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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/export.h>
13#include <linux/uts.h>
14#include <linux/utsname.h>
15#include <linux/sysctl.h>
16#include <linux/wait.h>
17
18#ifdef CONFIG_PROC_SYSCTL
19
20static void *get_uts(struct ctl_table *table, int write)
21{
22 char *which = table->data;
23 struct uts_namespace *uts_ns;
24
25 uts_ns = current->nsproxy->uts_ns;
26 which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
27
28 if (!write)
29 down_read(&uts_sem);
30 else
31 down_write(&uts_sem);
32 return which;
33}
34
35static void put_uts(struct ctl_table *table, int write, void *which)
36{
37 if (!write)
38 up_read(&uts_sem);
39 else
40 up_write(&uts_sem);
41}
42
43/*
44 * Special case of dostring for the UTS structure. This has locks
45 * to observe. Should this be in kernel/sys.c ????
46 */
47static int proc_do_uts_string(struct ctl_table *table, int write,
48 void __user *buffer, size_t *lenp, loff_t *ppos)
49{
50 struct ctl_table uts_table;
51 int r;
52 memcpy(&uts_table, table, sizeof(uts_table));
53 uts_table.data = get_uts(table, write);
54 r = proc_dostring(&uts_table, write, buffer, lenp, ppos);
55 put_uts(table, write, uts_table.data);
56
57 if (write)
58 proc_sys_poll_notify(table->poll);
59
60 return r;
61}
62#else
63#define proc_do_uts_string NULL
64#endif
65
66static DEFINE_CTL_TABLE_POLL(hostname_poll);
67static DEFINE_CTL_TABLE_POLL(domainname_poll);
68
69static struct ctl_table uts_kern_table[] = {
70 {
71 .procname = "ostype",
72 .data = init_uts_ns.name.sysname,
73 .maxlen = sizeof(init_uts_ns.name.sysname),
74 .mode = 0444,
75 .proc_handler = proc_do_uts_string,
76 },
77 {
78 .procname = "osrelease",
79 .data = init_uts_ns.name.release,
80 .maxlen = sizeof(init_uts_ns.name.release),
81 .mode = 0444,
82 .proc_handler = proc_do_uts_string,
83 },
84 {
85 .procname = "version",
86 .data = init_uts_ns.name.version,
87 .maxlen = sizeof(init_uts_ns.name.version),
88 .mode = 0444,
89 .proc_handler = proc_do_uts_string,
90 },
91 {
92 .procname = "hostname",
93 .data = init_uts_ns.name.nodename,
94 .maxlen = sizeof(init_uts_ns.name.nodename),
95 .mode = 0644,
96 .proc_handler = proc_do_uts_string,
97 .poll = &hostname_poll,
98 },
99 {
100 .procname = "domainname",
101 .data = init_uts_ns.name.domainname,
102 .maxlen = sizeof(init_uts_ns.name.domainname),
103 .mode = 0644,
104 .proc_handler = proc_do_uts_string,
105 .poll = &domainname_poll,
106 },
107 {}
108};
109
110static struct ctl_table uts_root_table[] = {
111 {
112 .procname = "kernel",
113 .mode = 0555,
114 .child = uts_kern_table,
115 },
116 {}
117};
118
119#ifdef CONFIG_PROC_SYSCTL
120/*
121 * Notify userspace about a change in a certain entry of uts_kern_table,
122 * identified by the parameter proc.
123 */
124void uts_proc_notify(enum uts_proc proc)
125{
126 struct ctl_table *table = &uts_kern_table[proc];
127
128 proc_sys_poll_notify(table->poll);
129}
130#endif
131
132static int __init utsname_sysctl_init(void)
133{
134 register_sysctl_table(uts_root_table);
135 return 0;
136}
137
138device_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#include <linux/rwsem.h>
18
19#ifdef CONFIG_PROC_SYSCTL
20
21static void *get_uts(struct ctl_table *table, int write)
22{
23 char *which = table->data;
24 struct uts_namespace *uts_ns;
25
26 uts_ns = current->nsproxy->uts_ns;
27 which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
28
29 if (!write)
30 down_read(&uts_sem);
31 else
32 down_write(&uts_sem);
33 return which;
34}
35
36static void put_uts(struct ctl_table *table, int write, void *which)
37{
38 if (!write)
39 up_read(&uts_sem);
40 else
41 up_write(&uts_sem);
42}
43
44/*
45 * Special case of dostring for the UTS structure. This has locks
46 * to observe. Should this be in kernel/sys.c ????
47 */
48static int proc_do_uts_string(struct ctl_table *table, int write,
49 void __user *buffer, size_t *lenp, loff_t *ppos)
50{
51 struct ctl_table uts_table;
52 int r;
53 memcpy(&uts_table, table, sizeof(uts_table));
54 uts_table.data = get_uts(table, write);
55 r = proc_dostring(&uts_table, write, buffer, lenp, ppos);
56 put_uts(table, write, uts_table.data);
57
58 if (write)
59 proc_sys_poll_notify(table->poll);
60
61 return r;
62}
63#else
64#define proc_do_uts_string NULL
65#endif
66
67static DEFINE_CTL_TABLE_POLL(hostname_poll);
68static DEFINE_CTL_TABLE_POLL(domainname_poll);
69
70static struct ctl_table uts_kern_table[] = {
71 {
72 .procname = "ostype",
73 .data = init_uts_ns.name.sysname,
74 .maxlen = sizeof(init_uts_ns.name.sysname),
75 .mode = 0444,
76 .proc_handler = proc_do_uts_string,
77 },
78 {
79 .procname = "osrelease",
80 .data = init_uts_ns.name.release,
81 .maxlen = sizeof(init_uts_ns.name.release),
82 .mode = 0444,
83 .proc_handler = proc_do_uts_string,
84 },
85 {
86 .procname = "version",
87 .data = init_uts_ns.name.version,
88 .maxlen = sizeof(init_uts_ns.name.version),
89 .mode = 0444,
90 .proc_handler = proc_do_uts_string,
91 },
92 {
93 .procname = "hostname",
94 .data = init_uts_ns.name.nodename,
95 .maxlen = sizeof(init_uts_ns.name.nodename),
96 .mode = 0644,
97 .proc_handler = proc_do_uts_string,
98 .poll = &hostname_poll,
99 },
100 {
101 .procname = "domainname",
102 .data = init_uts_ns.name.domainname,
103 .maxlen = sizeof(init_uts_ns.name.domainname),
104 .mode = 0644,
105 .proc_handler = proc_do_uts_string,
106 .poll = &domainname_poll,
107 },
108 {}
109};
110
111static struct ctl_table uts_root_table[] = {
112 {
113 .procname = "kernel",
114 .mode = 0555,
115 .child = uts_kern_table,
116 },
117 {}
118};
119
120#ifdef CONFIG_PROC_SYSCTL
121/*
122 * Notify userspace about a change in a certain entry of uts_kern_table,
123 * identified by the parameter proc.
124 */
125void uts_proc_notify(enum uts_proc proc)
126{
127 struct ctl_table *table = &uts_kern_table[proc];
128
129 proc_sys_poll_notify(table->poll);
130}
131#endif
132
133static int __init utsname_sysctl_init(void)
134{
135 register_sysctl_table(uts_root_table);
136 return 0;
137}
138
139device_initcall(utsname_sysctl_init);