[PATCH v4 7/7] dts: add scatter test suite

[jspewock@iol.unh.edu]

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

This test suite provides testing the support of scattered packets by
Poll Mode Drivers using testpmd. It incorporates 5 different test cases
which test the sending and receiving of packets with lengths that are
less than the mbuf data buffer size, the same as the mbuf data buffer
size, and the mbuf data buffer size plus 1, 4, and 5. The goal of this
test suite is to align with the existing dts test plan for scattered
packets within DTS.

Signed-off-by: Jeremy Spewock <jspewock@iol.unh.edu>
---
 dts/tests/TestSuite_pmd_buffer_scatter.py | 105 ++++++++++++++++++++++
 1 file changed, 105 insertions(+)
 create mode 100644 dts/tests/TestSuite_pmd_buffer_scatter.py

diff --git a/dts/tests/TestSuite_pmd_buffer_scatter.py b/dts/tests/TestSuite_pmd_buffer_scatter.py
new file mode 100644
index 0000000000..8e2a32a1aa
--- /dev/null
+++ b/dts/tests/TestSuite_pmd_buffer_scatter.py
@@ -0,0 +1,105 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2023 University of New Hampshire
+
+"""Multi-segment packet scattering testing suite.
+
+Configure the Rx queues to have mbuf data buffers whose sizes are smaller than the maximum packet
+size (currently set to 2048 to fit a full 1512-byte ethernet frame) and send a total of 5 packets
+with lengths less than, equal to, and greater than the mbuf size (CRC included).
+"""
+import struct
+
+from scapy.layers.inet import IP  # type: ignore[import]
+from scapy.layers.l2 import Ether  # type: ignore[import]
+from scapy.packet import Raw  # type: ignore[import]
+from scapy.utils import hexstr  # type: ignore[import]
+
+from framework.remote_session.remote.testpmd_shell import (
+    TestPmdForwardingModes,
+    TestPmdShell,
+)
+from framework.test_suite import TestSuite
+
+
+class PmdBufferScatter(TestSuite):
+    """DPDK packet scattering test suite.
+
+    Attributes:
+        mbsize: The size to se the mbuf to be.
+    """
+
+    mbsize: int
+
+    def set_up_suite(self) -> None:
+        self.verify(
+            len(self._port_links) > 1,
+            "Must have at least two port links to run scatter",
+        )
+
+        self.tg_node.main_session.configure_port_mtu(9000, self._tg_port_egress)
+        self.tg_node.main_session.configure_port_mtu(9000, self._tg_port_ingress)
+
+    def scatter_pktgen_send_packet(self, pktsize: int) -> str:
+        """Generate and send packet to the SUT.
+
+        Functional test for scatter packets.
+
+        Args:
+            pktsize: Size of the packet to generate and send.
+        """
+        packet = Ether() / IP() / Raw()
+        packet.getlayer(2).load = ""
+        payload_len = pktsize - len(packet) - 4
+        payload = ["58"] * payload_len
+        # pack the payload
+        for X_in_hex in payload:
+            packet.load += struct.pack("=B", int("%s%s" % (X_in_hex[0], X_in_hex[1]), 16))
+        load = hexstr(packet.getlayer(2), onlyhex=1)
+        received_packets = self.send_packet_and_capture(packet)
+        self.verify(len(received_packets) > 0, "Did not receive any packets.")
+        load = hexstr(received_packets[0].getlayer(2), onlyhex=1)
+
+        return load
+
+    def pmd_scatter(self) -> None:
+        """Testpmd support of receiving and sending scattered multi-segment packets.
+
+        Support for scattered packets is shown by sending 5 packets of differing length
+        where the length of the packet is calculated by taking mbuf-size + an offset. The
+        offsets used in the test case are -1, 0, 1, 4, 5 respectively.
+
+        Test:
+            Start testpmd and run functional test with preset mbsize.
+        """
+        testpmd = self.sut_node.create_interactive_shell(
+            TestPmdShell,
+            app_parameters=(
+                "--mbcache=200 "
+                f"--mbuf-size={self.mbsize} "
+                "--max-pkt-len=9000 "
+                "--port-topology=paired "
+                "--tx-offloads=0x00008000"
+            ),
+            privileged=True,
+        )
+        testpmd.set_forward_mode(TestPmdForwardingModes.mac)
+        testpmd.start()
+        link_is_up = testpmd.wait_link_status_up(0) and testpmd.wait_link_status_up(1)
+        self.verify(link_is_up, "Links never came up in TestPMD.")
+
+        for offset in [-1, 0, 1, 4, 5]:
+            recv_payload = self.scatter_pktgen_send_packet(self.mbsize + offset)
+            self.verify(
+                ("58 " * 8).strip() in recv_payload,
+                "Received packet had incorrect payload",
+            )
+        testpmd.stop()
+
+    def test_scatter_mbuf_2048(self) -> None:
+        """Run :func:`~PmdBufferScatter.pmd_scatter` function after setting the `mbsize` to 2048."""
+        self.mbsize = 2048
+        self.pmd_scatter()
+
+    def tear_down_suite(self) -> None:
+        self.tg_node.main_session.configure_port_mtu(1500, self._tg_port_egress)
+        self.tg_node.main_session.configure_port_mtu(1500, self._tg_port_ingress)
-- 
2.43.0