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

[Markus Armbruster]

Stefano Garzarella <address@hidden> writes:

> On Thu, May 09, 2019 at 04:54:35PM +0200, Markus Armbruster wrote:
>> Stefano Garzarella <address@hidden> writes:
>> 
>> > Add a missing parentheses at the end of the error message,
>> > when we have an invalid prefix len.
>> >
>> > Signed-off-by: Stefano Garzarella <address@hidden>
>> > ---
>> >  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.