set rx rate to unlimited for knet

Since KNET uses a different channel for packets than OpenFlow and is
much more efficient, higher packet rates than 1024 (the default) is
easily doable.

So set the rx rate to unlimited by default when using KNET, but leave it
at 1024 pps for TAP.

In case this causes issue, add a flag to set a custom limit.

Signed-off-by: Jonas Gorski <[email protected]>

pkg/systemd/sysconfig.template

@@ -20,6 +20,12 @@
 #
 # Vlan ID used for untagged traffic on unbridged ports (1-4095):
 # FLAGS_port_untagged_vid=1
+#
+# Set a Packets per Seconds rate limit for traffic to controller.
+#  -1 = auto (unlimited for KNET, 1024 for TAP)
+#   0 = force unlimited
+# Default is auto.
+# FLAGS_rx_rate_limit=-1
 
 ### glog logging configuration
 #

src/baseboxd.cc

@@ -25,6 +25,8 @@ DEFINE_bool(clear_switch_configuration, true,
             "Clear switch configuration on connect");
 DEFINE_int32(port_untagged_vid, 1,
              "VLAN ID used for untagged traffic on unbridged ports");
+DEFINE_int32(rx_rate_limit, -1,
+             "PPS limit for traffic to controller (-1 = auto, 0 = force unlimited)"
 
 static bool validate_port(const char *flagname, gflags::int32 value) {
   VLOG(3) << __FUNCTION__ << ": flagname=" << flagname << ", value=" << value;

src/of-dpa/controller.cc

@@ -22,6 +22,8 @@
 #include "utils/rofl-utils.h"
 
 DECLARE_bool(clear_switch_configuration);
+DECLARE_bool(use_knet);
+DECLARE_int32(rx_rate_limit);
 
 namespace basebox {
 
@@ -100,6 +102,20 @@ void controller::handle_dpt_open(rofl::crofdpt &dpt) {
     ofdpa->ofdpaStgReset();
   }
 
+  int rate = FLAGS_rx_rate_limit;
+  if (rate < 0) {
+    if (FLAGS_use_knet)
+      // Packets use a different channel, so set unlimited.
+      rate = 0;
+    else
+      // TAP packets use the same channel as control traffic, so set the
+      // default limit of 1024 pps (about ~11 Mbit/s) to ensure the OpenFlow
+      // connection is stable.
+      rate = 1024;
+  }
+
+  ofdpa->ofdpaRxRateSet(rate);
+
   dpt.send_features_request(rofl::cauxid(0), 1);
   dpt.send_desc_stats_request(rofl::cauxid(0), 0, 1);
 

src/of-dpa/ofdpa_client.cc

@@ -513,4 +513,22 @@ ofdpa_client::ofdpaTrunkPortPSCSet(uint32_t lag_id, uint8_t mode) {
   return response.status();
 }
 
+ofdpa::OfdpaStatus::OfdpaStatusCode
+ofdpa_client::ofdpaRxRateSet(int32_t pps) {
+  ::OfdpaStatus response;
+  ::ClientContext context;
+  ::Pps request;
+
+  context.set_wait_for_ready(true);
+
+  request.set_pps(pps);
+
+  ::Status rv = stub_->ofdpaRxRateSet(&context, request, &response);
+  if (not rv.ok()) {
+    return ofdpa::OfdpaStatus::OFDPA_E_RPC;
+  }
+
+  return response.status();
+}
+
 } // namespace basebox

src/of-dpa/ofdpa_client.h

@@ -80,6 +80,7 @@ class ofdpa_client {
 
   ofdpa::OfdpaStatus::OfdpaStatusCode ofdpaTrunkPortPSCSet(uint32_t lag_id,
                                                            uint8_t mode);
+  ofdpa::OfdpaStatus::OfdpaStatusCode ofdpaRxRateSet(int32_t pps);
 
 private:
   ofdpa::OfdpaStatus::OfdpaStatusCode