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, 325 enum fib_event_type event_type, 326 struct fib_rule *rule, int family, 327 struct netlink_ext_ack *extack) 328 { 329 struct fib_rule_notifier_info info = { 330 .info.family = family, 331 .info.extack = extack, 332 .rule = rule, 333 }; 334 335 return call_fib_notifier(nb, event_type, &info.info); 336 } 337 338 static int call_fib_rule_notifiers(struct net *net, 339 enum fib_event_type event_type, 340 struct fib_rule *rule, 341 struct fib_rules_ops *ops, 342 struct netlink_ext_ack *extack) 343 { 344 struct fib_rule_notifier_info info = { 345 .info.family = ops->family, 346 .info.extack = extack, 347 .rule = rule, 348 }; 349 350 ops->fib_rules_seq++; 351 return call_fib_notifiers(net, event_type, &info.info); 352 } 353 354 /* Called with rcu_read_lock() */ 355 int fib_rules_dump(struct net *net, struct notifier_block *nb, int family, 356 struct netlink_ext_ack *extack) 357 { 358 struct fib_rules_ops *ops; 359 struct fib_rule *rule; 360 int err = 0; 361 362 ops = lookup_rules_ops(net, family); 363 if (!ops) 364 return -EAFNOSUPPORT; 365 list_for_each_entry_rcu(rule, &ops->rules_list, list) { 366 err = call_fib_rule_notifier(nb, FIB_EVENT_RULE_ADD, 367 rule, family, extack); 368 if (err) 369 break; 370 } 371 rules_ops_put(ops); 372 373 return err; 374 } 375 EXPORT_SYMBOL_GPL(fib_rules_dump); 376 377 unsigned int fib_rules_seq_read(struct net *net, int family) 378 { 379 unsigned int fib_rules_seq; 380 struct fib_rules_ops *ops; 381 382 ASSERT_RTNL(); 383 384 ops = lookup_rules_ops(net, family); 385 if (!ops) 386 return 0; 387 fib_rules_seq = ops->fib_rules_seq; 388 rules_ops_put(ops); 389 390 return fib_rules_seq; 391 } 392 EXPORT_SYMBOL_GPL(fib_rules_seq_read); 393 394 static struct fib_rule *rule_find(struct fib_rules_ops *ops, 395 struct fib_rule_hdr *frh, 396 struct nlattr **tb, 397 struct fib_rule *rule, 398 bool user_priority) 399 { 400 struct fib_rule *r; 401 402 list_for_each_entry(r, &ops->rules_list, list) { 403 if (rule->action && r->action != rule->action) 404 continue; 405 406 if (rule->table && r->table != rule->table) 407 continue; 408 409 if (user_priority && r->pref != rule->pref) 410 continue; 411 412 if (rule->iifname[0] && 413 memcmp(r->iifname, rule->iifname, IFNAMSIZ)) 414 continue; 415 416 if (rule->oifname[0] && 417 memcmp(r->oifname, rule->oifname, IFNAMSIZ)) 418 continue; 419 420 if (rule->mark && r->mark != rule->mark) 421 continue; 422 423 if (rule->suppress_ifgroup != -1 && 424 r->suppress_ifgroup != rule->suppress_ifgroup) 425 continue; 426 427 if (rule->suppress_prefixlen != -1 && 428 r->suppress_prefixlen != rule->suppress_prefixlen) 429 continue; 430 431 if (rule->mark_mask && r->mark_mask != rule->mark_mask) 432 continue; 433 434 if (rule->tun_id && r->tun_id != rule->tun_id) 435 continue; 436 437 if (r->fr_net != rule->fr_net) 438 continue; 439 440 if (rule->l3mdev && r->l3mdev != rule->l3mdev) 441 continue; 442 443 if (uid_range_set(&rule->uid_range) && 444 (!uid_eq(r->uid_range.start, rule->uid_range.start) || 445 !uid_eq(r->uid_range.end, rule->uid_range.end))) 446 continue; 447 448 if (rule->ip_proto && r->ip_proto != rule->ip_proto) 449 continue; 450 451 if (rule->proto && r->proto != rule->proto) 452 continue; 453 454 if (fib_rule_port_range_set(&rule->sport_range) && 455 !fib_rule_port_range_compare(&r->sport_range, 456 &rule->sport_range)) 457 continue; 458 459 if (fib_rule_port_range_set(&rule->dport_range) && 460 !fib_rule_port_range_compare(&r->dport_range, 461 &rule->dport_range)) 462 continue; 463 464 if (!ops->compare(r, frh, tb)) 465 continue; 466 return r; 467 } 468 469 return NULL; 470 } 471 472 #ifdef CONFIG_NET_L3_MASTER_DEV 473 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule, 474 struct netlink_ext_ack *extack) 475 { 476 nlrule->l3mdev = nla_get_u8(nla); 477 if (nlrule->l3mdev != 1) { 478 NL_SET_ERR_MSG(extack, "Invalid l3mdev attribute"); 479 return -1; 480 } 481 482 return 0; 483 } 484 #else 485 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule, 486 struct netlink_ext_ack *extack) 487 { 488 NL_SET_ERR_MSG(extack, "l3mdev support is not enabled in kernel"); 489 return -1; 490 } 491 #endif 492 493 static int fib_nl2rule(struct sk_buff *skb, struct nlmsghdr *nlh, 494 struct netlink_ext_ack *extack, 495 struct fib_rules_ops *ops, 496 struct nlattr *tb[], 497 struct fib_rule **rule, 498 bool *user_priority) 499 { 500 struct net *net = sock_net(skb->sk); 501 struct fib_rule_hdr *frh = nlmsg_data(nlh); 502 struct fib_rule *nlrule = NULL; 503 int err = -EINVAL; 504 505 if (frh->src_len) 506 if (!tb[FRA_SRC] || 507 frh->src_len > (ops->addr_size * 8) || 508 nla_len(tb[FRA_SRC]) != ops->addr_size) { 509 NL_SET_ERR_MSG(extack, "Invalid source address"); 510 goto errout; 511 } 512 513 if (frh->dst_len) 514 if (!tb[FRA_DST] || 515 frh->dst_len > (ops->addr_size * 8) || 516 nla_len(tb[FRA_DST]) != ops->addr_size) { 517 NL_SET_ERR_MSG(extack, "Invalid dst address"); 518 goto errout; 519 } 520 521 nlrule = kzalloc(ops->rule_size, GFP_KERNEL); 522 if (!nlrule) { 523 err = -ENOMEM; 524 goto errout; 525 } 526 refcount_set(&nlrule->refcnt, 1); 527 nlrule->fr_net = net; 528 529 if (tb[FRA_PRIORITY]) { 530 nlrule->pref = nla_get_u32(tb[FRA_PRIORITY]); 531 *user_priority = true; 532 } else { 533 nlrule->pref = fib_default_rule_pref(ops); 534 } 535 536 nlrule->proto = tb[FRA_PROTOCOL] ? 537 nla_get_u8(tb[FRA_PROTOCOL]) : RTPROT_UNSPEC; 538 539 if (tb[FRA_IIFNAME]) { 540 struct net_device *dev; 541 542 nlrule->iifindex = -1; 543 nla_strlcpy(nlrule->iifname, tb[FRA_IIFNAME], IFNAMSIZ); 544 dev = __dev_get_by_name(net, nlrule->iifname); 545 if (dev) 546 nlrule->iifindex = dev->ifindex; 547 } 548 549 if (tb[FRA_OIFNAME]) { 550 struct net_device *dev; 551 552 nlrule->oifindex = -1; 553 nla_strlcpy(nlrule->oifname, tb[FRA_OIFNAME], IFNAMSIZ); 554 dev = __dev_get_by_name(net, nlrule->oifname); 555 if (dev) 556 nlrule->oifindex = dev->ifindex; 557 } 558 559 if (tb[FRA_FWMARK]) { 560 nlrule->mark = nla_get_u32(tb[FRA_FWMARK]); 561 if (nlrule->mark) 562 /* compatibility: if the mark value is non-zero all bits 563 * are compared unless a mask is explicitly specified. 564 */ 565 nlrule->mark_mask = 0xFFFFFFFF; 566 } 567 568 if (tb[FRA_FWMASK]) 569 nlrule->mark_mask = nla_get_u32(tb[FRA_FWMASK]); 570 571 if (tb[FRA_TUN_ID]) 572 nlrule->tun_id = nla_get_be64(tb[FRA_TUN_ID]); 573 574 err = -EINVAL; 575 if (tb[FRA_L3MDEV] && 576 fib_nl2rule_l3mdev(tb[FRA_L3MDEV], nlrule, extack) < 0) 577 goto errout_free; 578 579 nlrule->action = frh->action; 580 nlrule->flags = frh->flags; 581 nlrule->table = frh_get_table(frh, tb); 582 if (tb[FRA_SUPPRESS_PREFIXLEN]) 583 nlrule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]); 584 else 585 nlrule->suppress_prefixlen = -1; 586 587 if (tb[FRA_SUPPRESS_IFGROUP]) 588 nlrule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]); 589 else 590 nlrule->suppress_ifgroup = -1; 591 592 if (tb[FRA_GOTO]) { 593 if (nlrule->action != FR_ACT_GOTO) { 594 NL_SET_ERR_MSG(extack, "Unexpected goto"); 595 goto errout_free; 596 } 597 598 nlrule->target = nla_get_u32(tb[FRA_GOTO]); 599 /* Backward jumps are prohibited to avoid endless loops */ 600 if (nlrule->target <= nlrule->pref) { 601 NL_SET_ERR_MSG(extack, "Backward goto not supported"); 602 goto errout_free; 603 } 604 } else if (nlrule->action == FR_ACT_GOTO) { 605 NL_SET_ERR_MSG(extack, "Missing goto target for action goto"); 606 goto errout_free; 607 } 608 609 if (nlrule->l3mdev && nlrule->table) { 610 NL_SET_ERR_MSG(extack, "l3mdev and table are mutually exclusive"); 611 goto errout_free; 612 } 613 614 if (tb[FRA_UID_RANGE]) { 615 if (current_user_ns() != net->user_ns) { 616 err = -EPERM; 617 NL_SET_ERR_MSG(extack, "No permission to set uid"); 618 goto errout_free; 619 } 620 621 nlrule->uid_range = nla_get_kuid_range(tb); 622 623 if (!uid_range_set(&nlrule->uid_range) || 624 !uid_lte(nlrule->uid_range.start, nlrule->uid_range.end)) { 625 NL_SET_ERR_MSG(extack, "Invalid uid range"); 626 goto errout_free; 627 } 628 } else { 629 nlrule->uid_range = fib_kuid_range_unset; 630 } 631 632 if (tb[FRA_IP_PROTO]) 633 nlrule->ip_proto = nla_get_u8(tb[FRA_IP_PROTO]); 634 635 if (tb[FRA_SPORT_RANGE]) { 636 err = nla_get_port_range(tb[FRA_SPORT_RANGE], 637 &nlrule->sport_range); 638 if (err) { 639 NL_SET_ERR_MSG(extack, "Invalid sport range"); 640 goto errout_free; 641 } 642 } 643 644 if (tb[FRA_DPORT_RANGE]) { 645 err = nla_get_port_range(tb[FRA_DPORT_RANGE], 646 &nlrule->dport_range); 647 if (err) { 648 NL_SET_ERR_MSG(extack, "Invalid dport range"); 649 goto errout_free; 650 } 651 } 652 653 *rule = nlrule; 654 655 return 0; 656 657 errout_free: 658 kfree(nlrule); 659 errout: 660 return err; 661 } 662 663 static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh, 664 struct nlattr **tb, struct fib_rule *rule) 665 { 666 struct fib_rule *r; 667 668 list_for_each_entry(r, &ops->rules_list, list) { 669 if (r->action != rule->action) 670 continue; 671 672 if (r->table != rule->table) 673 continue; 674 675 if (r->pref != rule->pref) 676 continue; 677 678 if (memcmp(r->iifname, rule->iifname, IFNAMSIZ)) 679 continue; 680 681 if (memcmp(r->oifname, rule->oifname, IFNAMSIZ)) 682 continue; 683 684 if (r->mark != rule->mark) 685 continue; 686 687 if (r->suppress_ifgroup != rule->suppress_ifgroup) 688 continue; 689 690 if (r->suppress_prefixlen != rule->suppress_prefixlen) 691 continue; 692 693 if (r->mark_mask != rule->mark_mask) 694 continue; 695 696 if (r->tun_id != rule->tun_id) 697 continue; 698 699 if (r->fr_net != rule->fr_net) 700 continue; 701 702 if (r->l3mdev != rule->l3mdev) 703 continue; 704 705 if (!uid_eq(r->uid_range.start, rule->uid_range.start) || 706 !uid_eq(r->uid_range.end, rule->uid_range.end)) 707 continue; 708 709 if (r->ip_proto != rule->ip_proto) 710 continue; 711 712 if (r->proto != rule->proto) 713 continue; 714 715 if (!fib_rule_port_range_compare(&r->sport_range, 716 &rule->sport_range)) 717 continue; 718 719 if (!fib_rule_port_range_compare(&r->dport_range, 720 &rule->dport_range)) 721 continue; 722 723 if (!ops->compare(r, frh, tb)) 724 continue; 725 return 1; 726 } 727 return 0; 728 } 729 730 int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh, 731 struct netlink_ext_ack *extack) 732 { 733 struct net *net = sock_net(skb->sk); 734 struct fib_rule_hdr *frh = nlmsg_data(nlh); 735 struct fib_rules_ops *ops = NULL; 736 struct fib_rule *rule = NULL, *r, *last = NULL; 737 struct nlattr *tb[FRA_MAX + 1]; 738 int err = -EINVAL, unresolved = 0; 739 bool user_priority = false; 740 741 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { 742 NL_SET_ERR_MSG(extack, "Invalid msg length"); 743 goto errout; 744 } 745 746 ops = lookup_rules_ops(net, frh->family); 747 if (!ops) { 748 err = -EAFNOSUPPORT; 749 NL_SET_ERR_MSG(extack, "Rule family not supported"); 750 goto errout; 751 } 752 753 err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX, 754 ops->policy, extack); 755 if (err < 0) { 756 NL_SET_ERR_MSG(extack, "Error parsing msg"); 757 goto errout; 758 } 759 760 err = fib_nl2rule(skb, nlh, extack, ops, tb, &rule, &user_priority); 761 if (err) 762 goto errout; 763 764 if ((nlh->nlmsg_flags & NLM_F_EXCL) && 765 rule_exists(ops, frh, tb, rule)) { 766 err = -EEXIST; 767 goto errout_free; 768 } 769 770 err = ops->configure(rule, skb, frh, tb, extack); 771 if (err < 0) 772 goto errout_free; 773 774 err = call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops, 775 extack); 776 if (err < 0) 777 goto errout_free; 778 779 list_for_each_entry(r, &ops->rules_list, list) { 780 if (r->pref == rule->target) { 781 RCU_INIT_POINTER(rule->ctarget, r); 782 break; 783 } 784 } 785 786 if (rcu_dereference_protected(rule->ctarget, 1) == NULL) 787 unresolved = 1; 788 789 list_for_each_entry(r, &ops->rules_list, list) { 790 if (r->pref > rule->pref) 791 break; 792 last = r; 793 } 794 795 if (last) 796 list_add_rcu(&rule->list, &last->list); 797 else 798 list_add_rcu(&rule->list, &ops->rules_list); 799 800 if (ops->unresolved_rules) { 801 /* 802 * There are unresolved goto rules in the list, check if 803 * any of them are pointing to this new rule. 804 */ 805 list_for_each_entry(r, &ops->rules_list, list) { 806 if (r->action == FR_ACT_GOTO && 807 r->target == rule->pref && 808 rtnl_dereference(r->ctarget) == NULL) { 809 rcu_assign_pointer(r->ctarget, rule); 810 if (--ops->unresolved_rules == 0) 811 break; 812 } 813 } 814 } 815 816 if (rule->action == FR_ACT_GOTO) 817 ops->nr_goto_rules++; 818 819 if (unresolved) 820 ops->unresolved_rules++; 821 822 if (rule->tun_id) 823 ip_tunnel_need_metadata(); 824 825 notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid); 826 flush_route_cache(ops); 827 rules_ops_put(ops); 828 return 0; 829 830 errout_free: 831 kfree(rule); 832 errout: 833 rules_ops_put(ops); 834 return err; 835 } 836 EXPORT_SYMBOL_GPL(fib_nl_newrule); 837 838 int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh, 839 struct netlink_ext_ack *extack) 840 { 841 struct net *net = sock_net(skb->sk); 842 struct fib_rule_hdr *frh = nlmsg_data(nlh); 843 struct fib_rules_ops *ops = NULL; 844 struct fib_rule *rule = NULL, *r, *nlrule = NULL; 845 struct nlattr *tb[FRA_MAX+1]; 846 int err = -EINVAL; 847 bool user_priority = false; 848 849 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { 850 NL_SET_ERR_MSG(extack, "Invalid msg length"); 851 goto errout; 852 } 853 854 ops = lookup_rules_ops(net, frh->family); 855 if (ops == NULL) { 856 err = -EAFNOSUPPORT; 857 NL_SET_ERR_MSG(extack, "Rule family not supported"); 858 goto errout; 859 } 860 861 err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX, 862 ops->policy, extack); 863 if (err < 0) { 864 NL_SET_ERR_MSG(extack, "Error parsing msg"); 865 goto errout; 866 } 867 868 err = fib_nl2rule(skb, nlh, extack, ops, tb, &nlrule, &user_priority); 869 if (err) 870 goto errout; 871 872 rule = rule_find(ops, frh, tb, nlrule, user_priority); 873 if (!rule) { 874 err = -ENOENT; 875 goto errout; 876 } 877 878 if (rule->flags & FIB_RULE_PERMANENT) { 879 err = -EPERM; 880 goto errout; 881 } 882 883 if (ops->delete) { 884 err = ops->delete(rule); 885 if (err) 886 goto errout; 887 } 888 889 if (rule->tun_id) 890 ip_tunnel_unneed_metadata(); 891 892 list_del_rcu(&rule->list); 893 894 if (rule->action == FR_ACT_GOTO) { 895 ops->nr_goto_rules--; 896 if (rtnl_dereference(rule->ctarget) == NULL) 897 ops->unresolved_rules--; 898 } 899 900 /* 901 * Check if this rule is a target to any of them. If so, 902 * adjust to the next one with the same preference or 903 * disable them. As this operation is eventually very 904 * expensive, it is only performed if goto rules, except 905 * current if it is goto rule, have actually been added. 906 */ 907 if (ops->nr_goto_rules > 0) { 908 struct fib_rule *n; 909 910 n = list_next_entry(rule, list); 911 if (&n->list == &ops->rules_list || n->pref != rule->pref) 912 n = NULL; 913 list_for_each_entry(r, &ops->rules_list, list) { 914 if (rtnl_dereference(r->ctarget) != rule) 915 continue; 916 rcu_assign_pointer(r->ctarget, n); 917 if (!n) 918 ops->unresolved_rules++; 919 } 920 } 921 922 call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops, 923 NULL); 924 notify_rule_change(RTM_DELRULE, rule, ops, nlh, 925 NETLINK_CB(skb).portid); 926 fib_rule_put(rule); 927 flush_route_cache(ops); 928 rules_ops_put(ops); 929 kfree(nlrule); 930 return 0; 931 932 errout: 933 kfree(nlrule); 934 rules_ops_put(ops); 935 return err; 936 } 937 EXPORT_SYMBOL_GPL(fib_nl_delrule); 938 939 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops, 940 struct fib_rule *rule) 941 { 942 size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr)) 943 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */ 944 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */ 945 + nla_total_size(4) /* FRA_PRIORITY */ 946 + nla_total_size(4) /* FRA_TABLE */ 947 + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */ 948 + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */ 949 + nla_total_size(4) /* FRA_FWMARK */ 950 + nla_total_size(4) /* FRA_FWMASK */ 951 + nla_total_size_64bit(8) /* FRA_TUN_ID */ 952 + nla_total_size(sizeof(struct fib_kuid_range)) 953 + nla_total_size(1) /* FRA_PROTOCOL */ 954 + nla_total_size(1) /* FRA_IP_PROTO */ 955 + nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_SPORT_RANGE */ 956 + nla_total_size(sizeof(struct fib_rule_port_range)); /* FRA_DPORT_RANGE */ 957 958 if (ops->nlmsg_payload) 959 payload += ops->nlmsg_payload(rule); 960 961 return payload; 962 } 963 964 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule, 965 u32 pid, u32 seq, int type, int flags, 966 struct fib_rules_ops *ops) 967 { 968 struct nlmsghdr *nlh; 969 struct fib_rule_hdr *frh; 970 971 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags); 972 if (nlh == NULL) 973 return -EMSGSIZE; 974 975 frh = nlmsg_data(nlh); 976 frh->family = ops->family; 977 frh->table = rule->table; 978 if (nla_put_u32(skb, FRA_TABLE, rule->table)) 979 goto nla_put_failure; 980 if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen)) 981 goto nla_put_failure; 982 frh->res1 = 0; 983 frh->res2 = 0; 984 frh->action = rule->action; 985 frh->flags = rule->flags; 986 987 if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto)) 988 goto nla_put_failure; 989 990 if (rule->action == FR_ACT_GOTO && 991 rcu_access_pointer(rule->ctarget) == NULL) 992 frh->flags |= FIB_RULE_UNRESOLVED; 993 994 if (rule->iifname[0]) { 995 if (nla_put_string(skb, FRA_IIFNAME, rule->iifname)) 996 goto nla_put_failure; 997 if (rule->iifindex == -1) 998 frh->flags |= FIB_RULE_IIF_DETACHED; 999 } 1000 1001 if (rule->oifname[0]) { 1002 if (nla_put_string(skb, FRA_OIFNAME, rule->oifname)) 1003 goto nla_put_failure; 1004 if (rule->oifindex == -1) 1005 frh->flags |= FIB_RULE_OIF_DETACHED; 1006 } 1007 1008 if ((rule->pref && 1009 nla_put_u32(skb, FRA_PRIORITY, rule->pref)) || 1010 (rule->mark && 1011 nla_put_u32(skb, FRA_FWMARK, rule->mark)) || 1012 ((rule->mark_mask || rule->mark) && 1013 nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) || 1014 (rule->target && 1015 nla_put_u32(skb, FRA_GOTO, rule->target)) || 1016 (rule->tun_id && 1017 nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) || 1018 (rule->l3mdev && 1019 nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) || 1020 (uid_range_set(&rule->uid_range) && 1021 nla_put_uid_range(skb, &rule->uid_range)) || 1022 (fib_rule_port_range_set(&rule->sport_range) && 1023 nla_put_port_range(skb, FRA_SPORT_RANGE, &rule->sport_range)) || 1024 (fib_rule_port_range_set(&rule->dport_range) && 1025 nla_put_port_range(skb, FRA_DPORT_RANGE, &rule->dport_range)) || 1026 (rule->ip_proto && nla_put_u8(skb, FRA_IP_PROTO, rule->ip_proto))) 1027 goto nla_put_failure; 1028 1029 if (rule->suppress_ifgroup != -1) { 1030 if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup)) 1031 goto nla_put_failure; 1032 } 1033 1034 if (ops->fill(rule, skb, frh) < 0) 1035 goto nla_put_failure; 1036 1037 nlmsg_end(skb, nlh); 1038 return 0; 1039 1040 nla_put_failure: 1041 nlmsg_cancel(skb, nlh); 1042 return -EMSGSIZE; 1043 } 1044 1045 static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb, 1046 struct fib_rules_ops *ops) 1047 { 1048 int idx = 0; 1049 struct fib_rule *rule; 1050 int err = 0; 1051 1052 rcu_read_lock(); 1053 list_for_each_entry_rcu(rule, &ops->rules_list, list) { 1054 if (idx < cb->args[1]) 1055 goto skip; 1056 1057 err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid, 1058 cb->nlh->nlmsg_seq, RTM_NEWRULE, 1059 NLM_F_MULTI, ops); 1060 if (err) 1061 break; 1062 skip: 1063 idx++; 1064 } 1065 rcu_read_unlock(); 1066 cb->args[1] = idx; 1067 rules_ops_put(ops); 1068 1069 return err; 1070 } 1071 1072 static int fib_valid_dumprule_req(const struct nlmsghdr *nlh, 1073 struct netlink_ext_ack *extack) 1074 { 1075 struct fib_rule_hdr *frh; 1076 1077 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { 1078 NL_SET_ERR_MSG(extack, "Invalid header for fib rule dump request"); 1079 return -EINVAL; 1080 } 1081 1082 frh = nlmsg_data(nlh); 1083 if (frh->dst_len || frh->src_len || frh->tos || frh->table || 1084 frh->res1 || frh->res2 || frh->action || frh->flags) { 1085 NL_SET_ERR_MSG(extack, 1086 "Invalid values in header for fib rule dump request"); 1087 return -EINVAL; 1088 } 1089 1090 if (nlmsg_attrlen(nlh, sizeof(*frh))) { 1091 NL_SET_ERR_MSG(extack, "Invalid data after header in fib rule dump request"); 1092 return -EINVAL; 1093 } 1094 1095 return 0; 1096 } 1097 1098 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb) 1099 { 1100 const struct nlmsghdr *nlh = cb->nlh; 1101 struct net *net = sock_net(skb->sk); 1102 struct fib_rules_ops *ops; 1103 int idx = 0, family; 1104 1105 if (cb->strict_check) { 1106 int err = fib_valid_dumprule_req(nlh, cb->extack); 1107 1108 if (err < 0) 1109 return err; 1110 } 1111 1112 family = rtnl_msg_family(nlh); 1113 if (family != AF_UNSPEC) { 1114 /* Protocol specific dump request */ 1115 ops = lookup_rules_ops(net, family); 1116 if (ops == NULL) 1117 return -EAFNOSUPPORT; 1118 1119 dump_rules(skb, cb, ops); 1120 1121 return skb->len; 1122 } 1123 1124 rcu_read_lock(); 1125 list_for_each_entry_rcu(ops, &net->rules_ops, list) { 1126 if (idx < cb->args[0] || !try_module_get(ops->owner)) 1127 goto skip; 1128 1129 if (dump_rules(skb, cb, ops) < 0) 1130 break; 1131 1132 cb->args[1] = 0; 1133 skip: 1134 idx++; 1135 } 1136 rcu_read_unlock(); 1137 cb->args[0] = idx; 1138 1139 return skb->len; 1140 } 1141 1142 static void notify_rule_change(int event, struct fib_rule *rule, 1143 struct fib_rules_ops *ops, struct nlmsghdr *nlh, 1144 u32 pid) 1145 { 1146 struct net *net; 1147 struct sk_buff *skb; 1148 int err = -ENOBUFS; 1149 1150 net = ops->fro_net; 1151 skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL); 1152 if (skb == NULL) 1153 goto errout; 1154 1155 err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops); 1156 if (err < 0) { 1157 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */ 1158 WARN_ON(err == -EMSGSIZE); 1159 kfree_skb(skb); 1160 goto errout; 1161 } 1162 1163 rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL); 1164 return; 1165 errout: 1166 if (err < 0) 1167 rtnl_set_sk_err(net, ops->nlgroup, err); 1168 } 1169 1170 static void attach_rules(struct list_head *rules, struct net_device *dev) 1171 { 1172 struct fib_rule *rule; 1173 1174 list_for_each_entry(rule, rules, list) { 1175 if (rule->iifindex == -1 && 1176 strcmp(dev->name, rule->iifname) == 0) 1177 rule->iifindex = dev->ifindex; 1178 if (rule->oifindex == -1 && 1179 strcmp(dev->name, rule->oifname) == 0) 1180 rule->oifindex = dev->ifindex; 1181 } 1182 } 1183 1184 static void detach_rules(struct list_head *rules, struct net_device *dev) 1185 { 1186 struct fib_rule *rule; 1187 1188 list_for_each_entry(rule, rules, list) { 1189 if (rule->iifindex == dev->ifindex) 1190 rule->iifindex = -1; 1191 if (rule->oifindex == dev->ifindex) 1192 rule->oifindex = -1; 1193 } 1194 } 1195 1196 1197 static int fib_rules_event(struct notifier_block *this, unsigned long event, 1198 void *ptr) 1199 { 1200 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1201 struct net *net = dev_net(dev); 1202 struct fib_rules_ops *ops; 1203 1204 ASSERT_RTNL(); 1205 1206 switch (event) { 1207 case NETDEV_REGISTER: 1208 list_for_each_entry(ops, &net->rules_ops, list) 1209 attach_rules(&ops->rules_list, dev); 1210 break; 1211 1212 case NETDEV_CHANGENAME: 1213 list_for_each_entry(ops, &net->rules_ops, list) { 1214 detach_rules(&ops->rules_list, dev); 1215 attach_rules(&ops->rules_list, dev); 1216 } 1217 break; 1218 1219 case NETDEV_UNREGISTER: 1220 list_for_each_entry(ops, &net->rules_ops, list) 1221 detach_rules(&ops->rules_list, dev); 1222 break; 1223 } 1224 1225 return NOTIFY_DONE; 1226 } 1227 1228 static struct notifier_block fib_rules_notifier = { 1229 .notifier_call = fib_rules_event, 1230 }; 1231 1232 static int __net_init fib_rules_net_init(struct net *net) 1233 { 1234 INIT_LIST_HEAD(&net->rules_ops); 1235 spin_lock_init(&net->rules_mod_lock); 1236 return 0; 1237 } 1238 1239 static void __net_exit fib_rules_net_exit(struct net *net) 1240 { 1241 WARN_ON_ONCE(!list_empty(&net->rules_ops)); 1242 } 1243 1244 static struct pernet_operations fib_rules_net_ops = { 1245 .init = fib_rules_net_init, 1246 .exit = fib_rules_net_exit, 1247 }; 1248 1249 static int __init fib_rules_init(void) 1250 { 1251 int err; 1252 rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, 0); 1253 rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, 0); 1254 rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, 0); 1255 1256 err = register_pernet_subsys(&fib_rules_net_ops); 1257 if (err < 0) 1258 goto fail; 1259 1260 err = register_netdevice_notifier(&fib_rules_notifier); 1261 if (err < 0) 1262 goto fail_unregister; 1263 1264 return 0; 1265 1266 fail_unregister: 1267 unregister_pernet_subsys(&fib_rules_net_ops); 1268 fail: 1269 rtnl_unregister(PF_UNSPEC, RTM_NEWRULE); 1270 rtnl_unregister(PF_UNSPEC, RTM_DELRULE); 1271 rtnl_unregister(PF_UNSPEC, RTM_GETRULE); 1272 return err; 1273 } 1274 1275 subsys_initcall(fib_rules_init); 1276