bridger: add bridge forwarding accelerator

This package uses BPF to create a fast path which improves bridging performance
by bypassing the bridge layer. It also supports creating tc offload rules for
hardware that supports it.
Hardware offload support can be used with MT7622 + MT7915 once it is merged

Signed-off-by: Felix Fietkau <nbd@nbd.name>

package/network/services/bridger/Makefile

@@ -0,0 +1,62 @@
+#
+# Copyright (C) 2022 OpenWrt.org
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=bridger
+PKG_SOURCE_PROTO:=git
+PKG_SOURCE_URL=https://github.com/nbd168/bridger
+PKG_SOURCE_DATE:=2022-04-06
+PKG_SOURCE_VERSION:=e8f6814a85b4ea951657e7018c5d77597400f44a
+PKG_MIRROR_HASH:=f917e099a9ab2a55745a7254239efabe695a722d5c448342198cdc847a4a24ac
+
+PKG_LICENSE:=GPL-2.0
+PKG_MAINTAINER:=Felix Fietkau <nbd@nbd.name>
+
+PKG_BUILD_DEPENDS:=bpf-headers
+
+PKG_BUILD_PARALLEL:=1
+
+include $(INCLUDE_DIR)/package.mk
+include $(INCLUDE_DIR)/cmake.mk
+include $(INCLUDE_DIR)/bpf.mk
+include $(INCLUDE_DIR)/nls.mk
+
+define Package/bridger
+  SECTION:=utils
+  CATEGORY:=Base system
+  TITLE:=Bridge forwarding accelerator
+  DEPENDS:=+libbpf +libubox +libubus +libnl-tiny +kmod-sched-core +kmod-sched-flower +kmod-sched-bpf +kmod-sched-act-vlan $(BPF_DEPENDS)
+endef
+
+TARGET_CFLAGS += \
+	-I$(STAGING_DIR)/usr/include/libnl-tiny \
+	-I$(STAGING_DIR)/usr/include
+
+CMAKE_OPTIONS += \
+	-DLIBNL_LIBS=-lnl-tiny
+
+define Build/Compile
+	$(call CompileBPF,$(PKG_BUILD_DIR)/bridger-bpf.c)
+	$(Build/Compile/Default)
+endef
+
+define Package/bridger/install
+	$(INSTALL_DIR) \
+		$(1)/etc/config \
+		$(1)/etc/init.d \
+		$(1)/lib/bpf \
+		$(1)/usr/sbin
+	$(INSTALL_DATA) $(PKG_BUILD_DIR)/bridger-bpf.o $(1)/lib/bpf
+	$(INSTALL_BIN) \
+		$(PKG_INSTALL_DIR)/usr/bin/bridger \
+		$(1)/usr/sbin/
+	$(INSTALL_DATA) ./files/bridger.conf $(1)/etc/config/bridger
+	$(INSTALL_BIN) ./files/bridger.init $(1)/etc/init.d/bridger
+endef
+
+$(eval $(call BuildPackage,bridger))

package/network/services/bridger/files/bridger.conf

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+config defaults
+	# example for blacklisting individual devices or bridges
+	# list blacklist eth0

package/network/services/bridger/files/bridger.init

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+#!/bin/sh /etc/rc.common
+# Copyright (c) 2021 OpenWrt.org
+
+START=19
+
+USE_PROCD=1
+PROG=/usr/sbin/bridger
+
+add_blacklist() {
+	cfg="$1"
+
+	config_get blacklist "$cfg" blacklist
+	for i in $blacklist; do
+		json_add_string "" "$i"
+	done
+}
+
+reload_service() {
+	config_load bridger
+
+	json_init
+	json_add_string name "config"
+	json_add_array devices
+	config_foreach add_blacklist defaults
+	json_close_array
+
+	ubus call bridger set_blacklist "$(json_dump)"
+}
+
+service_triggers() {
+	procd_add_reload_trigger bridger
+}
+
+start_service() {
+	procd_open_instance
+	procd_set_param command "$PROG"
+	procd_set_param respawn
+	procd_close_instance
+}
+
+service_started() {
+	ubus -t 10 wait_for bridger
+	[ $? = 0 ] && reload_service
+}