[PATCH v2 1/4] dts: add send_packets to test suites and rework packet addressing

[jspewock@iol.unh.edu]

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

Currently the only method provided in the test suite class for sending
packets sends a single packet and then captures the results. There is,
in some cases, a need to send multiple packets at once while not really
needing to capture any traffic received back. The method to do this
exists in the traffic generator already, but this patch exposes the
method to test suites.

This patch also updates the _adjust_addresses method of test suites so
that addresses of packets are only modified if the developer did not
configure them beforehand. This allows for developers to have more
control over the content of their packets when sending them through the
framework.

Signed-off-by: Jeremy Spewock <jspewock@iol.unh.edu>
---
 dts/framework/test_suite.py            | 74 ++++++++++++++++++--------
 dts/framework/testbed_model/tg_node.py |  9 ++++
 2 files changed, 62 insertions(+), 21 deletions(-)

diff --git a/dts/framework/test_suite.py b/dts/framework/test_suite.py
index 694b2eba65..0b678ed62d 100644
--- a/dts/framework/test_suite.py
+++ b/dts/framework/test_suite.py
@@ -199,7 +199,7 @@ def send_packet_and_capture(
         Returns:
             A list of received packets.
         """
-        packet = self._adjust_addresses(packet)
+        packet = self._adjust_addresses([packet])[0]
         return self.tg_node.send_packet_and_capture(
             packet,
             self._tg_port_egress,
@@ -208,6 +208,18 @@ def send_packet_and_capture(
             duration,
         )
 
+    def send_packets(
+        self,
+        packets: list[Packet],
+    ) -> None:
+        """Send packets using the traffic generator and do not capture received traffic.
+
+        Args:
+            packets: Packets to send.
+        """
+        packets = self._adjust_addresses(packets)
+        self.tg_node.send_packets(packets, self._tg_port_egress)
+
     def get_expected_packet(self, packet: Packet) -> Packet:
         """Inject the proper L2/L3 addresses into `packet`.
 
@@ -219,39 +231,59 @@ def get_expected_packet(self, packet: Packet) -> Packet:
         """
         return self._adjust_addresses(packet, expected=True)
 
-    def _adjust_addresses(self, packet: Packet, expected: bool = False) -> Packet:
+    def _adjust_addresses(self, packets: list[Packet], expected: bool = False) -> list[Packet]:
         """L2 and L3 address additions in both directions.
 
+        Only missing addresses are added to packets, existing addressed will not be overridden.
+
         Assumptions:
             Two links between SUT and TG, one link is TG -> SUT, the other SUT -> TG.
 
         Args:
-            packet: The packet to modify.
+            packets: The packets to modify.
             expected: If :data:`True`, the direction is SUT -> TG,
                 otherwise the direction is TG -> SUT.
         """
-        if expected:
-            # The packet enters the TG from SUT
-            # update l2 addresses
-            packet.src = self._sut_port_egress.mac_address
-            packet.dst = self._tg_port_ingress.mac_address
+        ret_packets = []
+        for packet in packets:
+            default_pkt_src = type(packet)().src
+            default_pkt_dst = type(packet)().dst
+            default_pkt_payload_src = IP().src if hasattr(packet.payload, "src") else None
+            default_pkt_payload_dst = IP().dst if hasattr(packet.payload, "dst") else None
+            # If `expected` is :data:`True`, the packet enters the TG from SUT, otherwise the
+            # packet leaves the TG towards the SUT
 
-            # The packet is routed from TG egress to TG ingress
-            # update l3 addresses
-            packet.payload.src = self._tg_ip_address_egress.ip.exploded
-            packet.payload.dst = self._tg_ip_address_ingress.ip.exploded
-        else:
-            # The packet leaves TG towards SUT
             # update l2 addresses
-            packet.src = self._tg_port_egress.mac_address
-            packet.dst = self._sut_port_ingress.mac_address
+            if packet.src == default_pkt_src:
+                packet.src = (
+                    self._sut_port_egress.mac_address
+                    if expected
+                    else self._tg_port_egress.mac_address
+                )
+            if packet.dst == default_pkt_dst:
+                packet.dst = (
+                    self._tg_port_ingress.mac_address
+                    if expected
+                    else self._sut_port_ingress.mac_address
+                )
+
+            # The packet is routed from TG egress to TG ingress regardless of if it is expected or
+            # not.
 
-            # The packet is routed from TG egress to TG ingress
             # update l3 addresses
-            packet.payload.src = self._tg_ip_address_egress.ip.exploded
-            packet.payload.dst = self._tg_ip_address_ingress.ip.exploded
-
-        return Ether(packet.build())
+            if (
+                default_pkt_payload_src is not None
+                and packet.payload.src == default_pkt_payload_src
+            ):
+                packet.payload.src = self._tg_ip_address_egress.ip.exploded
+            if (
+                default_pkt_payload_dst is not None
+                and packet.payload.dst == default_pkt_payload_dst
+            ):
+                packet.payload.dst = self._tg_ip_address_ingress.ip.exploded
+            ret_packets.append(Ether(packet.build()))
+
+        return ret_packets
 
     def verify(self, condition: bool, failure_description: str) -> None:
         """Verify `condition` and handle failures.
diff --git a/dts/framework/testbed_model/tg_node.py b/dts/framework/testbed_model/tg_node.py
index 4ee326e99c..758b676258 100644
--- a/dts/framework/testbed_model/tg_node.py
+++ b/dts/framework/testbed_model/tg_node.py
@@ -83,6 +83,15 @@ def send_packet_and_capture(
             duration,
         )
 
+    def send_packets(self, packets: list[Packet], port: Port):
+        """Send packets without capturing resulting received packets.
+
+        Args:
+            packets: Packets to send.
+            port: Port to send the packets on.
+        """
+        self.traffic_generator.send_packets(packets, port)
+
     def close(self) -> None:
         """Free all resources used by the node.
 
-- 
2.45.2