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 weak_alias (__inet_pton, inet_pton)
  70 libc_hidden_weak (inet_pton)
  71
  72 /* int
  73  * inet_pton4(src, dst)
  74  *      like inet_aton() but without all the hexadecimal, octal (with the
  75  *      exception of 0) and shorthand.
  76  * return:
  77  *      1 if `src' is a valid dotted quad, else 0.
  78  * notice:
  79  *      does not touch `dst' unless it's returning 1.
  80  * author:
  81  *      Paul Vixie, 1996.
  82  */
  83 static int
  84 internal_function
  85 inet_pton4(src, dst)
  86         const char *src;
  87         u_char *dst;
  88 {
  89         int saw_digit, octets, ch;
  90         u_char tmp[NS_INADDRSZ], *tp;
  91
  92         saw_digit = 0;
  93         octets = 0;
  94         *(tp = tmp) = 0;
  95         while ((ch = *src++) != '\0') {
  96
  97                 if (ch >= '0' && ch <= '9') {
  98                         u_int new = *tp * 10 + (ch - '0');
  99
 100                         if (saw_digit && *tp == 0)
 101                                 return (0);
 102                         if (new > 255)
 103                                 return (0);
 104                         *tp = new;
 105                         if (! saw_digit) {
 106                                 if (++octets > 4)
 107                                         return (0);
 108                                 saw_digit = 1;
 109                         }
 110                 } else if (ch == '.' && saw_digit) {
 111                         if (octets == 4)
 112                                 return (0);
 113                         *++tp = 0;
 114                         saw_digit = 0;
 115                 } else
 116                         return (0);
 117         }
 118         if (octets < 4)
 119                 return (0);
 120         memcpy(dst, tmp, NS_INADDRSZ);
 121         return (1);
 122 }
 123
 124 /* int
 125  * inet_pton6(src, dst)
 126  *      convert presentation level address to network order binary form.
 127  * return:
 128  *      1 if `src' is a valid [RFC1884 2.2] address, else 0.
 129  * notice:
 130  *      (1) does not touch `dst' unless it's returning 1.
 131  *      (2) :: in a full address is silently ignored.
 132  * credit:
 133  *      inspired by Mark Andrews.
 134  * author:
 135  *      Paul Vixie, 1996.
 136  */
 137 static int
 138 internal_function
 139 inet_pton6(src, dst)
 140         const char *src;
 141         u_char *dst;
 142 {
 143         static const char xdigits[] = "0123456789abcdef";
 144         u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
 145         const char *curtok;
 146         int ch, saw_xdigit;
 147         u_int val;
 148
 149         tp = memset(tmp, '\0', NS_IN6ADDRSZ);
 150         endp = tp + NS_IN6ADDRSZ;
 151         colonp = NULL;
 152         /* Leading :: requires some special handling. */
 153         if (*src == ':')
 154                 if (*++src != ':')
 155                         return (0);
 156         curtok = src;
 157         saw_xdigit = 0;
 158         val = 0;
 159         while ((ch = tolower (*src++)) != '\0') {
 160                 const char *pch;
 161
 162                 pch = strchr(xdigits, ch);
 163                 if (pch != NULL) {
 164                         val <<= 4;
 165                         val |= (pch - xdigits);
 166                         if (val > 0xffff)
 167                                 return (0);
 168                         saw_xdigit = 1;
 169                         continue;
 170                 }
 171                 if (ch == ':') {
 172                         curtok = src;
 173                         if (!saw_xdigit) {
 174                                 if (colonp)
 175                                         return (0);
 176                                 colonp = tp;
 177                                 continue;
 178                         } else if (*src == '\0') {
 179                                 return (0);
 180                         }
 181                         if (tp + NS_INT16SZ > endp)
 182                                 return (0);
 183                         *tp++ = (u_char) (val >> 8) & 0xff;
 184                         *tp++ = (u_char) val & 0xff;
 185                         saw_xdigit = 0;
 186                         val = 0;
 187                         continue;
 188                 }
 189                 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
 190                     inet_pton4(curtok, tp) > 0) {
 191                         tp += NS_INADDRSZ;
 192                         saw_xdigit = 0;
 193                         break;  /* '\0' was seen by inet_pton4(). */
 194                 }
 195                 return (0);
 196         }
 197         if (saw_xdigit) {
 198                 if (tp + NS_INT16SZ > endp)
 199                         return (0);
 200                 *tp++ = (u_char) (val >> 8) & 0xff;
 201                 *tp++ = (u_char) val & 0xff;
 202         }
 203         if (colonp != NULL) {
 204                 /*
 205                  * Since some memmove()'s erroneously fail to handle
 206                  * overlapping regions, we'll do the shift by hand.
 207                  */
 208                 const int n = tp - colonp;
 209                 int i;
 210
 211                 if (tp == endp)
 212                         return (0);
 213                 for (i = 1; i <= n; i++) {
 214                         endp[- i] = colonp[n - i];
 215                         colonp[n - i] = 0;
 216                 }
 217                 tp = endp;
 218         }
 219         if (tp != endp)
 220                 return (0);
 221         memcpy(dst, tmp, NS_IN6ADDRSZ);
 222         return (1);
 223 }