automatic failover between wifi/mobile if server cannot be reached; send timestamp of incoming message to server

AndroidManifest.xml

@@ -1,11 +1,15 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
       package="org.envaya.sms"
-      android:versionCode="11"
+      android:versionCode="12"
-      android:versionName="2.0-rc1">
+      android:versionName="2.0-rc2">
          
     <uses-sdk android:minSdkVersion="4" />
          
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />              
+    <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />              
+    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
+    <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
     <uses-permission android:name="android.permission.RECEIVE_SMS" />     
     <uses-permission android:name="android.permission.RECEIVE_MMS" />
     <uses-permission android:name="android.permission.SEND_SMS" />
@@ -80,6 +84,9 @@
         <receiver android:name=".receiver.IncomingMessageRetry">
         </receiver>            
         
+        <receiver android:name=".receiver.ReenableWifiReceiver">
+        </receiver>
+        
         <receiver android:name=".receiver.BootReceiver">
             <intent-filter> 
                  <action android:name="android.intent.action.BOOT_COMPLETED" /> 
@@ -95,6 +102,12 @@
             </intent-filter>            
         </receiver>        
         
+        <receiver android:name=".receiver.ConnectivityChangeReceiver" > 
+            <intent-filter> 
+                <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
+            </intent-filter> 
+        </receiver>         
+        
         <service android:name=".CheckMmsInboxService">
         </service>
 

res/xml/prefs.xml

@@ -54,6 +54,13 @@
     >           
     </ListPreference>
     
+    <CheckBoxPreference
+            android:key="network_failover"
+            android:title="Network Failover"
+            android:summaryOff="Do nothing if phone can't connect to server via Wi-Fi"
+            android:summaryOn="Automatically switch to mobile data if phone can't connect to server via Wi-Fi"
+    ></CheckBoxPreference>
+    
     <CheckBoxPreference
             android:key="test_mode"
             android:title="Test mode"

server/php/EnvayaSMS.php

@@ -183,6 +183,7 @@ class EnvayaSMS_Action_Incoming extends EnvayaSMS_Action
     public $message;        // The message body of the SMS, or the content of the text/plain part of the MMS.
     public $message_type;   // EnvayaSMS::MESSAGE_TYPE_MMS or EnvayaSMS::MESSAGE_TYPE_SMS
     public $mms_parts;      // array of EnvayaSMS_MMS_Part instances
+    public $timestamp;      // timestamp of incoming message (added in version 12)
 
     function __construct($request)
     {
@@ -191,6 +192,7 @@ class EnvayaSMS_Action_Incoming extends EnvayaSMS_Action
         $this->from = $_POST['from'];
         $this->message = $_POST['message'];
         $this->message_type = $_POST['message_type'];
+        $this->timestamp = @$_POST['timestamp'];
         
         if ($this->message_type == EnvayaSMS::MESSAGE_TYPE_MMS)
         {

src/org/envaya/sms/App.java

@@ -10,7 +10,10 @@ import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager.NameNotFoundException;
+import android.net.ConnectivityManager;
+import android.net.NetworkInfo;
 import android.net.Uri;
+import android.net.wifi.WifiManager;
 import android.os.Bundle;
 import android.os.SystemClock;
 import android.preference.PreferenceManager;
@@ -18,6 +21,8 @@ import android.telephony.SmsManager;
 import android.text.Html;
 import android.text.SpannableStringBuilder;
 import android.util.Log;
+import java.io.IOException;
+import java.net.InetAddress;
 import java.text.DateFormat;
 import java.util.ArrayList;
 import java.util.Comparator;
@@ -40,6 +45,7 @@ import org.apache.http.params.HttpParams;
 import org.apache.http.params.HttpProtocolParams;
 import org.envaya.sms.receiver.DequeueOutgoingMessageReceiver;
 import org.envaya.sms.receiver.OutgoingMessagePoller;
+import org.envaya.sms.receiver.ReenableWifiReceiver;
 import org.envaya.sms.task.HttpTask;
 import org.envaya.sms.task.PollerTask;
 import org.json.JSONArray;
@@ -94,11 +100,18 @@ public final class App extends Application {
     public static final Uri INCOMING_URI = Uri.withAppendedPath(CONTENT_URI, "incoming");
     public static final Uri OUTGOING_URI = Uri.withAppendedPath(CONTENT_URI, "outgoing");
     
+    // how long we disable wifi when there is no connection to the server
+    // (should be longer than CONNECTIVITY_FAILOVER_INTERVAL)
+    public static final int DISABLE_WIFI_INTERVAL = 3600000; 
+    
+    // how often we can automatically failover between wifi/mobile connection
+    public static final int CONNECTIVITY_FAILOVER_INTERVAL = 1800000;
+    
     // max per-app outgoing SMS rate used by com.android.internal.telephony.SMSDispatcher
     // with a slightly longer check period to account for variance in the time difference
     // between when we prepare messages and when SMSDispatcher receives them
-    public static int OUTGOING_SMS_CHECK_PERIOD = 3605000; // one hour plus 5 sec (in ms)    
+    public static final int OUTGOING_SMS_CHECK_PERIOD = 3605000; // one hour plus 5 sec (in ms)    
-    public static int OUTGOING_SMS_MAX_COUNT = 100;
+    public static final int OUTGOING_SMS_MAX_COUNT = 100;
     
     private Map<Uri, IncomingMessage> incomingMessages = new HashMap<Uri, IncomingMessage>();
     private Map<Uri, OutgoingMessage> outgoingMessages = new HashMap<Uri, OutgoingMessage>();    
@@ -417,6 +430,11 @@ public final class App extends Application {
         return settings.getBoolean("enabled", false);
     }
     
+    public boolean isNetworkFailoverEnabled()
+    {
+        return settings.getBoolean("network_failover", false);
+    }
+    
     public boolean isTestMode()
     {
         return settings.getBoolean("test_mode", false);
@@ -713,14 +731,16 @@ public final class App extends Application {
 
     public synchronized void retryIncomingMessage(Uri uri) {
         IncomingMessage message = incomingMessages.get(uri);
-        if (message != null) {
+        if (message != null 
+            && message.getProcessingState() == IncomingMessage.ProcessingState.Scheduled) {
             enqueueIncomingMessage(message);
         }
     }
 
     public synchronized void retryOutgoingMessage(Uri uri) {
         OutgoingMessage sms = outgoingMessages.get(uri);
-        if (sms != null) {
+        if (sms != null 
+            && sms.getProcessingState() == OutgoingMessage.ProcessingState.Scheduled) {
             enqueueOutgoingMessage(sms);
         }
     }
@@ -898,4 +918,189 @@ public final class App extends Application {
         }
         return httpClient;
     }      
+    
+    private class ConnectivityCheckState
+    {
+        //private int networkType;
+        private long lastCheckTime;  // when we checked connectivity on this network
+        
+        public ConnectivityCheckState(int networkType)
+        {
+            //this.networkType = networkType;
+        }
+        
+        public synchronized boolean canCheck()
+        {
+            long time = SystemClock.elapsedRealtime();                
+            return (time - lastCheckTime >= App.CONNECTIVITY_FAILOVER_INTERVAL);
+        }                    
+        
+        public void setChecked()
+        {
+            lastCheckTime = SystemClock.elapsedRealtime();
+        }
+    }
+    
+    private Map<Integer,ConnectivityCheckState> connectivityCheckStates
+        = new HashMap<Integer, ConnectivityCheckState>();
+        
+    private Thread connectivityThread;    
+        
+    /*
+     * Normally we rely on Android to automatically switch between 
+     * mobile data and Wi-Fi, but if the phone is connected to a Wi-Fi router
+     * that doesn't have a connection to the internet, Android won't know 
+     * the difference. So we if we can't actually reach the remote host via
+     * the current connection, we toggle the Wi-Fi radio so that Android
+     * will switch to the other connection. 
+     * 
+     * If the host is unreachable on both connections, we don't want to
+     * keep toggling the radio forever, so there is a timeout before we can 
+     * recheck connectivity on a particular connection.
+     * 
+     * When we disable the Wi-Fi radio, we set a timeout to reenable it after
+     * a while in hopes that connectivity will be restored.
+     */
+    public synchronized void asyncCheckConnectivity()
+    {          
+        ConnectivityManager cm = 
+            (ConnectivityManager)getSystemService(CONNECTIVITY_SERVICE);
+
+        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();                
+
+        if (activeNetwork == null || !activeNetwork.isConnected())
+        {
+            WifiManager wmgr = (WifiManager)getSystemService(Context.WIFI_SERVICE);
+            
+            if (!wmgr.isWifiEnabled() && isNetworkFailoverEnabled())
+            {
+                wmgr.setWifiEnabled(true);
+            }
+            return;
+        }
+        
+        final int networkType = activeNetwork.getType();                
+        
+        ConnectivityCheckState state = 
+            connectivityCheckStates.get(networkType);
+        
+        if (state == null)
+        {
+            state = new ConnectivityCheckState(networkType);
+            connectivityCheckStates.put(networkType, state);
+        }
+
+        if (!state.canCheck()
+            || (connectivityThread != null && connectivityThread.isAlive()))
+        {
+            return;
+        }
+        
+        state.setChecked();
+        
+        connectivityThread = new Thread() {
+            @Override
+            public void run()
+            {
+                Uri serverUrl = Uri.parse(getServerUrl());
+                String hostName = serverUrl.getHost();
+
+                log("Checking connectivity to "+hostName+"...");
+
+                try
+                {
+                    InetAddress addr = InetAddress.getByName(hostName);
+                    if (addr.isReachable(App.HTTP_CONNECTION_TIMEOUT))
+                    {
+                        log("OK");                        
+                        onConnectivityRestored();
+                        return;
+                    }
+                }
+                catch (IOException ex)
+                {
+                    // just what we suspected... 
+                    // server not reachable on this interface
+                }
+                
+                log("Can't connect to "+hostName+".");
+                
+                WifiManager wmgr = (WifiManager)getSystemService(Context.WIFI_SERVICE);
+                
+                if (!isNetworkFailoverEnabled())
+                {
+                    log("Network failover disabled.");
+                }
+                else if (networkType == ConnectivityManager.TYPE_WIFI)
+                {
+                    log("Switching from WIFI to MOBILE");                
+
+                    PendingIntent pendingIntent = PendingIntent.getBroadcast(App.this,
+                        0,
+                        new Intent(App.this, ReenableWifiReceiver.class),
+                        0);
+
+                    // set an alarm to try restoring Wi-Fi in a little while
+                    AlarmManager alarm = 
+                        (AlarmManager)getSystemService(Context.ALARM_SERVICE);
+
+                    alarm.set(
+                        AlarmManager.ELAPSED_REALTIME_WAKEUP,                        
+                        SystemClock.elapsedRealtime() + App.DISABLE_WIFI_INTERVAL,
+                        pendingIntent);   
+
+                    wmgr.setWifiEnabled(false);
+                }
+                else if (networkType == ConnectivityManager.TYPE_MOBILE 
+                        && !wmgr.isWifiEnabled())
+                {
+                    log("Switching from MOBILE to WIFI");
+                    wmgr.setWifiEnabled(true);                    
+                }
+                else
+                {
+                    log("Can't automatically fix connectivity.");
+                }     
+            }
+        };
+        connectivityThread.start();
+    }
+    
+    private int activeNetworkType = -1;
+    
+    public synchronized void onConnectivityChanged()
+    {
+        ConnectivityManager cm = 
+            (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
+        
+        NetworkInfo networkInfo = cm.getActiveNetworkInfo();
+        
+        if (networkInfo == null || !networkInfo.isConnected())
+        {
+            return;
+        }
+        
+        int networkType = networkInfo.getType();
+        
+        if (networkType == activeNetworkType)
+        {
+            return;
+        }
+        
+        activeNetworkType = networkType;        
+        log("Connected to " + networkInfo.getTypeName());        
+        asyncCheckConnectivity();
+    }
+    
+    public void onConnectivityRestored()
+    {
+        retryStuckIncomingMessages();  
+        
+        if (getOutgoingPollSeconds() > 0)
+        {
+            checkOutgoingMessages();
+        }
+        
+        // failed outgoing message status notifications are dropped...
+    }
 }

src/org/envaya/sms/IncomingMessage.java

@@ -1,12 +1,12 @@
 package org.envaya.sms;
 
 import android.content.Intent;
-import android.net.Uri;
 import org.envaya.sms.receiver.IncomingMessageRetry;
 
 public abstract class IncomingMessage extends QueuedMessage {
 
     protected String from;
+    protected long timestamp; // unix timestamp in milliseconds
     
     private ProcessingState state = ProcessingState.None;
         
@@ -17,10 +17,16 @@ public abstract class IncomingMessage extends QueuedMessage {
         Scheduled       // waiting for a while before retrying after failure forwarding
     }    
     
-    public IncomingMessage(App app, String from)
+    public IncomingMessage(App app, String from, long timestamp)
     {
         super(app);
         this.from = from;
+        this.timestamp = timestamp;
+    }
+    
+    public long getTimestamp()
+    {
+        return timestamp;
     }
     
     public ProcessingState getProcessingState()

src/org/envaya/sms/IncomingMms.java

@@ -19,9 +19,9 @@ public class IncomingMms extends IncomingMessage {
     long id;
     String contentLocation;
     
-    public IncomingMms(App app, String from, long id)
+    public IncomingMms(App app, String from, long timestamp, long id)
     {
-        super(app, from);
+        super(app, from, timestamp);
         this.parts = new ArrayList<MmsPart>();
         this.id = id;
     }        
@@ -155,7 +155,6 @@ public class IncomingMms extends IncomingMessage {
         }
         
         ForwarderTask task = new ForwarderTask(this,            
-            new BasicNameValuePair("from", getFrom()),
             new BasicNameValuePair("message", message),
             new BasicNameValuePair("message_type", App.MESSAGE_TYPE_MMS),
             new BasicNameValuePair("mms_parts", partsMetadata.toString())

src/org/envaya/sms/IncomingSms.java

@@ -12,11 +12,13 @@ import org.envaya.sms.task.ForwarderTask;
 public class IncomingSms extends IncomingMessage {
     
     protected String message;
-    protected long timestampMillis;           
     
     // constructor for SMS retrieved from android.provider.Telephony.SMS_RECEIVED intent
     public IncomingSms(App app, List<SmsMessage> smsParts) throws InvalidParameterException {
-        super(app, smsParts.get(0).getOriginatingAddress());
+        super(app, 
+            smsParts.get(0).getOriginatingAddress(),
+            smsParts.get(0).getTimestampMillis()
+        );
         
         this.message = smsParts.get(0).getMessageBody();
         
@@ -34,15 +36,12 @@ public class IncomingSms extends IncomingMessage {
             
             message = message + smsPart.getMessageBody();
         }
-                
-        this.timestampMillis = smsParts.get(0).getTimestampMillis();
     }
     
     // constructor for SMS retrieved from Messaging inbox
     public IncomingSms(App app, String from, String message, long timestampMillis) {
-        super(app, from);
+        super(app, from, timestampMillis);
         this.message = message;
-        this.timestampMillis = timestampMillis;
     }        
     
     public String getMessageBody()
@@ -60,7 +59,7 @@ public class IncomingSms extends IncomingMessage {
         return Uri.withAppendedPath(App.INCOMING_URI, 
                 "sms/" + 
                 Uri.encode(from) + "/" 
-                + timestampMillis + "/" + 
+                + timestamp + "/" + 
                 Uri.encode(message));
     }        
 
@@ -72,7 +71,6 @@ public class IncomingSms extends IncomingMessage {
         }
         
         new ForwarderTask(this,
-            new BasicNameValuePair("from", getFrom()),
             new BasicNameValuePair("message_type", App.MESSAGE_TYPE_SMS),
             new BasicNameValuePair("message", getMessageBody())            
         ).execute();

src/org/envaya/sms/MmsUtils.java

@@ -107,7 +107,7 @@ public class MmsUtils
         String m_type = "" + MESSAGE_TYPE_RETRIEVE_CONF;
 
         Cursor c = contentResolver.query(INBOX_URI, 
-                new String[] {"_id", "ct_l"}, 
+                new String[] {"_id", "ct_l", "date"}, 
                 "m_type = ? ", new String[] { m_type }, null);
         
         List<IncomingMms> messages = new ArrayList<IncomingMms>();        
@@ -115,8 +115,13 @@ public class MmsUtils
         while (c.moveToNext())
         {         
             long id = c.getLong(0);                               
+            long date = c.getLong(2);
                         
-            IncomingMms mms = new IncomingMms(app, getSenderNumber(id), id);
+            IncomingMms mms = new IncomingMms(app, 
+                getSenderNumber(id), 
+                date * 1000, // MMS timestamp is in seconds for some reason, 
+                             // while everything else is in ms
+                id);
             
             mms.setContentLocation(c.getString(1));
                         

src/org/envaya/sms/QueuedMessage.java

@@ -36,11 +36,11 @@ public abstract class QueuedMessage
         int minute = second * 60;
 
         if (numRetries == 1) {
-            app.log("1st failure; retry in 1 minute");
+            app.log("1st failure; retry in 20 seconds");
-            nextRetryTime = now + 1 * minute;
+            nextRetryTime = now + 20 * second;
         } else if (numRetries == 2) {
-            app.log("2nd failure; retry in 10 minutes");
+            app.log("2nd failure; retry in 5 minutes");
-            nextRetryTime = now + 10 * minute;
+            nextRetryTime = now + 5 * minute;
         } else if (numRetries == 3) {
             app.log("3rd failure; retry in 1 hour");
             nextRetryTime = now + 60 * minute;

src/org/envaya/sms/receiver/ConnectivityChangeReceiver.java

@@ -0,0 +1,24 @@
+
+package org.envaya.sms.receiver;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.net.ConnectivityManager;
+import android.net.NetworkInfo;
+import org.envaya.sms.App;
+
+public class ConnectivityChangeReceiver extends BroadcastReceiver {
+
+    @Override
+    public void onReceive(Context context, Intent intent) {
+        final App app = (App) context.getApplicationContext();
+        
+        if (!app.isEnabled())
+        {
+            return;
+        }
+        
+        app.onConnectivityChanged();
+    }    
+}

src/org/envaya/sms/receiver/DequeueOutgoingMessageReceiver.java

@@ -10,6 +10,12 @@ public class DequeueOutgoingMessageReceiver extends BroadcastReceiver {
     @Override
     public void onReceive(Context context, Intent intent) {
         App app = (App) context.getApplicationContext();
+        
+        if (!app.isEnabled())
+        {
+            return;
+        }
+        
         app.maybeDequeueOutgoingMessage();
     }
 }

src/org/envaya/sms/receiver/IncomingMessageRetry.java

@@ -12,6 +12,11 @@ public class IncomingMessageRetry extends BroadcastReceiver
     public void onReceive(Context context, Intent intent) 
     {        
         App app = (App) context.getApplicationContext();
+        if (!app.isEnabled())
+        {
+            return;
+        }
+        
         app.retryIncomingMessage(intent.getData());        
     }        
 }    

src/org/envaya/sms/receiver/OutgoingMessageRetry.java

@@ -12,6 +12,10 @@ public class OutgoingMessageRetry extends BroadcastReceiver
     public void onReceive(Context context, Intent intent) 
     {        
         App app = (App) context.getApplicationContext();
+        if (!app.isEnabled())
+        {
+            return;
+        }        
         app.retryOutgoingMessage(intent.getData());        
     }
 }    

src/org/envaya/sms/receiver/ReenableWifiReceiver.java

@@ -0,0 +1,29 @@
+package org.envaya.sms.receiver;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.net.wifi.WifiManager;
+import org.envaya.sms.App;
+
+public class ReenableWifiReceiver extends BroadcastReceiver {
+
+    @Override
+    public void onReceive(Context context, Intent intent) {
+        App app = (App) context.getApplicationContext();
+        
+        if (!app.isEnabled())
+        {
+            return;
+        }        
+        
+        WifiManager wmgr = 
+                (WifiManager)app.getSystemService(Context.WIFI_SERVICE);
+        
+        if (!wmgr.isWifiEnabled())
+        {
+            app.log("Reenabling Wi-Fi");
+            wmgr.setWifiEnabled(true);
+        }
+    }
+}

src/org/envaya/sms/task/ForwarderTask.java

@@ -8,18 +8,20 @@ import org.envaya.sms.OutgoingMessage;
 
 public class ForwarderTask extends HttpTask {
 
-    private IncomingMessage originalSms;
+    private IncomingMessage message;
 
-    public ForwarderTask(IncomingMessage originalSms, BasicNameValuePair... paramsArr) {
+    public ForwarderTask(IncomingMessage message, BasicNameValuePair... paramsArr) {
-        super(originalSms.app, paramsArr);
+        super(message.app, paramsArr);
-        this.originalSms = originalSms;
+        this.message = message;
                 
         params.add(new BasicNameValuePair("action", App.ACTION_INCOMING));
+        params.add(new BasicNameValuePair("from", message.getFrom()));
+        params.add(new BasicNameValuePair("timestamp", "" + message.getTimestamp()));
     }
     
     @Override
     protected String getDefaultToAddress() {
-        return originalSms.getFrom();
+        return message.getFrom();
     }
 
     @Override
@@ -29,11 +31,11 @@ public class ForwarderTask extends HttpTask {
             app.sendOutgoingMessage(reply);
         }
 
-        app.setIncomingMessageStatus(originalSms, true);
+        app.setIncomingMessageStatus(message, true);
     }
 
     @Override
     protected void handleFailure() {
-        app.setIncomingMessageStatus(originalSms, false);
+        app.setIncomingMessageStatus(message, false);
     }
 }

src/org/envaya/sms/task/HttpTask.java

@@ -8,6 +8,8 @@ import android.os.AsyncTask;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.UnsupportedEncodingException;
+import java.net.SocketTimeoutException;
+import java.net.UnknownHostException;
 import java.nio.charset.Charset;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
@@ -32,7 +34,6 @@ import org.envaya.sms.Base64Coder;
 import org.envaya.sms.OutgoingMessage;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
-import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;
 import org.xml.sax.SAXException;
 
@@ -159,6 +160,11 @@ public class HttpTask extends AsyncTask<String, Void, HttpResponse> {
         {
             post.abort();
             app.logError("Error while contacting server", ex);
+            
+            if (ex instanceof UnknownHostException || ex instanceof SocketTimeoutException)
+            {                
+                app.asyncCheckConnectivity();
+            }
             return null;
         }
         catch (Throwable ex)