[PATCH v2 0/9] error logging fixes

[Laine Stump <laine@redhat.com>]

There are two topics covered here:

1) If a logFile is set, passt's behavior has been to send all error
messages there, and *not* to stderr. This makes it difficult for
another program that is exec'ing passt (and setting it to log to a
file) to report useful error messages when passt fails. The first
patch makes a simple change to the logging functions that checks a
global bool that is set true after all initialization is completed.

2) All the rest of the patches eliminate use of the blanket usage()
function when a commandline error is encountered (and add in
specific/details error messages when previously usage() was all that
was logged).

Laine Stump (9):
  log to stderr until process is daemonized, even if a logfile is set
  add errexit() to log an error message and exit with a single call
  eliminate most calls to usage() in conf()
  make conf_ports() exit immediately after logging error
  make conf_pasta_ns() exit immediately after logging error
  make conf_ugid() exit immediately after logging error
  make conf_netns_opt() exit immediately after logging error
  log a detailed error (not usage()) when there are extra non-option
    arguments
  convert all remaining err() followed by exit() to errexit()

 conf.c      | 471 ++++++++++++++++++++--------------------------------
 isolation.c |  78 ++++-----
 log.c       |  33 ++--
 log.h       |   2 +
 netlink.c   |   3 +-
 passt.c     |  18 +-
 pasta.c     |  21 +--
 tap.c       |  30 ++--
 8 files changed, 258 insertions(+), 398 deletions(-)

-- 
2.39.1