git.sur5r.net Git - freertos/blob - FreeRTOS-Labs/Source/FreeRTOS-IoT-Libraries/c_sdk/aws/common/src/aws_iot_subscription.c

   1 /*\r
   2  * AWS IoT Common V1.0.0\r
   3  * Copyright (C) 2019 Amazon.com, Inc. or its affiliates.  All Rights Reserved.\r
   4  *\r
   5  * Permission is hereby granted, free of charge, to any person obtaining a copy of\r
   6  * this software and associated documentation files (the "Software"), to deal in\r
   7  * the Software without restriction, including without limitation the rights to\r
   8  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of\r
   9  * the Software, and to permit persons to whom the Software is furnished to do so,\r
  10  * subject to the following conditions:\r
  11  *\r
  12  * The above copyright notice and this permission notice shall be included in all\r
  13  * copies or substantial portions of the Software.\r
  14  *\r
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR\r
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS\r
  17  * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR\r
  18  * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER\r
  19  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN\r
  20  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.\r
  21  */\r
  22 \r
  23 /**\r
  24  * @file aws_iot_subscription.c\r
  25  * @brief Functions for common AWS IoT subscriptions.\r
  26  */\r
  27 \r
  28 /* The config header is always included first. */\r
  29 #include "iot_config.h"\r
  30 \r
  31 /* Standard includes. */\r
  32 #include <string.h>\r
  33 \r
  34 /* AWS IoT include. */\r
  35 #include "aws_iot.h"\r
  36 \r
  37 /* Error handling include. */\r
  38 #include "iot_error.h"\r
  39 \r
  40 /* MQTT include. */\r
  41 #include "iot_mqtt.h"\r
  42 \r
  43 /**\r
  44  * @brief Modify subscriptions, either by unsubscribing or subscribing.\r
  45  *\r
  46  * @param[in] mqttOperation Either @ref mqtt_function_subscribesync or @ref\r
  47  * mqtt_function_unsubscribesync.\r
  48  * @param[in] pSubscriptionInfo Information needed to process an MQTT\r
  49  * operation.\r
  50  * @param[in] pTopicFilter The topic filter to modify.\r
  51  * @param[in] topicFilterLength The length of `pTopicFilter`.\r
  52  *\r
  53  * @return See the return values of @ref mqtt_function_subscribesync or\r
  54  * @ref mqtt_function_unsubscribesync.\r
  55  */\r
  56 static IotMqttError_t _modifySubscriptions( AwsIotMqttFunction_t mqttOperation,\r
  57                                             const AwsIotSubscriptionInfo_t * pSubscriptionInfo,\r
  58                                             const char * pTopicFilter,\r
  59                                             uint16_t topicFilterLength );\r
  60 \r
  61 /*-----------------------------------------------------------*/\r
  62 \r
  63 static IotMqttError_t _modifySubscriptions( AwsIotMqttFunction_t mqttOperation,\r
  64                                             const AwsIotSubscriptionInfo_t * pSubscriptionInfo,\r
  65                                             const char * pTopicFilter,\r
  66                                             uint16_t topicFilterLength )\r
  67 {\r
  68     IotMqttError_t status = IOT_MQTT_STATUS_PENDING;\r
  69     IotMqttSubscription_t subscription = IOT_MQTT_SUBSCRIPTION_INITIALIZER;\r
  70 \r
  71     /* Per the AWS IoT documentation, topic subscriptions are QoS 1. */\r
  72     subscription.qos = IOT_MQTT_QOS_1;\r
  73 \r
  74     /* Set the members of the subscription parameter. */\r
  75     subscription.pTopicFilter = pTopicFilter;\r
  76     subscription.topicFilterLength = topicFilterLength;\r
  77     subscription.callback.pCallbackContext = NULL;\r
  78     subscription.callback.function = pSubscriptionInfo->callbackFunction;\r
  79 \r
  80     /* Call the MQTT operation function.\r
  81      * Subscription count is 1 in this case.\r
  82      * None of the flags are set in this call. Hence 0 is passed for flags.\r
  83      * Please refer to documentation for AwsIotMqttFunction_t for more details.\r
  84      */\r
  85     status = mqttOperation( pSubscriptionInfo->mqttConnection,\r
  86                             &subscription,\r
  87                             1,\r
  88                             0,\r
  89                             pSubscriptionInfo->timeout );\r
  90 \r
  91     return status;\r
  92 }\r
  93 \r
  94 /*-----------------------------------------------------------*/\r
  95 \r
  96 IotMqttError_t AwsIot_ModifySubscriptions( AwsIotMqttFunction_t mqttOperation,\r
  97                                            const AwsIotSubscriptionInfo_t * pSubscriptionInfo )\r
  98 {\r
  99     IOT_FUNCTION_ENTRY( IotMqttError_t, IOT_MQTT_STATUS_PENDING );\r
 100     IotMqttError_t acceptedStatus = IOT_MQTT_STATUS_PENDING;\r
 101     uint16_t topicFilterLength = 0;\r
 102 \r
 103     /* Place the topic "accepted" suffix at the end of the topic buffer. */\r
 104     ( void ) memcpy( pSubscriptionInfo->pTopicFilterBase\r
 105                      + pSubscriptionInfo->topicFilterBaseLength,\r
 106                      AWS_IOT_ACCEPTED_SUFFIX,\r
 107                      AWS_IOT_ACCEPTED_SUFFIX_LENGTH );\r
 108     topicFilterLength = ( uint16_t ) ( pSubscriptionInfo->topicFilterBaseLength\r
 109                                        + AWS_IOT_ACCEPTED_SUFFIX_LENGTH );\r
 110 \r
 111     /* Modify the subscription to the "accepted" topic. */\r
 112     acceptedStatus = _modifySubscriptions( mqttOperation,\r
 113                                            pSubscriptionInfo,\r
 114                                            pSubscriptionInfo->pTopicFilterBase,\r
 115                                            topicFilterLength );\r
 116 \r
 117     if( acceptedStatus != IOT_MQTT_SUCCESS )\r
 118     {\r
 119         IOT_SET_AND_GOTO_CLEANUP( acceptedStatus );\r
 120     }\r
 121 \r
 122     /* Place the topic "rejected" suffix at the end of the topic buffer. */\r
 123     ( void ) memcpy( pSubscriptionInfo->pTopicFilterBase\r
 124                      + pSubscriptionInfo->topicFilterBaseLength,\r
 125                      AWS_IOT_REJECTED_SUFFIX,\r
 126                      AWS_IOT_REJECTED_SUFFIX_LENGTH );\r
 127     topicFilterLength = ( uint16_t ) ( pSubscriptionInfo->topicFilterBaseLength\r
 128                                        + AWS_IOT_REJECTED_SUFFIX_LENGTH );\r
 129 \r
 130     /* Modify the subscription to the "rejected" topic. */\r
 131     status = _modifySubscriptions( mqttOperation,\r
 132                                    pSubscriptionInfo,\r
 133                                    pSubscriptionInfo->pTopicFilterBase,\r
 134                                    topicFilterLength );\r
 135 \r
 136     IOT_FUNCTION_CLEANUP_BEGIN();\r
 137 \r
 138     /* Clean up on error. */\r
 139     if( status != IOT_MQTT_SUCCESS )\r
 140     {\r
 141         /* Remove the subscription to the "accepted" topic if the subscription\r
 142          * to the "rejected" topic failed. */\r
 143         if( ( mqttOperation == IotMqtt_SubscribeSync ) &&\r
 144             ( acceptedStatus == IOT_MQTT_SUCCESS ) )\r
 145         {\r
 146             /* Place the topic "accepted" suffix at the end of the topic buffer. */\r
 147             ( void ) memcpy( pSubscriptionInfo->pTopicFilterBase\r
 148                              + pSubscriptionInfo->topicFilterBaseLength,\r
 149                              AWS_IOT_ACCEPTED_SUFFIX,\r
 150                              AWS_IOT_ACCEPTED_SUFFIX_LENGTH );\r
 151             topicFilterLength = ( uint16_t ) ( pSubscriptionInfo->topicFilterBaseLength\r
 152                                                + AWS_IOT_ACCEPTED_SUFFIX_LENGTH );\r
 153 \r
 154             ( void ) _modifySubscriptions( IotMqtt_UnsubscribeSync,\r
 155                                            pSubscriptionInfo,\r
 156                                            pSubscriptionInfo->pTopicFilterBase,\r
 157                                            topicFilterLength );\r
 158         }\r
 159     }\r
 160 \r
 161     IOT_FUNCTION_CLEANUP_END();\r
 162 }\r
 163 \r
 164 /*-----------------------------------------------------------*/\r