diff --git a/ChangeLog.md b/ChangeLog.md new file mode 100644 --- /dev/null +++ b/ChangeLog.md @@ -0,0 +1,5 @@ +# Revision history for neko-obfs + +## 0.1.0.0 -- YYYY-mm-dd + +* First version. Released on an unsuspecting world. diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,202 @@ + + Apache License + Version 2.0, January 2004 + http://www.apache.org/licenses/ + + TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION + + 1. Definitions. + + "License" shall mean the terms and conditions for use, reproduction, + and distribution as defined by Sections 1 through 9 of this document. + + "Licensor" shall mean the copyright owner or entity authorized by + the copyright owner that is granting the License. + + "Legal Entity" shall mean the union of the acting entity and all + other entities that control, are controlled by, or are under common + control with that entity. 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For further +-- documentation, see http://haskell.org/cabal/users-guide/ + +name: neko-obfs +version: 0.1.0.0 +synopsis: a TCP tunnel with packet length obfuscation +description: Just another tool that helps accessing the internet +license: Apache-2.0 +license-file: LICENSE +author: Jinjing Wang +maintainer: nfjinjing@gmail.com +-- copyright: +category: Network +build-type: Simple +extra-source-files: ChangeLog.md + Readme.md +cabal-version: >=1.10 +homepage: http://github.com/nfjinjing/neko-obfs + +executable neko-obfs + main-is: Main.hs + + other-modules: Helper + , Options + , Parser + , Type + , Unsafe + -- other-extensions: + build-depends: base >=4.9 && <4.10 + , async + , attoparsec + , binary + , bytestring + , lens + , network + , network-simple + , optparse-generic + , pipes + , pipes-attoparsec + , pipes-network + , pipes-safe + , random + , text + , transformers + hs-source-dirs: src + default-language: Haskell2010 diff --git a/src/Helper.hs b/src/Helper.hs new file mode 100644 --- /dev/null +++ b/src/Helper.hs @@ -0,0 +1,35 @@ +{-# LANGUAGE OverloadedStrings #-} + +-- | + +module Helper where + +import Control.Lens +import Prelude hiding ((-), log) + +import Control.Concurrent.MVar (withMVar) +import Control.Monad (forever, when) +import Control.Monad.IO.Class (MonadIO(..)) +import Data.ByteString (ByteString) +import qualified Data.ByteString as B +import Data.Monoid ((<>)) +import Data.Text (Text) +import qualified Data.Text.IO as T +import Data.Text.Strict.Lens +import Pipes (Pipe, for, cat, yield) +import Pipes.Safe (catchP) + +import Unsafe (logLock) + +{-# INLINE (-) #-} +infixr 0 - +(-) :: (a -> b) -> a -> b +f - x = f x + +sync :: MonadIO m => IO a -> m a +sync io = liftIO - withMVar logLock - const io + +log :: MonadIO m => Text -> m () +log x = sync - T.putStrLn x + + diff --git a/src/Main.hs b/src/Main.hs new file mode 100644 --- /dev/null +++ b/src/Main.hs @@ -0,0 +1,147 @@ +{-# LANGUAGE OverloadedStrings #-} + +module Main where + +import Helper ((-), log) +import Prelude hiding ((-), log) + +import Control.Concurrent.Async (async, waitAnyCatchCancel, waitEitherCancel) +import Control.Lens +import Control.Monad (replicateM_, join) +import Control.Monad.IO.Class (MonadIO(..)) +import Control.Monad.Trans.State.Strict (runStateT) +import Data.Attoparsec.ByteString (parse, maybeResult) +import Data.ByteString (ByteString) +import qualified Data.ByteString as B +import qualified Data.ByteString.Builder as Builder +import qualified Data.ByteString.Char8 as BC +import Data.Monoid ((<>)) +import qualified Data.Text as T +import Data.Text.Lens +import Data.Text.Strict.Lens (utf8) +import Network.Simple.TCP (send) +import qualified Network.Socket as NS +import Pipes (runEffect, (>->), Pipe, for, yield, cat, Producer, Consumer) +import qualified Pipes.Attoparsec as PA +import Pipes.Network.TCP.Safe +import qualified Pipes.Prelude as P +import Pipes.Safe +import System.Random (randomIO) +import Options.Generic + +import Options (toConfig) +import Parser +import Type + + +obfsEncode :: (MonadIO m) => Integer -> Integer -> Pipe ByteString ByteString m a +obfsEncode bound randomness = do + for cat - \x -> do + let payloadLen = (fromIntegral - B.length x) + + randomLen <- + if (payloadLen > fromIntegral bound) + then pure 0 + else liftIO - randomIO <&> (`mod` fromIntegral randomness) + + yield - view strict - Builder.toLazyByteString - Builder.word32BE randomLen + replicateM_ (fromIntegral randomLen) - yield - BC.singleton 'a' + + yield - view strict - Builder.toLazyByteString - Builder.word32BE payloadLen + yield x + + +obfsDecode :: (MonadIO m) => Producer ByteString m a -> (ByteString -> m ()) -> m () +obfsDecode pull sink = do + (r, next) <- runStateT (PA.parse obfsParser) pull + case r of + Just (Right result@(_,_,_,payload)) -> do + -- log - view packed - show result + sink payload + obfsDecode next sink + _ -> pure () + +main :: IO () +main = do + config <- getRecord "a TCP tunnel with packet length obfuscation" <&> toConfig + + log - T.pack - show config + + let mtu = 4096 + timeout = fromIntegral - config ^. timeoutInSeconds * 1000000 + + let _localHost = config ^. localHost . re packed + _localPort = show - config ^. localPort + + _remoteHost = config ^. remoteHost . re packed + _remotePort = show - config ^. remotePort + + _fromSocket = fromSocketTimeout timeout + _toSocket = toSocketTimeout timeout + + localThread <- pure - + runSafeT . runEffect - serve (Host _localHost) _localPort - \(localSock, localSockAddr) -> do + log - "local accepted: " <> view packed (show localSockAddr) + + runSafeT . runEffect - + connect _remoteHost _remotePort - \(remoteSock, remoteSockAddr) -> do + + let + localPull = _fromSocket localSock mtu + + remotePull = _fromSocket remoteSock mtu + remotePush = _toSocket remoteSock + + + sendThread <- liftIO - async - runEffect - do + localPull >-> obfsEncode (config ^. bound) (config ^. randomness) + >-> remotePush + liftIO - NS.shutdown remoteSock NS.ShutdownSend + + recvThread <- liftIO - async - do + obfsDecode remotePull - send localSock + liftIO - NS.shutdown localSock NS.ShutdownSend + + liftIO - waitEitherCancel sendThread recvThread + + pure () + + remoteThread <- pure - + runSafeT . runEffect - serve (Host _remoteHost) _remotePort - \(remoteSock, remoteSockAddr) -> do + log - "remote accepted: " <> view packed (show remoteSockAddr) + + let _forwardHost = config ^. forwardHost . re packed + _forwardPort = show - config ^. forwardPort + + runSafeT . runEffect - + connect _forwardHost _forwardPort - \(forwardSock, forwardSockAddr) -> do + + let + remotePull = _fromSocket remoteSock mtu + remotePush = _toSocket remoteSock + + forwardPull = _fromSocket forwardSock mtu + + sendThread <- liftIO - async - do + obfsDecode remotePull - send forwardSock + liftIO - NS.shutdown forwardSock NS.ShutdownSend + + recvThread <- liftIO - async - runEffect - do + forwardPull >-> obfsEncode (config ^. bound) (config ^. randomness) + >-> remotePush + liftIO - NS.shutdown remoteSock NS.ShutdownSend + + liftIO - waitEitherCancel sendThread recvThread + + pure () + + + case config ^. role of + Local -> do + _ <- localThread + pure () + Remote -> do + _ <- remoteThread + pure () + + pure () diff --git a/src/Options.hs b/src/Options.hs new file mode 100644 --- /dev/null +++ b/src/Options.hs @@ -0,0 +1,46 @@ +-- | + +{-# LANGUAGE DeriveGeneric #-} + +module Options where + +import Options.Generic +import Data.Maybe (fromMaybe) + +import Type (Config(..), Role(..), defaultConfig) + +data TunnelOptions = TunnelOptions + { + localHost :: Maybe Text + , localPort :: Maybe Integer + , remoteHost :: Text + , remotePort :: Integer + , forwardHost :: Maybe Text + , forwardPort :: Maybe Integer + , remote :: Bool + , bound :: Maybe Integer + , randomness :: Maybe Integer + , timeoutInSeconds :: Maybe Integer + } + deriving (Generic, Show, Eq) + +instance ParseRecord TunnelOptions + + +toConfig :: TunnelOptions -> Config +toConfig o = + let c = defaultConfig + in + Config + { + _localHost = fromMaybe (_localHost c) (localHost o) + , _localPort = fromMaybe (_localPort c) (localPort o) + , _remoteHost = remoteHost o + , _remotePort = remotePort o + , _forwardHost = fromMaybe (_forwardHost c) (forwardHost o) + , _forwardPort = fromMaybe (_forwardPort c) (forwardPort o) + , _role = if remote o then Remote else Local + , _bound = fromMaybe (_bound c) (bound o) + , _randomness = fromMaybe (_randomness c) (randomness o) + , _timeoutInSeconds = fromMaybe (_timeoutInSeconds c) (timeoutInSeconds o) + } diff --git a/src/Parser.hs b/src/Parser.hs new file mode 100644 --- /dev/null +++ b/src/Parser.hs @@ -0,0 +1,21 @@ + +{-# LANGUAGE OverloadedStrings #-} +module Parser where + +import Control.Lens ((<&>), view, lazy) +import Data.Attoparsec.ByteString (Parser) +import qualified Data.Attoparsec.ByteString as P +import Data.Binary.Get +import Data.ByteString.Char8 (ByteString) +import Data.Word (Word32) +import GHC.Word (Word8) + +obfsParser :: Parser (Word32, ByteString, Word32, ByteString) +obfsParser = do + randomLen <- P.take 4 <&> runGet getWord32be . view lazy + + random <- P.take (fromIntegral randomLen) + payloadLen <- P.take 4 <&> runGet getWord32be . view lazy + + payload <- P.take (fromIntegral payloadLen) + pure (randomLen, random, payloadLen, payload) diff --git a/src/Type.hs b/src/Type.hs new file mode 100644 --- /dev/null +++ b/src/Type.hs @@ -0,0 +1,43 @@ +{-# LANGUAGE TemplateHaskell #-} +{-# LANGUAGE OverloadedStrings #-} + +module Type where + + +import Control.Lens +import Data.Text (Text) + +data Role = Local | Remote + deriving (Show, Eq) + +data Config = Config + { + _localHost :: Text + , _localPort :: Integer + , _remoteHost :: Text + , _remotePort :: Integer + , _forwardHost :: Text + , _forwardPort :: Integer + , _role :: Role + , _bound :: Integer + , _randomness :: Integer + , _timeoutInSeconds :: Integer + } + deriving (Show, Eq) + +makeLenses ''Config + + +defaultConfig = Config + { + _localHost = "127.0.0.1" + , _localPort = 1080 + , _remoteHost = "127.0.0.1" + , _remotePort = 13148 + , _forwardHost = "127.0.0.1" + , _forwardPort = 1080 + , _role = Local + , _bound = 1024 + , _randomness = 300 + , _timeoutInSeconds = 3600 + } diff --git a/src/Unsafe.hs b/src/Unsafe.hs new file mode 100644 --- /dev/null +++ b/src/Unsafe.hs @@ -0,0 +1,8 @@ +module Unsafe where + + +import Control.Concurrent.MVar +import System.IO.Unsafe + +logLock :: MVar () +logLock = unsafePerformIO (newMVar ())