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
30FILE_RCSID("@(#)$File: funcs.c,v 1.140 2023/05/21 17:08:34 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#ifdef HAVE_UNISTD_H
40#include <unistd.h>	/* for pipe2() */
41#endif
42#if defined(HAVE_WCHAR_H)
43#include <wchar.h>
44#endif
45#if defined(HAVE_WCTYPE_H)
46#include <wctype.h>
47#endif
48#include <limits.h>
49
50#ifndef SIZE_MAX
51#define SIZE_MAX	((size_t)~0)
52#endif
53
54file_protected char *
55file_copystr(char *buf, size_t blen, size_t width, const char *str)
56{
57	if (blen == 0)
58		return buf;
59	if (width >= blen)
60		width = blen - 1;
61	memcpy(buf, str, width);
62	buf[width] = '\0';
63	return buf;
64}
65
66file_private void
67file_clearbuf(struct magic_set *ms)
68{
69	free(ms->o.buf);
70	ms->o.buf = NULL;
71	ms->o.blen = 0;
72}
73
74file_private int
75file_checkfield(char *msg, size_t mlen, const char *what, const char **pp)
76{
77	const char *p = *pp;
78	int fw = 0;
79
80	while (*p && isdigit((unsigned char)*p))
81		fw = fw * 10 + (*p++ - '0');
82
83	*pp = p;
84
85	if (fw < 1024)
86		return 1;
87	if (msg)
88		snprintf(msg, mlen, "field %s too large: %d", what, fw);
89
90	return 0;
91}
92
93file_protected int
94file_checkfmt(char *msg, size_t mlen, const char *fmt)
95{
96	const char *p;
97	for (p = fmt; *p; p++) {
98		if (*p != '%')
99			continue;
100		if (*++p == '%')
101			continue;
102		// Skip uninteresting.
103		while (strchr("#0.'+- ", *p) != NULL)
104			p++;
105		if (*p == '*') {
106			if (msg)
107				snprintf(msg, mlen, "* not allowed in format");
108			return -1;
109		}
110
111		if (!file_checkfield(msg, mlen, "width", &p))
112			return -1;
113
114		if (*p == '.') {
115			p++;
116			if (!file_checkfield(msg, mlen, "precision", &p))
117				return -1;
118		}
119
120		if (!isalpha((unsigned char)*p)) {
121			if (msg)
122				snprintf(msg, mlen, "bad format char: %c", *p);
123			return -1;
124		}
125	}
126	return 0;
127}
128
129/*
130 * Like printf, only we append to a buffer.
131 */
132file_protected int
133file_vprintf(struct magic_set *ms, const char *fmt, va_list ap)
134{
135	int len;
136	char *buf, *newstr;
137	char tbuf[1024];
138
139	if (ms->event_flags & EVENT_HAD_ERR)
140		return 0;
141
142	if (file_checkfmt(tbuf, sizeof(tbuf), fmt)) {
143		file_clearbuf(ms);
144		file_error(ms, 0, "Bad magic format `%s' (%s)", fmt, tbuf);
145		return -1;
146	}
147
148	len = vasprintf(&buf, fmt, ap);
149	if (len < 0 || (size_t)len > 1024 || len + ms->o.blen > 1024 * 1024) {
150		size_t blen = ms->o.blen;
151		free(buf);
152		file_clearbuf(ms);
153		file_error(ms, 0, "Output buffer space exceeded %d+%"
154		    SIZE_T_FORMAT "u", len, blen);
155		return -1;
156	}
157
158	if (ms->o.buf != NULL) {
159		len = asprintf(&newstr, "%s%s", ms->o.buf, buf);
160		free(buf);
161		if (len < 0)
162			goto out;
163		free(ms->o.buf);
164		buf = newstr;
165	}
166	ms->o.buf = buf;
167	ms->o.blen = len;
168	return 0;
169out:
170	file_clearbuf(ms);
171	file_error(ms, errno, "vasprintf failed");
172	return -1;
173}
174
175file_protected int
176file_printf(struct magic_set *ms, const char *fmt, ...)
177{
178	int rv;
179	va_list ap;
180
181	va_start(ap, fmt);
182	rv = file_vprintf(ms, fmt, ap);
183	va_end(ap);
184	return rv;
185}
186
187/*
188 * error - print best error message possible
189 */
190/*VARARGS*/
191__attribute__((__format__(__printf__, 3, 0)))
192file_private void
193file_error_core(struct magic_set *ms, int error, const char *f, va_list va,
194    size_t lineno)
195{
196	/* Only the first error is ok */
197	if (ms->event_flags & EVENT_HAD_ERR)
198		return;
199	if (lineno != 0) {
200		file_clearbuf(ms);
201		(void)file_printf(ms, "line %" SIZE_T_FORMAT "u:", lineno);
202	}
203	if (ms->o.buf && *ms->o.buf)
204		(void)file_printf(ms, " ");
205	(void)file_vprintf(ms, f, va);
206	if (error > 0)
207		(void)file_printf(ms, " (%s)", strerror(error));
208	ms->event_flags |= EVENT_HAD_ERR;
209	ms->error = error;
210}
211
212/*VARARGS*/
213file_protected void
214file_error(struct magic_set *ms, int error, const char *f, ...)
215{
216	va_list va;
217	va_start(va, f);
218	file_error_core(ms, error, f, va, 0);
219	va_end(va);
220}
221
222/*
223 * Print an error with magic line number.
224 */
225/*VARARGS*/
226file_protected void
227file_magerror(struct magic_set *ms, const char *f, ...)
228{
229	va_list va;
230	va_start(va, f);
231	file_error_core(ms, 0, f, va, ms->line);
232	va_end(va);
233}
234
235file_protected void
236file_oomem(struct magic_set *ms, size_t len)
237{
238	file_error(ms, errno, "cannot allocate %" SIZE_T_FORMAT "u bytes",
239	    len);
240}
241
242file_protected void
243file_badseek(struct magic_set *ms)
244{
245	file_error(ms, errno, "error seeking");
246}
247
248file_protected void
249file_badread(struct magic_set *ms)
250{
251	file_error(ms, errno, "error reading");
252}
253
254#ifndef COMPILE_ONLY
255#define FILE_SEPARATOR "\n- "
256
257file_protected int
258file_separator(struct magic_set *ms)
259{
260	return file_printf(ms, FILE_SEPARATOR);
261}
262
263static void
264trim_separator(struct magic_set *ms)
265{
266	size_t l;
267
268	if (ms->o.buf == NULL)
269		return;
270
271	l = strlen(ms->o.buf);
272	if (l < sizeof(FILE_SEPARATOR))
273		return;
274
275	l -= sizeof(FILE_SEPARATOR) - 1;
276	if (strcmp(ms->o.buf + l, FILE_SEPARATOR) != 0)
277		return;
278
279	ms->o.buf[l] = '\0';
280}
281
282static int
283checkdone(struct magic_set *ms, int *rv)
284{
285	if ((ms->flags & MAGIC_CONTINUE) == 0)
286		return 1;
287	if (file_separator(ms) == -1)
288		*rv = -1;
289	return 0;
290}
291
292file_protected int
293file_default(struct magic_set *ms, size_t nb)
294{
295	if (ms->flags & MAGIC_MIME) {
296		if ((ms->flags & MAGIC_MIME_TYPE) &&
297		    file_printf(ms, "application/%s",
298			nb ? "octet-stream" : "x-empty") == -1)
299			return -1;
300		return 1;
301	}
302	if (ms->flags & MAGIC_APPLE) {
303		if (file_printf(ms, "UNKNUNKN") == -1)
304			return -1;
305		return 1;
306	}
307	if (ms->flags & MAGIC_EXTENSION) {
308		if (file_printf(ms, "???") == -1)
309			return -1;
310		return 1;
311	}
312	return 0;
313}
314
315/*
316 * The magic detection functions return:
317 *	 1: found
318 *	 0: not found
319 *	-1: error
320 */
321/*ARGSUSED*/
322file_protected int
323file_buffer(struct magic_set *ms, int fd, struct stat *st,
324    const char *inname __attribute__ ((__unused__)),
325    const void *buf, size_t nb)
326{
327	int m = 0, rv = 0, looks_text = 0;
328	const char *code = NULL;
329	const char *code_mime = "binary";
330	const char *def = "data";
331	const char *ftype = NULL;
332	char *rbuf = NULL;
333	struct buffer b;
334
335	buffer_init(&b, fd, st, buf, nb);
336	ms->mode = b.st.st_mode;
337
338	if (nb == 0) {
339		def = "empty";
340		goto simple;
341	} else if (nb == 1) {
342		def = "very short file (no magic)";
343		goto simple;
344	}
345
346	if ((ms->flags & MAGIC_NO_CHECK_ENCODING) == 0) {
347		looks_text = file_encoding(ms, &b, NULL, 0,
348		    &code, &code_mime, &ftype);
349	}
350
351#ifdef __EMX__
352	if ((ms->flags & MAGIC_NO_CHECK_APPTYPE) == 0 && inname) {
353		m = file_os2_apptype(ms, inname, &b);
354		if ((ms->flags & MAGIC_DEBUG) != 0)
355			(void)fprintf(stderr, "[try os2_apptype %d]\n", m);
356		switch (m) {
357		case -1:
358			return -1;
359		case 0:
360			break;
361		default:
362			return 1;
363		}
364	}
365#endif
366#if HAVE_FORK
367	/* try compression stuff */
368	if ((ms->flags & MAGIC_NO_CHECK_COMPRESS) == 0) {
369		m = file_zmagic(ms, &b, inname);
370		if ((ms->flags & MAGIC_DEBUG) != 0)
371			(void)fprintf(stderr, "[try zmagic %d]\n", m);
372		if (m) {
373			goto done_encoding;
374		}
375	}
376#endif
377	/* Check if we have a tar file */
378	if ((ms->flags & MAGIC_NO_CHECK_TAR) == 0) {
379		m = file_is_tar(ms, &b);
380		if ((ms->flags & MAGIC_DEBUG) != 0)
381			(void)fprintf(stderr, "[try tar %d]\n", m);
382		if (m) {
383			if (checkdone(ms, &rv))
384				goto done;
385		}
386	}
387
388	/* Check if we have a JSON file */
389	if ((ms->flags & MAGIC_NO_CHECK_JSON) == 0) {
390		m = file_is_json(ms, &b);
391		if ((ms->flags & MAGIC_DEBUG) != 0)
392			(void)fprintf(stderr, "[try json %d]\n", m);
393		if (m) {
394			if (checkdone(ms, &rv))
395				goto done;
396		}
397	}
398
399	/* Check if we have a CSV file */
400	if ((ms->flags & MAGIC_NO_CHECK_CSV) == 0) {
401		m = file_is_csv(ms, &b, looks_text, code);
402		if ((ms->flags & MAGIC_DEBUG) != 0)
403			(void)fprintf(stderr, "[try csv %d]\n", m);
404		if (m) {
405			if (checkdone(ms, &rv))
406				goto done;
407		}
408	}
409
410	/* Check if we have a SIMH tape file */
411	if ((ms->flags & MAGIC_NO_CHECK_SIMH) == 0) {
412		m = file_is_simh(ms, &b);
413		if ((ms->flags & MAGIC_DEBUG) != 0)
414			(void)fprintf(stderr, "[try simh %d]\n", m);
415		if (m) {
416			if (checkdone(ms, &rv))
417				goto done;
418		}
419	}
420
421	/* Check if we have a CDF file */
422	if ((ms->flags & MAGIC_NO_CHECK_CDF) == 0) {
423		m = file_trycdf(ms, &b);
424		if ((ms->flags & MAGIC_DEBUG) != 0)
425			(void)fprintf(stderr, "[try cdf %d]\n", m);
426		if (m) {
427			if (checkdone(ms, &rv))
428				goto done;
429		}
430	}
431#ifdef BUILTIN_ELF
432	if ((ms->flags & MAGIC_NO_CHECK_ELF) == 0 && nb > 5 && fd != -1) {
433		file_pushbuf_t *pb;
434		/*
435		 * We matched something in the file, so this
436		 * *might* be an ELF file, and the file is at
437		 * least 5 bytes long, so if it's an ELF file
438		 * it has at least one byte past the ELF magic
439		 * number - try extracting information from the
440		 * ELF headers that cannot easily be  extracted
441		 * with rules in the magic file. We we don't
442		 * print the information yet.
443		 */
444		if ((pb = file_push_buffer(ms)) == NULL)
445			return -1;
446
447		rv = file_tryelf(ms, &b);
448		rbuf = file_pop_buffer(ms, pb);
449		if (rv == -1) {
450			free(rbuf);
451			rbuf = NULL;
452		}
453		if ((ms->flags & MAGIC_DEBUG) != 0)
454			(void)fprintf(stderr, "[try elf %d]\n", m);
455	}
456#endif
457
458	/* try soft magic tests */
459	if ((ms->flags & MAGIC_NO_CHECK_SOFT) == 0) {
460		m = file_softmagic(ms, &b, NULL, NULL, BINTEST, looks_text);
461		if ((ms->flags & MAGIC_DEBUG) != 0)
462			(void)fprintf(stderr, "[try softmagic %d]\n", m);
463		if (m == 1 && rbuf) {
464			if (file_printf(ms, "%s", rbuf) == -1)
465				goto done;
466		}
467		if (m) {
468			if (checkdone(ms, &rv))
469				goto done;
470		}
471	}
472
473	/* try text properties */
474	if ((ms->flags & MAGIC_NO_CHECK_TEXT) == 0) {
475
476		m = file_ascmagic(ms, &b, looks_text);
477		if ((ms->flags & MAGIC_DEBUG) != 0)
478			(void)fprintf(stderr, "[try ascmagic %d]\n", m);
479		if (m) {
480			goto done;
481		}
482	}
483
484simple:
485	/* give up */
486	if (m == 0) {
487		m = 1;
488		rv = file_default(ms, nb);
489		if (rv == 0)
490			if (file_printf(ms, "%s", def) == -1)
491				rv = -1;
492	}
493 done:
494	trim_separator(ms);
495	if ((ms->flags & MAGIC_MIME_ENCODING) != 0) {
496		if (ms->flags & MAGIC_MIME_TYPE)
497			if (file_printf(ms, "; charset=") == -1)
498				rv = -1;
499		if (file_printf(ms, "%s", code_mime) == -1)
500			rv = -1;
501	}
502#if HAVE_FORK
503 done_encoding:
504#endif
505	free(rbuf);
506	buffer_fini(&b);
507	if (rv)
508		return rv;
509
510	return m;
511}
512#endif
513
514file_protected int
515file_reset(struct magic_set *ms, int checkloaded)
516{
517	if (checkloaded && ms->mlist[0] == NULL) {
518		file_error(ms, 0, "no magic files loaded");
519		return -1;
520	}
521	file_clearbuf(ms);
522	if (ms->o.pbuf) {
523		free(ms->o.pbuf);
524		ms->o.pbuf = NULL;
525	}
526	ms->event_flags &= ~EVENT_HAD_ERR;
527	ms->error = -1;
528	return 0;
529}
530
531#define OCTALIFY(n, o)	\
532	/*LINTED*/ \
533	(void)(*(n)++ = '\\', \
534	*(n)++ = ((CAST(uint32_t, *(o)) >> 6) & 3) + '0', \
535	*(n)++ = ((CAST(uint32_t, *(o)) >> 3) & 7) + '0', \
536	*(n)++ = ((CAST(uint32_t, *(o)) >> 0) & 7) + '0', \
537	(o)++)
538
539file_protected const char *
540file_getbuffer(struct magic_set *ms)
541{
542	char *pbuf, *op, *np;
543	size_t psize, len;
544
545	if (ms->event_flags & EVENT_HAD_ERR)
546		return NULL;
547
548	if (ms->flags & MAGIC_RAW)
549		return ms->o.buf;
550
551	if (ms->o.buf == NULL)
552		return NULL;
553
554	/* * 4 is for octal representation, + 1 is for NUL */
555	len = strlen(ms->o.buf);
556	if (len > (SIZE_MAX - 1) / 4) {
557		file_oomem(ms, len);
558		return NULL;
559	}
560	psize = len * 4 + 1;
561	if ((pbuf = CAST(char *, realloc(ms->o.pbuf, psize))) == NULL) {
562		file_oomem(ms, psize);
563		return NULL;
564	}
565	ms->o.pbuf = pbuf;
566
567#if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH)
568	{
569		mbstate_t state;
570		wchar_t nextchar;
571		int mb_conv = 1;
572		size_t bytesconsumed;
573		char *eop;
574		(void)memset(&state, 0, sizeof(mbstate_t));
575
576		np = ms->o.pbuf;
577		op = ms->o.buf;
578		eop = op + len;
579
580		while (op < eop) {
581			bytesconsumed = mbrtowc(&nextchar, op,
582			    CAST(size_t, eop - op), &state);
583			if (bytesconsumed == CAST(size_t, -1) ||
584			    bytesconsumed == CAST(size_t, -2)) {
585				mb_conv = 0;
586				break;
587			}
588
589			if (iswprint(nextchar)) {
590				(void)memcpy(np, op, bytesconsumed);
591				op += bytesconsumed;
592				np += bytesconsumed;
593			} else {
594				while (bytesconsumed-- > 0)
595					OCTALIFY(np, op);
596			}
597		}
598		*np = '\0';
599
600		/* Parsing succeeded as a multi-byte sequence */
601		if (mb_conv != 0)
602			return ms->o.pbuf;
603	}
604#endif
605
606	for (np = ms->o.pbuf, op = ms->o.buf; *op;) {
607		if (isprint(CAST(unsigned char, *op))) {
608			*np++ = *op++;
609		} else {
610			OCTALIFY(np, op);
611		}
612	}
613	*np = '\0';
614	return ms->o.pbuf;
615}
616
617file_protected int
618file_check_mem(struct magic_set *ms, unsigned int level)
619{
620	size_t len;
621
622	if (level >= ms->c.len) {
623		len = (ms->c.len = 20 + level) * sizeof(*ms->c.li);
624		ms->c.li = CAST(struct level_info *, (ms->c.li == NULL) ?
625		    malloc(len) :
626		    realloc(ms->c.li, len));
627		if (ms->c.li == NULL) {
628			file_oomem(ms, len);
629			return -1;
630		}
631	}
632	ms->c.li[level].got_match = 0;
633#ifdef ENABLE_CONDITIONALS
634	ms->c.li[level].last_match = 0;
635	ms->c.li[level].last_cond = COND_NONE;
636#endif /* ENABLE_CONDITIONALS */
637	return 0;
638}
639
640file_protected size_t
641file_printedlen(const struct magic_set *ms)
642{
643	return ms->o.blen;
644}
645
646file_protected int
647file_replace(struct magic_set *ms, const char *pat, const char *rep)
648{
649	file_regex_t rx;
650	int rc, rv = -1;
651
652	rc = file_regcomp(ms, &rx, pat, REG_EXTENDED);
653	if (rc == 0) {
654		regmatch_t rm;
655		int nm = 0;
656		while (file_regexec(ms, &rx, ms->o.buf, 1, &rm, 0) == 0) {
657			ms->o.buf[rm.rm_so] = '\0';
658			if (file_printf(ms, "%s%s", rep,
659			    rm.rm_eo != 0 ? ms->o.buf + rm.rm_eo : "") == -1)
660				goto out;
661			nm++;
662		}
663		rv = nm;
664	}
665out:
666	file_regfree(&rx);
667	return rv;
668}
669
670file_private int
671check_regex(struct magic_set *ms, const char *pat)
672{
673	char sbuf[512];
674	unsigned char oc = '\0';
675	const char *p;
676
677	for (p = pat; *p; p++) {
678		unsigned char c = *p;
679		// Avoid repetition
680		if (c == oc && strchr("?*+{", c) != NULL) {
681			size_t len = strlen(pat);
682			file_magwarn(ms,
683			    "repetition-operator operand `%c' "
684			    "invalid in regex `%s'", c,
685			    file_printable(ms, sbuf, sizeof(sbuf), pat, len));
686			return -1;
687		}
688		oc = c;
689		if (isprint(c) || isspace(c) || c == '\b'
690		    || c == 0x8a) // XXX: apple magic fixme
691			continue;
692		size_t len = strlen(pat);
693		file_magwarn(ms,
694		    "non-ascii characters in regex \\%#o `%s'",
695		    c, file_printable(ms, sbuf, sizeof(sbuf), pat, len));
696		return -1;
697	}
698	return 0;
699}
700
701file_protected int
702file_regcomp(struct magic_set *ms file_locale_used, file_regex_t *rx,
703    const char *pat, int flags)
704{
705	if (check_regex(ms, pat) == -1)
706		return -1;
707
708#ifdef USE_C_LOCALE
709	locale_t old = uselocale(ms->c_lc_ctype);
710	assert(old != NULL);
711#else
712	char old[1024];
713	strlcpy(old, setlocale(LC_CTYPE, NULL), sizeof(old));
714	(void)setlocale(LC_CTYPE, "C");
715#endif
716	int rc;
717	rc = regcomp(rx, pat, flags);
718
719#ifdef USE_C_LOCALE
720	uselocale(old);
721#else
722	(void)setlocale(LC_CTYPE, old);
723#endif
724	if (rc > 0 && (ms->flags & MAGIC_CHECK)) {
725		char errmsg[512], buf[512];
726
727		(void)regerror(rc, rx, errmsg, sizeof(errmsg));
728		file_magerror(ms, "regex error %d for `%s', (%s)", rc,
729		    file_printable(ms, buf, sizeof(buf), pat, strlen(pat)),
730		    errmsg);
731	}
732	return rc;
733}
734
735/*ARGSUSED*/
736file_protected int
737file_regexec(struct magic_set *ms file_locale_used, file_regex_t *rx,
738    const char *str, size_t nmatch, regmatch_t* pmatch, int eflags)
739{
740#ifdef USE_C_LOCALE
741	locale_t old = uselocale(ms->c_lc_ctype);
742	assert(old != NULL);
743#else
744	char old[1024];
745	strlcpy(old, setlocale(LC_CTYPE, NULL), sizeof(old));
746	(void)setlocale(LC_CTYPE, "C");
747#endif
748	int rc;
749	/* XXX: force initialization because glibc does not always do this */
750	if (nmatch != 0)
751		memset(pmatch, 0, nmatch * sizeof(*pmatch));
752	rc = regexec(rx, str, nmatch, pmatch, eflags);
753#ifdef USE_C_LOCALE
754	uselocale(old);
755#else
756	(void)setlocale(LC_CTYPE, old);
757#endif
758	return rc;
759}
760
761file_protected void
762file_regfree(file_regex_t *rx)
763{
764	regfree(rx);
765}
766
767file_protected file_pushbuf_t *
768file_push_buffer(struct magic_set *ms)
769{
770	file_pushbuf_t *pb;
771
772	if (ms->event_flags & EVENT_HAD_ERR)
773		return NULL;
774
775	if ((pb = (CAST(file_pushbuf_t *, malloc(sizeof(*pb))))) == NULL)
776		return NULL;
777
778	pb->buf = ms->o.buf;
779	pb->blen = ms->o.blen;
780	pb->offset = ms->offset;
781
782	ms->o.buf = NULL;
783	ms->o.blen = 0;
784	ms->offset = 0;
785
786	return pb;
787}
788
789file_protected char *
790file_pop_buffer(struct magic_set *ms, file_pushbuf_t *pb)
791{
792	char *rbuf;
793
794	if (ms->event_flags & EVENT_HAD_ERR) {
795		free(pb->buf);
796		free(pb);
797		return NULL;
798	}
799
800	rbuf = ms->o.buf;
801
802	ms->o.buf = pb->buf;
803	ms->o.blen = pb->blen;
804	ms->offset = pb->offset;
805
806	free(pb);
807	return rbuf;
808}
809
810/*
811 * convert string to ascii printable format.
812 */
813file_protected char *
814file_printable(struct magic_set *ms, char *buf, size_t bufsiz,
815    const char *str, size_t slen)
816{
817	char *ptr, *eptr = buf + bufsiz - 1;
818	const unsigned char *s = RCAST(const unsigned char *, str);
819	const unsigned char *es = s + slen;
820
821	for (ptr = buf;  ptr < eptr && s < es && *s; s++) {
822		if ((ms->flags & MAGIC_RAW) != 0 || isprint(*s)) {
823			*ptr++ = *s;
824			continue;
825		}
826		if (ptr >= eptr - 3)
827			break;
828		*ptr++ = '\\';
829		*ptr++ = ((CAST(unsigned int, *s) >> 6) & 7) + '0';
830		*ptr++ = ((CAST(unsigned int, *s) >> 3) & 7) + '0';
831		*ptr++ = ((CAST(unsigned int, *s) >> 0) & 7) + '0';
832	}
833	*ptr = '\0';
834	return buf;
835}
836
837struct guid {
838	uint32_t data1;
839	uint16_t data2;
840	uint16_t data3;
841	uint8_t data4[8];
842};
843
844file_protected int
845file_parse_guid(const char *s, uint64_t *guid)
846{
847	struct guid *g = CAST(struct guid *, CAST(void *, guid));
848#ifndef WIN32
849	return sscanf(s,
850	    "%8x-%4hx-%4hx-%2hhx%2hhx-%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx",
851	    &g->data1, &g->data2, &g->data3, &g->data4[0], &g->data4[1],
852	    &g->data4[2], &g->data4[3], &g->data4[4], &g->data4[5],
853	    &g->data4[6], &g->data4[7]) == 11 ? 0 : -1;
854#else
855	/* MS-Windows runtime doesn't support %hhx, except under
856	   non-default __USE_MINGW_ANSI_STDIO.  */
857	uint16_t data16[8];
858	int rv = sscanf(s, "%8x-%4hx-%4hx-%2hx%2hx-%2hx%2hx%2hx%2hx%2hx%2hx",
859	    &g->data1, &g->data2, &g->data3, &data16[0], &data16[1],
860	    &data16[2], &data16[3], &data16[4], &data16[5],
861	    &data16[6], &data16[7]) == 11 ? 0 : -1;
862	int i;
863	for (i = 0; i < 8; i++)
864	    g->data4[i] = data16[i];
865	return rv;
866#endif
867}
868
869file_protected int
870file_print_guid(char *str, size_t len, const uint64_t *guid)
871{
872	const struct guid *g = CAST(const struct guid *,
873	    CAST(const void *, guid));
874
875#ifndef WIN32
876	return snprintf(str, len, "%.8X-%.4hX-%.4hX-%.2hhX%.2hhX-"
877	    "%.2hhX%.2hhX%.2hhX%.2hhX%.2hhX%.2hhX",
878	    g->data1, g->data2, g->data3, g->data4[0], g->data4[1],
879	    g->data4[2], g->data4[3], g->data4[4], g->data4[5],
880	    g->data4[6], g->data4[7]);
881#else
882	return snprintf(str, len, "%.8X-%.4hX-%.4hX-%.2hX%.2hX-"
883	    "%.2hX%.2hX%.2hX%.2hX%.2hX%.2hX",
884	    g->data1, g->data2, g->data3, g->data4[0], g->data4[1],
885	    g->data4[2], g->data4[3], g->data4[4], g->data4[5],
886	    g->data4[6], g->data4[7]);
887#endif
888}
889
890file_protected int
891file_pipe_closexec(int *fds)
892{
893#ifdef __MINGW32__
894	return 0;
895#elif defined(HAVE_PIPE2)
896	return pipe2(fds, O_CLOEXEC);
897#else
898	if (pipe(fds) == -1)
899		return -1;
900# ifdef F_SETFD
901	(void)fcntl(fds[0], F_SETFD, FD_CLOEXEC);
902	(void)fcntl(fds[1], F_SETFD, FD_CLOEXEC);
903# endif
904	return 0;
905#endif
906}
907
908file_protected int
909file_clear_closexec(int fd) {
910#ifdef F_SETFD
911	return fcntl(fd, F_SETFD, 0);
912#else
913	return 0;
914#endif
915}
916
917file_protected char *
918file_strtrim(char *str)
919{
920	char *last;
921
922	while (isspace(CAST(unsigned char, *str)))
923		str++;
924	last = str;
925	while (*last)
926		last++;
927	--last;
928	while (isspace(CAST(unsigned char, *last)))
929		last--;
930	*++last = '\0';
931	return str;
932}
933