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authorVlad Yasevich <vyasevich@gmail.com>2015-11-16 15:43:44 -0500
committerSasha Levin <sasha.levin@oracle.com>2016-01-15 18:41:51 -0500
commit6ff6d3c9349681cbe2559a6f47c93a8c716ece1d (patch)
treecd7f9e1348279443dec338e3a2def9b649bb11f0
parent54b6eaa343c145b4a6aafa31025cf6d3baaac324 (diff)
downloadlwn-6ff6d3c9349681cbe2559a6f47c93a8c716ece1d.tar.gz
lwn-6ff6d3c9349681cbe2559a6f47c93a8c716ece1d.zip
vlan: Fix untag operations of stacked vlans with REORDER_HEADER off
[ Upstream commit a6e18ff111701b4ff6947605bfbe9594ec42a6e8 ] When we have multiple stacked vlan devices all of which have turned off REORDER_HEADER flag, the untag operation does not locate the ethernet addresses correctly for nested vlans. The reason is that in case of REORDER_HEADER flag being off, the outer vlan headers are put back and the mac_len is adjusted to account for the presense of the header. Then, the subsequent untag operation, for the next level vlan, always use VLAN_ETH_HLEN to locate the begining of the ethernet header and that ends up being a multiple of 4 bytes short of the actuall beginning of the mac header (the multiple depending on the how many vlan encapsulations ethere are). As a reslult, if there are multiple levles of vlan devices with REODER_HEADER being off, the recevied packets end up being dropped. To solve this, we use skb->mac_len as the offset. The value is always set on receive path and starts out as a ETH_HLEN. The value is also updated when the vlan header manupations occur so we know it will be correct. Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
-rw-r--r--net/core/skbuff.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index ea0bcc4a9657..7c7b2c00e70b 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4108,7 +4108,8 @@ static struct sk_buff *skb_reorder_vlan_header(struct sk_buff *skb)
return NULL;
}
- memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
+ memmove(skb->data - ETH_HLEN, skb->data - skb->mac_len,
+ 2 * ETH_ALEN);
skb->mac_header += VLAN_HLEN;
return skb;
}