/* vi: set sw=4 ts=4: */
+/*
+ * Mini su implementation for busybox
+ *
+ * Licensed under the GPL v2, see the file LICENSE in this tarball.
+ */
-#include <fcntl.h>
+#include "busybox.h"
#include <signal.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
#include <syslog.h>
-#include <termios.h>
-#include <unistd.h>
-#include <utmp.h>
#include <sys/resource.h>
-#include <sys/stat.h>
-#include <sys/time.h>
-#include <sys/types.h>
-#include <ctype.h>
#include <time.h>
-#include "busybox.h"
-
-
-
-/* The shell to run if none is given in the user's passwd entry. */
-#define DEFAULT_SHELL "/bin/sh"
-#define DEFAULT_USER "root"
-
-//#define SYSLOG_SUCCESS
-#define SYSLOG_FAILURE
-
-
-#if defined( SYSLOG_SUCCESS ) || defined( SYSLOG_FAILURE )
-/* Log the fact that someone has run su to the user given by PW;
- if SUCCESSFUL is nonzero, they gave the correct password, etc. */
-
-static void log_su ( const struct passwd *pw, int successful )
-{
- const char *old_user, *tty;
-
-#if !defined( SYSLOG_SUCESS )
- if ( successful )
- return;
-#endif
-#if !defined( SYSLOG_FAILURE )
- if ( !successful )
- return;
-#endif
-
- if ( pw-> pw_uid ) // not to root -> ignored
- return;
-
- /* The utmp entry (via getlogin) is probably the best way to identify
- the user, especially if someone su's from a su-shell. */
- old_user = getlogin ( );
- if ( !old_user ) {
- /* getlogin can fail -- usually due to lack of utmp entry. Resort to getpwuid. */
- struct passwd *pwd = getpwuid ( getuid ( ));
- old_user = ( pwd ? pwd-> pw_name : "" );
- }
-
- tty = ttyname ( 2 );
-
- openlog ( "su", 0, LOG_AUTH );
- syslog ( LOG_NOTICE, "%s%s on %s", successful ? "" : "FAILED SU ", old_user, tty ? tty : "none" );
-}
-#endif
-
-
int su_main ( int argc, char **argv )
{
- int flag;
- int opt_preserve = 0;
- int opt_loginshell = 0;
+ unsigned long flags;
char *opt_shell = 0;
char *opt_command = 0;
- char *opt_username = DEFAULT_USER;
+ char *opt_username = "root";
char **opt_args = 0;
- struct passwd *pw, pw_copy;
-
-
- while (( flag = getopt ( argc, argv, "c:lmps:" )) != -1 ) {
- switch ( flag ) {
- case 'c':
- opt_command = optarg;
- break;
- case 'm':
- case 'p':
- opt_preserve = 1;
- break;
- case 's':
- opt_shell = optarg;
- break;
- case 'l':
- opt_loginshell = 1;
- break;
- default:
- show_usage ( );
- break;
- }
- }
+ struct passwd *pw;
+ uid_t cur_uid = getuid();
+ const char *tty;
+ 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)
- if (( optind < argc ) && ( argv [optind][0] == '-' ) && ( argv [optind][1] == 0 )) {
- opt_loginshell = 1;
+ if (optind < argc && argv[optind][0] == '-' && argv[optind][1] == 0) {
+ flags |= SU_OPT_l;
++optind;
}
/* get user if specified */
- if ( optind < argc )
- opt_username = argv [optind++];
-
- if ( optind < argc )
- opt_args = argv + optind;
-
-
- pw = getpwnam ( opt_username );
- if ( !pw )
- error_msg_and_die ( "user %s does not exist", opt_username );
-
+ 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);
+ }
+
+ pw = getpwnam(opt_username);
+ if (!pw) bb_error_msg_and_die("Unknown id: %s", 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
a default shell listed. */
- if ( !pw-> pw_shell || !pw->pw_shell [0] )
- pw-> pw_shell = (char *) DEFAULT_SHELL;
-
- /* Make a copy of the password information and point pw at the local
- copy instead. Otherwise, some systems (e.g. Linux) would clobber
- the static data through the getlogin call from log_su. */
- pw_copy = *pw;
- pw = &pw_copy;
- pw-> pw_name = xstrdup ( pw-> pw_name );
- pw-> pw_dir = xstrdup ( pw-> pw_dir );
- pw-> pw_shell = xstrdup ( pw-> pw_shell );
-
- if (( getuid ( ) == 0 ) || correct_password ( pw ))
- log_su ( pw, 1 );
- else {
- log_su ( pw, 0 );
- error_msg_and_die ( "incorrect password" );
+ if (!pw->pw_shell || !pw->pw_shell[0]) pw->pw_shell = (char *)DEFAULT_SHELL;
+
+ if ((cur_uid == 0) || correct_password(pw)) {
+ if (ENABLE_SU_SYSLOG)
+ syslog(LOG_NOTICE, "+ %s %s:%s", tty, old_user, opt_username);
+ } else {
+ if (ENABLE_SU_SYSLOG)
+ syslog(LOG_NOTICE, "- %s %s:%s", tty, old_user, opt_username);
+ bb_error_msg_and_die("incorrect password");
+ }
+
+ if (ENABLE_FEATURE_CLEAN_UP && ENABLE_SU_SYSLOG) {
+ closelog();
+ free(old_user);
}
- if ( !opt_shell && opt_preserve )
- opt_shell = getenv ( "SHELL" );
+ if (!opt_shell && (flags & SU_OPT_mp)) opt_shell = getenv("SHELL");
- if ( opt_shell && getuid ( ) && restricted_shell ( pw-> pw_shell ))
- {
+ if (opt_shell && cur_uid && 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. */
- fputs ( "using restricted shell\n", stderr );
+ bb_error_msg("using restricted shell");
opt_shell = 0;
}
- if ( !opt_shell )
- opt_shell = xstrdup ( pw-> pw_shell );
+ 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);)
+
+ /* Never returns */
+ run_shell(opt_shell, flags & SU_OPT_l, opt_command, (const char**)opt_args);
- change_identity ( pw );
- setup_environment ( opt_shell, opt_loginshell, !opt_preserve, pw );
- run_shell ( opt_shell, opt_loginshell, opt_command, (const char**)opt_args );
-
return EXIT_FAILURE;
}
projects / oweals / busybox.git / blobdiff