udhcpc: fix a problem with binary-encoded options #2

[oweals/busybox.git] / loginutils / su.c

diff --git a/loginutils/su.c b/loginutils/su.c
index 9bae375515105266de781d459ad60fcaed08717b..2ec05e12552e04588cc92be1f45d9ef337fd1fb0 100644 (file)
--- a/loginutils/su.c
+++ b/loginutils/su.c
@@ -1,13 +1,22 @@
 /* vi: set sw=4 ts=4: */
 /*
- *  Mini su implementation for busybox
+ * Mini su implementation for busybox
  *
- *  Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
 #include "libbb.h"
 #include <syslog.h>
 
+//usage:#define su_trivial_usage
+//usage:       "[OPTIONS] [-] [USER]"
+//usage:#define su_full_usage "\n\n"
+//usage:       "Run shell under USER (by default, root)\n"
+//usage:     "\n       -,-l    Clear environment, run shell as login shell"
+//usage:     "\n       -p,-m   Do not set new $HOME, $SHELL, $USER, $LOGNAME"
+//usage:     "\n       -c CMD  Command to pass to 'sh -c'"
+//usage:     "\n       -s SH   Shell to use instead of user's default"
+
 #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.  */
@@ -42,7 +51,9 @@ int su_main(int argc UNUSED_PARAM, char **argv)
        struct passwd *pw;
        uid_t cur_uid = getuid();
        const char *tty;
+#if ENABLE_FEATURE_UTMP
        char user_buf[64];
+#endif
        const char *old_user;
 
        flags = getopt32(argv, "mplc:s:", &opt_command, &opt_shell);
@@ -102,20 +113,14 @@ int su_main(int argc UNUSED_PARAM, char **argv)
                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 ENABLE_FEATURE_SU_CHECKS_SHELLS
-       if (opt_shell && cur_uid != 0 && restricted_shell(pw->pw_shell)) {
+       if (opt_shell && cur_uid != 0 && pw->pw_shell && 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.  */
                bb_error_msg("using restricted shell");
-               opt_shell = NULL;
+               opt_shell = NULL; /* ignore -s PROG */
        }
        /* else: user can run whatever he wants via "su -s PROG USER".
         * This is safe since PROG is run under user's uid/gid. */
@@ -126,7 +131,8 @@ int su_main(int argc UNUSED_PARAM, char **argv)
        change_identity(pw);
        setup_environment(opt_shell,
                        ((flags & SU_OPT_l) / SU_OPT_l * SETUP_ENV_CLEARENV)
-                       + (!(flags & SU_OPT_mp) * SETUP_ENV_CHANGEENV),
+                       + (!(flags & SU_OPT_mp) * SETUP_ENV_CHANGEENV)
+                       + (!(flags & SU_OPT_l) * SETUP_ENV_NO_CHDIR),
                        pw);
        IF_SELINUX(set_current_security_context(NULL);)