freebsd-dev/usr.sbin/i4b/isdnd/process.c
1999-08-28 01:35:59 +00:00

220 lines
5.2 KiB
C

/*
* Copyright (c) 1997, 1999 Hellmuth Michaelis. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*---------------------------------------------------------------------------
*
* i4b daemon - process handling routines
* --------------------------------------
*
* $FreeBSD$
*
* last edit-date: [Sun Feb 14 10:11:54 1999]
*
* -hm debugging processhandling
*
*---------------------------------------------------------------------------*/
#include "isdnd.h"
/*---------------------------------------------------------------------------*
* check if another instance of us is already running
*---------------------------------------------------------------------------*/
void
check_pid(void)
{
FILE *fp;
/* check if another lock-file already exists */
if((fp = fopen(PIDFILE, "r")) != NULL)
{
/* lockfile found, check */
int oldpid;
/* read pid from file */
if((fscanf(fp, "%d", &oldpid)) != 1)
{
log(LL_ERR, "ERROR, reading pid from lockfile failed, terminating!");
exit(1);
}
/* check if process got from file is still alive */
if((kill(oldpid, 0)) != 0)
{
/* process does not exist */
/* close file */
fclose(fp);
DBGL(DL_PROC, (log(LL_DBG, "removing old lock-file %s", PIDFILE)));
/* remove file */
unlink(PIDFILE);
}
else
{
/* process is still alive */
log(LL_ERR, "ERROR, another daemon is already running, pid = %d, terminating!", oldpid);
exit(1);
}
}
}
/*---------------------------------------------------------------------------*
* establish and init process lock file
*---------------------------------------------------------------------------*/
void
write_pid(void)
{
FILE *fp;
/* write my pid into lock-file */
if((fp = fopen(PIDFILE, "w")) == NULL)
{
log(LL_ERR, "ERROR, can't open lockfile for writing, terminating");
do_exit(1);
}
if((fprintf(fp, "%d", (int)getpid())) == EOF)
{
log(LL_ERR, "ERROR, can't write pid to lockfile, terminating");
do_exit(1);
}
fsync(fileno(fp));
fclose(fp);
}
/*---------------------------------------------------------------------------*
* become a daemon
*---------------------------------------------------------------------------*/
void
daemonize(void)
{
int fd;
switch (fork())
{
case -1: /* error */
log(LL_ERR, "ERROR, daemonize/fork: %s", strerror(errno));
exit(1);
case 0: /* child */
break;
default: /* parent */
exit(0);
}
/* new session / no control tty */
if(setsid() == -1)
{
log(LL_ERR, "ERROR, setsid returns: %s", strerror(errno));
exit(1);
}
/* go away from mounted dir */
chdir("/");
/* move i/o to another device ? */
if(do_fullscreen && do_rdev)
{
char *tp;
if((fd = open(rdev, O_RDWR, 0)) != -1)
{
if(!isatty(fd))
{
log(LL_ERR, "ERROR, device %s is not a tty!", rdev);
exit(1);
}
if((dup2(fd, STDIN_FILENO)) == -1)
{
log(LL_ERR, "ERROR, dup2 stdin: %s", strerror(errno));
exit(1);
}
if((dup2(fd, STDOUT_FILENO)) == -1)
{
log(LL_ERR, "ERROR, dup2 stdout: %s", strerror(errno));
exit(1);
}
if((dup2(fd, STDERR_FILENO)) == -1)
{
log(LL_ERR, "ERROR, dup2 stderr: %s", strerror(errno));
exit(1);
}
}
else
{
log(LL_ERR, "ERROR, cannot open redirected device: %s", strerror(errno));
exit(1);
}
if(fd > 2)
{
if((close(fd)) == -1)
{
log(LL_ERR, "ERROR, close in daemonize: %s", strerror(errno));
exit(1);
}
}
/* curses output && fork NEEDS controlling tty */
if((ioctl(STDIN_FILENO, TIOCSCTTY, (char *)NULL)) < 0)
{
log(LL_ERR, "ERROR, cannot setup tty as controlling terminal: %s", strerror(errno));
exit(1);
}
/* in case there is no environment ... */
if(((tp = getenv("TERM")) == NULL) || (*tp == '\0'))
{
if(do_ttytype == 0)
{
log(LL_ERR, "ERROR, no environment variable TERM found and -t not specified!");
exit(1);
}
if((setenv("TERM", ttype, 1)) != 0)
{
log(LL_ERR, "ERROR, setenv TERM=%s failed: %s", ttype, strerror(errno));
exit(1);
}
}
}
}
/* EOF */