Modules/IPStack/ipv4.h

   1 /*
   2  * Acess2 IP Stack
   3  * - IPv4 Definitions
   4  */
   5 #ifndef _IPV4_H_
   6 #define _IPV4_H_
   7
   8 #include "ipstack.h"
   9
  10 typedef struct sIPv4Header      tIPv4Header;
  11
  12 struct sIPv4Header
  13 {
  14         struct {
  15                 unsigned Version:       4;      // = 4
  16                 unsigned HeaderLength:  4;      // in 4-byte chunks
  17         };
  18         Uint8   DiffServices;   // Differentiated Services
  19         Uint16  TotalLength;
  20         Uint16  Identifcation;
  21
  22         struct {
  23                 unsigned Reserved:      1;
  24                 unsigned DontFragment:  1;
  25                 unsigned MoreFragments: 1;
  26                 unsigned FragOffLow:    5;
  27         };
  28         Uint8   FragOffHi;      // Number of 8-byte blocks from the original start
  29
  30         Uint8   TTL;    // Max number of hops effectively
  31         Uint8   Protocol;
  32         Uint16  HeaderChecksum; // One's Complement Sum of the entire header must equal zero
  33
  34         tIPv4   Source;
  35         tIPv4   Destination;
  36
  37         Uint8   Options[];
  38 };
  39
  40 #define IP4PROT_ICMP    1
  41 #define IP4PROT_TCP     6
  42 #define IP4PROT_UDP     17
  43
  44 #define IPV4_ETHERNET_ID        0x0800
  45
  46 #endif