Commit c09df4bd authored by Toke Høiland-Jørgensen's avatar Toke Høiland-Jørgensen Committed by Daniel Borkmann
Browse files

selftests/bpf: Add a test for maximum packet size in xdp_do_redirect 



This adds an extra test to the xdp_do_redirect selftest for XDP live packet
mode, which verifies that the maximum permissible packet size is accepted
without any errors, and that a too big packet is correctly rejected.

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/20220310225621.53374-2-toke@redhat.com
parent b6f1f780

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

+24 −0
Original line number Diff line number Diff line
@@ -62,6 +62,28 @@ static int attach_tc_prog(struct bpf_tc_hook *hook, int fd) 
	return 0;

}



/* The maximum permissible size is: PAGE_SIZE - sizeof(struct xdp_page_head) -

 * sizeof(struct skb_shared_info) - XDP_PACKET_HEADROOM = 3368 bytes

 */

#define MAX_PKT_SIZE 3368

static void test_max_pkt_size(int fd)

{

	char data[MAX_PKT_SIZE + 1] = {};

	int err;

	DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts,

			    .data_in = &data,

			    .data_size_in = MAX_PKT_SIZE,

			    .flags = BPF_F_TEST_XDP_LIVE_FRAMES,

			    .repeat = 1,

		);

	err = bpf_prog_test_run_opts(fd, &opts);

	ASSERT_OK(err, "prog_run_max_size");



	opts.data_size_in += 1;

	err = bpf_prog_test_run_opts(fd, &opts);

	ASSERT_EQ(err, -EINVAL, "prog_run_too_big");

}



#define NUM_PKTS 10000

void test_xdp_do_redirect(void)

{
@@ -167,6 +189,8 @@ void test_xdp_do_redirect(void) 
	ASSERT_EQ(skel->bss->pkts_seen_zero, 2, "pkt_count_zero");

	ASSERT_EQ(skel->bss->pkts_seen_tc, NUM_PKTS - 2, "pkt_count_tc");



	test_max_pkt_size(bpf_program__fd(skel->progs.xdp_count_pkts));



out_tc:

	bpf_tc_hook_destroy(&tc_hook);

out: