udhcpc is disrespecting --retries, unless -n is passed as well

[Michael D. Setzer II]

On 6 Aug 2013 at 17:40, John Spencer wrote:

Date sent:      	Tue, 06 Aug 2013 17:40:47 +0200
From:           	John Spencer <maillist-busybox at barfooze.de>
To:             	"Michael D. Setzer II" 
<mikes at kuentos.guam.net>
Copies to:      	busybox <busybox at busybox.net>
Subject:        	Re: udhcpc is disrespecting --retries, unless -n is 
passed as well

> On 08/06/2013 12:08 PM, Michael D. Setzer II wrote:
> > On 6 Aug 2013 at 9:44, John Spencer wrote:
> >
> > Date sent:	Tue, 06 Aug 2013 09:44:04 +0200
> > From:	John Spencer<maillist-busybox at barfooze.de>
> > To:	busybox<busybox at busybox.net>
> > Subject:	udhcpc is disrespecting --retries, unless -n is passed as
> > well
> >
> >> udhpc is looping forever witout respecting the number of retries
> >> given. only passing -n makes it exit after the max number of
> >> retries.
> >>
> >> this is pretty counterintuitive. took me about 2 hours to track
> >> down this bug because all the funky CFLAGS and LDFLAGS used by BB
> >> even when doing a debug build make gdb behave very odd and the
> >> function has a huge loop with dozens of gotos and possible exits. i
> >> had to explore the buildlogs and rip out the commands executed to
> >> strip all those debug killer CFLAGS away.
> >
> > I use the udhcpcd -n -t 8 -T 5 -i $variablewithinterface -s
> > ./udhcpc.sh
> >
> > Originally, I just had the -n -i -s options, but had a user that
> > wasn't gettting the ip address on the initial boot process. Hoping
> > this additional options will make it more robust.
> 
> 
> now we have the opposite situation: a user (me) cannot even login to
> his machine because udhcpc spawned from init loops forever instead of
> exiting after 3 tries as it should. there is nothing at all that
> indicates wtf is happening there and why udhcpc is ignoring the passed
> option. the retries option help text does not explain that it only
> works in combination with -n.
> 
> since the option "-t 0" (0 retries means indefinite retries) has been
> added recently (see commit 1c7a58dfb82ea04c525e0c19f94f2d800dee99e3 by
> openwrt folks), having the -n option seems redundant. so removing -n
> and adding a hint about the -t 0 switch instead seems like the best
> solution.
> 

My understanding is that the udhcpc is set to run in a loop without 
the -n because the IP is not permanent. You get the lease for a 
fixed amount of time, and it has to be renewed occassionally, so 
that is why it needs to continue to run. 



+----------------------------------------------------------+
  Michael D. Setzer II -  Computer Science Instructor      
  Guam Community College  Computer Center                  
  mailto:mikes at kuentos.guam.net                            
  mailto:msetzerii at gmail.com
  http://www.guam.net/home/mikes
  Guam - Where America's Day Begins                        
  G4L Disk Imaging Project maintainer 
  http://sourceforge.net/projects/g4l/
+----------------------------------------------------------+

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