Commit 0a85df00 authored by Hao Zheng's avatar Hao Zheng Committed by David S. Miller

vlan: Add function to retrieve EtherType from vlan packets.

Depending on how a packet is vlan tagged (i.e. hardware accelerated or
not), the encapsulated protocol is stored in different locations.  This
provides a consistent method of accessing that protocol, which is needed
by drivers, security checks, etc.
Signed-off-by: default avatarHao Zheng <hzheng@nicira.com>
Signed-off-by: default avatarJesse Gross <jesse@nicira.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 167c25e4
......@@ -339,6 +339,31 @@ static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
}
}
/**
* vlan_get_protocol - get protocol EtherType.
* @skb: skbuff to query
*
* Returns the EtherType of the packet, regardless of whether it is
* vlan encapsulated (normal or hardware accelerated) or not.
*/
static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
{
__be16 protocol = 0;
if (vlan_tx_tag_present(skb) ||
skb->protocol != cpu_to_be16(ETH_P_8021Q))
protocol = skb->protocol;
else {
__be16 proto, *protop;
protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
h_vlan_encapsulated_proto),
sizeof(proto), &proto);
if (likely(protop))
protocol = *protop;
}
return protocol;
}
#endif /* __KERNEL__ */
/* VLAN IOCTLs are found in sockios.h */
......
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