src/mkfifo.c

   1 /* mkfifo -- make fifo's (named pipes)
   2    Copyright (C) 1990-2024 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 <https://www.gnu.org/licenses/>.  */
  16
  17 /* David MacKenzie <djm@ai.mit.edu>  */
  18
  19 #include <config.h>
  20 #include <stdio.h>
  21 #include <getopt.h>
  22 #include <sys/types.h>
  23 #include <selinux/label.h>
  24
  25 #include "system.h"
  26 #include "modechange.h"
  27 #include "quote.h"
  28 #include "selinux.h"
  29 #include "smack.h"
  30
  31 /* The official name of this program (e.g., no 'g' prefix).  */
  32 #define PROGRAM_NAME "mkfifo"
  33
  34 #define AUTHORS proper_name ("David MacKenzie")
  35
  36 static struct option const longopts[] =
  37 {
  38   {GETOPT_SELINUX_CONTEXT_OPTION_DECL},
  39   {"mode", required_argument, nullptr, 'm'},
  40   {GETOPT_HELP_OPTION_DECL},
  41   {GETOPT_VERSION_OPTION_DECL},
  42   {nullptr, 0, nullptr, 0}
  43 };
  44
  45 void
  46 usage (int status)
  47 {
  48   if (status != EXIT_SUCCESS)
  49     emit_try_help ();
  50   else
  51     {
  52       printf (_("Usage: %s [OPTION]... NAME...\n"), program_name);
  53       fputs (_("\
  54 Create named pipes (FIFOs) with the given NAMEs.\n\
  55 "), stdout);
  56
  57       emit_mandatory_arg_note ();
  58
  59       fputs (_("\
  60   -m, --mode=MODE    set file permission bits to MODE, not a=rw - umask\n\
  61 "), stdout);
  62       fputs (_("\
  63   -Z                   set the SELinux security context to default type\n\
  64       --context[=CTX]  like -Z, or if CTX is specified then set the SELinux\n\
  65                          or SMACK security context to CTX\n\
  66 "), stdout);
  67       fputs (HELP_OPTION_DESCRIPTION, stdout);
  68       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  69       emit_ancillary_info (PROGRAM_NAME);
  70     }
  71   exit (status);
  72 }
  73
  74 int
  75 main (int argc, char **argv)
  76 {
  77   mode_t newmode;
  78   char const *specified_mode = nullptr;
  79   int exit_status = EXIT_SUCCESS;
  80   int optc;
  81   char const *scontext = nullptr;
  82   struct selabel_handle *set_security_context = nullptr;
  83
  84   initialize_main (&argc, &argv);
  85   set_program_name (argv[0]);
  86   setlocale (LC_ALL, "");
  87   bindtextdomain (PACKAGE, LOCALEDIR);
  88   textdomain (PACKAGE);
  89
  90   atexit (close_stdout);
  91
  92   while ((optc = getopt_long (argc, argv, "m:Z", longopts, nullptr)) != -1)
  93     {
  94       switch (optc)
  95         {
  96         case 'm':
  97           specified_mode = optarg;
  98           break;
  99         case 'Z':
 100           if (is_smack_enabled ())
 101             {
 102               /* We don't yet support -Z to restore context with SMACK.  */
 103               scontext = optarg;
 104             }
 105           else if (is_selinux_enabled () > 0)
 106             {
 107               if (optarg)
 108                 scontext = optarg;
 109               else
 110                 {
 111                   set_security_context = selabel_open (SELABEL_CTX_FILE,
 112                                                        nullptr, 0);
 113                   if (! set_security_context)
 114                     error (0, errno, _("warning: ignoring --context"));
 115                 }
 116             }
 117           else if (optarg)
 118             {
 119               error (0, 0,
 120                      _("warning: ignoring --context; "
 121                        "it requires an SELinux/SMACK-enabled kernel"));
 122             }
 123           break;
 124         case_GETOPT_HELP_CHAR;
 125         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 126         default:
 127           usage (EXIT_FAILURE);
 128         }
 129     }
 130
 131   if (optind == argc)
 132     {
 133       error (0, 0, _("missing operand"));
 134       usage (EXIT_FAILURE);
 135     }
 136
 137   if (scontext)
 138     {
 139       int ret = 0;
 140       if (is_smack_enabled ())
 141         ret = smack_set_label_for_self (scontext);
 142       else
 143         ret = setfscreatecon (scontext);
 144
 145       if (ret < 0)
 146         error (EXIT_FAILURE, errno,
 147                _("failed to set default file creation context to %s"),
 148                quote (scontext));
 149     }
 150
 151   newmode = MODE_RW_UGO;
 152   if (specified_mode)
 153     {
 154       mode_t umask_value;
 155       struct mode_change *change = mode_compile (specified_mode);
 156       if (!change)
 157         error (EXIT_FAILURE, 0, _("invalid mode"));
 158       umask_value = umask (0);
 159       umask (umask_value);
 160       newmode = mode_adjust (newmode, false, umask_value, change, nullptr);
 161       free (change);
 162       if (newmode & ~S_IRWXUGO)
 163         error (EXIT_FAILURE, 0,
 164                _("mode must specify only file permission bits"));
 165     }
 166
 167   for (; optind < argc; ++optind)
 168     {
 169       if (set_security_context)
 170         defaultcon (set_security_context, argv[optind], S_IFIFO);
 171       if (mkfifo (argv[optind], newmode) != 0)
 172         {
 173           error (0, errno, _("cannot create fifo %s"), quoteaf (argv[optind]));
 174           exit_status = EXIT_FAILURE;
 175         }
 176       else if (specified_mode && lchmod (argv[optind], newmode) != 0)
 177         {
 178           error (0, errno, _("cannot set permissions of %s"),
 179                  quoteaf (argv[optind]));
 180           exit_status = EXIT_FAILURE;
 181         }
 182     }
 183
 184   return exit_status;
 185 }