Date: Thu, 12 Jan 2012 21:00:30 GMT From: Matthew Story <matthewstory@gmail.com> To: freebsd-bugs@FreeBSD.org Subject: Re: conf/164048: /etc/rc.d/hostid is not symlink aware Message-ID: <201201122100.q0CL0US7029299@freefall.freebsd.org>
next in thread | raw e-mail | index | archive | help
The following reply was made to PR conf/164048; it has been noted by GNATS.
From: Matthew Story <matthewstory@gmail.com>
To: Dirk-Willem van Gulik <dirkx@webweaving.org>
Cc: freebsd-bugs@freebsd.org, freebsd-gnats-submit@freebsd.org
Subject: Re: conf/164048: /etc/rc.d/hostid is not symlink aware
Date: Thu, 12 Jan 2012 15:51:48 -0500
--20cf307f3aeec4ba1b04b65aeadd
Content-Type: text/plain; charset=ISO-8859-1
On Thu, Jan 12, 2012 at 2:47 PM, Dirk-Willem van Gulik <dirkx@webweaving.org
> wrote:
>
> On 12 jan. 2012, at 17:48, Matthew Story wrote:
>
> > On Thu, Jan 12, 2012 at 3:15 AM, Dirk-Willem van Gulik <
> dirkx@webweaving.org> wrote:
>
[...snip]
> Totally understood - but wanted to stay close to the behavior of
> dhclient-script as I understand it. And this happens to also make the
> behavior of /etc/rc.d/sshd on first run the same. Keep in mind that one can
> always set the rc variable.
>
it makes sense to test for existence (and not readability) for rc.d/sshd,
as it goes on to create files if they do not exist:
if [ -f /etc/ssh/ssh_host_key ]; then
echo "You already have an RSA host key" \
"in /etc/ssh/ssh_host_key"
echo "Skipping protocol version 1 RSA Key Generation"
else
/usr/bin/ssh-keygen -t rsa1 -b 1024 \
-f /etc/ssh/ssh_host_key -N ''
fi
in the existing implementation of rc.d/hostid, it does not create the file
on ``start'' if it does not exist, so detection of readability is more
correct (although in the typical use-case e.g. running as root, existence
and readability are ostensibly synonymous).
> [...snip]
>
> Agreed - as _set is better.
> [...snip]
>
So the question is not about respecting symlinks, but wether or not a
``host_id_file'' should be created if one does not exist, for the ``start''
command. I'm not sure if this behavior is desirable, considering that the
de facto behavior is to respect hardware derived ``smbios.system.uuid'',
and writing that value to disk would potentially require an additional
reset on hardware change.
As you can easily generate a ``host_id_file'' if one does not exist by
invoking the ``reset'' command, and the sysctl is set at start properly,
either from ``host_id_file'', hardware or via the ``uuidgen'' program, this
seems superfluous to me ... but I defer to the maintainer.
--
regards,
matt
--20cf307f3aeec4ba1b04b65aeadd
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable
On Thu, Jan 12, 2012 at 2:47 PM, Dirk-Willem van Gulik <span dir=3D"ltr">&l=
t;<a href=3D"mailto:dirkx@webweaving.org">dirkx@webweaving.org</a>></spa=
n> wrote:<br><div class=3D"gmail_quote"><blockquote class=3D"gmail_quote" s=
tyle=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class=3D"im"><br>
On 12 jan. 2012, at 17:48, Matthew Story wrote:<br>
<br>
> On Thu, Jan 12, 2012 at 3:15 AM, Dirk-Willem van Gulik <<a href=3D"=
mailto:dirkx@webweaving.org">dirkx@webweaving.org</a>> wrote:<br></div><=
/blockquote><div>[...snip]=A0</div><blockquote class=3D"gmail_quote" style=
=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class=3D"im"></div>Totally understood - but wanted to stay close to th=
e behavior of dhclient-script as I understand it. =A0And this happens to al=
so make the behavior of /etc/rc.d/sshd on first run the same. Keep in mind =
that one can always set the rc variable.<br>
</blockquote><div><br></div><div>it makes sense to test for existence (and =
not readability) for rc.d/sshd, as it goes on to create files if they do no=
t exist:</div><div><br></div><div><div>=A0=A0 =A0if [ -f /etc/ssh/ssh_host_=
key ]; then</div>
<div>=A0=A0 =A0 =A0 =A0echo "You already have an RSA host key" \<=
/div><div>=A0=A0 =A0 =A0 =A0 =A0 =A0"in /etc/ssh/ssh_host_key"</d=
iv><div>=A0=A0 =A0 =A0 =A0echo "Skipping protocol version 1 RSA Key Ge=
neration"</div><div>=A0=A0 =A0else</div>
<div>=A0=A0 =A0 =A0 =A0/usr/bin/ssh-keygen -t rsa1 -b 1024 \</div><div>=A0=
=A0 =A0 =A0 =A0 =A0 =A0-f /etc/ssh/ssh_host_key -N ''</div><div>=A0=
=A0 =A0fi =A0</div></div><div><br></div><div>in the existing implementation=
of rc.d/hostid, it does not create the file on ``start'' if it doe=
s not exist, so detection of readability is more correct (although in the t=
ypical use-case e.g. running as root, existence and readability are ostensi=
bly synonymous).</div>
<div>=A0</div><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;=
border-left:1px #ccc solid;padding-left:1ex">[...snip]<br>
<div class=3D"im"><br>
</div>Agreed - as _set is better.<br>
<div class=3D"im">[...snip]</div></blockquote></div><div><br></div>So the q=
uestion is not about respecting symlinks, but wether or not a ``host_id_fil=
e'' should be created if one does not exist, for the ``start'&#=
39; command. =A0I'm not sure if this behavior is desirable, considering=
that the de facto behavior is to respect hardware derived ``smbios.system.=
uuid'', and writing that value to disk would potentially require an=
additional reset on hardware change.<div>
<br></div><div>As you can easily generate a ``host_id_file'' if one=
does not exist by invoking the ``reset'' command, and the sysctl i=
s set at start properly, either from ``host_id_file'', hardware or =
via the ``uuidgen'' program, this seems superfluous to me ... but I=
defer to the maintainer.<div>
<div><br></div>-- <br>regards,<br>matt<br>
</div></div>
--20cf307f3aeec4ba1b04b65aeadd--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201201122100.q0CL0US7029299>