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