Merge pull request #1213 from halseth/fail-channel

[htlcswitch] Optionally force close channel on link failure

contractcourt/channel_arbitrator.go

@@ -85,8 +85,10 @@ type ChannelArbitratorConfig struct {
 
 	// ForceCloseChan should force close the contract that this attendant
 	// is watching over. We'll use this when we decide that we need to go
-	// to chain. The returned summary contains all items needed to
-	// eventually resolve all outputs on chain.
+	// to chain. It should in addition tell the switch to remove the
+	// corresponding link, such that we won't accept any new updates. The
+	// returned summary contains all items needed to eventually resolve all
+	// outputs on chain.
 	ForceCloseChan func() (*lnwallet.LocalForceCloseSummary, error)
 
 	// MarkCommitmentBroadcasted should mark the channel as the commitment
@@ -434,9 +436,10 @@ func (c *ChannelArbitrator) stateStep(triggerHeight uint32,
 		// Now that we have all the actions decided for the set of
 		// HTLC's, we'll broadcast the commitment transaction, and
 		// signal the link to exit.
-		//
-		// TODO(roasbeef): need to report to switch that channel is
-		// inactive, should close link
+
+		// We'll tell the switch that it should remove the link for
+		// this channel, in addition to fetching the force close
+		// summary needed to close this channel on chain.
 		closeSummary, err := c.cfg.ForceCloseChan()
 		if err != nil {
 			log.Errorf("ChannelArbitrator(%v): unable to "+

htlcswitch/hodl/config.go

@@ -21,6 +21,8 @@ type Config struct {
 	FailOutgoing bool `long:"fail-outgoing" description:"Instructs the node to drop outgoing FAILs before applying them to the channel state"`
 
 	Commit bool `long:"commit" description:"Instructs the node to add HTLCs to its local commitment state and to open circuits for any ADDs, but abort before committing the changes"`
+
+	BogusSettle bool `long:"bogus-settle" description:"Instructs the node to settle back any incoming HTLC with a bogus preimage"`
 }
 
 // Mask extracts the flags specified in the configuration, composing a Mask from
@@ -52,6 +54,9 @@ func (c *Config) Mask() Mask {
 	if c.Commit {
 		flags = append(flags, Commit)
 	}
+	if c.BogusSettle {
+		flags = append(flags, BogusSettle)
+	}
 
 	// NOTE: The value returned here will only honor the configuration if
 	// the debug build flag is present. In production, this method always

htlcswitch/hodl/flags.go

@@ -51,6 +51,10 @@ const (
 	// Commit drops all HTLC after any outgoing circuits have been
 	// opened, but before the in-memory commitment state is persisted.
 	Commit
+
+	// BogusSettle attempts to settle back any incoming HTLC for which we
+	// are the exit node with a bogus preimage.
+	BogusSettle
 )
 
 // String returns a human-readable identifier for a given Flag.
@@ -72,6 +76,8 @@ func (f Flag) String() string {
 		return "FailOutgoing"
 	case Commit:
 		return "Commit"
+	case BogusSettle:
+		return "BogusSettle"
 	default:
 		return "UnknownHodlFlag"
 	}
@@ -98,6 +104,8 @@ func (f Flag) Warning() string {
 		msg = "will not update channel state with downstream FAIL"
 	case Commit:
 		msg = "will not commit pending channel updates"
+	case BogusSettle:
+		msg = "will settle HTLC with bogus preimage"
 	default:
 		msg = "incorrect hodl flag usage"
 	}

htlcswitch/hodl/mask_test.go

@@ -67,6 +67,7 @@ var hodlMaskTests = []struct {
 			hodl.SettleOutgoing,
 			hodl.FailOutgoing,
 			hodl.Commit,
+			hodl.BogusSettle,
 		),
 		flags: map[hodl.Flag]struct{}{
 			hodl.ExitSettle:     {},
@@ -77,6 +78,7 @@ var hodlMaskTests = []struct {
 			hodl.SettleOutgoing: {},
 			hodl.FailOutgoing:   {},
 			hodl.Commit:         {},
+			hodl.BogusSettle:    {},
 		},
 	},
 }

htlcswitch/interfaces.go

@@ -130,10 +130,6 @@ type Peer interface {
 
 	// PubKey returns the serialize public key of the source peer.
 	PubKey() [33]byte
-
-	// Disconnect disconnects with peer if we have error which we can't
-	// properly handle.
-	Disconnect(reason error)
 }
 
 // ForwardingLog is an interface that represents a time series database which