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Fix VICE protocol: 1-byte request ID, correct header sizes

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Per KB docs, the actual protocol format is:
- Request: STX(1) + API(1) + Length(4) + ReqID(1) + Cmd(1) + Body (header = 8)
- Response: STX(1) + API(1) + Length(4) + Type(1) + Error(1) + ReqID(1) + Body (header = 9)

Previous fix incorrectly used 4-byte request IDs. Also added debug
logging to stderr to help diagnose protocol issues.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
This commit is contained in:
Simen Svale 2025-12-30 02:47:49 +01:00
parent 3fece5cb1e
commit 0a6982ae40
1 changed files with 34 additions and 13 deletions
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47
src/protocol/client.ts
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@ -33,6 +33,19 @@ export interface CheckpointInfo {
// Keep for backwards compatibility
export type BreakpointInfo = CheckpointInfo;
// Debug logging - set to true to see protocol traffic
const DEBUG = true;
function debugLog(msg: string, data?: Buffer | unknown): void {
if (!DEBUG) return;
if (data instanceof Buffer) {
console.error(`[VICE] ${msg}: ${data.toString("hex")} (${data.length} bytes)`);
} else if (data !== undefined) {
console.error(`[VICE] ${msg}:`, data);
} else {
console.error(`[VICE] ${msg}`);
}
}
export class ViceClient {
private socket: Socket | null = null;
private requestId = 0;
@ -146,25 +159,29 @@ export class ViceClient {
}
private nextRequestId(): number {
this.requestId = (this.requestId + 1) & 0xffffffff;
this.requestId = (this.requestId + 1) & 0xff;
return this.requestId;
}
private handleData(data: Buffer): void {
this.responseBuffer = Buffer.concat([this.responseBuffer, data]);
debugLog("Received data", data);
// Process complete packets
// Response header: STX(1) + API(1) + bodyLength(4) + responseType(1) + errorCode(1) + requestId(4) = 12 bytes
while (this.responseBuffer.length >= 12) {
// Response header: STX(1) + API(1) + bodyLength(4) + responseType(1) + errorCode(1) + requestId(1) = 9 bytes
while (this.responseBuffer.length >= 9) {
const stx = this.responseBuffer[0];
if (stx !== STX) {
// Protocol error, skip byte
debugLog(`Skipping non-STX byte: 0x${stx.toString(16)}`);
this.responseBuffer = this.responseBuffer.subarray(1);
continue;
}
const bodyLength = this.responseBuffer.readUInt32LE(2);
const totalLength = 12 + bodyLength; // Header (12) + body
const totalLength = 6 + bodyLength; // Header prefix (6) + body (which includes type, error, reqId)
debugLog(`Packet: bodyLength=${bodyLength}, totalLength=${totalLength}, bufferLen=${this.responseBuffer.length}`);
if (this.responseBuffer.length < totalLength) {
// Wait for more data
@ -172,11 +189,14 @@ export class ViceClient {
}
// Parse complete packet
// Response format: STX(1) + API(1) + bodyLen(4) + type(1) + error(1) + reqId(4) + body
// Response format: STX(1) + API(1) + bodyLen(4) + type(1) + error(1) + reqId(1) + body
const responseType = this.responseBuffer[6] as ResponseType;
const errorCode = this.responseBuffer[7] as ErrorCode;
const requestId = this.responseBuffer.readUInt32LE(8);
const body = this.responseBuffer.subarray(12, totalLength);
const requestId = this.responseBuffer[8];
const body = this.responseBuffer.subarray(9, totalLength);
debugLog(`Parsed response: type=0x${responseType.toString(16)}, error=0x${errorCode.toString(16)}, reqId=${requestId}`);
debugLog("Response body", body);
const response: ViceResponse = {
responseType,
@ -251,16 +271,17 @@ export class ViceClient {
const requestId = this.nextRequestId();
// Build packet: STX(1) + API(1) + Length(4) + RequestID(4) + Command(1) + Body
// Length field includes: RequestID(4) + Command(1) + Body
const header = Buffer.alloc(11);
// Build packet: STX(1) + API(1) + Length(4) + RequestID(1) + Command(1) + Body
// Length field includes: RequestID(1) + Command(1) + Body
const header = Buffer.alloc(8);
header[0] = STX;
header[1] = API_VERSION;
header.writeUInt32LE(body.length + 5, 2); // Body length includes request ID (4) and command (1)
header.writeUInt32LE(requestId, 6);
header[10] = command;
header.writeUInt32LE(body.length + 2, 2); // Body length includes request ID (1) and command (1)
header[6] = requestId;
header[7] = command;
const packet = Buffer.concat([header, body]);
debugLog(`Sending command 0x${command.toString(16)}, reqId=${requestId}`, packet);
return new Promise((resolve, reject) => {
this.pendingRequests.set(requestId, { resolve, reject });