lib/roken/inet_ntop.c

   1 /*
   2  * Copyright (c) 1999 - 2001 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <config.h>
  35
  36 #include "roken.h"
  37
  38 /*
  39  *
  40  */
  41
  42 static const char *
  43 inet_ntop_v4 (const void *src, char *dst, size_t size)
  44 {
  45     const char digits[] = "0123456789";
  46     int i;
  47     struct in_addr *addr = (struct in_addr *)src;
  48     u_long a = ntohl(addr->s_addr);
  49     const char *orig_dst = dst;
  50
  51     if (size < INET_ADDRSTRLEN) {
  52         errno = ENOSPC;
  53         return NULL;
  54     }
  55     for (i = 0; i < 4; ++i) {
  56         int n = (a >> (24 - i * 8)) & 0xFF;
  57         int non_zerop = 0;
  58
  59         if (non_zerop || n / 100 > 0) {
  60             *dst++ = digits[n / 100];
  61             n %= 100;
  62             non_zerop = 1;
  63         }
  64         if (non_zerop || n / 10 > 0) {
  65             *dst++ = digits[n / 10];
  66             n %= 10;
  67             non_zerop = 1;
  68         }
  69         *dst++ = digits[n];
  70         if (i != 3)
  71             *dst++ = '.';
  72     }
  73     *dst++ = '\0';
  74     return orig_dst;
  75 }
  76
  77 #ifdef HAVE_IPV6
  78 static const char *
  79 inet_ntop_v6 (const void *src, char *dst, size_t size)
  80 {
  81     const char xdigits[] = "0123456789abcdef";
  82     int i;
  83     const struct in6_addr *addr = (struct in6_addr *)src;
  84     const u_char *ptr = addr->s6_addr;
  85     const char *orig_dst = dst;
  86     int compressed = 0;
  87
  88     if (size < INET6_ADDRSTRLEN) {
  89         errno = ENOSPC;
  90         return NULL;
  91     }
  92     for (i = 0; i < 8; ++i) {
  93         int non_zerop = 0;
  94
  95         if (compressed == 0 &&
  96             ptr[0] == 0 && ptr[1] == 0 &&
  97             i <= 5 &&
  98             ptr[2] == 0 && ptr[3] == 0 &&
  99             ptr[4] == 0 && ptr[5] == 0) {
 100
 101             compressed = 1;
 102
 103             if (i == 0)
 104                 *dst++ = ':';
 105             *dst++ = ':';
 106
 107             for (ptr += 6, i += 3;
 108                  i < 8 && ptr[0] == 0 && ptr[1] == 0;
 109                  ++i, ptr += 2);
 110
 111             if (i >= 8)
 112                 break;
 113         }
 114
 115         if (non_zerop || (ptr[0] >> 4)) {
 116             *dst++ = xdigits[ptr[0] >> 4];
 117             non_zerop = 1;
 118         }
 119         if (non_zerop || (ptr[0] & 0x0F)) {
 120             *dst++ = xdigits[ptr[0] & 0x0F];
 121             non_zerop = 1;
 122         }
 123         if (non_zerop || (ptr[1] >> 4)) {
 124             *dst++ = xdigits[ptr[1] >> 4];
 125             non_zerop = 1;
 126         }
 127         *dst++ = xdigits[ptr[1] & 0x0F];
 128         if (i != 7)
 129             *dst++ = ':';
 130         ptr += 2;
 131     }
 132     *dst++ = '\0';
 133     return orig_dst;
 134 }
 135 #endif /* HAVE_IPV6 */
 136
 137 ROKEN_LIB_FUNCTION const char * ROKEN_LIB_CALL
 138 inet_ntop(int af, const void *src, char *dst, size_t size)
 139 {
 140     switch (af) {
 141     case AF_INET :
 142         return inet_ntop_v4 (src, dst, size);
 143 #ifdef HAVE_IPV6
 144     case AF_INET6 :
 145         return inet_ntop_v6 (src, dst, size);
 146 #endif
 147     default :
 148         errno = EAFNOSUPPORT;
 149         return NULL;
 150     }
 151 }