net: bridge: vlan: add support for global options

We can have two types of vlan options depending on context:
 - per-device vlan options (split in per-bridge and per-port)
 - global vlan options

The second type wasn't supported in the bridge until now, but we need
them for per-vlan multicast support, per-vlan STP support and other
options which require global vlan context. They are contained in the global
bridge vlan context even if the vlan is not configured on the bridge device
itself. This patch adds initial netlink attributes and support for setting
these global vlan options, they can only be set (RTM_NEWVLAN) and the
operation must use the bridge device. Since there are no such options yet
it shouldn't have any functional effect.

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

include/uapi/linux/if_bridge.h

@@ -485,10 +485,15 @@ enum {
  *     [BRIDGE_VLANDB_ENTRY_INFO]
  *     ...
  * }
+ * [BRIDGE_VLANDB_GLOBAL_OPTIONS] = {
+ *     [BRIDGE_VLANDB_GOPTS_ID]
+ *     ...
+ * }
  */
 enum {
 	BRIDGE_VLANDB_UNSPEC,
 	BRIDGE_VLANDB_ENTRY,
+	BRIDGE_VLANDB_GLOBAL_OPTIONS,
 	__BRIDGE_VLANDB_MAX,
 };
 #define BRIDGE_VLANDB_MAX (__BRIDGE_VLANDB_MAX - 1)
@@ -538,6 +543,14 @@ enum {
 };
 #define BRIDGE_VLANDB_STATS_MAX (__BRIDGE_VLANDB_STATS_MAX - 1)
 
+enum {
+	BRIDGE_VLANDB_GOPTS_UNSPEC,
+	BRIDGE_VLANDB_GOPTS_ID,
+	BRIDGE_VLANDB_GOPTS_RANGE,
+	__BRIDGE_VLANDB_GOPTS_MAX
+};
+#define BRIDGE_VLANDB_GOPTS_MAX (__BRIDGE_VLANDB_GOPTS_MAX - 1)
+
 /* Bridge multicast database attributes
  * [MDBA_MDB] = {
  *     [MDBA_MDB_ENTRY] = {

net/bridge/br_private.h

@@ -1592,6 +1592,10 @@ int br_vlan_process_options(const struct net_bridge *br,
 			    struct net_bridge_vlan *range_end,
 			    struct nlattr **tb,
 			    struct netlink_ext_ack *extack);
+int br_vlan_rtm_process_global_options(struct net_device *dev,
+				       const struct nlattr *attr,
+				       int cmd,
+				       struct netlink_ext_ack *extack);
 
 /* vlan state manipulation helpers using *_ONCE to annotate lock-free access */
 static inline u8 br_vlan_get_state(const struct net_bridge_vlan *v)

net/bridge/br_vlan.c

@@ -2203,12 +2203,22 @@ static int br_vlan_rtm_process(struct sk_buff *skb, struct nlmsghdr *nlh,
 	}
 
 	nlmsg_for_each_attr(attr, nlh, sizeof(*bvm), rem) {
-		if (nla_type(attr) != BRIDGE_VLANDB_ENTRY)
+		switch (nla_type(attr)) {
+		case BRIDGE_VLANDB_ENTRY:
+			err = br_vlan_rtm_process_one(dev, attr,
+						      nlh->nlmsg_type,
+						      extack);
+			break;
+		case BRIDGE_VLANDB_GLOBAL_OPTIONS:
+			err = br_vlan_rtm_process_global_options(dev, attr,
+								 nlh->nlmsg_type,
+								 extack);
+			break;
+		default:
 			continue;
+		}
 
 		vlans++;
-		err = br_vlan_rtm_process_one(dev, attr, nlh->nlmsg_type,
-					      extack);
 		if (err)
 			break;
 	}

net/bridge/br_vlan_options.c

@@ -258,3 +258,88 @@ int br_vlan_process_options(const struct net_bridge *br,
 
 	return err;
 }
+
+static int br_vlan_process_global_one_opts(const struct net_bridge *br,
+					   struct net_bridge_vlan_group *vg,
+					   struct net_bridge_vlan *v,
+					   struct nlattr **tb,
+					   bool *changed,
+					   struct netlink_ext_ack *extack)
+{
+	*changed = false;
+	return 0;
+}
+
+static const struct nla_policy br_vlan_db_gpol[BRIDGE_VLANDB_GOPTS_MAX + 1] = {
+	[BRIDGE_VLANDB_GOPTS_ID]	= { .type = NLA_U16 },
+	[BRIDGE_VLANDB_GOPTS_RANGE]	= { .type = NLA_U16 },
+};
+
+int br_vlan_rtm_process_global_options(struct net_device *dev,
+				       const struct nlattr *attr,
+				       int cmd,
+				       struct netlink_ext_ack *extack)
+{
+	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;
+
+	if (cmd != RTM_NEWVLAN) {
+		NL_SET_ERR_MSG_MOD(extack, "Global vlan options support only set operation");
+		return -EINVAL;
+	}
+	if (!netif_is_bridge_master(dev)) {
+		NL_SET_ERR_MSG_MOD(extack, "Global vlan options can only be set on bridge device");
+		return -EINVAL;
+	}
+	br = netdev_priv(dev);
+	vg = br_vlan_group(br);
+	if (WARN_ON(!vg))
+		return -ENODEV;
+
+	err = nla_parse_nested(tb, BRIDGE_VLANDB_GOPTS_MAX, attr,
+			       br_vlan_db_gpol, extack);
+	if (err)
+		return err;
+
+	if (!tb[BRIDGE_VLANDB_GOPTS_ID]) {
+		NL_SET_ERR_MSG_MOD(extack, "Missing vlan entry id");
+		return -EINVAL;
+	}
+	vid = nla_get_u16(tb[BRIDGE_VLANDB_GOPTS_ID]);
+	if (!br_vlan_valid_id(vid, extack))
+		return -EINVAL;
+
+	if (tb[BRIDGE_VLANDB_GOPTS_RANGE]) {
+		vid_range = nla_get_u16(tb[BRIDGE_VLANDB_GOPTS_RANGE]);
+		if (!br_vlan_valid_id(vid_range, extack))
+			return -EINVAL;
+		if (vid >= vid_range) {
+			NL_SET_ERR_MSG_MOD(extack, "End vlan id is less than or equal to start vlan id");
+			return -EINVAL;
+		}
+	} else {
+		vid_range = vid;
+	}
+
+	for (; vid <= vid_range; vid++) {
+		bool changed = false;
+
+		v = br_vlan_find(vg, vid);
+		if (!v) {
+			NL_SET_ERR_MSG_MOD(extack, "Vlan in range doesn't exist, can't process global options");
+			err = -ENOENT;
+			break;
+		}
+
+		err = br_vlan_process_global_one_opts(br, vg, v, tb, &changed,
+						      extack);
+		if (err)
+			break;
+	}
+
+	return err;
+}