[MPTCP] [MPTCP][PATCH v4 mptcp-next 4/5] mptcp: trigger the RM_ADDR signal

[MPTCP] [MPTCP][PATCH v4 mptcp-next 4/5] mptcp: trigger the RM_ADDR signal

[Geliang Tang]

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The patch adds a new list named anno_list in mptcp_pm_data, to record all
the announced addrs. When the PM netlink removes an address, we check if
it has been recorded. If it has been, we trigger the RM_ADDR signal.

Suggested-by: Matthieu Baerts <matthieu.baerts(a)tessares.net>
Suggested-by: Paolo Abeni <pabeni(a)redhat.com>
Suggested-by: Mat Martineau <mathew.j.martineau(a)linux.intel.com>
Signed-off-by: Geliang Tang <geliangtang(a)gmail.com>
---
 net/mptcp/pm.c         |  7 +++++-
 net/mptcp/pm_netlink.c | 49 +++++++++++++++++++++++++++++++++++++++++-
 net/mptcp/protocol.c   |  2 ++
 net/mptcp/protocol.h   |  2 ++
 4 files changed, 58 insertions(+), 2 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 558462d87eb3..b3712771f268 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -24,7 +24,11 @@ int mptcp_pm_announce_addr(struct mptcp_sock *msk,
 
 int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id)
 {
-	return -ENOTSUPP;
+	pr_debug("msk=%p, local_id=%d", msk, local_id);
+
+	msk->pm.rm_id = local_id;
+	WRITE_ONCE(msk->pm.rm_addr_signal, true);
+	return 0;
 }
 
 int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 remote_id)
@@ -229,6 +233,7 @@ void mptcp_pm_data_init(struct mptcp_sock *msk)
 	msk->pm.status = 0;
 
 	spin_lock_init(&msk->pm.lock);
+	INIT_LIST_HEAD(&msk->pm.anno_list);
 
 	mptcp_pm_nl_data_init(msk);
 }
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 74a18e463c3d..b9f0622e4082 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -169,6 +169,19 @@ static void check_work_pending(struct mptcp_sock *msk)
 		WRITE_ONCE(msk->pm.work_pending, false);
 }
 
+void mptcp_pm_free_anno_list(struct mptcp_sock *msk)
+{
+	struct mptcp_pm_addr_entry *entry, *tmp;
+
+	pr_debug("msk=%p\n", msk);
+	spin_lock_bh(&msk->pm.lock);
+	list_for_each_entry_safe(entry, tmp, &msk->pm.anno_list, list) {
+		list_del(&entry->list);
+		kfree(entry);
+	}
+	spin_unlock_bh(&msk->pm.lock);
+}
+
 static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 {
 	struct sock *sk = (struct sock *)msk;
@@ -189,8 +202,16 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 					      msk->pm.add_addr_signaled);
 
 		if (local) {
+			struct mptcp_pm_addr_entry *clone = NULL;
+
 			msk->pm.add_addr_signaled++;
 			mptcp_pm_announce_addr(msk, &local->addr);
+
+			clone = kmemdup(local, sizeof(*local), GFP_ATOMIC);
+			if (!clone)
+				return;
+
+			list_add(&clone->list, &msk->pm.anno_list);
 		} else {
 			/* pick failed, avoid fourther attempts later */
 			msk->pm.local_addr_used = msk->pm.add_addr_signal_max;
@@ -548,6 +569,30 @@ __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id)
 	return NULL;
 }
 
+static void mptcp_nl_remove_addr(struct sk_buff *skb, struct mptcp_addr_info *addr)
+{
+	struct mptcp_sock *msk;
+	long s_slot = 0, s_num = 0;
+	struct net *net = sock_net(skb->sk);
+
+	while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
+		struct mptcp_pm_addr_entry *entry, *tmp;
+		struct sock *sk = (struct sock *)msk;
+
+		pr_debug("msk=%p\n", msk);
+		spin_lock_bh(&msk->pm.lock);
+		list_for_each_entry_safe(entry, tmp, &msk->pm.anno_list, list) {
+			if (addresses_equal(&entry->addr, addr, false)) {
+				mptcp_pm_remove_addr(msk, addr->id);
+				list_del(&entry->list);
+				kfree(entry);
+			}
+		}
+		spin_unlock_bh(&msk->pm.lock);
+		sock_put(sk);
+	}
+}
+
 static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
 {
 	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
@@ -566,8 +611,10 @@ static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
 		ret = -EINVAL;
 		goto out;
 	}
-	if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)
+	if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
 		pernet->add_addr_signal_max--;
+		mptcp_nl_remove_addr(skb, &entry->addr);
+	}
 	if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)
 		pernet->local_addr_max--;
 
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 2f43d0296951..deb89f3ab3ad 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1640,6 +1640,8 @@ static void mptcp_close(struct sock *sk, long timeout)
 		__mptcp_close_ssk(sk, ssk, subflow, timeout);
 	}
 
+	mptcp_pm_free_anno_list(msk);
+
 	mptcp_cancel_work(sk);
 
 	__skb_queue_purge(&sk->sk_receive_queue);
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 717b3aee776c..a10c53c2c0ee 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -177,6 +177,7 @@ struct mptcp_pm_data {
 	u8		subflows_max;
 	u8		status;
 	u8		rm_id;
+	struct list_head anno_list;
 };
 
 struct mptcp_data_frag {
@@ -433,6 +434,7 @@ int mptcp_pm_announce_addr(struct mptcp_sock *msk,
 			   const struct mptcp_addr_info *addr);
 int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id);
 int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 remote_id);
+void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
 
 static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
 {
-- 
2.17.1