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 1.70 2014/03/14 19:02:37 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 #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 done_encoding: 284 free(u8buf); 285 if (rv) 286 return rv; 287 288 return m; 289 } 290 #endif 291 292 protected int 293 file_reset(struct magic_set *ms) 294 { 295 if (ms->mlist[0] == NULL) { 296 file_error(ms, 0, "no magic files loaded"); 297 return -1; 298 } 299 if (ms->o.buf) { 300 free(ms->o.buf); 301 ms->o.buf = NULL; 302 } 303 if (ms->o.pbuf) { 304 free(ms->o.pbuf); 305 ms->o.pbuf = NULL; 306 } 307 ms->event_flags &= ~EVENT_HAD_ERR; 308 ms->error = -1; 309 return 0; 310 } 311 312 #define OCTALIFY(n, o) \ 313 /*LINTED*/ \ 314 (void)(*(n)++ = '\\', \ 315 *(n)++ = (((uint32_t)*(o) >> 6) & 3) + '0', \ 316 *(n)++ = (((uint32_t)*(o) >> 3) & 7) + '0', \ 317 *(n)++ = (((uint32_t)*(o) >> 0) & 7) + '0', \ 318 (o)++) 319 320 protected const char * 321 file_getbuffer(struct magic_set *ms) 322 { 323 char *pbuf, *op, *np; 324 size_t psize, len; 325 326 if (ms->event_flags & EVENT_HAD_ERR) 327 return NULL; 328 329 if (ms->flags & MAGIC_RAW) 330 return ms->o.buf; 331 332 if (ms->o.buf == NULL) 333 return NULL; 334 335 /* * 4 is for octal representation, + 1 is for NUL */ 336 len = strlen(ms->o.buf); 337 if (len > (SIZE_MAX - 1) / 4) { 338 file_oomem(ms, len); 339 return NULL; 340 } 341 psize = len * 4 + 1; 342 if ((pbuf = CAST(char *, realloc(ms->o.pbuf, psize))) == NULL) { 343 file_oomem(ms, psize); 344 return NULL; 345 } 346 ms->o.pbuf = pbuf; 347 348 #if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH) 349 { 350 mbstate_t state; 351 wchar_t nextchar; 352 int mb_conv = 1; 353 size_t bytesconsumed; 354 char *eop; 355 (void)memset(&state, 0, sizeof(mbstate_t)); 356 357 np = ms->o.pbuf; 358 op = ms->o.buf; 359 eop = op + len; 360 361 while (op < eop) { 362 bytesconsumed = mbrtowc(&nextchar, op, 363 (size_t)(eop - op), &state); 364 if (bytesconsumed == (size_t)(-1) || 365 bytesconsumed == (size_t)(-2)) { 366 mb_conv = 0; 367 break; 368 } 369 370 if (iswprint(nextchar)) { 371 (void)memcpy(np, op, bytesconsumed); 372 op += bytesconsumed; 373 np += bytesconsumed; 374 } else { 375 while (bytesconsumed-- > 0) 376 OCTALIFY(np, op); 377 } 378 } 379 *np = '\0'; 380 381 /* Parsing succeeded as a multi-byte sequence */ 382 if (mb_conv != 0) 383 return ms->o.pbuf; 384 } 385 #endif 386 387 for (np = ms->o.pbuf, op = ms->o.buf; *op;) { 388 if (isprint((unsigned char)*op)) { 389 *np++ = *op++; 390 } else { 391 OCTALIFY(np, op); 392 } 393 } 394 *np = '\0'; 395 return ms->o.pbuf; 396 } 397 398 protected int 399 file_check_mem(struct magic_set *ms, unsigned int level) 400 { 401 size_t len; 402 403 if (level >= ms->c.len) { 404 len = (ms->c.len += 20) * sizeof(*ms->c.li); 405 ms->c.li = CAST(struct level_info *, (ms->c.li == NULL) ? 406 malloc(len) : 407 realloc(ms->c.li, len)); 408 if (ms->c.li == NULL) { 409 file_oomem(ms, len); 410 return -1; 411 } 412 } 413 ms->c.li[level].got_match = 0; 414 #ifdef ENABLE_CONDITIONALS 415 ms->c.li[level].last_match = 0; 416 ms->c.li[level].last_cond = COND_NONE; 417 #endif /* ENABLE_CONDITIONALS */ 418 return 0; 419 } 420 421 protected size_t 422 file_printedlen(const struct magic_set *ms) 423 { 424 return ms->o.buf == NULL ? 0 : strlen(ms->o.buf); 425 } 426 427 protected int 428 file_replace(struct magic_set *ms, const char *pat, const char *rep) 429 { 430 regex_t rx; 431 int rc, rv = -1; 432 char *old_lc_ctype; 433 434 old_lc_ctype = setlocale(LC_CTYPE, NULL); 435 assert(old_lc_ctype != NULL); 436 old_lc_ctype = strdup(old_lc_ctype); 437 assert(old_lc_ctype != NULL); 438 (void)setlocale(LC_CTYPE, "C"); 439 rc = regcomp(&rx, pat, REG_EXTENDED); 440 if (rc) { 441 char errmsg[512]; 442 (void)regerror(rc, &rx, errmsg, sizeof(errmsg)); 443 file_magerror(ms, "regex error %d, (%s)", rc, errmsg); 444 } else { 445 regmatch_t rm; 446 int nm = 0; 447 while (regexec(&rx, ms->o.buf, 1, &rm, 0) == 0) { 448 ms->o.buf[rm.rm_so] = '\0'; 449 if (file_printf(ms, "%s%s", rep, 450 rm.rm_eo != 0 ? ms->o.buf + rm.rm_eo : "") == -1) 451 goto out; 452 nm++; 453 } 454 regfree(&rx); 455 rv = nm; 456 } 457 out: 458 (void)setlocale(LC_CTYPE, old_lc_ctype); 459 free(old_lc_ctype); 460 return rv; 461 } 462