busybox/networking/udhcp/common.c
2003-06-14 02:57:53 +00:00

151 lines
3.3 KiB
C

/* common.c
*
* Functions to assist in the writing and removing of pidfiles.
*
* Russ Dill <Russ.Dill@asu.edu> Soptember 2001
* Rewrited 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 <sys/socket.h>
#include "common.h"
static int daemonized;
#ifdef CONFIG_FEATURE_UDHCP_SYSLOG
void udhcp_logging(int level, const char *fmt, ...)
{
int e = errno;
va_list p;
va_list p2;
va_start(p, fmt);
__va_copy(p2, p);
if(!daemonized) {
vprintf(fmt, p);
putchar('\n');
errno = e;
}
vsyslog(level, fmt, p2);
va_end(p);
}
void start_log(const char *client_server)
{
openlog(bb_applet_name, 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, ...)
{
int e = errno;
va_list p;
va_start(p, fmt);
if(!daemonized) {
printf("%s, ", syslog_level_msg[level]);
errno = e;
vprintf(fmt, p);
putchar('\n');
}
va_end(p);
}
void start_log(const char *client_server)
{
udhcp_logging(LOG_INFO, "%s (v%s) started", client_server, VERSION);
}
#endif
static const char *saved_pidfile;
static void exit_fun(void)
{
if (saved_pidfile) unlink(saved_pidfile);
}
void background(const char *pidfile)
{
int pid_fd = -1;
if (pidfile) {
pid_fd = open(pidfile, O_CREAT | O_WRONLY, 0644);
if (pid_fd < 0) {
LOG(LOG_ERR, "Unable to open pidfile %s: %m", pidfile);
} else {
lockf(pid_fd, F_LOCK, 0);
if(!saved_pidfile)
atexit(exit_fun); /* set atexit one only */
saved_pidfile = pidfile; /* but may be rewrite */
}
}
while (pid_fd >= 0 && pid_fd < 3) pid_fd = dup(pid_fd); /* don't let daemon close it */
if (daemon(0, 0) == -1) {
perror("fork");
exit(1);
}
daemonized++;
if (pid_fd >= 0) {
FILE *out;
if ((out = fdopen(pid_fd, "w")) != NULL) {
fprintf(out, "%d\n", getpid());
fclose(out);
}
lockf(pid_fd, F_UNLCK, 0);
close(pid_fd);
}
}
/* Signal handler */
int udhcp_signal_pipe[2];
static void signal_handler(int sig)
{
if (send(udhcp_signal_pipe[1], &sig, sizeof(sig), MSG_DONTWAIT) < 0) {
LOG(LOG_ERR, "Could not send signal: %m");
}
}
void udhcp_set_signal_pipe(int sig_add)
{
socketpair(AF_UNIX, SOCK_STREAM, 0, udhcp_signal_pipe);
signal(SIGUSR1, signal_handler);
signal(SIGTERM, signal_handler);
if(sig_add)
signal(sig_add, signal_handler);
}