Andrew's git - gitweb.git/blob - compat/inet

   1/*
   2 * Copyright (c) 1996-1999 by Internet Software Consortium.
   3 *
   4 * Permission to use, copy, modify, and distribute this software for any
   5 * purpose with or without fee is hereby granted, provided that the above
   6 * copyright notice and this permission notice appear in all copies.
   7 *
   8 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
   9 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  10 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  11 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  12 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  13 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  14 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  15 * SOFTWARE.
  16 */
  17
  18#include <errno.h>
  19#include <sys/types.h>
  20#include <sys/socket.h>
  21#include <sys/socket.h>
  22#include <netinet/in.h>
  23#include <arpa/inet.h>
  24#include <stdio.h>
  25#include <string.h>
  26
  27#ifndef NS_INADDRSZ
  28#define NS_INADDRSZ     4
  29#endif
  30#ifndef NS_IN6ADDRSZ
  31#define NS_IN6ADDRSZ    16
  32#endif
  33#ifndef NS_INT16SZ
  34#define NS_INT16SZ      2
  35#endif
  36
  37/*
  38 * WARNING: Don't even consider trying to compile this on a system where
  39 * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
  40 */
  41
  42/* const char *
  43 * inet_ntop4(src, dst, size)
  44 *      format an IPv4 address
  45 * return:
  46 *      `dst' (as a const)
  47 * notes:
  48 *      (1) uses no statics
  49 *      (2) takes a u_char* not an in_addr as input
  50 * author:
  51 *      Paul Vixie, 1996.
  52 */
  53static const char *
  54inet_ntop4(src, dst, size)
  55        const u_char *src;
  56        char *dst;
  57        size_t size;
  58{
  59        static const char fmt[] = "%u.%u.%u.%u";
  60        char tmp[sizeof "255.255.255.255"];
  61        int nprinted;
  62
  63        nprinted = snprintf(tmp, sizeof(tmp), fmt, src[0], src[1], src[2], src[3]);
  64        if (nprinted < 0)
  65                return (NULL);  /* we assume "errno" was set by "snprintf()" */
  66        if ((size_t)nprinted > size) {
  67                errno = ENOSPC;
  68                return (NULL);
  69        }
  70        strcpy(dst, tmp);
  71        return (dst);
  72}
  73
  74#ifndef NO_IPV6
  75/* const char *
  76 * inet_ntop6(src, dst, size)
  77 *      convert IPv6 binary address into presentation (printable) format
  78 * author:
  79 *      Paul Vixie, 1996.
  80 */
  81static const char *
  82inet_ntop6(src, dst, size)
  83        const u_char *src;
  84        char *dst;
  85        size_t size;
  86{
  87        /*
  88         * Note that int32_t and int16_t need only be "at least" large enough
  89         * to contain a value of the specified size.  On some systems, like
  90         * Crays, there is no such thing as an integer variable with 16 bits.
  91         * Keep this in mind if you think this function should have been coded
  92         * to use pointer overlays.  All the world's not a VAX.
  93         */
  94        char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
  95        struct { int base, len; } best, cur;
  96        unsigned int words[NS_IN6ADDRSZ / NS_INT16SZ];
  97        int i;
  98
  99        /*
 100         * Preprocess:
 101         *      Copy the input (bytewise) array into a wordwise array.
 102         *      Find the longest run of 0x00's in src[] for :: shorthanding.
 103         */
 104        memset(words, '\0', sizeof words);
 105        for (i = 0; i < NS_IN6ADDRSZ; i++)
 106                words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
 107        best.base = -1;
 108        cur.base = -1;
 109        for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
 110                if (words[i] == 0) {
 111                        if (cur.base == -1)
 112                                cur.base = i, cur.len = 1;
 113                        else
 114                                cur.len++;
 115                } else {
 116                        if (cur.base != -1) {
 117                                if (best.base == -1 || cur.len > best.len)
 118                                        best = cur;
 119                                cur.base = -1;
 120                        }
 121                }
 122        }
 123        if (cur.base != -1) {
 124                if (best.base == -1 || cur.len > best.len)
 125                        best = cur;
 126        }
 127        if (best.base != -1 && best.len < 2)
 128                best.base = -1;
 129
 130        /*
 131         * Format the result.
 132         */
 133        tp = tmp;
 134        for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
 135                /* Are we inside the best run of 0x00's? */
 136                if (best.base != -1 && i >= best.base &&
 137                    i < (best.base + best.len)) {
 138                        if (i == best.base)
 139                                *tp++ = ':';
 140                        continue;
 141                }
 142                /* Are we following an initial run of 0x00s or any real hex? */
 143                if (i != 0)
 144                        *tp++ = ':';
 145                /* Is this address an encapsulated IPv4? */
 146                if (i == 6 && best.base == 0 &&
 147                    (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
 148                        if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp)))
 149                                return (NULL);
 150                        tp += strlen(tp);
 151                        break;
 152                }
 153                tp += snprintf(tp, sizeof tmp - (tp - tmp), "%x", words[i]);
 154        }
 155        /* Was it a trailing run of 0x00's? */
 156        if (best.base != -1 && (best.base + best.len) ==
 157            (NS_IN6ADDRSZ / NS_INT16SZ))
 158                *tp++ = ':';
 159        *tp++ = '\0';
 160
 161        /*
 162         * Check for overflow, copy, and we're done.
 163         */
 164        if ((size_t)(tp - tmp) > size) {
 165                errno = ENOSPC;
 166                return (NULL);
 167        }
 168        strcpy(dst, tmp);
 169        return (dst);
 170}
 171#endif
 172
 173/* char *
 174 * inet_ntop(af, src, dst, size)
 175 *      convert a network format address to presentation format.
 176 * return:
 177 *      pointer to presentation format address (`dst'), or NULL (see errno).
 178 * author:
 179 *      Paul Vixie, 1996.
 180 */
 181const char *
 182inet_ntop(af, src, dst, size)
 183        int af;
 184        const void *src;
 185        char *dst;
 186        size_t size;
 187{
 188        switch (af) {
 189        case AF_INET:
 190                return (inet_ntop4(src, dst, size));
 191#ifndef NO_IPV6
 192        case AF_INET6:
 193                return (inet_ntop6(src, dst, size));
 194#endif
 195        default:
 196                errno = EAFNOSUPPORT;
 197                return (NULL);
 198        }
 199        /* NOTREACHED */
 200}