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

[Rao Shoaib <rao.shoaib@oracle.com>]

On 03/19/2018 07:44 PM, Saeed Mahameed wrote:
> 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 ++
>   net/ipv4/tcp_input.c               | 2 ++
>   2 files changed, 4 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/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
> index 451ef3012636..9854ecae7245 100644
> --- a/net/ipv4/tcp_input.c
> +++ b/net/ipv4/tcp_input.c
> @@ -3542,6 +3542,8 @@ 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 (icsk->icsk_clean_acked)
> +			icsk->icsk_clean_acked(sk, ack);
>   	}
>   
>   	prior_fack = tcp_is_sack(tp) ? tcp_highest_sack_seq(tp) : tp->snd_una;
Per Dave we are not allowed to use function pointers any more, so why 
extend their use. I implemented a similar callback for my changes but in 
my use case I need to call the meta data update function even when the 
packet does not ack any new data or has no payload. Is it possible to 
move this to say tcp_data_queue() ?

Thanks,

Shoaib