1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * IPv4 Forwarding Information Base: FIB frontend. 8 * 9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 10 */ 11 12 #include <linux/module.h> 13 #include <linux/uaccess.h> 14 #include <linux/bitops.h> 15 #include <linux/capability.h> 16 #include <linux/types.h> 17 #include <linux/kernel.h> 18 #include <linux/mm.h> 19 #include <linux/string.h> 20 #include <linux/socket.h> 21 #include <linux/sockios.h> 22 #include <linux/errno.h> 23 #include <linux/in.h> 24 #include <linux/inet.h> 25 #include <linux/inetdevice.h> 26 #include <linux/netdevice.h> 27 #include <linux/if_addr.h> 28 #include <linux/if_arp.h> 29 #include <linux/skbuff.h> 30 #include <linux/cache.h> 31 #include <linux/init.h> 32 #include <linux/list.h> 33 #include <linux/slab.h> 34 35 #include <net/ip.h> 36 #include <net/protocol.h> 37 #include <net/route.h> 38 #include <net/tcp.h> 39 #include <net/sock.h> 40 #include <net/arp.h> 41 #include <net/ip_fib.h> 42 #include <net/nexthop.h> 43 #include <net/rtnetlink.h> 44 #include <net/xfrm.h> 45 #include <net/l3mdev.h> 46 #include <net/lwtunnel.h> 47 #include <trace/events/fib.h> 48 49 #ifndef CONFIG_IP_MULTIPLE_TABLES 50 51 static int __net_init fib4_rules_init(struct net *net) 52 { 53 struct fib_table *local_table, *main_table; 54 55 main_table = fib_trie_table(RT_TABLE_MAIN, NULL); 56 if (!main_table) 57 return -ENOMEM; 58 59 local_table = fib_trie_table(RT_TABLE_LOCAL, main_table); 60 if (!local_table) 61 goto fail; 62 63 hlist_add_head_rcu(&local_table->tb_hlist, 64 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]); 65 hlist_add_head_rcu(&main_table->tb_hlist, 66 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]); 67 return 0; 68 69 fail: 70 fib_free_table(main_table); 71 return -ENOMEM; 72 } 73 74 static bool fib4_has_custom_rules(struct net *net) 75 { 76 return false; 77 } 78 #else 79 80 struct fib_table *fib_new_table(struct net *net, u32 id) 81 { 82 struct fib_table *tb, *alias = NULL; 83 unsigned int h; 84 85 if (id == 0) 86 id = RT_TABLE_MAIN; 87 tb = fib_get_table(net, id); 88 if (tb) 89 return tb; 90 91 if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules) 92 alias = fib_new_table(net, RT_TABLE_MAIN); 93 94 tb = fib_trie_table(id, alias); 95 if (!tb) 96 return NULL; 97 98 switch (id) { 99 case RT_TABLE_MAIN: 100 rcu_assign_pointer(net->ipv4.fib_main, tb); 101 break; 102 case RT_TABLE_DEFAULT: 103 rcu_assign_pointer(net->ipv4.fib_default, tb); 104 break; 105 default: 106 break; 107 } 108 109 h = id & (FIB_TABLE_HASHSZ - 1); 110 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]); 111 return tb; 112 } 113 EXPORT_SYMBOL_GPL(fib_new_table); 114 115 /* caller must hold either rtnl or rcu read lock */ 116 struct fib_table *fib_get_table(struct net *net, u32 id) 117 { 118 struct fib_table *tb; 119 struct hlist_head *head; 120 unsigned int h; 121 122 if (id == 0) 123 id = RT_TABLE_MAIN; 124 h = id & (FIB_TABLE_HASHSZ - 1); 125 126 head = &net->ipv4.fib_table_hash[h]; 127 hlist_for_each_entry_rcu(tb, head, tb_hlist, 128 lockdep_rtnl_is_held()) { 129 if (tb->tb_id == id) 130 return tb; 131 } 132 return NULL; 133 } 134 135 static bool fib4_has_custom_rules(struct net *net) 136 { 137 return net->ipv4.fib_has_custom_rules; 138 } 139 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 140 141 static void fib_replace_table(struct net *net, struct fib_table *old, 142 struct fib_table *new) 143 { 144 #ifdef CONFIG_IP_MULTIPLE_TABLES 145 switch (new->tb_id) { 146 case RT_TABLE_MAIN: 147 rcu_assign_pointer(net->ipv4.fib_main, new); 148 break; 149 case RT_TABLE_DEFAULT: 150 rcu_assign_pointer(net->ipv4.fib_default, new); 151 break; 152 default: 153 break; 154 } 155 156 #endif 157 /* replace the old table in the hlist */ 158 hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist); 159 } 160 161 int fib_unmerge(struct net *net) 162 { 163 struct fib_table *old, *new, *main_table; 164 165 /* attempt to fetch local table if it has been allocated */ 166 old = fib_get_table(net, RT_TABLE_LOCAL); 167 if (!old) 168 return 0; 169 170 new = fib_trie_unmerge(old); 171 if (!new) 172 return -ENOMEM; 173 174 /* table is already unmerged */ 175 if (new == old) 176 return 0; 177 178 /* replace merged table with clean table */ 179 fib_replace_table(net, old, new); 180 fib_free_table(old); 181 182 /* attempt to fetch main table if it has been allocated */ 183 main_table = fib_get_table(net, RT_TABLE_MAIN); 184 if (!main_table) 185 return 0; 186 187 /* flush local entries from main table */ 188 fib_table_flush_external(main_table); 189 190 return 0; 191 } 192 193 void fib_flush(struct net *net) 194 { 195 int flushed = 0; 196 unsigned int h; 197 198 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 199 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 200 struct hlist_node *tmp; 201 struct fib_table *tb; 202 203 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) 204 flushed += fib_table_flush(net, tb, false); 205 } 206 207 if (flushed) 208 rt_cache_flush(net); 209 } 210 211 /* 212 * Find address type as if only "dev" was present in the system. If 213 * on_dev is NULL then all interfaces are taken into consideration. 214 */ 215 static inline unsigned int __inet_dev_addr_type(struct net *net, 216 const struct net_device *dev, 217 __be32 addr, u32 tb_id) 218 { 219 struct flowi4 fl4 = { .daddr = addr }; 220 struct fib_result res; 221 unsigned int ret = RTN_BROADCAST; 222 struct fib_table *table; 223 224 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr)) 225 return RTN_BROADCAST; 226 if (ipv4_is_multicast(addr)) 227 return RTN_MULTICAST; 228 229 rcu_read_lock(); 230 231 table = fib_get_table(net, tb_id); 232 if (table) { 233 ret = RTN_UNICAST; 234 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) { 235 struct fib_nh_common *nhc = fib_info_nhc(res.fi, 0); 236 237 if (!dev || dev == nhc->nhc_dev) 238 ret = res.type; 239 } 240 } 241 242 rcu_read_unlock(); 243 return ret; 244 } 245 246 unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id) 247 { 248 return __inet_dev_addr_type(net, NULL, addr, tb_id); 249 } 250 EXPORT_SYMBOL(inet_addr_type_table); 251 252 unsigned int inet_addr_type(struct net *net, __be32 addr) 253 { 254 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL); 255 } 256 EXPORT_SYMBOL(inet_addr_type); 257 258 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, 259 __be32 addr) 260 { 261 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL; 262 263 return __inet_dev_addr_type(net, dev, addr, rt_table); 264 } 265 EXPORT_SYMBOL(inet_dev_addr_type); 266 267 /* inet_addr_type with dev == NULL but using the table from a dev 268 * if one is associated 269 */ 270 unsigned int inet_addr_type_dev_table(struct net *net, 271 const struct net_device *dev, 272 __be32 addr) 273 { 274 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL; 275 276 return __inet_dev_addr_type(net, NULL, addr, rt_table); 277 } 278 EXPORT_SYMBOL(inet_addr_type_dev_table); 279 280 __be32 fib_compute_spec_dst(struct sk_buff *skb) 281 { 282 struct net_device *dev = skb->dev; 283 struct in_device *in_dev; 284 struct fib_result res; 285 struct rtable *rt; 286 struct net *net; 287 int scope; 288 289 rt = skb_rtable(skb); 290 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) == 291 RTCF_LOCAL) 292 return ip_hdr(skb)->daddr; 293 294 in_dev = __in_dev_get_rcu(dev); 295 296 net = dev_net(dev); 297 298 scope = RT_SCOPE_UNIVERSE; 299 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) { 300 bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev); 301 struct flowi4 fl4 = { 302 .flowi4_iif = LOOPBACK_IFINDEX, 303 .flowi4_oif = l3mdev_master_ifindex_rcu(dev), 304 .daddr = ip_hdr(skb)->saddr, 305 .flowi4_tos = RT_TOS(ip_hdr(skb)->tos), 306 .flowi4_scope = scope, 307 .flowi4_mark = vmark ? skb->mark : 0, 308 }; 309 if (!fib_lookup(net, &fl4, &res, 0)) 310 return fib_result_prefsrc(net, &res); 311 } else { 312 scope = RT_SCOPE_LINK; 313 } 314 315 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope); 316 } 317 318 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev) 319 { 320 bool dev_match = false; 321 #ifdef CONFIG_IP_ROUTE_MULTIPATH 322 int ret; 323 324 for (ret = 0; ret < fib_info_num_path(fi); ret++) { 325 const struct fib_nh_common *nhc = fib_info_nhc(fi, ret); 326 327 if (nhc->nhc_dev == dev) { 328 dev_match = true; 329 break; 330 } else if (l3mdev_master_ifindex_rcu(nhc->nhc_dev) == dev->ifindex) { 331 dev_match = true; 332 break; 333 } 334 } 335 #else 336 if (fib_info_nhc(fi, 0)->nhc_dev == dev) 337 dev_match = true; 338 #endif 339 340 return dev_match; 341 } 342 EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev); 343 344 /* Given (packet source, input interface) and optional (dst, oif, tos): 345 * - (main) check, that source is valid i.e. not broadcast or our local 346 * address. 347 * - figure out what "logical" interface this packet arrived 348 * and calculate "specific destination" address. 349 * - check, that packet arrived from expected physical interface. 350 * called with rcu_read_lock() 351 */ 352 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 353 u8 tos, int oif, struct net_device *dev, 354 int rpf, struct in_device *idev, u32 *itag) 355 { 356 struct net *net = dev_net(dev); 357 struct flow_keys flkeys; 358 int ret, no_addr; 359 struct fib_result res; 360 struct flowi4 fl4; 361 bool dev_match; 362 363 fl4.flowi4_oif = 0; 364 fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev); 365 if (!fl4.flowi4_iif) 366 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX; 367 fl4.daddr = src; 368 fl4.saddr = dst; 369 fl4.flowi4_tos = tos; 370 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 371 fl4.flowi4_tun_key.tun_id = 0; 372 fl4.flowi4_flags = 0; 373 fl4.flowi4_uid = sock_net_uid(net, NULL); 374 375 no_addr = idev->ifa_list == NULL; 376 377 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0; 378 if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) { 379 fl4.flowi4_proto = 0; 380 fl4.fl4_sport = 0; 381 fl4.fl4_dport = 0; 382 } 383 384 if (fib_lookup(net, &fl4, &res, 0)) 385 goto last_resort; 386 if (res.type != RTN_UNICAST && 387 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev))) 388 goto e_inval; 389 fib_combine_itag(itag, &res); 390 391 dev_match = fib_info_nh_uses_dev(res.fi, dev); 392 /* This is not common, loopback packets retain skb_dst so normally they 393 * would not even hit this slow path. 394 */ 395 dev_match = dev_match || (res.type == RTN_LOCAL && 396 dev == net->loopback_dev); 397 if (dev_match) { 398 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; 399 return ret; 400 } 401 if (no_addr) 402 goto last_resort; 403 if (rpf == 1) 404 goto e_rpf; 405 fl4.flowi4_oif = dev->ifindex; 406 407 ret = 0; 408 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) { 409 if (res.type == RTN_UNICAST) 410 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; 411 } 412 return ret; 413 414 last_resort: 415 if (rpf) 416 goto e_rpf; 417 *itag = 0; 418 return 0; 419 420 e_inval: 421 return -EINVAL; 422 e_rpf: 423 return -EXDEV; 424 } 425 426 /* Ignore rp_filter for packets protected by IPsec. */ 427 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 428 u8 tos, int oif, struct net_device *dev, 429 struct in_device *idev, u32 *itag) 430 { 431 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev); 432 struct net *net = dev_net(dev); 433 434 if (!r && !fib_num_tclassid_users(net) && 435 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) { 436 if (IN_DEV_ACCEPT_LOCAL(idev)) 437 goto ok; 438 /* with custom local routes in place, checking local addresses 439 * only will be too optimistic, with custom rules, checking 440 * local addresses only can be too strict, e.g. due to vrf 441 */ 442 if (net->ipv4.fib_has_custom_local_routes || 443 fib4_has_custom_rules(net)) 444 goto full_check; 445 if (inet_lookup_ifaddr_rcu(net, src)) 446 return -EINVAL; 447 448 ok: 449 *itag = 0; 450 return 0; 451 } 452 453 full_check: 454 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag); 455 } 456 457 static inline __be32 sk_extract_addr(struct sockaddr *addr) 458 { 459 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 460 } 461 462 static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 463 { 464 struct nlattr *nla; 465 466 nla = (struct nlattr *) ((char *) mx + len); 467 nla->nla_type = type; 468 nla->nla_len = nla_attr_size(4); 469 *(u32 *) nla_data(nla) = value; 470 471 return len + nla_total_size(4); 472 } 473 474 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 475 struct fib_config *cfg) 476 { 477 __be32 addr; 478 int plen; 479 480 memset(cfg, 0, sizeof(*cfg)); 481 cfg->fc_nlinfo.nl_net = net; 482 483 if (rt->rt_dst.sa_family != AF_INET) 484 return -EAFNOSUPPORT; 485 486 /* 487 * Check mask for validity: 488 * a) it must be contiguous. 489 * b) destination must have all host bits clear. 490 * c) if application forgot to set correct family (AF_INET), 491 * reject request unless it is absolutely clear i.e. 492 * both family and mask are zero. 493 */ 494 plen = 32; 495 addr = sk_extract_addr(&rt->rt_dst); 496 if (!(rt->rt_flags & RTF_HOST)) { 497 __be32 mask = sk_extract_addr(&rt->rt_genmask); 498 499 if (rt->rt_genmask.sa_family != AF_INET) { 500 if (mask || rt->rt_genmask.sa_family) 501 return -EAFNOSUPPORT; 502 } 503 504 if (bad_mask(mask, addr)) 505 return -EINVAL; 506 507 plen = inet_mask_len(mask); 508 } 509 510 cfg->fc_dst_len = plen; 511 cfg->fc_dst = addr; 512 513 if (cmd != SIOCDELRT) { 514 cfg->fc_nlflags = NLM_F_CREATE; 515 cfg->fc_protocol = RTPROT_BOOT; 516 } 517 518 if (rt->rt_metric) 519 cfg->fc_priority = rt->rt_metric - 1; 520 521 if (rt->rt_flags & RTF_REJECT) { 522 cfg->fc_scope = RT_SCOPE_HOST; 523 cfg->fc_type = RTN_UNREACHABLE; 524 return 0; 525 } 526 527 cfg->fc_scope = RT_SCOPE_NOWHERE; 528 cfg->fc_type = RTN_UNICAST; 529 530 if (rt->rt_dev) { 531 char *colon; 532 struct net_device *dev; 533 char devname[IFNAMSIZ]; 534 535 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 536 return -EFAULT; 537 538 devname[IFNAMSIZ-1] = 0; 539 colon = strchr(devname, ':'); 540 if (colon) 541 *colon = 0; 542 dev = __dev_get_by_name(net, devname); 543 if (!dev) 544 return -ENODEV; 545 cfg->fc_oif = dev->ifindex; 546 cfg->fc_table = l3mdev_fib_table(dev); 547 if (colon) { 548 const struct in_ifaddr *ifa; 549 struct in_device *in_dev; 550 551 in_dev = __in_dev_get_rtnl(dev); 552 if (!in_dev) 553 return -ENODEV; 554 555 *colon = ':'; 556 557 rcu_read_lock(); 558 in_dev_for_each_ifa_rcu(ifa, in_dev) { 559 if (strcmp(ifa->ifa_label, devname) == 0) 560 break; 561 } 562 rcu_read_unlock(); 563 564 if (!ifa) 565 return -ENODEV; 566 cfg->fc_prefsrc = ifa->ifa_local; 567 } 568 } 569 570 addr = sk_extract_addr(&rt->rt_gateway); 571 if (rt->rt_gateway.sa_family == AF_INET && addr) { 572 unsigned int addr_type; 573 574 cfg->fc_gw4 = addr; 575 cfg->fc_gw_family = AF_INET; 576 addr_type = inet_addr_type_table(net, addr, cfg->fc_table); 577 if (rt->rt_flags & RTF_GATEWAY && 578 addr_type == RTN_UNICAST) 579 cfg->fc_scope = RT_SCOPE_UNIVERSE; 580 } 581 582 if (cmd == SIOCDELRT) 583 return 0; 584 585 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family) 586 return -EINVAL; 587 588 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 589 cfg->fc_scope = RT_SCOPE_LINK; 590 591 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 592 struct nlattr *mx; 593 int len = 0; 594 595 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL); 596 if (!mx) 597 return -ENOMEM; 598 599 if (rt->rt_flags & RTF_MTU) 600 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 601 602 if (rt->rt_flags & RTF_WINDOW) 603 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 604 605 if (rt->rt_flags & RTF_IRTT) 606 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 607 608 cfg->fc_mx = mx; 609 cfg->fc_mx_len = len; 610 } 611 612 return 0; 613 } 614 615 /* 616 * Handle IP routing ioctl calls. 617 * These are used to manipulate the routing tables 618 */ 619 int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt) 620 { 621 struct fib_config cfg; 622 int err; 623 624 switch (cmd) { 625 case SIOCADDRT: /* Add a route */ 626 case SIOCDELRT: /* Delete a route */ 627 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 628 return -EPERM; 629 630 rtnl_lock(); 631 err = rtentry_to_fib_config(net, cmd, rt, &cfg); 632 if (err == 0) { 633 struct fib_table *tb; 634 635 if (cmd == SIOCDELRT) { 636 tb = fib_get_table(net, cfg.fc_table); 637 if (tb) 638 err = fib_table_delete(net, tb, &cfg, 639 NULL); 640 else 641 err = -ESRCH; 642 } else { 643 tb = fib_new_table(net, cfg.fc_table); 644 if (tb) 645 err = fib_table_insert(net, tb, 646 &cfg, NULL); 647 else 648 err = -ENOBUFS; 649 } 650 651 /* allocated by rtentry_to_fib_config() */ 652 kfree(cfg.fc_mx); 653 } 654 rtnl_unlock(); 655 return err; 656 } 657 return -EINVAL; 658 } 659 660 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 661 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 }, 662 [RTA_DST] = { .type = NLA_U32 }, 663 [RTA_SRC] = { .type = NLA_U32 }, 664 [RTA_IIF] = { .type = NLA_U32 }, 665 [RTA_OIF] = { .type = NLA_U32 }, 666 [RTA_GATEWAY] = { .type = NLA_U32 }, 667 [RTA_PRIORITY] = { .type = NLA_U32 }, 668 [RTA_PREFSRC] = { .type = NLA_U32 }, 669 [RTA_METRICS] = { .type = NLA_NESTED }, 670 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 671 [RTA_FLOW] = { .type = NLA_U32 }, 672 [RTA_ENCAP_TYPE] = { .type = NLA_U16 }, 673 [RTA_ENCAP] = { .type = NLA_NESTED }, 674 [RTA_UID] = { .type = NLA_U32 }, 675 [RTA_MARK] = { .type = NLA_U32 }, 676 [RTA_TABLE] = { .type = NLA_U32 }, 677 [RTA_IP_PROTO] = { .type = NLA_U8 }, 678 [RTA_SPORT] = { .type = NLA_U16 }, 679 [RTA_DPORT] = { .type = NLA_U16 }, 680 [RTA_NH_ID] = { .type = NLA_U32 }, 681 }; 682 683 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, 684 struct netlink_ext_ack *extack) 685 { 686 struct rtvia *via; 687 int alen; 688 689 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) { 690 NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA"); 691 return -EINVAL; 692 } 693 694 via = nla_data(nla); 695 alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr); 696 697 switch (via->rtvia_family) { 698 case AF_INET: 699 if (alen != sizeof(__be32)) { 700 NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA"); 701 return -EINVAL; 702 } 703 cfg->fc_gw_family = AF_INET; 704 cfg->fc_gw4 = *((__be32 *)via->rtvia_addr); 705 break; 706 case AF_INET6: 707 #ifdef CONFIG_IPV6 708 if (alen != sizeof(struct in6_addr)) { 709 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA"); 710 return -EINVAL; 711 } 712 cfg->fc_gw_family = AF_INET6; 713 cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr); 714 #else 715 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel"); 716 return -EINVAL; 717 #endif 718 break; 719 default: 720 NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA"); 721 return -EINVAL; 722 } 723 724 return 0; 725 } 726 727 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 728 struct nlmsghdr *nlh, struct fib_config *cfg, 729 struct netlink_ext_ack *extack) 730 { 731 bool has_gw = false, has_via = false; 732 struct nlattr *attr; 733 int err, remaining; 734 struct rtmsg *rtm; 735 736 err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX, 737 rtm_ipv4_policy, extack); 738 if (err < 0) 739 goto errout; 740 741 memset(cfg, 0, sizeof(*cfg)); 742 743 rtm = nlmsg_data(nlh); 744 cfg->fc_dst_len = rtm->rtm_dst_len; 745 cfg->fc_tos = rtm->rtm_tos; 746 cfg->fc_table = rtm->rtm_table; 747 cfg->fc_protocol = rtm->rtm_protocol; 748 cfg->fc_scope = rtm->rtm_scope; 749 cfg->fc_type = rtm->rtm_type; 750 cfg->fc_flags = rtm->rtm_flags; 751 cfg->fc_nlflags = nlh->nlmsg_flags; 752 753 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid; 754 cfg->fc_nlinfo.nlh = nlh; 755 cfg->fc_nlinfo.nl_net = net; 756 757 if (cfg->fc_type > RTN_MAX) { 758 NL_SET_ERR_MSG(extack, "Invalid route type"); 759 err = -EINVAL; 760 goto errout; 761 } 762 763 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 764 switch (nla_type(attr)) { 765 case RTA_DST: 766 cfg->fc_dst = nla_get_be32(attr); 767 break; 768 case RTA_OIF: 769 cfg->fc_oif = nla_get_u32(attr); 770 break; 771 case RTA_GATEWAY: 772 has_gw = true; 773 cfg->fc_gw4 = nla_get_be32(attr); 774 if (cfg->fc_gw4) 775 cfg->fc_gw_family = AF_INET; 776 break; 777 case RTA_VIA: 778 has_via = true; 779 err = fib_gw_from_via(cfg, attr, extack); 780 if (err) 781 goto errout; 782 break; 783 case RTA_PRIORITY: 784 cfg->fc_priority = nla_get_u32(attr); 785 break; 786 case RTA_PREFSRC: 787 cfg->fc_prefsrc = nla_get_be32(attr); 788 break; 789 case RTA_METRICS: 790 cfg->fc_mx = nla_data(attr); 791 cfg->fc_mx_len = nla_len(attr); 792 break; 793 case RTA_MULTIPATH: 794 err = lwtunnel_valid_encap_type_attr(nla_data(attr), 795 nla_len(attr), 796 extack); 797 if (err < 0) 798 goto errout; 799 cfg->fc_mp = nla_data(attr); 800 cfg->fc_mp_len = nla_len(attr); 801 break; 802 case RTA_FLOW: 803 cfg->fc_flow = nla_get_u32(attr); 804 break; 805 case RTA_TABLE: 806 cfg->fc_table = nla_get_u32(attr); 807 break; 808 case RTA_ENCAP: 809 cfg->fc_encap = attr; 810 break; 811 case RTA_ENCAP_TYPE: 812 cfg->fc_encap_type = nla_get_u16(attr); 813 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, 814 extack); 815 if (err < 0) 816 goto errout; 817 break; 818 case RTA_NH_ID: 819 cfg->fc_nh_id = nla_get_u32(attr); 820 break; 821 } 822 } 823 824 if (cfg->fc_nh_id) { 825 if (cfg->fc_oif || cfg->fc_gw_family || 826 cfg->fc_encap || cfg->fc_mp) { 827 NL_SET_ERR_MSG(extack, 828 "Nexthop specification and nexthop id are mutually exclusive"); 829 return -EINVAL; 830 } 831 } 832 833 if (has_gw && has_via) { 834 NL_SET_ERR_MSG(extack, 835 "Nexthop configuration can not contain both GATEWAY and VIA"); 836 goto errout; 837 } 838 839 return 0; 840 errout: 841 return err; 842 } 843 844 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, 845 struct netlink_ext_ack *extack) 846 { 847 struct net *net = sock_net(skb->sk); 848 struct fib_config cfg; 849 struct fib_table *tb; 850 int err; 851 852 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 853 if (err < 0) 854 goto errout; 855 856 if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) { 857 NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); 858 err = -EINVAL; 859 goto errout; 860 } 861 862 tb = fib_get_table(net, cfg.fc_table); 863 if (!tb) { 864 NL_SET_ERR_MSG(extack, "FIB table does not exist"); 865 err = -ESRCH; 866 goto errout; 867 } 868 869 err = fib_table_delete(net, tb, &cfg, extack); 870 errout: 871 return err; 872 } 873 874 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, 875 struct netlink_ext_ack *extack) 876 { 877 struct net *net = sock_net(skb->sk); 878 struct fib_config cfg; 879 struct fib_table *tb; 880 int err; 881 882 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); 883 if (err < 0) 884 goto errout; 885 886 tb = fib_new_table(net, cfg.fc_table); 887 if (!tb) { 888 err = -ENOBUFS; 889 goto errout; 890 } 891 892 err = fib_table_insert(net, tb, &cfg, extack); 893 if (!err && cfg.fc_type == RTN_LOCAL) 894 net->ipv4.fib_has_custom_local_routes = true; 895 errout: 896 return err; 897 } 898 899 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 900 struct fib_dump_filter *filter, 901 struct netlink_callback *cb) 902 { 903 struct netlink_ext_ack *extack = cb->extack; 904 struct nlattr *tb[RTA_MAX + 1]; 905 struct rtmsg *rtm; 906 int err, i; 907 908 ASSERT_RTNL(); 909 910 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 911 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request"); 912 return -EINVAL; 913 } 914 915 rtm = nlmsg_data(nlh); 916 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos || 917 rtm->rtm_scope) { 918 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request"); 919 return -EINVAL; 920 } 921 922 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) { 923 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request"); 924 return -EINVAL; 925 } 926 if (rtm->rtm_flags & RTM_F_CLONED) 927 filter->dump_routes = false; 928 else 929 filter->dump_exceptions = false; 930 931 filter->dump_all_families = (rtm->rtm_family == AF_UNSPEC); 932 filter->flags = rtm->rtm_flags; 933 filter->protocol = rtm->rtm_protocol; 934 filter->rt_type = rtm->rtm_type; 935 filter->table_id = rtm->rtm_table; 936 937 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 938 rtm_ipv4_policy, extack); 939 if (err < 0) 940 return err; 941 942 for (i = 0; i <= RTA_MAX; ++i) { 943 int ifindex; 944 945 if (!tb[i]) 946 continue; 947 948 switch (i) { 949 case RTA_TABLE: 950 filter->table_id = nla_get_u32(tb[i]); 951 break; 952 case RTA_OIF: 953 ifindex = nla_get_u32(tb[i]); 954 filter->dev = __dev_get_by_index(net, ifindex); 955 if (!filter->dev) 956 return -ENODEV; 957 break; 958 default: 959 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request"); 960 return -EINVAL; 961 } 962 } 963 964 if (filter->flags || filter->protocol || filter->rt_type || 965 filter->table_id || filter->dev) { 966 filter->filter_set = 1; 967 cb->answer_flags = NLM_F_DUMP_FILTERED; 968 } 969 970 return 0; 971 } 972 EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req); 973 974 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 975 { 976 struct fib_dump_filter filter = { .dump_routes = true, 977 .dump_exceptions = true }; 978 const struct nlmsghdr *nlh = cb->nlh; 979 struct net *net = sock_net(skb->sk); 980 unsigned int h, s_h; 981 unsigned int e = 0, s_e; 982 struct fib_table *tb; 983 struct hlist_head *head; 984 int dumped = 0, err; 985 986 if (cb->strict_check) { 987 err = ip_valid_fib_dump_req(net, nlh, &filter, cb); 988 if (err < 0) 989 return err; 990 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 991 struct rtmsg *rtm = nlmsg_data(nlh); 992 993 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED); 994 } 995 996 /* ipv4 does not use prefix flag */ 997 if (filter.flags & RTM_F_PREFIX) 998 return skb->len; 999 1000 if (filter.table_id) { 1001 tb = fib_get_table(net, filter.table_id); 1002 if (!tb) { 1003 if (filter.dump_all_families) 1004 return skb->len; 1005 1006 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist"); 1007 return -ENOENT; 1008 } 1009 1010 err = fib_table_dump(tb, skb, cb, &filter); 1011 return skb->len ? : err; 1012 } 1013 1014 s_h = cb->args[0]; 1015 s_e = cb->args[1]; 1016 1017 rcu_read_lock(); 1018 1019 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 1020 e = 0; 1021 head = &net->ipv4.fib_table_hash[h]; 1022 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 1023 if (e < s_e) 1024 goto next; 1025 if (dumped) 1026 memset(&cb->args[2], 0, sizeof(cb->args) - 1027 2 * sizeof(cb->args[0])); 1028 err = fib_table_dump(tb, skb, cb, &filter); 1029 if (err < 0) { 1030 if (likely(skb->len)) 1031 goto out; 1032 1033 goto out_err; 1034 } 1035 dumped = 1; 1036 next: 1037 e++; 1038 } 1039 } 1040 out: 1041 err = skb->len; 1042 out_err: 1043 rcu_read_unlock(); 1044 1045 cb->args[1] = e; 1046 cb->args[0] = h; 1047 1048 return err; 1049 } 1050 1051 /* Prepare and feed intra-kernel routing request. 1052 * Really, it should be netlink message, but :-( netlink 1053 * can be not configured, so that we feed it directly 1054 * to fib engine. It is legal, because all events occur 1055 * only when netlink is already locked. 1056 */ 1057 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, 1058 struct in_ifaddr *ifa, u32 rt_priority) 1059 { 1060 struct net *net = dev_net(ifa->ifa_dev->dev); 1061 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev); 1062 struct fib_table *tb; 1063 struct fib_config cfg = { 1064 .fc_protocol = RTPROT_KERNEL, 1065 .fc_type = type, 1066 .fc_dst = dst, 1067 .fc_dst_len = dst_len, 1068 .fc_priority = rt_priority, 1069 .fc_prefsrc = ifa->ifa_local, 1070 .fc_oif = ifa->ifa_dev->dev->ifindex, 1071 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 1072 .fc_nlinfo = { 1073 .nl_net = net, 1074 }, 1075 }; 1076 1077 if (!tb_id) 1078 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL; 1079 1080 tb = fib_new_table(net, tb_id); 1081 if (!tb) 1082 return; 1083 1084 cfg.fc_table = tb->tb_id; 1085 1086 if (type != RTN_LOCAL) 1087 cfg.fc_scope = RT_SCOPE_LINK; 1088 else 1089 cfg.fc_scope = RT_SCOPE_HOST; 1090 1091 if (cmd == RTM_NEWROUTE) 1092 fib_table_insert(net, tb, &cfg, NULL); 1093 else 1094 fib_table_delete(net, tb, &cfg, NULL); 1095 } 1096 1097 void fib_add_ifaddr(struct in_ifaddr *ifa) 1098 { 1099 struct in_device *in_dev = ifa->ifa_dev; 1100 struct net_device *dev = in_dev->dev; 1101 struct in_ifaddr *prim = ifa; 1102 __be32 mask = ifa->ifa_mask; 1103 __be32 addr = ifa->ifa_local; 1104 __be32 prefix = ifa->ifa_address & mask; 1105 1106 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1107 prim = inet_ifa_byprefix(in_dev, prefix, mask); 1108 if (!prim) { 1109 pr_warn("%s: bug: prim == NULL\n", __func__); 1110 return; 1111 } 1112 } 1113 1114 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0); 1115 1116 if (!(dev->flags & IFF_UP)) 1117 return; 1118 1119 /* Add broadcast address, if it is explicitly assigned. */ 1120 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 1121 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1122 prim, 0); 1123 1124 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 1125 (prefix != addr || ifa->ifa_prefixlen < 32)) { 1126 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1127 fib_magic(RTM_NEWROUTE, 1128 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1129 prefix, ifa->ifa_prefixlen, prim, 1130 ifa->ifa_rt_priority); 1131 1132 /* Add network specific broadcasts, when it takes a sense */ 1133 if (ifa->ifa_prefixlen < 31) { 1134 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, 1135 prim, 0); 1136 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 1137 32, prim, 0); 1138 } 1139 } 1140 } 1141 1142 void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric) 1143 { 1144 __be32 prefix = ifa->ifa_address & ifa->ifa_mask; 1145 struct in_device *in_dev = ifa->ifa_dev; 1146 struct net_device *dev = in_dev->dev; 1147 1148 if (!(dev->flags & IFF_UP) || 1149 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) || 1150 ipv4_is_zeronet(prefix) || 1151 (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32)) 1152 return; 1153 1154 /* add the new */ 1155 fib_magic(RTM_NEWROUTE, 1156 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1157 prefix, ifa->ifa_prefixlen, ifa, new_metric); 1158 1159 /* delete the old */ 1160 fib_magic(RTM_DELROUTE, 1161 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1162 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority); 1163 } 1164 1165 /* Delete primary or secondary address. 1166 * Optionally, on secondary address promotion consider the addresses 1167 * from subnet iprim as deleted, even if they are in device list. 1168 * In this case the secondary ifa can be in device list. 1169 */ 1170 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 1171 { 1172 struct in_device *in_dev = ifa->ifa_dev; 1173 struct net_device *dev = in_dev->dev; 1174 struct in_ifaddr *ifa1; 1175 struct in_ifaddr *prim = ifa, *prim1 = NULL; 1176 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 1177 __be32 any = ifa->ifa_address & ifa->ifa_mask; 1178 #define LOCAL_OK 1 1179 #define BRD_OK 2 1180 #define BRD0_OK 4 1181 #define BRD1_OK 8 1182 unsigned int ok = 0; 1183 int subnet = 0; /* Primary network */ 1184 int gone = 1; /* Address is missing */ 1185 int same_prefsrc = 0; /* Another primary with same IP */ 1186 1187 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1188 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 1189 if (!prim) { 1190 /* if the device has been deleted, we don't perform 1191 * address promotion 1192 */ 1193 if (!in_dev->dead) 1194 pr_warn("%s: bug: prim == NULL\n", __func__); 1195 return; 1196 } 1197 if (iprim && iprim != prim) { 1198 pr_warn("%s: bug: iprim != prim\n", __func__); 1199 return; 1200 } 1201 } else if (!ipv4_is_zeronet(any) && 1202 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 1203 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1204 fib_magic(RTM_DELROUTE, 1205 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1206 any, ifa->ifa_prefixlen, prim, 0); 1207 subnet = 1; 1208 } 1209 1210 if (in_dev->dead) 1211 goto no_promotions; 1212 1213 /* Deletion is more complicated than add. 1214 * We should take care of not to delete too much :-) 1215 * 1216 * Scan address list to be sure that addresses are really gone. 1217 */ 1218 rcu_read_lock(); 1219 in_dev_for_each_ifa_rcu(ifa1, in_dev) { 1220 if (ifa1 == ifa) { 1221 /* promotion, keep the IP */ 1222 gone = 0; 1223 continue; 1224 } 1225 /* Ignore IFAs from our subnet */ 1226 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 1227 inet_ifa_match(ifa1->ifa_address, iprim)) 1228 continue; 1229 1230 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 1231 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 1232 /* Another address from our subnet? */ 1233 if (ifa1->ifa_mask == prim->ifa_mask && 1234 inet_ifa_match(ifa1->ifa_address, prim)) 1235 prim1 = prim; 1236 else { 1237 /* We reached the secondaries, so 1238 * same_prefsrc should be determined. 1239 */ 1240 if (!same_prefsrc) 1241 continue; 1242 /* Search new prim1 if ifa1 is not 1243 * using the current prim1 1244 */ 1245 if (!prim1 || 1246 ifa1->ifa_mask != prim1->ifa_mask || 1247 !inet_ifa_match(ifa1->ifa_address, prim1)) 1248 prim1 = inet_ifa_byprefix(in_dev, 1249 ifa1->ifa_address, 1250 ifa1->ifa_mask); 1251 if (!prim1) 1252 continue; 1253 if (prim1->ifa_local != prim->ifa_local) 1254 continue; 1255 } 1256 } else { 1257 if (prim->ifa_local != ifa1->ifa_local) 1258 continue; 1259 prim1 = ifa1; 1260 if (prim != prim1) 1261 same_prefsrc = 1; 1262 } 1263 if (ifa->ifa_local == ifa1->ifa_local) 1264 ok |= LOCAL_OK; 1265 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 1266 ok |= BRD_OK; 1267 if (brd == ifa1->ifa_broadcast) 1268 ok |= BRD1_OK; 1269 if (any == ifa1->ifa_broadcast) 1270 ok |= BRD0_OK; 1271 /* primary has network specific broadcasts */ 1272 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 1273 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 1274 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 1275 1276 if (!ipv4_is_zeronet(any1)) { 1277 if (ifa->ifa_broadcast == brd1 || 1278 ifa->ifa_broadcast == any1) 1279 ok |= BRD_OK; 1280 if (brd == brd1 || brd == any1) 1281 ok |= BRD1_OK; 1282 if (any == brd1 || any == any1) 1283 ok |= BRD0_OK; 1284 } 1285 } 1286 } 1287 rcu_read_unlock(); 1288 1289 no_promotions: 1290 if (!(ok & BRD_OK)) 1291 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1292 prim, 0); 1293 if (subnet && ifa->ifa_prefixlen < 31) { 1294 if (!(ok & BRD1_OK)) 1295 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, 1296 prim, 0); 1297 if (!(ok & BRD0_OK)) 1298 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, 1299 prim, 0); 1300 } 1301 if (!(ok & LOCAL_OK)) { 1302 unsigned int addr_type; 1303 1304 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0); 1305 1306 /* Check, that this local address finally disappeared. */ 1307 addr_type = inet_addr_type_dev_table(dev_net(dev), dev, 1308 ifa->ifa_local); 1309 if (gone && addr_type != RTN_LOCAL) { 1310 /* And the last, but not the least thing. 1311 * We must flush stray FIB entries. 1312 * 1313 * First of all, we scan fib_info list searching 1314 * for stray nexthop entries, then ignite fib_flush. 1315 */ 1316 if (fib_sync_down_addr(dev, ifa->ifa_local)) 1317 fib_flush(dev_net(dev)); 1318 } 1319 } 1320 #undef LOCAL_OK 1321 #undef BRD_OK 1322 #undef BRD0_OK 1323 #undef BRD1_OK 1324 } 1325 1326 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn) 1327 { 1328 1329 struct fib_result res; 1330 struct flowi4 fl4 = { 1331 .flowi4_mark = frn->fl_mark, 1332 .daddr = frn->fl_addr, 1333 .flowi4_tos = frn->fl_tos, 1334 .flowi4_scope = frn->fl_scope, 1335 }; 1336 struct fib_table *tb; 1337 1338 rcu_read_lock(); 1339 1340 tb = fib_get_table(net, frn->tb_id_in); 1341 1342 frn->err = -ENOENT; 1343 if (tb) { 1344 local_bh_disable(); 1345 1346 frn->tb_id = tb->tb_id; 1347 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 1348 1349 if (!frn->err) { 1350 frn->prefixlen = res.prefixlen; 1351 frn->nh_sel = res.nh_sel; 1352 frn->type = res.type; 1353 frn->scope = res.scope; 1354 } 1355 local_bh_enable(); 1356 } 1357 1358 rcu_read_unlock(); 1359 } 1360 1361 static void nl_fib_input(struct sk_buff *skb) 1362 { 1363 struct net *net; 1364 struct fib_result_nl *frn; 1365 struct nlmsghdr *nlh; 1366 u32 portid; 1367 1368 net = sock_net(skb->sk); 1369 nlh = nlmsg_hdr(skb); 1370 if (skb->len < nlmsg_total_size(sizeof(*frn)) || 1371 skb->len < nlh->nlmsg_len || 1372 nlmsg_len(nlh) < sizeof(*frn)) 1373 return; 1374 1375 skb = netlink_skb_clone(skb, GFP_KERNEL); 1376 if (!skb) 1377 return; 1378 nlh = nlmsg_hdr(skb); 1379 1380 frn = (struct fib_result_nl *) nlmsg_data(nlh); 1381 nl_fib_lookup(net, frn); 1382 1383 portid = NETLINK_CB(skb).portid; /* netlink portid */ 1384 NETLINK_CB(skb).portid = 0; /* from kernel */ 1385 NETLINK_CB(skb).dst_group = 0; /* unicast */ 1386 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT); 1387 } 1388 1389 static int __net_init nl_fib_lookup_init(struct net *net) 1390 { 1391 struct sock *sk; 1392 struct netlink_kernel_cfg cfg = { 1393 .input = nl_fib_input, 1394 }; 1395 1396 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg); 1397 if (!sk) 1398 return -EAFNOSUPPORT; 1399 net->ipv4.fibnl = sk; 1400 return 0; 1401 } 1402 1403 static void nl_fib_lookup_exit(struct net *net) 1404 { 1405 netlink_kernel_release(net->ipv4.fibnl); 1406 net->ipv4.fibnl = NULL; 1407 } 1408 1409 static void fib_disable_ip(struct net_device *dev, unsigned long event, 1410 bool force) 1411 { 1412 if (fib_sync_down_dev(dev, event, force)) 1413 fib_flush(dev_net(dev)); 1414 else 1415 rt_cache_flush(dev_net(dev)); 1416 arp_ifdown(dev); 1417 } 1418 1419 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 1420 { 1421 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 1422 struct net_device *dev = ifa->ifa_dev->dev; 1423 struct net *net = dev_net(dev); 1424 1425 switch (event) { 1426 case NETDEV_UP: 1427 fib_add_ifaddr(ifa); 1428 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1429 fib_sync_up(dev, RTNH_F_DEAD); 1430 #endif 1431 atomic_inc(&net->ipv4.dev_addr_genid); 1432 rt_cache_flush(dev_net(dev)); 1433 break; 1434 case NETDEV_DOWN: 1435 fib_del_ifaddr(ifa, NULL); 1436 atomic_inc(&net->ipv4.dev_addr_genid); 1437 if (!ifa->ifa_dev->ifa_list) { 1438 /* Last address was deleted from this interface. 1439 * Disable IP. 1440 */ 1441 fib_disable_ip(dev, event, true); 1442 } else { 1443 rt_cache_flush(dev_net(dev)); 1444 } 1445 break; 1446 } 1447 return NOTIFY_DONE; 1448 } 1449 1450 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1451 { 1452 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1453 struct netdev_notifier_changeupper_info *upper_info = ptr; 1454 struct netdev_notifier_info_ext *info_ext = ptr; 1455 struct in_device *in_dev; 1456 struct net *net = dev_net(dev); 1457 struct in_ifaddr *ifa; 1458 unsigned int flags; 1459 1460 if (event == NETDEV_UNREGISTER) { 1461 fib_disable_ip(dev, event, true); 1462 rt_flush_dev(dev); 1463 return NOTIFY_DONE; 1464 } 1465 1466 in_dev = __in_dev_get_rtnl(dev); 1467 if (!in_dev) 1468 return NOTIFY_DONE; 1469 1470 switch (event) { 1471 case NETDEV_UP: 1472 in_dev_for_each_ifa_rtnl(ifa, in_dev) { 1473 fib_add_ifaddr(ifa); 1474 } 1475 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1476 fib_sync_up(dev, RTNH_F_DEAD); 1477 #endif 1478 atomic_inc(&net->ipv4.dev_addr_genid); 1479 rt_cache_flush(net); 1480 break; 1481 case NETDEV_DOWN: 1482 fib_disable_ip(dev, event, false); 1483 break; 1484 case NETDEV_CHANGE: 1485 flags = dev_get_flags(dev); 1486 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1487 fib_sync_up(dev, RTNH_F_LINKDOWN); 1488 else 1489 fib_sync_down_dev(dev, event, false); 1490 rt_cache_flush(net); 1491 break; 1492 case NETDEV_CHANGEMTU: 1493 fib_sync_mtu(dev, info_ext->ext.mtu); 1494 rt_cache_flush(net); 1495 break; 1496 case NETDEV_CHANGEUPPER: 1497 upper_info = ptr; 1498 /* flush all routes if dev is linked to or unlinked from 1499 * an L3 master device (e.g., VRF) 1500 */ 1501 if (upper_info->upper_dev && 1502 netif_is_l3_master(upper_info->upper_dev)) 1503 fib_disable_ip(dev, NETDEV_DOWN, true); 1504 break; 1505 } 1506 return NOTIFY_DONE; 1507 } 1508 1509 static struct notifier_block fib_inetaddr_notifier = { 1510 .notifier_call = fib_inetaddr_event, 1511 }; 1512 1513 static struct notifier_block fib_netdev_notifier = { 1514 .notifier_call = fib_netdev_event, 1515 }; 1516 1517 static int __net_init ip_fib_net_init(struct net *net) 1518 { 1519 int err; 1520 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1521 1522 err = fib4_notifier_init(net); 1523 if (err) 1524 return err; 1525 1526 /* Avoid false sharing : Use at least a full cache line */ 1527 size = max_t(size_t, size, L1_CACHE_BYTES); 1528 1529 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1530 if (!net->ipv4.fib_table_hash) { 1531 err = -ENOMEM; 1532 goto err_table_hash_alloc; 1533 } 1534 1535 err = fib4_rules_init(net); 1536 if (err < 0) 1537 goto err_rules_init; 1538 return 0; 1539 1540 err_rules_init: 1541 kfree(net->ipv4.fib_table_hash); 1542 err_table_hash_alloc: 1543 fib4_notifier_exit(net); 1544 return err; 1545 } 1546 1547 static void ip_fib_net_exit(struct net *net) 1548 { 1549 int i; 1550 1551 rtnl_lock(); 1552 #ifdef CONFIG_IP_MULTIPLE_TABLES 1553 RCU_INIT_POINTER(net->ipv4.fib_main, NULL); 1554 RCU_INIT_POINTER(net->ipv4.fib_default, NULL); 1555 #endif 1556 /* Destroy the tables in reverse order to guarantee that the 1557 * local table, ID 255, is destroyed before the main table, ID 1558 * 254. This is necessary as the local table may contain 1559 * references to data contained in the main table. 1560 */ 1561 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) { 1562 struct hlist_head *head = &net->ipv4.fib_table_hash[i]; 1563 struct hlist_node *tmp; 1564 struct fib_table *tb; 1565 1566 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) { 1567 hlist_del(&tb->tb_hlist); 1568 fib_table_flush(net, tb, true); 1569 fib_free_table(tb); 1570 } 1571 } 1572 1573 #ifdef CONFIG_IP_MULTIPLE_TABLES 1574 fib4_rules_exit(net); 1575 #endif 1576 rtnl_unlock(); 1577 kfree(net->ipv4.fib_table_hash); 1578 fib4_notifier_exit(net); 1579 } 1580 1581 static int __net_init fib_net_init(struct net *net) 1582 { 1583 int error; 1584 1585 #ifdef CONFIG_IP_ROUTE_CLASSID 1586 net->ipv4.fib_num_tclassid_users = 0; 1587 #endif 1588 error = ip_fib_net_init(net); 1589 if (error < 0) 1590 goto out; 1591 error = nl_fib_lookup_init(net); 1592 if (error < 0) 1593 goto out_nlfl; 1594 error = fib_proc_init(net); 1595 if (error < 0) 1596 goto out_proc; 1597 out: 1598 return error; 1599 1600 out_proc: 1601 nl_fib_lookup_exit(net); 1602 out_nlfl: 1603 ip_fib_net_exit(net); 1604 goto out; 1605 } 1606 1607 static void __net_exit fib_net_exit(struct net *net) 1608 { 1609 fib_proc_exit(net); 1610 nl_fib_lookup_exit(net); 1611 ip_fib_net_exit(net); 1612 } 1613 1614 static struct pernet_operations fib_net_ops = { 1615 .init = fib_net_init, 1616 .exit = fib_net_exit, 1617 }; 1618 1619 void __init ip_fib_init(void) 1620 { 1621 fib_trie_init(); 1622 1623 register_pernet_subsys(&fib_net_ops); 1624 1625 register_netdevice_notifier(&fib_netdev_notifier); 1626 register_inetaddr_notifier(&fib_inetaddr_notifier); 1627 1628 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0); 1629 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0); 1630 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0); 1631 } 1632