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