lib/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 "rsync.h"
  19
  20 #define NS_INT16SZ       2
  21 #define NS_INADDRSZ      4
  22 #define NS_IN6ADDRSZ    16
  23
  24 /*
  25  * WARNING: Don't even consider trying to compile this on a system where
  26  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
  27  */
  28
  29 static int inet_pton4(const char *src, unsigned char *dst);
  30 #ifdef INET6
  31 static int inet_pton6(const char *src, unsigned char *dst);
  32 #endif
  33
  34 /* int
  35  * inet_pton(af, src, dst)
  36  *      convert from presentation format (which usually means ASCII printable)
  37  *      to network format (which is usually some kind of binary format).
  38  * return:
  39  *      1 if the address was valid for the specified address family
  40  *      0 if the address wasn't valid (`dst' is untouched in this case)
  41  *      -1 if some other error occurred (`dst' is untouched in this case, too)
  42  * author:
  43  *      Paul Vixie, 1996.
  44  */
  45 int
  46 inet_pton(int af,
  47           const char *src,
  48           void *dst)
  49 {
  50         switch (af) {
  51         case AF_INET:
  52                 return (inet_pton4(src, dst));
  53 #ifdef INET6
  54         case AF_INET6:
  55                 return (inet_pton6(src, dst));
  56 #endif
  57         default:
  58                 errno = EAFNOSUPPORT;
  59                 return (-1);
  60         }
  61         /* NOTREACHED */
  62 }
  63
  64 /* int
  65  * inet_pton4(src, dst)
  66  *      like inet_aton() but without all the hexadecimal and shorthand.
  67  * return:
  68  *      1 if `src' is a valid dotted quad, else 0.
  69  * notice:
  70  *      does not touch `dst' unless it's returning 1.
  71  * author:
  72  *      Paul Vixie, 1996.
  73  */
  74 static int
  75 inet_pton4(src, dst)
  76         const char *src;
  77         unsigned char *dst;
  78 {
  79         static const char digits[] = "0123456789";
  80         int saw_digit, octets, ch;
  81         unsigned char tmp[NS_INADDRSZ], *tp;
  82
  83         saw_digit = 0;
  84         octets = 0;
  85         *(tp = tmp) = 0;
  86         while ((ch = *src++) != '\0') {
  87                 const char *pch;
  88
  89                 if ((pch = strchr(digits, ch)) != NULL) {
  90                         unsigned int new = *tp * 10 + (pch - digits);
  91
  92                         if (new > 255)
  93                                 return (0);
  94                         *tp = new;
  95                         if (! saw_digit) {
  96                                 if (++octets > 4)
  97                                         return (0);
  98                                 saw_digit = 1;
  99                         }
 100                 } else if (ch == '.' && saw_digit) {
 101                         if (octets == 4)
 102                                 return (0);
 103                         *++tp = 0;
 104                         saw_digit = 0;
 105                 } else
 106                         return (0);
 107         }
 108         if (octets < 4)
 109                 return (0);
 110         memcpy(dst, tmp, NS_INADDRSZ);
 111         return (1);
 112 }
 113
 114 /* int
 115  * inet_pton6(src, dst)
 116  *      convert presentation level address to network order binary form.
 117  * return:
 118  *      1 if `src' is a valid [RFC1884 2.2] address, else 0.
 119  * notice:
 120  *      (1) does not touch `dst' unless it's returning 1.
 121  *      (2) :: in a full address is silently ignored.
 122  * credit:
 123  *      inspired by Mark Andrews.
 124  * author:
 125  *      Paul Vixie, 1996.
 126  */
 127 #ifdef INET6
 128 static int
 129 inet_pton6(src, dst)
 130         const char *src;
 131         unsigned char *dst;
 132 {
 133         static const char xdigits_l[] = "0123456789abcdef",
 134                           xdigits_u[] = "0123456789ABCDEF";
 135         unsigned char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
 136         const char *xdigits, *curtok;
 137         int ch, saw_xdigit;
 138         unsigned int val;
 139
 140         memset((tp = tmp), '\0', NS_IN6ADDRSZ);
 141         endp = tp + NS_IN6ADDRSZ;
 142         colonp = NULL;
 143         /* Leading :: requires some special handling. */
 144         if (*src == ':')
 145                 if (*++src != ':')
 146                         return (0);
 147         curtok = src;
 148         saw_xdigit = 0;
 149         val = 0;
 150         while ((ch = *src++) != '\0') {
 151                 const char *pch;
 152
 153                 if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
 154                         pch = strchr((xdigits = xdigits_u), ch);
 155                 if (pch != NULL) {
 156                         val <<= 4;
 157                         val |= (pch - xdigits);
 158                         if (val > 0xffff)
 159                                 return (0);
 160                         saw_xdigit = 1;
 161                         continue;
 162                 }
 163                 if (ch == ':') {
 164                         curtok = src;
 165                         if (!saw_xdigit) {
 166                                 if (colonp)
 167                                         return (0);
 168                                 colonp = tp;
 169                                 continue;
 170                         }
 171                         if (tp + NS_INT16SZ > endp)
 172                                 return (0);
 173                         *tp++ = (unsigned char) (val >> 8) & 0xff;
 174                         *tp++ = (unsigned char) val & 0xff;
 175                         saw_xdigit = 0;
 176                         val = 0;
 177                         continue;
 178                 }
 179                 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
 180                     inet_pton4(curtok, tp) > 0) {
 181                         tp += NS_INADDRSZ;
 182                         saw_xdigit = 0;
 183                         break;  /* '\0' was seen by inet_pton4(). */
 184                 }
 185                 return (0);
 186         }
 187         if (saw_xdigit) {
 188                 if (tp + NS_INT16SZ > endp)
 189                         return (0);
 190                 *tp++ = (unsigned char) (val >> 8) & 0xff;
 191                 *tp++ = (unsigned char) val & 0xff;
 192         }
 193         if (colonp != NULL) {
 194                 /*
 195                  * Since some memmove()'s erroneously fail to handle
 196                  * overlapping regions, we'll do the shift by hand.
 197                  */
 198                 const int n = tp - colonp;
 199                 int i;
 200
 201                 for (i = 1; i <= n; i++) {
 202                         endp[- i] = colonp[n - i];
 203                         colonp[n - i] = 0;
 204                 }
 205                 tp = endp;
 206         }
 207         if (tp != endp)
 208                 return (0);
 209         memcpy(dst, tmp, NS_IN6ADDRSZ);
 210         return (1);
 211 }
 212 #endif