/* * Copyright (C) 2007 * * Author: Eric Biederman <ebiederm@xmision.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation, version 2 of the * License. */ #include <linux/export.h> #include <linux/uts.h> #include <linux/utsname.h> #include <linux/sysctl.h> #include <linux/wait.h> static void *get_uts(ctl_table *table, int write) { char *which = table->data; struct uts_namespace *uts_ns; uts_ns = current->nsproxy->uts_ns; which = (which - (char *)&init_uts_ns) + (char *)uts_ns; if (!write) down_read(&uts_sem); else down_write(&uts_sem); return which; } static void put_uts(ctl_table *table, int write, void *which) { if (!write) up_read(&uts_sem); else up_write(&uts_sem); } #ifdef CONFIG_PROC_SYSCTL /* * Special case of dostring for the UTS structure. This has locks * to observe. Should this be in kernel/sys.c ???? */ static int proc_do_uts_string(ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct ctl_table uts_table; int r; memcpy(&uts_table, table, sizeof(uts_table)); uts_table.data = get_uts(table, write); r = proc_dostring(&uts_table,write,buffer,lenp, ppos); put_uts(table, write, uts_table.data); if (write) proc_sys_poll_notify(table->poll); return r; } #else #define proc_do_uts_string NULL #endif static DEFINE_CTL_TABLE_POLL(hostname_poll); static DEFINE_CTL_TABLE_POLL(domainname_poll); static struct ctl_table uts_kern_table[] = { { .procname = "ostype", .data = init_uts_ns.name.sysname, .maxlen = sizeof(init_uts_ns.name.sysname), .mode = 0444, .proc_handler = proc_do_uts_string, }, { .procname = "osrelease", .data = init_uts_ns.name.release, .maxlen = sizeof(init_uts_ns.name.release), .mode = 0444, .proc_handler = proc_do_uts_string, }, { .procname = "version", .data = init_uts_ns.name.version, .maxlen = sizeof(init_uts_ns.name.version), .mode = 0444, .proc_handler = proc_do_uts_string, }, { .procname = "hostname", .data = init_uts_ns.name.nodename, .maxlen = sizeof(init_uts_ns.name.nodename), .mode = 0644, .proc_handler = proc_do_uts_string, .poll = &hostname_poll, }, { .procname = "domainname", .data = init_uts_ns.name.domainname, .maxlen = sizeof(init_uts_ns.name.domainname), .mode = 0644, .proc_handler = proc_do_uts_string, .poll = &domainname_poll, }, {} }; static struct ctl_table uts_root_table[] = { { .procname = "kernel", .mode = 0555, .child = uts_kern_table, }, {} }; #ifdef CONFIG_PROC_SYSCTL /* * Notify userspace about a change in a certain entry of uts_kern_table, * identified by the parameter proc. */ void uts_proc_notify(enum uts_proc proc) { struct ctl_table *table = &uts_kern_table[proc]; proc_sys_poll_notify(table->poll); } #endif static int __init utsname_sysctl_init(void) { register_sysctl_table(uts_root_table); return 0; } __initcall(utsname_sysctl_init);