fix graceful-restart when not all peers are restarting

This fixes an issue where GoBGP would incorrectly defer sending routes to a peer on a graceful restart.
RFC4724 states:

> Once the session between the Restarting Speaker and the Receiving
> Speaker is re-established, the Restarting Speaker will receive and
> process BGP messages from its peers.  However, it MUST defer route
> selection for an address family until it either (a) receives the
> End-of-RIB marker from all its peers (excluding the ones with the
> "Restart State" bit set in the received capability and excluding the
> ones that do not advertise the graceful restart capability) or (b)
> the Selection_Deferral_Timer referred to below has expired.

The scenario that this fixes is where you have 3 (or more) peers, and 2 of the peers ("A" and "B") perform a graceful restart at the same time, but the 3rd ("C") does not. If after restart peer C sends EOR to peer A before peer B reaches BGP_FSM_ESTABLISHED with peer A, it defers the route selection. However once peer B does reach BGP_FSM_ESTABLISHED, peer A still wouldn't send any updates to peer C until the deferral expired.

This commit changes the behavior so that upon restart, once the peer receives EOR from all non-restarting peers and reaches BGP_FSM_ESTABLISHED for all restarting peers, the routes are sent to all peers.

0 files changed, 0 insertions, 0 deletions