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 1.83 2015/06/16 14:17:37 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 49 #ifndef SIZE_MAX 50 #define SIZE_MAX ((size_t)~0) 51 #endif 52 53 /* 54 * Like printf, only we append to a buffer. 55 */ 56 protected int 57 file_vprintf(struct magic_set *ms, const char *fmt, va_list ap) 58 { 59 int len; 60 char *buf, *newstr; 61 62 if (ms->event_flags & EVENT_HAD_ERR) 63 return 0; 64 len = vasprintf(&buf, fmt, ap); 65 if (len < 0) 66 goto out; 67 68 if (ms->o.buf != NULL) { 69 len = asprintf(&newstr, "%s%s", ms->o.buf, buf); 70 free(buf); 71 if (len < 0) 72 goto out; 73 free(ms->o.buf); 74 buf = newstr; 75 } 76 ms->o.buf = buf; 77 return 0; 78 out: 79 file_error(ms, errno, "vasprintf failed"); 80 return -1; 81 } 82 83 protected int 84 file_printf(struct magic_set *ms, const char *fmt, ...) 85 { 86 int rv; 87 va_list ap; 88 89 va_start(ap, fmt); 90 rv = file_vprintf(ms, fmt, ap); 91 va_end(ap); 92 return rv; 93 } 94 95 /* 96 * error - print best error message possible 97 */ 98 /*VARARGS*/ 99 __attribute__((__format__(__printf__, 3, 0))) 100 private void 101 file_error_core(struct magic_set *ms, int error, const char *f, va_list va, 102 size_t lineno) 103 { 104 /* Only the first error is ok */ 105 if (ms->event_flags & EVENT_HAD_ERR) 106 return; 107 if (lineno != 0) { 108 free(ms->o.buf); 109 ms->o.buf = NULL; 110 file_printf(ms, "line %" SIZE_T_FORMAT "u:", lineno); 111 } 112 if (ms->o.buf && *ms->o.buf) 113 file_printf(ms, " "); 114 file_vprintf(ms, f, va); 115 if (error > 0) 116 file_printf(ms, " (%s)", strerror(error)); 117 ms->event_flags |= EVENT_HAD_ERR; 118 ms->error = error; 119 } 120 121 /*VARARGS*/ 122 protected void 123 file_error(struct magic_set *ms, int error, const char *f, ...) 124 { 125 va_list va; 126 va_start(va, f); 127 file_error_core(ms, error, f, va, 0); 128 va_end(va); 129 } 130 131 /* 132 * Print an error with magic line number. 133 */ 134 /*VARARGS*/ 135 protected void 136 file_magerror(struct magic_set *ms, const char *f, ...) 137 { 138 va_list va; 139 va_start(va, f); 140 file_error_core(ms, 0, f, va, ms->line); 141 va_end(va); 142 } 143 144 protected void 145 file_oomem(struct magic_set *ms, size_t len) 146 { 147 file_error(ms, errno, "cannot allocate %" SIZE_T_FORMAT "u bytes", 148 len); 149 } 150 151 protected void 152 file_badseek(struct magic_set *ms) 153 { 154 file_error(ms, errno, "error seeking"); 155 } 156 157 protected void 158 file_badread(struct magic_set *ms) 159 { 160 file_error(ms, errno, "error reading"); 161 } 162 163 #ifndef COMPILE_ONLY 164 165 static int 166 checkdone(struct magic_set *ms, int *rv) 167 { 168 if ((ms->flags & MAGIC_CONTINUE) == 0) 169 return 1; 170 if (file_printf(ms, "\n- ") == -1) 171 *rv = -1; 172 return 0; 173 } 174 175 /*ARGSUSED*/ 176 protected int 177 file_buffer(struct magic_set *ms, int fd, const char *inname __attribute__ ((__unused__)), 178 const void *buf, size_t nb) 179 { 180 int m = 0, rv = 0, looks_text = 0; 181 int mime = ms->flags & MAGIC_MIME; 182 const unsigned char *ubuf = CAST(const unsigned char *, buf); 183 unichar *u8buf = NULL; 184 size_t ulen; 185 const char *code = NULL; 186 const char *code_mime = "binary"; 187 const char *type = "application/octet-stream"; 188 const char *def = "data"; 189 const char *ftype = NULL; 190 191 if (nb == 0) { 192 def = "empty"; 193 type = "application/x-empty"; 194 goto simple; 195 } else if (nb == 1) { 196 def = "very short file (no magic)"; 197 goto simple; 198 } 199 200 if ((ms->flags & MAGIC_NO_CHECK_ENCODING) == 0) { 201 looks_text = file_encoding(ms, ubuf, nb, &u8buf, &ulen, 202 &code, &code_mime, &ftype); 203 } 204 205 #ifdef __EMX__ 206 if ((ms->flags & MAGIC_NO_CHECK_APPTYPE) == 0 && inname) { 207 switch (file_os2_apptype(ms, inname, buf, nb)) { 208 case -1: 209 return -1; 210 case 0: 211 break; 212 default: 213 return 1; 214 } 215 } 216 #endif 217 #if HAVE_FORK 218 /* try compression stuff */ 219 if ((ms->flags & MAGIC_NO_CHECK_COMPRESS) == 0) 220 if ((m = file_zmagic(ms, fd, inname, ubuf, nb)) != 0) { 221 if ((ms->flags & MAGIC_DEBUG) != 0) 222 (void)fprintf(stderr, "zmagic %d\n", m); 223 goto done_encoding; 224 } 225 #endif 226 /* Check if we have a tar file */ 227 if ((ms->flags & MAGIC_NO_CHECK_TAR) == 0) 228 if ((m = file_is_tar(ms, ubuf, nb)) != 0) { 229 if ((ms->flags & MAGIC_DEBUG) != 0) 230 (void)fprintf(stderr, "tar %d\n", m); 231 if (checkdone(ms, &rv)) 232 goto done; 233 } 234 235 /* Check if we have a CDF file */ 236 if ((ms->flags & MAGIC_NO_CHECK_CDF) == 0) 237 if ((m = file_trycdf(ms, fd, ubuf, nb)) != 0) { 238 if ((ms->flags & MAGIC_DEBUG) != 0) 239 (void)fprintf(stderr, "cdf %d\n", m); 240 if (checkdone(ms, &rv)) 241 goto done; 242 } 243 244 /* try soft magic tests */ 245 if ((ms->flags & MAGIC_NO_CHECK_SOFT) == 0) 246 if ((m = file_softmagic(ms, ubuf, nb, 0, NULL, BINTEST, 247 looks_text)) != 0) { 248 if ((ms->flags & MAGIC_DEBUG) != 0) 249 (void)fprintf(stderr, "softmagic %d\n", m); 250 #ifdef BUILTIN_ELF 251 if ((ms->flags & MAGIC_NO_CHECK_ELF) == 0 && m == 1 && 252 nb > 5 && fd != -1) { 253 /* 254 * We matched something in the file, so this 255 * *might* be an ELF file, and the file is at 256 * least 5 bytes long, so if it's an ELF file 257 * it has at least one byte past the ELF magic 258 * number - try extracting information from the 259 * ELF headers that cannot easily * be 260 * extracted with rules in the magic file. 261 */ 262 if ((m = file_tryelf(ms, fd, ubuf, nb)) != 0) 263 if ((ms->flags & MAGIC_DEBUG) != 0) 264 (void)fprintf(stderr, 265 "elf %d\n", m); 266 } 267 #endif 268 if (checkdone(ms, &rv)) 269 goto done; 270 } 271 272 /* try text properties */ 273 if ((ms->flags & MAGIC_NO_CHECK_TEXT) == 0) { 274 275 if ((m = file_ascmagic(ms, ubuf, nb, looks_text)) != 0) { 276 if ((ms->flags & MAGIC_DEBUG) != 0) 277 (void)fprintf(stderr, "ascmagic %d\n", m); 278 if (checkdone(ms, &rv)) 279 goto done; 280 } 281 } 282 283 simple: 284 /* give up */ 285 m = 1; 286 if ((!mime || (mime & MAGIC_MIME_TYPE)) && 287 file_printf(ms, "%s", mime ? type : def) == -1) { 288 rv = -1; 289 } 290 done: 291 if ((ms->flags & MAGIC_MIME_ENCODING) != 0) { 292 if (ms->flags & MAGIC_MIME_TYPE) 293 if (file_printf(ms, "; charset=") == -1) 294 rv = -1; 295 if (file_printf(ms, "%s", code_mime) == -1) 296 rv = -1; 297 } 298 #if HAVE_FORK 299 done_encoding: 300 #endif 301 free(u8buf); 302 if (rv) 303 return rv; 304 305 return m; 306 } 307 #endif 308 309 protected int 310 file_reset(struct magic_set *ms) 311 { 312 if (ms->mlist[0] == NULL) { 313 file_error(ms, 0, "no magic files loaded"); 314 return -1; 315 } 316 if (ms->o.buf) { 317 free(ms->o.buf); 318 ms->o.buf = NULL; 319 } 320 if (ms->o.pbuf) { 321 free(ms->o.pbuf); 322 ms->o.pbuf = NULL; 323 } 324 ms->event_flags &= ~EVENT_HAD_ERR; 325 ms->error = -1; 326 return 0; 327 } 328 329 #define OCTALIFY(n, o) \ 330 /*LINTED*/ \ 331 (void)(*(n)++ = '\\', \ 332 *(n)++ = (((uint32_t)*(o) >> 6) & 3) + '0', \ 333 *(n)++ = (((uint32_t)*(o) >> 3) & 7) + '0', \ 334 *(n)++ = (((uint32_t)*(o) >> 0) & 7) + '0', \ 335 (o)++) 336 337 protected const char * 338 file_getbuffer(struct magic_set *ms) 339 { 340 char *pbuf, *op, *np; 341 size_t psize, len; 342 343 if (ms->event_flags & EVENT_HAD_ERR) 344 return NULL; 345 346 if (ms->flags & MAGIC_RAW) 347 return ms->o.buf; 348 349 if (ms->o.buf == NULL) 350 return NULL; 351 352 /* * 4 is for octal representation, + 1 is for NUL */ 353 len = strlen(ms->o.buf); 354 if (len > (SIZE_MAX - 1) / 4) { 355 file_oomem(ms, len); 356 return NULL; 357 } 358 psize = len * 4 + 1; 359 if ((pbuf = CAST(char *, realloc(ms->o.pbuf, psize))) == NULL) { 360 file_oomem(ms, psize); 361 return NULL; 362 } 363 ms->o.pbuf = pbuf; 364 365 #if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH) 366 { 367 mbstate_t state; 368 wchar_t nextchar; 369 int mb_conv = 1; 370 size_t bytesconsumed; 371 char *eop; 372 (void)memset(&state, 0, sizeof(mbstate_t)); 373 374 np = ms->o.pbuf; 375 op = ms->o.buf; 376 eop = op + len; 377 378 while (op < eop) { 379 bytesconsumed = mbrtowc(&nextchar, op, 380 (size_t)(eop - op), &state); 381 if (bytesconsumed == (size_t)(-1) || 382 bytesconsumed == (size_t)(-2)) { 383 mb_conv = 0; 384 break; 385 } 386 387 if (iswprint(nextchar)) { 388 (void)memcpy(np, op, bytesconsumed); 389 op += bytesconsumed; 390 np += bytesconsumed; 391 } else { 392 while (bytesconsumed-- > 0) 393 OCTALIFY(np, op); 394 } 395 } 396 *np = '\0'; 397 398 /* Parsing succeeded as a multi-byte sequence */ 399 if (mb_conv != 0) 400 return ms->o.pbuf; 401 } 402 #endif 403 404 for (np = ms->o.pbuf, op = ms->o.buf; *op;) { 405 if (isprint((unsigned char)*op)) { 406 *np++ = *op++; 407 } else { 408 OCTALIFY(np, op); 409 } 410 } 411 *np = '\0'; 412 return ms->o.pbuf; 413 } 414 415 protected int 416 file_check_mem(struct magic_set *ms, unsigned int level) 417 { 418 size_t len; 419 420 if (level >= ms->c.len) { 421 len = (ms->c.len = 20 + level) * sizeof(*ms->c.li); 422 ms->c.li = CAST(struct level_info *, (ms->c.li == NULL) ? 423 malloc(len) : 424 realloc(ms->c.li, len)); 425 if (ms->c.li == NULL) { 426 file_oomem(ms, len); 427 return -1; 428 } 429 } 430 ms->c.li[level].got_match = 0; 431 #ifdef ENABLE_CONDITIONALS 432 ms->c.li[level].last_match = 0; 433 ms->c.li[level].last_cond = COND_NONE; 434 #endif /* ENABLE_CONDITIONALS */ 435 return 0; 436 } 437 438 protected size_t 439 file_printedlen(const struct magic_set *ms) 440 { 441 return ms->o.buf == NULL ? 0 : strlen(ms->o.buf); 442 } 443 444 protected int 445 file_replace(struct magic_set *ms, const char *pat, const char *rep) 446 { 447 file_regex_t rx; 448 int rc, rv = -1; 449 450 rc = file_regcomp(&rx, pat, REG_EXTENDED); 451 if (rc) { 452 file_regerror(&rx, rc, ms); 453 } else { 454 regmatch_t rm; 455 int nm = 0; 456 while (file_regexec(&rx, ms->o.buf, 1, &rm, 0) == 0) { 457 ms->o.buf[rm.rm_so] = '\0'; 458 if (file_printf(ms, "%s%s", rep, 459 rm.rm_eo != 0 ? ms->o.buf + rm.rm_eo : "") == -1) 460 goto out; 461 nm++; 462 } 463 rv = nm; 464 } 465 out: 466 file_regfree(&rx); 467 return rv; 468 } 469 470 protected int 471 file_regcomp(file_regex_t *rx, const char *pat, int flags) 472 { 473 #ifdef USE_C_LOCALE 474 rx->c_lc_ctype = newlocale(LC_CTYPE_MASK, "C", 0); 475 assert(rx->c_lc_ctype != NULL); 476 rx->old_lc_ctype = uselocale(rx->c_lc_ctype); 477 assert(rx->old_lc_ctype != NULL); 478 #endif 479 rx->pat = pat; 480 481 return rx->rc = regcomp(&rx->rx, pat, flags); 482 } 483 484 protected int 485 file_regexec(file_regex_t *rx, const char *str, size_t nmatch, 486 regmatch_t* pmatch, int eflags) 487 { 488 assert(rx->rc == 0); 489 return regexec(&rx->rx, str, nmatch, pmatch, eflags); 490 } 491 492 protected void 493 file_regfree(file_regex_t *rx) 494 { 495 if (rx->rc == 0) 496 regfree(&rx->rx); 497 #ifdef USE_C_LOCALE 498 (void)uselocale(rx->old_lc_ctype); 499 freelocale(rx->c_lc_ctype); 500 #endif 501 } 502 503 protected void 504 file_regerror(file_regex_t *rx, int rc, struct magic_set *ms) 505 { 506 char errmsg[512]; 507 508 (void)regerror(rc, &rx->rx, errmsg, sizeof(errmsg)); 509 file_magerror(ms, "regex error %d for `%s', (%s)", rc, rx->pat, 510 errmsg); 511 } 512 513 protected file_pushbuf_t * 514 file_push_buffer(struct magic_set *ms) 515 { 516 file_pushbuf_t *pb; 517 518 if (ms->event_flags & EVENT_HAD_ERR) 519 return NULL; 520 521 if ((pb = (CAST(file_pushbuf_t *, malloc(sizeof(*pb))))) == NULL) 522 return NULL; 523 524 pb->buf = ms->o.buf; 525 pb->offset = ms->offset; 526 527 ms->o.buf = NULL; 528 ms->offset = 0; 529 530 return pb; 531 } 532 533 protected char * 534 file_pop_buffer(struct magic_set *ms, file_pushbuf_t *pb) 535 { 536 char *rbuf; 537 538 if (ms->event_flags & EVENT_HAD_ERR) { 539 free(pb->buf); 540 free(pb); 541 return NULL; 542 } 543 544 rbuf = ms->o.buf; 545 546 ms->o.buf = pb->buf; 547 ms->offset = pb->offset; 548 549 free(pb); 550 return rbuf; 551 } 552 553 /* 554 * convert string to ascii printable format. 555 */ 556 protected char * 557 file_printable(char *buf, size_t bufsiz, const char *str) 558 { 559 char *ptr, *eptr; 560 const unsigned char *s = (const unsigned char *)str; 561 562 for (ptr = buf, eptr = ptr + bufsiz - 1; ptr < eptr && *s; s++) { 563 if (isprint(*s)) { 564 *ptr++ = *s; 565 continue; 566 } 567 if (ptr >= eptr - 3) 568 break; 569 *ptr++ = '\\'; 570 *ptr++ = ((CAST(unsigned int, *s) >> 6) & 7) + '0'; 571 *ptr++ = ((CAST(unsigned int, *s) >> 3) & 7) + '0'; 572 *ptr++ = ((CAST(unsigned int, *s) >> 0) & 7) + '0'; 573 } 574 *ptr = '\0'; 575 return buf; 576 } 577