1/*
2 * vol_id - read filesystem label and uuid
3 *
4 * Copyright (C) 2005-2006 Kay Sievers <kay.sievers@vrfy.org>
5 *
6 *	This program is free software; you can redistribute it and/or modify it
7 *	under the terms of the GNU General Public License as published by the
8 *	Free Software Foundation version 2 of the License.
9 *
10 *	This program is distributed in the hope that it will be useful, but
11 *	WITHOUT ANY WARRANTY; without even the implied warranty of
12 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 *	General Public License for more details.
14 *
15 *	You should have received a copy of the GNU General Public License along
16 *	with this program; if not, write to the Free Software Foundation, Inc.,
17 *	675 Mass Ave, Cambridge, MA 02139, USA.
18 *
19 */
20
21#ifndef _GNU_SOURCE
22#define _GNU_SOURCE 1
23#endif
24
25#include <stdio.h>
26#include <stdlib.h>
27#include <unistd.h>
28#include <string.h>
29#include <ctype.h>
30#include <errno.h>
31#include <pwd.h>
32#include <grp.h>
33#include <getopt.h>
34#include <fcntl.h>
35#include <sys/ioctl.h>
36
37#include "../../udev.h"
38#include "lib/libvolume_id.h"
39
40#define BLKGETSIZE64 _IOR(0x12,114,size_t)
41
42#ifdef USE_LOG
43void log_message(int priority, const char *format, ...)
44{
45	va_list args;
46	static int udev_log = -1;
47
48	if (udev_log == -1) {
49		const char *value;
50
51		value = getenv("UDEV_LOG");
52		if (value)
53			udev_log = log_priority(value);
54		else
55			udev_log = LOG_ERR;
56	}
57
58	if (priority > udev_log)
59		return;
60
61	va_start(args, format);
62	vsyslog(priority, format, args);
63	va_end(args);
64}
65#endif
66
67static void vid_log(int priority, const char *file, int line, const char *format, ...)
68{
69#ifdef USE_LOG
70	char log_str[1024];
71	va_list args;
72
73	va_start(args, format);
74	vsnprintf(log_str, sizeof(log_str), format, args);
75	log_str[sizeof(log_str)-1] = '\0';
76	log_message(priority, "%s:%i %s", file, line, log_str);
77	va_end(args);
78#endif
79	return;
80}
81
82static void set_str(char *to, const char *from, size_t count)
83{
84	size_t i, j, len;
85
86	/* strip trailing whitespace */
87	len = strnlen(from, count);
88	while (len && isspace(from[len-1]))
89		len--;
90
91	/* strip leading whitespace */
92	i = 0;
93	while (isspace(from[i]) && (i < len))
94		i++;
95
96	j = 0;
97	while (i < len) {
98		/* substitute multiple whitespace */
99		if (isspace(from[i])) {
100			while (isspace(from[i]))
101				i++;
102			to[j++] = '_';
103		}
104		/* skip chars */
105		if (from[i] == '/') {
106			i++;
107			continue;
108		}
109		to[j++] = from[i++];
110	}
111	to[j] = '\0';
112}
113
114static int all_probers(volume_id_probe_fn_t probe_fn,
115		       struct volume_id *id, uint64_t off, uint64_t size,
116		       void *data)
117{
118	const char *type;
119
120	if (probe_fn(id, off, size) == 0)
121		if (volume_id_get_type(id, &type))
122			printf("%s\n", type);
123
124	return 0;
125}
126
127int main(int argc, char *argv[])
128{
129	static const struct option options[] = {
130		{ "label", 0, NULL, 'l' },
131		{ "label-raw", 0, NULL, 'L' },
132		{ "uuid", 0, NULL, 'u' },
133		{ "type", 0, NULL, 't' },
134		{ "export", 0, NULL, 'x' },
135		{ "skip-raid", 0, NULL, 's' },
136		{ "probe-all", 0, NULL, 'a' },
137		{ "help", 0, NULL, 'h' },
138		{}
139	};
140
141	enum print_type {
142		PRINT_EXPORT,
143		PRINT_TYPE,
144		PRINT_LABEL,
145		PRINT_UUID,
146		PRINT_LABEL_RAW,
147	} print = PRINT_EXPORT;
148
149	struct volume_id *vid = NULL;
150	char label_safe[256];
151	char label_enc[256];
152	char uuid_enc[256];
153	uint64_t size;
154	int skip_raid = 0;
155	int probe_all = 0;
156	const char *node;
157	int fd;
158	const char *label, *uuid, *type, *type_version, *usage;
159	int retval;
160	int rc = 0;
161
162	logging_init("vol_id");
163
164	/* hook in our debug into libvolume_id */
165	volume_id_log_fn = vid_log;
166
167	while (1) {
168		int option;
169
170		option = getopt_long(argc, argv, "lLutxsah", options, NULL);
171		if (option == -1)
172			break;
173
174		switch (option) {
175		case 'l':
176			print = PRINT_LABEL;
177			break;
178		case 'L':
179			print = PRINT_LABEL_RAW;
180			break;
181		case 'u':
182			print = PRINT_UUID;
183			break;
184		case 't':
185			print = PRINT_TYPE;
186			break;
187		case 'x':
188			print = PRINT_EXPORT;
189			break;
190		case 's':
191			skip_raid = 1;
192			break;
193		case 'a':
194			probe_all = 1;
195			break;
196		case 'h':
197			printf("Usage: vol_id [options] <device>\n"
198			    " --export        export key/value pairs\n"
199			    " --type          filesystem type\n"
200			    " --label         filesystem label\n"
201			    " --label-raw     raw label\n"
202			    " --uuid          filesystem uuid\n"
203			    " --skip-raid     don't probe for raid\n"
204			    " --probe-all     find possibly conflicting signatures\n"
205			    " --help\n\n");
206			goto exit;
207		default:
208			retval = 1;
209			goto exit;
210		}
211	}
212
213	node = argv[optind];
214	if (!node) {
215		err("no device");
216		fprintf(stderr, "no device\n");
217		rc = 1;
218		goto exit;
219	}
220
221	fd = open(node, O_RDONLY);
222	if (fd < 0) {
223		fprintf(stderr, "%s: error opening volume\n", node);
224		rc = 2;
225		goto exit;
226	}
227
228	vid = volume_id_open_fd(fd);
229	if (vid == NULL) {
230		rc = 2;
231		goto exit;
232	}
233
234	if (ioctl(fd, BLKGETSIZE64, &size) != 0)
235		size = 0;
236	dbg("BLKGETSIZE64=%llu", (unsigned long long)size);
237
238	/* try to drop all privileges before reading disk content */
239	if (getuid() == 0) {
240		struct passwd *pw;
241
242		pw = getpwnam("nobody");
243		if (pw != NULL && pw->pw_uid > 0 && pw->pw_gid > 0) {
244			if (setgroups(0, NULL) != 0 ||
245			    setgid(pw->pw_gid) != 0 ||
246			    setuid(pw->pw_uid) != 0)
247				info("unable to drop privileges: %s\n", strerror(errno));
248		}
249	}
250
251	if (probe_all) {
252		volume_id_all_probers(all_probers, vid, 0, size, NULL);
253		goto exit;
254	}
255
256	if (skip_raid)
257		retval = volume_id_probe_filesystem(vid, 0, size);
258	else
259		retval = volume_id_probe_all(vid, 0, size);
260	if (retval != 0) {
261		fprintf(stderr, "%s: unknown volume type\n", node);
262		rc = 4;
263		goto exit;
264	}
265
266	if (!volume_id_get_label(vid, &label) ||
267	    !volume_id_get_usage(vid, &usage) ||
268	    !volume_id_get_type(vid, &type) ||
269	    !volume_id_get_type_version(vid, &type_version) ||
270	    !volume_id_get_uuid(vid, &uuid)) {
271		rc = 4;
272		goto exit;
273	}
274
275	set_str(label_safe, label, sizeof(label_safe));
276	replace_chars(label_safe, ALLOWED_CHARS_INPUT);
277
278	volume_id_encode_string(label, label_enc, sizeof(label_enc));
279	volume_id_encode_string(uuid, uuid_enc, sizeof(uuid_enc));
280
281	switch (print) {
282	case PRINT_EXPORT:
283		printf("ID_FS_USAGE=%s\n", usage);
284		printf("ID_FS_TYPE=%s\n", type);
285		printf("ID_FS_VERSION=%s\n", type_version);
286		printf("ID_FS_UUID=%s\n", uuid);
287		printf("ID_FS_UUID_ENC=%s\n", uuid_enc);
288		printf("ID_FS_LABEL=%s\n", label);
289		printf("ID_FS_LABEL_ENC=%s\n", label_enc);
290		printf("ID_FS_LABEL_SAFE=%s\n", label_safe);
291		break;
292	case PRINT_TYPE:
293		printf("%s\n", type);
294		break;
295	case PRINT_LABEL:
296		if (label_safe[0] == '\0' || strcmp(usage, "raid") == 0) {
297			rc = 3;
298			goto exit;
299		}
300		printf("%s\n", label_safe);
301		break;
302	case PRINT_UUID:
303		if (uuid_enc[0] == '\0' || strcmp(usage, "raid") == 0) {
304			rc = 4;
305			goto exit;
306		}
307		printf("%s\n", uuid_enc);
308		break;
309	case PRINT_LABEL_RAW:
310		if (label[0] == '\0' || strcmp(usage, "raid") == 0) {
311			rc = 3;
312			goto exit;
313		}
314		printf("%s\n", label);
315		break;
316	}
317
318exit:
319	if (vid != NULL)
320		volume_id_close(vid);
321
322	logging_close();
323	return rc;
324}
325