svn commit: r239356 - head/sbin/dhclient

[John Baldwin]

On Friday, August 17, 2012 1:02:14 pm Ian Lepore wrote:
> On Fri, 2012-08-17 at 15:53 +0000, John Baldwin wrote:
> > Author: jhb
> > Date: Fri Aug 17 15:53:43 2012
> > New Revision: 239356
> > URL: http://svn.freebsd.org/changeset/base/239356
> > 
> > Log:
> >   Fix dhclient to properly exit and teardown the configured lease when
> >   link is lost.  devd will start a new dhclient instance when link is
> >   restored.
> >   
> >   PR:		bin/166656
> >   Submitted by:	Peter Jeremy (mostly)
> >   Reviewed by:	brooks (earlier version from Peter)
> >   MFC after:	1 month
> > 
> > Modified:
> >   head/sbin/dhclient/dhclient.c
> > 
> > Modified: head/sbin/dhclient/dhclient.c
> > ==============================================================================
> > --- head/sbin/dhclient/dhclient.c	Fri Aug 17 14:22:56 2012	(r239355)
> > +++ head/sbin/dhclient/dhclient.c	Fri Aug 17 15:53:43 2012	(r239356)
> > @@ -278,6 +278,11 @@ routehandler(struct protocol *p)
> >  			    ifi->name);
> >  			goto die;
> >  		}
> > +		if (!interface_link_status(ifi->name)) {
> > +			warning("Interface %s is down, dhclient exiting",
> > +			    ifi->name);
> > +			goto die;
> > +		}
> >  		break;
> >  	case RTM_IFANNOUNCE:
> >  		ifan = (struct if_announcemsghdr *)rtm;
> > @@ -316,6 +321,8 @@ routehandler(struct protocol *p)
> >  
> >  die:
> >  	script_init("FAIL", NULL);
> > +	if (ifi->client->active)
> > +		script_write_params("old_", ifi->client->active);
> >  	if (ifi->client->alias)
> >  		script_write_params("alias_", ifi->client->alias);
> >  	script_go();
> 
> I think the attached patch should give the same result without needing
> to create/destroy a socket to check the link status every time a routing
> info message arrives.  I've actually had this patch in my head for
> several years, I just hadn't gotten around to submitting it yet.

Hmm, OpenBSD does check that, but they also seem to verify it via SIOCGMEDIA
as well.  Do we think this is as reliable?  In the kernel we only seem to
honor this if the NIC explicitly supports the capability:

#define RT_LINK_IS_UP(ifp)	(!((ifp)->if_capabilities & IFCAP_LINKSTATE) \
				 || (ifp)->if_link_state == LINK_STATE_UP)

Also, I don't think routing info messages are all that common of an event are they?

-- 
John Baldwin