mirror of
https://github.com/zjs81/meshcore-open.git
synced 2026-06-24 11:22:57 +10:00
Enhance message parsing and error handling in MeshCoreConnector (#260)
* Enhance readString method to include Latin-1 fallback for decoding errors * Refactor _parseContactMessage to improve error handling and message parsing logic * Update lib/connector/meshcore_connector.dart Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> --------- Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
This commit is contained in:
Winston Lowe
GitHub
@@ -2459,70 +2459,93 @@ class MeshCoreConnector extends ChangeNotifier {
|
||||
}
|
||||
|
||||
Message? _parseContactMessage(Uint8List frame) {
|
||||
if (frame.isEmpty) return null;
|
||||
final code = frame[0];
|
||||
if (code != respCodeContactMsgRecv && code != respCodeContactMsgRecvV3) {
|
||||
if (frame.isEmpty) {
|
||||
appLogger.warn('Received empty frame, ignoring');
|
||||
return null;
|
||||
}
|
||||
final reader = BufferReader(frame);
|
||||
|
||||
// Companion radio layout:
|
||||
// [code][snr?][res?][res?][prefix x6][path_len][txt_type][timestamp x4][extra?][text...]
|
||||
final prefixOffset = code == respCodeContactMsgRecvV3 ? 4 : 1;
|
||||
const prefixLen = 6;
|
||||
final pathLenOffset = prefixOffset + prefixLen;
|
||||
final txtTypeOffset = pathLenOffset + 1;
|
||||
final timestampOffset = txtTypeOffset + 1;
|
||||
final baseTextOffset = timestampOffset + 4;
|
||||
try {
|
||||
final code = reader.readByte();
|
||||
if (code != respCodeContactMsgRecv && code != respCodeContactMsgRecvV3) {
|
||||
appLogger.warn(
|
||||
'Unexpected message code: $code, expected contact message receive codes',
|
||||
);
|
||||
return null;
|
||||
}
|
||||
|
||||
if (frame.length <= baseTextOffset) return null;
|
||||
final fourBytePubMSG = frame.sublist(baseTextOffset, baseTextOffset + 4);
|
||||
final senderPrefix = frame.sublist(prefixOffset, prefixOffset + prefixLen);
|
||||
final flags = frame[txtTypeOffset];
|
||||
final shiftedType = flags >> 2;
|
||||
final rawType = flags;
|
||||
final isPlain = shiftedType == txtTypePlain || rawType == txtTypePlain;
|
||||
final isCli = shiftedType == txtTypeCliData || rawType == txtTypeCliData;
|
||||
if (!isPlain && !isCli) {
|
||||
return null;
|
||||
}
|
||||
// Companion radio layout:
|
||||
// [code][snr?][res?][res?][prefix x6][path_len][txt_type][timestamp x4][extra?][text...]
|
||||
// double snr = 0;
|
||||
if (code == respCodeContactMsgRecvV3) {
|
||||
// Older firmware layout with SNR as a signed byte after the code
|
||||
// snr = reader.readInt8().toDouble() * 4; // SNR in dB, scaled by 4
|
||||
reader.skipBytes(1); // Skip SNR byte
|
||||
reader.skipBytes(2); // Skip reserved bytes
|
||||
}
|
||||
|
||||
// Try base text offset; if empty and there is room for the optional 4-byte extra
|
||||
// (used by signed/plain variants), try again skipping those bytes.
|
||||
var text = readCString(
|
||||
frame,
|
||||
baseTextOffset,
|
||||
frame.length - baseTextOffset,
|
||||
);
|
||||
if (text.isEmpty && frame.length > baseTextOffset + 4) {
|
||||
text = readCString(
|
||||
frame,
|
||||
baseTextOffset + 4,
|
||||
frame.length - (baseTextOffset + 4),
|
||||
final senderPrefix = reader.readBytes(6);
|
||||
final pathLength = reader.readByte();
|
||||
final txtType = reader.readByte();
|
||||
final timestampRaw = reader.readUInt32LE();
|
||||
final timestamp = DateTime.fromMillisecondsSinceEpoch(
|
||||
timestampRaw * 1000,
|
||||
);
|
||||
|
||||
if (txtType == 2) {
|
||||
reader.skipBytes(4); // Skip extra 4 bytes for signed/plain variants
|
||||
}
|
||||
|
||||
final msgText = reader.readString();
|
||||
|
||||
final flags = txtType;
|
||||
final shiftedType = flags >> 2;
|
||||
final rawType = flags;
|
||||
final isPlain = shiftedType == txtTypePlain || rawType == txtTypePlain;
|
||||
final isCli = shiftedType == txtTypeCliData || rawType == txtTypeCliData;
|
||||
if (!isPlain && !isCli) {
|
||||
appLogger.warn(
|
||||
'Unknown message type received: txtType=$txtType, shifted=$shiftedType, raw=$rawType',
|
||||
);
|
||||
return null;
|
||||
}
|
||||
|
||||
if (msgText.isEmpty) {
|
||||
appLogger.warn('Received message with empty text, ignoring');
|
||||
return null;
|
||||
}
|
||||
final decodedText = isCli
|
||||
? msgText
|
||||
: (Smaz.tryDecodePrefixed(msgText) ?? msgText);
|
||||
|
||||
final contact = _contacts.cast<Contact?>().firstWhere(
|
||||
(c) => c != null && _matchesPrefix(c.publicKey, senderPrefix),
|
||||
orElse: () => null,
|
||||
);
|
||||
if (contact == null) {
|
||||
appLogger.warn(
|
||||
'Received message from unknown contact with prefix: ${senderPrefix.map((b) => b.toRadixString(16).padLeft(2, '0').toUpperCase()).join('')}',
|
||||
);
|
||||
return null;
|
||||
}
|
||||
|
||||
return Message(
|
||||
senderKey: contact.publicKey,
|
||||
text: decodedText,
|
||||
timestamp: timestamp,
|
||||
isOutgoing: false,
|
||||
isCli: isCli,
|
||||
status: MessageStatus.delivered,
|
||||
pathLength: pathLength == 0xFF ? 0 : pathLength,
|
||||
pathBytes: Uint8List(0),
|
||||
fourByteRoomContactKey: msgText.length >= 4
|
||||
? Uint8List.fromList(msgText.substring(0, 4).codeUnits)
|
||||
: null,
|
||||
);
|
||||
} catch (e) {
|
||||
appLogger.warn('Error parsing contact direct message: $e');
|
||||
return null;
|
||||
}
|
||||
if (text.isEmpty) return null;
|
||||
final decodedText = isCli ? text : (Smaz.tryDecodePrefixed(text) ?? text);
|
||||
|
||||
final timestampRaw = readUint32LE(frame, timestampOffset);
|
||||
final pathLenByte = frame[pathLenOffset];
|
||||
|
||||
final contact = _contacts.cast<Contact?>().firstWhere(
|
||||
(c) => c != null && _matchesPrefix(c.publicKey, senderPrefix),
|
||||
orElse: () => null,
|
||||
);
|
||||
if (contact == null) return null;
|
||||
|
||||
return Message(
|
||||
senderKey: contact.publicKey,
|
||||
text: decodedText,
|
||||
timestamp: DateTime.fromMillisecondsSinceEpoch(timestampRaw * 1000),
|
||||
isOutgoing: false,
|
||||
isCli: isCli,
|
||||
status: MessageStatus.delivered,
|
||||
pathLength: pathLenByte == 0xFF ? 0 : pathLenByte,
|
||||
pathBytes: Uint8List(0),
|
||||
fourByteRoomContactKey: fourBytePubMSG,
|
||||
);
|
||||
}
|
||||
|
||||
bool _matchesPrefix(Uint8List fullKey, Uint8List prefix) {
|
||||
|
||||
@@ -34,8 +34,14 @@ class BufferReader {
|
||||
|
||||
Uint8List readRemainingBytes() => readBytes(remaining);
|
||||
|
||||
String readString() =>
|
||||
utf8.decode(readRemainingBytes(), allowMalformed: true);
|
||||
String readString() {
|
||||
final value = readRemainingBytes();
|
||||
try {
|
||||
return utf8.decode(Uint8List.fromList(value), allowMalformed: true);
|
||||
} catch (e) {
|
||||
return String.fromCharCodes(value); // Latin-1 fallback
|
||||
}
|
||||
}
|
||||
|
||||
String readCString(int maxLength) {
|
||||
final value = <int>[];
|
||||
|
||||
Reference in New Issue
Block a user