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 * Revision 1.2 1996/05/08 20:24:40 shaver 8 * Added bits for NET_BRIDGE and the NET_IPV4_ARP stuff and 9 * NET_IPV4_IP_FORWARD. 10 * 11 * 12 */ 13 14 #include <linux/mm.h> 15 #include <linux/sysctl.h> 16 #include <linux/nsproxy.h> 17 18 #include <net/sock.h> 19 20 #ifdef CONFIG_INET 21 #include <net/ip.h> 22 #endif 23 24 #ifdef CONFIG_NET 25 #include <linux/if_ether.h> 26 #endif 27 28 #ifdef CONFIG_TR 29 #include <linux/if_tr.h> 30 #endif 31 32 static struct ctl_table_set * 33 net_ctl_header_lookup(struct ctl_table_root *root, struct nsproxy *namespaces) 34 { 35 return &namespaces->net_ns->sysctls; 36 } 37 38 static int is_seen(struct ctl_table_set *set) 39 { 40 return ¤t->nsproxy->net_ns->sysctls == set; 41 } 42 43 /* Return standard mode bits for table entry. */ 44 static int net_ctl_permissions(struct ctl_table_root *root, 45 struct nsproxy *nsproxy, 46 struct ctl_table *table) 47 { 48 /* Allow network administrator to have same access as root. */ 49 if (capable(CAP_NET_ADMIN)) { 50 int mode = (table->mode >> 6) & 7; 51 return (mode << 6) | (mode << 3) | mode; 52 } 53 return table->mode; 54 } 55 56 static struct ctl_table_root net_sysctl_root = { 57 .lookup = net_ctl_header_lookup, 58 .permissions = net_ctl_permissions, 59 }; 60 61 static int net_ctl_ro_header_perms(struct ctl_table_root *root, 62 struct nsproxy *namespaces, struct ctl_table *table) 63 { 64 if (net_eq(namespaces->net_ns, &init_net)) 65 return table->mode; 66 else 67 return table->mode & ~0222; 68 } 69 70 static struct ctl_table_root net_sysctl_ro_root = { 71 .permissions = net_ctl_ro_header_perms, 72 }; 73 74 static int __net_init sysctl_net_init(struct net *net) 75 { 76 setup_sysctl_set(&net->sysctls, 77 &net_sysctl_ro_root.default_set, 78 is_seen); 79 return 0; 80 } 81 82 static void __net_exit sysctl_net_exit(struct net *net) 83 { 84 WARN_ON(!list_empty(&net->sysctls.list)); 85 } 86 87 static struct pernet_operations sysctl_pernet_ops = { 88 .init = sysctl_net_init, 89 .exit = sysctl_net_exit, 90 }; 91 92 static __init int sysctl_init(void) 93 { 94 int ret; 95 ret = register_pernet_subsys(&sysctl_pernet_ops); 96 if (ret) 97 goto out; 98 register_sysctl_root(&net_sysctl_root); 99 setup_sysctl_set(&net_sysctl_ro_root.default_set, NULL, NULL); 100 register_sysctl_root(&net_sysctl_ro_root); 101 out: 102 return ret; 103 } 104 subsys_initcall(sysctl_init); 105 106 struct ctl_table_header *register_net_sysctl_table(struct net *net, 107 const struct ctl_path *path, struct ctl_table *table) 108 { 109 struct nsproxy namespaces; 110 namespaces = *current->nsproxy; 111 namespaces.net_ns = net; 112 return __register_sysctl_paths(&net_sysctl_root, 113 &namespaces, path, table); 114 } 115 EXPORT_SYMBOL_GPL(register_net_sysctl_table); 116 117 struct ctl_table_header *register_net_sysctl_rotable(const 118 struct ctl_path *path, struct ctl_table *table) 119 { 120 return __register_sysctl_paths(&net_sysctl_ro_root, 121 &init_nsproxy, path, table); 122 } 123 EXPORT_SYMBOL_GPL(register_net_sysctl_rotable); 124 125 void unregister_net_sysctl_table(struct ctl_table_header *header) 126 { 127 unregister_sysctl_table(header); 128 } 129 EXPORT_SYMBOL_GPL(unregister_net_sysctl_table); 130