[MPTCP][PATCH v2 mptcp-next 04/10] mptcp: add netdev up event handler

[Geliang Tang <geliangtang@gmail.com>]

This patch added the net device UP event handler function named
mptcp_fm_cmd_add_addr. In it, alloc an address entry, populate it, and
append this entry to the local address list. Then invoke
mptcp_nl_add_subflow_or_signal_addr to create the new subflows.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
---
 include/uapi/linux/mptcp.h |  1 +
 net/mptcp/pm_fullmesh.c    |  3 +++
 net/mptcp/pm_netlink.c     | 31 +++++++++++++++++++++++++++++--
 net/mptcp/protocol.h       |  1 +
 4 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h
index 7b05f7102321..f66038b9551f 100644
--- a/include/uapi/linux/mptcp.h
+++ b/include/uapi/linux/mptcp.h
@@ -73,6 +73,7 @@ enum {
 #define MPTCP_PM_ADDR_FLAG_SIGNAL			(1 << 0)
 #define MPTCP_PM_ADDR_FLAG_SUBFLOW			(1 << 1)
 #define MPTCP_PM_ADDR_FLAG_BACKUP			(1 << 2)
+#define MPTCP_PM_ADDR_FLAG_FULLMESH			(1 << 3)
 
 enum {
 	MPTCP_PM_CMD_UNSPEC,
diff --git a/net/mptcp/pm_fullmesh.c b/net/mptcp/pm_fullmesh.c
index bac06ddc658b..6c52a64657f4 100644
--- a/net/mptcp/pm_fullmesh.c
+++ b/net/mptcp/pm_fullmesh.c
@@ -14,6 +14,9 @@ static void addr_event_handler(unsigned long event, struct net *net,
 {
 	if (!mptcp_is_fullmesh_enabled(net))
 		return;
+
+	if (event == NETDEV_UP)
+		mptcp_fm_cmd_add_addr(net, addr);
 }
 
 static int mptcp_pm_addr4_event(struct notifier_block *this,
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index ac0aa6faacfa..3437de74f003 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -170,7 +170,8 @@ select_local_address(const struct pm_nl_pernet *pernet,
 	rcu_read_lock();
 	__mptcp_flush_join_list(msk);
 	list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
-		if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW))
+		if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) &&
+		    !(entry->flags & MPTCP_PM_ADDR_FLAG_FULLMESH))
 			continue;
 
 		if (entry->addr.family != sk->sk_family) {
@@ -745,7 +746,8 @@ static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
 		addr_max = pernet->add_addr_signal_max;
 		WRITE_ONCE(pernet->add_addr_signal_max, addr_max + 1);
 	}
-	if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
+	if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW ||
+	    entry->flags & MPTCP_PM_ADDR_FLAG_FULLMESH) {
 		addr_max = pernet->local_addr_max;
 		WRITE_ONCE(pernet->local_addr_max, addr_max + 1);
 	}
@@ -1954,6 +1956,31 @@ static struct genl_family mptcp_genl_family __ro_after_init = {
 	.n_mcgrps	= ARRAY_SIZE(mptcp_pm_mcgrps),
 };
 
+#if IS_ENABLED(CONFIG_MPTCP_FULLMESH)
+
+int mptcp_fm_cmd_add_addr(struct net *net, const struct mptcp_addr_info *addr)
+{
+	struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
+	struct mptcp_pm_addr_entry *entry;
+
+	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
+	if (!entry)
+		return -ENOMEM;
+
+	entry->addr = *addr;
+	entry->addr.id = 0;
+	entry->addr.port = 0;
+	entry->flags |= MPTCP_PM_ADDR_FLAG_FULLMESH;
+	entry->ifindex = 0;
+
+	mptcp_pm_nl_append_new_local_addr(pernet, entry);
+	mptcp_nl_add_subflow_or_signal_addr(net);
+
+	return 0;
+}
+
+#endif
+
 static int __net_init pm_nl_init_net(struct net *net)
 {
 	struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 2c3a4d507454..78a9cd90b0f9 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -812,6 +812,7 @@ unsigned int mptcp_pm_get_subflows_max(struct mptcp_sock *msk);
 unsigned int mptcp_pm_get_local_addr_max(struct mptcp_sock *msk);
 #if IS_ENABLED(CONFIG_MPTCP_FULLMESH)
 void __init mptcp_pm_fm_init(void);
+int mptcp_fm_cmd_add_addr(struct net *net, const struct mptcp_addr_info *addr);
 #endif
 
 void mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk);
-- 
2.31.1