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 52static 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 70fail: 71 fib_free_table(main_table); 72 return -ENOMEM; 73} 74#else 75 76struct 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} 109EXPORT_SYMBOL_GPL(fib_new_table); 110 111/* caller must hold either rtnl or rcu read lock */ 112struct 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 132static 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 152int 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 184void 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 */ 206static 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 237unsigned 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} 241EXPORT_SYMBOL(inet_addr_type_table); 242 243unsigned int inet_addr_type(struct net *net, __be32 addr) 244{ 245 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL); 246} 247EXPORT_SYMBOL(inet_addr_type); 248 249unsigned 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} 256EXPORT_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 */ 261unsigned 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} 269EXPORT_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 309bool 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} 334EXPORT_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 */ 344static 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 408last_resort: 409 if (rpf) 410 goto e_rpf; 411 *itag = 0; 412 return 0; 413 414e_inval: 415 return -EINVAL; 416e_rpf: 417 return -EXDEV; 418} 419 420/* Ignore rp_filter for packets protected by IPsec. */ 421int 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 445ok: 446 *itag = 0; 447 return 0; 448 } 449 450full_check: 451 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag); 452} 453 454static inline __be32 sk_extract_addr(struct sockaddr *addr) 455{ 456 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 457} 458 459static 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 471static 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 */ 619int 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 660const 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 683int 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 727static 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; 851errout: 852 return err; 853} 854 855static 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); 881errout: 882 return err; 883} 884 885static 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; 906errout: 907 return err; 908} 909 910int 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 if (filter->rtnl_held) 920 ASSERT_RTNL(); 921 922 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 923 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request"); 924 return -EINVAL; 925 } 926 927 rtm = nlmsg_data(nlh); 928 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos || 929 rtm->rtm_scope) { 930 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request"); 931 return -EINVAL; 932 } 933 934 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) { 935 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request"); 936 return -EINVAL; 937 } 938 if (rtm->rtm_flags & RTM_F_CLONED) 939 filter->dump_routes = false; 940 else 941 filter->dump_exceptions = false; 942 943 filter->flags = rtm->rtm_flags; 944 filter->protocol = rtm->rtm_protocol; 945 filter->rt_type = rtm->rtm_type; 946 filter->table_id = rtm->rtm_table; 947 948 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 949 rtm_ipv4_policy, extack); 950 if (err < 0) 951 return err; 952 953 for (i = 0; i <= RTA_MAX; ++i) { 954 int ifindex; 955 956 if (!tb[i]) 957 continue; 958 959 switch (i) { 960 case RTA_TABLE: 961 filter->table_id = nla_get_u32(tb[i]); 962 break; 963 case RTA_OIF: 964 ifindex = nla_get_u32(tb[i]); 965 if (filter->rtnl_held) 966 filter->dev = __dev_get_by_index(net, ifindex); 967 else 968 filter->dev = dev_get_by_index_rcu(net, ifindex); 969 if (!filter->dev) 970 return -ENODEV; 971 break; 972 default: 973 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request"); 974 return -EINVAL; 975 } 976 } 977 978 if (filter->flags || filter->protocol || filter->rt_type || 979 filter->table_id || filter->dev) { 980 filter->filter_set = 1; 981 cb->answer_flags = NLM_F_DUMP_FILTERED; 982 } 983 984 return 0; 985} 986EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req); 987 988static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 989{ 990 struct fib_dump_filter filter = { 991 .dump_routes = true, 992 .dump_exceptions = true, 993 .rtnl_held = false, 994 }; 995 const struct nlmsghdr *nlh = cb->nlh; 996 struct net *net = sock_net(skb->sk); 997 unsigned int h, s_h; 998 unsigned int e = 0, s_e; 999 struct fib_table *tb; 1000 struct hlist_head *head; 1001 int dumped = 0, err = 0; 1002 1003 rcu_read_lock(); 1004 if (cb->strict_check) { 1005 err = ip_valid_fib_dump_req(net, nlh, &filter, cb); 1006 if (err < 0) 1007 goto unlock; 1008 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 1009 struct rtmsg *rtm = nlmsg_data(nlh); 1010 1011 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED); 1012 } 1013 1014 /* ipv4 does not use prefix flag */ 1015 if (filter.flags & RTM_F_PREFIX) 1016 goto unlock; 1017 1018 if (filter.table_id) { 1019 tb = fib_get_table(net, filter.table_id); 1020 if (!tb) { 1021 if (rtnl_msg_family(cb->nlh) != PF_INET) 1022 goto unlock; 1023 1024 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist"); 1025 err = -ENOENT; 1026 goto unlock; 1027 } 1028 err = fib_table_dump(tb, skb, cb, &filter); 1029 goto unlock; 1030 } 1031 1032 s_h = cb->args[0]; 1033 s_e = cb->args[1]; 1034 1035 err = 0; 1036 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 1037 e = 0; 1038 head = &net->ipv4.fib_table_hash[h]; 1039 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 1040 if (e < s_e) 1041 goto next; 1042 if (dumped) 1043 memset(&cb->args[2], 0, sizeof(cb->args) - 1044 2 * sizeof(cb->args[0])); 1045 err = fib_table_dump(tb, skb, cb, &filter); 1046 if (err < 0) 1047 goto out; 1048 dumped = 1; 1049next: 1050 e++; 1051 } 1052 } 1053 1054 /* Don't let NLM_DONE coalesce into a message, even if it could. 1055 * Some user space expects NLM_DONE in a separate recv(). 1056 */ 1057 err = skb->len; 1058out: 1059 1060 cb->args[1] = e; 1061 cb->args[0] = h; 1062 1063unlock: 1064 rcu_read_unlock(); 1065 return err; 1066} 1067 1068/* Prepare and feed intra-kernel routing request. 1069 * Really, it should be netlink message, but :-( netlink 1070 * can be not configured, so that we feed it directly 1071 * to fib engine. It is legal, because all events occur 1072 * only when netlink is already locked. 1073 */ 1074static void fib_magic(int cmd, int type, __be32 dst, int dst_len, 1075 struct in_ifaddr *ifa, u32 rt_priority) 1076{ 1077 struct net *net = dev_net(ifa->ifa_dev->dev); 1078 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev); 1079 struct fib_table *tb; 1080 struct fib_config cfg = { 1081 .fc_protocol = RTPROT_KERNEL, 1082 .fc_type = type, 1083 .fc_dst = dst, 1084 .fc_dst_len = dst_len, 1085 .fc_priority = rt_priority, 1086 .fc_prefsrc = ifa->ifa_local, 1087 .fc_oif = ifa->ifa_dev->dev->ifindex, 1088 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 1089 .fc_nlinfo = { 1090 .nl_net = net, 1091 }, 1092 }; 1093 1094 if (!tb_id) 1095 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL; 1096 1097 tb = fib_new_table(net, tb_id); 1098 if (!tb) 1099 return; 1100 1101 cfg.fc_table = tb->tb_id; 1102 1103 if (type != RTN_LOCAL) 1104 cfg.fc_scope = RT_SCOPE_LINK; 1105 else 1106 cfg.fc_scope = RT_SCOPE_HOST; 1107 1108 if (cmd == RTM_NEWROUTE) 1109 fib_table_insert(net, tb, &cfg, NULL); 1110 else 1111 fib_table_delete(net, tb, &cfg, NULL); 1112} 1113 1114void fib_add_ifaddr(struct in_ifaddr *ifa) 1115{ 1116 struct in_device *in_dev = ifa->ifa_dev; 1117 struct net_device *dev = in_dev->dev; 1118 struct in_ifaddr *prim = ifa; 1119 __be32 mask = ifa->ifa_mask; 1120 __be32 addr = ifa->ifa_local; 1121 __be32 prefix = ifa->ifa_address & mask; 1122 1123 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1124 prim = inet_ifa_byprefix(in_dev, prefix, mask); 1125 if (!prim) { 1126 pr_warn("%s: bug: prim == NULL\n", __func__); 1127 return; 1128 } 1129 } 1130 1131 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0); 1132 1133 if (!(dev->flags & IFF_UP)) 1134 return; 1135 1136 /* Add broadcast address, if it is explicitly assigned. */ 1137 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) { 1138 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1139 prim, 0); 1140 arp_invalidate(dev, ifa->ifa_broadcast, false); 1141 } 1142 1143 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 1144 (prefix != addr || ifa->ifa_prefixlen < 32)) { 1145 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1146 fib_magic(RTM_NEWROUTE, 1147 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1148 prefix, ifa->ifa_prefixlen, prim, 1149 ifa->ifa_rt_priority); 1150 1151 /* Add the network broadcast address, when it makes sense */ 1152 if (ifa->ifa_prefixlen < 31) { 1153 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 1154 32, prim, 0); 1155 arp_invalidate(dev, prefix | ~mask, false); 1156 } 1157 } 1158} 1159 1160void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric) 1161{ 1162 __be32 prefix = ifa->ifa_address & ifa->ifa_mask; 1163 struct in_device *in_dev = ifa->ifa_dev; 1164 struct net_device *dev = in_dev->dev; 1165 1166 if (!(dev->flags & IFF_UP) || 1167 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) || 1168 ipv4_is_zeronet(prefix) || 1169 (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32)) 1170 return; 1171 1172 /* add the new */ 1173 fib_magic(RTM_NEWROUTE, 1174 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1175 prefix, ifa->ifa_prefixlen, ifa, new_metric); 1176 1177 /* delete the old */ 1178 fib_magic(RTM_DELROUTE, 1179 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1180 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority); 1181} 1182 1183/* Delete primary or secondary address. 1184 * Optionally, on secondary address promotion consider the addresses 1185 * from subnet iprim as deleted, even if they are in device list. 1186 * In this case the secondary ifa can be in device list. 1187 */ 1188void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 1189{ 1190 struct in_device *in_dev = ifa->ifa_dev; 1191 struct net_device *dev = in_dev->dev; 1192 struct in_ifaddr *ifa1; 1193 struct in_ifaddr *prim = ifa, *prim1 = NULL; 1194 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 1195 __be32 any = ifa->ifa_address & ifa->ifa_mask; 1196#define LOCAL_OK 1 1197#define BRD_OK 2 1198#define BRD0_OK 4 1199#define BRD1_OK 8 1200 unsigned int ok = 0; 1201 int subnet = 0; /* Primary network */ 1202 int gone = 1; /* Address is missing */ 1203 int same_prefsrc = 0; /* Another primary with same IP */ 1204 1205 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1206 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 1207 if (!prim) { 1208 /* if the device has been deleted, we don't perform 1209 * address promotion 1210 */ 1211 if (!in_dev->dead) 1212 pr_warn("%s: bug: prim == NULL\n", __func__); 1213 return; 1214 } 1215 if (iprim && iprim != prim) { 1216 pr_warn("%s: bug: iprim != prim\n", __func__); 1217 return; 1218 } 1219 } else if (!ipv4_is_zeronet(any) && 1220 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 1221 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1222 fib_magic(RTM_DELROUTE, 1223 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1224 any, ifa->ifa_prefixlen, prim, 0); 1225 subnet = 1; 1226 } 1227 1228 if (in_dev->dead) 1229 goto no_promotions; 1230 1231 /* Deletion is more complicated than add. 1232 * We should take care of not to delete too much :-) 1233 * 1234 * Scan address list to be sure that addresses are really gone. 1235 */ 1236 rcu_read_lock(); 1237 in_dev_for_each_ifa_rcu(ifa1, in_dev) { 1238 if (ifa1 == ifa) { 1239 /* promotion, keep the IP */ 1240 gone = 0; 1241 continue; 1242 } 1243 /* Ignore IFAs from our subnet */ 1244 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 1245 inet_ifa_match(ifa1->ifa_address, iprim)) 1246 continue; 1247 1248 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 1249 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 1250 /* Another address from our subnet? */ 1251 if (ifa1->ifa_mask == prim->ifa_mask && 1252 inet_ifa_match(ifa1->ifa_address, prim)) 1253 prim1 = prim; 1254 else { 1255 /* We reached the secondaries, so 1256 * same_prefsrc should be determined. 1257 */ 1258 if (!same_prefsrc) 1259 continue; 1260 /* Search new prim1 if ifa1 is not 1261 * using the current prim1 1262 */ 1263 if (!prim1 || 1264 ifa1->ifa_mask != prim1->ifa_mask || 1265 !inet_ifa_match(ifa1->ifa_address, prim1)) 1266 prim1 = inet_ifa_byprefix(in_dev, 1267 ifa1->ifa_address, 1268 ifa1->ifa_mask); 1269 if (!prim1) 1270 continue; 1271 if (prim1->ifa_local != prim->ifa_local) 1272 continue; 1273 } 1274 } else { 1275 if (prim->ifa_local != ifa1->ifa_local) 1276 continue; 1277 prim1 = ifa1; 1278 if (prim != prim1) 1279 same_prefsrc = 1; 1280 } 1281 if (ifa->ifa_local == ifa1->ifa_local) 1282 ok |= LOCAL_OK; 1283 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 1284 ok |= BRD_OK; 1285 if (brd == ifa1->ifa_broadcast) 1286 ok |= BRD1_OK; 1287 if (any == ifa1->ifa_broadcast) 1288 ok |= BRD0_OK; 1289 /* primary has network specific broadcasts */ 1290 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 1291 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 1292 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 1293 1294 if (!ipv4_is_zeronet(any1)) { 1295 if (ifa->ifa_broadcast == brd1 || 1296 ifa->ifa_broadcast == any1) 1297 ok |= BRD_OK; 1298 if (brd == brd1 || brd == any1) 1299 ok |= BRD1_OK; 1300 if (any == brd1 || any == any1) 1301 ok |= BRD0_OK; 1302 } 1303 } 1304 } 1305 rcu_read_unlock(); 1306 1307no_promotions: 1308 if (!(ok & BRD_OK)) 1309 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1310 prim, 0); 1311 if (subnet && ifa->ifa_prefixlen < 31) { 1312 if (!(ok & BRD1_OK)) 1313 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, 1314 prim, 0); 1315 if (!(ok & BRD0_OK)) 1316 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, 1317 prim, 0); 1318 } 1319 if (!(ok & LOCAL_OK)) { 1320 unsigned int addr_type; 1321 1322 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0); 1323 1324 /* Check, that this local address finally disappeared. */ 1325 addr_type = inet_addr_type_dev_table(dev_net(dev), dev, 1326 ifa->ifa_local); 1327 if (gone && addr_type != RTN_LOCAL) { 1328 /* And the last, but not the least thing. 1329 * We must flush stray FIB entries. 1330 * 1331 * First of all, we scan fib_info list searching 1332 * for stray nexthop entries, then ignite fib_flush. 1333 */ 1334 if (fib_sync_down_addr(dev, ifa->ifa_local)) 1335 fib_flush(dev_net(dev)); 1336 } 1337 } 1338#undef LOCAL_OK 1339#undef BRD_OK 1340#undef BRD0_OK 1341#undef BRD1_OK 1342} 1343 1344static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn) 1345{ 1346 1347 struct fib_result res; 1348 struct flowi4 fl4 = { 1349 .flowi4_mark = frn->fl_mark, 1350 .daddr = frn->fl_addr, 1351 .flowi4_tos = frn->fl_tos, 1352 .flowi4_scope = frn->fl_scope, 1353 }; 1354 struct fib_table *tb; 1355 1356 rcu_read_lock(); 1357 1358 tb = fib_get_table(net, frn->tb_id_in); 1359 1360 frn->err = -ENOENT; 1361 if (tb) { 1362 local_bh_disable(); 1363 1364 frn->tb_id = tb->tb_id; 1365 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 1366 1367 if (!frn->err) { 1368 frn->prefixlen = res.prefixlen; 1369 frn->nh_sel = res.nh_sel; 1370 frn->type = res.type; 1371 frn->scope = res.scope; 1372 } 1373 local_bh_enable(); 1374 } 1375 1376 rcu_read_unlock(); 1377} 1378 1379static void nl_fib_input(struct sk_buff *skb) 1380{ 1381 struct net *net; 1382 struct fib_result_nl *frn; 1383 struct nlmsghdr *nlh; 1384 u32 portid; 1385 1386 net = sock_net(skb->sk); 1387 nlh = nlmsg_hdr(skb); 1388 if (skb->len < nlmsg_total_size(sizeof(*frn)) || 1389 skb->len < nlh->nlmsg_len || 1390 nlmsg_len(nlh) < sizeof(*frn)) 1391 return; 1392 1393 skb = netlink_skb_clone(skb, GFP_KERNEL); 1394 if (!skb) 1395 return; 1396 nlh = nlmsg_hdr(skb); 1397 1398 frn = nlmsg_data(nlh); 1399 nl_fib_lookup(net, frn); 1400 1401 portid = NETLINK_CB(skb).portid; /* netlink portid */ 1402 NETLINK_CB(skb).portid = 0; /* from kernel */ 1403 NETLINK_CB(skb).dst_group = 0; /* unicast */ 1404 nlmsg_unicast(net->ipv4.fibnl, skb, portid); 1405} 1406 1407static int __net_init nl_fib_lookup_init(struct net *net) 1408{ 1409 struct sock *sk; 1410 struct netlink_kernel_cfg cfg = { 1411 .input = nl_fib_input, 1412 }; 1413 1414 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg); 1415 if (!sk) 1416 return -EAFNOSUPPORT; 1417 net->ipv4.fibnl = sk; 1418 return 0; 1419} 1420 1421static void nl_fib_lookup_exit(struct net *net) 1422{ 1423 netlink_kernel_release(net->ipv4.fibnl); 1424 net->ipv4.fibnl = NULL; 1425} 1426 1427static void fib_disable_ip(struct net_device *dev, unsigned long event, 1428 bool force) 1429{ 1430 if (fib_sync_down_dev(dev, event, force)) 1431 fib_flush(dev_net(dev)); 1432 else 1433 rt_cache_flush(dev_net(dev)); 1434 arp_ifdown(dev); 1435} 1436 1437static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 1438{ 1439 struct in_ifaddr *ifa = ptr; 1440 struct net_device *dev = ifa->ifa_dev->dev; 1441 struct net *net = dev_net(dev); 1442 1443 switch (event) { 1444 case NETDEV_UP: 1445 fib_add_ifaddr(ifa); 1446#ifdef CONFIG_IP_ROUTE_MULTIPATH 1447 fib_sync_up(dev, RTNH_F_DEAD); 1448#endif 1449 atomic_inc(&net->ipv4.dev_addr_genid); 1450 rt_cache_flush(dev_net(dev)); 1451 break; 1452 case NETDEV_DOWN: 1453 fib_del_ifaddr(ifa, NULL); 1454 atomic_inc(&net->ipv4.dev_addr_genid); 1455 if (!ifa->ifa_dev->ifa_list) { 1456 /* Last address was deleted from this interface. 1457 * Disable IP. 1458 */ 1459 fib_disable_ip(dev, event, true); 1460 } else { 1461 rt_cache_flush(dev_net(dev)); 1462 } 1463 break; 1464 } 1465 return NOTIFY_DONE; 1466} 1467 1468static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1469{ 1470 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1471 struct netdev_notifier_changeupper_info *upper_info = ptr; 1472 struct netdev_notifier_info_ext *info_ext = ptr; 1473 struct in_device *in_dev; 1474 struct net *net = dev_net(dev); 1475 struct in_ifaddr *ifa; 1476 unsigned int flags; 1477 1478 if (event == NETDEV_UNREGISTER) { 1479 fib_disable_ip(dev, event, true); 1480 rt_flush_dev(dev); 1481 return NOTIFY_DONE; 1482 } 1483 1484 in_dev = __in_dev_get_rtnl(dev); 1485 if (!in_dev) 1486 return NOTIFY_DONE; 1487 1488 switch (event) { 1489 case NETDEV_UP: 1490 in_dev_for_each_ifa_rtnl(ifa, in_dev) { 1491 fib_add_ifaddr(ifa); 1492 } 1493#ifdef CONFIG_IP_ROUTE_MULTIPATH 1494 fib_sync_up(dev, RTNH_F_DEAD); 1495#endif 1496 atomic_inc(&net->ipv4.dev_addr_genid); 1497 rt_cache_flush(net); 1498 break; 1499 case NETDEV_DOWN: 1500 fib_disable_ip(dev, event, false); 1501 break; 1502 case NETDEV_CHANGE: 1503 flags = dev_get_flags(dev); 1504 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1505 fib_sync_up(dev, RTNH_F_LINKDOWN); 1506 else 1507 fib_sync_down_dev(dev, event, false); 1508 rt_cache_flush(net); 1509 break; 1510 case NETDEV_CHANGEMTU: 1511 fib_sync_mtu(dev, info_ext->ext.mtu); 1512 rt_cache_flush(net); 1513 break; 1514 case NETDEV_CHANGEUPPER: 1515 upper_info = ptr; 1516 /* flush all routes if dev is linked to or unlinked from 1517 * an L3 master device (e.g., VRF) 1518 */ 1519 if (upper_info->upper_dev && 1520 netif_is_l3_master(upper_info->upper_dev)) 1521 fib_disable_ip(dev, NETDEV_DOWN, true); 1522 break; 1523 } 1524 return NOTIFY_DONE; 1525} 1526 1527static struct notifier_block fib_inetaddr_notifier = { 1528 .notifier_call = fib_inetaddr_event, 1529}; 1530 1531static struct notifier_block fib_netdev_notifier = { 1532 .notifier_call = fib_netdev_event, 1533}; 1534 1535static int __net_init ip_fib_net_init(struct net *net) 1536{ 1537 int err; 1538 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1539 1540 err = fib4_notifier_init(net); 1541 if (err) 1542 return err; 1543 1544#ifdef CONFIG_IP_ROUTE_MULTIPATH 1545 /* Default to 3-tuple */ 1546 net->ipv4.sysctl_fib_multipath_hash_fields = 1547 FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK; 1548#endif 1549 1550 /* Avoid false sharing : Use at least a full cache line */ 1551 size = max_t(size_t, size, L1_CACHE_BYTES); 1552 1553 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1554 if (!net->ipv4.fib_table_hash) { 1555 err = -ENOMEM; 1556 goto err_table_hash_alloc; 1557 } 1558 1559 err = fib4_rules_init(net); 1560 if (err < 0) 1561 goto err_rules_init; 1562 return 0; 1563 1564err_rules_init: 1565 kfree(net->ipv4.fib_table_hash); 1566err_table_hash_alloc: 1567 fib4_notifier_exit(net); 1568 return err; 1569} 1570 1571static void ip_fib_net_exit(struct net *net) 1572{ 1573 int i; 1574 1575 ASSERT_RTNL(); 1576#ifdef CONFIG_IP_MULTIPLE_TABLES 1577 RCU_INIT_POINTER(net->ipv4.fib_main, NULL); 1578 RCU_INIT_POINTER(net->ipv4.fib_default, NULL); 1579#endif 1580 /* Destroy the tables in reverse order to guarantee that the 1581 * local table, ID 255, is destroyed before the main table, ID 1582 * 254. This is necessary as the local table may contain 1583 * references to data contained in the main table. 1584 */ 1585 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) { 1586 struct hlist_head *head = &net->ipv4.fib_table_hash[i]; 1587 struct hlist_node *tmp; 1588 struct fib_table *tb; 1589 1590 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) { 1591 hlist_del(&tb->tb_hlist); 1592 fib_table_flush(net, tb, true); 1593 fib_free_table(tb); 1594 } 1595 } 1596 1597#ifdef CONFIG_IP_MULTIPLE_TABLES 1598 fib4_rules_exit(net); 1599#endif 1600 1601 kfree(net->ipv4.fib_table_hash); 1602 fib4_notifier_exit(net); 1603} 1604 1605static int __net_init fib_net_init(struct net *net) 1606{ 1607 int error; 1608 1609#ifdef CONFIG_IP_ROUTE_CLASSID 1610 atomic_set(&net->ipv4.fib_num_tclassid_users, 0); 1611#endif 1612 error = ip_fib_net_init(net); 1613 if (error < 0) 1614 goto out; 1615 error = nl_fib_lookup_init(net); 1616 if (error < 0) 1617 goto out_nlfl; 1618 error = fib_proc_init(net); 1619 if (error < 0) 1620 goto out_proc; 1621out: 1622 return error; 1623 1624out_proc: 1625 nl_fib_lookup_exit(net); 1626out_nlfl: 1627 rtnl_lock(); 1628 ip_fib_net_exit(net); 1629 rtnl_unlock(); 1630 goto out; 1631} 1632 1633static void __net_exit fib_net_exit(struct net *net) 1634{ 1635 fib_proc_exit(net); 1636 nl_fib_lookup_exit(net); 1637} 1638 1639static void __net_exit fib_net_exit_batch(struct list_head *net_list) 1640{ 1641 struct net *net; 1642 1643 rtnl_lock(); 1644 list_for_each_entry(net, net_list, exit_list) 1645 ip_fib_net_exit(net); 1646 1647 rtnl_unlock(); 1648} 1649 1650static struct pernet_operations fib_net_ops = { 1651 .init = fib_net_init, 1652 .exit = fib_net_exit, 1653 .exit_batch = fib_net_exit_batch, 1654}; 1655 1656void __init ip_fib_init(void) 1657{ 1658 fib_trie_init(); 1659 1660 register_pernet_subsys(&fib_net_ops); 1661 1662 register_netdevice_notifier(&fib_netdev_notifier); 1663 register_inetaddr_notifier(&fib_inetaddr_notifier); 1664 1665 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0); 1666 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0); 1667 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 1668 RTNL_FLAG_DUMP_UNLOCKED); 1669} 1670