初始提交：DSH 多租户平台（dshs）

poc/02-socat-ws/fake-dsh.mjs

@@ -0,0 +1,60 @@
+// Minimal fake DSH for the socat-WS PoC: plain HTTP on 127.0.0.1:8080 plus a
+// WebSocket echo (handshake + one text-frame round-trip) using only node built-ins.
+import { createServer } from 'node:http'
+import { createHash } from 'node:crypto'
+
+const GUID = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
+const acceptKey = (key) => createHash('sha1').update(key + GUID).digest('base64')
+
+const server = createServer((req, res) => {
+  res.writeHead(200, { 'Content-Type': 'text/plain' })
+  res.end('fake-dsh\n')
+})
+
+server.on('upgrade', (req, socket) => {
+  const key = req.headers['sec-websocket-key']
+  if (!key) {
+    socket.destroy()
+    return
+  }
+  socket.write(
+    'HTTP/1.1 101 Switching Protocols\r\n' +
+      'Upgrade: websocket\r\n' +
+      'Connection: Upgrade\r\n' +
+      `Sec-WebSocket-Accept: ${acceptKey(key)}\r\n\r\n`,
+  )
+  socket.on('data', (buf) => {
+    const opcode = buf[0] & 0x0f
+    if (opcode === 0x8) {
+      socket.end()
+      return
+    }
+    if (opcode !== 0x1 && opcode !== 0x2) return
+    const masked = (buf[1] & 0x80) !== 0
+    let len = buf[1] & 0x7f
+    let offset = 2
+    if (len === 126) {
+      len = buf.readUInt16BE(2)
+      offset = 4
+    } else if (len === 127) {
+      return // not exercised in the PoC
+    }
+    let maskKey
+    if (masked) {
+      maskKey = buf.subarray(offset, offset + 4)
+      offset += 4
+    }
+    const payload = Buffer.from(buf.subarray(offset, offset + len))
+    if (masked && maskKey) {
+      for (let i = 0; i < payload.length; i++) payload[i] ^= maskKey[i % 4]
+    }
+    // Echo back as an unmasked text frame.
+    const out = Buffer.alloc(2 + payload.length)
+    out[0] = 0x81
+    out[1] = payload.length
+    payload.copy(out, 2)
+    socket.write(out)
+  })
+})
+
+server.listen(8080, '127.0.0.1', () => console.log('fake-dsh listening on 127.0.0.1:8080'))