Function parseVLESSHeader

cfworker/worker.js:140–180

* Parse the VLESS header from the first chunk. Returns {ok, host, port, payload}. * VLESS v1 layout (simplified): * [0] version (1 byte) * [1-16] uuid (16 bytes) * [17] addons length N (1 byte) * [18..18+N] addons * [+1] command (1=TCP, 2=UDP) * [+2] port (big-endia

(buf, expectedUUID)

 *   [..]    payload
 */
function parseVLESSHeader(buf, expectedUUID) {
  try {
    if (buf.length < 18) return { ok: false, err: "too short" };
    const version = buf[0];
    const uuidBytes = buf.slice(1, 17);
    const got = uuidToStr(uuidBytes);
    if (got !== expectedUUID) return { ok: false, err: "uuid mismatch" };
    const addonsLen = buf[17];
    let i = 18 + addonsLen;
    if (buf.length < i + 4) return { ok: false, err: "truncated" };
    const cmd = buf[i++];
    if (cmd !== 1) return { ok: false, err: "unsupported command (UDP/Mux not handled)" };
    const port = (buf[i] << 8) | buf[i + 1];
    i += 2;
    const addrType = buf[i++];
    let host;
    if (addrType === 1) {
      // IPv4: 4 bytes.
      if (buf.length < i + 4) return { ok: false, err: "truncated ipv4" };
      host = `${buf[i]}.${buf[i + 1]}.${buf[i + 2]}.${buf[i + 3]}`;
      i += 4;
    } else if (addrType === 2) {
      // Domain: 1-byte length prefix + name.
      if (buf.length < i + 1) return { ok: false, err: "truncated domain len" };
      const len = buf[i++];
      if (buf.length < i + len) return { ok: false, err: "truncated domain" };
      host = new TextDecoder().decode(buf.slice(i, i + len));
      i += len;
    } else if (addrType === 3) {
      // IPv6: 16 bytes.
      if (buf.length < i + 16) return { ok: false, err: "truncated ipv6" };
      host = ipv6ToStr(buf.slice(i, i + 16));
      i += 16;
    } else {
      return { ok: false, err: `unknown addr type ${addrType}` };
    }
    return { ok: true, version, host, port, payload: buf.slice(i) };
  } catch (e) {
    return { ok: false, err: e.message };
  }
}

// Cloudflare-specific outbound TCP via the `connect` API.
async function cfConnect(host, port) {