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1/*
2 * Copyright (C) 2007
3 *
4 * Author: Eric Biederman <ebiederm@xmision.com>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation, version 2 of the
9 * License.
10 */
11
12#include <linux/module.h>
13#include <linux/uts.h>
14#include <linux/utsname.h>
15#include <linux/sysctl.h>
16
17static void *get_uts(ctl_table *table, int write)
18{
19 char *which = table->data;
20 struct uts_namespace *uts_ns;
21
22 uts_ns = current->nsproxy->uts_ns;
23 which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
24
25 if (!write)
26 down_read(&uts_sem);
27 else
28 down_write(&uts_sem);
29 return which;
30}
31
32static void put_uts(ctl_table *table, int write, void *which)
33{
34 if (!write)
35 up_read(&uts_sem);
36 else
37 up_write(&uts_sem);
38}
39
40#ifdef CONFIG_PROC_SYSCTL
41/*
42 * Special case of dostring for the UTS structure. This has locks
43 * to observe. Should this be in kernel/sys.c ????
44 */
45static int proc_do_uts_string(ctl_table *table, int write,
46 void __user *buffer, size_t *lenp, loff_t *ppos)
47{
48 struct ctl_table uts_table;
49 int r;
50 memcpy(&uts_table, table, sizeof(uts_table));
51 uts_table.data = get_uts(table, write);
52 r = proc_dostring(&uts_table,write,buffer,lenp, ppos);
53 put_uts(table, write, uts_table.data);
54 return r;
55}
56#else
57#define proc_do_uts_string NULL
58#endif
59
60static struct ctl_table uts_kern_table[] = {
61 {
62 .procname = "ostype",
63 .data = init_uts_ns.name.sysname,
64 .maxlen = sizeof(init_uts_ns.name.sysname),
65 .mode = 0444,
66 .proc_handler = proc_do_uts_string,
67 },
68 {
69 .procname = "osrelease",
70 .data = init_uts_ns.name.release,
71 .maxlen = sizeof(init_uts_ns.name.release),
72 .mode = 0444,
73 .proc_handler = proc_do_uts_string,
74 },
75 {
76 .procname = "version",
77 .data = init_uts_ns.name.version,
78 .maxlen = sizeof(init_uts_ns.name.version),
79 .mode = 0444,
80 .proc_handler = proc_do_uts_string,
81 },
82 {
83 .procname = "hostname",
84 .data = init_uts_ns.name.nodename,
85 .maxlen = sizeof(init_uts_ns.name.nodename),
86 .mode = 0644,
87 .proc_handler = proc_do_uts_string,
88 },
89 {
90 .procname = "domainname",
91 .data = init_uts_ns.name.domainname,
92 .maxlen = sizeof(init_uts_ns.name.domainname),
93 .mode = 0644,
94 .proc_handler = proc_do_uts_string,
95 },
96 {}
97};
98
99static struct ctl_table uts_root_table[] = {
100 {
101 .procname = "kernel",
102 .mode = 0555,
103 .child = uts_kern_table,
104 },
105 {}
106};
107
108static int __init utsname_sysctl_init(void)
109{
110 register_sysctl_table(uts_root_table);
111 return 0;
112}
113
114__initcall(utsname_sysctl_init);
1/*
2 * Copyright (C) 2007
3 *
4 * Author: Eric Biederman <ebiederm@xmision.com>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation, version 2 of the
9 * License.
10 */
11
12#include <linux/export.h>
13#include <linux/uts.h>
14#include <linux/utsname.h>
15#include <linux/sysctl.h>
16#include <linux/wait.h>
17
18static void *get_uts(ctl_table *table, int write)
19{
20 char *which = table->data;
21 struct uts_namespace *uts_ns;
22
23 uts_ns = current->nsproxy->uts_ns;
24 which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
25
26 if (!write)
27 down_read(&uts_sem);
28 else
29 down_write(&uts_sem);
30 return which;
31}
32
33static void put_uts(ctl_table *table, int write, void *which)
34{
35 if (!write)
36 up_read(&uts_sem);
37 else
38 up_write(&uts_sem);
39}
40
41#ifdef CONFIG_PROC_SYSCTL
42/*
43 * Special case of dostring for the UTS structure. This has locks
44 * to observe. Should this be in kernel/sys.c ????
45 */
46static int proc_do_uts_string(ctl_table *table, int write,
47 void __user *buffer, size_t *lenp, loff_t *ppos)
48{
49 struct ctl_table uts_table;
50 int r;
51 memcpy(&uts_table, table, sizeof(uts_table));
52 uts_table.data = get_uts(table, write);
53 r = proc_dostring(&uts_table,write,buffer,lenp, ppos);
54 put_uts(table, write, uts_table.data);
55
56 if (write)
57 proc_sys_poll_notify(table->poll);
58
59 return r;
60}
61#else
62#define proc_do_uts_string NULL
63#endif
64
65static DEFINE_CTL_TABLE_POLL(hostname_poll);
66static DEFINE_CTL_TABLE_POLL(domainname_poll);
67
68static struct ctl_table uts_kern_table[] = {
69 {
70 .procname = "ostype",
71 .data = init_uts_ns.name.sysname,
72 .maxlen = sizeof(init_uts_ns.name.sysname),
73 .mode = 0444,
74 .proc_handler = proc_do_uts_string,
75 },
76 {
77 .procname = "osrelease",
78 .data = init_uts_ns.name.release,
79 .maxlen = sizeof(init_uts_ns.name.release),
80 .mode = 0444,
81 .proc_handler = proc_do_uts_string,
82 },
83 {
84 .procname = "version",
85 .data = init_uts_ns.name.version,
86 .maxlen = sizeof(init_uts_ns.name.version),
87 .mode = 0444,
88 .proc_handler = proc_do_uts_string,
89 },
90 {
91 .procname = "hostname",
92 .data = init_uts_ns.name.nodename,
93 .maxlen = sizeof(init_uts_ns.name.nodename),
94 .mode = 0644,
95 .proc_handler = proc_do_uts_string,
96 .poll = &hostname_poll,
97 },
98 {
99 .procname = "domainname",
100 .data = init_uts_ns.name.domainname,
101 .maxlen = sizeof(init_uts_ns.name.domainname),
102 .mode = 0644,
103 .proc_handler = proc_do_uts_string,
104 .poll = &domainname_poll,
105 },
106 {}
107};
108
109static struct ctl_table uts_root_table[] = {
110 {
111 .procname = "kernel",
112 .mode = 0555,
113 .child = uts_kern_table,
114 },
115 {}
116};
117
118#ifdef CONFIG_PROC_SYSCTL
119/*
120 * Notify userspace about a change in a certain entry of uts_kern_table,
121 * identified by the parameter proc.
122 */
123void uts_proc_notify(enum uts_proc proc)
124{
125 struct ctl_table *table = &uts_kern_table[proc];
126
127 proc_sys_poll_notify(table->poll);
128}
129#endif
130
131static int __init utsname_sysctl_init(void)
132{
133 register_sysctl_table(uts_root_table);
134 return 0;
135}
136
137__initcall(utsname_sysctl_init);