[PATCH 2/4] network: Support bridge mode for zones

[Jonatan Schlag <jonatan.schlag@ipfire.org>]

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This bridge mode is supposed to be used for virtual environments
to create a network zone as a bridge and have virtual machines inside
it. Other physical interfaces can also be added to the bridge.

This is very similar to the MACVTAP bridge feature but still works
when the link of any (or all) physical interfaces is down.

Fixes: #11252

Signed-off-by: Jonatan Schlag <jonatan.schlag(a)ipfire.org>
---
 config/udev/network-hotplug-macvtap | 100 ++++++++++++++++++++++++++++++------
 config/udev/network-hotplug-rename  |   4 ++
 2 files changed, 88 insertions(+), 16 deletions(-)

diff --git a/config/udev/network-hotplug-macvtap b/config/udev/network-hotplug-macvtap
index 7f5da12..ff6d20a 100644
--- a/config/udev/network-hotplug-macvtap
+++ b/config/udev/network-hotplug-macvtap
@@ -23,24 +23,92 @@
 
 [ -n "${INTERFACE}" ] || exit 2
 
-PHYSICAL_INTERFACE="${INTERFACE}"
-VIRTUAL_INTERFACE="${INTERFACE%phys}"
-#VIRTUAL_INTERFACE="${VIRTUAL_INTERFACE}0"
+eval $(/usr/local/bin/readhash /var/ipfire/ethernet/settings)
 
-# Do nothing if the physical interface does not end with "phys"
-case "${PHYSICAL_INTERFACE}" in
-	*phys)
+detect_zone() {
+	local intf="${INTERFACE%0*}"
+	intf="${intf^^}"
+
+	local zone
+	for zone in GREEN BLUE ORANGE RED; do
+		# Try to find if INTERFACE is the *phys version of a zone
+		if [ "${intf}" = "${zone}" ]; then
+			echo "${zone}"
+			return 0
+		fi
+
+		# Try to find out if this INTERFACE is a slave of a zone
+		local slave
+		for slave in $(get_value "${zone}_SLAVES"); do
+			if [ "${INTERFACE}" = "${slave}" ]; then
+				echo "${zone}"
+				return 0
+			fi
+		done
+	done
+
+	return 1
+}
+
+get_value() {
+	echo "${!1}"
+}
+
+random_mac_address() {
+	local address="02"
+
+	for i in $(seq 5); do
+		printf -v address "${address}:%02x" "$(( RANDOM % 256 ))"
+	done
+
+	echo "${address}"
+}
+
+# Try to detect which zone we are operating on
+ZONE=$(detect_zone)
+
+# Cannot proceed if we could not find a zone
+if [ -z "${ZONE}" ]; then
+	exit 0
+fi
+
+# Determine the mode of this zone
+MODE="$(get_value "${ZONE}_MODE")"
+
+# The name of the virtual bridge
+BRIDGE="$(get_value "${ZONE}_DEV")"
+
+case "${MODE}" in
+	bridge)
+		ADDRESS="$(get_value "${ZONE}_MACADDR")"
+		[ -n "${ADDRESS}" ] || ADDRESS="$(random_mac_address)"
+
+		# We need to create the bridge if it doesn't exist, yet
+		if [ ! -d "/sys/class/net/${BRIDGE}" ]; then
+			ip link add "${BRIDGE}" address "${ADDRESS}" type bridge
+			#ip link set "${BRIDGE}" up
+		fi
+
+		# Attach the physical device
+		ip link set dev "${INTERFACE}" master "${BRIDGE}"
+		ip link set dev "${INTERFACE}" up
 		;;
-	*)
-		exit 0
+
+	macvtap)
+		ADDRESS="$(</sys/class/net/${INTERFACE}/address)"
+		GENERATED_ADDRESS=$(random_mac_address)
+
+		ip link add link "${INTERFACE}" "${BRIDGE}" address "${ADDRESS}" type macvlan mode bridge
+		ip link set "${INTERFACE}" address "${GENERATED_ADDRESS}"
+		ip link set "${INTERFACE}" up
 		;;
-esac
 
-ADDRESS="$(</sys/class/net/${PHYSICAL_INTERFACE}/address)"
-rand="$(</proc/sys/kernel/random/uuid)"
-rand="${rand//-/}"
-GENERATED_ADDRESS=$(echo "02:${rand:0:2}:${rand:2:2}:${rand:4:2}:${rand:6:2}:${rand:8:2}")
+	"")
+		exit 0
+		;;
 
-ip link add link "${PHYSICAL_INTERFACE}" "${VIRTUAL_INTERFACE}" address "${ADDRESS}" type macvlan mode bridge
-ip link set "${PHYSICAL_INTERFACE}" address "${GENERATED_ADDRESS}"
-ip link set "${PHYSICAL_INTERFACE}" up
+	*)
+		logger -t "network" "Unhandled mode '${MODE}' for '${ZONE}' (${INTERFACE})"
+		exit 1
+		;;
+esac
diff --git a/config/udev/network-hotplug-rename b/config/udev/network-hotplug-rename
index 1f8d5e1..294bb78 100644
--- a/config/udev/network-hotplug-rename
+++ b/config/udev/network-hotplug-rename
@@ -68,6 +68,10 @@ for zone in ${ZONES}; do
 	# If a matching interface has been found we will
 	# print the name to which udev will rename it.
 	case "${!mode}" in
+		bridge)
+			echo "${!device}phys"
+			;;
+
 		macvtap)
 			# MACVTAP mode doesn't work for WiFi devices
 			if [ -d "/sys/class/net/${INTERFACE}/phy80211" ]; then
-- 
2.7.4