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 = ip_hdr(skb)->tos & IPTOS_RT_MASK, 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 if (unlikely(fi->nh)) { 313 dev_match = nexthop_uses_dev(fi->nh, dev); 314 } else { 315 int ret; 316 317 for (ret = 0; ret < fib_info_num_path(fi); ret++) { 318 const struct fib_nh_common *nhc = fib_info_nhc(fi, ret); 319 320 if (nhc_l3mdev_matches_dev(nhc, dev)) { 321 dev_match = true; 322 break; 323 } 324 } 325 } 326 #else 327 if (fib_info_nhc(fi, 0)->nhc_dev == dev) 328 dev_match = true; 329 #endif 330 331 return dev_match; 332 } 333 EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev); 334 335 /* Given (packet source, input interface) and optional (dst, oif, tos): 336 * - (main) check, that source is valid i.e. not broadcast or our local 337 * address. 338 * - figure out what "logical" interface this packet arrived 339 * and calculate "specific destination" address. 340 * - check, that packet arrived from expected physical interface. 341 * called with rcu_read_lock() 342 */ 343 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 344 u8 tos, int oif, struct net_device *dev, 345 int rpf, struct in_device *idev, u32 *itag) 346 { 347 struct net *net = dev_net(dev); 348 struct flow_keys flkeys; 349 int ret, no_addr; 350 struct fib_result res; 351 struct flowi4 fl4; 352 bool dev_match; 353 354 fl4.flowi4_oif = 0; 355 fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev); 356 if (!fl4.flowi4_iif) 357 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX; 358 fl4.daddr = src; 359 fl4.saddr = dst; 360 fl4.flowi4_tos = tos; 361 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 362 fl4.flowi4_tun_key.tun_id = 0; 363 fl4.flowi4_flags = 0; 364 fl4.flowi4_uid = sock_net_uid(net, NULL); 365 fl4.flowi4_multipath_hash = 0; 366 367 no_addr = idev->ifa_list == NULL; 368 369 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0; 370 if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) { 371 fl4.flowi4_proto = 0; 372 fl4.fl4_sport = 0; 373 fl4.fl4_dport = 0; 374 } else { 375 swap(fl4.fl4_sport, fl4.fl4_dport); 376 } 377 378 if (fib_lookup(net, &fl4, &res, 0)) 379 goto last_resort; 380 if (res.type != RTN_UNICAST && 381 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev))) 382 goto e_inval; 383 fib_combine_itag(itag, &res); 384 385 dev_match = fib_info_nh_uses_dev(res.fi, dev); 386 /* This is not common, loopback packets retain skb_dst so normally they 387 * would not even hit this slow path. 388 */ 389 dev_match = dev_match || (res.type == RTN_LOCAL && 390 dev == net->loopback_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 /* Within the same container, it is regarded as a martian source, 440 * and the same host but different containers are not. 441 */ 442 if (inet_lookup_ifaddr_rcu(net, src)) 443 return -EINVAL; 444 445 ok: 446 *itag = 0; 447 return 0; 448 } 449 450 full_check: 451 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag); 452 } 453 454 static inline __be32 sk_extract_addr(struct sockaddr *addr) 455 { 456 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 457 } 458 459 static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 460 { 461 struct nlattr *nla; 462 463 nla = (struct nlattr *) ((char *) mx + len); 464 nla->nla_type = type; 465 nla->nla_len = nla_attr_size(4); 466 *(u32 *) nla_data(nla) = value; 467 468 return len + nla_total_size(4); 469 } 470 471 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 472 struct fib_config *cfg) 473 { 474 __be32 addr; 475 int plen; 476 477 memset(cfg, 0, sizeof(*cfg)); 478 cfg->fc_nlinfo.nl_net = net; 479 480 if (rt->rt_dst.sa_family != AF_INET) 481 return -EAFNOSUPPORT; 482 483 /* 484 * Check mask for validity: 485 * a) it must be contiguous. 486 * b) destination must have all host bits clear. 487 * c) if application forgot to set correct family (AF_INET), 488 * reject request unless it is absolutely clear i.e. 489 * both family and mask are zero. 490 */ 491 plen = 32; 492 addr = sk_extract_addr(&rt->rt_dst); 493 if (!(rt->rt_flags & RTF_HOST)) { 494 __be32 mask = sk_extract_addr(&rt->rt_genmask); 495 496 if (rt->rt_genmask.sa_family != AF_INET) { 497 if (mask || rt->rt_genmask.sa_family) 498 return -EAFNOSUPPORT; 499 } 500 501 if (bad_mask(mask, addr)) 502 return -EINVAL; 503 504 plen = inet_mask_len(mask); 505 } 506 507 cfg->fc_dst_len = plen; 508 cfg->fc_dst = addr; 509 510 if (cmd != SIOCDELRT) { 511 cfg->fc_nlflags = NLM_F_CREATE; 512 cfg->fc_protocol = RTPROT_BOOT; 513 } 514 515 if (rt->rt_metric) 516 cfg->fc_priority = rt->rt_metric - 1; 517 518 if (rt->rt_flags & RTF_REJECT) { 519 cfg->fc_scope = RT_SCOPE_HOST; 520 cfg->fc_type = RTN_UNREACHABLE; 521 return 0; 522 } 523 524 cfg->fc_scope = RT_SCOPE_NOWHERE; 525 cfg->fc_type = RTN_UNICAST; 526 527 if (rt->rt_dev) { 528 char *colon; 529 struct net_device *dev; 530 char devname[IFNAMSIZ]; 531 532 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 533 return -EFAULT; 534 535 devname[IFNAMSIZ-1] = 0; 536 colon = strchr(devname, ':'); 537 if (colon) 538 *colon = 0; 539 dev = __dev_get_by_name(net, devname); 540 if (!dev) 541 return -ENODEV; 542 cfg->fc_oif = dev->ifindex; 543 cfg->fc_table = l3mdev_fib_table(dev); 544 if (colon) { 545 const struct in_ifaddr *ifa; 546 struct in_device *in_dev; 547 548 in_dev = __in_dev_get_rtnl(dev); 549 if (!in_dev) 550 return -ENODEV; 551 552 *colon = ':'; 553 554 rcu_read_lock(); 555 in_dev_for_each_ifa_rcu(ifa, in_dev) { 556 if (strcmp(ifa->ifa_label, devname) == 0) 557 break; 558 } 559 rcu_read_unlock(); 560 561 if (!ifa) 562 return -ENODEV; 563 cfg->fc_prefsrc = ifa->ifa_local; 564 } 565 } 566 567 addr = sk_extract_addr(&rt->rt_gateway); 568 if (rt->rt_gateway.sa_family == AF_INET && addr) { 569 unsigned int addr_type; 570 571 cfg->fc_gw4 = addr; 572 cfg->fc_gw_family = AF_INET; 573 addr_type = inet_addr_type_table(net, addr, cfg->fc_table); 574 if (rt->rt_flags & RTF_GATEWAY && 575 addr_type == RTN_UNICAST) 576 cfg->fc_scope = RT_SCOPE_UNIVERSE; 577 } 578 579 if (cmd == SIOCDELRT) 580 return 0; 581 582 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family) 583 return -EINVAL; 584 585 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 586 cfg->fc_scope = RT_SCOPE_LINK; 587 588 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 589 struct nlattr *mx; 590 int len = 0; 591 592 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL); 593 if (!mx) 594 return -ENOMEM; 595 596 if (rt->rt_flags & RTF_MTU) 597 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 598 599 if (rt->rt_flags & RTF_WINDOW) 600 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 601 602 if (rt->rt_flags & RTF_IRTT) 603 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 604 605 cfg->fc_mx = mx; 606 cfg->fc_mx_len = len; 607 } 608 609 return 0; 610 } 611 612 /* 613 * Handle IP routing ioctl calls. 614 * These are used to manipulate the routing tables 615 */ 616 int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt) 617 { 618 struct fib_config cfg; 619 int err; 620 621 switch (cmd) { 622 case SIOCADDRT: /* Add a route */ 623 case SIOCDELRT: /* Delete a route */ 624 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 625 return -EPERM; 626 627 rtnl_lock(); 628 err = rtentry_to_fib_config(net, cmd, rt, &cfg); 629 if (err == 0) { 630 struct fib_table *tb; 631 632 if (cmd == SIOCDELRT) { 633 tb = fib_get_table(net, cfg.fc_table); 634 if (tb) 635 err = fib_table_delete(net, tb, &cfg, 636 NULL); 637 else 638 err = -ESRCH; 639 } else { 640 tb = fib_new_table(net, cfg.fc_table); 641 if (tb) 642 err = fib_table_insert(net, tb, 643 &cfg, NULL); 644 else 645 err = -ENOBUFS; 646 } 647 648 /* allocated by rtentry_to_fib_config() */ 649 kfree(cfg.fc_mx); 650 } 651 rtnl_unlock(); 652 return err; 653 } 654 return -EINVAL; 655 } 656 657 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 658 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 }, 659 [RTA_DST] = { .type = NLA_U32 }, 660 [RTA_SRC] = { .type = NLA_U32 }, 661 [RTA_IIF] = { .type = NLA_U32 }, 662 [RTA_OIF] = { .type = NLA_U32 }, 663 [RTA_GATEWAY] = { .type = NLA_U32 }, 664 [RTA_PRIORITY] = { .type = NLA_U32 }, 665 [RTA_PREFSRC] = { .type = NLA_U32 }, 666 [RTA_METRICS] = { .type = NLA_NESTED }, 667 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 668 [RTA_FLOW] = { .type = NLA_U32 }, 669 [RTA_ENCAP_TYPE] = { .type = NLA_U16 }, 670 [RTA_ENCAP] = { .type = NLA_NESTED }, 671 [RTA_UID] = { .type = NLA_U32 }, 672 [RTA_MARK] = { .type = NLA_U32 }, 673 [RTA_TABLE] = { .type = NLA_U32 }, 674 [RTA_IP_PROTO] = { .type = NLA_U8 }, 675 [RTA_SPORT] = { .type = NLA_U16 }, 676 [RTA_DPORT] = { .type = NLA_U16 }, 677 [RTA_NH_ID] = { .type = NLA_U32 }, 678 }; 679 680 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, 681 struct netlink_ext_ack *extack) 682 { 683 struct rtvia *via; 684 int alen; 685 686 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) { 687 NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA"); 688 return -EINVAL; 689 } 690 691 via = nla_data(nla); 692 alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr); 693 694 switch (via->rtvia_family) { 695 case AF_INET: 696 if (alen != sizeof(__be32)) { 697 NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA"); 698 return -EINVAL; 699 } 700 cfg->fc_gw_family = AF_INET; 701 cfg->fc_gw4 = *((__be32 *)via->rtvia_addr); 702 break; 703 case AF_INET6: 704 #if IS_ENABLED(CONFIG_IPV6) 705 if (alen != sizeof(struct in6_addr)) { 706 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA"); 707 return -EINVAL; 708 } 709 cfg->fc_gw_family = AF_INET6; 710 cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr); 711 #else 712 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel"); 713 return -EINVAL; 714 #endif 715 break; 716 default: 717 NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA"); 718 return -EINVAL; 719 } 720 721 return 0; 722 } 723 724 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 725 struct nlmsghdr *nlh, struct fib_config *cfg, 726 struct netlink_ext_ack *extack) 727 { 728 bool has_gw = false, has_via = false; 729 struct nlattr *attr; 730 int err, remaining; 731 struct rtmsg *rtm; 732 733 err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX, 734 rtm_ipv4_policy, extack); 735 if (err < 0) 736 goto errout; 737 738 memset(cfg, 0, sizeof(*cfg)); 739 740 rtm = nlmsg_data(nlh); 741 cfg->fc_dst_len = rtm->rtm_dst_len; 742 cfg->fc_tos = rtm->rtm_tos; 743 cfg->fc_table = rtm->rtm_table; 744 cfg->fc_protocol = rtm->rtm_protocol; 745 cfg->fc_scope = rtm->rtm_scope; 746 cfg->fc_type = rtm->rtm_type; 747 cfg->fc_flags = rtm->rtm_flags; 748 cfg->fc_nlflags = nlh->nlmsg_flags; 749 750 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid; 751 cfg->fc_nlinfo.nlh = nlh; 752 cfg->fc_nlinfo.nl_net = net; 753 754 if (cfg->fc_type > RTN_MAX) { 755 NL_SET_ERR_MSG(extack, "Invalid route type"); 756 err = -EINVAL; 757 goto errout; 758 } 759 760 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 761 switch (nla_type(attr)) { 762 case RTA_DST: 763 cfg->fc_dst = nla_get_be32(attr); 764 break; 765 case RTA_OIF: 766 cfg->fc_oif = nla_get_u32(attr); 767 break; 768 case RTA_GATEWAY: 769 has_gw = true; 770 cfg->fc_gw4 = nla_get_be32(attr); 771 if (cfg->fc_gw4) 772 cfg->fc_gw_family = AF_INET; 773 break; 774 case RTA_VIA: 775 has_via = true; 776 err = fib_gw_from_via(cfg, attr, extack); 777 if (err) 778 goto errout; 779 break; 780 case RTA_PRIORITY: 781 cfg->fc_priority = nla_get_u32(attr); 782 break; 783 case RTA_PREFSRC: 784 cfg->fc_prefsrc = nla_get_be32(attr); 785 break; 786 case RTA_METRICS: 787 cfg->fc_mx = nla_data(attr); 788 cfg->fc_mx_len = nla_len(attr); 789 break; 790 case RTA_MULTIPATH: 791 err = lwtunnel_valid_encap_type_attr(nla_data(attr), 792 nla_len(attr), 793 extack); 794 if (err < 0) 795 goto errout; 796 cfg->fc_mp = nla_data(attr); 797 cfg->fc_mp_len = nla_len(attr); 798 break; 799 case RTA_FLOW: 800 cfg->fc_flow = nla_get_u32(attr); 801 break; 802 case RTA_TABLE: 803 cfg->fc_table = nla_get_u32(attr); 804 break; 805 case RTA_ENCAP: 806 cfg->fc_encap = attr; 807 break; 808 case RTA_ENCAP_TYPE: 809 cfg->fc_encap_type = nla_get_u16(attr); 810 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, 811 extack); 812 if (err < 0) 813 goto errout; 814 break; 815 case RTA_NH_ID: 816 cfg->fc_nh_id = nla_get_u32(attr); 817 break; 818 } 819 } 820 821 if (cfg->fc_nh_id) { 822 if (cfg->fc_oif || cfg->fc_gw_family || 823 cfg->fc_encap || cfg->fc_mp) { 824 NL_SET_ERR_MSG(extack, 825 "Nexthop specification and nexthop id are mutually exclusive"); 826 return -EINVAL; 827 } 828 } 829 830 if (has_gw && has_via) { 831 NL_SET_ERR_MSG(extack, 832 "Nexthop configuration can not contain both GATEWAY and VIA"); 833 return -EINVAL; 834 } 835 836 return 0; 837 errout: 838 return err; 839 } 840 841 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, 842 struct netlink_ext_ack *extack) 843 { 844 struct net *net = sock_net(skb->sk); 845 struct fib_config cfg; 846 struct fib_table *tb; 847 int err; 848 849 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 850 if (err < 0) 851 goto errout; 852 853 if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) { 854 NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); 855 err = -EINVAL; 856 goto errout; 857 } 858 859 tb = fib_get_table(net, cfg.fc_table); 860 if (!tb) { 861 NL_SET_ERR_MSG(extack, "FIB table does not exist"); 862 err = -ESRCH; 863 goto errout; 864 } 865 866 err = fib_table_delete(net, tb, &cfg, extack); 867 errout: 868 return err; 869 } 870 871 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, 872 struct netlink_ext_ack *extack) 873 { 874 struct net *net = sock_net(skb->sk); 875 struct fib_config cfg; 876 struct fib_table *tb; 877 int err; 878 879 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 880 if (err < 0) 881 goto errout; 882 883 tb = fib_new_table(net, cfg.fc_table); 884 if (!tb) { 885 err = -ENOBUFS; 886 goto errout; 887 } 888 889 err = fib_table_insert(net, tb, &cfg, extack); 890 if (!err && cfg.fc_type == RTN_LOCAL) 891 net->ipv4.fib_has_custom_local_routes = true; 892 errout: 893 return err; 894 } 895 896 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 897 struct fib_dump_filter *filter, 898 struct netlink_callback *cb) 899 { 900 struct netlink_ext_ack *extack = cb->extack; 901 struct nlattr *tb[RTA_MAX + 1]; 902 struct rtmsg *rtm; 903 int err, i; 904 905 ASSERT_RTNL(); 906 907 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 908 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request"); 909 return -EINVAL; 910 } 911 912 rtm = nlmsg_data(nlh); 913 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos || 914 rtm->rtm_scope) { 915 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request"); 916 return -EINVAL; 917 } 918 919 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) { 920 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request"); 921 return -EINVAL; 922 } 923 if (rtm->rtm_flags & RTM_F_CLONED) 924 filter->dump_routes = false; 925 else 926 filter->dump_exceptions = false; 927 928 filter->flags = rtm->rtm_flags; 929 filter->protocol = rtm->rtm_protocol; 930 filter->rt_type = rtm->rtm_type; 931 filter->table_id = rtm->rtm_table; 932 933 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 934 rtm_ipv4_policy, extack); 935 if (err < 0) 936 return err; 937 938 for (i = 0; i <= RTA_MAX; ++i) { 939 int ifindex; 940 941 if (!tb[i]) 942 continue; 943 944 switch (i) { 945 case RTA_TABLE: 946 filter->table_id = nla_get_u32(tb[i]); 947 break; 948 case RTA_OIF: 949 ifindex = nla_get_u32(tb[i]); 950 filter->dev = __dev_get_by_index(net, ifindex); 951 if (!filter->dev) 952 return -ENODEV; 953 break; 954 default: 955 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request"); 956 return -EINVAL; 957 } 958 } 959 960 if (filter->flags || filter->protocol || filter->rt_type || 961 filter->table_id || filter->dev) { 962 filter->filter_set = 1; 963 cb->answer_flags = NLM_F_DUMP_FILTERED; 964 } 965 966 return 0; 967 } 968 EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req); 969 970 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 971 { 972 struct fib_dump_filter filter = { .dump_routes = true, 973 .dump_exceptions = true }; 974 const struct nlmsghdr *nlh = cb->nlh; 975 struct net *net = sock_net(skb->sk); 976 unsigned int h, s_h; 977 unsigned int e = 0, s_e; 978 struct fib_table *tb; 979 struct hlist_head *head; 980 int dumped = 0, err; 981 982 if (cb->strict_check) { 983 err = ip_valid_fib_dump_req(net, nlh, &filter, cb); 984 if (err < 0) 985 return err; 986 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 987 struct rtmsg *rtm = nlmsg_data(nlh); 988 989 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED); 990 } 991 992 /* ipv4 does not use prefix flag */ 993 if (filter.flags & RTM_F_PREFIX) 994 return skb->len; 995 996 if (filter.table_id) { 997 tb = fib_get_table(net, filter.table_id); 998 if (!tb) { 999 if (rtnl_msg_family(cb->nlh) != PF_INET) 1000 return skb->len; 1001 1002 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist"); 1003 return -ENOENT; 1004 } 1005 1006 rcu_read_lock(); 1007 err = fib_table_dump(tb, skb, cb, &filter); 1008 rcu_read_unlock(); 1009 return skb->len ? : err; 1010 } 1011 1012 s_h = cb->args[0]; 1013 s_e = cb->args[1]; 1014 1015 rcu_read_lock(); 1016 1017 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 1018 e = 0; 1019 head = &net->ipv4.fib_table_hash[h]; 1020 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 1021 if (e < s_e) 1022 goto next; 1023 if (dumped) 1024 memset(&cb->args[2], 0, sizeof(cb->args) - 1025 2 * sizeof(cb->args[0])); 1026 err = fib_table_dump(tb, skb, cb, &filter); 1027 if (err < 0) { 1028 if (likely(skb->len)) 1029 goto out; 1030 1031 goto out_err; 1032 } 1033 dumped = 1; 1034 next: 1035 e++; 1036 } 1037 } 1038 out: 1039 err = skb->len; 1040 out_err: 1041 rcu_read_unlock(); 1042 1043 cb->args[1] = e; 1044 cb->args[0] = h; 1045 1046 return err; 1047 } 1048 1049 /* Prepare and feed intra-kernel routing request. 1050 * Really, it should be netlink message, but :-( netlink 1051 * can be not configured, so that we feed it directly 1052 * to fib engine. It is legal, because all events occur 1053 * only when netlink is already locked. 1054 */ 1055 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, 1056 struct in_ifaddr *ifa, u32 rt_priority) 1057 { 1058 struct net *net = dev_net(ifa->ifa_dev->dev); 1059 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev); 1060 struct fib_table *tb; 1061 struct fib_config cfg = { 1062 .fc_protocol = RTPROT_KERNEL, 1063 .fc_type = type, 1064 .fc_dst = dst, 1065 .fc_dst_len = dst_len, 1066 .fc_priority = rt_priority, 1067 .fc_prefsrc = ifa->ifa_local, 1068 .fc_oif = ifa->ifa_dev->dev->ifindex, 1069 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 1070 .fc_nlinfo = { 1071 .nl_net = net, 1072 }, 1073 }; 1074 1075 if (!tb_id) 1076 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL; 1077 1078 tb = fib_new_table(net, tb_id); 1079 if (!tb) 1080 return; 1081 1082 cfg.fc_table = tb->tb_id; 1083 1084 if (type != RTN_LOCAL) 1085 cfg.fc_scope = RT_SCOPE_LINK; 1086 else 1087 cfg.fc_scope = RT_SCOPE_HOST; 1088 1089 if (cmd == RTM_NEWROUTE) 1090 fib_table_insert(net, tb, &cfg, NULL); 1091 else 1092 fib_table_delete(net, tb, &cfg, NULL); 1093 } 1094 1095 void fib_add_ifaddr(struct in_ifaddr *ifa) 1096 { 1097 struct in_device *in_dev = ifa->ifa_dev; 1098 struct net_device *dev = in_dev->dev; 1099 struct in_ifaddr *prim = ifa; 1100 __be32 mask = ifa->ifa_mask; 1101 __be32 addr = ifa->ifa_local; 1102 __be32 prefix = ifa->ifa_address & mask; 1103 1104 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1105 prim = inet_ifa_byprefix(in_dev, prefix, mask); 1106 if (!prim) { 1107 pr_warn("%s: bug: prim == NULL\n", __func__); 1108 return; 1109 } 1110 } 1111 1112 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0); 1113 1114 if (!(dev->flags & IFF_UP)) 1115 return; 1116 1117 /* Add broadcast address, if it is explicitly assigned. */ 1118 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 1119 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1120 prim, 0); 1121 1122 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 1123 (prefix != addr || ifa->ifa_prefixlen < 32)) { 1124 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1125 fib_magic(RTM_NEWROUTE, 1126 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1127 prefix, ifa->ifa_prefixlen, prim, 1128 ifa->ifa_rt_priority); 1129 1130 /* Add the network broadcast address, when it makes sense */ 1131 if (ifa->ifa_prefixlen < 31) { 1132 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 1133 32, prim, 0); 1134 } 1135 } 1136 } 1137 1138 void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric) 1139 { 1140 __be32 prefix = ifa->ifa_address & ifa->ifa_mask; 1141 struct in_device *in_dev = ifa->ifa_dev; 1142 struct net_device *dev = in_dev->dev; 1143 1144 if (!(dev->flags & IFF_UP) || 1145 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) || 1146 ipv4_is_zeronet(prefix) || 1147 (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32)) 1148 return; 1149 1150 /* add the new */ 1151 fib_magic(RTM_NEWROUTE, 1152 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1153 prefix, ifa->ifa_prefixlen, ifa, new_metric); 1154 1155 /* delete the old */ 1156 fib_magic(RTM_DELROUTE, 1157 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1158 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority); 1159 } 1160 1161 /* Delete primary or secondary address. 1162 * Optionally, on secondary address promotion consider the addresses 1163 * from subnet iprim as deleted, even if they are in device list. 1164 * In this case the secondary ifa can be in device list. 1165 */ 1166 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 1167 { 1168 struct in_device *in_dev = ifa->ifa_dev; 1169 struct net_device *dev = in_dev->dev; 1170 struct in_ifaddr *ifa1; 1171 struct in_ifaddr *prim = ifa, *prim1 = NULL; 1172 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 1173 __be32 any = ifa->ifa_address & ifa->ifa_mask; 1174 #define LOCAL_OK 1 1175 #define BRD_OK 2 1176 #define BRD0_OK 4 1177 #define BRD1_OK 8 1178 unsigned int ok = 0; 1179 int subnet = 0; /* Primary network */ 1180 int gone = 1; /* Address is missing */ 1181 int same_prefsrc = 0; /* Another primary with same IP */ 1182 1183 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1184 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 1185 if (!prim) { 1186 /* if the device has been deleted, we don't perform 1187 * address promotion 1188 */ 1189 if (!in_dev->dead) 1190 pr_warn("%s: bug: prim == NULL\n", __func__); 1191 return; 1192 } 1193 if (iprim && iprim != prim) { 1194 pr_warn("%s: bug: iprim != prim\n", __func__); 1195 return; 1196 } 1197 } else if (!ipv4_is_zeronet(any) && 1198 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 1199 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1200 fib_magic(RTM_DELROUTE, 1201 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1202 any, ifa->ifa_prefixlen, prim, 0); 1203 subnet = 1; 1204 } 1205 1206 if (in_dev->dead) 1207 goto no_promotions; 1208 1209 /* Deletion is more complicated than add. 1210 * We should take care of not to delete too much :-) 1211 * 1212 * Scan address list to be sure that addresses are really gone. 1213 */ 1214 rcu_read_lock(); 1215 in_dev_for_each_ifa_rcu(ifa1, in_dev) { 1216 if (ifa1 == ifa) { 1217 /* promotion, keep the IP */ 1218 gone = 0; 1219 continue; 1220 } 1221 /* Ignore IFAs from our subnet */ 1222 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 1223 inet_ifa_match(ifa1->ifa_address, iprim)) 1224 continue; 1225 1226 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 1227 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 1228 /* Another address from our subnet? */ 1229 if (ifa1->ifa_mask == prim->ifa_mask && 1230 inet_ifa_match(ifa1->ifa_address, prim)) 1231 prim1 = prim; 1232 else { 1233 /* We reached the secondaries, so 1234 * same_prefsrc should be determined. 1235 */ 1236 if (!same_prefsrc) 1237 continue; 1238 /* Search new prim1 if ifa1 is not 1239 * using the current prim1 1240 */ 1241 if (!prim1 || 1242 ifa1->ifa_mask != prim1->ifa_mask || 1243 !inet_ifa_match(ifa1->ifa_address, prim1)) 1244 prim1 = inet_ifa_byprefix(in_dev, 1245 ifa1->ifa_address, 1246 ifa1->ifa_mask); 1247 if (!prim1) 1248 continue; 1249 if (prim1->ifa_local != prim->ifa_local) 1250 continue; 1251 } 1252 } else { 1253 if (prim->ifa_local != ifa1->ifa_local) 1254 continue; 1255 prim1 = ifa1; 1256 if (prim != prim1) 1257 same_prefsrc = 1; 1258 } 1259 if (ifa->ifa_local == ifa1->ifa_local) 1260 ok |= LOCAL_OK; 1261 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 1262 ok |= BRD_OK; 1263 if (brd == ifa1->ifa_broadcast) 1264 ok |= BRD1_OK; 1265 if (any == ifa1->ifa_broadcast) 1266 ok |= BRD0_OK; 1267 /* primary has network specific broadcasts */ 1268 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 1269 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 1270 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 1271 1272 if (!ipv4_is_zeronet(any1)) { 1273 if (ifa->ifa_broadcast == brd1 || 1274 ifa->ifa_broadcast == any1) 1275 ok |= BRD_OK; 1276 if (brd == brd1 || brd == any1) 1277 ok |= BRD1_OK; 1278 if (any == brd1 || any == any1) 1279 ok |= BRD0_OK; 1280 } 1281 } 1282 } 1283 rcu_read_unlock(); 1284 1285 no_promotions: 1286 if (!(ok & BRD_OK)) 1287 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1288 prim, 0); 1289 if (subnet && ifa->ifa_prefixlen < 31) { 1290 if (!(ok & BRD1_OK)) 1291 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, 1292 prim, 0); 1293 if (!(ok & BRD0_OK)) 1294 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, 1295 prim, 0); 1296 } 1297 if (!(ok & LOCAL_OK)) { 1298 unsigned int addr_type; 1299 1300 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0); 1301 1302 /* Check, that this local address finally disappeared. */ 1303 addr_type = inet_addr_type_dev_table(dev_net(dev), dev, 1304 ifa->ifa_local); 1305 if (gone && addr_type != RTN_LOCAL) { 1306 /* And the last, but not the least thing. 1307 * We must flush stray FIB entries. 1308 * 1309 * First of all, we scan fib_info list searching 1310 * for stray nexthop entries, then ignite fib_flush. 1311 */ 1312 if (fib_sync_down_addr(dev, ifa->ifa_local)) 1313 fib_flush(dev_net(dev)); 1314 } 1315 } 1316 #undef LOCAL_OK 1317 #undef BRD_OK 1318 #undef BRD0_OK 1319 #undef BRD1_OK 1320 } 1321 1322 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn) 1323 { 1324 1325 struct fib_result res; 1326 struct flowi4 fl4 = { 1327 .flowi4_mark = frn->fl_mark, 1328 .daddr = frn->fl_addr, 1329 .flowi4_tos = frn->fl_tos, 1330 .flowi4_scope = frn->fl_scope, 1331 }; 1332 struct fib_table *tb; 1333 1334 rcu_read_lock(); 1335 1336 tb = fib_get_table(net, frn->tb_id_in); 1337 1338 frn->err = -ENOENT; 1339 if (tb) { 1340 local_bh_disable(); 1341 1342 frn->tb_id = tb->tb_id; 1343 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 1344 1345 if (!frn->err) { 1346 frn->prefixlen = res.prefixlen; 1347 frn->nh_sel = res.nh_sel; 1348 frn->type = res.type; 1349 frn->scope = res.scope; 1350 } 1351 local_bh_enable(); 1352 } 1353 1354 rcu_read_unlock(); 1355 } 1356 1357 static void nl_fib_input(struct sk_buff *skb) 1358 { 1359 struct net *net; 1360 struct fib_result_nl *frn; 1361 struct nlmsghdr *nlh; 1362 u32 portid; 1363 1364 net = sock_net(skb->sk); 1365 nlh = nlmsg_hdr(skb); 1366 if (skb->len < nlmsg_total_size(sizeof(*frn)) || 1367 skb->len < nlh->nlmsg_len || 1368 nlmsg_len(nlh) < sizeof(*frn)) 1369 return; 1370 1371 skb = netlink_skb_clone(skb, GFP_KERNEL); 1372 if (!skb) 1373 return; 1374 nlh = nlmsg_hdr(skb); 1375 1376 frn = (struct fib_result_nl *) nlmsg_data(nlh); 1377 nl_fib_lookup(net, frn); 1378 1379 portid = NETLINK_CB(skb).portid; /* netlink portid */ 1380 NETLINK_CB(skb).portid = 0; /* from kernel */ 1381 NETLINK_CB(skb).dst_group = 0; /* unicast */ 1382 nlmsg_unicast(net->ipv4.fibnl, skb, portid); 1383 } 1384 1385 static int __net_init nl_fib_lookup_init(struct net *net) 1386 { 1387 struct sock *sk; 1388 struct netlink_kernel_cfg cfg = { 1389 .input = nl_fib_input, 1390 }; 1391 1392 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg); 1393 if (!sk) 1394 return -EAFNOSUPPORT; 1395 net->ipv4.fibnl = sk; 1396 return 0; 1397 } 1398 1399 static void nl_fib_lookup_exit(struct net *net) 1400 { 1401 netlink_kernel_release(net->ipv4.fibnl); 1402 net->ipv4.fibnl = NULL; 1403 } 1404 1405 static void fib_disable_ip(struct net_device *dev, unsigned long event, 1406 bool force) 1407 { 1408 if (fib_sync_down_dev(dev, event, force)) 1409 fib_flush(dev_net(dev)); 1410 else 1411 rt_cache_flush(dev_net(dev)); 1412 arp_ifdown(dev); 1413 } 1414 1415 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 1416 { 1417 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 1418 struct net_device *dev = ifa->ifa_dev->dev; 1419 struct net *net = dev_net(dev); 1420 1421 switch (event) { 1422 case NETDEV_UP: 1423 fib_add_ifaddr(ifa); 1424 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1425 fib_sync_up(dev, RTNH_F_DEAD); 1426 #endif 1427 atomic_inc(&net->ipv4.dev_addr_genid); 1428 rt_cache_flush(dev_net(dev)); 1429 break; 1430 case NETDEV_DOWN: 1431 fib_del_ifaddr(ifa, NULL); 1432 atomic_inc(&net->ipv4.dev_addr_genid); 1433 if (!ifa->ifa_dev->ifa_list) { 1434 /* Last address was deleted from this interface. 1435 * Disable IP. 1436 */ 1437 fib_disable_ip(dev, event, true); 1438 } else { 1439 rt_cache_flush(dev_net(dev)); 1440 } 1441 break; 1442 } 1443 return NOTIFY_DONE; 1444 } 1445 1446 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1447 { 1448 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1449 struct netdev_notifier_changeupper_info *upper_info = ptr; 1450 struct netdev_notifier_info_ext *info_ext = ptr; 1451 struct in_device *in_dev; 1452 struct net *net = dev_net(dev); 1453 struct in_ifaddr *ifa; 1454 unsigned int flags; 1455 1456 if (event == NETDEV_UNREGISTER) { 1457 fib_disable_ip(dev, event, true); 1458 rt_flush_dev(dev); 1459 return NOTIFY_DONE; 1460 } 1461 1462 in_dev = __in_dev_get_rtnl(dev); 1463 if (!in_dev) 1464 return NOTIFY_DONE; 1465 1466 switch (event) { 1467 case NETDEV_UP: 1468 in_dev_for_each_ifa_rtnl(ifa, in_dev) { 1469 fib_add_ifaddr(ifa); 1470 } 1471 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1472 fib_sync_up(dev, RTNH_F_DEAD); 1473 #endif 1474 atomic_inc(&net->ipv4.dev_addr_genid); 1475 rt_cache_flush(net); 1476 break; 1477 case NETDEV_DOWN: 1478 fib_disable_ip(dev, event, false); 1479 break; 1480 case NETDEV_CHANGE: 1481 flags = dev_get_flags(dev); 1482 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1483 fib_sync_up(dev, RTNH_F_LINKDOWN); 1484 else 1485 fib_sync_down_dev(dev, event, false); 1486 rt_cache_flush(net); 1487 break; 1488 case NETDEV_CHANGEMTU: 1489 fib_sync_mtu(dev, info_ext->ext.mtu); 1490 rt_cache_flush(net); 1491 break; 1492 case NETDEV_CHANGEUPPER: 1493 upper_info = ptr; 1494 /* flush all routes if dev is linked to or unlinked from 1495 * an L3 master device (e.g., VRF) 1496 */ 1497 if (upper_info->upper_dev && 1498 netif_is_l3_master(upper_info->upper_dev)) 1499 fib_disable_ip(dev, NETDEV_DOWN, true); 1500 break; 1501 } 1502 return NOTIFY_DONE; 1503 } 1504 1505 static struct notifier_block fib_inetaddr_notifier = { 1506 .notifier_call = fib_inetaddr_event, 1507 }; 1508 1509 static struct notifier_block fib_netdev_notifier = { 1510 .notifier_call = fib_netdev_event, 1511 }; 1512 1513 static int __net_init ip_fib_net_init(struct net *net) 1514 { 1515 int err; 1516 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1517 1518 err = fib4_notifier_init(net); 1519 if (err) 1520 return err; 1521 1522 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1523 /* Default to 3-tuple */ 1524 net->ipv4.sysctl_fib_multipath_hash_fields = 1525 FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK; 1526 #endif 1527 1528 /* Avoid false sharing : Use at least a full cache line */ 1529 size = max_t(size_t, size, L1_CACHE_BYTES); 1530 1531 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1532 if (!net->ipv4.fib_table_hash) { 1533 err = -ENOMEM; 1534 goto err_table_hash_alloc; 1535 } 1536 1537 err = fib4_rules_init(net); 1538 if (err < 0) 1539 goto err_rules_init; 1540 return 0; 1541 1542 err_rules_init: 1543 kfree(net->ipv4.fib_table_hash); 1544 err_table_hash_alloc: 1545 fib4_notifier_exit(net); 1546 return err; 1547 } 1548 1549 static void ip_fib_net_exit(struct net *net) 1550 { 1551 int i; 1552 1553 rtnl_lock(); 1554 #ifdef CONFIG_IP_MULTIPLE_TABLES 1555 RCU_INIT_POINTER(net->ipv4.fib_main, NULL); 1556 RCU_INIT_POINTER(net->ipv4.fib_default, NULL); 1557 #endif 1558 /* Destroy the tables in reverse order to guarantee that the 1559 * local table, ID 255, is destroyed before the main table, ID 1560 * 254. This is necessary as the local table may contain 1561 * references to data contained in the main table. 1562 */ 1563 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) { 1564 struct hlist_head *head = &net->ipv4.fib_table_hash[i]; 1565 struct hlist_node *tmp; 1566 struct fib_table *tb; 1567 1568 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) { 1569 hlist_del(&tb->tb_hlist); 1570 fib_table_flush(net, tb, true); 1571 fib_free_table(tb); 1572 } 1573 } 1574 1575 #ifdef CONFIG_IP_MULTIPLE_TABLES 1576 fib4_rules_exit(net); 1577 #endif 1578 rtnl_unlock(); 1579 kfree(net->ipv4.fib_table_hash); 1580 fib4_notifier_exit(net); 1581 } 1582 1583 static int __net_init fib_net_init(struct net *net) 1584 { 1585 int error; 1586 1587 #ifdef CONFIG_IP_ROUTE_CLASSID 1588 atomic_set(&net->ipv4.fib_num_tclassid_users, 0); 1589 #endif 1590 error = ip_fib_net_init(net); 1591 if (error < 0) 1592 goto out; 1593 error = nl_fib_lookup_init(net); 1594 if (error < 0) 1595 goto out_nlfl; 1596 error = fib_proc_init(net); 1597 if (error < 0) 1598 goto out_proc; 1599 out: 1600 return error; 1601 1602 out_proc: 1603 nl_fib_lookup_exit(net); 1604 out_nlfl: 1605 ip_fib_net_exit(net); 1606 goto out; 1607 } 1608 1609 static void __net_exit fib_net_exit(struct net *net) 1610 { 1611 fib_proc_exit(net); 1612 nl_fib_lookup_exit(net); 1613 ip_fib_net_exit(net); 1614 } 1615 1616 static struct pernet_operations fib_net_ops = { 1617 .init = fib_net_init, 1618 .exit = fib_net_exit, 1619 }; 1620 1621 void __init ip_fib_init(void) 1622 { 1623 fib_trie_init(); 1624 1625 register_pernet_subsys(&fib_net_ops); 1626 1627 register_netdevice_notifier(&fib_netdev_notifier); 1628 register_inetaddr_notifier(&fib_inetaddr_notifier); 1629 1630 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0); 1631 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0); 1632 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0); 1633 } 1634