/* Logging of zebra
 * 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.  
 */

#include <zebra.h>

#include "log.h"
#include "memory.h"
#include "command.h"

struct zlog *zlog_default = NULL;

const char *zlog_proto_names[] = 
{
  "NONE",
  "DEFAULT",
  "ZEBRA",
  "RIP",
  "BGP",
  "OSPF",
  "RIPNG",
  "OSPF6",
  "ISIS",
  "MASC",
  NULL,
};

const char *zlog_priority[] =
{
  "emergencies",
  "alerts",
  "critical",
  "errors",
  "warnings",
  "notifications",
  "informational",
  "debugging",
  NULL,
};
  


/* For time string format. */
#define TIME_BUF 27

/* Utility routine for current time printing. */
static void
time_print (FILE *fp)
{
  int ret;
  char buf [TIME_BUF];
  time_t clock;
  struct tm *tm;
  
  time (&clock);
  tm = localtime (&clock);

  ret = strftime (buf, TIME_BUF, "%Y/%m/%d %H:%M:%S", tm);
  if (ret == 0) {
    zlog_warn ("strftime error");
  }

  fprintf (fp, "%s ", buf);
}

/* va_list version of zlog. */
static void
vzlog (struct zlog *zl, int priority, const char *format, va_list args)
{
  /* If zlog is not specified, use default one. */
  if (zl == NULL)
    zl = zlog_default;

  /* When zlog_default is also NULL, use stderr for logging. */
  if (zl == NULL)
    {
      time_print (stderr);
      fprintf (stderr, "%s: ", "unknown");
      vfprintf (stderr, format, args);
      fprintf (stderr, "\n");
      fflush (stderr);

      /* In this case we return at here. */
      return;
    }

  /* only log this information if it has not been masked out */
  if ( priority > zl->maskpri )
    return ;
		
  /* Syslog output */
  if (zl->flags & ZLOG_SYSLOG)
    {
      va_list ac;
      va_copy(ac, args);
      vsyslog (priority|zlog_default->facility, format, ac);
      va_end(ac);
    }

  /* File output. */
  if (zl->flags & ZLOG_FILE)
    {
      va_list ac;
      time_print (zl->fp);
      if (zl->record_priority)
	fprintf (zl->fp, "%s: ", zlog_priority[priority]);
      fprintf (zl->fp, "%s: ", zlog_proto_names[zl->protocol]);
      va_copy(ac, args);
      vfprintf (zl->fp, format, ac);
      va_end(ac);
      fprintf (zl->fp, "\n");
      fflush (zl->fp);
    }

  /* stdout output. */
  if (zl->flags & ZLOG_STDOUT)
    {
      va_list ac;
      time_print (stdout);
      if (zl->record_priority)
	fprintf (stdout, "%s: ", zlog_priority[priority]);
      fprintf (stdout, "%s: ", zlog_proto_names[zl->protocol]);
      va_copy(ac, args);
      vfprintf (stdout, format, ac);
      va_end(ac);
      fprintf (stdout, "\n");
      fflush (stdout);
    }

  /* stderr output. */
  if (zl->flags & ZLOG_STDERR)
    {
      va_list ac;
      time_print (stderr);
      if (zl->record_priority)
	fprintf (stderr, "%s: ", zlog_priority[priority]);
      fprintf (stderr, "%s: ", zlog_proto_names[zl->protocol]);
      va_copy(ac, args);
      vfprintf (stderr, format, ac);
      va_end(ac);
      fprintf (stderr, "\n");
      fflush (stderr);
    }

  /* Terminal monitor. */
  vty_log (zlog_proto_names[zl->protocol], format, args);
}

static char *
str_append(char *dst, int len, const char *src)
{
  while ((len-- > 0) && *src)
    *dst++ = *src++;
  return dst;
}

static char *
num_append(char *s, int len, u_long x)
{
  char buf[30];
  char *t = &buf[29];

  *t = '\0';
  while (x && (t > buf))
    {
      *--t = '0'+(x % 10);
      x /= 10;
    }
  return str_append(s,len,t);
}

/* Note: the goal here is to use only async-signal-safe functions.
   Needs to be enhanced to support syslog logging. */
void
zlog_signal(int signo, const char *action)
{
  time_t now;
  char buf[sizeof("DEFAULT: Received signal S at T; aborting...")+60];
  char *s = buf;
#define LOC s,buf+sizeof(buf)-s

  time(&now);
  if (zlog_default)
    {
      s = str_append(LOC,zlog_proto_names[zlog_default->protocol]);
      *s++ = ':';
      *s++ = ' ';
    }
  s = str_append(LOC,"Received signal ");
  s = num_append(LOC,signo);
  s = str_append(LOC," at ");
  s = num_append(LOC,now);
  s = str_append(LOC,"; ");
  s = str_append(LOC,action);
  *s++ = '\n';

#define DUMP(FP) write(fileno(FP),buf,s-buf);
  if (!zlog_default)
    DUMP(stderr)
  else
    {
      if ((zlog_default->flags & ZLOG_FILE) && zlog_default->fp)
        DUMP(zlog_default->fp)
      if (zlog_default->flags & ZLOG_STDOUT)
        DUMP(stdout)
      if (zlog_default->flags & ZLOG_STDERR)
        DUMP(stderr)
      /* Is there a signal-safe way to send a syslog message? */
    }
#undef DUMP

  zlog_backtrace_sigsafe(LOG_ERR);
#undef LOC
}

/* Log a backtrace using only async-signal-safe functions.
   Needs to be enhanced to support syslog logging. */
void
zlog_backtrace_sigsafe(int priority)
{
#ifdef HAVE_GLIBC_BACKTRACE
  void *array[20];
  int size;
  char buf[100];
  char *s;
#define LOC s,buf+sizeof(buf)-s

  /* only log this information if it has not been masked out */
  if (zlog_default && (priority > zlog_default->maskpri))
    return;

  if (((size = backtrace(array,sizeof(array)/sizeof(array[0]))) <= 0) ||
      ((size_t)size > sizeof(array)/sizeof(array[0])))
    return;
  s = buf;
  s = str_append(LOC,"Backtrace for ");
  s = num_append(LOC,size);
  s = str_append(LOC," stack frames:\n");

#define DUMP(FP) { \
  write(fileno(FP),buf,s-buf);	\
  backtrace_symbols_fd(array, size, fileno(FP)); \
}

  if (!zlog_default)
    DUMP(stderr)
  else
    {
      if ((zlog_default->flags & ZLOG_FILE) && zlog_default->fp)
	DUMP(zlog_default->fp)
      if (zlog_default->flags & ZLOG_STDOUT)
	DUMP(stdout)
      if (zlog_default->flags & ZLOG_STDERR)
	DUMP(stderr)
      /* Is there a signal-safe way to send a syslog message? */
    }
#undef DUMP
#undef LOC
#endif /* HAVE_GLIBC_BACKTRACE */
}

void
zlog_backtrace(int priority)
{
#ifndef HAVE_GLIBC_BACKTRACE
  zlog(NULL, priority, "No backtrace available on this platform.");
#else
  void *array[20];
  int size, i;
  char **strings;

  if (((size = backtrace(array,sizeof(array)/sizeof(array[0]))) <= 0) ||
      ((size_t)size > sizeof(array)/sizeof(array[0])))
    {
      zlog_err("Cannot get backtrace, returned invalid # of frames %d "
	       "(valid range is between 1 and %u)",
	       size, sizeof(array)/sizeof(array[0]));
      return;
    }
  zlog(NULL, priority, "Backtrace for %d stack frames:", size);
  if (!(strings = backtrace_symbols(array, size)))
    {
      zlog_err("Cannot get backtrace symbols (out of memory?)");
      for (i = 0; i < size; i++)
	zlog(NULL, priority, "[bt %d] %p",i,array[i]);
    }
  else
    {
      for (i = 0; i < size; i++)
	zlog(NULL, priority, "[bt %d] %s",i,strings[i]);
      free(strings);
    }
#endif /* HAVE_GLIBC_BACKTRACE */
}

void
zlog (struct zlog *zl, int priority, const char *format, ...)
{
  va_list args;

  va_start(args, format);
  vzlog (zl, priority, format, args);
  va_end (args);
}

#define ZLOG_FUNC(FUNCNAME,PRIORITY) \
void \
FUNCNAME(const char *format, ...) \
{ \
  va_list args; \
  va_start(args, format); \
  vzlog (NULL, PRIORITY, format, args); \
  va_end(args); \
}

ZLOG_FUNC(zlog_err, LOG_ERR)

ZLOG_FUNC(zlog_warn, LOG_WARNING)

ZLOG_FUNC(zlog_info, LOG_INFO)

ZLOG_FUNC(zlog_notice, LOG_NOTICE)

ZLOG_FUNC(zlog_debug, LOG_DEBUG)

#undef ZLOG_FUNC

#define PLOG_FUNC(FUNCNAME,PRIORITY) \
void \
FUNCNAME(struct zlog *zl, const char *format, ...) \
{ \
  va_list args; \
  va_start(args, format); \
  vzlog (zl, PRIORITY, format, args); \
  va_end(args); \
}

PLOG_FUNC(plog_err, LOG_ERR)

PLOG_FUNC(plog_warn, LOG_WARNING)

PLOG_FUNC(plog_info, LOG_INFO)

PLOG_FUNC(plog_notice, LOG_NOTICE)

PLOG_FUNC(plog_debug, LOG_DEBUG)

#undef PLOG_FUNC

void
_zlog_assert_failed (const char *assertion, const char *file,
		     unsigned int line, const char *function)
{
  zlog_err("Assertion `%s' failed in file %s, line %u, function %s",
	   assertion,file,line,(function ? function : "?"));
  zlog_backtrace(LOG_ERR);
  abort();
}


/* Open log stream */
struct zlog *
openzlog (const char *progname, int flags, zlog_proto_t protocol,
	  int syslog_flags, int syslog_facility)
{
  struct zlog *zl;

  zl = XMALLOC(MTYPE_ZLOG, sizeof (struct zlog));
  memset (zl, 0, sizeof (struct zlog));

  zl->ident = progname;
  zl->flags = flags;
  zl->protocol = protocol;
  zl->facility = syslog_facility;
  zl->maskpri = LOG_DEBUG;
  zl->record_priority = 0;

  openlog (progname, syslog_flags, zl->facility);
  
  return zl;
}

void
closezlog (struct zlog *zl)
{
  closelog();
  fclose (zl->fp);

  XFREE (MTYPE_ZLOG, zl);
}

/* Called from command.c. */
void
zlog_set_flag (struct zlog *zl, int flags)
{
  if (zl == NULL)
    zl = zlog_default;

  zl->flags |= flags;
}

void
zlog_reset_flag (struct zlog *zl, int flags)
{
  if (zl == NULL)
    zl = zlog_default;

  zl->flags &= ~flags;
}

int
zlog_set_file (struct zlog *zl, const char *filename)
{
  FILE *fp;
  mode_t oldumask;

  /* There is opend file.  */
  zlog_reset_file (zl);

  /* Set default zl. */
  if (zl == NULL)
    zl = zlog_default;

  /* Open file. */
  oldumask = umask (0777 & ~LOGFILE_MASK);
  fp = fopen (filename, "a");
  if (fp == NULL)
    {
      umask(oldumask);
      return 0;
    }
  umask(oldumask);

  /* Set flags. */
  zl->filename = strdup (filename);
  zl->flags |= ZLOG_FILE;
  zl->fp = fp;

  return 1;
}

/* Reset opend file. */
int
zlog_reset_file (struct zlog *zl)
{
  if (zl == NULL)
    zl = zlog_default;

  zl->flags &= ~ZLOG_FILE;

  if (zl->fp)
    fclose (zl->fp);
  zl->fp = NULL;

  if (zl->filename)
    free (zl->filename);
  zl->filename = NULL;

  return 1;
}

/* Reopen log file. */
int
zlog_rotate (struct zlog *zl)
{
  FILE *fp;

  if (zl == NULL)
    zl = zlog_default;

  if (zl->fp)
    fclose (zl->fp);
  zl->fp = NULL;

  if (zl->filename)
    {
      mode_t oldumask;

      oldumask = umask (0777 & ~LOGFILE_MASK);
      fp = fopen (zl->filename, "a");
      if (fp == NULL)
        {
	  umask(oldumask);
	  return -1;
        }	
      umask(oldumask);
      zl->fp = fp;
    }

  return 1;
}

/* Message lookup function. */
const char *
lookup (struct message *mes, int key)
{
  struct message *pnt;

  for (pnt = mes; pnt->key != 0; pnt++) 
    if (pnt->key == key) 
      return pnt->str;

  return "";
}

/* Very old hacky version of message lookup function.  Still partly
   used in bgpd and ospfd. FIXME Seems that it's not used any more. */
const char *
mes_lookup (struct message *meslist, int max, int index)
{
  if (index < 0 || index >= max) 
    {
      zlog_err ("message index out of bound: %d", max);
      return NULL;
    }
  return meslist[index].str;
}

/* Wrapper around strerror to handle case where it returns NULL. */
const char *
safe_strerror(int errnum)
{
  const char *s = strerror(errnum);
  return (s != NULL) ? s : "Unknown error";
}