--
-- (C) 2017-20 - ntop.org
--

local json = require "dkjson"

require "xmlSimple"

local discover = {}

discover.debug = false

discover.progress_string = "discovery.progess"

discover.osinfo = {
  [0] = {"Unknown",       ''},
  [1] = {"Linux",         '<i class=\'fab fa-linux fa-lg\'></i>'},
  [2] = {"Windows",       '<i class=\'fab fa-windows fa-lg\'></i>'},
  [3] = {"MacOS",         '<i class=\'fab fa-apple fa-lg\'></i>'},
  [4] = {"iOS",           '<i class=\'fab fa-apple fa-lg\'></i>'},
  [5] = {"Android",       '<i class=\'fab fa-android fa-lg\'></i>'},
  [6] = {"LaserJET",      'LasetJET'},
  [7] = {"AppleAirport",  'Apple Airport'},
  -- NOTE: keep in sync with OperatingSystem in ntop_typedefs.h
}

-- #################################

function discover.getOsName(id)
   local info = discover.osinfo[tonumber(id)]

   if(info) then
    return(info[1])
   end

   return("")
end

-- #################################

function discover.getOsIcon(id)
  local info = discover.osinfo[tonumber(id)]

   if(info) then
    return(info[2] .. " ")
   end

   return("")
end

-- #################################

function discover.getOsAndIcon(id)
  local name = discover.getOsName(id)

  if(isEmptyString(name)) then
    return(id)
  else
    return(discover.getOsIcon(id) .. name)
  end
end

-- #################################

discover.apple_osx_versions = {
   ['4'] = 'Mac OS X 10.0 (Cheetah)',
   ['5'] = 'Mac OS X 10.1 (Puma)',
   ['6'] = 'Mac OS X 10.2 (Jaguar)',
   ['7'] = 'Mac OS X 10.3 (Panther)',
   ['8'] = 'Mac OS X 10.4 (Tiger)',
   ['9'] = 'Mac OS X 10.5 (Leopard)',
   ['10'] = 'Mac OS X 10.6 (Snow Leopard)',
   ['11'] = 'Mac OS X 10.7 (Lion)',
   ['12'] = 'OS X 10.8 (Mountain Lion)',
   ['13'] = 'OS X 10.9 (Mavericks)',
   ['14'] = 'OS X 10.10 (Yosemite)',
   ['15'] = 'OS X 10.11 (El Capitan)',
   ['16'] = 'OS X 10.12 (Sierra)',
   ['17'] = 'OS X 10.13 (High Sierra)',
   ['18'] = 'macOS 10.14 (Mojave)',
   ['19'] = 'macOS 10.15 (Catalina)'
}

discover.apple_products = {
   ['Macmini5,3'] = 'Mac mini "Core i7" 2.0 (Mid-2011/Server)',
   ['Macmini5,2'] = 'Mac mini "Core i7" 2.7 (Mid-2011)',
   ['Macmini5,1'] = 'Mac mini "Core i5" 2.3 (Mid-2011)',
   ['MacPro4,1'] = 'Mac Pro "Eight Core" 2.93 (2009/Nehalem)',
   ['iMac16,2'] = 'iMac "Core i7" 3.3 21.5-Inch (4K, Late 2015)',
   ['iMac16,1'] = 'iMac "Core i5" 1.6 21.5-Inch (Late 2015)',
   ['iMac5,1'] = 'iMac "Core 2 Duo" 2.33 20-Inch',
   ['MacBookPro7,1'] = 'MacBook Pro "Core 2 Duo" 2.66 13" Mid-2010',
   ['MacPro2,1'] = 'Mac Pro "Eight Core" 3.0 (2,1)',
   ['MacBook10,1'] = 'MacBook "Core i7" 1.4 12" (Mid-2017-18)',
   ['Macmini1,1'] = 'Mac mini "Core Duo" 1.83',
   ['iMac12,2'] = 'iMac "Core i7" 3.4 27-Inch (Mid-2011)',
   ['iMac6,1'] = 'iMac "Core 2 Duo" 2.33 24-Inch',
   ['MacBookPro5,1'] = 'MacBook Pro "Core 2 Duo" 2.93 15" (Unibody)',
   ['MacBookPro11,5'] = 'MacBook Pro "Core i7" 2.8 15" Mid-2015 (DG)',
   ['MacBookPro11,4'] = 'MacBook Pro "Core i7" 2.8 15" Mid-2015 (IG)',
   ['MacBookPro11,3'] = 'MacBook Pro "Core i7" 2.8 15" Mid-2014 (DG)',
   ['MacBookPro11,2'] = 'MacBook Pro "Core i7" 2.8 15" Mid-2014 (IG)',
   ['MacBookPro11,1'] = 'MacBook Pro "Core i7" 3.0 13" Mid-2014',
   ['MacBookPro10,2'] = 'MacBook Pro "Core i7" 3.0 13" Early 2013',
   ['MacBookPro10,1'] = 'MacBook Pro "Core i7" 2.8 15" Early 2013',
   ['MacBookPro5,5'] = 'MacBook Pro "Core 2 Duo" 2.53 13" (SD/FW)',
   ['MacBookAir7,1'] = 'MacBook Air "Core i7" 2.2 11" (Early 2015)',
   ['MacBookAir7,2'] = 'MacBook Air "Core i7" 2.2 13" (Early 2015)',
   ['iMac17,1'] = 'iMac "Core i7" 4.0 27-Inch (5K, Late 2015)',
   ['MacBookPro8,1'] = 'MacBook Pro "Core i7" 2.8 13" Late 2011',
   ['MacBookPro8,2'] = 'MacBook Pro "Core i7" 2.5 15" Late 2011',
   ['MacBookPro8,3'] = 'MacBook Pro "Core i7" 2.5 17" Late 2011',
   ['MacBook6,1'] = 'MacBook "Core 2 Duo" 2.26 13" (Uni/Late 09)',
   ['MacBookPro4,1'] = 'MacBook Pro "Core 2 Duo" 2.6 17" (08)',
   ['Macmini4,1'] = 'Mac mini "Core 2 Duo" 2.66 (Server)',
   ['PowerMac10,2'] = 'Mac mini G4/1.5',
   ['PowerMac10,1'] = 'Mac mini G4/1.42',
   ['iMac13,2'] = 'iMac "Core i7" 3.4 27-Inch (Late 2012)',
   ['iMac13,1'] = 'iMac "Core i3" 3.3 21.5-Inch (Early 2013)',
   ['iMac9,1'] = 'iMac "Core 2 Duo" 2.26 20-Inch (Mid-2009)',
   ['Macmini3,1'] = 'Mac mini "Core 2 Duo" 2.53 (Server)',
   ['iMac5,2'] = 'iMac "Core 2 Duo" 1.83 17-Inch (IG)',
   ['MacBook2,1'] = 'MacBook "Core 2 Duo" 2.16 13" (Black)',
   ['MacBook1,1'] = 'MacBook "Core Duo" 2.0 13" (Black)',
   ['iMac14,4'] = 'iMac "Core i5" 1.4 21.5-Inch (Mid-2014)',
   ['iMac14,1'] = 'iMac "Core i5" 2.7 21.5-Inch (Late 2013)',
   ['iMac14,3'] = 'iMac "Core i7" 3.1 21.5-Inch (Late 2013)',
   ['iMac14,2'] = 'iMac "Core i7" 3.5 27-Inch (Late 2013)',
   ['MacBookPro2,2'] = 'MacBook Pro "Core 2 Duo" 2.33 15"',
   ['MacBookAir3,2'] = 'MacBook Air "Core 2 Duo" 2.13 13" (Late 2010)',
   ['MacBookPro13,1'] = 'MacBook Pro "Core i7" 2.4 13" Late 2016',
   ['MacBookPro13,3'] = 'MacBook Pro "Core i7" 2.9 15" Touch/Late 2016',
   ['MacBookPro13,2'] = 'MacBook Pro "Core i7" 3.3 13" Touch/Late 2016',
   ['MacBook9,1'] = 'MacBook "Core m7" 1.3 12" (Early 2016)',
   ['MacBookAir6,1'] = 'MacBook Air "Core i7" 1.7 11" (Early 2014)',
   ['MacBookAir6,2'] = 'MacBook Air "Core i7" 1.7 13" (Early 2014)',
   ['MacBookPro9,1'] = 'MacBook Pro "Core i7" 2.7 15" Mid-2012',
   ['MacBookPro9,2'] = 'MacBook Pro "Core i7" 2.9 13" Mid-2012',
   ['MacBook3,1'] = 'MacBook "Core 2 Duo" 2.2 13" (Black-SR)',
   ['MacPro6,1'] = 'Mac Pro "Twelve Core" 2.7 (Late 2013)',
   ['iMac10,1'] = 'iMac "Core 2 Duo" 3.33 27-Inch (Late 2009)',
   ['MacBookPro1,1'] = 'MacBook Pro "Core Duo" 2.16 15"',
   ['MacBookPro5,3'] = 'MacBook Pro "Core 2 Duo" 3.06 15" (SD)',
   ['MacBookPro5,2'] = 'MacBook Pro "Core 2 Duo" 3.06 17" Mid-2009',
   ['iMac8,1'] = 'iMac "Core 2 Duo" 3.06 24-Inch (Early 2008)',
   ['MacBookPro5,4'] = 'MacBook Pro "Core 2 Duo" 2.53 15" (SD)',
   ['Macmini2,1'] = 'Mac mini "Core 2 Duo" 2.0',
   ['MacBookAir3,1'] = 'MacBook Air "Core 2 Duo" 1.6 11" (Late 2010)',
   ['Macmini6,1'] = 'Mac mini "Core i5" 2.5 (Late 2012)',
   ['MacBookPro1,2'] = 'MacBook Pro "Core Duo" 2.16 17"',
   ['iMac4,1'] = 'iMac "Core Duo" 2.0 20-Inch',
   ['iMac4,2'] = 'iMac "Core Duo" 1.83 17-Inch (IG)',
   ['Macmini7,1'] = 'Mac mini "Core i7" 3.0 (Late 2014)',
   ['MacBookPro2,1'] = 'MacBook Pro "Core 2 Duo" 2.33 17"',
   ['MacBook5,1'] = 'MacBook "Core 2 Duo" 2.4 13" (Unibody)',
   ['MacBook5,2'] = 'MacBook "Core 2 Duo" 2.13 13" (White-09)',
   ['MacBookPro14,2'] = 'MacBook Pro "Core i7" 3.5 13" Touch/Mid-2017-18',
   ['MacBookPro14,3'] = 'MacBook Pro "Core i7" 3.1 15" Touch/Mid-2017-18',
   ['MacPro1,1*'] = 'Mac Pro "Quad Core" 3.0 (Original)',
   ['MacBookPro14,1'] = 'MacBook Pro "Core i7" 2.5 13" Mid-2017-18',
   ['MacBookPro12,1'] = 'MacBook Pro "Core i7" 3.1 13" Early 2015',
   ['MacBook8,1'] = 'MacBook "Core M" 1.3 12" (Early 2015)',
   ['iMac15,1'] = 'iMac "Core i5" 3.3 27-Inch (5K, Mid-2015)',
   ['MacBookAir1,1'] = 'MacBook Air "Core 2 Duo" 1.8 13" (Original)',
   ['MacBookAir2,1'] = 'MacBook Air "Core 2 Duo" 2.13 13" (Mid-09)',
   ['iMac7,1'] = 'iMac "Core 2 Extreme" 2.8 24-Inch (Al)',
   ['MacBookAir5,2'] = 'MacBook Air "Core i7" 2.0 13" (Mid-2012)',
   ['MacBook4,1'] = 'MacBook "Core 2 Duo" 2.4 13" (Black-08)',
   ['MacBookAir5,1'] = 'MacBook Air "Core i7" 2.0 11" (Mid-2012)',
   ['MacBookPro3,1'] = 'MacBook Pro "Core 2 Duo" 2.6 17" (SR)',
   ['iMac11,1'] = 'iMac "Core i7" 2.8 27-Inch (Late 2009)',
   ['iMac11,2'] = 'iMac "Core i5" 3.6 21.5-Inch (Mid-2010)',
   ['iMac11,3'] = 'iMac "Core i7" 2.93 27-Inch (Mid-2010)',
   ['MacBook7,1'] = 'MacBook "Core 2 Duo" 2.4 13" (Mid-2010)',
   ['Macmini6,2'] = 'Mac mini "Core i7" 2.6 (Late 2012/Server)',
   ['MacPro5,1'] = 'Mac Pro "Twelve Core" 3.06 (Server 2012)',
   ['MacBookPro6,2'] = 'MacBook Pro "Core i7" 2.8 15" Mid-2010',
   ['MacBookPro6,1'] = 'MacBook Pro "Core i7" 2.8 17" Mid-2010',
   ['iMac18,1'] = 'iMac "Core i5" 2.3 21.5-Inch (Mid-2017-18)',
   ['iMac18,3'] = 'iMac "Core i7" 4.2 27-Inch (5K, Mid-2017-18)',
   ['iMac18,2'] = 'iMac "Core i7" 3.6 21.5-Inch (4K, Mid-2017-18)',
   ['iMac12,1'] = 'iMac "Core i3" 3.1 21.5-Inch (Late 2011)',
   ['MacBookAir4,2'] = 'MacBook Air "Core i5" 1.6 13" (Edu Only)',
   ['MacBookAir4,1'] = 'MacBook Air "Core i7" 1.8 11" (Mid-2011)',
   ['MacPro3,1'] = 'Mac Pro "Eight Core" 3.2 (2008)',
}

discover.asset_icons = {
   ['unknown']     = '',
   ['printer']     = '<i class="fas fa-print fa-lg devtype-icon" aria-hidden="true"></i>', -- 1
   ['video']       = '<i class="fas fa-video fa-lg devtype-icon" aria-hidden="true"></i>', -- 2
   ['workstation'] = '<i class="fas fa-desktop fa-lg devtype-icon" aria-hidden="true"></i>', -- ... and so on
   ['laptop']      = '<i class="fas fa-laptop fa-lg devtype-icon" aria-hidden="true"></i>',
   ['tablet']      = '<i class="fas fa-tablet fa-lg devtype-icon" aria-hidden="true"></i>',
   ['phone']       = '<i class="fas fa-mobile fa-lg devtype-icon" aria-hidden="true"></i>',
   ['tv']          = '<i class="fas fa-tv fa-lg devtype-icon" aria-hidden="true"></i>',
   ['networking']  = '<i class="fas fa-arrows-alt fa-lg devtype-icon" aria-hidden="true"></i>',
   ['wifi']        = '<i class="fas fa-wifi fa-lg devtype-icon" aria-hidden="true"></i>',
   ['nas']         = '<i class="fas fa-database fa-lg devtype-icon" aria-hidden="true"></i>',
   ['multimedia']  = '<i class="fas fa-music fa-lg devtype-icon" aria-hidden="true"></i>',
   ['iot']         = '<i class="fas fa-thermometer fa-lg devtype-icon" aria-hidden="true"></i>',
   -- IMPORTANT: please keep in sync asset_icons with id2label
}

discover.extra_asset_icons = {
   ['lightbulb']      = '<i class="fas fa-lightbulb fa-lg devtype-icon" aria-hidden="true"></i>',
   ['phone']          = '<i class="fas fa-phone fa-lg devtype-icon" aria-hidden="true"></i>',
   ['health']         = '<i class="fas fa-medkit fa-lg devtype-icon" aria-hidden="true"></i>',
}

local id2label = {
 -- ID      string_id    label					special_purpose_device
   [0]  = { 'unknown', i18n("device_types.unknown") },
   [1]  = { 'printer', i18n("device_types.printer"), 		true },
   [2]  = { 'video', i18n("device_types.video"),		true },
   [3]  = { 'workstation', i18n("device_types.workstation") },
   [4]  = { 'laptop', i18n("device_types.laptop") },
   [5]  = { 'tablet', i18n("device_types.tablet") },
   [6]  = { 'phone', i18n("device_types.phone") },
   [7]  = { 'tv', i18n("device_types.tv"),			true },
   [8]  = { 'networking', i18n("device_types.networking"),	true },
   [9]  = { 'wifi', i18n("device_types.wifi"),			true },
   [10] = { 'nas', i18n("device_types.nas"),			true },
   [11] = { 'multimedia', i18n("device_types.multimedia"),	true },
   [12] = { 'iot', i18n("device_types.iot"),			true },
   -- IMPORTANT: please keep in sync asset_icons with id2label
}

discover.ghost_icon = '<i class="fas fa-ghost fa-lg" aria-hidden="true"></i>'
discover.android_icon = '<i class="fab fa-android fa-lg" aria-hidden="true"></i>'
discover.apple_icon = '<i class="fab fa-apple fa-lg" aria-hidden="true"></i>'
discover.MAX_DISCOVERED_DEVICES = 8192

-- ################################################################################

local discover_progress_key = "ntop.discovery_progress"

function setDiscoveryProgress(progress)
   -- io.write(progress.."\n")
   ntop.setCache(discover_progress_key, progress, 60)
end

function discover.getDiscoveryProgress()
   return(ntop.getCache(discover_progress_key) or "")
end

-- ################################################################################

local function device_label_sort_fn(a, b)
   return asc_insensitive(a[2], b[2])
end

-- ################################################################################

function discover.sortedDeviceTypeLabels()
   return pairsByValues(id2label, device_label_sort_fn)
end

-- ################################################################################

local function getCachedDiscoveryKey(interface_name)
   return "ntopng.cache.ifid_"..getInterfaceId(interface_name)..".device_discovery_status"
end

-- ################################################################################

local function getCachedDiscoveredDevicesKey(interface_name)
   return "ntopng.cache.ifid_"..getInterfaceId(interface_name)..".discovered_devices"
end

-- ################################################################################

function discover.getInterfaceNetworkDiscoveryEnabledKey(ifid)
   return "ntopng.prefs.ifid_"..ifid..".interface_network_discovery"
end

-- ################################################################################

function discover.interfaceNetworkDiscoveryEnabled(ifid)
   -- must be discoverable and must have not been disabled by the interface preferences
   return interface.isDiscoverableInterface()
          and not (ntop.getPref(discover.getInterfaceNetworkDiscoveryEnabledKey(ifid)) == "false")
end

-- ################################################################################

local function getRequestNetworkDiscoveryKey(ifid)
   return "ntopng.cache.ifid_"..ifid..".network_discovery_requested"
end

-- ################################################################################

function discover.requestNetworkDiscovery(ifid)
   ntop.setCache(getRequestNetworkDiscoveryKey(ifid), "true")
end

-- ################################################################################

function discover.clearNetworkDiscovery(ifid)
   ntop.delCache(getRequestNetworkDiscoveryKey(ifid))
end

-- ################################################################################

function discover.networkDiscoveryRequested(ifid)
   return ntop.getCache(getRequestNetworkDiscoveryKey(ifid)) == "true"
end

-- ################################################################################

function isPrinterMDNS(mdns)
   if(mdns == nil) then return false end

   if(discover.debug) then
      tprint(mdns)
      io.write(debug.traceback())
   end

   if((mdns["_printer._tcp.local"] ~= nil)
      or (mdns["_scanner._tcp.local"] ~= nil)
      or (mdns["_pdl-datastream._tcp.local"] ~= nil)
   ) then
      return true
   end

   return false
end

-- ################################################################################

function isNASMDNS(mdns)
   if(mdns == nil) then return false end

   if((mdns["_edcp._udp.local"] ~= nil) or (mdns["_afpovertcp._tcp.local"] ~= nil) or (mdns["_smb._tcp.local"] ~= nil)) then
      if(mdns["_companion-link._tcp.local"] == nil) then
	 return true
      end
   end

   return false
end

-- ################################################################################

function isGHomeMDNS(mdns)
    if(mdns == nil) then return false end

    if(discover.debug) then
      tprint(mdns)
      io.write(debug.traceback())
    end

    if((mdns["_googlecast._tcp.local"] ~= nil)
      or (mdns["_googlezone._tcp.local"] ~= nil)
    ) then
      return true
    end

    return false
end

-- ################################################################################

function discover.printDeviceTypeSelectorOptions(device_type, skip_unknown)
   device_type = tonumber(device_type)

   for typeid, info in discover.sortedDeviceTypeLabels() do
      local devtype = info[1]
      local label = info[2]

      if not skip_unknown or devtype ~= "unknown" then
         print("<option value=\"".. typeid .."\"")
         if(typeid == device_type) then print(" selected") end
         print(">".. label .."</option>")
      end
   end
end

-- ################################################################################

function discover.printDeviceTypeSelector(device_type, field_name)
   print [[<div class="form-group"><select name="]] print(field_name) print[[" class="form-control">\
   <option value="0"></option>]]

   discover.printDeviceTypeSelectorOptions(device_type, true)

   print [[</select></div>]]
end

-- ################################################################################

function discover.devtype2icon(devtype)
   local label = id2label[tonumber(devtype) or 0]

   if(label == nil) then label = 'unknown' else label = label[1] end

   return(discover.asset_icons[label])
end

-- ################################################################################

function discover.isValidDevtype(devtype)
   for k,v in pairs(id2label) do
      if(v[1] == devtype) then return(true) end
   end

   return(false)
end

-- ################################################################################

function discover.devtype2id(devtype)
   for k,v in pairs(id2label) do
      if(v[1] == devtype) then return k end
   end

   return(0) -- unknown
end

-- ################################################################################

function discover.id2devtype(id)
   for k,v in pairs(id2label) do
      if(k == id) then return v[1] end
   end

   return("") -- unknown
end

-- ################################################################################

function discover.devtype2string(devtype)
   devtype = tonumber(devtype)
   for k,v in pairs(id2label) do
      if(k == devtype) then return v[2] end
   end

   return("") -- unknown
end

-- ################################################################################

function discover.isSpecialPurposeDevice(id)
   local v = id2label[id]

   if(v) then
      return(v[3] or false)
   end

   return(false)
end

-- ################################################################################

function discover.getGeneralPurposeDevicesList()
   local rv = {}

   for k, v in pairsByField(id2label, 2, asc) do
      if not v[3] then
	 rv[#rv + 1] = v[2]
      end
   end

   return rv
end

-- ################################################################################

function discover.getSpecialPurposeDevicesList()
      local rv = {}

   for k, v in pairsByField(id2label, 2, asc) do
      if v[3] then
	 rv[#rv + 1] = v[2]
      end
   end

   return rv
end

-- ################################################################################

local function getbaseURL(url)
   local name = url:match( "([^/]+)$" )

   if((name == "") or (name == nil)) then
      return(url)
   else
      return(string.sub(url, 1, string.len(url)-string.len(name)-1))
   end
end

-- ################################################################################

local function probeSSH(ip)
   local ssh_rsp = ntop.tcpProbe(ip, 22, 1)

   if(ssh_rsp ~= nil) then
      local _ssh_rsp = string.gsub(ssh_rsp, "\n", "")
      local elems
      local osvers = nil
      local use_last = false

      -- tprint(_ssh_rsp)

      elems = string.split(_ssh_rsp, ' ')
      if(elems == nil) then
      	 osvers = _ssh_rsp
         use_last = true
      else
         osvers = elems[2]

         if(osvers == nil) then
	    osvers = elems[1]
         end
      end

      -- tprint(osvers)

      if(osvers ~= nil) then
	 local _osvers = string.split(osvers, "-")
	 if(_osvers ~= nil) then
	    local n

	    if(use_last) then
	       n = #_osvers
	    else
	       n = 1
	    end

	    osvers = _osvers[n]

	    -- tprint(_osvers)
	    return(trimSpace(osvers))
	 end
      end
   end

   return(trimSpace(ssh_rsp))
end

local function appendSSHOS(mac, ip)
   local r = probeSSH(ip)

   if((r ~= nil) and (r ~= "")) then
      if(string.contains(r, "Debian")
	    or string.contains(r, "Raspbian")
	    or string.contains(r, "dropbear")
	 or string.contains(r, "Ubuntu")) then
	 interface.setHostOperatingSystem(ip, 1) -- 1 = Linux
      elseif(string.contains(r, "MS")) then
	 interface.setHostOperatingSystem(ip, 2) -- 2 = windows
      end

      return(" ("..r..")")
   else
      return("")
   end
end

-- ################################################################################

local function findDevice(ip, mac, manufacturer, _mdns, ssdp_str, ssdp_entries, names,
			  snmpName, snmpDescr, osx, symName)
   local mdns = { }
   local ssdp = { }
   local str
   local friendlyName = ""

   if(snmpName ~= nil) then
      ntop.setHashCache("ntopng.prefs.snmp_devices", ip,  ntop.getPref("ntopng.prefs.default_snmp_community"))
   end

   if((ssdp_entries ~= nil) and (ssdp_entries.friendlyName ~= nil)) then
      friendlyName = ssdp_entries["friendlyName"]
   end

   if((names == nil) or (names[ip] == nil)) then
      hostname = ""
   else
      hostname = string.lower(names[ip])
   end

   if(manufacturer == nil) then manufacturer = "" else manufacturer = string.lower(manufacturer) end
   if(symName == nil) then symName = "" else symName = string.lower(symName) end

   if(_mdns ~= nil) then
      if(discover.debug) then io.write(mac .. " /" .. manufacturer .. " / ".. _mdns.."\n") end
      local mdns_items = string.split(_mdns, ";")

      if(mdns_items == nil) then
	 mdns[_mdns] = 1
      else
	 for _,v in pairs(mdns_items) do
	    mdns[v] = 1
	 end
      end
   end

   if(ssdp_str ~= nil) then
      if(discover.debug) then  io.write(mac .. " /" .. manufacturer .. " / ".. ssdp_str.."\n") end

      local ssdp_items = string.split(ssdp_str, ";")

      if(ssdp_items == nil) then
	 ssdp[ssdp_str] = 1
      else
	 for _,v in pairs(ssdp_items) do
	    ssdp[v] = 1
	 end
      end
   end

   if(osx ~= nil) then
      -- model=iMac11,3;osxvers=16
      local elems = string.split(osx, ';')

      if((elems == nil) and string.contains(osx, "model=")) then
	 elems = {}
	 table.insert(elems, osx)
      end

      if(elems ~= nil) then
	 local model   = string.split(elems[1], '=')
	 local osxvers = nil

	 if(discover.apple_products[model[2]] ~= nil) then
	    model = discover.apple_products[model[2]]
	    if(model == nil) then model = "" end
	 else
	    model = model[2]
	 end

	 if(elems[2] ~= nil) then
	    local osxvers = string.split(elems[2], '=')
	    if(discover.apple_osx_versions[osxvers[2]] ~= nil) then
	       osxvers = discover.apple_osx_versions[osxvers[2]]
	       if(osxvers == nil) then osxvers = "" end
	    else
	       osxvers = osxvers[2]
	    end
	 end
	 osx = "<br>"..model

	 if(osxvers ~= nil) then osx = osx .."<br>"..osxvers end
      end
   end

   if(mdns["_ssh._tcp.local"] ~= nil) then
      local icon = 'workstation'
      local ret

      if(osx ~= nil) then
	 if(string.contains(osx, "MacBook")) then
	    icon = 'laptop'
	 end
      end

      ret = '</i>'..discover.asset_icons[icon]..' ' .. discover.apple_icon

      if(osx ~= nil) then ret = ret .. osx end
      interface.setHostOperatingSystem(ip, 3) -- 3 = OSX
      if(discover.debug) then io.write(debug.traceback()) end
      return icon, ret, nil
   elseif(mdns["_nvstream_dbd._tcp.local"] ~= nil) then
      interface.setHostOperatingSystem(ip, 2) -- 2 = windows
      if(discover.debug) then io.write(debug.traceback()) end
      return 'workstation', discover.asset_icons['workstation']..' (Windows)', nil
   elseif(isGHomeMDNS(mdns)) then
      -- Google Home
      if(discover.debug) then io.write(debug.traceback()) end
      return 'multimedia', discover.asset_icons['multimedia'], nil
   elseif(mdns["_workstation._tcp.local"] ~= nil) then
      interface.setHostOperatingSystem(ip, 1) -- 1 = Linux
      if(discover.debug) then io.write(debug.traceback()) end
      return 'workstation', discover.asset_icons['workstation']..' (Linux)', nil
   else
      interface.setHostOperatingSystem(ip, 0) -- Unknown
   end

   if(string.contains(friendlyName, "TV")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'tv', discover.asset_icons['tv'], nil
   end

   if((ssdp["urn:upnp-org:serviceId:AVTransport"] ~= nil)
	 or (ssdp["urn:upnp-org:serviceId:RenderingControl"] ~= nil)
	 or (ssdp["urn:upnp-org:serviceId:MusicServices"] ~= nil)
      or (mdns["_airplay._tcp.local"] ~= nil)
   ) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'multimedia', discover.asset_icons['multimedia'], nil
   end

   if(ssdp["_airport._tcp.local"] ~= nil) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'wifi', discover.asset_icons['wifi'], nil
   end

   if(ssdp_entries and ssdp_entries["modelDescription"]) then
      local descr = string.lower(ssdp_entries["modelDescription"])

      if(string.contains(descr, "camera")) then
	 if(discover.debug) then io.write(debug.traceback()) end
	 return 'video', discover.asset_icons['video'], nil
      elseif(string.contains(descr, "router")) then
	 if(discover.debug) then io.write(debug.traceback()) end
	 return 'networking', discover.asset_icons['networking'], nil
      end
   end

   if(discover.debug) then io.write("[manufacturer] "..manufacturer.."\n") end
   if((discover.debug) and (snmpName ~= nil)) then io.write("[snmpName] "..snmpName.."\n") end

   if(string.contains(manufacturer, "oki electric") and (snmpName ~= nil)) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'printer', discover.asset_icons['printer'].. ' ('..snmpName..')', snmpName
   elseif(string.contains(manufacturer, "lexmark")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'printer', discover.asset_icons['printer'], nil
   elseif(string.contains(manufacturer, "hikvision")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'video', discover.asset_icons['video'], nil
   elseif(string.contains(manufacturer, "synology")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'nas', discover.asset_icons['nas'], nil
   elseif(string.contains(manufacturer, "sonos")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'multimedia', discover.asset_icons['multimedia'], nil
   elseif(string.contains(manufacturer, "super micro")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'workstation', discover.asset_icons['workstation']..appendSSHOS(mac, ip), nil
   elseif(string.contains(manufacturer, "quanta computer Inc")) then -- Often Dell DRACK
      if(discover.debug) then io.write(debug.traceback()) end
      return 'workstation', discover.asset_icons['workstation']..appendSSHOS(mac, ip), nil
   elseif(string.contains(manufacturer, "fujitsu technology solutions")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'workstation', discover.asset_icons['workstation']..appendSSHOS(mac, ip), nil
   elseif(string.contains(manufacturer, "asustek computer")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'workstation', discover.asset_icons['laptop'], nil
   elseif(string.contains(manufacturer, "raspberry")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'workstation', discover.asset_icons['workstation']..appendSSHOS(mac, ip), nil
   elseif(string.contains(manufacturer, "juniper networks")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'networking', discover.asset_icons['networking'], nil
   elseif(string.contains(manufacturer, "brocade communications")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'networking', discover.asset_icons['networking'], nil
   elseif(string.contains(manufacturer, "cisco")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'networking', discover.asset_icons['networking'], nil
   elseif(string.contains(manufacturer, "routerboard")
	     or string.contains(manufacturer, "netgear") --
	     or string.contains(manufacturer, "tp-link")
   ) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'networking', discover.asset_icons['networking'], nil
   elseif(string.contains(manufacturer, "3com")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'networking', discover.asset_icons['networking'], nil
   elseif(string.contains(manufacturer, "gigaset")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'phone', discover.extra_asset_icons['phone'], nil
   elseif(string.contains(manufacturer, "palo alto networks")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'networking', discover.asset_icons['networking'], nil
   elseif(string.contains(manufacturer, "liteon technology")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'workstation', discover.asset_icons['workstation']..appendSSHOS(mac, ip), nil
   elseif(string.contains(manufacturer, "realtek")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'workstation', discover.asset_icons['workstation']..appendSSHOS(mac, ip), nil
   elseif(string.contains(manufacturer, 'tp%-link')) then -- % is the escape char in Lua
      if(discover.debug) then io.write(debug.traceback()) end
      return 'wifi', discover.asset_icons['wifi'], nil
   elseif(string.contains(manufacturer, 'broadband')) then -- % is the escape char in Lua
      if(discover.debug) then io.write(debug.traceback()) end
      return 'networking', discover.asset_icons['networking'], nil
   elseif(string.contains(manufacturer, 'nest labs')
	  or string.contains(manufacturer, 'netatmo')) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'iot', discover.asset_icons['iot'], nil
   elseif(string.contains(manufacturer, "samsung electronics")
	     or string.contains(manufacturer, "samsung electro")
	     or string.contains(manufacturer, "htc corporation")
	     or string.contains(manufacturer, "huawei")
	     or (string.contains(manufacturer, "xiaomi communications") or string.starts(mac,"44:D1:96"))
             or string.contains(manufacturer, "oneplus")
	     or string.contains(manufacturer, "mobile communications") -- LG Electronics (Mobile Communications)
   ) then
      if(discover.debug) then io.write(debug.traceback()) end
      interface.setHostOperatingSystem(ip, 5) -- 5 = Android
      return 'phone', discover.asset_icons['phone'].. ' ' ..discover.android_icon, nil
   elseif((string.contains(manufacturer, "hewlett packard")
	      or string.contains(manufacturer, "hon hai"))
      and (snmpName ~= nil)) then
      local _snmpName  = string.lower(snmpName)
      local _snmpDescr

      --io.write("IP "..ip.." has descr (".. _snmpName ..")\n")
      if(snmpDescr == nil) then
	 -- io.write("IP "..ip.." has empty descr (".. _snmpName ..")\n")
	 _snmpDescr = _snmpName
      else
	 _snmpDescr = string.lower(snmpDescr)
      end

      if(string.contains(_snmpDescr, "jet") -- JetDirect, LaserJet, InkJet, DeskJet
	 or string.contains(_snmpDescr, "fax")) then
	 if(discover.debug) then io.write(debug.traceback()) end
	 return 'printer', discover.asset_icons['printer']..' ('..snmpName..')', snmpName
      elseif(string.contains(_snmpDescr, "curve")) then
	 if(discover.debug) then io.write(debug.traceback()) end
	 return 'networking', discover.asset_icons['networking']..' ('..snmpName..')', snmpName
      else
	 -- return 'unknown', snmpName, nil
      end
   elseif(string.contains(manufacturer, "vmware")
	     or string.contains(manufacturer, "qemu")
	     or string.contains(manufacturer, "xen")
	     or string.contains(manufacturer, "parallel")
   ) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'workstation', discover.asset_icons['workstation'].." (VM)", nil
   elseif(string.contains(manufacturer, "xerox")
	     or string.contains(manufacturer, "ricoh")
   ) then
      local l = ""

      if(snmpName ~= nil) then l = ' ('..snmpName..')' end
      if(discover.debug) then io.write(debug.traceback()) end
      return 'printer', discover.asset_icons['printer']..l, snmpName
   elseif(string.contains(manufacturer, "apple")) then
      if(string.contains(hostname, "iphone") or string.contains(symName, "iphone")) then
	 interface.setHostOperatingSystem(ip, 4) -- 4 = iOS
	 if(discover.debug) then io.write(debug.traceback()) end
	 return 'phone', discover.asset_icons['phone']..' ('  .. discover.apple_icon .. ' iPhone)', nil
      elseif(string.contains(hostname, "ipad") or string.contains(symName, "ipad")) then
	 interface.setHostOperatingSystem(ip, 4) -- 4 = iOS
	 if(discover.debug) then io.write(debug.traceback()) end
	 return 'tablet', discover.asset_icons['tablet']..' ('  .. discover.apple_icon .. 'iPad)', nil
      elseif(string.contains(hostname, "ipod") or string.contains(symName, "ipod")) then
	 interface.setHostOperatingSystem(ip, 4) -- 4 = iOS
	 if(discover.debug) then io.write(debug.traceback()) end
	 return 'phone', discover.asset_icons['phone']..' ('  .. discover.apple_icon .. 'iPod)', nil
      else
	 local ret = '</i> '..discover.asset_icons['workstation']..' ' .. discover.apple_icon
	 local what = 'workstation'

	 if(((snmpName ~= nil) and string.contains(snmpName, "capsul"))
	       or string.contains(symName, "capsule") or string.contains(hostname, "capsule")
	    or isNASMDNS(mdns)) then
	    ret = '</i> '..discover.asset_icons['nas'], nil
	    what = 'nas'
	 elseif(string.contains(symName, "book") or string.contains(hostname, "book")) then
	    ret = '</i> '..discover.asset_icons['laptop']..' ' .. discover.apple_icon, nil
	    what = 'laptop'
	 elseif(string.contains(symName, "airport")) then
	    ret = '</i> '..discover.asset_icons['wifi']..' ' .. discover.apple_icon, nil
	    what = 'laptop'
	 end

	 if(snmpName ~= nil) then ret = ret .. " ["..snmpName.."]" end
	 interface.setHostOperatingSystem(ip, 3) -- 3 = OSX
	 if(discover.debug) then io.write(debug.traceback()) end
	 return what, ret, snmpName
      end
   end

   -- Amazon devices
   if(string.contains(mac, "F0:4F:7C") and string.contains(hostname, "kindle-")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'tablet', discover.asset_icons['tablet']..' (Kindle)', "Kindle"
   elseif(string.contains(mac, "40:B4:CD") -- and string.contains(hostname, "amazon-")
   ) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'multimedia', discover.asset_icons['multimedia'], "Alexa" -- Alexa
   end

   -- io.write("==>"..mac .. " /" .. manufacturer .. " / ".. friendlyName.. "/"..discover.extra_asset_icons['lightbulb'] .."\n")

   -- Philips Hue
   if(string.contains(mac, "00:17:88") and string.contains(friendlyName, "hue")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'iot', discover.extra_asset_icons['lightbulb'], nil
   end

   -- Withings (Nokia Health)
   if(string.contains(mac, "00:24:E4")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'iot', discover.extra_asset_icons['health'], nil
   end

   -- Logitech
   if(string.contains(manufacturer, "logitech")) then
      if(string.contains(friendlyName, "Harmony")) then
	 if(discover.debug) then io.write(debug.traceback()) end
	 return 'iot', discover.asset_icons['iot'], nil
      else
	 if(discover.debug) then io.write(debug.traceback()) end
	 return 'multimedia', discover.asset_icons['multimedia'], nil
      end
   end

   if(names["gateway.local"] == ip) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'networking', discover.asset_icons['networking'], nil
   end

   if(string.starts(hostname, "desktop-") or string.starts(symName, "desktop-")) then
      interface.setHostOperatingSystem(ip, 2) -- 2 = windows
      if(discover.debug) then io.write(debug.traceback()) end
      return 'workstation', discover.asset_icons['workstation']..' (Windows)', nil
   elseif(string.contains(hostname, "thinkpad") or string.contains(symName, "thinkpad")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'laptop', discover.asset_icons['laptop'], nil
   elseif(string.contains(hostname, "android") or string.contains(symName, "android")) then
      interface.setHostOperatingSystem(ip, 5) -- 5 = Android
      if(discover.debug) then io.write(debug.traceback()) end
      return 'phone', discover.asset_icons['phone']..' ' ..discover.android_icon, nil
   elseif(string.contains(hostname, "%-NAS") or string.contains(symName, "%-NAS")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'nas', discover.asset_icons['nas'], nil
   end

   if(snmpName ~= nil) then
      if(string.contains(snmpName, "router")
	    or string.contains(snmpName, "switch")
      ) then
	 if(discover.debug) then io.write(debug.traceback()) end
	 return 'networking', discover.asset_icons['networking']..' ('..snmpName..')', snmpName
      elseif(string.contains(snmpName, "air")) then
	 if(discover.debug) then io.write(debug.traceback()) end
	 return 'wifi', discover.asset_icons['wifi']..' ('..snmpName..')', snmpName
      end
   end

   if(snmpName == nil) then
      snmpName = ""
   else
      snmpName = ' ('..snmpName..')'
   end

   if(string.contains(manufacturer, "ubiquiti")) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'networking', discover.asset_icons['networking']..snmpName, nil
   end

   if(isPrinterMDNS(mdns)) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'printer', discover.asset_icons['printer']..snmpName, nil
   end

   if(isNASMDNS(mdns)) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'nas', discover.asset_icons['nas']..snmpName, nil
   end

   if(discover.debug) then
      tprint(ssdp)
      tprint(mdns)
   end

   -- Let's try SSH
   ssh_rsp = probeSSH(ip)

   -- Last resort is HTTP
   http_rsp = ntop.httpGet("http://"..ip, nil, nil, 1)
   if((http_rsp ~= nil) and (http_rsp.HTTP_HEADER ~= nil)) then
      local server = http_rsp.HTTP_HEADER["server"]

      if(server ~= nil) then
	 if(discover.debug) then io.write("[SSH] "..server) end
	 if(string.contains(server, "Ubuntu") or string.contains(server, "Debian") or string.contains(server, "Linux")) then
	    interface.setHostOperatingSystem(ip, 1) -- 1 = Linux
	    if(discover.debug) then io.write(debug.traceback()) end
	    return 'workstation', discover.asset_icons['workstation']..' (Linux)', nil
	 elseif(string.contains(server, "Apache")) then
	    if(discover.debug) then io.write(debug.traceback()) end
	    return 'workstation', discover.asset_icons['workstation']..appendSSHOS(mac, ip), nil
	 elseif(string.contains(server, "GoAhead")) then
	    if(discover.debug) then io.write(debug.traceback()) end
	    return 'workstation', discover.asset_icons['workstation']..appendSSHOS(mac, ip), nil
	 elseif(string.contains(server, "Microsoft")) then
	    if(discover.debug) then io.write(debug.traceback()) end
	    interface.setHostOperatingSystem(ip, 2) -- 2 = windows
	    return 'workstation', discover.asset_icons['workstation']..' (Windows)', nil
	 elseif(string.contains(server, "Virata%-EmWeb") or string.contains(server, "HP%-ChaiSOE") -- Usually LaserJet
		   or string.contains(server, "EWS%-NIC5") -- Xerox
		   or string.contains(server, "RomPager") -- Xerox
		   or string.contains(server, "eHTTP") -- Aruba
		   or string.contains(server, "Web-Server") -- Ricoh
	 ) then
	    if(discover.debug) then io.write(debug.traceback()) end
	    return 'printer', discover.asset_icons['printer'], nil
	 end
      end

      --io.write(ip.."\n")
      --tprint(http_rsp.HTTP_HEADER)
   end

   if(ssh_rsp ~= nil) then
      if(discover.debug) then io.write(debug.traceback()) end
      return 'workstation', discover.asset_icons['workstation']..appendSSHOS(mac, ip), ssh_rsp
   end

   if(discover.debug) then io.write(debug.traceback()) end
   return 'unknown', "", nil
end

-- #############################################################################

local function analyzeSSDP(ssdp)
   local rsp = {}

   for url,host in pairs(ssdp) do
      local hresp = ntop.httpGet(url, "", "", 3 --[[ seconds ]])
      local manufacturer = ""
      local modelDescription = ""
      local modelName = ""
      local icon = ""
      local base_url = getbaseURL(url)
      local services = { }
      local friendlyName = ""

      if(hresp ~= nil) and (hresp["CONTENT"] ~= nil) then
	 local xml = newParser()
	 local r = xml:ParseXmlText(hresp["CONTENT"])

	 if(r.root ~= nil) then
	    if(r.root.device ~= nil) then
	       if(r.root.device.friendlyName ~= nil) then
		  friendlyName = r.root.device.friendlyName:value()
	       end
	       if(r.root.device.modelName ~= nil) then
		  modelName = r.root.device.modelName:value()
	       end
	       if(r.root.device.modelDescription ~= nil) then
		  modelDescription = r.root.device.modelDescription:value()
	       end
	    end
	 end

	 if(r.root ~= nil) then
	    if(r.root.device ~= nil) then
	       if(r.root.device.manufacturer ~= nil) then
		  manufacturer = r.root.device.manufacturer:value()
	       end

	       if(r.root.device.serviceList ~= nil) then
		  local k,v
		  local serviceList = r.root.device.serviceList:children()

		  for k,v in pairs(serviceList) do
		     if(v.serviceId ~= nil) then
			local value = v.serviceId:value()
			if(value ~= nil) then
			   if(discover.debug) then io.write(value.."\n") end

			   table.insert(services, value)
			end
		     end
		  end
	       end

	       if(r.root.device.iconList ~= nil) then
		  local k,v
		  local iconList = r.root.device.iconList:children()
		  local lastwidth = 999

		  for k,v in pairs(iconList) do
		     if((v.mimetype ~= nil) and (v.width ~= nil) and (v.url ~= nil)) then
			local mime = v.mimetype:value()
			local width = tonumber(v.width:value())

			if(width <= lastwidth) then
			   if((mime == "image/jpeg") or (mime == "image/png") or (mime == "image/gif")) then

			      if(string.sub(v.url:value(), 1, 1) == "/") then
				 local slash = string.split(base_url, "/")

				 if(slash ~= nil) then
				    base_url = ""

				    for i,v in pairs(slash) do
				       -- io.write(i.." =>"..v.." ["..base_url.."]\n")
				       if(i < 4) then
					  if(i > 1) then base_url = base_url .. "/" end
					  base_url = base_url .. v
				       end
				    end
				 end
			      end

			      if((string.sub(base_url, -1) ~= "/")
				    and (string.sub(v.url:value(), 1, 1) ~= "/"))
			      then
				 base_url = base_url .. "/"
			      end

			      icon = "<img src="..base_url..v.url:value()..">"
			      -- io.write(icon.."\n")
			      lastwidth = width -- Pick the smallest icon
			   end
			end
		     end
		  end
	       end
	    end
	 end

	 if(discover.debug) then  io.write(hresp["CONTENT"].."\n") end
      end

      if(rsp[host] ~= nil) then
	 rsp[host].url = rsp[host].url .. "<br><A HREF="..url..">"..friendlyName.."</A>"

	 for _,v in ipairs(services) do
	    table.insert(rsp[host].services, v)
	 end
      else
	 rsp[host] = { ["icon"] = icon, ["manufacturer"] = manufacturer, ["url"] = "<A HREF="..url..">"..friendlyName.."</A>",
	    ["services"] = services, ["modelName"] = modelName,
	    ["modelDescription"] = modelDescription, ["friendlyName"] = friendlyName }
      end

      if(discover.debug) then io.write(rsp[host].icon .. " / " ..rsp[host].manufacturer .. " / " ..rsp[host].url .. " / " .. "\n") end
   end

   return rsp
end

-- ################################################################################

local function discoverStatus(code, message)
   return {code = code or '', message = message or ''}

end

-- #############################################################################

local function discoverARP()
   if(discover.debug) then io.write("Starting ARP discovery...\n") end
   local status = discoverStatus("OK")
   local res = {}
   local ghost_macs  = {}
   local ghost_found = false
   local arp_mdns = interface.arpScanHosts() -- List of hosts that reply to ARP
   local now = os.time()
   
   if(discover.debug) then io.write("Completed ARP discovery...\n") end

   if(arp_mdns == nil) then
      status = discoverStatus("ERROR", i18n("discover.err_unable_to_arp_discovery"))
   else
      -- Add the known macs to the list
      local known_macs = interface.getMacsInfo(nil, 999, 0, false, true, nil) or {}

      for _,hmac in pairs(known_macs.macs) do
	 if((hmac["bytes.sent"] > 0)
	       and ((now - hmac["seen.last"])  < 60)
	    and (hmac["location"] == "lan")) then -- Skip silent/wan hosts

	    if(arp_mdns[hmac.mac] == nil) then
	       -- This is a known host that has *NOT* been observed via ARP scan
	       local ips = interface.findHostByMac(hmac.mac) or {}
	       
	       if(discover.debug) then io.write("Missing MAC "..hmac.mac.."\n") end

	       for k,v in pairs(ips) do
		  arp_mdns[hmac.mac] = k
		  ghost_macs[hmac.mac] = k
		  ghost_found = true
	       end
	    end
	 end
      end
   end

   return { status = status, ghost_macs = ghost_macs, ghost_found = ghost_found, arp_mdns = arp_mdns }
end

-- #############################################################################

local function discovery2config(interface_name)
   local cached = ntop.getCache(getCachedDiscoveryKey(interface_name))
   local disc = json.decode(cached)

   if isEmptyString(cached) or not disc then
      return
   end

   disc["devices"] = ntop.lrangeCache(getCachedDiscoveredDevicesKey(interface_name), 0, -1) or {}
   for i=1, #disc["devices"] do
      disc["devices"][i] = json.decode(disc["devices"][i])
   end

   if(disc and false) then
      for _,dev in pairs(disc.devices) do
	 if(dev.device_type.."" ~= "unknown") then
	    --print(dev.mac .. " = " .. dev.device_type .. "\n")
	 end
      end
   end

   return disc
end

-- #############################################################################

function discover.discover2table(interface_name, recache)
   local snmp_community = ntop.getPref("ntopng.prefs.default_snmp_community")

   if isEmptyString(snmp_community) then
      snmp_community = "public"
   end

   interface.select(interface_name)

   local cached = discovery2config(interface_name)

   if recache ~= true then
      if not isEmptyString(cached) then
	 return cached or {status = discoverStatus("ERROR", i18n("discover.error_unable_to_decode_json"))}
      else
	 return {status = discoverStatus("NOCACHE", i18n("discover.error_no_discovery_cached"))}
      end
   end

   setDiscoveryProgress("[0 %]")
   -- ARP
   local arp_d = discoverARP()
   if arp_d["status"]["code"] ~= "OK" then
      return {status = arp_d["status"]}
   end

   setDiscoveryProgress("[10 %]")

   local arp_mdns = arp_d["arp_mdns"] or {}
   local ghost_macs = arp_d["ghost_macs"]
   local ghost_found = arp_d["ghost_found"]

   -- SSDP, MDNS and SNMP
   if(discover.debug) then io.write("Starting SSDP discovery...\n") end
   local ssdp = interface.discoverHosts(3)
   local osx_devices = {}

   for mac,ip in pairsByValues(arp_mdns, asc) do
      if((ip == "0.0.0.0") or (ip == "255.255.255.255")) then
	 -- This does not look like a good IP/MAC combination
      elseif(string.find(mac, ":") ~= nil) then
	 local manufacturer = get_manufacturer_mac(mac)

	 -- This is an ARP entry
	 if(discover.debug) then io.write("Attempting to resolve "..ip.."\n") end
	 local sym = ntop.getResolvedName(ip) -- dummy resolution just to fill-up the cache

	 interface.mdnsQueueNameToResolve(ip)

	 if interface.snmpGetBatch then
	    interface.snmpGetBatch(ip, snmp_community, "1.3.6.1.2.1.1.5.0", 0)

	    if(string.contains(manufacturer, "HP")
	       or string.contains(manufacturer, "Hewlett Packard")
	       or string.contains(manufacturer, "Hon Hai")
	    ) then
	       -- Query printer model
	       interface.snmpGetBatch(ip, snmp_community, "1.3.6.1.2.1.25.3.2.1.3.1", 0)
	    end
	 end
      else
	 local ip_addr = mac
	 local mdns_services = ip

	 if(discover.debug) then io.write("[MDNS Services] '"..ip_addr .. "' = '" ..mdns_services.."'\n") end

	 if(string.contains(mdns_services, '_sftp')) then
	    osx_devices[ip_addr] = 1
	 end

	 ntop.resolveName(ip) -- Force address resolution
      end
   end

   setDiscoveryProgress("[30 %]")

   if(discover.debug) then io.write("Analyzing SSDP...\n") end
   ssdp = analyzeSSDP(ssdp)

   local show_services = false

   setDiscoveryProgress("[40 %]")

   if(discover.debug) then io.write("Collecting MDNS responses\n") end
   local mdns = interface.mdnsReadQueuedResponses()

   if(discover.debug) then
      for ip,rsp in pairsByValues(mdns, asc) do
	 io.write("[MDNS Resolver] "..ip.." = "..rsp.."\n")
      end
   end

   for ip,_ in pairs(osx_devices) do
      if(discover.debug) then io.write("[MDNS OSX] Querying "..ip.. "\n") end
      interface.mdnsQueueAnyQuery(ip, "_sftp-ssh._tcp.local")
   end

   setDiscoveryProgress("[50 %]")

   if(discover.debug) then io.write("Collecting SNMP responses\n") end
   local snmp = {}

   if interface.snmpReadResponses then
      snmp = interface.snmpReadResponses() or {}
   end

   -- Query sysDescr for the hosts that have replied
   for ip,rsp in pairsByValues(snmp , asc) do
      -- io.write("Requesting sysDescr for "..ip.."\n")
      interface.snmpGetBatch(ip, snmp_community, "1.3.6.1.2.1.1.1.0", 0)
   end
   setDiscoveryProgress("[60 %]")

   if(discover.debug) then io.write("Collecting MDNS OSX responses\n") end
   osx_devices = interface.mdnsReadQueuedResponses()
   if(discover.debug) then io.write("Collected MDNS OSX responses\n") end

   if(discover.debug) then
      for a,b in pairs(osx_devices) do
	 io.write("[MDNS OSX] "..a.." / ".. b.. "\n")
      end
   end
   setDiscoveryProgress("[70 %]")

   local snmpSysDescr = {}

   if interface.snmpReadResponses then
      snmpSysDescr = interface.snmpReadResponses()
   end

   if(discover.debug) then
      for ip,rsp in pairsByValues(snmpSysDescr, asc) do
	 io.write("[SNMP Descr] "..ip.." OK\n")
      end
   end

   if(discover.debug) then
      for ip,rsp in pairsByValues(snmp, asc) do
	 io.write("[SNMP] "..ip.." = ["..rsp.."][")
         if(snmpSysDescr[i] ~= nil) then io.write(snmpSysDescr[i]) end
         io.write("]\n")
      end
   end

   setDiscoveryProgress("[80 %]")

   -- Time to pack the results in a table...
   local status = discoverStatus("OK")
   local res = {}
   local too_many_devices_discovered = false

   for mac, ip in pairsByValues(arp_mdns, asc) do
      if((string.find(mac, ":") == nil)
	    or (ip == "0.0.0.0")
	 or (ip == "255.255.255.255")) then
	 goto continue
      end

      local entry = {ip = ip, mac = mac, ghost = false, information = {}}

      local host = interface.getHostInfo(ip, 0) -- no VLAN
      local sym, device_type, device_label
      local manufacturer
      local services = ""
      local symIP = mdns[ip]

      if(host ~= nil) then sym = host["name"] else sym = ntop.getResolvedName(ip) end

      if not isEmptyString(sym) and sym ~= ip then
	 entry["sym"] = sym
      end

      if not isEmptyString(symIP) and symIP ~= ip then
	 entry["symIP"] = symIP
      end

      if not isEmptyString(arp_mdns[ip]) then
	 entry["information"] = table.merge(entry["information"], string.split(arp_mdns[ip], ";"))
      end

      if ssdp[ip] then
	 if ssdp[ip].icon then entry["icon"] = ssdp[ip].icon end
	 if ssdp[ip].modelName then entry["modelName"] = ssdp[ip].modelName end
	 if ssdp[ip].url then entry["url"] = ssdp[ip].url end
	 if ssdp[ip].manufacturer then entry["manufacturer"] = ssdp[ip].manufacturer end
	 if ssdp[ip].services then
	    entry["information"] = table.merge(entry["information"], ssdp[ip].services)
	    for i, name in ipairs(ssdp[ip].services) do services = services .. ";" .. name end
	 end
      end

      if(ghost_macs[mac] ~= nil) then entry["ghost"] = true end

      device_type, device_label, device_info = findDevice(ip, mac, entry["manufacturer"] or get_manufacturer_mac(mac),
                                                          arp_mdns[ip], services, ssdp[ip],
                                                          mdns, snmp[ip], snmpSysDescr[ip],
                                                          osx_devices[ip], sym)

      local mac_info = interface.getMacInfo(mac)

      if isEmptyString(device_label) then
         entry["device_label_noicon"] = device_label

	 if mac_info ~= nil then
	    device_label = discover.devtype2icon(mac_info.devtype)
	 end
      end

      if mac_info ~= nil then
	 entry["os_type"] = mac_info.operatingSystem
      end

      ntop.setMacDeviceType(mac, discover.devtype2id(device_type), false) -- false means don't overwrite if already set to ~= unknown

      entry["device_type"] = device_type
      entry["device_label"] = device_label

      if(device_info ~= nil) then
	 entry["device_info"] = device_info
      end

      if(discover.debug) then
	 io.write("======================\n")
	 tprint(entry)
	 io.write("======================\n")
      end

      res[#res + 1] = entry
      if #res >= discover.MAX_DISCOVERED_DEVICES then
	 too_many_devices_discovered = true
	 break
      end

      ::continue::
   end

   setDiscoveryProgress("")

   -- Cleanup old data
   ntop.delCache(getCachedDiscoveryKey(interface_name))
   ntop.delCache(getCachedDiscoveredDevicesKey(interface_name))

   -- Save the discovery status
   local response = {status = status, ghost_found = ghost_found, discovery_timestamp = os.time(), too_many_devices_discovered = too_many_devices_discovered}
   ntop.setCache(getCachedDiscoveryKey(interface_name), json.encode(response))

   -- Save the actually discovered devices
   local records_cache = getCachedDiscoveredDevicesKey(interface_name)

   -- res is already trimmed at MAX_DISCOVERED_DEVICES, no need to check it
   for i=1, #res do
      ntop.lpushCache(records_cache, json.encode(res[i]))
   end

   return response
end

-- ################################################################################

return discover
