blockTCPPort method

@override Future<bool> blockTCPPort(int port, { bool sudo = false, required Set<int>? allowedPorts, required bool allowAllPorts, })

Blocks a specific TCP port.

• port: The TCP port to be blocked.
• sudo: A flag indicating if sudo privileges should be used. Defaults to false.
• allowedPorts: A set of allowed ports. Ignored if allowAllPorts is true.
• allowAllPorts: A flag indicating if all ports should be allowed.

Returns a Future that completes with true if the port was successfully blocked, or false if it failed.

Implementation

@override
Future<bool> blockTCPPort(int port,
    {bool sudo = false,
    required Set<int>? allowedPorts,
    required bool allowAllPorts}) async {
  _checkValidPort(port);

  if (!allowAllPorts &&
      (allowedPorts == null || !allowedPorts.contains(port))) {
    return false;
  }

  // Block on every available family so the port is actually closed for both
  // IPv4 and IPv6 traffic.
  final bins = await _resolveFirewallBinaries();

  var allOk = true;
  for (final bin in bins) {
    var output = await runCommand(
      bin,
      <String>['-A', 'INPUT', '-p', 'tcp', '--dport', '$port', '-j', 'DROP'],
      sudo: sudo,
      expectedExitCode: 0,
    );

    if (output == null) allOk = false;
  }

  if (!allOk) {
    return false;
  }

  var blocked = await isBlockedTCPPort(port,
      sudo: sudo, allowedPorts: allowAllPorts ? null : (allowedPorts ?? {}));
  return blocked;
}