NAME
krb5_initlog,
krb5_openlog,
krb5_closelog,
krb5_addlog_dest,
krb5_addlog_func,
krb5_log,
krb5_vlog,
krb5_log_msg,
krb5_vlog_msg —
Heimdal logging
functions
LIBRARY
Kerberos 5 Library (libkrb5, -lkrb5)
SYNOPSIS
#include <krb5/krb5.h>
typedef void
(*krb5_log_log_func_t)(
const
char *time,
const char
*message,
void
*data);
typedef void
(*krb5_log_close_func_t)(
void
*data);
krb5_error_code
krb5_addlog_dest(
krb5_context
context,
krb5_log_facility
*facility,
const char
*destination);
krb5_error_code
krb5_addlog_func(
krb5_context
context,
krb5_log_facility
*facility,
int min,
int max,
krb5_log_log_func_t log,
krb5_log_close_func_t
close,
void *data);
krb5_error_code
krb5_closelog(
krb5_context
context,
krb5_log_facility
*facility);
krb5_error_code
krb5_initlog(
krb5_context
context,
const char
*program,
krb5_log_facility
**facility);
krb5_error_code
krb5_log(
krb5_context
context,
krb5_log_facility
*facility,
int level,
const char *format,
...);
krb5_error_code
krb5_log_msg(
krb5_context
context,
krb5_log_facility
*facility,
char
**reply,
int level,
const char *format,
...);
krb5_error_code
krb5_openlog(
krb5_context
context,
const char
*program,
krb5_log_facility
**facility);
krb5_error_code
krb5_vlog(
krb5_context
context,
krb5_log_facility
*facility,
int level,
const char *format,
va_list arglist);
krb5_error_code
krb5_vlog_msg(
krb5_context
context,
krb5_log_facility
*facility,
char
**reply,
int level,
const char *format,
va_list arglist);
DESCRIPTION
These functions logs messages to one or more destinations.
The
krb5_openlog() function creates a logging
facility, that is used to log messages. A facility
consists of one or more destinations (which can be files or syslog or some
other device). The
program parameter should be the
generic name of the program that is doing the logging. This name is used to
lookup which destinations to use. This information is contained in the
logging
section of the
krb5.conf
configuration file. If no entry is found for
program,
the entry for
default
is used, or if that is missing
too,
SYSLOG
will be used as destination.
To close a logging facility, use the
krb5_closelog() function.
To log a message to a facility use one of the functions
krb5_log(),
krb5_log_msg(),
krb5_vlog(), or
krb5_vlog_msg(). The
functions ending in
_msg
return in
reply a pointer to the message that just got logged.
This string is allocated, and should be freed with
free().
The
format is a standard
printf()
style format string (but see the BUGS section).
If you want better control of where things gets logged, you can instead of using
krb5_openlog() call
krb5_initlog(), which
just initializes a facility, but doesn't define any actual logging
destinations. You can then add destinations with the
krb5_addlog_dest() and
krb5_addlog_func()
functions. The first of these takes a string specifying a logging destination,
and adds this to the facility. If you want to do some non-standard logging you
can use the
krb5_addlog_func() function, which takes a
function to use when logging. The
log function is called
for each message with
time being a string specifying the
current time, and
message the message to log.
close is called when the facility is closed. You can
pass application specific data in the
data parameter.
The
min and
max parameter are the
same as in a destination (defined below). To specify a max of infinity, pass
-1.
krb5_openlog() calls
krb5_initlog() and then
calls
krb5_addlog_dest() for each destination found.
Destinations
The defined destinations (as specified in
krb5.conf) follows:
-
-
STDERR
- This logs to the program's stderr.
-
-
FILE:
/file
-
FILE=
/file
- Log to the specified file. The form using a colon appends
to the file, the form with an equal truncates the file. The truncating
form keeps the file open, while the appending form closes it after each
log message (which makes it possible to rotate logs). The truncating form
is mainly for compatibility with the MIT libkrb5.
-
-
DEVICE=
/device
- This logs to the specified device, at present this is the
same as
FILE:/device
.
-
-
CONSOLE
- Log to the console, this is the same as
DEVICE=/dev/console
.
-
-
SYSLOG
[:priority[:facility]]
- Send messages to the syslog system, using priority, and
facility. To get the name for one of these, you take the name of the macro
passed to syslog(3), and
remove the leading
LOG_
(LOG_NOTICE
becomes
NOTICE
). The default values (as well as the values
used for unrecognised values), are ERR
, and
AUTH
, respectively. See
syslog(3) for a list of
priorities and facilities.
Each destination may optionally be prepended with a range of logging levels,
specified as
min-max/
. If the
level parameter to
krb5_log() is
within this range (inclusive) the message gets logged to this destination,
otherwise not. Either of the min and max valued may be omitted, in this case
min is assumed to be zero, and max is assumed to be infinity. If you don't
include a dash, both min and max gets set to the specified value. If no range
is specified, all messages gets logged.
EXAMPLES
[logging]
kdc = 0/FILE:/var/log/kdc.log
kdc = 1-/SYSLOG:INFO:USER
default = STDERR
This will log all messages from the
kdc program with level 0
to
/var/log/kdc.log, other messages will be logged to syslog
with priority
LOG_INFO
, and facility
LOG_USER
. All other programs will log all messages to
their stderr.
SEE ALSO
syslog(3),
krb5.conf(5)
BUGS
These functions use
asprintf() to format the message. If your
operating system does not have a working
asprintf(), a
replacement will be used. At present this replacement does not handle some
correct conversion specifications (like floating point numbers). Until this is
fixed, the use of these conversions should be avoided.
If logging is done to the syslog facility, these functions might not be
thread-safe, depending on the implementation of
openlog(),
and
syslog().