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/* Get source filter. Linux version.
Copyright (C) 2004 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <alloca.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <netinet/in.h>
#include <sys/socket.h>
int
getsourcefilter (int s, uint32_t interface, struct sockaddr *group,
socklen_t grouplen, uint32_t *fmode, uint32_t *numsrc,
struct sockaddr_storage *slist)
{
/* We have to create an struct ip_msfilter object which we can pass
to the kernel. */
socklen_t needed = GROUP_FILTER_SIZE (*numsrc);
int use_malloc = __libc_use_alloca (needed);
struct group_filter *gf;
if (use_malloc)
{
gf = (struct group_filter *) malloc (needed);
if (gf == NULL)
return -1;
}
else
gf = (struct group_filter *) alloca (needed);
gf->gf_interface = interface;
memcpy (&gf->gf_group, group, grouplen);
int result = __getsockopt (s, SOL_IP, MCAST_MSFILTER, gf, &needed);
/* If successful, copy the results to the places the caller wants
them in. */
if (result == 0)
{
*fmode = gf->gf_fmode;
*numsrc = gf->gf_numsrc;
memcpy (slist, gf->gf_slist,
gf->gf_numsrc * sizeof (struct sockaddr_storage));
}
if (use_malloc)
{
int save_errno = errno;
free (gf);
__set_errno (save_errno);
}
return result;
}
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