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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* -*- 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 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/mm.h>
Paul Gortmakerbc3b2d72011-07-15 11:47:34 -040015#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/sysctl.h>
Eric W. Biederman95bdfcc2007-11-30 23:55:42 +110017#include <linux/nsproxy.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018
Russell King496a22b2005-10-03 14:16:34 -070019#include <net/sock.h>
20
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#ifdef CONFIG_INET
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -030022#include <net/ip.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#endif
24
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#ifdef CONFIG_NET
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -030026#include <linux/if_ether.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#endif
28
Al Viro73455092008-07-14 21:22:20 -040029static struct ctl_table_set *
Eric W. Biederman95bdfcc2007-11-30 23:55:42 +110030net_ctl_header_lookup(struct ctl_table_root *root, struct nsproxy *namespaces)
31{
Al Viro73455092008-07-14 21:22:20 -040032 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;
Eric W. Biederman95bdfcc2007-11-30 23:55:42 +110038}
39
Stephen Hemminger4ecb9002008-07-25 01:48:32 -070040/* Return standard mode bits for table entry. */
Eric W. Biederman73f7ef42012-11-16 03:02:58 +000041static int net_ctl_permissions(struct ctl_table_header *head,
Stephen Hemminger4ecb9002008-07-25 01:48:32 -070042 struct ctl_table *table)
43{
Eric W. Biedermancff10972012-11-16 03:03:01 +000044 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
Stephen Hemminger4ecb9002008-07-25 01:48:32 -070048 /* Allow network administrator to have same access as root. */
Tyler Hicksd6e0d302016-06-02 23:43:22 -050049 if (ns_capable_noaudit(net->user_ns, CAP_NET_ADMIN) ||
Eric W. Biederman2433c8f2013-10-05 13:15:30 -070050 uid_eq(root_uid, current_euid())) {
Stephen Hemminger4ecb9002008-07-25 01:48:32 -070051 int mode = (table->mode >> 6) & 7;
52 return (mode << 6) | (mode << 3) | mode;
53 }
Zhao Hongjiang86937c02012-11-16 03:03:02 +000054 /* Allow netns root group to have the same access as the root group */
Eric W. Biederman2433c8f2013-10-05 13:15:30 -070055 if (in_egroup_p(root_gid)) {
Eric W. Biedermancff10972012-11-16 03:03:01 +000056 int mode = (table->mode >> 3) & 7;
Zhao Hongjiang86937c02012-11-16 03:03:02 +000057 return (mode << 3) | mode;
Eric W. Biedermancff10972012-11-16 03:03:01 +000058 }
Stephen Hemminger4ecb9002008-07-25 01:48:32 -070059 return table->mode;
60}
61
Eric W. Biederman95bdfcc2007-11-30 23:55:42 +110062static struct ctl_table_root net_sysctl_root = {
63 .lookup = net_ctl_header_lookup,
Stephen Hemminger4ecb9002008-07-25 01:48:32 -070064 .permissions = net_ctl_permissions,
Eric W. Biederman95bdfcc2007-11-30 23:55:42 +110065};
66
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +000067static int __net_init sysctl_net_init(struct net *net)
Eric W. Biederman95bdfcc2007-11-30 23:55:42 +110068{
Eric W. Biederman9eb47c22012-01-22 21:26:00 -080069 setup_sysctl_set(&net->sysctls, &net_sysctl_root, is_seen);
Eric W. Biederman95bdfcc2007-11-30 23:55:42 +110070 return 0;
71}
72
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +000073static void __net_exit sysctl_net_exit(struct net *net)
Eric W. Biederman95bdfcc2007-11-30 23:55:42 +110074{
Eric W. Biederman97324cd82012-01-09 22:19:13 -080075 retire_sysctl_set(&net->sysctls);
Eric W. Biederman95bdfcc2007-11-30 23:55:42 +110076}
77
78static struct pernet_operations sysctl_pernet_ops = {
79 .init = sysctl_net_init,
80 .exit = sysctl_net_exit,
81};
82
Eric W. Biedermanbc8a3692012-04-19 13:19:46 +000083static struct ctl_table_header *net_header;
Eric W. Biederman2ca794e2012-04-19 13:20:32 +000084__init int net_sysctl_init(void)
Eric W. Biederman95bdfcc2007-11-30 23:55:42 +110085{
Eric W. Biedermanbc8a3692012-04-19 13:19:46 +000086 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;
Eric W. Biederman95bdfcc2007-11-30 23:55:42 +110095 ret = register_pernet_subsys(&sysctl_pernet_ops);
96 if (ret)
Li RongQingce9d9b82015-10-23 20:59:49 +080097 goto out1;
Eric W. Biedermanbd295b52012-01-22 21:10:21 -080098 register_sysctl_root(&net_sysctl_root);
Eric W. Biederman95bdfcc2007-11-30 23:55:42 +110099out:
100 return ret;
Li RongQingce9d9b82015-10-23 20:59:49 +0800101out1:
102 unregister_sysctl_table(net_header);
103 net_header = NULL;
104 goto out;
Eric W. Biederman95bdfcc2007-11-30 23:55:42 +1100105}
Eric W. Biederman95bdfcc2007-11-30 23:55:42 +1100106
Eric W. Biedermanab41a2c2012-04-19 13:18:47 +0000107struct ctl_table_header *register_net_sysctl(struct net *net,
108 const char *path, struct ctl_table *table)
109{
110 return __register_sysctl_table(&net->sysctls, path, table);
111}
112EXPORT_SYMBOL_GPL(register_net_sysctl);
113
Eric W. Biederman95bdfcc2007-11-30 23:55:42 +1100114void unregister_net_sysctl_table(struct ctl_table_header *header)
115{
Harvey Harrisonab598592008-05-01 02:47:38 -0700116 unregister_sysctl_table(header);
Eric W. Biederman95bdfcc2007-11-30 23:55:42 +1100117}
118EXPORT_SYMBOL_GPL(unregister_net_sysctl_table);