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