net/ipv4/sysctl_net_ipv4.c

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