File content as of revision 0:f86732d81998:

/*******************************************************************************
 * Copyright (c) 2015 IBM Corp.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v1.0 which accompany this distribution.
 *
 * The Eclipse Public License is available at
 *    http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 *   http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *    Sathisumar Palaniappan - initial implementation
 *
 *******************************************************************************/

#include "MQTTClient.h"
#include "DeviceClient.h"

using namespace IoTF;

CommandHandler handler = NULL;
void msgArrived(MQTT::MessageData& md);

/**
 * A client, used by device, that handles connections with the IBM Internet of Things Foundation.
 * This class allows device to publish events and receive commands to/from IBM IoT Foundation wtih simple function calls.
 */
DeviceClient::DeviceClient():mqttClient(ipstack) {
    LOG("Constructor#1 called::\n");
    this->org = NULL;
    this->deviceType = NULL;
    this->deviceId = NULL;    
    this->authMethod = NULL;
    this->authToken = NULL;
}

DeviceClient::DeviceClient(char *org, char *deviceType, char *deviceId):
    mqttClient(ipstack) {

    LOG("Constructor#2 called:: org=%s, type=%s, id=%s", (org==NULL)?"NULL":org,
                    (deviceType==NULL)?"NULL":deviceType, (deviceId==NULL)?"NULL":deviceId);
 
    this->org = org;
    this->deviceType = deviceType;
    this->deviceId = deviceId;
    this->authMethod = NULL;
    this->authToken = NULL; 
    
    if(strcmp(this->org, QUICKSTART) != 0) {
        WARN("Registered flow must provide valid token");
    }
}

DeviceClient::DeviceClient(char *org, char *deviceType, 
            char *deviceId, char *authMethod, char *authToken):
    mqttClient(ipstack) {

    // Don't print token for security reasons
    LOG("Constructor#3 called:: org=%s, type=%s, id=%s", (org==NULL)?"NULL":org,
                    (deviceType==NULL)?"NULL":deviceType, (deviceId==NULL)?"NULL":deviceId);
    this->org = org;
    this->deviceType = deviceType;
    this->deviceId = deviceId;
    this->authMethod = authMethod;
    this->authToken = authToken;
}

/**
 * Connect to the IBM Internet of Things Foundation
 */ 
bool DeviceClient::connect()
{   
    char *organizationName, *typeId, *id;
    // Check if any organization is set
    if(this->org == NULL) {
        organizationName = QUICKSTART;
    } else {
        organizationName = this->org;
    }
    
    // Check if device type is already mentioned
    if(this->deviceType == NULL) {
        typeId = "iotsample-mbed";
    } else {
        typeId = this->deviceType;
    }
    
    char hostname[strlen(organizationName) + strlen(IBM_IOT_MESSAGING) + 1];
    sprintf(hostname, "%s%s", organizationName, IBM_IOT_MESSAGING);
    
    EthernetInterface& eth = ipstack.getEth();

    // Get devices MAC address if deviceId is not set already
    if(this->deviceId == NULL || (strcmp("", this->deviceId) == 0)) {
        char tmpBuf[50];
        id = getMac(tmpBuf, sizeof(tmpBuf));
    } else {
        id = this->deviceId;
    }
    
    // Construct clientId - d:org:type:id
    char clientId[strlen(organizationName) + strlen(typeId) + strlen(id) + 5];
    sprintf(clientId, "d:%s:%s:%s", organizationName, typeId, id);
    
    logData(eth, hostname, clientId);
    
    // Initialize MQTT Connect
    MQTTPacket_connectData data = MQTTPacket_connectData_initializer;
    data.MQTTVersion = 4;
    data.clientID.cstring = clientId;
    
    int quickstartMode = (strcmp(organizationName, QUICKSTART) == 0);
    
    if (!quickstartMode) {        
        data.username.cstring = "use-token-auth";
        data.password.cstring = this->authToken;
    } 
    bool rc = tryConnect(hostname, data);
    // By default subscribe to commands if we are in registered flow
    if(rc == true && !quickstartMode) {
        subscribeToCommands();
    }
    return rc;
}

bool DeviceClient::tryConnect(char *hostname, MQTTPacket_connectData &data) {
    int rc = -1;
    int retryAttempt = 0;
    do {    
        rc = ipstack.connect(hostname, IBM_IOT_PORT, CONNECT_TIMEOUT);
        if (rc != 0) {
            WARN("IP Stack connect returned: %d\n", rc);    
        }

        // MQTT connect        
        if (rc == 0 && (rc = mqttClient.connect(data)) != 0) {
            WARN("MQTT connect returned %d\n", rc);
            if (rc == MQTT_NOT_AUTHORIZED || rc == MQTT_BAD_USERNAME_OR_PASSWORD)
                return false; // don't reattempt to connect if credentials are wrong
        } else if (rc == MQTT_CONNECTION_ACCEPTED) {
            return true;
        }
   
        int timeout = getConnTimeout(++retryAttempt);
        
        WARN("Retry attempt number %d waiting %d\n", retryAttempt, timeout);
        
        // if ipstack and client were on the heap we could deconstruct and goto a label where they are constructed
        //  or maybe just add the proper members to do this disconnect and call attemptConnect(...)
        
        // this works - reset the system when the retry count gets to a threshold
        if (retryAttempt == 5)
            NVIC_SystemReset();
        else
            wait(timeout);
    } while(true);
}

void DeviceClient::logData(EthernetInterface& eth, char *hostname, char *clientId) {
    // Network debug statements 
    LOG("=====================================\n");
    LOG("Connecting Ethernet.\n");
    LOG("IP ADDRESS: %s\n", eth.getIPAddress());
    LOG("MAC ADDRESS: %s\n", eth.getMACAddress());
    LOG("Gateway: %s\n", eth.getGateway());
    LOG("Network Mask: %s\n", eth.getNetworkMask());
    LOG("Server Hostname: %s\n", hostname);
    LOG("Client ID: %s\n", clientId);
    LOG("=====================================\n");
}

int DeviceClient::getConnTimeout(int attemptNumber)
{
    // Try to increase the timeout every time
    return (attemptNumber * attemptNumber * 5);
}


/**
 * Publish data to the IBM Internet of Things Foundation. Note that data is published 
 * by default at Quality of Service (QoS) 0, which means that a successful send 
 * does not guarantee receipt even if the publish has been successful.
 */
bool DeviceClient::publishEvent(char *eventName, char *data, MQTT::QoS qos)
{
    if(!mqttClient.isConnected()) {
        WARN("Client is not connected \n");
        return false;
    }
    
    MQTT::Message message;
    /* Topic format must be iot-2/evt/<eventName>/fmt/json (let us stick to json format for now)
     *
     * So length must be 10 + strlen(eventName) + 9 + 1
     * iot-2/evt/ = 10
     * /fmt/json = 9
     * NULL char = 1
     */
    
    char topic[10 + strlen(eventName) + 9 + 1];
    sprintf(topic, "%s%s%s", "iot-2/evt/", eventName, "/fmt/json");
            
    message.qos = qos;
    message.retained = false;
    message.dup = false;
    message.payload = (void*)data;
    message.payloadlen = strlen(data);
    
    LOG("Publishing %s\n", data);
    int rc = mqttClient.publish(topic, message);
    mqttClient.yield(10);
    return rc == 0;
}

void DeviceClient::setCommandCallback(CommandHandler callbackFunc) {
    handler = callbackFunc;
}
/**
 * Subscribe to commands from the application. This will be executed only for
 * registered flow (quickstart flow does not support command publish)
 */
int DeviceClient::subscribeToCommands() {
    int rc = 0;
    // iot-2/cmd/+/fmt/+
    if ((rc = mqttClient.subscribe("iot-2/cmd/+/fmt/+", MQTT::QOS2, msgArrived)) != 0)
        WARN("rc from MQTT subscribe is %d\n", rc); 
    return rc;
}

/**
 * Callback method to be registered with MQTT::Client. MQTT::Client calls whenever 
 * any command is published to the topic subscribed earlier.
 */
void msgArrived(MQTT::MessageData& md)
{
    // check whether callback is registered by the client code
    if(handler == NULL) {
        return;
    }
    
    MQTT::Message &message = md.message;
    char topic[md.topicName.lenstring.len + 1];
    
    sprintf(topic, "%.*s", md.topicName.lenstring.len, md.topicName.lenstring.data);
    
    LOG("Message arrived on topic %s: %.*s\n",  topic, message.payloadlen, message.payload);
          
    // Command topic: iot-2/cmd/blink/fmt/json - cmd is the string between cmd/ and /fmt/
    char* start = strstr(topic, "/cmd/") + 5;
    int len = strstr(topic, "/fmt/") - start;

    char name[len + 1];
    
    memcpy(name, start, len);
    name[len] = NULL;
    
    start = strstr(topic, "/fmt/") + 5;
      
    char format[20];  // ToDO: need to find the length of the format
    strcpy(format, start);
    
    char payload[message.payloadlen + 1];
    sprintf(payload, "%.*s", message.payloadlen, (char*)message.payload);
    
    IoTF::Command cmd(name, format, payload);
    (*handler)(cmd);
}

bool DeviceClient::disconnect() {
    if(mqttClient.isConnected()) {
        int rc = mqttClient.disconnect();
        return rc == 0;
    }
    return false;
}

// Yield to allow MQTT client to process the command
void DeviceClient::yield(int ms) {
    if(mqttClient.isConnected()) {
        mqttClient.yield(ms);
    }
}

// Obtain MAC address
char* DeviceClient::getMac(char* buf, int buflen)    
{   
    EthernetInterface& eth = ipstack.getEth();
    strncpy(buf, eth.getMACAddress(), buflen);

    char* pos;                                                 // Remove colons from mac address
    while ((pos = strchr(buf, ':')) != NULL)
        memmove(pos, pos + 1, strlen(pos) + 1);
    return buf;
}