usr/utils/losetup.c

/* Originally from Ted's losetup.c */

#define LOOPMAJOR	7

/*
 * losetup.c - setup and control loop devices
 */

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/sysmacros.h>
#include <stdarg.h>
#include <string.h>

#include "loop.h"

extern int verbose;
extern char *progname;
extern char *xstrdup (const char *s);	/* not: #include "sundries.h" */
extern void error (const char *fmt, ...);	/* idem */

/* caller guarantees n > 0 */
void xstrncpy(char *dest, const char *src, size_t n)
{
	strncpy(dest, src, n-1);
	dest[n-1] = 0;
}


static int loop_info64_to_old(const struct loop_info64 *info64, struct loop_info *info)
{
	memset(info, 0, sizeof(*info));
	info->lo_number = info64->lo_number;
	info->lo_device = info64->lo_device;
	info->lo_inode = info64->lo_inode;
	info->lo_rdevice = info64->lo_rdevice;
	info->lo_offset = info64->lo_offset;
	info->lo_encrypt_type = info64->lo_encrypt_type;
	info->lo_encrypt_key_size = info64->lo_encrypt_key_size;
	info->lo_flags = info64->lo_flags;
	info->lo_init[0] = info64->lo_init[0];
	info->lo_init[1] = info64->lo_init[1];
	if (info->lo_encrypt_type == LO_CRYPT_CRYPTOAPI)
		memcpy(info->lo_name, info64->lo_crypt_name, LO_NAME_SIZE);
	else
		memcpy(info->lo_name, info64->lo_file_name, LO_NAME_SIZE);
	memcpy(info->lo_encrypt_key, info64->lo_encrypt_key, LO_KEY_SIZE);

	/* error in case values were truncated */
	if (info->lo_device != info64->lo_device ||
			info->lo_rdevice != info64->lo_rdevice ||
			info->lo_inode != info64->lo_inode ||
			info->lo_offset != info64->lo_offset)
		return -EOVERFLOW;

	return 0;
}


static int show_loop(char *device)
{
	struct loop_info loopinfo;
	struct loop_info64 loopinfo64;
	int fd, errsv;

	if ((fd = open(device, O_RDONLY)) < 0) {
		int errsv = errno;
		fprintf(stderr, "loop: can't open device %s: %s\n",
			device, strerror (errsv));
		return 2;
	}

	if (ioctl(fd, LOOP_GET_STATUS64, &loopinfo64) == 0) {

		loopinfo64.lo_file_name[LO_NAME_SIZE-2] = '*';
		loopinfo64.lo_file_name[LO_NAME_SIZE-1] = 0;
		loopinfo64.lo_crypt_name[LO_NAME_SIZE-1] = 0;

		printf("%s: [%04llx]:%llu (%s)",
		       device, loopinfo64.lo_device, loopinfo64.lo_inode,
		       loopinfo64.lo_file_name);

		if (loopinfo64.lo_offset)
			printf(", offset %lld", loopinfo64.lo_offset);

		if (loopinfo64.lo_sizelimit)
			printf(", sizelimit %lld", loopinfo64.lo_sizelimit);

		if (loopinfo64.lo_encrypt_type ||
		    loopinfo64.lo_crypt_name[0]) {
			char *e = loopinfo64.lo_crypt_name;

			if (*e == 0 && loopinfo64.lo_encrypt_type == 1)
				e = "XOR";
			printf(", encryption %s (type %d)",
			       e, loopinfo64.lo_encrypt_type);
		}
		printf("\n");
		close (fd);
		return 0;
	}

	if (ioctl(fd, LOOP_GET_STATUS, &loopinfo) == 0) {
		printf ("%s: [%04x]:%ld (%s)",
			device, loopinfo.lo_device, loopinfo.lo_inode,
			loopinfo.lo_name);

		if (loopinfo.lo_offset)
			printf(", offset %d", loopinfo.lo_offset);

		if (loopinfo.lo_encrypt_type)
			printf(", encryption type %d\n",
			       loopinfo.lo_encrypt_type);

		printf("\n");
		close (fd);
		return 0;
	}

	errsv = errno;
	fprintf(stderr, "loop: can't get info on device %s: %s\n",
		device, strerror (errsv));
	close (fd);
	return 1;
}

int
is_loop_device (const char *device) {
	struct stat statbuf;

	return (stat(device, &statbuf) == 0 &&
		S_ISBLK(statbuf.st_mode) &&
		major(statbuf.st_rdev) == LOOPMAJOR);
}

#define SIZE(a) (sizeof(a)/sizeof(a[0]))

char * find_unused_loop_device (void)
{
	/* Just creating a device, say in /tmp, is probably a bad idea -
	   people might have problems with backup or so.
	   So, we just try /dev/loop[0-7]. */
	char dev[20];
	char *loop_formats[] = { "/dev/loop%d", "/dev/loop/%d" };
	int i, j, fd, somedev = 0, someloop = 0, permission = 0;
	struct stat statbuf;
	struct loop_info loopinfo;

	for (j = 0; j < SIZE(loop_formats); j++) {
		for(i = 0; i < 256; i++) {
			sprintf(dev, loop_formats[j], i);
			if (stat (dev, &statbuf) == 0 && S_ISBLK(statbuf.st_mode)) {
				somedev++;
				fd = open (dev, O_RDONLY);
				if (fd >= 0) {
					if(ioctl (fd, LOOP_GET_STATUS, &loopinfo) == 0)
						someloop++;		/* in use */
					else if (errno == ENXIO) {
						close (fd);
						return xstrdup(dev);/* probably free */
					}
					close (fd);
				} else if (errno == EACCES)
					permission++;

				continue;/* continue trying as long as devices exist */
			}
			break;
		}
	}

	if (!somedev)
		error("%s: could not find any device /dev/loop#", progname);
	else if (!someloop && permission)
		error("%s: no permission to look at /dev/loop#", progname);
	else if (!someloop)
		error(
		    "%s: Could not find any loop device. Maybe this kernel "
		    "does not know\n"
		    "       about the loop device? (If so, recompile or "
		    "`modprobe loop'.)", progname);
	else
		error("%s: could not find any free loop device", progname);
	return 0;
}

/*
 * A function to read the passphrase either from the terminal or from
 * an open file descriptor.
 */
static char * xgetpass(int pfd, const char *prompt)
{
	char *pass;
	int buflen, i;

	pass = NULL;
	buflen = 0;
	for (i=0; ; i++) {
		if (i >= buflen-1) {
				/* we're running out of space in the buffer.
				 * Make it bigger: */
			char *tmppass = pass;
			buflen += 128;
			pass = realloc(tmppass, buflen);
			if (pass == NULL) {
				/* realloc failed. Stop reading. */
				error("Out of memory while reading passphrase");
				pass = tmppass; /* the old buffer hasn't changed */
				break;
			}
		}
		if (read(pfd, pass+i, 1) != 1 ||
		    pass[i] == '\n' || pass[i] == 0)
			break;
	}

	if (pass == NULL)
		return "";

	pass[i] = 0;
	return pass;
}

static int digits_only(const char *s)
{
	while (*s)
		if (!isdigit(*s++))
			return 0;
	return 1;
}

int set_loop(const char *device, const char *file, unsigned long long offset,
	 const char *encryption, int pfd, int *loopro) {
	struct loop_info64 loopinfo64;
	int fd, ffd, mode, i;
	char *pass;

	mode = (*loopro ? O_RDONLY : O_RDWR);
	if ((ffd = open(file, mode)) < 0) {
		if (!*loopro && errno == EROFS)
			ffd = open(file, mode = O_RDONLY);
		if (ffd < 0) {
			perror(file);
			return 1;
		}
	}
	if ((fd = open(device, mode)) < 0) {
		perror (device);
		return 1;
	}
	*loopro = (mode == O_RDONLY);

	memset(&loopinfo64, 0, sizeof(loopinfo64));

	xstrncpy(loopinfo64.lo_file_name, file, LO_NAME_SIZE);

	if (encryption && *encryption) {
		if (digits_only(encryption)) {
			loopinfo64.lo_encrypt_type = atoi(encryption);
		} else {
			loopinfo64.lo_encrypt_type = LO_CRYPT_CRYPTOAPI;
			snprintf(loopinfo64.lo_crypt_name, LO_NAME_SIZE,
				 "%s", encryption);
		}
	}

	loopinfo64.lo_offset = offset;


	switch (loopinfo64.lo_encrypt_type) {
	case LO_CRYPT_NONE:
		loopinfo64.lo_encrypt_key_size = 0;
		break;
	case LO_CRYPT_XOR:
		pass = xgetpass(pfd, "Password: ");
		goto gotpass;
	default:
		pass = xgetpass(pfd, "Password: ");
	gotpass:
		memset(loopinfo64.lo_encrypt_key, 0, LO_KEY_SIZE);
		xstrncpy(loopinfo64.lo_encrypt_key, pass, LO_KEY_SIZE);
		memset(pass, 0, strlen(pass));
		loopinfo64.lo_encrypt_key_size = LO_KEY_SIZE;
	}

	if (ioctl(fd, LOOP_SET_FD, (void *)(size_t)ffd) < 0) {
		perror("ioctl: LOOP_SET_FD");
		return 1;
	}
	close (ffd);

	i = ioctl(fd, LOOP_SET_STATUS64, &loopinfo64);
	if (i) {
		struct loop_info loopinfo;
		int errsv = errno;

		i = loop_info64_to_old(&loopinfo64, &loopinfo);
		if (i) {
			errno = errsv;
			perror("ioctl: LOOP_SET_STATUS64");
		} else {
			i = ioctl(fd, LOOP_SET_STATUS, &loopinfo);
			if (i)
				perror("ioctl: LOOP_SET_STATUS");
		}
		memset(&loopinfo, 0, sizeof(loopinfo));
	}
	memset(&loopinfo64, 0, sizeof(loopinfo64));

	if (i) {
		ioctl (fd, LOOP_CLR_FD, 0);
		close (fd);
		return 1;
	}
	close (fd);

	if (verbose > 1)
		printf("set_loop(%s,%s,%llu): success\n",
		       device, file, offset);
	return 0;
}

int del_loop (const char *device)
{
	int fd;

	if ((fd = open (device, O_RDONLY)) < 0) {
		int errsv = errno;
		fprintf(stderr, "loop: can't delete device %s: %s\n",
			device, strerror (errsv));
		return 1;
	}
	if (ioctl (fd, LOOP_CLR_FD, 0) < 0) {
		perror ("ioctl: LOOP_CLR_FD");
		close (fd);
		return 1;
	}
	close (fd);
	if (verbose > 1)
		printf("del_loop(%s): success\n", device);
	return 0;
}


int verbose = 0;
char *progname;

static void usage(void) {
	fprintf(stderr, "usage:\n\
  %s loop_device                                       # give info\n\
  %s -d loop_device                                    # delete\n\
  %s -f                                                # find unused\n\
  %s [-e encryption] [-o offset] {-f|loop_device} file # setup\n",
		progname, progname, progname, progname);
	exit(1);
}

char * xstrdup (const char *s) {
	char *t;

	if (s == NULL)
		return NULL;

	t = strdup (s);

	if (t == NULL) {
		fprintf(stderr, "not enough memory");
		exit(1);
	}

	return t;
}

void error (const char *fmt, ...)
{
	va_list args;

	va_start (args, fmt);
	vfprintf (stderr, fmt, args);
	va_end (args);
	fprintf (stderr, "\n");
}

int main(int argc, char **argv)
{
	char *p, *offset, *encryption, *passfd, *device, *file;
	int delete, find, c;
	int res = 0;
	int ro = 0;
	int pfd = -1;
	unsigned long long off;


	delete = find = 0;
	off = 0;
	offset = encryption = passfd = NULL;

	progname = argv[0];
	if ((p = strrchr(progname, '/')) != NULL)
		progname = p+1;

	while ((c = getopt(argc, argv, "de:E:fo:p:v")) != -1) {
		switch (c) {
		case 'd':
			delete = 1;
			break;
		case 'E':
		case 'e':
			encryption = optarg;
			break;
		case 'f':
			find = 1;
			break;
		case 'o':
			offset = optarg;
			break;
		case 'p':
			passfd = optarg;
			break;
		case 'v':
			verbose = 1;
			break;
		default:
			usage();
		}
	}

	if (argc == 1) {
		usage();
	} else if (delete) {
		if (argc != optind+1 || encryption || offset || find)
			usage();
	} else if (find) {
		if (argc < optind || argc > optind+1)
			usage();
	} else {
		if (argc < optind+1 || argc > optind+2)
			usage();
	}

	if (find) {
		device = find_unused_loop_device();
		if (device == NULL)
			return -1;
		if (verbose)
			printf("Loop device is %s\n", device);
		if (argc == optind) {
			printf("%s\n", device);
			return 0;
		}
		file = argv[optind];
	} else {
		device = argv[optind];
		if (argc == optind+1)
			file = NULL;
		else
			file = argv[optind+1];
	}

	if (delete)
		res = del_loop(device);
	else if (file == NULL)
		res = show_loop(device);
	else {
		if (offset && sscanf(offset, "%llu", &off) != 1)
			usage();
		if (passfd && sscanf(passfd, "%d", &pfd) != 1)
			usage();
		res = set_loop(device, file, off, encryption, pfd, &ro);
	}
	return res;
}
1	/* Originally from Ted's losetup.c */
2
3	#define LOOPMAJOR 7
4
5	/*
6	* losetup.c - setup and control loop devices
7	*/
8
9	#include <stdio.h>
10	#include <string.h>
11	#include <ctype.h>
12	#include <fcntl.h>
13	#include <errno.h>
14	#include <stdlib.h>
15	#include <unistd.h>
16	#include <sys/ioctl.h>
17	#include <sys/stat.h>
18	#include <sys/mman.h>
19	#include <sys/sysmacros.h>
20	#include <stdarg.h>
21	#include <string.h>
22
23	#include "loop.h"
24
25	extern int verbose;
26	extern char *progname;
27	extern char xstrdup (const char s); /* not: #include "sundries.h" */
28	extern void error (const char fmt, ...); / idem */
29
30	/* caller guarantees n > 0 */
31	void xstrncpy(char dest, const char src, size_t n)
32	{
33	strncpy(dest, src, n-1);
34	dest[n-1] = 0;
35	}
36
37
38	static int loop_info64_to_old(const struct loop_info64 info64, struct loop_info info)
39	{
40	memset(info, 0, sizeof(*info));
41	info->lo_number = info64->lo_number;
42	info->lo_device = info64->lo_device;
43	info->lo_inode = info64->lo_inode;
44	info->lo_rdevice = info64->lo_rdevice;
45	info->lo_offset = info64->lo_offset;
46	info->lo_encrypt_type = info64->lo_encrypt_type;
47	info->lo_encrypt_key_size = info64->lo_encrypt_key_size;
48	info->lo_flags = info64->lo_flags;
49	info->lo_init[0] = info64->lo_init[0];
50	info->lo_init[1] = info64->lo_init[1];
51	if (info->lo_encrypt_type == LO_CRYPT_CRYPTOAPI)
52	memcpy(info->lo_name, info64->lo_crypt_name, LO_NAME_SIZE);
53	else
54	memcpy(info->lo_name, info64->lo_file_name, LO_NAME_SIZE);
55	memcpy(info->lo_encrypt_key, info64->lo_encrypt_key, LO_KEY_SIZE);
56
57	/* error in case values were truncated */
58	if (info->lo_device != info64->lo_device \|\|
59	info->lo_rdevice != info64->lo_rdevice \|\|
60	info->lo_inode != info64->lo_inode \|\|
61	info->lo_offset != info64->lo_offset)
62	return -EOVERFLOW;
63
64	return 0;
65	}
66
67
68	static int show_loop(char *device)
69	{
70	struct loop_info loopinfo;
71	struct loop_info64 loopinfo64;
72	int fd, errsv;
73
74	if ((fd = open(device, O_RDONLY)) < 0) {
75	int errsv = errno;
76	fprintf(stderr, "loop: can't open device %s: %s\n",
77	device, strerror (errsv));
78	return 2;
79	}
80
81	if (ioctl(fd, LOOP_GET_STATUS64, &loopinfo64) == 0) {
82
83	loopinfo64.lo_file_name[LO_NAME_SIZE-2] = '*';
84	loopinfo64.lo_file_name[LO_NAME_SIZE-1] = 0;
85	loopinfo64.lo_crypt_name[LO_NAME_SIZE-1] = 0;
86
87	printf("%s: [%04llx]:%llu (%s)",
88	device, loopinfo64.lo_device, loopinfo64.lo_inode,
89	loopinfo64.lo_file_name);
90
91	if (loopinfo64.lo_offset)
92	printf(", offset %lld", loopinfo64.lo_offset);
93
94	if (loopinfo64.lo_sizelimit)
95	printf(", sizelimit %lld", loopinfo64.lo_sizelimit);
96
97	if (loopinfo64.lo_encrypt_type \|\|
98	loopinfo64.lo_crypt_name[0]) {
99	char *e = loopinfo64.lo_crypt_name;
100
101	if (*e == 0 && loopinfo64.lo_encrypt_type == 1)
102	e = "XOR";
103	printf(", encryption %s (type %d)",
104	e, loopinfo64.lo_encrypt_type);
105	}
106	printf("\n");
107	close (fd);
108	return 0;
109	}
110
111	if (ioctl(fd, LOOP_GET_STATUS, &loopinfo) == 0) {
112	printf ("%s: [%04x]:%ld (%s)",
113	device, loopinfo.lo_device, loopinfo.lo_inode,
114	loopinfo.lo_name);
115
116	if (loopinfo.lo_offset)
117	printf(", offset %d", loopinfo.lo_offset);
118
119	if (loopinfo.lo_encrypt_type)
120	printf(", encryption type %d\n",
121	loopinfo.lo_encrypt_type);
122
123	printf("\n");
124	close (fd);
125	return 0;
126	}
127
128	errsv = errno;
129	fprintf(stderr, "loop: can't get info on device %s: %s\n",
130	device, strerror (errsv));
131	close (fd);
132	return 1;
133	}
134
135	int
136	is_loop_device (const char *device) {
137	struct stat statbuf;
138
139	return (stat(device, &statbuf) == 0 &&
140	S_ISBLK(statbuf.st_mode) &&
141	major(statbuf.st_rdev) == LOOPMAJOR);
142	}
143
144	#define SIZE(a) (sizeof(a)/sizeof(a[0]))
145
146	char * find_unused_loop_device (void)
147	{
148	/* Just creating a device, say in /tmp, is probably a bad idea -
149	people might have problems with backup or so.
150	So, we just try /dev/loop[0-7]. */
151	char dev[20];
152	char *loop_formats[] = { "/dev/loop%d", "/dev/loop/%d" };
153	int i, j, fd, somedev = 0, someloop = 0, permission = 0;
154	struct stat statbuf;
155	struct loop_info loopinfo;
156
157	for (j = 0; j < SIZE(loop_formats); j++) {
158	for(i = 0; i < 256; i++) {
159	sprintf(dev, loop_formats[j], i);
160	if (stat (dev, &statbuf) == 0 && S_ISBLK(statbuf.st_mode)) {
161	somedev++;
162	fd = open (dev, O_RDONLY);
163	if (fd >= 0) {
164	if(ioctl (fd, LOOP_GET_STATUS, &loopinfo) == 0)
165	someloop++; /* in use */
166	else if (errno == ENXIO) {
167	close (fd);
168	return xstrdup(dev);/* probably free */
169	}
170	close (fd);
171	} else if (errno == EACCES)
172	permission++;
173
174	continue;/* continue trying as long as devices exist */
175	}
176	break;
177	}
178	}
179
180	if (!somedev)
181	error("%s: could not find any device /dev/loop#", progname);
182	else if (!someloop && permission)
183	error("%s: no permission to look at /dev/loop#", progname);
184	else if (!someloop)
185	error(
186	"%s: Could not find any loop device. Maybe this kernel "
187	"does not know\n"
188	" about the loop device? (If so, recompile or "
189	"`modprobe loop'.)", progname);
190	else
191	error("%s: could not find any free loop device", progname);
192	return 0;
193	}
194
195	/*
196	* A function to read the passphrase either from the terminal or from
197	* an open file descriptor.
198	*/
199	static char * xgetpass(int pfd, const char *prompt)
200	{
201	char *pass;
202	int buflen, i;
203
204	pass = NULL;
205	buflen = 0;
206	for (i=0; ; i++) {
207	if (i >= buflen-1) {
208	/* we're running out of space in the buffer.
209	* Make it bigger: */
210	char *tmppass = pass;
211	buflen += 128;
212	pass = realloc(tmppass, buflen);
213	if (pass == NULL) {
214	/* realloc failed. Stop reading. */
215	error("Out of memory while reading passphrase");
216	pass = tmppass; /* the old buffer hasn't changed */
217	break;
218	}
219	}
220	if (read(pfd, pass+i, 1) != 1 \|\|
221	pass[i] == '\n' \|\| pass[i] == 0)
222	break;
223	}
224
225	if (pass == NULL)
226	return "";
227
228	pass[i] = 0;
229	return pass;
230	}
231
232	static int digits_only(const char *s)
233	{
234	while (*s)
235	if (!isdigit(*s++))
236	return 0;
237	return 1;
238	}
239
240	int set_loop(const char device, const char file, unsigned long long offset,
241	const char encryption, int pfd, int loopro) {
242	struct loop_info64 loopinfo64;
243	int fd, ffd, mode, i;
244	char *pass;
245
246	mode = (*loopro ? O_RDONLY : O_RDWR);
247	if ((ffd = open(file, mode)) < 0) {
248	if (!*loopro && errno == EROFS)
249	ffd = open(file, mode = O_RDONLY);
250	if (ffd < 0) {
251	perror(file);
252	return 1;
253	}
254	}
255	if ((fd = open(device, mode)) < 0) {
256	perror (device);
257	return 1;
258	}
259	*loopro = (mode == O_RDONLY);
260
261	memset(&loopinfo64, 0, sizeof(loopinfo64));
262
263	xstrncpy(loopinfo64.lo_file_name, file, LO_NAME_SIZE);
264
265	if (encryption && *encryption) {
266	if (digits_only(encryption)) {
267	loopinfo64.lo_encrypt_type = atoi(encryption);
268	} else {
269	loopinfo64.lo_encrypt_type = LO_CRYPT_CRYPTOAPI;
270	snprintf(loopinfo64.lo_crypt_name, LO_NAME_SIZE,
271	"%s", encryption);
272	}
273	}
274
275	loopinfo64.lo_offset = offset;
276
277
278	switch (loopinfo64.lo_encrypt_type) {
279	case LO_CRYPT_NONE:
280	loopinfo64.lo_encrypt_key_size = 0;
281	break;
282	case LO_CRYPT_XOR:
283	pass = xgetpass(pfd, "Password: ");
284	goto gotpass;
285	default:
286	pass = xgetpass(pfd, "Password: ");
287	gotpass:
288	memset(loopinfo64.lo_encrypt_key, 0, LO_KEY_SIZE);
289	xstrncpy(loopinfo64.lo_encrypt_key, pass, LO_KEY_SIZE);
290	memset(pass, 0, strlen(pass));
291	loopinfo64.lo_encrypt_key_size = LO_KEY_SIZE;
292	}
293
294	if (ioctl(fd, LOOP_SET_FD, (void *)(size_t)ffd) < 0) {
295	perror("ioctl: LOOP_SET_FD");
296	return 1;
297	}
298	close (ffd);
299
300	i = ioctl(fd, LOOP_SET_STATUS64, &loopinfo64);
301	if (i) {
302	struct loop_info loopinfo;
303	int errsv = errno;
304
305	i = loop_info64_to_old(&loopinfo64, &loopinfo);
306	if (i) {
307	errno = errsv;
308	perror("ioctl: LOOP_SET_STATUS64");
309	} else {
310	i = ioctl(fd, LOOP_SET_STATUS, &loopinfo);
311	if (i)
312	perror("ioctl: LOOP_SET_STATUS");
313	}
314	memset(&loopinfo, 0, sizeof(loopinfo));
315	}
316	memset(&loopinfo64, 0, sizeof(loopinfo64));
317
318	if (i) {
319	ioctl (fd, LOOP_CLR_FD, 0);
320	close (fd);
321	return 1;
322	}
323	close (fd);
324
325	if (verbose > 1)
326	printf("set_loop(%s,%s,%llu): success\n",
327	device, file, offset);
328	return 0;
329	}
330
331	int del_loop (const char *device)
332	{
333	int fd;
334
335	if ((fd = open (device, O_RDONLY)) < 0) {
336	int errsv = errno;
337	fprintf(stderr, "loop: can't delete device %s: %s\n",
338	device, strerror (errsv));
339	return 1;
340	}
341	if (ioctl (fd, LOOP_CLR_FD, 0) < 0) {
342	perror ("ioctl: LOOP_CLR_FD");
343	close (fd);
344	return 1;
345	}
346	close (fd);
347	if (verbose > 1)
348	printf("del_loop(%s): success\n", device);
349	return 0;
350	}
351
352
353	int verbose = 0;
354	char *progname;
355
356	static void usage(void) {
357	fprintf(stderr, "usage:\n\
358	%s loop_device # give info\n\
359	%s -d loop_device # delete\n\
360	%s -f # find unused\n\
361	%s [-e encryption] [-o offset] {-f\|loop_device} file # setup\n",
362	progname, progname, progname, progname);
363	exit(1);
364	}
365
366	char * xstrdup (const char *s) {
367	char *t;
368
369	if (s == NULL)
370	return NULL;
371
372	t = strdup (s);
373
374	if (t == NULL) {
375	fprintf(stderr, "not enough memory");
376	exit(1);
377	}
378
379	return t;
380	}
381
382	void error (const char *fmt, ...)
383	{
384	va_list args;
385
386	va_start (args, fmt);
387	vfprintf (stderr, fmt, args);
388	va_end (args);
389	fprintf (stderr, "\n");
390	}
391
392	int main(int argc, char **argv)
393	{
394	char p, offset, encryption, passfd, device, file;
395	int delete, find, c;
396	int res = 0;
397	int ro = 0;
398	int pfd = -1;
399	unsigned long long off;
400
401
402	delete = find = 0;
403	off = 0;
404	offset = encryption = passfd = NULL;
405
406	progname = argv[0];
407	if ((p = strrchr(progname, '/')) != NULL)
408	progname = p+1;
409
410	while ((c = getopt(argc, argv, "de:E:fo:p:v")) != -1) {
411	switch (c) {
412	case 'd':
413	delete = 1;
414	break;
415	case 'E':
416	case 'e':
417	encryption = optarg;
418	break;
419	case 'f':
420	find = 1;
421	break;
422	case 'o':
423	offset = optarg;
424	break;
425	case 'p':
426	passfd = optarg;
427	break;
428	case 'v':
429	verbose = 1;
430	break;
431	default:
432	usage();
433	}
434	}
435
436	if (argc == 1) {
437	usage();
438	} else if (delete) {
439	if (argc != optind+1 \|\| encryption \|\| offset \|\| find)
440	usage();
441	} else if (find) {
442	if (argc < optind \|\| argc > optind+1)
443	usage();
444	} else {
445	if (argc < optind+1 \|\| argc > optind+2)
446	usage();
447	}
448
449	if (find) {
450	device = find_unused_loop_device();
451	if (device == NULL)
452	return -1;
453	if (verbose)
454	printf("Loop device is %s\n", device);
455	if (argc == optind) {
456	printf("%s\n", device);
457	return 0;
458	}
459	file = argv[optind];
460	} else {
461	device = argv[optind];
462	if (argc == optind+1)
463	file = NULL;
464	else
465	file = argv[optind+1];
466	}
467
468	if (delete)
469	res = del_loop(device);
470	else if (file == NULL)
471	res = show_loop(device);
472	else {
473	if (offset && sscanf(offset, "%llu", &off) != 1)
474	usage();
475	if (passfd && sscanf(passfd, "%d", &pfd) != 1)
476	usage();
477	res = set_loop(device, file, off, encryption, pfd, &ro);
478	}
479	return res;
480	}