flow_control: implement pass / drop filtering policies

This change introduces a set of three modes for flow control
filters, one of which is default behavor and two extra modes
else described below:

  - FILTER_POLICY_PASS_ALL
  - FILTER_POLICY_DROP_ALL

Both modes are opposite, and make a filter either unconditionally
pass or drop all the data one gets to the input. They would be
usable for some external usage.

1 files changed, 5 insertions, 0 deletions

diff --git a/lib/flow_control/burst_timeslot_filter_impl.h b/lib/flow_control/burst_timeslot_filter_impl.h
index 130047e..fa54ef4 100644
--- a/lib/flow_control/burst_timeslot_filter_impl.h
+++ b/lib/flow_control/burst_timeslot_filter_impl.h
@@ -31,6 +31,7 @@ namespace gr {
     class burst_timeslot_filter_impl : public burst_timeslot_filter
     {
      private:
+      filter_policy d_filter_policy;
       unsigned int d_timeslot;
      public:
       burst_timeslot_filter_impl(unsigned int timeslot);
@@ -40,6 +41,10 @@ namespace gr {
       /* External API */
       unsigned int get_tn(void);
       unsigned int set_tn(unsigned int tn);
+
+      /* Filtering policy */
+      filter_policy get_policy(void);
+      filter_policy set_policy(filter_policy policy);
     };
 
   } // namespace gsm