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 <linux/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 <net/lwtunnel.h>
  50 #include <trace/events/fib.h>
  51
  52 #ifndef CONFIG_IP_MULTIPLE_TABLES
  53
  54 static int __net_init fib4_rules_init(struct net *net)
  55 {
  56         struct fib_table *local_table, *main_table;
  57
  58         main_table  = fib_trie_table(RT_TABLE_MAIN, NULL);
  59         if (!main_table)
  60                 return -ENOMEM;
  61
  62         local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
  63         if (!local_table)
  64                 goto fail;
  65
  66         hlist_add_head_rcu(&local_table->tb_hlist,
  67                                 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
  68         hlist_add_head_rcu(&main_table->tb_hlist,
  69                                 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
  70         return 0;
  71
  72 fail:
  73         fib_free_table(main_table);
  74         return -ENOMEM;
  75 }
  76 #else
  77
  78 struct fib_table *fib_new_table(struct net *net, u32 id)
  79 {
  80         struct fib_table *tb, *alias = NULL;
  81         unsigned int h;
  82
  83         if (id == 0)
  84                 id = RT_TABLE_MAIN;
  85         tb = fib_get_table(net, id);
  86         if (tb)
  87                 return tb;
  88
  89         if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules)
  90                 alias = fib_new_table(net, RT_TABLE_MAIN);
  91
  92         tb = fib_trie_table(id, alias);
  93         if (!tb)
  94                 return NULL;
  95
  96         switch (id) {
  97         case RT_TABLE_MAIN:
  98                 rcu_assign_pointer(net->ipv4.fib_main, tb);
  99                 break;
 100         case RT_TABLE_DEFAULT:
 101                 rcu_assign_pointer(net->ipv4.fib_default, tb);
 102                 break;
 103         default:
 104                 break;
 105         }
 106
 107         h = id & (FIB_TABLE_HASHSZ - 1);
 108         hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
 109         return tb;
 110 }
 111 EXPORT_SYMBOL_GPL(fib_new_table);
 112
 113 /* caller must hold either rtnl or rcu read lock */
 114 struct fib_table *fib_get_table(struct net *net, u32 id)
 115 {
 116         struct fib_table *tb;
 117         struct hlist_head *head;
 118         unsigned int h;
 119
 120         if (id == 0)
 121                 id = RT_TABLE_MAIN;
 122         h = id & (FIB_TABLE_HASHSZ - 1);
 123
 124         head = &net->ipv4.fib_table_hash[h];
 125         hlist_for_each_entry_rcu(tb, head, tb_hlist) {
 126                 if (tb->tb_id == id)
 127                         return tb;
 128         }
 129         return NULL;
 130 }
 131 #endif /* CONFIG_IP_MULTIPLE_TABLES */
 132
 133 static void fib_replace_table(struct net *net, struct fib_table *old,
 134                               struct fib_table *new)
 135 {
 136 #ifdef CONFIG_IP_MULTIPLE_TABLES
 137         switch (new->tb_id) {
 138         case RT_TABLE_MAIN:
 139                 rcu_assign_pointer(net->ipv4.fib_main, new);
 140                 break;
 141         case RT_TABLE_DEFAULT:
 142                 rcu_assign_pointer(net->ipv4.fib_default, new);
 143                 break;
 144         default:
 145                 break;
 146         }
 147
 148 #endif
 149         /* replace the old table in the hlist */
 150         hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
 151 }
 152
 153 int fib_unmerge(struct net *net)
 154 {
 155         struct fib_table *old, *new, *main_table;
 156
 157         /* attempt to fetch local table if it has been allocated */
 158         old = fib_get_table(net, RT_TABLE_LOCAL);
 159         if (!old)
 160                 return 0;
 161
 162         new = fib_trie_unmerge(old);
 163         if (!new)
 164                 return -ENOMEM;
 165
 166         /* table is already unmerged */
 167         if (new == old)
 168                 return 0;
 169
 170         /* replace merged table with clean table */
 171         fib_replace_table(net, old, new);
 172         fib_free_table(old);
 173
 174         /* attempt to fetch main table if it has been allocated */
 175         main_table = fib_get_table(net, RT_TABLE_MAIN);
 176         if (!main_table)
 177                 return 0;
 178
 179         /* flush local entries from main table */
 180         fib_table_flush_external(main_table);
 181
 182         return 0;
 183 }
 184
 185 static void fib_flush(struct net *net)
 186 {
 187         int flushed = 0;
 188         unsigned int h;
 189
 190         for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
 191                 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
 192                 struct hlist_node *tmp;
 193                 struct fib_table *tb;
 194
 195                 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
 196                         flushed += fib_table_flush(net, tb);
 197         }
 198
 199         if (flushed)
 200                 rt_cache_flush(net);
 201 }
 202
 203 /*
 204  * Find address type as if only "dev" was present in the system. If
 205  * on_dev is NULL then all interfaces are taken into consideration.
 206  */
 207 static inline unsigned int __inet_dev_addr_type(struct net *net,
 208                                                 const struct net_device *dev,
 209                                                 __be32 addr, u32 tb_id)
 210 {
 211         struct flowi4           fl4 = { .daddr = addr };
 212         struct fib_result       res;
 213         unsigned int ret = RTN_BROADCAST;
 214         struct fib_table *table;
 215
 216         if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
 217                 return RTN_BROADCAST;
 218         if (ipv4_is_multicast(addr))
 219                 return RTN_MULTICAST;
 220
 221         rcu_read_lock();
 222
 223         table = fib_get_table(net, tb_id);
 224         if (table) {
 225                 ret = RTN_UNICAST;
 226                 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
 227                         if (!dev || dev == res.fi->fib_dev)
 228                                 ret = res.type;
 229                 }
 230         }
 231
 232         rcu_read_unlock();
 233         return ret;
 234 }
 235
 236 unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
 237 {
 238         return __inet_dev_addr_type(net, NULL, addr, tb_id);
 239 }
 240 EXPORT_SYMBOL(inet_addr_type_table);
 241
 242 unsigned int inet_addr_type(struct net *net, __be32 addr)
 243 {
 244         return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
 245 }
 246 EXPORT_SYMBOL(inet_addr_type);
 247
 248 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
 249                                 __be32 addr)
 250 {
 251         u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
 252
 253         return __inet_dev_addr_type(net, dev, addr, rt_table);
 254 }
 255 EXPORT_SYMBOL(inet_dev_addr_type);
 256
 257 /* inet_addr_type with dev == NULL but using the table from a dev
 258  * if one is associated
 259  */
 260 unsigned int inet_addr_type_dev_table(struct net *net,
 261                                       const struct net_device *dev,
 262                                       __be32 addr)
 263 {
 264         u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
 265
 266         return __inet_dev_addr_type(net, NULL, addr, rt_table);
 267 }
 268 EXPORT_SYMBOL(inet_addr_type_dev_table);
 269
 270 __be32 fib_compute_spec_dst(struct sk_buff *skb)
 271 {
 272         struct net_device *dev = skb->dev;
 273         struct in_device *in_dev;
 274         struct fib_result res;
 275         struct rtable *rt;
 276         struct net *net;
 277         int scope;
 278
 279         rt = skb_rtable(skb);
 280         if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
 281             RTCF_LOCAL)
 282                 return ip_hdr(skb)->daddr;
 283
 284         in_dev = __in_dev_get_rcu(dev);
 285         BUG_ON(!in_dev);
 286
 287         net = dev_net(dev);
 288
 289         scope = RT_SCOPE_UNIVERSE;
 290         if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
 291                 struct flowi4 fl4 = {
 292                         .flowi4_iif = LOOPBACK_IFINDEX,
 293                         .daddr = ip_hdr(skb)->saddr,
 294                         .flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
 295                         .flowi4_scope = scope,
 296                         .flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0,
 297                 };
 298                 if (!fib_lookup(net, &fl4, &res, 0))
 299                         return FIB_RES_PREFSRC(net, res);
 300         } else {
 301                 scope = RT_SCOPE_LINK;
 302         }
 303
 304         return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
 305 }
 306
 307 /* Given (packet source, input interface) and optional (dst, oif, tos):
 308  * - (main) check, that source is valid i.e. not broadcast or our local
 309  *   address.
 310  * - figure out what "logical" interface this packet arrived
 311  *   and calculate "specific destination" address.
 312  * - check, that packet arrived from expected physical interface.
 313  * called with rcu_read_lock()
 314  */
 315 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 316                                  u8 tos, int oif, struct net_device *dev,
 317                                  int rpf, struct in_device *idev, u32 *itag)
 318 {
 319         int ret, no_addr;
 320         struct fib_result res;
 321         struct flowi4 fl4;
 322         struct net *net = dev_net(dev);
 323         bool dev_match;
 324
 325         fl4.flowi4_oif = 0;
 326         fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
 327         if (!fl4.flowi4_iif)
 328                 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
 329         fl4.daddr = src;
 330         fl4.saddr = dst;
 331         fl4.flowi4_tos = tos;
 332         fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
 333         fl4.flowi4_tun_key.tun_id = 0;
 334         fl4.flowi4_flags = 0;
 335         fl4.flowi4_uid = sock_net_uid(net, NULL);
 336
 337         no_addr = idev->ifa_list == NULL;
 338
 339         fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
 340
 341         trace_fib_validate_source(dev, &fl4);
 342
 343         if (fib_lookup(net, &fl4, &res, 0))
 344                 goto last_resort;
 345         if (res.type != RTN_UNICAST &&
 346             (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
 347                 goto e_inval;
 348         if (!rpf && !fib_num_tclassid_users(net) &&
 349             (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev)))
 350                 goto last_resort;
 351         fib_combine_itag(itag, &res);
 352         dev_match = false;
 353
 354 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 355         for (ret = 0; ret < res.fi->fib_nhs; ret++) {
 356                 struct fib_nh *nh = &res.fi->fib_nh[ret];
 357
 358                 if (nh->nh_dev == dev) {
 359                         dev_match = true;
 360                         break;
 361                 } else if (l3mdev_master_ifindex_rcu(nh->nh_dev) == dev->ifindex) {
 362                         dev_match = true;
 363                         break;
 364                 }
 365         }
 366 #else
 367         if (FIB_RES_DEV(res) == dev)
 368                 dev_match = true;
 369 #endif
 370         if (dev_match) {
 371                 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
 372                 return ret;
 373         }
 374         if (no_addr)
 375                 goto last_resort;
 376         if (rpf == 1)
 377                 goto e_rpf;
 378         fl4.flowi4_oif = dev->ifindex;
 379
 380         ret = 0;
 381         if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
 382                 if (res.type == RTN_UNICAST)
 383                         ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
 384         }
 385         return ret;
 386
 387 last_resort:
 388         if (rpf)
 389                 goto e_rpf;
 390         *itag = 0;
 391         return 0;
 392
 393 e_inval:
 394         return -EINVAL;
 395 e_rpf:
 396         return -EXDEV;
 397 }
 398
 399 /* Ignore rp_filter for packets protected by IPsec. */
 400 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 401                         u8 tos, int oif, struct net_device *dev,
 402                         struct in_device *idev, u32 *itag)
 403 {
 404         int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
 405
 406         if (!r && !fib_num_tclassid_users(dev_net(dev)) &&
 407             IN_DEV_ACCEPT_LOCAL(idev) &&
 408             (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
 409                 *itag = 0;
 410                 return 0;
 411         }
 412         return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
 413 }
 414
 415 static inline __be32 sk_extract_addr(struct sockaddr *addr)
 416 {
 417         return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
 418 }
 419
 420 static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
 421 {
 422         struct nlattr *nla;
 423
 424         nla = (struct nlattr *) ((char *) mx + len);
 425         nla->nla_type = type;
 426         nla->nla_len = nla_attr_size(4);
 427         *(u32 *) nla_data(nla) = value;
 428
 429         return len + nla_total_size(4);
 430 }
 431
 432 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
 433                                  struct fib_config *cfg)
 434 {
 435         __be32 addr;
 436         int plen;
 437
 438         memset(cfg, 0, sizeof(*cfg));
 439         cfg->fc_nlinfo.nl_net = net;
 440
 441         if (rt->rt_dst.sa_family != AF_INET)
 442                 return -EAFNOSUPPORT;
 443
 444         /*
 445          * Check mask for validity:
 446          * a) it must be contiguous.
 447          * b) destination must have all host bits clear.
 448          * c) if application forgot to set correct family (AF_INET),
 449          *    reject request unless it is absolutely clear i.e.
 450          *    both family and mask are zero.
 451          */
 452         plen = 32;
 453         addr = sk_extract_addr(&rt->rt_dst);
 454         if (!(rt->rt_flags & RTF_HOST)) {
 455                 __be32 mask = sk_extract_addr(&rt->rt_genmask);
 456
 457                 if (rt->rt_genmask.sa_family != AF_INET) {
 458                         if (mask || rt->rt_genmask.sa_family)
 459                                 return -EAFNOSUPPORT;
 460                 }
 461
 462                 if (bad_mask(mask, addr))
 463                         return -EINVAL;
 464
 465                 plen = inet_mask_len(mask);
 466         }
 467
 468         cfg->fc_dst_len = plen;
 469         cfg->fc_dst = addr;
 470
 471         if (cmd != SIOCDELRT) {
 472                 cfg->fc_nlflags = NLM_F_CREATE;
 473                 cfg->fc_protocol = RTPROT_BOOT;
 474         }
 475
 476         if (rt->rt_metric)
 477                 cfg->fc_priority = rt->rt_metric - 1;
 478
 479         if (rt->rt_flags & RTF_REJECT) {
 480                 cfg->fc_scope = RT_SCOPE_HOST;
 481                 cfg->fc_type = RTN_UNREACHABLE;
 482                 return 0;
 483         }
 484
 485         cfg->fc_scope = RT_SCOPE_NOWHERE;
 486         cfg->fc_type = RTN_UNICAST;
 487
 488         if (rt->rt_dev) {
 489                 char *colon;
 490                 struct net_device *dev;
 491                 char devname[IFNAMSIZ];
 492
 493                 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
 494                         return -EFAULT;
 495
 496                 devname[IFNAMSIZ-1] = 0;
 497                 colon = strchr(devname, ':');
 498                 if (colon)
 499                         *colon = 0;
 500                 dev = __dev_get_by_name(net, devname);
 501                 if (!dev)
 502                         return -ENODEV;
 503                 cfg->fc_oif = dev->ifindex;
 504                 cfg->fc_table = l3mdev_fib_table(dev);
 505                 if (colon) {
 506                         struct in_ifaddr *ifa;
 507                         struct in_device *in_dev = __in_dev_get_rtnl(dev);
 508                         if (!in_dev)
 509                                 return -ENODEV;
 510                         *colon = ':';
 511                         for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
 512                                 if (strcmp(ifa->ifa_label, devname) == 0)
 513                                         break;
 514                         if (!ifa)
 515                                 return -ENODEV;
 516                         cfg->fc_prefsrc = ifa->ifa_local;
 517                 }
 518         }
 519
 520         addr = sk_extract_addr(&rt->rt_gateway);
 521         if (rt->rt_gateway.sa_family == AF_INET && addr) {
 522                 unsigned int addr_type;
 523
 524                 cfg->fc_gw = addr;
 525                 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
 526                 if (rt->rt_flags & RTF_GATEWAY &&
 527                     addr_type == RTN_UNICAST)
 528                         cfg->fc_scope = RT_SCOPE_UNIVERSE;
 529         }
 530
 531         if (cmd == SIOCDELRT)
 532                 return 0;
 533
 534         if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
 535                 return -EINVAL;
 536
 537         if (cfg->fc_scope == RT_SCOPE_NOWHERE)
 538                 cfg->fc_scope = RT_SCOPE_LINK;
 539
 540         if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
 541                 struct nlattr *mx;
 542                 int len = 0;
 543
 544                 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
 545                 if (!mx)
 546                         return -ENOMEM;
 547
 548                 if (rt->rt_flags & RTF_MTU)
 549                         len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
 550
 551                 if (rt->rt_flags & RTF_WINDOW)
 552                         len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
 553
 554                 if (rt->rt_flags & RTF_IRTT)
 555                         len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
 556
 557                 cfg->fc_mx = mx;
 558                 cfg->fc_mx_len = len;
 559         }
 560
 561         return 0;
 562 }
 563
 564 /*
 565  * Handle IP routing ioctl calls.
 566  * These are used to manipulate the routing tables
 567  */
 568 int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 569 {
 570         struct fib_config cfg;
 571         struct rtentry rt;
 572         int err;
 573
 574         switch (cmd) {
 575         case SIOCADDRT:         /* Add a route */
 576         case SIOCDELRT:         /* Delete a route */
 577                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 578                         return -EPERM;
 579
 580                 if (copy_from_user(&rt, arg, sizeof(rt)))
 581                         return -EFAULT;
 582
 583                 rtnl_lock();
 584                 err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
 585                 if (err == 0) {
 586                         struct fib_table *tb;
 587
 588                         if (cmd == SIOCDELRT) {
 589                                 tb = fib_get_table(net, cfg.fc_table);
 590                                 if (tb)
 591                                         err = fib_table_delete(net, tb, &cfg);
 592                                 else
 593                                         err = -ESRCH;
 594                         } else {
 595                                 tb = fib_new_table(net, cfg.fc_table);
 596                                 if (tb)
 597                                         err = fib_table_insert(net, tb, &cfg);
 598                                 else
 599                                         err = -ENOBUFS;
 600                         }
 601
 602                         /* allocated by rtentry_to_fib_config() */
 603                         kfree(cfg.fc_mx);
 604                 }
 605                 rtnl_unlock();
 606                 return err;
 607         }
 608         return -EINVAL;
 609 }
 610
 611 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
 612         [RTA_DST]               = { .type = NLA_U32 },
 613         [RTA_SRC]               = { .type = NLA_U32 },
 614         [RTA_IIF]               = { .type = NLA_U32 },
 615         [RTA_OIF]               = { .type = NLA_U32 },
 616         [RTA_GATEWAY]           = { .type = NLA_U32 },
 617         [RTA_PRIORITY]          = { .type = NLA_U32 },
 618         [RTA_PREFSRC]           = { .type = NLA_U32 },
 619         [RTA_METRICS]           = { .type = NLA_NESTED },
 620         [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
 621         [RTA_FLOW]              = { .type = NLA_U32 },
 622         [RTA_ENCAP_TYPE]        = { .type = NLA_U16 },
 623         [RTA_ENCAP]             = { .type = NLA_NESTED },
 624         [RTA_UID]               = { .type = NLA_U32 },
 625         [RTA_MARK]              = { .type = NLA_U32 },
 626 };
 627
 628 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
 629                              struct nlmsghdr *nlh, struct fib_config *cfg)
 630 {
 631         struct nlattr *attr;
 632         int err, remaining;
 633         struct rtmsg *rtm;
 634
 635         err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy,
 636                              NULL);
 637         if (err < 0)
 638                 goto errout;
 639
 640         memset(cfg, 0, sizeof(*cfg));
 641
 642         rtm = nlmsg_data(nlh);
 643         cfg->fc_dst_len = rtm->rtm_dst_len;
 644         cfg->fc_tos = rtm->rtm_tos;
 645         cfg->fc_table = rtm->rtm_table;
 646         cfg->fc_protocol = rtm->rtm_protocol;
 647         cfg->fc_scope = rtm->rtm_scope;
 648         cfg->fc_type = rtm->rtm_type;
 649         cfg->fc_flags = rtm->rtm_flags;
 650         cfg->fc_nlflags = nlh->nlmsg_flags;
 651
 652         cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
 653         cfg->fc_nlinfo.nlh = nlh;
 654         cfg->fc_nlinfo.nl_net = net;
 655
 656         if (cfg->fc_type > RTN_MAX) {
 657                 err = -EINVAL;
 658                 goto errout;
 659         }
 660
 661         nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
 662                 switch (nla_type(attr)) {
 663                 case RTA_DST:
 664                         cfg->fc_dst = nla_get_be32(attr);
 665                         break;
 666                 case RTA_OIF:
 667                         cfg->fc_oif = nla_get_u32(attr);
 668                         break;
 669                 case RTA_GATEWAY:
 670                         cfg->fc_gw = nla_get_be32(attr);
 671                         break;
 672                 case RTA_PRIORITY:
 673                         cfg->fc_priority = nla_get_u32(attr);
 674                         break;
 675                 case RTA_PREFSRC:
 676                         cfg->fc_prefsrc = nla_get_be32(attr);
 677                         break;
 678                 case RTA_METRICS:
 679                         cfg->fc_mx = nla_data(attr);
 680                         cfg->fc_mx_len = nla_len(attr);
 681                         break;
 682                 case RTA_MULTIPATH:
 683                         err = lwtunnel_valid_encap_type_attr(nla_data(attr),
 684                                                              nla_len(attr));
 685                         if (err < 0)
 686                                 goto errout;
 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                         err = lwtunnel_valid_encap_type(cfg->fc_encap_type);
 702                         if (err < 0)
 703                                 goto errout;
 704                         break;
 705                 }
 706         }
 707
 708         return 0;
 709 errout:
 710         return err;
 711 }
 712
 713 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
 714 {
 715         struct net *net = sock_net(skb->sk);
 716         struct fib_config cfg;
 717         struct fib_table *tb;
 718         int err;
 719
 720         err = rtm_to_fib_config(net, skb, nlh, &cfg);
 721         if (err < 0)
 722                 goto errout;
 723
 724         tb = fib_get_table(net, cfg.fc_table);
 725         if (!tb) {
 726                 err = -ESRCH;
 727                 goto errout;
 728         }
 729
 730         err = fib_table_delete(net, tb, &cfg);
 731 errout:
 732         return err;
 733 }
 734
 735 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
 736 {
 737         struct net *net = sock_net(skb->sk);
 738         struct fib_config cfg;
 739         struct fib_table *tb;
 740         int err;
 741
 742         err = rtm_to_fib_config(net, skb, nlh, &cfg);
 743         if (err < 0)
 744                 goto errout;
 745
 746         tb = fib_new_table(net, cfg.fc_table);
 747         if (!tb) {
 748                 err = -ENOBUFS;
 749                 goto errout;
 750         }
 751
 752         err = fib_table_insert(net, tb, &cfg);
 753 errout:
 754         return err;
 755 }
 756
 757 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 758 {
 759         struct net *net = sock_net(skb->sk);
 760         unsigned int h, s_h;
 761         unsigned int e = 0, s_e;
 762         struct fib_table *tb;
 763         struct hlist_head *head;
 764         int dumped = 0;
 765
 766         if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
 767             ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
 768                 return skb->len;
 769
 770         s_h = cb->args[0];
 771         s_e = cb->args[1];
 772
 773         rcu_read_lock();
 774
 775         for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
 776                 e = 0;
 777                 head = &net->ipv4.fib_table_hash[h];
 778                 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
 779                         if (e < s_e)
 780                                 goto next;
 781                         if (dumped)
 782                                 memset(&cb->args[2], 0, sizeof(cb->args) -
 783                                                  2 * sizeof(cb->args[0]));
 784                         if (fib_table_dump(tb, skb, cb) < 0)
 785                                 goto out;
 786                         dumped = 1;
 787 next:
 788                         e++;
 789                 }
 790         }
 791 out:
 792         rcu_read_unlock();
 793
 794         cb->args[1] = e;
 795         cb->args[0] = h;
 796
 797         return skb->len;
 798 }
 799
 800 /* Prepare and feed intra-kernel routing request.
 801  * Really, it should be netlink message, but :-( netlink
 802  * can be not configured, so that we feed it directly
 803  * to fib engine. It is legal, because all events occur
 804  * only when netlink is already locked.
 805  */
 806 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
 807 {
 808         struct net *net = dev_net(ifa->ifa_dev->dev);
 809         u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
 810         struct fib_table *tb;
 811         struct fib_config cfg = {
 812                 .fc_protocol = RTPROT_KERNEL,
 813                 .fc_type = type,
 814                 .fc_dst = dst,
 815                 .fc_dst_len = dst_len,
 816                 .fc_prefsrc = ifa->ifa_local,
 817                 .fc_oif = ifa->ifa_dev->dev->ifindex,
 818                 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
 819                 .fc_nlinfo = {
 820                         .nl_net = net,
 821                 },
 822         };
 823
 824         if (!tb_id)
 825                 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
 826
 827         tb = fib_new_table(net, tb_id);
 828         if (!tb)
 829                 return;
 830
 831         cfg.fc_table = tb->tb_id;
 832
 833         if (type != RTN_LOCAL)
 834                 cfg.fc_scope = RT_SCOPE_LINK;
 835         else
 836                 cfg.fc_scope = RT_SCOPE_HOST;
 837
 838         if (cmd == RTM_NEWROUTE)
 839                 fib_table_insert(net, tb, &cfg);
 840         else
 841                 fib_table_delete(net, tb, &cfg);
 842 }
 843
 844 void fib_add_ifaddr(struct in_ifaddr *ifa)
 845 {
 846         struct in_device *in_dev = ifa->ifa_dev;
 847         struct net_device *dev = in_dev->dev;
 848         struct in_ifaddr *prim = ifa;
 849         __be32 mask = ifa->ifa_mask;
 850         __be32 addr = ifa->ifa_local;
 851         __be32 prefix = ifa->ifa_address & mask;
 852
 853         if (ifa->ifa_flags & IFA_F_SECONDARY) {
 854                 prim = inet_ifa_byprefix(in_dev, prefix, mask);
 855                 if (!prim) {
 856                         pr_warn("%s: bug: prim == NULL\n", __func__);
 857                         return;
 858                 }
 859         }
 860
 861         fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
 862
 863         if (!(dev->flags & IFF_UP))
 864                 return;
 865
 866         /* Add broadcast address, if it is explicitly assigned. */
 867         if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
 868                 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
 869
 870         if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
 871             (prefix != addr || ifa->ifa_prefixlen < 32)) {
 872                 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
 873                         fib_magic(RTM_NEWROUTE,
 874                                   dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
 875                                   prefix, ifa->ifa_prefixlen, prim);
 876
 877                 /* Add network specific broadcasts, when it takes a sense */
 878                 if (ifa->ifa_prefixlen < 31) {
 879                         fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
 880                         fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
 881                                   32, prim);
 882                 }
 883         }
 884 }
 885
 886 /* Delete primary or secondary address.
 887  * Optionally, on secondary address promotion consider the addresses
 888  * from subnet iprim as deleted, even if they are in device list.
 889  * In this case the secondary ifa can be in device list.
 890  */
 891 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
 892 {
 893         struct in_device *in_dev = ifa->ifa_dev;
 894         struct net_device *dev = in_dev->dev;
 895         struct in_ifaddr *ifa1;
 896         struct in_ifaddr *prim = ifa, *prim1 = NULL;
 897         __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
 898         __be32 any = ifa->ifa_address & ifa->ifa_mask;
 899 #define LOCAL_OK        1
 900 #define BRD_OK          2
 901 #define BRD0_OK         4
 902 #define BRD1_OK         8
 903         unsigned int ok = 0;
 904         int subnet = 0;         /* Primary network */
 905         int gone = 1;           /* Address is missing */
 906         int same_prefsrc = 0;   /* Another primary with same IP */
 907
 908         if (ifa->ifa_flags & IFA_F_SECONDARY) {
 909                 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
 910                 if (!prim) {
 911                         /* if the device has been deleted, we don't perform
 912                          * address promotion
 913                          */
 914                         if (!in_dev->dead)
 915                                 pr_warn("%s: bug: prim == NULL\n", __func__);
 916                         return;
 917                 }
 918                 if (iprim && iprim != prim) {
 919                         pr_warn("%s: bug: iprim != prim\n", __func__);
 920                         return;
 921                 }
 922         } else if (!ipv4_is_zeronet(any) &&
 923                    (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
 924                 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
 925                         fib_magic(RTM_DELROUTE,
 926                                   dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
 927                                   any, ifa->ifa_prefixlen, prim);
 928                 subnet = 1;
 929         }
 930
 931         if (in_dev->dead)
 932                 goto no_promotions;
 933
 934         /* Deletion is more complicated than add.
 935          * We should take care of not to delete too much :-)
 936          *
 937          * Scan address list to be sure that addresses are really gone.
 938          */
 939
 940         for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
 941                 if (ifa1 == ifa) {
 942                         /* promotion, keep the IP */
 943                         gone = 0;
 944                         continue;
 945                 }
 946                 /* Ignore IFAs from our subnet */
 947                 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
 948                     inet_ifa_match(ifa1->ifa_address, iprim))
 949                         continue;
 950
 951                 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
 952                 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
 953                         /* Another address from our subnet? */
 954                         if (ifa1->ifa_mask == prim->ifa_mask &&
 955                             inet_ifa_match(ifa1->ifa_address, prim))
 956                                 prim1 = prim;
 957                         else {
 958                                 /* We reached the secondaries, so
 959                                  * same_prefsrc should be determined.
 960                                  */
 961                                 if (!same_prefsrc)
 962                                         continue;
 963                                 /* Search new prim1 if ifa1 is not
 964                                  * using the current prim1
 965                                  */
 966                                 if (!prim1 ||
 967                                     ifa1->ifa_mask != prim1->ifa_mask ||
 968                                     !inet_ifa_match(ifa1->ifa_address, prim1))
 969                                         prim1 = inet_ifa_byprefix(in_dev,
 970                                                         ifa1->ifa_address,
 971                                                         ifa1->ifa_mask);
 972                                 if (!prim1)
 973                                         continue;
 974                                 if (prim1->ifa_local != prim->ifa_local)
 975                                         continue;
 976                         }
 977                 } else {
 978                         if (prim->ifa_local != ifa1->ifa_local)
 979                                 continue;
 980                         prim1 = ifa1;
 981                         if (prim != prim1)
 982                                 same_prefsrc = 1;
 983                 }
 984                 if (ifa->ifa_local == ifa1->ifa_local)
 985                         ok |= LOCAL_OK;
 986                 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
 987                         ok |= BRD_OK;
 988                 if (brd == ifa1->ifa_broadcast)
 989                         ok |= BRD1_OK;
 990                 if (any == ifa1->ifa_broadcast)
 991                         ok |= BRD0_OK;
 992                 /* primary has network specific broadcasts */
 993                 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
 994                         __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
 995                         __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
 996
 997                         if (!ipv4_is_zeronet(any1)) {
 998                                 if (ifa->ifa_broadcast == brd1 ||
 999                                     ifa->ifa_broadcast == any1)
1000                                         ok |= BRD_OK;
1001                                 if (brd == brd1 || brd == any1)
1002                                         ok |= BRD1_OK;
1003                                 if (any == brd1 || any == any1)
1004                                         ok |= BRD0_OK;
1005                         }
1006                 }
1007         }
1008
1009 no_promotions:
1010         if (!(ok & BRD_OK))
1011                 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
1012         if (subnet && ifa->ifa_prefixlen < 31) {
1013                 if (!(ok & BRD1_OK))
1014                         fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
1015                 if (!(ok & BRD0_OK))
1016                         fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
1017         }
1018         if (!(ok & LOCAL_OK)) {
1019                 unsigned int addr_type;
1020
1021                 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
1022
1023                 /* Check, that this local address finally disappeared. */
1024                 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1025                                                      ifa->ifa_local);
1026                 if (gone && addr_type != RTN_LOCAL) {
1027                         /* And the last, but not the least thing.
1028                          * We must flush stray FIB entries.
1029                          *
1030                          * First of all, we scan fib_info list searching
1031                          * for stray nexthop entries, then ignite fib_flush.
1032                          */
1033                         if (fib_sync_down_addr(dev, ifa->ifa_local))
1034                                 fib_flush(dev_net(dev));
1035                 }
1036         }
1037 #undef LOCAL_OK
1038 #undef BRD_OK
1039 #undef BRD0_OK
1040 #undef BRD1_OK
1041 }
1042
1043 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1044 {
1045
1046         struct fib_result       res;
1047         struct flowi4           fl4 = {
1048                 .flowi4_mark = frn->fl_mark,
1049                 .daddr = frn->fl_addr,
1050                 .flowi4_tos = frn->fl_tos,
1051                 .flowi4_scope = frn->fl_scope,
1052         };
1053         struct fib_table *tb;
1054
1055         rcu_read_lock();
1056
1057         tb = fib_get_table(net, frn->tb_id_in);
1058
1059         frn->err = -ENOENT;
1060         if (tb) {
1061                 local_bh_disable();
1062
1063                 frn->tb_id = tb->tb_id;
1064                 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1065
1066                 if (!frn->err) {
1067                         frn->prefixlen = res.prefixlen;
1068                         frn->nh_sel = res.nh_sel;
1069                         frn->type = res.type;
1070                         frn->scope = res.scope;
1071                 }
1072                 local_bh_enable();
1073         }
1074
1075         rcu_read_unlock();
1076 }
1077
1078 static void nl_fib_input(struct sk_buff *skb)
1079 {
1080         struct net *net;
1081         struct fib_result_nl *frn;
1082         struct nlmsghdr *nlh;
1083         u32 portid;
1084
1085         net = sock_net(skb->sk);
1086         nlh = nlmsg_hdr(skb);
1087         if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1088             skb->len < nlh->nlmsg_len ||
1089             nlmsg_len(nlh) < sizeof(*frn))
1090                 return;
1091
1092         skb = netlink_skb_clone(skb, GFP_KERNEL);
1093         if (!skb)
1094                 return;
1095         nlh = nlmsg_hdr(skb);
1096
1097         frn = (struct fib_result_nl *) nlmsg_data(nlh);
1098         nl_fib_lookup(net, frn);
1099
1100         portid = NETLINK_CB(skb).portid;      /* netlink portid */
1101         NETLINK_CB(skb).portid = 0;        /* from kernel */
1102         NETLINK_CB(skb).dst_group = 0;  /* unicast */
1103         netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1104 }
1105
1106 static int __net_init nl_fib_lookup_init(struct net *net)
1107 {
1108         struct sock *sk;
1109         struct netlink_kernel_cfg cfg = {
1110                 .input  = nl_fib_input,
1111         };
1112
1113         sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1114         if (!sk)
1115                 return -EAFNOSUPPORT;
1116         net->ipv4.fibnl = sk;
1117         return 0;
1118 }
1119
1120 static void nl_fib_lookup_exit(struct net *net)
1121 {
1122         netlink_kernel_release(net->ipv4.fibnl);
1123         net->ipv4.fibnl = NULL;
1124 }
1125
1126 static void fib_disable_ip(struct net_device *dev, unsigned long event,
1127                            bool force)
1128 {
1129         if (fib_sync_down_dev(dev, event, force))
1130                 fib_flush(dev_net(dev));
1131         rt_cache_flush(dev_net(dev));
1132         arp_ifdown(dev);
1133 }
1134
1135 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1136 {
1137         struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1138         struct net_device *dev = ifa->ifa_dev->dev;
1139         struct net *net = dev_net(dev);
1140
1141         switch (event) {
1142         case NETDEV_UP:
1143                 fib_add_ifaddr(ifa);
1144 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1145                 fib_sync_up(dev, RTNH_F_DEAD);
1146 #endif
1147                 atomic_inc(&net->ipv4.dev_addr_genid);
1148                 rt_cache_flush(dev_net(dev));
1149                 break;
1150         case NETDEV_DOWN:
1151                 fib_del_ifaddr(ifa, NULL);
1152                 atomic_inc(&net->ipv4.dev_addr_genid);
1153                 if (!ifa->ifa_dev->ifa_list) {
1154                         /* Last address was deleted from this interface.
1155                          * Disable IP.
1156                          */
1157                         fib_disable_ip(dev, event, true);
1158                 } else {
1159                         rt_cache_flush(dev_net(dev));
1160                 }
1161                 break;
1162         }
1163         return NOTIFY_DONE;
1164 }
1165
1166 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1167 {
1168         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1169         struct netdev_notifier_changeupper_info *info;
1170         struct in_device *in_dev;
1171         struct net *net = dev_net(dev);
1172         unsigned int flags;
1173
1174         if (event == NETDEV_UNREGISTER) {
1175                 fib_disable_ip(dev, event, true);
1176                 rt_flush_dev(dev);
1177                 return NOTIFY_DONE;
1178         }
1179
1180         in_dev = __in_dev_get_rtnl(dev);
1181         if (!in_dev)
1182                 return NOTIFY_DONE;
1183
1184         switch (event) {
1185         case NETDEV_UP:
1186                 for_ifa(in_dev) {
1187                         fib_add_ifaddr(ifa);
1188                 } endfor_ifa(in_dev);
1189 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1190                 fib_sync_up(dev, RTNH_F_DEAD);
1191 #endif
1192                 atomic_inc(&net->ipv4.dev_addr_genid);
1193                 rt_cache_flush(net);
1194                 break;
1195         case NETDEV_DOWN:
1196                 fib_disable_ip(dev, event, false);
1197                 break;
1198         case NETDEV_CHANGE:
1199                 flags = dev_get_flags(dev);
1200                 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1201                         fib_sync_up(dev, RTNH_F_LINKDOWN);
1202                 else
1203                         fib_sync_down_dev(dev, event, false);
1204                 /* fall through */
1205         case NETDEV_CHANGEMTU:
1206                 rt_cache_flush(net);
1207                 break;
1208         case NETDEV_CHANGEUPPER:
1209                 info = ptr;
1210                 /* flush all routes if dev is linked to or unlinked from
1211                  * an L3 master device (e.g., VRF)
1212                  */
1213                 if (info->upper_dev && netif_is_l3_master(info->upper_dev))
1214                         fib_disable_ip(dev, NETDEV_DOWN, true);
1215                 break;
1216         }
1217         return NOTIFY_DONE;
1218 }
1219
1220 static struct notifier_block fib_inetaddr_notifier = {
1221         .notifier_call = fib_inetaddr_event,
1222 };
1223
1224 static struct notifier_block fib_netdev_notifier = {
1225         .notifier_call = fib_netdev_event,
1226 };
1227
1228 static int __net_init ip_fib_net_init(struct net *net)
1229 {
1230         int err;
1231         size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1232
1233         net->ipv4.fib_seq = 0;
1234
1235         /* Avoid false sharing : Use at least a full cache line */
1236         size = max_t(size_t, size, L1_CACHE_BYTES);
1237
1238         net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1239         if (!net->ipv4.fib_table_hash)
1240                 return -ENOMEM;
1241
1242         err = fib4_rules_init(net);
1243         if (err < 0)
1244                 goto fail;
1245         return 0;
1246
1247 fail:
1248         kfree(net->ipv4.fib_table_hash);
1249         return err;
1250 }
1251
1252 static void ip_fib_net_exit(struct net *net)
1253 {
1254         unsigned int i;
1255
1256         rtnl_lock();
1257 #ifdef CONFIG_IP_MULTIPLE_TABLES
1258         RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1259         RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1260 #endif
1261         for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1262                 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1263                 struct hlist_node *tmp;
1264                 struct fib_table *tb;
1265
1266                 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1267                         hlist_del(&tb->tb_hlist);
1268                         fib_table_flush(net, tb);
1269                         fib_free_table(tb);
1270                 }
1271         }
1272
1273 #ifdef CONFIG_IP_MULTIPLE_TABLES
1274         fib4_rules_exit(net);
1275 #endif
1276         rtnl_unlock();
1277         kfree(net->ipv4.fib_table_hash);
1278 }
1279
1280 static int __net_init fib_net_init(struct net *net)
1281 {
1282         int error;
1283
1284 #ifdef CONFIG_IP_ROUTE_CLASSID
1285         net->ipv4.fib_num_tclassid_users = 0;
1286 #endif
1287         error = ip_fib_net_init(net);
1288         if (error < 0)
1289                 goto out;
1290         error = nl_fib_lookup_init(net);
1291         if (error < 0)
1292                 goto out_nlfl;
1293         error = fib_proc_init(net);
1294         if (error < 0)
1295                 goto out_proc;
1296 out:
1297         return error;
1298
1299 out_proc:
1300         nl_fib_lookup_exit(net);
1301 out_nlfl:
1302         ip_fib_net_exit(net);
1303         goto out;
1304 }
1305
1306 static void __net_exit fib_net_exit(struct net *net)
1307 {
1308         fib_proc_exit(net);
1309         nl_fib_lookup_exit(net);
1310         ip_fib_net_exit(net);
1311 }
1312
1313 static struct pernet_operations fib_net_ops = {
1314         .init = fib_net_init,
1315         .exit = fib_net_exit,
1316 };
1317
1318 void __init ip_fib_init(void)
1319 {
1320         rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1321         rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1322         rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1323
1324         register_pernet_subsys(&fib_net_ops);
1325         register_netdevice_notifier(&fib_netdev_notifier);
1326         register_inetaddr_notifier(&fib_inetaddr_notifier);
1327
1328         fib_trie_init();
1329 }