src/port/inet_aton.c

   1 /* $PostgreSQL$
   2  *
   3  *      This inet_aton() function was taken from the GNU C library and
   4  *      incorporated into Postgres for those systems which do not have this
   5  *      routine in their standard C libraries.
   6  *
   7  *      The function was been extracted whole from the file inet_aton.c in
   8  *      Release 5.3.12 of the Linux C library, which is derived from the
   9  *      GNU C library, by Bryan Henderson in October 1996.      The copyright
  10  *      notice from that file is below.
  11  */
  12
  13 /*
  14  * Copyright (c) 1983, 1990, 1993
  15  *              The Regents of the University of California.  All rights reserved.
  16  *
  17  * Redistribution and use in source and binary forms, with or without
  18  * modification, are permitted provided that the following conditions
  19  * are met:
  20  * 1. Redistributions of source code must retain the above copyright
  21  *        notice, this list of conditions and the following disclaimer.
  22  * 2. Redistributions in binary form must reproduce the above copyright
  23  *        notice, this list of conditions and the following disclaimer in the
  24  *        documentation and/or other materials provided with the distribution.
  25  * 3. Neither the name of the University nor the names of its contributors
  26  *        may be used to endorse or promote products derived from this software
  27  *        without specific prior written permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  32  * ARE DISCLAIMED.      IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  39  * SUCH DAMAGE.  */
  40
  41 #include "c.h"
  42
  43 #include <netinet/in.h>
  44 #include <ctype.h>
  45
  46 /*
  47  * Check whether "cp" is a valid ascii representation
  48  * of an Internet address and convert to a binary address.
  49  * Returns 1 if the address is valid, 0 if not.
  50  * This replaces inet_addr, the return value from which
  51  * cannot distinguish between failure and a local broadcast address.
  52  */
  53 int
  54 inet_aton(const char *cp, struct in_addr * addr)
  55 {
  56         unsigned int val;
  57         int                     base,
  58                                 n;
  59         char            c;
  60         u_int           parts[4];
  61         u_int      *pp = parts;
  62
  63         for (;;)
  64         {
  65                 /*
  66                  * Collect number up to ``.''. Values are specified as for C: 0x=hex,
  67                  * 0=octal, other=decimal.
  68                  */
  69                 val = 0;
  70                 base = 10;
  71                 if (*cp == '0')
  72                 {
  73                         if (*++cp == 'x' || *cp == 'X')
  74                                 base = 16, cp++;
  75                         else
  76                                 base = 8;
  77                 }
  78                 while ((c = *cp) != '\0')
  79                 {
  80                         if (isdigit((unsigned char) c))
  81                         {
  82                                 val = (val * base) + (c - '0');
  83                                 cp++;
  84                                 continue;
  85                         }
  86                         if (base == 16 && isxdigit((unsigned char) c))
  87                         {
  88                                 val = (val << 4) +
  89                                         (c + 10 - (islower((unsigned char) c) ? 'a' : 'A'));
  90                                 cp++;
  91                                 continue;
  92                         }
  93                         break;
  94                 }
  95                 if (*cp == '.')
  96                 {
  97                         /*
  98                          * Internet format: a.b.c.d a.b.c       (with c treated as 16-bits)
  99                          * a.b     (with b treated as 24 bits)
 100                          */
 101                         if (pp >= parts + 3 || val > 0xff)
 102                                 return 0;
 103                         *pp++ = val, cp++;
 104                 }
 105                 else
 106                         break;
 107         }
 108
 109         /*
 110          * Check for trailing junk.
 111          */
 112         while (*cp)
 113                 if (!isspace((unsigned char) *cp++))
 114                         return 0;
 115
 116         /*
 117          * Concoct the address according to the number of parts specified.
 118          */
 119         n = pp - parts + 1;
 120         switch (n)
 121         {
 122
 123                 case 1:                 /* a -- 32 bits */
 124                         break;
 125
 126                 case 2:                 /* a.b -- 8.24 bits */
 127                         if (val > 0xffffff)
 128                                 return 0;
 129                         val |= parts[0] << 24;
 130                         break;
 131
 132                 case 3:                 /* a.b.c -- 8.8.16 bits */
 133                         if (val > 0xffff)
 134                                 return 0;
 135                         val |= (parts[0] << 24) | (parts[1] << 16);
 136                         break;
 137
 138                 case 4:                 /* a.b.c.d -- 8.8.8.8 bits */
 139                         if (val > 0xff)
 140                                 return 0;
 141                         val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
 142                         break;
 143         }
 144         if (addr)
 145                 addr->s_addr = htonl(val);
 146         return 1;
 147 }