1 /* vi: set sw=4 ts=4: */
3 * Mini su implementation for busybox
5 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
14 int su_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
15 int su_main(int argc UNUSED_PARAM, char **argv)
18 char *opt_shell = NULL;
19 char *opt_command = NULL;
20 const char *opt_username = "root";
22 uid_t cur_uid = getuid();
26 flags = getopt32(argv, "mplc:s:", &opt_command, &opt_shell);
30 if (argv[0] && LONE_DASH(argv[0])) {
35 /* get user if specified */
37 opt_username = argv[0];
41 if (ENABLE_FEATURE_SU_SYSLOG) {
42 /* The utmp entry (via getlogin) is probably the best way to identify
43 the user, especially if someone su's from a su-shell.
44 But getlogin can fail -- usually due to lack of utmp entry.
45 in this case resort to getpwuid. */
46 old_user = xstrdup(USE_FEATURE_UTMP(getlogin() ? : ) (pw = getpwuid(cur_uid)) ? pw->pw_name : "");
47 tty = ttyname(2) ? : "none";
48 openlog(applet_name, 0, LOG_AUTH);
51 pw = getpwnam(opt_username);
53 bb_error_msg_and_die("unknown id: %s", opt_username);
55 /* Make sure pw->pw_shell is non-NULL. It may be NULL when NEW_USER
56 is a username that is retrieved via NIS (YP), but that doesn't have
57 a default shell listed. */
58 if (!pw->pw_shell || !pw->pw_shell[0])
59 pw->pw_shell = (char *)DEFAULT_SHELL;
61 if ((cur_uid == 0) || correct_password(pw)) {
62 if (ENABLE_FEATURE_SU_SYSLOG)
63 syslog(LOG_NOTICE, "%c %s %s:%s",
64 '+', tty, old_user, opt_username);
66 if (ENABLE_FEATURE_SU_SYSLOG)
67 syslog(LOG_NOTICE, "%c %s %s:%s",
68 '-', tty, old_user, opt_username);
69 bb_error_msg_and_die("incorrect password");
72 if (ENABLE_FEATURE_CLEAN_UP && ENABLE_FEATURE_SU_SYSLOG) {
77 if (!opt_shell && (flags & SU_OPT_mp))
78 opt_shell = getenv("SHELL");
80 #if ENABLE_FEATURE_SU_CHECKS_SHELLS
81 if (opt_shell && cur_uid && restricted_shell(pw->pw_shell)) {
82 /* The user being su'd to has a nonstandard shell, and so is
83 probably a uucp account or has restricted access. Don't
84 compromise the account by allowing access with a standard
86 bb_error_msg("using restricted shell");
91 opt_shell = pw->pw_shell;
94 /* setup_environment params: shell, clear_env, change_env, pw */
95 setup_environment(opt_shell, flags & SU_OPT_l, !(flags & SU_OPT_mp), pw);
96 USE_SELINUX(set_current_security_context(NULL);)
99 run_shell(opt_shell, flags & SU_OPT_l, opt_command, (const char**)argv);
101 /* return EXIT_FAILURE; - not reached */