Previously, during local flow migration the current connection context
was not part of the migration and would cause the flow to still be listening
on the connection context of the old connection (before the migration).
This meant that if a flow was migrated from connection 0 to
connection 1, and connection 0 goes away, the flow would be early
terminated incorrectly with the context lifetime of connection 0.
The new connection context is provided during migration of a flow
and will trigger the observe loop for the flow lifetime to be rebound
to this provided context.
Closes TUN-8748
To help reduce the volume of logs during the happy path of flow registration, there will only be one log message reported when a flow is completed.
There are additional fields added to all flow log messages:
1. `src`: local address
2. `dst`: origin address
3. `durationMS`: capturing the total duration of the flow in milliseconds
Additional logs were added to capture when a flow was migrated or when cloudflared sent off a registration response retry.
Closes TUN-8701
When a registration response from cloudflared gets lost on it's way back to the edge, the edge service will retry and send another registration request. Since cloudflared already has bound the local UDP socket for the provided request id, we want to re-send the registration response.
There are three types of retries that the edge will send:
1. A retry from the same QUIC connection index; cloudflared will just respond back with a registration response and reset the idle timer for the session.
2. A retry from a different QUIC connection index; cloudflared will need to migrate the current session connection to this new QUIC connection and reset the idle timer for the session.
3. A retry to a different cloudflared connector; cloudflared will eventually time the session out since no further packets will arrive to the session at the original connector.
Closes TUN-8709
New session manager leverages similar functionality that was previously
provided with datagram v2, with the distinct difference that the sessions
are registered via QUIC Datagrams and unregistered via timeouts only; the
sessions will no longer attempt to unregister sessions remotely with the
edge service.
The Session Manager is shared across all QUIC connections that cloudflared
uses to connect to the edge (typically 4). This will help cloudflared be
able to monitor all sessions across the connections and help correlate
in the future if sessions migrate across connections.
The UDP payload size is still limited to 1280 bytes across all OS's. Any
UDP packet that provides a payload size of greater than 1280 will cause
cloudflared to report (as it currently does) a log error and drop the packet.
Closes TUN-8667
Devin Carr
Gonçalo Garcia