Re: follow-up: discrepancy with POSIX

Andi Kleen
2007-09-19T17:27:11Z

On Wed, Sep 19, 2007 at 09:49:09AM -0700, Ulrich Drepper wrote:
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> Andi Kleen wrote:
> > The standard way to undo connect is to use AF_UNSPEC. Code to handle
> > that for dgram sockets is there. It's the same code for v4 and v6.
>
> I quoted the standard and it does not say anything about AF_UNSPEC. So
> you cannot simply make such broad statements.

Ok "standard" was perhaps a poor choice of words.

AF_UNSPEC used to be introduced long ago by Alan based on some early
POSIX draft iirc.

Also incidentially it's a null address:

include/linux/socket.h:#define AF_UNSPEC 0

> But the spec calls for a "null address" to be used and that's in my
> understanding something different from using AF_UNSPEC.

memset(&sockaddr, 0, sizeof(sockaddr)) should give you AF_UNSPEC

-Andi