diff options
Diffstat (limited to 'loginutils/su.c')
-rw-r--r-- | loginutils/su.c | 154 |
1 files changed, 43 insertions, 111 deletions
diff --git a/loginutils/su.c b/loginutils/su.c index 1273831ff..bd3e7c566 100644 --- a/loginutils/su.c +++ b/loginutils/su.c @@ -1,86 +1,31 @@ /* vi: set sw=4 ts=4: */ /* - Licensed under the GPL v2, see the file LICENSE in this tarball. -*/ + * 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/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. */ -#ifndef DEFAULT_SHELL -#define DEFAULT_SHELL "/bin/sh" -#endif - -/* Default user. */ -#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 */ - -# if defined( SYSLOG_SUCCESS ) && defined( SYSLOG_FAILURE ) -static void log_su (const char *successful, const char *old_user, - const char *tty) -{ - syslog ( LOG_NOTICE, "%s%s on %s", successful, old_user, tty); -} -# define log_su_successful(cu, u, tty) if(!cu) log_su("", u, tty) -# define log_su_failure(cu, u, tty) if(!cu) log_su("FAILED SU ", u, tty) -# else - /* partial logging */ -# if !defined( SYSLOG_SUCESS ) -# define log_su_successful(cu, u, tty) -# define log_su_failure(cu, u, t) if(!cu) \ - syslog(LOG_NOTICE, "FAILED SU %s on %s", u, t) -# else -# define log_su_successful(cu, u, t) if(!cu) \ - syslog(LOG_NOTICE, "%s on %s", u, t) -# define log_su_failure(cu, u, tty) -# endif -# endif -#else - /* logging not used */ -# define log_su_successful(cu, u, tty) -# define log_su_failure(cu, u, tty) -#endif - int su_main ( int argc, char **argv ) { 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; uid_t cur_uid = getuid(); - -#if defined( SYSLOG_SUCCESS ) || defined( SYSLOG_FAILURE ) const char *tty; - const char *old_user; -#endif + char *old_user; - flags = bb_getopt_ulflags(argc, argv, "mplc:s:", - &opt_command, &opt_shell); -#define SU_OPT_m (3) -#define SU_OPT_p (3) + 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) { @@ -89,73 +34,60 @@ int su_main ( int argc, char **argv ) } /* get user if specified */ - if ( optind < argc ) - opt_username = argv [optind++]; - - if ( optind < argc ) - opt_args = argv + optind; - -#if defined( SYSLOG_SUCCESS ) || defined( SYSLOG_FAILURE ) -#ifdef CONFIG_FEATURE_UTMP - /* 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 ) -#endif - { - /* getlogin can fail -- usually due to lack of utmp entry. - Resort to getpwuid. */ - pw = getpwuid ( cur_uid ); - old_user = ( pw ? pw->pw_name : "" ); + 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); } - tty = ttyname ( 2 ); - if(!tty) - tty = "none"; - openlog ( bb_applet_name, 0, LOG_AUTH ); -#endif - - pw = getpwnam ( opt_username ); - if ( !pw ) - bb_error_msg_and_die ( "user %s does not exist", opt_username ); + 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; + if (!pw->pw_shell || !pw->pw_shell[0]) pw->pw_shell = (char *)DEFAULT_SHELL; - if ((( cur_uid == 0 ) || correct_password ( pw ))) { - log_su_successful(pw->pw_uid, old_user, tty ); + if ((cur_uid == 0) || correct_password(pw)) { + if (ENABLE_SU_SYSLOG) + syslog(LOG_NOTICE, "+ %s %s:%s", tty, old_user, opt_username); } else { - log_su_failure (pw->pw_uid, old_user, tty ); - bb_error_msg_and_die ( "incorrect password" ); + if (ENABLE_SU_SYSLOG) + syslog(LOG_NOTICE, "- %s %s:%s", tty, old_user, opt_username); + bb_error_msg_and_die("incorrect password"); } -#if defined( SYSLOG_SUCCESS ) || defined( SYSLOG_FAILURE ) - closelog(); -#endif + if (ENABLE_FEATURE_CLEAN_UP && ENABLE_SU_SYSLOG) { + closelog(); + free(old_user); + } - if ( !opt_shell && (flags & SU_OPT_p)) - opt_shell = getenv ( "SHELL" ); + if (!opt_shell && (flags & SU_OPT_mp)) opt_shell = getenv("SHELL"); - if ( opt_shell && cur_uid && 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 = 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);) - change_identity ( pw ); - setup_environment(opt_shell, flags & SU_OPT_l, !(flags & SU_OPT_p), pw); -#if ENABLE_SELINUX - set_current_security_context(NULL); -#endif + /* Returns only on error */ run_shell(opt_shell, flags & SU_OPT_l, opt_command, (const char**)opt_args); return EXIT_FAILURE; |