mptcp: unify pm get_flags_and_ifindex_by_id

This patch unifies the three PM get_flags_and_ifindex_by_id() interfaces:

mptcp_pm_nl_get_flags_and_ifindex_by_id() in mptcp/pm_netlink.c for the
in-kernel PM and mptcp_userspace_pm_get_flags_and_ifindex_by_id() in
mptcp/pm_userspace.c for the userspace PM.

They'll be switched in the common PM infterface
mptcp_pm_get_flags_and_ifindex_by_id() in mptcp/pm.c based on whether
mptcp_pm_is_userspace() or not.
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/mptcp/pm.c

@@ -434,6 +434,20 @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 	return mptcp_pm_nl_get_local_id(msk, &skc_local);
 }
 
+int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id,
+					 u8 *flags, int *ifindex)
+{
+	*flags = 0;
+	*ifindex = 0;
+
+	if (!id)
+		return 0;
+
+	if (mptcp_pm_is_userspace(msk))
+		return mptcp_userspace_pm_get_flags_and_ifindex_by_id(msk, id, flags, ifindex);
+	return mptcp_pm_nl_get_flags_and_ifindex_by_id(msk, id, flags, ifindex);
+}
+
 void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);

net/mptcp/pm_netlink.c

@@ -1356,31 +1356,20 @@ static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info)
 	return ret;
 }
 
-int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id,
-					 u8 *flags, int *ifindex)
+int mptcp_pm_nl_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id,
+					    u8 *flags, int *ifindex)
 {
 	struct mptcp_pm_addr_entry *entry;
 	struct sock *sk = (struct sock *)msk;
 	struct net *net = sock_net(sk);
 
-	*flags = 0;
-	*ifindex = 0;
-
-	if (id) {
-		if (mptcp_pm_is_userspace(msk))
-			return mptcp_userspace_pm_get_flags_and_ifindex_by_id(msk,
-									      id,
-									      flags,
-									      ifindex);
-
-		rcu_read_lock();
-		entry = __lookup_addr_by_id(pm_nl_get_pernet(net), id);
-		if (entry) {
-			*flags = entry->flags;
-			*ifindex = entry->ifindex;
-		}
-		rcu_read_unlock();
+	rcu_read_lock();
+	entry = __lookup_addr_by_id(pm_nl_get_pernet(net), id);
+	if (entry) {
+		*flags = entry->flags;
+		*ifindex = entry->ifindex;
 	}
+	rcu_read_unlock();
 
 	return 0;
 }

net/mptcp/pm_userspace.c

@@ -111,9 +111,6 @@ int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
 {
 	struct mptcp_pm_addr_entry *entry, *match = NULL;
 
-	*flags = 0;
-	*ifindex = 0;
-
 	spin_lock_bh(&msk->pm.lock);
 	list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
 		if (id == entry->addr.id) {

net/mptcp/protocol.h

@@ -822,6 +822,8 @@ mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
 int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
 					 unsigned int id,
 					 u8 *flags, int *ifindex);
+int mptcp_pm_nl_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id,
+					    u8 *flags, int *ifindex);
 int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
 						   unsigned int id,
 						   u8 *flags, int *ifindex);