[PATCH 01/11] bridge: Add vlan filtering infrastructure
From: Vlad Yasevich <hidden>
Date: 2012-12-12 20:01:27
Subsystem:
ethernet bridge, networking [general], the rest · Maintainers:
Nikolay Aleksandrov, Ido Schimmel, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
This is an infrastructure patch. It adds 2 structures types:
net_bridge_vlan - list element of all vlans that have been configured
on the bridge.
net_port_vlan - list element of all vlans configured on a specific port.
references net_bridge_vlan.
In this implementation, bridge has a hash list of all vlans that have
been added to the bridge. Each vlan element holds a vid and port_bitmap
where each port sets its bit if a given vlan is added to the port.
Each port has its own list of vlans. Each element here refrences a vlan
from the bridge list.
Write access to both lists is protected by RTNL, and read access is
protected by RCU.
Signed-off-by: Vlad Yasevich <redacted>
---
net/bridge/br_device.c | 3 +
net/bridge/br_if.c | 203 +++++++++++++++++++++++++++++++++++++++++++++++
net/bridge/br_private.h | 30 +++++++
3 files changed, 236 insertions(+), 0 deletions(-)
diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index 7c78e26..9546742 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c@@ -332,6 +332,7 @@ static struct device_type br_type = { void br_dev_setup(struct net_device *dev) { struct net_bridge *br = netdev_priv(dev); + int i; eth_hw_addr_random(dev); ether_setup(dev);
@@ -354,6 +355,8 @@ void br_dev_setup(struct net_device *dev) spin_lock_init(&br->lock); INIT_LIST_HEAD(&br->port_list); spin_lock_init(&br->hash_lock); + for (i = 0; i < BR_VID_HASH_SIZE; i++) + INIT_HLIST_HEAD(&br->vlan_hlist[i]); br->bridge_id.prio[0] = 0x80; br->bridge_id.prio[1] = 0x00;
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 1c8fdc3..30c778e 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c@@ -83,6 +83,207 @@ void br_port_carrier_check(struct net_bridge_port *p) spin_unlock_bh(&br->lock); } + +struct net_bridge_vlan* br_vlan_find(struct net_bridge *br, u16 vid) +{ + struct net_bridge_vlan *vlan; + struct hlist_node *node; + + hlist_for_each_entry_rcu(vlan, node, + &br->vlan_hlist[br_vlan_hash(vid)], hlist) { + if (vlan->vid == vid) + return vlan; + } + + return NULL; +} + +/* Must be protected by RTNL */ +static struct net_bridge_vlan* br_vlan_add(struct net_bridge *br, u16 vid) +{ + struct net_bridge_vlan *vlan; + + ASSERT_RTNL(); + + vlan = br_vlan_find(br, vid); + if (vlan) + return vlan; + + vlan = kzalloc(sizeof(struct net_bridge_vlan), GFP_KERNEL); + if (!vlan) + return NULL; + + vlan->vid = vid; + atomic_set(&vlan->refcnt, 1); + + hlist_add_head_rcu(&vlan->hlist, &br->vlan_hlist[br_vlan_hash(vid)]); + return vlan; +} + +static void br_vlan_destroy(struct net_bridge_vlan *vlan) +{ + if (!bitmap_empty(vlan->port_bitmap, PORT_BITMAP_LEN)) { + pr_err("Attempt to delete a VLAN %d from the bridge with " + "non-empty port bitmap (%p)\n", vlan->vid, vlan); + BUG(); + } + + hlist_del_rcu(&vlan->hlist); + synchronize_net(); + kfree_rcu(vlan, rcu); +} + +static void br_vlan_hold(struct net_bridge_vlan *vlan) +{ + atomic_inc(&vlan->refcnt); +} + +static void br_vlan_put(struct net_bridge_vlan *vlan) +{ + if (atomic_dec_and_test(&vlan->refcnt)) + br_vlan_destroy(vlan); +} + +/* Must be protected by RTNL */ +static void br_vlan_del(struct net_bridge_vlan *vlan) +{ + ASSERT_RTNL(); + + /* Try to remove the vlan, but only once all the ports have + * been removed from the port bitmap + */ + if (!bitmap_empty(vlan->port_bitmap, PORT_BITMAP_LEN)) + return; + + vlan->vid = BR_INVALID_VID; + + /* Drop the self-ref to trigger descrution. */ + br_vlan_put(vlan); +} + +/* Must be protected by RTNL */ +int nbp_vlan_add(struct net_bridge_port *p, u16 vid) +{ + struct net_port_vlan *pve; + struct net_bridge_vlan *vlan; + struct net_device *dev = p->dev; + int err; + + ASSERT_RTNL(); + + /* Find a vlan in the bridge vlan list. If it isn't there, + * create it + */ + vlan = br_vlan_add(p->br, vid); + if (!vlan) + return -ENOMEM; + + /* Check to see if this port is already part of the vlan. If + * it is, there is nothing more to do. + */ + if (test_bit(p->port_no, vlan->port_bitmap)) + return -EEXIST; + + /* Create port vlan, link it to bridge vlan list, and add port the + * portgroup. + */ + pve = kmalloc(sizeof(*pve), GFP_KERNEL); + if (!pve) { + err = -ENOMEM; + goto clean_up; + } + + /* Add VLAN to the device filter if it is supported. + * Stricly speaking, this is not necessary now, since devices + * are made promiscuous by the bridge, but if that ever changes + * this code will allow tagged traffic to enter the bridge. + */ + if ((dev->features & NETIF_F_HW_VLAN_FILTER) && + dev->netdev_ops->ndo_vlan_rx_add_vid && + dev->netdev_ops->ndo_vlan_rx_kill_vid) { + err = dev->netdev_ops->ndo_vlan_rx_add_vid(dev, vid); + if (err) + goto clean_up; + } + + pve->vid = vid; + pve->vlan = vlan; + br_vlan_hold(vlan); + set_bit(p->port_no, vlan->port_bitmap); + + list_add_tail_rcu(&pve->list, &p->vlan_list); + return 0; + +clean_up: + kfree(pve); + br_vlan_del(vlan); + return err; +} + +struct net_port_vlan *nbp_vlan_find(const struct net_bridge_port *p, u16 vid) +{ + struct net_port_vlan *pve; + + /* Must be done either in rcu critical section or with RTNL held */ + WARN_ON_ONCE(!rcu_read_lock_held() && !rtnl_is_locked()); + + list_for_each_entry_rcu(pve, &p->vlan_list, list) { + if (pve->vid == vid) + return pve; + } + + return NULL; +} + +/* Must be protected by RTNL */ +int nbp_vlan_delete(struct net_bridge_port *p, u16 vid) +{ + struct net_device *dev = p->dev; + struct net_port_vlan *pve; + struct net_bridge_vlan *vlan; + + ASSERT_RTNL(); + + pve = nbp_vlan_find(p, vid); + if (!pve) + return -ENOENT; + + /* Remove VLAN from the device filter if it is supported. */ + if ((dev->features & NETIF_F_HW_VLAN_FILTER) && + dev->netdev_ops->ndo_vlan_rx_kill_vid) { + int err; + + err = dev->netdev_ops->ndo_vlan_rx_kill_vid(dev, vid); + if (err) + pr_warn("failed to kill vid %d for device %s\n", + vid, dev->name); + } + pve->vid = BR_INVALID_VID; + + vlan = pve->vlan; + pve->vlan = NULL; + clear_bit(p->port_no, vlan->port_bitmap); + br_vlan_put(vlan); + + list_del_rcu(&pve->list); + kfree_rcu(pve, rcu); + + br_vlan_del(vlan); + + return 0; +} + +static void nbp_vlan_flush(struct net_bridge_port *p) +{ + struct net_port_vlan *pve; + struct net_port_vlan *tmp; + + ASSERT_RTNL(); + + list_for_each_entry_safe(pve, tmp, &p->vlan_list, list) + nbp_vlan_delete(p, pve->vid); +} + static void release_nbp(struct kobject *kobj) { struct net_bridge_port *p
@@ -139,6 +340,7 @@ static void del_nbp(struct net_bridge_port *p) br_ifinfo_notify(RTM_DELLINK, p); + nbp_vlan_flush(p); br_fdb_delete_by_port(br, p, 1); list_del_rcu(&p->list);
@@ -222,6 +424,7 @@ static struct net_bridge_port *new_nbp(struct net_bridge *br, p->flags = 0; br_init_port(p); p->state = BR_STATE_DISABLED; + INIT_LIST_HEAD(&p->vlan_list); br_stp_port_timer_init(p); br_multicast_add_port(p);
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index ae0a6ec..1d9e6ce 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h@@ -18,6 +18,7 @@ #include <linux/netpoll.h> #include <linux/u64_stats_sync.h> #include <net/route.h> +#include <linux/if_vlan.h> #define BR_HASH_BITS 8 #define BR_HASH_SIZE (1 << BR_HASH_BITS)
@@ -26,6 +27,7 @@ #define BR_PORT_BITS 10 #define BR_MAX_PORTS (1<<BR_PORT_BITS) +#define PORT_BITMAP_LEN BITS_TO_LONGS(BR_MAX_PORTS) #define BR_VERSION "2.3"
@@ -63,6 +65,27 @@ struct br_ip __be16 proto; }; +#define BR_INVALID_VID (1<<15) +#define BR_UNTAGGED_VID (1<<14) + +#define BR_VID_HASH_SIZE (1<<6) +#define br_vlan_hash(vid) ((vid) % (BR_VID_HASH_SIZE - 1)) + +struct net_bridge_vlan { + struct hlist_node hlist; + atomic_t refcnt; + struct rcu_head rcu; + u16 vid; + unsigned long port_bitmap[PORT_BITMAP_LEN]; +}; + +struct net_port_vlan { + struct list_head list; + struct net_bridge_vlan *vlan; + struct rcu_head rcu; + u16 vid; +}; + struct net_bridge_fdb_entry { struct hlist_node hlist;
@@ -155,6 +178,7 @@ struct net_bridge_port #ifdef CONFIG_NET_POLL_CONTROLLER struct netpoll *np; #endif + struct list_head vlan_list; }; #define br_port_exists(dev) (dev->priv_flags & IFF_BRIDGE_PORT)
@@ -259,6 +283,7 @@ struct net_bridge struct timer_list topology_change_timer; struct timer_list gc_timer; struct kobject *ifobj; + struct hlist_head vlan_hlist[BR_VID_HASH_SIZE]; }; struct br_input_skb_cb {
@@ -400,6 +425,11 @@ extern int br_del_if(struct net_bridge *br, extern int br_min_mtu(const struct net_bridge *br); extern netdev_features_t br_features_recompute(struct net_bridge *br, netdev_features_t features); +extern struct net_bridge_vlan* br_vlan_find(struct net_bridge *br, u16 vid); +extern int nbp_vlan_add(struct net_bridge_port *p, u16 vid); +extern int nbp_vlan_delete(struct net_bridge_port *p, u16 vid); +extern struct net_port_vlan* nbp_vlan_find(const struct net_bridge_port *p, + u16 vid); /* br_input.c */ extern int br_handle_frame_finish(struct sk_buff *skb);
--
1.7.7.6