net: bridge: vlan: add basic option dumping support

We'll be dumping the options for the whole range if they're equal. The
first range vlan will be used to extract the options. The commit doesn't
change anything yet it just adds the skeleton for the support. The dump
will happen when the first option is added.

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/Makefile

@@ -20,7 +20,7 @@ obj-$(CONFIG_BRIDGE_NETFILTER) += br_netfilter.o
 
 bridge-$(CONFIG_BRIDGE_IGMP_SNOOPING) += br_multicast.o br_mdb.o
 
-bridge-$(CONFIG_BRIDGE_VLAN_FILTERING) += br_vlan.o br_vlan_tunnel.o
+bridge-$(CONFIG_BRIDGE_VLAN_FILTERING) += br_vlan.o br_vlan_tunnel.o br_vlan_options.o
 
 bridge-$(CONFIG_NET_SWITCHDEV) += br_switchdev.o
 

net/bridge/br_private.h

@@ -1191,6 +1191,14 @@ static inline void br_vlan_notify(const struct net_bridge *br,
 }
 #endif
 
+/* br_vlan_options.c */
+#ifdef CONFIG_BRIDGE_VLAN_FILTERING
+bool br_vlan_opts_eq(const struct net_bridge_vlan *v1,
+		     const struct net_bridge_vlan *v2);
+bool br_vlan_opts_fill(struct sk_buff *skb, const struct net_bridge_vlan *v);
+size_t br_vlan_opts_nl_size(void);
+#endif
+
 struct nf_br_ops {
 	int (*br_dev_xmit_hook)(struct sk_buff *skb);
 };

net/bridge/br_vlan.c

@@ -1547,7 +1547,9 @@ void br_vlan_port_event(struct net_bridge_port *p, unsigned long event)
 	}
 }
 
+/* v_opts is used to dump the options which must be equal in the whole range */
 static bool br_vlan_fill_vids(struct sk_buff *skb, u16 vid, u16 vid_range,
+			      const struct net_bridge_vlan *v_opts,
 			      u16 flags)
 {
 	struct bridge_vlan_info info;
@@ -1572,6 +1574,9 @@ static bool br_vlan_fill_vids(struct sk_buff *skb, u16 vid, u16 vid_range,
 	    nla_put_u16(skb, BRIDGE_VLANDB_ENTRY_RANGE, vid_range))
 		goto out_err;
 
+	if (v_opts && !br_vlan_opts_fill(skb, v_opts))
+		goto out_err;
+
 	nla_nest_end(skb, nest);
 
 	return true;
@@ -1586,7 +1591,8 @@ static size_t rtnl_vlan_nlmsg_size(void)
 	return NLMSG_ALIGN(sizeof(struct br_vlan_msg))
 		+ nla_total_size(0) /* BRIDGE_VLANDB_ENTRY */
 		+ nla_total_size(sizeof(u16)) /* BRIDGE_VLANDB_ENTRY_RANGE */
-		+ nla_total_size(sizeof(struct bridge_vlan_info)); /* BRIDGE_VLANDB_ENTRY_INFO */
+		+ nla_total_size(sizeof(struct bridge_vlan_info)) /* BRIDGE_VLANDB_ENTRY_INFO */
+		+ br_vlan_opts_nl_size(); /* bridge vlan options */
 }
 
 void br_vlan_notify(const struct net_bridge *br,
@@ -1595,7 +1601,7 @@ void br_vlan_notify(const struct net_bridge *br,
 		    int cmd)
 {
 	struct net_bridge_vlan_group *vg;
-	struct net_bridge_vlan *v;
+	struct net_bridge_vlan *v = NULL;
 	struct br_vlan_msg *bvm;
 	struct nlmsghdr *nlh;
 	struct sk_buff *skb;
@@ -1647,7 +1653,7 @@ void br_vlan_notify(const struct net_bridge *br,
 		goto out_kfree;
 	}
 
-	if (!br_vlan_fill_vids(skb, vid, vid_range, flags))
+	if (!br_vlan_fill_vids(skb, vid, vid_range, v, flags))
 		goto out_err;
 
 	nlmsg_end(skb, nlh);
@@ -1665,7 +1671,8 @@ static bool br_vlan_can_enter_range(const struct net_bridge_vlan *v_curr,
 				    const struct net_bridge_vlan *range_end)
 {
 	return v_curr->vid - range_end->vid == 1 &&
-	       range_end->flags == v_curr->flags;
+	       range_end->flags == v_curr->flags &&
+	       br_vlan_opts_eq(v_curr, range_end);
 }
 
 static int br_vlan_dump_dev(const struct net_device *dev,
@@ -1729,7 +1736,8 @@ static int br_vlan_dump_dev(const struct net_device *dev,
 			u16 flags = br_vlan_flags(range_start, pvid);
 
 			if (!br_vlan_fill_vids(skb, range_start->vid,
-					       range_end->vid, flags)) {
+					       range_end->vid, range_start,
+					       flags)) {
 				err = -EMSGSIZE;
 				break;
 			}
@@ -1748,7 +1756,7 @@ static int br_vlan_dump_dev(const struct net_device *dev,
 	 */
 	if (!err && range_start &&
 	    !br_vlan_fill_vids(skb, range_start->vid, range_end->vid,
-			       br_vlan_flags(range_start, pvid)))
+			       range_start, br_vlan_flags(range_start, pvid)))
 		err = -EMSGSIZE;
 
 	cb->args[1] = err ? idx : 0;

net/bridge/br_vlan_options.c

@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2020, Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/slab.h>
+
+#include "br_private.h"
+
+/* check if the options between two vlans are equal */
+bool br_vlan_opts_eq(const struct net_bridge_vlan *v1,
+		     const struct net_bridge_vlan *v2)
+{
+	return true;
+}
+
+bool br_vlan_opts_fill(struct sk_buff *skb, const struct net_bridge_vlan *v)
+{
+	return true;
+}
+
+size_t br_vlan_opts_nl_size(void)
+{
+	return 0;
+}