miss handling of the SIGHUP signal for sshd when sshd is started with a relative path sshd_config file

[Ben Lindstrom]

On Feb 25, 2009, at 2:04 AM, 施威 wrote:

>
> Hi
>
> I am just porting ssh-5.2 to my HPUX system.
>
>
> but while I'm doing it, I accidently  found a different handling of  
> the sshd for the SIGHUP signal when it is started with a "./ 
> sshd_config" and "/sshd_config".
>
> The problem is as following:
>
> root at sshpa6# uname -a
> HP-UX sshpa6 B.11.31 U 9000/800 2404418693 unlimited-user license
>
> root at sshpa6# /opt/ssh/sbin/sshd -f ./sshd_config                   
> ### ./sshd_config is a relative path
> root at sshpa6# ps -ef|grep sshd
>    root 12616     1  0 15:51:00 ?         0:00 /opt/ssh/sbin/sshd - 
> f ./sshd_config
>    root 12618 17401  0 15:51:03 pts/tb    0:00 grep sshd
> root at sshpa6# kill -HUP 12616
> root at sshpa6# ps -ef|grep sshd
>    root 12620 17401  0 15:51:12 pts/tb    0:00 grep sshd        ###  
> sshd is killed but not restarted as it should be.
>
> So is it a bug or a normal situation?
>

If I had the venture a guess it is because ./xxx is a relative, and  
after a chdir("/") it is no longer the same location when OpenSSH is - 
HUP it no longer knows where the configuration file is and thus  
terminates itself.

So yes, I would expect this behavior myself.

So the simply truth is you should always do:  /path/to/sshd -f /path/ 
to/sshd_config

- Ben