1 /* Copyright (C) 1999-2024 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
22 __ifreq (struct ifreq
**ifreqs
, int *num_ifs
, int sockfd
)
41 /* We may be able to get the needed buffer size directly, rather than
45 if (__ioctl (fd
, SIOCGIFCONF
, &ifc
) < 0 || ifc
.ifc_len
== 0)
46 rq_len
= RQ_IFS
* sizeof (struct ifreq
);
50 /* Read all the interfaces out of the kernel. */
52 void *newp
= realloc (ifc
.ifc_buf
, ifc
.ifc_len
);
54 || (ifc
.ifc_buf
= newp
, __ioctl (fd
, SIOCGIFCONF
, &ifc
)) < 0)
66 nifs
= ifc
.ifc_len
/ sizeof (struct ifreq
);
72 *ifreqs
= realloc (ifc
.ifc_buf
, nifs
* sizeof (struct ifreq
));