resolv/inet_addr.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  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  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
  50 /*
  51  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
  52  *
  53  * Permission to use, copy, modify, and distribute this software for any
  54  * purpose with or without fee is hereby granted, provided that the above
  55  * copyright notice and this permission notice appear in all copies.
  56  *
  57  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
  58  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  59  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  60  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  61  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  62  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  63  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  64  * SOFTWARE.
  65  */
  66
  67 #include <sys/types.h>
  68 #include <sys/param.h>
  69
  70 #include <netinet/in.h>
  71 #include <arpa/inet.h>
  72
  73 #include <ctype.h>
  74
  75 #include <endian.h>
  76 #include <stdint.h>
  77 #include <stdlib.h>
  78 #include <limits.h>
  79 #include <errno.h>
  80
  81 /*
  82  * Ascii internet address interpretation routine.
  83  * The value returned is in network order.
  84  */
  85 in_addr_t
  86 __inet_addr(const char *cp) {
  87         struct in_addr val;
  88
  89         if (__inet_aton(cp, &val))
  90                 return (val.s_addr);
  91         return (INADDR_NONE);
  92 }
  93 weak_alias (__inet_addr, inet_addr)
  94
  95 /*
  96  * Check whether "cp" is a valid ascii representation
  97  * of an Internet address and convert to a binary address.
  98  * Returns 1 if the address is valid, 0 if not.
  99  * This replaces inet_addr, the return value from which
 100  * cannot distinguish between failure and a local broadcast address.
 101  */
 102 int
 103 __inet_aton(const char *cp, struct in_addr *addr)
 104 {
 105         static const in_addr_t max[4] = { 0xffffffff, 0xffffff, 0xffff, 0xff };
 106         in_addr_t val;
 107         char c;
 108         union iaddr {
 109           uint8_t bytes[4];
 110           uint32_t word;
 111         } res;
 112         uint8_t *pp = res.bytes;
 113         int digit;
 114
 115         int saved_errno = errno;
 116         __set_errno (0);
 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                 {
 130                         char *endp;
 131                         unsigned long ul = strtoul (cp, (char **) &endp, 0);
 132                         if (ul == ULONG_MAX && errno == ERANGE)
 133                                 goto ret_0;
 134                         if (ul > 0xfffffffful)
 135                                 goto ret_0;
 136                         val = ul;
 137                         digit = cp != endp;
 138                         cp = endp;
 139                 }
 140                 c = *cp;
 141                 if (c == '.') {
 142                         /*
 143                          * Internet format:
 144                          *      a.b.c.d
 145                          *      a.b.c   (with c treated as 16 bits)
 146                          *      a.b     (with b treated as 24 bits)
 147                          */
 148                         if (pp > res.bytes + 2 || val > 0xff)
 149                                 goto ret_0;
 150                         *pp++ = val;
 151                         c = *++cp;
 152                 } else
 153                         break;
 154         }
 155         /*
 156          * Check for trailing characters.
 157          */
 158         if (c != '\0' && (!isascii(c) || !isspace(c)))
 159                 goto ret_0;
 160         /*
 161          * Did we get a valid digit?
 162          */
 163         if (!digit)
 164                 goto ret_0;
 165
 166         /* Check whether the last part is in its limits depending on
 167            the number of parts in total.  */
 168         if (val > max[pp - res.bytes])
 169           goto ret_0;
 170
 171         if (addr != NULL)
 172                 addr->s_addr = res.word | htonl (val);
 173
 174         __set_errno (saved_errno);
 175         return (1);
 176
 177 ret_0:
 178         __set_errno (saved_errno);
 179         return (0);
 180 }
 181 weak_alias (__inet_aton, inet_aton)
 182 libc_hidden_def (__inet_aton)
 183 libc_hidden_weak (inet_aton)