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 = ip_hdr(skb)->tos & IPTOS_RT_MASK, 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 u8 tos, int oif, struct net_device *dev, 346 int rpf, struct in_device *idev, u32 *itag) 347 { 348 struct net *net = dev_net(dev); 349 struct flow_keys flkeys; 350 int ret, no_addr; 351 struct fib_result res; 352 struct flowi4 fl4; 353 bool dev_match; 354 355 fl4.flowi4_oif = 0; 356 fl4.flowi4_l3mdev = l3mdev_master_ifindex_rcu(dev); 357 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX; 358 fl4.daddr = src; 359 fl4.saddr = dst; 360 fl4.flowi4_tos = tos; 361 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 362 fl4.flowi4_tun_key.tun_id = 0; 363 fl4.flowi4_flags = 0; 364 fl4.flowi4_uid = sock_net_uid(net, NULL); 365 fl4.flowi4_multipath_hash = 0; 366 367 no_addr = idev->ifa_list == NULL; 368 369 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0; 370 if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) { 371 fl4.flowi4_proto = 0; 372 fl4.fl4_sport = 0; 373 fl4.fl4_dport = 0; 374 } else { 375 swap(fl4.fl4_sport, fl4.fl4_dport); 376 } 377 378 if (fib_lookup(net, &fl4, &res, 0)) 379 goto last_resort; 380 if (res.type != RTN_UNICAST && 381 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev))) 382 goto e_inval; 383 fib_combine_itag(itag, &res); 384 385 dev_match = fib_info_nh_uses_dev(res.fi, dev); 386 /* This is not common, loopback packets retain skb_dst so normally they 387 * would not even hit this slow path. 388 */ 389 dev_match = dev_match || (res.type == RTN_LOCAL && 390 dev == net->loopback_dev); 391 if (dev_match) { 392 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; 393 return ret; 394 } 395 if (no_addr) 396 goto last_resort; 397 if (rpf == 1) 398 goto e_rpf; 399 fl4.flowi4_oif = dev->ifindex; 400 401 ret = 0; 402 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) { 403 if (res.type == RTN_UNICAST) 404 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; 405 } 406 return ret; 407 408 last_resort: 409 if (rpf) 410 goto e_rpf; 411 *itag = 0; 412 return 0; 413 414 e_inval: 415 return -EINVAL; 416 e_rpf: 417 return -EXDEV; 418 } 419 420 /* Ignore rp_filter for packets protected by IPsec. */ 421 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 422 u8 tos, int oif, struct net_device *dev, 423 struct in_device *idev, u32 *itag) 424 { 425 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev); 426 struct net *net = dev_net(dev); 427 428 if (!r && !fib_num_tclassid_users(net) && 429 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) { 430 if (IN_DEV_ACCEPT_LOCAL(idev)) 431 goto ok; 432 /* with custom local routes in place, checking local addresses 433 * only will be too optimistic, with custom rules, checking 434 * local addresses only can be too strict, e.g. due to vrf 435 */ 436 if (net->ipv4.fib_has_custom_local_routes || 437 fib4_has_custom_rules(net)) 438 goto full_check; 439 /* Within the same container, it is regarded as a martian source, 440 * and the same host but different containers are not. 441 */ 442 if (inet_lookup_ifaddr_rcu(net, src)) 443 return -EINVAL; 444 445 ok: 446 *itag = 0; 447 return 0; 448 } 449 450 full_check: 451 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag); 452 } 453 454 static inline __be32 sk_extract_addr(struct sockaddr *addr) 455 { 456 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 457 } 458 459 static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 460 { 461 struct nlattr *nla; 462 463 nla = (struct nlattr *) ((char *) mx + len); 464 nla->nla_type = type; 465 nla->nla_len = nla_attr_size(4); 466 *(u32 *) nla_data(nla) = value; 467 468 return len + nla_total_size(4); 469 } 470 471 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 472 struct fib_config *cfg) 473 { 474 __be32 addr; 475 int plen; 476 477 memset(cfg, 0, sizeof(*cfg)); 478 cfg->fc_nlinfo.nl_net = net; 479 480 if (rt->rt_dst.sa_family != AF_INET) 481 return -EAFNOSUPPORT; 482 483 /* 484 * Check mask for validity: 485 * a) it must be contiguous. 486 * b) destination must have all host bits clear. 487 * c) if application forgot to set correct family (AF_INET), 488 * reject request unless it is absolutely clear i.e. 489 * both family and mask are zero. 490 */ 491 plen = 32; 492 addr = sk_extract_addr(&rt->rt_dst); 493 if (!(rt->rt_flags & RTF_HOST)) { 494 __be32 mask = sk_extract_addr(&rt->rt_genmask); 495 496 if (rt->rt_genmask.sa_family != AF_INET) { 497 if (mask || rt->rt_genmask.sa_family) 498 return -EAFNOSUPPORT; 499 } 500 501 if (bad_mask(mask, addr)) 502 return -EINVAL; 503 504 plen = inet_mask_len(mask); 505 } 506 507 cfg->fc_dst_len = plen; 508 cfg->fc_dst = addr; 509 510 if (cmd != SIOCDELRT) { 511 cfg->fc_nlflags = NLM_F_CREATE; 512 cfg->fc_protocol = RTPROT_BOOT; 513 } 514 515 if (rt->rt_metric) 516 cfg->fc_priority = rt->rt_metric - 1; 517 518 if (rt->rt_flags & RTF_REJECT) { 519 cfg->fc_scope = RT_SCOPE_HOST; 520 cfg->fc_type = RTN_UNREACHABLE; 521 return 0; 522 } 523 524 cfg->fc_scope = RT_SCOPE_NOWHERE; 525 cfg->fc_type = RTN_UNICAST; 526 527 if (rt->rt_dev) { 528 char *colon; 529 struct net_device *dev; 530 char devname[IFNAMSIZ]; 531 532 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 533 return -EFAULT; 534 535 devname[IFNAMSIZ-1] = 0; 536 colon = strchr(devname, ':'); 537 if (colon) 538 *colon = 0; 539 dev = __dev_get_by_name(net, devname); 540 if (!dev) 541 return -ENODEV; 542 cfg->fc_oif = dev->ifindex; 543 cfg->fc_table = l3mdev_fib_table(dev); 544 if (colon) { 545 const struct in_ifaddr *ifa; 546 struct in_device *in_dev; 547 548 in_dev = __in_dev_get_rtnl(dev); 549 if (!in_dev) 550 return -ENODEV; 551 552 *colon = ':'; 553 554 rcu_read_lock(); 555 in_dev_for_each_ifa_rcu(ifa, in_dev) { 556 if (strcmp(ifa->ifa_label, devname) == 0) 557 break; 558 } 559 rcu_read_unlock(); 560 561 if (!ifa) 562 return -ENODEV; 563 cfg->fc_prefsrc = ifa->ifa_local; 564 } 565 } 566 567 addr = sk_extract_addr(&rt->rt_gateway); 568 if (rt->rt_gateway.sa_family == AF_INET && addr) { 569 unsigned int addr_type; 570 571 cfg->fc_gw4 = addr; 572 cfg->fc_gw_family = AF_INET; 573 addr_type = inet_addr_type_table(net, addr, cfg->fc_table); 574 if (rt->rt_flags & RTF_GATEWAY && 575 addr_type == RTN_UNICAST) 576 cfg->fc_scope = RT_SCOPE_UNIVERSE; 577 } 578 579 if (!cfg->fc_table) 580 cfg->fc_table = RT_TABLE_MAIN; 581 582 if (cmd == SIOCDELRT) 583 return 0; 584 585 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family) 586 return -EINVAL; 587 588 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 589 cfg->fc_scope = RT_SCOPE_LINK; 590 591 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 592 struct nlattr *mx; 593 int len = 0; 594 595 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL); 596 if (!mx) 597 return -ENOMEM; 598 599 if (rt->rt_flags & RTF_MTU) 600 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 601 602 if (rt->rt_flags & RTF_WINDOW) 603 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 604 605 if (rt->rt_flags & RTF_IRTT) 606 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 607 608 cfg->fc_mx = mx; 609 cfg->fc_mx_len = len; 610 } 611 612 return 0; 613 } 614 615 /* 616 * Handle IP routing ioctl calls. 617 * These are used to manipulate the routing tables 618 */ 619 int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt) 620 { 621 struct fib_config cfg; 622 int err; 623 624 switch (cmd) { 625 case SIOCADDRT: /* Add a route */ 626 case SIOCDELRT: /* Delete a route */ 627 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 628 return -EPERM; 629 630 rtnl_lock(); 631 err = rtentry_to_fib_config(net, cmd, rt, &cfg); 632 if (err == 0) { 633 struct fib_table *tb; 634 635 if (cmd == SIOCDELRT) { 636 tb = fib_get_table(net, cfg.fc_table); 637 if (tb) 638 err = fib_table_delete(net, tb, &cfg, 639 NULL); 640 else 641 err = -ESRCH; 642 } else { 643 tb = fib_new_table(net, cfg.fc_table); 644 if (tb) 645 err = fib_table_insert(net, tb, 646 &cfg, NULL); 647 else 648 err = -ENOBUFS; 649 } 650 651 /* allocated by rtentry_to_fib_config() */ 652 kfree(cfg.fc_mx); 653 } 654 rtnl_unlock(); 655 return err; 656 } 657 return -EINVAL; 658 } 659 660 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 661 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 }, 662 [RTA_DST] = { .type = NLA_U32 }, 663 [RTA_SRC] = { .type = NLA_U32 }, 664 [RTA_IIF] = { .type = NLA_U32 }, 665 [RTA_OIF] = { .type = NLA_U32 }, 666 [RTA_GATEWAY] = { .type = NLA_U32 }, 667 [RTA_PRIORITY] = { .type = NLA_U32 }, 668 [RTA_PREFSRC] = { .type = NLA_U32 }, 669 [RTA_METRICS] = { .type = NLA_NESTED }, 670 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 671 [RTA_FLOW] = { .type = NLA_U32 }, 672 [RTA_ENCAP_TYPE] = { .type = NLA_U16 }, 673 [RTA_ENCAP] = { .type = NLA_NESTED }, 674 [RTA_UID] = { .type = NLA_U32 }, 675 [RTA_MARK] = { .type = NLA_U32 }, 676 [RTA_TABLE] = { .type = NLA_U32 }, 677 [RTA_IP_PROTO] = { .type = NLA_U8 }, 678 [RTA_SPORT] = { .type = NLA_U16 }, 679 [RTA_DPORT] = { .type = NLA_U16 }, 680 [RTA_NH_ID] = { .type = NLA_U32 }, 681 }; 682 683 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, 684 struct netlink_ext_ack *extack) 685 { 686 struct rtvia *via; 687 int alen; 688 689 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) { 690 NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA"); 691 return -EINVAL; 692 } 693 694 via = nla_data(nla); 695 alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr); 696 697 switch (via->rtvia_family) { 698 case AF_INET: 699 if (alen != sizeof(__be32)) { 700 NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA"); 701 return -EINVAL; 702 } 703 cfg->fc_gw_family = AF_INET; 704 cfg->fc_gw4 = *((__be32 *)via->rtvia_addr); 705 break; 706 case AF_INET6: 707 #if IS_ENABLED(CONFIG_IPV6) 708 if (alen != sizeof(struct in6_addr)) { 709 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA"); 710 return -EINVAL; 711 } 712 cfg->fc_gw_family = AF_INET6; 713 cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr); 714 #else 715 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel"); 716 return -EINVAL; 717 #endif 718 break; 719 default: 720 NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA"); 721 return -EINVAL; 722 } 723 724 return 0; 725 } 726 727 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 728 struct nlmsghdr *nlh, struct fib_config *cfg, 729 struct netlink_ext_ack *extack) 730 { 731 bool has_gw = false, has_via = false; 732 struct nlattr *attr; 733 int err, remaining; 734 struct rtmsg *rtm; 735 736 err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX, 737 rtm_ipv4_policy, extack); 738 if (err < 0) 739 goto errout; 740 741 memset(cfg, 0, sizeof(*cfg)); 742 743 rtm = nlmsg_data(nlh); 744 745 if (!inet_validate_dscp(rtm->rtm_tos)) { 746 NL_SET_ERR_MSG(extack, 747 "Invalid dsfield (tos): ECN bits must be 0"); 748 err = -EINVAL; 749 goto errout; 750 } 751 cfg->fc_dscp = inet_dsfield_to_dscp(rtm->rtm_tos); 752 753 cfg->fc_dst_len = rtm->rtm_dst_len; 754 cfg->fc_table = rtm->rtm_table; 755 cfg->fc_protocol = rtm->rtm_protocol; 756 cfg->fc_scope = rtm->rtm_scope; 757 cfg->fc_type = rtm->rtm_type; 758 cfg->fc_flags = rtm->rtm_flags; 759 cfg->fc_nlflags = nlh->nlmsg_flags; 760 761 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid; 762 cfg->fc_nlinfo.nlh = nlh; 763 cfg->fc_nlinfo.nl_net = net; 764 765 if (cfg->fc_type > RTN_MAX) { 766 NL_SET_ERR_MSG(extack, "Invalid route type"); 767 err = -EINVAL; 768 goto errout; 769 } 770 771 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 772 switch (nla_type(attr)) { 773 case RTA_DST: 774 cfg->fc_dst = nla_get_be32(attr); 775 break; 776 case RTA_OIF: 777 cfg->fc_oif = nla_get_u32(attr); 778 break; 779 case RTA_GATEWAY: 780 has_gw = true; 781 cfg->fc_gw4 = nla_get_be32(attr); 782 if (cfg->fc_gw4) 783 cfg->fc_gw_family = AF_INET; 784 break; 785 case RTA_VIA: 786 has_via = true; 787 err = fib_gw_from_via(cfg, attr, extack); 788 if (err) 789 goto errout; 790 break; 791 case RTA_PRIORITY: 792 cfg->fc_priority = nla_get_u32(attr); 793 break; 794 case RTA_PREFSRC: 795 cfg->fc_prefsrc = nla_get_be32(attr); 796 break; 797 case RTA_METRICS: 798 cfg->fc_mx = nla_data(attr); 799 cfg->fc_mx_len = nla_len(attr); 800 break; 801 case RTA_MULTIPATH: 802 err = lwtunnel_valid_encap_type_attr(nla_data(attr), 803 nla_len(attr), 804 extack); 805 if (err < 0) 806 goto errout; 807 cfg->fc_mp = nla_data(attr); 808 cfg->fc_mp_len = nla_len(attr); 809 break; 810 case RTA_FLOW: 811 cfg->fc_flow = nla_get_u32(attr); 812 break; 813 case RTA_TABLE: 814 cfg->fc_table = nla_get_u32(attr); 815 break; 816 case RTA_ENCAP: 817 cfg->fc_encap = attr; 818 break; 819 case RTA_ENCAP_TYPE: 820 cfg->fc_encap_type = nla_get_u16(attr); 821 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, 822 extack); 823 if (err < 0) 824 goto errout; 825 break; 826 case RTA_NH_ID: 827 cfg->fc_nh_id = nla_get_u32(attr); 828 break; 829 } 830 } 831 832 if (cfg->fc_nh_id) { 833 if (cfg->fc_oif || cfg->fc_gw_family || 834 cfg->fc_encap || cfg->fc_mp) { 835 NL_SET_ERR_MSG(extack, 836 "Nexthop specification and nexthop id are mutually exclusive"); 837 return -EINVAL; 838 } 839 } 840 841 if (has_gw && has_via) { 842 NL_SET_ERR_MSG(extack, 843 "Nexthop configuration can not contain both GATEWAY and VIA"); 844 return -EINVAL; 845 } 846 847 if (!cfg->fc_table) 848 cfg->fc_table = RT_TABLE_MAIN; 849 850 return 0; 851 errout: 852 return err; 853 } 854 855 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, 856 struct netlink_ext_ack *extack) 857 { 858 struct net *net = sock_net(skb->sk); 859 struct fib_config cfg; 860 struct fib_table *tb; 861 int err; 862 863 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 864 if (err < 0) 865 goto errout; 866 867 if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) { 868 NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); 869 err = -EINVAL; 870 goto errout; 871 } 872 873 tb = fib_get_table(net, cfg.fc_table); 874 if (!tb) { 875 NL_SET_ERR_MSG(extack, "FIB table does not exist"); 876 err = -ESRCH; 877 goto errout; 878 } 879 880 err = fib_table_delete(net, tb, &cfg, extack); 881 errout: 882 return err; 883 } 884 885 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, 886 struct netlink_ext_ack *extack) 887 { 888 struct net *net = sock_net(skb->sk); 889 struct fib_config cfg; 890 struct fib_table *tb; 891 int err; 892 893 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 894 if (err < 0) 895 goto errout; 896 897 tb = fib_new_table(net, cfg.fc_table); 898 if (!tb) { 899 err = -ENOBUFS; 900 goto errout; 901 } 902 903 err = fib_table_insert(net, tb, &cfg, extack); 904 if (!err && cfg.fc_type == RTN_LOCAL) 905 net->ipv4.fib_has_custom_local_routes = true; 906 errout: 907 return err; 908 } 909 910 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 911 struct fib_dump_filter *filter, 912 struct netlink_callback *cb) 913 { 914 struct netlink_ext_ack *extack = cb->extack; 915 struct nlattr *tb[RTA_MAX + 1]; 916 struct rtmsg *rtm; 917 int err, i; 918 919 ASSERT_RTNL(); 920 921 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 922 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request"); 923 return -EINVAL; 924 } 925 926 rtm = nlmsg_data(nlh); 927 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos || 928 rtm->rtm_scope) { 929 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request"); 930 return -EINVAL; 931 } 932 933 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) { 934 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request"); 935 return -EINVAL; 936 } 937 if (rtm->rtm_flags & RTM_F_CLONED) 938 filter->dump_routes = false; 939 else 940 filter->dump_exceptions = false; 941 942 filter->flags = rtm->rtm_flags; 943 filter->protocol = rtm->rtm_protocol; 944 filter->rt_type = rtm->rtm_type; 945 filter->table_id = rtm->rtm_table; 946 947 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 948 rtm_ipv4_policy, extack); 949 if (err < 0) 950 return err; 951 952 for (i = 0; i <= RTA_MAX; ++i) { 953 int ifindex; 954 955 if (!tb[i]) 956 continue; 957 958 switch (i) { 959 case RTA_TABLE: 960 filter->table_id = nla_get_u32(tb[i]); 961 break; 962 case RTA_OIF: 963 ifindex = nla_get_u32(tb[i]); 964 filter->dev = __dev_get_by_index(net, ifindex); 965 if (!filter->dev) 966 return -ENODEV; 967 break; 968 default: 969 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request"); 970 return -EINVAL; 971 } 972 } 973 974 if (filter->flags || filter->protocol || filter->rt_type || 975 filter->table_id || filter->dev) { 976 filter->filter_set = 1; 977 cb->answer_flags = NLM_F_DUMP_FILTERED; 978 } 979 980 return 0; 981 } 982 EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req); 983 984 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 985 { 986 struct fib_dump_filter filter = { .dump_routes = true, 987 .dump_exceptions = true }; 988 const struct nlmsghdr *nlh = cb->nlh; 989 struct net *net = sock_net(skb->sk); 990 unsigned int h, s_h; 991 unsigned int e = 0, s_e; 992 struct fib_table *tb; 993 struct hlist_head *head; 994 int dumped = 0, err; 995 996 if (cb->strict_check) { 997 err = ip_valid_fib_dump_req(net, nlh, &filter, cb); 998 if (err < 0) 999 return err; 1000 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 1001 struct rtmsg *rtm = nlmsg_data(nlh); 1002 1003 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED); 1004 } 1005 1006 /* ipv4 does not use prefix flag */ 1007 if (filter.flags & RTM_F_PREFIX) 1008 return skb->len; 1009 1010 if (filter.table_id) { 1011 tb = fib_get_table(net, filter.table_id); 1012 if (!tb) { 1013 if (rtnl_msg_family(cb->nlh) != PF_INET) 1014 return skb->len; 1015 1016 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist"); 1017 return -ENOENT; 1018 } 1019 1020 rcu_read_lock(); 1021 err = fib_table_dump(tb, skb, cb, &filter); 1022 rcu_read_unlock(); 1023 return skb->len ? : err; 1024 } 1025 1026 s_h = cb->args[0]; 1027 s_e = cb->args[1]; 1028 1029 rcu_read_lock(); 1030 1031 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 1032 e = 0; 1033 head = &net->ipv4.fib_table_hash[h]; 1034 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 1035 if (e < s_e) 1036 goto next; 1037 if (dumped) 1038 memset(&cb->args[2], 0, sizeof(cb->args) - 1039 2 * sizeof(cb->args[0])); 1040 err = fib_table_dump(tb, skb, cb, &filter); 1041 if (err < 0) { 1042 if (likely(skb->len)) 1043 goto out; 1044 1045 goto out_err; 1046 } 1047 dumped = 1; 1048 next: 1049 e++; 1050 } 1051 } 1052 out: 1053 err = skb->len; 1054 out_err: 1055 rcu_read_unlock(); 1056 1057 cb->args[1] = e; 1058 cb->args[0] = h; 1059 1060 return err; 1061 } 1062 1063 /* Prepare and feed intra-kernel routing request. 1064 * Really, it should be netlink message, but :-( netlink 1065 * can be not configured, so that we feed it directly 1066 * to fib engine. It is legal, because all events occur 1067 * only when netlink is already locked. 1068 */ 1069 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, 1070 struct in_ifaddr *ifa, u32 rt_priority) 1071 { 1072 struct net *net = dev_net(ifa->ifa_dev->dev); 1073 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev); 1074 struct fib_table *tb; 1075 struct fib_config cfg = { 1076 .fc_protocol = RTPROT_KERNEL, 1077 .fc_type = type, 1078 .fc_dst = dst, 1079 .fc_dst_len = dst_len, 1080 .fc_priority = rt_priority, 1081 .fc_prefsrc = ifa->ifa_local, 1082 .fc_oif = ifa->ifa_dev->dev->ifindex, 1083 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 1084 .fc_nlinfo = { 1085 .nl_net = net, 1086 }, 1087 }; 1088 1089 if (!tb_id) 1090 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL; 1091 1092 tb = fib_new_table(net, tb_id); 1093 if (!tb) 1094 return; 1095 1096 cfg.fc_table = tb->tb_id; 1097 1098 if (type != RTN_LOCAL) 1099 cfg.fc_scope = RT_SCOPE_LINK; 1100 else 1101 cfg.fc_scope = RT_SCOPE_HOST; 1102 1103 if (cmd == RTM_NEWROUTE) 1104 fib_table_insert(net, tb, &cfg, NULL); 1105 else 1106 fib_table_delete(net, tb, &cfg, NULL); 1107 } 1108 1109 void fib_add_ifaddr(struct in_ifaddr *ifa) 1110 { 1111 struct in_device *in_dev = ifa->ifa_dev; 1112 struct net_device *dev = in_dev->dev; 1113 struct in_ifaddr *prim = ifa; 1114 __be32 mask = ifa->ifa_mask; 1115 __be32 addr = ifa->ifa_local; 1116 __be32 prefix = ifa->ifa_address & mask; 1117 1118 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1119 prim = inet_ifa_byprefix(in_dev, prefix, mask); 1120 if (!prim) { 1121 pr_warn("%s: bug: prim == NULL\n", __func__); 1122 return; 1123 } 1124 } 1125 1126 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0); 1127 1128 if (!(dev->flags & IFF_UP)) 1129 return; 1130 1131 /* Add broadcast address, if it is explicitly assigned. */ 1132 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) { 1133 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1134 prim, 0); 1135 arp_invalidate(dev, ifa->ifa_broadcast, false); 1136 } 1137 1138 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 1139 (prefix != addr || ifa->ifa_prefixlen < 32)) { 1140 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1141 fib_magic(RTM_NEWROUTE, 1142 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1143 prefix, ifa->ifa_prefixlen, prim, 1144 ifa->ifa_rt_priority); 1145 1146 /* Add the network broadcast address, when it makes sense */ 1147 if (ifa->ifa_prefixlen < 31) { 1148 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 1149 32, prim, 0); 1150 arp_invalidate(dev, prefix | ~mask, false); 1151 } 1152 } 1153 } 1154 1155 void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric) 1156 { 1157 __be32 prefix = ifa->ifa_address & ifa->ifa_mask; 1158 struct in_device *in_dev = ifa->ifa_dev; 1159 struct net_device *dev = in_dev->dev; 1160 1161 if (!(dev->flags & IFF_UP) || 1162 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) || 1163 ipv4_is_zeronet(prefix) || 1164 (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32)) 1165 return; 1166 1167 /* add the new */ 1168 fib_magic(RTM_NEWROUTE, 1169 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1170 prefix, ifa->ifa_prefixlen, ifa, new_metric); 1171 1172 /* delete the old */ 1173 fib_magic(RTM_DELROUTE, 1174 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1175 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority); 1176 } 1177 1178 /* Delete primary or secondary address. 1179 * Optionally, on secondary address promotion consider the addresses 1180 * from subnet iprim as deleted, even if they are in device list. 1181 * In this case the secondary ifa can be in device list. 1182 */ 1183 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 1184 { 1185 struct in_device *in_dev = ifa->ifa_dev; 1186 struct net_device *dev = in_dev->dev; 1187 struct in_ifaddr *ifa1; 1188 struct in_ifaddr *prim = ifa, *prim1 = NULL; 1189 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 1190 __be32 any = ifa->ifa_address & ifa->ifa_mask; 1191 #define LOCAL_OK 1 1192 #define BRD_OK 2 1193 #define BRD0_OK 4 1194 #define BRD1_OK 8 1195 unsigned int ok = 0; 1196 int subnet = 0; /* Primary network */ 1197 int gone = 1; /* Address is missing */ 1198 int same_prefsrc = 0; /* Another primary with same IP */ 1199 1200 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1201 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 1202 if (!prim) { 1203 /* if the device has been deleted, we don't perform 1204 * address promotion 1205 */ 1206 if (!in_dev->dead) 1207 pr_warn("%s: bug: prim == NULL\n", __func__); 1208 return; 1209 } 1210 if (iprim && iprim != prim) { 1211 pr_warn("%s: bug: iprim != prim\n", __func__); 1212 return; 1213 } 1214 } else if (!ipv4_is_zeronet(any) && 1215 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 1216 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1217 fib_magic(RTM_DELROUTE, 1218 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1219 any, ifa->ifa_prefixlen, prim, 0); 1220 subnet = 1; 1221 } 1222 1223 if (in_dev->dead) 1224 goto no_promotions; 1225 1226 /* Deletion is more complicated than add. 1227 * We should take care of not to delete too much :-) 1228 * 1229 * Scan address list to be sure that addresses are really gone. 1230 */ 1231 rcu_read_lock(); 1232 in_dev_for_each_ifa_rcu(ifa1, in_dev) { 1233 if (ifa1 == ifa) { 1234 /* promotion, keep the IP */ 1235 gone = 0; 1236 continue; 1237 } 1238 /* Ignore IFAs from our subnet */ 1239 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 1240 inet_ifa_match(ifa1->ifa_address, iprim)) 1241 continue; 1242 1243 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 1244 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 1245 /* Another address from our subnet? */ 1246 if (ifa1->ifa_mask == prim->ifa_mask && 1247 inet_ifa_match(ifa1->ifa_address, prim)) 1248 prim1 = prim; 1249 else { 1250 /* We reached the secondaries, so 1251 * same_prefsrc should be determined. 1252 */ 1253 if (!same_prefsrc) 1254 continue; 1255 /* Search new prim1 if ifa1 is not 1256 * using the current prim1 1257 */ 1258 if (!prim1 || 1259 ifa1->ifa_mask != prim1->ifa_mask || 1260 !inet_ifa_match(ifa1->ifa_address, prim1)) 1261 prim1 = inet_ifa_byprefix(in_dev, 1262 ifa1->ifa_address, 1263 ifa1->ifa_mask); 1264 if (!prim1) 1265 continue; 1266 if (prim1->ifa_local != prim->ifa_local) 1267 continue; 1268 } 1269 } else { 1270 if (prim->ifa_local != ifa1->ifa_local) 1271 continue; 1272 prim1 = ifa1; 1273 if (prim != prim1) 1274 same_prefsrc = 1; 1275 } 1276 if (ifa->ifa_local == ifa1->ifa_local) 1277 ok |= LOCAL_OK; 1278 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 1279 ok |= BRD_OK; 1280 if (brd == ifa1->ifa_broadcast) 1281 ok |= BRD1_OK; 1282 if (any == ifa1->ifa_broadcast) 1283 ok |= BRD0_OK; 1284 /* primary has network specific broadcasts */ 1285 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 1286 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 1287 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 1288 1289 if (!ipv4_is_zeronet(any1)) { 1290 if (ifa->ifa_broadcast == brd1 || 1291 ifa->ifa_broadcast == any1) 1292 ok |= BRD_OK; 1293 if (brd == brd1 || brd == any1) 1294 ok |= BRD1_OK; 1295 if (any == brd1 || any == any1) 1296 ok |= BRD0_OK; 1297 } 1298 } 1299 } 1300 rcu_read_unlock(); 1301 1302 no_promotions: 1303 if (!(ok & BRD_OK)) 1304 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1305 prim, 0); 1306 if (subnet && ifa->ifa_prefixlen < 31) { 1307 if (!(ok & BRD1_OK)) 1308 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, 1309 prim, 0); 1310 if (!(ok & BRD0_OK)) 1311 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, 1312 prim, 0); 1313 } 1314 if (!(ok & LOCAL_OK)) { 1315 unsigned int addr_type; 1316 1317 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0); 1318 1319 /* Check, that this local address finally disappeared. */ 1320 addr_type = inet_addr_type_dev_table(dev_net(dev), dev, 1321 ifa->ifa_local); 1322 if (gone && addr_type != RTN_LOCAL) { 1323 /* And the last, but not the least thing. 1324 * We must flush stray FIB entries. 1325 * 1326 * First of all, we scan fib_info list searching 1327 * for stray nexthop entries, then ignite fib_flush. 1328 */ 1329 if (fib_sync_down_addr(dev, ifa->ifa_local)) 1330 fib_flush(dev_net(dev)); 1331 } 1332 } 1333 #undef LOCAL_OK 1334 #undef BRD_OK 1335 #undef BRD0_OK 1336 #undef BRD1_OK 1337 } 1338 1339 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn) 1340 { 1341 1342 struct fib_result res; 1343 struct flowi4 fl4 = { 1344 .flowi4_mark = frn->fl_mark, 1345 .daddr = frn->fl_addr, 1346 .flowi4_tos = frn->fl_tos, 1347 .flowi4_scope = frn->fl_scope, 1348 }; 1349 struct fib_table *tb; 1350 1351 rcu_read_lock(); 1352 1353 tb = fib_get_table(net, frn->tb_id_in); 1354 1355 frn->err = -ENOENT; 1356 if (tb) { 1357 local_bh_disable(); 1358 1359 frn->tb_id = tb->tb_id; 1360 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 1361 1362 if (!frn->err) { 1363 frn->prefixlen = res.prefixlen; 1364 frn->nh_sel = res.nh_sel; 1365 frn->type = res.type; 1366 frn->scope = res.scope; 1367 } 1368 local_bh_enable(); 1369 } 1370 1371 rcu_read_unlock(); 1372 } 1373 1374 static void nl_fib_input(struct sk_buff *skb) 1375 { 1376 struct net *net; 1377 struct fib_result_nl *frn; 1378 struct nlmsghdr *nlh; 1379 u32 portid; 1380 1381 net = sock_net(skb->sk); 1382 nlh = nlmsg_hdr(skb); 1383 if (skb->len < nlmsg_total_size(sizeof(*frn)) || 1384 skb->len < nlh->nlmsg_len || 1385 nlmsg_len(nlh) < sizeof(*frn)) 1386 return; 1387 1388 skb = netlink_skb_clone(skb, GFP_KERNEL); 1389 if (!skb) 1390 return; 1391 nlh = nlmsg_hdr(skb); 1392 1393 frn = nlmsg_data(nlh); 1394 nl_fib_lookup(net, frn); 1395 1396 portid = NETLINK_CB(skb).portid; /* netlink portid */ 1397 NETLINK_CB(skb).portid = 0; /* from kernel */ 1398 NETLINK_CB(skb).dst_group = 0; /* unicast */ 1399 nlmsg_unicast(net->ipv4.fibnl, skb, portid); 1400 } 1401 1402 static int __net_init nl_fib_lookup_init(struct net *net) 1403 { 1404 struct sock *sk; 1405 struct netlink_kernel_cfg cfg = { 1406 .input = nl_fib_input, 1407 }; 1408 1409 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg); 1410 if (!sk) 1411 return -EAFNOSUPPORT; 1412 net->ipv4.fibnl = sk; 1413 return 0; 1414 } 1415 1416 static void nl_fib_lookup_exit(struct net *net) 1417 { 1418 netlink_kernel_release(net->ipv4.fibnl); 1419 net->ipv4.fibnl = NULL; 1420 } 1421 1422 static void fib_disable_ip(struct net_device *dev, unsigned long event, 1423 bool force) 1424 { 1425 if (fib_sync_down_dev(dev, event, force)) 1426 fib_flush(dev_net(dev)); 1427 else 1428 rt_cache_flush(dev_net(dev)); 1429 arp_ifdown(dev); 1430 } 1431 1432 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 1433 { 1434 struct in_ifaddr *ifa = ptr; 1435 struct net_device *dev = ifa->ifa_dev->dev; 1436 struct net *net = dev_net(dev); 1437 1438 switch (event) { 1439 case NETDEV_UP: 1440 fib_add_ifaddr(ifa); 1441 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1442 fib_sync_up(dev, RTNH_F_DEAD); 1443 #endif 1444 atomic_inc(&net->ipv4.dev_addr_genid); 1445 rt_cache_flush(dev_net(dev)); 1446 break; 1447 case NETDEV_DOWN: 1448 fib_del_ifaddr(ifa, NULL); 1449 atomic_inc(&net->ipv4.dev_addr_genid); 1450 if (!ifa->ifa_dev->ifa_list) { 1451 /* Last address was deleted from this interface. 1452 * Disable IP. 1453 */ 1454 fib_disable_ip(dev, event, true); 1455 } else { 1456 rt_cache_flush(dev_net(dev)); 1457 } 1458 break; 1459 } 1460 return NOTIFY_DONE; 1461 } 1462 1463 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1464 { 1465 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1466 struct netdev_notifier_changeupper_info *upper_info = ptr; 1467 struct netdev_notifier_info_ext *info_ext = ptr; 1468 struct in_device *in_dev; 1469 struct net *net = dev_net(dev); 1470 struct in_ifaddr *ifa; 1471 unsigned int flags; 1472 1473 if (event == NETDEV_UNREGISTER) { 1474 fib_disable_ip(dev, event, true); 1475 rt_flush_dev(dev); 1476 return NOTIFY_DONE; 1477 } 1478 1479 in_dev = __in_dev_get_rtnl(dev); 1480 if (!in_dev) 1481 return NOTIFY_DONE; 1482 1483 switch (event) { 1484 case NETDEV_UP: 1485 in_dev_for_each_ifa_rtnl(ifa, in_dev) { 1486 fib_add_ifaddr(ifa); 1487 } 1488 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1489 fib_sync_up(dev, RTNH_F_DEAD); 1490 #endif 1491 atomic_inc(&net->ipv4.dev_addr_genid); 1492 rt_cache_flush(net); 1493 break; 1494 case NETDEV_DOWN: 1495 fib_disable_ip(dev, event, false); 1496 break; 1497 case NETDEV_CHANGE: 1498 flags = dev_get_flags(dev); 1499 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1500 fib_sync_up(dev, RTNH_F_LINKDOWN); 1501 else 1502 fib_sync_down_dev(dev, event, false); 1503 rt_cache_flush(net); 1504 break; 1505 case NETDEV_CHANGEMTU: 1506 fib_sync_mtu(dev, info_ext->ext.mtu); 1507 rt_cache_flush(net); 1508 break; 1509 case NETDEV_CHANGEUPPER: 1510 upper_info = ptr; 1511 /* flush all routes if dev is linked to or unlinked from 1512 * an L3 master device (e.g., VRF) 1513 */ 1514 if (upper_info->upper_dev && 1515 netif_is_l3_master(upper_info->upper_dev)) 1516 fib_disable_ip(dev, NETDEV_DOWN, true); 1517 break; 1518 } 1519 return NOTIFY_DONE; 1520 } 1521 1522 static struct notifier_block fib_inetaddr_notifier = { 1523 .notifier_call = fib_inetaddr_event, 1524 }; 1525 1526 static struct notifier_block fib_netdev_notifier = { 1527 .notifier_call = fib_netdev_event, 1528 }; 1529 1530 static int __net_init ip_fib_net_init(struct net *net) 1531 { 1532 int err; 1533 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1534 1535 err = fib4_notifier_init(net); 1536 if (err) 1537 return err; 1538 1539 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1540 /* Default to 3-tuple */ 1541 net->ipv4.sysctl_fib_multipath_hash_fields = 1542 FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK; 1543 #endif 1544 1545 /* Avoid false sharing : Use at least a full cache line */ 1546 size = max_t(size_t, size, L1_CACHE_BYTES); 1547 1548 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1549 if (!net->ipv4.fib_table_hash) { 1550 err = -ENOMEM; 1551 goto err_table_hash_alloc; 1552 } 1553 1554 err = fib4_rules_init(net); 1555 if (err < 0) 1556 goto err_rules_init; 1557 return 0; 1558 1559 err_rules_init: 1560 kfree(net->ipv4.fib_table_hash); 1561 err_table_hash_alloc: 1562 fib4_notifier_exit(net); 1563 return err; 1564 } 1565 1566 static void ip_fib_net_exit(struct net *net) 1567 { 1568 int i; 1569 1570 ASSERT_RTNL(); 1571 #ifdef CONFIG_IP_MULTIPLE_TABLES 1572 RCU_INIT_POINTER(net->ipv4.fib_main, NULL); 1573 RCU_INIT_POINTER(net->ipv4.fib_default, NULL); 1574 #endif 1575 /* Destroy the tables in reverse order to guarantee that the 1576 * local table, ID 255, is destroyed before the main table, ID 1577 * 254. This is necessary as the local table may contain 1578 * references to data contained in the main table. 1579 */ 1580 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) { 1581 struct hlist_head *head = &net->ipv4.fib_table_hash[i]; 1582 struct hlist_node *tmp; 1583 struct fib_table *tb; 1584 1585 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) { 1586 hlist_del(&tb->tb_hlist); 1587 fib_table_flush(net, tb, true); 1588 fib_free_table(tb); 1589 } 1590 } 1591 1592 #ifdef CONFIG_IP_MULTIPLE_TABLES 1593 fib4_rules_exit(net); 1594 #endif 1595 1596 kfree(net->ipv4.fib_table_hash); 1597 fib4_notifier_exit(net); 1598 } 1599 1600 static int __net_init fib_net_init(struct net *net) 1601 { 1602 int error; 1603 1604 #ifdef CONFIG_IP_ROUTE_CLASSID 1605 atomic_set(&net->ipv4.fib_num_tclassid_users, 0); 1606 #endif 1607 error = ip_fib_net_init(net); 1608 if (error < 0) 1609 goto out; 1610 error = nl_fib_lookup_init(net); 1611 if (error < 0) 1612 goto out_nlfl; 1613 error = fib_proc_init(net); 1614 if (error < 0) 1615 goto out_proc; 1616 out: 1617 return error; 1618 1619 out_proc: 1620 nl_fib_lookup_exit(net); 1621 out_nlfl: 1622 rtnl_lock(); 1623 ip_fib_net_exit(net); 1624 rtnl_unlock(); 1625 goto out; 1626 } 1627 1628 static void __net_exit fib_net_exit(struct net *net) 1629 { 1630 fib_proc_exit(net); 1631 nl_fib_lookup_exit(net); 1632 } 1633 1634 static void __net_exit fib_net_exit_batch(struct list_head *net_list) 1635 { 1636 struct net *net; 1637 1638 rtnl_lock(); 1639 list_for_each_entry(net, net_list, exit_list) 1640 ip_fib_net_exit(net); 1641 1642 rtnl_unlock(); 1643 } 1644 1645 static struct pernet_operations fib_net_ops = { 1646 .init = fib_net_init, 1647 .exit = fib_net_exit, 1648 .exit_batch = fib_net_exit_batch, 1649 }; 1650 1651 void __init ip_fib_init(void) 1652 { 1653 fib_trie_init(); 1654 1655 register_pernet_subsys(&fib_net_ops); 1656 1657 register_netdevice_notifier(&fib_netdev_notifier); 1658 register_inetaddr_notifier(&fib_inetaddr_notifier); 1659 1660 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0); 1661 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0); 1662 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0); 1663 } 1664