On Fri, Sep 11, 2020 at 8:02 AM Nicolas Rybowski
<nicolas.rybowski@xxxxxxxxxxxx> wrote:
>
> This patch adds a base for MPTCP specific tests.
>
> It is currently limited to the is_mptcp field in case of plain TCP
> connection because for the moment there is no easy way to get the subflow
> sk from a msk in userspace. This implies that we cannot lookup the
> sk_storage attached to the subflow sk in the sockops program.
>
> Acked-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
> Signed-off-by: Nicolas Rybowski <nicolas.rybowski@xxxxxxxxxxxx>
Acked-by: Song Liu <songliubraving@xxxxxx>
With some nitpicks below.
> ---
>
> Notes:
> v1 -> v2:
> - new patch: mandatory selftests (Alexei)
>
[...]
> int timeout_ms);
> diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> new file mode 100644
> index 000000000000..0e65d64868e9
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> @@ -0,0 +1,119 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <test_progs.h>
> +#include "cgroup_helpers.h"
> +#include "network_helpers.h"
> +
> +struct mptcp_storage {
> + __u32 invoked;
> + __u32 is_mptcp;
> +};
> +
> +static int verify_sk(int map_fd, int client_fd, const char *msg, __u32 is_mptcp)
> +{
> + int err = 0, cfd = client_fd;
> + struct mptcp_storage val;
> +
> + /* Currently there is no easy way to get back the subflow sk from the MPTCP
> + * sk, thus we cannot access here the sk_storage associated to the subflow
> + * sk. Also, there is no sk_storage associated with the MPTCP sk since it
> + * does not trigger sockops events.
> + * We silently pass this situation at the moment.
> + */
> + if (is_mptcp == 1)
> + return 0;
> +
> + if (CHECK_FAIL(bpf_map_lookup_elem(map_fd, &cfd, &val) < 0)) {
> + perror("Failed to read socket storage");
Maybe simplify this with CHECK(), which contains a customized error message?
Same for some other calls.
> + return -1;
> + }
> +
> + if (val.invoked != 1) {
> + log_err("%s: unexpected invoked count %d != %d",
> + msg, val.invoked, 1);
> + err++;
> + }
> +
> + if (val.is_mptcp != is_mptcp) {
> + log_err("%s: unexpected bpf_tcp_sock.is_mptcp %d != %d",
> + msg, val.is_mptcp, is_mptcp);
> + err++;
> + }
> +
> + return err;
> +}
> +
> +static int run_test(int cgroup_fd, int server_fd, bool is_mptcp)
[...]
> +
> + client_fd = is_mptcp ? connect_to_mptcp_fd(server_fd, 0) :
> + connect_to_fd(server_fd, 0);
> + if (client_fd < 0) {
> + err = -1;
> + goto close_client_fd;
This should be "goto close_bpf_object;", and we don't really need the label
close_client_fd.
> + }
> +
> + err += is_mptcp ? verify_sk(map_fd, client_fd, "MPTCP subflow socket", 1) :
It doesn't really change the logic, but I guess we only need "err = xxx"?
> + verify_sk(map_fd, client_fd, "plain TCP socket", 0);
> +
> +close_client_fd:
> + close(client_fd);
> +
> +close_bpf_object:
> + bpf_object__close(obj);
> + return err;
> +}
> +
