Created the most basic one-node libnetfs-based stackable translator.

The filter is going to be an ordinary translator in most
regards, save for its attitude towards the translators
sitting on the real filesystem node associated with the
mirror on which the filter is sitting (see README).

9 files changed, 2393 insertions, 0 deletions

diff --git a/REAMDE b/REAMDE
new file mode 100644
index 000000000..a162403f8
--- /dev/null
+++ b/REAMDE
@@ -0,0 +1,10 @@
+FILTER TRANSLATOR FOR NSMUX
+
+filter is GNU/Hurd translator designed specifically to be used in
+namespace-based translator selection, that is with nsmux. When set on
+a file this translator will traverse the stack of static translators
+(which sit on the real filesystem node) and stop at the translator
+whose name matches the name provided to the filter on the command
+line. It will then read and write data using this translator, i.e. all
+translators sitting upon this translator and below the filter will be
+shunted.
diff --git a/debug.h b/debug.h
new file mode 100644
index 000000000..254226737
--- /dev/null
+++ b/debug.h
@@ -0,0 +1,59 @@
+/*----------------------------------------------------------------------------*/
+/*debug.h*/
+/*----------------------------------------------------------------------------*/
+/*Simple facilities for debugging messages*/
+/*----------------------------------------------------------------------------*/
+/*Based on the code of unionfs translator.*/
+/*----------------------------------------------------------------------------*/
+/*Copyright (C) 2001, 2002, 2005, 2008 Free Software Foundation, Inc.
+  Written by Sergiu Ivanov <unlimitedscolobb@gmail.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; either version 2 of the
+  License, or * (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.*/
+/*----------------------------------------------------------------------------*/
+#ifndef __DEBUG_H__
+#define __DEBUG_H__
+
+/*----------------------------------------------------------------------------*/
+#include <stdio.h>
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Macros--------------------------------------------------------------*/
+/*Print debug messages here*/
+#define DEBUG_OUTPUT "/var/log/filter.dbg"
+/*----------------------------------------------------------------------------*/
+#ifdef DEBUG
+	/*Initializes the log*/
+#	define INIT_LOG() filter_dbg = fopen(DEBUG_OUTPUT, "wt")
+	/*Closes the log*/
+# define CLOSE_LOG() fclose(filter_dbg)
+	/*Prints a debug message and flushes the debug output*/
+#	define LOG_MSG(fmt, args...) {fprintf(filter_dbg, fmt"\n", ##args);\
+		fflush(filter_dbg);}
+#else
+	/*Remove requests for debugging output*/
+#	define INIT_LOG()
+#	define CLOSE_LOG()
+#	define LOG_MSG(fmt, args...)
+#endif /*DEBUG*/
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Global Variables----------------------------------------------------*/
+/*The file to write debugging info to*/
+extern FILE * filter_dbg;
+/*----------------------------------------------------------------------------*/
+#endif /*__DEBUG_H__*/
diff --git a/filter.c b/filter.c
new file mode 100644
index 000000000..09a409cb2
--- /dev/null
+++ b/filter.c
@@ -0,0 +1,726 @@
+/*----------------------------------------------------------------------------*/
+/*filter.c*/
+/*----------------------------------------------------------------------------*/
+/*The filtering translator*/
+/*----------------------------------------------------------------------------*/
+/*Based on the code of unionfs translator.*/
+/*----------------------------------------------------------------------------*/
+/*Copyright (C) 2001, 2002, 2005, 2008 Free Software Foundation, Inc.
+  Written by Sergiu Ivanov <unlimitedscolobb@gmail.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; either version 2 of the
+  License, or * (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.*/
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+#define _GNU_SOURCE 1
+/*----------------------------------------------------------------------------*/
+#include "filter.h"
+/*----------------------------------------------------------------------------*/
+#include <error.h>
+#include <argp.h>
+#include <argz.h>
+#include <hurd/netfs.h>
+#include <fcntl.h>
+/*----------------------------------------------------------------------------*/
+#include "debug.h"
+#include "options.h"
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Global Variables----------------------------------------------------*/
+/*The name of the server*/
+char * netfs_server_name = "filter";
+/*----------------------------------------------------------------------------*/
+/*The version of the server*/
+char * netfs_server_version = "0.0";
+/*----------------------------------------------------------------------------*/
+/*The maximal length of a chain of symbolic links*/
+int netfs_maxsymlinks = 12;
+/*----------------------------------------------------------------------------*/
+/*A port to the underlying node*/
+mach_port_t underlying_node;
+/*----------------------------------------------------------------------------*/
+/*Status information for the underlying node*/
+io_statbuf_t underlying_node_stat;
+/*----------------------------------------------------------------------------*/
+/*Mapped time used for updating node information*/
+volatile struct mapped_time_value * maptime;
+/*----------------------------------------------------------------------------*/
+/*The filesystem ID*/
+pid_t fsid;
+/*----------------------------------------------------------------------------*/
+/*The port from which we will read (TODO: and write) the data*/
+mach_port_t target;
+/*----------------------------------------------------------------------------*/
+/*The file to print debug messages to*/
+FILE * filter_dbg;
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Functions-----------------------------------------------------------*/
+/*Attempts to create a file named `name` in `dir` for `user` with mode `mode`*/
+error_t
+netfs_attempt_create_file
+	(
+	struct iouser * user,
+	struct node * dir,
+	char * name,
+	mode_t mode,
+	struct node ** node
+	)
+	{
+	LOG_MSG("netfs_attempt_create_file");
+
+	/*Unlock `dir` and say that we can do nothing else here*/
+	mutex_unlock(&dir->lock);
+	return EOPNOTSUPP;
+	}/*netfs_attempt_create_file*/
+/*----------------------------------------------------------------------------*/
+/*Return an error if the process of opening a file should not be allowed
+	to complete because of insufficient permissions*/
+error_t
+netfs_check_open_permissions
+	(
+	struct iouser * user,
+	struct node * np,
+	int flags,
+	int newnode
+	)
+	{
+	LOG_MSG("netfs_check_open_permissions");
+
+	error_t err = 0;
+	
+	/*Cheks user's permissions*/
+	if(flags & O_READ)
+		err = fshelp_access(&np->nn_stat, S_IREAD, user);
+	if(!err && (flags & O_WRITE))
+		err = fshelp_access(&np->nn_stat, S_IWRITE, user);
+	if(!err && (flags & O_EXEC))
+		err = fshelp_access(&np->nn_stat, S_IEXEC, user);
+		
+	/*Return the result of the check*/
+	return err;
+	}/*netfs_check_open_permissions*/
+/*----------------------------------------------------------------------------*/
+/*Attempts an utimes call for the user `cred` on node `node`*/
+error_t
+netfs_attempt_utimes
+	(
+	struct iouser * cred,
+	struct node * node,
+	struct timespec * atime,
+	struct timespec * mtime
+	)
+	{
+	LOG_MSG("netfs_attempt_utimes");
+
+	error_t err = 0;
+	
+	/*See what information is to be updated*/
+	int flags = TOUCH_CTIME;
+	
+	/*Check if the user is indeed the owner of the node*/
+	err = fshelp_isowner(&node->nn_stat, cred);
+	
+	/*If the user is allowed to do utimes*/
+	if(!err)
+		{
+		/*If atime is to be updated*/
+		if(atime)
+			/*update the atime*/
+			node->nn_stat.st_atim = *atime;
+		else
+			/*the current time will be set as the atime*/
+			flags |= TOUCH_ATIME;
+		
+		/*If mtime is to be updated*/
+		if(mtime)
+			/*update the mtime*/
+			node->nn_stat.st_mtim = *mtime;
+		else
+			/*the current time will be set as mtime*/
+			flags |= TOUCH_MTIME;
+		
+		/*touch the file*/
+		fshelp_touch(&node->nn_stat, flags, maptime);
+		}
+	
+	/*Return the result of operations*/
+	return err;
+	}/*netfs_attempt_utimes*/
+/*----------------------------------------------------------------------------*/
+/*Returns the valid access types for file `node` and user `cred`*/
+error_t
+netfs_report_access
+	(
+	struct iouser * cred,
+	struct node * np,
+	int * types
+	)
+	{
+	LOG_MSG("netfs_report_access");
+
+	/*No access at first*/
+	*types = 0;
+	
+	/*Check the access and set the required bits*/
+	if(fshelp_access(&np->nn_stat, S_IREAD,  cred) == 0)
+		*types |= O_READ;
+	if(fshelp_access(&np->nn_stat, S_IWRITE, cred) == 0)
+		*types |= O_WRITE;
+	if(fshelp_access(&np->nn_stat, S_IEXEC,  cred) == 0)
+		*types |= O_EXEC;
+
+	/*Everything OK*/
+	return 0;
+	}/*netfs_report_access*/
+/*----------------------------------------------------------------------------*/
+/*Validates the stat data for the node*/
+error_t
+netfs_validate_stat
+	(
+	struct node * np,
+	struct iouser * cred
+	)
+	{
+	LOG_MSG("netfs_validate_stat");
+
+	error_t err = 0;
+	
+	/*Validate the stat information about the node*/
+	err = io_stat(np->nn->port, &np->nn_stat);
+
+	/*Return the result of operations*/
+	return err;
+	}/*netfs_validate_stat*/
+/*----------------------------------------------------------------------------*/
+/*Syncs `node` completely to disk*/
+error_t
+netfs_attempt_sync
+	(
+	struct iouser * cred,
+	struct node * node,
+	int wait
+	)
+	{
+	LOG_MSG("netfs_attempt_sync");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_sync*/
+/*----------------------------------------------------------------------------*/
+/*Fetches a directory*/
+error_t
+netfs_get_dirents
+	(
+	struct iouser * cred,
+	struct node * dir,
+	int first_entry,
+	int num_entries,
+	char ** data,
+	mach_msg_type_number_t * data_len,
+	vm_size_t max_data_len,
+	int * data_entries
+	)
+	{
+	LOG_MSG("netfs_get_dirents");
+	
+	/*This node is not a directory*/
+	return ENOTDIR;
+	}/*netfs_get_dirents*/
+/*----------------------------------------------------------------------------*/
+/*Looks up `name` under `dir` for `user`*/
+error_t
+netfs_attempt_lookup
+	(
+	struct iouser * user,
+	struct node * dir,
+	char * name,
+	struct node ** node
+	)
+	{
+	LOG_MSG("netfs_attempt_lookup: '%s'", name);
+		
+	/*Unlock the mutexes in `dir`*/
+	mutex_unlock(&dir->lock);
+	return EOPNOTSUPP;
+	}/*netfs_attempt_lookup*/
+/*----------------------------------------------------------------------------*/
+/*Deletes `name` in `dir` for `user`*/
+error_t
+netfs_attempt_unlink
+	(
+	struct iouser * user,
+	struct node * dir,
+	char * name
+	)
+	{
+	LOG_MSG("netfs_attempt_unlink");
+
+	return 0;
+	}/*netfs_attempt_unlink*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to rename `fromdir`/`fromname` to `todir`/`toname`*/
+error_t
+netfs_attempt_rename
+	(
+	struct iouser * user,
+	struct node * fromdir,
+	char * fromname,
+	struct node * todir,
+	char * toname,
+	int excl
+	)
+	{
+	LOG_MSG("netfs_attempt_rename");
+
+	/*Operation not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_rename*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to create a new directory*/
+error_t
+netfs_attempt_mkdir
+	(
+	struct iouser * user,
+	struct node * dir,
+	char * name,
+	mode_t mode
+	)
+	{
+	LOG_MSG("netfs_attempt_mkdir");
+
+	return 0;
+	}/*netfs_attempt_mkdir*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to remove directory `name` in `dir` for `user`*/
+error_t
+netfs_attempt_rmdir
+	(
+	struct iouser * user,
+	struct node * dir,
+	char * name
+	)
+	{
+	LOG_MSG("netfs_attempt_rmdir");
+
+	return 0;
+	}/*netfs_attempt_rmdir*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to change the mode of `node` for user `cred` to `uid`:`gid`*/
+error_t
+netfs_attempt_chown
+	(
+	struct iouser * cred,
+	struct node * node,
+	uid_t uid,
+	uid_t gid
+	)
+	{
+	LOG_MSG("netfs_attempt_chown");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_chown*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to change the author of `node` to `author`*/
+error_t
+netfs_attempt_chauthor
+	(
+	struct iouser * cred,
+	struct node * node,
+	uid_t author
+	)
+	{
+	LOG_MSG("netfs_attempt_chauthor");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_chauthor*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to change the mode of `node` to `mode` for `cred`*/
+error_t
+netfs_attempt_chmod
+	(
+	struct iouser * user,
+	struct node * node,
+	mode_t mode
+	)
+	{
+	LOG_MSG("netfs_attempt_chmod");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_chmod*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to turn `node` into a symlink targetting `name`*/
+error_t
+netfs_attempt_mksymlink
+	(
+	struct iouser * cred,
+	struct node * node,
+	char * name
+	)
+	{
+	LOG_MSG("netfs_attempt_mksymlink");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_mksymlink*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to turn `node` into a device; type can be either S_IFBLK or S_IFCHR*/
+error_t
+netfs_attempt_mkdev
+	(
+	struct iouser * cred,
+	struct node * node,
+	mode_t type,
+	dev_t indexes
+	)
+	{
+	LOG_MSG("netfs_attempt_mkdev");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_mkdev*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to set the passive translator record for `file` passing `argz`*/
+error_t
+netfs_set_translator
+	(
+	struct iouser * cred,
+	struct node * node,
+	char * argz,
+	size_t arglen
+	)
+	{
+	LOG_MSG("netfs_set_translator");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_set_translator	*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to call chflags for `node`*/
+error_t
+netfs_attempt_chflags
+	(
+	struct iouser * cred,
+	struct node * node,
+	int flags
+	)
+	{
+	LOG_MSG("netfs_attempt_chflags");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_chflags*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to set the size of file `node`*/
+error_t
+netfs_attempt_set_size
+	(
+	struct iouser * cred,
+	struct node * node,
+	loff_t size
+	)
+	{
+	LOG_MSG("netfs_attempt_set_size");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_set_size*/
+/*----------------------------------------------------------------------------*/
+/*Fetches the filesystem status information*/
+error_t
+netfs_attempt_statfs
+	(
+	struct iouser * cred,
+	struct node * node,
+	fsys_statfsbuf_t * st
+	)
+	{
+	LOG_MSG("netfs_attempt_statfs");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_statfs*/
+/*----------------------------------------------------------------------------*/
+/*Syncs the filesystem*/
+error_t
+netfs_attempt_syncfs
+	(
+	struct iouser * cred,
+	int wait
+	)
+	{
+	LOG_MSG("netfs_attempt_syncfs");
+
+	/*Everythin OK*/
+	return 0;
+	}/*netfs_attempt_syncfs*/
+/*----------------------------------------------------------------------------*/
+/*Creates a link in `dir` with `name` to `file`*/
+error_t
+netfs_attempt_link
+	(
+	struct iouser * user,
+	struct node * dir,
+	struct node * file,
+	char * name,
+	int excl
+	)
+	{
+	LOG_MSG("netfs_attempt_link");
+
+	/*Operation not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_link*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to create an anonymous file related to `dir` with `mode`*/
+error_t
+netfs_attempt_mkfile
+	(
+	struct iouser * user,
+	struct node * dir,
+	mode_t mode,
+	struct node ** node
+	)
+	{
+	LOG_MSG("netfs_attempt_mkfile");
+
+	/*Unlock the directory*/
+	mutex_unlock(&dir->lock);
+
+	/*Operation not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_mkfile*/
+/*----------------------------------------------------------------------------*/
+/*Reads the contents of symlink `node` into `buf`*/
+error_t
+netfs_attempt_readlink
+	(
+	struct iouser * user,
+	struct node * node,
+	char * buf
+	)
+	{
+	LOG_MSG("netfs_attempt_readlink");
+
+	/*Operation not supported (why?..)*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_readlink*/
+/*----------------------------------------------------------------------------*/
+/*Reads from file `node` up to `len` bytes from `offset` into `data`*/
+error_t
+netfs_attempt_read
+	(
+	struct iouser * cred,
+	struct node * np,
+	loff_t offset,
+	size_t * len,
+	void * data
+	)
+	{
+	LOG_MSG("netfs_attempt_read");
+
+	error_t err = 0;
+
+	/*Obtain a pointer to the first byte of the supplied buffer*/
+	char * buf = data;
+	
+	/*Try to read the requested information from the file*/
+	err = io_read(np->nn->port, &buf, len, offset, *len);
+	
+	/*If some data has been read successfully*/
+	if(!err && (buf != data))
+		{
+		/*copy the data from the buffer into which it has just been read into
+			the supplied receiver*/
+		memcpy(data, buf, *len);
+		
+		/*unmap the new buffer*/
+		munmap(buf, *len);
+		}
+
+	/*Return the result of reading*/
+	return err;
+	}/*netfs_attempt_read*/
+/*----------------------------------------------------------------------------*/
+/*Writes to file `node` up to `len` bytes from offset from `data`*/
+error_t
+netfs_attempt_write
+	(
+	struct iouser * cred,
+	struct node * node,
+	loff_t offset,
+	size_t * len,
+	void * data
+	)
+	{
+	LOG_MSG("netfs_attempt_write");
+
+	return 0;
+	}/*netfs_attempt_write*/
+/*----------------------------------------------------------------------------*/
+/*Frees all storage associated with the node*/
+void
+netfs_node_norefs
+	(
+	struct node * np
+	)
+	{
+	/*Destroy the node*/
+	node_destroy(np);
+	}/*netfs_node_norefs*/
+/*----------------------------------------------------------------------------*/
+/*Implements file_get_translator_cntl as described in <hurd/fs.defs>
+	(according to diskfs_S_file_get_translator_cntl)*/
+kern_return_t
+netfs_S_file_get_translator_cntl
+	(
+	struct protid * user,
+	mach_port_t * cntl,
+	mach_msg_type_name_t * cntltype
+	)
+	{
+	/*If the information about the user is missing*/
+	if(!user)
+		return EOPNOTSUPP;
+		
+	error_t err = 0;
+	
+	/*Obtain the node for which we are called*/
+	node_t * np = user->po->np;
+	
+	/*Lock the node*/
+	mutex_lock(&np->lock);
+	
+	/*Check if the user is the owner of this node*/
+	err = fshelp_isowner(&np->nn_stat, user->user);
+	
+	/*If no errors have happened*/
+	if(!err)
+		/*try to fetch the control port*/
+		err = fshelp_fetch_control(&np->transbox, cntl);
+		
+	/*If no errors have occurred, but no port has been returned*/
+	if(!err && (cntl == MACH_PORT_NULL))
+		/*set the error accordingly*/
+		err = ENXIO;
+		
+	/*If no errors have occurred so far*/
+	if(!err)
+		/*set the control port type*/
+		*cntltype = MACH_MSG_TYPE_MOVE_SEND;
+		
+	/*Unlock the node*/
+	mutex_unlock(&np->lock);
+	
+	/*Return the result of operations*/
+	return err;
+	}/*netfs_S_file_get_translator_cntl*/
+/*----------------------------------------------------------------------------*/
+int
+netfs_demuxer
+	(
+	mach_msg_header_t * ing,
+	mach_msg_header_t * outp
+	);
+/*----------------------------------------------------------------------------*/
+/*Entry point*/
+int
+main
+	(
+	int argc,
+	char ** argv
+	)
+	{
+	/*Start logging*/
+	INIT_LOG();
+	LOG_MSG(">> Starting initialization...");
+
+	/*The port on which this translator will be set upon*/
+	mach_port_t bootstrap_port;
+	
+	error_t err = 0;
+	
+	/*Parse the command line arguments*/
+	argp_parse(&argp_startup, argc, argv, ARGP_IN_ORDER, 0, 0);
+	LOG_MSG("Command line arguments parsed.");
+	
+	/*Try to create the root node*/
+	err = node_create_root(&netfs_root_node);
+	if(err)
+		error(EXIT_FAILURE, err, "Failed to create the root node");
+	LOG_MSG("Root node created.");
+
+	/*Obtain the bootstrap port*/
+	task_get_bootstrap_port(mach_task_self(), &bootstrap_port);
+
+	/*Initialize the translator*/
+	netfs_init();
+
+	/*Obtain a port to the underlying node opened as O_NOTRANS*/
+	underlying_node = netfs_startup(bootstrap_port, O_READ | O_NOTRANS);
+	LOG_MSG("netfs initialization complete.");
+
+	/*Initialize the root node*/
+	err = node_init_root(underlying_node, netfs_root_node);
+	if(err)
+		error(EXIT_FAILURE, err, "Failed to initialize the root node");
+	LOG_MSG("Root node initialized.");
+	LOG_MSG("\tRoot node address: 0x%lX", (unsigned long)netfs_root_node);
+	
+	/*Map the time for updating node information*/
+	err = maptime_map(0, 0, &maptime);
+	if(err)
+		error(EXIT_FAILURE, err, "Failed to map the time");
+	LOG_MSG("Time mapped.");
+		
+	/*Obtain stat information about the underlying node*/
+	err = io_stat(underlying_node, &underlying_node_stat);
+	if(err)
+		error(EXIT_FAILURE, err,
+			"Cannot obtain stat information about the underlying node");
+	LOG_MSG("Stat information for undelying node obtained.");
+	
+	/*Obtain the ID of the current process*/
+	fsid = getpid();
+	
+	/*Setup the stat information for the root node*/
+	netfs_root_node->nn_stat = underlying_node_stat;
+
+	netfs_root_node->nn_stat.st_ino 	= FILTER_ROOT_INODE;
+	netfs_root_node->nn_stat.st_fsid	= fsid;
+	netfs_root_node->nn_stat.st_mode = underlying_node_stat.st_mode;
+		
+	netfs_root_node->nn_translated = netfs_root_node->nn_stat.st_mode;
+	
+	netfs_root_node->nn->port = target;
+	
+	/*Update the timestamps of the root node*/
+	fshelp_touch
+		(&netfs_root_node->nn_stat, TOUCH_ATIME | TOUCH_MTIME | TOUCH_CTIME,
+		maptime);
+
+	LOG_MSG(">> Initialization complete. Entering netfs server loop...");
+	
+	/*Start serving clients*/
+	for(;;)
+		netfs_server_loop();
+	}/*main*/
+/*----------------------------------------------------------------------------*/
diff --git a/filter.c~ b/filter.c~
new file mode 100644
index 000000000..bd4ad6d93
--- /dev/null
+++ b/filter.c~
@@ -0,0 +1,736 @@
+/*----------------------------------------------------------------------------*/
+/*filter.c*/
+/*----------------------------------------------------------------------------*/
+/*The filtering translator*/
+/*----------------------------------------------------------------------------*/
+/*Based on the code of unionfs translator.*/
+/*----------------------------------------------------------------------------*/
+/*Copyright (C) 2001, 2002, 2005, 2008 Free Software Foundation, Inc.
+  Written by Sergiu Ivanov <unlimitedscolobb@gmail.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; either version 2 of the
+  License, or * (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.*/
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+#define _GNU_SOURCE 1
+/*----------------------------------------------------------------------------*/
+#include "filter.h"
+/*----------------------------------------------------------------------------*/
+#include <error.h>
+#include <argp.h>
+#include <argz.h>
+#include <hurd/netfs.h>
+#include <fcntl.h>
+/*----------------------------------------------------------------------------*/
+#include "debug.h"
+#include "options.h"
+#include "trace.h"
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Global Variables----------------------------------------------------*/
+/*The name of the server*/
+char * netfs_server_name = "filter";
+/*----------------------------------------------------------------------------*/
+/*The version of the server*/
+char * netfs_server_version = "0.0";
+/*----------------------------------------------------------------------------*/
+/*The maximal length of a chain of symbolic links*/
+int netfs_maxsymlinks = 12;
+/*----------------------------------------------------------------------------*/
+/*A port to the underlying node*/
+mach_port_t underlying_node;
+/*----------------------------------------------------------------------------*/
+/*Status information for the underlying node*/
+io_statbuf_t underlying_node_stat;
+/*----------------------------------------------------------------------------*/
+/*Mapped time used for updating node information*/
+volatile struct mapped_time_value * maptime;
+/*----------------------------------------------------------------------------*/
+/*The filesystem ID*/
+pid_t fsid;
+/*----------------------------------------------------------------------------*/
+/*The port from which we will read (TODO: and write) the data*/
+mach_port_t target;
+/*----------------------------------------------------------------------------*/
+/*The file to print debug messages to*/
+FILE * filter_dbg;
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Functions-----------------------------------------------------------*/
+/*Attempts to create a file named `name` in `dir` for `user` with mode `mode`*/
+error_t
+netfs_attempt_create_file
+	(
+	struct iouser * user,
+	struct node * dir,
+	char * name,
+	mode_t mode,
+	struct node ** node
+	)
+	{
+	LOG_MSG("netfs_attempt_create_file");
+
+	/*Unlock `dir` and say that we can do nothing else here*/
+	mutex_unlock(&dir->lock);
+	return EOPNOTSUPP;
+	}/*netfs_attempt_create_file*/
+/*----------------------------------------------------------------------------*/
+/*Return an error if the process of opening a file should not be allowed
+	to complete because of insufficient permissions*/
+error_t
+netfs_check_open_permissions
+	(
+	struct iouser * user,
+	struct node * np,
+	int flags,
+	int newnode
+	)
+	{
+	LOG_MSG("netfs_check_open_permissions");
+
+	error_t err = 0;
+	
+	/*Cheks user's permissions*/
+	if(flags & O_READ)
+		err = fshelp_access(&np->nn_stat, S_IREAD, user);
+	if(!err && (flags & O_WRITE))
+		err = fshelp_access(&np->nn_stat, S_IWRITE, user);
+	if(!err && (flags & O_EXEC))
+		err = fshelp_access(&np->nn_stat, S_IEXEC, user);
+		
+	/*Return the result of the check*/
+	return err;
+	}/*netfs_check_open_permissions*/
+/*----------------------------------------------------------------------------*/
+/*Attempts an utimes call for the user `cred` on node `node`*/
+error_t
+netfs_attempt_utimes
+	(
+	struct iouser * cred,
+	struct node * node,
+	struct timespec * atime,
+	struct timespec * mtime
+	)
+	{
+	LOG_MSG("netfs_attempt_utimes");
+
+	error_t err = 0;
+	
+	/*See what information is to be updated*/
+	int flags = TOUCH_CTIME;
+	
+	/*Check if the user is indeed the owner of the node*/
+	err = fshelp_isowner(&node->nn_stat, cred);
+	
+	/*If the user is allowed to do utimes*/
+	if(!err)
+		{
+		/*If atime is to be updated*/
+		if(atime)
+			/*update the atime*/
+			node->nn_stat.st_atim = *atime;
+		else
+			/*the current time will be set as the atime*/
+			flags |= TOUCH_ATIME;
+		
+		/*If mtime is to be updated*/
+		if(mtime)
+			/*update the mtime*/
+			node->nn_stat.st_mtim = *mtime;
+		else
+			/*the current time will be set as mtime*/
+			flags |= TOUCH_MTIME;
+		
+		/*touch the file*/
+		fshelp_touch(&node->nn_stat, flags, maptime);
+		}
+	
+	/*Return the result of operations*/
+	return err;
+	}/*netfs_attempt_utimes*/
+/*----------------------------------------------------------------------------*/
+/*Returns the valid access types for file `node` and user `cred`*/
+error_t
+netfs_report_access
+	(
+	struct iouser * cred,
+	struct node * np,
+	int * types
+	)
+	{
+	LOG_MSG("netfs_report_access");
+
+	/*No access at first*/
+	*types = 0;
+	
+	/*Check the access and set the required bits*/
+	if(fshelp_access(&np->nn_stat, S_IREAD,  cred) == 0)
+		*types |= O_READ;
+	if(fshelp_access(&np->nn_stat, S_IWRITE, cred) == 0)
+		*types |= O_WRITE;
+	if(fshelp_access(&np->nn_stat, S_IEXEC,  cred) == 0)
+		*types |= O_EXEC;
+
+	/*Everything OK*/
+	return 0;
+	}/*netfs_report_access*/
+/*----------------------------------------------------------------------------*/
+/*Validates the stat data for the node*/
+error_t
+netfs_validate_stat
+	(
+	struct node * np,
+	struct iouser * cred
+	)
+	{
+	LOG_MSG("netfs_validate_stat");
+
+	error_t err = 0;
+	
+	/*Validate the stat information about the node*/
+	err = io_stat(np->nn->port, &np->nn_stat);
+
+	/*Return the result of operations*/
+	return err;
+	}/*netfs_validate_stat*/
+/*----------------------------------------------------------------------------*/
+/*Syncs `node` completely to disk*/
+error_t
+netfs_attempt_sync
+	(
+	struct iouser * cred,
+	struct node * node,
+	int wait
+	)
+	{
+	LOG_MSG("netfs_attempt_sync");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_sync*/
+/*----------------------------------------------------------------------------*/
+/*Fetches a directory*/
+error_t
+netfs_get_dirents
+	(
+	struct iouser * cred,
+	struct node * dir,
+	int first_entry,
+	int num_entries,
+	char ** data,
+	mach_msg_type_number_t * data_len,
+	vm_size_t max_data_len,
+	int * data_entries
+	)
+	{
+	LOG_MSG("netfs_get_dirents");
+	
+	/*This node is not a directory*/
+	return ENOTDIR;
+	}/*netfs_get_dirents*/
+/*----------------------------------------------------------------------------*/
+/*Looks up `name` under `dir` for `user`*/
+error_t
+netfs_attempt_lookup
+	(
+	struct iouser * user,
+	struct node * dir,
+	char * name,
+	struct node ** node
+	)
+	{
+	LOG_MSG("netfs_attempt_lookup: '%s'", name);
+		
+	/*Unlock the mutexes in `dir`*/
+	mutex_unlock(&dir->lock);
+	return EOPNOTSUPP;
+	}/*netfs_attempt_lookup*/
+/*----------------------------------------------------------------------------*/
+/*Deletes `name` in `dir` for `user`*/
+error_t
+netfs_attempt_unlink
+	(
+	struct iouser * user,
+	struct node * dir,
+	char * name
+	)
+	{
+	LOG_MSG("netfs_attempt_unlink");
+
+	return 0;
+	}/*netfs_attempt_unlink*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to rename `fromdir`/`fromname` to `todir`/`toname`*/
+error_t
+netfs_attempt_rename
+	(
+	struct iouser * user,
+	struct node * fromdir,
+	char * fromname,
+	struct node * todir,
+	char * toname,
+	int excl
+	)
+	{
+	LOG_MSG("netfs_attempt_rename");
+
+	/*Operation not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_rename*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to create a new directory*/
+error_t
+netfs_attempt_mkdir
+	(
+	struct iouser * user,
+	struct node * dir,
+	char * name,
+	mode_t mode
+	)
+	{
+	LOG_MSG("netfs_attempt_mkdir");
+
+	return 0;
+	}/*netfs_attempt_mkdir*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to remove directory `name` in `dir` for `user`*/
+error_t
+netfs_attempt_rmdir
+	(
+	struct iouser * user,
+	struct node * dir,
+	char * name
+	)
+	{
+	LOG_MSG("netfs_attempt_rmdir");
+
+	return 0;
+	}/*netfs_attempt_rmdir*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to change the mode of `node` for user `cred` to `uid`:`gid`*/
+error_t
+netfs_attempt_chown
+	(
+	struct iouser * cred,
+	struct node * node,
+	uid_t uid,
+	uid_t gid
+	)
+	{
+	LOG_MSG("netfs_attempt_chown");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_chown*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to change the author of `node` to `author`*/
+error_t
+netfs_attempt_chauthor
+	(
+	struct iouser * cred,
+	struct node * node,
+	uid_t author
+	)
+	{
+	LOG_MSG("netfs_attempt_chauthor");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_chauthor*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to change the mode of `node` to `mode` for `cred`*/
+error_t
+netfs_attempt_chmod
+	(
+	struct iouser * user,
+	struct node * node,
+	mode_t mode
+	)
+	{
+	LOG_MSG("netfs_attempt_chmod");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_chmod*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to turn `node` into a symlink targetting `name`*/
+error_t
+netfs_attempt_mksymlink
+	(
+	struct iouser * cred,
+	struct node * node,
+	char * name
+	)
+	{
+	LOG_MSG("netfs_attempt_mksymlink");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_mksymlink*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to turn `node` into a device; type can be either S_IFBLK or S_IFCHR*/
+error_t
+netfs_attempt_mkdev
+	(
+	struct iouser * cred,
+	struct node * node,
+	mode_t type,
+	dev_t indexes
+	)
+	{
+	LOG_MSG("netfs_attempt_mkdev");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_mkdev*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to set the passive translator record for `file` passing `argz`*/
+error_t
+netfs_set_translator
+	(
+	struct iouser * cred,
+	struct node * node,
+	char * argz,
+	size_t arglen
+	)
+	{
+	LOG_MSG("netfs_set_translator");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_set_translator	*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to call chflags for `node`*/
+error_t
+netfs_attempt_chflags
+	(
+	struct iouser * cred,
+	struct node * node,
+	int flags
+	)
+	{
+	LOG_MSG("netfs_attempt_chflags");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_chflags*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to set the size of file `node`*/
+error_t
+netfs_attempt_set_size
+	(
+	struct iouser * cred,
+	struct node * node,
+	loff_t size
+	)
+	{
+	LOG_MSG("netfs_attempt_set_size");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_set_size*/
+/*----------------------------------------------------------------------------*/
+/*Fetches the filesystem status information*/
+error_t
+netfs_attempt_statfs
+	(
+	struct iouser * cred,
+	struct node * node,
+	fsys_statfsbuf_t * st
+	)
+	{
+	LOG_MSG("netfs_attempt_statfs");
+
+	/*Operation is not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_statfs*/
+/*----------------------------------------------------------------------------*/
+/*Syncs the filesystem*/
+error_t
+netfs_attempt_syncfs
+	(
+	struct iouser * cred,
+	int wait
+	)
+	{
+	LOG_MSG("netfs_attempt_syncfs");
+
+	/*Everythin OK*/
+	return 0;
+	}/*netfs_attempt_syncfs*/
+/*----------------------------------------------------------------------------*/
+/*Creates a link in `dir` with `name` to `file`*/
+error_t
+netfs_attempt_link
+	(
+	struct iouser * user,
+	struct node * dir,
+	struct node * file,
+	char * name,
+	int excl
+	)
+	{
+	LOG_MSG("netfs_attempt_link");
+
+	/*Operation not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_link*/
+/*----------------------------------------------------------------------------*/
+/*Attempts to create an anonymous file related to `dir` with `mode`*/
+error_t
+netfs_attempt_mkfile
+	(
+	struct iouser * user,
+	struct node * dir,
+	mode_t mode,
+	struct node ** node
+	)
+	{
+	LOG_MSG("netfs_attempt_mkfile");
+
+	/*Unlock the directory*/
+	mutex_unlock(&dir->lock);
+
+	/*Operation not supported*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_mkfile*/
+/*----------------------------------------------------------------------------*/
+/*Reads the contents of symlink `node` into `buf`*/
+error_t
+netfs_attempt_readlink
+	(
+	struct iouser * user,
+	struct node * node,
+	char * buf
+	)
+	{
+	LOG_MSG("netfs_attempt_readlink");
+
+	/*Operation not supported (why?..)*/
+	return EOPNOTSUPP;
+	}/*netfs_attempt_readlink*/
+/*----------------------------------------------------------------------------*/
+/*Reads from file `node` up to `len` bytes from `offset` into `data`*/
+error_t
+netfs_attempt_read
+	(
+	struct iouser * cred,
+	struct node * np,
+	loff_t offset,
+	size_t * len,
+	void * data
+	)
+	{
+	LOG_MSG("netfs_attempt_read");
+
+	error_t err = 0;
+
+	/*Obtain a pointer to the first byte of the supplied buffer*/
+	char * buf = data;
+	
+	/*Try to read the requested information from the file*/
+	err = io_read(np->nn->port, &buf, len, offset, *len);
+	
+	/*If some data has been read successfully*/
+	if(!err && (buf != data))
+		{
+		/*copy the data from the buffer into which it has just been read into
+			the supplied receiver*/
+		memcpy(data, buf, *len);
+		
+		/*unmap the new buffer*/
+		munmap(buf, *len);
+		}
+
+	/*Return the result of reading*/
+	return err;
+	}/*netfs_attempt_read*/
+/*----------------------------------------------------------------------------*/
+/*Writes to file `node` up to `len` bytes from offset from `data`*/
+error_t
+netfs_attempt_write
+	(
+	struct iouser * cred,
+	struct node * node,
+	loff_t offset,
+	size_t * len,
+	void * data
+	)
+	{
+	LOG_MSG("netfs_attempt_write");
+
+	return 0;
+	}/*netfs_attempt_write*/
+/*----------------------------------------------------------------------------*/
+/*Frees all storage associated with the node*/
+void
+netfs_node_norefs
+	(
+	struct node * np
+	)
+	{
+	/*Destroy the node*/
+	node_destroy(np);
+	}/*netfs_node_norefs*/
+/*----------------------------------------------------------------------------*/
+/*Implements file_get_translator_cntl as described in <hurd/fs.defs>
+	(according to diskfs_S_file_get_translator_cntl)*/
+kern_return_t
+netfs_S_file_get_translator_cntl
+	(
+	struct protid * user,
+	mach_port_t * cntl,
+	mach_msg_type_name_t * cntltype
+	)
+	{
+	/*If the information about the user is missing*/
+	if(!user)
+		return EOPNOTSUPP;
+		
+	error_t err = 0;
+	
+	/*Obtain the node for which we are called*/
+	node_t * np = user->po->np;
+	
+	/*Lock the node*/
+	mutex_lock(&np->lock);
+	
+	/*Check if the user is the owner of this node*/
+	err = fshelp_isowner(&np->nn_stat, user->user);
+	
+	/*If no errors have happened*/
+	if(!err)
+		/*try to fetch the control port*/
+		err = fshelp_fetch_control(&np->transbox, cntl);
+		
+	/*If no errors have occurred, but no port has been returned*/
+	if(!err && (cntl == MACH_PORT_NULL))
+		/*set the error accordingly*/
+		err = ENXIO;
+		
+	/*If no errors have occurred so far*/
+	if(!err)
+		/*set the control port type*/
+		*cntltype = MACH_MSG_TYPE_MOVE_SEND;
+		
+	/*Unlock the node*/
+	mutex_unlock(&np->lock);
+	
+	/*Return the result of operations*/
+	return err;
+	}/*netfs_S_file_get_translator_cntl*/
+/*----------------------------------------------------------------------------*/
+int
+netfs_demuxer
+	(
+	mach_msg_header_t * ing,
+	mach_msg_header_t * outp
+	);
+/*----------------------------------------------------------------------------*/
+/*Entry point*/
+int
+main
+	(
+	int argc,
+	char ** argv
+	)
+	{
+	/*Start logging*/
+	INIT_LOG();
+	LOG_MSG(">> Starting initialization...");
+
+	/*The port on which this translator will be set upon*/
+	mach_port_t bootstrap_port;
+	
+	error_t err = 0;
+	
+	/*Parse the command line arguments*/
+	argp_parse(&argp_startup, argc, argv, ARGP_IN_ORDER, 0, 0);
+	LOG_MSG("Command line arguments parsed.");
+	
+	/*Try to create the root node*/
+	err = node_create_root(&netfs_root_node);
+	if(err)
+		error(EXIT_FAILURE, err, "Failed to create the root node");
+	LOG_MSG("Root node created.");
+
+	/*Obtain the bootstrap port*/
+	task_get_bootstrap_port(mach_task_self(), &bootstrap_port);
+
+	/*Initialize the translator*/
+	netfs_init();
+
+	/*Obtain a port to the underlying node opened as O_NOTRANS*/
+	underlying_node = netfs_startup(bootstrap_port, O_READ | O_NOTRANS);
+	LOG_MSG("netfs initialization complete.");
+
+	/*Initialize the root node*/
+	err = node_init_root(underlying_node, netfs_root_node);
+	if(err)
+		error(EXIT_FAILURE, err, "Failed to initialize the root node");
+	LOG_MSG("Root node initialized.");
+	LOG_MSG("\tRoot node address: 0x%lX", (unsigned long)netfs_root_node);
+	
+	/*Map the time for updating node information*/
+	err = maptime_map(0, 0, &maptime);
+	if(err)
+		error(EXIT_FAILURE, err, "Failed to map the time");
+	LOG_MSG("Time mapped.");
+		
+	/*Obtain stat information about the underlying node*/
+	err = io_stat(underlying_node, &underlying_node_stat);
+	if(err)
+		error(EXIT_FAILURE, err,
+			"Cannot obtain stat information about the underlying node");
+	LOG_MSG("Stat information for undelying node obtained.");
+	
+	/*Obtain the ID of the current process*/
+	fsid = getpid();
+	
+	/*Setup the stat information for the root node*/
+	netfs_root_node->nn_stat = underlying_node_stat;
+
+	netfs_root_node->nn_stat.st_ino 	= FILTER_ROOT_INODE;
+	netfs_root_node->nn_stat.st_fsid	= fsid;
+	netfs_root_node->nn_stat.st_mode = underlying_node_stat.st_mode;
+		
+	netfs_root_node->nn_translated = netfs_root_node->nn_stat.st_mode;
+	
+	/*Filter the translator stack under ourselves*/
+	err = trace_find(underlying_node, "/hurd/m", O_READ, &target);
+	if(err)
+		error
+			(
+			EXIT_FAILURE, err,
+			"Could not trace the translator stack on the underlying node"
+			);
+			
+	netfs_root_node->nn->port = target;
+	
+	/*Update the timestamps of the root node*/
+	fshelp_touch
+		(&netfs_root_node->nn_stat, TOUCH_ATIME | TOUCH_MTIME | TOUCH_CTIME,
+		maptime);
+
+	LOG_MSG(">> Initialization complete. Entering netfs server loop...");
+	
+	/*Start serving clients*/
+	for(;;)
+		netfs_server_loop();
+	}/*main*/
+/*----------------------------------------------------------------------------*/
diff --git a/filter.h b/filter.h
new file mode 100644
index 000000000..6dc9a69dc
--- /dev/null
+++ b/filter.h
@@ -0,0 +1,348 @@
+/*----------------------------------------------------------------------------*/
+/*filter.h*/
+/*----------------------------------------------------------------------------*/
+/*The definitions for the filtering translator*/
+/*----------------------------------------------------------------------------*/
+/*Based on the code of unionfs translator.*/
+/*----------------------------------------------------------------------------*/
+/*Copyright (C) 2001, 2002, 2005, 2008 Free Software Foundation, Inc.
+  Written by Sergiu Ivanov <unlimitedscolobb@gmail.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; either version 2 of the
+  License, or * (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.*/
+/*----------------------------------------------------------------------------*/
+#ifndef __FILTER_H__
+#define __FILTER_H__
+/*----------------------------------------------------------------------------*/
+#include <stddef.h>
+#include <stdlib.h>
+#include <cthreads.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/time.h>
+#include <hurd/ihash.h>
+#include <hurd/iohelp.h>
+/*----------------------------------------------------------------------------*/
+#include "node.h"
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Macros--------------------------------------------------------------*/
+/*The inode for the root node*/
+#define FILTER_ROOT_INODE 1
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Global Variables----------------------------------------------------*/
+/*A mapped time value*/
+/*Required for a very fast access to time*/
+extern volatile struct mapped_time_value * maptime;
+/*----------------------------------------------------------------------------*/
+/*A port to the underlying node*/
+extern mach_port_t underlying_node;
+/*----------------------------------------------------------------------------*/
+/*The stat information about the underlying node*/
+extern io_statbuf_t underlying_node_stat;
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Functions-----------------------------------------------------------*/
+/*Attempts to create a file named `name` in `dir` for `user` with mode `mode`*/
+error_t
+netfs_attempt_create_file
+	(
+	struct iouser * user,
+	struct node * dir,
+	char * name,
+	mode_t mode,
+	struct node ** node
+	);
+/*----------------------------------------------------------------------------*/
+/*Returns an error if the process of opening a file should not be allowed
+	to complete because of insufficient permissions*/
+error_t
+netfs_check_open_permissions
+	(
+	struct iouser * user,
+	struct node * np,
+	int flags,
+	int newnode
+	);
+/*----------------------------------------------------------------------------*/
+/*Attempts an utimes call for the user `cred` on node `node`*/
+error_t
+netfs_attempt_utimes
+	(
+	struct iouser * cred,
+	struct node * node,
+	struct timespec * atime,
+	struct timespec * mtime
+	);
+/*----------------------------------------------------------------------------*/
+/*Returns the valid access types for file `node` and user `cred`*/
+error_t
+netfs_report_access
+	(
+	struct iouser * cred,
+	struct node * np,
+	int * types
+	);
+/*----------------------------------------------------------------------------*/
+/*Validates the stat data for the node*/
+error_t
+netfs_validate_stat
+	(
+	struct node * np,
+	struct iouser * cred
+	);
+/*----------------------------------------------------------------------------*/
+/*Syncs `node` completely to disk*/
+error_t
+netfs_attempt_sync
+	(
+	struct iouser * cred,
+	struct node * node,
+	int wait
+	);
+/*----------------------------------------------------------------------------*/
+/*Fetches a directory*/
+error_t
+netfs_get_dirents
+	(
+	struct iouser * cred,
+	struct node * dir,
+	int first_entry,
+	int num_entries,
+	char ** data,
+	mach_msg_type_number_t * data_len,
+	vm_size_t max_data_len,
+	int * data_entries
+	);
+/*----------------------------------------------------------------------------*/
+/*Looks up `name` under `dir` for `user`*/
+error_t
+netfs_attempt_lookup
+	(
+	struct iouser * user,
+	struct node * dir,
+	char * name,
+	struct node ** node
+	);
+/*----------------------------------------------------------------------------*/
+/*Deletes `name` in `dir` for `user`*/
+error_t
+netfs_attempt_unlink
+	(
+	struct iouser * user,
+	struct node * dir,
+	char * name
+	);
+/*----------------------------------------------------------------------------*/
+/*Attempts to rename `fromdir`/`fromname` to `todir`/`toname`*/
+error_t
+netfs_attempt_rename
+	(
+	struct iouser * user,
+	struct node * fromdir,
+	char * fromname,
+	struct node * todir,
+	char * toname,
+	int excl
+	);
+/*----------------------------------------------------------------------------*/
+/*Attempts to create a new directory*/
+error_t
+netfs_attempt_mkdir
+	(
+	struct iouser * user,
+	struct node * dir,
+	char * name,
+	mode_t mode
+	);
+/*----------------------------------------------------------------------------*/
+/*Attempts to remove directory `name` in `dir` for `user`*/
+error_t
+netfs_attempt_rmdir
+	(
+	struct iouser * user,
+	struct node * dir,
+	char * name
+	);
+/*----------------------------------------------------------------------------*/
+/*Attempts to change the owner of `node` for user `cred` to `uid`:`gid`*/
+error_t
+netfs_attempt_chown
+	(
+	struct iouser * cred,
+	struct node * node,
+	uid_t uid,
+	uid_t gid
+	);
+/*----------------------------------------------------------------------------*/
+/*Attempts to change the author of `node` to `author`*/
+error_t
+netfs_attempt_chauthor
+	(
+	struct iouser * cred,
+	struct node * node,
+	uid_t author
+	);
+/*----------------------------------------------------------------------------*/
+/*Attempts to change the mode of `node` to `mode` for `cred`*/
+error_t
+netfs_attempt_chmod
+	(
+	struct iouser * user,
+	struct node * node,
+	mode_t mode
+	);
+/*----------------------------------------------------------------------------*/
+/*Attempts to turn `node` into a symlink targetting `name`*/
+error_t
+netfs_attempt_mksymlink
+	(
+	struct iouser * cred,
+	struct node * node,
+	char * name
+	);
+/*----------------------------------------------------------------------------*/
+/*Attempts to turn `node` into a device; type can be either S_IFBLK or S_IFCHR*/
+error_t
+netfs_attempt_mkdev
+	(
+	struct iouser * cred,
+	struct node * node,
+	mode_t type,
+	dev_t indexes
+	);
+/*----------------------------------------------------------------------------*/
+/*Attempts to set the passive translator record for `file` passing `argz`*/
+error_t
+netfs_set_translator
+	(
+	struct iouser * cred,
+	struct node * node,
+	char * argz,
+	size_t arglen
+	);
+/*----------------------------------------------------------------------------*/
+/*Attempts to call chflags for `node`*/
+error_t
+netfs_attempt_chflags
+	(
+	struct iouser * cred,
+	struct node * node,
+	int flags
+	);
+/*----------------------------------------------------------------------------*/
+/*Attempts to set the size of file `node`*/
+error_t
+netfs_attempt_set_size
+	(
+	struct iouser * cred,
+	struct node * node,
+	loff_t size
+	);
+/*----------------------------------------------------------------------------*/
+/*Fetches the filesystem status information*/
+error_t
+netfs_attempt_statfs
+	(
+	struct iouser * cred,
+	struct node * node,
+	fsys_statfsbuf_t * st
+	);
+/*----------------------------------------------------------------------------*/
+/*Syncs the filesystem*/
+error_t
+netfs_attempt_syncfs
+	(
+	struct iouser * cred,
+	int wait
+	);
+/*----------------------------------------------------------------------------*/
+/*Creates a link in `dir` with `name` to `file`*/
+error_t
+netfs_attempt_link
+	(
+	struct iouser * user,
+	struct node * dir,
+	struct node * file,
+	char * name,
+	int excl
+	);
+/*----------------------------------------------------------------------------*/
+/*Attempts to create an anonymous file related to `dir` with `mode`*/
+error_t
+netfs_attempt_mkfile
+	(
+	struct iouser * user,
+	struct node * dir,
+	mode_t mode,
+	struct node ** node
+	);
+/*----------------------------------------------------------------------------*/
+/*Reads the contents of symlink `node` into `buf`*/
+error_t
+netfs_attempt_readlink
+	(
+	struct iouser * user,
+	struct node * node,
+	char * buf
+	);
+/*----------------------------------------------------------------------------*/
+/*Reads from file `node` up to `len` bytes from `offset` into `data`*/
+error_t
+netfs_attempt_read
+	(
+	struct iouser * cred,
+	struct node * np,
+	loff_t offset,
+	size_t * len,
+	void * data
+	);
+/*----------------------------------------------------------------------------*/
+/*Writes to file `node` up to `len` bytes from offset from `data`*/
+error_t
+netfs_attempt_write
+	(
+	struct iouser * cred,
+	struct node * node,
+	loff_t offset,
+	size_t * len,
+	void * data
+	);
+/*----------------------------------------------------------------------------*/
+/*Frees all storage associated with the node*/
+void
+netfs_node_norefs
+	(
+	struct node * np
+	);
+/*----------------------------------------------------------------------------*/
+/*Implements file_get_translator_cntl as described in <hurd/fs.defs>
+	(according to diskfs_S_file_get_translator_cntl)*/
+kern_return_t
+netfs_S_file_get_translator_cntl
+	(
+	struct protid * user,
+	mach_port_t * cntl,
+	mach_msg_type_name_t * cntltype
+	);
+/*----------------------------------------------------------------------------*/
+#endif /*__FILTER_H__*/
diff --git a/node.c b/node.c
new file mode 100644
index 000000000..33ff2777e
--- /dev/null
+++ b/node.c
@@ -0,0 +1,166 @@
+/*----------------------------------------------------------------------------*/
+/*node.c*/
+/*----------------------------------------------------------------------------*/
+/*Implementation of node management strategies*/
+/*----------------------------------------------------------------------------*/
+/*Based on the code of unionfs translator.*/
+/*----------------------------------------------------------------------------*/
+/*Copyright (C) 2001, 2002, 2005, 2008 Free Software Foundation, Inc.
+  Written by Sergiu Ivanov <unlimitedscolobb@gmail.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; either version 2 of the
+  License, or * (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.*/
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+#define _GNU_SOURCE 1
+/*----------------------------------------------------------------------------*/
+#include <stdlib.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <stdio.h>
+/*----------------------------------------------------------------------------*/
+#include "debug.h"
+#include "node.h"
+#include "filter.h"
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Global Variables----------------------------------------------------*/
+/*The lock protecting the underlying filesystem*/
+struct mutex ulfs_lock = MUTEX_INITIALIZER;
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Functions-----------------------------------------------------------*/
+/*Derives a new node from `lnode` and adds a reference to `lnode`*/
+error_t
+node_create
+	(
+	node_t ** node	/*store the result here*/
+	)
+	{
+	error_t err = 0;
+
+	/*Create a new netnode*/
+	netnode_t * netnode_new = malloc(sizeof(netnode_t));
+	
+	/*If the memory could not be allocated*/
+	if(netnode_new == NULL)
+		err = ENOMEM;
+	else
+		{
+		/*create a new node from the netnode*/
+		node_t * node_new = netfs_make_node(netnode_new);
+		
+		/*If the creation failed*/
+		if(node_new == NULL)
+			{
+			/*set the error code*/
+			err = ENOMEM;
+
+			/*destroy the netnode created above*/
+			free(netnode_new);
+			
+			/*stop*/
+			return err;
+			}
+		
+		/*store the result of creation in the second parameter*/
+		*node = node_new;
+		}
+		
+	/*Return the result of operations*/
+	return err;
+	}/*node_create*/
+/*----------------------------------------------------------------------------*/
+/*Destroys the specified node and removes a light reference from the
+	associated light node*/
+void
+node_destroy
+	(
+	node_t * np
+	)
+	{
+	/*Destroy the port to the underlying filesystem allocated to the node*/
+	PORT_DEALLOC(np->nn->port);
+	
+	/*Free the netnode and the node itself*/
+	free(np->nn);
+	free(np);
+	}/*node_destroy*/
+/*----------------------------------------------------------------------------*/
+/*Creates the root node and the corresponding lnode*/
+error_t
+node_create_root
+	(
+	node_t ** root_node	/*store the result here*/
+	)
+	{
+	error_t err;
+
+	/*Try to create a node*/
+	node_t * node;
+	err = node_create(&node);
+	if(err)
+		return err;
+		
+	/*Store the result in the parameter*/
+	*root_node = node;
+	
+	/*Return the result*/
+	return err;
+	}/*node_create_root*/
+/*----------------------------------------------------------------------------*/
+/*Initializes the port to the underlying filesystem for the root node*/
+error_t
+node_init_root
+	(
+	mach_port_t underlying,	/*the port to the underlying node*/
+	node_t * node						/*the root node*/
+	)
+	{
+	error_t err = 0;
+
+	/*Acquire a lock for operations on the underlying filesystem*/
+	mutex_lock(&ulfs_lock);
+	
+	/*Store the specified port in the node*/
+	node->nn->port = underlying;
+	
+	LOG_MSG("node_init_root: Port: 0x%ld", (unsigned long)node->nn->port);
+	
+	/*Stat the root node*/
+	err = io_stat(node->nn->port, &node->nn_stat);
+	if(err)
+		{
+		/*deallocate the port*/
+		PORT_DEALLOC(node->nn->port);
+		
+		LOG_MSG("node_init_root: Could not stat the root node.");
+		
+		/*unlock the mutex and exit*/
+		mutex_unlock(&ulfs_lock);
+		return err;
+		}
+
+	/*Release the lock for operations on the undelying filesystem*/
+	mutex_unlock(&ulfs_lock);
+	
+	/*Return the result of operations*/
+	return err;
+	}/*node_init_root*/
+/*----------------------------------------------------------------------------*/
diff --git a/node.h b/node.h
new file mode 100644
index 000000000..c8c8945c7
--- /dev/null
+++ b/node.h
@@ -0,0 +1,114 @@
+/*----------------------------------------------------------------------------*/
+/*node.h*/
+/*----------------------------------------------------------------------------*/
+/*Node management. Also see lnode.h*/
+/*----------------------------------------------------------------------------*/
+/*Based on the code of unionfs translator.*/
+/*----------------------------------------------------------------------------*/
+/*Copyright (C) 2001, 2002, 2005, 2008 Free Software Foundation, Inc.
+  Written by Sergiu Ivanov <unlimitedscolobb@gmail.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; either version 2 of the
+  License, or * (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.*/
+/*----------------------------------------------------------------------------*/
+#ifndef __NODE_H__
+#define __NODE_H__
+
+/*----------------------------------------------------------------------------*/
+#include <error.h>
+#include <sys/stat.h>
+#include <hurd/netfs.h>
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Macros--------------------------------------------------------------*/
+/*Checks whether the give node is the root of the filterfs filesystem*/
+#define NODE_IS_ROOT(n) (((n)->nn->lnode->dir) ? (0) : (1))
+/*----------------------------------------------------------------------------*/
+/*Node flags*/
+#define FLAG_NODE_ULFS_FIXED 		0x00000001	/*this node should not be updated*/
+#define FLAG_NODE_INVALIDATE		0x00000002 	/*this node must be updated*/
+#define FLAG_NODE_ULFS_UPTODATE	0x00000004 	/*this node has just been updated*/
+/*----------------------------------------------------------------------------*/
+/*The type of offset corresponding to the current platform*/
+#ifdef __USE_FILE_OFFSET64
+#	define OFFSET_T __off64_t
+#else
+#	define OFFSET_T __off_t
+#endif /*__USE_FILE_OFFSET64*/
+/*----------------------------------------------------------------------------*/
+/*The size of a chunk of a string (for a small optimization in checking
+	the property)*/
+#define STRING_CHUNK 256
+/*----------------------------------------------------------------------------*/
+/*Deallocates the specified port*/
+#define PORT_DEALLOC(p) (mach_port_deallocate(mach_task_self(), (p)))
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*The user-defined node for libnetfs*/
+struct netnode
+	{
+	/*the flags associated with this node (might be not required)*/
+	int flags;
+
+	/*a port to the underlying filesystem*/
+	file_t port;
+	};/*struct netnode*/
+/*----------------------------------------------------------------------------*/
+typedef struct netnode netnode_t;
+/*----------------------------------------------------------------------------*/
+typedef struct node node_t;
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Global Variables----------------------------------------------------*/
+/*The lock protecting the underlying filesystem*/
+extern struct mutex ulfs_lock;
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Functions-----------------------------------------------------------*/
+/*Derives a new node from `lnode` and adds a reference to `lnode`*/
+error_t
+node_create
+	(
+	node_t ** node	/*store the result here*/
+	);
+/*----------------------------------------------------------------------------*/
+/*Destroys the specified node and removes a light reference from the
+	associated light node*/
+void
+node_destroy
+	(
+	node_t * np
+	);
+/*----------------------------------------------------------------------------*/
+/*Creates the root node and the corresponding lnode*/
+error_t
+node_create_root
+	(
+	node_t ** root_node	/*store the result here*/
+	);
+/*----------------------------------------------------------------------------*/
+/*Initializes the port to the underlying filesystem for the root node*/
+error_t
+node_init_root
+	(
+	mach_port_t underlying,	/*the port to the underlying node*/
+	node_t * node						/*the root node*/
+	);
+/*----------------------------------------------------------------------------*/
+#endif /*__NODE_H__*/
diff --git a/options.c b/options.c
new file mode 100644
index 000000000..736a8589a
--- /dev/null
+++ b/options.c
@@ -0,0 +1,190 @@
+/*----------------------------------------------------------------------------*/
+/*options.h*/
+/*----------------------------------------------------------------------------*/
+/*Definitions for parsing the command line switches*/
+/*----------------------------------------------------------------------------*/
+/*Based on the code of unionfs translator.*/
+/*----------------------------------------------------------------------------*/
+/*Copyright (C) 2001, 2002, 2005, 2008 Free Software Foundation, Inc.
+  Written by Sergiu Ivanov <unlimitedscolobb@gmail.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; either version 2 of the
+  License, or * (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.*/
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+#define _GNU_SOURCE 1
+/*----------------------------------------------------------------------------*/
+#include <argp.h>
+#include <error.h>
+/*----------------------------------------------------------------------------*/
+#include "debug.h"
+#include "options.h"
+#include "node.h"
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Macros--------------------------------------------------------------*/
+/*Short documentation for argp*/
+#define ARGS_DOC	""
+#define DOC 			"Filters the translator stack of the node it is set upon."
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Forward Declarations------------------------------------------------*/
+/*Argp parser function for the common options*/
+static
+error_t
+argp_parse_common_options
+	(
+	int key,
+	char * arg,
+	struct argp_state * state
+	);
+/*----------------------------------------------------------------------------*/
+/*Argp parser function for the startup options*/
+static
+error_t
+argp_parse_startup_options
+	(
+	int key,
+	char * arg,
+	struct argp_state * state
+	);
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Global Variables----------------------------------------------------*/
+/*This variable is set to a non-zero value after the parsing of starup options
+	is finished*/
+static int parsing_startup_options_finished;
+/*----------------------------------------------------------------------------*/
+/*Argp options common to both the runtime and the startup parser*/
+static const struct argp_option argp_common_options[] =
+	{
+	{0}
+	};
+/*----------------------------------------------------------------------------*/
+/*Argp options only meaningful for startupp parsing*/
+static const struct argp_option argp_startup_options[] =
+	{
+	{0}
+	};
+/*----------------------------------------------------------------------------*/
+/*Argp parser for only the common options*/
+static const struct argp argp_parser_common_options =
+	{argp_common_options, argp_parse_common_options, 0, 0, 0};
+/*----------------------------------------------------------------------------*/
+/*Argp parser for only the startup options*/
+static const struct argp argp_parser_startup_options =
+	{argp_startup_options, argp_parse_startup_options, 0, 0, 0};
+/*----------------------------------------------------------------------------*/
+/*The list of children parsers for runtime arguments*/
+static const struct argp_child argp_children_runtime[] =
+	{
+	{&argp_parser_common_options},
+	{&netfs_std_runtime_argp},
+	{0}
+	};
+/*----------------------------------------------------------------------------*/
+/*The list of children parsers for startup arguments*/
+static const struct argp_child argp_children_startup[] =
+	{
+	{&argp_parser_startup_options},
+	{&argp_parser_common_options},
+	{&netfs_std_startup_argp},
+	{0}
+	};
+/*----------------------------------------------------------------------------*/
+/*The version of the server for argp*/
+const char * argp_program_version = "0.0";
+/*----------------------------------------------------------------------------*/
+/*The arpg parser for runtime arguments*/
+struct argp argp_runtime =
+	{0, 0, 0, 0, argp_children_runtime};
+/*----------------------------------------------------------------------------*/
+/*The argp parser for startup arguments*/
+struct argp argp_startup =
+	{0, 0, ARGS_DOC, DOC, argp_children_startup};
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Functions-----------------------------------------------------------*/
+/*Argp parser function for the common options*/
+static
+error_t
+argp_parse_common_options
+	(
+	int key,
+	char * arg,
+	struct argp_state * state
+	)
+	{
+	error_t err = 0;
+	
+	/*Go through the possible options*/
+	switch(key)
+		{
+		case ARGP_KEY_END:
+			{
+			/*If parsing of startup options has not finished*/
+			if(!parsing_startup_options_finished)
+				{
+				/*set the flag that the startup options have already been parsed*/
+				parsing_startup_options_finished = 1;
+				}
+			else
+				{
+/*TODO: Take care of runtime calls modifying the property*/
+				}
+			}
+		/*If the option could not be recognized*/
+		default:
+			{
+			/*set the error code*/
+			err = ARGP_ERR_UNKNOWN;
+			}
+		}
+		
+	/*Return the result*/
+	return err;
+	}/*argp_parse_common_options*/
+/*----------------------------------------------------------------------------*/
+/*Argp parser function for the startup options*/
+static
+error_t
+argp_parse_startup_options
+	(
+	int key,
+	char * arg,
+	struct argp_state * state
+	)
+	{
+	/*Do nothing in a beautiful way*/
+	error_t err = 0;
+	
+	switch(key)
+		{
+		default:
+			{
+			err = ARGP_ERR_UNKNOWN;
+			
+			break;
+			}
+		}
+	
+	return err;
+	}/*argp_parse_startup_options*/
+/*----------------------------------------------------------------------------*/
diff --git a/options.h b/options.h
new file mode 100644
index 000000000..1db2f655f
--- /dev/null
+++ b/options.h
@@ -0,0 +1,44 @@
+/*----------------------------------------------------------------------------*/
+/*options.h*/
+/*----------------------------------------------------------------------------*/
+/*Declarations for parsing the command line switches*/
+/*----------------------------------------------------------------------------*/
+/*Based on the code of unionfs translator.*/
+/*----------------------------------------------------------------------------*/
+/*Copyright (C) 2001, 2002, 2005, 2008 Free Software Foundation, Inc.
+  Written by Sergiu Ivanov <unlimitedscolobb@gmail.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; either version 2 of the
+  License, or * (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.*/
+/*----------------------------------------------------------------------------*/
+#ifndef __OPTIONS_H__
+#define __OPTIONS_H__
+
+/*----------------------------------------------------------------------------*/
+/*--------Macros--------------------------------------------------------------*/
+/*Makes a long option out of option name*/
+#define OPT_LONG(o) "--"o
+/*----------------------------------------------------------------------------*/
+/*----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------*/
+/*--------Global Variables----------------------------------------------------*/
+/*The argp parser for startup arguments*/
+extern struct argp argp_startup;
+/*----------------------------------------------------------------------------*/
+/*The argp parser for rutime arguments*/
+extern struct argp argp_runtime;
+/*----------------------------------------------------------------------------*/
+#endif /*__OPTIONS_H__*/