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Re: chroot'ed environment?
From: don () paranoia com (don () paranoia com)
Date: Thu, 20 Apr 1995 03:32:16 -0500 (CDT)


Excerpted from 'man 3 openlog' on an AIX 3.2.5 system, but it should be
in any BSD4.3 system:

  #include <syslog.h>
  
  int openlog (ID, LogOption, Facility)
  char *ID;
  int LogOption, Facility;
...
  LogOption     Specifies a bit field that indicates logging options.
  The values of LogOption are:
...
  LOG_NDELAY    Opens the connection to the syslogd command immediate-
  ly, instead of when the first  message is logged.  This option is
  useful for  programs  that need to manage the order in which file
  descriptors are allocated.
...

So if you call  openlog(argv[0],LOG_NDELAY,LOG_DAEMON);  the LOG_NDELAY
will open /dev/log *now* (presumably before you chroot()).  And as we all
know, open file descriptors are not affected by a chroot()....

                              Valdis Kletnieks
                              Computer Systems Engineer
                              Virginia Tech

Come to think of it, 'sfingerd' (ftp://hplyot.obspm.fr/net/sfingerd*.tar.gz)
uses this technique, and has been running here at paranoia.com for a while
now, I believe.  Works quite well.


Michael E. Glasgow     --     don () paranoia com
                              http://www.paranoia.com



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