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/mm.h> 10 #include <linux/sysctl.h> 11 #include <linux/module.h> 12 #include <linux/socket.h> 13 #include <linux/netdevice.h> 14 #include <linux/ratelimit.h> 15 #include <linux/vmalloc.h> 16 #include <linux/init.h> 17 #include <linux/slab.h> 18 19 #include <net/ip.h> 20 #include <net/sock.h> 21 #include <net/net_ratelimit.h> 22 #include <net/busy_poll.h> 23 #include <net/pkt_sched.h> 24 25 static int two __maybe_unused = 2; 26 static int min_sndbuf = SOCK_MIN_SNDBUF; 27 static int min_rcvbuf = SOCK_MIN_RCVBUF; 28 static int max_skb_frags = MAX_SKB_FRAGS; 29 static long long_one __maybe_unused = 1; 30 static long long_max __maybe_unused = LONG_MAX; 31 32 static int net_msg_warn; /* Unused, but still a sysctl */ 33 34 int sysctl_fb_tunnels_only_for_init_net __read_mostly = 0; 35 EXPORT_SYMBOL(sysctl_fb_tunnels_only_for_init_net); 36 37 /* 0 - Keep current behavior: 38 * IPv4: inherit all current settings from init_net 39 * IPv6: reset all settings to default 40 * 1 - Both inherit all current settings from init_net 41 * 2 - Both reset all settings to default 42 */ 43 int sysctl_devconf_inherit_init_net __read_mostly; 44 EXPORT_SYMBOL(sysctl_devconf_inherit_init_net); 45 46 #ifdef CONFIG_RPS 47 static int rps_sock_flow_sysctl(struct ctl_table *table, int write, 48 void *buffer, size_t *lenp, loff_t *ppos) 49 { 50 unsigned int orig_size, size; 51 int ret, i; 52 struct ctl_table tmp = { 53 .data = &size, 54 .maxlen = sizeof(size), 55 .mode = table->mode 56 }; 57 struct rps_sock_flow_table *orig_sock_table, *sock_table; 58 static DEFINE_MUTEX(sock_flow_mutex); 59 60 mutex_lock(&sock_flow_mutex); 61 62 orig_sock_table = rcu_dereference_protected(rps_sock_flow_table, 63 lockdep_is_held(&sock_flow_mutex)); 64 size = orig_size = orig_sock_table ? orig_sock_table->mask + 1 : 0; 65 66 ret = proc_dointvec(&tmp, write, buffer, lenp, ppos); 67 68 if (write) { 69 if (size) { 70 if (size > 1<<29) { 71 /* Enforce limit to prevent overflow */ 72 mutex_unlock(&sock_flow_mutex); 73 return -EINVAL; 74 } 75 size = roundup_pow_of_two(size); 76 if (size != orig_size) { 77 sock_table = 78 vmalloc(RPS_SOCK_FLOW_TABLE_SIZE(size)); 79 if (!sock_table) { 80 mutex_unlock(&sock_flow_mutex); 81 return -ENOMEM; 82 } 83 rps_cpu_mask = roundup_pow_of_two(nr_cpu_ids) - 1; 84 sock_table->mask = size - 1; 85 } else 86 sock_table = orig_sock_table; 87 88 for (i = 0; i < size; i++) 89 sock_table->ents[i] = RPS_NO_CPU; 90 } else 91 sock_table = NULL; 92 93 if (sock_table != orig_sock_table) { 94 rcu_assign_pointer(rps_sock_flow_table, sock_table); 95 if (sock_table) { 96 static_branch_inc(&rps_needed); 97 static_branch_inc(&rfs_needed); 98 } 99 if (orig_sock_table) { 100 static_branch_dec(&rps_needed); 101 static_branch_dec(&rfs_needed); 102 synchronize_rcu(); 103 vfree(orig_sock_table); 104 } 105 } 106 } 107 108 mutex_unlock(&sock_flow_mutex); 109 110 return ret; 111 } 112 #endif /* CONFIG_RPS */ 113 114 #ifdef CONFIG_NET_FLOW_LIMIT 115 static DEFINE_MUTEX(flow_limit_update_mutex); 116 117 static int flow_limit_cpu_sysctl(struct ctl_table *table, int write, 118 void *buffer, size_t *lenp, loff_t *ppos) 119 { 120 struct sd_flow_limit *cur; 121 struct softnet_data *sd; 122 cpumask_var_t mask; 123 int i, len, ret = 0; 124 125 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) 126 return -ENOMEM; 127 128 if (write) { 129 ret = cpumask_parse_user(buffer, *lenp, mask); 130 if (ret) 131 goto done; 132 133 mutex_lock(&flow_limit_update_mutex); 134 len = sizeof(*cur) + netdev_flow_limit_table_len; 135 for_each_possible_cpu(i) { 136 sd = &per_cpu(softnet_data, i); 137 cur = rcu_dereference_protected(sd->flow_limit, 138 lockdep_is_held(&flow_limit_update_mutex)); 139 if (cur && !cpumask_test_cpu(i, mask)) { 140 RCU_INIT_POINTER(sd->flow_limit, NULL); 141 synchronize_rcu(); 142 kfree(cur); 143 } else if (!cur && cpumask_test_cpu(i, mask)) { 144 cur = kzalloc_node(len, GFP_KERNEL, 145 cpu_to_node(i)); 146 if (!cur) { 147 /* not unwinding previous changes */ 148 ret = -ENOMEM; 149 goto write_unlock; 150 } 151 cur->num_buckets = netdev_flow_limit_table_len; 152 rcu_assign_pointer(sd->flow_limit, cur); 153 } 154 } 155 write_unlock: 156 mutex_unlock(&flow_limit_update_mutex); 157 } else { 158 char kbuf[128]; 159 160 if (*ppos || !*lenp) { 161 *lenp = 0; 162 goto done; 163 } 164 165 cpumask_clear(mask); 166 rcu_read_lock(); 167 for_each_possible_cpu(i) { 168 sd = &per_cpu(softnet_data, i); 169 if (rcu_dereference(sd->flow_limit)) 170 cpumask_set_cpu(i, mask); 171 } 172 rcu_read_unlock(); 173 174 len = min(sizeof(kbuf) - 1, *lenp); 175 len = scnprintf(kbuf, len, "%*pb", cpumask_pr_args(mask)); 176 if (!len) { 177 *lenp = 0; 178 goto done; 179 } 180 if (len < *lenp) 181 kbuf[len++] = '\n'; 182 memcpy(buffer, kbuf, len); 183 *lenp = len; 184 *ppos += len; 185 } 186 187 done: 188 free_cpumask_var(mask); 189 return ret; 190 } 191 192 static int flow_limit_table_len_sysctl(struct ctl_table *table, int write, 193 void *buffer, size_t *lenp, loff_t *ppos) 194 { 195 unsigned int old, *ptr; 196 int ret; 197 198 mutex_lock(&flow_limit_update_mutex); 199 200 ptr = table->data; 201 old = *ptr; 202 ret = proc_dointvec(table, write, buffer, lenp, ppos); 203 if (!ret && write && !is_power_of_2(*ptr)) { 204 *ptr = old; 205 ret = -EINVAL; 206 } 207 208 mutex_unlock(&flow_limit_update_mutex); 209 return ret; 210 } 211 #endif /* CONFIG_NET_FLOW_LIMIT */ 212 213 #ifdef CONFIG_NET_SCHED 214 static int set_default_qdisc(struct ctl_table *table, int write, 215 void *buffer, size_t *lenp, loff_t *ppos) 216 { 217 char id[IFNAMSIZ]; 218 struct ctl_table tbl = { 219 .data = id, 220 .maxlen = IFNAMSIZ, 221 }; 222 int ret; 223 224 qdisc_get_default(id, IFNAMSIZ); 225 226 ret = proc_dostring(&tbl, write, buffer, lenp, ppos); 227 if (write && ret == 0) 228 ret = qdisc_set_default(id); 229 return ret; 230 } 231 #endif 232 233 static int proc_do_dev_weight(struct ctl_table *table, int write, 234 void *buffer, size_t *lenp, loff_t *ppos) 235 { 236 int ret; 237 238 ret = proc_dointvec(table, write, buffer, lenp, ppos); 239 if (ret != 0) 240 return ret; 241 242 dev_rx_weight = weight_p * dev_weight_rx_bias; 243 dev_tx_weight = weight_p * dev_weight_tx_bias; 244 245 return ret; 246 } 247 248 static int proc_do_rss_key(struct ctl_table *table, int write, 249 void *buffer, size_t *lenp, loff_t *ppos) 250 { 251 struct ctl_table fake_table; 252 char buf[NETDEV_RSS_KEY_LEN * 3]; 253 254 snprintf(buf, sizeof(buf), "%*phC", NETDEV_RSS_KEY_LEN, netdev_rss_key); 255 fake_table.data = buf; 256 fake_table.maxlen = sizeof(buf); 257 return proc_dostring(&fake_table, write, buffer, lenp, ppos); 258 } 259 260 #ifdef CONFIG_BPF_JIT 261 static int proc_dointvec_minmax_bpf_enable(struct ctl_table *table, int write, 262 void *buffer, size_t *lenp, 263 loff_t *ppos) 264 { 265 int ret, jit_enable = *(int *)table->data; 266 struct ctl_table tmp = *table; 267 268 if (write && !capable(CAP_SYS_ADMIN)) 269 return -EPERM; 270 271 tmp.data = &jit_enable; 272 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 273 if (write && !ret) { 274 if (jit_enable < 2 || 275 (jit_enable == 2 && bpf_dump_raw_ok())) { 276 *(int *)table->data = jit_enable; 277 if (jit_enable == 2) 278 pr_warn("bpf_jit_enable = 2 was set! NEVER use this in production, only for JIT debugging!\n"); 279 } else { 280 ret = -EPERM; 281 } 282 } 283 return ret; 284 } 285 286 # ifdef CONFIG_HAVE_EBPF_JIT 287 static int 288 proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write, 289 void *buffer, size_t *lenp, loff_t *ppos) 290 { 291 if (!capable(CAP_SYS_ADMIN)) 292 return -EPERM; 293 294 return proc_dointvec_minmax(table, write, buffer, lenp, ppos); 295 } 296 # endif /* CONFIG_HAVE_EBPF_JIT */ 297 298 static int 299 proc_dolongvec_minmax_bpf_restricted(struct ctl_table *table, int write, 300 void *buffer, size_t *lenp, loff_t *ppos) 301 { 302 if (!capable(CAP_SYS_ADMIN)) 303 return -EPERM; 304 305 return proc_doulongvec_minmax(table, write, buffer, lenp, ppos); 306 } 307 #endif 308 309 static struct ctl_table net_core_table[] = { 310 #ifdef CONFIG_NET 311 { 312 .procname = "wmem_max", 313 .data = &sysctl_wmem_max, 314 .maxlen = sizeof(int), 315 .mode = 0644, 316 .proc_handler = proc_dointvec_minmax, 317 .extra1 = &min_sndbuf, 318 }, 319 { 320 .procname = "rmem_max", 321 .data = &sysctl_rmem_max, 322 .maxlen = sizeof(int), 323 .mode = 0644, 324 .proc_handler = proc_dointvec_minmax, 325 .extra1 = &min_rcvbuf, 326 }, 327 { 328 .procname = "wmem_default", 329 .data = &sysctl_wmem_default, 330 .maxlen = sizeof(int), 331 .mode = 0644, 332 .proc_handler = proc_dointvec_minmax, 333 .extra1 = &min_sndbuf, 334 }, 335 { 336 .procname = "rmem_default", 337 .data = &sysctl_rmem_default, 338 .maxlen = sizeof(int), 339 .mode = 0644, 340 .proc_handler = proc_dointvec_minmax, 341 .extra1 = &min_rcvbuf, 342 }, 343 { 344 .procname = "dev_weight", 345 .data = &weight_p, 346 .maxlen = sizeof(int), 347 .mode = 0644, 348 .proc_handler = proc_do_dev_weight, 349 }, 350 { 351 .procname = "dev_weight_rx_bias", 352 .data = &dev_weight_rx_bias, 353 .maxlen = sizeof(int), 354 .mode = 0644, 355 .proc_handler = proc_do_dev_weight, 356 }, 357 { 358 .procname = "dev_weight_tx_bias", 359 .data = &dev_weight_tx_bias, 360 .maxlen = sizeof(int), 361 .mode = 0644, 362 .proc_handler = proc_do_dev_weight, 363 }, 364 { 365 .procname = "netdev_max_backlog", 366 .data = &netdev_max_backlog, 367 .maxlen = sizeof(int), 368 .mode = 0644, 369 .proc_handler = proc_dointvec 370 }, 371 { 372 .procname = "netdev_rss_key", 373 .data = &netdev_rss_key, 374 .maxlen = sizeof(int), 375 .mode = 0444, 376 .proc_handler = proc_do_rss_key, 377 }, 378 #ifdef CONFIG_BPF_JIT 379 { 380 .procname = "bpf_jit_enable", 381 .data = &bpf_jit_enable, 382 .maxlen = sizeof(int), 383 .mode = 0644, 384 .proc_handler = proc_dointvec_minmax_bpf_enable, 385 # ifdef CONFIG_BPF_JIT_ALWAYS_ON 386 .extra1 = SYSCTL_ONE, 387 .extra2 = SYSCTL_ONE, 388 # else 389 .extra1 = SYSCTL_ZERO, 390 .extra2 = &two, 391 # endif 392 }, 393 # ifdef CONFIG_HAVE_EBPF_JIT 394 { 395 .procname = "bpf_jit_harden", 396 .data = &bpf_jit_harden, 397 .maxlen = sizeof(int), 398 .mode = 0600, 399 .proc_handler = proc_dointvec_minmax_bpf_restricted, 400 .extra1 = SYSCTL_ZERO, 401 .extra2 = &two, 402 }, 403 { 404 .procname = "bpf_jit_kallsyms", 405 .data = &bpf_jit_kallsyms, 406 .maxlen = sizeof(int), 407 .mode = 0600, 408 .proc_handler = proc_dointvec_minmax_bpf_restricted, 409 .extra1 = SYSCTL_ZERO, 410 .extra2 = SYSCTL_ONE, 411 }, 412 # endif 413 { 414 .procname = "bpf_jit_limit", 415 .data = &bpf_jit_limit, 416 .maxlen = sizeof(long), 417 .mode = 0600, 418 .proc_handler = proc_dolongvec_minmax_bpf_restricted, 419 .extra1 = &long_one, 420 .extra2 = &long_max, 421 }, 422 #endif 423 { 424 .procname = "netdev_tstamp_prequeue", 425 .data = &netdev_tstamp_prequeue, 426 .maxlen = sizeof(int), 427 .mode = 0644, 428 .proc_handler = proc_dointvec 429 }, 430 { 431 .procname = "message_cost", 432 .data = &net_ratelimit_state.interval, 433 .maxlen = sizeof(int), 434 .mode = 0644, 435 .proc_handler = proc_dointvec_jiffies, 436 }, 437 { 438 .procname = "message_burst", 439 .data = &net_ratelimit_state.burst, 440 .maxlen = sizeof(int), 441 .mode = 0644, 442 .proc_handler = proc_dointvec, 443 }, 444 { 445 .procname = "optmem_max", 446 .data = &sysctl_optmem_max, 447 .maxlen = sizeof(int), 448 .mode = 0644, 449 .proc_handler = proc_dointvec 450 }, 451 { 452 .procname = "tstamp_allow_data", 453 .data = &sysctl_tstamp_allow_data, 454 .maxlen = sizeof(int), 455 .mode = 0644, 456 .proc_handler = proc_dointvec_minmax, 457 .extra1 = SYSCTL_ZERO, 458 .extra2 = SYSCTL_ONE 459 }, 460 #ifdef CONFIG_RPS 461 { 462 .procname = "rps_sock_flow_entries", 463 .maxlen = sizeof(int), 464 .mode = 0644, 465 .proc_handler = rps_sock_flow_sysctl 466 }, 467 #endif 468 #ifdef CONFIG_NET_FLOW_LIMIT 469 { 470 .procname = "flow_limit_cpu_bitmap", 471 .mode = 0644, 472 .proc_handler = flow_limit_cpu_sysctl 473 }, 474 { 475 .procname = "flow_limit_table_len", 476 .data = &netdev_flow_limit_table_len, 477 .maxlen = sizeof(int), 478 .mode = 0644, 479 .proc_handler = flow_limit_table_len_sysctl 480 }, 481 #endif /* CONFIG_NET_FLOW_LIMIT */ 482 #ifdef CONFIG_NET_RX_BUSY_POLL 483 { 484 .procname = "busy_poll", 485 .data = &sysctl_net_busy_poll, 486 .maxlen = sizeof(unsigned int), 487 .mode = 0644, 488 .proc_handler = proc_dointvec_minmax, 489 .extra1 = SYSCTL_ZERO, 490 }, 491 { 492 .procname = "busy_read", 493 .data = &sysctl_net_busy_read, 494 .maxlen = sizeof(unsigned int), 495 .mode = 0644, 496 .proc_handler = proc_dointvec_minmax, 497 .extra1 = SYSCTL_ZERO, 498 }, 499 #endif 500 #ifdef CONFIG_NET_SCHED 501 { 502 .procname = "default_qdisc", 503 .mode = 0644, 504 .maxlen = IFNAMSIZ, 505 .proc_handler = set_default_qdisc 506 }, 507 #endif 508 #endif /* CONFIG_NET */ 509 { 510 .procname = "netdev_budget", 511 .data = &netdev_budget, 512 .maxlen = sizeof(int), 513 .mode = 0644, 514 .proc_handler = proc_dointvec 515 }, 516 { 517 .procname = "warnings", 518 .data = &net_msg_warn, 519 .maxlen = sizeof(int), 520 .mode = 0644, 521 .proc_handler = proc_dointvec 522 }, 523 { 524 .procname = "max_skb_frags", 525 .data = &sysctl_max_skb_frags, 526 .maxlen = sizeof(int), 527 .mode = 0644, 528 .proc_handler = proc_dointvec_minmax, 529 .extra1 = SYSCTL_ONE, 530 .extra2 = &max_skb_frags, 531 }, 532 { 533 .procname = "netdev_budget_usecs", 534 .data = &netdev_budget_usecs, 535 .maxlen = sizeof(unsigned int), 536 .mode = 0644, 537 .proc_handler = proc_dointvec_minmax, 538 .extra1 = SYSCTL_ZERO, 539 }, 540 { 541 .procname = "fb_tunnels_only_for_init_net", 542 .data = &sysctl_fb_tunnels_only_for_init_net, 543 .maxlen = sizeof(int), 544 .mode = 0644, 545 .proc_handler = proc_dointvec_minmax, 546 .extra1 = SYSCTL_ZERO, 547 .extra2 = SYSCTL_ONE, 548 }, 549 { 550 .procname = "devconf_inherit_init_net", 551 .data = &sysctl_devconf_inherit_init_net, 552 .maxlen = sizeof(int), 553 .mode = 0644, 554 .proc_handler = proc_dointvec_minmax, 555 .extra1 = SYSCTL_ZERO, 556 .extra2 = &two, 557 }, 558 { 559 .procname = "high_order_alloc_disable", 560 .data = &net_high_order_alloc_disable_key.key, 561 .maxlen = sizeof(net_high_order_alloc_disable_key), 562 .mode = 0644, 563 .proc_handler = proc_do_static_key, 564 }, 565 { 566 .procname = "gro_normal_batch", 567 .data = &gro_normal_batch, 568 .maxlen = sizeof(unsigned int), 569 .mode = 0644, 570 .proc_handler = proc_dointvec_minmax, 571 .extra1 = SYSCTL_ONE, 572 }, 573 { } 574 }; 575 576 static struct ctl_table netns_core_table[] = { 577 { 578 .procname = "somaxconn", 579 .data = &init_net.core.sysctl_somaxconn, 580 .maxlen = sizeof(int), 581 .mode = 0644, 582 .extra1 = SYSCTL_ZERO, 583 .proc_handler = proc_dointvec_minmax 584 }, 585 { } 586 }; 587 588 static __net_init int sysctl_core_net_init(struct net *net) 589 { 590 struct ctl_table *tbl; 591 592 tbl = netns_core_table; 593 if (!net_eq(net, &init_net)) { 594 tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL); 595 if (tbl == NULL) 596 goto err_dup; 597 598 tbl[0].data = &net->core.sysctl_somaxconn; 599 600 /* Don't export any sysctls to unprivileged users */ 601 if (net->user_ns != &init_user_ns) { 602 tbl[0].procname = NULL; 603 } 604 } 605 606 net->core.sysctl_hdr = register_net_sysctl(net, "net/core", tbl); 607 if (net->core.sysctl_hdr == NULL) 608 goto err_reg; 609 610 return 0; 611 612 err_reg: 613 if (tbl != netns_core_table) 614 kfree(tbl); 615 err_dup: 616 return -ENOMEM; 617 } 618 619 static __net_exit void sysctl_core_net_exit(struct net *net) 620 { 621 struct ctl_table *tbl; 622 623 tbl = net->core.sysctl_hdr->ctl_table_arg; 624 unregister_net_sysctl_table(net->core.sysctl_hdr); 625 BUG_ON(tbl == netns_core_table); 626 kfree(tbl); 627 } 628 629 static __net_initdata struct pernet_operations sysctl_core_ops = { 630 .init = sysctl_core_net_init, 631 .exit = sysctl_core_net_exit, 632 }; 633 634 static __init int sysctl_core_init(void) 635 { 636 register_net_sysctl(&init_net, "net/core", net_core_table); 637 return register_pernet_subsys(&sysctl_core_ops); 638 } 639 640 fs_initcall(sysctl_core_init); 641