Function proxyToDevice

ios-qa/daemon/src/proxy.ts:30–90

(opts: {
  inbound: IncomingMessage;
  body: Buffer;
  tunnel: DeviceTunnel;
  sessionId: string | null;
  agentIdentity?: string;
})

 * response or a ProxyError. Caller writes to the ServerResponse.
 */
export async function proxyToDevice(opts: {
  inbound: IncomingMessage;
  body: Buffer;
  tunnel: DeviceTunnel;
  sessionId: string | null;
  agentIdentity?: string;
}): Promise<{ status: number; headers: Record<string, string>; body: Buffer }> {
  const { inbound, body, tunnel, sessionId, agentIdentity } = opts;
  if (body.length > MAX_BODY) {
    return makeError(413, 'body_too_large');
  }

  const headers: Record<string, string> = {
    'authorization': `Bearer ${tunnel.bootTokenRotated}`,
    'content-type': inbound.headers['content-type'] || 'application/json',
    'content-length': String(body.length),
  };
  if (sessionId) headers['x-session-id'] = sessionId;
  if (agentIdentity) headers['x-agent-identity'] = agentIdentity;

  // Bracket IPv6 literals; pass IPv4 + hostnames bare. The CoreDevice tunnel
  // is always IPv6 in production, but tests inject 127.0.0.1 to talk to a
  // local stub. Detect by `:` count (IPv6 has multiple colons) or `:` absence
  // (IPv4/hostname).
  const isIPv6 = (tunnel.ipv6Addr.match(/:/g)?.length ?? 0) >= 2;
  const hostPart = isIPv6 ? `[${tunnel.ipv6Addr}]` : tunnel.ipv6Addr;
  const url = `http://${hostPart}:${tunnel.port}${inbound.url ?? '/'}`;
  return new Promise((resolve, reject) => {
    const req = httpRequest(url, {
      method: inbound.method,
      headers,
      timeout: 30_000,
    }, (res) => {
      const chunks: Buffer[] = [];
      res.on('data', (c) => chunks.push(c));
      res.on('end', () => {
        const respHeaders: Record<string, string> = {};
        for (const [k, v] of Object.entries(res.headers)) {
          if (typeof v === 'string') respHeaders[k] = v;
        }
        resolve({
          status: res.statusCode ?? 502,
          headers: respHeaders,
          body: Buffer.concat(chunks),
        });
      });
    });
    req.on('error', (err) => {
      const e = err as { code?: string };
      if (e.code === 'ECONNREFUSED' || e.code === 'EHOSTUNREACH') {
        resolve(makeError(503, 'device_disconnected'));
      } else if (e.code === 'ETIMEDOUT') {
        resolve(makeError(504, 'upstream_timeout'));
      } else {
        reject(err);
      }
    });
    req.write(body);