sign: Fix Tx stream stats counted as Rx on some platforms

On platforms that don't support filtering IN/OUT using
pcap_setdirection() - e.g. Windows, adjust Rx stats appropriately

server/pcapport.cpp

@@ -161,6 +161,14 @@ bool PcapPort::startStreamStatsTracking()
         goto _tx_fail;
     if (!rxStatsPoller_->start())
         goto _rx_fail;
+    /*
+     * If RxPoller receives both IN and OUT packets, packets Tx on this
+     * port will also be received by it and we consider it to be a Rx (IN)
+     * packet incorrectly - so adjust Rx stats for this case
+     * XXX - ideally, RxPoller should do this adjustment, but given our
+     * design, it is easier to implement in transmitter
+     */
+    transmitter_->adjustRxStreamStats(!rxStatsPoller_->isDirectional());
     return true;
 
 _rx_fail:

server/pcaprxstats.cpp

@@ -30,6 +30,7 @@ PcapRxStats::PcapRxStats(const char *device, StreamStats &portStreamStats)
     device_ = QString::fromAscii(device);
     stop_ = false;
     state_ = kNotStarted;
+    isDirectional_ = true;
 
     handle_ = NULL;
 }
@@ -70,10 +71,13 @@ void PcapRxStats::run()
     // NOTE: WinPcap 4.1.1 and above exports a dummy API that returns -1
     // but since we would like to work with previous versions of WinPcap
     // also, we assume the API does not exist
+    isDirectional_ = false;
 #else
-    if (pcap_setdirection(handle_, PCAP_D_IN) < 0)
+    if (pcap_setdirection(handle_, PCAP_D_IN) < 0) {
         qDebug("RxStats: Error setting IN direction %s: %s\n",
                 qPrintable(device_), pcap_geterr(handle_));
+        isDirectional_ = false;
+    }
 #endif
 
     if (pcap_compile(handle_, &bpf, qPrintable(capture_filter),
@@ -165,3 +169,8 @@ bool PcapRxStats::isRunning()
 {
     return (state_ == kRunning);
 }
+
+bool PcapRxStats::isDirectional()
+{
+    return isDirectional_;
+}

server/pcaprxstats.h

@@ -34,6 +34,7 @@ public:
     bool start();
     bool stop();
     bool isRunning();
+    bool isDirectional();
 
 private:
     enum State {
@@ -47,6 +48,7 @@ private:
     volatile bool stop_;
     pcap_t *handle_;
     volatile State state_;
+    bool isDirectional_;
 };
 
 #endif

server/pcaptransmitter.cpp

@@ -24,6 +24,7 @@ PcapTransmitter::PcapTransmitter(
         StreamStats &portStreamStats)
     : streamStats_(portStreamStats), txThread_(device)
 {
+    adjustRxStreamStats_ = false;
     memset(&stats_, 0, sizeof(stats_));
     txStats_.setTxThreadStats(&stats_);
     txStats_.start(); // TODO: alongwith user transmit start
@@ -43,6 +44,11 @@ bool PcapTransmitter::setRateAccuracy(
     return txThread_.setRateAccuracy(accuracy);
 }
 
+void PcapTransmitter::adjustRxStreamStats(bool enable)
+{
+    adjustRxStreamStats_ = enable;
+}
+
 bool PcapTransmitter::setStreamStatsTracking(bool enable)
 {
     return txThread_.setStreamStatsTracking(enable);
@@ -115,6 +121,10 @@ void PcapTransmitter::updateTxThreadStreamStats()
 
         streamStats_[guid].tx_pkts += sst.tx_pkts;
         streamStats_[guid].tx_bytes += sst.tx_bytes;
+        if (adjustRxStreamStats_) {
+            streamStats_[guid].rx_pkts -= sst.tx_pkts;
+            streamStats_[guid].rx_bytes -= sst.tx_bytes;
+        }
     }
     txThread->clearStreamStats();
 }

server/pcaptransmitter.h

@@ -34,6 +34,7 @@ public:
 
     bool setRateAccuracy(AbstractPort::Accuracy accuracy);
     bool setStreamStatsTracking(bool enable);
+    void adjustRxStreamStats(bool enable);
 
     void clearPacketList();
     void loopNextPacketSet(qint64 size, qint64 repeats,
@@ -55,6 +56,7 @@ private:
     PcapTxThread txThread_;
     PcapTxStats txStats_;
     StatsTuple stats_;
+    bool adjustRxStreamStats_;
 };
 
 #endif

test/streamstatstest.py

@@ -592,10 +592,8 @@ def test_unidir(drone, ports, dut, dut_ports, dut_ip, emul_ports, dgid_list,
             # for unidir verify rx on tx port is 0 and vice versa
             # FIXME: failing currently because tx pkts on tx port seem to be
             # captured by rxStatsPoller_ on tx port
-            """
             assert ssd.port[ports.x_num].sguid[guid].rx_pkts == 0
             assert ssd.port[ports.x_num].sguid[guid].rx_bytes == 0
-            """
             assert ssd.port[ports.y_num].sguid[guid].tx_pkts == 0
             assert ssd.port[ports.y_num].sguid[guid].tx_bytes == 0