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shadow/src/lastlog.c

440 lines
11 KiB

/*
* SPDX-FileCopyrightText: 1989 - 1994, Julianne Frances Haugh
* SPDX-FileCopyrightText: 1996 - 2000, Marek Michałkiewicz
* SPDX-FileCopyrightText: 2000 - 2006, Tomasz Kłoczko
* SPDX-FileCopyrightText: 2007 - 2011, Nicolas François
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#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>
#ifdef HAVE_LL_HOST
#include <net/if.h>
#endif
#include "defines.h"
#include "prototypes.h"
#include "getdef.h"
/*@-exitarg@*/
#include "exitcodes.h"
#include "shadowlog.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;
char ptime[80];
#ifdef HAVE_LL_HOST
/*
* ll_host is in minimized form, thus the maximum IPv6 address possible is
* 8*4+7 = 39 characters.
* RFC 4291 2.5.6 states that for LL-addresses fe80+only the interface ID is set,
* thus having a maximum size of 25+1+IFNAMSIZ.
* POSIX says IFNAMSIZ should be 16 characters long including the null byte, thus
* 25+1+IFNAMSIZ >= 42 > 39
*/
/* Link-Local address + % + Interfacename */
const int maxIPv6Addrlen = 25+1+IFNAMSIZ;
#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
printf (_("Username Port From%*sLatest\n"), maxIPv6Addrlen-3, " ");
#else
puts (_("Username Port Latest"));
#endif
once = true;
}
ll_time = ll.ll_time;
tm = localtime (&ll_time);
if (tm == NULL) {
cp = "(unknown)";
} else {
strftime (ptime, sizeof (ptime), "%a %b %e %H:%M:%S %z %Y", tm);
cp = ptime;
}
if (ll.ll_time == (time_t) 0) {
cp = _("**Never logged in**\0");
}
#ifdef HAVE_LL_HOST
printf ("%-16s %-8.8s %*s%s\n",
pw->pw_name, ll.ll_line, -maxIPv6Addrlen, 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]);
log_set_progname(Prog);
log_set_logfd(stderr);
(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;
}