src/runcon.c

   1 /* runcon -- run command with specified security context
   2    Copyright (C) 2005-2012 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 /*
  18  * runcon [ context |
  19  *         ( [ -c ] [ -r role ] [-t type] [ -u user ] [ -l levelrange ] )
  20  *         command [arg1 [arg2 ...] ]
  21  *
  22  * attempt to run the specified command with the specified context.
  23  *
  24  * -r role  : use the current context with the specified role
  25  * -t type  : use the current context with the specified type
  26  * -u user  : use the current context with the specified user
  27  * -l level : use the current context with the specified level range
  28  * -c       : compute process transition context before modifying
  29  *
  30  * Contexts are interpreted as follows:
  31  *
  32  * Number of       MLS
  33  * components    system?
  34  *
  35  *     1            -         type
  36  *     2            -         role:type
  37  *     3            Y         role:type:range
  38  *     3            N         user:role:type
  39  *     4            Y         user:role:type:range
  40  *     4            N         error
  41  */
  42
  43 #include <config.h>
  44 #include <stdio.h>
  45 #include <getopt.h>
  46 #include <selinux/selinux.h>
  47 #include <selinux/context.h>
  48 #ifdef HAVE_SELINUX_FLASK_H
  49 # include <selinux/flask.h>
  50 #else
  51 # define SECCLASS_PROCESS 0
  52 #endif
  53 #include <sys/types.h>
  54 #include "system.h"
  55 #include "error.h"
  56 #include "quote.h"
  57 #include "quotearg.h"
  58
  59 /* The official name of this program (e.g., no 'g' prefix).  */
  60 #define PROGRAM_NAME "runcon"
  61
  62 #define AUTHORS proper_name ("Russell Coker")
  63
  64 static struct option const long_options[] =
  65 {
  66   {"role", required_argument, NULL, 'r'},
  67   {"type", required_argument, NULL, 't'},
  68   {"user", required_argument, NULL, 'u'},
  69   {"range", required_argument, NULL, 'l'},
  70   {"compute", no_argument, NULL, 'c'},
  71   {GETOPT_HELP_OPTION_DECL},
  72   {GETOPT_VERSION_OPTION_DECL},
  73   {NULL, 0, NULL, 0}
  74 };
  75
  76 void
  77 usage (int status)
  78 {
  79   if (status != EXIT_SUCCESS)
  80     emit_try_help ();
  81   else
  82     {
  83       printf (_("\
  84 Usage: %s CONTEXT COMMAND [args]\n\
  85   or:  %s [ -c ] [-u USER] [-r ROLE] [-t TYPE] [-l RANGE] COMMAND [args]\n\
  86 "), program_name, program_name);
  87       fputs (_("\
  88 Run a program in a different security context.\n\
  89 With neither CONTEXT nor COMMAND, print the current security context.\n\
  90 \n\
  91   CONTEXT            Complete security context\n\
  92   -c, --compute      compute process transition context before modifying\n\
  93   -t, --type=TYPE    type (for same role as parent)\n\
  94   -u, --user=USER    user identity\n\
  95   -r, --role=ROLE    role\n\
  96   -l, --range=RANGE  levelrange\n\
  97 \n\
  98 "), stdout);
  99       fputs (HELP_OPTION_DESCRIPTION, stdout);
 100       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 101       emit_ancillary_info ();
 102     }
 103   exit (status);
 104 }
 105
 106 int
 107 main (int argc, char **argv)
 108 {
 109   char *role = NULL;
 110   char *range = NULL;
 111   char *user = NULL;
 112   char *type = NULL;
 113   char *context = NULL;
 114   security_context_t cur_context = NULL;
 115   security_context_t file_context = NULL;
 116   security_context_t new_context = NULL;
 117   bool compute_trans = false;
 118
 119   context_t con;
 120
 121   initialize_main (&argc, &argv);
 122   set_program_name (argv[0]);
 123   setlocale (LC_ALL, "");
 124   bindtextdomain (PACKAGE, LOCALEDIR);
 125   textdomain (PACKAGE);
 126
 127   atexit (close_stdout);
 128
 129   while (1)
 130     {
 131       int option_index = 0;
 132       int c = getopt_long (argc, argv, "+r:t:u:l:c", long_options,
 133                            &option_index);
 134       if (c == -1)
 135         break;
 136       switch (c)
 137         {
 138         case 'r':
 139           if (role)
 140             error (EXIT_FAILURE, 0, _("multiple roles"));
 141           role = optarg;
 142           break;
 143         case 't':
 144           if (type)
 145             error (EXIT_FAILURE, 0, _("multiple types"));
 146           type = optarg;
 147           break;
 148         case 'u':
 149           if (user)
 150             error (EXIT_FAILURE, 0, _("multiple users"));
 151           user = optarg;
 152           break;
 153         case 'l':
 154           if (range)
 155             error (EXIT_FAILURE, 0, _("multiple levelranges"));
 156           range = optarg;
 157           break;
 158         case 'c':
 159           compute_trans = true;
 160           break;
 161
 162         case_GETOPT_HELP_CHAR;
 163         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 164         default:
 165           usage (EXIT_FAILURE);
 166           break;
 167         }
 168     }
 169
 170   if (argc - optind == 0)
 171     {
 172       if (getcon (&cur_context) < 0)
 173         error (EXIT_FAILURE, errno, _("failed to get current context"));
 174       fputs (cur_context, stdout);
 175       fputc ('\n', stdout);
 176       exit (EXIT_SUCCESS);
 177     }
 178
 179   if (!(user || role || type || range || compute_trans))
 180     {
 181       if (optind >= argc)
 182         {
 183           error (0, 0, _("you must specify -c, -t, -u, -l, -r, or context"));
 184           usage (EXIT_FAILURE);
 185         }
 186       context = argv[optind++];
 187     }
 188
 189   if (optind >= argc)
 190     {
 191       error (0, 0, _("no command specified"));
 192       usage (EXIT_FAILURE);
 193     }
 194
 195   if (is_selinux_enabled () != 1)
 196     error (EXIT_FAILURE, 0,
 197            _("%s may be used only on a SELinux kernel"), program_name);
 198
 199   if (context)
 200     {
 201       con = context_new (context);
 202       if (!con)
 203         error (EXIT_FAILURE, errno, _("failed to create security context: %s"),
 204                quotearg_colon (context));
 205     }
 206   else
 207     {
 208       if (getcon (&cur_context) < 0)
 209         error (EXIT_FAILURE, errno, _("failed to get current context"));
 210
 211       /* We will generate context based on process transition */
 212       if (compute_trans)
 213         {
 214           /* Get context of file to be executed */
 215           if (getfilecon (argv[optind], &file_context) == -1)
 216             error (EXIT_FAILURE, errno,
 217                    _("failed to get security context of %s"),
 218                    quote (argv[optind]));
 219           /* compute result of process transition */
 220           if (security_compute_create (cur_context, file_context,
 221                                        SECCLASS_PROCESS, &new_context) != 0)
 222             error (EXIT_FAILURE, errno,
 223                    _("failed to compute a new context"));
 224           /* free contexts */
 225           freecon (file_context);
 226           freecon (cur_context);
 227
 228           /* set cur_context equal to new_context */
 229           cur_context = new_context;
 230         }
 231
 232       con = context_new (cur_context);
 233       if (!con)
 234         error (EXIT_FAILURE, errno, _("failed to create security context: %s"),
 235                quotearg_colon (cur_context));
 236       if (user && context_user_set (con, user))
 237         error (EXIT_FAILURE, errno, _("failed to set new user %s"), user);
 238       if (type && context_type_set (con, type))
 239         error (EXIT_FAILURE, errno, _("failed to set new type %s"), type);
 240       if (range && context_range_set (con, range))
 241         error (EXIT_FAILURE, errno, _("failed to set new range %s"), range);
 242       if (role && context_role_set (con, role))
 243         error (EXIT_FAILURE, errno, _("failed to set new role %s"), role);
 244     }
 245
 246   if (security_check_context (context_str (con)) < 0)
 247     error (EXIT_FAILURE, errno, _("invalid context: %s"),
 248            quotearg_colon (context_str (con)));
 249
 250   if (setexeccon (context_str (con)) != 0)
 251     error (EXIT_FAILURE, errno, _("unable to set security context %s"),
 252            quote (context_str (con)));
 253   if (cur_context != NULL)
 254     freecon (cur_context);
 255
 256   execvp (argv[optind], argv + optind);
 257
 258   {
 259     int exit_status = (errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE);
 260     error (0, errno, "%s", argv[optind]);
 261     exit (exit_status);
 262   }
 263 }