Simplify shutdown process.

On shutdown, there's no need to use kill(2) to kill the child
processes. Just closing the IPC sockets will make the children receive
an EOF, break out from the event loop and then exit.

Tha advantages of this "pipe teardown" are:
* simpler code;
* no need to pledge "proc" in the parent process;
* removal of a (hard to trigger) PID reuse race condition.

ok benno@ claudio@

1 files changed, 9 insertions, 6 deletions

diff --git a/usr.sbin/ripd/rde.c b/usr.sbin/ripd/rde.c
index 70940d62a26..61085344060 100644
--- a/usr.sbin/ripd/rde.c
+++ b/usr.sbin/ripd/rde.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rde.c,v 1.20 2016/09/02 14:07:52 benno Exp $ */
+/*	$OpenBSD: rde.c,v 1.21 2016/09/03 10:28:08 renato Exp $ */
 
 /*
  * Copyright (c) 2006 Michele Marchetto <mydecay@openbeer.it>
@@ -45,7 +45,7 @@ struct imsgev		*iev_ripe;
 struct imsgev		*iev_main;
 
 void	rde_sig_handler(int, short, void *);
-void	rde_shutdown(void);
+__dead void rde_shutdown(void);
 void	rde_dispatch_imsg(int, short, void *);
 void	rde_dispatch_parent(int, short, void *);
 int	rde_imsg_compose_ripe(int, u_int32_t, pid_t, void *, u_int16_t);
@@ -159,14 +159,17 @@ rde(struct ripd_conf *xconf, int pipe_parent2rde[2], int pipe_ripe2rde[2],
 	return (0);
 }
 
-void
+__dead void
 rde_shutdown(void)
 {
-	rt_clear();
-
+	/* close pipes */
 	msgbuf_clear(&iev_ripe->ibuf.w);
-	free(iev_ripe);
+	close(iev_ripe->ibuf.fd);
 	msgbuf_clear(&iev_main->ibuf.w);
+	close(iev_main->ibuf.fd);
+
+	rt_clear();
+	free(iev_ripe);
 	free(iev_main);
 	free(rdeconf);