diff --git a/COPYING b/COPYING new file mode 100644 --- /dev/null +++ b/COPYING @@ -0,0 +1,674 @@ + GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. By contrast, +the GNU General Public License is intended to guarantee your freedom to +share and change all versions of a program--to make sure it remains free +software for all its users. We, the Free Software Foundation, use the +GNU General Public License for most of our software; it applies also to +any other work released this way by its authors. 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If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +. diff --git a/ChangeLog.md b/ChangeLog.md new file mode 100644 --- /dev/null +++ b/ChangeLog.md @@ -0,0 +1,3 @@ +# 0.1.0.0 + +* Initial release. diff --git a/README.md b/README.md new file mode 100644 --- /dev/null +++ b/README.md @@ -0,0 +1,45 @@ +# Bindings to libtelnet + +This is a wrapper around +[libtelnet](https://github.com/seanmiddleditch/libtelnet), a C library +for handling Telnet streams, including option negotiation, &c. As a +cleartext protocol, Telnet is thorougly unsuitable for use on the open +internet, but you might have a niche where it makes sense: + +* [MU*](https://en.wikipedia.org/wiki/MU*) games still use it, and so + the clients people want to use only speak Telnet, +* You might be speaking Telnet inside a + [stunnel](https://www.stunnel.org/), or +* You might have some ancient hardware that can't be updated, and + doesn't have ssh, but you want to talk to it using Haskell. + +This library hews closely to the interface provided by the C +libtelnet, so reading the [excellent C +documentation](https://github.com/seanmiddleditch/libtelnet#ii-api) +will help you. The short version goes something like this: + +1. Define an _event handler_ of type + `Network.Telnet.LibTelnet.EventHandler`. This function receives + callbacks that tell you what received data should be propagated to + the application, and what bytes need to be sent out over the + socket. + +2. Pass your event handler (and some other flags) to + `Network.Telnet.LibTelnet.telnetInit`, which will give you access + to a `Telnet`, a garbage-collected _state tracker_. + +3. Tell the state tracker that data has arrived on the socket, or that + you want to send data to the socket, by passing it to the library's + other functions. + +## Other Resources + +* A simple server example exists in + [`example/Main.hs`](https://git.sr.ht/~jack/libtelnet-haskell/tree/master/example/Main.hs). + +* Questions should go to the + [libtelnet-haskell-discuss](https://lists.sr.ht/~jack/libtelnet-haskell-discuss) + mailing list. + +* Bug reports should go to the + [bug tracker](https://todo.sr.ht/~jack/libtelnet-haskell). diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,2 @@ +import Distribution.Simple +main = defaultMain diff --git a/example/Main.hs b/example/Main.hs new file mode 100644 --- /dev/null +++ b/example/Main.hs @@ -0,0 +1,43 @@ +{- + +This is a minimal telnet server that echoes its input back to the +client: + +* All data that arrives on the socket is logged to stdout with a + "Socket: " prefix and then fed to the state tracker. + +* When the event handler is called with a 'Telnet.Received' event, it + prints the received data to stdout with an "R: " prefix, and sends it + to the same state tracker. + +* This triggers a 'Telnet.Send' event - "you should send this + over the wire" - so we log it to stdout with an "S: " prefix and + send it back over the socket. + +* All other telnet features (IAC sequences, option negotiation, etc.) + are ignored. + +-} + +module Main where + +import Control.Monad.Loops (whileJust_) +import qualified Data.ByteString.Char8 as B8 +import Network.Simple.TCP (HostPreference(..), Socket, recv, send, serve) +import qualified Network.Telnet.LibTelnet as Telnet + +telnetH :: Socket -> Telnet.EventHandler +telnetH _ t (Telnet.Received b) + = putStr "R: " *> B8.putStrLn b *> Telnet.telnetSend t b +telnetH s _ (Telnet.Send b) + = putStr "S: " *> send s b +telnetH _ _ _ = pure () + +main :: IO () +main = serve HostAny "4000" (\(s, _) -> handle s) where + handle s = do + telnet <- Telnet.telnetInit [] [] (telnetH s) + whileJust_ (recv s 4096) $ \bs -> do + putStr "Socket: " + B8.putStrLn bs + Telnet.telnetRecv telnet bs diff --git a/libtelnet.cabal b/libtelnet.cabal new file mode 100644 --- /dev/null +++ b/libtelnet.cabal @@ -0,0 +1,62 @@ +cabal-version: 2.2 +name: libtelnet +version: 0.1.0.0 +synopsis: Bindings to libtelnet +description: Binds https://github.com/seanmiddleditch/libtelnet , a C + library for writing telnet clients and + servers. See @README.md@ or + "Network.Telnet.LibTelnet" to get started. +homepage: https://git.sr.ht/~jack/libtelnet-haskell +bug-reports: https://todo.sr.ht/~jack/libtelnet-haskell +license: GPL-3.0-or-later +license-file: COPYING +author: Jack Kelly +maintainer: jack@jackkelly.name +copyright: (c) 2017-2019 Jack Kelly +category: Network +build-type: Simple +extra-source-files: COPYING, ChangeLog.md, README.md +tested-with: GHC == 8.6.3 + , GHC == 8.6.1 + , GHC == 8.4.4 + , GHC == 8.4.3 + , GHC == 8.4.2 + , GHC == 8.2.2 + , GHC == 8.0.2 + +flag example + description: Build the example program + default: False + manual: True + +library + hs-source-dirs: src + exposed-modules: Network.Telnet.LibTelnet + , Network.Telnet.LibTelnet.Ffi + , Network.Telnet.LibTelnet.Iac + , Network.Telnet.LibTelnet.Options + , Network.Telnet.LibTelnet.Types + ghc-options: -Wall + build-depends: base >= 4.7 && < 5 + , bytestring >= 0.10.6.0 && < 0.11 + pkgconfig-depends: libtelnet + default-language: Haskell2010 + +executable example + hs-source-dirs: example + main-is: Main.hs + ghc-options: -Wall -threaded -rtsopts -with-rtsopts=-N + if flag(example) + buildable: True + build-depends: base + , libtelnet + , bytestring >= 0.10.6.0 && < 0.11 + , network-simple >= 0.4 && < 0.5 + , monad-loops >= 0.4.3 && < 0.5 + else + buildable: False + default-language: Haskell2010 + +source-repository head + type: git + location: https://git.sr.ht/~jack/libtelnet-haskell diff --git a/src/Network/Telnet/LibTelnet.hs b/src/Network/Telnet/LibTelnet.hs new file mode 100644 --- /dev/null +++ b/src/Network/Telnet/LibTelnet.hs @@ -0,0 +1,388 @@ +{-# LANGUAGE DeriveDataTypeable #-} +{-# LANGUAGE DeriveGeneric #-} +{-# LANGUAGE FlexibleInstances #-} +{-# LANGUAGE MultiWayIf #-} +{-# LANGUAGE RecordWildCards #-} +{-# LANGUAGE TypeSynonymInstances #-} + +-- | Getting Started: +-- +-- 1. Skim +-- , +-- as these bindings follow the C library's conventions quite closely. +-- +-- 2. Write an event-handling function, of type 'EventHandler'. +-- +-- 3. When you accept a new connection, create a 'Telnet' state +-- tracker for it using 'telnetInit'. Options and flags are defined in +-- the same way as the C library; option constants are exported from +-- "Network.Telnet.LibTelnet.Options". +-- +-- 4. When you receive data (probably on a socket), tell 'Telnet' +-- about it using 'telnetRecv'. +-- +-- 5. To send data, negotiate options, &c., use 'telnetSend', +-- 'telnetIac', &c. +-- +-- 6. IAC (Interpret-As-Command) codes are exported from +-- "Network.Telnet.LibTelnet.Iac". + +module Network.Telnet.LibTelnet + ( telnetInit + , OptionSpec(..) + , T.Flag + , T.flagProxy + + -- * Telnet pointers + , Telnet + , TelnetPtr + , HasTelnetPtr(..) + + -- * Event handling + , EventHandler + , Event(..) + , Err(..) + , IsInfo(..) + , Var(..) + + -- * Simple operations + , telnetRecv + , telnetSend + + -- * Generic telnet option negotiation + , telnetIac + , telnetNegotiate + , telnetSubnegotiation + + -- * Compression + , telnetBeginCompress2 + + -- * @NEW-ENVIRON@ functions + , telnetNewEnvironSend + , telnetNewEnviron + + -- * @TERMINAL-TYPE@ functions + , telnetTTypeSend + , telnetTTypeIs + + -- * ZMP + , telnetSendZmp + + -- * MSSP + , telnetSendMssp + + -- * Exceptions + , T.TelnetException(..) + ) where + +import qualified Network.Telnet.LibTelnet.Ffi as F +import qualified Network.Telnet.LibTelnet.Iac as I +import Network.Telnet.LibTelnet.Options (Option(..), optMSSP) +import qualified Network.Telnet.LibTelnet.Types as T + +import Control.Exception (throw, throwIO) +import Data.ByteString (ByteString) +import qualified Data.ByteString.Char8 as B8 +import Data.Foldable (traverse_) +import Data.Function (on) +import Data.List (groupBy) +import Data.Monoid ((<>)) +import Data.Typeable (Typeable) +import Foreign (ForeignPtr, Ptr, peek, peekArray, withForeignPtr) +import Foreign.C.String (castCUCharToChar) +import GHC.Generics (Generic) + +-- | Create a @libtelnet@ state tracker. +telnetInit :: [OptionSpec] -> [T.Flag] -> EventHandler -> IO Telnet +telnetInit options flags handler = + F.telnetInit options' (convertEventHandler handler) flags + where + options' = map f options + f (OptionSpec opt us him) = + let us' = if us then I.iacWill else I.iacWont + him' = if him then I.iacDo else I.iacDont + in T.TelnetTeloptT (fromIntegral $ unOption opt) us' him' + +-- | Configures which options you want to support. The triple's +-- elements are: option code, support on our end (corresponds to +-- @WILL/WONT@), support on their end (corresponds to @DO/DONT@). +data OptionSpec = OptionSpec + { _code :: Option -- ^ Option code + , _us :: Bool -- ^ Supported on our end? (@WILL@/@WONT@) + , _him :: Bool -- ^ Can other end use it with us? (@DO@/@DONT@) + } deriving (Eq, Generic, Show, Typeable) + +-- | Garbage-collected pointer to the @libtelnet@ state tracker. Your +-- program should hang on to this. +type Telnet = ForeignPtr T.TelnetT + +-- | Raw pointer to the @libtelnet@ state tracker. This is passed to +-- the event handlers and you shouldn't see it elsewhere. +type TelnetPtr = Ptr T.TelnetT + +-- | The pointer you get back from 'telnetInit' is a 'ForeignPtr' +-- because it carries around its finalizers, but the pointer that gets +-- passed into your 'EventHandler' is a bare 'Ptr' because it's being +-- passed in from C. This class lets us generalise across both types. +class HasTelnetPtr t where + withTelnetPtr :: t -> (TelnetPtr -> IO a) -> IO a + +-- | Unwrap with 'withForeignPtr'. +instance HasTelnetPtr Telnet where + withTelnetPtr = withForeignPtr + +-- | No unwrapping needed. +instance HasTelnetPtr TelnetPtr where + withTelnetPtr t f = f t + +-- | Type of the event handler callback. +type EventHandler = TelnetPtr -> Event -> IO () + +-- | Structure provided to the event handler. +data Event + = Received ByteString + -- ^ Data received; you should pass it to the application. + | Send ByteString + -- ^ Data you need to send out to the socket. + | Warning Err + -- ^ Something has gone wrong inside of libtelnet but + -- recovery is (likely) possible. + | Error Err + -- ^ Something has gone wrong. The application should + -- immediately close the connection. + | Iac I.Iac -- ^ Telnet interpret-as-command. + | Will Option -- ^ Other end offers an option. + | Wont Option -- ^ Other end cannot support option. + | Do Option -- ^ Other end asked you to support option. + | Dont Option -- ^ Other end asked you to stop using option. + | Subnegotiation Option ByteString + -- ^ Subnegotiation received for some option. + | Zmp [ByteString] + -- ^ + -- message + | TerminalTypeSend + -- ^ @TERMINAL-TYPE SEND@ message + -- . + -- The server wants to know about your terminal-type. + | TerminalTypeIs ByteString + -- ^ @TERMINAL-TYPE IS@ message + -- . + -- The client has told us a terminal-type. + | Compress Bool + -- ^ Would the client like + -- ? + | EnvironSend [(Var, ByteString)] + -- ^ Request to send the following environment variables, per + -- and + -- . + | Environ IsInfo [(Var, ByteString, ByteString)] + -- ^ @ENVIRON@/@NEW-ENVIRON@ options, per + -- and + -- . + -- Keys come before values in the tuples. + | Mssp [(ByteString, [ByteString])] + -- ^ + -- List is @(key, values)@. + deriving (Eq, Generic, Show, Typeable) + +-- | Error message from @libtelnet@. +data Err = Err + { _file :: ByteString + , _func :: ByteString + , _msg :: ByteString + , _line :: Int + , _errcode :: T.TelnetErrorT + } + deriving (Eq, Generic, Show, Typeable) + +-- | Were the 'Environ' fields sent as part of a @NEW-ENVIRON IS@ +-- message, or part of a @NEW-ENVIRON INFO@ message? +data IsInfo = Is | Info deriving (Eq, Show) + +-- | In an 'Environ' message, are the vars being sent as @VAR@s or @USERVAR@s? +data Var = Var | UserVar deriving (Eq, Show) + +-- | Tell the state tracker about received data. +telnetRecv :: HasTelnetPtr t => t -> ByteString -> IO () +telnetRecv t bs = withTelnetPtr t $ \telnetP -> F.telnetRecv telnetP bs + +-- | Send non-command data. +telnetSend :: HasTelnetPtr t => t -> ByteString -> IO () +telnetSend t bs = withTelnetPtr t $ \telnetP -> F.telnetSend telnetP bs + +-- | Send a telnet command. +telnetIac :: HasTelnetPtr t => t -> I.Iac -> IO () +telnetIac t c = withTelnetPtr t $ \telnetP -> F.cTelnetIac telnetP c + +-- | Send a negotiation command. +telnetNegotiate :: HasTelnetPtr t => t -> I.Iac -> Option -> IO () +telnetNegotiate t cmd opt = withTelnetPtr t $ + \telnetP -> F.cTelnetNegotiate telnetP cmd opt + +-- | Send a subnegotiation. +telnetSubnegotiation :: HasTelnetPtr t => t -> Option -> ByteString -> IO () +telnetSubnegotiation t opt bs = withTelnetPtr t $ + \telnetP -> F.telnetSubnegotiation telnetP opt bs + +-- | Begin sending compressed data, using the @COMPRESS2@ option. The +-- server should call this command in response to a @'Compress' True@ +-- event. +telnetBeginCompress2 :: HasTelnetPtr t => t -> IO () +telnetBeginCompress2 t = withTelnetPtr t $ + \telnetP -> F.cTelnetBeginCompress2 telnetP + +-- | Ask the client to send us these environment variables. +telnetNewEnvironSend :: HasTelnetPtr t => t -> [(Var, ByteString)] -> IO () +telnetNewEnvironSend t vars = withTelnetPtr t $ + \telnetP -> do + let sendVar (var, str) = B8.useAsCString str (sendVal $ varToEvar var) + sendVal = F.cTelnetNewEnvironValue telnetP + + F.cTelnetBeginNewEnviron telnetP T.eCmdSend + traverse_ sendVar vars + F.cTelnetIac telnetP I.iacSE + +-- | Tell the server about our environment variables. +telnetNewEnviron + :: HasTelnetPtr t => t -> IsInfo -> [(Var, ByteString, ByteString)] -> IO () +telnetNewEnviron t isInfo vars = withTelnetPtr t $ + \telnetP -> do + let isInfo' = case isInfo of + Is -> T.eCmdIs + Info -> T.eCmdInfo + + sendVar (var, name, value) = + B8.useAsCString name (sendVal $ varToEvar var) *> + B8.useAsCString value (sendVal T.eValue) + + sendVal = F.cTelnetNewEnvironValue telnetP + + F.cTelnetBeginNewEnviron telnetP isInfo' + traverse_ sendVar vars + F.cTelnetIac telnetP I.iacSE + +-- | Ask the client to give us a terminal type. +telnetTTypeSend :: HasTelnetPtr t => t -> IO () +telnetTTypeSend t = withTelnetPtr t F.cTelnetTTypeSend + +-- | Tell the server a terminal type. +telnetTTypeIs :: HasTelnetPtr t => t -> ByteString -> IO () +telnetTTypeIs t bs = withTelnetPtr t $ + \telnetP -> B8.useAsCString bs (F.cTelnetTTypeIs telnetP) + +-- | Send a ZMP command. +telnetSendZmp :: HasTelnetPtr t => t -> [ByteString] -> IO () +telnetSendZmp t cmd = withTelnetPtr t $ + \telnetP -> F.telnetSendZmp telnetP cmd + +-- | Send an MSSP status. +telnetSendMssp :: HasTelnetPtr t => t -> [(ByteString, [ByteString])] -> IO () +telnetSendMssp t stats = telnetSubnegotiation t optMSSP stats' where + stats' = foldMap pack stats + pack (var, vals) = msspVar <> var <> foldMap (msspVal <>) vals + + msspVar = B8.singleton . castCUCharToChar . T.unMsspVar $ T.msspVar + msspVal = B8.singleton . castCUCharToChar . T.unMsspVar $ T.msspVal + +-- | Convert the event structure from the FFI into something nicer. +convertEventT :: T.EventT -> IO Event +convertEventT (T.Data (str, len)) = + Received <$> B8.packCStringLen (str, fromIntegral len) + +convertEventT (T.Send (str, len)) = + Send <$> B8.packCStringLen (str, fromIntegral len) + +convertEventT (T.Warning e) = Warning <$> packErrorT e + +convertEventT (T.Error e) = Error <$> packErrorT e + +convertEventT (T.Command cmd) = pure $ Iac cmd + +convertEventT (T.Will opt) = pure $ Will opt + +convertEventT (T.Wont opt) = pure $ Wont opt + +convertEventT (T.Do opt) = pure $ Do opt + +convertEventT (T.Dont opt) = pure $ Dont opt + +convertEventT (T.Subnegotiation opt (str, len)) = + Subnegotiation opt <$> B8.packCStringLen (str, fromIntegral len) + +convertEventT (T.Zmp (argv, argc)) = + Zmp <$> (traverse B8.packCString =<< peekArray (fromIntegral argc) argv) + +convertEventT (T.TerminalType cmd name) + | cmd == T.tCmdIs = TerminalTypeIs <$> B8.packCString name + | cmd == T.tCmdSend = pure TerminalTypeSend + | otherwise = throwIO $ T.UnexpectedTerminalTypeCmd cmd + +convertEventT (T.Compress ok) = pure . Compress $ ok == 1 + +convertEventT (T.Environ cmd (values, size)) = do + environs <- peekArray (fromIntegral size) values + if | cmd == T.eCmdSend -> do + vars <- traverse packVar environs + pure $ EnvironSend vars + | cmd `elem` [T.eCmdIs, T.eCmdInfo] -> do + isInfo <- if | cmd == T.eCmdIs -> pure Is + | cmd == T.eCmdInfo -> pure Info + | otherwise -> throwIO $ T.UnexpectedEnvironCmd cmd + vars <- traverse packVarVal environs + pure $ Environ isInfo vars + | otherwise -> throwIO $ T.UnexpectedEnvironCmd cmd + +convertEventT (T.Mssp (values, size)) = do + environs <- peekArray (fromIntegral size) values + packed <- traverse packVarVal' environs + + let grouped = groupBy ((==) `on` fst) packed + + extract [] = error "Grouping should have made lists nonempty!" + extract ((var, val):vals) = (var, val : map snd vals) + + pure . Mssp $ map extract grouped + +varToEvar :: Var -> T.EVar +varToEvar Var = T.eVar +varToEvar UserVar = T.eUserVar + +eVarToVar :: T.EVar -> Var +eVarToVar var + | var == T.eVar = Var + | var == T.eUserVar = UserVar + | otherwise = throw $ T.UnexpectedEnvironVar var + +-- | Convert 'T.ErrorT' into managed strings. +packErrorT :: T.ErrorT -> IO Err +packErrorT T.ErrorT{..} = do + file <- B8.packCString _file + func <- B8.packCString _func + msg <- B8.packCString _msg + pure $ Err file func msg (fromIntegral _line) _errcode + +-- | Convert 'T.TelnetEnvironT' representing a request for an +-- environment var. +packVar :: T.TelnetEnvironT -> IO (Var, ByteString) +packVar T.TelnetEnvironT{..} = do + var <- B8.packCString _var + pure (eVarToVar _type, var) + +-- | Convert 'T.TelnetEnvironT' representing a message about an +-- environment var's value. +packVarVal :: T.TelnetEnvironT -> IO (Var, ByteString, ByteString) +packVarVal T.TelnetEnvironT{..} = do + var <- B8.packCString _var + value <- B8.packCString _value + pure (eVarToVar _type, var, value) + +-- | Convert 'T.TelnetEnvironT' representing an MSSP message (i.e., +-- type is undefined). +packVarVal' :: T.TelnetEnvironT -> IO (ByteString, ByteString) +packVarVal' T.TelnetEnvironT{..} = + (,) <$> B8.packCString _var <*> B8.packCString _value + +-- | Turn your event handler into one that the FFI can handle. +convertEventHandler :: EventHandler -> F.TelnetEventHandlerT +convertEventHandler f telnetP eventP _ = + peek eventP >>= convertEventT >>= f telnetP diff --git a/src/Network/Telnet/LibTelnet/Ffi.hsc b/src/Network/Telnet/LibTelnet/Ffi.hsc new file mode 100644 --- /dev/null +++ b/src/Network/Telnet/LibTelnet/Ffi.hsc @@ -0,0 +1,166 @@ +-- | FFI binding to @libtelnet@. + +module Network.Telnet.LibTelnet.Ffi where + +import Network.Telnet.LibTelnet.Iac (Iac(..), iacNull) +import Network.Telnet.LibTelnet.Options (Option(..)) +import qualified Network.Telnet.LibTelnet.Types as T + +import Control.Exception (throwIO) +import Control.Monad (when) +import Data.ByteString (ByteString) +import qualified Data.ByteString as B +import Data.List (genericLength) +import Foreign hiding (newForeignPtr) +import Foreign.C (CSize(..), CString, CUChar(..)) +import Foreign.Concurrent (newForeignPtr) + +#include + +-- | Wrap 'cTelnetInit'. +telnetInit + :: [T.TelnetTeloptT] + -> TelnetEventHandlerT + -> [T.Flag] + -> IO (ForeignPtr T.TelnetT) +telnetInit options handler flags = do + optionsA <- newArray0 (T.TelnetTeloptT (-1) iacNull iacNull) options + handlerP <- wrapEventHandler handler + let flagsC = foldr ((.|.) . T.unFlag) 0 flags + telnet <- cTelnetInit optionsA handlerP flagsC nullPtr + when (telnet == nullPtr) $ throwIO T.NullTelnetPtr + + newForeignPtr telnet $ do + cTelnetFree telnet + freeHaskellFunPtr handlerP + free optionsA + +-- | C function @telnet_init@. +foreign import ccall "libtelnet.h telnet_init" + cTelnetInit + :: Ptr T.TelnetTeloptT -- ^ @const telnet_telopt_t *telopts@ + -> FunPtr TelnetEventHandlerT -- ^ @telnet_event_handler_t eh@ + -> CUChar -- ^ @unsigned char flags@ + -> Ptr () -- ^ @void *user_data@ + -> IO (Ptr T.TelnetT) + +-- | C function @telnet_free@. +foreign import ccall "libtelnet.h telnet_free" + cTelnetFree :: Ptr T.TelnetT -> IO () + +-- | Represents @telnet_event_handler_t@. +type TelnetEventHandlerT = Ptr T.TelnetT -> Ptr T.EventT -> Ptr () -> IO () + +-- | Wrap an 'TelnetEventHandlerT' to pass to C code. +foreign import ccall "wrapper" + wrapEventHandler :: TelnetEventHandlerT -> IO (FunPtr TelnetEventHandlerT) + +-- | Wrap 'cTelnetRecv'. +telnetRecv :: Ptr T.TelnetT -> ByteString -> IO () +telnetRecv telnetP bs = B.useAsCStringLen bs $ + \(buffer, size) -> cTelnetRecv telnetP buffer $ fromIntegral size + +-- | C function @telnet_recv@. +foreign import ccall "libtelnet.h telnet_recv" + cTelnetRecv + :: Ptr T.TelnetT -- ^ @telnet_t *telnet@ + -> CString -- ^ @const char *buffer@ + -> CSize -- ^ @size_t size@ + -> IO () + +-- | C function @telnet_iac@. +foreign import ccall "libtelnet.h telnet_iac" + cTelnetIac + :: Ptr T.TelnetT -- ^ @telnet_t *telnet@ + -> Iac -- ^ @unsigned char cmd@ + -> IO () + +-- | C function @telnet_negotiate@. +foreign import ccall "libtelnet.h telnet_negotiate" + cTelnetNegotiate + :: Ptr T.TelnetT -- ^ @telnet_t *telnet@ + -> Iac -- ^ unsigned char cmd + -> Option -- ^ unsigned char opt + -> IO () + +-- | Wrap 'cTelnetSend'. +telnetSend :: Ptr T.TelnetT -> ByteString -> IO () +telnetSend telnetP bs = B.useAsCStringLen bs $ + \(buffer, size) -> cTelnetSend telnetP buffer $ fromIntegral size + +-- | C function @telnet_send@. +foreign import ccall "libtelnet.h telnet_send" + cTelnetSend + :: Ptr T.TelnetT -- ^ @telnet_t *telnet@ + -> CString -- ^ @const char *buffer@ + -> CSize -- ^ @size_t size@ + -> IO () + +-- | Wrap 'cTelnetSubnegotiation'. +telnetSubnegotiation :: Ptr T.TelnetT -> Option -> ByteString -> IO () +telnetSubnegotiation telnetP opt bs = B.useAsCStringLen bs $ + \(buffer, size) -> + cTelnetSubnegotiation telnetP opt buffer $ fromIntegral size + +-- | C function @telnet_subnegotiation@. +foreign import ccall "libtelnet.h telnet_subnegotiation" + cTelnetSubnegotiation + :: Ptr T.TelnetT -- ^ @telnet_t *telnet@ + -> Option -- ^ @unsigned char telopt@ + -> CString -- ^ @const char *buffer@ + -> CSize -- ^ @size_t size@ + -> IO () + +-- | C function @telnet_begin_compress2@. +foreign import ccall "libtelnet.h telnet_begin_compress2" + cTelnetBeginCompress2 + :: Ptr T.TelnetT -- ^ @telnet_t *telnet@ + -> IO () + +-- | C function @telnet_begin_newenviron@. +foreign import ccall "libtelnet.h telnet_begin_newenviron" + cTelnetBeginNewEnviron + :: Ptr T.TelnetT -- ^ @telnet_t *telnet@ + -> T.ECmd -- ^ @unsigned char type@ + -> IO () + +-- | C function @telnet_newenviron_value@. +foreign import ccall "libtelnet.h telnet_newenviron_value" + cTelnetNewEnvironValue + :: Ptr T.TelnetT -- ^ @telnet_t *telnet@ + -> T.EVar -- ^ @unsigned char type@ + -> CString -- ^ @const char *string@ + -> IO () + +-- | C function @telnet_ttype_send@. +foreign import ccall "libtelnet.h telnet_ttype_send" + cTelnetTTypeSend + :: Ptr T.TelnetT -- ^ @telnet_t *telnet@ + -> IO () + +-- | C function @telnet_ttype_is@. +foreign import ccall "libtelnet.h telnet_ttype_is" + cTelnetTTypeIs + :: Ptr T.TelnetT -- ^ @telnet_t *telnet@ + -> CString -- ^ @const char *ttype@ + -> IO () + +-- | Wrap 'cTelnetSendZmp'. +telnetSendZmp :: Ptr T.TelnetT -> [ByteString] -> IO () +telnetSendZmp telnetP cmd = useAsCStrings cmd $ + \cCmd -> cTelnetSendZmp telnetP (genericLength cmd) cCmd + +-- | C function @telnet_send_zmp@. +foreign import ccall "libtelnet.h telnet_send_zmp" + cTelnetSendZmp + :: Ptr T.TelnetT -- ^ @telnet_t *telnet@ + -> CSize -- ^ @size_t argc@ + -> Ptr CString -- ^ @const char **argv@ + -> IO () + +-- | Collect '[ByteString]' into a temporary array of strings in a +-- 'Ptr CString', to passing to C functions. +useAsCStrings :: [ByteString] -> (Ptr CString -> IO a) -> IO a +useAsCStrings list f = go list [] where + go [] css = withArray (reverse css) f + go (bs:bss) css = B.useAsCString bs $ \cs -> go bss (cs:css) diff --git a/src/Network/Telnet/LibTelnet/Iac.hsc b/src/Network/Telnet/LibTelnet/Iac.hsc new file mode 100644 --- /dev/null +++ b/src/Network/Telnet/LibTelnet/Iac.hsc @@ -0,0 +1,59 @@ +{-# LANGUAGE GeneralizedNewtypeDeriving #-} + +-- | Telnet interpret-as-command (IAC) codes. + +module Network.Telnet.LibTelnet.Iac + ( Iac(..) + , iacNull + , iacIac + , iacDont + , iacDo + , iacWont + , iacWill + , iacSB + , iacGA + , iacEL + , iacEC + , iacAYT + , iacAO + , iacIP + , iacBreak + , iacDM + , iacNOP + , iacSE + , iacEOR + , iacAbort + , iacSusp + , iacEOF + ) where + +import Foreign (Storable) +import Foreign.C (CUChar) + +#include + +-- | Wrapper for telnet commands and special values. +newtype Iac = Iac { unIac :: CUChar } deriving (Eq, Show, Storable) +#{enum Iac, Iac + , iacNull = 0 + , iacIac = TELNET_IAC + , iacDont = TELNET_DONT + , iacDo = TELNET_DO + , iacWont = TELNET_WONT + , iacWill = TELNET_WILL + , iacSB = TELNET_SB + , iacGA = TELNET_GA + , iacEL = TELNET_EL + , iacEC = TELNET_EC + , iacAYT = TELNET_AYT + , iacAO = TELNET_AO + , iacIP = TELNET_IP + , iacBreak = TELNET_BREAK + , iacDM = TELNET_DM + , iacNOP = TELNET_NOP + , iacSE = TELNET_SE + , iacEOR = TELNET_EOR + , iacAbort = TELNET_ABORT + , iacSusp = TELNET_SUSP + , iacEOF = TELNET_EOF + } diff --git a/src/Network/Telnet/LibTelnet/Options.hsc b/src/Network/Telnet/LibTelnet/Options.hsc new file mode 100644 --- /dev/null +++ b/src/Network/Telnet/LibTelnet/Options.hsc @@ -0,0 +1,107 @@ +{-# LANGUAGE GeneralizedNewtypeDeriving #-} + +-- | Telnet option codes. + +module Network.Telnet.LibTelnet.Options + ( Option(..) + , optBinary + , optEcho + , optRCP + , optSGA + , optNAMS + , optStatus + , optTM + , optRCTE + , optNAOL + , optNAOP + , optNAOCRD + , optNAOHTS + , optNAOHTD + , optNAOFFD + , optNAOVTS + , optNAOVTD + , optNAOLFD + , optXASCII + , optLogout + , optBM + , optDET + , optSUPDUP + , optSUPDUPOutput + , optSNDLOC + , optTType + , optEOR + , optTUID + , optOUTMRK + , optTTYLOC + , opt3270Regime + , optX3Pad + , optNAWS + , optTSpeed + , optLFlow + , optLineMode + , optXDISPLOC + , optEnviron + , optAuthentication + , optEncrypt + , optNewEnviron + , optMSSP + , optCompress2 + , optZMP + , optEXOPL + , optMCCP2 + ) where + +import Foreign (Storable) +import Foreign.C (CUChar) + +#include + +-- | Wrapper for telnet option codes. +newtype Option = Option { unOption :: CUChar } deriving (Eq, Show, Storable) +#{enum Option, Option + , optBinary = TELNET_TELOPT_BINARY + , optEcho = TELNET_TELOPT_ECHO + , optRCP = TELNET_TELOPT_RCP + , optSGA = TELNET_TELOPT_SGA + , optNAMS = TELNET_TELOPT_NAMS + , optStatus = TELNET_TELOPT_STATUS + , optTM = TELNET_TELOPT_TM + , optRCTE = TELNET_TELOPT_RCTE + , optNAOL = TELNET_TELOPT_NAOL + , optNAOP = TELNET_TELOPT_NAOP + , optNAOCRD = TELNET_TELOPT_NAOCRD + , optNAOHTS = TELNET_TELOPT_NAOHTS + , optNAOHTD = TELNET_TELOPT_NAOHTD + , optNAOFFD = TELNET_TELOPT_NAOFFD + , optNAOVTS = TELNET_TELOPT_NAOVTS + , optNAOVTD = TELNET_TELOPT_NAOVTD + , optNAOLFD = TELNET_TELOPT_NAOLFD + , optXASCII = TELNET_TELOPT_XASCII + , optLogout = TELNET_TELOPT_LOGOUT + , optBM = TELNET_TELOPT_BM + , optDET = TELNET_TELOPT_DET + , optSUPDUP = TELNET_TELOPT_SUPDUP + , optSUPDUPOutput = TELNET_TELOPT_SUPDUPOUTPUT + , optSNDLOC = TELNET_TELOPT_SNDLOC + , optTType = TELNET_TELOPT_TTYPE + , optEOR = TELNET_TELOPT_EOR + , optTUID = TELNET_TELOPT_TUID + , optOUTMRK = TELNET_TELOPT_OUTMRK + , optTTYLOC = TELNET_TELOPT_TTYLOC + , opt3270Regime = TELNET_TELOPT_3270REGIME + , optX3Pad = TELNET_TELOPT_X3PAD + , optNAWS = TELNET_TELOPT_NAWS + , optTSpeed = TELNET_TELOPT_TSPEED + , optLFlow = TELNET_TELOPT_LFLOW + , optLineMode = TELNET_TELOPT_LINEMODE + , optXDISPLOC = TELNET_TELOPT_XDISPLOC + , optEnviron = TELNET_TELOPT_ENVIRON + , optAuthentication = TELNET_TELOPT_AUTHENTICATION + , optEncrypt = TELNET_TELOPT_ENCRYPT + , optNewEnviron = TELNET_TELOPT_NEW_ENVIRON + , optMSSP = TELNET_TELOPT_MSSP + , optCompress2 = TELNET_TELOPT_COMPRESS2 + , optZMP = TELNET_TELOPT_ZMP + , optEXOPL = TELNET_TELOPT_EXOPL + , optMCCP2 = TELNET_TELOPT_MCCP2 + } diff --git a/src/Network/Telnet/LibTelnet/Types.hsc b/src/Network/Telnet/LibTelnet/Types.hsc new file mode 100644 --- /dev/null +++ b/src/Network/Telnet/LibTelnet/Types.hsc @@ -0,0 +1,331 @@ +{-# LANGUAGE DeriveDataTypeable #-} +{-# LANGUAGE DeriveGeneric #-} +{-# LANGUAGE GeneralizedNewtypeDeriving #-} +{-# LANGUAGE MultiWayIf #-} +{-# LANGUAGE RecordWildCards #-} + +-- | Wrapping of @libtelnet@ types. + +module Network.Telnet.LibTelnet.Types where + +import Network.Telnet.LibTelnet.Iac +import Network.Telnet.LibTelnet.Options + +import Control.Exception (Exception, throwIO) +import Data.Typeable (Typeable) +import Foreign +import Foreign.C +import GHC.Generics (Generic) + +#include + +-- | Uninhabited type for pointer safety (@telnet_t@). +data TelnetT + +-- | Exceptions thrown by the binding, for when something has gone +-- seriously wrong. Errors detected by @libtelnet@ are not thrown but +-- instead are passed to the event handler. +data TelnetException + = NullTelnetPtr + | UnexpectedEventType TelnetEventTypeT + | UnexpectedEnvironCmd ECmd + | UnexpectedEnvironVar EVar + | UnexpectedTerminalTypeCmd TCmd + deriving (Eq, Generic, Show, Typeable) + +instance Exception TelnetException + +-- | Flags for @telnet_init@. +newtype Flag = Flag { unFlag :: CUChar } +#{enum Flag, Flag + , flagProxy = TELNET_FLAG_PROXY + } + +-- | Wraps @telnet_telopt_t@. +data TelnetTeloptT = TelnetTeloptT + { _telopt :: CShort -- ^ option value + , _us :: Iac -- ^ option supported on server + , _him :: Iac -- ^ allow clients to use the option? + } + +instance Storable TelnetTeloptT where + sizeOf _ = (#size telnet_telopt_t) + alignment _ = (#alignment telnet_telopt_t) + + peek p = do + telopt <- (#peek telnet_telopt_t, telopt) p + us <- (#peek telnet_telopt_t, us) p + him <- (#peek telnet_telopt_t, him) p + + pure $ TelnetTeloptT telopt us him + + poke p TelnetTeloptT{..} = do + (#poke telnet_telopt_t, telopt) p _telopt + (#poke telnet_telopt_t, us) p _us + (#poke telnet_telopt_t, him) p _him + +-- | Wraps @telnet_event_t@. +data EventT + = Data (CString, CSize) -- ^ 'eventData' + | Send (CString, CSize) -- ^ 'eventSend' + | Warning ErrorT -- ^ 'eventWarning' + | Error ErrorT -- ^ 'eventError' + | Command Iac -- ^ 'eventIac' + | Will Option -- ^ 'eventWill' + | Wont Option -- ^ 'eventWont' + | Do Option -- ^ 'eventDo' + | Dont Option -- ^ 'eventDont' + | Subnegotiation Option (CString, CSize) -- ^ 'eventSubnegotiation' + | Zmp (Ptr CString, CSize) -- ^ 'eventZmp' + | TerminalType TCmd CString -- ^ 'eventTType' + | Compress CUChar -- ^ 'eventCompress' + | Environ ECmd (Ptr TelnetEnvironT, CSize) -- ^ 'eventEnviron' + | Mssp (Ptr TelnetEnvironT, CSize) -- ^ 'eventMssp' + +instance Storable EventT where + sizeOf _ = (#size telnet_event_t) + alignment _ = (#alignment telnet_event_t) + + peek p = do + eType <- (#peek telnet_event_t, type) p + if | eType `elem` [eventData, eventSend] -> do + ctor <- if | eType == eventData -> pure Data + | eType == eventSend -> pure Send + | otherwise -> throwIO $ UnexpectedEventType eType + buffer <- (#peek telnet_event_t, data.buffer) p + size <- (#peek telnet_event_t, data.size) p + pure $ ctor (buffer, size) + + | eType `elem` [eventWarning, eventError] -> do + ctor <- if | eType == eventWarning -> pure Warning + | eType == eventError -> pure Error + | otherwise -> throwIO $ UnexpectedEventType eType + file <- (#peek telnet_event_t, error.file) p + func <- (#peek telnet_event_t, error.func) p + msg <- (#peek telnet_event_t, error.msg) p + line <- (#peek telnet_event_t, error.line) p + errcode <- (#peek telnet_event_t, error.errcode) p + + pure . ctor $ ErrorT file func msg line errcode + + | eType == eventIac -> + Command <$> (#peek telnet_event_t, iac.cmd) p + + | eType `elem` [eventWill, eventWont, eventDo, eventDont] -> do + ctor <- if | eType == eventWill -> pure Will + | eType == eventWont -> pure Wont + | eType == eventDo -> pure Do + | eType == eventDont -> pure Dont + | otherwise -> throwIO $ UnexpectedEventType eType + ctor <$> (#peek telnet_event_t, neg.telopt) p + + | eType == eventSubnegotiation -> do + telopt <- (#peek telnet_event_t, sub.telopt) p + buffer <- (#peek telnet_event_t, sub.buffer) p + size <- (#peek telnet_event_t, sub.size) p + + pure $ Subnegotiation telopt (buffer, size) + + | eType == eventZmp -> do + argc <- (#peek telnet_event_t, zmp.argc) p + argv <- (#peek telnet_event_t, zmp.argv) p + + pure $ Zmp (argv, argc) + + | eType == eventTType -> do + cmd <- (#peek telnet_event_t, ttype.cmd) p + name <- (#peek telnet_event_t, ttype.name) p + + pure $ TerminalType cmd name + + | eType == eventCompress -> + Compress <$> (#peek telnet_event_t, compress.state) p + + | eType == eventEnviron -> do + cmd <- (#peek telnet_event_t, environ.cmd) p + values <- (#peek telnet_event_t, environ.values) p + size <- (#peek telnet_event_t, environ.size) p + + pure $ Environ cmd (values, size) + + | eType == eventMssp -> do + values <- (#peek telnet_event_t, mssp.values) p + size <- (#peek telnet_event_t, mssp.size) p + + pure $ Mssp (values, size) + + | otherwise -> throwIO $ UnexpectedEventType eType + + poke p (Data (buffer, size)) = do + (#poke telnet_event_t, type) p eventData + (#poke telnet_event_t, data.buffer) p buffer + (#poke telnet_event_t, data.size) p size + + poke p (Send (buffer, size)) = do + (#poke telnet_event_t, type) p eventSend + (#poke telnet_event_t, data.buffer) p buffer + (#poke telnet_event_t, data.size) p size + + poke p (Warning ErrorT{..}) = do + (#poke telnet_event_t, type) p eventWarning + (#poke telnet_event_t, error.file) p _file + (#poke telnet_event_t, error.func) p _func + (#poke telnet_event_t, error.msg) p _msg + (#poke telnet_event_t, error.line) p _line + (#poke telnet_event_t, error.errcode) p _errcode + + poke p (Error ErrorT{..}) = do + (#poke telnet_event_t, type) p eventError + (#poke telnet_event_t, error.file) p _file + (#poke telnet_event_t, error.func) p _func + (#poke telnet_event_t, error.msg) p _msg + (#poke telnet_event_t, error.line) p _line + (#poke telnet_event_t, error.errcode) p _errcode + + poke p (Command cmd) = do + (#poke telnet_event_t, type) p eventIac + (#poke telnet_event_t, iac.cmd) p cmd + + poke p (Will opt) = do + (#poke telnet_event_t, type) p eventWill + (#poke telnet_event_t, neg.telopt) p opt + + poke p (Wont opt) = do + (#poke telnet_event_t, type) p eventWont + (#poke telnet_event_t, neg.telopt) p opt + + poke p (Do opt) = do + (#poke telnet_event_t, type) p eventDo + (#poke telnet_event_t, neg.telopt) p opt + + poke p (Dont opt) = do + (#poke telnet_event_t, type) p eventDont + (#poke telnet_event_t, neg.telopt) p opt + + poke p (Subnegotiation opt (buffer, size)) = do + (#poke telnet_event_t, type) p eventSubnegotiation + (#poke telnet_event_t, sub.telopt) p opt + (#poke telnet_event_t, sub.buffer) p buffer + (#poke telnet_event_t, sub.size) p size + + poke p (Zmp (argv, argc)) = do + (#poke telnet_event_t, type) p eventZmp + (#poke telnet_event_t, zmp.argv) p argv + (#poke telnet_event_t, zmp.argc) p argc + + poke p (TerminalType cmd name) = do + (#poke telnet_event_t, type) p eventTType + (#poke telnet_event_t, ttype.cmd) p cmd + (#poke telnet_event_t, ttype.name) p name + + poke p (Compress state) = do + (#poke telnet_event_t, type) p eventCompress + (#poke telnet_event_t, compress.state) p state + + poke p (Environ cmd (values, size)) = do + (#poke telnet_event_t, type) p eventEnviron + (#poke telnet_event_t, environ.cmd) p cmd + (#poke telnet_event_t, environ.values) p values + (#poke telnet_event_t, environ.size) p size + + poke p (Mssp (values, size)) = do + (#poke telnet_event_t, type) p eventMssp + (#poke telnet_event_t, mssp.values) p values + (#poke telnet_event_t, mssp.size) p size + +-- | Constants from @telnet_event_type_t@. +newtype TelnetEventTypeT = TelnetEventTypeT { unTelnetEventTypeT :: CInt } + deriving (Eq, Show, Storable) +#{enum TelnetEventTypeT, TelnetEventTypeT + , eventData = TELNET_EV_DATA + , eventSend = TELNET_EV_SEND + , eventIac = TELNET_EV_IAC + , eventWill = TELNET_EV_WILL + , eventWont = TELNET_EV_WONT + , eventDo = TELNET_EV_DO + , eventDont = TELNET_EV_DONT + , eventSubnegotiation = TELNET_EV_SUBNEGOTIATION + , eventCompress = TELNET_EV_COMPRESS + , eventZmp = TELNET_EV_ZMP + , eventTType = TELNET_EV_TTYPE + , eventEnviron = TELNET_EV_ENVIRON + , eventMssp = TELNET_EV_MSSP + , eventWarning = TELNET_EV_WARNING + , eventError = TELNET_EV_ERROR + } + +-- | Data in 'Warning' and 'Error' events, modeled after @struct +-- error_t@ inside @telnet_event_t@. +data ErrorT = ErrorT + { _file :: CString + , _func :: CString + , _msg :: CString + , _line :: CInt + , _errcode :: TelnetErrorT + } + +-- | Constants from @telnet_error_t@. +newtype TelnetErrorT = TelnetErrorT { unTelnetErrorT :: CInt } + deriving (Eq, Show, Storable) +#{enum TelnetErrorT, TelnetErrorT + , errOK = TELNET_EOK + , errBadVal = TELNET_EBADVAL + , errNoMem = TELNET_ENOMEM + , errOverflow = TELNET_EOVERFLOW + , errProtocol = TELNET_EPROTOCOL + , errCompress = TELNET_ECOMPRESS + } + +-- | Constants for @TERMINAL-TYPE@ commands. +newtype TCmd = TCmd { unTCmd :: CUChar } deriving (Eq, Show, Storable) +#{enum TCmd, TCmd + , tCmdIs = TELNET_TTYPE_IS + , tCmdSend = TELNET_TTYPE_SEND + } + +-- | Constants for @ENVIRON@/@NEW-ENVIRON@ commands. +newtype ECmd = ECmd { unECmd :: CUChar } deriving (Eq, Show, Storable) +#{enum ECmd, ECmd + , eCmdIs = TELNET_ENVIRON_IS + , eCmdSend = TELNET_ENVIRON_SEND + , eCmdInfo = TELNET_ENVIRON_INFO + } + +-- | Constants for @ENVIRON@/@NEW-ENVIRON@ variables. +newtype EVar = EVar { unEvar :: CUChar } deriving (Eq, Show, Storable) +#{enum EVar, EVar + , eVar = TELNET_ENVIRON_VAR + , eValue = TELNET_ENVIRON_VALUE + , eUserVar = TELNET_ENVIRON_USERVAR + } + +-- | Constants for MSSP. +newtype MsspVar = MsspVar { unMsspVar :: CUChar } deriving (Eq, Show, Storable) +#{enum MsspVar, MsspVar + , msspVar = TELNET_MSSP_VAR + , msspVal = TELNET_MSSP_VAL + } + +-- | @ENVIRONMENT@\/@NEW-ENVIRONMENT@\/@MSSP@ messages, wrapping +-- @telnet_environ_t@. +data TelnetEnvironT = TelnetEnvironT + { _type :: EVar -- ^ @unsigned char type@ + , _var :: CString -- ^ @char *var@ + , _value :: CString -- ^ @char *value@ + } + +instance Storable TelnetEnvironT where + sizeOf _ = (#size struct telnet_environ_t) + alignment _ = (#alignment struct telnet_environ_t) + + peek p = do + type_ <- (#peek struct telnet_environ_t, type) p + var <- (#peek struct telnet_environ_t, var) p + value <- (#peek struct telnet_environ_t, value) p + + pure $ TelnetEnvironT type_ var value + + poke p TelnetEnvironT{..} = do + (#poke struct telnet_environ_t, type) p _type + (#poke struct telnet_environ_t, var) p _var + (#poke struct telnet_environ_t, value) p _value