[DTS][PATCH V3 5/5] tests/vf_offload: Replace the tcpdump implementation to a packet reading implementation.

[Ke Xu <ke1.xu@intel.com>]

Packet reading implementation is more common to use when to verify the
 received packet count and payload size. The tcpdump method is not
 able to recognize some of the tunnel packets, leading to a wrong output
 failing the validation. Newly added tcpdump_analyse_sniff method is
 implemented by sniff packet reading and analysing and can replace
 the lagacy methods number_of_packets and number_of_bytes.

Signed-off-by: Ke Xu <ke1.xu@intel.com>
---
 tests/TestSuite_vf_offload.py | 77 +++++++++--------------------------
 1 file changed, 20 insertions(+), 57 deletions(-)

diff --git a/tests/TestSuite_vf_offload.py b/tests/TestSuite_vf_offload.py
index 7a66229a..7a55c791 100644
--- a/tests/TestSuite_vf_offload.py
+++ b/tests/TestSuite_vf_offload.py
@@ -635,43 +635,6 @@ class TestVfOffload(TestCase):
         rx_packet_size = [len(p[Raw].load) for p in pkts]
         return rx_packet_count, rx_packet_size
 
-    def tcpdump_command(self, command):
-        """
-        Send a tcpdump related command and return an integer from the output.
-        """
-
-        result = self.tester.send_expect(command, "#")
-        print(result)
-        return int(result.strip())
-
-    def number_of_packets(self, iface):
-        """
-        By reading the file generated by tcpdump it counts how many packets are
-        forwarded by the sample app and received in the self.tester. The sample app
-        will add a known MAC address for the test to look for.
-        """
-
-        command = (
-            "tcpdump -A -nn -e -v -r tcpdump_{iface}.pcap 2>/dev/null | "
-            + 'grep -c "seq"'
-        )
-        return self.tcpdump_command(command.format(**locals()))
-
-    def tcpdump_scanner(self, scanner):
-        """
-        Execute scanner to return results
-        """
-        scanner_result = self.tester.send_expect(scanner, "#")
-        finally_result = re.findall(r"length( \d+)", scanner_result)
-        return list(finally_result)
-
-    def number_of_bytes(self, iface):
-        """
-        Get the length of loading_sizes
-        """
-        scanner = 'tcpdump  -n -vv -r tcpdump_{iface}.pcap 2>/dev/null | grep "seq"  | grep "length"'
-        return self.tcpdump_scanner(scanner.format(**locals()))
-
     def test_tso(self):
         """
         TSO IPv4 TCP, IPv6 TCP testing.
@@ -769,27 +732,26 @@ class TestVfOffload(TestCase):
             out = self.vm0_testpmd.execute_cmd("show port stats all")
             print(out)
             self.tcpdump_stop_sniff()
-            rx_stats = self.number_of_packets(rx_interface)
-            tx_stats = self.number_of_packets(tx_interface)
-            tx_outlist = self.number_of_bytes(rx_interface)
-            tx_outlist.sort(reverse=True)
-            self.logger.info(tx_outlist)
+            rx_stats, payload_size_list = self.tcpdump_analyse_sniff(rx_interface)
+            tx_stats, _ = self.tcpdump_analyse_sniff(tx_interface)
+            payload_size_list.sort(reverse=True)
+            self.logger.info(payload_size_list)
             if loading_size <= 800:
                 self.verify(
-                    rx_stats == tx_stats and int(tx_outlist[0]) == loading_size,
+                    rx_stats == tx_stats and int(payload_size_list[0]) == loading_size,
                     "IPV4 RX or TX packet number not correct",
                 )
             else:
                 num = loading_size // 800
                 for i in range(num):
                     self.verify(
-                        int(tx_outlist[i]) == 800,
-                        "the packet segmentation incorrect, %s" % tx_outlist,
+                        int(payload_size_list[i]) == 800,
+                        "the packet segmentation incorrect, %s" % payload_size_list,
                     )
                 if loading_size % 800 != 0:
                     self.verify(
-                        int(tx_outlist[num]) == loading_size % 800,
-                        "the packet segmentation incorrect, %s" % tx_outlist,
+                        int(payload_size_list[num]) == loading_size % 800,
+                        "the packet segmentation incorrect, %s" % payload_size_list,
                     )
 
         for loading_size in self.loading_sizes:
@@ -804,27 +766,26 @@ class TestVfOffload(TestCase):
             out = self.vm0_testpmd.execute_cmd("show port stats all")
             print(out)
             self.tcpdump_stop_sniff()
-            rx_stats = self.number_of_packets(rx_interface)
-            tx_stats = self.number_of_packets(tx_interface)
-            tx_outlist = self.number_of_bytes(rx_interface)
-            tx_outlist.sort(reverse=True)
-            self.logger.info(tx_outlist)
+            rx_stats, payload_size_list = self.tcpdump_analyse_sniff(rx_interface)
+            tx_stats, _ = self.tcpdump_analyse_sniff(tx_interface)
+            payload_size_list.sort(reverse=True)
+            self.logger.info(payload_size_list)
             if loading_size <= 800:
                 self.verify(
-                    rx_stats == tx_stats and int(tx_outlist[0]) == loading_size,
+                    rx_stats == tx_stats and int(payload_size_list[0]) == loading_size,
                     "IPV6 RX or TX packet number not correct",
                 )
             else:
                 num = loading_size // 800
                 for i in range(num):
                     self.verify(
-                        int(tx_outlist[i]) == 800,
-                        "the packet segmentation incorrect, %s" % tx_outlist,
+                        int(payload_size_list[i]) == 800,
+                        "the packet segmentation incorrect, %s" % payload_size_list,
                     )
                 if loading_size % 800 != 0:
                     self.verify(
-                        int(tx_outlist[num]) == loading_size % 800,
-                        "the packet segmentation incorrect, %s" % tx_outlist,
+                        int(payload_size_list[num]) == loading_size % 800,
+                        "the packet segmentation incorrect, %s" % payload_size_list,
                     )
 
     @check_supported_nic(
@@ -923,6 +884,7 @@ class TestVfOffload(TestCase):
                 self.tcpdump_stop_sniff()
                 rx_stats, payload_size_list = self.tcpdump_analyse_sniff(rx_interface)
                 tx_stats, _ = self.tcpdump_analyse_sniff(tx_interface)
+                payload_size_list.sort(reverse=True)
                 self.logger.info(payload_size_list)
                 if loading_size <= 800:
                     self.verify(
@@ -966,6 +928,7 @@ class TestVfOffload(TestCase):
                 self.tcpdump_stop_sniff()
                 rx_stats, payload_size_list = self.tcpdump_analyse_sniff(rx_interface)
                 tx_stats, _ = self.tcpdump_analyse_sniff(tx_interface)
+                payload_size_list.sort(reverse=True)
                 self.logger.info(payload_size_list)
                 if loading_size <= 800:
                     self.verify(
-- 
2.25.1