| /******************************************************************************* |
| * Copyright (c) 2014 IBM Corp. |
| * |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * and Eclipse Distribution License v1.0 which accompany this distribution. |
| * |
| * The Eclipse Public License is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * and the Eclipse Distribution License is available at |
| * http://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * Contributors: |
| * Ian Craggs - initial API and implementation and/or initial documentation |
| *******************************************************************************/ |
| |
| #include "StackTrace.h" |
| #include "MQTTPacket.h" |
| #include <string.h> |
| |
| #define min(a, b) ((a < b) ? a : b) |
| |
| |
| /** |
| * Validates MQTT protocol name and version combinations |
| * @param protocol the MQTT protocol name as an MQTTString |
| * @param version the MQTT protocol version number, as in the connect packet |
| * @return correct MQTT combination? 1 is true, 0 is false |
| */ |
| int MQTTPacket_checkVersion(MQTTString* protocol, int version) |
| { |
| int rc = 0; |
| |
| if (version == 3 && memcmp(protocol->lenstring.data, "MQIsdp", |
| min(6, protocol->lenstring.len)) == 0) |
| rc = 1; |
| else if (version == 4 && memcmp(protocol->lenstring.data, "MQTT", |
| min(4, protocol->lenstring.len)) == 0) |
| rc = 1; |
| return rc; |
| } |
| |
| |
| /** |
| * Deserializes the supplied (wire) buffer into connect data structure |
| * @param data the connect data structure to be filled out |
| * @param buf the raw buffer data, of the correct length determined by the remaining length field |
| * @param len the length in bytes of the data in the supplied buffer |
| * @return error code. 1 is success, 0 is failure |
| */ |
| int MQTTDeserialize_connect(MQTTPacket_connectData* data, unsigned char* buf, int len) |
| { |
| MQTTHeader header = {0}; |
| MQTTConnectFlags flags = {0}; |
| unsigned char* curdata = buf; |
| unsigned char* enddata = &buf[len]; |
| int rc = 0; |
| MQTTString Protocol; |
| int version; |
| int mylen = 0; |
| |
| FUNC_ENTRY; |
| header.byte = readChar(&curdata); |
| if (header.bits.type != CONNECT) |
| goto exit; |
| |
| curdata += MQTTPacket_decodeBuf(curdata, &mylen); /* read remaining length */ |
| |
| if (!readMQTTLenString(&Protocol, &curdata, enddata) || |
| enddata - curdata < 0) /* do we have enough data to read the protocol version byte? */ |
| goto exit; |
| |
| version = (int)readChar(&curdata); /* Protocol version */ |
| /* If we don't recognize the protocol version, we don't parse the connect packet on the |
| * basis that we don't know what the format will be. |
| */ |
| if (MQTTPacket_checkVersion(&Protocol, version)) |
| { |
| flags.all = readChar(&curdata); |
| data->cleansession = flags.bits.cleansession; |
| data->keepAliveInterval = readInt(&curdata); |
| if (!readMQTTLenString(&data->clientID, &curdata, enddata)) |
| goto exit; |
| data->willFlag = flags.bits.will; |
| if (flags.bits.will) |
| { |
| data->will.qos = flags.bits.willQoS; |
| data->will.retained = flags.bits.willRetain; |
| if (!readMQTTLenString(&data->will.topicName, &curdata, enddata) || |
| !readMQTTLenString(&data->will.message, &curdata, enddata)) |
| goto exit; |
| } |
| if (flags.bits.username) |
| { |
| if (enddata - curdata < 3 || !readMQTTLenString(&data->username, &curdata, enddata)) |
| goto exit; /* username flag set, but no username supplied - invalid */ |
| if (flags.bits.password && |
| (enddata - curdata < 3 || !readMQTTLenString(&data->password, &curdata, enddata))) |
| goto exit; /* password flag set, but no password supplied - invalid */ |
| } |
| else if (flags.bits.password) |
| goto exit; /* password flag set without username - invalid */ |
| rc = 1; |
| } |
| exit: |
| FUNC_EXIT_RC(rc); |
| return rc; |
| } |
| |
| |
| /** |
| * Serializes the connack packet into the supplied buffer. |
| * @param buf the buffer into which the packet will be serialized |
| * @param buflen the length in bytes of the supplied buffer |
| * @param connack_rc the integer connack return code to be used |
| * @param sessionPresent the MQTT 3.1.1 sessionPresent flag |
| * @return serialized length, or error if 0 |
| */ |
| int MQTTSerialize_connack(unsigned char* buf, int buflen, unsigned char connack_rc, unsigned char sessionPresent) |
| { |
| MQTTHeader header = {0}; |
| int rc = 0; |
| unsigned char *ptr = buf; |
| MQTTConnackFlags flags = {0}; |
| |
| FUNC_ENTRY; |
| if (buflen < 2) |
| { |
| rc = MQTTPACKET_BUFFER_TOO_SHORT; |
| goto exit; |
| } |
| header.byte = 0; |
| header.bits.type = CONNACK; |
| writeChar(&ptr, header.byte); /* write header */ |
| |
| ptr += MQTTPacket_encode(ptr, 2); /* write remaining length */ |
| |
| flags.all = 0; |
| flags.bits.sessionpresent = sessionPresent; |
| writeChar(&ptr, flags.all); |
| writeChar(&ptr, connack_rc); |
| |
| rc = ptr - buf; |
| exit: |
| FUNC_EXIT_RC(rc); |
| return rc; |
| } |
| |