task #7506: added NAT support

src/include/ipv4/lwip/ip_nat.h

@@ -0,0 +1,51 @@
+/***************************************************************************
+ * Template - A brief description for this module.
+ * Copyright (c) 2008 Christian Walter, © Embedded Solutions, Vienna 2006.
+ *
+ * $Id: ip_nat.h,v 1.1 2010/05/05 19:34:23 goldsimon Exp $
+ ***************************************************************************/
+
+#ifndef __LWIP_NAT_H__
+#define __LWIP_NAT_H__
+
+#include "lwip/err.h"
+#include "lwip/ip_addr.h"
+#include "lwip/opt.h"
+
+#if IP_NAT
+
+/** Timer interval at which to call ip_nat_tmr() */
+#define LWIP_NAT_TMR_INTERVAL_SEC        5
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+struct netif;
+struct pbuf;
+
+typedef struct ip_nat_entry
+{
+  ip_addr_t    source_net;
+  ip_addr_t    source_netmask;
+  ip_addr_t    dest_net;
+  ip_addr_t    dest_netmask;
+  struct netif *out_if;
+  struct netif *in_if;
+} ip_nat_entry_t;
+
+void  ip_nat_init(void);
+void  ip_nat_tmr(void);
+u8_t  ip_nat_input(struct pbuf *p);
+u8_t  ip_nat_out(struct pbuf *p);
+
+err_t ip_nat_add(const ip_nat_entry_t *new_entry);
+void  ip_nat_remove(const ip_nat_entry_t *remove_entry);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* IP_NAT */
+
+#endif /* __LWIP_NAT_H__ */

src/include/lwip/opt.h

@@ -466,6 +466,11 @@
 #define IP_FORWARD                      0
 #endif
 
+/** IP_NAT==1: Enables network address translation code */
+#ifndef IP_NAT
+#define IP_NAT                          0
+#endif
+
 /**
  * IP_OPTIONS_ALLOWED: Defines the behavior for IP options.
  *      IP_OPTIONS_ALLOWED==0: All packets with IP options are dropped.