busybox/networking/udhcp/common.c

91 lines
1.8 KiB
C

/* vi: set sw=4 ts=4: */
/* 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
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#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 <syslog.h>
#include "common.h"
#include "pidfile.h"
static int daemonized;
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 fd = open(bb_dev_null, O_RDWR, 0);
if (fd < 0)
return;
while (fd < 3)
fd = dup(fd);
close(fd);
}
void udhcp_background(const char *pidfile)
{
#ifdef __uClinux__
bb_error_msg("cannot background in uclinux (yet)");
#else /* __uClinux__ */
int pid_fd;
/* hold lock during fork. */
pid_fd = pidfile_acquire(pidfile);
setsid();
xdaemon(0, 0);
daemonized++;
logmode &= ~LOGMODE_STDIO;
pidfile_write_release(pid_fd);
#endif /* __uClinux__ */
}
void udhcp_start_log_and_pid(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);
if (ENABLE_FEATURE_UDHCP_SYSLOG) {
openlog(applet_name, LOG_PID, LOG_LOCAL0);
logmode |= LOGMODE_SYSLOG;
}
bb_info_msg("%s (v%s) started", applet_name, BB_VER);
}