Re: [PATCH] iproute2: support xfrm upper protocol gre key

[Ben Hutchings <bhutchings@solarflare.com>]

On Tue, 2010-11-23 at 10:13 -0800, Stephen Hemminger wrote:
> On Tue, 23 Nov 2010 18:44:44 +0200
> Timo Teräs <timo.teras@iki.fi> wrote:
> 
> > On 11/23/2010 06:24 PM, Stephen Hemminger wrote:
> > > On Tue, 23 Nov 2010 17:02:39 +0200
> > > Timo Teräs <timo.teras@iki.fi> wrote:
> > > 
> > >> +	case IPPROTO_GRE:
> > >> +		if (sel->sport_mask || sel->dport_mask) {
> > >> +			struct in_addr key;
> > >> +			key.s_addr = htonl((ntohs(sel->sport) << 16) + ntohs(sel->dport));
> > >> +			inet_ntop(AF_INET, &key, abuf, sizeof(abuf));
> > >> +			fprintf(fp, "key %s ", abuf);
> > >> +		}
> > > 
> > > The GRE key is not really an IPv4 address. Why should the utilities
> > > use IPv4 address manipulation to format/scan it.  It makes more sense
> > > to me to just use u32 an do the necessary ntohl.
> > 
> > This is pretty much how iptunnel.c does it, so I copied the code. Would
> > you prefer to format it as single u32 number? Or use something else for
> > formatting it similar to IPv4?
> > 
> > In either case, we should change iptunnel.c to match ipxfrm.c. It'll be
> > easier if both parts handling the gre key treat it equivalently.
> > 
> > I think Cisco does indeed treat it as u32 number in the configurations.
> > So I'm okay updating this patch, and fixing iptunnel.c side too. We
> > might still want to keep the parsing of ipv4 format to keep backwards
> > compatibility.
> 
> My preference would be to take both dotted quad and a single
> number.

inet_aton() covers that.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
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