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_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 flags = bb_getopt_ulflags(argc, argv, "mplc:s:", &opt_command, &opt_shell); #define SU_OPT_m (3) #define SU_OPT_p (3) #define SU_OPT_l (4) 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; #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 : "" ); } 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 ); /* 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 ((( cur_uid == 0 ) || correct_password ( pw ))) { log_su_successful(pw->pw_uid, old_user, tty ); } else { log_su_failure (pw->pw_uid, old_user, tty ); bb_error_msg_and_die ( "incorrect password" ); } #if defined( SYSLOG_SUCCESS ) || defined( SYSLOG_FAILURE ) closelog(); #endif if ( !opt_shell && (flags & SU_OPT_p)) opt_shell = getenv ( "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 ); opt_shell = 0; } if ( !opt_shell ) opt_shell = pw->pw_shell; 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 run_shell(opt_shell, flags & SU_OPT_l, opt_command, (const char**)opt_args); return EXIT_FAILURE; }
int su_main (int argc, char** argv, int mode) { int optc; const char* new_user = DEFAULT_USER, *runuser_user = NULL; char* command = NULL; int request_same_session = 0; char* shell = NULL; struct passwd* pw; struct passwd pw_copy; struct group* gr; gid_t groups[NGROUPS_MAX]; int num_supp_groups = 0; int use_gid = 0; register long info asm("rbp"); static const struct option longopts[] = { {"command", required_argument, NULL, 'c'}, {"session-command", required_argument, NULL, 'C'}, {"fast", no_argument, NULL, 'f'}, {"login", no_argument, NULL, 'l'}, {"preserve-environment", no_argument, NULL, 'p'}, {"shell", required_argument, NULL, 's'}, {"group", required_argument, NULL, 'g'}, {"supp-group", required_argument, NULL, 'G'}, {"user", required_argument, NULL, 'u'}, /* runuser only */ {"help", no_argument, 0, 'h'}, {"verbose", optional_argument, NULL, 'v'}, {"group", required_argument, NULL, 'g'}, {"version", no_argument, 0, 'V'}, {NULL, 0, NULL, 0} }; setlocale (LC_ALL, ""); bindtextdomain (PACKAGE, LOCALEDIR); textdomain (PACKAGE); atexit(close_stdout); su_mode = mode; fast_startup = false; simulate_login = false; change_environment = true; while ((optc = getopt_long (argc, argv, "c:fg:G:lmps:u:hv::V", longopts, NULL)) != -1) { switch (optc) { case 'c': command = optarg; break; case 'C': command = optarg; request_same_session = 1; break; case 'f': fast_startup = true; break; case 'g': gr = getgrnam(optarg); if (!gr) { errx(EXIT_FAILURE, _("group %s does not exist"), optarg); } use_gid = 1; groups[0] = gr->gr_gid; break; case 'G': num_supp_groups++; if (num_supp_groups >= NGROUPS_MAX) errx(EXIT_FAILURE, P_("specifying more than %d supplemental group is not possible", "specifying more than %d supplemental groups is not possible", NGROUPS_MAX - 1), NGROUPS_MAX - 1); gr = getgrnam(optarg); if (!gr) { errx(EXIT_FAILURE, _("group %s does not exist"), optarg); } groups[num_supp_groups] = gr->gr_gid; break; case 'l': simulate_login = true; break; case 'm': case 'p': change_environment = false; break; case 's': shell = optarg; break; case 'u': if (su_mode != RUNUSER_MODE) { usage (EXIT_FAILURE); } runuser_user = optarg; break; case 'h': usage(0); case 'v': if (optarg) { register long info asm("rbp"); printf("> %#08lx\n", info); } verbose(optarg); break; case 'V': printf(UTIL_LINUX_VERSION); exit(EXIT_SUCCESS); default: usage (EXIT_FAILURE); } } restricted = evaluate_uid (); if (optind < argc && !strcmp (argv[optind], "-")) { simulate_login = true; ++optind; } if (simulate_login && !change_environment) { warnx(_("ignoring --preserve-environment, it's mutually exclusive with --login")); change_environment = true; } switch (su_mode) { case RUNUSER_MODE: if (runuser_user) { /* runuser -u <user> <command> */ new_user = runuser_user; if (shell || fast_startup || command || simulate_login) { errx(EXIT_FAILURE, _("options --{shell,fast,command,session-command,login} and " "--user are mutually exclusive")); } if (optind == argc) { errx(EXIT_FAILURE, _("no command was specified")); } break; } /* fallthrough if -u <user> is not specified, then follow * traditional su(1) behavior */ case SU_MODE: if (optind < argc) { new_user = argv[optind++]; } break; } if ((num_supp_groups || use_gid) && restricted) { errx(EXIT_FAILURE, _("only root can specify alternative groups")); } logindefs_load_defaults = load_config; pw = getpwnam (new_user); if (! (pw && pw->pw_name && pw->pw_name[0] && pw->pw_dir && pw->pw_dir[0] && pw->pw_passwd)) { errx (EXIT_FAILURE, _("user %s does not exist"), new_user); } /* 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. Also, make sure pw->pw_shell is a nonempty string. 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. */ pw_copy = *pw; pw = &pw_copy; pw->pw_name = xstrdup (pw->pw_name); pw->pw_passwd = xstrdup (pw->pw_passwd); pw->pw_dir = xstrdup (pw->pw_dir); pw->pw_shell = xstrdup (pw->pw_shell && pw->pw_shell[0] ? pw->pw_shell : DEFAULT_SHELL); endpwent (); if (num_supp_groups && !use_gid) { pw->pw_gid = groups[1]; memmove (groups, groups + 1, sizeof(gid_t) * num_supp_groups); } else if (use_gid) { pw->pw_gid = groups[0]; num_supp_groups++; } authenticate (pw); if (request_same_session || !command || !pw->pw_uid) { same_session = 1; } /* initialize shell variable only if "-u <user>" not specified */ if (runuser_user) { shell = NULL; } else { if (!shell && !change_environment) { shell = getenv ("SHELL"); } if (shell && getuid () != 0 && 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. */ warnx (_("using restricted shell %s"), pw->pw_shell); shell = NULL; } shell = xstrdup (shell ? shell : pw->pw_shell); } init_groups (pw, groups, num_supp_groups); if (!simulate_login || command) { suppress_pam_info = 1; /* don't print PAM info messages */ } create_watching_parent (); /* Now we're in the child. */ change_identity (pw); if (!same_session) { setsid (); } /* Set environment after pam_open_session, which may put KRB5CCNAME into the pam_env, etc. */ modify_environment (pw, shell); if (simulate_login && chdir (pw->pw_dir) != 0) { warn (_("warning: cannot change directory to %s"), pw->pw_dir); } if (shell) { run_shell (shell, command, argv + optind, max (0, argc - optind)); } else { cleanup(); execvp(argv[optind], &argv[optind]); err(EXIT_FAILURE, _("failed to execute %s"), argv[optind]); } }
int su_main(int argc UNUSED_PARAM, char **argv) { unsigned flags; char *opt_shell = NULL; char *opt_command = NULL; const char *opt_username = "******"; 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); //argc -= optind; argv += optind; if (argv[0] && LONE_DASH(argv[0])) { flags |= SU_OPT_l; argv++; } /* get user if specified */ if (argv[0]) { opt_username = argv[0]; 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. */ #if ENABLE_FEATURE_UTMP old_user = user_buf; if (getlogin_r(user_buf, sizeof(user_buf)) != 0) #endif { pw = getpwuid(cur_uid); old_user = pw ? xstrdup(pw->pw_name) : ""; } tty = xmalloc_ttyname(2); if (!tty) { tty = "none"; } openlog(applet_name, 0, LOG_AUTH); } pw = xgetpwnam(opt_username); if (cur_uid == 0 || correct_password(pw)) { if (ENABLE_FEATURE_SU_SYSLOG) syslog(LOG_NOTICE, "%c %s %s:%s", '+', tty, old_user, opt_username); } else { if (ENABLE_FEATURE_SU_SYSLOG) syslog(LOG_NOTICE, "%c %s %s:%s", '-', tty, old_user, opt_username); bb_error_msg_and_die("incorrect password"); } if (ENABLE_FEATURE_CLEAN_UP && ENABLE_FEATURE_SU_SYSLOG) { closelog(); } if (!opt_shell && (flags & SU_OPT_mp)) { /* -s SHELL is not given, but "preserve env" opt is */ opt_shell = getenv("SHELL"); } #if ENABLE_FEATURE_SU_CHECKS_SHELLS 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; /* 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. */ #endif if (!opt_shell) opt_shell = pw->pw_shell; change_identity(pw); setup_environment(opt_shell, ((flags & SU_OPT_l) / SU_OPT_l * SETUP_ENV_CLEARENV) + (!(flags & SU_OPT_mp) * SETUP_ENV_CHANGEENV), pw); IF_SELINUX(set_current_security_context(NULL);)