/*      $NetBSD: iso_addr.c,v 1.15 2013/03/01 18:25:16 joerg Exp $      */

/*
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  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. 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[] = "@(#)iso_addr.c  8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: iso_addr.c,v 1.15 2013/03/01 18:25:16 joerg Exp $");
#endif
#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>

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

struct iso_addr {
        uint8_t         isoa_len;       /* length (in bytes) */
        char            isoa_genaddr[20];       /* general opaque address */
};

__BEGIN_DECLS
struct iso_addr *iso_addr(const char *);
char *iso_ntoa(const struct iso_addr *);
__END_DECLS

/* States*/
#define VIRGIN  0
#define GOTONE  1
#define GOTTWO  2
/* Inputs */
#define DIGIT   (4*0)
#define END     (4*1)
#define DELIM   (4*2)

struct iso_addr *
iso_addr(const char *addr)
{
        static struct iso_addr out_addr;
        register char *cp = out_addr.isoa_genaddr;
        char *cplim = cp + sizeof(out_addr.isoa_genaddr);
        register int byte = 0, state = VIRGIN;
        register int newaddr = 0;       /* pacify gcc */

        _DIAGASSERT(addr != NULL);

        (void)memset(&out_addr, 0, sizeof (out_addr));
        do {
                if ((*addr >= '0') && (*addr <= '9')) {
                        newaddr = *addr - '0';
                } else if ((*addr >= 'a') && (*addr <= 'f')) {
                        newaddr = *addr - 'a' + 10;
                } else if ((*addr >= 'A') && (*addr <= 'F')) {
                        newaddr = *addr - 'A' + 10;
                } else if (*addr == 0) 
                        state |= END;
                else
                        state |= DELIM;
                addr++;
                switch (state /* | INPUT */) {
                case GOTTWO | DIGIT:
                        *cp++ = byte; /*FALLTHROUGH*/
                case VIRGIN | DIGIT:
                        state = GOTONE; byte = newaddr; continue;
                case GOTONE | DIGIT:
                        state = GOTTWO; byte = newaddr + (byte << 4); continue;
                default: /* | DELIM */
                        state = VIRGIN; *cp++ = byte; byte = 0; continue;
                case GOTONE | END:
                case GOTTWO | END:
                        *cp++ = byte; /* FALLTHROUGH */
                case VIRGIN | END:
                        break;
                }
                break;
        } while (cp < cplim); 
        _DIAGASSERT(__type_fit(uint8_t, cp - out_addr.isoa_genaddr));
        out_addr.isoa_len = (uint8_t)(cp - out_addr.isoa_genaddr);
        return (&out_addr);
}

static const char hexlist[16] = "0123456789abcdef";

char *
iso_ntoa(const struct iso_addr *isoa)
{
        static char obuf[64];
        char *out = obuf; 
        size_t i;
        const u_char *in = (const u_char *)isoa->isoa_genaddr;
        const u_char *inlim = in + isoa->isoa_len;

        _DIAGASSERT(isoa != NULL);

        out[1] = 0;
        while (in < inlim) {
                i = *in++;
                *out++ = '.';
                if (i > 0xf) {
                        out[1] = hexlist[i & 0xf];
                        i >>= 4;
                        out[0] = hexlist[i];
                        out += 2;
                } else
                        *out++ = hexlist[i];
        }
        *out = 0;
        return(obuf + 1);
}