1/* Get IPv4 source filter. Linux version.
2 Copyright (C) 2004-2023 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#include <errno.h>
20#include <stdlib.h>
21#include <scratch_buffer.h>
22#include <string.h>
23#include <stdint.h>
24#include <netinet/in.h>
25#include <sys/param.h>
26#include <sys/socket.h>
27
28
29int
30getipv4sourcefilter (int s, struct in_addr interface, struct in_addr group,
31 uint32_t *fmode, uint32_t *numsrc, struct in_addr *slist)
32{
33 /* We have to create an struct ip_msfilter object which we can pass
34 to the kernel. */
35 socklen_t needed = IP_MSFILTER_SIZE (*numsrc);
36
37 struct scratch_buffer buf;
38 scratch_buffer_init (&buf);
39 if (!scratch_buffer_set_array_size (&buf, 1, needed))
40 return -1;
41 struct ip_msfilter *imsf = buf.data;
42
43 imsf->imsf_multiaddr = group;
44 imsf->imsf_interface = interface;
45 imsf->imsf_numsrc = *numsrc;
46
47 int result = __getsockopt (s, SOL_IP, IP_MSFILTER, imsf, &needed);
48
49 /* If successful, copy the results to the places the caller wants
50 them in. */
51 if (result == 0)
52 {
53 *fmode = imsf->imsf_fmode;
54 memcpy (slist, imsf->imsf_slist,
55 MIN (*numsrc, imsf->imsf_numsrc) * sizeof (struct in_addr));
56 *numsrc = imsf->imsf_numsrc;
57 }
58
59 scratch_buffer_free (&buf);
60
61 return result;
62}
63