diff -ur tcp_wrappers_7.6/rfc931.c tcp_wrappers_7.6.alarm/rfc931.c
--- tcp_wrappers_7.6/rfc931.c	Tue May  1 23:14:34 2001
+++ tcp_wrappers_7.6.alarm/rfc931.c	Tue May  1 23:13:56 2001
@@ -20,7 +20,6 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
-#include <setjmp.h>
 #include <signal.h>
 #include <string.h>
 
@@ -33,7 +32,8 @@
 
 int     rfc931_timeout = RFC931_TIMEOUT;/* Global so it can be changed */
 
-static sigjmp_buf timebuf;
+struct sigaction oldact;
+int	restored = 0;
 
 /* fsocket - open stdio stream on top of socket */
 
@@ -59,10 +59,10 @@
 
 /* timeout - handle timeouts */
 
-static void timeout(sig)
-int     sig;
+static void timeout(int signum)
 {
-    siglongjmp(timebuf, sig);
+	sigaction(SIGALRM,&oldact,NULL);
+	restored = 1;
 }
 
 /* rfc931 - return remote user name, given socket structures */
@@ -92,6 +92,8 @@
     char   *cp;
     char   *result = unknown;
     FILE   *fp;
+    int    old_alarm;
+    struct sigaction act;
 
 #ifdef INET6
     /* address family must be the same */
@@ -133,9 +135,18 @@
 	 * Set up a timer so we won't get stuck while waiting for the server.
 	 */
 
-	if (sigsetjmp(timebuf,1) == 0) {
-	    signal(SIGALRM, timeout);
-	    alarm(rfc931_timeout);
+	act.sa_handler = timeout;
+	sigemptyset(&act.sa_mask);
+	act.sa_flags = 0;
+#ifdef SA_INTERRUPT
+	act.sa_flags |= SA_INTERRUPT;
+#endif
+	sigaction(SIGALRM,&act,&oldact);
+	restored = 0;
+#ifdef HAVE_SIGINTERRUPT
+	siginterrupt(SIGALRM,1);
+#endif
+	old_alarm = alarm(rfc931_timeout);
 
 	    /*
 	     * Bind the local and remote ends of the query socket to the same
@@ -221,8 +232,11 @@
 		    result = user;
 		}
 	    }
-	    alarm(0);
+	if (!restored) {
+		sigaction(SIGALRM,&oldact,NULL);
+		restored = 1;
 	}
+	alarm(old_alarm);
 	fclose(fp);
     }
     STRN_CPY(dest, result, STRING_LENGTH);