aboutsummaryrefslogtreecommitdiff
path: root/loginutils/addgroup.c
blob: 5a0cf3ffff30a16feeb113cad6b08792961098c4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
/* 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;
}