Re: DragonFly-2.1.1.346.g4d1d7 master usr.sbin/dntpd client.h defs.h dntpd.8 main.c socket.c

["Simon 'corecode' Schubert" <corecode@xxxxxxxxxxxx>]

Sepherosa Ziehau wrote:
> On Fri, Jan 9, 2009 at 8:19 PM, Simon 'corecode' Schubert
> <corecode@fs.ei.tum.de> wrote:
> > Matthias Schmidt wrote:
> > > commit 4d1d74ba3c1fe85df343e4059c80bc704eec0312
> > > Author: Matthias Schmidt <matthias@dragonflybsd.org>
> > > Date:   Fri Jan 9 12:35:25 2009 +0100
> > >
> > >    Add IPv6 support to dntpd
> > >        This commit allows dntpd to work with either IPv4 or IPv6 NTP
> > > servers.  I added
> > >    two new command line switches (-4/-6) to force dntpd to use only v4/v6
> > > addresses.
> > >    Thanks to sephe@ for some good hints.
> > Are you sure this works if the ipv6 server is unreachable?  I don't think
> > that a connect(2) on a udp socket will find that out.  You'd actually have
>
> udp_socket() only sets up a UDP socket; by calling connect(2) we could
> receive ICMP error and use write(2) like functions.  As far as I
> understand the code, it never intends to verify the reachability of
> the server.

But it has to do that now!  The DNS might return ipv6 and ipv4, but the 
ipv4 one is only reachable.  So you *have* to check availability, 
otherwise it might fail.

cheers
  simon

--
  <3 the future  +++  RENT this banner advert  +++   ASCII Ribbon   /"\
  rock the past  +++  space for low €€€ NOW!1  +++     Campaign     \ /
Party Enjoy Relax   |   http://dragonflybsd.org      Against  HTML   \
Dude 2c 2 the max   !   http://golden-apple.biz       Mail + News   / \