mptcp: send ack for rm_addr

This patch changes the sending ACK conditions for the ADD_ADDR, send an
ACK packet for RM_ADDR too.

In mptcp_pm_remove_addr, invoke mptcp_pm_nl_add_addr_send_ack to send
the ACK packet.
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mptcp/pm.c

@@ -53,6 +53,7 @@ int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_
 	msk->pm.rm_list_tx = *rm_list;
 	rm_addr |= BIT(MPTCP_RM_ADDR_SIGNAL);
 	WRITE_ONCE(msk->pm.addr_signal, rm_addr);
+	mptcp_pm_nl_add_addr_send_ack(msk);
 	return 0;
 }
 

net/mptcp/pm_netlink.c

@@ -56,8 +56,6 @@ struct pm_nl_pernet {
 #define MPTCP_PM_ADDR_MAX	8
 #define ADD_ADDR_RETRANS_MAX	3
 
-static void mptcp_pm_nl_add_addr_send_ack(struct mptcp_sock *msk);
-
 static bool addresses_equal(const struct mptcp_addr_info *a,
 			    struct mptcp_addr_info *b, bool use_port)
 {
@@ -524,14 +522,15 @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
 	mptcp_pm_nl_add_addr_send_ack(msk);
 }
 
-static void mptcp_pm_nl_add_addr_send_ack(struct mptcp_sock *msk)
+void mptcp_pm_nl_add_addr_send_ack(struct mptcp_sock *msk)
 {
 	struct mptcp_subflow_context *subflow;
 
 	msk_owned_by_me(msk);
 	lockdep_assert_held(&msk->pm.lock);
 
-	if (!mptcp_pm_should_add_signal(msk))
+	if (!mptcp_pm_should_add_signal(msk) &&
+	    !mptcp_pm_should_rm_signal(msk))
 		return;
 
 	__mptcp_flush_join_list(msk);
@@ -540,7 +539,8 @@ static void mptcp_pm_nl_add_addr_send_ack(struct mptcp_sock *msk)
 		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 
 		spin_unlock_bh(&msk->pm.lock);
-		pr_debug("send ack for add_addr%s%s",
+		pr_debug("send ack for %s%s%s",
+			 mptcp_pm_should_add_signal(msk) ? "add_addr" : "rm_addr",
 			 mptcp_pm_should_add_signal_ipv6(msk) ? " [ipv6]" : "",
 			 mptcp_pm_should_add_signal_port(msk) ? " [port]" : "");
 

net/mptcp/protocol.h

@@ -650,6 +650,7 @@ void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
 void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
 			      struct mptcp_addr_info *addr);
 void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk);
+void mptcp_pm_nl_add_addr_send_ack(struct mptcp_sock *msk);
 void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
 			       const struct mptcp_rm_list *rm_list);
 void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);