dll/win32/winhttp/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 #include <stdio.h>
  20
  21 #ifndef IN6ADDRSZ
  22 #define IN6ADDRSZ       16
  23 #endif
  24
  25 #ifndef INT16SZ
  26 #define INT16SZ         2
  27 #endif
  28
  29 #ifdef SPRINTF_CHAR
  30 # define SPRINTF(x) strlen(sprintf/**/x)
  31 #else
  32 # define SPRINTF(x) ((size_t)sprintf x)
  33 #endif
  34
  35 /*
  36  * WARNING: Don't even consider trying to compile this on a system where
  37  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
  38  */
  39
  40 static const char *inet_ntop4(const u_char *src, char *dst, size_t size);
  41
  42 #ifdef INET6
  43 static const char *inet_ntop6(const u_char *src, char *dst, size_t size);
  44 #endif
  45
  46 /* char *
  47  * inet_ntop(af, src, dst, size)
  48  *      convert a network format address to presentation format.
  49  * return:
  50  *      pointer to presentation format address (`dst'), or NULL (see errno).
  51  * author:
  52  *      Paul Vixie, 1996.
  53  */
  54
  55 PCSTR
  56 WSAAPI
  57 inet_ntop(INT Family, PVOID pAddr, PSTR pStringBuf, size_t StringBufSize)
  58 {
  59
  60         switch (Family) {
  61         case AF_INET:
  62                 return (inet_ntop4(pAddr, pStringBuf, StringBufSize));
  63 #ifdef INET6
  64         case AF_INET6:
  65                 return (inet_ntop6(pAddr, pStringBuf, StringBufSize));
  66 #endif
  67         default:
  68                 WSASetLastError(WSAEAFNOSUPPORT);
  69                 return (NULL);
  70         }
  71         /* NOTREACHED */
  72 }
  73
  74 /* const char *
  75  * inet_ntop4(src, dst, size)
  76  *      format an IPv4 address, more or less like inet_ntoa()
  77  * return:
  78  *      `dst' (as a const)
  79  * notes:
  80  *      (1) uses no statics
  81  *      (2) takes a u_char* not an in_addr as input
  82  * author:
  83  *      Paul Vixie, 1996.
  84  */
  85 static const char *
  86 inet_ntop4(const u_char *src, char *dst, size_t size)
  87 {
  88         static const char fmt[] = "%u.%u.%u.%u";
  89         char tmp[sizeof "255.255.255.255"];
  90
  91         if (SPRINTF((tmp, fmt, src[0], src[1], src[2], src[3])) > size) {
  92                 WSASetLastError(WSAEINVAL);
  93                 return (NULL);
  94         }
  95         strcpy(dst, tmp);
  96         return (dst);
  97 }
  98
  99 #ifdef INET6
 100 /* const char *
 101  * inet_ntop6(src, dst, size)
 102  *      convert IPv6 binary address into presentation (printable) format
 103  * author:
 104  *      Paul Vixie, 1996.
 105  */
 106 static const char *
 107 inet_ntop6(const u_char *src, char *dst, size_t size)
 108 {
 109         /*
 110          * Note that int32_t and int16_t need only be "at least" large enough
 111          * to contain a value of the specified size.  On some systems, like
 112          * Crays, there is no such thing as an integer variable with 16 bits.
 113          * Keep this in mind if you think this function should have been coded
 114          * to use pointer overlays.  All the world's not a VAX.
 115          */
 116         char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
 117         struct { int base, len; } best, cur;
 118         u_int words[IN6ADDRSZ / INT16SZ];
 119         int i;
 120
 121         /*
 122          * Preprocess:
 123          *      Copy the input (bytewise) array into a wordwise array.
 124          *      Find the longest run of 0x00's in src[] for :: shorthanding.
 125          */
 126         memset(words, '\0', sizeof words);
 127         for (i = 0; i < IN6ADDRSZ; i++)
 128                 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
 129         best.base = -1;
 130         cur.base = -1;
 131         for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
 132                 if (words[i] == 0) {
 133                         if (cur.base == -1)
 134                                 cur.base = i, cur.len = 1;
 135                         else
 136                                 cur.len++;
 137                 } else {
 138                         if (cur.base != -1) {
 139                                 if (best.base == -1 || cur.len > best.len)
 140                                         best = cur;
 141                                 cur.base = -1;
 142                         }
 143                 }
 144         }
 145         if (cur.base != -1) {
 146                 if (best.base == -1 || cur.len > best.len)
 147                         best = cur;
 148         }
 149         if (best.base != -1 && best.len < 2)
 150                 best.base = -1;
 151
 152         /*
 153          * Format the result.
 154          */
 155         tp = tmp;
 156         for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
 157                 /* Are we inside the best run of 0x00's? */
 158                 if (best.base != -1 && i >= best.base &&
 159                     i < (best.base + best.len)) {
 160                         if (i == best.base)
 161                                 *tp++ = ':';
 162                         continue;
 163                 }
 164                 /* Are we following an initial run of 0x00s or any real hex? */
 165                 if (i != 0)
 166                         *tp++ = ':';
 167                 /* Is this address an encapsulated IPv4? */
 168                 if (i == 6 && best.base == 0 &&
 169                     (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
 170                         if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp)))
 171                                 return (NULL);
 172                         tp += strlen(tp);
 173                         break;
 174                 }
 175                 tp += SPRINTF((tp, "%x", words[i]));
 176         }
 177         /* Was it a trailing run of 0x00's? */
 178         if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ))
 179                 *tp++ = ':';
 180         *tp++ = '\0';
 181
 182         /*
 183          * Check for overflow, copy, and we're done.
 184          */
 185         if ((size_t)(tp - tmp) > size) {
 186                 WSASetLastError(WSAEINVAL);
 187                 return (NULL);
 188         }
 189         strcpy(dst, tmp);
 190         return (dst);
 191 }
 192 #endif
 193