mptcp: unify pm get_local_id interfaces

This patch unifies the three PM get_local_id() interfaces:

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

They'll be switched in the common PM infterface mptcp_pm_get_local_id()
in mptcp/pm.c based on whether mptcp_pm_is_userspace() or not.

Also put together the declarations of these three functions in protocol.h.

Signed-off-by: Geliang Tang <[email protected]>
Reviewed-by: Matthieu Baerts <[email protected]>
Signed-off-by: Matthieu Baerts <[email protected]>
Reviewed-by: Larysa Zaremba <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>

1 files changed, 17 insertions, 1 deletions

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 92d540e527a2..300fa9bea047 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -415,7 +415,23 @@ out_unlock:
 
 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 {
-	return mptcp_pm_nl_get_local_id(msk, skc);
+	struct mptcp_addr_info skc_local;
+	struct mptcp_addr_info msk_local;
+
+	if (WARN_ON_ONCE(!msk))
+		return -1;
+
+	/* The 0 ID mapping is defined by the first subflow, copied into the msk
+	 * addr
+	 */
+	mptcp_local_address((struct sock_common *)msk, &msk_local);
+	mptcp_local_address((struct sock_common *)skc, &skc_local);
+	if (mptcp_addresses_equal(&msk_local, &skc_local, false))
+		return 0;
+
+	if (mptcp_pm_is_userspace(msk))
+		return mptcp_userspace_pm_get_local_id(msk, &skc_local);
+	return mptcp_pm_nl_get_local_id(msk, &skc_local);
 }
 
 void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)