linux/net/bridge/br_vlan.c
Toshiaki Makita 204177f3f3 bridge: Support 802.1ad vlan filtering
This enables us to change the vlan protocol for vlan filtering.
We come to be able to filter frames on the basis of 802.1ad vlan tags
through a bridge.

This also changes br->group_addr if it has not been set by user.
This is needed for an 802.1ad bridge.
(See IEEE 802.1Q-2011 8.13.5.)

Furthermore, this sets br->group_fwd_mask_required so that an 802.1ad
bridge can forward the Nearest Customer Bridge group addresses except
for br->group_addr, which should be passed to higher layer.

To change the vlan protocol, write a protocol in sysfs:
# echo 0x88a8 > /sys/class/net/br0/bridge/vlan_protocol

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-11 15:22:53 -07:00

588 lines
12 KiB
C

#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, br->vlan_proto, 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, br->vlan_proto, 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) {
struct net_bridge_port *p = v->parent.port;
vlan_vid_del(p->dev, p->br->vlan_proto, 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)
{
bool tagged;
__be16 proto;
/* 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;
proto = br->vlan_proto;
/* 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 == proto)) {
skb = vlan_untag(skb);
if (unlikely(!skb))
return false;
}
if (!br_vlan_get_tag(skb, vid)) {
/* Tagged frame */
if (skb->vlan_proto != proto) {
/* Protocol-mismatch, empty out vlan_tci for new tag */
skb_push(skb, ETH_HLEN);
skb = __vlan_put_tag(skb, skb->vlan_proto,
vlan_tx_tag_get(skb));
if (unlikely(!skb))
return false;
skb_pull(skb, ETH_HLEN);
skb_reset_mac_len(skb);
*vid = 0;
tagged = false;
} else {
tagged = true;
}
} else {
/* Untagged frame */
tagged = false;
}
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(!tagged))
/* Untagged Frame. */
__vlan_hwaccel_put_tag(skb, proto, 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;
}
/* Called under RCU */
bool br_should_learn(struct net_bridge_port *p, struct sk_buff *skb, u16 *vid)
{
struct net_bridge *br = p->br;
struct net_port_vlans *v;
if (!br->vlan_enabled)
return true;
v = rcu_dereference(p->vlan_info);
if (!v)
return false;
if (!br_vlan_get_tag(skb, vid) && skb->vlan_proto != br->vlan_proto)
*vid = 0;
if (!*vid) {
*vid = br_get_pvid(v);
if (*vid == VLAN_N_VID)
return false;
return true;
}
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);
}
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;
}
/* Must be protected by RTNL. */
static void recalculate_group_addr(struct net_bridge *br)
{
if (br->group_addr_set)
return;
spin_lock_bh(&br->lock);
if (!br->vlan_enabled || br->vlan_proto == htons(ETH_P_8021Q)) {
/* Bridge Group Address */
br->group_addr[5] = 0x00;
} else { /* vlan_enabled && ETH_P_8021AD */
/* Provider Bridge Group Address */
br->group_addr[5] = 0x08;
}
spin_unlock_bh(&br->lock);
}
/* Must be protected by RTNL. */
void br_recalculate_fwd_mask(struct net_bridge *br)
{
if (!br->vlan_enabled || br->vlan_proto == htons(ETH_P_8021Q))
br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
else /* vlan_enabled && ETH_P_8021AD */
br->group_fwd_mask_required = BR_GROUPFWD_8021AD &
~(1u << br->group_addr[5]);
}
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;
br_manage_promisc(br);
recalculate_group_addr(br);
br_recalculate_fwd_mask(br);
unlock:
rtnl_unlock();
return 0;
}
int br_vlan_set_proto(struct net_bridge *br, unsigned long val)
{
int err = 0;
struct net_bridge_port *p;
struct net_port_vlans *pv;
__be16 proto, oldproto;
u16 vid, errvid;
if (val != ETH_P_8021Q && val != ETH_P_8021AD)
return -EPROTONOSUPPORT;
if (!rtnl_trylock())
return restart_syscall();
proto = htons(val);
if (br->vlan_proto == proto)
goto unlock;
/* Add VLANs for the new proto to the device filter. */
list_for_each_entry(p, &br->port_list, list) {
pv = rtnl_dereference(p->vlan_info);
if (!pv)
continue;
for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
err = vlan_vid_add(p->dev, proto, vid);
if (err)
goto err_filt;
}
}
oldproto = br->vlan_proto;
br->vlan_proto = proto;
recalculate_group_addr(br);
br_recalculate_fwd_mask(br);
/* Delete VLANs for the old proto from the device filter. */
list_for_each_entry(p, &br->port_list, list) {
pv = rtnl_dereference(p->vlan_info);
if (!pv)
continue;
for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
vlan_vid_del(p->dev, oldproto, vid);
}
unlock:
rtnl_unlock();
return err;
err_filt:
errvid = vid;
for_each_set_bit(vid, pv->vlan_bitmap, errvid)
vlan_vid_del(p->dev, proto, vid);
list_for_each_entry_continue_reverse(p, &br->port_list, list) {
pv = rtnl_dereference(p->vlan_info);
if (!pv)
continue;
for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
vlan_vid_del(p->dev, proto, vid);
}
goto unlock;
}
void br_vlan_init(struct net_bridge *br)
{
br->vlan_proto = htons(ETH_P_8021Q);
}
/* 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, port->br->vlan_proto, 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;
}