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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2009-10-26 18:40:35 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-10-27 01:02:33 -0700 |
| commit | 05423b241311c9380b7280179295bac7794281b6 (patch) | |
| tree | 8a84aca48cbc30b142bdf143dbf11fdbab9cad67 /net/8021q/vlan.h | |
| parent | 9dbb58d867e90d2528752339751216c955523e62 (diff) | |
| download | linux-stable-05423b241311c9380b7280179295bac7794281b6.tar.gz linux-stable-05423b241311c9380b7280179295bac7794281b6.tar.bz2 linux-stable-05423b241311c9380b7280179295bac7794281b6.zip | |
vlan: allow null VLAN ID to be used
We currently use a 16 bit field (vlan_tci) to store VLAN ID/PRIO on a skb.
Null value is used as a special value, meaning vlan tagging not enabled.
This forbids use of null vlan ID.
As pointed by David, some drivers use the 3 high order bits (PRIO)
As VLAN ID is 12 bits, we can use the remaining bit (CFI) as a flag, and
allow null VLAN ID.
In case future code really wants to use VLAN_CFI_MASK, we'll have to use
a bit outside of vlan_tci.
#define VLAN_PRIO_MASK 0xe000 /* Priority Code Point */
#define VLAN_PRIO_SHIFT 13
#define VLAN_CFI_MASK 0x1000 /* Canonical Format Indicator */
#define VLAN_TAG_PRESENT VLAN_CFI_MASK
#define VLAN_VID_MASK 0x0fff /* VLAN Identifier */
Reported-by: Gertjan Hofman <gertjan_hofman@yahoo.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/8021q/vlan.h')
| -rw-r--r-- | net/8021q/vlan.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/8021q/vlan.h b/net/8021q/vlan.h index 82570bc2a180..4ade5edf1033 100644 --- a/net/8021q/vlan.h +++ b/net/8021q/vlan.h @@ -89,7 +89,7 @@ static inline u32 vlan_get_ingress_priority(struct net_device *dev, { struct vlan_dev_info *vip = vlan_dev_info(dev); - return vip->ingress_priority_map[(vlan_tci >> 13) & 0x7]; + return vip->ingress_priority_map[(vlan_tci >> VLAN_PRIO_SHIFT) & 0x7]; } #ifdef CONFIG_VLAN_8021Q_GVRP |