stack_wallet/lib/electrumx_rpc/rpc.dart
2023-08-09 12:15:25 -05:00

393 lines
11 KiB
Dart

/*
* This file is part of Stack Wallet.
*
* Copyright (c) 2023 Cypher Stack
* All Rights Reserved.
* The code is distributed under GPLv3 license, see LICENSE file for details.
* Generated by Cypher Stack on 2023-05-26
*
*/
import 'dart:async';
import 'dart:convert';
import 'dart:io';
import 'package:flutter/foundation.dart';
import 'package:mutex/mutex.dart';
import 'package:stackwallet/networking/tor_service.dart';
import 'package:stackwallet/utilities/logger.dart';
import 'package:stackwallet/utilities/prefs.dart';
// Json RPC class to handle connecting to electrumx servers
class JsonRPC {
JsonRPC({
required this.host,
required this.port,
this.useSSL = false,
this.connectionTimeout = const Duration(seconds: 60),
required ({String host, int port})? proxyInfo,
});
final bool useSSL;
final String host;
final int port;
final Duration connectionTimeout;
({String host, int port})? proxyInfo;
final _requestMutex = Mutex();
final _JsonRPCRequestQueue _requestQueue = _JsonRPCRequestQueue();
Socket? _socket; // TODO make a SocksSocket extension/wrapper or similar
StreamSubscription<Uint8List>? _subscription;
void _dataHandler(List<int> data) {
_requestQueue.nextIncompleteReq.then((req) {
if (req != null) {
req.appendDataAndCheckIfComplete(data);
if (req.isComplete) {
_onReqCompleted(req);
}
} else {
Logging.instance.log(
"_dataHandler found a null req!",
level: LogLevel.Warning,
);
}
});
}
void _errorHandler(Object error, StackTrace trace) {
_requestQueue.nextIncompleteReq.then((req) {
if (req != null) {
req.completer.completeError(error, trace);
_onReqCompleted(req);
}
});
}
void _doneHandler() {
disconnect(reason: "JsonRPC _doneHandler() called");
}
void _onReqCompleted(_JsonRPCRequest req) {
_requestQueue.remove(req).then((_) {
// attempt to send next request
_sendNextAvailableRequest();
});
}
void _sendNextAvailableRequest() {
_requestQueue.nextIncompleteReq.then((req) {
if (req != null) {
// \r\n required by electrumx server
if (_socksSocket != null) {
_socksSocket!.write('${req.jsonRequest}\r\n');
} else {
_socket!.write('${req.jsonRequest}\r\n');
}
// TODO different timeout length?
req.initiateTimeout(
onTimedOut: () {
_requestQueue.remove(req);
},
);
}
});
}
Future<JsonRPCResponse> request(
String jsonRpcRequest,
Duration requestTimeout,
) async {
await _requestMutex.protect(() async {
if (_socket == null && _socksSocket == null) {
Logging.instance.log(
"JsonRPC request: opening socket $host:$port",
level: LogLevel.Info,
);
await connect();
}
});
final req = _JsonRPCRequest(
jsonRequest: jsonRpcRequest,
requestTimeout: requestTimeout,
completer: Completer<JsonRPCResponse>(),
);
final future = req.completer.future.onError(
(error, stackTrace) async {
await disconnect(
reason: "return req.completer.future.onError: $error\n$stackTrace",
);
return JsonRPCResponse(
exception: error is Exception
? error
: Exception(
"req.completer.future.onError: $error\n$stackTrace",
),
);
},
);
// if this is the only/first request then send it right away
await _requestQueue.add(
req,
onInitialRequestAdded: _sendNextAvailableRequest,
);
return future;
}
Future<void> disconnect({required String reason}) async {
await _requestMutex.protect(() async {
await _subscription?.cancel();
_subscription = null;
_socket?.destroy();
_socket = null;
// clean up remaining queue
await _requestQueue.completeRemainingWithError(
"JsonRPC disconnect() called with reason: \"$reason\"",
);
});
}
Future<void> connect() async {
if (Prefs.instance.useTor) {
if (_socksSocket != null) {
Logging.instance.log(
"JsonRPC.connect(): JsonRPC attempted to connect to an already existing tor socket!",
level: LogLevel.Error);
throw Exception(
"JsonRPC attempted to connect to an already existing tor socket!",
);
}
if (proxyInfo == null) {
// TODO await tor / make sure it's running
proxyInfo = (
host: InternetAddress.loopbackIPv4.address,
port: TorService.sharedInstance.port
);
Logging.instance.log(
"ElectrumX.connect(): no tor proxy info, read $proxyInfo",
level: LogLevel.Warning);
}
final InternetAddress _host =
await InternetAddress.lookup(host).then((value) => value.first);
_socksSocket = await SocksTCPClient.connect(
[
ProxySettings(
InternetAddress.loopbackIPv4,
proxyInfo!.port,
)
],
_host,
port,
);
if (_socksSocket == null) {
Logging.instance.log(
"JsonRPC.connect(): failed to connect to $host over tor proxy at $proxyInfo",
level: LogLevel.Error);
throw Exception("JsonRPC.connect(): failed to connect to tor proxy");
} else {
Logging.instance.log(
"JsonRPC.connect(): connected to $host over tor proxy at $proxyInfo",
level: LogLevel.Info);
}
if (Prefs.instance.useTor) {
if (proxyInfo == null) {
// TODO await tor / make sure it's running
proxyInfo = (
host: InternetAddress.loopbackIPv4.address,
port: TorService.sharedInstance.port
);
Logging.instance.log(
"ElectrumX.connect(): no tor proxy info, read $proxyInfo",
level: LogLevel.Warning);
}
// TODO connect to proxy socket...
// https://github.com/LacticWhale/socks_dart/blob/master/lib/src/client/socks_client.dart#L50C46-L50C56
// TODO implement ssl over tor
// if (useSSL) {
// _socket = await SecureSocket.connect(
// host,
// port,
// timeout: connectionTimeout,
// onBadCertificate: (_) => true,
// ); // TODO do not automatically trust bad certificates
// final _client = SocksSocket.protected(_socket, type);
// } else {
_socket = await Socket.connect(
proxyInfo!.host,
proxyInfo!.port,
timeout: connectionTimeout,
);
// final _client = SocksSocket.protected(
// _socket!, SocksConnectionType.connect
// );
// final InternetAddress _host =
// await InternetAddress.lookup(host).then((value) => value.first);
// var _socket = await SocksSocket.initialize(
// [
// ProxySettings(
// InternetAddress.loopbackIPv4,
// proxyInfo!.port,
// )
// ],
// _host,
// port,
// SocksConnectionType.connect,
// );
if (_socket == null) {
Logging.instance.log(
"JsonRPC.connect(): failed to connect to $host over tor proxy at $proxyInfo",
level: LogLevel.Error);
throw Exception("JsonRPC.connect(): failed to connect to tor proxy");
} else {
Logging.instance.log(
"JsonRPC.connect(): connected to $host over tor proxy at $proxyInfo",
level: LogLevel.Info);
}
} else {
if (useSSL) {
_socket = await SecureSocket.connect(
host,
port,
timeout: connectionTimeout,
onBadCertificate: (_) => true,
); // TODO do not automatically trust bad certificates
} else {
_socket = await Socket.connect(
host,
port,
timeout: connectionTimeout,
);
}
}
}
}
class _JsonRPCRequestQueue {
final _lock = Mutex();
final List<_JsonRPCRequest> _rq = [];
Future<void> add(
_JsonRPCRequest req, {
VoidCallback? onInitialRequestAdded,
}) async {
return await _lock.protect(() async {
_rq.add(req);
if (_rq.length == 1) {
onInitialRequestAdded?.call();
}
});
}
Future<bool> remove(_JsonRPCRequest req) async {
return await _lock.protect(() async {
final result = _rq.remove(req);
return result;
});
}
Future<_JsonRPCRequest?> get nextIncompleteReq async {
return await _lock.protect(() async {
int removeCount = 0;
_JsonRPCRequest? returnValue;
for (final req in _rq) {
if (req.isComplete) {
removeCount++;
} else {
returnValue = req;
break;
}
}
_rq.removeRange(0, removeCount);
return returnValue;
});
}
Future<void> completeRemainingWithError(
String error, {
StackTrace? stackTrace,
}) async {
await _lock.protect(() async {
for (final req in _rq) {
if (!req.isComplete) {
req.completer.completeError(Exception(error), stackTrace);
}
}
_rq.clear();
});
}
Future<bool> get isEmpty async {
return await _lock.protect(() async {
return _rq.isEmpty;
});
}
}
class _JsonRPCRequest {
// 0x0A is newline
// https://electrumx-spesmilo.readthedocs.io/en/latest/protocol-basics.html
static const int separatorByte = 0x0A;
final String jsonRequest;
final Completer<JsonRPCResponse> completer;
final Duration requestTimeout;
final List<int> _responseData = [];
_JsonRPCRequest({
required this.jsonRequest,
required this.completer,
required this.requestTimeout,
});
void appendDataAndCheckIfComplete(List<int> data) {
_responseData.addAll(data);
if (data.last == separatorByte) {
try {
final response = json.decode(String.fromCharCodes(_responseData));
completer.complete(JsonRPCResponse(data: response));
} catch (e, s) {
Logging.instance.log(
"JsonRPC json.decode: $e\n$s",
level: LogLevel.Error,
);
completer.completeError(e, s);
}
}
}
void initiateTimeout({
VoidCallback? onTimedOut,
}) {
Future<void>.delayed(requestTimeout).then((_) {
if (!isComplete) {
try {
throw Exception("_JsonRPCRequest timed out: $jsonRequest");
} catch (e, s) {
completer.completeError(e, s);
onTimedOut?.call();
}
}
});
}
bool get isComplete => completer.isCompleted;
}
class JsonRPCResponse {
final dynamic data;
final Exception? exception;
JsonRPCResponse({this.data, this.exception});
}