blob: a7c52273beb75b0e2b5e571c43d41e4428efa949
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * addgroup - add groups to /etc/group and /etc/gshadow |
4 | * |
5 | * Copyright (C) 1999 by Lineo, inc. and John Beppu |
6 | * Copyright (C) 1999,2000,2001 by John Beppu <beppu@codepoet.org> |
7 | * Copyright (C) 2007 by Tito Ragusa <farmatito@tiscali.it> |
8 | * |
9 | * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
10 | * |
11 | */ |
12 | //config:config ADDGROUP |
13 | //config: bool "addgroup" |
14 | //config: default y |
15 | //config: help |
16 | //config: Utility for creating a new group account. |
17 | //config: |
18 | //config:config FEATURE_ADDGROUP_LONG_OPTIONS |
19 | //config: bool "Enable long options" |
20 | //config: default y |
21 | //config: depends on ADDGROUP && LONG_OPTS |
22 | //config: help |
23 | //config: Support long options for the addgroup applet. |
24 | //config: |
25 | //config:config FEATURE_ADDUSER_TO_GROUP |
26 | //config: bool "Support for adding users to groups" |
27 | //config: default y |
28 | //config: depends on ADDGROUP |
29 | //config: help |
30 | //config: If called with two non-option arguments, |
31 | //config: addgroup will add an existing user to an |
32 | //config: existing group. |
33 | |
34 | //applet:IF_ADDGROUP(APPLET(addgroup, BB_DIR_USR_SBIN, BB_SUID_DROP)) |
35 | |
36 | //kbuild:lib-$(CONFIG_ADDGROUP) += addgroup.o |
37 | |
38 | //usage:#define addgroup_trivial_usage |
39 | //usage: "[-g GID] [-S] " IF_FEATURE_ADDUSER_TO_GROUP("[USER] ") "GROUP" |
40 | //usage:#define addgroup_full_usage "\n\n" |
41 | //usage: "Add a group" IF_FEATURE_ADDUSER_TO_GROUP(" or add a user to a group") "\n" |
42 | //usage: "\n -g GID Group id" |
43 | //usage: "\n -S Create a system group" |
44 | |
45 | #include "libbb.h" |
46 | |
47 | #if CONFIG_LAST_SYSTEM_ID < CONFIG_FIRST_SYSTEM_ID |
48 | #error Bad LAST_SYSTEM_ID or FIRST_SYSTEM_ID in .config |
49 | #endif |
50 | #if CONFIG_LAST_ID < CONFIG_LAST_SYSTEM_ID |
51 | #error Bad LAST_ID or LAST_SYSTEM_ID in .config |
52 | #endif |
53 | |
54 | #define OPT_GID (1 << 0) |
55 | #define OPT_SYSTEM_ACCOUNT (1 << 1) |
56 | |
57 | static void xgroup_study(struct group *g) |
58 | { |
59 | unsigned max = CONFIG_LAST_ID; |
60 | |
61 | /* Make sure gr_name is unused */ |
62 | if (getgrnam(g->gr_name)) { |
63 | bb_error_msg_and_die("%s '%s' in use", "group", g->gr_name); |
64 | /* these format strings are reused in adduser and addgroup */ |
65 | } |
66 | |
67 | /* if a specific gid is requested, the --system switch and */ |
68 | /* min and max values are overridden, and the range of valid */ |
69 | /* gid values is set to [0, INT_MAX] */ |
70 | if (!(option_mask32 & OPT_GID)) { |
71 | if (option_mask32 & OPT_SYSTEM_ACCOUNT) { |
72 | g->gr_gid = CONFIG_FIRST_SYSTEM_ID; |
73 | max = CONFIG_LAST_SYSTEM_ID; |
74 | } else { |
75 | g->gr_gid = CONFIG_LAST_SYSTEM_ID + 1; |
76 | } |
77 | } |
78 | /* Check if the desired gid is free |
79 | * or find the first free one */ |
80 | while (1) { |
81 | if (!getgrgid(g->gr_gid)) { |
82 | return; /* found free group: return */ |
83 | } |
84 | if (option_mask32 & OPT_GID) { |
85 | /* -g N, cannot pick gid other than N: error */ |
86 | bb_error_msg_and_die("%s '%s' in use", "gid", itoa(g->gr_gid)); |
87 | /* this format strings is reused in adduser and addgroup */ |
88 | } |
89 | if (g->gr_gid == max) { |
90 | /* overflowed: error */ |
91 | bb_error_msg_and_die("no %cids left", 'g'); |
92 | /* this format string is reused in adduser and addgroup */ |
93 | } |
94 | g->gr_gid++; |
95 | } |
96 | } |
97 | |
98 | /* append a new user to the passwd file */ |
99 | static void new_group(char *group, gid_t gid) |
100 | { |
101 | struct group gr; |
102 | char *p; |
103 | |
104 | /* make sure gid and group haven't already been allocated */ |
105 | gr.gr_gid = gid; |
106 | gr.gr_name = group; |
107 | xgroup_study(&gr); |
108 | |
109 | /* add entry to group */ |
110 | p = xasprintf("x:%u:", (unsigned) gr.gr_gid); |
111 | if (update_passwd(bb_path_group_file, group, p, NULL) < 0) |
112 | exit(EXIT_FAILURE); |
113 | if (ENABLE_FEATURE_CLEAN_UP) |
114 | free(p); |
115 | #if ENABLE_FEATURE_SHADOWPASSWDS |
116 | /* /etc/gshadow fields: |
117 | * 1. Group name. |
118 | * 2. Encrypted password. |
119 | * If set, non-members of the group can join the group |
120 | * by typing the password for that group using the newgrp command. |
121 | * If the value is of this field ! then no user is allowed |
122 | * to access the group using the newgrp command. A value of !! |
123 | * is treated the same as a value of ! only it indicates |
124 | * that a password has never been set before. If the value is null, |
125 | * only group members can log into the group. |
126 | * 3. Group administrators (comma delimited list). |
127 | * Group members listed here can add or remove group members |
128 | * using the gpasswd command. |
129 | * 4. Group members (comma delimited list). |
130 | */ |
131 | /* Ignore errors: if file is missing we assume admin doesn't want it */ |
132 | update_passwd(bb_path_gshadow_file, group, "!::", NULL); |
133 | #endif |
134 | } |
135 | |
136 | #if ENABLE_FEATURE_ADDGROUP_LONG_OPTIONS |
137 | static const char addgroup_longopts[] ALIGN1 = |
138 | "gid\0" Required_argument "g" |
139 | "system\0" No_argument "S" |
140 | ; |
141 | #endif |
142 | |
143 | /* |
144 | * addgroup will take a login_name as its first parameter. |
145 | * |
146 | * gid can be customized via command-line parameters. |
147 | * If called with two non-option arguments, addgroup |
148 | * will add an existing user to an existing group. |
149 | */ |
150 | int addgroup_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
151 | int addgroup_main(int argc UNUSED_PARAM, char **argv) |
152 | { |
153 | unsigned opts; |
154 | const char *gid = "0"; |
155 | |
156 | /* need to be root */ |
157 | if (geteuid()) { |
158 | bb_error_msg_and_die("%s", bb_msg_perm_denied_are_you_root); |
159 | } |
160 | #if ENABLE_FEATURE_ADDGROUP_LONG_OPTIONS |
161 | applet_long_options = addgroup_longopts; |
162 | #endif |
163 | /* Syntax: |
164 | * addgroup group |
165 | * addgroup -g num group |
166 | * addgroup user group |
167 | * Check for min, max and missing args */ |
168 | opt_complementary = "-1:?2"; |
169 | opts = getopt32(argv, "g:S", &gid); |
170 | /* move past the commandline options */ |
171 | argv += optind; |
172 | //argc -= optind; |
173 | |
174 | #if ENABLE_FEATURE_ADDUSER_TO_GROUP |
175 | if (argv[1]) { |
176 | struct group *gr; |
177 | |
178 | if (opts & OPT_GID) { |
179 | /* -g was there, but "addgroup -g num user group" |
180 | * is a no-no */ |
181 | bb_show_usage(); |
182 | } |
183 | |
184 | /* check if group and user exist */ |
185 | xuname2uid(argv[0]); /* unknown user: exit */ |
186 | gr = xgetgrnam(argv[1]); /* unknown group: exit */ |
187 | /* check if user is already in this group */ |
188 | for (; *(gr->gr_mem) != NULL; (gr->gr_mem)++) { |
189 | if (strcmp(argv[0], *(gr->gr_mem)) == 0) { |
190 | /* user is already in group: do nothing */ |
191 | return EXIT_SUCCESS; |
192 | } |
193 | } |
194 | if (update_passwd(bb_path_group_file, argv[1], NULL, argv[0]) < 0) { |
195 | return EXIT_FAILURE; |
196 | } |
197 | # if ENABLE_FEATURE_SHADOWPASSWDS |
198 | update_passwd(bb_path_gshadow_file, argv[1], NULL, argv[0]); |
199 | # endif |
200 | } else |
201 | #endif /* ENABLE_FEATURE_ADDUSER_TO_GROUP */ |
202 | { |
203 | die_if_bad_username(argv[0]); |
204 | new_group(argv[0], xatou_range(gid, 0, CONFIG_LAST_ID)); |
205 | } |
206 | /* Reached only on success */ |
207 | return EXIT_SUCCESS; |
208 | } |
209 |