[PATCH bpf-next v2 19/20] selftests/bpf: Check VLAN tag and proto in xdp_metadata

[Larysa Zaremba <larysa.zaremba@xxxxxxxxx>]

Verify, whether VLAN tag and proto are set correctly.

To simulate "stripped" VLAN tag on veth, send test packet from VLAN
interface.

Signed-off-by: Larysa Zaremba <larysa.zaremba@xxxxxxxxx>
---
 .../selftests/bpf/prog_tests/xdp_metadata.c   | 21 +++++++++++++++++--
 .../selftests/bpf/progs/xdp_metadata.c        |  4 ++++
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
index 53b32a641e8e..50ac9f570bc5 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
@@ -38,6 +38,13 @@
 #define TX_MAC "00:00:00:00:00:01"
 #define RX_MAC "00:00:00:00:00:02"
 
+#define VLAN_ID 59
+#define VLAN_ID_STR "59"
+#define VLAN_PROTO "802.1Q"
+#define VLAN_PID htons(ETH_P_8021Q)
+#define TX_NAME_VLAN TX_NAME "." VLAN_ID_STR
+#define RX_NAME_VLAN RX_NAME "." VLAN_ID_STR
+
 #define XDP_RSS_TYPE_L4 BIT(3)
 
 struct xsk {
@@ -215,6 +222,12 @@ static int verify_xsk_metadata(struct xsk *xsk)
 	if (!ASSERT_NEQ(meta->rx_hash_type & XDP_RSS_TYPE_L4, 0, "rx_hash_type"))
 		return -1;
 
+	if (!ASSERT_EQ(meta->rx_vlan_tag, VLAN_ID, "rx_vlan_tag"))
+		return -1;
+
+	if (!ASSERT_EQ(meta->rx_vlan_proto, VLAN_PID, "rx_vlan_proto"))
+		return -1;
+
 	xsk_ring_cons__release(&xsk->rx, 1);
 	refill_rx(xsk, comp_addr);
 
@@ -253,10 +266,14 @@ void test_xdp_metadata(void)
 
 	SYS(out, "ip link set dev " TX_NAME " address " TX_MAC);
 	SYS(out, "ip link set dev " TX_NAME " up");
-	SYS(out, "ip addr add " TX_ADDR "/" PREFIX_LEN " dev " TX_NAME);
+
+	SYS(out, "ip link add link " TX_NAME " " TX_NAME_VLAN
+		 " type vlan proto " VLAN_PROTO " id " VLAN_ID_STR);
+	SYS(out, "ip link set dev " TX_NAME_VLAN " up");
+	SYS(out, "ip addr add " TX_ADDR "/" PREFIX_LEN " dev " TX_NAME_VLAN);
 
 	/* Avoid ARP calls */
-	SYS(out, "ip -4 neigh add " RX_ADDR " lladdr " RX_MAC " dev " TX_NAME);
+	SYS(out, "ip -4 neigh add " RX_ADDR " lladdr " RX_MAC " dev " TX_NAME_VLAN);
 
 	set_netns(rx_netns);
 	SYS(out, "ip link set dev " RX_NAME " address " RX_MAC);
diff --git a/tools/testing/selftests/bpf/progs/xdp_metadata.c b/tools/testing/selftests/bpf/progs/xdp_metadata.c
index d151d406a123..382984a5d1c9 100644
--- a/tools/testing/selftests/bpf/progs/xdp_metadata.c
+++ b/tools/testing/selftests/bpf/progs/xdp_metadata.c
@@ -23,6 +23,9 @@ extern int bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx,
 					 __u64 *timestamp) __ksym;
 extern int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, __u32 *hash,
 				    enum xdp_rss_hash_type *rss_type) __ksym;
+extern int bpf_xdp_metadata_rx_vlan_tag(const struct xdp_md *ctx,
+					__u16 *vlan_tag,
+					__be16 *vlan_proto) __ksym;
 
 SEC("xdp")
 int rx(struct xdp_md *ctx)
@@ -57,6 +60,7 @@ int rx(struct xdp_md *ctx)
 		meta->rx_timestamp = 1;
 
 	bpf_xdp_metadata_rx_hash(ctx, &meta->rx_hash, &meta->rx_hash_type);
+	bpf_xdp_metadata_rx_vlan_tag(ctx, &meta->rx_vlan_tag, &meta->rx_vlan_proto);
 
 	return bpf_redirect_map(&xsk, ctx->rx_queue_index, XDP_PASS);
 }
-- 
2.41.0