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