aiohttp TLS websocket fails for continously sending packages on ESP32

Commencez par la reproduction ESP32 fournie et suivez les opérations websocket dans aiohttp_ws.py, en particulier receive, send_str, close et _read_frame, puis examinez les erreurs de asyncio/stream.py. Comparez les échecs distants et locaux, notamment le comportement de l’arrêt TLS et la croissance de la mémoire. La tâche sera considérée comme terminée lorsqu’une cause reproductible aura été identifiée et qu’un correctif vérifié aura été défini pour des messages TLS websocket continus de 2–4 kB.

@Carglglz
I have an application i want to send TLS / SSL packages over websockets using aiohttp on an ESP32. The problem is that the websockets fail after a short while when using packages that have a little bigger size around 2kB to 4kB.

Here is a simple test script:

import aiohttp
import asyncio
import gc

# allocate and prepare fixed block of data to be sent
b = bytearray(10_000)
for k in range(100):
    p = k*100
    b[p:p] = b'X'*96 + f'{k:3}' + '\n'
mv = memoryview(b)

URL = "wss://somewebsocketserver/echo"
sslctx = False
if URL.startswith("wss:"):
    try:
        import ssl
        
        sslctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
        sslctx.verify_mode = ssl.CERT_NONE
    except Exception:
        pass

async def ws_receive(ws : ClientWebSocketResponse):
    try:
        async for msg in ws:
            if msg.type != aiohttp.WSMsgType.TEXT:
                print('type:', msg.type, repr(msg.data))
    except TypeError as e:
        print('ws_receive', repr(e))
            

async def ws_test_echo(session):
    n = 1
    
    while True:
        ws_receive_task = None
        async with session.ws_connect(URL, ssl=sslctx) as ws:
            ws_receive_task = asyncio.create_task(ws_receive(ws))
            try:
                while True:
                    gc.collect()
                    print('-------------------', n, '------------------------')
                    await ws.send_str(b[0:100*n].decode())
                    n += 1

                    await asyncio.sleep_ms(100)

            except KeyboardInterrupt:
                pass

            finally:
                await ws.close()


async def main():
    async with aiohttp.ClientSession() as session:
        print('session')
        await ws_test_echo(session)


if __name__ == "__main__":
    asyncio.run(main())

remote

I'll get the following exception after a while. Just dealing with the exception is not satisfying since it takes a while and the applicaiton is blocked in that time.

Task exception wasn't retrieved
future: <Task> coro= <generator object 'ws_receive' at 3ffec850>
Traceback (most recent call last):
  File "asyncio/core.py", line 1, in run_until_complete
  File "<stdin>", line 29, in ws_receive
  File "/lib/aiohttp/aiohttp_ws.py", line 226, in __anext__
  File "/lib/aiohttp/aiohttp_ws.py", line 171, in receive
  File "/lib/aiohttp/aiohttp_ws.py", line 198, in _read_frame
  File "asyncio/stream.py", line 1, in read
OSError: -113
Traceback (most recent call last):
  File "<stdin>", line 66, in <module>
  File "asyncio/core.py", line 1, in run
  File "asyncio/core.py", line 1, in run_until_complete
  File "asyncio/core.py", line 1, in run_until_complete
  File "<stdin>", line 62, in main
  File "<stdin>", line 56, in ws_test_echo
  File "/lib/aiohttp/aiohttp_ws.py", line 233, in close
  File "/lib/aiohttp/aiohttp_ws.py", line 194, in close
  File "/lib/aiohttp/aiohttp_ws.py", line 189, in send
  File "asyncio/stream.py", line 1, in drain
OSError: -113

(OSError: 113 = ECONNABORTED)

Noteworthy is that there are always some packages that micropyhon thinks are sent already but don't reach the other side.
I also do not receive a websocket close package.
This was tested on a remote Websocket server that i don't control.

local

When i try it on a local server, i see different problems.

Traceback (most recent call last):
  File "<stdin>", line 64, in <module>
  File "asyncio/core.py", line 1, in run
  File "asyncio/core.py", line 1, in run_until_complete
  File "asyncio/core.py", line 1, in run_until_complete
  File "<stdin>", line 60, in main
  File "<stdin>", line 45, in ws_test_echo
  File "/lib/aiohttp/aiohttp_ws.py", line 239, in send_str
  File "/lib/aiohttp/aiohttp_ws.py", line 187, in send
  File "asyncio/stream.py", line 1, in write
OSError: -104

(OSError: 104 = ECONNRESET)

The servers seems to not receive the complete message / only a corrupted message and closes the connection:

...
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 37
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 38
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 39
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
b'\xe9\x82\xc3+\xe9\x82\xbbG\x81\xd0\xc3+\xe9\x82\xc3+\xe9\x82\xc3+\xe9\x82\xc3+\xe9\x82\xc3+\xe9\x82\xc3+\xe9\x82\xc3+\xe9\x82\xc3+\xe9\x82\xc3'

Unhandled exception in client_connected_cb
transport: <asyncio.sslproto._SSLProtocolTransport object at 0x7f18b780ecf0>
Traceback (most recent call last):
  File "/home/username/Documents/projects/rfid/websockets_python/microdot/examples/tls/microdot/microdot.py", line 1224, in serve
    await self.handle_request(reader, writer)
  File "/home/username/Documents/projects/rfid/websockets_python/microdot/examples/tls/microdot/microdot.py", line 1338, in handle_request
    await writer.aclose()
  File "/home/username/Documents/projects/rfid/websockets_python/microdot/examples/tls/microdot/microdot.py", line 1218, in aclose
    await self.wait_closed()
  File "/usr/lib/python3.11/asyncio/streams.py", line 364, in wait_closed
    await self._protocol._get_close_waiter(self)
  File "/usr/lib/python3.11/asyncio/sslproto.py", line 648, in _do_shutdown
    self._sslobj.unwrap()
  File "/usr/lib/python3.11/ssl.py", line 983, in unwrap
    return self._sslobj.shutdown()
           ^^^^^^^^^^^^^^^^^^^^^^^
ssl.SSLError: [SSL: APPLICATION_DATA_AFTER_CLOSE_NOTIFY] application data after close notify (_ssl.c:2706)

The closing of the websocket is also not handled properly by the micropython application / aiohttp. The close package is received but the connection is not closed automatically.

Another problem is that even if i deal with the exceptions and reconnect automatically, my application will eventually crash because of a run out of memory.
This is really problematic to me since i only send messages of size 2k or so.
I guess this is because of the not so memory economical design of aiohttp. For sending and receiving there is always a lot of new memory allocation involved.
The use of preallocation and memoryview seems reasonable here.

This is the local python websocketserver code:

import ssl
import sys
from microdot import Microdot
from microdot.websocket import with_websocket

app = Microdot()

html = '''<!DOCTYPE html>
<html>
    <head>
        <title>Microdot Example Page</title>
        <meta charset="UTF-8">
    </head>
    <body>
        <div>
            <h1>Microdot Example Page</h1>
            <p>Hello from Microdot!</p>
            <p><a href="/shutdown">Click to shutdown the server</a></p>
        </div>
    </body>
</html>
'''


@app.route('/')
async def hello(request):
    return html, 200, {'Content-Type': 'text/html'}

@app.route('/echo')
@with_websocket
async def echo(request, ws):
    while True:
        data = await ws.receive()
        print(data)
        await ws.send(data)

@app.route('/shutdown')
async def shutdown(request):
    request.app.shutdown()
    return 'The server is shutting down...'


ext = 'der' if sys.implementation.name == 'micropython' else 'pem'
folder_name = "/home/username/Documents/projects/rfid/websockets_python/"
ssl_cert = "cert.pem"
ssl_key = "key.pem"

sslctx = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
sslctx.load_cert_chain(ssl_cert, ssl_key)
app.run(port=4443, debug=True, ssl=sslctx)

MicroPython v1.23.0-preview.344.gb1ac266bb.dirty on 2024-04-29; Generic ESP32 module with ESP32