From 20991b937bb239473ca0e8f9a28b04d65a2b4bcb Mon Sep 17 00:00:00 2001
From: Matthias Bolte <matthias.bolte@googlemail.com>
Date: Thu, 23 Jun 2011 11:51:00 -0400
Subject: [PATCH] configure: Make libnl optional unless macvtap is required

If macvtap is required then libnl has to be available, otherwise
libnl is optional.
---
 configure.ac | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/configure.ac b/configure.ac
index f816696fad..8b9e604689 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2371,13 +2371,19 @@ dnl netlink library
 
 LIBNL_CFLAGS=""
 LIBNL_LIBS=""
+have_libnl=no
 
-if test "$with_macvtap" = "yes"; then
+if test "$with_linux" = "yes"; then
     PKG_CHECK_MODULES([LIBNL], [libnl-1 >= $LIBNL_REQUIRED], [
+        have_libnl=yes
+        AC_DEFINE_UNQUOTED([HAVE_LIBNL], 1, [whether the netlink library is available])
     ], [
-        AC_MSG_ERROR([libnl-devel >= $LIBNL_REQUIRED is required for macvtap support])
+        if test "$with_macvtap" = "yes"; then
+            AC_MSG_ERROR([libnl-devel >= $LIBNL_REQUIRED is required for macvtap support])
+        fi
     ])
 fi
+AM_CONDITIONAL([HAVE_LIBNL], [test "$have_libnl" = "yes"])
 
 AC_SUBST([LIBNL_CFLAGS])
 AC_SUBST([LIBNL_LIBS])
@@ -2574,7 +2580,7 @@ AC_MSG_NOTICE([    pcap: $LIBPCAP_CFLAGS $LIBPCAP_LIBS])
 else
 AC_MSG_NOTICE([    pcap: no])
 fi
-if test "$with_macvtap" = "yes" ; then
+if test "$have_libnl" = "yes" ; then
 AC_MSG_NOTICE([      nl: $LIBNL_CFLAGS $LIBNL_LIBS])
 else
 AC_MSG_NOTICE([      nl: no])