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  * 4. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  * -
  31  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
  32  *
  33  * Permission to use, copy, modify, and distribute this software for any
  34  * purpose with or without fee is hereby granted, provided that the above
  35  * copyright notice and this permission notice appear in all copies, and that
  36  * the name of Digital Equipment Corporation not be used in advertising or
  37  * publicity pertaining to distribution of the document or software without
  38  * specific, written prior permission.
  39  *
  40  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
  41  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
  42  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
  43  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  44  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  45  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  46  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  47  * SOFTWARE.
  48  * -
  49  * --Copyright--
  50  */
  51
  52 #if defined(LIBC_SCCS) && !defined(lint)
  53 static char sccsid[] = "@(#)inet_addr.c 8.1 (Berkeley) 6/17/93";
  54 static char rcsid[] = "$Id$";
  55 #endif /* LIBC_SCCS and not lint */
  56
  57 #include <sys/types.h>
  58 #include <sys/param.h>
  59 #include <netinet/in.h>
  60 #include <arpa/inet.h>
  61 #include <ctype.h>
  62 #ifdef _LIBC
  63 # include <endian.h>
  64 # include <stdint.h>
  65 # include <stdlib.h>
  66 # include <limits.h>
  67 # include <errno.h>
  68 #endif
  69 #include "../conf/portability.h"
  70
  71 /* these are compatibility routines, not needed on recent BSD releases */
  72
  73 /*
  74  * Ascii internet address interpretation routine.
  75  * The value returned is in network order.
  76  */
  77 u_int32_t
  78 inet_addr(cp)
  79         register const char *cp;
  80 {
  81         struct in_addr val;
  82
  83         if (inet_aton(cp, &val))
  84                 return (val.s_addr);
  85         return (INADDR_NONE);
  86 }
  87
  88 /*
  89  * Check whether "cp" is a valid ascii representation
  90  * of an Internet address and convert to a binary address.
  91  * Returns 1 if the address is valid, 0 if not.
  92  * This replaces inet_addr, the return value from which
  93  * cannot distinguish between failure and a local broadcast address.
  94  */
  95 int
  96 inet_aton(cp, addr)
  97         const char *cp;
  98         struct in_addr *addr;
  99 {
 100         static const u_int32_t max[4] = { 0xffffffff, 0xffffff, 0xffff, 0xff };
 101         register u_int32_t val; /* changed from u_long --david */
 102 #ifndef _LIBC
 103         register int base;
 104 #endif
 105         register char c;
 106         union iaddr {
 107           uint8_t bytes[4];
 108           uint32_t word;
 109         } res;
 110         register uint8_t *pp = res.bytes;
 111         int digit;
 112
 113 #ifdef _LIBC
 114         int saved_errno = errno;
 115         __set_errno (0);
 116 #endif
 117
 118         res.word = 0;
 119
 120         c = *cp;
 121         for (;;) {
 122                 /*
 123                  * Collect number up to ``.''.
 124                  * Values are specified as for C:
 125                  * 0x=hex, 0=octal, isdigit=decimal.
 126                  */
 127                 if (!isdigit(c))
 128                         goto ret_0;
 129 #ifdef _LIBC
 130                 {
 131                         char *endp;
 132                         unsigned long ul = strtoul (cp, (char **) &endp, 0);
 133                         if (ul == ULONG_MAX && errno == ERANGE)
 134                                 goto ret_0;
 135                         if (ul > 0xfffffffful)
 136                                 goto ret_0;
 137                         val = ul;
 138                         digit = cp != endp;
 139                         cp = endp;
 140                 }
 141                 c = *cp;
 142 #else
 143                 base = 10;
 144                 if (c == '0') {
 145                         c = *++cp;
 146                         if (c == 'x' || c == 'X')
 147                                 base = 16, c = *++cp;
 148                         else
 149                                 base = 8;
 150                 }
 151                 val = 0;
 152                 for (;;) {
 153                         if (isascii(c) && isdigit(c)) {
 154                                 val = (val * base) + (c - '0');
 155                                 c = *++cp;
 156                         } else if (base == 16 && isascii(c) && isxdigit(c)) {
 157                                 val = (val << 4) |
 158                                         (c + 10 - (islower(c) ? 'a' : 'A'));
 159                                 c = *++cp;
 160                         } else
 161                                 break;
 162                 }
 163 #endif
 164                 if (c == '.') {
 165                         /*
 166                          * Internet format:
 167                          *      a.b.c.d
 168                          *      a.b.c   (with c treated as 16 bits)
 169                          *      a.b     (with b treated as 24 bits)
 170                          */
 171                         if (pp > res.bytes + 3
 172                             || val > 0xff)
 173                                 goto ret_0;
 174                         *pp++ = val;
 175                         c = *++cp;
 176                 } else
 177                         break;
 178         }
 179         /*
 180          * Check for trailing characters.
 181          */
 182         if (c != '\0' && (!isascii(c) || !isspace(c)))
 183                 goto ret_0;
 184
 185         /*
 186          * Did we get a valid digit?
 187          */
 188         if (!digit)
 189                 goto ret_0;
 190
 191         /* Check whether the last part is in its limits depending on
 192            the number of parts in total.  */
 193         if (val > max[pp - res.bytes])
 194           goto ret_0;
 195
 196         if (addr)
 197                 addr->s_addr = res.word | htonl (val);
 198
 199 #ifdef _LIBC
 200         __set_errno (saved_errno);
 201 #endif
 202         return (1);
 203
 204 ret_0:
 205 #ifdef _LIBC
 206         __set_errno (saved_errno);
 207 #endif
 208         return (0);
 209 }