* fhandler_socket.cc (fhandler_socket::ioctl): Handle the different

	ideas of u_long between Winsock and Cygwin applications on x86_64.
	Add long comment.

1 files changed, 23 insertions, 0 deletions

diff --git a/winsup/cygwin/fhandler_socket.cc b/winsup/cygwin/fhandler_socket.cc
index 1fbabd88d..d4602be8a 100644
--- a/winsup/cygwin/fhandler_socket.cc
+++ b/winsup/cygwin/fhandler_socket.cc
@@ -2093,7 +2093,22 @@ fhandler_socket::ioctl (unsigned int cmd, void *p)
 	  }
 	break;
       }
+    /* From this point on we handle only ioctl commands which are understood by
+       Winsock.  However, we have a problem, which is, the different size of
+       u_long in Windows and 64 bit Cygwin.  This affects the definitions of
+       FIOASYNC, etc, because they are defined in terms of sizeof(u_long).
+       So we have to use case labels which are independent of the sizeof
+       u_long.  Since we're redefining u_long at the start of this file to
+       matching Winsock's idea of u_long, we can use the real definitions in
+       calls to Windows.  In theory we also have to make sure to convert the
+       different ideas of u_long between the application and Winsock, but
+       fortunately, the parameters defined as u_long pointers are on Linux
+       and BSD systems defined as int pointer, so the applications will
+       use a type of the expected size.  Hopefully. */
     case FIOASYNC:
+#ifdef __x86_64__
+    case _IOW('f', 125, unsigned long):
+#endif
       res = WSAAsyncSelect (get_socket (), winmsg, WM_ASYNCIO,
 	      *(int *) p ? ASYNC_MASK : 0);
       syscall_printf ("Async I/O on socket %s",
@@ -2104,6 +2119,9 @@ fhandler_socket::ioctl (unsigned int cmd, void *p)
 	WSAEventSelect (get_socket (), wsock_evt, EVENT_MASK);
       break;
     case FIONREAD:
+#ifdef __x86_64__
+    case _IOR('f', 127, unsigned long):
+#endif
       res = ioctlsocket (get_socket (), FIONREAD, (u_long *) p);
       if (res == SOCKET_ERROR)
 	set_winsock_errno ();
@@ -2111,6 +2129,11 @@ fhandler_socket::ioctl (unsigned int cmd, void *p)
     default:
       /* Sockets are always non-blocking internally.  So we just note the
 	 state here. */
+#ifdef __x86_64__
+      /* Convert the different idea of u_long in the definition of cmd. */
+      if (((cmd >> 16) & IOCPARM_MASK) == sizeof (unsigned long))
+      	cmd = (cmd & ~(IOCPARM_MASK << 16)) | (sizeof (u_long) << 16);
+#endif
       if (cmd == FIONBIO)
 	{
 	  syscall_printf ("socket is now %sblocking",