1 /* setuidgid - run a command with the UID and GID of a specified user
2 Copyright (C) 2003-2008 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 Jim Meyering */
22 #include <sys/types.h>
29 #include "long-options.h"
30 #include "mgetgroups.h"
34 #define PROGRAM_NAME "setuidgid"
36 /* I wrote this program from scratch, based on the description of
37 D.J. Bernstein's program: http://cr.yp.to/daemontools/setuidgid.html. */
38 #define AUTHORS proper_name ("Jim Meyering")
40 #define SETUIDGID_FAILURE 111
45 if (status != EXIT_SUCCESS)
46 fprintf (stderr, _("Try `%s --help' for more information.\n"),
51 Usage: %s OPTION USER COMMAND [ARGUMENT]...\n\
54 program_name, program_name);
57 Drop any supplemental groups, assume the user-ID and group-ID of the specified\n\
58 USER (numeric ID or user name), and run COMMAND with any specified ARGUMENTs.\n\
59 Exit with status 111 if unable to assume the required user and group ID.\n\
60 Otherwise, exit with the exit status of COMMAND.\n\
61 This program is useful only when run by root (user ID zero).\n\
65 -g GID[,GID1...] also set the primary group-ID to the numeric GID, and\n\
66 (if specified) supplemental group IDs to GID1, ...\n\
68 fputs (HELP_OPTION_DESCRIPTION, stdout);
69 fputs (VERSION_OPTION_DESCRIPTION, stdout);
70 emit_bug_reporting_address ();
76 main (int argc, char **argv)
79 GETGROUPS_T *gids = NULL;
81 size_t n_gids_allocated = 0;
84 initialize_main (&argc, &argv);
85 set_program_name (argv[0]);
86 setlocale (LC_ALL, "");
87 bindtextdomain (PACKAGE, LOCALEDIR);
90 initialize_exit_failure (SETUIDGID_FAILURE);
91 atexit (close_stdout);
93 parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE_NAME, VERSION,
94 usage, AUTHORS, (char const *) NULL);
97 while ((c = getopt_long (argc, argv, "+g:", NULL, NULL)) != -1)
103 unsigned long int tmp_ul;
108 if (! (xstrtoul (gr, &ptr, 10, &tmp_ul, NULL) == LONGINT_OK
109 && tmp_ul <= GID_T_MAX))
110 error (EXIT_FAILURE, 0, _("invalid group %s"),
112 if (n_gids == n_gids_allocated)
113 gids = x2nrealloc (gids, &n_gids_allocated, sizeof *gids);
114 gids[n_gids++] = tmp_ul;
120 error (0, 0, _("invalid group %s"), quote (gr));
121 usage (SETUIDGID_FAILURE);
129 usage (SETUIDGID_FAILURE);
134 if (argc <= optind + 1)
136 if (argc < optind + 1)
137 error (0, 0, _("missing operand"));
139 error (0, 0, _("missing operand after %s"), quote (argv[optind]));
140 usage (SETUIDGID_FAILURE);
144 const struct passwd *pwd;
145 unsigned long int tmp_ul;
146 char *user = argv[optind];
148 bool have_uid = false;
150 if (xstrtoul (user, &ptr, 10, &tmp_ul, "") == LONGINT_OK
151 && tmp_ul <= UID_T_MAX)
159 pwd = getpwnam (user);
162 error (SETUIDGID_FAILURE, errno,
163 _("unknown user-ID: %s"), quote (user));
164 usage (SETUIDGID_FAILURE);
168 else if (n_gids == 0)
170 pwd = getpwuid (uid);
173 error (SETUIDGID_FAILURE, errno,
174 _("to use user-ID %s you need to use -g too"), quote (user));
175 usage (SETUIDGID_FAILURE);
182 int n = mgetgroups (pwd->pw_name, pwd->pw_gid, &gids);
184 error (1, errno, _("failed to get groups for user %s"),
185 quote (pwd->pw_name));
189 if (setgroups (n_gids, gids))
190 error (SETUIDGID_FAILURE, errno,
191 _("failed to set supplemental group(s)"));
193 primary_gid = gids[0];
195 primary_gid = pwd->pw_gid;
199 if (setgid (primary_gid))
200 error (SETUIDGID_FAILURE, errno,
201 _("cannot set group-ID to %lu"), (unsigned long int) primary_gid);
204 error (SETUIDGID_FAILURE, errno,
205 _("cannot set user-ID to %lu"), (unsigned long int) uid);
208 char **cmd = argv + optind + 1;
211 exit_status = (errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE);
213 error (0, errno, _("cannot run command %s"), quote (*cmd));
220 * indent-tabs-mode: nil