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
  77 static bool fib4_has_custom_rules(struct net *net)
  78 {
  79         return false;
  80 }
  81 #else
  82
  83 struct fib_table *fib_new_table(struct net *net, u32 id)
  84 {
  85         struct fib_table *tb, *alias = NULL;
  86         unsigned int h;
  87
  88         if (id == 0)
  89                 id = RT_TABLE_MAIN;
  90         tb = fib_get_table(net, id);
  91         if (tb)
  92                 return tb;
  93
  94         if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules)
  95                 alias = fib_new_table(net, RT_TABLE_MAIN);
  96
  97         tb = fib_trie_table(id, alias);
  98         if (!tb)
  99                 return NULL;
 100
 101         switch (id) {
 102         case RT_TABLE_MAIN:
 103                 rcu_assign_pointer(net->ipv4.fib_main, tb);
 104                 break;
 105         case RT_TABLE_DEFAULT:
 106                 rcu_assign_pointer(net->ipv4.fib_default, tb);
 107                 break;
 108         default:
 109                 break;
 110         }
 111
 112         h = id & (FIB_TABLE_HASHSZ - 1);
 113         hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
 114         return tb;
 115 }
 116 EXPORT_SYMBOL_GPL(fib_new_table);
 117
 118 /* caller must hold either rtnl or rcu read lock */
 119 struct fib_table *fib_get_table(struct net *net, u32 id)
 120 {
 121         struct fib_table *tb;
 122         struct hlist_head *head;
 123         unsigned int h;
 124
 125         if (id == 0)
 126                 id = RT_TABLE_MAIN;
 127         h = id & (FIB_TABLE_HASHSZ - 1);
 128
 129         head = &net->ipv4.fib_table_hash[h];
 130         hlist_for_each_entry_rcu(tb, head, tb_hlist) {
 131                 if (tb->tb_id == id)
 132                         return tb;
 133         }
 134         return NULL;
 135 }
 136
 137 static bool fib4_has_custom_rules(struct net *net)
 138 {
 139         return net->ipv4.fib_has_custom_rules;
 140 }
 141 #endif /* CONFIG_IP_MULTIPLE_TABLES */
 142
 143 static void fib_replace_table(struct net *net, struct fib_table *old,
 144                               struct fib_table *new)
 145 {
 146 #ifdef CONFIG_IP_MULTIPLE_TABLES
 147         switch (new->tb_id) {
 148         case RT_TABLE_MAIN:
 149                 rcu_assign_pointer(net->ipv4.fib_main, new);
 150                 break;
 151         case RT_TABLE_DEFAULT:
 152                 rcu_assign_pointer(net->ipv4.fib_default, new);
 153                 break;
 154         default:
 155                 break;
 156         }
 157
 158 #endif
 159         /* replace the old table in the hlist */
 160         hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
 161 }
 162
 163 int fib_unmerge(struct net *net)
 164 {
 165         struct fib_table *old, *new, *main_table;
 166
 167         /* attempt to fetch local table if it has been allocated */
 168         old = fib_get_table(net, RT_TABLE_LOCAL);
 169         if (!old)
 170                 return 0;
 171
 172         new = fib_trie_unmerge(old);
 173         if (!new)
 174                 return -ENOMEM;
 175
 176         /* table is already unmerged */
 177         if (new == old)
 178                 return 0;
 179
 180         /* replace merged table with clean table */
 181         fib_replace_table(net, old, new);
 182         fib_free_table(old);
 183
 184         /* attempt to fetch main table if it has been allocated */
 185         main_table = fib_get_table(net, RT_TABLE_MAIN);
 186         if (!main_table)
 187                 return 0;
 188
 189         /* flush local entries from main table */
 190         fib_table_flush_external(main_table);
 191
 192         return 0;
 193 }
 194
 195 void fib_flush(struct net *net)
 196 {
 197         int flushed = 0;
 198         unsigned int h;
 199
 200         for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
 201                 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
 202                 struct hlist_node *tmp;
 203                 struct fib_table *tb;
 204
 205                 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
 206                         flushed += fib_table_flush(net, tb, false);
 207         }
 208
 209         if (flushed)
 210                 rt_cache_flush(net);
 211 }
 212
 213 /*
 214  * Find address type as if only "dev" was present in the system. If
 215  * on_dev is NULL then all interfaces are taken into consideration.
 216  */
 217 static inline unsigned int __inet_dev_addr_type(struct net *net,
 218                                                 const struct net_device *dev,
 219                                                 __be32 addr, u32 tb_id)
 220 {
 221         struct flowi4           fl4 = { .daddr = addr };
 222         struct fib_result       res;
 223         unsigned int ret = RTN_BROADCAST;
 224         struct fib_table *table;
 225
 226         if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
 227                 return RTN_BROADCAST;
 228         if (ipv4_is_multicast(addr))
 229                 return RTN_MULTICAST;
 230
 231         rcu_read_lock();
 232
 233         table = fib_get_table(net, tb_id);
 234         if (table) {
 235                 ret = RTN_UNICAST;
 236                 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
 237                         if (!dev || dev == res.fi->fib_dev)
 238                                 ret = res.type;
 239                 }
 240         }
 241
 242         rcu_read_unlock();
 243         return ret;
 244 }
 245
 246 unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
 247 {
 248         return __inet_dev_addr_type(net, NULL, addr, tb_id);
 249 }
 250 EXPORT_SYMBOL(inet_addr_type_table);
 251
 252 unsigned int inet_addr_type(struct net *net, __be32 addr)
 253 {
 254         return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
 255 }
 256 EXPORT_SYMBOL(inet_addr_type);
 257
 258 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
 259                                 __be32 addr)
 260 {
 261         u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
 262
 263         return __inet_dev_addr_type(net, dev, addr, rt_table);
 264 }
 265 EXPORT_SYMBOL(inet_dev_addr_type);
 266
 267 /* inet_addr_type with dev == NULL but using the table from a dev
 268  * if one is associated
 269  */
 270 unsigned int inet_addr_type_dev_table(struct net *net,
 271                                       const struct net_device *dev,
 272                                       __be32 addr)
 273 {
 274         u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
 275
 276         return __inet_dev_addr_type(net, NULL, addr, rt_table);
 277 }
 278 EXPORT_SYMBOL(inet_addr_type_dev_table);
 279
 280 __be32 fib_compute_spec_dst(struct sk_buff *skb)
 281 {
 282         struct net_device *dev = skb->dev;
 283         struct in_device *in_dev;
 284         struct fib_result res;
 285         struct rtable *rt;
 286         struct net *net;
 287         int scope;
 288
 289         rt = skb_rtable(skb);
 290         if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
 291             RTCF_LOCAL)
 292                 return ip_hdr(skb)->daddr;
 293
 294         in_dev = __in_dev_get_rcu(dev);
 295
 296         net = dev_net(dev);
 297
 298         scope = RT_SCOPE_UNIVERSE;
 299         if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
 300                 bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev);
 301                 struct flowi4 fl4 = {
 302                         .flowi4_iif = LOOPBACK_IFINDEX,
 303                         .flowi4_oif = l3mdev_master_ifindex_rcu(dev),
 304                         .daddr = ip_hdr(skb)->saddr,
 305                         .flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
 306                         .flowi4_scope = scope,
 307                         .flowi4_mark = vmark ? skb->mark : 0,
 308                 };
 309                 if (!fib_lookup(net, &fl4, &res, 0))
 310                         return fib_result_prefsrc(net, &res);
 311         } else {
 312                 scope = RT_SCOPE_LINK;
 313         }
 314
 315         return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
 316 }
 317
 318 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev)
 319 {
 320         bool dev_match = false;
 321 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 322         int ret;
 323
 324         for (ret = 0; ret < fi->fib_nhs; ret++) {
 325                 struct fib_nh *nh = &fi->fib_nh[ret];
 326
 327                 if (nh->fib_nh_dev == dev) {
 328                         dev_match = true;
 329                         break;
 330                 } else if (l3mdev_master_ifindex_rcu(nh->fib_nh_dev) == dev->ifindex) {
 331                         dev_match = true;
 332                         break;
 333                 }
 334         }
 335 #else
 336         if (fi->fib_nh[0].fib_nh_dev == dev)
 337                 dev_match = true;
 338 #endif
 339
 340         return dev_match;
 341 }
 342 EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev);
 343
 344 /* Given (packet source, input interface) and optional (dst, oif, tos):
 345  * - (main) check, that source is valid i.e. not broadcast or our local
 346  *   address.
 347  * - figure out what "logical" interface this packet arrived
 348  *   and calculate "specific destination" address.
 349  * - check, that packet arrived from expected physical interface.
 350  * called with rcu_read_lock()
 351  */
 352 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 353                                  u8 tos, int oif, struct net_device *dev,
 354                                  int rpf, struct in_device *idev, u32 *itag)
 355 {
 356         struct net *net = dev_net(dev);
 357         struct flow_keys flkeys;
 358         int ret, no_addr;
 359         struct fib_result res;
 360         struct flowi4 fl4;
 361         bool dev_match;
 362
 363         fl4.flowi4_oif = 0;
 364         fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
 365         if (!fl4.flowi4_iif)
 366                 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
 367         fl4.daddr = src;
 368         fl4.saddr = dst;
 369         fl4.flowi4_tos = tos;
 370         fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
 371         fl4.flowi4_tun_key.tun_id = 0;
 372         fl4.flowi4_flags = 0;
 373         fl4.flowi4_uid = sock_net_uid(net, NULL);
 374
 375         no_addr = idev->ifa_list == NULL;
 376
 377         fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
 378         if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) {
 379                 fl4.flowi4_proto = 0;
 380                 fl4.fl4_sport = 0;
 381                 fl4.fl4_dport = 0;
 382         }
 383
 384         if (fib_lookup(net, &fl4, &res, 0))
 385                 goto last_resort;
 386         if (res.type != RTN_UNICAST &&
 387             (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
 388                 goto e_inval;
 389         fib_combine_itag(itag, &res);
 390
 391         dev_match = fib_info_nh_uses_dev(res.fi, dev);
 392         if (dev_match) {
 393                 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
 394                 return ret;
 395         }
 396         if (no_addr)
 397                 goto last_resort;
 398         if (rpf == 1)
 399                 goto e_rpf;
 400         fl4.flowi4_oif = dev->ifindex;
 401
 402         ret = 0;
 403         if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
 404                 if (res.type == RTN_UNICAST)
 405                         ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
 406         }
 407         return ret;
 408
 409 last_resort:
 410         if (rpf)
 411                 goto e_rpf;
 412         *itag = 0;
 413         return 0;
 414
 415 e_inval:
 416         return -EINVAL;
 417 e_rpf:
 418         return -EXDEV;
 419 }
 420
 421 /* Ignore rp_filter for packets protected by IPsec. */
 422 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 423                         u8 tos, int oif, struct net_device *dev,
 424                         struct in_device *idev, u32 *itag)
 425 {
 426         int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
 427         struct net *net = dev_net(dev);
 428
 429         if (!r && !fib_num_tclassid_users(net) &&
 430             (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
 431                 if (IN_DEV_ACCEPT_LOCAL(idev))
 432                         goto ok;
 433                 /* with custom local routes in place, checking local addresses
 434                  * only will be too optimistic, with custom rules, checking
 435                  * local addresses only can be too strict, e.g. due to vrf
 436                  */
 437                 if (net->ipv4.fib_has_custom_local_routes ||
 438                     fib4_has_custom_rules(net))
 439                         goto full_check;
 440                 if (inet_lookup_ifaddr_rcu(net, src))
 441                         return -EINVAL;
 442
 443 ok:
 444                 *itag = 0;
 445                 return 0;
 446         }
 447
 448 full_check:
 449         return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
 450 }
 451
 452 static inline __be32 sk_extract_addr(struct sockaddr *addr)
 453 {
 454         return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
 455 }
 456
 457 static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
 458 {
 459         struct nlattr *nla;
 460
 461         nla = (struct nlattr *) ((char *) mx + len);
 462         nla->nla_type = type;
 463         nla->nla_len = nla_attr_size(4);
 464         *(u32 *) nla_data(nla) = value;
 465
 466         return len + nla_total_size(4);
 467 }
 468
 469 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
 470                                  struct fib_config *cfg)
 471 {
 472         __be32 addr;
 473         int plen;
 474
 475         memset(cfg, 0, sizeof(*cfg));
 476         cfg->fc_nlinfo.nl_net = net;
 477
 478         if (rt->rt_dst.sa_family != AF_INET)
 479                 return -EAFNOSUPPORT;
 480
 481         /*
 482          * Check mask for validity:
 483          * a) it must be contiguous.
 484          * b) destination must have all host bits clear.
 485          * c) if application forgot to set correct family (AF_INET),
 486          *    reject request unless it is absolutely clear i.e.
 487          *    both family and mask are zero.
 488          */
 489         plen = 32;
 490         addr = sk_extract_addr(&rt->rt_dst);
 491         if (!(rt->rt_flags & RTF_HOST)) {
 492                 __be32 mask = sk_extract_addr(&rt->rt_genmask);
 493
 494                 if (rt->rt_genmask.sa_family != AF_INET) {
 495                         if (mask || rt->rt_genmask.sa_family)
 496                                 return -EAFNOSUPPORT;
 497                 }
 498
 499                 if (bad_mask(mask, addr))
 500                         return -EINVAL;
 501
 502                 plen = inet_mask_len(mask);
 503         }
 504
 505         cfg->fc_dst_len = plen;
 506         cfg->fc_dst = addr;
 507
 508         if (cmd != SIOCDELRT) {
 509                 cfg->fc_nlflags = NLM_F_CREATE;
 510                 cfg->fc_protocol = RTPROT_BOOT;
 511         }
 512
 513         if (rt->rt_metric)
 514                 cfg->fc_priority = rt->rt_metric - 1;
 515
 516         if (rt->rt_flags & RTF_REJECT) {
 517                 cfg->fc_scope = RT_SCOPE_HOST;
 518                 cfg->fc_type = RTN_UNREACHABLE;
 519                 return 0;
 520         }
 521
 522         cfg->fc_scope = RT_SCOPE_NOWHERE;
 523         cfg->fc_type = RTN_UNICAST;
 524
 525         if (rt->rt_dev) {
 526                 char *colon;
 527                 struct net_device *dev;
 528                 char devname[IFNAMSIZ];
 529
 530                 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
 531                         return -EFAULT;
 532
 533                 devname[IFNAMSIZ-1] = 0;
 534                 colon = strchr(devname, ':');
 535                 if (colon)
 536                         *colon = 0;
 537                 dev = __dev_get_by_name(net, devname);
 538                 if (!dev)
 539                         return -ENODEV;
 540                 cfg->fc_oif = dev->ifindex;
 541                 cfg->fc_table = l3mdev_fib_table(dev);
 542                 if (colon) {
 543                         struct in_ifaddr *ifa;
 544                         struct in_device *in_dev = __in_dev_get_rtnl(dev);
 545                         if (!in_dev)
 546                                 return -ENODEV;
 547                         *colon = ':';
 548                         for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
 549                                 if (strcmp(ifa->ifa_label, devname) == 0)
 550                                         break;
 551                         if (!ifa)
 552                                 return -ENODEV;
 553                         cfg->fc_prefsrc = ifa->ifa_local;
 554                 }
 555         }
 556
 557         addr = sk_extract_addr(&rt->rt_gateway);
 558         if (rt->rt_gateway.sa_family == AF_INET && addr) {
 559                 unsigned int addr_type;
 560
 561                 cfg->fc_gw4 = addr;
 562                 cfg->fc_gw_family = AF_INET;
 563                 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
 564                 if (rt->rt_flags & RTF_GATEWAY &&
 565                     addr_type == RTN_UNICAST)
 566                         cfg->fc_scope = RT_SCOPE_UNIVERSE;
 567         }
 568
 569         if (cmd == SIOCDELRT)
 570                 return 0;
 571
 572         if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family)
 573                 return -EINVAL;
 574
 575         if (cfg->fc_scope == RT_SCOPE_NOWHERE)
 576                 cfg->fc_scope = RT_SCOPE_LINK;
 577
 578         if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
 579                 struct nlattr *mx;
 580                 int len = 0;
 581
 582                 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL);
 583                 if (!mx)
 584                         return -ENOMEM;
 585
 586                 if (rt->rt_flags & RTF_MTU)
 587                         len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
 588
 589                 if (rt->rt_flags & RTF_WINDOW)
 590                         len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
 591
 592                 if (rt->rt_flags & RTF_IRTT)
 593                         len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
 594
 595                 cfg->fc_mx = mx;
 596                 cfg->fc_mx_len = len;
 597         }
 598
 599         return 0;
 600 }
 601
 602 /*
 603  * Handle IP routing ioctl calls.
 604  * These are used to manipulate the routing tables
 605  */
 606 int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
 607 {
 608         struct fib_config cfg;
 609         int err;
 610
 611         switch (cmd) {
 612         case SIOCADDRT:         /* Add a route */
 613         case SIOCDELRT:         /* Delete a route */
 614                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 615                         return -EPERM;
 616
 617                 rtnl_lock();
 618                 err = rtentry_to_fib_config(net, cmd, rt, &cfg);
 619                 if (err == 0) {
 620                         struct fib_table *tb;
 621
 622                         if (cmd == SIOCDELRT) {
 623                                 tb = fib_get_table(net, cfg.fc_table);
 624                                 if (tb)
 625                                         err = fib_table_delete(net, tb, &cfg,
 626                                                                NULL);
 627                                 else
 628                                         err = -ESRCH;
 629                         } else {
 630                                 tb = fib_new_table(net, cfg.fc_table);
 631                                 if (tb)
 632                                         err = fib_table_insert(net, tb,
 633                                                                &cfg, NULL);
 634                                 else
 635                                         err = -ENOBUFS;
 636                         }
 637
 638                         /* allocated by rtentry_to_fib_config() */
 639                         kfree(cfg.fc_mx);
 640                 }
 641                 rtnl_unlock();
 642                 return err;
 643         }
 644         return -EINVAL;
 645 }
 646
 647 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
 648         [RTA_DST]               = { .type = NLA_U32 },
 649         [RTA_SRC]               = { .type = NLA_U32 },
 650         [RTA_IIF]               = { .type = NLA_U32 },
 651         [RTA_OIF]               = { .type = NLA_U32 },
 652         [RTA_GATEWAY]           = { .type = NLA_U32 },
 653         [RTA_PRIORITY]          = { .type = NLA_U32 },
 654         [RTA_PREFSRC]           = { .type = NLA_U32 },
 655         [RTA_METRICS]           = { .type = NLA_NESTED },
 656         [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
 657         [RTA_FLOW]              = { .type = NLA_U32 },
 658         [RTA_ENCAP_TYPE]        = { .type = NLA_U16 },
 659         [RTA_ENCAP]             = { .type = NLA_NESTED },
 660         [RTA_UID]               = { .type = NLA_U32 },
 661         [RTA_MARK]              = { .type = NLA_U32 },
 662         [RTA_TABLE]             = { .type = NLA_U32 },
 663         [RTA_IP_PROTO]          = { .type = NLA_U8 },
 664         [RTA_SPORT]             = { .type = NLA_U16 },
 665         [RTA_DPORT]             = { .type = NLA_U16 },
 666 };
 667
 668 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla,
 669                     struct netlink_ext_ack *extack)
 670 {
 671         struct rtvia *via;
 672         int alen;
 673
 674         if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
 675                 NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA");
 676                 return -EINVAL;
 677         }
 678
 679         via = nla_data(nla);
 680         alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr);
 681
 682         switch (via->rtvia_family) {
 683         case AF_INET:
 684                 if (alen != sizeof(__be32)) {
 685                         NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA");
 686                         return -EINVAL;
 687                 }
 688                 cfg->fc_gw_family = AF_INET;
 689                 cfg->fc_gw4 = *((__be32 *)via->rtvia_addr);
 690                 break;
 691         case AF_INET6:
 692 #ifdef CONFIG_IPV6
 693                 if (alen != sizeof(struct in6_addr)) {
 694                         NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA");
 695                         return -EINVAL;
 696                 }
 697                 cfg->fc_gw_family = AF_INET6;
 698                 cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr);
 699 #else
 700                 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel");
 701                 return -EINVAL;
 702 #endif
 703                 break;
 704         default:
 705                 NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA");
 706                 return -EINVAL;
 707         }
 708
 709         return 0;
 710 }
 711
 712 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
 713                              struct nlmsghdr *nlh, struct fib_config *cfg,
 714                              struct netlink_ext_ack *extack)
 715 {
 716         bool has_gw = false, has_via = false;
 717         struct nlattr *attr;
 718         int err, remaining;
 719         struct rtmsg *rtm;
 720
 721         err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX,
 722                                         rtm_ipv4_policy, extack);
 723         if (err < 0)
 724                 goto errout;
 725
 726         memset(cfg, 0, sizeof(*cfg));
 727
 728         rtm = nlmsg_data(nlh);
 729         cfg->fc_dst_len = rtm->rtm_dst_len;
 730         cfg->fc_tos = rtm->rtm_tos;
 731         cfg->fc_table = rtm->rtm_table;
 732         cfg->fc_protocol = rtm->rtm_protocol;
 733         cfg->fc_scope = rtm->rtm_scope;
 734         cfg->fc_type = rtm->rtm_type;
 735         cfg->fc_flags = rtm->rtm_flags;
 736         cfg->fc_nlflags = nlh->nlmsg_flags;
 737
 738         cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
 739         cfg->fc_nlinfo.nlh = nlh;
 740         cfg->fc_nlinfo.nl_net = net;
 741
 742         if (cfg->fc_type > RTN_MAX) {
 743                 NL_SET_ERR_MSG(extack, "Invalid route type");
 744                 err = -EINVAL;
 745                 goto errout;
 746         }
 747
 748         nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
 749                 switch (nla_type(attr)) {
 750                 case RTA_DST:
 751                         cfg->fc_dst = nla_get_be32(attr);
 752                         break;
 753                 case RTA_OIF:
 754                         cfg->fc_oif = nla_get_u32(attr);
 755                         break;
 756                 case RTA_GATEWAY:
 757                         has_gw = true;
 758                         cfg->fc_gw4 = nla_get_be32(attr);
 759                         if (cfg->fc_gw4)
 760                                 cfg->fc_gw_family = AF_INET;
 761                         break;
 762                 case RTA_VIA:
 763                         has_via = true;
 764                         err = fib_gw_from_via(cfg, attr, extack);
 765                         if (err)
 766                                 goto errout;
 767                         break;
 768                 case RTA_PRIORITY:
 769                         cfg->fc_priority = nla_get_u32(attr);
 770                         break;
 771                 case RTA_PREFSRC:
 772                         cfg->fc_prefsrc = nla_get_be32(attr);
 773                         break;
 774                 case RTA_METRICS:
 775                         cfg->fc_mx = nla_data(attr);
 776                         cfg->fc_mx_len = nla_len(attr);
 777                         break;
 778                 case RTA_MULTIPATH:
 779                         err = lwtunnel_valid_encap_type_attr(nla_data(attr),
 780                                                              nla_len(attr),
 781                                                              extack);
 782                         if (err < 0)
 783                                 goto errout;
 784                         cfg->fc_mp = nla_data(attr);
 785                         cfg->fc_mp_len = nla_len(attr);
 786                         break;
 787                 case RTA_FLOW:
 788                         cfg->fc_flow = nla_get_u32(attr);
 789                         break;
 790                 case RTA_TABLE:
 791                         cfg->fc_table = nla_get_u32(attr);
 792                         break;
 793                 case RTA_ENCAP:
 794                         cfg->fc_encap = attr;
 795                         break;
 796                 case RTA_ENCAP_TYPE:
 797                         cfg->fc_encap_type = nla_get_u16(attr);
 798                         err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
 799                                                         extack);
 800                         if (err < 0)
 801                                 goto errout;
 802                         break;
 803                 }
 804         }
 805
 806         if (has_gw && has_via) {
 807                 NL_SET_ERR_MSG(extack,
 808                                "Nexthop configuration can not contain both GATEWAY and VIA");
 809                 goto errout;
 810         }
 811
 812         return 0;
 813 errout:
 814         return err;
 815 }
 816
 817 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
 818                              struct netlink_ext_ack *extack)
 819 {
 820         struct net *net = sock_net(skb->sk);
 821         struct fib_config cfg;
 822         struct fib_table *tb;
 823         int err;
 824
 825         err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
 826         if (err < 0)
 827                 goto errout;
 828
 829         tb = fib_get_table(net, cfg.fc_table);
 830         if (!tb) {
 831                 NL_SET_ERR_MSG(extack, "FIB table does not exist");
 832                 err = -ESRCH;
 833                 goto errout;
 834         }
 835
 836         err = fib_table_delete(net, tb, &cfg, extack);
 837 errout:
 838         return err;
 839 }
 840
 841 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
 842                              struct netlink_ext_ack *extack)
 843 {
 844         struct net *net = sock_net(skb->sk);
 845         struct fib_config cfg;
 846         struct fib_table *tb;
 847         int err;
 848
 849         err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
 850         if (err < 0)
 851                 goto errout;
 852
 853         tb = fib_new_table(net, cfg.fc_table);
 854         if (!tb) {
 855                 err = -ENOBUFS;
 856                 goto errout;
 857         }
 858
 859         err = fib_table_insert(net, tb, &cfg, extack);
 860         if (!err && cfg.fc_type == RTN_LOCAL)
 861                 net->ipv4.fib_has_custom_local_routes = true;
 862 errout:
 863         return err;
 864 }
 865
 866 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
 867                           struct fib_dump_filter *filter,
 868                           struct netlink_callback *cb)
 869 {
 870         struct netlink_ext_ack *extack = cb->extack;
 871         struct nlattr *tb[RTA_MAX + 1];
 872         struct rtmsg *rtm;
 873         int err, i;
 874
 875         ASSERT_RTNL();
 876
 877         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
 878                 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request");
 879                 return -EINVAL;
 880         }
 881
 882         rtm = nlmsg_data(nlh);
 883         if (rtm->rtm_dst_len || rtm->rtm_src_len  || rtm->rtm_tos   ||
 884             rtm->rtm_scope) {
 885                 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request");
 886                 return -EINVAL;
 887         }
 888         if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) {
 889                 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request");
 890                 return -EINVAL;
 891         }
 892
 893         filter->dump_all_families = (rtm->rtm_family == AF_UNSPEC);
 894         filter->flags    = rtm->rtm_flags;
 895         filter->protocol = rtm->rtm_protocol;
 896         filter->rt_type  = rtm->rtm_type;
 897         filter->table_id = rtm->rtm_table;
 898
 899         err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
 900                                             rtm_ipv4_policy, extack);
 901         if (err < 0)
 902                 return err;
 903
 904         for (i = 0; i <= RTA_MAX; ++i) {
 905                 int ifindex;
 906
 907                 if (!tb[i])
 908                         continue;
 909
 910                 switch (i) {
 911                 case RTA_TABLE:
 912                         filter->table_id = nla_get_u32(tb[i]);
 913                         break;
 914                 case RTA_OIF:
 915                         ifindex = nla_get_u32(tb[i]);
 916                         filter->dev = __dev_get_by_index(net, ifindex);
 917                         if (!filter->dev)
 918                                 return -ENODEV;
 919                         break;
 920                 default:
 921                         NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
 922                         return -EINVAL;
 923                 }
 924         }
 925
 926         if (filter->flags || filter->protocol || filter->rt_type ||
 927             filter->table_id || filter->dev) {
 928                 filter->filter_set = 1;
 929                 cb->answer_flags = NLM_F_DUMP_FILTERED;
 930         }
 931
 932         return 0;
 933 }
 934 EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req);
 935
 936 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 937 {
 938         const struct nlmsghdr *nlh = cb->nlh;
 939         struct net *net = sock_net(skb->sk);
 940         struct fib_dump_filter filter = {};
 941         unsigned int h, s_h;
 942         unsigned int e = 0, s_e;
 943         struct fib_table *tb;
 944         struct hlist_head *head;
 945         int dumped = 0, err;
 946
 947         if (cb->strict_check) {
 948                 err = ip_valid_fib_dump_req(net, nlh, &filter, cb);
 949                 if (err < 0)
 950                         return err;
 951         } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
 952                 struct rtmsg *rtm = nlmsg_data(nlh);
 953
 954                 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED);
 955         }
 956
 957         /* fib entries are never clones and ipv4 does not use prefix flag */
 958         if (filter.flags & (RTM_F_PREFIX | RTM_F_CLONED))
 959                 return skb->len;
 960
 961         if (filter.table_id) {
 962                 tb = fib_get_table(net, filter.table_id);
 963                 if (!tb) {
 964                         if (filter.dump_all_families)
 965                                 return skb->len;
 966
 967                         NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist");
 968                         return -ENOENT;
 969                 }
 970
 971                 err = fib_table_dump(tb, skb, cb, &filter);
 972                 return skb->len ? : err;
 973         }
 974
 975         s_h = cb->args[0];
 976         s_e = cb->args[1];
 977
 978         rcu_read_lock();
 979
 980         for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
 981                 e = 0;
 982                 head = &net->ipv4.fib_table_hash[h];
 983                 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
 984                         if (e < s_e)
 985                                 goto next;
 986                         if (dumped)
 987                                 memset(&cb->args[2], 0, sizeof(cb->args) -
 988                                                  2 * sizeof(cb->args[0]));
 989                         err = fib_table_dump(tb, skb, cb, &filter);
 990                         if (err < 0) {
 991                                 if (likely(skb->len))
 992                                         goto out;
 993
 994                                 goto out_err;
 995                         }
 996                         dumped = 1;
 997 next:
 998                         e++;
 999                 }
1000         }
1001 out:
1002         err = skb->len;
1003 out_err:
1004         rcu_read_unlock();
1005
1006         cb->args[1] = e;
1007         cb->args[0] = h;
1008
1009         return err;
1010 }
1011
1012 /* Prepare and feed intra-kernel routing request.
1013  * Really, it should be netlink message, but :-( netlink
1014  * can be not configured, so that we feed it directly
1015  * to fib engine. It is legal, because all events occur
1016  * only when netlink is already locked.
1017  */
1018 static void fib_magic(int cmd, int type, __be32 dst, int dst_len,
1019                       struct in_ifaddr *ifa, u32 rt_priority)
1020 {
1021         struct net *net = dev_net(ifa->ifa_dev->dev);
1022         u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
1023         struct fib_table *tb;
1024         struct fib_config cfg = {
1025                 .fc_protocol = RTPROT_KERNEL,
1026                 .fc_type = type,
1027                 .fc_dst = dst,
1028                 .fc_dst_len = dst_len,
1029                 .fc_priority = rt_priority,
1030                 .fc_prefsrc = ifa->ifa_local,
1031                 .fc_oif = ifa->ifa_dev->dev->ifindex,
1032                 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
1033                 .fc_nlinfo = {
1034                         .nl_net = net,
1035                 },
1036         };
1037
1038         if (!tb_id)
1039                 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
1040
1041         tb = fib_new_table(net, tb_id);
1042         if (!tb)
1043                 return;
1044
1045         cfg.fc_table = tb->tb_id;
1046
1047         if (type != RTN_LOCAL)
1048                 cfg.fc_scope = RT_SCOPE_LINK;
1049         else
1050                 cfg.fc_scope = RT_SCOPE_HOST;
1051
1052         if (cmd == RTM_NEWROUTE)
1053                 fib_table_insert(net, tb, &cfg, NULL);
1054         else
1055                 fib_table_delete(net, tb, &cfg, NULL);
1056 }
1057
1058 void fib_add_ifaddr(struct in_ifaddr *ifa)
1059 {
1060         struct in_device *in_dev = ifa->ifa_dev;
1061         struct net_device *dev = in_dev->dev;
1062         struct in_ifaddr *prim = ifa;
1063         __be32 mask = ifa->ifa_mask;
1064         __be32 addr = ifa->ifa_local;
1065         __be32 prefix = ifa->ifa_address & mask;
1066
1067         if (ifa->ifa_flags & IFA_F_SECONDARY) {
1068                 prim = inet_ifa_byprefix(in_dev, prefix, mask);
1069                 if (!prim) {
1070                         pr_warn("%s: bug: prim == NULL\n", __func__);
1071                         return;
1072                 }
1073         }
1074
1075         fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0);
1076
1077         if (!(dev->flags & IFF_UP))
1078                 return;
1079
1080         /* Add broadcast address, if it is explicitly assigned. */
1081         if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
1082                 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1083                           prim, 0);
1084
1085         if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
1086             (prefix != addr || ifa->ifa_prefixlen < 32)) {
1087                 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1088                         fib_magic(RTM_NEWROUTE,
1089                                   dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1090                                   prefix, ifa->ifa_prefixlen, prim,
1091                                   ifa->ifa_rt_priority);
1092
1093                 /* Add network specific broadcasts, when it takes a sense */
1094                 if (ifa->ifa_prefixlen < 31) {
1095                         fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32,
1096                                   prim, 0);
1097                         fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
1098                                   32, prim, 0);
1099                 }
1100         }
1101 }
1102
1103 void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric)
1104 {
1105         __be32 prefix = ifa->ifa_address & ifa->ifa_mask;
1106         struct in_device *in_dev = ifa->ifa_dev;
1107         struct net_device *dev = in_dev->dev;
1108
1109         if (!(dev->flags & IFF_UP) ||
1110             ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) ||
1111             ipv4_is_zeronet(prefix) ||
1112             prefix == ifa->ifa_local || ifa->ifa_prefixlen == 32)
1113                 return;
1114
1115         /* add the new */
1116         fib_magic(RTM_NEWROUTE,
1117                   dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1118                   prefix, ifa->ifa_prefixlen, ifa, new_metric);
1119
1120         /* delete the old */
1121         fib_magic(RTM_DELROUTE,
1122                   dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1123                   prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority);
1124 }
1125
1126 /* Delete primary or secondary address.
1127  * Optionally, on secondary address promotion consider the addresses
1128  * from subnet iprim as deleted, even if they are in device list.
1129  * In this case the secondary ifa can be in device list.
1130  */
1131 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
1132 {
1133         struct in_device *in_dev = ifa->ifa_dev;
1134         struct net_device *dev = in_dev->dev;
1135         struct in_ifaddr *ifa1;
1136         struct in_ifaddr *prim = ifa, *prim1 = NULL;
1137         __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
1138         __be32 any = ifa->ifa_address & ifa->ifa_mask;
1139 #define LOCAL_OK        1
1140 #define BRD_OK          2
1141 #define BRD0_OK         4
1142 #define BRD1_OK         8
1143         unsigned int ok = 0;
1144         int subnet = 0;         /* Primary network */
1145         int gone = 1;           /* Address is missing */
1146         int same_prefsrc = 0;   /* Another primary with same IP */
1147
1148         if (ifa->ifa_flags & IFA_F_SECONDARY) {
1149                 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
1150                 if (!prim) {
1151                         /* if the device has been deleted, we don't perform
1152                          * address promotion
1153                          */
1154                         if (!in_dev->dead)
1155                                 pr_warn("%s: bug: prim == NULL\n", __func__);
1156                         return;
1157                 }
1158                 if (iprim && iprim != prim) {
1159                         pr_warn("%s: bug: iprim != prim\n", __func__);
1160                         return;
1161                 }
1162         } else if (!ipv4_is_zeronet(any) &&
1163                    (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
1164                 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1165                         fib_magic(RTM_DELROUTE,
1166                                   dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1167                                   any, ifa->ifa_prefixlen, prim, 0);
1168                 subnet = 1;
1169         }
1170
1171         if (in_dev->dead)
1172                 goto no_promotions;
1173
1174         /* Deletion is more complicated than add.
1175          * We should take care of not to delete too much :-)
1176          *
1177          * Scan address list to be sure that addresses are really gone.
1178          */
1179
1180         for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
1181                 if (ifa1 == ifa) {
1182                         /* promotion, keep the IP */
1183                         gone = 0;
1184                         continue;
1185                 }
1186                 /* Ignore IFAs from our subnet */
1187                 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
1188                     inet_ifa_match(ifa1->ifa_address, iprim))
1189                         continue;
1190
1191                 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
1192                 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
1193                         /* Another address from our subnet? */
1194                         if (ifa1->ifa_mask == prim->ifa_mask &&
1195                             inet_ifa_match(ifa1->ifa_address, prim))
1196                                 prim1 = prim;
1197                         else {
1198                                 /* We reached the secondaries, so
1199                                  * same_prefsrc should be determined.
1200                                  */
1201                                 if (!same_prefsrc)
1202                                         continue;
1203                                 /* Search new prim1 if ifa1 is not
1204                                  * using the current prim1
1205                                  */
1206                                 if (!prim1 ||
1207                                     ifa1->ifa_mask != prim1->ifa_mask ||
1208                                     !inet_ifa_match(ifa1->ifa_address, prim1))
1209                                         prim1 = inet_ifa_byprefix(in_dev,
1210                                                         ifa1->ifa_address,
1211                                                         ifa1->ifa_mask);
1212                                 if (!prim1)
1213                                         continue;
1214                                 if (prim1->ifa_local != prim->ifa_local)
1215                                         continue;
1216                         }
1217                 } else {
1218                         if (prim->ifa_local != ifa1->ifa_local)
1219                                 continue;
1220                         prim1 = ifa1;
1221                         if (prim != prim1)
1222                                 same_prefsrc = 1;
1223                 }
1224                 if (ifa->ifa_local == ifa1->ifa_local)
1225                         ok |= LOCAL_OK;
1226                 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1227                         ok |= BRD_OK;
1228                 if (brd == ifa1->ifa_broadcast)
1229                         ok |= BRD1_OK;
1230                 if (any == ifa1->ifa_broadcast)
1231                         ok |= BRD0_OK;
1232                 /* primary has network specific broadcasts */
1233                 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1234                         __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1235                         __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1236
1237                         if (!ipv4_is_zeronet(any1)) {
1238                                 if (ifa->ifa_broadcast == brd1 ||
1239                                     ifa->ifa_broadcast == any1)
1240                                         ok |= BRD_OK;
1241                                 if (brd == brd1 || brd == any1)
1242                                         ok |= BRD1_OK;
1243                                 if (any == brd1 || any == any1)
1244                                         ok |= BRD0_OK;
1245                         }
1246                 }
1247         }
1248
1249 no_promotions:
1250         if (!(ok & BRD_OK))
1251                 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1252                           prim, 0);
1253         if (subnet && ifa->ifa_prefixlen < 31) {
1254                 if (!(ok & BRD1_OK))
1255                         fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32,
1256                                   prim, 0);
1257                 if (!(ok & BRD0_OK))
1258                         fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32,
1259                                   prim, 0);
1260         }
1261         if (!(ok & LOCAL_OK)) {
1262                 unsigned int addr_type;
1263
1264                 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0);
1265
1266                 /* Check, that this local address finally disappeared. */
1267                 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1268                                                      ifa->ifa_local);
1269                 if (gone && addr_type != RTN_LOCAL) {
1270                         /* And the last, but not the least thing.
1271                          * We must flush stray FIB entries.
1272                          *
1273                          * First of all, we scan fib_info list searching
1274                          * for stray nexthop entries, then ignite fib_flush.
1275                          */
1276                         if (fib_sync_down_addr(dev, ifa->ifa_local))
1277                                 fib_flush(dev_net(dev));
1278                 }
1279         }
1280 #undef LOCAL_OK
1281 #undef BRD_OK
1282 #undef BRD0_OK
1283 #undef BRD1_OK
1284 }
1285
1286 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1287 {
1288
1289         struct fib_result       res;
1290         struct flowi4           fl4 = {
1291                 .flowi4_mark = frn->fl_mark,
1292                 .daddr = frn->fl_addr,
1293                 .flowi4_tos = frn->fl_tos,
1294                 .flowi4_scope = frn->fl_scope,
1295         };
1296         struct fib_table *tb;
1297
1298         rcu_read_lock();
1299
1300         tb = fib_get_table(net, frn->tb_id_in);
1301
1302         frn->err = -ENOENT;
1303         if (tb) {
1304                 local_bh_disable();
1305
1306                 frn->tb_id = tb->tb_id;
1307                 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1308
1309                 if (!frn->err) {
1310                         frn->prefixlen = res.prefixlen;
1311                         frn->nh_sel = res.nh_sel;
1312                         frn->type = res.type;
1313                         frn->scope = res.scope;
1314                 }
1315                 local_bh_enable();
1316         }
1317
1318         rcu_read_unlock();
1319 }
1320
1321 static void nl_fib_input(struct sk_buff *skb)
1322 {
1323         struct net *net;
1324         struct fib_result_nl *frn;
1325         struct nlmsghdr *nlh;
1326         u32 portid;
1327
1328         net = sock_net(skb->sk);
1329         nlh = nlmsg_hdr(skb);
1330         if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1331             skb->len < nlh->nlmsg_len ||
1332             nlmsg_len(nlh) < sizeof(*frn))
1333                 return;
1334
1335         skb = netlink_skb_clone(skb, GFP_KERNEL);
1336         if (!skb)
1337                 return;
1338         nlh = nlmsg_hdr(skb);
1339
1340         frn = (struct fib_result_nl *) nlmsg_data(nlh);
1341         nl_fib_lookup(net, frn);
1342
1343         portid = NETLINK_CB(skb).portid;      /* netlink portid */
1344         NETLINK_CB(skb).portid = 0;        /* from kernel */
1345         NETLINK_CB(skb).dst_group = 0;  /* unicast */
1346         netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1347 }
1348
1349 static int __net_init nl_fib_lookup_init(struct net *net)
1350 {
1351         struct sock *sk;
1352         struct netlink_kernel_cfg cfg = {
1353                 .input  = nl_fib_input,
1354         };
1355
1356         sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1357         if (!sk)
1358                 return -EAFNOSUPPORT;
1359         net->ipv4.fibnl = sk;
1360         return 0;
1361 }
1362
1363 static void nl_fib_lookup_exit(struct net *net)
1364 {
1365         netlink_kernel_release(net->ipv4.fibnl);
1366         net->ipv4.fibnl = NULL;
1367 }
1368
1369 static void fib_disable_ip(struct net_device *dev, unsigned long event,
1370                            bool force)
1371 {
1372         if (fib_sync_down_dev(dev, event, force))
1373                 fib_flush(dev_net(dev));
1374         else
1375                 rt_cache_flush(dev_net(dev));
1376         arp_ifdown(dev);
1377 }
1378
1379 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1380 {
1381         struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1382         struct net_device *dev = ifa->ifa_dev->dev;
1383         struct net *net = dev_net(dev);
1384
1385         switch (event) {
1386         case NETDEV_UP:
1387                 fib_add_ifaddr(ifa);
1388 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1389                 fib_sync_up(dev, RTNH_F_DEAD);
1390 #endif
1391                 atomic_inc(&net->ipv4.dev_addr_genid);
1392                 rt_cache_flush(dev_net(dev));
1393                 break;
1394         case NETDEV_DOWN:
1395                 fib_del_ifaddr(ifa, NULL);
1396                 atomic_inc(&net->ipv4.dev_addr_genid);
1397                 if (!ifa->ifa_dev->ifa_list) {
1398                         /* Last address was deleted from this interface.
1399                          * Disable IP.
1400                          */
1401                         fib_disable_ip(dev, event, true);
1402                 } else {
1403                         rt_cache_flush(dev_net(dev));
1404                 }
1405                 break;
1406         }
1407         return NOTIFY_DONE;
1408 }
1409
1410 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1411 {
1412         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1413         struct netdev_notifier_changeupper_info *upper_info = ptr;
1414         struct netdev_notifier_info_ext *info_ext = ptr;
1415         struct in_device *in_dev;
1416         struct net *net = dev_net(dev);
1417         unsigned int flags;
1418
1419         if (event == NETDEV_UNREGISTER) {
1420                 fib_disable_ip(dev, event, true);
1421                 rt_flush_dev(dev);
1422                 return NOTIFY_DONE;
1423         }
1424
1425         in_dev = __in_dev_get_rtnl(dev);
1426         if (!in_dev)
1427                 return NOTIFY_DONE;
1428
1429         switch (event) {
1430         case NETDEV_UP:
1431                 for_ifa(in_dev) {
1432                         fib_add_ifaddr(ifa);
1433                 } endfor_ifa(in_dev);
1434 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1435                 fib_sync_up(dev, RTNH_F_DEAD);
1436 #endif
1437                 atomic_inc(&net->ipv4.dev_addr_genid);
1438                 rt_cache_flush(net);
1439                 break;
1440         case NETDEV_DOWN:
1441                 fib_disable_ip(dev, event, false);
1442                 break;
1443         case NETDEV_CHANGE:
1444                 flags = dev_get_flags(dev);
1445                 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1446                         fib_sync_up(dev, RTNH_F_LINKDOWN);
1447                 else
1448                         fib_sync_down_dev(dev, event, false);
1449                 rt_cache_flush(net);
1450                 break;
1451         case NETDEV_CHANGEMTU:
1452                 fib_sync_mtu(dev, info_ext->ext.mtu);
1453                 rt_cache_flush(net);
1454                 break;
1455         case NETDEV_CHANGEUPPER:
1456                 upper_info = ptr;
1457                 /* flush all routes if dev is linked to or unlinked from
1458                  * an L3 master device (e.g., VRF)
1459                  */
1460                 if (upper_info->upper_dev &&
1461                     netif_is_l3_master(upper_info->upper_dev))
1462                         fib_disable_ip(dev, NETDEV_DOWN, true);
1463                 break;
1464         }
1465         return NOTIFY_DONE;
1466 }
1467
1468 static struct notifier_block fib_inetaddr_notifier = {
1469         .notifier_call = fib_inetaddr_event,
1470 };
1471
1472 static struct notifier_block fib_netdev_notifier = {
1473         .notifier_call = fib_netdev_event,
1474 };
1475
1476 static int __net_init ip_fib_net_init(struct net *net)
1477 {
1478         int err;
1479         size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1480
1481         err = fib4_notifier_init(net);
1482         if (err)
1483                 return err;
1484
1485         /* Avoid false sharing : Use at least a full cache line */
1486         size = max_t(size_t, size, L1_CACHE_BYTES);
1487
1488         net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1489         if (!net->ipv4.fib_table_hash) {
1490                 err = -ENOMEM;
1491                 goto err_table_hash_alloc;
1492         }
1493
1494         err = fib4_rules_init(net);
1495         if (err < 0)
1496                 goto err_rules_init;
1497         return 0;
1498
1499 err_rules_init:
1500         kfree(net->ipv4.fib_table_hash);
1501 err_table_hash_alloc:
1502         fib4_notifier_exit(net);
1503         return err;
1504 }
1505
1506 static void ip_fib_net_exit(struct net *net)
1507 {
1508         int i;
1509
1510         rtnl_lock();
1511 #ifdef CONFIG_IP_MULTIPLE_TABLES
1512         RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1513         RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1514 #endif
1515         /* Destroy the tables in reverse order to guarantee that the
1516          * local table, ID 255, is destroyed before the main table, ID
1517          * 254. This is necessary as the local table may contain
1518          * references to data contained in the main table.
1519          */
1520         for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1521                 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1522                 struct hlist_node *tmp;
1523                 struct fib_table *tb;
1524
1525                 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1526                         hlist_del(&tb->tb_hlist);
1527                         fib_table_flush(net, tb, true);
1528                         fib_free_table(tb);
1529                 }
1530         }
1531
1532 #ifdef CONFIG_IP_MULTIPLE_TABLES
1533         fib4_rules_exit(net);
1534 #endif
1535         rtnl_unlock();
1536         kfree(net->ipv4.fib_table_hash);
1537         fib4_notifier_exit(net);
1538 }
1539
1540 static int __net_init fib_net_init(struct net *net)
1541 {
1542         int error;
1543
1544 #ifdef CONFIG_IP_ROUTE_CLASSID
1545         net->ipv4.fib_num_tclassid_users = 0;
1546 #endif
1547         error = ip_fib_net_init(net);
1548         if (error < 0)
1549                 goto out;
1550         error = nl_fib_lookup_init(net);
1551         if (error < 0)
1552                 goto out_nlfl;
1553         error = fib_proc_init(net);
1554         if (error < 0)
1555                 goto out_proc;
1556 out:
1557         return error;
1558
1559 out_proc:
1560         nl_fib_lookup_exit(net);
1561 out_nlfl:
1562         ip_fib_net_exit(net);
1563         goto out;
1564 }
1565
1566 static void __net_exit fib_net_exit(struct net *net)
1567 {
1568         fib_proc_exit(net);
1569         nl_fib_lookup_exit(net);
1570         ip_fib_net_exit(net);
1571 }
1572
1573 static struct pernet_operations fib_net_ops = {
1574         .init = fib_net_init,
1575         .exit = fib_net_exit,
1576 };
1577
1578 void __init ip_fib_init(void)
1579 {
1580         fib_trie_init();
1581
1582         register_pernet_subsys(&fib_net_ops);
1583
1584         register_netdevice_notifier(&fib_netdev_notifier);
1585         register_inetaddr_notifier(&fib_inetaddr_notifier);
1586
1587         rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0);
1588         rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0);
1589         rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0);
1590 }