SUME simulation fails because of pkt.tuser_sport

mimeister commented 4 years ago

Hi, I'm currently trying to setup the SUME simulation as described in the switch-calc tutorial in step 9. Running the simulation with

$ ./tools/scripts/nf_test.py sim --major switch --minor default --gui

Vivado opens as intended, but aborts the simulation. The console tells me, that run.py threw an AttributeError (username and exact path replaced by '\<username>'):

loading libsume..
About to start the test
/home/<username>/P4-NetFPGA-live/contrib-projects/sume-sdnet-switch/projects/switch_calc/testdata/nf1_applied.pcap  not found
/home/<username>/P4-NetFPGA-live/contrib-projects/sume-sdnet-switch/projects/switch_calc/testdata/nf2_applied.pcap  not found
/home/<username>/P4-NetFPGA-live/contrib-projects/sume-sdnet-switch/projects/switch_calc/testdata/nf3_applied.pcap  not found
/home/<username>/P4-NetFPGA-live/contrib-projects/sume-sdnet-switch/projects/switch_calc/testdata/nf1_expected.pcap  not found
/home/<username>/P4-NetFPGA-live/contrib-projects/sume-sdnet-switch/projects/switch_calc/testdata/nf2_expected.pcap  not found
/home/<username>/P4-NetFPGA-live/contrib-projects/sume-sdnet-switch/projects/switch_calc/testdata/nf3_expected.pcap  not found
scheduling pkts ...
Traceback (most recent call last):
  File "/home/<username>/P4-NetFPGA-live/contrib-projects/sume-sdnet-switch/projects/switch_calc/simple_sume_switch/test/sim_switch_default/run.py", line 92, in <module>
    schedule_pkts(nf0_applied, 'nf0')
  File "/home/<username>/P4-NetFPGA-live/contrib-projects/sume-sdnet-switch/projects/switch_calc/simple_sume_switch/test/sim_switch_default/run.py", line 63, in schedule_pkts
    pkt.tuser_sport = nf_port_map[iface]
  File "/usr/lib/python2.7/dist-packages/scapy/packet.py", line 221, in __setattr__
    return object.__setattr__(self, attr, val)
AttributeError: 'Ether' object has no attribute 'tuser_sport'
    while executing
"exec python $::env(NF_DESIGN_DIR)/test/${test_name}/run.py"
    invoked from within
"set output [exec python $::env(NF_DESIGN_DIR)/test/${test_name}/run.py]"
    (file "/home/<username>/P4-NetFPGA-live/contrib-projects/sume-sdnet-switch/projects/switch_calc/simple_sume_switch/hw/tcl/simple_sume_switch_sim.tcl" line 177)

Origin of the error is the method schedule_pkts() in run.py, where the attribute tuser_sport is added dynamically to a Scapy packet instance:

def schedule_pkts(pkt_list, iface):
    print 'scheduling pkts ...'
    for pkt in pkt_list:
        pkt.time = baseTime + delta*pkt.time
        pkt.tuser_sport = nf_port_map[iface]
    print 'done scheduling pkts ...'

I could find even more attempts to add this attribute in other files, that will fail for sure, too.

After a lot of web search I could trace down the cause of the problem to be a change in Scapy four years ago, that introduced slots to most base classes, which prevents the dynamic addition of attributes.

Odd, that seemingly no one else here had stumbled upon this yet. :sweat_smile:

Additional information

OS: Ubuntu 18.04 Python: 2.7.17 Scapy: 2.3.3

salvatorg commented 4 years ago

Hi @species-gh, Thnx for pointing this out! I personally havent seen that error apparently because I have scapy version 2.2.0 in my system.

ralfkundel commented 4 years ago

Hi, i just tested in on multiple versions: 2.2.0 : working 2.3.3 : not working (apt install python-scapy on Ubuntu 18.04) 3.0.0 : working (apt install python3-scapy on Ubuntu 18.04)

regards, Ralf

mimeister commented 4 years ago

@ralfkundel found that adding attributes to packets works again in newer Scapy versions. So I switched to the current version available from the Scapy repo (2.4.3) and now the errors are gone. No need for a fix in the scripts :+1:

NetFPGA / P4-NetFPGA-public

SUME simulation fails because of pkt.tuser_sport #46

Additional information