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 51static 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 69fail: 70 fib_free_table(main_table); 71 return -ENOMEM; 72} 73#else 74 75struct 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} 108EXPORT_SYMBOL_GPL(fib_new_table); 109 110/* caller must hold either rtnl or rcu read lock */ 111struct 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 131static 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 151int 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 183void 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 */ 205static 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 236unsigned 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} 240EXPORT_SYMBOL(inet_addr_type_table); 241 242unsigned int inet_addr_type(struct net *net, __be32 addr) 243{ 244 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL); 245} 246EXPORT_SYMBOL(inet_addr_type); 247 248unsigned 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} 255EXPORT_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 */ 260unsigned 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} 268EXPORT_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 308bool 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} 333EXPORT_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 */ 343static 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_LINK; 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_LINK; 405 } 406 return ret; 407 408last_resort: 409 if (rpf) 410 goto e_rpf; 411 *itag = 0; 412 return 0; 413 414e_inval: 415 return -EINVAL; 416e_rpf: 417 return -EXDEV; 418} 419 420/* Ignore rp_filter for packets protected by IPsec. */ 421int 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 442ok: 443 *itag = 0; 444 return 0; 445 } 446 447full_check: 448 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag); 449} 450 451static inline __be32 sk_extract_addr(struct sockaddr *addr) 452{ 453 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 454} 455 456static 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 468static 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 (!cfg->fc_table) 577 cfg->fc_table = RT_TABLE_MAIN; 578 579 if (cmd == SIOCDELRT) 580 return 0; 581 582 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family) 583 return -EINVAL; 584 585 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 586 cfg->fc_scope = RT_SCOPE_LINK; 587 588 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 589 struct nlattr *mx; 590 int len = 0; 591 592 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL); 593 if (!mx) 594 return -ENOMEM; 595 596 if (rt->rt_flags & RTF_MTU) 597 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 598 599 if (rt->rt_flags & RTF_WINDOW) 600 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 601 602 if (rt->rt_flags & RTF_IRTT) 603 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 604 605 cfg->fc_mx = mx; 606 cfg->fc_mx_len = len; 607 } 608 609 return 0; 610} 611 612/* 613 * Handle IP routing ioctl calls. 614 * These are used to manipulate the routing tables 615 */ 616int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt) 617{ 618 struct fib_config cfg; 619 int err; 620 621 switch (cmd) { 622 case SIOCADDRT: /* Add a route */ 623 case SIOCDELRT: /* Delete a route */ 624 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 625 return -EPERM; 626 627 rtnl_lock(); 628 err = rtentry_to_fib_config(net, cmd, rt, &cfg); 629 if (err == 0) { 630 struct fib_table *tb; 631 632 if (cmd == SIOCDELRT) { 633 tb = fib_get_table(net, cfg.fc_table); 634 if (tb) 635 err = fib_table_delete(net, tb, &cfg, 636 NULL); 637 else 638 err = -ESRCH; 639 } else { 640 tb = fib_new_table(net, cfg.fc_table); 641 if (tb) 642 err = fib_table_insert(net, tb, 643 &cfg, NULL); 644 else 645 err = -ENOBUFS; 646 } 647 648 /* allocated by rtentry_to_fib_config() */ 649 kfree(cfg.fc_mx); 650 } 651 rtnl_unlock(); 652 return err; 653 } 654 return -EINVAL; 655} 656 657const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 658 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 }, 659 [RTA_DST] = { .type = NLA_U32 }, 660 [RTA_SRC] = { .type = NLA_U32 }, 661 [RTA_IIF] = { .type = NLA_U32 }, 662 [RTA_OIF] = { .type = NLA_U32 }, 663 [RTA_GATEWAY] = { .type = NLA_U32 }, 664 [RTA_PRIORITY] = { .type = NLA_U32 }, 665 [RTA_PREFSRC] = { .type = NLA_U32 }, 666 [RTA_METRICS] = { .type = NLA_NESTED }, 667 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 668 [RTA_FLOW] = { .type = NLA_U32 }, 669 [RTA_ENCAP_TYPE] = { .type = NLA_U16 }, 670 [RTA_ENCAP] = { .type = NLA_NESTED }, 671 [RTA_UID] = { .type = NLA_U32 }, 672 [RTA_MARK] = { .type = NLA_U32 }, 673 [RTA_TABLE] = { .type = NLA_U32 }, 674 [RTA_IP_PROTO] = { .type = NLA_U8 }, 675 [RTA_SPORT] = { .type = NLA_U16 }, 676 [RTA_DPORT] = { .type = NLA_U16 }, 677 [RTA_NH_ID] = { .type = NLA_U32 }, 678}; 679 680int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, 681 struct netlink_ext_ack *extack) 682{ 683 struct rtvia *via; 684 int alen; 685 686 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) { 687 NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA"); 688 return -EINVAL; 689 } 690 691 via = nla_data(nla); 692 alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr); 693 694 switch (via->rtvia_family) { 695 case AF_INET: 696 if (alen != sizeof(__be32)) { 697 NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA"); 698 return -EINVAL; 699 } 700 cfg->fc_gw_family = AF_INET; 701 cfg->fc_gw4 = *((__be32 *)via->rtvia_addr); 702 break; 703 case AF_INET6: 704#if IS_ENABLED(CONFIG_IPV6) 705 if (alen != sizeof(struct in6_addr)) { 706 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA"); 707 return -EINVAL; 708 } 709 cfg->fc_gw_family = AF_INET6; 710 cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr); 711#else 712 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel"); 713 return -EINVAL; 714#endif 715 break; 716 default: 717 NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA"); 718 return -EINVAL; 719 } 720 721 return 0; 722} 723 724static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 725 struct nlmsghdr *nlh, struct fib_config *cfg, 726 struct netlink_ext_ack *extack) 727{ 728 bool has_gw = false, has_via = false; 729 struct nlattr *attr; 730 int err, remaining; 731 struct rtmsg *rtm; 732 733 err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX, 734 rtm_ipv4_policy, extack); 735 if (err < 0) 736 goto errout; 737 738 memset(cfg, 0, sizeof(*cfg)); 739 740 rtm = nlmsg_data(nlh); 741 cfg->fc_dst_len = rtm->rtm_dst_len; 742 cfg->fc_tos = rtm->rtm_tos; 743 cfg->fc_table = rtm->rtm_table; 744 cfg->fc_protocol = rtm->rtm_protocol; 745 cfg->fc_scope = rtm->rtm_scope; 746 cfg->fc_type = rtm->rtm_type; 747 cfg->fc_flags = rtm->rtm_flags; 748 cfg->fc_nlflags = nlh->nlmsg_flags; 749 750 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid; 751 cfg->fc_nlinfo.nlh = nlh; 752 cfg->fc_nlinfo.nl_net = net; 753 754 if (cfg->fc_type > RTN_MAX) { 755 NL_SET_ERR_MSG(extack, "Invalid route type"); 756 err = -EINVAL; 757 goto errout; 758 } 759 760 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 761 switch (nla_type(attr)) { 762 case RTA_DST: 763 cfg->fc_dst = nla_get_be32(attr); 764 break; 765 case RTA_OIF: 766 cfg->fc_oif = nla_get_u32(attr); 767 break; 768 case RTA_GATEWAY: 769 has_gw = true; 770 cfg->fc_gw4 = nla_get_be32(attr); 771 if (cfg->fc_gw4) 772 cfg->fc_gw_family = AF_INET; 773 break; 774 case RTA_VIA: 775 has_via = true; 776 err = fib_gw_from_via(cfg, attr, extack); 777 if (err) 778 goto errout; 779 break; 780 case RTA_PRIORITY: 781 cfg->fc_priority = nla_get_u32(attr); 782 break; 783 case RTA_PREFSRC: 784 cfg->fc_prefsrc = nla_get_be32(attr); 785 break; 786 case RTA_METRICS: 787 cfg->fc_mx = nla_data(attr); 788 cfg->fc_mx_len = nla_len(attr); 789 break; 790 case RTA_MULTIPATH: 791 err = lwtunnel_valid_encap_type_attr(nla_data(attr), 792 nla_len(attr), 793 extack); 794 if (err < 0) 795 goto errout; 796 cfg->fc_mp = nla_data(attr); 797 cfg->fc_mp_len = nla_len(attr); 798 break; 799 case RTA_FLOW: 800 cfg->fc_flow = nla_get_u32(attr); 801 break; 802 case RTA_TABLE: 803 cfg->fc_table = nla_get_u32(attr); 804 break; 805 case RTA_ENCAP: 806 cfg->fc_encap = attr; 807 break; 808 case RTA_ENCAP_TYPE: 809 cfg->fc_encap_type = nla_get_u16(attr); 810 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, 811 extack); 812 if (err < 0) 813 goto errout; 814 break; 815 case RTA_NH_ID: 816 cfg->fc_nh_id = nla_get_u32(attr); 817 break; 818 } 819 } 820 821 if (cfg->fc_nh_id) { 822 if (cfg->fc_oif || cfg->fc_gw_family || 823 cfg->fc_encap || cfg->fc_mp) { 824 NL_SET_ERR_MSG(extack, 825 "Nexthop specification and nexthop id are mutually exclusive"); 826 return -EINVAL; 827 } 828 } 829 830 if (has_gw && has_via) { 831 NL_SET_ERR_MSG(extack, 832 "Nexthop configuration can not contain both GATEWAY and VIA"); 833 return -EINVAL; 834 } 835 836 if (!cfg->fc_table) 837 cfg->fc_table = RT_TABLE_MAIN; 838 839 return 0; 840errout: 841 return err; 842} 843 844static 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); 870errout: 871 return err; 872} 873 874static 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; 895errout: 896 return err; 897} 898 899int 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->flags = rtm->rtm_flags; 932 filter->protocol = rtm->rtm_protocol; 933 filter->rt_type = rtm->rtm_type; 934 filter->table_id = rtm->rtm_table; 935 936 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 937 rtm_ipv4_policy, extack); 938 if (err < 0) 939 return err; 940 941 for (i = 0; i <= RTA_MAX; ++i) { 942 int ifindex; 943 944 if (!tb[i]) 945 continue; 946 947 switch (i) { 948 case RTA_TABLE: 949 filter->table_id = nla_get_u32(tb[i]); 950 break; 951 case RTA_OIF: 952 ifindex = nla_get_u32(tb[i]); 953 filter->dev = __dev_get_by_index(net, ifindex); 954 if (!filter->dev) 955 return -ENODEV; 956 break; 957 default: 958 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request"); 959 return -EINVAL; 960 } 961 } 962 963 if (filter->flags || filter->protocol || filter->rt_type || 964 filter->table_id || filter->dev) { 965 filter->filter_set = 1; 966 cb->answer_flags = NLM_F_DUMP_FILTERED; 967 } 968 969 return 0; 970} 971EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req); 972 973static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 974{ 975 struct fib_dump_filter filter = { .dump_routes = true, 976 .dump_exceptions = true }; 977 const struct nlmsghdr *nlh = cb->nlh; 978 struct net *net = sock_net(skb->sk); 979 unsigned int h, s_h; 980 unsigned int e = 0, s_e; 981 struct fib_table *tb; 982 struct hlist_head *head; 983 int dumped = 0, err; 984 985 if (cb->strict_check) { 986 err = ip_valid_fib_dump_req(net, nlh, &filter, cb); 987 if (err < 0) 988 return err; 989 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 990 struct rtmsg *rtm = nlmsg_data(nlh); 991 992 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED); 993 } 994 995 /* ipv4 does not use prefix flag */ 996 if (filter.flags & RTM_F_PREFIX) 997 return skb->len; 998 999 if (filter.table_id) { 1000 tb = fib_get_table(net, filter.table_id); 1001 if (!tb) { 1002 if (rtnl_msg_family(cb->nlh) != PF_INET) 1003 return skb->len; 1004 1005 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist"); 1006 return -ENOENT; 1007 } 1008 1009 rcu_read_lock(); 1010 err = fib_table_dump(tb, skb, cb, &filter); 1011 rcu_read_unlock(); 1012 return skb->len ? : err; 1013 } 1014 1015 s_h = cb->args[0]; 1016 s_e = cb->args[1]; 1017 1018 rcu_read_lock(); 1019 1020 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 1021 e = 0; 1022 head = &net->ipv4.fib_table_hash[h]; 1023 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 1024 if (e < s_e) 1025 goto next; 1026 if (dumped) 1027 memset(&cb->args[2], 0, sizeof(cb->args) - 1028 2 * sizeof(cb->args[0])); 1029 err = fib_table_dump(tb, skb, cb, &filter); 1030 if (err < 0) { 1031 if (likely(skb->len)) 1032 goto out; 1033 1034 goto out_err; 1035 } 1036 dumped = 1; 1037next: 1038 e++; 1039 } 1040 } 1041out: 1042 err = skb->len; 1043out_err: 1044 rcu_read_unlock(); 1045 1046 cb->args[1] = e; 1047 cb->args[0] = h; 1048 1049 return err; 1050} 1051 1052/* Prepare and feed intra-kernel routing request. 1053 * Really, it should be netlink message, but :-( netlink 1054 * can be not configured, so that we feed it directly 1055 * to fib engine. It is legal, because all events occur 1056 * only when netlink is already locked. 1057 */ 1058static void fib_magic(int cmd, int type, __be32 dst, int dst_len, 1059 struct in_ifaddr *ifa, u32 rt_priority) 1060{ 1061 struct net *net = dev_net(ifa->ifa_dev->dev); 1062 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev); 1063 struct fib_table *tb; 1064 struct fib_config cfg = { 1065 .fc_protocol = RTPROT_KERNEL, 1066 .fc_type = type, 1067 .fc_dst = dst, 1068 .fc_dst_len = dst_len, 1069 .fc_priority = rt_priority, 1070 .fc_prefsrc = ifa->ifa_local, 1071 .fc_oif = ifa->ifa_dev->dev->ifindex, 1072 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 1073 .fc_nlinfo = { 1074 .nl_net = net, 1075 }, 1076 }; 1077 1078 if (!tb_id) 1079 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL; 1080 1081 tb = fib_new_table(net, tb_id); 1082 if (!tb) 1083 return; 1084 1085 cfg.fc_table = tb->tb_id; 1086 1087 if (type != RTN_LOCAL) 1088 cfg.fc_scope = RT_SCOPE_LINK; 1089 else 1090 cfg.fc_scope = RT_SCOPE_HOST; 1091 1092 if (cmd == RTM_NEWROUTE) 1093 fib_table_insert(net, tb, &cfg, NULL); 1094 else 1095 fib_table_delete(net, tb, &cfg, NULL); 1096} 1097 1098void fib_add_ifaddr(struct in_ifaddr *ifa) 1099{ 1100 struct in_device *in_dev = ifa->ifa_dev; 1101 struct net_device *dev = in_dev->dev; 1102 struct in_ifaddr *prim = ifa; 1103 __be32 mask = ifa->ifa_mask; 1104 __be32 addr = ifa->ifa_local; 1105 __be32 prefix = ifa->ifa_address & mask; 1106 1107 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1108 prim = inet_ifa_byprefix(in_dev, prefix, mask); 1109 if (!prim) { 1110 pr_warn("%s: bug: prim == NULL\n", __func__); 1111 return; 1112 } 1113 } 1114 1115 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0); 1116 1117 if (!(dev->flags & IFF_UP)) 1118 return; 1119 1120 /* Add broadcast address, if it is explicitly assigned. */ 1121 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) { 1122 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1123 prim, 0); 1124 arp_invalidate(dev, ifa->ifa_broadcast, false); 1125 } 1126 1127 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 1128 (prefix != addr || ifa->ifa_prefixlen < 32)) { 1129 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1130 fib_magic(RTM_NEWROUTE, 1131 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1132 prefix, ifa->ifa_prefixlen, prim, 1133 ifa->ifa_rt_priority); 1134 1135 /* Add network specific broadcasts, when it takes a sense */ 1136 if (ifa->ifa_prefixlen < 31) { 1137 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, 1138 prim, 0); 1139 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 1140 32, prim, 0); 1141 arp_invalidate(dev, prefix | ~mask, false); 1142 } 1143 } 1144} 1145 1146void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric) 1147{ 1148 __be32 prefix = ifa->ifa_address & ifa->ifa_mask; 1149 struct in_device *in_dev = ifa->ifa_dev; 1150 struct net_device *dev = in_dev->dev; 1151 1152 if (!(dev->flags & IFF_UP) || 1153 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) || 1154 ipv4_is_zeronet(prefix) || 1155 (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32)) 1156 return; 1157 1158 /* add the new */ 1159 fib_magic(RTM_NEWROUTE, 1160 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1161 prefix, ifa->ifa_prefixlen, ifa, new_metric); 1162 1163 /* delete the old */ 1164 fib_magic(RTM_DELROUTE, 1165 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1166 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority); 1167} 1168 1169/* Delete primary or secondary address. 1170 * Optionally, on secondary address promotion consider the addresses 1171 * from subnet iprim as deleted, even if they are in device list. 1172 * In this case the secondary ifa can be in device list. 1173 */ 1174void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 1175{ 1176 struct in_device *in_dev = ifa->ifa_dev; 1177 struct net_device *dev = in_dev->dev; 1178 struct in_ifaddr *ifa1; 1179 struct in_ifaddr *prim = ifa, *prim1 = NULL; 1180 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 1181 __be32 any = ifa->ifa_address & ifa->ifa_mask; 1182#define LOCAL_OK 1 1183#define BRD_OK 2 1184#define BRD0_OK 4 1185#define BRD1_OK 8 1186 unsigned int ok = 0; 1187 int subnet = 0; /* Primary network */ 1188 int gone = 1; /* Address is missing */ 1189 int same_prefsrc = 0; /* Another primary with same IP */ 1190 1191 if (ifa->ifa_flags & IFA_F_SECONDARY) { 1192 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 1193 if (!prim) { 1194 /* if the device has been deleted, we don't perform 1195 * address promotion 1196 */ 1197 if (!in_dev->dead) 1198 pr_warn("%s: bug: prim == NULL\n", __func__); 1199 return; 1200 } 1201 if (iprim && iprim != prim) { 1202 pr_warn("%s: bug: iprim != prim\n", __func__); 1203 return; 1204 } 1205 } else if (!ipv4_is_zeronet(any) && 1206 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 1207 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) 1208 fib_magic(RTM_DELROUTE, 1209 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 1210 any, ifa->ifa_prefixlen, prim, 0); 1211 subnet = 1; 1212 } 1213 1214 if (in_dev->dead) 1215 goto no_promotions; 1216 1217 /* Deletion is more complicated than add. 1218 * We should take care of not to delete too much :-) 1219 * 1220 * Scan address list to be sure that addresses are really gone. 1221 */ 1222 rcu_read_lock(); 1223 in_dev_for_each_ifa_rcu(ifa1, in_dev) { 1224 if (ifa1 == ifa) { 1225 /* promotion, keep the IP */ 1226 gone = 0; 1227 continue; 1228 } 1229 /* Ignore IFAs from our subnet */ 1230 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 1231 inet_ifa_match(ifa1->ifa_address, iprim)) 1232 continue; 1233 1234 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 1235 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 1236 /* Another address from our subnet? */ 1237 if (ifa1->ifa_mask == prim->ifa_mask && 1238 inet_ifa_match(ifa1->ifa_address, prim)) 1239 prim1 = prim; 1240 else { 1241 /* We reached the secondaries, so 1242 * same_prefsrc should be determined. 1243 */ 1244 if (!same_prefsrc) 1245 continue; 1246 /* Search new prim1 if ifa1 is not 1247 * using the current prim1 1248 */ 1249 if (!prim1 || 1250 ifa1->ifa_mask != prim1->ifa_mask || 1251 !inet_ifa_match(ifa1->ifa_address, prim1)) 1252 prim1 = inet_ifa_byprefix(in_dev, 1253 ifa1->ifa_address, 1254 ifa1->ifa_mask); 1255 if (!prim1) 1256 continue; 1257 if (prim1->ifa_local != prim->ifa_local) 1258 continue; 1259 } 1260 } else { 1261 if (prim->ifa_local != ifa1->ifa_local) 1262 continue; 1263 prim1 = ifa1; 1264 if (prim != prim1) 1265 same_prefsrc = 1; 1266 } 1267 if (ifa->ifa_local == ifa1->ifa_local) 1268 ok |= LOCAL_OK; 1269 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 1270 ok |= BRD_OK; 1271 if (brd == ifa1->ifa_broadcast) 1272 ok |= BRD1_OK; 1273 if (any == ifa1->ifa_broadcast) 1274 ok |= BRD0_OK; 1275 /* primary has network specific broadcasts */ 1276 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 1277 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 1278 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 1279 1280 if (!ipv4_is_zeronet(any1)) { 1281 if (ifa->ifa_broadcast == brd1 || 1282 ifa->ifa_broadcast == any1) 1283 ok |= BRD_OK; 1284 if (brd == brd1 || brd == any1) 1285 ok |= BRD1_OK; 1286 if (any == brd1 || any == any1) 1287 ok |= BRD0_OK; 1288 } 1289 } 1290 } 1291 rcu_read_unlock(); 1292 1293no_promotions: 1294 if (!(ok & BRD_OK)) 1295 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, 1296 prim, 0); 1297 if (subnet && ifa->ifa_prefixlen < 31) { 1298 if (!(ok & BRD1_OK)) 1299 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, 1300 prim, 0); 1301 if (!(ok & BRD0_OK)) 1302 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, 1303 prim, 0); 1304 } 1305 if (!(ok & LOCAL_OK)) { 1306 unsigned int addr_type; 1307 1308 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0); 1309 1310 /* Check, that this local address finally disappeared. */ 1311 addr_type = inet_addr_type_dev_table(dev_net(dev), dev, 1312 ifa->ifa_local); 1313 if (gone && addr_type != RTN_LOCAL) { 1314 /* And the last, but not the least thing. 1315 * We must flush stray FIB entries. 1316 * 1317 * First of all, we scan fib_info list searching 1318 * for stray nexthop entries, then ignite fib_flush. 1319 */ 1320 if (fib_sync_down_addr(dev, ifa->ifa_local)) 1321 fib_flush(dev_net(dev)); 1322 } 1323 } 1324#undef LOCAL_OK 1325#undef BRD_OK 1326#undef BRD0_OK 1327#undef BRD1_OK 1328} 1329 1330static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn) 1331{ 1332 1333 struct fib_result res; 1334 struct flowi4 fl4 = { 1335 .flowi4_mark = frn->fl_mark, 1336 .daddr = frn->fl_addr, 1337 .flowi4_tos = frn->fl_tos, 1338 .flowi4_scope = frn->fl_scope, 1339 }; 1340 struct fib_table *tb; 1341 1342 rcu_read_lock(); 1343 1344 tb = fib_get_table(net, frn->tb_id_in); 1345 1346 frn->err = -ENOENT; 1347 if (tb) { 1348 local_bh_disable(); 1349 1350 frn->tb_id = tb->tb_id; 1351 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 1352 1353 if (!frn->err) { 1354 frn->prefixlen = res.prefixlen; 1355 frn->nh_sel = res.nh_sel; 1356 frn->type = res.type; 1357 frn->scope = res.scope; 1358 } 1359 local_bh_enable(); 1360 } 1361 1362 rcu_read_unlock(); 1363} 1364 1365static void nl_fib_input(struct sk_buff *skb) 1366{ 1367 struct net *net; 1368 struct fib_result_nl *frn; 1369 struct nlmsghdr *nlh; 1370 u32 portid; 1371 1372 net = sock_net(skb->sk); 1373 nlh = nlmsg_hdr(skb); 1374 if (skb->len < nlmsg_total_size(sizeof(*frn)) || 1375 skb->len < nlh->nlmsg_len || 1376 nlmsg_len(nlh) < sizeof(*frn)) 1377 return; 1378 1379 skb = netlink_skb_clone(skb, GFP_KERNEL); 1380 if (!skb) 1381 return; 1382 nlh = nlmsg_hdr(skb); 1383 1384 frn = (struct fib_result_nl *) nlmsg_data(nlh); 1385 nl_fib_lookup(net, frn); 1386 1387 portid = NETLINK_CB(skb).portid; /* netlink portid */ 1388 NETLINK_CB(skb).portid = 0; /* from kernel */ 1389 NETLINK_CB(skb).dst_group = 0; /* unicast */ 1390 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT); 1391} 1392 1393static int __net_init nl_fib_lookup_init(struct net *net) 1394{ 1395 struct sock *sk; 1396 struct netlink_kernel_cfg cfg = { 1397 .input = nl_fib_input, 1398 }; 1399 1400 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg); 1401 if (!sk) 1402 return -EAFNOSUPPORT; 1403 net->ipv4.fibnl = sk; 1404 return 0; 1405} 1406 1407static void nl_fib_lookup_exit(struct net *net) 1408{ 1409 netlink_kernel_release(net->ipv4.fibnl); 1410 net->ipv4.fibnl = NULL; 1411} 1412 1413static void fib_disable_ip(struct net_device *dev, unsigned long event, 1414 bool force) 1415{ 1416 if (fib_sync_down_dev(dev, event, force)) 1417 fib_flush(dev_net(dev)); 1418 else 1419 rt_cache_flush(dev_net(dev)); 1420 arp_ifdown(dev); 1421} 1422 1423static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 1424{ 1425 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 1426 struct net_device *dev = ifa->ifa_dev->dev; 1427 struct net *net = dev_net(dev); 1428 1429 switch (event) { 1430 case NETDEV_UP: 1431 fib_add_ifaddr(ifa); 1432#ifdef CONFIG_IP_ROUTE_MULTIPATH 1433 fib_sync_up(dev, RTNH_F_DEAD); 1434#endif 1435 atomic_inc(&net->ipv4.dev_addr_genid); 1436 rt_cache_flush(dev_net(dev)); 1437 break; 1438 case NETDEV_DOWN: 1439 fib_del_ifaddr(ifa, NULL); 1440 atomic_inc(&net->ipv4.dev_addr_genid); 1441 if (!ifa->ifa_dev->ifa_list) { 1442 /* Last address was deleted from this interface. 1443 * Disable IP. 1444 */ 1445 fib_disable_ip(dev, event, true); 1446 } else { 1447 rt_cache_flush(dev_net(dev)); 1448 } 1449 break; 1450 } 1451 return NOTIFY_DONE; 1452} 1453 1454static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1455{ 1456 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1457 struct netdev_notifier_changeupper_info *upper_info = ptr; 1458 struct netdev_notifier_info_ext *info_ext = ptr; 1459 struct in_device *in_dev; 1460 struct net *net = dev_net(dev); 1461 struct in_ifaddr *ifa; 1462 unsigned int flags; 1463 1464 if (event == NETDEV_UNREGISTER) { 1465 fib_disable_ip(dev, event, true); 1466 rt_flush_dev(dev); 1467 return NOTIFY_DONE; 1468 } 1469 1470 in_dev = __in_dev_get_rtnl(dev); 1471 if (!in_dev) 1472 return NOTIFY_DONE; 1473 1474 switch (event) { 1475 case NETDEV_UP: 1476 in_dev_for_each_ifa_rtnl(ifa, in_dev) { 1477 fib_add_ifaddr(ifa); 1478 } 1479#ifdef CONFIG_IP_ROUTE_MULTIPATH 1480 fib_sync_up(dev, RTNH_F_DEAD); 1481#endif 1482 atomic_inc(&net->ipv4.dev_addr_genid); 1483 rt_cache_flush(net); 1484 break; 1485 case NETDEV_DOWN: 1486 fib_disable_ip(dev, event, false); 1487 break; 1488 case NETDEV_CHANGE: 1489 flags = dev_get_flags(dev); 1490 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1491 fib_sync_up(dev, RTNH_F_LINKDOWN); 1492 else 1493 fib_sync_down_dev(dev, event, false); 1494 rt_cache_flush(net); 1495 break; 1496 case NETDEV_CHANGEMTU: 1497 fib_sync_mtu(dev, info_ext->ext.mtu); 1498 rt_cache_flush(net); 1499 break; 1500 case NETDEV_CHANGEUPPER: 1501 upper_info = ptr; 1502 /* flush all routes if dev is linked to or unlinked from 1503 * an L3 master device (e.g., VRF) 1504 */ 1505 if (upper_info->upper_dev && 1506 netif_is_l3_master(upper_info->upper_dev)) 1507 fib_disable_ip(dev, NETDEV_DOWN, true); 1508 break; 1509 } 1510 return NOTIFY_DONE; 1511} 1512 1513static struct notifier_block fib_inetaddr_notifier = { 1514 .notifier_call = fib_inetaddr_event, 1515}; 1516 1517static struct notifier_block fib_netdev_notifier = { 1518 .notifier_call = fib_netdev_event, 1519}; 1520 1521static int __net_init ip_fib_net_init(struct net *net) 1522{ 1523 int err; 1524 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1525 1526 err = fib4_notifier_init(net); 1527 if (err) 1528 return err; 1529 1530 /* Avoid false sharing : Use at least a full cache line */ 1531 size = max_t(size_t, size, L1_CACHE_BYTES); 1532 1533 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1534 if (!net->ipv4.fib_table_hash) { 1535 err = -ENOMEM; 1536 goto err_table_hash_alloc; 1537 } 1538 1539 err = fib4_rules_init(net); 1540 if (err < 0) 1541 goto err_rules_init; 1542 return 0; 1543 1544err_rules_init: 1545 kfree(net->ipv4.fib_table_hash); 1546err_table_hash_alloc: 1547 fib4_notifier_exit(net); 1548 return err; 1549} 1550 1551static void ip_fib_net_exit(struct net *net) 1552{ 1553 int i; 1554 1555 rtnl_lock(); 1556#ifdef CONFIG_IP_MULTIPLE_TABLES 1557 RCU_INIT_POINTER(net->ipv4.fib_main, NULL); 1558 RCU_INIT_POINTER(net->ipv4.fib_default, NULL); 1559#endif 1560 /* Destroy the tables in reverse order to guarantee that the 1561 * local table, ID 255, is destroyed before the main table, ID 1562 * 254. This is necessary as the local table may contain 1563 * references to data contained in the main table. 1564 */ 1565 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) { 1566 struct hlist_head *head = &net->ipv4.fib_table_hash[i]; 1567 struct hlist_node *tmp; 1568 struct fib_table *tb; 1569 1570 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) { 1571 hlist_del(&tb->tb_hlist); 1572 fib_table_flush(net, tb, true); 1573 fib_free_table(tb); 1574 } 1575 } 1576 1577#ifdef CONFIG_IP_MULTIPLE_TABLES 1578 fib4_rules_exit(net); 1579#endif 1580 rtnl_unlock(); 1581 kfree(net->ipv4.fib_table_hash); 1582 fib4_notifier_exit(net); 1583} 1584 1585static int __net_init fib_net_init(struct net *net) 1586{ 1587 int error; 1588 1589#ifdef CONFIG_IP_ROUTE_CLASSID 1590 atomic_set(&net->ipv4.fib_num_tclassid_users, 0); 1591#endif 1592 error = ip_fib_net_init(net); 1593 if (error < 0) 1594 goto out; 1595 error = nl_fib_lookup_init(net); 1596 if (error < 0) 1597 goto out_nlfl; 1598 error = fib_proc_init(net); 1599 if (error < 0) 1600 goto out_proc; 1601out: 1602 return error; 1603 1604out_proc: 1605 nl_fib_lookup_exit(net); 1606out_nlfl: 1607 ip_fib_net_exit(net); 1608 goto out; 1609} 1610 1611static void __net_exit fib_net_exit(struct net *net) 1612{ 1613 fib_proc_exit(net); 1614 nl_fib_lookup_exit(net); 1615 ip_fib_net_exit(net); 1616} 1617 1618static struct pernet_operations fib_net_ops = { 1619 .init = fib_net_init, 1620 .exit = fib_net_exit, 1621}; 1622 1623void __init ip_fib_init(void) 1624{ 1625 fib_trie_init(); 1626 1627 register_pernet_subsys(&fib_net_ops); 1628 1629 register_netdevice_notifier(&fib_netdev_notifier); 1630 register_inetaddr_notifier(&fib_inetaddr_notifier); 1631 1632 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0); 1633 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0); 1634 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0); 1635} 1636