On Tue, Dec 06, 2022 at 10:08:23AM +0100, Magnus Karlsson wrote:
> From: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
>
> 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 <magnus.karlsson@xxxxxxxxx>
> ---
> tools/testing/selftests/bpf/Makefile | 2 +-
> .../selftests/bpf/progs/xsk_xdp_drop.c | 25 ++++++++++
> tools/testing/selftests/bpf/xskxceiver.c | 48 +++++++++++++++++--
> tools/testing/selftests/bpf/xskxceiver.h | 3 ++
> 4 files changed, 72 insertions(+), 6 deletions(-)
> create mode 100644 tools/testing/selftests/bpf/progs/xsk_xdp_drop.c
>
> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> index 42e15b5a34a7..77ef8a8e6db4 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -240,7 +240,7 @@ $(OUTPUT)/flow_dissector_load: $(TESTING_HELPERS)
> $(OUTPUT)/test_maps: $(TESTING_HELPERS)
> $(OUTPUT)/test_verifier: $(TESTING_HELPERS) $(CAP_HELPERS)
> $(OUTPUT)/xsk.o: $(BPFOBJ)
> -$(OUTPUT)/xskxceiver: $(OUTPUT)/xsk.o $(OUTPUT)/xsk_def_prog.skel.h
> +$(OUTPUT)/xskxceiver: $(OUTPUT)/xsk.o $(OUTPUT)/xsk_def_prog.skel.h $(OUTPUT)/xsk_xdp_drop.skel.h
>
> BPFTOOL ?= $(DEFAULT_BPFTOOL)
> $(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) \
> diff --git a/tools/testing/selftests/bpf/progs/xsk_xdp_drop.c b/tools/testing/selftests/bpf/progs/xsk_xdp_drop.c
> new file mode 100644
> index 000000000000..12a12b0d9fc1
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/xsk_xdp_drop.c
> @@ -0,0 +1,25 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2022 Intel */
> +
> +#include <linux/bpf.h>
> +#include <bpf/bpf_helpers.h>
> +
> +struct {
> + __uint(type, BPF_MAP_TYPE_XSKMAP);
> + __uint(max_entries, 1);
> + __uint(key_size, sizeof(int));
> + __uint(value_size, sizeof(int));
> +} xsk SEC(".maps");
> +
> +static unsigned int idx;
> +
> +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 0cda4e3f1871..522dc1d69c17 100644
> --- a/tools/testing/selftests/bpf/xskxceiver.c
> +++ b/tools/testing/selftests/bpf/xskxceiver.c
> @@ -1654,18 +1654,53 @@ static void testapp_invalid_desc(struct test_spec *test)
> pkt_stream_restore_default(test);
> }
>
> -static int xsk_load_xdp_program(struct ifobject *ifobj)
> +static void testapp_xdp_drop(struct test_spec *test)
> +{
> + struct ifobject *ifobj = test->ifobj_rx;
> + int err;
> +
> + test_spec_set_name(test, "XDP_CONSUMES_SOME_PACKETS");
XDP_DROP_ODD_PACKETS ?
> + xsk_detach_xdp_program(ifobj->ifindex, ifobj->xdp_flags);
> + err = xsk_attach_xdp_program(ifobj->xdp_drop->progs.xsk_xdp_drop, ifobj->ifindex,
> + ifobj->xdp_flags);
> + if (err) {
> + printf("Error attaching XDP_DROP program\n");
> + test->fail = true;
> + return;
> + }
> + ifobj->xskmap = ifobj->xdp_drop->maps.xsk;
> +
> + 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->def_prog->progs.xsk_def_prog, ifobj->ifindex,
> + ifobj->xdp_flags);
> + if (err) {
> + printf("Error restoring default XDP program\n");
> + exit_with_error(-err);
> + }
> + ifobj->xskmap = ifobj->def_prog->maps.xsk;
> +}
> +
> +static int xsk_load_xdp_programs(struct ifobject *ifobj)
> {
> ifobj->def_prog = xsk_def_prog__open_and_load();
> if (libbpf_get_error(ifobj->def_prog))
> return libbpf_get_error(ifobj->def_prog);
>
> + ifobj->xdp_drop = xsk_xdp_drop__open_and_load();
> + if (libbpf_get_error(ifobj->xdp_drop))
> + return libbpf_get_error(ifobj->xdp_drop);
> +
> return 0;
> }
>
> -static void xsk_unload_xdp_program(struct ifobject *ifobj)
> +static void xsk_unload_xdp_programs(struct ifobject *ifobj)
> {
> xsk_def_prog__destroy(ifobj->def_prog);
> + xsk_xdp_drop__destroy(ifobj->xdp_drop);
> }
>
> static void init_iface(struct ifobject *ifobj, const char *dst_mac, const char *src_mac,
> @@ -1692,7 +1727,7 @@ static void init_iface(struct ifobject *ifobj, const char *dst_mac, const char *
> if (!load_xdp)
> return;
>
> - err = xsk_load_xdp_program(ifobj);
> + err = xsk_load_xdp_programs(ifobj);
> if (err) {
> printf("Error loading XDP program\n");
> exit_with_error(err);
> @@ -1804,6 +1839,9 @@ 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_CONSUMES_PACKETS:
> + testapp_xdp_drop(test);
> + break;
> default:
> break;
> }
> @@ -1971,8 +2009,8 @@ int main(int argc, char **argv)
>
> pkt_stream_delete(tx_pkt_stream_default);
> pkt_stream_delete(rx_pkt_stream_default);
> - xsk_unload_xdp_program(ifobj_tx);
> - xsk_unload_xdp_program(ifobj_rx);
> + xsk_unload_xdp_programs(ifobj_tx);
> + xsk_unload_xdp_programs(ifobj_rx);
> ifobject_delete(ifobj_tx);
> ifobject_delete(ifobj_rx);
>
> diff --git a/tools/testing/selftests/bpf/xskxceiver.h b/tools/testing/selftests/bpf/xskxceiver.h
> index eb6355bcc143..3483ac240b2e 100644
> --- a/tools/testing/selftests/bpf/xskxceiver.h
> +++ b/tools/testing/selftests/bpf/xskxceiver.h
> @@ -6,6 +6,7 @@
> #define XSKXCEIVER_H_
>
> #include "xsk_def_prog.skel.h"
> +#include "xsk_xdp_drop.skel.h"
>
> #ifndef SOL_XDP
> #define SOL_XDP 283
> @@ -87,6 +88,7 @@ enum test_type {
> TEST_TYPE_STATS_RX_FULL,
> TEST_TYPE_STATS_FILL_EMPTY,
> TEST_TYPE_BPF_RES,
> + TEST_TYPE_XDP_CONSUMES_PACKETS,
> TEST_TYPE_MAX
> };
>
> @@ -141,6 +143,7 @@ struct ifobject {
> validation_func_t validation_func;
> struct pkt_stream *pkt_stream;
> struct xsk_def_prog *def_prog;
> + struct xsk_xdp_drop *xdp_drop;
Is this going to scale if we add plenty of XDP progs for testing?
> struct bpf_map *xskmap;
> int ifindex;
> u32 dst_ip;
> --
> 2.34.1
>
