remove session shutdown goroutine, just send a message instead

src/yggdrasil/conn.go

@@ -304,6 +304,8 @@ func (c *Conn) Close() (err error) {
 			// Close the session, if it hasn't been closed already
 			if e := c.session.cancel.Cancel(errors.New("connection closed")); e != nil {
 				err = ConnError{errors.New("close failed, session already closed"), false, false, true, 0}
+			} else {
+				c.session.doRemove()
 			}
 		}
 	})

src/yggdrasil/session.go

@@ -255,13 +255,6 @@ func (ss *sessions) createSession(theirPermKey *crypto.BoxPubKey) *sessionInfo {
 	sinfo.theirSubnet = *address.SubnetForNodeID(crypto.GetNodeID(&sinfo.theirPermPub))
 	ss.sinfos[sinfo.myHandle] = &sinfo
 	ss.byTheirPerm[sinfo.theirPermPub] = &sinfo.myHandle
-	go func() {
-		// Run cleanup when the session is canceled
-		<-sinfo.cancel.Finished()
-		sinfo.sessions.router.doAdmin(func() {
-			sinfo.sessions.removeSession(&sinfo)
-		})
-	}()
 	return &sinfo
 }
 
@@ -293,6 +286,12 @@ func (ss *sessions) cleanup() {
 	ss.lastCleanup = time.Now()
 }
 
+func (sinfo *sessionInfo) doRemove() {
+	sinfo.sessions.router.RecvFrom(nil, func() {
+		sinfo.sessions.removeSession(sinfo)
+	})
+}
+
 // Closes a session, removing it from sessions maps.
 func (ss *sessions) removeSession(sinfo *sessionInfo) {
 	if s := sinfo.sessions.sinfos[sinfo.myHandle]; s == sinfo {