1/* vi: set sw=4 ts=4: */
2/*
3 * Utility routines.
4 *
5 * Copyright (C) tons of folks.  Tracking down who wrote what
6 * isn't something I'm going to worry about...  If you wrote something
7 * here, please feel free to acknowledge your work.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 *
23 * Based in part on code from sash, Copyright (c) 1999 by David I. Bell
24 * Permission has been granted to redistribute this code under the GPL.
25 *
26 */
27
28#include <stdio.h>
29#include <errno.h>
30#include <fcntl.h>
31#include <string.h>
32#include <unistd.h>
33#include <sys/ioctl.h>
34#include "libbb.h"
35#include "loop.h" /* Pull in loop device support */
36
37extern int del_loop(const char *device)
38{
39	int fd;
40
41	if ((fd = open(device, O_RDONLY)) < 0) {
42		perror_msg("%s", device);
43		return (FALSE);
44	}
45	if (ioctl(fd, LOOP_CLR_FD, 0) < 0) {
46		perror_msg("ioctl: LOOP_CLR_FD");
47		return (FALSE);
48	}
49	close(fd);
50	return (TRUE);
51}
52
53extern int set_loop(const char *device, const char *file, int offset,
54					int *loopro)
55{
56	struct loop_info loopinfo;
57	int fd, ffd, mode;
58
59	mode = *loopro ? O_RDONLY : O_RDWR;
60	if ((ffd = open(file, mode)) < 0 && !*loopro
61		&& (errno != EROFS || (ffd = open(file, mode = O_RDONLY)) < 0)) {
62		perror_msg("%s", file);
63		return 1;
64	}
65	if ((fd = open(device, mode)) < 0) {
66		close(ffd);
67		perror_msg("%s", device);
68		return 1;
69	}
70	*loopro = (mode == O_RDONLY);
71
72	memset(&loopinfo, 0, sizeof(loopinfo));
73	safe_strncpy(loopinfo.lo_name, file, LO_NAME_SIZE);
74
75	loopinfo.lo_offset = offset;
76
77	loopinfo.lo_encrypt_key_size = 0;
78	if (ioctl(fd, LOOP_SET_FD, ffd) < 0) {
79		perror_msg("ioctl: LOOP_SET_FD");
80		close(fd);
81		close(ffd);
82		return 1;
83	}
84	if (ioctl(fd, LOOP_SET_STATUS, &loopinfo) < 0) {
85		(void) ioctl(fd, LOOP_CLR_FD, 0);
86		perror_msg("ioctl: LOOP_SET_STATUS");
87		close(fd);
88		close(ffd);
89		return 1;
90	}
91	close(fd);
92	close(ffd);
93	return 0;
94}
95
96extern char *find_unused_loop_device(void)
97{
98	char dev[20];
99	int i, fd;
100	struct stat statbuf;
101	struct loop_info loopinfo;
102
103	for (i = 0; i <= 7; i++) {
104		sprintf(dev, "/dev/loop%d", i);
105		if (stat(dev, &statbuf) == 0 && S_ISBLK(statbuf.st_mode)) {
106			if ((fd = open(dev, O_RDONLY)) >= 0) {
107				if (ioctl(fd, LOOP_GET_STATUS, &loopinfo) != 0) {
108					if (errno == ENXIO) {	/* probably free */
109						close(fd);
110						return strdup(dev);
111					}
112				}
113				close(fd);
114			}
115		}
116	}
117	return NULL;
118}
119
120
121/* END CODE */
122/*
123Local Variables:
124c-file-style: "linux"
125c-basic-offset: 4
126tab-width: 4
127End:
128*/
129