shadow/src/groupadd.c
Serge Hallyn 342c934a35 add -U option to groupadd and groupmod
Add a -U option which adds new usernames as members.  For groupmod,
also add -a (append), without which existing members are removed.

Closes #265
2020-08-09 22:11:33 -05:00

653 lines
17 KiB
C

/*
* Copyright (c) 1991 - 1993, 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 <ctype.h>
#include <fcntl.h>
#include <getopt.h>
#include <grp.h>
#include <stdio.h>
#include <sys/types.h>
#ifdef ACCT_TOOLS_SETUID
#ifdef USE_PAM
#include "pam_defs.h"
#include <pwd.h>
#endif /* USE_PAM */
#endif /* ACCT_TOOLS_SETUID */
#include "chkname.h"
#include "defines.h"
#include "getdef.h"
#include "groupio.h"
#include "nscd.h"
#include "sssd.h"
#include "prototypes.h"
#ifdef SHADOWGRP
#include "sgroupio.h"
#endif
/*
* exit status values
*/
/*@-exitarg@*/
#define E_SUCCESS 0 /* success */
#define E_USAGE 2 /* invalid command syntax */
#define E_BAD_ARG 3 /* invalid argument to option */
#define E_GID_IN_USE 4 /* gid not unique (when -o not used) */
#define E_NAME_IN_USE 9 /* group name not unique */
#define E_GRP_UPDATE 10 /* can't update group file */
/*
* Global variables
*/
const char *Prog;
static /*@null@*/char *group_name;
static gid_t group_id;
static /*@null@*/char *group_passwd;
static /*@null@*/char *empty_list = NULL;
static const char *prefix = "";
static char *user_list;
static bool oflg = false; /* permit non-unique group ID to be specified with -g */
static bool gflg = false; /* ID value for the new group */
static bool fflg = false; /* if group already exists, do nothing and exit(0) */
static bool rflg = false; /* create a system account */
static bool pflg = false; /* new encrypted password */
#ifdef SHADOWGRP
static bool is_shadow_grp;
#endif
/* local function prototypes */
static /*@noreturn@*/void usage (int status);
static void new_grent (struct group *grent);
#ifdef SHADOWGRP
static void new_sgent (struct sgrp *sgent);
#endif
static void grp_update (void);
static void check_new_name (void);
static void close_files (void);
static void open_files (void);
static void process_flags (int argc, char **argv);
static void check_flags (void);
static void check_perms (void);
/*
* usage - display usage message and exit
*/
static /*@noreturn@*/void usage (int status)
{
FILE *usageout = (E_SUCCESS != status) ? stderr : stdout;
(void) fprintf (usageout,
_("Usage: %s [options] GROUP\n"
"\n"
"Options:\n"),
Prog);
(void) fputs (_(" -f, --force exit successfully if the group already exists,\n"
" and cancel -g if the GID is already used\n"), usageout);
(void) fputs (_(" -g, --gid GID use GID for the new group\n"), usageout);
(void) fputs (_(" -h, --help display this help message and exit\n"), usageout);
(void) fputs (_(" -K, --key KEY=VALUE override /etc/login.defs defaults\n"), usageout);
(void) fputs (_(" -o, --non-unique allow to create groups with duplicate\n"
" (non-unique) GID\n"), usageout);
(void) fputs (_(" -p, --password PASSWORD use this encrypted password for the new group\n"), usageout);
(void) fputs (_(" -r, --system create a system account\n"), usageout);
(void) fputs (_(" -R, --root CHROOT_DIR directory to chroot into\n"), usageout);
(void) fputs (_(" -P, --prefix PREFIX_DI directory prefix\n"), usageout);
(void) fputs (_(" -U, --users USERS list of user members of this group\n"), usageout);
(void) fputs ("\n", usageout);
exit (status);
}
/*
* new_grent - initialize the values in a group file entry
*
* new_grent() takes all of the values that have been entered and fills
* in a (struct group) with them.
*/
static void new_grent (struct group *grent)
{
memzero (grent, sizeof *grent);
grent->gr_name = group_name;
if (pflg) {
grent->gr_passwd = group_passwd;
} else {
grent->gr_passwd = SHADOW_PASSWD_STRING; /* XXX warning: const */
}
grent->gr_gid = group_id;
grent->gr_mem = &empty_list;
}
#ifdef SHADOWGRP
/*
* new_sgent - initialize the values in a shadow group file entry
*
* new_sgent() takes all of the values that have been entered and fills
* in a (struct sgrp) with them.
*/
static void new_sgent (struct sgrp *sgent)
{
memzero (sgent, sizeof *sgent);
sgent->sg_name = group_name;
if (pflg) {
sgent->sg_passwd = group_passwd;
} else {
sgent->sg_passwd = "!"; /* XXX warning: const */
}
sgent->sg_adm = &empty_list;
sgent->sg_mem = &empty_list;
}
#endif /* SHADOWGRP */
/*
* grp_update - add new group file entries
*
* grp_update() writes the new records to the group files.
*/
static void grp_update (void)
{
struct group grp;
#ifdef SHADOWGRP
struct sgrp sgrp;
#endif /* SHADOWGRP */
/*
* To add the group, we need to update /etc/group.
* Make sure failures will be reported.
*/
add_cleanup (cleanup_report_add_group_group, group_name);
#ifdef SHADOWGRP
if (is_shadow_grp) {
/* We also need to update /etc/gshadow */
add_cleanup (cleanup_report_add_group_gshadow, group_name);
}
#endif
/*
* Create the initial entries for this new group.
*/
new_grent (&grp);
#ifdef SHADOWGRP
new_sgent (&sgrp);
if (is_shadow_grp && pflg) {
grp.gr_passwd = SHADOW_PASSWD_STRING; /* XXX warning: const */
}
#endif /* SHADOWGRP */
if (user_list) {
char *token;
token = strtok(user_list, ",");
while (token) {
if (prefix_getpwnam (token) == NULL) {
fprintf (stderr, _("Invalid member username %s\n"), token);
exit (E_GRP_UPDATE);
}
grp.gr_mem = add_list(grp.gr_mem, token);
token = strtok(NULL, ",");
}
}
/*
* Write out the new group file entry.
*/
if (gr_update (&grp) == 0) {
fprintf (stderr,
_("%s: failed to prepare the new %s entry '%s'\n"),
Prog, gr_dbname (), grp.gr_name);
exit (E_GRP_UPDATE);
}
#ifdef SHADOWGRP
/*
* Write out the new shadow group entries as well.
*/
if (is_shadow_grp && (sgr_update (&sgrp) == 0)) {
fprintf (stderr,
_("%s: failed to prepare the new %s entry '%s'\n"),
Prog, sgr_dbname (), sgrp.sg_name);
exit (E_GRP_UPDATE);
}
#endif /* SHADOWGRP */
}
/*
* check_new_name - check the new name for validity
*
* check_new_name() insures that the new name doesn't contain any
* illegal characters.
*/
static void check_new_name (void)
{
if (is_valid_group_name (group_name)) {
return;
}
/*
* All invalid group names land here.
*/
fprintf (stderr, _("%s: '%s' is not a valid group name\n"),
Prog, group_name);
exit (E_BAD_ARG);
}
/*
* close_files - close all of the files that were opened
*
* close_files() closes all of the files that were opened for this new
* group. This causes any modified entries to be written out.
*/
static void close_files (void)
{
/* First, write the changes in the regular group database */
if (gr_close () == 0) {
fprintf (stderr,
_("%s: failure while writing changes to %s\n"),
Prog, gr_dbname ());
exit (E_GRP_UPDATE);
}
#ifdef WITH_AUDIT
audit_logger (AUDIT_ADD_GROUP, Prog,
"adding group to /etc/group",
group_name, (unsigned int) group_id,
SHADOW_AUDIT_SUCCESS);
#endif
SYSLOG ((LOG_INFO, "group added to %s: name=%s, GID=%u",
gr_dbname (), group_name, (unsigned int) group_id));
del_cleanup (cleanup_report_add_group_group);
cleanup_unlock_group (NULL);
del_cleanup (cleanup_unlock_group);
/* Now, write the changes in the shadow database */
#ifdef SHADOWGRP
if (is_shadow_grp) {
if (sgr_close () == 0) {
fprintf (stderr,
_("%s: failure while writing changes to %s\n"),
Prog, sgr_dbname ());
exit (E_GRP_UPDATE);
}
#ifdef WITH_AUDIT
audit_logger (AUDIT_ADD_GROUP, Prog,
"adding group to /etc/gshadow",
group_name, (unsigned int) group_id,
SHADOW_AUDIT_SUCCESS);
#endif
SYSLOG ((LOG_INFO, "group added to %s: name=%s",
sgr_dbname (), group_name));
del_cleanup (cleanup_report_add_group_gshadow);
cleanup_unlock_gshadow (NULL);
del_cleanup (cleanup_unlock_gshadow);
}
#endif /* SHADOWGRP */
/* Report success at the system level */
#ifdef WITH_AUDIT
audit_logger (AUDIT_ADD_GROUP, Prog,
"",
group_name, (unsigned int) group_id,
SHADOW_AUDIT_SUCCESS);
#endif
SYSLOG ((LOG_INFO, "new group: name=%s, GID=%u",
group_name, (unsigned int) group_id));
del_cleanup (cleanup_report_add_group);
}
/*
* open_files - lock and open the group files
*
* open_files() opens the two group files.
*/
static void open_files (void)
{
/* First, lock the databases */
if (gr_lock () == 0) {
fprintf (stderr,
_("%s: cannot lock %s; try again later.\n"),
Prog, gr_dbname ());
exit (E_GRP_UPDATE);
}
add_cleanup (cleanup_unlock_group, NULL);
#ifdef SHADOWGRP
if (is_shadow_grp) {
if (sgr_lock () == 0) {
fprintf (stderr,
_("%s: cannot lock %s; try again later.\n"),
Prog, sgr_dbname ());
exit (E_GRP_UPDATE);
}
add_cleanup (cleanup_unlock_gshadow, NULL);
}
#endif /* SHADOWGRP */
/*
* Now if the group is not added, it's our fault.
* Make sure failures will be reported.
*/
add_cleanup (cleanup_report_add_group, group_name);
/* And now open the databases */
if (gr_open (O_CREAT | O_RDWR) == 0) {
fprintf (stderr, _("%s: cannot open %s\n"), Prog, gr_dbname ());
SYSLOG ((LOG_WARN, "cannot open %s", gr_dbname ()));
exit (E_GRP_UPDATE);
}
#ifdef SHADOWGRP
if (is_shadow_grp) {
if (sgr_open (O_CREAT | O_RDWR) == 0) {
fprintf (stderr,
_("%s: cannot open %s\n"),
Prog, sgr_dbname ());
SYSLOG ((LOG_WARN, "cannot open %s", sgr_dbname ()));
exit (E_GRP_UPDATE);
}
}
#endif /* SHADOWGRP */
}
/*
* 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.
*/
char *cp;
int c;
static struct option long_options[] = {
{"force", no_argument, NULL, 'f'},
{"gid", required_argument, NULL, 'g'},
{"help", no_argument, NULL, 'h'},
{"key", required_argument, NULL, 'K'},
{"non-unique", no_argument, NULL, 'o'},
{"password", required_argument, NULL, 'p'},
{"system", no_argument, NULL, 'r'},
{"root", required_argument, NULL, 'R'},
{"prefix", required_argument, NULL, 'P'},
{"users", required_argument, NULL, 'U'},
{NULL, 0, NULL, '\0'}
};
while ((c = getopt_long (argc, argv, "fg:hK:op:rR:P:U:",
long_options, NULL)) != -1) {
switch (c) {
case 'f':
/*
* "force" - do nothing, just exit(0), if the
* specified group already exists. With -g, if
* specified gid already exists, choose another
* (unique) gid (turn off -g). Based on the RedHat's
* patch from shadow-utils-970616-9.
*/
fflg = true;
break;
case 'g':
gflg = true;
if ( (get_gid (optarg, &group_id) == 0)
|| (group_id == (gid_t)-1)) {
fprintf (stderr,
_("%s: invalid group ID '%s'\n"),
Prog, optarg);
exit (E_BAD_ARG);
}
break;
case 'h':
usage (E_SUCCESS);
/*@notreached@*/break;
case 'K':
/*
* override login.defs defaults (-K name=value)
* example: -K GID_MIN=100 -K GID_MAX=499
* note: -K GID_MIN=10,GID_MAX=499 doesn't work yet
*/
cp = strchr (optarg, '=');
if (NULL == cp) {
fprintf (stderr,
_("%s: -K requires KEY=VALUE\n"),
Prog);
exit (E_BAD_ARG);
}
/* terminate name, point to value */
*cp++ = '\0';
if (putdef_str (optarg, cp) < 0) {
exit (E_BAD_ARG);
}
break;
case 'o':
oflg = true;
break;
case 'p':
pflg = true;
group_passwd = optarg;
break;
case 'r':
rflg = true;
break;
case 'R': /* no-op, handled in process_root_flag () */
break;
case 'P': /* no-op, handled in process_prefix_flag () */
break;
case 'U':
user_list = optarg;
break;
default:
usage (E_USAGE);
}
}
/*
* Check the flags consistency
*/
if (optind != argc - 1) {
usage (E_USAGE);
}
group_name = argv[optind];
check_flags ();
}
/*
* check_flags - check flags and parameters consistency
*
* It will not return if an error is encountered.
*/
static void check_flags (void)
{
/* -o does not make sense without -g */
if (oflg && !gflg) {
usage (E_USAGE);
}
check_new_name ();
/*
* Check if the group already exist.
*/
/* local, no need for xgetgrnam */
if (prefix_getgrnam (group_name) != NULL) {
/* The group already exist */
if (fflg) {
/* OK, no need to do anything */
exit (E_SUCCESS);
}
fprintf (stderr,
_("%s: group '%s' already exists\n"),
Prog, group_name);
exit (E_NAME_IN_USE);
}
if (gflg && (prefix_getgrgid (group_id) != NULL)) {
/* A GID was specified, and a group already exist with that GID
* - either we will use this GID anyway (-o)
* - either we ignore the specified GID and
* we will use another one (-f)
* - either it is a failure
*/
if (oflg) {
/* Continue with this GID */
} else if (fflg) {
/* Turn off -g, we can use any GID */
gflg = false;
} else {
fprintf (stderr,
_("%s: GID '%lu' already exists\n"),
Prog, (unsigned long int) group_id);
exit (E_GID_IN_USE);
}
}
}
/*
* check_perms - check if the caller is allowed to add a group
*
* With PAM support, the setuid bit can be set on groupadd to allow
* non-root users to groups.
* Without PAM support, only users who can write in the group databases
* can add groups.
*
* It will not return if the user is not allowed.
*/
static void check_perms (void)
{
#ifdef ACCT_TOOLS_SETUID
#ifdef USE_PAM
pam_handle_t *pamh = NULL;
int retval;
struct passwd *pampw;
pampw = getpwuid (getuid ()); /* local, no need for xgetpwuid */
if (NULL == pampw) {
fprintf (stderr,
_("%s: Cannot determine your user name.\n"),
Prog);
exit (1);
}
retval = pam_start ("groupadd", pampw->pw_name, &conv, &pamh);
if (PAM_SUCCESS == retval) {
retval = pam_authenticate (pamh, 0);
}
if (PAM_SUCCESS == retval) {
retval = pam_acct_mgmt (pamh, 0);
}
if (PAM_SUCCESS != retval) {
fprintf (stderr, _("%s: PAM: %s\n"),
Prog, pam_strerror (pamh, retval));
SYSLOG((LOG_ERR, "%s", pam_strerror (pamh, retval)));
if (NULL != pamh) {
(void) pam_end (pamh, retval);
}
exit (1);
}
(void) pam_end (pamh, retval);
#endif /* USE_PAM */
#endif /* ACCT_TOOLS_SETUID */
}
/*
* main - groupadd command
*/
int main (int argc, char **argv)
{
/*
* Get my name so that I can use it to report errors.
*/
Prog = Basename (argv[0]);
(void) setlocale (LC_ALL, "");
(void) bindtextdomain (PACKAGE, LOCALEDIR);
(void) textdomain (PACKAGE);
process_root_flag ("-R", argc, argv);
prefix = process_prefix_flag ("-P", argc, argv);
OPENLOG ("groupadd");
#ifdef WITH_AUDIT
audit_help_open ();
#endif
if (atexit (do_cleanups) != 0) {
fprintf (stderr,
_("%s: Cannot setup cleanup service.\n"),
Prog);
exit (1);
}
/*
* Parse the command line options.
*/
process_flags (argc, argv);
check_perms ();
#ifdef SHADOWGRP
is_shadow_grp = sgr_file_present ();
#endif
/*
* Do the hard stuff - open the files, create the group entries,
* then close and update the files.
*/
open_files ();
if (!gflg) {
if (find_new_gid (rflg, &group_id, NULL) < 0) {
exit (E_GID_IN_USE);
}
}
grp_update ();
close_files ();
nscd_flush_cache ("group");
sssd_flush_cache (SSSD_DB_GROUP);
return E_SUCCESS;
}