Commit 0735627d authored by Jörn-Thorben Hinz's avatar Jörn-Thorben Hinz Committed by Alexei Starovoitov
Browse files

selftests/bpf: Test an incomplete BPF CC 



Test whether a TCP CC implemented in BPF providing neither cong_avoid()
nor cong_control() is correctly rejected. This check solely depends on
tcp_register_congestion_control() now, which is invoked during
bpf_map__attach_struct_ops().

Signed-off-by: default avatarJörn-Thorben Hinz <jthinz@mailbox.tu-berlin.de>
Link: https://lore.kernel.org/r/20220622191227.898118-5-jthinz@mailbox.tu-berlin.de


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 6e945d57

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

+22 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include "bpf_tcp_nogpl.skel.h"

#include "bpf_dctcp_release.skel.h"

#include "tcp_ca_write_sk_pacing.skel.h"

#include "tcp_ca_incompl_cong_ops.skel.h"



#ifndef ENOTSUPP

#define ENOTSUPP 524
@@ -339,6 +340,25 @@ static void test_write_sk_pacing(void) 
	tcp_ca_write_sk_pacing__destroy(skel);

}



static void test_incompl_cong_ops(void)

{

	struct tcp_ca_incompl_cong_ops *skel;

	struct bpf_link *link;



	skel = tcp_ca_incompl_cong_ops__open_and_load();

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

		return;



	/* That cong_avoid() and cong_control() are missing is only reported at

	 * this point:

	 */

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

	ASSERT_ERR_PTR(link, "attach_struct_ops");



	bpf_link__destroy(link);

	tcp_ca_incompl_cong_ops__destroy(skel);

}



void test_bpf_tcp_ca(void)

{

	if (test__start_subtest("dctcp"))
@@ -353,4 +373,6 @@ void test_bpf_tcp_ca(void) 
		test_rel_setsockopt();

	if (test__start_subtest("write_sk_pacing"))

		test_write_sk_pacing();

	if (test__start_subtest("incompl_cong_ops"))

		test_incompl_cong_ops();

}

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

0 → 100644
+35 −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";



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

{

	return (struct tcp_sock *)sk;

}



SEC("struct_ops/incompl_cong_ops_ssthresh")

__u32 BPF_PROG(incompl_cong_ops_ssthresh, struct sock *sk)

{

	return tcp_sk(sk)->snd_ssthresh;

}



SEC("struct_ops/incompl_cong_ops_undo_cwnd")

__u32 BPF_PROG(incompl_cong_ops_undo_cwnd, struct sock *sk)

{

	return tcp_sk(sk)->snd_cwnd;

}



SEC(".struct_ops")

struct tcp_congestion_ops incompl_cong_ops = {

	/* Intentionally leaving out any of the required cong_avoid() and

	 * cong_control() here.

	 */

	.ssthresh = (void *)incompl_cong_ops_ssthresh,

	.undo_cwnd = (void *)incompl_cong_ops_undo_cwnd,

	.name = "bpf_incompl_ops",

};