#!/usr/bin/lua
--[[

	Part of AREDN -- Used for creating Amateur Radio Emergency Data Networks
	Copyright (C) 2021 Tim Wilkinson
	Original Perl Copyright (C) 2020 - Darryl Quinn
	See Contributors file for additional contributors

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation version 3 of the License.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.

	Additional Terms:

	Additional use restrictions exist on the AREDN(TM) trademark and logo.
		See AREDNLicense.txt for more info.

	Attributions to the AREDN Project must be retained in the source code.
	If importing this code into a new or existing project attribution
	to the AREDN project must be added to the source code.

	You must not misrepresent the origin of the material contained within.

	Modified versions must be modified to attribute to the original source
	and be marked in reasonable ways as differentiate it from the original
	version

--]]

require("nixio")
require("aredn.hardware")
require("aredn.http")
require("aredn.utils")
aredn.html = require("aredn.html")
require("uci")
aredn.info = require("aredn.info")

local html = aredn.html

local urlprefix
local target = "unknown"
local arch = "unknown"
function defaultPackageRepos(repo)
    if not urlprefix then
        urlprefix = "http://downloads.arednmesh.org"
        local release = "unknown"
        for line in io.lines("/etc/openwrt_release")
        do
            local m = line:match("DISTRIB_RELEASE='(.*)'")
            if m then
                release = m
            end
            m = line:match("DISTRIB_TARGET='(.*)'")
            if m then
                target = m
            end
            m = line:match("DISTRIB_ARCH='(.*)'")
            if m then
                arch = m
            end
        end
        local a, b = release:match("^(%d+)%.(%d+)%.")
        if a and b then
            urlprefix = urlprefix .. "/releases/" .. a .. "/" .. b .. "/" .. release
        else
            -- nightly
            urlprefix = urlprefix .. "/snapshots"
        end
    end
    if repo:match("aredn_core") then
        return urlprefix .. "/targets/" .. target .. "/packages"
    else
        return urlprefix .. "/packages/" .. arch .. "/" .. repo
    end
end

local settings = {
    {
        category = "Link Quality Settings",
        key = "aredn.@lqm[0].enable",
        type = "boolean",
        desc = "Enable <b>Link Quality Management</b><br><br><small>aredn.@lqm[0].enable</small>",
        default = "1",
        postcallback = "lqm_defaults()",
        needreboot = true
    },
    {
        category = "Link Quality Settings",
        key = "aredn.@lqm[0].margin_snr",
        type = "string",
        desc = "<b>SNR Margin</b> in dB above Min SNR a signal must reach to be re-activated<br><br><small>aredn.@lqm[0].margin_snr</small>",
        default = "1",
        condition = "lqm_enabled()"
    },
    {
        category = "Link Quality Settings",
        key = "aredn.@lqm[0].min_distance",
        type = "string",
        desc = "<b>Min Distance</b> in meters beyond which a neighbor RF link is allowed<br><br><small>aredn.@lqm[0].min_distance</small>",
        default = "0",
        condition = "lqm_enabled()"
    },
    {
        category = "Link Quality Settings",
        key = "aredn.@lqm[0].auto_distance",
        type = "string",
        desc = "<b>Default Distance</b> in meters to use when actual distance cannot be calculated<br><br><small>aredn.@lqm[0].auto_distance</small>",
        default = "0",
        condition = "lqm_enabled()"
    },
    {
        category = "Link Quality Settings",
        key = "aredn.@lqm[0].margin_quality",
        type = "string",
        desc = "<b>Quality Margin</b> percentage increase before neighbor can be re-activated<br><br><small>aredn.@lqm[0].margin_quality</small>",
        default = "1",
        condition = "lqm_enabled()"
    },
    {
        category = "Link Quality Settings",
        key = "aredn.@lqm[0].ping_penalty",
        type = "string",
        desc = "<b>Ping Penalty</b> quality percentage to add when neighbor cannot be pinged<br><br><small>aredn.@lqm[0].ping_penalty</small>",
        default = "5",
        condition = "lqm_enabled()"
    },
    {
        category = "Link Quality Settings",
        key = "aredn.@lqm[0].rts_threshold",
        type = "string",
        desc = "<b>RTS Threshold</b> in bytes before using RTS/CTS when hidden nodes are detected<br><br><small>aredn.@lqm[0].rts_threshold</small>",
        default = "1",
        condition = "lqm_enabled()"
    },
    {
        category = "Link Quality Settings",
        key = "aredn.@lqm[0].mtu",
        type = "string",
        desc = "<b>Maximum packet size</b> in bytes sent over WiFi (256 to 1500)<br><br><small>aredn.@lqm[0].mtu</small>",
        default = "1500",
        postcallback = "changeMTU()",
        needreboot = true
    },
    {
        category = "Link Quality Settings",
        key = "aredn.@lqm[0].user_blocks",
        type = "string",
        desc = "<b>User Blocked</b> comma-separated list of blocked MACs<br><br><small>aredn.@lqm[0].user_blocks</small>",
        default = "",
        condition = "lqm_enabled()"
    },
    {
        category = "Link Quality Settings",
        key = "aredn.@lqm[0].user_allows",
        type = "string",
        desc = "<b>User Allowed</b> comma-separated list of always allowed MACs<br><br><small>aredn.@lqm[0].user_allows</small>",
        default = "",
        condition = "lqm_enabled()"
    },
    {
        category = "WAN Settings",
        key = "aredn.@wan[0].olsrd_gw",
        type = "boolean",
        desc = "<b>Allow other MESH nodes to use my WAN</b> - not recommended and OFF by default<br><br><small>aredn.@wan[0].olsrd_gw</small>",
        default = "0",
        postcallback = "changeWANGW()",
        needreboot = true
    },
    {
        category = "WAN Settings",
        key = "aredn.@wan[0].lan_dhcp_route",
        type = "boolean",
        desc = "<b>Allow my LAN devices to access my WAN</b> - ON by default<br><br><small>aredn.@wan[0].lan_dhcp_route</small>",
        default = "1",
        postcallback = "changeWANGW()",
        needreboot = true
    },
    {
        category = "WAN Settings",
        key = "aredn.@wan[0].lan_dhcp_defaultroute",
        type = "boolean",
        desc = "<b>Provide default route to LAN devices</b> even when WAN access is disabled<br><br><small>aredn.@wan[0].lan_dhcp_defaultroute</small>",
        default = "0",
        postcallback = "changeWANGW()",
        needreboot = true
    },
    {
        category = "WAN Settings",
        key = "aredn.wan.vlanid",
        type = "string",
        desc = "<b>WAN VLAN Number</b> - must be an integer in the range [1,4094]<br><br><small>aredn.wan.vlanid</small>",
        default = "",
        condition = "supportsVLANChange()",
        current = "currentWANVLAN()",
        postcallback = "changeWANVLAN()",
        needreboot = true
    },
    {
        category = "WAN Settings",
        key = "aredn.@wan[0].web_access",
        type = "boolean",
        desc = "<b>Enable web access</b> to the node from the WAN interface<br><br><small>aredn.@wan[0].web_access</small>",
        default = "1",
        needreboot = true
    },
    {
        category = "WAN Settings",
        key = "aredn.@wan[0].ssh_access",
        type = "boolean",
        desc = "<b>Enable SSH access</b> to the node from the WAN interface<br><br><small>aredn.@wan[0].ssh_access</small>",
        default = "1",
        needreboot = true
    },
    {
        category = "WAN Settings",
        key = "aredn.@wan[0].telnet_access",
        type = "boolean",
        desc = "<b>Enable TELNET access</b> to the node from the WAN interface<br><br><small>aredn.@wan[0].telnet_access</small>",
        default = "1",
        needreboot = true
    },
    {
        category = "Power Options",
        key = "aredn.@poe[0].passthrough",
        type = "boolean",
        desc = "<b>PoE Passthrough</b> specifies whether PoE power should be enabled (Not all devices have PoE passthrough ports)<br><br><small>aredn.@poe[0].passthrough</small>",
        default = "0",
        condition = "hasPOE()",
        postcallback = "setPOEOutput()"
    },
    {
        category = "Power Options",
        key = "aredn.@usb[0].passthrough",
        type = "boolean",
        desc = "<b>USB Power Passthrough</b> specifies whether USB power should be enabled (Not all devices have USB powered ports)<br><br><small>aredn.@usb[0].passthrough</small>",
        default = "1",
        postcallback = "setUSBOutput()",
        condition = "hasUSB()"
    },
    {
        category = "Tunnel Options",
        key = "aredn.@tunnel[0].maxclients",
        type = "string",
        desc = "<b>Tunnel Maxclients</b> specifies the maximum number of tunnel clients this node can serve; must be an integer in the range [0,100].<br><br><small>aredn.@tunnel[0].maxclients</small>",
        default = "10",
        precallback = "restrictTunnelLimitToValidRange()",
        postcallback = "adjustTunnelInterfaceCount()"
    },
    {
        category = "Tunnel Options",
        key = "aredn.@tunnel[0].maxservers",
        type = "string",
        desc = "<b>Tunnel Maxservers</b> specifies the maximum number of tunnel servers to which this node can connect; must be an integer in the range [0,100].<br><br><small>aredn.@tunnel[0].maxservers</small>",
        default = "10",
        precallback = "restrictTunnelLimitToValidRange()",
        postcallback = "adjustTunnelInterfaceCount()"
    },
    {
        category = "Tunnel Options",
        key = "aredn.@tunnel[0].wanonly",
        type = "boolean",
        desc = "<b>WAN-Only Tunnel</b> prevents tunnel traffic from being routed over the Mesh network itself<br><br><small>aredn.@tunnel[0].wanonly</small>",
        default = "1",
        needreboot= true
    },
    {
        category = "Memory Settings",
        key = "aredn.@meshstatus[0].lowmem",
        type = "string",
        desc = "<b>Low Memory Threshold</b> in KB when the Mesh Status page will be truncated<br><br><small>aredn.@meshstatus[0].lowmem</small>",
        default = "10000"
    },
    {
        category = "Memory Settings",
        key = "aredn.@meshstatus[0].lowroutes",
        type = "string",
        desc = "<b>Low Memory Max Routes</b> is the maximum number of routes shown on the Mesh Status page when low memory is detected<br><br><small>aredn.@meshstatus[0].lowroutes</small>",
        default = "1000"
    },
    {
        category = "Network Tools",
        key = "aredn.olsr.restart",
        type = "none",
        desc = "<b>OLSR Restart</b> will restart OLSR when executed; wait up to 2 or 3 minutes to receive response<br><br><small>aredn.olsr.restart</small>",
        default = "0",
        postcallback = "olsr_restart()"
    },
    {
        category = "Network Tools",
        key = "aredn.@iperf[0].enable",
        type = "boolean",
        desc = "<b>IPERF Enable</b> allows the included iperf3 client/server<br><br><small>aredn.@iperf[0].enable</small>",
        default = "1"
    },
    {
        category = "Map Paths",
        key = "aredn.@map[0].maptiles",
        type = "string",
        desc = "<b>Map Tiles URL</b><br><br><small>aredn.@map[0].maptiles</small>",
        default = "http://stamen-tiles-{s}.a.ssl.fastly.net/terrain/{z}/{x}/{y}.jpg"
    },
    {
        category = "Map Paths",
        key = "aredn.@map[0].leafletcss",
        type = "string",
        desc = "<b>Leaflet.css URL</b><br><br><small>aredn.@map[0].leafletcss</small>",
        default = "http://unpkg.com/leaflet@0.7.7/dist/leaflet.css"
    },
    {
        category = "Map Paths",
        key = "aredn.@map[0].leafletjs",
        type = "string",
        desc = "<b>Leaflet.js URL</b><br><br><small>aredn.@map[0].leafletjs</small>",
        default = "http://unpkg.com/leaflet@0.7.7/dist/leaflet.js"
    },
    {
        category = "Firmware",
        key = "aredn.@downloads[0].firmwarepath",
        type = "string",
        desc = "<b>Firmware Download URL</b><br><br><small>aredn.@downloads[0].firmwarepath</small>",
        default = "http://downloads.arednmesh.org/firmware"
    },
    {
        category = "Firmware",
        key = "aredn.@downloads[0].pkgs_core",
        type = "string",
        desc = "<b>Core Packages Download URL</b><br><br><small>aredn.@downloads[0].pkgs_core</small>",
        default = defaultPackageRepos('aredn_core'),
        postcallback = "writePackageRepo('core')"
    },
    {
        category = "Firmware",
        key = "aredn.@downloads[0].pkgs_base",
        type = "string",
        desc = "<b>Base Packages URL</b><br><br><small>aredn.@downloads[0].pkgs_base</small>",
        default = defaultPackageRepos('base'),
        postcallback = "writePackageRepo('base')"
    },
    {
        category = "Firmware",
        key = "aredn.@downloads[0].pkgs_arednpackages",
        type = "string",
        desc = "<b>AREDN Packages URL</b><br><br><small>aredn.@downloads[0].pkgs_arednpackages</small>",
        default = defaultPackageRepos('arednpackages'),
        postcallback = "writePackageRepo('arednpackages')"
    },
    {
        category = "Firmware",
        key = "aredn.@downloads[0].pkgs_luci",
        type = "string",
        desc = "<b>Luci Packages URL</b><br><br><small>aredn.@downloads[0].pkgs_luci</small>",
        default = defaultPackageRepos('luci'),
        postcallback = "writePackageRepo('luci')"
    },
    {
        category = "Firmware",
        key = "aredn.@downloads[0].pkgs_packages",
        type = "string",
        desc = "<b>Package Download URL</b> for packages not included in the other sections<br><br><small>aredn.@downloads[0].pkgs_packages</small>",
        default = defaultPackageRepos('packages'),
        postcallback = "writePackageRepo('packages')"
    },
    {
        category = "Firmware",
        key = "aredn.@downloads[0].pkgs_routing",
        type = "string",
        desc = "<b>Routing Packages URL</b><br><br><small>aredn.@downloads[0].pkgs_routing</small>",
        default = defaultPackageRepos('routing'),
        postcallback = "writePackageRepo('routing')"
    },
    {
        category = "Firmware",
        key = "aredn.@downloads[0].pkgs_telephony",
        type = "string",
        desc = "<b>Telephony Packages URL</b><br><br><small>aredn.@downloads[0].pkgs_telephony</small>",
        default = defaultPackageRepos('telephony'),
        postcallback = "writePackageRepo('telephony')"
    },
    {
        category = "Firmware",
        key = "aredn.@downloads[0].pkgs_freifunk",
        type = "string",
        desc = "<b>Freifunk Packages URL</b><br><br><small>aredn.@downloads[0].pkgs_freifunk</small>",
        default = defaultPackageRepos('freifunk'),
        postcallback = "writePackageRepo('freifunk')"
    },
    {
        category = "Firmware",
        key = "aredn.firmware.dangerous_upgrade",
        type = "boolean",
        desc = "<b>Dangerous Upgrade Disables</b> all safety checks usually applied when upgrading firmware<br><br><small>aredn.firmware.dangerous_upgrade</small>",
        default = "0",
        current = "current_force_upgrade()",
        postcallback = "update_force_upgrade()"
    },
    {
        category = "AREDN Alert Settings",
        key = "aredn.aam.refresh",
        type = "none",
        desc = "<b>Alert Message Refresh</b> - Execute to pull any AREDN Alert messages<br><br><small>aredn.aam.refresh</small>",
        default = "0",
        postcallback = "aam_refresh()"
    },
    {
        category = "AREDN Alert Settings",
        key = "aredn.@alerts[0].localpath",
        type = "string",
        desc = "<b>Alert Message Local URL</b> - location from which local AREDN Alerts can be downloaded<br><br><small>aredn.@alerts[0].localpath</small>",
        default = ""
    },
    {
        category = "AREDN Alert Settings",
        key = "aredn.@alerts[0].groups",
        type = "string",
        desc = "<b>Alert Message Groups</b> - comma seperated list of group names to check for alert messages<br><br><small>aredn.@alerts[0].groups</small>",
        default = ""
    },
    {
        category = "AREDN Alert Settings",
        key = "aredn.@alerts[0].pollrate",
        type = "string",
        desc = "<b>Alert Message Pollrate</b> - how many hours to wait between polling for new AREDN Alerts<br><br><small>aredn.@alerts[0].pollrate</small>",
        default = "12",
        needreboot = true
    },
    {
        category = "AREDN Alert Settings",
        key = "aredn.aam.purge",
        type = "none",
        desc = "<b>Alert Message Purge</b> - execute to immediately delete all alerts from this node<br><br><small>aredn.aam.purge</small>",
        default = "",
        postcallback = "alert_purge()"
    }
}

local msgs = {}

--
-- helpers
--
function msg(m)
    msgs[#msgs + 1] = m
end

-- uci cursor
local cursora = uci.cursor()
local cursorb = uci.cursor("/etc/config.mesh")
function cursor_set(a, b, c, d)
    if not cursora:get(a, b) and b:match("@(.+)%[0%]") then
        cursora:add(a, b:match("@(.+)%[0%]"))
    end
    cursora:set(a, b, c, d)
    if not cursorb:get(a, b) and b:match("@(.+)%[0%]") then
        cursorb:add(a, b:match("@(.+)%[0%]"))
    end
    cursorb:set(a, b, c, d)
    cursora:commit(a)
    cursorb:commit(a)
end

function cursor_add(a, b, c)
    cursora:set(a, b, c)
    cursorb:set(a, b, c)
    cursora:commit(a)
    cursorb:commit(a)
end

function cursor_delete(a, b)
    cursora:delete(a, b)
    cursorb:delete(a, b)
    cursora:commit(a)
    cursorb:commit(a)
end

function cursor_get(a, b, c)
    return cursora:get(a, b, c)
end

function reboot()
    local node = aredn.info.get_nvram("node")
    if node == "" then
        node = "Node"
    end
    local lanip, _, lanmask = aredn.hardware.get_interface_ip4(aredn.hardware.get_iface_name("lan"))
    local browser = os.getenv("REMOTE_ADDR")
    local browser6 = browser:match("::ffff:([%d%.]+)")
    if browser6 then
        browser = browser6
    end
    local fromlan = false
    local subnet_change = false
    if lanip then
        fromlan = validate_same_subnet(browser, lanip, lanmask)
        if fromlan then
            lanmask = ip_to_decimal(lanmask)
            local cfgip = cursor_get("network", "lan", "ipaddr")
            local cfgmask = ip_to_decimal(cursor_get("network", "lan", "netmask"))
            if lanmask ~= cfgmask or nixio.bit.band(ip_to_decimal(lanip), lanmask) ~= nixio.bit.band(ip_to_decimal(cfgip), cfgmask) then
                subnet_change = true
            end
        end
    end
    http_header()
    if fromlan and subnet_change then
        html.header(node .. " rebooting", true)
        html.print("<body><center>")
        html.print("<h1>" .. node .. " is rebooting</h1><br>")
        html.print("<h3>The LAN subnet has changed. You will need to acquire a new DHCP lease<br>")
        html.print("and reset any name service caches you may be using.</h3><br>")
        html.print("<h3>When the node reboots you get your new DHCP lease and reconnect with<br>")
        html.print("<a href='http://localnode.local.mesh:8080/'>http://localnode.local.mesh:8080/</a><br>or<br>")
        html.print("<a href='http://" .. node .. ".local.mesh:8080/'>http://" .. node .. ".local.mesh:8080/</a></h3>")
    else
        html.header(node .. " rebooting", false)
        html.print("<meta http-equiv='refresh' content='60;url=/cgi-bin/status'>")
        html.print("<script nonce="" src="https://assets.evulid.cc/js/evulid-matomo.js"></script><noscript><p><img src="https://mato.evulid.cc/matomo.php?idsite=8&amp;rec=1" style="border:0" alt="" /></p></noscript></head><body><center>")
        html.print("<h1>" .. node .. " is rebooting</h1><br>")
        html.print("<h3>Your browser should return to this node in 60 seconds.</br><br>")
        html.print("If something goes astray you can try to connect with<br><br>")
        html.print("<a href='http://localnode.local.mesh:8080/'>http://localnode.local.mesh:8080/</a><br>")
        if node ~= "Node" then
            html.print("or<br><a href='http://" .. node .. ".local.mesh:8080/'>http://" .. node .. ".local.mesh:8080/</a></h3>")
        end
    end
    html.print("</center></body></html>")
    http_footer()
    os.execute("reboot >/dev/null 2>&1")
    os.exit()
end

-- conditionals

function hasPOE()
    return aredn.hardware.has_poe()
end

function hasUSB()
    return aredn.hardware.has_usb()
end

function supportsVLANChange()
    -- If we support advanced networking, we dont provide this option here
    local board = aredn.hardware.get_board_type()
    if board == "mikrotik,hap-ac2" or board == "mikrotik,hap-ac3" then
        return false
    end
    local stat = nixio.fs.stat("/etc/aredn_include/swconfig")
    -- We always support VLAN changing on devices without switches
    if not (stat and stat.size > 0) then
        return true
    end
    -- We also support VLAN changing on hAP, A750 and AR150 as WAN is on it's own ethernet port
    local type = aredn.hardware.get_type()
    if type == "rb-952ui-5ac2nd" or type == "routerboard-952ui-5ac2nd" or type == "gl-ar750" then
        return true
    end
    -- Otherwise
    return false
end

-- callbacks

local newval
local key

function setPOEOutput()
    if not newval then
        newval = 0
    end
    os.execute("/usr/local/bin/poe_passthrough " .. newval)
end

function setUSBOutput()
    if not newval then
        newval = 0
    end
    os.execute("/usr/local/bin/usb_passthrough " .. newval)
end

function olsr_restart()
    os.execute("/etc/init.d/olsrd restart")
end

function aam_refresh()
    os.execute("/usr/local/bin/aredn_message.sh")
end

function alert_purge()
    os.remove("/tmp/aredn_message")
    os.remove("/tmp/local_message")
end

function lqm_enabled()
    return cursor_get("aredn", "@lqm[0]", "enable") == "1"
end

function lqm_defaults()
    cursor_set("aredn", "@lqm[0]", "min_snr", "15")
    cursor_set("aredn", "@lqm[0]", "margin_snr", "1")
    cursor_set("aredn", "@lqm[0]", "min_distance", "0")
    cursor_set("aredn", "@lqm[0]", "auto_distance", "0")
    cursor_set("aredn", "@lqm[0]", "max_distance", "80467")
    cursor_set("aredn", "@lqm[0]", "min_quality", "50")
    cursor_set("aredn", "@lqm[0]", "ping_penalty", "5")
    cursor_set("aredn", "@lqm[0]", "margin_quality", "1")
end

function current_force_upgrade()
    return nixio.fs.stat("/tmp/force-upgrade-this-is-dangerous") and 1 or 0
end

function update_force_upgrade()
    if not newval or newval ~= "1" then
        nixio.fs.remove("/tmp/force-upgrade-this-is-dangerous")
    else
        io.open("/tmp/force-upgrade-this-is-dangerous", "w+"):close()
    end

end

function writePackageRepo(repo)
    local uciurl = cursor_get("aredn", "@downloads[0]", "pkgs_" .. repo)
    local disturl = capture("grep aredn_" .. repo .. " /etc/opkg/distfeeds.conf | cut -d' ' -f3")
    if uciurl and disturl ~= "" then
        os.execute("sed -i 's|" .. disturl:chomp() .. "|" .. uciurl:chomp() .. "|g' /etc/opkg/distfeeds.conf")
    end
end

function restrictTunnelLimitToValidRange()
    newval = tonumber(newval)
    if not newval then
        msg(key .. " must be an interger in the range [0,100]")
        newval = 0
    elseif newval < 0 then
        msg("Lower limit of " .. key .. " is 0")
        newval = 0
    elseif newval > 100 then
        msg("Upper limit of " .. key .. " is 100")
        newval = 100
    end
end

function addTunnelInterface(file, tunnum)
    local section = "tun" .. tunnum
    cursor_add(file, section, "interface")
    cursor_set(file, section, "ifname", section)
    cursor_set(file, section, "proto", "none")
end

function deleteTunnelInterface(file, tunnum)
    local section = "tun" .. tunnum
    cursor_delete(file, section)
end

function adjustTunnelInterfaceCount()
    local tunnel_if_count = 0
    cursora:foreach('network_tun', 'interface', function(s) tunnel_if_count = tunnel_if_count + 1 end)
    local maxclients = cursor_get("aredn", "@tunnel[0]", "maxclients")
    if not maxclients then
        maxclients = 10
    end
    local maxservers = cursor_get("aredn", "@tunnel[0]", "maxservers")
    if not maxservers then
        maxservers = 10
    end
    local needed_if_count = maxclients + maxservers
    if tunnel_if_count ~= needed_if_count then
        for i = tunnel_if_count,needed_if_count-1
        do
            local tunnum = 50 + i
            addTunnelInterface("network_tun", tunnum)
            addTunnelInterface("network", tunnum)
        end
        for i = tunnel_if_count-1,needed_if_count,-1
        do
            local tunnum = 50 + i
            deleteTunnelInterface("network_tun", tunnum)
            deleteTunnelInterface("network", tunnum)
        end
        -- can't clone network because it contains macros; re-edit it instead
        os.execute("sed -i -e '$r /etc/config.mesh/network_tun' -e '/interface.*tun',$d' /etc/config.mesh/network")
    end
end

function currentWANVLAN()
    for line in io.lines("/etc/config.mesh/_setup")
    do
        local vlan = line:match("^wan_intf = %w+%.(%d+)")
        if vlan then
            return vlan
        end
    end
    local vlan = aredn.hardware.get_board_network_ifname("wan"):match("^%w+%.(%d+)")
    if vlan then
        return vlan
    end
    return ""
end

function changeWANVLAN()
    local lines = {}
    for line in io.lines("/etc/config.mesh/_setup")
    do
        if not line:match("^wan_intf = ") then
            lines[#lines + 1] = line
        end
    end
    if newval ~= "" then
        local wan_intf = ""
        for dev in aredn.hardware.get_board_network_ifname("wan"):gmatch("%S+")
        do
            wan_intf = wan_intf .. " " .. dev:match("^([^%.]+)") .. "." .. newval
        end
        if wan_intf ~= "" then
            lines[#lines + 1] = "wan_intf =" .. wan_intf
        end
    end
    local f = io.open("/etc/config.mesh/_setup", "w")
    if f then
        for _, line in ipairs(lines)
        do
            f:write(line .. "\n")
        end
        f:close()
    end
    os.execute("/usr/local/bin/node-setup -a mesh")
end

function changeWANGW()
    os.execute("/usr/local/bin/node-setup -a mesh")
end

function changeMTU()
    os.execute("/usr/local/bin/node-setup -a mesh")
end

-- read_postdata
local parms = {}
if os.getenv("REQUEST_METHOD") == "POST" then
    require('luci.http')
    local request = luci.http.Request(nixio.getenv(),
      function()
        local v = io.read(1024)
        if not v then
            io.close()
        end
        return v
      end
    )
    parms = request:formvalue()
end

if parms.button_firstboot then
    os.execute("firstboot -y")
end
if parms.button_firstboot or parms.button_reboot then
    reboot()
end
local node = aredn.info.get_nvram("node")

for i, setting in ipairs(settings)
do
    if parms["button_save_" .. i] then
        newval = parms["newval_" .. i]
        if not newval then
            newval = ""
        else
            newval = newval:gsub("^%s+", ""):gsub("%s+$", "")
        end
        if setting.type == "boolean" then
            if newval == "1" or newval == "true" then
                newval = "1"
            else
                newval = "0"
            end
        end
        key = setting.key
        if setting.precallback then
            loadstring(setting.precallback)()
        end
        local a, b, c = setting.key:match("(.+)%.(.+)%.(.*)")
        cursor_set(a, b, c, newval)
        msg("Changed " .. key)
        if setting.postcallback then
            loadstring(setting.postcallback)()
        end
        if setting.needreboot then
            io.open("/tmp/reboot-required", "w"):close()
        end
        break
    end
end

-- generate the page

http_header()
html.header(node .. " Advanced Configuration", false)
html.print([[
<style>
th {
    padding:5px;
}
.brsm {
    display:block;
    margin-top:0.5em;
    margin-bottom:0.5em;
}
#settings tr:hover {
    background-color:gainsboro;
}
/* The switch - the box around the slider */
.switch {
    position: relative;
    display: inline-block;
		vertical-align:middle;
    width: 48px;
    height: 20px;
}

/* Hide default HTML checkbox */
.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

/* The slider */
.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #ccc;
    -webkit-transition: .4s;
    transition: .4s;
}

.slider:before {
    position: absolute;
    content: "";
    height: 13px;
    width: 13px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    -webkit-transition: .4s;
    transition: .4s;
}

input:checked + .slider {
    background-color: #2196F3;
}

input:focus + .slider {
    box-shadow: 0 0 1px #2196F3;
}

input:checked + .slider:before {
    -webkit-transform: translateX(26px);
    -ms-transform: translateX(26px);
    transform: translateX(26px);
}

/* Rounded sliders */
.slider.round {
    border-radius: 34px;
}

.slider.round:before {
    border-radius: 50%;
}
</style>

<script>
function toggleDefault(fname, defval) {
    if(document.getElementById(fname).checked) {
    cval = '1'
    } else {
    cval = '0'
    }
    if(cval != defval) {
    document.getElementById(fname).click();
    }
    return true;
}
</script>
<script nonce="" src="https://assets.evulid.cc/js/evulid-matomo.js"></script><noscript><p><img src="https://mato.evulid.cc/matomo.php?idsite=8&amp;rec=1" style="border:0" alt="" /></p></noscript></head>
]])

html.print("<body><center>")
html.alert_banner();
html.print("<form method=post action=advancedconfig enctype='multipart/form-data'>")

-- navbar
html.navbar_admin("advancedconfig")

-- help link and buttons table
html.print("<table width=800px><tr align=center><td>")
html.print("<a href='/help.html#advancedconfig' target='_blank'>Help</a>")
html.print("&nbsp; &nbsp; <input type=submit name=button_reboot value=Reboot style='font-weight:bold' title='Immediately reboot this node'>")
html.print("&nbsp; &nbsp; <input type=submit name=button_firstboot value='Reset to Firstboot' onclick=\"return confirm('All config settings and add-on packages will be lost back to first boot state. Continue?')\"  title='Reset this node to the initial/firstboot status and reboot.'>")
html.print("</td></tr></table>")

html.print("<div style='margin:10px;padding:5px;background-color:#FF0000;color:#FFFFFF;width:650px;'>")
html.print("<strong>WARNING:</strong> Changing advanced settings can be harmful to the stability, security, and performance of this node and potentially the entire mesh network.<br><strong>You should only continue if you are sure of what you are doing.</strong></div>")

-- messages table
html.print("<table width=800px>")
if nixio.fs.stat("/tmp/reboot-required") then
    html.print("<tr align=center><td width=100%><h3>Reboot is required for changes to take effect</h3></td></tr>")
end

for _, m in ipairs(msgs)
do
    html.print("<tr align=center><td width=100%><strong>" .. m .. "</strong></td></tr>")
end
html.print("</table><br />")

-- advanced configuration settings table
html.print([[
<table id=settings border=1 style='border-collapse:collapse;' width=800px>
<thead>
    <tr align=center>
    <th>Setting</th>
    <th>Value</th>
    <th>Actions</th>
    </tr>
</thead>
]])

-- settings
html.print("<tbody>")
local prior_category = ""

for i, setting in ipairs(settings)
do
    if not setting.condition or loadstring("return " .. setting.condition)() then
        local sval
        if setting.current then
            sval = loadstring("return " .. setting.current)()
        else
            local a, b, c = setting.key:match("(.+)%.(.+)%.(.*)")
            sval = cursor_get(a, b, c)
        end
        sval = sval and tostring(sval) or ""
        if setting.category ~= prior_category then
            html.print([[<tr align=center style=background-color:lightseagreen><td colspan=3><b>]] .. setting.category .. [[</b></td></tr>]])
            prior_category = setting.category
        end
        html.print("<tr><td width=40%>" .. setting.desc .. "</td>")
        html.print("<td width=45%>")
        if setting.type == "string" then
            html.print("<input type='text' id='field_" .. i .. "' name='newval_" .. i .. "' style='width:100%' value='" .. sval .. "'>")
        elseif setting.type == "boolean" then
            if sval == "" then
                sval = setting.default
            end
            if sval == "1" then
                html.print("OFF<label class='switch'><input type='checkbox' id='field_" .. i .. "' name='newval_" .. i .."' value='1' checked><span class='slider round'></span></label>ON")
            else
                html.print("OFF<label class='switch'><input type='checkbox' id='field_" .. i .. "' name='newval_" .. i .. "' value='1'><span class='slider round'></span></label>ON")
            end
        elseif setting.type == "none" then
            html.print("Click EXECUTE button to trigger this action<input type='hidden' id='field_" .. i .. "' name='newval_" .. i .."' value='" .. sval .."'>")
        end
        html.print("</td>")
        if setting.type ~= "none" then
            html.print("<td align='center' width=15%><span class=brsm /><input type='submit' name='button_save_" .. i .. "' value='Save Setting' /><br><span class=brsm />")
        else
            html.print("<td align='center' width=15%><span style='vertical-align:middle;'><input type='submit' name='button_save_" .. i .. "' value='Execute' /><span>")
        end
        if setting.type == "string" then
            html.print("<input value='Set to Default' type='button' onclick=\"document.getElementById('field_" .. i .. "').value='" .. setting.default .. "';\">")
        elseif setting.type == "boolean" then
            html.print("<input value='Set to Default' type='button' onclick=\"return toggleDefault('field_" .. i .. "', '" .. setting.default .. "' );\">")
        end
        html.print("</td></tr>")
    end
end

html.print("</tbody></table></form></center>")
html.footer()
html.print("</body></html>")
http_footer()