CVSROOT: /cvs
Module name: src
Changes by: clau...@cvs.openbsd.org 2020/12/23 06:20:48
Modified files:
usr.sbin/bgpd : bgpd.h session.c session.h
Log message:
BGP uses KEEPALIVE packets and the HOLD timer to detect stalled sessions.
The problem is that this timer only looks at the receive side of the TCP
session. If for some reason the send side stalls the system fully depends
on the remote BGP peer to reset the session. As seen in an ever growing
OutQ and as a result important changes can get stalled and cause routing
troubles.
This change introduces a SEND HOLD timer. The timer is reset whenever the
session engine was able to write data to the TCP socket. If the send hold
timer expires bgpd was not able to send any data to that neighbor for at
least 90 seconds and therefor the session is forcefully closed with a hold
timer expired notification.
The send hold timer acts as a last resort to detect faulty peers. On an
idle session it can take a long time until this timer triggers but the
main goal here is to reset a stuck session at some point which did not
happen before.
With and OK job@
