busybox/loginutils/addgroup.c
Denis Vlasenko 829bbd3b57 *: unify concurrent-safe update of /etc/{passwd,group,[g]shadow}
by Tito (farmatito AT tiscali.it)

function                                             old     new   delta
update_passwd                                        743    1171    +428
bb_perror_nomsg                                        -       9      +9
find_main                                            436     444      +8
passwd_main                                         1023    1027      +4
nameval                                              202     206      +4
chpasswd_main                                        315     319      +4
bb__parsespent                                       119     117      -2
adduser_main                                         654     650      -4
addgroup_main                                        345     341      -4
sv_main                                             1228    1222      -6
deluser_main                                         173     160     -13
bb_internal_putpwent                                  69       -     -69
add_user_to_group                                    231       -    -231
del_line_matching                                    460      31    -429
------------------------------------------------------------------------------
(add/remove: 1/2 grow/shrink: 5/6 up/down: 457/-758)         Total: -301 bytes
2009-04-14 00:51:05 +00:00

134 lines
3.3 KiB
C

/* vi: set sw=4 ts=4: */
/*
* addgroup - add groups to /etc/group and /etc/gshadow
*
* Copyright (C) 1999 by Lineo, inc. and John Beppu
* Copyright (C) 1999,2000,2001 by John Beppu <beppu@codepoet.org>
* Copyright (C) 2007 by Tito Ragusa <farmatito@tiscali.it>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*
*/
#include "libbb.h"
static void xgroup_study(struct group *g)
{
/* Make sure gr_name is unused */
if (getgrnam(g->gr_name)) {
goto error;
}
/* Check if the desired gid is free
* or find the first free one */
while (1) {
if (!getgrgid(g->gr_gid)) {
return; /* found free group: return */
}
if (option_mask32) {
/* -g N, cannot pick gid other than N: error */
g->gr_name = itoa(g->gr_gid);
goto error;
}
g->gr_gid++;
if (g->gr_gid <= 0) {
/* overflowed: error */
bb_error_msg_and_die("no gids left");
}
}
error:
/* exit */
bb_error_msg_and_die("group %s already exists", g->gr_name);
}
/* append a new user to the passwd file */
static void new_group(char *group, gid_t gid)
{
struct group gr;
char *p;
/* make sure gid and group haven't already been allocated */
gr.gr_gid = gid;
gr.gr_name = group;
xgroup_study(&gr);
/* add entry to group */
p = xasprintf("x:%u:", gr.gr_gid);
if (update_passwd(bb_path_group_file, group, p, NULL) < 0)
exit(EXIT_FAILURE);
if (ENABLE_FEATURE_CLEAN_UP)
free(p);
#if ENABLE_FEATURE_SHADOWPASSWDS
/* Ignore errors: if file is missing we suppose admin doesn't want it */
update_passwd(bb_path_gshadow_file, group, "!::", NULL);
#endif
}
/*
* addgroup will take a login_name as its first parameter.
*
* gid can be customized via command-line parameters.
* If called with two non-option arguments, addgroup
* will add an existing user to an existing group.
*/
int addgroup_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int addgroup_main(int argc UNUSED_PARAM, char **argv)
{
char *group;
gid_t gid = 0;
/* need to be root */
if (geteuid()) {
bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
}
/* Syntax:
* addgroup group
* addgroup -g num group
* addgroup user group
* Check for min, max and missing args */
opt_complementary = "-1:?2";
if (getopt32(argv, "g:", &group)) {
gid = xatoul_range(group, 0, ((unsigned long)(gid_t)ULONG_MAX) >> 1);
}
/* move past the commandline options */
argv += optind;
//argc -= optind;
#if ENABLE_FEATURE_ADDUSER_TO_GROUP
if (argv[1]) {
struct group *gr;
if (option_mask32) {
/* -g was there, but "addgroup -g num user group"
* is a no-no */
bb_show_usage();
}
/* check if group and user exist */
xuname2uid(argv[0]); /* unknown user: exit */
gr = xgetgrnam(argv[1]); /* unknown group: exit */
/* check if user is already in this group */
for (; *(gr->gr_mem) != NULL; (gr->gr_mem)++) {
if (!strcmp(argv[0], *(gr->gr_mem))) {
/* user is already in group: do nothing */
return EXIT_SUCCESS;
}
}
if (update_passwd(bb_path_group_file, argv[1], NULL, argv[0]) < 0) {
return EXIT_FAILURE;
}
# if ENABLE_FEATURE_SHADOWPASSWDS
update_passwd(bb_path_gshadow_file, argv[1], NULL, argv[0]);
# endif
} else
#endif /* ENABLE_FEATURE_ADDUSER_TO_GROUP */
{
die_if_bad_username(argv[0]);
new_group(argv[0], gid);
}
/* Reached only on success */
return EXIT_SUCCESS;
}