From: Bjorn Andersson <bjorn.andersson@linaro.org>
Date: Wed, 7 Jun 2017 14:07:38 -0700
Subject: net: qrtr: Broadcast DEL_CLIENT message when endpoint is closed
Patch-mainline: v4.13-rc1
Git-commit: 1784473b242585f407d3e75654d5b06f462a355b
References: bsc#1056787

Per the QMUXv2 protocol specificiation a DEL_CLIENT message should be
broadcasted when an endpoint is disconnected.

The protocol specification does suggest that the router can keep track
of which nodes the endpoint has been communicating with to not wake up
sleeping remotes unecessarily, but implementation of this suggestion is
left for the future.

Cc: Courtney Cavin <ccavin@gmail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/qrtr/qrtr.c |   28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

--- a/net/qrtr/qrtr.c
+++ b/net/qrtr/qrtr.c
@@ -112,6 +112,7 @@ struct qrtr_node {
 };
 
 static int qrtr_local_enqueue(struct qrtr_node *node, struct sk_buff *skb);
+static int qrtr_bcast_enqueue(struct qrtr_node *node, struct sk_buff *skb);
 
 /* Release node resources and free the node.
  *
@@ -312,6 +313,26 @@ static struct sk_buff *qrtr_alloc_local_
 	return skb;
 }
 
+static struct sk_buff *qrtr_alloc_del_client(struct sockaddr_qrtr *sq)
+{
+	const int pkt_len = 20;
+	struct sk_buff *skb;
+	__le32 *buf;
+
+	skb = qrtr_alloc_ctrl_packet(QRTR_TYPE_DEL_CLIENT, pkt_len,
+				     sq->sq_node, QRTR_NODE_BCAST);
+	if (!skb)
+		return NULL;
+
+	buf = (__le32 *)skb_put(skb, pkt_len);
+	memset(buf, 0, pkt_len);
+	buf[0] = cpu_to_le32(QRTR_TYPE_DEL_CLIENT);
+	buf[1] = cpu_to_le32(sq->sq_node);
+	buf[2] = cpu_to_le32(sq->sq_port);
+
+	return skb;
+}
+
 static struct qrtr_sock *qrtr_port_lookup(int port);
 static void qrtr_port_put(struct qrtr_sock *ipc);
 
@@ -448,8 +469,15 @@ static void qrtr_port_put(struct qrtr_so
 /* Remove port assignment. */
 static void qrtr_port_remove(struct qrtr_sock *ipc)
 {
+	struct sk_buff *skb;
 	int port = ipc->us.sq_port;
 
+	skb = qrtr_alloc_del_client(&ipc->us);
+	if (skb) {
+		skb_set_owner_w(skb, &ipc->sk);
+		qrtr_bcast_enqueue(NULL, skb);
+	}
+
 	if (port == QRTR_PORT_CTRL)
 		port = 0;