1 files changed, 103 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/ifreq.h b/sysdeps/unix/sysv/linux/ifreq.h
new file mode 100644
index 0000000000..8c9000551d
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/ifreq.h
@@ -0,0 +1,103 @@
+/* Copyright (C) 1999 Free Software Foundation, Inc.
+   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 Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <net/if.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include "kernel-features.h"
+
+/* Variable to signal whether SIOCGIFCONF is not available.  */
+#if __ASSUME_SIOCGIFNAME == 0
+static int old_siocgifconf;
+#else
+# define old_siocgifconf 0
+#endif
+
+
+static inline void
+__ifreq (struct ifreq **ifreqs, int *num_ifs)
+{
+  int fd = __opensock ();
+  struct ifconf ifc;
+  int rq_len;
+  int nifs;
+# define RQ_IFS	4
+
+  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.  */
+  do
+    {
+      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);
+	  
+	  __close (fd);
+
+	  *num_ifs = 0;
+	  *ifreqs = NULL;
+	  return;
+	}
+      rq_len *= 2;
+    }
+  while (ifc.ifc_len == rq_len && old_siocgifconf);
+
+  nifs = ifc.ifc_len / sizeof (struct ifreq);
+  __close (fd);
+
+  *num_ifs = nifs;
+  *ifreqs = realloc (ifc.ifc_buf, nifs * sizeof (struct ifreq));
+}
+
+static inline void
+__if_freereq (struct ifreq *ifreqs)
+{
+  free (ifreqs);
+}