loopd: add initiator to swap requests

loopd/swapclient_server.go

@@ -99,7 +99,8 @@ func (s *swapClientServer) LoopOut(ctx context.Context,
 		SwapPublicationDeadline: time.Unix(
 			int64(in.SwapPublicationDeadline), 0,
 		),
-		Label: in.Label,
+		Label:     in.Label,
+		Initiator: in.Initiator,
 	}
 
 	switch {
@@ -496,6 +497,7 @@ func (s *swapClientServer) LoopIn(ctx context.Context,
 		HtlcConfTarget: htlcConfTarget,
 		ExternalHtlc:   in.ExternalHtlc,
 		Label:          in.Label,
+		Initiator:      in.Initiator,
 	}
 	if in.LastHop != nil {
 		lastHop, err := route.NewVertexFromBytes(in.LastHop)

version.go

@@ -8,6 +8,7 @@ package loop
 import (
 	"bytes"
 	"fmt"
+	"math"
 	"strings"
 )
 
@@ -64,6 +65,13 @@ func UserAgent(initiator string) string {
 		cleanInitiator = fmt.Sprintf(",initiator=%s", cleanInitiator)
 	}
 
+	// The whole user agent string is limited to 255 characters server side
+	// and also consists of the agent name, version and commit. So we only
+	// want to take up at most 150 characters for the initiator. Anything
+	// more will just be dropped.
+	strLen := len(cleanInitiator)
+	cleanInitiator = cleanInitiator[:int(math.Min(float64(strLen), 150))]
+
 	// Assemble full string, including the commit hash of current build.
 	return fmt.Sprintf(
 		"%s/v%s/commit=%s%s", AgentName, semanticVersion(), Commit,