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 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 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 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 */ 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 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 */ 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 */ 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 */ 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 }; 281 282 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 */ 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 } 314 315 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 */ 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 392 393 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 } 401 402 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
