// SPDX-License-Identifier: GPL-2.0+

  /*
   * (C) Copyright 2000-2002
   * Wolfgang Denk, DENX Software Engineering, wd@denx.de.

   */
  
  #include <common.h>
  #include <command.h>
  #include <net.h>

  #include <net/tftp.h>

  #include "nfs.h"

  #include "bootp.h"
  #include "rarp.h"

  #define TIMEOUT 5000UL /* Milliseconds before trying BOOTP again */

  #ifndef	CONFIG_NET_RETRY_COUNT

  #define TIMEOUT_COUNT 5 /* # of timeouts before giving up  */

  #else

  #define TIMEOUT_COUNT (CONFIG_NET_RETRY_COUNT)

  #endif

  int rarp_try;

  
  /*
   *	Handle a RARP received packet.
   */

  void rarp_receive(struct ip_udp_hdr *ip, unsigned len)

  {

  	struct arp_hdr *arp;

  	debug_cond(DEBUG_NET_PKT, "Got RARP
  ");

  	arp = (struct arp_hdr *)ip;

  	if (len < ARP_HDR_SIZE) {
  		printf("bad length %d < %d
  ", len, ARP_HDR_SIZE);
  		return;
  	}
  
  	if ((ntohs(arp->ar_op) != RARPOP_REPLY) ||

  	    (ntohs(arp->ar_hrd) != ARP_ETHER)   ||
  	    (ntohs(arp->ar_pro) != PROT_IP)     ||
  	    (arp->ar_hln != 6) || (arp->ar_pln != 4)) {

  		puts("invalid RARP header
  ");
  	} else {

  		net_copy_ip(&net_ip, &arp->ar_data[16]);
  		if (net_server_ip.s_addr == 0)
  			net_copy_ip(&net_server_ip, &arp->ar_data[6]);

  		memcpy(net_server_ethaddr, &arp->ar_data[0], 6);

  		debug_cond(DEBUG_DEV_PKT, "Got good RARP
  ");

  		net_auto_load();
  	}

  }
  
  
  /*
   *	Timeout on BOOTP request.
   */

  static void rarp_timeout_handler(void)

  {

  	if (rarp_try >= TIMEOUT_COUNT) {

  		puts("
  Retry count exceeded; starting again
  ");

  		net_start_again();

  	} else {

  		net_set_timeout_handler(TIMEOUT, rarp_timeout_handler);

  		rarp_request();

  	}
  }

  void rarp_request(void)

  {

  	uchar *pkt;

  	struct arp_hdr *rarp;

  	int eth_hdr_size;

  	printf("RARP broadcast %d
  ", ++rarp_try);

  	pkt = net_tx_packet;

  	eth_hdr_size = net_set_ether(pkt, net_bcast_ethaddr, PROT_RARP);

  	pkt += eth_hdr_size;

  	rarp = (struct arp_hdr *)pkt;

  	rarp->ar_hrd = htons(ARP_ETHER);
  	rarp->ar_pro = htons(PROT_IP);

  	rarp->ar_hln = 6;
  	rarp->ar_pln = 4;

  	rarp->ar_op  = htons(RARPOP_REQUEST);

  	memcpy(&rarp->ar_data[0],  net_ethaddr, 6);	/* source ET addr */

  	memcpy(&rarp->ar_data[6],  &net_ip,   4);	/* source IP addr */

  	/* dest ET addr = source ET addr ??*/

  	memcpy(&rarp->ar_data[10], net_ethaddr, 6);

  	/* dest IP addr set to broadcast */
  	memset(&rarp->ar_data[16], 0xff,        4);

  	net_send_packet(net_tx_packet, eth_hdr_size + ARP_HDR_SIZE);

  	net_set_timeout_handler(TIMEOUT, rarp_timeout_handler);

  }