~ Rename modules.

1 files changed, 79 insertions, 0 deletions

diff --git a/src/Network/BitTorrent/PeerWire/Handshake.hs b/src/Network/BitTorrent/PeerWire/Handshake.hs
new file mode 100644
index 00000000..6ce37887
--- /dev/null
+++ b/src/Network/BitTorrent/PeerWire/Handshake.hs
@@ -0,0 +1,79 @@
+-- |
+--   Copyright   :  (c) Sam T. 2013
+--   License     :  MIT
+--   Maintainer  :  pxqr.sta@gmail.com
+--   Stability   :  experimental
+--   Portability :  portable
+--
+{-# LANGUAGE OverloadedStrings #-}
+module Network.BitTorrent.PeerWire.Handshake
+       ( Handshake
+       , handshakeMaxSize
+       , defaultBTProtocol, defaultReserved, defaultHandshake
+       , handshake
+       ) where
+
+import Control.Applicative
+import Data.Word
+import           Data.ByteString (ByteString)
+import qualified Data.ByteString as B
+import Data.Serialize as S
+import Data.Torrent.InfoHash
+import Network
+import Network.Socket.ByteString
+
+import Network.BitTorrent.PeerID
+
+
+-- | In order to establish the connection between peers we should send 'Handshake'
+--   message. The 'Handshake' is a required message and must be the first message
+--   transmitted by the peer to the another peer.
+data Handshake = Handshake {
+    hsProtocol    :: ByteString  -- ^ Identifier of the protocol.
+  , hsReserved    :: Word64      -- ^ Reserved bytes, rarely used.
+  , hsInfoHash    :: InfoHash    -- ^ Hash from the metainfo file.
+    -- This /should be/ same hash that is transmitted in tracker requests.
+  , hsPeerID      :: PeerID      -- ^ Peer id of the initiator.
+    -- This is /usually the same peer id that is transmitted in tracker requests.
+  } deriving (Show, Eq)
+
+instance Serialize Handshake where
+  put hs = do
+    putWord8 (fromIntegral (B.length (hsProtocol hs)))
+    putByteString (hsProtocol hs)
+    putWord64be   (hsReserved hs)
+    put (hsInfoHash hs)
+    put (hsPeerID hs)
+
+  get = do
+    len  <- getWord8
+    Handshake <$> getBytes (fromIntegral len)
+              <*> getWord64be
+              <*> get
+              <*> get
+
+-- | Maximum size of handshake message in bytes.
+handshakeMaxSize :: Int
+handshakeMaxSize = 1 + 256 + 8 + 20 + 20
+
+-- | Default protocol string "BitTorrent protocol" as is.
+defaultBTProtocol :: ByteString
+defaultBTProtocol = "BitTorrent protocol"
+
+-- | Default reserved word is 0.
+defaultReserved :: Word64
+defaultReserved = 0
+
+-- | Length of info hash and peer id is unchecked, so it /should/ be equal 20.
+defaultHandshake :: InfoHash -> PeerID -> Handshake
+defaultHandshake = Handshake defaultBTProtocol defaultReserved
+
+
+-- TODO check if hash the same
+-- | Handshaking with a peer specified by the second argument.
+--
+handshake :: Socket -> Handshake -> IO (Either String Handshake)
+handshake sock hs = do
+  sendAll sock (S.encode hs)
+  r <- recv sock handshakeMaxSize
+  return (S.decode r)