The bpf_nf test allocs a ct, sets snat and dnat with random addr and port via bpf_ct_set_nat_info(), then looks the ct up and checks the reply tuple against what was set.
The port comes from bpf_get_prandom_u32() and can be 0. For bpf_ct_set_nat_info(), port 0 means "port not specified", so only the addr is mapped and the kernel keeps the original port. The check then compares that port with 0 and fails, which shows up as a flaky "Test for source natting" failure in CI [1][2]. Keep the random port in 1..65535 so it is always specified. [1] https://github.com/kernel-patches/bpf/actions/runs/33830002889/job/100893868791 [2] https://github.com/kernel-patches/bpf/actions/runs/33829976794/job/100893220999 Fixes: b06b45e82b59 ("selftests/bpf: add tests for bpf_ct_set_nat_info kfunc") Signed-off-by: Jiayuan Chen <[email protected]> --- tools/testing/selftests/bpf/progs/test_bpf_nf.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/bpf/progs/test_bpf_nf.c b/tools/testing/selftests/bpf/progs/test_bpf_nf.c index df43649ecb78..eda9b7bbab75 100644 --- a/tools/testing/selftests/bpf/progs/test_bpf_nf.c +++ b/tools/testing/selftests/bpf/progs/test_bpf_nf.c @@ -190,8 +190,8 @@ nf_ct_test(struct nf_conn *(*lookup_fn)(void *, struct bpf_sock_tuple *, u32, ct = alloc_fn(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4), &opts_def, sizeof(opts_def)); if (ct) { - __u16 sport = bpf_get_prandom_u32(); - __u16 dport = bpf_get_prandom_u32(); + __u16 sport = bpf_get_prandom_u32() % 65535 + 1; + __u16 dport = bpf_get_prandom_u32() % 65535 + 1; union nf_inet_addr saddr = {}; union nf_inet_addr daddr = {}; struct nf_conn *ct_ins; @@ -293,8 +293,8 @@ nf_ct_opts_new_test(struct nf_conn *(*lookup_fn)(void *, struct bpf_sock_tuple * ct = alloc_fn(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4), &opts_def, sizeof(opts_def)); if (ct) { - __u16 sport = bpf_get_prandom_u32(); - __u16 dport = bpf_get_prandom_u32(); + __u16 sport = bpf_get_prandom_u32() % 65535 + 1; + __u16 dport = bpf_get_prandom_u32() % 65535 + 1; union nf_inet_addr saddr = {}; union nf_inet_addr daddr = {}; struct nf_conn *ct_ins; -- 2.43.0
