![Guy Harris](/assets/img/avatar_default.png)
wtap_file_read_expected_bytes() from an open routine - open routines are supposed to return -1 on error, 0 if the file doesn't appear to be a file of the specified type, or 1 if the file does appear to be a file of the specified type, but those macros will cause the caller to return FALSE on errors (so that, even if there's an I/O error, it reports "the file isn't a file of the specified type" rather than "we got an error trying to read the file"). When doing reads in an open routine before we've concluded that the file is probably of the right type, return 0, rather than -1, if we get WTAP_ERR_SHORT_READ - if we don't have enough data to check whether a file is of a given type, we should keep trying other types, not give up. For reads done *after* we've concluded the file is probably of the right type, if a read doesn't return the number of bytes we asked for, but returns an error of 0, return WTAP_ERR_SHORT_READ - the file is apparently cut short. For NetMon and NetXRay/Windows Sniffer files, use a #define for the magic number size, and use that for both magic numbers. svn path=/trunk/; revision=46803
135 lines
3.3 KiB
C
135 lines
3.3 KiB
C
/* tnef.c
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*
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* Transport-Neutral Encapsulation Format (TNEF) file reading
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*
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* $Id$
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include "config.h"
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#include <errno.h>
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#ifdef HAVE_SYS_STAT_H
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#include <sys/stat.h>
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#endif
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#include "wtap-int.h"
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#include "file_wrappers.h"
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#include "buffer.h"
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#include "tnef.h"
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static gboolean tnef_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset)
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{
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gint64 offset;
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guint8 *buf;
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gint64 file_size;
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int packet_size;
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*err = 0;
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offset = file_tell(wth->fh);
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/* there is only ever one packet */
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if (offset)
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return FALSE;
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*data_offset = offset;
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if ((file_size = wtap_file_size(wth, err)) == -1)
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return FALSE;
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if (file_size > WTAP_MAX_PACKET_SIZE) {
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/*
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* Probably a corrupt capture file; don't blow up trying
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* to allocate space for an immensely-large packet.
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*/
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*err = WTAP_ERR_BAD_FILE;
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*err_info = g_strdup_printf("tnef: File has %" G_GINT64_MODIFIER "d-byte packet, bigger than maximum of %u",
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file_size, WTAP_MAX_PACKET_SIZE);
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return FALSE;
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}
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packet_size = (int)file_size;
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buffer_assure_space(wth->frame_buffer, packet_size);
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buf = buffer_start_ptr(wth->frame_buffer);
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wtap_file_read_expected_bytes(buf, packet_size, wth->fh, err, err_info);
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wth->phdr.presence_flags = 0; /* no time stamp, no "real length" */
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wth->phdr.caplen = packet_size;
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wth->phdr.len = packet_size;
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wth->phdr.ts.secs = 0;
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wth->phdr.ts.nsecs = 0;
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return TRUE;
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}
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static gboolean tnef_seek_read(wtap *wth, gint64 seek_off,
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struct wtap_pkthdr *phdr _U_,
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guint8 *pd, int length, int *err, gchar **err_info)
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{
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int packet_size = length;
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/* there is only one packet */
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if(seek_off > 0) {
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*err = 0;
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return FALSE;
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}
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if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
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return FALSE;
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wtap_file_read_expected_bytes(pd, packet_size, wth->random_fh, err, err_info);
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return TRUE;
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}
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int tnef_open(wtap *wth, int *err, gchar **err_info)
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{
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int bytes_read;
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guint32 magic;
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bytes_read = file_read(&magic, sizeof magic, wth->fh);
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if (bytes_read != sizeof magic) {
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*err = file_error(wth->fh, err_info);
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if (*err != 0 && *err != WTAP_ERR_SHORT_READ)
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return -1;
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return 0;
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}
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if (htolel(magic) != TNEF_SIGNATURE)
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/* Not a tnef file */
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return 0;
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/* seek back to the start of the file */
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if (file_seek(wth->fh, 0, SEEK_SET, err) == -1)
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return -1;
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wth->file_type = WTAP_FILE_TNEF;
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wth->file_encap = WTAP_ENCAP_TNEF;
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wth->snapshot_length = 0;
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wth->subtype_read = tnef_read;
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wth->subtype_seek_read = tnef_seek_read;
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wth->tsprecision = WTAP_FILE_TSPREC_SEC;
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return 1;
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}
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