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-rw-r--r--kernel/utsname_sysctl.c146
1 files changed, 146 insertions, 0 deletions
diff --git a/kernel/utsname_sysctl.c b/kernel/utsname_sysctl.c
new file mode 100644
index 000000000000..f22b9dbd2a9c
--- /dev/null
+++ b/kernel/utsname_sysctl.c
@@ -0,0 +1,146 @@
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/version.h>
16#include <linux/sysctl.h>
17
18static void *get_uts(ctl_table *table, int write)
19{
20 char *which = table->data;
21#ifdef CONFIG_UTS_NS
22 struct uts_namespace *uts_ns = current->nsproxy->uts_ns;
23 which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
24#endif
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_FS
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, struct file *filp,
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,filp,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
60
61#ifdef CONFIG_SYSCTL_SYSCALL
62/* The generic string strategy routine: */
63static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen,
64 void __user *oldval, size_t __user *oldlenp,
65 void __user *newval, size_t newlen)
66{
67 struct ctl_table uts_table;
68 int r, write;
69 write = newval && newlen;
70 memcpy(&uts_table, table, sizeof(uts_table));
71 uts_table.data = get_uts(table, write);
72 r = sysctl_string(&uts_table, name, nlen,
73 oldval, oldlenp, newval, newlen);
74 put_uts(table, write, uts_table.data);
75 return r;
76}
77#else
78#define sysctl_uts_string NULL
79#endif
80
81static struct ctl_table uts_kern_table[] = {
82 {
83 .ctl_name = KERN_OSTYPE,
84 .procname = "ostype",
85 .data = init_uts_ns.name.sysname,
86 .maxlen = sizeof(init_uts_ns.name.sysname),
87 .mode = 0444,
88 .proc_handler = proc_do_uts_string,
89 .strategy = sysctl_uts_string,
90 },
91 {
92 .ctl_name = KERN_OSRELEASE,
93 .procname = "osrelease",
94 .data = init_uts_ns.name.release,
95 .maxlen = sizeof(init_uts_ns.name.release),
96 .mode = 0444,
97 .proc_handler = proc_do_uts_string,
98 .strategy = sysctl_uts_string,
99 },
100 {
101 .ctl_name = KERN_VERSION,
102 .procname = "version",
103 .data = init_uts_ns.name.version,
104 .maxlen = sizeof(init_uts_ns.name.version),
105 .mode = 0444,
106 .proc_handler = proc_do_uts_string,
107 .strategy = sysctl_uts_string,
108 },
109 {
110 .ctl_name = KERN_NODENAME,
111 .procname = "hostname",
112 .data = init_uts_ns.name.nodename,
113 .maxlen = sizeof(init_uts_ns.name.nodename),
114 .mode = 0644,
115 .proc_handler = proc_do_uts_string,
116 .strategy = sysctl_uts_string,
117 },
118 {
119 .ctl_name = KERN_DOMAINNAME,
120 .procname = "domainname",
121 .data = init_uts_ns.name.domainname,
122 .maxlen = sizeof(init_uts_ns.name.domainname),
123 .mode = 0644,
124 .proc_handler = proc_do_uts_string,
125 .strategy = sysctl_uts_string,
126 },
127 {}
128};
129
130static struct ctl_table uts_root_table[] = {
131 {
132 .ctl_name = CTL_KERN,
133 .procname = "kernel",
134 .mode = 0555,
135 .child = uts_kern_table,
136 },
137 {}
138};
139
140static int __init utsname_sysctl_init(void)
141{
142 register_sysctl_table(uts_root_table);
143 return 0;
144}
145
146__initcall(utsname_sysctl_init);