nl80211: Check that function pointer != NULL before using it
[linux-2.6-block.git] / net / sysctl_net.c
CommitLineData
1da177e4
LT
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 *
1da177e4
LT
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
1da177e4
LT
14#include <linux/mm.h>
15#include <linux/sysctl.h>
95bdfccb 16#include <linux/nsproxy.h>
1da177e4 17
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RK
18#include <net/sock.h>
19
1da177e4 20#ifdef CONFIG_INET
20380731 21#include <net/ip.h>
1da177e4
LT
22#endif
23
1da177e4 24#ifdef CONFIG_NET
20380731 25#include <linux/if_ether.h>
1da177e4
LT
26#endif
27
28#ifdef CONFIG_TR
20380731 29#include <linux/if_tr.h>
1da177e4
LT
30#endif
31
73455092 32static struct ctl_table_set *
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33net_ctl_header_lookup(struct ctl_table_root *root, struct nsproxy *namespaces)
34{
73455092
AV
35 return &namespaces->net_ns->sysctls;
36}
37
38static int is_seen(struct ctl_table_set *set)
39{
40 return &current->nsproxy->net_ns->sysctls == set;
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EB
41}
42
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SH
43/* Return standard mode bits for table entry. */
44static 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
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56static struct ctl_table_root net_sysctl_root = {
57 .lookup = net_ctl_header_lookup,
4ecb9009 58 .permissions = net_ctl_permissions,
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59};
60
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PE
61static 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
70static struct ctl_table_root net_sysctl_ro_root = {
d62c612e
PE
71 .permissions = net_ctl_ro_header_perms,
72};
73
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EB
74static int sysctl_net_init(struct net *net)
75{
eeb61f71
AV
76 setup_sysctl_set(&net->sysctls,
77 &net_sysctl_ro_root.default_set,
78 is_seen);
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EB
79 return 0;
80}
81
82static void sysctl_net_exit(struct net *net)
83{
73455092 84 WARN_ON(!list_empty(&net->sysctls.list));
95bdfccb
EB
85 return;
86}
87
88static struct pernet_operations sysctl_pernet_ops = {
89 .init = sysctl_net_init,
90 .exit = sysctl_net_exit,
91};
92
93static __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);
73455092 100 setup_sysctl_set(&net_sysctl_ro_root.default_set, NULL, NULL);
d62c612e 101 register_sysctl_root(&net_sysctl_ro_root);
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102out:
103 return ret;
104}
105subsys_initcall(sysctl_init);
106
107struct 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}
116EXPORT_SYMBOL_GPL(register_net_sysctl_table);
117
d62c612e
PE
118struct 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}
124EXPORT_SYMBOL_GPL(register_net_sysctl_rotable);
125
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126void unregister_net_sysctl_table(struct ctl_table_header *header)
127{
ab59859d 128 unregister_sysctl_table(header);
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129}
130EXPORT_SYMBOL_GPL(unregister_net_sysctl_table);