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/export.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 ctl_table_set * 34 net_ctl_header_lookup(struct ctl_table_root *root, struct nsproxy *namespaces) 35 { 36 return &namespaces->net_ns->sysctls; 37 } 38 39 static int is_seen(struct ctl_table_set *set) 40 { 41 return ¤t->nsproxy->net_ns->sysctls == set; 42 } 43 44 /* Return standard mode bits for table entry. */ 45 static int net_ctl_permissions(struct ctl_table_root *root, 46 struct nsproxy *nsproxy, 47 struct ctl_table *table) 48 { 49 /* Allow network administrator to have same access as root. */ 50 if (capable(CAP_NET_ADMIN)) { 51 int mode = (table->mode >> 6) & 7; 52 return (mode << 6) | (mode << 3) | mode; 53 } 54 return table->mode; 55 } 56 57 static struct ctl_table_root net_sysctl_root = { 58 .lookup = net_ctl_header_lookup, 59 .permissions = net_ctl_permissions, 60 }; 61 62 static int net_ctl_ro_header_perms(struct ctl_table_root *root, 63 struct nsproxy *namespaces, struct ctl_table *table) 64 { 65 if (net_eq(namespaces->net_ns, &init_net)) 66 return table->mode; 67 else 68 return table->mode & ~0222; 69 } 70 71 static struct ctl_table_root net_sysctl_ro_root = { 72 .permissions = net_ctl_ro_header_perms, 73 }; 74 75 static int __net_init sysctl_net_init(struct net *net) 76 { 77 setup_sysctl_set(&net->sysctls, 78 &net_sysctl_ro_root.default_set, 79 is_seen); 80 return 0; 81 } 82 83 static void __net_exit sysctl_net_exit(struct net *net) 84 { 85 WARN_ON(!list_empty(&net->sysctls.list)); 86 } 87 88 static struct pernet_operations sysctl_pernet_ops = { 89 .init = sysctl_net_init, 90 .exit = sysctl_net_exit, 91 }; 92 93 static __init int sysctl_init(void) 94 { 95 int ret; 96 ret = register_pernet_subsys(&sysctl_pernet_ops); 97 if (ret) 98 goto out; 99 register_sysctl_root(&net_sysctl_root); 100 setup_sysctl_set(&net_sysctl_ro_root.default_set, NULL, NULL); 101 register_sysctl_root(&net_sysctl_ro_root); 102 out: 103 return ret; 104 } 105 subsys_initcall(sysctl_init); 106 107 struct ctl_table_header *register_net_sysctl_table(struct net *net, 108 const struct ctl_path *path, struct ctl_table *table) 109 { 110 struct nsproxy namespaces; 111 namespaces = *current->nsproxy; 112 namespaces.net_ns = net; 113 return __register_sysctl_paths(&net_sysctl_root, 114 &namespaces, path, table); 115 } 116 EXPORT_SYMBOL_GPL(register_net_sysctl_table); 117 118 struct ctl_table_header *register_net_sysctl_rotable(const 119 struct ctl_path *path, struct ctl_table *table) 120 { 121 return __register_sysctl_paths(&net_sysctl_ro_root, 122 &init_nsproxy, path, table); 123 } 124 EXPORT_SYMBOL_GPL(register_net_sysctl_rotable); 125 126 void unregister_net_sysctl_table(struct ctl_table_header *header) 127 { 128 unregister_sysctl_table(header); 129 } 130 EXPORT_SYMBOL_GPL(unregister_net_sysctl_table); 131