/*	$NetBSD: etherfun.c,v 1.6 2005/05/17 04:14:57 christos Exp $	*/

/*
 *
 * Copyright (c) 1995 Charles D. Cranor and Seth Widoff
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Charles D. Cranor
 *	and Seth Widoff.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/* etherfun.c */

#include "sboot.h"
#include "etherfun.h"

/* Construct and send a rev arp packet */
void
do_rev_arp () 
{
  int i;
  
  for ( i = 0; i < 6; i++ ) {
    eh->ether_dhost[i] = 0xff;
  }
  memcpy(eh->ether_shost, myea, 6);
  eh->ether_type = ETYPE_RARP;
  
  rarp->ar_hrd = 1;              /* hardware type is 1 */
  rarp->ar_pro = PTYPE_IP;
  rarp->ar_hln = 6;              /* length of hardware address is 6 bytes */
  rarp->ar_pln = 4;              /* length of ip address is 4 byte */
  rarp->ar_op = OPCODE_RARP;
  memcpy(rarp->arp_sha, myea, sizeof(myea));
  memcpy(rarp->arp_tha, myea, sizeof(myea));
  for ( i = 0; i < 4; i++ ) {
    rarp->arp_spa[i] = rarp->arp_tpa[i] = 0x00;
  }

  le_put(buf, 76);
}
  
/* Receive and disassemble the rev_arp reply */

int
get_rev_arp () 
{
  le_get(buf, sizeof(buf), 6);
  if ( eh->ether_type == ETYPE_RARP && rarp->ar_op == OPCODE_REPLY ) {
    memcpy(myip, rarp->arp_tpa, sizeof(rarp->arp_tpa));
    memcpy(servip, rarp->arp_spa, sizeof(rarp->arp_spa));
    memcpy(servea, rarp->arp_sha, sizeof(rarp->arp_sha));
    return 1;
  }
  return 0;
}

/* Try to get a reply to a rev arp request */

int 
rev_arp () 
{
  int tries = 0;
  while ( tries < 5 ) {
    do_rev_arp();
    if ( get_rev_arp() ) {
      return 1;
    }
    tries++;
  }
  return 0;
} 

/* Send a tftp read request or acknowledgement 
   mesgtype 0 is a read request, 1 is an aknowledgement */

void 
do_send_tftp ( int mesgtype ) 
{
  u_long res, iptmp, lcv;
  char *tot;

  if ( mesgtype == 0 ) {
    tot = tftp_r + (sizeof(MSG)-1);
    myport = (u_short)time();
    if (myport < 1000) myport += 1000;
    servport = FTP_PORT; /* to start */
  } else {
    tot = (char *)tftp_a + 4;
  }

  memcpy (eh->ether_dhost, servea, sizeof(servea));
  memcpy (eh->ether_shost, myea, sizeof(myea));
  eh->ether_type = ETYPE_IP;
  
  iph->ip_v = IP_VERSION;
  iph->ip_hl = IP_HLEN;   
  iph->ip_tos = 0;         /* type of service is 0 */
  iph->ip_id = 0;          /* id field is 0 */
  iph->ip_off = IP_DF;
  iph->ip_ttl = 3;         /* time to live is 3 seconds/hops */
  iph->ip_p = IPP_UDP;
  memcpy(iph->ip_src, myip, sizeof(myip));
  memcpy(iph->ip_dst, servip, sizeof(servip));
  iph->ip_sum = 0;
  iph->ip_len = tot - (char *)iph;
  res = oc_cksum(iph, sizeof(struct ip), 0);
  iph->ip_sum = 0xffff & ~res;
  udph->uh_sport = myport;
  udph->uh_dport = servport;
  udph->uh_sum = 0;
  
  if ( mesgtype )  {
    tftp_a->op_code = FTPOP_ACKN;
    tftp_a->block = (u_short)(mesgtype);
  } else {
    memcpy (&iptmp, myip, sizeof(iptmp));
    memcpy(tftp_r, MSG, (sizeof(MSG)-1));
    for (lcv = 9; lcv >= 2; lcv--) {
      tftp_r[lcv] = HEXDIGITS[iptmp & 0xF];
      
      iptmp = iptmp >> 4;
    }
  }

  udph->uh_ulen = tot - (char *)udph;

  le_put( buf, tot - buf);
}

/* Attempt to tftp a file and read it into memory */

int
do_get_file () 
{
  int fail = 0, oldlen;
  char *loadat = (char *)LOAD_ADDR;
  last_ack = 0;

  do_send_tftp( READ );
  while (1) {
    if ( le_get(buf, sizeof(buf), 5) == 0) { /* timeout occurred */
      if ( last_ack ) {                          
	do_send_tftp( last_ack );
      } else {
	do_send_tftp( READ );
      }
      fail++;
      if ( fail > 5 ) {
        printf("\n");
	return 1;
      }
    } else {
      printf("%x \r", tftp->info.block*512);
      if ((eh->ether_type != ETYPE_IP) || (iph->ip_p != IPP_UDP)) {
	fail++;
	continue;
      }
      if (servport == FTP_PORT) servport = udph->uh_sport;
      if (tftp->info.op_code == FTPOP_ERR) {
	printf("TFTP: Download error %d: %s\n", 
	       tftp->info.block, tftp->data);
        return 1;
      }
      if (tftp->info.block != last_ack + 1) { /* we received the wrong block */
	if (tftp->info.block < last_ack +1) {
	  do_send_tftp(tftp->info.block); /* ackn whatever we received */
	} else {
	  do_send_tftp( last_ack );       /* ackn the last confirmed block */
        }
	fail++;
      } else {                /* we got the right block */
	fail = 0;
	last_ack++;
        oldlen = udph->uh_ulen;
	do_send_tftp( last_ack );
	/*printf("memcpy %x %x %d\n", loadat, &tftp->data, oldlen - 12);*/
	memcpy(loadat, &tftp->data, oldlen - 12);
	loadat += oldlen - 12;
	if (oldlen < (8 + 4 + 512)) {
          printf("\n");
	  return 0;
        }
      }
    }
  }
  printf("\n");
  return 0;
}