selftests/bpf: Verify first of struct mptcp_sock

This patch verifies the 'first' struct member of struct mptcp_sock, which
points to the first subflow of msk. Save 'sk' in mptcp_storage, and verify
it with 'first' in verify_msk().

v5:
 - Use ASSERT_EQ() instead of a manual comparison + log (Andrii).

Signed-off-by: Geliang Tang <[email protected]>
Signed-off-by: Mat Martineau <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Acked-by: Matthieu Baerts <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

1 files changed, 5 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
index 33cafc619913..59f08d6d1d53 100644
--- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
+++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
@@ -14,7 +14,9 @@
 struct mptcp_storage {
 	__u32 invoked;
 	__u32 is_mptcp;
+	struct sock *sk;
 	__u32 token;
+	struct sock *first;
 	char ca_name[TCP_CA_NAME_MAX];
 };
 
@@ -80,6 +82,9 @@ static int verify_msk(int map_fd, int client_fd, __u32 token)
 	if (!ASSERT_EQ(val.token, token, "unexpected token"))
 		err++;
 
+	if (!ASSERT_EQ(val.first, val.sk, "unexpected first"))
+		err++;
+
 	if (!ASSERT_STRNEQ(val.ca_name, ca_name, TCP_CA_NAME_MAX, "unexpected ca_name"))
 		err++;