net/ipv4/fib_frontend.c

   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 #include <net/l3mdev.h>
  49 #include <trace/events/fib.h>
  50
  51 #ifndef CONFIG_IP_MULTIPLE_TABLES
  52
  53 static int __net_init fib4_rules_init(struct net *net)
  54 {
  55         struct fib_table *local_table, *main_table;
  56
  57         main_table  = fib_trie_table(RT_TABLE_MAIN, NULL);
  58         if (!main_table)
  59                 return -ENOMEM;
  60
  61         local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
  62         if (!local_table)
  63                 goto fail;
  64
  65         hlist_add_head_rcu(&local_table->tb_hlist,
  66                                 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
  67         hlist_add_head_rcu(&main_table->tb_hlist,
  68                                 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
  69         return 0;
  70
  71 fail:
  72         fib_free_table(main_table);
  73         return -ENOMEM;
  74 }
  75 #else
  76
  77 struct fib_table *fib_new_table(struct net *net, u32 id)
  78 {
  79         struct fib_table *tb, *alias = NULL;
  80         unsigned int h;
  81
  82         if (id == 0)
  83                 id = RT_TABLE_MAIN;
  84         tb = fib_get_table(net, id);
  85         if (tb)
  86                 return tb;
  87
  88         if (id == RT_TABLE_LOCAL)
  89                 alias = fib_new_table(net, RT_TABLE_MAIN);
  90
  91         tb = fib_trie_table(id, alias);
  92         if (!tb)
  93                 return NULL;
  94
  95         switch (id) {
  96         case RT_TABLE_LOCAL:
  97                 rcu_assign_pointer(net->ipv4.fib_local, tb);
  98                 break;
  99         case RT_TABLE_MAIN:
 100                 rcu_assign_pointer(net->ipv4.fib_main, tb);
 101                 break;
 102         case RT_TABLE_DEFAULT:
 103                 rcu_assign_pointer(net->ipv4.fib_default, tb);
 104                 break;
 105         default:
 106                 break;
 107         }
 108
 109         h = id & (FIB_TABLE_HASHSZ - 1);
 110         hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
 111         return tb;
 112 }
 113 EXPORT_SYMBOL_GPL(fib_new_table);
 114
 115 /* caller must hold either rtnl or rcu read lock */
 116 struct fib_table *fib_get_table(struct net *net, u32 id)
 117 {
 118         struct fib_table *tb;
 119         struct hlist_head *head;
 120         unsigned int h;
 121
 122         if (id == 0)
 123                 id = RT_TABLE_MAIN;
 124         h = id & (FIB_TABLE_HASHSZ - 1);
 125
 126         head = &net->ipv4.fib_table_hash[h];
 127         hlist_for_each_entry_rcu(tb, head, tb_hlist) {
 128                 if (tb->tb_id == id)
 129                         return tb;
 130         }
 131         return NULL;
 132 }
 133 #endif /* CONFIG_IP_MULTIPLE_TABLES */
 134
 135 static void fib_replace_table(struct net *net, struct fib_table *old,
 136                               struct fib_table *new)
 137 {
 138 #ifdef CONFIG_IP_MULTIPLE_TABLES
 139         switch (new->tb_id) {
 140         case RT_TABLE_LOCAL:
 141                 rcu_assign_pointer(net->ipv4.fib_local, new);
 142                 break;
 143         case RT_TABLE_MAIN:
 144                 rcu_assign_pointer(net->ipv4.fib_main, new);
 145                 break;
 146         case RT_TABLE_DEFAULT:
 147                 rcu_assign_pointer(net->ipv4.fib_default, new);
 148                 break;
 149         default:
 150                 break;
 151         }
 152
 153 #endif
 154         /* replace the old table in the hlist */
 155         hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
 156 }
 157
 158 int fib_unmerge(struct net *net)
 159 {
 160         struct fib_table *old, *new;
 161
 162         /* attempt to fetch local table if it has been allocated */
 163         old = fib_get_table(net, RT_TABLE_LOCAL);
 164         if (!old)
 165                 return 0;
 166
 167         new = fib_trie_unmerge(old);
 168         if (!new)
 169                 return -ENOMEM;
 170
 171         /* replace merged table with clean table */
 172         if (new != old) {
 173                 fib_replace_table(net, old, new);
 174                 fib_free_table(old);
 175         }
 176
 177         return 0;
 178 }
 179
 180 static void fib_flush(struct net *net)
 181 {
 182         int flushed = 0;
 183         unsigned int h;
 184
 185         for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
 186                 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
 187                 struct hlist_node *tmp;
 188                 struct fib_table *tb;
 189
 190                 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
 191                         flushed += fib_table_flush(tb);
 192         }
 193
 194         if (flushed)
 195                 rt_cache_flush(net);
 196 }
 197
 198 void fib_flush_external(struct net *net)
 199 {
 200         struct fib_table *tb;
 201         struct hlist_head *head;
 202         unsigned int h;
 203
 204         for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
 205                 head = &net->ipv4.fib_table_hash[h];
 206                 hlist_for_each_entry(tb, head, tb_hlist)
 207                         fib_table_flush_external(tb);
 208         }
 209 }
 210
 211 /*
 212  * Find address type as if only "dev" was present in the system. If
 213  * on_dev is NULL then all interfaces are taken into consideration.
 214  */
 215 static inline unsigned int __inet_dev_addr_type(struct net *net,
 216                                                 const struct net_device *dev,
 217                                                 __be32 addr, u32 tb_id)
 218 {
 219         struct flowi4           fl4 = { .daddr = addr };
 220         struct fib_result       res;
 221         unsigned int ret = RTN_BROADCAST;
 222         struct fib_table *table;
 223
 224         if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
 225                 return RTN_BROADCAST;
 226         if (ipv4_is_multicast(addr))
 227                 return RTN_MULTICAST;
 228
 229         rcu_read_lock();
 230
 231         table = fib_get_table(net, tb_id);
 232         if (table) {
 233                 ret = RTN_UNICAST;
 234                 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
 235                         if (!dev || dev == res.fi->fib_dev)
 236                                 ret = res.type;
 237                 }
 238         }
 239
 240         rcu_read_unlock();
 241         return ret;
 242 }
 243
 244 unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
 245 {
 246         return __inet_dev_addr_type(net, NULL, addr, tb_id);
 247 }
 248 EXPORT_SYMBOL(inet_addr_type_table);
 249
 250 unsigned int inet_addr_type(struct net *net, __be32 addr)
 251 {
 252         return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
 253 }
 254 EXPORT_SYMBOL(inet_addr_type);
 255
 256 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
 257                                 __be32 addr)
 258 {
 259         u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
 260
 261         return __inet_dev_addr_type(net, dev, addr, rt_table);
 262 }
 263 EXPORT_SYMBOL(inet_dev_addr_type);
 264
 265 /* inet_addr_type with dev == NULL but using the table from a dev
 266  * if one is associated
 267  */
 268 unsigned int inet_addr_type_dev_table(struct net *net,
 269                                       const struct net_device *dev,
 270                                       __be32 addr)
 271 {
 272         u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
 273
 274         return __inet_dev_addr_type(net, NULL, addr, rt_table);
 275 }
 276 EXPORT_SYMBOL(inet_addr_type_dev_table);
 277
 278 __be32 fib_compute_spec_dst(struct sk_buff *skb)
 279 {
 280         struct net_device *dev = skb->dev;
 281         struct in_device *in_dev;
 282         struct fib_result res;
 283         struct rtable *rt;
 284         struct net *net;
 285         int scope;
 286
 287         rt = skb_rtable(skb);
 288         if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
 289             RTCF_LOCAL)
 290                 return ip_hdr(skb)->daddr;
 291
 292         in_dev = __in_dev_get_rcu(dev);
 293         BUG_ON(!in_dev);
 294
 295         net = dev_net(dev);
 296
 297         scope = RT_SCOPE_UNIVERSE;
 298         if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
 299                 struct flowi4 fl4 = {
 300                         .flowi4_iif = LOOPBACK_IFINDEX,
 301                         .daddr = ip_hdr(skb)->saddr,
 302                         .flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
 303                         .flowi4_scope = scope,
 304                         .flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0,
 305                 };
 306                 if (!fib_lookup(net, &fl4, &res, 0))
 307                         return FIB_RES_PREFSRC(net, res);
 308         } else {
 309                 scope = RT_SCOPE_LINK;
 310         }
 311
 312         return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
 313 }
 314
 315 /* Given (packet source, input interface) and optional (dst, oif, tos):
 316  * - (main) check, that source is valid i.e. not broadcast or our local
 317  *   address.
 318  * - figure out what "logical" interface this packet arrived
 319  *   and calculate "specific destination" address.
 320  * - check, that packet arrived from expected physical interface.
 321  * called with rcu_read_lock()
 322  */
 323 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 324                                  u8 tos, int oif, struct net_device *dev,
 325                                  int rpf, struct in_device *idev, u32 *itag)
 326 {
 327         int ret, no_addr;
 328         struct fib_result res;
 329         struct flowi4 fl4;
 330         struct net *net;
 331         bool dev_match;
 332
 333         fl4.flowi4_oif = 0;
 334         fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
 335         if (!fl4.flowi4_iif)
 336                 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
 337         fl4.daddr = src;
 338         fl4.saddr = dst;
 339         fl4.flowi4_tos = tos;
 340         fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
 341         fl4.flowi4_tun_key.tun_id = 0;
 342         fl4.flowi4_flags = 0;
 343
 344         no_addr = idev->ifa_list == NULL;
 345
 346         fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
 347
 348         trace_fib_validate_source(dev, &fl4);
 349
 350         net = dev_net(dev);
 351         if (fib_lookup(net, &fl4, &res, 0))
 352                 goto last_resort;
 353         if (res.type != RTN_UNICAST &&
 354             (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
 355                 goto e_inval;
 356         if (!rpf && !fib_num_tclassid_users(dev_net(dev)) &&
 357             (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev)))
 358                 goto last_resort;
 359         fib_combine_itag(itag, &res);
 360         dev_match = false;
 361
 362 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 363         for (ret = 0; ret < res.fi->fib_nhs; ret++) {
 364                 struct fib_nh *nh = &res.fi->fib_nh[ret];
 365
 366                 if (nh->nh_dev == dev) {
 367                         dev_match = true;
 368                         break;
 369                 } else if (l3mdev_master_ifindex_rcu(nh->nh_dev) == dev->ifindex) {
 370                         dev_match = true;
 371                         break;
 372                 }
 373         }
 374 #else
 375         if (FIB_RES_DEV(res) == dev)
 376                 dev_match = true;
 377 #endif
 378         if (dev_match) {
 379                 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
 380                 return ret;
 381         }
 382         if (no_addr)
 383                 goto last_resort;
 384         if (rpf == 1)
 385                 goto e_rpf;
 386         fl4.flowi4_oif = dev->ifindex;
 387
 388         ret = 0;
 389         if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
 390                 if (res.type == RTN_UNICAST)
 391                         ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
 392         }
 393         return ret;
 394
 395 last_resort:
 396         if (rpf)
 397                 goto e_rpf;
 398         *itag = 0;
 399         return 0;
 400
 401 e_inval:
 402         return -EINVAL;
 403 e_rpf:
 404         return -EXDEV;
 405 }
 406
 407 /* Ignore rp_filter for packets protected by IPsec. */
 408 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 409                         u8 tos, int oif, struct net_device *dev,
 410                         struct in_device *idev, u32 *itag)
 411 {
 412         int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
 413
 414         if (!r && !fib_num_tclassid_users(dev_net(dev)) &&
 415             IN_DEV_ACCEPT_LOCAL(idev) &&
 416             (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
 417                 *itag = 0;
 418                 return 0;
 419         }
 420         return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
 421 }
 422
 423 static inline __be32 sk_extract_addr(struct sockaddr *addr)
 424 {
 425         return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
 426 }
 427
 428 static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
 429 {
 430         struct nlattr *nla;
 431
 432         nla = (struct nlattr *) ((char *) mx + len);
 433         nla->nla_type = type;
 434         nla->nla_len = nla_attr_size(4);
 435         *(u32 *) nla_data(nla) = value;
 436
 437         return len + nla_total_size(4);
 438 }
 439
 440 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
 441                                  struct fib_config *cfg)
 442 {
 443         __be32 addr;
 444         int plen;
 445
 446         memset(cfg, 0, sizeof(*cfg));
 447         cfg->fc_nlinfo.nl_net = net;
 448
 449         if (rt->rt_dst.sa_family != AF_INET)
 450                 return -EAFNOSUPPORT;
 451
 452         /*
 453          * Check mask for validity:
 454          * a) it must be contiguous.
 455          * b) destination must have all host bits clear.
 456          * c) if application forgot to set correct family (AF_INET),
 457          *    reject request unless it is absolutely clear i.e.
 458          *    both family and mask are zero.
 459          */
 460         plen = 32;
 461         addr = sk_extract_addr(&rt->rt_dst);
 462         if (!(rt->rt_flags & RTF_HOST)) {
 463                 __be32 mask = sk_extract_addr(&rt->rt_genmask);
 464
 465                 if (rt->rt_genmask.sa_family != AF_INET) {
 466                         if (mask || rt->rt_genmask.sa_family)
 467                                 return -EAFNOSUPPORT;
 468                 }
 469
 470                 if (bad_mask(mask, addr))
 471                         return -EINVAL;
 472
 473                 plen = inet_mask_len(mask);
 474         }
 475
 476         cfg->fc_dst_len = plen;
 477         cfg->fc_dst = addr;
 478
 479         if (cmd != SIOCDELRT) {
 480                 cfg->fc_nlflags = NLM_F_CREATE;
 481                 cfg->fc_protocol = RTPROT_BOOT;
 482         }
 483
 484         if (rt->rt_metric)
 485                 cfg->fc_priority = rt->rt_metric - 1;
 486
 487         if (rt->rt_flags & RTF_REJECT) {
 488                 cfg->fc_scope = RT_SCOPE_HOST;
 489                 cfg->fc_type = RTN_UNREACHABLE;
 490                 return 0;
 491         }
 492
 493         cfg->fc_scope = RT_SCOPE_NOWHERE;
 494         cfg->fc_type = RTN_UNICAST;
 495
 496         if (rt->rt_dev) {
 497                 char *colon;
 498                 struct net_device *dev;
 499                 char devname[IFNAMSIZ];
 500
 501                 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
 502                         return -EFAULT;
 503
 504                 devname[IFNAMSIZ-1] = 0;
 505                 colon = strchr(devname, ':');
 506                 if (colon)
 507                         *colon = 0;
 508                 dev = __dev_get_by_name(net, devname);
 509                 if (!dev)
 510                         return -ENODEV;
 511                 cfg->fc_oif = dev->ifindex;
 512                 cfg->fc_table = l3mdev_fib_table(dev);
 513                 if (colon) {
 514                         struct in_ifaddr *ifa;
 515                         struct in_device *in_dev = __in_dev_get_rtnl(dev);
 516                         if (!in_dev)
 517                                 return -ENODEV;
 518                         *colon = ':';
 519                         for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
 520                                 if (strcmp(ifa->ifa_label, devname) == 0)
 521                                         break;
 522                         if (!ifa)
 523                                 return -ENODEV;
 524                         cfg->fc_prefsrc = ifa->ifa_local;
 525                 }
 526         }
 527
 528         addr = sk_extract_addr(&rt->rt_gateway);
 529         if (rt->rt_gateway.sa_family == AF_INET && addr) {
 530                 unsigned int addr_type;
 531
 532                 cfg->fc_gw = addr;
 533                 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
 534                 if (rt->rt_flags & RTF_GATEWAY &&
 535                     addr_type == RTN_UNICAST)
 536                         cfg->fc_scope = RT_SCOPE_UNIVERSE;
 537         }
 538
 539         if (cmd == SIOCDELRT)
 540                 return 0;
 541
 542         if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
 543                 return -EINVAL;
 544
 545         if (cfg->fc_scope == RT_SCOPE_NOWHERE)
 546                 cfg->fc_scope = RT_SCOPE_LINK;
 547
 548         if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
 549                 struct nlattr *mx;
 550                 int len = 0;
 551
 552                 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
 553                 if (!mx)
 554                         return -ENOMEM;
 555
 556                 if (rt->rt_flags & RTF_MTU)
 557                         len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
 558
 559                 if (rt->rt_flags & RTF_WINDOW)
 560                         len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
 561
 562                 if (rt->rt_flags & RTF_IRTT)
 563                         len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
 564
 565                 cfg->fc_mx = mx;
 566                 cfg->fc_mx_len = len;
 567         }
 568
 569         return 0;
 570 }
 571
 572 /*
 573  * Handle IP routing ioctl calls.
 574  * These are used to manipulate the routing tables
 575  */
 576 int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 577 {
 578         struct fib_config cfg;
 579         struct rtentry rt;
 580         int err;
 581
 582         switch (cmd) {
 583         case SIOCADDRT:         /* Add a route */
 584         case SIOCDELRT:         /* Delete a route */
 585                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 586                         return -EPERM;
 587
 588                 if (copy_from_user(&rt, arg, sizeof(rt)))
 589                         return -EFAULT;
 590
 591                 rtnl_lock();
 592                 err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
 593                 if (err == 0) {
 594                         struct fib_table *tb;
 595
 596                         if (cmd == SIOCDELRT) {
 597                                 tb = fib_get_table(net, cfg.fc_table);
 598                                 if (tb)
 599                                         err = fib_table_delete(tb, &cfg);
 600                                 else
 601                                         err = -ESRCH;
 602                         } else {
 603                                 tb = fib_new_table(net, cfg.fc_table);
 604                                 if (tb)
 605                                         err = fib_table_insert(tb, &cfg);
 606                                 else
 607                                         err = -ENOBUFS;
 608                         }
 609
 610                         /* allocated by rtentry_to_fib_config() */
 611                         kfree(cfg.fc_mx);
 612                 }
 613                 rtnl_unlock();
 614                 return err;
 615         }
 616         return -EINVAL;
 617 }
 618
 619 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
 620         [RTA_DST]               = { .type = NLA_U32 },
 621         [RTA_SRC]               = { .type = NLA_U32 },
 622         [RTA_IIF]               = { .type = NLA_U32 },
 623         [RTA_OIF]               = { .type = NLA_U32 },
 624         [RTA_GATEWAY]           = { .type = NLA_U32 },
 625         [RTA_PRIORITY]          = { .type = NLA_U32 },
 626         [RTA_PREFSRC]           = { .type = NLA_U32 },
 627         [RTA_METRICS]           = { .type = NLA_NESTED },
 628         [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
 629         [RTA_FLOW]              = { .type = NLA_U32 },
 630         [RTA_ENCAP_TYPE]        = { .type = NLA_U16 },
 631         [RTA_ENCAP]             = { .type = NLA_NESTED },
 632 };
 633
 634 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
 635                              struct nlmsghdr *nlh, struct fib_config *cfg)
 636 {
 637         struct nlattr *attr;
 638         int err, remaining;
 639         struct rtmsg *rtm;
 640
 641         err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
 642         if (err < 0)
 643                 goto errout;
 644
 645         memset(cfg, 0, sizeof(*cfg));
 646
 647         rtm = nlmsg_data(nlh);
 648         cfg->fc_dst_len = rtm->rtm_dst_len;
 649         cfg->fc_tos = rtm->rtm_tos;
 650         cfg->fc_table = rtm->rtm_table;
 651         cfg->fc_protocol = rtm->rtm_protocol;
 652         cfg->fc_scope = rtm->rtm_scope;
 653         cfg->fc_type = rtm->rtm_type;
 654         cfg->fc_flags = rtm->rtm_flags;
 655         cfg->fc_nlflags = nlh->nlmsg_flags;
 656
 657         cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
 658         cfg->fc_nlinfo.nlh = nlh;
 659         cfg->fc_nlinfo.nl_net = net;
 660
 661         if (cfg->fc_type > RTN_MAX) {
 662                 err = -EINVAL;
 663                 goto errout;
 664         }
 665
 666         nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
 667                 switch (nla_type(attr)) {
 668                 case RTA_DST:
 669                         cfg->fc_dst = nla_get_be32(attr);
 670                         break;
 671                 case RTA_OIF:
 672                         cfg->fc_oif = nla_get_u32(attr);
 673                         break;
 674                 case RTA_GATEWAY:
 675                         cfg->fc_gw = nla_get_be32(attr);
 676                         break;
 677                 case RTA_PRIORITY:
 678                         cfg->fc_priority = nla_get_u32(attr);
 679                         break;
 680                 case RTA_PREFSRC:
 681                         cfg->fc_prefsrc = nla_get_be32(attr);
 682                         break;
 683                 case RTA_METRICS:
 684                         cfg->fc_mx = nla_data(attr);
 685                         cfg->fc_mx_len = nla_len(attr);
 686                         break;
 687                 case RTA_MULTIPATH:
 688                         cfg->fc_mp = nla_data(attr);
 689                         cfg->fc_mp_len = nla_len(attr);
 690                         break;
 691                 case RTA_FLOW:
 692                         cfg->fc_flow = nla_get_u32(attr);
 693                         break;
 694                 case RTA_TABLE:
 695                         cfg->fc_table = nla_get_u32(attr);
 696                         break;
 697                 case RTA_ENCAP:
 698                         cfg->fc_encap = attr;
 699                         break;
 700                 case RTA_ENCAP_TYPE:
 701                         cfg->fc_encap_type = nla_get_u16(attr);
 702                         break;
 703                 }
 704         }
 705
 706         return 0;
 707 errout:
 708         return err;
 709 }
 710
 711 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
 712 {
 713         struct net *net = sock_net(skb->sk);
 714         struct fib_config cfg;
 715         struct fib_table *tb;
 716         int err;
 717
 718         err = rtm_to_fib_config(net, skb, nlh, &cfg);
 719         if (err < 0)
 720                 goto errout;
 721
 722         tb = fib_get_table(net, cfg.fc_table);
 723         if (!tb) {
 724                 err = -ESRCH;
 725                 goto errout;
 726         }
 727
 728         err = fib_table_delete(tb, &cfg);
 729 errout:
 730         return err;
 731 }
 732
 733 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
 734 {
 735         struct net *net = sock_net(skb->sk);
 736         struct fib_config cfg;
 737         struct fib_table *tb;
 738         int err;
 739
 740         err = rtm_to_fib_config(net, skb, nlh, &cfg);
 741         if (err < 0)
 742                 goto errout;
 743
 744         tb = fib_new_table(net, cfg.fc_table);
 745         if (!tb) {
 746                 err = -ENOBUFS;
 747                 goto errout;
 748         }
 749
 750         err = fib_table_insert(tb, &cfg);
 751 errout:
 752         return err;
 753 }
 754
 755 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 756 {
 757         struct net *net = sock_net(skb->sk);
 758         unsigned int h, s_h;
 759         unsigned int e = 0, s_e;
 760         struct fib_table *tb;
 761         struct hlist_head *head;
 762         int dumped = 0;
 763
 764         if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
 765             ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
 766                 return skb->len;
 767
 768         s_h = cb->args[0];
 769         s_e = cb->args[1];
 770
 771         rcu_read_lock();
 772
 773         for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
 774                 e = 0;
 775                 head = &net->ipv4.fib_table_hash[h];
 776                 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
 777                         if (e < s_e)
 778                                 goto next;
 779                         if (dumped)
 780                                 memset(&cb->args[2], 0, sizeof(cb->args) -
 781                                                  2 * sizeof(cb->args[0]));
 782                         if (fib_table_dump(tb, skb, cb) < 0)
 783                                 goto out;
 784                         dumped = 1;
 785 next:
 786                         e++;
 787                 }
 788         }
 789 out:
 790         rcu_read_unlock();
 791
 792         cb->args[1] = e;
 793         cb->args[0] = h;
 794
 795         return skb->len;
 796 }
 797
 798 /* Prepare and feed intra-kernel routing request.
 799  * Really, it should be netlink message, but :-( netlink
 800  * can be not configured, so that we feed it directly
 801  * to fib engine. It is legal, because all events occur
 802  * only when netlink is already locked.
 803  */
 804 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
 805 {
 806         struct net *net = dev_net(ifa->ifa_dev->dev);
 807         u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
 808         struct fib_table *tb;
 809         struct fib_config cfg = {
 810                 .fc_protocol = RTPROT_KERNEL,
 811                 .fc_type = type,
 812                 .fc_dst = dst,
 813                 .fc_dst_len = dst_len,
 814                 .fc_prefsrc = ifa->ifa_local,
 815                 .fc_oif = ifa->ifa_dev->dev->ifindex,
 816                 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
 817                 .fc_nlinfo = {
 818                         .nl_net = net,
 819                 },
 820         };
 821
 822         if (!tb_id)
 823                 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
 824
 825         tb = fib_new_table(net, tb_id);
 826         if (!tb)
 827                 return;
 828
 829         cfg.fc_table = tb->tb_id;
 830
 831         if (type != RTN_LOCAL)
 832                 cfg.fc_scope = RT_SCOPE_LINK;
 833         else
 834                 cfg.fc_scope = RT_SCOPE_HOST;
 835
 836         if (cmd == RTM_NEWROUTE)
 837                 fib_table_insert(tb, &cfg);
 838         else
 839                 fib_table_delete(tb, &cfg);
 840 }
 841
 842 void fib_add_ifaddr(struct in_ifaddr *ifa)
 843 {
 844         struct in_device *in_dev = ifa->ifa_dev;
 845         struct net_device *dev = in_dev->dev;
 846         struct in_ifaddr *prim = ifa;
 847         __be32 mask = ifa->ifa_mask;
 848         __be32 addr = ifa->ifa_local;
 849         __be32 prefix = ifa->ifa_address & mask;
 850
 851         if (ifa->ifa_flags & IFA_F_SECONDARY) {
 852                 prim = inet_ifa_byprefix(in_dev, prefix, mask);
 853                 if (!prim) {
 854                         pr_warn("%s: bug: prim == NULL\n", __func__);
 855                         return;
 856                 }
 857         }
 858
 859         fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
 860
 861         if (!(dev->flags & IFF_UP))
 862                 return;
 863
 864         /* Add broadcast address, if it is explicitly assigned. */
 865         if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
 866                 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
 867
 868         if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
 869             (prefix != addr || ifa->ifa_prefixlen < 32)) {
 870                 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
 871                         fib_magic(RTM_NEWROUTE,
 872                                   dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
 873                                   prefix, ifa->ifa_prefixlen, prim);
 874
 875                 /* Add network specific broadcasts, when it takes a sense */
 876                 if (ifa->ifa_prefixlen < 31) {
 877                         fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
 878                         fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
 879                                   32, prim);
 880                 }
 881         }
 882 }
 883
 884 /* Delete primary or secondary address.
 885  * Optionally, on secondary address promotion consider the addresses
 886  * from subnet iprim as deleted, even if they are in device list.
 887  * In this case the secondary ifa can be in device list.
 888  */
 889 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
 890 {
 891         struct in_device *in_dev = ifa->ifa_dev;
 892         struct net_device *dev = in_dev->dev;
 893         struct in_ifaddr *ifa1;
 894         struct in_ifaddr *prim = ifa, *prim1 = NULL;
 895         __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
 896         __be32 any = ifa->ifa_address & ifa->ifa_mask;
 897 #define LOCAL_OK        1
 898 #define BRD_OK          2
 899 #define BRD0_OK         4
 900 #define BRD1_OK         8
 901         unsigned int ok = 0;
 902         int subnet = 0;         /* Primary network */
 903         int gone = 1;           /* Address is missing */
 904         int same_prefsrc = 0;   /* Another primary with same IP */
 905
 906         if (ifa->ifa_flags & IFA_F_SECONDARY) {
 907                 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
 908                 if (!prim) {
 909                         /* if the device has been deleted, we don't perform
 910                          * address promotion
 911                          */
 912                         if (!in_dev->dead)
 913                                 pr_warn("%s: bug: prim == NULL\n", __func__);
 914                         return;
 915                 }
 916                 if (iprim && iprim != prim) {
 917                         pr_warn("%s: bug: iprim != prim\n", __func__);
 918                         return;
 919                 }
 920         } else if (!ipv4_is_zeronet(any) &&
 921                    (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
 922                 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
 923                         fib_magic(RTM_DELROUTE,
 924                                   dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
 925                                   any, ifa->ifa_prefixlen, prim);
 926                 subnet = 1;
 927         }
 928
 929         if (in_dev->dead)
 930                 goto no_promotions;
 931
 932         /* Deletion is more complicated than add.
 933          * We should take care of not to delete too much :-)
 934          *
 935          * Scan address list to be sure that addresses are really gone.
 936          */
 937
 938         for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
 939                 if (ifa1 == ifa) {
 940                         /* promotion, keep the IP */
 941                         gone = 0;
 942                         continue;
 943                 }
 944                 /* Ignore IFAs from our subnet */
 945                 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
 946                     inet_ifa_match(ifa1->ifa_address, iprim))
 947                         continue;
 948
 949                 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
 950                 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
 951                         /* Another address from our subnet? */
 952                         if (ifa1->ifa_mask == prim->ifa_mask &&
 953                             inet_ifa_match(ifa1->ifa_address, prim))
 954                                 prim1 = prim;
 955                         else {
 956                                 /* We reached the secondaries, so
 957                                  * same_prefsrc should be determined.
 958                                  */
 959                                 if (!same_prefsrc)
 960                                         continue;
 961                                 /* Search new prim1 if ifa1 is not
 962                                  * using the current prim1
 963                                  */
 964                                 if (!prim1 ||
 965                                     ifa1->ifa_mask != prim1->ifa_mask ||
 966                                     !inet_ifa_match(ifa1->ifa_address, prim1))
 967                                         prim1 = inet_ifa_byprefix(in_dev,
 968                                                         ifa1->ifa_address,
 969                                                         ifa1->ifa_mask);
 970                                 if (!prim1)
 971                                         continue;
 972                                 if (prim1->ifa_local != prim->ifa_local)
 973                                         continue;
 974                         }
 975                 } else {
 976                         if (prim->ifa_local != ifa1->ifa_local)
 977                                 continue;
 978                         prim1 = ifa1;
 979                         if (prim != prim1)
 980                                 same_prefsrc = 1;
 981                 }
 982                 if (ifa->ifa_local == ifa1->ifa_local)
 983                         ok |= LOCAL_OK;
 984                 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
 985                         ok |= BRD_OK;
 986                 if (brd == ifa1->ifa_broadcast)
 987                         ok |= BRD1_OK;
 988                 if (any == ifa1->ifa_broadcast)
 989                         ok |= BRD0_OK;
 990                 /* primary has network specific broadcasts */
 991                 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
 992                         __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
 993                         __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
 994
 995                         if (!ipv4_is_zeronet(any1)) {
 996                                 if (ifa->ifa_broadcast == brd1 ||
 997                                     ifa->ifa_broadcast == any1)
 998                                         ok |= BRD_OK;
 999                                 if (brd == brd1 || brd == any1)
1000                                         ok |= BRD1_OK;
1001                                 if (any == brd1 || any == any1)
1002                                         ok |= BRD0_OK;
1003                         }
1004                 }
1005         }
1006
1007 no_promotions:
1008         if (!(ok & BRD_OK))
1009                 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
1010         if (subnet && ifa->ifa_prefixlen < 31) {
1011                 if (!(ok & BRD1_OK))
1012                         fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
1013                 if (!(ok & BRD0_OK))
1014                         fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
1015         }
1016         if (!(ok & LOCAL_OK)) {
1017                 unsigned int addr_type;
1018
1019                 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
1020
1021                 /* Check, that this local address finally disappeared. */
1022                 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1023                                                      ifa->ifa_local);
1024                 if (gone && addr_type != RTN_LOCAL) {
1025                         /* And the last, but not the least thing.
1026                          * We must flush stray FIB entries.
1027                          *
1028                          * First of all, we scan fib_info list searching
1029                          * for stray nexthop entries, then ignite fib_flush.
1030                          */
1031                         if (fib_sync_down_addr(dev, ifa->ifa_local))
1032                                 fib_flush(dev_net(dev));
1033                 }
1034         }
1035 #undef LOCAL_OK
1036 #undef BRD_OK
1037 #undef BRD0_OK
1038 #undef BRD1_OK
1039 }
1040
1041 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1042 {
1043
1044         struct fib_result       res;
1045         struct flowi4           fl4 = {
1046                 .flowi4_mark = frn->fl_mark,
1047                 .daddr = frn->fl_addr,
1048                 .flowi4_tos = frn->fl_tos,
1049                 .flowi4_scope = frn->fl_scope,
1050         };
1051         struct fib_table *tb;
1052
1053         rcu_read_lock();
1054
1055         tb = fib_get_table(net, frn->tb_id_in);
1056
1057         frn->err = -ENOENT;
1058         if (tb) {
1059                 local_bh_disable();
1060
1061                 frn->tb_id = tb->tb_id;
1062                 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1063
1064                 if (!frn->err) {
1065                         frn->prefixlen = res.prefixlen;
1066                         frn->nh_sel = res.nh_sel;
1067                         frn->type = res.type;
1068                         frn->scope = res.scope;
1069                 }
1070                 local_bh_enable();
1071         }
1072
1073         rcu_read_unlock();
1074 }
1075
1076 static void nl_fib_input(struct sk_buff *skb)
1077 {
1078         struct net *net;
1079         struct fib_result_nl *frn;
1080         struct nlmsghdr *nlh;
1081         u32 portid;
1082
1083         net = sock_net(skb->sk);
1084         nlh = nlmsg_hdr(skb);
1085         if (skb->len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len ||
1086             nlmsg_len(nlh) < sizeof(*frn))
1087                 return;
1088
1089         skb = netlink_skb_clone(skb, GFP_KERNEL);
1090         if (!skb)
1091                 return;
1092         nlh = nlmsg_hdr(skb);
1093
1094         frn = (struct fib_result_nl *) nlmsg_data(nlh);
1095         nl_fib_lookup(net, frn);
1096
1097         portid = NETLINK_CB(skb).portid;      /* netlink portid */
1098         NETLINK_CB(skb).portid = 0;        /* from kernel */
1099         NETLINK_CB(skb).dst_group = 0;  /* unicast */
1100         netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1101 }
1102
1103 static int __net_init nl_fib_lookup_init(struct net *net)
1104 {
1105         struct sock *sk;
1106         struct netlink_kernel_cfg cfg = {
1107                 .input  = nl_fib_input,
1108         };
1109
1110         sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1111         if (!sk)
1112                 return -EAFNOSUPPORT;
1113         net->ipv4.fibnl = sk;
1114         return 0;
1115 }
1116
1117 static void nl_fib_lookup_exit(struct net *net)
1118 {
1119         netlink_kernel_release(net->ipv4.fibnl);
1120         net->ipv4.fibnl = NULL;
1121 }
1122
1123 static void fib_disable_ip(struct net_device *dev, unsigned long event,
1124                            bool force)
1125 {
1126         if (fib_sync_down_dev(dev, event, force))
1127                 fib_flush(dev_net(dev));
1128         rt_cache_flush(dev_net(dev));
1129         arp_ifdown(dev);
1130 }
1131
1132 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1133 {
1134         struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1135         struct net_device *dev = ifa->ifa_dev->dev;
1136         struct net *net = dev_net(dev);
1137
1138         switch (event) {
1139         case NETDEV_UP:
1140                 fib_add_ifaddr(ifa);
1141 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1142                 fib_sync_up(dev, RTNH_F_DEAD);
1143 #endif
1144                 atomic_inc(&net->ipv4.dev_addr_genid);
1145                 rt_cache_flush(dev_net(dev));
1146                 break;
1147         case NETDEV_DOWN:
1148                 fib_del_ifaddr(ifa, NULL);
1149                 atomic_inc(&net->ipv4.dev_addr_genid);
1150                 if (!ifa->ifa_dev->ifa_list) {
1151                         /* Last address was deleted from this interface.
1152                          * Disable IP.
1153                          */
1154                         fib_disable_ip(dev, event, true);
1155                 } else {
1156                         rt_cache_flush(dev_net(dev));
1157                 }
1158                 break;
1159         }
1160         return NOTIFY_DONE;
1161 }
1162
1163 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1164 {
1165         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1166         struct netdev_notifier_changeupper_info *info;
1167         struct in_device *in_dev;
1168         struct net *net = dev_net(dev);
1169         unsigned int flags;
1170
1171         if (event == NETDEV_UNREGISTER) {
1172                 fib_disable_ip(dev, event, true);
1173                 rt_flush_dev(dev);
1174                 return NOTIFY_DONE;
1175         }
1176
1177         in_dev = __in_dev_get_rtnl(dev);
1178         if (!in_dev)
1179                 return NOTIFY_DONE;
1180
1181         switch (event) {
1182         case NETDEV_UP:
1183                 for_ifa(in_dev) {
1184                         fib_add_ifaddr(ifa);
1185                 } endfor_ifa(in_dev);
1186 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1187                 fib_sync_up(dev, RTNH_F_DEAD);
1188 #endif
1189                 atomic_inc(&net->ipv4.dev_addr_genid);
1190                 rt_cache_flush(net);
1191                 break;
1192         case NETDEV_DOWN:
1193                 fib_disable_ip(dev, event, false);
1194                 break;
1195         case NETDEV_CHANGE:
1196                 flags = dev_get_flags(dev);
1197                 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1198                         fib_sync_up(dev, RTNH_F_LINKDOWN);
1199                 else
1200                         fib_sync_down_dev(dev, event, false);
1201                 /* fall through */
1202         case NETDEV_CHANGEMTU:
1203                 rt_cache_flush(net);
1204                 break;
1205         case NETDEV_CHANGEUPPER:
1206                 info = ptr;
1207                 /* flush all routes if dev is linked to or unlinked from
1208                  * an L3 master device (e.g., VRF)
1209                  */
1210                 if (info->upper_dev && netif_is_l3_master(info->upper_dev))
1211                         fib_disable_ip(dev, NETDEV_DOWN, true);
1212                 break;
1213         }
1214         return NOTIFY_DONE;
1215 }
1216
1217 static struct notifier_block fib_inetaddr_notifier = {
1218         .notifier_call = fib_inetaddr_event,
1219 };
1220
1221 static struct notifier_block fib_netdev_notifier = {
1222         .notifier_call = fib_netdev_event,
1223 };
1224
1225 static int __net_init ip_fib_net_init(struct net *net)
1226 {
1227         int err;
1228         size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1229
1230         /* Avoid false sharing : Use at least a full cache line */
1231         size = max_t(size_t, size, L1_CACHE_BYTES);
1232
1233         net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1234         if (!net->ipv4.fib_table_hash)
1235                 return -ENOMEM;
1236
1237         err = fib4_rules_init(net);
1238         if (err < 0)
1239                 goto fail;
1240         return 0;
1241
1242 fail:
1243         kfree(net->ipv4.fib_table_hash);
1244         return err;
1245 }
1246
1247 static void ip_fib_net_exit(struct net *net)
1248 {
1249         unsigned int i;
1250
1251         rtnl_lock();
1252 #ifdef CONFIG_IP_MULTIPLE_TABLES
1253         RCU_INIT_POINTER(net->ipv4.fib_local, NULL);
1254         RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1255         RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1256 #endif
1257         for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1258                 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1259                 struct hlist_node *tmp;
1260                 struct fib_table *tb;
1261
1262                 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1263                         hlist_del(&tb->tb_hlist);
1264                         fib_table_flush(tb);
1265                         fib_free_table(tb);
1266                 }
1267         }
1268
1269 #ifdef CONFIG_IP_MULTIPLE_TABLES
1270         fib4_rules_exit(net);
1271 #endif
1272         rtnl_unlock();
1273         kfree(net->ipv4.fib_table_hash);
1274 }
1275
1276 static int __net_init fib_net_init(struct net *net)
1277 {
1278         int error;
1279
1280 #ifdef CONFIG_IP_ROUTE_CLASSID
1281         net->ipv4.fib_num_tclassid_users = 0;
1282 #endif
1283         error = ip_fib_net_init(net);
1284         if (error < 0)
1285                 goto out;
1286         error = nl_fib_lookup_init(net);
1287         if (error < 0)
1288                 goto out_nlfl;
1289         error = fib_proc_init(net);
1290         if (error < 0)
1291                 goto out_proc;
1292 out:
1293         return error;
1294
1295 out_proc:
1296         nl_fib_lookup_exit(net);
1297 out_nlfl:
1298         ip_fib_net_exit(net);
1299         goto out;
1300 }
1301
1302 static void __net_exit fib_net_exit(struct net *net)
1303 {
1304         fib_proc_exit(net);
1305         nl_fib_lookup_exit(net);
1306         ip_fib_net_exit(net);
1307 }
1308
1309 static struct pernet_operations fib_net_ops = {
1310         .init = fib_net_init,
1311         .exit = fib_net_exit,
1312 };
1313
1314 void __init ip_fib_init(void)
1315 {
1316         rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1317         rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1318         rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1319
1320         register_pernet_subsys(&fib_net_ops);
1321         register_netdevice_notifier(&fib_netdev_notifier);
1322         register_inetaddr_notifier(&fib_inetaddr_notifier);
1323
1324         fib_trie_init();
1325 }