f4f6e5144b
function old new delta exec_login_shell - 12 +12 sulogin_main 247 240 -7 login_main 960 953 -7 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 0/2 up/down: 12/-14) Total: -2 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
94 lines
2.3 KiB
C
94 lines
2.3 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* Mini sulogin implementation for busybox
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*
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* Licensed under GPLv2 or later, see file LICENSE in this source tree.
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*/
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//config:config SULOGIN
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//config: bool "sulogin (17 kb)"
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//config: default y
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//config: select FEATURE_SYSLOG
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//config: help
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//config: sulogin is invoked when the system goes into single user
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//config: mode (this is done through an entry in inittab).
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//applet:IF_SULOGIN(APPLET_NOEXEC(sulogin, sulogin, BB_DIR_SBIN, BB_SUID_DROP, sulogin))
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//kbuild:lib-$(CONFIG_SULOGIN) += sulogin.o
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//usage:#define sulogin_trivial_usage
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//usage: "[-t N] [TTY]"
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//usage:#define sulogin_full_usage "\n\n"
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//usage: "Single user login\n"
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//usage: "\n -t N Timeout"
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#include "libbb.h"
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#include <syslog.h>
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int sulogin_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int sulogin_main(int argc UNUSED_PARAM, char **argv)
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{
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int timeout = 0;
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struct passwd *pwd;
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const char *shell;
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/* Note: sulogin is not a suid app. It is meant to be run by init
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* for single user / emergency mode. init starts it as root.
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* Normal users (potentially malicious ones) can only run it under
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* their UID, therefore no paranoia here is warranted:
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* $LD_LIBRARY_PATH in env, TTY = /dev/sda
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* are no more dangerous here than in e.g. cp applet.
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*/
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logmode = LOGMODE_BOTH;
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openlog(applet_name, 0, LOG_AUTH);
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getopt32(argv, "t:+", &timeout);
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argv += optind;
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if (argv[0]) {
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close(0);
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close(1);
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dup(xopen(argv[0], O_RDWR));
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close(2);
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dup(0);
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}
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pwd = getpwuid(0);
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if (!pwd) {
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bb_simple_error_msg_and_die("no password entry for root");
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}
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while (1) {
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int r;
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r = ask_and_check_password_extended(pwd, timeout,
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"Give root password for system maintenance\n"
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"(or type Control-D for normal startup):"
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);
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if (r < 0) {
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/* ^D, ^C, timeout, or read error */
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bb_simple_info_msg("normal startup");
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return 0;
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}
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if (r > 0) {
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break;
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}
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pause_after_failed_login();
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bb_simple_info_msg("Login incorrect");
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}
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bb_simple_info_msg("starting shell for system maintenance");
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IF_SELINUX(renew_current_security_context());
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shell = getenv("SUSHELL");
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if (!shell)
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shell = getenv("sushell");
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if (!shell)
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shell = pwd->pw_shell;
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/* Exec login shell with no additional parameters. Never returns. */
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exec_login_shell(shell);
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}
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