mptcp: remove address when netlink flushes addrs

When the PM netlink flushes the addresses, invoke the remove address
function mptcp_nl_remove_subflow_and_signal_addr to remove the addresses
and the subflows. Since this function should not be invoked under lock,
move __flush_addrs out of the pernet->lock.

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_netlink.c

@@ -867,13 +867,14 @@ static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
 	return ret;
 }
 
-static void __flush_addrs(struct pm_nl_pernet *pernet)
+static void __flush_addrs(struct net *net, struct list_head *list)
 {
-	while (!list_empty(&pernet->local_addr_list)) {
+	while (!list_empty(list)) {
 		struct mptcp_pm_addr_entry *cur;
 
-		cur = list_entry(pernet->local_addr_list.next,
+		cur = list_entry(list->next,
 				 struct mptcp_pm_addr_entry, list);
+		mptcp_nl_remove_subflow_and_signal_addr(net, &cur->addr);
 		list_del_rcu(&cur->list);
 		kfree_rcu(cur, rcu);
 	}
@@ -890,11 +891,13 @@ static void __reset_counters(struct pm_nl_pernet *pernet)
 static int mptcp_nl_cmd_flush_addrs(struct sk_buff *skb, struct genl_info *info)
 {
 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
+	LIST_HEAD(free_list);
 
 	spin_lock_bh(&pernet->lock);
-	__flush_addrs(pernet);
+	list_splice_init(&pernet->local_addr_list, &free_list);
 	__reset_counters(pernet);
 	spin_unlock_bh(&pernet->lock);
+	__flush_addrs(sock_net(skb->sk), &free_list);
 	return 0;
 }
 
@@ -1156,10 +1159,12 @@ static void __net_exit pm_nl_exit_net(struct list_head *net_list)
 	struct net *net;
 
 	list_for_each_entry(net, net_list, exit_list) {
+		struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
+
 		/* net is removed from namespace list, can't race with
 		 * other modifiers
 		 */
-		__flush_addrs(net_generic(net, pm_nl_pernet_id));
+		__flush_addrs(net, &pernet->local_addr_list);
 	}
 }