Commit 08a7f5d3 authored Feb 05, 2016 by Arnd Bergmann Committed by Pablo Neira Ayuso Feb 08, 2016

netfilter: tee: select NF_DUP_IPV6 unconditionally



The NETFILTER_XT_TARGET_TEE option selects NF_DUP_IPV6 whenever
IP6_NF_IPTABLES is enabled, and it ensures that it cannot be
builtin itself if NF_CONNTRACK is a loadable module, as that
is a dependency for NF_DUP_IPV6.

However, NF_DUP_IPV6 can be enabled even if IP6_NF_IPTABLES is
turned off, and it only really depends on IPV6. With the current
check in tee_tg6, we call nf_dup_ipv6() whenever NF_DUP_IPV6
is enabled. This can however be a loadable module which is
unreachable from a built-in xt_TEE:

net/built-in.o: In function `tee_tg6':
:(.text+0x67728): undefined reference to `nf_dup_ipv6'

The bug was originally introduced in the split of the xt_TEE module
into separate modules for ipv4 and ipv6, and two patches tried
to fix it unsuccessfully afterwards.

This is a revert of the the first incorrect attempt to fix it,
going back to depending on IPV6 as the dependency, and we
adapt the 'select' condition accordingly.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: bbde9fc1 ("netfilter: factor out packet duplication for IPv4/IPv6")
Fixes: 116984a3 ("netfilter: xt_TEE: use IS_ENABLED(CONFIG_NF_DUP_IPV6)")
Fixes: 74ec4d55 ("netfilter: fix xt_TEE and xt_TPROXY dependencies")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

parent c58d6c93

net/netfilter/Kconfig

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -891,7 +891,7 @@ config NETFILTER_XT_TARGET_TEE
	depends on IPV6 \|\| IPV6=n		depends on IPV6 \|\| IPV6=n
	depends on !NF_CONNTRACK \|\| NF_CONNTRACK		depends on !NF_CONNTRACK \|\| NF_CONNTRACK
	select NF_DUP_IPV4		select NF_DUP_IPV4
	select NF_DUP_IPV6 if IP6_NF_IPTABLES != n		select NF_DUP_IPV6 if IPV6
	---help---		---help---
	This option adds a "TEE" target with which a packet can be cloned and		This option adds a "TEE" target with which a packet can be cloned and
	this clone be rerouted to another nexthop.		this clone be rerouted to another nexthop.

net/netfilter/xt_TEE.c

+2 −2

Original line number	Original line	Diff line number	Diff line
	@@ -38,7 +38,7 @@ tee_tg4(struct sk_buff skb, const struct xt_action_param par)
	return XT_CONTINUE;		return XT_CONTINUE;
	}		}

	#if IS_ENABLED(CONFIG_NF_DUP_IPV6)		#if IS_ENABLED(CONFIG_IPV6)
	static unsigned int		static unsigned int
	tee_tg6(struct sk_buff skb, const struct xt_action_param par)		tee_tg6(struct sk_buff skb, const struct xt_action_param par)
	{		{
	@@ -131,7 +131,7 @@ static struct xt_target tee_tg_reg[] __read_mostly = {
	.destroy = tee_tg_destroy,		.destroy = tee_tg_destroy,
	.me = THIS_MODULE,		.me = THIS_MODULE,
	},		},
	#if IS_ENABLED(CONFIG_NF_DUP_IPV6)		#if IS_ENABLED(CONFIG_IPV6)
	{		{
	.name = "TEE",		.name = "TEE",
	.revision = 1,		.revision = 1,

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