/*      $NetBSD: etherfun.c,v 1.12 2011/09/29 09:18:17 he 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.
*
* 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(void)
{
       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(void)
{

       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(void)
{
       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 */
const char HEXDIGITS[16] = "0123456789ABCDEF";

void
do_send_tftp(int mesgtype)
{
       u_long res, iptmp, lcv;
       u_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 = (u_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 - (u_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 - (u_char *)udph;

       le_put(buf, tot - buf);
}

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

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

       do_send_tftp(READ);
       for (;;) {
               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) {
                                       /* ackn whatever we received */
                                       do_send_tftp(tftp->info.block);
                               } else {
                                       /* ackn the last confirmed block */
                                       do_send_tftp(last_ack);
                               }
                               fail++;
                       } else {                /* we got the right block */
                               fail = 0;
                               last_ack++;
                               oldlen = udph->uh_ulen;
                               do_send_tftp( last_ack );
#if 0
                               printf("memcpy %x %x %d\n", loadat,
                                   &tftp->data, oldlen - 12);
#endif
                               memcpy(loadat, &tftp->data, oldlen - 12);
                               loadat += oldlen - 12;
                               if (oldlen < (8 + 4 + 512)) {
                                       printf("\n");
                                       return 0;
                               }
                       }
               }
       }
       printf("\n");
       return 0;
}

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