diff options
author | ache <ache@FreeBSD.org> | 1995-09-14 22:01:06 +0000 |
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committer | ache <ache@FreeBSD.org> | 1995-09-14 22:01:06 +0000 |
commit | 4e31b924ed95cf68cb7fb222c8172bc24f42b0ac (patch) | |
tree | 36da785c758f86bd32972dc012d36b3684c2c9f8 /sbin/startslip/uucplock.c | |
parent | cf5157b53673cd8d8d9e8c066de0f0e00be747f2 (diff) | |
download | FreeBSD-src-4e31b924ed95cf68cb7fb222c8172bc24f42b0ac.zip FreeBSD-src-4e31b924ed95cf68cb7fb222c8172bc24f42b0ac.tar.gz |
All changes still related to original version:
Don't close line twice.
Change typo == to = in assignment.
Don't restart, if ioctl fails.
Implement uucp-style locking to help dialout pgms.
Diffstat (limited to 'sbin/startslip/uucplock.c')
-rw-r--r-- | sbin/startslip/uucplock.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/sbin/startslip/uucplock.c b/sbin/startslip/uucplock.c new file mode 100644 index 0000000..18ce24c --- /dev/null +++ b/sbin/startslip/uucplock.c @@ -0,0 +1,138 @@ +/* + * 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> + +#define _PATH_LOCKDIRNAME "/var/spool/lock/LCK..%s" + +/* Forward declarations */ +static int put_pid (int fd, int pid); +static int get_pid (int fd); + +/* + * uucp style locking routines + * return: 0 - success + * -1 - failure + */ + +uu_lock (char *ttyname) +{ + int fd, pid; + char tbuf[sizeof(_PATH_LOCKDIRNAME) + MAXNAMLEN]; + off_t lseek(); + + (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 (get_pid (fd) == -1) { + (void)close(fd); + syslog(LOG_ERR, "lock read: %m"); + 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) { + (void)close(fd); + syslog(LOG_ERR, "lock lseek: %m"); + return(-1); + } + /* fall out and finish the locking process */ + } + pid = getpid(); + if (!put_pid (fd, pid)) { + (void)close(fd); + (void)unlink(tbuf); + syslog(LOG_ERR, "lock write: %m"); + return(-1); + } + (void)close(fd); + return(0); +} + +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, int pid) +{ + char buf [32]; + int len; + + len = sprintf (buf, "%10ld\n", (long) pid); + return write (fd, buf, len) == len; +} + +static int get_pid (int fd) +{ + int bytes_read, pid; + char buf [32]; + + 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 */ |