commit 3412bd0bfb8b8bac9834cbfd3392b3d5487133bf
Author: Tom Eastep <teastep@shorewall.net>
Date:   Thu Aug 18 15:11:16 2011 -0700

    libxt_conntrack: improve error message on parsing violation
    
    Tom Eastep noted:
    
    $ iptables -A foo -m conntrack --ctorigdstport 22
    iptables v1.4.12: conntrack rev 2 does not support port ranges
    Try `iptables -h' or 'iptables --help' for more information.
    
    Commit v1.4.12-41-g1ad6407 takes care of the actual cause of the bug,
    but let's include Tom's patch nevertheless for the better error
    message in case one actually does specify a range with rev 2.
    
    References: http://marc.info/?l=netfilter-devel&m=131370592105298&w=2
    Signed-off-by: Jan Engelhardt <jengelh@medozas.de>

diff --git a/extensions/libxt_conntrack.c b/extensions/libxt_conntrack.c
index 060b947..fff69f8 100644
--- a/extensions/libxt_conntrack.c
+++ b/extensions/libxt_conntrack.c
@@ -129,13 +129,20 @@ static const struct xt_option_entry conntrack2_mt_opts[] = {
 	 .flags = XTOPT_INVERT},
 	{.name = "ctexpire", .id = O_CTEXPIRE, .type = XTTYPE_UINT32RC,
 	 .flags = XTOPT_INVERT},
-	{.name = "ctorigsrcport", .id = O_CTORIGSRCPORT, .type = XTTYPE_PORT,
+	/*
+	 * Rev 1 and 2 only store one port, and we would normally use
+	 * %XTTYPE_PORT (rather than %XTTYPE_PORTRC) for that. The resulting
+	 * error message - in case a user passed a range nevertheless -
+	 * "port 22:23 resolved to nothing" is not quite as useful as using
+	 * %XTTYPE_PORTC and libxt_conntrack's own range test.
+	 */
+	{.name = "ctorigsrcport", .id = O_CTORIGSRCPORT, .type = XTTYPE_PORTRC,
 	 .flags = XTOPT_INVERT | XTOPT_NBO},
-	{.name = "ctorigdstport", .id = O_CTORIGDSTPORT, .type = XTTYPE_PORT,
+	{.name = "ctorigdstport", .id = O_CTORIGDSTPORT, .type = XTTYPE_PORTRC,
 	 .flags = XTOPT_INVERT | XTOPT_NBO},
-	{.name = "ctreplsrcport", .id = O_CTREPLSRCPORT, .type = XTTYPE_PORT,
+	{.name = "ctreplsrcport", .id = O_CTREPLSRCPORT, .type = XTTYPE_PORTRC,
 	 .flags = XTOPT_INVERT | XTOPT_NBO},
-	{.name = "ctrepldstport", .id = O_CTREPLDSTPORT, .type = XTTYPE_PORT,
+	{.name = "ctrepldstport", .id = O_CTREPLDSTPORT, .type = XTTYPE_PORTRC,
 	 .flags = XTOPT_INVERT | XTOPT_NBO},
 	{.name = "ctdir", .id = O_CTDIR, .type = XTTYPE_STRING},
 	XTOPT_TABLEEND,