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.
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.
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.
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/>. */
24 #include <netinet/in.h>
25 #include <sys/param.h>
26 #include <sys/socket.h>
30 getipv4sourcefilter (int s
, struct in_addr interface
, struct in_addr group
,
31 uint32_t *fmode
, uint32_t *numsrc
, struct in_addr
*slist
)
33 /* We have to create an struct ip_msfilter object which we can pass
35 socklen_t needed
= IP_MSFILTER_SIZE (*numsrc
);
36 int use_alloca
= __libc_use_alloca (needed
);
38 struct ip_msfilter
*imsf
;
40 imsf
= (struct ip_msfilter
*) alloca (needed
);
43 imsf
= (struct ip_msfilter
*) malloc (needed
);
48 imsf
->imsf_multiaddr
= group
;
49 imsf
->imsf_interface
= interface
;
50 imsf
->imsf_numsrc
= *numsrc
;
52 int result
= __getsockopt (s
, SOL_IP
, IP_MSFILTER
, imsf
, &needed
);
54 /* If successful, copy the results to the places the caller wants
58 *fmode
= imsf
->imsf_fmode
;
59 memcpy (slist
, imsf
->imsf_slist
,
60 MIN (*numsrc
, imsf
->imsf_numsrc
) * sizeof (struct in_addr
));
61 *numsrc
= imsf
->imsf_numsrc
;
66 int save_errno
= errno
;
68 __set_errno (save_errno
);