resolv/inet_addr.c

   1 /*
   2  * ++Copyright++ 1983, 1990, 1993
   3  * -
   4  * Copyright (c) 1983, 1990, 1993
   5  *    The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by the University of
  18  *      California, Berkeley and its contributors.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  * -
  35  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
  36  *
  37  * Permission to use, copy, modify, and distribute this software for any
  38  * purpose with or without fee is hereby granted, provided that the above
  39  * copyright notice and this permission notice appear in all copies, and that
  40  * the name of Digital Equipment Corporation not be used in advertising or
  41  * publicity pertaining to distribution of the document or software without
  42  * specific, written prior permission.
  43  *
  44  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
  45  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
  46  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
  47  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  48  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  49  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  50  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  51  * SOFTWARE.
  52  * -
  53  * --Copyright--
  54  */
  55
  56 #if defined(LIBC_SCCS) && !defined(lint)
  57 static char sccsid[] = "@(#)inet_addr.c 8.1 (Berkeley) 6/17/93";
  58 static char rcsid[] = "$Id$";
  59 #endif /* LIBC_SCCS and not lint */
  60
  61 #include <sys/types.h>
  62 #include <sys/param.h>
  63 #include <netinet/in.h>
  64 #include <arpa/inet.h>
  65 #include <ctype.h>
  66 #include "../conf/portability.h"
  67
  68 /* these are compatibility routines, not needed on recent BSD releases */
  69
  70 /*
  71  * Ascii internet address interpretation routine.
  72  * The value returned is in network order.
  73  */
  74 u_long
  75 inet_addr(cp)
  76         register const char *cp;
  77 {
  78         struct in_addr val;
  79
  80         if (inet_aton(cp, &val))
  81                 return (val.s_addr);
  82         return (INADDR_NONE);
  83 }
  84
  85 /*
  86  * Check whether "cp" is a valid ascii representation
  87  * of an Internet address and convert to a binary address.
  88  * Returns 1 if the address is valid, 0 if not.
  89  * This replaces inet_addr, the return value from which
  90  * cannot distinguish between failure and a local broadcast address.
  91  */
  92 int
  93 inet_aton(cp, addr)
  94         register const char *cp;
  95         struct in_addr *addr;
  96 {
  97         register u_int32_t val; /* changed from u_long --david */
  98         register int base, n;
  99         register char c;
 100         u_int parts[4];
 101         register u_int *pp = parts;
 102
 103         c = *cp;
 104         for (;;) {
 105                 /*
 106                  * Collect number up to ``.''.
 107                  * Values are specified as for C:
 108                  * 0x=hex, 0=octal, isdigit=decimal.
 109                  */
 110                 if (!isdigit(c))
 111                         return (0);
 112                 val = 0; base = 10;
 113                 if (c == '0') {
 114                         c = *++cp;
 115                         if (c == 'x' || c == 'X')
 116                                 base = 16, c = *++cp;
 117                         else
 118                                 base = 8;
 119                 }
 120                 for (;;) {
 121                         if (isascii(c) && isdigit(c)) {
 122                                 val = (val * base) + (c - '0');
 123                                 c = *++cp;
 124                         } else if (base == 16 && isascii(c) && isxdigit(c)) {
 125                                 val = (val << 4) |
 126                                         (c + 10 - (islower(c) ? 'a' : 'A'));
 127                                 c = *++cp;
 128                         } else
 129                                 break;
 130                 }
 131                 if (c == '.') {
 132                         /*
 133                          * Internet format:
 134                          *      a.b.c.d
 135                          *      a.b.c   (with c treated as 16 bits)
 136                          *      a.b     (with b treated as 24 bits)
 137                          */
 138                         if (pp >= parts + 3)
 139                                 return (0);
 140                         *pp++ = val;
 141                         c = *++cp;
 142                 } else
 143                         break;
 144         }
 145         /*
 146          * Check for trailing characters.
 147          */
 148         if (c != '\0' && (!isascii(c) || !isspace(c)))
 149                 return (0);
 150         /*
 151          * Concoct the address according to
 152          * the number of parts specified.
 153          */
 154         n = pp - parts + 1;
 155         switch (n) {
 156
 157         case 0:
 158                 return (0);             /* initial nondigit */
 159
 160         case 1:                         /* a -- 32 bits */
 161                 break;
 162
 163         case 2:                         /* a.b -- 8.24 bits */
 164                 if (val > 0xffffff)
 165                         return (0);
 166                 val |= parts[0] << 24;
 167                 break;
 168
 169         case 3:                         /* a.b.c -- 8.8.16 bits */
 170                 if (val > 0xffff)
 171                         return (0);
 172                 val |= (parts[0] << 24) | (parts[1] << 16);
 173                 break;
 174
 175         case 4:                         /* a.b.c.d -- 8.8.8.8 bits */
 176                 if (val > 0xff)
 177                         return (0);
 178                 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
 179                 break;
 180         }
 181         if (addr)
 182                 addr->s_addr = htonl(val);
 183         return (1);
 184 }