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/* vi: set sw=4 ts=4: */
#include "busybox.h"
#include <fcntl.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 "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;
char *opt_shell = 0;
char *opt_command = 0;
char *opt_username = DEFAULT_USER;
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;
}
}
if (( optind < argc ) && ( argv [optind][0] == '-' ) && ( argv [optind][1] == 0 )) {
opt_loginshell = 1;
++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 );
/* 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 ( !opt_shell && opt_preserve )
opt_shell = getenv ( "SHELL" );
if ( opt_shell && getuid ( ) && 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 = xstrdup ( pw-> pw_shell );
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;
}
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