1 files changed, 129 insertions, 0 deletions
diff --git a/src/setuidgid.c b/src/setuidgid.c
new file mode 100644
index 0000000..3a51225
--- /dev/null
+++ b/src/setuidgid.c
@@ -0,0 +1,129 @@
+/* setuidgid - run a command with the UID and GID of a specified user
+   Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Jim Meyering  */
+
+#include <config.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <pwd.h>
+#include <grp.h>
+
+#include "system.h"
+
+#include "error.h"
+#include "long-options.h"
+#include "quote.h"
+
+#define PROGRAM_NAME "setuidgid"
+
+/* I wrote this program from scratch, based on the description of
+   D.J. Bernstein's program: http://cr.yp.to/daemontools/setuidgid.html.  */
+#define AUTHORS "Jim Meyering"
+
+#define SETUIDGID_FAILURE 111
+
+char *program_name;
+
+void
+usage (int status)
+{
+  if (status != EXIT_SUCCESS)
+    fprintf (stderr, _("Try `%s --help' for more information.\n"),
+	     program_name);
+  else
+    {
+      printf (_("\
+Usage: %s USERNAME COMMAND [ARGUMENT]...\n\
+  or:  %s OPTION\n\
+"),
+	      program_name, program_name);
+
+      fputs (_("\
+Drop any supplemental groups, assume the user-ID and group-ID of\n\
+the specified USERNAME, and run COMMAND with any specified ARGUMENTs.\n\
+Exit with status 111 if unable to assume the required user and group ID.\n\
+Otherwise, exit with the exit status of COMMAND.\n\
+This program is useful only when run by root (user ID zero).\n\
+\n\
+"), stdout);
+      fputs (HELP_OPTION_DESCRIPTION, stdout);
+      fputs (VERSION_OPTION_DESCRIPTION, stdout);
+      printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
+    }
+  exit (status);
+}
+
+int
+main (int argc, char **argv)
+{
+  char const *user_id;
+  struct passwd *pwd;
+
+  initialize_main (&argc, &argv);
+  program_name = argv[0];
+  setlocale (LC_ALL, "");
+  bindtextdomain (PACKAGE, LOCALEDIR);
+  textdomain (PACKAGE);
+
+  initialize_exit_failure (SETUIDGID_FAILURE);
+  atexit (close_stdout);
+
+  parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
+		      usage, AUTHORS, (char const *) NULL);
+  if (getopt_long (argc, argv, "+", NULL, NULL) != -1)
+    usage (SETUIDGID_FAILURE);
+
+  if (argc <= optind + 1)
+    {
+      if (argc < optind + 1)
+	error (0, 0, _("missing operand"));
+      else
+	error (0, 0, _("missing operand after %s"), quote (argv[optind]));
+      usage (SETUIDGID_FAILURE);
+    }
+
+  user_id = argv[optind];
+  pwd = getpwnam (user_id);
+  if (pwd == NULL)
+    error (SETUIDGID_FAILURE, errno,
+	   _("unknown user-ID: %s"), quote (user_id));
+
+#if HAVE_SETGROUPS
+  if (setgroups (1, &pwd->pw_gid))
+    error (SETUIDGID_FAILURE, errno, _("cannot set supplemental group"));
+#endif
+
+  if (setgid (pwd->pw_gid))
+    error (SETUIDGID_FAILURE, errno,
+	   _("cannot set group-ID to %lu"), (unsigned long int) pwd->pw_gid);
+
+  if (setuid (pwd->pw_uid))
+    error (SETUIDGID_FAILURE, errno,
+	   _("cannot set user-ID to %lu"), (unsigned long int) pwd->pw_uid);
+
+  {
+    char **cmd = argv + optind + 1;
+    int exit_status;
+    execvp (*cmd, cmd);
+    exit_status = (errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE);
+
+    error (0, errno, _("cannot run command %s"), quote (*cmd));
+    exit (exit_status);
+  }
+}