net/core/sysctl_net_core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* -*- linux-c -*-
   3  * sysctl_net_core.c: sysctl interface to net core subsystem.
   4  *
   5  * Begun April 1, 1996, Mike Shaver.
   6  * Added /proc/sys/net/core directory entry (empty =) ). [MS]
   7  */
   8
   9 #include <linux/filter.h>
  10 #include <linux/mm.h>
  11 #include <linux/sysctl.h>
  12 #include <linux/module.h>
  13 #include <linux/socket.h>
  14 #include <linux/netdevice.h>
  15 #include <linux/ratelimit.h>
  16 #include <linux/vmalloc.h>
  17 #include <linux/init.h>
  18 #include <linux/slab.h>
  19 #include <linux/sched/isolation.h>
  20
  21 #include <net/ip.h>
  22 #include <net/sock.h>
  23 #include <net/net_ratelimit.h>
  24 #include <net/busy_poll.h>
  25 #include <net/pkt_sched.h>
  26 #include <net/hotdata.h>
  27 #include <net/proto_memory.h>
  28 #include <net/rps.h>
  29
  30 #include "dev.h"
  31
  32 static int int_3600 = 3600;
  33 static int min_sndbuf = SOCK_MIN_SNDBUF;
  34 static int min_rcvbuf = SOCK_MIN_RCVBUF;
  35 static int max_skb_frags = MAX_SKB_FRAGS;
  36 static int min_mem_pcpu_rsv = SK_MEMORY_PCPU_RESERVE;
  37
  38 static int net_msg_warn;        /* Unused, but still a sysctl */
  39
  40 int sysctl_fb_tunnels_only_for_init_net __read_mostly = 0;
  41 EXPORT_SYMBOL(sysctl_fb_tunnels_only_for_init_net);
  42
  43 /* 0 - Keep current behavior:
  44  *     IPv4: inherit all current settings from init_net
  45  *     IPv6: reset all settings to default
  46  * 1 - Both inherit all current settings from init_net
  47  * 2 - Both reset all settings to default
  48  * 3 - Both inherit all settings from current netns
  49  */
  50 int sysctl_devconf_inherit_init_net __read_mostly;
  51 EXPORT_SYMBOL(sysctl_devconf_inherit_init_net);
  52
  53 #if IS_ENABLED(CONFIG_NET_FLOW_LIMIT) || IS_ENABLED(CONFIG_RPS)
  54 static void dump_cpumask(void *buffer, size_t *lenp, loff_t *ppos,
  55                          struct cpumask *mask)
  56 {
  57         char kbuf[128];
  58         int len;
  59
  60         if (*ppos || !*lenp) {
  61                 *lenp = 0;
  62                 return;
  63         }
  64
  65         len = min(sizeof(kbuf) - 1, *lenp);
  66         len = scnprintf(kbuf, len, "%*pb", cpumask_pr_args(mask));
  67         if (!len) {
  68                 *lenp = 0;
  69                 return;
  70         }
  71
  72         if (len < *lenp)
  73                 kbuf[len++] = '\n';
  74         memcpy(buffer, kbuf, len);
  75         *lenp = len;
  76         *ppos += len;
  77 }
  78 #endif
  79
  80 #ifdef CONFIG_RPS
  81
  82 static struct cpumask *rps_default_mask_cow_alloc(struct net *net)
  83 {
  84         struct cpumask *rps_default_mask;
  85
  86         if (net->core.rps_default_mask)
  87                 return net->core.rps_default_mask;
  88
  89         rps_default_mask = kzalloc(cpumask_size(), GFP_KERNEL);
  90         if (!rps_default_mask)
  91                 return NULL;
  92
  93         /* pairs with READ_ONCE in rx_queue_default_mask() */
  94         WRITE_ONCE(net->core.rps_default_mask, rps_default_mask);
  95         return rps_default_mask;
  96 }
  97
  98 static int rps_default_mask_sysctl(const struct ctl_table *table, int write,
  99                                    void *buffer, size_t *lenp, loff_t *ppos)
 100 {
 101         struct net *net = (struct net *)table->data;
 102         int err = 0;
 103
 104         rtnl_lock();
 105         if (write) {
 106                 struct cpumask *rps_default_mask = rps_default_mask_cow_alloc(net);
 107
 108                 err = -ENOMEM;
 109                 if (!rps_default_mask)
 110                         goto done;
 111
 112                 err = cpumask_parse(buffer, rps_default_mask);
 113                 if (err)
 114                         goto done;
 115
 116                 err = rps_cpumask_housekeeping(rps_default_mask);
 117                 if (err)
 118                         goto done;
 119         } else {
 120                 dump_cpumask(buffer, lenp, ppos,
 121                              net->core.rps_default_mask ? : cpu_none_mask);
 122         }
 123
 124 done:
 125         rtnl_unlock();
 126         return err;
 127 }
 128
 129 static int rps_sock_flow_sysctl(const struct ctl_table *table, int write,
 130                                 void *buffer, size_t *lenp, loff_t *ppos)
 131 {
 132         unsigned int orig_size, size;
 133         int ret, i;
 134         struct ctl_table tmp = {
 135                 .data = &size,
 136                 .maxlen = sizeof(size),
 137                 .mode = table->mode
 138         };
 139         struct rps_sock_flow_table *orig_sock_table, *sock_table;
 140         static DEFINE_MUTEX(sock_flow_mutex);
 141
 142         mutex_lock(&sock_flow_mutex);
 143
 144         orig_sock_table = rcu_dereference_protected(
 145                                         net_hotdata.rps_sock_flow_table,
 146                                         lockdep_is_held(&sock_flow_mutex));
 147         size = orig_size = orig_sock_table ? orig_sock_table->mask + 1 : 0;
 148
 149         ret = proc_dointvec(&tmp, write, buffer, lenp, ppos);
 150
 151         if (write) {
 152                 if (size) {
 153                         if (size > 1<<29) {
 154                                 /* Enforce limit to prevent overflow */
 155                                 mutex_unlock(&sock_flow_mutex);
 156                                 return -EINVAL;
 157                         }
 158                         size = roundup_pow_of_two(size);
 159                         if (size != orig_size) {
 160                                 sock_table =
 161                                     vmalloc(RPS_SOCK_FLOW_TABLE_SIZE(size));
 162                                 if (!sock_table) {
 163                                         mutex_unlock(&sock_flow_mutex);
 164                                         return -ENOMEM;
 165                                 }
 166                                 net_hotdata.rps_cpu_mask =
 167                                         roundup_pow_of_two(nr_cpu_ids) - 1;
 168                                 sock_table->mask = size - 1;
 169                         } else
 170                                 sock_table = orig_sock_table;
 171
 172                         for (i = 0; i < size; i++)
 173                                 sock_table->ents[i] = RPS_NO_CPU;
 174                 } else
 175                         sock_table = NULL;
 176
 177                 if (sock_table != orig_sock_table) {
 178                         rcu_assign_pointer(net_hotdata.rps_sock_flow_table,
 179                                            sock_table);
 180                         if (sock_table) {
 181                                 static_branch_inc(&rps_needed);
 182                                 static_branch_inc(&rfs_needed);
 183                         }
 184                         if (orig_sock_table) {
 185                                 static_branch_dec(&rps_needed);
 186                                 static_branch_dec(&rfs_needed);
 187                                 kvfree_rcu_mightsleep(orig_sock_table);
 188                         }
 189                 }
 190         }
 191
 192         mutex_unlock(&sock_flow_mutex);
 193
 194         return ret;
 195 }
 196 #endif /* CONFIG_RPS */
 197
 198 #ifdef CONFIG_NET_FLOW_LIMIT
 199 static DEFINE_MUTEX(flow_limit_update_mutex);
 200
 201 static int flow_limit_cpu_sysctl(const struct ctl_table *table, int write,
 202                                  void *buffer, size_t *lenp, loff_t *ppos)
 203 {
 204         struct sd_flow_limit *cur;
 205         struct softnet_data *sd;
 206         cpumask_var_t mask;
 207         int i, len, ret = 0;
 208
 209         if (!alloc_cpumask_var(&mask, GFP_KERNEL))
 210                 return -ENOMEM;
 211
 212         if (write) {
 213                 ret = cpumask_parse(buffer, mask);
 214                 if (ret)
 215                         goto done;
 216
 217                 mutex_lock(&flow_limit_update_mutex);
 218                 len = sizeof(*cur) + netdev_flow_limit_table_len;
 219                 for_each_possible_cpu(i) {
 220                         sd = &per_cpu(softnet_data, i);
 221                         cur = rcu_dereference_protected(sd->flow_limit,
 222                                      lockdep_is_held(&flow_limit_update_mutex));
 223                         if (cur && !cpumask_test_cpu(i, mask)) {
 224                                 RCU_INIT_POINTER(sd->flow_limit, NULL);
 225                                 kfree_rcu_mightsleep(cur);
 226                         } else if (!cur && cpumask_test_cpu(i, mask)) {
 227                                 cur = kzalloc_node(len, GFP_KERNEL,
 228                                                    cpu_to_node(i));
 229                                 if (!cur) {
 230                                         /* not unwinding previous changes */
 231                                         ret = -ENOMEM;
 232                                         goto write_unlock;
 233                                 }
 234                                 cur->num_buckets = netdev_flow_limit_table_len;
 235                                 rcu_assign_pointer(sd->flow_limit, cur);
 236                         }
 237                 }
 238 write_unlock:
 239                 mutex_unlock(&flow_limit_update_mutex);
 240         } else {
 241                 cpumask_clear(mask);
 242                 rcu_read_lock();
 243                 for_each_possible_cpu(i) {
 244                         sd = &per_cpu(softnet_data, i);
 245                         if (rcu_dereference(sd->flow_limit))
 246                                 cpumask_set_cpu(i, mask);
 247                 }
 248                 rcu_read_unlock();
 249
 250                 dump_cpumask(buffer, lenp, ppos, mask);
 251         }
 252
 253 done:
 254         free_cpumask_var(mask);
 255         return ret;
 256 }
 257
 258 static int flow_limit_table_len_sysctl(const struct ctl_table *table, int write,
 259                                        void *buffer, size_t *lenp, loff_t *ppos)
 260 {
 261         unsigned int old, *ptr;
 262         int ret;
 263
 264         mutex_lock(&flow_limit_update_mutex);
 265
 266         ptr = table->data;
 267         old = *ptr;
 268         ret = proc_dointvec(table, write, buffer, lenp, ppos);
 269         if (!ret && write && !is_power_of_2(*ptr)) {
 270                 *ptr = old;
 271                 ret = -EINVAL;
 272         }
 273
 274         mutex_unlock(&flow_limit_update_mutex);
 275         return ret;
 276 }
 277 #endif /* CONFIG_NET_FLOW_LIMIT */
 278
 279 #ifdef CONFIG_NET_SCHED
 280 static int set_default_qdisc(const struct ctl_table *table, int write,
 281                              void *buffer, size_t *lenp, loff_t *ppos)
 282 {
 283         char id[IFNAMSIZ];
 284         struct ctl_table tbl = {
 285                 .data = id,
 286                 .maxlen = IFNAMSIZ,
 287         };
 288         int ret;
 289
 290         qdisc_get_default(id, IFNAMSIZ);
 291
 292         ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
 293         if (write && ret == 0)
 294                 ret = qdisc_set_default(id);
 295         return ret;
 296 }
 297 #endif
 298
 299 static int proc_do_dev_weight(const struct ctl_table *table, int write,
 300                            void *buffer, size_t *lenp, loff_t *ppos)
 301 {
 302         static DEFINE_MUTEX(dev_weight_mutex);
 303         int ret, weight;
 304
 305         mutex_lock(&dev_weight_mutex);
 306         ret = proc_dointvec(table, write, buffer, lenp, ppos);
 307         if (!ret && write) {
 308                 weight = READ_ONCE(weight_p);
 309                 WRITE_ONCE(net_hotdata.dev_rx_weight, weight * dev_weight_rx_bias);
 310                 WRITE_ONCE(net_hotdata.dev_tx_weight, weight * dev_weight_tx_bias);
 311         }
 312         mutex_unlock(&dev_weight_mutex);
 313
 314         return ret;
 315 }
 316
 317 static int proc_do_rss_key(const struct ctl_table *table, int write,
 318                            void *buffer, size_t *lenp, loff_t *ppos)
 319 {
 320         struct ctl_table fake_table;
 321         char buf[NETDEV_RSS_KEY_LEN * 3];
 322
 323         snprintf(buf, sizeof(buf), "%*phC", NETDEV_RSS_KEY_LEN, netdev_rss_key);
 324         fake_table.data = buf;
 325         fake_table.maxlen = sizeof(buf);
 326         return proc_dostring(&fake_table, write, buffer, lenp, ppos);
 327 }
 328
 329 #ifdef CONFIG_BPF_JIT
 330 static int proc_dointvec_minmax_bpf_enable(const struct ctl_table *table, int write,
 331                                            void *buffer, size_t *lenp,
 332                                            loff_t *ppos)
 333 {
 334         int ret, jit_enable = *(int *)table->data;
 335         int min = *(int *)table->extra1;
 336         int max = *(int *)table->extra2;
 337         struct ctl_table tmp = *table;
 338
 339         if (write && !capable(CAP_SYS_ADMIN))
 340                 return -EPERM;
 341
 342         tmp.data = &jit_enable;
 343         ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
 344         if (write && !ret) {
 345                 if (jit_enable < 2 ||
 346                     (jit_enable == 2 && bpf_dump_raw_ok(current_cred()))) {
 347                         *(int *)table->data = jit_enable;
 348                         if (jit_enable == 2)
 349                                 pr_warn("bpf_jit_enable = 2 was set! NEVER use this in production, only for JIT debugging!\n");
 350                 } else {
 351                         ret = -EPERM;
 352                 }
 353         }
 354
 355         if (write && ret && min == max)
 356                 pr_info_once("CONFIG_BPF_JIT_ALWAYS_ON is enabled, bpf_jit_enable is permanently set to 1.\n");
 357
 358         return ret;
 359 }
 360
 361 # ifdef CONFIG_HAVE_EBPF_JIT
 362 static int
 363 proc_dointvec_minmax_bpf_restricted(const struct ctl_table *table, int write,
 364                                     void *buffer, size_t *lenp, loff_t *ppos)
 365 {
 366         if (!capable(CAP_SYS_ADMIN))
 367                 return -EPERM;
 368
 369         return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 370 }
 371 # endif /* CONFIG_HAVE_EBPF_JIT */
 372
 373 static int
 374 proc_dolongvec_minmax_bpf_restricted(const struct ctl_table *table, int write,
 375                                      void *buffer, size_t *lenp, loff_t *ppos)
 376 {
 377         if (!capable(CAP_SYS_ADMIN))
 378                 return -EPERM;
 379
 380         return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
 381 }
 382 #endif
 383
 384 static struct ctl_table net_core_table[] = {
 385         {
 386                 .procname       = "mem_pcpu_rsv",
 387                 .data           = &net_hotdata.sysctl_mem_pcpu_rsv,
 388                 .maxlen         = sizeof(int),
 389                 .mode           = 0644,
 390                 .proc_handler   = proc_dointvec_minmax,
 391                 .extra1         = &min_mem_pcpu_rsv,
 392         },
 393         {
 394                 .procname       = "dev_weight",
 395                 .data           = &weight_p,
 396                 .maxlen         = sizeof(int),
 397                 .mode           = 0644,
 398                 .proc_handler   = proc_do_dev_weight,
 399         },
 400         {
 401                 .procname       = "dev_weight_rx_bias",
 402                 .data           = &dev_weight_rx_bias,
 403                 .maxlen         = sizeof(int),
 404                 .mode           = 0644,
 405                 .proc_handler   = proc_do_dev_weight,
 406         },
 407         {
 408                 .procname       = "dev_weight_tx_bias",
 409                 .data           = &dev_weight_tx_bias,
 410                 .maxlen         = sizeof(int),
 411                 .mode           = 0644,
 412                 .proc_handler   = proc_do_dev_weight,
 413         },
 414         {
 415                 .procname       = "netdev_max_backlog",
 416                 .data           = &net_hotdata.max_backlog,
 417                 .maxlen         = sizeof(int),
 418                 .mode           = 0644,
 419                 .proc_handler   = proc_dointvec
 420         },
 421         {
 422                 .procname       = "netdev_rss_key",
 423                 .data           = &netdev_rss_key,
 424                 .maxlen         = sizeof(int),
 425                 .mode           = 0444,
 426                 .proc_handler   = proc_do_rss_key,
 427         },
 428 #ifdef CONFIG_BPF_JIT
 429         {
 430                 .procname       = "bpf_jit_enable",
 431                 .data           = &bpf_jit_enable,
 432                 .maxlen         = sizeof(int),
 433                 .mode           = 0644,
 434                 .proc_handler   = proc_dointvec_minmax_bpf_enable,
 435 # ifdef CONFIG_BPF_JIT_ALWAYS_ON
 436                 .extra1         = SYSCTL_ONE,
 437                 .extra2         = SYSCTL_ONE,
 438 # else
 439                 .extra1         = SYSCTL_ZERO,
 440                 .extra2         = SYSCTL_TWO,
 441 # endif
 442         },
 443 # ifdef CONFIG_HAVE_EBPF_JIT
 444         {
 445                 .procname       = "bpf_jit_harden",
 446                 .data           = &bpf_jit_harden,
 447                 .maxlen         = sizeof(int),
 448                 .mode           = 0600,
 449                 .proc_handler   = proc_dointvec_minmax_bpf_restricted,
 450                 .extra1         = SYSCTL_ZERO,
 451                 .extra2         = SYSCTL_TWO,
 452         },
 453         {
 454                 .procname       = "bpf_jit_kallsyms",
 455                 .data           = &bpf_jit_kallsyms,
 456                 .maxlen         = sizeof(int),
 457                 .mode           = 0600,
 458                 .proc_handler   = proc_dointvec_minmax_bpf_restricted,
 459                 .extra1         = SYSCTL_ZERO,
 460                 .extra2         = SYSCTL_ONE,
 461         },
 462 # endif
 463         {
 464                 .procname       = "bpf_jit_limit",
 465                 .data           = &bpf_jit_limit,
 466                 .maxlen         = sizeof(long),
 467                 .mode           = 0600,
 468                 .proc_handler   = proc_dolongvec_minmax_bpf_restricted,
 469                 .extra1         = SYSCTL_LONG_ONE,
 470                 .extra2         = &bpf_jit_limit_max,
 471         },
 472 #endif
 473         {
 474                 .procname       = "netdev_tstamp_prequeue",
 475                 .data           = &net_hotdata.tstamp_prequeue,
 476                 .maxlen         = sizeof(int),
 477                 .mode           = 0644,
 478                 .proc_handler   = proc_dointvec
 479         },
 480         {
 481                 .procname       = "message_cost",
 482                 .data           = &net_ratelimit_state.interval,
 483                 .maxlen         = sizeof(int),
 484                 .mode           = 0644,
 485                 .proc_handler   = proc_dointvec_jiffies,
 486         },
 487         {
 488                 .procname       = "message_burst",
 489                 .data           = &net_ratelimit_state.burst,
 490                 .maxlen         = sizeof(int),
 491                 .mode           = 0644,
 492                 .proc_handler   = proc_dointvec,
 493         },
 494         {
 495                 .procname       = "tstamp_allow_data",
 496                 .data           = &sysctl_tstamp_allow_data,
 497                 .maxlen         = sizeof(int),
 498                 .mode           = 0644,
 499                 .proc_handler   = proc_dointvec_minmax,
 500                 .extra1         = SYSCTL_ZERO,
 501                 .extra2         = SYSCTL_ONE
 502         },
 503 #ifdef CONFIG_RPS
 504         {
 505                 .procname       = "rps_sock_flow_entries",
 506                 .maxlen         = sizeof(int),
 507                 .mode           = 0644,
 508                 .proc_handler   = rps_sock_flow_sysctl
 509         },
 510 #endif
 511 #ifdef CONFIG_NET_FLOW_LIMIT
 512         {
 513                 .procname       = "flow_limit_cpu_bitmap",
 514                 .mode           = 0644,
 515                 .proc_handler   = flow_limit_cpu_sysctl
 516         },
 517         {
 518                 .procname       = "flow_limit_table_len",
 519                 .data           = &netdev_flow_limit_table_len,
 520                 .maxlen         = sizeof(int),
 521                 .mode           = 0644,
 522                 .proc_handler   = flow_limit_table_len_sysctl
 523         },
 524 #endif /* CONFIG_NET_FLOW_LIMIT */
 525 #ifdef CONFIG_NET_RX_BUSY_POLL
 526         {
 527                 .procname       = "busy_poll",
 528                 .data           = &sysctl_net_busy_poll,
 529                 .maxlen         = sizeof(unsigned int),
 530                 .mode           = 0644,
 531                 .proc_handler   = proc_dointvec_minmax,
 532                 .extra1         = SYSCTL_ZERO,
 533         },
 534         {
 535                 .procname       = "busy_read",
 536                 .data           = &sysctl_net_busy_read,
 537                 .maxlen         = sizeof(unsigned int),
 538                 .mode           = 0644,
 539                 .proc_handler   = proc_dointvec_minmax,
 540                 .extra1         = SYSCTL_ZERO,
 541         },
 542 #endif
 543 #ifdef CONFIG_NET_SCHED
 544         {
 545                 .procname       = "default_qdisc",
 546                 .mode           = 0644,
 547                 .maxlen         = IFNAMSIZ,
 548                 .proc_handler   = set_default_qdisc
 549         },
 550 #endif
 551         {
 552                 .procname       = "netdev_budget",
 553                 .data           = &net_hotdata.netdev_budget,
 554                 .maxlen         = sizeof(int),
 555                 .mode           = 0644,
 556                 .proc_handler   = proc_dointvec
 557         },
 558         {
 559                 .procname       = "warnings",
 560                 .data           = &net_msg_warn,
 561                 .maxlen         = sizeof(int),
 562                 .mode           = 0644,
 563                 .proc_handler   = proc_dointvec
 564         },
 565         {
 566                 .procname       = "max_skb_frags",
 567                 .data           = &net_hotdata.sysctl_max_skb_frags,
 568                 .maxlen         = sizeof(int),
 569                 .mode           = 0644,
 570                 .proc_handler   = proc_dointvec_minmax,
 571                 .extra1         = SYSCTL_ONE,
 572                 .extra2         = &max_skb_frags,
 573         },
 574         {
 575                 .procname       = "netdev_budget_usecs",
 576                 .data           = &net_hotdata.netdev_budget_usecs,
 577                 .maxlen         = sizeof(unsigned int),
 578                 .mode           = 0644,
 579                 .proc_handler   = proc_dointvec_minmax,
 580                 .extra1         = SYSCTL_ZERO,
 581         },
 582         {
 583                 .procname       = "fb_tunnels_only_for_init_net",
 584                 .data           = &sysctl_fb_tunnels_only_for_init_net,
 585                 .maxlen         = sizeof(int),
 586                 .mode           = 0644,
 587                 .proc_handler   = proc_dointvec_minmax,
 588                 .extra1         = SYSCTL_ZERO,
 589                 .extra2         = SYSCTL_TWO,
 590         },
 591         {
 592                 .procname       = "devconf_inherit_init_net",
 593                 .data           = &sysctl_devconf_inherit_init_net,
 594                 .maxlen         = sizeof(int),
 595                 .mode           = 0644,
 596                 .proc_handler   = proc_dointvec_minmax,
 597                 .extra1         = SYSCTL_ZERO,
 598                 .extra2         = SYSCTL_THREE,
 599         },
 600         {
 601                 .procname       = "high_order_alloc_disable",
 602                 .data           = &net_high_order_alloc_disable_key.key,
 603                 .maxlen         = sizeof(net_high_order_alloc_disable_key),
 604                 .mode           = 0644,
 605                 .proc_handler   = proc_do_static_key,
 606         },
 607         {
 608                 .procname       = "gro_normal_batch",
 609                 .data           = &net_hotdata.gro_normal_batch,
 610                 .maxlen         = sizeof(unsigned int),
 611                 .mode           = 0644,
 612                 .proc_handler   = proc_dointvec_minmax,
 613                 .extra1         = SYSCTL_ONE,
 614         },
 615         {
 616                 .procname       = "netdev_unregister_timeout_secs",
 617                 .data           = &netdev_unregister_timeout_secs,
 618                 .maxlen         = sizeof(unsigned int),
 619                 .mode           = 0644,
 620                 .proc_handler   = proc_dointvec_minmax,
 621                 .extra1         = SYSCTL_ONE,
 622                 .extra2         = &int_3600,
 623         },
 624         {
 625                 .procname       = "skb_defer_max",
 626                 .data           = &net_hotdata.sysctl_skb_defer_max,
 627                 .maxlen         = sizeof(unsigned int),
 628                 .mode           = 0644,
 629                 .proc_handler   = proc_dointvec_minmax,
 630                 .extra1         = SYSCTL_ZERO,
 631         },
 632 };
 633
 634 static struct ctl_table netns_core_table[] = {
 635 #if IS_ENABLED(CONFIG_RPS)
 636         {
 637                 .procname       = "rps_default_mask",
 638                 .data           = &init_net,
 639                 .mode           = 0644,
 640                 .proc_handler   = rps_default_mask_sysctl
 641         },
 642 #endif
 643         {
 644                 .procname       = "somaxconn",
 645                 .data           = &init_net.core.sysctl_somaxconn,
 646                 .maxlen         = sizeof(int),
 647                 .mode           = 0644,
 648                 .extra1         = SYSCTL_ZERO,
 649                 .proc_handler   = proc_dointvec_minmax
 650         },
 651         {
 652                 .procname       = "optmem_max",
 653                 .data           = &init_net.core.sysctl_optmem_max,
 654                 .maxlen         = sizeof(int),
 655                 .mode           = 0644,
 656                 .extra1         = SYSCTL_ZERO,
 657                 .proc_handler   = proc_dointvec_minmax
 658         },
 659         {
 660                 .procname       = "txrehash",
 661                 .data           = &init_net.core.sysctl_txrehash,
 662                 .maxlen         = sizeof(u8),
 663                 .mode           = 0644,
 664                 .extra1         = SYSCTL_ZERO,
 665                 .extra2         = SYSCTL_ONE,
 666                 .proc_handler   = proc_dou8vec_minmax,
 667         },
 668         /* sysctl_core_net_init() will set the values after this
 669          * to readonly in network namespaces
 670          */
 671         {
 672                 .procname       = "wmem_max",
 673                 .data           = &sysctl_wmem_max,
 674                 .maxlen         = sizeof(int),
 675                 .mode           = 0644,
 676                 .proc_handler   = proc_dointvec_minmax,
 677                 .extra1         = &min_sndbuf,
 678         },
 679         {
 680                 .procname       = "rmem_max",
 681                 .data           = &sysctl_rmem_max,
 682                 .maxlen         = sizeof(int),
 683                 .mode           = 0644,
 684                 .proc_handler   = proc_dointvec_minmax,
 685                 .extra1         = &min_rcvbuf,
 686         },
 687         {
 688                 .procname       = "wmem_default",
 689                 .data           = &sysctl_wmem_default,
 690                 .maxlen         = sizeof(int),
 691                 .mode           = 0644,
 692                 .proc_handler   = proc_dointvec_minmax,
 693                 .extra1         = &min_sndbuf,
 694         },
 695         {
 696                 .procname       = "rmem_default",
 697                 .data           = &sysctl_rmem_default,
 698                 .maxlen         = sizeof(int),
 699                 .mode           = 0644,
 700                 .proc_handler   = proc_dointvec_minmax,
 701                 .extra1         = &min_rcvbuf,
 702         },
 703 };
 704
 705 static int __init fb_tunnels_only_for_init_net_sysctl_setup(char *str)
 706 {
 707         /* fallback tunnels for initns only */
 708         if (!strncmp(str, "initns", 6))
 709                 sysctl_fb_tunnels_only_for_init_net = 1;
 710         /* no fallback tunnels anywhere */
 711         else if (!strncmp(str, "none", 4))
 712                 sysctl_fb_tunnels_only_for_init_net = 2;
 713
 714         return 1;
 715 }
 716 __setup("fb_tunnels=", fb_tunnels_only_for_init_net_sysctl_setup);
 717
 718 static __net_init int sysctl_core_net_init(struct net *net)
 719 {
 720         size_t table_size = ARRAY_SIZE(netns_core_table);
 721         struct ctl_table *tbl;
 722
 723         tbl = netns_core_table;
 724         if (!net_eq(net, &init_net)) {
 725                 int i;
 726                 tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL);
 727                 if (tbl == NULL)
 728                         goto err_dup;
 729
 730                 for (i = 0; i < table_size; ++i) {
 731                         if (tbl[i].data == &sysctl_wmem_max)
 732                                 break;
 733
 734                         tbl[i].data += (char *)net - (char *)&init_net;
 735                 }
 736                 for (; i < table_size; ++i)
 737                         tbl[i].mode &= ~0222;
 738         }
 739
 740         net->core.sysctl_hdr = register_net_sysctl_sz(net, "net/core", tbl, table_size);
 741         if (net->core.sysctl_hdr == NULL)
 742                 goto err_reg;
 743
 744         return 0;
 745
 746 err_reg:
 747         if (tbl != netns_core_table)
 748                 kfree(tbl);
 749 err_dup:
 750         return -ENOMEM;
 751 }
 752
 753 static __net_exit void sysctl_core_net_exit(struct net *net)
 754 {
 755         const struct ctl_table *tbl;
 756
 757         tbl = net->core.sysctl_hdr->ctl_table_arg;
 758         unregister_net_sysctl_table(net->core.sysctl_hdr);
 759         BUG_ON(tbl == netns_core_table);
 760 #if IS_ENABLED(CONFIG_RPS)
 761         kfree(net->core.rps_default_mask);
 762 #endif
 763         kfree(tbl);
 764 }
 765
 766 static __net_initdata struct pernet_operations sysctl_core_ops = {
 767         .init = sysctl_core_net_init,
 768         .exit = sysctl_core_net_exit,
 769 };
 770
 771 static __init int sysctl_core_init(void)
 772 {
 773         register_net_sysctl(&init_net, "net/core", net_core_table);
 774         return register_pernet_subsys(&sysctl_core_ops);
 775 }
 776
 777 fs_initcall(sysctl_core_init);