Fix bitsize of some msghdr and cmsghdr fields on Linux

These fields are size_t on Linux, so using CInt on LP64 only
accesses 32 bits of the total 64.  This is especially noticable on big
endian, where the lower 32 bits of the number are written to the upper
32 bits of the field.  Also use #type socklen_t instead of CUInt/CInt
where applicable, since POSIX does not specify the size of this type.

Network/Socket/Posix/CmsgHdr.hsc

@@ -22,7 +22,11 @@ import Network.Socket.Posix.MsgHdr
 import Network.Socket.Types
 
 data CmsgHdr = CmsgHdr {
-    cmsgHdrLen   :: !CInt
+#ifdef __linux__
+    cmsgHdrLen   :: !CSize
+#else
+    cmsgHdrLen   :: !(#type socklen_t)
+#endif
   , cmsgHdrLevel :: !CInt
   , cmsgHdrType  :: !CInt
   } deriving (Eq, Show)
@@ -61,7 +65,7 @@ withCmsgs cmsgs0 action
 
 toCmsgHdr :: Cmsg -> Ptr CmsgHdr -> IO ()
 toCmsgHdr (Cmsg (CmsgId lvl typ) (PS fptr off len)) ctrlPtr = do
-    poke ctrlPtr $ CmsgHdr (c_cmsg_len (fromIntegral len)) lvl typ
+    poke ctrlPtr $ CmsgHdr (fromIntegral $ c_cmsg_len (fromIntegral len)) lvl typ
     withForeignPtr fptr $ \src0 -> do
         let src = src0 `plusPtr` off
         dst <- c_cmsg_data ctrlPtr
@@ -96,7 +100,7 @@ foreign import ccall unsafe "cmsg_data"
   c_cmsg_data :: Ptr CmsgHdr -> IO (Ptr Word8)
 
 foreign import ccall unsafe "cmsg_space"
-  c_cmsg_space :: CInt -> CInt
+  c_cmsg_space :: CSize -> CSize
 
 foreign import ccall unsafe "cmsg_len"
-  c_cmsg_len :: CInt -> CInt
+  c_cmsg_len :: CSize -> CSize

Network/Socket/Posix/MsgHdr.hsc

@@ -15,11 +15,19 @@ import Network.Socket.Posix.IOVec (IOVec)
 
 data MsgHdr sa = MsgHdr
     { msgName    :: !(Ptr sa)
-    , msgNameLen :: !CUInt
+    , msgNameLen :: !(#type socklen_t)
     , msgIov     :: !(Ptr IOVec)
+#ifdef __linux__
     , msgIovLen  :: !CSize
+#else
+    , msgIovLen  :: !CInt
+#endif
     , msgCtrl    :: !(Ptr Word8)
-    , msgCtrlLen :: !CInt
+#ifdef __linux__
+    , msgCtrlLen :: !CSize
+#else
+    , msgCtrlLen :: !(#type socklen_t)
+#endif
     , msgFlags   :: !CInt
     }
 

cbits/cmsg.c

@@ -87,11 +87,11 @@ unsigned char *cmsg_data(struct cmsghdr *cmsg) {
   return (CMSG_DATA(cmsg));
 }
 
-int cmsg_space(int l) {
+size_t cmsg_space(size_t l) {
   return (CMSG_SPACE(l));
 }
 
-int cmsg_len(int l) {
+size_t cmsg_len(size_t l) {
   return (CMSG_LEN(l));
 }
 #endif /* _WIN32 */

include/HsNet.h

@@ -126,11 +126,11 @@ cmsg_nxthdr(struct msghdr *mhdr, struct cmsghdr *cmsg);
 extern unsigned char *
 cmsg_data(struct cmsghdr *cmsg);
 
-extern int
-cmsg_space(int l);
+extern size_t
+cmsg_space(size_t l);
 
-extern int
-cmsg_len(int l);
+extern size_t
+cmsg_len(size_t l);
 #endif /* _WIN32 */
 
 INLINE int