net/tls: implement ->read_sock()

Implement ->read_sock() function for use with nvme-tcp.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Cc: Boris Pismenny <boris.pismenny@gmail.com>
Link: https://lore.kernel.org/r/20230726191556.41714-7-hare@suse.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

net/tls/tls.h

@@ -110,6 +110,8 @@ 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);
 void tls_device_splice_eof(struct socket *sock);

net/tls/tls_main.c

@@ -962,10 +962,12 @@ 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  ].poll		= tls_sk_poll;
+	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  ].poll		= tls_sk_poll;
+	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];

net/tls/tls_sw.c

@@ -2202,6 +2202,105 @@ 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 tls_prot_info *prot = &tls_ctx->prot_info;
+	struct strp_msg *rxm = NULL;
+	struct sk_buff *skb = NULL;
+	struct sk_psock *psock;
+	size_t flushed_at = 0;
+	bool released = true;
+	struct tls_msg *tlm;
+	ssize_t copied = 0;
+	ssize_t decrypted;
+	int err, used;
+
+	psock = sk_psock_get(sk);
+	if (psock) {
+		sk_psock_put(sk, psock);
+		return -EINVAL;
+	}
+	err = tls_rx_reader_acquire(sk, ctx, true);
+	if (err < 0)
+		return err;
+
+	/* If crypto failed the connection is broken */
+	err = ctx->async_wait.err;
+	if (err)
+		goto read_sock_end;
+
+	decrypted = 0;
+	do {
+		if (!skb_queue_empty(&ctx->rx_list)) {
+			skb = __skb_dequeue(&ctx->rx_list);
+			rxm = strp_msg(skb);
+			tlm = tls_msg(skb);
+		} else {
+			struct tls_decrypt_arg darg;
+			int to_decrypt;
+
+			err = tls_rx_rec_wait(sk, NULL, true, released);
+			if (err <= 0)
+				goto read_sock_end;
+
+			memset(&darg.inargs, 0, sizeof(darg.inargs));
+
+			rxm = strp_msg(tls_strp_msg(ctx));
+			tlm = tls_msg(tls_strp_msg(ctx));
+
+			to_decrypt = rxm->full_len - prot->overhead_size;
+
+			err = tls_rx_one_record(sk, NULL, &darg);
+			if (err < 0) {
+				tls_err_abort(sk, -EBADMSG);
+				goto read_sock_end;
+			}
+
+			released = tls_read_flush_backlog(sk, prot, rxm->full_len, to_decrypt,
+							  decrypted, &flushed_at);
+			skb = darg.skb;
+			decrypted += rxm->full_len;
+
+			tls_rx_rec_done(ctx);
+		}
+
+		/* read_sock does not support reading control messages */
+		if (tlm->control != TLS_RECORD_TYPE_DATA) {
+			err = -EINVAL;
+			goto read_sock_requeue;
+		}
+
+		used = read_actor(desc, skb, rxm->offset, rxm->full_len);
+		if (used <= 0) {
+			if (!copied)
+				err = used;
+			goto read_sock_requeue;
+		}
+		copied += used;
+		if (used < rxm->full_len) {
+			rxm->offset += used;
+			rxm->full_len -= used;
+			if (!desc->count)
+				goto read_sock_requeue;
+		} else {
+			consume_skb(skb);
+			if (!desc->count)
+				skb = NULL;
+		}
+	} while (skb);
+
+read_sock_end:
+	tls_rx_reader_release(sk, ctx);
+	return copied ? : err;
+
+read_sock_requeue:
+	__skb_queue_head(&ctx->rx_list, skb);
+	goto read_sock_end;
+}
+
 bool tls_sw_sock_is_readable(struct sock *sk)
 {
 	struct tls_context *tls_ctx = tls_get_ctx(sk);