/*
 * Zebra logging funcions.
 * Copyright (C) 1997, 1998, 1999 Kunihiro Ishiguro
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * GNU Zebra is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU Zebra; see the file COPYING.  If not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.  
 */

#ifndef _ZEBRA_LOG_H
#define _ZEBRA_LOG_H

#include <syslog.h>

/* Here is some guidance on logging levels to use:
 *
 * LOG_DEBUG	- For all messages that are enabled by optional debugging
 *		  features, typically preceded by "if (IS...DEBUG...)"
 * LOG_INFO	- Information that may be of interest, but everything seems
 *		  to be working properly.
 * LOG_NOTICE	- Only for message pertaining to daemon startup or shutdown.
 * LOG_WARNING	- Warning conditions: unexpected events, but the daemon believes
 *		  it can continue to operate correctly.
 * LOG_ERR	- Error situations indicating malfunctions.  Probably require
 *		  attention.
 *
 * Note: LOG_CRIT, LOG_ALERT, and LOG_EMERG are currently not used anywhere,
 * please use LOG_ERR instead.
 */

typedef enum 
{
  ZLOG_NONE,
  ZLOG_DEFAULT,
  ZLOG_ZEBRA,
  ZLOG_RIP,
  ZLOG_BGP,
  ZLOG_OSPF,
  ZLOG_RIPNG,
  ZLOG_BABEL,
  ZLOG_OSPF6,
  ZLOG_ISIS,
  ZLOG_MASC
} zlog_proto_t;

/* If maxlvl is set to ZLOG_DISABLED, then no messages will be sent
   to that logging destination. */
#define ZLOG_DISABLED	(LOG_EMERG-1)

typedef enum
{
  ZLOG_DEST_SYSLOG = 0,
  ZLOG_DEST_STDOUT,
  ZLOG_DEST_MONITOR,
  ZLOG_DEST_FILE
} zlog_dest_t;
#define ZLOG_NUM_DESTS		(ZLOG_DEST_FILE+1)

struct zlog 
{
  const char *ident;	/* daemon name (first arg to openlog) */
  zlog_proto_t protocol;
  int maxlvl[ZLOG_NUM_DESTS];	/* maximum priority to send to associated
  				   logging destination */
  int default_lvl;	/* maxlvl to use if none is specified */
  FILE *fp;
  char *filename;
  int facility;		/* as per syslog facility */
  int record_priority;	/* should messages logged through stdio include the
  			   priority of the message? */
  int syslog_options;	/* 2nd arg to openlog */
  int timestamp_precision;	/* # of digits of subsecond precision */
};

/* Message structure. */
struct message
{
  int key;
  const char *str;
};

/* Default logging strucutre. */
extern struct zlog *zlog_default;

/* Open zlog function */
extern struct zlog *openzlog (const char *progname, zlog_proto_t protocol,
		              int syslog_options, int syslog_facility);

/* Close zlog function. */
extern void closezlog (struct zlog *zl);

/* GCC have printf type attribute check.  */
#ifdef __GNUC__
#define PRINTF_ATTRIBUTE(a,b) __attribute__ ((__format__ (__printf__, a, b)))
#else
#define PRINTF_ATTRIBUTE(a,b)
#endif /* __GNUC__ */

/* Generic function for zlog. */
extern void zlog (struct zlog *zl, int priority, const char *format, ...)
  PRINTF_ATTRIBUTE(3, 4);

/* Handy zlog functions. */
extern void zlog_err (const char *format, ...) PRINTF_ATTRIBUTE(1, 2);
extern void zlog_warn (const char *format, ...) PRINTF_ATTRIBUTE(1, 2);
extern void zlog_info (const char *format, ...) PRINTF_ATTRIBUTE(1, 2);
extern void zlog_notice (const char *format, ...) PRINTF_ATTRIBUTE(1, 2);
extern void zlog_debug (const char *format, ...) PRINTF_ATTRIBUTE(1, 2);

/* For bgpd's peer oriented log. */
extern void plog_err (struct zlog *, const char *format, ...)
  PRINTF_ATTRIBUTE(2, 3);
extern void plog_warn (struct zlog *, const char *format, ...)
  PRINTF_ATTRIBUTE(2, 3);
extern void plog_info (struct zlog *, const char *format, ...)
  PRINTF_ATTRIBUTE(2, 3);
extern void plog_notice (struct zlog *, const char *format, ...)
  PRINTF_ATTRIBUTE(2, 3);
extern void plog_debug (struct zlog *, const char *format, ...)
  PRINTF_ATTRIBUTE(2, 3);

/* Set logging level for the given destination.  If the log_level
   argument is ZLOG_DISABLED, then the destination is disabled.
   This function should not be used for file logging (use zlog_set_file
   or zlog_reset_file instead). */
extern void zlog_set_level (struct zlog *zl, zlog_dest_t, int log_level);

/* Set logging to the given filename at the specified level. */
extern int zlog_set_file (struct zlog *zl, const char *filename, int log_level);
/* Disable file logging. */
extern int zlog_reset_file (struct zlog *zl);

/* Rotate log. */
extern int zlog_rotate (struct zlog *);

/* For hackey message lookup and check */
#define LOOKUP_DEF(x, y, def) mes_lookup(x, x ## _max, y, def, #x)
#define LOOKUP(x, y) LOOKUP_DEF(x, y, "(no item found)")

extern const char *lookup (const struct message *, int);
extern const char *mes_lookup (const struct message *meslist, 
                               int max, int index,
                               const char *no_item, const char *mesname);

extern const char *zlog_priority[];
extern const char *zlog_proto_names[];

/* Safe version of strerror -- never returns NULL. */
extern const char *safe_strerror(int errnum);

/* To be called when a fatal signal is caught. */
extern void zlog_signal(int signo, const char *action
#ifdef SA_SIGINFO
			, siginfo_t *siginfo, void *program_counter
#endif
		       );

/* Log a backtrace. */
extern void zlog_backtrace(int priority);

/* Log a backtrace, but in an async-signal-safe way.  Should not be
   called unless the program is about to exit or abort, since it messes
   up the state of zlog file pointers.  If program_counter is non-NULL,
   that is logged in addition to the current backtrace. */
extern void zlog_backtrace_sigsafe(int priority, void *program_counter);

/* Puts a current timestamp in buf and returns the number of characters
   written (not including the terminating NUL).  The purpose of
   this function is to avoid calls to localtime appearing all over the code.
   It caches the most recent localtime result and can therefore
   avoid multiple calls within the same second.  If buflen is too small,
   *buf will be set to '\0', and 0 will be returned. */
extern size_t quagga_timestamp(int timestamp_precision /* # subsecond digits */,
			       char *buf, size_t buflen);

/* structure useful for avoiding repeated rendering of the same timestamp */
struct timestamp_control {
   size_t len;		/* length of rendered timestamp */
   int precision;	/* configuration parameter */
   int already_rendered; /* should be initialized to 0 */
   char buf[40];	/* will contain the rendered timestamp */
};

/* Defines for use in command construction: */

#define LOG_LEVELS "(emergencies|alerts|critical|errors|warnings|notifications|informational|debugging)"

#define LOG_LEVEL_DESC \
  "System is unusable\n" \
  "Immediate action needed\n" \
  "Critical conditions\n" \
  "Error conditions\n" \
  "Warning conditions\n" \
  "Normal but significant conditions\n" \
  "Informational messages\n" \
  "Debugging messages\n"

#define LOG_FACILITIES "(kern|user|mail|daemon|auth|syslog|lpr|news|uucp|cron|local0|local1|local2|local3|local4|local5|local6|local7)"

#define LOG_FACILITY_DESC \
       "Kernel\n" \
       "User process\n" \
       "Mail system\n" \
       "System daemons\n" \
       "Authorization system\n" \
       "Syslog itself\n" \
       "Line printer system\n" \
       "USENET news\n" \
       "Unix-to-Unix copy system\n" \
       "Cron/at facility\n" \
       "Local use\n" \
       "Local use\n" \
       "Local use\n" \
       "Local use\n" \
       "Local use\n" \
       "Local use\n" \
       "Local use\n" \
       "Local use\n"

#endif /* _ZEBRA_LOG_H */