Re: [PATCH 11/11] conf: Accept addresses enclosed by square brackets in port forwarding specifiers

[Stefano Brivio <sbrivio@redhat.com>]

On Thu, 25 Jul 2024 14:39:49 +1000
David Gibson <david@gibson.dropbear.id.au> wrote:

> On Wed, Jul 24, 2024 at 11:50:17PM +0200, Stefano Brivio wrote:
> > Even though we don't use : as delimiter for the port, making square
> > brackets unneeded, RFC 3986, section 3.2.2, mandates them for IPv6
> > literals. We want IPv6 addresses there, but some users might still
> > specify them out of habit.
> > 
> > Same for IPv4 addresses: RFC 3986 doesn't specify square brackets for
> > IPv4 literals, but I had reports of users actually trying to use them
> > (they're accepted by many tools).
> > 
> > Allow square brackets for both IPv4 and IPv6 addresses, correct or
> > not, they're harmless anyway.
> > 
> > Signed-off-by: Stefano Brivio <sbrivio@redhat.com>  
> 
> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> 
> > ---
> >  conf.c | 24 +++++++++++++++++-------
> >  1 file changed, 17 insertions(+), 7 deletions(-)
> > 
> > diff --git a/conf.c b/conf.c
> > index 3cf9ed8..338742e 100644
> > --- a/conf.c
> > +++ b/conf.c
> > @@ -209,14 +209,24 @@ static void conf_ports(const struct ctx *c, char optname, const char *optarg,
> >  
> >  		}
> >  
> > -		if (ifname == buf + 1)		/* Interface without address */
> > +		if (ifname == buf + 1) {	/* Interface without address */
> >  			addr = NULL;
> > -		else if (inet_pton(AF_INET, buf, addr))
> > -			af = AF_INET;
> > -		else if (inet_pton(AF_INET6, buf, addr))
> > -			af = AF_INET6;
> > -		else
> > -			goto bad;
> > +		} else {
> > +			p = buf;
> > +
> > +			/* Allow square brackets for IPv4 too for convenience */
> > +			if (*p == '[' && p[strlen(p) - 1] == ']') {
> > +				p[strlen(p) - 1] = 0;  
> 
> Nit: I think = '\0' would make the intention here clearer.

Right, fixed on merge.

-- 
Stefano