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)
31{
32 return &current->nsproxy->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
46 /* Allow network administrator to have same access as root. */
47 if (ns_capable_noaudit(net->user_ns, CAP_NET_ADMIN)) {
48 int mode = (table->mode >> 6) & 7;
49 return (mode << 6) | (mode << 3) | mode;
50 }
51
52 return table->mode;
53}
54
55static void net_ctl_set_ownership(struct ctl_table_header *head,
56 struct ctl_table *table,
57 kuid_t *uid, kgid_t *gid)
58{
59 struct net *net = container_of(head->set, struct net, sysctls);
60 kuid_t ns_root_uid;
61 kgid_t ns_root_gid;
62
63 ns_root_uid = make_kuid(net->user_ns, 0);
64 if (uid_valid(ns_root_uid))
65 *uid = ns_root_uid;
66
67 ns_root_gid = make_kgid(net->user_ns, 0);
68 if (gid_valid(ns_root_gid))
69 *gid = ns_root_gid;
70}
71
72static struct ctl_table_root net_sysctl_root = {
73 .lookup = net_ctl_header_lookup,
74 .permissions = net_ctl_permissions,
75 .set_ownership = net_ctl_set_ownership,
76};
77
78static int __net_init sysctl_net_init(struct net *net)
79{
80 setup_sysctl_set(&net->sysctls, &net_sysctl_root, is_seen);
81 return 0;
82}
83
84static void __net_exit sysctl_net_exit(struct net *net)
85{
86 retire_sysctl_set(&net->sysctls);
87}
88
89static struct pernet_operations sysctl_pernet_ops = {
90 .init = sysctl_net_init,
91 .exit = sysctl_net_exit,
92};
93
94static struct ctl_table_header *net_header;
95__init int net_sysctl_init(void)
96{
97 static struct ctl_table empty[1];
98 int ret = -ENOMEM;
99 /* Avoid limitations in the sysctl implementation by
100 * registering "/proc/sys/net" as an empty directory not in a
101 * network namespace.
102 */
103 net_header = register_sysctl("net", empty);
104 if (!net_header)
105 goto out;
106 ret = register_pernet_subsys(&sysctl_pernet_ops);
107 if (ret)
108 goto out1;
109out:
110 return ret;
111out1:
112 unregister_sysctl_table(net_header);
113 net_header = NULL;
114 goto out;
115}
116
117struct ctl_table_header *register_net_sysctl(struct net *net,
118 const char *path, struct ctl_table *table)
119{
120 return __register_sysctl_table(&net->sysctls, path, table);
121}
122EXPORT_SYMBOL_GPL(register_net_sysctl);
123
124void unregister_net_sysctl_table(struct ctl_table_header *header)
125{
126 unregister_sysctl_table(header);
127}
128EXPORT_SYMBOL_GPL(unregister_net_sysctl_table);
129