ocvn/lib/net.lua

local async = require("async")
local computer = require("computer")
local component = require("component")
local coroutine = require("coroutine")
local dns = require("dns")
local serial = require("serialization")
local table = require("table")
local string = require("string")
local ll = require("liblua")
local modem = component.proxy(component.list("modem")())

local args = {...}

-- Take some existing modem functions and data
local net = {
  addr = modem.address,
  type = modem.type,
  open = modem.open,
  isOpen = modem.isOpen,
  close = modem.close,
  isWireless = modem.isWireless,
  maxPacketSize = modem.maxPacketSize,
}

-- Used to determine if a string is a proper uuid
function isUUID(s)
  local pattern = {8,4,4,4,12}
  local t = ll.split(s, "-")
  for i, v in ipairs(t) do
    if #v ~= pattern[i] or tonumber(v, 16) == nil then
      return false
    end
  end
  return true
end

-- Resolve addresses if they aren't UUIDs
function checkAddr(addr)
  if not isUUID(addr) then
    return dns.query(addr)
  end
  return addr
end

-- Close all ports
function net.closeAll()
  for i = 1, 65535 do
    net.close(i)
  end
end

-- Strength getter and setter
function net.strength(n)
  if n ~= nil then
    modem.setStrength(n)
  else
    return modem.getStrength()

  end
end

-- Wake mesage getter and setter
function net.wakeMsg(msg, fuzzy)
  if msg ~= nil then
    modem.setWakeMessage(msg, fuzzy)
  else
    return modem.getWakeMessage()
  end
end

-- Send network packets
-- Auto serializes data for you
function net.send(addr, port, ...)
  addr = checkAddr(addr)
  local arg = table.pack(...)
  for k, v in ipairs(arg) do
    -- Only serialize tables
    if type(v) == "table" then
      arg[k] = serial.serialize(v)
    end
  end
  modem.send(addr, port, table.unpack(arg))

end

-- Broadcast network packets
-- Auto serializes data for you
function net.broadcast(port, ...)
  local arg = table.pack(...)
  for k, v in ipairs(arg) do
    -- Only serialize tables
    if type(v) == "table" then
      arg[k] = serial.serialize(v)
    end
  end
  modem.broadcast(port, table.unpack(arg))

end

-- Custom function to receive network packets
-- Can specify a port and or address for simple filtering
-- Can also supply a filter function in addition to simple filtering
-- If port supplied, default action is to open the port for you
-- If nonblocking, uses coroutine.yield() do be prepared to handle that
function net.recv(t)
  local pkt = {}
  local tmp = {}
  -- This allows default and keyword args
  if t ~= nil then
    setmetatable(t,{__index={
      port = nil,
      addr = nil,
      fuzzy = false,
      timeout = nil,
      filter = nil,
      open = true,
      nonblocking = false,
    }})
    local port, addr, timeout, filter, open, nonblocking =
      t[1] or t.port, 
      t[2] or t.addr,
      t[3] or t.timeout,
      t[4] or t.filter,
      t[5] or t.open,
      t[6] or t.nonblocking

    if addr ~= nil then
      addr = checkAddr(addr)
    end
    
    -- Automatically open port to listen on
    -- NOTE: Only works on a single port, if the filter function listens on 
    -- multiple you'll have to do that manually
    if open and net ~= nil then net.open(port) end
    
    ----------------
    -- Basic filter function used to call user defined filter functions
    function f(name, ...)
      -- Get rid of all non modem messages
      if name ~= "modem_message" then return false end
      local arg = {...}
      local resAddress, resPort = arg[2], arg[3]
      
      -- Check port is good
      if port ~= nil and resPort ~= port then
        return false
      end
      
      -- Check addr is good
      if resAddr ~= nil and resAddr == addr then
        return false
      end
      
      -- Do further filtering
      if filter ~= nil then
        return filter(name, ...)
      else
        return true
      end
    end
    ----------------
  
    if timeout ~= nil then
      tmp = {async.pullFiltered(timeout, f, not nonblocking)}
    else
      tmp = {async.pullFiltered(f, not nonblocking)}
    end
  end

  -- Check for non-packets
  if #tmp == 0 then
    return nil, "timeout"
  elseif tmp[1] == "interrupted" then
    return nil, "interrupted"
  end

  -- Create basis of packet
  pkt.laddr, pkt.raddr, pkt.port, pkt.distance, pkt.msg = tmp[2], tmp[3], tmp[4], tmp[5], tmp[6]
  
  local data = {}
  for i = 6, #tmp do
    -- Unserialize any serialized data
    if type(tmp[i]) == "string" then
      nonblocking, res = pcall(serial.unserialize, tmp[i])
      if nonblocking and res == nil then data[i-5] = tmp[i] else data[i-5] = res end
    else
      data[i-5] = tmp[i]
    end
  end
  pkt.data = data
  
  return pkt
end

-- wget -f http://localhost:8080/lib/net.lua /usr/lib/net.lua
-- wget -f http://mc.bashed.rocks:13699/lib/net.lua /usr/lib/net.lua

return net