Re: [PATCH bpf-next v5 15/15] selftests/bpf: Tests for BPF_SK_LOOKUP attach point

[Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx>]

On Fri, Jul 17, 2020 at 3:36 AM Jakub Sitnicki <jakub@xxxxxxxxxxxxxx> wrote:
>
> Add tests to test_progs that exercise:
>
>  - attaching/detaching/querying programs to BPF_SK_LOOKUP hook,
>  - redirecting socket lookup to a socket selected by BPF program,
>  - failing a socket lookup on BPF program's request,
>  - error scenarios for selecting a socket from BPF program,
>  - accessing BPF program context,
>  - attaching and running multiple BPF programs.
>
> Run log:
>
>   bash-5.0# ./test_progs -n 70
>   #70/1 query lookup prog:OK
>   #70/2 TCP IPv4 redir port:OK
>   #70/3 TCP IPv4 redir addr:OK
>   #70/4 TCP IPv4 redir with reuseport:OK
>   #70/5 TCP IPv4 redir skip reuseport:OK
>   #70/6 TCP IPv6 redir port:OK
>   #70/7 TCP IPv6 redir addr:OK
>   #70/8 TCP IPv4->IPv6 redir port:OK
>   #70/9 TCP IPv6 redir with reuseport:OK
>   #70/10 TCP IPv6 redir skip reuseport:OK
>   #70/11 UDP IPv4 redir port:OK
>   #70/12 UDP IPv4 redir addr:OK
>   #70/13 UDP IPv4 redir with reuseport:OK
>   #70/14 UDP IPv4 redir skip reuseport:OK
>   #70/15 UDP IPv6 redir port:OK
>   #70/16 UDP IPv6 redir addr:OK
>   #70/17 UDP IPv4->IPv6 redir port:OK
>   #70/18 UDP IPv6 redir and reuseport:OK
>   #70/19 UDP IPv6 redir skip reuseport:OK
>   #70/20 TCP IPv4 drop on lookup:OK
>   #70/21 TCP IPv6 drop on lookup:OK
>   #70/22 UDP IPv4 drop on lookup:OK
>   #70/23 UDP IPv6 drop on lookup:OK
>   #70/24 TCP IPv4 drop on reuseport:OK
>   #70/25 TCP IPv6 drop on reuseport:OK
>   #70/26 UDP IPv4 drop on reuseport:OK
>   #70/27 TCP IPv6 drop on reuseport:OK
>   #70/28 sk_assign returns EEXIST:OK
>   #70/29 sk_assign honors F_REPLACE:OK
>   #70/30 sk_assign accepts NULL socket:OK
>   #70/31 access ctx->sk:OK
>   #70/32 narrow access to ctx v4:OK
>   #70/33 narrow access to ctx v6:OK
>   #70/34 sk_assign rejects TCP established:OK
>   #70/35 sk_assign rejects UDP connected:OK
>   #70/36 multi prog - pass, pass:OK
>   #70/37 multi prog - drop, drop:OK
>   #70/38 multi prog - pass, drop:OK
>   #70/39 multi prog - drop, pass:OK
>   #70/40 multi prog - pass, redir:OK
>   #70/41 multi prog - redir, pass:OK
>   #70/42 multi prog - drop, redir:OK
>   #70/43 multi prog - redir, drop:OK
>   #70/44 multi prog - redir, redir:OK
>   #70 sk_lookup:OK
>   Summary: 1/44 PASSED, 0 SKIPPED, 0 FAILED
>
> Signed-off-by: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>
> ---
>

Hey Jakub!

We are getting this failure in Travis CI when syncing libbpf [0]:

```
ip: either "local" is duplicate, or "nodad" is garbage

switch_netns:PASS:unshare 0 nsec

switch_netns:FAIL:system failed

(/home/travis/build/libbpf/libbpf/travis-ci/vmtest/bpf-next/tools/testing/selftests/bpf/prog_tests/sk_lookup.c:1310:
errno: No such file or directory) system(ip -6 addr add dev lo
fd00::1/128 nodad)

#73 sk_lookup:FAIL
```


Can you please help fix it so that it works in a Travis CI environment
as well? For now I disabled sk_lookup selftests altogether. You can
try to repro it locally by forking https://github.com/libbpf/libbpf
and enabling Travis CI for your account. See [1] for the PR that
disabled sk_lookup.


  [0] https://travis-ci.com/github/libbpf/libbpf/jobs/365878309#L5408
  [1] https://github.com/libbpf/libbpf/pull/182/commits/78368c2eaed8b0681381fc34d6016c9b5a443be8


Thanks for your help!