mptcp: add pm listener events

This patch adds two new MPTCP netlink event types for PM listening
socket create and close, named MPTCP_EVENT_LISTENER_CREATED and
MPTCP_EVENT_LISTENER_CLOSED.

Add a new function mptcp_event_pm_listener() to push the new events
with family, port and addr to userspace.

Invoke mptcp_event_pm_listener() with MPTCP_EVENT_LISTENER_CREATED in
mptcp_listen() and mptcp_pm_nl_create_listen_socket(), invoke it with
MPTCP_EVENT_LISTENER_CLOSED in __mptcp_close_ssk().

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 57 insertions, 0 deletions

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index d66fbd558263..eef69d0e44ec 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1029,6 +1029,8 @@ static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
 	if (err)
 		return err;
 
+	mptcp_event_pm_listener(ssock->sk, MPTCP_EVENT_LISTENER_CREATED);
+
 	return 0;
 }
 
@@ -2152,6 +2154,58 @@ nla_put_failure:
 	kfree_skb(skb);
 }
 
+void mptcp_event_pm_listener(const struct sock *ssk,
+			     enum mptcp_event_type event)
+{
+	const struct inet_sock *issk = inet_sk(ssk);
+	struct net *net = sock_net(ssk);
+	struct nlmsghdr *nlh;
+	struct sk_buff *skb;
+
+	if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
+		return;
+
+	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!skb)
+		return;
+
+	nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, event);
+	if (!nlh)
+		goto nla_put_failure;
+
+	if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family))
+		goto nla_put_failure;
+
+	if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport))
+		goto nla_put_failure;
+
+	switch (ssk->sk_family) {
+	case AF_INET:
+		if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr))
+			goto nla_put_failure;
+		break;
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+	case AF_INET6: {
+		const struct ipv6_pinfo *np = inet6_sk(ssk);
+
+		if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &np->saddr))
+			goto nla_put_failure;
+		break;
+	}
+#endif
+	default:
+		WARN_ON_ONCE(1);
+		goto nla_put_failure;
+	}
+
+	genlmsg_end(skb, nlh);
+	mptcp_nl_mcast_send(net, skb, GFP_KERNEL);
+	return;
+
+nla_put_failure:
+	kfree_skb(skb);
+}
+
 void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
 		 const struct sock *ssk, gfp_t gfp)
 {
@@ -2197,6 +2251,9 @@ void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
 		if (mptcp_event_sub_closed(skb, msk, ssk) < 0)
 			goto nla_put_failure;
 		break;
+	case MPTCP_EVENT_LISTENER_CREATED:
+	case MPTCP_EVENT_LISTENER_CLOSED:
+		break;
 	}
 
 	genlmsg_end(skb, nlh);