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/*
* Copyright 2016 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
package org.appspot.apprtc;
import android.util.Log;
import androidx.annotation.Nullable;
import java.util.ArrayList;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.webrtc.IceCandidate;
import org.webrtc.SessionDescription;
/**
* Implementation of AppRTCClient that uses direct TCP connection as the signaling channel.
* This eliminates the need for an external server. This class does not support loopback
* connections.
*/
public class DirectRTCClient implements AppRTCClient, TCPChannelClient.TCPChannelEvents {
private static final String TAG = "DirectRTCClient";
private static final int DEFAULT_PORT = 8888;
// Regex pattern used for checking if room id looks like an IP.
static final Pattern IP_PATTERN = Pattern.compile("("
// IPv4
+ "((\\d+\\.){3}\\d+)|"
// IPv6
+ "\\[((([0-9a-fA-F]{1,4}:)*[0-9a-fA-F]{1,4})?::"
+ "(([0-9a-fA-F]{1,4}:)*[0-9a-fA-F]{1,4})?)\\]|"
+ "\\[(([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4})\\]|"
// IPv6 without []
+ "((([0-9a-fA-F]{1,4}:)*[0-9a-fA-F]{1,4})?::(([0-9a-fA-F]{1,4}:)*[0-9a-fA-F]{1,4})?)|"
+ "(([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4})|"
// Literals
+ "localhost"
+ ")"
// Optional port number
+ "(:(\\d+))?");
private final ExecutorService executor;
private final SignalingEvents events;
@Nullable
private TCPChannelClient tcpClient;
private RoomConnectionParameters connectionParameters;
private enum ConnectionState { NEW, CONNECTED, CLOSED, ERROR }
// All alterations of the room state should be done from inside the looper thread.
private ConnectionState roomState;
public DirectRTCClient(SignalingEvents events) {
this.events = events;
executor = Executors.newSingleThreadExecutor();
roomState = ConnectionState.NEW;
}
/**
* Connects to the room, roomId in connectionsParameters is required. roomId must be a valid
* IP address matching IP_PATTERN.
*/
@Override
public void connectToRoom(RoomConnectionParameters connectionParameters) {
this.connectionParameters = connectionParameters;
if (connectionParameters.loopback) {
reportError("Loopback connections aren't supported by DirectRTCClient.");
}
executor.execute(new Runnable() {
@Override
public void run() {
connectToRoomInternal();
}
});
}
@Override
public void disconnectFromRoom() {
executor.execute(new Runnable() {
@Override
public void run() {
disconnectFromRoomInternal();
}
});
}
/**
* Connects to the room.
*
* Runs on the looper thread.
*/
private void connectToRoomInternal() {
this.roomState = ConnectionState.NEW;
String endpoint = connectionParameters.roomId;
Matcher matcher = IP_PATTERN.matcher(endpoint);
if (!matcher.matches()) {
reportError("roomId must match IP_PATTERN for DirectRTCClient.");
return;
}
String ip = matcher.group(1);
String portStr = matcher.group(matcher.groupCount());
int port;
if (portStr != null) {
try {
port = Integer.parseInt(portStr);
} catch (NumberFormatException e) {
reportError("Invalid port number: " + portStr);
return;
}
} else {
port = DEFAULT_PORT;
}
tcpClient = new TCPChannelClient(executor, this, ip, port);
}
/**
* Disconnects from the room.
*
* Runs on the looper thread.
*/
private void disconnectFromRoomInternal() {
roomState = ConnectionState.CLOSED;
if (tcpClient != null) {
tcpClient.disconnect();
tcpClient = null;
}
executor.shutdown();
}
@Override
public void sendOfferSdp(final SessionDescription sdp) {
executor.execute(new Runnable() {
@Override
public void run() {
if (roomState != ConnectionState.CONNECTED) {
reportError("Sending offer SDP in non connected state.");
return;
}
JSONObject json = new JSONObject();
jsonPut(json, "sdp", sdp.description);
jsonPut(json, "type", "offer");
sendMessage(json.toString());
}
});
}
@Override
public void sendAnswerSdp(final SessionDescription sdp) {
executor.execute(new Runnable() {
@Override
public void run() {
JSONObject json = new JSONObject();
jsonPut(json, "sdp", sdp.description);
jsonPut(json, "type", "answer");
sendMessage(json.toString());
}
});
}
@Override
public void sendLocalIceCandidate(final IceCandidate candidate) {
executor.execute(new Runnable() {
@Override
public void run() {
JSONObject json = new JSONObject();
jsonPut(json, "type", "candidate");
jsonPut(json, "label", candidate.sdpMLineIndex);
jsonPut(json, "id", candidate.sdpMid);
jsonPut(json, "candidate", candidate.sdp);
if (roomState != ConnectionState.CONNECTED) {
reportError("Sending ICE candidate in non connected state.");
return;
}
sendMessage(json.toString());
}
});
}
/** Send removed Ice candidates to the other participant. */
@Override
public void sendLocalIceCandidateRemovals(final IceCandidate[] candidates) {
executor.execute(new Runnable() {
@Override
public void run() {
JSONObject json = new JSONObject();
jsonPut(json, "type", "remove-candidates");
JSONArray jsonArray = new JSONArray();
for (final IceCandidate candidate : candidates) {
jsonArray.put(toJsonCandidate(candidate));
}
jsonPut(json, "candidates", jsonArray);
if (roomState != ConnectionState.CONNECTED) {
reportError("Sending ICE candidate removals in non connected state.");
return;
}
sendMessage(json.toString());
}
});
}
// -------------------------------------------------------------------
// TCPChannelClient event handlers
/**
* If the client is the server side, this will trigger onConnectedToRoom.
*/
@Override
public void onTCPConnected(boolean isServer) {
if (isServer) {
roomState = ConnectionState.CONNECTED;
SignalingParameters parameters = new SignalingParameters(
// Ice servers are not needed for direct connections.
new ArrayList<>(),
isServer, // Server side acts as the initiator on direct connections.
null, // clientId
null, // wssUrl
null, // wwsPostUrl
null, // offerSdp
null // iceCandidates
);
events.onConnectedToRoom(parameters);
}
}
@Override
public void onTCPMessage(String msg) {
try {
JSONObject json = new JSONObject(msg);
String type = json.optString("type");
if (type.equals("candidate")) {
events.onRemoteIceCandidate(toJavaCandidate(json));
} else if (type.equals("remove-candidates")) {
JSONArray candidateArray = json.getJSONArray("candidates");
IceCandidate[] candidates = new IceCandidate[candidateArray.length()];
for (int i = 0; i < candidateArray.length(); ++i) {
candidates[i] = toJavaCandidate(candidateArray.getJSONObject(i));
}
events.onRemoteIceCandidatesRemoved(candidates);
} else if (type.equals("answer")) {
SessionDescription sdp = new SessionDescription(
SessionDescription.Type.fromCanonicalForm(type), json.getString("sdp"));
events.onRemoteDescription(sdp);
} else if (type.equals("offer")) {
SessionDescription sdp = new SessionDescription(
SessionDescription.Type.fromCanonicalForm(type), json.getString("sdp"));
SignalingParameters parameters = new SignalingParameters(
// Ice servers are not needed for direct connections.
new ArrayList<>(),
false, // This code will only be run on the client side. So, we are not the initiator.
null, // clientId
null, // wssUrl
null, // wssPostUrl
sdp, // offerSdp
null // iceCandidates
);
roomState = ConnectionState.CONNECTED;
events.onConnectedToRoom(parameters);
} else {
reportError("Unexpected TCP message: " + msg);
}
} catch (JSONException e) {
reportError("TCP message JSON parsing error: " + e.toString());
}
}
@Override
public void onTCPError(String description) {
reportError("TCP connection error: " + description);
}
@Override
public void onTCPClose() {
events.onChannelClose();
}
// --------------------------------------------------------------------
// Helper functions.
private void reportError(final String errorMessage) {
Log.e(TAG, errorMessage);
executor.execute(new Runnable() {
@Override
public void run() {
if (roomState != ConnectionState.ERROR) {
roomState = ConnectionState.ERROR;
events.onChannelError(errorMessage);
}
}
});
}
private void sendMessage(final String message) {
executor.execute(new Runnable() {
@Override
public void run() {
tcpClient.send(message);
}
});
}
// Put a `key`->`value` mapping in `json`.
private static void jsonPut(JSONObject json, String key, Object value) {
try {
json.put(key, value);
} catch (JSONException e) {
throw new RuntimeException(e);
}
}
// Converts a Java candidate to a JSONObject.
private static JSONObject toJsonCandidate(final IceCandidate candidate) {
JSONObject json = new JSONObject();
jsonPut(json, "label", candidate.sdpMLineIndex);
jsonPut(json, "id", candidate.sdpMid);
jsonPut(json, "candidate", candidate.sdp);
return json;
}
// Converts a JSON candidate to a Java object.
private static IceCandidate toJavaCandidate(JSONObject json) throws JSONException {
return new IceCandidate(
json.getString("id"), json.getInt("label"), json.getString("candidate"));
}
}