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 (READ_ONCE(rule->iifindex) || READ_ONCE(rule->oifindex) || 41 rule->mark || rule->tun_id || 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 iifindex, oifindex, ret = 0; 265 266 iifindex = READ_ONCE(rule->iifindex); 267 if (iifindex && (iifindex != fl->flowi_iif)) 268 goto out; 269 270 oifindex = READ_ONCE(rule->oifindex); 271 if (oifindex && (oifindex != fl->flowi_oif)) 272 goto out; 273 274 if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask) 275 goto out; 276 277 if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id)) 278 goto out; 279 280 if (rule->l3mdev && !l3mdev_fib_rule_match(rule->fr_net, fl, arg)) 281 goto out; 282 283 if (uid_lt(fl->flowi_uid, rule->uid_range.start) || 284 uid_gt(fl->flowi_uid, rule->uid_range.end)) 285 goto out; 286 287 ret = INDIRECT_CALL_MT(ops->match, 288 fib6_rule_match, 289 fib4_rule_match, 290 rule, fl, flags); 291 out: 292 return (rule->flags & FIB_RULE_INVERT) ? !ret : ret; 293 } 294 295 int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl, 296 int flags, struct fib_lookup_arg *arg) 297 { 298 struct fib_rule *rule; 299 int err; 300 301 rcu_read_lock(); 302 303 list_for_each_entry_rcu(rule, &ops->rules_list, list) { 304 jumped: 305 if (!fib_rule_match(rule, ops, fl, flags, arg)) 306 continue; 307 308 if (rule->action == FR_ACT_GOTO) { 309 struct fib_rule *target; 310 311 target = rcu_dereference(rule->ctarget); 312 if (target == NULL) { 313 continue; 314 } else { 315 rule = target; 316 goto jumped; 317 } 318 } else if (rule->action == FR_ACT_NOP) 319 continue; 320 else 321 err = INDIRECT_CALL_MT(ops->action, 322 fib6_rule_action, 323 fib4_rule_action, 324 rule, fl, flags, arg); 325 326 if (!err && ops->suppress && INDIRECT_CALL_MT(ops->suppress, 327 fib6_rule_suppress, 328 fib4_rule_suppress, 329 rule, flags, arg)) 330 continue; 331 332 if (err != -EAGAIN) { 333 if ((arg->flags & FIB_LOOKUP_NOREF) || 334 likely(refcount_inc_not_zero(&rule->refcnt))) { 335 arg->rule = rule; 336 goto out; 337 } 338 break; 339 } 340 } 341 342 err = -ESRCH; 343 out: 344 rcu_read_unlock(); 345 346 return err; 347 } 348 EXPORT_SYMBOL_GPL(fib_rules_lookup); 349 350 static int call_fib_rule_notifier(struct notifier_block *nb, 351 enum fib_event_type event_type, 352 struct fib_rule *rule, int family, 353 struct netlink_ext_ack *extack) 354 { 355 struct fib_rule_notifier_info info = { 356 .info.family = family, 357 .info.extack = extack, 358 .rule = rule, 359 }; 360 361 return call_fib_notifier(nb, event_type, &info.info); 362 } 363 364 static int call_fib_rule_notifiers(struct net *net, 365 enum fib_event_type event_type, 366 struct fib_rule *rule, 367 struct fib_rules_ops *ops, 368 struct netlink_ext_ack *extack) 369 { 370 struct fib_rule_notifier_info info = { 371 .info.family = ops->family, 372 .info.extack = extack, 373 .rule = rule, 374 }; 375 376 ASSERT_RTNL(); 377 /* Paired with READ_ONCE() in fib_rules_seq() */ 378 WRITE_ONCE(ops->fib_rules_seq, ops->fib_rules_seq + 1); 379 return call_fib_notifiers(net, event_type, &info.info); 380 } 381 382 /* Called with rcu_read_lock() */ 383 int fib_rules_dump(struct net *net, struct notifier_block *nb, int family, 384 struct netlink_ext_ack *extack) 385 { 386 struct fib_rules_ops *ops; 387 struct fib_rule *rule; 388 int err = 0; 389 390 ops = lookup_rules_ops(net, family); 391 if (!ops) 392 return -EAFNOSUPPORT; 393 list_for_each_entry_rcu(rule, &ops->rules_list, list) { 394 err = call_fib_rule_notifier(nb, FIB_EVENT_RULE_ADD, 395 rule, family, extack); 396 if (err) 397 break; 398 } 399 rules_ops_put(ops); 400 401 return err; 402 } 403 EXPORT_SYMBOL_GPL(fib_rules_dump); 404 405 unsigned int fib_rules_seq_read(const struct net *net, int family) 406 { 407 unsigned int fib_rules_seq; 408 struct fib_rules_ops *ops; 409 410 ops = lookup_rules_ops(net, family); 411 if (!ops) 412 return 0; 413 /* Paired with WRITE_ONCE() in call_fib_rule_notifiers() */ 414 fib_rules_seq = READ_ONCE(ops->fib_rules_seq); 415 rules_ops_put(ops); 416 417 return fib_rules_seq; 418 } 419 EXPORT_SYMBOL_GPL(fib_rules_seq_read); 420 421 static struct fib_rule *rule_find(struct fib_rules_ops *ops, 422 struct fib_rule_hdr *frh, 423 struct nlattr **tb, 424 struct fib_rule *rule, 425 bool user_priority) 426 { 427 struct fib_rule *r; 428 429 list_for_each_entry(r, &ops->rules_list, list) { 430 if (rule->action && r->action != rule->action) 431 continue; 432 433 if (rule->table && r->table != rule->table) 434 continue; 435 436 if (user_priority && r->pref != rule->pref) 437 continue; 438 439 if (rule->iifname[0] && 440 memcmp(r->iifname, rule->iifname, IFNAMSIZ)) 441 continue; 442 443 if (rule->oifname[0] && 444 memcmp(r->oifname, rule->oifname, IFNAMSIZ)) 445 continue; 446 447 if (rule->mark && r->mark != rule->mark) 448 continue; 449 450 if (rule->suppress_ifgroup != -1 && 451 r->suppress_ifgroup != rule->suppress_ifgroup) 452 continue; 453 454 if (rule->suppress_prefixlen != -1 && 455 r->suppress_prefixlen != rule->suppress_prefixlen) 456 continue; 457 458 if (rule->mark_mask && r->mark_mask != rule->mark_mask) 459 continue; 460 461 if (rule->tun_id && r->tun_id != rule->tun_id) 462 continue; 463 464 if (r->fr_net != rule->fr_net) 465 continue; 466 467 if (rule->l3mdev && r->l3mdev != rule->l3mdev) 468 continue; 469 470 if (uid_range_set(&rule->uid_range) && 471 (!uid_eq(r->uid_range.start, rule->uid_range.start) || 472 !uid_eq(r->uid_range.end, rule->uid_range.end))) 473 continue; 474 475 if (rule->ip_proto && r->ip_proto != rule->ip_proto) 476 continue; 477 478 if (rule->proto && r->proto != rule->proto) 479 continue; 480 481 if (fib_rule_port_range_set(&rule->sport_range) && 482 !fib_rule_port_range_compare(&r->sport_range, 483 &rule->sport_range)) 484 continue; 485 486 if (fib_rule_port_range_set(&rule->dport_range) && 487 !fib_rule_port_range_compare(&r->dport_range, 488 &rule->dport_range)) 489 continue; 490 491 if (!ops->compare(r, frh, tb)) 492 continue; 493 return r; 494 } 495 496 return NULL; 497 } 498 499 #ifdef CONFIG_NET_L3_MASTER_DEV 500 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule, 501 struct netlink_ext_ack *extack) 502 { 503 nlrule->l3mdev = nla_get_u8(nla); 504 if (nlrule->l3mdev != 1) { 505 NL_SET_ERR_MSG(extack, "Invalid l3mdev attribute"); 506 return -1; 507 } 508 509 return 0; 510 } 511 #else 512 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule, 513 struct netlink_ext_ack *extack) 514 { 515 NL_SET_ERR_MSG(extack, "l3mdev support is not enabled in kernel"); 516 return -1; 517 } 518 #endif 519 520 static int fib_nl2rule(struct sk_buff *skb, struct nlmsghdr *nlh, 521 struct netlink_ext_ack *extack, 522 struct fib_rules_ops *ops, 523 struct nlattr *tb[], 524 struct fib_rule **rule, 525 bool *user_priority) 526 { 527 struct net *net = sock_net(skb->sk); 528 struct fib_rule_hdr *frh = nlmsg_data(nlh); 529 struct fib_rule *nlrule = NULL; 530 int err = -EINVAL; 531 532 if (frh->src_len) 533 if (!tb[FRA_SRC] || 534 frh->src_len > (ops->addr_size * 8) || 535 nla_len(tb[FRA_SRC]) != ops->addr_size) { 536 NL_SET_ERR_MSG(extack, "Invalid source address"); 537 goto errout; 538 } 539 540 if (frh->dst_len) 541 if (!tb[FRA_DST] || 542 frh->dst_len > (ops->addr_size * 8) || 543 nla_len(tb[FRA_DST]) != ops->addr_size) { 544 NL_SET_ERR_MSG(extack, "Invalid dst address"); 545 goto errout; 546 } 547 548 nlrule = kzalloc(ops->rule_size, GFP_KERNEL_ACCOUNT); 549 if (!nlrule) { 550 err = -ENOMEM; 551 goto errout; 552 } 553 refcount_set(&nlrule->refcnt, 1); 554 nlrule->fr_net = net; 555 556 if (tb[FRA_PRIORITY]) { 557 nlrule->pref = nla_get_u32(tb[FRA_PRIORITY]); 558 *user_priority = true; 559 } else { 560 nlrule->pref = fib_default_rule_pref(ops); 561 } 562 563 nlrule->proto = nla_get_u8_default(tb[FRA_PROTOCOL], RTPROT_UNSPEC); 564 565 if (tb[FRA_IIFNAME]) { 566 struct net_device *dev; 567 568 nlrule->iifindex = -1; 569 nla_strscpy(nlrule->iifname, tb[FRA_IIFNAME], IFNAMSIZ); 570 dev = __dev_get_by_name(net, nlrule->iifname); 571 if (dev) 572 nlrule->iifindex = dev->ifindex; 573 } 574 575 if (tb[FRA_OIFNAME]) { 576 struct net_device *dev; 577 578 nlrule->oifindex = -1; 579 nla_strscpy(nlrule->oifname, tb[FRA_OIFNAME], IFNAMSIZ); 580 dev = __dev_get_by_name(net, nlrule->oifname); 581 if (dev) 582 nlrule->oifindex = dev->ifindex; 583 } 584 585 if (tb[FRA_FWMARK]) { 586 nlrule->mark = nla_get_u32(tb[FRA_FWMARK]); 587 if (nlrule->mark) 588 /* compatibility: if the mark value is non-zero all bits 589 * are compared unless a mask is explicitly specified. 590 */ 591 nlrule->mark_mask = 0xFFFFFFFF; 592 } 593 594 if (tb[FRA_FWMASK]) 595 nlrule->mark_mask = nla_get_u32(tb[FRA_FWMASK]); 596 597 if (tb[FRA_TUN_ID]) 598 nlrule->tun_id = nla_get_be64(tb[FRA_TUN_ID]); 599 600 if (tb[FRA_L3MDEV] && 601 fib_nl2rule_l3mdev(tb[FRA_L3MDEV], nlrule, extack) < 0) 602 goto errout_free; 603 604 nlrule->action = frh->action; 605 nlrule->flags = frh->flags; 606 nlrule->table = frh_get_table(frh, tb); 607 if (tb[FRA_SUPPRESS_PREFIXLEN]) 608 nlrule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]); 609 else 610 nlrule->suppress_prefixlen = -1; 611 612 if (tb[FRA_SUPPRESS_IFGROUP]) 613 nlrule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]); 614 else 615 nlrule->suppress_ifgroup = -1; 616 617 if (tb[FRA_GOTO]) { 618 if (nlrule->action != FR_ACT_GOTO) { 619 NL_SET_ERR_MSG(extack, "Unexpected goto"); 620 goto errout_free; 621 } 622 623 nlrule->target = nla_get_u32(tb[FRA_GOTO]); 624 /* Backward jumps are prohibited to avoid endless loops */ 625 if (nlrule->target <= nlrule->pref) { 626 NL_SET_ERR_MSG(extack, "Backward goto not supported"); 627 goto errout_free; 628 } 629 } else if (nlrule->action == FR_ACT_GOTO) { 630 NL_SET_ERR_MSG(extack, "Missing goto target for action goto"); 631 goto errout_free; 632 } 633 634 if (nlrule->l3mdev && nlrule->table) { 635 NL_SET_ERR_MSG(extack, "l3mdev and table are mutually exclusive"); 636 goto errout_free; 637 } 638 639 if (tb[FRA_UID_RANGE]) { 640 if (current_user_ns() != net->user_ns) { 641 err = -EPERM; 642 NL_SET_ERR_MSG(extack, "No permission to set uid"); 643 goto errout_free; 644 } 645 646 nlrule->uid_range = nla_get_kuid_range(tb); 647 648 if (!uid_range_set(&nlrule->uid_range) || 649 !uid_lte(nlrule->uid_range.start, nlrule->uid_range.end)) { 650 NL_SET_ERR_MSG(extack, "Invalid uid range"); 651 goto errout_free; 652 } 653 } else { 654 nlrule->uid_range = fib_kuid_range_unset; 655 } 656 657 if (tb[FRA_IP_PROTO]) 658 nlrule->ip_proto = nla_get_u8(tb[FRA_IP_PROTO]); 659 660 if (tb[FRA_SPORT_RANGE]) { 661 err = nla_get_port_range(tb[FRA_SPORT_RANGE], 662 &nlrule->sport_range); 663 if (err) { 664 NL_SET_ERR_MSG(extack, "Invalid sport range"); 665 goto errout_free; 666 } 667 } 668 669 if (tb[FRA_DPORT_RANGE]) { 670 err = nla_get_port_range(tb[FRA_DPORT_RANGE], 671 &nlrule->dport_range); 672 if (err) { 673 NL_SET_ERR_MSG(extack, "Invalid dport range"); 674 goto errout_free; 675 } 676 } 677 678 *rule = nlrule; 679 680 return 0; 681 682 errout_free: 683 kfree(nlrule); 684 errout: 685 return err; 686 } 687 688 static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh, 689 struct nlattr **tb, struct fib_rule *rule) 690 { 691 struct fib_rule *r; 692 693 list_for_each_entry(r, &ops->rules_list, list) { 694 if (r->action != rule->action) 695 continue; 696 697 if (r->table != rule->table) 698 continue; 699 700 if (r->pref != rule->pref) 701 continue; 702 703 if (memcmp(r->iifname, rule->iifname, IFNAMSIZ)) 704 continue; 705 706 if (memcmp(r->oifname, rule->oifname, IFNAMSIZ)) 707 continue; 708 709 if (r->mark != rule->mark) 710 continue; 711 712 if (r->suppress_ifgroup != rule->suppress_ifgroup) 713 continue; 714 715 if (r->suppress_prefixlen != rule->suppress_prefixlen) 716 continue; 717 718 if (r->mark_mask != rule->mark_mask) 719 continue; 720 721 if (r->tun_id != rule->tun_id) 722 continue; 723 724 if (r->fr_net != rule->fr_net) 725 continue; 726 727 if (r->l3mdev != rule->l3mdev) 728 continue; 729 730 if (!uid_eq(r->uid_range.start, rule->uid_range.start) || 731 !uid_eq(r->uid_range.end, rule->uid_range.end)) 732 continue; 733 734 if (r->ip_proto != rule->ip_proto) 735 continue; 736 737 if (r->proto != rule->proto) 738 continue; 739 740 if (!fib_rule_port_range_compare(&r->sport_range, 741 &rule->sport_range)) 742 continue; 743 744 if (!fib_rule_port_range_compare(&r->dport_range, 745 &rule->dport_range)) 746 continue; 747 748 if (!ops->compare(r, frh, tb)) 749 continue; 750 return 1; 751 } 752 return 0; 753 } 754 755 static const struct nla_policy fib_rule_policy[FRA_MAX + 1] = { 756 [FRA_UNSPEC] = { .strict_start_type = FRA_DPORT_RANGE + 1 }, 757 [FRA_IIFNAME] = { .type = NLA_STRING, .len = IFNAMSIZ - 1 }, 758 [FRA_OIFNAME] = { .type = NLA_STRING, .len = IFNAMSIZ - 1 }, 759 [FRA_PRIORITY] = { .type = NLA_U32 }, 760 [FRA_FWMARK] = { .type = NLA_U32 }, 761 [FRA_FLOW] = { .type = NLA_U32 }, 762 [FRA_TUN_ID] = { .type = NLA_U64 }, 763 [FRA_FWMASK] = { .type = NLA_U32 }, 764 [FRA_TABLE] = { .type = NLA_U32 }, 765 [FRA_SUPPRESS_PREFIXLEN] = { .type = NLA_U32 }, 766 [FRA_SUPPRESS_IFGROUP] = { .type = NLA_U32 }, 767 [FRA_GOTO] = { .type = NLA_U32 }, 768 [FRA_L3MDEV] = { .type = NLA_U8 }, 769 [FRA_UID_RANGE] = { .len = sizeof(struct fib_rule_uid_range) }, 770 [FRA_PROTOCOL] = { .type = NLA_U8 }, 771 [FRA_IP_PROTO] = { .type = NLA_U8 }, 772 [FRA_SPORT_RANGE] = { .len = sizeof(struct fib_rule_port_range) }, 773 [FRA_DPORT_RANGE] = { .len = sizeof(struct fib_rule_port_range) }, 774 [FRA_DSCP] = NLA_POLICY_MAX(NLA_U8, INET_DSCP_MASK >> 2), 775 [FRA_FLOWLABEL] = { .type = NLA_BE32 }, 776 [FRA_FLOWLABEL_MASK] = { .type = NLA_BE32 }, 777 }; 778 779 int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh, 780 struct netlink_ext_ack *extack) 781 { 782 struct net *net = sock_net(skb->sk); 783 struct fib_rule_hdr *frh = nlmsg_data(nlh); 784 struct fib_rules_ops *ops = NULL; 785 struct fib_rule *rule = NULL, *r, *last = NULL; 786 struct nlattr *tb[FRA_MAX + 1]; 787 int err = -EINVAL, unresolved = 0; 788 bool user_priority = false; 789 790 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { 791 NL_SET_ERR_MSG(extack, "Invalid msg length"); 792 goto errout; 793 } 794 795 ops = lookup_rules_ops(net, frh->family); 796 if (!ops) { 797 err = -EAFNOSUPPORT; 798 NL_SET_ERR_MSG(extack, "Rule family not supported"); 799 goto errout; 800 } 801 802 err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX, 803 fib_rule_policy, extack); 804 if (err < 0) { 805 NL_SET_ERR_MSG(extack, "Error parsing msg"); 806 goto errout; 807 } 808 809 err = fib_nl2rule(skb, nlh, extack, ops, tb, &rule, &user_priority); 810 if (err) 811 goto errout; 812 813 if ((nlh->nlmsg_flags & NLM_F_EXCL) && 814 rule_exists(ops, frh, tb, rule)) { 815 err = -EEXIST; 816 goto errout_free; 817 } 818 819 err = ops->configure(rule, skb, frh, tb, extack); 820 if (err < 0) 821 goto errout_free; 822 823 err = call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops, 824 extack); 825 if (err < 0) 826 goto errout_free; 827 828 list_for_each_entry(r, &ops->rules_list, list) { 829 if (r->pref == rule->target) { 830 RCU_INIT_POINTER(rule->ctarget, r); 831 break; 832 } 833 } 834 835 if (rcu_dereference_protected(rule->ctarget, 1) == NULL) 836 unresolved = 1; 837 838 list_for_each_entry(r, &ops->rules_list, list) { 839 if (r->pref > rule->pref) 840 break; 841 last = r; 842 } 843 844 if (last) 845 list_add_rcu(&rule->list, &last->list); 846 else 847 list_add_rcu(&rule->list, &ops->rules_list); 848 849 if (ops->unresolved_rules) { 850 /* 851 * There are unresolved goto rules in the list, check if 852 * any of them are pointing to this new rule. 853 */ 854 list_for_each_entry(r, &ops->rules_list, list) { 855 if (r->action == FR_ACT_GOTO && 856 r->target == rule->pref && 857 rtnl_dereference(r->ctarget) == NULL) { 858 rcu_assign_pointer(r->ctarget, rule); 859 if (--ops->unresolved_rules == 0) 860 break; 861 } 862 } 863 } 864 865 if (rule->action == FR_ACT_GOTO) 866 ops->nr_goto_rules++; 867 868 if (unresolved) 869 ops->unresolved_rules++; 870 871 if (rule->tun_id) 872 ip_tunnel_need_metadata(); 873 874 notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid); 875 flush_route_cache(ops); 876 rules_ops_put(ops); 877 return 0; 878 879 errout_free: 880 kfree(rule); 881 errout: 882 rules_ops_put(ops); 883 return err; 884 } 885 EXPORT_SYMBOL_GPL(fib_nl_newrule); 886 887 int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh, 888 struct netlink_ext_ack *extack) 889 { 890 struct net *net = sock_net(skb->sk); 891 struct fib_rule_hdr *frh = nlmsg_data(nlh); 892 struct fib_rules_ops *ops = NULL; 893 struct fib_rule *rule = NULL, *r, *nlrule = NULL; 894 struct nlattr *tb[FRA_MAX+1]; 895 int err = -EINVAL; 896 bool user_priority = false; 897 898 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { 899 NL_SET_ERR_MSG(extack, "Invalid msg length"); 900 goto errout; 901 } 902 903 ops = lookup_rules_ops(net, frh->family); 904 if (ops == NULL) { 905 err = -EAFNOSUPPORT; 906 NL_SET_ERR_MSG(extack, "Rule family not supported"); 907 goto errout; 908 } 909 910 err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX, 911 fib_rule_policy, extack); 912 if (err < 0) { 913 NL_SET_ERR_MSG(extack, "Error parsing msg"); 914 goto errout; 915 } 916 917 err = fib_nl2rule(skb, nlh, extack, ops, tb, &nlrule, &user_priority); 918 if (err) 919 goto errout; 920 921 rule = rule_find(ops, frh, tb, nlrule, user_priority); 922 if (!rule) { 923 err = -ENOENT; 924 goto errout; 925 } 926 927 if (rule->flags & FIB_RULE_PERMANENT) { 928 err = -EPERM; 929 goto errout; 930 } 931 932 if (ops->delete) { 933 err = ops->delete(rule); 934 if (err) 935 goto errout; 936 } 937 938 if (rule->tun_id) 939 ip_tunnel_unneed_metadata(); 940 941 list_del_rcu(&rule->list); 942 943 if (rule->action == FR_ACT_GOTO) { 944 ops->nr_goto_rules--; 945 if (rtnl_dereference(rule->ctarget) == NULL) 946 ops->unresolved_rules--; 947 } 948 949 /* 950 * Check if this rule is a target to any of them. If so, 951 * adjust to the next one with the same preference or 952 * disable them. As this operation is eventually very 953 * expensive, it is only performed if goto rules, except 954 * current if it is goto rule, have actually been added. 955 */ 956 if (ops->nr_goto_rules > 0) { 957 struct fib_rule *n; 958 959 n = list_next_entry(rule, list); 960 if (&n->list == &ops->rules_list || n->pref != rule->pref) 961 n = NULL; 962 list_for_each_entry(r, &ops->rules_list, list) { 963 if (rtnl_dereference(r->ctarget) != rule) 964 continue; 965 rcu_assign_pointer(r->ctarget, n); 966 if (!n) 967 ops->unresolved_rules++; 968 } 969 } 970 971 call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops, 972 NULL); 973 notify_rule_change(RTM_DELRULE, rule, ops, nlh, 974 NETLINK_CB(skb).portid); 975 fib_rule_put(rule); 976 flush_route_cache(ops); 977 rules_ops_put(ops); 978 kfree(nlrule); 979 return 0; 980 981 errout: 982 kfree(nlrule); 983 rules_ops_put(ops); 984 return err; 985 } 986 EXPORT_SYMBOL_GPL(fib_nl_delrule); 987 988 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops, 989 struct fib_rule *rule) 990 { 991 size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr)) 992 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */ 993 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */ 994 + nla_total_size(4) /* FRA_PRIORITY */ 995 + nla_total_size(4) /* FRA_TABLE */ 996 + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */ 997 + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */ 998 + nla_total_size(4) /* FRA_FWMARK */ 999 + nla_total_size(4) /* FRA_FWMASK */ 1000 + nla_total_size_64bit(8) /* FRA_TUN_ID */ 1001 + nla_total_size(sizeof(struct fib_kuid_range)) 1002 + nla_total_size(1) /* FRA_PROTOCOL */ 1003 + nla_total_size(1) /* FRA_IP_PROTO */ 1004 + nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_SPORT_RANGE */ 1005 + nla_total_size(sizeof(struct fib_rule_port_range)); /* FRA_DPORT_RANGE */ 1006 1007 if (ops->nlmsg_payload) 1008 payload += ops->nlmsg_payload(rule); 1009 1010 return payload; 1011 } 1012 1013 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule, 1014 u32 pid, u32 seq, int type, int flags, 1015 struct fib_rules_ops *ops) 1016 { 1017 struct nlmsghdr *nlh; 1018 struct fib_rule_hdr *frh; 1019 1020 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags); 1021 if (nlh == NULL) 1022 return -EMSGSIZE; 1023 1024 frh = nlmsg_data(nlh); 1025 frh->family = ops->family; 1026 frh->table = rule->table < 256 ? rule->table : RT_TABLE_COMPAT; 1027 if (nla_put_u32(skb, FRA_TABLE, rule->table)) 1028 goto nla_put_failure; 1029 if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen)) 1030 goto nla_put_failure; 1031 frh->res1 = 0; 1032 frh->res2 = 0; 1033 frh->action = rule->action; 1034 frh->flags = rule->flags; 1035 1036 if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto)) 1037 goto nla_put_failure; 1038 1039 if (rule->action == FR_ACT_GOTO && 1040 rcu_access_pointer(rule->ctarget) == NULL) 1041 frh->flags |= FIB_RULE_UNRESOLVED; 1042 1043 if (rule->iifname[0]) { 1044 if (nla_put_string(skb, FRA_IIFNAME, rule->iifname)) 1045 goto nla_put_failure; 1046 if (READ_ONCE(rule->iifindex) == -1) 1047 frh->flags |= FIB_RULE_IIF_DETACHED; 1048 } 1049 1050 if (rule->oifname[0]) { 1051 if (nla_put_string(skb, FRA_OIFNAME, rule->oifname)) 1052 goto nla_put_failure; 1053 if (READ_ONCE(rule->oifindex) == -1) 1054 frh->flags |= FIB_RULE_OIF_DETACHED; 1055 } 1056 1057 if ((rule->pref && 1058 nla_put_u32(skb, FRA_PRIORITY, rule->pref)) || 1059 (rule->mark && 1060 nla_put_u32(skb, FRA_FWMARK, rule->mark)) || 1061 ((rule->mark_mask || rule->mark) && 1062 nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) || 1063 (rule->target && 1064 nla_put_u32(skb, FRA_GOTO, rule->target)) || 1065 (rule->tun_id && 1066 nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) || 1067 (rule->l3mdev && 1068 nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) || 1069 (uid_range_set(&rule->uid_range) && 1070 nla_put_uid_range(skb, &rule->uid_range)) || 1071 (fib_rule_port_range_set(&rule->sport_range) && 1072 nla_put_port_range(skb, FRA_SPORT_RANGE, &rule->sport_range)) || 1073 (fib_rule_port_range_set(&rule->dport_range) && 1074 nla_put_port_range(skb, FRA_DPORT_RANGE, &rule->dport_range)) || 1075 (rule->ip_proto && nla_put_u8(skb, FRA_IP_PROTO, rule->ip_proto))) 1076 goto nla_put_failure; 1077 1078 if (rule->suppress_ifgroup != -1) { 1079 if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup)) 1080 goto nla_put_failure; 1081 } 1082 1083 if (ops->fill(rule, skb, frh) < 0) 1084 goto nla_put_failure; 1085 1086 nlmsg_end(skb, nlh); 1087 return 0; 1088 1089 nla_put_failure: 1090 nlmsg_cancel(skb, nlh); 1091 return -EMSGSIZE; 1092 } 1093 1094 static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb, 1095 struct fib_rules_ops *ops) 1096 { 1097 int idx = 0; 1098 struct fib_rule *rule; 1099 int err = 0; 1100 1101 rcu_read_lock(); 1102 list_for_each_entry_rcu(rule, &ops->rules_list, list) { 1103 if (idx < cb->args[1]) 1104 goto skip; 1105 1106 err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid, 1107 cb->nlh->nlmsg_seq, RTM_NEWRULE, 1108 NLM_F_MULTI, ops); 1109 if (err) 1110 break; 1111 skip: 1112 idx++; 1113 } 1114 rcu_read_unlock(); 1115 cb->args[1] = idx; 1116 rules_ops_put(ops); 1117 1118 return err; 1119 } 1120 1121 static int fib_valid_dumprule_req(const struct nlmsghdr *nlh, 1122 struct netlink_ext_ack *extack) 1123 { 1124 struct fib_rule_hdr *frh; 1125 1126 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { 1127 NL_SET_ERR_MSG(extack, "Invalid header for fib rule dump request"); 1128 return -EINVAL; 1129 } 1130 1131 frh = nlmsg_data(nlh); 1132 if (frh->dst_len || frh->src_len || frh->tos || frh->table || 1133 frh->res1 || frh->res2 || frh->action || frh->flags) { 1134 NL_SET_ERR_MSG(extack, 1135 "Invalid values in header for fib rule dump request"); 1136 return -EINVAL; 1137 } 1138 1139 if (nlmsg_attrlen(nlh, sizeof(*frh))) { 1140 NL_SET_ERR_MSG(extack, "Invalid data after header in fib rule dump request"); 1141 return -EINVAL; 1142 } 1143 1144 return 0; 1145 } 1146 1147 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb) 1148 { 1149 const struct nlmsghdr *nlh = cb->nlh; 1150 struct net *net = sock_net(skb->sk); 1151 struct fib_rules_ops *ops; 1152 int err, idx = 0, family; 1153 1154 if (cb->strict_check) { 1155 err = fib_valid_dumprule_req(nlh, cb->extack); 1156 1157 if (err < 0) 1158 return err; 1159 } 1160 1161 family = rtnl_msg_family(nlh); 1162 if (family != AF_UNSPEC) { 1163 /* Protocol specific dump request */ 1164 ops = lookup_rules_ops(net, family); 1165 if (ops == NULL) 1166 return -EAFNOSUPPORT; 1167 1168 return dump_rules(skb, cb, ops); 1169 } 1170 1171 err = 0; 1172 rcu_read_lock(); 1173 list_for_each_entry_rcu(ops, &net->rules_ops, list) { 1174 if (idx < cb->args[0] || !try_module_get(ops->owner)) 1175 goto skip; 1176 1177 err = dump_rules(skb, cb, ops); 1178 if (err < 0) 1179 break; 1180 1181 cb->args[1] = 0; 1182 skip: 1183 idx++; 1184 } 1185 rcu_read_unlock(); 1186 cb->args[0] = idx; 1187 1188 return err; 1189 } 1190 1191 static void notify_rule_change(int event, struct fib_rule *rule, 1192 struct fib_rules_ops *ops, struct nlmsghdr *nlh, 1193 u32 pid) 1194 { 1195 struct net *net; 1196 struct sk_buff *skb; 1197 int err = -ENOMEM; 1198 1199 net = ops->fro_net; 1200 skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL); 1201 if (skb == NULL) 1202 goto errout; 1203 1204 err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops); 1205 if (err < 0) { 1206 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */ 1207 WARN_ON(err == -EMSGSIZE); 1208 kfree_skb(skb); 1209 goto errout; 1210 } 1211 1212 rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL); 1213 return; 1214 errout: 1215 rtnl_set_sk_err(net, ops->nlgroup, err); 1216 } 1217 1218 static void attach_rules(struct list_head *rules, struct net_device *dev) 1219 { 1220 struct fib_rule *rule; 1221 1222 list_for_each_entry(rule, rules, list) { 1223 if (rule->iifindex == -1 && 1224 strcmp(dev->name, rule->iifname) == 0) 1225 WRITE_ONCE(rule->iifindex, dev->ifindex); 1226 if (rule->oifindex == -1 && 1227 strcmp(dev->name, rule->oifname) == 0) 1228 WRITE_ONCE(rule->oifindex, dev->ifindex); 1229 } 1230 } 1231 1232 static void detach_rules(struct list_head *rules, struct net_device *dev) 1233 { 1234 struct fib_rule *rule; 1235 1236 list_for_each_entry(rule, rules, list) { 1237 if (rule->iifindex == dev->ifindex) 1238 WRITE_ONCE(rule->iifindex, -1); 1239 if (rule->oifindex == dev->ifindex) 1240 WRITE_ONCE(rule->oifindex, -1); 1241 } 1242 } 1243 1244 1245 static int fib_rules_event(struct notifier_block *this, unsigned long event, 1246 void *ptr) 1247 { 1248 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1249 struct net *net = dev_net(dev); 1250 struct fib_rules_ops *ops; 1251 1252 ASSERT_RTNL(); 1253 1254 switch (event) { 1255 case NETDEV_REGISTER: 1256 list_for_each_entry(ops, &net->rules_ops, list) 1257 attach_rules(&ops->rules_list, dev); 1258 break; 1259 1260 case NETDEV_CHANGENAME: 1261 list_for_each_entry(ops, &net->rules_ops, list) { 1262 detach_rules(&ops->rules_list, dev); 1263 attach_rules(&ops->rules_list, dev); 1264 } 1265 break; 1266 1267 case NETDEV_UNREGISTER: 1268 list_for_each_entry(ops, &net->rules_ops, list) 1269 detach_rules(&ops->rules_list, dev); 1270 break; 1271 } 1272 1273 return NOTIFY_DONE; 1274 } 1275 1276 static struct notifier_block fib_rules_notifier = { 1277 .notifier_call = fib_rules_event, 1278 }; 1279 1280 static int __net_init fib_rules_net_init(struct net *net) 1281 { 1282 INIT_LIST_HEAD(&net->rules_ops); 1283 spin_lock_init(&net->rules_mod_lock); 1284 return 0; 1285 } 1286 1287 static void __net_exit fib_rules_net_exit(struct net *net) 1288 { 1289 WARN_ON_ONCE(!list_empty(&net->rules_ops)); 1290 } 1291 1292 static struct pernet_operations fib_rules_net_ops = { 1293 .init = fib_rules_net_init, 1294 .exit = fib_rules_net_exit, 1295 }; 1296 1297 static const struct rtnl_msg_handler fib_rules_rtnl_msg_handlers[] __initconst = { 1298 {.msgtype = RTM_NEWRULE, .doit = fib_nl_newrule}, 1299 {.msgtype = RTM_DELRULE, .doit = fib_nl_delrule}, 1300 {.msgtype = RTM_GETRULE, .dumpit = fib_nl_dumprule, 1301 .flags = RTNL_FLAG_DUMP_UNLOCKED}, 1302 }; 1303 1304 static int __init fib_rules_init(void) 1305 { 1306 int err; 1307 1308 rtnl_register_many(fib_rules_rtnl_msg_handlers); 1309 1310 err = register_pernet_subsys(&fib_rules_net_ops); 1311 if (err < 0) 1312 goto fail; 1313 1314 err = register_netdevice_notifier(&fib_rules_notifier); 1315 if (err < 0) 1316 goto fail_unregister; 1317 1318 return 0; 1319 1320 fail_unregister: 1321 unregister_pernet_subsys(&fib_rules_net_ops); 1322 fail: 1323 rtnl_unregister_many(fib_rules_rtnl_msg_handlers); 1324 return err; 1325 } 1326 1327 subsys_initcall(fib_rules_init); 1328