lib: Add FIN and receive-side linger for msg deallocbe

qos_msg flows had no end-of-stream signal: a deallocating sender
relied on the peer's inactivity timers (~30 s) to notice. Worse, the
dealloc-linger path was bugged: a receiver that called flow_dealloc
would stop draining its rx_rb while the peer's tail retransmits kept
arriving. Peer retransmitted into a black hole until its own dealloc
fired, and the whole shutdown stretched takes t_a time.

Generalizes frcti_stream_fin_snd to frcti_fin_snd; for msg mode emit a
FRCT_FIN-only control packet with the FIN seqno boundary in
pci->ackno. Receiver-side frcti_rcv latches rcv_fin_seen and stores
the boundary on FRCT_FIN-without-DATA.

Fix comment on the FRCT flags.

Signed-off-by: Dimitri Staessens <dimitri@ouroboros.rocks>
Signed-off-by: Sander Vrijders <sander@ouroboros.rocks>

0 files changed, 0 insertions, 0 deletions