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/inet_dscp.h> 15 #include <net/sock.h> 16 #include <net/fib_rules.h> 17 #include <net/ip_tunnels.h> 18 #include <linux/indirect_call_wrapper.h> 19 20 #if defined(CONFIG_IPV6) && defined(CONFIG_IPV6_MULTIPLE_TABLES) 21 #ifdef CONFIG_IP_MULTIPLE_TABLES 22 #define INDIRECT_CALL_MT(f, f2, f1, ...) \ 23 INDIRECT_CALL_INET(f, f2, f1, __VA_ARGS__) 24 #else 25 #define INDIRECT_CALL_MT(f, f2, f1, ...) INDIRECT_CALL_1(f, f2, __VA_ARGS__) 26 #endif 27 #elif defined(CONFIG_IP_MULTIPLE_TABLES) 28 #define INDIRECT_CALL_MT(f, f2, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__) 29 #else 30 #define INDIRECT_CALL_MT(f, f2, f1, ...) f(__VA_ARGS__) 31 #endif 32 33 static const struct fib_kuid_range fib_kuid_range_unset = { 34 KUIDT_INIT(0), 35 KUIDT_INIT(~0), 36 }; 37 38 bool fib_rule_matchall(const struct fib_rule *rule) 39 { 40 if (rule->iifindex || rule->oifindex || rule->mark || rule->tun_id || 41 rule->flags) 42 return false; 43 if (rule->suppress_ifgroup != -1 || rule->suppress_prefixlen != -1) 44 return false; 45 if (!uid_eq(rule->uid_range.start, fib_kuid_range_unset.start) || 46 !uid_eq(rule->uid_range.end, fib_kuid_range_unset.end)) 47 return false; 48 if (fib_rule_port_range_set(&rule->sport_range)) 49 return false; 50 if (fib_rule_port_range_set(&rule->dport_range)) 51 return false; 52 return true; 53 } 54 EXPORT_SYMBOL_GPL(fib_rule_matchall); 55 56 int fib_default_rule_add(struct fib_rules_ops *ops, 57 u32 pref, u32 table) 58 { 59 struct fib_rule *r; 60 61 r = kzalloc(ops->rule_size, GFP_KERNEL_ACCOUNT); 62 if (r == NULL) 63 return -ENOMEM; 64 65 refcount_set(&r->refcnt, 1); 66 r->action = FR_ACT_TO_TBL; 67 r->pref = pref; 68 r->table = table; 69 r->proto = RTPROT_KERNEL; 70 r->fr_net = ops->fro_net; 71 r->uid_range = fib_kuid_range_unset; 72 73 r->suppress_prefixlen = -1; 74 r->suppress_ifgroup = -1; 75 76 /* The lock is not required here, the list in unreachable 77 * at the moment this function is called */ 78 list_add_tail(&r->list, &ops->rules_list); 79 return 0; 80 } 81 EXPORT_SYMBOL(fib_default_rule_add); 82 83 static u32 fib_default_rule_pref(struct fib_rules_ops *ops) 84 { 85 struct list_head *pos; 86 struct fib_rule *rule; 87 88 if (!list_empty(&ops->rules_list)) { 89 pos = ops->rules_list.next; 90 if (pos->next != &ops->rules_list) { 91 rule = list_entry(pos->next, struct fib_rule, list); 92 if (rule->pref) 93 return rule->pref - 1; 94 } 95 } 96 97 return 0; 98 } 99 100 static void notify_rule_change(int event, struct fib_rule *rule, 101 struct fib_rules_ops *ops, struct nlmsghdr *nlh, 102 u32 pid); 103 104 static struct fib_rules_ops *lookup_rules_ops(const struct net *net, 105 int family) 106 { 107 struct fib_rules_ops *ops; 108 109 rcu_read_lock(); 110 list_for_each_entry_rcu(ops, &net->rules_ops, list) { 111 if (ops->family == family) { 112 if (!try_module_get(ops->owner)) 113 ops = NULL; 114 rcu_read_unlock(); 115 return ops; 116 } 117 } 118 rcu_read_unlock(); 119 120 return NULL; 121 } 122 123 static void rules_ops_put(struct fib_rules_ops *ops) 124 { 125 if (ops) 126 module_put(ops->owner); 127 } 128 129 static void flush_route_cache(struct fib_rules_ops *ops) 130 { 131 if (ops->flush_cache) 132 ops->flush_cache(ops); 133 } 134 135 static int __fib_rules_register(struct fib_rules_ops *ops) 136 { 137 int err = -EEXIST; 138 struct fib_rules_ops *o; 139 struct net *net; 140 141 net = ops->fro_net; 142 143 if (ops->rule_size < sizeof(struct fib_rule)) 144 return -EINVAL; 145 146 if (ops->match == NULL || ops->configure == NULL || 147 ops->compare == NULL || ops->fill == NULL || 148 ops->action == NULL) 149 return -EINVAL; 150 151 spin_lock(&net->rules_mod_lock); 152 list_for_each_entry(o, &net->rules_ops, list) 153 if (ops->family == o->family) 154 goto errout; 155 156 list_add_tail_rcu(&ops->list, &net->rules_ops); 157 err = 0; 158 errout: 159 spin_unlock(&net->rules_mod_lock); 160 161 return err; 162 } 163 164 struct fib_rules_ops * 165 fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net) 166 { 167 struct fib_rules_ops *ops; 168 int err; 169 170 ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL); 171 if (ops == NULL) 172 return ERR_PTR(-ENOMEM); 173 174 INIT_LIST_HEAD(&ops->rules_list); 175 ops->fro_net = net; 176 177 err = __fib_rules_register(ops); 178 if (err) { 179 kfree(ops); 180 ops = ERR_PTR(err); 181 } 182 183 return ops; 184 } 185 EXPORT_SYMBOL_GPL(fib_rules_register); 186 187 static void fib_rules_cleanup_ops(struct fib_rules_ops *ops) 188 { 189 struct fib_rule *rule, *tmp; 190 191 list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) { 192 list_del_rcu(&rule->list); 193 if (ops->delete) 194 ops->delete(rule); 195 fib_rule_put(rule); 196 } 197 } 198 199 void fib_rules_unregister(struct fib_rules_ops *ops) 200 { 201 struct net *net = ops->fro_net; 202 203 spin_lock(&net->rules_mod_lock); 204 list_del_rcu(&ops->list); 205 spin_unlock(&net->rules_mod_lock); 206 207 fib_rules_cleanup_ops(ops); 208 kfree_rcu(ops, rcu); 209 } 210 EXPORT_SYMBOL_GPL(fib_rules_unregister); 211 212 static int uid_range_set(struct fib_kuid_range *range) 213 { 214 return uid_valid(range->start) && uid_valid(range->end); 215 } 216 217 static struct fib_kuid_range nla_get_kuid_range(struct nlattr **tb) 218 { 219 struct fib_rule_uid_range *in; 220 struct fib_kuid_range out; 221 222 in = (struct fib_rule_uid_range *)nla_data(tb[FRA_UID_RANGE]); 223 224 out.start = make_kuid(current_user_ns(), in->start); 225 out.end = make_kuid(current_user_ns(), in->end); 226 227 return out; 228 } 229 230 static int nla_put_uid_range(struct sk_buff *skb, struct fib_kuid_range *range) 231 { 232 struct fib_rule_uid_range out = { 233 from_kuid_munged(current_user_ns(), range->start), 234 from_kuid_munged(current_user_ns(), range->end) 235 }; 236 237 return nla_put(skb, FRA_UID_RANGE, sizeof(out), &out); 238 } 239 240 static int nla_get_port_range(struct nlattr *pattr, 241 struct fib_rule_port_range *port_range) 242 { 243 const struct fib_rule_port_range *pr = nla_data(pattr); 244 245 if (!fib_rule_port_range_valid(pr)) 246 return -EINVAL; 247 248 port_range->start = pr->start; 249 port_range->end = pr->end; 250 251 return 0; 252 } 253 254 static int nla_put_port_range(struct sk_buff *skb, int attrtype, 255 struct fib_rule_port_range *range) 256 { 257 return nla_put(skb, attrtype, sizeof(*range), range); 258 } 259 260 static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops, 261 struct flowi *fl, int flags, 262 struct fib_lookup_arg *arg) 263 { 264 int ret = 0; 265 266 if (rule->iifindex && (rule->iifindex != fl->flowi_iif)) 267 goto out; 268 269 if (rule->oifindex && (rule->oifindex != fl->flowi_oif)) 270 goto out; 271 272 if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask) 273 goto out; 274 275 if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id)) 276 goto out; 277 278 if (rule->l3mdev && !l3mdev_fib_rule_match(rule->fr_net, fl, arg)) 279 goto out; 280 281 if (uid_lt(fl->flowi_uid, rule->uid_range.start) || 282 uid_gt(fl->flowi_uid, rule->uid_range.end)) 283 goto out; 284 285 ret = INDIRECT_CALL_MT(ops->match, 286 fib6_rule_match, 287 fib4_rule_match, 288 rule, fl, flags); 289 out: 290 return (rule->flags & FIB_RULE_INVERT) ? !ret : ret; 291 } 292 293 int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl, 294 int flags, struct fib_lookup_arg *arg) 295 { 296 struct fib_rule *rule; 297 int err; 298 299 rcu_read_lock(); 300 301 list_for_each_entry_rcu(rule, &ops->rules_list, list) { 302 jumped: 303 if (!fib_rule_match(rule, ops, fl, flags, arg)) 304 continue; 305 306 if (rule->action == FR_ACT_GOTO) { 307 struct fib_rule *target; 308 309 target = rcu_dereference(rule->ctarget); 310 if (target == NULL) { 311 continue; 312 } else { 313 rule = target; 314 goto jumped; 315 } 316 } else if (rule->action == FR_ACT_NOP) 317 continue; 318 else 319 err = INDIRECT_CALL_MT(ops->action, 320 fib6_rule_action, 321 fib4_rule_action, 322 rule, fl, flags, arg); 323 324 if (!err && ops->suppress && INDIRECT_CALL_MT(ops->suppress, 325 fib6_rule_suppress, 326 fib4_rule_suppress, 327 rule, flags, arg)) 328 continue; 329 330 if (err != -EAGAIN) { 331 if ((arg->flags & FIB_LOOKUP_NOREF) || 332 likely(refcount_inc_not_zero(&rule->refcnt))) { 333 arg->rule = rule; 334 goto out; 335 } 336 break; 337 } 338 } 339 340 err = -ESRCH; 341 out: 342 rcu_read_unlock(); 343 344 return err; 345 } 346 EXPORT_SYMBOL_GPL(fib_rules_lookup); 347 348 static int call_fib_rule_notifier(struct notifier_block *nb, 349 enum fib_event_type event_type, 350 struct fib_rule *rule, int family, 351 struct netlink_ext_ack *extack) 352 { 353 struct fib_rule_notifier_info info = { 354 .info.family = family, 355 .info.extack = extack, 356 .rule = rule, 357 }; 358 359 return call_fib_notifier(nb, event_type, &info.info); 360 } 361 362 static int call_fib_rule_notifiers(struct net *net, 363 enum fib_event_type event_type, 364 struct fib_rule *rule, 365 struct fib_rules_ops *ops, 366 struct netlink_ext_ack *extack) 367 { 368 struct fib_rule_notifier_info info = { 369 .info.family = ops->family, 370 .info.extack = extack, 371 .rule = rule, 372 }; 373 374 ASSERT_RTNL(); 375 /* Paired with READ_ONCE() in fib_rules_seq() */ 376 WRITE_ONCE(ops->fib_rules_seq, ops->fib_rules_seq + 1); 377 return call_fib_notifiers(net, event_type, &info.info); 378 } 379 380 /* Called with rcu_read_lock() */ 381 int fib_rules_dump(struct net *net, struct notifier_block *nb, int family, 382 struct netlink_ext_ack *extack) 383 { 384 struct fib_rules_ops *ops; 385 struct fib_rule *rule; 386 int err = 0; 387 388 ops = lookup_rules_ops(net, family); 389 if (!ops) 390 return -EAFNOSUPPORT; 391 list_for_each_entry_rcu(rule, &ops->rules_list, list) { 392 err = call_fib_rule_notifier(nb, FIB_EVENT_RULE_ADD, 393 rule, family, extack); 394 if (err) 395 break; 396 } 397 rules_ops_put(ops); 398 399 return err; 400 } 401 EXPORT_SYMBOL_GPL(fib_rules_dump); 402 403 unsigned int fib_rules_seq_read(const struct net *net, int family) 404 { 405 unsigned int fib_rules_seq; 406 struct fib_rules_ops *ops; 407 408 ops = lookup_rules_ops(net, family); 409 if (!ops) 410 return 0; 411 /* Paired with WRITE_ONCE() in call_fib_rule_notifiers() */ 412 fib_rules_seq = READ_ONCE(ops->fib_rules_seq); 413 rules_ops_put(ops); 414 415 return fib_rules_seq; 416 } 417 EXPORT_SYMBOL_GPL(fib_rules_seq_read); 418 419 static struct fib_rule *rule_find(struct fib_rules_ops *ops, 420 struct fib_rule_hdr *frh, 421 struct nlattr **tb, 422 struct fib_rule *rule, 423 bool user_priority) 424 { 425 struct fib_rule *r; 426 427 list_for_each_entry(r, &ops->rules_list, list) { 428 if (rule->action && r->action != rule->action) 429 continue; 430 431 if (rule->table && r->table != rule->table) 432 continue; 433 434 if (user_priority && r->pref != rule->pref) 435 continue; 436 437 if (rule->iifname[0] && 438 memcmp(r->iifname, rule->iifname, IFNAMSIZ)) 439 continue; 440 441 if (rule->oifname[0] && 442 memcmp(r->oifname, rule->oifname, IFNAMSIZ)) 443 continue; 444 445 if (rule->mark && r->mark != rule->mark) 446 continue; 447 448 if (rule->suppress_ifgroup != -1 && 449 r->suppress_ifgroup != rule->suppress_ifgroup) 450 continue; 451 452 if (rule->suppress_prefixlen != -1 && 453 r->suppress_prefixlen != rule->suppress_prefixlen) 454 continue; 455 456 if (rule->mark_mask && r->mark_mask != rule->mark_mask) 457 continue; 458 459 if (rule->tun_id && r->tun_id != rule->tun_id) 460 continue; 461 462 if (r->fr_net != rule->fr_net) 463 continue; 464 465 if (rule->l3mdev && r->l3mdev != rule->l3mdev) 466 continue; 467 468 if (uid_range_set(&rule->uid_range) && 469 (!uid_eq(r->uid_range.start, rule->uid_range.start) || 470 !uid_eq(r->uid_range.end, rule->uid_range.end))) 471 continue; 472 473 if (rule->ip_proto && r->ip_proto != rule->ip_proto) 474 continue; 475 476 if (rule->proto && r->proto != rule->proto) 477 continue; 478 479 if (fib_rule_port_range_set(&rule->sport_range) && 480 !fib_rule_port_range_compare(&r->sport_range, 481 &rule->sport_range)) 482 continue; 483 484 if (fib_rule_port_range_set(&rule->dport_range) && 485 !fib_rule_port_range_compare(&r->dport_range, 486 &rule->dport_range)) 487 continue; 488 489 if (!ops->compare(r, frh, tb)) 490 continue; 491 return r; 492 } 493 494 return NULL; 495 } 496 497 #ifdef CONFIG_NET_L3_MASTER_DEV 498 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule, 499 struct netlink_ext_ack *extack) 500 { 501 nlrule->l3mdev = nla_get_u8(nla); 502 if (nlrule->l3mdev != 1) { 503 NL_SET_ERR_MSG(extack, "Invalid l3mdev attribute"); 504 return -1; 505 } 506 507 return 0; 508 } 509 #else 510 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule, 511 struct netlink_ext_ack *extack) 512 { 513 NL_SET_ERR_MSG(extack, "l3mdev support is not enabled in kernel"); 514 return -1; 515 } 516 #endif 517 518 static int fib_nl2rule(struct sk_buff *skb, struct nlmsghdr *nlh, 519 struct netlink_ext_ack *extack, 520 struct fib_rules_ops *ops, 521 struct nlattr *tb[], 522 struct fib_rule **rule, 523 bool *user_priority) 524 { 525 struct net *net = sock_net(skb->sk); 526 struct fib_rule_hdr *frh = nlmsg_data(nlh); 527 struct fib_rule *nlrule = NULL; 528 int err = -EINVAL; 529 530 if (frh->src_len) 531 if (!tb[FRA_SRC] || 532 frh->src_len > (ops->addr_size * 8) || 533 nla_len(tb[FRA_SRC]) != ops->addr_size) { 534 NL_SET_ERR_MSG(extack, "Invalid source address"); 535 goto errout; 536 } 537 538 if (frh->dst_len) 539 if (!tb[FRA_DST] || 540 frh->dst_len > (ops->addr_size * 8) || 541 nla_len(tb[FRA_DST]) != ops->addr_size) { 542 NL_SET_ERR_MSG(extack, "Invalid dst address"); 543 goto errout; 544 } 545 546 nlrule = kzalloc(ops->rule_size, GFP_KERNEL_ACCOUNT); 547 if (!nlrule) { 548 err = -ENOMEM; 549 goto errout; 550 } 551 refcount_set(&nlrule->refcnt, 1); 552 nlrule->fr_net = net; 553 554 if (tb[FRA_PRIORITY]) { 555 nlrule->pref = nla_get_u32(tb[FRA_PRIORITY]); 556 *user_priority = true; 557 } else { 558 nlrule->pref = fib_default_rule_pref(ops); 559 } 560 561 nlrule->proto = tb[FRA_PROTOCOL] ? 562 nla_get_u8(tb[FRA_PROTOCOL]) : RTPROT_UNSPEC; 563 564 if (tb[FRA_IIFNAME]) { 565 struct net_device *dev; 566 567 nlrule->iifindex = -1; 568 nla_strscpy(nlrule->iifname, tb[FRA_IIFNAME], IFNAMSIZ); 569 dev = __dev_get_by_name(net, nlrule->iifname); 570 if (dev) 571 nlrule->iifindex = dev->ifindex; 572 } 573 574 if (tb[FRA_OIFNAME]) { 575 struct net_device *dev; 576 577 nlrule->oifindex = -1; 578 nla_strscpy(nlrule->oifname, tb[FRA_OIFNAME], IFNAMSIZ); 579 dev = __dev_get_by_name(net, nlrule->oifname); 580 if (dev) 581 nlrule->oifindex = dev->ifindex; 582 } 583 584 if (tb[FRA_FWMARK]) { 585 nlrule->mark = nla_get_u32(tb[FRA_FWMARK]); 586 if (nlrule->mark) 587 /* compatibility: if the mark value is non-zero all bits 588 * are compared unless a mask is explicitly specified. 589 */ 590 nlrule->mark_mask = 0xFFFFFFFF; 591 } 592 593 if (tb[FRA_FWMASK]) 594 nlrule->mark_mask = nla_get_u32(tb[FRA_FWMASK]); 595 596 if (tb[FRA_TUN_ID]) 597 nlrule->tun_id = nla_get_be64(tb[FRA_TUN_ID]); 598 599 if (tb[FRA_L3MDEV] && 600 fib_nl2rule_l3mdev(tb[FRA_L3MDEV], nlrule, extack) < 0) 601 goto errout_free; 602 603 nlrule->action = frh->action; 604 nlrule->flags = frh->flags; 605 nlrule->table = frh_get_table(frh, tb); 606 if (tb[FRA_SUPPRESS_PREFIXLEN]) 607 nlrule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]); 608 else 609 nlrule->suppress_prefixlen = -1; 610 611 if (tb[FRA_SUPPRESS_IFGROUP]) 612 nlrule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]); 613 else 614 nlrule->suppress_ifgroup = -1; 615 616 if (tb[FRA_GOTO]) { 617 if (nlrule->action != FR_ACT_GOTO) { 618 NL_SET_ERR_MSG(extack, "Unexpected goto"); 619 goto errout_free; 620 } 621 622 nlrule->target = nla_get_u32(tb[FRA_GOTO]); 623 /* Backward jumps are prohibited to avoid endless loops */ 624 if (nlrule->target <= nlrule->pref) { 625 NL_SET_ERR_MSG(extack, "Backward goto not supported"); 626 goto errout_free; 627 } 628 } else if (nlrule->action == FR_ACT_GOTO) { 629 NL_SET_ERR_MSG(extack, "Missing goto target for action goto"); 630 goto errout_free; 631 } 632 633 if (nlrule->l3mdev && nlrule->table) { 634 NL_SET_ERR_MSG(extack, "l3mdev and table are mutually exclusive"); 635 goto errout_free; 636 } 637 638 if (tb[FRA_UID_RANGE]) { 639 if (current_user_ns() != net->user_ns) { 640 err = -EPERM; 641 NL_SET_ERR_MSG(extack, "No permission to set uid"); 642 goto errout_free; 643 } 644 645 nlrule->uid_range = nla_get_kuid_range(tb); 646 647 if (!uid_range_set(&nlrule->uid_range) || 648 !uid_lte(nlrule->uid_range.start, nlrule->uid_range.end)) { 649 NL_SET_ERR_MSG(extack, "Invalid uid range"); 650 goto errout_free; 651 } 652 } else { 653 nlrule->uid_range = fib_kuid_range_unset; 654 } 655 656 if (tb[FRA_IP_PROTO]) 657 nlrule->ip_proto = nla_get_u8(tb[FRA_IP_PROTO]); 658 659 if (tb[FRA_SPORT_RANGE]) { 660 err = nla_get_port_range(tb[FRA_SPORT_RANGE], 661 &nlrule->sport_range); 662 if (err) { 663 NL_SET_ERR_MSG(extack, "Invalid sport range"); 664 goto errout_free; 665 } 666 } 667 668 if (tb[FRA_DPORT_RANGE]) { 669 err = nla_get_port_range(tb[FRA_DPORT_RANGE], 670 &nlrule->dport_range); 671 if (err) { 672 NL_SET_ERR_MSG(extack, "Invalid dport range"); 673 goto errout_free; 674 } 675 } 676 677 *rule = nlrule; 678 679 return 0; 680 681 errout_free: 682 kfree(nlrule); 683 errout: 684 return err; 685 } 686 687 static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh, 688 struct nlattr **tb, struct fib_rule *rule) 689 { 690 struct fib_rule *r; 691 692 list_for_each_entry(r, &ops->rules_list, list) { 693 if (r->action != rule->action) 694 continue; 695 696 if (r->table != rule->table) 697 continue; 698 699 if (r->pref != rule->pref) 700 continue; 701 702 if (memcmp(r->iifname, rule->iifname, IFNAMSIZ)) 703 continue; 704 705 if (memcmp(r->oifname, rule->oifname, IFNAMSIZ)) 706 continue; 707 708 if (r->mark != rule->mark) 709 continue; 710 711 if (r->suppress_ifgroup != rule->suppress_ifgroup) 712 continue; 713 714 if (r->suppress_prefixlen != rule->suppress_prefixlen) 715 continue; 716 717 if (r->mark_mask != rule->mark_mask) 718 continue; 719 720 if (r->tun_id != rule->tun_id) 721 continue; 722 723 if (r->fr_net != rule->fr_net) 724 continue; 725 726 if (r->l3mdev != rule->l3mdev) 727 continue; 728 729 if (!uid_eq(r->uid_range.start, rule->uid_range.start) || 730 !uid_eq(r->uid_range.end, rule->uid_range.end)) 731 continue; 732 733 if (r->ip_proto != rule->ip_proto) 734 continue; 735 736 if (r->proto != rule->proto) 737 continue; 738 739 if (!fib_rule_port_range_compare(&r->sport_range, 740 &rule->sport_range)) 741 continue; 742 743 if (!fib_rule_port_range_compare(&r->dport_range, 744 &rule->dport_range)) 745 continue; 746 747 if (!ops->compare(r, frh, tb)) 748 continue; 749 return 1; 750 } 751 return 0; 752 } 753 754 static const struct nla_policy fib_rule_policy[FRA_MAX + 1] = { 755 [FRA_UNSPEC] = { .strict_start_type = FRA_DPORT_RANGE + 1 }, 756 [FRA_IIFNAME] = { .type = NLA_STRING, .len = IFNAMSIZ - 1 }, 757 [FRA_OIFNAME] = { .type = NLA_STRING, .len = IFNAMSIZ - 1 }, 758 [FRA_PRIORITY] = { .type = NLA_U32 }, 759 [FRA_FWMARK] = { .type = NLA_U32 }, 760 [FRA_FLOW] = { .type = NLA_U32 }, 761 [FRA_TUN_ID] = { .type = NLA_U64 }, 762 [FRA_FWMASK] = { .type = NLA_U32 }, 763 [FRA_TABLE] = { .type = NLA_U32 }, 764 [FRA_SUPPRESS_PREFIXLEN] = { .type = NLA_U32 }, 765 [FRA_SUPPRESS_IFGROUP] = { .type = NLA_U32 }, 766 [FRA_GOTO] = { .type = NLA_U32 }, 767 [FRA_L3MDEV] = { .type = NLA_U8 }, 768 [FRA_UID_RANGE] = { .len = sizeof(struct fib_rule_uid_range) }, 769 [FRA_PROTOCOL] = { .type = NLA_U8 }, 770 [FRA_IP_PROTO] = { .type = NLA_U8 }, 771 [FRA_SPORT_RANGE] = { .len = sizeof(struct fib_rule_port_range) }, 772 [FRA_DPORT_RANGE] = { .len = sizeof(struct fib_rule_port_range) }, 773 [FRA_DSCP] = NLA_POLICY_MAX(NLA_U8, INET_DSCP_MASK >> 2), 774 }; 775 776 int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh, 777 struct netlink_ext_ack *extack) 778 { 779 struct net *net = sock_net(skb->sk); 780 struct fib_rule_hdr *frh = nlmsg_data(nlh); 781 struct fib_rules_ops *ops = NULL; 782 struct fib_rule *rule = NULL, *r, *last = NULL; 783 struct nlattr *tb[FRA_MAX + 1]; 784 int err = -EINVAL, unresolved = 0; 785 bool user_priority = false; 786 787 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { 788 NL_SET_ERR_MSG(extack, "Invalid msg length"); 789 goto errout; 790 } 791 792 ops = lookup_rules_ops(net, frh->family); 793 if (!ops) { 794 err = -EAFNOSUPPORT; 795 NL_SET_ERR_MSG(extack, "Rule family not supported"); 796 goto errout; 797 } 798 799 err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX, 800 fib_rule_policy, extack); 801 if (err < 0) { 802 NL_SET_ERR_MSG(extack, "Error parsing msg"); 803 goto errout; 804 } 805 806 err = fib_nl2rule(skb, nlh, extack, ops, tb, &rule, &user_priority); 807 if (err) 808 goto errout; 809 810 if ((nlh->nlmsg_flags & NLM_F_EXCL) && 811 rule_exists(ops, frh, tb, rule)) { 812 err = -EEXIST; 813 goto errout_free; 814 } 815 816 err = ops->configure(rule, skb, frh, tb, extack); 817 if (err < 0) 818 goto errout_free; 819 820 err = call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops, 821 extack); 822 if (err < 0) 823 goto errout_free; 824 825 list_for_each_entry(r, &ops->rules_list, list) { 826 if (r->pref == rule->target) { 827 RCU_INIT_POINTER(rule->ctarget, r); 828 break; 829 } 830 } 831 832 if (rcu_dereference_protected(rule->ctarget, 1) == NULL) 833 unresolved = 1; 834 835 list_for_each_entry(r, &ops->rules_list, list) { 836 if (r->pref > rule->pref) 837 break; 838 last = r; 839 } 840 841 if (last) 842 list_add_rcu(&rule->list, &last->list); 843 else 844 list_add_rcu(&rule->list, &ops->rules_list); 845 846 if (ops->unresolved_rules) { 847 /* 848 * There are unresolved goto rules in the list, check if 849 * any of them are pointing to this new rule. 850 */ 851 list_for_each_entry(r, &ops->rules_list, list) { 852 if (r->action == FR_ACT_GOTO && 853 r->target == rule->pref && 854 rtnl_dereference(r->ctarget) == NULL) { 855 rcu_assign_pointer(r->ctarget, rule); 856 if (--ops->unresolved_rules == 0) 857 break; 858 } 859 } 860 } 861 862 if (rule->action == FR_ACT_GOTO) 863 ops->nr_goto_rules++; 864 865 if (unresolved) 866 ops->unresolved_rules++; 867 868 if (rule->tun_id) 869 ip_tunnel_need_metadata(); 870 871 notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid); 872 flush_route_cache(ops); 873 rules_ops_put(ops); 874 return 0; 875 876 errout_free: 877 kfree(rule); 878 errout: 879 rules_ops_put(ops); 880 return err; 881 } 882 EXPORT_SYMBOL_GPL(fib_nl_newrule); 883 884 int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh, 885 struct netlink_ext_ack *extack) 886 { 887 struct net *net = sock_net(skb->sk); 888 struct fib_rule_hdr *frh = nlmsg_data(nlh); 889 struct fib_rules_ops *ops = NULL; 890 struct fib_rule *rule = NULL, *r, *nlrule = NULL; 891 struct nlattr *tb[FRA_MAX+1]; 892 int err = -EINVAL; 893 bool user_priority = false; 894 895 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { 896 NL_SET_ERR_MSG(extack, "Invalid msg length"); 897 goto errout; 898 } 899 900 ops = lookup_rules_ops(net, frh->family); 901 if (ops == NULL) { 902 err = -EAFNOSUPPORT; 903 NL_SET_ERR_MSG(extack, "Rule family not supported"); 904 goto errout; 905 } 906 907 err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX, 908 fib_rule_policy, extack); 909 if (err < 0) { 910 NL_SET_ERR_MSG(extack, "Error parsing msg"); 911 goto errout; 912 } 913 914 err = fib_nl2rule(skb, nlh, extack, ops, tb, &nlrule, &user_priority); 915 if (err) 916 goto errout; 917 918 rule = rule_find(ops, frh, tb, nlrule, user_priority); 919 if (!rule) { 920 err = -ENOENT; 921 goto errout; 922 } 923 924 if (rule->flags & FIB_RULE_PERMANENT) { 925 err = -EPERM; 926 goto errout; 927 } 928 929 if (ops->delete) { 930 err = ops->delete(rule); 931 if (err) 932 goto errout; 933 } 934 935 if (rule->tun_id) 936 ip_tunnel_unneed_metadata(); 937 938 list_del_rcu(&rule->list); 939 940 if (rule->action == FR_ACT_GOTO) { 941 ops->nr_goto_rules--; 942 if (rtnl_dereference(rule->ctarget) == NULL) 943 ops->unresolved_rules--; 944 } 945 946 /* 947 * Check if this rule is a target to any of them. If so, 948 * adjust to the next one with the same preference or 949 * disable them. As this operation is eventually very 950 * expensive, it is only performed if goto rules, except 951 * current if it is goto rule, have actually been added. 952 */ 953 if (ops->nr_goto_rules > 0) { 954 struct fib_rule *n; 955 956 n = list_next_entry(rule, list); 957 if (&n->list == &ops->rules_list || n->pref != rule->pref) 958 n = NULL; 959 list_for_each_entry(r, &ops->rules_list, list) { 960 if (rtnl_dereference(r->ctarget) != rule) 961 continue; 962 rcu_assign_pointer(r->ctarget, n); 963 if (!n) 964 ops->unresolved_rules++; 965 } 966 } 967 968 call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops, 969 NULL); 970 notify_rule_change(RTM_DELRULE, rule, ops, nlh, 971 NETLINK_CB(skb).portid); 972 fib_rule_put(rule); 973 flush_route_cache(ops); 974 rules_ops_put(ops); 975 kfree(nlrule); 976 return 0; 977 978 errout: 979 kfree(nlrule); 980 rules_ops_put(ops); 981 return err; 982 } 983 EXPORT_SYMBOL_GPL(fib_nl_delrule); 984 985 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops, 986 struct fib_rule *rule) 987 { 988 size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr)) 989 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */ 990 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */ 991 + nla_total_size(4) /* FRA_PRIORITY */ 992 + nla_total_size(4) /* FRA_TABLE */ 993 + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */ 994 + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */ 995 + nla_total_size(4) /* FRA_FWMARK */ 996 + nla_total_size(4) /* FRA_FWMASK */ 997 + nla_total_size_64bit(8) /* FRA_TUN_ID */ 998 + nla_total_size(sizeof(struct fib_kuid_range)) 999 + nla_total_size(1) /* FRA_PROTOCOL */ 1000 + nla_total_size(1) /* FRA_IP_PROTO */ 1001 + nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_SPORT_RANGE */ 1002 + nla_total_size(sizeof(struct fib_rule_port_range)); /* FRA_DPORT_RANGE */ 1003 1004 if (ops->nlmsg_payload) 1005 payload += ops->nlmsg_payload(rule); 1006 1007 return payload; 1008 } 1009 1010 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule, 1011 u32 pid, u32 seq, int type, int flags, 1012 struct fib_rules_ops *ops) 1013 { 1014 struct nlmsghdr *nlh; 1015 struct fib_rule_hdr *frh; 1016 1017 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags); 1018 if (nlh == NULL) 1019 return -EMSGSIZE; 1020 1021 frh = nlmsg_data(nlh); 1022 frh->family = ops->family; 1023 frh->table = rule->table < 256 ? rule->table : RT_TABLE_COMPAT; 1024 if (nla_put_u32(skb, FRA_TABLE, rule->table)) 1025 goto nla_put_failure; 1026 if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen)) 1027 goto nla_put_failure; 1028 frh->res1 = 0; 1029 frh->res2 = 0; 1030 frh->action = rule->action; 1031 frh->flags = rule->flags; 1032 1033 if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto)) 1034 goto nla_put_failure; 1035 1036 if (rule->action == FR_ACT_GOTO && 1037 rcu_access_pointer(rule->ctarget) == NULL) 1038 frh->flags |= FIB_RULE_UNRESOLVED; 1039 1040 if (rule->iifname[0]) { 1041 if (nla_put_string(skb, FRA_IIFNAME, rule->iifname)) 1042 goto nla_put_failure; 1043 if (rule->iifindex == -1) 1044 frh->flags |= FIB_RULE_IIF_DETACHED; 1045 } 1046 1047 if (rule->oifname[0]) { 1048 if (nla_put_string(skb, FRA_OIFNAME, rule->oifname)) 1049 goto nla_put_failure; 1050 if (rule->oifindex == -1) 1051 frh->flags |= FIB_RULE_OIF_DETACHED; 1052 } 1053 1054 if ((rule->pref && 1055 nla_put_u32(skb, FRA_PRIORITY, rule->pref)) || 1056 (rule->mark && 1057 nla_put_u32(skb, FRA_FWMARK, rule->mark)) || 1058 ((rule->mark_mask || rule->mark) && 1059 nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) || 1060 (rule->target && 1061 nla_put_u32(skb, FRA_GOTO, rule->target)) || 1062 (rule->tun_id && 1063 nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) || 1064 (rule->l3mdev && 1065 nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) || 1066 (uid_range_set(&rule->uid_range) && 1067 nla_put_uid_range(skb, &rule->uid_range)) || 1068 (fib_rule_port_range_set(&rule->sport_range) && 1069 nla_put_port_range(skb, FRA_SPORT_RANGE, &rule->sport_range)) || 1070 (fib_rule_port_range_set(&rule->dport_range) && 1071 nla_put_port_range(skb, FRA_DPORT_RANGE, &rule->dport_range)) || 1072 (rule->ip_proto && nla_put_u8(skb, FRA_IP_PROTO, rule->ip_proto))) 1073 goto nla_put_failure; 1074 1075 if (rule->suppress_ifgroup != -1) { 1076 if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup)) 1077 goto nla_put_failure; 1078 } 1079 1080 if (ops->fill(rule, skb, frh) < 0) 1081 goto nla_put_failure; 1082 1083 nlmsg_end(skb, nlh); 1084 return 0; 1085 1086 nla_put_failure: 1087 nlmsg_cancel(skb, nlh); 1088 return -EMSGSIZE; 1089 } 1090 1091 static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb, 1092 struct fib_rules_ops *ops) 1093 { 1094 int idx = 0; 1095 struct fib_rule *rule; 1096 int err = 0; 1097 1098 rcu_read_lock(); 1099 list_for_each_entry_rcu(rule, &ops->rules_list, list) { 1100 if (idx < cb->args[1]) 1101 goto skip; 1102 1103 err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid, 1104 cb->nlh->nlmsg_seq, RTM_NEWRULE, 1105 NLM_F_MULTI, ops); 1106 if (err) 1107 break; 1108 skip: 1109 idx++; 1110 } 1111 rcu_read_unlock(); 1112 cb->args[1] = idx; 1113 rules_ops_put(ops); 1114 1115 return err; 1116 } 1117 1118 static int fib_valid_dumprule_req(const struct nlmsghdr *nlh, 1119 struct netlink_ext_ack *extack) 1120 { 1121 struct fib_rule_hdr *frh; 1122 1123 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { 1124 NL_SET_ERR_MSG(extack, "Invalid header for fib rule dump request"); 1125 return -EINVAL; 1126 } 1127 1128 frh = nlmsg_data(nlh); 1129 if (frh->dst_len || frh->src_len || frh->tos || frh->table || 1130 frh->res1 || frh->res2 || frh->action || frh->flags) { 1131 NL_SET_ERR_MSG(extack, 1132 "Invalid values in header for fib rule dump request"); 1133 return -EINVAL; 1134 } 1135 1136 if (nlmsg_attrlen(nlh, sizeof(*frh))) { 1137 NL_SET_ERR_MSG(extack, "Invalid data after header in fib rule dump request"); 1138 return -EINVAL; 1139 } 1140 1141 return 0; 1142 } 1143 1144 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb) 1145 { 1146 const struct nlmsghdr *nlh = cb->nlh; 1147 struct net *net = sock_net(skb->sk); 1148 struct fib_rules_ops *ops; 1149 int err, idx = 0, family; 1150 1151 if (cb->strict_check) { 1152 err = fib_valid_dumprule_req(nlh, cb->extack); 1153 1154 if (err < 0) 1155 return err; 1156 } 1157 1158 family = rtnl_msg_family(nlh); 1159 if (family != AF_UNSPEC) { 1160 /* Protocol specific dump request */ 1161 ops = lookup_rules_ops(net, family); 1162 if (ops == NULL) 1163 return -EAFNOSUPPORT; 1164 1165 return dump_rules(skb, cb, ops); 1166 } 1167 1168 err = 0; 1169 rcu_read_lock(); 1170 list_for_each_entry_rcu(ops, &net->rules_ops, list) { 1171 if (idx < cb->args[0] || !try_module_get(ops->owner)) 1172 goto skip; 1173 1174 err = dump_rules(skb, cb, ops); 1175 if (err < 0) 1176 break; 1177 1178 cb->args[1] = 0; 1179 skip: 1180 idx++; 1181 } 1182 rcu_read_unlock(); 1183 cb->args[0] = idx; 1184 1185 return err; 1186 } 1187 1188 static void notify_rule_change(int event, struct fib_rule *rule, 1189 struct fib_rules_ops *ops, struct nlmsghdr *nlh, 1190 u32 pid) 1191 { 1192 struct net *net; 1193 struct sk_buff *skb; 1194 int err = -ENOMEM; 1195 1196 net = ops->fro_net; 1197 skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL); 1198 if (skb == NULL) 1199 goto errout; 1200 1201 err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops); 1202 if (err < 0) { 1203 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */ 1204 WARN_ON(err == -EMSGSIZE); 1205 kfree_skb(skb); 1206 goto errout; 1207 } 1208 1209 rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL); 1210 return; 1211 errout: 1212 rtnl_set_sk_err(net, ops->nlgroup, err); 1213 } 1214 1215 static void attach_rules(struct list_head *rules, struct net_device *dev) 1216 { 1217 struct fib_rule *rule; 1218 1219 list_for_each_entry(rule, rules, list) { 1220 if (rule->iifindex == -1 && 1221 strcmp(dev->name, rule->iifname) == 0) 1222 rule->iifindex = dev->ifindex; 1223 if (rule->oifindex == -1 && 1224 strcmp(dev->name, rule->oifname) == 0) 1225 rule->oifindex = dev->ifindex; 1226 } 1227 } 1228 1229 static void detach_rules(struct list_head *rules, struct net_device *dev) 1230 { 1231 struct fib_rule *rule; 1232 1233 list_for_each_entry(rule, rules, list) { 1234 if (rule->iifindex == dev->ifindex) 1235 rule->iifindex = -1; 1236 if (rule->oifindex == dev->ifindex) 1237 rule->oifindex = -1; 1238 } 1239 } 1240 1241 1242 static int fib_rules_event(struct notifier_block *this, unsigned long event, 1243 void *ptr) 1244 { 1245 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1246 struct net *net = dev_net(dev); 1247 struct fib_rules_ops *ops; 1248 1249 ASSERT_RTNL(); 1250 1251 switch (event) { 1252 case NETDEV_REGISTER: 1253 list_for_each_entry(ops, &net->rules_ops, list) 1254 attach_rules(&ops->rules_list, dev); 1255 break; 1256 1257 case NETDEV_CHANGENAME: 1258 list_for_each_entry(ops, &net->rules_ops, list) { 1259 detach_rules(&ops->rules_list, dev); 1260 attach_rules(&ops->rules_list, dev); 1261 } 1262 break; 1263 1264 case NETDEV_UNREGISTER: 1265 list_for_each_entry(ops, &net->rules_ops, list) 1266 detach_rules(&ops->rules_list, dev); 1267 break; 1268 } 1269 1270 return NOTIFY_DONE; 1271 } 1272 1273 static struct notifier_block fib_rules_notifier = { 1274 .notifier_call = fib_rules_event, 1275 }; 1276 1277 static int __net_init fib_rules_net_init(struct net *net) 1278 { 1279 INIT_LIST_HEAD(&net->rules_ops); 1280 spin_lock_init(&net->rules_mod_lock); 1281 return 0; 1282 } 1283 1284 static void __net_exit fib_rules_net_exit(struct net *net) 1285 { 1286 WARN_ON_ONCE(!list_empty(&net->rules_ops)); 1287 } 1288 1289 static struct pernet_operations fib_rules_net_ops = { 1290 .init = fib_rules_net_init, 1291 .exit = fib_rules_net_exit, 1292 }; 1293 1294 static const struct rtnl_msg_handler fib_rules_rtnl_msg_handlers[] __initconst = { 1295 {.msgtype = RTM_NEWRULE, .doit = fib_nl_newrule}, 1296 {.msgtype = RTM_DELRULE, .doit = fib_nl_delrule}, 1297 {.msgtype = RTM_GETRULE, .dumpit = fib_nl_dumprule, 1298 .flags = RTNL_FLAG_DUMP_UNLOCKED}, 1299 }; 1300 1301 static int __init fib_rules_init(void) 1302 { 1303 int err; 1304 1305 rtnl_register_many(fib_rules_rtnl_msg_handlers); 1306 1307 err = register_pernet_subsys(&fib_rules_net_ops); 1308 if (err < 0) 1309 goto fail; 1310 1311 err = register_netdevice_notifier(&fib_rules_notifier); 1312 if (err < 0) 1313 goto fail_unregister; 1314 1315 return 0; 1316 1317 fail_unregister: 1318 unregister_pernet_subsys(&fib_rules_net_ops); 1319 fail: 1320 rtnl_unregister_many(fib_rules_rtnl_msg_handlers); 1321 return err; 1322 } 1323 1324 subsys_initcall(fib_rules_init); 1325