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/inet_dscp.h> 36 #include <net/ip.h> 37 #include <net/protocol.h> 38 #include <net/route.h> 39 #include <net/tcp.h> 40 #include <net/sock.h> 41 #include <net/arp.h> 42 #include <net/ip_fib.h> 43 #include <net/nexthop.h> 44 #include <net/rtnetlink.h> 45 #include <net/xfrm.h> 46 #include <net/l3mdev.h> 47 #include <net/lwtunnel.h> 48 #include <trace/events/fib.h> 49 50 #ifndef CONFIG_IP_MULTIPLE_TABLES 51 52 static int __net_init fib4_rules_init(struct net *net) 53 { 54 struct fib_table *local_table, *main_table; 55 56 main_table = fib_trie_table(RT_TABLE_MAIN, NULL); 57 if (!main_table) 58 return -ENOMEM; 59 60 local_table = fib_trie_table(RT_TABLE_LOCAL, main_table); 61 if (!local_table) 62 goto fail; 63 64 hlist_add_head_rcu(&local_table->tb_hlist, 65 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]); 66 hlist_add_head_rcu(&main_table->tb_hlist, 67 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]); 68 return 0; 69 70 fail: 71 fib_free_table(main_table); 72 return -ENOMEM; 73 } 74 #else 75 76 struct fib_table *fib_new_table(struct net *net, u32 id) 77 { 78 struct fib_table *tb, *alias = NULL; 79 unsigned int h; 80 81 if (id == 0) 82 id = RT_TABLE_MAIN; 83 tb = fib_get_table(net, id); 84 if (tb) 85 return tb; 86 87 if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules) 88 alias = fib_new_table(net, RT_TABLE_MAIN); 89 90 tb = fib_trie_table(id, alias); 91 if (!tb) 92 return NULL; 93 94 switch (id) { 95 case RT_TABLE_MAIN: 96 rcu_assign_pointer(net->ipv4.fib_main, tb); 97 break; 98 case RT_TABLE_DEFAULT: 99 rcu_assign_pointer(net->ipv4.fib_default, tb); 100 break; 101 default: 102 break; 103 } 104 105 h = id & (FIB_TABLE_HASHSZ - 1); 106 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]); 107 return tb; 108 } 109 EXPORT_SYMBOL_GPL(fib_new_table); 110 111 /* caller must hold either rtnl or rcu read lock */ 112 struct fib_table *fib_get_table(struct net *net, u32 id) 113 { 114 struct fib_table *tb; 115 struct hlist_head *head; 116 unsigned int h; 117 118 if (id == 0) 119 id = RT_TABLE_MAIN; 120 h = id & (FIB_TABLE_HASHSZ - 1); 121 122 head = &net->ipv4.fib_table_hash[h]; 123 hlist_for_each_entry_rcu(tb, head, tb_hlist, 124 lockdep_rtnl_is_held()) { 125 if (tb->tb_id == id) 126 return tb; 127 } 128 return NULL; 129 } 130 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 131 132 static void fib_replace_table(struct net *net, struct fib_table *old, 133 struct fib_table *new) 134 { 135 #ifdef CONFIG_IP_MULTIPLE_TABLES 136 switch (new->tb_id) { 137 case RT_TABLE_MAIN: 138 rcu_assign_pointer(net->ipv4.fib_main, new); 139 break; 140 case RT_TABLE_DEFAULT: 141 rcu_assign_pointer(net->ipv4.fib_default, new); 142 break; 143 default: 144 break; 145 } 146 147 #endif 148 /* replace the old table in the hlist */ 149 hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist); 150 } 151 152 int fib_unmerge(struct net *net) 153 { 154 struct fib_table *old, *new, *main_table; 155 156 /* attempt to fetch local table if it has been allocated */ 157 old = fib_get_table(net, RT_TABLE_LOCAL); 158 if (!old) 159 return 0; 160 161 new = fib_trie_unmerge(old); 162 if (!new) 163 return -ENOMEM; 164 165 /* table is already unmerged */ 166 if (new == old) 167 return 0; 168 169 /* replace merged table with clean table */ 170 fib_replace_table(net, old, new); 171 fib_free_table(old); 172 173 /* attempt to fetch main table if it has been allocated */ 174 main_table = fib_get_table(net, RT_TABLE_MAIN); 175 if (!main_table) 176 return 0; 177 178 /* flush local entries from main table */ 179 fib_table_flush_external(main_table); 180 181 return 0; 182 } 183 184 void fib_flush(struct net *net) 185 { 186 int flushed = 0; 187 unsigned int h; 188 189 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 190 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 191 struct hlist_node *tmp; 192 struct fib_table *tb; 193 194 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) 195 flushed += fib_table_flush(net, tb, false); 196 } 197 198 if (flushed) 199 rt_cache_flush(net); 200 } 201 202 /* 203 * Find address type as if only "dev" was present in the system. If 204 * on_dev is NULL then all interfaces are taken into consideration. 205 */ 206 static inline unsigned int __inet_dev_addr_type(struct net *net, 207 const struct net_device *dev, 208 __be32 addr, u32 tb_id) 209 { 210 struct flowi4 fl4 = { .daddr = addr }; 211 struct fib_result res; 212 unsigned int ret = RTN_BROADCAST; 213 struct fib_table *table; 214 215 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr)) 216 return RTN_BROADCAST; 217 if (ipv4_is_multicast(addr)) 218 return RTN_MULTICAST; 219 220 rcu_read_lock(); 221 222 table = fib_get_table(net, tb_id); 223 if (table) { 224 ret = RTN_UNICAST; 225 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) { 226 struct fib_nh_common *nhc = fib_info_nhc(res.fi, 0); 227 228 if (!dev || dev == nhc->nhc_dev) 229 ret = res.type; 230 } 231 } 232 233 rcu_read_unlock(); 234 return ret; 235 } 236 237 unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id) 238 { 239 return __inet_dev_addr_type(net, NULL, addr, tb_id); 240 } 241 EXPORT_SYMBOL(inet_addr_type_table); 242 243 unsigned int inet_addr_type(struct net *net, __be32 addr) 244 { 245 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL); 246 } 247 EXPORT_SYMBOL(inet_addr_type); 248 249 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, 250 __be32 addr) 251 { 252 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL; 253 254 return __inet_dev_addr_type(net, dev, addr, rt_table); 255 } 256 EXPORT_SYMBOL(inet_dev_addr_type); 257 258 /* inet_addr_type with dev == NULL but using the table from a dev 259 * if one is associated 260 */ 261 unsigned int inet_addr_type_dev_table(struct net *net, 262 const struct net_device *dev, 263 __be32 addr) 264 { 265 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL; 266 267 return __inet_dev_addr_type(net, NULL, addr, rt_table); 268 } 269 EXPORT_SYMBOL(inet_addr_type_dev_table); 270 271 __be32 fib_compute_spec_dst(struct sk_buff *skb) 272 { 273 struct net_device *dev = skb->dev; 274 struct in_device *in_dev; 275 struct fib_result res; 276 struct rtable *rt; 277 struct net *net; 278 int scope; 279 280 rt = skb_rtable(skb); 281 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) == 282 RTCF_LOCAL) 283 return ip_hdr(skb)->daddr; 284 285 in_dev = __in_dev_get_rcu(dev); 286 287 net = dev_net(dev); 288 289 scope = RT_SCOPE_UNIVERSE; 290 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) { 291 bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev); 292 struct flowi4 fl4 = { 293 .flowi4_iif = LOOPBACK_IFINDEX, 294 .flowi4_oif = l3mdev_master_ifindex_rcu(dev), 295 .daddr = ip_hdr(skb)->saddr, 296 .flowi4_tos = ip_hdr(skb)->tos & IPTOS_RT_MASK, 297 .flowi4_scope = scope, 298 .flowi4_mark = vmark ? skb->mark : 0, 299 }; 300 if (!fib_lookup(net, &fl4, &res, 0)) 301 return fib_result_prefsrc(net, &res); 302 } else { 303 scope = RT_SCOPE_LINK; 304 } 305 306 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope); 307 } 308 309 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev) 310 { 311 bool dev_match = false; 312 #ifdef CONFIG_IP_ROUTE_MULTIPATH 313 if (unlikely(fi->nh)) { 314 dev_match = nexthop_uses_dev(fi->nh, dev); 315 } else { 316 int ret; 317 318 for (ret = 0; ret < fib_info_num_path(fi); ret++) { 319 const struct fib_nh_common *nhc = fib_info_nhc(fi, ret); 320 321 if (nhc_l3mdev_matches_dev(nhc, dev)) { 322 dev_match = true; 323 break; 324 } 325 } 326 } 327 #else 328 if (fib_info_nhc(fi, 0)->nhc_dev == dev) 329 dev_match = true; 330 #endif 331 332 return dev_match; 333 } 334 EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev); 335 336 /* Given (packet source, input interface) and optional (dst, oif, tos): 337 * - (main) check, that source is valid i.e. not broadcast or our local 338 * address. 339 * - figure out what "logical" interface this packet arrived 340 * and calculate "specific destination" address. 341 * - check, that packet arrived from expected physical interface. 342 * called with rcu_read_lock() 343 */ 344 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 345 u8 tos, int oif, struct net_device *dev, 346 int rpf, struct in_device *idev, u32 *itag) 347 { 348 struct net *net = dev_net(dev); 349 struct flow_keys flkeys; 350 int ret, no_addr; 351 struct fib_result res; 352 struct flowi4 fl4; 353 bool dev_match; 354 355 fl4.flowi4_oif = 0; 356 fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev); 357 if (!fl4.flowi4_iif) 358 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX; 359 fl4.daddr = src; 360 fl4.saddr = dst; 361 fl4.flowi4_tos = tos; 362 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 363 fl4.flowi4_tun_key.tun_id = 0; 364 fl4.flowi4_flags = 0; 365 fl4.flowi4_uid = sock_net_uid(net, NULL); 366 fl4.flowi4_multipath_hash = 0; 367 368 no_addr = idev->ifa_list == NULL; 369 370 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0; 371 if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) { 372 fl4.flowi4_proto = 0; 373 fl4.fl4_sport = 0; 374 fl4.fl4_dport = 0; 375 } else { 376 swap(fl4.fl4_sport, fl4.fl4_dport); 377 } 378 379 if (fib_lookup(net, &fl4, &res, 0)) 380 goto last_resort; 381 if (res.type != RTN_UNICAST && 382 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev))) 383 goto e_inval; 384 fib_combine_itag(itag, &res); 385 386 dev_match = fib_info_nh_uses_dev(res.fi, dev); 387 /* This is not common, loopback packets retain skb_dst so normally they 388 * would not even hit this slow path. 389 */ 390 dev_match = dev_match || (res.type == RTN_LOCAL && 391 dev == net->loopback_dev); 392 if (dev_match) { 393 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; 394 return ret; 395 } 396 if (no_addr) 397 goto last_resort; 398 if (rpf == 1) 399 goto e_rpf; 400 fl4.flowi4_oif = dev->ifindex; 401 402 ret = 0; 403 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) { 404 if (res.type == RTN_UNICAST) 405 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; 406 } 407 return ret; 408 409 last_resort: 410 if (rpf) 411 goto e_rpf; 412 *itag = 0; 413 return 0; 414 415 e_inval: 416 return -EINVAL; 417 e_rpf: 418 return -EXDEV; 419 } 420 421 /* Ignore rp_filter for packets protected by IPsec. */ 422 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 423 u8 tos, int oif, struct net_device *dev, 424 struct in_device *idev, u32 *itag) 425 { 426 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev); 427 struct net *net = dev_net(dev); 428 429 if (!r && !fib_num_tclassid_users(net) && 430 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) { 431 if (IN_DEV_ACCEPT_LOCAL(idev)) 432 goto ok; 433 /* with custom local routes in place, checking local addresses 434 * only will be too optimistic, with custom rules, checking 435 * local addresses only can be too strict, e.g. due to vrf 436 */ 437 if (net->ipv4.fib_has_custom_local_routes || 438 fib4_has_custom_rules(net)) 439 goto full_check; 440 if (inet_lookup_ifaddr_rcu(net, src)) 441 return -EINVAL; 442 443 ok: 444 *itag = 0; 445 return 0; 446 } 447 448 full_check: 449 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag); 450 } 451 452 static inline __be32 sk_extract_addr(struct sockaddr *addr) 453 { 454 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 455 } 456 457 static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 458 { 459 struct nlattr *nla; 460 461 nla = (struct nlattr *) ((char *) mx + len); 462 nla->nla_type = type; 463 nla->nla_len = nla_attr_size(4); 464 *(u32 *) nla_data(nla) = value; 465 466 return len + nla_total_size(4); 467 } 468 469 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 470 struct fib_config *cfg) 471 { 472 __be32 addr; 473 int plen; 474 475 memset(cfg, 0, sizeof(*cfg)); 476 cfg->fc_nlinfo.nl_net = net; 477 478 if (rt->rt_dst.sa_family != AF_INET) 479 return -EAFNOSUPPORT; 480 481 /* 482 * Check mask for validity: 483 * a) it must be contiguous. 484 * b) destination must have all host bits clear. 485 * c) if application forgot to set correct family (AF_INET), 486 * reject request unless it is absolutely clear i.e. 487 * both family and mask are zero. 488 */ 489 plen = 32; 490 addr = sk_extract_addr(&rt->rt_dst); 491 if (!(rt->rt_flags & RTF_HOST)) { 492 __be32 mask = sk_extract_addr(&rt->rt_genmask); 493 494 if (rt->rt_genmask.sa_family != AF_INET) { 495 if (mask || rt->rt_genmask.sa_family) 496 return -EAFNOSUPPORT; 497 } 498 499 if (bad_mask(mask, addr)) 500 return -EINVAL; 501 502 plen = inet_mask_len(mask); 503 } 504 505 cfg->fc_dst_len = plen; 506 cfg->fc_dst = addr; 507 508 if (cmd != SIOCDELRT) { 509 cfg->fc_nlflags = NLM_F_CREATE; 510 cfg->fc_protocol = RTPROT_BOOT; 511 } 512 513 if (rt->rt_metric) 514 cfg->fc_priority = rt->rt_metric - 1; 515 516 if (rt->rt_flags & RTF_REJECT) { 517 cfg->fc_scope = RT_SCOPE_HOST; 518 cfg->fc_type = RTN_UNREACHABLE; 519 return 0; 520 } 521 522 cfg->fc_scope = RT_SCOPE_NOWHERE; 523 cfg->fc_type = RTN_UNICAST; 524 525 if (rt->rt_dev) { 526 char *colon; 527 struct net_device *dev; 528 char devname[IFNAMSIZ]; 529 530 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 531 return -EFAULT; 532 533 devname[IFNAMSIZ-1] = 0; 534 colon = strchr(devname, ':'); 535 if (colon) 536 *colon = 0; 537 dev = __dev_get_by_name(net, devname); 538 if (!dev) 539 return -ENODEV; 540 cfg->fc_oif = dev->ifindex; 541 cfg->fc_table = l3mdev_fib_table(dev); 542 if (colon) { 543 const struct in_ifaddr *ifa; 544 struct in_device *in_dev; 545 546 in_dev = __in_dev_get_rtnl(dev); 547 if (!in_dev) 548 return -ENODEV; 549 550 *colon = ':'; 551 552 rcu_read_lock(); 553 in_dev_for_each_ifa_rcu(ifa, in_dev) { 554 if (strcmp(ifa->ifa_label, devname) == 0) 555 break; 556 } 557 rcu_read_unlock(); 558 559 if (!ifa) 560 return -ENODEV; 561 cfg->fc_prefsrc = ifa->ifa_local; 562 } 563 } 564 565 addr = sk_extract_addr(&rt->rt_gateway); 566 if (rt->rt_gateway.sa_family == AF_INET && addr) { 567 unsigned int addr_type; 568 569 cfg->fc_gw4 = addr; 570 cfg->fc_gw_family = AF_INET; 571 addr_type = inet_addr_type_table(net, addr, cfg->fc_table); 572 if (rt->rt_flags & RTF_GATEWAY && 573 addr_type == RTN_UNICAST) 574 cfg->fc_scope = RT_SCOPE_UNIVERSE; 575 } 576 577 if (cmd == SIOCDELRT) 578 return 0; 579 580 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family) 581 return -EINVAL; 582 583 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 584 cfg->fc_scope = RT_SCOPE_LINK; 585 586 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 587 struct nlattr *mx; 588 int len = 0; 589 590 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL); 591 if (!mx) 592 return -ENOMEM; 593 594 if (rt->rt_flags & RTF_MTU) 595 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 596 597 if (rt->rt_flags & RTF_WINDOW) 598 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 599 600 if (rt->rt_flags & RTF_IRTT) 601 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 602 603 cfg->fc_mx = mx; 604 cfg->fc_mx_len = len; 605 } 606 607 return 0; 608 } 609 610 /* 611 * Handle IP routing ioctl calls. 612 * These are used to manipulate the routing tables 613 */ 614 int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt) 615 { 616 struct fib_config cfg; 617 int err; 618 619 switch (cmd) { 620 case SIOCADDRT: /* Add a route */ 621 case SIOCDELRT: /* Delete a route */ 622 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 623 return -EPERM; 624 625 rtnl_lock(); 626 err = rtentry_to_fib_config(net, cmd, rt, &cfg); 627 if (err == 0) { 628 struct fib_table *tb; 629 630 if (cmd == SIOCDELRT) { 631 tb = fib_get_table(net, cfg.fc_table); 632 if (tb) 633 err = fib_table_delete(net, tb, &cfg, 634 NULL); 635 else 636 err = -ESRCH; 637 } else { 638 tb = fib_new_table(net, cfg.fc_table); 639 if (tb) 640 err = fib_table_insert(net, tb, 641 &cfg, NULL); 642 else 643 err = -ENOBUFS; 644 } 645 646 /* allocated by rtentry_to_fib_config() */ 647 kfree(cfg.fc_mx); 648 } 649 rtnl_unlock(); 650 return err; 651 } 652 return -EINVAL; 653 } 654 655 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 656 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 }, 657 [RTA_DST] = { .type = NLA_U32 }, 658 [RTA_SRC] = { .type = NLA_U32 }, 659 [RTA_IIF] = { .type = NLA_U32 }, 660 [RTA_OIF] = { .type = NLA_U32 }, 661 [RTA_GATEWAY] = { .type = NLA_U32 }, 662 [RTA_PRIORITY] = { .type = NLA_U32 }, 663 [RTA_PREFSRC] = { .type = NLA_U32 }, 664 [RTA_METRICS] = { .type = NLA_NESTED }, 665 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 666 [RTA_FLOW] = { .type = NLA_U32 }, 667 [RTA_ENCAP_TYPE] = { .type = NLA_U16 }, 668 [RTA_ENCAP] = { .type = NLA_NESTED }, 669 [RTA_UID] = { .type = NLA_U32 }, 670 [RTA_MARK] = { .type = NLA_U32 }, 671 [RTA_TABLE] = { .type = NLA_U32 }, 672 [RTA_IP_PROTO] = { .type = NLA_U8 }, 673 [RTA_SPORT] = { .type = NLA_U16 }, 674 [RTA_DPORT] = { .type = NLA_U16 }, 675 [RTA_NH_ID] = { .type = NLA_U32 }, 676 }; 677 678 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, 679 struct netlink_ext_ack *extack) 680 { 681 struct rtvia *via; 682 int alen; 683 684 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) { 685 NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA"); 686 return -EINVAL; 687 } 688 689 via = nla_data(nla); 690 alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr); 691 692 switch (via->rtvia_family) { 693 case AF_INET: 694 if (alen != sizeof(__be32)) { 695 NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA"); 696 return -EINVAL; 697 } 698 cfg->fc_gw_family = AF_INET; 699 cfg->fc_gw4 = *((__be32 *)via->rtvia_addr); 700 break; 701 case AF_INET6: 702 #if IS_ENABLED(CONFIG_IPV6) 703 if (alen != sizeof(struct in6_addr)) { 704 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA"); 705 return -EINVAL; 706 } 707 cfg->fc_gw_family = AF_INET6; 708 cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr); 709 #else 710 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel"); 711 return -EINVAL; 712 #endif 713 break; 714 default: 715 NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA"); 716 return -EINVAL; 717 } 718 719 return 0; 720 } 721 722 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 723 struct nlmsghdr *nlh, struct fib_config *cfg, 724 struct netlink_ext_ack *extack) 725 { 726 bool has_gw = false, has_via = false; 727 struct nlattr *attr; 728 int err, remaining; 729 struct rtmsg *rtm; 730 731 err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX, 732 rtm_ipv4_policy, extack); 733 if (err < 0) 734 goto errout; 735 736 memset(cfg, 0, sizeof(*cfg)); 737 738 rtm = nlmsg_data(nlh); 739 740 if (!inet_validate_dscp(rtm->rtm_tos)) { 741 NL_SET_ERR_MSG(extack, 742 "Invalid dsfield (tos): ECN bits must be 0"); 743 err = -EINVAL; 744 goto errout; 745 } 746 cfg->fc_dscp = inet_dsfield_to_dscp(rtm->rtm_tos); 747 748 cfg->fc_dst_len = rtm->rtm_dst_len; 749 cfg->fc_table = rtm->rtm_table; 750 cfg->fc_protocol = rtm->rtm_protocol; 751 cfg->fc_scope = rtm->rtm_scope; 752 cfg->fc_type = rtm->rtm_type; 753 cfg->fc_flags = rtm->rtm_flags; 754 cfg->fc_nlflags = nlh->nlmsg_flags; 755 756 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid; 757 cfg->fc_nlinfo.nlh = nlh; 758 cfg->fc_nlinfo.nl_net = net; 759 760 if (cfg->fc_type > RTN_MAX) { 761 NL_SET_ERR_MSG(extack, "Invalid route type"); 762 err = -EINVAL; 763 goto errout; 764 } 765 766 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 767 switch (nla_type(attr)) { 768 case RTA_DST: 769 cfg->fc_dst = nla_get_be32(attr); 770 break; 771 case RTA_OIF: 772 cfg->fc_oif = nla_get_u32(attr); 773 break; 774 case RTA_GATEWAY: 775 has_gw = true; 776 cfg->fc_gw4 = nla_get_be32(attr); 777 if (cfg->fc_gw4) 778 cfg->fc_gw_family = AF_INET; 779 break; 780 case RTA_VIA: 781 has_via = true; 782 err = fib_gw_from_via(cfg, attr, extack); 783 if (err) 784 goto errout; 785 break; 786 case RTA_PRIORITY: 787 cfg->fc_priority = nla_get_u32(attr); 788 break; 789 case RTA_PREFSRC: 790 cfg->fc_prefsrc = nla_get_be32(attr); 791 break; 792 case RTA_METRICS: 793 cfg->fc_mx = nla_data(attr); 794 cfg->fc_mx_len = nla_len(attr); 795 break; 796 case RTA_MULTIPATH: 797 err = lwtunnel_valid_encap_type_attr(nla_data(attr), 798 nla_len(attr), 799 extack); 800 if (err < 0) 801 goto errout; 802 cfg->fc_mp = nla_data(attr); 803 cfg->fc_mp_len = nla_len(attr); 804 break; 805 case RTA_FLOW: 806 cfg->fc_flow = nla_get_u32(attr); 807 break; 808 case RTA_TABLE: 809 cfg->fc_table = nla_get_u32(attr); 810 break; 811 case RTA_ENCAP: 812 cfg->fc_encap = attr; 813 break; 814 case RTA_ENCAP_TYPE: 815 cfg->fc_encap_type = nla_get_u16(attr); 816 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, 817 extack); 818 if (err < 0) 819 goto errout; 820 break; 821 case RTA_NH_ID: 822 cfg->fc_nh_id = nla_get_u32(attr); 823 break; 824 } 825 } 826 827 if (cfg->fc_nh_id) { 828 if (cfg->fc_oif || cfg->fc_gw_family || 829 cfg->fc_encap || cfg->fc_mp) { 830 NL_SET_ERR_MSG(extack, 831 "Nexthop specification and nexthop id are mutually exclusive"); 832 return -EINVAL; 833 } 834 } 835 836 if (has_gw && has_via) { 837 NL_SET_ERR_MSG(extack, 838 "Nexthop configuration can not contain both GATEWAY and VIA"); 839 return -EINVAL; 840 } 841 842 return 0; 843 errout: 844 return err; 845 } 846 847 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, 848 struct netlink_ext_ack *extack) 849 { 850 struct net *net = sock_net(skb->sk); 851 struct fib_config cfg; 852 struct fib_table *tb; 853 int err; 854 855 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 856 if (err < 0) 857 goto errout; 858 859 if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) { 860 NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); 861 err = -EINVAL; 862 goto errout; 863 } 864 865 tb = fib_get_table(net, cfg.fc_table); 866 if (!tb) { 867 NL_SET_ERR_MSG(extack, "FIB table does not exist"); 868 err = -ESRCH; 869 goto errout; 870 } 871 872 err = fib_table_delete(net, tb, &cfg, extack); 873 errout: 874 return err; 875 } 876 877 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, 878 struct netlink_ext_ack *extack) 879 { 880 struct net *net = sock_net(skb->sk); 881 struct fib_config cfg; 882 struct fib_table *tb; 883 int err; 884 885 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 886 if (err < 0) 887 goto errout; 888 889 tb = fib_new_table(net, cfg.fc_table); 890 if (!tb) { 891 err = -ENOBUFS; 892 goto errout; 893 } 894 895 err = fib_table_insert(net, tb, &cfg, extack); 896 if (!err && cfg.fc_type == RTN_LOCAL) 897 net->ipv4.fib_has_custom_local_routes = true; 898 errout: 899 return err; 900 } 901 902 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 903 struct fib_dump_filter *filter, 904 struct netlink_callback *cb) 905 { 906 struct netlink_ext_ack *extack = cb->extack; 907 struct nlattr *tb[RTA_MAX + 1]; 908 struct rtmsg *rtm; 909 int err, i; 910 911 ASSERT_RTNL(); 912 913 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 914 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request"); 915 return -EINVAL; 916 } 917 918 rtm = nlmsg_data(nlh); 919 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos || 920 rtm->rtm_scope) { 921 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request"); 922 return -EINVAL; 923 } 924 925 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) { 926 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request"); 927 return -EINVAL; 928 } 929 if (rtm->rtm_flags & RTM_F_CLONED) 930 filter->dump_routes = false; 931 else 932 filter->dump_exceptions = false; 933 934 filter->flags = rtm->rtm_flags; 935 filter->protocol = rtm->rtm_protocol; 936 filter->rt_type = rtm->rtm_type; 937 filter->table_id = rtm->rtm_table; 938 939 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 940 rtm_ipv4_policy, extack); 941 if (err < 0) 942 return err; 943 944 for (i = 0; i <= RTA_MAX; ++i) { 945 int ifindex; 946 947 if (!tb[i]) 948 continue; 949 950 switch (i) { 951 case RTA_TABLE: 952 filter->table_id = nla_get_u32(tb[i]); 953 break; 954 case RTA_OIF: 955 ifindex = nla_get_u32(tb[i]); 956 filter->dev = __dev_get_by_index(net, ifindex); 957 if (!filter->dev) 958 return -ENODEV; 959 break; 960 default: 961 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request"); 962 return -EINVAL; 963 } 964 } 965 966 if (filter->flags || filter->protocol || filter->rt_type || 967 filter->table_id || filter->dev) { 968 filter->filter_set = 1; 969 cb->answer_flags = NLM_F_DUMP_FILTERED; 970 } 971 972 return 0; 973 } 974 EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req); 975 976 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 977 { 978 struct fib_dump_filter filter = { .dump_routes = true, 979 .dump_exceptions = true }; 980 const struct nlmsghdr *nlh = cb->nlh; 981 struct net *net = sock_net(skb->sk); 982 unsigned int h, s_h; 983 unsigned int e = 0, s_e; 984 struct fib_table *tb; 985 struct hlist_head *head; 986 int dumped = 0, err; 987 988 if (cb->strict_check) { 989 err = ip_valid_fib_dump_req(net, nlh, &filter, cb); 990 if (err < 0) 991 return err; 992 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 993 struct rtmsg *rtm = nlmsg_data(nlh); 994 995 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED); 996 } 997 998 /* ipv4 does not use prefix flag */ 999 if (filter.flags & RTM_F_PREFIX) 1000 return skb->len; 1001 1002 if (filter.table_id) { 1003 tb = fib_get_table(net, filter.table_id); 1004 if (!tb) { 1005 if (rtnl_msg_family(cb->nlh) != PF_INET) 1006 return skb->len; 1007 1008 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist"); 1009 return -ENOENT; 1010 } 1011 1012 rcu_read_lock(); 1013 err = fib_table_dump(tb, skb, cb, &filter); 1014 rcu_read_unlock(); 1015 return skb->len ? : err; 1016 } 1017 1018 s_h = cb->args[0]; 1019 s_e = cb->args[1]; 1020 1021 rcu_read_lock(); 1022 1023 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 1024 e = 0; 1025 head = &net->ipv4.fib_table_hash[h]; 1026 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 1027 if (e < s_e) 1028 goto next; 1029 if (dumped) 1030 memset(&cb->args[2], 0, sizeof(cb->args) - 1031 2 * sizeof(cb->args[0])); 1032 err = fib_table_dump(tb, skb, cb, &filter); 1033 if (err < 0) { 1034 if (likely(skb->len)) 1035 goto out; 1036 1037 goto out_err; 1038 } 1039 dumped = 1; 1040 next: 1041 e++; 1042 } 1043 } 1044 out: 1045 err = skb->len; 1046 out_err: 1047 rcu_read_unlock(); 1048 1049 cb->args[1] = e; 1050 cb->args[0] = h; 1051 1052 return err; 1053 } 1054 1055 /* Prepare and feed intra-kernel routing request. 1056 * Really, it should be netlink message, but :-( netlink 1057 * can be not configured, so that we feed it directly 1058 * to fib engine. It is legal, because all events occur 1059 * only when netlink is already locked. 1060 */ 1061 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, 1062 struct in_ifaddr *ifa, u32 rt_priority) 1063 { 1064 struct net *net = dev_net(ifa->ifa_dev->dev); 1065 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev); 1066 struct fib_table *tb; 1067 struct fib_config cfg = { 1068 .fc_protocol = RTPROT_KERNEL, 1069 .fc_type = type, 1070 .fc_dst = dst, 1071 .fc_dst_len = dst_len, 1072 .fc_priority = rt_priority, 1073 .fc_prefsrc = ifa->ifa_local, 1074 .fc_oif = ifa->ifa_dev->dev->ifindex, 1075 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 1076 .fc_nlinfo = { 1077 .nl_net = net, 1078 }, 1079 }; 1080 1081 if (!tb_id) 1082 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL; 1083 1084 tb = fib_new_table(net, tb_id); 1085 if (!tb) 1086 return; 1087 1088 cfg.fc_table = tb->tb_id; 1089 1090 if (type != RTN_LOCAL) 1091 cfg.fc_scope = RT_SCOPE_LINK; 1092 else 1093 cfg.fc_scope = RT_SCOPE_HOST; 1094 1095 if (cmd == RTM_NEWROUTE) 1096 fib_table_insert(net, tb, &cfg, NULL); 1097 else 1098 fib_table_delete(net, tb, &cfg, NULL); 1099 } 1100 1101 void fib_add_ifaddr(struct in_ifaddr *ifa) 1102 { 1103 struct in_device *in_dev = ifa->ifa_dev; 1104 struct net_device *dev = in_dev->dev; 1105 struct in_ifaddr *prim = ifa; 1106 __be32 mask = ifa->ifa_mask; 1107 __be32 addr = ifa->ifa_local; 1108 __be32 prefix = ifa->ifa_address & mask; 1109 1110 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1111 prim = inet_ifa_byprefix(in_dev, prefix, mask); 1112 if (!prim) { 1113 pr_warn("%s: bug: prim == NULL\n", __func__); 1114 return; 1115 } 1116 } 1117 1118 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0); 1119 1120 if (!(dev->flags & IFF_UP)) 1121 return; 1122 1123 /* Add broadcast address, if it is explicitly assigned. */ 1124 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 1125 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1126 prim, 0); 1127 1128 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 1129 (prefix != addr || ifa->ifa_prefixlen < 32)) { 1130 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1131 fib_magic(RTM_NEWROUTE, 1132 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1133 prefix, ifa->ifa_prefixlen, prim, 1134 ifa->ifa_rt_priority); 1135 1136 /* Add the network broadcast address, when it makes sense */ 1137 if (ifa->ifa_prefixlen < 31) { 1138 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 1139 32, prim, 0); 1140 } 1141 } 1142 } 1143 1144 void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric) 1145 { 1146 __be32 prefix = ifa->ifa_address & ifa->ifa_mask; 1147 struct in_device *in_dev = ifa->ifa_dev; 1148 struct net_device *dev = in_dev->dev; 1149 1150 if (!(dev->flags & IFF_UP) || 1151 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) || 1152 ipv4_is_zeronet(prefix) || 1153 (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32)) 1154 return; 1155 1156 /* add the new */ 1157 fib_magic(RTM_NEWROUTE, 1158 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1159 prefix, ifa->ifa_prefixlen, ifa, new_metric); 1160 1161 /* delete the old */ 1162 fib_magic(RTM_DELROUTE, 1163 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1164 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority); 1165 } 1166 1167 /* Delete primary or secondary address. 1168 * Optionally, on secondary address promotion consider the addresses 1169 * from subnet iprim as deleted, even if they are in device list. 1170 * In this case the secondary ifa can be in device list. 1171 */ 1172 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 1173 { 1174 struct in_device *in_dev = ifa->ifa_dev; 1175 struct net_device *dev = in_dev->dev; 1176 struct in_ifaddr *ifa1; 1177 struct in_ifaddr *prim = ifa, *prim1 = NULL; 1178 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 1179 __be32 any = ifa->ifa_address & ifa->ifa_mask; 1180 #define LOCAL_OK 1 1181 #define BRD_OK 2 1182 #define BRD0_OK 4 1183 #define BRD1_OK 8 1184 unsigned int ok = 0; 1185 int subnet = 0; /* Primary network */ 1186 int gone = 1; /* Address is missing */ 1187 int same_prefsrc = 0; /* Another primary with same IP */ 1188 1189 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1190 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 1191 if (!prim) { 1192 /* if the device has been deleted, we don't perform 1193 * address promotion 1194 */ 1195 if (!in_dev->dead) 1196 pr_warn("%s: bug: prim == NULL\n", __func__); 1197 return; 1198 } 1199 if (iprim && iprim != prim) { 1200 pr_warn("%s: bug: iprim != prim\n", __func__); 1201 return; 1202 } 1203 } else if (!ipv4_is_zeronet(any) && 1204 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 1205 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1206 fib_magic(RTM_DELROUTE, 1207 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1208 any, ifa->ifa_prefixlen, prim, 0); 1209 subnet = 1; 1210 } 1211 1212 if (in_dev->dead) 1213 goto no_promotions; 1214 1215 /* Deletion is more complicated than add. 1216 * We should take care of not to delete too much :-) 1217 * 1218 * Scan address list to be sure that addresses are really gone. 1219 */ 1220 rcu_read_lock(); 1221 in_dev_for_each_ifa_rcu(ifa1, in_dev) { 1222 if (ifa1 == ifa) { 1223 /* promotion, keep the IP */ 1224 gone = 0; 1225 continue; 1226 } 1227 /* Ignore IFAs from our subnet */ 1228 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 1229 inet_ifa_match(ifa1->ifa_address, iprim)) 1230 continue; 1231 1232 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 1233 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 1234 /* Another address from our subnet? */ 1235 if (ifa1->ifa_mask == prim->ifa_mask && 1236 inet_ifa_match(ifa1->ifa_address, prim)) 1237 prim1 = prim; 1238 else { 1239 /* We reached the secondaries, so 1240 * same_prefsrc should be determined. 1241 */ 1242 if (!same_prefsrc) 1243 continue; 1244 /* Search new prim1 if ifa1 is not 1245 * using the current prim1 1246 */ 1247 if (!prim1 || 1248 ifa1->ifa_mask != prim1->ifa_mask || 1249 !inet_ifa_match(ifa1->ifa_address, prim1)) 1250 prim1 = inet_ifa_byprefix(in_dev, 1251 ifa1->ifa_address, 1252 ifa1->ifa_mask); 1253 if (!prim1) 1254 continue; 1255 if (prim1->ifa_local != prim->ifa_local) 1256 continue; 1257 } 1258 } else { 1259 if (prim->ifa_local != ifa1->ifa_local) 1260 continue; 1261 prim1 = ifa1; 1262 if (prim != prim1) 1263 same_prefsrc = 1; 1264 } 1265 if (ifa->ifa_local == ifa1->ifa_local) 1266 ok |= LOCAL_OK; 1267 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 1268 ok |= BRD_OK; 1269 if (brd == ifa1->ifa_broadcast) 1270 ok |= BRD1_OK; 1271 if (any == ifa1->ifa_broadcast) 1272 ok |= BRD0_OK; 1273 /* primary has network specific broadcasts */ 1274 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 1275 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 1276 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 1277 1278 if (!ipv4_is_zeronet(any1)) { 1279 if (ifa->ifa_broadcast == brd1 || 1280 ifa->ifa_broadcast == any1) 1281 ok |= BRD_OK; 1282 if (brd == brd1 || brd == any1) 1283 ok |= BRD1_OK; 1284 if (any == brd1 || any == any1) 1285 ok |= BRD0_OK; 1286 } 1287 } 1288 } 1289 rcu_read_unlock(); 1290 1291 no_promotions: 1292 if (!(ok & BRD_OK)) 1293 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1294 prim, 0); 1295 if (subnet && ifa->ifa_prefixlen < 31) { 1296 if (!(ok & BRD1_OK)) 1297 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, 1298 prim, 0); 1299 if (!(ok & BRD0_OK)) 1300 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, 1301 prim, 0); 1302 } 1303 if (!(ok & LOCAL_OK)) { 1304 unsigned int addr_type; 1305 1306 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0); 1307 1308 /* Check, that this local address finally disappeared. */ 1309 addr_type = inet_addr_type_dev_table(dev_net(dev), dev, 1310 ifa->ifa_local); 1311 if (gone && addr_type != RTN_LOCAL) { 1312 /* And the last, but not the least thing. 1313 * We must flush stray FIB entries. 1314 * 1315 * First of all, we scan fib_info list searching 1316 * for stray nexthop entries, then ignite fib_flush. 1317 */ 1318 if (fib_sync_down_addr(dev, ifa->ifa_local)) 1319 fib_flush(dev_net(dev)); 1320 } 1321 } 1322 #undef LOCAL_OK 1323 #undef BRD_OK 1324 #undef BRD0_OK 1325 #undef BRD1_OK 1326 } 1327 1328 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn) 1329 { 1330 1331 struct fib_result res; 1332 struct flowi4 fl4 = { 1333 .flowi4_mark = frn->fl_mark, 1334 .daddr = frn->fl_addr, 1335 .flowi4_tos = frn->fl_tos, 1336 .flowi4_scope = frn->fl_scope, 1337 }; 1338 struct fib_table *tb; 1339 1340 rcu_read_lock(); 1341 1342 tb = fib_get_table(net, frn->tb_id_in); 1343 1344 frn->err = -ENOENT; 1345 if (tb) { 1346 local_bh_disable(); 1347 1348 frn->tb_id = tb->tb_id; 1349 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 1350 1351 if (!frn->err) { 1352 frn->prefixlen = res.prefixlen; 1353 frn->nh_sel = res.nh_sel; 1354 frn->type = res.type; 1355 frn->scope = res.scope; 1356 } 1357 local_bh_enable(); 1358 } 1359 1360 rcu_read_unlock(); 1361 } 1362 1363 static void nl_fib_input(struct sk_buff *skb) 1364 { 1365 struct net *net; 1366 struct fib_result_nl *frn; 1367 struct nlmsghdr *nlh; 1368 u32 portid; 1369 1370 net = sock_net(skb->sk); 1371 nlh = nlmsg_hdr(skb); 1372 if (skb->len < nlmsg_total_size(sizeof(*frn)) || 1373 skb->len < nlh->nlmsg_len || 1374 nlmsg_len(nlh) < sizeof(*frn)) 1375 return; 1376 1377 skb = netlink_skb_clone(skb, GFP_KERNEL); 1378 if (!skb) 1379 return; 1380 nlh = nlmsg_hdr(skb); 1381 1382 frn = (struct fib_result_nl *) nlmsg_data(nlh); 1383 nl_fib_lookup(net, frn); 1384 1385 portid = NETLINK_CB(skb).portid; /* netlink portid */ 1386 NETLINK_CB(skb).portid = 0; /* from kernel */ 1387 NETLINK_CB(skb).dst_group = 0; /* unicast */ 1388 nlmsg_unicast(net->ipv4.fibnl, skb, portid); 1389 } 1390 1391 static int __net_init nl_fib_lookup_init(struct net *net) 1392 { 1393 struct sock *sk; 1394 struct netlink_kernel_cfg cfg = { 1395 .input = nl_fib_input, 1396 }; 1397 1398 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg); 1399 if (!sk) 1400 return -EAFNOSUPPORT; 1401 net->ipv4.fibnl = sk; 1402 return 0; 1403 } 1404 1405 static void nl_fib_lookup_exit(struct net *net) 1406 { 1407 netlink_kernel_release(net->ipv4.fibnl); 1408 net->ipv4.fibnl = NULL; 1409 } 1410 1411 static void fib_disable_ip(struct net_device *dev, unsigned long event, 1412 bool force) 1413 { 1414 if (fib_sync_down_dev(dev, event, force)) 1415 fib_flush(dev_net(dev)); 1416 else 1417 rt_cache_flush(dev_net(dev)); 1418 arp_ifdown(dev); 1419 } 1420 1421 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 1422 { 1423 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 1424 struct net_device *dev = ifa->ifa_dev->dev; 1425 struct net *net = dev_net(dev); 1426 1427 switch (event) { 1428 case NETDEV_UP: 1429 fib_add_ifaddr(ifa); 1430 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1431 fib_sync_up(dev, RTNH_F_DEAD); 1432 #endif 1433 atomic_inc(&net->ipv4.dev_addr_genid); 1434 rt_cache_flush(dev_net(dev)); 1435 break; 1436 case NETDEV_DOWN: 1437 fib_del_ifaddr(ifa, NULL); 1438 atomic_inc(&net->ipv4.dev_addr_genid); 1439 if (!ifa->ifa_dev->ifa_list) { 1440 /* Last address was deleted from this interface. 1441 * Disable IP. 1442 */ 1443 fib_disable_ip(dev, event, true); 1444 } else { 1445 rt_cache_flush(dev_net(dev)); 1446 } 1447 break; 1448 } 1449 return NOTIFY_DONE; 1450 } 1451 1452 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1453 { 1454 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1455 struct netdev_notifier_changeupper_info *upper_info = ptr; 1456 struct netdev_notifier_info_ext *info_ext = ptr; 1457 struct in_device *in_dev; 1458 struct net *net = dev_net(dev); 1459 struct in_ifaddr *ifa; 1460 unsigned int flags; 1461 1462 if (event == NETDEV_UNREGISTER) { 1463 fib_disable_ip(dev, event, true); 1464 rt_flush_dev(dev); 1465 return NOTIFY_DONE; 1466 } 1467 1468 in_dev = __in_dev_get_rtnl(dev); 1469 if (!in_dev) 1470 return NOTIFY_DONE; 1471 1472 switch (event) { 1473 case NETDEV_UP: 1474 in_dev_for_each_ifa_rtnl(ifa, in_dev) { 1475 fib_add_ifaddr(ifa); 1476 } 1477 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1478 fib_sync_up(dev, RTNH_F_DEAD); 1479 #endif 1480 atomic_inc(&net->ipv4.dev_addr_genid); 1481 rt_cache_flush(net); 1482 break; 1483 case NETDEV_DOWN: 1484 fib_disable_ip(dev, event, false); 1485 break; 1486 case NETDEV_CHANGE: 1487 flags = dev_get_flags(dev); 1488 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1489 fib_sync_up(dev, RTNH_F_LINKDOWN); 1490 else 1491 fib_sync_down_dev(dev, event, false); 1492 rt_cache_flush(net); 1493 break; 1494 case NETDEV_CHANGEMTU: 1495 fib_sync_mtu(dev, info_ext->ext.mtu); 1496 rt_cache_flush(net); 1497 break; 1498 case NETDEV_CHANGEUPPER: 1499 upper_info = ptr; 1500 /* flush all routes if dev is linked to or unlinked from 1501 * an L3 master device (e.g., VRF) 1502 */ 1503 if (upper_info->upper_dev && 1504 netif_is_l3_master(upper_info->upper_dev)) 1505 fib_disable_ip(dev, NETDEV_DOWN, true); 1506 break; 1507 } 1508 return NOTIFY_DONE; 1509 } 1510 1511 static struct notifier_block fib_inetaddr_notifier = { 1512 .notifier_call = fib_inetaddr_event, 1513 }; 1514 1515 static struct notifier_block fib_netdev_notifier = { 1516 .notifier_call = fib_netdev_event, 1517 }; 1518 1519 static int __net_init ip_fib_net_init(struct net *net) 1520 { 1521 int err; 1522 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1523 1524 err = fib4_notifier_init(net); 1525 if (err) 1526 return err; 1527 1528 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1529 /* Default to 3-tuple */ 1530 net->ipv4.sysctl_fib_multipath_hash_fields = 1531 FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK; 1532 #endif 1533 1534 /* Avoid false sharing : Use at least a full cache line */ 1535 size = max_t(size_t, size, L1_CACHE_BYTES); 1536 1537 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1538 if (!net->ipv4.fib_table_hash) { 1539 err = -ENOMEM; 1540 goto err_table_hash_alloc; 1541 } 1542 1543 err = fib4_rules_init(net); 1544 if (err < 0) 1545 goto err_rules_init; 1546 return 0; 1547 1548 err_rules_init: 1549 kfree(net->ipv4.fib_table_hash); 1550 err_table_hash_alloc: 1551 fib4_notifier_exit(net); 1552 return err; 1553 } 1554 1555 static void ip_fib_net_exit(struct net *net) 1556 { 1557 int i; 1558 1559 ASSERT_RTNL(); 1560 #ifdef CONFIG_IP_MULTIPLE_TABLES 1561 RCU_INIT_POINTER(net->ipv4.fib_main, NULL); 1562 RCU_INIT_POINTER(net->ipv4.fib_default, NULL); 1563 #endif 1564 /* Destroy the tables in reverse order to guarantee that the 1565 * local table, ID 255, is destroyed before the main table, ID 1566 * 254. This is necessary as the local table may contain 1567 * references to data contained in the main table. 1568 */ 1569 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) { 1570 struct hlist_head *head = &net->ipv4.fib_table_hash[i]; 1571 struct hlist_node *tmp; 1572 struct fib_table *tb; 1573 1574 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) { 1575 hlist_del(&tb->tb_hlist); 1576 fib_table_flush(net, tb, true); 1577 fib_free_table(tb); 1578 } 1579 } 1580 1581 #ifdef CONFIG_IP_MULTIPLE_TABLES 1582 fib4_rules_exit(net); 1583 #endif 1584 1585 kfree(net->ipv4.fib_table_hash); 1586 fib4_notifier_exit(net); 1587 } 1588 1589 static int __net_init fib_net_init(struct net *net) 1590 { 1591 int error; 1592 1593 #ifdef CONFIG_IP_ROUTE_CLASSID 1594 atomic_set(&net->ipv4.fib_num_tclassid_users, 0); 1595 #endif 1596 error = ip_fib_net_init(net); 1597 if (error < 0) 1598 goto out; 1599 error = nl_fib_lookup_init(net); 1600 if (error < 0) 1601 goto out_nlfl; 1602 error = fib_proc_init(net); 1603 if (error < 0) 1604 goto out_proc; 1605 out: 1606 return error; 1607 1608 out_proc: 1609 nl_fib_lookup_exit(net); 1610 out_nlfl: 1611 rtnl_lock(); 1612 ip_fib_net_exit(net); 1613 rtnl_unlock(); 1614 goto out; 1615 } 1616 1617 static void __net_exit fib_net_exit(struct net *net) 1618 { 1619 fib_proc_exit(net); 1620 nl_fib_lookup_exit(net); 1621 } 1622 1623 static void __net_exit fib_net_exit_batch(struct list_head *net_list) 1624 { 1625 struct net *net; 1626 1627 rtnl_lock(); 1628 list_for_each_entry(net, net_list, exit_list) 1629 ip_fib_net_exit(net); 1630 1631 rtnl_unlock(); 1632 } 1633 1634 static struct pernet_operations fib_net_ops = { 1635 .init = fib_net_init, 1636 .exit = fib_net_exit, 1637 .exit_batch = fib_net_exit_batch, 1638 }; 1639 1640 void __init ip_fib_init(void) 1641 { 1642 fib_trie_init(); 1643 1644 register_pernet_subsys(&fib_net_ops); 1645 1646 register_netdevice_notifier(&fib_netdev_notifier); 1647 register_inetaddr_notifier(&fib_inetaddr_notifier); 1648 1649 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0); 1650 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0); 1651 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0); 1652 } 1653