shadow/src/faillog.c
Alejandro Colomar bddcd9b095 Remove superfluous casts
-  Every non-const pointer converts automatically to void *.
-  Every pointer converts automatically to void *.
-  void * converts to any other pointer.
-  const void * converts to any other const pointer.
-  Integer variables convert to each other.

I changed the declaration of a few variables in order to allow removing
a cast.

However, I didn't attempt to edit casts inside comparisons, since they
are very delicate.  I also kept casts in variadic functions, since they
are necessary, and in allocation functions, because I have other plans
for them.

I also changed a few casts to int that are better as ptrdiff_t.

This change has triggered some warnings about const correctness issues,
which have also been fixed in this patch (see for example src/login.c).

Signed-off-by: Alejandro Colomar <alx@kernel.org>
2023-02-09 10:03:03 -06:00

723 lines
18 KiB
C

/*
* SPDX-FileCopyrightText: 1989 - 1993, Julianne Frances Haugh
* SPDX-FileCopyrightText: 1996 - 2000, Marek Michałkiewicz
* SPDX-FileCopyrightText: 2002 - 2006, Tomasz Kłoczko
* SPDX-FileCopyrightText: 2007 - 2011, Nicolas François
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <config.h>
#ident "$Id$"
#include <getopt.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 "faillog.h"
#include "prototypes.h"
/*@-exitarg@*/
#include "exitcodes.h"
#include "shadowlog.h"
/* local function prototypes */
NORETURN static void usage (int status);
static void print_one (/*@null@*/const struct passwd *pw, bool force);
static void set_locktime (long locktime);
static bool set_locktime_one (uid_t uid, long locktime);
static void setmax (short max);
static bool setmax_one (uid_t uid, short max);
static void print (void);
static bool reset_one (uid_t uid);
static void reset (void);
/*
* Global variables
*/
const char *Prog; /* Program name */
static FILE *fail; /* failure file stream */
static time_t seconds; /* that number of days in seconds */
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 bool errors = false;
static bool aflg = false; /* set if all users are to be printed always */
static bool uflg = false; /* set if user is a valid user id */
static bool tflg = false; /* print is restricted to most recent days */
static bool lflg = false; /* set the locktime */
static bool mflg = false; /* set maximum failed login counters */
static bool rflg = false; /* reset the counters of login failures */
static struct stat statbuf; /* fstat buffer for file size */
#define NOW time(NULL)
NORETURN
static void
usage (int status)
{
FILE *usageout = (E_SUCCESS != status) ? stderr : stdout;
(void) fprintf (usageout,
_("Usage: %s [options]\n"
"\n"
"Options:\n"),
Prog);
(void) fputs (_(" -a, --all display faillog records for all users\n"), usageout);
(void) fputs (_(" -h, --help display this help message and exit\n"), usageout);
(void) fputs (_(" -l, --lock-secs SEC after failed login lock account for SEC seconds\n"), usageout);
(void) fputs (_(" -m, --maximum MAX set maximum failed login counters to MAX\n"), usageout);
(void) fputs (_(" -r, --reset reset the counters of login failures\n"), usageout);
(void) fputs (_(" -R, --root CHROOT_DIR directory to chroot into\n"), usageout);
(void) fputs (_(" -t, --time DAYS display faillog records more recent than DAYS\n"), usageout);
(void) fputs (_(" -u, --user LOGIN/RANGE display faillog record or maintains failure\n"
" counters and limits (if used with -r, -m,\n"
" or -l) only for the specified LOGIN(s)\n"), usageout);
(void) fputs ("\n", usageout);
exit (status);
}
static void print_one (/*@null@*/const struct passwd *pw, bool force)
{
static bool once = false;
struct tm *tm;
off_t offset;
struct faillog fl;
time_t now;
char *cp;
char ptime[80];
if (NULL == pw) {
return;
}
offset = (off_t) pw->pw_uid * sizeof (fl);
if (offset + sizeof (fl) <= statbuf.st_size) {
/* fseeko errors are not really relevant for us. */
int err = fseeko (fail, offset, SEEK_SET);
assert (0 == err);
/* faillog 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 (&fl, sizeof (fl), 1, fail) != 1) {
fprintf (stderr,
_("%s: Failed to get the entry for UID %lu\n"),
Prog, (unsigned long int)pw->pw_uid);
return;
}
} else {
/* Outsize of the faillog file.
* Behave as if there were a missing entry (same behavior
* as if we were reading an non existing entry in the
* sparse faillog file).
*/
memzero (&fl, sizeof (fl));
}
/* Nothing to report */
if (!force && (0 == fl.fail_time)) {
return;
}
(void) time(&now);
/* Filter out entries that do not match with the -t option */
if (tflg && ((now - fl.fail_time) > seconds)) {
return;
}
/* Print the header only once */
if (!once) {
puts (_("Login Failures Maximum Latest On\n"));
once = true;
}
tm = localtime (&fl.fail_time);
if (!tm) {
fprintf (stderr, "Cannot read time from faillog.\n");
return;
}
strftime (ptime, sizeof (ptime), "%D %H:%M:%S %z", tm);
cp = ptime;
printf ("%-9s %5d %5d ",
pw->pw_name, fl.fail_cnt, fl.fail_max);
printf ("%s %s", cp, fl.fail_line);
if (0 != fl.fail_locktime) {
if ( ((fl.fail_time + fl.fail_locktime) > now)
&& (0 != fl.fail_cnt)) {
printf (_(" [%lus left]"),
(unsigned long) fl.fail_time + fl.fail_locktime - now);
} else {
printf (_(" [%lds lock]"),
fl.fail_locktime);
}
}
putchar ('\n');
}
static void print (void)
{
if (uflg && has_umin && has_umax && (umin==umax)) {
print_one (getpwuid (umin), true);
} else {
/* We only print records for existing users.
* Loop based on the user database instead of reading the
* whole file. We will have to query the database anyway
* so except for very small ranges and large user
* database, this should not be a performance issue.
*/
struct passwd *pwent;
setpwent ();
while ( (pwent = getpwent ()) != NULL ) {
if ( uflg
&& ( (has_umin && (pwent->pw_uid < (uid_t)umin))
|| (has_umax && (pwent->pw_uid > (uid_t)umax)))) {
continue;
}
print_one (pwent, aflg);
}
endpwent ();
}
}
/*
* reset_one - Reset the fail count for one user
*
* This returns a boolean indicating if an error occurred.
*/
static bool reset_one (uid_t uid)
{
off_t offset;
struct faillog fl;
offset = (off_t) uid * sizeof (fl);
if (offset + sizeof (fl) <= statbuf.st_size) {
/* fseeko errors are not really relevant for us. */
int err = fseeko (fail, offset, SEEK_SET);
assert (0 == err);
/* faillog 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 (&fl, sizeof (fl), 1, fail) != 1) {
fprintf (stderr,
_("%s: Failed to get the entry for UID %lu\n"),
Prog, (unsigned long int)uid);
return true;
}
} else {
/* Outsize of the faillog file.
* Behave as if there were a missing entry (same behavior
* as if we were reading an non existing entry in the
* sparse faillog file).
*/
memzero (&fl, sizeof (fl));
}
if (0 == fl.fail_cnt) {
/* If the count is already null, do not write in the file.
* This avoids writing 0 when no entries were present for
* the user.
*/
return false;
}
fl.fail_cnt = 0;
if ( (fseeko (fail, offset, SEEK_SET) == 0)
&& (fwrite (&fl, sizeof (fl), 1, fail) == 1)) {
(void) fflush (fail);
return false;
}
fprintf (stderr,
_("%s: Failed to reset fail count for UID %lu\n"),
Prog, (unsigned long int)uid);
return true;
}
static void reset (void)
{
if (uflg && has_umin && has_umax && (umin==umax)) {
if (reset_one (umin)) {
errors = true;
}
} else {
/* There is no need to reset outside of the faillog
* database.
*/
uid_t uidmax = statbuf.st_size / sizeof (struct faillog);
if (uidmax > 1) {
uidmax--;
}
if (has_umax && (uid_t)umax < uidmax) {
uidmax = umax;
}
/* Reset all entries in the specified range.
* Non existing entries will not be touched.
*/
if (aflg) {
/* Entries for non existing users are also reset.
*/
uid_t uid = 0;
/* Make sure we stay in the umin-umax range if specified */
if (has_umin) {
uid = umin;
}
while (uid <= uidmax) {
if (reset_one (uid)) {
errors = true;
}
uid++;
}
} else {
/* Only reset records for existing users.
*/
struct passwd *pwent;
setpwent ();
while ( (pwent = getpwent ()) != NULL ) {
if ( uflg
&& ( (has_umin && (pwent->pw_uid < (uid_t)umin))
|| (pwent->pw_uid > (uid_t)uidmax))) {
continue;
}
if (reset_one (pwent->pw_uid)) {
errors = true;
}
}
endpwent ();
}
}
}
/*
* setmax_one - Set the maximum failed login counter for one user
*
* This returns a boolean indicating if an error occurred.
*/
static bool setmax_one (uid_t uid, short max)
{
off_t offset;
struct faillog fl;
offset = (off_t) uid * sizeof (fl);
if (offset + sizeof (fl) <= statbuf.st_size) {
/* fseeko errors are not really relevant for us. */
int err = fseeko (fail, offset, SEEK_SET);
assert (0 == err);
/* faillog 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 (&fl, sizeof (fl), 1, fail) != 1) {
fprintf (stderr,
_("%s: Failed to get the entry for UID %lu\n"),
Prog, (unsigned long int)uid);
return true;
}
} else {
/* Outsize of the faillog file.
* Behave as if there were a missing entry (same behavior
* as if we were reading an non existing entry in the
* sparse faillog file).
*/
memzero (&fl, sizeof (fl));
}
if (max == fl.fail_max) {
/* If the max is already set to the right value, do not
* write in the file.
* This avoids writing 0 when no entries were present for
* the user and the max argument is 0.
*/
return false;
}
fl.fail_max = max;
if ( (fseeko (fail, offset, SEEK_SET) == 0)
&& (fwrite (&fl, sizeof (fl), 1, fail) == 1)) {
(void) fflush (fail);
return false;
}
fprintf (stderr,
_("%s: Failed to set max for UID %lu\n"),
Prog, (unsigned long int)uid);
return true;
}
static void setmax (short max)
{
if (uflg && has_umin && has_umax && (umin==umax)) {
if (setmax_one (umin, max)) {
errors = true;
}
} else {
/* Set max for entries in the specified range.
* If max is unchanged for an entry, the entry is not touched.
* If max is null, and no entries exist for this user, no
* entries will be created.
*/
if (aflg) {
/* Entries for non existing user are also taken into
* account (in order to define policy for future users).
*/
uid_t uid = 0;
/* The default umax value is based on the size of the
* faillog database.
*/
uid_t uidmax = statbuf.st_size / sizeof (struct faillog);
if (uidmax > 1) {
uidmax--;
}
/* Make sure we stay in the umin-umax range if specified */
if (has_umin) {
uid = umin;
}
if (has_umax) {
uidmax = umax;
}
while (uid <= uidmax) {
if (setmax_one (uid, max)) {
errors = true;
}
uid++;
}
} else {
/* Only change records for existing users.
*/
struct passwd *pwent;
setpwent ();
while ( (pwent = getpwent ()) != NULL ) {
if ( uflg
&& ( (has_umin && (pwent->pw_uid < (uid_t)umin))
|| (has_umax && (pwent->pw_uid > (uid_t)umax)))) {
continue;
}
if (setmax_one (pwent->pw_uid, max)) {
errors = true;
}
}
endpwent ();
}
}
}
/*
* set_locktime_one - Set the locktime for one user
*
* This returns a boolean indicating if an error occurred.
*/
static bool set_locktime_one (uid_t uid, long locktime)
{
off_t offset;
struct faillog fl;
offset = (off_t) uid * sizeof (fl);
if (offset + sizeof (fl) <= statbuf.st_size) {
/* fseeko errors are not really relevant for us. */
int err = fseeko (fail, offset, SEEK_SET);
assert (0 == err);
/* faillog 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 (&fl, sizeof (fl), 1, fail) != 1) {
fprintf (stderr,
_("%s: Failed to get the entry for UID %lu\n"),
Prog, (unsigned long int)uid);
return true;
}
} else {
/* Outsize of the faillog file.
* Behave as if there were a missing entry (same behavior
* as if we were reading an non existing entry in the
* sparse faillog file).
*/
memzero (&fl, sizeof (fl));
}
if (locktime == fl.fail_locktime) {
/* If the locktime is already set to the right value, do not
* write in the file.
* This avoids writing 0 when no entries were present for
* the user and the locktime argument is 0.
*/
return false;
}
fl.fail_locktime = locktime;
if ( (fseeko (fail, offset, SEEK_SET) == 0)
&& (fwrite (&fl, sizeof (fl), 1, fail) == 1)) {
(void) fflush (fail);
return false;
}
fprintf (stderr,
_("%s: Failed to set locktime for UID %lu\n"),
Prog, (unsigned long int)uid);
return true;
}
static void set_locktime (long locktime)
{
if (uflg && has_umin && has_umax && (umin==umax)) {
if (set_locktime_one (umin, locktime)) {
errors = true;
}
} else {
/* Set locktime for entries in the specified range.
* If locktime is unchanged for an entry, the entry is not touched.
* If locktime is null, and no entries exist for this user, no
* entries will be created.
*/
if (aflg) {
/* Entries for non existing user are also taken into
* account (in order to define policy for future users).
*/
uid_t uid = 0;
/* The default umax value is based on the size of the
* faillog database.
*/
uid_t uidmax = statbuf.st_size / sizeof (struct faillog);
if (uidmax > 1) {
uidmax--;
}
/* Make sure we stay in the umin-umax range if specified */
if (has_umin) {
uid = umin;
}
if (has_umax) {
uidmax = umax;
}
while (uid <= uidmax) {
if (set_locktime_one (uid, locktime)) {
errors = true;
}
uid++;
}
} else {
/* Only change records for existing users.
*/
struct passwd *pwent;
setpwent ();
while ( (pwent = getpwent ()) != NULL ) {
if ( uflg
&& ( (has_umin && (pwent->pw_uid < (uid_t)umin))
|| (has_umax && (pwent->pw_uid > (uid_t)umax)))) {
continue;
}
if (set_locktime_one (pwent->pw_uid, locktime)) {
errors = true;
}
}
endpwent ();
}
}
}
int main (int argc, char **argv)
{
long fail_locktime = 0;
short fail_max = 0; // initialize to silence compiler warning
long days = 0;
/*
* 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);
{
int c;
static struct option long_options[] = {
{"all", no_argument, NULL, 'a'},
{"help", no_argument, NULL, 'h'},
{"lock-secs", required_argument, NULL, 'l'},
{"maximum", required_argument, NULL, 'm'},
{"reset", no_argument, NULL, 'r'},
{"root", required_argument, NULL, 'R'},
{"time", required_argument, NULL, 't'},
{"user", required_argument, NULL, 'u'},
{NULL, 0, NULL, '\0'}
};
while ((c = getopt_long (argc, argv, "ahl:m:rR:t:u:",
long_options, NULL)) != -1) {
switch (c) {
case 'a':
aflg = true;
break;
case 'h':
usage (E_SUCCESS);
/*@notreached@*/break;
case 'l':
if (getlong (optarg, &fail_locktime) == 0) {
fprintf (stderr,
_("%s: invalid numeric argument '%s'\n"),
Prog, optarg);
exit (E_BAD_ARG);
}
lflg = true;
break;
case 'm':
{
long int lmax;
if ( (getlong (optarg, &lmax) == 0)
|| ((long int)(short) lmax != lmax)) {
fprintf (stderr,
_("%s: invalid numeric argument '%s'\n"),
Prog, optarg);
exit (E_BAD_ARG);
}
fail_max = lmax;
mflg = true;
break;
}
case 'r':
rflg = true;
break;
case 'R': /* no-op, handled in process_root_flag () */
break;
case 't':
if (getlong (optarg, &days) == 0) {
fprintf (stderr,
_("%s: invalid numeric argument '%s'\n"),
Prog, optarg);
exit (E_BAD_ARG);
}
seconds = (time_t) days * DAY;
tflg = true;
break;
case 'u':
{
/*
* The user can be:
* - a login name
* - numerical
* - a numerical login ID
* - a range (-x, x-, x-y)
*/
struct passwd *pwent;
uflg = true;
/* local, no need for xgetpwnam */
pwent = getpwnam (optarg);
if (NULL != pwent) {
umin = 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 (E_BAD_ARG);
}
}
break;
}
default:
usage (E_USAGE);
}
}
if (argc > optind) {
fprintf (stderr,
_("%s: unexpected argument: %s\n"),
Prog, argv[optind]);
usage (EXIT_FAILURE);
}
}
if (tflg && (lflg || mflg || rflg)) {
usage (E_USAGE);
}
/* Open the faillog database */
if (lflg || mflg || rflg) {
fail = fopen (FAILLOG_FILE, "r+");
} else {
fail = fopen (FAILLOG_FILE, "r");
}
if (NULL == fail) {
fprintf (stderr,
_("%s: Cannot open %s: %s\n"),
Prog, FAILLOG_FILE, strerror (errno));
exit (E_NOPERM);
}
/* Get the size of the faillog */
if (fstat (fileno (fail), &statbuf) != 0) {
fprintf (stderr,
_("%s: Cannot get the size of %s: %s\n"),
Prog, FAILLOG_FILE, strerror (errno));
exit (E_NOPERM);
}
if (lflg) {
set_locktime (fail_locktime);
}
if (mflg) {
setmax (fail_max);
}
if (rflg) {
reset ();
}
if (!(lflg || mflg || rflg)) {
print ();
}
if (lflg || mflg || rflg) {
if ( (ferror (fail) != 0)
|| (fflush (fail) != 0)
|| (fsync (fileno (fail)) != 0)
|| (fclose (fail) != 0)) {
fprintf (stderr,
_("%s: Failed to write %s: %s\n"),
Prog, FAILLOG_FILE, strerror (errno));
(void) fclose (fail);
errors = true;
}
} else {
(void) fclose (fail);
}
exit (errors ? E_NOPERM : E_SUCCESS);
}