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

From: Daniel Borkmann <[email-masked]>
Date: Fri, 28 Jun 2013 17:53:39 +0200

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 ...
>
> Thanks Daniel, seems sensible.  Just trivial comments...

Ok, thanks.

> []
>
>> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> []
>
> Should any other include other than net/addrconf be needed?

I'm not sure I understand this question.

>> +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,
and by that, we stay compatible in behaviour.

>> +	u8 off = 0;
>> +
>> +	fmt++;
>> +	while (isalpha(*++fmt)) {
>> +		switch (*fmt) {
>> +		case 'p':
>> +			have_p = true;
>> +			break;
>> +		case 'f':
>> +			have_f = true;
>> +			break;
>> +		case 's':
>> +			have_s = true;
>> +			break;
>> +		case 'c':
>> +			have_c = true;
>> +			break;
>> +		}
>> +	}
>
>