1 /* -*- linux-c -*- 2 * sysctl_net_core.c: sysctl interface to net core subsystem. 3 * 4 * Begun April 1, 1996, Mike Shaver. 5 * Added /proc/sys/net/core directory entry (empty =) ). [MS] 6 */ 7 8 #include <linux/mm.h> 9 #include <linux/sysctl.h> 10 #include <linux/module.h> 11 #include <linux/socket.h> 12 #include <linux/netdevice.h> 13 #include <linux/ratelimit.h> 14 #include <linux/vmalloc.h> 15 #include <linux/init.h> 16 #include <linux/slab.h> 17 #include <linux/kmemleak.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 min_sndbuf = SOCK_MIN_SNDBUF; 28 static int min_rcvbuf = SOCK_MIN_RCVBUF; 29 static int max_skb_frags = MAX_SKB_FRAGS; 30 31 static int net_msg_warn; /* Unused, but still a sysctl */ 32 33 #ifdef CONFIG_RPS 34 static int rps_sock_flow_sysctl(struct ctl_table *table, int write, 35 void __user *buffer, size_t *lenp, loff_t *ppos) 36 { 37 unsigned int orig_size, size; 38 int ret, i; 39 struct ctl_table tmp = { 40 .data = &size, 41 .maxlen = sizeof(size), 42 .mode = table->mode 43 }; 44 struct rps_sock_flow_table *orig_sock_table, *sock_table; 45 static DEFINE_MUTEX(sock_flow_mutex); 46 47 mutex_lock(&sock_flow_mutex); 48 49 orig_sock_table = rcu_dereference_protected(rps_sock_flow_table, 50 lockdep_is_held(&sock_flow_mutex)); 51 size = orig_size = orig_sock_table ? orig_sock_table->mask + 1 : 0; 52 53 ret = proc_dointvec(&tmp, write, buffer, lenp, ppos); 54 55 if (write) { 56 if (size) { 57 if (size > 1<<29) { 58 /* Enforce limit to prevent overflow */ 59 mutex_unlock(&sock_flow_mutex); 60 return -EINVAL; 61 } 62 size = roundup_pow_of_two(size); 63 if (size != orig_size) { 64 sock_table = 65 vmalloc(RPS_SOCK_FLOW_TABLE_SIZE(size)); 66 if (!sock_table) { 67 mutex_unlock(&sock_flow_mutex); 68 return -ENOMEM; 69 } 70 rps_cpu_mask = roundup_pow_of_two(nr_cpu_ids) - 1; 71 sock_table->mask = size - 1; 72 } else 73 sock_table = orig_sock_table; 74 75 for (i = 0; i < size; i++) 76 sock_table->ents[i] = RPS_NO_CPU; 77 } else 78 sock_table = NULL; 79 80 if (sock_table != orig_sock_table) { 81 rcu_assign_pointer(rps_sock_flow_table, sock_table); 82 if (sock_table) { 83 static_key_slow_inc(&rps_needed); 84 static_key_slow_inc(&rfs_needed); 85 } 86 if (orig_sock_table) { 87 static_key_slow_dec(&rps_needed); 88 static_key_slow_dec(&rfs_needed); 89 synchronize_rcu(); 90 vfree(orig_sock_table); 91 } 92 } 93 } 94 95 mutex_unlock(&sock_flow_mutex); 96 97 return ret; 98 } 99 #endif /* CONFIG_RPS */ 100 101 #ifdef CONFIG_NET_FLOW_LIMIT 102 static DEFINE_MUTEX(flow_limit_update_mutex); 103 104 static int flow_limit_cpu_sysctl(struct ctl_table *table, int write, 105 void __user *buffer, size_t *lenp, 106 loff_t *ppos) 107 { 108 struct sd_flow_limit *cur; 109 struct softnet_data *sd; 110 cpumask_var_t mask; 111 int i, len, ret = 0; 112 113 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) 114 return -ENOMEM; 115 116 if (write) { 117 ret = cpumask_parse_user(buffer, *lenp, mask); 118 if (ret) 119 goto done; 120 121 mutex_lock(&flow_limit_update_mutex); 122 len = sizeof(*cur) + netdev_flow_limit_table_len; 123 for_each_possible_cpu(i) { 124 sd = &per_cpu(softnet_data, i); 125 cur = rcu_dereference_protected(sd->flow_limit, 126 lockdep_is_held(&flow_limit_update_mutex)); 127 if (cur && !cpumask_test_cpu(i, mask)) { 128 RCU_INIT_POINTER(sd->flow_limit, NULL); 129 synchronize_rcu(); 130 kfree(cur); 131 } else if (!cur && cpumask_test_cpu(i, mask)) { 132 cur = kzalloc_node(len, GFP_KERNEL, 133 cpu_to_node(i)); 134 if (!cur) { 135 /* not unwinding previous changes */ 136 ret = -ENOMEM; 137 goto write_unlock; 138 } 139 cur->num_buckets = netdev_flow_limit_table_len; 140 rcu_assign_pointer(sd->flow_limit, cur); 141 } 142 } 143 write_unlock: 144 mutex_unlock(&flow_limit_update_mutex); 145 } else { 146 char kbuf[128]; 147 148 if (*ppos || !*lenp) { 149 *lenp = 0; 150 goto done; 151 } 152 153 cpumask_clear(mask); 154 rcu_read_lock(); 155 for_each_possible_cpu(i) { 156 sd = &per_cpu(softnet_data, i); 157 if (rcu_dereference(sd->flow_limit)) 158 cpumask_set_cpu(i, mask); 159 } 160 rcu_read_unlock(); 161 162 len = min(sizeof(kbuf) - 1, *lenp); 163 len = scnprintf(kbuf, len, "%*pb", cpumask_pr_args(mask)); 164 if (!len) { 165 *lenp = 0; 166 goto done; 167 } 168 if (len < *lenp) 169 kbuf[len++] = '\n'; 170 if (copy_to_user(buffer, kbuf, len)) { 171 ret = -EFAULT; 172 goto done; 173 } 174 *lenp = len; 175 *ppos += len; 176 } 177 178 done: 179 free_cpumask_var(mask); 180 return ret; 181 } 182 183 static int flow_limit_table_len_sysctl(struct ctl_table *table, int write, 184 void __user *buffer, size_t *lenp, 185 loff_t *ppos) 186 { 187 unsigned int old, *ptr; 188 int ret; 189 190 mutex_lock(&flow_limit_update_mutex); 191 192 ptr = table->data; 193 old = *ptr; 194 ret = proc_dointvec(table, write, buffer, lenp, ppos); 195 if (!ret && write && !is_power_of_2(*ptr)) { 196 *ptr = old; 197 ret = -EINVAL; 198 } 199 200 mutex_unlock(&flow_limit_update_mutex); 201 return ret; 202 } 203 #endif /* CONFIG_NET_FLOW_LIMIT */ 204 205 #ifdef CONFIG_NET_SCHED 206 static int set_default_qdisc(struct ctl_table *table, int write, 207 void __user *buffer, size_t *lenp, loff_t *ppos) 208 { 209 char id[IFNAMSIZ]; 210 struct ctl_table tbl = { 211 .data = id, 212 .maxlen = IFNAMSIZ, 213 }; 214 int ret; 215 216 qdisc_get_default(id, IFNAMSIZ); 217 218 ret = proc_dostring(&tbl, write, buffer, lenp, ppos); 219 if (write && ret == 0) 220 ret = qdisc_set_default(id); 221 return ret; 222 } 223 #endif 224 225 static int proc_do_dev_weight(struct ctl_table *table, int write, 226 void __user *buffer, size_t *lenp, loff_t *ppos) 227 { 228 int ret; 229 230 ret = proc_dointvec(table, write, buffer, lenp, ppos); 231 if (ret != 0) 232 return ret; 233 234 dev_rx_weight = weight_p * dev_weight_rx_bias; 235 dev_tx_weight = weight_p * dev_weight_tx_bias; 236 237 return ret; 238 } 239 240 static int proc_do_rss_key(struct ctl_table *table, int write, 241 void __user *buffer, size_t *lenp, loff_t *ppos) 242 { 243 struct ctl_table fake_table; 244 char buf[NETDEV_RSS_KEY_LEN * 3]; 245 246 snprintf(buf, sizeof(buf), "%*phC", NETDEV_RSS_KEY_LEN, netdev_rss_key); 247 fake_table.data = buf; 248 fake_table.maxlen = sizeof(buf); 249 return proc_dostring(&fake_table, write, buffer, lenp, ppos); 250 } 251 252 static struct ctl_table net_core_table[] = { 253 #ifdef CONFIG_NET 254 { 255 .procname = "wmem_max", 256 .data = &sysctl_wmem_max, 257 .maxlen = sizeof(int), 258 .mode = 0644, 259 .proc_handler = proc_dointvec_minmax, 260 .extra1 = &min_sndbuf, 261 }, 262 { 263 .procname = "rmem_max", 264 .data = &sysctl_rmem_max, 265 .maxlen = sizeof(int), 266 .mode = 0644, 267 .proc_handler = proc_dointvec_minmax, 268 .extra1 = &min_rcvbuf, 269 }, 270 { 271 .procname = "wmem_default", 272 .data = &sysctl_wmem_default, 273 .maxlen = sizeof(int), 274 .mode = 0644, 275 .proc_handler = proc_dointvec_minmax, 276 .extra1 = &min_sndbuf, 277 }, 278 { 279 .procname = "rmem_default", 280 .data = &sysctl_rmem_default, 281 .maxlen = sizeof(int), 282 .mode = 0644, 283 .proc_handler = proc_dointvec_minmax, 284 .extra1 = &min_rcvbuf, 285 }, 286 { 287 .procname = "dev_weight", 288 .data = &weight_p, 289 .maxlen = sizeof(int), 290 .mode = 0644, 291 .proc_handler = proc_do_dev_weight, 292 }, 293 { 294 .procname = "dev_weight_rx_bias", 295 .data = &dev_weight_rx_bias, 296 .maxlen = sizeof(int), 297 .mode = 0644, 298 .proc_handler = proc_do_dev_weight, 299 }, 300 { 301 .procname = "dev_weight_tx_bias", 302 .data = &dev_weight_tx_bias, 303 .maxlen = sizeof(int), 304 .mode = 0644, 305 .proc_handler = proc_do_dev_weight, 306 }, 307 { 308 .procname = "netdev_max_backlog", 309 .data = &netdev_max_backlog, 310 .maxlen = sizeof(int), 311 .mode = 0644, 312 .proc_handler = proc_dointvec 313 }, 314 { 315 .procname = "netdev_rss_key", 316 .data = &netdev_rss_key, 317 .maxlen = sizeof(int), 318 .mode = 0444, 319 .proc_handler = proc_do_rss_key, 320 }, 321 #ifdef CONFIG_BPF_JIT 322 { 323 .procname = "bpf_jit_enable", 324 .data = &bpf_jit_enable, 325 .maxlen = sizeof(int), 326 .mode = 0644, 327 .proc_handler = proc_dointvec 328 }, 329 # ifdef CONFIG_HAVE_EBPF_JIT 330 { 331 .procname = "bpf_jit_harden", 332 .data = &bpf_jit_harden, 333 .maxlen = sizeof(int), 334 .mode = 0600, 335 .proc_handler = proc_dointvec, 336 }, 337 { 338 .procname = "bpf_jit_kallsyms", 339 .data = &bpf_jit_kallsyms, 340 .maxlen = sizeof(int), 341 .mode = 0600, 342 .proc_handler = proc_dointvec, 343 }, 344 # endif 345 #endif 346 { 347 .procname = "netdev_tstamp_prequeue", 348 .data = &netdev_tstamp_prequeue, 349 .maxlen = sizeof(int), 350 .mode = 0644, 351 .proc_handler = proc_dointvec 352 }, 353 { 354 .procname = "message_cost", 355 .data = &net_ratelimit_state.interval, 356 .maxlen = sizeof(int), 357 .mode = 0644, 358 .proc_handler = proc_dointvec_jiffies, 359 }, 360 { 361 .procname = "message_burst", 362 .data = &net_ratelimit_state.burst, 363 .maxlen = sizeof(int), 364 .mode = 0644, 365 .proc_handler = proc_dointvec, 366 }, 367 { 368 .procname = "optmem_max", 369 .data = &sysctl_optmem_max, 370 .maxlen = sizeof(int), 371 .mode = 0644, 372 .proc_handler = proc_dointvec 373 }, 374 { 375 .procname = "tstamp_allow_data", 376 .data = &sysctl_tstamp_allow_data, 377 .maxlen = sizeof(int), 378 .mode = 0644, 379 .proc_handler = proc_dointvec_minmax, 380 .extra1 = &zero, 381 .extra2 = &one 382 }, 383 #ifdef CONFIG_RPS 384 { 385 .procname = "rps_sock_flow_entries", 386 .maxlen = sizeof(int), 387 .mode = 0644, 388 .proc_handler = rps_sock_flow_sysctl 389 }, 390 #endif 391 #ifdef CONFIG_NET_FLOW_LIMIT 392 { 393 .procname = "flow_limit_cpu_bitmap", 394 .mode = 0644, 395 .proc_handler = flow_limit_cpu_sysctl 396 }, 397 { 398 .procname = "flow_limit_table_len", 399 .data = &netdev_flow_limit_table_len, 400 .maxlen = sizeof(int), 401 .mode = 0644, 402 .proc_handler = flow_limit_table_len_sysctl 403 }, 404 #endif /* CONFIG_NET_FLOW_LIMIT */ 405 #ifdef CONFIG_NET_RX_BUSY_POLL 406 { 407 .procname = "busy_poll", 408 .data = &sysctl_net_busy_poll, 409 .maxlen = sizeof(unsigned int), 410 .mode = 0644, 411 .proc_handler = proc_dointvec_minmax, 412 .extra1 = &zero, 413 }, 414 { 415 .procname = "busy_read", 416 .data = &sysctl_net_busy_read, 417 .maxlen = sizeof(unsigned int), 418 .mode = 0644, 419 .proc_handler = proc_dointvec_minmax, 420 .extra1 = &zero, 421 }, 422 #endif 423 #ifdef CONFIG_NET_SCHED 424 { 425 .procname = "default_qdisc", 426 .mode = 0644, 427 .maxlen = IFNAMSIZ, 428 .proc_handler = set_default_qdisc 429 }, 430 #endif 431 #endif /* CONFIG_NET */ 432 { 433 .procname = "netdev_budget", 434 .data = &netdev_budget, 435 .maxlen = sizeof(int), 436 .mode = 0644, 437 .proc_handler = proc_dointvec 438 }, 439 { 440 .procname = "warnings", 441 .data = &net_msg_warn, 442 .maxlen = sizeof(int), 443 .mode = 0644, 444 .proc_handler = proc_dointvec 445 }, 446 { 447 .procname = "max_skb_frags", 448 .data = &sysctl_max_skb_frags, 449 .maxlen = sizeof(int), 450 .mode = 0644, 451 .proc_handler = proc_dointvec_minmax, 452 .extra1 = &one, 453 .extra2 = &max_skb_frags, 454 }, 455 { 456 .procname = "netdev_budget_usecs", 457 .data = &netdev_budget_usecs, 458 .maxlen = sizeof(unsigned int), 459 .mode = 0644, 460 .proc_handler = proc_dointvec_minmax, 461 .extra1 = &zero, 462 }, 463 { } 464 }; 465 466 static struct ctl_table netns_core_table[] = { 467 { 468 .procname = "somaxconn", 469 .data = &init_net.core.sysctl_somaxconn, 470 .maxlen = sizeof(int), 471 .mode = 0644, 472 .extra1 = &zero, 473 .proc_handler = proc_dointvec_minmax 474 }, 475 { } 476 }; 477 478 static __net_init int sysctl_core_net_init(struct net *net) 479 { 480 struct ctl_table *tbl; 481 482 net->core.sysctl_somaxconn = SOMAXCONN; 483 484 tbl = netns_core_table; 485 if (!net_eq(net, &init_net)) { 486 tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL); 487 if (tbl == NULL) 488 goto err_dup; 489 490 tbl[0].data = &net->core.sysctl_somaxconn; 491 492 /* Don't export any sysctls to unprivileged users */ 493 if (net->user_ns != &init_user_ns) { 494 tbl[0].procname = NULL; 495 } 496 } 497 498 net->core.sysctl_hdr = register_net_sysctl(net, "net/core", tbl); 499 if (net->core.sysctl_hdr == NULL) 500 goto err_reg; 501 502 return 0; 503 504 err_reg: 505 if (tbl != netns_core_table) 506 kfree(tbl); 507 err_dup: 508 return -ENOMEM; 509 } 510 511 static __net_exit void sysctl_core_net_exit(struct net *net) 512 { 513 struct ctl_table *tbl; 514 515 tbl = net->core.sysctl_hdr->ctl_table_arg; 516 unregister_net_sysctl_table(net->core.sysctl_hdr); 517 BUG_ON(tbl == netns_core_table); 518 kfree(tbl); 519 } 520 521 static __net_initdata struct pernet_operations sysctl_core_ops = { 522 .init = sysctl_core_net_init, 523 .exit = sysctl_core_net_exit, 524 }; 525 526 static __init int sysctl_core_init(void) 527 { 528 register_net_sysctl(&init_net, "net/core", net_core_table); 529 return register_pernet_subsys(&sysctl_core_ops); 530 } 531 532 fs_initcall(sysctl_core_init); 533