//==========================================================================
//
//      src/inet_ntop.c
//
//==========================================================================
// ####BSDCOPYRIGHTBEGIN####                                    
// -------------------------------------------                  
// This file is part of eCos, the Embedded Configurable Operating System.
//
// Portions of this software may have been derived from FreeBSD, OpenBSD,
// or other sources, and if so are covered by the appropriate copyright
// and license included herein.                                 
//
// Portions created by the Free Software Foundation are         
// Copyright (C) 2002 Free Software Foundation, Inc.            
// -------------------------------------------                  
// ####BSDCOPYRIGHTEND####                                      
//==========================================================================

/*	$OpenBSD: inet_ntop.c,v 1.1 1997/03/13 19:07:32 downsj Exp $	*/

/* Copyright (c) 1996 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <string.h>
#include <errno.h>
#ifndef CYGPKG_NET_FREEBSD_STACK
#include <stdio.h>
#endif

#ifndef IN6ADDRSZ
#define IN6ADDRSZ    16      /* IPv6 T_AAAA */
#endif
#ifndef INT16SZ
#define INT16SZ	sizeof(u_int16_t)
#endif

/*
 * WARNING: Don't even consider trying to compile this on a system where
 * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
 */

static const char *inet_ntop4 __P((const u_char *src, char *dst, size_t size));
#ifdef CYGPKG_NET_INET6
static const char *inet_ntop6 __P((const u_char *src, char *dst, size_t size));
#endif

/* char *
 * inet_ntop(af, src, dst, size)
 *	convert a network format address to presentation format.
 * return:
 *	pointer to presentation format address (`dst'), or NULL (see errno).
 * author:
 *	Paul Vixie, 1996.
 */
const char *
inet_ntop(int af, const void *src, char *dst, size_t size)
{
	switch (af) {
	case AF_INET:
		return (inet_ntop4(src, dst, size));
#ifdef CYGPKG_NET_INET6
	case AF_INET6:
		return (inet_ntop6(src, dst, size));
#endif
	default:
		errno = EAFNOSUPPORT;
		return (NULL);
	}
	/* NOTREACHED */
}

//
// A more useful conversion routine
// Convert a network [socket] address to presentation format
// This routine handles all of the mapping required and isolates
// the knowledge of the structure format.
//
const char *
_inet_ntop(struct sockaddr *sa, char *dst, size_t size)
{
    switch (sa->sa_family) {
    case AF_INET:
        return (inet_ntop(AF_INET, (char *)&((struct sockaddr_in *)sa)->sin_addr, 
                          dst, size));
#ifdef CYGPKG_NET_INET6
    case AF_INET6:
        return (inet_ntop(AF_INET6, (char *)&((struct sockaddr_in6 *)sa)->sin6_addr, 
                          dst, size));
#endif
    default:
        errno = EAFNOSUPPORT;
        return (NULL);
    }
}

u_int16_t
_inet_port(struct sockaddr *sa)
{
    switch (sa->sa_family) {
    case AF_INET:
        return (ntohs(((struct sockaddr_in *)sa)->sin_port)); 
#ifdef CYGPKG_NET_INET6
    case AF_INET6:
        return (ntohs(((struct sockaddr_in6 *)sa)->sin6_port)); 
#endif
    default:
        return 0;  // Unknown!
    }
}

/* const char *
 * inet_ntop4(src, dst, size)
 *	format an IPv4 address, more or less like inet_ntoa()
 * return:
 *	`dst' (as a const)
 * notes:
 *	(1) uses no statics
 *	(2) takes a u_char* not an in_addr as input
 * author:
 *	Paul Vixie, 1996.
 */
static const char *
inet_ntop4(src, dst, size)
	const u_char *src;
	char *dst;
	size_t size;
{
	static const char fmt[] = "%u.%u.%u.%u";
	char tmp[sizeof "255.255.255.255"];

	if (sprintf(tmp, fmt, src[0], src[1], src[2], src[3]) > size) {
		errno = ENOSPC;
		return (NULL);
	}
	strcpy(dst, tmp);
	return (dst);
}

#ifdef CYGPKG_NET_INET6
/* const char *
 * inet_ntop6(src, dst, size)
 *	convert IPv6 binary address into presentation (printable) format
 * author:
 *	Paul Vixie, 1996.
 */
static const char *
inet_ntop6(const u_char *src, char *dst, size_t size)
{
	/*
	 * Note that int32_t and int16_t need only be "at least" large enough
	 * to contain a value of the specified size.  On some systems, like
	 * Crays, there is no such thing as an integer variable with 16 bits.
	 * Keep this in mind if you think this function should have been coded
	 * to use pointer overlays.  All the world's not a VAX.
	 */
#if 0 // This is too optimistic
	char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
#else
	char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff"], *tp;
#endif
	struct { int base, len; } best, cur;
	u_int words[IN6ADDRSZ / INT16SZ];
	int i;

	/*
	 * Preprocess:
	 *	Copy the input (bytewise) array into a wordwise array.
	 *	Find the longest run of 0x00's in src[] for :: shorthanding.
	 */
	memset(words, '\0', sizeof words);
	for (i = 0; i < IN6ADDRSZ; i++)
		words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
	best.base = -1;
	cur.base = -1;
	for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
		if (words[i] == 0) {
			if (cur.base == -1)
				cur.base = i, cur.len = 1;
			else
				cur.len++;
		} else {
			if (cur.base != -1) {
				if (best.base == -1 || cur.len > best.len)
					best = cur;
				cur.base = -1;
			}
		}
	}
	if (cur.base != -1) {
		if (best.base == -1 || cur.len > best.len)
			best = cur;
	}
	if (best.base != -1 && best.len < 2)
		best.base = -1;

	/*
	 * Format the result.
	 */
	tp = tmp;
	for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
		/* Are we inside the best run of 0x00's? */
		if (best.base != -1 && i >= best.base &&
		    i < (best.base + best.len)) {
			if (i == best.base)
				*tp++ = ':';
			continue;
		}
		/* Are we following an initial run of 0x00s or any real hex? */
		if (i != 0)
			*tp++ = ':';
		/* Is this address an encapsulated IPv4? */
		if (i == 6 && best.base == 0 &&
		    (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
			if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp)))
				return (NULL);
			tp += strlen(tp);
			break;
		}
		tp += sprintf(tp, "%x", words[i]);
	}
	/* Was it a trailing run of 0x00's? */
	if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ))
		*tp++ = ':';
	*tp++ = '\0';

	/*
	 * Check for overflow, copy, and we're done.
	 */
	if ((size_t)(tp - tmp) > size) {
		errno = ENOSPC;
		return (NULL);
	}
	strcpy(dst, tmp);
	return (dst);
}
#endif
