[RFC PATCH v1 2/3] dts: add port stats checks test suite

[jspewock@iol.unh.edu]

From: Jeremy Spewock <jspewock@iol.unh.edu>

This patch adds a new test suite to DTS that validates the accuracy of
the port statistics using testpmd. The functionality is tested by
sending a packet of a fixed side to the SUT and verifying that the
statistic for packets received, received bytes, packets sent, and sent
bytes all update accordingly.

Depends-on: patch-142762 ("dts: add text parser for testpmd verbose
 output")

Signed-off-by: Jeremy Spewock <jspewock@iol.unh.edu>
---
 dts/tests/TestSuite_port_stats_checks.py | 156 +++++++++++++++++++++++
 1 file changed, 156 insertions(+)
 create mode 100644 dts/tests/TestSuite_port_stats_checks.py

diff --git a/dts/tests/TestSuite_port_stats_checks.py b/dts/tests/TestSuite_port_stats_checks.py
new file mode 100644
index 0000000000..71e1c7906f
--- /dev/null
+++ b/dts/tests/TestSuite_port_stats_checks.py
@@ -0,0 +1,156 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2024 University of New Hampshire
+
+"""Port Statistics testing suite.
+
+This test suite tests the functionality of querying the statistics of a port and verifies that the
+values provided in the statistics accurately reflect the traffic that has been handled on the port.
+This is shown by sending a packet of a fixed size to the SUT and verifying that the number of RX
+packets has increased by 1, the number of RX bytes has increased by the specified size, the number
+of TX packets has also increased by 1 (since we expect the packet to be forwarded), and the number
+of TX bytes has also increased by the same fixed amount.
+"""
+
+from typing import ClassVar, Tuple
+
+from scapy.layers.inet import IP  # type: ignore[import-untyped]
+from scapy.layers.l2 import Ether  # type: ignore[import-untyped]
+from scapy.packet import Packet, Raw  # type: ignore[import-untyped]
+
+from framework.params.testpmd import SimpleForwardingModes
+from framework.remote_session.testpmd_shell import TestPmdShell, TestPmdVerboseOutput
+from framework.test_suite import TestSuite
+
+
+class TestPortStatsChecks(TestSuite):
+    """DPDK Port statistics testing suite.
+
+    Support for port statistics is tested by sending a packet of a fixed size denoted by
+    `total_packet_len` and verifying the that TX/RX packets of the TX/RX ports updated by exactly
+    1 and the TX/RX bytes of the TX/RX ports updated by exactly `total_packet_len`. This is done by
+    finding the total amount of packets that were sent/received which did not originate from this
+    test suite and taking the sum of the lengths of each of these "noise" packets and subtracting
+    it from the total values in the port statistics so that all that is left are relevant values.
+    """
+
+    #: Port where traffic will be received on the SUT.
+    recv_port: ClassVar[int] = 0
+    #: Port where traffic will be sent from on the SUT.
+    send_port: ClassVar[int] = 1
+
+    #:
+    ip_header_len: ClassVar[int] = 20
+    #:
+    ether_header_len: ClassVar[int] = 14
+
+    #: Length of the packet being sent including the IP and frame headers.
+    total_packet_len: ClassVar[int] = 100
+    #: Packet to send during testing.
+    send_pkt: ClassVar[Packet] = (
+        Ether() / IP() / Raw("X" * (total_packet_len - ip_header_len - ether_header_len))
+    )
+
+    def extract_noise_information(
+        self, verbose_out: list[TestPmdVerboseOutput]
+    ) -> Tuple[int, int, int, int]:
+        """Extract information about packets that were not sent by the framework in `verbose_out`.
+
+        Extract the number of sent/received packets that did not originate from this test suite as
+        well as the sum of the lengths of said "noise" packets. Note that received packets are only
+        examined on the port with the ID `self.recv_port` since these are the receive stats that
+        will be analyzed in this suite. Sent packets are also only examined on the port with the ID
+        `self.send_port`.
+
+        Packets are considered to be "noise" when they don't match the expected structure of the
+        packets that are being sent by this test suite. Specifically, the source and destination
+        mac addresses as well as the software packet type are checked on packets received by
+        testpmd to ensure they match the proper addresses of the TG and SUT nodes. Packets that are
+        sent by testpmd however only check the source mac address and the software packet type.
+        This is because MAC forwarding mode adjusts both addresses, but only the source will belong
+        to the TG or SUT node.
+
+        Args:
+            verbose_out: Parsed testpmd verbose output to collect the noise information from.
+
+        Returns:
+            A tuple containing the total size of received noise in bytes, the number of received
+            noise packets, size of all noise packets sent by testpmd in bytes, and the number of
+            noise packets sent by testpmd.
+        """
+        recv_noise_bytes = 0
+        recv_noise_packets = 0
+        sent_noise_bytes = 0
+        num_sent_packets = 0
+        for verbose_block in verbose_out:
+            for p in verbose_block.packets:
+                if verbose_block.was_received and verbose_block.port_id == self.recv_port:
+                    if (
+                        p.src_mac.lower() != self._tg_port_egress.mac_address.lower()
+                        or p.dst_mac.lower() != self._sut_port_ingress.mac_address.lower()
+                        or "L2_ETHER L3_IPV4" != p.sw_ptype.strip()
+                    ):
+                        recv_noise_bytes += p.length
+                        recv_noise_packets += 1
+                elif not verbose_block.was_received and verbose_block.port_id == self.send_port:
+                    if (
+                        p.src_mac.lower() != self._sut_port_egress.mac_address.lower()
+                        or "L2_ETHER L3_IPV4" != p.sw_ptype.strip()
+                    ):
+                        sent_noise_bytes += p.length
+                        num_sent_packets += 1
+
+        return recv_noise_bytes, recv_noise_packets, sent_noise_bytes, num_sent_packets
+
+    def test_stats_updates(self) -> None:
+        """Send a packet with a fixed length and verify port stats updated properly.
+
+        Send a packet with a total length of `self.total_packet_len` and verify that the rx port
+        only received one packet and the number of rx_bytes increased by exactly
+        `self.total_packet_len`. Also verify that the tx port only sent one packet and that the
+        tx_bytes of the port increase by exactly `self.total_packet_len`.
+
+        Noise on the wire is ignored by extracting the total number of noise packets and the sum of
+        the lengths of those packets and subtracting them from the totals that are provided by the
+        testpmd command `show port info all`.
+
+        Test:
+            Start testpmd in MAC forwarding mode and set verbose mode to 3 (RX and TX).
+            Start packet forwarding and then clear all port statistics.
+            Send a packet, then stop packet forwarding and collect the port stats.
+            Parse verbose info from stopping packet forwarding and verify values in port stats.
+        """
+        with TestPmdShell(self.sut_node, forward_mode=SimpleForwardingModes.mac) as testpmd:
+            testpmd.set_verbose(3)
+            testpmd.start()
+            testpmd.clear_port_stats_all()
+            self.send_packet_and_capture(self.send_pkt)
+            forwarding_output = testpmd.stop()
+            port_stats_all = testpmd.show_port_stats_all()
+            verbose_information = TestPmdShell.extract_verbose_output(forwarding_output)
+
+        # Gather information from irrelevant packets sent/ received on the same port.
+        rx_irr_bytes, rx_irr_pakts, tx_irr_bytes, tx_irr_pakts = self.extract_noise_information(
+            verbose_information
+        )
+        recv_relevant_packets = port_stats_all[self.recv_port].rx_packets - rx_irr_pakts
+        sent_relevant_packets = port_stats_all[self.send_port].tx_packets - tx_irr_pakts
+
+        self.verify(
+            recv_relevant_packets == 1,
+            f"Port {self.recv_port} received {recv_relevant_packets} packets but expected to only "
+            "receive 1.",
+        )
+        self.verify(
+            port_stats_all[self.recv_port].rx_bytes - rx_irr_bytes == self.total_packet_len,
+            f"Number of bytes received by port {self.recv_port} did not match the amount sent.",
+        )
+        self.verify(
+            sent_relevant_packets == 1,
+            f"Number was packets sent by port {self.send_port} was not equal to the number "
+            f"received by port {self.recv_port}.",
+        )
+        self.verify(
+            port_stats_all[self.send_port].tx_bytes - tx_irr_bytes == self.total_packet_len,
+            f"Number of bytes sent by port {self.send_port} did not match the number of bytes "
+            f"received by port {self.recv_port}.",
+        )
-- 
2.45.2