1 /* chroot -- run command or shell with special root directory
2 Copyright (C) 1995-1997, 1999-2004, 2007-2010 Free Software Foundation, Inc.
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.
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.
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/>. */
17 /* Written by Roland McGrath. */
22 #include <sys/types.h>
31 /* The official name of this program (e.g., no `g' prefix). */
32 #define PROGRAM_NAME "chroot"
34 #define AUTHORS proper_name ("Roland McGrath")
37 # define MAXGID GID_T_MAX
42 GROUPS
= UCHAR_MAX
+ 1,
46 static struct option
const long_opts
[] =
48 {"groups", required_argument
, NULL
, GROUPS
},
49 {"userspec", required_argument
, NULL
, USERSPEC
},
50 {GETOPT_HELP_OPTION_DECL
},
51 {GETOPT_VERSION_OPTION_DECL
},
55 /* Call setgroups to set the supplementary groups to those listed in GROUPS.
56 GROUPS is a comma separated list of supplementary groups (names or numbers).
57 Parse that list, converting any names to numbers, and call setgroups on the
58 resulting numbers. Upon any failure give a diagnostic and return nonzero.
59 Otherwise return zero. */
61 set_additional_groups (char const *groups
)
63 GETGROUPS_T
*gids
= NULL
;
64 size_t n_gids_allocated
= 0;
66 char *buffer
= xstrdup (groups
);
70 for (tmp
= strtok (buffer
, ","); tmp
; tmp
= strtok (NULL
, ","))
73 unsigned long int value
;
75 if (xstrtoul (tmp
, NULL
, 10, &value
, "") == LONGINT_OK
&& value
<= MAXGID
)
86 error (0, errno
, _("invalid group %s"), quote (tmp
));
91 if (n_gids
== n_gids_allocated
)
92 gids
= X2NREALLOC (gids
, &n_gids_allocated
);
93 gids
[n_gids
++] = value
;
96 if (ret
== 0 && n_gids
== 0)
98 error (0, 0, _("invalid group list %s"), quote (groups
));
104 ret
= setgroups (n_gids
, gids
);
106 error (0, errno
, _("failed to set additional groups"));
117 if (status
!= EXIT_SUCCESS
)
118 fprintf (stderr
, _("Try `%s --help' for more information.\n"),
123 Usage: %s [OPTION] NEWROOT [COMMAND [ARG]...]\n\
125 "), program_name
, program_name
);
128 Run COMMAND with root directory set to NEWROOT.\n\
133 --userspec=USER:GROUP specify user and group (ID or name) to use\n\
134 --groups=G_LIST specify supplementary groups as g1,g2,..,gN\n\
137 fputs (HELP_OPTION_DESCRIPTION
, stdout
);
138 fputs (VERSION_OPTION_DESCRIPTION
, stdout
);
141 If no command is given, run ``${SHELL} -i'' (default: /bin/sh).\n\
143 emit_ancillary_info ();
149 main (int argc
, char **argv
)
152 char const *userspec
= NULL
;
153 char const *groups
= NULL
;
155 initialize_main (&argc
, &argv
);
156 set_program_name (argv
[0]);
157 setlocale (LC_ALL
, "");
158 bindtextdomain (PACKAGE
, LOCALEDIR
);
159 textdomain (PACKAGE
);
161 initialize_exit_failure (EXIT_CANCELED
);
162 atexit (close_stdout
);
164 while ((c
= getopt_long (argc
, argv
, "+", long_opts
, NULL
)) != -1)
176 case_GETOPT_HELP_CHAR
;
178 case_GETOPT_VERSION_CHAR (PROGRAM_NAME
, AUTHORS
);
181 usage (EXIT_CANCELED
);
187 error (0, 0, _("missing operand"));
188 usage (EXIT_CANCELED
);
191 if (chroot (argv
[optind
]) != 0)
192 error (EXIT_CANCELED
, errno
, _("cannot change root directory to %s"),
196 error (EXIT_CANCELED
, errno
, _("cannot chdir to root directory"));
198 if (argc
== optind
+ 1)
200 /* No command. Run an interactive shell. */
201 char *shell
= getenv ("SHELL");
203 shell
= bad_cast ("/bin/sh");
205 argv
[1] = bad_cast ("-i");
210 /* The following arguments give the command. */
216 /* Attempt to set all three: supplementary groups, group ID, user ID.
217 Diagnose any failures. If any have failed, exit before execvp. */
224 char const *err
= parse_user_spec (userspec
, &uid
, &gid
, &user
, &group
);
227 error (EXIT_CANCELED
, errno
, "%s", err
);
232 if (groups
&& set_additional_groups (groups
))
235 if (gid
!= (gid_t
) -1 && setgid (gid
))
237 error (0, errno
, _("failed to set group-ID"));
241 if (uid
!= (uid_t
) -1 && setuid (uid
))
243 error (0, errno
, _("failed to set user-ID"));
249 /* Yes, this call is identical to the one above.
250 However, when --userspec and --groups groups are used together,
251 we don't want to call this function until after parsing USER:GROUP,
252 and it must be called before setuid. */
253 if (groups
&& set_additional_groups (groups
))
258 exit (EXIT_CANCELED
);
260 /* Execute the given command. */
261 execvp (argv
[0], argv
);
264 int exit_status
= (errno
== ENOENT
? EXIT_ENOENT
: EXIT_CANNOT_INVOKE
);
265 error (0, errno
, _("failed to run command %s"), quote (argv
[0]));