/* common.c
 *
 * Functions for debugging and logging as well as some other
 * simple helper functions.
 *
 * Russ Dill <Russ.Dill@asu.edu> 2001-2003
 * Rewritten by Vladimir Oleynik <dzo@simtreas.ru> (C) 2003
 *
 * This program 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 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <signal.h>
#include <paths.h>
#include <sys/socket.h>
#include <stdarg.h>

#include "common.h"
#include "pidfile.h"


static int daemonized = 0;

long uptime(void)
{
  struct sysinfo info;
  sysinfo(&info);
  return info.uptime;
}


/*
 * This function makes sure our first socket calls
 * aren't going to fd 1 (printf badness...) and are
 * not later closed by daemon()
 */
static inline void sanitize_fds(void)
{
  int zero;
  if ((zero = open(_PATH_DEVNULL, O_RDWR, 0)) < 0) return;
  while (zero < 3) zero = dup(zero);
  close(zero);
}

void background(const char *pidfile)
{
  int pid_fd;

  /* hold lock during fork. */
  pid_fd = pidfile_acquire(pidfile);
#ifdef HAVE_MMU
  if (daemon(0, 0) == -1) {
    perror("fork");
    exit(1);
  }
#endif
  daemonized++;
  pidfile_write_release(pid_fd);
}


#ifdef UDHCP_SYSLOG
void udhcp_logging(int level, const char *fmt, ...)
{
  va_list p;
  va_list p2;

  va_start(p, fmt);
  __va_copy(p2, p);
  if(!daemonized) {
    vprintf(fmt, p);
    putchar('\n');
  }
  vsyslog(level, fmt, p2);
  va_end(p);
}


void start_log_and_pid(const char *client_server, const char *pidfile)
{
  int pid_fd;

  /* Make sure our syslog fd isn't overwritten */
  sanitize_fds();

  /* do some other misc startup stuff while we are here to save bytes */
  pid_fd = pidfile_acquire(pidfile);
  pidfile_write_release(pid_fd);

  /* equivelent of doing a fflush after every \n */
  setlinebuf(stdout);

  openlog(client_server, LOG_PID | LOG_CONS, LOG_LOCAL0);
  udhcp_logging(LOG_INFO, "%s (v%s) started", client_server, VERSION);
}


#else


static char *syslog_level_msg[] = {
  [LOG_EMERG]   = "EMERGENCY!",
  [LOG_ALERT]   = "ALERT!",
  [LOG_CRIT]    = "critical!",
  [LOG_WARNING] = "warning",
  [LOG_ERR]     = "error",
  [LOG_INFO]    = "info",
  [LOG_DEBUG]   = "debug"
};


void udhcp_logging(int level, const char *fmt, ...)
{
  va_list p;

  va_start(p, fmt);
  if(!daemonized) {
    printf("%s, ", syslog_level_msg[level]);
    vprintf(fmt, p);
    putchar('\n');
  }
  va_end(p);
}


void start_log_and_pid(const char *client_server, const char *pidfile)
{
  char *pid_file=NULL;

  pid_file = (char *)pidfile;
  /* Make sure our syslog fd isn't overwritten */
  sanitize_fds();

  /* do some other misc startup stuff while we are here to save bytes */
  // Modified by James Chen, Foxconn, 2010/08/30
  // Avoid to run two instances
  //pid_fd = pidfile_acquire(pidfile);
  //pidfile_write_release(pid_fd);
  if (!check_pid(pid_file))
  {
    if (!write_pid(pid_file))
    {
      fputs("Can't write pid.\n", stderr);
      exit(1); /* exit during startup - questionable */
    }
  }
  else
  {
    fputs(" Already running.\n", stderr);
    exit(1); /* "good" exit, done if udhcp is already running */
  }
  // End of Modified by James Chen, Foxconn, 2010/08/30

  /* equivelent of doing a fflush after every \n */
  setlinebuf(stdout);

  udhcp_logging(LOG_INFO, "%s (v%s) started", client_server, VERSION);
}
#endif

