1/* vi: set sw=4 ts=4: */
2/*
3 * Utility routines.
4 *
5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8 */
9
10#include "libbb.h"
11#include <mntent.h>
12
13/*
14 * Given a block device, find the mount table entry if that block device
15 * is mounted.
16 *
17 * Given any other file (or directory), find the mount table entry for its
18 * filesystem.
19 */
20struct mntent *find_mount_point(const char *name, const char *table)
21{
22	struct stat s;
23	dev_t mountDevice;
24	FILE *mountTable;
25	struct mntent *mountEntry;
26
27	if (stat(name, &s) != 0)
28		return 0;
29
30	if ((s.st_mode & S_IFMT) == S_IFBLK)
31		mountDevice = s.st_rdev;
32	else
33		mountDevice = s.st_dev;
34
35
36	mountTable = setmntent(table ? table : bb_path_mtab_file, "r");
37	if (!mountTable)
38		return 0;
39
40	while ((mountEntry = getmntent(mountTable)) != 0) {
41		if (strcmp(name, mountEntry->mnt_dir) == 0
42		 || strcmp(name, mountEntry->mnt_fsname) == 0
43		) { /* String match. */
44			break;
45		}
46		if (stat(mountEntry->mnt_fsname, &s) == 0 && s.st_rdev == mountDevice)	/* Match the device. */
47			break;
48		if (stat(mountEntry->mnt_dir, &s) == 0 && s.st_dev == mountDevice)	/* Match the directory's mount point. */
49			break;
50	}
51	endmntent(mountTable);
52	return mountEntry;
53}
54