From 16a17a496ce84c5866af45a66f181ce193a9376f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Manuel=20P=C3=A9gouri=C3=A9-Gonnard?= <mpg@elzevir.fr>
Date: Tue, 30 Jun 2015 11:20:22 +0200
Subject: [PATCH] Fix net_accept() for UDP sockets on Windows

On Windows, recvfrom() returns an error code if the destination buffer is too
small to hold the next datagram.
---
 library/net.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/library/net.c b/library/net.c
index bfa7072d1..b3928799d 100644
--- a/library/net.c
+++ b/library/net.c
@@ -309,6 +309,15 @@ int mbedtls_net_accept( int bind_fd, int *client_fd,
 
         ret = recvfrom( bind_fd, buf, sizeof( buf ), MSG_PEEK,
                         (struct sockaddr *) &client_addr, &n );
+
+#if defined(_WIN32)
+        if( ret == SOCKET_ERROR &&
+            WSAGetLastError() == WSAEMSGSIZE )
+        {
+            /* We know buf is too small, thanks, just peeking here */
+            ret = 0;
+        }
+#endif
     }
 
     if( ret < 0 )