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(dev); 557 if (!in_dev) 558 return -ENODEV; 559 560 *colon = ':'; 561 562 rcu_read_lock(); 563 in_dev_for_each_ifa_rcu(ifa, in_dev) { 564 if (strcmp(ifa->ifa_label, devname) == 0) 565 break; 566 } 567 rcu_read_unlock(); 568 569 if (!ifa) 570 return -ENODEV; 571 cfg->fc_prefsrc = ifa->ifa_local; 572 } 573 } 574 575 addr = sk_extract_addr(&rt->rt_gateway); 576 if (rt->rt_gateway.sa_family == AF_INET && addr) { 577 unsigned int addr_type; 578 579 cfg->fc_gw4 = addr; 580 cfg->fc_gw_family = AF_INET; 581 addr_type = inet_addr_type_table(net, addr, cfg->fc_table); 582 if (rt->rt_flags & RTF_GATEWAY && 583 addr_type == RTN_UNICAST) 584 cfg->fc_scope = RT_SCOPE_UNIVERSE; 585 } 586 587 if (!cfg->fc_table) 588 cfg->fc_table = RT_TABLE_MAIN; 589 590 if (cmd == SIOCDELRT) 591 return 0; 592 593 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family) 594 return -EINVAL; 595 596 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 597 cfg->fc_scope = RT_SCOPE_LINK; 598 599 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 600 struct nlattr *mx; 601 int len = 0; 602 603 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL); 604 if (!mx) 605 return -ENOMEM; 606 607 if (rt->rt_flags & RTF_MTU) 608 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 609 610 if (rt->rt_flags & RTF_WINDOW) 611 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 612 613 if (rt->rt_flags & RTF_IRTT) 614 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 615 616 cfg->fc_mx = mx; 617 cfg->fc_mx_len = len; 618 } 619 620 return 0; 621 } 622 623 /* 624 * Handle IP routing ioctl calls. 625 * These are used to manipulate the routing tables 626 */ 627 int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt) 628 { 629 struct fib_config cfg; 630 int err; 631 632 switch (cmd) { 633 case SIOCADDRT: /* Add a route */ 634 case SIOCDELRT: /* Delete a route */ 635 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 636 return -EPERM; 637 638 rtnl_lock(); 639 err = rtentry_to_fib_config(net, cmd, rt, &cfg); 640 if (err == 0) { 641 struct fib_table *tb; 642 643 if (cmd == SIOCDELRT) { 644 tb = fib_get_table(net, cfg.fc_table); 645 if (tb) 646 err = fib_table_delete(net, tb, &cfg, 647 NULL); 648 else 649 err = -ESRCH; 650 } else { 651 tb = fib_new_table(net, cfg.fc_table); 652 if (tb) 653 err = fib_table_insert(net, tb, 654 &cfg, NULL); 655 else 656 err = -ENOBUFS; 657 } 658 659 /* allocated by rtentry_to_fib_config() */ 660 kfree(cfg.fc_mx); 661 } 662 rtnl_unlock(); 663 return err; 664 } 665 return -EINVAL; 666 } 667 668 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 669 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 }, 670 [RTA_DST] = { .type = NLA_U32 }, 671 [RTA_SRC] = { .type = NLA_U32 }, 672 [RTA_IIF] = { .type = NLA_U32 }, 673 [RTA_OIF] = { .type = NLA_U32 }, 674 [RTA_GATEWAY] = { .type = NLA_U32 }, 675 [RTA_PRIORITY] = { .type = NLA_U32 }, 676 [RTA_PREFSRC] = { .type = NLA_U32 }, 677 [RTA_METRICS] = { .type = NLA_NESTED }, 678 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 679 [RTA_FLOW] = { .type = NLA_U32 }, 680 [RTA_ENCAP_TYPE] = { .type = NLA_U16 }, 681 [RTA_ENCAP] = { .type = NLA_NESTED }, 682 [RTA_UID] = { .type = NLA_U32 }, 683 [RTA_MARK] = { .type = NLA_U32 }, 684 [RTA_TABLE] = { .type = NLA_U32 }, 685 [RTA_IP_PROTO] = { .type = NLA_U8 }, 686 [RTA_SPORT] = { .type = NLA_U16 }, 687 [RTA_DPORT] = { .type = NLA_U16 }, 688 [RTA_NH_ID] = { .type = NLA_U32 }, 689 }; 690 691 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, 692 struct netlink_ext_ack *extack) 693 { 694 struct rtvia *via; 695 int alen; 696 697 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) { 698 NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA"); 699 return -EINVAL; 700 } 701 702 via = nla_data(nla); 703 alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr); 704 705 switch (via->rtvia_family) { 706 case AF_INET: 707 if (alen != sizeof(__be32)) { 708 NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA"); 709 return -EINVAL; 710 } 711 cfg->fc_gw_family = AF_INET; 712 cfg->fc_gw4 = *((__be32 *)via->rtvia_addr); 713 break; 714 case AF_INET6: 715 #if IS_ENABLED(CONFIG_IPV6) 716 if (alen != sizeof(struct in6_addr)) { 717 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA"); 718 return -EINVAL; 719 } 720 cfg->fc_gw_family = AF_INET6; 721 cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr); 722 #else 723 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel"); 724 return -EINVAL; 725 #endif 726 break; 727 default: 728 NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA"); 729 return -EINVAL; 730 } 731 732 return 0; 733 } 734 735 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 736 struct nlmsghdr *nlh, struct fib_config *cfg, 737 struct netlink_ext_ack *extack) 738 { 739 bool has_gw = false, has_via = false; 740 struct nlattr *attr; 741 int err, remaining; 742 struct rtmsg *rtm; 743 744 err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX, 745 rtm_ipv4_policy, extack); 746 if (err < 0) 747 goto errout; 748 749 memset(cfg, 0, sizeof(*cfg)); 750 751 rtm = nlmsg_data(nlh); 752 753 if (!inet_validate_dscp(rtm->rtm_tos)) { 754 NL_SET_ERR_MSG(extack, 755 "Invalid dsfield (tos): ECN bits must be 0"); 756 err = -EINVAL; 757 goto errout; 758 } 759 cfg->fc_dscp = inet_dsfield_to_dscp(rtm->rtm_tos); 760 761 cfg->fc_dst_len = rtm->rtm_dst_len; 762 cfg->fc_table = rtm->rtm_table; 763 cfg->fc_protocol = rtm->rtm_protocol; 764 cfg->fc_scope = rtm->rtm_scope; 765 cfg->fc_type = rtm->rtm_type; 766 cfg->fc_flags = rtm->rtm_flags; 767 cfg->fc_nlflags = nlh->nlmsg_flags; 768 769 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid; 770 cfg->fc_nlinfo.nlh = nlh; 771 cfg->fc_nlinfo.nl_net = net; 772 773 if (cfg->fc_type > RTN_MAX) { 774 NL_SET_ERR_MSG(extack, "Invalid route type"); 775 err = -EINVAL; 776 goto errout; 777 } 778 779 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 780 switch (nla_type(attr)) { 781 case RTA_DST: 782 cfg->fc_dst = nla_get_be32(attr); 783 break; 784 case RTA_OIF: 785 cfg->fc_oif = nla_get_u32(attr); 786 break; 787 case RTA_GATEWAY: 788 has_gw = true; 789 cfg->fc_gw4 = nla_get_be32(attr); 790 if (cfg->fc_gw4) 791 cfg->fc_gw_family = AF_INET; 792 break; 793 case RTA_VIA: 794 has_via = true; 795 err = fib_gw_from_via(cfg, attr, extack); 796 if (err) 797 goto errout; 798 break; 799 case RTA_PRIORITY: 800 cfg->fc_priority = nla_get_u32(attr); 801 break; 802 case RTA_PREFSRC: 803 cfg->fc_prefsrc = nla_get_be32(attr); 804 break; 805 case RTA_METRICS: 806 cfg->fc_mx = nla_data(attr); 807 cfg->fc_mx_len = nla_len(attr); 808 break; 809 case RTA_MULTIPATH: 810 err = lwtunnel_valid_encap_type_attr(nla_data(attr), 811 nla_len(attr), 812 extack); 813 if (err < 0) 814 goto errout; 815 cfg->fc_mp = nla_data(attr); 816 cfg->fc_mp_len = nla_len(attr); 817 break; 818 case RTA_FLOW: 819 cfg->fc_flow = nla_get_u32(attr); 820 break; 821 case RTA_TABLE: 822 cfg->fc_table = nla_get_u32(attr); 823 break; 824 case RTA_ENCAP: 825 cfg->fc_encap = attr; 826 break; 827 case RTA_ENCAP_TYPE: 828 cfg->fc_encap_type = nla_get_u16(attr); 829 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, 830 extack); 831 if (err < 0) 832 goto errout; 833 break; 834 case RTA_NH_ID: 835 cfg->fc_nh_id = nla_get_u32(attr); 836 break; 837 } 838 } 839 840 if (cfg->fc_nh_id) { 841 if (cfg->fc_oif || cfg->fc_gw_family || 842 cfg->fc_encap || cfg->fc_mp) { 843 NL_SET_ERR_MSG(extack, 844 "Nexthop specification and nexthop id are mutually exclusive"); 845 return -EINVAL; 846 } 847 } 848 849 if (has_gw && has_via) { 850 NL_SET_ERR_MSG(extack, 851 "Nexthop configuration can not contain both GATEWAY and VIA"); 852 return -EINVAL; 853 } 854 855 if (!cfg->fc_table) 856 cfg->fc_table = RT_TABLE_MAIN; 857 858 return 0; 859 errout: 860 return err; 861 } 862 863 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, 864 struct netlink_ext_ack *extack) 865 { 866 struct net *net = sock_net(skb->sk); 867 struct fib_config cfg; 868 struct fib_table *tb; 869 int err; 870 871 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 872 if (err < 0) 873 goto errout; 874 875 if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) { 876 NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); 877 err = -EINVAL; 878 goto errout; 879 } 880 881 tb = fib_get_table(net, cfg.fc_table); 882 if (!tb) { 883 NL_SET_ERR_MSG(extack, "FIB table does not exist"); 884 err = -ESRCH; 885 goto errout; 886 } 887 888 err = fib_table_delete(net, tb, &cfg, extack); 889 errout: 890 return err; 891 } 892 893 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, 894 struct netlink_ext_ack *extack) 895 { 896 struct net *net = sock_net(skb->sk); 897 struct fib_config cfg; 898 struct fib_table *tb; 899 int err; 900 901 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 902 if (err < 0) 903 goto errout; 904 905 tb = fib_new_table(net, cfg.fc_table); 906 if (!tb) { 907 err = -ENOBUFS; 908 goto errout; 909 } 910 911 err = fib_table_insert(net, tb, &cfg, extack); 912 if (!err && cfg.fc_type == RTN_LOCAL) 913 net->ipv4.fib_has_custom_local_routes = true; 914 errout: 915 return err; 916 } 917 918 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 919 struct fib_dump_filter *filter, 920 struct netlink_callback *cb) 921 { 922 struct netlink_ext_ack *extack = cb->extack; 923 struct nlattr *tb[RTA_MAX + 1]; 924 struct rtmsg *rtm; 925 int err, i; 926 927 if (filter->rtnl_held) 928 ASSERT_RTNL(); 929 930 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 931 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request"); 932 return -EINVAL; 933 } 934 935 rtm = nlmsg_data(nlh); 936 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos || 937 rtm->rtm_scope) { 938 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request"); 939 return -EINVAL; 940 } 941 942 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) { 943 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request"); 944 return -EINVAL; 945 } 946 if (rtm->rtm_flags & RTM_F_CLONED) 947 filter->dump_routes = false; 948 else 949 filter->dump_exceptions = false; 950 951 filter->flags = rtm->rtm_flags; 952 filter->protocol = rtm->rtm_protocol; 953 filter->rt_type = rtm->rtm_type; 954 filter->table_id = rtm->rtm_table; 955 956 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 957 rtm_ipv4_policy, extack); 958 if (err < 0) 959 return err; 960 961 for (i = 0; i <= RTA_MAX; ++i) { 962 int ifindex; 963 964 if (!tb[i]) 965 continue; 966 967 switch (i) { 968 case RTA_TABLE: 969 filter->table_id = nla_get_u32(tb[i]); 970 break; 971 case RTA_OIF: 972 ifindex = nla_get_u32(tb[i]); 973 if (filter->rtnl_held) 974 filter->dev = __dev_get_by_index(net, ifindex); 975 else 976 filter->dev = dev_get_by_index_rcu(net, ifindex); 977 if (!filter->dev) 978 return -ENODEV; 979 break; 980 default: 981 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request"); 982 return -EINVAL; 983 } 984 } 985 986 if (filter->flags || filter->protocol || filter->rt_type || 987 filter->table_id || filter->dev) { 988 filter->filter_set = 1; 989 cb->answer_flags = NLM_F_DUMP_FILTERED; 990 } 991 992 return 0; 993 } 994 EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req); 995 996 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 997 { 998 struct fib_dump_filter filter = { 999 .dump_routes = true, 1000 .dump_exceptions = true, 1001 .rtnl_held = false, 1002 }; 1003 const struct nlmsghdr *nlh = cb->nlh; 1004 struct net *net = sock_net(skb->sk); 1005 unsigned int h, s_h; 1006 unsigned int e = 0, s_e; 1007 struct fib_table *tb; 1008 struct hlist_head *head; 1009 int dumped = 0, err = 0; 1010 1011 rcu_read_lock(); 1012 if (cb->strict_check) { 1013 err = ip_valid_fib_dump_req(net, nlh, &filter, cb); 1014 if (err < 0) 1015 goto unlock; 1016 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 1017 struct rtmsg *rtm = nlmsg_data(nlh); 1018 1019 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED); 1020 } 1021 1022 /* ipv4 does not use prefix flag */ 1023 if (filter.flags & RTM_F_PREFIX) 1024 goto unlock; 1025 1026 if (filter.table_id) { 1027 tb = fib_get_table(net, filter.table_id); 1028 if (!tb) { 1029 if (rtnl_msg_family(cb->nlh) != PF_INET) 1030 goto unlock; 1031 1032 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist"); 1033 err = -ENOENT; 1034 goto unlock; 1035 } 1036 err = fib_table_dump(tb, skb, cb, &filter); 1037 goto unlock; 1038 } 1039 1040 s_h = cb->args[0]; 1041 s_e = cb->args[1]; 1042 1043 err = 0; 1044 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 1045 e = 0; 1046 head = &net->ipv4.fib_table_hash[h]; 1047 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 1048 if (e < s_e) 1049 goto next; 1050 if (dumped) 1051 memset(&cb->args[2], 0, sizeof(cb->args) - 1052 2 * sizeof(cb->args[0])); 1053 err = fib_table_dump(tb, skb, cb, &filter); 1054 if (err < 0) 1055 goto out; 1056 dumped = 1; 1057 next: 1058 e++; 1059 } 1060 } 1061 out: 1062 1063 cb->args[1] = e; 1064 cb->args[0] = h; 1065 1066 unlock: 1067 rcu_read_unlock(); 1068 return err; 1069 } 1070 1071 /* Prepare and feed intra-kernel routing request. 1072 * Really, it should be netlink message, but :-( netlink 1073 * can be not configured, so that we feed it directly 1074 * to fib engine. It is legal, because all events occur 1075 * only when netlink is already locked. 1076 */ 1077 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, 1078 struct in_ifaddr *ifa, u32 rt_priority) 1079 { 1080 struct net *net = dev_net(ifa->ifa_dev->dev); 1081 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev); 1082 struct fib_table *tb; 1083 struct fib_config cfg = { 1084 .fc_protocol = RTPROT_KERNEL, 1085 .fc_type = type, 1086 .fc_dst = dst, 1087 .fc_dst_len = dst_len, 1088 .fc_priority = rt_priority, 1089 .fc_prefsrc = ifa->ifa_local, 1090 .fc_oif = ifa->ifa_dev->dev->ifindex, 1091 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 1092 .fc_nlinfo = { 1093 .nl_net = net, 1094 }, 1095 }; 1096 1097 if (!tb_id) 1098 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL; 1099 1100 tb = fib_new_table(net, tb_id); 1101 if (!tb) 1102 return; 1103 1104 cfg.fc_table = tb->tb_id; 1105 1106 if (type != RTN_LOCAL) 1107 cfg.fc_scope = RT_SCOPE_LINK; 1108 else 1109 cfg.fc_scope = RT_SCOPE_HOST; 1110 1111 if (cmd == RTM_NEWROUTE) 1112 fib_table_insert(net, tb, &cfg, NULL); 1113 else 1114 fib_table_delete(net, tb, &cfg, NULL); 1115 } 1116 1117 void fib_add_ifaddr(struct in_ifaddr *ifa) 1118 { 1119 struct in_device *in_dev = ifa->ifa_dev; 1120 struct net_device *dev = in_dev->dev; 1121 struct in_ifaddr *prim = ifa; 1122 __be32 mask = ifa->ifa_mask; 1123 __be32 addr = ifa->ifa_local; 1124 __be32 prefix = ifa->ifa_address & mask; 1125 1126 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1127 prim = inet_ifa_byprefix(in_dev, prefix, mask); 1128 if (!prim) { 1129 pr_warn("%s: bug: prim == NULL\n", __func__); 1130 return; 1131 } 1132 } 1133 1134 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0); 1135 1136 if (!(dev->flags & IFF_UP)) 1137 return; 1138 1139 /* Add broadcast address, if it is explicitly assigned. */ 1140 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) { 1141 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1142 prim, 0); 1143 arp_invalidate(dev, ifa->ifa_broadcast, false); 1144 } 1145 1146 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 1147 (prefix != addr || ifa->ifa_prefixlen < 32)) { 1148 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1149 fib_magic(RTM_NEWROUTE, 1150 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1151 prefix, ifa->ifa_prefixlen, prim, 1152 ifa->ifa_rt_priority); 1153 1154 /* Add the network broadcast address, when it makes sense */ 1155 if (ifa->ifa_prefixlen < 31) { 1156 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 1157 32, prim, 0); 1158 arp_invalidate(dev, prefix | ~mask, false); 1159 } 1160 } 1161 } 1162 1163 void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric) 1164 { 1165 __be32 prefix = ifa->ifa_address & ifa->ifa_mask; 1166 struct in_device *in_dev = ifa->ifa_dev; 1167 struct net_device *dev = in_dev->dev; 1168 1169 if (!(dev->flags & IFF_UP) || 1170 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) || 1171 ipv4_is_zeronet(prefix) || 1172 (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32)) 1173 return; 1174 1175 /* add the new */ 1176 fib_magic(RTM_NEWROUTE, 1177 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1178 prefix, ifa->ifa_prefixlen, ifa, new_metric); 1179 1180 /* delete the old */ 1181 fib_magic(RTM_DELROUTE, 1182 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1183 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority); 1184 } 1185 1186 /* Delete primary or secondary address. 1187 * Optionally, on secondary address promotion consider the addresses 1188 * from subnet iprim as deleted, even if they are in device list. 1189 * In this case the secondary ifa can be in device list. 1190 */ 1191 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 1192 { 1193 struct in_device *in_dev = ifa->ifa_dev; 1194 struct net_device *dev = in_dev->dev; 1195 struct in_ifaddr *ifa1; 1196 struct in_ifaddr *prim = ifa, *prim1 = NULL; 1197 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 1198 __be32 any = ifa->ifa_address & ifa->ifa_mask; 1199 #define LOCAL_OK 1 1200 #define BRD_OK 2 1201 #define BRD0_OK 4 1202 #define BRD1_OK 8 1203 unsigned int ok = 0; 1204 int subnet = 0; /* Primary network */ 1205 int gone = 1; /* Address is missing */ 1206 int same_prefsrc = 0; /* Another primary with same IP */ 1207 1208 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1209 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 1210 if (!prim) { 1211 /* if the device has been deleted, we don't perform 1212 * address promotion 1213 */ 1214 if (!in_dev->dead) 1215 pr_warn("%s: bug: prim == NULL\n", __func__); 1216 return; 1217 } 1218 if (iprim && iprim != prim) { 1219 pr_warn("%s: bug: iprim != prim\n", __func__); 1220 return; 1221 } 1222 } else if (!ipv4_is_zeronet(any) && 1223 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 1224 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1225 fib_magic(RTM_DELROUTE, 1226 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1227 any, ifa->ifa_prefixlen, prim, 0); 1228 subnet = 1; 1229 } 1230 1231 if (in_dev->dead) 1232 goto no_promotions; 1233 1234 /* Deletion is more complicated than add. 1235 * We should take care of not to delete too much :-) 1236 * 1237 * Scan address list to be sure that addresses are really gone. 1238 */ 1239 rcu_read_lock(); 1240 in_dev_for_each_ifa_rcu(ifa1, in_dev) { 1241 if (ifa1 == ifa) { 1242 /* promotion, keep the IP */ 1243 gone = 0; 1244 continue; 1245 } 1246 /* Ignore IFAs from our subnet */ 1247 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 1248 inet_ifa_match(ifa1->ifa_address, iprim)) 1249 continue; 1250 1251 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 1252 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 1253 /* Another address from our subnet? */ 1254 if (ifa1->ifa_mask == prim->ifa_mask && 1255 inet_ifa_match(ifa1->ifa_address, prim)) 1256 prim1 = prim; 1257 else { 1258 /* We reached the secondaries, so 1259 * same_prefsrc should be determined. 1260 */ 1261 if (!same_prefsrc) 1262 continue; 1263 /* Search new prim1 if ifa1 is not 1264 * using the current prim1 1265 */ 1266 if (!prim1 || 1267 ifa1->ifa_mask != prim1->ifa_mask || 1268 !inet_ifa_match(ifa1->ifa_address, prim1)) 1269 prim1 = inet_ifa_byprefix(in_dev, 1270 ifa1->ifa_address, 1271 ifa1->ifa_mask); 1272 if (!prim1) 1273 continue; 1274 if (prim1->ifa_local != prim->ifa_local) 1275 continue; 1276 } 1277 } else { 1278 if (prim->ifa_local != ifa1->ifa_local) 1279 continue; 1280 prim1 = ifa1; 1281 if (prim != prim1) 1282 same_prefsrc = 1; 1283 } 1284 if (ifa->ifa_local == ifa1->ifa_local) 1285 ok |= LOCAL_OK; 1286 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 1287 ok |= BRD_OK; 1288 if (brd == ifa1->ifa_broadcast) 1289 ok |= BRD1_OK; 1290 if (any == ifa1->ifa_broadcast) 1291 ok |= BRD0_OK; 1292 /* primary has network specific broadcasts */ 1293 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 1294 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 1295 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 1296 1297 if (!ipv4_is_zeronet(any1)) { 1298 if (ifa->ifa_broadcast == brd1 || 1299 ifa->ifa_broadcast == any1) 1300 ok |= BRD_OK; 1301 if (brd == brd1 || brd == any1) 1302 ok |= BRD1_OK; 1303 if (any == brd1 || any == any1) 1304 ok |= BRD0_OK; 1305 } 1306 } 1307 } 1308 rcu_read_unlock(); 1309 1310 no_promotions: 1311 if (!(ok & BRD_OK)) 1312 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1313 prim, 0); 1314 if (subnet && ifa->ifa_prefixlen < 31) { 1315 if (!(ok & BRD1_OK)) 1316 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, 1317 prim, 0); 1318 if (!(ok & BRD0_OK)) 1319 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, 1320 prim, 0); 1321 } 1322 if (!(ok & LOCAL_OK)) { 1323 unsigned int addr_type; 1324 1325 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0); 1326 1327 /* Check, that this local address finally disappeared. */ 1328 addr_type = inet_addr_type_dev_table(dev_net(dev), dev, 1329 ifa->ifa_local); 1330 if (gone && addr_type != RTN_LOCAL) { 1331 /* And the last, but not the least thing. 1332 * We must flush stray FIB entries. 1333 * 1334 * First of all, we scan fib_info list searching 1335 * for stray nexthop entries, then ignite fib_flush. 1336 */ 1337 if (fib_sync_down_addr(dev, ifa->ifa_local)) 1338 fib_flush(dev_net(dev)); 1339 } 1340 } 1341 #undef LOCAL_OK 1342 #undef BRD_OK 1343 #undef BRD0_OK 1344 #undef BRD1_OK 1345 } 1346 1347 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn) 1348 { 1349 1350 struct fib_result res; 1351 struct flowi4 fl4 = { 1352 .flowi4_mark = frn->fl_mark, 1353 .daddr = frn->fl_addr, 1354 .flowi4_tos = frn->fl_tos & INET_DSCP_MASK, 1355 .flowi4_scope = frn->fl_scope, 1356 }; 1357 struct fib_table *tb; 1358 1359 rcu_read_lock(); 1360 1361 tb = fib_get_table(net, frn->tb_id_in); 1362 1363 frn->err = -ENOENT; 1364 if (tb) { 1365 local_bh_disable(); 1366 1367 frn->tb_id = tb->tb_id; 1368 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 1369 1370 if (!frn->err) { 1371 frn->prefixlen = res.prefixlen; 1372 frn->nh_sel = res.nh_sel; 1373 frn->type = res.type; 1374 frn->scope = res.scope; 1375 } 1376 local_bh_enable(); 1377 } 1378 1379 rcu_read_unlock(); 1380 } 1381 1382 static void nl_fib_input(struct sk_buff *skb) 1383 { 1384 struct net *net; 1385 struct fib_result_nl *frn; 1386 struct nlmsghdr *nlh; 1387 u32 portid; 1388 1389 net = sock_net(skb->sk); 1390 nlh = nlmsg_hdr(skb); 1391 if (skb->len < nlmsg_total_size(sizeof(*frn)) || 1392 skb->len < nlh->nlmsg_len || 1393 nlmsg_len(nlh) < sizeof(*frn)) 1394 return; 1395 1396 skb = netlink_skb_clone(skb, GFP_KERNEL); 1397 if (!skb) 1398 return; 1399 nlh = nlmsg_hdr(skb); 1400 1401 frn = nlmsg_data(nlh); 1402 nl_fib_lookup(net, frn); 1403 1404 portid = NETLINK_CB(skb).portid; /* netlink portid */ 1405 NETLINK_CB(skb).portid = 0; /* from kernel */ 1406 NETLINK_CB(skb).dst_group = 0; /* unicast */ 1407 nlmsg_unicast(net->ipv4.fibnl, skb, portid); 1408 } 1409 1410 static int __net_init nl_fib_lookup_init(struct net *net) 1411 { 1412 struct sock *sk; 1413 struct netlink_kernel_cfg cfg = { 1414 .input = nl_fib_input, 1415 }; 1416 1417 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg); 1418 if (!sk) 1419 return -EAFNOSUPPORT; 1420 net->ipv4.fibnl = sk; 1421 return 0; 1422 } 1423 1424 static void nl_fib_lookup_exit(struct net *net) 1425 { 1426 netlink_kernel_release(net->ipv4.fibnl); 1427 net->ipv4.fibnl = NULL; 1428 } 1429 1430 static void fib_disable_ip(struct net_device *dev, unsigned long event, 1431 bool force) 1432 { 1433 if (fib_sync_down_dev(dev, event, force)) 1434 fib_flush(dev_net(dev)); 1435 else 1436 rt_cache_flush(dev_net(dev)); 1437 arp_ifdown(dev); 1438 } 1439 1440 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 1441 { 1442 struct in_ifaddr *ifa = ptr; 1443 struct net_device *dev = ifa->ifa_dev->dev; 1444 struct net *net = dev_net(dev); 1445 1446 switch (event) { 1447 case NETDEV_UP: 1448 fib_add_ifaddr(ifa); 1449 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1450 fib_sync_up(dev, RTNH_F_DEAD); 1451 #endif 1452 atomic_inc(&net->ipv4.dev_addr_genid); 1453 rt_cache_flush(dev_net(dev)); 1454 break; 1455 case NETDEV_DOWN: 1456 fib_del_ifaddr(ifa, NULL); 1457 atomic_inc(&net->ipv4.dev_addr_genid); 1458 if (!ifa->ifa_dev->ifa_list) { 1459 /* Last address was deleted from this interface. 1460 * Disable IP. 1461 */ 1462 fib_disable_ip(dev, event, true); 1463 } else { 1464 rt_cache_flush(dev_net(dev)); 1465 } 1466 break; 1467 } 1468 return NOTIFY_DONE; 1469 } 1470 1471 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1472 { 1473 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1474 struct netdev_notifier_changeupper_info *upper_info = ptr; 1475 struct netdev_notifier_info_ext *info_ext = ptr; 1476 struct in_device *in_dev; 1477 struct net *net = dev_net(dev); 1478 struct in_ifaddr *ifa; 1479 unsigned int flags; 1480 1481 if (event == NETDEV_UNREGISTER) { 1482 fib_disable_ip(dev, event, true); 1483 rt_flush_dev(dev); 1484 return NOTIFY_DONE; 1485 } 1486 1487 in_dev = __in_dev_get_rtnl(dev); 1488 if (!in_dev) 1489 return NOTIFY_DONE; 1490 1491 switch (event) { 1492 case NETDEV_UP: 1493 in_dev_for_each_ifa_rtnl(ifa, in_dev) { 1494 fib_add_ifaddr(ifa); 1495 } 1496 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1497 fib_sync_up(dev, RTNH_F_DEAD); 1498 #endif 1499 atomic_inc(&net->ipv4.dev_addr_genid); 1500 rt_cache_flush(net); 1501 break; 1502 case NETDEV_DOWN: 1503 fib_disable_ip(dev, event, false); 1504 break; 1505 case NETDEV_CHANGE: 1506 flags = dev_get_flags(dev); 1507 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1508 fib_sync_up(dev, RTNH_F_LINKDOWN); 1509 else 1510 fib_sync_down_dev(dev, event, false); 1511 rt_cache_flush(net); 1512 break; 1513 case NETDEV_CHANGEMTU: 1514 fib_sync_mtu(dev, info_ext->ext.mtu); 1515 rt_cache_flush(net); 1516 break; 1517 case NETDEV_CHANGEUPPER: 1518 upper_info = ptr; 1519 /* flush all routes if dev is linked to or unlinked from 1520 * an L3 master device (e.g., VRF) 1521 */ 1522 if (upper_info->upper_dev && 1523 netif_is_l3_master(upper_info->upper_dev)) 1524 fib_disable_ip(dev, NETDEV_DOWN, true); 1525 break; 1526 } 1527 return NOTIFY_DONE; 1528 } 1529 1530 static struct notifier_block fib_inetaddr_notifier = { 1531 .notifier_call = fib_inetaddr_event, 1532 }; 1533 1534 static struct notifier_block fib_netdev_notifier = { 1535 .notifier_call = fib_netdev_event, 1536 }; 1537 1538 static int __net_init ip_fib_net_init(struct net *net) 1539 { 1540 int err; 1541 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1542 1543 err = fib4_notifier_init(net); 1544 if (err) 1545 return err; 1546 1547 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1548 /* Default to 3-tuple */ 1549 net->ipv4.sysctl_fib_multipath_hash_fields = 1550 FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK; 1551 #endif 1552 1553 /* Avoid false sharing : Use at least a full cache line */ 1554 size = max_t(size_t, size, L1_CACHE_BYTES); 1555 1556 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1557 if (!net->ipv4.fib_table_hash) { 1558 err = -ENOMEM; 1559 goto err_table_hash_alloc; 1560 } 1561 1562 err = fib4_rules_init(net); 1563 if (err < 0) 1564 goto err_rules_init; 1565 return 0; 1566 1567 err_rules_init: 1568 kfree(net->ipv4.fib_table_hash); 1569 err_table_hash_alloc: 1570 fib4_notifier_exit(net); 1571 return err; 1572 } 1573 1574 static void ip_fib_net_exit(struct net *net) 1575 { 1576 int i; 1577 1578 ASSERT_RTNL(); 1579 #ifdef CONFIG_IP_MULTIPLE_TABLES 1580 RCU_INIT_POINTER(net->ipv4.fib_main, NULL); 1581 RCU_INIT_POINTER(net->ipv4.fib_default, NULL); 1582 #endif 1583 /* Destroy the tables in reverse order to guarantee that the 1584 * local table, ID 255, is destroyed before the main table, ID 1585 * 254. This is necessary as the local table may contain 1586 * references to data contained in the main table. 1587 */ 1588 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) { 1589 struct hlist_head *head = &net->ipv4.fib_table_hash[i]; 1590 struct hlist_node *tmp; 1591 struct fib_table *tb; 1592 1593 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) { 1594 hlist_del(&tb->tb_hlist); 1595 fib_table_flush(net, tb, true); 1596 fib_free_table(tb); 1597 } 1598 } 1599 1600 #ifdef CONFIG_IP_MULTIPLE_TABLES 1601 fib4_rules_exit(net); 1602 #endif 1603 1604 kfree(net->ipv4.fib_table_hash); 1605 fib4_notifier_exit(net); 1606 } 1607 1608 static int __net_init fib_net_init(struct net *net) 1609 { 1610 int error; 1611 1612 #ifdef CONFIG_IP_ROUTE_CLASSID 1613 atomic_set(&net->ipv4.fib_num_tclassid_users, 0); 1614 #endif 1615 error = ip_fib_net_init(net); 1616 if (error < 0) 1617 goto out; 1618 error = nl_fib_lookup_init(net); 1619 if (error < 0) 1620 goto out_nlfl; 1621 error = fib_proc_init(net); 1622 if (error < 0) 1623 goto out_proc; 1624 out: 1625 return error; 1626 1627 out_proc: 1628 nl_fib_lookup_exit(net); 1629 out_nlfl: 1630 rtnl_lock(); 1631 ip_fib_net_exit(net); 1632 rtnl_unlock(); 1633 goto out; 1634 } 1635 1636 static void __net_exit fib_net_exit(struct net *net) 1637 { 1638 fib_proc_exit(net); 1639 nl_fib_lookup_exit(net); 1640 } 1641 1642 static void __net_exit fib_net_exit_batch(struct list_head *net_list) 1643 { 1644 struct net *net; 1645 1646 rtnl_lock(); 1647 list_for_each_entry(net, net_list, exit_list) 1648 ip_fib_net_exit(net); 1649 1650 rtnl_unlock(); 1651 } 1652 1653 static struct pernet_operations fib_net_ops = { 1654 .init = fib_net_init, 1655 .exit = fib_net_exit, 1656 .exit_batch = fib_net_exit_batch, 1657 }; 1658 1659 static const struct rtnl_msg_handler fib_rtnl_msg_handlers[] __initconst = { 1660 {.protocol = PF_INET, .msgtype = RTM_NEWROUTE, 1661 .doit = inet_rtm_newroute}, 1662 {.protocol = PF_INET, .msgtype = RTM_DELROUTE, 1663 .doit = inet_rtm_delroute}, 1664 {.protocol = PF_INET, .msgtype = RTM_GETROUTE, .dumpit = inet_dump_fib, 1665 .flags = RTNL_FLAG_DUMP_UNLOCKED | RTNL_FLAG_DUMP_SPLIT_NLM_DONE}, 1666 }; 1667 1668 void __init ip_fib_init(void) 1669 { 1670 fib_trie_init(); 1671 1672 register_pernet_subsys(&fib_net_ops); 1673 1674 register_netdevice_notifier(&fib_netdev_notifier); 1675 register_inetaddr_notifier(&fib_inetaddr_notifier); 1676 1677 rtnl_register_many(fib_rtnl_msg_handlers); 1678 } 1679