[PATCH v4 3/4] nvmet-tcp: support IPv6 traffic class

[Geliang Tang]

From: Geliang Tang <tanggeliang at kylinos.cn>

Currently, nvmet-tcp only applies the received IPv4 TOS value when setting
up a queue socket, but does not handle the IPv6 traffic class.

Extend the queue socket setup to handle AF_INET6 sockets. Obtain the
traffic class from the IPv6 socket's rcv_flowinfo and apply it through
IPV6_TCLASS using do_sock_setsockopt().

Signed-off-by: Geliang Tang <tanggeliang at kylinos.cn>
---
 drivers/nvme/target/tcp.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 38b0c446ae89..ed413aa5601c 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -1737,6 +1737,22 @@ static int nvmet_tcp_sock_set_tos(struct sock *sk)
 	return 0;
 }
 
+static int nvmet_tcp_sock_set_tclass(struct sock *sk)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+	if (sk->sk_family == AF_INET6) {
+		int tclass = ip6_tclass(inet6_sk(sk)->rcv_flowinfo);
+
+		if (tclass > 0)
+			return do_sock_setsockopt(sk->sk_socket, false,
+						  SOL_IPV6, IPV6_TCLASS,
+						  KERNEL_SOCKPTR(&tclass),
+						  sizeof(tclass));
+	}
+#endif
+	return 0;
+}
+
 static int nvmet_tcp_set_queue_sock(struct nvmet_tcp_queue *queue)
 {
 	struct socket *sock = queue->sock;
@@ -1772,6 +1788,10 @@ static int nvmet_tcp_set_queue_sock(struct nvmet_tcp_queue *queue)
 	if (ret)
 		return ret;
 
+	ret = nvmet_tcp_sock_set_tclass(sock->sk);
+	if (ret)
+		return ret;
+
 	ret = 0;
 	write_lock_bh(&sock->sk->sk_callback_lock);
 	if (sock->sk->sk_state != TCP_ESTABLISHED) {
-- 
2.53.0