Tristan Matthews | 0461646 | 2013-11-14 16:09:34 -0500 | [diff] [blame] | 1 | /************************************************* |
| 2 | * Perl-Compatible Regular Expressions * |
| 3 | *************************************************/ |
| 4 | |
| 5 | /* PCRE is a library of functions to support regular expressions whose syntax |
| 6 | and semantics are as close as possible to those of the Perl 5 language. |
| 7 | |
| 8 | Written by Philip Hazel |
| 9 | Copyright (c) 1997-2008 University of Cambridge |
| 10 | |
| 11 | ----------------------------------------------------------------------------- |
| 12 | Redistribution and use in source and binary forms, with or without |
| 13 | modification, are permitted provided that the following conditions are met: |
| 14 | |
| 15 | * Redistributions of source code must retain the above copyright notice, |
| 16 | this list of conditions and the following disclaimer. |
| 17 | |
| 18 | * Redistributions in binary form must reproduce the above copyright |
| 19 | notice, this list of conditions and the following disclaimer in the |
| 20 | documentation and/or other materials provided with the distribution. |
| 21 | |
| 22 | * Neither the name of the University of Cambridge nor the names of its |
| 23 | contributors may be used to endorse or promote products derived from |
| 24 | this software without specific prior written permission. |
| 25 | |
| 26 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| 27 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 28 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 29 | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| 30 | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 31 | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 32 | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 33 | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 34 | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 35 | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 36 | POSSIBILITY OF SUCH DAMAGE. |
| 37 | ----------------------------------------------------------------------------- |
| 38 | */ |
| 39 | |
| 40 | |
| 41 | /* This module contains some convenience functions for extracting substrings |
| 42 | from the subject string after a regex match has succeeded. The original idea |
| 43 | for these functions came from Scott Wimer. */ |
| 44 | |
| 45 | |
| 46 | #ifdef HAVE_CONFIG_H |
| 47 | #include "config.h" |
| 48 | #endif |
| 49 | |
| 50 | #include "pcre_internal.h" |
| 51 | |
| 52 | |
| 53 | /************************************************* |
| 54 | * Find number for named string * |
| 55 | *************************************************/ |
| 56 | |
| 57 | /* This function is used by the get_first_set() function below, as well |
| 58 | as being generally available. It assumes that names are unique. |
| 59 | |
| 60 | Arguments: |
| 61 | code the compiled regex |
| 62 | stringname the name whose number is required |
| 63 | |
| 64 | Returns: the number of the named parentheses, or a negative number |
| 65 | (PCRE_ERROR_NOSUBSTRING) if not found |
| 66 | */ |
| 67 | |
| 68 | PCRE_EXP_DEFN int PCRE_CALL_CONVENTION |
| 69 | pcre_get_stringnumber(const pcre *code, const char *stringname) |
| 70 | { |
| 71 | int rc; |
| 72 | int entrysize; |
| 73 | int top, bot; |
| 74 | uschar *nametable; |
| 75 | |
| 76 | if ((rc = pcre_fullinfo(code, NULL, PCRE_INFO_NAMECOUNT, &top)) != 0) |
| 77 | return rc; |
| 78 | if (top <= 0) return PCRE_ERROR_NOSUBSTRING; |
| 79 | |
| 80 | if ((rc = pcre_fullinfo(code, NULL, PCRE_INFO_NAMEENTRYSIZE, &entrysize)) != 0) |
| 81 | return rc; |
| 82 | if ((rc = pcre_fullinfo(code, NULL, PCRE_INFO_NAMETABLE, &nametable)) != 0) |
| 83 | return rc; |
| 84 | |
| 85 | bot = 0; |
| 86 | while (top > bot) |
| 87 | { |
| 88 | int mid = (top + bot) / 2; |
| 89 | uschar *entry = nametable + entrysize*mid; |
| 90 | int c = strcmp(stringname, (char *)(entry + 2)); |
| 91 | if (c == 0) return (entry[0] << 8) + entry[1]; |
| 92 | if (c > 0) bot = mid + 1; else top = mid; |
| 93 | } |
| 94 | |
| 95 | return PCRE_ERROR_NOSUBSTRING; |
| 96 | } |
| 97 | |
| 98 | |
| 99 | |
| 100 | /************************************************* |
| 101 | * Find (multiple) entries for named string * |
| 102 | *************************************************/ |
| 103 | |
| 104 | /* This is used by the get_first_set() function below, as well as being |
| 105 | generally available. It is used when duplicated names are permitted. |
| 106 | |
| 107 | Arguments: |
| 108 | code the compiled regex |
| 109 | stringname the name whose entries required |
| 110 | firstptr where to put the pointer to the first entry |
| 111 | lastptr where to put the pointer to the last entry |
| 112 | |
| 113 | Returns: the length of each entry, or a negative number |
| 114 | (PCRE_ERROR_NOSUBSTRING) if not found |
| 115 | */ |
| 116 | |
| 117 | PCRE_EXP_DEFN int PCRE_CALL_CONVENTION |
| 118 | pcre_get_stringtable_entries(const pcre *code, const char *stringname, |
| 119 | char **firstptr, char **lastptr) |
| 120 | { |
| 121 | int rc; |
| 122 | int entrysize; |
| 123 | int top, bot; |
| 124 | uschar *nametable, *lastentry; |
| 125 | |
| 126 | if ((rc = pcre_fullinfo(code, NULL, PCRE_INFO_NAMECOUNT, &top)) != 0) |
| 127 | return rc; |
| 128 | if (top <= 0) return PCRE_ERROR_NOSUBSTRING; |
| 129 | |
| 130 | if ((rc = pcre_fullinfo(code, NULL, PCRE_INFO_NAMEENTRYSIZE, &entrysize)) != 0) |
| 131 | return rc; |
| 132 | if ((rc = pcre_fullinfo(code, NULL, PCRE_INFO_NAMETABLE, &nametable)) != 0) |
| 133 | return rc; |
| 134 | |
| 135 | lastentry = nametable + entrysize * (top - 1); |
| 136 | bot = 0; |
| 137 | while (top > bot) |
| 138 | { |
| 139 | int mid = (top + bot) / 2; |
| 140 | uschar *entry = nametable + entrysize*mid; |
| 141 | int c = strcmp(stringname, (char *)(entry + 2)); |
| 142 | if (c == 0) |
| 143 | { |
| 144 | uschar *first = entry; |
| 145 | uschar *last = entry; |
| 146 | while (first > nametable) |
| 147 | { |
| 148 | if (strcmp(stringname, (char *)(first - entrysize + 2)) != 0) break; |
| 149 | first -= entrysize; |
| 150 | } |
| 151 | while (last < lastentry) |
| 152 | { |
| 153 | if (strcmp(stringname, (char *)(last + entrysize + 2)) != 0) break; |
| 154 | last += entrysize; |
| 155 | } |
| 156 | *firstptr = (char *)first; |
| 157 | *lastptr = (char *)last; |
| 158 | return entrysize; |
| 159 | } |
| 160 | if (c > 0) bot = mid + 1; else top = mid; |
| 161 | } |
| 162 | |
| 163 | return PCRE_ERROR_NOSUBSTRING; |
| 164 | } |
| 165 | |
| 166 | |
| 167 | |
| 168 | /************************************************* |
| 169 | * Find first set of multiple named strings * |
| 170 | *************************************************/ |
| 171 | |
| 172 | /* This function allows for duplicate names in the table of named substrings. |
| 173 | It returns the number of the first one that was set in a pattern match. |
| 174 | |
| 175 | Arguments: |
| 176 | code the compiled regex |
| 177 | stringname the name of the capturing substring |
| 178 | ovector the vector of matched substrings |
| 179 | |
| 180 | Returns: the number of the first that is set, |
| 181 | or the number of the last one if none are set, |
| 182 | or a negative number on error |
| 183 | */ |
| 184 | |
| 185 | static int |
| 186 | get_first_set(const pcre *code, const char *stringname, int *ovector) |
| 187 | { |
| 188 | const real_pcre *re = (const real_pcre *)code; |
| 189 | int entrysize; |
| 190 | char *first, *last; |
| 191 | uschar *entry; |
| 192 | if ((re->options & PCRE_DUPNAMES) == 0 && (re->flags & PCRE_JCHANGED) == 0) |
| 193 | return pcre_get_stringnumber(code, stringname); |
| 194 | entrysize = pcre_get_stringtable_entries(code, stringname, &first, &last); |
| 195 | if (entrysize <= 0) return entrysize; |
| 196 | for (entry = (uschar *)first; entry <= (uschar *)last; entry += entrysize) |
| 197 | { |
| 198 | int n = (entry[0] << 8) + entry[1]; |
| 199 | if (ovector[n*2] >= 0) return n; |
| 200 | } |
| 201 | return (first[0] << 8) + first[1]; |
| 202 | } |
| 203 | |
| 204 | |
| 205 | |
| 206 | |
| 207 | /************************************************* |
| 208 | * Copy captured string to given buffer * |
| 209 | *************************************************/ |
| 210 | |
| 211 | /* This function copies a single captured substring into a given buffer. |
| 212 | Note that we use memcpy() rather than strncpy() in case there are binary zeros |
| 213 | in the string. |
| 214 | |
| 215 | Arguments: |
| 216 | subject the subject string that was matched |
| 217 | ovector pointer to the offsets table |
| 218 | stringcount the number of substrings that were captured |
| 219 | (i.e. the yield of the pcre_exec call, unless |
| 220 | that was zero, in which case it should be 1/3 |
| 221 | of the offset table size) |
| 222 | stringnumber the number of the required substring |
| 223 | buffer where to put the substring |
| 224 | size the size of the buffer |
| 225 | |
| 226 | Returns: if successful: |
| 227 | the length of the copied string, not including the zero |
| 228 | that is put on the end; can be zero |
| 229 | if not successful: |
| 230 | PCRE_ERROR_NOMEMORY (-6) buffer too small |
| 231 | PCRE_ERROR_NOSUBSTRING (-7) no such captured substring |
| 232 | */ |
| 233 | |
| 234 | PCRE_EXP_DEFN int PCRE_CALL_CONVENTION |
| 235 | pcre_copy_substring(const char *subject, int *ovector, int stringcount, |
| 236 | int stringnumber, char *buffer, int size) |
| 237 | { |
| 238 | int yield; |
| 239 | if (stringnumber < 0 || stringnumber >= stringcount) |
| 240 | return PCRE_ERROR_NOSUBSTRING; |
| 241 | stringnumber *= 2; |
| 242 | yield = ovector[stringnumber+1] - ovector[stringnumber]; |
| 243 | if (size < yield + 1) return PCRE_ERROR_NOMEMORY; |
| 244 | memcpy(buffer, subject + ovector[stringnumber], yield); |
| 245 | buffer[yield] = 0; |
| 246 | return yield; |
| 247 | } |
| 248 | |
| 249 | |
| 250 | |
| 251 | /************************************************* |
| 252 | * Copy named captured string to given buffer * |
| 253 | *************************************************/ |
| 254 | |
| 255 | /* This function copies a single captured substring into a given buffer, |
| 256 | identifying it by name. If the regex permits duplicate names, the first |
| 257 | substring that is set is chosen. |
| 258 | |
| 259 | Arguments: |
| 260 | code the compiled regex |
| 261 | subject the subject string that was matched |
| 262 | ovector pointer to the offsets table |
| 263 | stringcount the number of substrings that were captured |
| 264 | (i.e. the yield of the pcre_exec call, unless |
| 265 | that was zero, in which case it should be 1/3 |
| 266 | of the offset table size) |
| 267 | stringname the name of the required substring |
| 268 | buffer where to put the substring |
| 269 | size the size of the buffer |
| 270 | |
| 271 | Returns: if successful: |
| 272 | the length of the copied string, not including the zero |
| 273 | that is put on the end; can be zero |
| 274 | if not successful: |
| 275 | PCRE_ERROR_NOMEMORY (-6) buffer too small |
| 276 | PCRE_ERROR_NOSUBSTRING (-7) no such captured substring |
| 277 | */ |
| 278 | |
| 279 | PCRE_EXP_DEFN int PCRE_CALL_CONVENTION |
| 280 | pcre_copy_named_substring(const pcre *code, const char *subject, int *ovector, |
| 281 | int stringcount, const char *stringname, char *buffer, int size) |
| 282 | { |
| 283 | int n = get_first_set(code, stringname, ovector); |
| 284 | if (n <= 0) return n; |
| 285 | return pcre_copy_substring(subject, ovector, stringcount, n, buffer, size); |
| 286 | } |
| 287 | |
| 288 | |
| 289 | |
| 290 | /************************************************* |
| 291 | * Copy all captured strings to new store * |
| 292 | *************************************************/ |
| 293 | |
| 294 | /* This function gets one chunk of store and builds a list of pointers and all |
| 295 | of the captured substrings in it. A NULL pointer is put on the end of the list. |
| 296 | |
| 297 | Arguments: |
| 298 | subject the subject string that was matched |
| 299 | ovector pointer to the offsets table |
| 300 | stringcount the number of substrings that were captured |
| 301 | (i.e. the yield of the pcre_exec call, unless |
| 302 | that was zero, in which case it should be 1/3 |
| 303 | of the offset table size) |
| 304 | listptr set to point to the list of pointers |
| 305 | |
| 306 | Returns: if successful: 0 |
| 307 | if not successful: |
| 308 | PCRE_ERROR_NOMEMORY (-6) failed to get store |
| 309 | */ |
| 310 | |
| 311 | PCRE_EXP_DEFN int PCRE_CALL_CONVENTION |
| 312 | pcre_get_substring_list(const char *subject, int *ovector, int stringcount, |
| 313 | const char ***listptr) |
| 314 | { |
| 315 | int i; |
| 316 | int size = sizeof(char *); |
| 317 | int double_count = stringcount * 2; |
| 318 | char **stringlist; |
| 319 | char *p; |
| 320 | |
| 321 | for (i = 0; i < double_count; i += 2) |
| 322 | size += sizeof(char *) + ovector[i+1] - ovector[i] + 1; |
| 323 | |
| 324 | stringlist = (char **)(pcre_malloc)(size); |
| 325 | if (stringlist == NULL) return PCRE_ERROR_NOMEMORY; |
| 326 | |
| 327 | *listptr = (const char **)stringlist; |
| 328 | p = (char *)(stringlist + stringcount + 1); |
| 329 | |
| 330 | for (i = 0; i < double_count; i += 2) |
| 331 | { |
| 332 | int len = ovector[i+1] - ovector[i]; |
| 333 | memcpy(p, subject + ovector[i], len); |
| 334 | *stringlist++ = p; |
| 335 | p += len; |
| 336 | *p++ = 0; |
| 337 | } |
| 338 | |
| 339 | *stringlist = NULL; |
| 340 | return 0; |
| 341 | } |
| 342 | |
| 343 | |
| 344 | |
| 345 | /************************************************* |
| 346 | * Free store obtained by get_substring_list * |
| 347 | *************************************************/ |
| 348 | |
| 349 | /* This function exists for the benefit of people calling PCRE from non-C |
| 350 | programs that can call its functions, but not free() or (pcre_free)() directly. |
| 351 | |
| 352 | Argument: the result of a previous pcre_get_substring_list() |
| 353 | Returns: nothing |
| 354 | */ |
| 355 | |
| 356 | PCRE_EXP_DEFN void PCRE_CALL_CONVENTION |
| 357 | pcre_free_substring_list(const char **pointer) |
| 358 | { |
| 359 | (pcre_free)((void *)pointer); |
| 360 | } |
| 361 | |
| 362 | |
| 363 | |
| 364 | /************************************************* |
| 365 | * Copy captured string to new store * |
| 366 | *************************************************/ |
| 367 | |
| 368 | /* This function copies a single captured substring into a piece of new |
| 369 | store |
| 370 | |
| 371 | Arguments: |
| 372 | subject the subject string that was matched |
| 373 | ovector pointer to the offsets table |
| 374 | stringcount the number of substrings that were captured |
| 375 | (i.e. the yield of the pcre_exec call, unless |
| 376 | that was zero, in which case it should be 1/3 |
| 377 | of the offset table size) |
| 378 | stringnumber the number of the required substring |
| 379 | stringptr where to put a pointer to the substring |
| 380 | |
| 381 | Returns: if successful: |
| 382 | the length of the string, not including the zero that |
| 383 | is put on the end; can be zero |
| 384 | if not successful: |
| 385 | PCRE_ERROR_NOMEMORY (-6) failed to get store |
| 386 | PCRE_ERROR_NOSUBSTRING (-7) substring not present |
| 387 | */ |
| 388 | |
| 389 | PCRE_EXP_DEFN int PCRE_CALL_CONVENTION |
| 390 | pcre_get_substring(const char *subject, int *ovector, int stringcount, |
| 391 | int stringnumber, const char **stringptr) |
| 392 | { |
| 393 | int yield; |
| 394 | char *substring; |
| 395 | if (stringnumber < 0 || stringnumber >= stringcount) |
| 396 | return PCRE_ERROR_NOSUBSTRING; |
| 397 | stringnumber *= 2; |
| 398 | yield = ovector[stringnumber+1] - ovector[stringnumber]; |
| 399 | substring = (char *)(pcre_malloc)(yield + 1); |
| 400 | if (substring == NULL) return PCRE_ERROR_NOMEMORY; |
| 401 | memcpy(substring, subject + ovector[stringnumber], yield); |
| 402 | substring[yield] = 0; |
| 403 | *stringptr = substring; |
| 404 | return yield; |
| 405 | } |
| 406 | |
| 407 | |
| 408 | |
| 409 | /************************************************* |
| 410 | * Copy named captured string to new store * |
| 411 | *************************************************/ |
| 412 | |
| 413 | /* This function copies a single captured substring, identified by name, into |
| 414 | new store. If the regex permits duplicate names, the first substring that is |
| 415 | set is chosen. |
| 416 | |
| 417 | Arguments: |
| 418 | code the compiled regex |
| 419 | subject the subject string that was matched |
| 420 | ovector pointer to the offsets table |
| 421 | stringcount the number of substrings that were captured |
| 422 | (i.e. the yield of the pcre_exec call, unless |
| 423 | that was zero, in which case it should be 1/3 |
| 424 | of the offset table size) |
| 425 | stringname the name of the required substring |
| 426 | stringptr where to put the pointer |
| 427 | |
| 428 | Returns: if successful: |
| 429 | the length of the copied string, not including the zero |
| 430 | that is put on the end; can be zero |
| 431 | if not successful: |
| 432 | PCRE_ERROR_NOMEMORY (-6) couldn't get memory |
| 433 | PCRE_ERROR_NOSUBSTRING (-7) no such captured substring |
| 434 | */ |
| 435 | |
| 436 | PCRE_EXP_DEFN int PCRE_CALL_CONVENTION |
| 437 | pcre_get_named_substring(const pcre *code, const char *subject, int *ovector, |
| 438 | int stringcount, const char *stringname, const char **stringptr) |
| 439 | { |
| 440 | int n = get_first_set(code, stringname, ovector); |
| 441 | if (n <= 0) return n; |
| 442 | return pcre_get_substring(subject, ovector, stringcount, n, stringptr); |
| 443 | } |
| 444 | |
| 445 | |
| 446 | |
| 447 | |
| 448 | /************************************************* |
| 449 | * Free store obtained by get_substring * |
| 450 | *************************************************/ |
| 451 | |
| 452 | /* This function exists for the benefit of people calling PCRE from non-C |
| 453 | programs that can call its functions, but not free() or (pcre_free)() directly. |
| 454 | |
| 455 | Argument: the result of a previous pcre_get_substring() |
| 456 | Returns: nothing |
| 457 | */ |
| 458 | |
| 459 | PCRE_EXP_DEFN void PCRE_CALL_CONVENTION |
| 460 | pcre_free_substring(const char *pointer) |
| 461 | { |
| 462 | (pcre_free)((void *)pointer); |
| 463 | } |
| 464 | |
| 465 | /* End of pcre_get.c */ |