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 (int af, const char *src, void *dst)
  53 {
  54         switch (af) {
  55         case AF_INET:
  56                 return (inet_pton4(src, dst));
  57         case AF_INET6:
  58                 return (inet_pton6(src, dst));
  59         default:
  60                 __set_errno (EAFNOSUPPORT);
  61                 return (-1);
  62         }
  63         /* NOTREACHED */
  64 }
  65 libc_hidden_def (__inet_pton)
  66 weak_alias (__inet_pton, inet_pton)
  67 libc_hidden_weak (inet_pton)
  68
  69 /* int
  70  * inet_pton4(src, dst)
  71  *      like inet_aton() but without all the hexadecimal, octal (with the
  72  *      exception of 0) and shorthand.
  73  * return:
  74  *      1 if `src' is a valid dotted quad, else 0.
  75  * notice:
  76  *      does not touch `dst' unless it's returning 1.
  77  * author:
  78  *      Paul Vixie, 1996.
  79  */
  80 static int
  81 internal_function
  82 inet_pton4 (const char *src, u_char *dst)
  83 {
  84         int saw_digit, octets, ch;
  85         u_char tmp[NS_INADDRSZ], *tp;
  86
  87         saw_digit = 0;
  88         octets = 0;
  89         *(tp = tmp) = 0;
  90         while ((ch = *src++) != '\0') {
  91
  92                 if (ch >= '0' && ch <= '9') {
  93                         u_int new = *tp * 10 + (ch - '0');
  94
  95                         if (saw_digit && *tp == 0)
  96                                 return (0);
  97                         if (new > 255)
  98                                 return (0);
  99                         *tp = new;
 100                         if (! saw_digit) {
 101                                 if (++octets > 4)
 102                                         return (0);
 103                                 saw_digit = 1;
 104                         }
 105                 } else if (ch == '.' && saw_digit) {
 106                         if (octets == 4)
 107                                 return (0);
 108                         *++tp = 0;
 109                         saw_digit = 0;
 110                 } else
 111                         return (0);
 112         }
 113         if (octets < 4)
 114                 return (0);
 115         memcpy(dst, tmp, NS_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 (const char *src, u_char *dst)
 135 {
 136         static const char xdigits[] = "0123456789abcdef";
 137         u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
 138         const char *curtok;
 139         int ch, saw_xdigit;
 140         u_int val;
 141
 142         tp = memset(tmp, '\0', NS_IN6ADDRSZ);
 143         endp = tp + NS_IN6ADDRSZ;
 144         colonp = NULL;
 145         /* Leading :: requires some special handling. */
 146         if (*src == ':')
 147                 if (*++src != ':')
 148                         return (0);
 149         curtok = src;
 150         saw_xdigit = 0;
 151         val = 0;
 152         while ((ch = tolower (*src++)) != '\0') {
 153                 const char *pch;
 154
 155                 pch = strchr(xdigits, ch);
 156                 if (pch != NULL) {
 157                         val <<= 4;
 158                         val |= (pch - xdigits);
 159                         if (val > 0xffff)
 160                                 return (0);
 161                         saw_xdigit = 1;
 162                         continue;
 163                 }
 164                 if (ch == ':') {
 165                         curtok = src;
 166                         if (!saw_xdigit) {
 167                                 if (colonp)
 168                                         return (0);
 169                                 colonp = tp;
 170                                 continue;
 171                         } else if (*src == '\0') {
 172                                 return (0);
 173                         }
 174                         if (tp + NS_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 + NS_INADDRSZ) <= endp) &&
 183                     inet_pton4(curtok, tp) > 0) {
 184                         tp += NS_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 + NS_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                 if (tp == endp)
 205                         return (0);
 206                 for (i = 1; i <= n; i++) {
 207                         endp[- i] = colonp[n - i];
 208                         colonp[n - i] = 0;
 209                 }
 210                 tp = endp;
 211         }
 212         if (tp != endp)
 213                 return (0);
 214         memcpy(dst, tmp, NS_IN6ADDRSZ);
 215         return (1);
 216 }