Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Linux/kernel/utsname_sysctl.c

  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 
 20 static 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 
 35 static 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  */
 47 static 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 
 66 static DEFINE_CTL_TABLE_POLL(hostname_poll);
 67 static DEFINE_CTL_TABLE_POLL(domainname_poll);
 68 
 69 static 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 
110 static 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  */
124 void 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 
132 static int __init utsname_sysctl_init(void)
133 {
134         register_sysctl_table(uts_root_table);
135         return 0;
136 }
137 
138 device_initcall(utsname_sysctl_init);
139 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us