lib/liblwres/lwinetpton.c

   1 /*
   2  * Copyright (C) 1996-2001  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
   9  * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
  10  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
  11  * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
  13  * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
  14  * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
  15  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 #if defined(LIBC_SCCS) && !defined(lint)
  19 static char rcsid[] = "$Id: lwinetpton.c,v 1.1 2004/03/15 20:35:25 as Exp $";
  20 #endif /* LIBC_SCCS and not lint */
  21
  22 #include <config.h>
  23
  24 #include <errno.h>
  25 #include <string.h>
  26
  27 #include <lwres/net.h>
  28
  29 #define NS_INT16SZ       2
  30 #define NS_INADDRSZ      4
  31 #define NS_IN6ADDRSZ    16
  32
  33 /*
  34  * WARNING: Don't even consider trying to compile this on a system where
  35  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
  36  */
  37
  38 static int inet_pton4(const char *src, unsigned char *dst);
  39 static int inet_pton6(const char *src, unsigned char *dst);
  40
  41 /* int
  42  * lwres_net_pton(af, src, dst)
  43  *      convert from presentation format (which usually means ASCII printable)
  44  *      to network format (which is usually some kind of binary format).
  45  * return:
  46  *      1 if the address was valid for the specified address family
  47  *      0 if the address wasn't valid (`dst' is untouched in this case)
  48  *      -1 if some other error occurred (`dst' is untouched in this case, too)
  49  * author:
  50  *      Paul Vixie, 1996.
  51  */
  52 int
  53 lwres_net_pton(int af, const char *src, void *dst) {
  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                 errno = EAFNOSUPPORT;
  61                 return (-1);
  62         }
  63         /* NOTREACHED */
  64 }
  65
  66 /* int
  67  * inet_pton4(src, dst)
  68  *      like inet_aton() but without all the hexadecimal 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 inet_pton4(const char *src, unsigned char *dst) {
  78         static const char digits[] = "0123456789";
  79         int saw_digit, octets, ch;
  80         unsigned char tmp[NS_INADDRSZ], *tp;
  81
  82         saw_digit = 0;
  83         octets = 0;
  84         *(tp = tmp) = 0;
  85         while ((ch = *src++) != '\0') {
  86                 const char *pch;
  87
  88                 if ((pch = strchr(digits, ch)) != NULL) {
  89                         unsigned int new = *tp * 10 + (pch - digits);
  90
  91                         if (new > 255)
  92                                 return (0);
  93                         *tp = new;
  94                         if (! saw_digit) {
  95                                 if (++octets > 4)
  96                                         return (0);
  97                                 saw_digit = 1;
  98                         }
  99                 } else if (ch == '.' && saw_digit) {
 100                         if (octets == 4)
 101                                 return (0);
 102                         *++tp = 0;
 103                         saw_digit = 0;
 104                 } else
 105                         return (0);
 106         }
 107         if (octets < 4)
 108                 return (0);
 109         memcpy(dst, tmp, NS_INADDRSZ);
 110         return (1);
 111 }
 112
 113 /* int
 114  * inet_pton6(src, dst)
 115  *      convert presentation level address to network order binary form.
 116  * return:
 117  *      1 if `src' is a valid [RFC1884 2.2] address, else 0.
 118  * notice:
 119  *      (1) does not touch `dst' unless it's returning 1.
 120  *      (2) :: in a full address is silently ignored.
 121  * credit:
 122  *      inspired by Mark Andrews.
 123  * author:
 124  *      Paul Vixie, 1996.
 125  */
 126 static int
 127 inet_pton6(const char *src, unsigned char *dst) {
 128         static const char xdigits_l[] = "0123456789abcdef",
 129                           xdigits_u[] = "0123456789ABCDEF";
 130         unsigned char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
 131         const char *xdigits, *curtok;
 132         int ch, saw_xdigit;
 133         unsigned int val;
 134
 135         memset((tp = tmp), '\0', NS_IN6ADDRSZ);
 136         endp = tp + NS_IN6ADDRSZ;
 137         colonp = NULL;
 138         /* Leading :: requires some special handling. */
 139         if (*src == ':')
 140                 if (*++src != ':')
 141                         return (0);
 142         curtok = src;
 143         saw_xdigit = 0;
 144         val = 0;
 145         while ((ch = *src++) != '\0') {
 146                 const char *pch;
 147
 148                 if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
 149                         pch = strchr((xdigits = xdigits_u), ch);
 150                 if (pch != NULL) {
 151                         val <<= 4;
 152                         val |= (pch - xdigits);
 153                         if (val > 0xffff)
 154                                 return (0);
 155                         saw_xdigit = 1;
 156                         continue;
 157                 }
 158                 if (ch == ':') {
 159                         curtok = src;
 160                         if (!saw_xdigit) {
 161                                 if (colonp)
 162                                         return (0);
 163                                 colonp = tp;
 164                                 continue;
 165                         }
 166                         if (tp + NS_INT16SZ > endp)
 167                                 return (0);
 168                         *tp++ = (unsigned char) (val >> 8) & 0xff;
 169                         *tp++ = (unsigned char) val & 0xff;
 170                         saw_xdigit = 0;
 171                         val = 0;
 172                         continue;
 173                 }
 174                 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
 175                     inet_pton4(curtok, tp) > 0) {
 176                         tp += NS_INADDRSZ;
 177                         saw_xdigit = 0;
 178                         break;  /* '\0' was seen by inet_pton4(). */
 179                 }
 180                 return (0);
 181         }
 182         if (saw_xdigit) {
 183                 if (tp + NS_INT16SZ > endp)
 184                         return (0);
 185                 *tp++ = (unsigned char) (val >> 8) & 0xff;
 186                 *tp++ = (unsigned char) val & 0xff;
 187         }
 188         if (colonp != NULL) {
 189                 /*
 190                  * Since some memmove()'s erroneously fail to handle
 191                  * overlapping regions, we'll do the shift by hand.
 192                  */
 193                 const int n = tp - colonp;
 194                 int i;
 195
 196                 for (i = 1; i <= n; i++) {
 197                         endp[- i] = colonp[n - i];
 198                         colonp[n - i] = 0;
 199                 }
 200                 tp = endp;
 201         }
 202         if (tp != endp)
 203                 return (0);
 204         memcpy(dst, tmp, NS_IN6ADDRSZ);
 205         return (1);
 206 }