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From: jmf@free-gate.com (Jean-Marc Frailong)
To: Dan Busarow <dan@dpcsys.com>
Cc: hackers@FreeBSD.ORG
Subject: Re: ISC dhcp, AF_UNSPEC & bpf bugs 
Date: Sat, 08 Jun 1996 18:18:46 GMT
Organization: FreeGate Corp.
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On Sat, 8 Jun 1996 00:04:02 -0700 (PDT), you wrote:

>On Fri, 7 Jun 1996, David Greenman wrote:
>Since user applications should _always_ use htons or nstoh (I don't believe
>anyone has ever disputed that), the libary and system calls should _always_ 
>return network order.
>
>So system/system or system/library calls should _always_ expect to receive
>their natural byte order (network) and not use a user (application) level 
>function (nstoh).

Yes, the problem is not really what is done inside the kernel (this is

a taste issue), but what is visible to applications. In this respect, 
the current BPF behaviour is broken since all network apps expect
strict network byte order.

This can be fixed in bpf.c only, by adding a byte swap for the 
Ethernet case in bpf_movein. This fix breaks a minimal number of
applications. AFAIK, in 2.1R, the only users of bpf writes are rarpd
and rbootd, with one-liner fixes.

Changing the kernel semantics for AF_UNSPEC is more tricky, and I am
not confident of having stepped through all the implications. Also,
there may be more changes for -current due to IPX & ATALK support.

What is the right way to proceed on this ? I am new to the FreeBSD
scene, and would appreciate some info on the 'proper procedure' :-)

In parallel, I'll send a message to the ISC DHCP list mentionning the
application-level workaround for FreeBSD.

Jean-Marc Frailong
jmf@free-gate.com