Azure IoT
A small footprint MQTT library
Dependents: STM32F746_iothub_client_sample_mqtt FXOS8700CQ_To_Azure_IoT f767zi_mqtt FXOS8700CQ_To_Azure_IoT ... more
Diff: mqtt_codec.c
- Revision:
- 0:ef4901974abc
- Child:
- 5:34779607059c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/mqtt_codec.c Fri Apr 08 12:01:23 2016 -0700
@@ -0,0 +1,956 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+#include <stdlib.h>
+#include <limits.h>
+#include "azure_c_shared_utility/gballoc.h"
+#include "azure_c_shared_utility/buffer_.h"
+#include "azure_c_shared_utility/macro_utils.h"
+#include "azure_c_shared_utility/xlogging.h"
+#include "azure_umqtt_c/mqtt_codec.h"
+
+#define PAYLOAD_OFFSET 5
+#define PACKET_TYPE_BYTE(p) ((uint8_t)(((uint8_t)(p)) & 0xf0))
+#define FLAG_VALUE_BYTE(p) ((uint8_t)(((uint8_t)(p)) & 0xf))
+
+#define USERNAME_FLAG 0x80
+#define PASSWORD_FLAG 0x40
+#define WILL_RETAIN_FLAG 0x20
+#define WILL_QOS_FLAG_ 0x18
+#define WILL_FLAG_FLAG 0x04
+#define CLEAN_SESSION_FLAG 0x02
+
+#define NEXT_128_CHUNK 0x80
+#define PUBLISH_DUP_FLAG 0x8
+#define PUBLISH_QOS_EXACTLY_ONCE 0x4
+#define PUBLISH_QOS_AT_LEAST_ONCE 0x2
+#define PUBLISH_QOS_RETAIN 0x1
+
+#define PROTOCOL_NUMBER 4
+#define CONN_FLAG_BYTE_OFFSET 7
+
+#define CONNECT_FIXED_HEADER_SIZE 2
+#define CONNECT_VARIABLE_HEADER_SIZE 10
+#define SUBSCRIBE_FIXED_HEADER_FLAG 0x2
+#define UNSUBSCRIBE_FIXED_HEADER_FLAG 0x2
+
+#define MAX_SEND_SIZE 0xFFFFFF7F
+
+#define CODEC_STATE_VALUES \
+ CODEC_STATE_FIXED_HEADER, \
+ CODEC_STATE_VAR_HEADER, \
+ CODEC_STATE_PAYLOAD
+
+DEFINE_ENUM(CODEC_STATE_RESULT, CODEC_STATE_VALUES);
+
+typedef struct MQTTCODEC_INSTANCE_TAG
+{
+ CONTROL_PACKET_TYPE currPacket;
+ CODEC_STATE_RESULT codecState;
+ size_t bufferOffset;
+ int headerFlags;
+ BUFFER_HANDLE headerData;
+ ON_PACKET_COMPLETE_CALLBACK packetComplete;
+ void* callContext;
+ uint8_t storeRemainLen[4];
+ size_t remainLenIndex;
+} MQTTCODEC_INSTANCE;
+
+typedef struct PUBLISH_HEADER_INFO_TAG
+{
+ const char* topicName;
+ uint16_t packetId;
+ const char* msgBuffer;
+ QOS_VALUE qualityOfServiceValue;
+} PUBLISH_HEADER_INFO;
+
+void byteutil_writeByte(uint8_t** buffer, uint8_t value)
+{
+ if (buffer != NULL)
+ {
+ **buffer = value;
+ (*buffer)++;
+ }
+}
+
+void byteutil_writeInt(uint8_t** buffer, uint16_t value)
+{
+ if (buffer != NULL)
+ {
+ **buffer = (char)(value / 256);
+ (*buffer)++;
+ **buffer = (char)(value % 256);
+ (*buffer)++;
+ }
+}
+
+void byteutil_writeUTF(uint8_t** buffer, const char* stringData, uint16_t len)
+{
+ if (buffer != NULL)
+ {
+ byteutil_writeInt(buffer, len);
+ (void)memcpy(*buffer, stringData, len);
+ *buffer += len;
+ }
+}
+
+CONTROL_PACKET_TYPE processControlPacketType(uint8_t pktByte, int* flags)
+{
+ CONTROL_PACKET_TYPE result;
+ result = PACKET_TYPE_BYTE(pktByte);
+ if (flags != NULL)
+ {
+ *flags = FLAG_VALUE_BYTE(pktByte);
+ }
+ return result;
+}
+
+static int addListItemsToUnsubscribePacket(BUFFER_HANDLE ctrlPacket, const char** payloadList, size_t payloadCount)
+{
+ int result = 0;
+ if (payloadList == NULL || ctrlPacket == NULL)
+ {
+ result = __LINE__;
+ }
+ else
+ {
+ for (size_t index = 0; index < payloadCount && result == 0; index++)
+ {
+ // Add the Payload
+ size_t offsetLen = BUFFER_length(ctrlPacket);
+ size_t topicLen = strlen(payloadList[index]);
+ if (topicLen > USHRT_MAX)
+ {
+ result = __LINE__;
+ }
+ else if (BUFFER_enlarge(ctrlPacket, topicLen + 2) != 0)
+ {
+ result = __LINE__;
+ }
+ else
+ {
+ uint8_t* iterator = BUFFER_u_char(ctrlPacket);
+ iterator += offsetLen;
+ byteutil_writeUTF(&iterator, payloadList[index], (uint16_t)topicLen);
+ }
+ }
+ }
+ return result;
+}
+
+static int addListItemsToSubscribePacket(BUFFER_HANDLE ctrlPacket, SUBSCRIBE_PAYLOAD* payloadList, size_t payloadCount)
+{
+ int result = 0;
+ if (payloadList == NULL || ctrlPacket == NULL)
+ {
+ result = __LINE__;
+ }
+ else
+ {
+ for (size_t index = 0; index < payloadCount && result == 0; index++)
+ {
+ // Add the Payload
+ size_t offsetLen = BUFFER_length(ctrlPacket);
+ size_t topicLen = strlen(payloadList[index].subscribeTopic);
+ if (topicLen > USHRT_MAX)
+ {
+ result = __LINE__;
+ }
+ else if (BUFFER_enlarge(ctrlPacket, topicLen + 2 + 1) != 0)
+ {
+ result = __LINE__;
+ }
+ else
+ {
+ uint8_t* iterator = BUFFER_u_char(ctrlPacket);
+ iterator += offsetLen;
+ byteutil_writeUTF(&iterator, payloadList[index].subscribeTopic, (uint16_t)topicLen);
+ *iterator = payloadList[index].qosReturn;
+ }
+ }
+ }
+ return result;
+}
+
+static int constructConnectVariableHeader(BUFFER_HANDLE ctrlPacket, const MQTT_CLIENT_OPTIONS* mqttOptions)
+{
+ int result = 0;
+ if (BUFFER_enlarge(ctrlPacket, CONNECT_VARIABLE_HEADER_SIZE) != 0)
+ {
+ result = __LINE__;
+ }
+ else
+ {
+ uint8_t* iterator = BUFFER_u_char(ctrlPacket);
+ if (iterator == NULL)
+ {
+ result = __LINE__;
+ }
+ else
+ {
+ byteutil_writeUTF(&iterator, "MQTT", 4);
+ byteutil_writeByte(&iterator, PROTOCOL_NUMBER);
+ byteutil_writeByte(&iterator, 0); // Flags will be entered later
+ byteutil_writeInt(&iterator, mqttOptions->keepAliveInterval);
+ result = 0;
+ }
+ }
+ return result;
+}
+
+static int constructPublishVariableHeader(BUFFER_HANDLE ctrlPacket, const PUBLISH_HEADER_INFO* publishHeader)
+{
+ int result = 0;
+ size_t topicLen = 0;
+ size_t spaceLen = 0;
+ size_t idLen = 0;
+
+ size_t currLen = BUFFER_length(ctrlPacket);
+
+ topicLen = strlen(publishHeader->topicName);
+ spaceLen += 2;
+
+ if (publishHeader->qualityOfServiceValue != DELIVER_AT_MOST_ONCE)
+ {
+ // Packet Id is only set if the QOS is not 0
+ idLen = 2;
+ }
+
+ if (topicLen > USHRT_MAX)
+ {
+ result = __LINE__;
+ }
+ else if (BUFFER_enlarge(ctrlPacket, topicLen + idLen + spaceLen) != 0)
+ {
+ result = __LINE__;
+ }
+ else
+ {
+ uint8_t* iterator = BUFFER_u_char(ctrlPacket);
+ if (iterator == NULL)
+ {
+ result = __LINE__;
+ }
+ else
+ {
+ iterator += currLen;
+ /* The Topic Name MUST be present as the first field in the PUBLISH Packet Variable header.It MUST be 792 a UTF-8 encoded string [MQTT-3.3.2-1] as defined in section 1.5.3.*/
+ byteutil_writeUTF(&iterator, publishHeader->topicName, (uint16_t)topicLen);
+ if (idLen > 0)
+ {
+ byteutil_writeInt(&iterator, publishHeader->packetId);
+ }
+ result = 0;
+ }
+ }
+ return result;
+}
+
+static int constructSubscibeTypeVariableHeader(BUFFER_HANDLE ctrlPacket, uint16_t packetId)
+{
+ int result = 0;
+ if (BUFFER_enlarge(ctrlPacket, 2) != 0)
+ {
+ result = __LINE__;
+ }
+ else
+ {
+ uint8_t* iterator = BUFFER_u_char(ctrlPacket);
+ if (iterator == NULL)
+ {
+ result = __LINE__;
+ }
+ else
+ {
+ byteutil_writeInt(&iterator, packetId);
+ result = 0;
+ }
+ }
+ return result;
+}
+
+static BUFFER_HANDLE constructPublishReply(CONTROL_PACKET_TYPE type, int flags, uint16_t packetId)
+{
+ BUFFER_HANDLE result = BUFFER_new();
+ if (result != NULL)
+ {
+ if (BUFFER_pre_build(result, 4) != 0)
+ {
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ else
+ {
+ uint8_t* iterator = BUFFER_u_char(result);
+ if (iterator == NULL)
+ {
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ else
+ {
+ *iterator = type | flags;
+ iterator++;
+ *iterator = 0x2;
+ iterator++;
+ byteutil_writeInt(&iterator, packetId);
+ }
+ }
+ }
+ return result;
+}
+
+static int constructFixedHeader(BUFFER_HANDLE ctrlPacket, CONTROL_PACKET_TYPE packetType, uint8_t flags)
+{
+ int result;
+ if (ctrlPacket == NULL)
+ {
+ return __LINE__;
+ }
+ else
+ {
+ size_t packetLen = BUFFER_length(ctrlPacket);
+ uint8_t remainSize[4] = { 0 };
+ size_t index = 0;
+
+ // Calculate the length of packet
+ do
+ {
+ uint8_t encode = packetLen % 128;
+ packetLen /= 128;
+ // if there are more data to encode, set the top bit of this byte
+ if (packetLen > 0)
+ {
+ encode |= NEXT_128_CHUNK;
+ }
+ remainSize[index++] = encode;
+ } while (packetLen > 0);
+
+ BUFFER_HANDLE fixedHeader = BUFFER_new();
+ if (fixedHeader == NULL)
+ {
+ result = __LINE__;
+ }
+ else if (BUFFER_pre_build(fixedHeader, index + 1) != 0)
+ {
+ BUFFER_delete(fixedHeader);
+ result = __LINE__;
+ }
+ else
+ {
+ uint8_t* iterator = BUFFER_u_char(fixedHeader);
+ *iterator = packetType | flags;
+ iterator++;
+ (void)memcpy(iterator, remainSize, index);
+
+ result = BUFFER_prepend(ctrlPacket, fixedHeader);
+ BUFFER_delete(fixedHeader);
+ }
+ }
+ return result;
+}
+
+static int constructConnPayload(BUFFER_HANDLE ctrlPacket, const MQTT_CLIENT_OPTIONS* mqttOptions)
+{
+ int result = 0;
+ if (mqttOptions == NULL || ctrlPacket == NULL)
+ {
+ result = __LINE__;
+ }
+ else
+ {
+ size_t clientLen = 0;
+ size_t usernameLen = 0;
+ size_t passwordLen = 0;
+ size_t willMessageLen = 0;
+ size_t willTopicLen = 0;
+ size_t spaceLen = 0;
+
+ if (mqttOptions->clientId != NULL)
+ {
+ spaceLen += 2;
+ clientLen = strlen(mqttOptions->clientId);
+ }
+ if (mqttOptions->username != NULL)
+ {
+ spaceLen += 2;
+ usernameLen = strlen(mqttOptions->username);
+ }
+ if (mqttOptions->password != NULL)
+ {
+ spaceLen += 2;
+ passwordLen = strlen(mqttOptions->password);
+ }
+ if (mqttOptions->willMessage != NULL)
+ {
+ spaceLen += 2;
+ willMessageLen = strlen(mqttOptions->willMessage);
+ }
+ if (mqttOptions->willTopic != NULL)
+ {
+ spaceLen += 2;
+ willTopicLen = strlen(mqttOptions->willTopic);
+ }
+
+ size_t currLen = BUFFER_length(ctrlPacket);
+ size_t totalLen = clientLen + usernameLen + passwordLen + willMessageLen + willTopicLen + spaceLen;
+
+ // Validate the Username & Password
+ if (clientLen > USHRT_MAX)
+ {
+ result = __LINE__;
+ }
+ else if (usernameLen > 0 && passwordLen == 0)
+ {
+ result = __LINE__;
+ }
+ else if ( (willMessageLen > 0 && willTopicLen == 0) || (willTopicLen > 0 && willMessageLen == 0) )
+ {
+ result = __LINE__;
+ }
+ else if (BUFFER_enlarge(ctrlPacket, totalLen) != 0)
+ {
+ result = __LINE__;
+ }
+ else
+ {
+ uint8_t* packet = BUFFER_u_char(ctrlPacket);
+ uint8_t* iterator = packet;
+
+ iterator += currLen;
+ byteutil_writeUTF(&iterator, mqttOptions->clientId, (uint16_t)clientLen);
+
+ // TODO: Read on the Will Topic
+ if (willMessageLen > USHRT_MAX || willTopicLen > USHRT_MAX || usernameLen > USHRT_MAX || passwordLen > USHRT_MAX)
+ {
+ result = __LINE__;
+ }
+ else
+ {
+ if (willMessageLen > 0 && willTopicLen > 0)
+ {
+ packet[CONN_FLAG_BYTE_OFFSET] |= WILL_FLAG_FLAG;
+ byteutil_writeUTF(&iterator, mqttOptions->willTopic, (uint16_t)willTopicLen);
+ packet[CONN_FLAG_BYTE_OFFSET] |= mqttOptions->qualityOfServiceValue;
+ if (mqttOptions->messageRetain)
+ {
+ packet[CONN_FLAG_BYTE_OFFSET] |= WILL_RETAIN_FLAG;
+ }
+ byteutil_writeUTF(&iterator, mqttOptions->willMessage, (uint16_t)willMessageLen);
+ }
+ if (usernameLen > 0)
+ {
+ packet[CONN_FLAG_BYTE_OFFSET] |= USERNAME_FLAG | PASSWORD_FLAG;
+ byteutil_writeUTF(&iterator, mqttOptions->username, (uint16_t)usernameLen);
+ byteutil_writeUTF(&iterator, mqttOptions->password, (uint16_t)passwordLen);
+ }
+ // TODO: Get the rest of the flags
+ if (mqttOptions->useCleanSession)
+ {
+ packet[CONN_FLAG_BYTE_OFFSET] |= CLEAN_SESSION_FLAG;
+ }
+ result = 0;
+ }
+ }
+ }
+ return result;
+}
+
+static int prepareheaderDataInfo(MQTTCODEC_INSTANCE* codecData, uint8_t remainLen)
+{
+ int result;
+ if (codecData == NULL)
+ {
+ result = __LINE__;
+ }
+ else
+ {
+ result = 0;
+ codecData->storeRemainLen[codecData->remainLenIndex++] = remainLen;
+ if (remainLen < 0x7f)
+ {
+ int multiplier = 1;
+ int totalLen = 0;
+ size_t index = 0;
+ uint8_t encodeByte = 0;
+ do
+ {
+ encodeByte = codecData->storeRemainLen[index++];
+ totalLen += (encodeByte & 127) * multiplier;
+ multiplier *= NEXT_128_CHUNK;
+
+ if (multiplier > 128 * 128 * 128)
+ {
+ result = __LINE__;
+ break;
+ }
+ } while ( (encodeByte & NEXT_128_CHUNK) != 0);
+
+ if (totalLen > 0)
+ {
+ codecData->headerData = BUFFER_new();
+ (void)BUFFER_pre_build(codecData->headerData, totalLen);
+ codecData->bufferOffset = 0;
+ }
+ codecData->codecState = CODEC_STATE_VAR_HEADER;
+
+ // Reset remainLen Index
+ codecData->remainLenIndex = 0;
+ memset(codecData->storeRemainLen, 0, 4 * sizeof(uint8_t));
+ }
+ }
+ return result;
+}
+
+static void completePacketData(MQTTCODEC_INSTANCE* codecData)
+{
+ if (codecData)
+ {
+ if (codecData->packetComplete != NULL)
+ {
+ codecData->packetComplete(codecData->callContext, codecData->currPacket, codecData->headerFlags, codecData->headerData);
+ }
+
+ // Clean up data
+ codecData->currPacket = UNKNOWN_TYPE;
+ codecData->codecState = CODEC_STATE_FIXED_HEADER;
+ codecData->headerFlags = 0;
+ BUFFER_delete(codecData->headerData);
+ codecData->headerData = NULL;
+ }
+}
+
+MQTTCODEC_HANDLE mqtt_codec_create(ON_PACKET_COMPLETE_CALLBACK packetComplete, void* callbackCtx)
+{
+ MQTTCODEC_HANDLE result;
+ result = malloc(sizeof(MQTTCODEC_INSTANCE) );
+ /* Codes_SRS_MQTT_CODEC_07_001: [If a failure is encountered then mqtt_codec_create shall return NULL.] */
+ if (result != NULL)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_002: [On success mqtt_codec_create shall return a MQTTCODEC_HANDLE value.] */
+ result->currPacket = UNKNOWN_TYPE;
+ result->codecState = CODEC_STATE_FIXED_HEADER;
+ result->headerFlags = 0;
+ result->bufferOffset = 0;
+ result->packetComplete = packetComplete;
+ result->callContext = callbackCtx;
+ result->headerData = NULL;
+ memset(result->storeRemainLen, 0, 4 * sizeof(uint8_t));
+ result->remainLenIndex = 0;
+ }
+ return result;
+}
+
+void mqtt_codec_destroy(MQTTCODEC_HANDLE handle)
+{
+ /* Codes_SRS_MQTT_CODEC_07_003: [If the handle parameter is NULL then mqtt_codec_destroy shall do nothing.] */
+ if (handle != NULL)
+ {
+ MQTTCODEC_INSTANCE* codecData = (MQTTCODEC_INSTANCE*)handle;
+ /* Codes_SRS_MQTT_CODEC_07_004: [mqtt_codec_destroy shall deallocate all memory that has been allocated by this object.] */
+ BUFFER_delete(codecData->headerData);
+ free(codecData);
+ }
+}
+
+BUFFER_HANDLE mqtt_codec_connect(const MQTT_CLIENT_OPTIONS* mqttOptions)
+{
+ BUFFER_HANDLE result;
+ /* Codes_SRS_MQTT_CODEC_07_008: [If the parameters mqttOptions is NULL then mqtt_codec_connect shall return a null value.] */
+ if (mqttOptions == NULL)
+ {
+ result = NULL;
+ }
+ else
+ {
+ /* Codes_SRS_MQTT_CODEC_07_009: [mqtt_codec_connect shall construct a BUFFER_HANDLE that represents a MQTT CONNECT packet.] */
+ result = BUFFER_new();
+ if (result != NULL)
+ {
+ // Add Variable Header Information
+ if (constructConnectVariableHeader(result, mqttOptions) != 0)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_010: [If any error is encountered then mqtt_codec_connect shall return NULL.] */
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ else
+ {
+ if (constructConnPayload(result, mqttOptions) != 0)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_010: [If any error is encountered then mqtt_codec_connect shall return NULL.] */
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ else
+ {
+ if (constructFixedHeader(result, CONNECT_TYPE, 0) != 0)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_010: [If any error is encountered then mqtt_codec_connect shall return NULL.] */
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ }
+ }
+ }
+ }
+ return result;
+}
+
+BUFFER_HANDLE mqtt_codec_disconnect()
+{
+ /* Codes_SRS_MQTT_CODEC_07_011: [On success mqtt_codec_disconnect shall construct a BUFFER_HANDLE that represents a MQTT DISCONNECT packet.] */
+ BUFFER_HANDLE result = BUFFER_new();
+ if (result != NULL)
+ {
+ if (BUFFER_enlarge(result, 2) != 0)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_012: [If any error is encountered mqtt_codec_disconnect shall return NULL.] */
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ else
+ {
+ uint8_t* iterator = BUFFER_u_char(result);
+ if (iterator == NULL)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_012: [If any error is encountered mqtt_codec_disconnect shall return NULL.] */
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ else
+ {
+ iterator[0] = DISCONNECT_TYPE;
+ iterator[1] = 0;
+ }
+ }
+ }
+ return result;
+}
+
+BUFFER_HANDLE mqtt_codec_publish(QOS_VALUE qosValue, bool duplicateMsg, bool serverRetain, uint16_t packetId, const char* topicName, const uint8_t* msgBuffer, size_t buffLen)
+{
+ BUFFER_HANDLE result;
+ /* Codes_SRS_MQTT_CODEC_07_005: [If the parameters topicName is NULL then mqtt_codec_publish shall return NULL.] */
+ if (topicName == NULL)
+ {
+ result = NULL;
+ }
+ /* Codes_SRS_MQTT_CODEC_07_036: [mqtt_codec_publish shall return NULL if the buffLen variable is greater than the MAX_SEND_SIZE (0xFFFFFF7F).] */
+ else if (buffLen > MAX_SEND_SIZE)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_006: [If any error is encountered then mqtt_codec_publish shall return NULL.] */
+ result = NULL;
+ }
+ else
+ {
+ PUBLISH_HEADER_INFO publishInfo = { 0 };
+ publishInfo.topicName = topicName;
+ publishInfo.packetId = packetId;
+ publishInfo.qualityOfServiceValue = qosValue;
+
+ uint8_t headerFlags = 0;
+ if (duplicateMsg) headerFlags |= PUBLISH_DUP_FLAG;
+ if (serverRetain) headerFlags |= PUBLISH_QOS_RETAIN;
+ if (qosValue != DELIVER_AT_MOST_ONCE)
+ {
+ if (qosValue == DELIVER_AT_LEAST_ONCE)
+ {
+ headerFlags |= PUBLISH_QOS_AT_LEAST_ONCE;
+ }
+ else
+ {
+ headerFlags |= PUBLISH_QOS_EXACTLY_ONCE;
+ }
+ }
+
+ /* Codes_SRS_MQTT_CODEC_07_007: [mqtt_codec_publish shall return a BUFFER_HANDLE that represents a MQTT PUBLISH message.] */
+ result = BUFFER_new();
+ if (result != NULL)
+ {
+ if (constructPublishVariableHeader(result, &publishInfo) != 0)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_006: [If any error is encountered then mqtt_codec_publish shall return NULL.] */
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ else
+ {
+ size_t payloadOffset = BUFFER_length(result);
+ if (buffLen > 0)
+ {
+ if (BUFFER_enlarge(result, buffLen) != 0)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_006: [If any error is encountered then mqtt_codec_publish shall return NULL.] */
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ else
+ {
+ uint8_t* iterator = BUFFER_u_char(result);
+ if (iterator == NULL)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_006: [If any error is encountered then mqtt_codec_publish shall return NULL.] */
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ else
+ {
+ iterator += payloadOffset;
+ // Write Message
+ memcpy(iterator, msgBuffer, buffLen);
+ }
+ }
+ }
+
+ if (result != NULL)
+ {
+ if (constructFixedHeader(result, PUBLISH_TYPE, headerFlags) != 0)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_006: [If any error is encountered then mqtt_codec_publish shall return NULL.] */
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ }
+ }
+ }
+ }
+ return result;
+}
+
+BUFFER_HANDLE mqtt_codec_publishAck(uint16_t packetId)
+{
+ /* Codes_SRS_MQTT_CODEC_07_013: [On success mqtt_codec_publishAck shall return a BUFFER_HANDLE representation of a MQTT PUBACK packet.] */
+ /* Codes_SRS_MQTT_CODEC_07_014 : [If any error is encountered then mqtt_codec_publishAck shall return NULL.] */
+ BUFFER_HANDLE result = constructPublishReply(PUBACK_TYPE, 0, packetId);
+ return result;
+}
+
+BUFFER_HANDLE mqtt_codec_publishReceived(uint16_t packetId)
+{
+ /* Codes_SRS_MQTT_CODEC_07_015: [On success mqtt_codec_publishRecieved shall return a BUFFER_HANDLE representation of a MQTT PUBREC packet.] */
+ /* Codes_SRS_MQTT_CODEC_07_016 : [If any error is encountered then mqtt_codec_publishRecieved shall return NULL.] */
+ BUFFER_HANDLE result = constructPublishReply(PUBREC_TYPE, 0, packetId);
+ return result;
+}
+
+BUFFER_HANDLE mqtt_codec_publishRelease(uint16_t packetId)
+{
+ /* Codes_SRS_MQTT_CODEC_07_017: [On success mqtt_codec_publishRelease shall return a BUFFER_HANDLE representation of a MQTT PUBREL packet.] */
+ /* Codes_SRS_MQTT_CODEC_07_018 : [If any error is encountered then mqtt_codec_publishRelease shall return NULL.] */
+ BUFFER_HANDLE result = constructPublishReply(PUBREL_TYPE, 2, packetId);
+ return result;
+}
+
+BUFFER_HANDLE mqtt_codec_publishComplete(uint16_t packetId)
+{
+ /* Codes_SRS_MQTT_CODEC_07_019: [On success mqtt_codec_publishComplete shall return a BUFFER_HANDLE representation of a MQTT PUBCOMP packet.] */
+ /* Codes_SRS_MQTT_CODEC_07_020 : [If any error is encountered then mqtt_codec_publishComplete shall return NULL.] */
+ BUFFER_HANDLE result = constructPublishReply(PUBCOMP_TYPE, 0, packetId);
+ return result;
+}
+
+BUFFER_HANDLE mqtt_codec_ping()
+{
+ /* Codes_SRS_MQTT_CODEC_07_021: [On success mqtt_codec_ping shall construct a BUFFER_HANDLE that represents a MQTT PINGREQ packet.] */
+ BUFFER_HANDLE result = BUFFER_new();
+ if (result != NULL)
+ {
+ if (BUFFER_enlarge(result, 2) != 0)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_022: [If any error is encountered mqtt_codec_ping shall return NULL.] */
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ else
+ {
+ uint8_t* iterator = BUFFER_u_char(result);
+ if (iterator == NULL)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_022: [If any error is encountered mqtt_codec_ping shall return NULL.] */
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ else
+ {
+ iterator[0] = PINGREQ_TYPE;
+ iterator[1] = 0;
+ }
+ }
+ }
+ return result;
+}
+
+BUFFER_HANDLE mqtt_codec_subscribe(uint16_t packetId, SUBSCRIBE_PAYLOAD* subscribeList, size_t count)
+{
+ BUFFER_HANDLE result;
+ /* Codes_SRS_MQTT_CODEC_07_023: [If the parameters subscribeList is NULL or if count is 0 then mqtt_codec_subscribe shall return NULL.] */
+ if (subscribeList == NULL || count == 0)
+ {
+ result = NULL;
+ }
+ else
+ {
+ /* Codes_SRS_MQTT_CODEC_07_026: [mqtt_codec_subscribe shall return a BUFFER_HANDLE that represents a MQTT SUBSCRIBE message.]*/
+ result = BUFFER_new();
+ if (result != NULL)
+ {
+ if (constructSubscibeTypeVariableHeader(result, packetId) != 0)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_025: [If any error is encountered then mqtt_codec_subscribe shall return NULL.] */
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ else
+ {
+ /* Codes_SRS_MQTT_CODEC_07_024: [mqtt_codec_subscribe shall iterate through count items in the subscribeList.] */
+ if (addListItemsToSubscribePacket(result, subscribeList, count) != 0)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_025: [If any error is encountered then mqtt_codec_subscribe shall return NULL.] */
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ else
+ {
+ if (constructFixedHeader(result, SUBSCRIBE_TYPE, SUBSCRIBE_FIXED_HEADER_FLAG) != 0)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_025: [If any error is encountered then mqtt_codec_subscribe shall return NULL.] */
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ }
+ }
+ }
+ }
+ return result;
+}
+
+BUFFER_HANDLE mqtt_codec_unsubscribe(uint16_t packetId, const char** unsubscribeList, size_t count)
+{
+ BUFFER_HANDLE result;
+ /* Codes_SRS_MQTT_CODEC_07_027: [If the parameters unsubscribeList is NULL or if count is 0 then mqtt_codec_unsubscribe shall return NULL.] */
+ if (unsubscribeList == NULL || count == 0)
+ {
+ result = NULL;
+ }
+ else
+ {
+ /* Codes_SRS_MQTT_CODEC_07_030: [mqtt_codec_unsubscribe shall return a BUFFER_HANDLE that represents a MQTT SUBSCRIBE message.] */
+ result = BUFFER_new();
+ if (result != NULL)
+ {
+ if (constructSubscibeTypeVariableHeader(result, packetId) != 0)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_029: [If any error is encountered then mqtt_codec_unsubscribe shall return NULL.] */
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ else
+ {
+ /* Codes_SRS_MQTT_CODEC_07_028: [mqtt_codec_unsubscribe shall iterate through count items in the unsubscribeList.] */
+ if (addListItemsToUnsubscribePacket(result, unsubscribeList, count) != 0)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_029: [If any error is encountered then mqtt_codec_unsubscribe shall return NULL.] */
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ else
+ {
+ if (constructFixedHeader(result, UNSUBSCRIBE_TYPE, UNSUBSCRIBE_FIXED_HEADER_FLAG) != 0)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_029: [If any error is encountered then mqtt_codec_unsubscribe shall return NULL.] */
+ BUFFER_delete(result);
+ result = NULL;
+ }
+ }
+ }
+ }
+ }
+ return result;
+}
+
+int mqtt_codec_bytesReceived(MQTTCODEC_HANDLE handle, const unsigned char* buffer, size_t size)
+{
+ int result;
+ MQTTCODEC_INSTANCE* codec_Data = (MQTTCODEC_INSTANCE*)handle;
+ /* Codes_SRS_MQTT_CODEC_07_031: [If the parameters handle or buffer is NULL then mqtt_codec_bytesReceived shall return a non-zero value.] */
+ if (codec_Data == NULL)
+ {
+ result = __LINE__;
+ }
+ /* Codes_SRS_MQTT_CODEC_07_031: [If the parameters handle or buffer is NULL then mqtt_codec_bytesReceived shall return a non-zero value.] */
+ /* Codes_SRS_MQTT_CODEC_07_032: [If the parameters size is zero then mqtt_codec_bytesReceived shall return a non-zero value.] */
+ else if (buffer == NULL || size == 0)
+ {
+ codec_Data->currPacket = PACKET_TYPE_ERROR;
+ result = __LINE__;
+ }
+ else
+ {
+ /* Codes_SRS_MQTT_CODEC_07_033: [mqtt_codec_bytesReceived constructs a sequence of bytes into the corresponding MQTT packets and on success returns zero.] */
+ result = 0;
+ for (size_t index = 0; index < size && result == 0; index++)
+ {
+ uint8_t iterator = ((int8_t*)buffer)[index];
+ if (codec_Data->codecState == CODEC_STATE_FIXED_HEADER)
+ {
+ if (codec_Data->currPacket == UNKNOWN_TYPE)
+ {
+ codec_Data->currPacket = processControlPacketType(iterator, &codec_Data->headerFlags);
+ }
+ else
+ {
+ if (prepareheaderDataInfo(codec_Data, iterator) != 0)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_035: [If any error is encountered then the packet state will be marked as error and mqtt_codec_bytesReceived shall return a non-zero value.] */
+ codec_Data->currPacket = PACKET_TYPE_ERROR;
+ result = __LINE__;
+ }
+ if (codec_Data->currPacket == PINGRESP_TYPE)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_034: [Upon a constructing a complete MQTT packet mqtt_codec_bytesReceived shall call the ON_PACKET_COMPLETE_CALLBACK function.] */
+ completePacketData(codec_Data);
+ }
+ }
+ }
+ else if (codec_Data->codecState == CODEC_STATE_VAR_HEADER)
+ {
+ size_t payloadLen = 0;
+ if (codec_Data->headerData == NULL)
+ {
+ codec_Data->codecState = CODEC_STATE_PAYLOAD;
+ }
+ else
+ {
+ uint8_t* dataBytes = BUFFER_u_char(codec_Data->headerData);
+ if (dataBytes == NULL)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_035: [If any error is encountered then the packet state will be marked as error and mqtt_codec_bytesReceived shall return a non-zero value.] */
+ codec_Data->currPacket = PACKET_TYPE_ERROR;
+ result = __LINE__;
+ }
+ else
+ {
+ // Increment the data
+ dataBytes += codec_Data->bufferOffset++;
+ *dataBytes = iterator;
+
+ size_t totalLen = BUFFER_length(codec_Data->headerData);
+ if (codec_Data->bufferOffset >= totalLen)
+ {
+ /* Codes_SRS_MQTT_CODEC_07_034: [Upon a constructing a complete MQTT packet mqtt_codec_bytesReceived shall call the ON_PACKET_COMPLETE_CALLBACK function.] */
+ completePacketData(codec_Data);
+ }
+ }
+ }
+ }
+ else
+ {
+ /* Codes_SRS_MQTT_CODEC_07_035: [If any error is encountered then the packet state will be marked as error and mqtt_codec_bytesReceived shall return a non-zero value.] */
+ codec_Data->currPacket = PACKET_TYPE_ERROR;
+ result = __LINE__;
+ }
+ }
+ }
+ return result;
+}
