Error during test run: NameError: global name 'TCP' is not defined

[tbenjamin-pl]

Dear all,

I have installed the switch according to the instructions in this project's README.md

When I
/mnt/NFS/switch/bmv2# ./run_tests.sh

I get an error while running the switch.L2VxlanTunnelTest
NameError: global name 'TCP' is not defined

Full output of error at end of this message. Please excuse that it is not preformatted. I don't know of an easy way to do this for large chunks of output.

When I do a grep -R over the test directories I do not see TCP defined anywhere.

I imagine it is supposed to come from one of the libraries imported, but it is hard to tell because two of the imports are of the form "from foo.bar import *"

Is this perhaps a library version conflict? I used the recommended install scripts and therefore have the correct versions of whatever has version numbers specified in those scripts.

Code version is current master: 92afb04
Ubuntu 16.04.6
Python 2.7.12

switch.L2VxlanTunnelTest ...
Cleaning state
Sending packet port 1 -> port 2 - Vxlan tunnel encap
Inner packet (192.168.10.1 -> 192.168.20.2 [id = 101])
Outer packet (10.10.10.1 -> 10.10.10.2 [vnid = 0x1234, id = 101])
ERROR

======================================================================
ERROR: switch.L2VxlanTunnelTest

Traceback (most recent call last):
File "/mnt/NFS/switch/tests/ptf-tests/pd-tests/switch.py", line 500, in runTest
udp_sport = entropy_hash(pkt1)
File "/mnt/NFS/switch/tests/ptf-tests/pd-tests/../common/utils.py", line 314, in entropy_hash
buff += str(hex(pkt[TCP].sport)[2:]).zfill(4)
NameError: global name 'TCP' is not defined

---

[tbenjamin-pl]

I posted the following to the slack channel:

I'm working on an issue I put in the tracker for switch: #107
I'm seeing something I don't understand. The global name IP which is used in the code nearby the error I'm seeing seems to come from ptf.testutils . I notice it defined in the file packet.py https://github.com/p4lang/ptf/blob/7b0af83e95dbb37ea793d5c2b884da9637ac67c4/src/ptf/packet.py#L28
The thing is, I also see TCP defined there. In order to check whether that is the definition of IP being used by the tests I commented out that assignment in packet.py, reinstalled the library, imported ptf.testutils *, did a print IP
Got the message IP not defined. So why would setting IP = scapy.layers.inet.IP in packet.py cause that name to be visible when ptf.testutils gets imported, but TCP = scapy.layers.inet.TCP is not visible?
I'll add this discussion to the ticket I have open. Do you think I should move this issue from the switch project to the ptf project?

[tbenjamin-pl]

I figured out the problem. https://github.com/p4lang/scapy-vxlan must be installed for this test to work.

Here is a version of README.md with a fix. If someone feels like giving me access I'll put in a pull request.

README.md.gz