[PATCHv5 for-rc1 v5 2/8] RDMA/rxe: Support more rdma links in init_net

[Zhu Yanjun <yanjun.zhu@intel.com>]

From: Zhu Yanjun <yanjun.zhu@linux.dev>

In init_net, when several rdma links are created with the command "rdma
link add", newlink will check whether the udp port 4791 is listening or
not.
If not, creating a sock listening on udp port 4791. If yes, increasing the
reference count of the sock.

Tested-by: Rain River <rain.1986.08.12@gmail.com>
Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
---
 drivers/infiniband/sw/rxe/rxe.c     | 12 ++++++-
 drivers/infiniband/sw/rxe/rxe_net.c | 55 +++++++++++++++++++++--------
 drivers/infiniband/sw/rxe/rxe_net.h |  1 +
 3 files changed, 52 insertions(+), 16 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe.c b/drivers/infiniband/sw/rxe/rxe.c
index 64644cb0bb38..0ce6adb43cfc 100644
--- a/drivers/infiniband/sw/rxe/rxe.c
+++ b/drivers/infiniband/sw/rxe/rxe.c
@@ -8,6 +8,7 @@
 #include <net/addrconf.h>
 #include "rxe.h"
 #include "rxe_loc.h"
+#include "rxe_net.h"
 
 MODULE_AUTHOR("Bob Pearson, Frank Zago, John Groves, Kamal Heib");
 MODULE_DESCRIPTION("Soft RDMA transport");
@@ -205,14 +206,23 @@ static int rxe_newlink(const char *ibdev_name, struct net_device *ndev)
 	return err;
 }
 
-static struct rdma_link_ops rxe_link_ops = {
+struct rdma_link_ops rxe_link_ops = {
 	.type = "rxe",
 	.newlink = rxe_newlink,
 };
 
 static int __init rxe_module_init(void)
 {
+	int err;
+
 	rdma_link_register(&rxe_link_ops);
+
+	err = rxe_register_notifier();
+	if (err) {
+		pr_err("Failed to register netdev notifier\n");
+		return -1;
+	}
+
 	pr_info("loaded\n");
 	return 0;
 }
diff --git a/drivers/infiniband/sw/rxe/rxe_net.c b/drivers/infiniband/sw/rxe/rxe_net.c
index e02e1624bcf4..3ca92e062800 100644
--- a/drivers/infiniband/sw/rxe/rxe_net.c
+++ b/drivers/infiniband/sw/rxe/rxe_net.c
@@ -623,13 +623,23 @@ static struct notifier_block rxe_net_notifier = {
 
 static int rxe_net_ipv4_init(void)
 {
-	recv_sockets.sk4 = rxe_setup_udp_tunnel(&init_net,
-				htons(ROCE_V2_UDP_DPORT), false);
-	if (IS_ERR(recv_sockets.sk4)) {
-		recv_sockets.sk4 = NULL;
+	struct sock *sk;
+	struct socket *sock;
+
+	rcu_read_lock();
+	sk = udp4_lib_lookup(&init_net, 0, 0, htonl(INADDR_ANY),
+			     htons(ROCE_V2_UDP_DPORT), 0);
+	rcu_read_unlock();
+	if (sk)
+		return 0;
+
+	sock = rxe_setup_udp_tunnel(&init_net, htons(ROCE_V2_UDP_DPORT), false);
+	if (IS_ERR(sock)) {
 		pr_err("Failed to create IPv4 UDP tunnel\n");
+		recv_sockets.sk4 = NULL;
 		return -1;
 	}
+	recv_sockets.sk4 = sock;
 
 	return 0;
 }
@@ -637,24 +647,46 @@ static int rxe_net_ipv4_init(void)
 static int rxe_net_ipv6_init(void)
 {
 #if IS_ENABLED(CONFIG_IPV6)
+	struct sock *sk;
+	struct socket *sock;
+
+	rcu_read_lock();
+	sk = udp6_lib_lookup(&init_net, NULL, 0, &in6addr_any,
+			     htons(ROCE_V2_UDP_DPORT), 0);
+	rcu_read_unlock();
+	if (sk)
+		return 0;
 
-	recv_sockets.sk6 = rxe_setup_udp_tunnel(&init_net,
-						htons(ROCE_V2_UDP_DPORT), true);
-	if (PTR_ERR(recv_sockets.sk6) == -EAFNOSUPPORT) {
+	sock = rxe_setup_udp_tunnel(&init_net, htons(ROCE_V2_UDP_DPORT), true);
+	if (PTR_ERR(sock) == -EAFNOSUPPORT) {
 		recv_sockets.sk6 = NULL;
 		pr_warn("IPv6 is not supported, can not create a UDPv6 socket\n");
 		return 0;
 	}
 
-	if (IS_ERR(recv_sockets.sk6)) {
+	if (IS_ERR(sock)) {
 		recv_sockets.sk6 = NULL;
 		pr_err("Failed to create IPv6 UDP tunnel\n");
 		return -1;
 	}
+	recv_sockets.sk6 = sock;
 #endif
 	return 0;
 }
 
+int rxe_register_notifier(void)
+{
+	int err;
+
+	err = register_netdevice_notifier(&rxe_net_notifier);
+	if (err) {
+		pr_err("Failed to register netdev notifier\n");
+		return -1;
+	}
+
+	return 0;
+}
+
 void rxe_net_exit(void)
 {
 	rxe_release_udp_tunnel(recv_sockets.sk6);
@@ -666,19 +698,12 @@ int rxe_net_init(void)
 {
 	int err;
 
-	recv_sockets.sk6 = NULL;
-
 	err = rxe_net_ipv4_init();
 	if (err)
 		return err;
 	err = rxe_net_ipv6_init();
 	if (err)
 		goto err_out;
-	err = register_netdevice_notifier(&rxe_net_notifier);
-	if (err) {
-		pr_err("Failed to register netdev notifier\n");
-		goto err_out;
-	}
 	return 0;
 err_out:
 	rxe_net_exit();
diff --git a/drivers/infiniband/sw/rxe/rxe_net.h b/drivers/infiniband/sw/rxe/rxe_net.h
index 45d80d00f86b..a222c3eeae12 100644
--- a/drivers/infiniband/sw/rxe/rxe_net.h
+++ b/drivers/infiniband/sw/rxe/rxe_net.h
@@ -18,6 +18,7 @@ struct rxe_recv_sockets {
 
 int rxe_net_add(const char *ibdev_name, struct net_device *ndev);
 
+int rxe_register_notifier(void);
 int rxe_net_init(void);
 void rxe_net_exit(void);
 
-- 
2.27.0