1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * net/core/fib_rules.c Generic Routing Rules 4 * 5 * Authors: Thomas Graf <tgraf@suug.ch> 6 */ 7 8 #include <linux/types.h> 9 #include <linux/kernel.h> 10 #include <linux/slab.h> 11 #include <linux/list.h> 12 #include <linux/module.h> 13 #include <net/net_namespace.h> 14 #include <net/sock.h> 15 #include <net/fib_rules.h> 16 #include <net/ip_tunnels.h> 17 18 static const struct fib_kuid_range fib_kuid_range_unset = { 19 KUIDT_INIT(0), 20 KUIDT_INIT(~0), 21 }; 22 23 bool fib_rule_matchall(const struct fib_rule *rule) 24 { 25 if (rule->iifindex || rule->oifindex || rule->mark || rule->tun_id || 26 rule->flags) 27 return false; 28 if (rule->suppress_ifgroup != -1 || rule->suppress_prefixlen != -1) 29 return false; 30 if (!uid_eq(rule->uid_range.start, fib_kuid_range_unset.start) || 31 !uid_eq(rule->uid_range.end, fib_kuid_range_unset.end)) 32 return false; 33 if (fib_rule_port_range_set(&rule->sport_range)) 34 return false; 35 if (fib_rule_port_range_set(&rule->dport_range)) 36 return false; 37 return true; 38 } 39 EXPORT_SYMBOL_GPL(fib_rule_matchall); 40 41 int fib_default_rule_add(struct fib_rules_ops *ops, 42 u32 pref, u32 table, u32 flags) 43 { 44 struct fib_rule *r; 45 46 r = kzalloc(ops->rule_size, GFP_KERNEL); 47 if (r == NULL) 48 return -ENOMEM; 49 50 refcount_set(&r->refcnt, 1); 51 r->action = FR_ACT_TO_TBL; 52 r->pref = pref; 53 r->table = table; 54 r->flags = flags; 55 r->proto = RTPROT_KERNEL; 56 r->fr_net = ops->fro_net; 57 r->uid_range = fib_kuid_range_unset; 58 59 r->suppress_prefixlen = -1; 60 r->suppress_ifgroup = -1; 61 62 /* The lock is not required here, the list in unreacheable 63 * at the moment this function is called */ 64 list_add_tail(&r->list, &ops->rules_list); 65 return 0; 66 } 67 EXPORT_SYMBOL(fib_default_rule_add); 68 69 static u32 fib_default_rule_pref(struct fib_rules_ops *ops) 70 { 71 struct list_head *pos; 72 struct fib_rule *rule; 73 74 if (!list_empty(&ops->rules_list)) { 75 pos = ops->rules_list.next; 76 if (pos->next != &ops->rules_list) { 77 rule = list_entry(pos->next, struct fib_rule, list); 78 if (rule->pref) 79 return rule->pref - 1; 80 } 81 } 82 83 return 0; 84 } 85 86 static void notify_rule_change(int event, struct fib_rule *rule, 87 struct fib_rules_ops *ops, struct nlmsghdr *nlh, 88 u32 pid); 89 90 static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family) 91 { 92 struct fib_rules_ops *ops; 93 94 rcu_read_lock(); 95 list_for_each_entry_rcu(ops, &net->rules_ops, list) { 96 if (ops->family == family) { 97 if (!try_module_get(ops->owner)) 98 ops = NULL; 99 rcu_read_unlock(); 100 return ops; 101 } 102 } 103 rcu_read_unlock(); 104 105 return NULL; 106 } 107 108 static void rules_ops_put(struct fib_rules_ops *ops) 109 { 110 if (ops) 111 module_put(ops->owner); 112 } 113 114 static void flush_route_cache(struct fib_rules_ops *ops) 115 { 116 if (ops->flush_cache) 117 ops->flush_cache(ops); 118 } 119 120 static int __fib_rules_register(struct fib_rules_ops *ops) 121 { 122 int err = -EEXIST; 123 struct fib_rules_ops *o; 124 struct net *net; 125 126 net = ops->fro_net; 127 128 if (ops->rule_size < sizeof(struct fib_rule)) 129 return -EINVAL; 130 131 if (ops->match == NULL || ops->configure == NULL || 132 ops->compare == NULL || ops->fill == NULL || 133 ops->action == NULL) 134 return -EINVAL; 135 136 spin_lock(&net->rules_mod_lock); 137 list_for_each_entry(o, &net->rules_ops, list) 138 if (ops->family == o->family) 139 goto errout; 140 141 list_add_tail_rcu(&ops->list, &net->rules_ops); 142 err = 0; 143 errout: 144 spin_unlock(&net->rules_mod_lock); 145 146 return err; 147 } 148 149 struct fib_rules_ops * 150 fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net) 151 { 152 struct fib_rules_ops *ops; 153 int err; 154 155 ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL); 156 if (ops == NULL) 157 return ERR_PTR(-ENOMEM); 158 159 INIT_LIST_HEAD(&ops->rules_list); 160 ops->fro_net = net; 161 162 err = __fib_rules_register(ops); 163 if (err) { 164 kfree(ops); 165 ops = ERR_PTR(err); 166 } 167 168 return ops; 169 } 170 EXPORT_SYMBOL_GPL(fib_rules_register); 171 172 static void fib_rules_cleanup_ops(struct fib_rules_ops *ops) 173 { 174 struct fib_rule *rule, *tmp; 175 176 list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) { 177 list_del_rcu(&rule->list); 178 if (ops->delete) 179 ops->delete(rule); 180 fib_rule_put(rule); 181 } 182 } 183 184 void fib_rules_unregister(struct fib_rules_ops *ops) 185 { 186 struct net *net = ops->fro_net; 187 188 spin_lock(&net->rules_mod_lock); 189 list_del_rcu(&ops->list); 190 spin_unlock(&net->rules_mod_lock); 191 192 fib_rules_cleanup_ops(ops); 193 kfree_rcu(ops, rcu); 194 } 195 EXPORT_SYMBOL_GPL(fib_rules_unregister); 196 197 static int uid_range_set(struct fib_kuid_range *range) 198 { 199 return uid_valid(range->start) && uid_valid(range->end); 200 } 201 202 static struct fib_kuid_range nla_get_kuid_range(struct nlattr **tb) 203 { 204 struct fib_rule_uid_range *in; 205 struct fib_kuid_range out; 206 207 in = (struct fib_rule_uid_range *)nla_data(tb[FRA_UID_RANGE]); 208 209 out.start = make_kuid(current_user_ns(), in->start); 210 out.end = make_kuid(current_user_ns(), in->end); 211 212 return out; 213 } 214 215 static int nla_put_uid_range(struct sk_buff *skb, struct fib_kuid_range *range) 216 { 217 struct fib_rule_uid_range out = { 218 from_kuid_munged(current_user_ns(), range->start), 219 from_kuid_munged(current_user_ns(), range->end) 220 }; 221 222 return nla_put(skb, FRA_UID_RANGE, sizeof(out), &out); 223 } 224 225 static int nla_get_port_range(struct nlattr *pattr, 226 struct fib_rule_port_range *port_range) 227 { 228 const struct fib_rule_port_range *pr = nla_data(pattr); 229 230 if (!fib_rule_port_range_valid(pr)) 231 return -EINVAL; 232 233 port_range->start = pr->start; 234 port_range->end = pr->end; 235 236 return 0; 237 } 238 239 static int nla_put_port_range(struct sk_buff *skb, int attrtype, 240 struct fib_rule_port_range *range) 241 { 242 return nla_put(skb, attrtype, sizeof(*range), range); 243 } 244 245 static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops, 246 struct flowi *fl, int flags, 247 struct fib_lookup_arg *arg) 248 { 249 int ret = 0; 250 251 if (rule->iifindex && (rule->iifindex != fl->flowi_iif)) 252 goto out; 253 254 if (rule->oifindex && (rule->oifindex != fl->flowi_oif)) 255 goto out; 256 257 if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask) 258 goto out; 259 260 if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id)) 261 goto out; 262 263 if (rule->l3mdev && !l3mdev_fib_rule_match(rule->fr_net, fl, arg)) 264 goto out; 265 266 if (uid_lt(fl->flowi_uid, rule->uid_range.start) || 267 uid_gt(fl->flowi_uid, rule->uid_range.end)) 268 goto out; 269 270 ret = ops->match(rule, fl, flags); 271 out: 272 return (rule->flags & FIB_RULE_INVERT) ? !ret : ret; 273 } 274 275 int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl, 276 int flags, struct fib_lookup_arg *arg) 277 { 278 struct fib_rule *rule; 279 int err; 280 281 rcu_read_lock(); 282 283 list_for_each_entry_rcu(rule, &ops->rules_list, list) { 284 jumped: 285 if (!fib_rule_match(rule, ops, fl, flags, arg)) 286 continue; 287 288 if (rule->action == FR_ACT_GOTO) { 289 struct fib_rule *target; 290 291 target = rcu_dereference(rule->ctarget); 292 if (target == NULL) { 293 continue; 294 } else { 295 rule = target; 296 goto jumped; 297 } 298 } else if (rule->action == FR_ACT_NOP) 299 continue; 300 else 301 err = ops->action(rule, fl, flags, arg); 302 303 if (!err && ops->suppress && ops->suppress(rule, arg)) 304 continue; 305 306 if (err != -EAGAIN) { 307 if ((arg->flags & FIB_LOOKUP_NOREF) || 308 likely(refcount_inc_not_zero(&rule->refcnt))) { 309 arg->rule = rule; 310 goto out; 311 } 312 break; 313 } 314 } 315 316 err = -ESRCH; 317 out: 318 rcu_read_unlock(); 319 320 return err; 321 } 322 EXPORT_SYMBOL_GPL(fib_rules_lookup); 323 324 static int call_fib_rule_notifier(struct notifier_block *nb, struct net *net, 325 enum fib_event_type event_type, 326 struct fib_rule *rule, int family) 327 { 328 struct fib_rule_notifier_info info = { 329 .info.family = family, 330 .rule = rule, 331 }; 332 333 return call_fib_notifier(nb, net, event_type, &info.info); 334 } 335 336 static int call_fib_rule_notifiers(struct net *net, 337 enum fib_event_type event_type, 338 struct fib_rule *rule, 339 struct fib_rules_ops *ops, 340 struct netlink_ext_ack *extack) 341 { 342 struct fib_rule_notifier_info info = { 343 .info.family = ops->family, 344 .info.extack = extack, 345 .rule = rule, 346 }; 347 348 ops->fib_rules_seq++; 349 return call_fib_notifiers(net, event_type, &info.info); 350 } 351 352 /* Called with rcu_read_lock() */ 353 int fib_rules_dump(struct net *net, struct notifier_block *nb, int family) 354 { 355 struct fib_rules_ops *ops; 356 struct fib_rule *rule; 357 358 ops = lookup_rules_ops(net, family); 359 if (!ops) 360 return -EAFNOSUPPORT; 361 list_for_each_entry_rcu(rule, &ops->rules_list, list) 362 call_fib_rule_notifier(nb, net, FIB_EVENT_RULE_ADD, rule, 363 family); 364 rules_ops_put(ops); 365 366 return 0; 367 } 368 EXPORT_SYMBOL_GPL(fib_rules_dump); 369 370 unsigned int fib_rules_seq_read(struct net *net, int family) 371 { 372 unsigned int fib_rules_seq; 373 struct fib_rules_ops *ops; 374 375 ASSERT_RTNL(); 376 377 ops = lookup_rules_ops(net, family); 378 if (!ops) 379 return 0; 380 fib_rules_seq = ops->fib_rules_seq; 381 rules_ops_put(ops); 382 383 return fib_rules_seq; 384 } 385 EXPORT_SYMBOL_GPL(fib_rules_seq_read); 386 387 static struct fib_rule *rule_find(struct fib_rules_ops *ops, 388 struct fib_rule_hdr *frh, 389 struct nlattr **tb, 390 struct fib_rule *rule, 391 bool user_priority) 392 { 393 struct fib_rule *r; 394 395 list_for_each_entry(r, &ops->rules_list, list) { 396 if (rule->action && r->action != rule->action) 397 continue; 398 399 if (rule->table && r->table != rule->table) 400 continue; 401 402 if (user_priority && r->pref != rule->pref) 403 continue; 404 405 if (rule->iifname[0] && 406 memcmp(r->iifname, rule->iifname, IFNAMSIZ)) 407 continue; 408 409 if (rule->oifname[0] && 410 memcmp(r->oifname, rule->oifname, IFNAMSIZ)) 411 continue; 412 413 if (rule->mark && r->mark != rule->mark) 414 continue; 415 416 if (rule->suppress_ifgroup != -1 && 417 r->suppress_ifgroup != rule->suppress_ifgroup) 418 continue; 419 420 if (rule->suppress_prefixlen != -1 && 421 r->suppress_prefixlen != rule->suppress_prefixlen) 422 continue; 423 424 if (rule->mark_mask && r->mark_mask != rule->mark_mask) 425 continue; 426 427 if (rule->tun_id && r->tun_id != rule->tun_id) 428 continue; 429 430 if (r->fr_net != rule->fr_net) 431 continue; 432 433 if (rule->l3mdev && r->l3mdev != rule->l3mdev) 434 continue; 435 436 if (uid_range_set(&rule->uid_range) && 437 (!uid_eq(r->uid_range.start, rule->uid_range.start) || 438 !uid_eq(r->uid_range.end, rule->uid_range.end))) 439 continue; 440 441 if (rule->ip_proto && r->ip_proto != rule->ip_proto) 442 continue; 443 444 if (rule->proto && r->proto != rule->proto) 445 continue; 446 447 if (fib_rule_port_range_set(&rule->sport_range) && 448 !fib_rule_port_range_compare(&r->sport_range, 449 &rule->sport_range)) 450 continue; 451 452 if (fib_rule_port_range_set(&rule->dport_range) && 453 !fib_rule_port_range_compare(&r->dport_range, 454 &rule->dport_range)) 455 continue; 456 457 if (!ops->compare(r, frh, tb)) 458 continue; 459 return r; 460 } 461 462 return NULL; 463 } 464 465 #ifdef CONFIG_NET_L3_MASTER_DEV 466 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule, 467 struct netlink_ext_ack *extack) 468 { 469 nlrule->l3mdev = nla_get_u8(nla); 470 if (nlrule->l3mdev != 1) { 471 NL_SET_ERR_MSG(extack, "Invalid l3mdev attribute"); 472 return -1; 473 } 474 475 return 0; 476 } 477 #else 478 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule, 479 struct netlink_ext_ack *extack) 480 { 481 NL_SET_ERR_MSG(extack, "l3mdev support is not enabled in kernel"); 482 return -1; 483 } 484 #endif 485 486 static int fib_nl2rule(struct sk_buff *skb, struct nlmsghdr *nlh, 487 struct netlink_ext_ack *extack, 488 struct fib_rules_ops *ops, 489 struct nlattr *tb[], 490 struct fib_rule **rule, 491 bool *user_priority) 492 { 493 struct net *net = sock_net(skb->sk); 494 struct fib_rule_hdr *frh = nlmsg_data(nlh); 495 struct fib_rule *nlrule = NULL; 496 int err = -EINVAL; 497 498 if (frh->src_len) 499 if (!tb[FRA_SRC] || 500 frh->src_len > (ops->addr_size * 8) || 501 nla_len(tb[FRA_SRC]) != ops->addr_size) { 502 NL_SET_ERR_MSG(extack, "Invalid source address"); 503 goto errout; 504 } 505 506 if (frh->dst_len) 507 if (!tb[FRA_DST] || 508 frh->dst_len > (ops->addr_size * 8) || 509 nla_len(tb[FRA_DST]) != ops->addr_size) { 510 NL_SET_ERR_MSG(extack, "Invalid dst address"); 511 goto errout; 512 } 513 514 nlrule = kzalloc(ops->rule_size, GFP_KERNEL); 515 if (!nlrule) { 516 err = -ENOMEM; 517 goto errout; 518 } 519 refcount_set(&nlrule->refcnt, 1); 520 nlrule->fr_net = net; 521 522 if (tb[FRA_PRIORITY]) { 523 nlrule->pref = nla_get_u32(tb[FRA_PRIORITY]); 524 *user_priority = true; 525 } else { 526 nlrule->pref = fib_default_rule_pref(ops); 527 } 528 529 nlrule->proto = tb[FRA_PROTOCOL] ? 530 nla_get_u8(tb[FRA_PROTOCOL]) : RTPROT_UNSPEC; 531 532 if (tb[FRA_IIFNAME]) { 533 struct net_device *dev; 534 535 nlrule->iifindex = -1; 536 nla_strlcpy(nlrule->iifname, tb[FRA_IIFNAME], IFNAMSIZ); 537 dev = __dev_get_by_name(net, nlrule->iifname); 538 if (dev) 539 nlrule->iifindex = dev->ifindex; 540 } 541 542 if (tb[FRA_OIFNAME]) { 543 struct net_device *dev; 544 545 nlrule->oifindex = -1; 546 nla_strlcpy(nlrule->oifname, tb[FRA_OIFNAME], IFNAMSIZ); 547 dev = __dev_get_by_name(net, nlrule->oifname); 548 if (dev) 549 nlrule->oifindex = dev->ifindex; 550 } 551 552 if (tb[FRA_FWMARK]) { 553 nlrule->mark = nla_get_u32(tb[FRA_FWMARK]); 554 if (nlrule->mark) 555 /* compatibility: if the mark value is non-zero all bits 556 * are compared unless a mask is explicitly specified. 557 */ 558 nlrule->mark_mask = 0xFFFFFFFF; 559 } 560 561 if (tb[FRA_FWMASK]) 562 nlrule->mark_mask = nla_get_u32(tb[FRA_FWMASK]); 563 564 if (tb[FRA_TUN_ID]) 565 nlrule->tun_id = nla_get_be64(tb[FRA_TUN_ID]); 566 567 err = -EINVAL; 568 if (tb[FRA_L3MDEV] && 569 fib_nl2rule_l3mdev(tb[FRA_L3MDEV], nlrule, extack) < 0) 570 goto errout_free; 571 572 nlrule->action = frh->action; 573 nlrule->flags = frh->flags; 574 nlrule->table = frh_get_table(frh, tb); 575 if (tb[FRA_SUPPRESS_PREFIXLEN]) 576 nlrule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]); 577 else 578 nlrule->suppress_prefixlen = -1; 579 580 if (tb[FRA_SUPPRESS_IFGROUP]) 581 nlrule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]); 582 else 583 nlrule->suppress_ifgroup = -1; 584 585 if (tb[FRA_GOTO]) { 586 if (nlrule->action != FR_ACT_GOTO) { 587 NL_SET_ERR_MSG(extack, "Unexpected goto"); 588 goto errout_free; 589 } 590 591 nlrule->target = nla_get_u32(tb[FRA_GOTO]); 592 /* Backward jumps are prohibited to avoid endless loops */ 593 if (nlrule->target <= nlrule->pref) { 594 NL_SET_ERR_MSG(extack, "Backward goto not supported"); 595 goto errout_free; 596 } 597 } else if (nlrule->action == FR_ACT_GOTO) { 598 NL_SET_ERR_MSG(extack, "Missing goto target for action goto"); 599 goto errout_free; 600 } 601 602 if (nlrule->l3mdev && nlrule->table) { 603 NL_SET_ERR_MSG(extack, "l3mdev and table are mutually exclusive"); 604 goto errout_free; 605 } 606 607 if (tb[FRA_UID_RANGE]) { 608 if (current_user_ns() != net->user_ns) { 609 err = -EPERM; 610 NL_SET_ERR_MSG(extack, "No permission to set uid"); 611 goto errout_free; 612 } 613 614 nlrule->uid_range = nla_get_kuid_range(tb); 615 616 if (!uid_range_set(&nlrule->uid_range) || 617 !uid_lte(nlrule->uid_range.start, nlrule->uid_range.end)) { 618 NL_SET_ERR_MSG(extack, "Invalid uid range"); 619 goto errout_free; 620 } 621 } else { 622 nlrule->uid_range = fib_kuid_range_unset; 623 } 624 625 if (tb[FRA_IP_PROTO]) 626 nlrule->ip_proto = nla_get_u8(tb[FRA_IP_PROTO]); 627 628 if (tb[FRA_SPORT_RANGE]) { 629 err = nla_get_port_range(tb[FRA_SPORT_RANGE], 630 &nlrule->sport_range); 631 if (err) { 632 NL_SET_ERR_MSG(extack, "Invalid sport range"); 633 goto errout_free; 634 } 635 } 636 637 if (tb[FRA_DPORT_RANGE]) { 638 err = nla_get_port_range(tb[FRA_DPORT_RANGE], 639 &nlrule->dport_range); 640 if (err) { 641 NL_SET_ERR_MSG(extack, "Invalid dport range"); 642 goto errout_free; 643 } 644 } 645 646 *rule = nlrule; 647 648 return 0; 649 650 errout_free: 651 kfree(nlrule); 652 errout: 653 return err; 654 } 655 656 static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh, 657 struct nlattr **tb, struct fib_rule *rule) 658 { 659 struct fib_rule *r; 660 661 list_for_each_entry(r, &ops->rules_list, list) { 662 if (r->action != rule->action) 663 continue; 664 665 if (r->table != rule->table) 666 continue; 667 668 if (r->pref != rule->pref) 669 continue; 670 671 if (memcmp(r->iifname, rule->iifname, IFNAMSIZ)) 672 continue; 673 674 if (memcmp(r->oifname, rule->oifname, IFNAMSIZ)) 675 continue; 676 677 if (r->mark != rule->mark) 678 continue; 679 680 if (r->suppress_ifgroup != rule->suppress_ifgroup) 681 continue; 682 683 if (r->suppress_prefixlen != rule->suppress_prefixlen) 684 continue; 685 686 if (r->mark_mask != rule->mark_mask) 687 continue; 688 689 if (r->tun_id != rule->tun_id) 690 continue; 691 692 if (r->fr_net != rule->fr_net) 693 continue; 694 695 if (r->l3mdev != rule->l3mdev) 696 continue; 697 698 if (!uid_eq(r->uid_range.start, rule->uid_range.start) || 699 !uid_eq(r->uid_range.end, rule->uid_range.end)) 700 continue; 701 702 if (r->ip_proto != rule->ip_proto) 703 continue; 704 705 if (r->proto != rule->proto) 706 continue; 707 708 if (!fib_rule_port_range_compare(&r->sport_range, 709 &rule->sport_range)) 710 continue; 711 712 if (!fib_rule_port_range_compare(&r->dport_range, 713 &rule->dport_range)) 714 continue; 715 716 if (!ops->compare(r, frh, tb)) 717 continue; 718 return 1; 719 } 720 return 0; 721 } 722 723 int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh, 724 struct netlink_ext_ack *extack) 725 { 726 struct net *net = sock_net(skb->sk); 727 struct fib_rule_hdr *frh = nlmsg_data(nlh); 728 struct fib_rules_ops *ops = NULL; 729 struct fib_rule *rule = NULL, *r, *last = NULL; 730 struct nlattr *tb[FRA_MAX + 1]; 731 int err = -EINVAL, unresolved = 0; 732 bool user_priority = false; 733 734 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { 735 NL_SET_ERR_MSG(extack, "Invalid msg length"); 736 goto errout; 737 } 738 739 ops = lookup_rules_ops(net, frh->family); 740 if (!ops) { 741 err = -EAFNOSUPPORT; 742 NL_SET_ERR_MSG(extack, "Rule family not supported"); 743 goto errout; 744 } 745 746 err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX, 747 ops->policy, extack); 748 if (err < 0) { 749 NL_SET_ERR_MSG(extack, "Error parsing msg"); 750 goto errout; 751 } 752 753 err = fib_nl2rule(skb, nlh, extack, ops, tb, &rule, &user_priority); 754 if (err) 755 goto errout; 756 757 if (rule_exists(ops, frh, tb, rule)) { 758 if (nlh->nlmsg_flags & NLM_F_EXCL) 759 err = -EEXIST; 760 goto errout_free; 761 } 762 763 err = ops->configure(rule, skb, frh, tb, extack); 764 if (err < 0) 765 goto errout_free; 766 767 err = call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops, 768 extack); 769 if (err < 0) 770 goto errout_free; 771 772 list_for_each_entry(r, &ops->rules_list, list) { 773 if (r->pref == rule->target) { 774 RCU_INIT_POINTER(rule->ctarget, r); 775 break; 776 } 777 } 778 779 if (rcu_dereference_protected(rule->ctarget, 1) == NULL) 780 unresolved = 1; 781 782 list_for_each_entry(r, &ops->rules_list, list) { 783 if (r->pref > rule->pref) 784 break; 785 last = r; 786 } 787 788 if (last) 789 list_add_rcu(&rule->list, &last->list); 790 else 791 list_add_rcu(&rule->list, &ops->rules_list); 792 793 if (ops->unresolved_rules) { 794 /* 795 * There are unresolved goto rules in the list, check if 796 * any of them are pointing to this new rule. 797 */ 798 list_for_each_entry(r, &ops->rules_list, list) { 799 if (r->action == FR_ACT_GOTO && 800 r->target == rule->pref && 801 rtnl_dereference(r->ctarget) == NULL) { 802 rcu_assign_pointer(r->ctarget, rule); 803 if (--ops->unresolved_rules == 0) 804 break; 805 } 806 } 807 } 808 809 if (rule->action == FR_ACT_GOTO) 810 ops->nr_goto_rules++; 811 812 if (unresolved) 813 ops->unresolved_rules++; 814 815 if (rule->tun_id) 816 ip_tunnel_need_metadata(); 817 818 notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid); 819 flush_route_cache(ops); 820 rules_ops_put(ops); 821 return 0; 822 823 errout_free: 824 kfree(rule); 825 errout: 826 rules_ops_put(ops); 827 return err; 828 } 829 EXPORT_SYMBOL_GPL(fib_nl_newrule); 830 831 int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh, 832 struct netlink_ext_ack *extack) 833 { 834 struct net *net = sock_net(skb->sk); 835 struct fib_rule_hdr *frh = nlmsg_data(nlh); 836 struct fib_rules_ops *ops = NULL; 837 struct fib_rule *rule = NULL, *r, *nlrule = NULL; 838 struct nlattr *tb[FRA_MAX+1]; 839 int err = -EINVAL; 840 bool user_priority = false; 841 842 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { 843 NL_SET_ERR_MSG(extack, "Invalid msg length"); 844 goto errout; 845 } 846 847 ops = lookup_rules_ops(net, frh->family); 848 if (ops == NULL) { 849 err = -EAFNOSUPPORT; 850 NL_SET_ERR_MSG(extack, "Rule family not supported"); 851 goto errout; 852 } 853 854 err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX, 855 ops->policy, extack); 856 if (err < 0) { 857 NL_SET_ERR_MSG(extack, "Error parsing msg"); 858 goto errout; 859 } 860 861 err = fib_nl2rule(skb, nlh, extack, ops, tb, &nlrule, &user_priority); 862 if (err) 863 goto errout; 864 865 rule = rule_find(ops, frh, tb, nlrule, user_priority); 866 if (!rule) { 867 err = -ENOENT; 868 goto errout; 869 } 870 871 if (rule->flags & FIB_RULE_PERMANENT) { 872 err = -EPERM; 873 goto errout; 874 } 875 876 if (ops->delete) { 877 err = ops->delete(rule); 878 if (err) 879 goto errout; 880 } 881 882 if (rule->tun_id) 883 ip_tunnel_unneed_metadata(); 884 885 list_del_rcu(&rule->list); 886 887 if (rule->action == FR_ACT_GOTO) { 888 ops->nr_goto_rules--; 889 if (rtnl_dereference(rule->ctarget) == NULL) 890 ops->unresolved_rules--; 891 } 892 893 /* 894 * Check if this rule is a target to any of them. If so, 895 * adjust to the next one with the same preference or 896 * disable them. As this operation is eventually very 897 * expensive, it is only performed if goto rules, except 898 * current if it is goto rule, have actually been added. 899 */ 900 if (ops->nr_goto_rules > 0) { 901 struct fib_rule *n; 902 903 n = list_next_entry(rule, list); 904 if (&n->list == &ops->rules_list || n->pref != rule->pref) 905 n = NULL; 906 list_for_each_entry(r, &ops->rules_list, list) { 907 if (rtnl_dereference(r->ctarget) != rule) 908 continue; 909 rcu_assign_pointer(r->ctarget, n); 910 if (!n) 911 ops->unresolved_rules++; 912 } 913 } 914 915 call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops, 916 NULL); 917 notify_rule_change(RTM_DELRULE, rule, ops, nlh, 918 NETLINK_CB(skb).portid); 919 fib_rule_put(rule); 920 flush_route_cache(ops); 921 rules_ops_put(ops); 922 kfree(nlrule); 923 return 0; 924 925 errout: 926 kfree(nlrule); 927 rules_ops_put(ops); 928 return err; 929 } 930 EXPORT_SYMBOL_GPL(fib_nl_delrule); 931 932 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops, 933 struct fib_rule *rule) 934 { 935 size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr)) 936 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */ 937 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */ 938 + nla_total_size(4) /* FRA_PRIORITY */ 939 + nla_total_size(4) /* FRA_TABLE */ 940 + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */ 941 + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */ 942 + nla_total_size(4) /* FRA_FWMARK */ 943 + nla_total_size(4) /* FRA_FWMASK */ 944 + nla_total_size_64bit(8) /* FRA_TUN_ID */ 945 + nla_total_size(sizeof(struct fib_kuid_range)) 946 + nla_total_size(1) /* FRA_PROTOCOL */ 947 + nla_total_size(1) /* FRA_IP_PROTO */ 948 + nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_SPORT_RANGE */ 949 + nla_total_size(sizeof(struct fib_rule_port_range)); /* FRA_DPORT_RANGE */ 950 951 if (ops->nlmsg_payload) 952 payload += ops->nlmsg_payload(rule); 953 954 return payload; 955 } 956 957 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule, 958 u32 pid, u32 seq, int type, int flags, 959 struct fib_rules_ops *ops) 960 { 961 struct nlmsghdr *nlh; 962 struct fib_rule_hdr *frh; 963 964 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags); 965 if (nlh == NULL) 966 return -EMSGSIZE; 967 968 frh = nlmsg_data(nlh); 969 frh->family = ops->family; 970 frh->table = rule->table; 971 if (nla_put_u32(skb, FRA_TABLE, rule->table)) 972 goto nla_put_failure; 973 if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen)) 974 goto nla_put_failure; 975 frh->res1 = 0; 976 frh->res2 = 0; 977 frh->action = rule->action; 978 frh->flags = rule->flags; 979 980 if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto)) 981 goto nla_put_failure; 982 983 if (rule->action == FR_ACT_GOTO && 984 rcu_access_pointer(rule->ctarget) == NULL) 985 frh->flags |= FIB_RULE_UNRESOLVED; 986 987 if (rule->iifname[0]) { 988 if (nla_put_string(skb, FRA_IIFNAME, rule->iifname)) 989 goto nla_put_failure; 990 if (rule->iifindex == -1) 991 frh->flags |= FIB_RULE_IIF_DETACHED; 992 } 993 994 if (rule->oifname[0]) { 995 if (nla_put_string(skb, FRA_OIFNAME, rule->oifname)) 996 goto nla_put_failure; 997 if (rule->oifindex == -1) 998 frh->flags |= FIB_RULE_OIF_DETACHED; 999 } 1000 1001 if ((rule->pref && 1002 nla_put_u32(skb, FRA_PRIORITY, rule->pref)) || 1003 (rule->mark && 1004 nla_put_u32(skb, FRA_FWMARK, rule->mark)) || 1005 ((rule->mark_mask || rule->mark) && 1006 nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) || 1007 (rule->target && 1008 nla_put_u32(skb, FRA_GOTO, rule->target)) || 1009 (rule->tun_id && 1010 nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) || 1011 (rule->l3mdev && 1012 nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) || 1013 (uid_range_set(&rule->uid_range) && 1014 nla_put_uid_range(skb, &rule->uid_range)) || 1015 (fib_rule_port_range_set(&rule->sport_range) && 1016 nla_put_port_range(skb, FRA_SPORT_RANGE, &rule->sport_range)) || 1017 (fib_rule_port_range_set(&rule->dport_range) && 1018 nla_put_port_range(skb, FRA_DPORT_RANGE, &rule->dport_range)) || 1019 (rule->ip_proto && nla_put_u8(skb, FRA_IP_PROTO, rule->ip_proto))) 1020 goto nla_put_failure; 1021 1022 if (rule->suppress_ifgroup != -1) { 1023 if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup)) 1024 goto nla_put_failure; 1025 } 1026 1027 if (ops->fill(rule, skb, frh) < 0) 1028 goto nla_put_failure; 1029 1030 nlmsg_end(skb, nlh); 1031 return 0; 1032 1033 nla_put_failure: 1034 nlmsg_cancel(skb, nlh); 1035 return -EMSGSIZE; 1036 } 1037 1038 static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb, 1039 struct fib_rules_ops *ops) 1040 { 1041 int idx = 0; 1042 struct fib_rule *rule; 1043 int err = 0; 1044 1045 rcu_read_lock(); 1046 list_for_each_entry_rcu(rule, &ops->rules_list, list) { 1047 if (idx < cb->args[1]) 1048 goto skip; 1049 1050 err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid, 1051 cb->nlh->nlmsg_seq, RTM_NEWRULE, 1052 NLM_F_MULTI, ops); 1053 if (err) 1054 break; 1055 skip: 1056 idx++; 1057 } 1058 rcu_read_unlock(); 1059 cb->args[1] = idx; 1060 rules_ops_put(ops); 1061 1062 return err; 1063 } 1064 1065 static int fib_valid_dumprule_req(const struct nlmsghdr *nlh, 1066 struct netlink_ext_ack *extack) 1067 { 1068 struct fib_rule_hdr *frh; 1069 1070 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { 1071 NL_SET_ERR_MSG(extack, "Invalid header for fib rule dump request"); 1072 return -EINVAL; 1073 } 1074 1075 frh = nlmsg_data(nlh); 1076 if (frh->dst_len || frh->src_len || frh->tos || frh->table || 1077 frh->res1 || frh->res2 || frh->action || frh->flags) { 1078 NL_SET_ERR_MSG(extack, 1079 "Invalid values in header for fib rule dump request"); 1080 return -EINVAL; 1081 } 1082 1083 if (nlmsg_attrlen(nlh, sizeof(*frh))) { 1084 NL_SET_ERR_MSG(extack, "Invalid data after header in fib rule dump request"); 1085 return -EINVAL; 1086 } 1087 1088 return 0; 1089 } 1090 1091 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb) 1092 { 1093 const struct nlmsghdr *nlh = cb->nlh; 1094 struct net *net = sock_net(skb->sk); 1095 struct fib_rules_ops *ops; 1096 int idx = 0, family; 1097 1098 if (cb->strict_check) { 1099 int err = fib_valid_dumprule_req(nlh, cb->extack); 1100 1101 if (err < 0) 1102 return err; 1103 } 1104 1105 family = rtnl_msg_family(nlh); 1106 if (family != AF_UNSPEC) { 1107 /* Protocol specific dump request */ 1108 ops = lookup_rules_ops(net, family); 1109 if (ops == NULL) 1110 return -EAFNOSUPPORT; 1111 1112 dump_rules(skb, cb, ops); 1113 1114 return skb->len; 1115 } 1116 1117 rcu_read_lock(); 1118 list_for_each_entry_rcu(ops, &net->rules_ops, list) { 1119 if (idx < cb->args[0] || !try_module_get(ops->owner)) 1120 goto skip; 1121 1122 if (dump_rules(skb, cb, ops) < 0) 1123 break; 1124 1125 cb->args[1] = 0; 1126 skip: 1127 idx++; 1128 } 1129 rcu_read_unlock(); 1130 cb->args[0] = idx; 1131 1132 return skb->len; 1133 } 1134 1135 static void notify_rule_change(int event, struct fib_rule *rule, 1136 struct fib_rules_ops *ops, struct nlmsghdr *nlh, 1137 u32 pid) 1138 { 1139 struct net *net; 1140 struct sk_buff *skb; 1141 int err = -ENOBUFS; 1142 1143 net = ops->fro_net; 1144 skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL); 1145 if (skb == NULL) 1146 goto errout; 1147 1148 err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops); 1149 if (err < 0) { 1150 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */ 1151 WARN_ON(err == -EMSGSIZE); 1152 kfree_skb(skb); 1153 goto errout; 1154 } 1155 1156 rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL); 1157 return; 1158 errout: 1159 if (err < 0) 1160 rtnl_set_sk_err(net, ops->nlgroup, err); 1161 } 1162 1163 static void attach_rules(struct list_head *rules, struct net_device *dev) 1164 { 1165 struct fib_rule *rule; 1166 1167 list_for_each_entry(rule, rules, list) { 1168 if (rule->iifindex == -1 && 1169 strcmp(dev->name, rule->iifname) == 0) 1170 rule->iifindex = dev->ifindex; 1171 if (rule->oifindex == -1 && 1172 strcmp(dev->name, rule->oifname) == 0) 1173 rule->oifindex = dev->ifindex; 1174 } 1175 } 1176 1177 static void detach_rules(struct list_head *rules, struct net_device *dev) 1178 { 1179 struct fib_rule *rule; 1180 1181 list_for_each_entry(rule, rules, list) { 1182 if (rule->iifindex == dev->ifindex) 1183 rule->iifindex = -1; 1184 if (rule->oifindex == dev->ifindex) 1185 rule->oifindex = -1; 1186 } 1187 } 1188 1189 1190 static int fib_rules_event(struct notifier_block *this, unsigned long event, 1191 void *ptr) 1192 { 1193 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1194 struct net *net = dev_net(dev); 1195 struct fib_rules_ops *ops; 1196 1197 ASSERT_RTNL(); 1198 1199 switch (event) { 1200 case NETDEV_REGISTER: 1201 list_for_each_entry(ops, &net->rules_ops, list) 1202 attach_rules(&ops->rules_list, dev); 1203 break; 1204 1205 case NETDEV_CHANGENAME: 1206 list_for_each_entry(ops, &net->rules_ops, list) { 1207 detach_rules(&ops->rules_list, dev); 1208 attach_rules(&ops->rules_list, dev); 1209 } 1210 break; 1211 1212 case NETDEV_UNREGISTER: 1213 list_for_each_entry(ops, &net->rules_ops, list) 1214 detach_rules(&ops->rules_list, dev); 1215 break; 1216 } 1217 1218 return NOTIFY_DONE; 1219 } 1220 1221 static struct notifier_block fib_rules_notifier = { 1222 .notifier_call = fib_rules_event, 1223 }; 1224 1225 static int __net_init fib_rules_net_init(struct net *net) 1226 { 1227 INIT_LIST_HEAD(&net->rules_ops); 1228 spin_lock_init(&net->rules_mod_lock); 1229 return 0; 1230 } 1231 1232 static void __net_exit fib_rules_net_exit(struct net *net) 1233 { 1234 WARN_ON_ONCE(!list_empty(&net->rules_ops)); 1235 } 1236 1237 static struct pernet_operations fib_rules_net_ops = { 1238 .init = fib_rules_net_init, 1239 .exit = fib_rules_net_exit, 1240 }; 1241 1242 static int __init fib_rules_init(void) 1243 { 1244 int err; 1245 rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, 0); 1246 rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, 0); 1247 rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, 0); 1248 1249 err = register_pernet_subsys(&fib_rules_net_ops); 1250 if (err < 0) 1251 goto fail; 1252 1253 err = register_netdevice_notifier(&fib_rules_notifier); 1254 if (err < 0) 1255 goto fail_unregister; 1256 1257 return 0; 1258 1259 fail_unregister: 1260 unregister_pernet_subsys(&fib_rules_net_ops); 1261 fail: 1262 rtnl_unregister(PF_UNSPEC, RTM_NEWRULE); 1263 rtnl_unregister(PF_UNSPEC, RTM_DELRULE); 1264 rtnl_unregister(PF_UNSPEC, RTM_GETRULE); 1265 return err; 1266 } 1267 1268 subsys_initcall(fib_rules_init); 1269