HardenedBSD/contrib/file/funcs.c
2007-05-24 16:12:23 +00:00

269 lines
6.2 KiB
C

/*
* 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
#ifndef lint
FILE_RCSID("@(#)$Id: funcs.c,v 1.23 2006/12/11 21:48:49 christos Exp $")
#endif /* lint */
#ifndef HAVE_VSNPRINTF
int vsnprintf(char *, size_t, const char *, va_list);
#endif
/*
* Like printf, only we print to a buffer and advance it.
*/
protected int
file_printf(struct magic_set *ms, const char *fmt, ...)
{
va_list ap;
size_t len;
char *buf;
va_start(ap, fmt);
if ((len = vsnprintf(ms->o.ptr, ms->o.len, fmt, ap)) >= ms->o.len) {
va_end(ap);
if ((buf = realloc(ms->o.buf, len + 1024)) == NULL) {
file_oomem(ms, len + 1024);
return -1;
}
ms->o.ptr = buf + (ms->o.ptr - ms->o.buf);
ms->o.buf = buf;
ms->o.len = ms->o.size - (ms->o.ptr - ms->o.buf);
ms->o.size = len + 1024;
va_start(ap, fmt);
len = vsnprintf(ms->o.ptr, ms->o.len, fmt, ap);
}
ms->o.ptr += len;
ms->o.len -= len;
va_end(ap);
return 0;
}
/*
* error - print best error message possible
*/
/*VARARGS*/
protected void
file_error(struct magic_set *ms, int error, const char *f, ...)
{
va_list va;
/* Only the first error is ok */
if (ms->haderr)
return;
va_start(va, f);
(void)vsnprintf(ms->o.buf, ms->o.size, f, va);
va_end(va);
if (error > 0) {
size_t len = strlen(ms->o.buf);
(void)snprintf(ms->o.buf + len, ms->o.size - len, " (%s)",
strerror(error));
}
ms->haderr++;
ms->error = error;
}
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 void *buf, size_t nb)
{
int m;
/* try compression stuff */
if ((m = file_zmagic(ms, fd, buf, nb)) == 0) {
/* Check if we have a tar file */
if ((m = file_is_tar(ms, buf, nb)) == 0) {
/* try tests in /etc/magic (or surrogate magic file) */
if ((m = file_softmagic(ms, buf, nb)) == 0) {
/* try known keywords, check whether it is ASCII */
if ((m = file_ascmagic(ms, buf, nb)) == 0) {
/* abandon hope, all ye who remain here */
if (file_printf(ms, ms->flags & MAGIC_MIME ?
(nb ? "application/octet-stream" :
"application/empty") :
(nb ? "data" :
"empty")) == -1)
return -1;
m = 1;
}
}
}
}
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.ptr = ms->o.buf;
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 *nbuf, *op, *np;
size_t nsize;
if (ms->haderr)
return NULL;
if (ms->flags & MAGIC_RAW)
return ms->o.buf;
nsize = ms->o.len * 4 + 1;
if (ms->o.psize < nsize) {
if ((nbuf = realloc(ms->o.pbuf, nsize)) == NULL) {
file_oomem(ms, nsize);
return NULL;
}
ms->o.psize = nsize;
ms->o.pbuf = nbuf;
}
#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 + strlen(ms->o.buf);
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;
}
/*
* Yes these wrappers suffer from buffer overflows, but if your OS does not have
* the real functions, maybe you should consider replacing your OS?
*/
#ifndef HAVE_VSNPRINTF
int
vsnprintf(char *buf, size_t len, const char *fmt, va_list ap)
{
return vsprintf(buf, fmt, ap);
}
#endif
#ifndef HAVE_SNPRINTF
/*ARGSUSED*/
int
snprintf(char *buf, size_t len, const char *fmt, ...)
{
int rv;
va_list ap;
va_start(ap, fmt);
rv = vsprintf(buf, fmt, ap);
va_end(ap);
return rv;
}
#endif