bridge: vlan: add per-vlan struct and move to rhashtables

This patch changes the bridge vlan implementation to use rhashtables
instead of bitmaps. The main motivation behind this change is that we
need extensible per-vlan structures (both per-port and global) so more
advanced features can be introduced and the vlan support can be
extended. I've tried to break this up but the moment net_port_vlans is
changed and the whole API goes away, thus this is a larger patch.
A few short goals of this patch are:
- Extensible per-vlan structs stored in rhashtables and a sorted list
- Keep user-visible behaviour (compressed vlans etc)
- Keep fastpath ingress/egress logic the same (optimizations to come
  later)

Here's a brief list of some of the new features we'd like to introduce:
- per-vlan counters
- vlan ingress/egress mapping
- per-vlan igmp configuration
- vlan priorities
- avoid fdb entries replication (e.g. local fdb scaling issues)

The structure is kept single for both global and per-port entries so to
avoid code duplication where possible and also because we'll soon introduce
"port0 / aka bridge as port" which should simplify things further
(thanks to Vlad for the suggestion!).

Now we have per-vlan global rhashtable (bridge-wide) and per-vlan port
rhashtable, if an entry is added to a port it'll get a pointer to its
global context so it can be quickly accessed later. There's also a
sorted vlan list which is used for stable walks and some user-visible
behaviour such as the vlan ranges, also for error paths.
VLANs are stored in a "vlan group" which currently contains the
rhashtable, sorted vlan list and the number of "real" vlan entries.
A good side-effect of this change is that it resembles how hw keeps
per-vlan data.
One important note after this change is that if a VLAN is being looked up
in the bridge's rhashtable for filtering purposes (or to check if it's an
existing usable entry, not just a global context) then the new helper
br_vlan_should_use() needs to be used if the vlan is found. In case the
lookup is done only with a port's vlan group, then this check can be
skipped.

Things tested so far:
- basic vlan ingress/egress
- pvids
- untagged vlans
- undef CONFIG_BRIDGE_VLAN_FILTERING
- adding/deleting vlans in different scenarios (with/without global ctx,
  while transmitting traffic, in ranges etc)
- loading/removing the module while having/adding/deleting vlans
- extracting bridge vlan information (user ABI), compressed requests
- adding/deleting fdbs on vlans
- bridge mac change, promisc mode
- default pvid change
- kmemleak ON during the whole time

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

1 files changed, 142 insertions, 49 deletions

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 74e99c7..cfe945f 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -20,6 +20,7 @@
 #include <net/route.h>
 #include <net/ip6_fib.h>
 #include <linux/if_vlan.h>
+#include <linux/rhashtable.h>
 
 #define BR_HASH_BITS 8
 #define BR_HASH_SIZE (1 << BR_HASH_BITS)
@@ -28,7 +29,6 @@
 
 #define BR_PORT_BITS	10
 #define BR_MAX_PORTS	(1<<BR_PORT_BITS)
-#define BR_VLAN_BITMAP_LEN	BITS_TO_LONGS(VLAN_N_VID)
 
 #define BR_VERSION	"2.3"
 
@@ -77,16 +77,58 @@ struct bridge_mcast_querier {
 };
 #endif
 
-struct net_port_vlans {
-	u16				port_idx;
-	u16				pvid;
+/**
+ * struct net_bridge_vlan - per-vlan entry
+ *
+ * @vnode: rhashtable member
+ * @vid: VLAN id
+ * @flags: bridge vlan flags
+ * @br: if MASTER flag set, this points to a bridge struct
+ * @port: if MASTER flag unset, this points to a port struct
+ * @refcnt: if MASTER flag set, this is bumped for each port referencing it
+ * @brvlan: if MASTER flag unset, this points to the global per-VLAN context
+ *          for this VLAN entry
+ * @vlist: sorted list of VLAN entries
+ * @rcu: used for entry destruction
+ *
+ * This structure is shared between the global per-VLAN entries contained in
+ * the bridge rhashtable and the local per-port per-VLAN entries contained in
+ * the port's rhashtable. The union entries should be interpreted depending on
+ * the entry flags that are set.
+ */
+struct net_bridge_vlan {
+	struct rhash_head		vnode;
+	u16				vid;
+	u16				flags;
 	union {
-		struct net_bridge_port		*port;
-		struct net_bridge		*br;
-	}				parent;
+		struct net_bridge	*br;
+		struct net_bridge_port	*port;
+	};
+	union {
+		atomic_t		refcnt;
+		struct net_bridge_vlan	*brvlan;
+	};
+	struct list_head		vlist;
+
 	struct rcu_head			rcu;
-	unsigned long			vlan_bitmap[BR_VLAN_BITMAP_LEN];
-	unsigned long			untagged_bitmap[BR_VLAN_BITMAP_LEN];
+};
+
+/**
+ * struct net_bridge_vlan_group
+ *
+ * @vlan_hash: VLAN entry rhashtable
+ * @vlan_list: sorted VLAN entry list
+ * @num_vlans: number of total VLAN entries
+ *
+ * IMPORTANT: Be careful when checking if there're VLAN entries using list
+ *            primitives because the bridge can have entries in its list which
+ *            are just for global context but not for filtering, i.e. they have
+ *            the master flag set but not the brentry flag. If you have to check
+ *            if there're "real" entries in the bridge please test @num_vlans
+ */
+struct net_bridge_vlan_group {
+	struct rhashtable		vlan_hash;
+	struct list_head		vlan_list;
 	u16				num_vlans;
 };
 
@@ -185,7 +227,8 @@ struct net_bridge_port
 	struct netpoll			*np;
 #endif
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
-	struct net_port_vlans __rcu	*vlan_info;
+	struct net_bridge_vlan_group	*vlgrp;
+	u16				pvid;
 #endif
 };
 
@@ -293,10 +336,11 @@ struct net_bridge
 	struct kobject			*ifobj;
 	u32				auto_cnt;
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
+	struct net_bridge_vlan_group	*vlgrp;
 	u8				vlan_enabled;
 	__be16				vlan_proto;
 	u16				default_pvid;
-	struct net_port_vlans __rcu	*vlan_info;
+	u16				pvid;
 #endif
 };
 
@@ -344,6 +388,31 @@ static inline int br_is_root_bridge(const struct net_bridge *br)
 	return !memcmp(&br->bridge_id, &br->designated_root, 8);
 }
 
+/* check if a VLAN entry is global */
+static inline bool br_vlan_is_master(const struct net_bridge_vlan *v)
+{
+	return v->flags & BRIDGE_VLAN_INFO_MASTER;
+}
+
+/* check if a VLAN entry is used by the bridge */
+static inline bool br_vlan_is_brentry(const struct net_bridge_vlan *v)
+{
+	return v->flags & BRIDGE_VLAN_INFO_BRENTRY;
+}
+
+/* check if we should use the vlan entry is usable */
+static inline bool br_vlan_should_use(const struct net_bridge_vlan *v)
+{
+	if (br_vlan_is_master(v)) {
+		if (br_vlan_is_brentry(v))
+			return true;
+		else
+			return false;
+	}
+
+	return true;
+}
+
 /* br_device.c */
 void br_dev_setup(struct net_device *dev);
 void br_dev_delete(struct net_device *dev, struct list_head *list);
@@ -601,18 +670,19 @@ static inline void br_mdb_uninit(void)
 
 /* br_vlan.c */
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
-bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
-			struct sk_buff *skb, u16 *vid);
-bool br_allowed_egress(struct net_bridge *br, const struct net_port_vlans *v,
+bool br_allowed_ingress(struct net_bridge *br, struct sk_buff *skb, u16 *vid);
+bool nbp_allowed_ingress(struct net_bridge_port *p, struct sk_buff *skb,
+			 u16 *vid);
+bool br_allowed_egress(struct net_bridge_vlan_group *br,
 		       const struct sk_buff *skb);
 bool br_should_learn(struct net_bridge_port *p, struct sk_buff *skb, u16 *vid);
 struct sk_buff *br_handle_vlan(struct net_bridge *br,
-			       const struct net_port_vlans *v,
+			       struct net_bridge_vlan_group *vg,
 			       struct sk_buff *skb);
 int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags);
 int br_vlan_delete(struct net_bridge *br, u16 vid);
 void br_vlan_flush(struct net_bridge *br);
-bool br_vlan_find(struct net_bridge *br, u16 vid);
+struct net_bridge_vlan *br_vlan_find(struct net_bridge_vlan_group *vg, u16 vid);
 void br_recalculate_fwd_mask(struct net_bridge *br);
 int __br_vlan_filter_toggle(struct net_bridge *br, unsigned long val);
 int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val);
@@ -623,19 +693,19 @@ int br_vlan_set_default_pvid(struct net_bridge *br, unsigned long val);
 int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags);
 int nbp_vlan_delete(struct net_bridge_port *port, u16 vid);
 void nbp_vlan_flush(struct net_bridge_port *port);
-bool nbp_vlan_find(struct net_bridge_port *port, u16 vid);
 int nbp_vlan_init(struct net_bridge_port *port);
+int nbp_get_num_vlan_infos(struct net_bridge_port *p, u32 filter_mask);
 
-static inline struct net_port_vlans *br_get_vlan_info(
-						const struct net_bridge *br)
+static inline struct net_bridge_vlan_group *br_vlan_group(
+					const struct net_bridge *br)
 {
-	return rcu_dereference_rtnl(br->vlan_info);
+	return br->vlgrp;
 }
 
-static inline struct net_port_vlans *nbp_get_vlan_info(
-						const struct net_bridge_port *p)
+static inline struct net_bridge_vlan_group *nbp_vlan_group(
+					const struct net_bridge_port *p)
 {
-	return rcu_dereference_rtnl(p->vlan_info);
+	return p->vlgrp;
 }
 
 /* Since bridge now depends on 8021Q module, but the time bridge sees the
@@ -645,9 +715,9 @@ static inline int br_vlan_get_tag(const struct sk_buff *skb, u16 *vid)
 {
 	int err = 0;
 
-	if (skb_vlan_tag_present(skb))
+	if (skb_vlan_tag_present(skb)) {
 		*vid = skb_vlan_tag_get(skb) & VLAN_VID_MASK;
-	else {
+	} else {
 		*vid = 0;
 		err = -EINVAL;
 	}
@@ -655,13 +725,22 @@ static inline int br_vlan_get_tag(const struct sk_buff *skb, u16 *vid)
 	return err;
 }
 
-static inline u16 br_get_pvid(const struct net_port_vlans *v)
+static inline u16 br_get_pvid(const struct net_bridge *br)
 {
-	if (!v)
+	if (!br)
 		return 0;
 
 	smp_rmb();
-	return v->pvid;
+	return br->pvid;
+}
+
+static inline u16 nbp_get_pvid(const struct net_bridge_port *p)
+{
+	if (!p)
+		return 0;
+
+	smp_rmb();
+	return p->pvid;
 }
 
 static inline int br_vlan_enabled(struct net_bridge *br)
@@ -670,15 +749,20 @@ static inline int br_vlan_enabled(struct net_bridge *br)
 }
 #else
 static inline bool br_allowed_ingress(struct net_bridge *br,
-				      struct net_port_vlans *v,
 				      struct sk_buff *skb,
 				      u16 *vid)
 {
 	return true;
 }
 
-static inline bool br_allowed_egress(struct net_bridge *br,
-				     const struct net_port_vlans *v,
+static inline bool nbp_allowed_ingress(struct net_bridge_port *p,
+				       struct sk_buff *skb,
+				       u16 *vid)
+{
+	return true;
+}
+
+static inline bool br_allowed_egress(struct net_bridge_vlan_group *vg,
 				     const struct sk_buff *skb)
 {
 	return true;
@@ -691,7 +775,7 @@ static inline bool br_should_learn(struct net_bridge_port *p,
 }
 
 static inline struct sk_buff *br_handle_vlan(struct net_bridge *br,
-					     const struct net_port_vlans *v,
+					     struct net_bridge_vlan_group *vg,
 					     struct sk_buff *skb)
 {
 	return skb;
@@ -711,11 +795,6 @@ static inline void br_vlan_flush(struct net_bridge *br)
 {
 }
 
-static inline bool br_vlan_find(struct net_bridge *br, u16 vid)
-{
-	return false;
-}
-
 static inline void br_recalculate_fwd_mask(struct net_bridge *br)
 {
 }
@@ -739,32 +818,28 @@ static inline void nbp_vlan_flush(struct net_bridge_port *port)
 {
 }
 
-static inline struct net_port_vlans *br_get_vlan_info(
-						const struct net_bridge *br)
-{
-	return NULL;
-}
-static inline struct net_port_vlans *nbp_get_vlan_info(
-						const struct net_bridge_port *p)
+static inline struct net_bridge_vlan *br_vlan_find(struct net_bridge_vlan_group *vg,
+						   u16 vid)
 {
 	return NULL;
 }
 
-static inline bool nbp_vlan_find(struct net_bridge_port *port, u16 vid)
+static inline int nbp_vlan_init(struct net_bridge_port *port)
 {
-	return false;
+	return 0;
 }
 
-static inline int nbp_vlan_init(struct net_bridge_port *port)
+static inline u16 br_vlan_get_tag(const struct sk_buff *skb, u16 *tag)
 {
 	return 0;
 }
 
-static inline u16 br_vlan_get_tag(const struct sk_buff *skb, u16 *tag)
+static inline u16 br_get_pvid(const struct net_bridge *br)
 {
 	return 0;
 }
-static inline u16 br_get_pvid(const struct net_port_vlans *v)
+
+static inline u16 nbp_get_pvid(const struct net_bridge_port *p)
 {
 	return 0;
 }
@@ -779,6 +854,24 @@ static inline int __br_vlan_filter_toggle(struct net_bridge *br,
 {
 	return -EOPNOTSUPP;
 }
+
+static inline int nbp_get_num_vlan_infos(struct net_bridge_port *p,
+					 u32 filter_mask)
+{
+	return 0;
+}
+
+static inline struct net_bridge_vlan_group *br_vlan_group(
+					const struct net_bridge *br)
+{
+	return NULL;
+}
+
+static inline struct net_bridge_vlan_group *nbp_vlan_group(
+					const struct net_bridge_port *p)
+{
+	return NULL;
+}
 #endif
 
 struct nf_br_ops {