1 files changed, 93 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/ifreq.c b/sysdeps/unix/sysv/linux/ifreq.c
new file mode 100644
index 0000000000..ad408df070
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/ifreq.c
@@ -0,0 +1,93 @@
+/* Copyright (C) 1999, 2002, 2003 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"
+
+
+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;
+      ifc.ifc_buf = realloc (ifc.ifc_buf, ifc.ifc_len);
+      if (ifc.ifc_buf == NULL || __ioctl (fd, SIOCGIFCONF, &ifc) < 0)
+	{
+	  if (ifc.ifc_buf)
+	    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));
+}