1/* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * IPv4 Forwarding Information Base: FIB frontend. 7 * 8 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16#include <linux/module.h> 17#include <asm/uaccess.h> 18#include <linux/bitops.h> 19#include <linux/capability.h> 20#include <linux/types.h> 21#include <linux/kernel.h> 22#include <linux/mm.h> 23#include <linux/string.h> 24#include <linux/socket.h> 25#include <linux/sockios.h> 26#include <linux/errno.h> 27#include <linux/in.h> 28#include <linux/inet.h> 29#include <linux/inetdevice.h> 30#include <linux/netdevice.h> 31#include <linux/if_addr.h> 32#include <linux/if_arp.h> 33#include <linux/skbuff.h> 34#include <linux/cache.h> 35#include <linux/init.h> 36#include <linux/list.h> 37#include <linux/slab.h> 38 39#include <net/ip.h> 40#include <net/protocol.h> 41#include <net/route.h> 42#include <net/tcp.h> 43#include <net/sock.h> 44#include <net/arp.h> 45#include <net/ip_fib.h> 46#include <net/rtnetlink.h> 47#include <net/xfrm.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) 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_LOCAL: 95 rcu_assign_pointer(net->ipv4.fib_local, tb); 96 break; 97 case RT_TABLE_MAIN: 98 rcu_assign_pointer(net->ipv4.fib_main, tb); 99 break; 100 case RT_TABLE_DEFAULT: 101 rcu_assign_pointer(net->ipv4.fib_default, tb); 102 break; 103 default: 104 break; 105 } 106 107 h = id & (FIB_TABLE_HASHSZ - 1); 108 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]); 109 return tb; 110} 111 112/* caller must hold either rtnl or rcu read lock */ 113struct fib_table *fib_get_table(struct net *net, u32 id) 114{ 115 struct fib_table *tb; 116 struct hlist_head *head; 117 unsigned int h; 118 119 if (id == 0) 120 id = RT_TABLE_MAIN; 121 h = id & (FIB_TABLE_HASHSZ - 1); 122 123 head = &net->ipv4.fib_table_hash[h]; 124 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 125 if (tb->tb_id == id) 126 return tb; 127 } 128 return NULL; 129} 130#endif /* CONFIG_IP_MULTIPLE_TABLES */ 131 132static void fib_replace_table(struct net *net, struct fib_table *old, 133 struct fib_table *new) 134{ 135#ifdef CONFIG_IP_MULTIPLE_TABLES 136 switch (new->tb_id) { 137 case RT_TABLE_LOCAL: 138 rcu_assign_pointer(net->ipv4.fib_local, new); 139 break; 140 case RT_TABLE_MAIN: 141 rcu_assign_pointer(net->ipv4.fib_main, new); 142 break; 143 case RT_TABLE_DEFAULT: 144 rcu_assign_pointer(net->ipv4.fib_default, new); 145 break; 146 default: 147 break; 148 } 149 150#endif 151 /* replace the old table in the hlist */ 152 hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist); 153} 154 155int fib_unmerge(struct net *net) 156{ 157 struct fib_table *old, *new; 158 159 /* attempt to fetch local table if it has been allocated */ 160 old = fib_get_table(net, RT_TABLE_LOCAL); 161 if (!old) 162 return 0; 163 164 new = fib_trie_unmerge(old); 165 if (!new) 166 return -ENOMEM; 167 168 /* replace merged table with clean table */ 169 if (new != old) { 170 fib_replace_table(net, old, new); 171 fib_free_table(old); 172 } 173 174 return 0; 175} 176 177static void fib_flush(struct net *net) 178{ 179 int flushed = 0; 180 unsigned int h; 181 182 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 183 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 184 struct hlist_node *tmp; 185 struct fib_table *tb; 186 187 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) 188 flushed += fib_table_flush(tb); 189 } 190 191 if (flushed) 192 rt_cache_flush(net); 193} 194 195void fib_flush_external(struct net *net) 196{ 197 struct fib_table *tb; 198 struct hlist_head *head; 199 unsigned int h; 200 201 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 202 head = &net->ipv4.fib_table_hash[h]; 203 hlist_for_each_entry(tb, head, tb_hlist) 204 fib_table_flush_external(tb); 205 } 206} 207 208/* 209 * Find address type as if only "dev" was present in the system. If 210 * on_dev is NULL then all interfaces are taken into consideration. 211 */ 212static inline unsigned int __inet_dev_addr_type(struct net *net, 213 const struct net_device *dev, 214 __be32 addr) 215{ 216 struct flowi4 fl4 = { .daddr = addr }; 217 struct fib_result res; 218 unsigned int ret = RTN_BROADCAST; 219 struct fib_table *local_table; 220 221 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr)) 222 return RTN_BROADCAST; 223 if (ipv4_is_multicast(addr)) 224 return RTN_MULTICAST; 225 226 rcu_read_lock(); 227 228 local_table = fib_get_table(net, RT_TABLE_LOCAL); 229 if (local_table) { 230 ret = RTN_UNICAST; 231 if (!fib_table_lookup(local_table, &fl4, &res, FIB_LOOKUP_NOREF)) { 232 if (!dev || dev == res.fi->fib_dev) 233 ret = res.type; 234 } 235 } 236 237 rcu_read_unlock(); 238 return ret; 239} 240 241unsigned int inet_addr_type(struct net *net, __be32 addr) 242{ 243 return __inet_dev_addr_type(net, NULL, addr); 244} 245EXPORT_SYMBOL(inet_addr_type); 246 247unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, 248 __be32 addr) 249{ 250 return __inet_dev_addr_type(net, dev, addr); 251} 252EXPORT_SYMBOL(inet_dev_addr_type); 253 254__be32 fib_compute_spec_dst(struct sk_buff *skb) 255{ 256 struct net_device *dev = skb->dev; 257 struct in_device *in_dev; 258 struct fib_result res; 259 struct rtable *rt; 260 struct flowi4 fl4; 261 struct net *net; 262 int scope; 263 264 rt = skb_rtable(skb); 265 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) == 266 RTCF_LOCAL) 267 return ip_hdr(skb)->daddr; 268 269 in_dev = __in_dev_get_rcu(dev); 270 BUG_ON(!in_dev); 271 272 net = dev_net(dev); 273 274 scope = RT_SCOPE_UNIVERSE; 275 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) { 276 fl4.flowi4_oif = 0; 277 fl4.flowi4_iif = LOOPBACK_IFINDEX; 278 fl4.daddr = ip_hdr(skb)->saddr; 279 fl4.saddr = 0; 280 fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos); 281 fl4.flowi4_scope = scope; 282 fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0; 283 if (!fib_lookup(net, &fl4, &res)) 284 return FIB_RES_PREFSRC(net, res); 285 } else { 286 scope = RT_SCOPE_LINK; 287 } 288 289 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope); 290} 291 292/* Given (packet source, input interface) and optional (dst, oif, tos): 293 * - (main) check, that source is valid i.e. not broadcast or our local 294 * address. 295 * - figure out what "logical" interface this packet arrived 296 * and calculate "specific destination" address. 297 * - check, that packet arrived from expected physical interface. 298 * called with rcu_read_lock() 299 */ 300static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 301 u8 tos, int oif, struct net_device *dev, 302 int rpf, struct in_device *idev, u32 *itag) 303{ 304 int ret, no_addr; 305 struct fib_result res; 306 struct flowi4 fl4; 307 struct net *net; 308 bool dev_match; 309 310 fl4.flowi4_oif = 0; 311 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX; 312 fl4.daddr = src; 313 fl4.saddr = dst; 314 fl4.flowi4_tos = tos; 315 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 316 317 no_addr = idev->ifa_list == NULL; 318 319 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0; 320 321 net = dev_net(dev); 322 if (fib_lookup(net, &fl4, &res)) 323 goto last_resort; 324 if (res.type != RTN_UNICAST && 325 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev))) 326 goto e_inval; 327 if (!rpf && !fib_num_tclassid_users(dev_net(dev)) && 328 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) 329 goto last_resort; 330 fib_combine_itag(itag, &res); 331 dev_match = false; 332 333#ifdef CONFIG_IP_ROUTE_MULTIPATH 334 for (ret = 0; ret < res.fi->fib_nhs; ret++) { 335 struct fib_nh *nh = &res.fi->fib_nh[ret]; 336 337 if (nh->nh_dev == dev) { 338 dev_match = true; 339 break; 340 } 341 } 342#else 343 if (FIB_RES_DEV(res) == dev) 344 dev_match = true; 345#endif 346 if (dev_match) { 347 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 348 return ret; 349 } 350 if (no_addr) 351 goto last_resort; 352 if (rpf == 1) 353 goto e_rpf; 354 fl4.flowi4_oif = dev->ifindex; 355 356 ret = 0; 357 if (fib_lookup(net, &fl4, &res) == 0) { 358 if (res.type == RTN_UNICAST) 359 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 360 } 361 return ret; 362 363last_resort: 364 if (rpf) 365 goto e_rpf; 366 *itag = 0; 367 return 0; 368 369e_inval: 370 return -EINVAL; 371e_rpf: 372 return -EXDEV; 373} 374 375/* Ignore rp_filter for packets protected by IPsec. */ 376int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 377 u8 tos, int oif, struct net_device *dev, 378 struct in_device *idev, u32 *itag) 379{ 380 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev); 381 382 if (!r && !fib_num_tclassid_users(dev_net(dev)) && 383 IN_DEV_ACCEPT_LOCAL(idev) && 384 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) { 385 *itag = 0; 386 return 0; 387 } 388 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag); 389} 390 391static inline __be32 sk_extract_addr(struct sockaddr *addr) 392{ 393 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 394} 395 396static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 397{ 398 struct nlattr *nla; 399 400 nla = (struct nlattr *) ((char *) mx + len); 401 nla->nla_type = type; 402 nla->nla_len = nla_attr_size(4); 403 *(u32 *) nla_data(nla) = value; 404 405 return len + nla_total_size(4); 406} 407 408static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 409 struct fib_config *cfg) 410{ 411 __be32 addr; 412 int plen; 413 414 memset(cfg, 0, sizeof(*cfg)); 415 cfg->fc_nlinfo.nl_net = net; 416 417 if (rt->rt_dst.sa_family != AF_INET) 418 return -EAFNOSUPPORT; 419 420 /* 421 * Check mask for validity: 422 * a) it must be contiguous. 423 * b) destination must have all host bits clear. 424 * c) if application forgot to set correct family (AF_INET), 425 * reject request unless it is absolutely clear i.e. 426 * both family and mask are zero. 427 */ 428 plen = 32; 429 addr = sk_extract_addr(&rt->rt_dst); 430 if (!(rt->rt_flags & RTF_HOST)) { 431 __be32 mask = sk_extract_addr(&rt->rt_genmask); 432 433 if (rt->rt_genmask.sa_family != AF_INET) { 434 if (mask || rt->rt_genmask.sa_family) 435 return -EAFNOSUPPORT; 436 } 437 438 if (bad_mask(mask, addr)) 439 return -EINVAL; 440 441 plen = inet_mask_len(mask); 442 } 443 444 cfg->fc_dst_len = plen; 445 cfg->fc_dst = addr; 446 447 if (cmd != SIOCDELRT) { 448 cfg->fc_nlflags = NLM_F_CREATE; 449 cfg->fc_protocol = RTPROT_BOOT; 450 } 451 452 if (rt->rt_metric) 453 cfg->fc_priority = rt->rt_metric - 1; 454 455 if (rt->rt_flags & RTF_REJECT) { 456 cfg->fc_scope = RT_SCOPE_HOST; 457 cfg->fc_type = RTN_UNREACHABLE; 458 return 0; 459 } 460 461 cfg->fc_scope = RT_SCOPE_NOWHERE; 462 cfg->fc_type = RTN_UNICAST; 463 464 if (rt->rt_dev) { 465 char *colon; 466 struct net_device *dev; 467 char devname[IFNAMSIZ]; 468 469 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 470 return -EFAULT; 471 472 devname[IFNAMSIZ-1] = 0; 473 colon = strchr(devname, ':'); 474 if (colon) 475 *colon = 0; 476 dev = __dev_get_by_name(net, devname); 477 if (!dev) 478 return -ENODEV; 479 cfg->fc_oif = dev->ifindex; 480 if (colon) { 481 struct in_ifaddr *ifa; 482 struct in_device *in_dev = __in_dev_get_rtnl(dev); 483 if (!in_dev) 484 return -ENODEV; 485 *colon = ':'; 486 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) 487 if (strcmp(ifa->ifa_label, devname) == 0) 488 break; 489 if (!ifa) 490 return -ENODEV; 491 cfg->fc_prefsrc = ifa->ifa_local; 492 } 493 } 494 495 addr = sk_extract_addr(&rt->rt_gateway); 496 if (rt->rt_gateway.sa_family == AF_INET && addr) { 497 cfg->fc_gw = addr; 498 if (rt->rt_flags & RTF_GATEWAY && 499 inet_addr_type(net, addr) == RTN_UNICAST) 500 cfg->fc_scope = RT_SCOPE_UNIVERSE; 501 } 502 503 if (cmd == SIOCDELRT) 504 return 0; 505 506 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw) 507 return -EINVAL; 508 509 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 510 cfg->fc_scope = RT_SCOPE_LINK; 511 512 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 513 struct nlattr *mx; 514 int len = 0; 515 516 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL); 517 if (!mx) 518 return -ENOMEM; 519 520 if (rt->rt_flags & RTF_MTU) 521 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 522 523 if (rt->rt_flags & RTF_WINDOW) 524 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 525 526 if (rt->rt_flags & RTF_IRTT) 527 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 528 529 cfg->fc_mx = mx; 530 cfg->fc_mx_len = len; 531 } 532 533 return 0; 534} 535 536/* 537 * Handle IP routing ioctl calls. 538 * These are used to manipulate the routing tables 539 */ 540int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg) 541{ 542 struct fib_config cfg; 543 struct rtentry rt; 544 int err; 545 546 switch (cmd) { 547 case SIOCADDRT: /* Add a route */ 548 case SIOCDELRT: /* Delete a route */ 549 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 550 return -EPERM; 551 552 if (copy_from_user(&rt, arg, sizeof(rt))) 553 return -EFAULT; 554 555 rtnl_lock(); 556 err = rtentry_to_fib_config(net, cmd, &rt, &cfg); 557 if (err == 0) { 558 struct fib_table *tb; 559 560 if (cmd == SIOCDELRT) { 561 tb = fib_get_table(net, cfg.fc_table); 562 if (tb) 563 err = fib_table_delete(tb, &cfg); 564 else 565 err = -ESRCH; 566 } else { 567 tb = fib_new_table(net, cfg.fc_table); 568 if (tb) 569 err = fib_table_insert(tb, &cfg); 570 else 571 err = -ENOBUFS; 572 } 573 574 /* allocated by rtentry_to_fib_config() */ 575 kfree(cfg.fc_mx); 576 } 577 rtnl_unlock(); 578 return err; 579 } 580 return -EINVAL; 581} 582 583const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 584 [RTA_DST] = { .type = NLA_U32 }, 585 [RTA_SRC] = { .type = NLA_U32 }, 586 [RTA_IIF] = { .type = NLA_U32 }, 587 [RTA_OIF] = { .type = NLA_U32 }, 588 [RTA_GATEWAY] = { .type = NLA_U32 }, 589 [RTA_PRIORITY] = { .type = NLA_U32 }, 590 [RTA_PREFSRC] = { .type = NLA_U32 }, 591 [RTA_METRICS] = { .type = NLA_NESTED }, 592 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 593 [RTA_FLOW] = { .type = NLA_U32 }, 594}; 595 596static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 597 struct nlmsghdr *nlh, struct fib_config *cfg) 598{ 599 struct nlattr *attr; 600 int err, remaining; 601 struct rtmsg *rtm; 602 603 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy); 604 if (err < 0) 605 goto errout; 606 607 memset(cfg, 0, sizeof(*cfg)); 608 609 rtm = nlmsg_data(nlh); 610 cfg->fc_dst_len = rtm->rtm_dst_len; 611 cfg->fc_tos = rtm->rtm_tos; 612 cfg->fc_table = rtm->rtm_table; 613 cfg->fc_protocol = rtm->rtm_protocol; 614 cfg->fc_scope = rtm->rtm_scope; 615 cfg->fc_type = rtm->rtm_type; 616 cfg->fc_flags = rtm->rtm_flags; 617 cfg->fc_nlflags = nlh->nlmsg_flags; 618 619 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid; 620 cfg->fc_nlinfo.nlh = nlh; 621 cfg->fc_nlinfo.nl_net = net; 622 623 if (cfg->fc_type > RTN_MAX) { 624 err = -EINVAL; 625 goto errout; 626 } 627 628 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 629 switch (nla_type(attr)) { 630 case RTA_DST: 631 cfg->fc_dst = nla_get_be32(attr); 632 break; 633 case RTA_OIF: 634 cfg->fc_oif = nla_get_u32(attr); 635 break; 636 case RTA_GATEWAY: 637 cfg->fc_gw = nla_get_be32(attr); 638 break; 639 case RTA_PRIORITY: 640 cfg->fc_priority = nla_get_u32(attr); 641 break; 642 case RTA_PREFSRC: 643 cfg->fc_prefsrc = nla_get_be32(attr); 644 break; 645 case RTA_METRICS: 646 cfg->fc_mx = nla_data(attr); 647 cfg->fc_mx_len = nla_len(attr); 648 break; 649 case RTA_MULTIPATH: 650 cfg->fc_mp = nla_data(attr); 651 cfg->fc_mp_len = nla_len(attr); 652 break; 653 case RTA_FLOW: 654 cfg->fc_flow = nla_get_u32(attr); 655 break; 656 case RTA_TABLE: 657 cfg->fc_table = nla_get_u32(attr); 658 break; 659 } 660 } 661 662 return 0; 663errout: 664 return err; 665} 666 667static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh) 668{ 669 struct net *net = sock_net(skb->sk); 670 struct fib_config cfg; 671 struct fib_table *tb; 672 int err; 673 674 err = rtm_to_fib_config(net, skb, nlh, &cfg); 675 if (err < 0) 676 goto errout; 677 678 tb = fib_get_table(net, cfg.fc_table); 679 if (!tb) { 680 err = -ESRCH; 681 goto errout; 682 } 683 684 err = fib_table_delete(tb, &cfg); 685errout: 686 return err; 687} 688 689static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh) 690{ 691 struct net *net = sock_net(skb->sk); 692 struct fib_config cfg; 693 struct fib_table *tb; 694 int err; 695 696 err = rtm_to_fib_config(net, skb, nlh, &cfg); 697 if (err < 0) 698 goto errout; 699 700 tb = fib_new_table(net, cfg.fc_table); 701 if (!tb) { 702 err = -ENOBUFS; 703 goto errout; 704 } 705 706 err = fib_table_insert(tb, &cfg); 707errout: 708 return err; 709} 710 711static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 712{ 713 struct net *net = sock_net(skb->sk); 714 unsigned int h, s_h; 715 unsigned int e = 0, s_e; 716 struct fib_table *tb; 717 struct hlist_head *head; 718 int dumped = 0; 719 720 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) && 721 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED) 722 return skb->len; 723 724 s_h = cb->args[0]; 725 s_e = cb->args[1]; 726 727 rcu_read_lock(); 728 729 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 730 e = 0; 731 head = &net->ipv4.fib_table_hash[h]; 732 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 733 if (e < s_e) 734 goto next; 735 if (dumped) 736 memset(&cb->args[2], 0, sizeof(cb->args) - 737 2 * sizeof(cb->args[0])); 738 if (fib_table_dump(tb, skb, cb) < 0) 739 goto out; 740 dumped = 1; 741next: 742 e++; 743 } 744 } 745out: 746 rcu_read_unlock(); 747 748 cb->args[1] = e; 749 cb->args[0] = h; 750 751 return skb->len; 752} 753 754/* Prepare and feed intra-kernel routing request. 755 * Really, it should be netlink message, but :-( netlink 756 * can be not configured, so that we feed it directly 757 * to fib engine. It is legal, because all events occur 758 * only when netlink is already locked. 759 */ 760static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa) 761{ 762 struct net *net = dev_net(ifa->ifa_dev->dev); 763 struct fib_table *tb; 764 struct fib_config cfg = { 765 .fc_protocol = RTPROT_KERNEL, 766 .fc_type = type, 767 .fc_dst = dst, 768 .fc_dst_len = dst_len, 769 .fc_prefsrc = ifa->ifa_local, 770 .fc_oif = ifa->ifa_dev->dev->ifindex, 771 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 772 .fc_nlinfo = { 773 .nl_net = net, 774 }, 775 }; 776 777 if (type == RTN_UNICAST) 778 tb = fib_new_table(net, RT_TABLE_MAIN); 779 else 780 tb = fib_new_table(net, RT_TABLE_LOCAL); 781 782 if (!tb) 783 return; 784 785 cfg.fc_table = tb->tb_id; 786 787 if (type != RTN_LOCAL) 788 cfg.fc_scope = RT_SCOPE_LINK; 789 else 790 cfg.fc_scope = RT_SCOPE_HOST; 791 792 if (cmd == RTM_NEWROUTE) 793 fib_table_insert(tb, &cfg); 794 else 795 fib_table_delete(tb, &cfg); 796} 797 798void fib_add_ifaddr(struct in_ifaddr *ifa) 799{ 800 struct in_device *in_dev = ifa->ifa_dev; 801 struct net_device *dev = in_dev->dev; 802 struct in_ifaddr *prim = ifa; 803 __be32 mask = ifa->ifa_mask; 804 __be32 addr = ifa->ifa_local; 805 __be32 prefix = ifa->ifa_address & mask; 806 807 if (ifa->ifa_flags & IFA_F_SECONDARY) { 808 prim = inet_ifa_byprefix(in_dev, prefix, mask); 809 if (!prim) { 810 pr_warn("%s: bug: prim == NULL\n", __func__); 811 return; 812 } 813 } 814 815 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim); 816 817 if (!(dev->flags & IFF_UP)) 818 return; 819 820 /* Add broadcast address, if it is explicitly assigned. */ 821 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 822 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 823 824 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 825 (prefix != addr || ifa->ifa_prefixlen < 32)) { 826 fib_magic(RTM_NEWROUTE, 827 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 828 prefix, ifa->ifa_prefixlen, prim); 829 830 /* Add network specific broadcasts, when it takes a sense */ 831 if (ifa->ifa_prefixlen < 31) { 832 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim); 833 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 834 32, prim); 835 } 836 } 837} 838 839/* Delete primary or secondary address. 840 * Optionally, on secondary address promotion consider the addresses 841 * from subnet iprim as deleted, even if they are in device list. 842 * In this case the secondary ifa can be in device list. 843 */ 844void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 845{ 846 struct in_device *in_dev = ifa->ifa_dev; 847 struct net_device *dev = in_dev->dev; 848 struct in_ifaddr *ifa1; 849 struct in_ifaddr *prim = ifa, *prim1 = NULL; 850 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 851 __be32 any = ifa->ifa_address & ifa->ifa_mask; 852#define LOCAL_OK 1 853#define BRD_OK 2 854#define BRD0_OK 4 855#define BRD1_OK 8 856 unsigned int ok = 0; 857 int subnet = 0; /* Primary network */ 858 int gone = 1; /* Address is missing */ 859 int same_prefsrc = 0; /* Another primary with same IP */ 860 861 if (ifa->ifa_flags & IFA_F_SECONDARY) { 862 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 863 if (!prim) { 864 pr_warn("%s: bug: prim == NULL\n", __func__); 865 return; 866 } 867 if (iprim && iprim != prim) { 868 pr_warn("%s: bug: iprim != prim\n", __func__); 869 return; 870 } 871 } else if (!ipv4_is_zeronet(any) && 872 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 873 fib_magic(RTM_DELROUTE, 874 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 875 any, ifa->ifa_prefixlen, prim); 876 subnet = 1; 877 } 878 879 /* Deletion is more complicated than add. 880 * We should take care of not to delete too much :-) 881 * 882 * Scan address list to be sure that addresses are really gone. 883 */ 884 885 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) { 886 if (ifa1 == ifa) { 887 /* promotion, keep the IP */ 888 gone = 0; 889 continue; 890 } 891 /* Ignore IFAs from our subnet */ 892 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 893 inet_ifa_match(ifa1->ifa_address, iprim)) 894 continue; 895 896 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 897 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 898 /* Another address from our subnet? */ 899 if (ifa1->ifa_mask == prim->ifa_mask && 900 inet_ifa_match(ifa1->ifa_address, prim)) 901 prim1 = prim; 902 else { 903 /* We reached the secondaries, so 904 * same_prefsrc should be determined. 905 */ 906 if (!same_prefsrc) 907 continue; 908 /* Search new prim1 if ifa1 is not 909 * using the current prim1 910 */ 911 if (!prim1 || 912 ifa1->ifa_mask != prim1->ifa_mask || 913 !inet_ifa_match(ifa1->ifa_address, prim1)) 914 prim1 = inet_ifa_byprefix(in_dev, 915 ifa1->ifa_address, 916 ifa1->ifa_mask); 917 if (!prim1) 918 continue; 919 if (prim1->ifa_local != prim->ifa_local) 920 continue; 921 } 922 } else { 923 if (prim->ifa_local != ifa1->ifa_local) 924 continue; 925 prim1 = ifa1; 926 if (prim != prim1) 927 same_prefsrc = 1; 928 } 929 if (ifa->ifa_local == ifa1->ifa_local) 930 ok |= LOCAL_OK; 931 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 932 ok |= BRD_OK; 933 if (brd == ifa1->ifa_broadcast) 934 ok |= BRD1_OK; 935 if (any == ifa1->ifa_broadcast) 936 ok |= BRD0_OK; 937 /* primary has network specific broadcasts */ 938 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 939 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 940 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 941 942 if (!ipv4_is_zeronet(any1)) { 943 if (ifa->ifa_broadcast == brd1 || 944 ifa->ifa_broadcast == any1) 945 ok |= BRD_OK; 946 if (brd == brd1 || brd == any1) 947 ok |= BRD1_OK; 948 if (any == brd1 || any == any1) 949 ok |= BRD0_OK; 950 } 951 } 952 } 953 954 if (!(ok & BRD_OK)) 955 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 956 if (subnet && ifa->ifa_prefixlen < 31) { 957 if (!(ok & BRD1_OK)) 958 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim); 959 if (!(ok & BRD0_OK)) 960 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim); 961 } 962 if (!(ok & LOCAL_OK)) { 963 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim); 964 965 /* Check, that this local address finally disappeared. */ 966 if (gone && 967 inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) { 968 /* And the last, but not the least thing. 969 * We must flush stray FIB entries. 970 * 971 * First of all, we scan fib_info list searching 972 * for stray nexthop entries, then ignite fib_flush. 973 */ 974 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local)) 975 fib_flush(dev_net(dev)); 976 } 977 } 978#undef LOCAL_OK 979#undef BRD_OK 980#undef BRD0_OK 981#undef BRD1_OK 982} 983 984static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn) 985{ 986 987 struct fib_result res; 988 struct flowi4 fl4 = { 989 .flowi4_mark = frn->fl_mark, 990 .daddr = frn->fl_addr, 991 .flowi4_tos = frn->fl_tos, 992 .flowi4_scope = frn->fl_scope, 993 }; 994 struct fib_table *tb; 995 996 rcu_read_lock(); 997 998 tb = fib_get_table(net, frn->tb_id_in); 999 1000 frn->err = -ENOENT; 1001 if (tb) { 1002 local_bh_disable(); 1003 1004 frn->tb_id = tb->tb_id; 1005 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 1006 1007 if (!frn->err) { 1008 frn->prefixlen = res.prefixlen; 1009 frn->nh_sel = res.nh_sel; 1010 frn->type = res.type; 1011 frn->scope = res.scope; 1012 } 1013 local_bh_enable(); 1014 } 1015 1016 rcu_read_unlock(); 1017} 1018 1019static void nl_fib_input(struct sk_buff *skb) 1020{ 1021 struct net *net; 1022 struct fib_result_nl *frn; 1023 struct nlmsghdr *nlh; 1024 u32 portid; 1025 1026 net = sock_net(skb->sk); 1027 nlh = nlmsg_hdr(skb); 1028 if (skb->len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len || 1029 nlmsg_len(nlh) < sizeof(*frn)) 1030 return; 1031 1032 skb = netlink_skb_clone(skb, GFP_KERNEL); 1033 if (!skb) 1034 return; 1035 nlh = nlmsg_hdr(skb); 1036 1037 frn = (struct fib_result_nl *) nlmsg_data(nlh); 1038 nl_fib_lookup(net, frn); 1039 1040 portid = NETLINK_CB(skb).portid; /* netlink portid */ 1041 NETLINK_CB(skb).portid = 0; /* from kernel */ 1042 NETLINK_CB(skb).dst_group = 0; /* unicast */ 1043 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT); 1044} 1045 1046static int __net_init nl_fib_lookup_init(struct net *net) 1047{ 1048 struct sock *sk; 1049 struct netlink_kernel_cfg cfg = { 1050 .input = nl_fib_input, 1051 }; 1052 1053 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg); 1054 if (!sk) 1055 return -EAFNOSUPPORT; 1056 net->ipv4.fibnl = sk; 1057 return 0; 1058} 1059 1060static void nl_fib_lookup_exit(struct net *net) 1061{ 1062 netlink_kernel_release(net->ipv4.fibnl); 1063 net->ipv4.fibnl = NULL; 1064} 1065 1066static void fib_disable_ip(struct net_device *dev, int force) 1067{ 1068 if (fib_sync_down_dev(dev, force)) 1069 fib_flush(dev_net(dev)); 1070 rt_cache_flush(dev_net(dev)); 1071 arp_ifdown(dev); 1072} 1073 1074static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 1075{ 1076 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 1077 struct net_device *dev = ifa->ifa_dev->dev; 1078 struct net *net = dev_net(dev); 1079 1080 switch (event) { 1081 case NETDEV_UP: 1082 fib_add_ifaddr(ifa); 1083#ifdef CONFIG_IP_ROUTE_MULTIPATH 1084 fib_sync_up(dev); 1085#endif 1086 atomic_inc(&net->ipv4.dev_addr_genid); 1087 rt_cache_flush(dev_net(dev)); 1088 break; 1089 case NETDEV_DOWN: 1090 fib_del_ifaddr(ifa, NULL); 1091 atomic_inc(&net->ipv4.dev_addr_genid); 1092 if (!ifa->ifa_dev->ifa_list) { 1093 /* Last address was deleted from this interface. 1094 * Disable IP. 1095 */ 1096 fib_disable_ip(dev, 1); 1097 } else { 1098 rt_cache_flush(dev_net(dev)); 1099 } 1100 break; 1101 } 1102 return NOTIFY_DONE; 1103} 1104 1105static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1106{ 1107 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1108 struct in_device *in_dev; 1109 struct net *net = dev_net(dev); 1110 1111 if (event == NETDEV_UNREGISTER) { 1112 fib_disable_ip(dev, 2); 1113 rt_flush_dev(dev); 1114 return NOTIFY_DONE; 1115 } 1116 1117 in_dev = __in_dev_get_rtnl(dev); 1118 if (!in_dev) 1119 return NOTIFY_DONE; 1120 1121 switch (event) { 1122 case NETDEV_UP: 1123 for_ifa(in_dev) { 1124 fib_add_ifaddr(ifa); 1125 } endfor_ifa(in_dev); 1126#ifdef CONFIG_IP_ROUTE_MULTIPATH 1127 fib_sync_up(dev); 1128#endif 1129 atomic_inc(&net->ipv4.dev_addr_genid); 1130 rt_cache_flush(net); 1131 break; 1132 case NETDEV_DOWN: 1133 fib_disable_ip(dev, 0); 1134 break; 1135 case NETDEV_CHANGEMTU: 1136 case NETDEV_CHANGE: 1137 rt_cache_flush(net); 1138 break; 1139 } 1140 return NOTIFY_DONE; 1141} 1142 1143static struct notifier_block fib_inetaddr_notifier = { 1144 .notifier_call = fib_inetaddr_event, 1145}; 1146 1147static struct notifier_block fib_netdev_notifier = { 1148 .notifier_call = fib_netdev_event, 1149}; 1150 1151static int __net_init ip_fib_net_init(struct net *net) 1152{ 1153 int err; 1154 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1155 1156 /* Avoid false sharing : Use at least a full cache line */ 1157 size = max_t(size_t, size, L1_CACHE_BYTES); 1158 1159 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1160 if (!net->ipv4.fib_table_hash) 1161 return -ENOMEM; 1162 1163 err = fib4_rules_init(net); 1164 if (err < 0) 1165 goto fail; 1166 return 0; 1167 1168fail: 1169 kfree(net->ipv4.fib_table_hash); 1170 return err; 1171} 1172 1173static void ip_fib_net_exit(struct net *net) 1174{ 1175 unsigned int i; 1176 1177 rtnl_lock(); 1178#ifdef CONFIG_IP_MULTIPLE_TABLES 1179 RCU_INIT_POINTER(net->ipv4.fib_local, NULL); 1180 RCU_INIT_POINTER(net->ipv4.fib_main, NULL); 1181 RCU_INIT_POINTER(net->ipv4.fib_default, NULL); 1182#endif 1183 for (i = 0; i < FIB_TABLE_HASHSZ; i++) { 1184 struct hlist_head *head = &net->ipv4.fib_table_hash[i]; 1185 struct hlist_node *tmp; 1186 struct fib_table *tb; 1187 1188 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) { 1189 hlist_del(&tb->tb_hlist); 1190 fib_table_flush(tb); 1191 fib_free_table(tb); 1192 } 1193 } 1194 1195#ifdef CONFIG_IP_MULTIPLE_TABLES 1196 fib4_rules_exit(net); 1197#endif 1198 rtnl_unlock(); 1199 kfree(net->ipv4.fib_table_hash); 1200} 1201 1202static int __net_init fib_net_init(struct net *net) 1203{ 1204 int error; 1205 1206#ifdef CONFIG_IP_ROUTE_CLASSID 1207 net->ipv4.fib_num_tclassid_users = 0; 1208#endif 1209 error = ip_fib_net_init(net); 1210 if (error < 0) 1211 goto out; 1212 error = nl_fib_lookup_init(net); 1213 if (error < 0) 1214 goto out_nlfl; 1215 error = fib_proc_init(net); 1216 if (error < 0) 1217 goto out_proc; 1218out: 1219 return error; 1220 1221out_proc: 1222 nl_fib_lookup_exit(net); 1223out_nlfl: 1224 ip_fib_net_exit(net); 1225 goto out; 1226} 1227 1228static void __net_exit fib_net_exit(struct net *net) 1229{ 1230 fib_proc_exit(net); 1231 nl_fib_lookup_exit(net); 1232 ip_fib_net_exit(net); 1233} 1234 1235static struct pernet_operations fib_net_ops = { 1236 .init = fib_net_init, 1237 .exit = fib_net_exit, 1238}; 1239 1240void __init ip_fib_init(void) 1241{ 1242 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL); 1243 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL); 1244 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL); 1245 1246 register_pernet_subsys(&fib_net_ops); 1247 register_netdevice_notifier(&fib_netdev_notifier); 1248 register_inetaddr_notifier(&fib_inetaddr_notifier); 1249 1250 fib_trie_init(); 1251} 1252