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| author | Eric Dumazet <edumazet@google.com> | 2013-07-18 07:19:26 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-07-18 13:05:23 -0700 |
| commit | d4b812dea4a236f729526facf97df1a9d18e191c (patch) | |
| tree | 55effa330847edd70cf20502603c23e4ca8084a4 /net/core/dev.c | |
| parent | ece793fcfc417b3925844be88a6a6dc82ae8f7c6 (diff) | |
| download | lwn-d4b812dea4a236f729526facf97df1a9d18e191c.tar.gz lwn-d4b812dea4a236f729526facf97df1a9d18e191c.zip | |
vlan: mask vlan prio bits
In commit 48cc32d38a52d0b68f91a171a8d00531edc6a46e
("vlan: don't deliver frames for unknown vlans to protocols")
Florian made sure we set pkt_type to PACKET_OTHERHOST
if the vlan id is set and we could find a vlan device for this
particular id.
But we also have a problem if prio bits are set.
Steinar reported an issue on a router receiving IPv6 frames with a
vlan tag of 4000 (id 0, prio 2), and tunneled into a sit device,
because skb->vlan_tci is set.
Forwarded frame is completely corrupted : We can see (8100:4000)
being inserted in the middle of IPv6 source address :
16:48:00.780413 IP6 2001:16d8:8100:4000:ee1c:0:9d9:bc87 >
9f94:4d95:2001:67c:29f4::: ICMP6, unknown icmp6 type (0), length 64
0x0000: 0000 0029 8000 c7c3 7103 0001 a0ae e651
0x0010: 0000 0000 ccce 0b00 0000 0000 1011 1213
0x0020: 1415 1617 1819 1a1b 1c1d 1e1f 2021 2223
0x0030: 2425 2627 2829 2a2b 2c2d 2e2f 3031 3233
It seems we are not really ready to properly cope with this right now.
We can probably do better in future kernels :
vlan_get_ingress_priority() should be a netdev property instead of
a per vlan_dev one.
For stable kernels, lets clear vlan_tci to fix the bugs.
Reported-by: Steinar H. Gunderson <sesse@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index a3d8d44cb7f4..26755dd40daa 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3580,8 +3580,15 @@ ncls: } } - if (vlan_tx_nonzero_tag_present(skb)) - skb->pkt_type = PACKET_OTHERHOST; + if (unlikely(vlan_tx_tag_present(skb))) { + if (vlan_tx_tag_get_id(skb)) + skb->pkt_type = PACKET_OTHERHOST; + /* Note: we might in the future use prio bits + * and set skb->priority like in vlan_do_receive() + * For the time being, just ignore Priority Code Point + */ + skb->vlan_tci = 0; + } /* deliver only exact match when indicated */ null_or_dev = deliver_exact ? skb->dev : NULL; |