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 static const struct fib_kuid_range fib_kuid_range_unset = {
  22         KUIDT_INIT(0),
  23         KUIDT_INIT(~0),
  24 };
  25
  26 bool fib_rule_matchall(const struct fib_rule *rule)
  27 {
  28         if (rule->iifindex || rule->oifindex || rule->mark || rule->tun_id ||
  29             rule->flags)
  30                 return false;
  31         if (rule->suppress_ifgroup != -1 || rule->suppress_prefixlen != -1)
  32                 return false;
  33         if (!uid_eq(rule->uid_range.start, fib_kuid_range_unset.start) ||
  34             !uid_eq(rule->uid_range.end, fib_kuid_range_unset.end))
  35                 return false;
  36         if (fib_rule_port_range_set(&rule->sport_range))
  37                 return false;
  38         if (fib_rule_port_range_set(&rule->dport_range))
  39                 return false;
  40         return true;
  41 }
  42 EXPORT_SYMBOL_GPL(fib_rule_matchall);
  43
  44 int fib_default_rule_add(struct fib_rules_ops *ops,
  45                          u32 pref, u32 table, u32 flags)
  46 {
  47         struct fib_rule *r;
  48
  49         r = kzalloc(ops->rule_size, GFP_KERNEL);
  50         if (r == NULL)
  51                 return -ENOMEM;
  52
  53         refcount_set(&r->refcnt, 1);
  54         r->action = FR_ACT_TO_TBL;
  55         r->pref = pref;
  56         r->table = table;
  57         r->flags = flags;
  58         r->proto = RTPROT_KERNEL;
  59         r->fr_net = ops->fro_net;
  60         r->uid_range = fib_kuid_range_unset;
  61
  62         r->suppress_prefixlen = -1;
  63         r->suppress_ifgroup = -1;
  64
  65         /* The lock is not required here, the list in unreacheable
  66          * at the moment this function is called */
  67         list_add_tail(&r->list, &ops->rules_list);
  68         return 0;
  69 }
  70 EXPORT_SYMBOL(fib_default_rule_add);
  71
  72 static u32 fib_default_rule_pref(struct fib_rules_ops *ops)
  73 {
  74         struct list_head *pos;
  75         struct fib_rule *rule;
  76
  77         if (!list_empty(&ops->rules_list)) {
  78                 pos = ops->rules_list.next;
  79                 if (pos->next != &ops->rules_list) {
  80                         rule = list_entry(pos->next, struct fib_rule, list);
  81                         if (rule->pref)
  82                                 return rule->pref - 1;
  83                 }
  84         }
  85
  86         return 0;
  87 }
  88
  89 static void notify_rule_change(int event, struct fib_rule *rule,
  90                                struct fib_rules_ops *ops, struct nlmsghdr *nlh,
  91                                u32 pid);
  92
  93 static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family)
  94 {
  95         struct fib_rules_ops *ops;
  96
  97         rcu_read_lock();
  98         list_for_each_entry_rcu(ops, &net->rules_ops, list) {
  99                 if (ops->family == family) {
 100                         if (!try_module_get(ops->owner))
 101                                 ops = NULL;
 102                         rcu_read_unlock();
 103                         return ops;
 104                 }
 105         }
 106         rcu_read_unlock();
 107
 108         return NULL;
 109 }
 110
 111 static void rules_ops_put(struct fib_rules_ops *ops)
 112 {
 113         if (ops)
 114                 module_put(ops->owner);
 115 }
 116
 117 static void flush_route_cache(struct fib_rules_ops *ops)
 118 {
 119         if (ops->flush_cache)
 120                 ops->flush_cache(ops);
 121 }
 122
 123 static int __fib_rules_register(struct fib_rules_ops *ops)
 124 {
 125         int err = -EEXIST;
 126         struct fib_rules_ops *o;
 127         struct net *net;
 128
 129         net = ops->fro_net;
 130
 131         if (ops->rule_size < sizeof(struct fib_rule))
 132                 return -EINVAL;
 133
 134         if (ops->match == NULL || ops->configure == NULL ||
 135             ops->compare == NULL || ops->fill == NULL ||
 136             ops->action == NULL)
 137                 return -EINVAL;
 138
 139         spin_lock(&net->rules_mod_lock);
 140         list_for_each_entry(o, &net->rules_ops, list)
 141                 if (ops->family == o->family)
 142                         goto errout;
 143
 144         list_add_tail_rcu(&ops->list, &net->rules_ops);
 145         err = 0;
 146 errout:
 147         spin_unlock(&net->rules_mod_lock);
 148
 149         return err;
 150 }
 151
 152 struct fib_rules_ops *
 153 fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net)
 154 {
 155         struct fib_rules_ops *ops;
 156         int err;
 157
 158         ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL);
 159         if (ops == NULL)
 160                 return ERR_PTR(-ENOMEM);
 161
 162         INIT_LIST_HEAD(&ops->rules_list);
 163         ops->fro_net = net;
 164
 165         err = __fib_rules_register(ops);
 166         if (err) {
 167                 kfree(ops);
 168                 ops = ERR_PTR(err);
 169         }
 170
 171         return ops;
 172 }
 173 EXPORT_SYMBOL_GPL(fib_rules_register);
 174
 175 static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
 176 {
 177         struct fib_rule *rule, *tmp;
 178
 179         list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) {
 180                 list_del_rcu(&rule->list);
 181                 if (ops->delete)
 182                         ops->delete(rule);
 183                 fib_rule_put(rule);
 184         }
 185 }
 186
 187 void fib_rules_unregister(struct fib_rules_ops *ops)
 188 {
 189         struct net *net = ops->fro_net;
 190
 191         spin_lock(&net->rules_mod_lock);
 192         list_del_rcu(&ops->list);
 193         spin_unlock(&net->rules_mod_lock);
 194
 195         fib_rules_cleanup_ops(ops);
 196         kfree_rcu(ops, rcu);
 197 }
 198 EXPORT_SYMBOL_GPL(fib_rules_unregister);
 199
 200 static int uid_range_set(struct fib_kuid_range *range)
 201 {
 202         return uid_valid(range->start) && uid_valid(range->end);
 203 }
 204
 205 static struct fib_kuid_range nla_get_kuid_range(struct nlattr **tb)
 206 {
 207         struct fib_rule_uid_range *in;
 208         struct fib_kuid_range out;
 209
 210         in = (struct fib_rule_uid_range *)nla_data(tb[FRA_UID_RANGE]);
 211
 212         out.start = make_kuid(current_user_ns(), in->start);
 213         out.end = make_kuid(current_user_ns(), in->end);
 214
 215         return out;
 216 }
 217
 218 static int nla_put_uid_range(struct sk_buff *skb, struct fib_kuid_range *range)
 219 {
 220         struct fib_rule_uid_range out = {
 221                 from_kuid_munged(current_user_ns(), range->start),
 222                 from_kuid_munged(current_user_ns(), range->end)
 223         };
 224
 225         return nla_put(skb, FRA_UID_RANGE, sizeof(out), &out);
 226 }
 227
 228 static int nla_get_port_range(struct nlattr *pattr,
 229                               struct fib_rule_port_range *port_range)
 230 {
 231         const struct fib_rule_port_range *pr = nla_data(pattr);
 232
 233         if (!fib_rule_port_range_valid(pr))
 234                 return -EINVAL;
 235
 236         port_range->start = pr->start;
 237         port_range->end = pr->end;
 238
 239         return 0;
 240 }
 241
 242 static int nla_put_port_range(struct sk_buff *skb, int attrtype,
 243                               struct fib_rule_port_range *range)
 244 {
 245         return nla_put(skb, attrtype, sizeof(*range), range);
 246 }
 247
 248 static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
 249                           struct flowi *fl, int flags,
 250                           struct fib_lookup_arg *arg)
 251 {
 252         int ret = 0;
 253
 254         if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
 255                 goto out;
 256
 257         if (rule->oifindex && (rule->oifindex != fl->flowi_oif))
 258                 goto out;
 259
 260         if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask)
 261                 goto out;
 262
 263         if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id))
 264                 goto out;
 265
 266         if (rule->l3mdev && !l3mdev_fib_rule_match(rule->fr_net, fl, arg))
 267                 goto out;
 268
 269         if (uid_lt(fl->flowi_uid, rule->uid_range.start) ||
 270             uid_gt(fl->flowi_uid, rule->uid_range.end))
 271                 goto out;
 272
 273         ret = ops->match(rule, fl, flags);
 274 out:
 275         return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
 276 }
 277
 278 int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
 279                      int flags, struct fib_lookup_arg *arg)
 280 {
 281         struct fib_rule *rule;
 282         int err;
 283
 284         rcu_read_lock();
 285
 286         list_for_each_entry_rcu(rule, &ops->rules_list, list) {
 287 jumped:
 288                 if (!fib_rule_match(rule, ops, fl, flags, arg))
 289                         continue;
 290
 291                 if (rule->action == FR_ACT_GOTO) {
 292                         struct fib_rule *target;
 293
 294                         target = rcu_dereference(rule->ctarget);
 295                         if (target == NULL) {
 296                                 continue;
 297                         } else {
 298                                 rule = target;
 299                                 goto jumped;
 300                         }
 301                 } else if (rule->action == FR_ACT_NOP)
 302                         continue;
 303                 else
 304                         err = ops->action(rule, fl, flags, arg);
 305
 306                 if (!err && ops->suppress && ops->suppress(rule, arg))
 307                         continue;
 308
 309                 if (err != -EAGAIN) {
 310                         if ((arg->flags & FIB_LOOKUP_NOREF) ||
 311                             likely(refcount_inc_not_zero(&rule->refcnt))) {
 312                                 arg->rule = rule;
 313                                 goto out;
 314                         }
 315                         break;
 316                 }
 317         }
 318
 319         err = -ESRCH;
 320 out:
 321         rcu_read_unlock();
 322
 323         return err;
 324 }
 325 EXPORT_SYMBOL_GPL(fib_rules_lookup);
 326
 327 static int call_fib_rule_notifier(struct notifier_block *nb, struct net *net,
 328                                   enum fib_event_type event_type,
 329                                   struct fib_rule *rule, int family)
 330 {
 331         struct fib_rule_notifier_info info = {
 332                 .info.family = family,
 333                 .rule = rule,
 334         };
 335
 336         return call_fib_notifier(nb, net, event_type, &info.info);
 337 }
 338
 339 static int call_fib_rule_notifiers(struct net *net,
 340                                    enum fib_event_type event_type,
 341                                    struct fib_rule *rule,
 342                                    struct fib_rules_ops *ops,
 343                                    struct netlink_ext_ack *extack)
 344 {
 345         struct fib_rule_notifier_info info = {
 346                 .info.family = ops->family,
 347                 .info.extack = extack,
 348                 .rule = rule,
 349         };
 350
 351         ops->fib_rules_seq++;
 352         return call_fib_notifiers(net, event_type, &info.info);
 353 }
 354
 355 /* Called with rcu_read_lock() */
 356 int fib_rules_dump(struct net *net, struct notifier_block *nb, int family)
 357 {
 358         struct fib_rules_ops *ops;
 359         struct fib_rule *rule;
 360
 361         ops = lookup_rules_ops(net, family);
 362         if (!ops)
 363                 return -EAFNOSUPPORT;
 364         list_for_each_entry_rcu(rule, &ops->rules_list, list)
 365                 call_fib_rule_notifier(nb, net, FIB_EVENT_RULE_ADD, rule,
 366                                        family);
 367         rules_ops_put(ops);
 368
 369         return 0;
 370 }
 371 EXPORT_SYMBOL_GPL(fib_rules_dump);
 372
 373 unsigned int fib_rules_seq_read(struct net *net, int family)
 374 {
 375         unsigned int fib_rules_seq;
 376         struct fib_rules_ops *ops;
 377
 378         ASSERT_RTNL();
 379
 380         ops = lookup_rules_ops(net, family);
 381         if (!ops)
 382                 return 0;
 383         fib_rules_seq = ops->fib_rules_seq;
 384         rules_ops_put(ops);
 385
 386         return fib_rules_seq;
 387 }
 388 EXPORT_SYMBOL_GPL(fib_rules_seq_read);
 389
 390 static int validate_rulemsg(struct fib_rule_hdr *frh, struct nlattr **tb,
 391                             struct fib_rules_ops *ops)
 392 {
 393         int err = -EINVAL;
 394
 395         if (frh->src_len)
 396                 if (tb[FRA_SRC] == NULL ||
 397                     frh->src_len > (ops->addr_size * 8) ||
 398                     nla_len(tb[FRA_SRC]) != ops->addr_size)
 399                         goto errout;
 400
 401         if (frh->dst_len)
 402                 if (tb[FRA_DST] == NULL ||
 403                     frh->dst_len > (ops->addr_size * 8) ||
 404                     nla_len(tb[FRA_DST]) != ops->addr_size)
 405                         goto errout;
 406
 407         err = 0;
 408 errout:
 409         return err;
 410 }
 411
 412 static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh,
 413                        struct nlattr **tb, struct fib_rule *rule)
 414 {
 415         struct fib_rule *r;
 416
 417         list_for_each_entry(r, &ops->rules_list, list) {
 418                 if (r->action != rule->action)
 419                         continue;
 420
 421                 if (r->table != rule->table)
 422                         continue;
 423
 424                 if (r->pref != rule->pref)
 425                         continue;
 426
 427                 if (memcmp(r->iifname, rule->iifname, IFNAMSIZ))
 428                         continue;
 429
 430                 if (memcmp(r->oifname, rule->oifname, IFNAMSIZ))
 431                         continue;
 432
 433                 if (r->mark != rule->mark)
 434                         continue;
 435
 436                 if (r->mark_mask != rule->mark_mask)
 437                         continue;
 438
 439                 if (r->tun_id != rule->tun_id)
 440                         continue;
 441
 442                 if (r->fr_net != rule->fr_net)
 443                         continue;
 444
 445                 if (r->l3mdev != rule->l3mdev)
 446                         continue;
 447
 448                 if (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
 449                     !uid_eq(r->uid_range.end, rule->uid_range.end))
 450                         continue;
 451
 452                 if (r->ip_proto != rule->ip_proto)
 453                         continue;
 454
 455                 if (!fib_rule_port_range_compare(&r->sport_range,
 456                                                  &rule->sport_range))
 457                         continue;
 458
 459                 if (!fib_rule_port_range_compare(&r->dport_range,
 460                                                  &rule->dport_range))
 461                         continue;
 462
 463                 if (!ops->compare(r, frh, tb))
 464                         continue;
 465                 return 1;
 466         }
 467         return 0;
 468 }
 469
 470 int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh,
 471                    struct netlink_ext_ack *extack)
 472 {
 473         struct net *net = sock_net(skb->sk);
 474         struct fib_rule_hdr *frh = nlmsg_data(nlh);
 475         struct fib_rules_ops *ops = NULL;
 476         struct fib_rule *rule, *r, *last = NULL;
 477         struct nlattr *tb[FRA_MAX+1];
 478         int err = -EINVAL, unresolved = 0;
 479
 480         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
 481                 goto errout;
 482
 483         ops = lookup_rules_ops(net, frh->family);
 484         if (ops == NULL) {
 485                 err = -EAFNOSUPPORT;
 486                 goto errout;
 487         }
 488
 489         err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, extack);
 490         if (err < 0)
 491                 goto errout;
 492
 493         err = validate_rulemsg(frh, tb, ops);
 494         if (err < 0)
 495                 goto errout;
 496
 497         rule = kzalloc(ops->rule_size, GFP_KERNEL);
 498         if (rule == NULL) {
 499                 err = -ENOMEM;
 500                 goto errout;
 501         }
 502         refcount_set(&rule->refcnt, 1);
 503         rule->fr_net = net;
 504
 505         rule->pref = tb[FRA_PRIORITY] ? nla_get_u32(tb[FRA_PRIORITY])
 506                                       : fib_default_rule_pref(ops);
 507
 508         rule->proto = tb[FRA_PROTOCOL] ?
 509                 nla_get_u8(tb[FRA_PROTOCOL]) : RTPROT_UNSPEC;
 510
 511         if (tb[FRA_IIFNAME]) {
 512                 struct net_device *dev;
 513
 514                 rule->iifindex = -1;
 515                 nla_strlcpy(rule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
 516                 dev = __dev_get_by_name(net, rule->iifname);
 517                 if (dev)
 518                         rule->iifindex = dev->ifindex;
 519         }
 520
 521         if (tb[FRA_OIFNAME]) {
 522                 struct net_device *dev;
 523
 524                 rule->oifindex = -1;
 525                 nla_strlcpy(rule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
 526                 dev = __dev_get_by_name(net, rule->oifname);
 527                 if (dev)
 528                         rule->oifindex = dev->ifindex;
 529         }
 530
 531         if (tb[FRA_FWMARK]) {
 532                 rule->mark = nla_get_u32(tb[FRA_FWMARK]);
 533                 if (rule->mark)
 534                         /* compatibility: if the mark value is non-zero all bits
 535                          * are compared unless a mask is explicitly specified.
 536                          */
 537                         rule->mark_mask = 0xFFFFFFFF;
 538         }
 539
 540         if (tb[FRA_FWMASK])
 541                 rule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
 542
 543         if (tb[FRA_TUN_ID])
 544                 rule->tun_id = nla_get_be64(tb[FRA_TUN_ID]);
 545
 546         err = -EINVAL;
 547         if (tb[FRA_L3MDEV]) {
 548 #ifdef CONFIG_NET_L3_MASTER_DEV
 549                 rule->l3mdev = nla_get_u8(tb[FRA_L3MDEV]);
 550                 if (rule->l3mdev != 1)
 551 #endif
 552                         goto errout_free;
 553         }
 554
 555         rule->action = frh->action;
 556         rule->flags = frh->flags;
 557         rule->table = frh_get_table(frh, tb);
 558         if (tb[FRA_SUPPRESS_PREFIXLEN])
 559                 rule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
 560         else
 561                 rule->suppress_prefixlen = -1;
 562
 563         if (tb[FRA_SUPPRESS_IFGROUP])
 564                 rule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]);
 565         else
 566                 rule->suppress_ifgroup = -1;
 567
 568         if (tb[FRA_GOTO]) {
 569                 if (rule->action != FR_ACT_GOTO)
 570                         goto errout_free;
 571
 572                 rule->target = nla_get_u32(tb[FRA_GOTO]);
 573                 /* Backward jumps are prohibited to avoid endless loops */
 574                 if (rule->target <= rule->pref)
 575                         goto errout_free;
 576
 577                 list_for_each_entry(r, &ops->rules_list, list) {
 578                         if (r->pref == rule->target) {
 579                                 RCU_INIT_POINTER(rule->ctarget, r);
 580                                 break;
 581                         }
 582                 }
 583
 584                 if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
 585                         unresolved = 1;
 586         } else if (rule->action == FR_ACT_GOTO)
 587                 goto errout_free;
 588
 589         if (rule->l3mdev && rule->table)
 590                 goto errout_free;
 591
 592         if (tb[FRA_UID_RANGE]) {
 593                 if (current_user_ns() != net->user_ns) {
 594                         err = -EPERM;
 595                         goto errout_free;
 596                 }
 597
 598                 rule->uid_range = nla_get_kuid_range(tb);
 599
 600                 if (!uid_range_set(&rule->uid_range) ||
 601                     !uid_lte(rule->uid_range.start, rule->uid_range.end))
 602                         goto errout_free;
 603         } else {
 604                 rule->uid_range = fib_kuid_range_unset;
 605         }
 606
 607         if (tb[FRA_IP_PROTO])
 608                 rule->ip_proto = nla_get_u8(tb[FRA_IP_PROTO]);
 609
 610         if (tb[FRA_SPORT_RANGE]) {
 611                 err = nla_get_port_range(tb[FRA_SPORT_RANGE],
 612                                          &rule->sport_range);
 613                 if (err)
 614                         goto errout_free;
 615         }
 616
 617         if (tb[FRA_DPORT_RANGE]) {
 618                 err = nla_get_port_range(tb[FRA_DPORT_RANGE],
 619                                          &rule->dport_range);
 620                 if (err)
 621                         goto errout_free;
 622         }
 623
 624         if ((nlh->nlmsg_flags & NLM_F_EXCL) &&
 625             rule_exists(ops, frh, tb, rule)) {
 626                 err = -EEXIST;
 627                 goto errout_free;
 628         }
 629
 630         err = ops->configure(rule, skb, frh, tb);
 631         if (err < 0)
 632                 goto errout_free;
 633
 634         err = call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops,
 635                                       extack);
 636         if (err < 0)
 637                 goto errout_free;
 638
 639         list_for_each_entry(r, &ops->rules_list, list) {
 640                 if (r->pref > rule->pref)
 641                         break;
 642                 last = r;
 643         }
 644
 645         if (last)
 646                 list_add_rcu(&rule->list, &last->list);
 647         else
 648                 list_add_rcu(&rule->list, &ops->rules_list);
 649
 650         if (ops->unresolved_rules) {
 651                 /*
 652                  * There are unresolved goto rules in the list, check if
 653                  * any of them are pointing to this new rule.
 654                  */
 655                 list_for_each_entry(r, &ops->rules_list, list) {
 656                         if (r->action == FR_ACT_GOTO &&
 657                             r->target == rule->pref &&
 658                             rtnl_dereference(r->ctarget) == NULL) {
 659                                 rcu_assign_pointer(r->ctarget, rule);
 660                                 if (--ops->unresolved_rules == 0)
 661                                         break;
 662                         }
 663                 }
 664         }
 665
 666         if (rule->action == FR_ACT_GOTO)
 667                 ops->nr_goto_rules++;
 668
 669         if (unresolved)
 670                 ops->unresolved_rules++;
 671
 672         if (rule->tun_id)
 673                 ip_tunnel_need_metadata();
 674
 675         notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
 676         flush_route_cache(ops);
 677         rules_ops_put(ops);
 678         return 0;
 679
 680 errout_free:
 681         kfree(rule);
 682 errout:
 683         rules_ops_put(ops);
 684         return err;
 685 }
 686 EXPORT_SYMBOL_GPL(fib_nl_newrule);
 687
 688 int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh,
 689                    struct netlink_ext_ack *extack)
 690 {
 691         struct net *net = sock_net(skb->sk);
 692         struct fib_rule_hdr *frh = nlmsg_data(nlh);
 693         struct fib_rule_port_range sprange = {0, 0};
 694         struct fib_rule_port_range dprange = {0, 0};
 695         struct fib_rules_ops *ops = NULL;
 696         struct fib_rule *rule, *r;
 697         struct nlattr *tb[FRA_MAX+1];
 698         struct fib_kuid_range range;
 699         int err = -EINVAL;
 700
 701         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
 702                 goto errout;
 703
 704         ops = lookup_rules_ops(net, frh->family);
 705         if (ops == NULL) {
 706                 err = -EAFNOSUPPORT;
 707                 goto errout;
 708         }
 709
 710         err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, extack);
 711         if (err < 0)
 712                 goto errout;
 713
 714         err = validate_rulemsg(frh, tb, ops);
 715         if (err < 0)
 716                 goto errout;
 717
 718         if (tb[FRA_UID_RANGE]) {
 719                 range = nla_get_kuid_range(tb);
 720                 if (!uid_range_set(&range)) {
 721                         err = -EINVAL;
 722                         goto errout;
 723                 }
 724         } else {
 725                 range = fib_kuid_range_unset;
 726         }
 727
 728         if (tb[FRA_SPORT_RANGE]) {
 729                 err = nla_get_port_range(tb[FRA_SPORT_RANGE],
 730                                          &sprange);
 731                 if (err)
 732                         goto errout;
 733         }
 734
 735         if (tb[FRA_DPORT_RANGE]) {
 736                 err = nla_get_port_range(tb[FRA_DPORT_RANGE],
 737                                          &dprange);
 738                 if (err)
 739                         goto errout;
 740         }
 741
 742         list_for_each_entry(rule, &ops->rules_list, list) {
 743                 if (tb[FRA_PROTOCOL] &&
 744                     (rule->proto != nla_get_u8(tb[FRA_PROTOCOL])))
 745                         continue;
 746
 747                 if (frh->action && (frh->action != rule->action))
 748                         continue;
 749
 750                 if (frh_get_table(frh, tb) &&
 751                     (frh_get_table(frh, tb) != rule->table))
 752                         continue;
 753
 754                 if (tb[FRA_PRIORITY] &&
 755                     (rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
 756                         continue;
 757
 758                 if (tb[FRA_IIFNAME] &&
 759                     nla_strcmp(tb[FRA_IIFNAME], rule->iifname))
 760                         continue;
 761
 762                 if (tb[FRA_OIFNAME] &&
 763                     nla_strcmp(tb[FRA_OIFNAME], rule->oifname))
 764                         continue;
 765
 766                 if (tb[FRA_FWMARK] &&
 767                     (rule->mark != nla_get_u32(tb[FRA_FWMARK])))
 768                         continue;
 769
 770                 if (tb[FRA_FWMASK] &&
 771                     (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK])))
 772                         continue;
 773
 774                 if (tb[FRA_TUN_ID] &&
 775                     (rule->tun_id != nla_get_be64(tb[FRA_TUN_ID])))
 776                         continue;
 777
 778                 if (tb[FRA_L3MDEV] &&
 779                     (rule->l3mdev != nla_get_u8(tb[FRA_L3MDEV])))
 780                         continue;
 781
 782                 if (uid_range_set(&range) &&
 783                     (!uid_eq(rule->uid_range.start, range.start) ||
 784                      !uid_eq(rule->uid_range.end, range.end)))
 785                         continue;
 786
 787                 if (tb[FRA_IP_PROTO] &&
 788                     (rule->ip_proto != nla_get_u8(tb[FRA_IP_PROTO])))
 789                         continue;
 790
 791                 if (fib_rule_port_range_set(&sprange) &&
 792                     !fib_rule_port_range_compare(&rule->sport_range, &sprange))
 793                         continue;
 794
 795                 if (fib_rule_port_range_set(&dprange) &&
 796                     !fib_rule_port_range_compare(&rule->dport_range, &dprange))
 797                         continue;
 798
 799                 if (!ops->compare(rule, frh, tb))
 800                         continue;
 801
 802                 if (rule->flags & FIB_RULE_PERMANENT) {
 803                         err = -EPERM;
 804                         goto errout;
 805                 }
 806
 807                 if (ops->delete) {
 808                         err = ops->delete(rule);
 809                         if (err)
 810                                 goto errout;
 811                 }
 812
 813                 if (rule->tun_id)
 814                         ip_tunnel_unneed_metadata();
 815
 816                 list_del_rcu(&rule->list);
 817
 818                 if (rule->action == FR_ACT_GOTO) {
 819                         ops->nr_goto_rules--;
 820                         if (rtnl_dereference(rule->ctarget) == NULL)
 821                                 ops->unresolved_rules--;
 822                 }
 823
 824                 /*
 825                  * Check if this rule is a target to any of them. If so,
 826                  * adjust to the next one with the same preference or
 827                  * disable them. As this operation is eventually very
 828                  * expensive, it is only performed if goto rules, except
 829                  * current if it is goto rule, have actually been added.
 830                  */
 831                 if (ops->nr_goto_rules > 0) {
 832                         struct fib_rule *n;
 833
 834                         n = list_next_entry(rule, list);
 835                         if (&n->list == &ops->rules_list || n->pref != rule->pref)
 836                                 n = NULL;
 837                         list_for_each_entry(r, &ops->rules_list, list) {
 838                                 if (rtnl_dereference(r->ctarget) != rule)
 839                                         continue;
 840                                 rcu_assign_pointer(r->ctarget, n);
 841                                 if (!n)
 842                                         ops->unresolved_rules++;
 843                         }
 844                 }
 845
 846                 call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops,
 847                                         NULL);
 848                 notify_rule_change(RTM_DELRULE, rule, ops, nlh,
 849                                    NETLINK_CB(skb).portid);
 850                 fib_rule_put(rule);
 851                 flush_route_cache(ops);
 852                 rules_ops_put(ops);
 853                 return 0;
 854         }
 855
 856         err = -ENOENT;
 857 errout:
 858         rules_ops_put(ops);
 859         return err;
 860 }
 861 EXPORT_SYMBOL_GPL(fib_nl_delrule);
 862
 863 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
 864                                          struct fib_rule *rule)
 865 {
 866         size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
 867                          + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
 868                          + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
 869                          + nla_total_size(4) /* FRA_PRIORITY */
 870                          + nla_total_size(4) /* FRA_TABLE */
 871                          + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */
 872                          + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */
 873                          + nla_total_size(4) /* FRA_FWMARK */
 874                          + nla_total_size(4) /* FRA_FWMASK */
 875                          + nla_total_size_64bit(8) /* FRA_TUN_ID */
 876                          + nla_total_size(sizeof(struct fib_kuid_range))
 877                          + nla_total_size(1) /* FRA_PROTOCOL */
 878                          + nla_total_size(1) /* FRA_IP_PROTO */
 879                          + nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_SPORT_RANGE */
 880                          + nla_total_size(sizeof(struct fib_rule_port_range)); /* FRA_DPORT_RANGE */
 881
 882         if (ops->nlmsg_payload)
 883                 payload += ops->nlmsg_payload(rule);
 884
 885         return payload;
 886 }
 887
 888 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
 889                             u32 pid, u32 seq, int type, int flags,
 890                             struct fib_rules_ops *ops)
 891 {
 892         struct nlmsghdr *nlh;
 893         struct fib_rule_hdr *frh;
 894
 895         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
 896         if (nlh == NULL)
 897                 return -EMSGSIZE;
 898
 899         frh = nlmsg_data(nlh);
 900         frh->family = ops->family;
 901         frh->table = rule->table;
 902         if (nla_put_u32(skb, FRA_TABLE, rule->table))
 903                 goto nla_put_failure;
 904         if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen))
 905                 goto nla_put_failure;
 906         frh->res1 = 0;
 907         frh->res2 = 0;
 908         frh->action = rule->action;
 909         frh->flags = rule->flags;
 910
 911         if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto))
 912                 goto nla_put_failure;
 913
 914         if (rule->action == FR_ACT_GOTO &&
 915             rcu_access_pointer(rule->ctarget) == NULL)
 916                 frh->flags |= FIB_RULE_UNRESOLVED;
 917
 918         if (rule->iifname[0]) {
 919                 if (nla_put_string(skb, FRA_IIFNAME, rule->iifname))
 920                         goto nla_put_failure;
 921                 if (rule->iifindex == -1)
 922                         frh->flags |= FIB_RULE_IIF_DETACHED;
 923         }
 924
 925         if (rule->oifname[0]) {
 926                 if (nla_put_string(skb, FRA_OIFNAME, rule->oifname))
 927                         goto nla_put_failure;
 928                 if (rule->oifindex == -1)
 929                         frh->flags |= FIB_RULE_OIF_DETACHED;
 930         }
 931
 932         if ((rule->pref &&
 933              nla_put_u32(skb, FRA_PRIORITY, rule->pref)) ||
 934             (rule->mark &&
 935              nla_put_u32(skb, FRA_FWMARK, rule->mark)) ||
 936             ((rule->mark_mask || rule->mark) &&
 937              nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) ||
 938             (rule->target &&
 939              nla_put_u32(skb, FRA_GOTO, rule->target)) ||
 940             (rule->tun_id &&
 941              nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) ||
 942             (rule->l3mdev &&
 943              nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) ||
 944             (uid_range_set(&rule->uid_range) &&
 945              nla_put_uid_range(skb, &rule->uid_range)) ||
 946             (fib_rule_port_range_set(&rule->sport_range) &&
 947              nla_put_port_range(skb, FRA_SPORT_RANGE, &rule->sport_range)) ||
 948             (fib_rule_port_range_set(&rule->dport_range) &&
 949              nla_put_port_range(skb, FRA_DPORT_RANGE, &rule->dport_range)) ||
 950             (rule->ip_proto && nla_put_u8(skb, FRA_IP_PROTO, rule->ip_proto)))
 951                 goto nla_put_failure;
 952
 953         if (rule->suppress_ifgroup != -1) {
 954                 if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup))
 955                         goto nla_put_failure;
 956         }
 957
 958         if (ops->fill(rule, skb, frh) < 0)
 959                 goto nla_put_failure;
 960
 961         nlmsg_end(skb, nlh);
 962         return 0;
 963
 964 nla_put_failure:
 965         nlmsg_cancel(skb, nlh);
 966         return -EMSGSIZE;
 967 }
 968
 969 static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
 970                       struct fib_rules_ops *ops)
 971 {
 972         int idx = 0;
 973         struct fib_rule *rule;
 974         int err = 0;
 975
 976         rcu_read_lock();
 977         list_for_each_entry_rcu(rule, &ops->rules_list, list) {
 978                 if (idx < cb->args[1])
 979                         goto skip;
 980
 981                 err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
 982                                        cb->nlh->nlmsg_seq, RTM_NEWRULE,
 983                                        NLM_F_MULTI, ops);
 984                 if (err)
 985                         break;
 986 skip:
 987                 idx++;
 988         }
 989         rcu_read_unlock();
 990         cb->args[1] = idx;
 991         rules_ops_put(ops);
 992
 993         return err;
 994 }
 995
 996 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
 997 {
 998         struct net *net = sock_net(skb->sk);
 999         struct fib_rules_ops *ops;
1000         int idx = 0, family;
1001
1002         family = rtnl_msg_family(cb->nlh);
1003         if (family != AF_UNSPEC) {
1004                 /* Protocol specific dump request */
1005                 ops = lookup_rules_ops(net, family);
1006                 if (ops == NULL)
1007                         return -EAFNOSUPPORT;
1008
1009                 dump_rules(skb, cb, ops);
1010
1011                 return skb->len;
1012         }
1013
1014         rcu_read_lock();
1015         list_for_each_entry_rcu(ops, &net->rules_ops, list) {
1016                 if (idx < cb->args[0] || !try_module_get(ops->owner))
1017                         goto skip;
1018
1019                 if (dump_rules(skb, cb, ops) < 0)
1020                         break;
1021
1022                 cb->args[1] = 0;
1023 skip:
1024                 idx++;
1025         }
1026         rcu_read_unlock();
1027         cb->args[0] = idx;
1028
1029         return skb->len;
1030 }
1031
1032 static void notify_rule_change(int event, struct fib_rule *rule,
1033                                struct fib_rules_ops *ops, struct nlmsghdr *nlh,
1034                                u32 pid)
1035 {
1036         struct net *net;
1037         struct sk_buff *skb;
1038         int err = -ENOBUFS;
1039
1040         net = ops->fro_net;
1041         skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
1042         if (skb == NULL)
1043                 goto errout;
1044
1045         err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
1046         if (err < 0) {
1047                 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
1048                 WARN_ON(err == -EMSGSIZE);
1049                 kfree_skb(skb);
1050                 goto errout;
1051         }
1052
1053         rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
1054         return;
1055 errout:
1056         if (err < 0)
1057                 rtnl_set_sk_err(net, ops->nlgroup, err);
1058 }
1059
1060 static void attach_rules(struct list_head *rules, struct net_device *dev)
1061 {
1062         struct fib_rule *rule;
1063
1064         list_for_each_entry(rule, rules, list) {
1065                 if (rule->iifindex == -1 &&
1066                     strcmp(dev->name, rule->iifname) == 0)
1067                         rule->iifindex = dev->ifindex;
1068                 if (rule->oifindex == -1 &&
1069                     strcmp(dev->name, rule->oifname) == 0)
1070                         rule->oifindex = dev->ifindex;
1071         }
1072 }
1073
1074 static void detach_rules(struct list_head *rules, struct net_device *dev)
1075 {
1076         struct fib_rule *rule;
1077
1078         list_for_each_entry(rule, rules, list) {
1079                 if (rule->iifindex == dev->ifindex)
1080                         rule->iifindex = -1;
1081                 if (rule->oifindex == dev->ifindex)
1082                         rule->oifindex = -1;
1083         }
1084 }
1085
1086
1087 static int fib_rules_event(struct notifier_block *this, unsigned long event,
1088                            void *ptr)
1089 {
1090         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1091         struct net *net = dev_net(dev);
1092         struct fib_rules_ops *ops;
1093
1094         ASSERT_RTNL();
1095
1096         switch (event) {
1097         case NETDEV_REGISTER:
1098                 list_for_each_entry(ops, &net->rules_ops, list)
1099                         attach_rules(&ops->rules_list, dev);
1100                 break;
1101
1102         case NETDEV_CHANGENAME:
1103                 list_for_each_entry(ops, &net->rules_ops, list) {
1104                         detach_rules(&ops->rules_list, dev);
1105                         attach_rules(&ops->rules_list, dev);
1106                 }
1107                 break;
1108
1109         case NETDEV_UNREGISTER:
1110                 list_for_each_entry(ops, &net->rules_ops, list)
1111                         detach_rules(&ops->rules_list, dev);
1112                 break;
1113         }
1114
1115         return NOTIFY_DONE;
1116 }
1117
1118 static struct notifier_block fib_rules_notifier = {
1119         .notifier_call = fib_rules_event,
1120 };
1121
1122 static int __net_init fib_rules_net_init(struct net *net)
1123 {
1124         INIT_LIST_HEAD(&net->rules_ops);
1125         spin_lock_init(&net->rules_mod_lock);
1126         return 0;
1127 }
1128
1129 static void __net_exit fib_rules_net_exit(struct net *net)
1130 {
1131         WARN_ON_ONCE(!list_empty(&net->rules_ops));
1132 }
1133
1134 static struct pernet_operations fib_rules_net_ops = {
1135         .init = fib_rules_net_init,
1136         .exit = fib_rules_net_exit,
1137 };
1138
1139 static int __init fib_rules_init(void)
1140 {
1141         int err;
1142         rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, 0);
1143         rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, 0);
1144         rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, 0);
1145
1146         err = register_pernet_subsys(&fib_rules_net_ops);
1147         if (err < 0)
1148                 goto fail;
1149
1150         err = register_netdevice_notifier(&fib_rules_notifier);
1151         if (err < 0)
1152                 goto fail_unregister;
1153
1154         return 0;
1155
1156 fail_unregister:
1157         unregister_pernet_subsys(&fib_rules_net_ops);
1158 fail:
1159         rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
1160         rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
1161         rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
1162         return err;
1163 }
1164
1165 subsys_initcall(fib_rules_init);