#!/usr/bin/lua

local network = require("lime.network")
local config = require("lime.config")
local fs = require("nixio.fs")
local libuci = require("uci")
local wireless = require("lime.wireless")
local utils = require("lime.utils")

bmx7 = {}

bmx7.configured = false
bmx7.f = "bmx7"

function bmx7.configure(args)
	if bmx7.configured then return end
	bmx7.configured = true

	local uci = libuci:cursor()
	local ipv4, ipv6 = network.primary_address()

	fs.writefile("/etc/config/"..bmx7.f, "")

	uci:set(bmx7.f, "general", "bmx7")
	uci:set(bmx7.f, "general", "dbgMuteTimeout", "1000000")
	uci:set(bmx7.f, "general", "tunOutTimeout", "100000")
	uci:set(bmx7.f, "general", "configSync", "0")
	uci:set(bmx7.f, "general", "syslog", "0")

	uci:set(bmx7.f, "main", "tunDev")
	uci:set(bmx7.f, "main", "tunDev", "main")
	uci:set(bmx7.f, "main", "tun4Address", ipv4:string())
	uci:set(bmx7.f, "main", "tun6Address", ipv6:string())

	-- If publish own IP enabled, configure tunIn
	local pub_own_ip = config.get_bool("network", "bmx7_publish_ownip", false)
	if (pub_own_ip) then
		uci:set(bmx7.f, "myIP4", "tunIn")
		uci:set(bmx7.f, "myIP4", "tunIn", "myIP4")
		uci:set(bmx7.f, "myIP4", "network", ipv4:host():string()..'/32')
		uci:set(bmx7.f, "myIP6", "tunIn")
		uci:set(bmx7.f, "myIP6", "tunIn", "myIP6")
		uci:set(bmx7.f, "myIP6", "network", ipv6:host():string()..'/128')
	end

	-- Enable bmx7 uci config plugin
	uci:set(bmx7.f, "config", "plugin")
	uci:set(bmx7.f, "config", "plugin", "bmx7_config.so")

	-- Enable JSON plugin to get bmx7 information in json format
	if utils.is_installed("bmx7-json") then
		uci:set(bmx7.f, "json", "plugin")
		uci:set(bmx7.f, "json", "plugin", "bmx7_json.so")
	end

	-- Enable topology plugin to get netjson file
	if utils.is_installed("bmx7-topology") then
		uci:set(bmx7.f, "topology", "plugin")
		uci:set(bmx7.f, "topology", "plugin", "bmx7_topology.so")
	end

	-- Enable iwinfo plugin to get better link bandwidth estimation
	if utils.is_installed("bmx7-iwinfo") then
		uci:set(bmx7.f, "iwinfo", "plugin")
		uci:set(bmx7.f, "iwinfo", "plugin", "bmx7_iwinfo.so")
	end

	-- Enable SMS plugin to enable sharing of small files
	if utils.is_installed("bmx7-sms") then
		uci:set(bmx7.f, "sms", "plugin")
		uci:set(bmx7.f, "sms", "plugin", "bmx7_sms.so")
	end

	-- Enable tun plugin, DISCLAIMER: this must be positioned before table plugin if used.
	uci:set(bmx7.f, "ptun", "plugin")
	uci:set(bmx7.f, "ptun", "plugin", "bmx7_tun.so")

	-- Disable ThrowRules because they are broken in IPv6 with current Linux Kernel
	uci:set(bmx7.f, "ipVersion", "ipVersion")
	uci:set(bmx7.f, "ipVersion", "ipVersion", "6")

	-- Search for networks in 172.16.0.0/12
	uci:set(bmx7.f, "nodes", "tunOut")
	uci:set(bmx7.f, "nodes", "tunOut", "nodes")
	uci:set(bmx7.f, "nodes", "network", "172.16.0.0/12")

	-- Search for networks in 10.0.0.0/8
	uci:set(bmx7.f, "clouds", "tunOut")
	uci:set(bmx7.f, "clouds", "tunOut", "clouds")
	uci:set(bmx7.f, "clouds", "network", "10.0.0.0/8")

	-- Search for internet in the mesh cloud
	uci:set(bmx7.f, "inet4", "tunOut")
	uci:set(bmx7.f, "inet4", "tunOut", "inet4")
	uci:set(bmx7.f, "inet4", "network", "0.0.0.0/0")
	uci:set(bmx7.f, "inet4", "maxPrefixLen", "0")

	-- Search for internet IPv6 gateways in the mesh cloud
	uci:set(bmx7.f, "inet6", "tunOut")
	uci:set(bmx7.f, "inet6", "tunOut", "inet6")
	uci:set(bmx7.f, "inet6", "network", "::/0")
	uci:set(bmx7.f, "inet6", "maxPrefixLen", "0")

	-- Search for other mesh cloud announcements that have public ipv6
	uci:set(bmx7.f, "publicv6", "tunOut")
	uci:set(bmx7.f, "publicv6", "tunOut", "publicv6")
	uci:set(bmx7.f, "publicv6", "network", "2000::/3")
	uci:set(bmx7.f, "publicv6", "maxPrefixLen", "64")

	-- Set prefered GW if defined
	local pref_gw = config.get("network", "bmx7_pref_gw")
	if (pref_gw ~= "none") then
		uci:set(bmx7.f, "inet4p", "tunOut")
		uci:set(bmx7.f, "inet4p", "tunOut", "inet4p")
		uci:set(bmx7.f, "inet4p", "network", "0.0.0.0/0")
		uci:set(bmx7.f, "inet4p", "maxPrefixLen", "0")
		uci:set(bmx7.f, "inet4p", "gwName", pref_gw)
		uci:set(bmx7.f, "inet4p", "rating", "1000")

		uci:set(bmx7.f, "inet6p", "tunOut")
		uci:set(bmx7.f, "inet6p", "tunOut", "inet6p")
		uci:set(bmx7.f, "inet6p", "network", "::/0")
		uci:set(bmx7.f, "inet6p", "maxPrefixLen", "0")
		uci:set(bmx7.f, "inet6p", "gwName", pref_gw)
		uci:set(bmx7.f, "inet6p", "rating", "1000")
	else
		uci:delete(bmx7.f, "inet4p", "tunOut")
		uci:delete(bmx7.f, "inet6p", "tunOut")
	end

	local hasBatadv = false
	local bmxOverBatdv = config.get_bool("network", "bmx7_over_batman")
	local hasLan = false
	for _,protoArgs in pairs(config.get("network", "protocols")) do
		local proto =  utils.split(protoArgs, network.protoParamsSeparator)[1]
		if(proto == "lan") then hasLan = true
		elseif(proto == "batadv") then hasBatadv = true end
	end

	if config.get("network", "bmx7_over_librenet6", false) then
		uci:set("bmx7", "librenet6", "dev")
		uci:set("bmx7", "librenet6", "dev", "librenet6")
	end

	local enablePKI = config.get_bool("network", "bmx7_enable_pki")
	if (enablePKI) then
		uci:set(bmx7.f, "general", "trustedNodesDir", "/etc/bmx7/trustedNodes")
	end

	if(hasLan) then
		uci:set("bmx7", "lm_net_br_lan", "dev")
		uci:set("bmx7", "lm_net_br_lan", "dev", "br-lan")

		if(hasBatadv and not bmxOverBatdv) then
			fs.mkdir("/etc/firewall.lime.d")
			fs.writefile("/etc/firewall.lime.d/20-bmx7-not-over-bat0-ebtables",
			"ebtables -t nat -A POSTROUTING -o bat0 -p ipv6"..
			" --ip6-proto udp --ip6-sport 6270 --ip6-dport 6270 -j DROP\n")
		else
			fs.remove("/etc/firewall.lime.d/20-bmx7-not-over-bat0-ebtables")
		end
	end

	uci:save(bmx7.f)

	if utils.is_installed("firewall") then
		uci:delete("firewall", "bmxtun")

		uci:set("firewall", "bmxtun", "zone")
		uci:set("firewall", "bmxtun", "name", "bmx7tun")
		uci:set("firewall", "bmxtun", "input", "ACCEPT")
		uci:set("firewall", "bmxtun", "output", "ACCEPT")
		uci:set("firewall", "bmxtun", "forward", "ACCEPT")
		uci:set("firewall", "bmxtun", "mtu_fix", "1")
		uci:set("firewall", "bmxtun", "conntrack", "1")
		uci:set("firewall", "bmxtun", "device", "X7+")
		uci:set("firewall", "bmxtun", "family", "ipv4")

		uci:save("firewall")

		fs.remove("/etc/firewall.lime.d/20-bmx7tun-mtu_fix")
	else
		fs.mkdir("/etc/firewall.lime.d")
		fs.writefile(
			"/etc/firewall.lime.d/20-bmx7tun-mtu_fix",
			"\n" ..
			"iptables -t mangle -D FORWARD -o X7+ -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu\n" ..
			"iptables -t mangle -A FORWARD -o X7+ -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu\n"
		)
	end
end

function bmx7.setup_interface(ifname, args)
	if not args["specific"] and
		( ifname:match("^wlan%d+.ap") or ifname:match("^eth%d+") )
	then return end

	vlanId = tonumber(args[2]) or 18
	vlanProto = args[3] or "8021ad"
	nameSuffix = args[4] or "_bmx7"

	local owrtInterfaceName, linux802adIfName, owrtDeviceName = network.createVlanIface(ifname, vlanId, nameSuffix, vlanProto)

	local uci = libuci:cursor()
	local mtu = config.get("network", "bmx7_mtu", "1500")
	uci:set("network", owrtDeviceName, "mtu", mtu)

	-- BEGIN [Workaround issue 38]
	if ifname:match("^wlan%d+") then
		local macAddr = wireless.get_phy_mac("phy"..ifname:match("%d+"))
		local vlanIp = { 169, 254, tonumber(macAddr[5], 16), tonumber(macAddr[6], 16) }
		uci:set("network", owrtInterfaceName, "proto", "static")
		uci:set("network", owrtInterfaceName, "ipaddr", table.concat(vlanIp, "."))
		uci:set("network", owrtInterfaceName, "netmask", "255.255.255.255")
	end
	--- END [Workaround issue 38]

	uci:save("network")

	uci:set(bmx7.f, owrtInterfaceName, "dev")
	uci:set(bmx7.f, owrtInterfaceName, "dev", linux802adIfName)

	if ifname:match("^wlan%d+") then
		local rateMax = config.get("network", "bmx7_wifi_rate_max", "auto")
		if rateMax ~= "auto" then
			uci:set(bmx7.f, owrtInterfaceName, "rateMax", rateMax)
		end
	end

	uci:save(bmx7.f)
end

function bmx7.apply()
	os.execute("killall bmx7 ; sleep 2 ; killall -9 bmx7")
	os.execute(bmx7.f)
end

function bmx7.bgp_conf(templateVarsIPv4, templateVarsIPv6)
	local uci = libuci:cursor()

	-- Enable Routing Table Redistribution plugin
	uci:set(bmx7.f, "table", "plugin")
	uci:set(bmx7.f, "table", "plugin", "bmx7_table.so")

	-- Redistribute proto bird routes
	uci:set(bmx7.f, "fromBird", "redistTable")
	uci:set(bmx7.f, "fromBird", "redistTable", "fromBird")
	uci:set(bmx7.f, "fromBird", "table", "254")
	uci:set(bmx7.f, "fromBird", "bandwidth", "100")
	uci:set(bmx7.f, "fromBird", "proto", "12")

	-- Avoid aggregation as it use lot of CPU with huge number of routes
	uci:set(bmx7.f, "fromBird", "aggregatePrefixLen", "128")

	-- Disable proactive tunnels announcement as it use lot of CPU with
	-- huge number of routes
	uci:set(bmx7.f, "general", "proactiveTunRoutes", "0")

	-- BMX7 security features are at moment not used by LiMe, disable hop
	-- by hop links signature as it consume a lot of CPU expecially in
	-- setups with multiples interfaces  and lot of routes like LiMe
	uci:set(bmx7.f, "general", "linkSignatureLen", "0")

	uci:save(bmx7.f)

	local base_bgp_conf = [[
protocol direct {
	interface "X7*";
}
]]

	return base_bgp_conf
end

return bmx7