ping: By default, don't reverse lookup IP addresses

ping's default is now not to attempt reverse DNS lookups.  The -H flag will
enable them.  This change is not quite a reversion of r351330.  That change
made the happy path and error path do reverse lookups consistently; this
change changes the default for both paths.

Submitted by:	Ján Sučan <sucanjan@gmail.com>
Discussed with:	cem
MFC after:	2 weeks
MFC-With:	351330
Sponsored by:	Google LLC (Google Summer of Code 2019)
Differential Revision:	https://reviews.freebsd.org/D21364

sbin/ping/ping.8

@@ -28,7 +28,7 @@
 .\"     @(#)ping.8	8.2 (Berkeley) 12/11/93
 .\" $FreeBSD$
 .\"
-.Dd August 21, 2019
+.Dd August 22, 2019
 .Dt PING 8
 .Os
 .Sh NAME
@@ -160,11 +160,9 @@ The default value is 0.
 .It Fl H
 Hostname output.
 Try to do a reverse DNS lookup when displaying addresses.
-This is the opposite of
-.Fl n ,
-and it is the default behavior.
-.Nm
-utility tries reverse-lookup by default.
+This is the opposite of the
+.Fl n
+option.
 .It Fl h Ar sweepincrsize
 Specify the number of bytes to increment the size of
 .Tn ICMP
@@ -228,6 +226,9 @@ MIB variable.
 .It Fl n
 Numeric output only.
 No attempt will be made to lookup symbolic names for host addresses.
+This is the opposite of
+.Fl H ,
+and it is the default behavior.
 .It Fl o
 Exit successfully after receiving one reply packet.
 .It Fl P Ar policy

sbin/ping/ping.c

@@ -261,6 +261,8 @@ main(int argc, char *const *argv)
 #endif
 	cap_rights_t rights;
 
+	options |= F_NUMERIC;
+
 	/*
 	 * Do the stuff that we need root priv's for *first*, and
 	 * then drop our setuid bit.  Save error reporting for

sbin/ping/tests/ping_c1_s56_t1.out

@@ -1,5 +1,5 @@
 PING localhost: 56 data bytes
-64 bytes from localhost: icmp_seq=0 ttl= time= ms
+64 bytes from: icmp_seq=0 ttl= time= ms
 
 --- localhost ping statistics ---
 1 packets transmitted, 1 packets received, 0.0% packet loss