mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-02 17:50:20 +00:00
f3285f86f5
2004-07-26 Ulrich Drepper <drepper@redhat.com> * sysdeps/unix/sysv/linux/ifreq.c (__ifreq): Assign pointer for new buffer at the right time. Reported by Jakub Bogusz <qboosh@pld-linux.org>.
101 lines
2.4 KiB
C
101 lines
2.4 KiB
C
/* Copyright (C) 1999, 2002, 2003, 2004 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Andreas Jaeger <aj@suse.de>.
|
|
|
|
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 "ifreq.h"
|
|
|
|
/* Variable to signal whether SIOCGIFCONF is not available. */
|
|
#if __ASSUME_SIOCGIFNAME == 0 || 1
|
|
static int old_siocgifconf;
|
|
#else
|
|
# define old_siocgifconf 0
|
|
#endif
|
|
|
|
|
|
void
|
|
__ifreq (struct ifreq **ifreqs, int *num_ifs, int sockfd)
|
|
{
|
|
int fd = sockfd;
|
|
struct ifconf ifc;
|
|
int rq_len;
|
|
int nifs;
|
|
# define RQ_IFS 4
|
|
|
|
if (fd < 0)
|
|
fd = __opensock ();
|
|
if (fd < 0)
|
|
{
|
|
*num_ifs = 0;
|
|
*ifreqs = NULL;
|
|
return;
|
|
}
|
|
|
|
ifc.ifc_buf = NULL;
|
|
|
|
/* We may be able to get the needed buffer size directly, rather than
|
|
guessing. */
|
|
if (! old_siocgifconf)
|
|
{
|
|
ifc.ifc_buf = NULL;
|
|
ifc.ifc_len = 0;
|
|
if (__ioctl (fd, SIOCGIFCONF, &ifc) < 0 || ifc.ifc_len == 0)
|
|
{
|
|
# if __ASSUME_SIOCGIFNAME == 0
|
|
old_siocgifconf = 1;
|
|
# endif
|
|
rq_len = RQ_IFS * sizeof (struct ifreq);
|
|
}
|
|
else
|
|
rq_len = ifc.ifc_len;
|
|
}
|
|
else
|
|
rq_len = RQ_IFS * sizeof (struct ifreq);
|
|
|
|
/* Read all the interfaces out of the kernel. */
|
|
while (1)
|
|
{
|
|
ifc.ifc_len = rq_len;
|
|
void *newp = realloc (ifc.ifc_buf, ifc.ifc_len);
|
|
if (newp == NULL
|
|
|| (ifc.ifc_buf = newp, __ioctl (fd, SIOCGIFCONF, &ifc)) < 0)
|
|
{
|
|
free (ifc.ifc_buf);
|
|
|
|
if (fd != sockfd)
|
|
__close (fd);
|
|
|
|
*num_ifs = 0;
|
|
*ifreqs = NULL;
|
|
return;
|
|
}
|
|
|
|
if (!old_siocgifconf || ifc.ifc_len < rq_len)
|
|
break;
|
|
|
|
rq_len *= 2;
|
|
}
|
|
|
|
nifs = ifc.ifc_len / sizeof (struct ifreq);
|
|
|
|
if (fd != sockfd)
|
|
__close (fd);
|
|
|
|
*num_ifs = nifs;
|
|
*ifreqs = realloc (ifc.ifc_buf, nifs * sizeof (struct ifreq));
|
|
}
|