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 1.95 2018/05/24 18:09:17 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 fprintf(stderr, "vasprintf failed (%s)", strerror(errno));
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 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 char *rbuf = NULL;
187 struct buffer b;
188
189 buffer_init(&b, fd, buf, nb);
190 ms->mode = b.st.st_mode;
191
192 if (nb == 0) {
193 def = "empty";
194 type = "application/x-empty";
195 goto simple;
196 } else if (nb == 1) {
197 def = "very short file (no magic)";
198 goto simple;
199 }
200
201 if ((ms->flags & MAGIC_NO_CHECK_ENCODING) == 0) {
202 looks_text = file_encoding(ms, &b, NULL, 0,
203 &code, &code_mime, &ftype);
204 }
205
206 #ifdef __EMX__
207 if ((ms->flags & MAGIC_NO_CHECK_APPTYPE) == 0 && inname) {
208 m = file_os2_apptype(ms, inname, &b);
209 if ((ms->flags & MAGIC_DEBUG) != 0)
210 (void)fprintf(stderr, "[try os2_apptype %d]\n", m);
211 switch (m) {
212 case -1:
213 return -1;
214 case 0:
215 break;
216 default:
217 return 1;
218 }
219 }
220 #endif
221 #if HAVE_FORK
222 /* try compression stuff */
223 if ((ms->flags & MAGIC_NO_CHECK_COMPRESS) == 0) {
224 m = file_zmagic(ms, &b, inname);
225 if ((ms->flags & MAGIC_DEBUG) != 0)
226 (void)fprintf(stderr, "[try zmagic %d]\n", m);
227 if (m) {
228 goto done_encoding;
229 }
230 }
231 #endif
232 /* Check if we have a tar file */
233 if ((ms->flags & MAGIC_NO_CHECK_TAR) == 0) {
234 m = file_is_tar(ms, &b);
235 if ((ms->flags & MAGIC_DEBUG) != 0)
236 (void)fprintf(stderr, "[try tar %d]\n", m);
237 if (m) {
238 if (checkdone(ms, &rv))
239 goto done;
240 }
241 }
242
243 /* Check if we have a CDF file */
244 if ((ms->flags & MAGIC_NO_CHECK_CDF) == 0) {
245 m = file_trycdf(ms, &b);
246 if ((ms->flags & MAGIC_DEBUG) != 0)
247 (void)fprintf(stderr, "[try cdf %d]\n", m);
248 if (m) {
249 if (checkdone(ms, &rv))
250 goto done;
251 }
252 }
253 #ifdef BUILTIN_ELF
254 if ((ms->flags & MAGIC_NO_CHECK_ELF) == 0 && nb > 5 && fd != -1) {
255 file_pushbuf_t *pb;
256 /*
257 * We matched something in the file, so this
258 * *might* be an ELF file, and the file is at
259 * least 5 bytes long, so if it's an ELF file
260 * it has at least one byte past the ELF magic
261 * number - try extracting information from the
262 * ELF headers that cannot easily be extracted
263 * with rules in the magic file. We we don't
264 * print the information yet.
265 */
266 if ((pb = file_push_buffer(ms)) == NULL)
267 return -1;
268
269 rv = file_tryelf(ms, &b);
270 rbuf = file_pop_buffer(ms, pb);
271 if (rv != 1) {
272 free(rbuf);
273 rbuf = NULL;
274 }
275 if ((ms->flags & MAGIC_DEBUG) != 0)
276 (void)fprintf(stderr, "[try elf %d]\n", m);
277 }
278 #endif
279
280 /* try soft magic tests */
281 if ((ms->flags & MAGIC_NO_CHECK_SOFT) == 0) {
282 m = file_softmagic(ms, &b, NULL, NULL, BINTEST, looks_text);
283 if ((ms->flags & MAGIC_DEBUG) != 0)
284 (void)fprintf(stderr, "[try softmagic %d]\n", m);
285 if (m == 1 && rbuf) {
286 if (file_printf(ms, "%s", rbuf) == -1)
287 goto done;
288 }
289 if (m) {
290 if (checkdone(ms, &rv))
291 goto done;
292 }
293 }
294
295 /* try text properties */
296 if ((ms->flags & MAGIC_NO_CHECK_TEXT) == 0) {
297
298 m = file_ascmagic(ms, &b, looks_text);
299 if ((ms->flags & MAGIC_DEBUG) != 0)
300 (void)fprintf(stderr, "[try ascmagic %d]\n", m);
301 if (m) {
302 if (checkdone(ms, &rv))
303 goto done;
304 }
305 }
306
307 simple:
308 /* give up */
309 m = 1;
310 if (ms->flags & MAGIC_MIME) {
311 if ((ms->flags & MAGIC_MIME_TYPE) &&
312 file_printf(ms, "%s", type) == -1)
313 rv = -1;
314 } else if (ms->flags & MAGIC_APPLE) {
315 if (file_printf(ms, "UNKNUNKN") == -1)
316 rv = -1;
317 } else if (ms->flags & MAGIC_EXTENSION) {
318 if (file_printf(ms, "???") == -1)
319 rv = -1;
320 } else {
321 if (file_printf(ms, "%s", def) == -1)
322 rv = -1;
323 }
324 done:
325 if ((ms->flags & MAGIC_MIME_ENCODING) != 0) {
326 if (ms->flags & MAGIC_MIME_TYPE)
327 if (file_printf(ms, "; charset=") == -1)
328 rv = -1;
329 if (file_printf(ms, "%s", code_mime) == -1)
330 rv = -1;
331 }
332 #if HAVE_FORK
333 done_encoding:
334 #endif
335 free(rbuf);
336 buffer_fini(&b);
337 if (rv)
338 return rv;
339
340 return m;
341 }
342 #endif
343
344 protected int
file_reset(struct magic_set * ms,int checkloaded)345 file_reset(struct magic_set *ms, int checkloaded)
346 {
347 if (checkloaded && ms->mlist[0] == NULL) {
348 file_error(ms, 0, "no magic files loaded");
349 return -1;
350 }
351 if (ms->o.buf) {
352 free(ms->o.buf);
353 ms->o.buf = NULL;
354 }
355 if (ms->o.pbuf) {
356 free(ms->o.pbuf);
357 ms->o.pbuf = NULL;
358 }
359 ms->event_flags &= ~EVENT_HAD_ERR;
360 ms->error = -1;
361 return 0;
362 }
363
364 #define OCTALIFY(n, o) \
365 /*LINTED*/ \
366 (void)(*(n)++ = '\\', \
367 *(n)++ = (((uint32_t)*(o) >> 6) & 3) + '0', \
368 *(n)++ = (((uint32_t)*(o) >> 3) & 7) + '0', \
369 *(n)++ = (((uint32_t)*(o) >> 0) & 7) + '0', \
370 (o)++)
371
372 protected const char *
file_getbuffer(struct magic_set * ms)373 file_getbuffer(struct magic_set *ms)
374 {
375 char *pbuf, *op, *np;
376 size_t psize, len;
377
378 if (ms->event_flags & EVENT_HAD_ERR)
379 return NULL;
380
381 if (ms->flags & MAGIC_RAW)
382 return ms->o.buf;
383
384 if (ms->o.buf == NULL)
385 return NULL;
386
387 /* * 4 is for octal representation, + 1 is for NUL */
388 len = strlen(ms->o.buf);
389 if (len > (SIZE_MAX - 1) / 4) {
390 file_oomem(ms, len);
391 return NULL;
392 }
393 psize = len * 4 + 1;
394 if ((pbuf = CAST(char *, realloc(ms->o.pbuf, psize))) == NULL) {
395 file_oomem(ms, psize);
396 return NULL;
397 }
398 ms->o.pbuf = pbuf;
399
400 #if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH)
401 {
402 mbstate_t state;
403 wchar_t nextchar;
404 int mb_conv = 1;
405 size_t bytesconsumed;
406 char *eop;
407 (void)memset(&state, 0, sizeof(mbstate_t));
408
409 np = ms->o.pbuf;
410 op = ms->o.buf;
411 eop = op + len;
412
413 while (op < eop) {
414 bytesconsumed = mbrtowc(&nextchar, op,
415 (size_t)(eop - op), &state);
416 if (bytesconsumed == (size_t)(-1) ||
417 bytesconsumed == (size_t)(-2)) {
418 mb_conv = 0;
419 break;
420 }
421
422 if (iswprint(nextchar)) {
423 (void)memcpy(np, op, bytesconsumed);
424 op += bytesconsumed;
425 np += bytesconsumed;
426 } else {
427 while (bytesconsumed-- > 0)
428 OCTALIFY(np, op);
429 }
430 }
431 *np = '\0';
432
433 /* Parsing succeeded as a multi-byte sequence */
434 if (mb_conv != 0)
435 return ms->o.pbuf;
436 }
437 #endif
438
439 for (np = ms->o.pbuf, op = ms->o.buf; *op;) {
440 if (isprint((unsigned char)*op)) {
441 *np++ = *op++;
442 } else {
443 OCTALIFY(np, op);
444 }
445 }
446 *np = '\0';
447 return ms->o.pbuf;
448 }
449
450 protected int
file_check_mem(struct magic_set * ms,unsigned int level)451 file_check_mem(struct magic_set *ms, unsigned int level)
452 {
453 size_t len;
454
455 if (level >= ms->c.len) {
456 len = (ms->c.len = 20 + level) * sizeof(*ms->c.li);
457 ms->c.li = CAST(struct level_info *, (ms->c.li == NULL) ?
458 malloc(len) :
459 realloc(ms->c.li, len));
460 if (ms->c.li == NULL) {
461 file_oomem(ms, len);
462 return -1;
463 }
464 }
465 ms->c.li[level].got_match = 0;
466 #ifdef ENABLE_CONDITIONALS
467 ms->c.li[level].last_match = 0;
468 ms->c.li[level].last_cond = COND_NONE;
469 #endif /* ENABLE_CONDITIONALS */
470 return 0;
471 }
472
473 protected size_t
file_printedlen(const struct magic_set * ms)474 file_printedlen(const struct magic_set *ms)
475 {
476 return ms->o.buf == NULL ? 0 : strlen(ms->o.buf);
477 }
478
479 protected int
file_replace(struct magic_set * ms,const char * pat,const char * rep)480 file_replace(struct magic_set *ms, const char *pat, const char *rep)
481 {
482 file_regex_t rx;
483 int rc, rv = -1;
484
485 rc = file_regcomp(&rx, pat, REG_EXTENDED);
486 if (rc) {
487 file_regerror(&rx, rc, ms);
488 } else {
489 regmatch_t rm;
490 int nm = 0;
491 while (file_regexec(&rx, ms->o.buf, 1, &rm, 0) == 0) {
492 ms->o.buf[rm.rm_so] = '\0';
493 if (file_printf(ms, "%s%s", rep,
494 rm.rm_eo != 0 ? ms->o.buf + rm.rm_eo : "") == -1)
495 goto out;
496 nm++;
497 }
498 rv = nm;
499 }
500 out:
501 file_regfree(&rx);
502 return rv;
503 }
504
505 protected int
file_regcomp(file_regex_t * rx,const char * pat,int flags)506 file_regcomp(file_regex_t *rx, const char *pat, int flags)
507 {
508 #ifdef USE_C_LOCALE
509 rx->c_lc_ctype = newlocale(LC_CTYPE_MASK, "C", 0);
510 assert(rx->c_lc_ctype != NULL);
511 rx->old_lc_ctype = uselocale(rx->c_lc_ctype);
512 assert(rx->old_lc_ctype != NULL);
513 #else
514 rx->old_lc_ctype = setlocale(LC_CTYPE, "C");
515 #endif
516 rx->pat = pat;
517
518 return rx->rc = regcomp(&rx->rx, pat, flags);
519 }
520
521 protected int
file_regexec(file_regex_t * rx,const char * str,size_t nmatch,regmatch_t * pmatch,int eflags)522 file_regexec(file_regex_t *rx, const char *str, size_t nmatch,
523 regmatch_t* pmatch, int eflags)
524 {
525 assert(rx->rc == 0);
526 /* XXX: force initialization because glibc does not always do this */
527 memset(pmatch, 0, nmatch * sizeof(*pmatch));
528 return regexec(&rx->rx, str, nmatch, pmatch, eflags);
529 }
530
531 protected void
file_regfree(file_regex_t * rx)532 file_regfree(file_regex_t *rx)
533 {
534 if (rx->rc == 0)
535 regfree(&rx->rx);
536 #ifdef USE_C_LOCALE
537 (void)uselocale(rx->old_lc_ctype);
538 freelocale(rx->c_lc_ctype);
539 #else
540 (void)setlocale(LC_CTYPE, rx->old_lc_ctype);
541 #endif
542 }
543
544 protected void
file_regerror(file_regex_t * rx,int rc,struct magic_set * ms)545 file_regerror(file_regex_t *rx, int rc, struct magic_set *ms)
546 {
547 char errmsg[512];
548
549 (void)regerror(rc, &rx->rx, errmsg, sizeof(errmsg));
550 file_magerror(ms, "regex error %d for `%s', (%s)", rc, rx->pat,
551 errmsg);
552 }
553
554 protected file_pushbuf_t *
file_push_buffer(struct magic_set * ms)555 file_push_buffer(struct magic_set *ms)
556 {
557 file_pushbuf_t *pb;
558
559 if (ms->event_flags & EVENT_HAD_ERR)
560 return NULL;
561
562 if ((pb = (CAST(file_pushbuf_t *, malloc(sizeof(*pb))))) == NULL)
563 return NULL;
564
565 pb->buf = ms->o.buf;
566 pb->offset = ms->offset;
567
568 ms->o.buf = NULL;
569 ms->offset = 0;
570
571 return pb;
572 }
573
574 protected char *
file_pop_buffer(struct magic_set * ms,file_pushbuf_t * pb)575 file_pop_buffer(struct magic_set *ms, file_pushbuf_t *pb)
576 {
577 char *rbuf;
578
579 if (ms->event_flags & EVENT_HAD_ERR) {
580 free(pb->buf);
581 free(pb);
582 return NULL;
583 }
584
585 rbuf = ms->o.buf;
586
587 ms->o.buf = pb->buf;
588 ms->offset = pb->offset;
589
590 free(pb);
591 return rbuf;
592 }
593
594 /*
595 * convert string to ascii printable format.
596 */
597 protected char *
file_printable(char * buf,size_t bufsiz,const char * str)598 file_printable(char *buf, size_t bufsiz, const char *str)
599 {
600 char *ptr, *eptr;
601 const unsigned char *s = (const unsigned char *)str;
602
603 for (ptr = buf, eptr = ptr + bufsiz - 1; ptr < eptr && *s; s++) {
604 if (isprint(*s)) {
605 *ptr++ = *s;
606 continue;
607 }
608 if (ptr >= eptr - 3)
609 break;
610 *ptr++ = '\\';
611 *ptr++ = ((CAST(unsigned int, *s) >> 6) & 7) + '0';
612 *ptr++ = ((CAST(unsigned int, *s) >> 3) & 7) + '0';
613 *ptr++ = ((CAST(unsigned int, *s) >> 0) & 7) + '0';
614 }
615 *ptr = '\0';
616 return buf;
617 }
618