Utilities/cmcurl/inet_ntop.c

   1 /*
   2  * Copyright (C) 1996-2001  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
   9  * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
  10  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
  11  * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
  13  * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
  14  * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
  15  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17 /*
  18  * Original code by Paul Vixie. "curlified" by Gisle Vanem.
  19  */
  20
  21 #include "setup.h"
  22
  23 #ifndef HAVE_INET_NTOP
  24
  25 #ifdef HAVE_SYS_PARAM_H
  26 #include <sys/param.h>
  27 #endif
  28 #ifdef HAVE_SYS_TYPES_H
  29 #include <sys/types.h>
  30 #endif
  31 #ifdef HAVE_SYS_SOCKET_H
  32 #include <sys/socket.h>
  33 #endif
  34 #ifdef HAVE_NETINET_IN_H
  35 #include <netinet/in.h>
  36 #endif
  37 #ifdef HAVE_ARPA_INET_H
  38 #include <arpa/inet.h>
  39 #endif
  40 #include <string.h>
  41 #include <errno.h>
  42
  43 #define _MPRINTF_REPLACE /* use our functions only */
  44 #include <curl/mprintf.h>
  45
  46 #include "inet_ntop.h"
  47
  48 #if defined(HAVE_INET_NTOA_R) && !defined(HAVE_INET_NTOA_R_DECL)
  49 /* this platform has a inet_ntoa_r() function, but no proto declared anywhere
  50    so we include our own proto to make compilers happy */
  51 #include "inet_ntoa_r.h"
  52 #endif
  53
  54 #define IN6ADDRSZ       16
  55 #define INADDRSZ         4
  56 #define INT16SZ          2
  57
  58 #ifdef USE_WINSOCK
  59 #define EAFNOSUPPORT    WSAEAFNOSUPPORT
  60 #define SET_ERRNO(e)    WSASetLastError(errno = (e))
  61 #else
  62 #define SET_ERRNO(e)    errno = e
  63 #endif
  64
  65 /*
  66  * Format an IPv4 address, more or less like inet_ntoa().
  67  *
  68  * Returns `dst' (as a const)
  69  * Note:
  70  *  - uses no statics
  71  *  - takes a unsigned char* not an in_addr as input
  72  */
  73 static char *inet_ntop4 (const unsigned char *src, char *dst, size_t size)
  74 {
  75 #if defined(HAVE_INET_NTOA_R_2_ARGS)
  76   const char *ptr;
  77   curlassert(size >= 16);
  78   ptr = inet_ntoa_r(*(struct in_addr*)src, dst);
  79   return (char *)memmove(dst, ptr, strlen(ptr)+1);
  80
  81 #elif defined(HAVE_INET_NTOA_R)
  82   return inet_ntoa_r(*(struct in_addr*)src, dst, size);
  83
  84 #else
  85   const char *addr = inet_ntoa(*(struct in_addr*)src);
  86
  87   if (strlen(addr) >= size)
  88   {
  89     SET_ERRNO(ENOSPC);
  90     return (NULL);
  91   }
  92   return strcpy(dst, addr);
  93 #endif
  94 }
  95
  96 #ifdef ENABLE_IPV6
  97 /*
  98  * Convert IPv6 binary address into presentation (printable) format.
  99  */
 100 static char *inet_ntop6 (const unsigned char *src, char *dst, size_t size)
 101 {
 102   /*
 103    * Note that int32_t and int16_t need only be "at least" large enough
 104    * to contain a value of the specified size.  On some systems, like
 105    * Crays, there is no such thing as an integer variable with 16 bits.
 106    * Keep this in mind if you think this function should have been coded
 107    * to use pointer overlays.  All the world's not a VAX.
 108    */
 109   char tmp[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")];
 110   char *tp;
 111   struct {
 112     long base;
 113     long len;
 114   } best, cur;
 115   unsigned long words[IN6ADDRSZ / INT16SZ];
 116   int i;
 117
 118   /* Preprocess:
 119    *  Copy the input (bytewise) array into a wordwise array.
 120    *  Find the longest run of 0x00's in src[] for :: shorthanding.
 121    */
 122   memset(words, '\0', sizeof(words));
 123   for (i = 0; i < IN6ADDRSZ; i++)
 124       words[i/2] |= (src[i] << ((1 - (i % 2)) << 3));
 125
 126   best.base = -1;
 127   cur.base  = -1;
 128   best.len = 0;
 129   cur.len = 0;
 130
 131   for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++)
 132   {
 133     if (words[i] == 0)
 134     {
 135       if (cur.base == -1)
 136         cur.base = i, cur.len = 1;
 137       else
 138         cur.len++;
 139     }
 140     else if (cur.base != -1)
 141     {
 142       if (best.base == -1 || cur.len > best.len)
 143          best = cur;
 144       cur.base = -1;
 145     }
 146   }
 147   if ((cur.base != -1) && (best.base == -1 || cur.len > best.len))
 148      best = cur;
 149   if (best.base != -1 && best.len < 2)
 150      best.base = -1;
 151
 152   /* Format the result.
 153    */
 154   tp = tmp;
 155   for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++)
 156   {
 157     /* Are we inside the best run of 0x00's?
 158      */
 159     if (best.base != -1 && i >= best.base && i < (best.base + best.len))
 160     {
 161       if (i == best.base)
 162          *tp++ = ':';
 163       continue;
 164     }
 165
 166     /* Are we following an initial run of 0x00s or any real hex?
 167      */
 168     if (i != 0)
 169        *tp++ = ':';
 170
 171     /* Is this address an encapsulated IPv4?
 172      */
 173     if (i == 6 && best.base == 0 &&
 174         (best.len == 6 || (best.len == 5 && words[5] == 0xffff)))
 175     {
 176       if (!inet_ntop4(src+12, tp, sizeof(tmp) - (tp - tmp)))
 177       {
 178         SET_ERRNO(ENOSPC);
 179         return (NULL);
 180       }
 181       tp += strlen(tp);
 182       break;
 183     }
 184     tp += snprintf(tp, 5, "%lx", words[i]);
 185   }
 186
 187   /* Was it a trailing run of 0x00's?
 188    */
 189   if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ))
 190      *tp++ = ':';
 191   *tp++ = '\0';
 192
 193   /* Check for overflow, copy, and we're done.
 194    */
 195   if ((size_t)(tp - tmp) > size)
 196   {
 197     SET_ERRNO(ENOSPC);
 198     return (NULL);
 199   }
 200   return strcpy (dst, tmp);
 201 }
 202 #endif  /* ENABLE_IPV6 */
 203
 204 /*
 205  * Convert a network format address to presentation format.
 206  *
 207  * Returns pointer to presentation format address (`buf'),
 208  * Returns NULL on error (see errno).
 209  */
 210 char *Curl_inet_ntop(int af, const void *src, char *buf, size_t size)
 211 {
 212   switch (af) {
 213   case AF_INET:
 214     return inet_ntop4((const unsigned char*)src, buf, size);
 215 #ifdef ENABLE_IPV6
 216   case AF_INET6:
 217     return inet_ntop6((const unsigned char*)src, buf, size);
 218 #endif
 219   default:
 220     SET_ERRNO(EAFNOSUPPORT);
 221     return NULL;
 222   }
 223 }
 224 #endif  /* HAVE_INET_NTOP */