/*      $NetBSD: etherfun.c,v 1.14 2025/08/09 15:11:10 skrll 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 acknowledgement */
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;
}