Re: [PATCH 05/18] net/tls: implement ->read_sock()

[Sagi Grimberg <sagi@grimberg.me>]

> Implement ->read_sock() function for use with nvme-tcp.
> 
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> Cc: Boris Pismenny <boris.pismenny@gmail.com>
> ---
>   net/tls/tls.h      |  2 ++
>   net/tls/tls_main.c |  2 ++
>   net/tls/tls_sw.c   | 71 ++++++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 75 insertions(+)
> 
> diff --git a/net/tls/tls.h b/net/tls/tls.h
> index 804c3880d028..a5bf3a9ce142 100644
> --- a/net/tls/tls.h
> +++ b/net/tls/tls.h
> @@ -113,6 +113,8 @@ bool tls_sw_sock_is_readable(struct sock *sk);
>   ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
>   			   struct pipe_inode_info *pipe,
>   			   size_t len, unsigned int flags);
> +int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc,
> +		     sk_read_actor_t read_actor);
>   
>   int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
>   int tls_device_sendpage(struct sock *sk, struct page *page,
> diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
> index 3735cb00905d..9b097f2902f6 100644
> --- a/net/tls/tls_main.c
> +++ b/net/tls/tls_main.c
> @@ -934,9 +934,11 @@ static void build_proto_ops(struct proto_ops ops[TLS_NUM_CONFIG][TLS_NUM_CONFIG]
>   
>   	ops[TLS_BASE][TLS_SW  ] = ops[TLS_BASE][TLS_BASE];
>   	ops[TLS_BASE][TLS_SW  ].splice_read	= tls_sw_splice_read;
> +	ops[TLS_BASE][TLS_SW  ].read_sock	= tls_sw_read_sock;
>   
>   	ops[TLS_SW  ][TLS_SW  ] = ops[TLS_SW  ][TLS_BASE];
>   	ops[TLS_SW  ][TLS_SW  ].splice_read	= tls_sw_splice_read;
> +	ops[TLS_SW  ][TLS_SW  ].read_sock	= tls_sw_read_sock;
>   
>   #ifdef CONFIG_TLS_DEVICE
>   	ops[TLS_HW  ][TLS_BASE] = ops[TLS_BASE][TLS_BASE];
> diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
> index 782d3701b86f..77d57066daf4 100644
> --- a/net/tls/tls_sw.c
> +++ b/net/tls/tls_sw.c
> @@ -2210,6 +2210,77 @@ ssize_t tls_sw_splice_read(struct socket *sock,  loff_t *ppos,
>   	goto splice_read_end;
>   }
>   
> +int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc,
> +		     sk_read_actor_t read_actor)
> +{
> +	struct tls_context *tls_ctx = tls_get_ctx(sk);
> +	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
> +	struct strp_msg *rxm = NULL;
> +	struct tls_msg *tlm;
> +	struct sk_buff *skb;
> +	ssize_t copied = 0;
> +	int err, used;
> +
> +	if (!skb_queue_empty(&ctx->rx_list)) {
> +		skb = __skb_dequeue(&ctx->rx_list);
> +	} else {
> +		struct tls_decrypt_arg darg;
> +
> +		err = tls_rx_rec_wait(sk, NULL, true, true);
> +		if (err <= 0)
> +			return err;
> +
> +		memset(&darg.inargs, 0, sizeof(darg.inargs));
> +
> +		err = tls_rx_one_record(sk, NULL, &darg);
> +		if (err < 0) {
> +			tls_err_abort(sk, -EBADMSG);
> +			return err;
> +		}
> +
> +		tls_rx_rec_done(ctx);
> +		skb = darg.skb;
> +	}
> +
> +	do {
> +		rxm = strp_msg(skb);
> +		tlm = tls_msg(skb);
> +
> +		/* read_sock does not support reading control messages */
> +		if (tlm->control != TLS_RECORD_TYPE_DATA) {
> +			err = -EINVAL;
> +			goto read_sock_requeue;

In the general case, this could just pass in the skb to recv_actor
and have it access the tlm and decide what to do with it...
(will require moving tls_msg() to include/net/strparser.h)

I agree that for nvme-tcp this would not have anything useful
other than breaking the connection and re-establish it later...