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 ushort_max = USHRT_MAX; 28 29 #ifdef CONFIG_RPS 30 static int rps_sock_flow_sysctl(struct ctl_table *table, int write, 31 void __user *buffer, size_t *lenp, loff_t *ppos) 32 { 33 unsigned int orig_size, size; 34 int ret, i; 35 struct ctl_table tmp = { 36 .data = &size, 37 .maxlen = sizeof(size), 38 .mode = table->mode 39 }; 40 struct rps_sock_flow_table *orig_sock_table, *sock_table; 41 static DEFINE_MUTEX(sock_flow_mutex); 42 43 mutex_lock(&sock_flow_mutex); 44 45 orig_sock_table = rcu_dereference_protected(rps_sock_flow_table, 46 lockdep_is_held(&sock_flow_mutex)); 47 size = orig_size = orig_sock_table ? orig_sock_table->mask + 1 : 0; 48 49 ret = proc_dointvec(&tmp, write, buffer, lenp, ppos); 50 51 if (write) { 52 if (size) { 53 if (size > 1<<30) { 54 /* Enforce limit to prevent overflow */ 55 mutex_unlock(&sock_flow_mutex); 56 return -EINVAL; 57 } 58 size = roundup_pow_of_two(size); 59 if (size != orig_size) { 60 sock_table = 61 vmalloc(RPS_SOCK_FLOW_TABLE_SIZE(size)); 62 if (!sock_table) { 63 mutex_unlock(&sock_flow_mutex); 64 return -ENOMEM; 65 } 66 67 sock_table->mask = size - 1; 68 } else 69 sock_table = orig_sock_table; 70 71 for (i = 0; i < size; i++) 72 sock_table->ents[i] = RPS_NO_CPU; 73 } else 74 sock_table = NULL; 75 76 if (sock_table != orig_sock_table) { 77 rcu_assign_pointer(rps_sock_flow_table, sock_table); 78 if (sock_table) 79 static_key_slow_inc(&rps_needed); 80 if (orig_sock_table) { 81 static_key_slow_dec(&rps_needed); 82 synchronize_rcu(); 83 vfree(orig_sock_table); 84 } 85 } 86 } 87 88 mutex_unlock(&sock_flow_mutex); 89 90 return ret; 91 } 92 #endif /* CONFIG_RPS */ 93 94 #ifdef CONFIG_NET_FLOW_LIMIT 95 static DEFINE_MUTEX(flow_limit_update_mutex); 96 97 static int flow_limit_cpu_sysctl(struct ctl_table *table, int write, 98 void __user *buffer, size_t *lenp, 99 loff_t *ppos) 100 { 101 struct sd_flow_limit *cur; 102 struct softnet_data *sd; 103 cpumask_var_t mask; 104 int i, len, ret = 0; 105 106 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) 107 return -ENOMEM; 108 109 if (write) { 110 ret = cpumask_parse_user(buffer, *lenp, mask); 111 if (ret) 112 goto done; 113 114 mutex_lock(&flow_limit_update_mutex); 115 len = sizeof(*cur) + netdev_flow_limit_table_len; 116 for_each_possible_cpu(i) { 117 sd = &per_cpu(softnet_data, i); 118 cur = rcu_dereference_protected(sd->flow_limit, 119 lockdep_is_held(&flow_limit_update_mutex)); 120 if (cur && !cpumask_test_cpu(i, mask)) { 121 RCU_INIT_POINTER(sd->flow_limit, NULL); 122 synchronize_rcu(); 123 kfree(cur); 124 } else if (!cur && cpumask_test_cpu(i, mask)) { 125 cur = kzalloc_node(len, GFP_KERNEL, 126 cpu_to_node(i)); 127 if (!cur) { 128 /* not unwinding previous changes */ 129 ret = -ENOMEM; 130 goto write_unlock; 131 } 132 cur->num_buckets = netdev_flow_limit_table_len; 133 rcu_assign_pointer(sd->flow_limit, cur); 134 } 135 } 136 write_unlock: 137 mutex_unlock(&flow_limit_update_mutex); 138 } else { 139 char kbuf[128]; 140 141 if (*ppos || !*lenp) { 142 *lenp = 0; 143 goto done; 144 } 145 146 cpumask_clear(mask); 147 rcu_read_lock(); 148 for_each_possible_cpu(i) { 149 sd = &per_cpu(softnet_data, i); 150 if (rcu_dereference(sd->flow_limit)) 151 cpumask_set_cpu(i, mask); 152 } 153 rcu_read_unlock(); 154 155 len = min(sizeof(kbuf) - 1, *lenp); 156 len = cpumask_scnprintf(kbuf, len, mask); 157 if (!len) { 158 *lenp = 0; 159 goto done; 160 } 161 if (len < *lenp) 162 kbuf[len++] = '\n'; 163 if (copy_to_user(buffer, kbuf, len)) { 164 ret = -EFAULT; 165 goto done; 166 } 167 *lenp = len; 168 *ppos += len; 169 } 170 171 done: 172 free_cpumask_var(mask); 173 return ret; 174 } 175 176 static int flow_limit_table_len_sysctl(struct ctl_table *table, int write, 177 void __user *buffer, size_t *lenp, 178 loff_t *ppos) 179 { 180 unsigned int old, *ptr; 181 int ret; 182 183 mutex_lock(&flow_limit_update_mutex); 184 185 ptr = table->data; 186 old = *ptr; 187 ret = proc_dointvec(table, write, buffer, lenp, ppos); 188 if (!ret && write && !is_power_of_2(*ptr)) { 189 *ptr = old; 190 ret = -EINVAL; 191 } 192 193 mutex_unlock(&flow_limit_update_mutex); 194 return ret; 195 } 196 #endif /* CONFIG_NET_FLOW_LIMIT */ 197 198 #ifdef CONFIG_NET_SCHED 199 static int set_default_qdisc(struct ctl_table *table, int write, 200 void __user *buffer, size_t *lenp, loff_t *ppos) 201 { 202 char id[IFNAMSIZ]; 203 struct ctl_table tbl = { 204 .data = id, 205 .maxlen = IFNAMSIZ, 206 }; 207 int ret; 208 209 qdisc_get_default(id, IFNAMSIZ); 210 211 ret = proc_dostring(&tbl, write, buffer, lenp, ppos); 212 if (write && ret == 0) 213 ret = qdisc_set_default(id); 214 return ret; 215 } 216 #endif 217 218 static struct ctl_table net_core_table[] = { 219 #ifdef CONFIG_NET 220 { 221 .procname = "wmem_max", 222 .data = &sysctl_wmem_max, 223 .maxlen = sizeof(int), 224 .mode = 0644, 225 .proc_handler = proc_dointvec_minmax, 226 .extra1 = &one, 227 }, 228 { 229 .procname = "rmem_max", 230 .data = &sysctl_rmem_max, 231 .maxlen = sizeof(int), 232 .mode = 0644, 233 .proc_handler = proc_dointvec_minmax, 234 .extra1 = &one, 235 }, 236 { 237 .procname = "wmem_default", 238 .data = &sysctl_wmem_default, 239 .maxlen = sizeof(int), 240 .mode = 0644, 241 .proc_handler = proc_dointvec_minmax, 242 .extra1 = &one, 243 }, 244 { 245 .procname = "rmem_default", 246 .data = &sysctl_rmem_default, 247 .maxlen = sizeof(int), 248 .mode = 0644, 249 .proc_handler = proc_dointvec_minmax, 250 .extra1 = &one, 251 }, 252 { 253 .procname = "dev_weight", 254 .data = &weight_p, 255 .maxlen = sizeof(int), 256 .mode = 0644, 257 .proc_handler = proc_dointvec 258 }, 259 { 260 .procname = "netdev_max_backlog", 261 .data = &netdev_max_backlog, 262 .maxlen = sizeof(int), 263 .mode = 0644, 264 .proc_handler = proc_dointvec 265 }, 266 #ifdef CONFIG_BPF_JIT 267 { 268 .procname = "bpf_jit_enable", 269 .data = &bpf_jit_enable, 270 .maxlen = sizeof(int), 271 .mode = 0644, 272 .proc_handler = proc_dointvec 273 }, 274 #endif 275 { 276 .procname = "netdev_tstamp_prequeue", 277 .data = &netdev_tstamp_prequeue, 278 .maxlen = sizeof(int), 279 .mode = 0644, 280 .proc_handler = proc_dointvec 281 }, 282 { 283 .procname = "message_cost", 284 .data = &net_ratelimit_state.interval, 285 .maxlen = sizeof(int), 286 .mode = 0644, 287 .proc_handler = proc_dointvec_jiffies, 288 }, 289 { 290 .procname = "message_burst", 291 .data = &net_ratelimit_state.burst, 292 .maxlen = sizeof(int), 293 .mode = 0644, 294 .proc_handler = proc_dointvec, 295 }, 296 { 297 .procname = "optmem_max", 298 .data = &sysctl_optmem_max, 299 .maxlen = sizeof(int), 300 .mode = 0644, 301 .proc_handler = proc_dointvec 302 }, 303 #ifdef CONFIG_RPS 304 { 305 .procname = "rps_sock_flow_entries", 306 .maxlen = sizeof(int), 307 .mode = 0644, 308 .proc_handler = rps_sock_flow_sysctl 309 }, 310 #endif 311 #ifdef CONFIG_NET_FLOW_LIMIT 312 { 313 .procname = "flow_limit_cpu_bitmap", 314 .mode = 0644, 315 .proc_handler = flow_limit_cpu_sysctl 316 }, 317 { 318 .procname = "flow_limit_table_len", 319 .data = &netdev_flow_limit_table_len, 320 .maxlen = sizeof(int), 321 .mode = 0644, 322 .proc_handler = flow_limit_table_len_sysctl 323 }, 324 #endif /* CONFIG_NET_FLOW_LIMIT */ 325 #ifdef CONFIG_NET_RX_BUSY_POLL 326 { 327 .procname = "busy_poll", 328 .data = &sysctl_net_busy_poll, 329 .maxlen = sizeof(unsigned int), 330 .mode = 0644, 331 .proc_handler = proc_dointvec 332 }, 333 { 334 .procname = "busy_read", 335 .data = &sysctl_net_busy_read, 336 .maxlen = sizeof(unsigned int), 337 .mode = 0644, 338 .proc_handler = proc_dointvec 339 }, 340 #endif 341 #ifdef CONFIG_NET_SCHED 342 { 343 .procname = "default_qdisc", 344 .mode = 0644, 345 .maxlen = IFNAMSIZ, 346 .proc_handler = set_default_qdisc 347 }, 348 #endif 349 #endif /* CONFIG_NET */ 350 { 351 .procname = "netdev_budget", 352 .data = &netdev_budget, 353 .maxlen = sizeof(int), 354 .mode = 0644, 355 .proc_handler = proc_dointvec 356 }, 357 { 358 .procname = "warnings", 359 .data = &net_msg_warn, 360 .maxlen = sizeof(int), 361 .mode = 0644, 362 .proc_handler = proc_dointvec 363 }, 364 { } 365 }; 366 367 static struct ctl_table netns_core_table[] = { 368 { 369 .procname = "somaxconn", 370 .data = &init_net.core.sysctl_somaxconn, 371 .maxlen = sizeof(int), 372 .mode = 0644, 373 .extra1 = &zero, 374 .extra2 = &ushort_max, 375 .proc_handler = proc_dointvec_minmax 376 }, 377 { } 378 }; 379 380 static __net_init int sysctl_core_net_init(struct net *net) 381 { 382 struct ctl_table *tbl; 383 384 net->core.sysctl_somaxconn = SOMAXCONN; 385 386 tbl = netns_core_table; 387 if (!net_eq(net, &init_net)) { 388 tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL); 389 if (tbl == NULL) 390 goto err_dup; 391 392 tbl[0].data = &net->core.sysctl_somaxconn; 393 394 /* Don't export any sysctls to unprivileged users */ 395 if (net->user_ns != &init_user_ns) { 396 tbl[0].procname = NULL; 397 } 398 } 399 400 net->core.sysctl_hdr = register_net_sysctl(net, "net/core", tbl); 401 if (net->core.sysctl_hdr == NULL) 402 goto err_reg; 403 404 return 0; 405 406 err_reg: 407 if (tbl != netns_core_table) 408 kfree(tbl); 409 err_dup: 410 return -ENOMEM; 411 } 412 413 static __net_exit void sysctl_core_net_exit(struct net *net) 414 { 415 struct ctl_table *tbl; 416 417 tbl = net->core.sysctl_hdr->ctl_table_arg; 418 unregister_net_sysctl_table(net->core.sysctl_hdr); 419 BUG_ON(tbl == netns_core_table); 420 kfree(tbl); 421 } 422 423 static __net_initdata struct pernet_operations sysctl_core_ops = { 424 .init = sysctl_core_net_init, 425 .exit = sysctl_core_net_exit, 426 }; 427 428 static __init int sysctl_core_init(void) 429 { 430 register_net_sysctl(&init_net, "net/core", net_core_table); 431 return register_pernet_subsys(&sysctl_core_ops); 432 } 433 434 fs_initcall(sysctl_core_init); 435