From: Josef "Jeff" Sipek <jsipek@xxxxxxxxxxxxx>
Workqueue & helper functions used to perform privileged operations on
behalf of the user process.
Signed-off-by: Josef "Jeff" Sipek <jsipek@xxxxxxxxxxxxx>
Signed-off-by: David Quigley <dquigley@xxxxxxxxxxxxxxxxx>
Signed-off-by: Erez Zadok <ezk@xxxxxxxxxxxxx>
---
fs/unionfs/sioq.c | 122 +++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/unionfs/sioq.h | 79 ++++++++++++++++++++++++++++++++++
2 files changed, 201 insertions(+), 0 deletions(-)
diff --git a/fs/unionfs/sioq.c b/fs/unionfs/sioq.c
new file mode 100644
index 0000000..444a3e5
--- /dev/null
+++ b/fs/unionfs/sioq.c
@@ -0,0 +1,122 @@
+/*
+ * 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
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "union.h"
+
+/* Super-user IO work Queue - sometimes we need to perform actions which
+ * would fail due to the unix permissions on the parent directory (e.g.,
+ * rmdir a directory which appears empty, but in reality contains
+ * whiteouts).
+ */
+
+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 __exit stop_sioq(void)
+{
+ if (sioq)
+ destroy_workqueue(sioq);
+}
+
+void run_sioq(work_func_t func, struct sioq_args *args)
+{
+ INIT_WORK(&args->work, func);
+
+ init_completion(&args->comp);
+ while (!queue_work(sioq, &args->work)) {
+ /* TODO: do accounting if needed */
+ schedule();
+ }
+ wait_for_completion(&args->comp);
+}
+
+void __unionfs_create(struct work_struct *work)
+{
+ struct sioq_args *args = container_of(work, struct sioq_args, work);
+ struct create_args *c = &args->create;
+
+ args->err = vfs_create(c->parent, c->dentry, c->mode, c->nd);
+ complete(&args->comp);
+}
+
+void __unionfs_mkdir(struct work_struct *work)
+{
+ struct sioq_args *args = container_of(work, struct sioq_args, work);
+ struct mkdir_args *m = &args->mkdir;
+
+ args->err = vfs_mkdir(m->parent, m->dentry, m->mode);
+ complete(&args->comp);
+}
+
+void __unionfs_mknod(struct work_struct *work)
+{
+ struct sioq_args *args = container_of(work, struct sioq_args, work);
+ struct mknod_args *m = &args->mknod;
+
+ args->err = vfs_mknod(m->parent, m->dentry, m->mode, m->dev);
+ complete(&args->comp);
+}
+
+void __unionfs_symlink(struct work_struct *work)
+{
+ struct sioq_args *args = container_of(work, struct sioq_args, work);
+ struct symlink_args *s = &args->symlink;
+
+ args->err = vfs_symlink(s->parent, s->dentry, s->symbuf, s->mode);
+ complete(&args->comp);
+}
+
+void __unionfs_unlink(struct work_struct *work)
+{
+ struct sioq_args *args = container_of(work, struct sioq_args, work);
+ struct unlink_args *u = &args->unlink;
+
+ args->err = vfs_unlink(u->parent, u->dentry);
+ complete(&args->comp);
+}
+
+void __delete_whiteouts(struct work_struct *work) {
+ struct sioq_args *args = container_of(work, struct sioq_args, work);
+ struct deletewh_args *d = &args->deletewh;
+
+ args->err = do_delete_whiteouts(d->dentry, d->bindex, d->namelist);
+ complete(&args->comp);
+}
+
+void __is_opaque_dir(struct work_struct *work)
+{
+ struct sioq_args *args = container_of(work, struct sioq_args, work);
+
+ args->ret = lookup_one_len(UNIONFS_DIR_OPAQUE, args->is_opaque.dentry,
+ sizeof(UNIONFS_DIR_OPAQUE) - 1);
+ complete(&args->comp);
+}
+
diff --git a/fs/unionfs/sioq.h b/fs/unionfs/sioq.h
new file mode 100644
index 0000000..5a93414
--- /dev/null
+++ b/fs/unionfs/sioq.h
@@ -0,0 +1,79 @@
+#ifndef _SIOQ_H
+#define _SIOQ_H
+
+struct deletewh_args {
+ struct unionfs_dir_state *namelist;
+ struct dentry *dentry;
+ int bindex;
+};
+
+struct is_opaque_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;
+ struct work_struct work;
+ int err;
+ void *ret;
+
+ union {
+ struct deletewh_args deletewh;
+ struct is_opaque_args is_opaque;
+ struct create_args create;
+ struct mkdir_args mkdir;
+ struct mknod_args mknod;
+ struct symlink_args symlink;
+ struct unlink_args unlink;
+ };
+};
+
+extern struct workqueue_struct *sioq;
+extern int __init init_sioq(void);
+extern __exit void stop_sioq(void);
+extern void run_sioq(work_func_t func, struct sioq_args *args);
+
+/* Extern definitions for our privlege escalation helpers */
+extern void __unionfs_create(struct work_struct *work);
+extern void __unionfs_mkdir(struct work_struct *work);
+extern void __unionfs_mknod(struct work_struct *work);
+extern void __unionfs_symlink(struct work_struct *work);
+extern void __unionfs_unlink(struct work_struct *work);
+extern void __delete_whiteouts(struct work_struct *work);
+extern void __is_opaque_dir(struct work_struct *work);
+
+#endif /* _SIOQ_H */
+
--
1.4.4.2
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