col_set_str(pinfo->cinfo, COL_PROTOCOL, "WSMP");
col_set_str(pinfo->cinfo, COL_INFO, "WAVE Short Message Protocol IEEE P1609.3");
/* create display subtree for the protocol */
ti = proto_tree_add_item(tree, proto_wsmp, tvb, 0, -1, ENC_NA);
wsmp_tree = proto_item_add_subtree(ti, ett_wsmp);
offset = 0;
proto_tree_add_item(wsmp_tree,
hf_wsmp_version, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
psid = tvb_get_guint8(tvb, offset);
psidLen = (guint32)wme_getpsidlen((guint8*)&psid);
if (psidLen == 2)
psid = tvb_get_ntohs(tvb, offset);
else if (psidLen == 3)
psid = tvb_get_ntoh24(tvb, offset);
else if (psidLen == 4)
psid = tvb_get_ntohl(tvb, offset);
proto_tree_add_item(wsmp_tree,
hf_wsmp_psid, tvb, offset, psidLen, ENC_BIG_ENDIAN);
offset += psidLen;
/* TLV decoder that does not display the T and L elements */
static void
dissect_wsmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
/* Set up structures needed to add the protocol subtree and manage it */
proto_item *ti, *wsmdata_item;
proto_tree *wsmp_tree, *wsmdata_tree;
tvbuff_t *wsmdata_tvb;
guint16 wsmlength, offset;
guint32 psidLen, psid;
guint8 elemenId, elemenLen, msb, supLen;
/* Make entries in Protocol column and Info column on summary display */
col_set_str(pinfo->cinfo, COL_PROTOCOL, "WSMP");
col_set_str(pinfo->cinfo, COL_INFO, "WAVE Short Message Protocol IEEE P1609.3");
/* create display subtree for the protocol */
ti = proto_tree_add_item(tree, proto_wsmp, tvb, 0, -1, ENC_NA);
wsmp_tree = proto_item_add_subtree(ti, ett_wsmp);
offset = 0;
proto_tree_add_item(wsmp_tree,
hf_wsmp_version, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
psid = tvb_get_guint8(tvb, offset);
psidLen = (guint32)wme_getpsidlen((guint8*)&psid);
if (psidLen == 2)
psid = tvb_get_ntohs(tvb, offset);
else if (psidLen == 3)
{
psid = tvb_get_ntohl(tvb, offset);
psid = psid & 0x00FFFF; /* three bytes */
}
else if (psidLen == 4)
psid = tvb_get_ntohl(tvb, offset);
proto_tree_add_item(wsmp_tree,
hf_wsmp_psid, tvb, offset, psidLen, ENC_BIG_ENDIAN);
offset += psidLen;
elemenId = tvb_get_guint8(tvb, offset);
while ((elemenId != WSMP) && (elemenId != WSMP_S) && (elemenId != WSMP_I))
{
offset++;
if (elemenId == CHANNUM)
{
/* channel number */
elemenLen = tvb_get_guint8(tvb, offset);
offset++;
proto_tree_add_item(wsmp_tree,
hf_wsmp_channel, tvb, offset, elemenLen, ENC_BIG_ENDIAN);
offset += elemenLen;
}
else if (elemenId == DATARATE)
{
/* Data rate */
elemenLen = tvb_get_guint8(tvb, offset);
offset++;
proto_tree_add_item(wsmp_tree,
hf_wsmp_rate, tvb, offset, elemenLen, ENC_BIG_ENDIAN);
offset += elemenLen;
}
else if (elemenId == TRANSMITPW)
{
/* Transmit power */
elemenLen = tvb_get_guint8(tvb, offset);
offset++;
proto_tree_add_item(wsmp_tree,
hf_wsmp_txpower, tvb, offset, elemenLen, ENC_BIG_ENDIAN);
offset += elemenLen;
}
elemenId = tvb_get_guint8(tvb, offset);
}
proto_tree_add_item(wsmp_tree,
hf_wsmp_WAVEid, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
wsmlength = tvb_get_letohs( tvb, offset);
proto_tree_add_item(wsmp_tree,
hf_wsmp_wsmlength, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
if (elemenId == WSMP_S)
{
msb = 1;
supLen = 0;
while (msb)
{
msb = tvb_get_guint8(tvb, offset + supLen);
msb = msb & 0x80;
supLen++;
}
proto_tree_add_item(wsmp_tree,
hf_wsmp_WSMP_S_data, tvb, offset, supLen, ENC_BIG_ENDIAN);
wsmlength -= supLen;
offset += supLen;
}
wsmdata_item = proto_tree_add_text (wsmp_tree, tvb, offset, wsmlength,
"Wave Short Message");
wsmdata_tree = proto_item_add_subtree(wsmdata_item, ett_wsmdata);
wsmdata_tvb = tvb_new_subset(tvb, offset, -1, wsmlength);
/* TODO: Branch on the application context and display accordingly
* Default: call the data dissector
*/
if (psid == 0xbff0)
{
call_dissector(data_handle, wsmdata_tvb, pinfo, wsmdata_tree);
}
}
