[PATCH 15/22][RFC] Unionfs: Privileged operations workqueue

Josef Sipek
2006-09-01T01:55:52Z

From: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu>

Workqueue & helper functions used to perform privileged operations on
behalf of the user process.

Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: David Quigley <dquigley@fsl.cs.sunysb.edu>
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>

---

fs/unionfs/sioq.c | 114 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/unionfs/sioq.h | 79 +++++++++++++++++++++++++++++++++++++
2 files changed, 193 insertions(+)

diff -Nur -x linux-2.6-git/Documentation/dontdiff linux-2.6-git/fs/unionfs/sioq.c linux-2.6-git-unionfs/fs/unionfs/sioq.c
--- linux-2.6-git/fs/unionfs/sioq.c 1969-12-31 19:00:00.000000000 -0500
+++ linux-2.6-git-unionfs/fs/unionfs/sioq.c 2006-08-31 19:04:00.000000000 -0400
@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2003-2006 Erez Zadok
+ * Copyright (c) 2003-2006 Charles P. Wright
+ * Copyright (c) 2005-2006 Josef 'Jeff' Sipek
+ * Copyright (c) 2005-2006 Junjiro Okajima
+ * Copyright (c) 2005 Arun M. Krishnakumar
+ * Copyright (c) 2004-2006 David P. Quigley
+ * Copyright (c) 2003-2004 Mohammad Nayyer Zubair
+ * Copyright (c) 2003 Puja Gupta
+ * Copyright (c) 2003 Harikesavan Krishnan
+ * Copyright (c) 2003-2006 Stony Brook University
+ * Copyright (c) 2003-2006 The Research Foundation of State University of New York
+ *
+ * For specific licensing information, see the COPYING file distributed with
+ * this package.
+ *
+ * This Copyright notice must be kept intact and distributed with all sources.
+ */
+
+#include "union.h"
+
+struct workqueue_struct *sioq;
+
+int __init init_sioq(void)
+{
+ int err;
+
+ sioq = create_workqueue("unionfs_siod");
+ if (!IS_ERR(sioq))
+ return 0;
+
+ err = PTR_ERR(sioq);
+ printk(KERN_ERR "create_workqueue failed %d\n", err);
+ sioq = NULL;
+ return err;
+}
+
+void fin_sioq(void)
+{
+ if (sioq)
+ destroy_workqueue(sioq);
+}
+
+void run_sioq(void (*func)(void *arg), struct sioq_args *args)
+{
+ DECLARE_WORK(wk, func, &args->comp);
+
+ init_completion(&args->comp);
+ while (!queue_work(sioq, &wk)) {
+ // TODO: do accounting if needed
+ schedule();
+ }
+ wait_for_completion(&args->comp);
+}
+
+void __unionfs_create(void *data)
+{
+ struct sioq_args *args = data;
+
+ args->err = vfs_create(args->u.create.parent, args->u.create.dentry,
+ args->u.create.mode, args->u.create.nd);
+ complete(&args->comp);
+}
+
+void __unionfs_mkdir(void *data)
+{
+ struct sioq_args *args = data;
+
+ args->err = vfs_mkdir(args->u.mkdir.parent, args->u.mkdir.dentry,
+ args->u.mkdir.mode);
+ complete(&args->comp);
+}
+
+void __unionfs_mknod(void *data)
+{
+ struct sioq_args *args = data;
+
+ args->err = vfs_mknod(args->u.mknod.parent, args->u.mknod.dentry,
+ args->u.mknod.mode, args->u.mknod.dev);
+ complete(&args->comp);
+}
+void __unionfs_symlink(void *data)
+{
+ struct sioq_args *args = data;
+
+ args->err = vfs_symlink(args->u.symlink.parent, args->u.symlink.dentry,
+ args->u.symlink.symbuf, args->u.symlink.mode);
+}
+
+void __unionfs_unlink(void *data)
+{
+ struct sioq_args *args = data;
+
+ args->err = vfs_unlink(args->u.unlink.parent, args->u.unlink.dentry);
+ complete(&args->comp);
+}
+
+void __delete_whiteouts(void *data) {
+ struct sioq_args *args = data;
+
+ args->err = do_delete_whiteouts(args->u.deletewh.dentry, args->u.deletewh.bindex,
+ args->u.deletewh.namelist);
+
+ complete(&args->comp);
+}
+
+void __is_opaque_dir(void *data)
+{
+ struct sioq_args *args = data;
+
+ args->ret = lookup_one_len(UNIONFS_DIR_OPAQUE, args->u.isopaque.dentry,
+ sizeof(UNIONFS_DIR_OPAQUE) - 1);
+ complete(&args->comp);
+}
diff -Nur -x linux-2.6-git/Documentation/dontdiff linux-2.6-git/fs/unionfs/sioq.h linux-2.6-git-unionfs/fs/unionfs/sioq.h
--- linux-2.6-git/fs/unionfs/sioq.h 1969-12-31 19:00:00.000000000 -0500
+++ linux-2.6-git-unionfs/fs/unionfs/sioq.h 2006-08-31 19:04:01.000000000 -0400
@@ -0,0 +1,79 @@
+#ifndef _SIOQ_H
+#define _SIOQ_H
+
+struct deletewh_args {
+ struct unionfs_dir_state *namelist;
+ struct dentry *dentry;
+ int bindex;
+};
+
+struct isopaque_args {
+ struct dentry *dentry;
+};
+
+struct create_args {
+ struct inode *parent;
+ struct dentry *dentry;
+ umode_t mode;
+ struct nameidata *nd;
+};
+
+struct mkdir_args {
+ struct inode *parent;
+ struct dentry *dentry;
+ umode_t mode;
+};
+
+struct mknod_args {
+ struct inode *parent;
+ struct dentry *dentry;
+ umode_t mode;
+ dev_t dev;
+};
+
+struct symlink_args {
+ struct inode *parent;
+ struct dentry *dentry;
+ char *symbuf;
+ umode_t mode;
+};
+
+struct unlink_args {
+ struct inode *parent;
+ struct dentry *dentry;
+};
+
+
+struct sioq_args {
+
+ struct completion comp;
+ int err;
+ void *ret;
+
+ union {
+ struct deletewh_args deletewh;
+ struct isopaque_args isopaque;
+ struct create_args create;
+ struct mkdir_args mkdir;
+ struct mknod_args mknod;
+ struct symlink_args symlink;
+ struct unlink_args unlink;
+ } u;
+};
+
+extern struct workqueue_struct *sioq;
+int __init init_sioq(void);
+extern void fin_sioq(void);
+extern void run_sioq(void (*func)(void *arg), struct sioq_args *args);
+
+/* Extern definitions for our privledge escalation helpers */
+extern void __unionfs_create(void *data);
+extern void __unionfs_mkdir(void *data);
+extern void __unionfs_mknod(void *data);
+extern void __unionfs_symlink(void *data);
+extern void __unionfs_unlink(void *data);
+extern void __delete_whiteouts(void *data);
+extern void __is_opaque_dir(void *data);
+
+#endif /* _SIOQ_H */
+