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.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[]- 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().
