydst) {
 661                 if (pol->type == policy->type &&
 662                     !selector_cmp(&pol->selector, &policy->selector) &&
 663                     xfrm_sec_ctx_match(pol->security, policy->security) &&
 664                     !WARN_ON(delpol)) {
 665                         if (excl) {
 666                                 write_unlock_bh(&xfrm_policy_lock);
 667                                 return -EEXIST;
 668                         }
 669                         delpol = pol;
 670                         if (policy->priority > pol->priority)
 671                                 continue;
 672                 } else if (policy->priority >= pol->priority) {
 673                         newpos = &pol->bydst;
 674                         continue;
 675                 }
 676                 if (delpol)
 677                         break;
 678         }
 679         if (newpos)
 680                 hlist_add_after(newpos, &policy->bydst);
 681         else
 682                 hlist_add_head(&policy->bydst, chain);
 683         xfrm_pol_hold(policy);
 684         xfrm_policy_count[dir]++;
 685         atomic_inc(&flow_cache_genid);
 686         if (delpol) {
 687                 hlist_del(&delpol->bydst);
 688                 hlist_del(&delpol->byidx);
 689                 xfrm_policy_count[dir]--;
 690         }
 691         policy->index = delpol ? delpol->index : xfrm_gen_index(policy->type, dir);
 692         hlist_add_head(&policy->byidx, xfrm_policy_byidx+idx_hash(policy->index));
 693         policy->curlft.add_time = get_seconds();
 694         policy->curlft.use_time = 0;
 695         if (!mod_timer(&policy->timer, jiffies + HZ))
 696                 xfrm_pol_hold(policy);
 697         write_unlock_bh(&xfrm_policy_lock);
 698
 699         if (delpol)
 700                 xfrm_policy_kill(delpol);
 701         else if (xfrm_bydst_should_resize(dir, NULL))
 702                 schedule_work(&xfrm_hash_work);
 703
 704         read_lock_bh(&xfrm_policy_lock);
 705         gc_list = NULL;
 706         entry = &policy->bydst;
 707         hlist_for_each_entry_continue(policy, entry, bydst) {
 708                 struct dst_entry *dst;
 709
 710                 write_lock(&policy->lock);
 711                 dst = policy->bundles;
 712                 if (dst) {
 713                         struct dst_entry *tail = dst;
 714                         while (tail->next)
 715                                 tail = tail->next;
 716                         tail->next = gc_list;
 717                         gc_list = dst;
 718
 719                         policy->bundles = NULL;
 720                 }
 721                 write_unlock(&policy->lock);
 722         }
 723         read_unlock_bh(&xfrm_policy_lock);
 724
 725         while (gc_list) {
 726                 struct dst_entry *dst = gc_list;
 727
 728                 gc_list = dst->next;
 729                 dst_free(dst);
 730         }
 731
 732         return 0;
 733 }
 734 EXPORT_SYMBOL(xfrm_policy_insert);
 735
 736 struct xfrm_policy *xfrm_policy_bysel_ctx(u8 type, int dir,
 737                                           struct xfrm_selector *sel,
 738                                           struct xfrm_sec_ctx *ctx, int delete,
 739                                           int *err)
 740 {
 741         struct xfrm_policy *pol, *ret;
 742         struct hlist_head *chain;
 743         struct hlist_node *entry;
 744
 745         *err = 0;
 746         write_lock_bh(&xfrm_policy_lock);
 747         chain = policy_hash_bysel(sel, sel->family, dir);
 748         ret = NULL;
 749         hlist_for_each_entry(pol, entry, chain, bydst) {
 750                 if (pol->type == type &&
 751                     !selector_cmp(sel, &pol->selector) &&
 752                     xfrm_sec_ctx_match(ctx, pol->security)) {
 753                         xfrm_pol_hold(pol);
 754                         if (delete) {
 755                                 *err = security_xfrm_policy_delete(pol);
 756                                 if (*err) {
 757                                         write_unlock_bh(&xfrm_policy_lock);
 758                                         return pol;
 759                                 }
 760                                 hlist_del(&pol->bydst);
 761                                 hlist_del(&pol->byidx);
 762                                 xfrm_policy_count[dir]--;
 763                         }
 764                         ret = pol;
 765                         break;
 766                 }
 767         }
 768         write_unlock_bh(&xfrm_policy_lock);
 769
 770         if (ret && delete) {
 771                 atomic_inc(&flow_cache_genid);
 772                 xfrm_policy_kill(ret);
 773         }
 774         return ret;
 775 }
 776 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
 777
 778 struct xfrm_policy *xfrm_policy_byid(u8 type, int dir, u32 id, int delete,
 779                                      int *err)
 780 {
 781         struct xfrm_policy *pol, *ret;
 782         struct hlist_head *chain;
 783         struct hlist_node *entry;
 784
 785         *err = 0;
 786         write_lock_bh(&xfrm_policy_lock);
 787         chain = xfrm_policy_byidx + idx_hash(id);
 788         ret = NULL;
 789         hlist_for_each_entry(pol, entry, chain, byidx) {
 790                 if (pol->type == type && pol->index == id) {
 791                         xfrm_pol_hold(pol);
 792                         if (delete) {
 793                                 *err = security_xfrm_policy_delete(pol);
 794                                 if (*err) {
 795                                         write_unlock_bh(&xfrm_policy_lock);
 796                                         return pol;
 797                                 }
 798                                 hlist_del(&pol->bydst);
 799                                 hlist_del(&pol->byidx);
 800                                 xfrm_policy_count[dir]--;
 801                         }
 802                         ret = pol;
 803                         break;
 804                 }
 805         }
 806         write_unlock_bh(&xfrm_policy_lock);
 807
 808         if (ret && delete) {
 809                 atomic_inc(&flow_cache_genid);
 810                 xfrm_policy_kill(ret);
 811         }
 812         return ret;
 813 }
 814 EXPORT_SYMBOL(xfrm_policy_byid);
 815
 816 void xfrm_policy_flush(u8 type, struct xfrm_audit *audit_info)
 817 {
 818         int dir;
 819
 820         write_lock_bh(&xfrm_policy_lock);
 821         for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
 822                 struct xfrm_policy *pol;
 823                 struct hlist_node *entry;
 824                 int i, killed;
 825
 826                 killed = 0;
 827         again1:
 828                 hlist_for_each_entry(pol, entry,
 829                                      &xfrm_policy_inexact[dir], bydst) {
 830                         if (pol->type != type)
 831                                 continue;
 832                         hlist_del(&pol->bydst);
 833                         hlist_del(&pol->byidx);
 834                         write_unlock_bh(&xfrm_policy_lock);
 835
 836                         xfrm_audit_log(audit_info->loginuid, audit_info->secid,
 837                                        AUDIT_MAC_IPSEC_DELSPD, 1, pol, NULL);
 838
 839                         xfrm_policy_kill(pol);
 840                         killed++;
 841
 842                         write_lock_bh(&xfrm_policy_lock);
 843                         goto again1;
 844                 }
 845
 846                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
 847         again2:
 848                         hlist_for_each_entry(pol, entry,
 849                                              xfrm_policy_bydst[dir].table + i,
 850                                              bydst) {
 851                                 if (pol->type != type)
 852                                         continue;
 853                                 hlist_del(&pol->bydst);
 854                                 hlist_del(&pol->byidx);
 855                                 write_unlock_bh(&xfrm_policy_lock);
 856
 857                                 xfrm_audit_log(audit_info->loginuid,
 858                                                audit_info->secid,
 859                                                AUDIT_MAC_IPSEC_DELSPD, 1,
 860                                                pol, NULL);
 861
 862                                 xfrm_policy_kill(pol);
 863                                 killed++;
 864
 865                                 write_lock_bh(&xfrm_policy_lock);
 866                                 goto again2;
 867                         }
 868                 }
 869
 870                 xfrm_policy_count[dir] -= killed;
 871         }
 872         atomic_inc(&flow_cache_genid);
 873         write_unlock_bh(&xfrm_policy_lock);
 874 }
 875 EXPORT_SYMBOL(xfrm_policy_flush);
 876
 877 int xfrm_policy_walk(u8 type, int (*func)(struct xfrm_policy *, int, int, void*),
 878                      void *data)
 879 {
 880         struct xfrm_policy *pol, *last = NULL;
 881         struct hlist_node *entry;
 882         int dir, last_dir = 0, count, error;
 883
 884         read_lock_bh(&xfrm_policy_lock);
 885         count = 0;
 886
 887         for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) {
 888                 struct hlist_head *table = xfrm_policy_bydst[dir].table;
 889                 int i;
 890
 891                 hlist_for_each_entry(pol, entry,
 892                                      &xfrm_policy_inexact[dir], bydst) {
 893                         if (pol->type != type)
 894                                 continue;
 895                         if (last) {
 896                                 error = func(last, last_dir % XFRM_POLICY_MAX,
 897                                              count, data);
 898                                 if (error)
 899                                         goto out;
 900                         }
 901                         last = pol;
 902                         last_dir = dir;
 903                         count++;
 904                 }
 905                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
 906                         hlist_for_each_entry(pol, entry, table + i, bydst) {
 907                                 if (pol->type != type)
 908                                         continue;
 909                                 if (last) {
 910                                         error = func(last, last_dir % XFRM_POLICY_MAX,
 911                                                      count, data);
 912                                         if (error)
 913                                                 goto out;
 914                                 }
 915                                 last = pol;
 916                                 last_dir = dir;
 917                                 count++;
 918                         }
 919                 }
 920         }
 921         if (count == 0) {
 922                 error = -ENOENT;
 923                 goto out;
 924         }
 925         error = func(last, last_dir % XFRM_POLICY_MAX, 0, data);
 926 out:
 927         read_unlock_bh(&xfrm_policy_lock);
 928         return error;
 929 }
 930 EXPORT_SYMBOL(xfrm_policy_walk);
 931
 932 /*
 933  * Find policy to apply to this flow.
 934  *
 935  * Returns 0 if policy found, else an -errno.
 936  */
 937 static int xfrm_policy_match(struct xfrm_policy *pol, struct flowi *fl,
 938                              u8 type, u16 family, int dir)
 939 {
 940         struct xfrm_selector *sel = &pol->selector;
 941         int match, ret = -ESRCH;
 942
 943         if (pol->family != family ||
 944             pol->type != type)
 945                 return ret;
 946
 947         match = xfrm_selector_match(sel, fl, family);
 948         if (match)
 949                 ret = security_xfrm_policy_lookup(pol, fl->secid, dir);
 950
 951         return ret;
 952 }
 953
 954 static struct xfrm_policy *xfrm_policy_lookup_bytype(u8 type, struct flowi *fl,
 955                                                      u16 family, u8 dir)
 956 {
 957         int err;
 958         struct xfrm_policy *pol, *ret;
 959         xfrm_address_t *daddr, *saddr;
 960         struct hlist_node *entry;
 961         struct hlist_head *chain;
 962         u32 priority = ~0U;
 963
 964         daddr = xfrm_flowi_daddr(fl, family);
 965         saddr = xfrm_flowi_saddr(fl, family);
 966         if (unlikely(!daddr || !saddr))
 967                 return NULL;
 968
 969         read_lock_bh(&xfrm_policy_lock);
 970         chain = policy_hash_direct(daddr, saddr, family, dir);
 971         ret = NULL;
 972         hlist_for_each_entry(pol, entry, chain, bydst) {
 973                 err = xfrm_policy_match(pol, fl, type, family, dir);
 974                 if (err) {
 975                         if (err == -ESRCH)
 976                                 continue;
 977                         else {
 978                                 ret = ERR_PTR(err);
 979                                 goto fail;
 980                         }
 981                 } else {
 982                         ret = pol;
 983                         priority = ret->priority;
 984                         break;
 985                 }
 986         }
 987         chain = &xfrm_policy_inexact[dir];
 988         hlist_for_each_entry(pol, entry, chain, bydst) {
 989                 err = xfrm_policy_match(pol, fl, type, family, dir);
 990                 if (err) {
 991                         if (err == -ESRCH)
 992                                 continue;
 993                         else {
 994                                 ret = ERR_PTR(err);
 995                                 goto fail;
 996                         }
 997                 } else if (pol->priority < priority) {
 998                         ret = pol;
 999                         break;
1000                 }
1001         }
1002         if (ret)
1003                 xfrm_pol_hold(ret);
1004 fail:
1005         read_unlock_bh(&xfrm_policy_lock);
1006
1007         return ret;
1008 }
1009
1010 static int xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
1011                                void **objp, atomic_t **obj_refp)
1012 {
1013         struct xfrm_policy *pol;
1014         int err = 0;
1015
1016 #ifdef CONFIG_XFRM_SUB_POLICY
1017         pol = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_SUB, fl, family, dir);
1018         if (IS_ERR(pol)) {
1019                 err = PTR_ERR(pol);
1020                 pol = NULL;
1021         }
1022         if (pol || err)
1023                 goto end;
1024 #endif
1025         pol = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN, fl, family, dir);
1026         if (IS_ERR(pol)) {
1027                 err = PTR_ERR(pol);
1028                 pol = NULL;
1029         }
1030 #ifdef CONFIG_XFRM_SUB_POLICY
1031 end:
1032 #endif
1033         if ((*objp = (void *) pol) != NULL)
1034                 *obj_refp = &pol->refcnt;
1035         return err;
1036 }
1037
1038 static inline int policy_to_flow_dir(int dir)
1039 {
1040         if (XFRM_POLICY_IN == FLOW_DIR_IN &&
1041             XFRM_POLICY_OUT == FLOW_DIR_OUT &&
1042             XFRM_POLICY_FWD == FLOW_DIR_FWD)
1043                 return dir;
1044         switch (dir) {
1045         default:
1046         case XFRM_POLICY_IN:
1047                 return FLOW_DIR_IN;
1048         case XFRM_POLICY_OUT:
1049                 return FLOW_DIR_OUT;
1050         case XFRM_POLICY_FWD:
1051                 return FLOW_DIR_FWD;
1052         }
1053 }
1054
1055 static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl)
1056 {
1057         struct xfrm_policy *pol;
1058
1059         read_lock_bh(&xfrm_policy_lock);
1060         if ((pol = sk->sk_policy[dir]) != NULL) {
1061                 int match = xfrm_selector_match(&pol->selector, fl,
1062                                                 sk->sk_family);
1063                 int err = 0;
1064
1065                 if (match) {
1066                         err = security_xfrm_policy_lookup(pol, fl->secid,
1067                                         policy_to_flow_dir(dir));
1068                         if (!err)
1069                                 xfrm_pol_hold(pol);
1070                         else if (err == -ESRCH)
1071                                 pol = NULL;
1072                         else
1073                                 pol = ERR_PTR(err);
1074                 } else
1075                         pol = NULL;
1076         }
1077         read_unlock_bh(&xfrm_policy_lock);
1078         return pol;
1079 }
1080
1081 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
1082 {
1083         struct hlist_head *chain = policy_hash_bysel(&pol->selector,
1084                                                      pol->family, dir);
1085
1086         hlist_add_head(&pol->bydst, chain);
1087         hlist_add_head(&pol->byidx, xfrm_policy_byidx+idx_hash(pol->index));
1088         xfrm_policy_count[dir]++;
1089         xfrm_pol_hold(pol);
1090
1091         if (xfrm_bydst_should_resize(dir, NULL))
1092                 schedule_work(&xfrm_hash_work);
1093 }
1094
1095 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
1096                                                 int dir)
1097 {
1098         if (hlist_unhashed(&pol->bydst))
1099                 return NULL;
1100
1101         hlist_del(&pol->bydst);
1102         hlist_del(&pol->byidx);
1103         xfrm_policy_count[dir]--;
1104
1105         return pol;
1106 }
1107
1108 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
1109 {
1110         write_lock_bh(&xfrm_policy_lock);
1111         pol = __xfrm_policy_unlink(pol, dir);
1112         write_unlock_bh(&xfrm_policy_lock);
1113         if (pol) {
1114                 if (dir < XFRM_POLICY_MAX)
1115                         atomic_inc(&flow_cache_genid);
1116                 xfrm_policy_kill(pol);
1117                 return 0;
1118         }
1119         return -ENOENT;
1120 }
1121 EXPORT_SYMBOL(xfrm_policy_delete);
1122
1123 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
1124 {
1125         struct xfrm_policy *old_pol;
1126
1127 #ifdef CONFIG_XFRM_SUB_POLICY
1128         if (pol && pol->type != XFRM_POLICY_TYPE_MAIN)
1129                 return -EINVAL;
1130 #endif
1131
1132         write_lock_bh(&xfrm_policy_lock);
1133         old_pol = sk->sk_policy[dir];
1134         sk->sk_policy[dir] = pol;
1135         if (pol) {
1136                 pol->curlft.add_time = get_seconds();
1137                 pol->index = xfrm_gen_index(pol->type, XFRM_POLICY_MAX+dir);
1138                 __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
1139         }
1140         if (old_pol)
1141                 __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
1142         write_unlock_bh(&xfrm_policy_lock);
1143
1144         if (old_pol) {
1145                 xfrm_policy_kill(old_pol);
1146         }
1147         return 0;
1148 }
1149
1150 static struct xfrm_policy *clone_policy(struct xfrm_policy *old, int dir)
1151 {
1152         struct xfrm_policy *newp = xfrm_policy_alloc(GFP_ATOMIC);
1153
1154         if (newp) {
1155                 newp->selector = old->selector;
1156                 if (security_xfrm_policy_clone(old, newp)) {
1157                         kfree(newp);
1158                         return NULL;  /* ENOMEM */
1159                 }
1160                 newp->lft = old->lft;
1161                 newp->curlft = old->curlft;
1162                 newp->action = old->action;
1163                 newp->flags = old->flags;
1164                 newp->xfrm_nr = old->xfrm_nr;
1165                 newp->index = old->index;
1166                 newp->type = old->type;
1167                 memcpy(newp->xfrm_vec, old->xfrm_vec,
1168                        newp->xfrm_nr*sizeof(struct xfrm_tmpl));
1169                 write_lock_bh(&xfrm_policy_lock);
1170                 __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir);
1171                 write_unlock_bh(&xfrm_policy_lock);
1172                 xfrm_pol_put(newp);
1173         }
1174         return newp;
1175 }
1176
1177 int __xfrm_sk_clone_policy(struct sock *sk)
1178 {
1179         struct xfrm_policy *p0 = sk->sk_policy[0],
1180                            *p1 = sk->sk_policy[1];
1181
1182         sk->sk_policy[0] = sk->sk_policy[1] = NULL;
1183         if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL)
1184                 return -ENOMEM;
1185         if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL)
1186                 return -ENOMEM;
1187         return 0;
1188 }
1189
1190 static int
1191 xfrm_get_saddr(xfrm_address_t *local, xfrm_address_t *remote,
1192                unsigned short family)
1193 {
1194         int err;
1195         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1196
1197         if (unlikely(afinfo == NULL))
1198                 return -EINVAL;
1199         err = afinfo->get_saddr(local, remote);
1200         xfrm_policy_put_afinfo(afinfo);
1201         return err;
1202 }
1203
1204 /* Resolve list of templates for the flow, given policy. */
1205
1206 static int
1207 xfrm_tmpl_resolve_one(struct xfrm_policy *policy, struct flowi *fl,
1208                       struct xfrm_state **xfrm,
1209                       unsigned short family)
1210 {
1211         int nx;
1212         int i, error;
1213         xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
1214         xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
1215         xfrm_address_t tmp;
1216
1217         for (nx=0, i = 0; i < policy->xfrm_nr; i++) {
1218                 struct xfrm_state *x;
1219                 xfrm_address_t *remote = daddr;
1220                 xfrm_address_t *local  = saddr;
1221                 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
1222
1223                 if (tmpl->mode == XFRM_MODE_TUNNEL) {
1224                         remote = &tmpl->id.daddr;
1225                         local = &tmpl->saddr;
1226                         family = tmpl->encap_family;
1227                         if (xfrm_addr_any(local, family)) {
1228                                 error = xfrm_get_saddr(&tmp, remote, family);
1229                                 if (error)
1230                                         goto fail;
1231                                 local = &tmp;
1232                         }
1233                 }
1234
1235                 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);
1236
1237                 if (x && x->km.state == XFRM_STATE_VALID) {
1238                         xfrm[nx++] = x;
1239                         daddr = remote;
1240                         saddr = local;
1241                         continue;
1242                 }
1243                 if (x) {
1244                         error = (x->km.state == XFRM_STATE_ERROR ?
1245                                  -EINVAL : -EAGAIN);
1246                         xfrm_state_put(x);
1247                 }
1248
1249                 if (!tmpl->optional)
1250                         goto fail;
1251         }
1252         return nx;
1253
1254 fail:
1255         for (nx--; nx>=0; nx--)
1256                 xfrm_state_put(xfrm[nx]);
1257         return error;
1258 }
1259
1260 static int
1261 xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, struct flowi *fl,
1262                   struct xfrm_state **xfrm,
1263                   unsigned short family)
1264 {
1265         struct xfrm_state *tp[XFRM_MAX_DEPTH];
1266         struct xfrm_state **tpp = (npols > 1) ? tp : xfrm;
1267         int cnx = 0;
1268         int error;
1269         int ret;
1270         int i;
1271
1272         for (i = 0; i < npols; i++) {
1273                 if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) {
1274                         error = -ENOBUFS;
1275                         goto fail;
1276                 }
1277
1278                 ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family);
1279                 if (ret < 0) {
1280                         error = ret;
1281                         goto fail;
1282                 } else
1283                         cnx += ret;
1284         }
1285
1286         /* found states are sorted for outbound processing */
1287         if (npols > 1)
1288                 xfrm_state_sort(xfrm, tpp, cnx, family);
1289
1290         return cnx;
1291
1292  fail:
1293         for (cnx--; cnx>=0; cnx--)
1294                 xfrm_state_put(tpp[cnx]);
1295         return error;
1296
1297 }
1298
1299 /* Check that the bundle accepts the flow and its components are
1300  * still valid.
1301  */
1302
1303 static struct dst_entry *
1304 xfrm_find_bundle(struct flowi *fl, struct xfrm_policy *policy, unsigned short family)
1305 {
1306         struct dst_entry *x;
1307         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1308         if (unlikely(afinfo == NULL))
1309                 return ERR_PTR(-EINVAL);
1310         x = afinfo->find_bundle(fl, policy);
1311         xfrm_policy_put_afinfo(afinfo);
1312         return x;
1313 }
1314
1315 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
1316  * all the metrics... Shortly, bundle a bundle.
1317  */
1318
1319 static int
1320 xfrm_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
1321                    struct flowi *fl, struct dst_entry **dst_p,
1322                    unsigned short family)
1323 {
1324         int err;
1325         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1326         if (unlikely(afinfo == NULL))
1327                 return -EINVAL;
1328         err = afinfo->bundle_create(policy, xfrm, nx, fl, dst_p);
1329         xfrm_policy_put_afinfo(afinfo);
1330         return err;
1331 }
1332
1333
1334 static int stale_bundle(struct dst_entry *dst);
1335
1336 /* Main function: finds/creates a bundle for given flow.
1337  *
1338  * At the moment we eat a raw IP route. Mostly to speed up lookups
1339  * on interfaces with disabled IPsec.
1340  */
1341 int xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
1342                 struct sock *sk, int flags)
1343 {
1344         struct xfrm_policy *policy;
1345         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1346         int npols;
1347         int pol_dead;
1348         int xfrm_nr;
1349         int pi;
1350         struct xfrm_state *xfrm[XFRM_MAX_DEPTH];
1351         struct dst_entry *dst, *dst_orig = *dst_p;
1352         int nx = 0;
1353         int err;
1354         u32 genid;
1355         u16 family;
1356         u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
1357
1358 restart:
1359         genid = atomic_read(&flow_cache_genid);
1360         policy = NULL;
1361         for (pi = 0; pi < ARRAY_SIZE(pols); pi++)
1362                 pols[pi] = NULL;
1363         npols = 0;
1364         pol_dead = 0;
1365         xfrm_nr = 0;
1366
1367         if (sk && sk->sk_policy[1]) {
1368                 policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
1369                 if (IS_ERR(policy))
1370                         return PTR_ERR(policy);
1371         }
1372
1373         if (!policy) {
1374                 /* To accelerate a bit...  */
1375                 if ((dst_orig->flags & DST_NOXFRM) ||
1376                     !xfrm_policy_count[XFRM_POLICY_OUT])
1377                         return 0;
1378
1379                 policy = flow_cache_lookup(fl, dst_orig->ops->family,
1380                                            dir, xfrm_policy_lookup);
1381                 if (IS_ERR(policy))
1382                         return PTR_ERR(policy);
1383         }
1384
1385         if (!policy)
1386                 return 0;
1387
1388         family = dst_orig->ops->family;
1389         policy->curlft.use_time = get_seconds();
1390         pols[0] = policy;
1391         npols ++;
1392         xfrm_nr += pols[0]->xfrm_nr;
1393
1394         switch (policy->action) {
1395         case XFRM_POLICY_BLOCK:
1396                 /* Prohibit the flow */
1397                 err = -EPERM;
1398                 goto error;
1399
1400         case XFRM_POLICY_ALLOW:
1401 #ifndef CONFIG_XFRM_SUB_POLICY
1402                 if (policy->xfrm_nr == 0) {
1403                         /* Flow passes not transformed. */
1404                         xfrm_pol_put(policy);
1405                         return 0;
1406                 }
1407 #endif
1408
1409                 /* Try to find matching bundle.
1410                  *
1411                  * LATER: help from flow cache. It is optional, this
1412                  * is required only for output policy.
1413                  */
1414                 dst = xfrm_find_bundle(fl, policy, family);
1415                 if (IS_ERR(dst)) {
1416                         err = PTR_ERR(dst);
1417                         goto error;
1418                 }
1419
1420                 if (dst)
1421                         break;
1422
1423 #ifdef CONFIG_XFRM_SUB_POLICY
1424                 if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1425                         pols[1] = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN,
1426                                                             fl, family,
1427                                                             XFRM_POLICY_OUT);
1428                         if (pols[1]) {
1429                                 if (IS_ERR(pols[1])) {
1430                                         err = PTR_ERR(pols[1]);
1431                                         goto error;
1432                                 }
1433                                 if (pols[1]->action == XFRM_POLICY_BLOCK) {
1434                                         err = -EPERM;
1435                                         goto error;
1436                                 }
1437                                 npols ++;
1438                                 xfrm_nr += pols[1]->xfrm_nr;
1439                         }
1440                 }
1441
1442                 /*
1443                  * Because neither flowi nor bundle information knows about
1444                  * transformation template size. On more than one policy usage
1445                  * we can realize whether all of them is bypass or not after
1446                  * they are searched. See above not-transformed bypass
1447                  * is surrounded by non-sub policy configuration, too.
1448                  */
1449                 if (xfrm_nr == 0) {
1450                         /* Flow passes not transformed. */
1451                         xfrm_pols_put(pols, npols);
1452                         return 0;
1453                 }
1454
1455 #endif
1456                 nx = xfrm_tmpl_resolve(pols, npols, fl, xfrm, family);
1457
1458                 if (unlikely(nx<0)) {
1459                         err = nx;
1460                         if (err == -EAGAIN && flags) {
1461                                 DECLARE_WAITQUEUE(wait, current);
1462
1463                                 add_wait_queue(&km_waitq, &wait);
1464                                 set_current_state(TASK_INTERRUPTIBLE);
1465                                 schedule();
1466                                 set_current_state(TASK_RUNNING);
1467                                 remove_wait_queue(&km_waitq, &wait);
1468
1469                                 nx = xfrm_tmpl_resolve(pols, npols, fl, xfrm, family);
1470
1471                                 if (nx == -EAGAIN && signal_pending(current)) {
1472                                         err = -ERESTART;
1473                                         goto error;
1474                                 }
1475                                 if (nx == -EAGAIN ||
1476                                     genid != atomic_read(&flow_cache_genid)) {
1477                                         xfrm_pols_put(pols, npols);
1478                                         goto restart;
1479                                 }
1480                                 err = nx;
1481                         }
1482                         if (err < 0)
1483                                 goto error;
1484                 }
1485                 if (nx == 0) {
1486                         /* Flow passes not transformed. */
1487                         xfrm_pols_put(pols, npols);
1488                         return 0;
1489                 }
1490
1491                 dst = dst_orig;
1492                 err = xfrm_bundle_create(policy, xfrm, nx, fl, &dst, family);
1493
1494                 if (unlikely(err)) {
1495                         int i;
1496                         for (i=0; i<nx; i++)
1497                                 xfrm_state_put(xfrm[i]);
1498                         goto error;
1499                 }
1500
1501                 for (pi = 0; pi < npols; pi++) {
1502                         read_lock_bh(&pols[pi]->lock);
1503                         pol_dead |= pols[pi]->dead;
1504                         read_unlock_bh(&pols[pi]->lock);
1505                 }
1506
1507                 write_lock_bh(&policy->lock);
1508                 if (unlikely(pol_dead || stale_bundle(dst))) {
1509                         /* Wow! While we worked on resolving, this
1510                          * policy has gone. Retry. It is not paranoia,
1511                          * we just cannot enlist new bundle to dead object.
1512                          * We can't enlist stable bundles either.
1513                          */
1514                         write_unlock_bh(&policy->lock);
1515                         if (dst)
1516                                 dst_free(dst);
1517
1518                         err = -EHOSTUNREACH;
1519                         goto error;
1520                 }
1521                 dst->next = policy->bundles;
1522                 policy->bundles = dst;
1523                 dst_hold(dst);
1524                 write_unlock_bh(&policy->lock);
1525         }
1526         *dst_p = dst;
1527         dst_release(dst_orig);
1528         xfrm_pols_put(pols, npols);
1529         return 0;
1530
1531 error:
1532         dst_release(dst_orig);
1533         xfrm_pols_put(pols, npols);
1534         *dst_p = NULL;
1535         return err;
1536 }
1537 EXPORT_SYMBOL(xfrm_lookup);
1538
1539 static inline int
1540 xfrm_secpath_reject(int idx, struct sk_buff *skb, struct flowi *fl)
1541 {
1542         struct xfrm_state *x;
1543         int err;
1544
1545         if (!skb->sp || idx < 0 || idx >= skb->sp->len)
1546                 return 0;
1547         x = skb->sp->xvec[idx];
1548         if (!x->type->reject)
1549                 return 0;
1550         xfrm_state_hold(x);
1551         err = x->type->reject(x, skb, fl);
1552         xfrm_state_put(x);
1553         return err;
1554 }
1555
1556 /* When skb is transformed back to its "native" form, we have to
1557  * check policy restrictions. At the moment we make this in maximally
1558  * stupid way. Shame on me. :-) Of course, connected sockets must
1559  * have policy cached at them.
1560  */
1561
1562 static inline int
1563 xfrm_state_ok(struct xfrm_tmpl *tmpl, struct xfrm_state *x,
1564               unsigned short family)
1565 {
1566         if (xfrm_state_kern(x))
1567                 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family);
1568         return  x->id.proto == tmpl->id.proto &&
1569                 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) &&
1570                 (x->props.reqid == tmpl->reqid || !tmpl->reqid) &&
1571                 x->props.mode == tmpl->mode &&
1572                 ((tmpl->aalgos & (1<<x->props.aalgo)) ||
1573                  !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) &&
1574                 !(x->props.mode != XFRM_MODE_TRANSPORT &&
1575                   xfrm_state_addr_cmp(tmpl, x, family));
1576 }
1577
1578 /*
1579  * 0 or more than 0 is returned when validation is succeeded (either bypass
1580  * because of optional transport mode, or next index of the mathced secpath
1581  * state with the template.
1582  * -1 is returned when no matching template is found.
1583  * Otherwise "-2 - errored_index" is returned.
1584  */
1585 static inline int
1586 xfrm_policy_ok(struct xfrm_tmpl *tmpl, struct sec_path *sp, int start,
1587                unsigned short family)
1588 {
1589         int idx = start;
1590
1591         if (tmpl->optional) {
1592                 if (tmpl->mode == XFRM_MODE_TRANSPORT)
1593                         return start;
1594         } else
1595                 start = -1;
1596         for (; idx < sp->len; idx++) {
1597                 if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
1598                         return ++idx;
1599                 if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
1600                         if (start == -1)
1601                                 start = -2-idx;
1602                         break;
1603                 }
1604         }
1605         return start;
1606 }
1607
1608 int
1609 xfrm_decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family)
1610 {
1611         struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
1612         int err;
1613
1614         if (unlikely(afinfo == NULL))
1615                 return -EAFNOSUPPORT;
1616
1617         afinfo->decode_session(skb, fl);
1618         err = security_xfrm_decode_session(skb, &fl->secid);
1619         xfrm_policy_put_afinfo(afinfo);
1620         return err;
1621 }
1622 EXPORT_SYMBOL(xfrm_decode_session);
1623
1624 static inline int secpath_has_nontransport(struct sec_path *sp, int k, int *idxp)
1625 {
1626         for (; k < sp->len; k++) {
1627                 if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
1628                         *idxp = k;
1629                         return 1;
1630                 }
1631         }
1632
1633         return 0;
1634 }
1635
1636 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
1637                         unsigned short family)
1638 {
1639         struct xfrm_policy *pol;
1640         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
1641         int npols = 0;
1642         int xfrm_nr;
1643         int pi;
1644         struct flowi fl;
1645         u8 fl_dir = policy_to_flow_dir(dir);
1646         int xerr_idx = -1;
1647
1648         if (xfrm_decode_session(skb, &fl, family) < 0)
1649                 return 0;
1650         nf_nat_decode_session(skb, &fl, family);
1651
1652         /* First, check used SA against their selectors. */
1653         if (skb->sp) {
1654                 int i;
1655
1656                 for (i=skb->sp->len-1; i>=0; i--) {
1657                         struct xfrm_state *x = skb->sp->xvec[i];
1658                         if (!xfrm_selector_match(&x->sel, &fl, family))
1659                                 return 0;
1660                 }
1661         }
1662
1663         pol = NULL;
1664         if (sk && sk->sk_policy[dir]) {
1665                 pol = xfrm_sk_policy_lookup(sk, dir, &fl);
1666                 if (IS_ERR(pol))
1667                         return 0;
1668         }
1669
1670         if (!pol)
1671                 pol = flow_cache_lookup(&fl, family, fl_dir,
1672                                         xfrm_policy_lookup);
1673
1674         if (IS_ERR(pol))
1675                 return 0;
1676
1677         if (!pol) {
1678                 if (skb->sp && secpath_has_nontransport(skb->sp, 0, &xerr_idx)) {
1679                         xfrm_secpath_reject(xerr_idx, skb, &fl);
1680                         return 0;
1681                 }
1682                 return 1;
1683         }
1684
1685         pol->curlft.use_time = get_seconds();
1686
1687         pols[0] = pol;
1688         npols ++;
1689 #ifdef CONFIG_XFRM_SUB_POLICY
1690         if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) {
1691                 pols[1] = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN,
1692                                                     &fl, family,
1693                                                     XFRM_POLICY_IN);
1694                 if (pols[1]) {
1695                         if (IS_ERR(pols[1]))
1696                                 return 0;
1697                         pols[1]->curlft.use_time = get_seconds();
1698                         npols ++;
1699                 }
1700         }
1701 #endif
1702
1703         if (pol->action == XFRM_POLICY_ALLOW) {
1704                 struct sec_path *sp;
1705                 static struct sec_path dummy;
1706                 struct xfrm_tmpl *tp[XFRM_MAX_DEPTH];
1707                 struct xfrm_tmpl *stp[XFRM_MAX_DEPTH];
1708                 struct xfrm_tmpl **tpp = tp;
1709                 int ti = 0;
1710                 int i, k;
1711
1712                 if ((sp = skb->sp) == NULL)
1713                         sp = &dummy;
1714
1715                 for (pi = 0; pi < npols; pi++) {
1716                         if (pols[pi] != pol &&
1717                             pols[pi]->action != XFRM_POLICY_ALLOW)
1718                                 goto reject;
1719                         if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH)
1720                                 goto reject_error;
1721                         for (i = 0; i < pols[pi]->xfrm_nr; i++)
1722                                 tpp[ti++] = &pols[pi]->xfrm_vec[i];
1723                 }
1724                 xfrm_nr = ti;
1725                 if (npols > 1) {
1726                         xfrm_tmpl_sort(stp, tpp, xfrm_nr, family);
1727                         tpp = stp;
1728                 }
1729
1730                 /* For each tunnel xfrm, find the first matching tmpl.
1731                  * For each tmpl before that, find corresponding xfrm.
1732                  * Order is _important_. Later we will implement
1733                  * some barriers, but at the moment barriers
1734                  * are implied between each two transformations.
1735                  */
1736                 for (i = xfrm_nr-1, k = 0; i >= 0; i--) {
1737                         k = xfrm_policy_ok(tpp[i], sp, k, family);
1738                         if (k < 0) {
1739                                 if (k < -1)
1740                                         /* "-2 - errored_index" returned */
1741                                         xerr_idx = -(2+k);
1742                                 goto reject;
1743                         }
1744                 }
1745
1746                 if (secpath_has_nontransport(sp, k, &xerr_idx))
1747                         goto reject;
1748
1749                 xfrm_pols_put(pols, npols);
1750                 return 1;
1751         }
1752
1753 reject:
1754         xfrm_secpath_reject(xerr_idx, skb, &fl);
1755 reject_error:
1756         xfrm_pols_put(pols, npols);
1757         return 0;
1758 }
1759 EXPORT_SYMBOL(__xfrm_policy_check);
1760
1761 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
1762 {
1763         struct flowi fl;
1764
1765         if (xfrm_decode_session(skb, &fl, family) < 0)
1766                 return 0;
1767
1768         return xfrm_lookup(&skb->dst, &fl, NULL, 0) == 0;
1769 }
1770 EXPORT_SYMBOL(__xfrm_route_forward);
1771
1772 /* Optimize later using cookies and generation ids. */
1773
1774 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
1775 {
1776         /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete
1777          * to "-1" to force all XFRM destinations to get validated by
1778          * dst_ops->check on every use.  We do this because when a
1779          * normal route referenced by an XFRM dst is obsoleted we do
1780          * not go looking around for all parent referencing XFRM dsts
1781          * so that we can invalidate them.  It is just too much work.
1782          * Instead we make the checks here on every use.  For example:
1783          *
1784          *      XFRM dst A --> IPv4 dst X
1785          *
1786          * X is the "xdst->route" of A (X is also the "dst->path" of A
1787          * in this example).  If X is marked obsolete, "A" will not
1788          * notice.  That's what we are validating here via the
1789          * stale_bundle() check.
1790          *
1791          * When a policy's bundle is pruned, we dst_free() the XFRM
1792          * dst which causes it's ->obsolete field to be set to a
1793          * positive non-zero integer.  If an XFRM dst has been pruned
1794          * like this, we want to force a new route lookup.
1795          */
1796         if (dst->obsolete < 0 && !stale_bundle(dst))
1797                 return dst;
1798
1799         return NULL;
1800 }
1801
1802 static int stale_bundle(struct dst_entry *dst)
1803 {
1804         return !xfrm_bundle_ok(NULL, (struct xfrm_dst *)dst, NULL, AF_UNSPEC, 0);
1805 }
1806
1807 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
1808 {
1809         while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
1810                 dst->dev = &loopback_dev;
1811                 dev_hold(&loopback_dev);
1812                 dev_put(dev);
1813         }
1814 }
1815 EXPORT_SYMBOL(xfrm_dst_ifdown);
1816
1817 static void xfrm_link_failure(struct sk_buff *skb)
1818 {
1819         /* Impossible. Such dst must be popped before reaches point of failure. */
1820         return;
1821 }
1822
1823 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)
1824 {
1825         if (dst) {
1826                 if (dst->obsolete) {
1827                         dst_release(dst);
1828                         dst = NULL;
1829                 }
1830         }
1831         return dst;
1832 }
1833
1834 static void prune_one_bundle(struct xfrm_policy *pol, int (*func)(struct dst_entry *), struct dst_entry **gc_list_p)
1835 {
1836         struct dst_entry *dst, **dstp;
1837
1838         write_lock(&pol->lock);
1839         dstp = &pol->bundles;
1840         while ((dst=*dstp) != NULL) {
1841                 if (func(dst)) {
1842                         *dstp = dst->next;
1843                         dst->next = *gc_list_p;
1844                         *gc_list_p = dst;
1845                 } else {
1846                         dstp = &dst->next;
1847                 }
1848         }
1849         write_unlock(&pol->lock);
1850 }
1851
1852 static void xfrm_prune_bundles(int (*func)(struct dst_entry *))
1853 {
1854         struct dst_entry *gc_list = NULL;
1855         int dir;
1856
1857         read_lock_bh(&xfrm_policy_lock);
1858         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
1859                 struct xfrm_policy *pol;
1860                 struct hlist_node *entry;
1861                 struct hlist_head *table;
1862                 int i;
1863
1864                 hlist_for_each_entry(pol, entry,
1865                                      &xfrm_policy_inexact[dir], bydst)
1866                         prune_one_bundle(pol, func, &gc_list);
1867
1868                 table = xfrm_policy_bydst[dir].table;
1869                 for (i = xfrm_policy_bydst[dir].hmask; i >= 0; i--) {
1870                         hlist_for_each_entry(pol, entry, table + i, bydst)
1871                                 prune_one_bundle(pol, func, &gc_list);
1872                 }
1873         }
1874         read_unlock_bh(&xfrm_policy_lock);
1875
1876         while (gc_list) {
1877                 struct dst_entry *dst = gc_list;
1878                 gc_list = dst->next;
1879                 dst_free(dst);
1880         }
1881 }
1882
1883 static int unused_bundle(struct dst_entry *dst)
1884 {
1885         return !atomic_read(&dst->__refcnt);
1886 }
1887
1888 static void __xfrm_garbage_collect(void)
1889 {
1890         xfrm_prune_bundles(unused_bundle);
1891 }
1892
1893 static int xfrm_flush_bundles(void)
1894 {
1895         xfrm_prune_bundles(stale_bundle);
1896         return 0;
1897 }
1898
1899 void xfrm_init_pmtu(struct dst_entry *dst)
1900 {
1901         do {
1902                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1903                 u32 pmtu, route_mtu_cached;
1904
1905                 pmtu = dst_mtu(dst->child);
1906                 xdst->child_mtu_cached = pmtu;
1907
1908                 pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
1909
1910                 route_mtu_cached = dst_mtu(xdst->route);
1911                 xdst->route_mtu_cached = route_mtu_cached;
1912
1913                 if (pmtu > route_mtu_cached)
1914                         pmtu = route_mtu_cached;
1915
1916                 dst->metrics[RTAX_MTU-1] = pmtu;
1917         } while ((dst = dst->next));
1918 }
1919
1920 EXPORT_SYMBOL(xfrm_init_pmtu);
1921
1922 /* Check that the bundle accepts the flow and its components are
1923  * still valid.
1924  */
1925
1926 int xfrm_bundle_ok(struct xfrm_policy *pol, struct xfrm_dst *first,
1927                 struct flowi *fl, int family, int strict)
1928 {
1929         struct dst_entry *dst = &first->u.dst;
1930         struct xfrm_dst *last;
1931         u32 mtu;
1932
1933         if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) ||
1934             (dst->dev && !netif_running(dst->dev)))
1935                 return 0;
1936
1937         last = NULL;
1938
1939         do {
1940                 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1941
1942                 if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family))
1943                         return 0;
1944                 if (fl && pol &&
1945                     !security_xfrm_state_pol_flow_match(dst->xfrm, pol, fl))
1946                         return 0;
1947                 if (dst->xfrm->km.state != XFRM_STATE_VALID)
1948                         return 0;
1949                 if (xdst->genid != dst->xfrm->genid)
1950                         return 0;
1951
1952                 if (strict && fl && dst->xfrm->props.mode != XFRM_MODE_TUNNEL &&
1953                     !xfrm_state_addr_flow_check(dst->xfrm, fl, family))
1954                         return 0;
1955
1956                 mtu = dst_mtu(dst->child);
1957                 if (xdst->child_mtu_cached != mtu) {
1958                         last = xdst;
1959                         xdst->child_mtu_cached = mtu;
1960                 }
1961
1962                 if (!dst_check(xdst->route, xdst->route_cookie))
1963                         return 0;
1964                 mtu = dst_mtu(xdst->route);
1965                 if (xdst->route_mtu_cached != mtu) {
1966                         last = xdst;
1967                         xdst->route_mtu_cached = mtu;
1968                 }
1969
1970                 dst = dst->child;
1971         } while (dst->xfrm);
1972
1973         if (likely(!last))
1974                 return 1;
1975
1976         mtu = last->child_mtu_cached;
1977         for (;;) {
1978                 dst = &last->u.dst;
1979
1980                 mtu = xfrm_state_mtu(dst->xfrm, mtu);
1981                 if (mtu > last->route_mtu_cached)
1982                         mtu = last->route_mtu_cached;
1983                 dst->metrics[RTAX_MTU-1] = mtu;
1984
1985                 if (last == first)
1986                         break;
1987
1988                 last = last->u.next;
1989                 last->child_mtu_cached = mtu;
1990         }
1991
1992         return 1;
1993 }
1994
1995 EXPORT_SYMBOL(xfrm_bundle_ok);
1996
1997 #ifdef CONFIG_AUDITSYSCALL
1998 /* Audit addition and deletion of SAs and ipsec policy */
1999
2000 void xfrm_audit_log(uid_t auid, u32 sid, int type, int result,
2001                     struct xfrm_policy *xp, struct xfrm_state *x)
2002 {
2003
2004         char *secctx;
2005         u32 secctx_len;
2006         struct xfrm_sec_ctx *sctx = NULL;
2007         struct audit_buffer *audit_buf;
2008         int family;
2009         extern int audit_enabled;
2010
2011         if (audit_enabled == 0)
2012                 return;
2013
2014         BUG_ON((type == AUDIT_MAC_IPSEC_ADDSA ||
2015                 type == AUDIT_MAC_IPSEC_DELSA) && !x);
2016         BUG_ON((type == AUDIT_MAC_IPSEC_ADDSPD ||
2017                 type == AUDIT_MAC_IPSEC_DELSPD) && !xp);
2018
2019         audit_buf = audit_log_start(current->audit_context, GFP_ATOMIC, type);
2020         if (audit_buf == NULL)
2021                 return;
2022
2023         switch(type) {
2024         case AUDIT_MAC_IPSEC_ADDSA:
2025                 audit_log_format(audit_buf, "SAD add: auid=%u", auid);
2026                 break;
2027         case AUDIT_MAC_IPSEC_DELSA:
2028                 audit_log_format(audit_buf, "SAD delete: auid=%u", auid);
2029                 break;
2030         case AUDIT_MAC_IPSEC_ADDSPD:
2031                 audit_log_format(audit_buf, "SPD add: auid=%u", auid);
2032                 break;
2033         case AUDIT_MAC_IPSEC_DELSPD:
2034                 audit_log_format(audit_buf, "SPD delete: auid=%u", auid);
2035                 break;
2036         default:
2037                 return;
2038         }
2039
2040         if (sid != 0 &&
2041                 security_secid_to_secctx(sid, &secctx, &secctx_len) == 0)
2042                 audit_log_format(audit_buf, " subj=%s", secctx);
2043         else
2044                 audit_log_task_context(audit_buf);
2045
2046         if (xp) {
2047                 family = xp->selector.family;
2048                 if (xp->security)
2049                         sctx = xp->security;
2050         } else {
2051                 family = x->props.family;
2052                 if (x->security)
2053                         sctx = x->security;
2054         }
2055
2056         if (sctx)
2057                 audit_log_format(audit_buf,
2058                                 " sec_alg=%u sec_doi=%u sec_obj=%s",
2059                                 sctx->ctx_alg, sctx->ctx_doi, sctx->ctx_str);
2060
2061         switch(family) {
2062         case AF_INET:
2063                 {
2064                         struct in_addr saddr, daddr;
2065                         if (xp) {
2066                                 saddr.s_addr = xp->selector.saddr.a4;
2067                                 daddr.s_addr = xp->selector.daddr.a4;
2068                         } else {
2069                                 saddr.s_addr = x->props.saddr.a4;
2070                                 daddr.s_addr = x->id.daddr.a4;
2071                         }
2072                         audit_log_format(audit_buf,
2073                                          " src=%u.%u.%u.%u dst=%u.%u.%u.%u",
2074                                          NIPQUAD(saddr), NIPQUAD(daddr));
2075                 }
2076                         break;
2077         case AF_INET6:
2078                 {
2079                         struct in6_addr saddr6, daddr6;
2080                         if (xp) {
2081                                 memcpy(&saddr6, xp->selector.saddr.a6,
2082                                         sizeof(struct in6_addr));
2083                                 memcpy(&daddr6, xp->selector.daddr.a6,
2084                                         sizeof(struct in6_addr));
2085                         } else {
2086                                 memcpy(&saddr6, x->props.saddr.a6,
2087                                         sizeof(struct in6_addr));
2088                                 memcpy(&daddr6, x->id.daddr.a6,
2089                                         sizeof(struct in6_addr));
2090                         }
2091                         audit_log_format(audit_buf,
2092                                          " src=" NIP6_FMT " dst=" NIP6_FMT,
2093                                          NIP6(saddr6), NIP6(daddr6));
2094                 }
2095                 break;
2096         }
2097
2098         if (x)
2099                 audit_log_format(audit_buf, " spi=%lu(0x%lx) protocol=%s",
2100                                 (unsigned long)ntohl(x->id.spi),
2101                                 (unsigned long)ntohl(x->id.spi),
2102                                 x->id.proto == IPPROTO_AH ? "AH" :
2103                                 (x->id.proto == IPPROTO_ESP ?
2104                                 "ESP" : "IPCOMP"));
2105
2106         audit_log_format(audit_buf, " res=%u", result);
2107         audit_log_end(audit_buf);
2108 }
2109
2110 EXPORT_SYMBOL(xfrm_audit_log);
2111 #endif /* CONFIG_AUDITSYSCALL */
2112
2113 int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
2114 {
2115         int err = 0;
2116         if (unlikely(afinfo == NULL))
2117                 return -EINVAL;
2118         if (unlikely(afinfo->family >= NPROTO))
2119                 return -EAFNOSUPPORT;
2120         write_lock_bh(&xfrm_policy_afinfo_lock);
2121         if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
2122                 err = -ENOBUFS;
2123         else {
2124                 struct dst_ops *dst_ops = afinfo->dst_ops;
2125                 if (likely(dst_ops->kmem_cachep == NULL))
2126                         dst_ops->kmem_cachep = xfrm_dst_cache;
2127                 if (likely(dst_ops->check == NULL))
2128                         dst_ops->check = xfrm_dst_check;
2129                 if (likely(dst_ops->negative_advice == NULL))
2130                         dst_ops->negative_advice = xfrm_negative_advice;
2131                 if (likely(dst_ops->link_failure == NULL))
2132                         dst_ops->link_failure = xfrm_link_failure;
2133                 if (likely(afinfo->garbage_collect == NULL))
2134                         afinfo->garbage_collect = __xfrm_garbage_collect;
2135                 xfrm_policy_afinfo[afinfo->family] = afinfo;
2136         }
2137         write_unlock_bh(&xfrm_policy_afinfo_lock);
2138         return err;
2139 }
2140 EXPORT_SYMBOL(xfrm_policy_register_afinfo);
2141
2142 int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
2143 {
2144         int err = 0;
2145         if (unlikely(afinfo == NULL))
2146                 return -EINVAL;
2147         if (unlikely(afinfo->family >= NPROTO))
2148                 return -EAFNOSUPPORT;
2149         write_lock_bh(&xfrm_policy_afinfo_lock);
2150         if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
2151                 if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
2152                         err = -EINVAL;
2153                 else {
2154                         struct dst_ops *dst_ops = afinfo->dst_ops;
2155                         xfrm_policy_afinfo[afinfo->family] = NULL;
2156                         dst_ops->kmem_cachep = NULL;
2157                         dst_ops->check = NULL;
2158                         dst_ops->negative_advice = NULL;
2159                         dst_ops->link_failure = NULL;
2160                         afinfo->garbage_collect = NULL;
2161                 }
2162         }
2163         write_unlock_bh(&xfrm_policy_afinfo_lock);
2164         return err;
2165 }
2166 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
2167
2168 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
2169 {
2170         struct xfrm_policy_afinfo *afinfo;
2171         if (unlikely(family >= NPROTO))
2172                 return NULL;
2173         read_lock(&xfrm_policy_afinfo_lock);
2174         afinfo = xfrm_policy_afinfo[family];
2175         if (unlikely(!afinfo))
2176                 read_unlock(&xfrm_policy_afinfo_lock);
2177         return afinfo;
2178 }
2179
2180 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
2181 {
2182         read_unlock(&xfrm_policy_afinfo_lock);
2183 }
2184
2185 static struct xfrm_policy_afinfo *xfrm_policy_lock_afinfo(unsigned int family)
2186 {
2187         struct xfrm_policy_afinfo *afinfo;
2188         if (unlikely(family >= NPROTO))
2189                 return NULL;
2190         write_lock_bh(&xfrm_policy_afinfo_lock);
2191         afinfo = xfrm_policy_afinfo[family];
2192         if (unlikely(!afinfo))
2193                 write_unlock_bh(&xfrm_policy_afinfo_lock);
2194         return afinfo;
2195 }
2196
2197 static void xfrm_policy_unlock_afinfo(struct xfrm_policy_afinfo *afinfo)
2198 {
2199         write_unlock_bh(&xfrm_policy_afinfo_lock);
2200 }
2201
2202 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
2203 {
2204         switch (event) {
2205         case NETDEV_DOWN:
2206                 xfrm_flush_bundles();
2207         }
2208         return NOTIFY_DONE;
2209 }
2210
2211 static struct notifier_block xfrm_dev_notifier = {
2212         xfrm_dev_event,
2213         NULL,
2214         0
2215 };
2216
2217 static void __init xfrm_policy_init(void)
2218 {
2219         unsigned int hmask, sz;
2220         int dir;
2221
2222         xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache",
2223                                            sizeof(struct xfrm_dst),
2224                                            0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
2225                                            NULL, NULL);
2226
2227         hmask = 8 - 1;
2228         sz = (hmask+1) * sizeof(struct hlist_head);
2229
2230         xfrm_policy_byidx = xfrm_hash_alloc(sz);
2231         xfrm_idx_hmask = hmask;
2232         if (!xfrm_policy_byidx)
2233                 panic("XFRM: failed to allocate byidx hash\n");
2234
2235         for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
2236                 struct xfrm_policy_hash *htab;
2237
2238                 INIT_HLIST_HEAD(&xfrm_policy_inexact[dir]);
2239
2240                 htab = &xfrm_policy_bydst[dir];
2241                 htab->table = xfrm_hash_alloc(sz);
2242                 htab->hmask = hmask;
2243                 if (!htab->table)
2244                         panic("XFRM: failed to allocate bydst hash\n");
2245         }
2246
2247         INIT_WORK(&xfrm_policy_gc_work, xfrm_policy_gc_task);
2248         register_netdevice_notifier(&xfrm_dev_notifier);
2249 }
2250
2251 void __init xfrm_init(void)
2252 {
2253         xfrm_state_init();
2254         xfrm_policy_init();
2255         xfrm_input_init();
2256 }
2257
2258 #ifdef CONFIG_XFRM_MIGRATE
2259 static int xfrm_migrate_selector_match(struct xfrm_selector *sel_cmp,
2260                                        struct xfrm_selector *sel_tgt)
2261 {
2262         if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
2263                 if (sel_tgt->family == sel_cmp->family &&
2264                     xfrm_addr_cmp(&sel_tgt->daddr, &sel_cmp->daddr,
2265                                   sel_cmp->family) == 0 &&
2266                     xfrm_addr_cmp(&sel_tgt->saddr, &sel_cmp->saddr,
2267                                   sel_cmp->family) == 0 &&
2268                     sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
2269                     sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
2270                         return 1;
2271                 }
2272         } else {
2273                 if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
2274                         return 1;
2275                 }
2276         }
2277         return 0;
2278 }
2279
2280 static struct xfrm_policy * xfrm_migrate_policy_find(struct xfrm_selector *sel,
2281                                                      u8 dir, u8 type)
2282 {
2283         struct xfrm_policy *pol, *ret = NULL;
2284         struct hlist_node *entry;
2285         struct hlist_head *chain;
2286         u32 priority = ~0U;
2287
2288         read_lock_bh(&xfrm_policy_lock);
2289         chain = policy_hash_direct(&sel->daddr, &sel->saddr, sel->family, dir);
2290         hlist_for_each_entry(pol, entry, chain, bydst) {
2291                 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
2292                     pol->type == type) {
2293                         ret = pol;
2294                         priority = ret->priority;
2295                         break;
2296                 }
2297         }
2298         chain = &xfrm_policy_inexact[dir];
2299         hlist_for_each_entry(pol, entry, chain, bydst) {
2300                 if (xfrm_migrate_selector_match(sel, &pol->selector) &&
2301                     pol->type == type &&
2302                     pol->priority < priority) {
2303                         ret = pol;
2304                         break;
2305                 }
2306         }
2307
2308         if (ret)
2309                 xfrm_pol_hold(ret);
2310
2311         read_unlock_bh(&xfrm_policy_lock);
2312
2313         return ret;
2314 }
2315
2316 static int migrate_tmpl_match(struct xfrm_migrate *m, struct xfrm_tmpl *t)
2317 {
2318         int match = 0;
2319
2320         if (t->mode == m->mode && t->id.proto == m->proto &&
2321             (m->reqid == 0 || t->reqid == m->reqid)) {
2322                 switch (t->mode) {
2323                 case XFRM_MODE_TUNNEL:
2324                 case XFRM_MODE_BEET:
2325                         if (xfrm_addr_cmp(&t->id.daddr, &m->old_daddr,
2326                                           m->old_family) == 0 &&
2327                             xfrm_addr_cmp(&t->saddr, &m->old_saddr,
2328                                           m->old_family) == 0) {
2329                                 match = 1;
2330                         }
2331                         break;
2332                 case XFRM_MODE_TRANSPORT:
2333                         /* in case of transport mode, template does not store
2334                            any IP addresses, hence we just compare mode and
2335                            protocol */
2336                         match = 1;
2337                         break;
2338                 default:
2339                         break;
2340                 }
2341         }
2342         return match;
2343 }
2344
2345 /* update endpoint address(es) of template(s) */
2346 static int xfrm_policy_migrate(struct xfrm_policy *pol,
2347                                struct xfrm_migrate *m, int num_migrate)
2348 {
2349         struct xfrm_migrate *mp;
2350         struct dst_entry *dst;
2351         int i, j, n = 0;
2352
2353         write_lock_bh(&pol->lock);
2354         if (unlikely(pol->dead)) {
2355                 /* target policy has been deleted */
2356                 write_unlock_bh(&pol->lock);
2357                 return -ENOENT;
2358         }
2359
2360         for (i = 0; i < pol->xfrm_nr; i++) {
2361                 for (j = 0, mp = m; j < num_migrate; j++, mp++) {
2362                         if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i]))
2363                                 continue;
2364                         n++;
2365                         if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL)
2366                                 continue;
2367                         /* update endpoints */
2368                         memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
2369                                sizeof(pol->xfrm_vec[i].id.daddr));
2370                         memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr,
2371                                sizeof(pol->xfrm_vec[i].saddr));
2372                         pol->xfrm_vec[i].encap_family = mp->new_family;
2373                         /* flush bundles */
2374                         while ((dst = pol->bundles) != NULL) {
2375                                 pol->bundles = dst->next;
2376                                 dst_free(dst);
2377                         }
2378                 }
2379         }
2380
2381         write_unlock_bh(&pol->lock);
2382
2383         if (!n)
2384                 return -ENODATA;
2385
2386         return 0;
2387 }
2388
2389 static int xfrm_migrate_check(struct xfrm_migrate *m, int num_migrate)
2390 {
2391         int i, j;
2392
2393         if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
2394                 return -EINVAL;
2395
2396         for (i = 0; i < num_migrate; i++) {
2397                 if ((xfrm_addr_cmp(&m[i].old_daddr, &m[i].new_daddr,
2398                                    m[i].old_family) == 0) &&
2399                     (xfrm_addr_cmp(&m[i].old_saddr, &m[i].new_saddr,
2400                                    m[i].old_family) == 0))
2401                         return -EINVAL;
2402                 if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
2403                     xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
2404                         return -EINVAL;
2405
2406                 /* check if there is any duplicated entry */
2407                 for (j = i + 1; j < num_migrate; j++) {
2408                         if (!memcmp(&m[i].old_daddr, &m[j].old_daddr,
2409                                     sizeof(m[i].old_daddr)) &&
2410                             !memcmp(&m[i].old_saddr, &m[j].old_saddr,
2411                                     sizeof(m[i].old_saddr)) &&
2412                             m[i].proto == m[j].proto &&
2413                             m[i].mode == m[j].mode &&
2414                             m[i].reqid == m[j].reqid &&
2415                             m[i].old_family == m[j].old_family)
2416                                 return -EINVAL;
2417                 }
2418         }
2419
2420         return 0;
2421 }
2422
2423 int xfrm_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
2424                  struct xfrm_migrate *m, int num_migrate)
2425 {
2426         int i, err, nx_cur = 0, nx_new = 0;
2427         struct xfrm_policy *pol = NULL;
2428         struct xfrm_state *x, *xc;
2429         struct xfrm_state *x_cur[XFRM_MAX_DEPTH];
2430         struct xfrm_state *x_new[XFRM_MAX_DEPTH];
2431         struct xfrm_migrate *mp;
2432
2433         if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
2434                 goto out;
2435
2436         /* Stage 1 - find policy */
2437         if ((pol = xfrm_migrate_policy_find(sel, dir, type)) == NULL) {
2438                 err = -ENOENT;
2439                 goto out;
2440         }
2441
2442         /* Stage 2 - find and update state(s) */
2443         for (i = 0, mp = m; i < num_migrate; i++, mp++) {
2444                 if ((x = xfrm_migrate_state_find(mp))) {
2445                         x_cur[nx_cur] = x;
2446                         nx_cur++;
2447                         if ((xc = xfrm_state_migrate(x, mp))) {
2448                                 x_new[nx_new] = xc;
2449                                 nx_new++;
2450                         } else {
2451                                 err = -ENODATA;
2452                                 goto restore_state;
2453                         }
2454                 }
2455         }
2456
2457         /* Stage 3 - update policy */
2458         if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
2459                 goto restore_state;
2460
2461         /* Stage 4 - delete old state(s) */
2462         if (nx_cur) {
2463                 xfrm_states_put(x_cur, nx_cur);
2464                 xfrm_states_delete(x_cur, nx_cur);
2465         }
2466
2467         /* Stage 5 - announce */
2468         km_migrate(sel, dir, type, m, num_migrate);
2469
2470         xfrm_pol_put(pol);
2471
2472         return 0;
2473 out:
2474         return err;
2475
2476 restore_state:
2477         if (pol)
2478                 xfrm_pol_put(pol);
2479         if (nx_cur)
2480                 xfrm_states_put(x_cur, nx_cur);
2481         if (nx_new)
2482                 xfrm_states_delete(x_new, nx_new);
2483
2484         return err;
2485 }
2486 EXPORT_SYMBOL(xfrm_migrate);
2487 #endif
2488