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 24 static int zero = 0; 25 static int one = 1; 26 static int ushort_max = USHRT_MAX; 27 28 #ifdef CONFIG_RPS 29 static int rps_sock_flow_sysctl(struct ctl_table *table, int write, 30 void __user *buffer, size_t *lenp, loff_t *ppos) 31 { 32 unsigned int orig_size, size; 33 int ret, i; 34 struct ctl_table tmp = { 35 .data = &size, 36 .maxlen = sizeof(size), 37 .mode = table->mode 38 }; 39 struct rps_sock_flow_table *orig_sock_table, *sock_table; 40 static DEFINE_MUTEX(sock_flow_mutex); 41 42 mutex_lock(&sock_flow_mutex); 43 44 orig_sock_table = rcu_dereference_protected(rps_sock_flow_table, 45 lockdep_is_held(&sock_flow_mutex)); 46 size = orig_size = orig_sock_table ? orig_sock_table->mask + 1 : 0; 47 48 ret = proc_dointvec(&tmp, write, buffer, lenp, ppos); 49 50 if (write) { 51 if (size) { 52 if (size > 1<<30) { 53 /* Enforce limit to prevent overflow */ 54 mutex_unlock(&sock_flow_mutex); 55 return -EINVAL; 56 } 57 size = roundup_pow_of_two(size); 58 if (size != orig_size) { 59 sock_table = 60 vmalloc(RPS_SOCK_FLOW_TABLE_SIZE(size)); 61 if (!sock_table) { 62 mutex_unlock(&sock_flow_mutex); 63 return -ENOMEM; 64 } 65 66 sock_table->mask = size - 1; 67 } else 68 sock_table = orig_sock_table; 69 70 for (i = 0; i < size; i++) 71 sock_table->ents[i] = RPS_NO_CPU; 72 } else 73 sock_table = NULL; 74 75 if (sock_table != orig_sock_table) { 76 rcu_assign_pointer(rps_sock_flow_table, sock_table); 77 if (sock_table) 78 static_key_slow_inc(&rps_needed); 79 if (orig_sock_table) { 80 static_key_slow_dec(&rps_needed); 81 synchronize_rcu(); 82 vfree(orig_sock_table); 83 } 84 } 85 } 86 87 mutex_unlock(&sock_flow_mutex); 88 89 return ret; 90 } 91 #endif /* CONFIG_RPS */ 92 93 #ifdef CONFIG_NET_FLOW_LIMIT 94 static DEFINE_MUTEX(flow_limit_update_mutex); 95 96 static int flow_limit_cpu_sysctl(struct ctl_table *table, int write, 97 void __user *buffer, size_t *lenp, 98 loff_t *ppos) 99 { 100 struct sd_flow_limit *cur; 101 struct softnet_data *sd; 102 cpumask_var_t mask; 103 int i, len, ret = 0; 104 105 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) 106 return -ENOMEM; 107 108 if (write) { 109 ret = cpumask_parse_user(buffer, *lenp, mask); 110 if (ret) 111 goto done; 112 113 mutex_lock(&flow_limit_update_mutex); 114 len = sizeof(*cur) + netdev_flow_limit_table_len; 115 for_each_possible_cpu(i) { 116 sd = &per_cpu(softnet_data, i); 117 cur = rcu_dereference_protected(sd->flow_limit, 118 lockdep_is_held(&flow_limit_update_mutex)); 119 if (cur && !cpumask_test_cpu(i, mask)) { 120 RCU_INIT_POINTER(sd->flow_limit, NULL); 121 synchronize_rcu(); 122 kfree(cur); 123 } else if (!cur && cpumask_test_cpu(i, mask)) { 124 cur = kzalloc(len, GFP_KERNEL); 125 if (!cur) { 126 /* not unwinding previous changes */ 127 ret = -ENOMEM; 128 goto write_unlock; 129 } 130 cur->num_buckets = netdev_flow_limit_table_len; 131 rcu_assign_pointer(sd->flow_limit, cur); 132 } 133 } 134 write_unlock: 135 mutex_unlock(&flow_limit_update_mutex); 136 } else { 137 char kbuf[128]; 138 139 if (*ppos || !*lenp) { 140 *lenp = 0; 141 goto done; 142 } 143 144 cpumask_clear(mask); 145 rcu_read_lock(); 146 for_each_possible_cpu(i) { 147 sd = &per_cpu(softnet_data, i); 148 if (rcu_dereference(sd->flow_limit)) 149 cpumask_set_cpu(i, mask); 150 } 151 rcu_read_unlock(); 152 153 len = min(sizeof(kbuf) - 1, *lenp); 154 len = cpumask_scnprintf(kbuf, len, mask); 155 if (!len) { 156 *lenp = 0; 157 goto done; 158 } 159 if (len < *lenp) 160 kbuf[len++] = '\n'; 161 if (copy_to_user(buffer, kbuf, len)) { 162 ret = -EFAULT; 163 goto done; 164 } 165 *lenp = len; 166 *ppos += len; 167 } 168 169 done: 170 free_cpumask_var(mask); 171 return ret; 172 } 173 174 static int flow_limit_table_len_sysctl(struct ctl_table *table, int write, 175 void __user *buffer, size_t *lenp, 176 loff_t *ppos) 177 { 178 unsigned int old, *ptr; 179 int ret; 180 181 mutex_lock(&flow_limit_update_mutex); 182 183 ptr = table->data; 184 old = *ptr; 185 ret = proc_dointvec(table, write, buffer, lenp, ppos); 186 if (!ret && write && !is_power_of_2(*ptr)) { 187 *ptr = old; 188 ret = -EINVAL; 189 } 190 191 mutex_unlock(&flow_limit_update_mutex); 192 return ret; 193 } 194 #endif /* CONFIG_NET_FLOW_LIMIT */ 195 196 static struct ctl_table net_core_table[] = { 197 #ifdef CONFIG_NET 198 { 199 .procname = "wmem_max", 200 .data = &sysctl_wmem_max, 201 .maxlen = sizeof(int), 202 .mode = 0644, 203 .proc_handler = proc_dointvec_minmax, 204 .extra1 = &one, 205 }, 206 { 207 .procname = "rmem_max", 208 .data = &sysctl_rmem_max, 209 .maxlen = sizeof(int), 210 .mode = 0644, 211 .proc_handler = proc_dointvec_minmax, 212 .extra1 = &one, 213 }, 214 { 215 .procname = "wmem_default", 216 .data = &sysctl_wmem_default, 217 .maxlen = sizeof(int), 218 .mode = 0644, 219 .proc_handler = proc_dointvec_minmax, 220 .extra1 = &one, 221 }, 222 { 223 .procname = "rmem_default", 224 .data = &sysctl_rmem_default, 225 .maxlen = sizeof(int), 226 .mode = 0644, 227 .proc_handler = proc_dointvec_minmax, 228 .extra1 = &one, 229 }, 230 { 231 .procname = "dev_weight", 232 .data = &weight_p, 233 .maxlen = sizeof(int), 234 .mode = 0644, 235 .proc_handler = proc_dointvec 236 }, 237 { 238 .procname = "netdev_max_backlog", 239 .data = &netdev_max_backlog, 240 .maxlen = sizeof(int), 241 .mode = 0644, 242 .proc_handler = proc_dointvec 243 }, 244 #ifdef CONFIG_BPF_JIT 245 { 246 .procname = "bpf_jit_enable", 247 .data = &bpf_jit_enable, 248 .maxlen = sizeof(int), 249 .mode = 0644, 250 .proc_handler = proc_dointvec 251 }, 252 #endif 253 { 254 .procname = "netdev_tstamp_prequeue", 255 .data = &netdev_tstamp_prequeue, 256 .maxlen = sizeof(int), 257 .mode = 0644, 258 .proc_handler = proc_dointvec 259 }, 260 { 261 .procname = "message_cost", 262 .data = &net_ratelimit_state.interval, 263 .maxlen = sizeof(int), 264 .mode = 0644, 265 .proc_handler = proc_dointvec_jiffies, 266 }, 267 { 268 .procname = "message_burst", 269 .data = &net_ratelimit_state.burst, 270 .maxlen = sizeof(int), 271 .mode = 0644, 272 .proc_handler = proc_dointvec, 273 }, 274 { 275 .procname = "optmem_max", 276 .data = &sysctl_optmem_max, 277 .maxlen = sizeof(int), 278 .mode = 0644, 279 .proc_handler = proc_dointvec 280 }, 281 #ifdef CONFIG_RPS 282 { 283 .procname = "rps_sock_flow_entries", 284 .maxlen = sizeof(int), 285 .mode = 0644, 286 .proc_handler = rps_sock_flow_sysctl 287 }, 288 #endif 289 #ifdef CONFIG_NET_FLOW_LIMIT 290 { 291 .procname = "flow_limit_cpu_bitmap", 292 .mode = 0644, 293 .proc_handler = flow_limit_cpu_sysctl 294 }, 295 { 296 .procname = "flow_limit_table_len", 297 .data = &netdev_flow_limit_table_len, 298 .maxlen = sizeof(int), 299 .mode = 0644, 300 .proc_handler = flow_limit_table_len_sysctl 301 }, 302 #endif /* CONFIG_NET_FLOW_LIMIT */ 303 #ifdef CONFIG_NET_RX_BUSY_POLL 304 { 305 .procname = "busy_poll", 306 .data = &sysctl_net_busy_poll, 307 .maxlen = sizeof(unsigned int), 308 .mode = 0644, 309 .proc_handler = proc_dointvec 310 }, 311 { 312 .procname = "busy_read", 313 .data = &sysctl_net_busy_read, 314 .maxlen = sizeof(unsigned int), 315 .mode = 0644, 316 .proc_handler = proc_dointvec 317 }, 318 # 319 #endif 320 #endif /* CONFIG_NET */ 321 { 322 .procname = "netdev_budget", 323 .data = &netdev_budget, 324 .maxlen = sizeof(int), 325 .mode = 0644, 326 .proc_handler = proc_dointvec 327 }, 328 { 329 .procname = "warnings", 330 .data = &net_msg_warn, 331 .maxlen = sizeof(int), 332 .mode = 0644, 333 .proc_handler = proc_dointvec 334 }, 335 { } 336 }; 337 338 static struct ctl_table netns_core_table[] = { 339 { 340 .procname = "somaxconn", 341 .data = &init_net.core.sysctl_somaxconn, 342 .maxlen = sizeof(int), 343 .mode = 0644, 344 .extra1 = &zero, 345 .extra2 = &ushort_max, 346 .proc_handler = proc_dointvec_minmax 347 }, 348 { } 349 }; 350 351 static __net_init int sysctl_core_net_init(struct net *net) 352 { 353 struct ctl_table *tbl; 354 355 net->core.sysctl_somaxconn = SOMAXCONN; 356 357 tbl = netns_core_table; 358 if (!net_eq(net, &init_net)) { 359 tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL); 360 if (tbl == NULL) 361 goto err_dup; 362 363 tbl[0].data = &net->core.sysctl_somaxconn; 364 365 /* Don't export any sysctls to unprivileged users */ 366 if (net->user_ns != &init_user_ns) { 367 tbl[0].procname = NULL; 368 } 369 } 370 371 net->core.sysctl_hdr = register_net_sysctl(net, "net/core", tbl); 372 if (net->core.sysctl_hdr == NULL) 373 goto err_reg; 374 375 return 0; 376 377 err_reg: 378 if (tbl != netns_core_table) 379 kfree(tbl); 380 err_dup: 381 return -ENOMEM; 382 } 383 384 static __net_exit void sysctl_core_net_exit(struct net *net) 385 { 386 struct ctl_table *tbl; 387 388 tbl = net->core.sysctl_hdr->ctl_table_arg; 389 unregister_net_sysctl_table(net->core.sysctl_hdr); 390 BUG_ON(tbl == netns_core_table); 391 kfree(tbl); 392 } 393 394 static __net_initdata struct pernet_operations sysctl_core_ops = { 395 .init = sysctl_core_net_init, 396 .exit = sysctl_core_net_exit, 397 }; 398 399 static __init int sysctl_core_init(void) 400 { 401 register_net_sysctl(&init_net, "net/core", net_core_table); 402 return register_pernet_subsys(&sysctl_core_ops); 403 } 404 405 fs_initcall(sysctl_core_init); 406