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); 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 rcu_assign_pointer(*pp, new_hooks); 433 434 mutex_unlock(&nf_hook_mutex); 435 if (IS_ERR(new_hooks)) 436 return PTR_ERR(new_hooks); 437 438 hooks_validate(new_hooks); 439 #ifdef CONFIG_NETFILTER_INGRESS 440 if (nf_ingress_hook(reg, pf)) 441 net_inc_ingress_queue(); 442 #endif 443 #ifdef CONFIG_NETFILTER_EGRESS 444 if (nf_egress_hook(reg, pf)) 445 net_inc_egress_queue(); 446 #endif 447 nf_static_key_inc(reg, pf); 448 449 BUG_ON(p == new_hooks); 450 nf_hook_entries_free(p); 451 return 0; 452 } 453 454 /* 455 * nf_remove_net_hook - remove a hook from blob 456 * 457 * @oldp: current address of hook blob 458 * @unreg: hook to unregister 459 * 460 * This cannot fail, hook unregistration must always succeed. 461 * Therefore replace the to-be-removed hook with a dummy hook. 462 */ 463 static bool nf_remove_net_hook(struct nf_hook_entries *old, 464 const struct nf_hook_ops *unreg) 465 { 466 struct nf_hook_ops **orig_ops; 467 unsigned int i; 468 469 orig_ops = nf_hook_entries_get_hook_ops(old); 470 for (i = 0; i < old->num_hook_entries; i++) { 471 if (orig_ops[i] != unreg) 472 continue; 473 WRITE_ONCE(old->hooks[i].hook, accept_all); 474 WRITE_ONCE(orig_ops[i], (void *)&dummy_ops); 475 return true; 476 } 477 478 return false; 479 } 480 481 static void __nf_unregister_net_hook(struct net *net, int pf, 482 const struct nf_hook_ops *reg) 483 { 484 struct nf_hook_entries __rcu **pp; 485 struct nf_hook_entries *p; 486 487 pp = nf_hook_entry_head(net, pf, reg->hooknum, reg->dev); 488 if (!pp) 489 return; 490 491 mutex_lock(&nf_hook_mutex); 492 493 p = nf_entry_dereference(*pp); 494 if (WARN_ON_ONCE(!p)) { 495 mutex_unlock(&nf_hook_mutex); 496 return; 497 } 498 499 if (nf_remove_net_hook(p, reg)) { 500 #ifdef CONFIG_NETFILTER_INGRESS 501 if (nf_ingress_hook(reg, pf)) 502 net_dec_ingress_queue(); 503 #endif 504 #ifdef CONFIG_NETFILTER_EGRESS 505 if (nf_egress_hook(reg, pf)) 506 net_dec_egress_queue(); 507 #endif 508 nf_static_key_dec(reg, pf); 509 } else { 510 WARN_ONCE(1, "hook not found, pf %d num %d", pf, reg->hooknum); 511 } 512 513 p = __nf_hook_entries_try_shrink(p, pp); 514 mutex_unlock(&nf_hook_mutex); 515 if (!p) 516 return; 517 518 nf_queue_nf_hook_drop(net); 519 nf_hook_entries_free(p); 520 } 521 522 void nf_unregister_net_hook(struct net *net, const struct nf_hook_ops *reg) 523 { 524 if (reg->pf == NFPROTO_INET) { 525 if (reg->hooknum == NF_INET_INGRESS) { 526 __nf_unregister_net_hook(net, NFPROTO_INET, reg); 527 } else { 528 __nf_unregister_net_hook(net, NFPROTO_IPV4, reg); 529 __nf_unregister_net_hook(net, NFPROTO_IPV6, reg); 530 } 531 } else { 532 __nf_unregister_net_hook(net, reg->pf, reg); 533 } 534 } 535 EXPORT_SYMBOL(nf_unregister_net_hook); 536 537 void nf_hook_entries_delete_raw(struct nf_hook_entries __rcu **pp, 538 const struct nf_hook_ops *reg) 539 { 540 struct nf_hook_entries *p; 541 542 p = rcu_dereference_raw(*pp); 543 if (nf_remove_net_hook(p, reg)) { 544 p = __nf_hook_entries_try_shrink(p, pp); 545 nf_hook_entries_free(p); 546 } 547 } 548 EXPORT_SYMBOL_GPL(nf_hook_entries_delete_raw); 549 550 int nf_register_net_hook(struct net *net, const struct nf_hook_ops *reg) 551 { 552 int err; 553 554 if (reg->pf == NFPROTO_INET) { 555 if (reg->hooknum == NF_INET_INGRESS) { 556 err = __nf_register_net_hook(net, NFPROTO_INET, reg); 557 if (err < 0) 558 return err; 559 } else { 560 err = __nf_register_net_hook(net, NFPROTO_IPV4, reg); 561 if (err < 0) 562 return err; 563 564 err = __nf_register_net_hook(net, NFPROTO_IPV6, reg); 565 if (err < 0) { 566 __nf_unregister_net_hook(net, NFPROTO_IPV4, reg); 567 return err; 568 } 569 } 570 } else { 571 err = __nf_register_net_hook(net, reg->pf, reg); 572 if (err < 0) 573 return err; 574 } 575 576 return 0; 577 } 578 EXPORT_SYMBOL(nf_register_net_hook); 579 580 int nf_register_net_hooks(struct net *net, const struct nf_hook_ops *reg, 581 unsigned int n) 582 { 583 unsigned int i; 584 int err = 0; 585 586 for (i = 0; i < n; i++) { 587 err = nf_register_net_hook(net, ®[i]); 588 if (err) 589 goto err; 590 } 591 return err; 592 593 err: 594 if (i > 0) 595 nf_unregister_net_hooks(net, reg, i); 596 return err; 597 } 598 EXPORT_SYMBOL(nf_register_net_hooks); 599 600 void nf_unregister_net_hooks(struct net *net, const struct nf_hook_ops *reg, 601 unsigned int hookcount) 602 { 603 unsigned int i; 604 605 for (i = 0; i < hookcount; i++) 606 nf_unregister_net_hook(net, ®[i]); 607 } 608 EXPORT_SYMBOL(nf_unregister_net_hooks); 609 610 /* Returns 1 if okfn() needs to be executed by the caller, 611 * -EPERM for NF_DROP, 0 otherwise. Caller must hold rcu_read_lock. */ 612 int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state, 613 const struct nf_hook_entries *e, unsigned int s) 614 { 615 unsigned int verdict; 616 int ret; 617 618 for (; s < e->num_hook_entries; s++) { 619 verdict = nf_hook_entry_hookfn(&e->hooks[s], skb, state); 620 switch (verdict & NF_VERDICT_MASK) { 621 case NF_ACCEPT: 622 break; 623 case NF_DROP: 624 kfree_skb(skb); 625 ret = NF_DROP_GETERR(verdict); 626 if (ret == 0) 627 ret = -EPERM; 628 return ret; 629 case NF_QUEUE: 630 ret = nf_queue(skb, state, s, verdict); 631 if (ret == 1) 632 continue; 633 return ret; 634 default: 635 /* Implicit handling for NF_STOLEN, as well as any other 636 * non conventional verdicts. 637 */ 638 return 0; 639 } 640 } 641 642 return 1; 643 } 644 EXPORT_SYMBOL(nf_hook_slow); 645 646 void nf_hook_slow_list(struct list_head *head, struct nf_hook_state *state, 647 const struct nf_hook_entries *e) 648 { 649 struct sk_buff *skb, *next; 650 struct list_head sublist; 651 int ret; 652 653 INIT_LIST_HEAD(&sublist); 654 655 list_for_each_entry_safe(skb, next, head, list) { 656 skb_list_del_init(skb); 657 ret = nf_hook_slow(skb, state, e, 0); 658 if (ret == 1) 659 list_add_tail(&skb->list, &sublist); 660 } 661 /* Put passed packets back on main list */ 662 list_splice(&sublist, head); 663 } 664 EXPORT_SYMBOL(nf_hook_slow_list); 665 666 /* This needs to be compiled in any case to avoid dependencies between the 667 * nfnetlink_queue code and nf_conntrack. 668 */ 669 struct nfnl_ct_hook __rcu *nfnl_ct_hook __read_mostly; 670 EXPORT_SYMBOL_GPL(nfnl_ct_hook); 671 672 struct nf_ct_hook __rcu *nf_ct_hook __read_mostly; 673 EXPORT_SYMBOL_GPL(nf_ct_hook); 674 675 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 676 /* This does not belong here, but locally generated errors need it if connection 677 tracking in use: without this, connection may not be in hash table, and hence 678 manufactured ICMP or RST packets will not be associated with it. */ 679 void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) 680 __rcu __read_mostly; 681 EXPORT_SYMBOL(ip_ct_attach); 682 683 struct nf_nat_hook __rcu *nf_nat_hook __read_mostly; 684 EXPORT_SYMBOL_GPL(nf_nat_hook); 685 686 void nf_ct_attach(struct sk_buff *new, const struct sk_buff *skb) 687 { 688 void (*attach)(struct sk_buff *, const struct sk_buff *); 689 690 if (skb->_nfct) { 691 rcu_read_lock(); 692 attach = rcu_dereference(ip_ct_attach); 693 if (attach) 694 attach(new, skb); 695 rcu_read_unlock(); 696 } 697 } 698 EXPORT_SYMBOL(nf_ct_attach); 699 700 void nf_conntrack_destroy(struct nf_conntrack *nfct) 701 { 702 struct nf_ct_hook *ct_hook; 703 704 rcu_read_lock(); 705 ct_hook = rcu_dereference(nf_ct_hook); 706 BUG_ON(ct_hook == NULL); 707 ct_hook->destroy(nfct); 708 rcu_read_unlock(); 709 } 710 EXPORT_SYMBOL(nf_conntrack_destroy); 711 712 bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple, 713 const struct sk_buff *skb) 714 { 715 struct nf_ct_hook *ct_hook; 716 bool ret = false; 717 718 rcu_read_lock(); 719 ct_hook = rcu_dereference(nf_ct_hook); 720 if (ct_hook) 721 ret = ct_hook->get_tuple_skb(dst_tuple, skb); 722 rcu_read_unlock(); 723 return ret; 724 } 725 EXPORT_SYMBOL(nf_ct_get_tuple_skb); 726 727 /* Built-in default zone used e.g. by modules. */ 728 const struct nf_conntrack_zone nf_ct_zone_dflt = { 729 .id = NF_CT_DEFAULT_ZONE_ID, 730 .dir = NF_CT_DEFAULT_ZONE_DIR, 731 }; 732 EXPORT_SYMBOL_GPL(nf_ct_zone_dflt); 733 #endif /* CONFIG_NF_CONNTRACK */ 734 735 static void __net_init 736 __netfilter_net_init(struct nf_hook_entries __rcu **e, int max) 737 { 738 int h; 739 740 for (h = 0; h < max; h++) 741 RCU_INIT_POINTER(e[h], NULL); 742 } 743 744 static int __net_init netfilter_net_init(struct net *net) 745 { 746 __netfilter_net_init(net->nf.hooks_ipv4, ARRAY_SIZE(net->nf.hooks_ipv4)); 747 __netfilter_net_init(net->nf.hooks_ipv6, ARRAY_SIZE(net->nf.hooks_ipv6)); 748 #ifdef CONFIG_NETFILTER_FAMILY_ARP 749 __netfilter_net_init(net->nf.hooks_arp, ARRAY_SIZE(net->nf.hooks_arp)); 750 #endif 751 #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE 752 __netfilter_net_init(net->nf.hooks_bridge, ARRAY_SIZE(net->nf.hooks_bridge)); 753 #endif 754 #if IS_ENABLED(CONFIG_DECNET) 755 __netfilter_net_init(net->nf.hooks_decnet, ARRAY_SIZE(net->nf.hooks_decnet)); 756 #endif 757 758 #ifdef CONFIG_PROC_FS 759 net->nf.proc_netfilter = proc_net_mkdir(net, "netfilter", 760 net->proc_net); 761 if (!net->nf.proc_netfilter) { 762 if (!net_eq(net, &init_net)) 763 pr_err("cannot create netfilter proc entry"); 764 765 return -ENOMEM; 766 } 767 #endif 768 769 return 0; 770 } 771 772 static void __net_exit netfilter_net_exit(struct net *net) 773 { 774 remove_proc_entry("netfilter", net->proc_net); 775 } 776 777 static struct pernet_operations netfilter_net_ops = { 778 .init = netfilter_net_init, 779 .exit = netfilter_net_exit, 780 }; 781 782 int __init netfilter_init(void) 783 { 784 int ret; 785 786 ret = register_pernet_subsys(&netfilter_net_ops); 787 if (ret < 0) 788 goto err; 789 790 ret = netfilter_log_init(); 791 if (ret < 0) 792 goto err_pernet; 793 794 return 0; 795 err_pernet: 796 unregister_pernet_subsys(&netfilter_net_ops); 797 err: 798 return ret; 799 } 800