external-protocol: rename and update cni-protocol

cni-protocol can be used for both cni and netavark
and also for many other things, such as vpn's that
lack customized protocol supports for openwrt as a
general externally managed protocol, so it was due
to rename it.

I also added one extra option, search domain, which
is optional and updated scripts retrieving ip address
and routing information.

Signed-off-by: Oskari Rauta <oskari.rauta@gmail.com>
(cherry picked from commit a0d7e40494)

net/external-protocol/files/external.sh

@@ -0,0 +1,141 @@
+#!/bin/sh
+
+[ -n "$INCLUDE_ONLY" ] || {
+	. /lib/functions.sh
+	. ../netifd-proto.sh
+	init_proto "$@"
+}
+
+proto_external_init_config() {
+	no_device=0
+	available=0
+
+	proto_config_add_string "device:device"
+	proto_config_add_string "searchdomain"
+	proto_config_add_int "delay"
+}
+
+proto_external_setup() {
+	local cfg="$1"
+	local iface="$2"
+	local device searchdomain delay
+
+	json_get_vars device searchdomain delay
+
+	[ -n "$device" ] || {
+		echo "External protocol interface is not specified"
+		proto_notify_error "$cfg" NO_DEVICE
+		proto_set_available "$cfg" 0
+		return 1
+	}
+
+	[ -n "$delay" ] && sleep "$delay"
+
+	[ -L "/sys/class/net/${iface}" ] || {
+		echo "External protocol interface $iface is not present"
+		proto_notify_error "$cfg" NO_DEVICE
+		proto_set_available "$cfg" 0
+		return 1
+	}
+
+	IP4ADDRS=
+	IP6ADDRS=
+
+	local addresses="$(ip -json address list dev "$iface")"
+	json_init
+	json_load "{\"addresses\":${addresses}}"
+
+	if json_is_a addresses array; then
+		json_select addresses
+		json_select 1
+
+		if json_is_a addr_info array; then
+			json_select addr_info
+
+			local i=1
+			while json_is_a ${i} object; do
+				json_select ${i}
+				json_get_vars scope family local prefixlen broadcast
+
+				if [ "${scope}" == "global" ]; then
+					case "${family}" in
+						inet)
+							append IP4ADDRS "$local/$prefixlen/$broadcast/"
+							;;
+
+						inet6)
+							append IP6ADDRS "$local/$prefixlen/$broadcast///"
+							;;
+					esac
+				fi
+
+				json_select ..
+				i=$(( i + 1 ))
+			done
+		fi
+	fi
+
+	IP4ROUTES=
+	IP6ROUTES=
+
+	local routes="$(ip -json route list dev "$iface")"
+	json_init
+	json_load "{\"routes\":${routes}}"
+
+	if json_is_a routes array;then
+		json_select routes
+
+		local i=1
+		while json_is_a ${i} object; do
+			json_select ${i}
+			json_get_vars dst gateway metric prefsrc
+
+			case "${dst}" in
+				*:*/*)
+					append IP6ROUTES "$dst/$gateway/$metric///$prefsrc"
+					;;
+				*.*/*)
+					append IP4ROUTES "$dst/$gateway/$metric///$prefsrc"
+					;;
+				*:*)
+					append IP6ROUTES "$dst/128/$gateway/$metric///$prefsrc"
+					;;
+				*.*)
+					append IP4ROUTES "$dst/32/$gateway/$metric///$prefsrc"
+					;;
+			esac
+
+			json_select ..
+			i=$(( i + 1 ))
+		done
+	fi
+
+	[ -z "${IP4ADDRS}" -a -z "${IP6ADDRS}" ] && {
+		echo "interface $iface does not have ip address"
+		proto_notify_error "$cfg" NO_IPADDRESS
+		return 1
+	}
+
+	proto_init_update "$iface" 1
+
+	PROTO_IPADDR="${IP4ADDRS}"
+	PROTO_IP6ADDR="${IP6ADDRS}"
+
+	PROTO_ROUTE="${IP4ROUTES}"
+	PROTO_ROUTE6="${IP6ROUTES}"
+
+	[ -n "$searchdomain" ] && proto_add_dns_search "$searchdomain"
+
+	echo "$iface is up"
+
+	proto_send_update "$cfg"
+}
+
+proto_external_teardown() {
+	local cfg="$1"
+	return 0
+}
+
+[ -n "$INCLUDE_ONLY" ] || {
+	add_protocol external
+}