Commit 2c7e33f1 authored by KaFai Wan's avatar KaFai Wan Committed by Martin KaFai Lau
Browse files

selftests/bpf: Verify bpf-tcp-cc rejects TCP_NODELAY 



Add a bpf_tcp_ca selftest for the TCP_NODELAY restriction in
bpf-tcp-cc.

Update bpf_cubic to exercise init() and cwnd_event_tx_start(),
and check that both callbacks reject bpf_setsockopt(TCP_NODELAY)
with -EOPNOTSUPP.

Signed-off-by: default avatarKaFai Wan <kafai.wan@linux.dev>
Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20260421155804.135786-5-kafai.wan@linux.dev
parent 52b6b533

tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c

+4 −0
Original line number Diff line number Diff line
@@ -112,6 +112,10 @@ static void test_cubic(void) 


	ASSERT_EQ(cubic_skel->bss->bpf_cubic_acked_called, 1, "pkts_acked called");



	ASSERT_TRUE(cubic_skel->bss->nodelay_init_reject, "init reject nodelay option");

	ASSERT_TRUE(cubic_skel->bss->nodelay_cwnd_event_tx_start_reject,

		    "cwnd_event_tx_start reject nodelay option");



	bpf_link__destroy(link);

	bpf_cubic__destroy(cubic_skel);

}

tools/testing/selftests/bpf/progs/bpf_cubic.c

+14 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 


#include "bpf_tracing_net.h"

#include <bpf/bpf_tracing.h>

#include <errno.h>



char _license[] SEC("license") = "GPL";
@@ -170,10 +171,18 @@ static void bictcp_hystart_reset(struct sock *sk) 
	ca->sample_cnt = 0;

}



bool nodelay_init_reject = false;

bool nodelay_cwnd_event_tx_start_reject = false;



SEC("struct_ops")

void BPF_PROG(bpf_cubic_init, struct sock *sk)

{

	struct bpf_bictcp *ca = inet_csk_ca(sk);

	int true_val = 1, ret;



	ret = bpf_setsockopt(sk, SOL_TCP, TCP_NODELAY, &true_val, sizeof(true_val));

	if (ret == -EOPNOTSUPP)

		nodelay_init_reject = true;



	bictcp_reset(ca);
@@ -189,8 +198,13 @@ void BPF_PROG(bpf_cubic_cwnd_event_tx_start, struct sock *sk) 
{

	struct bpf_bictcp *ca = inet_csk_ca(sk);

	__u32 now = tcp_jiffies32;

	int true_val = 1, ret;

	__s32 delta;



	ret = bpf_setsockopt(sk, SOL_TCP, TCP_NODELAY, &true_val, sizeof(true_val));

	if (ret == -EOPNOTSUPP)

		nodelay_cwnd_event_tx_start_reject = true;



	delta = now - tcp_sk(sk)->lsndtime;



	/* We were application limited (idle) for a while.