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 <toke@xxxxxxxxxx>
---
.../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 9926b07e38c8..a50971c6cf4a 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:
--
2.35.1
