net/rarp.c

   1 /*
   2  * (C) Copyright 2000-2002
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  */
  23
  24 #include <common.h>
  25 #include <command.h>
  26 #include <net.h>
  27 #include "nfs.h"
  28 #include "bootp.h"
  29 #include "rarp.h"
  30 #include "tftp.h"
  31
  32 #define TIMEOUT 5000UL /* Milliseconds before trying BOOTP again */
  33 #ifndef CONFIG_NET_RETRY_COUNT
  34 #define TIMEOUT_COUNT 5 /* # of timeouts before giving up  */
  35 #else
  36 #define TIMEOUT_COUNT (CONFIG_NET_RETRY_COUNT)
  37 #endif
  38
  39 int RarpTry;
  40
  41 /*
  42  *      Handle a RARP received packet.
  43  */
  44 void rarp_receive(struct ip_udp_hdr *ip, unsigned len)
  45 {
  46         struct arp_hdr *arp;
  47
  48         debug_cond(DEBUG_NET_PKT, "Got RARP\n");
  49         arp = (struct arp_hdr *)ip;
  50         if (len < ARP_HDR_SIZE) {
  51                 printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
  52                 return;
  53         }
  54
  55         if ((ntohs(arp->ar_op) != RARPOP_REPLY) ||
  56                 (ntohs(arp->ar_hrd) != ARP_ETHER)   ||
  57                 (ntohs(arp->ar_pro) != PROT_IP)     ||
  58                 (arp->ar_hln != 6) || (arp->ar_pln != 4)) {
  59
  60                 puts("invalid RARP header\n");
  61         } else {
  62                 NetCopyIP(&NetOurIP, &arp->ar_data[16]);
  63                 if (NetServerIP == 0)
  64                         NetCopyIP(&NetServerIP, &arp->ar_data[6]);
  65                 memcpy(NetServerEther, &arp->ar_data[0], 6);
  66                 debug_cond(DEBUG_DEV_PKT, "Got good RARP\n");
  67                 net_auto_load();
  68         }
  69 }
  70
  71
  72 /*
  73  *      Timeout on BOOTP request.
  74  */
  75 static void RarpTimeout(void)
  76 {
  77         if (RarpTry >= TIMEOUT_COUNT) {
  78                 puts("\nRetry count exceeded; starting again\n");
  79                 NetStartAgain();
  80         } else {
  81                 NetSetTimeout(TIMEOUT, RarpTimeout);
  82                 RarpRequest();
  83         }
  84 }
  85
  86
  87 void RarpRequest(void)
  88 {
  89         uchar *pkt;
  90         struct arp_hdr *rarp;
  91         int eth_hdr_size;
  92
  93         printf("RARP broadcast %d\n", ++RarpTry);
  94         pkt = NetTxPacket;
  95
  96         eth_hdr_size = NetSetEther(pkt, NetBcastAddr, PROT_RARP);
  97         pkt += eth_hdr_size;
  98
  99         rarp = (struct arp_hdr *)pkt;
 100
 101         rarp->ar_hrd = htons(ARP_ETHER);
 102         rarp->ar_pro = htons(PROT_IP);
 103         rarp->ar_hln = 6;
 104         rarp->ar_pln = 4;
 105         rarp->ar_op  = htons(RARPOP_REQUEST);
 106         memcpy(&rarp->ar_data[0],  NetOurEther, 6);     /* source ET addr */
 107         memcpy(&rarp->ar_data[6],  &NetOurIP,   4);     /* source IP addr */
 108         /* dest ET addr = source ET addr ??*/
 109         memcpy(&rarp->ar_data[10], NetOurEther, 6);
 110         /* dest IP addr set to broadcast */
 111         memset(&rarp->ar_data[16], 0xff,        4);
 112
 113         NetSendPacket(NetTxPacket, eth_hdr_size + ARP_HDR_SIZE);
 114
 115         NetSetTimeout(TIMEOUT, RarpTimeout);
 116 }