Subject: Re: IP Firewalling and IP Filetering
To: matthew green <>
From: Jason Thorpe <>
List: current-users
Date: 06/10/1996 23:00:20
On Tue, 11 Jun 1996 14:20:33 +1000 
 matthew green <> wrote:

 >    i.e., in using if_unit & if_name, one might assume that "le" #0 and "le" #1
 >    are somehow related.
 > who cares if they are related ?  "Maybe I'm Missing Something ..."

And, really, it's probably wrong to assume they have any relationship at 
all.  But, like Matt said "Maybe I'm Missing Something ..."

 >    The implication of "if_xname" is that the number for the interface is
 >    not needed to indentify an interface, an interesting concept but is it
 >    really that much of a problem that we want to make portability of
 >    applications that much harder ?  (any programs like netstat will have to be
 >    altered to deal with this, for example).
 > hmm?
 > what does it matter what the interface is called ?

Oh, I see what he's getting at ... what if you had a program that read a 
struct ifnet out of kmem, for example, and you needed to piece the name 
back together, or whatever...

Umm .. I had to make some changes to netstat, sure...but, ironically 
enough, like the code in the kernel that did the same thing, the new code 
is actually smaller and less complex.  So, I'm not sure I really see a 
problem, except for the "Erk, this program is broken now."

Really, in the cases of programs that go groveling though kernel memory, 
have intimate (and sometimes perverse) knowledge of kernel data 
strctures, and what not, you're bound to run into incompatibility 
problems..."The cost of progress", I suppose... Avoiding incompatibility 
with more sane version identification is clearly something that we need 
to be more aware of.

----save the ancient forests -
Jason R. Thorpe                             
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