arp.h

完整的TCP/IP源代码,绝对好用

/**************************************************************************
*                                                                          
* FILENAME                                      VERSION                            
*                                                                                  
*      ARP.H                                      4.5                              
*                                                                                  
* DESCRIPTION                                                              
*                                                                          
*      This include file will handle ARP .        
*                                                                          
* DATA STRUCTURES                                                          
*                                                                          
*       ARP_ENTRY
*       ARP_LAYER
*       ARP_RESOLVE_ENTRY
*       ARP_RESOLVE_LIST
*       ARP_MAC_HEADER                            
*
* DEPENDENCIES                                                             
*                                                                          
*      No other file dependencies                                          
*                                                                          
****************************************************************************/
//#include "ethernet.h"

#ifndef ARP_H
#define ARP_H
/***************************************************************************/
#define DADDLEN     6    // Define the length of the ethernet header in bytes.
#define IP_ADDR_LEN        4 //Ddefine the length of the IP address


/***********************************************************************/
/*  ARP cache
*   Data structure for saving low-level information until needed
*/
typedef struct ARP_ENTRY_STRUCT
{
    UINT8  arp_ip_addr[4];            /* the IP # in question                       */
    UINT8     arp_flags;              /* is this a gateway?                         */
                                    /* Is this a valid entry.  For gateways an    */
                                    /* entry is created before the HW addr is     */
                                    /* known.  This flag indicates when the HW    */
                                    /* is resolved.                               */
    UINT32  arp_time;               /* time information  (live time 20 minute)                         */
    UINT8   arp_mac_addr[DADDLEN];  /* hardware address for this IP address       */
    UINT8   pad[2];
} ARP_ENTRY;

#define ARP_UP          0x1         /* Is this entry valid.                       */
#define ARP_GATEWAY     0x2         /* Is this entry for a gateway.               */
#define ARP_PERMANENT   0x4         /* Is this entry permanent.                   */

/* This structure defines an ARP packet. */
typedef struct ARP_LAYER_STRUCT
{
    UINT16  arp_hrd;                /* hardware type, Ethernet = 1                */
    UINT16  arp_pro;                /* protocol type to resolve for               */
    UINT8   arp_hln;                /* byte length of hardware addr = 6 for ETNET */
    UINT8   arp_pln;                /* byte length of protocol = 4 for IP         */
    UINT16  arp_op;                 /* opcode, request = 1, reply = 2, RARP = 3,4 */
    UINT8   arp_sha[6];       /* Source Hardware Address                    */
    UINT8   arp_spa[4];   /* Source protocol address.                   */
    UINT8   arp_tha[6];       /* Target Hardware Address                    */
    UINT8   arp_tpa[4];   /* Target protocol address.                   */
/*
*   the final four fields (contained in 'rest') are:
*     sender hardware address:   sha       hln bytes
*     sender protocol address:   spa       pln bytes
*     target hardware address:   tha       hln bytes
*     target protocol address:   tpa       pln bytes
*/
} ARP_LAYER;


/*************************************************************************/
/*  Dave Plummer's  Address Resolution Protocol (ARP) (RFC-826) and 
*   Finlayson, Mann, Mogul and Theimer's Reverse ARP packets.
*
*   Note that the 2 byte ints are byte-swapped.  The protocols calls for
*   in-order bytes, and the PC is lo-hi ordered.
*   
*/
#define RARPR   0x0004              /*  RARP reply, from host, needs swap        */
#define RARPQ   0x0003              /*  RARP request, needs swapping             */
#define ARPREP  0x0002              /*  reply, byte swapped when used            */
#define ARPREQ  0x0001              /*  request, byte-swapped when used          */
#define ARPPRO  0x0800              /*  IP protocol, needs swapping              */

#define     RARP_MAX_ATTEMPTS   5

/* ARP_RESOLVE_STRUCT is used to keep track the resolution of MAC layer
   addresses.
 */

/* This structure is used by ARP to build the MAC layer header in before 
   passing it to the MAC layer send routine. */
//***********************************
#define wait_buffer_num   1
// the buffer save the ip waiting send to ethernet.
typedef struct IP_buffer_struct
{
     UINT8  tipnum[4];
     UINT8  thardware[6];
     UINT16 time;
     UINT8  send_packet[1400];
     UINT16 send_packet_len;
     UINT8  flag;        // 0 is blank ,1 is full
}IP_buffer;




/* Function Prototypes */
void ARP_Init();
UINT8  ARP_Find_Entry(UINT8 *dest);
UINT8 ARP_Resolve(UINT8*ip_dest, 
                   UINT8 *mac_dest, UINT8 *buf_ptr,UINT16 buf_len);
void  ARP_Request(UINT8 *tip,  UINT8 *thardware);
INT16 ARP_Cache_Update(UINT8 * ipn,  UINT8 *hrdn, UINT8 flags);
void  ARP_Reply(UINT8 *thardware, UINT8 * tipnum);
//VOID        ARP_Event(UINT16 id);
void ARP_Interpret(ARP_LAYER *a_pkt);
void ARP_Build_Pkt ( UINT8 * tipnum, ARP_LAYER *arp_packet,
                            UINT8 *thardware, UINT8 *sipnum, UINT16 pkt_type);

void ARP_Check_Events(ARP_LAYER *a_pkt);
/* Offsets of the ARP header fields. */
#define ARP_HRD_OFFSET              0
#define ARP_PRO_OFFSET              2
#define ARP_HLN_OFFSET              4
#define ARP_PLN_OFFSET              5
#define ARP_OP_OFFSET               6
#define ARP_SHA_OFFSET              8
#define ARP_SPA_OFFSET              14
#define ARP_THA_OFFSET              18
#define ARP_TPA_OFFSET              24

#endif /* ARP_H */