A small footprint MQTT library
Dependents: STM32F746_iothub_client_sample_mqtt FXOS8700CQ_To_Azure_IoT f767zi_mqtt FXOS8700CQ_To_Azure_IoT ... more
mqtt_codec.c
- Committer:
- AzureIoTClient
- Date:
- 2016-07-29
- Revision:
- 5:34779607059c
- Parent:
- 0:ef4901974abc
- Child:
- 8:83bb166aba73
File content as of revision 5:34779607059c:
// 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, uint8_t 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 = (uint8_t)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 = (uint8_t)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; byteutil_writeUTF(&iterator, mqttOptions->username, (uint16_t)usernameLen); } if (passwordLen > 0) { packet[CONN_FLAG_BYTE_OFFSET] |= PASSWORD_FLAG; 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) { 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; }