projects/linux·blob v3.13 · refs

114 lines · 2.8 KiB

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
29static struct ctl_table_set *
30net_ctl_header_lookup(struct ctl_table_root *root, struct nsproxy *namespaces)
31{
32 return &namespaces->net_ns->sysctls;
33}
34
35static int is_seen(struct ctl_table_set *set)
36{
37 return &current->nsproxy->net_ns->sysctls == set;
38}
39
40/* Return standard mode bits for table entry. */
41static int net_ctl_permissions(struct ctl_table_header *head,
42 struct ctl_table *table)
43{
44 struct net *net = container_of(head->set, struct net, sysctls);
45 kuid_t root_uid = make_kuid(net->user_ns, 0);
46 kgid_t root_gid = make_kgid(net->user_ns, 0);
47
48 /* Allow network administrator to have same access as root. */
49 if (ns_capable(net->user_ns, CAP_NET_ADMIN) ||
50 uid_eq(root_uid, current_euid())) {
51 int mode = (table->mode >> 6) & 7;
52 return (mode << 6) | (mode << 3) | mode;
53 }
54 /* Allow netns root group to have the same access as the root group */
55 if (in_egroup_p(root_gid)) {
56 int mode = (table->mode >> 3) & 7;
57 return (mode << 3) | mode;
58 }
59 return table->mode;
60}
61
62static struct ctl_table_root net_sysctl_root = {
63 .lookup = net_ctl_header_lookup,
64 .permissions = net_ctl_permissions,
65};
66
67static int __net_init sysctl_net_init(struct net *net)
68{
69 setup_sysctl_set(&net->sysctls, &net_sysctl_root, is_seen);
70 return 0;
71}
72
73static void __net_exit sysctl_net_exit(struct net *net)
74{
75 retire_sysctl_set(&net->sysctls);
76}
77
78static struct pernet_operations sysctl_pernet_ops = {
79 .init = sysctl_net_init,
80 .exit = sysctl_net_exit,
81};
82
83static struct ctl_table_header *net_header;
84__init int net_sysctl_init(void)
85{
86 static struct ctl_table empty[1];
87 int ret = -ENOMEM;
88 /* Avoid limitations in the sysctl implementation by
89 * registering "/proc/sys/net" as an empty directory not in a
90 * network namespace.
91 */
92 net_header = register_sysctl("net", empty);
93 if (!net_header)
94 goto out;
95 ret = register_pernet_subsys(&sysctl_pernet_ops);
96 if (ret)
97 goto out;
98 register_sysctl_root(&net_sysctl_root);
99out:
100 return ret;
101}
102
103struct ctl_table_header *register_net_sysctl(struct net *net,
104 const char *path, struct ctl_table *table)
105{
106 return __register_sysctl_table(&net->sysctls, path, table);
107}
108EXPORT_SYMBOL_GPL(register_net_sysctl);
109
110void unregister_net_sysctl_table(struct ctl_table_header *header)
111{
112 unregister_sysctl_table(header);
113}
114EXPORT_SYMBOL_GPL(unregister_net_sysctl_table);