[PATCH bpf-next v4 21/21] selftests/bpf: check checksum state in xdp_metadata

[Larysa Zaremba <larysa.zaremba@xxxxxxxxx>]

Verify, whether kfunc in xdp_metadata test correctly returns partial
checksum status and offsets.

Signed-off-by: Larysa Zaremba <larysa.zaremba@xxxxxxxxx>
---
 .../selftests/bpf/prog_tests/xdp_metadata.c   | 30 +++++++++++++++++++
 .../selftests/bpf/progs/xdp_metadata.c        |  6 ++++
 2 files changed, 36 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
index 61e1b073a4b2..6c3dd90b271b 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
@@ -46,6 +46,7 @@
 
 #define XDP_RSS_TYPE_L4 BIT(3)
 #define VLAN_VID_MASK 0xfff
+#define XDP_CHECKSUM_PARTIAL BIT(3)
 
 struct xsk {
 	void *umem_area;
@@ -167,6 +168,32 @@ static void refill_rx(struct xsk *xsk, __u64 addr)
 	}
 }
 
+struct partial_csum_info {
+	__u16 csum_start;
+	__u16 csum_offset;
+};
+
+static bool assert_checksum_ok(struct xdp_meta *meta)
+{
+	struct partial_csum_info *info;
+	u32 csum_start, csum_offset;
+
+	if (!ASSERT_EQ(meta->rx_csum_status, XDP_CHECKSUM_PARTIAL,
+		       "rx_csum_status"))
+		return false;
+
+	csum_start = sizeof(struct ethhdr) + sizeof(struct iphdr);
+	csum_offset = offsetof(struct udphdr, check);
+	info = (void *)&meta->rx_csum_info;
+
+	if (!ASSERT_EQ(info->csum_start, csum_start, "rx csum_start"))
+		return false;
+	if (!ASSERT_EQ(info->csum_offset, csum_offset, "rx csum_offset"))
+		return false;
+
+	return true;
+}
+
 static int verify_xsk_metadata(struct xsk *xsk)
 {
 	const struct xdp_desc *rx_desc;
@@ -228,6 +255,9 @@ static int verify_xsk_metadata(struct xsk *xsk)
 	if (!ASSERT_EQ(meta->rx_vlan_proto, VLAN_PID, "rx_vlan_proto"))
 		return -1;
 
+	if (!assert_checksum_ok(meta))
+		return -1;
+
 	xsk_ring_cons__release(&xsk->rx, 1);
 	refill_rx(xsk, comp_addr);
 
diff --git a/tools/testing/selftests/bpf/progs/xdp_metadata.c b/tools/testing/selftests/bpf/progs/xdp_metadata.c
index f3db5cef4726..c99f7f4eb37d 100644
--- a/tools/testing/selftests/bpf/progs/xdp_metadata.c
+++ b/tools/testing/selftests/bpf/progs/xdp_metadata.c
@@ -26,6 +26,9 @@ extern int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, __u32 *hash,
 extern int bpf_xdp_metadata_rx_vlan_tag(const struct xdp_md *ctx,
 					__u16 *vlan_tci,
 					__be16 *vlan_proto) __ksym;
+extern int bpf_xdp_metadata_rx_csum(const struct xdp_md *ctx,
+				    enum xdp_csum_status *csum_status,
+				    union xdp_csum_info *csum_info) __ksym;
 
 SEC("xdp")
 int rx(struct xdp_md *ctx)
@@ -63,6 +66,9 @@ int rx(struct xdp_md *ctx)
 	bpf_xdp_metadata_rx_vlan_tag(ctx, &meta->rx_vlan_tci,
 				     &meta->rx_vlan_proto);
 
+	bpf_xdp_metadata_rx_csum(ctx, &meta->rx_csum_status,
+				 (void *)&meta->rx_csum_info);
+
 	return bpf_redirect_map(&xsk, ctx->rx_queue_index, XDP_PASS);
 }
 
-- 
2.41.0