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 #include <net/ip_tunnels.h>
  20
  21 int fib_default_rule_add(struct fib_rules_ops *ops,
  22                          u32 pref, u32 table, u32 flags)
  23 {
  24         struct fib_rule *r;
  25
  26         r = kzalloc(ops->rule_size, GFP_KERNEL);
  27         if (r == NULL)
  28                 return -ENOMEM;
  29
  30         atomic_set(&r->refcnt, 1);
  31         r->action = FR_ACT_TO_TBL;
  32         r->pref = pref;
  33         r->table = table;
  34         r->flags = flags;
  35         r->fr_net = ops->fro_net;
  36
  37         r->suppress_prefixlen = -1;
  38         r->suppress_ifgroup = -1;
  39
  40         /* The lock is not required here, the list in unreacheable
  41          * at the moment this function is called */
  42         list_add_tail(&r->list, &ops->rules_list);
  43         return 0;
  44 }
  45 EXPORT_SYMBOL(fib_default_rule_add);
  46
  47 static u32 fib_default_rule_pref(struct fib_rules_ops *ops)
  48 {
  49         struct list_head *pos;
  50         struct fib_rule *rule;
  51
  52         if (!list_empty(&ops->rules_list)) {
  53                 pos = ops->rules_list.next;
  54                 if (pos->next != &ops->rules_list) {
  55                         rule = list_entry(pos->next, struct fib_rule, list);
  56                         if (rule->pref)
  57                                 return rule->pref - 1;
  58                 }
  59         }
  60
  61         return 0;
  62 }
  63
  64 static void notify_rule_change(int event, struct fib_rule *rule,
  65                                struct fib_rules_ops *ops, struct nlmsghdr *nlh,
  66                                u32 pid);
  67
  68 static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family)
  69 {
  70         struct fib_rules_ops *ops;
  71
  72         rcu_read_lock();
  73         list_for_each_entry_rcu(ops, &net->rules_ops, list) {
  74                 if (ops->family == family) {
  75                         if (!try_module_get(ops->owner))
  76                                 ops = NULL;
  77                         rcu_read_unlock();
  78                         return ops;
  79                 }
  80         }
  81         rcu_read_unlock();
  82
  83         return NULL;
  84 }
  85
  86 static void rules_ops_put(struct fib_rules_ops *ops)
  87 {
  88         if (ops)
  89                 module_put(ops->owner);
  90 }
  91
  92 static void flush_route_cache(struct fib_rules_ops *ops)
  93 {
  94         if (ops->flush_cache)
  95                 ops->flush_cache(ops);
  96 }
  97
  98 static int __fib_rules_register(struct fib_rules_ops *ops)
  99 {
 100         int err = -EEXIST;
 101         struct fib_rules_ops *o;
 102         struct net *net;
 103
 104         net = ops->fro_net;
 105
 106         if (ops->rule_size < sizeof(struct fib_rule))
 107                 return -EINVAL;
 108
 109         if (ops->match == NULL || ops->configure == NULL ||
 110             ops->compare == NULL || ops->fill == NULL ||
 111             ops->action == NULL)
 112                 return -EINVAL;
 113
 114         spin_lock(&net->rules_mod_lock);
 115         list_for_each_entry(o, &net->rules_ops, list)
 116                 if (ops->family == o->family)
 117                         goto errout;
 118
 119         list_add_tail_rcu(&ops->list, &net->rules_ops);
 120         err = 0;
 121 errout:
 122         spin_unlock(&net->rules_mod_lock);
 123
 124         return err;
 125 }
 126
 127 struct fib_rules_ops *
 128 fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net)
 129 {
 130         struct fib_rules_ops *ops;
 131         int err;
 132
 133         ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL);
 134         if (ops == NULL)
 135                 return ERR_PTR(-ENOMEM);
 136
 137         INIT_LIST_HEAD(&ops->rules_list);
 138         ops->fro_net = net;
 139
 140         err = __fib_rules_register(ops);
 141         if (err) {
 142                 kfree(ops);
 143                 ops = ERR_PTR(err);
 144         }
 145
 146         return ops;
 147 }
 148 EXPORT_SYMBOL_GPL(fib_rules_register);
 149
 150 static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
 151 {
 152         struct fib_rule *rule, *tmp;
 153
 154         list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) {
 155                 list_del_rcu(&rule->list);
 156                 if (ops->delete)
 157                         ops->delete(rule);
 158                 fib_rule_put(rule);
 159         }
 160 }
 161
 162 void fib_rules_unregister(struct fib_rules_ops *ops)
 163 {
 164         struct net *net = ops->fro_net;
 165
 166         spin_lock(&net->rules_mod_lock);
 167         list_del_rcu(&ops->list);
 168         spin_unlock(&net->rules_mod_lock);
 169
 170         fib_rules_cleanup_ops(ops);
 171         kfree_rcu(ops, rcu);
 172 }
 173 EXPORT_SYMBOL_GPL(fib_rules_unregister);
 174
 175 static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
 176                           struct flowi *fl, int flags,
 177                           struct fib_lookup_arg *arg)
 178 {
 179         int ret = 0;
 180
 181         if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
 182                 goto out;
 183
 184         if (rule->oifindex && (rule->oifindex != fl->flowi_oif))
 185                 goto out;
 186
 187         if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask)
 188                 goto out;
 189
 190         if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id))
 191                 goto out;
 192
 193         if (rule->l3mdev && !l3mdev_fib_rule_match(rule->fr_net, fl, arg))
 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, arg))
 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 && ops->suppress && ops->suppress(rule, arg))
 230                         continue;
 231
 232                 if (err != -EAGAIN) {
 233                         if ((arg->flags & FIB_LOOKUP_NOREF) ||
 234                             likely(atomic_inc_not_zero(&rule->refcnt))) {
 235                                 arg->rule = rule;
 236                                 goto out;
 237                         }
 238                         break;
 239                 }
 240         }
 241
 242         err = -ESRCH;
 243 out:
 244         rcu_read_unlock();
 245
 246         return err;
 247 }
 248 EXPORT_SYMBOL_GPL(fib_rules_lookup);
 249
 250 static int validate_rulemsg(struct fib_rule_hdr *frh, struct nlattr **tb,
 251                             struct fib_rules_ops *ops)
 252 {
 253         int err = -EINVAL;
 254
 255         if (frh->src_len)
 256                 if (tb[FRA_SRC] == NULL ||
 257                     frh->src_len > (ops->addr_size * 8) ||
 258                     nla_len(tb[FRA_SRC]) != ops->addr_size)
 259                         goto errout;
 260
 261         if (frh->dst_len)
 262                 if (tb[FRA_DST] == NULL ||
 263                     frh->dst_len > (ops->addr_size * 8) ||
 264                     nla_len(tb[FRA_DST]) != ops->addr_size)
 265                         goto errout;
 266
 267         err = 0;
 268 errout:
 269         return err;
 270 }
 271
 272 static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh,
 273                        struct nlattr **tb, struct fib_rule *rule)
 274 {
 275         struct fib_rule *r;
 276
 277         list_for_each_entry(r, &ops->rules_list, list) {
 278                 if (r->action != rule->action)
 279                         continue;
 280
 281                 if (r->table != rule->table)
 282                         continue;
 283
 284                 if (r->pref != rule->pref)
 285                         continue;
 286
 287                 if (memcmp(r->iifname, rule->iifname, IFNAMSIZ))
 288                         continue;
 289
 290                 if (memcmp(r->oifname, rule->oifname, IFNAMSIZ))
 291                         continue;
 292
 293                 if (r->mark != rule->mark)
 294                         continue;
 295
 296                 if (r->mark_mask != rule->mark_mask)
 297                         continue;
 298
 299                 if (r->tun_id != rule->tun_id)
 300                         continue;
 301
 302                 if (r->fr_net != rule->fr_net)
 303                         continue;
 304
 305                 if (r->l3mdev != rule->l3mdev)
 306                         continue;
 307
 308                 if (!ops->compare(r, frh, tb))
 309                         continue;
 310                 return 1;
 311         }
 312         return 0;
 313 }
 314
 315 int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh)
 316 {
 317         struct net *net = sock_net(skb->sk);
 318         struct fib_rule_hdr *frh = nlmsg_data(nlh);
 319         struct fib_rules_ops *ops = NULL;
 320         struct fib_rule *rule, *r, *last = NULL;
 321         struct nlattr *tb[FRA_MAX+1];
 322         int err = -EINVAL, unresolved = 0;
 323
 324         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
 325                 goto errout;
 326
 327         ops = lookup_rules_ops(net, frh->family);
 328         if (ops == NULL) {
 329                 err = -EAFNOSUPPORT;
 330                 goto errout;
 331         }
 332
 333         err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
 334         if (err < 0)
 335                 goto errout;
 336
 337         err = validate_rulemsg(frh, tb, ops);
 338         if (err < 0)
 339                 goto errout;
 340
 341         rule = kzalloc(ops->rule_size, GFP_KERNEL);
 342         if (rule == NULL) {
 343                 err = -ENOMEM;
 344                 goto errout;
 345         }
 346         rule->fr_net = net;
 347
 348         rule->pref = tb[FRA_PRIORITY] ? nla_get_u32(tb[FRA_PRIORITY])
 349                                       : fib_default_rule_pref(ops);
 350
 351         if (tb[FRA_IIFNAME]) {
 352                 struct net_device *dev;
 353
 354                 rule->iifindex = -1;
 355                 nla_strlcpy(rule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
 356                 dev = __dev_get_by_name(net, rule->iifname);
 357                 if (dev)
 358                         rule->iifindex = dev->ifindex;
 359         }
 360
 361         if (tb[FRA_OIFNAME]) {
 362                 struct net_device *dev;
 363
 364                 rule->oifindex = -1;
 365                 nla_strlcpy(rule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
 366                 dev = __dev_get_by_name(net, rule->oifname);
 367                 if (dev)
 368                         rule->oifindex = dev->ifindex;
 369         }
 370
 371         if (tb[FRA_FWMARK]) {
 372                 rule->mark = nla_get_u32(tb[FRA_FWMARK]);
 373                 if (rule->mark)
 374                         /* compatibility: if the mark value is non-zero all bits
 375                          * are compared unless a mask is explicitly specified.
 376                          */
 377                         rule->mark_mask = 0xFFFFFFFF;
 378         }
 379
 380         if (tb[FRA_FWMASK])
 381                 rule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
 382
 383         if (tb[FRA_TUN_ID])
 384                 rule->tun_id = nla_get_be64(tb[FRA_TUN_ID]);
 385
 386         if (tb[FRA_L3MDEV]) {
 387 #ifdef CONFIG_NET_L3_MASTER_DEV
 388                 rule->l3mdev = nla_get_u8(tb[FRA_L3MDEV]);
 389                 if (rule->l3mdev != 1)
 390 #endif
 391                         goto errout_free;
 392         }
 393
 394         rule->action = frh->action;
 395         rule->flags = frh->flags;
 396         rule->table = frh_get_table(frh, tb);
 397         if (tb[FRA_SUPPRESS_PREFIXLEN])
 398                 rule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
 399         else
 400                 rule->suppress_prefixlen = -1;
 401
 402         if (tb[FRA_SUPPRESS_IFGROUP])
 403                 rule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]);
 404         else
 405                 rule->suppress_ifgroup = -1;
 406
 407         err = -EINVAL;
 408         if (tb[FRA_GOTO]) {
 409                 if (rule->action != FR_ACT_GOTO)
 410                         goto errout_free;
 411
 412                 rule->target = nla_get_u32(tb[FRA_GOTO]);
 413                 /* Backward jumps are prohibited to avoid endless loops */
 414                 if (rule->target <= rule->pref)
 415                         goto errout_free;
 416
 417                 list_for_each_entry(r, &ops->rules_list, list) {
 418                         if (r->pref == rule->target) {
 419                                 RCU_INIT_POINTER(rule->ctarget, r);
 420                                 break;
 421                         }
 422                 }
 423
 424                 if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
 425                         unresolved = 1;
 426         } else if (rule->action == FR_ACT_GOTO)
 427                 goto errout_free;
 428
 429         if (rule->l3mdev && rule->table)
 430                 goto errout_free;
 431
 432         if ((nlh->nlmsg_flags & NLM_F_EXCL) &&
 433             rule_exists(ops, frh, tb, rule)) {
 434                 err = -EEXIST;
 435                 goto errout_free;
 436         }
 437
 438         err = ops->configure(rule, skb, frh, tb);
 439         if (err < 0)
 440                 goto errout_free;
 441
 442         list_for_each_entry(r, &ops->rules_list, list) {
 443                 if (r->pref > rule->pref)
 444                         break;
 445                 last = r;
 446         }
 447
 448         fib_rule_get(rule);
 449
 450         if (last)
 451                 list_add_rcu(&rule->list, &last->list);
 452         else
 453                 list_add_rcu(&rule->list, &ops->rules_list);
 454
 455         if (ops->unresolved_rules) {
 456                 /*
 457                  * There are unresolved goto rules in the list, check if
 458                  * any of them are pointing to this new rule.
 459                  */
 460                 list_for_each_entry(r, &ops->rules_list, list) {
 461                         if (r->action == FR_ACT_GOTO &&
 462                             r->target == rule->pref &&
 463                             rtnl_dereference(r->ctarget) == NULL) {
 464                                 rcu_assign_pointer(r->ctarget, rule);
 465                                 if (--ops->unresolved_rules == 0)
 466                                         break;
 467                         }
 468                 }
 469         }
 470
 471         if (rule->action == FR_ACT_GOTO)
 472                 ops->nr_goto_rules++;
 473
 474         if (unresolved)
 475                 ops->unresolved_rules++;
 476
 477         if (rule->tun_id)
 478                 ip_tunnel_need_metadata();
 479
 480         notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
 481         flush_route_cache(ops);
 482         rules_ops_put(ops);
 483         return 0;
 484
 485 errout_free:
 486         kfree(rule);
 487 errout:
 488         rules_ops_put(ops);
 489         return err;
 490 }
 491 EXPORT_SYMBOL_GPL(fib_nl_newrule);
 492
 493 int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh)
 494 {
 495         struct net *net = sock_net(skb->sk);
 496         struct fib_rule_hdr *frh = nlmsg_data(nlh);
 497         struct fib_rules_ops *ops = NULL;
 498         struct fib_rule *rule, *tmp;
 499         struct nlattr *tb[FRA_MAX+1];
 500         int err = -EINVAL;
 501
 502         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
 503                 goto errout;
 504
 505         ops = lookup_rules_ops(net, frh->family);
 506         if (ops == NULL) {
 507                 err = -EAFNOSUPPORT;
 508                 goto errout;
 509         }
 510
 511         err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
 512         if (err < 0)
 513                 goto errout;
 514
 515         err = validate_rulemsg(frh, tb, ops);
 516         if (err < 0)
 517                 goto errout;
 518
 519         list_for_each_entry(rule, &ops->rules_list, list) {
 520                 if (frh->action && (frh->action != rule->action))
 521                         continue;
 522
 523                 if (frh_get_table(frh, tb) &&
 524                     (frh_get_table(frh, tb) != rule->table))
 525                         continue;
 526
 527                 if (tb[FRA_PRIORITY] &&
 528                     (rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
 529                         continue;
 530
 531                 if (tb[FRA_IIFNAME] &&
 532                     nla_strcmp(tb[FRA_IIFNAME], rule->iifname))
 533                         continue;
 534
 535                 if (tb[FRA_OIFNAME] &&
 536                     nla_strcmp(tb[FRA_OIFNAME], rule->oifname))
 537                         continue;
 538
 539                 if (tb[FRA_FWMARK] &&
 540                     (rule->mark != nla_get_u32(tb[FRA_FWMARK])))
 541                         continue;
 542
 543                 if (tb[FRA_FWMASK] &&
 544                     (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK])))
 545                         continue;
 546
 547                 if (tb[FRA_TUN_ID] &&
 548                     (rule->tun_id != nla_get_be64(tb[FRA_TUN_ID])))
 549                         continue;
 550
 551                 if (tb[FRA_L3MDEV] &&
 552                     (rule->l3mdev != nla_get_u8(tb[FRA_L3MDEV])))
 553                         continue;
 554
 555                 if (!ops->compare(rule, frh, tb))
 556                         continue;
 557
 558                 if (rule->flags & FIB_RULE_PERMANENT) {
 559                         err = -EPERM;
 560                         goto errout;
 561                 }
 562
 563                 if (ops->delete) {
 564                         err = ops->delete(rule);
 565                         if (err)
 566                                 goto errout;
 567                 }
 568
 569                 if (rule->tun_id)
 570                         ip_tunnel_unneed_metadata();
 571
 572                 list_del_rcu(&rule->list);
 573
 574                 if (rule->action == FR_ACT_GOTO) {
 575                         ops->nr_goto_rules--;
 576                         if (rtnl_dereference(rule->ctarget) == NULL)
 577                                 ops->unresolved_rules--;
 578                 }
 579
 580                 /*
 581                  * Check if this rule is a target to any of them. If so,
 582                  * disable them. As this operation is eventually very
 583                  * expensive, it is only performed if goto rules have
 584                  * actually been added.
 585                  */
 586                 if (ops->nr_goto_rules > 0) {
 587                         list_for_each_entry(tmp, &ops->rules_list, list) {
 588                                 if (rtnl_dereference(tmp->ctarget) == rule) {
 589                                         RCU_INIT_POINTER(tmp->ctarget, NULL);
 590                                         ops->unresolved_rules++;
 591                                 }
 592                         }
 593                 }
 594
 595                 notify_rule_change(RTM_DELRULE, rule, ops, nlh,
 596                                    NETLINK_CB(skb).portid);
 597                 fib_rule_put(rule);
 598                 flush_route_cache(ops);
 599                 rules_ops_put(ops);
 600                 return 0;
 601         }
 602
 603         err = -ENOENT;
 604 errout:
 605         rules_ops_put(ops);
 606         return err;
 607 }
 608 EXPORT_SYMBOL_GPL(fib_nl_delrule);
 609
 610 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
 611                                          struct fib_rule *rule)
 612 {
 613         size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
 614                          + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
 615                          + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
 616                          + nla_total_size(4) /* FRA_PRIORITY */
 617                          + nla_total_size(4) /* FRA_TABLE */
 618                          + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */
 619                          + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */
 620                          + nla_total_size(4) /* FRA_FWMARK */
 621                          + nla_total_size(4) /* FRA_FWMASK */
 622                          + nla_total_size_64bit(8); /* FRA_TUN_ID */
 623
 624         if (ops->nlmsg_payload)
 625                 payload += ops->nlmsg_payload(rule);
 626
 627         return payload;
 628 }
 629
 630 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
 631                             u32 pid, u32 seq, int type, int flags,
 632                             struct fib_rules_ops *ops)
 633 {
 634         struct nlmsghdr *nlh;
 635         struct fib_rule_hdr *frh;
 636
 637         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
 638         if (nlh == NULL)
 639                 return -EMSGSIZE;
 640
 641         frh = nlmsg_data(nlh);
 642         frh->family = ops->family;
 643         frh->table = rule->table;
 644         if (nla_put_u32(skb, FRA_TABLE, rule->table))
 645                 goto nla_put_failure;
 646         if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen))
 647                 goto nla_put_failure;
 648         frh->res1 = 0;
 649         frh->res2 = 0;
 650         frh->action = rule->action;
 651         frh->flags = rule->flags;
 652
 653         if (rule->action == FR_ACT_GOTO &&
 654             rcu_access_pointer(rule->ctarget) == NULL)
 655                 frh->flags |= FIB_RULE_UNRESOLVED;
 656
 657         if (rule->iifname[0]) {
 658                 if (nla_put_string(skb, FRA_IIFNAME, rule->iifname))
 659                         goto nla_put_failure;
 660                 if (rule->iifindex == -1)
 661                         frh->flags |= FIB_RULE_IIF_DETACHED;
 662         }
 663
 664         if (rule->oifname[0]) {
 665                 if (nla_put_string(skb, FRA_OIFNAME, rule->oifname))
 666                         goto nla_put_failure;
 667                 if (rule->oifindex == -1)
 668                         frh->flags |= FIB_RULE_OIF_DETACHED;
 669         }
 670
 671         if ((rule->pref &&
 672              nla_put_u32(skb, FRA_PRIORITY, rule->pref)) ||
 673             (rule->mark &&
 674              nla_put_u32(skb, FRA_FWMARK, rule->mark)) ||
 675             ((rule->mark_mask || rule->mark) &&
 676              nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) ||
 677             (rule->target &&
 678              nla_put_u32(skb, FRA_GOTO, rule->target)) ||
 679             (rule->tun_id &&
 680              nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) ||
 681             (rule->l3mdev &&
 682              nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)))
 683                 goto nla_put_failure;
 684
 685         if (rule->suppress_ifgroup != -1) {
 686                 if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup))
 687                         goto nla_put_failure;
 688         }
 689
 690         if (ops->fill(rule, skb, frh) < 0)
 691                 goto nla_put_failure;
 692
 693         nlmsg_end(skb, nlh);
 694         return 0;
 695
 696 nla_put_failure:
 697         nlmsg_cancel(skb, nlh);
 698         return -EMSGSIZE;
 699 }
 700
 701 static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
 702                       struct fib_rules_ops *ops)
 703 {
 704         int idx = 0;
 705         struct fib_rule *rule;
 706         int err = 0;
 707
 708         rcu_read_lock();
 709         list_for_each_entry_rcu(rule, &ops->rules_list, list) {
 710                 if (idx < cb->args[1])
 711                         goto skip;
 712
 713                 err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
 714                                        cb->nlh->nlmsg_seq, RTM_NEWRULE,
 715                                        NLM_F_MULTI, ops);
 716                 if (err)
 717                         break;
 718 skip:
 719                 idx++;
 720         }
 721         rcu_read_unlock();
 722         cb->args[1] = idx;
 723         rules_ops_put(ops);
 724
 725         return err;
 726 }
 727
 728 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
 729 {
 730         struct net *net = sock_net(skb->sk);
 731         struct fib_rules_ops *ops;
 732         int idx = 0, family;
 733
 734         family = rtnl_msg_family(cb->nlh);
 735         if (family != AF_UNSPEC) {
 736                 /* Protocol specific dump request */
 737                 ops = lookup_rules_ops(net, family);
 738                 if (ops == NULL)
 739                         return -EAFNOSUPPORT;
 740
 741                 dump_rules(skb, cb, ops);
 742
 743                 return skb->len;
 744         }
 745
 746         rcu_read_lock();
 747         list_for_each_entry_rcu(ops, &net->rules_ops, list) {
 748                 if (idx < cb->args[0] || !try_module_get(ops->owner))
 749                         goto skip;
 750
 751                 if (dump_rules(skb, cb, ops) < 0)
 752                         break;
 753
 754                 cb->args[1] = 0;
 755 skip:
 756                 idx++;
 757         }
 758         rcu_read_unlock();
 759         cb->args[0] = idx;
 760
 761         return skb->len;
 762 }
 763
 764 static void notify_rule_change(int event, struct fib_rule *rule,
 765                                struct fib_rules_ops *ops, struct nlmsghdr *nlh,
 766                                u32 pid)
 767 {
 768         struct net *net;
 769         struct sk_buff *skb;
 770         int err = -ENOBUFS;
 771
 772         net = ops->fro_net;
 773         skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
 774         if (skb == NULL)
 775                 goto errout;
 776
 777         err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
 778         if (err < 0) {
 779                 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
 780                 WARN_ON(err == -EMSGSIZE);
 781                 kfree_skb(skb);
 782                 goto errout;
 783         }
 784
 785         rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
 786         return;
 787 errout:
 788         if (err < 0)
 789                 rtnl_set_sk_err(net, ops->nlgroup, err);
 790 }
 791
 792 static void attach_rules(struct list_head *rules, struct net_device *dev)
 793 {
 794         struct fib_rule *rule;
 795
 796         list_for_each_entry(rule, rules, list) {
 797                 if (rule->iifindex == -1 &&
 798                     strcmp(dev->name, rule->iifname) == 0)
 799                         rule->iifindex = dev->ifindex;
 800                 if (rule->oifindex == -1 &&
 801                     strcmp(dev->name, rule->oifname) == 0)
 802                         rule->oifindex = dev->ifindex;
 803         }
 804 }
 805
 806 static void detach_rules(struct list_head *rules, struct net_device *dev)
 807 {
 808         struct fib_rule *rule;
 809
 810         list_for_each_entry(rule, rules, list) {
 811                 if (rule->iifindex == dev->ifindex)
 812                         rule->iifindex = -1;
 813                 if (rule->oifindex == dev->ifindex)
 814                         rule->oifindex = -1;
 815         }
 816 }
 817
 818
 819 static int fib_rules_event(struct notifier_block *this, unsigned long event,
 820                            void *ptr)
 821 {
 822         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 823         struct net *net = dev_net(dev);
 824         struct fib_rules_ops *ops;
 825
 826         ASSERT_RTNL();
 827
 828         switch (event) {
 829         case NETDEV_REGISTER:
 830                 list_for_each_entry(ops, &net->rules_ops, list)
 831                         attach_rules(&ops->rules_list, dev);
 832                 break;
 833
 834         case NETDEV_CHANGENAME:
 835                 list_for_each_entry(ops, &net->rules_ops, list) {
 836                         detach_rules(&ops->rules_list, dev);
 837                         attach_rules(&ops->rules_list, dev);
 838                 }
 839                 break;
 840
 841         case NETDEV_UNREGISTER:
 842                 list_for_each_entry(ops, &net->rules_ops, list)
 843                         detach_rules(&ops->rules_list, dev);
 844                 break;
 845         }
 846
 847         return NOTIFY_DONE;
 848 }
 849
 850 static struct notifier_block fib_rules_notifier = {
 851         .notifier_call = fib_rules_event,
 852 };
 853
 854 static int __net_init fib_rules_net_init(struct net *net)
 855 {
 856         INIT_LIST_HEAD(&net->rules_ops);
 857         spin_lock_init(&net->rules_mod_lock);
 858         return 0;
 859 }
 860
 861 static struct pernet_operations fib_rules_net_ops = {
 862         .init = fib_rules_net_init,
 863 };
 864
 865 static int __init fib_rules_init(void)
 866 {
 867         int err;
 868         rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, NULL);
 869         rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, NULL);
 870         rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, NULL);
 871
 872         err = register_pernet_subsys(&fib_rules_net_ops);
 873         if (err < 0)
 874                 goto fail;
 875
 876         err = register_netdevice_notifier(&fib_rules_notifier);
 877         if (err < 0)
 878                 goto fail_unregister;
 879
 880         return 0;
 881
 882 fail_unregister:
 883         unregister_pernet_subsys(&fib_rules_net_ops);
 884 fail:
 885         rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
 886         rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
 887         rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
 888         return err;
 889 }
 890
 891 subsys_initcall(fib_rules_init);