Re: [PATCH bpf-next v1] selftests/bpf: Improve connect_force_port test reliability

[Yonghong Song <yonghong.song@linux.dev>]

On 3/11/26 11:20 PM, Jiayuan Chen wrote:
> From: Jiayuan Chen <jiayuan.chen@shopee.com>
>
> No functional changes.

This is not true as you mentioned below.

>
> The connect_force_port test can fail intermittently because the
> hardcoded server ports (60123/60124) may already be in use by other
> tests or processes in CI environments [1].
>
> Fix this by using dynamically assigned ports (port 0) for start_server
> and propagating the actual port to the BPF programs at runtime via
> skel->bss->port. Convert the test from the legacy bpf_object__open_file
> loading model to the skeleton (skel) pattern, which provides direct
> access to BPF global variables without introducing maps or other
> mechanisms.

I suggest you have two patches:
   . patch 1: fix port issue
   . patch 2: improve code from bpf_object__*() to skel based.
     patch 2 is optional.

>
> Test:
>
>    ./test_progs -a connect_force_port -v
>
>    test_v4:PASS:skel4_open_and_load 0 nsec
>    attach_progs:PASS:attach connect 0 nsec
>    attach_progs:PASS:attach getpeername 0 nsec
>    attach_progs:PASS:attach getsockname 0 nsec
>    run_tests:PASS:start_server tcp 0 nsec
>    run_tests:PASS:get_socket_local_port 0 nsec
>    run_tests:PASS:connect_to_fd 0 nsec
>    run_tests:PASS:verify_ports 0 nsec
>    run_tests:PASS:start_server udp 0 nsec
>    run_tests:PASS:get_socket_local_port 0 nsec
>    run_tests:PASS:connect_to_fd 0 nsec
>    run_tests:PASS:verify_ports 0 nsec
>    test_v6:PASS:skel6_open_and_load 0 nsec
>    attach_progs:PASS:attach connect 0 nsec
>    attach_progs:PASS:attach getpeername 0 nsec
>    attach_progs:PASS:attach getsockname 0 nsec
>    run_tests:PASS:start_server tcp 0 nsec
>    run_tests:PASS:get_socket_local_port 0 nsec
>    run_tests:PASS:connect_to_fd 0 nsec
>    run_tests:PASS:verify_ports 0 nsec
>    run_tests:PASS:start_server udp 0 nsec
>    run_tests:PASS:get_socket_local_port 0 nsec
>    run_tests:PASS:connect_to_fd 0 nsec
>    run_tests:PASS:verify_ports 0 nsec
>    #80      connect_force_port:OK
>    Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED
>
> [1] https://github.com/kernel-patches/bpf/actions/runs/22697676317/job/65808536038
>
> Cc: Jiayuan Chen <jiayuan.chen@linux.dev>
> Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com>
> ---
>   .../bpf/prog_tests/connect_force_port.c       | 190 +++++++++---------
>   .../selftests/bpf/progs/connect_force_port4.c |  10 +-
>   .../selftests/bpf/progs/connect_force_port6.c |  10 +-
>   3 files changed, 108 insertions(+), 102 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/connect_force_port.c b/tools/testing/selftests/bpf/prog_tests/connect_force_port.c
> index 24d553109f8dd..3e62f9b9f1d94 100644
> --- a/tools/testing/selftests/bpf/prog_tests/connect_force_port.c
> +++ b/tools/testing/selftests/bpf/prog_tests/connect_force_port.c
> @@ -3,6 +3,8 @@
>   #include <test_progs.h>
>   #include "cgroup_helpers.h"
>   #include "network_helpers.h"
> +#include "connect_force_port4.skel.h"
> +#include "connect_force_port6.skel.h"
>   
>   static int verify_ports(int family, int fd,
>   			__u16 expected_local, __u16 expected_peer)
> @@ -46,122 +48,122 @@ static int verify_ports(int family, int fd,
>   	return 0;
>   }
>   
>
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