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                 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);