resolv/inet_pton.c

   1 /* Copyright (c) 1996 by Internet Software Consortium.
   2  *
   3  * Permission to use, copy, modify, and distribute this software for any
   4  * purpose with or without fee is hereby granted, provided that the above
   5  * copyright notice and this permission notice appear in all copies.
   6  *
   7  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
   8  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
   9  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  10  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  11  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  12  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  13  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  14  * SOFTWARE.
  15  */
  16
  17 #if defined(LIBC_SCCS) && !defined(lint)
  18 static char rcsid[] = "$Id$";
  19 #endif /* LIBC_SCCS and not lint */
  20
  21 #include <sys/param.h>
  22 #include <sys/types.h>
  23 #include <sys/socket.h>
  24 #include <netinet/in.h>
  25 #include <arpa/inet.h>
  26 #include <arpa/nameser.h>
  27 #include <string.h>
  28 #include <errno.h>
  29 #include <conf/portability.h>
  30
  31 /*
  32  * WARNING: Don't even consider trying to compile this on a system where
  33  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
  34  */
  35
  36 static int inet_pton4 __P((const char *src, u_char *dst)) internal_function;
  37 static int inet_pton6 __P((const char *src, u_char *dst)) internal_function;
  38
  39 /* int
  40  * inet_pton(af, src, dst)
  41  *      convert from presentation format (which usually means ASCII printable)
  42  *      to network format (which is usually some kind of binary format).
  43  * return:
  44  *      1 if the address was valid for the specified address family
  45  *      0 if the address wasn't valid (`dst' is untouched in this case)
  46  *      -1 if some other error occurred (`dst' is untouched in this case, too)
  47  * author:
  48  *      Paul Vixie, 1996.
  49  */
  50 int
  51 inet_pton(af, src, dst)
  52         int af;
  53         const char *src;
  54         void *dst;
  55 {
  56         switch (af) {
  57         case AF_INET:
  58                 return (inet_pton4(src, dst));
  59         case AF_INET6:
  60                 return (inet_pton6(src, dst));
  61         default:
  62                 __set_errno (EAFNOSUPPORT);
  63                 return (-1);
  64         }
  65         /* NOTREACHED */
  66 }
  67
  68 /* int
  69  * inet_pton4(src, dst)
  70  *      like inet_aton() but without all the hexadecimal and shorthand.
  71  * return:
  72  *      1 if `src' is a valid dotted quad, else 0.
  73  * notice:
  74  *      does not touch `dst' unless it's returning 1.
  75  * author:
  76  *      Paul Vixie, 1996.
  77  */
  78 static int
  79 internal_function
  80 inet_pton4(src, dst)
  81         const char *src;
  82         u_char *dst;
  83 {
  84         int saw_digit, octets, ch;
  85         u_char tmp[INADDRSZ], *tp;
  86
  87         saw_digit = 0;
  88         octets = 0;
  89         *(tp = tmp) = 0;
  90         while ((ch = *src++) != '\0') {
  91
  92                 if (ch >= '0' && ch <= '9') {
  93                         u_int new = *tp * 10 + (ch - '0');
  94
  95                         if (new > 255)
  96                                 return (0);
  97                         *tp = new;
  98                         if (! saw_digit) {
  99                                 if (++octets > 4)
 100                                         return (0);
 101                                 saw_digit = 1;
 102                         }
 103                 } else if (ch == '.' && saw_digit) {
 104                         if (octets == 4)
 105                                 return (0);
 106                         *++tp = 0;
 107                         saw_digit = 0;
 108                 } else
 109                         return (0);
 110         }
 111         if (octets < 4)
 112                 return (0);
 113
 114         memcpy(dst, tmp, INADDRSZ);
 115         return (1);
 116 }
 117
 118 /* int
 119  * inet_pton6(src, dst)
 120  *      convert presentation level address to network order binary form.
 121  * return:
 122  *      1 if `src' is a valid [RFC1884 2.2] address, else 0.
 123  * notice:
 124  *      (1) does not touch `dst' unless it's returning 1.
 125  *      (2) :: in a full address is silently ignored.
 126  * credit:
 127  *      inspired by Mark Andrews.
 128  * author:
 129  *      Paul Vixie, 1996.
 130  */
 131 static int
 132 internal_function
 133 inet_pton6(src, dst)
 134         const char *src;
 135         u_char *dst;
 136 {
 137         static const char xdigits[] = "0123456789abcdef";
 138         u_char tmp[IN6ADDRSZ], *tp, *endp, *colonp;
 139         const char *curtok;
 140         int ch, saw_xdigit;
 141         u_int val;
 142
 143         tp = memset(tmp, '\0', IN6ADDRSZ);
 144         endp = tp + IN6ADDRSZ;
 145         colonp = NULL;
 146         /* Leading :: requires some special handling. */
 147         if (*src == ':')
 148                 if (*++src != ':')
 149                         return (0);
 150         curtok = src;
 151         saw_xdigit = 0;
 152         val = 0;
 153         while ((ch = tolower (*src++)) != '\0') {
 154                 const char *pch;
 155
 156                 pch = strchr(xdigits, ch);
 157                 if (pch != NULL) {
 158                         val <<= 4;
 159                         val |= (pch - xdigits);
 160                         if (val > 0xffff)
 161                                 return (0);
 162                         saw_xdigit = 1;
 163                         continue;
 164                 }
 165                 if (ch == ':') {
 166                         curtok = src;
 167                         if (!saw_xdigit) {
 168                                 if (colonp)
 169                                         return (0);
 170                                 colonp = tp;
 171                                 continue;
 172                         }
 173                         if (tp + INT16SZ > endp)
 174                                 return (0);
 175                         *tp++ = (u_char) (val >> 8) & 0xff;
 176                         *tp++ = (u_char) val & 0xff;
 177                         saw_xdigit = 0;
 178                         val = 0;
 179                         continue;
 180                 }
 181                 if (ch == '.' && ((tp + INADDRSZ) <= endp) &&
 182                     inet_pton4(curtok, tp) > 0) {
 183                         tp += INADDRSZ;
 184                         saw_xdigit = 0;
 185                         break;  /* '\0' was seen by inet_pton4(). */
 186                 }
 187                 return (0);
 188         }
 189         if (saw_xdigit) {
 190                 if (tp + INT16SZ > endp)
 191                         return (0);
 192                 *tp++ = (u_char) (val >> 8) & 0xff;
 193                 *tp++ = (u_char) val & 0xff;
 194         }
 195         if (colonp != NULL) {
 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                 for (i = 1; i <= n; i++) {
 204                         endp[- i] = colonp[n - i];
 205                         colonp[n - i] = 0;
 206                 }
 207                 tp = endp;
 208         }
 209         if (tp != endp)
 210                 return (0);
 211         memcpy(dst, tmp, IN6ADDRSZ);
 212         return (1);
 213 }