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