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wireshark/wiretap/commview.c
Guy Harris b6ff142f60 Add a presence flag field to the packet information structure filled in 
by Wiretap, to indicate whether certain fields in that structure
actually have data in them.

Use the "time stamp present" flag to omit showing time stamp information
for packets (and "packets") that don't have time stamps; don't bother
working very hard to "fake" a time stamp for data files.

Use the "interface ID present" flag to omit the interface ID for packets
that don't have an interface ID.

We don't use the "captured length, separate from packet length, present"
flag to omit the captured length; that flag might be present but equal
to the packet length, and if you want to know if a packet was cut short
by a snapshot length, comparing the values would be the way to do that.

More work is needed to have wiretap/pcapng.c properly report the flags,
e.g. reporting no time stamp being present for a Simple Packet Block.

svn path=/trunk/; revision=41185
2012-02-25 23:24:34 +00:00

423 lines
12 KiB
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/* commview.c
* Routines for opening CommView file format packet captures
* Copyright 2007, Stephen Fisher (see AUTHORS file)
*
* $Id$
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* Based on csids.c and nettl.c
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*/
/* A brief description of this file format is available at:
* http://www.tamos.com/htmlhelp/commview/logformat.htm
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <glib.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include "wtap.h"
#include "wtap-int.h"
#include "buffer.h"
#include "file_wrappers.h"
#include "commview.h"
typedef struct commview_header {
guint16 data_len;
guint16 source_data_len;
guint8 version;
guint16 year;
guint8 month;
guint8 day;
guint8 hours;
guint8 minutes;
guint8 seconds;
guint32 usecs;
guint8 flags; /* Bit-field positions defined below */
guint8 signal_level_percent;
guint8 rate;
guint8 band;
guint8 channel;
guint8 direction; /* Or for WiFi, high order byte of
* packet rate. */
guint8 signal_level_dbm;
guint8 noise_level; /* In dBm (WiFi only) */
} commview_header_t;
#define COMMVIEW_HEADER_SIZE 24
/* Bit-field positions for various fields in the flags variable of the header */
#define FLAGS_MEDIUM 0x0F
#define FLAGS_DECRYPTED 0x10
#define FLAGS_BROKEN 0x20
#define FLAGS_COMPRESSED 0x40
#define FLAGS_RESERVED 0x80
/* Capture mediums as defined by the commview file format */
#define MEDIUM_ETHERNET 0
#define MEDIUM_WIFI 1
#define MEDIUM_TOKEN_RING 2
static gboolean commview_read(wtap *wth, int *err, gchar **err_info,
gint64 *data_offset);
static gboolean commview_seek_read(wtap *wth, gint64 seek_off,
union wtap_pseudo_header *pseudo_header,
guint8 *pd, int length, int *err,
gchar **err_info);
static gboolean commview_read_header(commview_header_t *cv_hdr, FILE_T fh,
int *err, gchar **err_info);
static gboolean commview_dump(wtap_dumper *wdh, const struct wtap_pkthdr *phdr,
const union wtap_pseudo_header *pseudo_header,
const guint8 *pd, int *err);
int commview_open(wtap *wth, int *err, gchar **err_info)
{
commview_header_t cv_hdr;
if(!commview_read_header(&cv_hdr, wth->fh, err, err_info))
return -1;
/* If any of these fields do not match what we expect, bail out. */
if(cv_hdr.version != 0 ||
cv_hdr.year < 1970 || cv_hdr.year >= 2038 ||
cv_hdr.month < 1 || cv_hdr.month > 12 ||
cv_hdr.day < 1 || cv_hdr.day > 31 ||
cv_hdr.hours > 23 ||
cv_hdr.minutes > 59 ||
cv_hdr.seconds > 60 ||
cv_hdr.signal_level_percent > 100 ||
(cv_hdr.flags & FLAGS_RESERVED) != 0 ||
((cv_hdr.flags & FLAGS_MEDIUM) != MEDIUM_ETHERNET &&
(cv_hdr.flags & FLAGS_MEDIUM) != MEDIUM_WIFI &&
(cv_hdr.flags & FLAGS_MEDIUM) != MEDIUM_TOKEN_RING))
return 0; /* Not our kind of file */
/* No file header. Reset the fh to 0 so we can read the first packet */
if (file_seek(wth->fh, 0, SEEK_SET, err) == -1)
return -1;
/* Set up the pointers to the handlers for this file type */
wth->subtype_read = commview_read;
wth->subtype_seek_read = commview_seek_read;
wth->data_offset = 0;
wth->file_type = WTAP_FILE_COMMVIEW;
wth->file_encap = WTAP_ENCAP_PER_PACKET;
wth->tsprecision = WTAP_FILE_TSPREC_USEC;
return 1; /* Our kind of file */
}
static void
commview_set_pseudo_header(commview_header_t *cv_hdrp, union wtap_pseudo_header
*pseudo_header)
{
switch(cv_hdrp->flags & FLAGS_MEDIUM) {
case MEDIUM_ETHERNET :
pseudo_header->eth.fcs_len = -1; /* Unknown */
break;
case MEDIUM_WIFI :
pseudo_header->ieee_802_11.fcs_len = -1; /* Unknown */
pseudo_header->ieee_802_11.channel = cv_hdrp->channel;
pseudo_header->ieee_802_11.data_rate = cv_hdrp->rate;
pseudo_header->ieee_802_11.signal_level = cv_hdrp->signal_level_percent;
break;
default :
/* Token Ring or unknown - no pseudo-header for that */
break;
}
}
static gboolean
commview_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset)
{
commview_header_t cv_hdr;
struct tm tm;
int bytes_read;
*data_offset = wth->data_offset;
if(!commview_read_header(&cv_hdr, wth->fh, err, err_info))
return FALSE;
wth->data_offset += COMMVIEW_HEADER_SIZE;
switch(cv_hdr.flags & FLAGS_MEDIUM) {
case MEDIUM_ETHERNET :
wth->phdr.pkt_encap = WTAP_ENCAP_ETHERNET;
break;
case MEDIUM_WIFI :
wth->phdr.pkt_encap = WTAP_ENCAP_IEEE_802_11_WITH_RADIO;
break;
case MEDIUM_TOKEN_RING :
wth->phdr.pkt_encap = WTAP_ENCAP_TOKEN_RING;
break;
default :
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup_printf("commview: unsupported encap: %u",
cv_hdr.flags & FLAGS_MEDIUM);
return FALSE;
}
commview_set_pseudo_header(&cv_hdr, &wth->pseudo_header);
buffer_assure_space(wth->frame_buffer, cv_hdr.data_len);
bytes_read = file_read(buffer_start_ptr(wth->frame_buffer),
cv_hdr.data_len, wth->fh);
if(bytes_read != cv_hdr.data_len) {
*err = file_error(wth->fh, err_info);
if(*err == 0)
*err = WTAP_ERR_SHORT_READ;
return FALSE;
}
tm.tm_year = cv_hdr.year - 1900;
tm.tm_mon = cv_hdr.month - 1;
tm.tm_mday = cv_hdr.day;
tm.tm_hour = cv_hdr.hours;
tm.tm_min = cv_hdr.minutes;
tm.tm_sec = cv_hdr.seconds;
tm.tm_isdst = -1;
wth->data_offset += cv_hdr.data_len;
wth->phdr.presence_flags = WTAP_HAS_TS;
wth->phdr.len = cv_hdr.data_len;
wth->phdr.caplen = cv_hdr.data_len;
wth->phdr.ts.secs = mktime(&tm);
wth->phdr.ts.nsecs = cv_hdr.usecs * 1000;
return TRUE;
}
static gboolean
commview_seek_read(wtap *wth, gint64 seek_off, union wtap_pseudo_header
*pseudo_header, guint8 *pd, int length, int *err,
gchar **err_info)
{
commview_header_t cv_hdr;
int bytes_read;
if(file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
return FALSE;
if(!commview_read_header(&cv_hdr, wth->random_fh, err, err_info)) {
if(*err == 0)
*err = WTAP_ERR_SHORT_READ;
return FALSE;
}
if(length != cv_hdr.data_len) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup_printf("commview: record length %u doesn't match requested length %d", cv_hdr.data_len, length);
return FALSE;
}
commview_set_pseudo_header(&cv_hdr, pseudo_header);
bytes_read = file_read(pd, cv_hdr.data_len, wth->random_fh);
if(bytes_read != cv_hdr.data_len) {
*err = file_error(wth->random_fh, err_info);
if(*err == 0)
*err = WTAP_ERR_SHORT_READ;
return FALSE;
}
return TRUE;
}
static gboolean
commview_read_header(commview_header_t *cv_hdr, FILE_T fh, int *err,
gchar **err_info)
{
wtap_file_read_expected_bytes(&cv_hdr->data_len, 2, fh, err, err_info);
wtap_file_read_expected_bytes(&cv_hdr->source_data_len, 2, fh, err, err_info);
wtap_file_read_expected_bytes(&cv_hdr->version, 1, fh, err, err_info);
wtap_file_read_expected_bytes(&cv_hdr->year, 2, fh, err, err_info);
wtap_file_read_expected_bytes(&cv_hdr->month, 1, fh, err, err_info);
wtap_file_read_expected_bytes(&cv_hdr->day, 1, fh, err, err_info);
wtap_file_read_expected_bytes(&cv_hdr->hours, 1, fh, err, err_info);
wtap_file_read_expected_bytes(&cv_hdr->minutes, 1, fh, err, err_info);
wtap_file_read_expected_bytes(&cv_hdr->seconds, 1, fh, err, err_info);
wtap_file_read_expected_bytes(&cv_hdr->usecs, 4, fh, err, err_info);
wtap_file_read_expected_bytes(&cv_hdr->flags, 1, fh, err, err_info);
wtap_file_read_expected_bytes(&cv_hdr->signal_level_percent, 1, fh, err, err_info);
wtap_file_read_expected_bytes(&cv_hdr->rate, 1, fh, err, err_info);
wtap_file_read_expected_bytes(&cv_hdr->band, 1, fh, err, err_info);
wtap_file_read_expected_bytes(&cv_hdr->channel, 1, fh, err, err_info);
wtap_file_read_expected_bytes(&cv_hdr->direction, 1, fh, err, err_info);
wtap_file_read_expected_bytes(&cv_hdr->signal_level_dbm, 1, fh, err, err_info);
wtap_file_read_expected_bytes(&cv_hdr->noise_level, 1, fh, err, err_info);
/* Convert multi-byte values from little endian to host endian format */
cv_hdr->data_len = GUINT16_FROM_LE(cv_hdr->data_len);
cv_hdr->source_data_len = GUINT16_FROM_LE(cv_hdr->source_data_len);
cv_hdr->year = GUINT16_FROM_LE(cv_hdr->year);
cv_hdr->usecs = GUINT32_FROM_LE(cv_hdr->usecs);
return TRUE;
}
/* Returns 0 if we can write out the specified encapsulation type
* into a CommView format file. */
int commview_dump_can_write_encap(int encap)
{
switch (encap) {
case WTAP_ENCAP_ETHERNET :
case WTAP_ENCAP_IEEE_802_11 :
case WTAP_ENCAP_IEEE_802_11_WITH_RADIO :
case WTAP_ENCAP_TOKEN_RING :
case WTAP_ENCAP_PER_PACKET :
return 0;
default:
return WTAP_ERR_UNSUPPORTED_ENCAP;
}
}
/* Returns TRUE on success, FALSE on failure;
sets "*err" to an error code on failure */
gboolean commview_dump_open(wtap_dumper *wdh, int *err _U_)
{
wdh->subtype_write = commview_dump;
wdh->subtype_close = NULL;
/* There is no file header to write out */
wdh->bytes_dumped = 0;
return TRUE;
}
/* Write a record for a packet to a dump file.
* Returns TRUE on success, FALSE on failure. */
static gboolean commview_dump(wtap_dumper *wdh,
const struct wtap_pkthdr *phdr,
const union wtap_pseudo_header *pseudo_header,
const guint8 *pd, int *err)
{
commview_header_t cv_hdr;
struct tm *tm;
memset(&cv_hdr, 0, sizeof(cv_hdr));
cv_hdr.data_len = GUINT16_TO_LE((guint16)phdr->caplen);
cv_hdr.source_data_len = GUINT16_TO_LE((guint16)phdr->caplen);
cv_hdr.version = 0;
tm = localtime(&phdr->ts.secs);
cv_hdr.year = tm->tm_year + 1900;
cv_hdr.month = tm->tm_mon + 1;
cv_hdr.day = tm->tm_mday;
cv_hdr.hours = tm->tm_hour;
cv_hdr.minutes = tm->tm_min;
cv_hdr.seconds = tm->tm_sec;
cv_hdr.usecs = GUINT32_TO_LE(phdr->ts.nsecs / 1000);
switch(phdr->pkt_encap) {
case WTAP_ENCAP_ETHERNET :
cv_hdr.flags |= MEDIUM_ETHERNET;
break;
case WTAP_ENCAP_IEEE_802_11 :
cv_hdr.flags |= MEDIUM_WIFI;
break;
case WTAP_ENCAP_IEEE_802_11_WITH_RADIO :
cv_hdr.flags |= MEDIUM_WIFI;
cv_hdr.channel = pseudo_header->ieee_802_11.channel;
cv_hdr.rate = pseudo_header->ieee_802_11.data_rate;
cv_hdr.signal_level_percent = pseudo_header->ieee_802_11.signal_level;
break;
case WTAP_ENCAP_TOKEN_RING :
cv_hdr.flags |= MEDIUM_TOKEN_RING;
break;
default :
*err = WTAP_ERR_UNSUPPORTED_ENCAP;
return FALSE;
}
if (!wtap_dump_file_write(wdh, &cv_hdr.data_len, 2, err))
return FALSE;
if (!wtap_dump_file_write(wdh, &cv_hdr.source_data_len, 2, err))
return FALSE;
if (!wtap_dump_file_write(wdh, &cv_hdr.version, 1, err))
return FALSE;
if (!wtap_dump_file_write(wdh, &cv_hdr.year, 2, err))
return FALSE;
if (!wtap_dump_file_write(wdh, &cv_hdr.month, 1, err))
return FALSE;
if (!wtap_dump_file_write(wdh, &cv_hdr.day, 1, err))
return FALSE;
if (!wtap_dump_file_write(wdh, &cv_hdr.hours, 1, err))
return FALSE;
if (!wtap_dump_file_write(wdh, &cv_hdr.minutes, 1, err))
return FALSE;
if (!wtap_dump_file_write(wdh, &cv_hdr.seconds, 1, err))
return FALSE;
if (!wtap_dump_file_write(wdh, &cv_hdr.usecs, 4, err))
return FALSE;
if (!wtap_dump_file_write(wdh, &cv_hdr.flags, 1, err))
return FALSE;
if (!wtap_dump_file_write(wdh, &cv_hdr.signal_level_percent, 1, err))
return FALSE;
if (!wtap_dump_file_write(wdh, &cv_hdr.rate, 1, err))
return FALSE;
if (!wtap_dump_file_write(wdh, &cv_hdr.band, 1, err))
return FALSE;
if (!wtap_dump_file_write(wdh, &cv_hdr.channel, 1, err))
return FALSE;
if (!wtap_dump_file_write(wdh, &cv_hdr.direction, 1, err))
return FALSE;
if (!wtap_dump_file_write(wdh, &cv_hdr.signal_level_dbm, 2, err))
return FALSE;
if (!wtap_dump_file_write(wdh, &cv_hdr.noise_level, 2, err))
return FALSE;
wdh->bytes_dumped += COMMVIEW_HEADER_SIZE;
if (!wtap_dump_file_write(wdh, pd, phdr->caplen, err))
return FALSE;
wdh->bytes_dumped += phdr->caplen;
return TRUE;
}
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