This reverts commit 3037feb1bf.
On second thought, this was an overcomplication of what should be the
lowest-level primitive. Let's build bi-directional links at the pairing
level with eg magic wormhole.
Both the local and remote git repositories get remotes added
pointing at one-another.
Makes pairing twice as easy!
Security: The new LINK command in the protocol can be sent repeatedly,
but only by a peer who has authenticated with us. So, it's entirely safe to
add a link back to that peer, or to some other peer it knows about.
Anything we receive over such a link, the peer could send us over the
current connection.
There is some risk of being flooded with LINKs, and adding too many
remotes. To guard against that, there's a hard cap on the number of remotes
that can be set up this way. This will only be a problem if setting up
large p2p networks that have exceptional interconnectedness.
A new, dedicated authtoken is created when sending LINK.
This also allows, in theory, using a p2p network like tor, to learn about
links on other networks, like telehash.
This commit was sponsored by Bruno BEAUFILS on Patreon.
Revert ServerAliveInterval change in 6.20161111, which caused problems
with too many old versions of ssh and unusual ssh configurations.
It should have not been needed anyway since ssh is supposted to
have TCPKeepAlive enabled by default.
1 microsecond delay is ugly.. but, maintaining an queue of a list of timestamps
and taking a new one from the queue each time around, or maintaining a timestamp
counter, would probably be slower.
