wireshark/wiretap/file_wrappers.c
Jeff Morriss a5cee04fad Move the file utility functions from wiretap to libwsutil so that
libwireshark (and the plugins using those functions) do not depend on
wiretap on Windows.

While doing that, rename the eth_* functions to ws_*.

svn path=/trunk/; revision=25354
2008-05-22 15:46:27 +00:00

299 lines
8.3 KiB
C

/* file_wrappers.c
*
* $Id$
*
* Wiretap Library
* Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
/*
* Do this now, to get close() defined, before we muck with the definition
* of HAVE_UNISTD_H. See below for the full sad story of why we do that.
*/
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif /* HAVE_UNISTD_H */
/*
* OK, now this is tricky.
*
* At least on FreeBSD 3.2, "/usr/include/zlib.h" includes
* "/usr/include/zconf.h", which, if HAVE_UNISTD_H is defined,
* #defines "z_off_t" to be "off_t", and if HAVE_UNISTD_H is
* not defined, #defines "z_off_t" to be "long" if it's not
* already #defined.
*
* In 4.4-Lite-derived systems such as FreeBSD, "off_t" is
* "long long int", not "long int", so the definition of "z_off_t" -
* and therefore the types of the arguments to routines such as
* "gzseek()", as declared, with prototypes, in "zlib.h" - depends
* on whether HAVE_UNISTD_H is defined prior to including "zlib.h"!
*
* It's not defined in the FreeBSD 3.2 "zlib", so if we include "zlib.h"
* after defining HAVE_UNISTD_H, we get a misdeclaration of "gzseek()",
* and, if we're building with "zlib" support, anything that seeks
* on a file may not work.
*
* Other BSDs may have the same problem, if they haven't done something
* such as defining HAVE_UNISTD_H in "zconf.h".
*
* "config.h" defines HAVE_UNISTD_H, on all systems that have it, and all
* 4.4-Lite-derived BSDs have it. Therefore, given that "zlib.h" is included
* by "file_wrappers.h", that means that unless we include "zlib.h" before
* we include "config.h", we get a misdeclaration of "gzseek()".
*
* Unfortunately, it's "config.h" that tells us whether we have "zlib"
* in the first place, so we don't know whether to include "zlib.h"
* until we include "config.h"....
*
* A similar problem appears to occur with "gztell()", at least on
* NetBSD.
*
* To add further complication, on recent versions, at least, of OpenBSD,
* the Makefile for zlib defines HAVE_UNISTD_H.
*
* So what we do is, on all OSes other than OpenBSD, *undefine* HAVE_UNISTD_H
* before including "wtap-int.h" (it handles including "zlib.h" if HAVE_ZLIB
* is defined, and it includes "wtap.h", which we include to get the
* WTAP_ERR_ZLIB values), and, if we have zlib, make "file_seek()" and
* "file_tell()" subroutines, so that the only calls to "gzseek()" and
* "gztell()" are in this file, which, by dint of the hackery described
* above, manages to correctly declare "gzseek()" and "gztell()".
*
* On OpenBSD, we forcibly *define* HAVE_UNISTD_H if it's not defined.
*
* Hopefully, the BSDs will, over time, remove the test for HAVE_UNISTD_H
* from "zconf.h", so that "gzseek()" and "gztell()" will be declared
* with the correct signature regardless of whether HAVE_UNISTD_H is
* defined, so that if they change the signature we don't have to worry
* about making sure it's defined or not defined.
*
* DO NOT, UNDER ANY CIRCUMSTANCES, REMOVE THE FOLLOWING LINES, OR MOVE
* THEM AFTER THE INCLUDE OF "wtap-int.h"! Doing so will cause any program
* using Wiretap to read capture files to fail miserably on a FreeBSD
* 3.2 or 3.3 system - and possibly some other BSD systems - if zlib is
* installed. If you *must* have HAVE_UNISTD_H defined before including
* "wtap-int.h", put "file_error()" into a file by itself, which can
* cheerfully include "wtap.h" and get "gzseek()" misdeclared, and include
* just "zlib.h" in this file - *after* undefining HAVE_UNISTD_H.
*/
#ifdef __OpenBSD__
#ifndef HAVE_UNISTD_H
#define HAVE_UNISTD_H
#endif /* HAVE_UNISTD_H */
#else /* __OpenBSD__ */
#undef HAVE_UNISTD_H
#endif /* __OpenBSD__ */
#include <errno.h>
#include <stdio.h>
#ifdef HAVE_LIBZ
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif /* HAVE_FCNTL_H */
#include <string.h>
#endif /* HAVE_LIBZ */
#include "wtap-int.h"
#include "file_wrappers.h"
#include <wsutil/file_util.h>
#ifdef HAVE_LIBZ
FILE_T
file_open(const char *path, const char *mode)
{
int fd;
FILE_T ft;
int oflag;
if (*mode == 'r') {
if (strchr(mode + 1, '+') != NULL)
oflag = O_RDWR;
else
oflag = O_RDONLY;
} else if (*mode == 'w') {
if (strchr(mode + 1, '+') != NULL)
oflag = O_RDWR|O_CREAT|O_TRUNC;
else
oflag = O_RDONLY|O_CREAT|O_TRUNC;
} else if (*mode == 'a') {
if (strchr(mode + 1, '+') != NULL)
oflag = O_RDWR|O_APPEND;
else
oflag = O_RDONLY|O_APPEND;
} else {
errno = EINVAL;
return NULL;
}
#ifdef _WIN32
if (strchr(mode + 1, 'b') != NULL)
oflag |= O_BINARY;
#endif
/* open file and do correct filename conversions */
if ((fd = ws_open(path, oflag, 0666)) == -1)
return NULL;
/* open zlib file handle */
ft = gzdopen(fd, mode);
if (ft == NULL) {
ws_close(fd);
return NULL;
}
return ft;
}
gint64
file_seek(void *stream, gint64 offset, int whence, int *err)
{
gint64 ret;
/* XXX - z_off_t is usually long, won't work >= 2GB! */
ret = (gint64) gzseek(stream, (z_off_t)offset, whence);
if (ret == -1) {
/*
* XXX - "gzseek()", as of zlib 1.1.4, doesn't set
* "z_err" for the stream, so "gzerror()" could return
* a bogus Z_OK.
*
* As this call failed, we know "gzerror()" shouldn't
* return Z_OK; if it does, we assume that "errno" is
* the real error.
*/
*err = file_error(stream);
if (*err == 0)
*err = errno;
}
return ret;
}
gint64
file_tell(void *stream)
{
/* XXX - z_off_t is usually long, won't work >= 2GB! */
return (gint64)gztell(stream);
}
/*
* Routine to return a Wiretap error code (0 for no error, an errno
* for a file error, or a WTAP_ERR_ code for other errors) for an
* I/O stream.
*/
int
file_error(void *fh)
{
int errnum;
gzerror(fh, &errnum);
switch (errnum) {
case Z_OK: /* no error */
return 0;
case Z_STREAM_END: /* EOF - not an error */
return 0;
case Z_ERRNO: /* file I/O error */
return errno;
default:
return WTAP_ERR_ZLIB + errnum;
}
}
#else /* HAVE_LIBZ */
gint64
file_seek(void *stream, gint64 offset, int whence, int *err)
{
gint64 ret;
#ifdef _WIN32
gint64 pos;
#endif
#ifdef _WIN32
/* Win32 version using fsetpos/fgetpos */
/* XXX - using fsetpos/fgetpos this way is UNDOCUMENTED, but I don't see a any better way :-( */
/* _lseeki64(_fileno(stream)) doesn't work as this will mangle the internal FILE handling data */
switch(whence) {
case(SEEK_SET):
/* do nothing */
break;
case(SEEK_CUR):
/* adjust offset */
/* XXX - CURRENTLY UNTESTED!!! */
ret = fgetpos(stream, &pos);
if(ret != 0) {
*err = errno;
return ret;
}
offset += pos;
break;
case(SEEK_END):
default:
g_assert_not_reached();
}
ret = fsetpos(stream, &offset);
if(ret != 0) {
*err = errno;
}
/* XXX - won't work >= 2GB! */
/*ret = (gint64) fseek(stream, (long) offset, whence);
if(ret == -1) {
*err = errno;
}*/
#else
/* "basic" version using fseek */
/* XXX - won't work >= 2GB! */
ret = (gint64) fseek(stream, (long) offset, whence);
if (ret == -1)
*err = file_error(stream);
#endif
/*g_warning("Seek %" G_GINT64_MODIFIER "d whence %u ret %" G_GINT64_MODIFIER "d size %u", offset, whence, ret, sizeof(fpos_t));*/
return ret;
}
gint64
file_tell(void *stream)
{
#ifdef _WIN32
/* Win32 version using _telli64 */
/* XXX - CURRENTLY UNTESTED!!! */
return _telli64(_fileno((FILE *)stream));
#else
/* "basic" version using ftell */
/* XXX - ftell returns a long - won't work >= 2GB! */
return (gint64) ftell(stream);
#endif
}
int
file_error(void *fh)
{
if (ferror((FILE *) fh))
return errno;
else
return 0;
}
#endif /* HAVE_LIBZ */