Prior to this patch update, we expected a client to call
`openchannel_signed` before checking for peer's tx-sigs messages on the
wire.
When moving to a 'multifundchannel' approach, we'll need to be able to
collect sigs from our peers before sending our tx_sigs message. There's
no strict ordering on when tx-sigs messages are sent/received, so this
is fine.
To do this, we go ahead and start up channeld as soon as
commitment_sigs are secured, so that we process incoming tx-sigs from
our peers as soon as we get them.
We need the PSBT to create the finalized tx from once the peer's
tx_signatures are received. Since we're passing the PSBT, we no longer
need the secondary message to be passed, as it was derived from the
PSBT.
Also removes now unused witness serialization code
v2 of channel establishment, in the accpeter case, now sends 2 messages
to our peer after saving the information to disk (our commitment
signatures and our funding transaction signatures)
v2 channel open uses a different method to derive the channel_id, so now
we save it to the database so that we dont have to remember how to
derive it for each.
includes a migration for existing channels
This means some files get renamed, and I took the opportunity to clarify
our naming (the *d* is important!)
1. channeld/channel_wire.csv -> channeld/channeld_wire.csv
2. channeld/gen_channel_wire.h -> channeld/channeld_wiregen.h
3. enum channel_wire_type -> enum channeld_wire
4. WIRE_CHANNEL_FUNDING_DEPTH -> WIRE_CHANNELD_FUNDING_DEPTH.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
niftynei
Rusty Russell