Fix a problem introduced with a recent change that caused a hang with

unreachable hosts.  Note that most of this consists of telling SIGINT
and SIGALRM to interrupt the system call, instead of restarting them.
Also try to get rid of some potential races Bruce didn't like; hopefully
they aren't a problem (potential or otherwise) now.

Reviewed by:	julian

1 files changed, 28 insertions, 10 deletions

diff --git a/sbin/ping/ping.c b/sbin/ping/ping.c
index 5f89641..5479d64 100644
--- a/sbin/ping/ping.c
+++ b/sbin/ping/ping.c
@@ -45,7 +45,7 @@ static const char copyright[] =
 static char sccsid[] = "@(#)ping.c	8.1 (Berkeley) 6/5/93";
 */
 static const char rcsid[] =
-	"$Id: ping.c,v 1.22 1997/07/09 19:40:43 julian Exp $";
+	"$Id: ping.c,v 1.23 1997/07/09 20:33:58 julian Exp $";
 #endif /* not lint */
 
 /*
@@ -423,16 +423,25 @@ main(argc, argv)
 	else
 		(void)printf("PING %s: %d data bytes\n", hostname, datalen);
 
-	(void)signal(SIGINT, stopit);
-	(void)signal(SIGALRM, catcher);
-
 	/*
-	 * Use sigaction instead of signal() to get unambiguous semantics
-	 * for SIGINFO, in particular with SA_RESTART not set.
+	 * Use sigaction() instead of signal() to get unambiguous semantics,
+	 * in particular with SA_RESTART not set.
 	 */
-	si_sa.sa_handler = status;
+
 	sigemptyset(&si_sa.sa_mask);
 	si_sa.sa_flags = 0;
+
+	si_sa.sa_handler = stopit;
+	if (sigaction(SIGINT, &si_sa, 0) == -1) {
+		err(EX_OSERR, "sigaction SIGINT");
+	}
+
+	si_sa.sa_handler = catcher;
+	if (sigaction(SIGALRM, &si_sa, 0) == -1) {
+		err(EX_OSERR, "sigaction SIGALRM");
+	}
+
+	si_sa.sa_handler = status;
 	if (sigaction(SIGINFO, &si_sa, 0) == -1) {
 		err(EX_OSERR, "sigaction");
 	}
@@ -508,11 +517,12 @@ static void
 catcher(int sig)
 {
 	int waittime;
+	struct sigaction si_sa;
 
 	pinger();
-	(void)signal(SIGALRM, catcher);
+
 	if (!npackets || ntransmitted < npackets)
-		alarm((u_int)interval);
+		(void)alarm((u_int)interval);
 	else {
 		if (nreceived) {
 			waittime = 2 * tmax / 1000;
@@ -520,7 +530,14 @@ catcher(int sig)
 				waittime = 1;
 		} else
 			waittime = MAXWAIT;
-		(void)signal(SIGALRM, stopit);
+
+		si_sa.sa_handler = stopit;
+		sigemptyset(&si_sa.sa_mask);
+		si_sa.sa_flags = 0;
+		if (sigaction(SIGALRM, &si_sa, 0) == -1) {
+			finish_up = 1;
+			return;
+		}
 		(void)alarm((u_int)waittime);
 	}
 }
@@ -889,6 +906,7 @@ finish(int sig)
 	struct termios ts;
 
 	(void)signal(SIGINT, SIG_IGN);
+	(void)signal(SIGALRM, SIG_IGN);
 	(void)putchar('\n');
 	(void)fflush(stdout);
 	(void)printf("--- %s ping statistics ---\n", hostname);