net/core/sysctl_net_core.c

   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
  18 #include <net/ip.h>
  19 #include <net/sock.h>
  20
  21 #ifdef CONFIG_RPS
  22 static int rps_sock_flow_sysctl(ctl_table *table, int write,
  23                                 void __user *buffer, size_t *lenp, loff_t *ppos)
  24 {
  25         unsigned int orig_size, size;
  26         int ret, i;
  27         ctl_table tmp = {
  28                 .data = &size,
  29                 .maxlen = sizeof(size),
  30                 .mode = table->mode
  31         };
  32         struct rps_sock_flow_table *orig_sock_table, *sock_table;
  33         static DEFINE_MUTEX(sock_flow_mutex);
  34
  35         mutex_lock(&sock_flow_mutex);
  36
  37         orig_sock_table = rcu_dereference_protected(rps_sock_flow_table,
  38                                         lockdep_is_held(&sock_flow_mutex));
  39         size = orig_size = orig_sock_table ? orig_sock_table->mask + 1 : 0;
  40
  41         ret = proc_dointvec(&tmp, write, buffer, lenp, ppos);
  42
  43         if (write) {
  44                 if (size) {
  45                         if (size > 1<<30) {
  46                                 /* Enforce limit to prevent overflow */
  47                                 mutex_unlock(&sock_flow_mutex);
  48                                 return -EINVAL;
  49                         }
  50                         size = roundup_pow_of_two(size);
  51                         if (size != orig_size) {
  52                                 sock_table =
  53                                     vmalloc(RPS_SOCK_FLOW_TABLE_SIZE(size));
  54                                 if (!sock_table) {
  55                                         mutex_unlock(&sock_flow_mutex);
  56                                         return -ENOMEM;
  57                                 }
  58
  59                                 sock_table->mask = size - 1;
  60                         } else
  61                                 sock_table = orig_sock_table;
  62
  63                         for (i = 0; i < size; i++)
  64                                 sock_table->ents[i] = RPS_NO_CPU;
  65                 } else
  66                         sock_table = NULL;
  67
  68                 if (sock_table != orig_sock_table) {
  69                         rcu_assign_pointer(rps_sock_flow_table, sock_table);
  70                         synchronize_rcu();
  71                         vfree(orig_sock_table);
  72                 }
  73         }
  74
  75         mutex_unlock(&sock_flow_mutex);
  76
  77         return ret;
  78 }
  79 #endif /* CONFIG_RPS */
  80
  81 static struct ctl_table net_core_table[] = {
  82 #ifdef CONFIG_NET
  83         {
  84                 .procname       = "wmem_max",
  85                 .data           = &sysctl_wmem_max,
  86                 .maxlen         = sizeof(int),
  87                 .mode           = 0644,
  88                 .proc_handler   = proc_dointvec
  89         },
  90         {
  91                 .procname       = "rmem_max",
  92                 .data           = &sysctl_rmem_max,
  93                 .maxlen         = sizeof(int),
  94                 .mode           = 0644,
  95                 .proc_handler   = proc_dointvec
  96         },
  97         {
  98                 .procname       = "wmem_default",
  99                 .data           = &sysctl_wmem_default,
 100                 .maxlen         = sizeof(int),
 101                 .mode           = 0644,
 102                 .proc_handler   = proc_dointvec
 103         },
 104         {
 105                 .procname       = "rmem_default",
 106                 .data           = &sysctl_rmem_default,
 107                 .maxlen         = sizeof(int),
 108                 .mode           = 0644,
 109                 .proc_handler   = proc_dointvec
 110         },
 111         {
 112                 .procname       = "dev_weight",
 113                 .data           = &weight_p,
 114                 .maxlen         = sizeof(int),
 115                 .mode           = 0644,
 116                 .proc_handler   = proc_dointvec
 117         },
 118         {
 119                 .procname       = "netdev_max_backlog",
 120                 .data           = &netdev_max_backlog,
 121                 .maxlen         = sizeof(int),
 122                 .mode           = 0644,
 123                 .proc_handler   = proc_dointvec
 124         },
 125         {
 126                 .procname       = "netdev_tstamp_prequeue",
 127                 .data           = &netdev_tstamp_prequeue,
 128                 .maxlen         = sizeof(int),
 129                 .mode           = 0644,
 130                 .proc_handler   = proc_dointvec
 131         },
 132         {
 133                 .procname       = "message_cost",
 134                 .data           = &net_ratelimit_state.interval,
 135                 .maxlen         = sizeof(int),
 136                 .mode           = 0644,
 137                 .proc_handler   = proc_dointvec_jiffies,
 138         },
 139         {
 140                 .procname       = "message_burst",
 141                 .data           = &net_ratelimit_state.burst,
 142                 .maxlen         = sizeof(int),
 143                 .mode           = 0644,
 144                 .proc_handler   = proc_dointvec,
 145         },
 146         {
 147                 .procname       = "optmem_max",
 148                 .data           = &sysctl_optmem_max,
 149                 .maxlen         = sizeof(int),
 150                 .mode           = 0644,
 151                 .proc_handler   = proc_dointvec
 152         },
 153 #ifdef CONFIG_RPS
 154         {
 155                 .procname       = "rps_sock_flow_entries",
 156                 .maxlen         = sizeof(int),
 157                 .mode           = 0644,
 158                 .proc_handler   = rps_sock_flow_sysctl
 159         },
 160 #endif
 161 #endif /* CONFIG_NET */
 162         {
 163                 .procname       = "netdev_budget",
 164                 .data           = &netdev_budget,
 165                 .maxlen         = sizeof(int),
 166                 .mode           = 0644,
 167                 .proc_handler   = proc_dointvec
 168         },
 169         {
 170                 .procname       = "warnings",
 171                 .data           = &net_msg_warn,
 172                 .maxlen         = sizeof(int),
 173                 .mode           = 0644,
 174                 .proc_handler   = proc_dointvec
 175         },
 176         { }
 177 };
 178
 179 static struct ctl_table netns_core_table[] = {
 180         {
 181                 .procname       = "somaxconn",
 182                 .data           = &init_net.core.sysctl_somaxconn,
 183                 .maxlen         = sizeof(int),
 184                 .mode           = 0644,
 185                 .proc_handler   = proc_dointvec
 186         },
 187         { }
 188 };
 189
 190 __net_initdata struct ctl_path net_core_path[] = {
 191         { .procname = "net", },
 192         { .procname = "core", },
 193         { },
 194 };
 195
 196 static __net_init int sysctl_core_net_init(struct net *net)
 197 {
 198         struct ctl_table *tbl;
 199
 200         net->core.sysctl_somaxconn = SOMAXCONN;
 201
 202         tbl = netns_core_table;
 203         if (!net_eq(net, &init_net)) {
 204                 tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL);
 205                 if (tbl == NULL)
 206                         goto err_dup;
 207
 208                 tbl[0].data = &net->core.sysctl_somaxconn;
 209         }
 210
 211         net->core.sysctl_hdr = register_net_sysctl_table(net,
 212                         net_core_path, tbl);
 213         if (net->core.sysctl_hdr == NULL)
 214                 goto err_reg;
 215
 216         return 0;
 217
 218 err_reg:
 219         if (tbl != netns_core_table)
 220                 kfree(tbl);
 221 err_dup:
 222         return -ENOMEM;
 223 }
 224
 225 static __net_exit void sysctl_core_net_exit(struct net *net)
 226 {
 227         struct ctl_table *tbl;
 228
 229         tbl = net->core.sysctl_hdr->ctl_table_arg;
 230         unregister_net_sysctl_table(net->core.sysctl_hdr);
 231         BUG_ON(tbl == netns_core_table);
 232         kfree(tbl);
 233 }
 234
 235 static __net_initdata struct pernet_operations sysctl_core_ops = {
 236         .init = sysctl_core_net_init,
 237         .exit = sysctl_core_net_exit,
 238 };
 239
 240 static __init int sysctl_core_init(void)
 241 {
 242         static struct ctl_table empty[1];
 243
 244         register_sysctl_paths(net_core_path, empty);
 245         register_net_sysctl_rotable(net_core_path, net_core_table);
 246         return register_pernet_subsys(&sysctl_core_ops);
 247 }
 248
 249 fs_initcall(sysctl_core_init);