--- gvpe/src/device.h	2003/10/14 03:22:09	1.6
+++ gvpe/src/device.h	2003/10/16 02:28:36	1.10
@@ -19,7 +19,7 @@
 #ifndef VPE_DEVICE_H__
 #define VPE_DEVICE_H__
 
-#define IFNAMESIZE 256
+#define IFNAMESIZE 256 // be conservative
 
 #include "gettext.h"
 
@@ -48,7 +48,23 @@
       memcpy (&((*this)[0]), &(pkt[0]), len);
     }
 
-  bool is_arp ()
+  bool is_ipv4 () const
+    {
+      return (*this)[12] == 0x08 && (*this)[13] == 0x00 // IP
+          && ((*this)[14] & 0xf0) == 0x40;              // IPv4
+    }
+
+  u32 &ipv4_src () const
+    {
+      return *(u32 *)&(*this)[26];
+    }
+  
+  u32 &ipv4_dst () const
+    {
+      return *(u32 *)&(*this)[30];
+    }
+  
+  bool is_arp () const
     {
       return (*this)[12] == 0x08 && (*this)[13] == 0x06		// 0806 protocol
           && (*this)[14] == 0x00 && (*this)[15] == 0x01		// 0001 hw_format
@@ -81,7 +97,7 @@
 struct tap_device {
   int fd;
 
-  // linux tuntap
+  // network interface name or identifier
   char ifrname[IFNAMESIZE + 1];
 
   char *device;
@@ -89,6 +105,9 @@
   tap_device ();
   ~tap_device ();
 
+  //bool open ();
+  //void close ();
+
   const char *interface () { return ifrname; }
   const char *info ();
 
@@ -96,5 +115,7 @@
   void send (tap_packet *pkt);
 };
 
+//extern tap_device *tap_device ();
+
 #endif