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 18 static void *get_uts(ctl_table *table, int write) 19 { 20 char *which = table->data; 21 22 if (!write) 23 down_read(&uts_sem); 24 else 25 down_write(&uts_sem); 26 return which; 27 } 28 29 static void put_uts(ctl_table *table, int write, void *which) 30 { 31 if (!write) 32 up_read(&uts_sem); 33 else 34 up_write(&uts_sem); 35 } 36 37 #ifdef CONFIG_PROC_FS 38 /* 39 * Special case of dostring for the UTS structure. This has locks 40 * to observe. Should this be in kernel/sys.c ???? 41 */ 42 static int proc_do_uts_string(ctl_table *table, int write, struct file *filp, 43 void __user *buffer, size_t *lenp, loff_t *ppos) 44 { 45 struct ctl_table uts_table; 46 int r; 47 memcpy(&uts_table, table, sizeof(uts_table)); 48 uts_table.data = get_uts(table, write); 49 r = proc_dostring(&uts_table,write,filp,buffer,lenp, ppos); 50 put_uts(table, write, uts_table.data); 51 return r; 52 } 53 #else 54 #define proc_do_uts_string NULL 55 #endif 56 57 58 #ifdef CONFIG_SYSCTL_SYSCALL 59 /* The generic string strategy routine: */ 60 static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen, 61 void __user *oldval, size_t __user *oldlenp, 62 void __user *newval, size_t newlen) 63 { 64 struct ctl_table uts_table; 65 int r, write; 66 write = newval && newlen; 67 memcpy(&uts_table, table, sizeof(uts_table)); 68 uts_table.data = get_uts(table, write); 69 r = sysctl_string(&uts_table, name, nlen, 70 oldval, oldlenp, newval, newlen); 71 put_uts(table, write, uts_table.data); 72 return r; 73 } 74 #else 75 #define sysctl_uts_string NULL 76 #endif 77 78 static struct ctl_table uts_kern_table[] = { 79 { 80 .ctl_name = KERN_OSTYPE, 81 .procname = "ostype", 82 .data = init_uts_ns.name.sysname, 83 .maxlen = sizeof(init_uts_ns.name.sysname), 84 .mode = 0444, 85 .proc_handler = proc_do_uts_string, 86 .strategy = sysctl_uts_string, 87 }, 88 { 89 .ctl_name = KERN_OSRELEASE, 90 .procname = "osrelease", 91 .data = init_uts_ns.name.release, 92 .maxlen = sizeof(init_uts_ns.name.release), 93 .mode = 0444, 94 .proc_handler = proc_do_uts_string, 95 .strategy = sysctl_uts_string, 96 }, 97 { 98 .ctl_name = KERN_VERSION, 99 .procname = "version", 100 .data = init_uts_ns.name.version, 101 .maxlen = sizeof(init_uts_ns.name.version), 102 .mode = 0444, 103 .proc_handler = proc_do_uts_string, 104 .strategy = sysctl_uts_string, 105 }, 106 { 107 .ctl_name = KERN_NODENAME, 108 .procname = "hostname", 109 .data = init_uts_ns.name.nodename, 110 .maxlen = sizeof(init_uts_ns.name.nodename), 111 .mode = 0644, 112 .proc_handler = proc_do_uts_string, 113 .strategy = sysctl_uts_string, 114 }, 115 { 116 .ctl_name = KERN_DOMAINNAME, 117 .procname = "domainname", 118 .data = init_uts_ns.name.domainname, 119 .maxlen = sizeof(init_uts_ns.name.domainname), 120 .mode = 0644, 121 .proc_handler = proc_do_uts_string, 122 .strategy = sysctl_uts_string, 123 }, 124 {} 125 }; 126 127 static struct ctl_table uts_root_table[] = { 128 { 129 .ctl_name = CTL_KERN, 130 .procname = "kernel", 131 .mode = 0555, 132 .child = uts_kern_table, 133 }, 134 {} 135 }; 136 137 static int __init utsname_sysctl_init(void) 138 { 139 register_sysctl_table(uts_root_table); 140 return 0; 141 } 142 143 __initcall(utsname_sysctl_init); 144