From f4feb1e6975d4da2632cf6918e4fc33ca7d77442 Mon Sep 17 00:00:00 2001
From: "Johan T. Halseth" <johanth@gmail.com>
Date: Sun, 17 Dec 2017 14:31:38 +0100
Subject: [PATCH] config: add forwarding policy rules to config

This commit moves the forwarding policy rules for Bitcoin
and Litecoin, previously defined in the chainregistry, to
config.go, making them possible to define by the user.
We validate that the TimeLockDelta set is at least 4, the
other rules we let the user specify arbitrarily, even 0.
---
 config.go | 45 +++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 41 insertions(+), 4 deletions(-)

diff --git a/config.go b/config.go
index d0751d1c..98517752 100644
--- a/config.go
+++ b/config.go
@@ -41,6 +41,20 @@ const (
 	defaultNumChanConfs       = 3
 	defaultNoEncryptWallet    = false
 	defaultTrickleDelay       = 30 * 1000
+
+	// minTimeLockDelta is the minimum timelock we require for incoming
+	// HTLCs on our channels.
+	minTimeLockDelta = 4
+
+	defaultBitcoinMinHTLCMSat   = 1000
+	defaultBitcoinBaseFeeMSat   = 1000
+	defaultBitcoinFeeRate       = 1
+	defaultBitcoinTimeLockDelta = 144
+
+	defaultLitecoinMinHTLCMSat   = 1000
+	defaultLitecoinBaseFeeMSat   = 1000
+	defaultLitecoinFeeRate       = 1
+	defaultLitecoinTimeLockDelta = 576
 )
 
 var (
@@ -74,6 +88,11 @@ type chainConfig struct {
 	TestNet3 bool `long:"testnet" description:"Use the test network"`
 	SimNet   bool `long:"simnet" description:"Use the simulation test network"`
 	RegTest  bool `long:"regtest" description:"Use the regression test network"`
+
+	MinHTLC       lnwire.MilliSatoshi `long:"minhtlc" description:"The smallest HTLC we are willing to forward on our channels, in millisatoshi"`
+	BaseFee       lnwire.MilliSatoshi `long:"basefee" description:"The base fee in millisatoshi we will charge for forwarding payments on our channels"`
+	FeeRate       lnwire.MilliSatoshi `long:"feerate" description:"The fee rate used when forwarding payments on our channels. The total fee charged is basefee + (amount * feerate / 1000000), where amount is the forwarded amount."`
+	TimeLockDelta uint32              `long:"timelockdelta" description:"The CLTV delta we will subtract from a forwarded HTLC's timelock value"`
 }
 
 type neutrinoConfig struct {
@@ -165,12 +184,20 @@ func loadConfig() (*config, error) {
 		DefaultNumChanConfs: defaultNumChanConfs,
 		NoEncryptWallet:     defaultNoEncryptWallet,
 		Bitcoin: &chainConfig{
-			RPCHost: defaultRPCHost,
-			RPCCert: defaultBtcdRPCCertFile,
+			RPCHost:       defaultRPCHost,
+			RPCCert:       defaultBtcdRPCCertFile,
+			MinHTLC:       defaultBitcoinMinHTLCMSat,
+			BaseFee:       defaultBitcoinBaseFeeMSat,
+			FeeRate:       defaultBitcoinFeeRate,
+			TimeLockDelta: defaultBitcoinTimeLockDelta,
 		},
 		Litecoin: &chainConfig{
-			RPCHost: defaultRPCHost,
-			RPCCert: defaultLtcdRPCCertFile,
+			RPCHost:       defaultRPCHost,
+			RPCCert:       defaultLtcdRPCCertFile,
+			MinHTLC:       defaultLitecoinMinHTLCMSat,
+			BaseFee:       defaultLitecoinBaseFeeMSat,
+			FeeRate:       defaultLitecoinFeeRate,
+			TimeLockDelta: defaultLitecoinTimeLockDelta,
 		},
 		Autopilot: &autoPilotConfig{
 			MaxChannels: 5,
@@ -256,6 +283,11 @@ func loadConfig() (*config, error) {
 			return nil, fmt.Errorf(str, funcName)
 		}
 
+		if cfg.Litecoin.TimeLockDelta < minTimeLockDelta {
+			return nil, fmt.Errorf("timelockdelta must be at least %v",
+				minTimeLockDelta)
+		}
+
 		// The litecoin chain is the current active chain. However
 		// throughout the codebase we required chiancfg.Params. So as a
 		// temporary hack, we'll mutate the default net params for
@@ -305,6 +337,11 @@ func loadConfig() (*config, error) {
 			return nil, err
 		}
 
+		if cfg.Bitcoin.TimeLockDelta < minTimeLockDelta {
+			return nil, fmt.Errorf("timelockdelta must be at least %v",
+				minTimeLockDelta)
+		}
+
 		if !cfg.NeutrinoMode.Active {
 			// If needed, we'll attempt to automatically configure
 			// the RPC control plan for the target btcd node.