| /******************************************************************************* |
| * 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 "MQTTPacket.h" |
| #include "StackTrace.h" |
| |
| #include <string.h> |
| |
| /** |
| * Determines the length of the MQTT connect packet that would be produced using the supplied connect options. |
| * @param options the options to be used to build the connect packet |
| * @return the length of buffer needed to contain the serialized version of the packet |
| */ |
| int MQTTSerialize_connectLength(MQTTPacket_connectData* options) |
| { |
| int len = 0; |
| |
| FUNC_ENTRY; |
| |
| if (options->MQTTVersion == 3) |
| len = 12; /* variable depending on MQTT or MQIsdp */ |
| else if (options->MQTTVersion == 4) |
| len = 10; |
| |
| len += MQTTstrlen(options->clientID)+2; |
| if (options->willFlag) |
| len += MQTTstrlen(options->will.topicName)+2 + MQTTstrlen(options->will.message)+2; |
| if (options->username.cstring || options->username.lenstring.data) |
| len += MQTTstrlen(options->username)+2; |
| if (options->password.cstring || options->password.lenstring.data) |
| len += MQTTstrlen(options->password)+2; |
| |
| FUNC_EXIT_RC(len); |
| return len; |
| } |
| |
| |
| /** |
| * Serializes the connect options into the buffer. |
| * @param buf the buffer into which the packet will be serialized |
| * @param len the length in bytes of the supplied buffer |
| * @param options the options to be used to build the connect packet |
| * @return serialized length, or error if 0 |
| */ |
| int MQTTSerialize_connect(unsigned char* buf, int buflen, MQTTPacket_connectData* options) |
| { |
| unsigned char *ptr = buf; |
| MQTTHeader header = {0}; |
| MQTTConnectFlags flags = {0}; |
| int len = 0; |
| int rc = -1; |
| |
| FUNC_ENTRY; |
| if (MQTTPacket_len(len = MQTTSerialize_connectLength(options)) > buflen) |
| { |
| rc = MQTTPACKET_BUFFER_TOO_SHORT; |
| goto exit; |
| } |
| |
| header.byte = 0; |
| header.bits.type = CONNECT; |
| writeChar(&ptr, header.byte); /* write header */ |
| |
| ptr += MQTTPacket_encode(ptr, len); /* write remaining length */ |
| |
| if (options->MQTTVersion == 4) |
| { |
| writeCString(&ptr, "MQTT"); |
| writeChar(&ptr, (char) 4); |
| } |
| else |
| { |
| writeCString(&ptr, "MQIsdp"); |
| writeChar(&ptr, (char) 3); |
| } |
| |
| flags.all = 0; |
| flags.bits.cleansession = options->cleansession; |
| flags.bits.will = (options->willFlag) ? 1 : 0; |
| if (flags.bits.will) |
| { |
| flags.bits.willQoS = options->will.qos; |
| flags.bits.willRetain = options->will.retained; |
| } |
| |
| if (options->username.cstring || options->username.lenstring.data) |
| flags.bits.username = 1; |
| if (options->password.cstring || options->password.lenstring.data) |
| flags.bits.password = 1; |
| |
| writeChar(&ptr, flags.all); |
| writeInt(&ptr, options->keepAliveInterval); |
| writeMQTTString(&ptr, options->clientID); |
| if (options->willFlag) |
| { |
| writeMQTTString(&ptr, options->will.topicName); |
| writeMQTTString(&ptr, options->will.message); |
| } |
| if (flags.bits.username) |
| writeMQTTString(&ptr, options->username); |
| if (flags.bits.password) |
| writeMQTTString(&ptr, options->password); |
| |
| rc = ptr - buf; |
| |
| exit: FUNC_EXIT_RC(rc); |
| return rc; |
| } |
| |
| |
| /** |
| * Deserializes the supplied (wire) buffer into connack data - return code |
| * @param sessionPresent the session present flag returned (only for MQTT 3.1.1) |
| * @param connack_rc returned integer value of the connack return code |
| * @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_connack(unsigned char* sessionPresent, unsigned char* connack_rc, unsigned char* buf, int buflen) |
| { |
| MQTTHeader header = {0}; |
| unsigned char* curdata = buf; |
| unsigned char* enddata = NULL; |
| int rc = 0; |
| int mylen; |
| MQTTConnackFlags flags = {0}; |
| |
| FUNC_ENTRY; |
| header.byte = readChar(&curdata); |
| if (header.bits.type != CONNACK) |
| goto exit; |
| |
| curdata += (rc = MQTTPacket_decodeBuf(curdata, &mylen)); /* read remaining length */ |
| enddata = curdata + mylen; |
| if (enddata - curdata < 2) |
| goto exit; |
| |
| flags.all = readChar(&curdata); |
| *sessionPresent = flags.bits.sessionpresent; |
| *connack_rc = readChar(&curdata); |
| |
| rc = 1; |
| exit: |
| FUNC_EXIT_RC(rc); |
| return rc; |
| } |
| |
| |
| /** |
| * Serializes a 0-length packet into the supplied buffer, ready for writing to a socket |
| * @param buf the buffer into which the packet will be serialized |
| * @param buflen the length in bytes of the supplied buffer, to avoid overruns |
| * @param packettype the message type |
| * @return serialized length, or error if 0 |
| */ |
| int MQTTSerialize_zero(unsigned char* buf, int buflen, unsigned char packettype) |
| { |
| MQTTHeader header = {0}; |
| int rc = -1; |
| unsigned char *ptr = buf; |
| |
| FUNC_ENTRY; |
| if (buflen < 2) |
| { |
| rc = MQTTPACKET_BUFFER_TOO_SHORT; |
| goto exit; |
| } |
| header.byte = 0; |
| header.bits.type = packettype; |
| writeChar(&ptr, header.byte); /* write header */ |
| |
| ptr += MQTTPacket_encode(ptr, 0); /* write remaining length */ |
| rc = ptr - buf; |
| exit: |
| FUNC_EXIT_RC(rc); |
| return rc; |
| } |
| |
| |
| /** |
| * Serializes a disconnect packet into the supplied buffer, ready for writing to a socket |
| * @param buf the buffer into which the packet will be serialized |
| * @param buflen the length in bytes of the supplied buffer, to avoid overruns |
| * @return serialized length, or error if 0 |
| */ |
| int MQTTSerialize_disconnect(unsigned char* buf, int buflen) |
| { |
| return MQTTSerialize_zero(buf, buflen, DISCONNECT); |
| } |
| |
| |
| /** |
| * Serializes a disconnect packet into the supplied buffer, ready for writing to a socket |
| * @param buf the buffer into which the packet will be serialized |
| * @param buflen the length in bytes of the supplied buffer, to avoid overruns |
| * @return serialized length, or error if 0 |
| */ |
| int MQTTSerialize_pingreq(unsigned char* buf, int buflen) |
| { |
| return MQTTSerialize_zero(buf, buflen, PINGREQ); |
| } |