net: bridge: vlan: notify when global options change

Add support for global options notifications. They use only RTM_NEWVLAN
since global options can only be set and are contained in a separate
vlan global options attribute. Notifications are compressed in ranges
where possible, i.e. the sequential vlan options are equal.
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_vlan_options.c

@@ -290,6 +290,57 @@ bool br_vlan_global_opts_fill(struct sk_buff *skb, u16 vid, u16 vid_range,
 	return false;
 }
 
+static size_t rtnl_vlan_global_opts_nlmsg_size(void)
+{
+	return NLMSG_ALIGN(sizeof(struct br_vlan_msg))
+		+ nla_total_size(0) /* BRIDGE_VLANDB_GLOBAL_OPTIONS */
+		+ nla_total_size(sizeof(u16)) /* BRIDGE_VLANDB_GOPTS_ID */
+		+ nla_total_size(sizeof(u16)); /* BRIDGE_VLANDB_GOPTS_RANGE */
+}
+
+static void br_vlan_global_opts_notify(const struct net_bridge *br,
+				       u16 vid, u16 vid_range)
+{
+	struct net_bridge_vlan *v;
+	struct br_vlan_msg *bvm;
+	struct nlmsghdr *nlh;
+	struct sk_buff *skb;
+	int err = -ENOBUFS;
+
+	/* right now notifications are done only with rtnl held */
+	ASSERT_RTNL();
+
+	skb = nlmsg_new(rtnl_vlan_global_opts_nlmsg_size(), GFP_KERNEL);
+	if (!skb)
+		goto out_err;
+
+	err = -EMSGSIZE;
+	nlh = nlmsg_put(skb, 0, 0, RTM_NEWVLAN, sizeof(*bvm), 0);
+	if (!nlh)
+		goto out_err;
+	bvm = nlmsg_data(nlh);
+	memset(bvm, 0, sizeof(*bvm));
+	bvm->family = AF_BRIDGE;
+	bvm->ifindex = br->dev->ifindex;
+
+	/* need to find the vlan due to flags/options */
+	v = br_vlan_find(br_vlan_group(br), vid);
+	if (!v)
+		goto out_kfree;
+
+	if (!br_vlan_global_opts_fill(skb, vid, vid_range, v))
+		goto out_err;
+
+	nlmsg_end(skb, nlh);
+	rtnl_notify(skb, dev_net(br->dev), 0, RTNLGRP_BRVLAN, NULL, GFP_KERNEL);
+	return;
+
+out_err:
+	rtnl_set_sk_err(dev_net(br->dev), RTNLGRP_BRVLAN, err);
+out_kfree:
+	kfree_skb(skb);
+}
+
 static int br_vlan_process_global_one_opts(const struct net_bridge *br,
 					   struct net_bridge_vlan_group *vg,
 					   struct net_bridge_vlan *v,
@@ -311,9 +362,9 @@ int br_vlan_rtm_process_global_options(struct net_device *dev,
 				       int cmd,
 				       struct netlink_ext_ack *extack)
 {
+	struct net_bridge_vlan *v, *curr_start = NULL, *curr_end = NULL;
 	struct nlattr *tb[BRIDGE_VLANDB_GOPTS_MAX + 1];
 	struct net_bridge_vlan_group *vg;
-	struct net_bridge_vlan *v;
 	u16 vid, vid_range = 0;
 	struct net_bridge *br;
 	int err = 0;
@@ -370,7 +421,34 @@ int br_vlan_rtm_process_global_options(struct net_device *dev,
 						      extack);
 		if (err)
 			break;
+
+		if (changed) {
+			/* vlan options changed, check for range */
+			if (!curr_start) {
+				curr_start = v;
+				curr_end = v;
+				continue;
+			}
+
+			if (!br_vlan_global_opts_can_enter_range(v, curr_end)) {
+				br_vlan_global_opts_notify(br, curr_start->vid,
+							   curr_end->vid);
+				curr_start = v;
+			}
+			curr_end = v;
+		} else {
+			/* nothing changed and nothing to notify yet */
+			if (!curr_start)
+				continue;
+
+			br_vlan_global_opts_notify(br, curr_start->vid,
+						   curr_end->vid);
+			curr_start = NULL;
+			curr_end = NULL;
+		}
 	}
+	if (curr_start)
+		br_vlan_global_opts_notify(br, curr_start->vid, curr_end->vid);
 
 	return err;
 }