netfilter: nf_conntrack: push zone object into functions

This patch replaces the zone id which is pushed down into functions
with the actual zone object. It's a bigger one-time change, but
needed for later on extending zones with a direction parameter, and
thus decoupling this additional information from all call-sites.

No functional changes in this patch.

The default zone becomes a global const object, namely nf_ct_zone_dflt
and will be returned directly in various cases, one being, when there's
f.e. no zoning support.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

4 files changed, 41 insertions, 16 deletions

diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index 37cd391..f5e23c6 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -250,8 +250,12 @@ void nf_ct_untracked_status_or(unsigned long bits);
 void nf_ct_iterate_cleanup(struct net *net,
 			   int (*iter)(struct nf_conn *i, void *data),
 			   void *data, u32 portid, int report);
+
+struct nf_conntrack_zone;
+
 void nf_conntrack_free(struct nf_conn *ct);
-struct nf_conn *nf_conntrack_alloc(struct net *net, u16 zone,
+struct nf_conn *nf_conntrack_alloc(struct net *net,
+				   const struct nf_conntrack_zone *zone,
 				   const struct nf_conntrack_tuple *orig,
 				   const struct nf_conntrack_tuple *repl,
 				   gfp_t gfp);
@@ -291,7 +295,9 @@ extern unsigned int nf_conntrack_max;
 extern unsigned int nf_conntrack_hash_rnd;
 void init_nf_conntrack_hash_rnd(void);
 
-struct nf_conn *nf_ct_tmpl_alloc(struct net *net, u16 zone, gfp_t flags);
+struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
+				 const struct nf_conntrack_zone *zone,
+				 gfp_t flags);
 
 #define NF_CT_STAT_INC(net, count)	  __this_cpu_inc((net)->ct.stat->count)
 #define NF_CT_STAT_INC_ATOMIC(net, count) this_cpu_inc((net)->ct.stat->count)
diff --git a/include/net/netfilter/nf_conntrack_core.h b/include/net/netfilter/nf_conntrack_core.h
index f2f0fa3..c03f9c4 100644
--- a/include/net/netfilter/nf_conntrack_core.h
+++ b/include/net/netfilter/nf_conntrack_core.h
@@ -52,7 +52,8 @@ bool nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
 
 /* Find a connection corresponding to a tuple. */
 struct nf_conntrack_tuple_hash *
-nf_conntrack_find_get(struct net *net, u16 zone,
+nf_conntrack_find_get(struct net *net,
+		      const struct nf_conntrack_zone *zone,
 		      const struct nf_conntrack_tuple *tuple);
 
 int __nf_conntrack_confirm(struct sk_buff *skb);
diff --git a/include/net/netfilter/nf_conntrack_expect.h b/include/net/netfilter/nf_conntrack_expect.h
index 3f3aecb..dce56f0 100644
--- a/include/net/netfilter/nf_conntrack_expect.h
+++ b/include/net/netfilter/nf_conntrack_expect.h
@@ -4,7 +4,9 @@
 
 #ifndef _NF_CONNTRACK_EXPECT_H
 #define _NF_CONNTRACK_EXPECT_H
+
 #include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_zones.h>
 
 extern unsigned int nf_ct_expect_hsize;
 extern unsigned int nf_ct_expect_max;
@@ -76,15 +78,18 @@ int nf_conntrack_expect_init(void);
 void nf_conntrack_expect_fini(void);
 
 struct nf_conntrack_expect *
-__nf_ct_expect_find(struct net *net, u16 zone,
+__nf_ct_expect_find(struct net *net,
+		    const struct nf_conntrack_zone *zone,
 		    const struct nf_conntrack_tuple *tuple);
 
 struct nf_conntrack_expect *
-nf_ct_expect_find_get(struct net *net, u16 zone,
+nf_ct_expect_find_get(struct net *net,
+		      const struct nf_conntrack_zone *zone,
 		      const struct nf_conntrack_tuple *tuple);
 
 struct nf_conntrack_expect *
-nf_ct_find_expectation(struct net *net, u16 zone,
+nf_ct_find_expectation(struct net *net,
+		       const struct nf_conntrack_zone *zone,
 		       const struct nf_conntrack_tuple *tuple);
 
 void nf_ct_unlink_expect_report(struct nf_conntrack_expect *exp,
diff --git a/include/net/netfilter/nf_conntrack_zones.h b/include/net/netfilter/nf_conntrack_zones.h
index 034efe8..0788bb0 100644
--- a/include/net/netfilter/nf_conntrack_zones.h
+++ b/include/net/netfilter/nf_conntrack_zones.h
@@ -1,25 +1,38 @@
 #ifndef _NF_CONNTRACK_ZONES_H
 #define _NF_CONNTRACK_ZONES_H
 
-#define NF_CT_DEFAULT_ZONE	0
-
-#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
-#include <net/netfilter/nf_conntrack_extend.h>
+#define NF_CT_DEFAULT_ZONE_ID	0
 
 struct nf_conntrack_zone {
 	u16	id;
 };
 
-static inline u16 nf_ct_zone(const struct nf_conn *ct)
+extern const struct nf_conntrack_zone nf_ct_zone_dflt;
+
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+#include <net/netfilter/nf_conntrack_extend.h>
+
+static inline const struct nf_conntrack_zone *
+nf_ct_zone(const struct nf_conn *ct)
 {
+	const struct nf_conntrack_zone *nf_ct_zone = NULL;
+
 #ifdef CONFIG_NF_CONNTRACK_ZONES
-	struct nf_conntrack_zone *nf_ct_zone;
 	nf_ct_zone = nf_ct_ext_find(ct, NF_CT_EXT_ZONE);
-	if (nf_ct_zone)
-		return nf_ct_zone->id;
 #endif
-	return NF_CT_DEFAULT_ZONE;
+	return nf_ct_zone ? nf_ct_zone : &nf_ct_zone_dflt;
 }
 
-#endif /* CONFIG_NF_CONNTRACK || CONFIG_NF_CONNTRACK_MODULE */
+static inline const struct nf_conntrack_zone *
+nf_ct_zone_tmpl(const struct nf_conn *tmpl)
+{
+	return tmpl ? nf_ct_zone(tmpl) : &nf_ct_zone_dflt;
+}
+
+static inline bool nf_ct_zone_equal(const struct nf_conn *a,
+				    const struct nf_conntrack_zone *b)
+{
+	return nf_ct_zone(a)->id == b->id;
+}
+#endif /* IS_ENABLED(CONFIG_NF_CONNTRACK) */
 #endif /* _NF_CONNTRACK_ZONES_H */