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         if (err < 0)
 637                 goto errout;
 638
 639         memset(cfg, 0, sizeof(*cfg));
 640
 641         rtm = nlmsg_data(nlh);
 642         cfg->fc_dst_len = rtm->rtm_dst_len;
 643         cfg->fc_tos = rtm->rtm_tos;
 644         cfg->fc_table = rtm->rtm_table;
 645         cfg->fc_protocol = rtm->rtm_protocol;
 646         cfg->fc_scope = rtm->rtm_scope;
 647         cfg->fc_type = rtm->rtm_type;
 648         cfg->fc_flags = rtm->rtm_flags;
 649         cfg->fc_nlflags = nlh->nlmsg_flags;
 650
 651         cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
 652         cfg->fc_nlinfo.nlh = nlh;
 653         cfg->fc_nlinfo.nl_net = net;
 654
 655         if (cfg->fc_type > RTN_MAX) {
 656                 err = -EINVAL;
 657                 goto errout;
 658         }
 659
 660         nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
 661                 switch (nla_type(attr)) {
 662                 case RTA_DST:
 663                         cfg->fc_dst = nla_get_be32(attr);
 664                         break;
 665                 case RTA_OIF:
 666                         cfg->fc_oif = nla_get_u32(attr);
 667                         break;
 668                 case RTA_GATEWAY:
 669                         cfg->fc_gw = nla_get_be32(attr);
 670                         break;
 671                 case RTA_PRIORITY:
 672                         cfg->fc_priority = nla_get_u32(attr);
 673                         break;
 674                 case RTA_PREFSRC:
 675                         cfg->fc_prefsrc = nla_get_be32(attr);
 676                         break;
 677                 case RTA_METRICS:
 678                         cfg->fc_mx = nla_data(attr);
 679                         cfg->fc_mx_len = nla_len(attr);
 680                         break;
 681                 case RTA_MULTIPATH:
 682                         err = lwtunnel_valid_encap_type_attr(nla_data(attr),
 683                                                              nla_len(attr));
 684                         if (err < 0)
 685                                 goto errout;
 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                         err = lwtunnel_valid_encap_type(cfg->fc_encap_type);
 701                         if (err < 0)
 702                                 goto errout;
 703                         break;
 704                 }
 705         }
 706
 707         return 0;
 708 errout:
 709         return err;
 710 }
 711
 712 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
 713 {
 714         struct net *net = sock_net(skb->sk);
 715         struct fib_config cfg;
 716         struct fib_table *tb;
 717         int err;
 718
 719         err = rtm_to_fib_config(net, skb, nlh, &cfg);
 720         if (err < 0)
 721                 goto errout;
 722
 723         tb = fib_get_table(net, cfg.fc_table);
 724         if (!tb) {
 725                 err = -ESRCH;
 726                 goto errout;
 727         }
 728
 729         err = fib_table_delete(net, tb, &cfg);
 730 errout:
 731         return err;
 732 }
 733
 734 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
 735 {
 736         struct net *net = sock_net(skb->sk);
 737         struct fib_config cfg;
 738         struct fib_table *tb;
 739         int err;
 740
 741         err = rtm_to_fib_config(net, skb, nlh, &cfg);
 742         if (err < 0)
 743                 goto errout;
 744
 745         tb = fib_new_table(net, cfg.fc_table);
 746         if (!tb) {
 747                 err = -ENOBUFS;
 748                 goto errout;
 749         }
 750
 751         err = fib_table_insert(net, tb, &cfg);
 752 errout:
 753         return err;
 754 }
 755
 756 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 757 {
 758         struct net *net = sock_net(skb->sk);
 759         unsigned int h, s_h;
 760         unsigned int e = 0, s_e;
 761         struct fib_table *tb;
 762         struct hlist_head *head;
 763         int dumped = 0;
 764
 765         if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
 766             ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
 767                 return skb->len;
 768
 769         s_h = cb->args[0];
 770         s_e = cb->args[1];
 771
 772         rcu_read_lock();
 773
 774         for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
 775                 e = 0;
 776                 head = &net->ipv4.fib_table_hash[h];
 777                 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
 778                         if (e < s_e)
 779                                 goto next;
 780                         if (dumped)
 781                                 memset(&cb->args[2], 0, sizeof(cb->args) -
 782                                                  2 * sizeof(cb->args[0]));
 783                         if (fib_table_dump(tb, skb, cb) < 0)
 784                                 goto out;
 785                         dumped = 1;
 786 next:
 787                         e++;
 788                 }
 789         }
 790 out:
 791         rcu_read_unlock();
 792
 793         cb->args[1] = e;
 794         cb->args[0] = h;
 795
 796         return skb->len;
 797 }
 798
 799 /* Prepare and feed intra-kernel routing request.
 800  * Really, it should be netlink message, but :-( netlink
 801  * can be not configured, so that we feed it directly
 802  * to fib engine. It is legal, because all events occur
 803  * only when netlink is already locked.
 804  */
 805 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
 806 {
 807         struct net *net = dev_net(ifa->ifa_dev->dev);
 808         u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
 809         struct fib_table *tb;
 810         struct fib_config cfg = {
 811                 .fc_protocol = RTPROT_KERNEL,
 812                 .fc_type = type,
 813                 .fc_dst = dst,
 814                 .fc_dst_len = dst_len,
 815                 .fc_prefsrc = ifa->ifa_local,
 816                 .fc_oif = ifa->ifa_dev->dev->ifindex,
 817                 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
 818                 .fc_nlinfo = {
 819                         .nl_net = net,
 820                 },
 821         };
 822
 823         if (!tb_id)
 824                 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
 825
 826         tb = fib_new_table(net, tb_id);
 827         if (!tb)
 828                 return;
 829
 830         cfg.fc_table = tb->tb_id;
 831
 832         if (type != RTN_LOCAL)
 833                 cfg.fc_scope = RT_SCOPE_LINK;
 834         else
 835                 cfg.fc_scope = RT_SCOPE_HOST;
 836
 837         if (cmd == RTM_NEWROUTE)
 838                 fib_table_insert(net, tb, &cfg);
 839         else
 840                 fib_table_delete(net, tb, &cfg);
 841 }
 842
 843 void fib_add_ifaddr(struct in_ifaddr *ifa)
 844 {
 845         struct in_device *in_dev = ifa->ifa_dev;
 846         struct net_device *dev = in_dev->dev;
 847         struct in_ifaddr *prim = ifa;
 848         __be32 mask = ifa->ifa_mask;
 849         __be32 addr = ifa->ifa_local;
 850         __be32 prefix = ifa->ifa_address & mask;
 851
 852         if (ifa->ifa_flags & IFA_F_SECONDARY) {
 853                 prim = inet_ifa_byprefix(in_dev, prefix, mask);
 854                 if (!prim) {
 855                         pr_warn("%s: bug: prim == NULL\n", __func__);
 856                         return;
 857                 }
 858         }
 859
 860         fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
 861
 862         if (!(dev->flags & IFF_UP))
 863                 return;
 864
 865         /* Add broadcast address, if it is explicitly assigned. */
 866         if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
 867                 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
 868
 869         if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
 870             (prefix != addr || ifa->ifa_prefixlen < 32)) {
 871                 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
 872                         fib_magic(RTM_NEWROUTE,
 873                                   dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
 874                                   prefix, ifa->ifa_prefixlen, prim);
 875
 876                 /* Add network specific broadcasts, when it takes a sense */
 877                 if (ifa->ifa_prefixlen < 31) {
 878                         fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
 879                         fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
 880                                   32, prim);
 881                 }
 882         }
 883 }
 884
 885 /* Delete primary or secondary address.
 886  * Optionally, on secondary address promotion consider the addresses
 887  * from subnet iprim as deleted, even if they are in device list.
 888  * In this case the secondary ifa can be in device list.
 889  */
 890 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
 891 {
 892         struct in_device *in_dev = ifa->ifa_dev;
 893         struct net_device *dev = in_dev->dev;
 894         struct in_ifaddr *ifa1;
 895         struct in_ifaddr *prim = ifa, *prim1 = NULL;
 896         __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
 897         __be32 any = ifa->ifa_address & ifa->ifa_mask;
 898 #define LOCAL_OK        1
 899 #define BRD_OK          2
 900 #define BRD0_OK         4
 901 #define BRD1_OK         8
 902         unsigned int ok = 0;
 903         int subnet = 0;         /* Primary network */
 904         int gone = 1;           /* Address is missing */
 905         int same_prefsrc = 0;   /* Another primary with same IP */
 906
 907         if (ifa->ifa_flags & IFA_F_SECONDARY) {
 908                 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
 909                 if (!prim) {
 910                         /* if the device has been deleted, we don't perform
 911                          * address promotion
 912                          */
 913                         if (!in_dev->dead)
 914                                 pr_warn("%s: bug: prim == NULL\n", __func__);
 915                         return;
 916                 }
 917                 if (iprim && iprim != prim) {
 918                         pr_warn("%s: bug: iprim != prim\n", __func__);
 919                         return;
 920                 }
 921         } else if (!ipv4_is_zeronet(any) &&
 922                    (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
 923                 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
 924                         fib_magic(RTM_DELROUTE,
 925                                   dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
 926                                   any, ifa->ifa_prefixlen, prim);
 927                 subnet = 1;
 928         }
 929
 930         if (in_dev->dead)
 931                 goto no_promotions;
 932
 933         /* Deletion is more complicated than add.
 934          * We should take care of not to delete too much :-)
 935          *
 936          * Scan address list to be sure that addresses are really gone.
 937          */
 938
 939         for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
 940                 if (ifa1 == ifa) {
 941                         /* promotion, keep the IP */
 942                         gone = 0;
 943                         continue;
 944                 }
 945                 /* Ignore IFAs from our subnet */
 946                 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
 947                     inet_ifa_match(ifa1->ifa_address, iprim))
 948                         continue;
 949
 950                 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
 951                 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
 952                         /* Another address from our subnet? */
 953                         if (ifa1->ifa_mask == prim->ifa_mask &&
 954                             inet_ifa_match(ifa1->ifa_address, prim))
 955                                 prim1 = prim;
 956                         else {
 957                                 /* We reached the secondaries, so
 958                                  * same_prefsrc should be determined.
 959                                  */
 960                                 if (!same_prefsrc)
 961                                         continue;
 962                                 /* Search new prim1 if ifa1 is not
 963                                  * using the current prim1
 964                                  */
 965                                 if (!prim1 ||
 966                                     ifa1->ifa_mask != prim1->ifa_mask ||
 967                                     !inet_ifa_match(ifa1->ifa_address, prim1))
 968                                         prim1 = inet_ifa_byprefix(in_dev,
 969                                                         ifa1->ifa_address,
 970                                                         ifa1->ifa_mask);
 971                                 if (!prim1)
 972                                         continue;
 973                                 if (prim1->ifa_local != prim->ifa_local)
 974                                         continue;
 975                         }
 976                 } else {
 977                         if (prim->ifa_local != ifa1->ifa_local)
 978                                 continue;
 979                         prim1 = ifa1;
 980                         if (prim != prim1)
 981                                 same_prefsrc = 1;
 982                 }
 983                 if (ifa->ifa_local == ifa1->ifa_local)
 984                         ok |= LOCAL_OK;
 985                 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
 986                         ok |= BRD_OK;
 987                 if (brd == ifa1->ifa_broadcast)
 988                         ok |= BRD1_OK;
 989                 if (any == ifa1->ifa_broadcast)
 990                         ok |= BRD0_OK;
 991                 /* primary has network specific broadcasts */
 992                 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
 993                         __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
 994                         __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
 995
 996                         if (!ipv4_is_zeronet(any1)) {
 997                                 if (ifa->ifa_broadcast == brd1 ||
 998                                     ifa->ifa_broadcast == any1)
 999                                         ok |= BRD_OK;
1000                                 if (brd == brd1 || brd == any1)
1001                                         ok |= BRD1_OK;
1002                                 if (any == brd1 || any == any1)
1003                                         ok |= BRD0_OK;
1004                         }
1005                 }
1006         }
1007
1008 no_promotions:
1009         if (!(ok & BRD_OK))
1010                 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
1011         if (subnet && ifa->ifa_prefixlen < 31) {
1012                 if (!(ok & BRD1_OK))
1013                         fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
1014                 if (!(ok & BRD0_OK))
1015                         fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
1016         }
1017         if (!(ok & LOCAL_OK)) {
1018                 unsigned int addr_type;
1019
1020                 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
1021
1022                 /* Check, that this local address finally disappeared. */
1023                 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1024                                                      ifa->ifa_local);
1025                 if (gone && addr_type != RTN_LOCAL) {
1026                         /* And the last, but not the least thing.
1027                          * We must flush stray FIB entries.
1028                          *
1029                          * First of all, we scan fib_info list searching
1030                          * for stray nexthop entries, then ignite fib_flush.
1031                          */
1032                         if (fib_sync_down_addr(dev, ifa->ifa_local))
1033                                 fib_flush(dev_net(dev));
1034                 }
1035         }
1036 #undef LOCAL_OK
1037 #undef BRD_OK
1038 #undef BRD0_OK
1039 #undef BRD1_OK
1040 }
1041
1042 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1043 {
1044
1045         struct fib_result       res;
1046         struct flowi4           fl4 = {
1047                 .flowi4_mark = frn->fl_mark,
1048                 .daddr = frn->fl_addr,
1049                 .flowi4_tos = frn->fl_tos,
1050                 .flowi4_scope = frn->fl_scope,
1051         };
1052         struct fib_table *tb;
1053
1054         rcu_read_lock();
1055
1056         tb = fib_get_table(net, frn->tb_id_in);
1057
1058         frn->err = -ENOENT;
1059         if (tb) {
1060                 local_bh_disable();
1061
1062                 frn->tb_id = tb->tb_id;
1063                 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1064
1065                 if (!frn->err) {
1066                         frn->prefixlen = res.prefixlen;
1067                         frn->nh_sel = res.nh_sel;
1068                         frn->type = res.type;
1069                         frn->scope = res.scope;
1070                 }
1071                 local_bh_enable();
1072         }
1073
1074         rcu_read_unlock();
1075 }
1076
1077 static void nl_fib_input(struct sk_buff *skb)
1078 {
1079         struct net *net;
1080         struct fib_result_nl *frn;
1081         struct nlmsghdr *nlh;
1082         u32 portid;
1083
1084         net = sock_net(skb->sk);
1085         nlh = nlmsg_hdr(skb);
1086         if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1087             skb->len < nlh->nlmsg_len ||
1088             nlmsg_len(nlh) < sizeof(*frn))
1089                 return;
1090
1091         skb = netlink_skb_clone(skb, GFP_KERNEL);
1092         if (!skb)
1093                 return;
1094         nlh = nlmsg_hdr(skb);
1095
1096         frn = (struct fib_result_nl *) nlmsg_data(nlh);
1097         nl_fib_lookup(net, frn);
1098
1099         portid = NETLINK_CB(skb).portid;      /* netlink portid */
1100         NETLINK_CB(skb).portid = 0;        /* from kernel */
1101         NETLINK_CB(skb).dst_group = 0;  /* unicast */
1102         netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1103 }
1104
1105 static int __net_init nl_fib_lookup_init(struct net *net)
1106 {
1107         struct sock *sk;
1108         struct netlink_kernel_cfg cfg = {
1109                 .input  = nl_fib_input,
1110         };
1111
1112         sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1113         if (!sk)
1114                 return -EAFNOSUPPORT;
1115         net->ipv4.fibnl = sk;
1116         return 0;
1117 }
1118
1119 static void nl_fib_lookup_exit(struct net *net)
1120 {
1121         netlink_kernel_release(net->ipv4.fibnl);
1122         net->ipv4.fibnl = NULL;
1123 }
1124
1125 static void fib_disable_ip(struct net_device *dev, unsigned long event,
1126                            bool force)
1127 {
1128         if (fib_sync_down_dev(dev, event, force))
1129                 fib_flush(dev_net(dev));
1130         rt_cache_flush(dev_net(dev));
1131         arp_ifdown(dev);
1132 }
1133
1134 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1135 {
1136         struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1137         struct net_device *dev = ifa->ifa_dev->dev;
1138         struct net *net = dev_net(dev);
1139
1140         switch (event) {
1141         case NETDEV_UP:
1142                 fib_add_ifaddr(ifa);
1143 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1144                 fib_sync_up(dev, RTNH_F_DEAD);
1145 #endif
1146                 atomic_inc(&net->ipv4.dev_addr_genid);
1147                 rt_cache_flush(dev_net(dev));
1148                 break;
1149         case NETDEV_DOWN:
1150                 fib_del_ifaddr(ifa, NULL);
1151                 atomic_inc(&net->ipv4.dev_addr_genid);
1152                 if (!ifa->ifa_dev->ifa_list) {
1153                         /* Last address was deleted from this interface.
1154                          * Disable IP.
1155                          */
1156                         fib_disable_ip(dev, event, true);
1157                 } else {
1158                         rt_cache_flush(dev_net(dev));
1159                 }
1160                 break;
1161         }
1162         return NOTIFY_DONE;
1163 }
1164
1165 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1166 {
1167         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1168         struct netdev_notifier_changeupper_info *info;
1169         struct in_device *in_dev;
1170         struct net *net = dev_net(dev);
1171         unsigned int flags;
1172
1173         if (event == NETDEV_UNREGISTER) {
1174                 fib_disable_ip(dev, event, true);
1175                 rt_flush_dev(dev);
1176                 return NOTIFY_DONE;
1177         }
1178
1179         in_dev = __in_dev_get_rtnl(dev);
1180         if (!in_dev)
1181                 return NOTIFY_DONE;
1182
1183         switch (event) {
1184         case NETDEV_UP:
1185                 for_ifa(in_dev) {
1186                         fib_add_ifaddr(ifa);
1187                 } endfor_ifa(in_dev);
1188 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1189                 fib_sync_up(dev, RTNH_F_DEAD);
1190 #endif
1191                 atomic_inc(&net->ipv4.dev_addr_genid);
1192                 rt_cache_flush(net);
1193                 break;
1194         case NETDEV_DOWN:
1195                 fib_disable_ip(dev, event, false);
1196                 break;
1197         case NETDEV_CHANGE:
1198                 flags = dev_get_flags(dev);
1199                 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1200                         fib_sync_up(dev, RTNH_F_LINKDOWN);
1201                 else
1202                         fib_sync_down_dev(dev, event, false);
1203                 /* fall through */
1204         case NETDEV_CHANGEMTU:
1205                 rt_cache_flush(net);
1206                 break;
1207         case NETDEV_CHANGEUPPER:
1208                 info = ptr;
1209                 /* flush all routes if dev is linked to or unlinked from
1210                  * an L3 master device (e.g., VRF)
1211                  */
1212                 if (info->upper_dev && netif_is_l3_master(info->upper_dev))
1213                         fib_disable_ip(dev, NETDEV_DOWN, true);
1214                 break;
1215         }
1216         return NOTIFY_DONE;
1217 }
1218
1219 static struct notifier_block fib_inetaddr_notifier = {
1220         .notifier_call = fib_inetaddr_event,
1221 };
1222
1223 static struct notifier_block fib_netdev_notifier = {
1224         .notifier_call = fib_netdev_event,
1225 };
1226
1227 static int __net_init ip_fib_net_init(struct net *net)
1228 {
1229         int err;
1230         size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1231
1232         net->ipv4.fib_seq = 0;
1233
1234         /* Avoid false sharing : Use at least a full cache line */
1235         size = max_t(size_t, size, L1_CACHE_BYTES);
1236
1237         net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1238         if (!net->ipv4.fib_table_hash)
1239                 return -ENOMEM;
1240
1241         err = fib4_rules_init(net);
1242         if (err < 0)
1243                 goto fail;
1244         return 0;
1245
1246 fail:
1247         kfree(net->ipv4.fib_table_hash);
1248         return err;
1249 }
1250
1251 static void ip_fib_net_exit(struct net *net)
1252 {
1253         unsigned int i;
1254
1255         rtnl_lock();
1256 #ifdef CONFIG_IP_MULTIPLE_TABLES
1257         RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1258         RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1259 #endif
1260         for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1261                 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1262                 struct hlist_node *tmp;
1263                 struct fib_table *tb;
1264
1265                 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1266                         hlist_del(&tb->tb_hlist);
1267                         fib_table_flush(net, tb);
1268                         fib_free_table(tb);
1269                 }
1270         }
1271
1272 #ifdef CONFIG_IP_MULTIPLE_TABLES
1273         fib4_rules_exit(net);
1274 #endif
1275         rtnl_unlock();
1276         kfree(net->ipv4.fib_table_hash);
1277 }
1278
1279 static int __net_init fib_net_init(struct net *net)
1280 {
1281         int error;
1282
1283 #ifdef CONFIG_IP_ROUTE_CLASSID
1284         net->ipv4.fib_num_tclassid_users = 0;
1285 #endif
1286         error = ip_fib_net_init(net);
1287         if (error < 0)
1288                 goto out;
1289         error = nl_fib_lookup_init(net);
1290         if (error < 0)
1291                 goto out_nlfl;
1292         error = fib_proc_init(net);
1293         if (error < 0)
1294                 goto out_proc;
1295 out:
1296         return error;
1297
1298 out_proc:
1299         nl_fib_lookup_exit(net);
1300 out_nlfl:
1301         ip_fib_net_exit(net);
1302         goto out;
1303 }
1304
1305 static void __net_exit fib_net_exit(struct net *net)
1306 {
1307         fib_proc_exit(net);
1308         nl_fib_lookup_exit(net);
1309         ip_fib_net_exit(net);
1310 }
1311
1312 static struct pernet_operations fib_net_ops = {
1313         .init = fib_net_init,
1314         .exit = fib_net_exit,
1315 };
1316
1317 void __init ip_fib_init(void)
1318 {
1319         rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1320         rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1321         rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1322
1323         register_pernet_subsys(&fib_net_ops);
1324         register_netdevice_notifier(&fib_netdev_notifier);
1325         register_inetaddr_notifier(&fib_inetaddr_notifier);
1326
1327         fib_trie_init();
1328 }