check_tcp: only test ipv6 if ping6 works

plugins/t/check_tcp.t

@@ -9,7 +9,18 @@ use Test;
 use NPTest;
 
 use vars qw($tests);
-BEGIN {$tests = 14; plan tests => $tests}
+my $has_ipv6;
+BEGIN {
+  $tests = 11;
+  # do we have ipv6
+  `ping6 -c 1 2a02:2e0:3fe:100::7 2>&1`;
+  if($? == 0) {
+    $has_ipv6 = 1;
+    $tests += 3;
+  }
+  plan tests => $tests;
+}
+
 
 my $host_tcp_http      = getTestParameter( "host_tcp_http",      "NP_HOST_TCP_HTTP",      "localhost",
 					   "A host providing the HTTP Service (a web server)" );
@@ -27,7 +38,6 @@ my $failedExpect = '/^TCP WARNING\s-\sUnexpected response from host/socket on po
 my $t;
 
 $t += checkCmd( "./check_tcp $host_tcp_http      -p 80 -wt 300 -ct 600",       0, $successOutput );
-$t += checkCmd( "./check_tcp $host_tcp_http      -p 80 -wt 300 -ct 600 -6 ",   0, $successOutput );
 $t += checkCmd( "./check_tcp $host_tcp_http      -p 81 -wt   0 -ct   0 -to 1", 2 ); # use invalid port for this test
 $t += checkCmd( "./check_tcp $host_nonresponsive -p 80 -wt   0 -ct   0 -to 1", 2 );
 $t += checkCmd( "./check_tcp $hostname_invalid   -p 80 -wt   0 -ct   0 -to 1", 2 );
@@ -35,11 +45,16 @@ $t += checkCmd( "./check_tcp -S -D 1 -H www.verisign.com -p 443",              0
 $t += checkCmd( "./check_tcp -S -D 9000,1    -H www.verisign.com -p 443",      1 );
 $t += checkCmd( "./check_tcp -S -D 9000      -H www.verisign.com -p 443",      1 );
 $t += checkCmd( "./check_tcp -S -D 9000,8999 -H www.verisign.com -p 443",      2 );
-$t += checkCmd( "./check_tcp -6 -p 80 www.heise.de",                           0 );
 
 # Need the \r\n to make it more standards compliant with web servers. Need the various quotes
 # so that perl doesn't interpret the \r\n and is passed onto command line correctly
 $t += checkCmd( "./check_tcp $host_tcp_http      -p 80 -E -s ".'"GET / HTTP/1.1\r\n\r\n"'." -e 'ThisShouldntMatch' -j", 1, $failedExpect );
 
+# IPv6 checks
+if($has_ipv6) {
+  $t += checkCmd( "./check_tcp $host_tcp_http      -p 80 -wt 300 -ct 600 -6 ",   0, $successOutput );
+  $t += checkCmd( "./check_tcp -6 -p 80 www.heise.de",                           0 );
+}
+
 exit(0) if defined($Test::Harness::VERSION);
 exit($tests - $t);