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 nf_ingress_hook(const struct nf_hook_ops *reg, int pf) 345 { 346 if ((pf == NFPROTO_NETDEV && reg->hooknum == NF_NETDEV_INGRESS) || 347 (pf == NFPROTO_INET && reg->hooknum == NF_INET_INGRESS)) 348 return true; 349 350 return false; 351 } 352 353 static inline bool nf_egress_hook(const struct nf_hook_ops *reg, int pf) 354 { 355 return pf == NFPROTO_NETDEV && reg->hooknum == NF_NETDEV_EGRESS; 356 } 357 358 static void nf_static_key_inc(const struct nf_hook_ops *reg, int pf) 359 { 360 #ifdef CONFIG_JUMP_LABEL 361 int hooknum; 362 363 if (pf == NFPROTO_INET && reg->hooknum == NF_INET_INGRESS) { 364 pf = NFPROTO_NETDEV; 365 hooknum = NF_NETDEV_INGRESS; 366 } else { 367 hooknum = reg->hooknum; 368 } 369 static_key_slow_inc(&nf_hooks_needed[pf][hooknum]); 370 #endif 371 } 372 373 static void nf_static_key_dec(const struct nf_hook_ops *reg, int pf) 374 { 375 #ifdef CONFIG_JUMP_LABEL 376 int hooknum; 377 378 if (pf == NFPROTO_INET && reg->hooknum == NF_INET_INGRESS) { 379 pf = NFPROTO_NETDEV; 380 hooknum = NF_NETDEV_INGRESS; 381 } else { 382 hooknum = reg->hooknum; 383 } 384 static_key_slow_dec(&nf_hooks_needed[pf][hooknum]); 385 #endif 386 } 387 388 static int __nf_register_net_hook(struct net *net, int pf, 389 const struct nf_hook_ops *reg) 390 { 391 struct nf_hook_entries *p, *new_hooks; 392 struct nf_hook_entries __rcu **pp; 393 int err; 394 395 switch (pf) { 396 case NFPROTO_NETDEV: 397 #ifndef CONFIG_NETFILTER_INGRESS 398 if (reg->hooknum == NF_NETDEV_INGRESS) 399 return -EOPNOTSUPP; 400 #endif 401 #ifndef CONFIG_NETFILTER_EGRESS 402 if (reg->hooknum == NF_NETDEV_EGRESS) 403 return -EOPNOTSUPP; 404 #endif 405 if ((reg->hooknum != NF_NETDEV_INGRESS && 406 reg->hooknum != NF_NETDEV_EGRESS) || 407 !reg->dev || dev_net(reg->dev) != net) 408 return -EINVAL; 409 break; 410 case NFPROTO_INET: 411 if (reg->hooknum != NF_INET_INGRESS) 412 break; 413 414 err = nf_ingress_check(net, reg, NF_INET_INGRESS); 415 if (err < 0) 416 return err; 417 break; 418 } 419 420 pp = nf_hook_entry_head(net, pf, reg->hooknum, reg->dev); 421 if (!pp) 422 return -EINVAL; 423 424 mutex_lock(&nf_hook_mutex); 425 426 p = nf_entry_dereference(*pp); 427 new_hooks = nf_hook_entries_grow(p, reg); 428 429 if (!IS_ERR(new_hooks)) 430 rcu_assign_pointer(*pp, new_hooks); 431 432 mutex_unlock(&nf_hook_mutex); 433 if (IS_ERR(new_hooks)) 434 return PTR_ERR(new_hooks); 435 436 hooks_validate(new_hooks); 437 #ifdef CONFIG_NETFILTER_INGRESS 438 if (nf_ingress_hook(reg, pf)) 439 net_inc_ingress_queue(); 440 #endif 441 #ifdef CONFIG_NETFILTER_EGRESS 442 if (nf_egress_hook(reg, pf)) 443 net_inc_egress_queue(); 444 #endif 445 nf_static_key_inc(reg, pf); 446 447 BUG_ON(p == new_hooks); 448 nf_hook_entries_free(p); 449 return 0; 450 } 451 452 /* 453 * nf_remove_net_hook - remove a hook from blob 454 * 455 * @oldp: current address of hook blob 456 * @unreg: hook to unregister 457 * 458 * This cannot fail, hook unregistration must always succeed. 459 * Therefore replace the to-be-removed hook with a dummy hook. 460 */ 461 static bool nf_remove_net_hook(struct nf_hook_entries *old, 462 const struct nf_hook_ops *unreg) 463 { 464 struct nf_hook_ops **orig_ops; 465 unsigned int i; 466 467 orig_ops = nf_hook_entries_get_hook_ops(old); 468 for (i = 0; i < old->num_hook_entries; i++) { 469 if (orig_ops[i] != unreg) 470 continue; 471 WRITE_ONCE(old->hooks[i].hook, accept_all); 472 WRITE_ONCE(orig_ops[i], (void *)&dummy_ops); 473 return true; 474 } 475 476 return false; 477 } 478 479 static void __nf_unregister_net_hook(struct net *net, int pf, 480 const struct nf_hook_ops *reg) 481 { 482 struct nf_hook_entries __rcu **pp; 483 struct nf_hook_entries *p; 484 485 pp = nf_hook_entry_head(net, pf, reg->hooknum, reg->dev); 486 if (!pp) 487 return; 488 489 mutex_lock(&nf_hook_mutex); 490 491 p = nf_entry_dereference(*pp); 492 if (WARN_ON_ONCE(!p)) { 493 mutex_unlock(&nf_hook_mutex); 494 return; 495 } 496 497 if (nf_remove_net_hook(p, reg)) { 498 #ifdef CONFIG_NETFILTER_INGRESS 499 if (nf_ingress_hook(reg, pf)) 500 net_dec_ingress_queue(); 501 #endif 502 #ifdef CONFIG_NETFILTER_EGRESS 503 if (nf_egress_hook(reg, pf)) 504 net_dec_egress_queue(); 505 #endif 506 nf_static_key_dec(reg, pf); 507 } else { 508 WARN_ONCE(1, "hook not found, pf %d num %d", pf, reg->hooknum); 509 } 510 511 p = __nf_hook_entries_try_shrink(p, pp); 512 mutex_unlock(&nf_hook_mutex); 513 if (!p) 514 return; 515 516 nf_queue_nf_hook_drop(net); 517 nf_hook_entries_free(p); 518 } 519 520 void nf_unregister_net_hook(struct net *net, const struct nf_hook_ops *reg) 521 { 522 if (reg->pf == NFPROTO_INET) { 523 if (reg->hooknum == NF_INET_INGRESS) { 524 __nf_unregister_net_hook(net, NFPROTO_INET, reg); 525 } else { 526 __nf_unregister_net_hook(net, NFPROTO_IPV4, reg); 527 __nf_unregister_net_hook(net, NFPROTO_IPV6, reg); 528 } 529 } else { 530 __nf_unregister_net_hook(net, reg->pf, reg); 531 } 532 } 533 EXPORT_SYMBOL(nf_unregister_net_hook); 534 535 void nf_hook_entries_delete_raw(struct nf_hook_entries __rcu **pp, 536 const struct nf_hook_ops *reg) 537 { 538 struct nf_hook_entries *p; 539 540 p = rcu_dereference_raw(*pp); 541 if (nf_remove_net_hook(p, reg)) { 542 p = __nf_hook_entries_try_shrink(p, pp); 543 nf_hook_entries_free(p); 544 } 545 } 546 EXPORT_SYMBOL_GPL(nf_hook_entries_delete_raw); 547 548 int nf_register_net_hook(struct net *net, const struct nf_hook_ops *reg) 549 { 550 int err; 551 552 if (reg->pf == NFPROTO_INET) { 553 if (reg->hooknum == NF_INET_INGRESS) { 554 err = __nf_register_net_hook(net, NFPROTO_INET, reg); 555 if (err < 0) 556 return err; 557 } else { 558 err = __nf_register_net_hook(net, NFPROTO_IPV4, reg); 559 if (err < 0) 560 return err; 561 562 err = __nf_register_net_hook(net, NFPROTO_IPV6, reg); 563 if (err < 0) { 564 __nf_unregister_net_hook(net, NFPROTO_IPV4, reg); 565 return err; 566 } 567 } 568 } else { 569 err = __nf_register_net_hook(net, reg->pf, reg); 570 if (err < 0) 571 return err; 572 } 573 574 return 0; 575 } 576 EXPORT_SYMBOL(nf_register_net_hook); 577 578 int nf_register_net_hooks(struct net *net, const struct nf_hook_ops *reg, 579 unsigned int n) 580 { 581 unsigned int i; 582 int err = 0; 583 584 for (i = 0; i < n; i++) { 585 err = nf_register_net_hook(net, ®[i]); 586 if (err) 587 goto err; 588 } 589 return err; 590 591 err: 592 if (i > 0) 593 nf_unregister_net_hooks(net, reg, i); 594 return err; 595 } 596 EXPORT_SYMBOL(nf_register_net_hooks); 597 598 void nf_unregister_net_hooks(struct net *net, const struct nf_hook_ops *reg, 599 unsigned int hookcount) 600 { 601 unsigned int i; 602 603 for (i = 0; i < hookcount; i++) 604 nf_unregister_net_hook(net, ®[i]); 605 } 606 EXPORT_SYMBOL(nf_unregister_net_hooks); 607 608 /* Returns 1 if okfn() needs to be executed by the caller, 609 * -EPERM for NF_DROP, 0 otherwise. Caller must hold rcu_read_lock. */ 610 int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state, 611 const struct nf_hook_entries *e, unsigned int s) 612 { 613 unsigned int verdict; 614 int ret; 615 616 for (; s < e->num_hook_entries; s++) { 617 verdict = nf_hook_entry_hookfn(&e->hooks[s], skb, state); 618 switch (verdict & NF_VERDICT_MASK) { 619 case NF_ACCEPT: 620 break; 621 case NF_DROP: 622 kfree_skb(skb); 623 ret = NF_DROP_GETERR(verdict); 624 if (ret == 0) 625 ret = -EPERM; 626 return ret; 627 case NF_QUEUE: 628 ret = nf_queue(skb, state, s, verdict); 629 if (ret == 1) 630 continue; 631 return ret; 632 default: 633 /* Implicit handling for NF_STOLEN, as well as any other 634 * non conventional verdicts. 635 */ 636 return 0; 637 } 638 } 639 640 return 1; 641 } 642 EXPORT_SYMBOL(nf_hook_slow); 643 644 void nf_hook_slow_list(struct list_head *head, struct nf_hook_state *state, 645 const struct nf_hook_entries *e) 646 { 647 struct sk_buff *skb, *next; 648 struct list_head sublist; 649 int ret; 650 651 INIT_LIST_HEAD(&sublist); 652 653 list_for_each_entry_safe(skb, next, head, list) { 654 skb_list_del_init(skb); 655 ret = nf_hook_slow(skb, state, e, 0); 656 if (ret == 1) 657 list_add_tail(&skb->list, &sublist); 658 } 659 /* Put passed packets back on main list */ 660 list_splice(&sublist, head); 661 } 662 EXPORT_SYMBOL(nf_hook_slow_list); 663 664 /* This needs to be compiled in any case to avoid dependencies between the 665 * nfnetlink_queue code and nf_conntrack. 666 */ 667 struct nfnl_ct_hook __rcu *nfnl_ct_hook __read_mostly; 668 EXPORT_SYMBOL_GPL(nfnl_ct_hook); 669 670 struct nf_ct_hook __rcu *nf_ct_hook __read_mostly; 671 EXPORT_SYMBOL_GPL(nf_ct_hook); 672 673 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 674 /* This does not belong here, but locally generated errors need it if connection 675 tracking in use: without this, connection may not be in hash table, and hence 676 manufactured ICMP or RST packets will not be associated with it. */ 677 void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) 678 __rcu __read_mostly; 679 EXPORT_SYMBOL(ip_ct_attach); 680 681 struct nf_nat_hook __rcu *nf_nat_hook __read_mostly; 682 EXPORT_SYMBOL_GPL(nf_nat_hook); 683 684 void nf_ct_attach(struct sk_buff *new, const struct sk_buff *skb) 685 { 686 void (*attach)(struct sk_buff *, const struct sk_buff *); 687 688 if (skb->_nfct) { 689 rcu_read_lock(); 690 attach = rcu_dereference(ip_ct_attach); 691 if (attach) 692 attach(new, skb); 693 rcu_read_unlock(); 694 } 695 } 696 EXPORT_SYMBOL(nf_ct_attach); 697 698 void nf_conntrack_destroy(struct nf_conntrack *nfct) 699 { 700 struct nf_ct_hook *ct_hook; 701 702 rcu_read_lock(); 703 ct_hook = rcu_dereference(nf_ct_hook); 704 BUG_ON(ct_hook == NULL); 705 ct_hook->destroy(nfct); 706 rcu_read_unlock(); 707 } 708 EXPORT_SYMBOL(nf_conntrack_destroy); 709 710 bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple, 711 const struct sk_buff *skb) 712 { 713 struct nf_ct_hook *ct_hook; 714 bool ret = false; 715 716 rcu_read_lock(); 717 ct_hook = rcu_dereference(nf_ct_hook); 718 if (ct_hook) 719 ret = ct_hook->get_tuple_skb(dst_tuple, skb); 720 rcu_read_unlock(); 721 return ret; 722 } 723 EXPORT_SYMBOL(nf_ct_get_tuple_skb); 724 725 /* Built-in default zone used e.g. by modules. */ 726 const struct nf_conntrack_zone nf_ct_zone_dflt = { 727 .id = NF_CT_DEFAULT_ZONE_ID, 728 .dir = NF_CT_DEFAULT_ZONE_DIR, 729 }; 730 EXPORT_SYMBOL_GPL(nf_ct_zone_dflt); 731 #endif /* CONFIG_NF_CONNTRACK */ 732 733 static void __net_init 734 __netfilter_net_init(struct nf_hook_entries __rcu **e, int max) 735 { 736 int h; 737 738 for (h = 0; h < max; h++) 739 RCU_INIT_POINTER(e[h], NULL); 740 } 741 742 static int __net_init netfilter_net_init(struct net *net) 743 { 744 __netfilter_net_init(net->nf.hooks_ipv4, ARRAY_SIZE(net->nf.hooks_ipv4)); 745 __netfilter_net_init(net->nf.hooks_ipv6, ARRAY_SIZE(net->nf.hooks_ipv6)); 746 #ifdef CONFIG_NETFILTER_FAMILY_ARP 747 __netfilter_net_init(net->nf.hooks_arp, ARRAY_SIZE(net->nf.hooks_arp)); 748 #endif 749 #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE 750 __netfilter_net_init(net->nf.hooks_bridge, ARRAY_SIZE(net->nf.hooks_bridge)); 751 #endif 752 #if IS_ENABLED(CONFIG_DECNET) 753 __netfilter_net_init(net->nf.hooks_decnet, ARRAY_SIZE(net->nf.hooks_decnet)); 754 #endif 755 756 #ifdef CONFIG_PROC_FS 757 net->nf.proc_netfilter = proc_net_mkdir(net, "netfilter", 758 net->proc_net); 759 if (!net->nf.proc_netfilter) { 760 if (!net_eq(net, &init_net)) 761 pr_err("cannot create netfilter proc entry"); 762 763 return -ENOMEM; 764 } 765 #endif 766 767 return 0; 768 } 769 770 static void __net_exit netfilter_net_exit(struct net *net) 771 { 772 remove_proc_entry("netfilter", net->proc_net); 773 } 774 775 static struct pernet_operations netfilter_net_ops = { 776 .init = netfilter_net_init, 777 .exit = netfilter_net_exit, 778 }; 779 780 int __init netfilter_init(void) 781 { 782 int ret; 783 784 ret = register_pernet_subsys(&netfilter_net_ops); 785 if (ret < 0) 786 goto err; 787 788 ret = netfilter_log_init(); 789 if (ret < 0) 790 goto err_pernet; 791 792 return 0; 793 err_pernet: 794 unregister_pernet_subsys(&netfilter_net_ops); 795 err: 796 return ret; 797 } 798