1/*
2 * Copyright 2010, Haiku, Inc. All Rights Reserved.
3 * Distributed under the terms of the MIT License.
4 */
5
6/*
7 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
8 * Copyright (c) 1996-1999 by Internet Software Consortium.
9 *
10 * Permission to use, copy, modify, and distribute this software for any
11 * purpose with or without fee is hereby granted, provided that the above
12 * copyright notice and this permission notice appear in all copies.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
15 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
16 * MERCHANTABILITY AND FITNESS.	 IN NO EVENT SHALL ISC BE LIABLE FOR
17 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
18 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
19 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
20 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
21 */
22
23
24#include <net_datalink.h>
25
26#include <ByteOrder.h>
27#include <KernelExport.h>
28#include <NetUtilities.h>
29
30#include <memory.h>
31#include <netinet6/in6.h>
32#include <stdio.h>
33#include <stdlib.h>
34#include <string.h>
35
36#include "ipv6_utils.h"
37
38
39#define NS_IN6ADDRSZ 16
40#define NS_INT16SZ 2
41
42#define SPRINTF(x) ((size_t)sprintf x)
43
44
45/*!	Convert IPv6 binary address into presentation (printable) format.
46	Author: Paul Vixie, 1996.
47	\return pointer to dst string if address as been printed
48	\return NULL if the buffer is too short
49*/
50const char *
51ip6_sprintf(const in6_addr *srcaddr, char *dst, size_t size)
52{
53	/*
54	 * Note that int32_t and int16_t need only be "at least" large enough
55	 * to contain a value of the specified size.  On some systems, like
56	 * Crays, there is no such thing as an integer variable with 16 bits.
57	 * Keep this in mind if you think this function should have been coded
58	 * to use pointer overlays.	 All the world's not a VAX.
59	 */
60	char tmp[INET6_ADDRSTRLEN], *tp;
61	struct { int base, len; } best, cur;
62	uint16 words[NS_IN6ADDRSZ / NS_INT16SZ];
63	int i;
64	const uint8 *src = srcaddr->s6_addr;
65
66	/*
67	 * Preprocess:
68	 *	Copy the input (bytewise) array into a wordwise array.
69	 *	Find the longest run of 0x00's in src[] for :: shorthanding.
70	 */
71	memset(words, '\0', sizeof words);
72	for (i = 0; i < NS_IN6ADDRSZ; i++)
73		words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
74	best.base = -1;
75	best.len = 0;
76	cur.base = -1;
77	cur.len = 0;
78	for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
79		if (words[i] == 0) {
80			if (cur.base == -1)
81				cur.base = i, cur.len = 1;
82			else
83				cur.len++;
84		} else {
85			if (cur.base != -1) {
86				if (best.base == -1 || cur.len > best.len)
87					best = cur;
88				cur.base = -1;
89			}
90		}
91	}
92	if (cur.base != -1) {
93		if (best.base == -1 || cur.len > best.len)
94			best = cur;
95	}
96	if (best.base != -1 && best.len < 2)
97		best.base = -1;
98
99	/*
100	 * Format the result.
101	 */
102	tp = tmp;
103	for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
104		/* Are we inside the best run of 0x00's? */
105		if (best.base != -1 && i >= best.base &&
106			i < (best.base + best.len)) {
107			if (i == best.base)
108				*tp++ = ':';
109			continue;
110		}
111		/* Are we following an initial run of 0x00s or any real hex? */
112		if (i != 0)
113			*tp++ = ':';
114		/* Is this address an encapsulated IPv4? */
115#if 0
116		if (i == 6 && best.base == 0 && (best.len == 6 ||
117			(best.len == 7 && words[7] != 0x0001) ||
118			(best.len == 5 && words[5] == 0xffff))) {
119			if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp)))
120				return (NULL);
121			tp += strlen(tp);
122			break;
123		}
124#endif
125		tp += SPRINTF((tp, "%x", words[i]));
126	}
127	/* Was it a trailing run of 0x00's? */
128	if (best.base != -1 && (best.base + best.len) ==
129		(NS_IN6ADDRSZ / NS_INT16SZ))
130		*tp++ = ':';
131	*tp++ = '\0';
132
133	/*
134	 * Check for overflow, copy, and we're done.
135	 */
136	if ((size_t)(tp - tmp) > size)
137		return NULL;
138
139	strcpy(dst, tmp);
140	return dst;
141}
142