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 if (orig_sock_table) { 85 static_key_slow_dec(&rps_needed); 86 synchronize_rcu(); 87 vfree(orig_sock_table); 88 } 89 } 90 } 91 92 mutex_unlock(&sock_flow_mutex); 93 94 return ret; 95 } 96 #endif /* CONFIG_RPS */ 97 98 #ifdef CONFIG_NET_FLOW_LIMIT 99 static DEFINE_MUTEX(flow_limit_update_mutex); 100 101 static int flow_limit_cpu_sysctl(struct ctl_table *table, int write, 102 void __user *buffer, size_t *lenp, 103 loff_t *ppos) 104 { 105 struct sd_flow_limit *cur; 106 struct softnet_data *sd; 107 cpumask_var_t mask; 108 int i, len, ret = 0; 109 110 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) 111 return -ENOMEM; 112 113 if (write) { 114 ret = cpumask_parse_user(buffer, *lenp, mask); 115 if (ret) 116 goto done; 117 118 mutex_lock(&flow_limit_update_mutex); 119 len = sizeof(*cur) + netdev_flow_limit_table_len; 120 for_each_possible_cpu(i) { 121 sd = &per_cpu(softnet_data, i); 122 cur = rcu_dereference_protected(sd->flow_limit, 123 lockdep_is_held(&flow_limit_update_mutex)); 124 if (cur && !cpumask_test_cpu(i, mask)) { 125 RCU_INIT_POINTER(sd->flow_limit, NULL); 126 synchronize_rcu(); 127 kfree(cur); 128 } else if (!cur && cpumask_test_cpu(i, mask)) { 129 cur = kzalloc_node(len, GFP_KERNEL, 130 cpu_to_node(i)); 131 if (!cur) { 132 /* not unwinding previous changes */ 133 ret = -ENOMEM; 134 goto write_unlock; 135 } 136 cur->num_buckets = netdev_flow_limit_table_len; 137 rcu_assign_pointer(sd->flow_limit, cur); 138 } 139 } 140 write_unlock: 141 mutex_unlock(&flow_limit_update_mutex); 142 } else { 143 char kbuf[128]; 144 145 if (*ppos || !*lenp) { 146 *lenp = 0; 147 goto done; 148 } 149 150 cpumask_clear(mask); 151 rcu_read_lock(); 152 for_each_possible_cpu(i) { 153 sd = &per_cpu(softnet_data, i); 154 if (rcu_dereference(sd->flow_limit)) 155 cpumask_set_cpu(i, mask); 156 } 157 rcu_read_unlock(); 158 159 len = min(sizeof(kbuf) - 1, *lenp); 160 len = scnprintf(kbuf, len, "%*pb", cpumask_pr_args(mask)); 161 if (!len) { 162 *lenp = 0; 163 goto done; 164 } 165 if (len < *lenp) 166 kbuf[len++] = '\n'; 167 if (copy_to_user(buffer, kbuf, len)) { 168 ret = -EFAULT; 169 goto done; 170 } 171 *lenp = len; 172 *ppos += len; 173 } 174 175 done: 176 free_cpumask_var(mask); 177 return ret; 178 } 179 180 static int flow_limit_table_len_sysctl(struct ctl_table *table, int write, 181 void __user *buffer, size_t *lenp, 182 loff_t *ppos) 183 { 184 unsigned int old, *ptr; 185 int ret; 186 187 mutex_lock(&flow_limit_update_mutex); 188 189 ptr = table->data; 190 old = *ptr; 191 ret = proc_dointvec(table, write, buffer, lenp, ppos); 192 if (!ret && write && !is_power_of_2(*ptr)) { 193 *ptr = old; 194 ret = -EINVAL; 195 } 196 197 mutex_unlock(&flow_limit_update_mutex); 198 return ret; 199 } 200 #endif /* CONFIG_NET_FLOW_LIMIT */ 201 202 #ifdef CONFIG_NET_SCHED 203 static int set_default_qdisc(struct ctl_table *table, int write, 204 void __user *buffer, size_t *lenp, loff_t *ppos) 205 { 206 char id[IFNAMSIZ]; 207 struct ctl_table tbl = { 208 .data = id, 209 .maxlen = IFNAMSIZ, 210 }; 211 int ret; 212 213 qdisc_get_default(id, IFNAMSIZ); 214 215 ret = proc_dostring(&tbl, write, buffer, lenp, ppos); 216 if (write && ret == 0) 217 ret = qdisc_set_default(id); 218 return ret; 219 } 220 #endif 221 222 static int proc_do_rss_key(struct ctl_table *table, int write, 223 void __user *buffer, size_t *lenp, loff_t *ppos) 224 { 225 struct ctl_table fake_table; 226 char buf[NETDEV_RSS_KEY_LEN * 3]; 227 228 snprintf(buf, sizeof(buf), "%*phC", NETDEV_RSS_KEY_LEN, netdev_rss_key); 229 fake_table.data = buf; 230 fake_table.maxlen = sizeof(buf); 231 return proc_dostring(&fake_table, write, buffer, lenp, ppos); 232 } 233 234 static struct ctl_table net_core_table[] = { 235 #ifdef CONFIG_NET 236 { 237 .procname = "wmem_max", 238 .data = &sysctl_wmem_max, 239 .maxlen = sizeof(int), 240 .mode = 0644, 241 .proc_handler = proc_dointvec_minmax, 242 .extra1 = &min_sndbuf, 243 }, 244 { 245 .procname = "rmem_max", 246 .data = &sysctl_rmem_max, 247 .maxlen = sizeof(int), 248 .mode = 0644, 249 .proc_handler = proc_dointvec_minmax, 250 .extra1 = &min_rcvbuf, 251 }, 252 { 253 .procname = "wmem_default", 254 .data = &sysctl_wmem_default, 255 .maxlen = sizeof(int), 256 .mode = 0644, 257 .proc_handler = proc_dointvec_minmax, 258 .extra1 = &min_sndbuf, 259 }, 260 { 261 .procname = "rmem_default", 262 .data = &sysctl_rmem_default, 263 .maxlen = sizeof(int), 264 .mode = 0644, 265 .proc_handler = proc_dointvec_minmax, 266 .extra1 = &min_rcvbuf, 267 }, 268 { 269 .procname = "dev_weight", 270 .data = &weight_p, 271 .maxlen = sizeof(int), 272 .mode = 0644, 273 .proc_handler = proc_dointvec 274 }, 275 { 276 .procname = "netdev_max_backlog", 277 .data = &netdev_max_backlog, 278 .maxlen = sizeof(int), 279 .mode = 0644, 280 .proc_handler = proc_dointvec 281 }, 282 { 283 .procname = "netdev_rss_key", 284 .data = &netdev_rss_key, 285 .maxlen = sizeof(int), 286 .mode = 0444, 287 .proc_handler = proc_do_rss_key, 288 }, 289 #ifdef CONFIG_BPF_JIT 290 { 291 .procname = "bpf_jit_enable", 292 .data = &bpf_jit_enable, 293 .maxlen = sizeof(int), 294 .mode = 0644, 295 .proc_handler = proc_dointvec 296 }, 297 #endif 298 { 299 .procname = "netdev_tstamp_prequeue", 300 .data = &netdev_tstamp_prequeue, 301 .maxlen = sizeof(int), 302 .mode = 0644, 303 .proc_handler = proc_dointvec 304 }, 305 { 306 .procname = "message_cost", 307 .data = &net_ratelimit_state.interval, 308 .maxlen = sizeof(int), 309 .mode = 0644, 310 .proc_handler = proc_dointvec_jiffies, 311 }, 312 { 313 .procname = "message_burst", 314 .data = &net_ratelimit_state.burst, 315 .maxlen = sizeof(int), 316 .mode = 0644, 317 .proc_handler = proc_dointvec, 318 }, 319 { 320 .procname = "optmem_max", 321 .data = &sysctl_optmem_max, 322 .maxlen = sizeof(int), 323 .mode = 0644, 324 .proc_handler = proc_dointvec 325 }, 326 { 327 .procname = "tstamp_allow_data", 328 .data = &sysctl_tstamp_allow_data, 329 .maxlen = sizeof(int), 330 .mode = 0644, 331 .proc_handler = proc_dointvec_minmax, 332 .extra1 = &zero, 333 .extra2 = &one 334 }, 335 #ifdef CONFIG_RPS 336 { 337 .procname = "rps_sock_flow_entries", 338 .maxlen = sizeof(int), 339 .mode = 0644, 340 .proc_handler = rps_sock_flow_sysctl 341 }, 342 #endif 343 #ifdef CONFIG_NET_FLOW_LIMIT 344 { 345 .procname = "flow_limit_cpu_bitmap", 346 .mode = 0644, 347 .proc_handler = flow_limit_cpu_sysctl 348 }, 349 { 350 .procname = "flow_limit_table_len", 351 .data = &netdev_flow_limit_table_len, 352 .maxlen = sizeof(int), 353 .mode = 0644, 354 .proc_handler = flow_limit_table_len_sysctl 355 }, 356 #endif /* CONFIG_NET_FLOW_LIMIT */ 357 #ifdef CONFIG_NET_RX_BUSY_POLL 358 { 359 .procname = "busy_poll", 360 .data = &sysctl_net_busy_poll, 361 .maxlen = sizeof(unsigned int), 362 .mode = 0644, 363 .proc_handler = proc_dointvec 364 }, 365 { 366 .procname = "busy_read", 367 .data = &sysctl_net_busy_read, 368 .maxlen = sizeof(unsigned int), 369 .mode = 0644, 370 .proc_handler = proc_dointvec 371 }, 372 #endif 373 #ifdef CONFIG_NET_SCHED 374 { 375 .procname = "default_qdisc", 376 .mode = 0644, 377 .maxlen = IFNAMSIZ, 378 .proc_handler = set_default_qdisc 379 }, 380 #endif 381 #endif /* CONFIG_NET */ 382 { 383 .procname = "netdev_budget", 384 .data = &netdev_budget, 385 .maxlen = sizeof(int), 386 .mode = 0644, 387 .proc_handler = proc_dointvec 388 }, 389 { 390 .procname = "warnings", 391 .data = &net_msg_warn, 392 .maxlen = sizeof(int), 393 .mode = 0644, 394 .proc_handler = proc_dointvec 395 }, 396 { 397 .procname = "max_skb_frags", 398 .data = &sysctl_max_skb_frags, 399 .maxlen = sizeof(int), 400 .mode = 0644, 401 .proc_handler = proc_dointvec_minmax, 402 .extra1 = &one, 403 .extra2 = &max_skb_frags, 404 }, 405 { } 406 }; 407 408 static struct ctl_table netns_core_table[] = { 409 { 410 .procname = "somaxconn", 411 .data = &init_net.core.sysctl_somaxconn, 412 .maxlen = sizeof(int), 413 .mode = 0644, 414 .extra1 = &zero, 415 .proc_handler = proc_dointvec_minmax 416 }, 417 { } 418 }; 419 420 static __net_init int sysctl_core_net_init(struct net *net) 421 { 422 struct ctl_table *tbl; 423 424 net->core.sysctl_somaxconn = SOMAXCONN; 425 426 tbl = netns_core_table; 427 if (!net_eq(net, &init_net)) { 428 tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL); 429 if (tbl == NULL) 430 goto err_dup; 431 432 tbl[0].data = &net->core.sysctl_somaxconn; 433 434 /* Don't export any sysctls to unprivileged users */ 435 if (net->user_ns != &init_user_ns) { 436 tbl[0].procname = NULL; 437 } 438 } 439 440 net->core.sysctl_hdr = register_net_sysctl(net, "net/core", tbl); 441 if (net->core.sysctl_hdr == NULL) 442 goto err_reg; 443 444 return 0; 445 446 err_reg: 447 if (tbl != netns_core_table) 448 kfree(tbl); 449 err_dup: 450 return -ENOMEM; 451 } 452 453 static __net_exit void sysctl_core_net_exit(struct net *net) 454 { 455 struct ctl_table *tbl; 456 457 tbl = net->core.sysctl_hdr->ctl_table_arg; 458 unregister_net_sysctl_table(net->core.sysctl_hdr); 459 BUG_ON(tbl == netns_core_table); 460 kfree(tbl); 461 } 462 463 static __net_initdata struct pernet_operations sysctl_core_ops = { 464 .init = sysctl_core_net_init, 465 .exit = sysctl_core_net_exit, 466 }; 467 468 static __init int sysctl_core_init(void) 469 { 470 register_net_sysctl(&init_net, "net/core", net_core_table); 471 return register_pernet_subsys(&sysctl_core_ops); 472 } 473 474 fs_initcall(sysctl_core_init); 475