[PATCH V2 net-next 01/14] tcp: Add clean acked data hook

[Saeed Mahameed <saeedm@mellanox.com>]

From: Ilya Lesokhin <ilyal@mellanox.com>

Called when a TCP segment is acknowledged.
Could be used by application protocols who hold additional
metadata associated with the stream data.

This is required by TLS device offload to release
metadata associated with acknowledged TLS records.

Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Aviad Yehezkel <aviadye@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
---
 include/net/inet_connection_sock.h | 2 ++
 include/net/tcp.h                  | 5 +++++
 net/ipv4/tcp.c                     | 5 +++++
 net/ipv4/tcp_input.c               | 6 ++++++
 4 files changed, 18 insertions(+)

diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
index b68fea022a82..2ab6667275df 100644
--- a/include/net/inet_connection_sock.h
+++ b/include/net/inet_connection_sock.h
@@ -77,6 +77,7 @@ struct inet_connection_sock_af_ops {
  * @icsk_af_ops		   Operations which are AF_INET{4,6} specific
  * @icsk_ulp_ops	   Pluggable ULP control hook
  * @icsk_ulp_data	   ULP private data
+ * @icsk_clean_acked	   Clean acked data hook
  * @icsk_listen_portaddr_node	hash to the portaddr listener hashtable
  * @icsk_ca_state:	   Congestion control state
  * @icsk_retransmits:	   Number of unrecovered [RTO] timeouts
@@ -102,6 +103,7 @@ struct inet_connection_sock {
 	const struct inet_connection_sock_af_ops *icsk_af_ops;
 	const struct tcp_ulp_ops  *icsk_ulp_ops;
 	void			  *icsk_ulp_data;
+	void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq);
 	struct hlist_node         icsk_listen_portaddr_node;
 	unsigned int		  (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
 	__u8			  icsk_ca_state:6,
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 9c9b3768b350..dba03b205680 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2101,4 +2101,9 @@ static inline bool tcp_bpf_ca_needs_ecn(struct sock *sk)
 #if IS_ENABLED(CONFIG_SMC)
 extern struct static_key_false tcp_have_smc;
 #endif
+
+#if IS_ENABLED(CONFIG_TLS_DEVICE)
+extern struct static_key_false clean_acked_data_enabled;
+#endif
+
 #endif	/* _TCP_H */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index e553f84bde83..70056bb760d2 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -297,6 +297,11 @@ DEFINE_STATIC_KEY_FALSE(tcp_have_smc);
 EXPORT_SYMBOL(tcp_have_smc);
 #endif
 
+#if IS_ENABLED(CONFIG_TLS_DEVICE)
+DEFINE_STATIC_KEY_FALSE(clean_acked_data_enabled);
+EXPORT_SYMBOL_GPL(clean_acked_data_enabled);
+#endif
+
 /*
  * Current number of TCP sockets.
  */
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 451ef3012636..21f5c647f4be 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3542,6 +3542,12 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
 	if (after(ack, prior_snd_una)) {
 		flag |= FLAG_SND_UNA_ADVANCED;
 		icsk->icsk_retransmits = 0;
+
+#if IS_ENABLED(CONFIG_TLS_DEVICE)
+		if (static_branch_unlikely(&clean_acked_data_enabled))
+			if (icsk->icsk_clean_acked)
+				icsk->icsk_clean_acked(sk, ack);
+#endif
 	}
 
 	prior_fack = tcp_is_sack(tp) ? tcp_highest_sack_seq(tp) : tp->snd_una;
-- 
2.14.3