netfilter: nfnetlink_queue: fix compilation with NF_CONNTRACK disabled

In "9cb0176 netfilter: add glue code to integrate nfnetlink_queue and ctnetlink"
the compilation with NF_CONNTRACK disabled is broken. This patch fixes this
issue.

I have moved the conntrack part into nfnetlink_queue_ct.c to avoid
peppering the entire nfnetlink_queue.c code with ifdefs.

I also needed to rename nfnetlink_queue.c to nfnetlink_queue_pkt.c
to update the net/netfilter/Makefile to support conditional compilation
of the conntrack integration.

This patch also adds CONFIG_NETFILTER_QUEUE_CT in case you want to explicitly
disable the integration between nf_conntrack and nfnetlink_queue.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 43 insertions, 0 deletions

diff --git a/include/net/netfilter/nfnetlink_queue.h b/include/net/netfilter/nfnetlink_queue.h
new file mode 100644
index 00000000000..9f8095c108e
--- /dev/null
+++ b/include/net/netfilter/nfnetlink_queue.h
@@ -0,0 +1,43 @@
+#ifndef _NET_NFNL_QUEUE_H_
+#define _NET_NFNL_QUEUE_H_
+
+#include <linux/netfilter/nf_conntrack_common.h>
+
+struct nf_conn;
+
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+struct nf_conn *nfqnl_ct_get(struct sk_buff *entskb, size_t *size,
+			     enum ip_conntrack_info *ctinfo);
+struct nf_conn *nfqnl_ct_parse(const struct sk_buff *skb,
+			       const struct nlattr *attr,
+			       enum ip_conntrack_info *ctinfo);
+int nfqnl_ct_put(struct sk_buff *skb, struct nf_conn *ct,
+		 enum ip_conntrack_info ctinfo);
+void nfqnl_ct_seq_adjust(struct sk_buff *skb, struct nf_conn *ct,
+			 enum ip_conntrack_info ctinfo, int diff);
+#else
+inline struct nf_conn *
+nfqnl_ct_get(struct sk_buff *entskb, size_t *size, enum ip_conntrack_info *ctinfo)
+{
+	return NULL;
+}
+
+inline struct nf_conn *nfqnl_ct_parse(const struct sk_buff *skb,
+				      const struct nlattr *attr,
+				      enum ip_conntrack_info *ctinfo)
+{
+	return NULL;
+}
+
+inline int
+nfqnl_ct_put(struct sk_buff *skb, struct nf_conn *ct, enum ip_conntrack_info ctinfo)
+{
+	return 0;
+}
+
+inline void nfqnl_ct_seq_adjust(struct sk_buff *skb, struct nf_conn *ct,
+				enum ip_conntrack_info ctinfo, int diff)
+{
+}
+#endif /* NF_CONNTRACK */
+#endif