Re: packetdrill: updates on building and testing packetdrill on LKFT

[Neal Cardwell]

Hi,

Thanks for the report!

What exact kernel version are you testing?

We can offer advice, but I'm afraid our team does not have cycles to track down and fix those test failures in your environment.

In some cases, you will probably want to update your environment. For example, I would recommend enabling CONFIG_SYN_COOKIES, since that should give a much more robust and typical Linux TCP stack.

In other cases, your kernels may have different behavior, for various reasons (local patches or atypical .config), that will require you to modify the tests to expect your behavior.

In other cases the upstream net-next behavior may have diverged from what these tests in the github packetdrill repo expect. If someone in the Linux networking community wants to submit pull requests to update the tests to expect the latest net-next behavior, we are happy to  review and merge those. Our team has cycles to maintain our internal branches of these tests to match the behavior in our environment, but unfortunately does not have time to strictly keep all upstream tests up-to-date with respect to matching net-next behavior.

best,

neal

On Mon, Feb 22, 2021 at 2:19 AM Naresh Kamboju <naresh....@linaro.org> wrote:

We (Linaro) started exploring options to run packetdrill on Linux kernel for
improving network subsystem test coverage. The following results obtained
on arm64 and x86_64 architectures after installing required packages on the
debian rootfs. The run time of testing is less than a minute.
Full run test log attached to this email.

Please suggest ways to improve the number of PASS.
Our plan is to add the packetdrill test suite to LKFT [1] test plan.

arm64:
Ran 234 tests: 199 passing, 35 failing, 0 timed out (36.00 sec): .

x86_64:
Ran  234 tests:  192 passing,   42 failing,    0 timed out (23.14 sec): .

steps:
          - apt-get update
          - apt-get -y install build-essential python git python3 automake
          - apt-get -y install iproute2 net-tools ethtool  bison flex
          - git clone https://github.com/google/packetdrill
          - cd packetdrill/gtests/net/packetdrill/
          - ./configure
          - make
          - cd ../
          - ./packetdrill/run_all.py -v -l -L

Errors list:
-------------
 - error handling packet: live packet payload: expected 1000 bytes vs
actual 2000 bytes
 - runtime error in socket call: Expected non-negative result but got
-1 with errno 93 (Protocol not supported)
 - timing error: expected system call return at 0.300556 sec but
happened at 0.310599 sec; tolerance 0.010000 sec
 - sysctl: cannot stat /proc/sys/net/ipv4/tcp_syncookies: No such file
or directory
     - comment CONFIG_SYN_COOKIES not enabled on arm64 but set on x86_64.
 - sysctl: cannot stat /proc/sys/net/ipv4/tcp_syncookies: No such file
or directory
 - cwnd-moderation-ecn-enter-cwr-no-moderation-700.pkt:24: error in Python code
   Traceback (most recent call last):
      File \"/tmp/code_nVK70l\", line 195, in <module>
        assert tcpi_snd_cwnd == 4, tcpi_snd_cwnd
    AssertionError: 5
cwnd-moderation-ecn-enter-cwr-no-moderation-700.pkt: error executing
code: '/usr/bin/python' returned non-zero status 1

[1] https://lkft.linaro.org/tests/


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Linaro LKFT
https://lkft.linaro.org