--- /dev/null
+++ b/lwip-contrib/ports/unix/include/libvdeplug_dyn.h
@@ -0,0 +1,144 @@
+/*
+ * libvdeplug - A library to connect to a VDE Switch.
+ * dynamic loading version (requires libdl).
+ *
+ * Copyright (C) 2006,2007 Renzo Davoli, University of Bologna
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation version 2.1 of the License, or (at
+ * your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+/* Use this include file when you need to write an application that can
+ * benefit from vde when available.
+ * Linking libvdeplug to your programs you force your application users
+ * to have the library installed (otherway the dynamic linker complies
+ * and the program does not start).
+ *
+ *
+ * usage:
+ * define a struct vdepluglib variable;
+ * eg:
+ *         struct vdepluglib vdeplug;
+ *
+ * test the availability of the library and load it:
+ *
+ *         libvdeplug_dynopen(vdeplug);
+ * if vdeplug.dl_handle is not NULL the library is ready otherwise it is
+ * not available in the target system.
+ *
+ * if libvdeplug does exist the library function can be called
+ * in this way:
+ *         vdeplug.vde_open(....)
+ *         vdeplug.vde_read(....)
+ *         vdeplug.vde_open(....)
+ *         vdeplug.vde_recv(....)
+ *         vdeplug.vde_send(....)
+ *         vdeplug.vde_datafd(....)
+ *         vdeplug.vde_ctlfd(....)
+ *         vdeplug.vde_close(....)
+ * libvdeplug_dynclose(vdeplug) can be used to deallocate the dynamic library
+ * when needed.
+ *************************************************/
+
+#ifndef _VDEDYNLIB_H
+#define _VDEDYNLIB_H
+#include <sys/types.h>
+#include <dlfcn.h>
+#define LIBVDEPLUG_INTERFACE_VERSION 1
+
+struct vdeconn;
+typedef struct vdeconn VDECONN;
+
+struct vdestream;
+typedef struct vdestream VDESTREAM;
+
+/* Open a VDE connection.
+ * vde_open_options:
+ *   port: connect to a specific port of the switch (0=any)
+ *   group: change the ownership of the communication port to a specific group
+ *        (NULL=no change)
+ *   mode: set communication port mode (if 0 standard socket mode applies)
+ */
+struct vde_open_args {
+	int port;
+	char *group;
+	mode_t mode;
+};
+
+/* vde_open args:
+ *   vde_switch: switch id (path)
+ *   descr: description (it will appear in the port description on the switch)
+ */
+#define vde_open(vde_switch,descr,open_args) \
+	vde_open_real((vde_switch),(descr),LIBVDEPLUG_INTERFACE_VERSION,(open_args))
+
+struct vdepluglib {
+	void *dl_handle;
+	VDECONN * (*vde_open_real)(const char *vde_switch,char *descr,int interface_version, struct vde_open_args *open_args);
+	ssize_t (* vde_recv)(VDECONN *conn,void *buf,size_t len,int flags);
+	ssize_t (* vde_send)(VDECONN *conn,const void *buf,size_t len,int flags);
+	int (* vde_datafd)(VDECONN *conn);
+	int (* vde_ctlfd)(VDECONN *conn);
+	int (* vde_close)(VDECONN *conn);
+	VDESTREAM * (* vdestream_open)(void *opaque, int fdout,
+			ssize_t (* frecv)(void *opaque, void *buf, size_t count),
+			void (* ferr)(void *opaque, int type, char *format, ...)
+			);
+	ssize_t (* vdestream_send)(VDESTREAM *vdestream, const void *buf, size_t len);
+	void (* vdestream_recv)(VDESTREAM *vdestream, unsigned char *buf, size_t len);
+	void (* vdestream_close)(VDESTREAM *vdestream);
+};
+
+typedef VDECONN * (* VDE_OPEN_REAL_T)(const char *vde_switch,char *descr,int interface_version, struct vde_open_args *open_args);
+typedef ssize_t (* VDE_RECV_T)(VDECONN *conn,void *buf,size_t len,int flags);
+typedef ssize_t (* VDE_SEND_T)(VDECONN *conn,const void *buf,size_t len,int flags);
+typedef int (* VDE_INT_FUN)(VDECONN *conn);
+typedef VDESTREAM * (* VDESTREAM_OPEN_T)(void *opaque, int fdout,
+			ssize_t (* frecv)(void *opaque, void *buf, size_t count),
+			void (* ferr)(void *opaque, int type, char *format, ...)
+			);
+typedef ssize_t (* VDESTREAM_SEND_T)(VDESTREAM *vdestream, const void *buf, size_t len);
+typedef void (* VDESTREAM_RECV_T)(VDESTREAM *vdestream, unsigned char *buf, size_t len);
+typedef void (* VDESTREAM_CLOSE_T)(VDESTREAM *vdestream);
+
+#define libvdeplug_dynopen(x) ({ \
+	(x).dl_handle=dlopen("libvdeplug.so",RTLD_NOW); \
+	if ((x).dl_handle) { \
+		(x).vde_open_real=(VDE_OPEN_REAL_T) dlsym((x).dl_handle,"vde_open_real"); \
+		(x).vde_recv=(VDE_RECV_T) dlsym((x).dl_handle,"vde_recv"); \
+		(x).vde_send=(VDE_SEND_T) dlsym((x).dl_handle,"vde_send"); \
+		(x).vde_datafd=(VDE_INT_FUN) dlsym((x).dl_handle,"vde_datafd"); \
+		(x).vde_ctlfd=(VDE_INT_FUN) dlsym((x).dl_handle,"vde_ctlfd"); \
+		(x).vde_close=(VDE_INT_FUN) dlsym((x).dl_handle,"vde_close"); \
+		(x).vdestream_open=(VDESTREAM_OPEN_T) dlsym((x).dl_handle,"vdestream_open"); \
+		(x).vdestream_send=(VDESTREAM_SEND_T) dlsym((x).dl_handle,"vdestream_send"); \
+		(x).vdestream_recv=(VDESTREAM_RECV_T) dlsym((x).dl_handle,"vdestream_recv"); \
+		(x).vdestream_close=(VDESTREAM_CLOSE_T) dlsym((x).dl_handle,"vdestream_close"); \
+		} else { \
+		(x).vde_open_real=NULL; \
+		(x).vde_send= NULL; \
+		(x).vde_recv= NULL; \
+		(x).vde_datafd= (x).vde_ctlfd= (x).vde_close= NULL; \
+		(x).vdestream_open= NULL; \
+		(x).vdestream_send= NULL; \
+		(x).vdestream_recv= NULL; \
+		(x).vdestream_close= NULL; \
+		}\
+		})
+
+#define libvdeplug_dynclose(x) ({ \
+		dlclose((x).dl_handle); \
+		})
+
+#endif