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));
  37 static int      inet_pton6 __P((const char *src, u_char *dst));
  38
  39 /* int
  40  * inet_pton(af, src, dst, size)
  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, size)
  52         int af;
  53         const char *src;
  54         void *dst;
  55         size_t size;
  56 {
  57         switch (af) {
  58         case AF_INET:
  59                 if (size < INADDRSZ) {
  60                         errno = ENOSPC;
  61                         return (-1);
  62                 }
  63                 return (inet_pton4(src, dst));
  64         case AF_INET6:
  65                 if (size < IN6ADDRSZ) {
  66                         errno = ENOSPC;
  67                         return (-1);
  68                 }
  69                 return (inet_pton6(src, dst));
  70         default:
  71                 errno = EINVAL;
  72                 return (-1);
  73         }
  74         /* NOTREACHED */
  75 }
  76
  77 /* int
  78  * inet_pton4(src, dst)
  79  *      like inet_pton() but without all the hexadecimal and shorthand.
  80  * return:
  81  *      1 if `src' is a valid dotted quad, else 0.
  82  * notice:
  83  *      does not touch `dst' unless it's returning 1.
  84  * author:
  85  *      Paul Vixie, 1996.
  86  */
  87 static int
  88 inet_pton4(src, dst)
  89         const char *src;
  90         u_char *dst;
  91 {
  92         static const char digits[] = "0123456789";
  93         int saw_digit, octets, ch;
  94         u_char tmp[INADDRSZ], *tp;
  95
  96         saw_digit = 0;
  97         octets = 0;
  98         *(tp = tmp) = 0;
  99         while ((ch = *src++) != '\0') {
 100                 const char *pch;
 101
 102                 if ((pch = strchr(digits, ch)) != NULL) {
 103                         u_int new = *tp * 10 + (pch - digits);
 104
 105                         if (new > 255)
 106                                 return (0);
 107                         *tp = new;
 108                         if (! saw_digit) {
 109                                 if (++octets > 4)
 110                                         return (0);
 111                                 saw_digit = 1;
 112                         }
 113                 } else if (ch == '.' && saw_digit) {
 114                         if (octets == 4)
 115                                 return (0);
 116                         *++tp = 0;
 117                         saw_digit = 0;
 118                 } else
 119                         return (0);
 120         }
 121         if (octets < 4)
 122                 return (0);
 123         bcopy(tmp, dst, INADDRSZ);
 124         return (1);
 125 }
 126
 127 /* int
 128  * inet_pton6(src, dst)
 129  *      convert presentation level address to network order binary form.
 130  * return:
 131  *      1 if `src' is a valid [RFC1884 2.2] address, else 0.
 132  * notice:
 133  *      (1) does not touch `dst' unless it's returning 1.
 134  *      (2) :: in a full address is silently ignored.
 135  * credit:
 136  *      inspired by Mark Andrews.
 137  * author:
 138  *      Paul Vixie, 1996.
 139  */
 140 static int
 141 inet_pton6(src, dst)
 142         const char *src;
 143         u_char *dst;
 144 {
 145         static const char xdigits_l[] = "0123456789abcdef",
 146                           xdigits_u[] = "0123456789ABCDEF";
 147         u_char tmp[IN6ADDRSZ], *tp, *endp, *colonp;
 148         const char *xdigits, *curtok;
 149         int ch, saw_xdigit;
 150         u_int val;
 151
 152         bzero((tp = tmp), IN6ADDRSZ);
 153         endp = tp + IN6ADDRSZ;
 154         colonp = NULL;
 155         /* Leading :: requires some special handling. */
 156         if (*src == ':')
 157                 if (*++src != ':')
 158                         return (0);
 159         curtok = src;
 160         saw_xdigit = 0;
 161         val = 0;
 162         while ((ch = *src++) != '\0') {
 163                 const char *pch;
 164
 165                 if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
 166                         pch = strchr((xdigits = xdigits_u), ch);
 167                 if (pch != NULL) {
 168                         val <<= 4;
 169                         val |= (pch - xdigits);
 170                         if (val > 0xffff)
 171                                 return (0);
 172                         saw_xdigit = 1;
 173                         continue;
 174                 }
 175                 if (ch == ':') {
 176                         curtok = src;
 177                         if (!saw_xdigit) {
 178                                 if (colonp)
 179                                         return (0);
 180                                 colonp = tp;
 181                                 continue;
 182                         }
 183                         if (tp + INT16SZ > endp)
 184                                 return (0);
 185                         *tp++ = (u_char) (val >> 8) & 0xff;
 186                         *tp++ = (u_char) val & 0xff;
 187                         saw_xdigit = 0;
 188                         val = 0;
 189                         continue;
 190                 }
 191                 if (ch == '.' && ((tp + INADDRSZ) <= endp) &&
 192                     inet_pton4(curtok, tp) > 0) {
 193                         tp += INADDRSZ;
 194                         saw_xdigit = 0;
 195                         break;  /* '\0' was seen by inet_pton4(). */
 196                 }
 197                 return (0);
 198         }
 199         if (saw_xdigit) {
 200                 if (tp + INT16SZ > endp)
 201                         return (0);
 202                 *tp++ = (u_char) (val >> 8) & 0xff;
 203                 *tp++ = (u_char) val & 0xff;
 204         }
 205         if (colonp != NULL) {
 206                 /*
 207                  * Since some memmove()'s erroneously fail to handle
 208                  * overlapping regions, we'll do the shift by hand.
 209                  */
 210                 const howmany = tp - colonp;
 211                 int i;
 212
 213                 for (i = 1; i <= howmany; i++) {
 214                         endp[- i] = colonp[howmany - i];
 215                         colonp[howmany - i] = 0;
 216                 }
 217                 tp = endp;
 218         }
 219         if (tp != endp)
 220                 return (0);
 221         bcopy(tmp, dst, IN6ADDRSZ);
 222         return (1);
 223 }