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 #include <sys/param.h>
  19 #include <sys/types.h>
  20 #include <sys/socket.h>
  21 #include <netinet/in.h>
  22 #include <arpa/inet.h>
  23 #include <arpa/nameser.h>
  24 #include <ctype.h>
  25 #include <string.h>
  26 #include <errno.h>
  27
  28 /*
  29  * WARNING: Don't even consider trying to compile this on a system where
  30  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
  31  */
  32
  33 static int inet_pton4 (const char *src, u_char *dst) internal_function;
  34 static int inet_pton6 (const char *src, u_char *dst) internal_function;
  35
  36 /* int
  37  * inet_pton(af, src, dst)
  38  *      convert from presentation format (which usually means ASCII printable)
  39  *      to network format (which is usually some kind of binary format).
  40  * return:
  41  *      1 if the address was valid for the specified address family
  42  *      0 if the address wasn't valid (`dst' is untouched in this case)
  43  *      -1 if some other error occurred (`dst' is untouched in this case, too)
  44  * author:
  45  *      Paul Vixie, 1996.
  46  */
  47 int
  48 __inet_pton (int af, const char *src, void *dst)
  49 {
  50         switch (af) {
  51         case AF_INET:
  52                 return (inet_pton4(src, dst));
  53         case AF_INET6:
  54                 return (inet_pton6(src, dst));
  55         default:
  56                 __set_errno (EAFNOSUPPORT);
  57                 return (-1);
  58         }
  59         /* NOTREACHED */
  60 }
  61 libc_hidden_def (__inet_pton)
  62 weak_alias (__inet_pton, inet_pton)
  63 libc_hidden_weak (inet_pton)
  64
  65 /* int
  66  * inet_pton4(src, dst)
  67  *      like inet_aton() but without all the hexadecimal, octal (with the
  68  *      exception of 0) and shorthand.
  69  * return:
  70  *      1 if `src' is a valid dotted quad, else 0.
  71  * notice:
  72  *      does not touch `dst' unless it's returning 1.
  73  * author:
  74  *      Paul Vixie, 1996.
  75  */
  76 static int
  77 internal_function
  78 inet_pton4 (const char *src, u_char *dst)
  79 {
  80         int saw_digit, octets, ch;
  81         u_char tmp[NS_INADDRSZ], *tp;
  82
  83         saw_digit = 0;
  84         octets = 0;
  85         *(tp = tmp) = 0;
  86         while ((ch = *src++) != '\0') {
  87
  88                 if (ch >= '0' && ch <= '9') {
  89                         u_int new = *tp * 10 + (ch - '0');
  90
  91                         if (saw_digit && *tp == 0)
  92                                 return (0);
  93                         if (new > 255)
  94                                 return (0);
  95                         *tp = new;
  96                         if (! saw_digit) {
  97                                 if (++octets > 4)
  98                                         return (0);
  99                                 saw_digit = 1;
 100                         }
 101                 } else if (ch == '.' && saw_digit) {
 102                         if (octets == 4)
 103                                 return (0);
 104                         *++tp = 0;
 105                         saw_digit = 0;
 106                 } else
 107                         return (0);
 108         }
 109         if (octets < 4)
 110                 return (0);
 111         memcpy(dst, tmp, NS_INADDRSZ);
 112         return (1);
 113 }
 114
 115 /* int
 116  * inet_pton6(src, dst)
 117  *      convert presentation level address to network order binary form.
 118  * return:
 119  *      1 if `src' is a valid [RFC1884 2.2] address, else 0.
 120  * notice:
 121  *      (1) does not touch `dst' unless it's returning 1.
 122  *      (2) :: in a full address is silently ignored.
 123  * credit:
 124  *      inspired by Mark Andrews.
 125  * author:
 126  *      Paul Vixie, 1996.
 127  */
 128 static int
 129 internal_function
 130 inet_pton6 (const char *src, u_char *dst)
 131 {
 132         static const char xdigits[] = "0123456789abcdef";
 133         u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
 134         const char *curtok;
 135         int ch, saw_xdigit;
 136         u_int val;
 137
 138         tp = memset(tmp, '\0', NS_IN6ADDRSZ);
 139         endp = tp + NS_IN6ADDRSZ;
 140         colonp = NULL;
 141         /* Leading :: requires some special handling. */
 142         if (*src == ':')
 143                 if (*++src != ':')
 144                         return (0);
 145         curtok = src;
 146         saw_xdigit = 0;
 147         val = 0;
 148         while ((ch = tolower (*src++)) != '\0') {
 149                 const char *pch;
 150
 151                 pch = strchr(xdigits, ch);
 152                 if (pch != NULL) {
 153                         val <<= 4;
 154                         val |= (pch - xdigits);
 155                         if (val > 0xffff)
 156                                 return (0);
 157                         saw_xdigit = 1;
 158                         continue;
 159                 }
 160                 if (ch == ':') {
 161                         curtok = src;
 162                         if (!saw_xdigit) {
 163                                 if (colonp)
 164                                         return (0);
 165                                 colonp = tp;
 166                                 continue;
 167                         } else if (*src == '\0') {
 168                                 return (0);
 169                         }
 170                         if (tp + NS_INT16SZ > endp)
 171                                 return (0);
 172                         *tp++ = (u_char) (val >> 8) & 0xff;
 173                         *tp++ = (u_char) val & 0xff;
 174                         saw_xdigit = 0;
 175                         val = 0;
 176                         continue;
 177                 }
 178                 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
 179                     inet_pton4(curtok, tp) > 0) {
 180                         tp += NS_INADDRSZ;
 181                         saw_xdigit = 0;
 182                         break;  /* '\0' was seen by inet_pton4(). */
 183                 }
 184                 return (0);
 185         }
 186         if (saw_xdigit) {
 187                 if (tp + NS_INT16SZ > endp)
 188                         return (0);
 189                 *tp++ = (u_char) (val >> 8) & 0xff;
 190                 *tp++ = (u_char) val & 0xff;
 191         }
 192         if (colonp != NULL) {
 193                 /*
 194                  * Since some memmove()'s erroneously fail to handle
 195                  * overlapping regions, we'll do the shift by hand.
 196                  */
 197                 const int n = tp - colonp;
 198                 int i;
 199
 200                 if (tp == endp)
 201                         return (0);
 202                 for (i = 1; i <= n; i++) {
 203                         endp[- i] = colonp[n - i];
 204                         colonp[n - i] = 0;
 205                 }
 206                 tp = endp;
 207         }
 208         if (tp != endp)
 209                 return (0);
 210         memcpy(dst, tmp, NS_IN6ADDRSZ);
 211         return (1);
 212 }