[PATCH bpf V8 2/7] selftests/bpf: Add counters to xdp_hw_metadata

From: Jesper Dangaard Brouer
Date: Wed Apr 12 2023 - 08:45:17 EST


Add counters for skipped, failed and redirected packets.
The xdp_hw_metadata program only redirects UDP port 9091.
This helps users to quickly identify then packets are
skipped and identify failures of bpf_xdp_adjust_meta.

Signed-off-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
---
.../testing/selftests/bpf/progs/xdp_hw_metadata.c | 15 +++++++++++++--
tools/testing/selftests/bpf/xdp_hw_metadata.c | 4 +++-
2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c b/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
index b0104763405a..a07ef7534013 100644
--- a/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
+++ b/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
@@ -25,6 +25,10 @@ struct {
__type(value, __u32);
} xsk SEC(".maps");

+volatile __u64 pkts_skip = 0;
+volatile __u64 pkts_fail = 0;
+volatile __u64 pkts_redir = 0;
+
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,
@@ -59,16 +63,21 @@ int rx(struct xdp_md *ctx)
udp = NULL;
}

- if (!udp)
+ if (!udp) {
+ pkts_skip++;
return XDP_PASS;
+ }

/* Forwarding UDP:9091 to AF_XDP */
- if (udp->dest != bpf_htons(9091))
+ if (udp->dest != bpf_htons(9091)) {
+ pkts_skip++;
return XDP_PASS;
+ }

ret = bpf_xdp_adjust_meta(ctx, -(int)sizeof(struct xdp_meta));
if (ret != 0) {
bpf_printk("bpf_xdp_adjust_meta returned %d", ret);
+ pkts_fail++;
return XDP_PASS;
}

@@ -78,6 +87,7 @@ int rx(struct xdp_md *ctx)

if (meta + 1 > data) {
bpf_printk("bpf_xdp_adjust_meta doesn't appear to work");
+ pkts_fail++;
return XDP_PASS;
}

@@ -91,6 +101,7 @@ int rx(struct xdp_md *ctx)
else
meta->rx_hash = 0; /* Used by AF_XDP as not avail signal */

+ pkts_redir++;
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 1c8acb68b977..3b942ef7297b 100644
--- a/tools/testing/selftests/bpf/xdp_hw_metadata.c
+++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c
@@ -212,7 +212,9 @@ static int verify_metadata(struct xsk *rx_xsk, int rxq, int server_fd)
while (true) {
errno = 0;
ret = poll(fds, rxq + 1, 1000);
- printf("poll: %d (%d)\n", ret, errno);
+ printf("poll: %d (%d) skip=%llu fail=%llu redir=%llu\n",
+ ret, errno, bpf_obj->bss->pkts_skip,
+ bpf_obj->bss->pkts_fail, bpf_obj->bss->pkts_redir);
if (ret < 0)
break;
if (ret == 0)