Re: [BProc] Re: broadcast in startup files (beoboot)

[Michal J. <mi...@ha...>]

On Tue, Aug 17, 2004 at 03:25:06PM -0600, er...@he... wrote:
> 
> How about optional?  If the addresses are there, do something, else
> ignore the interface and presume some other part of the OS setup has
> configured it.

Hm, I always though that the reason why this is in a clustermatic
config file is that beosrv, and possibly other pieces, need to know
on which interface to talk to a cluster and how it is configured.
If the other part is not required then indeed this may be configured
somewewhere else but this has a much higher probability that
something will get out-of-sync.  If you will need change something
you have to remember to change few different places.

> I think it's reasonable to phase it out.

This seems like a feasibly but quite radical approach and people
will do get some "strange" errors.  A global search-and-replace
on one file will be not enough to reconfigure networking as you
will need to provide a range of IP numbers for cluster nodes.
Even if you will not forget about that other location then typos
are not something unheard of.

> 
> Yeah, random values are bad.

So here is a promissed replacement for finding BCAST without ipcalc.
One of reasons I used awk is that it lives in /bin/awk (although
some other things presume that /usr/bin is already available).


--- beoboot-cm1.9/rc.clustermatic.bk	2004-08-16 09:45:35.000000000 -0600
+++ beoboot-cm1.9/rc.clustermatic	2004-08-17 21:40:04.016426648 -0600
@@ -155,8 +155,22 @@
 		echo >&2 "Error: No netmask given for interface."
 		exit 1
 	    fi
-	    #BCAST=`ipcalc --broadcast $ADDR $NMSK | sed -e 's/.*=//'`
-	    if ifconfig $IF $ADDR netmask $NMSK; then
+	    BCAST=`echo $ADDR $NMSK | awk '
+	    function octstonum(octs,     a)
+	    {
+		split(octs, a, /\./);
+		return  ((a[1]*0x100 + a[2])*0x100 + a[3])*0x100 + a[4];
+	    }
+	    { 
+		bcast = or(octstonum($1), xor(octstonum($2), 0xffffffff));
+		printf ("%d.%d.%d.%d",
+		    rshift(and(bcast, 0xff000000), 24),
+		    rshift(and(bcast, 0x00ff0000), 16),
+		    rshift(and(bcast, 0x0000ff00), 8),
+		    and(bcast, 0x000000ff));
+	    }
+	    '`
+	    if ifconfig $IF $ADDR netmask $NMSK broadcast $BCAST; then
 		Xsuccess
 	    else
 		Xfailure


The above does work on 64-bit machines too.

Actually 'ifconfig' will be just as happy with an output of
'print or(octstonum($1), xor(octstonum($2), 0xffffffff));' for
$BCAST so splitting that for octets is not really necessary and is
done mostly for benefits of debugging.  The following, simpler,
patch works equally well.:

--- beoboot-cm1.9/rc.clustermatic.bk	2004-08-16 09:45:35.000000000 -0600
+++ beoboot-cm1.9/rc.clustermatic	2004-08-17 22:15:53.438664800 -0600
@@ -155,8 +155,17 @@
 		echo >&2 "Error: No netmask given for interface."
 		exit 1
 	    fi
-	    #BCAST=`ipcalc --broadcast $ADDR $NMSK | sed -e 's/.*=//'`
-	    if ifconfig $IF $ADDR netmask $NMSK; then
+	    BCAST=`echo $ADDR $NMSK | awk '
+	    function octstonum(octs,     a)
+	    {
+		split(octs, a, /\./);
+		return  ((a[1]*0x100 + a[2])*0x100 + a[3])*0x100 + a[4];
+	    }
+	    { 
+		print or (octstonum($1), xor(octstonum($2), 0xffffffff));
+	    }
+	    '`
+	    if ifconfig $IF $ADDR netmask $NMSK broadcast $BCAST; then
 		Xsuccess
 	    else
 		Xfailure

  Michal