Add package gluon-radv-filterd

This package drops all incoming router advertisements except for the
default router with the best metric according to B.A.T.M.A.N. advanced.

Note that advertisements originating from the node itself (for example
via gluon-radvd) are not affected.

package/gluon-radv-filterd/Makefile

@@ -0,0 +1,41 @@
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=gluon-radv-filterd
+PKG_VERSION:=1
+PKG_RELEASE:=1
+
+PKG_BUILD_DIR := $(BUILD_DIR)/$(PKG_NAME)
+
+include $(INCLUDE_DIR)/package.mk
+
+define Package/gluon-radv-filterd
+  SECTION:=gluon
+  CATEGORY:=Gluon
+  TITLE:=Filter IPv6 router advertisements
+  DEPENDS:=+gluon-ebtables
+endef
+
+define Package/gluon-radv-filterd/description
+	Gluon community wifi mesh firmware framework: filter IPv6 router advertisements
+endef
+
+define Build/Prepare
+	mkdir -p $(PKG_BUILD_DIR)
+	$(CP) ./src/* $(PKG_BUILD_DIR)/
+endef
+
+define Build/Configure
+endef
+
+define Build/Compile
+	CFLAGS="$(TARGET_CFLAGS)" CPPFLAGS="$(TARGET_CPPFLAGS)" $(MAKE) -C $(PKG_BUILD_DIR) $(TARGET_CONFIGURE_OPTS)
+endef
+
+define Package/gluon-radv-filterd/install
+	$(CP) ./files/* $(1)/
+
+	$(INSTALL_DIR) $(1)/usr/sbin/
+	$(INSTALL_BIN) $(PKG_BUILD_DIR)/gluon-radv-filterd $(1)/usr/sbin/
+endef
+
+$(eval $(call BuildPackage,gluon-radv-filterd))

package/gluon-radv-filterd/README.md

@@ -0,0 +1,17 @@
+gluon-radv-filterd
+==================
+This package drops all incoming router advertisements except for the 
+default router with the best metric according to B.A.T.M.A.N. advanced.
+
+Note that advertisements originating from the node itself (for example
+via gluon-radvd) are not affected and considered at all.
+
+"Local" routers
+---------------
+The package has functionality to assign "local" routers, i.e. those connected
+via cable or WLAN instead of via the mesh (technically: appearing in the
+`transtable_local`), a fake TQ of 512 so that they are always preferred.
+However, if used together with the `gluon-ebtables-filter-ra-dhcp` package,
+these router advertisements are filtered anyway and reach neither the node nor
+any other client. You currently have to disable the package or insert custom
+ebtables rules in order to use local routers.

package/gluon-radv-filterd/files/etc/init.d/gluon-radv-filterd

@@ -0,0 +1,14 @@
+#!/bin/sh /etc/rc.common
+
+USE_PROCD=1
+START=50
+DAEMON=/usr/sbin/gluon-radv-filterd
+
+start_service() {
+    procd_open_instance
+    procd_set_param command $DAEMON -i br-client -c RADV_FILTER
+    procd_set_param respawn ${respawn_threshold:-3600} ${respawn_timeout:-5} ${respawn_retry:-5}
+    procd_set_param netdev br-client
+    procd_set_param stderr 1
+    procd_close_instance
+}

package/gluon-radv-filterd/files/lib/gluon/ebtables/400-radv-filterd

@@ -0,0 +1,3 @@
+chain('RADV_FILTER', 'DROP')
+rule 'FORWARD -p IPv6 -i bat0 --ip6-protocol ipv6-icmp --ip6-icmp-type router-advertisement -j RADV_FILTER'
+rule 'RADV_FILTER -j ACCEPT'

package/gluon-radv-filterd/src/Makefile

@@ -0,0 +1,4 @@
+all: gluon-radv-filterd
+
+gluon-radv-filterd: gluon-radv-filterd.c
+	$(CC) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) -Wall -o $@ $^ $(LDLIBS)