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