1 /* 2 * Copyright (c) Christos Zoulas 2003. 3 * All Rights Reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice immediately at the beginning of the file, without modification, 10 * this list of conditions, and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 19 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 #include "file.h" 28 29 #ifndef lint 30 FILE_RCSID("@(#)$File: funcs.c,v 1.72 2014/05/14 23:15:42 christos Exp $") 31 #endif /* lint */ 32 33 #include "magic.h" 34 #include <assert.h> 35 #include <stdarg.h> 36 #include <stdlib.h> 37 #include <string.h> 38 #include <ctype.h> 39 #if defined(HAVE_WCHAR_H) 40 #include <wchar.h> 41 #endif 42 #if defined(HAVE_WCTYPE_H) 43 #include <wctype.h> 44 #endif 45 #if defined(HAVE_LIMITS_H) 46 #include <limits.h> 47 #endif 48 #if defined(HAVE_LOCALE_H) 49 #include <locale.h> 50 #endif 51 52 #ifndef SIZE_MAX 53 #define SIZE_MAX ((size_t)~0) 54 #endif 55 56 /* 57 * Like printf, only we append to a buffer. 58 */ 59 protected int 60 file_vprintf(struct magic_set *ms, const char *fmt, va_list ap) 61 { 62 int len; 63 char *buf, *newstr; 64 65 if (ms->event_flags & EVENT_HAD_ERR) 66 return 0; 67 len = vasprintf(&buf, fmt, ap); 68 if (len < 0) 69 goto out; 70 71 if (ms->o.buf != NULL) { 72 len = asprintf(&newstr, "%s%s", ms->o.buf, buf); 73 free(buf); 74 if (len < 0) 75 goto out; 76 free(ms->o.buf); 77 buf = newstr; 78 } 79 ms->o.buf = buf; 80 return 0; 81 out: 82 file_error(ms, errno, "vasprintf failed"); 83 return -1; 84 } 85 86 protected int 87 file_printf(struct magic_set *ms, const char *fmt, ...) 88 { 89 int rv; 90 va_list ap; 91 92 va_start(ap, fmt); 93 rv = file_vprintf(ms, fmt, ap); 94 va_end(ap); 95 return rv; 96 } 97 98 /* 99 * error - print best error message possible 100 */ 101 /*VARARGS*/ 102 __attribute__((__format__(__printf__, 3, 0))) 103 private void 104 file_error_core(struct magic_set *ms, int error, const char *f, va_list va, 105 size_t lineno) 106 { 107 /* Only the first error is ok */ 108 if (ms->event_flags & EVENT_HAD_ERR) 109 return; 110 if (lineno != 0) { 111 free(ms->o.buf); 112 ms->o.buf = NULL; 113 file_printf(ms, "line %" SIZE_T_FORMAT "u: ", lineno); 114 } 115 file_vprintf(ms, f, va); 116 if (error > 0) 117 file_printf(ms, " (%s)", strerror(error)); 118 ms->event_flags |= EVENT_HAD_ERR; 119 ms->error = error; 120 } 121 122 /*VARARGS*/ 123 protected void 124 file_error(struct magic_set *ms, int error, const char *f, ...) 125 { 126 va_list va; 127 va_start(va, f); 128 file_error_core(ms, error, f, va, 0); 129 va_end(va); 130 } 131 132 /* 133 * Print an error with magic line number. 134 */ 135 /*VARARGS*/ 136 protected void 137 file_magerror(struct magic_set *ms, const char *f, ...) 138 { 139 va_list va; 140 va_start(va, f); 141 file_error_core(ms, 0, f, va, ms->line); 142 va_end(va); 143 } 144 145 protected void 146 file_oomem(struct magic_set *ms, size_t len) 147 { 148 file_error(ms, errno, "cannot allocate %" SIZE_T_FORMAT "u bytes", 149 len); 150 } 151 152 protected void 153 file_badseek(struct magic_set *ms) 154 { 155 file_error(ms, errno, "error seeking"); 156 } 157 158 protected void 159 file_badread(struct magic_set *ms) 160 { 161 file_error(ms, errno, "error reading"); 162 } 163 164 #ifndef COMPILE_ONLY 165 protected int 166 file_buffer(struct magic_set *ms, int fd, const char *inname __attribute__ ((unused)), 167 const void *buf, size_t nb) 168 { 169 int m = 0, rv = 0, looks_text = 0; 170 int mime = ms->flags & MAGIC_MIME; 171 const unsigned char *ubuf = CAST(const unsigned char *, buf); 172 unichar *u8buf = NULL; 173 size_t ulen; 174 const char *code = NULL; 175 const char *code_mime = "binary"; 176 const char *type = "application/octet-stream"; 177 const char *def = "data"; 178 const char *ftype = NULL; 179 180 if (nb == 0) { 181 def = "empty"; 182 type = "application/x-empty"; 183 goto simple; 184 } else if (nb == 1) { 185 def = "very short file (no magic)"; 186 goto simple; 187 } 188 189 if ((ms->flags & MAGIC_NO_CHECK_ENCODING) == 0) { 190 looks_text = file_encoding(ms, ubuf, nb, &u8buf, &ulen, 191 &code, &code_mime, &ftype); 192 } 193 194 #ifdef __EMX__ 195 if ((ms->flags & MAGIC_NO_CHECK_APPTYPE) == 0 && inname) { 196 switch (file_os2_apptype(ms, inname, buf, nb)) { 197 case -1: 198 return -1; 199 case 0: 200 break; 201 default: 202 return 1; 203 } 204 } 205 #endif 206 #if HAVE_FORK 207 /* try compression stuff */ 208 if ((ms->flags & MAGIC_NO_CHECK_COMPRESS) == 0) 209 if ((m = file_zmagic(ms, fd, inname, ubuf, nb)) != 0) { 210 if ((ms->flags & MAGIC_DEBUG) != 0) 211 (void)fprintf(stderr, "zmagic %d\n", m); 212 goto done_encoding; 213 } 214 #endif 215 /* Check if we have a tar file */ 216 if ((ms->flags & MAGIC_NO_CHECK_TAR) == 0) 217 if ((m = file_is_tar(ms, ubuf, nb)) != 0) { 218 if ((ms->flags & MAGIC_DEBUG) != 0) 219 (void)fprintf(stderr, "tar %d\n", m); 220 goto done; 221 } 222 223 /* Check if we have a CDF file */ 224 if ((ms->flags & MAGIC_NO_CHECK_CDF) == 0) 225 if ((m = file_trycdf(ms, fd, ubuf, nb)) != 0) { 226 if ((ms->flags & MAGIC_DEBUG) != 0) 227 (void)fprintf(stderr, "cdf %d\n", m); 228 goto done; 229 } 230 231 /* try soft magic tests */ 232 if ((ms->flags & MAGIC_NO_CHECK_SOFT) == 0) 233 if ((m = file_softmagic(ms, ubuf, nb, 0, BINTEST, 234 looks_text)) != 0) { 235 if ((ms->flags & MAGIC_DEBUG) != 0) 236 (void)fprintf(stderr, "softmagic %d\n", m); 237 #ifdef BUILTIN_ELF 238 if ((ms->flags & MAGIC_NO_CHECK_ELF) == 0 && m == 1 && 239 nb > 5 && fd != -1) { 240 /* 241 * We matched something in the file, so this 242 * *might* be an ELF file, and the file is at 243 * least 5 bytes long, so if it's an ELF file 244 * it has at least one byte past the ELF magic 245 * number - try extracting information from the 246 * ELF headers that cannot easily * be 247 * extracted with rules in the magic file. 248 */ 249 if ((m = file_tryelf(ms, fd, ubuf, nb)) != 0) 250 if ((ms->flags & MAGIC_DEBUG) != 0) 251 (void)fprintf(stderr, 252 "elf %d\n", m); 253 } 254 #endif 255 goto done; 256 } 257 258 /* try text properties */ 259 if ((ms->flags & MAGIC_NO_CHECK_TEXT) == 0) { 260 261 if ((m = file_ascmagic(ms, ubuf, nb, looks_text)) != 0) { 262 if ((ms->flags & MAGIC_DEBUG) != 0) 263 (void)fprintf(stderr, "ascmagic %d\n", m); 264 goto done; 265 } 266 } 267 268 simple: 269 /* give up */ 270 m = 1; 271 if ((!mime || (mime & MAGIC_MIME_TYPE)) && 272 file_printf(ms, "%s", mime ? type : def) == -1) { 273 rv = -1; 274 } 275 done: 276 if ((ms->flags & MAGIC_MIME_ENCODING) != 0) { 277 if (ms->flags & MAGIC_MIME_TYPE) 278 if (file_printf(ms, "; charset=") == -1) 279 rv = -1; 280 if (file_printf(ms, "%s", code_mime) == -1) 281 rv = -1; 282 } 283 #if HAVE_FORK 284 done_encoding: 285 #endif 286 free(u8buf); 287 if (rv) 288 return rv; 289 290 return m; 291 } 292 #endif 293 294 protected int 295 file_reset(struct magic_set *ms) 296 { 297 if (ms->mlist[0] == NULL) { 298 file_error(ms, 0, "no magic files loaded"); 299 return -1; 300 } 301 if (ms->o.buf) { 302 free(ms->o.buf); 303 ms->o.buf = NULL; 304 } 305 if (ms->o.pbuf) { 306 free(ms->o.pbuf); 307 ms->o.pbuf = NULL; 308 } 309 ms->event_flags &= ~EVENT_HAD_ERR; 310 ms->error = -1; 311 return 0; 312 } 313 314 #define OCTALIFY(n, o) \ 315 /*LINTED*/ \ 316 (void)(*(n)++ = '\\', \ 317 *(n)++ = (((uint32_t)*(o) >> 6) & 3) + '0', \ 318 *(n)++ = (((uint32_t)*(o) >> 3) & 7) + '0', \ 319 *(n)++ = (((uint32_t)*(o) >> 0) & 7) + '0', \ 320 (o)++) 321 322 protected const char * 323 file_getbuffer(struct magic_set *ms) 324 { 325 char *pbuf, *op, *np; 326 size_t psize, len; 327 328 if (ms->event_flags & EVENT_HAD_ERR) 329 return NULL; 330 331 if (ms->flags & MAGIC_RAW) 332 return ms->o.buf; 333 334 if (ms->o.buf == NULL) 335 return NULL; 336 337 /* * 4 is for octal representation, + 1 is for NUL */ 338 len = strlen(ms->o.buf); 339 if (len > (SIZE_MAX - 1) / 4) { 340 file_oomem(ms, len); 341 return NULL; 342 } 343 psize = len * 4 + 1; 344 if ((pbuf = CAST(char *, realloc(ms->o.pbuf, psize))) == NULL) { 345 file_oomem(ms, psize); 346 return NULL; 347 } 348 ms->o.pbuf = pbuf; 349 350 #if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH) 351 { 352 mbstate_t state; 353 wchar_t nextchar; 354 int mb_conv = 1; 355 size_t bytesconsumed; 356 char *eop; 357 (void)memset(&state, 0, sizeof(mbstate_t)); 358 359 np = ms->o.pbuf; 360 op = ms->o.buf; 361 eop = op + len; 362 363 while (op < eop) { 364 bytesconsumed = mbrtowc(&nextchar, op, 365 (size_t)(eop - op), &state); 366 if (bytesconsumed == (size_t)(-1) || 367 bytesconsumed == (size_t)(-2)) { 368 mb_conv = 0; 369 break; 370 } 371 372 if (iswprint(nextchar)) { 373 (void)memcpy(np, op, bytesconsumed); 374 op += bytesconsumed; 375 np += bytesconsumed; 376 } else { 377 while (bytesconsumed-- > 0) 378 OCTALIFY(np, op); 379 } 380 } 381 *np = '\0'; 382 383 /* Parsing succeeded as a multi-byte sequence */ 384 if (mb_conv != 0) 385 return ms->o.pbuf; 386 } 387 #endif 388 389 for (np = ms->o.pbuf, op = ms->o.buf; *op;) { 390 if (isprint((unsigned char)*op)) { 391 *np++ = *op++; 392 } else { 393 OCTALIFY(np, op); 394 } 395 } 396 *np = '\0'; 397 return ms->o.pbuf; 398 } 399 400 protected int 401 file_check_mem(struct magic_set *ms, unsigned int level) 402 { 403 size_t len; 404 405 if (level >= ms->c.len) { 406 len = (ms->c.len += 20) * sizeof(*ms->c.li); 407 ms->c.li = CAST(struct level_info *, (ms->c.li == NULL) ? 408 malloc(len) : 409 realloc(ms->c.li, len)); 410 if (ms->c.li == NULL) { 411 file_oomem(ms, len); 412 return -1; 413 } 414 } 415 ms->c.li[level].got_match = 0; 416 #ifdef ENABLE_CONDITIONALS 417 ms->c.li[level].last_match = 0; 418 ms->c.li[level].last_cond = COND_NONE; 419 #endif /* ENABLE_CONDITIONALS */ 420 return 0; 421 } 422 423 protected size_t 424 file_printedlen(const struct magic_set *ms) 425 { 426 return ms->o.buf == NULL ? 0 : strlen(ms->o.buf); 427 } 428 429 protected int 430 file_replace(struct magic_set *ms, const char *pat, const char *rep) 431 { 432 file_regex_t rx; 433 int rc, rv = -1; 434 435 rc = file_regcomp(&rx, pat, REG_EXTENDED); 436 if (rc) { 437 file_regerror(&rx, rc, ms); 438 } else { 439 regmatch_t rm; 440 int nm = 0; 441 while (file_regexec(&rx, ms->o.buf, 1, &rm, 0) == 0) { 442 ms->o.buf[rm.rm_so] = '\0'; 443 if (file_printf(ms, "%s%s", rep, 444 rm.rm_eo != 0 ? ms->o.buf + rm.rm_eo : "") == -1) 445 goto out; 446 nm++; 447 } 448 rv = nm; 449 } 450 out: 451 file_regfree(&rx); 452 return rv; 453 } 454 455 protected int 456 file_regcomp(file_regex_t *rx, const char *pat, int flags) 457 { 458 rx->old_lc_ctype = setlocale(LC_CTYPE, NULL); 459 assert(rx->old_lc_ctype != NULL); 460 rx->old_lc_ctype = strdup(rx->old_lc_ctype); 461 assert(rx->old_lc_ctype != NULL); 462 rx->pat = pat; 463 464 (void)setlocale(LC_CTYPE, "C"); 465 return rx->rc = regcomp(&rx->rx, pat, flags); 466 } 467 468 protected int 469 file_regexec(file_regex_t *rx, const char *str, size_t nmatch, 470 regmatch_t* pmatch, int eflags) 471 { 472 assert(rx->rc == 0); 473 return regexec(&rx->rx, str, nmatch, pmatch, eflags); 474 } 475 476 protected void 477 file_regfree(file_regex_t *rx) 478 { 479 if (rx->rc == 0) 480 regfree(&rx->rx); 481 (void)setlocale(LC_CTYPE, rx->old_lc_ctype); 482 free(rx->old_lc_ctype); 483 } 484 485 protected void 486 file_regerror(file_regex_t *rx, int rc, struct magic_set *ms) 487 { 488 char errmsg[512]; 489 490 (void)regerror(rc, &rx->rx, errmsg, sizeof(errmsg)); 491 file_magerror(ms, "regex error %d for `%s', (%s)", rc, rx->pat, 492 errmsg); 493 } 494