The first reconnection attempt waits for 1min, the second the 2min,
and so on up to 10min. There's a 1min jitter so that multiple failed
connections don't try to reconnect at the exact same time.
Closes: https://todo.sr.ht/~emersion/soju/161
Once the downstream connection has logged in with their bouncer
credentials, allow them to issue more SASL auths which will be
redirected to the upstream network. This allows downstream clients
to provide UIs to login to transparently login to upstream networks.
Implements the following recommendation from the spec:
> If the client completes registration (with CAP END, NICK, USER and any other
> necessary messages) while the SASL authentication is still in progress, the
> server SHOULD abort it and send a 906 numeric, then register the client
> without authentication.
The MOTD indicates the end of the registration's message burst, and
the server can send arbitrary messages before it.
Update the supported capabilities, the nick and the realname before
MOTD to make it so client logic that runs on MOTD can work with
up-to-date info.
This function wraps a parent context, and returns a new context
cancelled when the connection is closed. This will make it so
operations started from downstreamConn.handleMessage will be
cancelled when the connection is closed.
As a bonus, the timeout now applies to the whole TLS dial
operation. Before the timeout only applied to the net dial
operation, making it possible for a bad server to stall the request
by making the TLS handshake extremely slow.
When on an unbound bouncer network downstream, we should return no
targets (there are none, because there are no upstreams at all).
When on a multi-upstream downstream, we should return no targets as we
don't support multi-upstream CHATHISTORY TARGETS.
Before this patch, we returned a misleading error message:
:example.com 403 :Missing network suffix in name
The bouncer process may be dealing with many opened FDs. The default
on Linux is 1024. To support bouncers with a lot of users, bump
RLIMIT_NOFILE to the max as advised in [1].
[1]: http://0pointer.net/blog/file-descriptor-limits.html
