nexmon – Rev 1
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/* stanag4607.c
*
* STANAG 4607 file reading
*
* http://www.nato.int/structur/AC/224/standard/4607/4607e_JAS_ED3.pdf
*
* 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.
*/
#include "config.h"
#include <errno.h>
#include "wtap-int.h"
#include "file_wrappers.h"
#include <wsutil/buffer.h>
#include "stanag4607.h"
typedef struct {
time_t base_secs;
} stanag4607_t;
static gboolean is_valid_id(guint16 version_id)
{
#define VERSION_21 0x3231
#define VERSION_30 0x3330
if ((version_id != VERSION_21) &&
(version_id != VERSION_30))
/* Not a stanag4607 file */
return FALSE;
return TRUE;
}
static gboolean stanag4607_read_file(wtap *wth, FILE_T fh, struct wtap_pkthdr *phdr,
Buffer *buf, int *err, gchar **err_info)
{
stanag4607_t *stanag4607 = (stanag4607_t *)wth->priv;
guint32 millisecs, secs, nsecs;
gint64 offset = 0;
guint8 stanag_pkt_hdr[37];
guint32 packet_size;
*err = 0;
/* Combined packet header and segment header */
if (!wtap_read_bytes_or_eof(fh, stanag_pkt_hdr, sizeof stanag_pkt_hdr, err, err_info))
return FALSE;
offset += sizeof stanag_pkt_hdr;
if (!is_valid_id(pntoh16(&stanag_pkt_hdr[0]))) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup("Bad version number");
return FALSE;
}
phdr->rec_type = REC_TYPE_PACKET;
/* The next 4 bytes are the packet length */
packet_size = pntoh32(&stanag_pkt_hdr[2]);
if (packet_size > WTAP_MAX_PACKET_SIZE) {
/*
* Probably a corrupt capture file; don't blow up trying
* to allocate space for an immensely-large packet.
*/
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup_printf("stanag4607: File has %" G_GUINT32_FORMAT "d-byte packet, "
"bigger than maximum of %u", packet_size, WTAP_MAX_PACKET_SIZE);
return FALSE;
}
phdr->caplen = packet_size;
phdr->len = packet_size;
/* Sadly, the header doesn't contain times; but some segments do */
/* So, get the segment header, which is just past the 32-byte header. */
phdr->presence_flags = WTAP_HAS_TS;
/* If no time specified, it's the last baseline time */
phdr->ts.secs = stanag4607->base_secs;
phdr->ts.nsecs = 0;
millisecs = 0;
#define MISSION_SEGMENT 1
#define DWELL_SEGMENT 2
#define JOB_DEFINITION_SEGMENT 5
#define PLATFORM_LOCATION_SEGMENT 13
if (MISSION_SEGMENT == stanag_pkt_hdr[32]) {
guint8 mseg[39];
struct tm tm;
if (!wtap_read_bytes(fh, &mseg, sizeof mseg, err, err_info))
return FALSE;
offset += sizeof mseg;
tm.tm_year = pntoh16(&mseg[35]) - 1900;
tm.tm_mon = mseg[37] - 1;
tm.tm_mday = mseg[38];
tm.tm_hour = 0;
tm.tm_min = 0;
tm.tm_sec = 0;
tm.tm_isdst = -1;
stanag4607->base_secs = mktime(&tm);
phdr->ts.secs = stanag4607->base_secs;
}
else if (PLATFORM_LOCATION_SEGMENT == stanag_pkt_hdr[32]) {
if (!wtap_read_bytes(fh, &millisecs, sizeof millisecs, err, err_info))
return FALSE;
offset += sizeof millisecs;
millisecs = g_ntohl(millisecs);
}
else if (DWELL_SEGMENT == stanag_pkt_hdr[32]) {
guint8 dseg[19];
if (!wtap_read_bytes(fh, &dseg, sizeof dseg, err, err_info))
return FALSE;
offset += sizeof dseg;
millisecs = pntoh32(&dseg[15]);
}
if (0 != millisecs) {
secs = millisecs/1000;
nsecs = (millisecs - 1000 * secs) * 1000000;
phdr->ts.secs = stanag4607->base_secs + secs;
phdr->ts.nsecs = nsecs;
}
/* wind back to the start of the packet ... */
if (file_seek(fh, - offset, SEEK_CUR, err) == -1)
return FALSE;
return wtap_read_packet_bytes(fh, buf, packet_size, err, err_info);
}
static gboolean stanag4607_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset)
{
gint64 offset;
*err = 0;
offset = file_tell(wth->fh);
*data_offset = offset;
return stanag4607_read_file(wth, wth->fh, &wth->phdr, wth->frame_buffer, err, err_info);
}
static gboolean stanag4607_seek_read(wtap *wth, gint64 seek_off,
struct wtap_pkthdr *phdr,
Buffer *buf, int *err, gchar **err_info)
{
if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
return FALSE;
return stanag4607_read_file(wth, wth->random_fh, phdr, buf, err, err_info);
}
wtap_open_return_val stanag4607_open(wtap *wth, int *err, gchar **err_info)
{
guint16 version_id;
stanag4607_t *stanag4607;
if (!wtap_read_bytes(wth->fh, &version_id, sizeof version_id, err, err_info))
return (*err != WTAP_ERR_SHORT_READ) ? WTAP_OPEN_ERROR : WTAP_OPEN_NOT_MINE;
if (!is_valid_id(GUINT16_TO_BE(version_id)))
/* Not a stanag4607 file */
return WTAP_OPEN_NOT_MINE;
/* seek back to the start of the file */
if (file_seek(wth->fh, 0, SEEK_SET, err) == -1)
return WTAP_OPEN_ERROR;
wth->file_type_subtype = WTAP_FILE_TYPE_SUBTYPE_STANAG_4607;
wth->file_encap = WTAP_ENCAP_STANAG_4607;
wth->snapshot_length = 0; /* not known */
stanag4607 = (stanag4607_t *)g_malloc(sizeof(stanag4607_t));
wth->priv = (void *)stanag4607;
stanag4607->base_secs = 0; /* unknown as of yet */
wth->subtype_read = stanag4607_read;
wth->subtype_seek_read = stanag4607_seek_read;
wth->file_tsprec = WTAP_TSPREC_MSEC;
return WTAP_OPEN_MINE;
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local Variables:
* c-basic-offset: 2
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=2 tabstop=8 expandtab:
* :indentSize=2:tabSize=8:noTabs=true:
*/