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                 if (colon) {
 513                         struct in_ifaddr *ifa;
 514                         struct in_device *in_dev = __in_dev_get_rtnl(dev);
 515                         if (!in_dev)
 516                                 return -ENODEV;
 517                         *colon = ':';
 518                         for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
 519                                 if (strcmp(ifa->ifa_label, devname) == 0)
 520                                         break;
 521                         if (!ifa)
 522                                 return -ENODEV;
 523                         cfg->fc_prefsrc = ifa->ifa_local;
 524                 }
 525         }
 526
 527         addr = sk_extract_addr(&rt->rt_gateway);
 528         if (rt->rt_gateway.sa_family == AF_INET && addr) {
 529                 unsigned int addr_type;
 530
 531                 cfg->fc_gw = addr;
 532                 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
 533                 if (rt->rt_flags & RTF_GATEWAY &&
 534                     addr_type == RTN_UNICAST)
 535                         cfg->fc_scope = RT_SCOPE_UNIVERSE;
 536         }
 537
 538         if (cmd == SIOCDELRT)
 539                 return 0;
 540
 541         if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
 542                 return -EINVAL;
 543
 544         if (cfg->fc_scope == RT_SCOPE_NOWHERE)
 545                 cfg->fc_scope = RT_SCOPE_LINK;
 546
 547         if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
 548                 struct nlattr *mx;
 549                 int len = 0;
 550
 551                 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
 552                 if (!mx)
 553                         return -ENOMEM;
 554
 555                 if (rt->rt_flags & RTF_MTU)
 556                         len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
 557
 558                 if (rt->rt_flags & RTF_WINDOW)
 559                         len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
 560
 561                 if (rt->rt_flags & RTF_IRTT)
 562                         len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
 563
 564                 cfg->fc_mx = mx;
 565                 cfg->fc_mx_len = len;
 566         }
 567
 568         return 0;
 569 }
 570
 571 /*
 572  * Handle IP routing ioctl calls.
 573  * These are used to manipulate the routing tables
 574  */
 575 int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 576 {
 577         struct fib_config cfg;
 578         struct rtentry rt;
 579         int err;
 580
 581         switch (cmd) {
 582         case SIOCADDRT:         /* Add a route */
 583         case SIOCDELRT:         /* Delete a route */
 584                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 585                         return -EPERM;
 586
 587                 if (copy_from_user(&rt, arg, sizeof(rt)))
 588                         return -EFAULT;
 589
 590                 rtnl_lock();
 591                 err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
 592                 if (err == 0) {
 593                         struct fib_table *tb;
 594
 595                         if (cmd == SIOCDELRT) {
 596                                 tb = fib_get_table(net, cfg.fc_table);
 597                                 if (tb)
 598                                         err = fib_table_delete(tb, &cfg);
 599                                 else
 600                                         err = -ESRCH;
 601                         } else {
 602                                 tb = fib_new_table(net, cfg.fc_table);
 603                                 if (tb)
 604                                         err = fib_table_insert(tb, &cfg);
 605                                 else
 606                                         err = -ENOBUFS;
 607                         }
 608
 609                         /* allocated by rtentry_to_fib_config() */
 610                         kfree(cfg.fc_mx);
 611                 }
 612                 rtnl_unlock();
 613                 return err;
 614         }
 615         return -EINVAL;
 616 }
 617
 618 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
 619         [RTA_DST]               = { .type = NLA_U32 },
 620         [RTA_SRC]               = { .type = NLA_U32 },
 621         [RTA_IIF]               = { .type = NLA_U32 },
 622         [RTA_OIF]               = { .type = NLA_U32 },
 623         [RTA_GATEWAY]           = { .type = NLA_U32 },
 624         [RTA_PRIORITY]          = { .type = NLA_U32 },
 625         [RTA_PREFSRC]           = { .type = NLA_U32 },
 626         [RTA_METRICS]           = { .type = NLA_NESTED },
 627         [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
 628         [RTA_FLOW]              = { .type = NLA_U32 },
 629         [RTA_ENCAP_TYPE]        = { .type = NLA_U16 },
 630         [RTA_ENCAP]             = { .type = NLA_NESTED },
 631 };
 632
 633 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
 634                              struct nlmsghdr *nlh, struct fib_config *cfg)
 635 {
 636         struct nlattr *attr;
 637         int err, remaining;
 638         struct rtmsg *rtm;
 639
 640         err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
 641         if (err < 0)
 642                 goto errout;
 643
 644         memset(cfg, 0, sizeof(*cfg));
 645
 646         rtm = nlmsg_data(nlh);
 647         cfg->fc_dst_len = rtm->rtm_dst_len;
 648         cfg->fc_tos = rtm->rtm_tos;
 649         cfg->fc_table = rtm->rtm_table;
 650         cfg->fc_protocol = rtm->rtm_protocol;
 651         cfg->fc_scope = rtm->rtm_scope;
 652         cfg->fc_type = rtm->rtm_type;
 653         cfg->fc_flags = rtm->rtm_flags;
 654         cfg->fc_nlflags = nlh->nlmsg_flags;
 655
 656         cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
 657         cfg->fc_nlinfo.nlh = nlh;
 658         cfg->fc_nlinfo.nl_net = net;
 659
 660         if (cfg->fc_type > RTN_MAX) {
 661                 err = -EINVAL;
 662                 goto errout;
 663         }
 664
 665         nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
 666                 switch (nla_type(attr)) {
 667                 case RTA_DST:
 668                         cfg->fc_dst = nla_get_be32(attr);
 669                         break;
 670                 case RTA_OIF:
 671                         cfg->fc_oif = nla_get_u32(attr);
 672                         break;
 673                 case RTA_GATEWAY:
 674                         cfg->fc_gw = nla_get_be32(attr);
 675                         break;
 676                 case RTA_PRIORITY:
 677                         cfg->fc_priority = nla_get_u32(attr);
 678                         break;
 679                 case RTA_PREFSRC:
 680                         cfg->fc_prefsrc = nla_get_be32(attr);
 681                         break;
 682                 case RTA_METRICS:
 683                         cfg->fc_mx = nla_data(attr);
 684                         cfg->fc_mx_len = nla_len(attr);
 685                         break;
 686                 case RTA_MULTIPATH:
 687                         cfg->fc_mp = nla_data(attr);
 688                         cfg->fc_mp_len = nla_len(attr);
 689                         break;
 690                 case RTA_FLOW:
 691                         cfg->fc_flow = nla_get_u32(attr);
 692                         break;
 693                 case RTA_TABLE:
 694                         cfg->fc_table = nla_get_u32(attr);
 695                         break;
 696                 case RTA_ENCAP:
 697                         cfg->fc_encap = attr;
 698                         break;
 699                 case RTA_ENCAP_TYPE:
 700                         cfg->fc_encap_type = nla_get_u16(attr);
 701                         break;
 702                 }
 703         }
 704
 705         return 0;
 706 errout:
 707         return err;
 708 }
 709
 710 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
 711 {
 712         struct net *net = sock_net(skb->sk);
 713         struct fib_config cfg;
 714         struct fib_table *tb;
 715         int err;
 716
 717         err = rtm_to_fib_config(net, skb, nlh, &cfg);
 718         if (err < 0)
 719                 goto errout;
 720
 721         tb = fib_get_table(net, cfg.fc_table);
 722         if (!tb) {
 723                 err = -ESRCH;
 724                 goto errout;
 725         }
 726
 727         err = fib_table_delete(tb, &cfg);
 728 errout:
 729         return err;
 730 }
 731
 732 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
 733 {
 734         struct net *net = sock_net(skb->sk);
 735         struct fib_config cfg;
 736         struct fib_table *tb;
 737         int err;
 738
 739         err = rtm_to_fib_config(net, skb, nlh, &cfg);
 740         if (err < 0)
 741                 goto errout;
 742
 743         tb = fib_new_table(net, cfg.fc_table);
 744         if (!tb) {
 745                 err = -ENOBUFS;
 746                 goto errout;
 747         }
 748
 749         err = fib_table_insert(tb, &cfg);
 750 errout:
 751         return err;
 752 }
 753
 754 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 755 {
 756         struct net *net = sock_net(skb->sk);
 757         unsigned int h, s_h;
 758         unsigned int e = 0, s_e;
 759         struct fib_table *tb;
 760         struct hlist_head *head;
 761         int dumped = 0;
 762
 763         if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
 764             ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
 765                 return skb->len;
 766
 767         s_h = cb->args[0];
 768         s_e = cb->args[1];
 769
 770         rcu_read_lock();
 771
 772         for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
 773                 e = 0;
 774                 head = &net->ipv4.fib_table_hash[h];
 775                 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
 776                         if (e < s_e)
 777                                 goto next;
 778                         if (dumped)
 779                                 memset(&cb->args[2], 0, sizeof(cb->args) -
 780                                                  2 * sizeof(cb->args[0]));
 781                         if (fib_table_dump(tb, skb, cb) < 0)
 782                                 goto out;
 783                         dumped = 1;
 784 next:
 785                         e++;
 786                 }
 787         }
 788 out:
 789         rcu_read_unlock();
 790
 791         cb->args[1] = e;
 792         cb->args[0] = h;
 793
 794         return skb->len;
 795 }
 796
 797 /* Prepare and feed intra-kernel routing request.
 798  * Really, it should be netlink message, but :-( netlink
 799  * can be not configured, so that we feed it directly
 800  * to fib engine. It is legal, because all events occur
 801  * only when netlink is already locked.
 802  */
 803 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
 804 {
 805         struct net *net = dev_net(ifa->ifa_dev->dev);
 806         u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
 807         struct fib_table *tb;
 808         struct fib_config cfg = {
 809                 .fc_protocol = RTPROT_KERNEL,
 810                 .fc_type = type,
 811                 .fc_dst = dst,
 812                 .fc_dst_len = dst_len,
 813                 .fc_prefsrc = ifa->ifa_local,
 814                 .fc_oif = ifa->ifa_dev->dev->ifindex,
 815                 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
 816                 .fc_nlinfo = {
 817                         .nl_net = net,
 818                 },
 819         };
 820
 821         if (!tb_id)
 822                 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
 823
 824         tb = fib_new_table(net, tb_id);
 825         if (!tb)
 826                 return;
 827
 828         cfg.fc_table = tb->tb_id;
 829
 830         if (type != RTN_LOCAL)
 831                 cfg.fc_scope = RT_SCOPE_LINK;
 832         else
 833                 cfg.fc_scope = RT_SCOPE_HOST;
 834
 835         if (cmd == RTM_NEWROUTE)
 836                 fib_table_insert(tb, &cfg);
 837         else
 838                 fib_table_delete(tb, &cfg);
 839 }
 840
 841 void fib_add_ifaddr(struct in_ifaddr *ifa)
 842 {
 843         struct in_device *in_dev = ifa->ifa_dev;
 844         struct net_device *dev = in_dev->dev;
 845         struct in_ifaddr *prim = ifa;
 846         __be32 mask = ifa->ifa_mask;
 847         __be32 addr = ifa->ifa_local;
 848         __be32 prefix = ifa->ifa_address & mask;
 849
 850         if (ifa->ifa_flags & IFA_F_SECONDARY) {
 851                 prim = inet_ifa_byprefix(in_dev, prefix, mask);
 852                 if (!prim) {
 853                         pr_warn("%s: bug: prim == NULL\n", __func__);
 854                         return;
 855                 }
 856         }
 857
 858         fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
 859
 860         if (!(dev->flags & IFF_UP))
 861                 return;
 862
 863         /* Add broadcast address, if it is explicitly assigned. */
 864         if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
 865                 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
 866
 867         if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
 868             (prefix != addr || ifa->ifa_prefixlen < 32)) {
 869                 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
 870                         fib_magic(RTM_NEWROUTE,
 871                                   dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
 872                                   prefix, ifa->ifa_prefixlen, prim);
 873
 874                 /* Add network specific broadcasts, when it takes a sense */
 875                 if (ifa->ifa_prefixlen < 31) {
 876                         fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
 877                         fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
 878                                   32, prim);
 879                 }
 880         }
 881 }
 882
 883 /* Delete primary or secondary address.
 884  * Optionally, on secondary address promotion consider the addresses
 885  * from subnet iprim as deleted, even if they are in device list.
 886  * In this case the secondary ifa can be in device list.
 887  */
 888 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
 889 {
 890         struct in_device *in_dev = ifa->ifa_dev;
 891         struct net_device *dev = in_dev->dev;
 892         struct in_ifaddr *ifa1;
 893         struct in_ifaddr *prim = ifa, *prim1 = NULL;
 894         __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
 895         __be32 any = ifa->ifa_address & ifa->ifa_mask;
 896 #define LOCAL_OK        1
 897 #define BRD_OK          2
 898 #define BRD0_OK         4
 899 #define BRD1_OK         8
 900         unsigned int ok = 0;
 901         int subnet = 0;         /* Primary network */
 902         int gone = 1;           /* Address is missing */
 903         int same_prefsrc = 0;   /* Another primary with same IP */
 904
 905         if (ifa->ifa_flags & IFA_F_SECONDARY) {
 906                 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
 907                 if (!prim) {
 908                         /* if the device has been deleted, we don't perform
 909                          * address promotion
 910                          */
 911                         if (!in_dev->dead)
 912                                 pr_warn("%s: bug: prim == NULL\n", __func__);
 913                         return;
 914                 }
 915                 if (iprim && iprim != prim) {
 916                         pr_warn("%s: bug: iprim != prim\n", __func__);
 917                         return;
 918                 }
 919         } else if (!ipv4_is_zeronet(any) &&
 920                    (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
 921                 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
 922                         fib_magic(RTM_DELROUTE,
 923                                   dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
 924                                   any, ifa->ifa_prefixlen, prim);
 925                 subnet = 1;
 926         }
 927
 928         if (in_dev->dead)
 929                 goto no_promotions;
 930
 931         /* Deletion is more complicated than add.
 932          * We should take care of not to delete too much :-)
 933          *
 934          * Scan address list to be sure that addresses are really gone.
 935          */
 936
 937         for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
 938                 if (ifa1 == ifa) {
 939                         /* promotion, keep the IP */
 940                         gone = 0;
 941                         continue;
 942                 }
 943                 /* Ignore IFAs from our subnet */
 944                 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
 945                     inet_ifa_match(ifa1->ifa_address, iprim))
 946                         continue;
 947
 948                 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
 949                 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
 950                         /* Another address from our subnet? */
 951                         if (ifa1->ifa_mask == prim->ifa_mask &&
 952                             inet_ifa_match(ifa1->ifa_address, prim))
 953                                 prim1 = prim;
 954                         else {
 955                                 /* We reached the secondaries, so
 956                                  * same_prefsrc should be determined.
 957                                  */
 958                                 if (!same_prefsrc)
 959                                         continue;
 960                                 /* Search new prim1 if ifa1 is not
 961                                  * using the current prim1
 962                                  */
 963                                 if (!prim1 ||
 964                                     ifa1->ifa_mask != prim1->ifa_mask ||
 965                                     !inet_ifa_match(ifa1->ifa_address, prim1))
 966                                         prim1 = inet_ifa_byprefix(in_dev,
 967                                                         ifa1->ifa_address,
 968                                                         ifa1->ifa_mask);
 969                                 if (!prim1)
 970                                         continue;
 971                                 if (prim1->ifa_local != prim->ifa_local)
 972                                         continue;
 973                         }
 974                 } else {
 975                         if (prim->ifa_local != ifa1->ifa_local)
 976                                 continue;
 977                         prim1 = ifa1;
 978                         if (prim != prim1)
 979                                 same_prefsrc = 1;
 980                 }
 981                 if (ifa->ifa_local == ifa1->ifa_local)
 982                         ok |= LOCAL_OK;
 983                 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
 984                         ok |= BRD_OK;
 985                 if (brd == ifa1->ifa_broadcast)
 986                         ok |= BRD1_OK;
 987                 if (any == ifa1->ifa_broadcast)
 988                         ok |= BRD0_OK;
 989                 /* primary has network specific broadcasts */
 990                 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
 991                         __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
 992                         __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
 993
 994                         if (!ipv4_is_zeronet(any1)) {
 995                                 if (ifa->ifa_broadcast == brd1 ||
 996                                     ifa->ifa_broadcast == any1)
 997                                         ok |= BRD_OK;
 998                                 if (brd == brd1 || brd == any1)
 999                                         ok |= BRD1_OK;
1000                                 if (any == brd1 || any == any1)
1001                                         ok |= BRD0_OK;
1002                         }
1003                 }
1004         }
1005
1006 no_promotions:
1007         if (!(ok & BRD_OK))
1008                 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
1009         if (subnet && ifa->ifa_prefixlen < 31) {
1010                 if (!(ok & BRD1_OK))
1011                         fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
1012                 if (!(ok & BRD0_OK))
1013                         fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
1014         }
1015         if (!(ok & LOCAL_OK)) {
1016                 unsigned int addr_type;
1017
1018                 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
1019
1020                 /* Check, that this local address finally disappeared. */
1021                 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1022                                                      ifa->ifa_local);
1023                 if (gone && addr_type != RTN_LOCAL) {
1024                         /* And the last, but not the least thing.
1025                          * We must flush stray FIB entries.
1026                          *
1027                          * First of all, we scan fib_info list searching
1028                          * for stray nexthop entries, then ignite fib_flush.
1029                          */
1030                         if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local))
1031                                 fib_flush(dev_net(dev));
1032                 }
1033         }
1034 #undef LOCAL_OK
1035 #undef BRD_OK
1036 #undef BRD0_OK
1037 #undef BRD1_OK
1038 }
1039
1040 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1041 {
1042
1043         struct fib_result       res;
1044         struct flowi4           fl4 = {
1045                 .flowi4_mark = frn->fl_mark,
1046                 .daddr = frn->fl_addr,
1047                 .flowi4_tos = frn->fl_tos,
1048                 .flowi4_scope = frn->fl_scope,
1049         };
1050         struct fib_table *tb;
1051
1052         rcu_read_lock();
1053
1054         tb = fib_get_table(net, frn->tb_id_in);
1055
1056         frn->err = -ENOENT;
1057         if (tb) {
1058                 local_bh_disable();
1059
1060                 frn->tb_id = tb->tb_id;
1061                 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1062
1063                 if (!frn->err) {
1064                         frn->prefixlen = res.prefixlen;
1065                         frn->nh_sel = res.nh_sel;
1066                         frn->type = res.type;
1067                         frn->scope = res.scope;
1068                 }
1069                 local_bh_enable();
1070         }
1071
1072         rcu_read_unlock();
1073 }
1074
1075 static void nl_fib_input(struct sk_buff *skb)
1076 {
1077         struct net *net;
1078         struct fib_result_nl *frn;
1079         struct nlmsghdr *nlh;
1080         u32 portid;
1081
1082         net = sock_net(skb->sk);
1083         nlh = nlmsg_hdr(skb);
1084         if (skb->len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len ||
1085             nlmsg_len(nlh) < sizeof(*frn))
1086                 return;
1087
1088         skb = netlink_skb_clone(skb, GFP_KERNEL);
1089         if (!skb)
1090                 return;
1091         nlh = nlmsg_hdr(skb);
1092
1093         frn = (struct fib_result_nl *) nlmsg_data(nlh);
1094         nl_fib_lookup(net, frn);
1095
1096         portid = NETLINK_CB(skb).portid;      /* netlink portid */
1097         NETLINK_CB(skb).portid = 0;        /* from kernel */
1098         NETLINK_CB(skb).dst_group = 0;  /* unicast */
1099         netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1100 }
1101
1102 static int __net_init nl_fib_lookup_init(struct net *net)
1103 {
1104         struct sock *sk;
1105         struct netlink_kernel_cfg cfg = {
1106                 .input  = nl_fib_input,
1107         };
1108
1109         sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1110         if (!sk)
1111                 return -EAFNOSUPPORT;
1112         net->ipv4.fibnl = sk;
1113         return 0;
1114 }
1115
1116 static void nl_fib_lookup_exit(struct net *net)
1117 {
1118         netlink_kernel_release(net->ipv4.fibnl);
1119         net->ipv4.fibnl = NULL;
1120 }
1121
1122 static void fib_disable_ip(struct net_device *dev, unsigned long event,
1123                            bool force)
1124 {
1125         if (fib_sync_down_dev(dev, event, force))
1126                 fib_flush(dev_net(dev));
1127         rt_cache_flush(dev_net(dev));
1128         arp_ifdown(dev);
1129 }
1130
1131 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1132 {
1133         struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1134         struct net_device *dev = ifa->ifa_dev->dev;
1135         struct net *net = dev_net(dev);
1136
1137         switch (event) {
1138         case NETDEV_UP:
1139                 fib_add_ifaddr(ifa);
1140 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1141                 fib_sync_up(dev, RTNH_F_DEAD);
1142 #endif
1143                 atomic_inc(&net->ipv4.dev_addr_genid);
1144                 rt_cache_flush(dev_net(dev));
1145                 break;
1146         case NETDEV_DOWN:
1147                 fib_del_ifaddr(ifa, NULL);
1148                 atomic_inc(&net->ipv4.dev_addr_genid);
1149                 if (!ifa->ifa_dev->ifa_list) {
1150                         /* Last address was deleted from this interface.
1151                          * Disable IP.
1152                          */
1153                         fib_disable_ip(dev, event, true);
1154                 } else {
1155                         rt_cache_flush(dev_net(dev));
1156                 }
1157                 break;
1158         }
1159         return NOTIFY_DONE;
1160 }
1161
1162 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1163 {
1164         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1165         struct netdev_notifier_changeupper_info *info;
1166         struct in_device *in_dev;
1167         struct net *net = dev_net(dev);
1168         unsigned int flags;
1169
1170         if (event == NETDEV_UNREGISTER) {
1171                 fib_disable_ip(dev, event, true);
1172                 rt_flush_dev(dev);
1173                 return NOTIFY_DONE;
1174         }
1175
1176         in_dev = __in_dev_get_rtnl(dev);
1177         if (!in_dev)
1178                 return NOTIFY_DONE;
1179
1180         switch (event) {
1181         case NETDEV_UP:
1182                 for_ifa(in_dev) {
1183                         fib_add_ifaddr(ifa);
1184                 } endfor_ifa(in_dev);
1185 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1186                 fib_sync_up(dev, RTNH_F_DEAD);
1187 #endif
1188                 atomic_inc(&net->ipv4.dev_addr_genid);
1189                 rt_cache_flush(net);
1190                 break;
1191         case NETDEV_DOWN:
1192                 fib_disable_ip(dev, event, false);
1193                 break;
1194         case NETDEV_CHANGE:
1195                 flags = dev_get_flags(dev);
1196                 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1197                         fib_sync_up(dev, RTNH_F_LINKDOWN);
1198                 else
1199                         fib_sync_down_dev(dev, event, false);
1200                 /* fall through */
1201         case NETDEV_CHANGEMTU:
1202                 rt_cache_flush(net);
1203                 break;
1204         case NETDEV_CHANGEUPPER:
1205                 info = ptr;
1206                 /* flush all routes if dev is linked to or unlinked from
1207                  * an L3 master device (e.g., VRF)
1208                  */
1209                 if (info->upper_dev && netif_is_l3_master(info->upper_dev))
1210                         fib_disable_ip(dev, NETDEV_DOWN, true);
1211                 break;
1212         }
1213         return NOTIFY_DONE;
1214 }
1215
1216 static struct notifier_block fib_inetaddr_notifier = {
1217         .notifier_call = fib_inetaddr_event,
1218 };
1219
1220 static struct notifier_block fib_netdev_notifier = {
1221         .notifier_call = fib_netdev_event,
1222 };
1223
1224 static int __net_init ip_fib_net_init(struct net *net)
1225 {
1226         int err;
1227         size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1228
1229         /* Avoid false sharing : Use at least a full cache line */
1230         size = max_t(size_t, size, L1_CACHE_BYTES);
1231
1232         net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1233         if (!net->ipv4.fib_table_hash)
1234                 return -ENOMEM;
1235
1236         err = fib4_rules_init(net);
1237         if (err < 0)
1238                 goto fail;
1239         return 0;
1240
1241 fail:
1242         kfree(net->ipv4.fib_table_hash);
1243         return err;
1244 }
1245
1246 static void ip_fib_net_exit(struct net *net)
1247 {
1248         unsigned int i;
1249
1250         rtnl_lock();
1251 #ifdef CONFIG_IP_MULTIPLE_TABLES
1252         RCU_INIT_POINTER(net->ipv4.fib_local, NULL);
1253         RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1254         RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1255 #endif
1256         for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1257                 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1258                 struct hlist_node *tmp;
1259                 struct fib_table *tb;
1260
1261                 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1262                         hlist_del(&tb->tb_hlist);
1263                         fib_table_flush(tb);
1264                         fib_free_table(tb);
1265                 }
1266         }
1267
1268 #ifdef CONFIG_IP_MULTIPLE_TABLES
1269         fib4_rules_exit(net);
1270 #endif
1271         rtnl_unlock();
1272         kfree(net->ipv4.fib_table_hash);
1273 }
1274
1275 static int __net_init fib_net_init(struct net *net)
1276 {
1277         int error;
1278
1279 #ifdef CONFIG_IP_ROUTE_CLASSID
1280         net->ipv4.fib_num_tclassid_users = 0;
1281 #endif
1282         error = ip_fib_net_init(net);
1283         if (error < 0)
1284                 goto out;
1285         error = nl_fib_lookup_init(net);
1286         if (error < 0)
1287                 goto out_nlfl;
1288         error = fib_proc_init(net);
1289         if (error < 0)
1290                 goto out_proc;
1291 out:
1292         return error;
1293
1294 out_proc:
1295         nl_fib_lookup_exit(net);
1296 out_nlfl:
1297         ip_fib_net_exit(net);
1298         goto out;
1299 }
1300
1301 static void __net_exit fib_net_exit(struct net *net)
1302 {
1303         fib_proc_exit(net);
1304         nl_fib_lookup_exit(net);
1305         ip_fib_net_exit(net);
1306 }
1307
1308 static struct pernet_operations fib_net_ops = {
1309         .init = fib_net_init,
1310         .exit = fib_net_exit,
1311 };
1312
1313 void __init ip_fib_init(void)
1314 {
1315         rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1316         rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1317         rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1318
1319         register_pernet_subsys(&fib_net_ops);
1320         register_netdevice_notifier(&fib_netdev_notifier);
1321         register_inetaddr_notifier(&fib_inetaddr_notifier);
1322
1323         fib_trie_init();
1324 }