workbench/network/stacks/AROSTCP/bsdsocket/api/inet_ntop.c

   1 /* Copyright (c) 1996 by Internet Software Consortium.
   2  * Copyright (c) 2005 by Pavel Fedin
   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 <amitcp/socketbasetags.h>
  19 #include <emul/emulregs.h>
  20 #include <proto/socket.h>
  21 #include <sys/cdefs.h>
  22 #include <sys/param.h>
  23 #include <sys/types.h>
  24 #include <sys/socket.h>
  25 #include <netinet/in.h>
  26 #include <arpa/inet.h>
  27 #include <arpa/nameser.h>
  28 #include <errno.h>
  29 #include <stdio.h>
  30 #include <string.h>
  31
  32 /*
  33  * WARNING: Don't even consider trying to compile this on a system where
  34  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
  35  */
  36
  37 static const char *inet_ntop4(const u_char *src, char *dst, socklen_t size);
  38 static const char *inet_ntop6(const u_char *src, char *dst, socklen_t size);
  39
  40 /* char *
  41  * inet_ntop(af, src, dst, size)
  42  *      convert a network format address to presentation format.
  43  * return:
  44  *      pointer to presentation format address (`dst'), or NULL (see errno).
  45  * author:
  46  *      Paul Vixie, 1996.
  47  */
  48 const char *
  49 inet_ntop(void)
  50 {
  51         int af = REG_D0;
  52         const void * __restrict src = (const void *)REG_A0;
  53         char * __restrict dst = (char *)REG_A1;
  54         socklen_t size = (socklen_t)REG_D1;
  55
  56         switch (af) {
  57         case AF_INET:
  58                 return (inet_ntop4(src, dst, size));
  59         case AF_INET6:
  60                 return (inet_ntop6(src, dst, size));
  61         default:
  62                 SocketBaseTags(SBTM_SETVAL(SBTC_ERRNO),EAFNOSUPPORT,TAG_DONE);
  63                 return (NULL);
  64         }
  65         /* NOTREACHED */
  66 }
  67
  68 /* const char *
  69  * inet_ntop4(src, dst, size)
  70  *      format an IPv4 address, more or less like inet_ntoa()
  71  * return:
  72  *      `dst' (as a const)
  73  * notes:
  74  *      (1) uses no statics
  75  *      (2) takes a u_char* not an in_addr as input
  76  * author:
  77  *      Paul Vixie, 1996.
  78  */
  79 static const char *
  80 inet_ntop4(const u_char *src, char *dst, socklen_t size)
  81 {
  82         static const char fmt[] = "%u.%u.%u.%u";
  83
  84         if ((socklen_t)snprintf(dst, size, fmt, src[0], src[1], src[2], src[3])
  85             >= size) {
  86                 SocketBaseTags(SBTM_SETVAL(SBTC_ERRNO),ENOSPC,TAG_DONE);
  87                 return (NULL);
  88         }
  89         return (dst);
  90 }
  91
  92 /* const char *
  93  * inet_ntop6(src, dst, size)
  94  *      convert IPv6 binary address into presentation (printable) format
  95  * author:
  96  *      Paul Vixie, 1996.
  97  */
  98 static const char *
  99 inet_ntop6(const u_char *src, char *dst, socklen_t size)
 100 {
 101         /*
 102          * Note that int32_t and int16_t need only be "at least" large enough
 103          * to contain a value of the specified size.  On some systems, like
 104          * Crays, there is no such thing as an integer variable with 16 bits.
 105          * Keep this in mind if you think this function should have been coded
 106          * to use pointer overlays.  All the world's not a VAX.
 107          */
 108         char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
 109         struct { int base, len; } best, cur;
 110         u_int words[NS_IN6ADDRSZ / NS_INT16SZ];
 111         int i;
 112
 113         /*
 114          * Preprocess:
 115          *      Copy the input (bytewise) array into a wordwise array.
 116          *      Find the longest run of 0x00's in src[] for :: shorthanding.
 117          */
 118         memset(words, '\0', sizeof words);
 119         for (i = 0; i < NS_IN6ADDRSZ; i++)
 120                 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
 121         best.base = -1;
 122         cur.base = -1;
 123         for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
 124                 if (words[i] == 0) {
 125                         if (cur.base == -1)
 126                                 cur.base = i, cur.len = 1;
 127                         else
 128                                 cur.len++;
 129                 } else {
 130                         if (cur.base != -1) {
 131                                 if (best.base == -1 || cur.len > best.len)
 132                                         best = cur;
 133                                 cur.base = -1;
 134                         }
 135                 }
 136         }
 137         if (cur.base != -1) {
 138                 if (best.base == -1 || cur.len > best.len)
 139                         best = cur;
 140         }
 141         if (best.base != -1 && best.len < 2)
 142                 best.base = -1;
 143
 144         /*
 145          * Format the result.
 146          */
 147         tp = tmp;
 148         for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
 149                 /* Are we inside the best run of 0x00's? */
 150                 if (best.base != -1 && i >= best.base &&
 151                     i < (best.base + best.len)) {
 152                         if (i == best.base)
 153                                 *tp++ = ':';
 154                         continue;
 155                 }
 156                 /* Are we following an initial run of 0x00s or any real hex? */
 157                 if (i != 0)
 158                         *tp++ = ':';
 159                 /* Is this address an encapsulated IPv4? */
 160                 if (i == 6 && best.base == 0 &&
 161                     (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
 162                         if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp)))
 163                                 return (NULL);
 164                         tp += strlen(tp);
 165                         break;
 166                 }
 167                 tp += sprintf(tp, "%x", words[i]);
 168         }
 169         /* Was it a trailing run of 0x00's? */
 170         if (best.base != -1 && (best.base + best.len) ==
 171             (NS_IN6ADDRSZ / NS_INT16SZ))
 172                 *tp++ = ':';
 173         *tp++ = '\0';
 174
 175         /*
 176          * Check for overflow, copy, and we're done.
 177          */
 178         if ((socklen_t)(tp - tmp) > size) {
 179                 SocketBaseTags(SBTM_SETVAL(SBTC_ERRNO),ENOSPC,TAG_DONE);
 180                 return (NULL);
 181         }
 182         strcpy(dst, tmp);
 183         return (dst);
 184 }