sysvinit/src/utmp.c

225 lines
5.5 KiB
C
Raw Normal View History

/*
* utmp.c Routines to read/write the utmp and wtmp files.
* Basically just wrappers around the library routines.
*
* Version: @(#)utmp.c 2.77 09-Jun-1999 miquels@cistron.nl
*
* Copyright (C) 1999 Miquel van Smoorenburg.
*
* This program 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 2 of the License, or
* (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/utsname.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <time.h>
#include <fcntl.h>
#include <string.h>
#include <utmp.h>
#include "init.h"
#include "initreq.h"
#include "paths.h"
#if defined(__GLIBC__)
# if (__GLIBC__ == 2) && (__GLIBC_MINOR__ == 0) && defined(__powerpc__)
# define HAVE_UPDWTMP 0
# else
# define HAVE_UPDWTMP 1
# endif
#else
# define HAVE_UPDWTMP 0
#endif
/*
* Log an event in the wtmp file (reboot, runlevel)
*/
void write_wtmp(
char *user, /* name of user */
char *id, /* inittab ID */
int pid, /* PID of process */
int type, /* TYPE of entry */
char *line) /* Which line is this */
{
int fd;
struct utmp utmp;
struct utsname uname_buf;
struct timeval tv;
/*
* Try to open the wtmp file. Note that we even try
* this if we have updwtmp() so we can see if the
* wtmp file is accessible.
*/
if ((fd = open(WTMP_FILE, O_WRONLY|O_APPEND)) < 0) return;
#ifdef INIT_MAIN
/*
* Note if we are going to write a boot record.
*/
if (type == BOOT_TIME) wrote_wtmp_reboot++;
/*
* See if we need to write a reboot record. The reason that
* we are being so paranoid is that when we first tried to
* write the reboot record, /var was possibly not mounted
* yet. As soon as we can open WTMP we write a delayed boot record.
*/
if (wrote_wtmp_reboot == 0 && type != BOOT_TIME)
write_wtmp("reboot", "~~", 0, BOOT_TIME, "~");
#endif
/*
* Zero the fields and enter new fields.
*/
memset(&utmp, 0, sizeof(utmp));
#if defined(__GLIBC__)
gettimeofday(&tv, NULL);
utmp.ut_tv.tv_sec = tv.tv_sec;
utmp.ut_tv.tv_usec = tv.tv_usec;
#else
time(&utmp.ut_time);
#endif
utmp.ut_pid = pid;
utmp.ut_type = type;
strncpy(utmp.ut_name, user, sizeof(utmp.ut_name));
strncpy(utmp.ut_id , id , sizeof(utmp.ut_id ));
strncpy(utmp.ut_line, line, sizeof(utmp.ut_line));
/* Put the OS version in place of the hostname */
if (uname(&uname_buf) == 0)
strncpy(utmp.ut_host, uname_buf.release, sizeof(utmp.ut_host));
#if HAVE_UPDWTMP
updwtmp(WTMP_FILE, &utmp);
#else
write(fd, (char *)&utmp, sizeof(utmp));
#endif
close(fd);
}
/*
* Write an entry to the UTMP file. For DEAD_PROCESS, put
* the previous ut_line into oldline if oldline != NULL.
*/
static void write_utmp(
char *user, /* name of user */
char *id, /* inittab ID */
int pid, /* PID of process */
int type, /* TYPE of entry */
char *line, /* LINE if used. */
char *oldline) /* Line of old utmp entry. */
{
struct utmp utmp;
struct utmp tmp;
struct utmp *utmptr;
struct timeval tv;
/*
* Can't do much if UTMP_FILE is not present.
*/
if (access(UTMP_FILE, F_OK) < 0)
return;
#ifdef INIT_MAIN
/*
* Note if we are going to write a boot record.
*/
if (type == BOOT_TIME) wrote_utmp_reboot++;
/*
* See if we need to write a reboot record. The reason that
* we are being so paranoid is that when we first tried to
* write the reboot record, /var was possibly not mounted
* yet. As soon as we can open WTMP we write a delayed boot record.
*/
if (wrote_utmp_reboot == 0 && type != BOOT_TIME)
write_utmp("reboot", "~~", 0, BOOT_TIME, "~", NULL);
#endif
/*
* Fill out an utmp struct.
*/
memset(&utmp, 0, sizeof(utmp));
utmp.ut_type = type;
utmp.ut_pid = pid;
strncpy(utmp.ut_id, id, sizeof(utmp.ut_id));
#if defined(__GLIBC__)
gettimeofday(&tv, NULL);
utmp.ut_tv.tv_sec = tv.tv_sec;
utmp.ut_tv.tv_usec = tv.tv_usec;
#else
time(&utmp.ut_time);
#endif
strncpy(utmp.ut_user, user, UT_NAMESIZE);
if (line) strncpy(utmp.ut_line, line, UT_LINESIZE);
/*
* We might need to find the existing entry first, to
* find the tty of the process (for wtmp accounting).
*/
if (type == DEAD_PROCESS) {
/*
* Find existing entry for the tty line.
*/
setutent();
tmp = utmp;
if ((utmptr = getutid(&tmp)) != NULL) {
strncpy(utmp.ut_line, utmptr->ut_line, UT_LINESIZE);
if (oldline)
strncpy(oldline, utmptr->ut_line, UT_LINESIZE);
}
}
/*
* Update existing utmp file.
*/
setutent();
pututline(&utmp);
endutent();
}
/*
* Write a record to both utmp and wtmp.
*/
void write_utmp_wtmp(
char *user, /* name of user */
char *id, /* inittab ID */
int pid, /* PID of process */
int type, /* TYPE of entry */
char *line) /* LINE if used. */
{
char oldline[UT_LINESIZE];
/*
* For backwards compatibility we just return
* if user == NULL (means : clean up utmp file).
*/
if (user == NULL)
return;
oldline[0] = 0;
write_utmp(user, id, pid, type, line, oldline);
write_wtmp(user, id, pid, type, line && line[0] ? line : oldline);
}