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