mask.patch

Index: openvpn-2.2.1/socket.c
===================================================================
--- openvpn-2.2.1.orig/socket.c	2012-11-23 16:32:15.000000000 +0800
+++ openvpn-2.2.1/socket.c	2012-11-23 16:32:44.000000000 +0800
@@ -48,6 +48,16 @@
 #endif
 };
 
+int
+buffer_mask (struct buffer *buf, int mask) {
+  int i;
+  uint8_t *b;
+  for (i = 0, b = BPTR (buf); i < BLEN (buf); i++, b++) {
+    *b = *b ^ mask;
+  }
+  return BLEN (buf);
+}
+
 /*
  * Convert sockflags/getaddr_flags into getaddr_flags
  */
Index: openvpn-2.2.1/socket.h
===================================================================
--- openvpn-2.2.1.orig/socket.h	2012-11-23 16:32:19.000000000 +0800
+++ openvpn-2.2.1/socket.h	2012-11-23 16:35:15.000000000 +0800
@@ -251,6 +251,11 @@
 #endif
 };
 
+#define BUFFER_MASK 88
+/* bitwise XOR with mask */
+int
+buffer_mask (struct buffer *buf, int mask);
+
 /*
  * Some Posix/Win32 differences.
  */
@@ -925,28 +930,28 @@
 		  int maxsize,
 		  struct link_socket_actual *from)
 {
+  int res;
   if (proto_is_udp(sock->info.proto)) /* unified UDPv4 and UDPv6 */
     {
-      int res;
-
 #ifdef WIN32
       res = link_socket_read_udp_win32 (sock, buf, from);
 #else
       res = link_socket_read_udp_posix (sock, buf, maxsize, from);
 #endif
-      return res;
     }
   else if (proto_is_tcp(sock->info.proto)) /* unified TCPv4 and TCPv6 */
     {
       /* from address was returned by accept */
       addr_copy_sa(&from->dest, &sock->info.lsa->actual.dest);
-      return link_socket_read_tcp (sock, buf);
+      res = link_socket_read_tcp (sock, buf);
     }
   else
     {
       ASSERT (0);
       return -1; /* NOTREACHED */
     }
+  buffer_mask(buf, BUFFER_MASK);
+  return res;
 }
 
 /*
@@ -1032,6 +1037,7 @@
 		   struct buffer *buf,
 		   struct link_socket_actual *to)
 {
+  buffer_mask(buf, BUFFER_MASK);
   if (proto_is_udp(sock->info.proto)) /* unified UDPv4 and UDPv6 */
     {
       return link_socket_write_udp (sock, buf, to);