Re: [Qemu-devel] [PATCH] net/slirp: fix the error message when the prefix len is invalid

[Stefano Garzarella <sgarzare@redhat.com>]

On Fri, May 10, 2019 at 07:56:47AM +0200, Markus Armbruster wrote:
> Stefano Garzarella <sgarzare@redhat.com> writes:
> 
> > On Thu, May 09, 2019 at 04:54:35PM +0200, Markus Armbruster wrote:
> >> Stefano Garzarella <sgarzare@redhat.com> writes:
> >> 
> >> > Add a missing parentheses at the end of the error message,
> >> > when we have an invalid prefix len.
> >> >
> >> > Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> >> > ---
> >> >  net/slirp.c | 3 ++-
> >> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >> >
> >> > diff --git a/net/slirp.c b/net/slirp.c
> >> > index 95934fb36d..0f4ae0abc0 100644
> >> > --- a/net/slirp.c
> >> > +++ b/net/slirp.c
> >> > @@ -498,7 +498,8 @@ static int net_slirp_init(NetClientState *peer, const char *model,
> >> >      }
> >> >      if (vprefix6_len < 0 || vprefix6_len > 126) {
> >> >          error_setg(errp,
> >> > -                   "Invalid prefix provided (prefix len must be in range 0-126");
> >> > +                   "Invalid prefix provided "
> >> > +                   "(prefix len must be in range 0-126)");
> >> >          return -1;
> >> >      }
> >> 
> >> Preexisting: the error message fails to identify the offending
> >> parameter.  The user needs to make the connection to "ipv6-prefixlen"
> >> based on the fact that the only parameters with "prefix" in name or
> >> description are "ipv6-prefix" and "ipv6-prefixlen", and only the latter
> >> is a length.
> >> 
> >> What about "Parameter 'ipv6-prefixlen' expects a length below 127", or
> >> "Parameter 'ipv6-prefixlen' expects a value between 0 and 126"?
> >
> > "Parameter 'ipv6-prefixlen' expects a value between 0 and 126" should be
> > fine.
> >
> > Otherwise, since other errors didn't refer to the parameter name, we can
> > simply add IPv6 in this way:
> > "Invalid IPv6 prefix provided (IPv6 prefix len must be between 0 and 126)"
> 
> "len" is not a word.  Either say "ipv6-prefixlen", or say "IPv6 prefix
> length".
> 
> > But I'm fine also with your proposal.
> 
> It's just a suggestion.  Feel free to leave the error messages
> consistently vague (apply your patch as is), improve just this one, or
> improve more messages.

Your suggestions are very appreciated!

I'll resend this patch fixing this error message and I'll check also
the other messages.

Thanks,
Stefano