get_pathname.c revision 31dbecd482405e0d3a67eb58e1a1c8cb9f2ad83e 
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 Public
8 * License.
9 * %End-Header%
10 *
11 * 	ext2fs_get_pathname(fs, dir, ino, name)
12 *
13 * 	This function translates takes two inode numbers into a
14 * 	string, placing the result in <name>.  <dir> is the containing
15 * 	directory inode, and <ino> is the inode number itself.  If
16 * 	<ino> is zero, then ext2fs_get_pathname will return pathname
17 * 	of the the directory <dir>.
18 *
19 */
20
21#include <stdio.h>
22#include <string.h>
23#if HAVE_UNISTD_H
24#include <unistd.h>
25#endif
26
27#if EXT2_FLAT_INCLUDES
28#include "ext2_fs.h"
29#else
30#include <linux/ext2_fs.h>
31#endif
32
33#include "ext2fs.h"
34
35struct get_pathname_struct {
36	ext2_ino_t	search_ino;
37	ext2_ino_t	parent;
38	char		*name;
39	errcode_t	errcode;
40};
41
42#ifdef __TURBOC__
43 #pragma argsused
44#endif
45static int get_pathname_proc(struct ext2_dir_entry *dirent,
46			     int	offset,
47			     int	blocksize,
48			     char	*buf,
49			     void	*priv_data)
50{
51	struct get_pathname_struct	*gp;
52	errcode_t			retval;
53
54	gp = (struct get_pathname_struct *) priv_data;
55
56	if (((dirent->name_len & 0xFF) == 2) &&
57	    !strncmp(dirent->name, "..", 2))
58		gp->parent = dirent->inode;
59	if (dirent->inode == gp->search_ino) {
60		retval = ext2fs_get_mem((dirent->name_len & 0xFF) + 1,
61					(void **) &gp->name);
62		if (retval) {
63			gp->errcode = retval;
64			return DIRENT_ABORT;
65		}
66		strncpy(gp->name, dirent->name, (dirent->name_len & 0xFF));
67		gp->name[dirent->name_len & 0xFF] = '\0';
68		return DIRENT_ABORT;
69	}
70	return 0;
71}
72
73static errcode_t ext2fs_get_pathname_int(ext2_filsys fs, ext2_ino_t dir,
74					 ext2_ino_t ino, int maxdepth,
75					 char *buf, char **name)
76{
77	struct get_pathname_struct gp;
78	char	*parent_name, *ret;
79	errcode_t	retval;
80
81	if (dir == ino) {
82		retval = ext2fs_get_mem(2, (void **)name);
83		if (retval)
84			return retval;
85		strcpy(*name, (dir == EXT2_ROOT_INO) ? "/" : ".");
86		return 0;
87	}
88
89	if (!dir || (maxdepth < 0)) {
90		retval = ext2fs_get_mem(4, (void **)name);
91		if (retval)
92			return retval;
93		strcpy(*name, "...");
94		return 0;
95	}
96
97	gp.search_ino = ino;
98	gp.parent = 0;
99	gp.name = 0;
100	gp.errcode = 0;
101
102	retval = ext2fs_dir_iterate(fs, dir, 0, buf, get_pathname_proc, &gp);
103	if (retval)
104		goto cleanup;
105	if (gp.errcode) {
106		retval = gp.errcode;
107		goto cleanup;
108	}
109
110	retval = ext2fs_get_pathname_int(fs, gp.parent, dir, maxdepth-1,
111					 buf, &parent_name);
112	if (retval)
113		goto cleanup;
114	if (!ino) {
115		*name = parent_name;
116		return 0;
117	}
118
119	if (gp.name)
120		retval = ext2fs_get_mem(strlen(parent_name)+strlen(gp.name)+2,
121					(void **) &ret);
122	else
123		retval = ext2fs_get_mem(strlen(parent_name)+5,
124					(void **) &ret);
125	if (retval)
126		goto cleanup;
127
128	ret[0] = 0;
129	if (parent_name[1])
130		strcat(ret, parent_name);
131	strcat(ret, "/");
132	if (gp.name)
133		strcat(ret, gp.name);
134	else
135		strcat(ret, "???");
136	*name = ret;
137	ext2fs_free_mem((void **) &parent_name);
138	retval = 0;
139
140cleanup:
141	if (gp.name)
142		ext2fs_free_mem((void **) &gp.name);
143	return retval;
144}
145
146errcode_t ext2fs_get_pathname(ext2_filsys fs, ext2_ino_t dir, ext2_ino_t ino,
147			      char **name)
148{
149	char	*buf;
150	errcode_t	retval;
151
152	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
153
154	retval = ext2fs_get_mem(fs->blocksize, (void **) &buf);
155	if (retval)
156		return retval;
157	if (dir == ino)
158		ino = 0;
159	retval = ext2fs_get_pathname_int(fs, dir, ino, 32, buf, name);
160	ext2fs_free_mem((void **) &buf);
161	return retval;
162
163}
164