chore: import upstream snapshot with attribution

nis/save_client.cgi

@@ -0,0 +1,31 @@
+#!/usr/local/bin/perl
+# save_client.cgi
+# Save and apply NIS client options
+
+require './nis-lib.pl';
+&ReadParse();
+&error_setup($text{'client_err'});
+
+# Parse and validate inputs
+if (!$in{'domain_def'}) {
+	$in{'domain'} =~ /^[A-Za-z0-9\.\-]+$/ ||
+		&error($text{'client_edomain'});
+	$nis->{'domain'} = $in{'domain'};
+	}
+if ($in{'broadcast'}) {
+	$nis->{'broadcast'} = 1;
+	}
+else {
+	@servers = split(/\s+/, $in{'servers'});
+	foreach $s (@servers) {
+		&to_ipaddress($s) || &to_ip6address($s) ||
+			&error(&text('client_eserver', $s));
+		}
+	$nis->{'servers'} = \@servers;
+	}
+
+# Save and apply
+$err = &save_client_config($nis);
+if ($err) { &error($err); }
+&redirect("");
+