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         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         int ret;
 359
 360         ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 361         if (write && ret == 0)
 362                 tcp_fastopen_active_timeout_reset();
 363
 364         return ret;
 365 }
 366
 367 static int proc_tcp_available_ulp(struct ctl_table *ctl,
 368                                   int write,
 369                                   void __user *buffer, size_t *lenp,
 370                                   loff_t *ppos)
 371 {
 372         struct ctl_table tbl = { .maxlen = TCP_ULP_BUF_MAX, };
 373         int ret;
 374
 375         tbl.data = kmalloc(tbl.maxlen, GFP_USER);
 376         if (!tbl.data)
 377                 return -ENOMEM;
 378         tcp_get_available_ulp(tbl.data, TCP_ULP_BUF_MAX);
 379         ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
 380         kfree(tbl.data);
 381
 382         return ret;
 383 }
 384
 385 static struct ctl_table ipv4_table[] = {
 386         {
 387                 .procname       = "tcp_retrans_collapse",
 388                 .data           = &sysctl_tcp_retrans_collapse,
 389                 .maxlen         = sizeof(int),
 390                 .mode           = 0644,
 391                 .proc_handler   = proc_dointvec
 392         },
 393         {
 394                 .procname       = "tcp_max_orphans",
 395                 .data           = &sysctl_tcp_max_orphans,
 396                 .maxlen         = sizeof(int),
 397                 .mode           = 0644,
 398                 .proc_handler   = proc_dointvec
 399         },
 400         {
 401                 .procname       = "tcp_fastopen",
 402                 .data           = &sysctl_tcp_fastopen,
 403                 .maxlen         = sizeof(int),
 404                 .mode           = 0644,
 405                 .proc_handler   = proc_dointvec,
 406         },
 407         {
 408                 .procname       = "tcp_fastopen_key",
 409                 .mode           = 0600,
 410                 .maxlen         = ((TCP_FASTOPEN_KEY_LENGTH * 2) + 10),
 411                 .proc_handler   = proc_tcp_fastopen_key,
 412         },
 413         {
 414                 .procname       = "tcp_fastopen_blackhole_timeout_sec",
 415                 .data           = &sysctl_tcp_fastopen_blackhole_timeout,
 416                 .maxlen         = sizeof(int),
 417                 .mode           = 0644,
 418                 .proc_handler   = proc_tfo_blackhole_detect_timeout,
 419                 .extra1         = &zero,
 420         },
 421         {
 422                 .procname       = "tcp_abort_on_overflow",
 423                 .data           = &sysctl_tcp_abort_on_overflow,
 424                 .maxlen         = sizeof(int),
 425                 .mode           = 0644,
 426                 .proc_handler   = proc_dointvec
 427         },
 428         {
 429                 .procname       = "tcp_stdurg",
 430                 .data           = &sysctl_tcp_stdurg,
 431                 .maxlen         = sizeof(int),
 432                 .mode           = 0644,
 433                 .proc_handler   = proc_dointvec
 434         },
 435         {
 436                 .procname       = "tcp_rfc1337",
 437                 .data           = &sysctl_tcp_rfc1337,
 438                 .maxlen         = sizeof(int),
 439                 .mode           = 0644,
 440                 .proc_handler   = proc_dointvec
 441         },
 442         {
 443                 .procname       = "inet_peer_threshold",
 444                 .data           = &inet_peer_threshold,
 445                 .maxlen         = sizeof(int),
 446                 .mode           = 0644,
 447                 .proc_handler   = proc_dointvec
 448         },
 449         {
 450                 .procname       = "inet_peer_minttl",
 451                 .data           = &inet_peer_minttl,
 452                 .maxlen         = sizeof(int),
 453                 .mode           = 0644,
 454                 .proc_handler   = proc_dointvec_jiffies,
 455         },
 456         {
 457                 .procname       = "inet_peer_maxttl",
 458                 .data           = &inet_peer_maxttl,
 459                 .maxlen         = sizeof(int),
 460                 .mode           = 0644,
 461                 .proc_handler   = proc_dointvec_jiffies,
 462         },
 463         {
 464                 .procname       = "tcp_fack",
 465                 .data           = &sysctl_tcp_fack,
 466                 .maxlen         = sizeof(int),
 467                 .mode           = 0644,
 468                 .proc_handler   = proc_dointvec
 469         },
 470         {
 471                 .procname       = "tcp_recovery",
 472                 .data           = &sysctl_tcp_recovery,
 473                 .maxlen         = sizeof(int),
 474                 .mode           = 0644,
 475                 .proc_handler   = proc_dointvec,
 476         },
 477         {
 478                 .procname       = "tcp_max_reordering",
 479                 .data           = &sysctl_tcp_max_reordering,
 480                 .maxlen         = sizeof(int),
 481                 .mode           = 0644,
 482                 .proc_handler   = proc_dointvec
 483         },
 484         {
 485                 .procname       = "tcp_dsack",
 486                 .data           = &sysctl_tcp_dsack,
 487                 .maxlen         = sizeof(int),
 488                 .mode           = 0644,
 489                 .proc_handler   = proc_dointvec
 490         },
 491         {
 492                 .procname       = "tcp_mem",
 493                 .maxlen         = sizeof(sysctl_tcp_mem),
 494                 .data           = &sysctl_tcp_mem,
 495                 .mode           = 0644,
 496                 .proc_handler   = proc_doulongvec_minmax,
 497         },
 498         {
 499                 .procname       = "tcp_wmem",
 500                 .data           = &sysctl_tcp_wmem,
 501                 .maxlen         = sizeof(sysctl_tcp_wmem),
 502                 .mode           = 0644,
 503                 .proc_handler   = proc_dointvec_minmax,
 504                 .extra1         = &one,
 505         },
 506         {
 507                 .procname       = "tcp_rmem",
 508                 .data           = &sysctl_tcp_rmem,
 509                 .maxlen         = sizeof(sysctl_tcp_rmem),
 510                 .mode           = 0644,
 511                 .proc_handler   = proc_dointvec_minmax,
 512                 .extra1         = &one,
 513         },
 514         {
 515                 .procname       = "tcp_app_win",
 516                 .data           = &sysctl_tcp_app_win,
 517                 .maxlen         = sizeof(int),
 518                 .mode           = 0644,
 519                 .proc_handler   = proc_dointvec
 520         },
 521         {
 522                 .procname       = "tcp_adv_win_scale",
 523                 .data           = &sysctl_tcp_adv_win_scale,
 524                 .maxlen         = sizeof(int),
 525                 .mode           = 0644,
 526                 .proc_handler   = proc_dointvec_minmax,
 527                 .extra1         = &tcp_adv_win_scale_min,
 528                 .extra2         = &tcp_adv_win_scale_max,
 529         },
 530         {
 531                 .procname       = "tcp_frto",
 532                 .data           = &sysctl_tcp_frto,
 533                 .maxlen         = sizeof(int),
 534                 .mode           = 0644,
 535                 .proc_handler   = proc_dointvec
 536         },
 537         {
 538                 .procname       = "tcp_min_rtt_wlen",
 539                 .data           = &sysctl_tcp_min_rtt_wlen,
 540                 .maxlen         = sizeof(int),
 541                 .mode           = 0644,
 542                 .proc_handler   = proc_dointvec
 543         },
 544         {
 545                 .procname       = "tcp_low_latency",
 546                 .data           = &sysctl_tcp_low_latency,
 547                 .maxlen         = sizeof(int),
 548                 .mode           = 0644,
 549                 .proc_handler   = proc_dointvec
 550         },
 551         {
 552                 .procname       = "tcp_no_metrics_save",
 553                 .data           = &sysctl_tcp_nometrics_save,
 554                 .maxlen         = sizeof(int),
 555                 .mode           = 0644,
 556                 .proc_handler   = proc_dointvec,
 557         },
 558         {
 559                 .procname       = "tcp_moderate_rcvbuf",
 560                 .data           = &sysctl_tcp_moderate_rcvbuf,
 561                 .maxlen         = sizeof(int),
 562                 .mode           = 0644,
 563                 .proc_handler   = proc_dointvec,
 564         },
 565         {
 566                 .procname       = "tcp_tso_win_divisor",
 567                 .data           = &sysctl_tcp_tso_win_divisor,
 568                 .maxlen         = sizeof(int),
 569                 .mode           = 0644,
 570                 .proc_handler   = proc_dointvec,
 571         },
 572         {
 573                 .procname       = "tcp_congestion_control",
 574                 .mode           = 0644,
 575                 .maxlen         = TCP_CA_NAME_MAX,
 576                 .proc_handler   = proc_tcp_congestion_control,
 577         },
 578         {
 579                 .procname       = "tcp_workaround_signed_windows",
 580                 .data           = &sysctl_tcp_workaround_signed_windows,
 581                 .maxlen         = sizeof(int),
 582                 .mode           = 0644,
 583                 .proc_handler   = proc_dointvec
 584         },
 585         {
 586                 .procname       = "tcp_limit_output_bytes",
 587                 .data           = &sysctl_tcp_limit_output_bytes,
 588                 .maxlen         = sizeof(int),
 589                 .mode           = 0644,
 590                 .proc_handler   = proc_dointvec
 591         },
 592         {
 593                 .procname       = "tcp_challenge_ack_limit",
 594                 .data           = &sysctl_tcp_challenge_ack_limit,
 595                 .maxlen         = sizeof(int),
 596                 .mode           = 0644,
 597                 .proc_handler   = proc_dointvec
 598         },
 599         {
 600                 .procname       = "tcp_slow_start_after_idle",
 601                 .data           = &sysctl_tcp_slow_start_after_idle,
 602                 .maxlen         = sizeof(int),
 603                 .mode           = 0644,
 604                 .proc_handler   = proc_dointvec
 605         },
 606 #ifdef CONFIG_NETLABEL
 607         {
 608                 .procname       = "cipso_cache_enable",
 609                 .data           = &cipso_v4_cache_enabled,
 610                 .maxlen         = sizeof(int),
 611                 .mode           = 0644,
 612                 .proc_handler   = proc_dointvec,
 613         },
 614         {
 615                 .procname       = "cipso_cache_bucket_size",
 616                 .data           = &cipso_v4_cache_bucketsize,
 617                 .maxlen         = sizeof(int),
 618                 .mode           = 0644,
 619                 .proc_handler   = proc_dointvec,
 620         },
 621         {
 622                 .procname       = "cipso_rbm_optfmt",
 623                 .data           = &cipso_v4_rbm_optfmt,
 624                 .maxlen         = sizeof(int),
 625                 .mode           = 0644,
 626                 .proc_handler   = proc_dointvec,
 627         },
 628         {
 629                 .procname       = "cipso_rbm_strictvalid",
 630                 .data           = &cipso_v4_rbm_strictvalid,
 631                 .maxlen         = sizeof(int),
 632                 .mode           = 0644,
 633                 .proc_handler   = proc_dointvec,
 634         },
 635 #endif /* CONFIG_NETLABEL */
 636         {
 637                 .procname       = "tcp_available_congestion_control",
 638                 .maxlen         = TCP_CA_BUF_MAX,
 639                 .mode           = 0444,
 640                 .proc_handler   = proc_tcp_available_congestion_control,
 641         },
 642         {
 643                 .procname       = "tcp_allowed_congestion_control",
 644                 .maxlen         = TCP_CA_BUF_MAX,
 645                 .mode           = 0644,
 646                 .proc_handler   = proc_allowed_congestion_control,
 647         },
 648         {
 649                 .procname       = "tcp_thin_linear_timeouts",
 650                 .data           = &sysctl_tcp_thin_linear_timeouts,
 651                 .maxlen         = sizeof(int),
 652                 .mode           = 0644,
 653                 .proc_handler   = proc_dointvec
 654         },
 655         {
 656                 .procname       = "tcp_early_retrans",
 657                 .data           = &sysctl_tcp_early_retrans,
 658                 .maxlen         = sizeof(int),
 659                 .mode           = 0644,
 660                 .proc_handler   = proc_dointvec_minmax,
 661                 .extra1         = &zero,
 662                 .extra2         = &four,
 663         },
 664         {
 665                 .procname       = "tcp_min_tso_segs",
 666                 .data           = &sysctl_tcp_min_tso_segs,
 667                 .maxlen         = sizeof(int),
 668                 .mode           = 0644,
 669                 .proc_handler   = proc_dointvec_minmax,
 670                 .extra1         = &one,
 671                 .extra2         = &gso_max_segs,
 672         },
 673         {
 674                 .procname       = "tcp_pacing_ss_ratio",
 675                 .data           = &sysctl_tcp_pacing_ss_ratio,
 676                 .maxlen         = sizeof(int),
 677                 .mode           = 0644,
 678                 .proc_handler   = proc_dointvec_minmax,
 679                 .extra1         = &zero,
 680                 .extra2         = &thousand,
 681         },
 682         {
 683                 .procname       = "tcp_pacing_ca_ratio",
 684                 .data           = &sysctl_tcp_pacing_ca_ratio,
 685                 .maxlen         = sizeof(int),
 686                 .mode           = 0644,
 687                 .proc_handler   = proc_dointvec_minmax,
 688                 .extra1         = &zero,
 689                 .extra2         = &thousand,
 690         },
 691         {
 692                 .procname       = "tcp_autocorking",
 693                 .data           = &sysctl_tcp_autocorking,
 694                 .maxlen         = sizeof(int),
 695                 .mode           = 0644,
 696                 .proc_handler   = proc_dointvec_minmax,
 697                 .extra1         = &zero,
 698                 .extra2         = &one,
 699         },
 700         {
 701                 .procname       = "tcp_invalid_ratelimit",
 702                 .data           = &sysctl_tcp_invalid_ratelimit,
 703                 .maxlen         = sizeof(int),
 704                 .mode           = 0644,
 705                 .proc_handler   = proc_dointvec_ms_jiffies,
 706         },
 707         {
 708                 .procname       = "tcp_available_ulp",
 709                 .maxlen         = TCP_ULP_BUF_MAX,
 710                 .mode           = 0444,
 711                 .proc_handler   = proc_tcp_available_ulp,
 712         },
 713         {
 714                 .procname       = "icmp_msgs_per_sec",
 715                 .data           = &sysctl_icmp_msgs_per_sec,
 716                 .maxlen         = sizeof(int),
 717                 .mode           = 0644,
 718                 .proc_handler   = proc_dointvec_minmax,
 719                 .extra1         = &zero,
 720         },
 721         {
 722                 .procname       = "icmp_msgs_burst",
 723                 .data           = &sysctl_icmp_msgs_burst,
 724                 .maxlen         = sizeof(int),
 725                 .mode           = 0644,
 726                 .proc_handler   = proc_dointvec_minmax,
 727                 .extra1         = &zero,
 728         },
 729         {
 730                 .procname       = "udp_mem",
 731                 .data           = &sysctl_udp_mem,
 732                 .maxlen         = sizeof(sysctl_udp_mem),
 733                 .mode           = 0644,
 734                 .proc_handler   = proc_doulongvec_minmax,
 735         },
 736         {
 737                 .procname       = "udp_rmem_min",
 738                 .data           = &sysctl_udp_rmem_min,
 739                 .maxlen         = sizeof(sysctl_udp_rmem_min),
 740                 .mode           = 0644,
 741                 .proc_handler   = proc_dointvec_minmax,
 742                 .extra1         = &one
 743         },
 744         {
 745                 .procname       = "udp_wmem_min",
 746                 .data           = &sysctl_udp_wmem_min,
 747                 .maxlen         = sizeof(sysctl_udp_wmem_min),
 748                 .mode           = 0644,
 749                 .proc_handler   = proc_dointvec_minmax,
 750                 .extra1         = &one
 751         },
 752         { }
 753 };
 754
 755 static struct ctl_table ipv4_net_table[] = {
 756         {
 757                 .procname       = "icmp_echo_ignore_all",
 758                 .data           = &init_net.ipv4.sysctl_icmp_echo_ignore_all,
 759                 .maxlen         = sizeof(int),
 760                 .mode           = 0644,
 761                 .proc_handler   = proc_dointvec
 762         },
 763         {
 764                 .procname       = "icmp_echo_ignore_broadcasts",
 765                 .data           = &init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts,
 766                 .maxlen         = sizeof(int),
 767                 .mode           = 0644,
 768                 .proc_handler   = proc_dointvec
 769         },
 770         {
 771                 .procname       = "icmp_ignore_bogus_error_responses",
 772                 .data           = &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses,
 773                 .maxlen         = sizeof(int),
 774                 .mode           = 0644,
 775                 .proc_handler   = proc_dointvec
 776         },
 777         {
 778                 .procname       = "icmp_errors_use_inbound_ifaddr",
 779                 .data           = &init_net.ipv4.sysctl_icmp_errors_use_inbound_ifaddr,
 780                 .maxlen         = sizeof(int),
 781                 .mode           = 0644,
 782                 .proc_handler   = proc_dointvec
 783         },
 784         {
 785                 .procname       = "icmp_ratelimit",
 786                 .data           = &init_net.ipv4.sysctl_icmp_ratelimit,
 787                 .maxlen         = sizeof(int),
 788                 .mode           = 0644,
 789                 .proc_handler   = proc_dointvec_ms_jiffies,
 790         },
 791         {
 792                 .procname       = "icmp_ratemask",
 793                 .data           = &init_net.ipv4.sysctl_icmp_ratemask,
 794                 .maxlen         = sizeof(int),
 795                 .mode           = 0644,
 796                 .proc_handler   = proc_dointvec
 797         },
 798         {
 799                 .procname       = "ping_group_range",
 800                 .data           = &init_net.ipv4.ping_group_range.range,
 801                 .maxlen         = sizeof(gid_t)*2,
 802                 .mode           = 0644,
 803                 .proc_handler   = ipv4_ping_group_range,
 804         },
 805         {
 806                 .procname       = "tcp_ecn",
 807                 .data           = &init_net.ipv4.sysctl_tcp_ecn,
 808                 .maxlen         = sizeof(int),
 809                 .mode           = 0644,
 810                 .proc_handler   = proc_dointvec
 811         },
 812         {
 813                 .procname       = "tcp_ecn_fallback",
 814                 .data           = &init_net.ipv4.sysctl_tcp_ecn_fallback,
 815                 .maxlen         = sizeof(int),
 816                 .mode           = 0644,
 817                 .proc_handler   = proc_dointvec
 818         },
 819         {
 820                 .procname       = "ip_dynaddr",
 821                 .data           = &init_net.ipv4.sysctl_ip_dynaddr,
 822                 .maxlen         = sizeof(int),
 823                 .mode           = 0644,
 824                 .proc_handler   = proc_dointvec
 825         },
 826         {
 827                 .procname       = "ip_early_demux",
 828                 .data           = &init_net.ipv4.sysctl_ip_early_demux,
 829                 .maxlen         = sizeof(int),
 830                 .mode           = 0644,
 831                 .proc_handler   = proc_dointvec
 832         },
 833         {
 834                 .procname       = "udp_early_demux",
 835                 .data           = &init_net.ipv4.sysctl_udp_early_demux,
 836                 .maxlen         = sizeof(int),
 837                 .mode           = 0644,
 838                 .proc_handler   = proc_udp_early_demux
 839         },
 840         {
 841                 .procname       = "tcp_early_demux",
 842                 .data           = &init_net.ipv4.sysctl_tcp_early_demux,
 843                 .maxlen         = sizeof(int),
 844                 .mode           = 0644,
 845                 .proc_handler   = proc_tcp_early_demux
 846         },
 847         {
 848                 .procname       = "ip_default_ttl",
 849                 .data           = &init_net.ipv4.sysctl_ip_default_ttl,
 850                 .maxlen         = sizeof(int),
 851                 .mode           = 0644,
 852                 .proc_handler   = proc_dointvec_minmax,
 853                 .extra1         = &ip_ttl_min,
 854                 .extra2         = &ip_ttl_max,
 855         },
 856         {
 857                 .procname       = "ip_local_port_range",
 858                 .maxlen         = sizeof(init_net.ipv4.ip_local_ports.range),
 859                 .data           = &init_net.ipv4.ip_local_ports.range,
 860                 .mode           = 0644,
 861                 .proc_handler   = ipv4_local_port_range,
 862         },
 863         {
 864                 .procname       = "ip_local_reserved_ports",
 865                 .data           = &init_net.ipv4.sysctl_local_reserved_ports,
 866                 .maxlen         = 65536,
 867                 .mode           = 0644,
 868                 .proc_handler   = proc_do_large_bitmap,
 869         },
 870         {
 871                 .procname       = "ip_no_pmtu_disc",
 872                 .data           = &init_net.ipv4.sysctl_ip_no_pmtu_disc,
 873                 .maxlen         = sizeof(int),
 874                 .mode           = 0644,
 875                 .proc_handler   = proc_dointvec
 876         },
 877         {
 878                 .procname       = "ip_forward_use_pmtu",
 879                 .data           = &init_net.ipv4.sysctl_ip_fwd_use_pmtu,
 880                 .maxlen         = sizeof(int),
 881                 .mode           = 0644,
 882                 .proc_handler   = proc_dointvec,
 883         },
 884         {
 885                 .procname       = "ip_nonlocal_bind",
 886                 .data           = &init_net.ipv4.sysctl_ip_nonlocal_bind,
 887                 .maxlen         = sizeof(int),
 888                 .mode           = 0644,
 889                 .proc_handler   = proc_dointvec
 890         },
 891         {
 892                 .procname       = "fwmark_reflect",
 893                 .data           = &init_net.ipv4.sysctl_fwmark_reflect,
 894                 .maxlen         = sizeof(int),
 895                 .mode           = 0644,
 896                 .proc_handler   = proc_dointvec,
 897         },
 898         {
 899                 .procname       = "tcp_fwmark_accept",
 900                 .data           = &init_net.ipv4.sysctl_tcp_fwmark_accept,
 901                 .maxlen         = sizeof(int),
 902                 .mode           = 0644,
 903                 .proc_handler   = proc_dointvec,
 904         },
 905 #ifdef CONFIG_NET_L3_MASTER_DEV
 906         {
 907                 .procname       = "tcp_l3mdev_accept",
 908                 .data           = &init_net.ipv4.sysctl_tcp_l3mdev_accept,
 909                 .maxlen         = sizeof(int),
 910                 .mode           = 0644,
 911                 .proc_handler   = proc_dointvec_minmax,
 912                 .extra1         = &zero,
 913                 .extra2         = &one,
 914         },
 915 #endif
 916         {
 917                 .procname       = "tcp_mtu_probing",
 918                 .data           = &init_net.ipv4.sysctl_tcp_mtu_probing,
 919                 .maxlen         = sizeof(int),
 920                 .mode           = 0644,
 921                 .proc_handler   = proc_dointvec,
 922         },
 923         {
 924                 .procname       = "tcp_base_mss",
 925                 .data           = &init_net.ipv4.sysctl_tcp_base_mss,
 926                 .maxlen         = sizeof(int),
 927                 .mode           = 0644,
 928                 .proc_handler   = proc_dointvec,
 929         },
 930         {
 931                 .procname       = "tcp_probe_threshold",
 932                 .data           = &init_net.ipv4.sysctl_tcp_probe_threshold,
 933                 .maxlen         = sizeof(int),
 934                 .mode           = 0644,
 935                 .proc_handler   = proc_dointvec,
 936         },
 937         {
 938                 .procname       = "tcp_probe_interval",
 939                 .data           = &init_net.ipv4.sysctl_tcp_probe_interval,
 940                 .maxlen         = sizeof(int),
 941                 .mode           = 0644,
 942                 .proc_handler   = proc_dointvec,
 943         },
 944         {
 945                 .procname       = "igmp_link_local_mcast_reports",
 946                 .data           = &init_net.ipv4.sysctl_igmp_llm_reports,
 947                 .maxlen         = sizeof(int),
 948                 .mode           = 0644,
 949                 .proc_handler   = proc_dointvec
 950         },
 951         {
 952                 .procname       = "igmp_max_memberships",
 953                 .data           = &init_net.ipv4.sysctl_igmp_max_memberships,
 954                 .maxlen         = sizeof(int),
 955                 .mode           = 0644,
 956                 .proc_handler   = proc_dointvec
 957         },
 958         {
 959                 .procname       = "igmp_max_msf",
 960                 .data           = &init_net.ipv4.sysctl_igmp_max_msf,
 961                 .maxlen         = sizeof(int),
 962                 .mode           = 0644,
 963                 .proc_handler   = proc_dointvec
 964         },
 965 #ifdef CONFIG_IP_MULTICAST
 966         {
 967                 .procname       = "igmp_qrv",
 968                 .data           = &init_net.ipv4.sysctl_igmp_qrv,
 969                 .maxlen         = sizeof(int),
 970                 .mode           = 0644,
 971                 .proc_handler   = proc_dointvec_minmax,
 972                 .extra1         = &one
 973         },
 974 #endif
 975         {
 976                 .procname       = "tcp_keepalive_time",
 977                 .data           = &init_net.ipv4.sysctl_tcp_keepalive_time,
 978                 .maxlen         = sizeof(int),
 979                 .mode           = 0644,
 980                 .proc_handler   = proc_dointvec_jiffies,
 981         },
 982         {
 983                 .procname       = "tcp_keepalive_probes",
 984                 .data           = &init_net.ipv4.sysctl_tcp_keepalive_probes,
 985                 .maxlen         = sizeof(int),
 986                 .mode           = 0644,
 987                 .proc_handler   = proc_dointvec
 988         },
 989         {
 990                 .procname       = "tcp_keepalive_intvl",
 991                 .data           = &init_net.ipv4.sysctl_tcp_keepalive_intvl,
 992                 .maxlen         = sizeof(int),
 993                 .mode           = 0644,
 994                 .proc_handler   = proc_dointvec_jiffies,
 995         },
 996         {
 997                 .procname       = "tcp_syn_retries",
 998                 .data           = &init_net.ipv4.sysctl_tcp_syn_retries,
 999                 .maxlen         = sizeof(int),
1000                 .mode           = 0644,
1001                 .proc_handler   = proc_dointvec_minmax,
1002                 .extra1         = &tcp_syn_retries_min,
1003                 .extra2         = &tcp_syn_retries_max
1004         },
1005         {
1006                 .procname       = "tcp_synack_retries",
1007                 .data           = &init_net.ipv4.sysctl_tcp_synack_retries,
1008                 .maxlen         = sizeof(int),
1009                 .mode           = 0644,
1010                 .proc_handler   = proc_dointvec
1011         },
1012 #ifdef CONFIG_SYN_COOKIES
1013         {
1014                 .procname       = "tcp_syncookies",
1015                 .data           = &init_net.ipv4.sysctl_tcp_syncookies,
1016                 .maxlen         = sizeof(int),
1017                 .mode           = 0644,
1018                 .proc_handler   = proc_dointvec
1019         },
1020 #endif
1021         {
1022                 .procname       = "tcp_reordering",
1023                 .data           = &init_net.ipv4.sysctl_tcp_reordering,
1024                 .maxlen         = sizeof(int),
1025                 .mode           = 0644,
1026                 .proc_handler   = proc_dointvec
1027         },
1028         {
1029                 .procname       = "tcp_retries1",
1030                 .data           = &init_net.ipv4.sysctl_tcp_retries1,
1031                 .maxlen         = sizeof(int),
1032                 .mode           = 0644,
1033                 .proc_handler   = proc_dointvec_minmax,
1034                 .extra2         = &tcp_retr1_max
1035         },
1036         {
1037                 .procname       = "tcp_retries2",
1038                 .data           = &init_net.ipv4.sysctl_tcp_retries2,
1039                 .maxlen         = sizeof(int),
1040                 .mode           = 0644,
1041                 .proc_handler   = proc_dointvec
1042         },
1043         {
1044                 .procname       = "tcp_orphan_retries",
1045                 .data           = &init_net.ipv4.sysctl_tcp_orphan_retries,
1046                 .maxlen         = sizeof(int),
1047                 .mode           = 0644,
1048                 .proc_handler   = proc_dointvec
1049         },
1050         {
1051                 .procname       = "tcp_fin_timeout",
1052                 .data           = &init_net.ipv4.sysctl_tcp_fin_timeout,
1053                 .maxlen         = sizeof(int),
1054                 .mode           = 0644,
1055                 .proc_handler   = proc_dointvec_jiffies,
1056         },
1057         {
1058                 .procname       = "tcp_notsent_lowat",
1059                 .data           = &init_net.ipv4.sysctl_tcp_notsent_lowat,
1060                 .maxlen         = sizeof(unsigned int),
1061                 .mode           = 0644,
1062                 .proc_handler   = proc_douintvec,
1063         },
1064         {
1065                 .procname       = "tcp_tw_reuse",
1066                 .data           = &init_net.ipv4.sysctl_tcp_tw_reuse,
1067                 .maxlen         = sizeof(int),
1068                 .mode           = 0644,
1069                 .proc_handler   = proc_dointvec
1070         },
1071         {
1072                 .procname       = "tcp_max_tw_buckets",
1073                 .data           = &init_net.ipv4.tcp_death_row.sysctl_max_tw_buckets,
1074                 .maxlen         = sizeof(int),
1075                 .mode           = 0644,
1076                 .proc_handler   = proc_dointvec
1077         },
1078         {
1079                 .procname       = "tcp_max_syn_backlog",
1080                 .data           = &init_net.ipv4.sysctl_max_syn_backlog,
1081                 .maxlen         = sizeof(int),
1082                 .mode           = 0644,
1083                 .proc_handler   = proc_dointvec
1084         },
1085 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1086         {
1087                 .procname       = "fib_multipath_use_neigh",
1088                 .data           = &init_net.ipv4.sysctl_fib_multipath_use_neigh,
1089                 .maxlen         = sizeof(int),
1090                 .mode           = 0644,
1091                 .proc_handler   = proc_dointvec_minmax,
1092                 .extra1         = &zero,
1093                 .extra2         = &one,
1094         },
1095         {
1096                 .procname       = "fib_multipath_hash_policy",
1097                 .data           = &init_net.ipv4.sysctl_fib_multipath_hash_policy,
1098                 .maxlen         = sizeof(int),
1099                 .mode           = 0644,
1100                 .proc_handler   = proc_dointvec_minmax,
1101                 .extra1         = &zero,
1102                 .extra2         = &one,
1103         },
1104 #endif
1105         {
1106                 .procname       = "ip_unprivileged_port_start",
1107                 .maxlen         = sizeof(int),
1108                 .data           = &init_net.ipv4.sysctl_ip_prot_sock,
1109                 .mode           = 0644,
1110                 .proc_handler   = ipv4_privileged_ports,
1111         },
1112 #ifdef CONFIG_NET_L3_MASTER_DEV
1113         {
1114                 .procname       = "udp_l3mdev_accept",
1115                 .data           = &init_net.ipv4.sysctl_udp_l3mdev_accept,
1116                 .maxlen         = sizeof(int),
1117                 .mode           = 0644,
1118                 .proc_handler   = proc_dointvec_minmax,
1119                 .extra1         = &zero,
1120                 .extra2         = &one,
1121         },
1122 #endif
1123         {
1124                 .procname       = "tcp_sack",
1125                 .data           = &init_net.ipv4.sysctl_tcp_sack,
1126                 .maxlen         = sizeof(int),
1127                 .mode           = 0644,
1128                 .proc_handler   = proc_dointvec
1129         },
1130         {
1131                 .procname       = "tcp_window_scaling",
1132                 .data           = &init_net.ipv4.sysctl_tcp_window_scaling,
1133                 .maxlen         = sizeof(int),
1134                 .mode           = 0644,
1135                 .proc_handler   = proc_dointvec
1136         },
1137         {
1138                 .procname       = "tcp_timestamps",
1139                 .data           = &init_net.ipv4.sysctl_tcp_timestamps,
1140                 .maxlen         = sizeof(int),
1141                 .mode           = 0644,
1142                 .proc_handler   = proc_dointvec
1143         },
1144         { }
1145 };
1146
1147 static __net_init int ipv4_sysctl_init_net(struct net *net)
1148 {
1149         struct ctl_table *table;
1150
1151         table = ipv4_net_table;
1152         if (!net_eq(net, &init_net)) {
1153                 int i;
1154
1155                 table = kmemdup(table, sizeof(ipv4_net_table), GFP_KERNEL);
1156                 if (!table)
1157                         goto err_alloc;
1158
1159                 /* Update the variables to point into the current struct net */
1160                 for (i = 0; i < ARRAY_SIZE(ipv4_net_table) - 1; i++)
1161                         table[i].data += (void *)net - (void *)&init_net;
1162         }
1163
1164         net->ipv4.ipv4_hdr = register_net_sysctl(net, "net/ipv4", table);
1165         if (!net->ipv4.ipv4_hdr)
1166                 goto err_reg;
1167
1168         net->ipv4.sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1169         if (!net->ipv4.sysctl_local_reserved_ports)
1170                 goto err_ports;
1171
1172         return 0;
1173
1174 err_ports:
1175         unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
1176 err_reg:
1177         if (!net_eq(net, &init_net))
1178                 kfree(table);
1179 err_alloc:
1180         return -ENOMEM;
1181 }
1182
1183 static __net_exit void ipv4_sysctl_exit_net(struct net *net)
1184 {
1185         struct ctl_table *table;
1186
1187         kfree(net->ipv4.sysctl_local_reserved_ports);
1188         table = net->ipv4.ipv4_hdr->ctl_table_arg;
1189         unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
1190         kfree(table);
1191 }
1192
1193 static __net_initdata struct pernet_operations ipv4_sysctl_ops = {
1194         .init = ipv4_sysctl_init_net,
1195         .exit = ipv4_sysctl_exit_net,
1196 };
1197
1198 static __init int sysctl_ipv4_init(void)
1199 {
1200         struct ctl_table_header *hdr;
1201
1202         hdr = register_net_sysctl(&init_net, "net/ipv4", ipv4_table);
1203         if (!hdr)
1204                 return -ENOMEM;
1205
1206         if (register_pernet_subsys(&ipv4_sysctl_ops)) {
1207                 unregister_net_sysctl_table(hdr);
1208                 return -ENOMEM;
1209         }
1210
1211         return 0;
1212 }
1213
1214 __initcall(sysctl_ipv4_init);