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