1 /*
2 * tag.c - allocation/initialization/free routines for tag structs
3 *
4 * Copyright (C) 2001 Andreas Dilger
5 * Copyright (C) 2003 Theodore Ts'o
6 *
7 * %Begin-Header%
8 * This file may be redistributed under the terms of the
9 * GNU Lesser General Public License.
10 * %End-Header%
11 */
12
13 #include "config.h"
14 #include <unistd.h>
15 #include <stdlib.h>
16 #include <string.h>
17 #include <stdio.h>
18
19 #include "blkidP.h"
20
blkid_new_tag(void)21 static blkid_tag blkid_new_tag(void)
22 {
23 blkid_tag tag;
24
25 if (!(tag = (blkid_tag) calloc(1, sizeof(struct blkid_struct_tag))))
26 return NULL;
27
28 INIT_LIST_HEAD(&tag->bit_tags);
29 INIT_LIST_HEAD(&tag->bit_names);
30
31 return tag;
32 }
33
34 #ifdef CONFIG_BLKID_DEBUG
blkid_debug_dump_tag(blkid_tag tag)35 void blkid_debug_dump_tag(blkid_tag tag)
36 {
37 if (!tag) {
38 printf(" tag: NULL\n");
39 return;
40 }
41
42 printf(" tag: %s=\"%s\"\n", tag->bit_name, tag->bit_val);
43 }
44 #endif
45
blkid_free_tag(blkid_tag tag)46 void blkid_free_tag(blkid_tag tag)
47 {
48 if (!tag)
49 return;
50
51 DBG(DEBUG_TAG, printf(" freeing tag %s=%s\n", tag->bit_name,
52 tag->bit_val ? tag->bit_val : "(NULL)"));
53 DBG(DEBUG_TAG, blkid_debug_dump_tag(tag));
54
55 list_del(&tag->bit_tags); /* list of tags for this device */
56 list_del(&tag->bit_names); /* list of tags with this type */
57
58 free(tag->bit_name);
59 free(tag->bit_val);
60
61 free(tag);
62 }
63
64 /*
65 * Find the desired tag on a device. If value is NULL, then the
66 * first such tag is returned, otherwise return only exact tag if found.
67 */
blkid_find_tag_dev(blkid_dev dev,const char * type)68 blkid_tag blkid_find_tag_dev(blkid_dev dev, const char *type)
69 {
70 struct list_head *p;
71
72 if (!dev || !type)
73 return NULL;
74
75 list_for_each(p, &dev->bid_tags) {
76 blkid_tag tmp = list_entry(p, struct blkid_struct_tag,
77 bit_tags);
78
79 if (!strcmp(tmp->bit_name, type))
80 return tmp;
81 }
82 return NULL;
83 }
84
blkid_dev_has_tag(blkid_dev dev,const char * type,const char * value)85 extern int blkid_dev_has_tag(blkid_dev dev, const char *type,
86 const char *value)
87 {
88 blkid_tag tag;
89
90 if (!dev || !type)
91 return -1;
92
93 tag = blkid_find_tag_dev(dev, type);
94 if (!value)
95 return (tag != NULL);
96 if (!tag || strcmp(tag->bit_val, value))
97 return 0;
98 return 1;
99 }
100
101 /*
102 * Find the desired tag type in the cache.
103 * We return the head tag for this tag type.
104 */
blkid_find_head_cache(blkid_cache cache,const char * type)105 static blkid_tag blkid_find_head_cache(blkid_cache cache, const char *type)
106 {
107 blkid_tag head = NULL, tmp;
108 struct list_head *p;
109
110 if (!cache || !type)
111 return NULL;
112
113 list_for_each(p, &cache->bic_tags) {
114 tmp = list_entry(p, struct blkid_struct_tag, bit_tags);
115 if (!strcmp(tmp->bit_name, type)) {
116 DBG(DEBUG_TAG,
117 printf(" found cache tag head %s\n", type));
118 head = tmp;
119 break;
120 }
121 }
122 return head;
123 }
124
125 /*
126 * Set a tag on an existing device.
127 *
128 * If value is NULL, then delete the tagsfrom the device.
129 */
blkid_set_tag(blkid_dev dev,const char * name,const char * value,const int vlength)130 int blkid_set_tag(blkid_dev dev, const char *name,
131 const char *value, const int vlength)
132 {
133 blkid_tag t = 0, head = 0;
134 char *val = 0;
135 char **dev_var = 0;
136
137 if (!dev || !name)
138 return -BLKID_ERR_PARAM;
139
140 if (!(val = blkid_strndup(value, vlength)) && value)
141 return -BLKID_ERR_MEM;
142
143 /*
144 * Certain common tags are linked directly to the device struct
145 * We need to know what they are before we do anything else because
146 * the function name parameter might get freed later on.
147 */
148 if (!strcmp(name, "TYPE"))
149 dev_var = &dev->bid_type;
150 else if (!strcmp(name, "LABEL"))
151 dev_var = &dev->bid_label;
152 else if (!strcmp(name, "UUID"))
153 dev_var = &dev->bid_uuid;
154
155 t = blkid_find_tag_dev(dev, name);
156 if (!value) {
157 if (t)
158 blkid_free_tag(t);
159 } else if (t) {
160 if (!strcmp(t->bit_val, val)) {
161 /* Same thing, exit */
162 free(val);
163 return 0;
164 }
165 free(t->bit_val);
166 t->bit_val = val;
167 } else {
168 /* Existing tag not present, add to device */
169 if (!(t = blkid_new_tag()))
170 goto errout;
171 t->bit_name = blkid_strdup(name);
172 t->bit_val = val;
173 t->bit_dev = dev;
174
175 list_add_tail(&t->bit_tags, &dev->bid_tags);
176
177 if (dev->bid_cache) {
178 head = blkid_find_head_cache(dev->bid_cache,
179 t->bit_name);
180 if (!head) {
181 head = blkid_new_tag();
182 if (!head)
183 goto errout;
184
185 DBG(DEBUG_TAG,
186 printf(" creating new cache tag head %s\n", name));
187 head->bit_name = blkid_strdup(name);
188 if (!head->bit_name)
189 goto errout;
190 list_add_tail(&head->bit_tags,
191 &dev->bid_cache->bic_tags);
192 }
193 list_add_tail(&t->bit_names, &head->bit_names);
194 }
195 }
196
197 /* Link common tags directly to the device struct */
198 if (dev_var)
199 *dev_var = val;
200
201 if (dev->bid_cache)
202 dev->bid_cache->bic_flags |= BLKID_BIC_FL_CHANGED;
203 return 0;
204
205 errout:
206 if (t)
207 blkid_free_tag(t);
208 else free(val);
209 if (head)
210 blkid_free_tag(head);
211 return -BLKID_ERR_MEM;
212 }
213
214
215 /*
216 * Parse a "NAME=value" string. This is slightly different than
217 * parse_token, because that will end an unquoted value at a space, while
218 * this will assume that an unquoted value is the rest of the token (e.g.
219 * if we are passed an already quoted string from the command-line we don't
220 * have to both quote and escape quote so that the quotes make it to
221 * us).
222 *
223 * Returns 0 on success, and -1 on failure.
224 */
blkid_parse_tag_string(const char * token,char ** ret_type,char ** ret_val)225 int blkid_parse_tag_string(const char *token, char **ret_type, char **ret_val)
226 {
227 char *name, *value, *cp;
228
229 DBG(DEBUG_TAG, printf("trying to parse '%s' as a tag\n", token));
230
231 if (!token || !(cp = strchr(token, '=')))
232 return -1;
233
234 name = blkid_strdup(token);
235 if (!name)
236 return -1;
237 value = name + (cp - token);
238 *value++ = '\0';
239 if (*value == '"' || *value == '\'') {
240 char c = *value++;
241 if (!(cp = strrchr(value, c)))
242 goto errout; /* missing closing quote */
243 *cp = '\0';
244 }
245 value = blkid_strdup(value);
246 if (!value)
247 goto errout;
248
249 *ret_type = name;
250 *ret_val = value;
251
252 return 0;
253
254 errout:
255 free(name);
256 return -1;
257 }
258
259 /*
260 * Tag iteration routines for the public libblkid interface.
261 *
262 * These routines do not expose the list.h implementation, which are a
263 * contamination of the namespace, and which force us to reveal far, far
264 * too much of our internal implemenation. I'm not convinced I want
265 * to keep list.h in the long term, anyway. It's fine for kernel
266 * programming, but performance is not the #1 priority for this
267 * library, and I really don't like the tradeoff of type-safety for
268 * performance for this application. [tytso:20030125.2007EST]
269 */
270
271 /*
272 * This series of functions iterate over all tags in a device
273 */
274 #define TAG_ITERATE_MAGIC 0x01a5284c
275
276 struct blkid_struct_tag_iterate {
277 int magic;
278 blkid_dev dev;
279 struct list_head *p;
280 };
281
blkid_tag_iterate_begin(blkid_dev dev)282 extern blkid_tag_iterate blkid_tag_iterate_begin(blkid_dev dev)
283 {
284 blkid_tag_iterate iter;
285
286 iter = malloc(sizeof(struct blkid_struct_tag_iterate));
287 if (iter) {
288 iter->magic = TAG_ITERATE_MAGIC;
289 iter->dev = dev;
290 iter->p = dev->bid_tags.next;
291 }
292 return (iter);
293 }
294
295 /*
296 * Return 0 on success, -1 on error
297 */
blkid_tag_next(blkid_tag_iterate iter,const char ** type,const char ** value)298 extern int blkid_tag_next(blkid_tag_iterate iter,
299 const char **type, const char **value)
300 {
301 blkid_tag tag;
302
303 *type = 0;
304 *value = 0;
305 if (!iter || iter->magic != TAG_ITERATE_MAGIC ||
306 iter->p == &iter->dev->bid_tags)
307 return -1;
308 tag = list_entry(iter->p, struct blkid_struct_tag, bit_tags);
309 *type = tag->bit_name;
310 *value = tag->bit_val;
311 iter->p = iter->p->next;
312 return 0;
313 }
314
blkid_tag_iterate_end(blkid_tag_iterate iter)315 extern void blkid_tag_iterate_end(blkid_tag_iterate iter)
316 {
317 if (!iter || iter->magic != TAG_ITERATE_MAGIC)
318 return;
319 iter->magic = 0;
320 free(iter);
321 }
322
323 /*
324 * This function returns a device which matches a particular
325 * type/value pair. If there is more than one device that matches the
326 * search specification, it returns the one with the highest priority
327 * value. This allows us to give preference to EVMS or LVM devices.
328 */
blkid_find_dev_with_tag(blkid_cache cache,const char * type,const char * value)329 extern blkid_dev blkid_find_dev_with_tag(blkid_cache cache,
330 const char *type,
331 const char *value)
332 {
333 blkid_tag head;
334 blkid_dev dev;
335 int pri;
336 struct list_head *p;
337 int probe_new = 0;
338
339 if (!cache || !type || !value)
340 return NULL;
341
342 blkid_read_cache(cache);
343
344 DBG(DEBUG_TAG, printf("looking for %s=%s in cache\n", type, value));
345
346 try_again:
347 pri = -1;
348 dev = 0;
349 head = blkid_find_head_cache(cache, type);
350
351 if (head) {
352 list_for_each(p, &head->bit_names) {
353 blkid_tag tmp = list_entry(p, struct blkid_struct_tag,
354 bit_names);
355
356 if (!strcmp(tmp->bit_val, value) &&
357 (tmp->bit_dev->bid_pri > pri) &&
358 !access(tmp->bit_dev->bid_name, F_OK)) {
359 dev = tmp->bit_dev;
360 pri = dev->bid_pri;
361 }
362 }
363 }
364 if (dev && !(dev->bid_flags & BLKID_BID_FL_VERIFIED)) {
365 dev = blkid_verify(cache, dev);
366 if (!dev || (dev && (dev->bid_flags & BLKID_BID_FL_VERIFIED)))
367 goto try_again;
368 }
369
370 if (!dev && !probe_new) {
371 if (blkid_probe_all_new(cache) < 0)
372 return NULL;
373 probe_new++;
374 goto try_again;
375 }
376
377 if (!dev && !(cache->bic_flags & BLKID_BIC_FL_PROBED)) {
378 if (blkid_probe_all(cache) < 0)
379 return NULL;
380 goto try_again;
381 }
382 return dev;
383 }
384
385 #ifdef TEST_PROGRAM
386 #ifdef HAVE_GETOPT_H
387 #include <getopt.h>
388 #else
389 extern char *optarg;
390 extern int optind;
391 #endif
392
usage(char * prog)393 void usage(char *prog)
394 {
395 fprintf(stderr, "Usage: %s [-f blkid_file] [-m debug_mask] device "
396 "[type value]\n",
397 prog);
398 fprintf(stderr, "\tList all tags for a device and exit\n");
399 exit(1);
400 }
401
main(int argc,char ** argv)402 int main(int argc, char **argv)
403 {
404 blkid_tag_iterate iter;
405 blkid_cache cache = NULL;
406 blkid_dev dev;
407 int c, ret, found;
408 int flags = BLKID_DEV_FIND;
409 char *tmp;
410 char *file = NULL;
411 char *devname = NULL;
412 char *search_type = NULL;
413 char *search_value = NULL;
414 const char *type, *value;
415
416 while ((c = getopt (argc, argv, "m:f:")) != EOF)
417 switch (c) {
418 case 'f':
419 file = optarg;
420 break;
421 case 'm':
422 blkid_debug_mask = strtoul (optarg, &tmp, 0);
423 if (*tmp) {
424 fprintf(stderr, "Invalid debug mask: %s\n",
425 optarg);
426 exit(1);
427 }
428 break;
429 case '?':
430 usage(argv[0]);
431 }
432 if (argc > optind)
433 devname = argv[optind++];
434 if (argc > optind)
435 search_type = argv[optind++];
436 if (argc > optind)
437 search_value = argv[optind++];
438 if (!devname || (argc != optind))
439 usage(argv[0]);
440
441 if ((ret = blkid_get_cache(&cache, file)) != 0) {
442 fprintf(stderr, "%s: error creating cache (%d)\n",
443 argv[0], ret);
444 exit(1);
445 }
446
447 dev = blkid_get_dev(cache, devname, flags);
448 if (!dev) {
449 fprintf(stderr, "%s: Can not find device in blkid cache\n",
450 devname);
451 exit(1);
452 }
453 if (search_type) {
454 found = blkid_dev_has_tag(dev, search_type, search_value);
455 printf("Device %s: (%s, %s) %s\n", blkid_dev_devname(dev),
456 search_type, search_value ? search_value : "NULL",
457 found ? "FOUND" : "NOT FOUND");
458 return(!found);
459 }
460 printf("Device %s...\n", blkid_dev_devname(dev));
461
462 iter = blkid_tag_iterate_begin(dev);
463 while (blkid_tag_next(iter, &type, &value) == 0) {
464 printf("\tTag %s has value %s\n", type, value);
465 }
466 blkid_tag_iterate_end(iter);
467
468 blkid_put_cache(cache);
469 return (0);
470 }
471 #endif
472