1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * IPv4 Forwarding Information Base: FIB frontend. 7 * 8 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16 #include <linux/module.h> 17 #include <linux/uaccess.h> 18 #include <linux/bitops.h> 19 #include <linux/capability.h> 20 #include <linux/types.h> 21 #include <linux/kernel.h> 22 #include <linux/mm.h> 23 #include <linux/string.h> 24 #include <linux/socket.h> 25 #include <linux/sockios.h> 26 #include <linux/errno.h> 27 #include <linux/in.h> 28 #include <linux/inet.h> 29 #include <linux/inetdevice.h> 30 #include <linux/netdevice.h> 31 #include <linux/if_addr.h> 32 #include <linux/if_arp.h> 33 #include <linux/skbuff.h> 34 #include <linux/cache.h> 35 #include <linux/init.h> 36 #include <linux/list.h> 37 #include <linux/slab.h> 38 39 #include <net/ip.h> 40 #include <net/protocol.h> 41 #include <net/route.h> 42 #include <net/tcp.h> 43 #include <net/sock.h> 44 #include <net/arp.h> 45 #include <net/ip_fib.h> 46 #include <net/rtnetlink.h> 47 #include <net/xfrm.h> 48 #include <net/l3mdev.h> 49 #include <net/lwtunnel.h> 50 #include <trace/events/fib.h> 51 52 #ifndef CONFIG_IP_MULTIPLE_TABLES 53 54 static int __net_init fib4_rules_init(struct net *net) 55 { 56 struct fib_table *local_table, *main_table; 57 58 main_table = fib_trie_table(RT_TABLE_MAIN, NULL); 59 if (!main_table) 60 return -ENOMEM; 61 62 local_table = fib_trie_table(RT_TABLE_LOCAL, main_table); 63 if (!local_table) 64 goto fail; 65 66 hlist_add_head_rcu(&local_table->tb_hlist, 67 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]); 68 hlist_add_head_rcu(&main_table->tb_hlist, 69 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]); 70 return 0; 71 72 fail: 73 fib_free_table(main_table); 74 return -ENOMEM; 75 } 76 77 static bool fib4_has_custom_rules(struct net *net) 78 { 79 return false; 80 } 81 #else 82 83 struct fib_table *fib_new_table(struct net *net, u32 id) 84 { 85 struct fib_table *tb, *alias = NULL; 86 unsigned int h; 87 88 if (id == 0) 89 id = RT_TABLE_MAIN; 90 tb = fib_get_table(net, id); 91 if (tb) 92 return tb; 93 94 if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules) 95 alias = fib_new_table(net, RT_TABLE_MAIN); 96 97 tb = fib_trie_table(id, alias); 98 if (!tb) 99 return NULL; 100 101 switch (id) { 102 case RT_TABLE_MAIN: 103 rcu_assign_pointer(net->ipv4.fib_main, tb); 104 break; 105 case RT_TABLE_DEFAULT: 106 rcu_assign_pointer(net->ipv4.fib_default, tb); 107 break; 108 default: 109 break; 110 } 111 112 h = id & (FIB_TABLE_HASHSZ - 1); 113 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]); 114 return tb; 115 } 116 EXPORT_SYMBOL_GPL(fib_new_table); 117 118 /* caller must hold either rtnl or rcu read lock */ 119 struct fib_table *fib_get_table(struct net *net, u32 id) 120 { 121 struct fib_table *tb; 122 struct hlist_head *head; 123 unsigned int h; 124 125 if (id == 0) 126 id = RT_TABLE_MAIN; 127 h = id & (FIB_TABLE_HASHSZ - 1); 128 129 head = &net->ipv4.fib_table_hash[h]; 130 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 131 if (tb->tb_id == id) 132 return tb; 133 } 134 return NULL; 135 } 136 137 static bool fib4_has_custom_rules(struct net *net) 138 { 139 return net->ipv4.fib_has_custom_rules; 140 } 141 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 142 143 static void fib_replace_table(struct net *net, struct fib_table *old, 144 struct fib_table *new) 145 { 146 #ifdef CONFIG_IP_MULTIPLE_TABLES 147 switch (new->tb_id) { 148 case RT_TABLE_MAIN: 149 rcu_assign_pointer(net->ipv4.fib_main, new); 150 break; 151 case RT_TABLE_DEFAULT: 152 rcu_assign_pointer(net->ipv4.fib_default, new); 153 break; 154 default: 155 break; 156 } 157 158 #endif 159 /* replace the old table in the hlist */ 160 hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist); 161 } 162 163 int fib_unmerge(struct net *net) 164 { 165 struct fib_table *old, *new, *main_table; 166 167 /* attempt to fetch local table if it has been allocated */ 168 old = fib_get_table(net, RT_TABLE_LOCAL); 169 if (!old) 170 return 0; 171 172 new = fib_trie_unmerge(old); 173 if (!new) 174 return -ENOMEM; 175 176 /* table is already unmerged */ 177 if (new == old) 178 return 0; 179 180 /* replace merged table with clean table */ 181 fib_replace_table(net, old, new); 182 fib_free_table(old); 183 184 /* attempt to fetch main table if it has been allocated */ 185 main_table = fib_get_table(net, RT_TABLE_MAIN); 186 if (!main_table) 187 return 0; 188 189 /* flush local entries from main table */ 190 fib_table_flush_external(main_table); 191 192 return 0; 193 } 194 195 static void fib_flush(struct net *net) 196 { 197 int flushed = 0; 198 unsigned int h; 199 200 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 201 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 202 struct hlist_node *tmp; 203 struct fib_table *tb; 204 205 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) 206 flushed += fib_table_flush(net, tb, false); 207 } 208 209 if (flushed) 210 rt_cache_flush(net); 211 } 212 213 /* 214 * Find address type as if only "dev" was present in the system. If 215 * on_dev is NULL then all interfaces are taken into consideration. 216 */ 217 static inline unsigned int __inet_dev_addr_type(struct net *net, 218 const struct net_device *dev, 219 __be32 addr, u32 tb_id) 220 { 221 struct flowi4 fl4 = { .daddr = addr }; 222 struct fib_result res; 223 unsigned int ret = RTN_BROADCAST; 224 struct fib_table *table; 225 226 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr)) 227 return RTN_BROADCAST; 228 if (ipv4_is_multicast(addr)) 229 return RTN_MULTICAST; 230 231 rcu_read_lock(); 232 233 table = fib_get_table(net, tb_id); 234 if (table) { 235 ret = RTN_UNICAST; 236 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) { 237 if (!dev || dev == res.fi->fib_dev) 238 ret = res.type; 239 } 240 } 241 242 rcu_read_unlock(); 243 return ret; 244 } 245 246 unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id) 247 { 248 return __inet_dev_addr_type(net, NULL, addr, tb_id); 249 } 250 EXPORT_SYMBOL(inet_addr_type_table); 251 252 unsigned int inet_addr_type(struct net *net, __be32 addr) 253 { 254 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL); 255 } 256 EXPORT_SYMBOL(inet_addr_type); 257 258 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, 259 __be32 addr) 260 { 261 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL; 262 263 return __inet_dev_addr_type(net, dev, addr, rt_table); 264 } 265 EXPORT_SYMBOL(inet_dev_addr_type); 266 267 /* inet_addr_type with dev == NULL but using the table from a dev 268 * if one is associated 269 */ 270 unsigned int inet_addr_type_dev_table(struct net *net, 271 const struct net_device *dev, 272 __be32 addr) 273 { 274 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL; 275 276 return __inet_dev_addr_type(net, NULL, addr, rt_table); 277 } 278 EXPORT_SYMBOL(inet_addr_type_dev_table); 279 280 __be32 fib_compute_spec_dst(struct sk_buff *skb) 281 { 282 struct net_device *dev = skb->dev; 283 struct in_device *in_dev; 284 struct fib_result res; 285 struct rtable *rt; 286 struct net *net; 287 int scope; 288 289 rt = skb_rtable(skb); 290 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) == 291 RTCF_LOCAL) 292 return ip_hdr(skb)->daddr; 293 294 in_dev = __in_dev_get_rcu(dev); 295 296 net = dev_net(dev); 297 298 scope = RT_SCOPE_UNIVERSE; 299 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) { 300 bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev); 301 struct flowi4 fl4 = { 302 .flowi4_iif = LOOPBACK_IFINDEX, 303 .flowi4_oif = l3mdev_master_ifindex_rcu(dev), 304 .daddr = ip_hdr(skb)->saddr, 305 .flowi4_tos = RT_TOS(ip_hdr(skb)->tos), 306 .flowi4_scope = scope, 307 .flowi4_mark = vmark ? skb->mark : 0, 308 }; 309 if (!fib_lookup(net, &fl4, &res, 0)) 310 return fib_result_prefsrc(net, &res); 311 } else { 312 scope = RT_SCOPE_LINK; 313 } 314 315 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope); 316 } 317 318 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev) 319 { 320 bool dev_match = false; 321 #ifdef CONFIG_IP_ROUTE_MULTIPATH 322 int ret; 323 324 for (ret = 0; ret < fi->fib_nhs; ret++) { 325 struct fib_nh *nh = &fi->fib_nh[ret]; 326 327 if (nh->fib_nh_dev == dev) { 328 dev_match = true; 329 break; 330 } else if (l3mdev_master_ifindex_rcu(nh->fib_nh_dev) == dev->ifindex) { 331 dev_match = true; 332 break; 333 } 334 } 335 #else 336 if (fi->fib_nh[0].fib_nh_dev == dev) 337 dev_match = true; 338 #endif 339 340 return dev_match; 341 } 342 EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev); 343 344 /* Given (packet source, input interface) and optional (dst, oif, tos): 345 * - (main) check, that source is valid i.e. not broadcast or our local 346 * address. 347 * - figure out what "logical" interface this packet arrived 348 * and calculate "specific destination" address. 349 * - check, that packet arrived from expected physical interface. 350 * called with rcu_read_lock() 351 */ 352 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 353 u8 tos, int oif, struct net_device *dev, 354 int rpf, struct in_device *idev, u32 *itag) 355 { 356 struct net *net = dev_net(dev); 357 struct flow_keys flkeys; 358 int ret, no_addr; 359 struct fib_result res; 360 struct flowi4 fl4; 361 bool dev_match; 362 363 fl4.flowi4_oif = 0; 364 fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev); 365 if (!fl4.flowi4_iif) 366 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX; 367 fl4.daddr = src; 368 fl4.saddr = dst; 369 fl4.flowi4_tos = tos; 370 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 371 fl4.flowi4_tun_key.tun_id = 0; 372 fl4.flowi4_flags = 0; 373 fl4.flowi4_uid = sock_net_uid(net, NULL); 374 375 no_addr = idev->ifa_list == NULL; 376 377 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0; 378 if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) { 379 fl4.flowi4_proto = 0; 380 fl4.fl4_sport = 0; 381 fl4.fl4_dport = 0; 382 } 383 384 if (fib_lookup(net, &fl4, &res, 0)) 385 goto last_resort; 386 if (res.type != RTN_UNICAST && 387 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev))) 388 goto e_inval; 389 fib_combine_itag(itag, &res); 390 391 dev_match = fib_info_nh_uses_dev(res.fi, dev); 392 if (dev_match) { 393 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; 394 return ret; 395 } 396 if (no_addr) 397 goto last_resort; 398 if (rpf == 1) 399 goto e_rpf; 400 fl4.flowi4_oif = dev->ifindex; 401 402 ret = 0; 403 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) { 404 if (res.type == RTN_UNICAST) 405 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; 406 } 407 return ret; 408 409 last_resort: 410 if (rpf) 411 goto e_rpf; 412 *itag = 0; 413 return 0; 414 415 e_inval: 416 return -EINVAL; 417 e_rpf: 418 return -EXDEV; 419 } 420 421 /* Ignore rp_filter for packets protected by IPsec. */ 422 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 423 u8 tos, int oif, struct net_device *dev, 424 struct in_device *idev, u32 *itag) 425 { 426 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev); 427 struct net *net = dev_net(dev); 428 429 if (!r && !fib_num_tclassid_users(net) && 430 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) { 431 if (IN_DEV_ACCEPT_LOCAL(idev)) 432 goto ok; 433 /* with custom local routes in place, checking local addresses 434 * only will be too optimistic, with custom rules, checking 435 * local addresses only can be too strict, e.g. due to vrf 436 */ 437 if (net->ipv4.fib_has_custom_local_routes || 438 fib4_has_custom_rules(net)) 439 goto full_check; 440 if (inet_lookup_ifaddr_rcu(net, src)) 441 return -EINVAL; 442 443 ok: 444 *itag = 0; 445 return 0; 446 } 447 448 full_check: 449 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag); 450 } 451 452 static inline __be32 sk_extract_addr(struct sockaddr *addr) 453 { 454 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 455 } 456 457 static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 458 { 459 struct nlattr *nla; 460 461 nla = (struct nlattr *) ((char *) mx + len); 462 nla->nla_type = type; 463 nla->nla_len = nla_attr_size(4); 464 *(u32 *) nla_data(nla) = value; 465 466 return len + nla_total_size(4); 467 } 468 469 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 470 struct fib_config *cfg) 471 { 472 __be32 addr; 473 int plen; 474 475 memset(cfg, 0, sizeof(*cfg)); 476 cfg->fc_nlinfo.nl_net = net; 477 478 if (rt->rt_dst.sa_family != AF_INET) 479 return -EAFNOSUPPORT; 480 481 /* 482 * Check mask for validity: 483 * a) it must be contiguous. 484 * b) destination must have all host bits clear. 485 * c) if application forgot to set correct family (AF_INET), 486 * reject request unless it is absolutely clear i.e. 487 * both family and mask are zero. 488 */ 489 plen = 32; 490 addr = sk_extract_addr(&rt->rt_dst); 491 if (!(rt->rt_flags & RTF_HOST)) { 492 __be32 mask = sk_extract_addr(&rt->rt_genmask); 493 494 if (rt->rt_genmask.sa_family != AF_INET) { 495 if (mask || rt->rt_genmask.sa_family) 496 return -EAFNOSUPPORT; 497 } 498 499 if (bad_mask(mask, addr)) 500 return -EINVAL; 501 502 plen = inet_mask_len(mask); 503 } 504 505 cfg->fc_dst_len = plen; 506 cfg->fc_dst = addr; 507 508 if (cmd != SIOCDELRT) { 509 cfg->fc_nlflags = NLM_F_CREATE; 510 cfg->fc_protocol = RTPROT_BOOT; 511 } 512 513 if (rt->rt_metric) 514 cfg->fc_priority = rt->rt_metric - 1; 515 516 if (rt->rt_flags & RTF_REJECT) { 517 cfg->fc_scope = RT_SCOPE_HOST; 518 cfg->fc_type = RTN_UNREACHABLE; 519 return 0; 520 } 521 522 cfg->fc_scope = RT_SCOPE_NOWHERE; 523 cfg->fc_type = RTN_UNICAST; 524 525 if (rt->rt_dev) { 526 char *colon; 527 struct net_device *dev; 528 char devname[IFNAMSIZ]; 529 530 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 531 return -EFAULT; 532 533 devname[IFNAMSIZ-1] = 0; 534 colon = strchr(devname, ':'); 535 if (colon) 536 *colon = 0; 537 dev = __dev_get_by_name(net, devname); 538 if (!dev) 539 return -ENODEV; 540 cfg->fc_oif = dev->ifindex; 541 cfg->fc_table = l3mdev_fib_table(dev); 542 if (colon) { 543 struct in_ifaddr *ifa; 544 struct in_device *in_dev = __in_dev_get_rtnl(dev); 545 if (!in_dev) 546 return -ENODEV; 547 *colon = ':'; 548 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) 549 if (strcmp(ifa->ifa_label, devname) == 0) 550 break; 551 if (!ifa) 552 return -ENODEV; 553 cfg->fc_prefsrc = ifa->ifa_local; 554 } 555 } 556 557 addr = sk_extract_addr(&rt->rt_gateway); 558 if (rt->rt_gateway.sa_family == AF_INET && addr) { 559 unsigned int addr_type; 560 561 cfg->fc_gw4 = addr; 562 cfg->fc_gw_family = AF_INET; 563 addr_type = inet_addr_type_table(net, addr, cfg->fc_table); 564 if (rt->rt_flags & RTF_GATEWAY && 565 addr_type == RTN_UNICAST) 566 cfg->fc_scope = RT_SCOPE_UNIVERSE; 567 } 568 569 if (cmd == SIOCDELRT) 570 return 0; 571 572 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family) 573 return -EINVAL; 574 575 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 576 cfg->fc_scope = RT_SCOPE_LINK; 577 578 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 579 struct nlattr *mx; 580 int len = 0; 581 582 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL); 583 if (!mx) 584 return -ENOMEM; 585 586 if (rt->rt_flags & RTF_MTU) 587 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 588 589 if (rt->rt_flags & RTF_WINDOW) 590 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 591 592 if (rt->rt_flags & RTF_IRTT) 593 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 594 595 cfg->fc_mx = mx; 596 cfg->fc_mx_len = len; 597 } 598 599 return 0; 600 } 601 602 /* 603 * Handle IP routing ioctl calls. 604 * These are used to manipulate the routing tables 605 */ 606 int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt) 607 { 608 struct fib_config cfg; 609 int err; 610 611 switch (cmd) { 612 case SIOCADDRT: /* Add a route */ 613 case SIOCDELRT: /* Delete a route */ 614 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 615 return -EPERM; 616 617 rtnl_lock(); 618 err = rtentry_to_fib_config(net, cmd, rt, &cfg); 619 if (err == 0) { 620 struct fib_table *tb; 621 622 if (cmd == SIOCDELRT) { 623 tb = fib_get_table(net, cfg.fc_table); 624 if (tb) 625 err = fib_table_delete(net, tb, &cfg, 626 NULL); 627 else 628 err = -ESRCH; 629 } else { 630 tb = fib_new_table(net, cfg.fc_table); 631 if (tb) 632 err = fib_table_insert(net, tb, 633 &cfg, NULL); 634 else 635 err = -ENOBUFS; 636 } 637 638 /* allocated by rtentry_to_fib_config() */ 639 kfree(cfg.fc_mx); 640 } 641 rtnl_unlock(); 642 return err; 643 } 644 return -EINVAL; 645 } 646 647 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 648 [RTA_DST] = { .type = NLA_U32 }, 649 [RTA_SRC] = { .type = NLA_U32 }, 650 [RTA_IIF] = { .type = NLA_U32 }, 651 [RTA_OIF] = { .type = NLA_U32 }, 652 [RTA_GATEWAY] = { .type = NLA_U32 }, 653 [RTA_PRIORITY] = { .type = NLA_U32 }, 654 [RTA_PREFSRC] = { .type = NLA_U32 }, 655 [RTA_METRICS] = { .type = NLA_NESTED }, 656 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 657 [RTA_FLOW] = { .type = NLA_U32 }, 658 [RTA_ENCAP_TYPE] = { .type = NLA_U16 }, 659 [RTA_ENCAP] = { .type = NLA_NESTED }, 660 [RTA_UID] = { .type = NLA_U32 }, 661 [RTA_MARK] = { .type = NLA_U32 }, 662 [RTA_TABLE] = { .type = NLA_U32 }, 663 [RTA_IP_PROTO] = { .type = NLA_U8 }, 664 [RTA_SPORT] = { .type = NLA_U16 }, 665 [RTA_DPORT] = { .type = NLA_U16 }, 666 }; 667 668 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, 669 struct netlink_ext_ack *extack) 670 { 671 struct rtvia *via; 672 int alen; 673 674 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) { 675 NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA"); 676 return -EINVAL; 677 } 678 679 via = nla_data(nla); 680 alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr); 681 682 switch (via->rtvia_family) { 683 case AF_INET: 684 if (alen != sizeof(__be32)) { 685 NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA"); 686 return -EINVAL; 687 } 688 cfg->fc_gw_family = AF_INET; 689 cfg->fc_gw4 = *((__be32 *)via->rtvia_addr); 690 break; 691 case AF_INET6: 692 #ifdef CONFIG_IPV6 693 if (alen != sizeof(struct in6_addr)) { 694 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA"); 695 return -EINVAL; 696 } 697 cfg->fc_gw_family = AF_INET6; 698 cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr); 699 #else 700 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel"); 701 return -EINVAL; 702 #endif 703 break; 704 default: 705 NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA"); 706 return -EINVAL; 707 } 708 709 return 0; 710 } 711 712 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 713 struct nlmsghdr *nlh, struct fib_config *cfg, 714 struct netlink_ext_ack *extack) 715 { 716 bool has_gw = false, has_via = false; 717 struct nlattr *attr; 718 int err, remaining; 719 struct rtmsg *rtm; 720 721 err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX, 722 rtm_ipv4_policy, extack); 723 if (err < 0) 724 goto errout; 725 726 memset(cfg, 0, sizeof(*cfg)); 727 728 rtm = nlmsg_data(nlh); 729 cfg->fc_dst_len = rtm->rtm_dst_len; 730 cfg->fc_tos = rtm->rtm_tos; 731 cfg->fc_table = rtm->rtm_table; 732 cfg->fc_protocol = rtm->rtm_protocol; 733 cfg->fc_scope = rtm->rtm_scope; 734 cfg->fc_type = rtm->rtm_type; 735 cfg->fc_flags = rtm->rtm_flags; 736 cfg->fc_nlflags = nlh->nlmsg_flags; 737 738 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid; 739 cfg->fc_nlinfo.nlh = nlh; 740 cfg->fc_nlinfo.nl_net = net; 741 742 if (cfg->fc_type > RTN_MAX) { 743 NL_SET_ERR_MSG(extack, "Invalid route type"); 744 err = -EINVAL; 745 goto errout; 746 } 747 748 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 749 switch (nla_type(attr)) { 750 case RTA_DST: 751 cfg->fc_dst = nla_get_be32(attr); 752 break; 753 case RTA_OIF: 754 cfg->fc_oif = nla_get_u32(attr); 755 break; 756 case RTA_GATEWAY: 757 has_gw = true; 758 cfg->fc_gw4 = nla_get_be32(attr); 759 if (cfg->fc_gw4) 760 cfg->fc_gw_family = AF_INET; 761 break; 762 case RTA_VIA: 763 has_via = true; 764 err = fib_gw_from_via(cfg, attr, extack); 765 if (err) 766 goto errout; 767 break; 768 case RTA_PRIORITY: 769 cfg->fc_priority = nla_get_u32(attr); 770 break; 771 case RTA_PREFSRC: 772 cfg->fc_prefsrc = nla_get_be32(attr); 773 break; 774 case RTA_METRICS: 775 cfg->fc_mx = nla_data(attr); 776 cfg->fc_mx_len = nla_len(attr); 777 break; 778 case RTA_MULTIPATH: 779 err = lwtunnel_valid_encap_type_attr(nla_data(attr), 780 nla_len(attr), 781 extack); 782 if (err < 0) 783 goto errout; 784 cfg->fc_mp = nla_data(attr); 785 cfg->fc_mp_len = nla_len(attr); 786 break; 787 case RTA_FLOW: 788 cfg->fc_flow = nla_get_u32(attr); 789 break; 790 case RTA_TABLE: 791 cfg->fc_table = nla_get_u32(attr); 792 break; 793 case RTA_ENCAP: 794 cfg->fc_encap = attr; 795 break; 796 case RTA_ENCAP_TYPE: 797 cfg->fc_encap_type = nla_get_u16(attr); 798 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, 799 extack); 800 if (err < 0) 801 goto errout; 802 break; 803 } 804 } 805 806 if (has_gw && has_via) { 807 NL_SET_ERR_MSG(extack, 808 "Nexthop configuration can not contain both GATEWAY and VIA"); 809 goto errout; 810 } 811 812 return 0; 813 errout: 814 return err; 815 } 816 817 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, 818 struct netlink_ext_ack *extack) 819 { 820 struct net *net = sock_net(skb->sk); 821 struct fib_config cfg; 822 struct fib_table *tb; 823 int err; 824 825 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 826 if (err < 0) 827 goto errout; 828 829 tb = fib_get_table(net, cfg.fc_table); 830 if (!tb) { 831 NL_SET_ERR_MSG(extack, "FIB table does not exist"); 832 err = -ESRCH; 833 goto errout; 834 } 835 836 err = fib_table_delete(net, tb, &cfg, extack); 837 errout: 838 return err; 839 } 840 841 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, 842 struct netlink_ext_ack *extack) 843 { 844 struct net *net = sock_net(skb->sk); 845 struct fib_config cfg; 846 struct fib_table *tb; 847 int err; 848 849 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 850 if (err < 0) 851 goto errout; 852 853 tb = fib_new_table(net, cfg.fc_table); 854 if (!tb) { 855 err = -ENOBUFS; 856 goto errout; 857 } 858 859 err = fib_table_insert(net, tb, &cfg, extack); 860 if (!err && cfg.fc_type == RTN_LOCAL) 861 net->ipv4.fib_has_custom_local_routes = true; 862 errout: 863 return err; 864 } 865 866 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 867 struct fib_dump_filter *filter, 868 struct netlink_callback *cb) 869 { 870 struct netlink_ext_ack *extack = cb->extack; 871 struct nlattr *tb[RTA_MAX + 1]; 872 struct rtmsg *rtm; 873 int err, i; 874 875 ASSERT_RTNL(); 876 877 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 878 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request"); 879 return -EINVAL; 880 } 881 882 rtm = nlmsg_data(nlh); 883 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos || 884 rtm->rtm_scope) { 885 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request"); 886 return -EINVAL; 887 } 888 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) { 889 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request"); 890 return -EINVAL; 891 } 892 893 filter->dump_all_families = (rtm->rtm_family == AF_UNSPEC); 894 filter->flags = rtm->rtm_flags; 895 filter->protocol = rtm->rtm_protocol; 896 filter->rt_type = rtm->rtm_type; 897 filter->table_id = rtm->rtm_table; 898 899 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 900 rtm_ipv4_policy, extack); 901 if (err < 0) 902 return err; 903 904 for (i = 0; i <= RTA_MAX; ++i) { 905 int ifindex; 906 907 if (!tb[i]) 908 continue; 909 910 switch (i) { 911 case RTA_TABLE: 912 filter->table_id = nla_get_u32(tb[i]); 913 break; 914 case RTA_OIF: 915 ifindex = nla_get_u32(tb[i]); 916 filter->dev = __dev_get_by_index(net, ifindex); 917 if (!filter->dev) 918 return -ENODEV; 919 break; 920 default: 921 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request"); 922 return -EINVAL; 923 } 924 } 925 926 if (filter->flags || filter->protocol || filter->rt_type || 927 filter->table_id || filter->dev) { 928 filter->filter_set = 1; 929 cb->answer_flags = NLM_F_DUMP_FILTERED; 930 } 931 932 return 0; 933 } 934 EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req); 935 936 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 937 { 938 const struct nlmsghdr *nlh = cb->nlh; 939 struct net *net = sock_net(skb->sk); 940 struct fib_dump_filter filter = {}; 941 unsigned int h, s_h; 942 unsigned int e = 0, s_e; 943 struct fib_table *tb; 944 struct hlist_head *head; 945 int dumped = 0, err; 946 947 if (cb->strict_check) { 948 err = ip_valid_fib_dump_req(net, nlh, &filter, cb); 949 if (err < 0) 950 return err; 951 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 952 struct rtmsg *rtm = nlmsg_data(nlh); 953 954 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED); 955 } 956 957 /* fib entries are never clones and ipv4 does not use prefix flag */ 958 if (filter.flags & (RTM_F_PREFIX | RTM_F_CLONED)) 959 return skb->len; 960 961 if (filter.table_id) { 962 tb = fib_get_table(net, filter.table_id); 963 if (!tb) { 964 if (filter.dump_all_families) 965 return skb->len; 966 967 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist"); 968 return -ENOENT; 969 } 970 971 err = fib_table_dump(tb, skb, cb, &filter); 972 return skb->len ? : err; 973 } 974 975 s_h = cb->args[0]; 976 s_e = cb->args[1]; 977 978 rcu_read_lock(); 979 980 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 981 e = 0; 982 head = &net->ipv4.fib_table_hash[h]; 983 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 984 if (e < s_e) 985 goto next; 986 if (dumped) 987 memset(&cb->args[2], 0, sizeof(cb->args) - 988 2 * sizeof(cb->args[0])); 989 err = fib_table_dump(tb, skb, cb, &filter); 990 if (err < 0) { 991 if (likely(skb->len)) 992 goto out; 993 994 goto out_err; 995 } 996 dumped = 1; 997 next: 998 e++; 999 } 1000 } 1001 out: 1002 err = skb->len; 1003 out_err: 1004 rcu_read_unlock(); 1005 1006 cb->args[1] = e; 1007 cb->args[0] = h; 1008 1009 return err; 1010 } 1011 1012 /* Prepare and feed intra-kernel routing request. 1013 * Really, it should be netlink message, but :-( netlink 1014 * can be not configured, so that we feed it directly 1015 * to fib engine. It is legal, because all events occur 1016 * only when netlink is already locked. 1017 */ 1018 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, 1019 struct in_ifaddr *ifa, u32 rt_priority) 1020 { 1021 struct net *net = dev_net(ifa->ifa_dev->dev); 1022 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev); 1023 struct fib_table *tb; 1024 struct fib_config cfg = { 1025 .fc_protocol = RTPROT_KERNEL, 1026 .fc_type = type, 1027 .fc_dst = dst, 1028 .fc_dst_len = dst_len, 1029 .fc_priority = rt_priority, 1030 .fc_prefsrc = ifa->ifa_local, 1031 .fc_oif = ifa->ifa_dev->dev->ifindex, 1032 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 1033 .fc_nlinfo = { 1034 .nl_net = net, 1035 }, 1036 }; 1037 1038 if (!tb_id) 1039 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL; 1040 1041 tb = fib_new_table(net, tb_id); 1042 if (!tb) 1043 return; 1044 1045 cfg.fc_table = tb->tb_id; 1046 1047 if (type != RTN_LOCAL) 1048 cfg.fc_scope = RT_SCOPE_LINK; 1049 else 1050 cfg.fc_scope = RT_SCOPE_HOST; 1051 1052 if (cmd == RTM_NEWROUTE) 1053 fib_table_insert(net, tb, &cfg, NULL); 1054 else 1055 fib_table_delete(net, tb, &cfg, NULL); 1056 } 1057 1058 void fib_add_ifaddr(struct in_ifaddr *ifa) 1059 { 1060 struct in_device *in_dev = ifa->ifa_dev; 1061 struct net_device *dev = in_dev->dev; 1062 struct in_ifaddr *prim = ifa; 1063 __be32 mask = ifa->ifa_mask; 1064 __be32 addr = ifa->ifa_local; 1065 __be32 prefix = ifa->ifa_address & mask; 1066 1067 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1068 prim = inet_ifa_byprefix(in_dev, prefix, mask); 1069 if (!prim) { 1070 pr_warn("%s: bug: prim == NULL\n", __func__); 1071 return; 1072 } 1073 } 1074 1075 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0); 1076 1077 if (!(dev->flags & IFF_UP)) 1078 return; 1079 1080 /* Add broadcast address, if it is explicitly assigned. */ 1081 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 1082 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1083 prim, 0); 1084 1085 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 1086 (prefix != addr || ifa->ifa_prefixlen < 32)) { 1087 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1088 fib_magic(RTM_NEWROUTE, 1089 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1090 prefix, ifa->ifa_prefixlen, prim, 1091 ifa->ifa_rt_priority); 1092 1093 /* Add network specific broadcasts, when it takes a sense */ 1094 if (ifa->ifa_prefixlen < 31) { 1095 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, 1096 prim, 0); 1097 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 1098 32, prim, 0); 1099 } 1100 } 1101 } 1102 1103 void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric) 1104 { 1105 __be32 prefix = ifa->ifa_address & ifa->ifa_mask; 1106 struct in_device *in_dev = ifa->ifa_dev; 1107 struct net_device *dev = in_dev->dev; 1108 1109 if (!(dev->flags & IFF_UP) || 1110 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) || 1111 ipv4_is_zeronet(prefix) || 1112 prefix == ifa->ifa_local || ifa->ifa_prefixlen == 32) 1113 return; 1114 1115 /* add the new */ 1116 fib_magic(RTM_NEWROUTE, 1117 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1118 prefix, ifa->ifa_prefixlen, ifa, new_metric); 1119 1120 /* delete the old */ 1121 fib_magic(RTM_DELROUTE, 1122 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1123 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority); 1124 } 1125 1126 /* Delete primary or secondary address. 1127 * Optionally, on secondary address promotion consider the addresses 1128 * from subnet iprim as deleted, even if they are in device list. 1129 * In this case the secondary ifa can be in device list. 1130 */ 1131 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 1132 { 1133 struct in_device *in_dev = ifa->ifa_dev; 1134 struct net_device *dev = in_dev->dev; 1135 struct in_ifaddr *ifa1; 1136 struct in_ifaddr *prim = ifa, *prim1 = NULL; 1137 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 1138 __be32 any = ifa->ifa_address & ifa->ifa_mask; 1139 #define LOCAL_OK 1 1140 #define BRD_OK 2 1141 #define BRD0_OK 4 1142 #define BRD1_OK 8 1143 unsigned int ok = 0; 1144 int subnet = 0; /* Primary network */ 1145 int gone = 1; /* Address is missing */ 1146 int same_prefsrc = 0; /* Another primary with same IP */ 1147 1148 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1149 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 1150 if (!prim) { 1151 /* if the device has been deleted, we don't perform 1152 * address promotion 1153 */ 1154 if (!in_dev->dead) 1155 pr_warn("%s: bug: prim == NULL\n", __func__); 1156 return; 1157 } 1158 if (iprim && iprim != prim) { 1159 pr_warn("%s: bug: iprim != prim\n", __func__); 1160 return; 1161 } 1162 } else if (!ipv4_is_zeronet(any) && 1163 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 1164 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1165 fib_magic(RTM_DELROUTE, 1166 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1167 any, ifa->ifa_prefixlen, prim, 0); 1168 subnet = 1; 1169 } 1170 1171 if (in_dev->dead) 1172 goto no_promotions; 1173 1174 /* Deletion is more complicated than add. 1175 * We should take care of not to delete too much :-) 1176 * 1177 * Scan address list to be sure that addresses are really gone. 1178 */ 1179 1180 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) { 1181 if (ifa1 == ifa) { 1182 /* promotion, keep the IP */ 1183 gone = 0; 1184 continue; 1185 } 1186 /* Ignore IFAs from our subnet */ 1187 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 1188 inet_ifa_match(ifa1->ifa_address, iprim)) 1189 continue; 1190 1191 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 1192 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 1193 /* Another address from our subnet? */ 1194 if (ifa1->ifa_mask == prim->ifa_mask && 1195 inet_ifa_match(ifa1->ifa_address, prim)) 1196 prim1 = prim; 1197 else { 1198 /* We reached the secondaries, so 1199 * same_prefsrc should be determined. 1200 */ 1201 if (!same_prefsrc) 1202 continue; 1203 /* Search new prim1 if ifa1 is not 1204 * using the current prim1 1205 */ 1206 if (!prim1 || 1207 ifa1->ifa_mask != prim1->ifa_mask || 1208 !inet_ifa_match(ifa1->ifa_address, prim1)) 1209 prim1 = inet_ifa_byprefix(in_dev, 1210 ifa1->ifa_address, 1211 ifa1->ifa_mask); 1212 if (!prim1) 1213 continue; 1214 if (prim1->ifa_local != prim->ifa_local) 1215 continue; 1216 } 1217 } else { 1218 if (prim->ifa_local != ifa1->ifa_local) 1219 continue; 1220 prim1 = ifa1; 1221 if (prim != prim1) 1222 same_prefsrc = 1; 1223 } 1224 if (ifa->ifa_local == ifa1->ifa_local) 1225 ok |= LOCAL_OK; 1226 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 1227 ok |= BRD_OK; 1228 if (brd == ifa1->ifa_broadcast) 1229 ok |= BRD1_OK; 1230 if (any == ifa1->ifa_broadcast) 1231 ok |= BRD0_OK; 1232 /* primary has network specific broadcasts */ 1233 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 1234 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 1235 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 1236 1237 if (!ipv4_is_zeronet(any1)) { 1238 if (ifa->ifa_broadcast == brd1 || 1239 ifa->ifa_broadcast == any1) 1240 ok |= BRD_OK; 1241 if (brd == brd1 || brd == any1) 1242 ok |= BRD1_OK; 1243 if (any == brd1 || any == any1) 1244 ok |= BRD0_OK; 1245 } 1246 } 1247 } 1248 1249 no_promotions: 1250 if (!(ok & BRD_OK)) 1251 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1252 prim, 0); 1253 if (subnet && ifa->ifa_prefixlen < 31) { 1254 if (!(ok & BRD1_OK)) 1255 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, 1256 prim, 0); 1257 if (!(ok & BRD0_OK)) 1258 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, 1259 prim, 0); 1260 } 1261 if (!(ok & LOCAL_OK)) { 1262 unsigned int addr_type; 1263 1264 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0); 1265 1266 /* Check, that this local address finally disappeared. */ 1267 addr_type = inet_addr_type_dev_table(dev_net(dev), dev, 1268 ifa->ifa_local); 1269 if (gone && addr_type != RTN_LOCAL) { 1270 /* And the last, but not the least thing. 1271 * We must flush stray FIB entries. 1272 * 1273 * First of all, we scan fib_info list searching 1274 * for stray nexthop entries, then ignite fib_flush. 1275 */ 1276 if (fib_sync_down_addr(dev, ifa->ifa_local)) 1277 fib_flush(dev_net(dev)); 1278 } 1279 } 1280 #undef LOCAL_OK 1281 #undef BRD_OK 1282 #undef BRD0_OK 1283 #undef BRD1_OK 1284 } 1285 1286 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn) 1287 { 1288 1289 struct fib_result res; 1290 struct flowi4 fl4 = { 1291 .flowi4_mark = frn->fl_mark, 1292 .daddr = frn->fl_addr, 1293 .flowi4_tos = frn->fl_tos, 1294 .flowi4_scope = frn->fl_scope, 1295 }; 1296 struct fib_table *tb; 1297 1298 rcu_read_lock(); 1299 1300 tb = fib_get_table(net, frn->tb_id_in); 1301 1302 frn->err = -ENOENT; 1303 if (tb) { 1304 local_bh_disable(); 1305 1306 frn->tb_id = tb->tb_id; 1307 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 1308 1309 if (!frn->err) { 1310 frn->prefixlen = res.prefixlen; 1311 frn->nh_sel = res.nh_sel; 1312 frn->type = res.type; 1313 frn->scope = res.scope; 1314 } 1315 local_bh_enable(); 1316 } 1317 1318 rcu_read_unlock(); 1319 } 1320 1321 static void nl_fib_input(struct sk_buff *skb) 1322 { 1323 struct net *net; 1324 struct fib_result_nl *frn; 1325 struct nlmsghdr *nlh; 1326 u32 portid; 1327 1328 net = sock_net(skb->sk); 1329 nlh = nlmsg_hdr(skb); 1330 if (skb->len < nlmsg_total_size(sizeof(*frn)) || 1331 skb->len < nlh->nlmsg_len || 1332 nlmsg_len(nlh) < sizeof(*frn)) 1333 return; 1334 1335 skb = netlink_skb_clone(skb, GFP_KERNEL); 1336 if (!skb) 1337 return; 1338 nlh = nlmsg_hdr(skb); 1339 1340 frn = (struct fib_result_nl *) nlmsg_data(nlh); 1341 nl_fib_lookup(net, frn); 1342 1343 portid = NETLINK_CB(skb).portid; /* netlink portid */ 1344 NETLINK_CB(skb).portid = 0; /* from kernel */ 1345 NETLINK_CB(skb).dst_group = 0; /* unicast */ 1346 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT); 1347 } 1348 1349 static int __net_init nl_fib_lookup_init(struct net *net) 1350 { 1351 struct sock *sk; 1352 struct netlink_kernel_cfg cfg = { 1353 .input = nl_fib_input, 1354 }; 1355 1356 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg); 1357 if (!sk) 1358 return -EAFNOSUPPORT; 1359 net->ipv4.fibnl = sk; 1360 return 0; 1361 } 1362 1363 static void nl_fib_lookup_exit(struct net *net) 1364 { 1365 netlink_kernel_release(net->ipv4.fibnl); 1366 net->ipv4.fibnl = NULL; 1367 } 1368 1369 static void fib_disable_ip(struct net_device *dev, unsigned long event, 1370 bool force) 1371 { 1372 if (fib_sync_down_dev(dev, event, force)) 1373 fib_flush(dev_net(dev)); 1374 else 1375 rt_cache_flush(dev_net(dev)); 1376 arp_ifdown(dev); 1377 } 1378 1379 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 1380 { 1381 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 1382 struct net_device *dev = ifa->ifa_dev->dev; 1383 struct net *net = dev_net(dev); 1384 1385 switch (event) { 1386 case NETDEV_UP: 1387 fib_add_ifaddr(ifa); 1388 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1389 fib_sync_up(dev, RTNH_F_DEAD); 1390 #endif 1391 atomic_inc(&net->ipv4.dev_addr_genid); 1392 rt_cache_flush(dev_net(dev)); 1393 break; 1394 case NETDEV_DOWN: 1395 fib_del_ifaddr(ifa, NULL); 1396 atomic_inc(&net->ipv4.dev_addr_genid); 1397 if (!ifa->ifa_dev->ifa_list) { 1398 /* Last address was deleted from this interface. 1399 * Disable IP. 1400 */ 1401 fib_disable_ip(dev, event, true); 1402 } else { 1403 rt_cache_flush(dev_net(dev)); 1404 } 1405 break; 1406 } 1407 return NOTIFY_DONE; 1408 } 1409 1410 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1411 { 1412 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1413 struct netdev_notifier_changeupper_info *upper_info = ptr; 1414 struct netdev_notifier_info_ext *info_ext = ptr; 1415 struct in_device *in_dev; 1416 struct net *net = dev_net(dev); 1417 unsigned int flags; 1418 1419 if (event == NETDEV_UNREGISTER) { 1420 fib_disable_ip(dev, event, true); 1421 rt_flush_dev(dev); 1422 return NOTIFY_DONE; 1423 } 1424 1425 in_dev = __in_dev_get_rtnl(dev); 1426 if (!in_dev) 1427 return NOTIFY_DONE; 1428 1429 switch (event) { 1430 case NETDEV_UP: 1431 for_ifa(in_dev) { 1432 fib_add_ifaddr(ifa); 1433 } endfor_ifa(in_dev); 1434 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1435 fib_sync_up(dev, RTNH_F_DEAD); 1436 #endif 1437 atomic_inc(&net->ipv4.dev_addr_genid); 1438 rt_cache_flush(net); 1439 break; 1440 case NETDEV_DOWN: 1441 fib_disable_ip(dev, event, false); 1442 break; 1443 case NETDEV_CHANGE: 1444 flags = dev_get_flags(dev); 1445 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1446 fib_sync_up(dev, RTNH_F_LINKDOWN); 1447 else 1448 fib_sync_down_dev(dev, event, false); 1449 rt_cache_flush(net); 1450 break; 1451 case NETDEV_CHANGEMTU: 1452 fib_sync_mtu(dev, info_ext->ext.mtu); 1453 rt_cache_flush(net); 1454 break; 1455 case NETDEV_CHANGEUPPER: 1456 upper_info = ptr; 1457 /* flush all routes if dev is linked to or unlinked from 1458 * an L3 master device (e.g., VRF) 1459 */ 1460 if (upper_info->upper_dev && 1461 netif_is_l3_master(upper_info->upper_dev)) 1462 fib_disable_ip(dev, NETDEV_DOWN, true); 1463 break; 1464 } 1465 return NOTIFY_DONE; 1466 } 1467 1468 static struct notifier_block fib_inetaddr_notifier = { 1469 .notifier_call = fib_inetaddr_event, 1470 }; 1471 1472 static struct notifier_block fib_netdev_notifier = { 1473 .notifier_call = fib_netdev_event, 1474 }; 1475 1476 static int __net_init ip_fib_net_init(struct net *net) 1477 { 1478 int err; 1479 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1480 1481 err = fib4_notifier_init(net); 1482 if (err) 1483 return err; 1484 1485 /* Avoid false sharing : Use at least a full cache line */ 1486 size = max_t(size_t, size, L1_CACHE_BYTES); 1487 1488 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1489 if (!net->ipv4.fib_table_hash) { 1490 err = -ENOMEM; 1491 goto err_table_hash_alloc; 1492 } 1493 1494 err = fib4_rules_init(net); 1495 if (err < 0) 1496 goto err_rules_init; 1497 return 0; 1498 1499 err_rules_init: 1500 kfree(net->ipv4.fib_table_hash); 1501 err_table_hash_alloc: 1502 fib4_notifier_exit(net); 1503 return err; 1504 } 1505 1506 static void ip_fib_net_exit(struct net *net) 1507 { 1508 int i; 1509 1510 rtnl_lock(); 1511 #ifdef CONFIG_IP_MULTIPLE_TABLES 1512 RCU_INIT_POINTER(net->ipv4.fib_main, NULL); 1513 RCU_INIT_POINTER(net->ipv4.fib_default, NULL); 1514 #endif 1515 /* Destroy the tables in reverse order to guarantee that the 1516 * local table, ID 255, is destroyed before the main table, ID 1517 * 254. This is necessary as the local table may contain 1518 * references to data contained in the main table. 1519 */ 1520 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) { 1521 struct hlist_head *head = &net->ipv4.fib_table_hash[i]; 1522 struct hlist_node *tmp; 1523 struct fib_table *tb; 1524 1525 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) { 1526 hlist_del(&tb->tb_hlist); 1527 fib_table_flush(net, tb, true); 1528 fib_free_table(tb); 1529 } 1530 } 1531 1532 #ifdef CONFIG_IP_MULTIPLE_TABLES 1533 fib4_rules_exit(net); 1534 #endif 1535 rtnl_unlock(); 1536 kfree(net->ipv4.fib_table_hash); 1537 fib4_notifier_exit(net); 1538 } 1539 1540 static int __net_init fib_net_init(struct net *net) 1541 { 1542 int error; 1543 1544 #ifdef CONFIG_IP_ROUTE_CLASSID 1545 net->ipv4.fib_num_tclassid_users = 0; 1546 #endif 1547 error = ip_fib_net_init(net); 1548 if (error < 0) 1549 goto out; 1550 error = nl_fib_lookup_init(net); 1551 if (error < 0) 1552 goto out_nlfl; 1553 error = fib_proc_init(net); 1554 if (error < 0) 1555 goto out_proc; 1556 out: 1557 return error; 1558 1559 out_proc: 1560 nl_fib_lookup_exit(net); 1561 out_nlfl: 1562 ip_fib_net_exit(net); 1563 goto out; 1564 } 1565 1566 static void __net_exit fib_net_exit(struct net *net) 1567 { 1568 fib_proc_exit(net); 1569 nl_fib_lookup_exit(net); 1570 ip_fib_net_exit(net); 1571 } 1572 1573 static struct pernet_operations fib_net_ops = { 1574 .init = fib_net_init, 1575 .exit = fib_net_exit, 1576 }; 1577 1578 void __init ip_fib_init(void) 1579 { 1580 fib_trie_init(); 1581 1582 register_pernet_subsys(&fib_net_ops); 1583 1584 register_netdevice_notifier(&fib_netdev_notifier); 1585 register_inetaddr_notifier(&fib_inetaddr_notifier); 1586 1587 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0); 1588 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0); 1589 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0); 1590 } 1591