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 1.94 2017/11/02 20:25:39 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 fprintf(stderr, "vasprintf failed (%s)", strerror(errno)); 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 const char *code = NULL; 182 const char *code_mime = "binary"; 183 const char *type = "application/octet-stream"; 184 const char *def = "data"; 185 const char *ftype = NULL; 186 struct buffer b; 187 188 buffer_init(&b, fd, buf, nb); 189 190 if (nb == 0) { 191 def = "empty"; 192 type = "application/x-empty"; 193 goto simple; 194 } else if (nb == 1) { 195 def = "very short file (no magic)"; 196 goto simple; 197 } 198 199 if ((ms->flags & MAGIC_NO_CHECK_ENCODING) == 0) { 200 looks_text = file_encoding(ms, &b, NULL, 0, 201 &code, &code_mime, &ftype); 202 } 203 204 #ifdef __EMX__ 205 if ((ms->flags & MAGIC_NO_CHECK_APPTYPE) == 0 && inname) { 206 m = file_os2_apptype(ms, inname, &b); 207 if ((ms->flags & MAGIC_DEBUG) != 0) 208 (void)fprintf(stderr, "[try os2_apptype %d]\n", m); 209 switch (m) { 210 case -1: 211 return -1; 212 case 0: 213 break; 214 default: 215 return 1; 216 } 217 } 218 #endif 219 #if HAVE_FORK 220 /* try compression stuff */ 221 if ((ms->flags & MAGIC_NO_CHECK_COMPRESS) == 0) { 222 m = file_zmagic(ms, &b, inname); 223 if ((ms->flags & MAGIC_DEBUG) != 0) 224 (void)fprintf(stderr, "[try zmagic %d]\n", m); 225 if (m) { 226 goto done_encoding; 227 } 228 } 229 #endif 230 /* Check if we have a tar file */ 231 if ((ms->flags & MAGIC_NO_CHECK_TAR) == 0) { 232 m = file_is_tar(ms, &b); 233 if ((ms->flags & MAGIC_DEBUG) != 0) 234 (void)fprintf(stderr, "[try tar %d]\n", m); 235 if (m) { 236 if (checkdone(ms, &rv)) 237 goto done; 238 } 239 } 240 241 /* Check if we have a CDF file */ 242 if ((ms->flags & MAGIC_NO_CHECK_CDF) == 0) { 243 m = file_trycdf(ms, &b); 244 if ((ms->flags & MAGIC_DEBUG) != 0) 245 (void)fprintf(stderr, "[try cdf %d]\n", m); 246 if (m) { 247 if (checkdone(ms, &rv)) 248 goto done; 249 } 250 } 251 252 /* try soft magic tests */ 253 if ((ms->flags & MAGIC_NO_CHECK_SOFT) == 0) { 254 m = file_softmagic(ms, &b, NULL, NULL, BINTEST, looks_text); 255 if ((ms->flags & MAGIC_DEBUG) != 0) 256 (void)fprintf(stderr, "[try softmagic %d]\n", m); 257 if (m) { 258 #ifdef BUILTIN_ELF 259 if ((ms->flags & MAGIC_NO_CHECK_ELF) == 0 && m == 1 && 260 nb > 5 && fd != -1) { 261 /* 262 * We matched something in the file, so this 263 * *might* be an ELF file, and the file is at 264 * least 5 bytes long, so if it's an ELF file 265 * it has at least one byte past the ELF magic 266 * number - try extracting information from the 267 * ELF headers that cannot easily * be 268 * extracted with rules in the magic file. 269 */ 270 m = file_tryelf(ms, &b); 271 if ((ms->flags & MAGIC_DEBUG) != 0) 272 (void)fprintf(stderr, "[try elf %d]\n", 273 m); 274 } 275 #endif 276 if (checkdone(ms, &rv)) 277 goto done; 278 } 279 } 280 281 /* try text properties */ 282 if ((ms->flags & MAGIC_NO_CHECK_TEXT) == 0) { 283 284 m = file_ascmagic(ms, &b, looks_text); 285 if ((ms->flags & MAGIC_DEBUG) != 0) 286 (void)fprintf(stderr, "[try ascmagic %d]\n", m); 287 if (m) { 288 if (checkdone(ms, &rv)) 289 goto done; 290 } 291 } 292 293 simple: 294 /* give up */ 295 m = 1; 296 if (ms->flags & MAGIC_MIME) { 297 if ((ms->flags & MAGIC_MIME_TYPE) && 298 file_printf(ms, "%s", type) == -1) 299 rv = -1; 300 } else if (ms->flags & MAGIC_APPLE) { 301 if (file_printf(ms, "UNKNUNKN") == -1) 302 rv = -1; 303 } else if (ms->flags & MAGIC_EXTENSION) { 304 if (file_printf(ms, "???") == -1) 305 rv = -1; 306 } else { 307 if (file_printf(ms, "%s", def) == -1) 308 rv = -1; 309 } 310 done: 311 if ((ms->flags & MAGIC_MIME_ENCODING) != 0) { 312 if (ms->flags & MAGIC_MIME_TYPE) 313 if (file_printf(ms, "; charset=") == -1) 314 rv = -1; 315 if (file_printf(ms, "%s", code_mime) == -1) 316 rv = -1; 317 } 318 #if HAVE_FORK 319 done_encoding: 320 #endif 321 buffer_fini(&b); 322 if (rv) 323 return rv; 324 325 return m; 326 } 327 #endif 328 329 protected int 330 file_reset(struct magic_set *ms, int checkloaded) 331 { 332 if (checkloaded && ms->mlist[0] == NULL) { 333 file_error(ms, 0, "no magic files loaded"); 334 return -1; 335 } 336 if (ms->o.buf) { 337 free(ms->o.buf); 338 ms->o.buf = NULL; 339 } 340 if (ms->o.pbuf) { 341 free(ms->o.pbuf); 342 ms->o.pbuf = NULL; 343 } 344 ms->event_flags &= ~EVENT_HAD_ERR; 345 ms->error = -1; 346 return 0; 347 } 348 349 #define OCTALIFY(n, o) \ 350 /*LINTED*/ \ 351 (void)(*(n)++ = '\\', \ 352 *(n)++ = (((uint32_t)*(o) >> 6) & 3) + '0', \ 353 *(n)++ = (((uint32_t)*(o) >> 3) & 7) + '0', \ 354 *(n)++ = (((uint32_t)*(o) >> 0) & 7) + '0', \ 355 (o)++) 356 357 protected const char * 358 file_getbuffer(struct magic_set *ms) 359 { 360 char *pbuf, *op, *np; 361 size_t psize, len; 362 363 if (ms->event_flags & EVENT_HAD_ERR) 364 return NULL; 365 366 if (ms->flags & MAGIC_RAW) 367 return ms->o.buf; 368 369 if (ms->o.buf == NULL) 370 return NULL; 371 372 /* * 4 is for octal representation, + 1 is for NUL */ 373 len = strlen(ms->o.buf); 374 if (len > (SIZE_MAX - 1) / 4) { 375 file_oomem(ms, len); 376 return NULL; 377 } 378 psize = len * 4 + 1; 379 if ((pbuf = CAST(char *, realloc(ms->o.pbuf, psize))) == NULL) { 380 file_oomem(ms, psize); 381 return NULL; 382 } 383 ms->o.pbuf = pbuf; 384 385 #if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH) 386 { 387 mbstate_t state; 388 wchar_t nextchar; 389 int mb_conv = 1; 390 size_t bytesconsumed; 391 char *eop; 392 (void)memset(&state, 0, sizeof(mbstate_t)); 393 394 np = ms->o.pbuf; 395 op = ms->o.buf; 396 eop = op + len; 397 398 while (op < eop) { 399 bytesconsumed = mbrtowc(&nextchar, op, 400 (size_t)(eop - op), &state); 401 if (bytesconsumed == (size_t)(-1) || 402 bytesconsumed == (size_t)(-2)) { 403 mb_conv = 0; 404 break; 405 } 406 407 if (iswprint(nextchar)) { 408 (void)memcpy(np, op, bytesconsumed); 409 op += bytesconsumed; 410 np += bytesconsumed; 411 } else { 412 while (bytesconsumed-- > 0) 413 OCTALIFY(np, op); 414 } 415 } 416 *np = '\0'; 417 418 /* Parsing succeeded as a multi-byte sequence */ 419 if (mb_conv != 0) 420 return ms->o.pbuf; 421 } 422 #endif 423 424 for (np = ms->o.pbuf, op = ms->o.buf; *op;) { 425 if (isprint((unsigned char)*op)) { 426 *np++ = *op++; 427 } else { 428 OCTALIFY(np, op); 429 } 430 } 431 *np = '\0'; 432 return ms->o.pbuf; 433 } 434 435 protected int 436 file_check_mem(struct magic_set *ms, unsigned int level) 437 { 438 size_t len; 439 440 if (level >= ms->c.len) { 441 len = (ms->c.len = 20 + level) * sizeof(*ms->c.li); 442 ms->c.li = CAST(struct level_info *, (ms->c.li == NULL) ? 443 malloc(len) : 444 realloc(ms->c.li, len)); 445 if (ms->c.li == NULL) { 446 file_oomem(ms, len); 447 return -1; 448 } 449 } 450 ms->c.li[level].got_match = 0; 451 #ifdef ENABLE_CONDITIONALS 452 ms->c.li[level].last_match = 0; 453 ms->c.li[level].last_cond = COND_NONE; 454 #endif /* ENABLE_CONDITIONALS */ 455 return 0; 456 } 457 458 protected size_t 459 file_printedlen(const struct magic_set *ms) 460 { 461 return ms->o.buf == NULL ? 0 : strlen(ms->o.buf); 462 } 463 464 protected int 465 file_replace(struct magic_set *ms, const char *pat, const char *rep) 466 { 467 file_regex_t rx; 468 int rc, rv = -1; 469 470 rc = file_regcomp(&rx, pat, REG_EXTENDED); 471 if (rc) { 472 file_regerror(&rx, rc, ms); 473 } else { 474 regmatch_t rm; 475 int nm = 0; 476 while (file_regexec(&rx, ms->o.buf, 1, &rm, 0) == 0) { 477 ms->o.buf[rm.rm_so] = '\0'; 478 if (file_printf(ms, "%s%s", rep, 479 rm.rm_eo != 0 ? ms->o.buf + rm.rm_eo : "") == -1) 480 goto out; 481 nm++; 482 } 483 rv = nm; 484 } 485 out: 486 file_regfree(&rx); 487 return rv; 488 } 489 490 protected int 491 file_regcomp(file_regex_t *rx, const char *pat, int flags) 492 { 493 #ifdef USE_C_LOCALE 494 rx->c_lc_ctype = newlocale(LC_CTYPE_MASK, "C", 0); 495 assert(rx->c_lc_ctype != NULL); 496 rx->old_lc_ctype = uselocale(rx->c_lc_ctype); 497 assert(rx->old_lc_ctype != NULL); 498 #else 499 rx->old_lc_ctype = setlocale(LC_CTYPE, "C"); 500 #endif 501 rx->pat = pat; 502 503 return rx->rc = regcomp(&rx->rx, pat, flags); 504 } 505 506 protected int 507 file_regexec(file_regex_t *rx, const char *str, size_t nmatch, 508 regmatch_t* pmatch, int eflags) 509 { 510 assert(rx->rc == 0); 511 /* XXX: force initialization because glibc does not always do this */ 512 memset(pmatch, 0, nmatch * sizeof(*pmatch)); 513 return regexec(&rx->rx, str, nmatch, pmatch, eflags); 514 } 515 516 protected void 517 file_regfree(file_regex_t *rx) 518 { 519 if (rx->rc == 0) 520 regfree(&rx->rx); 521 #ifdef USE_C_LOCALE 522 (void)uselocale(rx->old_lc_ctype); 523 freelocale(rx->c_lc_ctype); 524 #else 525 (void)setlocale(LC_CTYPE, rx->old_lc_ctype); 526 #endif 527 } 528 529 protected void 530 file_regerror(file_regex_t *rx, int rc, struct magic_set *ms) 531 { 532 char errmsg[512]; 533 534 (void)regerror(rc, &rx->rx, errmsg, sizeof(errmsg)); 535 file_magerror(ms, "regex error %d for `%s', (%s)", rc, rx->pat, 536 errmsg); 537 } 538 539 protected file_pushbuf_t * 540 file_push_buffer(struct magic_set *ms) 541 { 542 file_pushbuf_t *pb; 543 544 if (ms->event_flags & EVENT_HAD_ERR) 545 return NULL; 546 547 if ((pb = (CAST(file_pushbuf_t *, malloc(sizeof(*pb))))) == NULL) 548 return NULL; 549 550 pb->buf = ms->o.buf; 551 pb->offset = ms->offset; 552 553 ms->o.buf = NULL; 554 ms->offset = 0; 555 556 return pb; 557 } 558 559 protected char * 560 file_pop_buffer(struct magic_set *ms, file_pushbuf_t *pb) 561 { 562 char *rbuf; 563 564 if (ms->event_flags & EVENT_HAD_ERR) { 565 free(pb->buf); 566 free(pb); 567 return NULL; 568 } 569 570 rbuf = ms->o.buf; 571 572 ms->o.buf = pb->buf; 573 ms->offset = pb->offset; 574 575 free(pb); 576 return rbuf; 577 } 578 579 /* 580 * convert string to ascii printable format. 581 */ 582 protected char * 583 file_printable(char *buf, size_t bufsiz, const char *str) 584 { 585 char *ptr, *eptr; 586 const unsigned char *s = (const unsigned char *)str; 587 588 for (ptr = buf, eptr = ptr + bufsiz - 1; ptr < eptr && *s; s++) { 589 if (isprint(*s)) { 590 *ptr++ = *s; 591 continue; 592 } 593 if (ptr >= eptr - 3) 594 break; 595 *ptr++ = '\\'; 596 *ptr++ = ((CAST(unsigned int, *s) >> 6) & 7) + '0'; 597 *ptr++ = ((CAST(unsigned int, *s) >> 3) & 7) + '0'; 598 *ptr++ = ((CAST(unsigned int, *s) >> 0) & 7) + '0'; 599 } 600 *ptr = '\0'; 601 return buf; 602 } 603