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