From 80bea9acabb7690042f8efe25f208ffc67032aac Mon Sep 17 00:00:00 2001 From: Magnus Karlsson Date: Wed, 11 Jan 2023 10:35:23 +0100 Subject: [PATCH] selftests/xsk: add test when some packets are XDP_DROPed Add a new test where some of the packets are not passed to the AF_XDP socket and instead get a XDP_DROP verdict. This is important as it tests the recycling mechanism of the buffer pool. If a packet is not sent to the AF_XDP socket, the buffer the packet resides in is instead recycled so it can be used again without the round-trip to user space. The test introduces a new XDP program that drops every other packet. Signed-off-by: Magnus Karlsson Acked-by: Maciej Fijalkowski Link: https://lore.kernel.org/r/20230111093526.11682-13-magnus.karlsson@gmail.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/progs/xsk_xdp_progs.c | 11 ++++++++ tools/testing/selftests/bpf/xskxceiver.c | 31 +++++++++++++++++++++++ tools/testing/selftests/bpf/xskxceiver.h | 1 + 3 files changed, 43 insertions(+) diff --git a/tools/testing/selftests/bpf/progs/xsk_xdp_progs.c b/tools/testing/selftests/bpf/progs/xsk_xdp_progs.c index 6981768..744a01d 100644 --- a/tools/testing/selftests/bpf/progs/xsk_xdp_progs.c +++ b/tools/testing/selftests/bpf/progs/xsk_xdp_progs.c @@ -11,9 +11,20 @@ struct { __uint(value_size, sizeof(int)); } xsk SEC(".maps"); +static unsigned int idx; + SEC("xdp") int xsk_def_prog(struct xdp_md *xdp) { return bpf_redirect_map(&xsk, 0, XDP_DROP); } +SEC("xdp") int xsk_xdp_drop(struct xdp_md *xdp) +{ + /* Drop every other packet */ + if (idx++ % 2) + return XDP_DROP; + + return bpf_redirect_map(&xsk, 0, XDP_DROP); +} + char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/xskxceiver.c b/tools/testing/selftests/bpf/xskxceiver.c index d691002..a33f11b 100644 --- a/tools/testing/selftests/bpf/xskxceiver.c +++ b/tools/testing/selftests/bpf/xskxceiver.c @@ -1646,6 +1646,34 @@ static void testapp_invalid_desc(struct test_spec *test) pkt_stream_restore_default(test); } +static void testapp_xdp_drop(struct test_spec *test) +{ + struct ifobject *ifobj = test->ifobj_rx; + int err; + + test_spec_set_name(test, "XDP_DROP_HALF"); + xsk_detach_xdp_program(ifobj->ifindex, ifobj->xdp_flags); + err = xsk_attach_xdp_program(ifobj->xdp_progs->progs.xsk_xdp_drop, ifobj->ifindex, + ifobj->xdp_flags); + if (err) { + printf("Error attaching XDP_DROP program\n"); + test->fail = true; + return; + } + + pkt_stream_receive_half(test); + testapp_validate_traffic(test); + + pkt_stream_restore_default(test); + xsk_detach_xdp_program(ifobj->ifindex, ifobj->xdp_flags); + err = xsk_attach_xdp_program(ifobj->xdp_progs->progs.xsk_def_prog, ifobj->ifindex, + ifobj->xdp_flags); + if (err) { + printf("Error restoring default XDP program\n"); + exit_with_error(-err); + } +} + static int xsk_load_xdp_programs(struct ifobject *ifobj) { ifobj->xdp_progs = xsk_xdp_progs__open_and_load(); @@ -1796,6 +1824,9 @@ static void run_pkt_test(struct test_spec *test, enum test_mode mode, enum test_ case TEST_TYPE_HEADROOM: testapp_headroom(test); break; + case TEST_TYPE_XDP_DROP_HALF: + testapp_xdp_drop(test); + break; default: break; } diff --git a/tools/testing/selftests/bpf/xskxceiver.h b/tools/testing/selftests/bpf/xskxceiver.h index 70b3e5d..a4daa51 100644 --- a/tools/testing/selftests/bpf/xskxceiver.h +++ b/tools/testing/selftests/bpf/xskxceiver.h @@ -87,6 +87,7 @@ enum test_type { TEST_TYPE_STATS_RX_FULL, TEST_TYPE_STATS_FILL_EMPTY, TEST_TYPE_BPF_RES, + TEST_TYPE_XDP_DROP_HALF, TEST_TYPE_MAX }; -- 2.7.4