aboutsummaryrefslogtreecommitdiff
path: root/coreutils/id.c
blob: 064bd29d9efe17018f7f00827e967b6adc71921f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
/* vi: set sw=4 ts=4: */
/*
 * Mini id implementation for busybox
 *
 * Copyright (C) 2000 by Randolph Chung <tausq@debian.org>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

/* BB_AUDIT SUSv3 _NOT_ compliant -- option -G is not currently supported. */
/* 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>
 */

#include "libbb.h"
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>

#define PRINT_REAL        1
#define NAME_NOT_NUMBER   2
#define JUST_USER         4
#define JUST_GROUP        8
#if ENABLE_SELINUX
#define JUST_CONTEXT    16
#endif

static short printf_full(unsigned int id, const char *arg, const char prefix)
{
	const char *fmt = "%cid=%u";
	short status = EXIT_FAILURE;

	if (arg) {
		fmt = "%cid=%u(%s)";
		status = EXIT_SUCCESS;
	}
	printf(fmt, prefix, id, arg);
	return status;
}

int id_main(int argc, char **argv);
int id_main(int argc, char **argv)
{
	struct passwd *p;
	uid_t uid;
	gid_t gid;
	unsigned long flags;
	short status;
#if ENABLE_SELINUX
	security_context_t scontext;
#endif
	/* Don't allow -n -r -nr -ug -rug -nug -rnug */
	/* Don't allow more than one username */
	opt_complementary = "?1:?:u--g:g--u:r?ug:n?ug" USE_SELINUX(":u--Z:Z--u:g--Z:Z--g");
	flags = getopt32(argc, argv, "rnug" USE_SELINUX("Z"));

	/* This values could be overwritten later */
	uid = geteuid();
	gid = getegid();
	if (flags & PRINT_REAL) {
		uid = getuid();
		gid = getgid();
	}

	if (argv[optind]) {
		p = getpwnam(argv[optind]);
		/* xuname2uid is needed because it exits on failure */
		uid = xuname2uid(argv[optind]);
		gid = p->pw_gid;
		/* in this case PRINT_REAL is the same */
	}

	if (flags & (JUST_GROUP | JUST_USER USE_SELINUX(| JUST_CONTEXT))) {
		/* JUST_GROUP and JUST_USER are mutually exclusive */
		if (flags & NAME_NOT_NUMBER) {
			/* bb_getpwuid and bb_getgrgid exit on failure so puts cannot segfault */
			puts((flags & JUST_USER) ? bb_getpwuid(NULL, uid, -1 ) : bb_getgrgid(NULL, gid, -1 ));
		} else {
			if (flags & JUST_USER) {
				printf("%u\n", uid);
			}
			if (flags & JUST_GROUP) {
				printf("%u\n", gid);
			}
		}

#if ENABLE_SELINUX
		if (flags & JUST_CONTEXT) {
			selinux_or_die();
			if (argc - optind == 1) {
				bb_error_msg_and_die("user name can't be passed with -Z");
			}

			if (getcon(&scontext)) {
				bb_error_msg_and_die("can't get process context");
			}
			printf("%s\n", scontext);
		}
#endif
		/* exit */
		fflush_stdout_and_exit(EXIT_SUCCESS);
	}

	/* Print full info like GNU id */
	/* bb_getpwuid doesn't exit on failure here */
	status = printf_full(uid, bb_getpwuid(NULL, uid, 0), 'u');
	putchar(' ');
	/* bb_getgrgid doesn't exit on failure here */
	status |= printf_full(gid, bb_getgrgid(NULL, gid, 0), 'g');

#if ENABLE_SELINUX
	if (is_selinux_enabled()) {
		security_context_t mysid;
		const char *context;

		context = "unknown";
		getcon(&mysid);
		if (mysid) {
			context = alloca(strlen(mysid) + 1);
			strcpy((char*)context, mysid);
			freecon(mysid);
		}
		printf(" context=%s", context);
	}
#endif

	putchar('\n');
	fflush_stdout_and_exit(status);
}