1 /* vi: set sw=4 ts=4: */
3 * Mini id implementation for busybox
5 * Copyright (C) 2000 by Randolph Chung <tausq@debian.org>
6 * Copyright (C) 2008 by Tito Ragusa <farmatito@tiscali.it>
8 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
11 /* BB_AUDIT SUSv3 compliant. */
12 /* Hacked by Tito Ragusa (C) 2004 to handle usernames of whatever
13 * length and to be more similar to GNU id.
14 * -Z option support: by Yuichi Nakamura <ynakam@hitachisoft.jp>
15 * Added -G option Tito Ragusa (C) 2008 for SUSv3.
22 //config: id displays the current user and group ID names.
24 //config:config GROUPS
25 //config: bool "groups"
28 //config: Print the group names associated with current user id.
30 //kbuild:lib-$(CONFIG_GROUPS) += id.o
31 //kbuild:lib-$(CONFIG_ID) += id.o
33 //applet:IF_GROUPS(APPLET_NOEXEC(groups, id, BB_DIR_USR_BIN, BB_SUID_DROP, groups))
34 //applet:IF_ID( APPLET_NOEXEC(id, id, BB_DIR_USR_BIN, BB_SUID_DROP, id ))
36 //usage:#define id_trivial_usage
37 //usage: "[OPTIONS] [USER]"
38 //usage:#define id_full_usage "\n\n"
39 //usage: "Print information about USER or the current user\n"
41 //usage: "\n -Z Security context"
43 //usage: "\n -u User ID"
44 //usage: "\n -g Group ID"
45 //usage: "\n -G Supplementary group IDs"
46 //usage: "\n -n Print names instead of numbers"
47 //usage: "\n -r Print real ID instead of effective ID"
49 //usage:#define id_example_usage
51 //usage: "uid=1000(andersen) gid=1000(andersen)\n"
53 //usage:#define groups_trivial_usage
55 //usage:#define groups_full_usage "\n\n"
56 //usage: "Print the group memberships of USER or for the current process"
58 //usage:#define groups_example_usage
60 //usage: "andersen lp dialout cdrom floppy\n"
64 /* This is a NOEXEC applet. Be very careful! */
66 #if !ENABLE_USE_BB_PWD_GRP
67 #if defined(__UCLIBC_MAJOR__) && (__UCLIBC_MAJOR__ == 0)
68 #if (__UCLIBC_MINOR__ < 9) || (__UCLIBC_MINOR__ == 9 && __UCLIBC_SUBLEVEL__ < 30)
69 #error "Sorry, you need at least uClibc version 0.9.30 for id applet to build"
75 PRINT_REAL
= (1 << 0),
76 NAME_NOT_NUMBER
= (1 << 1),
78 JUST_GROUP
= (1 << 3),
79 JUST_ALL_GROUPS
= (1 << 4),
81 JUST_CONTEXT
= (1 << 5),
85 static int print_common(unsigned id
, const char *name
, const char *prefix
)
90 if (!(option_mask32
& NAME_NOT_NUMBER
) || !name
) {
93 if (!option_mask32
|| (option_mask32
& NAME_NOT_NUMBER
)) {
95 printf(option_mask32
? "%s" : "(%s)", name
);
97 /* Don't set error status flag in default mode */
100 bb_error_msg("unknown ID %u", id
);
108 static int print_group(gid_t id
, const char *prefix
)
110 return print_common(id
, gid2group(id
), prefix
);
113 static int print_user(uid_t id
, const char *prefix
)
115 return print_common(id
, uid2uname(id
), prefix
);
118 /* On error set *n < 0 and return >= 0
119 * If *n is too small, update it and return < 0
120 * (ok to trash groups[] in both cases)
121 * Otherwise fill in groups[] and return >= 0
123 static int get_groups(const char *username
, gid_t rgid
, gid_t
*groups
, int *n
)
128 /* If the user is a member of more than
129 * *n groups, then -1 is returned. Otherwise >= 0.
130 * (and no defined way of detecting errors?!) */
131 m
= getgrouplist(username
, rgid
, groups
, n
);
132 /* I guess *n < 0 might indicate error. Anyway,
133 * malloc'ing -1 bytes won't be good, so: */
139 *n
= getgroups(*n
, groups
);
143 if (errno
== EINVAL
) /* *n is too small? */
144 *n
= getgroups(0, groups
); /* get needed *n */
145 /* if *n >= 0, return -1 (got new *n), else return 0 (error): */
149 int id_main(int argc
, char **argv
) MAIN_EXTERNALLY_VISIBLE
;
150 int id_main(int argc UNUSED_PARAM
, char **argv
)
158 int status
= EXIT_SUCCESS
;
160 const char *username
;
162 security_context_t scontext
= NULL
;
165 if (ENABLE_GROUPS
&& (!ENABLE_ID
|| applet_name
[0] == 'g')) {
166 /* TODO: coreutils groups prepend "USER : " prefix,
167 * and accept many usernames. Example:
172 opt
= option_mask32
= getopt32(argv
, "") | JUST_ALL_GROUPS
| NAME_NOT_NUMBER
;
174 /* Don't allow -n -r -nr -ug -rug -nug -rnug -uZ -gZ -GZ*/
175 /* Don't allow more than one username */
176 opt_complementary
= "?1:u--g:g--u:G--u:u--G:g--G:G--g:r?ugG:n?ugG"
177 IF_SELINUX(":u--Z:Z--u:g--Z:Z--g:G--Z:Z--G");
178 opt
= getopt32(argv
, "rnugG" IF_SELINUX("Z"));
181 username
= argv
[optind
];
183 struct passwd
*p
= xgetpwnam(username
);
184 euid
= ruid
= p
->pw_uid
;
185 egid
= rgid
= p
->pw_gid
;
192 /* JUST_ALL_GROUPS ignores -r PRINT_REAL flag even if man page for */
193 /* id says: print the real ID instead of the effective ID, with -ugG */
194 /* in fact in this case egid is always printed if egid != rgid */
195 if (!opt
|| (opt
& JUST_ALL_GROUPS
)) {
201 status
|= print_user(ruid
, "uid=");
202 status
|= print_group(rgid
, " gid=");
204 status
|= print_user(euid
, " euid=");
206 status
|= print_group(egid
, " egid=");
208 /* JUST_ALL_GROUPS */
209 status
|= print_group(rgid
, NULL
);
211 status
|= print_group(egid
, " ");
213 /* We are supplying largish buffer, trying
214 * to not run get_groups() twice. That might be slow
215 * ("user database in remote SQL server" case) */
216 groups
= xmalloc(64 * sizeof(groups
[0]));
218 if (get_groups(username
, rgid
, groups
, &n
) < 0) {
219 /* Need bigger buffer after all */
220 groups
= xrealloc(groups
, n
* sizeof(groups
[0]));
221 get_groups(username
, rgid
, groups
, &n
);
226 for (i
= 0; i
< n
; i
++) {
227 if (opt
&& (groups
[i
] == rgid
|| groups
[i
] == egid
))
229 status
|= print_group(groups
[i
], opt
? " " : prefix
);
232 } else if (n
< 0) { /* error in get_groups() */
234 bb_error_msg_and_die("can't get groups");
237 if (ENABLE_FEATURE_CLEAN_UP
)
240 if (is_selinux_enabled()) {
241 if (getcon(&scontext
) == 0)
242 printf(" context=%s", scontext
);
245 } else if (opt
& PRINT_REAL
) {
251 status
|= print_user(euid
, NULL
);
252 else if (opt
& JUST_GROUP
)
253 status
|= print_group(egid
, NULL
);
255 else if (opt
& JUST_CONTEXT
) {
257 if (username
|| getcon(&scontext
)) {
258 bb_error_msg_and_die("can't get process context%s",
259 username
? " for a different user" : "");
261 fputs(scontext
, stdout
);
263 /* freecon(NULL) seems to be harmless */
264 if (ENABLE_FEATURE_CLEAN_UP
)
268 fflush_stdout_and_exit(status
);