net: Add a "connection" interface which can abstract ipv4 and ipv6.

Change-Id: I4110dc5aaebf6e696ea41809c96b233944274cdd
diff --git a/src/net/connection.h b/src/net/connection.h
new file mode 100644
index 0000000..d063523
--- /dev/null
+++ b/src/net/connection.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#ifndef __NET_CONNECTION_H__
+#define __NET_CONNECTION_H__
+
+#include <stddef.h>
+#include <stdint.h>
+
+typedef struct NetConOps {
+	int (*bind)(struct NetConOps *me, uint16_t port);
+	int (*incoming)(struct NetConOps *me, size_t *size);
+	int (*send)(struct NetConOps *me, const void *data, size_t len);
+	int (*receive)(struct NetConOps *me, void *data, size_t *len,
+		       size_t max_len);
+	int (*close)(struct NetConOps *me);
+} NetConOps;
+
+static inline int netcon_bind(NetConOps *con, uint16_t port)
+{
+	return con->bind(con, port);
+}
+
+static inline int netcon_incoming(NetConOps *con, size_t *size)
+{
+	return con->incoming(con, size);
+}
+
+static inline int netcon_send(NetConOps *con, const void *data, size_t len)
+{
+	return con->send(con, data, len);
+}
+
+static inline int netcon_receive(NetConOps *con, void *data, size_t *len,
+			  size_t max_len)
+{
+	return con->receive(con, data, len, max_len);
+}
+
+static inline int netcon_close(NetConOps *con)
+{
+	return con->close(con);
+}
+
+#endif /* __NET_CONNECTION_H__ */