From c09df4bd3a915079eec5e77160366225a28699a2 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Date: Thu, 10 Mar 2022 23:56:21 +0100 Subject: [PATCH] selftests/bpf: Add a test for maximum packet size in xdp_do_redirect MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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: Toke Høiland-Jørgensen Signed-off-by: Daniel Borkmann Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20220310225621.53374-2-toke@redhat.com --- .../selftests/bpf/prog_tests/xdp_do_redirect.c | 24 ++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c b/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c index 9926b07e..a50971c 100644 --- a/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c +++ b/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c @@ -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: -- 2.7.4