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/*
* mqtt.c
*
* Copyright (C) 2016 Sorin Zamfir <sorin.zamfir@yahoo.com>
*
* This file is part of nDPI, an open source deep packet inspection
* library based on the OpenDPI and PACE technology by ipoque GmbH
*
* nDPI is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* nDPI 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with nDPI. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "ndpi_protocols.h"
#ifdef NDPI_PROTOCOL_MQTT
/**
* The type of control messages in mqtt version 3.1.1
* see http://docs.oasis-open.org/mqtt/mqtt/v3.1.1
*/
enum MQTT_PACKET_TYPES {
CONNECT = 1,
CONNACK = 2,
PUBLISH = 3,
PUBACK = 4,
PUBREC = 5,
PUBREL = 6,
PUBCOMP = 7,
SUBSCRIBE = 8,
SUBACK = 9,
UNSUBSCRIBE = 10,
UNSUBACK = 11,
PINGREQ = 12,
PINGRESP = 13,
DISCONNECT = 14
};
/**
* Entry point when protocol is identified.
*/
static void ndpi_int_mqtt_add_connection (struct ndpi_detection_module_struct *ndpi_struct,
struct ndpi_flow_struct *flow)
{
ndpi_set_detected_protocol(ndpi_struct,flow,NDPI_PROTOCOL_MQTT,NDPI_PROTOCOL_UNKNOWN);
NDPI_LOG(NDPI_PROTOCOL_MQTT, ndpi_struct, NDPI_LOG_DEBUG, "Mqtt found.\n");
}
/**
* Dissector function that searches Mqtt headers
*/
void ndpi_search_mqtt (struct ndpi_detection_module_struct *ndpi_struct,
struct ndpi_flow_struct *flow)
{
NDPI_LOG(NDPI_PROTOCOL_MQTT, ndpi_struct, NDPI_LOG_DEBUG, "Mqtt search called...\n");
struct ndpi_packet_struct *packet = &flow->packet;
if (packet->detected_protocol_stack[0] != NDPI_PROTOCOL_UNKNOWN) {
return;
}
NDPI_LOG(NDPI_PROTOCOL_MQTT, ndpi_struct, NDPI_LOG_DEBUG, "Mqtt detection...\n");
// searching for request
NDPI_LOG(NDPI_PROTOCOL_MQTT, ndpi_struct, NDPI_LOG_DEBUG, "====>>>> Mqtt header: %04x%04x%04x%04x [len: %u]\n",
packet->payload[0], packet->payload[1], packet->payload[2], packet->payload[3], packet->payload_packet_len);
if (packet->payload_packet_len < 2) {
NDPI_LOG(NDPI_PROTOCOL_MQTT, ndpi_struct, NDPI_LOG_DEBUG, "Excluding Mqtt .. mandatory header not found!\n");
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_MQTT);
return;
}
// we first extract the packet type
u_int8_t pt = (u_int8_t) ((packet->payload[0] & 0xF0) >> 4);
if ((pt == 0) || (pt == 15)) {
NDPI_LOG(NDPI_PROTOCOL_MQTT, ndpi_struct, NDPI_LOG_DEBUG, "Excluding Mqtt .. invalid packet type!\n");
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_MQTT);
return;
}
u_int8_t flags = (u_int8_t) (packet->payload[0] & 0x0F);
if ((((pt == CONNECT) || (pt == CONNACK) || (pt == PUBACK) || (pt == PUBREC) || (pt == PUBCOMP) ||
(pt = SUBACK) || (pt == UNSUBACK) || (pt == PINGREQ) || (pt == PINGRESP) || (pt == DISCONNECT))) && (flags != 0))
{
NDPI_LOG(NDPI_PROTOCOL_MQTT, ndpi_struct, NDPI_LOG_DEBUG, "Excluding Mqtt invalid Packet-Flag combination\n");
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_MQTT);
return;
}
if (((pt == PUBREL) || (pt == SUBSCRIBE) || (pt == UNSUBSCRIBE)) && (flags != 2)) {
NDPI_LOG(NDPI_PROTOCOL_MQTT, ndpi_struct, NDPI_LOG_DEBUG, "Excluding Mqtt invalid Packet-Flag combination\n");
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_MQTT);
return;
}
if ((pt == PUBLISH) && ((flags & 0x06) == 6)) // QoS combination
{
NDPI_LOG(NDPI_PROTOCOL_MQTT, ndpi_struct, NDPI_LOG_DEBUG, "Excluding Mqtt invalid Packet-Flag combination\n");
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_MQTT);
return;
}
// we have reached this point without any serious errors
// switch (pt) {
// case CONNECT:
//
// break;
// default:
// break;
// }
NDPI_LOG(NDPI_PROTOCOL_MQTT, ndpi_struct, NDPI_LOG_DEBUG, "Excluding Mqtt ...\n");
NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_MQTT);
return;
}
/**
* Entry point for the ndpi library
*/
void init_mqtt_dissector (struct ndpi_detection_module_struct *ndpi_struct,
u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask)
{
NDPI_LOG(NDPI_PROTOCOL_MQTT, ndpi_struct, NDPI_LOG_DEBUG, "Mqtt dissector init...\n");
ndpi_set_bitmask_protocol_detection ("MQTT", ndpi_struct, detection_bitmask, *id,
NDPI_PROTOCOL_MQTT,
ndpi_search_mqtt,
NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_WITH_PAYLOAD,
SAVE_DETECTION_BITMASK_AS_UNKNOWN, ADD_TO_DETECTION_BITMASK);
*id +=1;
}
#endif // NDPI_PROTOCOL_MQTT
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