[PATCH net 8/9] tls: fix replacing proto_ops

[Jakub Kicinski <kuba@kernel.org>]

We replace proto_ops whenever TLS is configured for RX. But our
replacement also overrides sendpage_locked, which will crash
unless TX is also configured. Similarly we plug both of those
in for TLS_HW (NIC crypto offload) even tho TLS_HW has a completely
different implementation for TX.

Last but not least we always plug in something based on inet_stream_ops
even though a few of the callbacks differ for IPv6 (getname, release,
bind).

Use a callback building method similar to what we do for struct proto.

Fixes: c46234ebb4d1 ("tls: RX path for ktls")
Fixes: d4ffb02dee2f ("net/tls: enable sk_msg redirect to tls socket egress")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 net/tls/tls_main.c | 47 +++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 40 insertions(+), 7 deletions(-)

diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index acfba9f1ba72..6bc2879ba637 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -61,7 +61,7 @@ static DEFINE_MUTEX(tcpv6_prot_mutex);
 static const struct proto *saved_tcpv4_prot;
 static DEFINE_MUTEX(tcpv4_prot_mutex);
 static struct proto tls_prots[TLS_NUM_PROTS][TLS_NUM_CONFIG][TLS_NUM_CONFIG];
-static struct proto_ops tls_sw_proto_ops;
+static struct proto_ops tls_proto_ops[TLS_NUM_PROTS][TLS_NUM_CONFIG][TLS_NUM_CONFIG];
 static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
 			 const struct proto *base);
 
@@ -71,6 +71,8 @@ void update_sk_prot(struct sock *sk, struct tls_context *ctx)
 
 	WRITE_ONCE(sk->sk_prot,
 		   &tls_prots[ip_ver][ctx->tx_conf][ctx->rx_conf]);
+	WRITE_ONCE(sk->sk_socket->ops,
+		   &tls_proto_ops[ip_ver][ctx->tx_conf][ctx->rx_conf]);
 }
 
 int wait_on_pending_writer(struct sock *sk, long *timeo)
@@ -669,8 +671,6 @@ static int do_tls_setsockopt_conf(struct sock *sk, sockptr_t optval,
 	if (tx) {
 		ctx->sk_write_space = sk->sk_write_space;
 		sk->sk_write_space = tls_write_space;
-	} else {
-		sk->sk_socket->ops = &tls_sw_proto_ops;
 	}
 	goto out;
 
@@ -728,6 +728,39 @@ struct tls_context *tls_ctx_create(struct sock *sk)
 	return ctx;
 }
 
+static void build_proto_ops(struct proto_ops ops[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
+			    const struct proto_ops *base)
+{
+	ops[TLS_BASE][TLS_BASE] = *base;
+
+	ops[TLS_SW  ][TLS_BASE] = ops[TLS_BASE][TLS_BASE];
+	ops[TLS_SW  ][TLS_BASE].sendpage_locked	= tls_sw_sendpage_locked;
+
+	ops[TLS_BASE][TLS_SW  ] = ops[TLS_BASE][TLS_BASE];
+	ops[TLS_BASE][TLS_SW  ].splice_read	= tls_sw_splice_read;
+
+	ops[TLS_SW  ][TLS_SW  ] = ops[TLS_SW  ][TLS_BASE];
+	ops[TLS_SW  ][TLS_SW  ].splice_read	= tls_sw_splice_read;
+
+#ifdef CONFIG_TLS_DEVICE
+	ops[TLS_HW  ][TLS_BASE] = ops[TLS_BASE][TLS_BASE];
+	ops[TLS_HW  ][TLS_BASE].sendpage_locked	= NULL;
+
+	ops[TLS_HW  ][TLS_SW  ] = ops[TLS_BASE][TLS_SW  ];
+	ops[TLS_HW  ][TLS_SW  ].sendpage_locked	= NULL;
+
+	ops[TLS_BASE][TLS_HW  ] = ops[TLS_BASE][TLS_SW  ];
+
+	ops[TLS_SW  ][TLS_HW  ] = ops[TLS_SW  ][TLS_SW  ];
+
+	ops[TLS_HW  ][TLS_HW  ] = ops[TLS_HW  ][TLS_SW  ];
+	ops[TLS_HW  ][TLS_HW  ].sendpage_locked	= NULL;
+#endif
+#ifdef CONFIG_TLS_TOE
+	ops[TLS_HW_RECORD][TLS_HW_RECORD] = *base;
+#endif
+}
+
 static void tls_build_proto(struct sock *sk)
 {
 	int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;
@@ -739,6 +772,8 @@ static void tls_build_proto(struct sock *sk)
 		mutex_lock(&tcpv6_prot_mutex);
 		if (likely(prot != saved_tcpv6_prot)) {
 			build_protos(tls_prots[TLSV6], prot);
+			build_proto_ops(tls_proto_ops[TLSV6],
+					sk->sk_socket->ops);
 			smp_store_release(&saved_tcpv6_prot, prot);
 		}
 		mutex_unlock(&tcpv6_prot_mutex);
@@ -749,6 +784,8 @@ static void tls_build_proto(struct sock *sk)
 		mutex_lock(&tcpv4_prot_mutex);
 		if (likely(prot != saved_tcpv4_prot)) {
 			build_protos(tls_prots[TLSV4], prot);
+			build_proto_ops(tls_proto_ops[TLSV4],
+					sk->sk_socket->ops);
 			smp_store_release(&saved_tcpv4_prot, prot);
 		}
 		mutex_unlock(&tcpv4_prot_mutex);
@@ -959,10 +996,6 @@ static int __init tls_register(void)
 	if (err)
 		return err;
 
-	tls_sw_proto_ops = inet_stream_ops;
-	tls_sw_proto_ops.splice_read = tls_sw_splice_read;
-	tls_sw_proto_ops.sendpage_locked   = tls_sw_sendpage_locked;
-
 	tls_device_init();
 	tcp_register_ulp(&tcp_tls_ulp_ops);
 
-- 
2.31.1