watchtower/wtserver: add DeleteSession handler

watchtower/wtserver/delete_session.go

@@ -0,0 +1,57 @@
+package wtserver
+
+import (
+	"github.com/lightningnetwork/lnd/watchtower/wtdb"
+	"github.com/lightningnetwork/lnd/watchtower/wtwire"
+)
+
+// handleDeleteSession processes a DeleteSession request for a client with given
+// SessionID. The id is assumed to have been previously authenticated by the
+// brontide connection.
+func (s *Server) handleDeleteSession(peer Peer, id *wtdb.SessionID) error {
+	var failCode wtwire.DeleteSessionCode
+
+	// Delete all session data associated with id.
+	err := s.cfg.DB.DeleteSession(*id)
+	switch {
+	case err == nil:
+		failCode = wtwire.CodeOK
+
+		log.Debugf("Session %s deleted", id)
+
+	case err == wtdb.ErrSessionNotFound:
+		failCode = wtwire.DeleteSessionCodeNotFound
+
+	default:
+		failCode = wtwire.CodeTemporaryFailure
+	}
+
+	return s.replyDeleteSession(peer, id, failCode)
+}
+
+// replyDeleteSession sends a DeleteSessionReply back to the peer containing the
+// error code resulting from processes a DeleteSession request.
+func (s *Server) replyDeleteSession(peer Peer, id *wtdb.SessionID,
+	code wtwire.DeleteSessionCode) error {
+
+	msg := &wtwire.DeleteSessionReply{
+		Code: code,
+	}
+
+	err := s.sendMessage(peer, msg)
+	if err != nil {
+		log.Errorf("Unable to send DeleteSessionReply to %s", id)
+	}
+
+	// Return the write error if the request succeeded.
+	if code == wtwire.CodeOK {
+		return err
+	}
+
+	// Otherwise the request failed, return a connection failure to
+	// disconnect the client.
+	return &connFailure{
+		ID:   *id,
+		Code: uint16(code),
+	}
+}

watchtower/wtserver/server.go

@@ -259,6 +259,13 @@ func (s *Server) handleClient(peer Peer) {
 				"from %s: %v", id, err)
 		}
 
+	case *wtwire.DeleteSession:
+		err = s.handleDeleteSession(peer, &id)
+		if err != nil {
+			log.Errorf("Unable to handle DeleteSession "+
+				"from %s: %v", id, err)
+		}
+
 	case *wtwire.StateUpdate:
 		err = s.handleStateUpdates(peer, &id, msg)
 		if err != nil {