netfilter: nf_tables: allocate handle and delete objects via handle

This patch allows deletion of objects via unique handle which can be
listed via '-a' option.

Signed-off-by: Harsha Sharma <harshasharmaiitr@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/net/netfilter/nf_tables.h

@@ -374,6 +374,7 @@ void nft_unregister_set(struct nft_set_type *type);
  *	@list: table set list node
  *	@bindings: list of set bindings
  * 	@name: name of the set
+ *	@handle: unique handle of the set
  * 	@ktype: key type (numeric type defined by userspace, not used in the kernel)
  * 	@dtype: data type (verdict or numeric type defined by userspace)
  * 	@objtype: object type (see NFT_OBJECT_* definitions)
@@ -396,6 +397,7 @@ struct nft_set {
 	struct list_head		list;
 	struct list_head		bindings;
 	char				*name;
+	u64				handle;
 	u32				ktype;
 	u32				dtype;
 	u32				objtype;
@@ -946,6 +948,7 @@ unsigned int nft_do_chain(struct nft_pktinfo *pkt, void *priv);
  *	@objects: stateful objects in the table
  *	@flowtables: flow tables in the table
  *	@hgenerator: handle generator state
+ *	@handle: table handle
  *	@use: number of chain references to this table
  *	@flags: table flag (see enum nft_table_flags)
  *	@genmask: generation mask
@@ -959,6 +962,7 @@ struct nft_table {
 	struct list_head		objects;
 	struct list_head		flowtables;
 	u64				hgenerator;
+	u64				handle;
 	u32				use;
 	u16				family:6,
 					flags:8,
@@ -983,16 +987,17 @@ int nft_verdict_dump(struct sk_buff *skb, int type,
  *	@name: name of this stateful object
  *	@genmask: generation mask
  *	@use: number of references to this stateful object
- * 	@data: object data, layout depends on type
+ *	@handle: unique object handle
  *	@ops: object operations
- *	@data: pointer to object data
+ * 	@data: object data, layout depends on type
  */
 struct nft_object {
 	struct list_head		list;
 	char				*name;
 	struct nft_table		*table;
 	u32				genmask:2,
 					use:30;
+	u64				handle;
 	/* runtime data below here */
 	const struct nft_object_ops	*ops ____cacheline_aligned;
 	unsigned char			data[]
@@ -1074,6 +1079,7 @@ void nft_unregister_obj(struct nft_object_type *obj_type);
  *	@ops_len: number of hooks in array
  *	@genmask: generation mask
  *	@use: number of references to this flow table
+ * 	@handle: unique object handle
  *	@data: rhashtable and garbage collector
  * 	@ops: array of hooks
  */
@@ -1086,6 +1092,7 @@ struct nft_flowtable {
 	int				ops_len;
 	u32				genmask:2,
 					use:30;
+	u64				handle;
 	/* runtime data below here */
 	struct nf_hook_ops		*ops ____cacheline_aligned;
 	struct nf_flowtable		data;

include/uapi/linux/netfilter/nf_tables.h

@@ -174,6 +174,8 @@ enum nft_table_attributes {
 	NFTA_TABLE_NAME,
 	NFTA_TABLE_FLAGS,
 	NFTA_TABLE_USE,
+	NFTA_TABLE_HANDLE,
+	NFTA_TABLE_PAD,
 	__NFTA_TABLE_MAX
 };
 #define NFTA_TABLE_MAX		(__NFTA_TABLE_MAX - 1)
@@ -317,6 +319,7 @@ enum nft_set_desc_attributes {
  * @NFTA_SET_GC_INTERVAL: garbage collection interval (NLA_U32)
  * @NFTA_SET_USERDATA: user data (NLA_BINARY)
  * @NFTA_SET_OBJ_TYPE: stateful object type (NLA_U32: NFT_OBJECT_*)
+ * @NFTA_SET_HANDLE: set handle (NLA_U64)
  */
 enum nft_set_attributes {
 	NFTA_SET_UNSPEC,
@@ -335,6 +338,7 @@ enum nft_set_attributes {
 	NFTA_SET_USERDATA,
 	NFTA_SET_PAD,
 	NFTA_SET_OBJ_TYPE,
+	NFTA_SET_HANDLE,
 	__NFTA_SET_MAX
 };
 #define NFTA_SET_MAX		(__NFTA_SET_MAX - 1)
@@ -1314,6 +1318,7 @@ enum nft_ct_helper_attributes {
  * @NFTA_OBJ_TYPE: stateful object type (NLA_U32)
  * @NFTA_OBJ_DATA: stateful object data (NLA_NESTED)
  * @NFTA_OBJ_USE: number of references to this expression (NLA_U32)
+ * @NFTA_OBJ_HANDLE: object handle (NLA_U64)
  */
 enum nft_object_attributes {
 	NFTA_OBJ_UNSPEC,
@@ -1322,6 +1327,8 @@ enum nft_object_attributes {
 	NFTA_OBJ_TYPE,
 	NFTA_OBJ_DATA,
 	NFTA_OBJ_USE,
+	NFTA_OBJ_HANDLE,
+	NFTA_OBJ_PAD,
 	__NFTA_OBJ_MAX
 };
 #define NFTA_OBJ_MAX		(__NFTA_OBJ_MAX - 1)
@@ -1333,13 +1340,16 @@ enum nft_object_attributes {
  * @NFTA_FLOWTABLE_NAME: name of this flow table (NLA_STRING)
  * @NFTA_FLOWTABLE_HOOK: netfilter hook configuration(NLA_U32)
  * @NFTA_FLOWTABLE_USE: number of references to this flow table (NLA_U32)
+ * @NFTA_FLOWTABLE_HANDLE: object handle (NLA_U64)
  */
 enum nft_flowtable_attributes {
 	NFTA_FLOWTABLE_UNSPEC,
 	NFTA_FLOWTABLE_TABLE,
 	NFTA_FLOWTABLE_NAME,
 	NFTA_FLOWTABLE_HOOK,
 	NFTA_FLOWTABLE_USE,
+	NFTA_FLOWTABLE_HANDLE,
+	NFTA_FLOWTABLE_PAD,
 	__NFTA_FLOWTABLE_MAX
 };
 #define NFTA_FLOWTABLE_MAX	(__NFTA_FLOWTABLE_MAX - 1)