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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..324aa1341b5f
--- /dev/null
+++ b/kernel/utsname_sysctl.c
@@ -0,0 +1,146 @@
+/*
+ * 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/module.h>
+#include <linux/uts.h>
+#include <linux/utsname.h>
+#include <linux/version.h>
+#include <linux/sysctl.h>
+
+static void *get_uts(ctl_table *table, int write)
+{
+ char *which = table->data;
+#ifdef CONFIG_UTS_NS
+ struct uts_namespace *uts_ns = current->nsproxy->uts_ns;
+ which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
+#endif
+ 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_FS
+/*
+ * 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, struct file *filp,
+ 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,filp,buffer,lenp, ppos);
+ put_uts(table, write, uts_table.data);
+ return r;
+}
+#else
+#define proc_do_uts_string NULL
+#endif
+
+
+#ifdef CONFIG_SYSCTL_SYSCALL
+/* The generic string strategy routine: */
+static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen,
+ void __user *oldval, size_t __user *oldlenp,
+ void __user *newval, size_t newlen)
+{
+ struct ctl_table uts_table;
+ int r, write;
+ write = newval && newlen;
+ memcpy(&uts_table, table, sizeof(uts_table));
+ uts_table.data = get_uts(table, write);
+ r = sysctl_string(&uts_table, name, nlen,
+ oldval, oldlenp, newval, newlen);
+ put_uts(table, write, uts_table.data);
+ return r;
+}
+#else
+#define sysctl_uts_string NULL
+#endif
+
+static struct ctl_table uts_kern_table[] = {
+ {
+ .ctl_name = KERN_OSTYPE,
+ .procname = "ostype",
+ .data = init_uts_ns.name.sysname,
+ .maxlen = sizeof(init_uts_ns.name.sysname),
+ .mode = 0444,
+ .proc_handler = proc_do_uts_string,
+ .strategy = sysctl_uts_string,
+ },
+ {
+ .ctl_name = KERN_OSRELEASE,
+ .procname = "osrelease",
+ .data = init_uts_ns.name.release,
+ .maxlen = sizeof(init_uts_ns.name.release),
+ .mode = 0444,
+ .proc_handler = proc_do_uts_string,
+ .strategy = sysctl_uts_string,
+ },
+ {
+ .ctl_name = KERN_VERSION,
+ .procname = "version",
+ .data = init_uts_ns.name.version,
+ .maxlen = sizeof(init_uts_ns.name.version),
+ .mode = 0444,
+ .proc_handler = proc_do_uts_string,
+ .strategy = sysctl_uts_string,
+ },
+ {
+ .ctl_name = KERN_NODENAME,
+ .procname = "hostname",
+ .data = init_uts_ns.name.nodename,
+ .maxlen = sizeof(init_uts_ns.name.nodename),
+ .mode = 0644,
+ .proc_handler = proc_do_uts_string,
+ .strategy = sysctl_uts_string,
+ },
+ {
+ .ctl_name = KERN_DOMAINNAME,
+ .procname = "domainname",
+ .data = init_uts_ns.name.domainname,
+ .maxlen = sizeof(init_uts_ns.name.domainname),
+ .mode = 0644,
+ .proc_handler = proc_do_uts_string,
+ .strategy = sysctl_uts_string,
+ },
+ {}
+};
+
+static struct ctl_table uts_root_table[] = {
+ {
+ .ctl_name = CTL_KERN,
+ .procname = "kernel",
+ .mode = 0555,
+ .child = uts_kern_table,
+ },
+ {}
+};
+
+static int __init utsname_sysctl_init(void)
+{
+ register_sysctl_table(uts_root_table, 0);
+ return 0;
+}
+
+__initcall(utsname_sysctl_init);