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 #else 74 75 struct fib_table *fib_new_table(struct net *net, u32 id) 76 { 77 struct fib_table *tb, *alias = NULL; 78 unsigned int h; 79 80 if (id == 0) 81 id = RT_TABLE_MAIN; 82 tb = fib_get_table(net, id); 83 if (tb) 84 return tb; 85 86 if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules) 87 alias = fib_new_table(net, RT_TABLE_MAIN); 88 89 tb = fib_trie_table(id, alias); 90 if (!tb) 91 return NULL; 92 93 switch (id) { 94 case RT_TABLE_MAIN: 95 rcu_assign_pointer(net->ipv4.fib_main, tb); 96 break; 97 case RT_TABLE_DEFAULT: 98 rcu_assign_pointer(net->ipv4.fib_default, tb); 99 break; 100 default: 101 break; 102 } 103 104 h = id & (FIB_TABLE_HASHSZ - 1); 105 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]); 106 return tb; 107 } 108 EXPORT_SYMBOL_GPL(fib_new_table); 109 110 /* caller must hold either rtnl or rcu read lock */ 111 struct fib_table *fib_get_table(struct net *net, u32 id) 112 { 113 struct fib_table *tb; 114 struct hlist_head *head; 115 unsigned int h; 116 117 if (id == 0) 118 id = RT_TABLE_MAIN; 119 h = id & (FIB_TABLE_HASHSZ - 1); 120 121 head = &net->ipv4.fib_table_hash[h]; 122 hlist_for_each_entry_rcu(tb, head, tb_hlist, 123 lockdep_rtnl_is_held()) { 124 if (tb->tb_id == id) 125 return tb; 126 } 127 return NULL; 128 } 129 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 130 131 static void fib_replace_table(struct net *net, struct fib_table *old, 132 struct fib_table *new) 133 { 134 #ifdef CONFIG_IP_MULTIPLE_TABLES 135 switch (new->tb_id) { 136 case RT_TABLE_MAIN: 137 rcu_assign_pointer(net->ipv4.fib_main, new); 138 break; 139 case RT_TABLE_DEFAULT: 140 rcu_assign_pointer(net->ipv4.fib_default, new); 141 break; 142 default: 143 break; 144 } 145 146 #endif 147 /* replace the old table in the hlist */ 148 hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist); 149 } 150 151 int fib_unmerge(struct net *net) 152 { 153 struct fib_table *old, *new, *main_table; 154 155 /* attempt to fetch local table if it has been allocated */ 156 old = fib_get_table(net, RT_TABLE_LOCAL); 157 if (!old) 158 return 0; 159 160 new = fib_trie_unmerge(old); 161 if (!new) 162 return -ENOMEM; 163 164 /* table is already unmerged */ 165 if (new == old) 166 return 0; 167 168 /* replace merged table with clean table */ 169 fib_replace_table(net, old, new); 170 fib_free_table(old); 171 172 /* attempt to fetch main table if it has been allocated */ 173 main_table = fib_get_table(net, RT_TABLE_MAIN); 174 if (!main_table) 175 return 0; 176 177 /* flush local entries from main table */ 178 fib_table_flush_external(main_table); 179 180 return 0; 181 } 182 183 void fib_flush(struct net *net) 184 { 185 int flushed = 0; 186 unsigned int h; 187 188 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 189 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 190 struct hlist_node *tmp; 191 struct fib_table *tb; 192 193 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) 194 flushed += fib_table_flush(net, tb, false); 195 } 196 197 if (flushed) 198 rt_cache_flush(net); 199 } 200 201 /* 202 * Find address type as if only "dev" was present in the system. If 203 * on_dev is NULL then all interfaces are taken into consideration. 204 */ 205 static inline unsigned int __inet_dev_addr_type(struct net *net, 206 const struct net_device *dev, 207 __be32 addr, u32 tb_id) 208 { 209 struct flowi4 fl4 = { .daddr = addr }; 210 struct fib_result res; 211 unsigned int ret = RTN_BROADCAST; 212 struct fib_table *table; 213 214 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr)) 215 return RTN_BROADCAST; 216 if (ipv4_is_multicast(addr)) 217 return RTN_MULTICAST; 218 219 rcu_read_lock(); 220 221 table = fib_get_table(net, tb_id); 222 if (table) { 223 ret = RTN_UNICAST; 224 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) { 225 struct fib_nh_common *nhc = fib_info_nhc(res.fi, 0); 226 227 if (!dev || dev == nhc->nhc_dev) 228 ret = res.type; 229 } 230 } 231 232 rcu_read_unlock(); 233 return ret; 234 } 235 236 unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id) 237 { 238 return __inet_dev_addr_type(net, NULL, addr, tb_id); 239 } 240 EXPORT_SYMBOL(inet_addr_type_table); 241 242 unsigned int inet_addr_type(struct net *net, __be32 addr) 243 { 244 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL); 245 } 246 EXPORT_SYMBOL(inet_addr_type); 247 248 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, 249 __be32 addr) 250 { 251 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL; 252 253 return __inet_dev_addr_type(net, dev, addr, rt_table); 254 } 255 EXPORT_SYMBOL(inet_dev_addr_type); 256 257 /* inet_addr_type with dev == NULL but using the table from a dev 258 * if one is associated 259 */ 260 unsigned int inet_addr_type_dev_table(struct net *net, 261 const struct net_device *dev, 262 __be32 addr) 263 { 264 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL; 265 266 return __inet_dev_addr_type(net, NULL, addr, rt_table); 267 } 268 EXPORT_SYMBOL(inet_addr_type_dev_table); 269 270 __be32 fib_compute_spec_dst(struct sk_buff *skb) 271 { 272 struct net_device *dev = skb->dev; 273 struct in_device *in_dev; 274 struct fib_result res; 275 struct rtable *rt; 276 struct net *net; 277 int scope; 278 279 rt = skb_rtable(skb); 280 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) == 281 RTCF_LOCAL) 282 return ip_hdr(skb)->daddr; 283 284 in_dev = __in_dev_get_rcu(dev); 285 286 net = dev_net(dev); 287 288 scope = RT_SCOPE_UNIVERSE; 289 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) { 290 bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev); 291 struct flowi4 fl4 = { 292 .flowi4_iif = LOOPBACK_IFINDEX, 293 .flowi4_oif = l3mdev_master_ifindex_rcu(dev), 294 .daddr = ip_hdr(skb)->saddr, 295 .flowi4_tos = RT_TOS(ip_hdr(skb)->tos), 296 .flowi4_scope = scope, 297 .flowi4_mark = vmark ? skb->mark : 0, 298 }; 299 if (!fib_lookup(net, &fl4, &res, 0)) 300 return fib_result_prefsrc(net, &res); 301 } else { 302 scope = RT_SCOPE_LINK; 303 } 304 305 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope); 306 } 307 308 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev) 309 { 310 bool dev_match = false; 311 #ifdef CONFIG_IP_ROUTE_MULTIPATH 312 int ret; 313 314 for (ret = 0; ret < fib_info_num_path(fi); ret++) { 315 const struct fib_nh_common *nhc = fib_info_nhc(fi, ret); 316 317 if (nhc->nhc_dev == dev) { 318 dev_match = true; 319 break; 320 } else if (l3mdev_master_ifindex_rcu(nhc->nhc_dev) == dev->ifindex) { 321 dev_match = true; 322 break; 323 } 324 } 325 #else 326 if (fib_info_nhc(fi, 0)->nhc_dev == dev) 327 dev_match = true; 328 #endif 329 330 return dev_match; 331 } 332 EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev); 333 334 /* Given (packet source, input interface) and optional (dst, oif, tos): 335 * - (main) check, that source is valid i.e. not broadcast or our local 336 * address. 337 * - figure out what "logical" interface this packet arrived 338 * and calculate "specific destination" address. 339 * - check, that packet arrived from expected physical interface. 340 * called with rcu_read_lock() 341 */ 342 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 343 u8 tos, int oif, struct net_device *dev, 344 int rpf, struct in_device *idev, u32 *itag) 345 { 346 struct net *net = dev_net(dev); 347 struct flow_keys flkeys; 348 int ret, no_addr; 349 struct fib_result res; 350 struct flowi4 fl4; 351 bool dev_match; 352 353 fl4.flowi4_oif = 0; 354 fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev); 355 if (!fl4.flowi4_iif) 356 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX; 357 fl4.daddr = src; 358 fl4.saddr = dst; 359 fl4.flowi4_tos = tos; 360 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 361 fl4.flowi4_tun_key.tun_id = 0; 362 fl4.flowi4_flags = 0; 363 fl4.flowi4_uid = sock_net_uid(net, NULL); 364 365 no_addr = idev->ifa_list == NULL; 366 367 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0; 368 if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) { 369 fl4.flowi4_proto = 0; 370 fl4.fl4_sport = 0; 371 fl4.fl4_dport = 0; 372 } 373 374 if (fib_lookup(net, &fl4, &res, 0)) 375 goto last_resort; 376 if (res.type != RTN_UNICAST && 377 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev))) 378 goto e_inval; 379 fib_combine_itag(itag, &res); 380 381 dev_match = fib_info_nh_uses_dev(res.fi, dev); 382 /* This is not common, loopback packets retain skb_dst so normally they 383 * would not even hit this slow path. 384 */ 385 dev_match = dev_match || (res.type == RTN_LOCAL && 386 dev == net->loopback_dev); 387 if (dev_match) { 388 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; 389 return ret; 390 } 391 if (no_addr) 392 goto last_resort; 393 if (rpf == 1) 394 goto e_rpf; 395 fl4.flowi4_oif = dev->ifindex; 396 397 ret = 0; 398 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) { 399 if (res.type == RTN_UNICAST) 400 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; 401 } 402 return ret; 403 404 last_resort: 405 if (rpf) 406 goto e_rpf; 407 *itag = 0; 408 return 0; 409 410 e_inval: 411 return -EINVAL; 412 e_rpf: 413 return -EXDEV; 414 } 415 416 /* Ignore rp_filter for packets protected by IPsec. */ 417 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 418 u8 tos, int oif, struct net_device *dev, 419 struct in_device *idev, u32 *itag) 420 { 421 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev); 422 struct net *net = dev_net(dev); 423 424 if (!r && !fib_num_tclassid_users(net) && 425 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) { 426 if (IN_DEV_ACCEPT_LOCAL(idev)) 427 goto ok; 428 /* with custom local routes in place, checking local addresses 429 * only will be too optimistic, with custom rules, checking 430 * local addresses only can be too strict, e.g. due to vrf 431 */ 432 if (net->ipv4.fib_has_custom_local_routes || 433 fib4_has_custom_rules(net)) 434 goto full_check; 435 if (inet_lookup_ifaddr_rcu(net, src)) 436 return -EINVAL; 437 438 ok: 439 *itag = 0; 440 return 0; 441 } 442 443 full_check: 444 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag); 445 } 446 447 static inline __be32 sk_extract_addr(struct sockaddr *addr) 448 { 449 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 450 } 451 452 static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 453 { 454 struct nlattr *nla; 455 456 nla = (struct nlattr *) ((char *) mx + len); 457 nla->nla_type = type; 458 nla->nla_len = nla_attr_size(4); 459 *(u32 *) nla_data(nla) = value; 460 461 return len + nla_total_size(4); 462 } 463 464 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 465 struct fib_config *cfg) 466 { 467 __be32 addr; 468 int plen; 469 470 memset(cfg, 0, sizeof(*cfg)); 471 cfg->fc_nlinfo.nl_net = net; 472 473 if (rt->rt_dst.sa_family != AF_INET) 474 return -EAFNOSUPPORT; 475 476 /* 477 * Check mask for validity: 478 * a) it must be contiguous. 479 * b) destination must have all host bits clear. 480 * c) if application forgot to set correct family (AF_INET), 481 * reject request unless it is absolutely clear i.e. 482 * both family and mask are zero. 483 */ 484 plen = 32; 485 addr = sk_extract_addr(&rt->rt_dst); 486 if (!(rt->rt_flags & RTF_HOST)) { 487 __be32 mask = sk_extract_addr(&rt->rt_genmask); 488 489 if (rt->rt_genmask.sa_family != AF_INET) { 490 if (mask || rt->rt_genmask.sa_family) 491 return -EAFNOSUPPORT; 492 } 493 494 if (bad_mask(mask, addr)) 495 return -EINVAL; 496 497 plen = inet_mask_len(mask); 498 } 499 500 cfg->fc_dst_len = plen; 501 cfg->fc_dst = addr; 502 503 if (cmd != SIOCDELRT) { 504 cfg->fc_nlflags = NLM_F_CREATE; 505 cfg->fc_protocol = RTPROT_BOOT; 506 } 507 508 if (rt->rt_metric) 509 cfg->fc_priority = rt->rt_metric - 1; 510 511 if (rt->rt_flags & RTF_REJECT) { 512 cfg->fc_scope = RT_SCOPE_HOST; 513 cfg->fc_type = RTN_UNREACHABLE; 514 return 0; 515 } 516 517 cfg->fc_scope = RT_SCOPE_NOWHERE; 518 cfg->fc_type = RTN_UNICAST; 519 520 if (rt->rt_dev) { 521 char *colon; 522 struct net_device *dev; 523 char devname[IFNAMSIZ]; 524 525 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 526 return -EFAULT; 527 528 devname[IFNAMSIZ-1] = 0; 529 colon = strchr(devname, ':'); 530 if (colon) 531 *colon = 0; 532 dev = __dev_get_by_name(net, devname); 533 if (!dev) 534 return -ENODEV; 535 cfg->fc_oif = dev->ifindex; 536 cfg->fc_table = l3mdev_fib_table(dev); 537 if (colon) { 538 const struct in_ifaddr *ifa; 539 struct in_device *in_dev; 540 541 in_dev = __in_dev_get_rtnl(dev); 542 if (!in_dev) 543 return -ENODEV; 544 545 *colon = ':'; 546 547 rcu_read_lock(); 548 in_dev_for_each_ifa_rcu(ifa, in_dev) { 549 if (strcmp(ifa->ifa_label, devname) == 0) 550 break; 551 } 552 rcu_read_unlock(); 553 554 if (!ifa) 555 return -ENODEV; 556 cfg->fc_prefsrc = ifa->ifa_local; 557 } 558 } 559 560 addr = sk_extract_addr(&rt->rt_gateway); 561 if (rt->rt_gateway.sa_family == AF_INET && addr) { 562 unsigned int addr_type; 563 564 cfg->fc_gw4 = addr; 565 cfg->fc_gw_family = AF_INET; 566 addr_type = inet_addr_type_table(net, addr, cfg->fc_table); 567 if (rt->rt_flags & RTF_GATEWAY && 568 addr_type == RTN_UNICAST) 569 cfg->fc_scope = RT_SCOPE_UNIVERSE; 570 } 571 572 if (cmd == SIOCDELRT) 573 return 0; 574 575 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family) 576 return -EINVAL; 577 578 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 579 cfg->fc_scope = RT_SCOPE_LINK; 580 581 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 582 struct nlattr *mx; 583 int len = 0; 584 585 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL); 586 if (!mx) 587 return -ENOMEM; 588 589 if (rt->rt_flags & RTF_MTU) 590 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 591 592 if (rt->rt_flags & RTF_WINDOW) 593 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 594 595 if (rt->rt_flags & RTF_IRTT) 596 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 597 598 cfg->fc_mx = mx; 599 cfg->fc_mx_len = len; 600 } 601 602 return 0; 603 } 604 605 /* 606 * Handle IP routing ioctl calls. 607 * These are used to manipulate the routing tables 608 */ 609 int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt) 610 { 611 struct fib_config cfg; 612 int err; 613 614 switch (cmd) { 615 case SIOCADDRT: /* Add a route */ 616 case SIOCDELRT: /* Delete a route */ 617 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 618 return -EPERM; 619 620 rtnl_lock(); 621 err = rtentry_to_fib_config(net, cmd, rt, &cfg); 622 if (err == 0) { 623 struct fib_table *tb; 624 625 if (cmd == SIOCDELRT) { 626 tb = fib_get_table(net, cfg.fc_table); 627 if (tb) 628 err = fib_table_delete(net, tb, &cfg, 629 NULL); 630 else 631 err = -ESRCH; 632 } else { 633 tb = fib_new_table(net, cfg.fc_table); 634 if (tb) 635 err = fib_table_insert(net, tb, 636 &cfg, NULL); 637 else 638 err = -ENOBUFS; 639 } 640 641 /* allocated by rtentry_to_fib_config() */ 642 kfree(cfg.fc_mx); 643 } 644 rtnl_unlock(); 645 return err; 646 } 647 return -EINVAL; 648 } 649 650 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 651 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 }, 652 [RTA_DST] = { .type = NLA_U32 }, 653 [RTA_SRC] = { .type = NLA_U32 }, 654 [RTA_IIF] = { .type = NLA_U32 }, 655 [RTA_OIF] = { .type = NLA_U32 }, 656 [RTA_GATEWAY] = { .type = NLA_U32 }, 657 [RTA_PRIORITY] = { .type = NLA_U32 }, 658 [RTA_PREFSRC] = { .type = NLA_U32 }, 659 [RTA_METRICS] = { .type = NLA_NESTED }, 660 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 661 [RTA_FLOW] = { .type = NLA_U32 }, 662 [RTA_ENCAP_TYPE] = { .type = NLA_U16 }, 663 [RTA_ENCAP] = { .type = NLA_NESTED }, 664 [RTA_UID] = { .type = NLA_U32 }, 665 [RTA_MARK] = { .type = NLA_U32 }, 666 [RTA_TABLE] = { .type = NLA_U32 }, 667 [RTA_IP_PROTO] = { .type = NLA_U8 }, 668 [RTA_SPORT] = { .type = NLA_U16 }, 669 [RTA_DPORT] = { .type = NLA_U16 }, 670 [RTA_NH_ID] = { .type = NLA_U32 }, 671 }; 672 673 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, 674 struct netlink_ext_ack *extack) 675 { 676 struct rtvia *via; 677 int alen; 678 679 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) { 680 NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA"); 681 return -EINVAL; 682 } 683 684 via = nla_data(nla); 685 alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr); 686 687 switch (via->rtvia_family) { 688 case AF_INET: 689 if (alen != sizeof(__be32)) { 690 NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA"); 691 return -EINVAL; 692 } 693 cfg->fc_gw_family = AF_INET; 694 cfg->fc_gw4 = *((__be32 *)via->rtvia_addr); 695 break; 696 case AF_INET6: 697 #ifdef CONFIG_IPV6 698 if (alen != sizeof(struct in6_addr)) { 699 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA"); 700 return -EINVAL; 701 } 702 cfg->fc_gw_family = AF_INET6; 703 cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr); 704 #else 705 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel"); 706 return -EINVAL; 707 #endif 708 break; 709 default: 710 NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA"); 711 return -EINVAL; 712 } 713 714 return 0; 715 } 716 717 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 718 struct nlmsghdr *nlh, struct fib_config *cfg, 719 struct netlink_ext_ack *extack) 720 { 721 bool has_gw = false, has_via = false; 722 struct nlattr *attr; 723 int err, remaining; 724 struct rtmsg *rtm; 725 726 err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX, 727 rtm_ipv4_policy, extack); 728 if (err < 0) 729 goto errout; 730 731 memset(cfg, 0, sizeof(*cfg)); 732 733 rtm = nlmsg_data(nlh); 734 cfg->fc_dst_len = rtm->rtm_dst_len; 735 cfg->fc_tos = rtm->rtm_tos; 736 cfg->fc_table = rtm->rtm_table; 737 cfg->fc_protocol = rtm->rtm_protocol; 738 cfg->fc_scope = rtm->rtm_scope; 739 cfg->fc_type = rtm->rtm_type; 740 cfg->fc_flags = rtm->rtm_flags; 741 cfg->fc_nlflags = nlh->nlmsg_flags; 742 743 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid; 744 cfg->fc_nlinfo.nlh = nlh; 745 cfg->fc_nlinfo.nl_net = net; 746 747 if (cfg->fc_type > RTN_MAX) { 748 NL_SET_ERR_MSG(extack, "Invalid route type"); 749 err = -EINVAL; 750 goto errout; 751 } 752 753 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 754 switch (nla_type(attr)) { 755 case RTA_DST: 756 cfg->fc_dst = nla_get_be32(attr); 757 break; 758 case RTA_OIF: 759 cfg->fc_oif = nla_get_u32(attr); 760 break; 761 case RTA_GATEWAY: 762 has_gw = true; 763 cfg->fc_gw4 = nla_get_be32(attr); 764 if (cfg->fc_gw4) 765 cfg->fc_gw_family = AF_INET; 766 break; 767 case RTA_VIA: 768 has_via = true; 769 err = fib_gw_from_via(cfg, attr, extack); 770 if (err) 771 goto errout; 772 break; 773 case RTA_PRIORITY: 774 cfg->fc_priority = nla_get_u32(attr); 775 break; 776 case RTA_PREFSRC: 777 cfg->fc_prefsrc = nla_get_be32(attr); 778 break; 779 case RTA_METRICS: 780 cfg->fc_mx = nla_data(attr); 781 cfg->fc_mx_len = nla_len(attr); 782 break; 783 case RTA_MULTIPATH: 784 err = lwtunnel_valid_encap_type_attr(nla_data(attr), 785 nla_len(attr), 786 extack); 787 if (err < 0) 788 goto errout; 789 cfg->fc_mp = nla_data(attr); 790 cfg->fc_mp_len = nla_len(attr); 791 break; 792 case RTA_FLOW: 793 cfg->fc_flow = nla_get_u32(attr); 794 break; 795 case RTA_TABLE: 796 cfg->fc_table = nla_get_u32(attr); 797 break; 798 case RTA_ENCAP: 799 cfg->fc_encap = attr; 800 break; 801 case RTA_ENCAP_TYPE: 802 cfg->fc_encap_type = nla_get_u16(attr); 803 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, 804 extack); 805 if (err < 0) 806 goto errout; 807 break; 808 case RTA_NH_ID: 809 cfg->fc_nh_id = nla_get_u32(attr); 810 break; 811 } 812 } 813 814 if (cfg->fc_nh_id) { 815 if (cfg->fc_oif || cfg->fc_gw_family || 816 cfg->fc_encap || cfg->fc_mp) { 817 NL_SET_ERR_MSG(extack, 818 "Nexthop specification and nexthop id are mutually exclusive"); 819 return -EINVAL; 820 } 821 } 822 823 if (has_gw && has_via) { 824 NL_SET_ERR_MSG(extack, 825 "Nexthop configuration can not contain both GATEWAY and VIA"); 826 goto errout; 827 } 828 829 return 0; 830 errout: 831 return err; 832 } 833 834 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, 835 struct netlink_ext_ack *extack) 836 { 837 struct net *net = sock_net(skb->sk); 838 struct fib_config cfg; 839 struct fib_table *tb; 840 int err; 841 842 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 843 if (err < 0) 844 goto errout; 845 846 if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) { 847 NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); 848 err = -EINVAL; 849 goto errout; 850 } 851 852 tb = fib_get_table(net, cfg.fc_table); 853 if (!tb) { 854 NL_SET_ERR_MSG(extack, "FIB table does not exist"); 855 err = -ESRCH; 856 goto errout; 857 } 858 859 err = fib_table_delete(net, tb, &cfg, extack); 860 errout: 861 return err; 862 } 863 864 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, 865 struct netlink_ext_ack *extack) 866 { 867 struct net *net = sock_net(skb->sk); 868 struct fib_config cfg; 869 struct fib_table *tb; 870 int err; 871 872 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 873 if (err < 0) 874 goto errout; 875 876 tb = fib_new_table(net, cfg.fc_table); 877 if (!tb) { 878 err = -ENOBUFS; 879 goto errout; 880 } 881 882 err = fib_table_insert(net, tb, &cfg, extack); 883 if (!err && cfg.fc_type == RTN_LOCAL) 884 net->ipv4.fib_has_custom_local_routes = true; 885 errout: 886 return err; 887 } 888 889 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 890 struct fib_dump_filter *filter, 891 struct netlink_callback *cb) 892 { 893 struct netlink_ext_ack *extack = cb->extack; 894 struct nlattr *tb[RTA_MAX + 1]; 895 struct rtmsg *rtm; 896 int err, i; 897 898 ASSERT_RTNL(); 899 900 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 901 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request"); 902 return -EINVAL; 903 } 904 905 rtm = nlmsg_data(nlh); 906 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos || 907 rtm->rtm_scope) { 908 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request"); 909 return -EINVAL; 910 } 911 912 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) { 913 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request"); 914 return -EINVAL; 915 } 916 if (rtm->rtm_flags & RTM_F_CLONED) 917 filter->dump_routes = false; 918 else 919 filter->dump_exceptions = false; 920 921 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 struct fib_dump_filter filter = { .dump_routes = true, 966 .dump_exceptions = true }; 967 const struct nlmsghdr *nlh = cb->nlh; 968 struct net *net = sock_net(skb->sk); 969 unsigned int h, s_h; 970 unsigned int e = 0, s_e; 971 struct fib_table *tb; 972 struct hlist_head *head; 973 int dumped = 0, err; 974 975 if (cb->strict_check) { 976 err = ip_valid_fib_dump_req(net, nlh, &filter, cb); 977 if (err < 0) 978 return err; 979 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 980 struct rtmsg *rtm = nlmsg_data(nlh); 981 982 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED); 983 } 984 985 /* ipv4 does not use prefix flag */ 986 if (filter.flags & RTM_F_PREFIX) 987 return skb->len; 988 989 if (filter.table_id) { 990 tb = fib_get_table(net, filter.table_id); 991 if (!tb) { 992 if (rtnl_msg_family(cb->nlh) != PF_INET) 993 return skb->len; 994 995 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist"); 996 return -ENOENT; 997 } 998 999 rcu_read_lock(); 1000 err = fib_table_dump(tb, skb, cb, &filter); 1001 rcu_read_unlock(); 1002 return skb->len ? : err; 1003 } 1004 1005 s_h = cb->args[0]; 1006 s_e = cb->args[1]; 1007 1008 rcu_read_lock(); 1009 1010 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 1011 e = 0; 1012 head = &net->ipv4.fib_table_hash[h]; 1013 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 1014 if (e < s_e) 1015 goto next; 1016 if (dumped) 1017 memset(&cb->args[2], 0, sizeof(cb->args) - 1018 2 * sizeof(cb->args[0])); 1019 err = fib_table_dump(tb, skb, cb, &filter); 1020 if (err < 0) { 1021 if (likely(skb->len)) 1022 goto out; 1023 1024 goto out_err; 1025 } 1026 dumped = 1; 1027 next: 1028 e++; 1029 } 1030 } 1031 out: 1032 err = skb->len; 1033 out_err: 1034 rcu_read_unlock(); 1035 1036 cb->args[1] = e; 1037 cb->args[0] = h; 1038 1039 return err; 1040 } 1041 1042 /* Prepare and feed intra-kernel routing request. 1043 * Really, it should be netlink message, but :-( netlink 1044 * can be not configured, so that we feed it directly 1045 * to fib engine. It is legal, because all events occur 1046 * only when netlink is already locked. 1047 */ 1048 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, 1049 struct in_ifaddr *ifa, u32 rt_priority) 1050 { 1051 struct net *net = dev_net(ifa->ifa_dev->dev); 1052 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev); 1053 struct fib_table *tb; 1054 struct fib_config cfg = { 1055 .fc_protocol = RTPROT_KERNEL, 1056 .fc_type = type, 1057 .fc_dst = dst, 1058 .fc_dst_len = dst_len, 1059 .fc_priority = rt_priority, 1060 .fc_prefsrc = ifa->ifa_local, 1061 .fc_oif = ifa->ifa_dev->dev->ifindex, 1062 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 1063 .fc_nlinfo = { 1064 .nl_net = net, 1065 }, 1066 }; 1067 1068 if (!tb_id) 1069 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL; 1070 1071 tb = fib_new_table(net, tb_id); 1072 if (!tb) 1073 return; 1074 1075 cfg.fc_table = tb->tb_id; 1076 1077 if (type != RTN_LOCAL) 1078 cfg.fc_scope = RT_SCOPE_LINK; 1079 else 1080 cfg.fc_scope = RT_SCOPE_HOST; 1081 1082 if (cmd == RTM_NEWROUTE) 1083 fib_table_insert(net, tb, &cfg, NULL); 1084 else 1085 fib_table_delete(net, tb, &cfg, NULL); 1086 } 1087 1088 void fib_add_ifaddr(struct in_ifaddr *ifa) 1089 { 1090 struct in_device *in_dev = ifa->ifa_dev; 1091 struct net_device *dev = in_dev->dev; 1092 struct in_ifaddr *prim = ifa; 1093 __be32 mask = ifa->ifa_mask; 1094 __be32 addr = ifa->ifa_local; 1095 __be32 prefix = ifa->ifa_address & mask; 1096 1097 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1098 prim = inet_ifa_byprefix(in_dev, prefix, mask); 1099 if (!prim) { 1100 pr_warn("%s: bug: prim == NULL\n", __func__); 1101 return; 1102 } 1103 } 1104 1105 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0); 1106 1107 if (!(dev->flags & IFF_UP)) 1108 return; 1109 1110 /* Add broadcast address, if it is explicitly assigned. */ 1111 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 1112 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1113 prim, 0); 1114 1115 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 1116 (prefix != addr || ifa->ifa_prefixlen < 32)) { 1117 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1118 fib_magic(RTM_NEWROUTE, 1119 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1120 prefix, ifa->ifa_prefixlen, prim, 1121 ifa->ifa_rt_priority); 1122 1123 /* Add network specific broadcasts, when it takes a sense */ 1124 if (ifa->ifa_prefixlen < 31) { 1125 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, 1126 prim, 0); 1127 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 1128 32, prim, 0); 1129 } 1130 } 1131 } 1132 1133 void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric) 1134 { 1135 __be32 prefix = ifa->ifa_address & ifa->ifa_mask; 1136 struct in_device *in_dev = ifa->ifa_dev; 1137 struct net_device *dev = in_dev->dev; 1138 1139 if (!(dev->flags & IFF_UP) || 1140 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) || 1141 ipv4_is_zeronet(prefix) || 1142 (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32)) 1143 return; 1144 1145 /* add the new */ 1146 fib_magic(RTM_NEWROUTE, 1147 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1148 prefix, ifa->ifa_prefixlen, ifa, new_metric); 1149 1150 /* delete the old */ 1151 fib_magic(RTM_DELROUTE, 1152 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1153 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority); 1154 } 1155 1156 /* Delete primary or secondary address. 1157 * Optionally, on secondary address promotion consider the addresses 1158 * from subnet iprim as deleted, even if they are in device list. 1159 * In this case the secondary ifa can be in device list. 1160 */ 1161 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 1162 { 1163 struct in_device *in_dev = ifa->ifa_dev; 1164 struct net_device *dev = in_dev->dev; 1165 struct in_ifaddr *ifa1; 1166 struct in_ifaddr *prim = ifa, *prim1 = NULL; 1167 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 1168 __be32 any = ifa->ifa_address & ifa->ifa_mask; 1169 #define LOCAL_OK 1 1170 #define BRD_OK 2 1171 #define BRD0_OK 4 1172 #define BRD1_OK 8 1173 unsigned int ok = 0; 1174 int subnet = 0; /* Primary network */ 1175 int gone = 1; /* Address is missing */ 1176 int same_prefsrc = 0; /* Another primary with same IP */ 1177 1178 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1179 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 1180 if (!prim) { 1181 /* if the device has been deleted, we don't perform 1182 * address promotion 1183 */ 1184 if (!in_dev->dead) 1185 pr_warn("%s: bug: prim == NULL\n", __func__); 1186 return; 1187 } 1188 if (iprim && iprim != prim) { 1189 pr_warn("%s: bug: iprim != prim\n", __func__); 1190 return; 1191 } 1192 } else if (!ipv4_is_zeronet(any) && 1193 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 1194 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1195 fib_magic(RTM_DELROUTE, 1196 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1197 any, ifa->ifa_prefixlen, prim, 0); 1198 subnet = 1; 1199 } 1200 1201 if (in_dev->dead) 1202 goto no_promotions; 1203 1204 /* Deletion is more complicated than add. 1205 * We should take care of not to delete too much :-) 1206 * 1207 * Scan address list to be sure that addresses are really gone. 1208 */ 1209 rcu_read_lock(); 1210 in_dev_for_each_ifa_rcu(ifa1, in_dev) { 1211 if (ifa1 == ifa) { 1212 /* promotion, keep the IP */ 1213 gone = 0; 1214 continue; 1215 } 1216 /* Ignore IFAs from our subnet */ 1217 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 1218 inet_ifa_match(ifa1->ifa_address, iprim)) 1219 continue; 1220 1221 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 1222 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 1223 /* Another address from our subnet? */ 1224 if (ifa1->ifa_mask == prim->ifa_mask && 1225 inet_ifa_match(ifa1->ifa_address, prim)) 1226 prim1 = prim; 1227 else { 1228 /* We reached the secondaries, so 1229 * same_prefsrc should be determined. 1230 */ 1231 if (!same_prefsrc) 1232 continue; 1233 /* Search new prim1 if ifa1 is not 1234 * using the current prim1 1235 */ 1236 if (!prim1 || 1237 ifa1->ifa_mask != prim1->ifa_mask || 1238 !inet_ifa_match(ifa1->ifa_address, prim1)) 1239 prim1 = inet_ifa_byprefix(in_dev, 1240 ifa1->ifa_address, 1241 ifa1->ifa_mask); 1242 if (!prim1) 1243 continue; 1244 if (prim1->ifa_local != prim->ifa_local) 1245 continue; 1246 } 1247 } else { 1248 if (prim->ifa_local != ifa1->ifa_local) 1249 continue; 1250 prim1 = ifa1; 1251 if (prim != prim1) 1252 same_prefsrc = 1; 1253 } 1254 if (ifa->ifa_local == ifa1->ifa_local) 1255 ok |= LOCAL_OK; 1256 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 1257 ok |= BRD_OK; 1258 if (brd == ifa1->ifa_broadcast) 1259 ok |= BRD1_OK; 1260 if (any == ifa1->ifa_broadcast) 1261 ok |= BRD0_OK; 1262 /* primary has network specific broadcasts */ 1263 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 1264 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 1265 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 1266 1267 if (!ipv4_is_zeronet(any1)) { 1268 if (ifa->ifa_broadcast == brd1 || 1269 ifa->ifa_broadcast == any1) 1270 ok |= BRD_OK; 1271 if (brd == brd1 || brd == any1) 1272 ok |= BRD1_OK; 1273 if (any == brd1 || any == any1) 1274 ok |= BRD0_OK; 1275 } 1276 } 1277 } 1278 rcu_read_unlock(); 1279 1280 no_promotions: 1281 if (!(ok & BRD_OK)) 1282 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1283 prim, 0); 1284 if (subnet && ifa->ifa_prefixlen < 31) { 1285 if (!(ok & BRD1_OK)) 1286 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, 1287 prim, 0); 1288 if (!(ok & BRD0_OK)) 1289 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, 1290 prim, 0); 1291 } 1292 if (!(ok & LOCAL_OK)) { 1293 unsigned int addr_type; 1294 1295 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0); 1296 1297 /* Check, that this local address finally disappeared. */ 1298 addr_type = inet_addr_type_dev_table(dev_net(dev), dev, 1299 ifa->ifa_local); 1300 if (gone && addr_type != RTN_LOCAL) { 1301 /* And the last, but not the least thing. 1302 * We must flush stray FIB entries. 1303 * 1304 * First of all, we scan fib_info list searching 1305 * for stray nexthop entries, then ignite fib_flush. 1306 */ 1307 if (fib_sync_down_addr(dev, ifa->ifa_local)) 1308 fib_flush(dev_net(dev)); 1309 } 1310 } 1311 #undef LOCAL_OK 1312 #undef BRD_OK 1313 #undef BRD0_OK 1314 #undef BRD1_OK 1315 } 1316 1317 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn) 1318 { 1319 1320 struct fib_result res; 1321 struct flowi4 fl4 = { 1322 .flowi4_mark = frn->fl_mark, 1323 .daddr = frn->fl_addr, 1324 .flowi4_tos = frn->fl_tos, 1325 .flowi4_scope = frn->fl_scope, 1326 }; 1327 struct fib_table *tb; 1328 1329 rcu_read_lock(); 1330 1331 tb = fib_get_table(net, frn->tb_id_in); 1332 1333 frn->err = -ENOENT; 1334 if (tb) { 1335 local_bh_disable(); 1336 1337 frn->tb_id = tb->tb_id; 1338 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 1339 1340 if (!frn->err) { 1341 frn->prefixlen = res.prefixlen; 1342 frn->nh_sel = res.nh_sel; 1343 frn->type = res.type; 1344 frn->scope = res.scope; 1345 } 1346 local_bh_enable(); 1347 } 1348 1349 rcu_read_unlock(); 1350 } 1351 1352 static void nl_fib_input(struct sk_buff *skb) 1353 { 1354 struct net *net; 1355 struct fib_result_nl *frn; 1356 struct nlmsghdr *nlh; 1357 u32 portid; 1358 1359 net = sock_net(skb->sk); 1360 nlh = nlmsg_hdr(skb); 1361 if (skb->len < nlmsg_total_size(sizeof(*frn)) || 1362 skb->len < nlh->nlmsg_len || 1363 nlmsg_len(nlh) < sizeof(*frn)) 1364 return; 1365 1366 skb = netlink_skb_clone(skb, GFP_KERNEL); 1367 if (!skb) 1368 return; 1369 nlh = nlmsg_hdr(skb); 1370 1371 frn = (struct fib_result_nl *) nlmsg_data(nlh); 1372 nl_fib_lookup(net, frn); 1373 1374 portid = NETLINK_CB(skb).portid; /* netlink portid */ 1375 NETLINK_CB(skb).portid = 0; /* from kernel */ 1376 NETLINK_CB(skb).dst_group = 0; /* unicast */ 1377 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT); 1378 } 1379 1380 static int __net_init nl_fib_lookup_init(struct net *net) 1381 { 1382 struct sock *sk; 1383 struct netlink_kernel_cfg cfg = { 1384 .input = nl_fib_input, 1385 }; 1386 1387 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg); 1388 if (!sk) 1389 return -EAFNOSUPPORT; 1390 net->ipv4.fibnl = sk; 1391 return 0; 1392 } 1393 1394 static void nl_fib_lookup_exit(struct net *net) 1395 { 1396 netlink_kernel_release(net->ipv4.fibnl); 1397 net->ipv4.fibnl = NULL; 1398 } 1399 1400 static void fib_disable_ip(struct net_device *dev, unsigned long event, 1401 bool force) 1402 { 1403 if (fib_sync_down_dev(dev, event, force)) 1404 fib_flush(dev_net(dev)); 1405 else 1406 rt_cache_flush(dev_net(dev)); 1407 arp_ifdown(dev); 1408 } 1409 1410 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 1411 { 1412 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 1413 struct net_device *dev = ifa->ifa_dev->dev; 1414 struct net *net = dev_net(dev); 1415 1416 switch (event) { 1417 case NETDEV_UP: 1418 fib_add_ifaddr(ifa); 1419 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1420 fib_sync_up(dev, RTNH_F_DEAD); 1421 #endif 1422 atomic_inc(&net->ipv4.dev_addr_genid); 1423 rt_cache_flush(dev_net(dev)); 1424 break; 1425 case NETDEV_DOWN: 1426 fib_del_ifaddr(ifa, NULL); 1427 atomic_inc(&net->ipv4.dev_addr_genid); 1428 if (!ifa->ifa_dev->ifa_list) { 1429 /* Last address was deleted from this interface. 1430 * Disable IP. 1431 */ 1432 fib_disable_ip(dev, event, true); 1433 } else { 1434 rt_cache_flush(dev_net(dev)); 1435 } 1436 break; 1437 } 1438 return NOTIFY_DONE; 1439 } 1440 1441 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1442 { 1443 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1444 struct netdev_notifier_changeupper_info *upper_info = ptr; 1445 struct netdev_notifier_info_ext *info_ext = ptr; 1446 struct in_device *in_dev; 1447 struct net *net = dev_net(dev); 1448 struct in_ifaddr *ifa; 1449 unsigned int flags; 1450 1451 if (event == NETDEV_UNREGISTER) { 1452 fib_disable_ip(dev, event, true); 1453 rt_flush_dev(dev); 1454 return NOTIFY_DONE; 1455 } 1456 1457 in_dev = __in_dev_get_rtnl(dev); 1458 if (!in_dev) 1459 return NOTIFY_DONE; 1460 1461 switch (event) { 1462 case NETDEV_UP: 1463 in_dev_for_each_ifa_rtnl(ifa, in_dev) { 1464 fib_add_ifaddr(ifa); 1465 } 1466 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1467 fib_sync_up(dev, RTNH_F_DEAD); 1468 #endif 1469 atomic_inc(&net->ipv4.dev_addr_genid); 1470 rt_cache_flush(net); 1471 break; 1472 case NETDEV_DOWN: 1473 fib_disable_ip(dev, event, false); 1474 break; 1475 case NETDEV_CHANGE: 1476 flags = dev_get_flags(dev); 1477 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1478 fib_sync_up(dev, RTNH_F_LINKDOWN); 1479 else 1480 fib_sync_down_dev(dev, event, false); 1481 rt_cache_flush(net); 1482 break; 1483 case NETDEV_CHANGEMTU: 1484 fib_sync_mtu(dev, info_ext->ext.mtu); 1485 rt_cache_flush(net); 1486 break; 1487 case NETDEV_CHANGEUPPER: 1488 upper_info = ptr; 1489 /* flush all routes if dev is linked to or unlinked from 1490 * an L3 master device (e.g., VRF) 1491 */ 1492 if (upper_info->upper_dev && 1493 netif_is_l3_master(upper_info->upper_dev)) 1494 fib_disable_ip(dev, NETDEV_DOWN, true); 1495 break; 1496 } 1497 return NOTIFY_DONE; 1498 } 1499 1500 static struct notifier_block fib_inetaddr_notifier = { 1501 .notifier_call = fib_inetaddr_event, 1502 }; 1503 1504 static struct notifier_block fib_netdev_notifier = { 1505 .notifier_call = fib_netdev_event, 1506 }; 1507 1508 static int __net_init ip_fib_net_init(struct net *net) 1509 { 1510 int err; 1511 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1512 1513 err = fib4_notifier_init(net); 1514 if (err) 1515 return err; 1516 1517 /* Avoid false sharing : Use at least a full cache line */ 1518 size = max_t(size_t, size, L1_CACHE_BYTES); 1519 1520 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1521 if (!net->ipv4.fib_table_hash) { 1522 err = -ENOMEM; 1523 goto err_table_hash_alloc; 1524 } 1525 1526 err = fib4_rules_init(net); 1527 if (err < 0) 1528 goto err_rules_init; 1529 return 0; 1530 1531 err_rules_init: 1532 kfree(net->ipv4.fib_table_hash); 1533 err_table_hash_alloc: 1534 fib4_notifier_exit(net); 1535 return err; 1536 } 1537 1538 static void ip_fib_net_exit(struct net *net) 1539 { 1540 int i; 1541 1542 rtnl_lock(); 1543 #ifdef CONFIG_IP_MULTIPLE_TABLES 1544 RCU_INIT_POINTER(net->ipv4.fib_main, NULL); 1545 RCU_INIT_POINTER(net->ipv4.fib_default, NULL); 1546 #endif 1547 /* Destroy the tables in reverse order to guarantee that the 1548 * local table, ID 255, is destroyed before the main table, ID 1549 * 254. This is necessary as the local table may contain 1550 * references to data contained in the main table. 1551 */ 1552 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) { 1553 struct hlist_head *head = &net->ipv4.fib_table_hash[i]; 1554 struct hlist_node *tmp; 1555 struct fib_table *tb; 1556 1557 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) { 1558 hlist_del(&tb->tb_hlist); 1559 fib_table_flush(net, tb, true); 1560 fib_free_table(tb); 1561 } 1562 } 1563 1564 #ifdef CONFIG_IP_MULTIPLE_TABLES 1565 fib4_rules_exit(net); 1566 #endif 1567 rtnl_unlock(); 1568 kfree(net->ipv4.fib_table_hash); 1569 fib4_notifier_exit(net); 1570 } 1571 1572 static int __net_init fib_net_init(struct net *net) 1573 { 1574 int error; 1575 1576 #ifdef CONFIG_IP_ROUTE_CLASSID 1577 net->ipv4.fib_num_tclassid_users = 0; 1578 #endif 1579 error = ip_fib_net_init(net); 1580 if (error < 0) 1581 goto out; 1582 error = nl_fib_lookup_init(net); 1583 if (error < 0) 1584 goto out_nlfl; 1585 error = fib_proc_init(net); 1586 if (error < 0) 1587 goto out_proc; 1588 out: 1589 return error; 1590 1591 out_proc: 1592 nl_fib_lookup_exit(net); 1593 out_nlfl: 1594 ip_fib_net_exit(net); 1595 goto out; 1596 } 1597 1598 static void __net_exit fib_net_exit(struct net *net) 1599 { 1600 fib_proc_exit(net); 1601 nl_fib_lookup_exit(net); 1602 ip_fib_net_exit(net); 1603 } 1604 1605 static struct pernet_operations fib_net_ops = { 1606 .init = fib_net_init, 1607 .exit = fib_net_exit, 1608 }; 1609 1610 void __init ip_fib_init(void) 1611 { 1612 fib_trie_init(); 1613 1614 register_pernet_subsys(&fib_net_ops); 1615 1616 register_netdevice_notifier(&fib_netdev_notifier); 1617 register_inetaddr_notifier(&fib_inetaddr_notifier); 1618 1619 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0); 1620 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0); 1621 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0); 1622 } 1623