lib/replace/inet_pton.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 #include "replace.h"
  19 #include "system/network.h"
  20
  21 #define NS_INT16SZ       2
  22 #define NS_INADDRSZ      4
  23 #define NS_IN6ADDRSZ    16
  24
  25 /*
  26  * WARNING: Don't even consider trying to compile this on a system where
  27  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
  28  */
  29
  30 static int inet_pton4(const char *src, unsigned char *dst);
  31 #ifdef AF_INET6
  32 static int inet_pton6(const char *src, unsigned char *dst);
  33 #endif
  34
  35 /* int
  36  * inet_pton(af, src, dst)
  37  *      convert from presentation format (which usually means ASCII printable)
  38  *      to network format (which is usually some kind of binary format).
  39  * return:
  40  *      1 if the address was valid for the specified address family
  41  *      0 if the address wasn't valid (`dst' is untouched in this case)
  42  *      -1 if some other error occurred (`dst' is untouched in this case, too)
  43  * author:
  44  *      Paul Vixie, 1996.
  45  */
  46 int
  47 rep_inet_pton(int af,
  48           const char *src,
  49           void *dst)
  50 {
  51         switch (af) {
  52         case AF_INET:
  53                 return (inet_pton4(src, dst));
  54 #ifdef AF_INET6
  55         case AF_INET6:
  56                 return (inet_pton6(src, dst));
  57 #endif
  58         default:
  59                 errno = EAFNOSUPPORT;
  60                 return (-1);
  61         }
  62         /* NOTREACHED */
  63 }
  64
  65 /* int
  66  * inet_pton4(src, dst)
  67  *      like inet_aton() but without all the hexadecimal and shorthand.
  68  * return:
  69  *      1 if `src' is a valid dotted quad, else 0.
  70  * notice:
  71  *      does not touch `dst' unless it's returning 1.
  72  * author:
  73  *      Paul Vixie, 1996.
  74  */
  75 static int
  76 inet_pton4(src, dst)
  77         const char *src;
  78         unsigned char *dst;
  79 {
  80         static const char digits[] = "0123456789";
  81         int saw_digit, octets, ch;
  82         unsigned char tmp[NS_INADDRSZ], *tp;
  83
  84         saw_digit = 0;
  85         octets = 0;
  86         *(tp = tmp) = 0;
  87         while ((ch = *src++) != '\0') {
  88                 const char *pch;
  89
  90                 if ((pch = strchr(digits, ch)) != NULL) {
  91                         unsigned int new = *tp * 10 + (pch - digits);
  92
  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 #ifdef AF_INET6
 129 static int
 130 inet_pton6(src, dst)
 131         const char *src;
 132         unsigned char *dst;
 133 {
 134         static const char xdigits_l[] = "0123456789abcdef",
 135                           xdigits_u[] = "0123456789ABCDEF";
 136         unsigned char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
 137         const char *xdigits, *curtok;
 138         int ch, saw_xdigit;
 139         unsigned int val;
 140
 141         memset((tp = tmp), '\0', NS_IN6ADDRSZ);
 142         endp = tp + NS_IN6ADDRSZ;
 143         colonp = NULL;
 144         /* Leading :: requires some special handling. */
 145         if (*src == ':')
 146                 if (*++src != ':')
 147                         return (0);
 148         curtok = src;
 149         saw_xdigit = 0;
 150         val = 0;
 151         while ((ch = *src++) != '\0') {
 152                 const char *pch;
 153
 154                 if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
 155                         pch = strchr((xdigits = xdigits_u), 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                         }
 172                         if (tp + NS_INT16SZ > endp)
 173                                 return (0);
 174                         *tp++ = (unsigned char) (val >> 8) & 0xff;
 175                         *tp++ = (unsigned char) val & 0xff;
 176                         saw_xdigit = 0;
 177                         val = 0;
 178                         continue;
 179                 }
 180                 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
 181                     inet_pton4(curtok, tp) > 0) {
 182                         tp += NS_INADDRSZ;
 183                         saw_xdigit = 0;
 184                         break;  /* '\0' was seen by inet_pton4(). */
 185                 }
 186                 return (0);
 187         }
 188         if (saw_xdigit) {
 189                 if (tp + NS_INT16SZ > endp)
 190                         return (0);
 191                 *tp++ = (unsigned char) (val >> 8) & 0xff;
 192                 *tp++ = (unsigned char) val & 0xff;
 193         }
 194         if (colonp != NULL) {
 195                 /*
 196                  * Since some memmove()'s erroneously fail to handle
 197                  * overlapping regions, we'll do the shift by hand.
 198                  */
 199                 const int n = tp - colonp;
 200                 int i;
 201
 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 }
 213 #endif