Implement -R support, similar to ping(8)'s -A.

ping(8)'s -a was mapped to -e, but -E was already taken in ping6 (old
option) so rename -e to -r.
Now:
ping -a => ping6 -r
ping -A => ping6 -R

MFC after:	2 days

sbin/ping6/ping6.8

@@ -29,7 +29,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd August 26, 2008
+.Dd August 27, 2008
 .Dt PING6 8
 .Os
 .Sh NAME
@@ -40,7 +40,7 @@ packets to network hosts
 .Sh SYNOPSIS
 .Nm
 .\" without ipsec, or new ipsec
-.Op Fl defHmnNoqtvwW
+.Op Fl dfHmnNoqrRtvwW
 .\" old ipsec
 .\" .Op Fl AdEfmnNqRtvwW
 .Bk -words
@@ -148,12 +148,6 @@ option on the socket being used.
 .\" .It Fl E
 .\" Enables transport-mode IPsec encapsulated security payload
 .\" (experimental).
-.It Fl e
-Audible.
-Include a bell
-.Tn ( ASCII
-0x07)
-character in the output when any packet is received.
 .It Fl f
 Flood ping.
 Outputs packets as fast as they come back or one hundred times per second,
@@ -250,6 +244,22 @@ specifies IPsec policy to be used for the probe.
 Quiet output.
 Nothing is displayed except the summary lines at startup time and
 when finished.
+.It Fl r
+Audible.
+Include a bell
+.Tn ( ASCII
+0x07)
+character in the output when any packet is received.
+.It Fl R
+Audible.
+Output a bell
+.Tn ( ASCII
+0x07)
+character when no packet is received before the next packet
+is transmitted.
+To cater for round-trip times that are longer than the interval
+between transmissions, further missing packets cause a bell only
+if the maximum number of unreceived packets has increased.
 .It Fl S Ar sourceaddr
 Specifies the source address of request packets.
 The source address must be one of the unicast addresses of the sending node,

sbin/ping6/ping6.c

@@ -190,6 +190,7 @@ struct tv32 {
 #define F_NOMINMTU	0x100000
 #define F_ONCE		0x200000
 #define F_AUDIBLE	0x400000
+#define F_MISSED	0x800000
 #define F_NOUSERDATA	(F_NODEADDR | F_FQDN | F_FQDNOLD | F_SUPTYPES)
 u_int options;
 
@@ -225,6 +226,7 @@ int hoplimit = -1;		/* hoplimit */
 int pathmtu = 0;		/* path MTU for the destination.  0 = unspec. */
 
 /* counters */
+long nmissedmax;		/* max value of ntransmitted - nreceived - 1 */
 long npackets;			/* max packets to transmit */
 long nreceived;			/* # of packets we got back */
 long nrepeats;			/* number of duplicates */
@@ -347,7 +349,7 @@ main(argc, argv)
 #endif /*IPSEC_POLICY_IPSEC*/
 #endif
 	while ((ch = getopt(argc, argv,
-	    "a:b:c:defHg:h:I:i:l:mnNop:qS:s:tvwW" ADDOPTS)) != -1) {
+	    "a:b:c:dfHg:h:I:i:l:mnNop:qrRS:s:tvwW" ADDOPTS)) != -1) {
 #undef ADDOPTS
 		switch (ch) {
 		case 'a':
@@ -416,9 +418,6 @@ main(argc, argv)
 		case 'd':
 			options |= F_SO_DEBUG;
 			break;
-		case 'e':
-			options |= F_AUDIBLE;
-			break;
 		case 'f':
 			if (getuid()) {
 				errno = EPERM;
@@ -501,6 +500,12 @@ main(argc, argv)
 		case 'q':
 			options |= F_QUIET;
 			break;
+		case 'r':
+			options |= F_AUDIBLE;
+			break;
+		case 'R':
+			options |= F_MISSED;
+			break;
 		case 'S':
 			memset(&hints, 0, sizeof(struct addrinfo));
 			hints.ai_flags = AI_NUMERICHOST; /* allow hostname? */
@@ -1179,6 +1184,11 @@ main(argc, argv)
 		if (((options & F_ONCE) != 0 && nreceived > 0) ||
 		    (npackets > 0 && nreceived >= npackets))
 			break;
+		if (ntransmitted - nreceived - 1 > nmissedmax) {
+			nmissedmax = ntransmitted - nreceived - 1;
+			if (options & F_MISSED)
+				(void)write(STDOUT_FILENO, &BBELL, 1);
+		}
 	}
 	summary();
 	exit(nreceived == 0 ? 2 : 0);
@@ -2770,7 +2780,7 @@ usage()
 	    "A"
 #endif
 	    "usage: ping6 [-"
-	    "de"
+	    "d"
 #if defined(IPSEC) && !defined(IPSEC_POLICY_IPSEC)
 	    "E"
 #endif
@@ -2778,7 +2788,7 @@ usage()
 #ifdef IPV6_USE_MIN_MTU
 	    "m"
 #endif
-	    "nNoqtvwW] "
+	    "nNoqrRtvwW] "
 	    "[-a addrtype] [-b bufsiz] [-c count] [-g gateway]\n"
 	    "             [-h hoplimit] [-I interface] [-i wait] [-l preload]"
 #if defined(IPSEC) && defined(IPSEC_POLICY_IPSEC)