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/* This file is part of GNU Rush.
Copyright (C) 2008-2024 Sergey Poznyakoff
GNU Rush is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GNU Rush is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNU Rush. If not, see <http://www.gnu.org/licenses/>. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <sys/types.h>
#include <sys/time.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include "librush.h"
static int utmp_fd = -1;
static enum rushdb_result status = rushdb_result_eof;
static struct rush_utmp utmprec = { -1, 0 };
int
rush_utmp_open(const char *name, int rw)
{
int fd;
fd = open(name, rw ? O_RDWR|O_CREAT : O_RDONLY, rushdb_file_mode);
if (fd == -1)
return -1;
utmp_fd = fd;
return 0;
}
int
rush_utmp_close()
{
int rc = close(utmp_fd);
utmp_fd = -1;
return rc;
}
static enum rushdb_result
rush_utmp_read0(int statmap, int *pstatus, struct rush_wtmp **pwtmp)
{
for (;;) {
ssize_t n = read(utmp_fd, &utmprec, sizeof(utmprec));
if (n == 0)
return rushdb_result_eof;
if (n != sizeof(utmprec))
return rushdb_result_fail;
if (rush_wtmp_seek(utmprec.offset))
return rushdb_result_fail;
if (statmap == 0
|| RUSH_STATUS_MAP_ISSET(statmap, utmprec.status)) {
if (pwtmp && rush_wtmp_read(pwtmp))
return rushdb_result_fail;
break;
}
}
*pstatus = utmprec.status;
return rushdb_result_ok;
}
enum rushdb_result
rush_utmp_read(int statmap, int *pstatus, struct rush_wtmp **pwtmp)
{
return status = rush_utmp_read0(statmap, pstatus, pwtmp);
}
int
rush_utmp_chstatus(int status)
{
if (utmp_fd == -1 || utmprec.status == -1
|| !(status == RUSH_STATUS_AVAIL || status == RUSH_STATUS_INUSE)) {
errno = EINVAL;
return 1;
}
if (lseek(utmp_fd, - sizeof(utmprec), SEEK_CUR) == -1)
return 1;
utmprec.status = status;
if (write(utmp_fd, &utmprec, sizeof(utmprec)) != sizeof(utmprec))
return 1;
return 0;
}
int
rush_utmp_write(struct rush_wtmp *wtmp)
{
int rc;
off_t off;
if (utmp_fd == -1) {
errno = EINVAL;
return 1;
}
off = rush_wtmp_append(wtmp);
if (off == -1)
return 1;
if (status == rushdb_result_ok) {
if (lseek(utmp_fd, - sizeof(utmprec), SEEK_CUR) == -1)
return 1;
}
utmprec.status = RUSH_STATUS_INUSE;
utmprec.offset = off;
rushdb_lock(utmp_fd, sizeof(utmprec), 0, SEEK_CUR, RUSH_LOCK_WRITE);
rc = write(utmp_fd, &utmprec, sizeof(utmprec));
rushdb_unlock(utmp_fd, - sizeof(utmprec), 0, SEEK_CUR);
if (rc != sizeof(utmprec))
return 1;
return 0;
}
void
rush_utmp_lock_all(int type)
{
rushdb_lock(utmp_fd, 0, 0, SEEK_SET, type);
}
void
rush_utmp_unlock_all()
{
rushdb_unlock(utmp_fd, 0, 0, SEEK_SET);
}
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