The feerate security margin is a multiplicative factor applied to the
feerate of some transactions in order to guarantee that the
transaction remains publishable and has a sufficient chance of being
confirmed, that we can base some of our decisions on that.
The multiplicative factor is >=1 and was so far a constant 2. This
might have been sensible in the low-fee environment, where the fees
are expected to oscillate, and almost guaranteeing that we will
eventually have rising feerates but in high-fee environments that is
no longer the case, and the 100% margin that the multiplicator 2
brings is excessive. We therefore opt to start out with 100%, then
linearly interpolate up to a given maxfeerate (which does not have to
be a real feerate ever reached, it just indicates the feerate after
which we apply the constant 10% margin.
Fixes#6974Closes#6976
[Fixed up all the other changes required, including spendable calcualtion
comments and unit test and pytest tests --RR]
We have various functions to convert to a string, rename them all so we can
count on fmt_X being the formatter for struct X, and make them all return
`char *`.
Sometimes they existed but were private, sometimes they had a
different name. Most take a pointer, but simple types pass by copy:
short_channel_id, amount_msat and amount_sat.
The following public functions changed:
1. psbt_to_b64 -> fmt_wally_psbt.
2. pubkey_to_hexstr -> fmt_pubkey.
3. short_channel_id_to_str -> fmt_short_channel_id (scid by copy now!)
4. fmt_signature -> fmt_secp256k1_ecdsa_signature
5. fmt_amount_sat/fmt_amount_msat pass copy not pointer, return non-const char *.
6. node_id_to_hexstr -> fmt_node_id
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
And turn "" includes into full-path (which makes it easier to put
config.h first, and finds some cases check-includes.sh missed
previously).
config.h sets _GNU_SOURCE which really needs to be done before any
'#includes': we mainly got away with it with glibc, but other platforms
like Alpine may have stricter requirements.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
For quiescence, we can't have sent any updates at all.
But for upgrades on reconnection, we may have already added
uncommitted HTLCs for retransmission, but they don't count towards
"are we quiesced" since they're not sent yet.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
There are several reports of desynchronization with LND here; a simple
approach is to only have one feerate change in flight at any time.
Even if this turns out to be our fault, it's been a historic area of
confusion, so this restriction seems reasonable.
Changelog-Fixed: Protocol: Don't create more than one feerate change at a time, as this seems to desync with LND.
Fixes: #4152
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Previously we've used the term 'funder' to refer to the peer
paying the fees for a transaction; v2 of openchannel will make
this no longer true. Instead we rename this to 'opener', or the
peer sending the 'open_channel' message, since this will be universally
true in a dual-funding world.
This uses the same state machine as HTLCs, but they're only
ever added, not removed. Since we can only have one in each
state, we use a simple array; mostly NULL.
We could make this more space-efficient by folding everything into the
first 5 states, but that would be more complex than just using the
identical state machine.
One subtlety: we don't send uncommitted fee_states over the wire.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
