compat/inet_ntop.cc

   1 /*
   2  * Copyright (C) 1996-2015 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /*
  10  *  Shamelessly duplicated from the bind9 public sources
  11  *  for use by the Squid Project under ISC written permission
  12  *  included "as found" below.
  13  *
  14  * Update/Maintenance History:
  15  *
  16  *    24-Sep-2007 : Copied from bind 9.3.3
  17  *          - Added protection around libray headers
  18  *          - Altered configure checks
  19  *          - Un-hacked slightly to use system gethostbyname()
  20  *
  21  *    06-Oct-2007 : Various fixes to allow the build on MinGW
  22  *
  23  *    28-Oct-2007: drop some dead code. now tested working without.
  24  *
  25  *    04-Nov-2010: drop SPRINTF casting macro
  26  *
  27  *  Original License and code follows.
  28  */
  29
  30 #include "squid.h"
  31
  32 #if !HAVE_DECL_INET_NTOP
  33
  34 /*
  35  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
  36  * Copyright (c) 1996-1999 by Internet Software Consortium.
  37  *
  38  * Permission to use, copy, modify, and distribute this software for any
  39  * purpose with or without fee is hereby granted, provided that the above
  40  * copyright notice and this permission notice appear in all copies.
  41  *
  42  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  43  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  44  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  45  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  46  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  47  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  48  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  49  */
  50
  51 #if defined(LIBC_SCCS) && !defined(lint)
  52 static const char rcsid[] = "inet_ntop.c,v 1.1.2.1.8.2 2005/11/03 23:08:40 marka Exp";
  53 #endif /* LIBC_SCCS and not lint */
  54
  55 #if HAVE_SYS_PARAM_H
  56 #include <sys/param.h>
  57 #endif
  58 #if HAVE_SYS_TYPES_H
  59 #include <sys/types.h>
  60 #endif
  61 #if HAVE_SYS_SOCKET_H
  62 #include <sys/socket.h>
  63 #endif
  64
  65 #if HAVE_NETINET_IN_H
  66 #include <netinet/in.h>
  67 #endif
  68 #if HAVE_ARPA_INET_H
  69 #include <arpa/inet.h>
  70 #endif
  71 #if HAVE_ARPA_NAMESER_H
  72 #include <arpa/nameser.h>
  73 #endif
  74
  75 #if HAVE_ERRNO_H
  76 #include <errno.h>
  77 #endif
  78 #if HAVE_STRING_H
  79 #include <string.h>
  80 #endif
  81
  82 #if ! defined(NS_INADDRSZ)
  83 #define NS_INADDRSZ      4
  84 #endif
  85 #if ! defined(NS_IN6ADDRSZ)
  86 #define NS_IN6ADDRSZ    16
  87 #endif
  88 #if ! defined(NS_INT16SZ)
  89 #define NS_INT16SZ      2
  90 #endif
  91
  92 /*
  93  * WARNING: Don't even consider trying to compile this on a system where
  94  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
  95  */
  96
  97 static const char *inet_ntop4 (const u_char *src, char *dst, size_t size);
  98 static const char *inet_ntop6 (const u_char *src, char *dst, size_t size);
  99
 100 /* char *
 101  * inet_ntop(af, src, dst, size)
 102  *  convert a network format address to presentation format.
 103  * return:
 104  *  pointer to presentation format address (`dst'), or NULL (see errno).
 105  * author:
 106  *  Paul Vixie, 1996.
 107  */
 108 const char *
 109 xinet_ntop(af, src, dst, size)
 110 int af;
 111 const void *src;
 112 char *dst;
 113 size_t size;
 114 {
 115     switch (af) {
 116     case AF_INET:
 117         return (inet_ntop4(src, dst, size));
 118     case AF_INET6:
 119         return (inet_ntop6(src, dst, size));
 120     default:
 121         errno = EAFNOSUPPORT;
 122         return (NULL);
 123     }
 124     /* NOTREACHED */
 125 }
 126
 127 /* const char *
 128  * inet_ntop4(src, dst, size)
 129  *  format an IPv4 address
 130  * return:
 131  *  `dst' (as a const)
 132  * notes:
 133  *  (1) uses no statics
 134  *  (2) takes a u_char* not an in_addr as input
 135  * author:
 136  *  Paul Vixie, 1996.
 137  */
 138 static const char *
 139 inet_ntop4(src, dst, size)
 140 const u_char *src;
 141 char *dst;
 142 size_t size;
 143 {
 144     static const char fmt[] = "%u.%u.%u.%u";
 145     char tmp[sizeof "255.255.255.255"];
 146
 147     if (snprintf(tmp, min(sizeof("255.255.255.255"),size), fmt, src[0], src[1], src[2], src[3]) >= size) {
 148         errno = ENOSPC;
 149         return (NULL);
 150     }
 151     strcpy(dst, tmp);
 152     return (dst);
 153 }
 154
 155 /* const char *
 156  * inet_ntop6(src, dst, size)
 157  *  convert IPv6 binary address into presentation (printable) format
 158  * author:
 159  *  Paul Vixie, 1996.
 160  */
 161 static const char *
 162 inet_ntop6(src, dst, size)
 163 const u_char *src;
 164 char *dst;
 165 size_t size;
 166 {
 167     /*
 168      * Note that int32_t and int16_t need only be "at least" large enough
 169      * to contain a value of the specified size.  On some systems, like
 170      * Crays, there is no such thing as an integer variable with 16 bits.
 171      * Keep this in mind if you think this function should have been coded
 172      * to use pointer overlays.  All the world's not a VAX.
 173      */
 174     char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
 175     struct { int base, len; } best, cur;
 176     u_int words[NS_IN6ADDRSZ / NS_INT16SZ];
 177     int i;
 178
 179     /*
 180      * Preprocess:
 181      *  Copy the input (bytewise) array into a wordwise array.
 182      *  Find the longest run of 0x00's in src[] for :: shorthanding.
 183      */
 184     memset(words, '\0', sizeof words);
 185     for (i = 0; i < NS_IN6ADDRSZ; i++)
 186         words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
 187     best.base = -1;
 188     best.len = 0;
 189     cur.base = -1;
 190     cur.len = 0;
 191     for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
 192         if (words[i] == 0) {
 193             if (cur.base == -1)
 194                 cur.base = i, cur.len = 1;
 195             else
 196                 cur.len++;
 197         } else {
 198             if (cur.base != -1) {
 199                 if (best.base == -1 || cur.len > best.len)
 200                     best = cur;
 201                 cur.base = -1;
 202             }
 203         }
 204     }
 205     if (cur.base != -1) {
 206         if (best.base == -1 || cur.len > best.len)
 207             best = cur;
 208     }
 209     if (best.base != -1 && best.len < 2)
 210         best.base = -1;
 211
 212     /*
 213      * Format the result.
 214      */
 215     tp = tmp;
 216     for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
 217         /* Are we inside the best run of 0x00's? */
 218         if (best.base != -1 && i >= best.base &&
 219                 i < (best.base + best.len)) {
 220             if (i == best.base)
 221                 *tp++ = ':';
 222             continue;
 223         }
 224         /* Are we following an initial run of 0x00s or any real hex? */
 225         if (i != 0)
 226             *tp++ = ':';
 227         /* Is this address an encapsulated IPv4? */
 228         if (i == 6 && best.base == 0 && (best.len == 6 ||
 229                                          (best.len == 7 && words[7] != 0x0001) ||
 230                                          (best.len == 5 && words[5] == 0xffff))) {
 231             if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp)))
 232                 return (NULL);
 233             tp += strlen(tp);
 234             break;
 235         }
 236         tp += snprintf(tp, (tmp + sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255") - tp), "%x", words[i]);
 237     }
 238     /* Was it a trailing run of 0x00's? */
 239     if (best.base != -1 && (best.base + best.len) ==
 240             (NS_IN6ADDRSZ / NS_INT16SZ))
 241         *tp++ = ':';
 242     *tp++ = '\0';
 243
 244     /*
 245      * Check for overflow, copy, and we're done.
 246      */
 247     if ((size_t)(tp - tmp) > size) {
 248         errno = ENOSPC;
 249         return (NULL);
 250     }
 251     strcpy(dst, tmp);
 252     return (dst);
 253 }
 254
 255 #endif /* HAVE_DECL_INET_NTOP */
 256