src/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
  27 #include <config.h>
  28 #include <stdio.h>
  29 #include <getopt.h>
  30 #include <selinux/selinux.h>
  31 #include <selinux/context.h>
  32 #ifdef HAVE_SELINUX_FLASK_H
  33 # include <selinux/flask.h>
  34 #else
  35 # define SECCLASS_PROCESS 0
  36 #endif
  37 #include <sys/types.h>
  38 #include "system.h"
  39 #include "error.h"
  40 #include "quote.h"
  41 #include "quotearg.h"
  42
  43 /* The official name of this program (e.g., no `g' prefix).  */
  44 #define PROGRAM_NAME "runcon"
  45
  46 #define AUTHORS proper_name ("Russell Coker")
  47
  48 static struct option long_options[] = {
  49   {"role", required_argument, NULL, 'r'},
  50   {"type", required_argument, NULL, 't'},
  51   {"user", required_argument, NULL, 'u'},
  52   {"range", required_argument, NULL, 'l'},
  53   {"compute", no_argument, NULL, 'c'},
  54   {GETOPT_HELP_OPTION_DECL},
  55   {GETOPT_VERSION_OPTION_DECL},
  56   {NULL, 0, NULL, 0}
  57 };
  58
  59 /* The name the program was run with. */
  60 char *program_name;
  61
  62 void
  63 usage (int status)
  64 {
  65   if (status != EXIT_SUCCESS)
  66     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  67              program_name);
  68   else
  69     {
  70       printf (_("\
  71 Usage: %s CONTEXT COMMAND [args]\n\
  72   or:  %s [ -c ] [-u USER] [-r ROLE] [-t TYPE] [-l RANGE] COMMAND [args]\n\
  73 "), program_name, program_name);
  74       fputs (_("\
  75 Run a program in a different security context.\n\
  76 With neither CONTEXT nor COMMAND, print the current security context.\n\
  77 \n\
  78   CONTEXT            Complete security context\n\
  79   -c, --compute      compute process transition context before modifying\n\
  80   -t, --type=TYPE    type (for same role as parent)\n\
  81   -u, --user=USER    user identity\n\
  82   -r, --role=ROLE    role\n\
  83   -l, --range=RANGE  levelrange\n\
  84 \n\
  85 "), stdout);
  86       fputs (HELP_OPTION_DESCRIPTION, stdout);
  87       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  88       emit_bug_reporting_address ();
  89     }
  90   exit (status);
  91 }
  92
  93 int
  94 main (int argc, char **argv)
  95 {
  96   char *role = NULL;
  97   char *range = NULL;
  98   char *user = NULL;
  99   char *type = NULL;
 100   char *context = NULL;
 101   security_context_t cur_context = NULL;
 102   security_context_t file_context = NULL;
 103   security_context_t new_context = NULL;
 104   bool compute_trans = false;
 105
 106   context_t con;
 107
 108   initialize_main (&argc, &argv);
 109   program_name = argv[0];
 110   setlocale (LC_ALL, "");
 111   bindtextdomain (PACKAGE, LOCALEDIR);
 112   textdomain (PACKAGE);
 113
 114   atexit (close_stdout);
 115
 116   while (1)
 117     {
 118       int option_index = 0;
 119       int c = getopt_long (argc, argv, "+r:t:u:l:c", long_options,
 120                            &option_index);
 121       if (c == -1)
 122         break;
 123       switch (c)
 124         {
 125         case 'r':
 126           if (role)
 127             error (EXIT_FAILURE, 0, _("multiple roles"));
 128           role = optarg;
 129           break;
 130         case 't':
 131           if (type)
 132             error (EXIT_FAILURE, 0, _("multiple types"));
 133           type = optarg;
 134           break;
 135         case 'u':
 136           if (user)
 137             error (EXIT_FAILURE, 0, _("multiple users"));
 138           user = optarg;
 139           break;
 140         case 'l':
 141           if (range)
 142             error (EXIT_FAILURE, 0, _("multiple levelranges"));
 143           range = optarg;
 144           break;
 145         case 'c':
 146           compute_trans = true;
 147           break;
 148
 149         case_GETOPT_HELP_CHAR;
 150         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 151         default:
 152           usage (EXIT_FAILURE);
 153           break;
 154         }
 155     }
 156
 157   if (argc - optind == 0)
 158     {
 159       if (getcon (&cur_context) < 0)
 160         error (EXIT_FAILURE, errno, _("failed to get current context"));
 161       fputs (cur_context, stdout);
 162       fputc ('\n', stdout);
 163       exit (EXIT_SUCCESS);
 164     }
 165
 166   if (!(user || role || type || range || compute_trans))
 167     {
 168       if (optind >= argc)
 169         {
 170           error (0, 0, _("you must specify -c, -t, -u, -l, -r, or context"));
 171           usage (1);
 172         }
 173       context = argv[optind++];
 174     }
 175
 176   if (optind >= argc)
 177     {
 178       error (0, 0, _("no command specified"));
 179       usage (1);
 180     }
 181
 182   if (is_selinux_enabled () != 1)
 183     error (EXIT_FAILURE, 0,
 184            _("runcon may be used only on a SELinux kernel"));
 185
 186   if (context)
 187     {
 188       con = context_new (context);
 189       if (!con)
 190         error (EXIT_FAILURE, errno, _("failed to create security context: %s"),
 191                quotearg_colon (context));
 192     }
 193   else
 194     {
 195       if (getcon (&cur_context) < 0)
 196         error (EXIT_FAILURE, errno, _("failed to get current context"));
 197
 198       /* We will generate context based on process transition */
 199       if (compute_trans)
 200         {
 201           /* Get context of file to be executed */
 202           if (getfilecon (argv[optind], &file_context) == -1)
 203             error (EXIT_FAILURE, errno,
 204                    _("failed to get security context of %s"),
 205                    quote (argv[optind]));
 206           /* compute result of process transition */
 207           if (security_compute_create (cur_context, file_context,
 208                                        SECCLASS_PROCESS, &new_context) != 0)
 209             error (EXIT_FAILURE, errno,
 210                    _("failed to compute a new context"));
 211           /* free contexts */
 212           freecon (file_context);
 213           freecon (cur_context);
 214
 215           /* set cur_context equal to new_context */
 216           cur_context = new_context;
 217         }
 218
 219       con = context_new (cur_context);
 220       if (!con)
 221         error (EXIT_FAILURE, errno, _("failed to create security context: %s"),
 222                quotearg_colon (cur_context));
 223       if (user && context_user_set (con, user))
 224         error (EXIT_FAILURE, errno, _("failed to set new user %s"), user);
 225       if (type && context_type_set (con, type))
 226         error (EXIT_FAILURE, errno, _("failed to set new type %s"), type);
 227       if (range && context_range_set (con, range))
 228         error (EXIT_FAILURE, errno, _("failed to set new range %s"), range);
 229       if (role && context_role_set (con, role))
 230         error (EXIT_FAILURE, errno, _("failed to set new role %s"), role);
 231     }
 232
 233   if (security_check_context (context_str (con)) < 0)
 234     error (EXIT_FAILURE, errno, _("invalid context: %s"),
 235            quotearg_colon (context_str (con)));
 236
 237   if (setexeccon (context_str (con)) != 0)
 238     error (EXIT_FAILURE, errno, _("unable to set security context %s"),
 239            quote (context_str (con)));
 240   if (cur_context != NULL)
 241     freecon (cur_context);
 242
 243   execvp (argv[optind], argv + optind);
 244
 245   {
 246     int exit_status = (errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE);
 247     error (0, errno, "%s", argv[optind]);
 248     exit (exit_status);
 249   }
 250 }