Commit d8e8052e authored by Toke Høiland-Jørgensen's avatar Toke Høiland-Jørgensen Committed by Daniel Borkmann
Browse files

bpf/selftests: Test that kernel rejects a TCP CC with an invalid license 



This adds a selftest to check that the verifier rejects a TCP CC struct_ops
with a non-GPL license.

Signed-off-by: default avatarToke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210326100314.121853-2-toke@redhat.com
parent 12aa8a94

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

+44 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
#include <test_progs.h>

#include "bpf_dctcp.skel.h"

#include "bpf_cubic.skel.h"

#include "bpf_tcp_nogpl.skel.h"



#define min(a, b) ((a) < (b) ? (a) : (b))
@@ -227,10 +228,53 @@ static void test_dctcp(void) 
	bpf_dctcp__destroy(dctcp_skel);

}



static char *err_str;

static bool found;



static int libbpf_debug_print(enum libbpf_print_level level,

			      const char *format, va_list args)

{

	char *log_buf;



	if (level != LIBBPF_WARN ||

	    strcmp(format, "libbpf: \n%s\n")) {

		vprintf(format, args);

		return 0;

	}



	log_buf = va_arg(args, char *);

	if (!log_buf)

		goto out;

	if (err_str && strstr(log_buf, err_str) != NULL)

		found = true;

out:

	printf(format, log_buf);

	return 0;

}



static void test_invalid_license(void)

{

	libbpf_print_fn_t old_print_fn;

	struct bpf_tcp_nogpl *skel;



	err_str = "struct ops programs must have a GPL compatible license";

	found = false;

	old_print_fn = libbpf_set_print(libbpf_debug_print);



	skel = bpf_tcp_nogpl__open_and_load();

	ASSERT_NULL(skel, "bpf_tcp_nogpl");

	ASSERT_EQ(found, true, "expected_err_msg");



	bpf_tcp_nogpl__destroy(skel);

	libbpf_set_print(old_print_fn);

}



void test_bpf_tcp_ca(void)

{

	if (test__start_subtest("dctcp"))

		test_dctcp();

	if (test__start_subtest("cubic"))

		test_cubic();

	if (test__start_subtest("invalid_license"))

		test_invalid_license();

}

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

0 → 100644
+19 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



#include <linux/bpf.h>

#include <linux/types.h>

#include <bpf/bpf_helpers.h>

#include <bpf/bpf_tracing.h>

#include "bpf_tcp_helpers.h"



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



void BPF_STRUCT_OPS(nogpltcp_init, struct sock *sk)

{

}



SEC(".struct_ops")

struct tcp_congestion_ops bpf_nogpltcp = {

	.init           = (void *)nogpltcp_init,

	.name           = "bpf_nogpltcp",

};