/* Set IPv4 source filter.  Linux version.

   Copyright (C) 2004-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Ulrich Drepper <drepper@redhat.com>, 2004.

   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/>.  */

#include <alloca.h>

#include <errno.h>

#include <stdlib.h>

#include <string.h>

#include <stdint.h>

#include <netinet/in.h>

#include <sys/socket.h>

int

setipv4sourcefilter (int s, struct in_addr interface, struct in_addr group,

		     uint32_t fmode, uint32_t numsrc,

		     const struct in_addr *slist)

{

  /* We have to create an struct ip_msfilter object which we can pass

     to the kernel.  */

  size_t needed = IP_MSFILTER_SIZE (numsrc);

  int use_alloca = __libc_use_alloca (needed);

  struct ip_msfilter *imsf;

  if (use_alloca)

    imsf = (struct ip_msfilter *) alloca (needed);

  else

    {

      imsf = (struct ip_msfilter *) malloc (needed);

      if (imsf == NULL)

	return -1;

    }

  imsf->imsf_multiaddr = group;

  imsf->imsf_interface = interface;

  imsf->imsf_fmode = fmode;

  imsf->imsf_numsrc = numsrc;

  memcpy (imsf->imsf_slist, slist, numsrc * sizeof (struct in_addr));

  int result = __setsockopt (s, SOL_IP, IP_MSFILTER, imsf, needed);

  if (! use_alloca)

    {

      int save_errno = errno;

      free (imsf);

      __set_errno (save_errno);

    }

  return result;

}