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.
18 //usage:#define id_trivial_usage
19 //usage: "[OPTIONS] [USER]"
20 //usage:#define id_full_usage "\n\n"
21 //usage: "Print information about USER or the current user\n"
23 //usage: "\n -Z Security context"
25 //usage: "\n -u User ID"
26 //usage: "\n -g Group ID"
27 //usage: "\n -G Supplementary group IDs"
28 //usage: "\n -n Print names instead of numbers"
29 //usage: "\n -r Print real ID instead of effective ID"
31 //usage:#define id_example_usage
33 //usage: "uid=1000(andersen) gid=1000(andersen)\n"
37 /* This is a NOEXEC applet. Be very careful! */
39 #if !ENABLE_USE_BB_PWD_GRP
40 #if defined(__UCLIBC_MAJOR__) && (__UCLIBC_MAJOR__ == 0)
41 #if (__UCLIBC_MINOR__ < 9) || (__UCLIBC_MINOR__ == 9 && __UCLIBC_SUBLEVEL__ < 30)
42 #error "Sorry, you need at least uClibc version 0.9.30 for id applet to build"
48 PRINT_REAL = (1 << 0),
49 NAME_NOT_NUMBER = (1 << 1),
51 JUST_GROUP = (1 << 3),
52 JUST_ALL_GROUPS = (1 << 4),
54 JUST_CONTEXT = (1 << 5),
58 static int print_common(unsigned id, const char *name, const char *prefix)
63 if (!(option_mask32 & NAME_NOT_NUMBER) || !name) {
66 if (!option_mask32 || (option_mask32 & NAME_NOT_NUMBER)) {
68 printf(option_mask32 ? "%s" : "(%s)", name);
70 /* Don't set error status flag in default mode */
73 bb_error_msg("unknown ID %u", id);
81 static int print_group(gid_t id, const char *prefix)
83 return print_common(id, gid2group(id), prefix);
86 static int print_user(uid_t id, const char *prefix)
88 return print_common(id, uid2uname(id), prefix);
91 /* On error set *n < 0 and return >= 0
92 * If *n is too small, update it and return < 0
93 * (ok to trash groups[] in both cases)
94 * Otherwise fill in groups[] and return >= 0
96 static int get_groups(const char *username, gid_t rgid, gid_t *groups, int *n)
101 /* If the user is a member of more than
102 * *n groups, then -1 is returned. Otherwise >= 0.
103 * (and no defined way of detecting errors?!) */
104 m = getgrouplist(username, rgid, groups, n);
105 /* I guess *n < 0 might indicate error. Anyway,
106 * malloc'ing -1 bytes won't be good, so: */
110 //commented out here, happens below anyway
112 /* On error -1 is returned, which ends up in *n */
113 int nn = getgroups(*n, groups);
114 /* 0: nn <= *n, groups[] was big enough; -1 otherwise */
119 return 0; /* error, don't return < 0! */
123 int id_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
124 int id_main(int argc UNUSED_PARAM, char **argv)
132 int status = EXIT_SUCCESS;
134 const char *username;
136 security_context_t scontext = NULL;
138 /* Don't allow -n -r -nr -ug -rug -nug -rnug -uZ -gZ -GZ*/
139 /* Don't allow more than one username */
140 opt_complementary = "?1:u--g:g--u:G--u:u--G:g--G:G--g:r?ugG:n?ugG"
141 IF_SELINUX(":u--Z:Z--u:g--Z:Z--g:G--Z:Z--G");
142 opt = getopt32(argv, "rnugG" IF_SELINUX("Z"));
144 username = argv[optind];
146 struct passwd *p = xgetpwnam(username);
147 euid = ruid = p->pw_uid;
148 egid = rgid = p->pw_gid;
155 /* JUST_ALL_GROUPS ignores -r PRINT_REAL flag even if man page for */
156 /* id says: print the real ID instead of the effective ID, with -ugG */
157 /* in fact in this case egid is always printed if egid != rgid */
158 if (!opt || (opt & JUST_ALL_GROUPS)) {
164 status |= print_user(ruid, "uid=");
165 status |= print_group(rgid, " gid=");
167 status |= print_user(euid, " euid=");
169 status |= print_group(egid, " egid=");
171 /* JUST_ALL_GROUPS */
172 status |= print_group(rgid, NULL);
174 status |= print_group(egid, " ");
176 /* We are supplying largish buffer, trying
177 * to not run get_groups() twice. That might be slow
178 * ("user database in remote SQL server" case) */
179 groups = xmalloc(64 * sizeof(gid_t));
181 if (get_groups(username, rgid, groups, &n) < 0) {
182 /* Need bigger buffer after all */
183 groups = xrealloc(groups, n * sizeof(gid_t));
184 get_groups(username, rgid, groups, &n);
189 for (i = 0; i < n; i++) {
190 if (opt && (groups[i] == rgid || groups[i] == egid))
192 status |= print_group(groups[i], opt ? " " : prefix);
195 } else if (n < 0) { /* error in get_groups() */
197 bb_error_msg_and_die("can't get groups");
200 if (ENABLE_FEATURE_CLEAN_UP)
203 if (is_selinux_enabled()) {
204 if (getcon(&scontext) == 0)
205 printf(" context=%s", scontext);
208 } else if (opt & PRINT_REAL) {
214 status |= print_user(euid, NULL);
215 else if (opt & JUST_GROUP)
216 status |= print_group(egid, NULL);
218 else if (opt & JUST_CONTEXT) {
220 if (username || getcon(&scontext)) {
221 bb_error_msg_and_die("can't get process context%s",
222 username ? " for a different user" : "");
224 fputs(scontext, stdout);
226 /* freecon(NULL) seems to be harmless */
227 if (ENABLE_FEATURE_CLEAN_UP)
231 fflush_stdout_and_exit(status);