shadow/src/pwunconv.c

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/*
* Copyright (c) 1989 - 1994, Julianne Frances Haugh
* Copyright (c) 1996 - 2000, Marek Michałkiewicz
* Copyright (c) 2001 - 2005, Tomasz Kłoczko
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* Copyright (c) 2008 - 2012, 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 <fcntl.h>
#include <pwd.h>
#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <getopt.h>
#include "defines.h"
#include "nscd.h"
Flush sssd caches in addition to nscd caches Some distributions, notably Fedora, have the following order of nsswitch modules by default: passwd: sss files group: sss files The advantage of serving local users through SSSD is that the nss_sss module has a fast mmapped-cache that speeds up NSS lookups compared to accessing the disk an opening the files on each NSS request. Traditionally, this has been done with the help of nscd, but using nscd in parallel with sssd is cumbersome, as both SSSD and nscd use their own independent caching, so using nscd in setups where sssd is also serving users from some remote domain (LDAP, AD, ...) can result in a bit of unpredictability. More details about why Fedora chose to use sss before files can be found on e.g.: https://fedoraproject.org//wiki/Changes/SSSDCacheForLocalUsers or: https://docs.pagure.org/SSSD.sssd/design_pages/files_provider.html Now, even though sssd watches the passwd and group files with the help of inotify, there can still be a small window where someone requests a user or a group, finds that it doesn't exist, adds the entry and checks again. Without some support in shadow-utils that would explicitly drop the sssd caches, the inotify watch can fire a little late, so a combination of commands like this: getent passwd user || useradd user; getent passwd user can result in the second getent passwd not finding the newly added user as the racy behaviour might still return the cached negative hit from the first getent passwd. This patch more or less copies the already existing support that shadow-utils had for dropping nscd caches, except using the "sss_cache" tool that sssd ships.
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#include "sssd.h"
#include "prototypes.h"
#include "pwio.h"
#include "shadowio.h"
/*@-exitarg@*/
#include "exitcodes.h"
/*
* Global variables
*/
const char *Prog;
FILE *shadow_logfd = NULL;
static bool spw_locked = false;
static bool pw_locked = false;
/* local function prototypes */
static void fail_exit (int status);
static void usage (int status);
static void process_flags (int argc, char **argv);
static void fail_exit (int status)
{
if (spw_locked) {
if (spw_unlock () == 0) {
fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, spw_dbname ());
SYSLOG ((LOG_ERR, "failed to unlock %s", spw_dbname ()));
/* continue */
}
}
if (pw_locked) {
if (pw_unlock () == 0) {
fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, pw_dbname ());
SYSLOG ((LOG_ERR, "failed to unlock %s", pw_dbname ()));
/* continue */
}
}
exit (status);
}
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 (_(" -h, --help display this help message and exit\n"), usageout);
(void) fputs (_(" -R, --root CHROOT_DIR directory to chroot into\n"), usageout);
(void) fputs ("\n", usageout);
exit (status);
}
/*
* process_flags - parse the command line options
*
* It will not return if an error is encountered.
*/
static void process_flags (int argc, char **argv)
{
/*
* Parse the command line options.
*/
int c;
static struct option long_options[] = {
{"help", no_argument, NULL, 'h'},
{"root", required_argument, NULL, 'R'},
{NULL, 0, NULL, '\0'}
};
while ((c = getopt_long (argc, argv, "hR:",
long_options, NULL)) != -1) {
switch (c) {
case 'h':
usage (E_SUCCESS);
/*@notreached@*/break;
case 'R': /* no-op, handled in process_root_flag () */
break;
default:
usage (E_USAGE);
}
}
if (optind != argc) {
usage (E_USAGE);
}
}
int main (int argc, char **argv)
{
const struct passwd *pw;
struct passwd pwent;
const struct spwd *spwd;
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Prog = Basename (argv[0]);
shadow_logfd = stderr;
(void) setlocale (LC_ALL, "");
(void) bindtextdomain (PACKAGE, LOCALEDIR);
(void) textdomain (PACKAGE);
process_root_flag ("-R", argc, argv);
OPENLOG ("pwunconv");
process_flags (argc, argv);
#ifdef WITH_TCB
if (getdef_bool("USE_TCB")) {
fprintf (stderr, _("%s: can't work with tcb enabled\n"), Prog);
exit (1);
}
#endif /* WITH_TCB */
if (!spw_file_present ()) {
/* shadow not installed, do nothing */
exit (0);
}
if (pw_lock () == 0) {
* lib/groupio.c, lib/groupio.h, lib/pwio.c, lib/pwio.h, lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h: Added *_dbname() functions to retrieve the name of the databases. * lib/groupio.c, lib/groupio.h, lib/pwio.c, lib/pwio.h, lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h: *_name() functions renamed *setname(). * src/grpck.c, src/pwck.c: Likewise. * lib/groupio.h, lib/pwio.h, lib/sgroupio.h, lib/shadowio.h: Added the name of the arguments to the prototypes. * src/chage, src/chfn.c, src/chgpasswd.c, src/chpasswd.c, src/chsh.c, src/gpasswd.c, src/groupadd.c, src/groupdel.c, src/groupmod.c, src/grpck.c, src/grpconv.c, src/grpunconv.c, src/newusers.c, src/passwd.c, src/pwck.c, src/pwconv.c, src/pwunconv.c, src/useradd.c, src/userdel.c, src/usermod.c: Harmonize the erro & syslog messages in case of failure of the *_lock(), *_open(), *_close(), *_unlock(), *_remove() functions. * src/chgpasswd.c, src/chpasswd.c, src/usermod.c: Avoid capitalized messages. * src/chpasswd.c, src/useradd.c, src/usermod.c: Harmonize messages in case of inexistent entries. * src/usermod.c: Harmonize messages in case of already existing entries. * src/newusers.c, src/useradd.c: Simplify PAM error handling. * src/useradd.c: Report failures to unlock files (stderr, syslog, and audit). But do not fail (continue). * src/useradd.c (open_files): Do not report to syslog & audit failures to lock or open the databases. This might be harmless, and the logs were not already informed that a change was requested. * src/usermod.c: It's not the account which is unlocked, but its password.
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fprintf (stderr,
_("%s: cannot lock %s; try again later.\n"),
* lib/groupio.c, lib/groupio.h, lib/pwio.c, lib/pwio.h, lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h: Added *_dbname() functions to retrieve the name of the databases. * lib/groupio.c, lib/groupio.h, lib/pwio.c, lib/pwio.h, lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h: *_name() functions renamed *setname(). * src/grpck.c, src/pwck.c: Likewise. * lib/groupio.h, lib/pwio.h, lib/sgroupio.h, lib/shadowio.h: Added the name of the arguments to the prototypes. * src/chage, src/chfn.c, src/chgpasswd.c, src/chpasswd.c, src/chsh.c, src/gpasswd.c, src/groupadd.c, src/groupdel.c, src/groupmod.c, src/grpck.c, src/grpconv.c, src/grpunconv.c, src/newusers.c, src/passwd.c, src/pwck.c, src/pwconv.c, src/pwunconv.c, src/useradd.c, src/userdel.c, src/usermod.c: Harmonize the erro & syslog messages in case of failure of the *_lock(), *_open(), *_close(), *_unlock(), *_remove() functions. * src/chgpasswd.c, src/chpasswd.c, src/usermod.c: Avoid capitalized messages. * src/chpasswd.c, src/useradd.c, src/usermod.c: Harmonize messages in case of inexistent entries. * src/usermod.c: Harmonize messages in case of already existing entries. * src/newusers.c, src/useradd.c: Simplify PAM error handling. * src/useradd.c: Report failures to unlock files (stderr, syslog, and audit). But do not fail (continue). * src/useradd.c (open_files): Do not report to syslog & audit failures to lock or open the databases. This might be harmless, and the logs were not already informed that a change was requested. * src/usermod.c: It's not the account which is unlocked, but its password.
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Prog, pw_dbname ());
fail_exit (5);
}
pw_locked = true;
if (pw_open (O_CREAT | O_RDWR) == 0) {
* lib/groupio.c, lib/groupio.h, lib/pwio.c, lib/pwio.h, lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h: Added *_dbname() functions to retrieve the name of the databases. * lib/groupio.c, lib/groupio.h, lib/pwio.c, lib/pwio.h, lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h: *_name() functions renamed *setname(). * src/grpck.c, src/pwck.c: Likewise. * lib/groupio.h, lib/pwio.h, lib/sgroupio.h, lib/shadowio.h: Added the name of the arguments to the prototypes. * src/chage, src/chfn.c, src/chgpasswd.c, src/chpasswd.c, src/chsh.c, src/gpasswd.c, src/groupadd.c, src/groupdel.c, src/groupmod.c, src/grpck.c, src/grpconv.c, src/grpunconv.c, src/newusers.c, src/passwd.c, src/pwck.c, src/pwconv.c, src/pwunconv.c, src/useradd.c, src/userdel.c, src/usermod.c: Harmonize the erro & syslog messages in case of failure of the *_lock(), *_open(), *_close(), *_unlock(), *_remove() functions. * src/chgpasswd.c, src/chpasswd.c, src/usermod.c: Avoid capitalized messages. * src/chpasswd.c, src/useradd.c, src/usermod.c: Harmonize messages in case of inexistent entries. * src/usermod.c: Harmonize messages in case of already existing entries. * src/newusers.c, src/useradd.c: Simplify PAM error handling. * src/useradd.c: Report failures to unlock files (stderr, syslog, and audit). But do not fail (continue). * src/useradd.c (open_files): Do not report to syslog & audit failures to lock or open the databases. This might be harmless, and the logs were not already informed that a change was requested. * src/usermod.c: It's not the account which is unlocked, but its password.
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fprintf (stderr,
_("%s: cannot open %s\n"),
Prog, pw_dbname ());
fail_exit (1);
}
if (spw_lock () == 0) {
* lib/groupio.c, lib/groupio.h, lib/pwio.c, lib/pwio.h, lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h: Added *_dbname() functions to retrieve the name of the databases. * lib/groupio.c, lib/groupio.h, lib/pwio.c, lib/pwio.h, lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h: *_name() functions renamed *setname(). * src/grpck.c, src/pwck.c: Likewise. * lib/groupio.h, lib/pwio.h, lib/sgroupio.h, lib/shadowio.h: Added the name of the arguments to the prototypes. * src/chage, src/chfn.c, src/chgpasswd.c, src/chpasswd.c, src/chsh.c, src/gpasswd.c, src/groupadd.c, src/groupdel.c, src/groupmod.c, src/grpck.c, src/grpconv.c, src/grpunconv.c, src/newusers.c, src/passwd.c, src/pwck.c, src/pwconv.c, src/pwunconv.c, src/useradd.c, src/userdel.c, src/usermod.c: Harmonize the erro & syslog messages in case of failure of the *_lock(), *_open(), *_close(), *_unlock(), *_remove() functions. * src/chgpasswd.c, src/chpasswd.c, src/usermod.c: Avoid capitalized messages. * src/chpasswd.c, src/useradd.c, src/usermod.c: Harmonize messages in case of inexistent entries. * src/usermod.c: Harmonize messages in case of already existing entries. * src/newusers.c, src/useradd.c: Simplify PAM error handling. * src/useradd.c: Report failures to unlock files (stderr, syslog, and audit). But do not fail (continue). * src/useradd.c (open_files): Do not report to syslog & audit failures to lock or open the databases. This might be harmless, and the logs were not already informed that a change was requested. * src/usermod.c: It's not the account which is unlocked, but its password.
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fprintf (stderr,
_("%s: cannot lock %s; try again later.\n"),
* lib/groupio.c, lib/groupio.h, lib/pwio.c, lib/pwio.h, lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h: Added *_dbname() functions to retrieve the name of the databases. * lib/groupio.c, lib/groupio.h, lib/pwio.c, lib/pwio.h, lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h: *_name() functions renamed *setname(). * src/grpck.c, src/pwck.c: Likewise. * lib/groupio.h, lib/pwio.h, lib/sgroupio.h, lib/shadowio.h: Added the name of the arguments to the prototypes. * src/chage, src/chfn.c, src/chgpasswd.c, src/chpasswd.c, src/chsh.c, src/gpasswd.c, src/groupadd.c, src/groupdel.c, src/groupmod.c, src/grpck.c, src/grpconv.c, src/grpunconv.c, src/newusers.c, src/passwd.c, src/pwck.c, src/pwconv.c, src/pwunconv.c, src/useradd.c, src/userdel.c, src/usermod.c: Harmonize the erro & syslog messages in case of failure of the *_lock(), *_open(), *_close(), *_unlock(), *_remove() functions. * src/chgpasswd.c, src/chpasswd.c, src/usermod.c: Avoid capitalized messages. * src/chpasswd.c, src/useradd.c, src/usermod.c: Harmonize messages in case of inexistent entries. * src/usermod.c: Harmonize messages in case of already existing entries. * src/newusers.c, src/useradd.c: Simplify PAM error handling. * src/useradd.c: Report failures to unlock files (stderr, syslog, and audit). But do not fail (continue). * src/useradd.c (open_files): Do not report to syslog & audit failures to lock or open the databases. This might be harmless, and the logs were not already informed that a change was requested. * src/usermod.c: It's not the account which is unlocked, but its password.
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Prog, spw_dbname ());
fail_exit (5);
}
spw_locked = true;
if (spw_open (O_RDONLY) == 0) {
* lib/groupio.c, lib/groupio.h, lib/pwio.c, lib/pwio.h, lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h: Added *_dbname() functions to retrieve the name of the databases. * lib/groupio.c, lib/groupio.h, lib/pwio.c, lib/pwio.h, lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h: *_name() functions renamed *setname(). * src/grpck.c, src/pwck.c: Likewise. * lib/groupio.h, lib/pwio.h, lib/sgroupio.h, lib/shadowio.h: Added the name of the arguments to the prototypes. * src/chage, src/chfn.c, src/chgpasswd.c, src/chpasswd.c, src/chsh.c, src/gpasswd.c, src/groupadd.c, src/groupdel.c, src/groupmod.c, src/grpck.c, src/grpconv.c, src/grpunconv.c, src/newusers.c, src/passwd.c, src/pwck.c, src/pwconv.c, src/pwunconv.c, src/useradd.c, src/userdel.c, src/usermod.c: Harmonize the erro & syslog messages in case of failure of the *_lock(), *_open(), *_close(), *_unlock(), *_remove() functions. * src/chgpasswd.c, src/chpasswd.c, src/usermod.c: Avoid capitalized messages. * src/chpasswd.c, src/useradd.c, src/usermod.c: Harmonize messages in case of inexistent entries. * src/usermod.c: Harmonize messages in case of already existing entries. * src/newusers.c, src/useradd.c: Simplify PAM error handling. * src/useradd.c: Report failures to unlock files (stderr, syslog, and audit). But do not fail (continue). * src/useradd.c (open_files): Do not report to syslog & audit failures to lock or open the databases. This might be harmless, and the logs were not already informed that a change was requested. * src/usermod.c: It's not the account which is unlocked, but its password.
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fprintf (stderr,
_("%s: cannot open %s\n"),
Prog, spw_dbname ());
fail_exit (1);
}
(void) pw_rewind ();
while ((pw = pw_next ()) != NULL) {
spwd = spw_locate (pw->pw_name);
if (NULL == spwd) {
continue;
}
pwent = *pw;
/*
* Update password if non-shadow is "x".
*/
if (strcmp (pw->pw_passwd, SHADOW_PASSWD_STRING) == 0) {
pwent.pw_passwd = spwd->sp_pwdp;
}
/*
* Password aging works differently in the two different
* systems. With shadow password files you apparently must
* have some aging information. The maxweeks or minweeks
* may not map exactly. In pwconv we set max == 10000,
* which is about 30 years. Here we have to undo that
* kludge. So, if maxdays == 10000, no aging information is
* put into the new file. Otherwise, the days are converted
* to weeks and so on.
*/
if (pw_update (&pwent) == 0) {
fprintf (stderr,
_("%s: failed to prepare the new %s entry '%s'\n"),
Prog, pw_dbname (), pwent.pw_name);
fail_exit (3);
}
}
(void) spw_close (); /* was only open O_RDONLY */
if (pw_close () == 0) {
* lib/groupio.c, lib/groupio.h, lib/pwio.c, lib/pwio.h, lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h: Added *_dbname() functions to retrieve the name of the databases. * lib/groupio.c, lib/groupio.h, lib/pwio.c, lib/pwio.h, lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h: *_name() functions renamed *setname(). * src/grpck.c, src/pwck.c: Likewise. * lib/groupio.h, lib/pwio.h, lib/sgroupio.h, lib/shadowio.h: Added the name of the arguments to the prototypes. * src/chage, src/chfn.c, src/chgpasswd.c, src/chpasswd.c, src/chsh.c, src/gpasswd.c, src/groupadd.c, src/groupdel.c, src/groupmod.c, src/grpck.c, src/grpconv.c, src/grpunconv.c, src/newusers.c, src/passwd.c, src/pwck.c, src/pwconv.c, src/pwunconv.c, src/useradd.c, src/userdel.c, src/usermod.c: Harmonize the erro & syslog messages in case of failure of the *_lock(), *_open(), *_close(), *_unlock(), *_remove() functions. * src/chgpasswd.c, src/chpasswd.c, src/usermod.c: Avoid capitalized messages. * src/chpasswd.c, src/useradd.c, src/usermod.c: Harmonize messages in case of inexistent entries. * src/usermod.c: Harmonize messages in case of already existing entries. * src/newusers.c, src/useradd.c: Simplify PAM error handling. * src/useradd.c: Report failures to unlock files (stderr, syslog, and audit). But do not fail (continue). * src/useradd.c (open_files): Do not report to syslog & audit failures to lock or open the databases. This might be harmless, and the logs were not already informed that a change was requested. * src/usermod.c: It's not the account which is unlocked, but its password.
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fprintf (stderr,
_("%s: failure while writing changes to %s\n"),
Prog, pw_dbname ());
SYSLOG ((LOG_ERR, "failure while writing changes to %s", pw_dbname ()));
fail_exit (3);
}
if (unlink (SHADOW) != 0) {
fprintf (stderr,
* lib/groupio.c, lib/groupio.h, lib/pwio.c, lib/pwio.h, lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h: Added *_dbname() functions to retrieve the name of the databases. * lib/groupio.c, lib/groupio.h, lib/pwio.c, lib/pwio.h, lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h: *_name() functions renamed *setname(). * src/grpck.c, src/pwck.c: Likewise. * lib/groupio.h, lib/pwio.h, lib/sgroupio.h, lib/shadowio.h: Added the name of the arguments to the prototypes. * src/chage, src/chfn.c, src/chgpasswd.c, src/chpasswd.c, src/chsh.c, src/gpasswd.c, src/groupadd.c, src/groupdel.c, src/groupmod.c, src/grpck.c, src/grpconv.c, src/grpunconv.c, src/newusers.c, src/passwd.c, src/pwck.c, src/pwconv.c, src/pwunconv.c, src/useradd.c, src/userdel.c, src/usermod.c: Harmonize the erro & syslog messages in case of failure of the *_lock(), *_open(), *_close(), *_unlock(), *_remove() functions. * src/chgpasswd.c, src/chpasswd.c, src/usermod.c: Avoid capitalized messages. * src/chpasswd.c, src/useradd.c, src/usermod.c: Harmonize messages in case of inexistent entries. * src/usermod.c: Harmonize messages in case of already existing entries. * src/newusers.c, src/useradd.c: Simplify PAM error handling. * src/useradd.c: Report failures to unlock files (stderr, syslog, and audit). But do not fail (continue). * src/useradd.c (open_files): Do not report to syslog & audit failures to lock or open the databases. This might be harmless, and the logs were not already informed that a change was requested. * src/usermod.c: It's not the account which is unlocked, but its password.
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_("%s: cannot delete %s\n"), Prog, SHADOW);
SYSLOG ((LOG_ERR, "cannot delete %s", SHADOW));
fail_exit (3);
}
if (spw_unlock () == 0) {
fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, spw_dbname ());
SYSLOG ((LOG_ERR, "failed to unlock %s", spw_dbname ()));
/* continue */
}
if (pw_unlock () == 0) {
fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, pw_dbname ());
SYSLOG ((LOG_ERR, "failed to unlock %s", pw_dbname ()));
/* continue */
}
nscd_flush_cache ("passwd");
Flush sssd caches in addition to nscd caches Some distributions, notably Fedora, have the following order of nsswitch modules by default: passwd: sss files group: sss files The advantage of serving local users through SSSD is that the nss_sss module has a fast mmapped-cache that speeds up NSS lookups compared to accessing the disk an opening the files on each NSS request. Traditionally, this has been done with the help of nscd, but using nscd in parallel with sssd is cumbersome, as both SSSD and nscd use their own independent caching, so using nscd in setups where sssd is also serving users from some remote domain (LDAP, AD, ...) can result in a bit of unpredictability. More details about why Fedora chose to use sss before files can be found on e.g.: https://fedoraproject.org//wiki/Changes/SSSDCacheForLocalUsers or: https://docs.pagure.org/SSSD.sssd/design_pages/files_provider.html Now, even though sssd watches the passwd and group files with the help of inotify, there can still be a small window where someone requests a user or a group, finds that it doesn't exist, adds the entry and checks again. Without some support in shadow-utils that would explicitly drop the sssd caches, the inotify watch can fire a little late, so a combination of commands like this: getent passwd user || useradd user; getent passwd user can result in the second getent passwd not finding the newly added user as the racy behaviour might still return the cached negative hit from the first getent passwd. This patch more or less copies the already existing support that shadow-utils had for dropping nscd caches, except using the "sss_cache" tool that sssd ships.
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sssd_flush_cache (SSSD_DB_PASSWD);
return 0;
}