From: Geliang Tang <tanggeliang@kylinos.cn>

Like __lookup_addr() helper in pm_netlink.c, a new helper
mptcp_userspace_pm_lookup_addr() is also defined in pm_userspace.c.
It looks up the corresponding mptcp_pm_addr_entry address in
userspace_pm_local_addr_list through the passed "addr" parameter
and returns it.

This helper can be used in mptcp_userspace_pm_delete_local_addr(),
mptcp_userspace_pm_get_local_id() and mptcp_userspace_pm_is_backup()
to simplify the code.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm_userspace.c | 56 +++++++++++++++++++++-------------------
 1 file changed, 29 insertions(+), 27 deletions(-)

diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index b7272289d4c1..58599f32b279 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -26,6 +26,18 @@ void mptcp_free_local_addr_list(struct mptcp_sock *msk)
 	}
 }
 
+static struct mptcp_pm_addr_entry *
+mptcp_userspace_pm_lookup_addr(struct mptcp_sock *msk, const struct mptcp_addr_info *addr)
+{
+	struct mptcp_pm_addr_entry *entry, *tmp;
+
+	list_for_each_entry_safe(entry, tmp, &msk->pm.userspace_pm_local_addr_list, list) {
+		if (mptcp_addresses_equal(&entry->addr, addr, false))
+			return entry;
+	}
+	return NULL;
+}
+
 static int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
 						    struct mptcp_pm_addr_entry *entry,
 						    bool needs_id)
@@ -90,22 +102,20 @@ static int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
 static int mptcp_userspace_pm_delete_local_addr(struct mptcp_sock *msk,
 						struct mptcp_pm_addr_entry *addr)
 {
-	struct mptcp_pm_addr_entry *entry, *tmp;
 	struct sock *sk = (struct sock *)msk;
+	struct mptcp_pm_addr_entry *entry;
 
-	list_for_each_entry_safe(entry, tmp, &msk->pm.userspace_pm_local_addr_list, list) {
-		if (mptcp_addresses_equal(&entry->addr, &addr->addr, false)) {
-			/* TODO: a refcount is needed because the entry can
-			 * be used multiple times (e.g. fullmesh mode).
-			 */
-			list_del_rcu(&entry->list);
-			sock_kfree_s(sk, entry, sizeof(*entry));
-			msk->pm.local_addr_used--;
-			return 0;
-		}
-	}
-
-	return -EINVAL;
+	entry = mptcp_userspace_pm_lookup_addr(msk, &addr->addr);
+	if (!entry)
+		return -EINVAL;
+
+	/* TODO: a refcount is needed because the entry can
+	 * be used multiple times (e.g. fullmesh mode).
+	 */
+	list_del_rcu(&entry->list);
+	sock_kfree_s(sk, entry, sizeof(*entry));
+	msk->pm.local_addr_used--;
+	return 0;
 }
 
 static struct mptcp_pm_addr_entry *
@@ -123,17 +133,12 @@ mptcp_userspace_pm_lookup_addr_by_id(struct mptcp_sock *msk, unsigned int id)
 int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
 				    struct mptcp_addr_info *skc)
 {
-	struct mptcp_pm_addr_entry *entry = NULL, *e, new_entry;
+	struct mptcp_pm_addr_entry *entry = NULL, new_entry;
 	__be16 msk_sport =  ((struct inet_sock *)
 			     inet_sk((struct sock *)msk))->inet_sport;
 
 	spin_lock_bh(&msk->pm.lock);
-	list_for_each_entry(e, &msk->pm.userspace_pm_local_addr_list, list) {
-		if (mptcp_addresses_equal(&e->addr, skc, false)) {
-			entry = e;
-			break;
-		}
-	}
+	entry = mptcp_userspace_pm_lookup_addr(msk, skc);
 	spin_unlock_bh(&msk->pm.lock);
 	if (entry)
 		return entry->addr.id;
@@ -156,12 +161,9 @@ bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
 	bool backup = false;
 
 	spin_lock_bh(&msk->pm.lock);
-	list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
-		if (mptcp_addresses_equal(&entry->addr, skc, false)) {
-			backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
-			break;
-		}
-	}
+	entry = mptcp_userspace_pm_lookup_addr(msk, skc);
+	if (entry)
+		backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
 	spin_unlock_bh(&msk->pm.lock);
 
 	return backup;
-- 
2.43.0