-- | -- Copyright : (c) Sam Truzjan 2013 -- License : BSD3 -- Maintainer : pxqr.sta@gmail.com -- Stability : experimental -- Portability : portable -- -- 'PeerID' represent self assigned peer identificator. Ideally each -- host in the network should have unique peer id to avoid -- collisions, therefore for peer ID generation we use good entropy -- source. (FIX not really) Peer ID is sent in /tracker request/, -- sent and received in /peer handshakes/ and used in /distributed -- hash table/ queries. -- {-# LANGUAGE GeneralizedNewtypeDeriving #-} module Network.BitTorrent.Core.PeerId ( -- * PeerId PeerId (getPeerId) -- * Generation , genPeerId , timestamp , entropy -- * Encoding , azureusStyle , shadowStyle -- * Decoding , clientInfo -- ** Extra , byteStringPadded , defaultClientId , defaultVersionNumber ) where import Control.Applicative import Data.Aeson import Data.BEncode as BE import Data.ByteString as BS import Data.ByteString.Internal as BS import Data.ByteString.Char8 as BC import qualified Data.ByteString.Lazy as BL import qualified Data.ByteString.Lazy.Builder as BS import Data.Default import Data.Foldable (foldMap) import Data.List as L import Data.List.Split as L import Data.Maybe (fromMaybe, catMaybes) import Data.Monoid import Data.Serialize as S import Data.String import Data.Time.Clock (getCurrentTime) import Data.Time.Format (formatTime) import Data.URLEncoded import Data.Version (Version(Version), versionBranch) import System.Entropy (getEntropy) import System.Locale (defaultTimeLocale) import Text.PrettyPrint hiding ((<>)) import Text.PrettyPrint.Class import Text.Read (readMaybe) import Paths_bittorrent (version) import Data.Torrent.Client -- TODO use unpacked form (length is known statically) -- | Peer identifier is exactly 20 bytes long bytestring. newtype PeerId = PeerId { getPeerId :: ByteString } deriving (Show, Eq, Ord, BEncode, ToJSON, FromJSON) instance Serialize PeerId where put = putByteString . getPeerId get = PeerId <$> getBytes 20 instance URLShow PeerId where urlShow = BC.unpack . getPeerId instance IsString PeerId where fromString str | BS.length bs == 20 = PeerId bs | otherwise = error $ "Peer id should be 20 bytes long: " ++ show str where bs = fromString str instance Pretty PeerId where pretty = text . BC.unpack . getPeerId {----------------------------------------------------------------------- -- Encoding -----------------------------------------------------------------------} -- | Pad bytestring so it's becomes exactly request length. Conversion -- is done like so: -- -- * length < size: Complete bytestring by given charaters. -- -- * length = size: Output bytestring as is. -- -- * length > size: Drop last (length - size) charaters from a -- given bytestring. -- byteStringPadded :: ByteString -- ^ bytestring to be padded. -> Int -- ^ size of result builder. -> Char -- ^ character used for padding. -> BS.Builder byteStringPadded bs s c = BS.byteString (BS.take s bs) <> BS.byteString (BC.replicate padLen c) where padLen = s - min (BS.length bs) s -- | Azureus-style encoding have the following layout: -- -- * 1 byte : '-' -- -- * 2 bytes: client id -- -- * 4 bytes: version number -- -- * 1 byte : '-' -- -- * 12 bytes: random number -- azureusStyle :: ByteString -- ^ 2 character client ID, padded with 'H'. -> ByteString -- ^ Version number, padded with 'X'. -> ByteString -- ^ Random number, padded with '0'. -> PeerId -- ^ Azureus-style encoded peer ID. azureusStyle cid ver rnd = PeerId $ BL.toStrict $ BS.toLazyByteString $ BS.char8 '-' <> byteStringPadded cid 2 'H' <> byteStringPadded ver 4 'X' <> BS.char8 '-' <> byteStringPadded rnd 12 '0' -- | Shadow-style encoding have the following layout: -- -- * 1 byte : client id. -- -- * 0-4 bytes: version number. If less than 4 then padded with -- '-' char. -- -- * 15 bytes : random number. If length is less than 15 then -- padded with '0' char. -- shadowStyle :: Char -- ^ Client ID. -> ByteString -- ^ Version number. -> ByteString -- ^ Random number. -> PeerId -- ^ Shadow style encoded peer ID. shadowStyle cid ver rnd = PeerId $ BL.toStrict $ BS.toLazyByteString $ BS.char8 cid <> byteStringPadded ver 4 '-' <> byteStringPadded rnd 15 '0' -- | "HS" - 2 bytes long client identifier. defaultClientId :: ByteString defaultClientId = "HS" -- | Gives exactly 4 bytes long version number for any version of the -- package. Version is taken from .cabal. defaultVersionNumber :: ByteString defaultVersionNumber = BS.take 4 $ BC.pack $ foldMap show $ versionBranch version {----------------------------------------------------------------------- -- Generation -----------------------------------------------------------------------} -- | Gives 15 characters long decimal timestamp such that: -- -- * 6 bytes : first 6 characters from picoseconds obtained with %q. -- -- * 1 bytes : character '.' for readability. -- -- * 9..* bytes: number of whole seconds since the Unix epoch -- (!)REVERSED. -- -- Can be used both with shadow and azureus style encoding. This -- format is used to make the ID's readable(for debugging) and more -- or less random. -- timestamp :: IO ByteString timestamp = (BC.pack . format) <$> getCurrentTime where format t = L.take 6 (formatTime defaultTimeLocale "%q" t) ++ "." ++ L.take 9 (L.reverse (formatTime defaultTimeLocale "%s" t)) -- | Gives 15 character long random bytestring. This is more robust -- method for generation of random part of peer ID than timestamp. entropy :: IO ByteString entropy = getEntropy 15 -- NOTE: entropy generates incorrrect peer id -- | Here we use Azureus-style encoding with the following args: -- -- * 'HS' for the client id. -- -- * Version of the package for the version number -- -- * UTC time day ++ day time for the random number. -- genPeerId :: IO PeerId genPeerId = azureusStyle defaultClientId defaultVersionNumber <$> timestamp {----------------------------------------------------------------------- -- Decoding -----------------------------------------------------------------------} parseImpl :: ByteString -> ClientImpl parseImpl = f . BC.unpack where f "AG" = IAres f "A~" = IAres f "AR" = IArctic f "AV" = IAvicora f "AX" = IBitPump f "AZ" = IAzureus f "BB" = IBitBuddy f "BC" = IBitComet f "BF" = IBitflu f "BG" = IBTG f "BR" = IBitRocket f "BS" = IBTSlave f "BX" = IBittorrentX f "CD" = IEnhancedCTorrent f "CT" = ICTorrent f "DE" = IDelugeTorrent f "DP" = IPropagateDataClient f "EB" = IEBit f "ES" = IElectricSheep f "FT" = IFoxTorrent f "GS" = IGSTorrent f "HL" = IHalite f "HS" = IlibHSbittorrent f "HN" = IHydranode f "KG" = IKGet f "KT" = IKTorrent f "LH" = ILH_ABC f "LP" = ILphant f "LT" = ILibtorrent f "lt" = ILibTorrent f "LW" = ILimeWire f "MO" = IMonoTorrent f "MP" = IMooPolice f "MR" = IMiro f "MT" = IMoonlightTorrent f "NX" = INetTransport f "PD" = IPando f "qB" = IqBittorrent f "QD" = IQQDownload f "QT" = IQt4TorrentExample f "RT" = IRetriever f "S~" = IShareaza f "SB" = ISwiftbit f "SS" = ISwarmScope f "ST" = ISymTorrent f "st" = Isharktorrent f "SZ" = IShareaza f "TN" = ITorrentDotNET f "TR" = ITransmission f "TS" = ITorrentstorm f "TT" = ITuoTu f "UL" = IuLeecher f "UT" = IuTorrent f "VG" = IVagaa f "WT" = IBitLet f "WY" = IFireTorrent f "XL" = IXunlei f "XT" = IXanTorrent f "XX" = IXtorrent f "ZT" = IZipTorrent f _ = IUnknown -- TODO use regexps -- | Tries to extract meaningful information from peer ID bytes. If -- peer id uses unknown coding style then client info returned is -- 'def'. -- clientInfo :: PeerId -> ClientInfo clientInfo pid = either (const def) id $ runGet getCI (getPeerId pid) where getCI = do leading <- BS.w2c <$> getWord8 case leading of '-' -> ClientInfo <$> getAzureusImpl <*> getAzureusVersion 'M' -> ClientInfo <$> pure IMainline <*> getMainlineVersion 'e' -> ClientInfo <$> getBitCometImpl <*> getBitCometVersion 'F' -> ClientInfo <$> getBitCometImpl <*> getBitCometVersion c -> do c1 <- w2c <$> lookAhead getWord8 if c1 == 'P' then do _ <- getWord8 ClientInfo <$> pure IOpera <*> getOperaVersion else ClientInfo <$> pure (getShadowImpl c) <*> getShadowVersion getMainlineVersion = do str <- BC.unpack <$> getByteString 7 let mnums = L.filter (not . L.null) $ L.linesBy ('-' ==) str return $ Version (fromMaybe [] $ sequence $ L.map readMaybe mnums) [] getAzureusImpl = parseImpl <$> getByteString 2 getAzureusVersion = mkVer <$> getByteString 4 where mkVer bs = Version [fromMaybe 0 $ readMaybe $ BC.unpack bs] [] getBitCometImpl = do bs <- getByteString 3 lookAhead $ do _ <- getByteString 2 lr <- getByteString 4 return $ if lr == "LORD" then IBitLord else if bs == "UTB" then IBitComet else if bs == "xbc" then IBitComet else def getBitCometVersion = do x <- getWord8 y <- getWord8 return $ Version [fromIntegral x, fromIntegral y] [] getOperaVersion = do str <- BC.unpack <$> getByteString 4 return $ Version [fromMaybe 0 $ readMaybe str] [] getShadowImpl 'A' = IABC getShadowImpl 'O' = IOspreyPermaseed getShadowImpl 'Q' = IBTQueue getShadowImpl 'R' = ITribler getShadowImpl 'S' = IShadow getShadowImpl 'T' = IBitTornado getShadowImpl _ = IUnknown decodeShadowVerNr :: Char -> Maybe Int decodeShadowVerNr c | '0' < c && c <= '9' = Just (fromEnum c - fromEnum '0') | 'A' < c && c <= 'Z' = Just ((fromEnum c - fromEnum 'A') + 10) | 'a' < c && c <= 'z' = Just ((fromEnum c - fromEnum 'a') + 36) | otherwise = Nothing getShadowVersion = do str <- BC.unpack <$> getByteString 5 return $ Version (catMaybes $ L.map decodeShadowVerNr str) []