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 #if defined(LIBC_SCCS) && !defined(lint)
  19 static const char rcsid[] = "$BINDId: inet_pton.c,v 1.7 1999/10/13 16:39:28 vixie Exp $";
  20 #endif /* LIBC_SCCS and not lint */
  21
  22 #include <sys/param.h>
  23 #include <sys/types.h>
  24 #include <sys/socket.h>
  25 #include <netinet/in.h>
  26 #include <arpa/inet.h>
  27 #include <arpa/nameser.h>
  28 #include <ctype.h>
  29 #include <string.h>
  30 #include <errno.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 libc_hidden_def (inet_pton)
  69
  70 /* int
  71  * inet_pton4(src, dst)
  72  *      like inet_aton() but without all the hexadecimal, octal (with the
  73  *      exception of 0) and shorthand.
  74  * return:
  75  *      1 if `src' is a valid dotted quad, else 0.
  76  * notice:
  77  *      does not touch `dst' unless it's returning 1.
  78  * author:
  79  *      Paul Vixie, 1996.
  80  */
  81 static int
  82 internal_function
  83 inet_pton4(src, dst)
  84         const char *src;
  85         u_char *dst;
  86 {
  87         int saw_digit, octets, ch;
  88         u_char tmp[NS_INADDRSZ], *tp;
  89
  90         saw_digit = 0;
  91         octets = 0;
  92         *(tp = tmp) = 0;
  93         while ((ch = *src++) != '\0') {
  94
  95                 if (ch >= '0' && ch <= '9') {
  96                         u_int new = *tp * 10 + (ch - '0');
  97
  98                         if (saw_digit && *tp == 0)
  99                                 return (0);
 100                         if (new > 255)
 101                                 return (0);
 102                         *tp = new;
 103                         if (! saw_digit) {
 104                                 if (++octets > 4)
 105                                         return (0);
 106                                 saw_digit = 1;
 107                         }
 108                 } else if (ch == '.' && saw_digit) {
 109                         if (octets == 4)
 110                                 return (0);
 111                         *++tp = 0;
 112                         saw_digit = 0;
 113                 } else
 114                         return (0);
 115         }
 116         if (octets < 4)
 117                 return (0);
 118         memcpy(dst, tmp, NS_INADDRSZ);
 119         return (1);
 120 }
 121
 122 /* int
 123  * inet_pton6(src, dst)
 124  *      convert presentation level address to network order binary form.
 125  * return:
 126  *      1 if `src' is a valid [RFC1884 2.2] address, else 0.
 127  * notice:
 128  *      (1) does not touch `dst' unless it's returning 1.
 129  *      (2) :: in a full address is silently ignored.
 130  * credit:
 131  *      inspired by Mark Andrews.
 132  * author:
 133  *      Paul Vixie, 1996.
 134  */
 135 static int
 136 internal_function
 137 inet_pton6(src, dst)
 138         const char *src;
 139         u_char *dst;
 140 {
 141         static const char xdigits[] = "0123456789abcdef";
 142         u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
 143         const char *curtok;
 144         int ch, saw_xdigit;
 145         u_int val;
 146
 147         tp = memset(tmp, '\0', NS_IN6ADDRSZ);
 148         endp = tp + NS_IN6ADDRSZ;
 149         colonp = NULL;
 150         /* Leading :: requires some special handling. */
 151         if (*src == ':')
 152                 if (*++src != ':')
 153                         return (0);
 154         curtok = src;
 155         saw_xdigit = 0;
 156         val = 0;
 157         while ((ch = tolower (*src++)) != '\0') {
 158                 const char *pch;
 159
 160                 pch = strchr(xdigits, ch);
 161                 if (pch != NULL) {
 162                         val <<= 4;
 163                         val |= (pch - xdigits);
 164                         if (val > 0xffff)
 165                                 return (0);
 166                         saw_xdigit = 1;
 167                         continue;
 168                 }
 169                 if (ch == ':') {
 170                         curtok = src;
 171                         if (!saw_xdigit) {
 172                                 if (colonp)
 173                                         return (0);
 174                                 colonp = tp;
 175                                 continue;
 176                         } else if (*src == '\0') {
 177                                 return (0);
 178                         }
 179                         if (tp + NS_INT16SZ > endp)
 180                                 return (0);
 181                         *tp++ = (u_char) (val >> 8) & 0xff;
 182                         *tp++ = (u_char) val & 0xff;
 183                         saw_xdigit = 0;
 184                         val = 0;
 185                         continue;
 186                 }
 187                 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
 188                     inet_pton4(curtok, tp) > 0) {
 189                         tp += NS_INADDRSZ;
 190                         saw_xdigit = 0;
 191                         break;  /* '\0' was seen by inet_pton4(). */
 192                 }
 193                 return (0);
 194         }
 195         if (saw_xdigit) {
 196                 if (tp + NS_INT16SZ > endp)
 197                         return (0);
 198                 *tp++ = (u_char) (val >> 8) & 0xff;
 199                 *tp++ = (u_char) val & 0xff;
 200         }
 201         if (colonp != NULL) {
 202                 /*
 203                  * Since some memmove()'s erroneously fail to handle
 204                  * overlapping regions, we'll do the shift by hand.
 205                  */
 206                 const int n = tp - colonp;
 207                 int i;
 208
 209                 if (tp == endp)
 210                         return (0);
 211                 for (i = 1; i <= n; i++) {
 212                         endp[- i] = colonp[n - i];
 213                         colonp[n - i] = 0;
 214                 }
 215                 tp = endp;
 216         }
 217         if (tp != endp)
 218                 return (0);
 219         memcpy(dst, tmp, NS_IN6ADDRSZ);
 220         return (1);
 221 }