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/param.h>
  62 #include <netinet/in.h>
  63 #include <arpa/inet.h>
  64 #include <ctype.h>
  65 #include "../conf/portability.h"
  66
  67 /* these are compatibility routines, not needed on recent BSD releases */
  68
  69 /*
  70  * Ascii internet address interpretation routine.
  71  * The value returned is in network order.
  72  */
  73 u_long
  74 inet_addr(cp)
  75         register const char *cp;
  76 {
  77         struct in_addr val;
  78
  79         if (inet_aton(cp, &val))
  80                 return (val.s_addr);
  81         return (INADDR_NONE);
  82 }
  83
  84 /*
  85  * Check whether "cp" is a valid ascii representation
  86  * of an Internet address and convert to a binary address.
  87  * Returns 1 if the address is valid, 0 if not.
  88  * This replaces inet_addr, the return value from which
  89  * cannot distinguish between failure and a local broadcast address.
  90  */
  91 int
  92 inet_aton(cp, addr)
  93         register const char *cp;
  94         struct in_addr *addr;
  95 {
  96         register u_int32_t val; /* changed from u_long --david */
  97         register int base, n;
  98         register char c;
  99         u_int parts[4];
 100         register u_int *pp = parts;
 101
 102         c = *cp;
 103         for (;;) {
 104                 /*
 105                  * Collect number up to ``.''.
 106                  * Values are specified as for C:
 107                  * 0x=hex, 0=octal, isdigit=decimal.
 108                  */
 109                 if (!isdigit(c))
 110                         return (0);
 111                 val = 0; base = 10;
 112                 if (c == '0') {
 113                         c = *++cp;
 114                         if (c == 'x' || c == 'X')
 115                                 base = 16, c = *++cp;
 116                         else
 117                                 base = 8;
 118                 }
 119                 for (;;) {
 120                         if (isascii(c) && isdigit(c)) {
 121                                 val = (val * base) + (c - '0');
 122                                 c = *++cp;
 123                         } else if (base == 16 && isascii(c) && isxdigit(c)) {
 124                                 val = (val << 4) |
 125                                         (c + 10 - (islower(c) ? 'a' : 'A'));
 126                                 c = *++cp;
 127                         } else
 128                                 break;
 129                 }
 130                 if (c == '.') {
 131                         /*
 132                          * Internet format:
 133                          *      a.b.c.d
 134                          *      a.b.c   (with c treated as 16 bits)
 135                          *      a.b     (with b treated as 24 bits)
 136                          */
 137                         if (pp >= parts + 3)
 138                                 return (0);
 139                         *pp++ = val;
 140                         c = *++cp;
 141                 } else
 142                         break;
 143         }
 144         /*
 145          * Check for trailing characters.
 146          */
 147         if (c != '\0' && (!isascii(c) || !isspace(c)))
 148                 return (0);
 149         /*
 150          * Concoct the address according to
 151          * the number of parts specified.
 152          */
 153         n = pp - parts + 1;
 154         switch (n) {
 155
 156         case 0:
 157                 return (0);             /* initial nondigit */
 158
 159         case 1:                         /* a -- 32 bits */
 160                 break;
 161
 162         case 2:                         /* a.b -- 8.24 bits */
 163                 if (val > 0xffffff)
 164                         return (0);
 165                 val |= parts[0] << 24;
 166                 break;
 167
 168         case 3:                         /* a.b.c -- 8.8.16 bits */
 169                 if (val > 0xffff)
 170                         return (0);
 171                 val |= (parts[0] << 24) | (parts[1] << 16);
 172                 break;
 173
 174         case 4:                         /* a.b.c.d -- 8.8.8.8 bits */
 175                 if (val > 0xff)
 176                         return (0);
 177                 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
 178                 break;
 179         }
 180         if (addr)
 181                 addr->s_addr = htonl(val);
 182         return (1);
 183 }