net/ipv4/sysctl_net_ipv4.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * sysctl_net_ipv4.c: sysctl interface to net IPV4 subsystem.
   4  *
   5  * Begun April 1, 1996, Mike Shaver.
   6  * Added /proc/sys/net/ipv4 directory entry (empty =) ). [MS]
   7  */
   8
   9 #include <linux/mm.h>
  10 #include <linux/module.h>
  11 #include <linux/sysctl.h>
  12 #include <linux/igmp.h>
  13 #include <linux/inetdevice.h>
  14 #include <linux/seqlock.h>
  15 #include <linux/init.h>
  16 #include <linux/slab.h>
  17 #include <linux/nsproxy.h>
  18 #include <linux/swap.h>
  19 #include <net/snmp.h>
  20 #include <net/icmp.h>
  21 #include <net/ip.h>
  22 #include <net/route.h>
  23 #include <net/tcp.h>
  24 #include <net/udp.h>
  25 #include <net/cipso_ipv4.h>
  26 #include <net/inet_frag.h>
  27 #include <net/ping.h>
  28 #include <net/protocol.h>
  29 #include <net/netevent.h>
  30
  31 static int zero;
  32 static int one = 1;
  33 static int four = 4;
  34 static int thousand = 1000;
  35 static int gso_max_segs = GSO_MAX_SEGS;
  36 static int tcp_retr1_max = 255;
  37 static int ip_local_port_range_min[] = { 1, 1 };
  38 static int ip_local_port_range_max[] = { 65535, 65535 };
  39 static int tcp_adv_win_scale_min = -31;
  40 static int tcp_adv_win_scale_max = 31;
  41 static int ip_privileged_port_min;
  42 static int ip_privileged_port_max = 65535;
  43 static int ip_ttl_min = 1;
  44 static int ip_ttl_max = 255;
  45 static int tcp_syn_retries_min = 1;
  46 static int tcp_syn_retries_max = MAX_TCP_SYNCNT;
  47 static int ip_ping_group_range_min[] = { 0, 0 };
  48 static int ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX };
  49
  50 /* obsolete */
  51 static int sysctl_tcp_low_latency __read_mostly;
  52
  53 /* Update system visible IP port range */
  54 static void set_local_port_range(struct net *net, int range[2])
  55 {
  56         bool same_parity = !((range[0] ^ range[1]) & 1);
  57
  58         write_seqlock_bh(&net->ipv4.ip_local_ports.lock);
  59         if (same_parity && !net->ipv4.ip_local_ports.warned) {
  60                 net->ipv4.ip_local_ports.warned = true;
  61                 pr_err_ratelimited("ip_local_port_range: prefer different parity for start/end values.\n");
  62         }
  63         net->ipv4.ip_local_ports.range[0] = range[0];
  64         net->ipv4.ip_local_ports.range[1] = range[1];
  65         write_sequnlock_bh(&net->ipv4.ip_local_ports.lock);
  66 }
  67
  68 /* Validate changes from /proc interface. */
  69 static int ipv4_local_port_range(struct ctl_table *table, int write,
  70                                  void __user *buffer,
  71                                  size_t *lenp, loff_t *ppos)
  72 {
  73         struct net *net =
  74                 container_of(table->data, struct net, ipv4.ip_local_ports.range);
  75         int ret;
  76         int range[2];
  77         struct ctl_table tmp = {
  78                 .data = &range,
  79                 .maxlen = sizeof(range),
  80                 .mode = table->mode,
  81                 .extra1 = &ip_local_port_range_min,
  82                 .extra2 = &ip_local_port_range_max,
  83         };
  84
  85         inet_get_local_port_range(net, &range[0], &range[1]);
  86
  87         ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
  88
  89         if (write && ret == 0) {
  90                 /* Ensure that the upper limit is not smaller than the lower,
  91                  * and that the lower does not encroach upon the privileged
  92                  * port limit.
  93                  */
  94                 if ((range[1] < range[0]) ||
  95                     (range[0] < net->ipv4.sysctl_ip_prot_sock))
  96                         ret = -EINVAL;
  97                 else
  98                         set_local_port_range(net, range);
  99         }
 100
 101         return ret;
 102 }
 103
 104 /* Validate changes from /proc interface. */
 105 static int ipv4_privileged_ports(struct ctl_table *table, int write,
 106                                 void __user *buffer, size_t *lenp, loff_t *ppos)
 107 {
 108         struct net *net = container_of(table->data, struct net,
 109             ipv4.sysctl_ip_prot_sock);
 110         int ret;
 111         int pports;
 112         int range[2];
 113         struct ctl_table tmp = {
 114                 .data = &pports,
 115                 .maxlen = sizeof(pports),
 116                 .mode = table->mode,
 117                 .extra1 = &ip_privileged_port_min,
 118                 .extra2 = &ip_privileged_port_max,
 119         };
 120
 121         pports = net->ipv4.sysctl_ip_prot_sock;
 122
 123         ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
 124
 125         if (write && ret == 0) {
 126                 inet_get_local_port_range(net, &range[0], &range[1]);
 127                 /* Ensure that the local port range doesn't overlap with the
 128                  * privileged port range.
 129                  */
 130                 if (range[0] < pports)
 131                         ret = -EINVAL;
 132                 else
 133                         net->ipv4.sysctl_ip_prot_sock = pports;
 134         }
 135
 136         return ret;
 137 }
 138
 139 static void inet_get_ping_group_range_table(struct ctl_table *table, kgid_t *low, kgid_t *high)
 140 {
 141         kgid_t *data = table->data;
 142         struct net *net =
 143                 container_of(table->data, struct net, ipv4.ping_group_range.range);
 144         unsigned int seq;
 145         do {
 146                 seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
 147
 148                 *low = data[0];
 149                 *high = data[1];
 150         } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
 151 }
 152
 153 /* Update system visible IP port range */
 154 static void set_ping_group_range(struct ctl_table *table, kgid_t low, kgid_t high)
 155 {
 156         kgid_t *data = table->data;
 157         struct net *net =
 158                 container_of(table->data, struct net, ipv4.ping_group_range.range);
 159         write_seqlock(&net->ipv4.ping_group_range.lock);
 160         data[0] = low;
 161         data[1] = high;
 162         write_sequnlock(&net->ipv4.ping_group_range.lock);
 163 }
 164
 165 /* Validate changes from /proc interface. */
 166 static int ipv4_ping_group_range(struct ctl_table *table, int write,
 167                                  void __user *buffer,
 168                                  size_t *lenp, loff_t *ppos)
 169 {
 170         struct user_namespace *user_ns = current_user_ns();
 171         int ret;
 172         gid_t urange[2];
 173         kgid_t low, high;
 174         struct ctl_table tmp = {
 175                 .data = &urange,
 176                 .maxlen = sizeof(urange),
 177                 .mode = table->mode,
 178                 .extra1 = &ip_ping_group_range_min,
 179                 .extra2 = &ip_ping_group_range_max,
 180         };
 181
 182         inet_get_ping_group_range_table(table, &low, &high);
 183         urange[0] = from_kgid_munged(user_ns, low);
 184         urange[1] = from_kgid_munged(user_ns, high);
 185         ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
 186
 187         if (write && ret == 0) {
 188                 low = make_kgid(user_ns, urange[0]);
 189                 high = make_kgid(user_ns, urange[1]);
 190                 if (!gid_valid(low) || !gid_valid(high) ||
 191                     (urange[1] < urange[0]) || gid_lt(high, low)) {
 192                         low = make_kgid(&init_user_ns, 1);
 193                         high = make_kgid(&init_user_ns, 0);
 194                 }
 195                 set_ping_group_range(table, low, high);
 196         }
 197
 198         return ret;
 199 }
 200
 201 static int proc_tcp_congestion_control(struct ctl_table *ctl, int write,
 202                                        void __user *buffer, size_t *lenp, loff_t *ppos)
 203 {
 204         struct net *net = container_of(ctl->data, struct net,
 205                                        ipv4.tcp_congestion_control);
 206         char val[TCP_CA_NAME_MAX];
 207         struct ctl_table tbl = {
 208                 .data = val,
 209                 .maxlen = TCP_CA_NAME_MAX,
 210         };
 211         int ret;
 212
 213         tcp_get_default_congestion_control(net, val);
 214
 215         ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
 216         if (write && ret == 0)
 217                 ret = tcp_set_default_congestion_control(net, val);
 218         return ret;
 219 }
 220
 221 static int proc_tcp_available_congestion_control(struct ctl_table *ctl,
 222                                                  int write,
 223                                                  void __user *buffer, size_t *lenp,
 224                                                  loff_t *ppos)
 225 {
 226         struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX, };
 227         int ret;
 228
 229         tbl.data = kmalloc(tbl.maxlen, GFP_USER);
 230         if (!tbl.data)
 231                 return -ENOMEM;
 232         tcp_get_available_congestion_control(tbl.data, TCP_CA_BUF_MAX);
 233         ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
 234         kfree(tbl.data);
 235         return ret;
 236 }
 237
 238 static int proc_allowed_congestion_control(struct ctl_table *ctl,
 239                                            int write,
 240                                            void __user *buffer, size_t *lenp,
 241                                            loff_t *ppos)
 242 {
 243         struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX };
 244         int ret;
 245
 246         tbl.data = kmalloc(tbl.maxlen, GFP_USER);
 247         if (!tbl.data)
 248                 return -ENOMEM;
 249
 250         tcp_get_allowed_congestion_control(tbl.data, tbl.maxlen);
 251         ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
 252         if (write && ret == 0)
 253                 ret = tcp_set_allowed_congestion_control(tbl.data);
 254         kfree(tbl.data);
 255         return ret;
 256 }
 257
 258 static int proc_tcp_fastopen_key(struct ctl_table *table, int write,
 259                                  void __user *buffer, size_t *lenp,
 260                                  loff_t *ppos)
 261 {
 262         struct net *net = container_of(table->data, struct net,
 263             ipv4.sysctl_tcp_fastopen);
 264         struct ctl_table tbl = { .maxlen = (TCP_FASTOPEN_KEY_LENGTH * 2 + 10) };
 265         struct tcp_fastopen_context *ctxt;
 266         int ret;
 267         u32  user_key[4]; /* 16 bytes, matching TCP_FASTOPEN_KEY_LENGTH */
 268
 269         tbl.data = kmalloc(tbl.maxlen, GFP_KERNEL);
 270         if (!tbl.data)
 271                 return -ENOMEM;
 272
 273         rcu_read_lock();
 274         ctxt = rcu_dereference(net->ipv4.tcp_fastopen_ctx);
 275         if (ctxt)
 276                 memcpy(user_key, ctxt->key, TCP_FASTOPEN_KEY_LENGTH);
 277         else
 278                 memset(user_key, 0, sizeof(user_key));
 279         rcu_read_unlock();
 280
 281         snprintf(tbl.data, tbl.maxlen, "%08x-%08x-%08x-%08x",
 282                 user_key[0], user_key[1], user_key[2], user_key[3]);
 283         ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
 284
 285         if (write && ret == 0) {
 286                 if (sscanf(tbl.data, "%x-%x-%x-%x", user_key, user_key + 1,
 287                            user_key + 2, user_key + 3) != 4) {
 288                         ret = -EINVAL;
 289                         goto bad_key;
 290                 }
 291                 tcp_fastopen_reset_cipher(net, NULL, user_key,
 292                                           TCP_FASTOPEN_KEY_LENGTH);
 293         }
 294
 295 bad_key:
 296         pr_debug("proc FO key set 0x%x-%x-%x-%x <- 0x%s: %u\n",
 297                user_key[0], user_key[1], user_key[2], user_key[3],
 298                (char *)tbl.data, ret);
 299         kfree(tbl.data);
 300         return ret;
 301 }
 302
 303 static void proc_configure_early_demux(int enabled, int protocol)
 304 {
 305         struct net_protocol *ipprot;
 306 #if IS_ENABLED(CONFIG_IPV6)
 307         struct inet6_protocol *ip6prot;
 308 #endif
 309
 310         rcu_read_lock();
 311
 312         ipprot = rcu_dereference(inet_protos[protocol]);
 313         if (ipprot)
 314                 ipprot->early_demux = enabled ? ipprot->early_demux_handler :
 315                                                 NULL;
 316
 317 #if IS_ENABLED(CONFIG_IPV6)
 318         ip6prot = rcu_dereference(inet6_protos[protocol]);
 319         if (ip6prot)
 320                 ip6prot->early_demux = enabled ? ip6prot->early_demux_handler :
 321                                                  NULL;
 322 #endif
 323         rcu_read_unlock();
 324 }
 325
 326 static int proc_tcp_early_demux(struct ctl_table *table, int write,
 327                                 void __user *buffer, size_t *lenp, loff_t *ppos)
 328 {
 329         int ret = 0;
 330
 331         ret = proc_dointvec(table, write, buffer, lenp, ppos);
 332
 333         if (write && !ret) {
 334                 int enabled = init_net.ipv4.sysctl_tcp_early_demux;
 335
 336                 proc_configure_early_demux(enabled, IPPROTO_TCP);
 337         }
 338
 339         return ret;
 340 }
 341
 342 static int proc_udp_early_demux(struct ctl_table *table, int write,
 343                                 void __user *buffer, size_t *lenp, loff_t *ppos)
 344 {
 345         int ret = 0;
 346
 347         ret = proc_dointvec(table, write, buffer, lenp, ppos);
 348
 349         if (write && !ret) {
 350                 int enabled = init_net.ipv4.sysctl_udp_early_demux;
 351
 352                 proc_configure_early_demux(enabled, IPPROTO_UDP);
 353         }
 354
 355         return ret;
 356 }
 357
 358 static int proc_tfo_blackhole_detect_timeout(struct ctl_table *table,
 359                                              int write,
 360                                              void __user *buffer,
 361                                              size_t *lenp, loff_t *ppos)
 362 {
 363         struct net *net = container_of(table->data, struct net,
 364             ipv4.sysctl_tcp_fastopen_blackhole_timeout);
 365         int ret;
 366
 367         ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 368         if (write && ret == 0)
 369                 atomic_set(&net->ipv4.tfo_active_disable_times, 0);
 370
 371         return ret;
 372 }
 373
 374 static int proc_tcp_available_ulp(struct ctl_table *ctl,
 375                                   int write,
 376                                   void __user *buffer, size_t *lenp,
 377                                   loff_t *ppos)
 378 {
 379         struct ctl_table tbl = { .maxlen = TCP_ULP_BUF_MAX, };
 380         int ret;
 381
 382         tbl.data = kmalloc(tbl.maxlen, GFP_USER);
 383         if (!tbl.data)
 384                 return -ENOMEM;
 385         tcp_get_available_ulp(tbl.data, TCP_ULP_BUF_MAX);
 386         ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
 387         kfree(tbl.data);
 388
 389         return ret;
 390 }
 391
 392 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 393 static int proc_fib_multipath_hash_policy(struct ctl_table *table, int write,
 394                                           void __user *buffer, size_t *lenp,
 395                                           loff_t *ppos)
 396 {
 397         struct net *net = container_of(table->data, struct net,
 398             ipv4.sysctl_fib_multipath_hash_policy);
 399         int ret;
 400
 401         ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 402         if (write && ret == 0)
 403                 call_netevent_notifiers(NETEVENT_MULTIPATH_HASH_UPDATE, net);
 404
 405         return ret;
 406 }
 407 #endif
 408
 409 static struct ctl_table ipv4_table[] = {
 410         {
 411                 .procname       = "tcp_max_orphans",
 412                 .data           = &sysctl_tcp_max_orphans,
 413                 .maxlen         = sizeof(int),
 414                 .mode           = 0644,
 415                 .proc_handler   = proc_dointvec
 416         },
 417         {
 418                 .procname       = "inet_peer_threshold",
 419                 .data           = &inet_peer_threshold,
 420                 .maxlen         = sizeof(int),
 421                 .mode           = 0644,
 422                 .proc_handler   = proc_dointvec
 423         },
 424         {
 425                 .procname       = "inet_peer_minttl",
 426                 .data           = &inet_peer_minttl,
 427                 .maxlen         = sizeof(int),
 428                 .mode           = 0644,
 429                 .proc_handler   = proc_dointvec_jiffies,
 430         },
 431         {
 432                 .procname       = "inet_peer_maxttl",
 433                 .data           = &inet_peer_maxttl,
 434                 .maxlen         = sizeof(int),
 435                 .mode           = 0644,
 436                 .proc_handler   = proc_dointvec_jiffies,
 437         },
 438         {
 439                 .procname       = "tcp_mem",
 440                 .maxlen         = sizeof(sysctl_tcp_mem),
 441                 .data           = &sysctl_tcp_mem,
 442                 .mode           = 0644,
 443                 .proc_handler   = proc_doulongvec_minmax,
 444         },
 445         {
 446                 .procname       = "tcp_low_latency",
 447                 .data           = &sysctl_tcp_low_latency,
 448                 .maxlen         = sizeof(int),
 449                 .mode           = 0644,
 450                 .proc_handler   = proc_dointvec
 451         },
 452 #ifdef CONFIG_NETLABEL
 453         {
 454                 .procname       = "cipso_cache_enable",
 455                 .data           = &cipso_v4_cache_enabled,
 456                 .maxlen         = sizeof(int),
 457                 .mode           = 0644,
 458                 .proc_handler   = proc_dointvec,
 459         },
 460         {
 461                 .procname       = "cipso_cache_bucket_size",
 462                 .data           = &cipso_v4_cache_bucketsize,
 463                 .maxlen         = sizeof(int),
 464                 .mode           = 0644,
 465                 .proc_handler   = proc_dointvec,
 466         },
 467         {
 468                 .procname       = "cipso_rbm_optfmt",
 469                 .data           = &cipso_v4_rbm_optfmt,
 470                 .maxlen         = sizeof(int),
 471                 .mode           = 0644,
 472                 .proc_handler   = proc_dointvec,
 473         },
 474         {
 475                 .procname       = "cipso_rbm_strictvalid",
 476                 .data           = &cipso_v4_rbm_strictvalid,
 477                 .maxlen         = sizeof(int),
 478                 .mode           = 0644,
 479                 .proc_handler   = proc_dointvec,
 480         },
 481 #endif /* CONFIG_NETLABEL */
 482         {
 483                 .procname       = "tcp_available_congestion_control",
 484                 .maxlen         = TCP_CA_BUF_MAX,
 485                 .mode           = 0444,
 486                 .proc_handler   = proc_tcp_available_congestion_control,
 487         },
 488         {
 489                 .procname       = "tcp_allowed_congestion_control",
 490                 .maxlen         = TCP_CA_BUF_MAX,
 491                 .mode           = 0644,
 492                 .proc_handler   = proc_allowed_congestion_control,
 493         },
 494         {
 495                 .procname       = "tcp_available_ulp",
 496                 .maxlen         = TCP_ULP_BUF_MAX,
 497                 .mode           = 0444,
 498                 .proc_handler   = proc_tcp_available_ulp,
 499         },
 500         {
 501                 .procname       = "icmp_msgs_per_sec",
 502                 .data           = &sysctl_icmp_msgs_per_sec,
 503                 .maxlen         = sizeof(int),
 504                 .mode           = 0644,
 505                 .proc_handler   = proc_dointvec_minmax,
 506                 .extra1         = &zero,
 507         },
 508         {
 509                 .procname       = "icmp_msgs_burst",
 510                 .data           = &sysctl_icmp_msgs_burst,
 511                 .maxlen         = sizeof(int),
 512                 .mode           = 0644,
 513                 .proc_handler   = proc_dointvec_minmax,
 514                 .extra1         = &zero,
 515         },
 516         {
 517                 .procname       = "udp_mem",
 518                 .data           = &sysctl_udp_mem,
 519                 .maxlen         = sizeof(sysctl_udp_mem),
 520                 .mode           = 0644,
 521                 .proc_handler   = proc_doulongvec_minmax,
 522         },
 523         {
 524                 .procname       = "udp_rmem_min",
 525                 .data           = &sysctl_udp_rmem_min,
 526                 .maxlen         = sizeof(sysctl_udp_rmem_min),
 527                 .mode           = 0644,
 528                 .proc_handler   = proc_dointvec_minmax,
 529                 .extra1         = &one
 530         },
 531         {
 532                 .procname       = "udp_wmem_min",
 533                 .data           = &sysctl_udp_wmem_min,
 534                 .maxlen         = sizeof(sysctl_udp_wmem_min),
 535                 .mode           = 0644,
 536                 .proc_handler   = proc_dointvec_minmax,
 537                 .extra1         = &one
 538         },
 539         { }
 540 };
 541
 542 static struct ctl_table ipv4_net_table[] = {
 543         {
 544                 .procname       = "icmp_echo_ignore_all",
 545                 .data           = &init_net.ipv4.sysctl_icmp_echo_ignore_all,
 546                 .maxlen         = sizeof(int),
 547                 .mode           = 0644,
 548                 .proc_handler   = proc_dointvec
 549         },
 550         {
 551                 .procname       = "icmp_echo_ignore_broadcasts",
 552                 .data           = &init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts,
 553                 .maxlen         = sizeof(int),
 554                 .mode           = 0644,
 555                 .proc_handler   = proc_dointvec
 556         },
 557         {
 558                 .procname       = "icmp_ignore_bogus_error_responses",
 559                 .data           = &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses,
 560                 .maxlen         = sizeof(int),
 561                 .mode           = 0644,
 562                 .proc_handler   = proc_dointvec
 563         },
 564         {
 565                 .procname       = "icmp_errors_use_inbound_ifaddr",
 566                 .data           = &init_net.ipv4.sysctl_icmp_errors_use_inbound_ifaddr,
 567                 .maxlen         = sizeof(int),
 568                 .mode           = 0644,
 569                 .proc_handler   = proc_dointvec
 570         },
 571         {
 572                 .procname       = "icmp_ratelimit",
 573                 .data           = &init_net.ipv4.sysctl_icmp_ratelimit,
 574                 .maxlen         = sizeof(int),
 575                 .mode           = 0644,
 576                 .proc_handler   = proc_dointvec_ms_jiffies,
 577         },
 578         {
 579                 .procname       = "icmp_ratemask",
 580                 .data           = &init_net.ipv4.sysctl_icmp_ratemask,
 581                 .maxlen         = sizeof(int),
 582                 .mode           = 0644,
 583                 .proc_handler   = proc_dointvec
 584         },
 585         {
 586                 .procname       = "ping_group_range",
 587                 .data           = &init_net.ipv4.ping_group_range.range,
 588                 .maxlen         = sizeof(gid_t)*2,
 589                 .mode           = 0644,
 590                 .proc_handler   = ipv4_ping_group_range,
 591         },
 592         {
 593                 .procname       = "tcp_ecn",
 594                 .data           = &init_net.ipv4.sysctl_tcp_ecn,
 595                 .maxlen         = sizeof(int),
 596                 .mode           = 0644,
 597                 .proc_handler   = proc_dointvec
 598         },
 599         {
 600                 .procname       = "tcp_ecn_fallback",
 601                 .data           = &init_net.ipv4.sysctl_tcp_ecn_fallback,
 602                 .maxlen         = sizeof(int),
 603                 .mode           = 0644,
 604                 .proc_handler   = proc_dointvec
 605         },
 606         {
 607                 .procname       = "ip_dynaddr",
 608                 .data           = &init_net.ipv4.sysctl_ip_dynaddr,
 609                 .maxlen         = sizeof(int),
 610                 .mode           = 0644,
 611                 .proc_handler   = proc_dointvec
 612         },
 613         {
 614                 .procname       = "ip_early_demux",
 615                 .data           = &init_net.ipv4.sysctl_ip_early_demux,
 616                 .maxlen         = sizeof(int),
 617                 .mode           = 0644,
 618                 .proc_handler   = proc_dointvec
 619         },
 620         {
 621                 .procname       = "udp_early_demux",
 622                 .data           = &init_net.ipv4.sysctl_udp_early_demux,
 623                 .maxlen         = sizeof(int),
 624                 .mode           = 0644,
 625                 .proc_handler   = proc_udp_early_demux
 626         },
 627         {
 628                 .procname       = "tcp_early_demux",
 629                 .data           = &init_net.ipv4.sysctl_tcp_early_demux,
 630                 .maxlen         = sizeof(int),
 631                 .mode           = 0644,
 632                 .proc_handler   = proc_tcp_early_demux
 633         },
 634         {
 635                 .procname       = "ip_default_ttl",
 636                 .data           = &init_net.ipv4.sysctl_ip_default_ttl,
 637                 .maxlen         = sizeof(int),
 638                 .mode           = 0644,
 639                 .proc_handler   = proc_dointvec_minmax,
 640                 .extra1         = &ip_ttl_min,
 641                 .extra2         = &ip_ttl_max,
 642         },
 643         {
 644                 .procname       = "ip_local_port_range",
 645                 .maxlen         = sizeof(init_net.ipv4.ip_local_ports.range),
 646                 .data           = &init_net.ipv4.ip_local_ports.range,
 647                 .mode           = 0644,
 648                 .proc_handler   = ipv4_local_port_range,
 649         },
 650         {
 651                 .procname       = "ip_local_reserved_ports",
 652                 .data           = &init_net.ipv4.sysctl_local_reserved_ports,
 653                 .maxlen         = 65536,
 654                 .mode           = 0644,
 655                 .proc_handler   = proc_do_large_bitmap,
 656         },
 657         {
 658                 .procname       = "ip_no_pmtu_disc",
 659                 .data           = &init_net.ipv4.sysctl_ip_no_pmtu_disc,
 660                 .maxlen         = sizeof(int),
 661                 .mode           = 0644,
 662                 .proc_handler   = proc_dointvec
 663         },
 664         {
 665                 .procname       = "ip_forward_use_pmtu",
 666                 .data           = &init_net.ipv4.sysctl_ip_fwd_use_pmtu,
 667                 .maxlen         = sizeof(int),
 668                 .mode           = 0644,
 669                 .proc_handler   = proc_dointvec,
 670         },
 671         {
 672                 .procname       = "ip_nonlocal_bind",
 673                 .data           = &init_net.ipv4.sysctl_ip_nonlocal_bind,
 674                 .maxlen         = sizeof(int),
 675                 .mode           = 0644,
 676                 .proc_handler   = proc_dointvec
 677         },
 678         {
 679                 .procname       = "fwmark_reflect",
 680                 .data           = &init_net.ipv4.sysctl_fwmark_reflect,
 681                 .maxlen         = sizeof(int),
 682                 .mode           = 0644,
 683                 .proc_handler   = proc_dointvec,
 684         },
 685         {
 686                 .procname       = "tcp_fwmark_accept",
 687                 .data           = &init_net.ipv4.sysctl_tcp_fwmark_accept,
 688                 .maxlen         = sizeof(int),
 689                 .mode           = 0644,
 690                 .proc_handler   = proc_dointvec,
 691         },
 692 #ifdef CONFIG_NET_L3_MASTER_DEV
 693         {
 694                 .procname       = "tcp_l3mdev_accept",
 695                 .data           = &init_net.ipv4.sysctl_tcp_l3mdev_accept,
 696                 .maxlen         = sizeof(int),
 697                 .mode           = 0644,
 698                 .proc_handler   = proc_dointvec_minmax,
 699                 .extra1         = &zero,
 700                 .extra2         = &one,
 701         },
 702 #endif
 703         {
 704                 .procname       = "tcp_mtu_probing",
 705                 .data           = &init_net.ipv4.sysctl_tcp_mtu_probing,
 706                 .maxlen         = sizeof(int),
 707                 .mode           = 0644,
 708                 .proc_handler   = proc_dointvec,
 709         },
 710         {
 711                 .procname       = "tcp_base_mss",
 712                 .data           = &init_net.ipv4.sysctl_tcp_base_mss,
 713                 .maxlen         = sizeof(int),
 714                 .mode           = 0644,
 715                 .proc_handler   = proc_dointvec,
 716         },
 717         {
 718                 .procname       = "tcp_probe_threshold",
 719                 .data           = &init_net.ipv4.sysctl_tcp_probe_threshold,
 720                 .maxlen         = sizeof(int),
 721                 .mode           = 0644,
 722                 .proc_handler   = proc_dointvec,
 723         },
 724         {
 725                 .procname       = "tcp_probe_interval",
 726                 .data           = &init_net.ipv4.sysctl_tcp_probe_interval,
 727                 .maxlen         = sizeof(int),
 728                 .mode           = 0644,
 729                 .proc_handler   = proc_dointvec,
 730         },
 731         {
 732                 .procname       = "igmp_link_local_mcast_reports",
 733                 .data           = &init_net.ipv4.sysctl_igmp_llm_reports,
 734                 .maxlen         = sizeof(int),
 735                 .mode           = 0644,
 736                 .proc_handler   = proc_dointvec
 737         },
 738         {
 739                 .procname       = "igmp_max_memberships",
 740                 .data           = &init_net.ipv4.sysctl_igmp_max_memberships,
 741                 .maxlen         = sizeof(int),
 742                 .mode           = 0644,
 743                 .proc_handler   = proc_dointvec
 744         },
 745         {
 746                 .procname       = "igmp_max_msf",
 747                 .data           = &init_net.ipv4.sysctl_igmp_max_msf,
 748                 .maxlen         = sizeof(int),
 749                 .mode           = 0644,
 750                 .proc_handler   = proc_dointvec
 751         },
 752 #ifdef CONFIG_IP_MULTICAST
 753         {
 754                 .procname       = "igmp_qrv",
 755                 .data           = &init_net.ipv4.sysctl_igmp_qrv,
 756                 .maxlen         = sizeof(int),
 757                 .mode           = 0644,
 758                 .proc_handler   = proc_dointvec_minmax,
 759                 .extra1         = &one
 760         },
 761 #endif
 762         {
 763                 .procname       = "tcp_congestion_control",
 764                 .data           = &init_net.ipv4.tcp_congestion_control,
 765                 .mode           = 0644,
 766                 .maxlen         = TCP_CA_NAME_MAX,
 767                 .proc_handler   = proc_tcp_congestion_control,
 768         },
 769         {
 770                 .procname       = "tcp_keepalive_time",
 771                 .data           = &init_net.ipv4.sysctl_tcp_keepalive_time,
 772                 .maxlen         = sizeof(int),
 773                 .mode           = 0644,
 774                 .proc_handler   = proc_dointvec_jiffies,
 775         },
 776         {
 777                 .procname       = "tcp_keepalive_probes",
 778                 .data           = &init_net.ipv4.sysctl_tcp_keepalive_probes,
 779                 .maxlen         = sizeof(int),
 780                 .mode           = 0644,
 781                 .proc_handler   = proc_dointvec
 782         },
 783         {
 784                 .procname       = "tcp_keepalive_intvl",
 785                 .data           = &init_net.ipv4.sysctl_tcp_keepalive_intvl,
 786                 .maxlen         = sizeof(int),
 787                 .mode           = 0644,
 788                 .proc_handler   = proc_dointvec_jiffies,
 789         },
 790         {
 791                 .procname       = "tcp_syn_retries",
 792                 .data           = &init_net.ipv4.sysctl_tcp_syn_retries,
 793                 .maxlen         = sizeof(int),
 794                 .mode           = 0644,
 795                 .proc_handler   = proc_dointvec_minmax,
 796                 .extra1         = &tcp_syn_retries_min,
 797                 .extra2         = &tcp_syn_retries_max
 798         },
 799         {
 800                 .procname       = "tcp_synack_retries",
 801                 .data           = &init_net.ipv4.sysctl_tcp_synack_retries,
 802                 .maxlen         = sizeof(int),
 803                 .mode           = 0644,
 804                 .proc_handler   = proc_dointvec
 805         },
 806 #ifdef CONFIG_SYN_COOKIES
 807         {
 808                 .procname       = "tcp_syncookies",
 809                 .data           = &init_net.ipv4.sysctl_tcp_syncookies,
 810                 .maxlen         = sizeof(int),
 811                 .mode           = 0644,
 812                 .proc_handler   = proc_dointvec
 813         },
 814 #endif
 815         {
 816                 .procname       = "tcp_reordering",
 817                 .data           = &init_net.ipv4.sysctl_tcp_reordering,
 818                 .maxlen         = sizeof(int),
 819                 .mode           = 0644,
 820                 .proc_handler   = proc_dointvec
 821         },
 822         {
 823                 .procname       = "tcp_retries1",
 824                 .data           = &init_net.ipv4.sysctl_tcp_retries1,
 825                 .maxlen         = sizeof(int),
 826                 .mode           = 0644,
 827                 .proc_handler   = proc_dointvec_minmax,
 828                 .extra2         = &tcp_retr1_max
 829         },
 830         {
 831                 .procname       = "tcp_retries2",
 832                 .data           = &init_net.ipv4.sysctl_tcp_retries2,
 833                 .maxlen         = sizeof(int),
 834                 .mode           = 0644,
 835                 .proc_handler   = proc_dointvec
 836         },
 837         {
 838                 .procname       = "tcp_orphan_retries",
 839                 .data           = &init_net.ipv4.sysctl_tcp_orphan_retries,
 840                 .maxlen         = sizeof(int),
 841                 .mode           = 0644,
 842                 .proc_handler   = proc_dointvec
 843         },
 844         {
 845                 .procname       = "tcp_fin_timeout",
 846                 .data           = &init_net.ipv4.sysctl_tcp_fin_timeout,
 847                 .maxlen         = sizeof(int),
 848                 .mode           = 0644,
 849                 .proc_handler   = proc_dointvec_jiffies,
 850         },
 851         {
 852                 .procname       = "tcp_notsent_lowat",
 853                 .data           = &init_net.ipv4.sysctl_tcp_notsent_lowat,
 854                 .maxlen         = sizeof(unsigned int),
 855                 .mode           = 0644,
 856                 .proc_handler   = proc_douintvec,
 857         },
 858         {
 859                 .procname       = "tcp_tw_reuse",
 860                 .data           = &init_net.ipv4.sysctl_tcp_tw_reuse,
 861                 .maxlen         = sizeof(int),
 862                 .mode           = 0644,
 863                 .proc_handler   = proc_dointvec
 864         },
 865         {
 866                 .procname       = "tcp_max_tw_buckets",
 867                 .data           = &init_net.ipv4.tcp_death_row.sysctl_max_tw_buckets,
 868                 .maxlen         = sizeof(int),
 869                 .mode           = 0644,
 870                 .proc_handler   = proc_dointvec
 871         },
 872         {
 873                 .procname       = "tcp_max_syn_backlog",
 874                 .data           = &init_net.ipv4.sysctl_max_syn_backlog,
 875                 .maxlen         = sizeof(int),
 876                 .mode           = 0644,
 877                 .proc_handler   = proc_dointvec
 878         },
 879         {
 880                 .procname       = "tcp_fastopen",
 881                 .data           = &init_net.ipv4.sysctl_tcp_fastopen,
 882                 .maxlen         = sizeof(int),
 883                 .mode           = 0644,
 884                 .proc_handler   = proc_dointvec,
 885         },
 886         {
 887                 .procname       = "tcp_fastopen_key",
 888                 .mode           = 0600,
 889                 .data           = &init_net.ipv4.sysctl_tcp_fastopen,
 890                 .maxlen         = ((TCP_FASTOPEN_KEY_LENGTH * 2) + 10),
 891                 .proc_handler   = proc_tcp_fastopen_key,
 892         },
 893         {
 894                 .procname       = "tcp_fastopen_blackhole_timeout_sec",
 895                 .data           = &init_net.ipv4.sysctl_tcp_fastopen_blackhole_timeout,
 896                 .maxlen         = sizeof(int),
 897                 .mode           = 0644,
 898                 .proc_handler   = proc_tfo_blackhole_detect_timeout,
 899                 .extra1         = &zero,
 900         },
 901 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 902         {
 903                 .procname       = "fib_multipath_use_neigh",
 904                 .data           = &init_net.ipv4.sysctl_fib_multipath_use_neigh,
 905                 .maxlen         = sizeof(int),
 906                 .mode           = 0644,
 907                 .proc_handler   = proc_dointvec_minmax,
 908                 .extra1         = &zero,
 909                 .extra2         = &one,
 910         },
 911         {
 912                 .procname       = "fib_multipath_hash_policy",
 913                 .data           = &init_net.ipv4.sysctl_fib_multipath_hash_policy,
 914                 .maxlen         = sizeof(int),
 915                 .mode           = 0644,
 916                 .proc_handler   = proc_fib_multipath_hash_policy,
 917                 .extra1         = &zero,
 918                 .extra2         = &one,
 919         },
 920 #endif
 921         {
 922                 .procname       = "ip_unprivileged_port_start",
 923                 .maxlen         = sizeof(int),
 924                 .data           = &init_net.ipv4.sysctl_ip_prot_sock,
 925                 .mode           = 0644,
 926                 .proc_handler   = ipv4_privileged_ports,
 927         },
 928 #ifdef CONFIG_NET_L3_MASTER_DEV
 929         {
 930                 .procname       = "udp_l3mdev_accept",
 931                 .data           = &init_net.ipv4.sysctl_udp_l3mdev_accept,
 932                 .maxlen         = sizeof(int),
 933                 .mode           = 0644,
 934                 .proc_handler   = proc_dointvec_minmax,
 935                 .extra1         = &zero,
 936                 .extra2         = &one,
 937         },
 938 #endif
 939         {
 940                 .procname       = "tcp_sack",
 941                 .data           = &init_net.ipv4.sysctl_tcp_sack,
 942                 .maxlen         = sizeof(int),
 943                 .mode           = 0644,
 944                 .proc_handler   = proc_dointvec
 945         },
 946         {
 947                 .procname       = "tcp_window_scaling",
 948                 .data           = &init_net.ipv4.sysctl_tcp_window_scaling,
 949                 .maxlen         = sizeof(int),
 950                 .mode           = 0644,
 951                 .proc_handler   = proc_dointvec
 952         },
 953         {
 954                 .procname       = "tcp_timestamps",
 955                 .data           = &init_net.ipv4.sysctl_tcp_timestamps,
 956                 .maxlen         = sizeof(int),
 957                 .mode           = 0644,
 958                 .proc_handler   = proc_dointvec
 959         },
 960         {
 961                 .procname       = "tcp_early_retrans",
 962                 .data           = &init_net.ipv4.sysctl_tcp_early_retrans,
 963                 .maxlen         = sizeof(int),
 964                 .mode           = 0644,
 965                 .proc_handler   = proc_dointvec_minmax,
 966                 .extra1         = &zero,
 967                 .extra2         = &four,
 968         },
 969         {
 970                 .procname       = "tcp_recovery",
 971                 .data           = &init_net.ipv4.sysctl_tcp_recovery,
 972                 .maxlen         = sizeof(int),
 973                 .mode           = 0644,
 974                 .proc_handler   = proc_dointvec,
 975         },
 976         {
 977                 .procname       = "tcp_thin_linear_timeouts",
 978                 .data           = &init_net.ipv4.sysctl_tcp_thin_linear_timeouts,
 979                 .maxlen         = sizeof(int),
 980                 .mode           = 0644,
 981                 .proc_handler   = proc_dointvec
 982         },
 983         {
 984                 .procname       = "tcp_slow_start_after_idle",
 985                 .data           = &init_net.ipv4.sysctl_tcp_slow_start_after_idle,
 986                 .maxlen         = sizeof(int),
 987                 .mode           = 0644,
 988                 .proc_handler   = proc_dointvec
 989         },
 990         {
 991                 .procname       = "tcp_retrans_collapse",
 992                 .data           = &init_net.ipv4.sysctl_tcp_retrans_collapse,
 993                 .maxlen         = sizeof(int),
 994                 .mode           = 0644,
 995                 .proc_handler   = proc_dointvec
 996         },
 997         {
 998                 .procname       = "tcp_stdurg",
 999                 .data           = &init_net.ipv4.sysctl_tcp_stdurg,
1000                 .maxlen         = sizeof(int),
1001                 .mode           = 0644,
1002                 .proc_handler   = proc_dointvec
1003         },
1004         {
1005                 .procname       = "tcp_rfc1337",
1006                 .data           = &init_net.ipv4.sysctl_tcp_rfc1337,
1007                 .maxlen         = sizeof(int),
1008                 .mode           = 0644,
1009                 .proc_handler   = proc_dointvec
1010         },
1011         {
1012                 .procname       = "tcp_abort_on_overflow",
1013                 .data           = &init_net.ipv4.sysctl_tcp_abort_on_overflow,
1014                 .maxlen         = sizeof(int),
1015                 .mode           = 0644,
1016                 .proc_handler   = proc_dointvec
1017         },
1018         {
1019                 .procname       = "tcp_fack",
1020                 .data           = &init_net.ipv4.sysctl_tcp_fack,
1021                 .maxlen         = sizeof(int),
1022                 .mode           = 0644,
1023                 .proc_handler   = proc_dointvec
1024         },
1025         {
1026                 .procname       = "tcp_max_reordering",
1027                 .data           = &init_net.ipv4.sysctl_tcp_max_reordering,
1028                 .maxlen         = sizeof(int),
1029                 .mode           = 0644,
1030                 .proc_handler   = proc_dointvec
1031         },
1032         {
1033                 .procname       = "tcp_dsack",
1034                 .data           = &init_net.ipv4.sysctl_tcp_dsack,
1035                 .maxlen         = sizeof(int),
1036                 .mode           = 0644,
1037                 .proc_handler   = proc_dointvec
1038         },
1039         {
1040                 .procname       = "tcp_app_win",
1041                 .data           = &init_net.ipv4.sysctl_tcp_app_win,
1042                 .maxlen         = sizeof(int),
1043                 .mode           = 0644,
1044                 .proc_handler   = proc_dointvec
1045         },
1046         {
1047                 .procname       = "tcp_adv_win_scale",
1048                 .data           = &init_net.ipv4.sysctl_tcp_adv_win_scale,
1049                 .maxlen         = sizeof(int),
1050                 .mode           = 0644,
1051                 .proc_handler   = proc_dointvec_minmax,
1052                 .extra1         = &tcp_adv_win_scale_min,
1053                 .extra2         = &tcp_adv_win_scale_max,
1054         },
1055         {
1056                 .procname       = "tcp_frto",
1057                 .data           = &init_net.ipv4.sysctl_tcp_frto,
1058                 .maxlen         = sizeof(int),
1059                 .mode           = 0644,
1060                 .proc_handler   = proc_dointvec
1061         },
1062         {
1063                 .procname       = "tcp_no_metrics_save",
1064                 .data           = &init_net.ipv4.sysctl_tcp_nometrics_save,
1065                 .maxlen         = sizeof(int),
1066                 .mode           = 0644,
1067                 .proc_handler   = proc_dointvec,
1068         },
1069         {
1070                 .procname       = "tcp_moderate_rcvbuf",
1071                 .data           = &init_net.ipv4.sysctl_tcp_moderate_rcvbuf,
1072                 .maxlen         = sizeof(int),
1073                 .mode           = 0644,
1074                 .proc_handler   = proc_dointvec,
1075         },
1076         {
1077                 .procname       = "tcp_tso_win_divisor",
1078                 .data           = &init_net.ipv4.sysctl_tcp_tso_win_divisor,
1079                 .maxlen         = sizeof(int),
1080                 .mode           = 0644,
1081                 .proc_handler   = proc_dointvec,
1082         },
1083         {
1084                 .procname       = "tcp_workaround_signed_windows",
1085                 .data           = &init_net.ipv4.sysctl_tcp_workaround_signed_windows,
1086                 .maxlen         = sizeof(int),
1087                 .mode           = 0644,
1088                 .proc_handler   = proc_dointvec
1089         },
1090         {
1091                 .procname       = "tcp_limit_output_bytes",
1092                 .data           = &init_net.ipv4.sysctl_tcp_limit_output_bytes,
1093                 .maxlen         = sizeof(int),
1094                 .mode           = 0644,
1095                 .proc_handler   = proc_dointvec
1096         },
1097         {
1098                 .procname       = "tcp_challenge_ack_limit",
1099                 .data           = &init_net.ipv4.sysctl_tcp_challenge_ack_limit,
1100                 .maxlen         = sizeof(int),
1101                 .mode           = 0644,
1102                 .proc_handler   = proc_dointvec
1103         },
1104         {
1105                 .procname       = "tcp_min_tso_segs",
1106                 .data           = &init_net.ipv4.sysctl_tcp_min_tso_segs,
1107                 .maxlen         = sizeof(int),
1108                 .mode           = 0644,
1109                 .proc_handler   = proc_dointvec_minmax,
1110                 .extra1         = &one,
1111                 .extra2         = &gso_max_segs,
1112         },
1113         {
1114                 .procname       = "tcp_min_rtt_wlen",
1115                 .data           = &init_net.ipv4.sysctl_tcp_min_rtt_wlen,
1116                 .maxlen         = sizeof(int),
1117                 .mode           = 0644,
1118                 .proc_handler   = proc_dointvec
1119         },
1120         {
1121                 .procname       = "tcp_autocorking",
1122                 .data           = &init_net.ipv4.sysctl_tcp_autocorking,
1123                 .maxlen         = sizeof(int),
1124                 .mode           = 0644,
1125                 .proc_handler   = proc_dointvec_minmax,
1126                 .extra1         = &zero,
1127                 .extra2         = &one,
1128         },
1129         {
1130                 .procname       = "tcp_invalid_ratelimit",
1131                 .data           = &init_net.ipv4.sysctl_tcp_invalid_ratelimit,
1132                 .maxlen         = sizeof(int),
1133                 .mode           = 0644,
1134                 .proc_handler   = proc_dointvec_ms_jiffies,
1135         },
1136         {
1137                 .procname       = "tcp_pacing_ss_ratio",
1138                 .data           = &init_net.ipv4.sysctl_tcp_pacing_ss_ratio,
1139                 .maxlen         = sizeof(int),
1140                 .mode           = 0644,
1141                 .proc_handler   = proc_dointvec_minmax,
1142                 .extra1         = &zero,
1143                 .extra2         = &thousand,
1144         },
1145         {
1146                 .procname       = "tcp_pacing_ca_ratio",
1147                 .data           = &init_net.ipv4.sysctl_tcp_pacing_ca_ratio,
1148                 .maxlen         = sizeof(int),
1149                 .mode           = 0644,
1150                 .proc_handler   = proc_dointvec_minmax,
1151                 .extra1         = &zero,
1152                 .extra2         = &thousand,
1153         },
1154         {
1155                 .procname       = "tcp_wmem",
1156                 .data           = &init_net.ipv4.sysctl_tcp_wmem,
1157                 .maxlen         = sizeof(init_net.ipv4.sysctl_tcp_wmem),
1158                 .mode           = 0644,
1159                 .proc_handler   = proc_dointvec_minmax,
1160                 .extra1         = &one,
1161         },
1162         {
1163                 .procname       = "tcp_rmem",
1164                 .data           = &init_net.ipv4.sysctl_tcp_rmem,
1165                 .maxlen         = sizeof(init_net.ipv4.sysctl_tcp_rmem),
1166                 .mode           = 0644,
1167                 .proc_handler   = proc_dointvec_minmax,
1168                 .extra1         = &one,
1169         },
1170         { }
1171 };
1172
1173 static __net_init int ipv4_sysctl_init_net(struct net *net)
1174 {
1175         struct ctl_table *table;
1176
1177         table = ipv4_net_table;
1178         if (!net_eq(net, &init_net)) {
1179                 int i;
1180
1181                 table = kmemdup(table, sizeof(ipv4_net_table), GFP_KERNEL);
1182                 if (!table)
1183                         goto err_alloc;
1184
1185                 /* Update the variables to point into the current struct net */
1186                 for (i = 0; i < ARRAY_SIZE(ipv4_net_table) - 1; i++)
1187                         table[i].data += (void *)net - (void *)&init_net;
1188         }
1189
1190         net->ipv4.ipv4_hdr = register_net_sysctl(net, "net/ipv4", table);
1191         if (!net->ipv4.ipv4_hdr)
1192                 goto err_reg;
1193
1194         net->ipv4.sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1195         if (!net->ipv4.sysctl_local_reserved_ports)
1196                 goto err_ports;
1197
1198         return 0;
1199
1200 err_ports:
1201         unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
1202 err_reg:
1203         if (!net_eq(net, &init_net))
1204                 kfree(table);
1205 err_alloc:
1206         return -ENOMEM;
1207 }
1208
1209 static __net_exit void ipv4_sysctl_exit_net(struct net *net)
1210 {
1211         struct ctl_table *table;
1212
1213         kfree(net->ipv4.sysctl_local_reserved_ports);
1214         table = net->ipv4.ipv4_hdr->ctl_table_arg;
1215         unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
1216         kfree(table);
1217 }
1218
1219 static __net_initdata struct pernet_operations ipv4_sysctl_ops = {
1220         .init = ipv4_sysctl_init_net,
1221         .exit = ipv4_sysctl_exit_net,
1222 };
1223
1224 static __init int sysctl_ipv4_init(void)
1225 {
1226         struct ctl_table_header *hdr;
1227
1228         hdr = register_net_sysctl(&init_net, "net/ipv4", ipv4_table);
1229         if (!hdr)
1230                 return -ENOMEM;
1231
1232         if (register_pernet_subsys(&ipv4_sysctl_ops)) {
1233                 unregister_net_sysctl_table(hdr);
1234                 return -ENOMEM;
1235         }
1236
1237         return 0;
1238 }
1239
1240 __initcall(sysctl_ipv4_init);