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 1.93 2017/08/28 13:39:18 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 unsigned char *ubuf = CAST(const unsigned char *, buf);
182 unichar *u8buf = NULL;
183 size_t ulen;
184 const char *code = NULL;
185 const char *code_mime = "binary";
186 const char *type = "application/octet-stream";
187 const char *def = "data";
188 const char *ftype = NULL;
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, ubuf, nb, &u8buf, &ulen,
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, buf, nb);
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, fd, inname, ubuf, nb);
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, ubuf, nb);
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, fd, ubuf, nb);
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, ubuf, nb, NULL, NULL, BINTEST,
255 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
282 /* try text properties */
283 if ((ms->flags & MAGIC_NO_CHECK_TEXT) == 0) {
284
285 m = file_ascmagic(ms, ubuf, nb, looks_text);
286 if ((ms->flags & MAGIC_DEBUG) != 0)
287 (void)fprintf(stderr, "[try ascmagic %d]\n", m);
288 if (m) {
289 if (checkdone(ms, &rv))
290 goto done;
291 }
292 }
293
294 simple:
295 /* give up */
296 m = 1;
297 if (ms->flags & MAGIC_MIME) {
298 if ((ms->flags & MAGIC_MIME_TYPE) &&
299 file_printf(ms, "%s", type) == -1)
300 rv = -1;
301 } else if (ms->flags & MAGIC_APPLE) {
302 if (file_printf(ms, "UNKNUNKN") == -1)
303 rv = -1;
304 } else if (ms->flags & MAGIC_EXTENSION) {
305 if (file_printf(ms, "???") == -1)
306 rv = -1;
307 } else {
308 if (file_printf(ms, "%s", def) == -1)
309 rv = -1;
310 }
311 done:
312 if ((ms->flags & MAGIC_MIME_ENCODING) != 0) {
313 if (ms->flags & MAGIC_MIME_TYPE)
314 if (file_printf(ms, "; charset=") == -1)
315 rv = -1;
316 if (file_printf(ms, "%s", code_mime) == -1)
317 rv = -1;
318 }
319 #if HAVE_FORK
320 done_encoding:
321 #endif
322 free(u8buf);
323 if (rv)
324 return rv;
325
326 return m;
327 }
328 #endif
329
330 protected int
file_reset(struct magic_set * ms,int checkloaded)331 file_reset(struct magic_set *ms, int checkloaded)
332 {
333 if (checkloaded && ms->mlist[0] == NULL) {
334 file_error(ms, 0, "no magic files loaded");
335 return -1;
336 }
337 if (ms->o.buf) {
338 free(ms->o.buf);
339 ms->o.buf = NULL;
340 }
341 if (ms->o.pbuf) {
342 free(ms->o.pbuf);
343 ms->o.pbuf = NULL;
344 }
345 ms->event_flags &= ~EVENT_HAD_ERR;
346 ms->error = -1;
347 return 0;
348 }
349
350 #define OCTALIFY(n, o) \
351 /*LINTED*/ \
352 (void)(*(n)++ = '\\', \
353 *(n)++ = (((uint32_t)*(o) >> 6) & 3) + '0', \
354 *(n)++ = (((uint32_t)*(o) >> 3) & 7) + '0', \
355 *(n)++ = (((uint32_t)*(o) >> 0) & 7) + '0', \
356 (o)++)
357
358 protected const char *
file_getbuffer(struct magic_set * ms)359 file_getbuffer(struct magic_set *ms)
360 {
361 char *pbuf, *op, *np;
362 size_t psize, len;
363
364 if (ms->event_flags & EVENT_HAD_ERR)
365 return NULL;
366
367 if (ms->flags & MAGIC_RAW)
368 return ms->o.buf;
369
370 if (ms->o.buf == NULL)
371 return NULL;
372
373 /* * 4 is for octal representation, + 1 is for NUL */
374 len = strlen(ms->o.buf);
375 if (len > (SIZE_MAX - 1) / 4) {
376 file_oomem(ms, len);
377 return NULL;
378 }
379 psize = len * 4 + 1;
380 if ((pbuf = CAST(char *, realloc(ms->o.pbuf, psize))) == NULL) {
381 file_oomem(ms, psize);
382 return NULL;
383 }
384 ms->o.pbuf = pbuf;
385
386 #if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH)
387 {
388 mbstate_t state;
389 wchar_t nextchar;
390 int mb_conv = 1;
391 size_t bytesconsumed;
392 char *eop;
393 (void)memset(&state, 0, sizeof(mbstate_t));
394
395 np = ms->o.pbuf;
396 op = ms->o.buf;
397 eop = op + len;
398
399 while (op < eop) {
400 bytesconsumed = mbrtowc(&nextchar, op,
401 (size_t)(eop - op), &state);
402 if (bytesconsumed == (size_t)(-1) ||
403 bytesconsumed == (size_t)(-2)) {
404 mb_conv = 0;
405 break;
406 }
407
408 if (iswprint(nextchar)) {
409 (void)memcpy(np, op, bytesconsumed);
410 op += bytesconsumed;
411 np += bytesconsumed;
412 } else {
413 while (bytesconsumed-- > 0)
414 OCTALIFY(np, op);
415 }
416 }
417 *np = '\0';
418
419 /* Parsing succeeded as a multi-byte sequence */
420 if (mb_conv != 0)
421 return ms->o.pbuf;
422 }
423 #endif
424
425 for (np = ms->o.pbuf, op = ms->o.buf; *op;) {
426 if (isprint((unsigned char)*op)) {
427 *np++ = *op++;
428 } else {
429 OCTALIFY(np, op);
430 }
431 }
432 *np = '\0';
433 return ms->o.pbuf;
434 }
435
436 protected int
file_check_mem(struct magic_set * ms,unsigned int level)437 file_check_mem(struct magic_set *ms, unsigned int level)
438 {
439 size_t len;
440
441 if (level >= ms->c.len) {
442 len = (ms->c.len = 20 + level) * sizeof(*ms->c.li);
443 ms->c.li = CAST(struct level_info *, (ms->c.li == NULL) ?
444 malloc(len) :
445 realloc(ms->c.li, len));
446 if (ms->c.li == NULL) {
447 file_oomem(ms, len);
448 return -1;
449 }
450 }
451 ms->c.li[level].got_match = 0;
452 #ifdef ENABLE_CONDITIONALS
453 ms->c.li[level].last_match = 0;
454 ms->c.li[level].last_cond = COND_NONE;
455 #endif /* ENABLE_CONDITIONALS */
456 return 0;
457 }
458
459 protected size_t
file_printedlen(const struct magic_set * ms)460 file_printedlen(const struct magic_set *ms)
461 {
462 return ms->o.buf == NULL ? 0 : strlen(ms->o.buf);
463 }
464
465 protected int
file_replace(struct magic_set * ms,const char * pat,const char * rep)466 file_replace(struct magic_set *ms, const char *pat, const char *rep)
467 {
468 file_regex_t rx;
469 int rc, rv = -1;
470
471 rc = file_regcomp(&rx, pat, REG_EXTENDED);
472 if (rc) {
473 file_regerror(&rx, rc, ms);
474 } else {
475 regmatch_t rm;
476 int nm = 0;
477 while (file_regexec(&rx, ms->o.buf, 1, &rm, 0) == 0) {
478 ms->o.buf[rm.rm_so] = '\0';
479 if (file_printf(ms, "%s%s", rep,
480 rm.rm_eo != 0 ? ms->o.buf + rm.rm_eo : "") == -1)
481 goto out;
482 nm++;
483 }
484 rv = nm;
485 }
486 out:
487 file_regfree(&rx);
488 return rv;
489 }
490
491 protected int
file_regcomp(file_regex_t * rx,const char * pat,int flags)492 file_regcomp(file_regex_t *rx, const char *pat, int flags)
493 {
494 #ifdef USE_C_LOCALE
495 rx->c_lc_ctype = newlocale(LC_CTYPE_MASK, "C", 0);
496 assert(rx->c_lc_ctype != NULL);
497 rx->old_lc_ctype = uselocale(rx->c_lc_ctype);
498 assert(rx->old_lc_ctype != NULL);
499 #else
500 rx->old_lc_ctype = setlocale(LC_CTYPE, "C");
501 #endif
502 rx->pat = pat;
503
504 return rx->rc = regcomp(&rx->rx, pat, flags);
505 }
506
507 protected int
file_regexec(file_regex_t * rx,const char * str,size_t nmatch,regmatch_t * pmatch,int eflags)508 file_regexec(file_regex_t *rx, const char *str, size_t nmatch,
509 regmatch_t* pmatch, int eflags)
510 {
511 assert(rx->rc == 0);
512 /* XXX: force initialization because glibc does not always do this */
513 memset(pmatch, 0, nmatch * sizeof(*pmatch));
514 return regexec(&rx->rx, str, nmatch, pmatch, eflags);
515 }
516
517 protected void
file_regfree(file_regex_t * rx)518 file_regfree(file_regex_t *rx)
519 {
520 if (rx->rc == 0)
521 regfree(&rx->rx);
522 #ifdef USE_C_LOCALE
523 (void)uselocale(rx->old_lc_ctype);
524 freelocale(rx->c_lc_ctype);
525 #else
526 (void)setlocale(LC_CTYPE, rx->old_lc_ctype);
527 #endif
528 }
529
530 protected void
file_regerror(file_regex_t * rx,int rc,struct magic_set * ms)531 file_regerror(file_regex_t *rx, int rc, struct magic_set *ms)
532 {
533 char errmsg[512];
534
535 (void)regerror(rc, &rx->rx, errmsg, sizeof(errmsg));
536 file_magerror(ms, "regex error %d for `%s', (%s)", rc, rx->pat,
537 errmsg);
538 }
539
540 protected file_pushbuf_t *
file_push_buffer(struct magic_set * ms)541 file_push_buffer(struct magic_set *ms)
542 {
543 file_pushbuf_t *pb;
544
545 if (ms->event_flags & EVENT_HAD_ERR)
546 return NULL;
547
548 if ((pb = (CAST(file_pushbuf_t *, malloc(sizeof(*pb))))) == NULL)
549 return NULL;
550
551 pb->buf = ms->o.buf;
552 pb->offset = ms->offset;
553
554 ms->o.buf = NULL;
555 ms->offset = 0;
556
557 return pb;
558 }
559
560 protected char *
file_pop_buffer(struct magic_set * ms,file_pushbuf_t * pb)561 file_pop_buffer(struct magic_set *ms, file_pushbuf_t *pb)
562 {
563 char *rbuf;
564
565 if (ms->event_flags & EVENT_HAD_ERR) {
566 free(pb->buf);
567 free(pb);
568 return NULL;
569 }
570
571 rbuf = ms->o.buf;
572
573 ms->o.buf = pb->buf;
574 ms->offset = pb->offset;
575
576 free(pb);
577 return rbuf;
578 }
579
580 /*
581 * convert string to ascii printable format.
582 */
583 protected char *
file_printable(char * buf,size_t bufsiz,const char * str)584 file_printable(char *buf, size_t bufsiz, const char *str)
585 {
586 char *ptr, *eptr;
587 const unsigned char *s = (const unsigned char *)str;
588
589 for (ptr = buf, eptr = ptr + bufsiz - 1; ptr < eptr && *s; s++) {
590 if (isprint(*s)) {
591 *ptr++ = *s;
592 continue;
593 }
594 if (ptr >= eptr - 3)
595 break;
596 *ptr++ = '\\';
597 *ptr++ = ((CAST(unsigned int, *s) >> 6) & 7) + '0';
598 *ptr++ = ((CAST(unsigned int, *s) >> 3) & 7) + '0';
599 *ptr++ = ((CAST(unsigned int, *s) >> 0) & 7) + '0';
600 }
601 *ptr = '\0';
602 return buf;
603 }
604