Commit 6e945d57 authored by Jörn-Thorben Hinz's avatar Jörn-Thorben Hinz Committed by Alexei Starovoitov
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selftests/bpf: Test a BPF CC writing sk_pacing_* 



Test whether a TCP CC implemented in BPF is allowed to write
sk_pacing_rate and sk_pacing_status in struct sock. This is needed when
cong_control() is implemented and used.

Signed-off-by: default avatarJörn-Thorben Hinz <jthinz@mailbox.tu-berlin.de>
Link: https://lore.kernel.org/r/20220622191227.898118-4-jthinz@mailbox.tu-berlin.de


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 9f0265e9

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

+19 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include "bpf_cubic.skel.h"

#include "bpf_tcp_nogpl.skel.h"

#include "bpf_dctcp_release.skel.h"

#include "tcp_ca_write_sk_pacing.skel.h"



#ifndef ENOTSUPP

#define ENOTSUPP 524
@@ -322,6 +323,22 @@ static void test_rel_setsockopt(void) 
	bpf_dctcp_release__destroy(rel_skel);

}



static void test_write_sk_pacing(void)

{

	struct tcp_ca_write_sk_pacing *skel;

	struct bpf_link *link;



	skel = tcp_ca_write_sk_pacing__open_and_load();

	if (!ASSERT_OK_PTR(skel, "open_and_load"))

		return;



	link = bpf_map__attach_struct_ops(skel->maps.write_sk_pacing);

	ASSERT_OK_PTR(link, "attach_struct_ops");



	bpf_link__destroy(link);

	tcp_ca_write_sk_pacing__destroy(skel);

}



void test_bpf_tcp_ca(void)

{

	if (test__start_subtest("dctcp"))
@@ -334,4 +351,6 @@ void test_bpf_tcp_ca(void) 
		test_dctcp_fallback();

	if (test__start_subtest("rel_setsockopt"))

		test_rel_setsockopt();

	if (test__start_subtest("write_sk_pacing"))

		test_write_sk_pacing();

}

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

0 → 100644
+60 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



#include "vmlinux.h"



#include <bpf/bpf_helpers.h>

#include <bpf/bpf_tracing.h>



char _license[] SEC("license") = "GPL";



#define USEC_PER_SEC 1000000UL



#define min(a, b) ((a) < (b) ? (a) : (b))



static inline struct tcp_sock *tcp_sk(const struct sock *sk)

{

	return (struct tcp_sock *)sk;

}



SEC("struct_ops/write_sk_pacing_init")

void BPF_PROG(write_sk_pacing_init, struct sock *sk)

{

#ifdef ENABLE_ATOMICS_TESTS

	__sync_bool_compare_and_swap(&sk->sk_pacing_status, SK_PACING_NONE,

				     SK_PACING_NEEDED);

#else

	sk->sk_pacing_status = SK_PACING_NEEDED;

#endif

}



SEC("struct_ops/write_sk_pacing_cong_control")

void BPF_PROG(write_sk_pacing_cong_control, struct sock *sk,

	      const struct rate_sample *rs)

{

	const struct tcp_sock *tp = tcp_sk(sk);

	unsigned long rate =

		((tp->snd_cwnd * tp->mss_cache * USEC_PER_SEC) << 3) /

		(tp->srtt_us ?: 1U << 3);

	sk->sk_pacing_rate = min(rate, sk->sk_max_pacing_rate);

}



SEC("struct_ops/write_sk_pacing_ssthresh")

__u32 BPF_PROG(write_sk_pacing_ssthresh, struct sock *sk)

{

	return tcp_sk(sk)->snd_ssthresh;

}



SEC("struct_ops/write_sk_pacing_undo_cwnd")

__u32 BPF_PROG(write_sk_pacing_undo_cwnd, struct sock *sk)

{

	return tcp_sk(sk)->snd_cwnd;

}



SEC(".struct_ops")

struct tcp_congestion_ops write_sk_pacing = {

	.init = (void *)write_sk_pacing_init,

	.cong_control = (void *)write_sk_pacing_cong_control,

	.ssthresh = (void *)write_sk_pacing_ssthresh,

	.undo_cwnd = (void *)write_sk_pacing_undo_cwnd,

	.name = "bpf_w_sk_pacing",

};