linux/include
Eric Dumazet 05423b2413 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>
2009-10-27 01:02:33 -07:00
..
acpi ACPI: remove acpi_device_uid() and related stuff 2009-09-25 15:09:49 -04:00
asm-generic net: Generalize socket rx gap / receive queue overflow cmsg 2009-10-12 13:26:31 -07:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2009-09-11 09:38:37 -07:00
drm Merge branch 'drm-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2009-09-30 08:03:00 -07:00
keys RxRPC: Use uX/sX rather than uintX_t/intX_t types 2009-09-16 00:01:13 -07:00
linux vlan: allow null VLAN ID to be used 2009-10-27 01:02:33 -07:00
math-emu
media V4L/DVB (13019): video: initial support for ADV7180 2009-09-19 00:53:39 -03:00
mtd
net rtnetlink: speedup rtnl_dump_ifinfo() 2009-10-24 06:13:17 -07:00
pcmcia PM / PCMCIA: Drop second argument of pcmcia_socket_dev_suspend() 2009-09-29 00:10:41 +02:00
rdma trivial: fix typo "to to" in multiple files 2009-09-21 15:14:55 +02:00
rxrpc
scsi trivial: remove unnecessary semicolons 2009-09-21 15:14:58 +02:00
sound Merge branch 'topic/ymfpci' into for-linus 2009-09-10 15:33:09 +02:00
trace Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block 2009-10-04 12:39:14 -07:00
video davinci-fb-frame-buffer-driver-for-ti-da8xx-omap-l1xx-v4 2009-09-23 07:39:51 -07:00
xen
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