[syslog-ng] syslog-ng 3.3.0beta2 chroot

[Balazs Scheidler]

Hi,

On Fri, 2011-09-16 at 11:02 +0100, Dave Haywood wrote:
> Hi,
> 
>    I have compiled syslog-ng 3.3.0beta2 under RHEL AS 4.8 (don't 
> ask) and am having a possible chroot() issue.
> 
>    syslog-ng is running chroot as a non-root user.  All the build 
> libraries etc (there were a lot to get this to run under RHEL 4.8) 
> are under /usr/local.
> 
>    I already run syslog-ng 2.0.9 under RHEL AS 4.9.
> 
>    I am seeing differences between the 2.0.9 and 3.3.0b2 releases.  
> The differences with 3.3.0b2 are:
>      1) daemon seems to switch user *before* binding the network 
> interfaces.  This means I can't bind to TCP/UDP ports < 1024.

Yes, that was changed in 3.0 a couple of years ago, because this way
SIGHUP couldn't work (no files in the chrooted directory).

The alternative to do this is to enable capability management (e.g.
--enable-linux-caps) and supply the necessary capability to the non-root
daemon. 

The defaults should work.

>      2) daemon chroot()s before loading the syslog-ng.conf file.  
> This means I have to mount the config dir under the chroot() dir.

That's right.

> 
>    So, my questions are:
>      1) Is the behaviour I describe in 3.3.30b2 intentional or could 
> this be a problem with my environment?
>      2) Why has the behaviour changed in this way?
>      3) If the daemon were to:
>              read the config file
>              bind the network interfaces
>         as root *before* dropping privelege and doing the chroot() 
> couldn't a lot of the chroot() hastle (below) be avoided?
> 
>    I have 3.3.0b2 running chroot() but only by:
>      mount -o bind /lib /chrootdir/lib
>      mount -o bind /usr/local /chrootdir/usr/local
>      mount -o bind /dev /chrootdir/dev
>      changing the syslog-ng.conf TCP/UDP listen ports to be > 1024

-- 
Bazsi