netfilter: nfnetlink_queue: get rid of nfnetlink_queue_ct.c

The original intention was to avoid dependencies between nfnetlink_queue and
conntrack without ifdef pollution. However, we can achieve this by moving the
conntrack dependent code into ctnetlink and keep some glue code to access the
nfq_ct indirection from nfqueue.

After this patch, the nfq_ct indirection is always compiled in the netfilter
core to avoid polluting nfqueue with ifdefs. Thus, if nf_conntrack is not
compiled this results in only 8-bytes of memory waste in x86_64.

This patch also adds ctnetlink_nfqueue_seqadj() to avoid that the nf_conn
structure layout if exposed to nf_queue, which creates another dependency with
nf_conntrack at compilation time.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

2 files changed, 8 insertions, 55 deletions

diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 165ab2d14734..3e5e8f2b65f6 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -369,14 +369,21 @@ nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
 extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu;
 void nf_ct_attach(struct sk_buff *, const struct sk_buff *);
 extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu;
+#else
+static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
+#endif
 
 struct nf_conn;
 enum ip_conntrack_info;
 struct nlattr;
 
 struct nfq_ct_hook {
+	struct nf_conn *(*get_ct)(struct sk_buff *skb,
+				  enum ip_conntrack_info *ctinfo);
 	size_t (*build_size)(const struct nf_conn *ct);
-	int (*build)(struct sk_buff *skb, struct nf_conn *ct);
+	int (*build)(struct sk_buff *skb, struct nf_conn *ct,
+		     enum ip_conntrack_info ctinfo,
+		     u_int16_t ct_attr, u_int16_t ct_info_attr);
 	int (*parse)(const struct nlattr *attr, struct nf_conn *ct);
 	int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct,
 			     u32 portid, u32 report);
@@ -384,9 +391,6 @@ struct nfq_ct_hook {
 			   enum ip_conntrack_info ctinfo, s32 off);
 };
 extern struct nfq_ct_hook __rcu *nfq_ct_hook;
-#else
-static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
-#endif
 
 /**
  * nf_skb_duplicated - TEE target has sent a packet
diff --git a/include/net/netfilter/nfnetlink_queue.h b/include/net/netfilter/nfnetlink_queue.h
deleted file mode 100644
index aff88ba91391..000000000000
--- a/include/net/netfilter/nfnetlink_queue.h
+++ /dev/null
@@ -1,51 +0,0 @@
-#ifndef _NET_NFNL_QUEUE_H_
-#define _NET_NFNL_QUEUE_H_
-
-#include <linux/netfilter/nf_conntrack_common.h>
-
-struct nf_conn;
-
-#ifdef CONFIG_NETFILTER_NETLINK_QUEUE_CT
-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);
-int nfqnl_attach_expect(struct nf_conn *ct, const struct nlattr *attr,
-			u32 portid, u32 report);
-#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)
-{
-}
-
-inline int nfqnl_attach_expect(struct nf_conn *ct, const struct nlattr *attr,
-			       u32 portid, u32 report)
-{
-	return 0;
-}
-#endif /* NF_CONNTRACK */
-#endif