gl/inet_pton.c

   1 /* inet_pton.c -- convert IPv4 and IPv6 addresses from text to binary form
   2
   3    Copyright (C) 2006 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software Foundation,
  17    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  18
  19 /*
  20  * Copyright (c) 1996,1999 by Internet Software Consortium.
  21  *
  22  * Permission to use, copy, modify, and distribute this software for any
  23  * purpose with or without fee is hereby granted, provided that the above
  24  * copyright notice and this permission notice appear in all copies.
  25  *
  26  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
  27  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  28  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  29  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  30  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  31  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  32  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  33  * SOFTWARE.
  34  */
  35
  36 #include <config.h>
  37
  38 /* Specification.  */
  39 #include "inet_pton.h"
  40
  41 #include <ctype.h>
  42 #include <string.h>
  43 #include <errno.h>
  44
  45 #ifndef EAFNOSUPPORT
  46 # define EAFNOSUPPORT EINVAL
  47 #endif
  48
  49 #define NS_INADDRSZ 4
  50 #define NS_IN6ADDRSZ 16
  51 #define NS_INT16SZ 2
  52
  53 /*
  54  * WARNING: Don't even consider trying to compile this on a system where
  55  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
  56  */
  57
  58 static int inet_pton4 (const char *src, unsigned char *dst);
  59 #if HAVE_IPV6
  60 static int inet_pton6 (const char *src, unsigned char *dst);
  61 #endif
  62
  63 /* int
  64  * inet_pton(af, src, dst)
  65  *      convert from presentation format (which usually means ASCII printable)
  66  *      to network format (which is usually some kind of binary format).
  67  * return:
  68  *      1 if the address was valid for the specified address family
  69  *      0 if the address wasn't valid (`dst' is untouched in this case)
  70  *      -1 if some other error occurred (`dst' is untouched in this case, too)
  71  * author:
  72  *      Paul Vixie, 1996.
  73  */
  74 int
  75 inet_pton (int af, const char *restrict src, void *restrict dst)
  76 {
  77   switch (af)
  78     {
  79     case AF_INET:
  80       return (inet_pton4 (src, dst));
  81
  82 #if HAVE_IPV6
  83     case AF_INET6:
  84       return (inet_pton6 (src, dst));
  85 #endif
  86
  87     default:
  88       errno = EAFNOSUPPORT;
  89       return (-1);
  90     }
  91   /* NOTREACHED */
  92 }
  93
  94 /* int
  95  * inet_pton4(src, dst)
  96  *      like inet_aton() but without all the hexadecimal, octal (with the
  97  *      exception of 0) and shorthand.
  98  * return:
  99  *      1 if `src' is a valid dotted quad, else 0.
 100  * notice:
 101  *      does not touch `dst' unless it's returning 1.
 102  * author:
 103  *      Paul Vixie, 1996.
 104  */
 105 static int
 106 inet_pton4 (const char *restrict src, unsigned char *restrict dst)
 107 {
 108   int saw_digit, octets, ch;
 109   unsigned char tmp[NS_INADDRSZ], *tp;
 110
 111   saw_digit = 0;
 112   octets = 0;
 113   *(tp = tmp) = 0;
 114   while ((ch = *src++) != '\0')
 115     {
 116
 117       if (ch >= '0' && ch <= '9')
 118         {
 119           unsigned new = *tp * 10 + (ch - '0');
 120
 121           if (saw_digit && *tp == 0)
 122             return (0);
 123           if (new > 255)
 124             return (0);
 125           *tp = new;
 126           if (!saw_digit)
 127             {
 128               if (++octets > 4)
 129                 return (0);
 130               saw_digit = 1;
 131             }
 132         }
 133       else if (ch == '.' && saw_digit)
 134         {
 135           if (octets == 4)
 136             return (0);
 137           *++tp = 0;
 138           saw_digit = 0;
 139         }
 140       else
 141         return (0);
 142     }
 143   if (octets < 4)
 144     return (0);
 145   memcpy (dst, tmp, NS_INADDRSZ);
 146   return (1);
 147 }
 148
 149 #if HAVE_IPV6
 150
 151 /* int
 152  * inet_pton6(src, dst)
 153  *      convert presentation level address to network order binary form.
 154  * return:
 155  *      1 if `src' is a valid [RFC1884 2.2] address, else 0.
 156  * notice:
 157  *      (1) does not touch `dst' unless it's returning 1.
 158  *      (2) :: in a full address is silently ignored.
 159  * credit:
 160  *      inspired by Mark Andrews.
 161  * author:
 162  *      Paul Vixie, 1996.
 163  */
 164 static int
 165 inet_pton6 (const char *restrict src, unsigned char *restrict dst)
 166 {
 167   static const char xdigits[] = "0123456789abcdef";
 168   unsigned char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
 169   const char *curtok;
 170   int ch, saw_xdigit;
 171   unsigned val;
 172
 173   tp = memset (tmp, '\0', NS_IN6ADDRSZ);
 174   endp = tp + NS_IN6ADDRSZ;
 175   colonp = NULL;
 176   /* Leading :: requires some special handling. */
 177   if (*src == ':')
 178     if (*++src != ':')
 179       return (0);
 180   curtok = src;
 181   saw_xdigit = 0;
 182   val = 0;
 183   while ((ch = tolower (*src++)) != '\0')
 184     {
 185       const char *pch;
 186
 187       pch = strchr (xdigits, ch);
 188       if (pch != NULL)
 189         {
 190           val <<= 4;
 191           val |= (pch - xdigits);
 192           if (val > 0xffff)
 193             return (0);
 194           saw_xdigit = 1;
 195           continue;
 196         }
 197       if (ch == ':')
 198         {
 199           curtok = src;
 200           if (!saw_xdigit)
 201             {
 202               if (colonp)
 203                 return (0);
 204               colonp = tp;
 205               continue;
 206             }
 207           else if (*src == '\0')
 208             {
 209               return (0);
 210             }
 211           if (tp + NS_INT16SZ > endp)
 212             return (0);
 213           *tp++ = (u_char) (val >> 8) & 0xff;
 214           *tp++ = (u_char) val & 0xff;
 215           saw_xdigit = 0;
 216           val = 0;
 217           continue;
 218         }
 219       if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
 220           inet_pton4 (curtok, tp) > 0)
 221         {
 222           tp += NS_INADDRSZ;
 223           saw_xdigit = 0;
 224           break;                /* '\0' was seen by inet_pton4(). */
 225         }
 226       return (0);
 227     }
 228   if (saw_xdigit)
 229     {
 230       if (tp + NS_INT16SZ > endp)
 231         return (0);
 232       *tp++ = (u_char) (val >> 8) & 0xff;
 233       *tp++ = (u_char) val & 0xff;
 234     }
 235   if (colonp != NULL)
 236     {
 237       /*
 238        * Since some memmove()'s erroneously fail to handle
 239        * overlapping regions, we'll do the shift by hand.
 240        */
 241       const int n = tp - colonp;
 242       int i;
 243
 244       if (tp == endp)
 245         return (0);
 246       for (i = 1; i <= n; i++)
 247         {
 248           endp[-i] = colonp[n - i];
 249           colonp[n - i] = 0;
 250         }
 251       tp = endp;
 252     }
 253   if (tp != endp)
 254     return (0);
 255   memcpy (dst, tmp, NS_IN6ADDRSZ);
 256   return (1);
 257 }
 258 #endif