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 = nla_get_u8_default(tb[FRA_PROTOCOL], RTPROT_UNSPEC); 562 563 if (tb[FRA_IIFNAME]) { 564 struct net_device *dev; 565 566 nlrule->iifindex = -1; 567 nla_strscpy(nlrule->iifname, tb[FRA_IIFNAME], IFNAMSIZ); 568 dev = __dev_get_by_name(net, nlrule->iifname); 569 if (dev) 570 nlrule->iifindex = dev->ifindex; 571 } 572 573 if (tb[FRA_OIFNAME]) { 574 struct net_device *dev; 575 576 nlrule->oifindex = -1; 577 nla_strscpy(nlrule->oifname, tb[FRA_OIFNAME], IFNAMSIZ); 578 dev = __dev_get_by_name(net, nlrule->oifname); 579 if (dev) 580 nlrule->oifindex = dev->ifindex; 581 } 582 583 if (tb[FRA_FWMARK]) { 584 nlrule->mark = nla_get_u32(tb[FRA_FWMARK]); 585 if (nlrule->mark) 586 /* compatibility: if the mark value is non-zero all bits 587 * are compared unless a mask is explicitly specified. 588 */ 589 nlrule->mark_mask = 0xFFFFFFFF; 590 } 591 592 if (tb[FRA_FWMASK]) 593 nlrule->mark_mask = nla_get_u32(tb[FRA_FWMASK]); 594 595 if (tb[FRA_TUN_ID]) 596 nlrule->tun_id = nla_get_be64(tb[FRA_TUN_ID]); 597 598 if (tb[FRA_L3MDEV] && 599 fib_nl2rule_l3mdev(tb[FRA_L3MDEV], nlrule, extack) < 0) 600 goto errout_free; 601 602 nlrule->action = frh->action; 603 nlrule->flags = frh->flags; 604 nlrule->table = frh_get_table(frh, tb); 605 if (tb[FRA_SUPPRESS_PREFIXLEN]) 606 nlrule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]); 607 else 608 nlrule->suppress_prefixlen = -1; 609 610 if (tb[FRA_SUPPRESS_IFGROUP]) 611 nlrule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]); 612 else 613 nlrule->suppress_ifgroup = -1; 614 615 if (tb[FRA_GOTO]) { 616 if (nlrule->action != FR_ACT_GOTO) { 617 NL_SET_ERR_MSG(extack, "Unexpected goto"); 618 goto errout_free; 619 } 620 621 nlrule->target = nla_get_u32(tb[FRA_GOTO]); 622 /* Backward jumps are prohibited to avoid endless loops */ 623 if (nlrule->target <= nlrule->pref) { 624 NL_SET_ERR_MSG(extack, "Backward goto not supported"); 625 goto errout_free; 626 } 627 } else if (nlrule->action == FR_ACT_GOTO) { 628 NL_SET_ERR_MSG(extack, "Missing goto target for action goto"); 629 goto errout_free; 630 } 631 632 if (nlrule->l3mdev && nlrule->table) { 633 NL_SET_ERR_MSG(extack, "l3mdev and table are mutually exclusive"); 634 goto errout_free; 635 } 636 637 if (tb[FRA_UID_RANGE]) { 638 if (current_user_ns() != net->user_ns) { 639 err = -EPERM; 640 NL_SET_ERR_MSG(extack, "No permission to set uid"); 641 goto errout_free; 642 } 643 644 nlrule->uid_range = nla_get_kuid_range(tb); 645 646 if (!uid_range_set(&nlrule->uid_range) || 647 !uid_lte(nlrule->uid_range.start, nlrule->uid_range.end)) { 648 NL_SET_ERR_MSG(extack, "Invalid uid range"); 649 goto errout_free; 650 } 651 } else { 652 nlrule->uid_range = fib_kuid_range_unset; 653 } 654 655 if (tb[FRA_IP_PROTO]) 656 nlrule->ip_proto = nla_get_u8(tb[FRA_IP_PROTO]); 657 658 if (tb[FRA_SPORT_RANGE]) { 659 err = nla_get_port_range(tb[FRA_SPORT_RANGE], 660 &nlrule->sport_range); 661 if (err) { 662 NL_SET_ERR_MSG(extack, "Invalid sport range"); 663 goto errout_free; 664 } 665 } 666 667 if (tb[FRA_DPORT_RANGE]) { 668 err = nla_get_port_range(tb[FRA_DPORT_RANGE], 669 &nlrule->dport_range); 670 if (err) { 671 NL_SET_ERR_MSG(extack, "Invalid dport range"); 672 goto errout_free; 673 } 674 } 675 676 *rule = nlrule; 677 678 return 0; 679 680 errout_free: 681 kfree(nlrule); 682 errout: 683 return err; 684 } 685 686 static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh, 687 struct nlattr **tb, struct fib_rule *rule) 688 { 689 struct fib_rule *r; 690 691 list_for_each_entry(r, &ops->rules_list, list) { 692 if (r->action != rule->action) 693 continue; 694 695 if (r->table != rule->table) 696 continue; 697 698 if (r->pref != rule->pref) 699 continue; 700 701 if (memcmp(r->iifname, rule->iifname, IFNAMSIZ)) 702 continue; 703 704 if (memcmp(r->oifname, rule->oifname, IFNAMSIZ)) 705 continue; 706 707 if (r->mark != rule->mark) 708 continue; 709 710 if (r->suppress_ifgroup != rule->suppress_ifgroup) 711 continue; 712 713 if (r->suppress_prefixlen != rule->suppress_prefixlen) 714 continue; 715 716 if (r->mark_mask != rule->mark_mask) 717 continue; 718 719 if (r->tun_id != rule->tun_id) 720 continue; 721 722 if (r->fr_net != rule->fr_net) 723 continue; 724 725 if (r->l3mdev != rule->l3mdev) 726 continue; 727 728 if (!uid_eq(r->uid_range.start, rule->uid_range.start) || 729 !uid_eq(r->uid_range.end, rule->uid_range.end)) 730 continue; 731 732 if (r->ip_proto != rule->ip_proto) 733 continue; 734 735 if (r->proto != rule->proto) 736 continue; 737 738 if (!fib_rule_port_range_compare(&r->sport_range, 739 &rule->sport_range)) 740 continue; 741 742 if (!fib_rule_port_range_compare(&r->dport_range, 743 &rule->dport_range)) 744 continue; 745 746 if (!ops->compare(r, frh, tb)) 747 continue; 748 return 1; 749 } 750 return 0; 751 } 752 753 static const struct nla_policy fib_rule_policy[FRA_MAX + 1] = { 754 [FRA_UNSPEC] = { .strict_start_type = FRA_DPORT_RANGE + 1 }, 755 [FRA_IIFNAME] = { .type = NLA_STRING, .len = IFNAMSIZ - 1 }, 756 [FRA_OIFNAME] = { .type = NLA_STRING, .len = IFNAMSIZ - 1 }, 757 [FRA_PRIORITY] = { .type = NLA_U32 }, 758 [FRA_FWMARK] = { .type = NLA_U32 }, 759 [FRA_FLOW] = { .type = NLA_U32 }, 760 [FRA_TUN_ID] = { .type = NLA_U64 }, 761 [FRA_FWMASK] = { .type = NLA_U32 }, 762 [FRA_TABLE] = { .type = NLA_U32 }, 763 [FRA_SUPPRESS_PREFIXLEN] = { .type = NLA_U32 }, 764 [FRA_SUPPRESS_IFGROUP] = { .type = NLA_U32 }, 765 [FRA_GOTO] = { .type = NLA_U32 }, 766 [FRA_L3MDEV] = { .type = NLA_U8 }, 767 [FRA_UID_RANGE] = { .len = sizeof(struct fib_rule_uid_range) }, 768 [FRA_PROTOCOL] = { .type = NLA_U8 }, 769 [FRA_IP_PROTO] = { .type = NLA_U8 }, 770 [FRA_SPORT_RANGE] = { .len = sizeof(struct fib_rule_port_range) }, 771 [FRA_DPORT_RANGE] = { .len = sizeof(struct fib_rule_port_range) }, 772 [FRA_DSCP] = NLA_POLICY_MAX(NLA_U8, INET_DSCP_MASK >> 2), 773 [FRA_FLOWLABEL] = { .type = NLA_BE32 }, 774 [FRA_FLOWLABEL_MASK] = { .type = NLA_BE32 }, 775 }; 776 777 int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh, 778 struct netlink_ext_ack *extack) 779 { 780 struct net *net = sock_net(skb->sk); 781 struct fib_rule_hdr *frh = nlmsg_data(nlh); 782 struct fib_rules_ops *ops = NULL; 783 struct fib_rule *rule = NULL, *r, *last = NULL; 784 struct nlattr *tb[FRA_MAX + 1]; 785 int err = -EINVAL, unresolved = 0; 786 bool user_priority = false; 787 788 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { 789 NL_SET_ERR_MSG(extack, "Invalid msg length"); 790 goto errout; 791 } 792 793 ops = lookup_rules_ops(net, frh->family); 794 if (!ops) { 795 err = -EAFNOSUPPORT; 796 NL_SET_ERR_MSG(extack, "Rule family not supported"); 797 goto errout; 798 } 799 800 err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX, 801 fib_rule_policy, extack); 802 if (err < 0) { 803 NL_SET_ERR_MSG(extack, "Error parsing msg"); 804 goto errout; 805 } 806 807 err = fib_nl2rule(skb, nlh, extack, ops, tb, &rule, &user_priority); 808 if (err) 809 goto errout; 810 811 if ((nlh->nlmsg_flags & NLM_F_EXCL) && 812 rule_exists(ops, frh, tb, rule)) { 813 err = -EEXIST; 814 goto errout_free; 815 } 816 817 err = ops->configure(rule, skb, frh, tb, extack); 818 if (err < 0) 819 goto errout_free; 820 821 err = call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops, 822 extack); 823 if (err < 0) 824 goto errout_free; 825 826 list_for_each_entry(r, &ops->rules_list, list) { 827 if (r->pref == rule->target) { 828 RCU_INIT_POINTER(rule->ctarget, r); 829 break; 830 } 831 } 832 833 if (rcu_dereference_protected(rule->ctarget, 1) == NULL) 834 unresolved = 1; 835 836 list_for_each_entry(r, &ops->rules_list, list) { 837 if (r->pref > rule->pref) 838 break; 839 last = r; 840 } 841 842 if (last) 843 list_add_rcu(&rule->list, &last->list); 844 else 845 list_add_rcu(&rule->list, &ops->rules_list); 846 847 if (ops->unresolved_rules) { 848 /* 849 * There are unresolved goto rules in the list, check if 850 * any of them are pointing to this new rule. 851 */ 852 list_for_each_entry(r, &ops->rules_list, list) { 853 if (r->action == FR_ACT_GOTO && 854 r->target == rule->pref && 855 rtnl_dereference(r->ctarget) == NULL) { 856 rcu_assign_pointer(r->ctarget, rule); 857 if (--ops->unresolved_rules == 0) 858 break; 859 } 860 } 861 } 862 863 if (rule->action == FR_ACT_GOTO) 864 ops->nr_goto_rules++; 865 866 if (unresolved) 867 ops->unresolved_rules++; 868 869 if (rule->tun_id) 870 ip_tunnel_need_metadata(); 871 872 notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid); 873 flush_route_cache(ops); 874 rules_ops_put(ops); 875 return 0; 876 877 errout_free: 878 kfree(rule); 879 errout: 880 rules_ops_put(ops); 881 return err; 882 } 883 EXPORT_SYMBOL_GPL(fib_nl_newrule); 884 885 int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh, 886 struct netlink_ext_ack *extack) 887 { 888 struct net *net = sock_net(skb->sk); 889 struct fib_rule_hdr *frh = nlmsg_data(nlh); 890 struct fib_rules_ops *ops = NULL; 891 struct fib_rule *rule = NULL, *r, *nlrule = NULL; 892 struct nlattr *tb[FRA_MAX+1]; 893 int err = -EINVAL; 894 bool user_priority = false; 895 896 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { 897 NL_SET_ERR_MSG(extack, "Invalid msg length"); 898 goto errout; 899 } 900 901 ops = lookup_rules_ops(net, frh->family); 902 if (ops == NULL) { 903 err = -EAFNOSUPPORT; 904 NL_SET_ERR_MSG(extack, "Rule family not supported"); 905 goto errout; 906 } 907 908 err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX, 909 fib_rule_policy, extack); 910 if (err < 0) { 911 NL_SET_ERR_MSG(extack, "Error parsing msg"); 912 goto errout; 913 } 914 915 err = fib_nl2rule(skb, nlh, extack, ops, tb, &nlrule, &user_priority); 916 if (err) 917 goto errout; 918 919 rule = rule_find(ops, frh, tb, nlrule, user_priority); 920 if (!rule) { 921 err = -ENOENT; 922 goto errout; 923 } 924 925 if (rule->flags & FIB_RULE_PERMANENT) { 926 err = -EPERM; 927 goto errout; 928 } 929 930 if (ops->delete) { 931 err = ops->delete(rule); 932 if (err) 933 goto errout; 934 } 935 936 if (rule->tun_id) 937 ip_tunnel_unneed_metadata(); 938 939 list_del_rcu(&rule->list); 940 941 if (rule->action == FR_ACT_GOTO) { 942 ops->nr_goto_rules--; 943 if (rtnl_dereference(rule->ctarget) == NULL) 944 ops->unresolved_rules--; 945 } 946 947 /* 948 * Check if this rule is a target to any of them. If so, 949 * adjust to the next one with the same preference or 950 * disable them. As this operation is eventually very 951 * expensive, it is only performed if goto rules, except 952 * current if it is goto rule, have actually been added. 953 */ 954 if (ops->nr_goto_rules > 0) { 955 struct fib_rule *n; 956 957 n = list_next_entry(rule, list); 958 if (&n->list == &ops->rules_list || n->pref != rule->pref) 959 n = NULL; 960 list_for_each_entry(r, &ops->rules_list, list) { 961 if (rtnl_dereference(r->ctarget) != rule) 962 continue; 963 rcu_assign_pointer(r->ctarget, n); 964 if (!n) 965 ops->unresolved_rules++; 966 } 967 } 968 969 call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops, 970 NULL); 971 notify_rule_change(RTM_DELRULE, rule, ops, nlh, 972 NETLINK_CB(skb).portid); 973 fib_rule_put(rule); 974 flush_route_cache(ops); 975 rules_ops_put(ops); 976 kfree(nlrule); 977 return 0; 978 979 errout: 980 kfree(nlrule); 981 rules_ops_put(ops); 982 return err; 983 } 984 EXPORT_SYMBOL_GPL(fib_nl_delrule); 985 986 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops, 987 struct fib_rule *rule) 988 { 989 size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr)) 990 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */ 991 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */ 992 + nla_total_size(4) /* FRA_PRIORITY */ 993 + nla_total_size(4) /* FRA_TABLE */ 994 + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */ 995 + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */ 996 + nla_total_size(4) /* FRA_FWMARK */ 997 + nla_total_size(4) /* FRA_FWMASK */ 998 + nla_total_size_64bit(8) /* FRA_TUN_ID */ 999 + nla_total_size(sizeof(struct fib_kuid_range)) 1000 + nla_total_size(1) /* FRA_PROTOCOL */ 1001 + nla_total_size(1) /* FRA_IP_PROTO */ 1002 + nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_SPORT_RANGE */ 1003 + nla_total_size(sizeof(struct fib_rule_port_range)); /* FRA_DPORT_RANGE */ 1004 1005 if (ops->nlmsg_payload) 1006 payload += ops->nlmsg_payload(rule); 1007 1008 return payload; 1009 } 1010 1011 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule, 1012 u32 pid, u32 seq, int type, int flags, 1013 struct fib_rules_ops *ops) 1014 { 1015 struct nlmsghdr *nlh; 1016 struct fib_rule_hdr *frh; 1017 1018 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags); 1019 if (nlh == NULL) 1020 return -EMSGSIZE; 1021 1022 frh = nlmsg_data(nlh); 1023 frh->family = ops->family; 1024 frh->table = rule->table < 256 ? rule->table : RT_TABLE_COMPAT; 1025 if (nla_put_u32(skb, FRA_TABLE, rule->table)) 1026 goto nla_put_failure; 1027 if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen)) 1028 goto nla_put_failure; 1029 frh->res1 = 0; 1030 frh->res2 = 0; 1031 frh->action = rule->action; 1032 frh->flags = rule->flags; 1033 1034 if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto)) 1035 goto nla_put_failure; 1036 1037 if (rule->action == FR_ACT_GOTO && 1038 rcu_access_pointer(rule->ctarget) == NULL) 1039 frh->flags |= FIB_RULE_UNRESOLVED; 1040 1041 if (rule->iifname[0]) { 1042 if (nla_put_string(skb, FRA_IIFNAME, rule->iifname)) 1043 goto nla_put_failure; 1044 if (rule->iifindex == -1) 1045 frh->flags |= FIB_RULE_IIF_DETACHED; 1046 } 1047 1048 if (rule->oifname[0]) { 1049 if (nla_put_string(skb, FRA_OIFNAME, rule->oifname)) 1050 goto nla_put_failure; 1051 if (rule->oifindex == -1) 1052 frh->flags |= FIB_RULE_OIF_DETACHED; 1053 } 1054 1055 if ((rule->pref && 1056 nla_put_u32(skb, FRA_PRIORITY, rule->pref)) || 1057 (rule->mark && 1058 nla_put_u32(skb, FRA_FWMARK, rule->mark)) || 1059 ((rule->mark_mask || rule->mark) && 1060 nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) || 1061 (rule->target && 1062 nla_put_u32(skb, FRA_GOTO, rule->target)) || 1063 (rule->tun_id && 1064 nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) || 1065 (rule->l3mdev && 1066 nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) || 1067 (uid_range_set(&rule->uid_range) && 1068 nla_put_uid_range(skb, &rule->uid_range)) || 1069 (fib_rule_port_range_set(&rule->sport_range) && 1070 nla_put_port_range(skb, FRA_SPORT_RANGE, &rule->sport_range)) || 1071 (fib_rule_port_range_set(&rule->dport_range) && 1072 nla_put_port_range(skb, FRA_DPORT_RANGE, &rule->dport_range)) || 1073 (rule->ip_proto && nla_put_u8(skb, FRA_IP_PROTO, rule->ip_proto))) 1074 goto nla_put_failure; 1075 1076 if (rule->suppress_ifgroup != -1) { 1077 if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup)) 1078 goto nla_put_failure; 1079 } 1080 1081 if (ops->fill(rule, skb, frh) < 0) 1082 goto nla_put_failure; 1083 1084 nlmsg_end(skb, nlh); 1085 return 0; 1086 1087 nla_put_failure: 1088 nlmsg_cancel(skb, nlh); 1089 return -EMSGSIZE; 1090 } 1091 1092 static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb, 1093 struct fib_rules_ops *ops) 1094 { 1095 int idx = 0; 1096 struct fib_rule *rule; 1097 int err = 0; 1098 1099 rcu_read_lock(); 1100 list_for_each_entry_rcu(rule, &ops->rules_list, list) { 1101 if (idx < cb->args[1]) 1102 goto skip; 1103 1104 err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid, 1105 cb->nlh->nlmsg_seq, RTM_NEWRULE, 1106 NLM_F_MULTI, ops); 1107 if (err) 1108 break; 1109 skip: 1110 idx++; 1111 } 1112 rcu_read_unlock(); 1113 cb->args[1] = idx; 1114 rules_ops_put(ops); 1115 1116 return err; 1117 } 1118 1119 static int fib_valid_dumprule_req(const struct nlmsghdr *nlh, 1120 struct netlink_ext_ack *extack) 1121 { 1122 struct fib_rule_hdr *frh; 1123 1124 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { 1125 NL_SET_ERR_MSG(extack, "Invalid header for fib rule dump request"); 1126 return -EINVAL; 1127 } 1128 1129 frh = nlmsg_data(nlh); 1130 if (frh->dst_len || frh->src_len || frh->tos || frh->table || 1131 frh->res1 || frh->res2 || frh->action || frh->flags) { 1132 NL_SET_ERR_MSG(extack, 1133 "Invalid values in header for fib rule dump request"); 1134 return -EINVAL; 1135 } 1136 1137 if (nlmsg_attrlen(nlh, sizeof(*frh))) { 1138 NL_SET_ERR_MSG(extack, "Invalid data after header in fib rule dump request"); 1139 return -EINVAL; 1140 } 1141 1142 return 0; 1143 } 1144 1145 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb) 1146 { 1147 const struct nlmsghdr *nlh = cb->nlh; 1148 struct net *net = sock_net(skb->sk); 1149 struct fib_rules_ops *ops; 1150 int err, idx = 0, family; 1151 1152 if (cb->strict_check) { 1153 err = fib_valid_dumprule_req(nlh, cb->extack); 1154 1155 if (err < 0) 1156 return err; 1157 } 1158 1159 family = rtnl_msg_family(nlh); 1160 if (family != AF_UNSPEC) { 1161 /* Protocol specific dump request */ 1162 ops = lookup_rules_ops(net, family); 1163 if (ops == NULL) 1164 return -EAFNOSUPPORT; 1165 1166 return dump_rules(skb, cb, ops); 1167 } 1168 1169 err = 0; 1170 rcu_read_lock(); 1171 list_for_each_entry_rcu(ops, &net->rules_ops, list) { 1172 if (idx < cb->args[0] || !try_module_get(ops->owner)) 1173 goto skip; 1174 1175 err = dump_rules(skb, cb, ops); 1176 if (err < 0) 1177 break; 1178 1179 cb->args[1] = 0; 1180 skip: 1181 idx++; 1182 } 1183 rcu_read_unlock(); 1184 cb->args[0] = idx; 1185 1186 return err; 1187 } 1188 1189 static void notify_rule_change(int event, struct fib_rule *rule, 1190 struct fib_rules_ops *ops, struct nlmsghdr *nlh, 1191 u32 pid) 1192 { 1193 struct net *net; 1194 struct sk_buff *skb; 1195 int err = -ENOMEM; 1196 1197 net = ops->fro_net; 1198 skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL); 1199 if (skb == NULL) 1200 goto errout; 1201 1202 err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops); 1203 if (err < 0) { 1204 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */ 1205 WARN_ON(err == -EMSGSIZE); 1206 kfree_skb(skb); 1207 goto errout; 1208 } 1209 1210 rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL); 1211 return; 1212 errout: 1213 rtnl_set_sk_err(net, ops->nlgroup, err); 1214 } 1215 1216 static void attach_rules(struct list_head *rules, struct net_device *dev) 1217 { 1218 struct fib_rule *rule; 1219 1220 list_for_each_entry(rule, rules, list) { 1221 if (rule->iifindex == -1 && 1222 strcmp(dev->name, rule->iifname) == 0) 1223 rule->iifindex = dev->ifindex; 1224 if (rule->oifindex == -1 && 1225 strcmp(dev->name, rule->oifname) == 0) 1226 rule->oifindex = dev->ifindex; 1227 } 1228 } 1229 1230 static void detach_rules(struct list_head *rules, struct net_device *dev) 1231 { 1232 struct fib_rule *rule; 1233 1234 list_for_each_entry(rule, rules, list) { 1235 if (rule->iifindex == dev->ifindex) 1236 rule->iifindex = -1; 1237 if (rule->oifindex == dev->ifindex) 1238 rule->oifindex = -1; 1239 } 1240 } 1241 1242 1243 static int fib_rules_event(struct notifier_block *this, unsigned long event, 1244 void *ptr) 1245 { 1246 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1247 struct net *net = dev_net(dev); 1248 struct fib_rules_ops *ops; 1249 1250 ASSERT_RTNL(); 1251 1252 switch (event) { 1253 case NETDEV_REGISTER: 1254 list_for_each_entry(ops, &net->rules_ops, list) 1255 attach_rules(&ops->rules_list, dev); 1256 break; 1257 1258 case NETDEV_CHANGENAME: 1259 list_for_each_entry(ops, &net->rules_ops, list) { 1260 detach_rules(&ops->rules_list, dev); 1261 attach_rules(&ops->rules_list, dev); 1262 } 1263 break; 1264 1265 case NETDEV_UNREGISTER: 1266 list_for_each_entry(ops, &net->rules_ops, list) 1267 detach_rules(&ops->rules_list, dev); 1268 break; 1269 } 1270 1271 return NOTIFY_DONE; 1272 } 1273 1274 static struct notifier_block fib_rules_notifier = { 1275 .notifier_call = fib_rules_event, 1276 }; 1277 1278 static int __net_init fib_rules_net_init(struct net *net) 1279 { 1280 INIT_LIST_HEAD(&net->rules_ops); 1281 spin_lock_init(&net->rules_mod_lock); 1282 return 0; 1283 } 1284 1285 static void __net_exit fib_rules_net_exit(struct net *net) 1286 { 1287 WARN_ON_ONCE(!list_empty(&net->rules_ops)); 1288 } 1289 1290 static struct pernet_operations fib_rules_net_ops = { 1291 .init = fib_rules_net_init, 1292 .exit = fib_rules_net_exit, 1293 }; 1294 1295 static const struct rtnl_msg_handler fib_rules_rtnl_msg_handlers[] __initconst = { 1296 {.msgtype = RTM_NEWRULE, .doit = fib_nl_newrule}, 1297 {.msgtype = RTM_DELRULE, .doit = fib_nl_delrule}, 1298 {.msgtype = RTM_GETRULE, .dumpit = fib_nl_dumprule, 1299 .flags = RTNL_FLAG_DUMP_UNLOCKED}, 1300 }; 1301 1302 static int __init fib_rules_init(void) 1303 { 1304 int err; 1305 1306 rtnl_register_many(fib_rules_rtnl_msg_handlers); 1307 1308 err = register_pernet_subsys(&fib_rules_net_ops); 1309 if (err < 0) 1310 goto fail; 1311 1312 err = register_netdevice_notifier(&fib_rules_notifier); 1313 if (err < 0) 1314 goto fail_unregister; 1315 1316 return 0; 1317 1318 fail_unregister: 1319 unregister_pernet_subsys(&fib_rules_net_ops); 1320 fail: 1321 rtnl_unregister_many(fib_rules_rtnl_msg_handlers); 1322 return err; 1323 } 1324 1325 subsys_initcall(fib_rules_init); 1326