Refactoring

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

@@ -1,10 +1,28 @@
 package eu.faircode.email;
 
+/*
+    This file is part of FairEmail.
+
+    FairEmail is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    FairEmail is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with FairEmail.  If not, see <http://www.gnu.org/licenses/>.
+
+    Copyright 2018-2020 by Marcel Bokhorst (M66B)
+*/
+
 import android.accounts.AccountsException;
 import android.content.Context;
 import android.content.SharedPreferences;
 import android.net.ConnectivityManager;
-import android.net.LinkProperties;
 import android.net.Network;
 import android.net.NetworkCapabilities;
 import android.net.NetworkInfo;
@@ -17,27 +35,13 @@ import androidx.preference.PreferenceManager;
 
 import com.sun.mail.iap.ConnectionException;
 
-import org.xbill.DNS.Lookup;
-import org.xbill.DNS.MXRecord;
-import org.xbill.DNS.Record;
-import org.xbill.DNS.SimpleResolver;
-import org.xbill.DNS.Type;
-
 import java.io.IOException;
-import java.net.InetAddress;
-import java.net.UnknownHostException;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
 
-import javax.mail.Address;
-import javax.mail.internet.InternetAddress;
-
 public class ConnectionHelper {
-    // https://dns.watch/
-    private static final String DEFAULT_DNS = "84.200.69.80";
-
     // Roam like at home
     // https://en.wikipedia.org/wiki/European_Union_roaming_regulations
     private static final List<String> RLAH_COUNTRY_CODES = Collections.unmodifiableList(Arrays.asList(
@@ -332,106 +336,4 @@ public class ConnectionHelper {
         return Settings.System.getInt(context.getContentResolver(),
                 Settings.Global.AIRPLANE_MODE_ON, 0) != 0;
     }
-
-    static String getDnsServer(Context context) {
-        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
-        if (cm == null)
-            return DEFAULT_DNS;
-
-        LinkProperties props = null;
-
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M)
-            for (Network network : cm.getAllNetworks()) {
-                NetworkInfo ni = cm.getNetworkInfo(network);
-                if (ni != null && ni.isConnected()) {
-                    props = cm.getLinkProperties(network);
-                    Log.i("Old props=" + props);
-                    break;
-                }
-            }
-        else {
-            Network active = cm.getActiveNetwork();
-            if (active == null)
-                return DEFAULT_DNS;
-            props = cm.getLinkProperties(active);
-            Log.i("New props=" + props);
-        }
-
-        if (props == null)
-            return DEFAULT_DNS;
-
-        List<InetAddress> dns = props.getDnsServers();
-        if (dns.size() == 0)
-            return DEFAULT_DNS;
-        else
-            return dns.get(0).getHostAddress();
-    }
-
-    static boolean lookupMx(Address[] addresses, Context context) throws UnknownHostException {
-        boolean ok = true;
-
-        if (addresses != null)
-            for (Address address : addresses)
-                try {
-                    String email = ((InternetAddress) address).getAddress();
-                    if (email == null)
-                        continue;
-
-                    int d = email.lastIndexOf("@");
-                    if (d < 0)
-                        continue;
-
-                    String domain = email.substring(d + 1);
-                    Lookup lookup = new Lookup(domain, Type.MX);
-                    SimpleResolver resolver = new SimpleResolver(ConnectionHelper.getDnsServer(context));
-                    lookup.setResolver(resolver);
-                    Log.i("Lookup MX=" + domain + " @" + resolver.getAddress());
-
-                    lookup.run();
-                    if (lookup.getResult() == Lookup.HOST_NOT_FOUND ||
-                            lookup.getResult() == Lookup.TYPE_NOT_FOUND) {
-                        Log.i("Lookup MX=" + domain + " result=" + lookup.getErrorString());
-                        throw new UnknownHostException(context.getString(R.string.title_no_server, domain));
-                    } else if (lookup.getResult() != Lookup.SUCCESSFUL)
-                        ok = false;
-                } catch (UnknownHostException ex) {
-                    throw ex;
-                } catch (Throwable ex) {
-                    Log.e(ex);
-                    ok = false;
-                }
-
-        return ok;
-    }
-
-    static InetAddress lookupMx(String domain, Context context) {
-        try {
-            Lookup lookup = new Lookup(domain, Type.MX);
-            SimpleResolver resolver = new SimpleResolver(getDnsServer(context));
-            lookup.setResolver(resolver);
-            Log.i("Lookup MX=" + domain + " @" + resolver.getAddress());
-
-            lookup.run();
-            if (lookup.getResult() == Lookup.SUCCESSFUL) {
-                Record[] answers = lookup.getAnswers();
-                if (answers != null && answers.length > 0 && answers[0] instanceof MXRecord) {
-                    MXRecord mx = (MXRecord) answers[0];
-                    return InetAddress.getByName(mx.getTarget().toString(true));
-                }
-            }
-        } catch (Throwable ex) {
-            Log.w(ex);
-        }
-
-        return null;
-    }
-
-    static String getParentDomain(String host) {
-        if (host != null) {
-            String[] h = host.split("\\.");
-            if (h.length >= 2)
-                return h[h.length - 2] + "." + h[h.length - 1];
-        }
-        return host;
-    }
 }

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

@@ -2284,9 +2284,9 @@ class Core {
             boolean check_mx = prefs.getBoolean("check_mx", false);
             if (check_mx)
                 try {
-                    if (ConnectionHelper.lookupMx(
+                    if (DNSHelper.lookupMx(
-                            message.reply == null || message.reply.length == 0
+                            context, message.reply == null || message.reply.length == 0
-                                    ? message.from : message.reply, context))
+                                    ? message.from : message.reply))
                         message.mx = true;
                 } catch (UnknownHostException ex) {
                     message.mx = false;
@@ -2347,12 +2347,12 @@ class Core {
                     String r = ((InternetAddress) reply).getAddress();
                     int rat = (r == null ? -1 : r.indexOf('@'));
                     if (rat > 0) {
-                        String rdomain = ConnectionHelper.getParentDomain(r.substring(rat + 1));
+                        String rdomain = DNSHelper.getParentDomain(r.substring(rat + 1));
                         for (Address from : message.from) {
                             String f = ((InternetAddress) from).getAddress();
                             int fat = (f == null ? -1 : f.indexOf('@'));
                             if (fat > 0) {
-                                String fdomain = ConnectionHelper.getParentDomain(f.substring(fat + 1));
+                                String fdomain = DNSHelper.getParentDomain(f.substring(fat + 1));
                                 if (!rdomain.equalsIgnoreCase(fdomain)) {
                                     if (message.warning == null)
                                         message.warning = context.getString(R.string.title_reply_domain, fdomain, rdomain);

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

@@ -0,0 +1,175 @@
+package eu.faircode.email;
+
+/*
+    This file is part of FairEmail.
+
+    FairEmail is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    FairEmail is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with FairEmail.  If not, see <http://www.gnu.org/licenses/>.
+
+    Copyright 2018-2020 by Marcel Bokhorst (M66B)
+*/
+
+import android.content.Context;
+import android.net.ConnectivityManager;
+import android.net.LinkProperties;
+import android.net.Network;
+import android.net.NetworkInfo;
+import android.os.Build;
+
+import androidx.annotation.NonNull;
+
+import org.xbill.DNS.Lookup;
+import org.xbill.DNS.MXRecord;
+import org.xbill.DNS.Record;
+import org.xbill.DNS.SimpleResolver;
+import org.xbill.DNS.TextParseException;
+import org.xbill.DNS.Type;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.List;
+
+import javax.mail.Address;
+import javax.mail.internet.InternetAddress;
+
+public class DNSHelper {
+    // https://dns.watch/
+    private static final String DEFAULT_DNS = "84.200.69.80";
+
+    static boolean lookupMx(Context context, Address[] addresses) throws UnknownHostException {
+        boolean ok = true;
+
+        if (addresses != null)
+            for (Address address : addresses)
+                try {
+                    String email = ((InternetAddress) address).getAddress();
+                    if (email == null)
+                        continue;
+
+                    int d = email.lastIndexOf("@");
+                    if (d < 0)
+                        continue;
+
+                    String domain = email.substring(d + 1);
+                    Lookup lookup = new Lookup(domain, Type.MX);
+                    SimpleResolver resolver = new SimpleResolver(getDnsServer(context));
+                    lookup.setResolver(resolver);
+                    Log.i("Lookup MX=" + domain + " @" + resolver.getAddress());
+
+                    lookup.run();
+                    if (lookup.getResult() == Lookup.HOST_NOT_FOUND ||
+                            lookup.getResult() == Lookup.TYPE_NOT_FOUND) {
+                        Log.i("Lookup MX=" + domain + " result=" + lookup.getErrorString());
+                        throw new UnknownHostException(context.getString(R.string.title_no_server, domain));
+                    } else if (lookup.getResult() != Lookup.SUCCESSFUL)
+                        ok = false;
+                } catch (UnknownHostException ex) {
+                    throw ex;
+                } catch (Throwable ex) {
+                    Log.e(ex);
+                    ok = false;
+                }
+
+        return ok;
+    }
+
+    static InetAddress lookupMx(Context context, String domain) {
+        try {
+            Lookup lookup = new Lookup(domain, Type.MX);
+            SimpleResolver resolver = new SimpleResolver(getDnsServer(context));
+            lookup.setResolver(resolver);
+            Log.i("Lookup MX=" + domain + " @" + resolver.getAddress());
+
+            lookup.run();
+            if (lookup.getResult() == Lookup.SUCCESSFUL) {
+                Record[] answers = lookup.getAnswers();
+                if (answers != null && answers.length > 0 && answers[0] instanceof MXRecord) {
+                    MXRecord mx = (MXRecord) answers[0];
+                    return InetAddress.getByName(mx.getTarget().toString(true));
+                }
+            }
+        } catch (Throwable ex) {
+            Log.w(ex);
+        }
+
+        return null;
+    }
+
+    @NonNull
+    static Record[] lookup(Context context, String name, int type) throws TextParseException, UnknownHostException {
+        Lookup lookup = new Lookup(name, type);
+
+        SimpleResolver resolver = new SimpleResolver(getDnsServer(context));
+        lookup.setResolver(resolver);
+        Log.i("Lookup name=" + name + " @" + resolver.getAddress() + " type=" + type);
+        Record[] records = lookup.run();
+
+        if (lookup.getResult() != Lookup.SUCCESSFUL)
+            if (lookup.getResult() == Lookup.HOST_NOT_FOUND ||
+                    lookup.getResult() == Lookup.TYPE_NOT_FOUND)
+                throw new UnknownHostException(name);
+            else
+                throw new UnknownHostException(lookup.getErrorString());
+
+        if (records.length == 0)
+            throw new UnknownHostException(name);
+
+        for (Record record : records)
+            Log.i("Found record=" + record);
+
+        return records;
+    }
+
+    static String getParentDomain(String host) {
+        if (host != null) {
+            String[] h = host.split("\\.");
+            if (h.length >= 2)
+                return h[h.length - 2] + "." + h[h.length - 1];
+        }
+        return host;
+    }
+
+    private static String getDnsServer(Context context) {
+        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
+        if (cm == null)
+            return DEFAULT_DNS;
+
+        LinkProperties props = null;
+
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M)
+            for (Network network : cm.getAllNetworks()) {
+                NetworkInfo ni = cm.getNetworkInfo(network);
+                if (ni != null && ni.isConnected()) {
+                    props = cm.getLinkProperties(network);
+                    Log.i("Old props=" + props);
+                    break;
+                }
+            }
+        else {
+            Network active = cm.getActiveNetwork();
+            if (active == null)
+                return DEFAULT_DNS;
+            props = cm.getLinkProperties(active);
+            Log.i("New props=" + props);
+        }
+
+        if (props == null)
+            return DEFAULT_DNS;
+
+        List<InetAddress> dns = props.getDnsServers();
+        if (dns.size() == 0)
+            return DEFAULT_DNS;
+        else
+            return dns.get(0).getHostAddress();
+    }
+}

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

@@ -25,11 +25,9 @@ import android.text.TextUtils;
 
 import androidx.annotation.NonNull;
 
-import org.xbill.DNS.Lookup;
 import org.xbill.DNS.MXRecord;
 import org.xbill.DNS.Record;
 import org.xbill.DNS.SRVRecord;
-import org.xbill.DNS.SimpleResolver;
 import org.xbill.DNS.TextParseException;
 import org.xbill.DNS.Type;
 import org.xmlpull.v1.XmlPullParser;
@@ -228,7 +226,7 @@ public class EmailProvider {
 
             try {
                 // Retry at MX server addresses
-                Record[] records = lookupDNS(context, domain, Type.MX);
+                Record[] records = DNSHelper.lookup(context, domain, Type.MX);
                 for (Record record : records) {
                     String target = ((MXRecord) record).getTarget().toString(true);
                     while (autoconfig == null && target != null && target.indexOf('.') > 0) {
@@ -507,7 +505,7 @@ public class EmailProvider {
         if (discover == Discover.ALL || discover == Discover.IMAP) {
             try {
                 // Identifies an IMAP server where TLS is initiated directly upon connection to the IMAP server.
-                Record[] records = lookupDNS(context, "_imaps._tcp." + domain, Type.SRV);
+                Record[] records = DNSHelper.lookup(context, "_imaps._tcp." + domain, Type.SRV);
                 // ... service is not supported at all at a particular domain by setting the target of an SRV RR to "."
                 SRVRecord srv = (SRVRecord) records[0];
                 provider.imap.host = srv.getTarget().toString(true);
@@ -515,7 +513,7 @@ public class EmailProvider {
                 provider.imap.starttls = false;
             } catch (UnknownHostException ex) {
                 // Identifies an IMAP server that MAY ... require the MUA to use the "STARTTLS" command
-                Record[] records = lookupDNS(context, "_imap._tcp." + domain, Type.SRV);
+                Record[] records = DNSHelper.lookup(context, "_imap._tcp." + domain, Type.SRV);
                 SRVRecord srv = (SRVRecord) records[0];
                 provider.imap.host = srv.getTarget().toString(true);
                 provider.imap.port = srv.getPort();
@@ -525,7 +523,7 @@ public class EmailProvider {
 
         if (discover == Discover.ALL || discover == Discover.SMTP) {
             // Note that this covers connections both with and without Transport Layer Security (TLS)
-            Record[] records = lookupDNS(context, "_submission._tcp." + domain, Type.SRV);
+            Record[] records = DNSHelper.lookup(context, "_submission._tcp." + domain, Type.SRV);
             SRVRecord srv = (SRVRecord) records[0];
             provider.smtp.host = srv.getTarget().toString(true);
             provider.smtp.port = srv.getPort();
@@ -618,31 +616,6 @@ public class EmailProvider {
         provider.documentation.append("<a href=\"").append(href).append("\">").append(title).append("</a>");
     }
 
-    @NonNull
-    private static Record[] lookupDNS(Context context, String name, int type) throws TextParseException, UnknownHostException {
-        Lookup lookup = new Lookup(name, type);
-
-        SimpleResolver resolver = new SimpleResolver(ConnectionHelper.getDnsServer(context));
-        lookup.setResolver(resolver);
-        Log.i("Lookup name=" + name + " @" + resolver.getAddress() + " type=" + type);
-        Record[] records = lookup.run();
-
-        if (lookup.getResult() != Lookup.SUCCESSFUL)
-            if (lookup.getResult() == Lookup.HOST_NOT_FOUND ||
-                    lookup.getResult() == Lookup.TYPE_NOT_FOUND)
-                throw new UnknownHostException(name);
-            else
-                throw new UnknownHostException(lookup.getErrorString());
-
-        if (records.length == 0)
-            throw new UnknownHostException(name);
-
-        for (Record record : records)
-            Log.i("Found record=" + record);
-
-        return records;
-    }
-
     @NonNull
     @Override
     public String toString() {

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

@@ -1077,7 +1077,7 @@ public class FragmentAccount extends FragmentBase {
                     db.beginTransaction();
 
                     if (account != null && !account.password.equals(password)) {
-                        String domain = ConnectionHelper.getParentDomain(account.host);
+                        String domain = DNSHelper.getParentDomain(account.host);
                         String match = (Objects.equals(account.host, domain) ? account.host : "%." + domain);
                         int count = db.identity().setIdentityPassword(account.id, account.user, password, match);
                         Log.i("Updated passwords=" + count + " match=" + match);

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

@@ -3818,7 +3818,7 @@ public class FragmentCompose extends FragmentBase {
                                 for (InternetAddress address : ato)
                                     address.validate();
                                 if (lookup_mx)
-                                    ConnectionHelper.lookupMx(ato, context);
+                                    DNSHelper.lookupMx(context, ato);
                             }
                         } catch (AddressException ex) {
                             throw new AddressException(context.getString(R.string.title_address_parse_error,
@@ -3832,7 +3832,7 @@ public class FragmentCompose extends FragmentBase {
                                 for (InternetAddress address : acc)
                                     address.validate();
                                 if (lookup_mx)
-                                    ConnectionHelper.lookupMx(acc, context);
+                                    DNSHelper.lookupMx(context, acc);
                             }
                         } catch (AddressException ex) {
                             throw new AddressException(context.getString(R.string.title_address_parse_error,
@@ -3846,7 +3846,7 @@ public class FragmentCompose extends FragmentBase {
                                 for (InternetAddress address : abcc)
                                     address.validate();
                                 if (lookup_mx)
-                                    ConnectionHelper.lookupMx(abcc, context);
+                                    DNSHelper.lookupMx(context, abcc);
                             }
                         } catch (AddressException ex) {
                             throw new AddressException(context.getString(R.string.title_address_parse_error,

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

@@ -351,7 +351,7 @@ public class FragmentPop extends FragmentBase {
                     db.beginTransaction();
 
                     if (account != null && !account.password.equals(password)) {
-                        String domain = ConnectionHelper.getParentDomain(account.host);
+                        String domain = DNSHelper.getParentDomain(account.host);
                         String match = (Objects.equals(account.host, domain) ? account.host : "%." + domain);
                         int count = db.identity().setIdentityPassword(account.id, account.user, password, match);
                         Log.i("Updated passwords=" + count + " match=" + match);

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

@@ -47,7 +47,7 @@ public class IPInfo {
             if (to == null || !to.contains("@"))
                 throw new UnknownHostException();
             String domain = to.substring(to.indexOf('@') + 1);
-            InetAddress address = ConnectionHelper.lookupMx(domain, context);
+            InetAddress address = DNSHelper.lookupMx(context, domain);
             if (address == null)
                 throw new UnknownHostException();
             return new Pair<>(domain, getOrganization(address));