[RFC bpf-next 16/23] selftests/bpf: Add flags and new hints to xdp_hw_metadata

Larysa Zaremba
2023-08-24T19:34:30Z

Add hints added in the previous patches (VLAN tag and checksum)
to the xdp_hw_metadata program.

Also, to make metadata layout more straightforward, add flags field
to pass information about validity of every separate hint separately.

Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
---
.../selftests/bpf/progs/xdp_hw_metadata.c | 38 +++++++++--
tools/testing/selftests/bpf/xdp_hw_metadata.c | 67 +++++++++++++++++--
tools/testing/selftests/bpf/xdp_metadata.h | 34 +++++++++-
3 files changed, 126 insertions(+), 13 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c b/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
index 63d7de6c6bbb..95b17eaf8f05 100644
--- a/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
+++ b/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
@@ -20,6 +20,12 @@ 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_tci,
+ __be16 *vlan_proto) __ksym;
+extern int bpf_xdp_metadata_rx_csum(const struct xdp_md *ctx,
+ enum xdp_csum_status *csum_status,
+ __wsum *csum) __ksym;

SEC("xdp")
int rx(struct xdp_md *ctx)
@@ -84,15 +90,35 @@ int rx(struct xdp_md *ctx)
return XDP_PASS;
}

+ meta->hint_valid = 0;
+
+ meta->xdp_timestamp = bpf_ktime_get_tai_ns();
err = bpf_xdp_metadata_rx_timestamp(ctx, &meta->rx_timestamp);
- if (!err)
- meta->xdp_timestamp = bpf_ktime_get_tai_ns();
+ if (err)
+ meta->rx_timestamp_err = err;
+ else
+ meta->hint_valid |= XDP_META_FIELD_TS;
+
+ err = bpf_xdp_metadata_rx_hash(ctx, &meta->rx_hash,
+ &meta->rx_hash_type);
+ if (err)
+ meta->rx_hash_err = err;
else
- meta->rx_timestamp = 0; /* Used by AF_XDP as not avail signal */
+ meta->hint_valid |= XDP_META_FIELD_RSS;

- err = bpf_xdp_metadata_rx_hash(ctx, &meta->rx_hash, &meta->rx_hash_type);
- if (err < 0)
- meta->rx_hash_err = err; /* Used by AF_XDP as no hash signal */
+ err = bpf_xdp_metadata_rx_vlan_tag(ctx, &meta->rx_vlan_tci,
+ &meta->rx_vlan_proto);
+ if (err)
+ meta->rx_vlan_tag_err = err;
+ else
+ meta->hint_valid |= XDP_META_FIELD_VLAN_TAG;
+
+ err = bpf_xdp_metadata_rx_csum(ctx, &meta->rx_csum_status,
+ &meta->rx_csum);
+ if (err)
+ meta->rx_csum_err = err;
+ else
+ meta->hint_valid |= XDP_META_FIELD_CSUM;

__sync_add_and_fetch(&pkts_redir, 1);
return bpf_redirect_map(&xsk, ctx->rx_queue_index, XDP_PASS);
diff --git a/tools/testing/selftests/bpf/xdp_hw_metadata.c b/tools/testing/selftests/bpf/xdp_hw_metadata.c
index 613321eb84c1..7535baa7e7ef 100644
--- a/tools/testing/selftests/bpf/xdp_hw_metadata.c
+++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c
@@ -19,6 +19,9 @@
#include "xsk.h"

#include <error.h>
+#include <linux/kernel.h>
+#include <linux/bits.h>
+#include <linux/bitfield.h>
#include <linux/errqueue.h>
#include <linux/if_link.h>
#include <linux/net_tstamp.h>
@@ -150,21 +153,58 @@ static __u64 gettime(clockid_t clock_id)
return (__u64) t.tv_sec * NANOSEC_PER_SEC + t.tv_nsec;
}

+#define VLAN_PRIO_MASK GENMASK(15, 13) /* Priority Code Point */
+#define VLAN_DEI_MASK GENMASK(12, 12) /* Drop Eligible Indicator */
+#define VLAN_VID_MASK GENMASK(11, 0) /* VLAN Identifier */
+static void print_vlan_tci(__u16 tag)
+{
+ __u16 vlan_id = FIELD_GET(VLAN_VID_MASK, tag);
+ __u8 pcp = FIELD_GET(VLAN_PRIO_MASK, tag);
+ bool dei = FIELD_GET(VLAN_DEI_MASK, tag);
+
+ printf("PCP=%u, DEI=%d, VID=0x%X\n", pcp, dei, vlan_id);
+}
+
+#define XDP_CHECKSUM_VERIFIED BIT(0)
+#define XDP_CHECKSUM_COMPLETE BIT(1)
+
+struct partial_csum_info {
+ __u16 csum_start;
+ __u16 csum_offset;
+};
+
+static void print_csum_state(__u32 status, __u32 info)
+{
+ bool is_verified = status & XDP_CHECKSUM_VERIFIED;
+
+ printf("Checksum status: ");
+ if (status & ~(XDP_CHECKSUM_COMPLETE | XDP_CHECKSUM_VERIFIED))
+ printf("cannot be interpreted, status=0x%X\n", status);
+
+ if (status & XDP_CHECKSUM_COMPLETE)
+ printf("complete, checksum=0x%X%s", info,
+ is_verified ? ", " : "\n");
+
+ if (is_verified)
+ printf("outermost checksum is verified\n");
+}
+
static void verify_xdp_metadata(void *data, clockid_t clock_id)
{
struct xdp_meta *meta;

meta = data - sizeof(*meta);

- if (meta->rx_hash_err < 0)
- printf("No rx_hash err=%d\n", meta->rx_hash_err);
- else
+ if (meta->hint_valid & XDP_META_FIELD_RSS)
printf("rx_hash: 0x%X with RSS type:0x%X\n",
meta->rx_hash, meta->rx_hash_type);
+ else
+ printf("No rx_hash, err=%d\n", meta->rx_hash_err);
+
+ if (meta->hint_valid & XDP_META_FIELD_TS) {
+ printf("rx_timestamp: %llu (sec:%0.4f)\n", meta->rx_timestamp,
+ (double)meta->rx_timestamp / NANOSEC_PER_SEC);

- printf("rx_timestamp: %llu (sec:%0.4f)\n", meta->rx_timestamp,
- (double)meta->rx_timestamp / NANOSEC_PER_SEC);
- if (meta->rx_timestamp) {
__u64 usr_clock = gettime(clock_id);
__u64 xdp_clock = meta->xdp_timestamp;
__s64 delta_X = xdp_clock - meta->rx_timestamp;
@@ -179,8 +219,23 @@ static void verify_xdp_metadata(void *data, clockid_t clock_id)
usr_clock, (double)usr_clock / NANOSEC_PER_SEC,
(double)delta_X2U / NANOSEC_PER_SEC,
(double)delta_X2U / 1000);
+ } else {
+ printf("No rx_timestamp, err=%d\n", meta->rx_timestamp_err);
+ }
+
+ if (meta->hint_valid & XDP_META_FIELD_VLAN_TAG) {
+ printf("rx_vlan_proto: 0x%X\n", ntohs(meta->rx_vlan_proto));
+ printf("rx_vlan_tci: ");
+ print_vlan_tci(meta->rx_vlan_tci);
+ } else {
+ printf("No rx_vlan_tci or rx_vlan_proto, err=%d\n",
+ meta->rx_vlan_tag_err);
}

+ if (meta->hint_valid & XDP_META_FIELD_CSUM)
+ print_csum_state(meta->rx_csum_status, meta->rx_csum);
+ else
+ printf("Checksum was not checked, err=%d\n", meta->rx_csum_err);
}

static void verify_skb_metadata(int fd)
diff --git a/tools/testing/selftests/bpf/xdp_metadata.h b/tools/testing/selftests/bpf/xdp_metadata.h
index 6664893c2c77..0b749bfed2de 100644
--- a/tools/testing/selftests/bpf/xdp_metadata.h
+++ b/tools/testing/selftests/bpf/xdp_metadata.h
@@ -17,12 +17,44 @@
#define ETH_P_8021AD 0x88A8
#endif

+#ifndef BIT
+#define BIT(nr) (1 << (nr))
+#endif
+
+/* Non-existent checksum status */
+#define XDP_CHECKSUM_MAGIC BIT(2)
+
+enum xdp_meta_field {
+ XDP_META_FIELD_TS = BIT(0),
+ XDP_META_FIELD_RSS = BIT(1),
+ XDP_META_FIELD_VLAN_TAG = BIT(2),
+ XDP_META_FIELD_CSUM = BIT(3),
+};
+
struct xdp_meta {
- __u64 rx_timestamp;
+ union {
+ __u64 rx_timestamp;
+ __s32 rx_timestamp_err;
+ };
__u64 xdp_timestamp;
__u32 rx_hash;
union {
__u32 rx_hash_type;
__s32 rx_hash_err;
};
+ union {
+ struct {
+ __u16 rx_vlan_tci;
+ __be16 rx_vlan_proto;
+ };
+ __s32 rx_vlan_tag_err;
+ };
+ union {
+ struct {
+ __u32 rx_csum_status;
+ __wsum rx_csum;
+ };
+ __s32 rx_csum_err;
+ };
+ enum xdp_meta_field hint_valid;
};
--
2.41.0