/*      $NetBSD: compat_ns_addr.c,v 1.5 2025/12/16 12:39:01 nia Exp $   */

/*
 * Copyright (c) 1986, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * J.Q. Johnson.
 *
 * 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. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 */

#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)ns_addr.c   8.1 (Berkeley) 6/7/93";
#else
__RCSID("$NetBSD: compat_ns_addr.c,v 1.5 2025/12/16 12:39:01 nia Exp $");
#endif
#endif /* LIBC_SCCS and not lint */

#include "namespace.h"
#include <sys/param.h>
#include <sys/endian.h>
#include <compat/include/ns.h>

#include <assert.h>
#include <stdio.h>
#include <string.h>

static void Field(char *, uint8_t *, int);
static void cvtbase(long, int, int[], int, uint8_t [], int);

struct ns_addr 
ns_addr(const char *name)
{
        char separator;
        char *hostname, *socketname, *cp;
        char buf[50];
        static struct ns_addr addr;

        _DIAGASSERT(name != NULL);

        (void)strlcpy(buf, name, sizeof(buf));

        /*
         * First, figure out what he intends as a field separator.
         * Despite the way this routine is written, the preferred
         * form  2-272.AA001234H.01777, i.e. XDE standard.
         * Great efforts are made to ensure backward compatibility.
         */
        if ((hostname = strchr(buf, '#')) != NULL)
                separator = '#';
        else {
                hostname = strchr(buf, '.');
                if ((cp = strchr(buf, ':')) &&
                    ((hostname && cp < hostname) || (hostname == 0))) {
                        hostname = cp;
                        separator = ':';
                } else
                        separator = '.';
        }
        if (hostname)
                *hostname++ = 0;

        memset(&addr, '\0', sizeof(addr));
        Field(buf, addr.x_net.c_net, 4);
        if (hostname == 0)
                return (addr);  /* No separator means net only */

        socketname = strchr(hostname, separator);
        if (socketname) {
                *socketname++ = 0;
                Field(socketname, (uint8_t *)(void *)&addr.x_port, 2);
        }

        Field(hostname, addr.x_host.c_host, 6);

        return (addr);
}

static void
Field(char *buf, uint8_t *out, int len)
{
        register char *bp = buf;
        int i, ibase, base16 = 0, base10 = 0;
        unsigned int clen = 0;
        int hb[6], *hp;

        _DIAGASSERT(buf != NULL);
        _DIAGASSERT(out != NULL);

        /*
         * first try 2-273#2-852-151-014#socket
         */
        if ((*buf != '-') &&
            (1 < (i = sscanf(buf, "%d-%d-%d-%d-%d",
                        &hb[0], &hb[1], &hb[2], &hb[3], &hb[4])))) {
                cvtbase(1000L, 256, hb, i, out, len);
                return;
        }
        /*
         * try form 8E1#0.0.AA.0.5E.E6#socket
         */
        if (1 < (i = sscanf(buf,"%x.%x.%x.%x.%x.%x",
                        &hb[0], &hb[1], &hb[2], &hb[3], &hb[4], &hb[5]))) {
                cvtbase(256L, 256, hb, i, out, len);
                return;
        }
        /*
         * try form 8E1#0:0:AA:0:5E:E6#socket
         */
        if (1 < (i = sscanf(buf,"%x:%x:%x:%x:%x:%x",
                        &hb[0], &hb[1], &hb[2], &hb[3], &hb[4], &hb[5]))) {
                cvtbase(256L, 256, hb, i, out, len);
                return;
        }
        /*
         * This is REALLY stretching it but there was a
         * comma notation separating shorts -- definitely non standard
         */
        if (1 < (i = sscanf(buf,"%x,%x,%x",
                        &hb[0], &hb[1], &hb[2]))) {
                hb[0] = htons(hb[0]); hb[1] = htons(hb[1]);
                hb[2] = htons(hb[2]);
                cvtbase(65536L, 256, hb, i, out, len);
                return;
        }

        /* Need to decide if base 10, 16 or 8 */
        while (*bp) switch (*bp++) {

        case '0': case '1': case '2': case '3': case '4': case '5':
        case '6': case '7': case '-':
                break;

        case '8': case '9':
                base10 = 1;
                break;

        case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
        case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
                base16 = 1;
                break;
        
        case 'x': case 'X':
                *--bp = '0';
                base16 = 1;
                break;

        case 'h': case 'H':
                base16 = 1;
                /* FALLTHROUGH */

        default:
                *--bp = 0; /* Ends Loop */
        }
        if (base16) {
                ibase = 4096;
        } else if (base10 == 0 && *buf == '0') {
                ibase = 512;
        } else {
                base10 = 1;
                ibase = 1000;
        }

        for (bp = buf; *bp++; ) clen++;
        if (clen == 0) clen++;
        if (clen > 18) clen = 18;
        i = ((clen - 1) / 3) + 1;
        bp = clen + buf - 3;
        hp = hb + i - 1;

        while (hp > hb) {
                if (base16)
                        (void)sscanf(bp, "%3x", hp);
                else if (base10)
                        (void)sscanf(bp, "%3d", hp);
                else
                        (void)sscanf(bp, "%3o", hp);

                bp[0] = 0;
                hp--;
                bp -= 3;
        }
        if (base16)
                (void)sscanf(buf, "%3x", hp);
        else if (base10)
                (void)sscanf(buf, "%3d", hp);
        else
                (void)sscanf(buf, "%3o", hp);

        cvtbase((long)ibase, 256, hb, i, out, len);
}

static void
cvtbase(long oldbase, int newbase, int input[], int inlen,
        uint8_t result[], int reslen)
{
        int d, e;
        long sum;

        _DIAGASSERT(input != NULL);
        _DIAGASSERT(result != NULL);
        _DIAGASSERT(inlen > 0);

        e = 1;
        while (e > 0 && reslen > 0) {
                d = 0; e = 0; sum = 0;
                /* long division: input=input/newbase */
                while (d < inlen) {
                        sum = sum*oldbase + (long) input[d];
                        e += (sum > 0);
                        input[d++] = (int) (sum / newbase);
                        sum %= newbase;
                }
                /* accumulate remainder */
                result[--reslen] = (unsigned char)sum;
        }
        for (d=0; d < reslen; d++)
                result[d] = 0;
}