Re: [PATCH net-next 3/3] vxlan: virtual extensible lan

[Chris Wright <chrisw@redhat.com>]

* Stephen Hemminger (shemminger@vyatta.com) wrote:
> Chris Wright <chrisw@redhat.com> wrote:
> > > +/* Propogate ECN bits out */
> > > +static inline u8 vxlan_ecn_encap(u8 tos,
> > > +				 const struct iphdr *iph,
> > > +				 const struct sk_buff *skb)
> > > +{
> > > +	u8 inner = vxlan_get_dsfield(iph, skb);
> > > +
> > > +	return INET_ECN_encapsulate(tos, inner);
> > > +}
> > 
> > Goal is to be RFC 6040 compliant, and it looks like some edge cases aren't
> > met, for example, should drop on decap when inner is not supporting ECN
> > and outer has set CE.
> 
> The code was taken from existing GRE in Linux.
> Looks like both VXLAN and GRE need to handle that.

Right.

> > > +/* Callback from net/ipv4/udp.c to receive packets */
> > > +	/* Mark socket as an encapsulation socket. */
> > > +	udp_sk(sk)->encap_type = UDP_ENCAP_L2TPINUDP;
> > 
> > I don't think we need this particular encap_type value, just != 0
> 
> Is there any value in defining new value?

No, more the propagation of L2TP constant starts to look like cargo cult
programming.  IOW, no special meaning in this context.