RE: [PATCH net-next] hyperv: Add handling of IP header with option field in netvsc_set_hash()

[Haiyang Zhang <haiyangz@microsoft.com>]

> -----Original Message-----
> From: David Miller [mailto:davem@davemloft.net]
> Sent: Friday, August 22, 2014 12:31 AM
> To: Haiyang Zhang
> Cc: netdev@vger.kernel.org; KY Srinivasan; olaf@aepfle.de;
> jasowang@redhat.com; linux-kernel@vger.kernel.org; driverdev-
> devel@linuxdriverproject.org
> Subject: Re: [PATCH net-next] hyperv: Add handling of IP header with
> option field in netvsc_set_hash()
> 
> From: Haiyang Zhang <haiyangz@microsoft.com>
> Date: Tue, 19 Aug 2014 20:53:55 +0000
> 
> > @@ -200,12 +202,18 @@ static bool netvsc_set_hash(u32 *hash, struct
> sk_buff *skb)
> >  	iphdr = ip_hdr(skb);
> >
> >  	if (iphdr->version == 4) {
> > -		if (iphdr->protocol == IPPROTO_TCP)
> > +		data = (u8 *)&iphdr->saddr;
> > +		if (iphdr->protocol == IPPROTO_TCP) {
> >  			data_len = 12;
> > -		else
> > +			if (iphdr->ihl > 5) {
> > +				memcpy(dbuf, &iphdr->saddr, 8);
> > +				memcpy(&dbuf[8], &tcp_hdr(skb)->source, 4);
> 
> This is rediculous.
> 
> Make hash_comp() take a void pointer for the buffer.
> 
> Then your code is simply:
> 
> 	be32 dbuf[2];
> 
> 	dbuf[1] = iph->saddr;
> 	dbuf[2] = iph->daddr;
> 	dbuf[3] = *(be32 *)tcph->source;
> 
> 	*hash = comp_hash(netvsc_hash_key, HASH_KEYLEN, dbuf, 12);
> 
> No special cases for IP options or any garbage like that.

I have submitted a revised patch with the suggested changes.

Thanks,
- Haiyang