resolv/inet_pton.c

   1 /*
   2  * Copyright (c) 1996,1999 by Internet Software Consortium.
   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 <sys/param.h>
  19 #include <sys/types.h>
  20 #include <sys/socket.h>
  21 #include <netinet/in.h>
  22 #include <arpa/inet.h>
  23 #include <arpa/nameser.h>
  24 #include <ctype.h>
  25 #include <string.h>
  26 #include <errno.h>
  27
  28 static int inet_pton4 (const char *src, unsigned char *dst);
  29 static int inet_pton6 (const char *src, unsigned char *dst);
  30
  31 /* Convert from presentation format (which usually means ASCII printable)
  32  * to network format (which is usually some kind of binary format).
  33  *
  34  * return:
  35  *      1 if the address was valid for the specified address family
  36  *      0 if the address wasn't valid (`dst' is untouched in this case)
  37  *      -1 if some other error occurred (`dst' is untouched in this case, too)
  38  * author:
  39  *      Paul Vixie, 1996.
  40  */
  41 int
  42 __inet_pton (int af, const char *src, void *dst)
  43 {
  44   switch (af)
  45     {
  46     case AF_INET:
  47       return inet_pton4 (src, dst);
  48     case AF_INET6:
  49       return inet_pton6 (src, dst);
  50     default:
  51       __set_errno (EAFNOSUPPORT);
  52       return -1;
  53     }
  54 }
  55 libc_hidden_def (__inet_pton)
  56 weak_alias (__inet_pton, inet_pton)
  57 libc_hidden_weak (inet_pton)
  58
  59 /* Like inet_atonbut without all the hexadecimal, octal and shorthand.
  60  *
  61  * return:
  62  *      1 if `src' is a valid dotted quad, else 0.
  63  * notice:
  64  *      does not touch `dst' unless it's returning 1.
  65  * author:
  66  *      Paul Vixie, 1996.
  67  */
  68 static int
  69 inet_pton4 (const char *src, unsigned char *dst)
  70 {
  71   int saw_digit, octets, ch;
  72   unsigned char tmp[NS_INADDRSZ], *tp;
  73
  74   saw_digit = 0;
  75   octets = 0;
  76   *(tp = tmp) = 0;
  77   while ((ch = *src++) != '\0')
  78     {
  79       if (ch >= '0' && ch <= '9')
  80         {
  81           unsigned int new = *tp * 10 + (ch - '0');
  82
  83           if (saw_digit && *tp == 0)
  84             return 0;
  85           if (new > 255)
  86             return 0;
  87           *tp = new;
  88           if (! saw_digit)
  89             {
  90               if (++octets > 4)
  91                 return 0;
  92               saw_digit = 1;
  93             }
  94         }
  95       else if (ch == '.' && saw_digit)
  96         {
  97           if (octets == 4)
  98             return 0;
  99           *++tp = 0;
 100           saw_digit = 0;
 101         }
 102       else
 103         return 0;
 104     }
 105   if (octets < 4)
 106     return 0;
 107   memcpy (dst, tmp, NS_INADDRSZ);
 108   return 1;
 109 }
 110
 111 /* Cconvert presentation level address to network order binary form.
 112  *
 113  * return:
 114  *      1 if `src' is a valid [RFC1884 2.2] address, else 0.
 115  * notice:
 116  *      (1) does not touch `dst' unless it's returning 1.
 117  *      (2) :: in a full address is silently ignored.
 118  * credit:
 119  *      inspired by Mark Andrews.
 120  * author:
 121  *      Paul Vixie, 1996.
 122  */
 123 static int
 124 inet_pton6 (const char *src, unsigned char *dst)
 125 {
 126   static const char xdigits[] = "0123456789abcdef";
 127   unsigned char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
 128   const char *curtok;
 129   int ch, saw_xdigit;
 130   unsigned int val;
 131
 132   tp = memset (tmp, '\0', NS_IN6ADDRSZ);
 133   endp = tp + NS_IN6ADDRSZ;
 134   colonp = NULL;
 135   /* Leading :: requires some special handling.  */
 136   if (*src == ':')
 137     if (*++src != ':')
 138       return 0;
 139   curtok = src;
 140   saw_xdigit = 0;
 141   val = 0;
 142   while ((ch = tolower (*src++)) != '\0')
 143     {
 144       const char *pch;
 145
 146       pch = strchr (xdigits, ch);
 147       if (pch != NULL)
 148         {
 149           val <<= 4;
 150           val |= (pch - xdigits);
 151           if (val > 0xffff)
 152             return 0;
 153           saw_xdigit = 1;
 154           continue;
 155         }
 156       if (ch == ':')
 157         {
 158           curtok = src;
 159           if (!saw_xdigit)
 160             {
 161               if (colonp)
 162                 return 0;
 163               colonp = tp;
 164               continue;
 165             }
 166           else if (*src == '\0')
 167             {
 168               return 0;
 169             }
 170           if (tp + NS_INT16SZ > endp)
 171             return 0;
 172           *tp++ = (unsigned char) (val >> 8) & 0xff;
 173           *tp++ = (unsigned char) val & 0xff;
 174           saw_xdigit = 0;
 175           val = 0;
 176           continue;
 177         }
 178       if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
 179           inet_pton4 (curtok, tp) > 0)
 180         {
 181           tp += NS_INADDRSZ;
 182           saw_xdigit = 0;
 183           break;  /* '\0' was seen by inet_pton4.  */
 184         }
 185       return 0;
 186     }
 187   if (saw_xdigit)
 188     {
 189       if (tp + NS_INT16SZ > endp)
 190         return 0;
 191       *tp++ = (unsigned char) (val >> 8) & 0xff;
 192       *tp++ = (unsigned char) val & 0xff;
 193     }
 194   if (colonp != NULL)
 195     {
 196       /*
 197        * Since some memmove's erroneously fail to handle
 198        * overlapping regions, we'll do the shift by hand.
 199        */
 200       const int n = tp - colonp;
 201       int i;
 202
 203       if (tp == endp)
 204         return 0;
 205       for (i = 1; i <= n; i++)
 206         {
 207           endp[- i] = colonp[n - i];
 208           colonp[n - i] = 0;
 209         }
 210       tp = endp;
 211     }
 212   if (tp != endp)
 213     return 0;
 214   memcpy (dst, tmp, NS_IN6ADDRSZ);
 215   return 1;
 216 }