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 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
  58static 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
  95static 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
 113int runcon_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 114int 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}
 158