Fix bitsize of cmsgHdrLen and msgCtrlLen on Posix

These fields are size_t, 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.

Network/Socket/Posix/CmsgHdr.hsc

@@ -22,7 +22,7 @@ import Network.Socket.Posix.MsgHdr
 import Network.Socket.Types
 
 data CmsgHdr = CmsgHdr {
-    cmsgHdrLen   :: !CInt
+    cmsgHdrLen   :: !CSize
   , cmsgHdrLevel :: !CInt
   , cmsgHdrType  :: !CInt
   } deriving (Eq, Show)
@@ -96,7 +96,7 @@ 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

@@ -19,7 +19,7 @@ data MsgHdr sa = MsgHdr
     , msgIov     :: !(Ptr IOVec)
     , msgIovLen  :: !CSize
     , msgCtrl    :: !(Ptr Word8)
-    , msgCtrlLen :: !CInt
+    , msgCtrlLen :: !CSize
     , 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