Merge branch 'qrtr-features'

Bjorn Andersson says:

====================
Missing QRTR features

The QMUX specification covers packet routing as well as service life cycle and
discovery. The current implementation of qrtr supports the prior part, but in
order to fully implement service management on-top a few more parts are needed.

The first patch in the series serves the purpose of reducing duplication in
patch two and three.

The second and third patch adds two qrtr-level notifications required by the
specification, in order to notify local and remote service controllers about
dying clients.

The last patch serves the purpose of notifying local clients about the presence
of a local service register, allowing them to register services as well as
querying for remote registered services.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

net/qrtr/qrtr.c

@@ -111,6 +111,9 @@ struct qrtr_node {
 	struct list_head item;
 };
 
+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.
  *
  * Do not call directly, use qrtr_node_release.  To be used with
@@ -245,14 +248,11 @@ int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len)
 }
 EXPORT_SYMBOL_GPL(qrtr_endpoint_post);
 
-/* Allocate and construct a resume-tx packet. */
-static struct sk_buff *qrtr_alloc_resume_tx(u32 src_node,
-					    u32 dst_node, u32 port)
+static struct sk_buff *qrtr_alloc_ctrl_packet(u32 type, size_t pkt_len,
+					      u32 src_node, u32 dst_node)
 {
-	const int pkt_len = 20;
 	struct qrtr_hdr *hdr;
 	struct sk_buff *skb;
-	__le32 *buf;
 
 	skb = alloc_skb(QRTR_HDR_SIZE + pkt_len, GFP_KERNEL);
 	if (!skb)
@@ -261,7 +261,7 @@ static struct sk_buff *qrtr_alloc_resume_tx(u32 src_node,
 
 	hdr = (struct qrtr_hdr *)skb_put(skb, QRTR_HDR_SIZE);
 	hdr->version = cpu_to_le32(QRTR_PROTO_VER);
-	hdr->type = cpu_to_le32(QRTR_TYPE_RESUME_TX);
+	hdr->type = cpu_to_le32(type);
 	hdr->src_node_id = cpu_to_le32(src_node);
 	hdr->src_port_id = cpu_to_le32(QRTR_PORT_CTRL);
 	hdr->confirm_rx = cpu_to_le32(0);
@@ -269,6 +269,22 @@ static struct sk_buff *qrtr_alloc_resume_tx(u32 src_node,
 	hdr->dst_node_id = cpu_to_le32(dst_node);
 	hdr->dst_port_id = cpu_to_le32(QRTR_PORT_CTRL);
 
+	return skb;
+}
+
+/* Allocate and construct a resume-tx packet. */
+static struct sk_buff *qrtr_alloc_resume_tx(u32 src_node,
+					    u32 dst_node, u32 port)
+{
+	const int pkt_len = 20;
+	struct sk_buff *skb;
+	__le32 *buf;
+
+	skb = qrtr_alloc_ctrl_packet(QRTR_TYPE_RESUME_TX, pkt_len,
+				     src_node, dst_node);
+	if (!skb)
+		return NULL;
+
 	buf = (__le32 *)skb_put(skb, pkt_len);
 	memset(buf, 0, pkt_len);
 	buf[0] = cpu_to_le32(QRTR_TYPE_RESUME_TX);
@@ -278,6 +294,45 @@ static struct sk_buff *qrtr_alloc_resume_tx(u32 src_node,
 	return skb;
 }
 
+/* Allocate and construct a BYE message to signal remote termination */
+static struct sk_buff *qrtr_alloc_local_bye(u32 src_node)
+{
+	const int pkt_len = 20;
+	struct sk_buff *skb;
+	__le32 *buf;
+
+	skb = qrtr_alloc_ctrl_packet(QRTR_TYPE_BYE, pkt_len,
+				     src_node, qrtr_local_nid);
+	if (!skb)
+		return NULL;
+
+	buf = (__le32 *)skb_put(skb, pkt_len);
+	memset(buf, 0, pkt_len);
+	buf[0] = cpu_to_le32(QRTR_TYPE_BYE);
+
+	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);
 
@@ -369,11 +424,17 @@ EXPORT_SYMBOL_GPL(qrtr_endpoint_register);
 void qrtr_endpoint_unregister(struct qrtr_endpoint *ep)
 {
 	struct qrtr_node *node = ep->node;
+	struct sk_buff *skb;
 
 	mutex_lock(&node->ep_lock);
 	node->ep = NULL;
 	mutex_unlock(&node->ep_lock);
 
+	/* Notify the local controller about the event */
+	skb = qrtr_alloc_local_bye(node->nid);
+	if (skb)
+		qrtr_local_enqueue(NULL, skb);
+
 	qrtr_node_release(node);
 	ep->node = NULL;
 }
@@ -408,8 +469,15 @@ static void qrtr_port_put(struct qrtr_sock *ipc)
 /* 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;
 
@@ -462,6 +530,26 @@ static int qrtr_port_assign(struct qrtr_sock *ipc, int *port)
 	return 0;
 }
 
+/* Reset all non-control ports */
+static void qrtr_reset_ports(void)
+{
+	struct qrtr_sock *ipc;
+	int id;
+
+	mutex_lock(&qrtr_port_lock);
+	idr_for_each_entry(&qrtr_ports, ipc, id) {
+		/* Don't reset control port */
+		if (id == 0)
+			continue;
+
+		sock_hold(&ipc->sk);
+		ipc->sk.sk_err = ENETRESET;
+		wake_up_interruptible(sk_sleep(&ipc->sk));
+		sock_put(&ipc->sk);
+	}
+	mutex_unlock(&qrtr_port_lock);
+}
+
 /* Bind socket to address.
  *
  * Socket should be locked upon call.
@@ -490,6 +578,10 @@ static int __qrtr_bind(struct socket *sock,
 
 	sock_reset_flag(sk, SOCK_ZAPPED);
 
+	/* Notify all open ports about the new controller */
+	if (port == QRTR_PORT_CTRL)
+		qrtr_reset_ports();
+
 	return 0;
 }