--- /sys/src/cmd/aux/listen.c	Mon Nov  5 07:29:45 2018
+++ ../patched/gridlisten.c	Wed Nov 27 14:29:01 2019
@@ -31,6 +31,7 @@
 void	scandir(char*, char*, char*, char*);
 void	becomenone(void);
 void	listendir(char*, char*, char*, int);
+void	doregister(char*);
 
 char	listenlog[] = "listen";
 
@@ -215,6 +216,8 @@
 						else
 							exits("ctl");
 					}
+					fprint(2, "registering %s\n", a->a);
+					doregister(a->a);
 					dolisten(proto, dir, ctl, srvdir, ds, &childs);
 					close(ctl);
 				}
@@ -346,6 +349,28 @@
 	close(fd);
 	if(newns("none", namespace) < 0)
 		error("can't build namespace");
+}
+
+void
+doregister(char *announce)
+{
+	int regfd;
+	char *loc;
+
+	switch(rfork(RFPROC|RFFDG)) {
+	case -1:
+		error("fork");
+	case 0:
+		if((loc=getenv("myip")) == 0)
+			loc=getenv("sysname");
+		regfd=open("/mnt/registry/new", OWRITE);
+		fprint(regfd, "tcp!%s!%s sys %s user %s", loc, announce+6, getenv("sysname"), getenv("user"));
+		for(;;)
+			sleep(1000);
+		break;
+	default:
+		return;
+	}
 }
 
 void