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

510 lines
19 KiB
Java

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 2018-2022 by Marcel Bokhorst (M66B)
*/
import android.accounts.AccountsException;
import android.content.Context;
import android.content.SharedPreferences;
import android.net.ConnectivityManager;
import android.net.Network;
import android.net.NetworkCapabilities;
import android.net.NetworkInfo;
import android.os.Build;
import android.provider.Settings;
import android.telephony.TelephonyManager;
import androidx.annotation.Nullable;
import androidx.preference.PreferenceManager;
import com.sun.mail.iap.ConnectionException;
import com.sun.mail.util.FolderClosedIOException;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.security.cert.Certificate;
import java.security.cert.CertificateParsingException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Locale;
import java.util.Objects;
import javax.net.SocketFactory;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;
public class ConnectionHelper {
static final List<String> PREF_NETWORK = Collections.unmodifiableList(Arrays.asList(
"metered", "roaming", "rlah", "require_validated", "vpn_only" // update network state
));
// 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(
"AT", // Austria
"BE", // Belgium
"BG", // Bulgaria
"HR", // Croatia
"CY", // Cyprus
"CZ", // Czech Republic
"DK", // Denmark
"EE", // Estonia
"FI", // Finland
"FR", // France
"DE", // Germany
"GR", // Greece
"HU", // Hungary
"IS", // Iceland
"IE", // Ireland
"IT", // Italy
"LV", // Latvia
"LI", // Liechtenstein
"LT", // Lithuania
"LU", // Luxembourg
"MT", // Malta
"NL", // Netherlands
"NO", // Norway
"PL", // Poland
"PT", // Portugal
"RE", // La Réunion
"RO", // Romania
"SK", // Slovakia
"SI", // Slovenia
"ES", // Spain
"SE" // Sweden
));
static {
System.loadLibrary("fairemail");
}
public static native int jni_socket_keep_alive(int fd, int seconds);
public static native int jni_socket_get_send_buffer(int fd);
static class NetworkState {
private Boolean connected = null;
private Boolean suitable = null;
private Boolean unmetered = null;
private Boolean roaming = null;
private Network active = null;
boolean isConnected() {
return (connected != null && connected);
}
boolean isSuitable() {
return (suitable != null && suitable);
}
boolean isUnmetered() {
return (unmetered != null && unmetered);
}
boolean isRoaming() {
return (roaming != null && roaming);
}
Network getActive() {
return active;
}
public void update(NetworkState newState) {
connected = newState.connected;
suitable = newState.suitable;
unmetered = newState.unmetered;
roaming = newState.roaming;
active = newState.active;
}
@Override
public boolean equals(@Nullable Object obj) {
if (obj instanceof NetworkState) {
NetworkState other = (NetworkState) obj;
return (Objects.equals(this.connected, other.connected) &&
Objects.equals(this.suitable, other.suitable) &&
Objects.equals(this.unmetered, other.unmetered) &&
Objects.equals(this.roaming, other.roaming) &&
Objects.equals(this.active, other.active));
} else
return false;
}
@Override
public String toString() {
return "connected=" + connected +
" suitable=" + suitable +
" unmetered=" + unmetered +
" roaming=" + roaming +
" active=" + active;
}
}
static boolean isConnected(Context context, Network network) {
NetworkInfo ni = getNetworkInfo(context, network);
return (ni != null && ni.isConnected());
}
static NetworkInfo getNetworkInfo(Context context, Network network) {
try {
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
return (cm == null ? null : cm.getNetworkInfo(network));
} catch (Throwable ex) {
Log.e(ex);
return null;
}
}
static NetworkState getNetworkState(Context context) {
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
boolean metered = prefs.getBoolean("metered", true);
boolean roaming = prefs.getBoolean("roaming", true);
boolean rlah = prefs.getBoolean("rlah", true);
NetworkState state = new NetworkState();
try {
Boolean isMetered = isMetered(context);
state.connected = (isMetered != null);
state.unmetered = (isMetered != null && !isMetered);
state.suitable = (isMetered != null && (metered || !isMetered));
state.active = getActiveNetwork(context);
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (state.connected && !roaming) {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.P) {
NetworkInfo ani = (cm == null ? null : cm.getActiveNetworkInfo());
if (ani != null)
state.roaming = ani.isRoaming();
} else {
Network active = (cm == null ? null : cm.getActiveNetwork());
if (active != null) {
NetworkCapabilities caps = cm.getNetworkCapabilities(active);
if (caps != null)
state.roaming = !caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING);
}
}
if (state.roaming != null && state.roaming && rlah)
try {
TelephonyManager tm = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
if (tm != null) {
String sim = tm.getSimCountryIso();
String network = tm.getNetworkCountryIso();
Log.i("Country SIM=" + sim + " network=" + network);
if (sim != null && network != null &&
RLAH_COUNTRY_CODES.contains(sim.toUpperCase()) &&
RLAH_COUNTRY_CODES.contains(network.toUpperCase()))
state.roaming = false;
}
} catch (Throwable ex) {
Log.w(ex);
}
}
} catch (Throwable ex) {
Log.e(ex);
}
return state;
}
private static Boolean isMetered(Context context) {
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
boolean standalone_vpn = prefs.getBoolean("standalone_vpn", false);
boolean require_validated = prefs.getBoolean("require_validated", false);
boolean vpn_only = prefs.getBoolean("vpn_only", false);
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (cm == null) {
Log.i("isMetered: no connectivity manager");
return null;
}
if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.M) {
NetworkInfo ani = cm.getActiveNetworkInfo();
if (ani == null || !ani.isConnected())
return null;
return cm.isActiveNetworkMetered();
}
Network active = cm.getActiveNetwork();
if (active == null) {
Log.i("isMetered: no active network");
return null;
}
// onLost [... state: SUSPENDED/SUSPENDED ... available: true]
// onLost [... state: DISCONNECTED/DISCONNECTED ... available: true]
NetworkInfo ani = cm.getNetworkInfo(active);
if (ani == null || ani.getState() != NetworkInfo.State.CONNECTED) {
Log.i("isMetered: no/connected active info ani=" + ani);
if (ani == null ||
ani.getState() != NetworkInfo.State.SUSPENDED ||
ani.getType() != ConnectivityManager.TYPE_VPN)
return null;
}
NetworkCapabilities caps = cm.getNetworkCapabilities(active);
if (caps == null) {
Log.i("isMetered: active no caps");
return null; // network unknown
}
Log.i("isMetered: active caps=" + caps);
if (caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VPN)) {
if (!caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)) {
Log.i("isMetered: no internet");
return null;
}
if (require_validated &&
Build.VERSION.SDK_INT >= Build.VERSION_CODES.M &&
!caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_VALIDATED)) {
Log.i("isMetered: not validated");
return null;
}
}
if (!caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED)) {
Log.i("isMetered: active restricted");
return null;
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P &&
!caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_FOREGROUND)) {
Log.i("isMetered: active background");
return null;
}
if (vpn_only) {
boolean vpn = vpnActive(context);
Log.i("VPN only vpn=" + vpn);
if (!vpn)
return null;
}
if (standalone_vpn ||
caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VPN)) {
// NET_CAPABILITY_NOT_METERED is unreliable on older Android versions
boolean metered = cm.isActiveNetworkMetered();
Log.i("isMetered: active not VPN metered=" + metered);
return metered;
}
// VPN: evaluate underlying networks
Integer transport = null;
if (caps.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR))
transport = NetworkCapabilities.TRANSPORT_CELLULAR;
else if (caps.hasTransport(NetworkCapabilities.TRANSPORT_WIFI))
transport = NetworkCapabilities.TRANSPORT_WIFI;
boolean underlying = false;
Network[] networks = cm.getAllNetworks();
for (Network network : networks) {
caps = cm.getNetworkCapabilities(network);
if (caps == null) {
Log.i("isMetered: no underlying caps");
continue; // network unknown
}
Log.i("isMetered: underlying caps=" + caps);
if (!caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)) {
Log.i("isMetered: underlying no internet");
continue;
}
if (!caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED)) {
Log.i("isMetered: underlying restricted");
continue;
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P &&
!caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_FOREGROUND)) {
Log.i("isMetered: underlying background");
continue;
}
if (!caps.hasTransport(NetworkCapabilities.TRANSPORT_VPN) &&
(caps.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) ||
caps.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)) &&
(transport != null && !caps.hasTransport(transport))) {
Log.i("isMetered: underlying other transport");
continue;
}
if (caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VPN)) {
underlying = true;
Log.i("isMetered: underlying is connected");
if (caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED)) {
Log.i("isMetered: underlying is unmetered");
return false;
}
}
}
if (!underlying)
return null;
// Assume metered
Log.i("isMetered: underlying assume metered");
return true;
}
static Network getActiveNetwork(Context context) {
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (cm == null)
return null;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
return cm.getActiveNetwork();
NetworkInfo ani = cm.getActiveNetworkInfo();
if (ani == null)
return null;
Network[] networks = cm.getAllNetworks();
for (Network network : networks) {
NetworkInfo ni = cm.getNetworkInfo(network);
if (ni == null)
continue;
if (ni.getType() == ani.getType() &&
ni.getSubtype() == ani.getSubtype())
return network;
}
return null;
}
static boolean isIoError(Throwable ex) {
while (ex != null) {
if (isMaxConnections(ex.getMessage()) ||
ex instanceof IOException ||
ex instanceof FolderClosedIOException ||
ex instanceof ConnectionException ||
ex instanceof AccountsException ||
ex instanceof InterruptedException ||
"EOF on socket".equals(ex.getMessage()) ||
"Read timed out".equals(ex.getMessage()) || // POP3
"failed to connect".equals(ex.getMessage()))
return true;
ex = ex.getCause();
}
return false;
}
static boolean isMaxConnections(Throwable ex) {
while (ex != null) {
if (isMaxConnections(ex.getMessage()))
return true;
ex = ex.getCause();
}
return false;
}
static boolean isMaxConnections(String message) {
return (message != null &&
(message.contains("Too many simultaneous connections") /* Gmail */ ||
message.contains("Maximum number of connections") /* ... from user+IP exceeded */ /* Dovecot */ ||
message.contains("Too many concurrent connections") /* ... to this mailbox */ ||
message.contains("User is authenticated but not connected") /* Outlook */ ||
message.contains("Account is temporarily unavailable") /* Arcor.de / TalkTalk.net */ ||
message.contains("Connection dropped by server?")));
}
static Boolean isSyntacticallyInvalid(Throwable ex) {
if (ex.getMessage() == null)
return false;
// 501 HELO requires valid address
// 501 Syntactically invalid HELO argument(s)
String message = ex.getMessage().toLowerCase(Locale.ROOT);
return message.contains("syntactically invalid") ||
message.contains("requires valid address");
}
static boolean isDataSaving(Context context) {
// https://developer.android.com/training/basics/network-ops/data-saver.html
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N)
return false;
ConnectivityManager cm =
(ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (cm == null)
return false;
// RESTRICT_BACKGROUND_STATUS_DISABLED: Data Saver is disabled.
// RESTRICT_BACKGROUND_STATUS_ENABLED: The user has enabled Data Saver for this app. (Globally)
// RESTRICT_BACKGROUND_STATUS_WHITELISTED: The user has enabled Data Saver but the app is allowed to bypass it.
int status = cm.getRestrictBackgroundStatus();
return (status == ConnectivityManager.RESTRICT_BACKGROUND_STATUS_ENABLED);
}
static boolean vpnActive(Context context) {
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (cm == null)
return false;
try {
for (Network network : cm.getAllNetworks()) {
NetworkCapabilities caps = cm.getNetworkCapabilities(network);
if (caps != null && caps.hasTransport(NetworkCapabilities.TRANSPORT_VPN))
return true;
}
} catch (Throwable ex) {
Log.w(ex);
}
return false;
}
static boolean airplaneMode(Context context) {
return Settings.Global.getInt(context.getContentResolver(),
Settings.Global.AIRPLANE_MODE_ON, 0) != 0;
}
static List<String> getCommonNames(Context context, String domain, int port, int timeout) throws IOException {
List<String> result = new ArrayList<>();
InetSocketAddress address = new InetSocketAddress(domain, port);
SocketFactory factory = SSLSocketFactory.getDefault();
try (SSLSocket sslSocket = (SSLSocket) factory.createSocket()) {
EntityLog.log(context, "Connecting to " + address);
sslSocket.connect(address, timeout);
EntityLog.log(context, "Connected " + address);
sslSocket.setSoTimeout(timeout);
sslSocket.startHandshake();
Certificate[] certs = sslSocket.getSession().getPeerCertificates();
for (Certificate cert : certs)
if (cert instanceof X509Certificate) {
try {
result.addAll(EntityCertificate.getDnsNames((X509Certificate) cert));
} catch (CertificateParsingException ex) {
Log.w(ex);
}
}
}
return result;
}
}