Re: [PATCH net-next 4/6] 6lowpan: add udp warning for elided checksum

[Alexander Aring <alex.aring@gmail.com>]

On Thu, Nov 14, 2013 at 08:32:01AM -0800, Joe Perches wrote:
> On Thu, 2013-11-14 at 16:48 +0100, Alexander Aring wrote:
> > Bit 5 of "UDP LOWPAN_NHC Format" indicate that the checksum can be elided.
> > The host need to calculate the udp checksum afterwards but this isn't
> > supported right now.
> []
> > diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
> []
> > @@ -448,9 +448,14 @@ lowpan_uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh)
> >  		pr_debug("uncompressed UDP ports: src = %d, dst = %d\n",
> >  			 ntohs(uh->source), ntohs(uh->dest));
> >  
> > -		/* copy checksum */
> > -		memcpy(&uh->check, &skb->data[0], 2);
> > -		skb_pull(skb, 2);
> > +		/* checksum */
> > +		if (tmp & LOWPAN_NHC_UDP_CS_C) {
> > +			pr_debug("checksum elided currently not supported");
> 
> This looks like it could need ratelimiting
> Also, it should end in "\n".  Maybe use:
> 
> 	pr_debug_ratelimited("checksum elided currently not supported\n");

ah, yes. I will change it.

Thanks

- Alex