Fixed local IP address class

app/src/main/java/eu/faircode/email/FragmentIdentity.java

@@ -52,6 +52,7 @@ import com.android.colorpicker.ColorPickerSwatch;
 import com.google.android.material.snackbar.Snackbar;
 import com.google.android.material.textfield.TextInputLayout;
 
+import java.net.Inet4Address;
 import java.net.Inet6Address;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
@@ -595,31 +596,29 @@ public class FragmentIdentity extends FragmentBase {
 
                 // Check SMTP server
                 if (check) {
+                    String protocol = (starttls ? "smtp" : "smtps");
+
                     // Get properties
                     Properties props = MessageHelper.getSessionProperties(auth_type, realm, insecure);
-                    InetAddress ip = (use_ip ? Helper.getLocalIp(context) : null);
+
-                    if (ip == null) {
+                    String haddr;
-                        Log.i("Check local host=" + host);
+                    if (use_ip) {
-                        if (starttls)
+                        InetAddress addr = InetAddress.getByName(host);
-                            props.put("mail.smtp.localhost", host);
+                        if (addr instanceof Inet4Address)
-                        else
+                            haddr = "[" + Inet4Address.getLocalHost().getHostAddress() + "]";
-                            props.put("mail.smtps.localhost", host);
-                    } else {
-                        InetAddress localhost = InetAddress.getLocalHost();
-                        String haddr = "[" + (localhost instanceof Inet6Address ? "IPv6:" : "") + localhost.getHostAddress() + "]";
-                        Log.i("Check local address=" + haddr);
-                        if (starttls)
-                            props.put("mail.smtp.localhost", haddr);
                         else
-                            props.put("mail.smtps.localhost", haddr);
+                            haddr = "[IPv6:" + Inet6Address.getLocalHost().getHostAddress() + "]";
-                    }
+                    } else
+                        haddr = host;
+
+                    Log.i("Send localhost=" + haddr);
+                    props.put("mail." + protocol + ".localhost", haddr);
 
                     // Create session
                     Session isession = Session.getInstance(props, null);
                     isession.setDebug(true);
 
                     // Create transport
-                    String protocol = (starttls ? "smtp" : "smtps");
                     try (Transport itransport = isession.getTransport(protocol)) {
                         try {
                             itransport.connect(host, Integer.parseInt(port), user, password);

app/src/main/java/eu/faircode/email/Helper.java

@@ -36,8 +36,6 @@ import android.content.res.TypedArray;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.net.ConnectivityManager;
-import android.net.LinkAddress;
-import android.net.LinkProperties;
 import android.net.Network;
 import android.net.NetworkCapabilities;
 import android.net.NetworkInfo;
@@ -76,9 +74,6 @@ import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.io.UnsupportedEncodingException;
-import java.net.Inet4Address;
-import java.net.InetAddress;
-import java.net.UnknownHostException;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.text.DateFormat;
@@ -699,43 +694,6 @@ public class Helper {
         return filename.substring(index + 1);
     }
 
-    static InetAddress getLocalIp(Context context) throws UnknownHostException {
-        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
-
-        if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.M)
-            return InetAddress.getLocalHost();
-
-        Network active = cm.getActiveNetwork();
-        if (active == null)
-            return null;
-
-        NetworkInfo ani = cm.getNetworkInfo(active);
-        if (ani == null || !ani.isConnected())
-            return null;
-
-        NetworkCapabilities caps = cm.getNetworkCapabilities(active);
-        if (caps == null)
-            return null;
-
-        if (!caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VPN))
-            return null;
-
-        LinkProperties props = cm.getLinkProperties(active);
-        if (props == null)
-            return null;
-
-        List<LinkAddress> addresses = props.getLinkAddresses();
-        if (addresses == null || addresses.size() == 0)
-            return null;
-
-        // Prefer IPv4
-        for (LinkAddress address : addresses)
-            if (address.getAddress() instanceof Inet4Address)
-                return address.getAddress();
-
-        return addresses.get(0).getAddress();
-    }
-
     static Boolean isMetered(Context context, boolean log) {
         ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
 

app/src/main/java/eu/faircode/email/ServiceSend.java

@@ -33,6 +33,7 @@ import android.text.TextUtils;
 
 import java.io.File;
 import java.io.IOException;
+import java.net.Inet4Address;
 import java.net.Inet6Address;
 import java.net.InetAddress;
 import java.util.ArrayList;
@@ -193,25 +194,23 @@ public class ServiceSend extends LifecycleService {
         }
 
         EntityIdentity ident = db.identity().getIdentity(message.identity);
+        String protocol = ident.getProtocol();
 
         // Get properties
         Properties props = MessageHelper.getSessionProperties(ident.auth_type, ident.realm, ident.insecure);
-        InetAddress ip = (ident.use_ip ? Helper.getLocalIp(this) : null);
+
-        if (ip == null) {
+        String haddr;
-            EntityLog.log(this, "Send local host=" + ident.host);
+        if (ident.use_ip) {
-            if (ident.starttls)
+            InetAddress addr = InetAddress.getByName(ident.host);
-                props.put("mail.smtp.localhost", ident.host);
+            if (addr instanceof Inet4Address)
-            else
+                haddr = "[" + Inet4Address.getLocalHost().getHostAddress() + "]";
-                props.put("mail.smtps.localhost", ident.host);
-        } else {
-            InetAddress localhost = InetAddress.getLocalHost();
-            String haddr = "[" + (localhost instanceof Inet6Address ? "IPv6:" : "") + localhost.getHostAddress() + "]";
-            EntityLog.log(this, "Send local address=" + haddr);
-            if (ident.starttls)
-                props.put("mail.smtp.localhost", haddr);
             else
-                props.put("mail.smtps.localhost", haddr);
+                haddr = "[IPv6:" + Inet6Address.getLocalHost().getHostAddress() + "]";
-        }
+        } else
+            haddr = ident.host;
+
+        EntityLog.log(this, "Send localhost=" + haddr);
+        props.put("mail." + protocol + ".localhost", haddr);
 
         // Create session
         final Session isession = Session.getInstance(props, null);
@@ -244,7 +243,7 @@ public class ServiceSend extends LifecycleService {
 
         // Create transport
         // TODO: cache transport?
-        try (Transport itransport = isession.getTransport(ident.getProtocol())) {
+        try (Transport itransport = isession.getTransport(protocol)) {
             // Connect transport
             db.identity().setIdentityState(ident.id, "connecting");
             try {