X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=loginutils%2Fsu.c;h=660ec6f515c172a321ac195ffe4d0b9b8321f540;hb=2aced7ea043aff64bd4e5f2814818fb4d0c803d4;hp=33e62e837875c3171a58a0eba2c91357c0b86d68;hpb=1fca558799350fb6caff97f55aa6d1237b08fccb;p=oweals%2Fbusybox.git diff --git a/loginutils/su.c b/loginutils/su.c index 33e62e837..660ec6f51 100644 --- a/loginutils/su.c +++ b/loginutils/su.c @@ -1,167 +1,94 @@ /* vi: set sw=4 ts=4: */ +/* + * Mini su implementation for busybox + * + * Licensed under the GPL v2, see the file LICENSE in this tarball. + */ #include "busybox.h" - -#include #include -#include -#include -#include #include -#include -#include -#include #include -#include -#include -#include -#include #include -#include "pwd.h" -#include "grp.h" - -#include "tinylogin.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, opt_args ); - return EXIT_FAILURE; }