Mercurial > hg > dhcpcd
view LICENSE @ 5525:26b5d9bc2985 draft
privsep: Send all log messages to the privileged actioneer
If dhcpcd starts and no syslogd implementation is running then
various syscall filters could be triggered when dhcpcd wants to syslog
and it's already in a chroot.
Not all libc openlog implementations support LOG_NDELAY and
openlog does not return an error code and can also mask errno back to 0.
So we have no way of knowing if we have a syslog connection or not.
This means we cannot cache the connection at startup because syslog itself
will try and open if no connection.
As such, all logging is now directed to the dhcpcd privileged actioneer
process which will handle all the syslog and log file writing actions.
The only downside of this approach (other than an extra fd per process)
is that we no longer know which PID raised the message. While we could
put the correct PID in the logfile as we control the API, we cannot
put it into syslog as we cannot control that API.
As all privsep errors should log which function they came from this
will hopefully not be an issue as on the happy path only the master
process will log stuff.
| author | Roy Marples <roy@marples.name> |
|---|---|
| date | Fri, 30 Oct 2020 03:43:51 +0000 |
| parents | 555d7d1a4939 |
| children |
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Copyright (c) 2006-2020 Roy Marples <roy@marples.name> All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.