Re: [PATCH net] bonding: enhance L2 hash helper with packet type

[Jianhua Xie <jianhua.xie@freescale.com>]

On 7/14/2014 5:15 PM, Eric Dumazet wrote:
> On Mon, 2014-07-14 at 14:05 +0800, Xie Jianhua wrote:
>> From: Jianhua Xie <jianhua.xie@freescale.com>
>>
>> Current L2 hash helper calculates destination eth addr and
>> source ether addr as L2 hash factors. This patch is adding
>> packet type ID field into hash factors, which can help to
>> distribute different types of packets like IPv4/IPv6 packets
>> to different slave devices while only BOND_XMIT_POLICY_LAYER2
>> is applied.
>>
>> CC: Jay Vosburgh <j.vosburgh@gmail.com>
>> CC: Veaceslav Falico <vfalico@gmail.com>
>> CC: Andy Gospodarek <andy@greyhouse.net>
>> CC: David S. Miller <davem@davemloft.net>
>> CC: Pan Jiafei <Jiafei.Pan@freescale.com>
>>
>> Signed-off-by: Jianhua Xie <jianhua.xie@freescale.com>
>> ---
>>   drivers/net/bonding/bond_main.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>> index 3a451b6..4a72c2f 100644
>> --- a/drivers/net/bonding/bond_main.c
>> +++ b/drivers/net/bonding/bond_main.c
>> @@ -3002,7 +3002,7 @@ static inline u32 bond_eth_hash(struct sk_buff *skb)
>>   	struct ethhdr *data = (struct ethhdr *)skb->data;
>>   
>>   	if (skb_headlen(skb) >= offsetof(struct ethhdr, h_proto))
>> -		return data->h_dest[5] ^ data->h_source[5];
>> +		return data->h_dest[5] ^ data->h_source[5] ^ data->h_proto;
>>   
>>   	return 0;
>>   }
> If you really want this, you also need to change the test, because
> otherwise there is no guarantee data->h_proto is valid at his point.
>
> if (skb_headlen(skb) >= sizeof(*data))
>     ..
Thanks for so helpful comments, I see now.  May I use ETH_HLEN to 
instead of sizeof(*data)?

Regards,
Jianhua