Add cln channel acceptor

cln_plugin/channel_acceptor.go

@@ -0,0 +1,37 @@
+package cln_plugin
+
+import (
+	"encoding/json"
+	"fmt"
+
+	sj "go.starlark.net/lib/json"
+	"go.starlark.net/starlark"
+)
+
+func channelAcceptor(acceptScript string, method string, openChannel json.RawMessage) (json.RawMessage, error) {
+	reject, _ := json.Marshal(struct {
+		Result string `json:"result"`
+	}{Result: "reject"})
+
+	sd := starlark.StringDict{
+		"method":      starlark.String(method),
+		"openchannel": starlark.String(openChannel),
+	}
+	for _, k := range sj.Module.Members.Keys() {
+		sd[k] = sj.Module.Members[k]
+	}
+	value, err := starlark.Eval(
+		&starlark.Thread{},
+		"",
+		acceptScript,
+		sd,
+	)
+	if err != nil {
+		return reject, err
+	}
+	s, ok := value.(starlark.String)
+	if !ok {
+		return reject, fmt.Errorf("not a string")
+	}
+	return json.RawMessage(s.GoString()), nil
+}

cln_plugin/cln_plugin.go

@@ -19,6 +19,7 @@ import (
 const (
 	SubscriberTimeoutOption = "lsp-subscribertimeout"
 	ListenAddressOption     = "lsp-listen"
+	channelAcceptScript     = "lsp-channel-accept-script"
 )
 
 var (
@@ -43,11 +44,12 @@ var (
 )
 
 type ClnPlugin struct {
-	done     chan struct{}
-	server   *server
-	in       *os.File
-	out      *bufio.Writer
-	writeMtx sync.Mutex
+	done                chan struct{}
+	server              *server
+	in                  *os.File
+	out                 *bufio.Writer
+	writeMtx            sync.Mutex
+	channelAcceptScript string
 }
 
 func NewClnPlugin(in, out *os.File) *ClnPlugin {
@@ -210,6 +212,20 @@ func (c *ClnPlugin) processRequest(request *Request) {
 		c.handleShutdown(request)
 	case "htlc_accepted":
 		c.handleHtlcAccepted(request)
+	case "openchannel":
+		// handle open channel in a goroutine, because order doesn't  matter.
+		go c.handleOpenChannel(request)
+	case "openchannel2":
+		// handle open channel in a goroutine, because order doesn't  matter.
+		go c.handleOpenChannel(request)
+	case "getchannelacceptscript":
+		c.sendToCln(&Response{
+			JsonRpc: SpecVersion,
+			Id:      request.Id,
+			Result:  c.channelAcceptScript,
+		})
+	case "setchannelacceptscript":
+		c.handleSetChannelAcceptScript(request)
 	default:
 		c.sendError(
 			request.Id,
@@ -239,14 +255,28 @@ func (c *ClnPlugin) handleGetManifest(request *Request) {
 						"if no subscriber is active. golang duration string.",
 					Default: &DefaultSubscriberTimeout,
 				},
+				{
+					Name:        channelAcceptScript,
+					Type:        "string",
+					Description: "starlark script for channel acceptor.",
+				},
 			},
-			RpcMethods: []*RpcMethod{},
-			Dynamic:    true,
-			Hooks: []Hook{
+			RpcMethods: []*RpcMethod{
+				{
+					Name:        "getchannelacceptscript",
+					Description: "Get the startlark channel acceptor script",
+				},
 				{
-					Name: "htlc_accepted",
+					Name:        "setchannelacceptscript",
+					Description: "Set the startlark channel acceptor script",
 				},
 			},
+			Dynamic: true,
+			Hooks: []Hook{
+				{Name: "htlc_accepted"},
+				{Name: "openchannel"},
+				{Name: "openchannel2"},
+			},
 			NonNumericIds: true,
 			Subscriptions: []string{
 				"shutdown",
@@ -270,6 +300,31 @@ func (c *ClnPlugin) handleInit(request *Request) {
 		return
 	}
 
+	// Get the channel acceptor script option.
+	sc, ok := initMsg.Options[channelAcceptScript]
+	if !ok {
+		c.sendError(
+			request.Id,
+			InvalidParams,
+			fmt.Sprintf("Missing option '%s'", channelAcceptScript),
+		)
+		return
+	}
+
+	c.channelAcceptScript, ok = sc.(string)
+	if !ok {
+		c.sendError(
+			request.Id,
+			InvalidParams,
+			fmt.Sprintf(
+				"Invalid value '%v' for option '%s'",
+				sc,
+				channelAcceptScript,
+			),
+		)
+		return
+	}
+
 	// Get the listen address option.
 	l, ok := initMsg.Options[ListenAddressOption]
 	if !ok {
@@ -382,6 +437,79 @@ func (c *ClnPlugin) handleHtlcAccepted(request *Request) {
 	c.server.Send(idToString(request.Id), &htlc)
 }
 
+func (c *ClnPlugin) handleSetChannelAcceptScript(request *Request) {
+	var params []string
+	err := json.Unmarshal(request.Params, &params)
+	if err != nil {
+		c.sendError(
+			request.Id,
+			ParseError,
+			fmt.Sprintf(
+				"Failed to unmarshal setchannelacceptscript params:%s [%s]",
+				err.Error(),
+				request.Params,
+			),
+		)
+		return
+	}
+	if len(params) >= 1 {
+		c.channelAcceptScript = params[0]
+	}
+	c.sendToCln(&Response{
+		JsonRpc: SpecVersion,
+		Id:      request.Id,
+		Result:  c.channelAcceptScript,
+	})
+}
+
+func unmarshalOpenChannel(request *Request) (r json.RawMessage, err error) {
+	switch request.Method {
+	case "openchannel":
+		var openChannel struct {
+			OpenChannel json.RawMessage `json:"openchannel"`
+		}
+		err = json.Unmarshal(request.Params, &openChannel)
+		if err != nil {
+			return
+		}
+		r = openChannel.OpenChannel
+	case "openchannel2":
+		var openChannel struct {
+			OpenChannel json.RawMessage `json:"openchannel2"`
+		}
+		err = json.Unmarshal(request.Params, &openChannel)
+		if err != nil {
+			return
+		}
+		r = openChannel.OpenChannel
+	}
+	return r, nil
+}
+func (c *ClnPlugin) handleOpenChannel(request *Request) {
+	p, err := unmarshalOpenChannel(request)
+	if err != nil {
+		c.sendError(
+			request.Id,
+			ParseError,
+			fmt.Sprintf(
+				"Failed to unmarshal openchannel params:%s [%s]",
+				err.Error(),
+				request.Params,
+			),
+		)
+		return
+	}
+	result, err := channelAcceptor(c.channelAcceptScript, request.Method, p)
+	if err != nil {
+		log.Printf("channelAcceptor error - request: %s error: %v", request, err)
+	}
+	c.sendToCln(&Response{
+		JsonRpc: SpecVersion,
+		Id:      request.Id,
+		Result:  result,
+	})
+}
+
 // Sends an error to cln.
 func (c *ClnPlugin) sendError(id json.RawMessage, code int, message string) {
 	// Log the error to cln first.

go.mod

@@ -21,6 +21,7 @@ require (
 	github.com/lightningnetwork/lnd/tlv v1.1.0
 	github.com/niftynei/glightning v0.8.2
 	github.com/stretchr/testify v1.8.1
+	go.starlark.net v0.0.0-20230612165344-9532f5667272
 	golang.org/x/exp v0.0.0-20230321023759-10a507213a29
 	golang.org/x/sync v0.1.0
 	google.golang.org/grpc v1.50.1