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->table && (frh_get_table(frh, tb) != rule->table))
 449                         continue;
 450
 451                 if (tb[FRA_PRIORITY] &&
 452                     (rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
 453                         continue;
 454
 455                 if (tb[FRA_IIFNAME] &&
 456                     nla_strcmp(tb[FRA_IIFNAME], rule->iifname))
 457                         continue;
 458
 459                 if (tb[FRA_OIFNAME] &&
 460                     nla_strcmp(tb[FRA_OIFNAME], rule->oifname))
 461                         continue;
 462
 463                 if (tb[FRA_FWMARK] &&
 464                     (rule->mark != nla_get_u32(tb[FRA_FWMARK])))
 465                         continue;
 466
 467                 if (tb[FRA_FWMASK] &&
 468                     (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK])))
 469                         continue;
 470
 471                 if (!ops->compare(rule, frh, tb))
 472                         continue;
 473
 474                 if (rule->flags & FIB_RULE_PERMANENT) {
 475                         err = -EPERM;
 476                         goto errout;
 477                 }
 478
 479                 list_del_rcu(&rule->list);
 480
 481                 if (rule->action == FR_ACT_GOTO) {
 482                         ops->nr_goto_rules--;
 483                         if (rtnl_dereference(rule->ctarget) == NULL)
 484                                 ops->unresolved_rules--;
 485                 }
 486
 487                 /*
 488                  * Check if this rule is a target to any of them. If so,
 489                  * disable them. As this operation is eventually very
 490                  * expensive, it is only performed if goto rules have
 491                  * actually been added.
 492                  */
 493                 if (ops->nr_goto_rules > 0) {
 494                         list_for_each_entry(tmp, &ops->rules_list, list) {
 495                                 if (rtnl_dereference(tmp->ctarget) == rule) {
 496                                         RCU_INIT_POINTER(tmp->ctarget, NULL);
 497                                         ops->unresolved_rules++;
 498                                 }
 499                         }
 500                 }
 501
 502                 notify_rule_change(RTM_DELRULE, rule, ops, nlh,
 503                                    NETLINK_CB(skb).portid);
 504                 if (ops->delete)
 505                         ops->delete(rule);
 506                 fib_rule_put(rule);
 507                 flush_route_cache(ops);
 508                 rules_ops_put(ops);
 509                 return 0;
 510         }
 511
 512         err = -ENOENT;
 513 errout:
 514         rules_ops_put(ops);
 515         return err;
 516 }
 517
 518 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
 519                                          struct fib_rule *rule)
 520 {
 521         size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
 522                          + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
 523                          + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
 524                          + nla_total_size(4) /* FRA_PRIORITY */
 525                          + nla_total_size(4) /* FRA_TABLE */
 526                          + nla_total_size(4) /* FRA_FWMARK */
 527                          + nla_total_size(4); /* FRA_FWMASK */
 528
 529         if (ops->nlmsg_payload)
 530                 payload += ops->nlmsg_payload(rule);
 531
 532         return payload;
 533 }
 534
 535 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
 536                             u32 pid, u32 seq, int type, int flags,
 537                             struct fib_rules_ops *ops)
 538 {
 539         struct nlmsghdr *nlh;
 540         struct fib_rule_hdr *frh;
 541
 542         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
 543         if (nlh == NULL)
 544                 return -EMSGSIZE;
 545
 546         frh = nlmsg_data(nlh);
 547         frh->family = ops->family;
 548         frh->table = rule->table;
 549         if (nla_put_u32(skb, FRA_TABLE, rule->table))
 550                 goto nla_put_failure;
 551         frh->res1 = 0;
 552         frh->res2 = 0;
 553         frh->action = rule->action;
 554         frh->flags = rule->flags;
 555
 556         if (rule->action == FR_ACT_GOTO &&
 557             rcu_access_pointer(rule->ctarget) == NULL)
 558                 frh->flags |= FIB_RULE_UNRESOLVED;
 559
 560         if (rule->iifname[0]) {
 561                 if (nla_put_string(skb, FRA_IIFNAME, rule->iifname))
 562                         goto nla_put_failure;
 563                 if (rule->iifindex == -1)
 564                         frh->flags |= FIB_RULE_IIF_DETACHED;
 565         }
 566
 567         if (rule->oifname[0]) {
 568                 if (nla_put_string(skb, FRA_OIFNAME, rule->oifname))
 569                         goto nla_put_failure;
 570                 if (rule->oifindex == -1)
 571                         frh->flags |= FIB_RULE_OIF_DETACHED;
 572         }
 573
 574         if ((rule->pref &&
 575              nla_put_u32(skb, FRA_PRIORITY, rule->pref)) ||
 576             (rule->mark &&
 577              nla_put_u32(skb, FRA_FWMARK, rule->mark)) ||
 578             ((rule->mark_mask || rule->mark) &&
 579              nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) ||
 580             (rule->target &&
 581              nla_put_u32(skb, FRA_GOTO, rule->target)))
 582                 goto nla_put_failure;
 583         if (ops->fill(rule, skb, frh) < 0)
 584                 goto nla_put_failure;
 585
 586         return nlmsg_end(skb, nlh);
 587
 588 nla_put_failure:
 589         nlmsg_cancel(skb, nlh);
 590         return -EMSGSIZE;
 591 }
 592
 593 static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
 594                       struct fib_rules_ops *ops)
 595 {
 596         int idx = 0;
 597         struct fib_rule *rule;
 598
 599         rcu_read_lock();
 600         list_for_each_entry_rcu(rule, &ops->rules_list, list) {
 601                 if (idx < cb->args[1])
 602                         goto skip;
 603
 604                 if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
 605                                      cb->nlh->nlmsg_seq, RTM_NEWRULE,
 606                                      NLM_F_MULTI, ops) < 0)
 607                         break;
 608 skip:
 609                 idx++;
 610         }
 611         rcu_read_unlock();
 612         cb->args[1] = idx;
 613         rules_ops_put(ops);
 614
 615         return skb->len;
 616 }
 617
 618 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
 619 {
 620         struct net *net = sock_net(skb->sk);
 621         struct fib_rules_ops *ops;
 622         int idx = 0, family;
 623
 624         family = rtnl_msg_family(cb->nlh);
 625         if (family != AF_UNSPEC) {
 626                 /* Protocol specific dump request */
 627                 ops = lookup_rules_ops(net, family);
 628                 if (ops == NULL)
 629                         return -EAFNOSUPPORT;
 630
 631                 return dump_rules(skb, cb, ops);
 632         }
 633
 634         rcu_read_lock();
 635         list_for_each_entry_rcu(ops, &net->rules_ops, list) {
 636                 if (idx < cb->args[0] || !try_module_get(ops->owner))
 637                         goto skip;
 638
 639                 if (dump_rules(skb, cb, ops) < 0)
 640                         break;
 641
 642                 cb->args[1] = 0;
 643 skip:
 644                 idx++;
 645         }
 646         rcu_read_unlock();
 647         cb->args[0] = idx;
 648
 649         return skb->len;
 650 }
 651
 652 static void notify_rule_change(int event, struct fib_rule *rule,
 653                                struct fib_rules_ops *ops, struct nlmsghdr *nlh,
 654                                u32 pid)
 655 {
 656         struct net *net;
 657         struct sk_buff *skb;
 658         int err = -ENOBUFS;
 659
 660         net = ops->fro_net;
 661         skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
 662         if (skb == NULL)
 663                 goto errout;
 664
 665         err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
 666         if (err < 0) {
 667                 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
 668                 WARN_ON(err == -EMSGSIZE);
 669                 kfree_skb(skb);
 670                 goto errout;
 671         }
 672
 673         rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
 674         return;
 675 errout:
 676         if (err < 0)
 677                 rtnl_set_sk_err(net, ops->nlgroup, err);
 678 }
 679
 680 static void attach_rules(struct list_head *rules, struct net_device *dev)
 681 {
 682         struct fib_rule *rule;
 683
 684         list_for_each_entry(rule, rules, list) {
 685                 if (rule->iifindex == -1 &&
 686                     strcmp(dev->name, rule->iifname) == 0)
 687                         rule->iifindex = dev->ifindex;
 688                 if (rule->oifindex == -1 &&
 689                     strcmp(dev->name, rule->oifname) == 0)
 690                         rule->oifindex = dev->ifindex;
 691         }
 692 }
 693
 694 static void detach_rules(struct list_head *rules, struct net_device *dev)
 695 {
 696         struct fib_rule *rule;
 697
 698         list_for_each_entry(rule, rules, list) {
 699                 if (rule->iifindex == dev->ifindex)
 700                         rule->iifindex = -1;
 701                 if (rule->oifindex == dev->ifindex)
 702                         rule->oifindex = -1;
 703         }
 704 }
 705
 706
 707 static int fib_rules_event(struct notifier_block *this, unsigned long event,
 708                             void *ptr)
 709 {
 710         struct net_device *dev = ptr;
 711         struct net *net = dev_net(dev);
 712         struct fib_rules_ops *ops;
 713
 714         ASSERT_RTNL();
 715
 716         switch (event) {
 717         case NETDEV_REGISTER:
 718                 list_for_each_entry(ops, &net->rules_ops, list)
 719                         attach_rules(&ops->rules_list, dev);
 720                 break;
 721
 722         case NETDEV_UNREGISTER:
 723                 list_for_each_entry(ops, &net->rules_ops, list)
 724                         detach_rules(&ops->rules_list, dev);
 725                 break;
 726         }
 727
 728         return NOTIFY_DONE;
 729 }
 730
 731 static struct notifier_block fib_rules_notifier = {
 732         .notifier_call = fib_rules_event,
 733 };
 734
 735 static int __net_init fib_rules_net_init(struct net *net)
 736 {
 737         INIT_LIST_HEAD(&net->rules_ops);
 738         spin_lock_init(&net->rules_mod_lock);
 739         return 0;
 740 }
 741
 742 static struct pernet_operations fib_rules_net_ops = {
 743         .init = fib_rules_net_init,
 744 };
 745
 746 static int __init fib_rules_init(void)
 747 {
 748         int err;
 749         rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, NULL);
 750         rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, NULL);
 751         rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, NULL);
 752
 753         err = register_pernet_subsys(&fib_rules_net_ops);
 754         if (err < 0)
 755                 goto fail;
 756
 757         err = register_netdevice_notifier(&fib_rules_notifier);
 758         if (err < 0)
 759                 goto fail_unregister;
 760
 761         return 0;
 762
 763 fail_unregister:
 764         unregister_pernet_subsys(&fib_rules_net_ops);
 765 fail:
 766         rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
 767         rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
 768         rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
 769         return err;
 770 }
 771
 772 subsys_initcall(fib_rules_init);