mptcp: build ADD_ADDR/echo-ADD_ADDR option according pm.add_signal

According to the MPTCP_ADD_ADDR_SIGNAL or MPTCP_ADD_ADDR_ECHO flag, build
the ADD_ADDR/ADD_ADDR_ECHO option.

In mptcp_pm_add_addr_signal(), use opts->addr to save the announced
ADD_ADDR or ADD_ADDR_ECHO address.

Co-developed-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.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

@@ -257,11 +257,12 @@ void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup)
 
 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, struct sk_buff *skb,
 			      unsigned int opt_size, unsigned int remaining,
-			      struct mptcp_addr_info *saddr, bool *echo,
+			      struct mptcp_addr_info *addr, bool *echo,
 			      bool *port, bool *drop_other_suboptions)
 {
 	int ret = false;
 	u8 add_addr;
+	u8 family;
 
 	spin_lock_bh(&msk->pm.lock);
 
@@ -281,14 +282,17 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, struct sk_buff *skb,
 	*echo = mptcp_pm_should_add_signal_echo(msk);
 	*port = mptcp_pm_should_add_signal_port(msk);
 
-	if (remaining < mptcp_add_addr_len(msk->pm.local.family, *echo, *port))
+	family = *echo ? msk->pm.remote.family : msk->pm.local.family;
+	if (remaining < mptcp_add_addr_len(family, *echo, *port))
 		goto out_unlock;
 
-	*saddr = msk->pm.local;
-	if (*echo)
+	if (*echo) {
+		*addr = msk->pm.remote;
 		add_addr = msk->pm.addr_signal & ~BIT(MPTCP_ADD_ADDR_ECHO);
-	else
+	} else {
+		*addr = msk->pm.local;
 		add_addr = msk->pm.addr_signal & ~BIT(MPTCP_ADD_ADDR_SIGNAL);
+	}
 	WRITE_ONCE(msk->pm.addr_signal, add_addr);
 	ret = true;
 

net/mptcp/protocol.h

@@ -802,7 +802,7 @@ static inline int mptcp_rm_addr_len(const struct mptcp_rm_list *rm_list)
 
 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, struct sk_buff *skb,
 			      unsigned int opt_size, unsigned int remaining,
-			      struct mptcp_addr_info *saddr, bool *echo,
+			      struct mptcp_addr_info *addr, bool *echo,
 			      bool *port, bool *drop_other_suboptions);
 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 			     struct mptcp_rm_list *rm_list);