[bug]: BatchOpenChannel RPC will always use 6 confirmation target for the fee estimation

[ziggie1984]

Currently you cannot control the feerate when using the BatchOpenChannel API, it will default to a conftarget of 6.

Culprit lies here:

We excluded the fee estimation logic when using the psbt flow but the batchopen flow uses the psbt funding flow so we cannot do so.

lnd/rpcserver.go

Lines 2176 to 2195 in 71ba355

	if in.FundingShim == nil || in.FundingShim.GetPsbtShim() == nil {
	// Keep the old behavior prior to 0.18.0 - when the user
	// doesn't set fee rate or conf target, the default conf target
	// of 6 is used.
	targetConf := maybeUseDefaultConf(
	in.SatPerByte, in.SatPerVbyte, uint32(in.TargetConf),
	)
	// Calculate an appropriate fee rate for this transaction.
	feeRate, err = lnrpc.CalculateFeeRate(
	uint64(in.SatPerByte), in.SatPerVbyte,
	targetConf, r.server.cc.FeeEstimator,
	)
	if err != nil {
	return nil, err
	}
	rpcsLog.Debugf("[openchannel]: using fee of %v sat/kw for "+
	"funding tx", int64(feeRate))
	}

Moreover using pointer here, shadowed the bug unfortunately which caused us to use 6 rather then failing with an error.

https://github.com/lightningnetwork/lnd/blob/master/server.go#L4521-L4566

Going to provide a fix asap.

[bitromortac]

Does it ignore the target field? Setting SatPerVbyte seems to work for me.

[ziggie1984]

it ignores the whole fee calc., can you verify that your selected feerate and the fee estimation of 6 blocks did not by incident just were the same ?

Its a bug introduced in 18, so it would work just fine with 17

[bitromortac]

Right that could be the case, will double check.