Loading...
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 ¤t->nsproxy->net_ns->sysctls == set;
38}
39
40/* Return standard mode bits for table entry. */
41static int net_ctl_permissions(struct ctl_table_root *root,
42 struct nsproxy *nsproxy,
43 struct ctl_table *table)
44{
45 /* Allow network administrator to have same access as root. */
46 if (capable(CAP_NET_ADMIN)) {
47 int mode = (table->mode >> 6) & 7;
48 return (mode << 6) | (mode << 3) | mode;
49 }
50 return table->mode;
51}
52
53static struct ctl_table_root net_sysctl_root = {
54 .lookup = net_ctl_header_lookup,
55 .permissions = net_ctl_permissions,
56};
57
58static int __net_init sysctl_net_init(struct net *net)
59{
60 setup_sysctl_set(&net->sysctls, &net_sysctl_root, is_seen);
61 return 0;
62}
63
64static void __net_exit sysctl_net_exit(struct net *net)
65{
66 retire_sysctl_set(&net->sysctls);
67}
68
69static struct pernet_operations sysctl_pernet_ops = {
70 .init = sysctl_net_init,
71 .exit = sysctl_net_exit,
72};
73
74static struct ctl_table_header *net_header;
75__init int net_sysctl_init(void)
76{
77 static struct ctl_table empty[1];
78 int ret = -ENOMEM;
79 /* Avoid limitations in the sysctl implementation by
80 * registering "/proc/sys/net" as an empty directory not in a
81 * network namespace.
82 */
83 net_header = register_sysctl("net", empty);
84 if (!net_header)
85 goto out;
86 ret = register_pernet_subsys(&sysctl_pernet_ops);
87 if (ret)
88 goto out;
89 register_sysctl_root(&net_sysctl_root);
90out:
91 return ret;
92}
93
94struct ctl_table_header *register_net_sysctl(struct net *net,
95 const char *path, struct ctl_table *table)
96{
97 return __register_sysctl_table(&net->sysctls, path, table);
98}
99EXPORT_SYMBOL_GPL(register_net_sysctl);
100
101void unregister_net_sysctl_table(struct ctl_table_header *header)
102{
103 unregister_sysctl_table(header);
104}
105EXPORT_SYMBOL_GPL(unregister_net_sysctl_table);
1// SPDX-License-Identifier: GPL-2.0-only
2/* -*- linux-c -*-
3 * sysctl_net.c: sysctl interface to net subsystem.
4 *
5 * Begun April 1, 1996, Mike Shaver.
6 * Added /proc/sys/net directories for each protocol family. [MS]
7 *
8 * Revision 1.2 1996/05/08 20:24:40 shaver
9 * Added bits for NET_BRIDGE and the NET_IPV4_ARP stuff and
10 * NET_IPV4_IP_FORWARD.
11 *
12 *
13 */
14
15#include <linux/mm.h>
16#include <linux/export.h>
17#include <linux/sysctl.h>
18#include <linux/nsproxy.h>
19
20#include <net/sock.h>
21
22#ifdef CONFIG_INET
23#include <net/ip.h>
24#endif
25
26#ifdef CONFIG_NET
27#include <linux/if_ether.h>
28#endif
29
30static struct ctl_table_set *
31net_ctl_header_lookup(struct ctl_table_root *root)
32{
33 return ¤t->nsproxy->net_ns->sysctls;
34}
35
36static int is_seen(struct ctl_table_set *set)
37{
38 return ¤t->nsproxy->net_ns->sysctls == set;
39}
40
41/* Return standard mode bits for table entry. */
42static int net_ctl_permissions(struct ctl_table_header *head,
43 struct ctl_table *table)
44{
45 struct net *net = container_of(head->set, struct net, sysctls);
46
47 /* Allow network administrator to have same access as root. */
48 if (ns_capable_noaudit(net->user_ns, CAP_NET_ADMIN)) {
49 int mode = (table->mode >> 6) & 7;
50 return (mode << 6) | (mode << 3) | mode;
51 }
52
53 return table->mode;
54}
55
56static void net_ctl_set_ownership(struct ctl_table_header *head,
57 struct ctl_table *table,
58 kuid_t *uid, kgid_t *gid)
59{
60 struct net *net = container_of(head->set, struct net, sysctls);
61 kuid_t ns_root_uid;
62 kgid_t ns_root_gid;
63
64 ns_root_uid = make_kuid(net->user_ns, 0);
65 if (uid_valid(ns_root_uid))
66 *uid = ns_root_uid;
67
68 ns_root_gid = make_kgid(net->user_ns, 0);
69 if (gid_valid(ns_root_gid))
70 *gid = ns_root_gid;
71}
72
73static struct ctl_table_root net_sysctl_root = {
74 .lookup = net_ctl_header_lookup,
75 .permissions = net_ctl_permissions,
76 .set_ownership = net_ctl_set_ownership,
77};
78
79static int __net_init sysctl_net_init(struct net *net)
80{
81 setup_sysctl_set(&net->sysctls, &net_sysctl_root, is_seen);
82 return 0;
83}
84
85static void __net_exit sysctl_net_exit(struct net *net)
86{
87 retire_sysctl_set(&net->sysctls);
88}
89
90static struct pernet_operations sysctl_pernet_ops = {
91 .init = sysctl_net_init,
92 .exit = sysctl_net_exit,
93};
94
95static struct ctl_table_header *net_header;
96__init int net_sysctl_init(void)
97{
98 static struct ctl_table empty[1];
99 int ret = -ENOMEM;
100 /* Avoid limitations in the sysctl implementation by
101 * registering "/proc/sys/net" as an empty directory not in a
102 * network namespace.
103 */
104 net_header = register_sysctl("net", empty);
105 if (!net_header)
106 goto out;
107 ret = register_pernet_subsys(&sysctl_pernet_ops);
108 if (ret)
109 goto out1;
110out:
111 return ret;
112out1:
113 unregister_sysctl_table(net_header);
114 net_header = NULL;
115 goto out;
116}
117
118struct ctl_table_header *register_net_sysctl(struct net *net,
119 const char *path, struct ctl_table *table)
120{
121 return __register_sysctl_table(&net->sysctls, path, table);
122}
123EXPORT_SYMBOL_GPL(register_net_sysctl);
124
125void unregister_net_sysctl_table(struct ctl_table_header *header)
126{
127 unregister_sysctl_table(header);
128}
129EXPORT_SYMBOL_GPL(unregister_net_sysctl_table);