net/rarp.c

   1 /*
   2  * (C) Copyright 2000-2002
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <command.h>
  10 #include <net.h>
  11 #include "nfs.h"
  12 #include "bootp.h"
  13 #include "rarp.h"
  14 #include "tftp.h"
  15
  16 #define TIMEOUT 5000UL /* Milliseconds before trying BOOTP again */
  17 #ifndef CONFIG_NET_RETRY_COUNT
  18 #define TIMEOUT_COUNT 5 /* # of timeouts before giving up  */
  19 #else
  20 #define TIMEOUT_COUNT (CONFIG_NET_RETRY_COUNT)
  21 #endif
  22
  23 int RarpTry;
  24
  25 /*
  26  *      Handle a RARP received packet.
  27  */
  28 void rarp_receive(struct ip_udp_hdr *ip, unsigned len)
  29 {
  30         struct arp_hdr *arp;
  31
  32         debug_cond(DEBUG_NET_PKT, "Got RARP\n");
  33         arp = (struct arp_hdr *)ip;
  34         if (len < ARP_HDR_SIZE) {
  35                 printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
  36                 return;
  37         }
  38
  39         if ((ntohs(arp->ar_op) != RARPOP_REPLY) ||
  40                 (ntohs(arp->ar_hrd) != ARP_ETHER)   ||
  41                 (ntohs(arp->ar_pro) != PROT_IP)     ||
  42                 (arp->ar_hln != 6) || (arp->ar_pln != 4)) {
  43
  44                 puts("invalid RARP header\n");
  45         } else {
  46                 NetCopyIP(&NetOurIP, &arp->ar_data[16]);
  47                 if (NetServerIP == 0)
  48                         NetCopyIP(&NetServerIP, &arp->ar_data[6]);
  49                 memcpy(NetServerEther, &arp->ar_data[0], 6);
  50                 debug_cond(DEBUG_DEV_PKT, "Got good RARP\n");
  51                 net_auto_load();
  52         }
  53 }
  54
  55
  56 /*
  57  *      Timeout on BOOTP request.
  58  */
  59 static void RarpTimeout(void)
  60 {
  61         if (RarpTry >= TIMEOUT_COUNT) {
  62                 puts("\nRetry count exceeded; starting again\n");
  63                 NetStartAgain();
  64         } else {
  65                 NetSetTimeout(TIMEOUT, RarpTimeout);
  66                 RarpRequest();
  67         }
  68 }
  69
  70
  71 void RarpRequest(void)
  72 {
  73         uchar *pkt;
  74         struct arp_hdr *rarp;
  75         int eth_hdr_size;
  76
  77         printf("RARP broadcast %d\n", ++RarpTry);
  78         pkt = NetTxPacket;
  79
  80         eth_hdr_size = NetSetEther(pkt, NetBcastAddr, PROT_RARP);
  81         pkt += eth_hdr_size;
  82
  83         rarp = (struct arp_hdr *)pkt;
  84
  85         rarp->ar_hrd = htons(ARP_ETHER);
  86         rarp->ar_pro = htons(PROT_IP);
  87         rarp->ar_hln = 6;
  88         rarp->ar_pln = 4;
  89         rarp->ar_op  = htons(RARPOP_REQUEST);
  90         memcpy(&rarp->ar_data[0],  NetOurEther, 6);     /* source ET addr */
  91         memcpy(&rarp->ar_data[6],  &NetOurIP,   4);     /* source IP addr */
  92         /* dest ET addr = source ET addr ??*/
  93         memcpy(&rarp->ar_data[10], NetOurEther, 6);
  94         /* dest IP addr set to broadcast */
  95         memset(&rarp->ar_data[16], 0xff,        4);
  96
  97         NetSendPacket(NetTxPacket, eth_hdr_size + ARP_HDR_SIZE);
  98
  99         NetSetTimeout(TIMEOUT, RarpTimeout);
 100 }