get_pathname.c revision a6ce1349539f866334ef3d5758bc2ee44a454acd 
1/*
2 * get_pathname.c --- do directry/inode -> name translation
3 *
4 * Copyright (C) 1993, 1994, 1995 Theodore Ts'o.
5 *
6 * %Begin-Header%
7 * This file may be redistributed under the terms of the GNU Library
8 * General Public License, version 2.
9 * %End-Header%
10 */
11
12/*
13 *
14 * 	ext2fs_get_pathname(fs, dir, ino, name)
15 *
16 * 	This function translates takes two inode numbers into a
17 * 	string, placing the result in <name>.  <dir> is the containing
18 * 	directory inode, and <ino> is the inode number itself.  If
19 * 	<ino> is zero, then ext2fs_get_pathname will return pathname
20 * 	of the the directory <dir>.
21 *
22 */
23
24#include <stdio.h>
25#include <string.h>
26#if HAVE_UNISTD_H
27#include <unistd.h>
28#endif
29
30#include "ext2_fs.h"
31#include "ext2fs.h"
32
33struct get_pathname_struct {
34	ext2_ino_t	search_ino;
35	ext2_ino_t	parent;
36	char		*name;
37	errcode_t	errcode;
38};
39
40#ifdef __TURBOC__
41 #pragma argsused
42#endif
43static int get_pathname_proc(struct ext2_dir_entry *dirent,
44			     int	offset EXT2FS_ATTR((unused)),
45			     int	blocksize EXT2FS_ATTR((unused)),
46			     char	*buf EXT2FS_ATTR((unused)),
47			     void	*priv_data)
48{
49	struct get_pathname_struct	*gp;
50	errcode_t			retval;
51
52	gp = (struct get_pathname_struct *) priv_data;
53
54	if (((dirent->name_len & 0xFF) == 2) &&
55	    !strncmp(dirent->name, "..", 2))
56		gp->parent = dirent->inode;
57	if (dirent->inode == gp->search_ino) {
58		retval = ext2fs_get_mem((dirent->name_len & 0xFF) + 1,
59					&gp->name);
60		if (retval) {
61			gp->errcode = retval;
62			return DIRENT_ABORT;
63		}
64		strncpy(gp->name, dirent->name, (dirent->name_len & 0xFF));
65		gp->name[dirent->name_len & 0xFF] = '\0';
66		return DIRENT_ABORT;
67	}
68	return 0;
69}
70
71static errcode_t ext2fs_get_pathname_int(ext2_filsys fs, ext2_ino_t dir,
72					 ext2_ino_t ino, int maxdepth,
73					 char *buf, char **name)
74{
75	struct get_pathname_struct gp;
76	char	*parent_name, *ret;
77	errcode_t	retval;
78
79	if (dir == ino) {
80		retval = ext2fs_get_mem(2, name);
81		if (retval)
82			return retval;
83		strcpy(*name, (dir == EXT2_ROOT_INO) ? "/" : ".");
84		return 0;
85	}
86
87	if (!dir || (maxdepth < 0)) {
88		retval = ext2fs_get_mem(4, name);
89		if (retval)
90			return retval;
91		strcpy(*name, "...");
92		return 0;
93	}
94
95	gp.search_ino = ino;
96	gp.parent = 0;
97	gp.name = 0;
98	gp.errcode = 0;
99
100	retval = ext2fs_dir_iterate(fs, dir, 0, buf, get_pathname_proc, &gp);
101	if (retval)
102		goto cleanup;
103	if (gp.errcode) {
104		retval = gp.errcode;
105		goto cleanup;
106	}
107
108	retval = ext2fs_get_pathname_int(fs, gp.parent, dir, maxdepth-1,
109					 buf, &parent_name);
110	if (retval)
111		goto cleanup;
112	if (!ino) {
113		*name = parent_name;
114		return 0;
115	}
116
117	if (gp.name)
118		retval = ext2fs_get_mem(strlen(parent_name)+strlen(gp.name)+2,
119					&ret);
120	else
121		retval = ext2fs_get_mem(strlen(parent_name)+5, &ret);
122	if (retval)
123		goto cleanup;
124
125	ret[0] = 0;
126	if (parent_name[1])
127		strcat(ret, parent_name);
128	strcat(ret, "/");
129	if (gp.name)
130		strcat(ret, gp.name);
131	else
132		strcat(ret, "???");
133	*name = ret;
134	ext2fs_free_mem(&parent_name);
135	retval = 0;
136
137cleanup:
138	if (gp.name)
139		ext2fs_free_mem(&gp.name);
140	return retval;
141}
142
143errcode_t ext2fs_get_pathname(ext2_filsys fs, ext2_ino_t dir, ext2_ino_t ino,
144			      char **name)
145{
146	char	*buf;
147	errcode_t	retval;
148
149	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
150
151	retval = ext2fs_get_mem(fs->blocksize, &buf);
152	if (retval)
153		return retval;
154	if (dir == ino)
155		ino = 0;
156	retval = ext2fs_get_pathname_int(fs, dir, ino, 32, buf, name);
157	ext2fs_free_mem(&buf);
158	return retval;
159
160}
161