For the moment, there's no way to remove an in-progress HTLC before
it's timed out. The other side can remove it with a routefail, but
you can't push for it to be removed.
We may add that later, but by definition it's only a polited request, and
normally we should rely on timeouts.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We don't have to accept an HTLC they offer; we might not be able to
route it, or it might offer insufficient payment.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This gets truncated for on-chain transactions (thus, rounding may
contribute to fees).
This also means we currently have an upper bound of 0.04 BTC per HTLC;
this can be increased later if required.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We can save an opcode in both HTLC send and receive scripts by using
OP_2DROP instead of OP_DROP twice.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Our current proto_to_locktime actually handles relative locktimes,
and HTLCs use absolute. Fix that.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
For open transactions, locktime is a delay we require on the other
side's to-self commit transaction outputs to ensure we can cut them
off if necessary.
For HTLCs, it's an absolute expiry time.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Proposing an HTLC follows the same sequence as proposing a normal
update. There's also requests to complete and remove HTLCs.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This shows where funds are going at any time (fees vs to each side).
funding.c is mainly rewritten, and should be clearer now.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This effectively removes the escape-transaction dual anchor code in
favor of single-funder anchor.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Both sides elect a commitment fee, and the lowest is chosen. That means
you can't game the other side (but if you offer too low, then can error
out of course).
Fees are split 50-50 if possible: originally the whole fee has to be
paid by the (single) funder. Neither side can withdraw funds which
would make them unable to pay fees.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Most complex change was gather_updates(), which handles all the "what
is the current state of the channel" logic for our dumb test utils.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>