Chain name should not start with '!' (Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>)
diff --git a/iptables.c b/iptables.c
index 33ee337..f8250ce 100644
--- a/iptables.c
+++ b/iptables.c
@@ -1925,10 +1925,10 @@
 			break;
 
 		case 'N':
-			if (optarg && *optarg == '-')
+			if (optarg && (*optarg == '-' || *optarg == '!'))
 				exit_error(PARAMETER_PROBLEM,
 					   "chain name not allowed to start "
-					   "with `-'\n");
+					   "with `%c'\n", *optarg);
 			if (find_target(optarg, TRY_LOAD))
 				exit_error(PARAMETER_PROBLEM,
 					   "chain name may not clash "