zerotier_sockets

Description:

zerotier sockets

zerotier_sockets #

Flutter plugin providing bindings for the libzt library. Uses dart:ffi.
In order to distribute binaries it currently has to be a Flutter plugin, not a Dart package.
Supported platforms #
Currently only supports Android.
To support other platforms:

Platform specific folder must be created with default contents
Library file built from libzt must be included into corresponding platform build process inside platform folder
loader.dart must be fixed accordingly to include new platform

Usage #
For more detailed usage see example folder. Also refer to ZeroTier Sockets tutorial.
Only client TCP sockets are implemented yet.
import 'package:zerotier_sockets/zerotier_sockets.dart';
import 'package:path_provider/path_provider.dart';

Future<void> startNodeAndConnectToNetwork(String networkId) async {
// obtain node instance
var node = ZeroTierNode.instance;

// set persistent storage path to have identity and network configuration cached
// you can also use initSetIdentity to set identity from memory but network configs won't be cached
var appDocPath = (await getApplicationDocumentsDirectory()).path + '/zerotier_node';
node.initSetPath(appDocPath);

// try to start
var result = node.start();
if (!result.success) {
throw Exception('Failed to start node: $result');
}

await node.waitForOnline();

// parse network id from hex string
var nwId = BigInt.parse(networkId, radix: 16);

// join network
result = node.join(nwId);
if (!result.success) {
throw Exception('Failed to join network: $result');
}

await node.waitForNetworkReady(nwId);
await node.waitForAddressAssignment(nwId);

// get network info
var networkInfo = node.getNetworkInfo(nwId);
print(networkInfo.name);
print(networkInfo.address);
print(networkInfo.id);

ZeroTierSocket socket;
try {
// connect socket
socket = await ZeroTierSocket.connect('10.144.242.244', 22);
} catch (e) {
print('Failed to connect socket: $e');
socket.close();
return;
}

// send data
socket.sink.add([1, 2, 3, 4, 5]);

// listen for data
socket.stream.listen((data) => print('received ${data.length} byte(s)'));

// detect socket close
socket.done.then((_) => print('socket closed'));

// don't forget to close sockets
socket.close();
}
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Events #
libzt provides a way to pass a callback method that is called from background thread when an event happens.
The problem is that Dart and Flutter do not support invoking into isolate thread.
The ways to work that around:


Fork libzt and use Dart_Port as explained here


Wait for Dart team to implement calls from background threads


Platform channels can be used as well but must be implemented for each platform separately which is not ideal. Also Java API passes a limited set of events and data


In first two scenarios libzt must be built with ZTS_C_API_ONLY def, because Java callbacks will not be used.