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linux-next/net/bridge/br_vlan.c

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#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include "br_private.h"
static void __vlan_add_pvid(struct net_port_vlans *v, u16 vid)
{
if (v->pvid == vid)
return;
smp_wmb();
v->pvid = vid;
}
static void __vlan_delete_pvid(struct net_port_vlans *v, u16 vid)
{
if (v->pvid != vid)
return;
smp_wmb();
v->pvid = 0;
}
static void __vlan_add_flags(struct net_port_vlans *v, u16 vid, u16 flags)
{
if (flags & BRIDGE_VLAN_INFO_PVID)
__vlan_add_pvid(v, vid);
if (flags & BRIDGE_VLAN_INFO_UNTAGGED)
set_bit(vid, v->untagged_bitmap);
}
static int __vlan_add(struct net_port_vlans *v, u16 vid, u16 flags)
{
struct net_bridge_port *p = NULL;
struct net_bridge *br;
struct net_device *dev;
int err;
if (test_bit(vid, v->vlan_bitmap)) {
__vlan_add_flags(v, vid, flags);
return 0;
}
if (v->port_idx) {
p = v->parent.port;
br = p->br;
dev = p->dev;
} else {
br = v->parent.br;
dev = br->dev;
}
if (p) {
/* 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.
*/
err = vlan_vid_add(dev, htons(ETH_P_8021Q), vid);
if (err)
return err;
}
err = br_fdb_insert(br, p, dev->dev_addr, vid);
if (err) {
br_err(br, "failed insert local address into bridge "
"forwarding table\n");
goto out_filt;
}
set_bit(vid, v->vlan_bitmap);
v->num_vlans++;
__vlan_add_flags(v, vid, flags);
return 0;
out_filt:
if (p)
vlan_vid_del(dev, htons(ETH_P_8021Q), vid);
return err;
}
static int __vlan_del(struct net_port_vlans *v, u16 vid)
{
if (!test_bit(vid, v->vlan_bitmap))
return -EINVAL;
__vlan_delete_pvid(v, vid);
clear_bit(vid, v->untagged_bitmap);
if (v->port_idx)
vlan_vid_del(v->parent.port->dev, htons(ETH_P_8021Q), vid);
clear_bit(vid, v->vlan_bitmap);
v->num_vlans--;
if (bitmap_empty(v->vlan_bitmap, VLAN_N_VID)) {
if (v->port_idx)
RCU_INIT_POINTER(v->parent.port->vlan_info, NULL);
else
RCU_INIT_POINTER(v->parent.br->vlan_info, NULL);
kfree_rcu(v, rcu);
}
return 0;
}
static void __vlan_flush(struct net_port_vlans *v)
{
smp_wmb();
v->pvid = 0;
bitmap_zero(v->vlan_bitmap, VLAN_N_VID);
if (v->port_idx)
RCU_INIT_POINTER(v->parent.port->vlan_info, NULL);
else
RCU_INIT_POINTER(v->parent.br->vlan_info, NULL);
kfree_rcu(v, rcu);
}
struct sk_buff *br_handle_vlan(struct net_bridge *br,
const struct net_port_vlans *pv,
struct sk_buff *skb)
{
u16 vid;
if (!br->vlan_enabled)
goto out;
/* Vlan filter table must be configured at this point. The
* only exception is the bridge is set in promisc mode and the
* packet is destined for the bridge device. In this case
* pass the packet as is.
*/
if (!pv) {
if ((br->dev->flags & IFF_PROMISC) && skb->dev == br->dev) {
goto out;
} else {
kfree_skb(skb);
return NULL;
}
}
/* At this point, we know that the frame was filtered and contains
* a valid vlan id. If the vlan id is set in the untagged bitmap,
* send untagged; otherwise, send tagged.
*/
br_vlan_get_tag(skb, &vid);
if (test_bit(vid, pv->untagged_bitmap))
skb->vlan_tci = 0;
out:
return skb;
}
/* Called under RCU */
bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
struct sk_buff *skb, u16 *vid)
{
int err;
/* If VLAN filtering is disabled on the bridge, all packets are
* permitted.
*/
if (!br->vlan_enabled)
return true;
/* If there are no vlan in the permitted list, all packets are
* rejected.
*/
if (!v)
goto drop;
/* If vlan tx offload is disabled on bridge device and frame was
* sent from vlan device on the bridge device, it does not have
* HW accelerated vlan tag.
*/
if (unlikely(!vlan_tx_tag_present(skb) &&
(skb->protocol == htons(ETH_P_8021Q) ||
skb->protocol == htons(ETH_P_8021AD)))) {
skb = vlan_untag(skb);
if (unlikely(!skb))
return false;
}
err = br_vlan_get_tag(skb, vid);
if (!*vid) {
u16 pvid = br_get_pvid(v);
/* Frame had a tag with VID 0 or did not have a tag.
* See if pvid is set on this port. That tells us which
* vlan untagged or priority-tagged traffic belongs to.
*/
if (pvid == VLAN_N_VID)
goto drop;
/* PVID is set on this port. Any untagged or priority-tagged
* ingress frame is considered to belong to this vlan.
*/
*vid = pvid;
if (likely(err))
/* Untagged Frame. */
__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), pvid);
else
/* Priority-tagged Frame.
* At this point, We know that skb->vlan_tci had
* VLAN_TAG_PRESENT bit and its VID field was 0x000.
* We update only VID field and preserve PCP field.
*/
skb->vlan_tci |= pvid;
return true;
}
/* Frame had a valid vlan tag. See if vlan is allowed */
if (test_bit(*vid, v->vlan_bitmap))
return true;
drop:
kfree_skb(skb);
return false;
}
/* Called under RCU. */
bool br_allowed_egress(struct net_bridge *br,
const struct net_port_vlans *v,
const struct sk_buff *skb)
{
u16 vid;
if (!br->vlan_enabled)
return true;
if (!v)
return false;
br_vlan_get_tag(skb, &vid);
if (test_bit(vid, v->vlan_bitmap))
return true;
return false;
}
/* Must be protected by RTNL.
* Must be called with vid in range from 1 to 4094 inclusive.
*/
int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
{
struct net_port_vlans *pv = NULL;
int err;
ASSERT_RTNL();
pv = rtnl_dereference(br->vlan_info);
if (pv)
return __vlan_add(pv, vid, flags);
/* Create port vlan infomration
*/
pv = kzalloc(sizeof(*pv), GFP_KERNEL);
if (!pv)
return -ENOMEM;
pv->parent.br = br;
err = __vlan_add(pv, vid, flags);
if (err)
goto out;
rcu_assign_pointer(br->vlan_info, pv);
return 0;
out:
kfree(pv);
return err;
}
/* Must be protected by RTNL.
* Must be called with vid in range from 1 to 4094 inclusive.
*/
int br_vlan_delete(struct net_bridge *br, u16 vid)
{
struct net_port_vlans *pv;
ASSERT_RTNL();
pv = rtnl_dereference(br->vlan_info);
if (!pv)
return -EINVAL;
br_fdb_find_delete_local(br, NULL, br->dev->dev_addr, vid);
__vlan_del(pv, vid);
return 0;
}
void br_vlan_flush(struct net_bridge *br)
{
struct net_port_vlans *pv;
ASSERT_RTNL();
pv = rtnl_dereference(br->vlan_info);
if (!pv)
return;
__vlan_flush(pv);
}
bridge: Fix the way to check if a local fdb entry can be deleted We should take into account the followings when deleting a local fdb entry. - nbp_vlan_find() can be used only when vid != 0 to check if an entry is deletable, because a fdb entry with vid 0 can exist at any time while nbp_vlan_find() always return false with vid 0. Example of problematic case: ip link set eth0 address 12:34:56:78:90:ab ip link set eth1 address 12:34:56:78:90:ab brctl addif br0 eth0 brctl addif br0 eth1 ip link set eth0 address aa:bb:cc:dd:ee:ff Then, the fdb entry 12:34:56:78:90:ab will be deleted even though the bridge port eth1 still has that address. - The port to which the bridge device is attached might needs a local entry if its mac address is set manually. Example of problematic case: ip link set eth0 address 12:34:56:78:90:ab brctl addif br0 eth0 ip link set br0 address 12:34:56:78:90:ab ip link set eth0 address aa:bb:cc:dd:ee:ff Then, the fdb still must have the entry 12:34:56:78:90:ab, but it will be deleted. We can use br->dev->addr_assign_type to check if the address is manually set or not, but I propose another approach. Since we delete and insert local entries whenever changing mac address of the bridge device, we can change dst of the entry to NULL regardless of addr_assign_type when deleting an entry associated with a certain port, and if it is found to be unnecessary later, then delete it. That is, if changing mac address of a port, the entry might be changed to its dst being NULL first, but is eventually deleted when recalculating and changing bridge id. This approach is especially useful when we want to share the code with deleting vlan in which the bridge device might want such an entry regardless of addr_assign_type, and makes things easy because we don't have to consider if mac address of the bridge device will be changed or not at the time we delete a local entry of a port, which means fdb code will not be bothered even if the bridge id calculating logic is changed in the future. Also, this change reduces inconsistent state, where frames whose dst is the mac address of the bridge, can't reach the bridge because of premature fdb entry deletion. This change reduces the possibility that the bridge device replies unreachable mac address to arp requests, which could occur during the short window between calling del_nbp() and br_stp_recalculate_bridge_id() in br_del_if(). This will effective after br_fdb_delete_by_port() starts to use the same code by following patch. Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Acked-by: Vlad Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-07 15:48:22 +08:00
bool br_vlan_find(struct net_bridge *br, u16 vid)
{
struct net_port_vlans *pv;
bool found = false;
rcu_read_lock();
pv = rcu_dereference(br->vlan_info);
if (!pv)
goto out;
if (test_bit(vid, pv->vlan_bitmap))
found = true;
out:
rcu_read_unlock();
return found;
}
int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val)
{
if (!rtnl_trylock())
return restart_syscall();
if (br->vlan_enabled == val)
goto unlock;
br->vlan_enabled = val;
unlock:
rtnl_unlock();
return 0;
}
/* Must be protected by RTNL.
* Must be called with vid in range from 1 to 4094 inclusive.
*/
int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags)
{
struct net_port_vlans *pv = NULL;
int err;
ASSERT_RTNL();
pv = rtnl_dereference(port->vlan_info);
if (pv)
return __vlan_add(pv, vid, flags);
/* Create port vlan infomration
*/
pv = kzalloc(sizeof(*pv), GFP_KERNEL);
if (!pv) {
err = -ENOMEM;
goto clean_up;
}
pv->port_idx = port->port_no;
pv->parent.port = port;
err = __vlan_add(pv, vid, flags);
if (err)
goto clean_up;
rcu_assign_pointer(port->vlan_info, pv);
return 0;
clean_up:
kfree(pv);
return err;
}
/* Must be protected by RTNL.
* Must be called with vid in range from 1 to 4094 inclusive.
*/
int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
{
struct net_port_vlans *pv;
ASSERT_RTNL();
pv = rtnl_dereference(port->vlan_info);
if (!pv)
return -EINVAL;
br_fdb_find_delete_local(port->br, port, port->dev->dev_addr, vid);
return __vlan_del(pv, vid);
}
void nbp_vlan_flush(struct net_bridge_port *port)
{
struct net_port_vlans *pv;
u16 vid;
ASSERT_RTNL();
pv = rtnl_dereference(port->vlan_info);
if (!pv)
return;
for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
vlan_vid_del(port->dev, htons(ETH_P_8021Q), vid);
__vlan_flush(pv);
}
bool nbp_vlan_find(struct net_bridge_port *port, u16 vid)
{
struct net_port_vlans *pv;
bool found = false;
rcu_read_lock();
pv = rcu_dereference(port->vlan_info);
if (!pv)
goto out;
if (test_bit(vid, pv->vlan_bitmap))
found = true;
out:
rcu_read_unlock();
return found;
}