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                 // Spec says Version is first, but stupid bit ordering
  16                 unsigned HeaderLength:  4;      // in 4-byte chunks
  17                 unsigned Version:       4;      // = 4
  18         } __attribute__((packed));
  19         Uint8   DiffServices;   // Differentiated Services
  20         Uint16  TotalLength;
  21         Uint16  Identifcation;
  22
  23         struct {
  24                 unsigned Reserved:      1;
  25                 unsigned DontFragment:  1;
  26                 unsigned MoreFragments: 1;
  27                 unsigned FragOffLow:    5;
  28         } __attribute__((packed));
  29         Uint8   FragOffHi;      // Number of 8-byte blocks from the original start
  30
  31         Uint8   TTL;    // Max number of hops, effectively
  32         Uint8   Protocol;
  33         Uint16  HeaderChecksum; // One's Complement Sum of the entire header must equal zero
  34
  35         tIPv4   Source;
  36         tIPv4   Destination;
  37
  38         Uint8   Options[];
  39 } __attribute__((packed));
  40
  41 #define IP4PROT_ICMP    1
  42 #define IP4PROT_TCP     6
  43 #define IP4PROT_UDP     17
  44
  45 #define IPV4_ETHERNET_ID        0x0800
  46
  47 // === FUNCTIONS ===
  48 extern int      IPv4_RegisterCallback(int ID, tIPCallback Callback);
  49 extern Uint16   IPv4_Checksum(const void *Buf, size_t Length);
  50 extern int      IPv4_SendPacket(tInterface *Iface, tIPv4 Address, int Protocol, int ID, int Length, const void *Data);
  51
  52 #endif