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 <ctype.h>
  28 #include <string.h>
  29 #include <errno.h>
  30 #include <conf/portability.h>
  31
  32 /*
  33  * WARNING: Don't even consider trying to compile this on a system where
  34  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
  35  */
  36
  37 static int inet_pton4 (const char *src, u_char *dst) internal_function;
  38 static int inet_pton6 (const char *src, u_char *dst) internal_function;
  39
  40 /* int
  41  * inet_pton(af, src, dst)
  42  *      convert from presentation format (which usually means ASCII printable)
  43  *      to network format (which is usually some kind of binary format).
  44  * return:
  45  *      1 if the address was valid for the specified address family
  46  *      0 if the address wasn't valid (`dst' is untouched in this case)
  47  *      -1 if some other error occurred (`dst' is untouched in this case, too)
  48  * author:
  49  *      Paul Vixie, 1996.
  50  */
  51 int
  52 inet_pton(af, src, dst)
  53         int af;
  54         const char *src;
  55         void *dst;
  56 {
  57         switch (af) {
  58         case AF_INET:
  59                 return (inet_pton4(src, dst));
  60         case AF_INET6:
  61                 return (inet_pton6(src, dst));
  62         default:
  63                 __set_errno (EAFNOSUPPORT);
  64                 return (-1);
  65         }
  66         /* NOTREACHED */
  67 }
  68
  69 /* int
  70  * inet_pton4(src, dst)
  71  *      like inet_aton() but without all the hexadecimal and shorthand.
  72  * return:
  73  *      1 if `src' is a valid dotted quad, else 0.
  74  * notice:
  75  *      does not touch `dst' unless it's returning 1.
  76  * author:
  77  *      Paul Vixie, 1996.
  78  */
  79 static int
  80 internal_function
  81 inet_pton4(src, dst)
  82         const char *src;
  83         u_char *dst;
  84 {
  85         int saw_digit, octets, ch;
  86         u_char tmp[INADDRSZ], *tp;
  87
  88         saw_digit = 0;
  89         octets = 0;
  90         *(tp = tmp) = 0;
  91         while ((ch = *src++) != '\0') {
  92
  93                 if (ch >= '0' && ch <= '9') {
  94                         u_int new = *tp * 10 + (ch - '0');
  95
  96                         if (new > 255)
  97                                 return (0);
  98                         *tp = new;
  99                         if (! saw_digit) {
 100                                 if (++octets > 4)
 101                                         return (0);
 102                                 saw_digit = 1;
 103                         }
 104                 } else if (ch == '.' && saw_digit) {
 105                         if (octets == 4)
 106                                 return (0);
 107                         *++tp = 0;
 108                         saw_digit = 0;
 109                 } else
 110                         return (0);
 111         }
 112         if (octets < 4)
 113                 return (0);
 114
 115         memcpy(dst, tmp, INADDRSZ);
 116         return (1);
 117 }
 118
 119 /* int
 120  * inet_pton6(src, dst)
 121  *      convert presentation level address to network order binary form.
 122  * return:
 123  *      1 if `src' is a valid [RFC1884 2.2] address, else 0.
 124  * notice:
 125  *      (1) does not touch `dst' unless it's returning 1.
 126  *      (2) :: in a full address is silently ignored.
 127  * credit:
 128  *      inspired by Mark Andrews.
 129  * author:
 130  *      Paul Vixie, 1996.
 131  */
 132 static int
 133 internal_function
 134 inet_pton6(src, dst)
 135         const char *src;
 136         u_char *dst;
 137 {
 138         static const char xdigits[] = "0123456789abcdef";
 139         u_char tmp[IN6ADDRSZ], *tp, *endp, *colonp;
 140         const char *curtok;
 141         int ch, saw_xdigit;
 142         u_int val;
 143
 144         tp = memset(tmp, '\0', IN6ADDRSZ);
 145         endp = tp + IN6ADDRSZ;
 146         colonp = NULL;
 147         /* Leading :: requires some special handling. */
 148         if (*src == ':')
 149                 if (*++src != ':')
 150                         return (0);
 151         curtok = src;
 152         saw_xdigit = 0;
 153         val = 0;
 154         while ((ch = tolower (*src++)) != '\0') {
 155                 const char *pch;
 156
 157                 pch = strchr(xdigits, ch);
 158                 if (pch != NULL) {
 159                         val <<= 4;
 160                         val |= (pch - xdigits);
 161                         if (val > 0xffff)
 162                                 return (0);
 163                         saw_xdigit = 1;
 164                         continue;
 165                 }
 166                 if (ch == ':') {
 167                         curtok = src;
 168                         if (!saw_xdigit) {
 169                                 if (colonp)
 170                                         return (0);
 171                                 colonp = tp;
 172                                 continue;
 173                         }
 174                         if (tp + INT16SZ > endp)
 175                                 return (0);
 176                         *tp++ = (u_char) (val >> 8) & 0xff;
 177                         *tp++ = (u_char) val & 0xff;
 178                         saw_xdigit = 0;
 179                         val = 0;
 180                         continue;
 181                 }
 182                 if (ch == '.' && ((tp + INADDRSZ) <= endp) &&
 183                     inet_pton4(curtok, tp) > 0) {
 184                         tp += INADDRSZ;
 185                         saw_xdigit = 0;
 186                         break;  /* '\0' was seen by inet_pton4(). */
 187                 }
 188                 return (0);
 189         }
 190         if (saw_xdigit) {
 191                 if (tp + INT16SZ > endp)
 192                         return (0);
 193                 *tp++ = (u_char) (val >> 8) & 0xff;
 194                 *tp++ = (u_char) val & 0xff;
 195         }
 196         if (colonp != NULL) {
 197                 /*
 198                  * Since some memmove()'s erroneously fail to handle
 199                  * overlapping regions, we'll do the shift by hand.
 200                  */
 201                 const int n = tp - colonp;
 202                 int i;
 203
 204                 for (i = 1; i <= n; i++) {
 205                         endp[- i] = colonp[n - i];
 206                         colonp[n - i] = 0;
 207                 }
 208                 tp = endp;
 209         }
 210         if (tp != endp)
 211                 return (0);
 212         memcpy(dst, tmp, IN6ADDRSZ);
 213         return (1);
 214 }