xref: /netbsd-src/external/bsd/file/dist/src/funcs.c (revision afab4e300d3a9fb07dd8c80daf53d0feb3345706)
1 /*	$NetBSD: funcs.c,v 1.20 2022/09/24 20:21:46 christos Exp $	*/
2 
3 /*
4  * Copyright (c) Christos Zoulas 2003.
5  * All Rights Reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice immediately at the beginning of the file, without modification,
12  *    this list of conditions, and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
21  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 #include "file.h"
30 
31 #ifndef	lint
32 #if 0
33 FILE_RCSID("@(#)$File: funcs.c,v 1.132 2022/09/24 19:17:26 christos Exp $")
34 #else
35 __RCSID("$NetBSD: funcs.c,v 1.20 2022/09/24 20:21:46 christos Exp $");
36 #endif
37 #endif	/* lint */
38 
39 #include "magic.h"
40 #include <assert.h>
41 #include <stdarg.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <ctype.h>
45 #ifdef HAVE_UNISTD_H
46 #include <unistd.h>	/* for pipe2() */
47 #endif
48 #if defined(HAVE_WCHAR_H)
49 #include <wchar.h>
50 #endif
51 #if defined(HAVE_WCTYPE_H)
52 #include <wctype.h>
53 #endif
54 #include <limits.h>
55 
56 #ifndef SIZE_MAX
57 #define SIZE_MAX	((size_t)~0)
58 #endif
59 
60 protected char *
61 file_copystr(char *buf, size_t blen, size_t width, const char *str)
62 {
63 	if (blen == 0)
64 		return buf;
65 	if (width >= blen)
66 		width = blen - 1;
67 	memcpy(buf, str, width);
68 	buf[width] = '\0';
69 	return buf;
70 }
71 
72 private void
73 file_clearbuf(struct magic_set *ms)
74 {
75 	free(ms->o.buf);
76 	ms->o.buf = NULL;
77 	ms->o.blen = 0;
78 }
79 
80 private int
81 file_checkfield(char *msg, size_t mlen, const char *what, const char **pp)
82 {
83 	const char *p = *pp;
84 	int fw = 0;
85 
86 	while (*p && isdigit((unsigned char)*p))
87 		fw = fw * 10 + (*p++ - '0');
88 
89 	*pp = p;
90 
91 	if (fw < 1024)
92 		return 1;
93 	if (msg)
94 		snprintf(msg, mlen, "field %s too large: %d", what, fw);
95 
96 	return 0;
97 }
98 
99 protected int
100 file_checkfmt(char *msg, size_t mlen, const char *fmt)
101 {
102 	const char *p;
103 	for (p = fmt; *p; p++) {
104 		if (*p != '%')
105 			continue;
106 		if (*++p == '%')
107 			continue;
108 		// Skip uninteresting.
109 		while (strchr("#0.'+- ", *p) != NULL)
110 			p++;
111 		if (*p == '*') {
112 			if (msg)
113 				snprintf(msg, mlen, "* not allowed in format");
114 			return -1;
115 		}
116 
117 		if (!file_checkfield(msg, mlen, "width", &p))
118 			return -1;
119 
120 		if (*p == '.') {
121 			p++;
122 			if (!file_checkfield(msg, mlen, "precision", &p))
123 				return -1;
124 		}
125 
126 		if (!isalpha((unsigned char)*p)) {
127 			if (msg)
128 				snprintf(msg, mlen, "bad format char: %c", *p);
129 			return -1;
130 		}
131 	}
132 	return 0;
133 }
134 
135 /*
136  * Like printf, only we append to a buffer.
137  */
138 protected int
139 file_vprintf(struct magic_set *ms, const char *fmt, va_list ap)
140 {
141 	int len;
142 	char *buf, *newstr;
143 	char tbuf[1024];
144 
145 	if (ms->event_flags & EVENT_HAD_ERR)
146 		return 0;
147 
148 	if (file_checkfmt(tbuf, sizeof(tbuf), fmt)) {
149 		file_clearbuf(ms);
150 		file_error(ms, 0, "Bad magic format `%s' (%s)", fmt, tbuf);
151 		return -1;
152 	}
153 
154 	len = vasprintf(&buf, fmt, ap);
155 	if (len < 0 || (size_t)len > 1024 || len + ms->o.blen > 1024 * 1024) {
156 		size_t blen = ms->o.blen;
157 		free(buf);
158 		file_clearbuf(ms);
159 		file_error(ms, 0, "Output buffer space exceeded %d+%"
160 		    SIZE_T_FORMAT "u", len, blen);
161 		return -1;
162 	}
163 
164 	if (ms->o.buf != NULL) {
165 		len = asprintf(&newstr, "%s%s", ms->o.buf, buf);
166 		free(buf);
167 		if (len < 0)
168 			goto out;
169 		free(ms->o.buf);
170 		buf = newstr;
171 	}
172 	ms->o.buf = buf;
173 	ms->o.blen = len;
174 	return 0;
175 out:
176 	file_clearbuf(ms);
177 	file_error(ms, errno, "vasprintf failed");
178 	return -1;
179 }
180 
181 protected int
182 file_printf(struct magic_set *ms, const char *fmt, ...)
183 {
184 	int rv;
185 	va_list ap;
186 
187 	va_start(ap, fmt);
188 	rv = file_vprintf(ms, fmt, ap);
189 	va_end(ap);
190 	return rv;
191 }
192 
193 /*
194  * error - print best error message possible
195  */
196 /*VARARGS*/
197 __attribute__((__format__(__printf__, 3, 0)))
198 private void
199 file_error_core(struct magic_set *ms, int error, const char *f, va_list va,
200     size_t lineno)
201 {
202 	/* Only the first error is ok */
203 	if (ms->event_flags & EVENT_HAD_ERR)
204 		return;
205 	if (lineno != 0) {
206 		file_clearbuf(ms);
207 		(void)file_printf(ms, "line %" SIZE_T_FORMAT "u:", lineno);
208 	}
209 	if (ms->o.buf && *ms->o.buf)
210 		(void)file_printf(ms, " ");
211 	(void)file_vprintf(ms, f, va);
212 	if (error > 0)
213 		(void)file_printf(ms, " (%s)", strerror(error));
214 	ms->event_flags |= EVENT_HAD_ERR;
215 	ms->error = error;
216 }
217 
218 /*VARARGS*/
219 protected void
220 file_error(struct magic_set *ms, int error, const char *f, ...)
221 {
222 	va_list va;
223 	va_start(va, f);
224 	file_error_core(ms, error, f, va, 0);
225 	va_end(va);
226 }
227 
228 /*
229  * Print an error with magic line number.
230  */
231 /*VARARGS*/
232 protected void
233 file_magerror(struct magic_set *ms, const char *f, ...)
234 {
235 	va_list va;
236 	va_start(va, f);
237 	file_error_core(ms, 0, f, va, ms->line);
238 	va_end(va);
239 }
240 
241 protected void
242 file_oomem(struct magic_set *ms, size_t len)
243 {
244 	file_error(ms, errno, "cannot allocate %" SIZE_T_FORMAT "u bytes",
245 	    len);
246 }
247 
248 protected void
249 file_badseek(struct magic_set *ms)
250 {
251 	file_error(ms, errno, "error seeking");
252 }
253 
254 protected void
255 file_badread(struct magic_set *ms)
256 {
257 	file_error(ms, errno, "error reading");
258 }
259 
260 #ifndef COMPILE_ONLY
261 #define FILE_SEPARATOR "\n- "
262 
263 protected int
264 file_separator(struct magic_set *ms)
265 {
266 	return file_printf(ms, FILE_SEPARATOR);
267 }
268 
269 static void
270 trim_separator(struct magic_set *ms)
271 {
272 	size_t l;
273 
274 	if (ms->o.buf == NULL)
275 		return;
276 
277 	l = strlen(ms->o.buf);
278 	if (l < sizeof(FILE_SEPARATOR))
279 		return;
280 
281 	l -= sizeof(FILE_SEPARATOR) - 1;
282 	if (strcmp(ms->o.buf + l, FILE_SEPARATOR) != 0)
283 		return;
284 
285 	ms->o.buf[l] = '\0';
286 }
287 
288 static int
289 checkdone(struct magic_set *ms, int *rv)
290 {
291 	if ((ms->flags & MAGIC_CONTINUE) == 0)
292 		return 1;
293 	if (file_separator(ms) == -1)
294 		*rv = -1;
295 	return 0;
296 }
297 
298 protected int
299 file_default(struct magic_set *ms, size_t nb)
300 {
301 	if (ms->flags & MAGIC_MIME) {
302 		if ((ms->flags & MAGIC_MIME_TYPE) &&
303 		    file_printf(ms, "application/%s",
304 			nb ? "octet-stream" : "x-empty") == -1)
305 			return -1;
306 		return 1;
307 	}
308 	if (ms->flags & MAGIC_APPLE) {
309 		if (file_printf(ms, "UNKNUNKN") == -1)
310 			return -1;
311 		return 1;
312 	}
313 	if (ms->flags & MAGIC_EXTENSION) {
314 		if (file_printf(ms, "???") == -1)
315 			return -1;
316 		return 1;
317 	}
318 	return 0;
319 }
320 
321 /*
322  * The magic detection functions return:
323  *	 1: found
324  *	 0: not found
325  *	-1: error
326  */
327 /*ARGSUSED*/
328 protected int
329 file_buffer(struct magic_set *ms, int fd, struct stat *st,
330     const char *inname __attribute__ ((__unused__)),
331     const void *buf, size_t nb)
332 {
333 	int m = 0, rv = 0, looks_text = 0;
334 	const char *code = NULL;
335 	const char *code_mime = "binary";
336 	const char *def = "data";
337 	const char *ftype = NULL;
338 	char *rbuf = NULL;
339 	struct buffer b;
340 
341 	buffer_init(&b, fd, st, buf, nb);
342 	ms->mode = b.st.st_mode;
343 
344 	if (nb == 0) {
345 		def = "empty";
346 		goto simple;
347 	} else if (nb == 1) {
348 		def = "very short file (no magic)";
349 		goto simple;
350 	}
351 
352 	if ((ms->flags & MAGIC_NO_CHECK_ENCODING) == 0) {
353 		looks_text = file_encoding(ms, &b, NULL, 0,
354 		    &code, &code_mime, &ftype);
355 	}
356 
357 #ifdef __EMX__
358 	if ((ms->flags & MAGIC_NO_CHECK_APPTYPE) == 0 && inname) {
359 		m = file_os2_apptype(ms, inname, &b);
360 		if ((ms->flags & MAGIC_DEBUG) != 0)
361 			(void)fprintf(stderr, "[try os2_apptype %d]\n", m);
362 		switch (m) {
363 		case -1:
364 			return -1;
365 		case 0:
366 			break;
367 		default:
368 			return 1;
369 		}
370 	}
371 #endif
372 #if HAVE_FORK
373 	/* try compression stuff */
374 	if ((ms->flags & MAGIC_NO_CHECK_COMPRESS) == 0) {
375 		m = file_zmagic(ms, &b, inname);
376 		if ((ms->flags & MAGIC_DEBUG) != 0)
377 			(void)fprintf(stderr, "[try zmagic %d]\n", m);
378 		if (m) {
379 			goto done_encoding;
380 		}
381 	}
382 #endif
383 	/* Check if we have a tar file */
384 	if ((ms->flags & MAGIC_NO_CHECK_TAR) == 0) {
385 		m = file_is_tar(ms, &b);
386 		if ((ms->flags & MAGIC_DEBUG) != 0)
387 			(void)fprintf(stderr, "[try tar %d]\n", m);
388 		if (m) {
389 			if (checkdone(ms, &rv))
390 				goto done;
391 		}
392 	}
393 
394 	/* Check if we have a JSON file */
395 	if ((ms->flags & MAGIC_NO_CHECK_JSON) == 0) {
396 		m = file_is_json(ms, &b);
397 		if ((ms->flags & MAGIC_DEBUG) != 0)
398 			(void)fprintf(stderr, "[try json %d]\n", m);
399 		if (m) {
400 			if (checkdone(ms, &rv))
401 				goto done;
402 		}
403 	}
404 
405 	/* Check if we have a CSV file */
406 	if ((ms->flags & MAGIC_NO_CHECK_CSV) == 0) {
407 		m = file_is_csv(ms, &b, looks_text);
408 		if ((ms->flags & MAGIC_DEBUG) != 0)
409 			(void)fprintf(stderr, "[try csv %d]\n", m);
410 		if (m) {
411 			if (checkdone(ms, &rv))
412 				goto done;
413 		}
414 	}
415 
416 	/* Check if we have a CDF file */
417 	if ((ms->flags & MAGIC_NO_CHECK_CDF) == 0) {
418 		m = file_trycdf(ms, &b);
419 		if ((ms->flags & MAGIC_DEBUG) != 0)
420 			(void)fprintf(stderr, "[try cdf %d]\n", m);
421 		if (m) {
422 			if (checkdone(ms, &rv))
423 				goto done;
424 		}
425 	}
426 #ifdef BUILTIN_ELF
427 	if ((ms->flags & MAGIC_NO_CHECK_ELF) == 0 && nb > 5 && fd != -1) {
428 		file_pushbuf_t *pb;
429 		/*
430 		 * We matched something in the file, so this
431 		 * *might* be an ELF file, and the file is at
432 		 * least 5 bytes long, so if it's an ELF file
433 		 * it has at least one byte past the ELF magic
434 		 * number - try extracting information from the
435 		 * ELF headers that cannot easily be  extracted
436 		 * with rules in the magic file. We we don't
437 		 * print the information yet.
438 		 */
439 		if ((pb = file_push_buffer(ms)) == NULL)
440 			return -1;
441 
442 		rv = file_tryelf(ms, &b);
443 		rbuf = file_pop_buffer(ms, pb);
444 		if (rv == -1) {
445 			free(rbuf);
446 			rbuf = NULL;
447 		}
448 		if ((ms->flags & MAGIC_DEBUG) != 0)
449 			(void)fprintf(stderr, "[try elf %d]\n", m);
450 	}
451 #endif
452 
453 	/* try soft magic tests */
454 	if ((ms->flags & MAGIC_NO_CHECK_SOFT) == 0) {
455 		m = file_softmagic(ms, &b, NULL, NULL, BINTEST, looks_text);
456 		if ((ms->flags & MAGIC_DEBUG) != 0)
457 			(void)fprintf(stderr, "[try softmagic %d]\n", m);
458 		if (m == 1 && rbuf) {
459 			if (file_printf(ms, "%s", rbuf) == -1)
460 				goto done;
461 		}
462 		if (m) {
463 			if (checkdone(ms, &rv))
464 				goto done;
465 		}
466 	}
467 
468 	/* try text properties */
469 	if ((ms->flags & MAGIC_NO_CHECK_TEXT) == 0) {
470 
471 		m = file_ascmagic(ms, &b, looks_text);
472 		if ((ms->flags & MAGIC_DEBUG) != 0)
473 			(void)fprintf(stderr, "[try ascmagic %d]\n", m);
474 		if (m) {
475 			goto done;
476 		}
477 	}
478 
479 simple:
480 	/* give up */
481 	if (m == 0) {
482 		m = 1;
483 		rv = file_default(ms, nb);
484 		if (rv == 0)
485 			if (file_printf(ms, "%s", def) == -1)
486 				rv = -1;
487 	}
488  done:
489 	trim_separator(ms);
490 	if ((ms->flags & MAGIC_MIME_ENCODING) != 0) {
491 		if (ms->flags & MAGIC_MIME_TYPE)
492 			if (file_printf(ms, "; charset=") == -1)
493 				rv = -1;
494 		if (file_printf(ms, "%s", code_mime) == -1)
495 			rv = -1;
496 	}
497 #if HAVE_FORK
498  done_encoding:
499 #endif
500 	free(rbuf);
501 	buffer_fini(&b);
502 	if (rv)
503 		return rv;
504 
505 	return m;
506 }
507 #endif
508 
509 protected int
510 file_reset(struct magic_set *ms, int checkloaded)
511 {
512 	if (checkloaded && ms->mlist[0] == NULL) {
513 		file_error(ms, 0, "no magic files loaded");
514 		return -1;
515 	}
516 	file_clearbuf(ms);
517 	if (ms->o.pbuf) {
518 		free(ms->o.pbuf);
519 		ms->o.pbuf = NULL;
520 	}
521 	ms->event_flags &= ~EVENT_HAD_ERR;
522 	ms->error = -1;
523 	return 0;
524 }
525 
526 #define OCTALIFY(n, o)	\
527 	/*LINTED*/ \
528 	(void)(*(n)++ = '\\', \
529 	*(n)++ = ((CAST(uint32_t, *(o)) >> 6) & 3) + '0', \
530 	*(n)++ = ((CAST(uint32_t, *(o)) >> 3) & 7) + '0', \
531 	*(n)++ = ((CAST(uint32_t, *(o)) >> 0) & 7) + '0', \
532 	(o)++)
533 
534 protected const char *
535 file_getbuffer(struct magic_set *ms)
536 {
537 	char *pbuf, *op, *np;
538 	size_t psize, len;
539 
540 	if (ms->event_flags & EVENT_HAD_ERR)
541 		return NULL;
542 
543 	if (ms->flags & MAGIC_RAW)
544 		return ms->o.buf;
545 
546 	if (ms->o.buf == NULL)
547 		return NULL;
548 
549 	/* * 4 is for octal representation, + 1 is for NUL */
550 	len = strlen(ms->o.buf);
551 	if (len > (SIZE_MAX - 1) / 4) {
552 		file_oomem(ms, len);
553 		return NULL;
554 	}
555 	psize = len * 4 + 1;
556 	if ((pbuf = CAST(char *, realloc(ms->o.pbuf, psize))) == NULL) {
557 		file_oomem(ms, psize);
558 		return NULL;
559 	}
560 	ms->o.pbuf = pbuf;
561 
562 #if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH)
563 	{
564 		mbstate_t state;
565 		wchar_t nextchar;
566 		int mb_conv = 1;
567 		size_t bytesconsumed;
568 		char *eop;
569 		(void)memset(&state, 0, sizeof(mbstate_t));
570 
571 		np = ms->o.pbuf;
572 		op = ms->o.buf;
573 		eop = op + len;
574 
575 		while (op < eop) {
576 			bytesconsumed = mbrtowc(&nextchar, op,
577 			    CAST(size_t, eop - op), &state);
578 			if (bytesconsumed == CAST(size_t, -1) ||
579 			    bytesconsumed == CAST(size_t, -2)) {
580 				mb_conv = 0;
581 				break;
582 			}
583 
584 			if (iswprint(nextchar)) {
585 				(void)memcpy(np, op, bytesconsumed);
586 				op += bytesconsumed;
587 				np += bytesconsumed;
588 			} else {
589 				while (bytesconsumed-- > 0)
590 					OCTALIFY(np, op);
591 			}
592 		}
593 		*np = '\0';
594 
595 		/* Parsing succeeded as a multi-byte sequence */
596 		if (mb_conv != 0)
597 			return ms->o.pbuf;
598 	}
599 #endif
600 
601 	for (np = ms->o.pbuf, op = ms->o.buf; *op;) {
602 		if (isprint(CAST(unsigned char, *op))) {
603 			*np++ = *op++;
604 		} else {
605 			OCTALIFY(np, op);
606 		}
607 	}
608 	*np = '\0';
609 	return ms->o.pbuf;
610 }
611 
612 protected int
613 file_check_mem(struct magic_set *ms, unsigned int level)
614 {
615 	size_t len;
616 
617 	if (level >= ms->c.len) {
618 		len = (ms->c.len = 20 + level) * sizeof(*ms->c.li);
619 		ms->c.li = CAST(struct level_info *, (ms->c.li == NULL) ?
620 		    malloc(len) :
621 		    realloc(ms->c.li, len));
622 		if (ms->c.li == NULL) {
623 			file_oomem(ms, len);
624 			return -1;
625 		}
626 	}
627 	ms->c.li[level].got_match = 0;
628 #ifdef ENABLE_CONDITIONALS
629 	ms->c.li[level].last_match = 0;
630 	ms->c.li[level].last_cond = COND_NONE;
631 #endif /* ENABLE_CONDITIONALS */
632 	return 0;
633 }
634 
635 protected size_t
636 file_printedlen(const struct magic_set *ms)
637 {
638 	return ms->o.blen;
639 }
640 
641 protected int
642 file_replace(struct magic_set *ms, const char *pat, const char *rep)
643 {
644 	file_regex_t rx;
645 	int rc, rv = -1;
646 
647 	rc = file_regcomp(ms, &rx, pat, REG_EXTENDED);
648 	if (rc == 0) {
649 		regmatch_t rm;
650 		int nm = 0;
651 		while (file_regexec(ms, &rx, ms->o.buf, 1, &rm, 0) == 0) {
652 			ms->o.buf[rm.rm_so] = '\0';
653 			if (file_printf(ms, "%s%s", rep,
654 			    rm.rm_eo != 0 ? ms->o.buf + rm.rm_eo : "") == -1)
655 				goto out;
656 			nm++;
657 		}
658 		rv = nm;
659 	}
660 out:
661 	file_regfree(&rx);
662 	return rv;
663 }
664 
665 private int
666 check_regex(struct magic_set *ms, const char *pat)
667 {
668 	char sbuf[512];
669 	unsigned char oc = '\0';
670 
671 	for (const char *p = pat; *p; p++) {
672 		unsigned char c = *p;
673 		// Avoid repetition
674 		if (c == oc && strchr("?*+{", c) != NULL) {
675 			size_t len = strlen(pat);
676 			file_magwarn(ms,
677 			    "repetition-operator operand `%c' "
678 			    "invalid in regex `%s'", c,
679 			    file_printable(ms, sbuf, sizeof(sbuf), pat, len));
680 			return -1;
681 		}
682 		oc = c;
683 		if (isprint(c) || isspace(c) || c == '\b'
684 		    || c == 0x8a) // XXX: apple magic fixme
685 			continue;
686 		size_t len = strlen(pat);
687 		file_magwarn(ms,
688 		    "non-ascii characters in regex \\%#o `%s'",
689 		    c, file_printable(ms, sbuf, sizeof(sbuf), pat, len));
690 		return -1;
691 	}
692 	return 0;
693 }
694 
695 protected int
696 file_regcomp(struct magic_set *ms file_locale_used, file_regex_t *rx,
697     const char *pat, int flags)
698 {
699 	if (check_regex(ms, pat) == -1)
700 		return -1;
701 
702 #ifdef USE_C_LOCALE
703 	locale_t old = uselocale(ms->c_lc_ctype);
704 	assert(old != NULL);
705 #else
706 	char old[1024];
707 	strlcpy(old, setlocale(LC_CTYPE, NULL), sizeof(old));
708 	(void)setlocale(LC_CTYPE, "C");
709 #endif
710 	int rc;
711 	rc = regcomp(rx, pat, flags);
712 
713 #ifdef USE_C_LOCALE
714 	uselocale(old);
715 #else
716 	(void)setlocale(LC_CTYPE, old);
717 #endif
718 	if (rc > 0 && (ms->flags & MAGIC_CHECK)) {
719 		char errmsg[512], buf[512];
720 
721 		(void)regerror(rc, rx, errmsg, sizeof(errmsg));
722 		file_magerror(ms, "regex error %d for `%s', (%s)", rc,
723 		    file_printable(ms, buf, sizeof(buf), pat, strlen(pat)),
724 		    errmsg);
725 	}
726 	return rc;
727 }
728 
729 /*ARGSUSED*/
730 protected int
731 file_regexec(struct magic_set *ms file_locale_used, file_regex_t *rx,
732     const char *str, size_t nmatch, regmatch_t* pmatch, int eflags)
733 {
734 #ifdef USE_C_LOCALE
735 	locale_t old = uselocale(ms->c_lc_ctype);
736 	assert(old != NULL);
737 #else
738 	char old[1024];
739 	strlcpy(old, setlocale(LC_CTYPE, NULL), sizeof(old));
740 	(void)setlocale(LC_CTYPE, "C");
741 #endif
742 	int rc;
743 	/* XXX: force initialization because glibc does not always do this */
744 	if (nmatch != 0)
745 		memset(pmatch, 0, nmatch * sizeof(*pmatch));
746 	rc = regexec(rx, str, nmatch, pmatch, eflags);
747 #ifdef USE_C_LOCALE
748 	uselocale(old);
749 #else
750 	(void)setlocale(LC_CTYPE, old);
751 #endif
752 	return rc;
753 }
754 
755 protected void
756 file_regfree(file_regex_t *rx)
757 {
758 	regfree(rx);
759 }
760 
761 protected file_pushbuf_t *
762 file_push_buffer(struct magic_set *ms)
763 {
764 	file_pushbuf_t *pb;
765 
766 	if (ms->event_flags & EVENT_HAD_ERR)
767 		return NULL;
768 
769 	if ((pb = (CAST(file_pushbuf_t *, malloc(sizeof(*pb))))) == NULL)
770 		return NULL;
771 
772 	pb->buf = ms->o.buf;
773 	pb->blen = ms->o.blen;
774 	pb->offset = ms->offset;
775 
776 	ms->o.buf = NULL;
777 	ms->o.blen = 0;
778 	ms->offset = 0;
779 
780 	return pb;
781 }
782 
783 protected char *
784 file_pop_buffer(struct magic_set *ms, file_pushbuf_t *pb)
785 {
786 	char *rbuf;
787 
788 	if (ms->event_flags & EVENT_HAD_ERR) {
789 		free(pb->buf);
790 		free(pb);
791 		return NULL;
792 	}
793 
794 	rbuf = ms->o.buf;
795 
796 	ms->o.buf = pb->buf;
797 	ms->o.blen = pb->blen;
798 	ms->offset = pb->offset;
799 
800 	free(pb);
801 	return rbuf;
802 }
803 
804 /*
805  * convert string to ascii printable format.
806  */
807 protected char *
808 file_printable(struct magic_set *ms, char *buf, size_t bufsiz,
809     const char *str, size_t slen)
810 {
811 	char *ptr, *eptr = buf + bufsiz - 1;
812 	const unsigned char *s = RCAST(const unsigned char *, str);
813 	const unsigned char *es = s + slen;
814 
815 	for (ptr = buf;  ptr < eptr && s < es && *s; s++) {
816 		if ((ms->flags & MAGIC_RAW) != 0 ||
817 		    (isprint(*s) && !isspace(*s))) {
818 			*ptr++ = *s;
819 			continue;
820 		}
821 		if (ptr >= eptr - 3)
822 			break;
823 		*ptr++ = '\\';
824 		*ptr++ = ((CAST(unsigned int, *s) >> 6) & 7) + '0';
825 		*ptr++ = ((CAST(unsigned int, *s) >> 3) & 7) + '0';
826 		*ptr++ = ((CAST(unsigned int, *s) >> 0) & 7) + '0';
827 	}
828 	*ptr = '\0';
829 	return buf;
830 }
831 
832 struct guid {
833 	uint32_t data1;
834 	uint16_t data2;
835 	uint16_t data3;
836 	uint8_t data4[8];
837 };
838 
839 protected int
840 file_parse_guid(const char *s, uint64_t *guid)
841 {
842 	struct guid *g = CAST(struct guid *, CAST(void *, guid));
843 #ifndef WIN32
844 	return sscanf(s,
845 	    "%8x-%4hx-%4hx-%2hhx%2hhx-%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx",
846 	    &g->data1, &g->data2, &g->data3, &g->data4[0], &g->data4[1],
847 	    &g->data4[2], &g->data4[3], &g->data4[4], &g->data4[5],
848 	    &g->data4[6], &g->data4[7]) == 11 ? 0 : -1;
849 #else
850 	/* MS-Windows runtime doesn't support %hhx, except under
851 	   non-default __USE_MINGW_ANSI_STDIO.  */
852 	uint16_t data16[8];
853 	int rv = sscanf(s, "%8x-%4hx-%4hx-%2hx%2hx-%2hx%2hx%2hx%2hx%2hx%2hx",
854 	    &g->data1, &g->data2, &g->data3, &data16[0], &data16[1],
855 	    &data16[2], &data16[3], &data16[4], &data16[5],
856 	    &data16[6], &data16[7]) == 11 ? 0 : -1;
857 	int i;
858 	for (i = 0; i < 8; i++)
859 	    g->data4[i] = data16[i];
860 	return rv;
861 #endif
862 }
863 
864 protected int
865 file_print_guid(char *str, size_t len, const uint64_t *guid)
866 {
867 	const struct guid *g = CAST(const struct guid *,
868 	    CAST(const void *, guid));
869 
870 #ifndef WIN32
871 	return snprintf(str, len, "%.8X-%.4hX-%.4hX-%.2hhX%.2hhX-"
872 	    "%.2hhX%.2hhX%.2hhX%.2hhX%.2hhX%.2hhX",
873 	    g->data1, g->data2, g->data3, g->data4[0], g->data4[1],
874 	    g->data4[2], g->data4[3], g->data4[4], g->data4[5],
875 	    g->data4[6], g->data4[7]);
876 #else
877 	return snprintf(str, len, "%.8X-%.4hX-%.4hX-%.2hX%.2hX-"
878 	    "%.2hX%.2hX%.2hX%.2hX%.2hX%.2hX",
879 	    g->data1, g->data2, g->data3, g->data4[0], g->data4[1],
880 	    g->data4[2], g->data4[3], g->data4[4], g->data4[5],
881 	    g->data4[6], g->data4[7]);
882 #endif
883 }
884 
885 protected int
886 file_pipe_closexec(int *fds)
887 {
888 #ifdef HAVE_PIPE2
889 	return pipe2(fds, O_CLOEXEC);
890 #else
891 	if (pipe(fds) == -1)
892 		return -1;
893 # ifdef F_SETFD
894 	(void)fcntl(fds[0], F_SETFD, FD_CLOEXEC);
895 	(void)fcntl(fds[1], F_SETFD, FD_CLOEXEC);
896 # endif
897 	return 0;
898 #endif
899 }
900 
901 protected int
902 file_clear_closexec(int fd) {
903 #ifdef F_SETFD
904 	return fcntl(fd, F_SETFD, 0);
905 #else
906 	return 0;
907 #endif
908 }
909 
910 protected char *
911 file_strtrim(char *str)
912 {
913 	char *last;
914 
915 	while (isspace(CAST(unsigned char, *str)))
916 		str++;
917 	last = str;
918 	while (*last)
919 		last++;
920 	--last;
921 	while (isspace(CAST(unsigned char, *last)))
922 		last--;
923 	*++last = '\0';
924 	return str;
925 }
926