[PATCH v14 8/9] tls: device: add tracepoints for RX KeyUpdate path

[Rishikesh Jethwani <rjethwani@purestorage.com>]

Add three trace events covering the RX rekey state machine in
tls_device.c:

  tls_device_rekey_start     - rekey accepted; inflight=1 means old-key
                               data is still queued, dev_add deferred
  tls_device_rekey_reencrypt - old-key undo pass for a boundary record;
                               retry=1 means decrypted flags were flipped
  tls_device_rekey_done      - boundary crossed, old_aead_recv freed,
                               deferred dev_add issued if pending

Signed-off-by: Rishikesh Jethwani <rjethwani@purestorage.com>
---
 net/tls/tls_device.c | 10 ++++++
 net/tls/trace.h      | 79 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 89 insertions(+)

diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index 1c58cbd55ffb..f6072924bfb5 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -1234,6 +1234,9 @@ int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx)
 		if (ctx->old_key_reencrypted) {
 			struct sk_buff *frag_iter;
 
+			trace_tls_device_rekey_reencrypt(sk, rec_start_seq,
+							 ctx->rekey.old_nic_boundary,
+							 true);
 			skb->decrypted = !skb->decrypted;
 			skb_walk_frags(skb, frag_iter)
 				frag_iter->decrypted = !frag_iter->decrypted;
@@ -1253,12 +1256,17 @@ int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx)
 			/* For mixed records, first old key rencrypt and if
 			 * SW AEAD fails then retry with decrypted flags toggled
 			 */
+			trace_tls_device_rekey_reencrypt(sk, rec_start_seq,
+							 ctx->rekey.old_nic_boundary,
+							 false);
 			if (!is_decrypted)
 				ctx->old_key_reencrypted = 1;
 			return tls_device_reencrypt_old_key(sk, ctx,
 							   sw_ctx, tls_ctx);
 		}
 
+		trace_tls_device_rekey_done(sk, rec_start_seq,
+					    ctx->rekey.old_nic_boundary);
 		crypto_free_aead(ctx->rekey.old_aead_recv);
 		ctx->rekey.old_aead_recv = NULL;
 
@@ -1827,6 +1835,8 @@ int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx,
 				context->rekey.old_nic_boundary = rcv_nxt;
 				context->dev_add_pending = 1;
 			}
+			trace_tls_device_rekey_start(sk, copied_seq, rcv_nxt,
+						    before(copied_seq, rcv_nxt));
 		}
 	}
 
diff --git a/net/tls/trace.h b/net/tls/trace.h
index 2d8ce4ff3265..56fcf95c5aaf 100644
--- a/net/tls/trace.h
+++ b/net/tls/trace.h
@@ -192,6 +192,85 @@ TRACE_EVENT(tls_device_tx_resync_send,
 	)
 );
 
+TRACE_EVENT(tls_device_rekey_start,
+
+	TP_PROTO(struct sock *sk, u32 copied_seq, u32 nic_boundary,
+		 bool inflight),
+
+	TP_ARGS(sk, copied_seq, nic_boundary, inflight),
+
+	TP_STRUCT__entry(
+		__field(	struct sock *,	sk		)
+		__field(	u32,		copied_seq	)
+		__field(	u32,		nic_boundary	)
+		__field(	bool,		inflight	)
+	),
+
+	TP_fast_assign(
+		__entry->sk = sk;
+		__entry->copied_seq = copied_seq;
+		__entry->nic_boundary = nic_boundary;
+		__entry->inflight = inflight;
+	),
+
+	TP_printk(
+		"sk=%p copied_seq=%u nic_boundary=%u inflight=%d",
+		__entry->sk, __entry->copied_seq, __entry->nic_boundary,
+		__entry->inflight
+	)
+);
+
+TRACE_EVENT(tls_device_rekey_reencrypt,
+
+	TP_PROTO(struct sock *sk, u32 tcp_seq, u32 nic_boundary, bool retry),
+
+	TP_ARGS(sk, tcp_seq, nic_boundary, retry),
+
+	TP_STRUCT__entry(
+		__field(	struct sock *,	sk		)
+		__field(	u32,		tcp_seq		)
+		__field(	u32,		nic_boundary	)
+		__field(	bool,		retry		)
+	),
+
+	TP_fast_assign(
+		__entry->sk = sk;
+		__entry->tcp_seq = tcp_seq;
+		__entry->nic_boundary = nic_boundary;
+		__entry->retry = retry;
+	),
+
+	TP_printk(
+		"sk=%p tcp_seq=%u nic_boundary=%u retry=%d",
+		__entry->sk, __entry->tcp_seq, __entry->nic_boundary,
+		__entry->retry
+	)
+);
+
+TRACE_EVENT(tls_device_rekey_done,
+
+	TP_PROTO(struct sock *sk, u32 tcp_seq, u32 nic_boundary),
+
+	TP_ARGS(sk, tcp_seq, nic_boundary),
+
+	TP_STRUCT__entry(
+		__field(	struct sock *,	sk		)
+		__field(	u32,		tcp_seq		)
+		__field(	u32,		nic_boundary	)
+	),
+
+	TP_fast_assign(
+		__entry->sk = sk;
+		__entry->tcp_seq = tcp_seq;
+		__entry->nic_boundary = nic_boundary;
+	),
+
+	TP_printk(
+		"sk=%p tcp_seq=%u nic_boundary=%u",
+		__entry->sk, __entry->tcp_seq, __entry->nic_boundary
+	)
+);
+
 #endif /* _TLS_TRACE_H_ */
 
 #undef TRACE_INCLUDE_PATH
-- 
2.25.1