Fix fd range for select on Windows
Fix mbedtls_net_poll() and mbedtls_net_recv_timeout() often failing with
MBEDTLS_ERR_NET_POLL_FAILED on Windows: they were testing that the file
descriptor is in range for fd_set, but on Windows socket descriptors are not
limited to a small range. Fixes #4465.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/library/net_sockets.c b/library/net_sockets.c
index 746ed2a..5fbe1f7 100644
--- a/library/net_sockets.c
+++ b/library/net_sockets.c
@@ -145,12 +145,17 @@
if( fd < 0 )
return( MBEDTLS_ERR_NET_INVALID_CONTEXT );
+#if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
+ !defined(EFI32)
+ (void) for_select;
+#else
/* A limitation of select() is that it only works with file descriptors
* that are strictly less than FD_SETSIZE. This is a limitation of the
* fd_set type. Error out early, because attempting to call FD_SET on a
* large file descriptor is a buffer overflow on typical platforms. */
if( for_select && fd >= FD_SETSIZE )
return( MBEDTLS_ERR_NET_POLL_FAILED );
+#endif
return( 0 );
}