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/nexthop.h> 43 #include <net/rtnetlink.h> 44 #include <net/xfrm.h> 45 #include <net/l3mdev.h> 46 #include <net/lwtunnel.h> 47 #include <trace/events/fib.h> 48 49 #ifndef CONFIG_IP_MULTIPLE_TABLES 50 51 static int __net_init fib4_rules_init(struct net *net) 52 { 53 struct fib_table *local_table, *main_table; 54 55 main_table = fib_trie_table(RT_TABLE_MAIN, NULL); 56 if (!main_table) 57 return -ENOMEM; 58 59 local_table = fib_trie_table(RT_TABLE_LOCAL, main_table); 60 if (!local_table) 61 goto fail; 62 63 hlist_add_head_rcu(&local_table->tb_hlist, 64 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]); 65 hlist_add_head_rcu(&main_table->tb_hlist, 66 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]); 67 return 0; 68 69 fail: 70 fib_free_table(main_table); 71 return -ENOMEM; 72 } 73 74 static bool fib4_has_custom_rules(struct net *net) 75 { 76 return false; 77 } 78 #else 79 80 struct fib_table *fib_new_table(struct net *net, u32 id) 81 { 82 struct fib_table *tb, *alias = NULL; 83 unsigned int h; 84 85 if (id == 0) 86 id = RT_TABLE_MAIN; 87 tb = fib_get_table(net, id); 88 if (tb) 89 return tb; 90 91 if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules) 92 alias = fib_new_table(net, RT_TABLE_MAIN); 93 94 tb = fib_trie_table(id, alias); 95 if (!tb) 96 return NULL; 97 98 switch (id) { 99 case RT_TABLE_MAIN: 100 rcu_assign_pointer(net->ipv4.fib_main, tb); 101 break; 102 case RT_TABLE_DEFAULT: 103 rcu_assign_pointer(net->ipv4.fib_default, tb); 104 break; 105 default: 106 break; 107 } 108 109 h = id & (FIB_TABLE_HASHSZ - 1); 110 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]); 111 return tb; 112 } 113 EXPORT_SYMBOL_GPL(fib_new_table); 114 115 /* caller must hold either rtnl or rcu read lock */ 116 struct fib_table *fib_get_table(struct net *net, u32 id) 117 { 118 struct fib_table *tb; 119 struct hlist_head *head; 120 unsigned int h; 121 122 if (id == 0) 123 id = RT_TABLE_MAIN; 124 h = id & (FIB_TABLE_HASHSZ - 1); 125 126 head = &net->ipv4.fib_table_hash[h]; 127 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 128 if (tb->tb_id == id) 129 return tb; 130 } 131 return NULL; 132 } 133 134 static bool fib4_has_custom_rules(struct net *net) 135 { 136 return net->ipv4.fib_has_custom_rules; 137 } 138 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 139 140 static void fib_replace_table(struct net *net, struct fib_table *old, 141 struct fib_table *new) 142 { 143 #ifdef CONFIG_IP_MULTIPLE_TABLES 144 switch (new->tb_id) { 145 case RT_TABLE_MAIN: 146 rcu_assign_pointer(net->ipv4.fib_main, new); 147 break; 148 case RT_TABLE_DEFAULT: 149 rcu_assign_pointer(net->ipv4.fib_default, new); 150 break; 151 default: 152 break; 153 } 154 155 #endif 156 /* replace the old table in the hlist */ 157 hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist); 158 } 159 160 int fib_unmerge(struct net *net) 161 { 162 struct fib_table *old, *new, *main_table; 163 164 /* attempt to fetch local table if it has been allocated */ 165 old = fib_get_table(net, RT_TABLE_LOCAL); 166 if (!old) 167 return 0; 168 169 new = fib_trie_unmerge(old); 170 if (!new) 171 return -ENOMEM; 172 173 /* table is already unmerged */ 174 if (new == old) 175 return 0; 176 177 /* replace merged table with clean table */ 178 fib_replace_table(net, old, new); 179 fib_free_table(old); 180 181 /* attempt to fetch main table if it has been allocated */ 182 main_table = fib_get_table(net, RT_TABLE_MAIN); 183 if (!main_table) 184 return 0; 185 186 /* flush local entries from main table */ 187 fib_table_flush_external(main_table); 188 189 return 0; 190 } 191 192 void fib_flush(struct net *net) 193 { 194 int flushed = 0; 195 unsigned int h; 196 197 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 198 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 199 struct hlist_node *tmp; 200 struct fib_table *tb; 201 202 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) 203 flushed += fib_table_flush(net, tb, false); 204 } 205 206 if (flushed) 207 rt_cache_flush(net); 208 } 209 210 /* 211 * Find address type as if only "dev" was present in the system. If 212 * on_dev is NULL then all interfaces are taken into consideration. 213 */ 214 static inline unsigned int __inet_dev_addr_type(struct net *net, 215 const struct net_device *dev, 216 __be32 addr, u32 tb_id) 217 { 218 struct flowi4 fl4 = { .daddr = addr }; 219 struct fib_result res; 220 unsigned int ret = RTN_BROADCAST; 221 struct fib_table *table; 222 223 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr)) 224 return RTN_BROADCAST; 225 if (ipv4_is_multicast(addr)) 226 return RTN_MULTICAST; 227 228 rcu_read_lock(); 229 230 table = fib_get_table(net, tb_id); 231 if (table) { 232 ret = RTN_UNICAST; 233 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) { 234 struct fib_nh_common *nhc = fib_info_nhc(res.fi, 0); 235 236 if (!dev || dev == nhc->nhc_dev) 237 ret = res.type; 238 } 239 } 240 241 rcu_read_unlock(); 242 return ret; 243 } 244 245 unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id) 246 { 247 return __inet_dev_addr_type(net, NULL, addr, tb_id); 248 } 249 EXPORT_SYMBOL(inet_addr_type_table); 250 251 unsigned int inet_addr_type(struct net *net, __be32 addr) 252 { 253 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL); 254 } 255 EXPORT_SYMBOL(inet_addr_type); 256 257 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, 258 __be32 addr) 259 { 260 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL; 261 262 return __inet_dev_addr_type(net, dev, addr, rt_table); 263 } 264 EXPORT_SYMBOL(inet_dev_addr_type); 265 266 /* inet_addr_type with dev == NULL but using the table from a dev 267 * if one is associated 268 */ 269 unsigned int inet_addr_type_dev_table(struct net *net, 270 const struct net_device *dev, 271 __be32 addr) 272 { 273 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL; 274 275 return __inet_dev_addr_type(net, NULL, addr, rt_table); 276 } 277 EXPORT_SYMBOL(inet_addr_type_dev_table); 278 279 __be32 fib_compute_spec_dst(struct sk_buff *skb) 280 { 281 struct net_device *dev = skb->dev; 282 struct in_device *in_dev; 283 struct fib_result res; 284 struct rtable *rt; 285 struct net *net; 286 int scope; 287 288 rt = skb_rtable(skb); 289 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) == 290 RTCF_LOCAL) 291 return ip_hdr(skb)->daddr; 292 293 in_dev = __in_dev_get_rcu(dev); 294 295 net = dev_net(dev); 296 297 scope = RT_SCOPE_UNIVERSE; 298 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) { 299 bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev); 300 struct flowi4 fl4 = { 301 .flowi4_iif = LOOPBACK_IFINDEX, 302 .flowi4_oif = l3mdev_master_ifindex_rcu(dev), 303 .daddr = ip_hdr(skb)->saddr, 304 .flowi4_tos = RT_TOS(ip_hdr(skb)->tos), 305 .flowi4_scope = scope, 306 .flowi4_mark = vmark ? skb->mark : 0, 307 }; 308 if (!fib_lookup(net, &fl4, &res, 0)) 309 return fib_result_prefsrc(net, &res); 310 } else { 311 scope = RT_SCOPE_LINK; 312 } 313 314 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope); 315 } 316 317 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev) 318 { 319 bool dev_match = false; 320 #ifdef CONFIG_IP_ROUTE_MULTIPATH 321 int ret; 322 323 for (ret = 0; ret < fib_info_num_path(fi); ret++) { 324 const struct fib_nh_common *nhc = fib_info_nhc(fi, ret); 325 326 if (nhc->nhc_dev == dev) { 327 dev_match = true; 328 break; 329 } else if (l3mdev_master_ifindex_rcu(nhc->nhc_dev) == dev->ifindex) { 330 dev_match = true; 331 break; 332 } 333 } 334 #else 335 if (fib_info_nhc(fi, 0)->nhc_dev == dev) 336 dev_match = true; 337 #endif 338 339 return dev_match; 340 } 341 EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev); 342 343 /* Given (packet source, input interface) and optional (dst, oif, tos): 344 * - (main) check, that source is valid i.e. not broadcast or our local 345 * address. 346 * - figure out what "logical" interface this packet arrived 347 * and calculate "specific destination" address. 348 * - check, that packet arrived from expected physical interface. 349 * called with rcu_read_lock() 350 */ 351 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 352 u8 tos, int oif, struct net_device *dev, 353 int rpf, struct in_device *idev, u32 *itag) 354 { 355 struct net *net = dev_net(dev); 356 struct flow_keys flkeys; 357 int ret, no_addr; 358 struct fib_result res; 359 struct flowi4 fl4; 360 bool dev_match; 361 362 fl4.flowi4_oif = 0; 363 fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev); 364 if (!fl4.flowi4_iif) 365 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX; 366 fl4.daddr = src; 367 fl4.saddr = dst; 368 fl4.flowi4_tos = tos; 369 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 370 fl4.flowi4_tun_key.tun_id = 0; 371 fl4.flowi4_flags = 0; 372 fl4.flowi4_uid = sock_net_uid(net, NULL); 373 374 no_addr = idev->ifa_list == NULL; 375 376 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0; 377 if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) { 378 fl4.flowi4_proto = 0; 379 fl4.fl4_sport = 0; 380 fl4.fl4_dport = 0; 381 } 382 383 if (fib_lookup(net, &fl4, &res, 0)) 384 goto last_resort; 385 if (res.type != RTN_UNICAST && 386 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev))) 387 goto e_inval; 388 fib_combine_itag(itag, &res); 389 390 dev_match = fib_info_nh_uses_dev(res.fi, dev); 391 if (dev_match) { 392 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; 393 return ret; 394 } 395 if (no_addr) 396 goto last_resort; 397 if (rpf == 1) 398 goto e_rpf; 399 fl4.flowi4_oif = dev->ifindex; 400 401 ret = 0; 402 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) { 403 if (res.type == RTN_UNICAST) 404 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; 405 } 406 return ret; 407 408 last_resort: 409 if (rpf) 410 goto e_rpf; 411 *itag = 0; 412 return 0; 413 414 e_inval: 415 return -EINVAL; 416 e_rpf: 417 return -EXDEV; 418 } 419 420 /* Ignore rp_filter for packets protected by IPsec. */ 421 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 422 u8 tos, int oif, struct net_device *dev, 423 struct in_device *idev, u32 *itag) 424 { 425 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev); 426 struct net *net = dev_net(dev); 427 428 if (!r && !fib_num_tclassid_users(net) && 429 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) { 430 if (IN_DEV_ACCEPT_LOCAL(idev)) 431 goto ok; 432 /* with custom local routes in place, checking local addresses 433 * only will be too optimistic, with custom rules, checking 434 * local addresses only can be too strict, e.g. due to vrf 435 */ 436 if (net->ipv4.fib_has_custom_local_routes || 437 fib4_has_custom_rules(net)) 438 goto full_check; 439 if (inet_lookup_ifaddr_rcu(net, src)) 440 return -EINVAL; 441 442 ok: 443 *itag = 0; 444 return 0; 445 } 446 447 full_check: 448 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag); 449 } 450 451 static inline __be32 sk_extract_addr(struct sockaddr *addr) 452 { 453 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 454 } 455 456 static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 457 { 458 struct nlattr *nla; 459 460 nla = (struct nlattr *) ((char *) mx + len); 461 nla->nla_type = type; 462 nla->nla_len = nla_attr_size(4); 463 *(u32 *) nla_data(nla) = value; 464 465 return len + nla_total_size(4); 466 } 467 468 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 469 struct fib_config *cfg) 470 { 471 __be32 addr; 472 int plen; 473 474 memset(cfg, 0, sizeof(*cfg)); 475 cfg->fc_nlinfo.nl_net = net; 476 477 if (rt->rt_dst.sa_family != AF_INET) 478 return -EAFNOSUPPORT; 479 480 /* 481 * Check mask for validity: 482 * a) it must be contiguous. 483 * b) destination must have all host bits clear. 484 * c) if application forgot to set correct family (AF_INET), 485 * reject request unless it is absolutely clear i.e. 486 * both family and mask are zero. 487 */ 488 plen = 32; 489 addr = sk_extract_addr(&rt->rt_dst); 490 if (!(rt->rt_flags & RTF_HOST)) { 491 __be32 mask = sk_extract_addr(&rt->rt_genmask); 492 493 if (rt->rt_genmask.sa_family != AF_INET) { 494 if (mask || rt->rt_genmask.sa_family) 495 return -EAFNOSUPPORT; 496 } 497 498 if (bad_mask(mask, addr)) 499 return -EINVAL; 500 501 plen = inet_mask_len(mask); 502 } 503 504 cfg->fc_dst_len = plen; 505 cfg->fc_dst = addr; 506 507 if (cmd != SIOCDELRT) { 508 cfg->fc_nlflags = NLM_F_CREATE; 509 cfg->fc_protocol = RTPROT_BOOT; 510 } 511 512 if (rt->rt_metric) 513 cfg->fc_priority = rt->rt_metric - 1; 514 515 if (rt->rt_flags & RTF_REJECT) { 516 cfg->fc_scope = RT_SCOPE_HOST; 517 cfg->fc_type = RTN_UNREACHABLE; 518 return 0; 519 } 520 521 cfg->fc_scope = RT_SCOPE_NOWHERE; 522 cfg->fc_type = RTN_UNICAST; 523 524 if (rt->rt_dev) { 525 char *colon; 526 struct net_device *dev; 527 char devname[IFNAMSIZ]; 528 529 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 530 return -EFAULT; 531 532 devname[IFNAMSIZ-1] = 0; 533 colon = strchr(devname, ':'); 534 if (colon) 535 *colon = 0; 536 dev = __dev_get_by_name(net, devname); 537 if (!dev) 538 return -ENODEV; 539 cfg->fc_oif = dev->ifindex; 540 cfg->fc_table = l3mdev_fib_table(dev); 541 if (colon) { 542 const struct in_ifaddr *ifa; 543 struct in_device *in_dev; 544 545 in_dev = __in_dev_get_rtnl(dev); 546 if (!in_dev) 547 return -ENODEV; 548 549 *colon = ':'; 550 551 rcu_read_lock(); 552 in_dev_for_each_ifa_rcu(ifa, in_dev) { 553 if (strcmp(ifa->ifa_label, devname) == 0) 554 break; 555 } 556 rcu_read_unlock(); 557 558 if (!ifa) 559 return -ENODEV; 560 cfg->fc_prefsrc = ifa->ifa_local; 561 } 562 } 563 564 addr = sk_extract_addr(&rt->rt_gateway); 565 if (rt->rt_gateway.sa_family == AF_INET && addr) { 566 unsigned int addr_type; 567 568 cfg->fc_gw4 = addr; 569 cfg->fc_gw_family = AF_INET; 570 addr_type = inet_addr_type_table(net, addr, cfg->fc_table); 571 if (rt->rt_flags & RTF_GATEWAY && 572 addr_type == RTN_UNICAST) 573 cfg->fc_scope = RT_SCOPE_UNIVERSE; 574 } 575 576 if (cmd == SIOCDELRT) 577 return 0; 578 579 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family) 580 return -EINVAL; 581 582 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 583 cfg->fc_scope = RT_SCOPE_LINK; 584 585 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 586 struct nlattr *mx; 587 int len = 0; 588 589 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL); 590 if (!mx) 591 return -ENOMEM; 592 593 if (rt->rt_flags & RTF_MTU) 594 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 595 596 if (rt->rt_flags & RTF_WINDOW) 597 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 598 599 if (rt->rt_flags & RTF_IRTT) 600 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 601 602 cfg->fc_mx = mx; 603 cfg->fc_mx_len = len; 604 } 605 606 return 0; 607 } 608 609 /* 610 * Handle IP routing ioctl calls. 611 * These are used to manipulate the routing tables 612 */ 613 int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt) 614 { 615 struct fib_config cfg; 616 int err; 617 618 switch (cmd) { 619 case SIOCADDRT: /* Add a route */ 620 case SIOCDELRT: /* Delete a route */ 621 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 622 return -EPERM; 623 624 rtnl_lock(); 625 err = rtentry_to_fib_config(net, cmd, rt, &cfg); 626 if (err == 0) { 627 struct fib_table *tb; 628 629 if (cmd == SIOCDELRT) { 630 tb = fib_get_table(net, cfg.fc_table); 631 if (tb) 632 err = fib_table_delete(net, tb, &cfg, 633 NULL); 634 else 635 err = -ESRCH; 636 } else { 637 tb = fib_new_table(net, cfg.fc_table); 638 if (tb) 639 err = fib_table_insert(net, tb, 640 &cfg, NULL); 641 else 642 err = -ENOBUFS; 643 } 644 645 /* allocated by rtentry_to_fib_config() */ 646 kfree(cfg.fc_mx); 647 } 648 rtnl_unlock(); 649 return err; 650 } 651 return -EINVAL; 652 } 653 654 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 655 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 }, 656 [RTA_DST] = { .type = NLA_U32 }, 657 [RTA_SRC] = { .type = NLA_U32 }, 658 [RTA_IIF] = { .type = NLA_U32 }, 659 [RTA_OIF] = { .type = NLA_U32 }, 660 [RTA_GATEWAY] = { .type = NLA_U32 }, 661 [RTA_PRIORITY] = { .type = NLA_U32 }, 662 [RTA_PREFSRC] = { .type = NLA_U32 }, 663 [RTA_METRICS] = { .type = NLA_NESTED }, 664 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 665 [RTA_FLOW] = { .type = NLA_U32 }, 666 [RTA_ENCAP_TYPE] = { .type = NLA_U16 }, 667 [RTA_ENCAP] = { .type = NLA_NESTED }, 668 [RTA_UID] = { .type = NLA_U32 }, 669 [RTA_MARK] = { .type = NLA_U32 }, 670 [RTA_TABLE] = { .type = NLA_U32 }, 671 [RTA_IP_PROTO] = { .type = NLA_U8 }, 672 [RTA_SPORT] = { .type = NLA_U16 }, 673 [RTA_DPORT] = { .type = NLA_U16 }, 674 [RTA_NH_ID] = { .type = NLA_U32 }, 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 case RTA_NH_ID: 813 cfg->fc_nh_id = nla_get_u32(attr); 814 break; 815 } 816 } 817 818 if (cfg->fc_nh_id) { 819 if (cfg->fc_oif || cfg->fc_gw_family || 820 cfg->fc_encap || cfg->fc_mp) { 821 NL_SET_ERR_MSG(extack, 822 "Nexthop specification and nexthop id are mutually exclusive"); 823 return -EINVAL; 824 } 825 } 826 827 if (has_gw && has_via) { 828 NL_SET_ERR_MSG(extack, 829 "Nexthop configuration can not contain both GATEWAY and VIA"); 830 goto errout; 831 } 832 833 return 0; 834 errout: 835 return err; 836 } 837 838 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, 839 struct netlink_ext_ack *extack) 840 { 841 struct net *net = sock_net(skb->sk); 842 struct fib_config cfg; 843 struct fib_table *tb; 844 int err; 845 846 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 847 if (err < 0) 848 goto errout; 849 850 if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) { 851 NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); 852 err = -EINVAL; 853 goto errout; 854 } 855 856 tb = fib_get_table(net, cfg.fc_table); 857 if (!tb) { 858 NL_SET_ERR_MSG(extack, "FIB table does not exist"); 859 err = -ESRCH; 860 goto errout; 861 } 862 863 err = fib_table_delete(net, tb, &cfg, extack); 864 errout: 865 return err; 866 } 867 868 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, 869 struct netlink_ext_ack *extack) 870 { 871 struct net *net = sock_net(skb->sk); 872 struct fib_config cfg; 873 struct fib_table *tb; 874 int err; 875 876 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 877 if (err < 0) 878 goto errout; 879 880 tb = fib_new_table(net, cfg.fc_table); 881 if (!tb) { 882 err = -ENOBUFS; 883 goto errout; 884 } 885 886 err = fib_table_insert(net, tb, &cfg, extack); 887 if (!err && cfg.fc_type == RTN_LOCAL) 888 net->ipv4.fib_has_custom_local_routes = true; 889 errout: 890 return err; 891 } 892 893 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 894 struct fib_dump_filter *filter, 895 struct netlink_callback *cb) 896 { 897 struct netlink_ext_ack *extack = cb->extack; 898 struct nlattr *tb[RTA_MAX + 1]; 899 struct rtmsg *rtm; 900 int err, i; 901 902 ASSERT_RTNL(); 903 904 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 905 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request"); 906 return -EINVAL; 907 } 908 909 rtm = nlmsg_data(nlh); 910 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos || 911 rtm->rtm_scope) { 912 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request"); 913 return -EINVAL; 914 } 915 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) { 916 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request"); 917 return -EINVAL; 918 } 919 920 filter->dump_all_families = (rtm->rtm_family == AF_UNSPEC); 921 filter->flags = rtm->rtm_flags; 922 filter->protocol = rtm->rtm_protocol; 923 filter->rt_type = rtm->rtm_type; 924 filter->table_id = rtm->rtm_table; 925 926 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 927 rtm_ipv4_policy, extack); 928 if (err < 0) 929 return err; 930 931 for (i = 0; i <= RTA_MAX; ++i) { 932 int ifindex; 933 934 if (!tb[i]) 935 continue; 936 937 switch (i) { 938 case RTA_TABLE: 939 filter->table_id = nla_get_u32(tb[i]); 940 break; 941 case RTA_OIF: 942 ifindex = nla_get_u32(tb[i]); 943 filter->dev = __dev_get_by_index(net, ifindex); 944 if (!filter->dev) 945 return -ENODEV; 946 break; 947 default: 948 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request"); 949 return -EINVAL; 950 } 951 } 952 953 if (filter->flags || filter->protocol || filter->rt_type || 954 filter->table_id || filter->dev) { 955 filter->filter_set = 1; 956 cb->answer_flags = NLM_F_DUMP_FILTERED; 957 } 958 959 return 0; 960 } 961 EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req); 962 963 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 964 { 965 const struct nlmsghdr *nlh = cb->nlh; 966 struct net *net = sock_net(skb->sk); 967 struct fib_dump_filter filter = {}; 968 unsigned int h, s_h; 969 unsigned int e = 0, s_e; 970 struct fib_table *tb; 971 struct hlist_head *head; 972 int dumped = 0, err; 973 974 if (cb->strict_check) { 975 err = ip_valid_fib_dump_req(net, nlh, &filter, cb); 976 if (err < 0) 977 return err; 978 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 979 struct rtmsg *rtm = nlmsg_data(nlh); 980 981 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED); 982 } 983 984 /* fib entries are never clones and ipv4 does not use prefix flag */ 985 if (filter.flags & (RTM_F_PREFIX | RTM_F_CLONED)) 986 return skb->len; 987 988 if (filter.table_id) { 989 tb = fib_get_table(net, filter.table_id); 990 if (!tb) { 991 if (filter.dump_all_families) 992 return skb->len; 993 994 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist"); 995 return -ENOENT; 996 } 997 998 err = fib_table_dump(tb, skb, cb, &filter); 999 return skb->len ? : err; 1000 } 1001 1002 s_h = cb->args[0]; 1003 s_e = cb->args[1]; 1004 1005 rcu_read_lock(); 1006 1007 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 1008 e = 0; 1009 head = &net->ipv4.fib_table_hash[h]; 1010 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 1011 if (e < s_e) 1012 goto next; 1013 if (dumped) 1014 memset(&cb->args[2], 0, sizeof(cb->args) - 1015 2 * sizeof(cb->args[0])); 1016 err = fib_table_dump(tb, skb, cb, &filter); 1017 if (err < 0) { 1018 if (likely(skb->len)) 1019 goto out; 1020 1021 goto out_err; 1022 } 1023 dumped = 1; 1024 next: 1025 e++; 1026 } 1027 } 1028 out: 1029 err = skb->len; 1030 out_err: 1031 rcu_read_unlock(); 1032 1033 cb->args[1] = e; 1034 cb->args[0] = h; 1035 1036 return err; 1037 } 1038 1039 /* Prepare and feed intra-kernel routing request. 1040 * Really, it should be netlink message, but :-( netlink 1041 * can be not configured, so that we feed it directly 1042 * to fib engine. It is legal, because all events occur 1043 * only when netlink is already locked. 1044 */ 1045 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, 1046 struct in_ifaddr *ifa, u32 rt_priority) 1047 { 1048 struct net *net = dev_net(ifa->ifa_dev->dev); 1049 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev); 1050 struct fib_table *tb; 1051 struct fib_config cfg = { 1052 .fc_protocol = RTPROT_KERNEL, 1053 .fc_type = type, 1054 .fc_dst = dst, 1055 .fc_dst_len = dst_len, 1056 .fc_priority = rt_priority, 1057 .fc_prefsrc = ifa->ifa_local, 1058 .fc_oif = ifa->ifa_dev->dev->ifindex, 1059 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 1060 .fc_nlinfo = { 1061 .nl_net = net, 1062 }, 1063 }; 1064 1065 if (!tb_id) 1066 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL; 1067 1068 tb = fib_new_table(net, tb_id); 1069 if (!tb) 1070 return; 1071 1072 cfg.fc_table = tb->tb_id; 1073 1074 if (type != RTN_LOCAL) 1075 cfg.fc_scope = RT_SCOPE_LINK; 1076 else 1077 cfg.fc_scope = RT_SCOPE_HOST; 1078 1079 if (cmd == RTM_NEWROUTE) 1080 fib_table_insert(net, tb, &cfg, NULL); 1081 else 1082 fib_table_delete(net, tb, &cfg, NULL); 1083 } 1084 1085 void fib_add_ifaddr(struct in_ifaddr *ifa) 1086 { 1087 struct in_device *in_dev = ifa->ifa_dev; 1088 struct net_device *dev = in_dev->dev; 1089 struct in_ifaddr *prim = ifa; 1090 __be32 mask = ifa->ifa_mask; 1091 __be32 addr = ifa->ifa_local; 1092 __be32 prefix = ifa->ifa_address & mask; 1093 1094 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1095 prim = inet_ifa_byprefix(in_dev, prefix, mask); 1096 if (!prim) { 1097 pr_warn("%s: bug: prim == NULL\n", __func__); 1098 return; 1099 } 1100 } 1101 1102 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0); 1103 1104 if (!(dev->flags & IFF_UP)) 1105 return; 1106 1107 /* Add broadcast address, if it is explicitly assigned. */ 1108 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 1109 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1110 prim, 0); 1111 1112 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 1113 (prefix != addr || ifa->ifa_prefixlen < 32)) { 1114 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1115 fib_magic(RTM_NEWROUTE, 1116 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1117 prefix, ifa->ifa_prefixlen, prim, 1118 ifa->ifa_rt_priority); 1119 1120 /* Add network specific broadcasts, when it takes a sense */ 1121 if (ifa->ifa_prefixlen < 31) { 1122 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, 1123 prim, 0); 1124 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 1125 32, prim, 0); 1126 } 1127 } 1128 } 1129 1130 void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric) 1131 { 1132 __be32 prefix = ifa->ifa_address & ifa->ifa_mask; 1133 struct in_device *in_dev = ifa->ifa_dev; 1134 struct net_device *dev = in_dev->dev; 1135 1136 if (!(dev->flags & IFF_UP) || 1137 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) || 1138 ipv4_is_zeronet(prefix) || 1139 prefix == ifa->ifa_local || ifa->ifa_prefixlen == 32) 1140 return; 1141 1142 /* add the new */ 1143 fib_magic(RTM_NEWROUTE, 1144 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1145 prefix, ifa->ifa_prefixlen, ifa, new_metric); 1146 1147 /* delete the old */ 1148 fib_magic(RTM_DELROUTE, 1149 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1150 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority); 1151 } 1152 1153 /* Delete primary or secondary address. 1154 * Optionally, on secondary address promotion consider the addresses 1155 * from subnet iprim as deleted, even if they are in device list. 1156 * In this case the secondary ifa can be in device list. 1157 */ 1158 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 1159 { 1160 struct in_device *in_dev = ifa->ifa_dev; 1161 struct net_device *dev = in_dev->dev; 1162 struct in_ifaddr *ifa1; 1163 struct in_ifaddr *prim = ifa, *prim1 = NULL; 1164 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 1165 __be32 any = ifa->ifa_address & ifa->ifa_mask; 1166 #define LOCAL_OK 1 1167 #define BRD_OK 2 1168 #define BRD0_OK 4 1169 #define BRD1_OK 8 1170 unsigned int ok = 0; 1171 int subnet = 0; /* Primary network */ 1172 int gone = 1; /* Address is missing */ 1173 int same_prefsrc = 0; /* Another primary with same IP */ 1174 1175 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1176 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 1177 if (!prim) { 1178 /* if the device has been deleted, we don't perform 1179 * address promotion 1180 */ 1181 if (!in_dev->dead) 1182 pr_warn("%s: bug: prim == NULL\n", __func__); 1183 return; 1184 } 1185 if (iprim && iprim != prim) { 1186 pr_warn("%s: bug: iprim != prim\n", __func__); 1187 return; 1188 } 1189 } else if (!ipv4_is_zeronet(any) && 1190 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 1191 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1192 fib_magic(RTM_DELROUTE, 1193 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1194 any, ifa->ifa_prefixlen, prim, 0); 1195 subnet = 1; 1196 } 1197 1198 if (in_dev->dead) 1199 goto no_promotions; 1200 1201 /* Deletion is more complicated than add. 1202 * We should take care of not to delete too much :-) 1203 * 1204 * Scan address list to be sure that addresses are really gone. 1205 */ 1206 rcu_read_lock(); 1207 in_dev_for_each_ifa_rcu(ifa1, in_dev) { 1208 if (ifa1 == ifa) { 1209 /* promotion, keep the IP */ 1210 gone = 0; 1211 continue; 1212 } 1213 /* Ignore IFAs from our subnet */ 1214 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 1215 inet_ifa_match(ifa1->ifa_address, iprim)) 1216 continue; 1217 1218 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 1219 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 1220 /* Another address from our subnet? */ 1221 if (ifa1->ifa_mask == prim->ifa_mask && 1222 inet_ifa_match(ifa1->ifa_address, prim)) 1223 prim1 = prim; 1224 else { 1225 /* We reached the secondaries, so 1226 * same_prefsrc should be determined. 1227 */ 1228 if (!same_prefsrc) 1229 continue; 1230 /* Search new prim1 if ifa1 is not 1231 * using the current prim1 1232 */ 1233 if (!prim1 || 1234 ifa1->ifa_mask != prim1->ifa_mask || 1235 !inet_ifa_match(ifa1->ifa_address, prim1)) 1236 prim1 = inet_ifa_byprefix(in_dev, 1237 ifa1->ifa_address, 1238 ifa1->ifa_mask); 1239 if (!prim1) 1240 continue; 1241 if (prim1->ifa_local != prim->ifa_local) 1242 continue; 1243 } 1244 } else { 1245 if (prim->ifa_local != ifa1->ifa_local) 1246 continue; 1247 prim1 = ifa1; 1248 if (prim != prim1) 1249 same_prefsrc = 1; 1250 } 1251 if (ifa->ifa_local == ifa1->ifa_local) 1252 ok |= LOCAL_OK; 1253 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 1254 ok |= BRD_OK; 1255 if (brd == ifa1->ifa_broadcast) 1256 ok |= BRD1_OK; 1257 if (any == ifa1->ifa_broadcast) 1258 ok |= BRD0_OK; 1259 /* primary has network specific broadcasts */ 1260 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 1261 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 1262 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 1263 1264 if (!ipv4_is_zeronet(any1)) { 1265 if (ifa->ifa_broadcast == brd1 || 1266 ifa->ifa_broadcast == any1) 1267 ok |= BRD_OK; 1268 if (brd == brd1 || brd == any1) 1269 ok |= BRD1_OK; 1270 if (any == brd1 || any == any1) 1271 ok |= BRD0_OK; 1272 } 1273 } 1274 } 1275 rcu_read_unlock(); 1276 1277 no_promotions: 1278 if (!(ok & BRD_OK)) 1279 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1280 prim, 0); 1281 if (subnet && ifa->ifa_prefixlen < 31) { 1282 if (!(ok & BRD1_OK)) 1283 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, 1284 prim, 0); 1285 if (!(ok & BRD0_OK)) 1286 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, 1287 prim, 0); 1288 } 1289 if (!(ok & LOCAL_OK)) { 1290 unsigned int addr_type; 1291 1292 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0); 1293 1294 /* Check, that this local address finally disappeared. */ 1295 addr_type = inet_addr_type_dev_table(dev_net(dev), dev, 1296 ifa->ifa_local); 1297 if (gone && addr_type != RTN_LOCAL) { 1298 /* And the last, but not the least thing. 1299 * We must flush stray FIB entries. 1300 * 1301 * First of all, we scan fib_info list searching 1302 * for stray nexthop entries, then ignite fib_flush. 1303 */ 1304 if (fib_sync_down_addr(dev, ifa->ifa_local)) 1305 fib_flush(dev_net(dev)); 1306 } 1307 } 1308 #undef LOCAL_OK 1309 #undef BRD_OK 1310 #undef BRD0_OK 1311 #undef BRD1_OK 1312 } 1313 1314 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn) 1315 { 1316 1317 struct fib_result res; 1318 struct flowi4 fl4 = { 1319 .flowi4_mark = frn->fl_mark, 1320 .daddr = frn->fl_addr, 1321 .flowi4_tos = frn->fl_tos, 1322 .flowi4_scope = frn->fl_scope, 1323 }; 1324 struct fib_table *tb; 1325 1326 rcu_read_lock(); 1327 1328 tb = fib_get_table(net, frn->tb_id_in); 1329 1330 frn->err = -ENOENT; 1331 if (tb) { 1332 local_bh_disable(); 1333 1334 frn->tb_id = tb->tb_id; 1335 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 1336 1337 if (!frn->err) { 1338 frn->prefixlen = res.prefixlen; 1339 frn->nh_sel = res.nh_sel; 1340 frn->type = res.type; 1341 frn->scope = res.scope; 1342 } 1343 local_bh_enable(); 1344 } 1345 1346 rcu_read_unlock(); 1347 } 1348 1349 static void nl_fib_input(struct sk_buff *skb) 1350 { 1351 struct net *net; 1352 struct fib_result_nl *frn; 1353 struct nlmsghdr *nlh; 1354 u32 portid; 1355 1356 net = sock_net(skb->sk); 1357 nlh = nlmsg_hdr(skb); 1358 if (skb->len < nlmsg_total_size(sizeof(*frn)) || 1359 skb->len < nlh->nlmsg_len || 1360 nlmsg_len(nlh) < sizeof(*frn)) 1361 return; 1362 1363 skb = netlink_skb_clone(skb, GFP_KERNEL); 1364 if (!skb) 1365 return; 1366 nlh = nlmsg_hdr(skb); 1367 1368 frn = (struct fib_result_nl *) nlmsg_data(nlh); 1369 nl_fib_lookup(net, frn); 1370 1371 portid = NETLINK_CB(skb).portid; /* netlink portid */ 1372 NETLINK_CB(skb).portid = 0; /* from kernel */ 1373 NETLINK_CB(skb).dst_group = 0; /* unicast */ 1374 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT); 1375 } 1376 1377 static int __net_init nl_fib_lookup_init(struct net *net) 1378 { 1379 struct sock *sk; 1380 struct netlink_kernel_cfg cfg = { 1381 .input = nl_fib_input, 1382 }; 1383 1384 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg); 1385 if (!sk) 1386 return -EAFNOSUPPORT; 1387 net->ipv4.fibnl = sk; 1388 return 0; 1389 } 1390 1391 static void nl_fib_lookup_exit(struct net *net) 1392 { 1393 netlink_kernel_release(net->ipv4.fibnl); 1394 net->ipv4.fibnl = NULL; 1395 } 1396 1397 static void fib_disable_ip(struct net_device *dev, unsigned long event, 1398 bool force) 1399 { 1400 if (fib_sync_down_dev(dev, event, force)) 1401 fib_flush(dev_net(dev)); 1402 else 1403 rt_cache_flush(dev_net(dev)); 1404 arp_ifdown(dev); 1405 } 1406 1407 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 1408 { 1409 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 1410 struct net_device *dev = ifa->ifa_dev->dev; 1411 struct net *net = dev_net(dev); 1412 1413 switch (event) { 1414 case NETDEV_UP: 1415 fib_add_ifaddr(ifa); 1416 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1417 fib_sync_up(dev, RTNH_F_DEAD); 1418 #endif 1419 atomic_inc(&net->ipv4.dev_addr_genid); 1420 rt_cache_flush(dev_net(dev)); 1421 break; 1422 case NETDEV_DOWN: 1423 fib_del_ifaddr(ifa, NULL); 1424 atomic_inc(&net->ipv4.dev_addr_genid); 1425 if (!ifa->ifa_dev->ifa_list) { 1426 /* Last address was deleted from this interface. 1427 * Disable IP. 1428 */ 1429 fib_disable_ip(dev, event, true); 1430 } else { 1431 rt_cache_flush(dev_net(dev)); 1432 } 1433 break; 1434 } 1435 return NOTIFY_DONE; 1436 } 1437 1438 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1439 { 1440 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1441 struct netdev_notifier_changeupper_info *upper_info = ptr; 1442 struct netdev_notifier_info_ext *info_ext = ptr; 1443 struct in_device *in_dev; 1444 struct net *net = dev_net(dev); 1445 struct in_ifaddr *ifa; 1446 unsigned int flags; 1447 1448 if (event == NETDEV_UNREGISTER) { 1449 fib_disable_ip(dev, event, true); 1450 rt_flush_dev(dev); 1451 return NOTIFY_DONE; 1452 } 1453 1454 in_dev = __in_dev_get_rtnl(dev); 1455 if (!in_dev) 1456 return NOTIFY_DONE; 1457 1458 switch (event) { 1459 case NETDEV_UP: 1460 in_dev_for_each_ifa_rtnl(ifa, in_dev) { 1461 fib_add_ifaddr(ifa); 1462 } 1463 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1464 fib_sync_up(dev, RTNH_F_DEAD); 1465 #endif 1466 atomic_inc(&net->ipv4.dev_addr_genid); 1467 rt_cache_flush(net); 1468 break; 1469 case NETDEV_DOWN: 1470 fib_disable_ip(dev, event, false); 1471 break; 1472 case NETDEV_CHANGE: 1473 flags = dev_get_flags(dev); 1474 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1475 fib_sync_up(dev, RTNH_F_LINKDOWN); 1476 else 1477 fib_sync_down_dev(dev, event, false); 1478 rt_cache_flush(net); 1479 break; 1480 case NETDEV_CHANGEMTU: 1481 fib_sync_mtu(dev, info_ext->ext.mtu); 1482 rt_cache_flush(net); 1483 break; 1484 case NETDEV_CHANGEUPPER: 1485 upper_info = ptr; 1486 /* flush all routes if dev is linked to or unlinked from 1487 * an L3 master device (e.g., VRF) 1488 */ 1489 if (upper_info->upper_dev && 1490 netif_is_l3_master(upper_info->upper_dev)) 1491 fib_disable_ip(dev, NETDEV_DOWN, true); 1492 break; 1493 } 1494 return NOTIFY_DONE; 1495 } 1496 1497 static struct notifier_block fib_inetaddr_notifier = { 1498 .notifier_call = fib_inetaddr_event, 1499 }; 1500 1501 static struct notifier_block fib_netdev_notifier = { 1502 .notifier_call = fib_netdev_event, 1503 }; 1504 1505 static int __net_init ip_fib_net_init(struct net *net) 1506 { 1507 int err; 1508 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1509 1510 err = fib4_notifier_init(net); 1511 if (err) 1512 return err; 1513 1514 /* Avoid false sharing : Use at least a full cache line */ 1515 size = max_t(size_t, size, L1_CACHE_BYTES); 1516 1517 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1518 if (!net->ipv4.fib_table_hash) { 1519 err = -ENOMEM; 1520 goto err_table_hash_alloc; 1521 } 1522 1523 err = fib4_rules_init(net); 1524 if (err < 0) 1525 goto err_rules_init; 1526 return 0; 1527 1528 err_rules_init: 1529 kfree(net->ipv4.fib_table_hash); 1530 err_table_hash_alloc: 1531 fib4_notifier_exit(net); 1532 return err; 1533 } 1534 1535 static void ip_fib_net_exit(struct net *net) 1536 { 1537 int i; 1538 1539 rtnl_lock(); 1540 #ifdef CONFIG_IP_MULTIPLE_TABLES 1541 RCU_INIT_POINTER(net->ipv4.fib_main, NULL); 1542 RCU_INIT_POINTER(net->ipv4.fib_default, NULL); 1543 #endif 1544 /* Destroy the tables in reverse order to guarantee that the 1545 * local table, ID 255, is destroyed before the main table, ID 1546 * 254. This is necessary as the local table may contain 1547 * references to data contained in the main table. 1548 */ 1549 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) { 1550 struct hlist_head *head = &net->ipv4.fib_table_hash[i]; 1551 struct hlist_node *tmp; 1552 struct fib_table *tb; 1553 1554 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) { 1555 hlist_del(&tb->tb_hlist); 1556 fib_table_flush(net, tb, true); 1557 fib_free_table(tb); 1558 } 1559 } 1560 1561 #ifdef CONFIG_IP_MULTIPLE_TABLES 1562 fib4_rules_exit(net); 1563 #endif 1564 rtnl_unlock(); 1565 kfree(net->ipv4.fib_table_hash); 1566 fib4_notifier_exit(net); 1567 } 1568 1569 static int __net_init fib_net_init(struct net *net) 1570 { 1571 int error; 1572 1573 #ifdef CONFIG_IP_ROUTE_CLASSID 1574 net->ipv4.fib_num_tclassid_users = 0; 1575 #endif 1576 error = ip_fib_net_init(net); 1577 if (error < 0) 1578 goto out; 1579 error = nl_fib_lookup_init(net); 1580 if (error < 0) 1581 goto out_nlfl; 1582 error = fib_proc_init(net); 1583 if (error < 0) 1584 goto out_proc; 1585 out: 1586 return error; 1587 1588 out_proc: 1589 nl_fib_lookup_exit(net); 1590 out_nlfl: 1591 ip_fib_net_exit(net); 1592 goto out; 1593 } 1594 1595 static void __net_exit fib_net_exit(struct net *net) 1596 { 1597 fib_proc_exit(net); 1598 nl_fib_lookup_exit(net); 1599 ip_fib_net_exit(net); 1600 } 1601 1602 static struct pernet_operations fib_net_ops = { 1603 .init = fib_net_init, 1604 .exit = fib_net_exit, 1605 }; 1606 1607 void __init ip_fib_init(void) 1608 { 1609 fib_trie_init(); 1610 1611 register_pernet_subsys(&fib_net_ops); 1612 1613 register_netdevice_notifier(&fib_netdev_notifier); 1614 register_inetaddr_notifier(&fib_inetaddr_notifier); 1615 1616 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0); 1617 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0); 1618 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0); 1619 } 1620