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OBD-II: Fixing Service/Mode 0x04 dissection 

The current code assumes that the Service 0x04 has at least 1 parameter
byte in the request and 1 parameter byte in the response, which is
wrong.
This commit is contained in:
Dr. Lars Völker 2023-01-12 17:09:03 +01:00 committed by AndersBroman
parent bf8f30eba4
commit ea0f20e993
1 changed files with 7 additions and 2 deletions
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9
epan/dissectors/packet-obd-ii.c
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@ -1288,7 +1288,7 @@ dissect_obdii_query(tvbuff_t *tvb, struct obdii_packet_info *oinfo, proto_tree *
pid_len = oinfo->data_bytes - 1;
if (pid_len == 0)
{
if (oinfo->mode != 0x07)
if (oinfo->mode != 0x04 && oinfo->mode != 0x07)
return 0;
pid = 0; /* Should never be required but set to satisfy petri-dish */
}
@ -1309,6 +1309,7 @@ dissect_obdii_query(tvbuff_t *tvb, struct obdii_packet_info *oinfo, proto_tree *
col_append_fstr(oinfo->pinfo->cinfo, COL_INFO, " Request[%.3x] %s - %s", oinfo->can_id, mode_str, pid_str);
break;
case 0x04:
case 0x07:
col_append_fstr(oinfo->pinfo->cinfo, COL_INFO, " Request[%.3x] %s", oinfo->can_id, mode_str);
break;
@ -1333,6 +1334,10 @@ dissect_obdii_response(tvbuff_t *tvb, struct obdii_packet_info *oinfo, proto_tre
{
col_append_fstr(oinfo->pinfo->cinfo, COL_INFO, "Response[%.3x] %s ", oinfo->can_id, val_to_str(oinfo->mode, obdii_mode_vals, "Unknown (%.2x)"));
if (oinfo->mode == 0x04 && oinfo->data_bytes == 0x01) {
return tvb_captured_length(tvb);
}
oinfo->value_bytes = oinfo->data_bytes - OBDII_VAL_OFF;
if (oinfo->value_bytes >= 1) oinfo->valueA = tvb_get_guint8(tvb, OBDII_VAL_OFF);
@ -1417,7 +1422,7 @@ dissect_obdii(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
if (id_is_response)
{
if (data_bytes < 2)
if (mode != 0x44 && data_bytes < 2)
return 0;
if (mode < 0x40)
return 0;