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 WARN_ON_ONCE(1); 321 return NULL; 322 } 323 324 static int nf_ingress_check(struct net *net, const struct nf_hook_ops *reg, 325 int hooknum) 326 { 327 #ifndef CONFIG_NETFILTER_INGRESS 328 if (reg->hooknum == hooknum) 329 return -EOPNOTSUPP; 330 #endif 331 if (reg->hooknum != hooknum || 332 !reg->dev || dev_net(reg->dev) != net) 333 return -EINVAL; 334 335 return 0; 336 } 337 338 static inline bool nf_ingress_hook(const struct nf_hook_ops *reg, int pf) 339 { 340 if ((pf == NFPROTO_NETDEV && reg->hooknum == NF_NETDEV_INGRESS) || 341 (pf == NFPROTO_INET && reg->hooknum == NF_INET_INGRESS)) 342 return true; 343 344 return false; 345 } 346 347 static void nf_static_key_inc(const struct nf_hook_ops *reg, int pf) 348 { 349 #ifdef CONFIG_JUMP_LABEL 350 int hooknum; 351 352 if (pf == NFPROTO_INET && reg->hooknum == NF_INET_INGRESS) { 353 pf = NFPROTO_NETDEV; 354 hooknum = NF_NETDEV_INGRESS; 355 } else { 356 hooknum = reg->hooknum; 357 } 358 static_key_slow_inc(&nf_hooks_needed[pf][hooknum]); 359 #endif 360 } 361 362 static void nf_static_key_dec(const struct nf_hook_ops *reg, int pf) 363 { 364 #ifdef CONFIG_JUMP_LABEL 365 int hooknum; 366 367 if (pf == NFPROTO_INET && reg->hooknum == NF_INET_INGRESS) { 368 pf = NFPROTO_NETDEV; 369 hooknum = NF_NETDEV_INGRESS; 370 } else { 371 hooknum = reg->hooknum; 372 } 373 static_key_slow_dec(&nf_hooks_needed[pf][hooknum]); 374 #endif 375 } 376 377 static int __nf_register_net_hook(struct net *net, int pf, 378 const struct nf_hook_ops *reg) 379 { 380 struct nf_hook_entries *p, *new_hooks; 381 struct nf_hook_entries __rcu **pp; 382 int err; 383 384 switch (pf) { 385 case NFPROTO_NETDEV: 386 err = nf_ingress_check(net, reg, NF_NETDEV_INGRESS); 387 if (err < 0) 388 return err; 389 break; 390 case NFPROTO_INET: 391 if (reg->hooknum != NF_INET_INGRESS) 392 break; 393 394 err = nf_ingress_check(net, reg, NF_INET_INGRESS); 395 if (err < 0) 396 return err; 397 break; 398 } 399 400 pp = nf_hook_entry_head(net, pf, reg->hooknum, reg->dev); 401 if (!pp) 402 return -EINVAL; 403 404 mutex_lock(&nf_hook_mutex); 405 406 p = nf_entry_dereference(*pp); 407 new_hooks = nf_hook_entries_grow(p, reg); 408 409 if (!IS_ERR(new_hooks)) 410 rcu_assign_pointer(*pp, new_hooks); 411 412 mutex_unlock(&nf_hook_mutex); 413 if (IS_ERR(new_hooks)) 414 return PTR_ERR(new_hooks); 415 416 hooks_validate(new_hooks); 417 #ifdef CONFIG_NETFILTER_INGRESS 418 if (nf_ingress_hook(reg, pf)) 419 net_inc_ingress_queue(); 420 #endif 421 nf_static_key_inc(reg, pf); 422 423 BUG_ON(p == new_hooks); 424 nf_hook_entries_free(p); 425 return 0; 426 } 427 428 /* 429 * nf_remove_net_hook - remove a hook from blob 430 * 431 * @oldp: current address of hook blob 432 * @unreg: hook to unregister 433 * 434 * This cannot fail, hook unregistration must always succeed. 435 * Therefore replace the to-be-removed hook with a dummy hook. 436 */ 437 static bool nf_remove_net_hook(struct nf_hook_entries *old, 438 const struct nf_hook_ops *unreg) 439 { 440 struct nf_hook_ops **orig_ops; 441 unsigned int i; 442 443 orig_ops = nf_hook_entries_get_hook_ops(old); 444 for (i = 0; i < old->num_hook_entries; i++) { 445 if (orig_ops[i] != unreg) 446 continue; 447 WRITE_ONCE(old->hooks[i].hook, accept_all); 448 WRITE_ONCE(orig_ops[i], (void *)&dummy_ops); 449 return true; 450 } 451 452 return false; 453 } 454 455 static void __nf_unregister_net_hook(struct net *net, int pf, 456 const struct nf_hook_ops *reg) 457 { 458 struct nf_hook_entries __rcu **pp; 459 struct nf_hook_entries *p; 460 461 pp = nf_hook_entry_head(net, pf, reg->hooknum, reg->dev); 462 if (!pp) 463 return; 464 465 mutex_lock(&nf_hook_mutex); 466 467 p = nf_entry_dereference(*pp); 468 if (WARN_ON_ONCE(!p)) { 469 mutex_unlock(&nf_hook_mutex); 470 return; 471 } 472 473 if (nf_remove_net_hook(p, reg)) { 474 #ifdef CONFIG_NETFILTER_INGRESS 475 if (nf_ingress_hook(reg, pf)) 476 net_dec_ingress_queue(); 477 #endif 478 nf_static_key_dec(reg, pf); 479 } else { 480 WARN_ONCE(1, "hook not found, pf %d num %d", pf, reg->hooknum); 481 } 482 483 p = __nf_hook_entries_try_shrink(p, pp); 484 mutex_unlock(&nf_hook_mutex); 485 if (!p) 486 return; 487 488 nf_queue_nf_hook_drop(net); 489 nf_hook_entries_free(p); 490 } 491 492 void nf_unregister_net_hook(struct net *net, const struct nf_hook_ops *reg) 493 { 494 if (reg->pf == NFPROTO_INET) { 495 if (reg->hooknum == NF_INET_INGRESS) { 496 __nf_unregister_net_hook(net, NFPROTO_INET, reg); 497 } else { 498 __nf_unregister_net_hook(net, NFPROTO_IPV4, reg); 499 __nf_unregister_net_hook(net, NFPROTO_IPV6, reg); 500 } 501 } else { 502 __nf_unregister_net_hook(net, reg->pf, reg); 503 } 504 } 505 EXPORT_SYMBOL(nf_unregister_net_hook); 506 507 void nf_hook_entries_delete_raw(struct nf_hook_entries __rcu **pp, 508 const struct nf_hook_ops *reg) 509 { 510 struct nf_hook_entries *p; 511 512 p = rcu_dereference_raw(*pp); 513 if (nf_remove_net_hook(p, reg)) { 514 p = __nf_hook_entries_try_shrink(p, pp); 515 nf_hook_entries_free(p); 516 } 517 } 518 EXPORT_SYMBOL_GPL(nf_hook_entries_delete_raw); 519 520 int nf_register_net_hook(struct net *net, const struct nf_hook_ops *reg) 521 { 522 int err; 523 524 if (reg->pf == NFPROTO_INET) { 525 if (reg->hooknum == NF_INET_INGRESS) { 526 err = __nf_register_net_hook(net, NFPROTO_INET, reg); 527 if (err < 0) 528 return err; 529 } else { 530 err = __nf_register_net_hook(net, NFPROTO_IPV4, reg); 531 if (err < 0) 532 return err; 533 534 err = __nf_register_net_hook(net, NFPROTO_IPV6, reg); 535 if (err < 0) { 536 __nf_unregister_net_hook(net, NFPROTO_IPV4, reg); 537 return err; 538 } 539 } 540 } else { 541 err = __nf_register_net_hook(net, reg->pf, reg); 542 if (err < 0) 543 return err; 544 } 545 546 return 0; 547 } 548 EXPORT_SYMBOL(nf_register_net_hook); 549 550 int nf_register_net_hooks(struct net *net, const struct nf_hook_ops *reg, 551 unsigned int n) 552 { 553 unsigned int i; 554 int err = 0; 555 556 for (i = 0; i < n; i++) { 557 err = nf_register_net_hook(net, ®[i]); 558 if (err) 559 goto err; 560 } 561 return err; 562 563 err: 564 if (i > 0) 565 nf_unregister_net_hooks(net, reg, i); 566 return err; 567 } 568 EXPORT_SYMBOL(nf_register_net_hooks); 569 570 void nf_unregister_net_hooks(struct net *net, const struct nf_hook_ops *reg, 571 unsigned int hookcount) 572 { 573 unsigned int i; 574 575 for (i = 0; i < hookcount; i++) 576 nf_unregister_net_hook(net, ®[i]); 577 } 578 EXPORT_SYMBOL(nf_unregister_net_hooks); 579 580 /* Returns 1 if okfn() needs to be executed by the caller, 581 * -EPERM for NF_DROP, 0 otherwise. Caller must hold rcu_read_lock. */ 582 int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state, 583 const struct nf_hook_entries *e, unsigned int s) 584 { 585 unsigned int verdict; 586 int ret; 587 588 for (; s < e->num_hook_entries; s++) { 589 verdict = nf_hook_entry_hookfn(&e->hooks[s], skb, state); 590 switch (verdict & NF_VERDICT_MASK) { 591 case NF_ACCEPT: 592 break; 593 case NF_DROP: 594 kfree_skb(skb); 595 ret = NF_DROP_GETERR(verdict); 596 if (ret == 0) 597 ret = -EPERM; 598 return ret; 599 case NF_QUEUE: 600 ret = nf_queue(skb, state, s, verdict); 601 if (ret == 1) 602 continue; 603 return ret; 604 default: 605 /* Implicit handling for NF_STOLEN, as well as any other 606 * non conventional verdicts. 607 */ 608 return 0; 609 } 610 } 611 612 return 1; 613 } 614 EXPORT_SYMBOL(nf_hook_slow); 615 616 void nf_hook_slow_list(struct list_head *head, struct nf_hook_state *state, 617 const struct nf_hook_entries *e) 618 { 619 struct sk_buff *skb, *next; 620 struct list_head sublist; 621 int ret; 622 623 INIT_LIST_HEAD(&sublist); 624 625 list_for_each_entry_safe(skb, next, head, list) { 626 skb_list_del_init(skb); 627 ret = nf_hook_slow(skb, state, e, 0); 628 if (ret == 1) 629 list_add_tail(&skb->list, &sublist); 630 } 631 /* Put passed packets back on main list */ 632 list_splice(&sublist, head); 633 } 634 EXPORT_SYMBOL(nf_hook_slow_list); 635 636 /* This needs to be compiled in any case to avoid dependencies between the 637 * nfnetlink_queue code and nf_conntrack. 638 */ 639 struct nfnl_ct_hook __rcu *nfnl_ct_hook __read_mostly; 640 EXPORT_SYMBOL_GPL(nfnl_ct_hook); 641 642 struct nf_ct_hook __rcu *nf_ct_hook __read_mostly; 643 EXPORT_SYMBOL_GPL(nf_ct_hook); 644 645 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 646 /* This does not belong here, but locally generated errors need it if connection 647 tracking in use: without this, connection may not be in hash table, and hence 648 manufactured ICMP or RST packets will not be associated with it. */ 649 void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) 650 __rcu __read_mostly; 651 EXPORT_SYMBOL(ip_ct_attach); 652 653 struct nf_nat_hook __rcu *nf_nat_hook __read_mostly; 654 EXPORT_SYMBOL_GPL(nf_nat_hook); 655 656 void nf_ct_attach(struct sk_buff *new, const struct sk_buff *skb) 657 { 658 void (*attach)(struct sk_buff *, const struct sk_buff *); 659 660 if (skb->_nfct) { 661 rcu_read_lock(); 662 attach = rcu_dereference(ip_ct_attach); 663 if (attach) 664 attach(new, skb); 665 rcu_read_unlock(); 666 } 667 } 668 EXPORT_SYMBOL(nf_ct_attach); 669 670 void nf_conntrack_destroy(struct nf_conntrack *nfct) 671 { 672 struct nf_ct_hook *ct_hook; 673 674 rcu_read_lock(); 675 ct_hook = rcu_dereference(nf_ct_hook); 676 BUG_ON(ct_hook == NULL); 677 ct_hook->destroy(nfct); 678 rcu_read_unlock(); 679 } 680 EXPORT_SYMBOL(nf_conntrack_destroy); 681 682 bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple, 683 const struct sk_buff *skb) 684 { 685 struct nf_ct_hook *ct_hook; 686 bool ret = false; 687 688 rcu_read_lock(); 689 ct_hook = rcu_dereference(nf_ct_hook); 690 if (ct_hook) 691 ret = ct_hook->get_tuple_skb(dst_tuple, skb); 692 rcu_read_unlock(); 693 return ret; 694 } 695 EXPORT_SYMBOL(nf_ct_get_tuple_skb); 696 697 /* Built-in default zone used e.g. by modules. */ 698 const struct nf_conntrack_zone nf_ct_zone_dflt = { 699 .id = NF_CT_DEFAULT_ZONE_ID, 700 .dir = NF_CT_DEFAULT_ZONE_DIR, 701 }; 702 EXPORT_SYMBOL_GPL(nf_ct_zone_dflt); 703 #endif /* CONFIG_NF_CONNTRACK */ 704 705 static void __net_init 706 __netfilter_net_init(struct nf_hook_entries __rcu **e, int max) 707 { 708 int h; 709 710 for (h = 0; h < max; h++) 711 RCU_INIT_POINTER(e[h], NULL); 712 } 713 714 static int __net_init netfilter_net_init(struct net *net) 715 { 716 __netfilter_net_init(net->nf.hooks_ipv4, ARRAY_SIZE(net->nf.hooks_ipv4)); 717 __netfilter_net_init(net->nf.hooks_ipv6, ARRAY_SIZE(net->nf.hooks_ipv6)); 718 #ifdef CONFIG_NETFILTER_FAMILY_ARP 719 __netfilter_net_init(net->nf.hooks_arp, ARRAY_SIZE(net->nf.hooks_arp)); 720 #endif 721 #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE 722 __netfilter_net_init(net->nf.hooks_bridge, ARRAY_SIZE(net->nf.hooks_bridge)); 723 #endif 724 #if IS_ENABLED(CONFIG_DECNET) 725 __netfilter_net_init(net->nf.hooks_decnet, ARRAY_SIZE(net->nf.hooks_decnet)); 726 #endif 727 728 #ifdef CONFIG_PROC_FS 729 net->nf.proc_netfilter = proc_net_mkdir(net, "netfilter", 730 net->proc_net); 731 if (!net->nf.proc_netfilter) { 732 if (!net_eq(net, &init_net)) 733 pr_err("cannot create netfilter proc entry"); 734 735 return -ENOMEM; 736 } 737 #endif 738 739 return 0; 740 } 741 742 static void __net_exit netfilter_net_exit(struct net *net) 743 { 744 remove_proc_entry("netfilter", net->proc_net); 745 } 746 747 static struct pernet_operations netfilter_net_ops = { 748 .init = netfilter_net_init, 749 .exit = netfilter_net_exit, 750 }; 751 752 int __init netfilter_init(void) 753 { 754 int ret; 755 756 ret = register_pernet_subsys(&netfilter_net_ops); 757 if (ret < 0) 758 goto err; 759 760 ret = netfilter_log_init(); 761 if (ret < 0) 762 goto err_pernet; 763 764 return 0; 765 err_pernet: 766 unregister_pernet_subsys(&netfilter_net_ops); 767 err: 768 return ret; 769 } 770