top: add -m ("memory") option

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

diff --git a/loginutils/su.c b/loginutils/su.c
index e1c1591aa6dab292b9005f476a7eb612877ddd4d..a3f7ed8a08a24f7e883376e4ae381edae870a6ae 100644 (file)
--- a/loginutils/su.c
+++ b/loginutils/su.c
@@ -5,53 +5,63 @@
  *  Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  */
 
-#include "busybox.h"
+#include "libbb.h"
 #include <syslog.h>
 
 #define SU_OPT_mp (3)
 #define SU_OPT_l (4)
 
-int su_main(int argc, char **argv)
+int su_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int su_main(int argc UNUSED_PARAM, char **argv)
 {
        unsigned flags;
-       char *opt_shell = 0;
-       char *opt_command = 0;
-       char *opt_username = "root";
+       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;
 
-       flags = getopt32(argc, argv, "mplc:s:", &opt_command, &opt_shell);
-       argc -= optind;
+       flags = getopt32(argv, "mplc:s:", &opt_command, &opt_shell);
+       //argc -= optind;
        argv += optind;
 
-       if (argc && LONE_DASH(argv[0])) {
+       if (argv[0] && LONE_DASH(argv[0])) {
                flags |= SU_OPT_l;
-               argc--;
                argv++;
        }
 
        /* get user if specified */
-       if (argc) {
+       if (argv[0]) {
                opt_username = argv[0];
-//             argc--;
                argv++;
        }
 
        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.  */
-               old_user = xstrdup(USE_FEATURE_UTMP(getlogin() ? : ) (pw = getpwuid(cur_uid)) ? pw->pw_name : "");
-               tty = ttyname(2) ? : "none";
+                * 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.  */
+               const char *user;
+#if ENABLE_FEATURE_UTMP
+               char user_buf[64];
+               user = user_buf;
+               if (getlogin_r(user_buf, sizeof(user_buf)) != 0)
+#endif
+               {
+                       pw = getpwuid(cur_uid);
+                       user = pw ? pw->pw_name : "";
+               }
+               old_user = xstrdup(user);
+               tty = xmalloc_ttyname(2);
+               if (!tty) {
+                       tty = "none";
+               }
                openlog(applet_name, 0, LOG_AUTH);
        }
 
-       pw = getpwnam(opt_username);
-       if (!pw)
-               bb_error_msg_and_die("unknown id: %s", opt_username);
+       pw = xgetpwnam(opt_username);
 
        /* 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
@@ -85,18 +95,19 @@ int su_main(int argc, char **argv)
                   compromise the account by allowing access with a standard
                   shell.  */
                bb_error_msg("using restricted shell");
-               opt_shell = 0;
+               opt_shell = NULL;
        }
 #endif
        if (!opt_shell)
                opt_shell = pw->pw_shell;
 
        change_identity(pw);
+       /* setup_environment params: shell, clear_env, change_env, pw */
        setup_environment(opt_shell, flags & SU_OPT_l, !(flags & SU_OPT_mp), pw);
-       USE_SELINUX(set_current_security_context(NULL);)
+       IF_SELINUX(set_current_security_context(NULL);)
 
        /* Never returns */
        run_shell(opt_shell, flags & SU_OPT_l, opt_command, (const char**)argv);
 
-       return EXIT_FAILURE;
+       /* return EXIT_FAILURE; - not reached */
 }