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-rw-r--r--kernel/nsproxy.c139
1 files changed, 139 insertions, 0 deletions
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
new file mode 100644
index 00000000000..6ebdb82a0ce
--- /dev/null
+++ b/kernel/nsproxy.c
@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) 2006 IBM Corporation
+ *
+ * Author: Serge Hallyn <serue@us.ibm.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.
+ *
+ * Jun 2006 - namespaces support
+ * OpenVZ, SWsoft Inc.
+ * Pavel Emelianov <xemul@openvz.org>
+ */
+
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/nsproxy.h>
+#include <linux/init_task.h>
+#include <linux/namespace.h>
+#include <linux/utsname.h>
+
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
+
+static inline void get_nsproxy(struct nsproxy *ns)
+{
+ atomic_inc(&ns->count);
+}
+
+void get_task_namespaces(struct task_struct *tsk)
+{
+ struct nsproxy *ns = tsk->nsproxy;
+ if (ns) {
+ get_nsproxy(ns);
+ }
+}
+
+/*
+ * creates a copy of "orig" with refcount 1.
+ * This does not grab references to the contained namespaces,
+ * so that needs to be done by dup_namespaces.
+ */
+static inline struct nsproxy *clone_namespaces(struct nsproxy *orig)
+{
+ struct nsproxy *ns;
+
+ ns = kmalloc(sizeof(struct nsproxy), GFP_KERNEL);
+ if (ns) {
+ memcpy(ns, orig, sizeof(struct nsproxy));
+ atomic_set(&ns->count, 1);
+ }
+ return ns;
+}
+
+/*
+ * copies the nsproxy, setting refcount to 1, and grabbing a
+ * reference to all contained namespaces. Called from
+ * sys_unshare()
+ */
+struct nsproxy *dup_namespaces(struct nsproxy *orig)
+{
+ struct nsproxy *ns = clone_namespaces(orig);
+
+ if (ns) {
+ if (ns->namespace)
+ get_namespace(ns->namespace);
+ if (ns->uts_ns)
+ get_uts_ns(ns->uts_ns);
+ if (ns->ipc_ns)
+ get_ipc_ns(ns->ipc_ns);
+ }
+
+ return ns;
+}
+
+/*
+ * called from clone. This now handles copy for nsproxy and all
+ * namespaces therein.
+ */
+int copy_namespaces(int flags, struct task_struct *tsk)
+{
+ struct nsproxy *old_ns = tsk->nsproxy;
+ struct nsproxy *new_ns;
+ int err = 0;
+
+ if (!old_ns)
+ return 0;
+
+ get_nsproxy(old_ns);
+
+ if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC)))
+ return 0;
+
+ new_ns = clone_namespaces(old_ns);
+ if (!new_ns) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ tsk->nsproxy = new_ns;
+
+ err = copy_namespace(flags, tsk);
+ if (err)
+ goto out_ns;
+
+ err = copy_utsname(flags, tsk);
+ if (err)
+ goto out_uts;
+
+ err = copy_ipcs(flags, tsk);
+ if (err)
+ goto out_ipc;
+
+out:
+ put_nsproxy(old_ns);
+ return err;
+
+out_ipc:
+ if (new_ns->uts_ns)
+ put_uts_ns(new_ns->uts_ns);
+out_uts:
+ if (new_ns->namespace)
+ put_namespace(new_ns->namespace);
+out_ns:
+ tsk->nsproxy = old_ns;
+ kfree(new_ns);
+ goto out;
+}
+
+void free_nsproxy(struct nsproxy *ns)
+{
+ if (ns->namespace)
+ put_namespace(ns->namespace);
+ if (ns->uts_ns)
+ put_uts_ns(ns->uts_ns);
+ if (ns->ipc_ns)
+ put_ipc_ns(ns->ipc_ns);
+ kfree(ns);
+}