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/config.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 <net/xfrm.h> 27 #include <net/ip.h> 28 29 DEFINE_MUTEX(xfrm_cfg_mutex); 30 EXPORT_SYMBOL(xfrm_cfg_mutex); 31 32 static DEFINE_RWLOCK(xfrm_policy_lock); 33 34 struct xfrm_policy *xfrm_policy_list[XFRM_POLICY_MAX*2]; 35 EXPORT_SYMBOL(xfrm_policy_list); 36 37 static DEFINE_RWLOCK(xfrm_policy_afinfo_lock); 38 static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO]; 39 40 static kmem_cache_t *xfrm_dst_cache __read_mostly; 41 42 static struct work_struct xfrm_policy_gc_work; 43 static struct list_head xfrm_policy_gc_list = 44 LIST_HEAD_INIT(xfrm_policy_gc_list); 45 static DEFINE_SPINLOCK(xfrm_policy_gc_lock); 46 47 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family); 48 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo); 49 50 int xfrm_register_type(struct xfrm_type *type, unsigned short family) 51 { 52 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); 53 struct xfrm_type_map *typemap; 54 int err = 0; 55 56 if (unlikely(afinfo == NULL)) 57 return -EAFNOSUPPORT; 58 typemap = afinfo->type_map; 59 60 write_lock(&typemap->lock); 61 if (likely(typemap->map[type->proto] == NULL)) 62 typemap->map[type->proto] = type; 63 else 64 err = -EEXIST; 65 write_unlock(&typemap->lock); 66 xfrm_policy_put_afinfo(afinfo); 67 return err; 68 } 69 EXPORT_SYMBOL(xfrm_register_type); 70 71 int xfrm_unregister_type(struct xfrm_type *type, unsigned short family) 72 { 73 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); 74 struct xfrm_type_map *typemap; 75 int err = 0; 76 77 if (unlikely(afinfo == NULL)) 78 return -EAFNOSUPPORT; 79 typemap = afinfo->type_map; 80 81 write_lock(&typemap->lock); 82 if (unlikely(typemap->map[type->proto] != type)) 83 err = -ENOENT; 84 else 85 typemap->map[type->proto] = NULL; 86 write_unlock(&typemap->lock); 87 xfrm_policy_put_afinfo(afinfo); 88 return err; 89 } 90 EXPORT_SYMBOL(xfrm_unregister_type); 91 92 struct xfrm_type *xfrm_get_type(u8 proto, unsigned short family) 93 { 94 struct xfrm_policy_afinfo *afinfo; 95 struct xfrm_type_map *typemap; 96 struct xfrm_type *type; 97 int modload_attempted = 0; 98 99 retry: 100 afinfo = xfrm_policy_get_afinfo(family); 101 if (unlikely(afinfo == NULL)) 102 return NULL; 103 typemap = afinfo->type_map; 104 105 read_lock(&typemap->lock); 106 type = typemap->map[proto]; 107 if (unlikely(type && !try_module_get(type->owner))) 108 type = NULL; 109 read_unlock(&typemap->lock); 110 if (!type && !modload_attempted) { 111 xfrm_policy_put_afinfo(afinfo); 112 request_module("xfrm-type-%d-%d", 113 (int) family, (int) proto); 114 modload_attempted = 1; 115 goto retry; 116 } 117 118 xfrm_policy_put_afinfo(afinfo); 119 return type; 120 } 121 122 int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl, 123 unsigned short family) 124 { 125 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); 126 int err = 0; 127 128 if (unlikely(afinfo == NULL)) 129 return -EAFNOSUPPORT; 130 131 if (likely(afinfo->dst_lookup != NULL)) 132 err = afinfo->dst_lookup(dst, fl); 133 else 134 err = -EINVAL; 135 xfrm_policy_put_afinfo(afinfo); 136 return err; 137 } 138 EXPORT_SYMBOL(xfrm_dst_lookup); 139 140 void xfrm_put_type(struct xfrm_type *type) 141 { 142 module_put(type->owner); 143 } 144 145 static inline unsigned long make_jiffies(long secs) 146 { 147 if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ) 148 return MAX_SCHEDULE_TIMEOUT-1; 149 else 150 return secs*HZ; 151 } 152 153 static void xfrm_policy_timer(unsigned long data) 154 { 155 struct xfrm_policy *xp = (struct xfrm_policy*)data; 156 unsigned long now = (unsigned long)xtime.tv_sec; 157 long next = LONG_MAX; 158 int warn = 0; 159 int dir; 160 161 read_lock(&xp->lock); 162 163 if (xp->dead) 164 goto out; 165 166 dir = xfrm_policy_id2dir(xp->index); 167 168 if (xp->lft.hard_add_expires_seconds) { 169 long tmo = xp->lft.hard_add_expires_seconds + 170 xp->curlft.add_time - now; 171 if (tmo <= 0) 172 goto expired; 173 if (tmo < next) 174 next = tmo; 175 } 176 if (xp->lft.hard_use_expires_seconds) { 177 long tmo = xp->lft.hard_use_expires_seconds + 178 (xp->curlft.use_time ? : xp->curlft.add_time) - now; 179 if (tmo <= 0) 180 goto expired; 181 if (tmo < next) 182 next = tmo; 183 } 184 if (xp->lft.soft_add_expires_seconds) { 185 long tmo = xp->lft.soft_add_expires_seconds + 186 xp->curlft.add_time - now; 187 if (tmo <= 0) { 188 warn = 1; 189 tmo = XFRM_KM_TIMEOUT; 190 } 191 if (tmo < next) 192 next = tmo; 193 } 194 if (xp->lft.soft_use_expires_seconds) { 195 long tmo = xp->lft.soft_use_expires_seconds + 196 (xp->curlft.use_time ? : xp->curlft.add_time) - now; 197 if (tmo <= 0) { 198 warn = 1; 199 tmo = XFRM_KM_TIMEOUT; 200 } 201 if (tmo < next) 202 next = tmo; 203 } 204 205 if (warn) 206 km_policy_expired(xp, dir, 0, 0); 207 if (next != LONG_MAX && 208 !mod_timer(&xp->timer, jiffies + make_jiffies(next))) 209 xfrm_pol_hold(xp); 210 211 out: 212 read_unlock(&xp->lock); 213 xfrm_pol_put(xp); 214 return; 215 216 expired: 217 read_unlock(&xp->lock); 218 if (!xfrm_policy_delete(xp, dir)) 219 km_policy_expired(xp, dir, 1, 0); 220 xfrm_pol_put(xp); 221 } 222 223 224 /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2 225 * SPD calls. 226 */ 227 228 struct xfrm_policy *xfrm_policy_alloc(gfp_t gfp) 229 { 230 struct xfrm_policy *policy; 231 232 policy = kmalloc(sizeof(struct xfrm_policy), gfp); 233 234 if (policy) { 235 memset(policy, 0, sizeof(struct xfrm_policy)); 236 atomic_set(&policy->refcnt, 1); 237 rwlock_init(&policy->lock); 238 init_timer(&policy->timer); 239 policy->timer.data = (unsigned long)policy; 240 policy->timer.function = xfrm_policy_timer; 241 } 242 return policy; 243 } 244 EXPORT_SYMBOL(xfrm_policy_alloc); 245 246 /* Destroy xfrm_policy: descendant resources must be released to this moment. */ 247 248 void __xfrm_policy_destroy(struct xfrm_policy *policy) 249 { 250 BUG_ON(!policy->dead); 251 252 BUG_ON(policy->bundles); 253 254 if (del_timer(&policy->timer)) 255 BUG(); 256 257 security_xfrm_policy_free(policy); 258 kfree(policy); 259 } 260 EXPORT_SYMBOL(__xfrm_policy_destroy); 261 262 static void xfrm_policy_gc_kill(struct xfrm_policy *policy) 263 { 264 struct dst_entry *dst; 265 266 while ((dst = policy->bundles) != NULL) { 267 policy->bundles = dst->next; 268 dst_free(dst); 269 } 270 271 if (del_timer(&policy->timer)) 272 atomic_dec(&policy->refcnt); 273 274 if (atomic_read(&policy->refcnt) > 1) 275 flow_cache_flush(); 276 277 xfrm_pol_put(policy); 278 } 279 280 static void xfrm_policy_gc_task(void *data) 281 { 282 struct xfrm_policy *policy; 283 struct list_head *entry, *tmp; 284 struct list_head gc_list = LIST_HEAD_INIT(gc_list); 285 286 spin_lock_bh(&xfrm_policy_gc_lock); 287 list_splice_init(&xfrm_policy_gc_list, &gc_list); 288 spin_unlock_bh(&xfrm_policy_gc_lock); 289 290 list_for_each_safe(entry, tmp, &gc_list) { 291 policy = list_entry(entry, struct xfrm_policy, list); 292 xfrm_policy_gc_kill(policy); 293 } 294 } 295 296 /* Rule must be locked. Release descentant resources, announce 297 * entry dead. The rule must be unlinked from lists to the moment. 298 */ 299 300 static void xfrm_policy_kill(struct xfrm_policy *policy) 301 { 302 int dead; 303 304 write_lock_bh(&policy->lock); 305 dead = policy->dead; 306 policy->dead = 1; 307 write_unlock_bh(&policy->lock); 308 309 if (unlikely(dead)) { 310 WARN_ON(1); 311 return; 312 } 313 314 spin_lock(&xfrm_policy_gc_lock); 315 list_add(&policy->list, &xfrm_policy_gc_list); 316 spin_unlock(&xfrm_policy_gc_lock); 317 318 schedule_work(&xfrm_policy_gc_work); 319 } 320 321 /* Generate new index... KAME seems to generate them ordered by cost 322 * of an absolute inpredictability of ordering of rules. This will not pass. */ 323 static u32 xfrm_gen_index(int dir) 324 { 325 u32 idx; 326 struct xfrm_policy *p; 327 static u32 idx_generator; 328 329 for (;;) { 330 idx = (idx_generator | dir); 331 idx_generator += 8; 332 if (idx == 0) 333 idx = 8; 334 for (p = xfrm_policy_list[dir]; p; p = p->next) { 335 if (p->index == idx) 336 break; 337 } 338 if (!p) 339 return idx; 340 } 341 } 342 343 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl) 344 { 345 struct xfrm_policy *pol, **p; 346 struct xfrm_policy *delpol = NULL; 347 struct xfrm_policy **newpos = NULL; 348 struct dst_entry *gc_list; 349 350 write_lock_bh(&xfrm_policy_lock); 351 for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL;) { 352 if (!delpol && memcmp(&policy->selector, &pol->selector, sizeof(pol->selector)) == 0 && 353 xfrm_sec_ctx_match(pol->security, policy->security)) { 354 if (excl) { 355 write_unlock_bh(&xfrm_policy_lock); 356 return -EEXIST; 357 } 358 *p = pol->next; 359 delpol = pol; 360 if (policy->priority > pol->priority) 361 continue; 362 } else if (policy->priority >= pol->priority) { 363 p = &pol->next; 364 continue; 365 } 366 if (!newpos) 367 newpos = p; 368 if (delpol) 369 break; 370 p = &pol->next; 371 } 372 if (newpos) 373 p = newpos; 374 xfrm_pol_hold(policy); 375 policy->next = *p; 376 *p = policy; 377 atomic_inc(&flow_cache_genid); 378 policy->index = delpol ? delpol->index : xfrm_gen_index(dir); 379 policy->curlft.add_time = (unsigned long)xtime.tv_sec; 380 policy->curlft.use_time = 0; 381 if (!mod_timer(&policy->timer, jiffies + HZ)) 382 xfrm_pol_hold(policy); 383 write_unlock_bh(&xfrm_policy_lock); 384 385 if (delpol) 386 xfrm_policy_kill(delpol); 387 388 read_lock_bh(&xfrm_policy_lock); 389 gc_list = NULL; 390 for (policy = policy->next; policy; policy = policy->next) { 391 struct dst_entry *dst; 392 393 write_lock(&policy->lock); 394 dst = policy->bundles; 395 if (dst) { 396 struct dst_entry *tail = dst; 397 while (tail->next) 398 tail = tail->next; 399 tail->next = gc_list; 400 gc_list = dst; 401 402 policy->bundles = NULL; 403 } 404 write_unlock(&policy->lock); 405 } 406 read_unlock_bh(&xfrm_policy_lock); 407 408 while (gc_list) { 409 struct dst_entry *dst = gc_list; 410 411 gc_list = dst->next; 412 dst_free(dst); 413 } 414 415 return 0; 416 } 417 EXPORT_SYMBOL(xfrm_policy_insert); 418 419 struct xfrm_policy *xfrm_policy_bysel_ctx(int dir, struct xfrm_selector *sel, 420 struct xfrm_sec_ctx *ctx, int delete) 421 { 422 struct xfrm_policy *pol, **p; 423 424 write_lock_bh(&xfrm_policy_lock); 425 for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL; p = &pol->next) { 426 if ((memcmp(sel, &pol->selector, sizeof(*sel)) == 0) && 427 (xfrm_sec_ctx_match(ctx, pol->security))) { 428 xfrm_pol_hold(pol); 429 if (delete) 430 *p = pol->next; 431 break; 432 } 433 } 434 write_unlock_bh(&xfrm_policy_lock); 435 436 if (pol && delete) { 437 atomic_inc(&flow_cache_genid); 438 xfrm_policy_kill(pol); 439 } 440 return pol; 441 } 442 EXPORT_SYMBOL(xfrm_policy_bysel_ctx); 443 444 struct xfrm_policy *xfrm_policy_byid(int dir, u32 id, int delete) 445 { 446 struct xfrm_policy *pol, **p; 447 448 write_lock_bh(&xfrm_policy_lock); 449 for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL; p = &pol->next) { 450 if (pol->index == id) { 451 xfrm_pol_hold(pol); 452 if (delete) 453 *p = pol->next; 454 break; 455 } 456 } 457 write_unlock_bh(&xfrm_policy_lock); 458 459 if (pol && delete) { 460 atomic_inc(&flow_cache_genid); 461 xfrm_policy_kill(pol); 462 } 463 return pol; 464 } 465 EXPORT_SYMBOL(xfrm_policy_byid); 466 467 void xfrm_policy_flush(void) 468 { 469 struct xfrm_policy *xp; 470 int dir; 471 472 write_lock_bh(&xfrm_policy_lock); 473 for (dir = 0; dir < XFRM_POLICY_MAX; dir++) { 474 while ((xp = xfrm_policy_list[dir]) != NULL) { 475 xfrm_policy_list[dir] = xp->next; 476 write_unlock_bh(&xfrm_policy_lock); 477 478 xfrm_policy_kill(xp); 479 480 write_lock_bh(&xfrm_policy_lock); 481 } 482 } 483 atomic_inc(&flow_cache_genid); 484 write_unlock_bh(&xfrm_policy_lock); 485 } 486 EXPORT_SYMBOL(xfrm_policy_flush); 487 488 int xfrm_policy_walk(int (*func)(struct xfrm_policy *, int, int, void*), 489 void *data) 490 { 491 struct xfrm_policy *xp; 492 int dir; 493 int count = 0; 494 int error = 0; 495 496 read_lock_bh(&xfrm_policy_lock); 497 for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) { 498 for (xp = xfrm_policy_list[dir]; xp; xp = xp->next) 499 count++; 500 } 501 502 if (count == 0) { 503 error = -ENOENT; 504 goto out; 505 } 506 507 for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) { 508 for (xp = xfrm_policy_list[dir]; xp; xp = xp->next) { 509 error = func(xp, dir%XFRM_POLICY_MAX, --count, data); 510 if (error) 511 goto out; 512 } 513 } 514 515 out: 516 read_unlock_bh(&xfrm_policy_lock); 517 return error; 518 } 519 EXPORT_SYMBOL(xfrm_policy_walk); 520 521 /* Find policy to apply to this flow. */ 522 523 static void xfrm_policy_lookup(struct flowi *fl, u32 sk_sid, u16 family, u8 dir, 524 void **objp, atomic_t **obj_refp) 525 { 526 struct xfrm_policy *pol; 527 528 read_lock_bh(&xfrm_policy_lock); 529 for (pol = xfrm_policy_list[dir]; pol; pol = pol->next) { 530 struct xfrm_selector *sel = &pol->selector; 531 int match; 532 533 if (pol->family != family) 534 continue; 535 536 match = xfrm_selector_match(sel, fl, family); 537 538 if (match) { 539 if (!security_xfrm_policy_lookup(pol, sk_sid, dir)) { 540 xfrm_pol_hold(pol); 541 break; 542 } 543 } 544 } 545 read_unlock_bh(&xfrm_policy_lock); 546 if ((*objp = (void *) pol) != NULL) 547 *obj_refp = &pol->refcnt; 548 } 549 550 static inline int policy_to_flow_dir(int dir) 551 { 552 if (XFRM_POLICY_IN == FLOW_DIR_IN && 553 XFRM_POLICY_OUT == FLOW_DIR_OUT && 554 XFRM_POLICY_FWD == FLOW_DIR_FWD) 555 return dir; 556 switch (dir) { 557 default: 558 case XFRM_POLICY_IN: 559 return FLOW_DIR_IN; 560 case XFRM_POLICY_OUT: 561 return FLOW_DIR_OUT; 562 case XFRM_POLICY_FWD: 563 return FLOW_DIR_FWD; 564 }; 565 } 566 567 static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl, u32 sk_sid) 568 { 569 struct xfrm_policy *pol; 570 571 read_lock_bh(&xfrm_policy_lock); 572 if ((pol = sk->sk_policy[dir]) != NULL) { 573 int match = xfrm_selector_match(&pol->selector, fl, 574 sk->sk_family); 575 int err = 0; 576 577 if (match) 578 err = security_xfrm_policy_lookup(pol, sk_sid, policy_to_flow_dir(dir)); 579 580 if (match && !err) 581 xfrm_pol_hold(pol); 582 else 583 pol = NULL; 584 } 585 read_unlock_bh(&xfrm_policy_lock); 586 return pol; 587 } 588 589 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir) 590 { 591 pol->next = xfrm_policy_list[dir]; 592 xfrm_policy_list[dir] = pol; 593 xfrm_pol_hold(pol); 594 } 595 596 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol, 597 int dir) 598 { 599 struct xfrm_policy **polp; 600 601 for (polp = &xfrm_policy_list[dir]; 602 *polp != NULL; polp = &(*polp)->next) { 603 if (*polp == pol) { 604 *polp = pol->next; 605 return pol; 606 } 607 } 608 return NULL; 609 } 610 611 int xfrm_policy_delete(struct xfrm_policy *pol, int dir) 612 { 613 write_lock_bh(&xfrm_policy_lock); 614 pol = __xfrm_policy_unlink(pol, dir); 615 write_unlock_bh(&xfrm_policy_lock); 616 if (pol) { 617 if (dir < XFRM_POLICY_MAX) 618 atomic_inc(&flow_cache_genid); 619 xfrm_policy_kill(pol); 620 return 0; 621 } 622 return -ENOENT; 623 } 624 EXPORT_SYMBOL(xfrm_policy_delete); 625 626 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol) 627 { 628 struct xfrm_policy *old_pol; 629 630 write_lock_bh(&xfrm_policy_lock); 631 old_pol = sk->sk_policy[dir]; 632 sk->sk_policy[dir] = pol; 633 if (pol) { 634 pol->curlft.add_time = (unsigned long)xtime.tv_sec; 635 pol->index = xfrm_gen_index(XFRM_POLICY_MAX+dir); 636 __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir); 637 } 638 if (old_pol) 639 __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir); 640 write_unlock_bh(&xfrm_policy_lock); 641 642 if (old_pol) { 643 xfrm_policy_kill(old_pol); 644 } 645 return 0; 646 } 647 648 static struct xfrm_policy *clone_policy(struct xfrm_policy *old, int dir) 649 { 650 struct xfrm_policy *newp = xfrm_policy_alloc(GFP_ATOMIC); 651 652 if (newp) { 653 newp->selector = old->selector; 654 if (security_xfrm_policy_clone(old, newp)) { 655 kfree(newp); 656 return NULL; /* ENOMEM */ 657 } 658 newp->lft = old->lft; 659 newp->curlft = old->curlft; 660 newp->action = old->action; 661 newp->flags = old->flags; 662 newp->xfrm_nr = old->xfrm_nr; 663 newp->index = old->index; 664 memcpy(newp->xfrm_vec, old->xfrm_vec, 665 newp->xfrm_nr*sizeof(struct xfrm_tmpl)); 666 write_lock_bh(&xfrm_policy_lock); 667 __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir); 668 write_unlock_bh(&xfrm_policy_lock); 669 xfrm_pol_put(newp); 670 } 671 return newp; 672 } 673 674 int __xfrm_sk_clone_policy(struct sock *sk) 675 { 676 struct xfrm_policy *p0 = sk->sk_policy[0], 677 *p1 = sk->sk_policy[1]; 678 679 sk->sk_policy[0] = sk->sk_policy[1] = NULL; 680 if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL) 681 return -ENOMEM; 682 if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL) 683 return -ENOMEM; 684 return 0; 685 } 686 687 /* Resolve list of templates for the flow, given policy. */ 688 689 static int 690 xfrm_tmpl_resolve(struct xfrm_policy *policy, struct flowi *fl, 691 struct xfrm_state **xfrm, 692 unsigned short family) 693 { 694 int nx; 695 int i, error; 696 xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family); 697 xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family); 698 699 for (nx=0, i = 0; i < policy->xfrm_nr; i++) { 700 struct xfrm_state *x; 701 xfrm_address_t *remote = daddr; 702 xfrm_address_t *local = saddr; 703 struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i]; 704 705 if (tmpl->mode) { 706 remote = &tmpl->id.daddr; 707 local = &tmpl->saddr; 708 } 709 710 x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family); 711 712 if (x && x->km.state == XFRM_STATE_VALID) { 713 xfrm[nx++] = x; 714 daddr = remote; 715 saddr = local; 716 continue; 717 } 718 if (x) { 719 error = (x->km.state == XFRM_STATE_ERROR ? 720 -EINVAL : -EAGAIN); 721 xfrm_state_put(x); 722 } 723 724 if (!tmpl->optional) 725 goto fail; 726 } 727 return nx; 728 729 fail: 730 for (nx--; nx>=0; nx--) 731 xfrm_state_put(xfrm[nx]); 732 return error; 733 } 734 735 /* Check that the bundle accepts the flow and its components are 736 * still valid. 737 */ 738 739 static struct dst_entry * 740 xfrm_find_bundle(struct flowi *fl, struct xfrm_policy *policy, unsigned short family) 741 { 742 struct dst_entry *x; 743 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); 744 if (unlikely(afinfo == NULL)) 745 return ERR_PTR(-EINVAL); 746 x = afinfo->find_bundle(fl, policy); 747 xfrm_policy_put_afinfo(afinfo); 748 return x; 749 } 750 751 /* Allocate chain of dst_entry's, attach known xfrm's, calculate 752 * all the metrics... Shortly, bundle a bundle. 753 */ 754 755 static int 756 xfrm_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx, 757 struct flowi *fl, struct dst_entry **dst_p, 758 unsigned short family) 759 { 760 int err; 761 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); 762 if (unlikely(afinfo == NULL)) 763 return -EINVAL; 764 err = afinfo->bundle_create(policy, xfrm, nx, fl, dst_p); 765 xfrm_policy_put_afinfo(afinfo); 766 return err; 767 } 768 769 770 static int stale_bundle(struct dst_entry *dst); 771 772 /* Main function: finds/creates a bundle for given flow. 773 * 774 * At the moment we eat a raw IP route. Mostly to speed up lookups 775 * on interfaces with disabled IPsec. 776 */ 777 int xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl, 778 struct sock *sk, int flags) 779 { 780 struct xfrm_policy *policy; 781 struct xfrm_state *xfrm[XFRM_MAX_DEPTH]; 782 struct dst_entry *dst, *dst_orig = *dst_p; 783 int nx = 0; 784 int err; 785 u32 genid; 786 u16 family; 787 u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT); 788 u32 sk_sid = security_sk_sid(sk, fl, dir); 789 restart: 790 genid = atomic_read(&flow_cache_genid); 791 policy = NULL; 792 if (sk && sk->sk_policy[1]) 793 policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, sk_sid); 794 795 if (!policy) { 796 /* To accelerate a bit... */ 797 if ((dst_orig->flags & DST_NOXFRM) || !xfrm_policy_list[XFRM_POLICY_OUT]) 798 return 0; 799 800 policy = flow_cache_lookup(fl, sk_sid, dst_orig->ops->family, 801 dir, xfrm_policy_lookup); 802 } 803 804 if (!policy) 805 return 0; 806 807 family = dst_orig->ops->family; 808 policy->curlft.use_time = (unsigned long)xtime.tv_sec; 809 810 switch (policy->action) { 811 case XFRM_POLICY_BLOCK: 812 /* Prohibit the flow */ 813 err = -EPERM; 814 goto error; 815 816 case XFRM_POLICY_ALLOW: 817 if (policy->xfrm_nr == 0) { 818 /* Flow passes not transformed. */ 819 xfrm_pol_put(policy); 820 return 0; 821 } 822 823 /* Try to find matching bundle. 824 * 825 * LATER: help from flow cache. It is optional, this 826 * is required only for output policy. 827 */ 828 dst = xfrm_find_bundle(fl, policy, family); 829 if (IS_ERR(dst)) { 830 err = PTR_ERR(dst); 831 goto error; 832 } 833 834 if (dst) 835 break; 836 837 nx = xfrm_tmpl_resolve(policy, fl, xfrm, family); 838 839 if (unlikely(nx<0)) { 840 err = nx; 841 if (err == -EAGAIN && flags) { 842 DECLARE_WAITQUEUE(wait, current); 843 844 add_wait_queue(&km_waitq, &wait); 845 set_current_state(TASK_INTERRUPTIBLE); 846 schedule(); 847 set_current_state(TASK_RUNNING); 848 remove_wait_queue(&km_waitq, &wait); 849 850 nx = xfrm_tmpl_resolve(policy, fl, xfrm, family); 851 852 if (nx == -EAGAIN && signal_pending(current)) { 853 err = -ERESTART; 854 goto error; 855 } 856 if (nx == -EAGAIN || 857 genid != atomic_read(&flow_cache_genid)) { 858 xfrm_pol_put(policy); 859 goto restart; 860 } 861 err = nx; 862 } 863 if (err < 0) 864 goto error; 865 } 866 if (nx == 0) { 867 /* Flow passes not transformed. */ 868 xfrm_pol_put(policy); 869 return 0; 870 } 871 872 dst = dst_orig; 873 err = xfrm_bundle_create(policy, xfrm, nx, fl, &dst, family); 874 875 if (unlikely(err)) { 876 int i; 877 for (i=0; i<nx; i++) 878 xfrm_state_put(xfrm[i]); 879 goto error; 880 } 881 882 write_lock_bh(&policy->lock); 883 if (unlikely(policy->dead || stale_bundle(dst))) { 884 /* Wow! While we worked on resolving, this 885 * policy has gone. Retry. It is not paranoia, 886 * we just cannot enlist new bundle to dead object. 887 * We can't enlist stable bundles either. 888 */ 889 write_unlock_bh(&policy->lock); 890 if (dst) 891 dst_free(dst); 892 893 err = -EHOSTUNREACH; 894 goto error; 895 } 896 dst->next = policy->bundles; 897 policy->bundles = dst; 898 dst_hold(dst); 899 write_unlock_bh(&policy->lock); 900 } 901 *dst_p = dst; 902 dst_release(dst_orig); 903 xfrm_pol_put(policy); 904 return 0; 905 906 error: 907 dst_release(dst_orig); 908 xfrm_pol_put(policy); 909 *dst_p = NULL; 910 return err; 911 } 912 EXPORT_SYMBOL(xfrm_lookup); 913 914 /* When skb is transformed back to its "native" form, we have to 915 * check policy restrictions. At the moment we make this in maximally 916 * stupid way. Shame on me. :-) Of course, connected sockets must 917 * have policy cached at them. 918 */ 919 920 static inline int 921 xfrm_state_ok(struct xfrm_tmpl *tmpl, struct xfrm_state *x, 922 unsigned short family) 923 { 924 if (xfrm_state_kern(x)) 925 return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, family); 926 return x->id.proto == tmpl->id.proto && 927 (x->id.spi == tmpl->id.spi || !tmpl->id.spi) && 928 (x->props.reqid == tmpl->reqid || !tmpl->reqid) && 929 x->props.mode == tmpl->mode && 930 (tmpl->aalgos & (1<<x->props.aalgo)) && 931 !(x->props.mode && xfrm_state_addr_cmp(tmpl, x, family)); 932 } 933 934 static inline int 935 xfrm_policy_ok(struct xfrm_tmpl *tmpl, struct sec_path *sp, int start, 936 unsigned short family) 937 { 938 int idx = start; 939 940 if (tmpl->optional) { 941 if (!tmpl->mode) 942 return start; 943 } else 944 start = -1; 945 for (; idx < sp->len; idx++) { 946 if (xfrm_state_ok(tmpl, sp->xvec[idx], family)) 947 return ++idx; 948 if (sp->xvec[idx]->props.mode) 949 break; 950 } 951 return start; 952 } 953 954 int 955 xfrm_decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family) 956 { 957 struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); 958 959 if (unlikely(afinfo == NULL)) 960 return -EAFNOSUPPORT; 961 962 afinfo->decode_session(skb, fl); 963 xfrm_policy_put_afinfo(afinfo); 964 return 0; 965 } 966 EXPORT_SYMBOL(xfrm_decode_session); 967 968 static inline int secpath_has_tunnel(struct sec_path *sp, int k) 969 { 970 for (; k < sp->len; k++) { 971 if (sp->xvec[k]->props.mode) 972 return 1; 973 } 974 975 return 0; 976 } 977 978 int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, 979 unsigned short family) 980 { 981 struct xfrm_policy *pol; 982 struct flowi fl; 983 u8 fl_dir = policy_to_flow_dir(dir); 984 u32 sk_sid; 985 986 if (xfrm_decode_session(skb, &fl, family) < 0) 987 return 0; 988 nf_nat_decode_session(skb, &fl, family); 989 990 sk_sid = security_sk_sid(sk, &fl, fl_dir); 991 992 /* First, check used SA against their selectors. */ 993 if (skb->sp) { 994 int i; 995 996 for (i=skb->sp->len-1; i>=0; i--) { 997 struct xfrm_state *x = skb->sp->xvec[i]; 998 if (!xfrm_selector_match(&x->sel, &fl, family)) 999 return 0; 1000 } 1001 } 1002 1003 pol = NULL; 1004 if (sk && sk->sk_policy[dir]) 1005 pol = xfrm_sk_policy_lookup(sk, dir, &fl, sk_sid); 1006 1007 if (!pol) 1008 pol = flow_cache_lookup(&fl, sk_sid, family, fl_dir, 1009 xfrm_policy_lookup); 1010 1011 if (!pol) 1012 return !skb->sp || !secpath_has_tunnel(skb->sp, 0); 1013 1014 pol->curlft.use_time = (unsigned long)xtime.tv_sec; 1015 1016 if (pol->action == XFRM_POLICY_ALLOW) { 1017 struct sec_path *sp; 1018 static struct sec_path dummy; 1019 int i, k; 1020 1021 if ((sp = skb->sp) == NULL) 1022 sp = &dummy; 1023 1024 /* For each tunnel xfrm, find the first matching tmpl. 1025 * For each tmpl before that, find corresponding xfrm. 1026 * Order is _important_. Later we will implement 1027 * some barriers, but at the moment barriers 1028 * are implied between each two transformations. 1029 */ 1030 for (i = pol->xfrm_nr-1, k = 0; i >= 0; i--) { 1031 k = xfrm_policy_ok(pol->xfrm_vec+i, sp, k, family); 1032 if (k < 0) 1033 goto reject; 1034 } 1035 1036 if (secpath_has_tunnel(sp, k)) 1037 goto reject; 1038 1039 xfrm_pol_put(pol); 1040 return 1; 1041 } 1042 1043 reject: 1044 xfrm_pol_put(pol); 1045 return 0; 1046 } 1047 EXPORT_SYMBOL(__xfrm_policy_check); 1048 1049 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family) 1050 { 1051 struct flowi fl; 1052 1053 if (xfrm_decode_session(skb, &fl, family) < 0) 1054 return 0; 1055 1056 return xfrm_lookup(&skb->dst, &fl, NULL, 0) == 0; 1057 } 1058 EXPORT_SYMBOL(__xfrm_route_forward); 1059 1060 static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie) 1061 { 1062 /* If it is marked obsolete, which is how we even get here, 1063 * then we have purged it from the policy bundle list and we 1064 * did that for a good reason. 1065 */ 1066 return NULL; 1067 } 1068 1069 static int stale_bundle(struct dst_entry *dst) 1070 { 1071 return !xfrm_bundle_ok((struct xfrm_dst *)dst, NULL, AF_UNSPEC); 1072 } 1073 1074 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev) 1075 { 1076 while ((dst = dst->child) && dst->xfrm && dst->dev == dev) { 1077 dst->dev = &loopback_dev; 1078 dev_hold(&loopback_dev); 1079 dev_put(dev); 1080 } 1081 } 1082 EXPORT_SYMBOL(xfrm_dst_ifdown); 1083 1084 static void xfrm_link_failure(struct sk_buff *skb) 1085 { 1086 /* Impossible. Such dst must be popped before reaches point of failure. */ 1087 return; 1088 } 1089 1090 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst) 1091 { 1092 if (dst) { 1093 if (dst->obsolete) { 1094 dst_release(dst); 1095 dst = NULL; 1096 } 1097 } 1098 return dst; 1099 } 1100 1101 static void xfrm_prune_bundles(int (*func)(struct dst_entry *)) 1102 { 1103 int i; 1104 struct xfrm_policy *pol; 1105 struct dst_entry *dst, **dstp, *gc_list = NULL; 1106 1107 read_lock_bh(&xfrm_policy_lock); 1108 for (i=0; i<2*XFRM_POLICY_MAX; i++) { 1109 for (pol = xfrm_policy_list[i]; pol; pol = pol->next) { 1110 write_lock(&pol->lock); 1111 dstp = &pol->bundles; 1112 while ((dst=*dstp) != NULL) { 1113 if (func(dst)) { 1114 *dstp = dst->next; 1115 dst->next = gc_list; 1116 gc_list = dst; 1117 } else { 1118 dstp = &dst->next; 1119 } 1120 } 1121 write_unlock(&pol->lock); 1122 } 1123 } 1124 read_unlock_bh(&xfrm_policy_lock); 1125 1126 while (gc_list) { 1127 dst = gc_list; 1128 gc_list = dst->next; 1129 dst_free(dst); 1130 } 1131 } 1132 1133 static int unused_bundle(struct dst_entry *dst) 1134 { 1135 return !atomic_read(&dst->__refcnt); 1136 } 1137 1138 static void __xfrm_garbage_collect(void) 1139 { 1140 xfrm_prune_bundles(unused_bundle); 1141 } 1142 1143 int xfrm_flush_bundles(void) 1144 { 1145 xfrm_prune_bundles(stale_bundle); 1146 return 0; 1147 } 1148 1149 static int always_true(struct dst_entry *dst) 1150 { 1151 return 1; 1152 } 1153 1154 void xfrm_flush_all_bundles(void) 1155 { 1156 xfrm_prune_bundles(always_true); 1157 } 1158 1159 void xfrm_init_pmtu(struct dst_entry *dst) 1160 { 1161 do { 1162 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 1163 u32 pmtu, route_mtu_cached; 1164 1165 pmtu = dst_mtu(dst->child); 1166 xdst->child_mtu_cached = pmtu; 1167 1168 pmtu = xfrm_state_mtu(dst->xfrm, pmtu); 1169 1170 route_mtu_cached = dst_mtu(xdst->route); 1171 xdst->route_mtu_cached = route_mtu_cached; 1172 1173 if (pmtu > route_mtu_cached) 1174 pmtu = route_mtu_cached; 1175 1176 dst->metrics[RTAX_MTU-1] = pmtu; 1177 } while ((dst = dst->next)); 1178 } 1179 1180 EXPORT_SYMBOL(xfrm_init_pmtu); 1181 1182 /* Check that the bundle accepts the flow and its components are 1183 * still valid. 1184 */ 1185 1186 int xfrm_bundle_ok(struct xfrm_dst *first, struct flowi *fl, int family) 1187 { 1188 struct dst_entry *dst = &first->u.dst; 1189 struct xfrm_dst *last; 1190 u32 mtu; 1191 1192 if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) || 1193 (dst->dev && !netif_running(dst->dev))) 1194 return 0; 1195 1196 last = NULL; 1197 1198 do { 1199 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 1200 1201 if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family)) 1202 return 0; 1203 if (dst->xfrm->km.state != XFRM_STATE_VALID) 1204 return 0; 1205 1206 mtu = dst_mtu(dst->child); 1207 if (xdst->child_mtu_cached != mtu) { 1208 last = xdst; 1209 xdst->child_mtu_cached = mtu; 1210 } 1211 1212 if (!dst_check(xdst->route, xdst->route_cookie)) 1213 return 0; 1214 mtu = dst_mtu(xdst->route); 1215 if (xdst->route_mtu_cached != mtu) { 1216 last = xdst; 1217 xdst->route_mtu_cached = mtu; 1218 } 1219 1220 dst = dst->child; 1221 } while (dst->xfrm); 1222 1223 if (likely(!last)) 1224 return 1; 1225 1226 mtu = last->child_mtu_cached; 1227 for (;;) { 1228 dst = &last->u.dst; 1229 1230 mtu = xfrm_state_mtu(dst->xfrm, mtu); 1231 if (mtu > last->route_mtu_cached) 1232 mtu = last->route_mtu_cached; 1233 dst->metrics[RTAX_MTU-1] = mtu; 1234 1235 if (last == first) 1236 break; 1237 1238 last = last->u.next; 1239 last->child_mtu_cached = mtu; 1240 } 1241 1242 return 1; 1243 } 1244 1245 EXPORT_SYMBOL(xfrm_bundle_ok); 1246 1247 int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo) 1248 { 1249 int err = 0; 1250 if (unlikely(afinfo == NULL)) 1251 return -EINVAL; 1252 if (unlikely(afinfo->family >= NPROTO)) 1253 return -EAFNOSUPPORT; 1254 write_lock(&xfrm_policy_afinfo_lock); 1255 if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL)) 1256 err = -ENOBUFS; 1257 else { 1258 struct dst_ops *dst_ops = afinfo->dst_ops; 1259 if (likely(dst_ops->kmem_cachep == NULL)) 1260 dst_ops->kmem_cachep = xfrm_dst_cache; 1261 if (likely(dst_ops->check == NULL)) 1262 dst_ops->check = xfrm_dst_check; 1263 if (likely(dst_ops->negative_advice == NULL)) 1264 dst_ops->negative_advice = xfrm_negative_advice; 1265 if (likely(dst_ops->link_failure == NULL)) 1266 dst_ops->link_failure = xfrm_link_failure; 1267 if (likely(afinfo->garbage_collect == NULL)) 1268 afinfo->garbage_collect = __xfrm_garbage_collect; 1269 xfrm_policy_afinfo[afinfo->family] = afinfo; 1270 } 1271 write_unlock(&xfrm_policy_afinfo_lock); 1272 return err; 1273 } 1274 EXPORT_SYMBOL(xfrm_policy_register_afinfo); 1275 1276 int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo) 1277 { 1278 int err = 0; 1279 if (unlikely(afinfo == NULL)) 1280 return -EINVAL; 1281 if (unlikely(afinfo->family >= NPROTO)) 1282 return -EAFNOSUPPORT; 1283 write_lock(&xfrm_policy_afinfo_lock); 1284 if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) { 1285 if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo)) 1286 err = -EINVAL; 1287 else { 1288 struct dst_ops *dst_ops = afinfo->dst_ops; 1289 xfrm_policy_afinfo[afinfo->family] = NULL; 1290 dst_ops->kmem_cachep = NULL; 1291 dst_ops->check = NULL; 1292 dst_ops->negative_advice = NULL; 1293 dst_ops->link_failure = NULL; 1294 afinfo->garbage_collect = NULL; 1295 } 1296 } 1297 write_unlock(&xfrm_policy_afinfo_lock); 1298 return err; 1299 } 1300 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo); 1301 1302 static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family) 1303 { 1304 struct xfrm_policy_afinfo *afinfo; 1305 if (unlikely(family >= NPROTO)) 1306 return NULL; 1307 read_lock(&xfrm_policy_afinfo_lock); 1308 afinfo = xfrm_policy_afinfo[family]; 1309 if (likely(afinfo != NULL)) 1310 read_lock(&afinfo->lock); 1311 read_unlock(&xfrm_policy_afinfo_lock); 1312 return afinfo; 1313 } 1314 1315 static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo) 1316 { 1317 if (unlikely(afinfo == NULL)) 1318 return; 1319 read_unlock(&afinfo->lock); 1320 } 1321 1322 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr) 1323 { 1324 switch (event) { 1325 case NETDEV_DOWN: 1326 xfrm_flush_bundles(); 1327 } 1328 return NOTIFY_DONE; 1329 } 1330 1331 static struct notifier_block xfrm_dev_notifier = { 1332 xfrm_dev_event, 1333 NULL, 1334 0 1335 }; 1336 1337 static void __init xfrm_policy_init(void) 1338 { 1339 xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache", 1340 sizeof(struct xfrm_dst), 1341 0, SLAB_HWCACHE_ALIGN, 1342 NULL, NULL); 1343 if (!xfrm_dst_cache) 1344 panic("XFRM: failed to allocate xfrm_dst_cache\n"); 1345 1346 INIT_WORK(&xfrm_policy_gc_work, xfrm_policy_gc_task, NULL); 1347 register_netdevice_notifier(&xfrm_dev_notifier); 1348 } 1349 1350 void __init xfrm_init(void) 1351 { 1352 xfrm_state_init(); 1353 xfrm_policy_init(); 1354 xfrm_input_init(); 1355 } 1356 1357