Diff: src/MQTTCommon/MQTTConnectClient.c

Revision:

0:09ef59d2d0f7

Child:

22:0dbabcc6e7b2

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/MQTTCommon/MQTTConnectClient.c	Fri Oct 07 17:21:45 2016 +0000
@@ -0,0 +1,206 @@
+/*******************************************************************************
+ * 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 <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;
+
+
+	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;
+
+	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;
+
+	if (MQTTPacket_len(len = MQTTSerialize_connectLength(options)) > buflen)
+	{
+		rc = MQTTPACKET_BUFFER_TOO_SHORT;
+		goto exit;
+	}
+
+	header.byte = 0;
+	header.bits.type = CONNECT_MSG;
+	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:
+	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};
+
+	header.byte = readChar(&curdata);
+	if (header.bits.type != CONNACK_MSG)
+		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:
+	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;
+
+	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:
+	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_MSG);
+}
+
+
+/**
+  * 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_MSG);
+}