conntrackd: generalize caching infrastructure

This patch generalizes the caching infrastructure to store different
object types. This patch is the first in the series to prepare
support for the synchronization of expectations.

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

2 files changed, 66 insertions, 18 deletions

diff --git a/include/cache.h b/include/cache.h
index ddf2049..a42e395 100644
--- a/include/cache.h
+++ b/include/cache.h
@@ -27,7 +27,7 @@ enum {
 struct cache;
 struct cache_object {
 	struct	hashtable_node hashnode;
-	struct	nf_conntrack *ct;
+	void	*ptr;
 	struct	cache *cache;
 	int	status;
 	int	refcnt;
@@ -48,14 +48,22 @@ extern struct cache_feature timer_feature;
 
 #define CACHE_MAX_NAMELEN 32
 
+enum cache_type {
+	CACHE_T_NONE = 0,
+	CACHE_T_CT,
+	CACHE_T_MAX
+};
+
 struct cache {
 	char name[CACHE_MAX_NAMELEN];
+	enum cache_type type;
 	struct hashtable *h;
 
 	unsigned int num_features;
 	struct cache_feature **features;
 	unsigned int feature_type[CACHE_MAX_FEATURE];
 	unsigned int *feature_offset;
+	struct cache_ops *ops;
 	struct cache_extra *extra;
 	unsigned int extra_offset;
 	size_t object_size;
@@ -94,22 +102,48 @@ struct cache_extra {
 	void (*destroy)(struct cache_object *obj, void *data);
 };
 
+struct nfct_handle;
+
+/* cache options depends on the object type: conntrack or expectation. */
+struct cache_ops {
+	/* hashing and comparison of objects. */
+	uint32_t (*hash)(const void *data, const struct hashtable *table);
+	int (*cmp)(const void *data1, const void *data2);
+
+	/* object allocation, copy and release. */
+	void *(*alloc)(void);
+	void (*copy)(void *dst, void *src, unsigned int flags);
+	void (*free)(void *ptr);
+
+	/* dump and commit. */
+	int (*dump_step)(void *data1, void *n);
+	int (*commit)(struct cache *c, struct nfct_handle *h, int clientfd);
+
+	/* build network message from object. */
+	struct nethdr *(*build_msg)(const struct cache_object *obj, int type);
+};
+
+/* templates to configure conntrack caching. */
+extern struct cache_ops cache_sync_internal_ct_ops;
+extern struct cache_ops cache_sync_external_ct_ops;
+extern struct cache_ops cache_stats_ct_ops;
+
 struct nf_conntrack;
 
-struct cache *cache_create(const char *name, unsigned int features, struct cache_extra *extra);
+struct cache *cache_create(const char *name, enum cache_type type, unsigned int features, struct cache_extra *extra, struct cache_ops *ops);
 void cache_destroy(struct cache *e);
 
-struct cache_object *cache_object_new(struct cache *c, struct nf_conntrack *ct);
+struct cache_object *cache_object_new(struct cache *c, void *ptr);
 void cache_object_free(struct cache_object *obj);
 void cache_object_get(struct cache_object *obj);
 int cache_object_put(struct cache_object *obj);
 void cache_object_set_status(struct cache_object *obj, int status);
 
 int cache_add(struct cache *c, struct cache_object *obj, int id);
-void cache_update(struct cache *c, struct cache_object *obj, int id, struct nf_conntrack *ct);
-struct cache_object *cache_update_force(struct cache *c, struct nf_conntrack *ct);
+void cache_update(struct cache *c, struct cache_object *obj, int id, void *ptr);
+struct cache_object *cache_update_force(struct cache *c, void *ptr);
 void cache_del(struct cache *c, struct cache_object *obj);
-struct cache_object *cache_find(struct cache *c, struct nf_conntrack *ct, int *pos);
+struct cache_object *cache_find(struct cache *c, void *ptr, int *pos);
 void cache_stats(const struct cache *c, int fd);
 void cache_stats_extended(const struct cache *c, int fd);
 struct cache_object *cache_data_get_object(struct cache *c, void *data);
@@ -120,7 +154,18 @@ void cache_iterate_limit(struct cache *c, void *data, uint32_t from, uint32_t st
 /* iterators */
 struct nfct_handle;
 
+struct __dump_container {
+	int fd;
+	int type;
+};
+
 void cache_dump(struct cache *c, int fd, int type);
+
+struct __commit_container {
+	struct nfct_handle	*h;
+	struct cache		*c;
+};
+
 int cache_commit(struct cache *c, struct nfct_handle *h, int clientfd);
 void cache_flush(struct cache *c);
 void cache_bulk(struct cache *c);
diff --git a/include/internal.h b/include/internal.h
index 1f11340..f50eb79 100644
--- a/include/internal.h
+++ b/include/internal.h
@@ -12,25 +12,28 @@ enum {
 };
 
 struct internal_handler {
-	void	*data;
 	unsigned int flags;
 
 	int	(*init)(void);
 	void	(*close)(void);
 
-	void	(*new)(struct nf_conntrack *ct, int origin_type);
-	void	(*update)(struct nf_conntrack *ct, int origin_type);
-	int	(*destroy)(struct nf_conntrack *ct, int origin_type);
+	struct {
+		void	*data;
 
-	void	(*dump)(int fd, int type);
-	void	(*populate)(struct nf_conntrack *ct);
-	void	(*purge)(void);
-	int	(*resync)(enum nf_conntrack_msg_type type,
-			  struct nf_conntrack *ct, void *data);
-	void	(*flush)(void);
+		void	(*new)(struct nf_conntrack *ct, int origin_type);
+		void	(*upd)(struct nf_conntrack *ct, int origin_type);
+		int	(*del)(struct nf_conntrack *ct, int origin_type);
 
-	void	(*stats)(int fd);
-	void	(*stats_ext)(int fd);
+		void	(*dump)(int fd, int type);
+		void	(*populate)(struct nf_conntrack *ct);
+		void	(*purge)(void);
+		int	(*resync)(enum nf_conntrack_msg_type type,
+				  struct nf_conntrack *ct, void *data);
+		void	(*flush)(void);
+
+		void	(*stats)(int fd);
+		void	(*stats_ext)(int fd);
+	} ct;
 };
 
 extern struct internal_handler internal_cache;