mptcp: make MPTCP_ADD_ADDR_SIGNAL and MPTCP_ADD_ADDR_ECHO separate

Use MPTCP_ADD_ADDR_SIGNAL only for the action of sending ADD_ADDR, and
use MPTCP_ADD_ADDR_ECHO only for the action of sending ADD_ADDR echo.

Use msk->pm.local to save the announced ADD_ADDR address only, and reuse
msk->pm.remote to save the announced ADD_ADDR_ECHO address.

To prepare for the next patch.
Co-developed-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mptcp/pm.c

@@ -20,19 +20,23 @@ int mptcp_pm_announce_addr(struct mptcp_sock *msk,
 {
 	u8 add_addr = READ_ONCE(msk->pm.addr_signal);
 
-	pr_debug("msk=%p, local_id=%d", msk, addr->id);
+	pr_debug("msk=%p, local_id=%d, echo=%d", msk, addr->id, echo);
 
 	lockdep_assert_held(&msk->pm.lock);
 
-	if (add_addr) {
-		pr_warn("addr_signal error, add_addr=%d", add_addr);
+	if (add_addr &
+	    (echo ? BIT(MPTCP_ADD_ADDR_ECHO) : BIT(MPTCP_ADD_ADDR_SIGNAL))) {
+		pr_warn("addr_signal error, add_addr=%d, echo=%d", add_addr, echo);
 		return -EINVAL;
 	}
 
-	msk->pm.local = *addr;
-	add_addr |= BIT(MPTCP_ADD_ADDR_SIGNAL);
-	if (echo)
+	if (echo) {
+		msk->pm.remote = *addr;
 		add_addr |= BIT(MPTCP_ADD_ADDR_ECHO);
+	} else {
+		msk->pm.local = *addr;
+		add_addr |= BIT(MPTCP_ADD_ADDR_SIGNAL);
+	}
 	if (addr->family == AF_INET6)
 		add_addr |= BIT(MPTCP_ADD_ADDR_IPV6);
 	if (addr->port)

net/mptcp/pm_netlink.c

@@ -317,14 +317,14 @@ static void mptcp_pm_add_timer(struct timer_list *timer)
 	if (!entry->addr.id)
 		return;
 
-	if (mptcp_pm_should_add_signal(msk)) {
+	if (mptcp_pm_should_add_signal_addr(msk)) {
 		sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX / 8);
 		goto out;
 	}
 
 	spin_lock_bh(&msk->pm.lock);
 
-	if (!mptcp_pm_should_add_signal(msk)) {
+	if (!mptcp_pm_should_add_signal_addr(msk)) {
 		pr_debug("retransmit ADD_ADDR id=%d", entry->addr.id);
 		mptcp_pm_announce_addr(msk, &entry->addr, false);
 		mptcp_pm_add_addr_send_ack(msk);

net/mptcp/protocol.h

@@ -747,6 +747,12 @@ void mptcp_event_addr_announced(const struct mptcp_sock *msk, const struct mptcp
 void mptcp_event_addr_removed(const struct mptcp_sock *msk, u8 id);
 
 static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
+{
+	return READ_ONCE(msk->pm.addr_signal) &
+		(BIT(MPTCP_ADD_ADDR_SIGNAL) | BIT(MPTCP_ADD_ADDR_ECHO));
+}
+
+static inline bool mptcp_pm_should_add_signal_addr(struct mptcp_sock *msk)
 {
 	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_SIGNAL);
 }