/* Legacy IPv4 text-to-address functions.

   Copyright (C) 2019 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

/*

 * Copyright (c) 1983, 1990, 1993

 *    The Regents of the University of California.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 4. Neither the name of the University nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 */

/*

 * Portions Copyright (c) 1993 by Digital Equipment Corporation.

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies, and that

 * the name of Digital Equipment Corporation not be used in advertising or

 * publicity pertaining to distribution of the document or software without

 * specific, written prior permission.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL

 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT

 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL

 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR

 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS

 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS

 * SOFTWARE.

 */

/*

 * Portions Copyright (c) 1996-1999 by Internet Software Consortium.

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS

 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE

 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL

 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR

 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS

 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS

 * SOFTWARE.

 */

#include <sys/types.h>

#include <sys/param.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <ctype.h>

#include <endian.h>

#include <stdint.h>

#include <stdlib.h>

#include <limits.h>

#include <errno.h>

/* Check whether "cp" is a valid ASCII representation of an IPv4

   Internet address and convert it to a binary address.  Returns 1 if

   the address is valid, 0 if not.  This replaces inet_addr, the

   return value from which cannot distinguish between failure and a

   local broadcast address.  Write a pointer to the first

   non-converted character to *endp.  */

static int

inet_aton_end (const char *cp, struct in_addr *addr, const char **endp)

{

  static const in_addr_t max[4] = { 0xffffffff, 0xffffff, 0xffff, 0xff };

  in_addr_t val;

  char c;

  union iaddr

  {

    uint8_t bytes[4];

    uint32_t word;

  } res;

  uint8_t *pp = res.bytes;

  int digit;

  int saved_errno = errno;

  __set_errno (0);

  res.word = 0;

  c = *cp;

  for (;;)

    {

      /* Collect number up to ``.''.  Values are specified as for C:

	 0x=hex, 0=octal, isdigit=decimal.  */

      if (!isdigit (c))

	goto ret_0;

      {

	char *endp;

	unsigned long ul = strtoul (cp, &endp, 0);

	if (ul == ULONG_MAX && errno == ERANGE)

	  goto ret_0;

	if (ul > 0xfffffffful)

	  goto ret_0;

	val = ul;

	digit = cp != endp;

	cp = endp;

      }

      c = *cp;

      if (c == '.')

	{

	  /* Internet format:

	     a.b.c.d

	     a.b.c	(with c treated as 16 bits)

	     a.b	(with b treated as 24 bits).  */

	  if (pp > res.bytes + 2 || val > 0xff)

	    goto ret_0;

	  *pp++ = val;

	  c = *++cp;

	}

      else

	break;

    }

  /* Check for trailing characters.  */

  if (c != '\0' && (!isascii (c) || !isspace (c)))

    goto ret_0;

  /*  Did we get a valid digit?  */

  if (!digit)

    goto ret_0;

  /* Check whether the last part is in its limits depending on the

     number of parts in total.  */

  if (val > max[pp - res.bytes])

    goto ret_0;

  if (addr != NULL)

    addr->s_addr = res.word | htonl (val);

  *endp = cp;

  __set_errno (saved_errno);

  return 1;

 ret_0:

  __set_errno (saved_errno);

  return 0;

}

int

__inet_aton_exact (const char *cp, struct in_addr *addr)

{

  struct in_addr val;

  const char *endp;

  /* Check that inet_aton_end parsed the entire string.  */

  if (inet_aton_end (cp, &val, &endp) != 0 && *endp == 0)

    {

      *addr = val;

      return 1;

    }

  else

    return 0;

}

libc_hidden_def (__inet_aton_exact)

/* inet_aton ignores trailing garbage.  */

int

__inet_aton_ignore_trailing (const char *cp, struct in_addr *addr)

{

  const char *endp;

  return  inet_aton_end (cp, addr, &endp);

}

weak_alias (__inet_aton_ignore_trailing, inet_aton)

/* ASCII IPv4 Internet address interpretation routine.  The value

   returned is in network order.  */

in_addr_t

__inet_addr (const char *cp)

{

  struct in_addr val;

  const char *endp;

  if (inet_aton_end (cp, &val, &endp))

    return val.s_addr;

  return INADDR_NONE;

}

weak_alias (__inet_addr, inet_addr)