1 /* 2 * xfrm_policy.c 3 * 4 * Changes: 5 * Mitsuru KANDA @USAGI 6 * Kazunori MIYAZAWA @USAGI 7 * Kunihiro Ishiguro <kunihiro@ipinfusion.com> 8 * IPv6 support 9 * Kazunori MIYAZAWA @USAGI 10 * YOSHIFUJI Hideaki 11 * Split up af-specific portion 12 * Derek Atkins <derek@ihtfp.com> Add the post_input processor 13 * 14 */ 15 16 #include <linux/err.h> 17 #include <linux/slab.h> 18 #include <linux/kmod.h> 19 #include <linux/list.h> 20 #include <linux/spinlock.h> 21 #include <linux/workqueue.h> 22 #include <linux/notifier.h> 23 #include <linux/netdevice.h> 24 #include <linux/netfilter.h> 25 #include <linux/module.h> 26 #include <linux/cache.h> 27 #include <linux/cpu.h> 28 #include <linux/audit.h> 29 #include <net/dst.h> 30 #include <net/flow.h> 31 #include <net/xfrm.h> 32 #include <net/ip.h> 33 #ifdef CONFIG_XFRM_STATISTICS 34 #include <net/snmp.h> 35 #endif 36 37 #include "xfrm_hash.h" 38 39 #define XFRM_QUEUE_TMO_MIN ((unsigned)(HZ/10)) 40 #define XFRM_QUEUE_TMO_MAX ((unsigned)(60*HZ)) 41 #define XFRM_MAX_QUEUE_LEN 100 42 43 struct xfrm_flo { 44 struct dst_entry *dst_orig; 45 u8 flags; 46 }; 47 48 static DEFINE_PER_CPU(struct xfrm_dst *, xfrm_last_dst); 49 static struct work_struct *xfrm_pcpu_work __read_mostly; 50 static DEFINE_SPINLOCK(xfrm_policy_afinfo_lock); 51 static struct xfrm_policy_afinfo const __rcu *xfrm_policy_afinfo[AF_INET6 + 1] 52 __read_mostly; 53 54 static struct kmem_cache *xfrm_dst_cache __ro_after_init; 55 static __read_mostly seqcount_t xfrm_policy_hash_generation; 56 57 static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr); 58 static int stale_bundle(struct dst_entry *dst); 59 static int xfrm_bundle_ok(struct xfrm_dst *xdst); 60 static void xfrm_policy_queue_process(struct timer_list *t); 61 62 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir); 63 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol, 64 int dir); 65 66 static inline bool xfrm_pol_hold_rcu(struct xfrm_policy *policy) 67 { 68 return refcount_inc_not_zero(&policy->refcnt); 69 } 70 71 static inline bool 72 __xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl) 73 { 74 const struct flowi4 *fl4 = &fl->u.ip4; 75 76 return addr4_match(fl4->daddr, sel->daddr.a4, sel->prefixlen_d) && 77 addr4_match(fl4->saddr, sel->saddr.a4, sel->prefixlen_s) && 78 !((xfrm_flowi_dport(fl, &fl4->uli) ^ sel->dport) & sel->dport_mask) && 79 !((xfrm_flowi_sport(fl, &fl4->uli) ^ sel->sport) & sel->sport_mask) && 80 (fl4->flowi4_proto == sel->proto || !sel->proto) && 81 (fl4->flowi4_oif == sel->ifindex || !sel->ifindex); 82 } 83 84 static inline bool 85 __xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl) 86 { 87 const struct flowi6 *fl6 = &fl->u.ip6; 88 89 return addr_match(&fl6->daddr, &sel->daddr, sel->prefixlen_d) && 90 addr_match(&fl6->saddr, &sel->saddr, sel->prefixlen_s) && 91 !((xfrm_flowi_dport(fl, &fl6->uli) ^ sel->dport) & sel->dport_mask) && 92 !((xfrm_flowi_sport(fl, &fl6->uli) ^ sel->sport) & sel->sport_mask) && 93 (fl6->flowi6_proto == sel->proto || !sel->proto) && 94 (fl6->flowi6_oif == sel->ifindex || !sel->ifindex); 95 } 96 97 bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl, 98 unsigned short family) 99 { 100 switch (family) { 101 case AF_INET: 102 return __xfrm4_selector_match(sel, fl); 103 case AF_INET6: 104 return __xfrm6_selector_match(sel, fl); 105 } 106 return false; 107 } 108 109 static const struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family) 110 { 111 const struct xfrm_policy_afinfo *afinfo; 112 113 if (unlikely(family >= ARRAY_SIZE(xfrm_policy_afinfo))) 114 return NULL; 115 rcu_read_lock(); 116 afinfo = rcu_dereference(xfrm_policy_afinfo[family]); 117 if (unlikely(!afinfo)) 118 rcu_read_unlock(); 119 return afinfo; 120 } 121 122 struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos, int oif, 123 const xfrm_address_t *saddr, 124 const xfrm_address_t *daddr, 125 int family, u32 mark) 126 { 127 const struct xfrm_policy_afinfo *afinfo; 128 struct dst_entry *dst; 129 130 afinfo = xfrm_policy_get_afinfo(family); 131 if (unlikely(afinfo == NULL)) 132 return ERR_PTR(-EAFNOSUPPORT); 133 134 dst = afinfo->dst_lookup(net, tos, oif, saddr, daddr, mark); 135 136 rcu_read_unlock(); 137 138 return dst; 139 } 140 EXPORT_SYMBOL(__xfrm_dst_lookup); 141 142 static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x, 143 int tos, int oif, 144 xfrm_address_t *prev_saddr, 145 xfrm_address_t *prev_daddr, 146 int family, u32 mark) 147 { 148 struct net *net = xs_net(x); 149 xfrm_address_t *saddr = &x->props.saddr; 150 xfrm_address_t *daddr = &x->id.daddr; 151 struct dst_entry *dst; 152 153 if (x->type->flags & XFRM_TYPE_LOCAL_COADDR) { 154 saddr = x->coaddr; 155 daddr = prev_daddr; 156 } 157 if (x->type->flags & XFRM_TYPE_REMOTE_COADDR) { 158 saddr = prev_saddr; 159 daddr = x->coaddr; 160 } 161 162 dst = __xfrm_dst_lookup(net, tos, oif, saddr, daddr, family, mark); 163 164 if (!IS_ERR(dst)) { 165 if (prev_saddr != saddr) 166 memcpy(prev_saddr, saddr, sizeof(*prev_saddr)); 167 if (prev_daddr != daddr) 168 memcpy(prev_daddr, daddr, sizeof(*prev_daddr)); 169 } 170 171 return dst; 172 } 173 174 static inline unsigned long make_jiffies(long secs) 175 { 176 if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ) 177 return MAX_SCHEDULE_TIMEOUT-1; 178 else 179 return secs*HZ; 180 } 181 182 static void xfrm_policy_timer(struct timer_list *t) 183 { 184 struct xfrm_policy *xp = from_timer(xp, t, timer); 185 unsigned long now = get_seconds(); 186 long next = LONG_MAX; 187 int warn = 0; 188 int dir; 189 190 read_lock(&xp->lock); 191 192 if (unlikely(xp->walk.dead)) 193 goto out; 194 195 dir = xfrm_policy_id2dir(xp->index); 196 197 if (xp->lft.hard_add_expires_seconds) { 198 long tmo = xp->lft.hard_add_expires_seconds + 199 xp->curlft.add_time - now; 200 if (tmo <= 0) 201 goto expired; 202 if (tmo < next) 203 next = tmo; 204 } 205 if (xp->lft.hard_use_expires_seconds) { 206 long tmo = xp->lft.hard_use_expires_seconds + 207 (xp->curlft.use_time ? : xp->curlft.add_time) - now; 208 if (tmo <= 0) 209 goto expired; 210 if (tmo < next) 211 next = tmo; 212 } 213 if (xp->lft.soft_add_expires_seconds) { 214 long tmo = xp->lft.soft_add_expires_seconds + 215 xp->curlft.add_time - now; 216 if (tmo <= 0) { 217 warn = 1; 218 tmo = XFRM_KM_TIMEOUT; 219 } 220 if (tmo < next) 221 next = tmo; 222 } 223 if (xp->lft.soft_use_expires_seconds) { 224 long tmo = xp->lft.soft_use_expires_seconds + 225 (xp->curlft.use_time ? : xp->curlft.add_time) - now; 226 if (tmo <= 0) { 227 warn = 1; 228 tmo = XFRM_KM_TIMEOUT; 229 } 230 if (tmo < next) 231 next = tmo; 232 } 233 234 if (warn) 235 km_policy_expired(xp, dir, 0, 0); 236 if (next != LONG_MAX && 237 !mod_timer(&xp->timer, jiffies + make_jiffies(next))) 238 xfrm_pol_hold(xp); 239 240 out: 241 read_unlock(&xp->lock); 242 xfrm_pol_put(xp); 243 return; 244 245 expired: 246 read_unlock(&xp->lock); 247 if (!xfrm_policy_delete(xp, dir)) 248 km_policy_expired(xp, dir, 1, 0); 249 xfrm_pol_put(xp); 250 } 251 252 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2 253 * SPD calls. 254 */ 255 256 struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp) 257 { 258 struct xfrm_policy *policy; 259 260 policy = kzalloc(sizeof(struct xfrm_policy), gfp); 261 262 if (policy) { 263 write_pnet(&policy->xp_net, net); 264 INIT_LIST_HEAD(&policy->walk.all); 265 INIT_HLIST_NODE(&policy->bydst); 266 INIT_HLIST_NODE(&policy->byidx); 267 rwlock_init(&policy->lock); 268 refcount_set(&policy->refcnt, 1); 269 skb_queue_head_init(&policy->polq.hold_queue); 270 timer_setup(&policy->timer, xfrm_policy_timer, 0); 271 timer_setup(&policy->polq.hold_timer, 272 xfrm_policy_queue_process, 0); 273 } 274 return policy; 275 } 276 EXPORT_SYMBOL(xfrm_policy_alloc); 277 278 static void xfrm_policy_destroy_rcu(struct rcu_head *head) 279 { 280 struct xfrm_policy *policy = container_of(head, struct xfrm_policy, rcu); 281 282 security_xfrm_policy_free(policy->security); 283 kfree(policy); 284 } 285 286 /* Destroy xfrm_policy: descendant resources must be released to this moment. */ 287 288 void xfrm_policy_destroy(struct xfrm_policy *policy) 289 { 290 BUG_ON(!policy->walk.dead); 291 292 if (del_timer(&policy->timer) || del_timer(&policy->polq.hold_timer)) 293 BUG(); 294 295 call_rcu(&policy->rcu, xfrm_policy_destroy_rcu); 296 } 297 EXPORT_SYMBOL(xfrm_policy_destroy); 298 299 /* Rule must be locked. Release descendant resources, announce 300 * entry dead. The rule must be unlinked from lists to the moment. 301 */ 302 303 static void xfrm_policy_kill(struct xfrm_policy *policy) 304 { 305 policy->walk.dead = 1; 306 307 atomic_inc(&policy->genid); 308 309 if (del_timer(&policy->polq.hold_timer)) 310 xfrm_pol_put(policy); 311 skb_queue_purge(&policy->polq.hold_queue); 312 313 if (del_timer(&policy->timer)) 314 xfrm_pol_put(policy); 315 316 xfrm_pol_put(policy); 317 } 318 319 static unsigned int xfrm_policy_hashmax __read_mostly = 1 * 1024 * 1024; 320 321 static inline unsigned int idx_hash(struct net *net, u32 index) 322 { 323 return __idx_hash(index, net->xfrm.policy_idx_hmask); 324 } 325 326 /* calculate policy hash thresholds */ 327 static void __get_hash_thresh(struct net *net, 328 unsigned short family, int dir, 329 u8 *dbits, u8 *sbits) 330 { 331 switch (family) { 332 case AF_INET: 333 *dbits = net->xfrm.policy_bydst[dir].dbits4; 334 *sbits = net->xfrm.policy_bydst[dir].sbits4; 335 break; 336 337 case AF_INET6: 338 *dbits = net->xfrm.policy_bydst[dir].dbits6; 339 *sbits = net->xfrm.policy_bydst[dir].sbits6; 340 break; 341 342 default: 343 *dbits = 0; 344 *sbits = 0; 345 } 346 } 347 348 static struct hlist_head *policy_hash_bysel(struct net *net, 349 const struct xfrm_selector *sel, 350 unsigned short family, int dir) 351 { 352 unsigned int hmask = net->xfrm.policy_bydst[dir].hmask; 353 unsigned int hash; 354 u8 dbits; 355 u8 sbits; 356 357 __get_hash_thresh(net, family, dir, &dbits, &sbits); 358 hash = __sel_hash(sel, family, hmask, dbits, sbits); 359 360 if (hash == hmask + 1) 361 return &net->xfrm.policy_inexact[dir]; 362 363 return rcu_dereference_check(net->xfrm.policy_bydst[dir].table, 364 lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash; 365 } 366 367 static struct hlist_head *policy_hash_direct(struct net *net, 368 const xfrm_address_t *daddr, 369 const xfrm_address_t *saddr, 370 unsigned short family, int dir) 371 { 372 unsigned int hmask = net->xfrm.policy_bydst[dir].hmask; 373 unsigned int hash; 374 u8 dbits; 375 u8 sbits; 376 377 __get_hash_thresh(net, family, dir, &dbits, &sbits); 378 hash = __addr_hash(daddr, saddr, family, hmask, dbits, sbits); 379 380 return rcu_dereference_check(net->xfrm.policy_bydst[dir].table, 381 lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash; 382 } 383 384 static void xfrm_dst_hash_transfer(struct net *net, 385 struct hlist_head *list, 386 struct hlist_head *ndsttable, 387 unsigned int nhashmask, 388 int dir) 389 { 390 struct hlist_node *tmp, *entry0 = NULL; 391 struct xfrm_policy *pol; 392 unsigned int h0 = 0; 393 u8 dbits; 394 u8 sbits; 395 396 redo: 397 hlist_for_each_entry_safe(pol, tmp, list, bydst) { 398 unsigned int h; 399 400 __get_hash_thresh(net, pol->family, dir, &dbits, &sbits); 401 h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr, 402 pol->family, nhashmask, dbits, sbits); 403 if (!entry0) { 404 hlist_del_rcu(&pol->bydst); 405 hlist_add_head_rcu(&pol->bydst, ndsttable + h); 406 h0 = h; 407 } else { 408 if (h != h0) 409 continue; 410 hlist_del_rcu(&pol->bydst); 411 hlist_add_behind_rcu(&pol->bydst, entry0); 412 } 413 entry0 = &pol->bydst; 414 } 415 if (!hlist_empty(list)) { 416 entry0 = NULL; 417 goto redo; 418 } 419 } 420 421 static void xfrm_idx_hash_transfer(struct hlist_head *list, 422 struct hlist_head *nidxtable, 423 unsigned int nhashmask) 424 { 425 struct hlist_node *tmp; 426 struct xfrm_policy *pol; 427 428 hlist_for_each_entry_safe(pol, tmp, list, byidx) { 429 unsigned int h; 430 431 h = __idx_hash(pol->index, nhashmask); 432 hlist_add_head(&pol->byidx, nidxtable+h); 433 } 434 } 435 436 static unsigned long xfrm_new_hash_mask(unsigned int old_hmask) 437 { 438 return ((old_hmask + 1) << 1) - 1; 439 } 440 441 static void xfrm_bydst_resize(struct net *net, int dir) 442 { 443 unsigned int hmask = net->xfrm.policy_bydst[dir].hmask; 444 unsigned int nhashmask = xfrm_new_hash_mask(hmask); 445 unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head); 446 struct hlist_head *ndst = xfrm_hash_alloc(nsize); 447 struct hlist_head *odst; 448 int i; 449 450 if (!ndst) 451 return; 452 453 spin_lock_bh(&net->xfrm.xfrm_policy_lock); 454 write_seqcount_begin(&xfrm_policy_hash_generation); 455 456 odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table, 457 lockdep_is_held(&net->xfrm.xfrm_policy_lock)); 458 459 odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table, 460 lockdep_is_held(&net->xfrm.xfrm_policy_lock)); 461 462 for (i = hmask; i >= 0; i--) 463 xfrm_dst_hash_transfer(net, odst + i, ndst, nhashmask, dir); 464 465 rcu_assign_pointer(net->xfrm.policy_bydst[dir].table, ndst); 466 net->xfrm.policy_bydst[dir].hmask = nhashmask; 467 468 write_seqcount_end(&xfrm_policy_hash_generation); 469 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 470 471 synchronize_rcu(); 472 473 xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head)); 474 } 475 476 static void xfrm_byidx_resize(struct net *net, int total) 477 { 478 unsigned int hmask = net->xfrm.policy_idx_hmask; 479 unsigned int nhashmask = xfrm_new_hash_mask(hmask); 480 unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head); 481 struct hlist_head *oidx = net->xfrm.policy_byidx; 482 struct hlist_head *nidx = xfrm_hash_alloc(nsize); 483 int i; 484 485 if (!nidx) 486 return; 487 488 spin_lock_bh(&net->xfrm.xfrm_policy_lock); 489 490 for (i = hmask; i >= 0; i--) 491 xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask); 492 493 net->xfrm.policy_byidx = nidx; 494 net->xfrm.policy_idx_hmask = nhashmask; 495 496 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 497 498 xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head)); 499 } 500 501 static inline int xfrm_bydst_should_resize(struct net *net, int dir, int *total) 502 { 503 unsigned int cnt = net->xfrm.policy_count[dir]; 504 unsigned int hmask = net->xfrm.policy_bydst[dir].hmask; 505 506 if (total) 507 *total += cnt; 508 509 if ((hmask + 1) < xfrm_policy_hashmax && 510 cnt > hmask) 511 return 1; 512 513 return 0; 514 } 515 516 static inline int xfrm_byidx_should_resize(struct net *net, int total) 517 { 518 unsigned int hmask = net->xfrm.policy_idx_hmask; 519 520 if ((hmask + 1) < xfrm_policy_hashmax && 521 total > hmask) 522 return 1; 523 524 return 0; 525 } 526 527 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si) 528 { 529 si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN]; 530 si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT]; 531 si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD]; 532 si->inscnt = net->xfrm.policy_count[XFRM_POLICY_IN+XFRM_POLICY_MAX]; 533 si->outscnt = net->xfrm.policy_count[XFRM_POLICY_OUT+XFRM_POLICY_MAX]; 534 si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX]; 535 si->spdhcnt = net->xfrm.policy_idx_hmask; 536 si->spdhmcnt = xfrm_policy_hashmax; 537 } 538 EXPORT_SYMBOL(xfrm_spd_getinfo); 539 540 static DEFINE_MUTEX(hash_resize_mutex); 541 static void xfrm_hash_resize(struct work_struct *work) 542 { 543 struct net *net = container_of(work, struct net, xfrm.policy_hash_work); 544 int dir, total; 545 546 mutex_lock(&hash_resize_mutex); 547 548 total = 0; 549 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) { 550 if (xfrm_bydst_should_resize(net, dir, &total)) 551 xfrm_bydst_resize(net, dir); 552 } 553 if (xfrm_byidx_should_resize(net, total)) 554 xfrm_byidx_resize(net, total); 555 556 mutex_unlock(&hash_resize_mutex); 557 } 558 559 static void xfrm_hash_rebuild(struct work_struct *work) 560 { 561 struct net *net = container_of(work, struct net, 562 xfrm.policy_hthresh.work); 563 unsigned int hmask; 564 struct xfrm_policy *pol; 565 struct xfrm_policy *policy; 566 struct hlist_head *chain; 567 struct hlist_head *odst; 568 struct hlist_node *newpos; 569 int i; 570 int dir; 571 unsigned seq; 572 u8 lbits4, rbits4, lbits6, rbits6; 573 574 mutex_lock(&hash_resize_mutex); 575 576 /* read selector prefixlen thresholds */ 577 do { 578 seq = read_seqbegin(&net->xfrm.policy_hthresh.lock); 579 580 lbits4 = net->xfrm.policy_hthresh.lbits4; 581 rbits4 = net->xfrm.policy_hthresh.rbits4; 582 lbits6 = net->xfrm.policy_hthresh.lbits6; 583 rbits6 = net->xfrm.policy_hthresh.rbits6; 584 } while (read_seqretry(&net->xfrm.policy_hthresh.lock, seq)); 585 586 spin_lock_bh(&net->xfrm.xfrm_policy_lock); 587 588 /* reset the bydst and inexact table in all directions */ 589 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) { 590 INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]); 591 hmask = net->xfrm.policy_bydst[dir].hmask; 592 odst = net->xfrm.policy_bydst[dir].table; 593 for (i = hmask; i >= 0; i--) 594 INIT_HLIST_HEAD(odst + i); 595 if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) { 596 /* dir out => dst = remote, src = local */ 597 net->xfrm.policy_bydst[dir].dbits4 = rbits4; 598 net->xfrm.policy_bydst[dir].sbits4 = lbits4; 599 net->xfrm.policy_bydst[dir].dbits6 = rbits6; 600 net->xfrm.policy_bydst[dir].sbits6 = lbits6; 601 } else { 602 /* dir in/fwd => dst = local, src = remote */ 603 net->xfrm.policy_bydst[dir].dbits4 = lbits4; 604 net->xfrm.policy_bydst[dir].sbits4 = rbits4; 605 net->xfrm.policy_bydst[dir].dbits6 = lbits6; 606 net->xfrm.policy_bydst[dir].sbits6 = rbits6; 607 } 608 } 609 610 /* re-insert all policies by order of creation */ 611 list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) { 612 if (policy->walk.dead || 613 xfrm_policy_id2dir(policy->index) >= XFRM_POLICY_MAX) { 614 /* skip socket policies */ 615 continue; 616 } 617 newpos = NULL; 618 chain = policy_hash_bysel(net, &policy->selector, 619 policy->family, 620 xfrm_policy_id2dir(policy->index)); 621 hlist_for_each_entry(pol, chain, bydst) { 622 if (policy->priority >= pol->priority) 623 newpos = &pol->bydst; 624 else 625 break; 626 } 627 if (newpos) 628 hlist_add_behind(&policy->bydst, newpos); 629 else 630 hlist_add_head(&policy->bydst, chain); 631 } 632 633 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 634 635 mutex_unlock(&hash_resize_mutex); 636 } 637 638 void xfrm_policy_hash_rebuild(struct net *net) 639 { 640 schedule_work(&net->xfrm.policy_hthresh.work); 641 } 642 EXPORT_SYMBOL(xfrm_policy_hash_rebuild); 643 644 /* Generate new index... KAME seems to generate them ordered by cost 645 * of an absolute inpredictability of ordering of rules. This will not pass. */ 646 static u32 xfrm_gen_index(struct net *net, int dir, u32 index) 647 { 648 static u32 idx_generator; 649 650 for (;;) { 651 struct hlist_head *list; 652 struct xfrm_policy *p; 653 u32 idx; 654 int found; 655 656 if (!index) { 657 idx = (idx_generator | dir); 658 idx_generator += 8; 659 } else { 660 idx = index; 661 index = 0; 662 } 663 664 if (idx == 0) 665 idx = 8; 666 list = net->xfrm.policy_byidx + idx_hash(net, idx); 667 found = 0; 668 hlist_for_each_entry(p, list, byidx) { 669 if (p->index == idx) { 670 found = 1; 671 break; 672 } 673 } 674 if (!found) 675 return idx; 676 } 677 } 678 679 static inline int selector_cmp(struct xfrm_selector *s1, struct xfrm_selector *s2) 680 { 681 u32 *p1 = (u32 *) s1; 682 u32 *p2 = (u32 *) s2; 683 int len = sizeof(struct xfrm_selector) / sizeof(u32); 684 int i; 685 686 for (i = 0; i < len; i++) { 687 if (p1[i] != p2[i]) 688 return 1; 689 } 690 691 return 0; 692 } 693 694 static void xfrm_policy_requeue(struct xfrm_policy *old, 695 struct xfrm_policy *new) 696 { 697 struct xfrm_policy_queue *pq = &old->polq; 698 struct sk_buff_head list; 699 700 if (skb_queue_empty(&pq->hold_queue)) 701 return; 702 703 __skb_queue_head_init(&list); 704 705 spin_lock_bh(&pq->hold_queue.lock); 706 skb_queue_splice_init(&pq->hold_queue, &list); 707 if (del_timer(&pq->hold_timer)) 708 xfrm_pol_put(old); 709 spin_unlock_bh(&pq->hold_queue.lock); 710 711 pq = &new->polq; 712 713 spin_lock_bh(&pq->hold_queue.lock); 714 skb_queue_splice(&list, &pq->hold_queue); 715 pq->timeout = XFRM_QUEUE_TMO_MIN; 716 if (!mod_timer(&pq->hold_timer, jiffies)) 717 xfrm_pol_hold(new); 718 spin_unlock_bh(&pq->hold_queue.lock); 719 } 720 721 static bool xfrm_policy_mark_match(struct xfrm_policy *policy, 722 struct xfrm_policy *pol) 723 { 724 u32 mark = policy->mark.v & policy->mark.m; 725 726 if (policy->mark.v == pol->mark.v && policy->mark.m == pol->mark.m) 727 return true; 728 729 if ((mark & pol->mark.m) == pol->mark.v && 730 policy->priority == pol->priority) 731 return true; 732 733 return false; 734 } 735 736 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl) 737 { 738 struct net *net = xp_net(policy); 739 struct xfrm_policy *pol; 740 struct xfrm_policy *delpol; 741 struct hlist_head *chain; 742 struct hlist_node *newpos; 743 744 spin_lock_bh(&net->xfrm.xfrm_policy_lock); 745 chain = policy_hash_bysel(net, &policy->selector, policy->family, dir); 746 delpol = NULL; 747 newpos = NULL; 748 hlist_for_each_entry(pol, chain, bydst) { 749 if (pol->type == policy->type && 750 !selector_cmp(&pol->selector, &policy->selector) && 751 xfrm_policy_mark_match(policy, pol) && 752 xfrm_sec_ctx_match(pol->security, policy->security) && 753 !WARN_ON(delpol)) { 754 if (excl) { 755 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 756 return -EEXIST; 757 } 758 delpol = pol; 759 if (policy->priority > pol->priority) 760 continue; 761 } else if (policy->priority >= pol->priority) { 762 newpos = &pol->bydst; 763 continue; 764 } 765 if (delpol) 766 break; 767 } 768 if (newpos) 769 hlist_add_behind(&policy->bydst, newpos); 770 else 771 hlist_add_head(&policy->bydst, chain); 772 __xfrm_policy_link(policy, dir); 773 774 /* After previous checking, family can either be AF_INET or AF_INET6 */ 775 if (policy->family == AF_INET) 776 rt_genid_bump_ipv4(net); 777 else 778 rt_genid_bump_ipv6(net); 779 780 if (delpol) { 781 xfrm_policy_requeue(delpol, policy); 782 __xfrm_policy_unlink(delpol, dir); 783 } 784 policy->index = delpol ? delpol->index : xfrm_gen_index(net, dir, policy->index); 785 hlist_add_head(&policy->byidx, net->xfrm.policy_byidx+idx_hash(net, policy->index)); 786 policy->curlft.add_time = get_seconds(); 787 policy->curlft.use_time = 0; 788 if (!mod_timer(&policy->timer, jiffies + HZ)) 789 xfrm_pol_hold(policy); 790 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 791 792 if (delpol) 793 xfrm_policy_kill(delpol); 794 else if (xfrm_bydst_should_resize(net, dir, NULL)) 795 schedule_work(&net->xfrm.policy_hash_work); 796 797 return 0; 798 } 799 EXPORT_SYMBOL(xfrm_policy_insert); 800 801 struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u8 type, 802 int dir, struct xfrm_selector *sel, 803 struct xfrm_sec_ctx *ctx, int delete, 804 int *err) 805 { 806 struct xfrm_policy *pol, *ret; 807 struct hlist_head *chain; 808 809 *err = 0; 810 spin_lock_bh(&net->xfrm.xfrm_policy_lock); 811 chain = policy_hash_bysel(net, sel, sel->family, dir); 812 ret = NULL; 813 hlist_for_each_entry(pol, chain, bydst) { 814 if (pol->type == type && 815 (mark & pol->mark.m) == pol->mark.v && 816 !selector_cmp(sel, &pol->selector) && 817 xfrm_sec_ctx_match(ctx, pol->security)) { 818 xfrm_pol_hold(pol); 819 if (delete) { 820 *err = security_xfrm_policy_delete( 821 pol->security); 822 if (*err) { 823 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 824 return pol; 825 } 826 __xfrm_policy_unlink(pol, dir); 827 } 828 ret = pol; 829 break; 830 } 831 } 832 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 833 834 if (ret && delete) 835 xfrm_policy_kill(ret); 836 return ret; 837 } 838 EXPORT_SYMBOL(xfrm_policy_bysel_ctx); 839 840 struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8 type, 841 int dir, u32 id, int delete, int *err) 842 { 843 struct xfrm_policy *pol, *ret; 844 struct hlist_head *chain; 845 846 *err = -ENOENT; 847 if (xfrm_policy_id2dir(id) != dir) 848 return NULL; 849 850 *err = 0; 851 spin_lock_bh(&net->xfrm.xfrm_policy_lock); 852 chain = net->xfrm.policy_byidx + idx_hash(net, id); 853 ret = NULL; 854 hlist_for_each_entry(pol, chain, byidx) { 855 if (pol->type == type && pol->index == id && 856 (mark & pol->mark.m) == pol->mark.v) { 857 xfrm_pol_hold(pol); 858 if (delete) { 859 *err = security_xfrm_policy_delete( 860 pol->security); 861 if (*err) { 862 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 863 return pol; 864 } 865 __xfrm_policy_unlink(pol, dir); 866 } 867 ret = pol; 868 break; 869 } 870 } 871 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 872 873 if (ret && delete) 874 xfrm_policy_kill(ret); 875 return ret; 876 } 877 EXPORT_SYMBOL(xfrm_policy_byid); 878 879 #ifdef CONFIG_SECURITY_NETWORK_XFRM 880 static inline int 881 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid) 882 { 883 int dir, err = 0; 884 885 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) { 886 struct xfrm_policy *pol; 887 int i; 888 889 hlist_for_each_entry(pol, 890 &net->xfrm.policy_inexact[dir], bydst) { 891 if (pol->type != type) 892 continue; 893 err = security_xfrm_policy_delete(pol->security); 894 if (err) { 895 xfrm_audit_policy_delete(pol, 0, task_valid); 896 return err; 897 } 898 } 899 for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) { 900 hlist_for_each_entry(pol, 901 net->xfrm.policy_bydst[dir].table + i, 902 bydst) { 903 if (pol->type != type) 904 continue; 905 err = security_xfrm_policy_delete( 906 pol->security); 907 if (err) { 908 xfrm_audit_policy_delete(pol, 0, 909 task_valid); 910 return err; 911 } 912 } 913 } 914 } 915 return err; 916 } 917 #else 918 static inline int 919 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid) 920 { 921 return 0; 922 } 923 #endif 924 925 int xfrm_policy_flush(struct net *net, u8 type, bool task_valid) 926 { 927 int dir, err = 0, cnt = 0; 928 929 spin_lock_bh(&net->xfrm.xfrm_policy_lock); 930 931 err = xfrm_policy_flush_secctx_check(net, type, task_valid); 932 if (err) 933 goto out; 934 935 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) { 936 struct xfrm_policy *pol; 937 int i; 938 939 again1: 940 hlist_for_each_entry(pol, 941 &net->xfrm.policy_inexact[dir], bydst) { 942 if (pol->type != type) 943 continue; 944 __xfrm_policy_unlink(pol, dir); 945 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 946 cnt++; 947 948 xfrm_audit_policy_delete(pol, 1, task_valid); 949 950 xfrm_policy_kill(pol); 951 952 spin_lock_bh(&net->xfrm.xfrm_policy_lock); 953 goto again1; 954 } 955 956 for (i = net->xfrm.policy_bydst[dir].hmask; i >= 0; i--) { 957 again2: 958 hlist_for_each_entry(pol, 959 net->xfrm.policy_bydst[dir].table + i, 960 bydst) { 961 if (pol->type != type) 962 continue; 963 __xfrm_policy_unlink(pol, dir); 964 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 965 cnt++; 966 967 xfrm_audit_policy_delete(pol, 1, task_valid); 968 xfrm_policy_kill(pol); 969 970 spin_lock_bh(&net->xfrm.xfrm_policy_lock); 971 goto again2; 972 } 973 } 974 975 } 976 if (!cnt) 977 err = -ESRCH; 978 out: 979 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 980 return err; 981 } 982 EXPORT_SYMBOL(xfrm_policy_flush); 983 984 int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk, 985 int (*func)(struct xfrm_policy *, int, int, void*), 986 void *data) 987 { 988 struct xfrm_policy *pol; 989 struct xfrm_policy_walk_entry *x; 990 int error = 0; 991 992 if (walk->type >= XFRM_POLICY_TYPE_MAX && 993 walk->type != XFRM_POLICY_TYPE_ANY) 994 return -EINVAL; 995 996 if (list_empty(&walk->walk.all) && walk->seq != 0) 997 return 0; 998 999 spin_lock_bh(&net->xfrm.xfrm_policy_lock); 1000 if (list_empty(&walk->walk.all)) 1001 x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all); 1002 else 1003 x = list_first_entry(&walk->walk.all, 1004 struct xfrm_policy_walk_entry, all); 1005 1006 list_for_each_entry_from(x, &net->xfrm.policy_all, all) { 1007 if (x->dead) 1008 continue; 1009 pol = container_of(x, struct xfrm_policy, walk); 1010 if (walk->type != XFRM_POLICY_TYPE_ANY && 1011 walk->type != pol->type) 1012 continue; 1013 error = func(pol, xfrm_policy_id2dir(pol->index), 1014 walk->seq, data); 1015 if (error) { 1016 list_move_tail(&walk->walk.all, &x->all); 1017 goto out; 1018 } 1019 walk->seq++; 1020 } 1021 if (walk->seq == 0) { 1022 error = -ENOENT; 1023 goto out; 1024 } 1025 list_del_init(&walk->walk.all); 1026 out: 1027 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 1028 return error; 1029 } 1030 EXPORT_SYMBOL(xfrm_policy_walk); 1031 1032 void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type) 1033 { 1034 INIT_LIST_HEAD(&walk->walk.all); 1035 walk->walk.dead = 1; 1036 walk->type = type; 1037 walk->seq = 0; 1038 } 1039 EXPORT_SYMBOL(xfrm_policy_walk_init); 1040 1041 void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net) 1042 { 1043 if (list_empty(&walk->walk.all)) 1044 return; 1045 1046 spin_lock_bh(&net->xfrm.xfrm_policy_lock); /*FIXME where is net? */ 1047 list_del(&walk->walk.all); 1048 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 1049 } 1050 EXPORT_SYMBOL(xfrm_policy_walk_done); 1051 1052 /* 1053 * Find policy to apply to this flow. 1054 * 1055 * Returns 0 if policy found, else an -errno. 1056 */ 1057 static int xfrm_policy_match(const struct xfrm_policy *pol, 1058 const struct flowi *fl, 1059 u8 type, u16 family, int dir) 1060 { 1061 const struct xfrm_selector *sel = &pol->selector; 1062 int ret = -ESRCH; 1063 bool match; 1064 1065 if (pol->family != family || 1066 (fl->flowi_mark & pol->mark.m) != pol->mark.v || 1067 pol->type != type) 1068 return ret; 1069 1070 match = xfrm_selector_match(sel, fl, family); 1071 if (match) 1072 ret = security_xfrm_policy_lookup(pol->security, fl->flowi_secid, 1073 dir); 1074 1075 return ret; 1076 } 1077 1078 static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type, 1079 const struct flowi *fl, 1080 u16 family, u8 dir) 1081 { 1082 int err; 1083 struct xfrm_policy *pol, *ret; 1084 const xfrm_address_t *daddr, *saddr; 1085 struct hlist_head *chain; 1086 unsigned int sequence; 1087 u32 priority; 1088 1089 daddr = xfrm_flowi_daddr(fl, family); 1090 saddr = xfrm_flowi_saddr(fl, family); 1091 if (unlikely(!daddr || !saddr)) 1092 return NULL; 1093 1094 rcu_read_lock(); 1095 retry: 1096 do { 1097 sequence = read_seqcount_begin(&xfrm_policy_hash_generation); 1098 chain = policy_hash_direct(net, daddr, saddr, family, dir); 1099 } while (read_seqcount_retry(&xfrm_policy_hash_generation, sequence)); 1100 1101 priority = ~0U; 1102 ret = NULL; 1103 hlist_for_each_entry_rcu(pol, chain, bydst) { 1104 err = xfrm_policy_match(pol, fl, type, family, dir); 1105 if (err) { 1106 if (err == -ESRCH) 1107 continue; 1108 else { 1109 ret = ERR_PTR(err); 1110 goto fail; 1111 } 1112 } else { 1113 ret = pol; 1114 priority = ret->priority; 1115 break; 1116 } 1117 } 1118 chain = &net->xfrm.policy_inexact[dir]; 1119 hlist_for_each_entry_rcu(pol, chain, bydst) { 1120 if ((pol->priority >= priority) && ret) 1121 break; 1122 1123 err = xfrm_policy_match(pol, fl, type, family, dir); 1124 if (err) { 1125 if (err == -ESRCH) 1126 continue; 1127 else { 1128 ret = ERR_PTR(err); 1129 goto fail; 1130 } 1131 } else { 1132 ret = pol; 1133 break; 1134 } 1135 } 1136 1137 if (read_seqcount_retry(&xfrm_policy_hash_generation, sequence)) 1138 goto retry; 1139 1140 if (ret && !xfrm_pol_hold_rcu(ret)) 1141 goto retry; 1142 fail: 1143 rcu_read_unlock(); 1144 1145 return ret; 1146 } 1147 1148 static struct xfrm_policy * 1149 xfrm_policy_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir) 1150 { 1151 #ifdef CONFIG_XFRM_SUB_POLICY 1152 struct xfrm_policy *pol; 1153 1154 pol = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_SUB, fl, family, dir); 1155 if (pol != NULL) 1156 return pol; 1157 #endif 1158 return xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, fl, family, dir); 1159 } 1160 1161 static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir, 1162 const struct flowi *fl, u16 family) 1163 { 1164 struct xfrm_policy *pol; 1165 1166 rcu_read_lock(); 1167 again: 1168 pol = rcu_dereference(sk->sk_policy[dir]); 1169 if (pol != NULL) { 1170 bool match; 1171 int err = 0; 1172 1173 if (pol->family != family) { 1174 pol = NULL; 1175 goto out; 1176 } 1177 1178 match = xfrm_selector_match(&pol->selector, fl, family); 1179 if (match) { 1180 if ((sk->sk_mark & pol->mark.m) != pol->mark.v) { 1181 pol = NULL; 1182 goto out; 1183 } 1184 err = security_xfrm_policy_lookup(pol->security, 1185 fl->flowi_secid, 1186 dir); 1187 if (!err) { 1188 if (!xfrm_pol_hold_rcu(pol)) 1189 goto again; 1190 } else if (err == -ESRCH) { 1191 pol = NULL; 1192 } else { 1193 pol = ERR_PTR(err); 1194 } 1195 } else 1196 pol = NULL; 1197 } 1198 out: 1199 rcu_read_unlock(); 1200 return pol; 1201 } 1202 1203 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir) 1204 { 1205 struct net *net = xp_net(pol); 1206 1207 list_add(&pol->walk.all, &net->xfrm.policy_all); 1208 net->xfrm.policy_count[dir]++; 1209 xfrm_pol_hold(pol); 1210 } 1211 1212 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol, 1213 int dir) 1214 { 1215 struct net *net = xp_net(pol); 1216 1217 if (list_empty(&pol->walk.all)) 1218 return NULL; 1219 1220 /* Socket policies are not hashed. */ 1221 if (!hlist_unhashed(&pol->bydst)) { 1222 hlist_del_rcu(&pol->bydst); 1223 hlist_del(&pol->byidx); 1224 } 1225 1226 list_del_init(&pol->walk.all); 1227 net->xfrm.policy_count[dir]--; 1228 1229 return pol; 1230 } 1231 1232 static void xfrm_sk_policy_link(struct xfrm_policy *pol, int dir) 1233 { 1234 __xfrm_policy_link(pol, XFRM_POLICY_MAX + dir); 1235 } 1236 1237 static void xfrm_sk_policy_unlink(struct xfrm_policy *pol, int dir) 1238 { 1239 __xfrm_policy_unlink(pol, XFRM_POLICY_MAX + dir); 1240 } 1241 1242 int xfrm_policy_delete(struct xfrm_policy *pol, int dir) 1243 { 1244 struct net *net = xp_net(pol); 1245 1246 spin_lock_bh(&net->xfrm.xfrm_policy_lock); 1247 pol = __xfrm_policy_unlink(pol, dir); 1248 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 1249 if (pol) { 1250 xfrm_policy_kill(pol); 1251 return 0; 1252 } 1253 return -ENOENT; 1254 } 1255 EXPORT_SYMBOL(xfrm_policy_delete); 1256 1257 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol) 1258 { 1259 struct net *net = sock_net(sk); 1260 struct xfrm_policy *old_pol; 1261 1262 #ifdef CONFIG_XFRM_SUB_POLICY 1263 if (pol && pol->type != XFRM_POLICY_TYPE_MAIN) 1264 return -EINVAL; 1265 #endif 1266 1267 spin_lock_bh(&net->xfrm.xfrm_policy_lock); 1268 old_pol = rcu_dereference_protected(sk->sk_policy[dir], 1269 lockdep_is_held(&net->xfrm.xfrm_policy_lock)); 1270 if (pol) { 1271 pol->curlft.add_time = get_seconds(); 1272 pol->index = xfrm_gen_index(net, XFRM_POLICY_MAX+dir, 0); 1273 xfrm_sk_policy_link(pol, dir); 1274 } 1275 rcu_assign_pointer(sk->sk_policy[dir], pol); 1276 if (old_pol) { 1277 if (pol) 1278 xfrm_policy_requeue(old_pol, pol); 1279 1280 /* Unlinking succeeds always. This is the only function 1281 * allowed to delete or replace socket policy. 1282 */ 1283 xfrm_sk_policy_unlink(old_pol, dir); 1284 } 1285 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 1286 1287 if (old_pol) { 1288 xfrm_policy_kill(old_pol); 1289 } 1290 return 0; 1291 } 1292 1293 static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir) 1294 { 1295 struct xfrm_policy *newp = xfrm_policy_alloc(xp_net(old), GFP_ATOMIC); 1296 struct net *net = xp_net(old); 1297 1298 if (newp) { 1299 newp->selector = old->selector; 1300 if (security_xfrm_policy_clone(old->security, 1301 &newp->security)) { 1302 kfree(newp); 1303 return NULL; /* ENOMEM */ 1304 } 1305 newp->lft = old->lft; 1306 newp->curlft = old->curlft; 1307 newp->mark = old->mark; 1308 newp->action = old->action; 1309 newp->flags = old->flags; 1310 newp->xfrm_nr = old->xfrm_nr; 1311 newp->index = old->index; 1312 newp->type = old->type; 1313 newp->family = old->family; 1314 memcpy(newp->xfrm_vec, old->xfrm_vec, 1315 newp->xfrm_nr*sizeof(struct xfrm_tmpl)); 1316 spin_lock_bh(&net->xfrm.xfrm_policy_lock); 1317 xfrm_sk_policy_link(newp, dir); 1318 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 1319 xfrm_pol_put(newp); 1320 } 1321 return newp; 1322 } 1323 1324 int __xfrm_sk_clone_policy(struct sock *sk, const struct sock *osk) 1325 { 1326 const struct xfrm_policy *p; 1327 struct xfrm_policy *np; 1328 int i, ret = 0; 1329 1330 rcu_read_lock(); 1331 for (i = 0; i < 2; i++) { 1332 p = rcu_dereference(osk->sk_policy[i]); 1333 if (p) { 1334 np = clone_policy(p, i); 1335 if (unlikely(!np)) { 1336 ret = -ENOMEM; 1337 break; 1338 } 1339 rcu_assign_pointer(sk->sk_policy[i], np); 1340 } 1341 } 1342 rcu_read_unlock(); 1343 return ret; 1344 } 1345 1346 static int 1347 xfrm_get_saddr(struct net *net, int oif, xfrm_address_t *local, 1348 xfrm_address_t *remote, unsigned short family, u32 mark) 1349 { 1350 int err; 1351 const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); 1352 1353 if (unlikely(afinfo == NULL)) 1354 return -EINVAL; 1355 err = afinfo->get_saddr(net, oif, local, remote, mark); 1356 rcu_read_unlock(); 1357 return err; 1358 } 1359 1360 /* Resolve list of templates for the flow, given policy. */ 1361 1362 static int 1363 xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl, 1364 struct xfrm_state **xfrm, unsigned short family) 1365 { 1366 struct net *net = xp_net(policy); 1367 int nx; 1368 int i, error; 1369 xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family); 1370 xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family); 1371 xfrm_address_t tmp; 1372 1373 for (nx = 0, i = 0; i < policy->xfrm_nr; i++) { 1374 struct xfrm_state *x; 1375 xfrm_address_t *remote = daddr; 1376 xfrm_address_t *local = saddr; 1377 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i]; 1378 1379 if (tmpl->mode == XFRM_MODE_TUNNEL || 1380 tmpl->mode == XFRM_MODE_BEET) { 1381 remote = &tmpl->id.daddr; 1382 local = &tmpl->saddr; 1383 if (xfrm_addr_any(local, tmpl->encap_family)) { 1384 error = xfrm_get_saddr(net, fl->flowi_oif, 1385 &tmp, remote, 1386 tmpl->encap_family, 0); 1387 if (error) 1388 goto fail; 1389 local = &tmp; 1390 } 1391 } 1392 1393 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family); 1394 1395 if (x && x->km.state == XFRM_STATE_VALID) { 1396 xfrm[nx++] = x; 1397 daddr = remote; 1398 saddr = local; 1399 continue; 1400 } 1401 if (x) { 1402 error = (x->km.state == XFRM_STATE_ERROR ? 1403 -EINVAL : -EAGAIN); 1404 xfrm_state_put(x); 1405 } else if (error == -ESRCH) { 1406 error = -EAGAIN; 1407 } 1408 1409 if (!tmpl->optional) 1410 goto fail; 1411 } 1412 return nx; 1413 1414 fail: 1415 for (nx--; nx >= 0; nx--) 1416 xfrm_state_put(xfrm[nx]); 1417 return error; 1418 } 1419 1420 static int 1421 xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, const struct flowi *fl, 1422 struct xfrm_state **xfrm, unsigned short family) 1423 { 1424 struct xfrm_state *tp[XFRM_MAX_DEPTH]; 1425 struct xfrm_state **tpp = (npols > 1) ? tp : xfrm; 1426 int cnx = 0; 1427 int error; 1428 int ret; 1429 int i; 1430 1431 for (i = 0; i < npols; i++) { 1432 if (cnx + pols[i]->xfrm_nr >= XFRM_MAX_DEPTH) { 1433 error = -ENOBUFS; 1434 goto fail; 1435 } 1436 1437 ret = xfrm_tmpl_resolve_one(pols[i], fl, &tpp[cnx], family); 1438 if (ret < 0) { 1439 error = ret; 1440 goto fail; 1441 } else 1442 cnx += ret; 1443 } 1444 1445 /* found states are sorted for outbound processing */ 1446 if (npols > 1) 1447 xfrm_state_sort(xfrm, tpp, cnx, family); 1448 1449 return cnx; 1450 1451 fail: 1452 for (cnx--; cnx >= 0; cnx--) 1453 xfrm_state_put(tpp[cnx]); 1454 return error; 1455 1456 } 1457 1458 static int xfrm_get_tos(const struct flowi *fl, int family) 1459 { 1460 const struct xfrm_policy_afinfo *afinfo; 1461 int tos; 1462 1463 afinfo = xfrm_policy_get_afinfo(family); 1464 if (!afinfo) 1465 return 0; 1466 1467 tos = afinfo->get_tos(fl); 1468 1469 rcu_read_unlock(); 1470 1471 return tos; 1472 } 1473 1474 static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family) 1475 { 1476 const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); 1477 struct dst_ops *dst_ops; 1478 struct xfrm_dst *xdst; 1479 1480 if (!afinfo) 1481 return ERR_PTR(-EINVAL); 1482 1483 switch (family) { 1484 case AF_INET: 1485 dst_ops = &net->xfrm.xfrm4_dst_ops; 1486 break; 1487 #if IS_ENABLED(CONFIG_IPV6) 1488 case AF_INET6: 1489 dst_ops = &net->xfrm.xfrm6_dst_ops; 1490 break; 1491 #endif 1492 default: 1493 BUG(); 1494 } 1495 xdst = dst_alloc(dst_ops, NULL, 1, DST_OBSOLETE_NONE, 0); 1496 1497 if (likely(xdst)) { 1498 struct dst_entry *dst = &xdst->u.dst; 1499 1500 memset(dst + 1, 0, sizeof(*xdst) - sizeof(*dst)); 1501 } else 1502 xdst = ERR_PTR(-ENOBUFS); 1503 1504 rcu_read_unlock(); 1505 1506 return xdst; 1507 } 1508 1509 static inline int xfrm_init_path(struct xfrm_dst *path, struct dst_entry *dst, 1510 int nfheader_len) 1511 { 1512 const struct xfrm_policy_afinfo *afinfo = 1513 xfrm_policy_get_afinfo(dst->ops->family); 1514 int err; 1515 1516 if (!afinfo) 1517 return -EINVAL; 1518 1519 err = afinfo->init_path(path, dst, nfheader_len); 1520 1521 rcu_read_unlock(); 1522 1523 return err; 1524 } 1525 1526 static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, 1527 const struct flowi *fl) 1528 { 1529 const struct xfrm_policy_afinfo *afinfo = 1530 xfrm_policy_get_afinfo(xdst->u.dst.ops->family); 1531 int err; 1532 1533 if (!afinfo) 1534 return -EINVAL; 1535 1536 err = afinfo->fill_dst(xdst, dev, fl); 1537 1538 rcu_read_unlock(); 1539 1540 return err; 1541 } 1542 1543 1544 /* Allocate chain of dst_entry's, attach known xfrm's, calculate 1545 * all the metrics... Shortly, bundle a bundle. 1546 */ 1547 1548 static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy, 1549 struct xfrm_state **xfrm, 1550 struct xfrm_dst **bundle, 1551 int nx, 1552 const struct flowi *fl, 1553 struct dst_entry *dst) 1554 { 1555 struct net *net = xp_net(policy); 1556 unsigned long now = jiffies; 1557 struct net_device *dev; 1558 struct xfrm_mode *inner_mode; 1559 struct xfrm_dst *xdst_prev = NULL; 1560 struct xfrm_dst *xdst0 = NULL; 1561 int i = 0; 1562 int err; 1563 int header_len = 0; 1564 int nfheader_len = 0; 1565 int trailer_len = 0; 1566 int tos; 1567 int family = policy->selector.family; 1568 xfrm_address_t saddr, daddr; 1569 1570 xfrm_flowi_addr_get(fl, &saddr, &daddr, family); 1571 1572 tos = xfrm_get_tos(fl, family); 1573 1574 dst_hold(dst); 1575 1576 for (; i < nx; i++) { 1577 struct xfrm_dst *xdst = xfrm_alloc_dst(net, family); 1578 struct dst_entry *dst1 = &xdst->u.dst; 1579 1580 err = PTR_ERR(xdst); 1581 if (IS_ERR(xdst)) { 1582 dst_release(dst); 1583 goto put_states; 1584 } 1585 1586 bundle[i] = xdst; 1587 if (!xdst_prev) 1588 xdst0 = xdst; 1589 else 1590 /* Ref count is taken during xfrm_alloc_dst() 1591 * No need to do dst_clone() on dst1 1592 */ 1593 xfrm_dst_set_child(xdst_prev, &xdst->u.dst); 1594 1595 if (xfrm[i]->sel.family == AF_UNSPEC) { 1596 inner_mode = xfrm_ip2inner_mode(xfrm[i], 1597 xfrm_af2proto(family)); 1598 if (!inner_mode) { 1599 err = -EAFNOSUPPORT; 1600 dst_release(dst); 1601 goto put_states; 1602 } 1603 } else 1604 inner_mode = xfrm[i]->inner_mode; 1605 1606 xdst->route = dst; 1607 dst_copy_metrics(dst1, dst); 1608 1609 if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) { 1610 family = xfrm[i]->props.family; 1611 dst = xfrm_dst_lookup(xfrm[i], tos, fl->flowi_oif, 1612 &saddr, &daddr, family, 1613 xfrm[i]->props.output_mark); 1614 err = PTR_ERR(dst); 1615 if (IS_ERR(dst)) 1616 goto put_states; 1617 } else 1618 dst_hold(dst); 1619 1620 dst1->xfrm = xfrm[i]; 1621 xdst->xfrm_genid = xfrm[i]->genid; 1622 1623 dst1->obsolete = DST_OBSOLETE_FORCE_CHK; 1624 dst1->flags |= DST_HOST; 1625 dst1->lastuse = now; 1626 1627 dst1->input = dst_discard; 1628 dst1->output = inner_mode->afinfo->output; 1629 1630 xdst_prev = xdst; 1631 1632 header_len += xfrm[i]->props.header_len; 1633 if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT) 1634 nfheader_len += xfrm[i]->props.header_len; 1635 trailer_len += xfrm[i]->props.trailer_len; 1636 } 1637 1638 xfrm_dst_set_child(xdst_prev, dst); 1639 xdst0->path = dst; 1640 1641 err = -ENODEV; 1642 dev = dst->dev; 1643 if (!dev) 1644 goto free_dst; 1645 1646 xfrm_init_path(xdst0, dst, nfheader_len); 1647 xfrm_init_pmtu(bundle, nx); 1648 1649 for (xdst_prev = xdst0; xdst_prev != (struct xfrm_dst *)dst; 1650 xdst_prev = (struct xfrm_dst *) xfrm_dst_child(&xdst_prev->u.dst)) { 1651 err = xfrm_fill_dst(xdst_prev, dev, fl); 1652 if (err) 1653 goto free_dst; 1654 1655 xdst_prev->u.dst.header_len = header_len; 1656 xdst_prev->u.dst.trailer_len = trailer_len; 1657 header_len -= xdst_prev->u.dst.xfrm->props.header_len; 1658 trailer_len -= xdst_prev->u.dst.xfrm->props.trailer_len; 1659 } 1660 1661 return &xdst0->u.dst; 1662 1663 put_states: 1664 for (; i < nx; i++) 1665 xfrm_state_put(xfrm[i]); 1666 free_dst: 1667 if (xdst0) 1668 dst_release_immediate(&xdst0->u.dst); 1669 1670 return ERR_PTR(err); 1671 } 1672 1673 static int xfrm_expand_policies(const struct flowi *fl, u16 family, 1674 struct xfrm_policy **pols, 1675 int *num_pols, int *num_xfrms) 1676 { 1677 int i; 1678 1679 if (*num_pols == 0 || !pols[0]) { 1680 *num_pols = 0; 1681 *num_xfrms = 0; 1682 return 0; 1683 } 1684 if (IS_ERR(pols[0])) 1685 return PTR_ERR(pols[0]); 1686 1687 *num_xfrms = pols[0]->xfrm_nr; 1688 1689 #ifdef CONFIG_XFRM_SUB_POLICY 1690 if (pols[0] && pols[0]->action == XFRM_POLICY_ALLOW && 1691 pols[0]->type != XFRM_POLICY_TYPE_MAIN) { 1692 pols[1] = xfrm_policy_lookup_bytype(xp_net(pols[0]), 1693 XFRM_POLICY_TYPE_MAIN, 1694 fl, family, 1695 XFRM_POLICY_OUT); 1696 if (pols[1]) { 1697 if (IS_ERR(pols[1])) { 1698 xfrm_pols_put(pols, *num_pols); 1699 return PTR_ERR(pols[1]); 1700 } 1701 (*num_pols)++; 1702 (*num_xfrms) += pols[1]->xfrm_nr; 1703 } 1704 } 1705 #endif 1706 for (i = 0; i < *num_pols; i++) { 1707 if (pols[i]->action != XFRM_POLICY_ALLOW) { 1708 *num_xfrms = -1; 1709 break; 1710 } 1711 } 1712 1713 return 0; 1714 1715 } 1716 1717 static void xfrm_last_dst_update(struct xfrm_dst *xdst, struct xfrm_dst *old) 1718 { 1719 this_cpu_write(xfrm_last_dst, xdst); 1720 if (old) 1721 dst_release(&old->u.dst); 1722 } 1723 1724 static void __xfrm_pcpu_work_fn(void) 1725 { 1726 struct xfrm_dst *old; 1727 1728 old = this_cpu_read(xfrm_last_dst); 1729 if (old && !xfrm_bundle_ok(old)) 1730 xfrm_last_dst_update(NULL, old); 1731 } 1732 1733 static void xfrm_pcpu_work_fn(struct work_struct *work) 1734 { 1735 local_bh_disable(); 1736 rcu_read_lock(); 1737 __xfrm_pcpu_work_fn(); 1738 rcu_read_unlock(); 1739 local_bh_enable(); 1740 } 1741 1742 void xfrm_policy_cache_flush(void) 1743 { 1744 struct xfrm_dst *old; 1745 bool found = false; 1746 int cpu; 1747 1748 might_sleep(); 1749 1750 local_bh_disable(); 1751 rcu_read_lock(); 1752 for_each_possible_cpu(cpu) { 1753 old = per_cpu(xfrm_last_dst, cpu); 1754 if (old && !xfrm_bundle_ok(old)) { 1755 if (smp_processor_id() == cpu) { 1756 __xfrm_pcpu_work_fn(); 1757 continue; 1758 } 1759 found = true; 1760 break; 1761 } 1762 } 1763 1764 rcu_read_unlock(); 1765 local_bh_enable(); 1766 1767 if (!found) 1768 return; 1769 1770 get_online_cpus(); 1771 1772 for_each_possible_cpu(cpu) { 1773 bool bundle_release; 1774 1775 rcu_read_lock(); 1776 old = per_cpu(xfrm_last_dst, cpu); 1777 bundle_release = old && !xfrm_bundle_ok(old); 1778 rcu_read_unlock(); 1779 1780 if (!bundle_release) 1781 continue; 1782 1783 if (cpu_online(cpu)) { 1784 schedule_work_on(cpu, &xfrm_pcpu_work[cpu]); 1785 continue; 1786 } 1787 1788 rcu_read_lock(); 1789 old = per_cpu(xfrm_last_dst, cpu); 1790 if (old && !xfrm_bundle_ok(old)) { 1791 per_cpu(xfrm_last_dst, cpu) = NULL; 1792 dst_release(&old->u.dst); 1793 } 1794 rcu_read_unlock(); 1795 } 1796 1797 put_online_cpus(); 1798 } 1799 1800 static bool xfrm_xdst_can_reuse(struct xfrm_dst *xdst, 1801 struct xfrm_state * const xfrm[], 1802 int num) 1803 { 1804 const struct dst_entry *dst = &xdst->u.dst; 1805 int i; 1806 1807 if (xdst->num_xfrms != num) 1808 return false; 1809 1810 for (i = 0; i < num; i++) { 1811 if (!dst || dst->xfrm != xfrm[i]) 1812 return false; 1813 dst = xfrm_dst_child(dst); 1814 } 1815 1816 return xfrm_bundle_ok(xdst); 1817 } 1818 1819 static struct xfrm_dst * 1820 xfrm_resolve_and_create_bundle(struct xfrm_policy **pols, int num_pols, 1821 const struct flowi *fl, u16 family, 1822 struct dst_entry *dst_orig) 1823 { 1824 struct net *net = xp_net(pols[0]); 1825 struct xfrm_state *xfrm[XFRM_MAX_DEPTH]; 1826 struct xfrm_dst *bundle[XFRM_MAX_DEPTH]; 1827 struct xfrm_dst *xdst, *old; 1828 struct dst_entry *dst; 1829 int err; 1830 1831 /* Try to instantiate a bundle */ 1832 err = xfrm_tmpl_resolve(pols, num_pols, fl, xfrm, family); 1833 if (err <= 0) { 1834 if (err != 0 && err != -EAGAIN) 1835 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR); 1836 return ERR_PTR(err); 1837 } 1838 1839 xdst = this_cpu_read(xfrm_last_dst); 1840 if (xdst && 1841 xdst->u.dst.dev == dst_orig->dev && 1842 xdst->num_pols == num_pols && 1843 memcmp(xdst->pols, pols, 1844 sizeof(struct xfrm_policy *) * num_pols) == 0 && 1845 xfrm_xdst_can_reuse(xdst, xfrm, err)) { 1846 dst_hold(&xdst->u.dst); 1847 xfrm_pols_put(pols, num_pols); 1848 while (err > 0) 1849 xfrm_state_put(xfrm[--err]); 1850 return xdst; 1851 } 1852 1853 old = xdst; 1854 1855 dst = xfrm_bundle_create(pols[0], xfrm, bundle, err, fl, dst_orig); 1856 if (IS_ERR(dst)) { 1857 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTBUNDLEGENERROR); 1858 return ERR_CAST(dst); 1859 } 1860 1861 xdst = (struct xfrm_dst *)dst; 1862 xdst->num_xfrms = err; 1863 xdst->num_pols = num_pols; 1864 memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols); 1865 xdst->policy_genid = atomic_read(&pols[0]->genid); 1866 1867 atomic_set(&xdst->u.dst.__refcnt, 2); 1868 xfrm_last_dst_update(xdst, old); 1869 1870 return xdst; 1871 } 1872 1873 static void xfrm_policy_queue_process(struct timer_list *t) 1874 { 1875 struct sk_buff *skb; 1876 struct sock *sk; 1877 struct dst_entry *dst; 1878 struct xfrm_policy *pol = from_timer(pol, t, polq.hold_timer); 1879 struct net *net = xp_net(pol); 1880 struct xfrm_policy_queue *pq = &pol->polq; 1881 struct flowi fl; 1882 struct sk_buff_head list; 1883 1884 spin_lock(&pq->hold_queue.lock); 1885 skb = skb_peek(&pq->hold_queue); 1886 if (!skb) { 1887 spin_unlock(&pq->hold_queue.lock); 1888 goto out; 1889 } 1890 dst = skb_dst(skb); 1891 sk = skb->sk; 1892 xfrm_decode_session(skb, &fl, dst->ops->family); 1893 spin_unlock(&pq->hold_queue.lock); 1894 1895 dst_hold(xfrm_dst_path(dst)); 1896 dst = xfrm_lookup(net, xfrm_dst_path(dst), &fl, sk, XFRM_LOOKUP_QUEUE); 1897 if (IS_ERR(dst)) 1898 goto purge_queue; 1899 1900 if (dst->flags & DST_XFRM_QUEUE) { 1901 dst_release(dst); 1902 1903 if (pq->timeout >= XFRM_QUEUE_TMO_MAX) 1904 goto purge_queue; 1905 1906 pq->timeout = pq->timeout << 1; 1907 if (!mod_timer(&pq->hold_timer, jiffies + pq->timeout)) 1908 xfrm_pol_hold(pol); 1909 goto out; 1910 } 1911 1912 dst_release(dst); 1913 1914 __skb_queue_head_init(&list); 1915 1916 spin_lock(&pq->hold_queue.lock); 1917 pq->timeout = 0; 1918 skb_queue_splice_init(&pq->hold_queue, &list); 1919 spin_unlock(&pq->hold_queue.lock); 1920 1921 while (!skb_queue_empty(&list)) { 1922 skb = __skb_dequeue(&list); 1923 1924 xfrm_decode_session(skb, &fl, skb_dst(skb)->ops->family); 1925 dst_hold(xfrm_dst_path(skb_dst(skb))); 1926 dst = xfrm_lookup(net, xfrm_dst_path(skb_dst(skb)), &fl, skb->sk, 0); 1927 if (IS_ERR(dst)) { 1928 kfree_skb(skb); 1929 continue; 1930 } 1931 1932 nf_reset(skb); 1933 skb_dst_drop(skb); 1934 skb_dst_set(skb, dst); 1935 1936 dst_output(net, skb->sk, skb); 1937 } 1938 1939 out: 1940 xfrm_pol_put(pol); 1941 return; 1942 1943 purge_queue: 1944 pq->timeout = 0; 1945 skb_queue_purge(&pq->hold_queue); 1946 xfrm_pol_put(pol); 1947 } 1948 1949 static int xdst_queue_output(struct net *net, struct sock *sk, struct sk_buff *skb) 1950 { 1951 unsigned long sched_next; 1952 struct dst_entry *dst = skb_dst(skb); 1953 struct xfrm_dst *xdst = (struct xfrm_dst *) dst; 1954 struct xfrm_policy *pol = xdst->pols[0]; 1955 struct xfrm_policy_queue *pq = &pol->polq; 1956 1957 if (unlikely(skb_fclone_busy(sk, skb))) { 1958 kfree_skb(skb); 1959 return 0; 1960 } 1961 1962 if (pq->hold_queue.qlen > XFRM_MAX_QUEUE_LEN) { 1963 kfree_skb(skb); 1964 return -EAGAIN; 1965 } 1966 1967 skb_dst_force(skb); 1968 1969 spin_lock_bh(&pq->hold_queue.lock); 1970 1971 if (!pq->timeout) 1972 pq->timeout = XFRM_QUEUE_TMO_MIN; 1973 1974 sched_next = jiffies + pq->timeout; 1975 1976 if (del_timer(&pq->hold_timer)) { 1977 if (time_before(pq->hold_timer.expires, sched_next)) 1978 sched_next = pq->hold_timer.expires; 1979 xfrm_pol_put(pol); 1980 } 1981 1982 __skb_queue_tail(&pq->hold_queue, skb); 1983 if (!mod_timer(&pq->hold_timer, sched_next)) 1984 xfrm_pol_hold(pol); 1985 1986 spin_unlock_bh(&pq->hold_queue.lock); 1987 1988 return 0; 1989 } 1990 1991 static struct xfrm_dst *xfrm_create_dummy_bundle(struct net *net, 1992 struct xfrm_flo *xflo, 1993 const struct flowi *fl, 1994 int num_xfrms, 1995 u16 family) 1996 { 1997 int err; 1998 struct net_device *dev; 1999 struct dst_entry *dst; 2000 struct dst_entry *dst1; 2001 struct xfrm_dst *xdst; 2002 2003 xdst = xfrm_alloc_dst(net, family); 2004 if (IS_ERR(xdst)) 2005 return xdst; 2006 2007 if (!(xflo->flags & XFRM_LOOKUP_QUEUE) || 2008 net->xfrm.sysctl_larval_drop || 2009 num_xfrms <= 0) 2010 return xdst; 2011 2012 dst = xflo->dst_orig; 2013 dst1 = &xdst->u.dst; 2014 dst_hold(dst); 2015 xdst->route = dst; 2016 2017 dst_copy_metrics(dst1, dst); 2018 2019 dst1->obsolete = DST_OBSOLETE_FORCE_CHK; 2020 dst1->flags |= DST_HOST | DST_XFRM_QUEUE; 2021 dst1->lastuse = jiffies; 2022 2023 dst1->input = dst_discard; 2024 dst1->output = xdst_queue_output; 2025 2026 dst_hold(dst); 2027 xfrm_dst_set_child(xdst, dst); 2028 xdst->path = dst; 2029 2030 xfrm_init_path((struct xfrm_dst *)dst1, dst, 0); 2031 2032 err = -ENODEV; 2033 dev = dst->dev; 2034 if (!dev) 2035 goto free_dst; 2036 2037 err = xfrm_fill_dst(xdst, dev, fl); 2038 if (err) 2039 goto free_dst; 2040 2041 out: 2042 return xdst; 2043 2044 free_dst: 2045 dst_release(dst1); 2046 xdst = ERR_PTR(err); 2047 goto out; 2048 } 2049 2050 static struct xfrm_dst * 2051 xfrm_bundle_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir, struct xfrm_flo *xflo) 2052 { 2053 struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX]; 2054 int num_pols = 0, num_xfrms = 0, err; 2055 struct xfrm_dst *xdst; 2056 2057 /* Resolve policies to use if we couldn't get them from 2058 * previous cache entry */ 2059 num_pols = 1; 2060 pols[0] = xfrm_policy_lookup(net, fl, family, dir); 2061 err = xfrm_expand_policies(fl, family, pols, 2062 &num_pols, &num_xfrms); 2063 if (err < 0) 2064 goto inc_error; 2065 if (num_pols == 0) 2066 return NULL; 2067 if (num_xfrms <= 0) 2068 goto make_dummy_bundle; 2069 2070 local_bh_disable(); 2071 xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family, 2072 xflo->dst_orig); 2073 local_bh_enable(); 2074 2075 if (IS_ERR(xdst)) { 2076 err = PTR_ERR(xdst); 2077 if (err != -EAGAIN) 2078 goto error; 2079 goto make_dummy_bundle; 2080 } else if (xdst == NULL) { 2081 num_xfrms = 0; 2082 goto make_dummy_bundle; 2083 } 2084 2085 return xdst; 2086 2087 make_dummy_bundle: 2088 /* We found policies, but there's no bundles to instantiate: 2089 * either because the policy blocks, has no transformations or 2090 * we could not build template (no xfrm_states).*/ 2091 xdst = xfrm_create_dummy_bundle(net, xflo, fl, num_xfrms, family); 2092 if (IS_ERR(xdst)) { 2093 xfrm_pols_put(pols, num_pols); 2094 return ERR_CAST(xdst); 2095 } 2096 xdst->num_pols = num_pols; 2097 xdst->num_xfrms = num_xfrms; 2098 memcpy(xdst->pols, pols, sizeof(struct xfrm_policy *) * num_pols); 2099 2100 return xdst; 2101 2102 inc_error: 2103 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLERROR); 2104 error: 2105 xfrm_pols_put(pols, num_pols); 2106 return ERR_PTR(err); 2107 } 2108 2109 static struct dst_entry *make_blackhole(struct net *net, u16 family, 2110 struct dst_entry *dst_orig) 2111 { 2112 const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); 2113 struct dst_entry *ret; 2114 2115 if (!afinfo) { 2116 dst_release(dst_orig); 2117 return ERR_PTR(-EINVAL); 2118 } else { 2119 ret = afinfo->blackhole_route(net, dst_orig); 2120 } 2121 rcu_read_unlock(); 2122 2123 return ret; 2124 } 2125 2126 /* Main function: finds/creates a bundle for given flow. 2127 * 2128 * At the moment we eat a raw IP route. Mostly to speed up lookups 2129 * on interfaces with disabled IPsec. 2130 */ 2131 struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig, 2132 const struct flowi *fl, 2133 const struct sock *sk, int flags) 2134 { 2135 struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX]; 2136 struct xfrm_dst *xdst; 2137 struct dst_entry *dst, *route; 2138 u16 family = dst_orig->ops->family; 2139 u8 dir = XFRM_POLICY_OUT; 2140 int i, err, num_pols, num_xfrms = 0, drop_pols = 0; 2141 2142 dst = NULL; 2143 xdst = NULL; 2144 route = NULL; 2145 2146 sk = sk_const_to_full_sk(sk); 2147 if (sk && sk->sk_policy[XFRM_POLICY_OUT]) { 2148 num_pols = 1; 2149 pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, family); 2150 err = xfrm_expand_policies(fl, family, pols, 2151 &num_pols, &num_xfrms); 2152 if (err < 0) 2153 goto dropdst; 2154 2155 if (num_pols) { 2156 if (num_xfrms <= 0) { 2157 drop_pols = num_pols; 2158 goto no_transform; 2159 } 2160 2161 local_bh_disable(); 2162 xdst = xfrm_resolve_and_create_bundle( 2163 pols, num_pols, fl, 2164 family, dst_orig); 2165 local_bh_enable(); 2166 2167 if (IS_ERR(xdst)) { 2168 xfrm_pols_put(pols, num_pols); 2169 err = PTR_ERR(xdst); 2170 goto dropdst; 2171 } else if (xdst == NULL) { 2172 num_xfrms = 0; 2173 drop_pols = num_pols; 2174 goto no_transform; 2175 } 2176 2177 route = xdst->route; 2178 } 2179 } 2180 2181 if (xdst == NULL) { 2182 struct xfrm_flo xflo; 2183 2184 xflo.dst_orig = dst_orig; 2185 xflo.flags = flags; 2186 2187 /* To accelerate a bit... */ 2188 if ((dst_orig->flags & DST_NOXFRM) || 2189 !net->xfrm.policy_count[XFRM_POLICY_OUT]) 2190 goto nopol; 2191 2192 xdst = xfrm_bundle_lookup(net, fl, family, dir, &xflo); 2193 if (xdst == NULL) 2194 goto nopol; 2195 if (IS_ERR(xdst)) { 2196 err = PTR_ERR(xdst); 2197 goto dropdst; 2198 } 2199 2200 num_pols = xdst->num_pols; 2201 num_xfrms = xdst->num_xfrms; 2202 memcpy(pols, xdst->pols, sizeof(struct xfrm_policy *) * num_pols); 2203 route = xdst->route; 2204 } 2205 2206 dst = &xdst->u.dst; 2207 if (route == NULL && num_xfrms > 0) { 2208 /* The only case when xfrm_bundle_lookup() returns a 2209 * bundle with null route, is when the template could 2210 * not be resolved. It means policies are there, but 2211 * bundle could not be created, since we don't yet 2212 * have the xfrm_state's. We need to wait for KM to 2213 * negotiate new SA's or bail out with error.*/ 2214 if (net->xfrm.sysctl_larval_drop) { 2215 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES); 2216 err = -EREMOTE; 2217 goto error; 2218 } 2219 2220 err = -EAGAIN; 2221 2222 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES); 2223 goto error; 2224 } 2225 2226 no_transform: 2227 if (num_pols == 0) 2228 goto nopol; 2229 2230 if ((flags & XFRM_LOOKUP_ICMP) && 2231 !(pols[0]->flags & XFRM_POLICY_ICMP)) { 2232 err = -ENOENT; 2233 goto error; 2234 } 2235 2236 for (i = 0; i < num_pols; i++) 2237 pols[i]->curlft.use_time = get_seconds(); 2238 2239 if (num_xfrms < 0) { 2240 /* Prohibit the flow */ 2241 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTPOLBLOCK); 2242 err = -EPERM; 2243 goto error; 2244 } else if (num_xfrms > 0) { 2245 /* Flow transformed */ 2246 dst_release(dst_orig); 2247 } else { 2248 /* Flow passes untransformed */ 2249 dst_release(dst); 2250 dst = dst_orig; 2251 } 2252 ok: 2253 xfrm_pols_put(pols, drop_pols); 2254 if (dst && dst->xfrm && 2255 dst->xfrm->props.mode == XFRM_MODE_TUNNEL) 2256 dst->flags |= DST_XFRM_TUNNEL; 2257 return dst; 2258 2259 nopol: 2260 if (!(flags & XFRM_LOOKUP_ICMP)) { 2261 dst = dst_orig; 2262 goto ok; 2263 } 2264 err = -ENOENT; 2265 error: 2266 dst_release(dst); 2267 dropdst: 2268 if (!(flags & XFRM_LOOKUP_KEEP_DST_REF)) 2269 dst_release(dst_orig); 2270 xfrm_pols_put(pols, drop_pols); 2271 return ERR_PTR(err); 2272 } 2273 EXPORT_SYMBOL(xfrm_lookup); 2274 2275 /* Callers of xfrm_lookup_route() must ensure a call to dst_output(). 2276 * Otherwise we may send out blackholed packets. 2277 */ 2278 struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig, 2279 const struct flowi *fl, 2280 const struct sock *sk, int flags) 2281 { 2282 struct dst_entry *dst = xfrm_lookup(net, dst_orig, fl, sk, 2283 flags | XFRM_LOOKUP_QUEUE | 2284 XFRM_LOOKUP_KEEP_DST_REF); 2285 2286 if (IS_ERR(dst) && PTR_ERR(dst) == -EREMOTE) 2287 return make_blackhole(net, dst_orig->ops->family, dst_orig); 2288 2289 return dst; 2290 } 2291 EXPORT_SYMBOL(xfrm_lookup_route); 2292 2293 static inline int 2294 xfrm_secpath_reject(int idx, struct sk_buff *skb, const struct flowi *fl) 2295 { 2296 struct xfrm_state *x; 2297 2298 if (!skb->sp || idx < 0 || idx >= skb->sp->len) 2299 return 0; 2300 x = skb->sp->xvec[idx]; 2301 if (!x->type->reject) 2302 return 0; 2303 return x->type->reject(x, skb, fl); 2304 } 2305 2306 /* When skb is transformed back to its "native" form, we have to 2307 * check policy restrictions. At the moment we make this in maximally 2308 * stupid way. Shame on me. :-) Of course, connected sockets must 2309 * have policy cached at them. 2310 */ 2311 2312 static inline int 2313 xfrm_state_ok(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x, 2314 unsigned short family) 2315 { 2316 if (xfrm_state_kern(x)) 2317 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, tmpl->encap_family); 2318 return x->id.proto == tmpl->id.proto && 2319 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) && 2320 (x->props.reqid == tmpl->reqid || !tmpl->reqid) && 2321 x->props.mode == tmpl->mode && 2322 (tmpl->allalgs || (tmpl->aalgos & (1<<x->props.aalgo)) || 2323 !(xfrm_id_proto_match(tmpl->id.proto, IPSEC_PROTO_ANY))) && 2324 !(x->props.mode != XFRM_MODE_TRANSPORT && 2325 xfrm_state_addr_cmp(tmpl, x, family)); 2326 } 2327 2328 /* 2329 * 0 or more than 0 is returned when validation is succeeded (either bypass 2330 * because of optional transport mode, or next index of the mathced secpath 2331 * state with the template. 2332 * -1 is returned when no matching template is found. 2333 * Otherwise "-2 - errored_index" is returned. 2334 */ 2335 static inline int 2336 xfrm_policy_ok(const struct xfrm_tmpl *tmpl, const struct sec_path *sp, int start, 2337 unsigned short family) 2338 { 2339 int idx = start; 2340 2341 if (tmpl->optional) { 2342 if (tmpl->mode == XFRM_MODE_TRANSPORT) 2343 return start; 2344 } else 2345 start = -1; 2346 for (; idx < sp->len; idx++) { 2347 if (xfrm_state_ok(tmpl, sp->xvec[idx], family)) 2348 return ++idx; 2349 if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) { 2350 if (start == -1) 2351 start = -2-idx; 2352 break; 2353 } 2354 } 2355 return start; 2356 } 2357 2358 int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl, 2359 unsigned int family, int reverse) 2360 { 2361 const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); 2362 int err; 2363 2364 if (unlikely(afinfo == NULL)) 2365 return -EAFNOSUPPORT; 2366 2367 afinfo->decode_session(skb, fl, reverse); 2368 err = security_xfrm_decode_session(skb, &fl->flowi_secid); 2369 rcu_read_unlock(); 2370 return err; 2371 } 2372 EXPORT_SYMBOL(__xfrm_decode_session); 2373 2374 static inline int secpath_has_nontransport(const struct sec_path *sp, int k, int *idxp) 2375 { 2376 for (; k < sp->len; k++) { 2377 if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) { 2378 *idxp = k; 2379 return 1; 2380 } 2381 } 2382 2383 return 0; 2384 } 2385 2386 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, 2387 unsigned short family) 2388 { 2389 struct net *net = dev_net(skb->dev); 2390 struct xfrm_policy *pol; 2391 struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX]; 2392 int npols = 0; 2393 int xfrm_nr; 2394 int pi; 2395 int reverse; 2396 struct flowi fl; 2397 int xerr_idx = -1; 2398 2399 reverse = dir & ~XFRM_POLICY_MASK; 2400 dir &= XFRM_POLICY_MASK; 2401 2402 if (__xfrm_decode_session(skb, &fl, family, reverse) < 0) { 2403 XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR); 2404 return 0; 2405 } 2406 2407 nf_nat_decode_session(skb, &fl, family); 2408 2409 /* First, check used SA against their selectors. */ 2410 if (skb->sp) { 2411 int i; 2412 2413 for (i = skb->sp->len-1; i >= 0; i--) { 2414 struct xfrm_state *x = skb->sp->xvec[i]; 2415 if (!xfrm_selector_match(&x->sel, &fl, family)) { 2416 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH); 2417 return 0; 2418 } 2419 } 2420 } 2421 2422 pol = NULL; 2423 sk = sk_to_full_sk(sk); 2424 if (sk && sk->sk_policy[dir]) { 2425 pol = xfrm_sk_policy_lookup(sk, dir, &fl, family); 2426 if (IS_ERR(pol)) { 2427 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR); 2428 return 0; 2429 } 2430 } 2431 2432 if (!pol) 2433 pol = xfrm_policy_lookup(net, &fl, family, dir); 2434 2435 if (IS_ERR(pol)) { 2436 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR); 2437 return 0; 2438 } 2439 2440 if (!pol) { 2441 if (skb->sp && secpath_has_nontransport(skb->sp, 0, &xerr_idx)) { 2442 xfrm_secpath_reject(xerr_idx, skb, &fl); 2443 XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS); 2444 return 0; 2445 } 2446 return 1; 2447 } 2448 2449 pol->curlft.use_time = get_seconds(); 2450 2451 pols[0] = pol; 2452 npols++; 2453 #ifdef CONFIG_XFRM_SUB_POLICY 2454 if (pols[0]->type != XFRM_POLICY_TYPE_MAIN) { 2455 pols[1] = xfrm_policy_lookup_bytype(net, XFRM_POLICY_TYPE_MAIN, 2456 &fl, family, 2457 XFRM_POLICY_IN); 2458 if (pols[1]) { 2459 if (IS_ERR(pols[1])) { 2460 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLERROR); 2461 return 0; 2462 } 2463 pols[1]->curlft.use_time = get_seconds(); 2464 npols++; 2465 } 2466 } 2467 #endif 2468 2469 if (pol->action == XFRM_POLICY_ALLOW) { 2470 struct sec_path *sp; 2471 static struct sec_path dummy; 2472 struct xfrm_tmpl *tp[XFRM_MAX_DEPTH]; 2473 struct xfrm_tmpl *stp[XFRM_MAX_DEPTH]; 2474 struct xfrm_tmpl **tpp = tp; 2475 int ti = 0; 2476 int i, k; 2477 2478 if ((sp = skb->sp) == NULL) 2479 sp = &dummy; 2480 2481 for (pi = 0; pi < npols; pi++) { 2482 if (pols[pi] != pol && 2483 pols[pi]->action != XFRM_POLICY_ALLOW) { 2484 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK); 2485 goto reject; 2486 } 2487 if (ti + pols[pi]->xfrm_nr >= XFRM_MAX_DEPTH) { 2488 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR); 2489 goto reject_error; 2490 } 2491 for (i = 0; i < pols[pi]->xfrm_nr; i++) 2492 tpp[ti++] = &pols[pi]->xfrm_vec[i]; 2493 } 2494 xfrm_nr = ti; 2495 if (npols > 1) { 2496 xfrm_tmpl_sort(stp, tpp, xfrm_nr, family, net); 2497 tpp = stp; 2498 } 2499 2500 /* For each tunnel xfrm, find the first matching tmpl. 2501 * For each tmpl before that, find corresponding xfrm. 2502 * Order is _important_. Later we will implement 2503 * some barriers, but at the moment barriers 2504 * are implied between each two transformations. 2505 */ 2506 for (i = xfrm_nr-1, k = 0; i >= 0; i--) { 2507 k = xfrm_policy_ok(tpp[i], sp, k, family); 2508 if (k < 0) { 2509 if (k < -1) 2510 /* "-2 - errored_index" returned */ 2511 xerr_idx = -(2+k); 2512 XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH); 2513 goto reject; 2514 } 2515 } 2516 2517 if (secpath_has_nontransport(sp, k, &xerr_idx)) { 2518 XFRM_INC_STATS(net, LINUX_MIB_XFRMINTMPLMISMATCH); 2519 goto reject; 2520 } 2521 2522 xfrm_pols_put(pols, npols); 2523 return 1; 2524 } 2525 XFRM_INC_STATS(net, LINUX_MIB_XFRMINPOLBLOCK); 2526 2527 reject: 2528 xfrm_secpath_reject(xerr_idx, skb, &fl); 2529 reject_error: 2530 xfrm_pols_put(pols, npols); 2531 return 0; 2532 } 2533 EXPORT_SYMBOL(__xfrm_policy_check); 2534 2535 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family) 2536 { 2537 struct net *net = dev_net(skb->dev); 2538 struct flowi fl; 2539 struct dst_entry *dst; 2540 int res = 1; 2541 2542 if (xfrm_decode_session(skb, &fl, family) < 0) { 2543 XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR); 2544 return 0; 2545 } 2546 2547 skb_dst_force(skb); 2548 2549 dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, XFRM_LOOKUP_QUEUE); 2550 if (IS_ERR(dst)) { 2551 res = 0; 2552 dst = NULL; 2553 } 2554 skb_dst_set(skb, dst); 2555 return res; 2556 } 2557 EXPORT_SYMBOL(__xfrm_route_forward); 2558 2559 /* Optimize later using cookies and generation ids. */ 2560 2561 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie) 2562 { 2563 /* Code (such as __xfrm4_bundle_create()) sets dst->obsolete 2564 * to DST_OBSOLETE_FORCE_CHK to force all XFRM destinations to 2565 * get validated by dst_ops->check on every use. We do this 2566 * because when a normal route referenced by an XFRM dst is 2567 * obsoleted we do not go looking around for all parent 2568 * referencing XFRM dsts so that we can invalidate them. It 2569 * is just too much work. Instead we make the checks here on 2570 * every use. For example: 2571 * 2572 * XFRM dst A --> IPv4 dst X 2573 * 2574 * X is the "xdst->route" of A (X is also the "dst->path" of A 2575 * in this example). If X is marked obsolete, "A" will not 2576 * notice. That's what we are validating here via the 2577 * stale_bundle() check. 2578 * 2579 * When a dst is removed from the fib tree, DST_OBSOLETE_DEAD will 2580 * be marked on it. 2581 * This will force stale_bundle() to fail on any xdst bundle with 2582 * this dst linked in it. 2583 */ 2584 if (dst->obsolete < 0 && !stale_bundle(dst)) 2585 return dst; 2586 2587 return NULL; 2588 } 2589 2590 static int stale_bundle(struct dst_entry *dst) 2591 { 2592 return !xfrm_bundle_ok((struct xfrm_dst *)dst); 2593 } 2594 2595 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev) 2596 { 2597 while ((dst = xfrm_dst_child(dst)) && dst->xfrm && dst->dev == dev) { 2598 dst->dev = dev_net(dev)->loopback_dev; 2599 dev_hold(dst->dev); 2600 dev_put(dev); 2601 } 2602 } 2603 EXPORT_SYMBOL(xfrm_dst_ifdown); 2604 2605 static void xfrm_link_failure(struct sk_buff *skb) 2606 { 2607 /* Impossible. Such dst must be popped before reaches point of failure. */ 2608 } 2609 2610 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst) 2611 { 2612 if (dst) { 2613 if (dst->obsolete) { 2614 dst_release(dst); 2615 dst = NULL; 2616 } 2617 } 2618 return dst; 2619 } 2620 2621 static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr) 2622 { 2623 while (nr--) { 2624 struct xfrm_dst *xdst = bundle[nr]; 2625 u32 pmtu, route_mtu_cached; 2626 struct dst_entry *dst; 2627 2628 dst = &xdst->u.dst; 2629 pmtu = dst_mtu(xfrm_dst_child(dst)); 2630 xdst->child_mtu_cached = pmtu; 2631 2632 pmtu = xfrm_state_mtu(dst->xfrm, pmtu); 2633 2634 route_mtu_cached = dst_mtu(xdst->route); 2635 xdst->route_mtu_cached = route_mtu_cached; 2636 2637 if (pmtu > route_mtu_cached) 2638 pmtu = route_mtu_cached; 2639 2640 dst_metric_set(dst, RTAX_MTU, pmtu); 2641 } 2642 } 2643 2644 /* Check that the bundle accepts the flow and its components are 2645 * still valid. 2646 */ 2647 2648 static int xfrm_bundle_ok(struct xfrm_dst *first) 2649 { 2650 struct xfrm_dst *bundle[XFRM_MAX_DEPTH]; 2651 struct dst_entry *dst = &first->u.dst; 2652 struct xfrm_dst *xdst; 2653 int start_from, nr; 2654 u32 mtu; 2655 2656 if (!dst_check(xfrm_dst_path(dst), ((struct xfrm_dst *)dst)->path_cookie) || 2657 (dst->dev && !netif_running(dst->dev))) 2658 return 0; 2659 2660 if (dst->flags & DST_XFRM_QUEUE) 2661 return 1; 2662 2663 start_from = nr = 0; 2664 do { 2665 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 2666 2667 if (dst->xfrm->km.state != XFRM_STATE_VALID) 2668 return 0; 2669 if (xdst->xfrm_genid != dst->xfrm->genid) 2670 return 0; 2671 if (xdst->num_pols > 0 && 2672 xdst->policy_genid != atomic_read(&xdst->pols[0]->genid)) 2673 return 0; 2674 2675 bundle[nr++] = xdst; 2676 2677 mtu = dst_mtu(xfrm_dst_child(dst)); 2678 if (xdst->child_mtu_cached != mtu) { 2679 start_from = nr; 2680 xdst->child_mtu_cached = mtu; 2681 } 2682 2683 if (!dst_check(xdst->route, xdst->route_cookie)) 2684 return 0; 2685 mtu = dst_mtu(xdst->route); 2686 if (xdst->route_mtu_cached != mtu) { 2687 start_from = nr; 2688 xdst->route_mtu_cached = mtu; 2689 } 2690 2691 dst = xfrm_dst_child(dst); 2692 } while (dst->xfrm); 2693 2694 if (likely(!start_from)) 2695 return 1; 2696 2697 xdst = bundle[start_from - 1]; 2698 mtu = xdst->child_mtu_cached; 2699 while (start_from--) { 2700 dst = &xdst->u.dst; 2701 2702 mtu = xfrm_state_mtu(dst->xfrm, mtu); 2703 if (mtu > xdst->route_mtu_cached) 2704 mtu = xdst->route_mtu_cached; 2705 dst_metric_set(dst, RTAX_MTU, mtu); 2706 if (!start_from) 2707 break; 2708 2709 xdst = bundle[start_from - 1]; 2710 xdst->child_mtu_cached = mtu; 2711 } 2712 2713 return 1; 2714 } 2715 2716 static unsigned int xfrm_default_advmss(const struct dst_entry *dst) 2717 { 2718 return dst_metric_advmss(xfrm_dst_path(dst)); 2719 } 2720 2721 static unsigned int xfrm_mtu(const struct dst_entry *dst) 2722 { 2723 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 2724 2725 return mtu ? : dst_mtu(xfrm_dst_path(dst)); 2726 } 2727 2728 static const void *xfrm_get_dst_nexthop(const struct dst_entry *dst, 2729 const void *daddr) 2730 { 2731 while (dst->xfrm) { 2732 const struct xfrm_state *xfrm = dst->xfrm; 2733 2734 dst = xfrm_dst_child(dst); 2735 2736 if (xfrm->props.mode == XFRM_MODE_TRANSPORT) 2737 continue; 2738 if (xfrm->type->flags & XFRM_TYPE_REMOTE_COADDR) 2739 daddr = xfrm->coaddr; 2740 else if (!(xfrm->type->flags & XFRM_TYPE_LOCAL_COADDR)) 2741 daddr = &xfrm->id.daddr; 2742 } 2743 return daddr; 2744 } 2745 2746 static struct neighbour *xfrm_neigh_lookup(const struct dst_entry *dst, 2747 struct sk_buff *skb, 2748 const void *daddr) 2749 { 2750 const struct dst_entry *path = xfrm_dst_path(dst); 2751 2752 if (!skb) 2753 daddr = xfrm_get_dst_nexthop(dst, daddr); 2754 return path->ops->neigh_lookup(path, skb, daddr); 2755 } 2756 2757 static void xfrm_confirm_neigh(const struct dst_entry *dst, const void *daddr) 2758 { 2759 const struct dst_entry *path = xfrm_dst_path(dst); 2760 2761 daddr = xfrm_get_dst_nexthop(dst, daddr); 2762 path->ops->confirm_neigh(path, daddr); 2763 } 2764 2765 int xfrm_policy_register_afinfo(const struct xfrm_policy_afinfo *afinfo, int family) 2766 { 2767 int err = 0; 2768 2769 if (WARN_ON(family >= ARRAY_SIZE(xfrm_policy_afinfo))) 2770 return -EAFNOSUPPORT; 2771 2772 spin_lock(&xfrm_policy_afinfo_lock); 2773 if (unlikely(xfrm_policy_afinfo[family] != NULL)) 2774 err = -EEXIST; 2775 else { 2776 struct dst_ops *dst_ops = afinfo->dst_ops; 2777 if (likely(dst_ops->kmem_cachep == NULL)) 2778 dst_ops->kmem_cachep = xfrm_dst_cache; 2779 if (likely(dst_ops->check == NULL)) 2780 dst_ops->check = xfrm_dst_check; 2781 if (likely(dst_ops->default_advmss == NULL)) 2782 dst_ops->default_advmss = xfrm_default_advmss; 2783 if (likely(dst_ops->mtu == NULL)) 2784 dst_ops->mtu = xfrm_mtu; 2785 if (likely(dst_ops->negative_advice == NULL)) 2786 dst_ops->negative_advice = xfrm_negative_advice; 2787 if (likely(dst_ops->link_failure == NULL)) 2788 dst_ops->link_failure = xfrm_link_failure; 2789 if (likely(dst_ops->neigh_lookup == NULL)) 2790 dst_ops->neigh_lookup = xfrm_neigh_lookup; 2791 if (likely(!dst_ops->confirm_neigh)) 2792 dst_ops->confirm_neigh = xfrm_confirm_neigh; 2793 rcu_assign_pointer(xfrm_policy_afinfo[family], afinfo); 2794 } 2795 spin_unlock(&xfrm_policy_afinfo_lock); 2796 2797 return err; 2798 } 2799 EXPORT_SYMBOL(xfrm_policy_register_afinfo); 2800 2801 void xfrm_policy_unregister_afinfo(const struct xfrm_policy_afinfo *afinfo) 2802 { 2803 struct dst_ops *dst_ops = afinfo->dst_ops; 2804 int i; 2805 2806 for (i = 0; i < ARRAY_SIZE(xfrm_policy_afinfo); i++) { 2807 if (xfrm_policy_afinfo[i] != afinfo) 2808 continue; 2809 RCU_INIT_POINTER(xfrm_policy_afinfo[i], NULL); 2810 break; 2811 } 2812 2813 synchronize_rcu(); 2814 2815 dst_ops->kmem_cachep = NULL; 2816 dst_ops->check = NULL; 2817 dst_ops->negative_advice = NULL; 2818 dst_ops->link_failure = NULL; 2819 } 2820 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo); 2821 2822 #ifdef CONFIG_XFRM_STATISTICS 2823 static int __net_init xfrm_statistics_init(struct net *net) 2824 { 2825 int rv; 2826 net->mib.xfrm_statistics = alloc_percpu(struct linux_xfrm_mib); 2827 if (!net->mib.xfrm_statistics) 2828 return -ENOMEM; 2829 rv = xfrm_proc_init(net); 2830 if (rv < 0) 2831 free_percpu(net->mib.xfrm_statistics); 2832 return rv; 2833 } 2834 2835 static void xfrm_statistics_fini(struct net *net) 2836 { 2837 xfrm_proc_fini(net); 2838 free_percpu(net->mib.xfrm_statistics); 2839 } 2840 #else 2841 static int __net_init xfrm_statistics_init(struct net *net) 2842 { 2843 return 0; 2844 } 2845 2846 static void xfrm_statistics_fini(struct net *net) 2847 { 2848 } 2849 #endif 2850 2851 static int __net_init xfrm_policy_init(struct net *net) 2852 { 2853 unsigned int hmask, sz; 2854 int dir; 2855 2856 if (net_eq(net, &init_net)) 2857 xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache", 2858 sizeof(struct xfrm_dst), 2859 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, 2860 NULL); 2861 2862 hmask = 8 - 1; 2863 sz = (hmask+1) * sizeof(struct hlist_head); 2864 2865 net->xfrm.policy_byidx = xfrm_hash_alloc(sz); 2866 if (!net->xfrm.policy_byidx) 2867 goto out_byidx; 2868 net->xfrm.policy_idx_hmask = hmask; 2869 2870 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) { 2871 struct xfrm_policy_hash *htab; 2872 2873 net->xfrm.policy_count[dir] = 0; 2874 net->xfrm.policy_count[XFRM_POLICY_MAX + dir] = 0; 2875 INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]); 2876 2877 htab = &net->xfrm.policy_bydst[dir]; 2878 htab->table = xfrm_hash_alloc(sz); 2879 if (!htab->table) 2880 goto out_bydst; 2881 htab->hmask = hmask; 2882 htab->dbits4 = 32; 2883 htab->sbits4 = 32; 2884 htab->dbits6 = 128; 2885 htab->sbits6 = 128; 2886 } 2887 net->xfrm.policy_hthresh.lbits4 = 32; 2888 net->xfrm.policy_hthresh.rbits4 = 32; 2889 net->xfrm.policy_hthresh.lbits6 = 128; 2890 net->xfrm.policy_hthresh.rbits6 = 128; 2891 2892 seqlock_init(&net->xfrm.policy_hthresh.lock); 2893 2894 INIT_LIST_HEAD(&net->xfrm.policy_all); 2895 INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize); 2896 INIT_WORK(&net->xfrm.policy_hthresh.work, xfrm_hash_rebuild); 2897 return 0; 2898 2899 out_bydst: 2900 for (dir--; dir >= 0; dir--) { 2901 struct xfrm_policy_hash *htab; 2902 2903 htab = &net->xfrm.policy_bydst[dir]; 2904 xfrm_hash_free(htab->table, sz); 2905 } 2906 xfrm_hash_free(net->xfrm.policy_byidx, sz); 2907 out_byidx: 2908 return -ENOMEM; 2909 } 2910 2911 static void xfrm_policy_fini(struct net *net) 2912 { 2913 unsigned int sz; 2914 int dir; 2915 2916 flush_work(&net->xfrm.policy_hash_work); 2917 #ifdef CONFIG_XFRM_SUB_POLICY 2918 xfrm_policy_flush(net, XFRM_POLICY_TYPE_SUB, false); 2919 #endif 2920 xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, false); 2921 2922 WARN_ON(!list_empty(&net->xfrm.policy_all)); 2923 2924 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) { 2925 struct xfrm_policy_hash *htab; 2926 2927 WARN_ON(!hlist_empty(&net->xfrm.policy_inexact[dir])); 2928 2929 htab = &net->xfrm.policy_bydst[dir]; 2930 sz = (htab->hmask + 1) * sizeof(struct hlist_head); 2931 WARN_ON(!hlist_empty(htab->table)); 2932 xfrm_hash_free(htab->table, sz); 2933 } 2934 2935 sz = (net->xfrm.policy_idx_hmask + 1) * sizeof(struct hlist_head); 2936 WARN_ON(!hlist_empty(net->xfrm.policy_byidx)); 2937 xfrm_hash_free(net->xfrm.policy_byidx, sz); 2938 } 2939 2940 static int __net_init xfrm_net_init(struct net *net) 2941 { 2942 int rv; 2943 2944 /* Initialize the per-net locks here */ 2945 spin_lock_init(&net->xfrm.xfrm_state_lock); 2946 spin_lock_init(&net->xfrm.xfrm_policy_lock); 2947 mutex_init(&net->xfrm.xfrm_cfg_mutex); 2948 2949 rv = xfrm_statistics_init(net); 2950 if (rv < 0) 2951 goto out_statistics; 2952 rv = xfrm_state_init(net); 2953 if (rv < 0) 2954 goto out_state; 2955 rv = xfrm_policy_init(net); 2956 if (rv < 0) 2957 goto out_policy; 2958 rv = xfrm_sysctl_init(net); 2959 if (rv < 0) 2960 goto out_sysctl; 2961 2962 return 0; 2963 2964 out_sysctl: 2965 xfrm_policy_fini(net); 2966 out_policy: 2967 xfrm_state_fini(net); 2968 out_state: 2969 xfrm_statistics_fini(net); 2970 out_statistics: 2971 return rv; 2972 } 2973 2974 static void __net_exit xfrm_net_exit(struct net *net) 2975 { 2976 xfrm_sysctl_fini(net); 2977 xfrm_policy_fini(net); 2978 xfrm_state_fini(net); 2979 xfrm_statistics_fini(net); 2980 } 2981 2982 static struct pernet_operations __net_initdata xfrm_net_ops = { 2983 .init = xfrm_net_init, 2984 .exit = xfrm_net_exit, 2985 }; 2986 2987 void __init xfrm_init(void) 2988 { 2989 int i; 2990 2991 xfrm_pcpu_work = kmalloc_array(NR_CPUS, sizeof(*xfrm_pcpu_work), 2992 GFP_KERNEL); 2993 BUG_ON(!xfrm_pcpu_work); 2994 2995 for (i = 0; i < NR_CPUS; i++) 2996 INIT_WORK(&xfrm_pcpu_work[i], xfrm_pcpu_work_fn); 2997 2998 register_pernet_subsys(&xfrm_net_ops); 2999 xfrm_dev_init(); 3000 seqcount_init(&xfrm_policy_hash_generation); 3001 xfrm_input_init(); 3002 } 3003 3004 #ifdef CONFIG_AUDITSYSCALL 3005 static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp, 3006 struct audit_buffer *audit_buf) 3007 { 3008 struct xfrm_sec_ctx *ctx = xp->security; 3009 struct xfrm_selector *sel = &xp->selector; 3010 3011 if (ctx) 3012 audit_log_format(audit_buf, " sec_alg=%u sec_doi=%u sec_obj=%s", 3013 ctx->ctx_alg, ctx->ctx_doi, ctx->ctx_str); 3014 3015 switch (sel->family) { 3016 case AF_INET: 3017 audit_log_format(audit_buf, " src=%pI4", &sel->saddr.a4); 3018 if (sel->prefixlen_s != 32) 3019 audit_log_format(audit_buf, " src_prefixlen=%d", 3020 sel->prefixlen_s); 3021 audit_log_format(audit_buf, " dst=%pI4", &sel->daddr.a4); 3022 if (sel->prefixlen_d != 32) 3023 audit_log_format(audit_buf, " dst_prefixlen=%d", 3024 sel->prefixlen_d); 3025 break; 3026 case AF_INET6: 3027 audit_log_format(audit_buf, " src=%pI6", sel->saddr.a6); 3028 if (sel->prefixlen_s != 128) 3029 audit_log_format(audit_buf, " src_prefixlen=%d", 3030 sel->prefixlen_s); 3031 audit_log_format(audit_buf, " dst=%pI6", sel->daddr.a6); 3032 if (sel->prefixlen_d != 128) 3033 audit_log_format(audit_buf, " dst_prefixlen=%d", 3034 sel->prefixlen_d); 3035 break; 3036 } 3037 } 3038 3039 void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid) 3040 { 3041 struct audit_buffer *audit_buf; 3042 3043 audit_buf = xfrm_audit_start("SPD-add"); 3044 if (audit_buf == NULL) 3045 return; 3046 xfrm_audit_helper_usrinfo(task_valid, audit_buf); 3047 audit_log_format(audit_buf, " res=%u", result); 3048 xfrm_audit_common_policyinfo(xp, audit_buf); 3049 audit_log_end(audit_buf); 3050 } 3051 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add); 3052 3053 void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result, 3054 bool task_valid) 3055 { 3056 struct audit_buffer *audit_buf; 3057 3058 audit_buf = xfrm_audit_start("SPD-delete"); 3059 if (audit_buf == NULL) 3060 return; 3061 xfrm_audit_helper_usrinfo(task_valid, audit_buf); 3062 audit_log_format(audit_buf, " res=%u", result); 3063 xfrm_audit_common_policyinfo(xp, audit_buf); 3064 audit_log_end(audit_buf); 3065 } 3066 EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete); 3067 #endif 3068 3069 #ifdef CONFIG_XFRM_MIGRATE 3070 static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp, 3071 const struct xfrm_selector *sel_tgt) 3072 { 3073 if (sel_cmp->proto == IPSEC_ULPROTO_ANY) { 3074 if (sel_tgt->family == sel_cmp->family && 3075 xfrm_addr_equal(&sel_tgt->daddr, &sel_cmp->daddr, 3076 sel_cmp->family) && 3077 xfrm_addr_equal(&sel_tgt->saddr, &sel_cmp->saddr, 3078 sel_cmp->family) && 3079 sel_tgt->prefixlen_d == sel_cmp->prefixlen_d && 3080 sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) { 3081 return true; 3082 } 3083 } else { 3084 if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) { 3085 return true; 3086 } 3087 } 3088 return false; 3089 } 3090 3091 static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector *sel, 3092 u8 dir, u8 type, struct net *net) 3093 { 3094 struct xfrm_policy *pol, *ret = NULL; 3095 struct hlist_head *chain; 3096 u32 priority = ~0U; 3097 3098 spin_lock_bh(&net->xfrm.xfrm_policy_lock); 3099 chain = policy_hash_direct(net, &sel->daddr, &sel->saddr, sel->family, dir); 3100 hlist_for_each_entry(pol, chain, bydst) { 3101 if (xfrm_migrate_selector_match(sel, &pol->selector) && 3102 pol->type == type) { 3103 ret = pol; 3104 priority = ret->priority; 3105 break; 3106 } 3107 } 3108 chain = &net->xfrm.policy_inexact[dir]; 3109 hlist_for_each_entry(pol, chain, bydst) { 3110 if ((pol->priority >= priority) && ret) 3111 break; 3112 3113 if (xfrm_migrate_selector_match(sel, &pol->selector) && 3114 pol->type == type) { 3115 ret = pol; 3116 break; 3117 } 3118 } 3119 3120 xfrm_pol_hold(ret); 3121 3122 spin_unlock_bh(&net->xfrm.xfrm_policy_lock); 3123 3124 return ret; 3125 } 3126 3127 static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t) 3128 { 3129 int match = 0; 3130 3131 if (t->mode == m->mode && t->id.proto == m->proto && 3132 (m->reqid == 0 || t->reqid == m->reqid)) { 3133 switch (t->mode) { 3134 case XFRM_MODE_TUNNEL: 3135 case XFRM_MODE_BEET: 3136 if (xfrm_addr_equal(&t->id.daddr, &m->old_daddr, 3137 m->old_family) && 3138 xfrm_addr_equal(&t->saddr, &m->old_saddr, 3139 m->old_family)) { 3140 match = 1; 3141 } 3142 break; 3143 case XFRM_MODE_TRANSPORT: 3144 /* in case of transport mode, template does not store 3145 any IP addresses, hence we just compare mode and 3146 protocol */ 3147 match = 1; 3148 break; 3149 default: 3150 break; 3151 } 3152 } 3153 return match; 3154 } 3155 3156 /* update endpoint address(es) of template(s) */ 3157 static int xfrm_policy_migrate(struct xfrm_policy *pol, 3158 struct xfrm_migrate *m, int num_migrate) 3159 { 3160 struct xfrm_migrate *mp; 3161 int i, j, n = 0; 3162 3163 write_lock_bh(&pol->lock); 3164 if (unlikely(pol->walk.dead)) { 3165 /* target policy has been deleted */ 3166 write_unlock_bh(&pol->lock); 3167 return -ENOENT; 3168 } 3169 3170 for (i = 0; i < pol->xfrm_nr; i++) { 3171 for (j = 0, mp = m; j < num_migrate; j++, mp++) { 3172 if (!migrate_tmpl_match(mp, &pol->xfrm_vec[i])) 3173 continue; 3174 n++; 3175 if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL && 3176 pol->xfrm_vec[i].mode != XFRM_MODE_BEET) 3177 continue; 3178 /* update endpoints */ 3179 memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr, 3180 sizeof(pol->xfrm_vec[i].id.daddr)); 3181 memcpy(&pol->xfrm_vec[i].saddr, &mp->new_saddr, 3182 sizeof(pol->xfrm_vec[i].saddr)); 3183 pol->xfrm_vec[i].encap_family = mp->new_family; 3184 /* flush bundles */ 3185 atomic_inc(&pol->genid); 3186 } 3187 } 3188 3189 write_unlock_bh(&pol->lock); 3190 3191 if (!n) 3192 return -ENODATA; 3193 3194 return 0; 3195 } 3196 3197 static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate) 3198 { 3199 int i, j; 3200 3201 if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH) 3202 return -EINVAL; 3203 3204 for (i = 0; i < num_migrate; i++) { 3205 if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) || 3206 xfrm_addr_any(&m[i].new_saddr, m[i].new_family)) 3207 return -EINVAL; 3208 3209 /* check if there is any duplicated entry */ 3210 for (j = i + 1; j < num_migrate; j++) { 3211 if (!memcmp(&m[i].old_daddr, &m[j].old_daddr, 3212 sizeof(m[i].old_daddr)) && 3213 !memcmp(&m[i].old_saddr, &m[j].old_saddr, 3214 sizeof(m[i].old_saddr)) && 3215 m[i].proto == m[j].proto && 3216 m[i].mode == m[j].mode && 3217 m[i].reqid == m[j].reqid && 3218 m[i].old_family == m[j].old_family) 3219 return -EINVAL; 3220 } 3221 } 3222 3223 return 0; 3224 } 3225 3226 int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type, 3227 struct xfrm_migrate *m, int num_migrate, 3228 struct xfrm_kmaddress *k, struct net *net, 3229 struct xfrm_encap_tmpl *encap) 3230 { 3231 int i, err, nx_cur = 0, nx_new = 0; 3232 struct xfrm_policy *pol = NULL; 3233 struct xfrm_state *x, *xc; 3234 struct xfrm_state *x_cur[XFRM_MAX_DEPTH]; 3235 struct xfrm_state *x_new[XFRM_MAX_DEPTH]; 3236 struct xfrm_migrate *mp; 3237 3238 /* Stage 0 - sanity checks */ 3239 if ((err = xfrm_migrate_check(m, num_migrate)) < 0) 3240 goto out; 3241 3242 if (dir >= XFRM_POLICY_MAX) { 3243 err = -EINVAL; 3244 goto out; 3245 } 3246 3247 /* Stage 1 - find policy */ 3248 if ((pol = xfrm_migrate_policy_find(sel, dir, type, net)) == NULL) { 3249 err = -ENOENT; 3250 goto out; 3251 } 3252 3253 /* Stage 2 - find and update state(s) */ 3254 for (i = 0, mp = m; i < num_migrate; i++, mp++) { 3255 if ((x = xfrm_migrate_state_find(mp, net))) { 3256 x_cur[nx_cur] = x; 3257 nx_cur++; 3258 xc = xfrm_state_migrate(x, mp, encap); 3259 if (xc) { 3260 x_new[nx_new] = xc; 3261 nx_new++; 3262 } else { 3263 err = -ENODATA; 3264 goto restore_state; 3265 } 3266 } 3267 } 3268 3269 /* Stage 3 - update policy */ 3270 if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0) 3271 goto restore_state; 3272 3273 /* Stage 4 - delete old state(s) */ 3274 if (nx_cur) { 3275 xfrm_states_put(x_cur, nx_cur); 3276 xfrm_states_delete(x_cur, nx_cur); 3277 } 3278 3279 /* Stage 5 - announce */ 3280 km_migrate(sel, dir, type, m, num_migrate, k, encap); 3281 3282 xfrm_pol_put(pol); 3283 3284 return 0; 3285 out: 3286 return err; 3287 3288 restore_state: 3289 if (pol) 3290 xfrm_pol_put(pol); 3291 if (nx_cur) 3292 xfrm_states_put(x_cur, nx_cur); 3293 if (nx_new) 3294 xfrm_states_delete(x_new, nx_new); 3295 3296 return err; 3297 } 3298 EXPORT_SYMBOL(xfrm_migrate); 3299 #endif 3300