release/src/router/busybox/selinux/runcon.c

   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
  32 //usage:#define runcon_trivial_usage
  33 //usage:       "[-c] [-u USER] [-r ROLE] [-t TYPE] [-l RANGE] PROG ARGS\n"
  34 //usage:       "runcon CONTEXT PROG ARGS"
  35 //usage:#define runcon_full_usage "\n\n"
  36 //usage:       "Run PROG in a different security context\n"
  37 //usage:     "\n        CONTEXT         Complete security context\n"
  38 //usage:        IF_FEATURE_RUNCON_LONG_OPTIONS(
  39 //usage:     "\n        -c,--compute    Compute process transition context before modifying"
  40 //usage:     "\n        -t,--type=TYPE  Type (for same role as parent)"
  41 //usage:     "\n        -u,--user=USER  User identity"
  42 //usage:     "\n        -r,--role=ROLE  Role"
  43 //usage:     "\n        -l,--range=RNG  Levelrange"
  44 //usage:        )
  45 //usage:        IF_NOT_FEATURE_RUNCON_LONG_OPTIONS(
  46 //usage:     "\n        -c      Compute process transition context before modifying"
  47 //usage:     "\n        -t TYPE Type (for same role as parent)"
  48 //usage:     "\n        -u USER User identity"
  49 //usage:     "\n        -r ROLE Role"
  50 //usage:     "\n        -l RNG  Levelrange"
  51 //usage:        )
  52
  53 #include <selinux/context.h>
  54 #include <selinux/flask.h>
  55
  56 #include "libbb.h"
  57
  58 static context_t runcon_compute_new_context(char *user, char *role, char *type, char *range,
  59                                             char *command, int compute_trans)
  60 {
  61         context_t con;
  62         security_context_t cur_context;
  63
  64         if (getcon(&cur_context))
  65                 bb_error_msg_and_die("can't get current context");
  66
  67         if (compute_trans) {
  68                 security_context_t file_context, new_context;
  69
  70                 if (getfilecon(command, &file_context) < 0)
  71                         bb_error_msg_and_die("can't retrieve attributes of '%s'",
  72                                              command);
  73                 if (security_compute_create(cur_context, file_context,
  74                                             SECCLASS_PROCESS, &new_context))
  75                         bb_error_msg_and_die("unable to compute a new context");
  76                 cur_context = new_context;
  77         }
  78
  79         con = context_new(cur_context);
  80         if (!con)
  81                 bb_error_msg_and_die("'%s' is not a valid context", cur_context);
  82         if (user && context_user_set(con, user))
  83                 bb_error_msg_and_die("can't set new user '%s'", user);
  84         if (type && context_type_set(con, type))
  85                 bb_error_msg_and_die("can't set new type '%s'", type);
  86         if (range && context_range_set(con, range))
  87                 bb_error_msg_and_die("can't set new range '%s'", range);
  88         if (role && context_role_set(con, role))
  89                 bb_error_msg_and_die("can't set new role '%s'", role);
  90
  91         return con;
  92 }
  93
  94 #if ENABLE_FEATURE_RUNCON_LONG_OPTIONS
  95 static const char runcon_longopts[] ALIGN1 =
  96         "user\0"    Required_argument "u"
  97         "role\0"    Required_argument "r"
  98         "type\0"    Required_argument "t"
  99         "range\0"   Required_argument "l"
 100         "compute\0" No_argument "c"
 101         "help\0"    No_argument "h"
 102         ;
 103 #endif
 104
 105 #define OPTS_ROLE       (1<<0)  /* r */
 106 #define OPTS_TYPE       (1<<1)  /* t */
 107 #define OPTS_USER       (1<<2)  /* u */
 108 #define OPTS_RANGE      (1<<3)  /* l */
 109 #define OPTS_COMPUTE    (1<<4)  /* c */
 110 #define OPTS_HELP       (1<<5)  /* h */
 111 #define OPTS_CONTEXT_COMPONENT          (OPTS_ROLE | OPTS_TYPE | OPTS_USER | OPTS_RANGE)
 112
 113 int runcon_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 114 int runcon_main(int argc UNUSED_PARAM, char **argv)
 115 {
 116         char *role = NULL;
 117         char *range = NULL;
 118         char *user = NULL;
 119         char *type = NULL;
 120         char *context = NULL;
 121         unsigned opts;
 122         context_t con;
 123
 124         selinux_or_die();
 125
 126 #if ENABLE_FEATURE_RUNCON_LONG_OPTIONS
 127         applet_long_options = runcon_longopts;
 128 #endif
 129         opt_complementary = "-1";
 130         opts = getopt32(argv, "r:t:u:l:ch", &role, &type, &user, &range);
 131         argv += optind;
 132
 133         if (!(opts & OPTS_CONTEXT_COMPONENT)) {
 134                 context = *argv++;
 135                 if (!argv[0])
 136                         bb_error_msg_and_die("no command given");
 137         }
 138
 139         if (context) {
 140                 con = context_new(context);
 141                 if (!con)
 142                         bb_error_msg_and_die("'%s' is not a valid context", context);
 143         } else {
 144                 con = runcon_compute_new_context(user, role, type, range,
 145                                 argv[0], opts & OPTS_COMPUTE);
 146         }
 147
 148         if (security_check_context(context_str(con)))
 149                 bb_error_msg_and_die("'%s' is not a valid context",
 150                                      context_str(con));
 151
 152         if (setexeccon(context_str(con)))
 153                 bb_error_msg_and_die("can't set up security context '%s'",
 154                                      context_str(con));
 155
 156         BB_EXECVP_or_die(argv);
 157 }