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| author | Eric Dumazet <[email protected]> | 2009-10-27 01:40:35 +0000 |
|---|---|---|
| committer | David S. Miller <[email protected]> | 2009-10-27 08:02:33 +0000 |
| commit | 05423b241311c9380b7280179295bac7794281b6 (patch) | |
| tree | 8a84aca48cbc30b142bdf143dbf11fdbab9cad67 /net/unix/af_unix.c | |
| parent | can: sja1000: fix bug using library functions for skb allocation (diff) | |
| download | kernel-05423b241311c9380b7280179295bac7794281b6.tar.gz kernel-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 <[email protected]>
Signed-off-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Diffstat (limited to 'net/unix/af_unix.c')
0 files changed, 0 insertions, 0 deletions