[PATCH 3/3 nf-next] netfilter: Flow table support for the bridge family

[wenxu@ucloud.cn]

From: wenxu <wenxu@ucloud.cn>

This patch adds the bridge flow table type, that implements the datapath
flow table to forward IPv4 traffic through bridge.

Signed-off-by: wenxu <wenxu@ucloud.cn>
---
 net/bridge/netfilter/Kconfig                |  8 +++++
 net/bridge/netfilter/Makefile               |  1 +
 net/bridge/netfilter/nf_flow_table_bridge.c | 46 +++++++++++++++++++++++++++++
 3 files changed, 55 insertions(+)
 create mode 100644 net/bridge/netfilter/nf_flow_table_bridge.c

diff --git a/net/bridge/netfilter/Kconfig b/net/bridge/netfilter/Kconfig
index f4fb0b9..cba5f71 100644
--- a/net/bridge/netfilter/Kconfig
+++ b/net/bridge/netfilter/Kconfig
@@ -33,6 +33,14 @@ config NF_CONNTRACK_BRIDGE
 
 	  To compile it as a module, choose M here.  If unsure, say N.
 
+config NF_FLOW_TABLE_BRIDGE
+	tristate "Netfilter flow table bridge module"
+	depends on NF_FLOW_TABLE && NF_CONNTRACK_BRIDGE
+	help
+          This option adds the flow table bridge support.
+
+	  To compile it as a module, choose M here.
+
 endif # NF_TABLES_BRIDGE
 
 menuconfig BRIDGE_NF_EBTABLES
diff --git a/net/bridge/netfilter/Makefile b/net/bridge/netfilter/Makefile
index 9d77673..deb81e6 100644
--- a/net/bridge/netfilter/Makefile
+++ b/net/bridge/netfilter/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_NFT_BRIDGE_REJECT)  += nft_reject_bridge.o
 
 # connection tracking
 obj-$(CONFIG_NF_CONNTRACK_BRIDGE) += nf_conntrack_bridge.o
+obj-$(CONFIG_NF_FLOW_TABLE_BRIDGE) += nf_flow_table_bridge.o
 
 # packet logging
 obj-$(CONFIG_NF_LOG_BRIDGE) += nf_log_bridge.o
diff --git a/net/bridge/netfilter/nf_flow_table_bridge.c b/net/bridge/netfilter/nf_flow_table_bridge.c
new file mode 100644
index 0000000..ad3220c
--- /dev/null
+++ b/net/bridge/netfilter/nf_flow_table_bridge.c
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/netfilter.h>
+#include <net/netfilter/nf_flow_table.h>
+#include <net/netfilter/nf_tables.h>
+
+static unsigned int
+nf_flow_offload_bridge_hook(void *priv, struct sk_buff *skb,
+			    const struct nf_hook_state *state)
+{
+	switch (skb->protocol) {
+	case htons(ETH_P_IP):
+		return nf_flow_offload_ip_hook(priv, skb, state);
+	}
+
+	return NF_ACCEPT;
+}
+
+static struct nf_flowtable_type flowtable_bridge = {
+	.family		= NFPROTO_BRIDGE,
+	.init		= nf_flow_table_init,
+	.free		= nf_flow_table_free,
+	.hook		= nf_flow_offload_bridge_hook,
+	.owner		= THIS_MODULE,
+};
+
+static int __init nf_flow_bridge_module_init(void)
+{
+	nft_register_flowtable_type(&flowtable_bridge);
+
+	return 0;
+}
+
+static void __exit nf_flow_bridge_module_exit(void)
+{
+	nft_unregister_flowtable_type(&flowtable_bridge);
+}
+
+module_init(nf_flow_bridge_module_init);
+module_exit(nf_flow_bridge_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("wenxu <wenxu@ucloud.cn>");
+MODULE_ALIAS_NF_FLOWTABLE(AF_BRIDGE);
-- 
1.8.3.1