busybox/coreutils/id.c

/* vi: set sw=4 ts=4: */
/*
 * Mini id implementation for busybox
 *
 * Copyright (C) 2000 by Randolph Chung <tausq@debian.org>
 * Copyright (C) 2008 by Tito Ragusa <farmatito@tiscali.it>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

/* BB_AUDIT SUSv3 compliant. */
/* Hacked by Tito Ragusa (C) 2004 to handle usernames of whatever
 * length and to be more similar to GNU id.
 * -Z option support: by Yuichi Nakamura <ynakam@hitachisoft.jp>
 * Added -G option Tito Ragusa (C) 2008 for SUSv3.
 */

#include "libbb.h"

#if !ENABLE_USE_BB_PWD_GRP
#if defined(__UCLIBC_MAJOR__) && (__UCLIBC_MAJOR__ == 0)
#if (__UCLIBC_MINOR__ < 9) || (__UCLIBC_MINOR__ == 9 &&  __UCLIBC_SUBLEVEL__ < 30)
#error "Sorry, you need at least uClibc version 0.9.30 for id applet to build"
#endif
#endif
#endif

enum {
	PRINT_REAL      = (1 << 0),
	NAME_NOT_NUMBER = (1 << 1),
	JUST_USER       = (1 << 2),
	JUST_GROUP      = (1 << 3),
	JUST_ALL_GROUPS = (1 << 4),
#if ENABLE_SELINUX
	JUST_CONTEXT    = (1 << 5),
#endif
};

static int print_common(unsigned id, const char *name, const char *prefix)
{
	if (prefix) {
		printf("%s", prefix);
	}
	if (!(option_mask32 & NAME_NOT_NUMBER) || !name) {
		printf("%u", id);
	}
	if (!option_mask32 || (option_mask32 & NAME_NOT_NUMBER)) {
		if (name) {
			printf(option_mask32 ? "%s" : "(%s)", name);
		} else {
			/* Don't set error status flag in default mode */
			if (option_mask32) {
				if (ENABLE_DESKTOP)
					bb_error_msg("unknown ID %u", id);
				return EXIT_FAILURE;
			}
		}
	}
	return EXIT_SUCCESS;
}

static int print_group(gid_t id, const char *prefix)
{
	return print_common(id, gid2group(id), prefix);
}

static int print_user(uid_t id, const char *prefix)
{
	return print_common(id, uid2uname(id), prefix);
}

/* On error set *n < 0 and return >= 0
 * If *n is too small, update it and return < 0
 *  (ok to trash groups[] in both cases)
 * Otherwise fill in groups[] and return >= 0
 */
static int get_groups(const char *username, gid_t rgid, gid_t *groups, int *n)
{
	int m;

	if (username) {
		/* If the user is a member of more than
		 * *n groups, then -1 is returned. Otherwise >= 0.
		 * (and no defined way of detecting errors?!) */
		m = getgrouplist(username, rgid, groups, n);
		/* I guess *n < 0 might indicate error. Anyway,
		 * malloc'ing -1 bytes won't be good, so: */
		//if (*n < 0)
		//	return 0;
		//return m;
		//commented out here, happens below anyway
	} else {
		/* On error -1 is returned, which ends up in *n */
		int nn = getgroups(*n, groups);
		/* 0: nn <= *n, groups[] was big enough; -1 otherwise */
		m = - (nn > *n);
		*n = nn;
	}
	if (*n < 0)
		return 0; /* error, don't return < 0! */
	return m;
}

int id_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int id_main(int argc UNUSED_PARAM, char **argv)
{
	uid_t ruid;
	gid_t rgid;
	uid_t euid;
	gid_t egid;
	unsigned opt;
	int i;
	int status = EXIT_SUCCESS;
	const char *prefix;
	const char *username;
#if ENABLE_SELINUX
	security_context_t scontext = NULL;
#endif
	/* Don't allow -n -r -nr -ug -rug -nug -rnug -uZ -gZ -GZ*/
	/* Don't allow more than one username */
	opt_complementary = "?1:u--g:g--u:G--u:u--G:g--G:G--g:r?ugG:n?ugG"
			 IF_SELINUX(":u--Z:Z--u:g--Z:Z--g:G--Z:Z--G");
	opt = getopt32(argv, "rnugG" IF_SELINUX("Z"));

	username = argv[optind];
	if (username) {
		struct passwd *p = xgetpwnam(username);
		euid = ruid = p->pw_uid;
		egid = rgid = p->pw_gid;
	} else {
		egid = getegid();
		rgid = getgid();
		euid = geteuid();
		ruid = getuid();
	}
	/* JUST_ALL_GROUPS ignores -r PRINT_REAL flag even if man page for */
	/* id says: print the real ID instead of the effective ID, with -ugG */
	/* in fact in this case egid is always printed if egid != rgid */
	if (!opt || (opt & JUST_ALL_GROUPS)) {
		gid_t *groups;
		int n;

		if (!opt) {
			/* Default Mode */
			status |= print_user(ruid, "uid=");
			status |= print_group(rgid, " gid=");
			if (euid != ruid)
				status |= print_user(euid, " euid=");
			if (egid != rgid)
				status |= print_group(egid, " egid=");
		} else {
			/* JUST_ALL_GROUPS */
			status |= print_group(rgid, NULL);
			if (egid != rgid)
				status |= print_group(egid, " ");
		}
		/* We are supplying largish buffer, trying
		 * to not run get_groups() twice. That might be slow
		 * ("user database in remote SQL server" case) */
		groups = xmalloc(64 * sizeof(gid_t));
		n = 64;
		if (get_groups(username, rgid, groups, &n) < 0) {
			/* Need bigger buffer after all */
			groups = xrealloc(groups, n * sizeof(gid_t));
			get_groups(username, rgid, groups, &n);
		}
		if (n > 0) {
			/* Print the list */
			prefix = " groups=";
			for (i = 0; i < n; i++) {
				if (opt && (groups[i] == rgid || groups[i] == egid))
					continue;
				status |= print_group(groups[i], opt ? " " : prefix);
				prefix = ",";
			}
		} else if (n < 0) { /* error in get_groups() */
			if (!ENABLE_DESKTOP)
				bb_error_msg_and_die("can't get groups");
			else
				return EXIT_FAILURE;
		}
		if (ENABLE_FEATURE_CLEAN_UP)
			free(groups);
#if ENABLE_SELINUX
		if (is_selinux_enabled()) {
			if (getcon(&scontext) == 0)
				printf(" context=%s", scontext);
		}
#endif
	} else if (opt & PRINT_REAL) {
		euid = ruid;
		egid = rgid;
	}

	if (opt & JUST_USER)
		status |= print_user(euid, NULL);
	else if (opt & JUST_GROUP)
		status |= print_group(egid, NULL);
#if ENABLE_SELINUX
	else if (opt & JUST_CONTEXT) {
		selinux_or_die();
		if (username || getcon(&scontext)) {
			bb_error_msg_and_die("can't get process context%s",
				username ? " for a different user" : "");
		}
		fputs(scontext, stdout);
	}
	/* freecon(NULL) seems to be harmless */
	if (ENABLE_FEATURE_CLEAN_UP)
		freecon(scontext);
#endif
	bb_putchar('\n');
	fflush_stdout_and_exit(status);
}
1	niro	532	/* vi: set sw=4 ts=4: */
2			/*
3			* Mini id implementation for busybox
4			*
5			* Copyright (C) 2000 by Randolph Chung <tausq@debian.org>
6	niro	816	* Copyright (C) 2008 by Tito Ragusa <farmatito@tiscali.it>
7	niro	532	*
8			* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
9			*/
10
11	niro	816	/* 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.
16	niro	532	*/
17
18	niro	816	#include "libbb.h"
19	niro	532
20	niro	816	#if !ENABLE_USE_BB_PWD_GRP
21			#if defined(__UCLIBC_MAJOR__) && (__UCLIBC_MAJOR__ == 0)
22			#if (__UCLIBC_MINOR__ < 9) \|\| (__UCLIBC_MINOR__ == 9 && __UCLIBC_SUBLEVEL__ < 30)
23			#error "Sorry, you need at least uClibc version 0.9.30 for id applet to build"
24	niro	532	#endif
25	niro	816	#endif
26			#endif
27	niro	532
28	niro	816	enum {
29			PRINT_REAL = (1 << 0),
30			NAME_NOT_NUMBER = (1 << 1),
31			JUST_USER = (1 << 2),
32			JUST_GROUP = (1 << 3),
33			JUST_ALL_GROUPS = (1 << 4),
34			#if ENABLE_SELINUX
35			JUST_CONTEXT = (1 << 5),
36			#endif
37			};
38	niro	532
39	niro	984	static int print_common(unsigned id, const char name, const char prefix)
40	niro	532	{
41	niro	816	if (prefix) {
42			printf("%s", prefix);
43	niro	532	}
44	niro	816	if (!(option_mask32 & NAME_NOT_NUMBER) \|\| !name) {
45			printf("%u", id);
46			}
47			if (!option_mask32 \|\| (option_mask32 & NAME_NOT_NUMBER)) {
48			if (name) {
49			printf(option_mask32 ? "%s" : "(%s)", name);
50			} else {
51			/* Don't set error status flag in default mode */
52			if (option_mask32) {
53			if (ENABLE_DESKTOP)
54			bb_error_msg("unknown ID %u", id);
55			return EXIT_FAILURE;
56			}
57			}
58			}
59			return EXIT_SUCCESS;
60	niro	532	}
61
62	niro	816	static int print_group(gid_t id, const char *prefix)
63	niro	532	{
64	niro	984	return print_common(id, gid2group(id), prefix);
65	niro	816	}
66	niro	532
67	niro	816	static int print_user(uid_t id, const char *prefix)
68			{
69	niro	984	return print_common(id, uid2uname(id), prefix);
70	niro	816	}
71	niro	532
72	niro	816	/* On error set *n < 0 and return >= 0
73			* If *n is too small, update it and return < 0
74			* (ok to trash groups[] in both cases)
75			* Otherwise fill in groups[] and return >= 0
76			*/
77			static int get_groups(const char username, gid_t rgid, gid_t groups, int *n)
78			{
79			int m;
80
81			if (username) {
82			/* If the user is a member of more than
83			* *n groups, then -1 is returned. Otherwise >= 0.
84			* (and no defined way of detecting errors?!) */
85			m = getgrouplist(username, rgid, groups, n);
86			/* I guess *n < 0 might indicate error. Anyway,
87			* malloc'ing -1 bytes won't be good, so: */
88			//if (*n < 0)
89			// return 0;
90			//return m;
91			//commented out here, happens below anyway
92			} else {
93			/* On error -1 is returned, which ends up in n /
94			int nn = getgroups(*n, groups);
95			/* 0: nn <= n, groups[] was big enough; -1 otherwise /
96			m = - (nn > *n);
97			*n = nn;
98	niro	532	}
99	niro	816	if (*n < 0)
100			return 0; /* error, don't return < 0! */
101			return m;
102			}
103	niro	532
104	niro	816	int id_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
105			int id_main(int argc UNUSED_PARAM, char **argv)
106			{
107			uid_t ruid;
108			gid_t rgid;
109			uid_t euid;
110			gid_t egid;
111			unsigned opt;
112			int i;
113			int status = EXIT_SUCCESS;
114			const char *prefix;
115			const char *username;
116			#if ENABLE_SELINUX
117			security_context_t scontext = NULL;
118			#endif
119			/* Don't allow -n -r -nr -ug -rug -nug -rnug -uZ -gZ -GZ*/
120			/* Don't allow more than one username */
121			opt_complementary = "?1:u--g:g--u:G--u:u--G:g--G:G--g:r?ugG:n?ugG"
122	niro	984	IF_SELINUX(":u--Z:Z--u:g--Z:Z--g:G--Z:Z--G");
123			opt = getopt32(argv, "rnugG" IF_SELINUX("Z"));
124	niro	816
125			username = argv[optind];
126			if (username) {
127	niro	984	struct passwd *p = xgetpwnam(username);
128	niro	816	euid = ruid = p->pw_uid;
129			egid = rgid = p->pw_gid;
130			} else {
131			egid = getegid();
132			rgid = getgid();
133			euid = geteuid();
134			ruid = getuid();
135	niro	532	}
136	niro	816	/* JUST_ALL_GROUPS ignores -r PRINT_REAL flag even if man page for */
137			/* id says: print the real ID instead of the effective ID, with -ugG */
138			/* in fact in this case egid is always printed if egid != rgid */
139			if (!opt \|\| (opt & JUST_ALL_GROUPS)) {
140			gid_t *groups;
141			int n;
142	niro	532
143	niro	816	if (!opt) {
144			/* Default Mode */
145			status \|= print_user(ruid, "uid=");
146			status \|= print_group(rgid, " gid=");
147			if (euid != ruid)
148			status \|= print_user(euid, " euid=");
149			if (egid != rgid)
150			status \|= print_group(egid, " egid=");
151	niro	532	} else {
152	niro	816	/* JUST_ALL_GROUPS */
153			status \|= print_group(rgid, NULL);
154			if (egid != rgid)
155			status \|= print_group(egid, " ");
156	niro	532	}
157	niro	816	/* We are supplying largish buffer, trying
158			* to not run get_groups() twice. That might be slow
159			* ("user database in remote SQL server" case) */
160			groups = xmalloc(64 * sizeof(gid_t));
161			n = 64;
162			if (get_groups(username, rgid, groups, &n) < 0) {
163			/* Need bigger buffer after all */
164			groups = xrealloc(groups, n * sizeof(gid_t));
165			get_groups(username, rgid, groups, &n);
166			}
167			if (n > 0) {
168			/* Print the list */
169			prefix = " groups=";
170			for (i = 0; i < n; i++) {
171			if (opt && (groups[i] == rgid \|\| groups[i] == egid))
172			continue;
173			status \|= print_group(groups[i], opt ? " " : prefix);
174			prefix = ",";
175			}
176			} else if (n < 0) { /* error in get_groups() */
177			if (!ENABLE_DESKTOP)
178	niro	984	bb_error_msg_and_die("can't get groups");
179	niro	816	else
180			return EXIT_FAILURE;
181			}
182			if (ENABLE_FEATURE_CLEAN_UP)
183			free(groups);
184			#if ENABLE_SELINUX
185			if (is_selinux_enabled()) {
186			if (getcon(&scontext) == 0)
187			printf(" context=%s", scontext);
188			}
189			#endif
190			} else if (opt & PRINT_REAL) {
191			euid = ruid;
192			egid = rgid;
193	niro	532	}
194
195	niro	816	if (opt & JUST_USER)
196			status \|= print_user(euid, NULL);
197			else if (opt & JUST_GROUP)
198			status \|= print_group(egid, NULL);
199			#if ENABLE_SELINUX
200			else if (opt & JUST_CONTEXT) {
201			selinux_or_die();
202			if (username \|\| getcon(&scontext)) {
203			bb_error_msg_and_die("can't get process context%s",
204			username ? " for a different user" : "");
205	niro	532	}
206	niro	816	fputs(scontext, stdout);
207	niro	532	}
208	niro	816	/* freecon(NULL) seems to be harmless */
209			if (ENABLE_FEATURE_CLEAN_UP)
210			freecon(scontext);
211	niro	532	#endif
212	niro	816	bb_putchar('\n');
213	niro	532	fflush_stdout_and_exit(status);
214			}