meshcore-open/lib/services/linux_ble_pairing_service.dart

423 lines
13 KiB
Dart

import 'dart:async';
import 'dart:convert';
import 'dart:io';
typedef ProcessStartFn =
Future<Process> Function(String executable, List<String> arguments);
typedef ProcessRunFn =
Future<ProcessResult> Function(String executable, List<String> arguments);
/// Best-effort Linux BLE pairing helper using bluetoothctl.
///
/// This is used only as a fallback when BlueZ pairing via flutter_blue_plus
/// fails to surface agent prompts in-app.
class LinuxBlePairingService {
/// Maximum number of pairing attempts (initial + retries).
/// Covers one remove-and-retry plus one proactive-PIN retry.
static const int _maxAttempts = 3;
static const Duration _processExitTimeout = Duration(seconds: 6);
static const Duration _pairingCleanupTimeout = Duration(seconds: 5);
static const Duration _defaultPairingTimeout = Duration(seconds: 45);
LinuxBlePairingService({
ProcessStartFn? processStart,
ProcessRunFn? processRun,
}) : _processStart = processStart ?? Process.start,
_processRun = processRun ?? Process.run;
final ProcessStartFn _processStart;
final ProcessRunFn _processRun;
Future<bool> isBluetoothctlAvailable() async {
try {
final result = await _processRun('bluetoothctl', <String>['--version']);
return result.exitCode == 0;
} on ProcessException {
return false;
}
}
Future<void> disconnectDevice(
String remoteId, {
void Function(String message)? onLog,
}) async {
onLog?.call('Requesting BlueZ disconnect for $remoteId');
Process process;
try {
process = await _processStart('bluetoothctl', <String>[]);
} on ProcessException catch (error) {
onLog?.call(
'bluetoothctl unavailable, skipping BlueZ disconnect: $error',
);
return;
}
process.stdin.writeln('disconnect $remoteId');
process.stdin.writeln('quit');
try {
await process.exitCode.timeout(_processExitTimeout);
} catch (_) {
process.kill();
}
onLog?.call('Issued bluetoothctl disconnect for $remoteId');
}
Future<bool> isPairedAndTrusted(String remoteId) async {
ProcessResult result;
try {
result = await _processRun('bluetoothctl', <String>['info', remoteId]);
} on ProcessException {
return false;
}
if (result.exitCode != 0) {
return false;
}
final output = (result.stdout as String).toLowerCase();
return output.contains('paired: yes') && output.contains('trusted: yes');
}
Future<bool> trustDevice(
String remoteId, {
void Function(String message)? onLog,
}) async {
onLog?.call('Requesting BlueZ trust for $remoteId');
ProcessResult result;
try {
result = await _processRun('bluetoothctl', <String>['trust', remoteId]);
} on ProcessException catch (error) {
onLog?.call('bluetoothctl unavailable, cannot trust $remoteId: $error');
return false;
}
if (result.exitCode != 0) {
onLog?.call('bluetoothctl trust failed for $remoteId: ${result.stderr}');
return false;
}
final trusted = await isPairedAndTrusted(remoteId);
onLog?.call(
trusted
? 'Verified BlueZ trust for $remoteId'
: 'BlueZ trust verification failed for $remoteId',
);
return trusted;
}
Future<bool> pairAndTrust({
required String remoteId,
Duration timeout = _defaultPairingTimeout,
void Function(String message)? onLog,
Future<String?> Function()? onRequestPin,
}) async {
var removeRetryUsed = false;
var proactivePinRetryUsed = false;
Future<String?> Function()? currentPinProvider = onRequestPin;
for (var attempt = 0; attempt < _maxAttempts; attempt++) {
final result = await _runPairingAttempt(
remoteId: remoteId,
timeout: timeout,
onLog: onLog,
onRequestPin: currentPinProvider,
);
if (result.success) return true;
if (result.userCancelled) {
onLog?.call('Pairing cancelled by user; skipping retry/remove flow');
return false;
}
if (result.pairFailed) {
if (!removeRetryUsed) {
removeRetryUsed = true;
onLog?.call(
'Pairing failed; removing cached bond and retrying '
'(attempt ${attempt + 1}/$_maxAttempts)',
);
await _removeDevice(remoteId, onLog: onLog);
continue;
}
if (!result.pinSent &&
!proactivePinRetryUsed &&
currentPinProvider != null) {
proactivePinRetryUsed = true;
onLog?.call(
'Pairing failed before PIN challenge; requesting PIN for '
'proactive retry (attempt ${attempt + 1}/$_maxAttempts)',
);
final pin = await currentPinProvider();
if (pin == null) {
onLog?.call('PIN entry cancelled for proactive retry');
return false;
}
final capturedPin = pin.trim();
currentPinProvider = () async => capturedPin;
continue;
}
return false;
}
// Timeout path — pairing neither succeeded nor failed.
onLog?.call('Pairing did not complete before timeout');
if (!result.pinSent &&
!proactivePinRetryUsed &&
currentPinProvider != null) {
proactivePinRetryUsed = true;
onLog?.call(
'No PIN challenge observed before timeout; requesting PIN for '
'proactive retry (attempt ${attempt + 1}/$_maxAttempts)',
);
final pin = await currentPinProvider();
if (pin == null) {
onLog?.call('PIN entry cancelled for proactive retry after timeout');
return false;
}
final capturedPin = pin.trim();
currentPinProvider = () async => capturedPin;
continue;
}
return false;
}
return false;
}
/// Runs a single bluetoothctl pairing attempt.
///
/// Uses a [Completer] to wake as soon as pairing succeeds or fails,
/// instead of polling.
Future<_PairingResult> _runPairingAttempt({
required String remoteId,
required Duration timeout,
void Function(String message)? onLog,
Future<String?> Function()? onRequestPin,
}) async {
onLog?.call('Starting bluetoothctl pairing flow for $remoteId');
Process process;
try {
process = await _processStart('bluetoothctl', <String>[]);
} on ProcessException catch (error) {
onLog?.call('bluetoothctl unavailable, cannot run pairing flow: $error');
return const _PairingResult();
}
final output = StringBuffer();
var pinSent = false;
var sessionClosed = false;
var userCancelledPinEntry = false;
var confirmationHandled = false;
var successHandled = false;
var failureHandled = false;
var detectorBuffer = '';
final pairingDone = Completer<void>();
var pairSucceeded = false;
var pairFailed = false;
void writeCmd(String cmd) {
if (sessionClosed) return;
try {
process.stdin.writeln(cmd);
} on StateError {
sessionClosed = true;
onLog?.call('bluetoothctl stdin already closed; ignoring "$cmd"');
}
}
unawaited(
process.exitCode.then((_) {
sessionClosed = true;
if (!pairingDone.isCompleted) pairingDone.complete();
}),
);
void handleChunk(String chunk) {
output.write(chunk);
detectorBuffer += chunk.toLowerCase();
if (detectorBuffer.length > 4096) {
detectorBuffer = detectorBuffer.substring(detectorBuffer.length - 4096);
}
final lower = detectorBuffer;
if (!pinSent &&
!sessionClosed &&
(lower.contains('enter pin code') ||
lower.contains('requestpin') ||
lower.contains('input pin code') ||
lower.contains('request passkey') ||
lower.contains('requestpasskey') ||
lower.contains('enter passkey'))) {
pinSent = true;
if (onRequestPin == null) {
onLog?.call(
'PIN/passkey requested but no onRequestPin callback; '
'sending empty line to accept default pairing',
);
writeCmd('');
} else {
onLog?.call('Pairing agent is ready for PIN/passkey input');
unawaited(
Future<void>(() async {
String? pin;
try {
pin = await onRequestPin();
} catch (e) {
onLog?.call('onRequestPin callback threw: $e');
pairFailed = true;
writeCmd('cancel');
if (!pairingDone.isCompleted) pairingDone.complete();
return;
}
if (pin == null) {
if (sessionClosed) {
onLog?.call(
'PIN prompt resolved after pairing session closed',
);
return;
}
onLog?.call('PIN entry cancelled by user; cancelling pairing');
userCancelledPinEntry = true;
pairFailed = true;
writeCmd('cancel');
if (!pairingDone.isCompleted) pairingDone.complete();
return;
}
if (sessionClosed) {
onLog?.call(
'PIN provided after pairing session closed; ignoring',
);
return;
}
if (pin.trim().isEmpty) {
onLog?.call(
'Blank PIN submitted; sending empty line to accept default pairing',
);
writeCmd('');
} else {
onLog?.call('Submitting PIN/passkey to pairing agent');
writeCmd(pin.trim());
}
}),
);
}
}
if (!confirmationHandled &&
(lower.contains('confirm passkey') ||
lower.contains('requestconfirmation') ||
lower.contains('[agent] confirm'))) {
confirmationHandled = true;
onLog?.call(
'Pairing agent requested passkey confirmation; answering yes',
);
writeCmd('yes');
}
if (!successHandled &&
(lower.contains('pairing successful') ||
lower.contains('already paired'))) {
successHandled = true;
onLog?.call('Pairing reported success');
pairSucceeded = true;
if (!pairingDone.isCompleted) pairingDone.complete();
}
if (!failureHandled &&
(lower.contains('failed to pair') ||
lower.contains('authenticationfailed') ||
lower.contains('authentication failed'))) {
failureHandled = true;
onLog?.call('Pairing reported authentication failure');
pairFailed = true;
if (!pairingDone.isCompleted) pairingDone.complete();
}
}
final stdoutSub = process.stdout
.transform(utf8.decoder)
.listen(handleChunk);
final stderrSub = process.stderr
.transform(utf8.decoder)
.listen(handleChunk);
writeCmd('power on');
writeCmd('agent KeyboardDisplay');
writeCmd('default-agent');
onLog?.call('Waiting for pairing challenge from bluetoothctl agent');
writeCmd('pair $remoteId');
// Wait for the Completer to fire (success/failure/process exit) or timeout.
await pairingDone.future.timeout(timeout, onTimeout: () {});
if (!pairFailed && pairSucceeded) {
onLog?.call('Pair succeeded; trusting and connecting device');
writeCmd('trust $remoteId');
writeCmd('connect $remoteId');
}
writeCmd('quit');
sessionClosed = true;
try {
await process.exitCode.timeout(_pairingCleanupTimeout);
} catch (_) {
process.kill();
}
await stdoutSub.cancel();
await stderrSub.cancel();
if (pairFailed) {
return _PairingResult(
pairFailed: true,
pinSent: pinSent,
userCancelled: userCancelledPinEntry,
);
}
final allOutput = output.toString().toLowerCase();
final reportedSuccess =
pairSucceeded ||
allOutput.contains('pairing successful') ||
allOutput.contains('already paired');
if (reportedSuccess) {
final trusted = await trustDevice(remoteId, onLog: onLog);
if (!trusted) {
onLog?.call('Pairing completed but BlueZ trust was not restored');
}
return _PairingResult(success: trusted, pinSent: pinSent);
}
return _PairingResult(pinSent: pinSent);
}
Future<void> _removeDevice(
String remoteId, {
void Function(String message)? onLog,
}) async {
Process process;
try {
process = await _processStart('bluetoothctl', <String>[]);
} on ProcessException catch (error) {
onLog?.call(
'bluetoothctl unavailable, skipping remove for $remoteId: $error',
);
return;
}
process.stdin.writeln('remove $remoteId');
process.stdin.writeln('quit');
try {
await process.exitCode.timeout(_processExitTimeout);
} catch (_) {
process.kill();
}
onLog?.call('Issued bluetoothctl remove for $remoteId');
}
}
/// Outcome of a single bluetoothctl pairing attempt.
class _PairingResult {
final bool success;
final bool pairFailed;
final bool pinSent;
final bool userCancelled;
const _PairingResult({
this.success = false,
this.pairFailed = false,
this.pinSent = false,
this.userCancelled = false,
});
}