Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 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 | |
Paul Gortmaker | 9984de1 | 2011-05-23 14:51:41 -0400 | [diff] [blame] | 12 | #include <linux/export.h> |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 13 | #include <linux/uts.h> |
| 14 | #include <linux/utsname.h> |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 15 | #include <linux/sysctl.h> |
Lucas De Marchi | f1ecf06 | 2011-11-02 13:39:22 -0700 | [diff] [blame] | 16 | #include <linux/wait.h> |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 17 | |
| 18 | static void *get_uts(ctl_table *table, int write) |
| 19 | { |
| 20 | char *which = table->data; |
Pavel Emelyanov | 32df81c | 2007-11-28 16:21:38 -0800 | [diff] [blame] | 21 | struct uts_namespace *uts_ns; |
| 22 | |
| 23 | uts_ns = current->nsproxy->uts_ns; |
| 24 | which = (which - (char *)&init_uts_ns) + (char *)uts_ns; |
Cedric Le Goater | 7d69a1f | 2007-07-15 23:40:58 -0700 | [diff] [blame] | 25 | |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 26 | if (!write) |
| 27 | down_read(&uts_sem); |
| 28 | else |
| 29 | down_write(&uts_sem); |
| 30 | return which; |
| 31 | } |
| 32 | |
| 33 | static 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 | |
Serge E. Hallyn | 11dea19 | 2009-04-02 16:58:27 -0700 | [diff] [blame] | 41 | #ifdef CONFIG_PROC_SYSCTL |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 42 | /* |
| 43 | * Special case of dostring for the UTS structure. This has locks |
| 44 | * to observe. Should this be in kernel/sys.c ???? |
| 45 | */ |
Alexey Dobriyan | 8d65af7 | 2009-09-23 15:57:19 -0700 | [diff] [blame] | 46 | static int proc_do_uts_string(ctl_table *table, int write, |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 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); |
Alexey Dobriyan | 8d65af7 | 2009-09-23 15:57:19 -0700 | [diff] [blame] | 53 | r = proc_dostring(&uts_table,write,buffer,lenp, ppos); |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 54 | put_uts(table, write, uts_table.data); |
Lucas De Marchi | f1ecf06 | 2011-11-02 13:39:22 -0700 | [diff] [blame] | 55 | |
| 56 | if (write) |
| 57 | proc_sys_poll_notify(table->poll); |
| 58 | |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 59 | return r; |
| 60 | } |
| 61 | #else |
| 62 | #define proc_do_uts_string NULL |
| 63 | #endif |
| 64 | |
Lucas De Marchi | f1ecf06 | 2011-11-02 13:39:22 -0700 | [diff] [blame] | 65 | static DEFINE_CTL_TABLE_POLL(hostname_poll); |
| 66 | static DEFINE_CTL_TABLE_POLL(domainname_poll); |
| 67 | |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 68 | static struct ctl_table uts_kern_table[] = { |
| 69 | { |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 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, |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 75 | }, |
| 76 | { |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 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, |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 82 | }, |
| 83 | { |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 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, |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 89 | }, |
| 90 | { |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 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, |
Lucas De Marchi | f1ecf06 | 2011-11-02 13:39:22 -0700 | [diff] [blame] | 96 | .poll = &hostname_poll, |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 97 | }, |
| 98 | { |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 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, |
Lucas De Marchi | f1ecf06 | 2011-11-02 13:39:22 -0700 | [diff] [blame] | 104 | .poll = &domainname_poll, |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 105 | }, |
| 106 | {} |
| 107 | }; |
| 108 | |
| 109 | static struct ctl_table uts_root_table[] = { |
| 110 | { |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 111 | .procname = "kernel", |
| 112 | .mode = 0555, |
| 113 | .child = uts_kern_table, |
| 114 | }, |
| 115 | {} |
| 116 | }; |
| 117 | |
Lucas De Marchi | f1ecf06 | 2011-11-02 13:39:22 -0700 | [diff] [blame] | 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 | */ |
| 123 | void 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 | |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 131 | static int __init utsname_sysctl_init(void) |
| 132 | { |
Eric W. Biederman | 0b4d414 | 2007-02-14 00:34:09 -0800 | [diff] [blame] | 133 | register_sysctl_table(uts_root_table); |
Eric W. Biederman | 39732ac | 2007-02-14 00:33:58 -0800 | [diff] [blame] | 134 | return 0; |
| 135 | } |
| 136 | |
| 137 | __initcall(utsname_sysctl_init); |