netfilter: nf_tables: add flow table netlink frontend

This patch introduces a netlink control plane to create, delete and dump
flow tables. Flow tables are identified by name, this name is used from
rules to refer to an specific flow table. Flow tables use the rhashtable
class and a generic garbage collector to remove expired entries.

This also adds the infrastructure to add different flow table types, so
we can add one for each layer 3 protocol family.

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

1 files changed, 53 insertions, 0 deletions

diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index 2efbf9744c2a..591b53bce070 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -92,6 +92,9 @@ enum nft_verdicts {
  * @NFT_MSG_GETOBJ: get a stateful object (enum nft_obj_attributes)
  * @NFT_MSG_DELOBJ: delete a stateful object (enum nft_obj_attributes)
  * @NFT_MSG_GETOBJ_RESET: get and reset a stateful object (enum nft_obj_attributes)
+ * @NFT_MSG_NEWFLOWTABLE: add new flow table (enum nft_flowtable_attributes)
+ * @NFT_MSG_GETFLOWTABLE: get flow table (enum nft_flowtable_attributes)
+ * @NFT_MSG_DELFLOWTABLE: delete flow table (enum nft_flowtable_attributes)
  */
 enum nf_tables_msg_types {
 	NFT_MSG_NEWTABLE,
@@ -116,6 +119,9 @@ enum nf_tables_msg_types {
 	NFT_MSG_GETOBJ,
 	NFT_MSG_DELOBJ,
 	NFT_MSG_GETOBJ_RESET,
+	NFT_MSG_NEWFLOWTABLE,
+	NFT_MSG_GETFLOWTABLE,
+	NFT_MSG_DELFLOWTABLE,
 	NFT_MSG_MAX,
 };
 
@@ -1310,6 +1316,53 @@ enum nft_object_attributes {
 #define NFTA_OBJ_MAX		(__NFTA_OBJ_MAX - 1)
 
 /**
+ * enum nft_flowtable_attributes - nf_tables flow table netlink attributes
+ *
+ * @NFTA_FLOWTABLE_TABLE: name of the table containing the expression (NLA_STRING)
+ * @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)
+ */
+enum nft_flowtable_attributes {
+	NFTA_FLOWTABLE_UNSPEC,
+	NFTA_FLOWTABLE_TABLE,
+	NFTA_FLOWTABLE_NAME,
+	NFTA_FLOWTABLE_HOOK,
+	NFTA_FLOWTABLE_USE,
+	__NFTA_FLOWTABLE_MAX
+};
+#define NFTA_FLOWTABLE_MAX	(__NFTA_FLOWTABLE_MAX - 1)
+
+/**
+ * enum nft_flowtable_hook_attributes - nf_tables flow table hook netlink attributes
+ *
+ * @NFTA_FLOWTABLE_HOOK_NUM: netfilter hook number (NLA_U32)
+ * @NFTA_FLOWTABLE_HOOK_PRIORITY: netfilter hook priority (NLA_U32)
+ * @NFTA_FLOWTABLE_HOOK_DEVS: input devices this flow table is bound to (NLA_NESTED)
+ */
+enum nft_flowtable_hook_attributes {
+	NFTA_FLOWTABLE_HOOK_UNSPEC,
+	NFTA_FLOWTABLE_HOOK_NUM,
+	NFTA_FLOWTABLE_HOOK_PRIORITY,
+	NFTA_FLOWTABLE_HOOK_DEVS,
+	__NFTA_FLOWTABLE_HOOK_MAX
+};
+#define NFTA_FLOWTABLE_HOOK_MAX	(__NFTA_FLOWTABLE_HOOK_MAX - 1)
+
+/**
+ * enum nft_device_attributes - nf_tables device netlink attributes
+ *
+ * @NFTA_DEVICE_NAME: name of this device (NLA_STRING)
+ */
+enum nft_devices_attributes {
+	NFTA_DEVICE_UNSPEC,
+	NFTA_DEVICE_NAME,
+	__NFTA_DEVICE_MAX
+};
+#define NFTA_DEVICE_MAX		(__NFTA_DEVICE_MAX - 1)
+
+
+/**
  * enum nft_trace_attributes - nf_tables trace netlink attributes
  *
  * @NFTA_TRACE_TABLE: name of the table (NLA_STRING)