net/tls: partially revert fix transition through disconnect with close

Looks like we were slightly overzealous with the shutdown()
cleanup. Even though the sock->sk_state can reach CLOSED again,
socket->state will not got back to SS_UNCONNECTED once
connections is ESTABLISHED. Meaning we will see EISCONN if
we try to reconnect, and EINVAL if we try to listen.

Only listen sockets can be shutdown() and reused, but since
ESTABLISHED sockets can never be re-connected() or used for
listen() we don't need to try to clean up the ULP state early.

Fixes: 32857cf ("net/tls: fix transition through disconnect with close")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/tls-offload.rst

@@ -524,9 +524,3 @@ Redirects leak clear text
 
 In the RX direction, if segment has already been decrypted by the device
 and it gets redirected or mirrored - clear text will be transmitted out.
-
-shutdown() doesn't clear TLS state
-----------------------------------
-
-shutdown() system call allows for a TLS socket to be reused as a different
-connection. Offload doesn't currently handle that.

include/net/tls.h

@@ -290,8 +290,6 @@ struct tls_context {
 
 	struct list_head list;
 	refcount_t refcount;
-
-	struct work_struct gc;
 };
 
 enum tls_offload_ctx_dir {

net/tls/tls_main.c

@@ -261,33 +261,6 @@ void tls_ctx_free(struct tls_context *ctx)
 	kfree(ctx);
 }
 
-static void tls_ctx_free_deferred(struct work_struct *gc)
-{
-	struct tls_context *ctx = container_of(gc, struct tls_context, gc);
-
-	/* Ensure any remaining work items are completed. The sk will
-	 * already have lost its tls_ctx reference by the time we get
-	 * here so no xmit operation will actually be performed.
-	 */
-	if (ctx->tx_conf == TLS_SW) {
-		tls_sw_cancel_work_tx(ctx);
-		tls_sw_free_ctx_tx(ctx);
-	}
-
-	if (ctx->rx_conf == TLS_SW) {
-		tls_sw_strparser_done(ctx);
-		tls_sw_free_ctx_rx(ctx);
-	}
-
-	tls_ctx_free(ctx);
-}
-
-static void tls_ctx_free_wq(struct tls_context *ctx)
-{
-	INIT_WORK(&ctx->gc, tls_ctx_free_deferred);
-	schedule_work(&ctx->gc);
-}
-
 static void tls_sk_proto_cleanup(struct sock *sk,
 				 struct tls_context *ctx, long timeo)
 {
@@ -315,29 +288,6 @@ static void tls_sk_proto_cleanup(struct sock *sk,
 #endif
 }
 
-static void tls_sk_proto_unhash(struct sock *sk)
-{
-	struct inet_connection_sock *icsk = inet_csk(sk);
-	long timeo = sock_sndtimeo(sk, 0);
-	struct tls_context *ctx;
-
-	if (unlikely(!icsk->icsk_ulp_data)) {
-		if (sk->sk_prot->unhash)
-			sk->sk_prot->unhash(sk);
-	}
-
-	ctx = tls_get_ctx(sk);
-	tls_sk_proto_cleanup(sk, ctx, timeo);
-	write_lock_bh(&sk->sk_callback_lock);
-	icsk->icsk_ulp_data = NULL;
-	sk->sk_prot = ctx->sk_proto;
-	write_unlock_bh(&sk->sk_callback_lock);
-
-	if (ctx->sk_proto->unhash)
-		ctx->sk_proto->unhash(sk);
-	tls_ctx_free_wq(ctx);
-}
-
 static void tls_sk_proto_close(struct sock *sk, long timeout)
 {
 	struct inet_connection_sock *icsk = inet_csk(sk);
@@ -786,7 +736,6 @@ static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
 	prot[TLS_BASE][TLS_BASE].setsockopt	= tls_setsockopt;
 	prot[TLS_BASE][TLS_BASE].getsockopt	= tls_getsockopt;
 	prot[TLS_BASE][TLS_BASE].close		= tls_sk_proto_close;
-	prot[TLS_BASE][TLS_BASE].unhash		= tls_sk_proto_unhash;
 
 	prot[TLS_SW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
 	prot[TLS_SW][TLS_BASE].sendmsg		= tls_sw_sendmsg;
@@ -804,20 +753,16 @@ static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
 
 #ifdef CONFIG_TLS_DEVICE
 	prot[TLS_HW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
-	prot[TLS_HW][TLS_BASE].unhash		= base->unhash;
 	prot[TLS_HW][TLS_BASE].sendmsg		= tls_device_sendmsg;
 	prot[TLS_HW][TLS_BASE].sendpage		= tls_device_sendpage;
 
 	prot[TLS_HW][TLS_SW] = prot[TLS_BASE][TLS_SW];
-	prot[TLS_HW][TLS_SW].unhash		= base->unhash;
 	prot[TLS_HW][TLS_SW].sendmsg		= tls_device_sendmsg;
 	prot[TLS_HW][TLS_SW].sendpage		= tls_device_sendpage;
 
 	prot[TLS_BASE][TLS_HW] = prot[TLS_BASE][TLS_SW];
-	prot[TLS_BASE][TLS_HW].unhash		= base->unhash;
 
 	prot[TLS_SW][TLS_HW] = prot[TLS_SW][TLS_SW];
-	prot[TLS_SW][TLS_HW].unhash		= base->unhash;
 
 	prot[TLS_HW][TLS_HW] = prot[TLS_HW][TLS_SW];
 #endif