mptcp: send ack for every add_addr

This patch changes the sending ACK conditions for the ADD_ADDR, send an
ACK packet for any ADD_ADDR, not just when ipv6 addresses or port
numbers are included.

Closes: multipath-tcp/mptcp_net-next#139
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/mptcp/pm.c

@@ -191,8 +191,7 @@ void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
 
 void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk)
 {
-	if (!mptcp_pm_should_add_signal_ipv6(msk) &&
-	    !mptcp_pm_should_add_signal_port(msk))
+	if (!mptcp_pm_should_add_signal(msk))
 		return;
 
 	mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_SEND_ACK);

net/mptcp/pm_netlink.c

@@ -474,8 +474,7 @@ void mptcp_pm_nl_add_addr_send_ack(struct mptcp_sock *msk)
 {
 	struct mptcp_subflow_context *subflow;
 
-	if (!mptcp_pm_should_add_signal_ipv6(msk) &&
-	    !mptcp_pm_should_add_signal_port(msk))
+	if (!mptcp_pm_should_add_signal(msk))
 		return;
 
 	__mptcp_flush_join_list(msk);
@@ -485,10 +484,9 @@ void mptcp_pm_nl_add_addr_send_ack(struct mptcp_sock *msk)
 		u8 add_addr;
 
 		spin_unlock_bh(&msk->pm.lock);
-		if (mptcp_pm_should_add_signal_ipv6(msk))
-			pr_debug("send ack for add_addr6");
-		if (mptcp_pm_should_add_signal_port(msk))
-			pr_debug("send ack for add_addr_port");
+		pr_debug("send ack for add_addr%s%s",
+			 mptcp_pm_should_add_signal_ipv6(msk) ? " [ipv6]" : "",
+			 mptcp_pm_should_add_signal_port(msk) ? " [port]" : "");
 
 		lock_sock(ssk);
 		tcp_send_ack(ssk);