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/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                 if (ops->delete)
 155                         ops->delete(rule);
 156                 fib_rule_put(rule);
 157         }
 158 }
 159
 160 static void fib_rules_put_rcu(struct rcu_head *head)
 161 {
 162         struct fib_rules_ops *ops = container_of(head, struct fib_rules_ops, rcu);
 163         struct net *net = ops->fro_net;
 164
 165         release_net(net);
 166         kfree(ops);
 167 }
 168
 169 void fib_rules_unregister(struct fib_rules_ops *ops)
 170 {
 171         struct net *net = ops->fro_net;
 172
 173         spin_lock(&net->rules_mod_lock);
 174         list_del_rcu(&ops->list);
 175         fib_rules_cleanup_ops(ops);
 176         spin_unlock(&net->rules_mod_lock);
 177
 178         call_rcu(&ops->rcu, fib_rules_put_rcu);
 179 }
 180 EXPORT_SYMBOL_GPL(fib_rules_unregister);
 181
 182 static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
 183                           struct flowi *fl, int flags)
 184 {
 185         int ret = 0;
 186
 187         if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
 188                 goto out;
 189
 190         if (rule->oifindex && (rule->oifindex != fl->flowi_oif))
 191                 goto out;
 192
 193         if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask)
 194                 goto out;
 195
 196         ret = ops->match(rule, fl, flags);
 197 out:
 198         return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
 199 }
 200
 201 int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
 202                      int flags, struct fib_lookup_arg *arg)
 203 {
 204         struct fib_rule *rule;
 205         int err;
 206
 207         rcu_read_lock();
 208
 209         list_for_each_entry_rcu(rule, &ops->rules_list, list) {
 210 jumped:
 211                 if (!fib_rule_match(rule, ops, fl, flags))
 212                         continue;
 213
 214                 if (rule->action == FR_ACT_GOTO) {
 215                         struct fib_rule *target;
 216
 217                         target = rcu_dereference(rule->ctarget);
 218                         if (target == NULL) {
 219                                 continue;
 220                         } else {
 221                                 rule = target;
 222                                 goto jumped;
 223                         }
 224                 } else if (rule->action == FR_ACT_NOP)
 225                         continue;
 226                 else
 227                         err = ops->action(rule, fl, flags, arg);
 228
 229                 if (err != -EAGAIN) {
 230                         if ((arg->flags & FIB_LOOKUP_NOREF) ||
 231                             likely(atomic_inc_not_zero(&rule->refcnt))) {
 232                                 arg->rule = rule;
 233                                 goto out;
 234                         }
 235                         break;
 236                 }
 237         }
 238
 239         err = -ESRCH;
 240 out:
 241         rcu_read_unlock();
 242
 243         return err;
 244 }
 245 EXPORT_SYMBOL_GPL(fib_rules_lookup);
 246
 247 static int validate_rulemsg(struct fib_rule_hdr *frh, struct nlattr **tb,
 248                             struct fib_rules_ops *ops)
 249 {
 250         int err = -EINVAL;
 251
 252         if (frh->src_len)
 253                 if (tb[FRA_SRC] == NULL ||
 254                     frh->src_len > (ops->addr_size * 8) ||
 255                     nla_len(tb[FRA_SRC]) != ops->addr_size)
 256                         goto errout;
 257
 258         if (frh->dst_len)
 259                 if (tb[FRA_DST] == NULL ||
 260                     frh->dst_len > (ops->addr_size * 8) ||
 261                     nla_len(tb[FRA_DST]) != ops->addr_size)
 262                         goto errout;
 263
 264         err = 0;
 265 errout:
 266         return err;
 267 }
 268
 269 static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh)
 270 {
 271         struct net *net = sock_net(skb->sk);
 272         struct fib_rule_hdr *frh = nlmsg_data(nlh);
 273         struct fib_rules_ops *ops = NULL;
 274         struct fib_rule *rule, *r, *last = NULL;
 275         struct nlattr *tb[FRA_MAX+1];
 276         int err = -EINVAL, unresolved = 0;
 277
 278         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
 279                 goto errout;
 280
 281         ops = lookup_rules_ops(net, frh->family);
 282         if (ops == NULL) {
 283                 err = -EAFNOSUPPORT;
 284                 goto errout;
 285         }
 286
 287         err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
 288         if (err < 0)
 289                 goto errout;
 290
 291         err = validate_rulemsg(frh, tb, ops);
 292         if (err < 0)
 293                 goto errout;
 294
 295         rule = kzalloc(ops->rule_size, GFP_KERNEL);
 296         if (rule == NULL) {
 297                 err = -ENOMEM;
 298                 goto errout;
 299         }
 300         rule->fr_net = hold_net(net);
 301
 302         if (tb[FRA_PRIORITY])
 303                 rule->pref = nla_get_u32(tb[FRA_PRIORITY]);
 304
 305         if (tb[FRA_IIFNAME]) {
 306                 struct net_device *dev;
 307
 308                 rule->iifindex = -1;
 309                 nla_strlcpy(rule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
 310                 dev = __dev_get_by_name(net, rule->iifname);
 311                 if (dev)
 312                         rule->iifindex = dev->ifindex;
 313         }
 314
 315         if (tb[FRA_OIFNAME]) {
 316                 struct net_device *dev;
 317
 318                 rule->oifindex = -1;
 319                 nla_strlcpy(rule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
 320                 dev = __dev_get_by_name(net, rule->oifname);
 321                 if (dev)
 322                         rule->oifindex = dev->ifindex;
 323         }
 324
 325         if (tb[FRA_FWMARK]) {
 326                 rule->mark = nla_get_u32(tb[FRA_FWMARK]);
 327                 if (rule->mark)
 328                         /* compatibility: if the mark value is non-zero all bits
 329                          * are compared unless a mask is explicitly specified.
 330                          */
 331                         rule->mark_mask = 0xFFFFFFFF;
 332         }
 333
 334         if (tb[FRA_FWMASK])
 335                 rule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
 336
 337         rule->action = frh->action;
 338         rule->flags = frh->flags;
 339         rule->table = frh_get_table(frh, tb);
 340
 341         if (!tb[FRA_PRIORITY] && ops->default_pref)
 342                 rule->pref = ops->default_pref(ops);
 343
 344         err = -EINVAL;
 345         if (tb[FRA_GOTO]) {
 346                 if (rule->action != FR_ACT_GOTO)
 347                         goto errout_free;
 348
 349                 rule->target = nla_get_u32(tb[FRA_GOTO]);
 350                 /* Backward jumps are prohibited to avoid endless loops */
 351                 if (rule->target <= rule->pref)
 352                         goto errout_free;
 353
 354                 list_for_each_entry(r, &ops->rules_list, list) {
 355                         if (r->pref == rule->target) {
 356                                 RCU_INIT_POINTER(rule->ctarget, r);
 357                                 break;
 358                         }
 359                 }
 360
 361                 if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
 362                         unresolved = 1;
 363         } else if (rule->action == FR_ACT_GOTO)
 364                 goto errout_free;
 365
 366         err = ops->configure(rule, skb, frh, tb);
 367         if (err < 0)
 368                 goto errout_free;
 369
 370         list_for_each_entry(r, &ops->rules_list, list) {
 371                 if (r->pref > rule->pref)
 372                         break;
 373                 last = r;
 374         }
 375
 376         fib_rule_get(rule);
 377
 378         if (last)
 379                 list_add_rcu(&rule->list, &last->list);
 380         else
 381                 list_add_rcu(&rule->list, &ops->rules_list);
 382
 383         if (ops->unresolved_rules) {
 384                 /*
 385                  * There are unresolved goto rules in the list, check if
 386                  * any of them are pointing to this new rule.
 387                  */
 388                 list_for_each_entry(r, &ops->rules_list, list) {
 389                         if (r->action == FR_ACT_GOTO &&
 390                             r->target == rule->pref &&
 391                             rtnl_dereference(r->ctarget) == NULL) {
 392                                 rcu_assign_pointer(r->ctarget, rule);
 393                                 if (--ops->unresolved_rules == 0)
 394                                         break;
 395                         }
 396                 }
 397         }
 398
 399         if (rule->action == FR_ACT_GOTO)
 400                 ops->nr_goto_rules++;
 401
 402         if (unresolved)
 403                 ops->unresolved_rules++;
 404
 405         notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
 406         flush_route_cache(ops);
 407         rules_ops_put(ops);
 408         return 0;
 409
 410 errout_free:
 411         release_net(rule->fr_net);
 412         kfree(rule);
 413 errout:
 414         rules_ops_put(ops);
 415         return err;
 416 }
 417
 418 static int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh)
 419 {
 420         struct net *net = sock_net(skb->sk);
 421         struct fib_rule_hdr *frh = nlmsg_data(nlh);
 422         struct fib_rules_ops *ops = NULL;
 423         struct fib_rule *rule, *tmp;
 424         struct nlattr *tb[FRA_MAX+1];
 425         int err = -EINVAL;
 426
 427         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
 428                 goto errout;
 429
 430         ops = lookup_rules_ops(net, frh->family);
 431         if (ops == NULL) {
 432                 err = -EAFNOSUPPORT;
 433                 goto errout;
 434         }
 435
 436         err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
 437         if (err < 0)
 438                 goto errout;
 439
 440         err = validate_rulemsg(frh, tb, ops);
 441         if (err < 0)
 442                 goto errout;
 443
 444         list_for_each_entry(rule, &ops->rules_list, list) {
 445                 if (frh->action && (frh->action != rule->action))
 446                         continue;
 447
 448                 if (frh_get_table(frh, tb) &&
 449                     (frh_get_table(frh, tb) != rule->table))
 450                         continue;
 451
 452                 if (tb[FRA_PRIORITY] &&
 453                     (rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
 454                         continue;
 455
 456                 if (tb[FRA_IIFNAME] &&
 457                     nla_strcmp(tb[FRA_IIFNAME], rule->iifname))
 458                         continue;
 459
 460                 if (tb[FRA_OIFNAME] &&
 461                     nla_strcmp(tb[FRA_OIFNAME], rule->oifname))
 462                         continue;
 463
 464                 if (tb[FRA_FWMARK] &&
 465                     (rule->mark != nla_get_u32(tb[FRA_FWMARK])))
 466                         continue;
 467
 468                 if (tb[FRA_FWMASK] &&
 469                     (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK])))
 470                         continue;
 471
 472                 if (!ops->compare(rule, frh, tb))
 473                         continue;
 474
 475                 if (rule->flags & FIB_RULE_PERMANENT) {
 476                         err = -EPERM;
 477                         goto errout;
 478                 }
 479
 480                 list_del_rcu(&rule->list);
 481
 482                 if (rule->action == FR_ACT_GOTO) {
 483                         ops->nr_goto_rules--;
 484                         if (rtnl_dereference(rule->ctarget) == NULL)
 485                                 ops->unresolved_rules--;
 486                 }
 487
 488                 /*
 489                  * Check if this rule is a target to any of them. If so,
 490                  * disable them. As this operation is eventually very
 491                  * expensive, it is only performed if goto rules have
 492                  * actually been added.
 493                  */
 494                 if (ops->nr_goto_rules > 0) {
 495                         list_for_each_entry(tmp, &ops->rules_list, list) {
 496                                 if (rtnl_dereference(tmp->ctarget) == rule) {
 497                                         RCU_INIT_POINTER(tmp->ctarget, NULL);
 498                                         ops->unresolved_rules++;
 499                                 }
 500                         }
 501                 }
 502
 503                 notify_rule_change(RTM_DELRULE, rule, ops, nlh,
 504                                    NETLINK_CB(skb).portid);
 505                 if (ops->delete)
 506                         ops->delete(rule);
 507                 fib_rule_put(rule);
 508                 flush_route_cache(ops);
 509                 rules_ops_put(ops);
 510                 return 0;
 511         }
 512
 513         err = -ENOENT;
 514 errout:
 515         rules_ops_put(ops);
 516         return err;
 517 }
 518
 519 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
 520                                          struct fib_rule *rule)
 521 {
 522         size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
 523                          + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
 524                          + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
 525                          + nla_total_size(4) /* FRA_PRIORITY */
 526                          + nla_total_size(4) /* FRA_TABLE */
 527                          + nla_total_size(4) /* FRA_FWMARK */
 528                          + nla_total_size(4); /* FRA_FWMASK */
 529
 530         if (ops->nlmsg_payload)
 531                 payload += ops->nlmsg_payload(rule);
 532
 533         return payload;
 534 }
 535
 536 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
 537                             u32 pid, u32 seq, int type, int flags,
 538                             struct fib_rules_ops *ops)
 539 {
 540         struct nlmsghdr *nlh;
 541         struct fib_rule_hdr *frh;
 542
 543         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
 544         if (nlh == NULL)
 545                 return -EMSGSIZE;
 546
 547         frh = nlmsg_data(nlh);
 548         frh->family = ops->family;
 549         frh->table = rule->table;
 550         if (nla_put_u32(skb, FRA_TABLE, rule->table))
 551                 goto nla_put_failure;
 552         frh->res1 = 0;
 553         frh->res2 = 0;
 554         frh->action = rule->action;
 555         frh->flags = rule->flags;
 556
 557         if (rule->action == FR_ACT_GOTO &&
 558             rcu_access_pointer(rule->ctarget) == NULL)
 559                 frh->flags |= FIB_RULE_UNRESOLVED;
 560
 561         if (rule->iifname[0]) {
 562                 if (nla_put_string(skb, FRA_IIFNAME, rule->iifname))
 563                         goto nla_put_failure;
 564                 if (rule->iifindex == -1)
 565                         frh->flags |= FIB_RULE_IIF_DETACHED;
 566         }
 567
 568         if (rule->oifname[0]) {
 569                 if (nla_put_string(skb, FRA_OIFNAME, rule->oifname))
 570                         goto nla_put_failure;
 571                 if (rule->oifindex == -1)
 572                         frh->flags |= FIB_RULE_OIF_DETACHED;
 573         }
 574
 575         if ((rule->pref &&
 576              nla_put_u32(skb, FRA_PRIORITY, rule->pref)) ||
 577             (rule->mark &&
 578              nla_put_u32(skb, FRA_FWMARK, rule->mark)) ||
 579             ((rule->mark_mask || rule->mark) &&
 580              nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) ||
 581             (rule->target &&
 582              nla_put_u32(skb, FRA_GOTO, rule->target)))
 583                 goto nla_put_failure;
 584         if (ops->fill(rule, skb, frh) < 0)
 585                 goto nla_put_failure;
 586
 587         return nlmsg_end(skb, nlh);
 588
 589 nla_put_failure:
 590         nlmsg_cancel(skb, nlh);
 591         return -EMSGSIZE;
 592 }
 593
 594 static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
 595                       struct fib_rules_ops *ops)
 596 {
 597         int idx = 0;
 598         struct fib_rule *rule;
 599
 600         rcu_read_lock();
 601         list_for_each_entry_rcu(rule, &ops->rules_list, list) {
 602                 if (idx < cb->args[1])
 603                         goto skip;
 604
 605                 if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
 606                                      cb->nlh->nlmsg_seq, RTM_NEWRULE,
 607                                      NLM_F_MULTI, ops) < 0)
 608                         break;
 609 skip:
 610                 idx++;
 611         }
 612         rcu_read_unlock();
 613         cb->args[1] = idx;
 614         rules_ops_put(ops);
 615
 616         return skb->len;
 617 }
 618
 619 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
 620 {
 621         struct net *net = sock_net(skb->sk);
 622         struct fib_rules_ops *ops;
 623         int idx = 0, family;
 624
 625         family = rtnl_msg_family(cb->nlh);
 626         if (family != AF_UNSPEC) {
 627                 /* Protocol specific dump request */
 628                 ops = lookup_rules_ops(net, family);
 629                 if (ops == NULL)
 630                         return -EAFNOSUPPORT;
 631
 632                 return dump_rules(skb, cb, ops);
 633         }
 634
 635         rcu_read_lock();
 636         list_for_each_entry_rcu(ops, &net->rules_ops, list) {
 637                 if (idx < cb->args[0] || !try_module_get(ops->owner))
 638                         goto skip;
 639
 640                 if (dump_rules(skb, cb, ops) < 0)
 641                         break;
 642
 643                 cb->args[1] = 0;
 644 skip:
 645                 idx++;
 646         }
 647         rcu_read_unlock();
 648         cb->args[0] = idx;
 649
 650         return skb->len;
 651 }
 652
 653 static void notify_rule_change(int event, struct fib_rule *rule,
 654                                struct fib_rules_ops *ops, struct nlmsghdr *nlh,
 655                                u32 pid)
 656 {
 657         struct net *net;
 658         struct sk_buff *skb;
 659         int err = -ENOBUFS;
 660
 661         net = ops->fro_net;
 662         skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
 663         if (skb == NULL)
 664                 goto errout;
 665
 666         err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
 667         if (err < 0) {
 668                 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
 669                 WARN_ON(err == -EMSGSIZE);
 670                 kfree_skb(skb);
 671                 goto errout;
 672         }
 673
 674         rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
 675         return;
 676 errout:
 677         if (err < 0)
 678                 rtnl_set_sk_err(net, ops->nlgroup, err);
 679 }
 680
 681 static void attach_rules(struct list_head *rules, struct net_device *dev)
 682 {
 683         struct fib_rule *rule;
 684
 685         list_for_each_entry(rule, rules, list) {
 686                 if (rule->iifindex == -1 &&
 687                     strcmp(dev->name, rule->iifname) == 0)
 688                         rule->iifindex = dev->ifindex;
 689                 if (rule->oifindex == -1 &&
 690                     strcmp(dev->name, rule->oifname) == 0)
 691                         rule->oifindex = dev->ifindex;
 692         }
 693 }
 694
 695 static void detach_rules(struct list_head *rules, struct net_device *dev)
 696 {
 697         struct fib_rule *rule;
 698
 699         list_for_each_entry(rule, rules, list) {
 700                 if (rule->iifindex == dev->ifindex)
 701                         rule->iifindex = -1;
 702                 if (rule->oifindex == dev->ifindex)
 703                         rule->oifindex = -1;
 704         }
 705 }
 706
 707
 708 static int fib_rules_event(struct notifier_block *this, unsigned long event,
 709                             void *ptr)
 710 {
 711         struct net_device *dev = ptr;
 712         struct net *net = dev_net(dev);
 713         struct fib_rules_ops *ops;
 714
 715         ASSERT_RTNL();
 716
 717         switch (event) {
 718         case NETDEV_REGISTER:
 719                 list_for_each_entry(ops, &net->rules_ops, list)
 720                         attach_rules(&ops->rules_list, dev);
 721                 break;
 722
 723         case NETDEV_CHANGENAME:
 724                 list_for_each_entry(ops, &net->rules_ops, list) {
 725                         detach_rules(&ops->rules_list, dev);
 726                         attach_rules(&ops->rules_list, dev);
 727                 }
 728                 break;
 729
 730         case NETDEV_UNREGISTER:
 731                 list_for_each_entry(ops, &net->rules_ops, list)
 732                         detach_rules(&ops->rules_list, dev);
 733                 break;
 734         }
 735
 736         return NOTIFY_DONE;
 737 }
 738
 739 static struct notifier_block fib_rules_notifier = {
 740         .notifier_call = fib_rules_event,
 741 };
 742
 743 static int __net_init fib_rules_net_init(struct net *net)
 744 {
 745         INIT_LIST_HEAD(&net->rules_ops);
 746         spin_lock_init(&net->rules_mod_lock);
 747         return 0;
 748 }
 749
 750 static struct pernet_operations fib_rules_net_ops = {
 751         .init = fib_rules_net_init,
 752 };
 753
 754 static int __init fib_rules_init(void)
 755 {
 756         int err;
 757         rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, NULL);
 758         rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, NULL);
 759         rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, NULL);
 760
 761         err = register_pernet_subsys(&fib_rules_net_ops);
 762         if (err < 0)
 763                 goto fail;
 764
 765         err = register_netdevice_notifier(&fib_rules_notifier);
 766         if (err < 0)
 767                 goto fail_unregister;
 768
 769         return 0;
 770
 771 fail_unregister:
 772         unregister_pernet_subsys(&fib_rules_net_ops);
 773 fail:
 774         rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
 775         rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
 776         rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
 777         return err;
 778 }
 779
 780 subsys_initcall(fib_rules_init);