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.
20 /* This is a NOEXEC applet. Be very careful! */
22 #if !ENABLE_USE_BB_PWD_GRP
23 #if defined(__UCLIBC_MAJOR__) && (__UCLIBC_MAJOR__ == 0)
24 #if (__UCLIBC_MINOR__ < 9) || (__UCLIBC_MINOR__ == 9 && __UCLIBC_SUBLEVEL__ < 30)
25 #error "Sorry, you need at least uClibc version 0.9.30 for id applet to build"
31 PRINT_REAL = (1 << 0),
32 NAME_NOT_NUMBER = (1 << 1),
34 JUST_GROUP = (1 << 3),
35 JUST_ALL_GROUPS = (1 << 4),
37 JUST_CONTEXT = (1 << 5),
41 static int print_common(unsigned id, const char *name, const char *prefix)
46 if (!(option_mask32 & NAME_NOT_NUMBER) || !name) {
49 if (!option_mask32 || (option_mask32 & NAME_NOT_NUMBER)) {
51 printf(option_mask32 ? "%s" : "(%s)", name);
53 /* Don't set error status flag in default mode */
56 bb_error_msg("unknown ID %u", id);
64 static int print_group(gid_t id, const char *prefix)
66 return print_common(id, gid2group(id), prefix);
69 static int print_user(uid_t id, const char *prefix)
71 return print_common(id, uid2uname(id), prefix);
74 /* On error set *n < 0 and return >= 0
75 * If *n is too small, update it and return < 0
76 * (ok to trash groups[] in both cases)
77 * Otherwise fill in groups[] and return >= 0
79 static int get_groups(const char *username, gid_t rgid, gid_t *groups, int *n)
84 /* If the user is a member of more than
85 * *n groups, then -1 is returned. Otherwise >= 0.
86 * (and no defined way of detecting errors?!) */
87 m = getgrouplist(username, rgid, groups, n);
88 /* I guess *n < 0 might indicate error. Anyway,
89 * malloc'ing -1 bytes won't be good, so: */
93 //commented out here, happens below anyway
95 /* On error -1 is returned, which ends up in *n */
96 int nn = getgroups(*n, groups);
97 /* 0: nn <= *n, groups[] was big enough; -1 otherwise */
102 return 0; /* error, don't return < 0! */
106 int id_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
107 int id_main(int argc UNUSED_PARAM, char **argv)
115 int status = EXIT_SUCCESS;
117 const char *username;
119 security_context_t scontext = NULL;
121 /* Don't allow -n -r -nr -ug -rug -nug -rnug -uZ -gZ -GZ*/
122 /* Don't allow more than one username */
123 opt_complementary = "?1:u--g:g--u:G--u:u--G:g--G:G--g:r?ugG:n?ugG"
124 IF_SELINUX(":u--Z:Z--u:g--Z:Z--g:G--Z:Z--G");
125 opt = getopt32(argv, "rnugG" IF_SELINUX("Z"));
127 username = argv[optind];
129 struct passwd *p = xgetpwnam(username);
130 euid = ruid = p->pw_uid;
131 egid = rgid = p->pw_gid;
138 /* JUST_ALL_GROUPS ignores -r PRINT_REAL flag even if man page for */
139 /* id says: print the real ID instead of the effective ID, with -ugG */
140 /* in fact in this case egid is always printed if egid != rgid */
141 if (!opt || (opt & JUST_ALL_GROUPS)) {
147 status |= print_user(ruid, "uid=");
148 status |= print_group(rgid, " gid=");
150 status |= print_user(euid, " euid=");
152 status |= print_group(egid, " egid=");
154 /* JUST_ALL_GROUPS */
155 status |= print_group(rgid, NULL);
157 status |= print_group(egid, " ");
159 /* We are supplying largish buffer, trying
160 * to not run get_groups() twice. That might be slow
161 * ("user database in remote SQL server" case) */
162 groups = xmalloc(64 * sizeof(gid_t));
164 if (get_groups(username, rgid, groups, &n) < 0) {
165 /* Need bigger buffer after all */
166 groups = xrealloc(groups, n * sizeof(gid_t));
167 get_groups(username, rgid, groups, &n);
172 for (i = 0; i < n; i++) {
173 if (opt && (groups[i] == rgid || groups[i] == egid))
175 status |= print_group(groups[i], opt ? " " : prefix);
178 } else if (n < 0) { /* error in get_groups() */
180 bb_error_msg_and_die("can't get groups");
184 if (ENABLE_FEATURE_CLEAN_UP)
187 if (is_selinux_enabled()) {
188 if (getcon(&scontext) == 0)
189 printf(" context=%s", scontext);
192 } else if (opt & PRINT_REAL) {
198 status |= print_user(euid, NULL);
199 else if (opt & JUST_GROUP)
200 status |= print_group(egid, NULL);
202 else if (opt & JUST_CONTEXT) {
204 if (username || getcon(&scontext)) {
205 bb_error_msg_and_die("can't get process context%s",
206 username ? " for a different user" : "");
208 fputs(scontext, stdout);
210 /* freecon(NULL) seems to be harmless */
211 if (ENABLE_FEATURE_CLEAN_UP)
215 fflush_stdout_and_exit(status);