linux/include
Toke Høiland-Jørgensen d7bf2ebebc sched: consistently handle layer3 header accesses in the presence of VLANs
There are a couple of places in net/sched/ that check skb->protocol and act
on the value there. However, in the presence of VLAN tags, the value stored
in skb->protocol can be inconsistent based on whether VLAN acceleration is
enabled. The commit quoted in the Fixes tag below fixed the users of
skb->protocol to use a helper that will always see the VLAN ethertype.

However, most of the callers don't actually handle the VLAN ethertype, but
expect to find the IP header type in the protocol field. This means that
things like changing the ECN field, or parsing diffserv values, stops
working if there's a VLAN tag, or if there are multiple nested VLAN
tags (QinQ).

To fix this, change the helper to take an argument that indicates whether
the caller wants to skip the VLAN tags or not. When skipping VLAN tags, we
make sure to skip all of them, so behaviour is consistent even in QinQ
mode.

To make the helper usable from the ECN code, move it to if_vlan.h instead
of pkt_sched.h.

v3:
- Remove empty lines
- Move vlan variable definitions inside loop in skb_protocol()
- Also use skb_protocol() helper in IP{,6}_ECN_decapsulate() and
  bpf_skb_ecn_set_ce()

v2:
- Use eth_type_vlan() helper in skb_protocol()
- Also fix code that reads skb->protocol directly
- Change a couple of 'if/else if' statements to switch constructs to avoid
  calling the helper twice

Reported-by: Ilya Ponetayev <i.ponetaev@ndmsystems.com>
Fixes: d8b9605d26 ("net: sched: fix skb->protocol use in case of accelerated vlan path")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-03 14:34:53 -07:00
..
acpi Merge branch 'acpica' 2020-06-10 17:27:28 +02:00
asm-generic mm: Allow arches to provide ptep_get() 2020-06-20 22:14:53 +10:00
clocksource
crypto
drm drm/edid: Replace zero-length array with flexible-array 2020-06-15 23:08:31 -05:00
dt-bindings - qcom : 2020-06-11 12:42:14 -07:00
keys RxRPC: Replace zero-length array with flexible-array 2020-06-15 23:08:32 -05:00
kunit
kvm
linux sched: consistently handle layer3 header accesses in the presence of VLANs 2020-07-03 14:34:53 -07:00
math-emu
media media updates for v5.8-rc1 2020-06-13 13:09:38 -07:00
misc
net sched: consistently handle layer3 header accesses in the presence of VLANs 2020-07-03 14:34:53 -07:00
pcmcia
ras
rdma dynamic_debug: add an option to enable dynamic debug for modules only 2020-06-08 11:05:56 -07:00
scsi SCSI misc on 20200605 2020-06-05 15:11:50 -07:00
soc pci-v5.8-changes 2020-06-06 11:01:58 -07:00
sound ASoC: Fixes for v5.8 2020-06-22 13:49:14 +02:00
target scsi: target: Rename target_setup_cmd_from_cdb() to target_cmd_parse_cdb() 2020-06-09 21:57:26 -04:00
trace Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-25 18:27:40 -07:00
uapi Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2020-06-30 14:20:45 -07:00
vdso
video
xen xen: Move xen_setup_callback_vector() definition to include/xen/hvm.h 2020-06-11 15:15:19 +02:00