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

[Daniel Borkmann <daniel@xxxxxxxxxxxxx>]

On 7/29/20 10:55 AM, Jakub Sitnicki wrote:
> Hi Daniel,
>
> On Tue, Jul 28, 2020 at 10:47 PM CEST, Daniel Borkmann wrote:
>
> [...]
>
> > 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
>
> This patch addresses the failures:
>
>    https://lore.kernel.org/bpf/20200726120228.1414348-1-jakub@xxxxxxxxxxxxxx/
>
> It spawned a discussion on what to do about reuseport bpf returning
> connected udp sockets, and the conclusion was that it would be best to
> change reuseport logic itself if no one is relying on said behavior.
>
> IOW, I belive the fix does the right thing and can be applied as is. We
> get the same reuseport behavior everywhere, that is with regular socket
> lookup and BPF sk lookup, even if that behavior needs to be changed.

Seems reasonable to me, I've applied it to bpf-next, thanks Jakub!