resolv/inet_addr.c

   1 /* Legacy IPv4 text-to-address functions.
   2    Copyright (C) 2019-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 /*
  20  * Copyright (c) 1983, 1990, 1993
  21  *    The Regents of the University of California.  All rights reserved.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the above copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 4. Neither the name of the University nor the names of its contributors
  32  *    may be used to endorse or promote products derived from this software
  33  *    without specific prior written permission.
  34  *
  35  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  36  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  37  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  38  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  39  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  40  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  41  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  42  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  43  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  44  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  45  * SUCH DAMAGE.
  46  */
  47
  48 /*
  49  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
  50  *
  51  * Permission to use, copy, modify, and distribute this software for any
  52  * purpose with or without fee is hereby granted, provided that the above
  53  * copyright notice and this permission notice appear in all copies, and that
  54  * the name of Digital Equipment Corporation not be used in advertising or
  55  * publicity pertaining to distribution of the document or software without
  56  * specific, written prior permission.
  57  *
  58  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
  59  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
  60  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
  61  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  62  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  63  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  64  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  65  * SOFTWARE.
  66  */
  67
  68 /*
  69  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
  70  *
  71  * Permission to use, copy, modify, and distribute this software for any
  72  * purpose with or without fee is hereby granted, provided that the above
  73  * copyright notice and this permission notice appear in all copies.
  74  *
  75  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
  76  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  77  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  78  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  79  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  80  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  81  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  82  * SOFTWARE.
  83  */
  84
  85 #include <sys/types.h>
  86 #include <sys/param.h>
  87
  88 #include <netinet/in.h>
  89 #include <arpa/inet.h>
  90
  91 #include <ctype.h>
  92
  93 #include <endian.h>
  94 #include <stdint.h>
  95 #include <stdlib.h>
  96 #include <limits.h>
  97 #include <errno.h>
  98
  99 /* Check whether "cp" is a valid ASCII representation of an IPv4
 100    Internet address and convert it to a binary address.  Returns 1 if
 101    the address is valid, 0 if not.  This replaces inet_addr, the
 102    return value from which cannot distinguish between failure and a
 103    local broadcast address.  Write a pointer to the first
 104    non-converted character to *endp.  */
 105 static int
 106 inet_aton_end (const char *cp, struct in_addr *addr, const char **endp)
 107 {
 108   static const in_addr_t max[4] = { 0xffffffff, 0xffffff, 0xffff, 0xff };
 109   in_addr_t val;
 110   char c;
 111   union iaddr
 112   {
 113     uint8_t bytes[4];
 114     uint32_t word;
 115   } res;
 116   uint8_t *pp = res.bytes;
 117   int digit;
 118
 119   int saved_errno = errno;
 120   __set_errno (0);
 121
 122   res.word = 0;
 123
 124   c = *cp;
 125   for (;;)
 126     {
 127       /* Collect number up to ``.''.  Values are specified as for C:
 128          0x=hex, 0=octal, isdigit=decimal.  */
 129       if (!isdigit (c))
 130         goto ret_0;
 131       {
 132         char *endp;
 133         unsigned long ul = strtoul (cp, &endp, 0);
 134         if (ul == ULONG_MAX && errno == ERANGE)
 135           goto ret_0;
 136         if (ul > 0xfffffffful)
 137           goto ret_0;
 138         val = ul;
 139         digit = cp != endp;
 140         cp = endp;
 141       }
 142       c = *cp;
 143       if (c == '.')
 144         {
 145           /* Internet format:
 146              a.b.c.d
 147              a.b.c      (with c treated as 16 bits)
 148              a.b        (with b treated as 24 bits).  */
 149           if (pp > res.bytes + 2 || val > 0xff)
 150             goto ret_0;
 151           *pp++ = val;
 152           c = *++cp;
 153         }
 154       else
 155         break;
 156     }
 157   /* Check for trailing characters.  */
 158   if (c != '\0' && (!isascii (c) || !isspace (c)))
 159     goto ret_0;
 160   /*  Did we get a valid digit?  */
 161   if (!digit)
 162     goto ret_0;
 163
 164   /* Check whether the last part is in its limits depending on the
 165      number of parts in total.  */
 166   if (val > max[pp - res.bytes])
 167     goto ret_0;
 168
 169   if (addr != NULL)
 170     addr->s_addr = res.word | htonl (val);
 171   *endp = cp;
 172
 173   __set_errno (saved_errno);
 174   return 1;
 175
 176  ret_0:
 177   __set_errno (saved_errno);
 178   return 0;
 179 }
 180
 181 int
 182 __inet_aton_exact (const char *cp, struct in_addr *addr)
 183 {
 184   struct in_addr val;
 185   const char *endp;
 186   /* Check that inet_aton_end parsed the entire string.  */
 187   if (inet_aton_end (cp, &val, &endp) != 0 && *endp == 0)
 188     {
 189       *addr = val;
 190       return 1;
 191     }
 192   else
 193     return 0;
 194 }
 195 libc_hidden_def (__inet_aton_exact)
 196
 197 /* inet_aton ignores trailing garbage.  */
 198 int
 199 __inet_aton_ignore_trailing (const char *cp, struct in_addr *addr)
 200 {
 201   const char *endp;
 202   return  inet_aton_end (cp, addr, &endp);
 203 }
 204 weak_alias (__inet_aton_ignore_trailing, inet_aton)
 205
 206 /* ASCII IPv4 Internet address interpretation routine.  The value
 207    returned is in network order.  */
 208 in_addr_t
 209 __inet_addr (const char *cp)
 210 {
 211   struct in_addr val;
 212   const char *endp;
 213   if (inet_aton_end (cp, &val, &endp))
 214     return val.s_addr;
 215   return INADDR_NONE;
 216 }
 217 weak_alias (__inet_addr, inet_addr)