+++ /dev/null
-/*
- * 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.
- */
-
-#include <sys/cdefs.h>
-
-#ifndef lint
-static const char sccsid[] = "@(#)uucplock.c 8.1 (Berkeley) 6/6/93";
-#endif /* not lint */
-
-#include <sys/types.h>
-#include <sys/file.h>
-#include <dirent.h>
-#include <errno.h>
-#include <paths.h>
-#include <signal.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include "libutil.h"
-
-#define MAXTRIES 5
-
-#define LOCKTMP "LCKTMP..%d"
-#define LOCKFMT "LCK..%s"
-
-#define GORET(level, val) { err = errno; uuerr = (val); \
- goto __CONCAT(ret, level); }
-
-/* Forward declarations */
-static int put_pid (int fd, pid_t pid);
-static pid_t get_pid (int fd,int *err);
-
-/*
- * uucp style locking routines
- */
-
-int
-uu_lock(const char *tty_name)
-{
- int fd, tmpfd, i;
- pid_t pid, pid_old;
- char lckname[sizeof(_PATH_UUCPLOCK) + MAXNAMLEN],
- lcktmpname[sizeof(_PATH_UUCPLOCK) + MAXNAMLEN];
- int err, uuerr;
-
- pid = getpid();
- (void)snprintf(lcktmpname, sizeof(lcktmpname), _PATH_UUCPLOCK LOCKTMP,
- pid);
- (void)snprintf(lckname, sizeof(lckname), _PATH_UUCPLOCK LOCKFMT,
- tty_name);
- if ((tmpfd = creat(lcktmpname, 0664)) < 0)
- GORET(0, UU_LOCK_CREAT_ERR);
-
- for (i = 0; i < MAXTRIES; i++) {
- if (link (lcktmpname, lckname) < 0) {
- if (errno != EEXIST)
- GORET(1, UU_LOCK_LINK_ERR);
- /*
- * file is already locked
- * check to see if the process holding the lock
- * still exists
- */
- if ((fd = open(lckname, O_RDONLY)) < 0)
- GORET(1, UU_LOCK_OPEN_ERR);
-
- if ((pid_old = get_pid (fd, &err)) == -1)
- GORET(2, UU_LOCK_READ_ERR);
-
- close(fd);
-
- if (kill(pid_old, 0) == 0 || errno != ESRCH)
- GORET(1, UU_LOCK_INUSE);
- /*
- * The process that locked the file isn't running, so
- * we'll lock it ourselves
- */
- (void)unlink(lckname);
- } else {
- if (!put_pid (tmpfd, pid))
- GORET(3, UU_LOCK_WRITE_ERR);
- break;
- }
- }
- GORET(1, (i >= MAXTRIES) ? UU_LOCK_TRY_ERR : UU_LOCK_OK);
-
-ret3:
- (void)unlink(lckname);
- goto ret1;
-ret2:
- (void)close(fd);
-ret1:
- (void)close(tmpfd);
- (void)unlink(lcktmpname);
-ret0:
- errno = err;
- return uuerr;
-}
-
-int
-uu_lock_txfr(const char *tty_name, pid_t pid)
-{
- int fd, err;
- char lckname[sizeof(_PATH_UUCPLOCK) + MAXNAMLEN];
-
- snprintf(lckname, sizeof(lckname), _PATH_UUCPLOCK LOCKFMT, tty_name);
-
- if ((fd = open(lckname, O_RDWR)) < 0)
- return UU_LOCK_OWNER_ERR;
- if (get_pid(fd, &err) != getpid())
- err = UU_LOCK_OWNER_ERR;
- else {
- lseek(fd, (off_t)0, SEEK_SET);
- err = put_pid(fd, pid) ? 0 : UU_LOCK_WRITE_ERR;
- }
- close(fd);
-
- return err;
-}
-
-int
-uu_unlock(const char *tty_name)
-{
- char tbuf[sizeof(_PATH_UUCPLOCK) + MAXNAMLEN];
-
- (void)snprintf(tbuf, sizeof(tbuf), _PATH_UUCPLOCK LOCKFMT, tty_name);
- return unlink(tbuf);
-}
-
-const char *
-uu_lockerr(int uu_lockresult)
-{
- static char errbuf[128];
- const char *fmt;
-
- switch (uu_lockresult) {
- case UU_LOCK_INUSE:
- return "device in use";
- case UU_LOCK_OK:
- return "";
- case UU_LOCK_OPEN_ERR:
- fmt = "open error: %s";
- break;
- case UU_LOCK_READ_ERR:
- fmt = "read error: %s";
- break;
- case UU_LOCK_CREAT_ERR:
- fmt = "creat error: %s";
- break;
- case UU_LOCK_WRITE_ERR:
- fmt = "write error: %s";
- break;
- case UU_LOCK_LINK_ERR:
- fmt = "link error: %s";
- break;
- case UU_LOCK_TRY_ERR:
- fmt = "too many tries: %s";
- break;
- case UU_LOCK_OWNER_ERR:
- fmt = "not locking process: %s";
- break;
- default:
- fmt = "undefined error: %s";
- break;
- }
-
- (void)snprintf(errbuf, sizeof(errbuf), fmt, strerror(errno));
- return errbuf;
-}
-
-static int
-put_pid(int fd, pid_t pid)
-{
- char buf[32];
- int len;
-
- len = sprintf (buf, "%10d\n", (int)pid);
- return write (fd, buf, (size_t)len) == len;
-}
-
-static pid_t
-get_pid(int fd, int *err)
-{
- 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 = (pid_t)strtol (buf, (char **) NULL, 10);
- } else {
- pid = -1;
- *err = bytes_read ? errno : EINVAL;
- }
- return pid;
-}
-
-/* end of uucplock.c */
projects / apple / libutil.git / blobdiff