1/* Copyright (c) 1996 by Internet Software Consortium.
2 *
3 * Permission to use, copy, modify, and distribute this software for any
4 * purpose with or without fee is hereby granted, provided that the above
5 * copyright notice and this permission notice appear in all copies.
6 *
7 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
8 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
9 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
10 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
11 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
12 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
13 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
14 * SOFTWARE.
15 */
16
17#include "apr_private.h"
18#include "apr_arch_networkio.h"
19#include "apr_strings.h"
20
21#if APR_HAVE_SYS_TYPES_H
22#include <sys/types.h>
23#endif
24#if APR_HAVE_SYS_SOCKET_H
25#include <sys/socket.h>
26#endif
27#if APR_HAVE_NETINET_IN_H
28#include <netinet/in.h>
29#endif
30#if APR_HAVE_ARPA_INET_H
31#include <arpa/inet.h>
32#endif
33#include <string.h>
34#if APR_HAVE_ERRNO_H
35#include <errno.h>
36#endif
37#include <stdio.h>
38
39#ifndef IN6ADDRSZ
40#define IN6ADDRSZ   16
41#endif
42
43#ifndef INT16SZ
44#define INT16SZ sizeof(apr_int16_t)
45#endif
46
47#ifndef __P
48#define __P(x) x
49#endif
50
51#if !defined(EAFNOSUPPORT) && defined(WSAEAFNOSUPPORT)
52#define EAFNOSUPPORT WSAEAFNOSUPPORT
53#endif
54
55/*
56 * WARNING: Don't even consider trying to compile this on a system where
57 * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
58 */
59
60static const char *inet_ntop4 __P((const unsigned char *src, char *dst, apr_size_t size));
61#if APR_HAVE_IPV6
62static const char *inet_ntop6 __P((const unsigned char *src, char *dst, apr_size_t size));
63#endif
64
65/* char *
66 * inet_ntop(af, src, dst, size)
67 *	convert a network format address to presentation format.
68 * return:
69 *	pointer to presentation format address (`dst'), or NULL (see errno).
70 * author:
71 *	Paul Vixie, 1996.
72 */
73const char *
74apr_inet_ntop(int af, const void *src, char *dst, apr_size_t size)
75{
76	switch (af) {
77	case AF_INET:
78		return (inet_ntop4(src, dst, size));
79#if APR_HAVE_IPV6
80	case AF_INET6:
81		return (inet_ntop6(src, dst, size));
82#endif
83	default:
84		errno = EAFNOSUPPORT;
85		return (NULL);
86	}
87	/* NOTREACHED */
88}
89
90/* const char *
91 * inet_ntop4(src, dst, size)
92 *	format an IPv4 address, more or less like inet_ntoa()
93 * return:
94 *	`dst' (as a const)
95 * notes:
96 *	(1) uses no statics
97 *	(2) takes a u_char* not an in_addr as input
98 * author:
99 *	Paul Vixie, 1996.
100 */
101static const char *
102inet_ntop4(const unsigned char *src, char *dst, apr_size_t size)
103{
104	const apr_size_t MIN_SIZE = 16; /* space for 255.255.255.255\0 */
105	int n = 0;
106	char *next = dst;
107
108	if (size < MIN_SIZE) {
109	    errno = ENOSPC;
110	    return NULL;
111	}
112	do {
113	    unsigned char u = *src++;
114	    if (u > 99) {
115		*next++ = '0' + u/100;
116		u %= 100;
117		*next++ = '0' + u/10;
118		u %= 10;
119	    }
120	    else if (u > 9) {
121		*next++ = '0' + u/10;
122		u %= 10;
123	    }
124	    *next++ = '0' + u;
125	    *next++ = '.';
126	    n++;
127	} while (n < 4);
128	*--next = 0;
129	return dst;
130}
131
132#if APR_HAVE_IPV6
133/* const char *
134 * inet_ntop6(src, dst, size)
135 *	convert IPv6 binary address into presentation (printable) format
136 * author:
137 *	Paul Vixie, 1996.
138 */
139static const char *
140inet_ntop6(const unsigned char *src, char *dst, apr_size_t size)
141{
142    /*
143     * Note that int32_t and int16_t need only be "at least" large enough
144     * to contain a value of the specified size.  On some systems, like
145     * Crays, there is no such thing as an integer variable with 16 bits.
146     * Keep this in mind if you think this function should have been coded
147     * to use pointer overlays.  All the world's not a VAX.
148     */
149    char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
150    struct { int base, len; } best = {-1, 0}, cur = {-1, 0};
151    unsigned int words[IN6ADDRSZ / INT16SZ];
152    int i;
153    const unsigned char *next_src, *src_end;
154    unsigned int *next_dest;
155
156    /*
157     * Preprocess:
158     *	Copy the input (bytewise) array into a wordwise array.
159     *	Find the longest run of 0x00's in src[] for :: shorthanding.
160     */
161    next_src = src;
162    src_end = src + IN6ADDRSZ;
163    next_dest = words;
164    i = 0;
165    do {
166        unsigned int next_word = (unsigned int)*next_src++;
167        next_word <<= 8;
168        next_word |= (unsigned int)*next_src++;
169        *next_dest++ = next_word;
170
171        if (next_word == 0) {
172            if (cur.base == -1) {
173                cur.base = i;
174                cur.len = 1;
175            }
176            else {
177                cur.len++;
178            }
179        } else {
180            if (cur.base != -1) {
181                if (best.base == -1 || cur.len > best.len) {
182                    best = cur;
183                }
184                cur.base = -1;
185            }
186        }
187
188        i++;
189    } while (next_src < src_end);
190
191    if (cur.base != -1) {
192        if (best.base == -1 || cur.len > best.len) {
193            best = cur;
194        }
195    }
196    if (best.base != -1 && best.len < 2) {
197        best.base = -1;
198    }
199
200    /*
201     * Format the result.
202     */
203    tp = tmp;
204    for (i = 0; i < (IN6ADDRSZ / INT16SZ);) {
205        /* Are we inside the best run of 0x00's? */
206        if (i == best.base) {
207            *tp++ = ':';
208            i += best.len;
209            continue;
210        }
211        /* Are we following an initial run of 0x00s or any real hex? */
212        if (i != 0) {
213            *tp++ = ':';
214        }
215        /* Is this address an encapsulated IPv4? */
216        if (i == 6 && best.base == 0 &&
217            (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
218            if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp))) {
219                return (NULL);
220            }
221            tp += strlen(tp);
222            break;
223        }
224        tp += apr_snprintf(tp, sizeof tmp - (tp - tmp), "%x", words[i]);
225        i++;
226    }
227    /* Was it a trailing run of 0x00's? */
228    if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ)) {
229        *tp++ = ':';
230    }
231    *tp++ = '\0';
232
233    /*
234     * Check for overflow, copy, and we're done.
235     */
236    if ((apr_size_t)(tp - tmp) > size) {
237        errno = ENOSPC;
238        return (NULL);
239    }
240    strcpy(dst, tmp);
241    return (dst);
242}
243#endif
244