--- gvpe/src/device.h	2003/10/14 17:01:07	1.8
+++ gvpe/src/device.h	2005/03/03 16:54:34	1.17
@@ -1,7 +1,10 @@
 /*
     device.h -- generic header for device.c
+    Copyright (C) 2003-2005 Marc Lehmann <gvpe@schmorp.de>
  
-    This program is free software; you can redistribute it and/or modify
+    This file is part of GVPE.
+
+    GVPE 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.
@@ -12,7 +15,7 @@
     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
+    along with gvpe; if not, write to the Free Software
     Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
 
@@ -24,11 +27,13 @@
 #include "gettext.h"
 
 #include "global.h"
+#include "util.h"
 
 struct net_packet {
   u32 len; // actually u16, but padding...
 
   u8 &operator[] (u16 offset) const;
+  u8 *at (u16 offset) const;
 
   void unshift_hdr (u16 hdrsize)
     {
@@ -48,7 +53,23 @@
       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
@@ -70,7 +91,11 @@
   return ((data_packet *)this)->data_[offset];
 }
 
-typedef u8 mac[6];
+inline 
+u8 *net_packet::at (u16 offset) const
+{
+  return &((*this)[offset]);
+}
 
 struct tap_packet : net_packet {
   mac dst;
@@ -78,7 +103,7 @@
   u8 data[MAXSIZE - 12];
 };
 
-struct tap_device_base {
+struct tap_device {
   int fd;
 
   // network interface name or identifier