Revision 0:7734401cc1b4, committed 2014-02-04

Comitter:

icraggs

Date:

Tue Feb 04 22:31:32 2014 +0000

Child:

1:069ae45b7070

Commit message:

First version of MQTT library

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MQTTConnect.h	Tue Feb 04 22:31:32 2014 +0000
@@ -0,0 +1,111 @@
+/*******************************************************************************
+ * 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
+ *******************************************************************************/
+
+#ifndef MQTTCONNECT_H_
+#define MQTTCONNECT_H_
+
+	typedef union
+	{
+		unsigned char all;	/**< all connect flags */
+#if defined(REVERSED)
+		struct
+		{
+			unsigned int username : 1;			/**< 3.1 user name */
+			unsigned int password : 1; 			/**< 3.1 password */
+			unsigned int willRetain : 1;		/**< will retain setting */
+			unsigned int willQoS : 2;				/**< will QoS value */
+			unsigned int will : 1;			    /**< will flag */
+			unsigned int cleansession : 1;	  /**< clean session flag */
+			unsigned int : 1;	  	          /**< unused */
+		} bits;
+#else
+		struct
+		{
+			unsigned int : 1;	     					/**< unused */
+			unsigned int cleansession : 1;	  /**< cleansession flag */
+			unsigned int will : 1;			    /**< will flag */
+			unsigned int willQoS : 2;				/**< will QoS value */
+			unsigned int willRetain : 1;		/**< will retain setting */
+			unsigned int password : 1; 			/**< 3.1 password */
+			unsigned int username : 1;			/**< 3.1 user name */
+		} bits;
+#endif
+	} MQTTConnectFlags;	/**< connect flags byte */
+
+
+
+/**
+ * Defines the MQTT "Last Will and Testament" (LWT) settings for
+ * the connect packet.
+ */
+typedef struct
+{
+	/** The eyecatcher for this structure.  must be MQTW. */
+	char struct_id[4];
+	/** The version number of this structure.  Must be 0 */
+	int struct_version;
+	/** The LWT topic to which the LWT message will be published. */
+	MQTTString topicName;
+	/** The LWT payload. */
+	MQTTString message;
+	/**
+      * The retained flag for the LWT message (see MQTTAsync_message.retained).
+      */
+	int retained;
+	/**
+      * The quality of service setting for the LWT message (see
+      * MQTTAsync_message.qos and @ref qos).
+      */
+	int qos;
+} MQTTPacket_willOptions;
+
+
+#define MQTTPacket_willOptions_initializer { {'M', 'Q', 'T', 'W'}, 0, {NULL, {0, NULL}}, {NULL, {0, NULL}}, 0, 0 }
+
+
+typedef struct
+{
+	/** The eyecatcher for this structure.  must be MQTC. */
+	char struct_id[4];
+	/** The version number of this structure.  Must be 0, 1 or 2.
+	  * 0 signifies no SSL options and no serverURIs
+	  * 1 signifies no serverURIs
+	  */
+	int struct_version;
+	/** Version of MQTT to be used.  3 = 3.1 4 = 3.1.1
+	  */
+	int MQTTVersion;
+	MQTTString clientID;
+	int keepAliveInterval;
+	int cleansession;
+	int willFlag;
+	MQTTPacket_willOptions will;
+	MQTTString username;
+	MQTTString password;
+} MQTTPacket_connectData;
+
+#define MQTTPacket_connectData_initializer { {'M', 'Q', 'T', 'W'}, 0, 3, {NULL, {0, NULL}}, 0, 1, 0, \
+		MQTTPacket_willOptions_initializer, {NULL, {0, NULL}}, {NULL, {0, NULL}} }
+
+int MQTTSerialize_connect(char* buf, int buflen, MQTTPacket_connectData* options);
+int MQTTDeserialize_connect(MQTTPacket_connectData* data, char* buf, int len);
+
+int MQTTSerialize_connack(char* buf, int buflen, int connack_rc);
+int MQTTDeserialize_connack(int* connack_rc, char* buf, int buflen);
+
+int MQTTSerialize_disconnect(char* buf, int buflen);
+
+#endif /* MQTTCONNECT_H_ */

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MQTTConnectClient.c	Tue Feb 04 22:31:32 2014 +0000
@@ -0,0 +1,187 @@
+/*******************************************************************************
+ * 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(char* buf, int buflen, MQTTPacket_connectData* options)
+{
+	char *ptr = buf;
+	MQTTHeader header;
+	MQTTConnectFlags flags;
+	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 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(int* connack_rc, char* buf, int buflen)
+{
+	MQTTHeader header;
+	char* curdata = buf;
+	char* enddata = NULL;
+	int rc = 0;
+	int mylen;
+	int compression;
+
+	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;
+
+	compression = readChar(&curdata);
+	*connack_rc = readChar(&curdata);
+
+	rc = 1;
+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(char* buf, int buflen)
+{
+	MQTTHeader header;
+	int rc = -1;
+	char *ptr = buf;
+
+	FUNC_ENTRY;
+	if (buflen < 2)
+	{
+		rc = MQTTPACKET_BUFFER_TOO_SHORT;
+		goto exit;
+	}
+	header.byte = 0;
+	header.bits.type = DISCONNECT;
+	writeChar(&ptr, header.byte); /* write header */
+
+	ptr += MQTTPacket_encode(ptr, 0); /* write remaining length */
+	rc = ptr - buf;
+exit:
+	FUNC_EXIT_RC(rc);
+	return rc;
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MQTTConnectServer.c	Tue Feb 04 22:31:32 2014 +0000
@@ -0,0 +1,143 @@
+/*******************************************************************************
+ * 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) ? 1 : 0)
+
+
+/**
+  * 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, "MQIdsp",
+			min(6, protocol->lenstring.len)))
+		rc = 1;
+	else if (version == 3 && memcmp(protocol->lenstring.data, "MQTT",
+			min(4, protocol->lenstring.len)))
+		rc = 1;
+
+	return 1;
+}
+
+
+/**
+  * 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, char* buf, int len)
+{
+	MQTTHeader header;
+	MQTTConnectFlags flags;
+	char* curdata = buf;
+	char* enddata = &buf[len];
+	int rc = 0;
+	MQTTString Protocol;
+	int version;
+	int mylen = 0;
+
+	FUNC_ENTRY;
+	header.byte = readChar(&curdata);
+
+	curdata += (rc = 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;
+		if (flags.bits.will)
+		{
+			data->willFlag = 1;
+			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 
+  * @return serialized length, or error if 0
+  */
+int MQTTSerialize_connack(char* buf, int buflen, int connack_rc)
+{
+	MQTTHeader header;
+	int rc = 0;
+	char *ptr = buf;
+
+	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 */
+
+	writeChar(&ptr, 0); /* compression byte - not used */
+	writeChar(&ptr, connack_rc);
+
+	rc = ptr - buf;
+exit:
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MQTTDeserializePublish.c	Tue Feb 04 22:31:32 2014 +0000
@@ -0,0 +1,105 @@
+/*******************************************************************************
+ * 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) ? 1 : 0)
+
+/**
+  * Deserializes the supplied (wire) buffer into publish data
+  * @param dup returned integer - the MQTT dup flag
+  * @param qos returned integer - the MQTT QoS value
+  * @param retained returned integer - the MQTT retained flag
+  * @param packetid returned integer - the MQTT packet identifier
+  * @param topicName returned MQTTString - the MQTT topic in the publish
+  * @param payload returned byte buffer - the MQTT publish payload
+  * @param payloadlen returned integer - the length of the MQTT payload
+  * @param buf the raw buffer data, of the correct length determined by the remaining length field
+  * @param buflen the length in bytes of the data in the supplied buffer
+  * @return error code.  1 is success
+  */
+int MQTTDeserialize_publish(int* dup, int* qos, int* retained, int* packetid, MQTTString* topicName,
+		char** payload, int* payloadlen, char* buf, int buflen)
+{
+	MQTTHeader header;
+	char* curdata = buf;
+	char* enddata = NULL;
+	int rc = 0;
+	int mylen = 0;
+
+	FUNC_ENTRY;
+	header.byte = readChar(&curdata);
+	*dup = header.bits.dup;
+	*qos = header.bits.qos;
+	*retained = header.bits.retain;
+
+	curdata += (rc = MQTTPacket_decodeBuf(curdata, &mylen)); /* read remaining length */
+	enddata = curdata + mylen;
+
+	if (!readMQTTLenString(topicName, &curdata, enddata) ||
+		enddata - curdata < 0) /* do we have enough data to read the protocol version byte? */
+		goto exit;
+
+	if (*qos > 0)
+		*packetid = readInt(&curdata);
+
+	*payloadlen = enddata - curdata;
+	*payload = curdata;
+	rc = 1;
+exit:
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+
+
+
+/**
+  * Deserializes the supplied (wire) buffer into an ack
+  * @param type returned integer - the MQTT packet type
+  * @param dup returned integer - the MQTT dup flag
+  * @param packetid returned integer - the MQTT packet identifier
+  * @param buf the raw buffer data, of the correct length determined by the remaining length field
+  * @param buflen the length in bytes of the data in the supplied buffer
+  * @return error code.  1 is success, 0 is failure
+  */
+int MQTTDeserialize_ack(int* type, int* dup, int* packetid, char* buf, int buflen)
+{
+	MQTTHeader header;
+	char* curdata = buf;
+	char* enddata = NULL;
+	int rc = 0;
+	int mylen;
+
+	FUNC_ENTRY;
+	header.byte = readChar(&curdata);
+	*dup = header.bits.dup;
+	*type = header.bits.type;
+
+	curdata += (rc = MQTTPacket_decodeBuf(curdata, &mylen)); /* read remaining length */
+	enddata = curdata + mylen;
+
+	if (enddata - curdata < 2)
+		goto exit;
+	*packetid = readInt(&curdata);
+
+	rc = 1;
+exit:
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MQTTPacket.c	Tue Feb 04 22:31:32 2014 +0000
@@ -0,0 +1,283 @@
+/*******************************************************************************
+ * 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>
+
+/**
+ * Encodes the message length according to the MQTT algorithm
+ * @param buf the buffer into which the encoded data is written
+ * @param length the length to be encoded
+ * @return the number of bytes written to buffer
+ */
+int MQTTPacket_encode(char* buf, int length)
+{
+	int rc = 0;
+
+	FUNC_ENTRY;
+	do
+	{
+		char d = length % 128;
+		length /= 128;
+		/* if there are more digits to encode, set the top bit of this digit */
+		if (length > 0)
+			d |= 0x80;
+		buf[rc++] = d;
+	} while (length > 0);
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+
+
+/**
+ * Decodes the message length according to the MQTT algorithm
+ * @param getcharfn pointer to function to read the next character from the data source
+ * @param value the decoded length returned
+ * @return the number of bytes read from the socket
+ */
+int MQTTPacket_decode(int (*getcharfn)(char*, int), int* value)
+{
+	char c;
+	int multiplier = 1;
+	int len = 0;
+#define MAX_NO_OF_REMAINING_LENGTH_BYTES 4
+
+	FUNC_ENTRY;
+	*value = 0;
+	do
+	{
+		int rc = MQTTPACKET_READ_ERROR;
+
+		if (++len > MAX_NO_OF_REMAINING_LENGTH_BYTES)
+		{
+			rc = MQTTPACKET_READ_ERROR;	/* bad data */
+			goto exit;
+		}
+		rc = (*getcharfn)(&c, 1);
+		if (rc != 1)
+			goto exit;
+		*value += (c & 127) * multiplier;
+		multiplier *= 128;
+	} while ((c & 128) != 0);
+exit:
+	FUNC_EXIT_RC(len);
+	return len;
+}
+
+
+int MQTTPacket_len(int rem_len)
+{
+	rem_len += 1; /* header byte */
+
+	/* now remaining_length field */
+	if (rem_len < 128)
+		rem_len += 1;
+	else if (rem_len < 16384)
+		rem_len += 2;
+	else if (rem_len < 2097151)
+		rem_len += 3;
+	else
+		rem_len += 4;
+	return rem_len;
+}
+
+
+static char* bufptr;
+
+int bufchar(char* c, int count)
+{
+	int i;
+
+	for (i = 0; i < count; ++i)
+		*c = *bufptr++;
+	return count;
+}
+
+
+int MQTTPacket_decodeBuf(char* buf, int* value)
+{
+	bufptr = buf;
+	return MQTTPacket_decode(bufchar, value);
+}
+
+
+/**
+ * Calculates an integer from two bytes read from the input buffer
+ * @param pptr pointer to the input buffer - incremented by the number of bytes used & returned
+ * @return the integer value calculated
+ */
+int readInt(char** pptr)
+{
+	char* ptr = *pptr;
+	int len = 256*((unsigned char)(*ptr)) + (unsigned char)(*(ptr+1));
+	*pptr += 2;
+	return len;
+}
+
+
+/**
+ * Reads one character from the input buffer.
+ * @param pptr pointer to the input buffer - incremented by the number of bytes used & returned
+ * @return the character read
+ */
+char readChar(char** pptr)
+{
+	char c = **pptr;
+	(*pptr)++;
+	return c;
+}
+
+
+/**
+ * Writes one character to an output buffer.
+ * @param pptr pointer to the output buffer - incremented by the number of bytes used & returned
+ * @param c the character to write
+ */
+void writeChar(char** pptr, char c)
+{
+	**pptr = c;
+	(*pptr)++;
+}
+
+
+/**
+ * Writes an integer as 2 bytes to an output buffer.
+ * @param pptr pointer to the output buffer - incremented by the number of bytes used & returned
+ * @param anInt the integer to write
+ */
+void writeInt(char** pptr, int anInt)
+{
+	**pptr = (char)(anInt / 256);
+	(*pptr)++;
+	**pptr = (char)(anInt % 256);
+	(*pptr)++;
+}
+
+
+/**
+ * Writes a "UTF" string to an output buffer.  Converts C string to length-delimited.
+ * @param pptr pointer to the output buffer - incremented by the number of bytes used & returned
+ * @param string the C string to write
+ */
+void writeCString(char** pptr, char* string)
+{
+	int len = strlen(string);
+	writeInt(pptr, len);
+	memcpy(*pptr, string, len);
+	*pptr += len;
+}
+
+
+int getLenStringLen(char* ptr)
+{
+	int len = 256*((unsigned char)(*ptr)) + (unsigned char)(*(ptr+1));
+	return len;
+}
+
+
+void writeMQTTString(char** pptr, MQTTString mqttstring)
+{
+	if (mqttstring.lenstring.len > 0)
+	{
+		writeInt(pptr, mqttstring.lenstring.len);
+		memcpy(*pptr, mqttstring.lenstring.data, mqttstring.lenstring.len);
+		*pptr += mqttstring.lenstring.len;
+	}
+	else if (mqttstring.cstring)
+		writeCString(pptr, mqttstring.cstring);
+}
+
+
+/**
+ * @param mqttstring the MQTTString structure into which the data is to be read
+ * @param pptr pointer to the output buffer - incremented by the number of bytes used & returned
+ * @param enddata pointer to the end of the data: do not read beyond
+ * @return 1 if successful, 0 if not
+ */
+int readMQTTLenString(MQTTString* mqttstring, char** pptr, char* enddata)
+{
+	int rc = 0;
+
+	FUNC_ENTRY;
+	/* the first two bytes are the length of the string */
+	if (enddata - (*pptr) > 1) /* enough length to read the integer? */
+	{
+		mqttstring->lenstring.len = readInt(pptr); /* increments pptr to point past length */
+		if (&(*pptr)[mqttstring->lenstring.len] <= enddata)
+		{
+			mqttstring->lenstring.data = *pptr;
+			*pptr += mqttstring->lenstring.len;
+			rc = 1;
+		}
+	}
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+
+
+/**
+ * Return the length of the MQTTstring - C string if there is one, otherwise the length delimited string
+ * @param mqttstring the string to return the length of
+ * @return the length of the string
+ */
+int MQTTstrlen(MQTTString mqttstring)
+{
+	int rc = 0;
+
+	if (mqttstring.cstring)
+		rc = strlen(mqttstring.cstring);
+	else
+		rc = mqttstring.lenstring.len;
+	return rc;
+}
+
+
+/**
+ * Helper function to read packet data from some source into a buffer
+ * @param buf the buffer into which the packet will be serialized
+ * @param buflen the length in bytes of the supplied buffer
+ * @param getfn pointer to a function which will read any number of bytes from the needed source
+ * @return integer MQTT packet type, or -1 on error
+ */
+int MQTTPacket_read(char* buf, int buflen, int (*getfn)(char*, int))
+{
+	int rc = -1;
+	MQTTHeader header;
+	int len = 0;
+	int rem_len = 0;
+
+	/* 1. read the header byte.  This has the packet type in it */
+	if ((*getfn)(buf, 1) != 1)
+		goto exit;
+
+	len = 1;
+	/* 2. read the remaining length.  This is variable in itself */
+	MQTTPacket_decode(getfn, &rem_len);
+	len += MQTTPacket_encode(buf + 1, rem_len); /* put the original remaining length back into the buffer */
+
+	/* 3. read the rest of the buffer using a callback to supply the rest of the data */
+	if ((*getfn)(buf + len, rem_len) != rem_len)
+		goto exit;
+
+	header.byte = buf[0];
+	rc = header.bits.type;
+exit:
+	return rc;
+}
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MQTTPacket.h	Tue Feb 04 22:31:32 2014 +0000
@@ -0,0 +1,105 @@
+/*******************************************************************************
+ * 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
+ *******************************************************************************/
+
+#ifndef MQTTPACKET_H_
+#define MQTTPACKET_H_
+
+#if defined(__cplusplus) /* If this is a C++ compiler, use C linkage */
+extern "C" {
+#endif
+
+enum errors
+{
+	MQTTPACKET_BUFFER_TOO_SHORT = -2,
+	MQTTPACKET_READ_ERROR = -1,
+	MQTTPACKET_READ_COMPLETE,
+};
+
+enum msgTypes
+{
+	CONNECT = 1, CONNACK, PUBLISH, PUBACK, PUBREC, PUBREL,
+	PUBCOMP, SUBSCRIBE, SUBACK, UNSUBSCRIBE, UNSUBACK,
+	PINGREQ, PINGRESP, DISCONNECT
+};
+
+/**
+ * Bitfields for the MQTT header byte.
+ */
+typedef union
+{
+	/*unsigned*/ char byte;	/**< the whole byte */
+#if defined(REVERSED)
+	struct
+	{
+		unsigned int type : 4;			/**< message type nibble */
+		unsigned int dup : 1;				/**< DUP flag bit */
+		unsigned int qos : 2;				/**< QoS value, 0, 1 or 2 */
+		unsigned int retain : 1;		/**< retained flag bit */
+	} bits;
+#else
+	struct
+	{
+		unsigned int retain : 1;		/**< retained flag bit */
+		unsigned int qos : 2;				/**< QoS value, 0, 1 or 2 */
+		unsigned int dup : 1;				/**< DUP flag bit */
+		unsigned int type : 4;			/**< message type nibble */
+	} bits;
+#endif
+} MQTTHeader;
+
+typedef struct
+{
+	int len;
+	char* data;
+} MQTTLenString;
+
+typedef struct
+{
+	char* cstring;
+	MQTTLenString lenstring;
+} MQTTString;
+
+#define MQTTString_initializer {NULL, {0, NULL}}
+
+int MQTTstrlen(MQTTString mqttstring);
+
+#include "MQTTConnect.h"
+#include "MQTTPublish.h"
+#include "MQTTSubscribe.h"
+#include "MQTTUnsubscribe.h"
+
+int MQTTDeserialize_ack(int* type, int* dup, int* packetid, char* buf, int buflen);
+
+int MQTTPacket_len(int rem_len);
+
+int MQTTPacket_encode(char* buf, int length);
+int MQTTPacket_decode(int (*getcharfn)(char*, int), int* value);
+int MQTTPacket_decodeBuf(char* buf, int* value);
+
+int readInt(char** pptr);
+char readChar(char** pptr);
+void writeChar(char** pptr, char c);
+void writeInt(char** pptr, int anInt);
+int readMQTTLenString(MQTTString* mqttstring, char** pptr, char* enddata);
+void writeCString(char** pptr, char* string);
+void writeMQTTString(char** pptr, MQTTString mqttstring);
+
+#ifdef __cplusplus /* If this is a C++ compiler, use C linkage */
+}
+#endif
+
+
+#endif /* MQTTPACKET_H_ */

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MQTTPublish.h	Tue Feb 04 22:31:32 2014 +0000
@@ -0,0 +1,30 @@
+/*******************************************************************************
+ * 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
+ *******************************************************************************/
+
+#ifndef MQTTPUBLISH_H_
+#define MQTTPUBLISH_H_
+
+int MQTTSerialize_publish(char* buf, int buflen, int dup, int qos, int retained, int packetid, MQTTString topicName,
+		char* payload, int payloadlen);
+
+int MQTTDeserialize_publish(int* dup, int* qos, int* retained, int* packetid, MQTTString* topicName,
+		char** payload, int* payloadlen, char* buf, int len);
+
+int MQTTSerialize_puback(char* buf, int buflen, int packetid);
+int MQTTSerialize_pubrel(char* buf, int buflen, int packetid, int dup);
+int MQTTSerialize_pubcomp(char* buf, int buflen, int packetid);
+
+#endif /* MQTTPUBLISH_H_ */

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MQTTSerializePublish.c	Tue Feb 04 22:31:32 2014 +0000
@@ -0,0 +1,168 @@
+/*******************************************************************************
+ * 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 publish packet that would be produced using the supplied parameters
+  * @param qos the MQTT QoS of the publish (packetid is omitted for QoS 0)
+  * @param topicName the topic name to be used in the publish  
+  * @param payloadlen the length of the payload to be sent
+  * @return the length of buffer needed to contain the serialized version of the packet
+  */
+int MQTTSerialize_publishLength(int qos, MQTTString topicName, int payloadlen)
+{
+	int len = 0;
+
+	len += 2 + MQTTstrlen(topicName) + payloadlen;
+	if (qos > 0)
+		len += 2; /* packetid */
+	return len;
+}
+
+
+/**
+  * Serializes the supplied publish data into the supplied buffer, ready for sending
+  * @param buf the buffer into which the packet will be serialized
+  * @param buflen the length in bytes of the supplied buffer
+  * @param dup integer - the MQTT dup flag
+  * @param qos integer - the MQTT QoS value
+  * @param retained integer - the MQTT retained flag
+  * @param packetid integer - the MQTT packet identifier
+  * @param topicName MQTTString - the MQTT topic in the publish
+  * @param payload byte buffer - the MQTT publish payload
+  * @param payloadlen integer - the length of the MQTT payload
+  * @return the length of the serialized data.  <= 0 indicates error
+  */
+int MQTTSerialize_publish(char* buf, int buflen, int dup, int qos, int retained, int packetid, MQTTString topicName,
+		char* payload, int payloadlen)
+{
+	char *ptr = buf;
+	MQTTHeader header;
+	int rem_len = 0;
+	int rc = 0;
+
+	FUNC_ENTRY;
+	if (MQTTPacket_len(rem_len = MQTTSerialize_publishLength(qos, topicName, payloadlen)) > buflen)
+	{
+		rc = MQTTPACKET_BUFFER_TOO_SHORT;
+		goto exit;
+	}
+
+	header.bits.type = PUBLISH;
+	header.bits.dup = dup;
+	header.bits.qos = qos;
+	header.bits.retain = retained;
+	writeChar(&ptr, header.byte); /* write header */
+
+	ptr += MQTTPacket_encode(ptr, rem_len); /* write remaining length */;
+
+	writeMQTTString(&ptr, topicName);
+
+	if (qos > 0)
+		writeInt(&ptr, packetid);
+
+	memcpy(ptr, payload, payloadlen);
+	ptr += payloadlen;
+
+	rc = ptr - buf;
+
+exit:
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+
+
+
+/**
+  * Serializes the ack 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 type integer - the MQTT packet type
+  * @param dup integer - the MQTT dup flag
+  * @param packetid integer - the MQTT packet identifier
+  * @return serialized length, or error if 0
+  */
+int MQTTSerialize_ack(char* buf, int buflen, int type, int dup, int packetid)
+{
+	MQTTHeader header;
+	int rc = 0;
+	char *ptr = buf;
+
+	FUNC_ENTRY;
+	if (buflen < 4)
+	{
+		rc = MQTTPACKET_BUFFER_TOO_SHORT;
+		goto exit;
+	}
+	header.bits.type = type;
+	header.bits.dup = dup;
+	header.bits.qos = 0;
+	writeChar(&ptr, header.byte); /* write header */
+
+	ptr += MQTTPacket_encode(ptr, 2); /* write remaining length */
+	writeInt(&ptr, packetid);
+	rc = ptr - buf;
+exit:
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+
+
+/**
+  * Serializes a puback 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 packetid integer - the MQTT packet identifier
+  * @return serialized length, or error if 0
+  */
+int MQTTSerialize_puback(char* buf, int buflen, int packetid)
+{
+	return MQTTSerialize_ack(buf, buflen, PUBACK, packetid, 0);
+}
+
+
+/**
+  * Serializes a pubrel 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 dup integer - the MQTT dup flag
+  * @param packetid integer - the MQTT packet identifier
+  * @return serialized length, or error if 0
+  */
+int MQTTSerialize_pubrel(char* buf, int buflen,  int dup, int packetid)
+{
+	return MQTTSerialize_ack(buf, buflen, PUBREL, packetid, dup);
+}
+
+
+/**
+  * Serializes a pubrel 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 packetid integer - the MQTT packet identifier
+  * @return serialized length, or error if 0
+  */
+int MQTTSerialize_pubcomp(char* buf, int buflen, int packetid)
+{
+	return MQTTSerialize_ack(buf, buflen, PUBCOMP, packetid, 0);
+}
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MQTTSubscribe.h	Tue Feb 04 22:31:32 2014 +0000
@@ -0,0 +1,29 @@
+/*******************************************************************************
+ * 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
+ *******************************************************************************/
+
+#ifndef MQTTSUBSCRIBE_H_
+#define MQTTSUBSCRIBE_H_
+
+int MQTTSerialize_subscribe(char* buf, int buflen, int dup, int packetid, int count, MQTTString topicFilters[], int requestedQoSs[]);
+
+int MQTTDeserialize_subscribe(int* dup, int* packetid, int maxcount, int* count, MQTTString topicFilters[], int requestedQoSs[], char* buf, int len);
+
+int MQTTSerialize_suback(char* buf, int buflen, int packetid, int count, int* grantedQoSs);
+
+int MQTTDeserialize_suback(int* packetid, int maxcount, int* count, int grantedQoSs[], char* buf, int len);
+
+
+#endif /* MQTTSUBSCRIBE_H_ */

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MQTTSubscribeClient.c	Tue Feb 04 22:31:32 2014 +0000
@@ -0,0 +1,134 @@
+/*******************************************************************************
+ * 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 subscribe packet that would be produced using the supplied parameters
+  * @param count the number of topic filter strings in topicFilters
+  * @param topicFilters the array of topic filter strings to be used in the publish
+  * @return the length of buffer needed to contain the serialized version of the packet
+  */
+int MQTTSerialize_subscribeLength(int count, MQTTString topicFilters[])
+{
+	int i;
+	int len = 2; /* packetid */
+
+	for (i = 0; i < count; ++i)
+		len += 2 + MQTTstrlen(topicFilters[i]) + 1; /* length + topic + req_qos */
+	return len;
+}
+
+
+/**
+  * Serializes the supplied subscribe data into the supplied buffer, ready for sending
+  * @param buf the buffer into which the packet will be serialized
+  * @param buflen the length in bytes of the supplied bufferr
+  * @param dup integer - the MQTT dup flag
+  * @param packetid integer - the MQTT packet identifier
+  * @param count - number of members in the topicFilters and reqQos arrays
+  * @param topicFilters - array of topic filter names
+  * @param requestedQoSs - array of requested QoS
+  * @return the length of the serialized data.  <= 0 indicates error
+  */
+int MQTTSerialize_subscribe(char* buf, int buflen, int dup, int packetid, int count, MQTTString topicFilters[], int requestedQoSs[])
+{
+	char *ptr = buf;
+	MQTTHeader header;
+	int rem_len = 0;
+	int rc = 0;
+	int i = 0;
+
+	FUNC_ENTRY;
+	if (MQTTPacket_len(rem_len = MQTTSerialize_subscribeLength(count, topicFilters)) > buflen)
+	{
+		rc = MQTTPACKET_BUFFER_TOO_SHORT;
+		goto exit;
+	}
+
+	header.byte = 0;
+	header.bits.type = SUBSCRIBE;
+	header.bits.dup = dup;
+	header.bits.qos = 1;
+	writeChar(&ptr, header.byte); /* write header */
+
+	ptr += MQTTPacket_encode(ptr, rem_len); /* write remaining length */;
+
+	writeInt(&ptr, packetid);
+
+	for (i = 0; i < count; ++i)
+	{
+		writeMQTTString(&ptr, topicFilters[i]);
+		writeChar(&ptr, requestedQoSs[i]);
+	}
+
+	rc = ptr - buf;
+exit:
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+
+
+
+/**
+  * Deserializes the supplied (wire) buffer into suback data
+  * @param packetid returned integer - the MQTT packet identifier
+  * @param maxcount - the maximum number of members allowed in the grantedQoSs array
+  * @param count returned integer - number of members in the grantedQoSs array
+  * @param grantedQoSs returned array of integers - the granted qualities of service
+  * @param buf the raw buffer data, of the correct length determined by the remaining length field
+  * @param buflen the length in bytes of the data in the supplied buffer
+  * @return error code.  1 is success, 0 is failure
+  */
+int MQTTDeserialize_suback(int* packetid, int maxcount, int* count, int grantedQoSs[], char* buf, int buflen)
+{
+	MQTTHeader header;
+	char* curdata = buf;
+	char* enddata = NULL;
+	int rc = 0;
+	int mylen;
+
+	FUNC_ENTRY;
+	header.byte = readChar(&curdata);
+
+	curdata += (rc = MQTTPacket_decodeBuf(curdata, &mylen)); /* read remaining length */
+	enddata = curdata + mylen;
+	if (enddata - curdata < 2)
+		goto exit;
+
+	*packetid = readInt(&curdata);
+
+	*count = 0;
+	while (curdata < enddata)
+	{
+		if (*count > maxcount)
+		{
+			rc = -1;
+			goto exit;
+		}
+		grantedQoSs[(*count)++] = readChar(&curdata);
+	}
+
+	rc = 1;
+exit:
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MQTTSubscribeServer.c	Tue Feb 04 22:31:32 2014 +0000
@@ -0,0 +1,110 @@
+/*******************************************************************************
+ * 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>
+
+
+/**
+  * Deserializes the supplied (wire) buffer into subscribe data
+  * @param dup integer returned - the MQTT dup flag
+  * @param packetid integer returned - the MQTT packet identifier
+  * @param maxcount - the maximum number of members allowed in the topicFilters and requestedQoSs arrays
+  * @param count - number of members in the topicFilters and requestedQoSs arrays
+  * @param topicFilters - array of topic filter names
+  * @param requestedQoSs - array of requested QoS
+  * @param buf the raw buffer data, of the correct length determined by the remaining length field
+  * @param buflen the length in bytes of the data in the supplied buffer
+  * @return the length of the serialized data.  <= 0 indicates error
+  */
+int MQTTDeserialize_subscribe(int* dup, int* packetid, int maxcount, int* count, MQTTString topicFilters[], int requestedQoSs[], 
+    char* buf, int buflen)
+{
+	MQTTHeader header;
+	char* curdata = buf;
+	char* enddata = NULL;
+	int rc = -1;
+	int mylen = 0;
+
+	FUNC_ENTRY;
+	header.byte = readChar(&curdata);
+	*dup = header.bits.dup;
+
+	curdata += (rc = MQTTPacket_decodeBuf(curdata, &mylen)); /* read remaining length */
+	enddata = curdata + mylen;
+
+	*packetid = readInt(&curdata);
+
+	*count = 0;
+	while (curdata < enddata)
+	{
+		if (!readMQTTLenString(&topicFilters[*count], &curdata, enddata))
+			goto exit;
+		if (curdata >= enddata) /* do we have enough data to read the req_qos version byte? */
+			goto exit;
+		requestedQoSs[*count] = readChar(&curdata);
+		(*count)++;
+	}
+
+	rc = 1;
+exit:
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+
+
+/**
+  * Serializes the supplied suback data into the supplied buffer, ready for sending
+  * @param buf the buffer into which the packet will be serialized
+  * @param buflen the length in bytes of the supplied buffer
+  * @param packetid integer - the MQTT packet identifier
+  * @param count - number of members in the grantedQoSs array
+  * @param grantedQoSs - array of granted QoS
+  * @return the length of the serialized data.  <= 0 indicates error
+  */
+int MQTTSerialize_suback(char* buf, int buflen, int packetid, int count, int* grantedQoSs)
+{
+	MQTTHeader header;
+	int rc = -1;
+	char *ptr = buf;
+	int i;
+
+	FUNC_ENTRY;
+	if (buflen < 2 + count)
+	{
+		rc = MQTTPACKET_BUFFER_TOO_SHORT;
+		goto exit;
+	}
+	header.byte = 0;
+	header.bits.type = SUBACK;
+	writeChar(&ptr, header.byte); /* write header */
+
+	ptr += MQTTPacket_encode(ptr, 2 + count); /* write remaining length */
+
+	writeInt(&ptr, packetid);
+
+	for (i = 0; i < count; ++i)
+		writeChar(&ptr, grantedQoSs[i]);
+
+	rc = ptr - buf;
+exit:
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MQTTUnsubscribe.h	Tue Feb 04 22:31:32 2014 +0000
@@ -0,0 +1,28 @@
+/*******************************************************************************
+ * 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
+ *******************************************************************************/
+
+#ifndef MQTTUNSUBSCRIBE_H_
+#define MQTTUNSUBSCRIBE_H_
+
+int MQTTSerialize_unsubscribe(char* buf, int buflen, int dup, int packetid, int count, MQTTString topicFilters[]);
+
+int MQTTDeserialize_unsubscribe(int* dup, int* packetid, int max_count, int* count, MQTTString topicFilters[], char* buf, int len);
+
+int MQTTSerialize_unsuback(char* buf, int buflen, int packetid);
+
+int MQTTDeserialize_unsuback(int* packetid, char* buf, int len);
+
+#endif /* MQTTUNSUBSCRIBE_H_ */

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MQTTUnsubscribeClient.c	Tue Feb 04 22:31:32 2014 +0000
@@ -0,0 +1,105 @@
+/*******************************************************************************
+ * 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 unsubscribe packet that would be produced using the supplied parameters
+  * @param count the number of topic filter strings in topicFilters
+  * @param topicFilters the array of topic filter strings to be used in the publish
+  * @return the length of buffer needed to contain the serialized version of the packet
+  */
+int MQTTSerialize_unsubscribeLength(int count, MQTTString topicFilters[])
+{
+	int i;
+	int len = 2; /* packetid */
+
+	for (i = 0; i < count; ++i)
+		len += 2 + MQTTstrlen(topicFilters[i]); /* length + topic*/
+	return len;
+}
+
+
+/**
+  * Serializes the supplied unsubscribe data into the supplied buffer, ready for sending
+  * @param buf the raw buffer data, of the correct length determined by the remaining length field
+  * @param buflen the length in bytes of the data in the supplied buffer
+  * @param dup integer - the MQTT dup flag
+  * @param packetid integer - the MQTT packet identifier
+  * @param count - number of members in the topicFilters array
+  * @param topicFilters - array of topic filter names
+  * @return the length of the serialized data.  <= 0 indicates error
+  */
+int MQTTSerialize_unsubscribe(char* buf, int buflen, int dup, int packetid, int count, MQTTString topicFilters[])
+{
+	char *ptr = buf;
+	MQTTHeader header;
+	int rem_len = 0;
+	int rc = -1;
+	int i = 0;
+
+	FUNC_ENTRY;
+	if (MQTTPacket_len(rem_len = MQTTSerialize_unsubscribeLength(count, topicFilters)) > buflen)
+	{
+		rc = MQTTPACKET_BUFFER_TOO_SHORT;
+		goto exit;
+	}
+
+	header.byte = 0;
+	header.bits.type = SUBSCRIBE;
+	header.bits.dup = dup;
+	header.bits.qos = 1;
+	writeChar(&ptr, header.byte); /* write header */
+
+	ptr += MQTTPacket_encode(ptr, rem_len); /* write remaining length */;
+
+	writeInt(&ptr, packetid);
+
+	for (i = 0; i < count; ++i)
+		writeMQTTString(&ptr, topicFilters[i]);
+
+	rc = ptr - buf;
+exit:
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+
+
+/**
+  * Deserializes the supplied (wire) buffer into unsuback data
+  * @param packetid returned integer - the MQTT packet identifier
+  * @param buf the raw buffer data, of the correct length determined by the remaining length field
+  * @param buflen the length in bytes of the data in the supplied buffer
+  * @return error code.  1 is success, 0 is failure
+  */
+int MQTTDeserialize_unsuback(int* packetid, char* buf, int buflen)
+{
+	int type = 0;
+	int dup = 0;
+	int rc = 0;
+
+	FUNC_ENTRY;
+	rc = MQTTDeserialize_ack(&type, &dup, packetid, buf, buflen);
+	if (type == UNSUBACK)
+		rc = 1;
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MQTTUnsubscribeServer.c	Tue Feb 04 22:31:32 2014 +0000
@@ -0,0 +1,99 @@
+/*******************************************************************************
+ * 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>
+
+
+/**
+  * Deserializes the supplied (wire) buffer into unsubscribe data
+  * @param dup integer returned - the MQTT dup flag
+  * @param packetid integer returned - the MQTT packet identifier
+  * @param maxcount - the maximum number of members allowed in the topicFilters and requestedQoSs arrays
+  * @param count - number of members in the topicFilters and requestedQoSs arrays
+  * @param topicFilters - array of topic filter names
+  * @param buf the raw buffer data, of the correct length determined by the remaining length field
+  * @param buflen the length in bytes of the data in the supplied buffer
+  * @return the length of the serialized data.  <= 0 indicates error
+  */
+int MQTTDeserialize_unsubscribe(int* dup, int* packetid, int maxcount, int* count, MQTTString topicFilters[], char* buf, int len)
+{
+	MQTTHeader header;
+	char* curdata = buf;
+	char* enddata = NULL;
+	int rc = 0;
+	int mylen = 0;
+
+	FUNC_ENTRY;
+	header.byte = readChar(&curdata);
+	*dup = header.bits.dup;
+
+	curdata += (rc = MQTTPacket_decodeBuf(curdata, &mylen)); /* read remaining length */
+	enddata = curdata + mylen;
+
+	*packetid = readInt(&curdata);
+
+	*count = 0;
+	while (curdata < enddata)
+	{
+		if (!readMQTTLenString(&topicFilters[*count], &curdata, enddata))
+			goto exit;
+		(*count)++;
+	}
+
+	rc = 1;
+exit:
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+
+
+/**
+  * Serializes the supplied unsuback data into the supplied buffer, ready for sending
+  * @param buf the buffer into which the packet will be serialized
+  * @param buflen the length in bytes of the supplied buffer
+  * @param packetid integer - the MQTT packet identifier
+  * @return the length of the serialized data.  <= 0 indicates error
+  */
+int MQTTSerialize_unsuback(char* buf, int buflen, int packetid)
+{
+	MQTTHeader header;
+	int rc = 0;
+	char *ptr = buf;
+
+	FUNC_ENTRY;
+	if (buflen < 2)
+	{
+		rc = MQTTPACKET_BUFFER_TOO_SHORT;
+		goto exit;
+	}
+	header.byte = 0;
+	header.bits.type = UNSUBACK;
+	writeChar(&ptr, header.byte); /* write header */
+
+	ptr += MQTTPacket_encode(ptr, 2); /* write remaining length */
+
+	writeInt(&ptr, packetid);
+
+	rc = ptr - buf;
+exit:
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/StackTrace.h	Tue Feb 04 22:31:32 2014 +0000
@@ -0,0 +1,71 @@
+/*******************************************************************************
+ * 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
+ *******************************************************************************/
+
+#ifndef STACKTRACE_H_
+#define STACKTRACE_H_
+
+#include <stdio.h>
+#define NOSTACKTRACE 1
+
+#if defined(NOSTACKTRACE)
+#define FUNC_ENTRY
+#define FUNC_ENTRY_NOLOG
+#define FUNC_ENTRY_MED
+#define FUNC_ENTRY_MAX
+#define FUNC_EXIT
+#define FUNC_EXIT_NOLOG
+#define FUNC_EXIT_MED
+#define FUNC_EXIT_MAX
+#define FUNC_EXIT_RC(x)
+#define FUNC_EXIT_MED_RC(x)
+#define FUNC_EXIT_MAX_RC(x)
+#else
+#if defined(WIN32)
+#define inline __inline
+#define FUNC_ENTRY StackTrace_entry(__FUNCTION__, __LINE__, TRACE_MINIMUM)
+#define FUNC_ENTRY_NOLOG StackTrace_entry(__FUNCTION__, __LINE__, -1)
+#define FUNC_ENTRY_MED StackTrace_entry(__FUNCTION__, __LINE__, TRACE_MEDIUM)
+#define FUNC_ENTRY_MAX StackTrace_entry(__FUNCTION__, __LINE__, TRACE_MAXIMUM)
+#define FUNC_EXIT StackTrace_exit(__FUNCTION__, __LINE__, NULL, TRACE_MINIMUM)
+#define FUNC_EXIT_NOLOG StackTrace_exit(__FUNCTION__, __LINE__, -1)
+#define FUNC_EXIT_MED StackTrace_exit(__FUNCTION__, __LINE__, NULL, TRACE_MEDIUM)
+#define FUNC_EXIT_MAX StackTrace_exit(__FUNCTION__, __LINE__, NULL, TRACE_MAXIMUM)
+#define FUNC_EXIT_RC(x) StackTrace_exit(__FUNCTION__, __LINE__, &x, TRACE_MINIMUM)
+#define FUNC_EXIT_MED_RC(x) StackTrace_exit(__FUNCTION__, __LINE__, &x, TRACE_MEDIUM)
+#define FUNC_EXIT_MAX_RC(x) StackTrace_exit(__FUNCTION__, __LINE__, &x, TRACE_MAXIMUM)
+#else
+#define FUNC_ENTRY StackTrace_entry(__func__, __LINE__, TRACE_MINIMUM)
+#define FUNC_ENTRY_NOLOG StackTrace_entry(__func__, __LINE__, -1)
+#define FUNC_ENTRY_MED StackTrace_entry(__func__, __LINE__, TRACE_MEDIUM)
+#define FUNC_ENTRY_MAX StackTrace_entry(__func__, __LINE__, TRACE_MAXIMUM)
+#define FUNC_EXIT StackTrace_exit(__func__, __LINE__, NULL, TRACE_MINIMUM)
+#define FUNC_EXIT_NOLOG StackTrace_exit(__func__, __LINE__, NULL, -1)
+#define FUNC_EXIT_MED StackTrace_exit(__func__, __LINE__, NULL, TRACE_MEDIUM)
+#define FUNC_EXIT_MAX StackTrace_exit(__func__, __LINE__, NULL, TRACE_MAXIMUM)
+#define FUNC_EXIT_RC(x) StackTrace_exit(__func__, __LINE__, &x, TRACE_MINIMUM)
+#define FUNC_EXIT_MED_RC(x) StackTrace_exit(__func__, __LINE__, &x, TRACE_MEDIUM)
+#define FUNC_EXIT_MAX_RC(x) StackTrace_exit(__func__, __LINE__, &x, TRACE_MAXIMUM)
+#endif
+#endif
+
+void StackTrace_entry(const char* name, int line, int trace);
+void StackTrace_exit(const char* name, int line, void* return_value, int trace);
+
+void StackTrace_printStack(FILE* dest);
+char* StackTrace_get(unsigned long);
+
+
+#endif /* STACKTRACE_H_ */