[PATCH v1 bpf-next] selftest: bpf: Relax TCPOPT_WINDOW validation in test_tcp_custom_syncookie.c.

[Kuniyuki Iwashima <kuniyu@amazon.com>]

The custom syncookie test expects TCPOPT_WINDOW to be 7 based on the
kernel’s behaviour at the time, but the upcoming series [0] will bump
it to 10.

Let's relax the test to allow any valid TCPOPT_WINDOW value in the
range 1–14.

Link: https://lore.kernel.org/netdev/20250513193919.1089692-1-edumazet@google.com/ #[0]
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 tools/testing/selftests/bpf/progs/test_tcp_custom_syncookie.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/progs/test_tcp_custom_syncookie.c b/tools/testing/selftests/bpf/progs/test_tcp_custom_syncookie.c
index eb5cca1fce16..7d5293de1952 100644
--- a/tools/testing/selftests/bpf/progs/test_tcp_custom_syncookie.c
+++ b/tools/testing/selftests/bpf/progs/test_tcp_custom_syncookie.c
@@ -294,7 +294,9 @@ static int tcp_validate_sysctl(struct tcp_syncookie *ctx)
 	    (ctx->ipv6 && ctx->attrs.mss != MSS_LOCAL_IPV6))
 		goto err;
 
-	if (!ctx->attrs.wscale_ok || ctx->attrs.snd_wscale != 7)
+	if (!ctx->attrs.wscale_ok ||
+	    !ctx->attrs.snd_wscale ||
+	    ctx->attrs.snd_wscale >= BPF_SYNCOOKIE_WSCALE_MASK)
 		goto err;
 
 	if (!ctx->attrs.tstamp_ok)
-- 
2.49.0