tipc: relocate common functions from media to bearer

Currently, registering a TIPC stack handler in the network device layer
is done twice, once for Ethernet (eth_media) and Infiniband (ib_media)
repectively. But, as this registration is not media specific, we can
avoid some code duplication by moving the registering function to
the generic bearer layer, to the file bearer.c, and call it only once.
The same is true for the network device event notifier.

As a side effect, the two workqueues we are using for for setting up/
cleaning up media can now be eliminated. Furthermore, the array for
storing the specific media type structs, media_array[], can be entirely
deleted.

Note that the eth_started and ib_started flags were removed during the
code relocation.  There is now only one call to bearer_setup and
bearer_cleanup, and these can logically not race against each other.

Despite its size, this cleanup work incurs no functional changes in TIPC.
In particular, it should be noted that the sequence ordering of received
packets is unaffected by this change, since packet reception never was
subject to any work queue handling in the first place.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 104 insertions, 1 deletions

diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 2411bac2b8f9..e95e0b91ef30 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -367,7 +367,7 @@ exit:
 /**
  * tipc_reset_bearer - Reset all links established over this bearer
  */
-int tipc_reset_bearer(struct tipc_bearer *b_ptr)
+static int tipc_reset_bearer(struct tipc_bearer *b_ptr)
 {
 	struct tipc_link *l_ptr;
 	struct tipc_link *temp_l_ptr;
@@ -432,7 +432,110 @@ int tipc_disable_bearer(const char *name)
 	return res;
 }
 
+/**
+ * tipc_l2_rcv_msg - handle incoming TIPC message from an interface
+ * @buf: the received packet
+ * @dev: the net device that the packet was received on
+ * @pt: the packet_type structure which was used to register this handler
+ * @orig_dev: the original receive net device in case the device is a bond
+ *
+ * Accept only packets explicitly sent to this node, or broadcast packets;
+ * ignores packets sent using interface multicast, and traffic sent to other
+ * nodes (which can happen if interface is running in promiscuous mode).
+ */
+static int tipc_l2_rcv_msg(struct sk_buff *buf, struct net_device *dev,
+			   struct packet_type *pt, struct net_device *orig_dev)
+{
+	struct tipc_bearer *b_ptr;
+
+	if (!net_eq(dev_net(dev), &init_net)) {
+		kfree_skb(buf);
+		return NET_RX_DROP;
+	}
+
+	rcu_read_lock();
+	b_ptr = rcu_dereference(dev->tipc_ptr);
+	if (likely(b_ptr)) {
+		if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
+			buf->next = NULL;
+			tipc_recv_msg(buf, b_ptr);
+			rcu_read_unlock();
+			return NET_RX_SUCCESS;
+		}
+	}
+	rcu_read_unlock();
+
+	kfree_skb(buf);
+	return NET_RX_DROP;
+}
+
+/**
+ * tipc_l2_device_event - handle device events from network device
+ * @nb: the context of the notification
+ * @evt: the type of event
+ * @ptr: the net device that the event was on
+ *
+ * This function is called by the Ethernet driver in case of link
+ * change event.
+ */
+static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
+				void *ptr)
+{
+	struct tipc_bearer *b_ptr;
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 
+	if (!net_eq(dev_net(dev), &init_net))
+		return NOTIFY_DONE;
+
+	rcu_read_lock();
+	b_ptr = rcu_dereference(dev->tipc_ptr);
+	if (!b_ptr) {
+		rcu_read_unlock();
+		return NOTIFY_DONE;
+	}
+
+	b_ptr->mtu = dev->mtu;
+
+	switch (evt) {
+	case NETDEV_CHANGE:
+		if (netif_carrier_ok(dev))
+			break;
+	case NETDEV_DOWN:
+	case NETDEV_CHANGEMTU:
+	case NETDEV_CHANGEADDR:
+		tipc_reset_bearer(b_ptr);
+		break;
+	case NETDEV_UNREGISTER:
+	case NETDEV_CHANGENAME:
+		tipc_disable_bearer(b_ptr->name);
+		break;
+	}
+	rcu_read_unlock();
+
+	return NOTIFY_OK;
+}
+
+static struct packet_type tipc_packet_type __read_mostly = {
+	.type = __constant_htons(ETH_P_TIPC),
+	.func = tipc_l2_rcv_msg,
+};
+
+static struct notifier_block notifier = {
+	.notifier_call  = tipc_l2_device_event,
+	.priority	= 0,
+};
+
+int tipc_bearer_setup(void)
+{
+	dev_add_pack(&tipc_packet_type);
+	return register_netdevice_notifier(&notifier);
+}
+
+void tipc_bearer_cleanup(void)
+{
+	unregister_netdevice_notifier(&notifier);
+	dev_remove_pack(&tipc_packet_type);
+}
 
 void tipc_bearer_stop(void)
 {