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