Fix broken pipe teardown.

* Add missing close() calls to actually close the pipes, calling just
  msgbuf_clean() is not enough;
* Bring back some NOTREACHED lint comments. style(9) says they can be
  removed but in some cases they are useful to humans too;
* Add __dead to the shutdown functions;
* Some other minor changes to make eigrpd(8) more similar to the other
  routing daemons.

eigrpd.c

@@ -69,6 +69,7 @@ main_sig_handler(int sig, short event, void *arg)
 	case SIGTERM:
 	case SIGINT:
 		eigrpd_shutdown();
+		/* NOTREACHED */
 	case SIGHUP:
 		if (eigrp_reload() == -1)
 			log_warnx("configuration reload failed");
@@ -272,6 +273,8 @@ main(int argc, char *argv[])
 	event_dispatch();
 
 	eigrpd_shutdown();
+	/* NOTREACHED */
+	return (0);
 }
 
 __dead void
@@ -280,16 +283,16 @@ eigrpd_shutdown(void)
 	pid_t		 pid;
 	int		 status;
 
+	/* close pipes */
 	msgbuf_clear(&iev_eigrpe->ibuf.w);
-	free(iev_eigrpe);
-	iev_eigrpe = NULL;
+	close(iev_eigrpe->ibuf.fd);
 	msgbuf_clear(&iev_rde->ibuf.w);
-	free(iev_rde);
-	iev_rde = NULL;
+	close(iev_rde->ibuf.fd);
 
-	config_clear(eigrpd_conf);
 	kr_shutdown();
+	config_clear(eigrpd_conf);
 
+	log_debug("waiting for children to terminate");
 	do {
 		pid = wait(&status);
 		if (pid == -1) {
@@ -301,6 +304,9 @@ eigrpd_shutdown(void)
 			    "eigrp engine", WTERMSIG(status));
 	} while (pid != -1 || (pid == -1 && errno == EINTR));
 
+	free(iev_eigrpe);
+	free(iev_rde);
+
 	log_info("terminating");
 	exit(0);
 }

eigrpe.c

@@ -36,7 +36,7 @@
 #include "log.h"
 
 void		 eigrpe_sig_handler(int, short, void *);
-void		 eigrpe_shutdown(void);
+__dead void	 eigrpe_shutdown(void);
 
 static struct event	 ev4;
 static struct event	 ev6;
@@ -173,11 +173,18 @@ eigrpe(int debug, int verbose, char *sockname)
 	return (0);
 }
 
-void
+__dead void
 eigrpe_shutdown(void)
 {
-	control_cleanup(global.csock);
+	/* close pipes */
+	msgbuf_write(&iev_rde->ibuf.w);
+	msgbuf_clear(&iev_rde->ibuf.w);
+	close(iev_rde->ibuf.fd);
+	msgbuf_write(&iev_main->ibuf.w);
+	msgbuf_clear(&iev_main->ibuf.w);
+	close(iev_main->ibuf.fd);
 
+	control_cleanup(global.csock);
 	config_clear(econf);
 
 	event_del(&ev4);
@@ -186,11 +193,7 @@ eigrpe_shutdown(void)
 	close(global.eigrp_socket_v6);
 
 	/* clean up */
-	msgbuf_write(&iev_rde->ibuf.w);
-	msgbuf_clear(&iev_rde->ibuf.w);
 	free(iev_rde);
-	msgbuf_write(&iev_main->ibuf.w);
-	msgbuf_clear(&iev_main->ibuf.w);
 	free(iev_main);
 	free(pkt_ptr);
 

rde.c

@@ -34,7 +34,7 @@
 #include "rde.h"
 
 void		 rde_sig_handler(int sig, 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 *);
 
@@ -131,14 +131,18 @@ rde(int debug, int verbose)
 	return (0);
 }
 
-void
+__dead void
 rde_shutdown(void)
 {
+	/* close pipes */
+	msgbuf_clear(&iev_eigrpe->ibuf.w);
+	close(iev_eigrpe->ibuf.fd);
+	msgbuf_clear(&iev_main->ibuf.w);
+	close(iev_main->ibuf.fd);
+
 	config_clear(rdeconf);
 
-	msgbuf_clear(&iev_eigrpe->ibuf.w);
 	free(iev_eigrpe);
-	msgbuf_clear(&iev_main->ibuf.w);
 	free(iev_main);
 
 	log_info("route decision engine exiting");