ip netns: Fix rtnl error while print netns list

Observed on the Linux 3.18:

    # ip netns
    RTNETLINK answers: Operation not supported
    net0

CC: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Fixes: d182ee1307c7 ("ipnetns: allow to get and set netns ids")
Signed-off-by: Vadim Kochan <vadim4j@gmail.com>

1 files changed, 20 insertions, 1 deletions

diff --git a/configure b/configure
index c3dacdba..631938e9 100755
--- a/configure
+++ b/configure
@@ -201,7 +201,7 @@ check_setns()
 {
     cat >$TMPDIR/setnstest.c <<EOF
 #include <sched.h>
-int main(int argc, char **argv) 
+int main(int argc, char **argv)
 {
 	(void)setns(0,0);
 	return 0;
@@ -218,6 +218,23 @@ EOF
     rm -f $TMPDIR/setnstest.c $TMPDIR/setnstest
 }
 
+check_netnsid()
+{
+    cat >$TMPDIR/netnsid.c <<EOF
+#include <linux/rtnetlink.h>
+int test_def = RTM_GETNSID;
+EOF
+    $CC -c $TMPDIR/netnsid.c >/dev/null 2>&1
+    if [ $? -eq 0 ]
+    then
+	echo "IP_CONFIG_NETNSID:=y" >> Config
+	echo "yes"
+    else
+	echo "no"
+    fi
+    rm -f $TMPDIR/netnsid.c $TMPDIR/netnsid.o
+}
+
 check_ipset()
 {
     cat >$TMPDIR/ipsettest.c <<EOF
@@ -283,6 +300,8 @@ check_ipt_lib_dir
 
 echo -n "libc has setns: "
 check_setns
+echo -n "netns has peer id suport: "
+check_netnsid
 
 echo -n "SELinux support: "
 check_selinux