From: Quanye Yang <quanyeyang@proton.me>

connect_one_server() reads the echoed payload in a loop because
read() on a stream socket can return a partial chunk. After the
loop, it still passed the last read() return value to
do_getsockopts() instead of the accumulated byte count.

do_getsockopt_tcp_info() then compared the subflow TCP counters
against that partial size, polled until timeout, and failed the
test. Use the total instead.

Fixes: ce9979129a0b ("selftests: mptcp: add mptcp getsockopt test cases")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/638
Signed-off-by: Quanye Yang <quanyeyang@proton.me>
---
 tools/testing/selftests/net/mptcp/mptcp_sockopt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
index b6e58d936ebe..7b4ccbe10ae1 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
@@ -627,7 +627,7 @@ static void connect_one_server(int fd, int pipefd)
 	if (s.tcpi_rcv_delta)
 		assert(s.tcpi_rcv_delta <= total);
 
-	do_getsockopts(&s, fd, ret, ret);
+	do_getsockopts(&s, fd, total, total);
 
 	if (eof)
 		total += 1; /* sequence advances due to FIN */

---
base-commit: a22035be824449c4921ec406f6383089016a628c
change-id: 20261015-fix-mptcp-issue-638-ec1dd30f7295

Best regards,
--  
Quanye Yang <quanyeyang@proton.me>

Hi Quanye,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal (except selftest_mptcp_join): Success! ✅
- KVM Validation: normal (only selftest_mptcp_join): Success! ✅
- KVM Validation: debug (except selftest_mptcp_join): Success! ✅
- KVM Validation: debug (only selftest_mptcp_join): Success! ✅
- KVM Validation: btf-normal (only bpftest_all): Success! ✅
- KVM Validation: btf-debug (only bpftest_all): Success! ✅
- Perf: Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/38728967786

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/03d4b1c8dc3f
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=1186397


If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:

    $ cd [kernel source code]
    $ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
        --pull always mptcp/mptcp-upstream-virtme-docker:latest \
        auto-normal

For more details:

    https://github.com/multipath-tcp/mptcp-upstream-virtme-docker


Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)