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rcsid[] and sccsid[] and copyright[] are essentially unmaintained (and
unmaintainable).  these days, people use source.  these id's do not provide
any benefit, and do hurt the small install media
(the 33,000 line diff is essentially mechanical)
ok with the idea millert, ok dms

/* $OpenBSD: funcs.c,v 1.7 2009/10/27 23:59:37 deraadt Exp $ */
/*
 * Copyright (c) Christos Zoulas 2003.
 * All Rights Reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice immediately at the beginning of the file, without modification,
 *    this list of conditions, and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *  
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#include "file.h"
#include "magic.h"
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#if defined(HAVE_WCHAR_H)
#include <wchar.h>
#endif
#if defined(HAVE_WCTYPE_H)
#include <wctype.h>
#endif

/*
 * Like printf, only we append to a buffer.
 */
protected int
file_printf(struct magic_set *ms, const char *fmt, ...)
{
	va_list ap;
	int len;
	char *buf, *newstr;

	va_start(ap, fmt);
	len = vasprintf(&buf, fmt, ap);
	if (len < 0)
		goto out;
	va_end(ap);

	if (ms->o.buf != NULL) {
		len = asprintf(&newstr, "%s%s", ms->o.buf, buf);
		free(buf);
		if (len < 0)
			goto out;
		free(ms->o.buf);
		buf = newstr;
	}
	ms->o.buf = buf;
	return 0;
out:
	file_error(ms, errno, "vasprintf failed");
	return -1;
}

/*
 * error - print best error message possible
 */
/*VARARGS*/
private void
file_error_core(struct magic_set *ms, int error, const char *f, va_list va,
    uint32_t lineno)
{
	/* Only the first error is ok */
	if (ms->haderr)
		return;
	if (lineno != 0) {
		free(ms->o.buf);
		ms->o.buf = NULL;
		file_printf(ms, "line %u: ", lineno);
	}
        file_printf(ms, f, va);
	if (error > 0)
		file_printf(ms, " (%s)", strerror(error));
	ms->haderr++;
	ms->error = error;
}

/*VARARGS*/
protected void
file_error(struct magic_set *ms, int error, const char *f, ...)
{
	va_list va;
	va_start(va, f);
	file_error_core(ms, error, f, va, 0);
	va_end(va);
}

/*
 * Print an error with magic line number.
 */
/*VARARGS*/
protected void
file_magerror(struct magic_set *ms, const char *f, ...)
{
	va_list va;
	va_start(va, f);
	file_error_core(ms, 0, f, va, ms->line);
	va_end(va);
}

protected void
file_oomem(struct magic_set *ms, size_t len)
{
	file_error(ms, errno, "cannot allocate %zu bytes", len);
}

protected void
file_badseek(struct magic_set *ms)
{
	file_error(ms, errno, "error seeking");
}

protected void
file_badread(struct magic_set *ms)
{
	file_error(ms, errno, "error reading");
}

#ifndef COMPILE_ONLY
protected int
file_buffer(struct magic_set *ms, int fd, const char *inname, const void *buf,
    size_t nb)
{
	int m;
	int mime = ms->flags & MAGIC_MIME;

	if (nb == 0) {
		if ((!mime || (mime & MAGIC_MIME_TYPE)) &&
		    file_printf(ms, mime ? "application/x-empty" :
		    "empty") == -1)
			return -1;
		return 1;
	} else if (nb == 1) {
		if ((!mime || (mime & MAGIC_MIME_TYPE)) &&
		    file_printf(ms, mime ? "application/octet-stream" :
		    "very short file (no magic)") == -1)
			return -1;
		return 1;
	}

#ifdef __EMX__
	if ((ms->flags & MAGIC_NO_CHECK_APPTYPE) == 0 && inname) {
		switch (file_os2_apptype(ms, inname, buf, nb)) {
		case -1:
			return -1;
		case 0:
			break;
		default:
			return 1;
		}
	}
#endif

	/* try compression stuff */
	if ((ms->flags & MAGIC_NO_CHECK_COMPRESS) != 0 ||
	    (m = file_zmagic(ms, fd, inname, buf, nb)) == 0) {
	    /* Check if we have a tar file */
	    if ((ms->flags & MAGIC_NO_CHECK_TAR) != 0 ||
		(m = file_is_tar(ms, buf, nb)) == 0) {
		/* try tests in /etc/magic (or surrogate magic file) */
		if ((ms->flags & MAGIC_NO_CHECK_SOFT) != 0 ||
		    (m = file_softmagic(ms, buf, nb, BINTEST)) == 0) {
		    /* try known keywords, check whether it is ASCII */
		    if ((ms->flags & MAGIC_NO_CHECK_ASCII) != 0 ||
			(m = file_ascmagic(ms, buf, nb)) == 0) {
			/* abandon hope, all ye who remain here */
			if ((!mime || (mime & MAGIC_MIME_TYPE)) &&
			    file_printf(ms, mime ? "application/octet-stream" :
				"data") == -1)
				return -1;
			m = 1;
		    }
		}
	    }
	}
#ifdef BUILTIN_ELF
	if ((ms->flags & MAGIC_NO_CHECK_ELF) == 0 && m == 1 &&
	    nb > 5 && fd != -1) {
		/*
		 * We matched something in the file, so this *might*
		 * be an ELF file, and the file is at least 5 bytes
		 * long, so if it's an ELF file it has at least one
		 * byte past the ELF magic number - try extracting
		 * information from the ELF headers that cannot easily
		 * be extracted with rules in the magic file.
		 */
		(void)file_tryelf(ms, fd, buf, nb);
	}
#endif
	return m;
}
#endif

protected int
file_reset(struct magic_set *ms)
{
	if (ms->mlist == NULL) {
		file_error(ms, 0, "no magic files loaded");
		return -1;
	}
	ms->o.buf = NULL;
	ms->haderr = 0;
	ms->error = -1;
	return 0;
}

#define OCTALIFY(n, o)	\
	/*LINTED*/ \
	(void)(*(n)++ = '\\', \
	*(n)++ = (((uint32_t)*(o) >> 6) & 3) + '0', \
	*(n)++ = (((uint32_t)*(o) >> 3) & 7) + '0', \
	*(n)++ = (((uint32_t)*(o) >> 0) & 7) + '0', \
	(o)++)

protected const char *
file_getbuffer(struct magic_set *ms)
{
	char *pbuf, *op, *np;
	size_t psize, len;

	if (ms->haderr)
		return NULL;

	if (ms->flags & MAGIC_RAW)
		return ms->o.buf;

	/* * 4 is for octal representation, + 1 is for NUL */
	len = strlen(ms->o.buf);
	if (len > (SIZE_MAX - 1) / 4) {
		file_oomem(ms, len);
		return NULL;
	}
	psize = len * 4 + 1;
	if ((pbuf = realloc(ms->o.pbuf, psize)) == NULL) {
		file_oomem(ms, psize);
		return NULL;
	}
	ms->o.pbuf = pbuf;

#if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH)
	{
		mbstate_t state;
		wchar_t nextchar;
		int mb_conv = 1;
		size_t bytesconsumed;
		char *eop;
		(void)memset(&state, 0, sizeof(mbstate_t));

		np = ms->o.pbuf;
		op = ms->o.buf;
		eop = op + len;

		while (op < eop) {
			bytesconsumed = mbrtowc(&nextchar, op,
			    (size_t)(eop - op), &state);
			if (bytesconsumed == (size_t)(-1) ||
			    bytesconsumed == (size_t)(-2)) {
				mb_conv = 0;
				break;
			}

			if (iswprint(nextchar)) {
				(void)memcpy(np, op, bytesconsumed);
				op += bytesconsumed;
				np += bytesconsumed;
			} else {
				while (bytesconsumed-- > 0)
					OCTALIFY(np, op);
			}
		}
		*np = '\0';

		/* Parsing succeeded as a multi-byte sequence */
		if (mb_conv != 0)
			return ms->o.pbuf;
	}
#endif

	for (np = ms->o.pbuf, op = ms->o.buf; *op; op++) {
		if (isprint((unsigned char)*op)) {
			*np++ = *op;	
		} else {
			OCTALIFY(np, op);
		}
	}
	*np = '\0';
	return ms->o.pbuf;
}

protected int
file_check_mem(struct magic_set *ms, unsigned int level)
{
	size_t len;

	if (level >= ms->c.len) {
		len = (ms->c.len += 20) * sizeof(*ms->c.li);
		ms->c.li = (ms->c.li == NULL) ? malloc(len) :
		    realloc(ms->c.li, len);
		if (ms->c.li == NULL) {
			file_oomem(ms, len);
			return -1;
		}
	}
	ms->c.li[level].got_match = 0;
#ifdef ENABLE_CONDITIONALS
	ms->c.li[level].last_match = 0;
	ms->c.li[level].last_cond = COND_NONE;
#endif /* ENABLE_CONDITIONALS */
	return 0;
}