net: bridge: add notifications for the bridge dev on vlan change

Currently the bridge device doesn't generate any notifications upon vlan
modifications on itself because it doesn't use the generic bridge
notifications.
With the recent changes we know if anything was modified in the vlan config
thus we can generate a notification when necessary for the bridge device
so add support to br_ifinfo_notify() similar to how other combined
functions are done - if port is present it takes precedence, otherwise
notify about the bridge. I've explicitly marked the locations where the
notification should be always for the port by setting bridge to NULL.
I've also taken the liberty to rearrange each modified function's local
variables in reverse xmas tree as well.

Signed-off-by: Nikolay Aleksandrov <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/bridge/br.c

···
 	/* Events that may cause spanning tree to refresh */
 	if (event == NETDEV_CHANGEADDR || event == NETDEV_UP ||
 	    event == NETDEV_CHANGE || event == NETDEV_DOWN)
-		br_ifinfo_notify(RTM_NEWLINK, p);
+		br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 
 	return NOTIFY_DONE;
 }

net/bridge/br_if.c

···
 	br_stp_disable_port(p);
 	spin_unlock_bh(&br->lock);
 
-	br_ifinfo_notify(RTM_DELLINK, p);
+	br_ifinfo_notify(RTM_DELLINK, NULL, p);
 
 	list_del_rcu(&p->list);
 	if (netdev_get_fwd_headroom(dev) == br->dev->needed_headroom)
···
 		br_stp_enable_port(p);
 	spin_unlock_bh(&br->lock);
 
-	br_ifinfo_notify(RTM_NEWLINK, p);
+	br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 
 	if (changed_addr)
 		call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);

net/bridge/br_ioctl.c

···
 
 	if (!ret) {
 		if (p)
-			br_ifinfo_notify(RTM_NEWLINK, p);
+			br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 		else
 			netdev_state_change(br->dev);
 	}

net/bridge/br_netlink.c

···
  * Contains port and master info as well as carrier and bridge state.
  */
 static int br_fill_ifinfo(struct sk_buff *skb,
-			  struct net_bridge_port *port,
+			  const struct net_bridge_port *port,
 			  u32 pid, u32 seq, int event, unsigned int flags,
 			  u32 filter_mask, const struct net_device *dev)
 {
+	u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN;
 	struct net_bridge *br;
 	struct ifinfomsg *hdr;
 	struct nlmsghdr *nlh;
-	u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN;
 
 	if (port)
 		br = port->br;
···
 	return -EMSGSIZE;
 }
 
-/*
- * Notify listeners of a change in port information
- */
-void br_ifinfo_notify(int event, struct net_bridge_port *port)
+/* Notify listeners of a change in bridge or port information */
+void br_ifinfo_notify(int event, const struct net_bridge *br,
+		      const struct net_bridge_port *port)
 {
-	struct net *net;
+	u32 filter = RTEXT_FILTER_BRVLAN_COMPRESSED;
+	struct net_device *dev;
 	struct sk_buff *skb;
 	int err = -ENOBUFS;
-	u32 filter = RTEXT_FILTER_BRVLAN_COMPRESSED;
+	struct net *net;
+	u16 port_no = 0;
 
-	if (!port)
+	if (WARN_ON(!port && !br))
 		return;
 
-	net = dev_net(port->dev);
-	br_debug(port->br, "port %u(%s) event %d\n",
-		 (unsigned int)port->port_no, port->dev->name, event);
+	if (port) {
+		dev = port->dev;
+		br = port->br;
+		port_no = port->port_no;
+	} else {
+		dev = br->dev;
+	}
 
-	skb = nlmsg_new(br_nlmsg_size(port->dev, filter), GFP_ATOMIC);
+	net = dev_net(dev);
+	br_debug(br, "port %u(%s) event %d\n", port_no, dev->name, event);
+
+	skb = nlmsg_new(br_nlmsg_size(dev, filter), GFP_ATOMIC);
 	if (skb == NULL)
 		goto errout;
 
-	err = br_fill_ifinfo(skb, port, 0, 0, event, 0, filter, port->dev);
+	err = br_fill_ifinfo(skb, port, 0, 0, event, 0, filter, dev);
 	if (err < 0) {
 		/* -EMSGSIZE implies BUG in br_nlmsg_size() */
 		WARN_ON(err == -EMSGSIZE);
···
 errout:
 	rtnl_set_sk_err(net, RTNLGRP_LINK, err);
 }
-
 
 /*
  * Dump information about all ports, in response to GETLINK
···
 /* Change state and parameters on port. */
 int br_setlink(struct net_device *dev, struct nlmsghdr *nlh, u16 flags)
 {
+	struct net_bridge *br = (struct net_bridge *)netdev_priv(dev);
+	struct nlattr *tb[IFLA_BRPORT_MAX + 1];
+	struct net_bridge_port *p;
 	struct nlattr *protinfo;
 	struct nlattr *afspec;
-	struct net_bridge_port *p;
-	struct nlattr *tb[IFLA_BRPORT_MAX + 1];
 	bool changed = false;
 	int err = 0;
 
···
 		changed = true;
 	}
 
-	if (afspec) {
-		err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
-				afspec, RTM_SETLINK, &changed);
-	}
+	if (afspec)
+		err = br_afspec(br, p, afspec, RTM_SETLINK, &changed);
 
 	if (changed)
-		br_ifinfo_notify(RTM_NEWLINK, p);
+		br_ifinfo_notify(RTM_NEWLINK, br, p);
 out:
 	return err;
 }
···
 /* Delete port information */
 int br_dellink(struct net_device *dev, struct nlmsghdr *nlh, u16 flags)
 {
-	struct nlattr *afspec;
+	struct net_bridge *br = (struct net_bridge *)netdev_priv(dev);
 	struct net_bridge_port *p;
+	struct nlattr *afspec;
 	bool changed = false;
 	int err = 0;
 
···
 	if (!p && !(dev->priv_flags & IFF_EBRIDGE))
 		return -EINVAL;
 
-	err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
-			afspec, RTM_DELLINK, &changed);
+	err = br_afspec(br, p, afspec, RTM_DELLINK, &changed);
 	if (changed)
 		/* Send RTM_NEWLINK because userspace
 		 * expects RTM_NEWLINK for vlan dels
 		 */
-		br_ifinfo_notify(RTM_NEWLINK, p);
+		br_ifinfo_notify(RTM_NEWLINK, br, p);
 
 	return err;
 }

net/bridge/br_private.h

···
 extern struct rtnl_link_ops br_link_ops;
 int br_netlink_init(void);
 void br_netlink_fini(void);
-void br_ifinfo_notify(int event, struct net_bridge_port *port);
+void br_ifinfo_notify(int event, const struct net_bridge *br,
+		      const struct net_bridge_port *port);
 int br_setlink(struct net_device *dev, struct nlmsghdr *nlmsg, u16 flags);
 int br_dellink(struct net_device *dev, struct nlmsghdr *nlmsg, u16 flags);
 int br_getlink(struct sk_buff *skb, u32 pid, u32 seq, struct net_device *dev,

net/bridge/br_stp.c

···
 		  (unsigned int) p->port_no, p->dev->name);
 
 	br_set_state(p, BR_STATE_LISTENING);
-	br_ifinfo_notify(RTM_NEWLINK, p);
+	br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 
 	if (br->forward_delay > 0)
 		mod_timer(&p->forward_delay_timer, jiffies + br->forward_delay);
···
 			br_topology_change_detection(p->br);
 
 		br_set_state(p, BR_STATE_BLOCKING);
-		br_ifinfo_notify(RTM_NEWLINK, p);
+		br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 
 		del_timer(&p->forward_delay_timer);
 	}
···
 	else
 		br_set_state(p, BR_STATE_LEARNING);
 
-	br_ifinfo_notify(RTM_NEWLINK, p);
+	br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 
 	if (br->forward_delay != 0)
 		mod_timer(&p->forward_delay_timer, jiffies + br->forward_delay);

net/bridge/br_stp_if.c

···
 {
 	br_init_port(p);
 	br_port_state_selection(p->br);
-	br_ifinfo_notify(RTM_NEWLINK, p);
+	br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 }
 
 /* called under bridge lock */
···
 	p->topology_change_ack = 0;
 	p->config_pending = 0;
 
-	br_ifinfo_notify(RTM_NEWLINK, p);
+	br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 
 	del_timer(&p->message_age_timer);
 	del_timer(&p->forward_delay_timer);

net/bridge/br_stp_timer.c

···
 		netif_carrier_on(br->dev);
 	}
 	rcu_read_lock();
-	br_ifinfo_notify(RTM_NEWLINK, p);
+	br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 	rcu_read_unlock();
 	spin_unlock(&br->lock);
 }

net/bridge/br_sysfs_if.c

···
 			ret = brport_attr->store(p, val);
 			spin_unlock_bh(&p->br->lock);
 			if (!ret) {
-				br_ifinfo_notify(RTM_NEWLINK, p);
+				br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 				ret = count;
 			}
 		}