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wireshark/wiretap/dct3trace.c

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/* dct3trace.c
* Routines for reading signalling traces generated by Gammu (www.gammu.org)
* from Nokia DCT3 phones in Netmonitor mode.
*
* gammu --nokiadebug nhm5_587.txt v18-19
*
* Duncan Salerno <duncan.salerno@googlemail.com>
*
* Wiretap Library
* Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "config.h"
#include "wtap-int.h"
#include "dct3trace.h"
#include "file_wrappers.h"
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <wsutil/strtoi.h>
/*
Example downlink data:
<?xml version="1.0"?>
<dump>
<l1 direction="down" logicalchannel="96" physicalchannel="19" sequence="268116" error="0" timeshift="2992" bsic="22" data="31063F100DD0297A53E1020103C802398E0B2B2B2B2B2B" >
<l2 data="063F100DD0297A53E1020103" rest="C802398E0B2B2B2B2B2B" >
</l2>
</l1>
</dump>
Example uplink data (no raw L1):
<?xml version="1.0"?>
<dump>
<l1 direction="up" logicalchannel="112" >
<l2 type="U" subtype="Unknown" p="0" data="061500400000000000000000000000000000" >
</l2>
</l1>
</dump>
*/
/* Magic text to check */
static const char dct3trace_magic_line1[] = "<?xml version=\"1.0\"?>";
static const char dct3trace_magic_line2[] = "<dump>";
static const char dct3trace_magic_record_start[] = "<l1 ";
static const char dct3trace_magic_record_end[] = "</l1>";
static const char dct3trace_magic_l2_start[] = "<l2 ";
#if 0 /* Not used ?? */
static const char dct3trace_magic_l2_end[] = "</l2>";
#endif
static const char dct3trace_magic_end[] = "</dump>";
#define MAX_PACKET_LEN 23
static gboolean dct3trace_read(wtap *wth, wtap_rec *rec,
Buffer *buf, int *err, gchar **err_info, gint64 *data_offset);
static gboolean dct3trace_seek_read(wtap *wth, gint64 seek_off,
wtap_rec *rec, Buffer *buf, int *err, gchar **err_info);
static int dct3trace_file_type_subtype = -1;
void register_dct3trace(void);
/*
* Following 3 functions taken from gsmdecode-0.7bis, with permission:
*
* https://web.archive.org/web/20091218112927/http://wiki.thc.org/gsm
*/
static int
hc2b(unsigned char hex)
{
hex = g_ascii_tolower(hex);
if ((hex >= '0') && (hex <= '9'))
return hex - '0';
if ((hex >= 'a') && (hex <= 'f'))
return hex - 'a' + 10;
return -1;
}
static int
hex2bin(guint8 *out, guint8 *out_end, char *in)
{
guint8 *out_start = out;
int is_low = 0;
int c;
while (*in != '\0')
{
c = hc2b(*(unsigned char *)in);
if (c < 0)
{
in++;
continue;
}
if (out == out_end)
{
/* Too much data */
return -1;
}
if (is_low == 0)
{
*out = c << 4;
is_low = 1;
} else {
*out |= (c & 0x0f);
is_low = 0;
out++;
}
in++;
}
return (int)(out - out_start);
}
static gboolean
xml_get_int(int *val, const char *str, const char *pattern, int *err, gchar **err_info)
{
const char *ptr, *endptr;
char *start, *end;
char buf[32];
ptr = strstr(str, pattern);
if (ptr == NULL) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup_printf("dct3trace: %s not found", pattern);
return FALSE;
}
/*
* XXX - should we just skip past the pattern and check for ="?
*/
start = strchr(ptr, '"');
if (start == NULL) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup_printf("dct3trace: opening quote for %s not found", pattern);
return FALSE;
}
start++;
/*
* XXX - should we just use ws_strtoi32() and check whether
* the character following the number is a "?
*/
end = strchr(start, '"');
if (end == NULL) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup_printf("dct3trace: closing quote for %s not found", pattern);
return FALSE;
}
if (end - start > 31) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup_printf("dct3trace: %s value is too long", pattern);
return FALSE;
}
memcpy(buf, start, end - start);
buf[end - start] = '\0';
/*
* XXX - should we allow negative numbers in all cases? Or are
* there cases where the number is unsigned?
*/
if (!ws_strtoi32(buf, &endptr, val)) {
*err = WTAP_ERR_BAD_FILE;
if (errno == ERANGE) {
if (*val < 0)
*err_info = g_strdup_printf("dct3trace: %s value is too small, minimum is %d", pattern, *val);
else
*err_info = g_strdup_printf("dct3trace: %s value is too large, maximum is %d", pattern, *val);
} else
*err_info = g_strdup_printf("dct3trace: %s value \"%s\" not a number", pattern, buf);
return FALSE;
}
if (*endptr != '\0') {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup_printf("dct3trace: %s value \"%s\" not a number", pattern, buf);
return FALSE;
}
return TRUE;
}
wtap_open_return_val dct3trace_open(wtap *wth, int *err, gchar **err_info)
{
char line1[64], line2[64];
/* Look for Gammu DCT3 trace header */
if (file_gets(line1, sizeof(line1), wth->fh) == NULL ||
file_gets(line2, sizeof(line2), wth->fh) == NULL)
{
*err = file_error(wth->fh, err_info);
if (*err != 0 && *err != WTAP_ERR_SHORT_READ)
return WTAP_OPEN_ERROR;
return WTAP_OPEN_NOT_MINE;
}
/* Don't compare line endings */
if( strncmp(dct3trace_magic_line1, line1, strlen(dct3trace_magic_line1)) != 0 ||
strncmp(dct3trace_magic_line2, line2, strlen(dct3trace_magic_line2)) != 0)
{
return WTAP_OPEN_NOT_MINE;
}
wth->file_encap = WTAP_ENCAP_GSM_UM;
wth->file_type_subtype = dct3trace_file_type_subtype;
wth->snapshot_length = 0; /* not known */
wth->subtype_read = dct3trace_read;
wth->subtype_seek_read = dct3trace_seek_read;
wth->file_tsprec = WTAP_TSPREC_SEC;
/*
* Add an IDB; we don't know how many interfaces were
* involved, so we just say one interface, about which
* we only know the link-layer type, snapshot length,
* and time stamp resolution.
*/
wtap_add_generated_idb(wth);
return WTAP_OPEN_MINE;
}
static gboolean dct3trace_get_packet(FILE_T fh, wtap_rec *rec,
Buffer *buf, int *err, gchar **err_info)
{
char line[1024];
guint8 databuf[MAX_PACKET_LEN], *bufp;
gboolean have_data = FALSE;
int len = 0;
bufp = &databuf[0];
while (file_gets(line, sizeof(line), fh) != NULL)
{
if( memcmp(dct3trace_magic_end, line, strlen(dct3trace_magic_end)) == 0 )
{
/* Return on end of file </dump> */
*err = 0;
return FALSE;
}
else if( memcmp(dct3trace_magic_record_end, line, strlen(dct3trace_magic_record_end)) == 0 )
{
/* Return on end of record </l1> */
if( have_data )
{
/* We've got a full packet! */
rec->rec_type = REC_TYPE_PACKET;
rec->presence_flags = 0; /* no time stamp, no separate "on the wire" length */
rec->ts.secs = 0;
rec->ts.nsecs = 0;
rec->rec_header.packet_header.caplen = len;
rec->rec_header.packet_header.len = len;
*err = 0;
/* Make sure we have enough room for the packet */
ws_buffer_assure_space(buf, rec->rec_header.packet_header.caplen);
memcpy( ws_buffer_start_ptr(buf), databuf, rec->rec_header.packet_header.caplen );
return TRUE;
}
else
{
/* If not got any data return error */
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup("dct3trace: record without data");
return FALSE;
}
}
else if( memcmp(dct3trace_magic_record_start, line, strlen(dct3trace_magic_record_start)) == 0 )
{
/* Parse L1 header <l1 ...>*/
int channel, tmp;
char *ptr;
rec->rec_header.packet_header.pseudo_header.gsm_um.uplink = !strstr(line, "direction=\"down\"");
if (!xml_get_int(&channel, line, "logicalchannel", err, err_info))
return FALSE;
/* Parse downlink only fields */
if( !rec->rec_header.packet_header.pseudo_header.gsm_um.uplink )
{
if (!xml_get_int(&tmp, line, "physicalchannel", err, err_info))
return FALSE;
rec->rec_header.packet_header.pseudo_header.gsm_um.arfcn = tmp;
if (!xml_get_int(&tmp, line, "sequence", err, err_info))
return FALSE;
rec->rec_header.packet_header.pseudo_header.gsm_um.tdma_frame = tmp;
if (!xml_get_int(&tmp, line, "bsic", err, err_info))
return FALSE;
rec->rec_header.packet_header.pseudo_header.gsm_um.bsic = tmp;
if (!xml_get_int(&tmp, line, "error", err, err_info))
return FALSE;
rec->rec_header.packet_header.pseudo_header.gsm_um.error = tmp;
if (!xml_get_int(&tmp, line, "timeshift", err, err_info))
return FALSE;
rec->rec_header.packet_header.pseudo_header.gsm_um.timeshift = tmp;
}
switch( channel )
{
case 128: rec->rec_header.packet_header.pseudo_header.gsm_um.channel = GSM_UM_CHANNEL_SDCCH; break;
case 112: rec->rec_header.packet_header.pseudo_header.gsm_um.channel = GSM_UM_CHANNEL_SACCH; break;
case 176: rec->rec_header.packet_header.pseudo_header.gsm_um.channel = GSM_UM_CHANNEL_FACCH; break;
case 96: rec->rec_header.packet_header.pseudo_header.gsm_um.channel = GSM_UM_CHANNEL_CCCH; break;
case 80: rec->rec_header.packet_header.pseudo_header.gsm_um.channel = GSM_UM_CHANNEL_BCCH; break;
default: rec->rec_header.packet_header.pseudo_header.gsm_um.channel = GSM_UM_CHANNEL_UNKNOWN; break;
}
/* Read data (if have it) into databuf */
ptr = strstr(line, "data=\"");
if( ptr )
{
have_data = TRUE; /* If has data... */
len = hex2bin(bufp, &databuf[MAX_PACKET_LEN], ptr+6);
if (len == -1)
{
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup_printf("dct3trace: record length %d too long", rec->rec_header.packet_header.caplen);
return FALSE;
}
}
}
else if( !have_data && memcmp(dct3trace_magic_l2_start, line, strlen(dct3trace_magic_l2_start)) == 0 )
{
/* For uplink packets we might not get the raw L1, so have to recreate it from the L2 */
/* Parse L2 header if didn't get data from L1 <l2 ...> */
int data_len;
char *ptr = strstr(line, "data=\"");
if( !ptr )
{
continue;
}
have_data = TRUE;
/*
* We know we have no data already, so we know
* we have enough room for the header.
*/
if( rec->rec_header.packet_header.pseudo_header.gsm_um.channel == GSM_UM_CHANNEL_SACCH || rec->rec_header.packet_header.pseudo_header.gsm_um.channel == GSM_UM_CHANNEL_FACCH || rec->rec_header.packet_header.pseudo_header.gsm_um.channel == GSM_UM_CHANNEL_SDCCH )
{
/* Add LAPDm B header */
memset(bufp, 0x1, 2);
len = 3;
}
else
{
/* Add LAPDm Bbis header */
len = 1;
}
bufp += len;
data_len = hex2bin(bufp, &databuf[MAX_PACKET_LEN], ptr+6);
if (data_len == -1)
{
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup_printf("dct3trace: record length %d too long", rec->rec_header.packet_header.caplen);
return FALSE;
}
len += data_len;
/* Add LAPDm length byte */
*(bufp - 1) = data_len << 2 | 0x1;
}
}
*err = file_error(fh, err_info);
if (*err == 0)
{
*err = WTAP_ERR_SHORT_READ;
}
return FALSE;
}
/* Find the next packet and parse it; called from wtap_read(). */
static gboolean dct3trace_read(wtap *wth, wtap_rec *rec, Buffer *buf,
int *err, gchar **err_info, gint64 *data_offset)
{
*data_offset = file_tell(wth->fh);
return dct3trace_get_packet(wth->fh, rec, buf, err, err_info);
}
/* Used to read packets in random-access fashion */
static gboolean dct3trace_seek_read(wtap *wth, gint64 seek_off,
wtap_rec *rec, Buffer *buf, int *err, gchar **err_info)
{
if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
{
return FALSE;
}
return dct3trace_get_packet(wth->random_fh, rec, buf, err, err_info);
}
static const struct supported_block_type dct3trace_blocks_supported[] = {
/*
* We support packet blocks, with no comments or other options.
*/
{ WTAP_BLOCK_PACKET, MULTIPLE_BLOCKS_SUPPORTED, NO_OPTIONS_SUPPORTED }
};
static const struct file_type_subtype_info dct3trace_info = {
"Gammu DCT3 trace", "dct3trace", "xml", NULL,
FALSE, BLOCKS_SUPPORTED(dct3trace_blocks_supported),
NULL, NULL, NULL
};
void register_dct3trace(void)
{
dct3trace_file_type_subtype = wtap_register_file_type_subtype(&dct3trace_info);
/*
* Register name for backwards compatibility with the
* wtap_filetypes table in Lua.
*/
wtap_register_backwards_compatibility_lua_name("DCT3TRACE",
dct3trace_file_type_subtype);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 8
* tab-width: 8
* indent-tabs-mode: t
* End:
*
* vi: set shiftwidth=8 tabstop=8 noexpandtab:
* :indentSize=8:tabSize=8:noTabs=false:
*/
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