diff options
| -rw-r--r-- | System/Posix/User.hsc | 33 |
1 files changed, 32 insertions, 1 deletions
diff --git a/System/Posix/User.hsc b/System/Posix/User.hsc index 965a0d0..ed5adfb 100644 --- a/System/Posix/User.hsc +++ b/System/Posix/User.hsc @@ -47,6 +47,10 @@ import Foreign import Foreign.C import System.Posix.Internals ( CGroup, CPasswd ) +#if !defined(HAVE_GETPWNAM_R) || !defined(HAVE_GETPWUID_R) +import Control.Concurrent.MVar ( newMVar, withMVar ) +#endif + -- ----------------------------------------------------------------------------- -- user environemnt @@ -168,7 +172,7 @@ grBufSize :: Int grBufSize = fromIntegral $ unsafePerformIO $ c_sysconf (#const _SC_GETGR_R_SIZE_MAX) #else -grBufSize = 1024 -- just assume some value +grBufSize = 2048 -- just assume some value (1024 is too small on OpenBSD) #endif #endif @@ -192,6 +196,16 @@ data UserEntry = userShell :: String } +-- +-- getpwuid and getpwnam leave results in a static object. Subsequent +-- calls modify the same object, which isn't threadsafe. We attempt to +-- mitigate this issue, on platforms that don't provide the safe _r versions +-- +#if !defined(HAVE_GETPWNAM_R) || !defined(HAVE_GETPWUID_R) +lock = unsafePerformIO $ newMVar () +{-# NOINLINE lock #-} +#endif + getUserEntryForID :: UserID -> IO UserEntry #ifdef HAVE_GETPWUID_R getUserEntryForID uid = do @@ -205,6 +219,14 @@ getUserEntryForID uid = do foreign import ccall unsafe "getpwuid_r" c_getpwuid_r :: CUid -> Ptr CPasswd -> CString -> CSize -> Ptr (Ptr CPasswd) -> IO CInt +#elif HAVE_GETPWUID +getUserEntryForID uid = do + withMVar lock $ \_ -> do + ppw <- throwErrnoIfNull "getUserEntryForID" $ c_getpwuid uid + unpackUserEntry ppw + +foreign import ccall unsafe "getpwuid" + c_getpwuid :: CUid -> IO (Ptr CPasswd) #else getUserEntryForID = error "System.Posix.User.getUserEntryForID: not supported" #endif @@ -223,6 +245,15 @@ getUserEntryForName name = do foreign import ccall unsafe "getpwnam_r" c_getpwnam_r :: CString -> Ptr CPasswd -> CString -> CSize -> Ptr (Ptr CPasswd) -> IO CInt +#elif HAVE_GETPWNAM +getUserEntryForName name = do + withCString name $ \ pstr -> do + withMVar lock $ \_ -> do + ppw <- throwErrnoIfNull "getUserEntryForName" $ c_getpwnam pstr + unpackUserEntry ppw + +foreign import ccall unsafe "getpwnam" + c_getpwnam :: CString -> IO (Ptr CPasswd) #else getUserEntryForName = error "System.Posix.User.getUserEntryForName: not supported" #endif |