1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * IPv4 Forwarding Information Base: FIB frontend. 8 * 9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 10 */ 11 12 #include <linux/module.h> 13 #include <linux/uaccess.h> 14 #include <linux/bitops.h> 15 #include <linux/capability.h> 16 #include <linux/types.h> 17 #include <linux/kernel.h> 18 #include <linux/mm.h> 19 #include <linux/string.h> 20 #include <linux/socket.h> 21 #include <linux/sockios.h> 22 #include <linux/errno.h> 23 #include <linux/in.h> 24 #include <linux/inet.h> 25 #include <linux/inetdevice.h> 26 #include <linux/netdevice.h> 27 #include <linux/if_addr.h> 28 #include <linux/if_arp.h> 29 #include <linux/skbuff.h> 30 #include <linux/cache.h> 31 #include <linux/init.h> 32 #include <linux/list.h> 33 #include <linux/slab.h> 34 35 #include <net/inet_dscp.h> 36 #include <net/ip.h> 37 #include <net/protocol.h> 38 #include <net/route.h> 39 #include <net/tcp.h> 40 #include <net/sock.h> 41 #include <net/arp.h> 42 #include <net/ip_fib.h> 43 #include <net/nexthop.h> 44 #include <net/rtnetlink.h> 45 #include <net/xfrm.h> 46 #include <net/l3mdev.h> 47 #include <net/lwtunnel.h> 48 #include <trace/events/fib.h> 49 50 #ifndef CONFIG_IP_MULTIPLE_TABLES 51 52 static int __net_init fib4_rules_init(struct net *net) 53 { 54 struct fib_table *local_table, *main_table; 55 56 main_table = fib_trie_table(RT_TABLE_MAIN, NULL); 57 if (!main_table) 58 return -ENOMEM; 59 60 local_table = fib_trie_table(RT_TABLE_LOCAL, main_table); 61 if (!local_table) 62 goto fail; 63 64 hlist_add_head_rcu(&local_table->tb_hlist, 65 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]); 66 hlist_add_head_rcu(&main_table->tb_hlist, 67 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]); 68 return 0; 69 70 fail: 71 fib_free_table(main_table); 72 return -ENOMEM; 73 } 74 #else 75 76 struct fib_table *fib_new_table(struct net *net, u32 id) 77 { 78 struct fib_table *tb, *alias = NULL; 79 unsigned int h; 80 81 if (id == 0) 82 id = RT_TABLE_MAIN; 83 tb = fib_get_table(net, id); 84 if (tb) 85 return tb; 86 87 if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules) 88 alias = fib_new_table(net, RT_TABLE_MAIN); 89 90 tb = fib_trie_table(id, alias); 91 if (!tb) 92 return NULL; 93 94 switch (id) { 95 case RT_TABLE_MAIN: 96 rcu_assign_pointer(net->ipv4.fib_main, tb); 97 break; 98 case RT_TABLE_DEFAULT: 99 rcu_assign_pointer(net->ipv4.fib_default, tb); 100 break; 101 default: 102 break; 103 } 104 105 h = id & (FIB_TABLE_HASHSZ - 1); 106 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]); 107 return tb; 108 } 109 EXPORT_SYMBOL_GPL(fib_new_table); 110 111 /* caller must hold either rtnl or rcu read lock */ 112 struct fib_table *fib_get_table(struct net *net, u32 id) 113 { 114 struct fib_table *tb; 115 struct hlist_head *head; 116 unsigned int h; 117 118 if (id == 0) 119 id = RT_TABLE_MAIN; 120 h = id & (FIB_TABLE_HASHSZ - 1); 121 122 head = &net->ipv4.fib_table_hash[h]; 123 hlist_for_each_entry_rcu(tb, head, tb_hlist, 124 lockdep_rtnl_is_held()) { 125 if (tb->tb_id == id) 126 return tb; 127 } 128 return NULL; 129 } 130 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 131 132 static void fib_replace_table(struct net *net, struct fib_table *old, 133 struct fib_table *new) 134 { 135 #ifdef CONFIG_IP_MULTIPLE_TABLES 136 switch (new->tb_id) { 137 case RT_TABLE_MAIN: 138 rcu_assign_pointer(net->ipv4.fib_main, new); 139 break; 140 case RT_TABLE_DEFAULT: 141 rcu_assign_pointer(net->ipv4.fib_default, new); 142 break; 143 default: 144 break; 145 } 146 147 #endif 148 /* replace the old table in the hlist */ 149 hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist); 150 } 151 152 int fib_unmerge(struct net *net) 153 { 154 struct fib_table *old, *new, *main_table; 155 156 /* attempt to fetch local table if it has been allocated */ 157 old = fib_get_table(net, RT_TABLE_LOCAL); 158 if (!old) 159 return 0; 160 161 new = fib_trie_unmerge(old); 162 if (!new) 163 return -ENOMEM; 164 165 /* table is already unmerged */ 166 if (new == old) 167 return 0; 168 169 /* replace merged table with clean table */ 170 fib_replace_table(net, old, new); 171 fib_free_table(old); 172 173 /* attempt to fetch main table if it has been allocated */ 174 main_table = fib_get_table(net, RT_TABLE_MAIN); 175 if (!main_table) 176 return 0; 177 178 /* flush local entries from main table */ 179 fib_table_flush_external(main_table); 180 181 return 0; 182 } 183 184 void fib_flush(struct net *net) 185 { 186 int flushed = 0; 187 unsigned int h; 188 189 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 190 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 191 struct hlist_node *tmp; 192 struct fib_table *tb; 193 194 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) 195 flushed += fib_table_flush(net, tb, false); 196 } 197 198 if (flushed) 199 rt_cache_flush(net); 200 } 201 202 /* 203 * Find address type as if only "dev" was present in the system. If 204 * on_dev is NULL then all interfaces are taken into consideration. 205 */ 206 static inline unsigned int __inet_dev_addr_type(struct net *net, 207 const struct net_device *dev, 208 __be32 addr, u32 tb_id) 209 { 210 struct flowi4 fl4 = { .daddr = addr }; 211 struct fib_result res; 212 unsigned int ret = RTN_BROADCAST; 213 struct fib_table *table; 214 215 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr)) 216 return RTN_BROADCAST; 217 if (ipv4_is_multicast(addr)) 218 return RTN_MULTICAST; 219 220 rcu_read_lock(); 221 222 table = fib_get_table(net, tb_id); 223 if (table) { 224 ret = RTN_UNICAST; 225 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) { 226 struct fib_nh_common *nhc = fib_info_nhc(res.fi, 0); 227 228 if (!dev || dev == nhc->nhc_dev) 229 ret = res.type; 230 } 231 } 232 233 rcu_read_unlock(); 234 return ret; 235 } 236 237 unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id) 238 { 239 return __inet_dev_addr_type(net, NULL, addr, tb_id); 240 } 241 EXPORT_SYMBOL(inet_addr_type_table); 242 243 unsigned int inet_addr_type(struct net *net, __be32 addr) 244 { 245 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL); 246 } 247 EXPORT_SYMBOL(inet_addr_type); 248 249 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, 250 __be32 addr) 251 { 252 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL; 253 254 return __inet_dev_addr_type(net, dev, addr, rt_table); 255 } 256 EXPORT_SYMBOL(inet_dev_addr_type); 257 258 /* inet_addr_type with dev == NULL but using the table from a dev 259 * if one is associated 260 */ 261 unsigned int inet_addr_type_dev_table(struct net *net, 262 const struct net_device *dev, 263 __be32 addr) 264 { 265 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL; 266 267 return __inet_dev_addr_type(net, NULL, addr, rt_table); 268 } 269 EXPORT_SYMBOL(inet_addr_type_dev_table); 270 271 __be32 fib_compute_spec_dst(struct sk_buff *skb) 272 { 273 struct net_device *dev = skb->dev; 274 struct in_device *in_dev; 275 struct fib_result res; 276 struct rtable *rt; 277 struct net *net; 278 int scope; 279 280 rt = skb_rtable(skb); 281 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) == 282 RTCF_LOCAL) 283 return ip_hdr(skb)->daddr; 284 285 in_dev = __in_dev_get_rcu(dev); 286 287 net = dev_net(dev); 288 289 scope = RT_SCOPE_UNIVERSE; 290 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) { 291 bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev); 292 struct flowi4 fl4 = { 293 .flowi4_iif = LOOPBACK_IFINDEX, 294 .flowi4_l3mdev = l3mdev_master_ifindex_rcu(dev), 295 .daddr = ip_hdr(skb)->saddr, 296 .flowi4_tos = inet_dscp_to_dsfield(ip4h_dscp(ip_hdr(skb))), 297 .flowi4_scope = scope, 298 .flowi4_mark = vmark ? skb->mark : 0, 299 }; 300 if (!fib_lookup(net, &fl4, &res, 0)) 301 return fib_result_prefsrc(net, &res); 302 } else { 303 scope = RT_SCOPE_LINK; 304 } 305 306 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope); 307 } 308 309 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev) 310 { 311 bool dev_match = false; 312 #ifdef CONFIG_IP_ROUTE_MULTIPATH 313 if (unlikely(fi->nh)) { 314 dev_match = nexthop_uses_dev(fi->nh, dev); 315 } else { 316 int ret; 317 318 for (ret = 0; ret < fib_info_num_path(fi); ret++) { 319 const struct fib_nh_common *nhc = fib_info_nhc(fi, ret); 320 321 if (nhc_l3mdev_matches_dev(nhc, dev)) { 322 dev_match = true; 323 break; 324 } 325 } 326 } 327 #else 328 if (fib_info_nhc(fi, 0)->nhc_dev == dev) 329 dev_match = true; 330 #endif 331 332 return dev_match; 333 } 334 EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev); 335 336 /* Given (packet source, input interface) and optional (dst, oif, tos): 337 * - (main) check, that source is valid i.e. not broadcast or our local 338 * address. 339 * - figure out what "logical" interface this packet arrived 340 * and calculate "specific destination" address. 341 * - check, that packet arrived from expected physical interface. 342 * called with rcu_read_lock() 343 */ 344 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 345 dscp_t dscp, int oif, struct net_device *dev, 346 int rpf, struct in_device *idev, u32 *itag) 347 { 348 struct net *net = dev_net(dev); 349 enum skb_drop_reason reason; 350 struct flow_keys flkeys; 351 int ret, no_addr; 352 struct fib_result res; 353 struct flowi4 fl4; 354 bool dev_match; 355 356 fl4.flowi4_oif = 0; 357 fl4.flowi4_l3mdev = l3mdev_master_ifindex_rcu(dev); 358 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX; 359 fl4.daddr = src; 360 fl4.saddr = dst; 361 fl4.flowi4_tos = inet_dscp_to_dsfield(dscp); 362 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 363 fl4.flowi4_tun_key.tun_id = 0; 364 fl4.flowi4_flags = 0; 365 fl4.flowi4_uid = sock_net_uid(net, NULL); 366 fl4.flowi4_multipath_hash = 0; 367 368 no_addr = idev->ifa_list == NULL; 369 370 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0; 371 if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) { 372 fl4.flowi4_proto = 0; 373 fl4.fl4_sport = 0; 374 fl4.fl4_dport = 0; 375 } else { 376 swap(fl4.fl4_sport, fl4.fl4_dport); 377 } 378 379 if (fib_lookup(net, &fl4, &res, 0)) 380 goto last_resort; 381 if (res.type != RTN_UNICAST) { 382 if (res.type != RTN_LOCAL) { 383 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 384 goto e_inval; 385 } else if (!IN_DEV_ACCEPT_LOCAL(idev)) { 386 reason = SKB_DROP_REASON_IP_LOCAL_SOURCE; 387 goto e_inval; 388 } 389 } 390 fib_combine_itag(itag, &res); 391 392 dev_match = fib_info_nh_uses_dev(res.fi, dev); 393 /* This is not common, loopback packets retain skb_dst so normally they 394 * would not even hit this slow path. 395 */ 396 dev_match = dev_match || (res.type == RTN_LOCAL && 397 dev == net->loopback_dev); 398 if (dev_match) { 399 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; 400 return ret; 401 } 402 if (no_addr) 403 goto last_resort; 404 if (rpf == 1) 405 goto e_rpf; 406 fl4.flowi4_oif = dev->ifindex; 407 408 ret = 0; 409 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) { 410 if (res.type == RTN_UNICAST) 411 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; 412 } 413 return ret; 414 415 last_resort: 416 if (rpf) 417 goto e_rpf; 418 *itag = 0; 419 return 0; 420 421 e_inval: 422 return -reason; 423 e_rpf: 424 return -SKB_DROP_REASON_IP_RPFILTER; 425 } 426 427 /* Ignore rp_filter for packets protected by IPsec. */ 428 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 429 dscp_t dscp, int oif, struct net_device *dev, 430 struct in_device *idev, u32 *itag) 431 { 432 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev); 433 struct net *net = dev_net(dev); 434 435 if (!r && !fib_num_tclassid_users(net) && 436 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) { 437 if (IN_DEV_ACCEPT_LOCAL(idev)) 438 goto ok; 439 /* with custom local routes in place, checking local addresses 440 * only will be too optimistic, with custom rules, checking 441 * local addresses only can be too strict, e.g. due to vrf 442 */ 443 if (net->ipv4.fib_has_custom_local_routes || 444 fib4_has_custom_rules(net)) 445 goto full_check; 446 /* Within the same container, it is regarded as a martian source, 447 * and the same host but different containers are not. 448 */ 449 if (inet_lookup_ifaddr_rcu(net, src)) 450 return -SKB_DROP_REASON_IP_LOCAL_SOURCE; 451 452 ok: 453 *itag = 0; 454 return 0; 455 } 456 457 full_check: 458 return __fib_validate_source(skb, src, dst, dscp, oif, dev, r, idev, 459 itag); 460 } 461 462 static inline __be32 sk_extract_addr(struct sockaddr *addr) 463 { 464 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 465 } 466 467 static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 468 { 469 struct nlattr *nla; 470 471 nla = (struct nlattr *) ((char *) mx + len); 472 nla->nla_type = type; 473 nla->nla_len = nla_attr_size(4); 474 *(u32 *) nla_data(nla) = value; 475 476 return len + nla_total_size(4); 477 } 478 479 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 480 struct fib_config *cfg) 481 { 482 __be32 addr; 483 int plen; 484 485 memset(cfg, 0, sizeof(*cfg)); 486 cfg->fc_nlinfo.nl_net = net; 487 488 if (rt->rt_dst.sa_family != AF_INET) 489 return -EAFNOSUPPORT; 490 491 /* 492 * Check mask for validity: 493 * a) it must be contiguous. 494 * b) destination must have all host bits clear. 495 * c) if application forgot to set correct family (AF_INET), 496 * reject request unless it is absolutely clear i.e. 497 * both family and mask are zero. 498 */ 499 plen = 32; 500 addr = sk_extract_addr(&rt->rt_dst); 501 if (!(rt->rt_flags & RTF_HOST)) { 502 __be32 mask = sk_extract_addr(&rt->rt_genmask); 503 504 if (rt->rt_genmask.sa_family != AF_INET) { 505 if (mask || rt->rt_genmask.sa_family) 506 return -EAFNOSUPPORT; 507 } 508 509 if (bad_mask(mask, addr)) 510 return -EINVAL; 511 512 plen = inet_mask_len(mask); 513 } 514 515 cfg->fc_dst_len = plen; 516 cfg->fc_dst = addr; 517 518 if (cmd != SIOCDELRT) { 519 cfg->fc_nlflags = NLM_F_CREATE; 520 cfg->fc_protocol = RTPROT_BOOT; 521 } 522 523 if (rt->rt_metric) 524 cfg->fc_priority = rt->rt_metric - 1; 525 526 if (rt->rt_flags & RTF_REJECT) { 527 cfg->fc_scope = RT_SCOPE_HOST; 528 cfg->fc_type = RTN_UNREACHABLE; 529 return 0; 530 } 531 532 cfg->fc_scope = RT_SCOPE_NOWHERE; 533 cfg->fc_type = RTN_UNICAST; 534 535 if (rt->rt_dev) { 536 char *colon; 537 struct net_device *dev; 538 char devname[IFNAMSIZ]; 539 540 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 541 return -EFAULT; 542 543 devname[IFNAMSIZ-1] = 0; 544 colon = strchr(devname, ':'); 545 if (colon) 546 *colon = 0; 547 dev = __dev_get_by_name(net, devname); 548 if (!dev) 549 return -ENODEV; 550 cfg->fc_oif = dev->ifindex; 551 cfg->fc_table = l3mdev_fib_table(dev); 552 if (colon) { 553 const struct in_ifaddr *ifa; 554 struct in_device *in_dev; 555 556 in_dev = __in_dev_get_rtnl_net(dev); 557 if (!in_dev) 558 return -ENODEV; 559 560 *colon = ':'; 561 562 in_dev_for_each_ifa_rtnl_net(net, ifa, in_dev) { 563 if (strcmp(ifa->ifa_label, devname) == 0) 564 break; 565 } 566 567 if (!ifa) 568 return -ENODEV; 569 cfg->fc_prefsrc = ifa->ifa_local; 570 } 571 } 572 573 addr = sk_extract_addr(&rt->rt_gateway); 574 if (rt->rt_gateway.sa_family == AF_INET && addr) { 575 unsigned int addr_type; 576 577 cfg->fc_gw4 = addr; 578 cfg->fc_gw_family = AF_INET; 579 addr_type = inet_addr_type_table(net, addr, cfg->fc_table); 580 if (rt->rt_flags & RTF_GATEWAY && 581 addr_type == RTN_UNICAST) 582 cfg->fc_scope = RT_SCOPE_UNIVERSE; 583 } 584 585 if (!cfg->fc_table) 586 cfg->fc_table = RT_TABLE_MAIN; 587 588 if (cmd == SIOCDELRT) 589 return 0; 590 591 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family) 592 return -EINVAL; 593 594 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 595 cfg->fc_scope = RT_SCOPE_LINK; 596 597 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 598 struct nlattr *mx; 599 int len = 0; 600 601 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL); 602 if (!mx) 603 return -ENOMEM; 604 605 if (rt->rt_flags & RTF_MTU) 606 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 607 608 if (rt->rt_flags & RTF_WINDOW) 609 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 610 611 if (rt->rt_flags & RTF_IRTT) 612 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 613 614 cfg->fc_mx = mx; 615 cfg->fc_mx_len = len; 616 } 617 618 return 0; 619 } 620 621 /* 622 * Handle IP routing ioctl calls. 623 * These are used to manipulate the routing tables 624 */ 625 int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt) 626 { 627 struct fib_config cfg; 628 int err; 629 630 switch (cmd) { 631 case SIOCADDRT: /* Add a route */ 632 case SIOCDELRT: /* Delete a route */ 633 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 634 return -EPERM; 635 636 rtnl_net_lock(net); 637 err = rtentry_to_fib_config(net, cmd, rt, &cfg); 638 if (err == 0) { 639 struct fib_table *tb; 640 641 if (cmd == SIOCDELRT) { 642 tb = fib_get_table(net, cfg.fc_table); 643 if (tb) 644 err = fib_table_delete(net, tb, &cfg, 645 NULL); 646 else 647 err = -ESRCH; 648 } else { 649 tb = fib_new_table(net, cfg.fc_table); 650 if (tb) 651 err = fib_table_insert(net, tb, 652 &cfg, NULL); 653 else 654 err = -ENOBUFS; 655 } 656 657 /* allocated by rtentry_to_fib_config() */ 658 kfree(cfg.fc_mx); 659 } 660 rtnl_net_unlock(net); 661 return err; 662 } 663 return -EINVAL; 664 } 665 666 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 667 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 }, 668 [RTA_DST] = { .type = NLA_U32 }, 669 [RTA_SRC] = { .type = NLA_U32 }, 670 [RTA_IIF] = { .type = NLA_U32 }, 671 [RTA_OIF] = { .type = NLA_U32 }, 672 [RTA_GATEWAY] = { .type = NLA_U32 }, 673 [RTA_PRIORITY] = { .type = NLA_U32 }, 674 [RTA_PREFSRC] = { .type = NLA_U32 }, 675 [RTA_METRICS] = { .type = NLA_NESTED }, 676 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 677 [RTA_FLOW] = { .type = NLA_U32 }, 678 [RTA_ENCAP_TYPE] = { .type = NLA_U16 }, 679 [RTA_ENCAP] = { .type = NLA_NESTED }, 680 [RTA_UID] = { .type = NLA_U32 }, 681 [RTA_MARK] = { .type = NLA_U32 }, 682 [RTA_TABLE] = { .type = NLA_U32 }, 683 [RTA_IP_PROTO] = { .type = NLA_U8 }, 684 [RTA_SPORT] = { .type = NLA_U16 }, 685 [RTA_DPORT] = { .type = NLA_U16 }, 686 [RTA_NH_ID] = { .type = NLA_U32 }, 687 }; 688 689 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, 690 struct netlink_ext_ack *extack) 691 { 692 struct rtvia *via; 693 int alen; 694 695 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) { 696 NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA"); 697 return -EINVAL; 698 } 699 700 via = nla_data(nla); 701 alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr); 702 703 switch (via->rtvia_family) { 704 case AF_INET: 705 if (alen != sizeof(__be32)) { 706 NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA"); 707 return -EINVAL; 708 } 709 cfg->fc_gw_family = AF_INET; 710 cfg->fc_gw4 = *((__be32 *)via->rtvia_addr); 711 break; 712 case AF_INET6: 713 #if IS_ENABLED(CONFIG_IPV6) 714 if (alen != sizeof(struct in6_addr)) { 715 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA"); 716 return -EINVAL; 717 } 718 cfg->fc_gw_family = AF_INET6; 719 cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr); 720 #else 721 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel"); 722 return -EINVAL; 723 #endif 724 break; 725 default: 726 NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA"); 727 return -EINVAL; 728 } 729 730 return 0; 731 } 732 733 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 734 struct nlmsghdr *nlh, struct fib_config *cfg, 735 struct netlink_ext_ack *extack) 736 { 737 bool has_gw = false, has_via = false; 738 struct nlattr *attr; 739 int err, remaining; 740 struct rtmsg *rtm; 741 742 err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX, 743 rtm_ipv4_policy, extack); 744 if (err < 0) 745 goto errout; 746 747 memset(cfg, 0, sizeof(*cfg)); 748 749 rtm = nlmsg_data(nlh); 750 751 if (!inet_validate_dscp(rtm->rtm_tos)) { 752 NL_SET_ERR_MSG(extack, 753 "Invalid dsfield (tos): ECN bits must be 0"); 754 err = -EINVAL; 755 goto errout; 756 } 757 cfg->fc_dscp = inet_dsfield_to_dscp(rtm->rtm_tos); 758 759 cfg->fc_dst_len = rtm->rtm_dst_len; 760 cfg->fc_table = rtm->rtm_table; 761 cfg->fc_protocol = rtm->rtm_protocol; 762 cfg->fc_scope = rtm->rtm_scope; 763 cfg->fc_type = rtm->rtm_type; 764 cfg->fc_flags = rtm->rtm_flags; 765 cfg->fc_nlflags = nlh->nlmsg_flags; 766 767 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid; 768 cfg->fc_nlinfo.nlh = nlh; 769 cfg->fc_nlinfo.nl_net = net; 770 771 if (cfg->fc_type > RTN_MAX) { 772 NL_SET_ERR_MSG(extack, "Invalid route type"); 773 err = -EINVAL; 774 goto errout; 775 } 776 777 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 778 switch (nla_type(attr)) { 779 case RTA_DST: 780 cfg->fc_dst = nla_get_be32(attr); 781 break; 782 case RTA_OIF: 783 cfg->fc_oif = nla_get_u32(attr); 784 break; 785 case RTA_GATEWAY: 786 has_gw = true; 787 cfg->fc_gw4 = nla_get_be32(attr); 788 if (cfg->fc_gw4) 789 cfg->fc_gw_family = AF_INET; 790 break; 791 case RTA_VIA: 792 has_via = true; 793 err = fib_gw_from_via(cfg, attr, extack); 794 if (err) 795 goto errout; 796 break; 797 case RTA_PRIORITY: 798 cfg->fc_priority = nla_get_u32(attr); 799 break; 800 case RTA_PREFSRC: 801 cfg->fc_prefsrc = nla_get_be32(attr); 802 break; 803 case RTA_METRICS: 804 cfg->fc_mx = nla_data(attr); 805 cfg->fc_mx_len = nla_len(attr); 806 break; 807 case RTA_MULTIPATH: 808 err = lwtunnel_valid_encap_type_attr(nla_data(attr), 809 nla_len(attr), 810 extack, false); 811 if (err < 0) 812 goto errout; 813 cfg->fc_mp = nla_data(attr); 814 cfg->fc_mp_len = nla_len(attr); 815 break; 816 case RTA_FLOW: 817 cfg->fc_flow = nla_get_u32(attr); 818 break; 819 case RTA_TABLE: 820 cfg->fc_table = nla_get_u32(attr); 821 break; 822 case RTA_ENCAP: 823 cfg->fc_encap = attr; 824 break; 825 case RTA_ENCAP_TYPE: 826 cfg->fc_encap_type = nla_get_u16(attr); 827 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, 828 extack, false); 829 if (err < 0) 830 goto errout; 831 break; 832 case RTA_NH_ID: 833 cfg->fc_nh_id = nla_get_u32(attr); 834 break; 835 } 836 } 837 838 if (cfg->fc_dst_len > 32) { 839 NL_SET_ERR_MSG(extack, "Invalid prefix length"); 840 err = -EINVAL; 841 goto errout; 842 } 843 844 if (cfg->fc_dst_len < 32 && (ntohl(cfg->fc_dst) << cfg->fc_dst_len)) { 845 NL_SET_ERR_MSG(extack, "Invalid prefix for given prefix length"); 846 err = -EINVAL; 847 goto errout; 848 } 849 850 if (cfg->fc_nh_id) { 851 if (cfg->fc_oif || cfg->fc_gw_family || 852 cfg->fc_encap || cfg->fc_mp) { 853 NL_SET_ERR_MSG(extack, 854 "Nexthop specification and nexthop id are mutually exclusive"); 855 err = -EINVAL; 856 goto errout; 857 } 858 } 859 860 if (has_gw && has_via) { 861 NL_SET_ERR_MSG(extack, 862 "Nexthop configuration can not contain both GATEWAY and VIA"); 863 err = -EINVAL; 864 goto errout; 865 } 866 867 if (!cfg->fc_table) 868 cfg->fc_table = RT_TABLE_MAIN; 869 870 return 0; 871 errout: 872 return err; 873 } 874 875 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, 876 struct netlink_ext_ack *extack) 877 { 878 struct net *net = sock_net(skb->sk); 879 struct fib_config cfg; 880 struct fib_table *tb; 881 int err; 882 883 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 884 if (err < 0) 885 goto errout; 886 887 rtnl_net_lock(net); 888 889 if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) { 890 NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); 891 err = -EINVAL; 892 goto unlock; 893 } 894 895 tb = fib_get_table(net, cfg.fc_table); 896 if (!tb) { 897 NL_SET_ERR_MSG(extack, "FIB table does not exist"); 898 err = -ESRCH; 899 goto unlock; 900 } 901 902 err = fib_table_delete(net, tb, &cfg, extack); 903 unlock: 904 rtnl_net_unlock(net); 905 errout: 906 return err; 907 } 908 909 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, 910 struct netlink_ext_ack *extack) 911 { 912 struct net *net = sock_net(skb->sk); 913 struct fib_config cfg; 914 struct fib_table *tb; 915 int err; 916 917 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 918 if (err < 0) 919 goto errout; 920 921 rtnl_net_lock(net); 922 923 tb = fib_new_table(net, cfg.fc_table); 924 if (!tb) { 925 err = -ENOBUFS; 926 goto unlock; 927 } 928 929 err = fib_table_insert(net, tb, &cfg, extack); 930 if (!err && cfg.fc_type == RTN_LOCAL) 931 net->ipv4.fib_has_custom_local_routes = true; 932 933 unlock: 934 rtnl_net_unlock(net); 935 errout: 936 return err; 937 } 938 939 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 940 struct fib_dump_filter *filter, 941 struct netlink_callback *cb) 942 { 943 struct netlink_ext_ack *extack = cb->extack; 944 struct nlattr *tb[RTA_MAX + 1]; 945 struct rtmsg *rtm; 946 int err, i; 947 948 if (filter->rtnl_held) 949 ASSERT_RTNL(); 950 951 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 952 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request"); 953 return -EINVAL; 954 } 955 956 rtm = nlmsg_data(nlh); 957 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos || 958 rtm->rtm_scope) { 959 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request"); 960 return -EINVAL; 961 } 962 963 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) { 964 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request"); 965 return -EINVAL; 966 } 967 if (rtm->rtm_flags & RTM_F_CLONED) 968 filter->dump_routes = false; 969 else 970 filter->dump_exceptions = false; 971 972 filter->flags = rtm->rtm_flags; 973 filter->protocol = rtm->rtm_protocol; 974 filter->rt_type = rtm->rtm_type; 975 filter->table_id = rtm->rtm_table; 976 977 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 978 rtm_ipv4_policy, extack); 979 if (err < 0) 980 return err; 981 982 for (i = 0; i <= RTA_MAX; ++i) { 983 int ifindex; 984 985 if (!tb[i]) 986 continue; 987 988 switch (i) { 989 case RTA_TABLE: 990 filter->table_id = nla_get_u32(tb[i]); 991 break; 992 case RTA_OIF: 993 ifindex = nla_get_u32(tb[i]); 994 if (filter->rtnl_held) 995 filter->dev = __dev_get_by_index(net, ifindex); 996 else 997 filter->dev = dev_get_by_index_rcu(net, ifindex); 998 if (!filter->dev) 999 return -ENODEV; 1000 break; 1001 default: 1002 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request"); 1003 return -EINVAL; 1004 } 1005 } 1006 1007 if (filter->flags || filter->protocol || filter->rt_type || 1008 filter->table_id || filter->dev) { 1009 filter->filter_set = 1; 1010 cb->answer_flags = NLM_F_DUMP_FILTERED; 1011 } 1012 1013 return 0; 1014 } 1015 EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req); 1016 1017 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 1018 { 1019 struct fib_dump_filter filter = { 1020 .dump_routes = true, 1021 .dump_exceptions = true, 1022 .rtnl_held = false, 1023 }; 1024 const struct nlmsghdr *nlh = cb->nlh; 1025 struct net *net = sock_net(skb->sk); 1026 unsigned int h, s_h; 1027 unsigned int e = 0, s_e; 1028 struct fib_table *tb; 1029 struct hlist_head *head; 1030 int dumped = 0, err = 0; 1031 1032 rcu_read_lock(); 1033 if (cb->strict_check) { 1034 err = ip_valid_fib_dump_req(net, nlh, &filter, cb); 1035 if (err < 0) 1036 goto unlock; 1037 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 1038 struct rtmsg *rtm = nlmsg_data(nlh); 1039 1040 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED); 1041 } 1042 1043 /* ipv4 does not use prefix flag */ 1044 if (filter.flags & RTM_F_PREFIX) 1045 goto unlock; 1046 1047 if (filter.table_id) { 1048 tb = fib_get_table(net, filter.table_id); 1049 if (!tb) { 1050 if (rtnl_msg_family(cb->nlh) != PF_INET) 1051 goto unlock; 1052 1053 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist"); 1054 err = -ENOENT; 1055 goto unlock; 1056 } 1057 err = fib_table_dump(tb, skb, cb, &filter); 1058 goto unlock; 1059 } 1060 1061 s_h = cb->args[0]; 1062 s_e = cb->args[1]; 1063 1064 err = 0; 1065 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 1066 e = 0; 1067 head = &net->ipv4.fib_table_hash[h]; 1068 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 1069 if (e < s_e) 1070 goto next; 1071 if (dumped) 1072 memset(&cb->args[2], 0, sizeof(cb->args) - 1073 2 * sizeof(cb->args[0])); 1074 err = fib_table_dump(tb, skb, cb, &filter); 1075 if (err < 0) 1076 goto out; 1077 dumped = 1; 1078 next: 1079 e++; 1080 } 1081 } 1082 out: 1083 1084 cb->args[1] = e; 1085 cb->args[0] = h; 1086 1087 unlock: 1088 rcu_read_unlock(); 1089 return err; 1090 } 1091 1092 /* Prepare and feed intra-kernel routing request. 1093 * Really, it should be netlink message, but :-( netlink 1094 * can be not configured, so that we feed it directly 1095 * to fib engine. It is legal, because all events occur 1096 * only when netlink is already locked. 1097 */ 1098 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, 1099 struct in_ifaddr *ifa, u32 rt_priority) 1100 { 1101 struct net *net = dev_net(ifa->ifa_dev->dev); 1102 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev); 1103 struct fib_table *tb; 1104 struct fib_config cfg = { 1105 .fc_protocol = RTPROT_KERNEL, 1106 .fc_type = type, 1107 .fc_dst = dst, 1108 .fc_dst_len = dst_len, 1109 .fc_priority = rt_priority, 1110 .fc_prefsrc = ifa->ifa_local, 1111 .fc_oif = ifa->ifa_dev->dev->ifindex, 1112 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 1113 .fc_nlinfo = { 1114 .nl_net = net, 1115 }, 1116 }; 1117 1118 if (!tb_id) 1119 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL; 1120 1121 tb = fib_new_table(net, tb_id); 1122 if (!tb) 1123 return; 1124 1125 cfg.fc_table = tb->tb_id; 1126 1127 if (type != RTN_LOCAL) 1128 cfg.fc_scope = RT_SCOPE_LINK; 1129 else 1130 cfg.fc_scope = RT_SCOPE_HOST; 1131 1132 if (cmd == RTM_NEWROUTE) 1133 fib_table_insert(net, tb, &cfg, NULL); 1134 else 1135 fib_table_delete(net, tb, &cfg, NULL); 1136 } 1137 1138 void fib_add_ifaddr(struct in_ifaddr *ifa) 1139 { 1140 struct in_device *in_dev = ifa->ifa_dev; 1141 struct net_device *dev = in_dev->dev; 1142 struct in_ifaddr *prim = ifa; 1143 __be32 mask = ifa->ifa_mask; 1144 __be32 addr = ifa->ifa_local; 1145 __be32 prefix = ifa->ifa_address & mask; 1146 1147 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1148 prim = inet_ifa_byprefix(in_dev, prefix, mask); 1149 if (!prim) { 1150 pr_warn("%s: bug: prim == NULL\n", __func__); 1151 return; 1152 } 1153 } 1154 1155 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0); 1156 1157 if (!(dev->flags & IFF_UP)) 1158 return; 1159 1160 /* Add broadcast address, if it is explicitly assigned. */ 1161 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) { 1162 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1163 prim, 0); 1164 arp_invalidate(dev, ifa->ifa_broadcast, false); 1165 } 1166 1167 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 1168 (prefix != addr || ifa->ifa_prefixlen < 32)) { 1169 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1170 fib_magic(RTM_NEWROUTE, 1171 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1172 prefix, ifa->ifa_prefixlen, prim, 1173 ifa->ifa_rt_priority); 1174 1175 /* Add the network broadcast address, when it makes sense */ 1176 if (ifa->ifa_prefixlen < 31) { 1177 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 1178 32, prim, 0); 1179 arp_invalidate(dev, prefix | ~mask, false); 1180 } 1181 } 1182 } 1183 1184 void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric) 1185 { 1186 __be32 prefix = ifa->ifa_address & ifa->ifa_mask; 1187 struct in_device *in_dev = ifa->ifa_dev; 1188 struct net_device *dev = in_dev->dev; 1189 1190 if (!(dev->flags & IFF_UP) || 1191 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) || 1192 ipv4_is_zeronet(prefix) || 1193 (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32)) 1194 return; 1195 1196 /* add the new */ 1197 fib_magic(RTM_NEWROUTE, 1198 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1199 prefix, ifa->ifa_prefixlen, ifa, new_metric); 1200 1201 /* delete the old */ 1202 fib_magic(RTM_DELROUTE, 1203 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1204 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority); 1205 } 1206 1207 /* Delete primary or secondary address. 1208 * Optionally, on secondary address promotion consider the addresses 1209 * from subnet iprim as deleted, even if they are in device list. 1210 * In this case the secondary ifa can be in device list. 1211 */ 1212 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 1213 { 1214 struct in_device *in_dev = ifa->ifa_dev; 1215 struct net_device *dev = in_dev->dev; 1216 struct in_ifaddr *ifa1; 1217 struct in_ifaddr *prim = ifa, *prim1 = NULL; 1218 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 1219 __be32 any = ifa->ifa_address & ifa->ifa_mask; 1220 #define LOCAL_OK 1 1221 #define BRD_OK 2 1222 #define BRD0_OK 4 1223 #define BRD1_OK 8 1224 unsigned int ok = 0; 1225 int subnet = 0; /* Primary network */ 1226 int gone = 1; /* Address is missing */ 1227 int same_prefsrc = 0; /* Another primary with same IP */ 1228 1229 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1230 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 1231 if (!prim) { 1232 /* if the device has been deleted, we don't perform 1233 * address promotion 1234 */ 1235 if (!in_dev->dead) 1236 pr_warn("%s: bug: prim == NULL\n", __func__); 1237 return; 1238 } 1239 if (iprim && iprim != prim) { 1240 pr_warn("%s: bug: iprim != prim\n", __func__); 1241 return; 1242 } 1243 } else if (!ipv4_is_zeronet(any) && 1244 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 1245 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1246 fib_magic(RTM_DELROUTE, 1247 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1248 any, ifa->ifa_prefixlen, prim, 0); 1249 subnet = 1; 1250 } 1251 1252 if (in_dev->dead) 1253 goto no_promotions; 1254 1255 /* Deletion is more complicated than add. 1256 * We should take care of not to delete too much :-) 1257 * 1258 * Scan address list to be sure that addresses are really gone. 1259 */ 1260 rcu_read_lock(); 1261 in_dev_for_each_ifa_rcu(ifa1, in_dev) { 1262 if (ifa1 == ifa) { 1263 /* promotion, keep the IP */ 1264 gone = 0; 1265 continue; 1266 } 1267 /* Ignore IFAs from our subnet */ 1268 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 1269 inet_ifa_match(ifa1->ifa_address, iprim)) 1270 continue; 1271 1272 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 1273 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 1274 /* Another address from our subnet? */ 1275 if (ifa1->ifa_mask == prim->ifa_mask && 1276 inet_ifa_match(ifa1->ifa_address, prim)) 1277 prim1 = prim; 1278 else { 1279 /* We reached the secondaries, so 1280 * same_prefsrc should be determined. 1281 */ 1282 if (!same_prefsrc) 1283 continue; 1284 /* Search new prim1 if ifa1 is not 1285 * using the current prim1 1286 */ 1287 if (!prim1 || 1288 ifa1->ifa_mask != prim1->ifa_mask || 1289 !inet_ifa_match(ifa1->ifa_address, prim1)) 1290 prim1 = inet_ifa_byprefix(in_dev, 1291 ifa1->ifa_address, 1292 ifa1->ifa_mask); 1293 if (!prim1) 1294 continue; 1295 if (prim1->ifa_local != prim->ifa_local) 1296 continue; 1297 } 1298 } else { 1299 if (prim->ifa_local != ifa1->ifa_local) 1300 continue; 1301 prim1 = ifa1; 1302 if (prim != prim1) 1303 same_prefsrc = 1; 1304 } 1305 if (ifa->ifa_local == ifa1->ifa_local) 1306 ok |= LOCAL_OK; 1307 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 1308 ok |= BRD_OK; 1309 if (brd == ifa1->ifa_broadcast) 1310 ok |= BRD1_OK; 1311 if (any == ifa1->ifa_broadcast) 1312 ok |= BRD0_OK; 1313 /* primary has network specific broadcasts */ 1314 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 1315 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 1316 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 1317 1318 if (!ipv4_is_zeronet(any1)) { 1319 if (ifa->ifa_broadcast == brd1 || 1320 ifa->ifa_broadcast == any1) 1321 ok |= BRD_OK; 1322 if (brd == brd1 || brd == any1) 1323 ok |= BRD1_OK; 1324 if (any == brd1 || any == any1) 1325 ok |= BRD0_OK; 1326 } 1327 } 1328 } 1329 rcu_read_unlock(); 1330 1331 no_promotions: 1332 if (!(ok & BRD_OK)) 1333 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1334 prim, 0); 1335 if (subnet && ifa->ifa_prefixlen < 31) { 1336 if (!(ok & BRD1_OK)) 1337 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, 1338 prim, 0); 1339 if (!(ok & BRD0_OK)) 1340 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, 1341 prim, 0); 1342 } 1343 if (!(ok & LOCAL_OK)) { 1344 unsigned int addr_type; 1345 1346 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0); 1347 1348 /* Check, that this local address finally disappeared. */ 1349 addr_type = inet_addr_type_dev_table(dev_net(dev), dev, 1350 ifa->ifa_local); 1351 if (gone && addr_type != RTN_LOCAL) { 1352 /* And the last, but not the least thing. 1353 * We must flush stray FIB entries. 1354 * 1355 * First of all, we scan fib_info list searching 1356 * for stray nexthop entries, then ignite fib_flush. 1357 */ 1358 if (fib_sync_down_addr(dev, ifa->ifa_local)) 1359 fib_flush(dev_net(dev)); 1360 } 1361 } 1362 #undef LOCAL_OK 1363 #undef BRD_OK 1364 #undef BRD0_OK 1365 #undef BRD1_OK 1366 } 1367 1368 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn) 1369 { 1370 1371 struct fib_result res; 1372 struct flowi4 fl4 = { 1373 .flowi4_mark = frn->fl_mark, 1374 .daddr = frn->fl_addr, 1375 .flowi4_tos = frn->fl_tos & INET_DSCP_MASK, 1376 .flowi4_scope = frn->fl_scope, 1377 }; 1378 struct fib_table *tb; 1379 1380 rcu_read_lock(); 1381 1382 tb = fib_get_table(net, frn->tb_id_in); 1383 1384 frn->err = -ENOENT; 1385 if (tb) { 1386 local_bh_disable(); 1387 1388 frn->tb_id = tb->tb_id; 1389 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 1390 1391 if (!frn->err) { 1392 frn->prefixlen = res.prefixlen; 1393 frn->nh_sel = res.nh_sel; 1394 frn->type = res.type; 1395 frn->scope = res.scope; 1396 } 1397 local_bh_enable(); 1398 } 1399 1400 rcu_read_unlock(); 1401 } 1402 1403 static void nl_fib_input(struct sk_buff *skb) 1404 { 1405 struct net *net; 1406 struct fib_result_nl *frn; 1407 struct nlmsghdr *nlh; 1408 u32 portid; 1409 1410 net = sock_net(skb->sk); 1411 nlh = nlmsg_hdr(skb); 1412 if (skb->len < nlmsg_total_size(sizeof(*frn)) || 1413 skb->len < nlh->nlmsg_len || 1414 nlmsg_len(nlh) < sizeof(*frn)) 1415 return; 1416 1417 skb = netlink_skb_clone(skb, GFP_KERNEL); 1418 if (!skb) 1419 return; 1420 nlh = nlmsg_hdr(skb); 1421 1422 frn = nlmsg_data(nlh); 1423 nl_fib_lookup(net, frn); 1424 1425 portid = NETLINK_CB(skb).portid; /* netlink portid */ 1426 NETLINK_CB(skb).portid = 0; /* from kernel */ 1427 NETLINK_CB(skb).dst_group = 0; /* unicast */ 1428 nlmsg_unicast(net->ipv4.fibnl, skb, portid); 1429 } 1430 1431 static int __net_init nl_fib_lookup_init(struct net *net) 1432 { 1433 struct sock *sk; 1434 struct netlink_kernel_cfg cfg = { 1435 .input = nl_fib_input, 1436 }; 1437 1438 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg); 1439 if (!sk) 1440 return -EAFNOSUPPORT; 1441 net->ipv4.fibnl = sk; 1442 return 0; 1443 } 1444 1445 static void nl_fib_lookup_exit(struct net *net) 1446 { 1447 netlink_kernel_release(net->ipv4.fibnl); 1448 net->ipv4.fibnl = NULL; 1449 } 1450 1451 static void fib_disable_ip(struct net_device *dev, unsigned long event, 1452 bool force) 1453 { 1454 if (fib_sync_down_dev(dev, event, force)) 1455 fib_flush(dev_net(dev)); 1456 else 1457 rt_cache_flush(dev_net(dev)); 1458 arp_ifdown(dev); 1459 } 1460 1461 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 1462 { 1463 struct in_ifaddr *ifa = ptr; 1464 struct net_device *dev = ifa->ifa_dev->dev; 1465 struct net *net = dev_net(dev); 1466 1467 switch (event) { 1468 case NETDEV_UP: 1469 fib_add_ifaddr(ifa); 1470 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1471 fib_sync_up(dev, RTNH_F_DEAD); 1472 #endif 1473 atomic_inc(&net->ipv4.dev_addr_genid); 1474 rt_cache_flush(net); 1475 break; 1476 case NETDEV_DOWN: 1477 fib_del_ifaddr(ifa, NULL); 1478 atomic_inc(&net->ipv4.dev_addr_genid); 1479 if (!ifa->ifa_dev->ifa_list) { 1480 /* Last address was deleted from this interface. 1481 * Disable IP. 1482 */ 1483 fib_disable_ip(dev, event, true); 1484 } else { 1485 rt_cache_flush(net); 1486 } 1487 break; 1488 } 1489 return NOTIFY_DONE; 1490 } 1491 1492 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1493 { 1494 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1495 struct netdev_notifier_changeupper_info *upper_info = ptr; 1496 struct netdev_notifier_info_ext *info_ext = ptr; 1497 struct in_device *in_dev; 1498 struct net *net = dev_net(dev); 1499 struct in_ifaddr *ifa; 1500 unsigned int flags; 1501 1502 if (event == NETDEV_UNREGISTER) { 1503 fib_disable_ip(dev, event, true); 1504 rt_flush_dev(dev); 1505 return NOTIFY_DONE; 1506 } 1507 1508 in_dev = __in_dev_get_rtnl(dev); 1509 if (!in_dev) 1510 return NOTIFY_DONE; 1511 1512 switch (event) { 1513 case NETDEV_UP: 1514 in_dev_for_each_ifa_rtnl(ifa, in_dev) { 1515 fib_add_ifaddr(ifa); 1516 } 1517 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1518 fib_sync_up(dev, RTNH_F_DEAD); 1519 #endif 1520 atomic_inc(&net->ipv4.dev_addr_genid); 1521 rt_cache_flush(net); 1522 break; 1523 case NETDEV_DOWN: 1524 fib_disable_ip(dev, event, false); 1525 break; 1526 case NETDEV_CHANGE: 1527 flags = dev_get_flags(dev); 1528 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1529 fib_sync_up(dev, RTNH_F_LINKDOWN); 1530 else 1531 fib_sync_down_dev(dev, event, false); 1532 rt_cache_flush(net); 1533 break; 1534 case NETDEV_CHANGEMTU: 1535 fib_sync_mtu(dev, info_ext->ext.mtu); 1536 rt_cache_flush(net); 1537 break; 1538 case NETDEV_CHANGEUPPER: 1539 upper_info = ptr; 1540 /* flush all routes if dev is linked to or unlinked from 1541 * an L3 master device (e.g., VRF) 1542 */ 1543 if (upper_info->upper_dev && 1544 netif_is_l3_master(upper_info->upper_dev)) 1545 fib_disable_ip(dev, NETDEV_DOWN, true); 1546 break; 1547 } 1548 return NOTIFY_DONE; 1549 } 1550 1551 static struct notifier_block fib_inetaddr_notifier = { 1552 .notifier_call = fib_inetaddr_event, 1553 }; 1554 1555 static struct notifier_block fib_netdev_notifier = { 1556 .notifier_call = fib_netdev_event, 1557 }; 1558 1559 static int __net_init ip_fib_net_init(struct net *net) 1560 { 1561 int err; 1562 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1563 1564 err = fib4_notifier_init(net); 1565 if (err) 1566 return err; 1567 1568 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1569 /* Default to 3-tuple */ 1570 net->ipv4.sysctl_fib_multipath_hash_fields = 1571 FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK; 1572 #endif 1573 1574 /* Avoid false sharing : Use at least a full cache line */ 1575 size = max_t(size_t, size, L1_CACHE_BYTES); 1576 1577 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1578 if (!net->ipv4.fib_table_hash) { 1579 err = -ENOMEM; 1580 goto err_table_hash_alloc; 1581 } 1582 1583 err = fib4_rules_init(net); 1584 if (err < 0) 1585 goto err_rules_init; 1586 return 0; 1587 1588 err_rules_init: 1589 kfree(net->ipv4.fib_table_hash); 1590 err_table_hash_alloc: 1591 fib4_notifier_exit(net); 1592 return err; 1593 } 1594 1595 static void ip_fib_net_exit(struct net *net) 1596 { 1597 int i; 1598 1599 ASSERT_RTNL_NET(net); 1600 #ifdef CONFIG_IP_MULTIPLE_TABLES 1601 RCU_INIT_POINTER(net->ipv4.fib_main, NULL); 1602 RCU_INIT_POINTER(net->ipv4.fib_default, NULL); 1603 #endif 1604 /* Destroy the tables in reverse order to guarantee that the 1605 * local table, ID 255, is destroyed before the main table, ID 1606 * 254. This is necessary as the local table may contain 1607 * references to data contained in the main table. 1608 */ 1609 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) { 1610 struct hlist_head *head = &net->ipv4.fib_table_hash[i]; 1611 struct hlist_node *tmp; 1612 struct fib_table *tb; 1613 1614 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) { 1615 hlist_del(&tb->tb_hlist); 1616 fib_table_flush(net, tb, true); 1617 fib_free_table(tb); 1618 } 1619 } 1620 1621 #ifdef CONFIG_IP_MULTIPLE_TABLES 1622 fib4_rules_exit(net); 1623 #endif 1624 1625 kfree(net->ipv4.fib_table_hash); 1626 fib4_notifier_exit(net); 1627 } 1628 1629 static int __net_init fib_net_init(struct net *net) 1630 { 1631 int error; 1632 1633 #ifdef CONFIG_IP_ROUTE_CLASSID 1634 atomic_set(&net->ipv4.fib_num_tclassid_users, 0); 1635 #endif 1636 error = ip_fib_net_init(net); 1637 if (error < 0) 1638 goto out; 1639 1640 error = fib4_semantics_init(net); 1641 if (error) 1642 goto out_semantics; 1643 1644 error = nl_fib_lookup_init(net); 1645 if (error < 0) 1646 goto out_nlfl; 1647 1648 error = fib_proc_init(net); 1649 if (error < 0) 1650 goto out_proc; 1651 out: 1652 return error; 1653 1654 out_proc: 1655 nl_fib_lookup_exit(net); 1656 out_nlfl: 1657 fib4_semantics_exit(net); 1658 out_semantics: 1659 rtnl_net_lock(net); 1660 ip_fib_net_exit(net); 1661 rtnl_net_unlock(net); 1662 goto out; 1663 } 1664 1665 static void __net_exit fib_net_exit(struct net *net) 1666 { 1667 fib_proc_exit(net); 1668 nl_fib_lookup_exit(net); 1669 } 1670 1671 static void __net_exit fib_net_exit_batch(struct list_head *net_list) 1672 { 1673 struct net *net; 1674 1675 rtnl_lock(); 1676 list_for_each_entry(net, net_list, exit_list) { 1677 __rtnl_net_lock(net); 1678 ip_fib_net_exit(net); 1679 __rtnl_net_unlock(net); 1680 } 1681 rtnl_unlock(); 1682 1683 list_for_each_entry(net, net_list, exit_list) 1684 fib4_semantics_exit(net); 1685 } 1686 1687 static struct pernet_operations fib_net_ops = { 1688 .init = fib_net_init, 1689 .exit = fib_net_exit, 1690 .exit_batch = fib_net_exit_batch, 1691 }; 1692 1693 static const struct rtnl_msg_handler fib_rtnl_msg_handlers[] __initconst = { 1694 {.protocol = PF_INET, .msgtype = RTM_NEWROUTE, 1695 .doit = inet_rtm_newroute, .flags = RTNL_FLAG_DOIT_PERNET}, 1696 {.protocol = PF_INET, .msgtype = RTM_DELROUTE, 1697 .doit = inet_rtm_delroute, .flags = RTNL_FLAG_DOIT_PERNET}, 1698 {.protocol = PF_INET, .msgtype = RTM_GETROUTE, .dumpit = inet_dump_fib, 1699 .flags = RTNL_FLAG_DUMP_UNLOCKED | RTNL_FLAG_DUMP_SPLIT_NLM_DONE}, 1700 }; 1701 1702 void __init ip_fib_init(void) 1703 { 1704 fib_trie_init(); 1705 1706 register_pernet_subsys(&fib_net_ops); 1707 1708 register_netdevice_notifier(&fib_netdev_notifier); 1709 register_inetaddr_notifier(&fib_inetaddr_notifier); 1710 1711 rtnl_register_many(fib_rtnl_msg_handlers); 1712 } 1713