From: Martin KaFai Lau Add a test to check that bpf_skb_check_mtu(BPF_MTU_CHK_SEGS) is rejected (-EINVAL) if skb->transport_header is not set. The test needs to lower the MTU of the loopback device. Thus, take this opportunity to run the test in a netns by adding "ns_" to the test name. The "serial_" prefix can then be removed. Signed-off-by: Martin KaFai Lau --- .../selftests/bpf/prog_tests/check_mtu.c | 23 ++++++++++++++++++- .../selftests/bpf/progs/test_check_mtu.c | 12 ++++++++++ 2 files changed, 34 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/prog_tests/check_mtu.c b/tools/testing/selftests/bpf/prog_tests/check_mtu.c index 2a9a30650350..65b4512967e7 100644 --- a/tools/testing/selftests/bpf/prog_tests/check_mtu.c +++ b/tools/testing/selftests/bpf/prog_tests/check_mtu.c @@ -153,6 +153,26 @@ static void test_check_mtu_run_tc(struct test_check_mtu *skel, ASSERT_EQ(mtu_result, mtu_expect, "MTU-compare-user"); } +static void test_chk_segs_flag(struct test_check_mtu *skel, __u32 mtu) +{ + int err, prog_fd = bpf_program__fd(skel->progs.tc_chk_segs_flag); + struct __sk_buff skb = { + .gso_size = 10, + }; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = &pkt_v4, + .data_size_in = sizeof(pkt_v4), + .ctx_in = &skb, + .ctx_size_in = sizeof(skb), + ); + + /* Lower the mtu to test the BPF_MTU_CHK_SEGS */ + SYS_NOFAIL("ip link set dev lo mtu 10"); + err = bpf_prog_test_run_opts(prog_fd, &topts); + SYS_NOFAIL("ip link set dev lo mtu %u", mtu); + ASSERT_OK(err, "test_run"); + ASSERT_EQ(topts.retval, BPF_OK, "retval"); +} static void test_check_mtu_tc(__u32 mtu, __u32 ifindex) { @@ -177,11 +197,12 @@ static void test_check_mtu_tc(__u32 mtu, __u32 ifindex) test_check_mtu_run_tc(skel, skel->progs.tc_minus_delta, mtu); test_check_mtu_run_tc(skel, skel->progs.tc_input_len, mtu); test_check_mtu_run_tc(skel, skel->progs.tc_input_len_exceed, mtu); + test_chk_segs_flag(skel, mtu); cleanup: test_check_mtu__destroy(skel); } -void serial_test_check_mtu(void) +void test_ns_check_mtu(void) { int mtu_lo; diff --git a/tools/testing/selftests/bpf/progs/test_check_mtu.c b/tools/testing/selftests/bpf/progs/test_check_mtu.c index 2ec1de11a3ae..7b6b2b342c1d 100644 --- a/tools/testing/selftests/bpf/progs/test_check_mtu.c +++ b/tools/testing/selftests/bpf/progs/test_check_mtu.c @@ -7,6 +7,7 @@ #include #include +#include char _license[] SEC("license") = "GPL"; @@ -288,3 +289,14 @@ int tc_input_len_exceed(struct __sk_buff *ctx) global_bpf_mtu_xdp = mtu_len; return retval; } + +SEC("tc") +int tc_chk_segs_flag(struct __sk_buff *ctx) +{ + __u32 mtu_len = 0; + int err; + + err = bpf_check_mtu(ctx, GLOBAL_USER_IFINDEX, &mtu_len, 0, BPF_MTU_CHK_SEGS); + + return err == -EINVAL ? BPF_OK : BPF_DROP; +} -- 2.47.3