udhcpd: HOST_NAME support for static leases

Philippe Jounin philippe.jounin at orange.fr
Tue May 21 19:44:37 UTC 2019


Hello Denys,

That's perfect  !!
Thanks.

Just a question:
In line 69, [optlen = (opts ? 1+1+strnlen(opts, 120) : 0);], you choose 
to limit the hostname to 120 characters.

It seems more than enough, however it this not fully compliant with the 
RFC 2132 and 1035.
RFC 1035 limits the FQDN to 255 characters with labels limited to 63 
chars, while RFC2132 mentions that the HOSTNAME option may contain the 
domain name.

Is it a tradeoff to keep DHCP messages shorter than MTU ?

Best regards,
Philippe


        2.3.4 <https://tools.ietf.org/html/rfc1035#section-2.3.4>. Size
        limits



Various objects and parameters in the DNS have size limits.  They are
listed below.  Some could be easily changed, others are more
fundamental.

labels          63 octets or less
names           255 octets or less



      3.14 <https://tools.ietf.org/html/rfc2132#section-3.14>. Host Name
      Option



    This option specifies the name of the client.  The name may or may
    not be qualified with the local domain name (seesection 3.17  <https://tools.ietf.org/html/rfc2132#section-3.17>  for the
    preferred way to retrieve the domain name).  SeeRFC 1035  <https://tools.ietf.org/html/rfc1035>  for
    character set restrictions.

    The code for this option is 12, and its minimum length is 1.

     Code   Len                 Host Name
    +-----+-----+-----+-----+-----+-----+-----+-----+--
    |  12 |  n  |  h1 |  h2 |  h3 |  h4 |  h5 |  h6 |  ...
    +-----+-----+-----+-----+-----+-----+-----+-----+--



Le 21/05/2019 à 16:07, Denys Vlasenko a écrit :
>
> On Mon, May 20, 2019 at 6:30 PM Philippe Jounin 
> <philippe.jounin at orange.fr <mailto:philippe.jounin at orange.fr>> wrote:
>
>
>     Hello Denys,
>
>     Tested under a debian box: Works as expected with the
>     configuration file joined !!
>     Targets tried: debian, centOS, cisco routers
>
>      A few very minor remarks:
>        - with high verbose level (3v), log_static_leases dumps all
>     static leases, but is called for each new static lease. May be log
>     should be moved into add_static_lease.
>
>
> Done, please try current git.
>



---
L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
https://www.avast.com/antivirus
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.busybox.net/pipermail/busybox/attachments/20190521/4f93133c/attachment.html>


More information about the busybox mailing list