CPE is disconnecting from Talaria due to receiving a zero-byte packet

[chaitanyasingla-dt]

We've observed an issue where, after a PPPoE reset, the CPE establishes a successful connection with Talaria but disconnects immediately. This occurs because the CPE receives a zero-byte packet from Talaria, which triggers a specific logic in the CPE that terminates the connection. However, the CPE reconnects with Talaria without any further connection breaks, and everything works smoothly after that. The issue lies in identifying the source and reason for the zero-byte packet being sent from Talaria.

cc: @Sachin4403 @schmidtw

[shilpa24balaji]

@schmidtw
From CPE side we see this log for the zero bytes packet in nopoll
We want to know the logs that can be seen in talaria when the websocket close from the CPE is received and the log where the close reason code 1000 and close message from CPE like system_restarting is seen.

PARODUS.INFO [tid=9585] PARODUS: cloud_status set as online after successful connection
PARODUS.INFO [tid=9585] PARODUS: ../../git/src/nopoll_conn.c:3321 === START: conn-id=9 (errno=0, session: 7, conn->handshake_ok: 1, conn->pending_ssl_accept: 0) ===
PARODUS.INFO [tid=9585] PARODUS: ../../git/src/nopoll_conn.c:598 SSL closed on SSL_read
PARODUS.ERROR [tid=9585] PARODUS: ../../git/src/nopoll_conn.c:2612 conn receive zero bytes, errno=0 (Success)
PARODUS.ERROR [tid=9585] PARODUS: ../../git/src/nopoll_conn.c:2619 received connection close while reading from conn id 9 (errno=0 : Success) (11, 11, 4), shutting down connection..
PARODUS.INFO [tid=9585] PARODUS: ../../git/src/nopoll_conn.c:2104 shutting down connection id=9 (session: 7, role: client)
PARODUS.INFO [tid=9585] PARODUS: Reconnect detected, setting default Reconnect reason SSL_Socket_Close

[ctorrao]

Like we talked yesterday try to test if this patch solve this issue: xmidt-org/webpa-common#439