selftests/xsk: add xdp populate metadata test

Add a new test in copy-mode for testing the copying of metadata from the
buffer in kernel-space to user-space. This is accomplished by adding a
new XDP program and using the bss map to store a counter that is written
to the metadata field. This counter is incremented for every packet so
that the number becomes unique and should be the same as the payload. It
is store in the bss so the value can be reset between runs.

The XDP program populates the metadata and the userspace program checks
the value stored in the metadata field against the payload using the new
is_metadata_correct() function. To turn this verification on or off, add
a new parameter (use_metadata) to the ifobject structure.

Signed-off-by: Tushar Vyavahare <tushar.vyavahare@intel.com>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230320102705.306187-1-tushar.vyavahare@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/xskxceiver.h b/tools/testing/selftests/bpf/xskxceiver.h
index 3e8ec7d8ec32..bdb4efedf3a9 100644
--- a/tools/testing/selftests/bpf/xskxceiver.h
+++ b/tools/testing/selftests/bpf/xskxceiver.h
@@ -88,6 +88,7 @@ enum test_type {
 	TEST_TYPE_STATS_FILL_EMPTY,
 	TEST_TYPE_BPF_RES,
 	TEST_TYPE_XDP_DROP_HALF,
+	TEST_TYPE_XDP_METADATA_COUNT,
 	TEST_TYPE_MAX
 };
 
@@ -158,6 +159,7 @@ struct ifobject {
 	bool use_fill_ring;
 	bool release_rx;
 	bool shared_umem;
+	bool use_metadata;
 	u8 dst_mac[ETH_ALEN];
 	u8 src_mac[ETH_ALEN];
 };