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