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
  40 int             RarpTry;
  41
  42 /*
  43  *      Handle a RARP received packet.
  44  */
  45 static void
  46 RarpHandler(uchar * dummi0, unsigned dummi1, unsigned dummi2, unsigned dummi3)
  47 {
  48         char *s;
  49         debug("Got good RARP\n");
  50         if ((s = getenv("autoload")) != NULL) {
  51                 if (*s == 'n') {
  52                         /*
  53                          * Just use RARP to configure system;
  54                          * Do not use TFTP/NFS to to load the bootfile.
  55                          */
  56                         NetState = NETLOOP_SUCCESS;
  57                         return;
  58 #if defined(CONFIG_CMD_NFS)
  59                 } else if ((s != NULL) && !strcmp(s, "NFS")) {
  60                         NfsStart();
  61                         return;
  62 #endif
  63                 }
  64         }
  65         TftpStart ();
  66 }
  67
  68
  69 /*
  70  *      Timeout on BOOTP request.
  71  */
  72 static void
  73 RarpTimeout(void)
  74 {
  75         if (RarpTry >= TIMEOUT_COUNT) {
  76                 puts ("\nRetry count exceeded; starting again\n");
  77                 NetStartAgain ();
  78         } else {
  79                 NetSetTimeout (TIMEOUT, RarpTimeout);
  80                 RarpRequest ();
  81         }
  82 }
  83
  84
  85 void
  86 RarpRequest (void)
  87 {
  88         int i;
  89         volatile uchar *pkt;
  90         ARP_t * rarp;
  91
  92         printf("RARP broadcast %d\n", ++RarpTry);
  93         pkt = NetTxPacket;
  94
  95         pkt += NetSetEther(pkt, NetBcastAddr, PROT_RARP);
  96
  97         rarp = (ARP_t *)pkt;
  98
  99         rarp->ar_hrd = htons (ARP_ETHER);
 100         rarp->ar_pro = htons (PROT_IP);
 101         rarp->ar_hln = 6;
 102         rarp->ar_pln = 4;
 103         rarp->ar_op  = htons (RARPOP_REQUEST);
 104         memcpy (&rarp->ar_data[0],  NetOurEther, 6);    /* source ET addr */
 105         memcpy (&rarp->ar_data[6],  &NetOurIP,   4);    /* source IP addr */
 106         memcpy (&rarp->ar_data[10], NetOurEther, 6);    /* dest ET addr = source ET addr ??*/
 107         /* dest. IP addr set to broadcast */
 108         for (i = 0; i <= 3; i++) {
 109                 rarp->ar_data[16 + i] = 0xff;
 110         }
 111
 112         NetSendPacket(NetTxPacket, (pkt - NetTxPacket) + ARP_HDR_SIZE);
 113
 114         NetSetTimeout(TIMEOUT, RarpTimeout);
 115         NetSetHandler(RarpHandler);
 116 }