To: austin-review-l__AT__opengroup.org
From: nico-posix__AT__schottelius.org
Subject: Bug in TC2-d6 bind - bind a name to a socket
Reply-To: austin-group-l__AT__opengroup.org

   Bug report from : Nico Schottelius , cLinux

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@ page 1 line 0 section bind - bind a name to a socket objection {-1}

Problem:

bind should 'assign a name to a socket', but in particular environments it will fail, where it could succeed.

Long Description:

When opening a new socket, with type PF_UNIX
(sock = socket(PF_UNIX,SOCK_STREAM,0);) and one sets
the socket option SO_REUSEADDR
(setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &tmp, sizeof(tmp))),
bind does not honour this setting.

It is reported on irc channels, that SO_REUSEADDR is only supported on
PF_INET sockets and that's what I would claim a bug.

If a socket exists in the filesystem and no process is bound to
it, bind wail fail anyway.

This is especially problematic, when one is in an environment,
which is pre-startup (like beeing init) and one wants to use
sockets, but everything is mounted read-only.

So, if bind() would honour the option, it would be able
to bind() to a socket, which exists (as creating one on a
read-only filesystem is not possible).



Action:

Proposal:

Add better specification to either socket(7) or bind(2), which
explains the behaviour of bind, when this option is set
or even better: Specify, that bind should take care of this bit,
also when using PF_UNIX.

In general the socket(7) manpage should explain more in detail
or at least reference other documents (unix(7)?), which explain what the
option for a specific protocol does.