1 /* 2 * net/core/fib_rules.c Generic Routing Rules 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License as 6 * published by the Free Software Foundation, version 2. 7 * 8 * Authors: Thomas Graf <tgraf@suug.ch> 9 */ 10 11 #include <linux/types.h> 12 #include <linux/kernel.h> 13 #include <linux/slab.h> 14 #include <linux/list.h> 15 #include <linux/module.h> 16 #include <net/net_namespace.h> 17 #include <net/sock.h> 18 #include <net/fib_rules.h> 19 20 int fib_default_rule_add(struct fib_rules_ops *ops, 21 u32 pref, u32 table, u32 flags) 22 { 23 struct fib_rule *r; 24 25 r = kzalloc(ops->rule_size, GFP_KERNEL); 26 if (r == NULL) 27 return -ENOMEM; 28 29 atomic_set(&r->refcnt, 1); 30 r->action = FR_ACT_TO_TBL; 31 r->pref = pref; 32 r->table = table; 33 r->flags = flags; 34 r->fr_net = hold_net(ops->fro_net); 35 36 /* The lock is not required here, the list in unreacheable 37 * at the moment this function is called */ 38 list_add_tail(&r->list, &ops->rules_list); 39 return 0; 40 } 41 EXPORT_SYMBOL(fib_default_rule_add); 42 43 u32 fib_default_rule_pref(struct fib_rules_ops *ops) 44 { 45 struct list_head *pos; 46 struct fib_rule *rule; 47 48 if (!list_empty(&ops->rules_list)) { 49 pos = ops->rules_list.next; 50 if (pos->next != &ops->rules_list) { 51 rule = list_entry(pos->next, struct fib_rule, list); 52 if (rule->pref) 53 return rule->pref - 1; 54 } 55 } 56 57 return 0; 58 } 59 EXPORT_SYMBOL(fib_default_rule_pref); 60 61 static void notify_rule_change(int event, struct fib_rule *rule, 62 struct fib_rules_ops *ops, struct nlmsghdr *nlh, 63 u32 pid); 64 65 static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family) 66 { 67 struct fib_rules_ops *ops; 68 69 rcu_read_lock(); 70 list_for_each_entry_rcu(ops, &net->rules_ops, list) { 71 if (ops->family == family) { 72 if (!try_module_get(ops->owner)) 73 ops = NULL; 74 rcu_read_unlock(); 75 return ops; 76 } 77 } 78 rcu_read_unlock(); 79 80 return NULL; 81 } 82 83 static void rules_ops_put(struct fib_rules_ops *ops) 84 { 85 if (ops) 86 module_put(ops->owner); 87 } 88 89 static void flush_route_cache(struct fib_rules_ops *ops) 90 { 91 if (ops->flush_cache) 92 ops->flush_cache(ops); 93 } 94 95 static int __fib_rules_register(struct fib_rules_ops *ops) 96 { 97 int err = -EEXIST; 98 struct fib_rules_ops *o; 99 struct net *net; 100 101 net = ops->fro_net; 102 103 if (ops->rule_size < sizeof(struct fib_rule)) 104 return -EINVAL; 105 106 if (ops->match == NULL || ops->configure == NULL || 107 ops->compare == NULL || ops->fill == NULL || 108 ops->action == NULL) 109 return -EINVAL; 110 111 spin_lock(&net->rules_mod_lock); 112 list_for_each_entry(o, &net->rules_ops, list) 113 if (ops->family == o->family) 114 goto errout; 115 116 hold_net(net); 117 list_add_tail_rcu(&ops->list, &net->rules_ops); 118 err = 0; 119 errout: 120 spin_unlock(&net->rules_mod_lock); 121 122 return err; 123 } 124 125 struct fib_rules_ops * 126 fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net) 127 { 128 struct fib_rules_ops *ops; 129 int err; 130 131 ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL); 132 if (ops == NULL) 133 return ERR_PTR(-ENOMEM); 134 135 INIT_LIST_HEAD(&ops->rules_list); 136 ops->fro_net = net; 137 138 err = __fib_rules_register(ops); 139 if (err) { 140 kfree(ops); 141 ops = ERR_PTR(err); 142 } 143 144 return ops; 145 } 146 EXPORT_SYMBOL_GPL(fib_rules_register); 147 148 static void fib_rules_cleanup_ops(struct fib_rules_ops *ops) 149 { 150 struct fib_rule *rule, *tmp; 151 152 list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) { 153 list_del_rcu(&rule->list); 154 fib_rule_put(rule); 155 } 156 } 157 158 static void fib_rules_put_rcu(struct rcu_head *head) 159 { 160 struct fib_rules_ops *ops = container_of(head, struct fib_rules_ops, rcu); 161 struct net *net = ops->fro_net; 162 163 release_net(net); 164 kfree(ops); 165 } 166 167 void fib_rules_unregister(struct fib_rules_ops *ops) 168 { 169 struct net *net = ops->fro_net; 170 171 spin_lock(&net->rules_mod_lock); 172 list_del_rcu(&ops->list); 173 fib_rules_cleanup_ops(ops); 174 spin_unlock(&net->rules_mod_lock); 175 176 call_rcu(&ops->rcu, fib_rules_put_rcu); 177 } 178 EXPORT_SYMBOL_GPL(fib_rules_unregister); 179 180 static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops, 181 struct flowi *fl, int flags) 182 { 183 int ret = 0; 184 185 if (rule->iifindex && (rule->iifindex != fl->flowi_iif)) 186 goto out; 187 188 if (rule->oifindex && (rule->oifindex != fl->flowi_oif)) 189 goto out; 190 191 if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask) 192 goto out; 193 194 ret = ops->match(rule, fl, flags); 195 out: 196 return (rule->flags & FIB_RULE_INVERT) ? !ret : ret; 197 } 198 199 int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl, 200 int flags, struct fib_lookup_arg *arg) 201 { 202 struct fib_rule *rule; 203 int err; 204 205 rcu_read_lock(); 206 207 list_for_each_entry_rcu(rule, &ops->rules_list, list) { 208 jumped: 209 if (!fib_rule_match(rule, ops, fl, flags)) 210 continue; 211 212 if (rule->action == FR_ACT_GOTO) { 213 struct fib_rule *target; 214 215 target = rcu_dereference(rule->ctarget); 216 if (target == NULL) { 217 continue; 218 } else { 219 rule = target; 220 goto jumped; 221 } 222 } else if (rule->action == FR_ACT_NOP) 223 continue; 224 else 225 err = ops->action(rule, fl, flags, arg); 226 227 if (err != -EAGAIN) { 228 if ((arg->flags & FIB_LOOKUP_NOREF) || 229 likely(atomic_inc_not_zero(&rule->refcnt))) { 230 arg->rule = rule; 231 goto out; 232 } 233 break; 234 } 235 } 236 237 err = -ESRCH; 238 out: 239 rcu_read_unlock(); 240 241 return err; 242 } 243 EXPORT_SYMBOL_GPL(fib_rules_lookup); 244 245 static int validate_rulemsg(struct fib_rule_hdr *frh, struct nlattr **tb, 246 struct fib_rules_ops *ops) 247 { 248 int err = -EINVAL; 249 250 if (frh->src_len) 251 if (tb[FRA_SRC] == NULL || 252 frh->src_len > (ops->addr_size * 8) || 253 nla_len(tb[FRA_SRC]) != ops->addr_size) 254 goto errout; 255 256 if (frh->dst_len) 257 if (tb[FRA_DST] == NULL || 258 frh->dst_len > (ops->addr_size * 8) || 259 nla_len(tb[FRA_DST]) != ops->addr_size) 260 goto errout; 261 262 err = 0; 263 errout: 264 return err; 265 } 266 267 static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 268 { 269 struct net *net = sock_net(skb->sk); 270 struct fib_rule_hdr *frh = nlmsg_data(nlh); 271 struct fib_rules_ops *ops = NULL; 272 struct fib_rule *rule, *r, *last = NULL; 273 struct nlattr *tb[FRA_MAX+1]; 274 int err = -EINVAL, unresolved = 0; 275 276 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) 277 goto errout; 278 279 ops = lookup_rules_ops(net, frh->family); 280 if (ops == NULL) { 281 err = -EAFNOSUPPORT; 282 goto errout; 283 } 284 285 err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy); 286 if (err < 0) 287 goto errout; 288 289 err = validate_rulemsg(frh, tb, ops); 290 if (err < 0) 291 goto errout; 292 293 rule = kzalloc(ops->rule_size, GFP_KERNEL); 294 if (rule == NULL) { 295 err = -ENOMEM; 296 goto errout; 297 } 298 rule->fr_net = hold_net(net); 299 300 if (tb[FRA_PRIORITY]) 301 rule->pref = nla_get_u32(tb[FRA_PRIORITY]); 302 303 if (tb[FRA_IIFNAME]) { 304 struct net_device *dev; 305 306 rule->iifindex = -1; 307 nla_strlcpy(rule->iifname, tb[FRA_IIFNAME], IFNAMSIZ); 308 dev = __dev_get_by_name(net, rule->iifname); 309 if (dev) 310 rule->iifindex = dev->ifindex; 311 } 312 313 if (tb[FRA_OIFNAME]) { 314 struct net_device *dev; 315 316 rule->oifindex = -1; 317 nla_strlcpy(rule->oifname, tb[FRA_OIFNAME], IFNAMSIZ); 318 dev = __dev_get_by_name(net, rule->oifname); 319 if (dev) 320 rule->oifindex = dev->ifindex; 321 } 322 323 if (tb[FRA_FWMARK]) { 324 rule->mark = nla_get_u32(tb[FRA_FWMARK]); 325 if (rule->mark) 326 /* compatibility: if the mark value is non-zero all bits 327 * are compared unless a mask is explicitly specified. 328 */ 329 rule->mark_mask = 0xFFFFFFFF; 330 } 331 332 if (tb[FRA_FWMASK]) 333 rule->mark_mask = nla_get_u32(tb[FRA_FWMASK]); 334 335 rule->action = frh->action; 336 rule->flags = frh->flags; 337 rule->table = frh_get_table(frh, tb); 338 339 if (!tb[FRA_PRIORITY] && ops->default_pref) 340 rule->pref = ops->default_pref(ops); 341 342 err = -EINVAL; 343 if (tb[FRA_GOTO]) { 344 if (rule->action != FR_ACT_GOTO) 345 goto errout_free; 346 347 rule->target = nla_get_u32(tb[FRA_GOTO]); 348 /* Backward jumps are prohibited to avoid endless loops */ 349 if (rule->target <= rule->pref) 350 goto errout_free; 351 352 list_for_each_entry(r, &ops->rules_list, list) { 353 if (r->pref == rule->target) { 354 RCU_INIT_POINTER(rule->ctarget, r); 355 break; 356 } 357 } 358 359 if (rcu_dereference_protected(rule->ctarget, 1) == NULL) 360 unresolved = 1; 361 } else if (rule->action == FR_ACT_GOTO) 362 goto errout_free; 363 364 err = ops->configure(rule, skb, frh, tb); 365 if (err < 0) 366 goto errout_free; 367 368 list_for_each_entry(r, &ops->rules_list, list) { 369 if (r->pref > rule->pref) 370 break; 371 last = r; 372 } 373 374 fib_rule_get(rule); 375 376 if (last) 377 list_add_rcu(&rule->list, &last->list); 378 else 379 list_add_rcu(&rule->list, &ops->rules_list); 380 381 if (ops->unresolved_rules) { 382 /* 383 * There are unresolved goto rules in the list, check if 384 * any of them are pointing to this new rule. 385 */ 386 list_for_each_entry(r, &ops->rules_list, list) { 387 if (r->action == FR_ACT_GOTO && 388 r->target == rule->pref && 389 rtnl_dereference(r->ctarget) == NULL) { 390 rcu_assign_pointer(r->ctarget, rule); 391 if (--ops->unresolved_rules == 0) 392 break; 393 } 394 } 395 } 396 397 if (rule->action == FR_ACT_GOTO) 398 ops->nr_goto_rules++; 399 400 if (unresolved) 401 ops->unresolved_rules++; 402 403 notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).pid); 404 flush_route_cache(ops); 405 rules_ops_put(ops); 406 return 0; 407 408 errout_free: 409 release_net(rule->fr_net); 410 kfree(rule); 411 errout: 412 rules_ops_put(ops); 413 return err; 414 } 415 416 static int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 417 { 418 struct net *net = sock_net(skb->sk); 419 struct fib_rule_hdr *frh = nlmsg_data(nlh); 420 struct fib_rules_ops *ops = NULL; 421 struct fib_rule *rule, *tmp; 422 struct nlattr *tb[FRA_MAX+1]; 423 int err = -EINVAL; 424 425 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) 426 goto errout; 427 428 ops = lookup_rules_ops(net, frh->family); 429 if (ops == NULL) { 430 err = -EAFNOSUPPORT; 431 goto errout; 432 } 433 434 err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy); 435 if (err < 0) 436 goto errout; 437 438 err = validate_rulemsg(frh, tb, ops); 439 if (err < 0) 440 goto errout; 441 442 list_for_each_entry(rule, &ops->rules_list, list) { 443 if (frh->action && (frh->action != rule->action)) 444 continue; 445 446 if (frh->table && (frh_get_table(frh, tb) != rule->table)) 447 continue; 448 449 if (tb[FRA_PRIORITY] && 450 (rule->pref != nla_get_u32(tb[FRA_PRIORITY]))) 451 continue; 452 453 if (tb[FRA_IIFNAME] && 454 nla_strcmp(tb[FRA_IIFNAME], rule->iifname)) 455 continue; 456 457 if (tb[FRA_OIFNAME] && 458 nla_strcmp(tb[FRA_OIFNAME], rule->oifname)) 459 continue; 460 461 if (tb[FRA_FWMARK] && 462 (rule->mark != nla_get_u32(tb[FRA_FWMARK]))) 463 continue; 464 465 if (tb[FRA_FWMASK] && 466 (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK]))) 467 continue; 468 469 if (!ops->compare(rule, frh, tb)) 470 continue; 471 472 if (rule->flags & FIB_RULE_PERMANENT) { 473 err = -EPERM; 474 goto errout; 475 } 476 477 list_del_rcu(&rule->list); 478 479 if (rule->action == FR_ACT_GOTO) { 480 ops->nr_goto_rules--; 481 if (rtnl_dereference(rule->ctarget) == NULL) 482 ops->unresolved_rules--; 483 } 484 485 /* 486 * Check if this rule is a target to any of them. If so, 487 * disable them. As this operation is eventually very 488 * expensive, it is only performed if goto rules have 489 * actually been added. 490 */ 491 if (ops->nr_goto_rules > 0) { 492 list_for_each_entry(tmp, &ops->rules_list, list) { 493 if (rtnl_dereference(tmp->ctarget) == rule) { 494 RCU_INIT_POINTER(tmp->ctarget, NULL); 495 ops->unresolved_rules++; 496 } 497 } 498 } 499 500 notify_rule_change(RTM_DELRULE, rule, ops, nlh, 501 NETLINK_CB(skb).pid); 502 fib_rule_put(rule); 503 flush_route_cache(ops); 504 rules_ops_put(ops); 505 return 0; 506 } 507 508 err = -ENOENT; 509 errout: 510 rules_ops_put(ops); 511 return err; 512 } 513 514 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops, 515 struct fib_rule *rule) 516 { 517 size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr)) 518 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */ 519 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */ 520 + nla_total_size(4) /* FRA_PRIORITY */ 521 + nla_total_size(4) /* FRA_TABLE */ 522 + nla_total_size(4) /* FRA_FWMARK */ 523 + nla_total_size(4); /* FRA_FWMASK */ 524 525 if (ops->nlmsg_payload) 526 payload += ops->nlmsg_payload(rule); 527 528 return payload; 529 } 530 531 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule, 532 u32 pid, u32 seq, int type, int flags, 533 struct fib_rules_ops *ops) 534 { 535 struct nlmsghdr *nlh; 536 struct fib_rule_hdr *frh; 537 538 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags); 539 if (nlh == NULL) 540 return -EMSGSIZE; 541 542 frh = nlmsg_data(nlh); 543 frh->family = ops->family; 544 frh->table = rule->table; 545 NLA_PUT_U32(skb, FRA_TABLE, rule->table); 546 frh->res1 = 0; 547 frh->res2 = 0; 548 frh->action = rule->action; 549 frh->flags = rule->flags; 550 551 if (rule->action == FR_ACT_GOTO && 552 rcu_access_pointer(rule->ctarget) == NULL) 553 frh->flags |= FIB_RULE_UNRESOLVED; 554 555 if (rule->iifname[0]) { 556 NLA_PUT_STRING(skb, FRA_IIFNAME, rule->iifname); 557 558 if (rule->iifindex == -1) 559 frh->flags |= FIB_RULE_IIF_DETACHED; 560 } 561 562 if (rule->oifname[0]) { 563 NLA_PUT_STRING(skb, FRA_OIFNAME, rule->oifname); 564 565 if (rule->oifindex == -1) 566 frh->flags |= FIB_RULE_OIF_DETACHED; 567 } 568 569 if (rule->pref) 570 NLA_PUT_U32(skb, FRA_PRIORITY, rule->pref); 571 572 if (rule->mark) 573 NLA_PUT_U32(skb, FRA_FWMARK, rule->mark); 574 575 if (rule->mark_mask || rule->mark) 576 NLA_PUT_U32(skb, FRA_FWMASK, rule->mark_mask); 577 578 if (rule->target) 579 NLA_PUT_U32(skb, FRA_GOTO, rule->target); 580 581 if (ops->fill(rule, skb, frh) < 0) 582 goto nla_put_failure; 583 584 return nlmsg_end(skb, nlh); 585 586 nla_put_failure: 587 nlmsg_cancel(skb, nlh); 588 return -EMSGSIZE; 589 } 590 591 static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb, 592 struct fib_rules_ops *ops) 593 { 594 int idx = 0; 595 struct fib_rule *rule; 596 597 rcu_read_lock(); 598 list_for_each_entry_rcu(rule, &ops->rules_list, list) { 599 if (idx < cb->args[1]) 600 goto skip; 601 602 if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).pid, 603 cb->nlh->nlmsg_seq, RTM_NEWRULE, 604 NLM_F_MULTI, ops) < 0) 605 break; 606 skip: 607 idx++; 608 } 609 rcu_read_unlock(); 610 cb->args[1] = idx; 611 rules_ops_put(ops); 612 613 return skb->len; 614 } 615 616 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb) 617 { 618 struct net *net = sock_net(skb->sk); 619 struct fib_rules_ops *ops; 620 int idx = 0, family; 621 622 family = rtnl_msg_family(cb->nlh); 623 if (family != AF_UNSPEC) { 624 /* Protocol specific dump request */ 625 ops = lookup_rules_ops(net, family); 626 if (ops == NULL) 627 return -EAFNOSUPPORT; 628 629 return dump_rules(skb, cb, ops); 630 } 631 632 rcu_read_lock(); 633 list_for_each_entry_rcu(ops, &net->rules_ops, list) { 634 if (idx < cb->args[0] || !try_module_get(ops->owner)) 635 goto skip; 636 637 if (dump_rules(skb, cb, ops) < 0) 638 break; 639 640 cb->args[1] = 0; 641 skip: 642 idx++; 643 } 644 rcu_read_unlock(); 645 cb->args[0] = idx; 646 647 return skb->len; 648 } 649 650 static void notify_rule_change(int event, struct fib_rule *rule, 651 struct fib_rules_ops *ops, struct nlmsghdr *nlh, 652 u32 pid) 653 { 654 struct net *net; 655 struct sk_buff *skb; 656 int err = -ENOBUFS; 657 658 net = ops->fro_net; 659 skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL); 660 if (skb == NULL) 661 goto errout; 662 663 err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops); 664 if (err < 0) { 665 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */ 666 WARN_ON(err == -EMSGSIZE); 667 kfree_skb(skb); 668 goto errout; 669 } 670 671 rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL); 672 return; 673 errout: 674 if (err < 0) 675 rtnl_set_sk_err(net, ops->nlgroup, err); 676 } 677 678 static void attach_rules(struct list_head *rules, struct net_device *dev) 679 { 680 struct fib_rule *rule; 681 682 list_for_each_entry(rule, rules, list) { 683 if (rule->iifindex == -1 && 684 strcmp(dev->name, rule->iifname) == 0) 685 rule->iifindex = dev->ifindex; 686 if (rule->oifindex == -1 && 687 strcmp(dev->name, rule->oifname) == 0) 688 rule->oifindex = dev->ifindex; 689 } 690 } 691 692 static void detach_rules(struct list_head *rules, struct net_device *dev) 693 { 694 struct fib_rule *rule; 695 696 list_for_each_entry(rule, rules, list) { 697 if (rule->iifindex == dev->ifindex) 698 rule->iifindex = -1; 699 if (rule->oifindex == dev->ifindex) 700 rule->oifindex = -1; 701 } 702 } 703 704 705 static int fib_rules_event(struct notifier_block *this, unsigned long event, 706 void *ptr) 707 { 708 struct net_device *dev = ptr; 709 struct net *net = dev_net(dev); 710 struct fib_rules_ops *ops; 711 712 ASSERT_RTNL(); 713 714 switch (event) { 715 case NETDEV_REGISTER: 716 list_for_each_entry(ops, &net->rules_ops, list) 717 attach_rules(&ops->rules_list, dev); 718 break; 719 720 case NETDEV_UNREGISTER: 721 list_for_each_entry(ops, &net->rules_ops, list) 722 detach_rules(&ops->rules_list, dev); 723 break; 724 } 725 726 return NOTIFY_DONE; 727 } 728 729 static struct notifier_block fib_rules_notifier = { 730 .notifier_call = fib_rules_event, 731 }; 732 733 static int __net_init fib_rules_net_init(struct net *net) 734 { 735 INIT_LIST_HEAD(&net->rules_ops); 736 spin_lock_init(&net->rules_mod_lock); 737 return 0; 738 } 739 740 static struct pernet_operations fib_rules_net_ops = { 741 .init = fib_rules_net_init, 742 }; 743 744 static int __init fib_rules_init(void) 745 { 746 int err; 747 rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, NULL); 748 rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, NULL); 749 rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, NULL); 750 751 err = register_pernet_subsys(&fib_rules_net_ops); 752 if (err < 0) 753 goto fail; 754 755 err = register_netdevice_notifier(&fib_rules_notifier); 756 if (err < 0) 757 goto fail_unregister; 758 759 return 0; 760 761 fail_unregister: 762 unregister_pernet_subsys(&fib_rules_net_ops); 763 fail: 764 rtnl_unregister(PF_UNSPEC, RTM_NEWRULE); 765 rtnl_unregister(PF_UNSPEC, RTM_DELRULE); 766 rtnl_unregister(PF_UNSPEC, RTM_GETRULE); 767 return err; 768 } 769 770 subsys_initcall(fib_rules_init); 771