Re: Last night Linus bk - netfilter busted?

From: Patrick McHardy
Date: Fri Mar 11 2005 - 16:00:23 EST


David S. Miller wrote:
Damn, wait, Patrick, I think I know what's happening. The iptables
IPT_* verdicts are dependant upon the NF_* values, and they don't
cope with Bart's changes I bet. Can you figure out what the exact
error would be? This kind of issue would explain the looping inside
of ipt_do_table(), wouldn't it?

You're right, good catch. IPT_RETURN is interpreted internally by
ip_tables, but since the value changed it isn't recognized by ip_tables
anymore and returned to nf_iterate() as NF_REPEAT. This patch restores
the old value.

# This is a BitKeeper generated diff -Nru style patch.
#
# ChangeSet
# 2005/03/11 21:41:01+01:00 kaber@xxxxxxxxxxxx
# [NETFILTER]: Fix iptables userspace compatibility breakage
#
# Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx>
#
# include/linux/netfilter_ipv6/ip6_tables.h
# 2005/03/11 21:40:52+01:00 kaber@xxxxxxxxxxxx +1 -1
# [NETFILTER]: Fix iptables userspace compatibility breakage
#
# Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx>
#
# include/linux/netfilter_ipv4/ip_tables.h
# 2005/03/11 21:40:52+01:00 kaber@xxxxxxxxxxxx +1 -1
# [NETFILTER]: Fix iptables userspace compatibility breakage
#
# Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx>
#
diff -Nru a/include/linux/netfilter_ipv4/ip_tables.h b/include/linux/netfilter_ipv4/ip_tables.h
--- a/include/linux/netfilter_ipv4/ip_tables.h 2005-03-11 21:41:32 +01:00
+++ b/include/linux/netfilter_ipv4/ip_tables.h 2005-03-11 21:41:32 +01:00
@@ -166,7 +166,7 @@
#define IPT_CONTINUE 0xFFFFFFFF

/* For standard target */
-#define IPT_RETURN (-NF_MAX_VERDICT - 1)
+#define IPT_RETURN (-NF_REPEAT - 1)

/* TCP matching stuff */
struct ipt_tcp
diff -Nru a/include/linux/netfilter_ipv6/ip6_tables.h b/include/linux/netfilter_ipv6/ip6_tables.h
--- a/include/linux/netfilter_ipv6/ip6_tables.h 2005-03-11 21:41:32 +01:00
+++ b/include/linux/netfilter_ipv6/ip6_tables.h 2005-03-11 21:41:32 +01:00
@@ -166,7 +166,7 @@
#define IP6T_CONTINUE 0xFFFFFFFF

/* For standard target */
-#define IP6T_RETURN (-NF_MAX_VERDICT - 1)
+#define IP6T_RETURN (-NF_REPEAT - 1)

/* TCP matching stuff */
struct ip6t_tcp