In previous kernels, any kernel module could get access to the
'real-device' and the VLAN-ID for a particular VLAN.  In more recent
kernels, the code was restructured such that this is hard to do
without accessing private .h files for any module that cannot use
GPL-only symbols.

Attached is a patch to once again allow non-GPL modules the ability to
access the real-device and VLAN id for VLANs.
Signed-off-by: NBen Greear <greearb@candelatech.com>
Acked-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds GRO interfaces for hardware-assisted VLAN reception.
With this in place we're now at parity with LRO as far as the
interface is concerned.  That is, you can now take any LRO driver
and convert it over to GRO.

As the CB memory clashes with GRO's use of CB, I've removed it
entirely by storing dev in skb->dev.  This is OK because VLAN
gets called first thing in netif_receive_skb and skb->dev is
not used in between us calling netif_rx and netif_receive_skb
getting called.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The changes to deliver hardware accelerated VLAN packets to packet
sockets (commit bc1d0411) caused a warning for non-NAPI drivers.
The __vlan_hwaccel_rx() function is called directly from the drivers
RX function, for non-NAPI drivers that means its still in RX IRQ
context:

[   27.779463] ------------[ cut here ]------------
[   27.779509] WARNING: at kernel/softirq.c:136 local_bh_enable+0x37/0x81()
...
[   27.782520]  [<c0264755>] netif_nit_deliver+0x5b/0x75
[   27.782590]  [<c02bba83>] __vlan_hwaccel_rx+0x79/0x162
[   27.782664]  [<f8851c1d>] atl1_intr+0x9a9/0xa7c [atl1]
[   27.782738]  [<c0155b17>] handle_IRQ_event+0x23/0x51
[   27.782808]  [<c015692e>] handle_edge_irq+0xc2/0x102
[   27.782878]  [<c0105fd5>] do_IRQ+0x4d/0x64

Split hardware accelerated VLAN reception into two parts to fix this:

- __vlan_hwaccel_rx just stores the VLAN TCI and performs the VLAN
  device lookup, then calls netif_receive_skb()/netif_rx()

- vlan_hwaccel_do_receive(), which is invoked by netif_receive_skb()
  in softirq context, performs the real reception and delivery to
  packet sockets.
Reported-and-tested-by: NRamon Casellas <ramon.casellas@cttc.es>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The generic packet receive code takes care of setting
netdev->last_rx when necessary, for the sake of the
bonding ARP monitor.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When VLAN header stripping is used, packets currently bypass packet
sockets (and other network taps) completely. For locally existing
VLANs, they appear directly on the VLAN device, for unknown VLANs
they are silently dropped.

Add a new function netif_nit_deliver() to deliver incoming packets
to all network interface taps and use it in __vlan_hwaccel_rx() to
make VLAN packets visible on the underlying device.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The VLAN code contains multiple spots that use tag, id and tci as
identifiers for arguments and variables incorrectly and they actually
contain or are expected to contain something different. Additionally
types are used inconsistently (unsigned short vs u16) and identifiers
are sometimes capitalized.

- consistently use u16 for storing TCI, ID or QoS values
- consistently use vlan_id and vlan_tci for storing the respective values
- remove capitalization
- add kdoc comment to netif_hwaccel_{rx,receive_skb}
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Hide struct vlan_dev_info from drivers to prevent them from growing
more creative ways to use it. Provide accessors for the two drivers
that currently use it.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The function is huge and included at least once in every VLAN acceleration
capable driver. Uninline it; to avoid having drivers depend on the VLAN
module, the function is always built in statically when VLAN is enabled.

With all VLAN acceleration capable drivers that build on x86_64 enabled,
this results in:

   text    data     bss     dec     hex filename
6515227  854044  343968 7713239  75b1d7 vmlinux.inlined
6505637  854044  343968 7703649  758c61 vmlinux.uninlined
----------------------------------------------------------
  -9590
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>