Re: [PATCH net-next v3 1/2] lib: vsprintf: add IPv4/v6 generic %p[Ii]S[pfs] format specifier

[Joe Perches <joe@perches.com>]

On Fri, 2013-06-28 at 17:53 +0200, Daniel Borkmann wrote:
> On 06/28/2013 05:44 PM, Joe Perches wrote:
> > On Fri, 2013-06-28 at 14:05 +0200, Daniel Borkmann wrote:
> >> In order to avoid making code that deals with printing both, IPv4 and
> >> IPv6 addresses, unnecessary complicated as for example ...
[]
> > Should any other include other than net/addrconf be needed?
> I'm not sure I understand this question.

the #include <net/addrconf.h> indirectly
includes <linux/in.h> and <linux/in6.h>
but because this now uses struct sockaddr and family
it may be more sensible to directly include those.

No worries really, it works now.

> >> +char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
> >> +			 struct printf_spec spec, const char *fmt)
> >> +{
> > []
> >> +	char fmt6[2] = { fmt[0], '6'};
> >
> > This looks odd to me.  why not use a bool compressed
> > flag and identify this before the isalpha loop and not
> > have fmt6 at all?
> 
> Well, we have a bool called 'have_c' that identifies if 'c' was specified. To have
> the same behaviour as with %pI6, this is used to create a temporary fmt that we then
> can pass to ip6_string(). If you look at ip6_addr_string(), it's done the same way,

It's a little different than that.

> and by that, we stay compatible in behaviour.

That's slightly tricky, ip6_addr_string just needs "I" or "i"

But, your implementation, your choice,

cheers, Joe