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 #ifdef _LIBC
  67 # include <stdlib.h>
  68 # include <limits.h>
  69 # include <errno.h>
  70 #endif
  71 #include "../conf/portability.h"
  72
  73 /* these are compatibility routines, not needed on recent BSD releases */
  74
  75 /*
  76  * Ascii internet address interpretation routine.
  77  * The value returned is in network order.
  78  */
  79 u_int32_t
  80 inet_addr(cp)
  81         register const char *cp;
  82 {
  83         struct in_addr val;
  84
  85         if (inet_aton(cp, &val))
  86                 return (val.s_addr);
  87         return (INADDR_NONE);
  88 }
  89
  90 /*
  91  * Check whether "cp" is a valid ascii representation
  92  * of an Internet address and convert to a binary address.
  93  * Returns 1 if the address is valid, 0 if not.
  94  * This replaces inet_addr, the return value from which
  95  * cannot distinguish between failure and a local broadcast address.
  96  */
  97 int
  98 inet_aton(cp, addr)
  99         const char *cp;
 100         struct in_addr *addr;
 101 {
 102         register u_int32_t val; /* changed from u_long --david */
 103 #ifndef _LIBC
 104         register int base;
 105 #endif
 106         register int n;
 107         register char c;
 108         u_int32_t parts[4];
 109         register u_int32_t *pp = parts;
 110
 111 #ifdef _LIBC
 112         int saved_errno = errno;
 113         __set_errno (0);
 114 #endif
 115
 116         c = *cp;
 117         for (;;) {
 118                 /*
 119                  * Collect number up to ``.''.
 120                  * Values are specified as for C:
 121                  * 0x=hex, 0=octal, isdigit=decimal.
 122                  */
 123                 if (!isdigit(c))
 124                         goto ret_0;
 125 #ifdef _LIBC
 126                 {
 127                         unsigned long ul = strtoul (cp, (char **) &cp, 0);
 128                         if (ul == ULONG_MAX && errno == ERANGE)
 129                                 goto ret_0;
 130                         if (ul > 0xfffffffful)
 131                                 goto ret_0;
 132                         val = ul;
 133                 }
 134                 c = *cp;
 135 #else
 136                 base = 10;
 137                 if (c == '0') {
 138                         c = *++cp;
 139                         if (c == 'x' || c == 'X')
 140                                 base = 16, c = *++cp;
 141                         else
 142                                 base = 8;
 143                 }
 144                 val = 0;
 145                 for (;;) {
 146                         if (isascii(c) && isdigit(c)) {
 147                                 val = (val * base) + (c - '0');
 148                                 c = *++cp;
 149                         } else if (base == 16 && isascii(c) && isxdigit(c)) {
 150                                 val = (val << 4) |
 151                                         (c + 10 - (islower(c) ? 'a' : 'A'));
 152                                 c = *++cp;
 153                         } else
 154                                 break;
 155                 }
 156 #endif
 157                 if (c == '.') {
 158                         /*
 159                          * Internet format:
 160                          *      a.b.c.d
 161                          *      a.b.c   (with c treated as 16 bits)
 162                          *      a.b     (with b treated as 24 bits)
 163                          */
 164                         if (pp >= parts + 3)
 165                                 goto ret_0;
 166                         *pp++ = val;
 167                         c = *++cp;
 168                 } else
 169                         break;
 170         }
 171         /*
 172          * Check for trailing characters.
 173          */
 174         if (c != '\0' && (!isascii(c) || !isspace(c)))
 175                 goto ret_0;
 176         /*
 177          * Concoct the address according to
 178          * the number of parts specified.
 179          */
 180         n = pp - parts + 1;
 181         switch (n) {
 182
 183         case 0:
 184                 goto ret_0;             /* initial nondigit */
 185
 186         case 1:                         /* a -- 32 bits */
 187                 break;
 188
 189         case 2:                         /* a.b -- 8.24 bits */
 190                 if (val > 0xffffff)
 191                         goto ret_0;
 192                 val |= parts[0] << 24;
 193                 break;
 194
 195         case 3:                         /* a.b.c -- 8.8.16 bits */
 196                 if (val > 0xffff)
 197                         goto ret_0;
 198                 val |= (parts[0] << 24) | (parts[1] << 16);
 199                 break;
 200
 201         case 4:                         /* a.b.c.d -- 8.8.8.8 bits */
 202                 if (val > 0xff)
 203                         goto ret_0;
 204                 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
 205                 break;
 206         }
 207         if (addr)
 208                 addr->s_addr = htonl(val);
 209
 210 #ifdef _LIBC
 211         __set_errno (saved_errno);
 212 #endif
 213         return (1);
 214
 215 ret_0:
 216 #ifdef _LIBC
 217         __set_errno (saved_errno);
 218 #endif
 219         return (0);
 220 }