busybox/e2fsprogs/ext2fs/get_pathname.c

/*
 * get_pathname.c --- do directry/inode -> name translation
 *
 * Copyright (C) 1993, 1994, 1995 Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU Public
 * License.
 * %End-Header%
 *
 *	ext2fs_get_pathname(fs, dir, ino, name)
 *
 *	This function translates takes two inode numbers into a
 *	string, placing the result in <name>.  <dir> is the containing
 *	directory inode, and <ino> is the inode number itself.  If
 *	<ino> is zero, then ext2fs_get_pathname will return pathname
 *	of the the directory <dir>.
 *
 */

#include <stdio.h>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif

#include "ext2_fs.h"
#include "ext2fs.h"

struct get_pathname_struct {
	ext2_ino_t	search_ino;
	ext2_ino_t	parent;
	char		*name;
	errcode_t	errcode;
};

#ifdef __TURBOC__
# pragma argsused
#endif
static int get_pathname_proc(struct ext2_dir_entry *dirent,
			     int	offset EXT2FS_ATTR((unused)),
			     int	blocksize EXT2FS_ATTR((unused)),
			     char	*buf EXT2FS_ATTR((unused)),
			     void	*priv_data)
{
	struct get_pathname_struct	*gp;
	errcode_t			retval;

	gp = (struct get_pathname_struct *) priv_data;

	if (((dirent->name_len & 0xFF) == 2) &&
	    !strncmp(dirent->name, "..", 2))
		gp->parent = dirent->inode;
	if (dirent->inode == gp->search_ino) {
		retval = ext2fs_get_mem((dirent->name_len & 0xFF) + 1,
					&gp->name);
		if (retval) {
			gp->errcode = retval;
			return DIRENT_ABORT;
		}
		strncpy(gp->name, dirent->name, (dirent->name_len & 0xFF));
		gp->name[dirent->name_len & 0xFF] = '\0';
		return DIRENT_ABORT;
	}
	return 0;
}

static errcode_t ext2fs_get_pathname_int(ext2_filsys fs, ext2_ino_t dir,
					 ext2_ino_t ino, int maxdepth,
					 char *buf, char **name)
{
	struct get_pathname_struct gp;
	char	*parent_name, *ret;
	errcode_t	retval;

	if (dir == ino) {
		retval = ext2fs_get_mem(2, name);
		if (retval)
			return retval;
		strcpy(*name, (dir == EXT2_ROOT_INO) ? "/" : ".");
		return 0;
	}

	if (!dir || (maxdepth < 0)) {
		retval = ext2fs_get_mem(4, name);
		if (retval)
			return retval;
		strcpy(*name, "...");
		return 0;
	}

	gp.search_ino = ino;
	gp.parent = 0;
	gp.name = 0;
	gp.errcode = 0;

	retval = ext2fs_dir_iterate(fs, dir, 0, buf, get_pathname_proc, &gp);
	if (retval)
		goto cleanup;
	if (gp.errcode) {
		retval = gp.errcode;
		goto cleanup;
	}

	retval = ext2fs_get_pathname_int(fs, gp.parent, dir, maxdepth-1,
					 buf, &parent_name);
	if (retval)
		goto cleanup;
	if (!ino) {
		*name = parent_name;
		return 0;
	}

	if (gp.name)
		retval = ext2fs_get_mem(strlen(parent_name)+strlen(gp.name)+2,
					&ret);
	else
		retval = ext2fs_get_mem(strlen(parent_name)+5, &ret);
	if (retval)
		goto cleanup;

	ret[0] = 0;
	if (parent_name[1])
		strcat(ret, parent_name);
	strcat(ret, "/");
	if (gp.name)
		strcat(ret, gp.name);
	else
		strcat(ret, "???");
	*name = ret;
	ext2fs_free_mem(&parent_name);
	retval = 0;

cleanup:
	ext2fs_free_mem(&gp.name);
	return retval;
}

errcode_t ext2fs_get_pathname(ext2_filsys fs, ext2_ino_t dir, ext2_ino_t ino,
			      char **name)
{
	char	*buf;
	errcode_t	retval;

	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);

	retval = ext2fs_get_mem(fs->blocksize, &buf);
	if (retval)
		return retval;
	if (dir == ino)
		ino = 0;
	retval = ext2fs_get_pathname_int(fs, dir, ino, 32, buf, name);
	ext2fs_free_mem(&buf);
	return retval;

}