Re: [PATCH] man/man5/gai.conf: Labels have a label not a precedence

["Dr. David Alan Gilbert" <dave@treblig.org>]

* Alejandro Colomar (alx@kernel.org) wrote:
> Hi David,

Hi Alex,

> On Sun, Jan 04, 2026 at 10:04:38PM +0000, dg@treblig.org wrote:
> > From: "Dr. David Alan Gilbert" <dave@treblig.org>
> > 
> > The numeric value on a label entry is a label which is separate
> > from the precedences.  Labels are compared with other labels, not
> > precedences.
> 
> Is there any source to verify this?

The two I checked are:
  https://datatracker.ietf.org/doc/html/rfc3484#section-2.1
    is the RFC itself, and it talks about the Precedence and labels
as separate values.  Note how it's talking in terms of:

   If Precedence(A) > Precedence(B), we say that...
and
   The algorithms prefer to use a source address S with a destination
   address D if Label(S) = Label(D).

So it's label compared to label and precedence compared to precedence.

The corresponding bits of glibc are:
https://sourceware.org/git/?p=glibc.git;a=blob;f=nss/getaddrinfo.c;h=c0f496f96c752220e68bf0257d9ff1ffc624ebe6;hb=HEAD#l1525

where the label values are compared in Rule 5, and the precedence values
are compared in Rule 6.

Dave

> 
> Cheers,
> Alex
> 
> > 
> > Rename the field.
> > 
> > Signed-off-by: Dr. David Alan Gilbert <dave@treblig.org>
> > ---
> >  man/man5/gai.conf.5 | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/man/man5/gai.conf.5 b/man/man5/gai.conf.5
> > index 4aff0b0b9..ef330995d 100644
> > --- a/man/man5/gai.conf.5
> > +++ b/man/man5/gai.conf.5
> > @@ -26,7 +26,7 @@ .SH DESCRIPTION
> >  .P
> >  The keywords currently recognized are:
> >  .TP
> > -.BI label\~ netmask\~precedence
> > +.BI label\~ netmask\~label
> >  The value is added to the label table used in the RFC\ 3484 sorting.
> >  If any
> >  .B label
> > @@ -35,7 +35,7 @@ .SH DESCRIPTION
> >  All the label definitions
> >  of the default table which are to be maintained have to be duplicated.
> >  Following the keyword,
> > -the line has to contain a network mask and a precedence value.
> > +the line has to contain a network mask and a label value.
> >  .TP
> >  .BI precedence\~ netmask\~precedence
> >  This keyword is similar to
> > -- 
> > 2.52.0
> > 
> 
> -- 
> <https://www.alejandro-colomar.es>


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