These TAP interfaces can be used with Wireshark or tcpdump or Pktgen-DPDK
along with being able to be used as a network connection to the DPDK
application. The method enable one or more interfaces is to use the
-``--vdev=net_tap`` option on the DPDK application command line. Each
-``--vdev=net_tap`` option give will create an interface named dtap0, dtap1,
+``--vdev=net_tap0`` option on the DPDK application command line. Each
+``--vdev=net_tap1`` option given will create an interface named dtap0, dtap1,
and so on.
-The interfaced name can be changed by adding the ``iface=foo0``, for example::
+The interface name can be changed by adding the ``iface=foo0``, for example::
- --vdev=net_tap,iface=foo0 --vdev=net_tap,iface=foo1, ...
+ --vdev=net_tap0,iface=foo0 --vdev=net_tap1,iface=foo1, ...
Also the speed of the interface can be changed from 10G to whatever number
needed, but the interface does not enforce that speed, for example::
- --vdev=net_tap,iface=foo0,speed=25000
+ --vdev=net_tap0,iface=foo0,speed=25000
+
+Normally the PMD will generate a random MAC address, but when testing or with
+a static configuration the developer may need a fixed MAC address style.
+Using the option ``mac=fixed`` you can create a fixed known MAC address::
+
+ --vdev=net_tap0,mac=fixed
+
+The MAC address will have a fixed value with the last octet incrementing by one
+for each interface string containing ``mac=fixed``. The MAC address is formatted
+as 00:'d':'t':'a':'p':[00-FF]. Convert the characters to hex and you get the
+actual MAC address: ``00:64:74:61:70:[00-FF]``.
+
+It is possible to specify a remote netdevice to capture packets from by adding
+``remote=foo1``, for example::
+
+ --vdev=net_tap,iface=tap0,remote=foo1
+
+If a ``remote`` is set, the tap MAC address will be set to match the remote one
+just after netdevice creation. Using TC rules, traffic from the remote netdevice
+will be redirected to the tap. If the tap is in promiscuous mode, then all
+packets will be redirected. In allmulti mode, all multicast packets will be
+redirected.
+
+Using the remote feature is especially useful for capturing traffic from a
+netdevice that has no support in the DPDK. It is possible to add explicit
+rte_flow rules on the tap PMD to capture specific traffic (see next section for
+examples).
After the DPDK application is started you can send and receive packets on the
interface using the standard rx_burst/tx_burst APIs in DPDK. From the host
to address the interface using an IP address assigned to the internal
interface.
+Flow API support
+----------------
+
+The tap PMD supports major flow API pattern items and actions, when running on
+linux kernels above 4.2 ("Flower" classifier required).
+The kernel support can be checked with this command::
+
+ zcat /proc/config.gz | ( grep 'CLS_FLOWER=' || echo 'not supported' ) |
+ tee -a /dev/stderr | grep -q '=m' &&
+ lsmod | ( grep cls_flower || echo 'try modprobe cls_flower' )
+
+Supported items:
+
+- eth: src and dst (with variable masks), and eth_type (0xffff mask).
+- vlan: vid, pcp, tpid, but not eid. (requires kernel 4.9)
+- ipv4/6: src and dst (with variable masks), and ip_proto (0xffff mask).
+- udp/tcp: src and dst port (0xffff) mask.
+
+Supported actions:
+
+- DROP
+- QUEUE
+- PASSTHRU
+
+It is generally not possible to provide a "last" item. However, if the "last"
+item, once masked, is identical to the masked spec, then it is supported.
+
+Only IPv4/6 and MAC addresses can use a variable mask. All other items need a
+full mask (exact match).
+
+As rules are translated to TC, it is possible to show them with something like::
+
+ tc -s filter show dev tap1 parent 1:
+
+Examples of testpmd flow rules
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Drop packets for destination IP 192.168.0.1::
+
+ testpmd> flow create 0 priority 1 ingress pattern eth / ipv4 dst is 1.1.1.1 \
+ / end actions drop / end
+
+Ensure packets from a given MAC address are received on a queue 2::
+
+ testpmd> flow create 0 priority 2 ingress pattern eth src is 06:05:04:03:02:01 \
+ / end actions queue index 2 / end
+
+Drop UDP packets in vlan 3::
+
+ testpmd> flow create 0 priority 3 ingress pattern eth / vlan vid is 3 / \
+ ipv4 proto is 17 / end actions drop / end
+
Example
-------
sudo ./app/app/x86_64-native-linuxapp-gcc/app/pktgen -l 1-5 -n 4 \
--proc-type auto --log-level 8 --socket-mem 512,512 --file-prefix pg \
- --vdev=net_tap --vdev=net_tap -b 05:00.0 -b 05:00.1 \
+ --vdev=net_tap0 --vdev=net_tap1 -b 05:00.0 -b 05:00.1 \
-b 04:00.0 -b 04:00.1 -b 04:00.2 -b 04:00.3 \
-b 81:00.0 -b 81:00.1 -b 81:00.2 -b 81:00.3 \
-b 82:00.0 -b 83:00.0 -- -T -P -m [2:3].0 -m [4:5].1 \
While running you should see the 64 byte counters increasing to verify the
traffic is being looped back. You can use ``set all size XXX`` to change the
-size of the packets after you stop the traffic. Use the pktgen ``help``
+size of the packets after you stop the traffic. Use pktgen ``help``
command to see a list of all commands. You can also use the ``-f`` option to
-load commands at startup.
+load commands at startup in command line or Lua script in pktgen.
git.droids-corp.org / dpdk.git / blobdiff