From: Geliang Tang <tanggeliang@kylinos.cn>

is_backup() interface of the path managers is not very common. A more
common approach is to add a get_flags() interface to obtain the flags
value of a given address. Then is_backup() can be implemented through
get_flags() by test whether backup flag is set in the flags value.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c           |  7 +++++--
 net/mptcp/pm_netlink.c   |  9 +++++----
 net/mptcp/pm_userspace.c | 10 +++++-----
 net/mptcp/protocol.h     |  6 ++++--
 4 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 8d9acc984a36..a0f4d06692cc 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -429,13 +429,16 @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc)
 {
 	struct mptcp_addr_info skc_local;
+	u8 flags;
 
 	mptcp_local_address((struct sock_common *)skc, &skc_local);
 
 	if (mptcp_pm_is_userspace(msk))
-		return mptcp_userspace_pm_is_backup(msk, &skc_local);
+		flags = mptcp_userspace_pm_get_flags(msk, &skc_local);
+	else
+		flags = mptcp_pm_nl_get_flags(msk, &skc_local);
 
-	return mptcp_pm_nl_is_backup(msk, &skc_local);
+	return !!(flags & MPTCP_PM_ADDR_FLAG_BACKUP);
 }
 
 static int mptcp_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 16c901fabfa2..4be4214cad34 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1168,18 +1168,19 @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
 	return ret;
 }
 
-bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
+u8 mptcp_pm_nl_get_flags(struct mptcp_sock *msk,
+			 struct mptcp_addr_info *skc)
 {
 	struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 	struct mptcp_pm_addr_entry *entry;
-	bool backup;
+	u8 flags;
 
 	rcu_read_lock();
 	entry = __lookup_addr(pernet, skc);
-	backup = entry && !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
+	flags = entry ? entry->flags : 0;
 	rcu_read_unlock();
 
-	return backup;
+	return flags;
 }
 
 #define MPTCP_PM_CMD_GRP_OFFSET       0
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index 22d240128490..34c9f03138ae 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -149,18 +149,18 @@ int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
 	return mptcp_userspace_pm_append_new_local_addr(msk, local, true);
 }
 
-bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
-				  struct mptcp_addr_info *skc)
+u8 mptcp_userspace_pm_get_flags(struct mptcp_sock *msk,
+				struct mptcp_addr_info *skc)
 {
 	struct mptcp_pm_addr_entry *entry;
-	bool backup;
+	u8 flags;
 
 	spin_lock_bh(&msk->pm.lock);
 	entry = mptcp_userspace_pm_lookup_addr(msk, skc);
-	backup = entry && !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
+	flags = entry ? entry->flags : 0;
 	spin_unlock_bh(&msk->pm.lock);
 
-	return backup;
+	return flags;
 }
 
 static struct mptcp_sock *mptcp_userspace_pm_get_sock(const struct genl_info *info)
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 6f885bd5572d..70a7b5b2f47f 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -1131,8 +1131,10 @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
 int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
 				    struct mptcp_pm_addr_entry *local);
 bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc);
-bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
-bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
+u8 mptcp_pm_nl_get_flags(struct mptcp_sock *msk,
+			 struct mptcp_addr_info *skc);
+u8 mptcp_userspace_pm_get_flags(struct mptcp_sock *msk,
+				struct mptcp_addr_info *skc);
 int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
 			  struct netlink_callback *cb);
 int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
-- 
2.43.0