fff-babel: Make implementation runtime switchable

Some users might want to prefer one babel implementation over another
for various reasons. Having to compile the firmware from scratch can be
quite tedious in that case.

Instead, make the babel implementation switchable at runtime.

Currently, the implementation has to be switched manually in
/lib/functions/fff/babel, which is not upgrade-safe. Also, the previous
implementation is currently not restored after test-mode, so switching
implementations should not be done with test-mode.

Signed-off-by: Fabian Bläse <fabian@blaese.de>

buildscript

@@ -15,7 +15,7 @@ ROUTINGREV="2baff33918c089fd3744c7192f8ae7a29c47a8d7"
 GLUONREV="12e41d0ff07ec54bbd67a31ab50d12ca04f2238c"
 
 OPENWRT_PKGS="gpioctl-sysfs libugpio fastd haserl micrond mtr bmon"
-ROUTING_PKGS="kmod-batman-adv batctl alfred babeld"
+ROUTING_PKGS="kmod-batman-adv batctl alfred babeld bird2"
 GLUON_PKGS="simple-tc uradvd"
 
 FFF_VARIANTS="node layer3"

src/packages/fff/fff-babel-bird2/Makefile

@@ -0,0 +1,29 @@
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=fff-babel-bird2
+PKG_RELEASE:=1
+
+include $(INCLUDE_DIR)/package.mk
+
+define Package/fff-babel-bird2
+	SECTION:=base
+	CATEGORY:=Freifunk
+	TITLE:=Freifunk-Franken babel-bird2
+	URL:=https://www.freifunk-franken.de
+	DEPENDS:=+bird2 +bird2c
+	PROVIDES:=fff-babel-implementation
+endef
+
+define Package/fff-babel-bird2/description
+	This is the Freifunk Franken Firmware babel-bird2 package.
+endef
+
+define Build/Compile
+	# nothing
+endef
+
+define Package/fff-babel-bird2/install
+	$(CP) ./files/* $(1)/
+endef
+
+$(eval $(call BuildPackage,fff-babel-bird2))

src/packages/fff/fff-babel-bird2/files/etc/bird-babel-include.conf

@@ -0,0 +1 @@
+include "/etc/bird-babel/*.conf";

src/packages/fff/fff-babel-bird2/files/etc/bird-fff.conf

@@ -0,0 +1,117 @@
+# router id is not required for babeld, but necessary for bird startup
+router id 192.0.2.0;
+
+ipv4 table fff4;
+ipv6 sadr table fff6;
+
+protocol device {
+	scan time 15;
+}
+
+# device routes for ipv4 peering address
+protocol direct {
+	ipv4 {
+		table fff4;
+		import filter {
+			if (net ~ 10.50.0.0/16 || net ~ 10.83.0.0/16) && net.len = 32 then {
+				accept;
+			}
+			reject;
+		};
+	};
+}
+
+# device routes on loopback interface
+protocol direct {
+	ipv4 {
+		table fff4;
+		import filter {
+			if net ~ 10.50.0.0/16 || net ~ 10.83.0.0/16 then {
+				accept;
+			}
+			reject;
+		};
+	};
+
+	ipv6 sadr {
+		table fff6;
+		import filter {
+			if net ~ fdff::/64 from ::/0 then {
+				reject;
+			}
+
+			# only import GUA + ULA addresses
+			if net !~ 2000::/3 from ::/0  || net !~ fc00::/7 from ::/0 then {
+				reject;
+			}
+
+			accept;
+		};
+		import keep filtered;
+	};
+
+	interface "lo";
+}
+
+# ipv6 kernel route interface
+protocol kernel {
+	ipv6 sadr {
+		table fff6;
+		import filter {
+			# only import routes from kernel with proto static
+			if krt_source != 4 then {
+				reject;
+			}
+
+			if net ~ fdff::/64 from ::/0 then {
+				reject;
+			}
+
+			accept;
+		};
+		export all;
+		preference 200;
+	};
+	kernel table 10;
+	scan time 15;
+	learn yes;
+}
+
+# ipv4 kernel route interface
+protocol kernel {
+	ipv4 {
+		table fff4;
+		import filter {
+			# only import routes from kernel with proto static
+			if krt_source = 4 then {
+				accept;
+			}
+			reject;
+		};
+		export all;
+		preference 200;
+	};
+	kernel table 10;
+	scan time 15;
+	learn yes;
+}
+
+protocol babel {
+	# required due to static configuration of global router id.
+	# also improves reconnect speed after restart.
+	randomize router id yes;
+
+	ipv4 {
+		table fff4;
+		import all;
+		export all;
+	};
+
+	ipv6 sadr {
+		table fff6;
+		import all;
+		export all;
+	};
+
+	include "/etc/bird-babel-include.conf";
+};

src/packages/fff/fff-babel-bird2/files/etc/uci-defaults/30-disable-bird2

@@ -0,0 +1,3 @@
+/etc/init.d/bird disable
+
+exit 0

src/packages/fff/fff-babel-bird2/files/etc/uci-defaults/60-fff-bird-config

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-3.0-only
+
+mv /etc/bird-fff.conf /etc/bird.conf
+
+exit 0

src/packages/fff/fff-babel-bird2/files/lib/functions/fff/babeldaemon/bird2

@@ -0,0 +1,63 @@
+# SPDX-License-Identifier: GPL-3.0-only
+
+babel_add_interface() {
+	[ "$#" -ne "4" ] && return 1
+
+	local name="$1"
+	local interface="$2"
+	local type="$3"
+	local rxcost="$4"
+
+	mkdir -p /tmp/bird-babel
+	echo "interface \"$interface\" { type $type; rxcost $rxcost; };" > /tmp/bird-babel/$name.conf
+
+	return 0
+}
+
+babel_delete_interface() {
+	[ "$#" -ne "1" ] && return 1
+
+	local name="$1"
+
+	# Removing peers from /etc is not necessary, as all peers are generated into /tmp on every configuration run,
+	# which completely overwrites existing peers in /etc in the apply step.
+	rm -f /tmp/bird-babel/$name.conf
+
+	return 0
+}
+
+babel_add_redistribute_filter() {
+	return 0
+}
+
+babel_remove_custom_redistribute_filters() {
+	return 0
+}
+
+babel_apply() {
+	# error output hidden because apply might be executed without a preceding configure step.
+	if [ -d /tmp/bird-babel ]; then
+		rm -rf /etc/bird-babel
+		mv /tmp/bird-babel /etc/bird-babel
+	fi
+
+	return 0
+}
+
+babel_reload_implementation() {
+	# Change include file path, so bird uses the correct configuration, depending on the configuration state:
+	#  - If test mode is active (and /tmp/bird-babel exists), switch to the temporary (/tmp) configuration to be tested.
+	#  - If new settings are applied or the old settings are restored after an unsuccessful test (and /tmp/bird-babel does not exist),
+	#    switch back to the permanent configuration (/etc).
+	if [ -d /tmp/bird-babel ]; then
+		echo 'include "/tmp/bird-babel/*.conf";' > /etc/bird-babel-include.conf
+	else
+		echo 'include "/etc/bird-babel/*.conf";' > /etc/bird-babel-include.conf
+	fi
+
+	/etc/init.d/bird reload
+}
+
+babel_revert() {
+	rm -r /tmp/bird-babel
+}

src/packages/fff/fff-babel-bird2/files/usr/lib/nodewatcher.d/80-bird2.sh

@@ -0,0 +1,14 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-3.0-only
+
+set -e
+set -o pipefail
+
+neighbours="$(birdc -r show babel neighbors |
+		tail -n +5 |
+		awk '{ printf "<neighbour><ip>%s</ip><outgoing_interface>%s</outgoing_interface><link_cost>%s</link_cost></neighbour>", $1, $2, $3 }'
+	)"
+
+echo -n "<babel_neighbours>$neighbours</babel_neighbours>"
+
+exit 0

src/packages/fff/fff-babel/Makefile

@@ -0,0 +1,28 @@
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=fff-babel
+PKG_RELEASE:=1
+
+include $(INCLUDE_DIR)/package.mk
+
+define Package/fff-babel
+	SECTION:=base
+	CATEGORY:=Freifunk
+	TITLE:=Freifunk-Franken babel
+	URL:=https://www.freifunk-franken.de
+	DEPENDS:=+fff-babel-implementation
+endef
+
+define Package/fff-babel/description
+	This is the Freifunk Franken Firmware babel package.
+endef
+
+define Build/Compile
+	# nothing
+endef
+
+define Package/fff-babel/install
+	$(CP) ./files/* $(1)/
+endef
+
+$(eval $(call BuildPackage,fff-babel))

src/packages/fff/fff-babel/files/etc/layer3.d/40-babel

@@ -26,7 +26,7 @@ configure() {
 		fi
 	}
 
-	config_load babeld
+	config_load network
 	config_foreach remove_babelpeer interface
 
 	#add new peers
@@ -75,14 +75,14 @@ configure() {
 		babel_add_peer6addr "network.$prefixname.ip6addr"
 
 		# add babel interface
-		babel_add_interface "$prefixname" "$iface" "$type" "$rxcost" || { echo "Could not add babeld interface for babelpeer $name"; exit 1; }
+		babel_add_interface "$prefixname" "$iface" "$type" "$rxcost" || { echo "Could not add babel interface for babelpeer $name"; exit 1; }
 	}
 
 	config_load gateway
 	config_foreach add_babelpeer babelpeer
 
 
-	# configure babeld filters for custom ipv6 addresses
+	# configure babel filters for custom ipv6 addresses
 	## remove old filters
 	babel_remove_custom_redistribute_filters
 
@@ -94,10 +94,14 @@ configure() {
 
 apply() {
 	uci commit network
-	uci commit babeld
+	babel_apply
+}
+
+reload() {
+	babel_reload
 }
 
 revert() {
 	uci revert network
-	uci revert babeld
+	babel_revert
 }

src/packages/fff/fff-babel/files/lib/functions/fff/babel

@@ -1,3 +1,7 @@
+
+implementation=babeld
+. /lib/functions/fff/babeldaemon/$implementation
+
 babel_add_iifrules() {
 	[ "$#" -ne "1" ] && return 1
 
@@ -61,61 +65,25 @@ babel_add_peer6addr() {
 	return 0
 }
 
-babel_add_interface() {
-	[ "$#" -ne "4" ] && return 1
+babel_reload() {
+	# switch implementation
+	case $implementation in
+		bird2)
+			/etc/init.d/babeld stop 2>/dev/null
+			/etc/init.d/babeld disable
+			/etc/init.d/bird enable
+			/etc/init.d/bird start
+			;;
+		babeld)
+			/etc/init.d/bird stop 2>/dev/null
+			/etc/init.d/bird disable
+			/etc/init.d/babeld enable
+			/etc/init.d/babeld start
+			;;
+	esac
 
-	local name="$1"
-	local interface="$2"
-	local type="$3"
-	local rxcost="$4"
-
-	uci set babeld.$name=interface
-	uci set babeld.$name.ifname="$interface"
-	uci set babeld.$name.type="$type"
-	uci set babeld.$name.rxcost="$rxcost"
-
-	return 0
-}
-
-babel_delete_interface() {
-	[ "$#" -ne "1" ] && return 1
-
-	local name="$1"
-
-	uci -q del babeld.$name
-
-	return 0
-}
-
-babel_add_redistribute_filter() {
-	[ "$#" -ne "1" ] && return 1
-
-	local prefix="$1"
-
-	config=$(uci add babeld filter)
-	uci set babeld.$config.type='redistribute'
-	uci set babeld.$config.ip="$prefix"
-	uci set babeld.$config.addedbyautoconfig='true'
-
-	return 0
-}
-
-babel_remove_custom_redistribute_filters() {
-	[ "$#" -ne "0" ] && return 1
-
-	remove_filters() {
-		local name="$1"
-
-		# check if filter was added by configuregateway
-		if ! [ "$(uci -q get babeld.$name.addedbyautoconfig)" = 'true' ]; then
-			return
-		fi
-
-		uci -q del babeld.$name
-	}
-
-	config_load babeld
-	config_foreach remove_filters filter
+	# call implementation-specific reload commands
+	babel_reload_implementation
 
 	return 0
 }

src/packages/fff/fff-babeld/Makefile

@@ -11,6 +11,7 @@ define Package/fff-babeld
 	TITLE:=Freifunk-Franken babeld configuration example
 	URL:=http://www.freifunk-franken.de
 	DEPENDS:=+babeld
+	PROVIDES:=fff-babel-implementation
 endef
 
 define Package/fff-babeld/description

src/packages/fff/fff-babeld/files/etc/uci-defaults/30-disable-babeld

@@ -0,0 +1,3 @@
+/etc/init.d/babeld disable
+
+exit 0

src/packages/fff/fff-babeld/files/lib/functions/fff/babeldaemon/babeld

@@ -0,0 +1,72 @@
+# SPDX-License-Identifier: GPL-3.0-only
+
+babel_add_interface() {
+	[ "$#" -ne "4" ] && return 1
+
+	local name="$1"
+	local interface="$2"
+	local type="$3"
+	local rxcost="$4"
+
+	uci set babeld.$name=interface
+	uci set babeld.$name.ifname="$interface"
+	uci set babeld.$name.type="$type"
+	uci set babeld.$name.rxcost="$rxcost"
+
+	return 0
+}
+
+babel_delete_interface() {
+	[ "$#" -ne "1" ] && return 1
+
+	local name="$1"
+
+	uci -q del babeld.$name
+
+	return 0
+}
+
+babel_add_redistribute_filter() {
+	[ "$#" -ne "1" ] && return 1
+
+	local prefix="$1"
+
+	config=$(uci add babeld filter)
+	uci set babeld.$config.type='redistribute'
+	uci set babeld.$config.ip="$prefix"
+	uci set babeld.$config.addedbyautoconfig='true'
+
+	return 0
+}
+
+babel_remove_custom_redistribute_filters() {
+	[ "$#" -ne "0" ] && return 1
+
+	remove_filters() {
+		local name="$1"
+
+		# check if filter was added by configuregateway
+		if ! [ "$(uci -q get babeld.$name.addedbyautoconfig)" = 'true' ]; then
+			return
+		fi
+
+		uci -q del babeld.$name
+	}
+
+	config_load babeld
+	config_foreach remove_filters filter
+
+	return 0
+}
+
+babel_apply() {
+	uci commit babeld
+}
+
+babel_reload_implementation() {
+	return 0
+}
+
+babel_revert() {
+	uci revert babeld
+}

src/packages/fff/fff-layer3/Makefile

@@ -11,7 +11,9 @@ define Package/fff-layer3
 	TITLE:=Freifunk-Franken gateway configuration
 	URL:=https://www.freifunk-franken.de
 	DEPENDS:=+fff-alfred-monitoring-proxy \
+	         +fff-babel \
 	         +fff-babeld \
+	         +fff-babel-bird2 \
 	         +fff-boardname \
 	         +fff-dhcp \
 	         +fff-layer3-config \

src/packages/fff/fff-nodewatcher/files/usr/lib/nodewatcher.d/10-systemdata.sh

@@ -76,6 +76,8 @@ fi
 
 if [ -x /usr/sbin/babeld ]; then
 	SYSTEM_DATA="$SYSTEM_DATA<babel_version>$(/usr/sbin/babeld -V 2>&1)</babel_version>"
+elif [ -x /usr/sbin/bird ]; then
+	SYSTEM_DATA="$SYSTEM_DATA<babel_version>$(/usr/sbin/bird --version 2>&1 | sed "s/BIRD version /bird-/")</babel_version>"
 fi
 
 # example for /etc/openwrt_release:

src/packages/fff/fff-wireguard/Makefile

@@ -14,7 +14,7 @@ define Package/fff-wireguard
 		+kmod-wireguard \
 		+owipcalc \
 		+wireguard-tools \
-		+fff-babeld \
+		+fff-babel \
 		+fff-network
 endef
 

src/packages/fff/fff-wireguard/files/etc/layer3.d/50-wireguard

@@ -30,7 +30,7 @@ configure() {
 		fi
 	}
 
-	config_load babeld
+	config_load network
 	config_foreach remove_wgpeer interface
 
 
@@ -127,7 +127,7 @@ configure() {
 		babel_add_iifrules "$prefixname" || { echo "ERROR: Could not add iif-rules for wgpeer $name"; exit 1; }
 
 		# add babel interface
-		babel_add_interface "$prefixname" "$prefixname" 'wired' "$rxcost" || { echo "ERROR: Could not add babeld interface for wgpeer $name"; exit 1; }
+		babel_add_interface "$prefixname" "$prefixname" 'wired' "$rxcost" || { echo "ERROR: Could not add babel interface for wgpeer $name"; exit 1; }
 	}
 
 	config_load gateway
@@ -136,12 +136,16 @@ configure() {
 
 apply() {
 	uci commit network
-	uci commit babeld
 	uci commit gateway
+	babel_apply
+}
+
+reload() {
+	babel_reload
 }
 
 revert() {
 	uci revert network
-	uci revert babeld
 	uci revert gateway
+	babel_revert
 }