netfilter: nft: add queue module

This patch adds a new nft module named "nft_queue" which provides
a new nftables expression that allows you to enqueue packets to
userspace via the nfnetlink_queue subsystem. It provides the same
level of functionality as NFQUEUE and it shares some code with it.

Signed-off-by: Eric Leblond <eric@regit.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 48acec1..4371c98 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -456,6 +456,15 @@
 	depends on NF_NAT
 	tristate "Netfilter nf_tables nat module"
 
+config NFT_QUEUE
+	depends on NF_TABLES
+	depends on NETFILTER_XTABLES
+	depends on NETFILTER_NETLINK_QUEUE
+	tristate "Netfilter nf_tables queue module"
+	help
+	  This is required if you intend to use the userspace queueing
+	  infrastructure (also known as NFQUEUE) from nftables.
+
 config NFT_COMPAT
 	depends on NF_TABLES
 	depends on NETFILTER_XTABLES