Subject: Re: [PATCH] ss: Enclose IPv6 address in brackets

From: Stephen Hemminger <[email-masked]>
Date: Tue, 1 Aug 2017 07:41:45 -0700

On Tue, 1 Aug 2017 11:11:03 +0000
David Laight <[email-masked]> wrote:

> From: Florian Lehner
> > Sent: 29 July 2017 13:29
> > This patch adds support for RFC2732 IPv6 address format with brackets
> > for the tool ss. So output for ss changes from
> > 2a00:1450:400a:804::200e:443 to [2a00:1450:400a:804::200e]:443 for IPv6
> > addresses with attached port number.
> > 
> > Signed-off-by: Lehner Florian <[email-masked]>
> > ---
> >  misc/ss.c | 6 +++++-
> >  1 file changed, 5 insertions(+), 1 deletion(-)
> > 
> > diff --git a/misc/ss.c b/misc/ss.c
> > index 12763c9..db39c93 100644
> > --- a/misc/ss.c
> > +++ b/misc/ss.c
> > @@ -1059,7 +1059,11 @@ static void inet_addr_print(const inet_prefix *a,
> > int port, unsigned int ifindex
> >  			ap = format_host(AF_INET, 4, a->data);
> >  		}
> >  	} else {
> > -		ap = format_host(a->family, 16, a->data);
> > +		if (a->family == AF_INET6) {
> > +			sprintf(buf, "[%s]", format_host(a->family, 16, a->data));
> > +		} else {
> > +			ap = format_host(a->family, 16, a->data);
> > +		}
> >  		est_len = strlen(ap);  
> ...
> 
> There are some strange things going on with global variables if this works at all.
> The text form of the address is in buf[] in one path and *ap in the other.
> 
> One option might be to call format_host() then use strchr(ap, ':')
> to add [] if the string contains any ':'.
> 
> 	David
> 

That sounds like a better solution.

Also what about IN6ADDR_ANY