[PATCH 03/11] nvmet-tcp: define listen socket ops

[Geliang Tang]

From: Geliang Tang <tanggeliang at kylinos.cn>

To support MPTCP on the target side, the listen socket needs to pass
IPPROTO_MPTCP to sock_create() for MPTCP ports, and use MPTCP-specific
setsockopt functions.

This patch adds struct nvmet_tcp_proto_ops to hold listen socket protocol
operations (protocol, set_reuseaddr, set_nodelay, set_priority). A TCP
version is defined and used for TCP ports.

v2:
 - use trtype instead of tsas (Hannes).

v3:
 - check mptcp protocol from disc_addr.trtype instead of passing a
parameter (Hannes).

v4:
 - check CONFIG_MPTCP.

v5:
 - define nvmet_tcp_proto struct.
 - add a pointer to this structure in nvmet_tcp_port.

v6:
 - split nvmet_tcp_proto struct into two structs, nvmet_tcp_proto and
nvmet_tcp_proto_ops, one for the accept socket, the other for the liston
socket.
 - add a pointer to nvmet_tcp_proto struct in nvmet_tcp_queue.

Cc: Hannes Reinecke <hare at suse.de>
Cc: John Meneghini <jmeneghi at redhat.com>
Cc: Randy Jennings <randyj at purestorage.com>
Cc: Nilay Shroff <nilay at linux.ibm.com>
Co-developed-by: zhenwei pi <zhenwei.pi at linux.dev>
Signed-off-by: zhenwei pi <zhenwei.pi at linux.dev>
Co-developed-by: Hui Zhu <zhuhui at kylinos.cn>
Signed-off-by: Hui Zhu <zhuhui at kylinos.cn>
Co-developed-by: Gang Yan <yangang at kylinos.cn>
Signed-off-by: Gang Yan <yangang at kylinos.cn>
Signed-off-by: Geliang Tang <tanggeliang at kylinos.cn>
---
 drivers/nvme/target/tcp.c | 30 ++++++++++++++++++++++++++----
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 16f153a9772b..83fe001fc619 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -2087,8 +2087,23 @@ static void nvmet_tcp_listen_data_ready(struct sock *sk)
 	read_unlock_bh(&sk->sk_callback_lock);
 }
 
+struct nvmet_tcp_proto_ops {
+	int			protocol;
+	void (*set_reuseaddr)(struct sock *sk);
+	void (*set_nodelay)(struct sock *sk);
+	void (*set_priority)(struct sock *sk, u32 priority);
+};
+
+static const struct nvmet_tcp_proto_ops nvmet_tcp_proto_ops = {
+	.protocol	= IPPROTO_TCP,
+	.set_reuseaddr	= sock_set_reuseaddr,
+	.set_nodelay	= tcp_sock_set_nodelay,
+	.set_priority	= sock_set_priority,
+};
+
 static int nvmet_tcp_add_port(struct nvmet_port *nport)
 {
+	const struct nvmet_tcp_proto_ops *ops;
 	struct nvmet_tcp_port *port;
 	__kernel_sa_family_t af;
 	int ret;
@@ -2111,6 +2126,13 @@ static int nvmet_tcp_add_port(struct nvmet_port *nport)
 		goto err_port;
 	}
 
+	if (nport->disc_addr.trtype == NVMF_TRTYPE_TCP) {
+		ops = &nvmet_tcp_proto_ops;
+	} else {
+		ret = -EINVAL;
+		goto err_port;
+	}
+
 	ret = inet_pton_with_scope(&init_net, af, nport->disc_addr.traddr,
 			nport->disc_addr.trsvcid, &port->addr);
 	if (ret) {
@@ -2125,7 +2147,7 @@ static int nvmet_tcp_add_port(struct nvmet_port *nport)
 		port->nport->inline_data_size = NVMET_TCP_DEF_INLINE_DATA_SIZE;
 
 	ret = sock_create(port->addr.ss_family, SOCK_STREAM,
-				IPPROTO_TCP, &port->sock);
+				ops->protocol, &port->sock);
 	if (ret) {
 		pr_err("failed to create a socket\n");
 		goto err_port;
@@ -2134,10 +2156,10 @@ static int nvmet_tcp_add_port(struct nvmet_port *nport)
 	port->sock->sk->sk_user_data = port;
 	port->data_ready = port->sock->sk->sk_data_ready;
 	port->sock->sk->sk_data_ready = nvmet_tcp_listen_data_ready;
-	sock_set_reuseaddr(port->sock->sk);
-	tcp_sock_set_nodelay(port->sock->sk);
+	ops->set_reuseaddr(port->sock->sk);
+	ops->set_nodelay(port->sock->sk);
 	if (so_priority > 0)
-		sock_set_priority(port->sock->sk, so_priority);
+		ops->set_priority(port->sock->sk, so_priority);
 
 	ret = kernel_bind(port->sock, (struct sockaddr_unsized *)&port->addr,
 			sizeof(port->addr));
-- 
2.53.0