net/tls: don't arm strparser immediately in tls_set_sw_offload()

In tls_set_device_offload_rx() we prepare the software context
for RX fallback and proceed to add the connection to the device.
Unfortunately, software context prep includes arming strparser
so in case of a later error we have to release the socket lock
to call strp_done().

In preparation for not releasing the socket lock half way through
callbacks move arming strparser into a separate function.
Following patches will make use of that.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

include/net/tls.h

@@ -355,6 +355,7 @@ int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
 		  unsigned int optlen);
 
 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
+void tls_sw_strparser_arm(struct sock *sk, struct tls_context *ctx);
 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
 int tls_sw_sendpage(struct sock *sk, struct page *page,
 		    int offset, size_t size, int flags);

net/tls/tls_device.c

@@ -1045,6 +1045,7 @@ int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
 	rc = tls_set_sw_offload(sk, ctx, 0);
 	if (rc)
 		goto release_ctx;
+	tls_sw_strparser_arm(sk, ctx);
 
 	rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_RX,
 					     &ctx->crypto_recv.info,

net/tls/tls_main.c

@@ -526,6 +526,8 @@ static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval,
 		{
 #endif
 			rc = tls_set_sw_offload(sk, ctx, 1);
+			if (rc)
+				goto err_crypto_info;
 			conf = TLS_SW;
 		}
 	} else {
@@ -537,13 +539,13 @@ static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval,
 		{
 #endif
 			rc = tls_set_sw_offload(sk, ctx, 0);
+			if (rc)
+				goto err_crypto_info;
+			tls_sw_strparser_arm(sk, ctx);
 			conf = TLS_SW;
 		}
 	}
 
-	if (rc)
-		goto err_crypto_info;
-
 	if (tx)
 		ctx->tx_conf = conf;
 	else

net/tls/tls_sw.c

@@ -2160,6 +2160,18 @@ void tls_sw_write_space(struct sock *sk, struct tls_context *ctx)
 	}
 }
 
+void tls_sw_strparser_arm(struct sock *sk, struct tls_context *tls_ctx)
+{
+	struct tls_sw_context_rx *rx_ctx = tls_sw_ctx_rx(tls_ctx);
+
+	write_lock_bh(&sk->sk_callback_lock);
+	rx_ctx->saved_data_ready = sk->sk_data_ready;
+	sk->sk_data_ready = tls_data_ready;
+	write_unlock_bh(&sk->sk_callback_lock);
+
+	strp_check_rcv(&rx_ctx->strp);
+}
+
 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
 {
 	struct tls_context *tls_ctx = tls_get_ctx(sk);
@@ -2357,13 +2369,6 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
 		cb.parse_msg = tls_read_size;
 
 		strp_init(&sw_ctx_rx->strp, sk, &cb);
-
-		write_lock_bh(&sk->sk_callback_lock);
-		sw_ctx_rx->saved_data_ready = sk->sk_data_ready;
-		sk->sk_data_ready = tls_data_ready;
-		write_unlock_bh(&sk->sk_callback_lock);
-
-		strp_check_rcv(&sw_ctx_rx->strp);
 	}
 
 	goto out;