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 /* This is not common, loopback packets retain skb_dst so normally they 392 * would not even hit this slow path. 393 */ 394 dev_match = dev_match || (res.type == RTN_LOCAL && 395 dev == net->loopback_dev); 396 if (dev_match) { 397 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; 398 return ret; 399 } 400 if (no_addr) 401 goto last_resort; 402 if (rpf == 1) 403 goto e_rpf; 404 fl4.flowi4_oif = dev->ifindex; 405 406 ret = 0; 407 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) { 408 if (res.type == RTN_UNICAST) 409 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; 410 } 411 return ret; 412 413 last_resort: 414 if (rpf) 415 goto e_rpf; 416 *itag = 0; 417 return 0; 418 419 e_inval: 420 return -EINVAL; 421 e_rpf: 422 return -EXDEV; 423 } 424 425 /* Ignore rp_filter for packets protected by IPsec. */ 426 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 427 u8 tos, int oif, struct net_device *dev, 428 struct in_device *idev, u32 *itag) 429 { 430 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev); 431 struct net *net = dev_net(dev); 432 433 if (!r && !fib_num_tclassid_users(net) && 434 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) { 435 if (IN_DEV_ACCEPT_LOCAL(idev)) 436 goto ok; 437 /* with custom local routes in place, checking local addresses 438 * only will be too optimistic, with custom rules, checking 439 * local addresses only can be too strict, e.g. due to vrf 440 */ 441 if (net->ipv4.fib_has_custom_local_routes || 442 fib4_has_custom_rules(net)) 443 goto full_check; 444 if (inet_lookup_ifaddr_rcu(net, src)) 445 return -EINVAL; 446 447 ok: 448 *itag = 0; 449 return 0; 450 } 451 452 full_check: 453 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag); 454 } 455 456 static inline __be32 sk_extract_addr(struct sockaddr *addr) 457 { 458 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 459 } 460 461 static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 462 { 463 struct nlattr *nla; 464 465 nla = (struct nlattr *) ((char *) mx + len); 466 nla->nla_type = type; 467 nla->nla_len = nla_attr_size(4); 468 *(u32 *) nla_data(nla) = value; 469 470 return len + nla_total_size(4); 471 } 472 473 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 474 struct fib_config *cfg) 475 { 476 __be32 addr; 477 int plen; 478 479 memset(cfg, 0, sizeof(*cfg)); 480 cfg->fc_nlinfo.nl_net = net; 481 482 if (rt->rt_dst.sa_family != AF_INET) 483 return -EAFNOSUPPORT; 484 485 /* 486 * Check mask for validity: 487 * a) it must be contiguous. 488 * b) destination must have all host bits clear. 489 * c) if application forgot to set correct family (AF_INET), 490 * reject request unless it is absolutely clear i.e. 491 * both family and mask are zero. 492 */ 493 plen = 32; 494 addr = sk_extract_addr(&rt->rt_dst); 495 if (!(rt->rt_flags & RTF_HOST)) { 496 __be32 mask = sk_extract_addr(&rt->rt_genmask); 497 498 if (rt->rt_genmask.sa_family != AF_INET) { 499 if (mask || rt->rt_genmask.sa_family) 500 return -EAFNOSUPPORT; 501 } 502 503 if (bad_mask(mask, addr)) 504 return -EINVAL; 505 506 plen = inet_mask_len(mask); 507 } 508 509 cfg->fc_dst_len = plen; 510 cfg->fc_dst = addr; 511 512 if (cmd != SIOCDELRT) { 513 cfg->fc_nlflags = NLM_F_CREATE; 514 cfg->fc_protocol = RTPROT_BOOT; 515 } 516 517 if (rt->rt_metric) 518 cfg->fc_priority = rt->rt_metric - 1; 519 520 if (rt->rt_flags & RTF_REJECT) { 521 cfg->fc_scope = RT_SCOPE_HOST; 522 cfg->fc_type = RTN_UNREACHABLE; 523 return 0; 524 } 525 526 cfg->fc_scope = RT_SCOPE_NOWHERE; 527 cfg->fc_type = RTN_UNICAST; 528 529 if (rt->rt_dev) { 530 char *colon; 531 struct net_device *dev; 532 char devname[IFNAMSIZ]; 533 534 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 535 return -EFAULT; 536 537 devname[IFNAMSIZ-1] = 0; 538 colon = strchr(devname, ':'); 539 if (colon) 540 *colon = 0; 541 dev = __dev_get_by_name(net, devname); 542 if (!dev) 543 return -ENODEV; 544 cfg->fc_oif = dev->ifindex; 545 cfg->fc_table = l3mdev_fib_table(dev); 546 if (colon) { 547 const struct in_ifaddr *ifa; 548 struct in_device *in_dev; 549 550 in_dev = __in_dev_get_rtnl(dev); 551 if (!in_dev) 552 return -ENODEV; 553 554 *colon = ':'; 555 556 rcu_read_lock(); 557 in_dev_for_each_ifa_rcu(ifa, in_dev) { 558 if (strcmp(ifa->ifa_label, devname) == 0) 559 break; 560 } 561 rcu_read_unlock(); 562 563 if (!ifa) 564 return -ENODEV; 565 cfg->fc_prefsrc = ifa->ifa_local; 566 } 567 } 568 569 addr = sk_extract_addr(&rt->rt_gateway); 570 if (rt->rt_gateway.sa_family == AF_INET && addr) { 571 unsigned int addr_type; 572 573 cfg->fc_gw4 = addr; 574 cfg->fc_gw_family = AF_INET; 575 addr_type = inet_addr_type_table(net, addr, cfg->fc_table); 576 if (rt->rt_flags & RTF_GATEWAY && 577 addr_type == RTN_UNICAST) 578 cfg->fc_scope = RT_SCOPE_UNIVERSE; 579 } 580 581 if (cmd == SIOCDELRT) 582 return 0; 583 584 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family) 585 return -EINVAL; 586 587 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 588 cfg->fc_scope = RT_SCOPE_LINK; 589 590 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 591 struct nlattr *mx; 592 int len = 0; 593 594 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL); 595 if (!mx) 596 return -ENOMEM; 597 598 if (rt->rt_flags & RTF_MTU) 599 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 600 601 if (rt->rt_flags & RTF_WINDOW) 602 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 603 604 if (rt->rt_flags & RTF_IRTT) 605 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 606 607 cfg->fc_mx = mx; 608 cfg->fc_mx_len = len; 609 } 610 611 return 0; 612 } 613 614 /* 615 * Handle IP routing ioctl calls. 616 * These are used to manipulate the routing tables 617 */ 618 int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt) 619 { 620 struct fib_config cfg; 621 int err; 622 623 switch (cmd) { 624 case SIOCADDRT: /* Add a route */ 625 case SIOCDELRT: /* Delete a route */ 626 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 627 return -EPERM; 628 629 rtnl_lock(); 630 err = rtentry_to_fib_config(net, cmd, rt, &cfg); 631 if (err == 0) { 632 struct fib_table *tb; 633 634 if (cmd == SIOCDELRT) { 635 tb = fib_get_table(net, cfg.fc_table); 636 if (tb) 637 err = fib_table_delete(net, tb, &cfg, 638 NULL); 639 else 640 err = -ESRCH; 641 } else { 642 tb = fib_new_table(net, cfg.fc_table); 643 if (tb) 644 err = fib_table_insert(net, tb, 645 &cfg, NULL); 646 else 647 err = -ENOBUFS; 648 } 649 650 /* allocated by rtentry_to_fib_config() */ 651 kfree(cfg.fc_mx); 652 } 653 rtnl_unlock(); 654 return err; 655 } 656 return -EINVAL; 657 } 658 659 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 660 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 }, 661 [RTA_DST] = { .type = NLA_U32 }, 662 [RTA_SRC] = { .type = NLA_U32 }, 663 [RTA_IIF] = { .type = NLA_U32 }, 664 [RTA_OIF] = { .type = NLA_U32 }, 665 [RTA_GATEWAY] = { .type = NLA_U32 }, 666 [RTA_PRIORITY] = { .type = NLA_U32 }, 667 [RTA_PREFSRC] = { .type = NLA_U32 }, 668 [RTA_METRICS] = { .type = NLA_NESTED }, 669 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 670 [RTA_FLOW] = { .type = NLA_U32 }, 671 [RTA_ENCAP_TYPE] = { .type = NLA_U16 }, 672 [RTA_ENCAP] = { .type = NLA_NESTED }, 673 [RTA_UID] = { .type = NLA_U32 }, 674 [RTA_MARK] = { .type = NLA_U32 }, 675 [RTA_TABLE] = { .type = NLA_U32 }, 676 [RTA_IP_PROTO] = { .type = NLA_U8 }, 677 [RTA_SPORT] = { .type = NLA_U16 }, 678 [RTA_DPORT] = { .type = NLA_U16 }, 679 [RTA_NH_ID] = { .type = NLA_U32 }, 680 }; 681 682 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, 683 struct netlink_ext_ack *extack) 684 { 685 struct rtvia *via; 686 int alen; 687 688 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) { 689 NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA"); 690 return -EINVAL; 691 } 692 693 via = nla_data(nla); 694 alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr); 695 696 switch (via->rtvia_family) { 697 case AF_INET: 698 if (alen != sizeof(__be32)) { 699 NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA"); 700 return -EINVAL; 701 } 702 cfg->fc_gw_family = AF_INET; 703 cfg->fc_gw4 = *((__be32 *)via->rtvia_addr); 704 break; 705 case AF_INET6: 706 #ifdef CONFIG_IPV6 707 if (alen != sizeof(struct in6_addr)) { 708 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA"); 709 return -EINVAL; 710 } 711 cfg->fc_gw_family = AF_INET6; 712 cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr); 713 #else 714 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel"); 715 return -EINVAL; 716 #endif 717 break; 718 default: 719 NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA"); 720 return -EINVAL; 721 } 722 723 return 0; 724 } 725 726 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 727 struct nlmsghdr *nlh, struct fib_config *cfg, 728 struct netlink_ext_ack *extack) 729 { 730 bool has_gw = false, has_via = false; 731 struct nlattr *attr; 732 int err, remaining; 733 struct rtmsg *rtm; 734 735 err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX, 736 rtm_ipv4_policy, extack); 737 if (err < 0) 738 goto errout; 739 740 memset(cfg, 0, sizeof(*cfg)); 741 742 rtm = nlmsg_data(nlh); 743 cfg->fc_dst_len = rtm->rtm_dst_len; 744 cfg->fc_tos = rtm->rtm_tos; 745 cfg->fc_table = rtm->rtm_table; 746 cfg->fc_protocol = rtm->rtm_protocol; 747 cfg->fc_scope = rtm->rtm_scope; 748 cfg->fc_type = rtm->rtm_type; 749 cfg->fc_flags = rtm->rtm_flags; 750 cfg->fc_nlflags = nlh->nlmsg_flags; 751 752 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid; 753 cfg->fc_nlinfo.nlh = nlh; 754 cfg->fc_nlinfo.nl_net = net; 755 756 if (cfg->fc_type > RTN_MAX) { 757 NL_SET_ERR_MSG(extack, "Invalid route type"); 758 err = -EINVAL; 759 goto errout; 760 } 761 762 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 763 switch (nla_type(attr)) { 764 case RTA_DST: 765 cfg->fc_dst = nla_get_be32(attr); 766 break; 767 case RTA_OIF: 768 cfg->fc_oif = nla_get_u32(attr); 769 break; 770 case RTA_GATEWAY: 771 has_gw = true; 772 cfg->fc_gw4 = nla_get_be32(attr); 773 if (cfg->fc_gw4) 774 cfg->fc_gw_family = AF_INET; 775 break; 776 case RTA_VIA: 777 has_via = true; 778 err = fib_gw_from_via(cfg, attr, extack); 779 if (err) 780 goto errout; 781 break; 782 case RTA_PRIORITY: 783 cfg->fc_priority = nla_get_u32(attr); 784 break; 785 case RTA_PREFSRC: 786 cfg->fc_prefsrc = nla_get_be32(attr); 787 break; 788 case RTA_METRICS: 789 cfg->fc_mx = nla_data(attr); 790 cfg->fc_mx_len = nla_len(attr); 791 break; 792 case RTA_MULTIPATH: 793 err = lwtunnel_valid_encap_type_attr(nla_data(attr), 794 nla_len(attr), 795 extack); 796 if (err < 0) 797 goto errout; 798 cfg->fc_mp = nla_data(attr); 799 cfg->fc_mp_len = nla_len(attr); 800 break; 801 case RTA_FLOW: 802 cfg->fc_flow = nla_get_u32(attr); 803 break; 804 case RTA_TABLE: 805 cfg->fc_table = nla_get_u32(attr); 806 break; 807 case RTA_ENCAP: 808 cfg->fc_encap = attr; 809 break; 810 case RTA_ENCAP_TYPE: 811 cfg->fc_encap_type = nla_get_u16(attr); 812 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, 813 extack); 814 if (err < 0) 815 goto errout; 816 break; 817 case RTA_NH_ID: 818 cfg->fc_nh_id = nla_get_u32(attr); 819 break; 820 } 821 } 822 823 if (cfg->fc_nh_id) { 824 if (cfg->fc_oif || cfg->fc_gw_family || 825 cfg->fc_encap || cfg->fc_mp) { 826 NL_SET_ERR_MSG(extack, 827 "Nexthop specification and nexthop id are mutually exclusive"); 828 return -EINVAL; 829 } 830 } 831 832 if (has_gw && has_via) { 833 NL_SET_ERR_MSG(extack, 834 "Nexthop configuration can not contain both GATEWAY and VIA"); 835 goto errout; 836 } 837 838 return 0; 839 errout: 840 return err; 841 } 842 843 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, 844 struct netlink_ext_ack *extack) 845 { 846 struct net *net = sock_net(skb->sk); 847 struct fib_config cfg; 848 struct fib_table *tb; 849 int err; 850 851 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 852 if (err < 0) 853 goto errout; 854 855 if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) { 856 NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); 857 err = -EINVAL; 858 goto errout; 859 } 860 861 tb = fib_get_table(net, cfg.fc_table); 862 if (!tb) { 863 NL_SET_ERR_MSG(extack, "FIB table does not exist"); 864 err = -ESRCH; 865 goto errout; 866 } 867 868 err = fib_table_delete(net, tb, &cfg, extack); 869 errout: 870 return err; 871 } 872 873 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, 874 struct netlink_ext_ack *extack) 875 { 876 struct net *net = sock_net(skb->sk); 877 struct fib_config cfg; 878 struct fib_table *tb; 879 int err; 880 881 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 882 if (err < 0) 883 goto errout; 884 885 tb = fib_new_table(net, cfg.fc_table); 886 if (!tb) { 887 err = -ENOBUFS; 888 goto errout; 889 } 890 891 err = fib_table_insert(net, tb, &cfg, extack); 892 if (!err && cfg.fc_type == RTN_LOCAL) 893 net->ipv4.fib_has_custom_local_routes = true; 894 errout: 895 return err; 896 } 897 898 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 899 struct fib_dump_filter *filter, 900 struct netlink_callback *cb) 901 { 902 struct netlink_ext_ack *extack = cb->extack; 903 struct nlattr *tb[RTA_MAX + 1]; 904 struct rtmsg *rtm; 905 int err, i; 906 907 ASSERT_RTNL(); 908 909 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 910 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request"); 911 return -EINVAL; 912 } 913 914 rtm = nlmsg_data(nlh); 915 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos || 916 rtm->rtm_scope) { 917 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request"); 918 return -EINVAL; 919 } 920 921 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) { 922 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request"); 923 return -EINVAL; 924 } 925 if (rtm->rtm_flags & RTM_F_CLONED) 926 filter->dump_routes = false; 927 else 928 filter->dump_exceptions = false; 929 930 filter->dump_all_families = (rtm->rtm_family == AF_UNSPEC); 931 filter->flags = rtm->rtm_flags; 932 filter->protocol = rtm->rtm_protocol; 933 filter->rt_type = rtm->rtm_type; 934 filter->table_id = rtm->rtm_table; 935 936 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 937 rtm_ipv4_policy, extack); 938 if (err < 0) 939 return err; 940 941 for (i = 0; i <= RTA_MAX; ++i) { 942 int ifindex; 943 944 if (!tb[i]) 945 continue; 946 947 switch (i) { 948 case RTA_TABLE: 949 filter->table_id = nla_get_u32(tb[i]); 950 break; 951 case RTA_OIF: 952 ifindex = nla_get_u32(tb[i]); 953 filter->dev = __dev_get_by_index(net, ifindex); 954 if (!filter->dev) 955 return -ENODEV; 956 break; 957 default: 958 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request"); 959 return -EINVAL; 960 } 961 } 962 963 if (filter->flags || filter->protocol || filter->rt_type || 964 filter->table_id || filter->dev) { 965 filter->filter_set = 1; 966 cb->answer_flags = NLM_F_DUMP_FILTERED; 967 } 968 969 return 0; 970 } 971 EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req); 972 973 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 974 { 975 struct fib_dump_filter filter = { .dump_routes = true, 976 .dump_exceptions = true }; 977 const struct nlmsghdr *nlh = cb->nlh; 978 struct net *net = sock_net(skb->sk); 979 unsigned int h, s_h; 980 unsigned int e = 0, s_e; 981 struct fib_table *tb; 982 struct hlist_head *head; 983 int dumped = 0, err; 984 985 if (cb->strict_check) { 986 err = ip_valid_fib_dump_req(net, nlh, &filter, cb); 987 if (err < 0) 988 return err; 989 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 990 struct rtmsg *rtm = nlmsg_data(nlh); 991 992 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED); 993 } 994 995 /* ipv4 does not use prefix flag */ 996 if (filter.flags & RTM_F_PREFIX) 997 return skb->len; 998 999 if (filter.table_id) { 1000 tb = fib_get_table(net, filter.table_id); 1001 if (!tb) { 1002 if (filter.dump_all_families) 1003 return skb->len; 1004 1005 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist"); 1006 return -ENOENT; 1007 } 1008 1009 err = fib_table_dump(tb, skb, cb, &filter); 1010 return skb->len ? : err; 1011 } 1012 1013 s_h = cb->args[0]; 1014 s_e = cb->args[1]; 1015 1016 rcu_read_lock(); 1017 1018 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 1019 e = 0; 1020 head = &net->ipv4.fib_table_hash[h]; 1021 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 1022 if (e < s_e) 1023 goto next; 1024 if (dumped) 1025 memset(&cb->args[2], 0, sizeof(cb->args) - 1026 2 * sizeof(cb->args[0])); 1027 err = fib_table_dump(tb, skb, cb, &filter); 1028 if (err < 0) { 1029 if (likely(skb->len)) 1030 goto out; 1031 1032 goto out_err; 1033 } 1034 dumped = 1; 1035 next: 1036 e++; 1037 } 1038 } 1039 out: 1040 err = skb->len; 1041 out_err: 1042 rcu_read_unlock(); 1043 1044 cb->args[1] = e; 1045 cb->args[0] = h; 1046 1047 return err; 1048 } 1049 1050 /* Prepare and feed intra-kernel routing request. 1051 * Really, it should be netlink message, but :-( netlink 1052 * can be not configured, so that we feed it directly 1053 * to fib engine. It is legal, because all events occur 1054 * only when netlink is already locked. 1055 */ 1056 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, 1057 struct in_ifaddr *ifa, u32 rt_priority) 1058 { 1059 struct net *net = dev_net(ifa->ifa_dev->dev); 1060 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev); 1061 struct fib_table *tb; 1062 struct fib_config cfg = { 1063 .fc_protocol = RTPROT_KERNEL, 1064 .fc_type = type, 1065 .fc_dst = dst, 1066 .fc_dst_len = dst_len, 1067 .fc_priority = rt_priority, 1068 .fc_prefsrc = ifa->ifa_local, 1069 .fc_oif = ifa->ifa_dev->dev->ifindex, 1070 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 1071 .fc_nlinfo = { 1072 .nl_net = net, 1073 }, 1074 }; 1075 1076 if (!tb_id) 1077 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL; 1078 1079 tb = fib_new_table(net, tb_id); 1080 if (!tb) 1081 return; 1082 1083 cfg.fc_table = tb->tb_id; 1084 1085 if (type != RTN_LOCAL) 1086 cfg.fc_scope = RT_SCOPE_LINK; 1087 else 1088 cfg.fc_scope = RT_SCOPE_HOST; 1089 1090 if (cmd == RTM_NEWROUTE) 1091 fib_table_insert(net, tb, &cfg, NULL); 1092 else 1093 fib_table_delete(net, tb, &cfg, NULL); 1094 } 1095 1096 void fib_add_ifaddr(struct in_ifaddr *ifa) 1097 { 1098 struct in_device *in_dev = ifa->ifa_dev; 1099 struct net_device *dev = in_dev->dev; 1100 struct in_ifaddr *prim = ifa; 1101 __be32 mask = ifa->ifa_mask; 1102 __be32 addr = ifa->ifa_local; 1103 __be32 prefix = ifa->ifa_address & mask; 1104 1105 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1106 prim = inet_ifa_byprefix(in_dev, prefix, mask); 1107 if (!prim) { 1108 pr_warn("%s: bug: prim == NULL\n", __func__); 1109 return; 1110 } 1111 } 1112 1113 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0); 1114 1115 if (!(dev->flags & IFF_UP)) 1116 return; 1117 1118 /* Add broadcast address, if it is explicitly assigned. */ 1119 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 1120 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1121 prim, 0); 1122 1123 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 1124 (prefix != addr || ifa->ifa_prefixlen < 32)) { 1125 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1126 fib_magic(RTM_NEWROUTE, 1127 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1128 prefix, ifa->ifa_prefixlen, prim, 1129 ifa->ifa_rt_priority); 1130 1131 /* Add network specific broadcasts, when it takes a sense */ 1132 if (ifa->ifa_prefixlen < 31) { 1133 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, 1134 prim, 0); 1135 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 1136 32, prim, 0); 1137 } 1138 } 1139 } 1140 1141 void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric) 1142 { 1143 __be32 prefix = ifa->ifa_address & ifa->ifa_mask; 1144 struct in_device *in_dev = ifa->ifa_dev; 1145 struct net_device *dev = in_dev->dev; 1146 1147 if (!(dev->flags & IFF_UP) || 1148 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) || 1149 ipv4_is_zeronet(prefix) || 1150 prefix == ifa->ifa_local || ifa->ifa_prefixlen == 32) 1151 return; 1152 1153 /* add the new */ 1154 fib_magic(RTM_NEWROUTE, 1155 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1156 prefix, ifa->ifa_prefixlen, ifa, new_metric); 1157 1158 /* delete the old */ 1159 fib_magic(RTM_DELROUTE, 1160 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1161 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority); 1162 } 1163 1164 /* Delete primary or secondary address. 1165 * Optionally, on secondary address promotion consider the addresses 1166 * from subnet iprim as deleted, even if they are in device list. 1167 * In this case the secondary ifa can be in device list. 1168 */ 1169 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 1170 { 1171 struct in_device *in_dev = ifa->ifa_dev; 1172 struct net_device *dev = in_dev->dev; 1173 struct in_ifaddr *ifa1; 1174 struct in_ifaddr *prim = ifa, *prim1 = NULL; 1175 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 1176 __be32 any = ifa->ifa_address & ifa->ifa_mask; 1177 #define LOCAL_OK 1 1178 #define BRD_OK 2 1179 #define BRD0_OK 4 1180 #define BRD1_OK 8 1181 unsigned int ok = 0; 1182 int subnet = 0; /* Primary network */ 1183 int gone = 1; /* Address is missing */ 1184 int same_prefsrc = 0; /* Another primary with same IP */ 1185 1186 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1187 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 1188 if (!prim) { 1189 /* if the device has been deleted, we don't perform 1190 * address promotion 1191 */ 1192 if (!in_dev->dead) 1193 pr_warn("%s: bug: prim == NULL\n", __func__); 1194 return; 1195 } 1196 if (iprim && iprim != prim) { 1197 pr_warn("%s: bug: iprim != prim\n", __func__); 1198 return; 1199 } 1200 } else if (!ipv4_is_zeronet(any) && 1201 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 1202 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1203 fib_magic(RTM_DELROUTE, 1204 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1205 any, ifa->ifa_prefixlen, prim, 0); 1206 subnet = 1; 1207 } 1208 1209 if (in_dev->dead) 1210 goto no_promotions; 1211 1212 /* Deletion is more complicated than add. 1213 * We should take care of not to delete too much :-) 1214 * 1215 * Scan address list to be sure that addresses are really gone. 1216 */ 1217 rcu_read_lock(); 1218 in_dev_for_each_ifa_rcu(ifa1, in_dev) { 1219 if (ifa1 == ifa) { 1220 /* promotion, keep the IP */ 1221 gone = 0; 1222 continue; 1223 } 1224 /* Ignore IFAs from our subnet */ 1225 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 1226 inet_ifa_match(ifa1->ifa_address, iprim)) 1227 continue; 1228 1229 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 1230 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 1231 /* Another address from our subnet? */ 1232 if (ifa1->ifa_mask == prim->ifa_mask && 1233 inet_ifa_match(ifa1->ifa_address, prim)) 1234 prim1 = prim; 1235 else { 1236 /* We reached the secondaries, so 1237 * same_prefsrc should be determined. 1238 */ 1239 if (!same_prefsrc) 1240 continue; 1241 /* Search new prim1 if ifa1 is not 1242 * using the current prim1 1243 */ 1244 if (!prim1 || 1245 ifa1->ifa_mask != prim1->ifa_mask || 1246 !inet_ifa_match(ifa1->ifa_address, prim1)) 1247 prim1 = inet_ifa_byprefix(in_dev, 1248 ifa1->ifa_address, 1249 ifa1->ifa_mask); 1250 if (!prim1) 1251 continue; 1252 if (prim1->ifa_local != prim->ifa_local) 1253 continue; 1254 } 1255 } else { 1256 if (prim->ifa_local != ifa1->ifa_local) 1257 continue; 1258 prim1 = ifa1; 1259 if (prim != prim1) 1260 same_prefsrc = 1; 1261 } 1262 if (ifa->ifa_local == ifa1->ifa_local) 1263 ok |= LOCAL_OK; 1264 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 1265 ok |= BRD_OK; 1266 if (brd == ifa1->ifa_broadcast) 1267 ok |= BRD1_OK; 1268 if (any == ifa1->ifa_broadcast) 1269 ok |= BRD0_OK; 1270 /* primary has network specific broadcasts */ 1271 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 1272 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 1273 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 1274 1275 if (!ipv4_is_zeronet(any1)) { 1276 if (ifa->ifa_broadcast == brd1 || 1277 ifa->ifa_broadcast == any1) 1278 ok |= BRD_OK; 1279 if (brd == brd1 || brd == any1) 1280 ok |= BRD1_OK; 1281 if (any == brd1 || any == any1) 1282 ok |= BRD0_OK; 1283 } 1284 } 1285 } 1286 rcu_read_unlock(); 1287 1288 no_promotions: 1289 if (!(ok & BRD_OK)) 1290 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1291 prim, 0); 1292 if (subnet && ifa->ifa_prefixlen < 31) { 1293 if (!(ok & BRD1_OK)) 1294 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, 1295 prim, 0); 1296 if (!(ok & BRD0_OK)) 1297 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, 1298 prim, 0); 1299 } 1300 if (!(ok & LOCAL_OK)) { 1301 unsigned int addr_type; 1302 1303 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0); 1304 1305 /* Check, that this local address finally disappeared. */ 1306 addr_type = inet_addr_type_dev_table(dev_net(dev), dev, 1307 ifa->ifa_local); 1308 if (gone && addr_type != RTN_LOCAL) { 1309 /* And the last, but not the least thing. 1310 * We must flush stray FIB entries. 1311 * 1312 * First of all, we scan fib_info list searching 1313 * for stray nexthop entries, then ignite fib_flush. 1314 */ 1315 if (fib_sync_down_addr(dev, ifa->ifa_local)) 1316 fib_flush(dev_net(dev)); 1317 } 1318 } 1319 #undef LOCAL_OK 1320 #undef BRD_OK 1321 #undef BRD0_OK 1322 #undef BRD1_OK 1323 } 1324 1325 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn) 1326 { 1327 1328 struct fib_result res; 1329 struct flowi4 fl4 = { 1330 .flowi4_mark = frn->fl_mark, 1331 .daddr = frn->fl_addr, 1332 .flowi4_tos = frn->fl_tos, 1333 .flowi4_scope = frn->fl_scope, 1334 }; 1335 struct fib_table *tb; 1336 1337 rcu_read_lock(); 1338 1339 tb = fib_get_table(net, frn->tb_id_in); 1340 1341 frn->err = -ENOENT; 1342 if (tb) { 1343 local_bh_disable(); 1344 1345 frn->tb_id = tb->tb_id; 1346 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 1347 1348 if (!frn->err) { 1349 frn->prefixlen = res.prefixlen; 1350 frn->nh_sel = res.nh_sel; 1351 frn->type = res.type; 1352 frn->scope = res.scope; 1353 } 1354 local_bh_enable(); 1355 } 1356 1357 rcu_read_unlock(); 1358 } 1359 1360 static void nl_fib_input(struct sk_buff *skb) 1361 { 1362 struct net *net; 1363 struct fib_result_nl *frn; 1364 struct nlmsghdr *nlh; 1365 u32 portid; 1366 1367 net = sock_net(skb->sk); 1368 nlh = nlmsg_hdr(skb); 1369 if (skb->len < nlmsg_total_size(sizeof(*frn)) || 1370 skb->len < nlh->nlmsg_len || 1371 nlmsg_len(nlh) < sizeof(*frn)) 1372 return; 1373 1374 skb = netlink_skb_clone(skb, GFP_KERNEL); 1375 if (!skb) 1376 return; 1377 nlh = nlmsg_hdr(skb); 1378 1379 frn = (struct fib_result_nl *) nlmsg_data(nlh); 1380 nl_fib_lookup(net, frn); 1381 1382 portid = NETLINK_CB(skb).portid; /* netlink portid */ 1383 NETLINK_CB(skb).portid = 0; /* from kernel */ 1384 NETLINK_CB(skb).dst_group = 0; /* unicast */ 1385 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT); 1386 } 1387 1388 static int __net_init nl_fib_lookup_init(struct net *net) 1389 { 1390 struct sock *sk; 1391 struct netlink_kernel_cfg cfg = { 1392 .input = nl_fib_input, 1393 }; 1394 1395 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg); 1396 if (!sk) 1397 return -EAFNOSUPPORT; 1398 net->ipv4.fibnl = sk; 1399 return 0; 1400 } 1401 1402 static void nl_fib_lookup_exit(struct net *net) 1403 { 1404 netlink_kernel_release(net->ipv4.fibnl); 1405 net->ipv4.fibnl = NULL; 1406 } 1407 1408 static void fib_disable_ip(struct net_device *dev, unsigned long event, 1409 bool force) 1410 { 1411 if (fib_sync_down_dev(dev, event, force)) 1412 fib_flush(dev_net(dev)); 1413 else 1414 rt_cache_flush(dev_net(dev)); 1415 arp_ifdown(dev); 1416 } 1417 1418 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 1419 { 1420 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 1421 struct net_device *dev = ifa->ifa_dev->dev; 1422 struct net *net = dev_net(dev); 1423 1424 switch (event) { 1425 case NETDEV_UP: 1426 fib_add_ifaddr(ifa); 1427 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1428 fib_sync_up(dev, RTNH_F_DEAD); 1429 #endif 1430 atomic_inc(&net->ipv4.dev_addr_genid); 1431 rt_cache_flush(dev_net(dev)); 1432 break; 1433 case NETDEV_DOWN: 1434 fib_del_ifaddr(ifa, NULL); 1435 atomic_inc(&net->ipv4.dev_addr_genid); 1436 if (!ifa->ifa_dev->ifa_list) { 1437 /* Last address was deleted from this interface. 1438 * Disable IP. 1439 */ 1440 fib_disable_ip(dev, event, true); 1441 } else { 1442 rt_cache_flush(dev_net(dev)); 1443 } 1444 break; 1445 } 1446 return NOTIFY_DONE; 1447 } 1448 1449 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1450 { 1451 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1452 struct netdev_notifier_changeupper_info *upper_info = ptr; 1453 struct netdev_notifier_info_ext *info_ext = ptr; 1454 struct in_device *in_dev; 1455 struct net *net = dev_net(dev); 1456 struct in_ifaddr *ifa; 1457 unsigned int flags; 1458 1459 if (event == NETDEV_UNREGISTER) { 1460 fib_disable_ip(dev, event, true); 1461 rt_flush_dev(dev); 1462 return NOTIFY_DONE; 1463 } 1464 1465 in_dev = __in_dev_get_rtnl(dev); 1466 if (!in_dev) 1467 return NOTIFY_DONE; 1468 1469 switch (event) { 1470 case NETDEV_UP: 1471 in_dev_for_each_ifa_rtnl(ifa, in_dev) { 1472 fib_add_ifaddr(ifa); 1473 } 1474 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1475 fib_sync_up(dev, RTNH_F_DEAD); 1476 #endif 1477 atomic_inc(&net->ipv4.dev_addr_genid); 1478 rt_cache_flush(net); 1479 break; 1480 case NETDEV_DOWN: 1481 fib_disable_ip(dev, event, false); 1482 break; 1483 case NETDEV_CHANGE: 1484 flags = dev_get_flags(dev); 1485 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1486 fib_sync_up(dev, RTNH_F_LINKDOWN); 1487 else 1488 fib_sync_down_dev(dev, event, false); 1489 rt_cache_flush(net); 1490 break; 1491 case NETDEV_CHANGEMTU: 1492 fib_sync_mtu(dev, info_ext->ext.mtu); 1493 rt_cache_flush(net); 1494 break; 1495 case NETDEV_CHANGEUPPER: 1496 upper_info = ptr; 1497 /* flush all routes if dev is linked to or unlinked from 1498 * an L3 master device (e.g., VRF) 1499 */ 1500 if (upper_info->upper_dev && 1501 netif_is_l3_master(upper_info->upper_dev)) 1502 fib_disable_ip(dev, NETDEV_DOWN, true); 1503 break; 1504 } 1505 return NOTIFY_DONE; 1506 } 1507 1508 static struct notifier_block fib_inetaddr_notifier = { 1509 .notifier_call = fib_inetaddr_event, 1510 }; 1511 1512 static struct notifier_block fib_netdev_notifier = { 1513 .notifier_call = fib_netdev_event, 1514 }; 1515 1516 static int __net_init ip_fib_net_init(struct net *net) 1517 { 1518 int err; 1519 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1520 1521 err = fib4_notifier_init(net); 1522 if (err) 1523 return err; 1524 1525 /* Avoid false sharing : Use at least a full cache line */ 1526 size = max_t(size_t, size, L1_CACHE_BYTES); 1527 1528 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1529 if (!net->ipv4.fib_table_hash) { 1530 err = -ENOMEM; 1531 goto err_table_hash_alloc; 1532 } 1533 1534 err = fib4_rules_init(net); 1535 if (err < 0) 1536 goto err_rules_init; 1537 return 0; 1538 1539 err_rules_init: 1540 kfree(net->ipv4.fib_table_hash); 1541 err_table_hash_alloc: 1542 fib4_notifier_exit(net); 1543 return err; 1544 } 1545 1546 static void ip_fib_net_exit(struct net *net) 1547 { 1548 int i; 1549 1550 rtnl_lock(); 1551 #ifdef CONFIG_IP_MULTIPLE_TABLES 1552 RCU_INIT_POINTER(net->ipv4.fib_main, NULL); 1553 RCU_INIT_POINTER(net->ipv4.fib_default, NULL); 1554 #endif 1555 /* Destroy the tables in reverse order to guarantee that the 1556 * local table, ID 255, is destroyed before the main table, ID 1557 * 254. This is necessary as the local table may contain 1558 * references to data contained in the main table. 1559 */ 1560 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) { 1561 struct hlist_head *head = &net->ipv4.fib_table_hash[i]; 1562 struct hlist_node *tmp; 1563 struct fib_table *tb; 1564 1565 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) { 1566 hlist_del(&tb->tb_hlist); 1567 fib_table_flush(net, tb, true); 1568 fib_free_table(tb); 1569 } 1570 } 1571 1572 #ifdef CONFIG_IP_MULTIPLE_TABLES 1573 fib4_rules_exit(net); 1574 #endif 1575 rtnl_unlock(); 1576 kfree(net->ipv4.fib_table_hash); 1577 fib4_notifier_exit(net); 1578 } 1579 1580 static int __net_init fib_net_init(struct net *net) 1581 { 1582 int error; 1583 1584 #ifdef CONFIG_IP_ROUTE_CLASSID 1585 net->ipv4.fib_num_tclassid_users = 0; 1586 #endif 1587 error = ip_fib_net_init(net); 1588 if (error < 0) 1589 goto out; 1590 error = nl_fib_lookup_init(net); 1591 if (error < 0) 1592 goto out_nlfl; 1593 error = fib_proc_init(net); 1594 if (error < 0) 1595 goto out_proc; 1596 out: 1597 return error; 1598 1599 out_proc: 1600 nl_fib_lookup_exit(net); 1601 out_nlfl: 1602 ip_fib_net_exit(net); 1603 goto out; 1604 } 1605 1606 static void __net_exit fib_net_exit(struct net *net) 1607 { 1608 fib_proc_exit(net); 1609 nl_fib_lookup_exit(net); 1610 ip_fib_net_exit(net); 1611 } 1612 1613 static struct pernet_operations fib_net_ops = { 1614 .init = fib_net_init, 1615 .exit = fib_net_exit, 1616 }; 1617 1618 void __init ip_fib_init(void) 1619 { 1620 fib_trie_init(); 1621 1622 register_pernet_subsys(&fib_net_ops); 1623 1624 register_netdevice_notifier(&fib_netdev_notifier); 1625 register_inetaddr_notifier(&fib_inetaddr_notifier); 1626 1627 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0); 1628 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0); 1629 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0); 1630 } 1631