multi: replace DefaultDustLimit with script-specific DustLimitForSize

This commit updates call-sites to use the proper dust limits for
various script types. This also updates the default dust limit used
in the funding flow to be 354 satoshis instead of 573 satoshis.

funding/manager.go

@@ -3114,19 +3114,10 @@ func (f *Manager) handleInitFundingMsg(msg *InitFundingMsg) {
 		maxCSV = f.cfg.MaxLocalCSVDelay
 	}
 
-	// We'll determine our dust limit depending on which chain is active.
-	var ourDustLimit btcutil.Amount
-	switch f.cfg.RegisteredChains.PrimaryChain() {
-	case chainreg.BitcoinChain:
-		ourDustLimit = lnwallet.DefaultDustLimit()
-	case chainreg.LitecoinChain:
-		ourDustLimit = chainreg.DefaultLitecoinDustLimit
-	}
 	log.Infof("Initiating fundingRequest(local_amt=%v "+
 		"(subtract_fees=%v), push_amt=%v, chain_hash=%v, peer=%x, "+
-		"dust_limit=%v, min_confs=%v)", localAmt, msg.SubtractFees,
-		msg.PushAmt, msg.ChainHash, peerKey.SerializeCompressed(),
-		ourDustLimit, msg.MinConfs)
+		"min_confs=%v)", localAmt, msg.SubtractFees, msg.PushAmt,
+		msg.ChainHash, peerKey.SerializeCompressed(), msg.MinConfs)
 
 	// We set the channel flags to indicate whether we want this channel to
 	// be announced to the network.
@@ -3300,6 +3291,12 @@ func (f *Manager) handleInitFundingMsg(msg *InitFundingMsg) {
 	// request to the remote peer, kicking off the funding workflow.
 	ourContribution := reservation.OurContribution()
 
+	// Fetch our dust limit which is part of the default channel
+	// constraints, and log it.
+	ourDustLimit := ourContribution.DustLimit
+
+	log.Infof("Dust limit for pendingID(%x): %v", chanID, ourDustLimit)
+
 	// Finally, we'll use the current value of the channels and our default
 	// policy to determine of required commitment constraints for the
 	// remote party.
@@ -3313,7 +3310,7 @@ func (f *Manager) handleInitFundingMsg(msg *InitFundingMsg) {
 		PendingChannelID:      chanID,
 		FundingAmount:         capacity,
 		PushAmount:            msg.PushAmt,
-		DustLimit:             ourContribution.DustLimit,
+		DustLimit:             ourDustLimit,
 		MaxValueInFlight:      maxValue,
 		ChannelReserve:        chanReserve,
 		HtlcMinimum:           minHtlcIn,

funding/manager_test.go

@@ -276,7 +276,7 @@ func createTestWallet(cdb *channeldb.DB, netParams *chaincfg.Params,
 		ChainIO:            bio,
 		FeeEstimator:       estimator,
 		NetParams:          *netParams,
-		DefaultConstraints: chainreg.DefaultBtcChannelConstraints,
+		DefaultConstraints: chainreg.GenDefaultBtcConstraints(),
 	})
 	if err != nil {
 		return nil, err