1 /*
2 * runcon [ context |
3 * ( [ -c ] [ -r role ] [-t type] [ -u user ] [ -l levelrange ] )
4 * command [arg1 [arg2 ...] ]
5 *
6 * attempt to run the specified command with the specified context.
7 *
8 * -r role : use the current context with the specified role
9 * -t type : use the current context with the specified type
10 * -u user : use the current context with the specified user
11 * -l level : use the current context with the specified level range
12 * -c : compute process transition context before modifying
13 *
14 * Contexts are interpreted as follows:
15 *
16 * Number of MLS
17 * components system?
18 *
19 * 1 - type
20 * 2 - role:type
21 * 3 Y role:type:range
22 * 3 N user:role:type
23 * 4 Y user:role:type:range
24 * 4 N error
25 *
26 * Port to busybox: KaiGai Kohei <kaigai@kaigai.gr.jp>
27 * - based on coreutils-5.97 (in Fedora Core 6)
28 *
29 * Licensed under GPLv2, see file LICENSE in this source tree.
30 */
31 //config:config RUNCON
32 //config: bool "runcon (6.6 kb)"
33 //config: default n
34 //config: depends on SELINUX
35 //config: help
36 //config: Enable support to run command in specified security context.
37
38 //applet:IF_RUNCON(APPLET(runcon, BB_DIR_USR_BIN, BB_SUID_DROP))
39
40 //kbuild:lib-$(CONFIG_RUNCON) += runcon.o
41
42 //usage:#define runcon_trivial_usage
43 //usage: "[-c] [-u USER] [-r ROLE] [-t TYPE] [-l RANGE] PROG ARGS\n"
44 //usage: "runcon CONTEXT PROG ARGS"
45 //usage:#define runcon_full_usage "\n\n"
46 //usage: "Run PROG in a different security context\n"
47 //usage: "\n CONTEXT Complete security context\n"
48 //usage: "\n -c Compute process transition context before modifying"
49 //usage: "\n -t TYPE Type (for same role as parent)"
50 //usage: "\n -u USER User identity"
51 //usage: "\n -r ROLE Role"
52 //usage: "\n -l RNG Levelrange"
53
54 #include <selinux/context.h>
55 /* from deprecated <selinux/flask.h>: */
56 #undef SECCLASS_PROCESS
57 #define SECCLASS_PROCESS 2
58
59 #include "libbb.h"
60
runcon_compute_new_context(char * user,char * role,char * type,char * range,char * command,int compute_trans)61 static context_t runcon_compute_new_context(char *user, char *role, char *type, char *range,
62 char *command, int compute_trans)
63 {
64 context_t con;
65 security_context_t cur_context;
66
67 if (getcon(&cur_context))
68 bb_simple_error_msg_and_die("can't get current context");
69
70 if (compute_trans) {
71 security_context_t file_context, new_context;
72
73 if (getfilecon(command, &file_context) < 0)
74 bb_error_msg_and_die("can't retrieve attributes of '%s'",
75 command);
76 if (security_compute_create(cur_context, file_context,
77 SECCLASS_PROCESS, &new_context))
78 bb_simple_error_msg_and_die("unable to compute a new context");
79 cur_context = new_context;
80 }
81
82 con = context_new(cur_context);
83 if (!con)
84 bb_error_msg_and_die("'%s' is not a valid context", cur_context);
85 if (user && context_user_set(con, user))
86 bb_error_msg_and_die("can't set new user '%s'", user);
87 if (type && context_type_set(con, type))
88 bb_error_msg_and_die("can't set new type '%s'", type);
89 if (range && context_range_set(con, range))
90 bb_error_msg_and_die("can't set new range '%s'", range);
91 if (role && context_role_set(con, role))
92 bb_error_msg_and_die("can't set new role '%s'", role);
93
94 return con;
95 }
96
97 #if ENABLE_LONG_OPTS
98 static const char runcon_longopts[] ALIGN1 =
99 "user\0" Required_argument "u"
100 "role\0" Required_argument "r"
101 "type\0" Required_argument "t"
102 "range\0" Required_argument "l"
103 "compute\0" No_argument "c"
104 "help\0" No_argument "h"
105 ;
106 #endif
107
108 #define OPTS_ROLE (1<<0) /* r */
109 #define OPTS_TYPE (1<<1) /* t */
110 #define OPTS_USER (1<<2) /* u */
111 #define OPTS_RANGE (1<<3) /* l */
112 #define OPTS_COMPUTE (1<<4) /* c */
113 #define OPTS_HELP (1<<5) /* h */
114 #define OPTS_CONTEXT_COMPONENT (OPTS_ROLE | OPTS_TYPE | OPTS_USER | OPTS_RANGE)
115
116 int runcon_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
runcon_main(int argc UNUSED_PARAM,char ** argv)117 int runcon_main(int argc UNUSED_PARAM, char **argv)
118 {
119 char *role = NULL;
120 char *range = NULL;
121 char *user = NULL;
122 char *type = NULL;
123 char *context = NULL;
124 unsigned opts;
125 context_t con;
126
127 selinux_or_die();
128
129 opts = getopt32long(argv, "^"
130 "r:t:u:l:ch"
131 "\0" "-1",
132 runcon_longopts,
133 &role, &type, &user, &range
134 );
135 argv += optind;
136
137 if (!(opts & OPTS_CONTEXT_COMPONENT)) {
138 context = *argv++;
139 if (!argv[0])
140 bb_simple_error_msg_and_die("no command given");
141 }
142
143 if (context) {
144 con = context_new(context);
145 if (!con)
146 bb_error_msg_and_die("'%s' is not a valid context", context);
147 } else {
148 con = runcon_compute_new_context(user, role, type, range,
149 argv[0], opts & OPTS_COMPUTE);
150 }
151
152 if (security_check_context(context_str(con)))
153 bb_error_msg_and_die("'%s' is not a valid context",
154 context_str(con));
155
156 if (setexeccon(context_str(con)))
157 bb_error_msg_and_die("can't set up security context '%s'",
158 context_str(con));
159
160 BB_EXECVP_or_die(argv);
161 }
162