We're going to move over to "unsaved channels" instead of using a
separate "uncommitted_channel" struct. This means a peer might have a
channel that's not saved to the database yet in its channel list
We need to make sure that there's at least one input that's represented
in every single RBF-attempt for this channel, to prevent "parallel"
subsequent RBFs from succeeding/opening (the multi-channel backdoor?!)
When the funding tx reaches depth, update the channel's data to the
"correct" funding transaction info from inflights (if necessary).
This will be necessary if:
- the transaction has been successfully RBF'd and
- the lesser fee transaction is the one successfully mined, OR
- the channel is in the process of being RBF'd
Nit: The underscore in "openchannel_hook" is wrong, bcause the name of
the hook is just "openchannel". The "_hook" implied this to be part of
the name.
Changelog-None
We weren't sending a channel_open notification for dual-funded channels.
This is only sent for the 'accepter' side. We send it as soon as both
funding_tx sigs have been exchanged, even though it's possible the
funding transaction might be published without this having been the case.
Since we fail the channel if this happens, only notifying for good/valid
channels reaching the broadcast state is the right way to handle this.
Let plugins know when a channel open has failed.
We need to notify accepters now too, so we remove the check on who's
funding the channel before sending the 'failed' message from
dualopend->master.
We already know what the channel id is, we should go ahead and pass it
on to any listening plugins -- this makes clean up easier/possible
if a open fails early on and we've got reserved utxos.
When we're the opener, we get the upfront shutdown scriptpubkey (if
there is one) from the `close_to` param of `openchannel_init`.
We were passing it through dualopend, but we need to break the update
chain so that our test_option_upfront_shutdown_script test works (same
as on the openingd flow.)
Prior to this, all reconnect logic lived in channeld. If you
disconnected before we finished building a funding transaction, that was
no big deal. Now, however, we're waiting for the funding to lock in in
dualopend, instead of handing straight to channeld to wait.
So we need a way to restart dualopend.
We delegate the decision about what to do about 'out of bound' feerates
to the plugin (if one exists), however in the case that the plugin
doesnt exist or doesnt want to figure it out, we default to using the
'best' as their intended feerate, and rejecting if it's out of bounds.
We need to know if they've sent us their sigs message yet. Ideally, we'd
be able to check the 'finalness' of the PSBT, however if the peer
doesn't have any inputs to the channel this doesn't work.
Back in the days before dual-funding, the `channel` struct on subd was
only every one type per daemon (either struct channel or struct
uncommitted_channel)
The RBF requirement on dualopend means that dualopend's channel,
however, can now be two different things -- either channel or
uncommitted_channel.
To track the difference/disambiguate, we now track the channel type on a
flag on the subd. It gets updated when we swap out the channel.
This will make it possible to do RBF, since we can re-start the opening
process in dualopend while waiting for lock-in.
Note the new channel states are being used, DUALOPEND_INIT and
DUALOPEND_AWAITING_LOCKIN, to differentiate from openingd/channeld opens
