libguile/inet_aton.c

   1 /*
   2  * Copyright (c) 1983, 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
  35    gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
  36
  37 #if defined(LIBC_SCCS) && !defined(lint)
  38 static char sccsid[] = "@(#)inet_addr.c 8.1 (Berkeley) 6/17/93";
  39 #endif /* LIBC_SCCS and not lint */
  40
  41 #include <ctype.h>
  42
  43 #include <sys/param.h>
  44 #include <netinet/in.h>
  45 #include <arpa/inet.h>
  46
  47 #if 0
  48
  49 /*
  50  * Ascii internet address interpretation routine.
  51  * The value returned is in network order.
  52  */
  53 u_long
  54 inet_addr(const char *cp)
  55 {
  56         struct in_addr val;
  57
  58         if (inet_aton(cp, &val))
  59                 return (val.s_addr);
  60         return (INADDR_NONE);
  61 }
  62
  63 #endif
  64
  65 /* We provide this prototype to avoid compiler warnings.  If this ever
  66    conflicts with a declaration in a system header file, we'll find
  67    out, because we should include that header file here.  */
  68 int inet_aton (const char *cp, struct in_addr *addr);
  69
  70 /*
  71  * Check whether "cp" is a valid ascii representation
  72  * of an Internet address and convert to a binary address.
  73  * Returns 1 if the address is valid, 0 if not.
  74  * This replaces inet_addr, the return value from which
  75  * cannot distinguish between failure and a local broadcast address.  */
  76 int
  77 inet_aton(const char *cp_arg, struct in_addr *addr)
  78 {
  79         register unsigned long val;
  80         register int base, n;
  81         register unsigned char c;
  82         register unsigned const char *cp = cp_arg;
  83         unsigned int parts[4];
  84         register unsigned int *pp = parts;
  85
  86         for (;;) {
  87                 /*
  88                  * Collect number up to ``.''.
  89                  * Values are specified as for C:
  90                  * 0x=hex, 0=octal, other=decimal.
  91                  */
  92                 val = 0; base = 10;
  93                 if (*cp == '0') {
  94                         if (*++cp == 'x' || *cp == 'X')
  95                                 base = 16, cp++;
  96                         else
  97                                 base = 8;
  98                 }
  99                 while ((c = *cp) != '\0') {
 100                         if (isascii(c) && isdigit(c)) {
 101                                 val = (val * base) + (c - '0');
 102                                 cp++;
 103                                 continue;
 104                         }
 105                         if (base == 16 && isascii(c) && isxdigit(c)) {
 106                                 val = (val << 4) +
 107                                         (c + 10 - (islower(c) ? 'a' : 'A'));
 108                                 cp++;
 109                                 continue;
 110                         }
 111                         break;
 112                 }
 113                 if (*cp == '.') {
 114                         /*
 115                          * Internet format:
 116                          *      a.b.c.d
 117                          *      a.b.c   (with c treated as 16-bits)
 118                          *      a.b     (with b treated as 24 bits)
 119                          */
 120                         if (pp >= parts + 3 || val > 0xff)
 121                                 return (0);
 122                         *pp++ = val, cp++;
 123                 } else
 124                         break;
 125         }
 126         /*
 127          * Check for trailing characters.
 128          */
 129         if (*cp && (!isascii(*cp) || !isspace(*cp)))
 130                 return (0);
 131         /*
 132          * Concoct the address according to
 133          * the number of parts specified.
 134          */
 135         n = pp - parts + 1;
 136         switch (n) {
 137
 138         case 1:                         /* a -- 32 bits */
 139                 break;
 140
 141         case 2:                         /* a.b -- 8.24 bits */
 142                 if (val > 0xffffff)
 143                         return (0);
 144                 val |= parts[0] << 24;
 145                 break;
 146
 147         case 3:                         /* a.b.c -- 8.8.16 bits */
 148                 if (val > 0xffff)
 149                         return (0);
 150                 val |= (parts[0] << 24) | (parts[1] << 16);
 151                 break;
 152
 153         case 4:                         /* a.b.c.d -- 8.8.8.8 bits */
 154                 if (val > 0xff)
 155                         return (0);
 156                 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
 157                 break;
 158         }
 159         if (addr)
 160                 addr->s_addr = htonl(val);
 161         return (1);
 162 }
 163
 164 /*
 165   Local Variables:
 166   c-file-style: "gnu"
 167   End:
 168 */