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

[Daniel Borkmann <daniel@xxxxxxxxxxxxx>]

On 7/28/20 10:13 PM, Andrii Nakryiko wrote:
> 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
> ```

Jakub, I'm actually seeing a slightly different one on my test machine with sk_lookup:

# ./test_progs -t sk_lookup
#14 cgroup_skb_sk_lookup:OK
#73/1 query lookup prog:OK
#73/2 TCP IPv4 redir port:OK
#73/3 TCP IPv4 redir addr:OK
#73/4 TCP IPv4 redir with reuseport:OK
#73/5 TCP IPv4 redir skip reuseport:OK
#73/6 TCP IPv6 redir port:OK
#73/7 TCP IPv6 redir addr:OK
#73/8 TCP IPv4->IPv6 redir port:OK
#73/9 TCP IPv6 redir with reuseport:OK
#73/10 TCP IPv6 redir skip reuseport:OK
#73/11 UDP IPv4 redir port:OK
#73/12 UDP IPv4 redir addr:OK
#73/13 UDP IPv4 redir with reuseport:OK
attach_lookup_prog:PASS:open 0 nsec
attach_lookup_prog:PASS:bpf_program__attach_netns 0 nsec
make_socket:PASS:make_address 0 nsec
make_socket:PASS:socket 0 nsec
make_socket:PASS:setsockopt(SO_SNDTIMEO) 0 nsec
make_socket:PASS:setsockopt(SO_RCVTIMEO) 0 nsec
make_server:PASS:setsockopt(IP_RECVORIGDSTADDR) 0 nsec
make_server:PASS:setsockopt(SO_REUSEPORT) 0 nsec
make_server:PASS:bind 0 nsec
make_server:PASS:attach_reuseport 0 nsec
update_lookup_map:PASS:bpf_map__fd 0 nsec
update_lookup_map:PASS:bpf_map_update_elem 0 nsec
make_socket:PASS:make_address 0 nsec
make_socket:PASS:socket 0 nsec
make_socket:PASS:setsockopt(SO_SNDTIMEO) 0 nsec
make_socket:PASS:setsockopt(SO_RCVTIMEO) 0 nsec
make_server:PASS:setsockopt(IP_RECVORIGDSTADDR) 0 nsec
make_server:PASS:setsockopt(SO_REUSEPORT) 0 nsec
make_server:PASS:bind 0 nsec
make_server:PASS:attach_reuseport 0 nsec
update_lookup_map:PASS:bpf_map__fd 0 nsec
update_lookup_map:PASS:bpf_map_update_elem 0 nsec
make_socket:PASS:make_address 0 nsec
make_socket:PASS:socket 0 nsec
make_socket:PASS:setsockopt(SO_SNDTIMEO) 0 nsec
make_socket:PASS:setsockopt(SO_RCVTIMEO) 0 nsec
make_server:PASS:setsockopt(IP_RECVORIGDSTADDR) 0 nsec
make_server:PASS:setsockopt(SO_REUSEPORT) 0 nsec
make_server:PASS:bind 0 nsec
make_server:PASS:attach_reuseport 0 nsec
run_lookup_prog:PASS:getsockname 0 nsec
run_lookup_prog:PASS:connect 0 nsec
make_socket:PASS:make_address 0 nsec
make_socket:PASS:socket 0 nsec
make_socket:PASS:setsockopt(SO_SNDTIMEO) 0 nsec
make_socket:PASS:setsockopt(SO_RCVTIMEO) 0 nsec
make_client:PASS:make_client 0 nsec
send_byte:PASS:send_byte 0 nsec
udp_recv_send:FAIL:recvmsg failed
(/root/bpf-next/tools/testing/selftests/bpf/prog_tests/sk_lookup.c:339: errno: Resource temporarily unavailable) failed to receive
#73/14 UDP IPv4 redir and reuseport with conns:FAIL
#73/15 UDP IPv4 redir skip reuseport:OK
#73/16 UDP IPv6 redir port:OK
#73/17 UDP IPv6 redir addr:OK
#73/18 UDP IPv4->IPv6 redir port:OK
#73/19 UDP IPv6 redir and reuseport:OK
attach_lookup_prog:PASS:open 0 nsec
attach_lookup_prog:PASS:bpf_program__attach_netns 0 nsec
make_socket:PASS:make_address 0 nsec
make_socket:PASS:socket 0 nsec
make_socket:PASS:setsockopt(SO_SNDTIMEO) 0 nsec
make_socket:PASS:setsockopt(SO_RCVTIMEO) 0 nsec
make_server:PASS:setsockopt(IP_RECVORIGDSTADDR) 0 nsec
make_server:PASS:setsockopt(IPV6_RECVORIGDSTADDR) 0 nsec
make_server:PASS:setsockopt(SO_REUSEPORT) 0 nsec
make_server:PASS:bind 0 nsec
make_server:PASS:attach_reuseport 0 nsec
update_lookup_map:PASS:bpf_map__fd 0 nsec
update_lookup_map:PASS:bpf_map_update_elem 0 nsec
make_socket:PASS:make_address 0 nsec
make_socket:PASS:socket 0 nsec
make_socket:PASS:setsockopt(SO_SNDTIMEO) 0 nsec
make_socket:PASS:setsockopt(SO_RCVTIMEO) 0 nsec
make_server:PASS:setsockopt(IP_RECVORIGDSTADDR) 0 nsec
make_server:PASS:setsockopt(IPV6_RECVORIGDSTADDR) 0 nsec
make_server:PASS:setsockopt(SO_REUSEPORT) 0 nsec
make_server:PASS:bind 0 nsec
make_server:PASS:attach_reuseport 0 nsec
update_lookup_map:PASS:bpf_map__fd 0 nsec
update_lookup_map:PASS:bpf_map_update_elem 0 nsec
make_socket:PASS:make_address 0 nsec
make_socket:PASS:socket 0 nsec
make_socket:PASS:setsockopt(SO_SNDTIMEO) 0 nsec
make_socket:PASS:setsockopt(SO_RCVTIMEO) 0 nsec
make_server:PASS:setsockopt(IP_RECVORIGDSTADDR) 0 nsec
make_server:PASS:setsockopt(IPV6_RECVORIGDSTADDR) 0 nsec
make_server:PASS:setsockopt(SO_REUSEPORT) 0 nsec
make_server:PASS:bind 0 nsec
make_server:PASS:attach_reuseport 0 nsec
run_lookup_prog:PASS:getsockname 0 nsec
run_lookup_prog:PASS:connect 0 nsec
make_socket:PASS:make_address 0 nsec
make_socket:PASS:socket 0 nsec
make_socket:PASS:setsockopt(SO_SNDTIMEO) 0 nsec
make_socket:PASS:setsockopt(SO_RCVTIMEO) 0 nsec
make_client:PASS:make_client 0 nsec
send_byte:PASS:send_byte 0 nsec
udp_recv_send:FAIL:recvmsg failed
(/root/bpf-next/tools/testing/selftests/bpf/prog_tests/sk_lookup.c:339: errno: Resource temporarily unavailable) failed to receive
#73/20 UDP IPv6 redir and reuseport with conns:FAIL
#73/21 UDP IPv6 redir skip reuseport:OK
#73/22 TCP IPv4 drop on lookup:OK
#73/23 TCP IPv6 drop on lookup:OK
#73/24 UDP IPv4 drop on lookup:OK
#73/25 UDP IPv6 drop on lookup:OK
#73/26 TCP IPv4 drop on reuseport:OK
#73/27 TCP IPv6 drop on reuseport:OK
#73/28 UDP IPv4 drop on reuseport:OK
#73/29 TCP IPv6 drop on reuseport:OK
#73/30 sk_assign returns EEXIST:OK
#73/31 sk_assign honors F_REPLACE:OK
#73/32 sk_assign accepts NULL socket:OK
#73/33 access ctx->sk:OK
#73/34 narrow access to ctx v4:OK
#73/35 narrow access to ctx v6:OK
#73/36 sk_assign rejects TCP established:OK
#73/37 sk_assign rejects UDP connected:OK
#73/38 multi prog - pass, pass:OK
#73/39 multi prog - drop, drop:OK
#73/40 multi prog - pass, drop:OK
#73/41 multi prog - drop, pass:OK
#73/42 multi prog - pass, redir:OK
#73/43 multi prog - redir, pass:OK
#73/44 multi prog - drop, redir:OK
#73/45 multi prog - redir, drop:OK
#73/46 multi prog - redir, redir:OK
#73 sk_lookup:FAIL
Summary: 1/44 PASSED, 0 SKIPPED, 3 FAILED

> 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!