On 20. 9. 2024 20:08, jspew...@iol.unh.edu wrote:
From: Jeremy Spewock <jspew...@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.
Patrick mentioned there is now a method that does it
(send_packets_and_capture()), but that one captures the packets. I think
we should add this method though, as it does something different, but
maybe the most important point is that non-capturing TGs are going to
support send_packets_and_capture(), so we need it either way.
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.
I think this could and should be split into two patches. They aren't
really connected.
diff --git a/dts/framework/test_suite.py b/dts/framework/test_suite.py
@@ -243,41 +255,74 @@ def get_expected_packet(self, packet: Packet) -> Packet:
Returns:
`packet` with injected L2/L3 addresses.
"""
- return self._adjust_addresses(packet, expected=True)
+ return self._adjust_addresses([packet], expected=True)[0]
- 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.
+ Packets in `packets` will be directly modified in this method. The returned list of packets
+ however will be copies of the modified packets in order to keep the
two lists distinct.
+
Do we need to do this? I guess you needed this in a test suite - what is
the reason?
+ Only missing addresses are added to packets, existing addresses will
not be overridden. If
+ any packet in `packets` has multiple IP layers (using GRE, for
example) only the inner-most
+ IP layer will have its addresses adjusted.
+
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.
+
+ Returns:
+ A list containing copies of all packets in `packets` after
modification.
"""
- 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:
+ # The fields parameter of a packet does not include fields of the
payload, so this can
+ # only be the Ether src/dst.
+ pkt_src_is_unset = "src" not in packet.fields
+ pkt_dst_is_unset = "dst" not in packet.fields
+ num_ip_layers = packet.layers().count(IP)
+
+ # Update the last IP layer if there are multiple to account for
GRE addressing (the
This comment should be more generic as it's going to apply to other
things than just GRE.
+ # framework should be modifying the packet address instead of the
tunnel).
+ l3_to_use = packet.getlayer(IP, num_ip_layers)
Would this make more sense inside the positive if branch right below?
+ if num_ip_layers > 0:
+ ip_src_is_unset = "src" not in l3_to_use.fields
+ ip_dst_is_unset = "dst" not in l3_to_use.fields
+ else:
+ ip_src_is_unset = None
+ ip_dst_is_unset = None
- # 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 `expected` is :data:`True`, the packet enters the TG from
SUT, otherwise the
+ # packet leaves the TG towards the SUT
+ if pkt_src_is_unset:
+ packet.src = (
+ self._sut_port_egress.mac_address
+ if expected
+ else self._tg_port_egress.mac_address
+ )
+ if pkt_dst_is_unset:
+ 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
# update l3 addresses
- packet.payload.src = self._tg_ip_address_egress.ip.exploded
- packet.payload.dst = self._tg_ip_address_ingress.ip.exploded
+ # The packet is routed from TG egress to TG ingress regardless of
whether it is
+ # expected or not.
Is this true? This might've been an error in the original
implementation. If it's expected (that is, the returning packet), it
should be routed from TG ingress to TG egress, no?
+ if ip_src_is_unset:
+ l3_to_use.src = self._tg_ip_address_egress.ip.exploded
+
+ if ip_dst_is_unset:
+ l3_to_use.dst = self._tg_ip_address_ingress.ip.exploded
+ ret_packets.append(Ether(packet.build()))
