]> git.rkrishnan.org Git - functorrent.git/blobdiff - src/FuncTorrent/Peer.hs
rename shadowing identifiers
[functorrent.git] / src / FuncTorrent / Peer.hs
index 105994d2ccdf502bbf3029206f41144f05463dec..c2268e894c94b3275a025f1742971745849f9dda 100644 (file)
+{-# LANGUAGE OverloadedStrings #-}
 module FuncTorrent.Peer
-    (Peer,
-     PeerResp(..),
-     getPeerResponse,
-     handShakeMsg
+    (Peer(..),
+     handShake
     ) where
 
 import Prelude hiding (lookup, concat, replicate, splitAt)
-import Data.ByteString.Char8 (ByteString, pack, unpack, concat, replicate, splitAt)
-import Data.ByteString.Lazy (toChunks)
-import Data.Int (Int8)
-import Data.List (intercalate)
-import Data.Map as M ((!), lookup)
-import qualified Data.Binary as Bin (encode)
-import qualified Data.ByteString.Base16 as B16 (encode)
 
-import FuncTorrent.Bencode (BVal(..), InfoDict, decode)
-import FuncTorrent.Tracker (infoHash)
-import FuncTorrent.Utils (splitN)
+import System.IO
+import Data.ByteString (ByteString, pack, unpack, concat, hGet, hPut, singleton)
+import qualified Data.ByteString.Char8 as BC (replicate, pack)
+import Network (connectTo, PortID(..))
+import Data.Binary (Binary(..))
+import Data.Binary.Put (putWord32be, putWord16be, putWord8)
+import Data.Binary.Get (getWord32be, getWord16be, getWord8)
+import Control.Monad (replicateM, liftM)
+import Control.Applicative ((<$>), liftA3)
 
-
-type Address = String
+type ID = String
+type IP = String
 type Port = Integer
 
-data Peer = Peer Address Port
-            deriving (Show)
+data PeerState = PeerState { handle :: Handle
+                           , am_choking :: Bool
+                           , am_interested :: Bool
+                           , peer_choking :: Bool
+                           , peer_interested :: Bool }
+
+-- Maintain info on every piece and the current state of it.
+-- should probably be a TVar.
+type Pieces = [PieceData]
+
+data PieceState = Pending
+                | InProgress
+                | Have
+                deriving (Show)
+
+data PieceData = PieceData { index :: Int           -- ^ Piece number
+                           , peers :: [Peer]        -- ^ list of peers who have this piece
+                           , state :: PieceState }  -- ^ state of the piece from download perspective.
 
-data PeerResp = PeerResponse { interval :: Maybe Integer
-                             , peers :: [Peer]
-                             , complete :: Maybe Integer
-                             , incomplete :: Maybe Integer
-                             } deriving (Show)
+-- | Peer is a PeerID, IP address, port tuple
+data Peer = Peer ID IP Port
+          deriving (Show, Eq)
 
-toInt :: String -> Integer
-toInt = read
+data PeerMsg = KeepAliveMsg
+             | ChokeMsg
+             | UnChokeMsg
+             | InterestedMsg
+             | NotInterestedMsg
+             | HaveMsg Integer
+             | BitFieldMsg ByteString
+             | RequestMsg Integer Integer Integer
+             | PieceMsg Integer Integer ByteString
+             | CancelMsg Integer Integer Integer
+             | PortMsg Port
+             deriving (Show)
 
-getPeerResponse :: ByteString -> PeerResp
-getPeerResponse body = case decode body of
-                        Right (Bdict peerM) ->
-                          let (Just (Bint i)) = lookup (Bstr (pack "lookup")) peerM
-                              (Bstr peersBS) = peerM ! Bstr (pack "peers")
-                              pl = map (\peer -> let (ip', port') = splitAt 4 peer
-                                                 in Peer (toIPNum ip') (toPortNum port'))
-                                   (splitN 6 peersBS)
-                          in PeerResponse { interval = Just i
-                                          , peers = pl
-                                          , complete = Nothing
-                                          , incomplete = Nothing
-                                          }
-                          where toPortNum = read . ("0x" ++) . unpack . B16.encode
-                                toIPNum = intercalate "." .
-                                          map (show . toInt . ("0x" ++) . unpack) .
-                                          splitN 2 . B16.encode
+genHandShakeMsg :: ByteString -> String -> ByteString
+genHandShakeMsg infoHash peer_id = concat [pstrlen, pstr, reserved, infoHash, peerID]
+  where pstrlen = singleton 19
+        pstr = BC.pack "BitTorrent protocol"
+        reserved = BC.replicate 8 '\0'
+        peerID = BC.pack peer_id
 
-                        _ -> PeerResponse { interval = Nothing
-                                          , peers = []
-                                          , complete = Nothing
-                                          , incomplete = Nothing
-                                          }
+handShake :: Peer -> ByteString -> String -> IO Handle
+handShake (Peer _ ip port) infoHash peerid = do
+  let hs = genHandShakeMsg infoHash peerid
+  h <- connectTo ip (PortNumber (fromIntegral port))
+  hSetBuffering h LineBuffering
+  hPut h hs
+  rlenBS <- hGet h 1
+  let rlen = fromIntegral $ (unpack rlenBS) !! 0
+  hGet h rlen
+  return h
 
+instance Binary PeerMsg where
+  put msg = case msg of
+             KeepAliveMsg -> putWord32be 0
+             ChokeMsg -> do putWord32be 1
+                            putWord8 0
+             UnChokeMsg -> do putWord32be 1
+                              putWord8 1
+             InterestedMsg -> do putWord32be 1
+                                 putWord8 2
+             NotInterestedMsg -> do putWord32be 1
+                                    putWord8 3
+             HaveMsg i -> do putWord32be 5
+                             putWord8 4
+                             putWord32be (fromIntegral i)
+             BitFieldMsg bf -> do putWord32be $ fromIntegral (1 + bfListLen)
+                                  putWord8 5
+                                  mapM_ putWord8 bfList
+                                    where bfList = unpack bf
+                                          bfListLen = length bfList
+             RequestMsg i o l -> do putWord32be 13
+                                    putWord8 6
+                                    putWord32be (fromIntegral i)
+                                    putWord32be (fromIntegral o)
+                                    putWord32be (fromIntegral l)
+             PieceMsg i o b -> do putWord32be $ fromIntegral (9 + blocklen)
+                                  putWord8 7
+                                  putWord32be (fromIntegral i)
+                                  putWord32be (fromIntegral o)
+                                  mapM_ putWord8 blockList
+                                    where blockList = unpack b
+                                          blocklen = length blockList
+             CancelMsg i o l -> do putWord32be 13
+                                   putWord8 8
+                                   putWord32be (fromIntegral i)
+                                   putWord32be (fromIntegral o)
+                                   putWord32be (fromIntegral l)
+             PortMsg p -> do putWord32be 3
+                             putWord8 9
+                             putWord16be (fromIntegral p)
+  get = do
+    l <- getWord32be
+    msgid <- getWord8
+    case msgid of
+     0 -> return ChokeMsg
+     1 -> return UnChokeMsg
+     2 -> return InterestedMsg
+     3 -> return NotInterestedMsg
+     4 -> liftM (HaveMsg . fromIntegral) getWord32be
+     5 -> liftM (BitFieldMsg . pack) (replicateM (fromIntegral l - 1) getWord8)
+     6 -> liftA3 RequestMsg getInteger getInteger getInteger
+       where getInteger = fromIntegral <$> getWord32be
+     7 -> liftA3 PieceMsg getInteger getInteger (pack  <$> replicateM (fromIntegral l - 9) getWord8)
+       where getInteger = fromIntegral <$> getWord32be
+     8 -> liftA3 CancelMsg getInteger getInteger getInteger
+       where getInteger = fromIntegral <$> getWord32be
+     9 -> liftM (PortMsg . fromIntegral) getWord16be
+     _ -> error "unknown message ID"
 
-handShakeMsg :: InfoDict -> String -> ByteString
-handShakeMsg m peer_id = let pstrlen = concat $ toChunks $ Bin.encode (19 :: Int8)
-                             pstr = pack "BitTorrent protocol"
-                             reserved = replicate 8 '\0'
-                             infoH = infoHash m
-                             peerID = pack peer_id
-                         in concat [pstrlen, pstr, reserved, infoH, peerID]
+-- loop1 :: shake hands with all peers, find out the pieces they have, form PieceData.
+-- recvMsg :: Peer -> Handle -> Msg