Diff: DeviceClient.cpp

Revision:

0:f86732d81998

Child:

1:31c93319bbd8

Child:

2:199ddea804cd

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DeviceClient.cpp	Fri Nov 06 07:09:14 2015 +0000
@@ -0,0 +1,296 @@
+/*******************************************************************************
+ * 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;
+}
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