[PATCH mptcp-next v2 01/21] mptcp: do not restrict subflows with non-kernel PMs

[Kishen Maloor <kishen.maloor@intel.com>]

All numerical restrictions on # of addresses/subflows
currently apply only to in-kernel PM managed connections.
Thus this change removes limitations on adding new subflows
by non-kernel (e.g. userspace) PMs.

Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
---
 net/mptcp/pm.c      | 7 +++++++
 net/mptcp/subflow.c | 3 ++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 1f8878cc29e3..5f35fe8a5e82 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -87,6 +87,13 @@ bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
 	unsigned int subflows_max;
 	int ret = 0;
 
+	if (READ_ONCE(pm->pm_type) != MPTCP_PM_TYPE_KERNEL) {
+		spin_lock_bh(&msk->pm.lock);
+		++pm->subflows;
+		spin_unlock_bh(&msk->pm.lock);
+		return true;
+	}
+
 	subflows_max = mptcp_pm_get_subflows_max(msk);
 
 	pr_debug("msk=%p subflows=%d max=%d allow=%d", msk, pm->subflows,
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index fd5fdb639088..b009d0f7fb77 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -62,7 +62,8 @@ static void subflow_generate_hmac(u64 key1, u64 key2, u32 nonce1, u32 nonce2,
 static bool mptcp_can_accept_new_subflow(const struct mptcp_sock *msk)
 {
 	return mptcp_is_fully_established((void *)msk) &&
-	       READ_ONCE(msk->pm.accept_subflow);
+	       ((READ_ONCE(msk->pm.pm_type) != MPTCP_PM_TYPE_KERNEL) ||
+		READ_ONCE(msk->pm.accept_subflow));
 }
 
 /* validate received token and create truncated hmac and nonce for SYN-ACK */
-- 
2.31.1