net/sysctl_net.c

   1 /* -*- linux-c -*-
   2  * sysctl_net.c: sysctl interface to net subsystem.
   3  *
   4  * Begun April 1, 1996, Mike Shaver.
   5  * Added /proc/sys/net directories for each protocol family. [MS]
   6  *
   7  * $Log: sysctl_net.c,v $
   8  * Revision 1.2  1996/05/08  20:24:40  shaver
   9  * Added bits for NET_BRIDGE and the NET_IPV4_ARP stuff and
  10  * NET_IPV4_IP_FORWARD.
  11  *
  12  *
  13  */
  14
  15 #include <linux/mm.h>
  16 #include <linux/sysctl.h>
  17 #include <linux/nsproxy.h>
  18
  19 #include <net/sock.h>
  20
  21 #ifdef CONFIG_INET
  22 #include <net/ip.h>
  23 #endif
  24
  25 #ifdef CONFIG_NET
  26 #include <linux/if_ether.h>
  27 #endif
  28
  29 #ifdef CONFIG_TR
  30 #include <linux/if_tr.h>
  31 #endif
  32
  33 static struct list_head *
  34 net_ctl_header_lookup(struct ctl_table_root *root, struct nsproxy *namespaces)
  35 {
  36         return &namespaces->net_ns->sysctl_table_headers;
  37 }
  38
  39 static struct ctl_table_root net_sysctl_root = {
  40         .lookup = net_ctl_header_lookup,
  41 };
  42
  43 static LIST_HEAD(net_sysctl_ro_tables);
  44 static struct list_head *net_ctl_ro_header_lookup(struct ctl_table_root *root,
  45                 struct nsproxy *namespaces)
  46 {
  47         return &net_sysctl_ro_tables;
  48 }
  49
  50 static int net_ctl_ro_header_perms(struct ctl_table_root *root,
  51                 struct nsproxy *namespaces, struct ctl_table *table)
  52 {
  53         if (namespaces->net_ns == &init_net)
  54                 return table->mode;
  55         else
  56                 return table->mode & ~0222;
  57 }
  58
  59 static struct ctl_table_root net_sysctl_ro_root = {
  60         .lookup = net_ctl_ro_header_lookup,
  61         .permissions = net_ctl_ro_header_perms,
  62 };
  63
  64 static int sysctl_net_init(struct net *net)
  65 {
  66         INIT_LIST_HEAD(&net->sysctl_table_headers);
  67         return 0;
  68 }
  69
  70 static void sysctl_net_exit(struct net *net)
  71 {
  72         WARN_ON(!list_empty(&net->sysctl_table_headers));
  73         return;
  74 }
  75
  76 static struct pernet_operations sysctl_pernet_ops = {
  77         .init = sysctl_net_init,
  78         .exit = sysctl_net_exit,
  79 };
  80
  81 static __init int sysctl_init(void)
  82 {
  83         int ret;
  84         ret = register_pernet_subsys(&sysctl_pernet_ops);
  85         if (ret)
  86                 goto out;
  87         register_sysctl_root(&net_sysctl_root);
  88         register_sysctl_root(&net_sysctl_ro_root);
  89 out:
  90         return ret;
  91 }
  92 subsys_initcall(sysctl_init);
  93
  94 struct ctl_table_header *register_net_sysctl_table(struct net *net,
  95         const struct ctl_path *path, struct ctl_table *table)
  96 {
  97         struct nsproxy namespaces;
  98         namespaces = *current->nsproxy;
  99         namespaces.net_ns = net;
 100         return __register_sysctl_paths(&net_sysctl_root,
 101                                         &namespaces, path, table);
 102 }
 103 EXPORT_SYMBOL_GPL(register_net_sysctl_table);
 104
 105 struct ctl_table_header *register_net_sysctl_rotable(const
 106                 struct ctl_path *path, struct ctl_table *table)
 107 {
 108         return __register_sysctl_paths(&net_sysctl_ro_root,
 109                         &init_nsproxy, path, table);
 110 }
 111 EXPORT_SYMBOL_GPL(register_net_sysctl_rotable);
 112
 113 void unregister_net_sysctl_table(struct ctl_table_header *header)
 114 {
 115         unregister_sysctl_table(header);
 116 }
 117 EXPORT_SYMBOL_GPL(unregister_net_sysctl_table);