Add channel reserve as a constraint during order matching/expression

auctioneer/client.go

@@ -507,6 +507,7 @@ func (c *Client) SubmitOrder(ctx context.Context, o order.Order,
 			IsSidecarChannel:    castOrder.SidecarTicket != nil,
 			UnannouncedChannel:  castOrder.UnannouncedChannel,
 			ZeroConfChannel:     castOrder.ZeroConfChannel,
+			MinReserveChannel:   castOrder.MinReserveChannel,
 		}
 		rpcRequest.Details = &auctioneerrpc.ServerSubmitOrderRequest_Bid{
 			Bid: serverBid,

auctioneerrpc/auctioneer.proto

@@ -1083,6 +1083,11 @@ message ServerBid {
     Signals if this bid is interested in a zero conf channel or not.
     */
     bool zero_conf_channel = 9;
+
+    /*
+    Signals if this bid is interested in a minimal reserve channel.
+    */
+    bool min_reserve_channel = 10;
 }
 
 message ServerAsk {

channel_acceptor.go

@@ -212,6 +212,18 @@ func (s *ChannelAcceptor) acceptChannel(_ context.Context,
 		}, nil
 	}
 
+	// If a minimal reserve channel is expected, ensure that the channel
+	// reserve is equal to the dust limit (minimum according to BOLT#2).
+	if expectedChanBid.MinReserveChannel {
+		if req.ChannelReserve != req.DustLimit {
+			return &lndclient.AcceptorResponse{
+				Accept: false,
+				Error: "channel reserve not set to dust limit " +
+					"even though minimal reserve channel expected",
+			}, nil
+		}
+	}
+
 	return &lndclient.AcceptorResponse{
 		Accept: true,
 	}, nil

clientdb/order.go

@@ -58,6 +58,10 @@ const (
 	// orderIsPublicType is the tlv type we use to store a flag value when
 	// it is ok to share details of this order in public markets.
 	orderIsPublicType tlv.Type = 11
+
+	// bidMinReserveChannelType is the tlv type we use to store a flag
+	// value when a bid accepts minimal reserve channels.
+	bidMinReserveChannelType tlv.Type = 12
 )
 
 var (
@@ -704,6 +708,7 @@ func deserializeOrderTlvData(r io.Reader, o order.Order) error {
 		askConfirmationConstraints uint8
 		auctionType                uint8
 		isPublic                   uint8
+		bidMinReserveChannel       uint8
 	)
 
 	// We'll add records for all possible additional order data fields here
@@ -733,6 +738,7 @@ func deserializeOrderTlvData(r io.Reader, o order.Order) error {
 		),
 		tlv.MakePrimitiveRecord(orderAuctionType, &auctionType),
 		tlv.MakePrimitiveRecord(orderIsPublicType, &isPublic),
+		tlv.MakePrimitiveRecord(bidMinReserveChannelType, &bidMinReserveChannel),
 	)
 	if err != nil {
 		return err
@@ -788,6 +794,11 @@ func deserializeOrderTlvData(r io.Reader, o order.Order) error {
 		if ok && t == nil && bidZeroConf == 1 {
 			castOrder.ZeroConfChannel = true
 		}
+
+		t, ok = parsedTypes[bidMinReserveChannelType]
+		if ok && t == nil && bidMinReserveChannel == 1 {
+			castOrder.MinReserveChannel = true
+		}
 	}
 
 	if t, ok := parsedTypes[orderChannelType]; ok && t == nil {
@@ -831,6 +842,7 @@ func serializeOrderTlvData(w io.Writer, o order.Order) error {
 		bidUnannouncedChannel      uint8
 		askConfirmationConstraints uint8
 		bidZeroConfChannel         uint8
+		bidMinReserveChannel       uint8
 	)
 
 	switch castOrder := o.(type) {
@@ -910,6 +922,10 @@ func serializeOrderTlvData(w io.Writer, o order.Order) error {
 		bidZeroConfType, &bidZeroConfChannel,
 	))
 
+	tlvRecords = append(tlvRecords, tlv.MakePrimitiveRecord(
+		bidMinReserveChannelType, &bidMinReserveChannel,
+	))
+
 	tlvRecords = append(tlvRecords, tlv.MakePrimitiveRecord(
 		askChannelConfirmationConstraintsType,
 		&askConfirmationConstraints,

cmd/pool/order.go

@@ -134,6 +134,11 @@ var baseBidFlags = []cli.Flag{
 			"the channels resulting from matching this order " +
 			"will be announced to the network",
 	},
+	cli.BoolFlag{
+		Name: "min_reserve_channel",
+		Usage: "flag used to signal that this bid is interested only " +
+			"in channels which have minimal reserves",
+	},
 	cli.BoolFlag{
 		Name: "zero_conf_channel",
 		Usage: "flag used to signal that this bid is only interested " +
@@ -685,6 +690,7 @@ func parseBaseBid(ctx *cli.Context) (*poolrpc.Bid, *sidecar.Ticket, error) {
 		MinNodeTier:        nodeTier,
 		UnannouncedChannel: ctx.Bool("unannounced_channel"),
 		ZeroConfChannel:    ctx.Bool("zero_conf_channel"),
+		MinReserveChannel:  ctx.Bool("min_reserve_channel"),
 	}
 
 	// Let's find out if this is an order for a sidecar channel because if

order/interfaces.go

@@ -723,6 +723,10 @@ type Bid struct {
 	// ZeroConfChannel signals if the resulting channels need to be zero
 	// conf or not.
 	ZeroConfChannel bool
+
+	// MinReserveChannel signals if the resulting channels may have minimal
+	// reserves or not.
+	MinReserveChannel bool
 }
 
 // Type returns the order type.