+{-
+ - Copyright (C) 2015-2016 Ramakrishnan Muthukrishnan <ram@rkrishnan.org>
+ -
+ - This file is part of FuncTorrent.
+ -
+ - FuncTorrent is free software; you can redistribute it and/or modify
+ - it under the terms of the GNU General Public License as published by
+ - the Free Software Foundation; either version 3 of the License, or
+ - (at your option) any later version.
+ -
+ - FuncTorrent is distributed in the hope that it will be useful,
+ - but WITHOUT ANY WARRANTY; without even the implied warranty of
+ - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ - GNU General Public License for more details.
+ -
+ - You should have received a copy of the GNU General Public License
+ - along with FuncTorrent; if not, see <http://www.gnu.org/licenses/>
+ -}
+
{-# LANGUAGE OverloadedStrings #-}
+
module FuncTorrent.Peer
- (Peer(..),
+ (PieceMap,
handlePeerMsgs
) where
-import Prelude hiding (lookup, concat, replicate, splitAt, writeFile, take)
+import Prelude hiding (lookup, concat, replicate, splitAt, take, drop)
-import System.IO (Handle, BufferMode(..), IOMode(..), SeekMode(..), withFile, hSeek, hSetBuffering)
-import Data.ByteString (ByteString, pack, unpack, concat, hGet, hPut, singleton, writeFile, take, empty)
-import Data.ByteString.Lazy (fromStrict, fromChunks, toStrict)
-import qualified Data.ByteString.Char8 as BC (replicate, pack, length)
-import Network (connectTo, PortID(..))
-import Data.Binary (Binary(..), decode, encode)
-import Data.Binary.Put (putWord32be, putWord16be, putWord8)
-import Data.Binary.Get (getWord32be, getWord16be, getWord8, runGet)
-import Control.Monad (replicateM, liftM, forM)
-import Control.Applicative ((<$>), liftA3)
+import Control.Monad.State
+import Data.ByteString (ByteString, unpack, concat, hGet, hPut, take, drop, empty)
import Data.Bits
import Data.Word (Word8)
-import Data.Map (Map, fromList, toList, (!), mapWithKey, adjust)
-import qualified Crypto.Hash.SHA1 as SHA1 (hash)
-
-import FuncTorrent.Metainfo (Info(..), Metainfo(..))
-import FuncTorrent.Utils (splitN, splitNum)
-
-type ID = String
-type IP = String
-type Port = Integer
-
--- PeerState is a misnomer
-data PeerState = PeerState { handle :: Handle
- , peer :: Peer
- , meChoking :: Bool
- , meInterested :: Bool
- , heChoking :: Bool
- , heInterested :: Bool}
-
-data PieceDlState = Pending
- | InProgress
- | Have
- deriving (Show, Eq)
-
--- todo - map with index to a new data structure (peers who have that piece amd state)
-data PieceData = PieceData { peers :: [Peer] -- ^ list of peers who have this piece
- , state :: PieceDlState -- ^ state of the piece from download perspective.
- , hash :: ByteString -- ^ piece hash
- , len :: Integer } -- ^ piece length
-
--- which piece is with which peers
-type PieceMap = Map Integer PieceData
-
--- | Peer is a PeerID, IP address, port tuple
-data Peer = Peer ID IP Port
- deriving (Show, Eq)
+import Data.Map ((!), adjust)
+import Network (connectTo, PortID(..))
+import System.IO (Handle, BufferMode(..), hSetBuffering, hClose)
-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)
+import FuncTorrent.Metainfo (Metainfo(..))
+import FuncTorrent.PeerMsgs (Peer(..), PeerMsg(..), sendMsg, getMsg, genHandshakeMsg)
+import FuncTorrent.Utils (splitNum, verifyHash)
+import FuncTorrent.PieceManager (PieceDlState(..), PieceData(..), PieceMap, pickPiece, updatePieceAvailability)
+import qualified FuncTorrent.FileSystem as FS (MsgChannel, writePieceToDisk)
--- Make the initial Piece map, with the assumption that no peer has the
--- piece and that every piece is pending download.
-mkPieceMap :: Integer -> ByteString -> [Integer] -> PieceMap
-mkPieceMap numPieces pieceHash pLengths = fromList kvs
- where kvs = [(i, PieceData { peers = []
- , state = Pending
- , hash = h
- , len = pLen })
- | (i, h, pLen) <- zip3 [0..numPieces] hashes pLengths]
- hashes = splitN (fromIntegral numPieces) pieceHash
+data PState = PState { handle :: Handle
+ , peer :: Peer
+ , meChoking :: Bool
+ , meInterested :: Bool
+ , heChoking :: Bool
+ , heInterested :: Bool}
havePiece :: PieceMap -> Integer -> Bool
havePiece pm index =
- state (pm ! index) == Have
+ dlstate (pm ! index) == Have
-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
-
-handShake :: Peer -> ByteString -> String -> IO Handle
-handShake peer@(Peer _ ip port) infoHash peerid = do
- let hs = genHandShakeMsg infoHash peerid
+connectToPeer :: Peer -> IO Handle
+connectToPeer (Peer ip port) = do
h <- connectTo ip (PortNumber (fromIntegral port))
hSetBuffering h LineBuffering
- hPut h hs
- putStrLn $ "--> handhake to peer: " ++ show peer
- _ <- hGet h (length (unpack hs))
- putStrLn $ "<-- handshake from peer: " ++ show peer
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: " ++ show msgid)
-
-getMsg :: Handle -> IO PeerMsg
-getMsg h = do
- lBS <- hGet h 4
- let l = bsToInt lBS
- if l == 0
- then return KeepAliveMsg
+doHandshake :: Bool -> Handle -> Peer -> ByteString -> String -> IO ()
+doHandshake True h p infohash peerid = do
+ let hs = genHandshakeMsg infohash peerid
+ hPut h hs
+ putStrLn $ "--> handhake to peer: " ++ show p
+ _ <- hGet h (length (unpack hs))
+ putStrLn $ "<-- handshake from peer: " ++ show p
+ return ()
+doHandshake False h p infohash peerid = do
+ let hs = genHandshakeMsg infohash peerid
+ putStrLn "waiting for a handshake"
+ hsMsg <- hGet h (length (unpack hs))
+ putStrLn $ "<-- handshake from peer: " ++ show p
+ let rxInfoHash = take 20 $ drop 28 hsMsg
+ if rxInfoHash /= infohash
+ then do
+ putStrLn "infoHashes does not match"
+ hClose h
+ return ()
else do
- msg <- hGet h l
- return $ decode $ fromStrict $ concat [lBS, msg]
-
-sendMsg :: Handle -> PeerMsg -> IO ()
-sendMsg h msg =
- let bsMsg = toStrict $ encode msg
- in
- hPut h bsMsg
-
-bsToInt :: ByteString -> Int
-bsToInt x = fromIntegral (runGet getWord32be (fromChunks (return x)))
+ _ <- hPut h hs
+ putStrLn $ "--> handhake to peer: " ++ show p
+ return ()
bitfieldToList :: [Word8] -> [Integer]
bitfieldToList bs = go bs 0
in
setBits ++ go bs' (pos + 1)
-createDummyFile :: FilePath -> Int -> IO ()
-createDummyFile path size =
- writeFile path (BC.replicate size '\0')
-
--- write into a file at a specific offet
-writeFileAtOffset :: FilePath -> Integer -> ByteString -> IO ()
-writeFileAtOffset path offset block =
- withFile path ReadWriteMode $ (\h -> do
- _ <- hSeek h AbsoluteSeek offset
- hPut h block)
-
--- recvMsg :: Peer -> Handle -> Msg
-msgLoop :: PeerState -> PieceMap -> IO ()
-msgLoop pState pieceStatus | meInterested pState == False &&
- heChoking pState == True = do
- -- if me NOT Interested and she is Choking, tell her that
- -- I am interested.
- let h = handle pState
- sendMsg h InterestedMsg
- putStrLn $ "--> InterestedMsg to peer: " ++ show (peer pState)
- msgLoop (pState { meInterested = True }) pieceStatus
- | meInterested pState == True &&
- heChoking pState == False =
- -- if me Interested and she not Choking, send her a request
- -- for a piece.
- case pickPiece pieceStatus of
- Nothing -> putStrLn "Nothing to download"
- Just workPiece -> do
- let pLen = len (pieceStatus ! workPiece)
- pBS <- downloadPiece (handle pState) workPiece pLen
- -- if not $ verifyHash pBS (hash (pieceStatus ! workPiece))
- -- then
- -- putStrLn $ "Hash mismatch: " ++ show (hash (pieceStatus ! workPiece)) ++ " vs " ++ show (take 20 (SHA1.hash pBS))
- -- else do
- writeFileAtOffset "/tmp/download.file" (workPiece * pLen) pBS
- msgLoop pState (adjust (\pieceData -> pieceData { state = Have }) workPiece pieceStatus)
- | otherwise = do
- msg <- getMsg (handle pState)
- putStrLn $ "<-- " ++ show msg ++ "from peer: " ++ show (peer pState)
- case msg of
- KeepAliveMsg -> do
- sendMsg (handle pState) KeepAliveMsg
- putStrLn $ "--> " ++ "KeepAliveMsg to peer: " ++ show (peer pState)
- msgLoop pState pieceStatus
- BitFieldMsg bss -> do
- let pieceList = bitfieldToList (unpack bss)
- pieceStatus' = updatePieceAvailability pieceStatus (peer pState) pieceList
- putStrLn $ show (length pieceList) ++ " Pieces"
- -- for each pieceIndex in pieceList, make an entry in the pieceStatus
- -- map with pieceIndex as the key and modify the value to add the peer.
- -- download each of the piece in order
- msgLoop pState pieceStatus'
- UnChokeMsg -> do
- msgLoop (pState { heChoking = False }) pieceStatus
- _ -> do
- msgLoop pState pieceStatus
-
--- simple algorithm to pick piece.
--- pick the first piece from 0 that is not downloaded yet.
-pickPiece :: PieceMap -> Maybe Integer
-pickPiece m =
- let pieceList = toList m
- allPending = filter (\(_, v) -> state v == Pending) pieceList
- in
- case allPending of
- [] -> Nothing
- ((i, _):_) -> Just i
+-- helper functions to manipulate PeerState
+toPeerState :: Handle
+ -> Peer
+ -> Bool -- ^ meChoking
+ -> Bool -- ^ meInterested
+ -> Bool -- ^ heChoking
+ -> Bool -- ^ heInterested
+ -> PState
+toPeerState h p meCh meIn heCh heIn =
+ PState { handle = h
+ , peer = p
+ , heChoking = heCh
+ , heInterested = heIn
+ , meChoking = meCh
+ , meInterested = meIn }
+
+handlePeerMsgs :: Peer -> String -> Metainfo -> PieceMap -> Bool -> FS.MsgChannel -> IO ()
+handlePeerMsgs p peerId m pieceMap isClient c = do
+ h <- connectToPeer p
+ doHandshake isClient h p (infoHash m) peerId
+ let pstate = toPeerState h p False False True True
+ _ <- runStateT (msgLoop pieceMap c) pstate
+ return ()
+
+msgLoop :: PieceMap -> FS.MsgChannel -> StateT PState IO ()
+msgLoop pieceStatus msgchannel = do
+ h <- gets handle
+ st <- get
+ case st of
+ PState { meInterested = False, heChoking = True } -> do
+ liftIO $ sendMsg h InterestedMsg
+ gets peer >>= (\p -> liftIO $ putStrLn $ "--> InterestedMsg to peer: " ++ show p)
+ modify (\st' -> st' { meInterested = True })
+ msgLoop pieceStatus msgchannel
+ PState { meInterested = True, heChoking = False } ->
+ case pickPiece pieceStatus of
+ Nothing -> liftIO $ putStrLn "Nothing to download"
+ Just workPiece -> do
+ let pLen = len (pieceStatus ! workPiece)
+ liftIO $ putStrLn $ "piece length = " ++ show pLen
+ pBS <- liftIO $ downloadPiece h workPiece pLen
+ if not $ verifyHash pBS (hash (pieceStatus ! workPiece))
+ then
+ liftIO $ putStrLn "Hash mismatch"
+ else do
+ liftIO $ putStrLn $ "Write piece: " ++ show workPiece
+ liftIO $ FS.writePieceToDisk msgchannel workPiece pBS
+ msgLoop (adjust (\pieceData -> pieceData { dlstate = Have }) workPiece pieceStatus) msgchannel
+ _ -> do
+ msg <- liftIO $ getMsg h
+ gets peer >>= (\p -> liftIO $ putStrLn $ "<-- " ++ show msg ++ " from peer: " ++ show p)
+ case msg of
+ KeepAliveMsg -> do
+ liftIO $ sendMsg h KeepAliveMsg
+ gets peer >>= (\p -> liftIO $ putStrLn $ "--> " ++ "KeepAliveMsg to peer: " ++ show p)
+ msgLoop pieceStatus msgchannel
+ BitFieldMsg bss -> do
+ p <- gets peer
+ let pieceList = bitfieldToList (unpack bss)
+ pieceStatus' = updatePieceAvailability pieceStatus p pieceList
+ liftIO $ putStrLn $ show (length pieceList) ++ " Pieces"
+ -- for each pieceIndex in pieceList, make an entry in the pieceStatus
+ -- map with pieceIndex as the key and modify the value to add the peer.
+ -- download each of the piece in order
+ msgLoop pieceStatus' msgchannel
+ UnChokeMsg -> do
+ modify (\st' -> st' {heChoking = False })
+ msgLoop pieceStatus msgchannel
+ ChokeMsg -> do
+ modify (\st' -> st' {heChoking = True })
+ msgLoop pieceStatus msgchannel
+ InterestedMsg -> do
+ modify (\st' -> st' {heInterested = True})
+ msgLoop pieceStatus msgchannel
+ NotInterestedMsg -> do
+ modify (\st' -> st' {heInterested = False})
+ msgLoop pieceStatus msgchannel
+ CancelMsg _ _ _ -> -- check if valid index, begin, length
+ msgLoop pieceStatus msgchannel
+ PortMsg _ ->
+ msgLoop pieceStatus msgchannel
+ HaveMsg idx -> do
+ p <- gets peer
+ let pieceStatus' = updatePieceAvailability pieceStatus p [idx]
+ msgLoop pieceStatus' msgchannel
+ _ -> do
+ liftIO $ putStrLn $ ".. not doing anything with the msg"
+ msgLoop pieceStatus msgchannel
+ -- No need to handle PieceMsg and RequestMsg here.
-updatePieceAvailability :: PieceMap -> Peer -> [Integer] -> PieceMap
-updatePieceAvailability pieceStatus p pieceList =
- mapWithKey (\k pd -> if k `elem` pieceList
- then (pd { peers = p : (peers pd) })
- else pd) pieceStatus
-handlePeerMsgs :: Peer -> Metainfo -> String -> IO ()
-handlePeerMsgs p m peerId = do
- h <- handShake p (infoHash m) peerId
- let state = PeerState { handle = h
- , peer = p
- , heInterested = False
- , heChoking = True
- , meInterested = False
- , meChoking = True }
- pieceHash = pieces (info m)
- numPieces = (toInteger . (`quot` 20) . BC.length) pieceHash
- pLen = pieceLength (info m)
- fileLen = lengthInBytes (info m)
- pieceStatus = mkPieceMap numPieces pieceHash (splitNum fileLen pLen)
- createDummyFile "/tmp/download.file" (fromIntegral fileLen)
- msgLoop state pieceStatus
-
downloadPiece :: Handle -> Integer -> Integer -> IO ByteString
downloadPiece h index pieceLength = do
let chunks = splitNum pieceLength 16384
- liftM concat $ forM (zip [0..] chunks) (\(i, pLen) -> do
- sendMsg h (RequestMsg index (i*pLen) pLen)
- putStrLn $ "--> " ++ "RequestMsg for Piece "
- ++ (show index) ++ ", part: " ++ show i ++ " of length: "
- ++ show pLen
- msg <- getMsg h
- case msg of
- PieceMsg index begin block -> do
- putStrLn $ " <-- PieceMsg for Piece: "
- ++ show index
- ++ ", offset: "
- ++ show begin
- return block
- _ -> do
- putStrLn "ignoring irrelevant msg"
- return empty)
+ concat `liftM` forM (zip [0..] chunks) (\(i, pLen) -> do
+ sendMsg h (RequestMsg index (i*pLen) pLen)
+ putStrLn $ "--> " ++ "RequestMsg for Piece "
+ ++ show index ++ ", part: " ++ show i ++ " of length: "
+ ++ show pLen
+ msg <- getMsg h
+ case msg of
+ PieceMsg index begin block -> do
+ putStrLn $ " <-- PieceMsg for Piece: "
+ ++ show index
+ ++ ", offset: "
+ ++ show begin
+ return block
+ _ -> do
+ putStrLn $ "ignoring irrelevant msg: " ++ show msg
+ return empty)
-verifyHash :: ByteString -> ByteString -> Bool
-verifyHash bs pieceHash =
- take 20 (SHA1.hash bs) == pieceHash
projects / functorrent.git / blobdiff