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 <netinet/in.h>
  22#include <arpa/inet.h>
  23#include <stdio.h>
  24#include <string.h>
  25
  26#ifndef NS_INADDRSZ
  27#define NS_INADDRSZ     4
  28#endif
  29#ifndef NS_IN6ADDRSZ
  30#define NS_IN6ADDRSZ    16
  31#endif
  32#ifndef NS_INT16SZ
  33#define NS_INT16SZ      2
  34#endif
  35
  36/*
  37 * WARNING: Don't even consider trying to compile this on a system where
  38 * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
  39 */
  40
  41/* const char *
  42 * inet_ntop4(src, dst, size)
  43 *      format an IPv4 address
  44 * return:
  45 *      `dst' (as a const)
  46 * notes:
  47 *      (1) uses no statics
  48 *      (2) takes a u_char* not an in_addr as input
  49 * author:
  50 *      Paul Vixie, 1996.
  51 */
  52static const char *
  53inet_ntop4(src, dst, size)
  54        const u_char *src;
  55        char *dst;
  56        size_t size;
  57{
  58        static const char fmt[] = "%u.%u.%u.%u";
  59        char tmp[sizeof "255.255.255.255"];
  60        int nprinted;
  61
  62        nprinted = snprintf(tmp, sizeof(tmp), fmt, src[0], src[1], src[2], src[3]);
  63        if (nprinted < 0)
  64                return (NULL);  /* we assume "errno" was set by "snprintf()" */
  65        if ((size_t)nprinted > size) {
  66                errno = ENOSPC;
  67                return (NULL);
  68        }
  69        strcpy(dst, tmp);
  70        return (dst);
  71}
  72
  73#ifndef NO_IPV6
  74/* const char *
  75 * inet_ntop6(src, dst, size)
  76 *      convert IPv6 binary address into presentation (printable) format
  77 * author:
  78 *      Paul Vixie, 1996.
  79 */
  80static const char *
  81inet_ntop6(src, dst, size)
  82        const u_char *src;
  83        char *dst;
  84        size_t size;
  85{
  86        /*
  87         * Note that int32_t and int16_t need only be "at least" large enough
  88         * to contain a value of the specified size.  On some systems, like
  89         * Crays, there is no such thing as an integer variable with 16 bits.
  90         * Keep this in mind if you think this function should have been coded
  91         * to use pointer overlays.  All the world's not a VAX.
  92         */
  93        char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
  94        struct { int base, len; } best, cur;
  95        unsigned int words[NS_IN6ADDRSZ / NS_INT16SZ];
  96        int i;
  97
  98        /*
  99         * Preprocess:
 100         *      Copy the input (bytewise) array into a wordwise array.
 101         *      Find the longest run of 0x00's in src[] for :: shorthanding.
 102         */
 103        memset(words, '\0', sizeof words);
 104        for (i = 0; i < NS_IN6ADDRSZ; i++)
 105                words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
 106        best.base = -1;
 107        cur.base = -1;
 108        for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
 109                if (words[i] == 0) {
 110                        if (cur.base == -1)
 111                                cur.base = i, cur.len = 1;
 112                        else
 113                                cur.len++;
 114                } else {
 115                        if (cur.base != -1) {
 116                                if (best.base == -1 || cur.len > best.len)
 117                                        best = cur;
 118                                cur.base = -1;
 119                        }
 120                }
 121        }
 122        if (cur.base != -1) {
 123                if (best.base == -1 || cur.len > best.len)
 124                        best = cur;
 125        }
 126        if (best.base != -1 && best.len < 2)
 127                best.base = -1;
 128
 129        /*
 130         * Format the result.
 131         */
 132        tp = tmp;
 133        for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
 134                /* Are we inside the best run of 0x00's? */
 135                if (best.base != -1 && i >= best.base &&
 136                    i < (best.base + best.len)) {
 137                        if (i == best.base)
 138                                *tp++ = ':';
 139                        continue;
 140                }
 141                /* Are we following an initial run of 0x00s or any real hex? */
 142                if (i != 0)
 143                        *tp++ = ':';
 144                /* Is this address an encapsulated IPv4? */
 145                if (i == 6 && best.base == 0 &&
 146                    (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
 147                        if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp)))
 148                                return (NULL);
 149                        tp += strlen(tp);
 150                        break;
 151                }
 152                tp += snprintf(tp, sizeof tmp - (tp - tmp), "%x", words[i]);
 153        }
 154        /* Was it a trailing run of 0x00's? */
 155        if (best.base != -1 && (best.base + best.len) ==
 156            (NS_IN6ADDRSZ / NS_INT16SZ))
 157                *tp++ = ':';
 158        *tp++ = '\0';
 159
 160        /*
 161         * Check for overflow, copy, and we're done.
 162         */
 163        if ((size_t)(tp - tmp) > size) {
 164                errno = ENOSPC;
 165                return (NULL);
 166        }
 167        strcpy(dst, tmp);
 168        return (dst);
 169}
 170#endif
 171
 172/* char *
 173 * inet_ntop(af, src, dst, size)
 174 *      convert a network format address to presentation format.
 175 * return:
 176 *      pointer to presentation format address (`dst'), or NULL (see errno).
 177 * author:
 178 *      Paul Vixie, 1996.
 179 */
 180const char *
 181inet_ntop(af, src, dst, size)
 182        int af;
 183        const void *src;
 184        char *dst;
 185        size_t size;
 186{
 187        switch (af) {
 188        case AF_INET:
 189                return (inet_ntop4(src, dst, size));
 190#ifndef NO_IPV6
 191        case AF_INET6:
 192                return (inet_ntop6(src, dst, size));
 193#endif
 194        default:
 195                errno = EAFNOSUPPORT;
 196                return (NULL);
 197        }
 198        /* NOTREACHED */
 199}