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); 1166