Connection.hs

-- |
-- Module      : Network.TLS.Extra.Connection
-- License     : BSD-style
-- Maintainer  : Vincent Hanquez <vincent@snarc.org>
-- Stability   : experimental
-- Portability : unknown
--
module Network.TLS.Extra.Connection
	( connectionClient
	) where

import Crypto.Random
import Control.Applicative ((<$>))
import Control.Exception
import Data.Char

import System.IO

import Network.BSD
import Network.Socket
import Network.TLS

-- | @connectionClient host port param rng@ opens a TCP client connection
-- to a destination host and port description (number or name). For
-- example:
-- 
-- @
-- import Network.TLS.Extra
-- import Crypto.Random
-- ...
--   conn <- (newGenIO::IO SystemRandom) >>= connectionClient 192.168.2.2 7777 defaultParams g
-- @
--
-- will make a new RNG (using system entropy) and connect to IP 192.168.2.2
-- on port 7777.
connectionClient :: CryptoRandomGen g => String -> String -> TLSParams -> g -> IO Context
connectionClient s p params rng = do
	pn <- if and $ map isDigit $ p
		then return $ fromIntegral $ (read p :: Int)
		else servicePort <$> getServiceByName p "tcp"
	he <- getHostByName s

	h <- bracketOnError (socket AF_INET Stream defaultProtocol) sClose $ \sock -> do
		connect sock (SockAddrInet pn (head $ hostAddresses he))
		socketToHandle sock ReadWriteMode
	contextNewOnHandle h params rng