/* vi: set sw=4 ts=4: */
/*
- * Mini su implementation for busybox
+ * Mini su implementation for busybox
*
- * Licensed under the GPL v2, see the file LICENSE in this tarball.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
-#include "busybox.h"
-#include <signal.h>
+#include "libbb.h"
#include <syslog.h>
-#include <sys/resource.h>
-#include <time.h>
+#if ENABLE_FEATURE_SU_CHECKS_SHELLS
+/* Return 1 if SHELL is a restricted shell (one not returned by
+ * getusershell), else 0, meaning it is a standard shell. */
+static int restricted_shell(const char *shell)
+{
+ char *line;
+ int result = 1;
+
+ /*setusershell(); - getusershell does it itself*/
+ while ((line = getusershell()) != NULL) {
+ if (/* *line != '#' && */ strcmp(line, shell) == 0) {
+ result = 0;
+ break;
+ }
+ }
+ if (ENABLE_FEATURE_CLEAN_UP)
+ endusershell();
+ return result;
+}
+#endif
-int su_main ( int argc, char **argv )
+#define SU_OPT_mp (3)
+#define SU_OPT_l (4)
+
+int su_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int su_main(int argc UNUSED_PARAM, char **argv)
{
- unsigned long flags;
- char *opt_shell = 0;
- char *opt_command = 0;
- char *opt_username = "root";
- char **opt_args = 0;
+ unsigned flags;
+ char *opt_shell = NULL;
+ char *opt_command = NULL;
+ const char *opt_username = "root";
struct passwd *pw;
uid_t cur_uid = getuid();
const char *tty;
- char *old_user;
+ char user_buf[64];
+ const char *old_user;
- flags = bb_getopt_ulflags(argc, argv, "mplc:s:", &opt_command, &opt_shell);
-#define SU_OPT_mp (3)
-#define SU_OPT_l (4)
+ flags = getopt32(argv, "mplc:s:", &opt_command, &opt_shell);
+ //argc -= optind;
+ argv += optind;
- if (optind < argc && argv[optind][0] == '-' && argv[optind][1] == 0) {
+ if (argv[0] && LONE_DASH(argv[0])) {
flags |= SU_OPT_l;
- ++optind;
- }
+ argv++;
+ }
/* get user if specified */
- if (optind < argc) opt_username = argv [optind++];
-
- if (optind < argc) opt_args = argv + optind;
-
- if (ENABLE_SU_SYSLOG) {
- /* The utmp entry (via getlogin) is probably the best way to identify
- the user, especially if someone su's from a su-shell.
- But getlogin can fail -- usually due to lack of utmp entry.
- in this case resort to getpwuid. */
- old_user = bb_xstrdup(USE_FEATURE_UTMP(getlogin() ? : ) (pw = getpwuid(cur_uid)) ? pw->pw_name : "");
- tty = ttyname(2) ? : "none";
- openlog(bb_applet_name, 0, LOG_AUTH);
+ if (argv[0]) {
+ opt_username = argv[0];
+ argv++;
}
- pw = getpwnam(opt_username);
- if (!pw) bb_error_msg_and_die("Unknown id: %s", opt_username);
+ if (ENABLE_FEATURE_SU_SYSLOG) {
+ /* The utmp entry (via getlogin) is probably the best way to
+ * identify the user, especially if someone su's from a su-shell.
+ * But getlogin can fail -- usually due to lack of utmp entry.
+ * in this case resort to getpwuid. */
+#if ENABLE_FEATURE_UTMP
+ old_user = user_buf;
+ if (getlogin_r(user_buf, sizeof(user_buf)) != 0)
+#endif
+ {
+ pw = getpwuid(cur_uid);
+ old_user = pw ? xstrdup(pw->pw_name) : "";
+ }
+ tty = xmalloc_ttyname(2);
+ if (!tty) {
+ tty = "none";
+ }
+ openlog(applet_name, 0, LOG_AUTH);
+ }
- /* Make sure pw->pw_shell is non-NULL. It may be NULL when NEW_USER
- is a username that is retrieved via NIS (YP), but that doesn't have
- a default shell listed. */
- if (!pw->pw_shell || !pw->pw_shell[0]) pw->pw_shell = (char *)DEFAULT_SHELL;
+ pw = xgetpwnam(opt_username);
- if ((cur_uid == 0) || correct_password(pw)) {
- if (ENABLE_SU_SYSLOG)
- syslog(LOG_NOTICE, "+ %s %s:%s", tty, old_user, opt_username);
+ if (cur_uid == 0 || correct_password(pw)) {
+ if (ENABLE_FEATURE_SU_SYSLOG)
+ syslog(LOG_NOTICE, "%c %s %s:%s",
+ '+', tty, old_user, opt_username);
} else {
- if (ENABLE_SU_SYSLOG)
- syslog(LOG_NOTICE, "- %s %s:%s", tty, old_user, opt_username);
+ if (ENABLE_FEATURE_SU_SYSLOG)
+ syslog(LOG_NOTICE, "%c %s %s:%s",
+ '-', tty, old_user, opt_username);
bb_error_msg_and_die("incorrect password");
}
- if (ENABLE_FEATURE_CLEAN_UP && ENABLE_SU_SYSLOG) {
+ if (ENABLE_FEATURE_CLEAN_UP && ENABLE_FEATURE_SU_SYSLOG) {
closelog();
- free(old_user);
}
- if (!opt_shell && (flags & SU_OPT_mp)) opt_shell = getenv("SHELL");
+ if (!opt_shell && (flags & SU_OPT_mp)) {
+ /* -s SHELL is not given, but "preserve env" opt is */
+ opt_shell = getenv("SHELL");
+ }
+
+ /* Make sure pw->pw_shell is non-NULL. It may be NULL when NEW_USER
+ * is a username that is retrieved via NIS (YP), that doesn't have
+ * a default shell listed. */
+ if (!pw->pw_shell || !pw->pw_shell[0])
+ pw->pw_shell = (char *)DEFAULT_SHELL;
- if (opt_shell && cur_uid && restricted_shell(pw->pw_shell)) {
+#if ENABLE_FEATURE_SU_CHECKS_SHELLS
+ if (opt_shell && cur_uid != 0 && restricted_shell(pw->pw_shell)) {
/* The user being su'd to has a nonstandard shell, and so is
- probably a uucp account or has restricted access. Don't
- compromise the account by allowing access with a standard
- shell. */
+ * probably a uucp account or has restricted access. Don't
+ * compromise the account by allowing access with a standard
+ * shell. */
bb_error_msg("using restricted shell");
- opt_shell = 0;
+ opt_shell = NULL;
}
-
- if (!opt_shell) opt_shell = pw->pw_shell;
+ /* else: user can run whatever he wants via "su -s PROG USER".
+ * This is safe since PROG is run under user's uid/gid. */
+#endif
+ if (!opt_shell)
+ opt_shell = pw->pw_shell;
change_identity(pw);
- setup_environment(opt_shell, flags & SU_OPT_l, !(flags & SU_OPT_mp), pw);
- USE_SELINUX(set_current_security_context(NULL);)
+ setup_environment(opt_shell,
+ ((flags & SU_OPT_l) / SU_OPT_l * SETUP_ENV_CLEARENV)
+ + (!(flags & SU_OPT_mp) * SETUP_ENV_CHANGEENV),
+ pw);
+ IF_SELINUX(set_current_security_context(NULL);)
- /* Returns only on error */
- run_shell(opt_shell, flags & SU_OPT_l, opt_command, (const char**)opt_args);
+ /* Never returns */
+ run_shell(opt_shell, flags & SU_OPT_l, opt_command, (const char**)argv);
- return EXIT_FAILURE;
+ /* return EXIT_FAILURE; - not reached */
}
projects / oweals / busybox.git / blobdiff