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/* Get IPv4 source filter. Linux version.
Copyright (C) 2004-2024 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
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <stdlib.h>
#include <scratch_buffer.h>
#include <string.h>
#include <stdint.h>
#include <netinet/in.h>
#include <sys/param.h>
#include <sys/socket.h>
int
getipv4sourcefilter (int s, struct in_addr interface, struct in_addr group,
uint32_t *fmode, uint32_t *numsrc, struct in_addr *slist)
{
/* We have to create an struct ip_msfilter object which we can pass
to the kernel. */
socklen_t needed = IP_MSFILTER_SIZE (*numsrc);
struct scratch_buffer buf;
scratch_buffer_init (&buf);
if (!scratch_buffer_set_array_size (&buf, 1, needed))
return -1;
struct ip_msfilter *imsf = buf.data;
imsf->imsf_multiaddr = group;
imsf->imsf_interface = interface;
imsf->imsf_numsrc = *numsrc;
int result = __getsockopt (s, SOL_IP, IP_MSFILTER, imsf, &needed);
/* If successful, copy the results to the places the caller wants
them in. */
if (result == 0)
{
*fmode = imsf->imsf_fmode;
memcpy (slist, imsf->imsf_slist,
MIN (*numsrc, imsf->imsf_numsrc) * sizeof (struct in_addr));
*numsrc = imsf->imsf_numsrc;
}
scratch_buffer_free (&buf);
return result;
}
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