191 lines
5.2 KiB
C
191 lines
5.2 KiB
C
/*
|
|
* File: arp.c
|
|
* Purpose: Address Resolution Protocol routines.
|
|
*
|
|
* Notes:
|
|
*/
|
|
|
|
#include "net.h"
|
|
#include "bootp.h"
|
|
#include <stdbool.h>
|
|
#include <stddef.h>
|
|
|
|
#define TIMER_NETWORK 0
|
|
|
|
void bootp_request(NIF *nif, uint8_t *pa)
|
|
{
|
|
/*
|
|
* This function broadcasts a BOOTP request for the protocol
|
|
* address "pa"
|
|
*/
|
|
uint8_t *addr;
|
|
NBUF *pNbuf;
|
|
bootp_frame_hdr *bootpframe;
|
|
int i, result;
|
|
|
|
pNbuf = nbuf_alloc();
|
|
if (pNbuf == NULL)
|
|
{
|
|
#if defined(DEBUG_PRINT)
|
|
xprintf("%s: arp_request couldn't allocate Tx buffer\r\n", __FUNCTION__);
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
bootpframe = (bootp_frame_hdr *) &pNbuf->data[BOOTP_HDR_OFFSET];
|
|
|
|
/* Build the BOOTP request packet */
|
|
bootpframe->type = BOOTP_TYPE_BOOTREQUEST;
|
|
bootpframe->htype = BOOTP_HTYPE_ETHERNET;
|
|
bootpframe->hlen = BOOTP_HLEN_ETHERNET;
|
|
bootpframe->hops = 0;
|
|
bootpframe->xid = 0x1234;
|
|
bootpframe->secs = 1;
|
|
bootpframe->flags = BOOTP_FLAGS_BROADCAST;
|
|
bootpframe->cl_addr = 0x0;
|
|
bootpframe->yi_addr = 0x0;
|
|
bootpframe->gi_addr = 0x0;
|
|
|
|
addr = &nif->hwa[0];
|
|
for (i = 0; i < 6; i++)
|
|
bootpframe->ch_addr[i] = addr[i];
|
|
|
|
pNbuf->length = BOOTP_HDR_LEN;
|
|
|
|
/* Send the BOOTP request */
|
|
result = nif->send(nif, nif->broadcast, nif->hwa, ETH_FRM_IP, pNbuf);
|
|
|
|
if (result == 0)
|
|
nbuf_free(pNbuf);
|
|
}
|
|
|
|
void bootp_handler(NIF *nif, NBUF *pNbuf)
|
|
{
|
|
/*
|
|
* ARP protocol handler
|
|
*/
|
|
uint8_t *addr;
|
|
bootp_frame_hdr *rx_bootpframe, *tx_bootpframe;
|
|
|
|
rx_bootpframe = (bootp_frame_hdr *) &pNbuf->data[pNbuf->offset];
|
|
|
|
#ifdef _NOT_USED_
|
|
/*
|
|
* Check for an appropriate ARP packet
|
|
*/
|
|
if ((pNbuf->length < ARP_HDR_LEN) ||
|
|
(rx_arpframe->ar_hrd != ETHERNET) ||
|
|
(rx_arpframe->ar_hln != 6) ||
|
|
(rx_arpframe->ar_pro != ETH_FRM_IP) ||
|
|
(rx_arpframe->ar_pln != 4))
|
|
{
|
|
nbuf_free(pNbuf);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Check to see if it was addressed to me - if it was, keep this
|
|
* ARP entry in the table permanently; if not, mark it so that it
|
|
* can be displaced later if necessary
|
|
*/
|
|
addr = ip_get_myip(nif_get_protocol_info(nif,ETH_FRM_IP));
|
|
if ((rx_arpframe->ar_tpa[0] == addr[0]) &&
|
|
(rx_arpframe->ar_tpa[1] == addr[1]) &&
|
|
(rx_arpframe->ar_tpa[2] == addr[2]) &&
|
|
(rx_arpframe->ar_tpa[3] == addr[3]) )
|
|
{
|
|
longevity = ARP_ENTRY_PERM;
|
|
}
|
|
else
|
|
longevity = ARP_ENTRY_TEMP;
|
|
|
|
/*
|
|
* Add ARP info into the table
|
|
*/
|
|
arp_merge(arptab,
|
|
rx_arpframe->ar_pro,
|
|
rx_arpframe->ar_hln,
|
|
&rx_arpframe->ar_sha[0],
|
|
rx_arpframe->ar_pln,
|
|
&rx_arpframe->ar_spa[0],
|
|
longevity
|
|
);
|
|
|
|
switch (rx_arpframe->opcode)
|
|
{
|
|
case ARP_REQUEST:
|
|
/*
|
|
* Check to see if request is directed to me
|
|
*/
|
|
if ((rx_arpframe->ar_tpa[0] == addr[0]) &&
|
|
(rx_arpframe->ar_tpa[1] == addr[1]) &&
|
|
(rx_arpframe->ar_tpa[2] == addr[2]) &&
|
|
(rx_arpframe->ar_tpa[3] == addr[3]) )
|
|
{
|
|
/*
|
|
* Reuse the current network buffer to assemble an ARP reply
|
|
*/
|
|
tx_arpframe = (arp_frame_hdr *)&pNbuf->data[ARP_HDR_OFFSET];
|
|
|
|
/*
|
|
* Build new ARP frame from the received data
|
|
*/
|
|
tx_arpframe->ar_hrd = ETHERNET;
|
|
tx_arpframe->ar_pro = ETH_FRM_IP;
|
|
tx_arpframe->ar_hln = 6;
|
|
tx_arpframe->ar_pln = 4;
|
|
tx_arpframe->opcode = ARP_REPLY;
|
|
tx_arpframe->ar_tha[0] = rx_arpframe->ar_sha[0];
|
|
tx_arpframe->ar_tha[1] = rx_arpframe->ar_sha[1];
|
|
tx_arpframe->ar_tha[2] = rx_arpframe->ar_sha[2];
|
|
tx_arpframe->ar_tha[3] = rx_arpframe->ar_sha[3];
|
|
tx_arpframe->ar_tha[4] = rx_arpframe->ar_sha[4];
|
|
tx_arpframe->ar_tha[5] = rx_arpframe->ar_sha[5];
|
|
tx_arpframe->ar_tpa[0] = rx_arpframe->ar_spa[0];
|
|
tx_arpframe->ar_tpa[1] = rx_arpframe->ar_spa[1];
|
|
tx_arpframe->ar_tpa[2] = rx_arpframe->ar_spa[2];
|
|
tx_arpframe->ar_tpa[3] = rx_arpframe->ar_spa[3];
|
|
|
|
/*
|
|
* Now copy in the new information
|
|
*/
|
|
addr = &nif->hwa[0];
|
|
tx_arpframe->ar_sha[0] = addr[0];
|
|
tx_arpframe->ar_sha[1] = addr[1];
|
|
tx_arpframe->ar_sha[2] = addr[2];
|
|
tx_arpframe->ar_sha[3] = addr[3];
|
|
tx_arpframe->ar_sha[4] = addr[4];
|
|
tx_arpframe->ar_sha[5] = addr[5];
|
|
|
|
addr = ip_get_myip(nif_get_protocol_info(nif,ETH_FRM_IP));
|
|
tx_arpframe->ar_spa[0] = addr[0];
|
|
tx_arpframe->ar_spa[1] = addr[1];
|
|
tx_arpframe->ar_spa[2] = addr[2];
|
|
tx_arpframe->ar_spa[3] = addr[3];
|
|
|
|
/*
|
|
* Save the length of my packet in the buffer structure
|
|
*/
|
|
pNbuf->length = ARP_HDR_LEN;
|
|
|
|
nif->send(nif,
|
|
&tx_arpframe->ar_tha[0],
|
|
&tx_arpframe->ar_sha[0],
|
|
ETH_FRM_ARP,
|
|
pNbuf);
|
|
}
|
|
else
|
|
nbuf_free(pNbuf);
|
|
break;
|
|
case ARP_REPLY:
|
|
/*
|
|
* The ARP Reply case is already taken care of
|
|
*/
|
|
default:
|
|
nbuf_free(pNbuf);
|
|
break;
|
|
}
|
|
#endif /* _NOT_USED_ */
|
|
return;
|
|
}
|