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