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
  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[NS_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         memcpy(dst, tmp, NS_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[NS_IN6ADDRSZ], *tp, *endp, *colonp;
 139         const char *curtok;
 140         int ch, saw_xdigit;
 141         u_int val;
 142
 143         tp = memset(tmp, '\0', NS_IN6ADDRSZ);
 144         endp = tp + NS_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                         } else if (*src == '\0') {
 173                                 return (0);
 174                         }
 175                         if (tp + NS_INT16SZ > endp)
 176                                 return (0);
 177                         *tp++ = (u_char) (val >> 8) & 0xff;
 178                         *tp++ = (u_char) val & 0xff;
 179                         saw_xdigit = 0;
 180                         val = 0;
 181                         continue;
 182                 }
 183                 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
 184                     inet_pton4(curtok, tp) > 0) {
 185                         tp += NS_INADDRSZ;
 186                         saw_xdigit = 0;
 187                         break;  /* '\0' was seen by inet_pton4(). */
 188                 }
 189                 return (0);
 190         }
 191         if (saw_xdigit) {
 192                 if (tp + NS_INT16SZ > endp)
 193                         return (0);
 194                 *tp++ = (u_char) (val >> 8) & 0xff;
 195                 *tp++ = (u_char) val & 0xff;
 196         }
 197         if (colonp != NULL) {
 198                 /*
 199                  * Since some memmove()'s erroneously fail to handle
 200                  * overlapping regions, we'll do the shift by hand.
 201                  */
 202                 const int n = tp - colonp;
 203                 int i;
 204
 205                 if (tp == endp)
 206                         return (0);
 207                 for (i = 1; i <= n; i++) {
 208                         endp[- i] = colonp[n - i];
 209                         colonp[n - i] = 0;
 210                 }
 211                 tp = endp;
 212         }
 213         if (tp != endp)
 214                 return (0);
 215         memcpy(dst, tmp, NS_IN6ADDRSZ);
 216         return (1);
 217 }