Sample program using SO_COOKIE

Added a per socket traffic monitoring option to illustrate the usage
of new getsockopt SO_COOKIE. The program is based on the socket traffic
monitoring program using xt_eBPF and in the new option the data entry
can be directly accessed using socket cookie. The cookie retrieved
allow us to lookup an element in the eBPF for a specific socket.

Signed-off-by: Chenbo Feng <fengc@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/samples/bpf/run_cookie_uid_helper_example.sh b/samples/bpf/run_cookie_uid_helper_example.sh
old mode 100644
new mode 100755
index 40da8aa..f898cfa
--- a/samples/bpf/run_cookie_uid_helper_example.sh
+++ b/samples/bpf/run_cookie_uid_helper_example.sh
@@ -4,11 +4,11 @@
 mnt_dir=$(mktemp -d --tmp)
 
 on_exit() {
-	iptables -D INPUT -m bpf --object-pinned ${mnt_dir}/bpf_prog -j ACCEPT
+	iptables -D OUTPUT -m bpf --object-pinned ${mnt_dir}/bpf_prog -j ACCEPT
 	umount ${mnt_dir}
 	rm -r ${mnt_dir}
 }
 
 trap on_exit EXIT
 mount -t bpf bpf ${mnt_dir}
-./per_socket_stats_example ${mnt_dir}/bpf_prog
+./per_socket_stats_example ${mnt_dir}/bpf_prog $1