[PATCH net-next 6/6] netdevsim: psp: count rx authentication and length errors

[Daniel Zahka <daniel.zahka@gmail.com>]

Now that netdevsim does psp parsing and aes-gcm decryption in rx, we
can report authentication and length errors in the psp stats api.

Assisted-by: Claude:claude-opus-4.7
Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com>
---
 drivers/net/netdevsim/netdevsim.h |  2 ++
 drivers/net/netdevsim/psp.c       | 11 ++++++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h
index 112fe1ee10bc..5f0f638ee893 100644
--- a/drivers/net/netdevsim/netdevsim.h
+++ b/drivers/net/netdevsim/netdevsim.h
@@ -118,6 +118,8 @@ struct netdevsim {
 	struct {
 		u64_stats_t rx_packets;
 		u64_stats_t rx_bytes;
+		u64_stats_t rx_auth_fail;
+		u64_stats_t rx_error;
 		u64_stats_t tx_packets;
 		u64_stats_t tx_bytes;
 		struct u64_stats_sync syncp;
diff --git a/drivers/net/netdevsim/psp.c b/drivers/net/netdevsim/psp.c
index 4945973d523d..053c01cc310d 100644
--- a/drivers/net/netdevsim/psp.c
+++ b/drivers/net/netdevsim/psp.c
@@ -207,8 +207,12 @@ bool nsim_psp_handle_rx(struct netdevsim *ns, struct sk_buff *skb)
 
 	psp_off = l3_hlen + sizeof(struct udphdr);
 	payload_len = skb->len - psp_off - PSP_HDR_SIZE - PSP_TRL_SIZE;
-	if (payload_len < 0)
+	if (payload_len < 0) {
+		u64_stats_update_begin(&ns->psp.syncp);
+		u64_stats_inc(&ns->psp.rx_error);
+		u64_stats_update_end(&ns->psp.syncp);
 		goto drop;
+	}
 
 	if (FIELD_GET(PSPHDR_CRYPT_OFFSET, psph->crypt_offset))
 		goto drop;
@@ -238,6 +242,9 @@ bool nsim_psp_handle_rx(struct netdevsim *ns, struct sk_buff *skb)
 			    payload_len, (u8 *)psph, PSP_HDR_SIZE,
 			    iv, authtag)) {
 		memzero_explicit(&ctx, sizeof(ctx));
+		u64_stats_update_begin(&ns->psp.syncp);
+		u64_stats_inc(&ns->psp.rx_auth_fail);
+		u64_stats_update_end(&ns->psp.syncp);
 		goto drop;
 	}
 	memzero_explicit(&ctx, sizeof(ctx));
@@ -346,6 +353,8 @@ static void nsim_get_stats(struct psp_dev *psd, struct psp_dev_stats *stats)
 		start = u64_stats_fetch_begin(&ns->psp.syncp);
 		stats->rx_bytes = u64_stats_read(&ns->psp.rx_bytes);
 		stats->rx_packets = u64_stats_read(&ns->psp.rx_packets);
+		stats->rx_auth_fail = u64_stats_read(&ns->psp.rx_auth_fail);
+		stats->rx_error = u64_stats_read(&ns->psp.rx_error);
 		stats->tx_bytes = u64_stats_read(&ns->psp.tx_bytes);
 		stats->tx_packets = u64_stats_read(&ns->psp.tx_packets);
 	} while (u64_stats_fetch_retry(&ns->psp.syncp, start));

-- 
2.52.0