shadow/libmisc/utmp.c

479 lines
11 KiB
C

/*
* Copyright 1989 - 1994, Julianne Frances Haugh
* 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. Neither the name of Julianne F. Haugh 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 JULIE HAUGH 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 JULIE HAUGH 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 <config.h>
#include "defines.h"
#include <utmp.h>
#if HAVE_UTMPX_H
#include <utmpx.h>
#endif
#include <fcntl.h>
#include <stdio.h>
#include "rcsid.h"
RCSID("$Id: utmp.c,v 1.8 1999/06/07 16:40:44 marekm Exp $")
#if HAVE_UTMPX_H
extern struct utmpx utxent;
#endif
extern struct utmp utent;
extern struct utmp *getutent();
extern struct utmp *getutline();
extern void setutent();
extern void endutent();
extern time_t time();
extern char *ttyname();
extern long lseek();
#define NO_UTENT \
"No utmp entry. You must exec \"login\" from the lowest level \"sh\""
#define NO_TTY \
"Unable to determine your tty name."
/*
* checkutmp - see if utmp file is correct for this process
*
* System V is very picky about the contents of the utmp file
* and requires that a slot for the current process exist.
* The utmp file is scanned for an entry with the same process
* ID. If no entry exists the process exits with a message.
*
* The "picky" flag is for network and other logins that may
* use special flags. It allows the pid checks to be overridden.
* This means that getty should never invoke login with any
* command line flags.
*/
#if defined(__linux__) /* XXX */
void
checkutmp(int picky)
{
char *line;
struct utmp *ut;
pid_t pid = getpid();
setutent();
/* First, try to find a valid utmp entry for this process. */
while ((ut = getutent()))
if (ut->ut_pid == pid && ut->ut_line[0] && ut->ut_id[0] &&
(ut->ut_type==LOGIN_PROCESS || ut->ut_type==USER_PROCESS))
break;
/* If there is one, just use it, otherwise create a new one. */
if (ut) {
utent = *ut;
} else {
if (picky) {
puts(NO_UTENT);
exit(1);
}
line = ttyname(0);
if (!line) {
puts(NO_TTY);
exit(1);
}
if (strncmp(line, "/dev/", 5) == 0)
line += 5;
memset((void *) &utent, 0, sizeof utent);
utent.ut_type = LOGIN_PROCESS;
utent.ut_pid = pid;
strncpy(utent.ut_line, line, sizeof utent.ut_line);
/* XXX - assumes /dev/tty?? */
strncpy(utent.ut_id, utent.ut_line + 3, sizeof utent.ut_id);
strcpy(utent.ut_user, "LOGIN");
time(&utent.ut_time);
}
}
#elif defined(LOGIN_PROCESS)
void
checkutmp(int picky)
{
char *line;
struct utmp *ut;
#if HAVE_UTMPX_H
struct utmpx *utx;
#endif
pid_t pid = getpid();
#if HAVE_UTMPX_H
setutxent();
#endif
setutent();
if (picky) {
#if HAVE_UTMPX_H
while ((utx = getutxent()))
if (utx->ut_pid == pid)
break;
if (utx)
utxent = *utx;
#endif
while ((ut = getutent()))
if (ut->ut_pid == pid)
break;
if (ut)
utent = *ut;
#if HAVE_UTMPX_H
endutxent();
#endif
endutent();
if (!ut) {
puts(NO_UTENT);
exit(1);
}
#ifndef UNIXPC
/*
* If there is no ut_line value in this record, fill
* it in by getting the TTY name and stuffing it in
* the structure. The UNIX/PC is broken in this regard
* and needs help ...
*/
if (utent.ut_line[0] == '\0')
#endif /* !UNIXPC */
{
if (!(line = ttyname(0))) {
puts(NO_TTY);
exit(1);
}
if (strncmp(line, "/dev/", 5) == 0)
line += 5;
strncpy(utent.ut_line, line, sizeof utent.ut_line);
#if HAVE_UTMPX_H
strncpy(utxent.ut_line, line, sizeof utxent.ut_line);
#endif
}
} else {
if (!(line = ttyname(0))) {
puts(NO_TTY);
exit(1);
}
if (strncmp(line, "/dev/", 5) == 0)
line += 5;
strncpy (utent.ut_line, line, sizeof utent.ut_line);
if ((ut = getutline(&utent)))
strncpy(utent.ut_id, ut->ut_id, sizeof ut->ut_id);
strcpy(utent.ut_user, "LOGIN");
utent.ut_pid = getpid();
utent.ut_type = LOGIN_PROCESS;
time(&utent.ut_time);
#if HAVE_UTMPX_H
strncpy(utxent.ut_line, line, sizeof utxent.ut_line);
if ((utx = getutxline(&utxent)))
strncpy(utxent.ut_id, utx->ut_id, sizeof utxent.ut_id);
strcpy(utxent.ut_user, "LOGIN");
utxent.ut_pid = utent.ut_pid;
utxent.ut_type = utent.ut_type;
gettimeofday((struct timeval *) &utxent.ut_tv, NULL);
utent.ut_time = utxent.ut_tv.tv_sec;
#endif
}
}
#else /* !USG */
void
checkutmp(int picky)
{
char *line;
/*
* Hand-craft a new utmp entry.
*/
memzero(&utent, sizeof utent);
if (! (line = ttyname (0))) {
puts (NO_TTY);
exit (1);
}
if (strncmp (line, "/dev/", 5) == 0)
line += 5;
(void) strncpy (utent.ut_line, line, sizeof utent.ut_line);
(void) time (&utent.ut_time);
}
#endif /* !USG */
/*
* Some systems already have updwtmp() and possibly updwtmpx(). Others
* don't, so we re-implement these functions if necessary. --marekm
*/
#ifndef HAVE_UPDWTMP
static void
updwtmp(const char *filename, const struct utmp *ut)
{
int fd;
fd = open(filename, O_APPEND | O_WRONLY, 0);
if (fd >= 0) {
write(fd, (const char *) ut, sizeof(*ut));
close(fd);
}
}
#endif /* ! HAVE_UPDWTMP */
#ifdef HAVE_UTMPX_H
#ifndef HAVE_UPDWTMPX
static void
updwtmpx(const char *filename, const struct utmpx *utx)
{
int fd;
fd = open(filename, O_APPEND | O_WRONLY, 0);
if (fd >= 0) {
write(fd, (const char *) utx, sizeof(*utx));
close(fd);
}
}
#endif /* ! HAVE_UPDWTMPX */
#endif /* ! HAVE_UTMPX_H */
/*
* setutmp - put a USER_PROCESS entry in the utmp file
*
* setutmp changes the type of the current utmp entry to
* USER_PROCESS. the wtmp file will be updated as well.
*/
#if defined(__linux__) /* XXX */
void
setutmp(const char *name, const char *line, const char *host)
{
utent.ut_type = USER_PROCESS;
strncpy(utent.ut_user, name, sizeof utent.ut_user);
time(&utent.ut_time);
/* other fields already filled in by checkutmp above */
setutent();
pututline(&utent);
endutent();
updwtmp(_WTMP_FILE, &utent);
}
#elif HAVE_UTMPX_H
void
setutmp(const char *name, const char *line, const char *host)
{
struct utmp *utmp, utline;
struct utmpx *utmpx, utxline;
pid_t pid = getpid ();
int found_utmpx = 0, found_utmp = 0;
/*
* The canonical device name doesn't include "/dev/"; skip it
* if it is already there.
*/
if (strncmp (line, "/dev/", 5) == 0)
line += 5;
/*
* Update utmpx. We create an empty entry in case there is
* no matching entry in the utmpx file.
*/
setutxent ();
setutent ();
while (utmpx = getutxent ()) {
if (utmpx->ut_pid == pid) {
found_utmpx = 1;
break;
}
}
while (utmp = getutent ()) {
if (utmp->ut_pid == pid) {
found_utmp = 1;
break;
}
}
/*
* If the entry matching `pid' cannot be found, create a new
* entry with the device name in it.
*/
if (! found_utmpx) {
memset ((void *) &utxline, 0, sizeof utxline);
strncpy (utxline.ut_line, line, sizeof utxline.ut_line);
utxline.ut_pid = getpid ();
} else {
utxline = *utmpx;
if (strncmp (utxline.ut_line, "/dev/", 5) == 0) {
memmove (utxline.ut_line, utxline.ut_line + 5,
sizeof utxline.ut_line - 5);
utxline.ut_line[sizeof utxline.ut_line - 5] = '\0';
}
}
if (! found_utmp) {
memset ((void *) &utline, 0, sizeof utline);
strncpy (utline.ut_line, utxline.ut_line,
sizeof utline.ut_line);
utline.ut_pid = utxline.ut_pid;
} else {
utline = *utmp;
if (strncmp (utline.ut_line, "/dev/", 5) == 0) {
memmove (utline.ut_line, utline.ut_line + 5,
sizeof utline.ut_line - 5);
utline.ut_line[sizeof utline.ut_line - 5] = '\0';
}
}
/*
* Fill in the fields in the utmpx entry and write it out. Do
* the utmp entry at the same time to make sure things don't
* get messed up.
*/
strncpy (utxline.ut_user, name, sizeof utxline.ut_user);
strncpy (utline.ut_user, name, sizeof utline.ut_user);
utline.ut_type = utxline.ut_type = USER_PROCESS;
gettimeofday(&utxline.ut_tv, NULL);
utline.ut_time = utxline.ut_tv.tv_sec;
strncpy(utxline.ut_host, host ? host : "", sizeof utxline.ut_host);
pututxline (&utxline);
pututline (&utline);
updwtmpx(_WTMP_FILE "x", &utxline);
updwtmp(_WTMP_FILE, &utline);
utxent = utxline;
utent = utline;
}
#else /* !SVR4 */
void
setutmp(const char *name, const char *line)
{
struct utmp utmp;
int fd;
int found = 0;
if ((fd = open(_UTMP_FILE, O_RDWR)) < 0)
return;
#if !defined(SUN) && !defined(BSD) && !defined(SUN4) /* XXX */
while (!found && read(fd, (char *)&utmp, sizeof utmp) == sizeof utmp) {
if (! strncmp (line, utmp.ut_line, (int) sizeof utmp.ut_line))
found++;
}
#endif
if (! found) {
/*
* This is a brand-new entry. Clear it out and fill it in
* later.
*/
memzero(&utmp, sizeof utmp);
strncpy(utmp.ut_line, line, (int) sizeof utmp.ut_line);
}
/*
* Fill in the parts of the UTMP entry. BSD has just the name,
* while System V has the name, PID and a type.
*/
strncpy(utmp.ut_user, name, sizeof utent.ut_user);
#ifdef USER_PROCESS
utmp.ut_type = USER_PROCESS;
utmp.ut_pid = getpid ();
#endif
/*
* Put in the current time (common to everyone)
*/
(void) time (&utmp.ut_time);
#ifdef UT_HOST
/*
* Update the host name field for systems with networking support
*/
(void) strncpy (utmp.ut_host, utent.ut_host, (int) sizeof utmp.ut_host);
#endif
/*
* Locate the correct position in the UTMP file for this
* entry.
*/
#ifdef HAVE_TTYSLOT
(void) lseek (fd, (off_t) (sizeof utmp) * ttyslot (), SEEK_SET);
#else
if (found) /* Back up a splot */
lseek (fd, (off_t) - sizeof utmp, SEEK_CUR);
else /* Otherwise, go to the end of the file */
lseek (fd, (off_t) 0, SEEK_END);
#endif
/*
* Scribble out the new entry and close the file. We're done
* with UTMP, next we do WTMP (which is real easy, put it on
* the end of the file.
*/
(void) write (fd, (char *) &utmp, sizeof utmp);
(void) close (fd);
updwtmp(_WTMP_FILE, &utmp);
utent = utmp;
}
#endif /* SVR4 */