net/core/fib_rules.c

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