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