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 *
net_ctl_header_lookup(struct ctl_table_root * root,struct nsproxy * namespaces)33 net_ctl_header_lookup(struct ctl_table_root *root, struct nsproxy *namespaces)
34 {
35 return &namespaces->net_ns->sysctls;
36 }
37
is_seen(struct ctl_table_set * set)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. */
net_ctl_permissions(struct ctl_table_root * root,struct nsproxy * nsproxy,struct ctl_table * table)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
net_ctl_ro_header_perms(struct ctl_table_root * root,struct nsproxy * namespaces,struct ctl_table * table)61 static int net_ctl_ro_header_perms(struct ctl_table_root *root,
62 struct nsproxy *namespaces, struct ctl_table *table)
63 {
64 if (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
sysctl_net_init(struct net * net)74 static int 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
sysctl_net_exit(struct net * net)82 static void sysctl_net_exit(struct net *net)
83 {
84 WARN_ON(!list_empty(&net->sysctls.list));
85 return;
86 }
87
88 static struct pernet_operations sysctl_pernet_ops = {
89 .init = sysctl_net_init,
90 .exit = sysctl_net_exit,
91 };
92
sysctl_init(void)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
register_net_sysctl_table(struct net * net,const struct ctl_path * path,struct ctl_table * table)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
register_net_sysctl_rotable(const struct ctl_path * path,struct ctl_table * table)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
unregister_net_sysctl_table(struct ctl_table_header * header)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