1 /* netfilter.c: look after the filters for various protocols. 2 * Heavily influenced by the old firewall.c by David Bonn and Alan Cox. 3 * 4 * Thanks to Rob `CmdrTaco' Malda for not influencing this code in any 5 * way. 6 * 7 * This code is GPL. 8 */ 9 #include <linux/kernel.h> 10 #include <linux/netfilter.h> 11 #include <net/protocol.h> 12 #include <linux/init.h> 13 #include <linux/skbuff.h> 14 #include <linux/wait.h> 15 #include <linux/module.h> 16 #include <linux/interrupt.h> 17 #include <linux/if.h> 18 #include <linux/netdevice.h> 19 #include <linux/netfilter_ipv6.h> 20 #include <linux/inetdevice.h> 21 #include <linux/proc_fs.h> 22 #include <linux/mutex.h> 23 #include <linux/mm.h> 24 #include <linux/rcupdate.h> 25 #include <net/net_namespace.h> 26 #include <net/netfilter/nf_queue.h> 27 #include <net/sock.h> 28 29 #include "nf_internals.h" 30 31 const struct nf_ipv6_ops __rcu *nf_ipv6_ops __read_mostly; 32 EXPORT_SYMBOL_GPL(nf_ipv6_ops); 33 34 DEFINE_PER_CPU(bool, nf_skb_duplicated); 35 EXPORT_SYMBOL_GPL(nf_skb_duplicated); 36 37 #ifdef CONFIG_JUMP_LABEL 38 struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS]; 39 EXPORT_SYMBOL(nf_hooks_needed); 40 #endif 41 42 static DEFINE_MUTEX(nf_hook_mutex); 43 44 /* max hooks per family/hooknum */ 45 #define MAX_HOOK_COUNT 1024 46 47 #define nf_entry_dereference(e) \ 48 rcu_dereference_protected(e, lockdep_is_held(&nf_hook_mutex)) 49 50 static struct nf_hook_entries *allocate_hook_entries_size(u16 num) 51 { 52 struct nf_hook_entries *e; 53 size_t alloc = sizeof(*e) + 54 sizeof(struct nf_hook_entry) * num + 55 sizeof(struct nf_hook_ops *) * num + 56 sizeof(struct nf_hook_entries_rcu_head); 57 58 if (num == 0) 59 return NULL; 60 61 e = kvzalloc(alloc, GFP_KERNEL_ACCOUNT); 62 if (e) 63 e->num_hook_entries = num; 64 return e; 65 } 66 67 static void __nf_hook_entries_free(struct rcu_head *h) 68 { 69 struct nf_hook_entries_rcu_head *head; 70 71 head = container_of(h, struct nf_hook_entries_rcu_head, head); 72 kvfree(head->allocation); 73 } 74 75 static void nf_hook_entries_free(struct nf_hook_entries *e) 76 { 77 struct nf_hook_entries_rcu_head *head; 78 struct nf_hook_ops **ops; 79 unsigned int num; 80 81 if (!e) 82 return; 83 84 num = e->num_hook_entries; 85 ops = nf_hook_entries_get_hook_ops(e); 86 head = (void *)&ops[num]; 87 head->allocation = e; 88 call_rcu(&head->head, __nf_hook_entries_free); 89 } 90 91 static unsigned int accept_all(void *priv, 92 struct sk_buff *skb, 93 const struct nf_hook_state *state) 94 { 95 return NF_ACCEPT; /* ACCEPT makes nf_hook_slow call next hook */ 96 } 97 98 static const struct nf_hook_ops dummy_ops = { 99 .hook = accept_all, 100 .priority = INT_MIN, 101 }; 102 103 static struct nf_hook_entries * 104 nf_hook_entries_grow(const struct nf_hook_entries *old, 105 const struct nf_hook_ops *reg) 106 { 107 unsigned int i, alloc_entries, nhooks, old_entries; 108 struct nf_hook_ops **orig_ops = NULL; 109 struct nf_hook_ops **new_ops; 110 struct nf_hook_entries *new; 111 bool inserted = false; 112 113 alloc_entries = 1; 114 old_entries = old ? old->num_hook_entries : 0; 115 116 if (old) { 117 orig_ops = nf_hook_entries_get_hook_ops(old); 118 119 for (i = 0; i < old_entries; i++) { 120 if (orig_ops[i] != &dummy_ops) 121 alloc_entries++; 122 } 123 } 124 125 if (alloc_entries > MAX_HOOK_COUNT) 126 return ERR_PTR(-E2BIG); 127 128 new = allocate_hook_entries_size(alloc_entries); 129 if (!new) 130 return ERR_PTR(-ENOMEM); 131 132 new_ops = nf_hook_entries_get_hook_ops(new); 133 134 i = 0; 135 nhooks = 0; 136 while (i < old_entries) { 137 if (orig_ops[i] == &dummy_ops) { 138 ++i; 139 continue; 140 } 141 142 if (inserted || reg->priority > orig_ops[i]->priority) { 143 new_ops[nhooks] = (void *)orig_ops[i]; 144 new->hooks[nhooks] = old->hooks[i]; 145 i++; 146 } else { 147 new_ops[nhooks] = (void *)reg; 148 new->hooks[nhooks].hook = reg->hook; 149 new->hooks[nhooks].priv = reg->priv; 150 inserted = true; 151 } 152 nhooks++; 153 } 154 155 if (!inserted) { 156 new_ops[nhooks] = (void *)reg; 157 new->hooks[nhooks].hook = reg->hook; 158 new->hooks[nhooks].priv = reg->priv; 159 } 160 161 return new; 162 } 163 164 static void hooks_validate(const struct nf_hook_entries *hooks) 165 { 166 #ifdef CONFIG_DEBUG_MISC 167 struct nf_hook_ops **orig_ops; 168 int prio = INT_MIN; 169 size_t i = 0; 170 171 orig_ops = nf_hook_entries_get_hook_ops(hooks); 172 173 for (i = 0; i < hooks->num_hook_entries; i++) { 174 if (orig_ops[i] == &dummy_ops) 175 continue; 176 177 WARN_ON(orig_ops[i]->priority < prio); 178 179 if (orig_ops[i]->priority > prio) 180 prio = orig_ops[i]->priority; 181 } 182 #endif 183 } 184 185 int nf_hook_entries_insert_raw(struct nf_hook_entries __rcu **pp, 186 const struct nf_hook_ops *reg) 187 { 188 struct nf_hook_entries *new_hooks; 189 struct nf_hook_entries *p; 190 191 p = rcu_dereference_raw(*pp); 192 new_hooks = nf_hook_entries_grow(p, reg); 193 if (IS_ERR(new_hooks)) 194 return PTR_ERR(new_hooks); 195 196 hooks_validate(new_hooks); 197 198 rcu_assign_pointer(*pp, new_hooks); 199 200 BUG_ON(p == new_hooks); 201 nf_hook_entries_free(p); 202 return 0; 203 } 204 EXPORT_SYMBOL_GPL(nf_hook_entries_insert_raw); 205 206 /* 207 * __nf_hook_entries_try_shrink - try to shrink hook array 208 * 209 * @old -- current hook blob at @pp 210 * @pp -- location of hook blob 211 * 212 * Hook unregistration must always succeed, so to-be-removed hooks 213 * are replaced by a dummy one that will just move to next hook. 214 * 215 * This counts the current dummy hooks, attempts to allocate new blob, 216 * copies the live hooks, then replaces and discards old one. 217 * 218 * return values: 219 * 220 * Returns address to free, or NULL. 221 */ 222 static void *__nf_hook_entries_try_shrink(struct nf_hook_entries *old, 223 struct nf_hook_entries __rcu **pp) 224 { 225 unsigned int i, j, skip = 0, hook_entries; 226 struct nf_hook_entries *new = NULL; 227 struct nf_hook_ops **orig_ops; 228 struct nf_hook_ops **new_ops; 229 230 if (WARN_ON_ONCE(!old)) 231 return NULL; 232 233 orig_ops = nf_hook_entries_get_hook_ops(old); 234 for (i = 0; i < old->num_hook_entries; i++) { 235 if (orig_ops[i] == &dummy_ops) 236 skip++; 237 } 238 239 /* if skip == hook_entries all hooks have been removed */ 240 hook_entries = old->num_hook_entries; 241 if (skip == hook_entries) 242 goto out_assign; 243 244 if (skip == 0) 245 return NULL; 246 247 hook_entries -= skip; 248 new = allocate_hook_entries_size(hook_entries); 249 if (!new) 250 return NULL; 251 252 new_ops = nf_hook_entries_get_hook_ops(new); 253 for (i = 0, j = 0; i < old->num_hook_entries; i++) { 254 if (orig_ops[i] == &dummy_ops) 255 continue; 256 new->hooks[j] = old->hooks[i]; 257 new_ops[j] = (void *)orig_ops[i]; 258 j++; 259 } 260 hooks_validate(new); 261 out_assign: 262 rcu_assign_pointer(*pp, new); 263 return old; 264 } 265 266 static struct nf_hook_entries __rcu ** 267 nf_hook_entry_head(struct net *net, int pf, unsigned int hooknum, 268 struct net_device *dev) 269 { 270 switch (pf) { 271 case NFPROTO_NETDEV: 272 break; 273 #ifdef CONFIG_NETFILTER_FAMILY_ARP 274 case NFPROTO_ARP: 275 if (WARN_ON_ONCE(ARRAY_SIZE(net->nf.hooks_arp) <= hooknum)) 276 return NULL; 277 return net->nf.hooks_arp + hooknum; 278 #endif 279 #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE 280 case NFPROTO_BRIDGE: 281 if (WARN_ON_ONCE(ARRAY_SIZE(net->nf.hooks_bridge) <= hooknum)) 282 return NULL; 283 return net->nf.hooks_bridge + hooknum; 284 #endif 285 #ifdef CONFIG_NETFILTER_INGRESS 286 case NFPROTO_INET: 287 if (WARN_ON_ONCE(hooknum != NF_INET_INGRESS)) 288 return NULL; 289 if (!dev || dev_net(dev) != net) { 290 WARN_ON_ONCE(1); 291 return NULL; 292 } 293 return &dev->nf_hooks_ingress; 294 #endif 295 case NFPROTO_IPV4: 296 if (WARN_ON_ONCE(ARRAY_SIZE(net->nf.hooks_ipv4) <= hooknum)) 297 return NULL; 298 return net->nf.hooks_ipv4 + hooknum; 299 case NFPROTO_IPV6: 300 if (WARN_ON_ONCE(ARRAY_SIZE(net->nf.hooks_ipv6) <= hooknum)) 301 return NULL; 302 return net->nf.hooks_ipv6 + hooknum; 303 #if IS_ENABLED(CONFIG_DECNET) 304 case NFPROTO_DECNET: 305 if (WARN_ON_ONCE(ARRAY_SIZE(net->nf.hooks_decnet) <= hooknum)) 306 return NULL; 307 return net->nf.hooks_decnet + hooknum; 308 #endif 309 default: 310 WARN_ON_ONCE(1); 311 return NULL; 312 } 313 314 #ifdef CONFIG_NETFILTER_INGRESS 315 if (hooknum == NF_NETDEV_INGRESS) { 316 if (dev && dev_net(dev) == net) 317 return &dev->nf_hooks_ingress; 318 } 319 #endif 320 #ifdef CONFIG_NETFILTER_EGRESS 321 if (hooknum == NF_NETDEV_EGRESS) { 322 if (dev && dev_net(dev) == net) 323 return &dev->nf_hooks_egress; 324 } 325 #endif 326 WARN_ON_ONCE(1); 327 return NULL; 328 } 329 330 static int nf_ingress_check(struct net *net, const struct nf_hook_ops *reg, 331 int hooknum) 332 { 333 #ifndef CONFIG_NETFILTER_INGRESS 334 if (reg->hooknum == hooknum) 335 return -EOPNOTSUPP; 336 #endif 337 if (reg->hooknum != hooknum || 338 !reg->dev || dev_net(reg->dev) != net) 339 return -EINVAL; 340 341 return 0; 342 } 343 344 static inline bool __maybe_unused nf_ingress_hook(const struct nf_hook_ops *reg, 345 int pf) 346 { 347 if ((pf == NFPROTO_NETDEV && reg->hooknum == NF_NETDEV_INGRESS) || 348 (pf == NFPROTO_INET && reg->hooknum == NF_INET_INGRESS)) 349 return true; 350 351 return false; 352 } 353 354 static inline bool __maybe_unused nf_egress_hook(const struct nf_hook_ops *reg, 355 int pf) 356 { 357 return pf == NFPROTO_NETDEV && reg->hooknum == NF_NETDEV_EGRESS; 358 } 359 360 static void nf_static_key_inc(const struct nf_hook_ops *reg, int pf) 361 { 362 #ifdef CONFIG_JUMP_LABEL 363 int hooknum; 364 365 if (pf == NFPROTO_INET && reg->hooknum == NF_INET_INGRESS) { 366 pf = NFPROTO_NETDEV; 367 hooknum = NF_NETDEV_INGRESS; 368 } else { 369 hooknum = reg->hooknum; 370 } 371 static_key_slow_inc(&nf_hooks_needed[pf][hooknum]); 372 #endif 373 } 374 375 static void nf_static_key_dec(const struct nf_hook_ops *reg, int pf) 376 { 377 #ifdef CONFIG_JUMP_LABEL 378 int hooknum; 379 380 if (pf == NFPROTO_INET && reg->hooknum == NF_INET_INGRESS) { 381 pf = NFPROTO_NETDEV; 382 hooknum = NF_NETDEV_INGRESS; 383 } else { 384 hooknum = reg->hooknum; 385 } 386 static_key_slow_dec(&nf_hooks_needed[pf][hooknum]); 387 #endif 388 } 389 390 static int __nf_register_net_hook(struct net *net, int pf, 391 const struct nf_hook_ops *reg) 392 { 393 struct nf_hook_entries *p, *new_hooks; 394 struct nf_hook_entries __rcu **pp; 395 int err; 396 397 switch (pf) { 398 case NFPROTO_NETDEV: 399 #ifndef CONFIG_NETFILTER_INGRESS 400 if (reg->hooknum == NF_NETDEV_INGRESS) 401 return -EOPNOTSUPP; 402 #endif 403 #ifndef CONFIG_NETFILTER_EGRESS 404 if (reg->hooknum == NF_NETDEV_EGRESS) 405 return -EOPNOTSUPP; 406 #endif 407 if ((reg->hooknum != NF_NETDEV_INGRESS && 408 reg->hooknum != NF_NETDEV_EGRESS) || 409 !reg->dev || dev_net(reg->dev) != net) 410 return -EINVAL; 411 break; 412 case NFPROTO_INET: 413 if (reg->hooknum != NF_INET_INGRESS) 414 break; 415 416 err = nf_ingress_check(net, reg, NF_INET_INGRESS); 417 if (err < 0) 418 return err; 419 break; 420 } 421 422 pp = nf_hook_entry_head(net, pf, reg->hooknum, reg->dev); 423 if (!pp) 424 return -EINVAL; 425 426 mutex_lock(&nf_hook_mutex); 427 428 p = nf_entry_dereference(*pp); 429 new_hooks = nf_hook_entries_grow(p, reg); 430 431 if (!IS_ERR(new_hooks)) { 432 hooks_validate(new_hooks); 433 rcu_assign_pointer(*pp, new_hooks); 434 } 435 436 mutex_unlock(&nf_hook_mutex); 437 if (IS_ERR(new_hooks)) 438 return PTR_ERR(new_hooks); 439 440 #ifdef CONFIG_NETFILTER_INGRESS 441 if (nf_ingress_hook(reg, pf)) 442 net_inc_ingress_queue(); 443 #endif 444 #ifdef CONFIG_NETFILTER_EGRESS 445 if (nf_egress_hook(reg, pf)) 446 net_inc_egress_queue(); 447 #endif 448 nf_static_key_inc(reg, pf); 449 450 BUG_ON(p == new_hooks); 451 nf_hook_entries_free(p); 452 return 0; 453 } 454 455 /* 456 * nf_remove_net_hook - remove a hook from blob 457 * 458 * @oldp: current address of hook blob 459 * @unreg: hook to unregister 460 * 461 * This cannot fail, hook unregistration must always succeed. 462 * Therefore replace the to-be-removed hook with a dummy hook. 463 */ 464 static bool nf_remove_net_hook(struct nf_hook_entries *old, 465 const struct nf_hook_ops *unreg) 466 { 467 struct nf_hook_ops **orig_ops; 468 unsigned int i; 469 470 orig_ops = nf_hook_entries_get_hook_ops(old); 471 for (i = 0; i < old->num_hook_entries; i++) { 472 if (orig_ops[i] != unreg) 473 continue; 474 WRITE_ONCE(old->hooks[i].hook, accept_all); 475 WRITE_ONCE(orig_ops[i], (void *)&dummy_ops); 476 return true; 477 } 478 479 return false; 480 } 481 482 static void __nf_unregister_net_hook(struct net *net, int pf, 483 const struct nf_hook_ops *reg) 484 { 485 struct nf_hook_entries __rcu **pp; 486 struct nf_hook_entries *p; 487 488 pp = nf_hook_entry_head(net, pf, reg->hooknum, reg->dev); 489 if (!pp) 490 return; 491 492 mutex_lock(&nf_hook_mutex); 493 494 p = nf_entry_dereference(*pp); 495 if (WARN_ON_ONCE(!p)) { 496 mutex_unlock(&nf_hook_mutex); 497 return; 498 } 499 500 if (nf_remove_net_hook(p, reg)) { 501 #ifdef CONFIG_NETFILTER_INGRESS 502 if (nf_ingress_hook(reg, pf)) 503 net_dec_ingress_queue(); 504 #endif 505 #ifdef CONFIG_NETFILTER_EGRESS 506 if (nf_egress_hook(reg, pf)) 507 net_dec_egress_queue(); 508 #endif 509 nf_static_key_dec(reg, pf); 510 } else { 511 WARN_ONCE(1, "hook not found, pf %d num %d", pf, reg->hooknum); 512 } 513 514 p = __nf_hook_entries_try_shrink(p, pp); 515 mutex_unlock(&nf_hook_mutex); 516 if (!p) 517 return; 518 519 nf_queue_nf_hook_drop(net); 520 nf_hook_entries_free(p); 521 } 522 523 void nf_unregister_net_hook(struct net *net, const struct nf_hook_ops *reg) 524 { 525 if (reg->pf == NFPROTO_INET) { 526 if (reg->hooknum == NF_INET_INGRESS) { 527 __nf_unregister_net_hook(net, NFPROTO_INET, reg); 528 } else { 529 __nf_unregister_net_hook(net, NFPROTO_IPV4, reg); 530 __nf_unregister_net_hook(net, NFPROTO_IPV6, reg); 531 } 532 } else { 533 __nf_unregister_net_hook(net, reg->pf, reg); 534 } 535 } 536 EXPORT_SYMBOL(nf_unregister_net_hook); 537 538 void nf_hook_entries_delete_raw(struct nf_hook_entries __rcu **pp, 539 const struct nf_hook_ops *reg) 540 { 541 struct nf_hook_entries *p; 542 543 p = rcu_dereference_raw(*pp); 544 if (nf_remove_net_hook(p, reg)) { 545 p = __nf_hook_entries_try_shrink(p, pp); 546 nf_hook_entries_free(p); 547 } 548 } 549 EXPORT_SYMBOL_GPL(nf_hook_entries_delete_raw); 550 551 int nf_register_net_hook(struct net *net, const struct nf_hook_ops *reg) 552 { 553 int err; 554 555 if (reg->pf == NFPROTO_INET) { 556 if (reg->hooknum == NF_INET_INGRESS) { 557 err = __nf_register_net_hook(net, NFPROTO_INET, reg); 558 if (err < 0) 559 return err; 560 } else { 561 err = __nf_register_net_hook(net, NFPROTO_IPV4, reg); 562 if (err < 0) 563 return err; 564 565 err = __nf_register_net_hook(net, NFPROTO_IPV6, reg); 566 if (err < 0) { 567 __nf_unregister_net_hook(net, NFPROTO_IPV4, reg); 568 return err; 569 } 570 } 571 } else { 572 err = __nf_register_net_hook(net, reg->pf, reg); 573 if (err < 0) 574 return err; 575 } 576 577 return 0; 578 } 579 EXPORT_SYMBOL(nf_register_net_hook); 580 581 int nf_register_net_hooks(struct net *net, const struct nf_hook_ops *reg, 582 unsigned int n) 583 { 584 unsigned int i; 585 int err = 0; 586 587 for (i = 0; i < n; i++) { 588 err = nf_register_net_hook(net, ®[i]); 589 if (err) 590 goto err; 591 } 592 return err; 593 594 err: 595 if (i > 0) 596 nf_unregister_net_hooks(net, reg, i); 597 return err; 598 } 599 EXPORT_SYMBOL(nf_register_net_hooks); 600 601 void nf_unregister_net_hooks(struct net *net, const struct nf_hook_ops *reg, 602 unsigned int hookcount) 603 { 604 unsigned int i; 605 606 for (i = 0; i < hookcount; i++) 607 nf_unregister_net_hook(net, ®[i]); 608 } 609 EXPORT_SYMBOL(nf_unregister_net_hooks); 610 611 /* Returns 1 if okfn() needs to be executed by the caller, 612 * -EPERM for NF_DROP, 0 otherwise. Caller must hold rcu_read_lock. */ 613 int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state, 614 const struct nf_hook_entries *e, unsigned int s) 615 { 616 unsigned int verdict; 617 int ret; 618 619 for (; s < e->num_hook_entries; s++) { 620 verdict = nf_hook_entry_hookfn(&e->hooks[s], skb, state); 621 switch (verdict & NF_VERDICT_MASK) { 622 case NF_ACCEPT: 623 break; 624 case NF_DROP: 625 kfree_skb_reason(skb, 626 SKB_DROP_REASON_NETFILTER_DROP); 627 ret = NF_DROP_GETERR(verdict); 628 if (ret == 0) 629 ret = -EPERM; 630 return ret; 631 case NF_QUEUE: 632 ret = nf_queue(skb, state, s, verdict); 633 if (ret == 1) 634 continue; 635 return ret; 636 default: 637 /* Implicit handling for NF_STOLEN, as well as any other 638 * non conventional verdicts. 639 */ 640 return 0; 641 } 642 } 643 644 return 1; 645 } 646 EXPORT_SYMBOL(nf_hook_slow); 647 648 void nf_hook_slow_list(struct list_head *head, struct nf_hook_state *state, 649 const struct nf_hook_entries *e) 650 { 651 struct sk_buff *skb, *next; 652 struct list_head sublist; 653 int ret; 654 655 INIT_LIST_HEAD(&sublist); 656 657 list_for_each_entry_safe(skb, next, head, list) { 658 skb_list_del_init(skb); 659 ret = nf_hook_slow(skb, state, e, 0); 660 if (ret == 1) 661 list_add_tail(&skb->list, &sublist); 662 } 663 /* Put passed packets back on main list */ 664 list_splice(&sublist, head); 665 } 666 EXPORT_SYMBOL(nf_hook_slow_list); 667 668 /* This needs to be compiled in any case to avoid dependencies between the 669 * nfnetlink_queue code and nf_conntrack. 670 */ 671 const struct nfnl_ct_hook __rcu *nfnl_ct_hook __read_mostly; 672 EXPORT_SYMBOL_GPL(nfnl_ct_hook); 673 674 const struct nf_ct_hook __rcu *nf_ct_hook __read_mostly; 675 EXPORT_SYMBOL_GPL(nf_ct_hook); 676 677 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 678 const struct nf_nat_hook __rcu *nf_nat_hook __read_mostly; 679 EXPORT_SYMBOL_GPL(nf_nat_hook); 680 681 /* This does not belong here, but locally generated errors need it if connection 682 * tracking in use: without this, connection may not be in hash table, and hence 683 * manufactured ICMP or RST packets will not be associated with it. 684 */ 685 void nf_ct_attach(struct sk_buff *new, const struct sk_buff *skb) 686 { 687 const struct nf_ct_hook *ct_hook; 688 689 if (skb->_nfct) { 690 rcu_read_lock(); 691 ct_hook = rcu_dereference(nf_ct_hook); 692 if (ct_hook) 693 ct_hook->attach(new, skb); 694 rcu_read_unlock(); 695 } 696 } 697 EXPORT_SYMBOL(nf_ct_attach); 698 699 void nf_conntrack_destroy(struct nf_conntrack *nfct) 700 { 701 const struct nf_ct_hook *ct_hook; 702 703 rcu_read_lock(); 704 ct_hook = rcu_dereference(nf_ct_hook); 705 BUG_ON(ct_hook == NULL); 706 ct_hook->destroy(nfct); 707 rcu_read_unlock(); 708 } 709 EXPORT_SYMBOL(nf_conntrack_destroy); 710 711 bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple, 712 const struct sk_buff *skb) 713 { 714 const struct nf_ct_hook *ct_hook; 715 bool ret = false; 716 717 rcu_read_lock(); 718 ct_hook = rcu_dereference(nf_ct_hook); 719 if (ct_hook) 720 ret = ct_hook->get_tuple_skb(dst_tuple, skb); 721 rcu_read_unlock(); 722 return ret; 723 } 724 EXPORT_SYMBOL(nf_ct_get_tuple_skb); 725 726 /* Built-in default zone used e.g. by modules. */ 727 const struct nf_conntrack_zone nf_ct_zone_dflt = { 728 .id = NF_CT_DEFAULT_ZONE_ID, 729 .dir = NF_CT_DEFAULT_ZONE_DIR, 730 }; 731 EXPORT_SYMBOL_GPL(nf_ct_zone_dflt); 732 #endif /* CONFIG_NF_CONNTRACK */ 733 734 static void __net_init 735 __netfilter_net_init(struct nf_hook_entries __rcu **e, int max) 736 { 737 int h; 738 739 for (h = 0; h < max; h++) 740 RCU_INIT_POINTER(e[h], NULL); 741 } 742 743 static int __net_init netfilter_net_init(struct net *net) 744 { 745 __netfilter_net_init(net->nf.hooks_ipv4, ARRAY_SIZE(net->nf.hooks_ipv4)); 746 __netfilter_net_init(net->nf.hooks_ipv6, ARRAY_SIZE(net->nf.hooks_ipv6)); 747 #ifdef CONFIG_NETFILTER_FAMILY_ARP 748 __netfilter_net_init(net->nf.hooks_arp, ARRAY_SIZE(net->nf.hooks_arp)); 749 #endif 750 #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE 751 __netfilter_net_init(net->nf.hooks_bridge, ARRAY_SIZE(net->nf.hooks_bridge)); 752 #endif 753 #if IS_ENABLED(CONFIG_DECNET) 754 __netfilter_net_init(net->nf.hooks_decnet, ARRAY_SIZE(net->nf.hooks_decnet)); 755 #endif 756 757 #ifdef CONFIG_PROC_FS 758 net->nf.proc_netfilter = proc_net_mkdir(net, "netfilter", 759 net->proc_net); 760 if (!net->nf.proc_netfilter) { 761 if (!net_eq(net, &init_net)) 762 pr_err("cannot create netfilter proc entry"); 763 764 return -ENOMEM; 765 } 766 #endif 767 768 return 0; 769 } 770 771 static void __net_exit netfilter_net_exit(struct net *net) 772 { 773 remove_proc_entry("netfilter", net->proc_net); 774 } 775 776 static struct pernet_operations netfilter_net_ops = { 777 .init = netfilter_net_init, 778 .exit = netfilter_net_exit, 779 }; 780 781 int __init netfilter_init(void) 782 { 783 int ret; 784 785 ret = register_pernet_subsys(&netfilter_net_ops); 786 if (ret < 0) 787 goto err; 788 789 ret = netfilter_log_init(); 790 if (ret < 0) 791 goto err_pernet; 792 793 return 0; 794 err_pernet: 795 unregister_pernet_subsys(&netfilter_net_ops); 796 err: 797 return ret; 798 } 799