Allow relays to set peering policy
As mentioned in the discussion at tor-relays@ (, ), it would be nice to have some kind of peering policy for relays so that relay operators could restrict connections with suspicious/malicious relays themselves.
Having PeeringPolicy similar to ExitPolicy (accept, reject) is what comes to mind first. Though it may not be the best solution.
Also, as a side effect it can allow to have smaller state table/less file descriptors for average relay that can help with scaling of the network in the future.