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diff --git a/docs/testing/user/userguide/trafficcapture.rst b/docs/testing/user/userguide/trafficcapture.rst new file mode 100644 index 00000000..fa09bfed --- /dev/null +++ b/docs/testing/user/userguide/trafficcapture.rst @@ -0,0 +1,297 @@ +Traffic Capture +--------------- + +Tha ability to capture traffic at multiple points of the system is crucial to +many of the functional tests. It allows the verification of functionality for +both the vSwitch and the NICs using hardware acceleration for packet +manipulation and modification. + +There are three different methods of traffic capture supported by VSPERF. +Detailed descriptions of these methods as well as their pros and cons can be +found in the following chapters. + +Traffic Capture inside of a VM +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +This method uses the standard PVP scenario, in which vSwitch first processes +and modifies the packet before forwarding it to the VM. Inside of the VM we +capture the traffic using **tcpdump** or a similiar technique. The capture +information is the used to verify the expected modifications to the packet done +by vSwitch. + +.. code-block:: console + + _ + +--------------------------------------------------+ | + | | | + | +------------------------------------------+ | | + | | Traffic capture and Packet Forwarding | | | + | +------------------------------------------+ | | + | ^ : | | + | | | | | Guest + | : v | | + | +---------------+ +---------------+ | | + | | logical port 0| | logical port 1| | | + +---+---------------+----------+---------------+---+ _| + ^ : + | | + : v _ + +---+---------------+----------+---------------+---+ | + | | logical port 0| | logical port 1| | | + | +---------------+ +---------------+ | | + | ^ : | | + | | | | | Host + | : v | | + | +--------------+ +--------------+ | | + | | phy port | vSwitch | phy port | | | + +---+--------------+------------+--------------+---+ _| + ^ : + | | + : v + +--------------------------------------------------+ + | | + | traffic generator | + | | + +--------------------------------------------------+ + +PROS: + +- supports testing with all traffic generators +- easy to use and implement into test +- allows testing hardware offloading on the ingress side + +CONS: + +- does not allow testing hardware offloading on the egress side + +An example of Traffic Capture in VM test: + +.. code-block:: python + + # Capture Example 1 - Traffic capture inside VM (PVP scenario) + # This TestCase will modify VLAN ID set by the traffic generator to the new value. + # Correct VLAN ID settings is verified by inspection of captured frames. + { + Name: capture_pvp_modify_vid, + Deployment: pvp, + Description: Test and verify VLAN ID modification by Open vSwitch, + Parameters : { + VSWITCH : OvsDpdkVhost, # works also for Vanilla OVS + TRAFFICGEN_DURATION : 5, + TRAFFIC : { + traffic_type : rfc2544_continuous, + frame_rate : 100, + 'vlan': { + 'enabled': True, + 'id': 8, + 'priority': 1, + 'cfi': 0, + }, + }, + GUEST_LOOPBACK : ['linux_bridge'], + }, + TestSteps: [ + # replace original flows with vlan ID modification + ['!vswitch', 'add_flow', 'br0', {'in_port': '1', 'actions': ['mod_vlan_vid:4','output:3']}], + ['!vswitch', 'add_flow', 'br0', {'in_port': '2', 'actions': ['mod_vlan_vid:4','output:4']}], + ['vswitch', 'dump_flows', 'br0'], + # verify that received frames have modified vlan ID + ['VNF0', 'execute_and_wait', 'tcpdump -i eth0 -c 5 -w dump.pcap vlan 4 &'], + ['trafficgen', 'send_traffic',{}], + ['!VNF0', 'execute_and_wait', 'tcpdump -qer dump.pcap vlan 4 2>/dev/null | wc -l','|^(\d+)$'], + ['tools', 'assert', '#STEP[-1][0] == 5'], + ], + }, + +Traffic Capture for testing NICs with HW offloading/acceleration +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The NIC with hardware acceleration/offloading is inserted as an additional card +into the server. Two ports on this card are then connected together using +a patch cable as shown in the diagram. Only a single port of the tested NIC is +setup with DPDK acceleration, while the other is handled by the Linux Ip stack +allowing for traffic capture. The two NICs are then connected by vSwitch so the +original card can forward the processed packets to the traffic generator. The +ports handled by Linux IP stack allow for capturing packets, which are then +analyzed for changes done by both the vSwitch and the NIC with hardware +acceleration. + +.. code-block:: console + + _ + +------------------------------------------------+ | + | | | + | +----------------------------------------+ | | + | | vSwitch | | | + | | +----------------------------------+ | | | + | | | | | | | + | | | +------------------+ | | | | + | | | | | v | | | + | +----------------------------------------+ | | Device under Test + | ^ | ^ | | | + | | | | | | | + | | v | v | | + | +--------------+ +--------------+ | | + | | | | NIC w HW acc | | | + | | phy ports | | phy ports | | | + +---+--------------+----------+--------------+---+ _| + ^ : ^ : + | | | | + | | +-------+ + : v Patch Cable + +------------------------------------------------+ + | | + | traffic generator | + | | + +------------------------------------------------+ + +PROS: + +- allows testing hardware offloading on both the ingress and egress side +- supports testing with all traffic generators +- relatively easy to use and implement into tests + +CONS: + +- a more complex setup with two cards +- if the tested card only has one port, an additional card is needed + +An example of Traffic Capture for testing NICs with HW offloading test: + +.. code-block:: python + + # Capture Example 2 - Setup with 2 NICs, where traffic is captured after it is + # processed by NIC under the test (2nd NIC). See documentation for further details. + # This TestCase will strip VLAN headers from traffic sent by the traffic generator. + # The removal of VLAN headers is verified by inspection of captured frames. + # + # NOTE: This setup expects a DUT with two NICs with two ports each. First NIC is + # connected to the traffic generator (standard VSPERF setup). Ports of a second NIC + # are interconnected by a patch cable. PCI addresses of all four ports have to be + # properly configured in the WHITELIST_NICS parameter. + { + Name: capture_p2p2p_strip_vlan_ovs, + Deployment: clean, + Description: P2P Continuous Stream, + Parameters : { + _CAPTURE_P2P2P_OVS_ACTION : 'strip_vlan', + TRAFFIC : { + bidir : False, + traffic_type : rfc2544_continuous, + frame_rate : 100, + 'l2': { + 'srcmac': ca:fe:00:00:00:00, + 'dstmac': 00:00:00:00:00:01 + }, + 'vlan': { + 'enabled': True, + 'id': 8, + 'priority': 1, + 'cfi': 0, + }, + }, + # suppress DPDK configuration, so physical interfaces are not bound to DPDK driver + 'WHITELIST_NICS' : [], + 'NICS' : [], + }, + TestSteps: _CAPTURE_P2P2P_SETUP + [ + # capture traffic after processing by NIC under the test (after possible egress HW offloading) + ['tools', 'exec_shell_background', 'tcpdump -i [2][device] -c 5 -w capture.pcap ' + 'ether src [l2][srcmac]'], + ['trafficgen', 'send_traffic', {}], + ['vswitch', 'dump_flows', 'br0'], + ['vswitch', 'dump_flows', 'br1'], + # there must be 5 captured frames... + ['tools', 'exec_shell', 'tcpdump -r capture.pcap | wc -l', '|^(\d+)$'], + ['tools', 'assert', '#STEP[-1][0] == 5'], + # ...but no vlan headers + ['tools', 'exec_shell', 'tcpdump -r capture.pcap vlan | wc -l', '|^(\d+)$'], + ['tools', 'assert', '#STEP[-1][0] == 0'], + ], + }, + + +Traffic Capture on the Traffic Generator +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Using the functionality of the Traffic generator makes it possible to configure +Traffic Capture on both it's ports. With Traffic Capture enabled, VSPERF +instructs the Traffic Generator to automatically export captured data into +a pcap file. The captured packets are then sent to VSPERF for analysis and +verification, monitoring any changes done by both vSwitch and the NICs. + +Vsperf currently only supports this functionality with the **T-Rex** generator. + +.. code-block:: console + + _ + +--------------------------------------------------+ | + | | | + | +--------------------------+ | | + | | | | | + | | v | | Host + | +--------------+ +--------------+ | | + | | phy port | vSwitch | phy port | | | + +---+--------------+------------+--------------+---+ _| + ^ : + | | + : v + +--------------------------------------------------+ + | | + | traffic generator | + | | + +--------------------------------------------------+ + +PROS: + +- allows testing hardware offloading on both the ingress and egress side +- does not require an additional NIC + +CONS: + +- currently only supported by **T-Rex** traffic generator + +An example Traffic Capture on the Traffic Generator test: + +.. code-block:: python + + + # Capture Example 3 - Traffic capture by traffic generator. + # This TestCase uses OVS flow to add VLAN tag with given ID into every + # frame send by traffic generator. Correct frame modificaiton is verified by + # inspection of packet capture received by T-Rex. + { + Name: capture_p2p_add_vlan_ovs_trex, + Deployment: clean, + Description: OVS: Test VLAN tag modification and verify it by traffic capture, + vSwitch : OvsDpdkVhost, # works also for Vanilla OVS + Parameters : { + TRAFFICGEN : Trex, + TRAFFICGEN_DURATION : 5, + TRAFFIC : { + traffic_type : rfc2544_continuous, + frame_rate : 100, + # enable capture of five RX frames + 'capture': { + 'enabled': True, + 'tx_ports' : [], + 'rx_ports' : [1], + 'count' : 5, + }, + }, + }, + TestSteps : STEP_VSWITCH_P2P_INIT + [ + # replace standard L2 flows by flows, which will add VLAN tag with ID 3 + ['!vswitch', 'add_flow', 'int_br0', {'in_port': '1', 'actions': ['mod_vlan_vid:3','output:2']}], + ['!vswitch', 'add_flow', 'int_br0', {'in_port': '2', 'actions': ['mod_vlan_vid:3','output:1']}], + ['vswitch', 'dump_flows', 'int_br0'], + ['trafficgen', 'send_traffic', {}], + ['trafficgen', 'get_results'], + # verify that captured frames have vlan tag with ID 3 + ['tools', 'exec_shell', 'tcpdump -qer /#STEP[-1][0][capture_rx] vlan 3 ' + '2>/dev/null | wc -l', '|^(\d+)$'], + # number of received frames with expected VLAN id must match the number of captured frames + ['tools', 'assert', '#STEP[-1][0] == 5'], + ] + STEP_VSWITCH_P2P_FINIT, + }, + |