Commit da8c8724 authored by Cong Wang's avatar Cong Wang Committed by David S. Miller

vlan: adjust vlan_set_encap_proto() for its callers

There are two places to call vlan_set_encap_proto():
vlan_untag() and __pop_vlan_tci().

vlan_untag() assumes skb->data points after mac addr, otherwise
the following code

        vhdr = (struct vlan_hdr *) skb->data;
        vlan_tci = ntohs(vhdr->h_vlan_TCI);
        __vlan_hwaccel_put_tag(skb, vlan_tci);

        skb_pull_rcsum(skb, VLAN_HLEN);

won't be correct. But __pop_vlan_tci() assumes points _before_
mac addr.

In vlan_set_encap_proto(), it looks for some magic L2 value
after mac addr:

        rawp = skb->data;
        if (*(unsigned short *) rawp == 0xFFFF)
	...

Therefore __pop_vlan_tci() is obviously wrong.

A quick fix is avoiding using skb->data in vlan_set_encap_proto(),
use 'vhdr+1' is always correct in both cases.

Cc: David S. Miller <davem@davemloft.net>
Cc: Jesse Gross <jesse@nicira.com>
Signed-off-by: default avatarCong Wang <amwang@redhat.com>
Acked-by: default avatarJesse Gross <jesse@nicira.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8e904550
...@@ -331,7 +331,7 @@ static inline void vlan_set_encap_proto(struct sk_buff *skb, ...@@ -331,7 +331,7 @@ static inline void vlan_set_encap_proto(struct sk_buff *skb,
struct vlan_hdr *vhdr) struct vlan_hdr *vhdr)
{ {
__be16 proto; __be16 proto;
unsigned char *rawp; unsigned short *rawp;
/* /*
* Was a VLAN packet, grab the encapsulated protocol, which the layer * Was a VLAN packet, grab the encapsulated protocol, which the layer
...@@ -344,8 +344,8 @@ static inline void vlan_set_encap_proto(struct sk_buff *skb, ...@@ -344,8 +344,8 @@ static inline void vlan_set_encap_proto(struct sk_buff *skb,
return; return;
} }
rawp = skb->data; rawp = (unsigned short *)(vhdr + 1);
if (*(unsigned short *) rawp == 0xFFFF) if (*rawp == 0xFFFF)
/* /*
* This is a magic hack to spot IPX packets. Older Novell * This is a magic hack to spot IPX packets. Older Novell
* breaks the protocol design and runs IPX over 802.3 without * breaks the protocol design and runs IPX over 802.3 without
......
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