iothub_device_sample.c

// Copyright (c) Microsoft. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.

/*
CAUTION: Checking of return codes and error values shall be omitted for brevity in this sample.
This sample is to demonstrate azure IoT client concepts only and is not a guide design principles or style.
Please practice sound engineering practices when writing production code.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "iothub.h"
#include "iothub_device_client.h"
#include "iothub_client_options.h"
#include "iothub_message.h"
#include "azure_c_shared_utility/threadapi.h"
#include "azure_c_shared_utility/crt_abstractions.h"
#include "azure_c_shared_utility/platform.h"
#include "azure_c_shared_utility/shared_util_options.h"
#include "azure_c_shared_utility/tickcounter.h"

/*
This sample uses the multithreaded APIs of iothub_client for example purposes.
The difference between multithreaded and singlethreaded (_ll_) API?
Multithreaded creates a separate thread to perform DoWork calls, which are necessary
for the device client library to do anything. The benefit of using the
multithreaded API is that the calls to DoWork are abstracted away from your code.
*/


// The protocol you wish to use should be uncommented
//
#define SAMPLE_MQTT
//#define SAMPLE_MQTT_OVER_WEBSOCKETS
//#define SAMPLE_AMQP
//#define SAMPLE_AMQP_OVER_WEBSOCKETS
//#define SAMPLE_HTTP

#ifdef SAMPLE_MQTT
    #include "iothubtransportmqtt.h"
#endif // SAMPLE_MQTT
#ifdef SAMPLE_MQTT_OVER_WEBSOCKETS
    #include "iothubtransportmqtt_websockets.h"
#endif // SAMPLE_MQTT_OVER_WEBSOCKETS
#ifdef SAMPLE_AMQP
    #include "iothubtransportamqp.h"
#endif // SAMPLE_AMQP
#ifdef SAMPLE_AMQP_OVER_WEBSOCKETS
    #include "iothubtransportamqp_websockets.h"
#endif // SAMPLE_AMQP_OVER_WEBSOCKETS
#ifdef SAMPLE_HTTP
    #include "iothubtransporthttp.h"
#endif // SAMPLE_HTTP

#ifdef SET_TRUSTED_CERT_IN_SAMPLES
#include "certs.h"
#endif // SET_TRUSTED_CERT_IN_SAMPLES

/* Paste in your device connection string  */
static const char* connectionString = "[device connection string]";

static bool g_continueRunning = true;
int g_interval = 10000;  // 10 sec send interval initially
static size_t g_message_count_send_confirmations = 0;

static const char* proxy_host = NULL;    // "Web proxy name here"
static int proxy_port = 0;               // Proxy port
static const char* proxy_username = NULL; // Proxy user name
static const char* proxy_password = NULL; // Proxy password

// names of optional custom properties that may be specified by the service to C2D messages
const char* applicationCustomPropertyKey1 = "appCustomProperty1";
const char* applicationCustomPropertyKey2 = "appCustomProperty2";

// The Azure IoT C SDK allows developers to acknowledge cloud-to-device messages
// (either sending DISPOSITION if using AMQP, or PUBACK if using MQTT) outside the following callback, in a separate function call.
// This would allow the user application to process the incoming message before acknowledging it to the Azure IoT Hub, since
// the callback below is supposed to return as fast as possible to unblock I/O.
// Please look for "IOTHUBMESSAGE_ASYNC_ACK" in iothub_ll_c2d_sample for more details.
static IOTHUBMESSAGE_DISPOSITION_RESULT receive_msg_callback(IOTHUB_MESSAGE_HANDLE message, void* user_context)
{
    (void)user_context;
    const char* messageId;
    const char* correlationId;
    const char* contentType;
    const char* contentEncoding;
    const char* messageCreationTimeUtc;
    const char* messageUserId;

    const char* applicationCustomPropertyValue1;
    const char* applicationCustomPropertyValue2;

    // Message properties
    if ((messageId = IoTHubMessage_GetMessageId(message)) == NULL)
    {
        messageId = "<unavailable>";
    }

    if ((correlationId = IoTHubMessage_GetCorrelationId(message)) == NULL)
    {
        correlationId = "<unavailable>";
    }

    if ((contentType = IoTHubMessage_GetContentTypeSystemProperty(message)) == NULL)
    {
        contentType = "<unavailable>";
    }

    if ((contentEncoding = IoTHubMessage_GetContentEncodingSystemProperty(message)) == NULL)
    {
        contentEncoding = "<unavailable>";
    }

    if ((messageCreationTimeUtc = IoTHubMessage_GetMessageCreationTimeUtcSystemProperty(message)) == NULL)
    {
        messageCreationTimeUtc = "<unavailable>";
    }

    if ((messageUserId = IoTHubMessage_GetMessageUserIdSystemProperty(message)) == NULL)
    {
        messageUserId = "<unavailable>";
    }

    if ((applicationCustomPropertyValue1 = IoTHubMessage_GetProperty(message, applicationCustomPropertyKey1)) == NULL)
    {
        applicationCustomPropertyValue1 = "<unavailable>";
    }

    if ((applicationCustomPropertyValue2 = IoTHubMessage_GetProperty(message, applicationCustomPropertyKey2)) == NULL)
    {
        applicationCustomPropertyValue2 = "<unavailable>";
    }

    IOTHUBMESSAGE_CONTENT_TYPE content_type = IoTHubMessage_GetContentType(message);
    if (content_type == IOTHUBMESSAGE_BYTEARRAY)
    {
        const unsigned char* buff_msg;
        size_t buff_len;

        if (IoTHubMessage_GetByteArray(message, &buff_msg, &buff_len) != IOTHUB_MESSAGE_OK)
        {
            (void)printf("Failure retrieving byte array message\r\n");
        }
        else
        {
            (void)printf("Received Binary message.\r\n  Data: <<<%.*s>>> & Size=%d\r\n", (int)buff_len, buff_msg, (int)buff_len);
        }
    }
    else
    {
        const char* string_msg = IoTHubMessage_GetString(message);
        if (string_msg == NULL)
        {
            (void)printf("Failure retrieving byte array message\r\n");
        }
        else
        {
            (void)printf("Received String Message.\r\n  Data: <<<%s>>>\r\n", string_msg);
        }
    }

    printf("Message properties:\r\n  Message ID: %s\r\n  Correlation ID: %s\r\n  ContentType: %s\r\n  ContentEncoding: %s\r\n"
           "  messageCreationTimeUtc: %s\r\n  messageUserId: %s\r\n  %s: %s\r\n  %s: %s\r\n",
           messageId, correlationId, contentType, contentEncoding, messageCreationTimeUtc, messageUserId,
           applicationCustomPropertyKey1, applicationCustomPropertyValue1 ,applicationCustomPropertyKey2, applicationCustomPropertyValue2);

    return IOTHUBMESSAGE_ACCEPTED;
}


static int device_method_callback(const char* method_name, const unsigned char* payload, size_t size, unsigned char** response, size_t* resp_size, void* userContextCallback)
{
    const char* SetTelemetryIntervalMethod = "SetTelemetryInterval";
    const char* device_id = (const char*)userContextCallback;
    char* end = NULL;
    int newInterval;

    int status = 501;
    const char* RESPONSE_STRING = "{ \"Response\": \"Unknown method requested.\" }";

    (void)printf("\r\nDevice Method called for device %s\r\n", device_id);
    (void)printf("Device Method name:    %s\r\n", method_name);
    (void)printf("Device Method payload: %.*s\r\n", (int)size, (const char*)payload);

    if (strcmp(method_name, SetTelemetryIntervalMethod) == 0)
    {
        if (payload)
        {
            newInterval = (int)strtol((char*)payload, &end, 10);

            // Interval must be greater than zero.
            if (newInterval > 0)
            {
                // expect sec and covert to ms
                g_interval = 1000 * (int)strtol((char*)payload, &end, 10);
                status = 200;
                RESPONSE_STRING = "{ \"Response\": \"Telemetry reporting interval updated.\" }";
            }
            else
            {
                status = 500;
                RESPONSE_STRING = "{ \"Response\": \"Invalid telemetry reporting interval.\" }";
            }
        }
    }

    (void)printf("\r\nResponse status: %d\r\n", status);
    (void)printf("Response payload: %s\r\n\r\n", RESPONSE_STRING);

    *resp_size = strlen(RESPONSE_STRING);
    if ((*response = malloc(*resp_size)) == NULL)
    {
        status = -1;
    }
    else
    {
        memcpy(*response, RESPONSE_STRING, *resp_size);
    }

    return status;
}


static void connection_status_callback(IOTHUB_CLIENT_CONNECTION_STATUS result, IOTHUB_CLIENT_CONNECTION_STATUS_REASON reason, void* user_context)
{
    (void)reason;
    (void)user_context;
    // This sample DOES NOT take into consideration network outages.
    if (result == IOTHUB_CLIENT_CONNECTION_AUTHENTICATED)
    {
        (void)printf("The device client is connected to iothub\r\n");
    }
    else
    {
        (void)printf("The device client has been disconnected\r\n");
    }
}

static void send_confirm_callback(IOTHUB_CLIENT_CONFIRMATION_RESULT result, void* userContextCallback)
{
    (void)userContextCallback;
    // When a message is sent this callback will get invoked
    g_message_count_send_confirmations++;
    (void)printf("Confirmation callback received for message %lu with result %s\r\n", (unsigned long)g_message_count_send_confirmations, MU_ENUM_TO_STRING(IOTHUB_CLIENT_CONFIRMATION_RESULT, result));
}


int main(void)
{
    IOTHUB_CLIENT_TRANSPORT_PROVIDER protocol;

    IOTHUB_MESSAGE_HANDLE message_handle;
    float telemetry_temperature;
    float telemetry_humidity;
    const char* telemetry_scale = "Celsius";
    char telemetry_msg_buffer[80];

    int messagecount = 0;

    printf("\r\nThis sample will send messages continuously and accept C2D messages.\r\nPress Ctrl+C to terminate the sample.\r\n\r\n");

    // Select the Protocol to use with the connection
#ifdef SAMPLE_MQTT
    protocol = MQTT_Protocol;
#endif // SAMPLE_MQTT
#ifdef SAMPLE_MQTT_OVER_WEBSOCKETS
    protocol = MQTT_WebSocket_Protocol;
#endif // SAMPLE_MQTT_OVER_WEBSOCKETS
#ifdef SAMPLE_AMQP
    protocol = AMQP_Protocol;
#endif // SAMPLE_AMQP
#ifdef SAMPLE_AMQP_OVER_WEBSOCKETS
    protocol = AMQP_Protocol_over_WebSocketsTls;
#endif // SAMPLE_AMQP_OVER_WEBSOCKETS
#ifdef SAMPLE_HTTP
    protocol = HTTP_Protocol;
#endif // SAMPLE_HTTP

    IOTHUB_DEVICE_CLIENT_HANDLE device_handle;

    // Used to initialize IoTHub SDK subsystem
    (void)IoTHub_Init();

    (void)printf("Creating IoTHub handle\r\n");
    // Create the iothub handle here
    device_handle = IoTHubDeviceClient_CreateFromConnectionString(connectionString, protocol);
    if (device_handle == NULL)
    {
        (void)printf("Failure creating IotHub device. Hint: Check your connection string.\r\n");
    }
    else
    {
        if (proxy_host)
        {
            HTTP_PROXY_OPTIONS http_proxy_options = { 0 };
            http_proxy_options.host_address = proxy_host;
            http_proxy_options.port = proxy_port;
            http_proxy_options.username = proxy_username;
            http_proxy_options.password = proxy_password;

            if (IoTHubDeviceClient_SetOption(device_handle, OPTION_HTTP_PROXY, &http_proxy_options) != IOTHUB_CLIENT_OK)
            {
                (void)printf("failure to set proxy\n");
            }
        }

        // Setting message callback to get C2D messages
        (void)IoTHubDeviceClient_SetMessageCallback(device_handle, receive_msg_callback, NULL);
        // Setting method callback to handle a SetTelemetryInterval method to control
        //   how often telemetry messages are sent from the simulated device.
        (void)IoTHubDeviceClient_SetDeviceMethodCallback(device_handle, device_method_callback, NULL);
        // Setting connection status callback to get indication of connection to iothub
        (void)IoTHubDeviceClient_SetConnectionStatusCallback(device_handle, connection_status_callback, NULL);

        // Set any option that are necessary.
        // For available options please see the iothub_sdk_options.md documentation

        // Setting Log Tracing.
        // Log tracing is supported in MQTT and AMQP. Not HTTP.
#ifndef SAMPLE_HTTP
        bool traceOn = true;
        (void)IoTHubDeviceClient_SetOption(device_handle, OPTION_LOG_TRACE, &traceOn);
#endif

        // Setting the frequency of DoWork calls by the underlying process thread.
        // The value ms_delay is a delay between DoWork calls, in milliseconds.
        // ms_delay can only be between 1 and 100 milliseconds.
        // Without the SetOption, the delay defaults to 1 ms.
        tickcounter_ms_t ms_delay = 10;
        (void)IoTHubDeviceClient_SetOption(device_handle, OPTION_DO_WORK_FREQUENCY_IN_MS, &ms_delay);

#ifdef SET_TRUSTED_CERT_IN_SAMPLES
        // Setting the Trusted Certificate. This is only necessary on systems without
        // built in certificate stores.
        (void)IoTHubDeviceClient_SetOption(device_handle, OPTION_TRUSTED_CERT, certificates);
#endif // SET_TRUSTED_CERT_IN_SAMPLES

#if defined SAMPLE_MQTT || defined SAMPLE_MQTT_OVER_WEBSOCKETS
        //Setting the auto URL Encoder (recommended for MQTT). Please use this option unless
        //you are URL Encoding inputs yourself.
        //ONLY valid for use with MQTT
        bool urlEncodeOn = true;
        (void)IoTHubDeviceClient_SetOption(device_handle, OPTION_AUTO_URL_ENCODE_DECODE, &urlEncodeOn);
#endif

        while(g_continueRunning)
        {
            // Construct the iothub message
            telemetry_temperature = 20.0f + ((float)rand() / (float)RAND_MAX) * 15.0f;
            telemetry_humidity = 60.0f + ((float)rand() / (float)RAND_MAX) * 20.0f;

            sprintf(telemetry_msg_buffer, "{\"temperature\":%.3f,\"humidity\":%.3f,\"scale\":\"%s\"}",
                telemetry_temperature, telemetry_humidity, telemetry_scale);

            message_handle = IoTHubMessage_CreateFromString(telemetry_msg_buffer);

            // Set Message property
            (void)IoTHubMessage_SetMessageId(message_handle, "MSG_ID");
            (void)IoTHubMessage_SetCorrelationId(message_handle, "CORE_ID");
            (void)IoTHubMessage_SetContentTypeSystemProperty(message_handle, "application%2fjson");
            (void)IoTHubMessage_SetContentEncodingSystemProperty(message_handle, "utf-8");

            // Add custom properties to message
            (void)IoTHubMessage_SetProperty(message_handle, "property_key", "property_value");

            (void)printf("\r\nSending message %d to IoTHub\r\nMessage: %s\r\n", (int)(messagecount + 1), telemetry_msg_buffer);
            IoTHubDeviceClient_SendEventAsync(device_handle, message_handle, send_confirm_callback, NULL);

            // The message is copied to the sdk so the we can destroy it
            IoTHubMessage_Destroy(message_handle);
            messagecount = messagecount + 1;

            ThreadAPI_Sleep(g_interval);
        }

        // Clean up the iothub sdk handle
        IoTHubDeviceClient_Destroy(device_handle);
    }
    // Free all the sdk subsystem
    IoTHub_Deinit();

    return 0;
}