reactos/dll/win32/wininet/inet_ntop.c

   1 /* from NetBSD: inet_ntop.c,v 1.9 2000/01/22 22:19:16 mycroft Exp */
   2
   3 /* Copyright (c) 1996 by Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
  10  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  11  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  12  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  13  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  14  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  15  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  16  * SOFTWARE.
  17  */
  18
  19 #ifndef IN6ADDRSZ
  20 #define IN6ADDRSZ       16
  21 #endif
  22
  23 #ifndef INT16SZ
  24 #define INT16SZ         2
  25 #endif
  26
  27 #ifdef SPRINTF_CHAR
  28 # define SPRINTF(x) strlen(sprintf/**/x)
  29 #else
  30 # define SPRINTF(x) ((socklen_t)sprintf x)
  31 #endif
  32
  33 /*
  34  * WARNING: Don't even consider trying to compile this on a system where
  35  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
  36  */
  37
  38 static const char *inet_ntop4(const u_char *src, char *dst, socklen_t size);
  39
  40 #ifdef INET6
  41 static const char *inet_ntop6(const u_char *src, char *dst, socklen_t size);
  42 #endif
  43
  44 /* char *
  45  * inet_ntop(af, src, dst, size)
  46  *      convert a network format address to presentation format.
  47  * return:
  48  *      pointer to presentation format address (`dst'), or NULL (see errno).
  49  * author:
  50  *      Paul Vixie, 1996.
  51  */
  52 const char *
  53 inet_ntop(int af, const void *src, char *dst, socklen_t size)
  54 {
  55
  56         switch (af) {
  57         case AF_INET:
  58                 return (inet_ntop4(src, dst, size));
  59 #ifdef INET6
  60         case AF_INET6:
  61                 return (inet_ntop6(src, dst, size));
  62 #endif
  63         default:
  64                 WSASetLastError(WSAEAFNOSUPPORT);
  65                 return (NULL);
  66         }
  67         /* NOTREACHED */
  68 }
  69
  70 /* const char *
  71  * inet_ntop4(src, dst, size)
  72  *      format an IPv4 address, more or less like inet_ntoa()
  73  * return:
  74  *      `dst' (as a const)
  75  * notes:
  76  *      (1) uses no statics
  77  *      (2) takes a u_char* not an in_addr as input
  78  * author:
  79  *      Paul Vixie, 1996.
  80  */
  81 static const char *
  82 inet_ntop4(const u_char *src, char *dst, socklen_t size)
  83 {
  84         static const char fmt[] = "%u.%u.%u.%u";
  85         char tmp[sizeof "255.255.255.255"];
  86
  87         if (SPRINTF((tmp, fmt, src[0], src[1], src[2], src[3])) > size) {
  88                 WSASetLastError(WSAEINVAL);
  89                 return (NULL);
  90         }
  91         strcpy(dst, tmp);
  92         return (dst);
  93 }
  94
  95 #ifdef INET6
  96 /* const char *
  97  * inet_ntop6(src, dst, size)
  98  *      convert IPv6 binary address into presentation (printable) format
  99  * author:
 100  *      Paul Vixie, 1996.
 101  */
 102 static const char *
 103 inet_ntop6(const u_char *src, char *dst, socklen_t size)
 104 {
 105         /*
 106          * Note that int32_t and int16_t need only be "at least" large enough
 107          * to contain a value of the specified size.  On some systems, like
 108          * Crays, there is no such thing as an integer variable with 16 bits.
 109          * Keep this in mind if you think this function should have been coded
 110          * to use pointer overlays.  All the world's not a VAX.
 111          */
 112         char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
 113         struct { int base, len; } best, cur;
 114         u_int words[IN6ADDRSZ / INT16SZ];
 115         int i;
 116
 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         best.base = -1;
 126         cur.base = -1;
 127         for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
 128                 if (words[i] == 0) {
 129                         if (cur.base == -1)
 130                                 cur.base = i, cur.len = 1;
 131                         else
 132                                 cur.len++;
 133                 } else {
 134                         if (cur.base != -1) {
 135                                 if (best.base == -1 || cur.len > best.len)
 136                                         best = cur;
 137                                 cur.base = -1;
 138                         }
 139                 }
 140         }
 141         if (cur.base != -1) {
 142                 if (best.base == -1 || cur.len > best.len)
 143                         best = cur;
 144         }
 145         if (best.base != -1 && best.len < 2)
 146                 best.base = -1;
 147
 148         /*
 149          * Format the result.
 150          */
 151         tp = tmp;
 152         for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
 153                 /* Are we inside the best run of 0x00's? */
 154                 if (best.base != -1 && i >= best.base &&
 155                     i < (best.base + best.len)) {
 156                         if (i == best.base)
 157                                 *tp++ = ':';
 158                         continue;
 159                 }
 160                 /* Are we following an initial run of 0x00s or any real hex? */
 161                 if (i != 0)
 162                         *tp++ = ':';
 163                 /* Is this address an encapsulated IPv4? */
 164                 if (i == 6 && best.base == 0 &&
 165                     (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
 166                         if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp)))
 167                                 return (NULL);
 168                         tp += strlen(tp);
 169                         break;
 170                 }
 171                 tp += SPRINTF((tp, "%x", words[i]));
 172         }
 173         /* Was it a trailing run of 0x00's? */
 174         if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ))
 175                 *tp++ = ':';
 176         *tp++ = '\0';
 177
 178         /*
 179          * Check for overflow, copy, and we're done.
 180          */
 181         if ((socklen_t)(tp - tmp) > size) {
 182                 WSASetLastError(WSAEINVAL);
 183                 return (NULL);
 184         }
 185         strcpy(dst, tmp);
 186         return (dst);
 187 }
 188 #endif
 189