LXR 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 tarball for details.
  30 */
  31#include <getopt.h>
  32#include <selinux/context.h>
  33#include <selinux/flask.h>
  34
  35#include "libbb.h"
  36
  37static context_t runcon_compute_new_context(char *user, char *role, char *type, char *range,
  38                                            char *command, int compute_trans)
  39{
  40        context_t con;
  41        security_context_t cur_context;
  42
  43        if (getcon(&cur_context))
  44                bb_error_msg_and_die("can't get current context");
  45
  46        if (compute_trans) {
  47                security_context_t file_context, new_context;
  48
  49                if (getfilecon(command, &file_context) < 0)
  50                        bb_error_msg_and_die("can't retrieve attributes of '%s'",
  51                                             command);
  52                if (security_compute_create(cur_context, file_context,
  53                                            SECCLASS_PROCESS, &new_context))
  54                        bb_error_msg_and_die("unable to compute a new context");
  55                cur_context = new_context;
  56        }
  57
  58        con = context_new(cur_context);
  59        if (!con)
  60                bb_error_msg_and_die("'%s' is not a valid context", cur_context);
  61        if (user && context_user_set(con, user))
  62                bb_error_msg_and_die("can't set new user '%s'", user);
  63        if (type && context_type_set(con, type))
  64                bb_error_msg_and_die("can't set new type '%s'", type);
  65        if (range && context_range_set(con, range))
  66                bb_error_msg_and_die("can't set new range '%s'", range);
  67        if (role && context_role_set(con, role))
  68                bb_error_msg_and_die("can't set new role '%s'", role);
  69
  70        return con;
  71}
  72
  73#if ENABLE_FEATURE_RUNCON_LONG_OPTIONS
  74static const char runcon_longopts[] ALIGN1 =
  75        "user\0"    Required_argument "u"
  76        "role\0"    Required_argument "r"
  77        "type\0"    Required_argument "t"
  78        "range\0"   Required_argument "l"
  79        "compute\0" No_argument "c"
  80        "help\0"    No_argument "h"
  81        ;
  82#endif
  83
  84#define OPTS_ROLE       (1<<0)  /* r */
  85#define OPTS_TYPE       (1<<1)  /* t */
  86#define OPTS_USER       (1<<2)  /* u */
  87#define OPTS_RANGE      (1<<3)  /* l */
  88#define OPTS_COMPUTE    (1<<4)  /* c */
  89#define OPTS_HELP       (1<<5)  /* h */
  90#define OPTS_CONTEXT_COMPONENT          (OPTS_ROLE | OPTS_TYPE | OPTS_USER | OPTS_RANGE)
  91
  92int runcon_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  93int runcon_main(int argc UNUSED_PARAM, char **argv)
  94{
  95        char *role = NULL;
  96        char *range = NULL;
  97        char *user = NULL;
  98        char *type = NULL;
  99        char *context = NULL;
 100        unsigned opts;
 101        context_t con;
 102
 103        selinux_or_die();
 104
 105#if ENABLE_FEATURE_RUNCON_LONG_OPTIONS
 106        applet_long_options = runcon_longopts;
 107#endif
 108        opt_complementary = "-1";
 109        opts = getopt32(argv, "r:t:u:l:ch", &role, &type, &user, &range);
 110        argv += optind;
 111
 112        if (!(opts & OPTS_CONTEXT_COMPONENT)) {
 113                context = *argv++;
 114                if (!argv[0])
 115                        bb_error_msg_and_die("no command given");
 116        }
 117
 118        if (context) {
 119                con = context_new(context);
 120                if (!con)
 121                        bb_error_msg_and_die("'%s' is not a valid context", context);
 122        } else {
 123                con = runcon_compute_new_context(user, role, type, range,
 124                                argv[0], opts & OPTS_COMPUTE);
 125        }
 126
 127        if (security_check_context(context_str(con)))
 128                bb_error_msg_and_die("'%s' is not a valid context",
 129                                     context_str(con));
 130
 131        if (setexeccon(context_str(con)))
 132                bb_error_msg_and_die("can't set up security context '%s'",
 133                                     context_str(con));
 134
 135        execvp(argv[0], argv);
 136        bb_perror_msg_and_die("can't execute '%s'", argv[0]);
 137}
 138