Re: follow-up: discrepancy with POSIX

Rick Jones
2007-09-19T18:39:31Z

Andi Kleen wrote:
> On Wed, Sep 19, 2007 at 11:02:00AM -0700, Ulrich Drepper wrote:
>
>>>on UDP/RAW and it's certainly possible to connect() to that.
>>
>>Where do you get this from? And where is this implemented? I don't
>
>
> Sorry it's actually loopback, not broadcast as implemented in Linux.
> In Linux it's implemented in ip_route_output_slow(). Essentially
> converted to 127.0.0.1
>
> I think it's traditional BSD behaviour but couldn't find it on
> a quick look in FreeBSD source (but haven't looked very intensively)

One has to set their way-back machine pretty far back to find the *BSD
bits which used 0.0.0.0 as the "all nets, all subnets" (to mis-use a
term) broadcast IPv4 address when sending. Perhaps as far back as the
time before HP-UX 7 or SunOS4. The bit errors in my dimm memory get
pretty dense that far back...

It has hung-on in various places (stacks) as an "accepted" broadcast IP
in the receive path, but not the send path for quite possibly decades now.

rick jones