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Implement uucp-locking

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Cleanup debug/syslog code
This commit is contained in:
Andrey A. Chernov 1995-09-19 03:27:31 +00:00
parent a3adc4f8c5
commit 5ab506f0f1
3 changed files with 172 additions and 10 deletions
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3
sbin/slattach/Makefile
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@ -1,8 +1,9 @@
# @(#)Makefile 5.4 (Berkeley) 5/11/90
#
# $Header: /a/cvs/386BSD/src/sbin/slattach/Makefile,v 1.5 1993/08/29 18:11:14 rgrimes Exp $
# $Header: /home/ncvs/src/sbin/slattach/Makefile,v 1.4 1994/08/23 08:28:30 rich Exp $
PROG= slattach
SRCS= slattach.c uucplock.c
MAN8= slattach.8
MLINKS= slattach.8 slip.8
LDADD= -lutil

36
sbin/slattach/slattach.c
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@ -77,6 +77,8 @@ void acquire_line(); /* get tty device as controling terminal */
int fd = -1;
char *dev = (char *)0; /* path name of the tty (e.g. /dev/tty01) */
char *dvname; /* basename of dev */
int locked = 0; /* uucp lock */
int flow_control = 0; /* non-zero to enable hardware flow control. */
int modem_control = HUPCL; /* !CLOCAL+HUPCL iff we watch carrier. */
int comstate; /* TIOCMGET current state of serial driver */
@ -122,7 +124,6 @@ int main(int argc, char **argv)
int option;
extern char *optarg;
extern int optind;
char *cp;
while ((option = getopt(argc, argv, "ace:fhlnr:s:u:zK:O:S:")) != EOF) {
switch (option) {
@ -199,9 +200,9 @@ int main(int argc, char **argv)
strncat(tty_path, dev, 10);
dev = tty_path;
}
cp = strrchr(dev, '/'); /* always succeeds */
cp++; /* trailing tty pathname component */
sprintf(pidfilename, "%sslattach.%s.pid", _PATH_VARRUN, cp);
dvname = strrchr(dev, '/'); /* always succeeds */
dvname++; /* trailing tty pathname component */
sprintf(pidfilename, "%sslattach.%s.pid", _PATH_VARRUN, dvname);
printf("%s\n",pidfilename);
if (!foreground)
@ -251,7 +252,10 @@ void acquire_line()
int ttydisc = TTYDISC;
FILE *pidfile;
ioctl(fd, TIOCSETD, &ttydisc); /* reset to tty discipline */
if (ioctl(fd, TIOCSETD, &ttydisc) < 0) { /* reset to tty discipline */
syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
exit_handler(1);
}
(void)close(STDIN_FILENO); /* close FDs before forking. */
(void)close(STDOUT_FILENO);
@ -260,7 +264,10 @@ void acquire_line()
(void)close(fd);
signal(SIGHUP, SIG_IGN); /* ignore HUP signal when parent dies. */
daemon(0,0); /* fork, setsid, chdir /, and close std*. */
if (daemon(0,0)) { /* fork, setsid, chdir /, and close std*. */
syslog(LOG_ERR, "daemon(0,0): %m");
exit_handler(1);
}
while (getppid () != 1)
sleep (1); /* Wait for parent to die. */
@ -274,8 +281,15 @@ void acquire_line()
if ((int)signal(SIGHUP,sighup_handler) < 0) /* Re-enable HUP signal */
syslog(LOG_NOTICE,"cannot install SIGHUP handler: %m");
/* unlock not needed here, always re-lock with new pid */
if (uu_lock(dvname)) {
syslog(LOG_ERR, "can't lock %s", dev);
exit_handler(1);
}
locked = 1;
if ((fd = open(dev, O_RDWR | O_NONBLOCK, 0)) < 0) {
syslog(LOG_ERR, "open(%s) fd=%d: %m", dev, fd);
syslog(LOG_ERR, "open(%s) %m", dev);
exit_handler(1);
}
(void)dup2(fd, STDIN_FILENO);
@ -286,8 +300,10 @@ void acquire_line()
fd = STDIN_FILENO;
/* acquire the serial line as a controling terminal. */
if (ioctl(fd, TIOCSCTTY, 0) < 0)
syslog(LOG_NOTICE,"ioctl(TIOCSCTTY) failed: %m");
if (ioctl(fd, TIOCSCTTY, 0) < 0) {
syslog(LOG_ERR,"ioctl(TIOCSCTTY): %m");
exit_handler(1);
}
/* Make us the foreground process group associated with the
slip line which is our controlling terminal. */
if (tcsetpgrp(fd, getpid()) < 0)
@ -514,6 +530,8 @@ void exit_handler(int ret)
*/
if (fd != -1)
close(fd);
if (locked)
uu_unlock(dvname);
/* Remove the PID file */
(void)unlink(pidfilename);

143
sbin/slattach/uucplock.c Normal file
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@ -0,0 +1,143 @@
/*
* Copyright (c) 1988, 1993
* The Regents of the University of California. 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*/
#ifndef lint
static char sccsid[] = "@(#)uucplock.c 8.1 (Berkeley) 6/6/93";
#endif /* not lint */
#include <sys/types.h>
#include <sys/file.h>
#include <sys/dir.h>
#include <errno.h>
#include <syslog.h>
#include <unistd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#define _PATH_LOCKDIRNAME "/var/spool/lock/LCK..%s"
/* Forward declarations */
static int put_pid (int fd, pid_t pid);
static pid_t get_pid (int fd);
/*
* uucp style locking routines
* return: 0 - success
* -1 - failure
*/
int uu_lock (char *ttyname)
{
int fd;
pid_t pid;
char tbuf[sizeof(_PATH_LOCKDIRNAME) + MAXNAMLEN];
(void)sprintf(tbuf, _PATH_LOCKDIRNAME, ttyname);
fd = open(tbuf, O_RDWR|O_CREAT|O_EXCL, 0660);
if (fd < 0) {
/*
* file is already locked
* check to see if the process holding the lock still exists
*/
fd = open(tbuf, O_RDWR, 0);
if (fd < 0) {
syslog(LOG_ERR, "lock open: %m");
return(-1);
}
if ((pid = get_pid (fd)) == -1) {
syslog(LOG_ERR, "lock read: %m");
(void)close(fd);
return(-1);
}
if (kill(pid, 0) == 0 || errno != ESRCH) {
(void)close(fd); /* process is still running */
return(-1);
}
/*
* The process that locked the file isn't running, so
* we'll lock it ourselves
*/
if (lseek(fd, 0L, L_SET) < 0) {
syslog(LOG_ERR, "lock lseek: %m");
(void)close(fd);
return(-1);
}
/* fall out and finish the locking process */
}
pid = getpid();
if (!put_pid (fd, pid)) {
syslog(LOG_ERR, "lock write: %m");
(void)close(fd);
(void)unlink(tbuf);
return(-1);
}
(void)close(fd);
return(0);
}
int uu_unlock (char *ttyname)
{
char tbuf[sizeof(_PATH_LOCKDIRNAME) + MAXNAMLEN];
(void)sprintf(tbuf, _PATH_LOCKDIRNAME, ttyname);
return(unlink(tbuf));
}
static int put_pid (int fd, pid_t pid)
{
char buf [32];
int len;
len = sprintf (buf, "%10ld\n", pid);
return write (fd, buf, len) == len;
}
static pid_t get_pid (int fd)
{
int bytes_read;
char buf [32];
pid_t pid;
bytes_read = read (fd, buf, sizeof (buf) - 1);
if (bytes_read > 0) {
buf [bytes_read] = '\0';
pid = strtol (buf, (char **) NULL, 10);
}
else
pid = -1;
return pid;
}
/* end of uucplock.c */