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 1.84 2015/09/10 13:32:19 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
file_vprintf(struct magic_set * ms,const char * fmt,va_list ap)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
file_printf(struct magic_set * ms,const char * fmt,...)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
file_error_core(struct magic_set * ms,int error,const char * f,va_list va,size_t lineno)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
file_error(struct magic_set * ms,int error,const char * f,...)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
file_magerror(struct magic_set * ms,const char * f,...)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
file_oomem(struct magic_set * ms,size_t len)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
file_badseek(struct magic_set * ms)152 file_badseek(struct magic_set *ms)
153 {
154 file_error(ms, errno, "error seeking");
155 }
156
157 protected void
file_badread(struct magic_set * ms)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
checkdone(struct magic_set * ms,int * rv)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
file_buffer(struct magic_set * ms,int fd,const char * inname,const void * buf,size_t nb)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 m = file_os2_apptype(ms, inname, buf, nb);
208 if ((ms->flags & MAGIC_DEBUG) != 0)
209 (void)fprintf(stderr, "[try os2_apptype %d]\n", m);
210 switch (m) {
211 case -1:
212 return -1;
213 case 0:
214 break;
215 default:
216 return 1;
217 }
218 }
219 #endif
220 #if HAVE_FORK
221 /* try compression stuff */
222 if ((ms->flags & MAGIC_NO_CHECK_COMPRESS) == 0) {
223 m = file_zmagic(ms, fd, inname, ubuf, nb);
224 if ((ms->flags & MAGIC_DEBUG) != 0)
225 (void)fprintf(stderr, "[try zmagic %d]\n", m);
226 if (m) {
227 goto done_encoding;
228 }
229 }
230 #endif
231 /* Check if we have a tar file */
232 if ((ms->flags & MAGIC_NO_CHECK_TAR) == 0) {
233 m = file_is_tar(ms, ubuf, nb);
234 if ((ms->flags & MAGIC_DEBUG) != 0)
235 (void)fprintf(stderr, "[try tar %d]\n", m);
236 if (m) {
237 if (checkdone(ms, &rv))
238 goto done;
239 }
240 }
241
242 /* Check if we have a CDF file */
243 if ((ms->flags & MAGIC_NO_CHECK_CDF) == 0) {
244 m = file_trycdf(ms, fd, ubuf, nb);
245 if ((ms->flags & MAGIC_DEBUG) != 0)
246 (void)fprintf(stderr, "[try cdf %d]\n", m);
247 if (m) {
248 if (checkdone(ms, &rv))
249 goto done;
250 }
251 }
252
253 /* try soft magic tests */
254 if ((ms->flags & MAGIC_NO_CHECK_SOFT) == 0)
255 m = file_softmagic(ms, ubuf, nb, 0, NULL, BINTEST, looks_text);
256 if ((ms->flags & MAGIC_DEBUG) != 0)
257 (void)fprintf(stderr, "[try softmagic %d]\n", m);
258 if (m) {
259 #ifdef BUILTIN_ELF
260 if ((ms->flags & MAGIC_NO_CHECK_ELF) == 0 && m == 1 &&
261 nb > 5 && fd != -1) {
262 /*
263 * We matched something in the file, so this
264 * *might* be an ELF file, and the file is at
265 * least 5 bytes long, so if it's an ELF file
266 * it has at least one byte past the ELF magic
267 * number - try extracting information from the
268 * ELF headers that cannot easily * be
269 * extracted with rules in the magic file.
270 */
271 m = file_tryelf(ms, fd, ubuf, nb);
272 if ((ms->flags & MAGIC_DEBUG) != 0)
273 (void)fprintf(stderr, "[try elf %d]\n",
274 m);
275 }
276 #endif
277 if (checkdone(ms, &rv))
278 goto done;
279 }
280
281 /* try text properties */
282 if ((ms->flags & MAGIC_NO_CHECK_TEXT) == 0) {
283
284 m = file_ascmagic(ms, ubuf, nb, 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 ((!mime || (mime & MAGIC_MIME_TYPE)) &&
297 file_printf(ms, "%s", mime ? type : def) == -1) {
298 rv = -1;
299 }
300 done:
301 if ((ms->flags & MAGIC_MIME_ENCODING) != 0) {
302 if (ms->flags & MAGIC_MIME_TYPE)
303 if (file_printf(ms, "; charset=") == -1)
304 rv = -1;
305 if (file_printf(ms, "%s", code_mime) == -1)
306 rv = -1;
307 }
308 #if HAVE_FORK
309 done_encoding:
310 #endif
311 free(u8buf);
312 if (rv)
313 return rv;
314
315 return m;
316 }
317 #endif
318
319 protected int
file_reset(struct magic_set * ms)320 file_reset(struct magic_set *ms)
321 {
322 if (ms->mlist[0] == NULL) {
323 file_error(ms, 0, "no magic files loaded");
324 return -1;
325 }
326 if (ms->o.buf) {
327 free(ms->o.buf);
328 ms->o.buf = NULL;
329 }
330 if (ms->o.pbuf) {
331 free(ms->o.pbuf);
332 ms->o.pbuf = NULL;
333 }
334 ms->event_flags &= ~EVENT_HAD_ERR;
335 ms->error = -1;
336 return 0;
337 }
338
339 #define OCTALIFY(n, o) \
340 /*LINTED*/ \
341 (void)(*(n)++ = '\\', \
342 *(n)++ = (((uint32_t)*(o) >> 6) & 3) + '0', \
343 *(n)++ = (((uint32_t)*(o) >> 3) & 7) + '0', \
344 *(n)++ = (((uint32_t)*(o) >> 0) & 7) + '0', \
345 (o)++)
346
347 protected const char *
file_getbuffer(struct magic_set * ms)348 file_getbuffer(struct magic_set *ms)
349 {
350 char *pbuf, *op, *np;
351 size_t psize, len;
352
353 if (ms->event_flags & EVENT_HAD_ERR)
354 return NULL;
355
356 if (ms->flags & MAGIC_RAW)
357 return ms->o.buf;
358
359 if (ms->o.buf == NULL)
360 return NULL;
361
362 /* * 4 is for octal representation, + 1 is for NUL */
363 len = strlen(ms->o.buf);
364 if (len > (SIZE_MAX - 1) / 4) {
365 file_oomem(ms, len);
366 return NULL;
367 }
368 psize = len * 4 + 1;
369 if ((pbuf = CAST(char *, realloc(ms->o.pbuf, psize))) == NULL) {
370 file_oomem(ms, psize);
371 return NULL;
372 }
373 ms->o.pbuf = pbuf;
374
375 #if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH)
376 {
377 mbstate_t state;
378 wchar_t nextchar;
379 int mb_conv = 1;
380 size_t bytesconsumed;
381 char *eop;
382 (void)memset(&state, 0, sizeof(mbstate_t));
383
384 np = ms->o.pbuf;
385 op = ms->o.buf;
386 eop = op + len;
387
388 while (op < eop) {
389 bytesconsumed = mbrtowc(&nextchar, op,
390 (size_t)(eop - op), &state);
391 if (bytesconsumed == (size_t)(-1) ||
392 bytesconsumed == (size_t)(-2)) {
393 mb_conv = 0;
394 break;
395 }
396
397 if (iswprint(nextchar)) {
398 (void)memcpy(np, op, bytesconsumed);
399 op += bytesconsumed;
400 np += bytesconsumed;
401 } else {
402 while (bytesconsumed-- > 0)
403 OCTALIFY(np, op);
404 }
405 }
406 *np = '\0';
407
408 /* Parsing succeeded as a multi-byte sequence */
409 if (mb_conv != 0)
410 return ms->o.pbuf;
411 }
412 #endif
413
414 for (np = ms->o.pbuf, op = ms->o.buf; *op;) {
415 if (isprint((unsigned char)*op)) {
416 *np++ = *op++;
417 } else {
418 OCTALIFY(np, op);
419 }
420 }
421 *np = '\0';
422 return ms->o.pbuf;
423 }
424
425 protected int
file_check_mem(struct magic_set * ms,unsigned int level)426 file_check_mem(struct magic_set *ms, unsigned int level)
427 {
428 size_t len;
429
430 if (level >= ms->c.len) {
431 len = (ms->c.len = 20 + level) * sizeof(*ms->c.li);
432 ms->c.li = CAST(struct level_info *, (ms->c.li == NULL) ?
433 malloc(len) :
434 realloc(ms->c.li, len));
435 if (ms->c.li == NULL) {
436 file_oomem(ms, len);
437 return -1;
438 }
439 }
440 ms->c.li[level].got_match = 0;
441 #ifdef ENABLE_CONDITIONALS
442 ms->c.li[level].last_match = 0;
443 ms->c.li[level].last_cond = COND_NONE;
444 #endif /* ENABLE_CONDITIONALS */
445 return 0;
446 }
447
448 protected size_t
file_printedlen(const struct magic_set * ms)449 file_printedlen(const struct magic_set *ms)
450 {
451 return ms->o.buf == NULL ? 0 : strlen(ms->o.buf);
452 }
453
454 protected int
file_replace(struct magic_set * ms,const char * pat,const char * rep)455 file_replace(struct magic_set *ms, const char *pat, const char *rep)
456 {
457 file_regex_t rx;
458 int rc, rv = -1;
459
460 rc = file_regcomp(&rx, pat, REG_EXTENDED);
461 if (rc) {
462 file_regerror(&rx, rc, ms);
463 } else {
464 regmatch_t rm;
465 int nm = 0;
466 while (file_regexec(&rx, ms->o.buf, 1, &rm, 0) == 0) {
467 ms->o.buf[rm.rm_so] = '\0';
468 if (file_printf(ms, "%s%s", rep,
469 rm.rm_eo != 0 ? ms->o.buf + rm.rm_eo : "") == -1)
470 goto out;
471 nm++;
472 }
473 rv = nm;
474 }
475 out:
476 file_regfree(&rx);
477 return rv;
478 }
479
480 protected int
file_regcomp(file_regex_t * rx,const char * pat,int flags)481 file_regcomp(file_regex_t *rx, const char *pat, int flags)
482 {
483 #ifdef USE_C_LOCALE
484 rx->c_lc_ctype = newlocale(LC_CTYPE_MASK, "C", 0);
485 assert(rx->c_lc_ctype != NULL);
486 rx->old_lc_ctype = uselocale(rx->c_lc_ctype);
487 assert(rx->old_lc_ctype != NULL);
488 #endif
489 rx->pat = pat;
490
491 return rx->rc = regcomp(&rx->rx, pat, flags);
492 }
493
494 protected int
file_regexec(file_regex_t * rx,const char * str,size_t nmatch,regmatch_t * pmatch,int eflags)495 file_regexec(file_regex_t *rx, const char *str, size_t nmatch,
496 regmatch_t* pmatch, int eflags)
497 {
498 assert(rx->rc == 0);
499 return regexec(&rx->rx, str, nmatch, pmatch, eflags);
500 }
501
502 protected void
file_regfree(file_regex_t * rx)503 file_regfree(file_regex_t *rx)
504 {
505 if (rx->rc == 0)
506 regfree(&rx->rx);
507 #ifdef USE_C_LOCALE
508 (void)uselocale(rx->old_lc_ctype);
509 freelocale(rx->c_lc_ctype);
510 #endif
511 }
512
513 protected void
file_regerror(file_regex_t * rx,int rc,struct magic_set * ms)514 file_regerror(file_regex_t *rx, int rc, struct magic_set *ms)
515 {
516 char errmsg[512];
517
518 (void)regerror(rc, &rx->rx, errmsg, sizeof(errmsg));
519 file_magerror(ms, "regex error %d for `%s', (%s)", rc, rx->pat,
520 errmsg);
521 }
522
523 protected file_pushbuf_t *
file_push_buffer(struct magic_set * ms)524 file_push_buffer(struct magic_set *ms)
525 {
526 file_pushbuf_t *pb;
527
528 if (ms->event_flags & EVENT_HAD_ERR)
529 return NULL;
530
531 if ((pb = (CAST(file_pushbuf_t *, malloc(sizeof(*pb))))) == NULL)
532 return NULL;
533
534 pb->buf = ms->o.buf;
535 pb->offset = ms->offset;
536
537 ms->o.buf = NULL;
538 ms->offset = 0;
539
540 return pb;
541 }
542
543 protected char *
file_pop_buffer(struct magic_set * ms,file_pushbuf_t * pb)544 file_pop_buffer(struct magic_set *ms, file_pushbuf_t *pb)
545 {
546 char *rbuf;
547
548 if (ms->event_flags & EVENT_HAD_ERR) {
549 free(pb->buf);
550 free(pb);
551 return NULL;
552 }
553
554 rbuf = ms->o.buf;
555
556 ms->o.buf = pb->buf;
557 ms->offset = pb->offset;
558
559 free(pb);
560 return rbuf;
561 }
562
563 /*
564 * convert string to ascii printable format.
565 */
566 protected char *
file_printable(char * buf,size_t bufsiz,const char * str)567 file_printable(char *buf, size_t bufsiz, const char *str)
568 {
569 char *ptr, *eptr;
570 const unsigned char *s = (const unsigned char *)str;
571
572 for (ptr = buf, eptr = ptr + bufsiz - 1; ptr < eptr && *s; s++) {
573 if (isprint(*s)) {
574 *ptr++ = *s;
575 continue;
576 }
577 if (ptr >= eptr - 3)
578 break;
579 *ptr++ = '\\';
580 *ptr++ = ((CAST(unsigned int, *s) >> 6) & 7) + '0';
581 *ptr++ = ((CAST(unsigned int, *s) >> 3) & 7) + '0';
582 *ptr++ = ((CAST(unsigned int, *s) >> 0) & 7) + '0';
583 }
584 *ptr = '\0';
585 return buf;
586 }
587