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 1.54 2009/05/08 17:41:59 christos Exp $") 31 #endif /* lint */ 32 33 #include "magic.h" 34 #include <stdarg.h> 35 #include <stdlib.h> 36 #include <string.h> 37 #include <ctype.h> 38 #if defined(HAVE_WCHAR_H) 39 #include <wchar.h> 40 #endif 41 #if defined(HAVE_WCTYPE_H) 42 #include <wctype.h> 43 #endif 44 #if defined(HAVE_LIMITS_H) 45 #include <limits.h> 46 #endif 47 48 #ifndef SIZE_MAX 49 #define SIZE_MAX ((size_t)~0) 50 #endif 51 52 /* 53 * Like printf, only we append to a buffer. 54 */ 55 protected int 56 file_vprintf(struct magic_set *ms, const char *fmt, va_list ap) 57 { 58 int len; 59 char *buf, *newstr; 60 61 len = vasprintf(&buf, fmt, ap); 62 if (len < 0) 63 goto out; 64 65 if (ms->o.buf != NULL) { 66 len = asprintf(&newstr, "%s%s", ms->o.buf, buf); 67 free(buf); 68 if (len < 0) 69 goto out; 70 free(ms->o.buf); 71 buf = newstr; 72 } 73 ms->o.buf = buf; 74 return 0; 75 out: 76 file_error(ms, errno, "vasprintf failed"); 77 return -1; 78 } 79 80 protected int 81 file_printf(struct magic_set *ms, const char *fmt, ...) 82 { 83 int rv; 84 va_list ap; 85 86 va_start(ap, fmt); 87 rv = file_vprintf(ms, fmt, ap); 88 va_end(ap); 89 return rv; 90 } 91 92 /* 93 * error - print best error message possible 94 */ 95 /*VARARGS*/ 96 private void 97 file_error_core(struct magic_set *ms, int error, const char *f, va_list va, 98 size_t lineno) 99 { 100 /* Only the first error is ok */ 101 if (ms->event_flags & EVENT_HAD_ERR) 102 return; 103 if (lineno != 0) { 104 free(ms->o.buf); 105 ms->o.buf = NULL; 106 file_printf(ms, "line %zu: ", lineno); 107 } 108 file_vprintf(ms, f, va); 109 if (error > 0) 110 file_printf(ms, " (%s)", strerror(error)); 111 ms->event_flags |= EVENT_HAD_ERR; 112 ms->error = error; 113 } 114 115 /*VARARGS*/ 116 protected void 117 file_error(struct magic_set *ms, int error, const char *f, ...) 118 { 119 va_list va; 120 va_start(va, f); 121 file_error_core(ms, error, f, va, 0); 122 va_end(va); 123 } 124 125 /* 126 * Print an error with magic line number. 127 */ 128 /*VARARGS*/ 129 protected void 130 file_magerror(struct magic_set *ms, const char *f, ...) 131 { 132 va_list va; 133 va_start(va, f); 134 file_error_core(ms, 0, f, va, ms->line); 135 va_end(va); 136 } 137 138 protected void 139 file_oomem(struct magic_set *ms, size_t len) 140 { 141 file_error(ms, errno, "cannot allocate %zu bytes", len); 142 } 143 144 protected void 145 file_badseek(struct magic_set *ms) 146 { 147 file_error(ms, errno, "error seeking"); 148 } 149 150 protected void 151 file_badread(struct magic_set *ms) 152 { 153 file_error(ms, errno, "error reading"); 154 } 155 156 #ifndef COMPILE_ONLY 157 protected int 158 file_buffer(struct magic_set *ms, int fd, const char *inname, const void *buf, 159 size_t nb) 160 { 161 int m = 0, rv = 0, looks_text = 0; 162 int mime = ms->flags & MAGIC_MIME; 163 const unsigned char *ubuf = CAST(const unsigned char *, buf); 164 unichar *u8buf = NULL; 165 size_t ulen; 166 const char *code = NULL; 167 const char *code_mime = "binary"; 168 const char *type = NULL; 169 170 171 172 if (nb == 0) { 173 if ((!mime || (mime & MAGIC_MIME_TYPE)) && 174 file_printf(ms, mime ? "application/x-empty" : 175 "empty") == -1) 176 return -1; 177 return 1; 178 } else if (nb == 1) { 179 if ((!mime || (mime & MAGIC_MIME_TYPE)) && 180 file_printf(ms, mime ? "application/octet-stream" : 181 "very short file (no magic)") == -1) 182 return -1; 183 return 1; 184 } 185 186 if ((ms->flags & MAGIC_NO_CHECK_ENCODING) == 0) { 187 looks_text = file_encoding(ms, ubuf, nb, &u8buf, &ulen, 188 &code, &code_mime, &type); 189 } 190 191 #ifdef __EMX__ 192 if ((ms->flags & MAGIC_NO_CHECK_APPTYPE) == 0 && inname) { 193 switch (file_os2_apptype(ms, inname, buf, nb)) { 194 case -1: 195 return -1; 196 case 0: 197 break; 198 default: 199 return 1; 200 } 201 } 202 #endif 203 204 /* try compression stuff */ 205 if ((ms->flags & MAGIC_NO_CHECK_COMPRESS) == 0) 206 if ((m = file_zmagic(ms, fd, inname, ubuf, nb)) != 0) { 207 if ((ms->flags & MAGIC_DEBUG) != 0) 208 (void)fprintf(stderr, "zmagic %d\n", m); 209 goto done; 210 } 211 212 /* Check if we have a tar file */ 213 if ((ms->flags & MAGIC_NO_CHECK_TAR) == 0) 214 if ((m = file_is_tar(ms, ubuf, nb)) != 0) { 215 if ((ms->flags & MAGIC_DEBUG) != 0) 216 (void)fprintf(stderr, "tar %d\n", m); 217 goto done; 218 } 219 220 /* Check if we have a CDF file */ 221 if ((ms->flags & MAGIC_NO_CHECK_CDF) == 0) 222 if ((m = file_trycdf(ms, fd, ubuf, nb)) != 0) { 223 if ((ms->flags & MAGIC_DEBUG) != 0) 224 (void)fprintf(stderr, "cdf %d\n", m); 225 goto done; 226 } 227 228 /* try soft magic tests */ 229 if ((ms->flags & MAGIC_NO_CHECK_SOFT) == 0) 230 if ((m = file_softmagic(ms, ubuf, nb, BINTEST)) != 0) { 231 if ((ms->flags & MAGIC_DEBUG) != 0) 232 (void)fprintf(stderr, "softmagic %d\n", m); 233 #ifdef BUILTIN_ELF 234 if ((ms->flags & MAGIC_NO_CHECK_ELF) == 0 && m == 1 && 235 nb > 5 && fd != -1) { 236 /* 237 * We matched something in the file, so this 238 * *might* be an ELF file, and the file is at 239 * least 5 bytes long, so if it's an ELF file 240 * it has at least one byte past the ELF magic 241 * number - try extracting information from the 242 * ELF headers that cannot easily * be 243 * extracted with rules in the magic file. 244 */ 245 if ((m = file_tryelf(ms, fd, ubuf, nb)) != 0) 246 if ((ms->flags & MAGIC_DEBUG) != 0) 247 (void)fprintf(stderr, 248 "elf %d\n", m); 249 } 250 #endif 251 goto done; 252 } 253 254 /* try text properties (and possibly text tokens) */ 255 if ((ms->flags & MAGIC_NO_CHECK_TEXT) == 0) { 256 257 if ((m = file_ascmagic(ms, ubuf, nb)) != 0) { 258 if ((ms->flags & MAGIC_DEBUG) != 0) 259 (void)fprintf(stderr, "ascmagic %d\n", m); 260 goto done; 261 } 262 263 /* try to discover text encoding */ 264 if ((ms->flags & MAGIC_NO_CHECK_ENCODING) == 0) { 265 if (looks_text == 0) 266 if ((m = file_ascmagic_with_encoding( ms, ubuf, 267 nb, u8buf, ulen, code, type)) != 0) { 268 if ((ms->flags & MAGIC_DEBUG) != 0) 269 (void)fprintf(stderr, 270 "ascmagic/enc %d\n", m); 271 goto done; 272 } 273 } 274 } 275 276 /* give up */ 277 m = 1; 278 if ((!mime || (mime & MAGIC_MIME_TYPE)) && 279 file_printf(ms, mime ? "application/octet-stream" : "data") == -1) { 280 rv = -1; 281 } 282 done: 283 if ((ms->flags & MAGIC_MIME_ENCODING) != 0) { 284 if (ms->flags & MAGIC_MIME_TYPE) 285 if (file_printf(ms, "; charset=") == -1) 286 rv = -1; 287 if (file_printf(ms, "%s", code_mime) == -1) 288 rv = -1; 289 } 290 if (u8buf) 291 free(u8buf); 292 if (rv) 293 return rv; 294 295 return m; 296 } 297 #endif 298 299 protected int 300 file_reset(struct magic_set *ms) 301 { 302 if (ms->mlist == NULL) { 303 file_error(ms, 0, "no magic files loaded"); 304 return -1; 305 } 306 if (ms->o.buf) { 307 free(ms->o.buf); 308 ms->o.buf = NULL; 309 } 310 if (ms->o.pbuf) { 311 free(ms->o.pbuf); 312 ms->o.pbuf = NULL; 313 } 314 ms->event_flags &= ~EVENT_HAD_ERR; 315 ms->error = -1; 316 return 0; 317 } 318 319 #define OCTALIFY(n, o) \ 320 /*LINTED*/ \ 321 (void)(*(n)++ = '\\', \ 322 *(n)++ = (((uint32_t)*(o) >> 6) & 3) + '0', \ 323 *(n)++ = (((uint32_t)*(o) >> 3) & 7) + '0', \ 324 *(n)++ = (((uint32_t)*(o) >> 0) & 7) + '0', \ 325 (o)++) 326 327 protected const char * 328 file_getbuffer(struct magic_set *ms) 329 { 330 char *pbuf, *op, *np; 331 size_t psize, len; 332 333 if (ms->event_flags & EVENT_HAD_ERR) 334 return NULL; 335 336 if (ms->flags & MAGIC_RAW) 337 return ms->o.buf; 338 339 if (ms->o.buf == NULL) 340 return NULL; 341 342 /* * 4 is for octal representation, + 1 is for NUL */ 343 len = strlen(ms->o.buf); 344 if (len > (SIZE_MAX - 1) / 4) { 345 file_oomem(ms, len); 346 return NULL; 347 } 348 psize = len * 4 + 1; 349 if ((pbuf = CAST(char *, realloc(ms->o.pbuf, psize))) == NULL) { 350 file_oomem(ms, psize); 351 return NULL; 352 } 353 ms->o.pbuf = pbuf; 354 355 #if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH) 356 { 357 mbstate_t state; 358 wchar_t nextchar; 359 int mb_conv = 1; 360 size_t bytesconsumed; 361 char *eop; 362 (void)memset(&state, 0, sizeof(mbstate_t)); 363 364 np = ms->o.pbuf; 365 op = ms->o.buf; 366 eop = op + len; 367 368 while (op < eop) { 369 bytesconsumed = mbrtowc(&nextchar, op, 370 (size_t)(eop - op), &state); 371 if (bytesconsumed == (size_t)(-1) || 372 bytesconsumed == (size_t)(-2)) { 373 mb_conv = 0; 374 break; 375 } 376 377 if (iswprint(nextchar)) { 378 (void)memcpy(np, op, bytesconsumed); 379 op += bytesconsumed; 380 np += bytesconsumed; 381 } else { 382 while (bytesconsumed-- > 0) 383 OCTALIFY(np, op); 384 } 385 } 386 *np = '\0'; 387 388 /* Parsing succeeded as a multi-byte sequence */ 389 if (mb_conv != 0) 390 return ms->o.pbuf; 391 } 392 #endif 393 394 for (np = ms->o.pbuf, op = ms->o.buf; *op; op++) { 395 if (isprint((unsigned char)*op)) { 396 *np++ = *op; 397 } else { 398 OCTALIFY(np, op); 399 } 400 } 401 *np = '\0'; 402 return ms->o.pbuf; 403 } 404 405 protected int 406 file_check_mem(struct magic_set *ms, unsigned int level) 407 { 408 size_t len; 409 410 if (level >= ms->c.len) { 411 len = (ms->c.len += 20) * sizeof(*ms->c.li); 412 ms->c.li = CAST(struct level_info *, (ms->c.li == NULL) ? 413 malloc(len) : 414 realloc(ms->c.li, len)); 415 if (ms->c.li == NULL) { 416 file_oomem(ms, len); 417 return -1; 418 } 419 } 420 ms->c.li[level].got_match = 0; 421 #ifdef ENABLE_CONDITIONALS 422 ms->c.li[level].last_match = 0; 423 ms->c.li[level].last_cond = COND_NONE; 424 #endif /* ENABLE_CONDITIONALS */ 425 return 0; 426 } 427