shadow/src/lastlog.c
Tomas Mraz 4633164857 login.defs: Add LASTLOG_UID_MAX variable to limit lastlog to small uids.
As the large uids are usually provided by remote user identity and
authentication service, which also provide user login tracking,
there is no need to create a huge sparse file for them on every local
machine.

fixup! login.defs: Add LASTLOG_UID_MAX variable to limit lastlog to small uids.
2018-12-10 13:25:56 -06:00

450 lines
12 KiB
C

/*
* Copyright (c) 1989 - 1994, Julianne Frances Haugh
* Copyright (c) 1996 - 2000, Marek Michałkiewicz
* Copyright (c) 2000 - 2006, Tomasz Kłoczko
* Copyright (c) 2007 - 2011, Nicolas François
* 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 copyright holders or contributors may not be used to
* endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
* HOLDERS 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>
#ident "$Id$"
#include <getopt.h>
#include <lastlog.h>
#include <pwd.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <time.h>
#include <assert.h>
#include "defines.h"
#include "prototypes.h"
#include "getdef.h"
/*@-exitarg@*/
#include "exitcodes.h"
/*
* Needed for MkLinux DR1/2/2.1 - J.
*/
#ifndef LASTLOG_FILE
#define LASTLOG_FILE "/var/log/lastlog"
#endif
/*
* Global variables
*/
const char *Prog; /* Program name */
static FILE *lastlogfile; /* lastlog file stream */
static unsigned long umin; /* if uflg and has_umin, only display users with uid >= umin */
static bool has_umin = false;
static unsigned long umax; /* if uflg and has_umax, only display users with uid <= umax */
static bool has_umax = false;
static time_t seconds; /* that number of days in seconds */
static time_t inverse_seconds; /* that number of days in seconds */
static struct stat statbuf; /* fstat buffer for file size */
static bool uflg = false; /* print only an user of range of users */
static bool tflg = false; /* print is restricted to most recent days */
static bool bflg = false; /* print excludes most recent days */
static bool Cflg = false; /* clear record for user */
static bool Sflg = false; /* set record for user */
#define NOW (time ((time_t *) 0))
static /*@noreturn@*/void usage (int status)
{
FILE *usageout = (E_SUCCESS != status) ? stderr : stdout;
(void) fprintf (usageout,
_("Usage: %s [options]\n"
"\n"
"Options:\n"),
Prog);
(void) fputs (_(" -b, --before DAYS print only lastlog records older than DAYS\n"), usageout);
(void) fputs (_(" -C, --clear clear lastlog record of an user (usable only with -u)\n"), usageout);
(void) fputs (_(" -h, --help display this help message and exit\n"), usageout);
(void) fputs (_(" -R, --root CHROOT_DIR directory to chroot into\n"), usageout);
(void) fputs (_(" -S, --set set lastlog record to current time (usable only with -u)\n"), usageout);
(void) fputs (_(" -t, --time DAYS print only lastlog records more recent than DAYS\n"), usageout);
(void) fputs (_(" -u, --user LOGIN print lastlog record of the specified LOGIN\n"), usageout);
(void) fputs ("\n", usageout);
exit (status);
}
static void print_one (/*@null@*/const struct passwd *pw)
{
static bool once = false;
char *cp;
struct tm *tm;
time_t ll_time;
off_t offset;
struct lastlog ll;
#ifdef HAVE_STRFTIME
char ptime[80];
#endif
if (NULL == pw) {
return;
}
offset = (off_t) pw->pw_uid * sizeof (ll);
if (offset + sizeof (ll) <= statbuf.st_size) {
/* fseeko errors are not really relevant for us. */
int err = fseeko (lastlogfile, offset, SEEK_SET);
assert (0 == err);
/* lastlog is a sparse file. Even if no entries were
* entered for this user, which should be able to get the
* empty entry in this case.
*/
if (fread ((char *) &ll, sizeof (ll), 1, lastlogfile) != 1) {
fprintf (stderr,
_("%s: Failed to get the entry for UID %lu\n"),
Prog, (unsigned long int)pw->pw_uid);
exit (EXIT_FAILURE);
}
} else {
/* Outsize of the lastlog file.
* Behave as if there were a missing entry (same behavior
* as if we were reading an non existing entry in the
* sparse lastlog file).
*/
memzero (&ll, sizeof (ll));
}
/* Filter out entries that do not match with the -t or -b options */
if (tflg && ((NOW - ll.ll_time) > seconds)) {
return;
}
if (bflg && ((NOW - ll.ll_time) < inverse_seconds)) {
return;
}
/* Print the header only once */
if (!once) {
#ifdef HAVE_LL_HOST
puts (_("Username Port From Latest"));
#else
puts (_("Username Port Latest"));
#endif
once = true;
}
ll_time = ll.ll_time;
tm = localtime (&ll_time);
#ifdef HAVE_STRFTIME
strftime (ptime, sizeof (ptime), "%a %b %e %H:%M:%S %z %Y", tm);
cp = ptime;
#else
cp = asctime (tm);
cp[24] = '\0';
#endif
if (ll.ll_time == (time_t) 0) {
cp = _("**Never logged in**\0");
}
#ifdef HAVE_LL_HOST
printf ("%-16s %-8.8s %-16.16s %s\n",
pw->pw_name, ll.ll_line, ll.ll_host, cp);
#else
printf ("%-16s\t%-8.8s %s\n",
pw->pw_name, ll.ll_line, cp);
#endif
}
static void print (void)
{
const struct passwd *pwent;
unsigned long lastlog_uid_max;
lastlog_uid_max = getdef_ulong ("LASTLOG_UID_MAX", 0xFFFFFFFFUL);
if ( (has_umin && umin > lastlog_uid_max)
|| (has_umax && umax > lastlog_uid_max)) {
fprintf (stderr, _("%s: Selected uid(s) are higher than LASTLOG_UID_MAX (%lu),\n"
"\tthe output might be incorrect.\n"), Prog, lastlog_uid_max);
}
if (uflg && has_umin && has_umax && (umin == umax)) {
print_one (getpwuid ((uid_t)umin));
} else {
setpwent ();
while ( (pwent = getpwent ()) != NULL ) {
if ( uflg
&& ( (has_umin && (pwent->pw_uid < (uid_t)umin))
|| (has_umax && (pwent->pw_uid > (uid_t)umax)))) {
continue;
} else if ( !uflg && pwent->pw_uid > (uid_t) lastlog_uid_max) {
continue;
}
print_one (pwent);
}
endpwent ();
}
}
static void update_one (/*@null@*/const struct passwd *pw)
{
off_t offset;
struct lastlog ll;
int err;
if (NULL == pw) {
return;
}
offset = (off_t) pw->pw_uid * sizeof (ll);
/* fseeko errors are not really relevant for us. */
err = fseeko (lastlogfile, offset, SEEK_SET);
assert (0 == err);
memzero (&ll, sizeof (ll));
if (Sflg) {
ll.ll_time = NOW;
#ifdef HAVE_LL_HOST
strcpy (ll.ll_host, "localhost");
#endif
strcpy (ll.ll_line, "lastlog");
#ifdef WITH_AUDIT
audit_logger (AUDIT_ACCT_UNLOCK, Prog,
"clearing-lastlog",
pw->pw_name, (unsigned int) pw->pw_uid, SHADOW_AUDIT_SUCCESS);
#endif
}
#ifdef WITH_AUDIT
else {
audit_logger (AUDIT_ACCT_UNLOCK, Prog,
"refreshing-lastlog",
pw->pw_name, (unsigned int) pw->pw_uid, SHADOW_AUDIT_SUCCESS);
}
#endif
if (fwrite (&ll, sizeof(ll), 1, lastlogfile) != 1) {
fprintf (stderr,
_("%s: Failed to update the entry for UID %lu\n"),
Prog, (unsigned long int)pw->pw_uid);
exit (EXIT_FAILURE);
}
}
static void update (void)
{
const struct passwd *pwent;
unsigned long lastlog_uid_max;
if (!uflg) /* safety measure */
return;
lastlog_uid_max = getdef_ulong ("LASTLOG_UID_MAX", 0xFFFFFFFFUL);
if ( (has_umin && umin > lastlog_uid_max)
|| (has_umax && umax > lastlog_uid_max)) {
fprintf (stderr, _("%s: Selected uid(s) are higher than LASTLOG_UID_MAX (%lu),\n"
"\tthey will not be updated.\n"), Prog, lastlog_uid_max);
return;
}
if (has_umin && has_umax && (umin == umax)) {
update_one (getpwuid ((uid_t)umin));
} else {
setpwent ();
while ( (pwent = getpwent ()) != NULL ) {
if ((has_umin && (pwent->pw_uid < (uid_t)umin))
|| (has_umax && (pwent->pw_uid > (uid_t)umax))) {
continue;
}
update_one (pwent);
}
endpwent ();
}
if (fflush (lastlogfile) != 0 || fsync (fileno (lastlogfile)) != 0) {
fprintf (stderr,
_("%s: Failed to update the lastlog file\n"),
Prog);
exit (EXIT_FAILURE);
}
}
int main (int argc, char **argv)
{
/*
* Get the program name. The program name is used as a prefix to
* most error messages.
*/
Prog = Basename (argv[0]);
(void) setlocale (LC_ALL, "");
(void) bindtextdomain (PACKAGE, LOCALEDIR);
(void) textdomain (PACKAGE);
process_root_flag ("-R", argc, argv);
#ifdef WITH_AUDIT
audit_help_open ();
#endif
{
int c;
static struct option const longopts[] = {
{"before", required_argument, NULL, 'b'},
{"clear", no_argument, NULL, 'C'},
{"help", no_argument, NULL, 'h'},
{"root", required_argument, NULL, 'R'},
{"set", no_argument, NULL, 'S'},
{"time", required_argument, NULL, 't'},
{"user", required_argument, NULL, 'u'},
{NULL, 0, NULL, '\0'}
};
while ((c = getopt_long (argc, argv, "b:ChR:St:u:", longopts,
NULL)) != -1) {
switch (c) {
case 'b':
{
unsigned long inverse_days;
if (getulong (optarg, &inverse_days) == 0) {
fprintf (stderr,
_("%s: invalid numeric argument '%s'\n"),
Prog, optarg);
exit (EXIT_FAILURE);
}
inverse_seconds = (time_t) inverse_days * DAY;
bflg = true;
break;
}
case 'C':
{
Cflg = true;
break;
}
case 'h':
usage (EXIT_SUCCESS);
/*@notreached@*/break;
case 'R': /* no-op, handled in process_root_flag () */
break;
case 'S':
{
Sflg = true;
break;
}
case 't':
{
unsigned long days;
if (getulong (optarg, &days) == 0) {
fprintf (stderr,
_("%s: invalid numeric argument '%s'\n"),
Prog, optarg);
exit (EXIT_FAILURE);
}
seconds = (time_t) days * DAY;
tflg = true;
break;
}
case 'u':
{
const struct passwd *pwent;
/*
* The user can be:
* - a login name
* - numerical
* - a numerical login ID
* - a range (-x, x-, x-y)
*/
uflg = true;
/* local, no need for xgetpwnam */
pwent = getpwnam (optarg);
if (NULL != pwent) {
umin = (unsigned long) pwent->pw_uid;
has_umin = true;
umax = umin;
has_umax = true;
} else {
if (getrange (optarg,
&umin, &has_umin,
&umax, &has_umax) == 0) {
fprintf (stderr,
_("%s: Unknown user or range: %s\n"),
Prog, optarg);
exit (EXIT_FAILURE);
}
}
break;
}
default:
usage (EXIT_FAILURE);
/*@notreached@*/break;
}
}
if (argc > optind) {
fprintf (stderr,
_("%s: unexpected argument: %s\n"),
Prog, argv[optind]);
usage (EXIT_FAILURE);
}
if (Cflg && Sflg) {
fprintf (stderr,
_("%s: Option -C cannot be used together with option -S\n"),
Prog);
usage (EXIT_FAILURE);
}
if ((Cflg || Sflg) && !uflg) {
fprintf (stderr,
_("%s: Options -C and -S require option -u to specify the user\n"),
Prog);
usage (EXIT_FAILURE);
}
}
lastlogfile = fopen (LASTLOG_FILE, (Cflg || Sflg)?"r+":"r");
if (NULL == lastlogfile) {
perror (LASTLOG_FILE);
exit (EXIT_FAILURE);
}
/* Get the lastlog size */
if (fstat (fileno (lastlogfile), &statbuf) != 0) {
fprintf (stderr,
_("%s: Cannot get the size of %s: %s\n"),
Prog, LASTLOG_FILE, strerror (errno));
exit (EXIT_FAILURE);
}
if (Cflg || Sflg)
update ();
else
print ();
(void) fclose (lastlogfile);
return EXIT_SUCCESS;
}