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/* $OpenBSD: locking.c,v 1.15 2020/05/27 03:12:06 millert Exp $ */
/*
* Copyright (c) 1996-1998 Theo de Raadt <deraadt@theos.com>
* Copyright (c) 1996-1998 David Mazieres <dm@lcs.mit.edu>
* 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. The name of the authors may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``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 AUTHORS 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/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <pwd.h>
#include <syslog.h>
#include <unistd.h>
#include <limits.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include "pathnames.h"
#include "mail.local.h"
static char lpath[PATH_MAX];
void
rellock(void)
{
if (lpath[0])
unlink(lpath);
}
int
getlock(const char *name, struct passwd *pw)
{
struct stat sb;
int lfd=-1;
int tries = 0;
(void)snprintf(lpath, sizeof lpath, "%s/%s.lock",
_PATH_MAILDIR, name);
if (stat(_PATH_MAILDIR, &sb) != -1 &&
(sb.st_mode & S_IWOTH) == S_IWOTH) {
mwarn("%s: will not deliver to world-writable spool",
_PATH_MAILDIR);
} else {
/*
* Only root can write the spool directory.
*/
while (1) {
if ((lfd = open(lpath, O_CREAT|O_WRONLY|O_EXCL,
S_IRUSR|S_IWUSR)) != -1)
break;
if (tries > 9) {
mwarn("%s: %s", lpath, strerror(errno));
return(-1);
}
sleep(1U << tries);
tries++;
}
}
return(lfd);
}
void
mwarn(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vsyslog(LOG_ERR, fmt, ap);
va_end(ap);
}
void
merr(int eval, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vsyslog(LOG_ERR, fmt, ap);
va_end(ap);
exit(eval);
}
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