summaryrefslogtreecommitdiff
path: root/selinux/runcon.c
blob: e94ff14540dcfc49466292ee84156084d64df7b7 (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
131
132
133
134
135
136
137
138
/*
 * runcon [ context |
 *         ( [ -c ] [ -r role ] [-t type] [ -u user ] [ -l levelrange ] )
 *         command [arg1 [arg2 ...] ]
 *
 * attempt to run the specified command with the specified context.
 *
 * -r role  : use the current context with the specified role
 * -t type  : use the current context with the specified type
 * -u user  : use the current context with the specified user
 * -l level : use the current context with the specified level range
 * -c       : compute process transition context before modifying
 *
 * Contexts are interpreted as follows:
 *
 * Number of       MLS
 * components    system?
 *
 *     1            -         type
 *     2            -         role:type
 *     3            Y         role:type:range
 *     3            N         user:role:type
 *     4            Y         user:role:type:range
 *     4            N         error
 *
 * Port to busybox: KaiGai Kohei <kaigai@kaigai.gr.jp>
 *                  - based on coreutils-5.97 (in Fedora Core 6)
 *
 * Licensed under GPLv2, see file LICENSE in this tarball for details.
 */
#include <getopt.h>
#include <selinux/context.h>
#include <selinux/flask.h>

#include "libbb.h"

static context_t runcon_compute_new_context(char *user, char *role, char *type, char *range,
					    char *command, int compute_trans)
{
	context_t con;
	security_context_t cur_context;

	if (getcon(&cur_context))
		bb_error_msg_and_die("cannot get current context");

	if (compute_trans) {
		security_context_t file_context, new_context;

		if (getfilecon(command, &file_context) < 0)
			bb_error_msg_and_die("cannot retrieve attributes of '%s'",
					     command);
		if (security_compute_create(cur_context, file_context,
					    SECCLASS_PROCESS, &new_context))
			bb_error_msg_and_die("unable to compute a new context");
		cur_context = new_context;
	}

	con = context_new(cur_context);
	if (!con)
		bb_error_msg_and_die("'%s' is not a valid context", cur_context);
	if (user && context_user_set(con, user))
		bb_error_msg_and_die("failed to set new user '%s'", user);
	if (type && context_type_set(con, type))
		bb_error_msg_and_die("failed to set new type '%s'", type);
	if (range && context_range_set(con, range))
		bb_error_msg_and_die("failed to set new range '%s'", range);
	if (role && context_role_set(con, role))
		bb_error_msg_and_die("failed to set new role '%s'", role);

	return con;
}

#if ENABLE_FEATURE_RUNCON_LONG_OPTIONS
static const char runcon_longopts[] ALIGN1 =
	"user\0"    Required_argument "u"
	"role\0"    Required_argument "r"
	"type\0"    Required_argument "t"
	"range\0"   Required_argument "l"
	"compute\0" No_argument "c"
	"help\0"    No_argument "h"
	;
#endif

#define OPTS_ROLE	(1<<0)	/* r */
#define OPTS_TYPE	(1<<1)	/* t */
#define OPTS_USER	(1<<2)	/* u */
#define OPTS_RANGE	(1<<3)	/* l */
#define OPTS_COMPUTE	(1<<4)	/* c */
#define OPTS_HELP	(1<<5)	/* h */
#define OPTS_CONTEXT_COMPONENT		(OPTS_ROLE | OPTS_TYPE | OPTS_USER | OPTS_RANGE)

int runcon_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int runcon_main(int argc UNUSED_PARAM, char **argv)
{
	char *role = NULL;
	char *range = NULL;
	char *user = NULL;
	char *type = NULL;
	char *context = NULL;
	unsigned opts;
	context_t con;

	selinux_or_die();

#if ENABLE_FEATURE_RUNCON_LONG_OPTIONS
	applet_long_options = runcon_longopts;
#endif
	opt_complementary = "-1";
	opts = getopt32(argv, "r:t:u:l:ch", &role, &type, &user, &range);
	argv += optind;

	if (!(opts & OPTS_CONTEXT_COMPONENT)) {
		context = *argv++;
		if (!argv[0])
			bb_error_msg_and_die("no command given");
	}

	if (context) {
		con = context_new(context);
		if (!con)
			bb_error_msg_and_die("'%s' is not a valid context", context);
	} else {
		con = runcon_compute_new_context(user, role, type, range,
				argv[0], opts & OPTS_COMPUTE);
	}

	if (security_check_context(context_str(con)))
		bb_error_msg_and_die("'%s' is not a valid context",
				     context_str(con));

	if (setexeccon(context_str(con)))
		bb_error_msg_and_die("cannot set up security context '%s'",
				     context_str(con));

	execvp(argv[0], argv);

	bb_perror_msg_and_die("cannot execute '%s'", argv[0]);
}