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).

1 files changed, 348 insertions, 0 deletions

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__*/