link.lua

local component = require "component"
local event = require "event"

local link = {
  ["Link"] = {},
  ["nextHope"] = {},
  ["callback"] = {},
  ["addLink"] =
  function (self,localAddress, remoteAddress )
    if self.Link[ remoteAddress ] then
      table.insert( self.Link[ remoteAddress ] localAddress )
    else
      self.Link[ remoteAddress ] = { localAddress }
    end
    if self.Link[ localAddress ] then
      table.insert( self.Link[ localAddress ], remoteAddress )
    else
      self.Link[ localAddress ] = { remoteAddress }
    end
  end,
  ["discoverLink"] =
  function( self )
    for address,_ in pairs( component.list("modem",true) ) do
      local modem = component.proxy( address )
      if modem.isWireless() then
        modem.setStrength( 256 )
      end
      for i,v in pairs( self.PORT ) do
        modem.open( v )
      end
      modem.broadcast( self.PORT.discovery_request, "discovery_request", address )
    end
    for address,_ in pairs( component.list("tunnel",true) ) do
      local tunnel = component.proxy( "tunnel" )
      tunnel.send( self.PORT.discovery_request, "discovery_request", address )
    end
  end,
  ["discoverRoute"] =
  function( self )

  end,
  ["addDatagram"] =
  function ( self, name, port, callback )
    if self.port.by_port[ port ] then return false
    self.port.by_port[ port ] = name
    self.callback[ name ] = callback
    return true
  end
  ["listen"] =
  function( self )
    local e = {10,event.pull("modem_message")}
    name = e[1]
    if name ~= "modem_message" then return end
    receiver = e[2]
    sender = e[3]
    port = e[4]
    local isTunnel = component.proxy(receiver).type == "tunnel"

    if isTunnel then
      port = e[6]
    end

    args = {table.unpack( e, 6 )}
    if isTunnel then args = {table.unpack( e, 7 )}

    local validDatagram = false

    for i,v in pairs( self.port.by_Port ) do
      if i == port and args[1] == v then
        validDatagram = true
        break
      end
    end

    if not validDatagram then return end

    self.callback[ args[1] ]( table.unpack( args, 2 ) )

    if port == self.PORT["link_discovery_request"] then
      if args[1] ~= "link_discovery_request" or sender ~= args[2] then return end
      self:addLink( receiver, sender )
      component.invoke( receiver ,"send", sender, self.PORT.discovery_response, "link_discovery_response", receiver )
      return
    end
    if port == self.PORT["link_discovery_response"] then
      if args[1] ~= "link_discovery_response" or sender ~= args[2] then return end
      self:addLink( receiver, sender )
      return
    end
  end,
  ["send"] =
  function( self, addr, port, ... )
    local next_hope = self.NextHope[ addr ] or addr
    local interface = Link[ next_hope ]
  end,
  ["port"] =
  {
    ["by_Name"] =
    {
      ["link_discovery_request"] = 25652,
      ["link_discovery_response"] = 65256
    },
    ["by_Port"] = {}

  }
}

return link