/**
* Mane method
*
* @param argc The number of command line arguments
* @param argv The command line arguments
* @return Return code
*/
int main(int argc, char** argv)
{
char* tty_device = ttyname(STDIN_FILENO);
do_login(argc, argv);
/* Ignore signals */
signal(SIGQUIT, SIG_IGN);
signal(SIGINT, SIG_IGN);
/* Wait for the login shell and all grandchildren to exit */
while ((wait(NULL) == -1) && (errno == EINTR))
;
/* Regain access to the terminal */
if (tty_device)
{
int fd = open(tty_device, O_RDWR | O_NONBLOCK);
if (fd != 0) dup2(fd, 0);
if (fd != 1) dup2(fd, 1);
if (fd != 2) dup2(fd, 2);
}
/* Reset terminal ownership and mode */
chown_tty(0, tty_group, 0);
/* Close login session */
close_login_session();
/* Run logout hook */
exec_hook(HOOK_LOGOUT, argc, argv);
return 0;
}
/**
* Secure the TTY from spying
*
* @param group The group, -1 for unchanged
*/
void secure_tty(gid_t group)
{
struct termios tty;
struct termios saved_tty;
char* tty_device;
int fd, i;
/* Set ownership of this TTY to root:root */
chown_tty(0, group, 1);
/* Get TTY name for last part of this functions */
tty_device = ttyname(STDIN_FILENO);
/* Kill other processes on this TTY */
tcgetattr(STDIN_FILENO, &tty);
saved_tty = tty;
tty.c_cflag &= (tcflag_t)~HUPCL;
tcsetattr(0, TCSANOW, &tty);
close(STDIN_FILENO);
close(STDOUT_FILENO);
close(STDERR_FILENO);
signal(SIGHUP, SIG_IGN);
vhangup();
signal(SIGHUP, SIG_DFL);
/* Restore terminal and TTY modes */
fd = open(tty_device, O_RDWR | O_NONBLOCK);
if (fd == -1)
fail("open");
fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK);
for (i = 0; i < fd; i++)
close(i);
for (i = 0; i < 3; i++)
if (i != fd)
dup2(fd, i);
if (fd > 2)
close(fd);
tcgetattr(STDIN_FILENO, &saved_tty);
}
/*
* login - create a new login session for a user
*
* login is typically called by getty as the second step of a
* new user session. getty is responsible for setting the line
* characteristics to a reasonable set of values and getting
* the name of the user to be logged in. login may also be
* called to create a new user session on a pty for a variety
* of reasons, such as X servers or network logins.
*
* the flags which login supports are
*
* -p - preserve the environment
* -r - perform autologin protocol for rlogin
* -f - do not perform authentication, user is preauthenticated
* -h - the name of the remote host
*/
int main (int argc, char **argv)
{
const char *tmptty;
char tty[BUFSIZ];
#ifdef RLOGIN
char term[128] = "";
#endif /* RLOGIN */
#if defined(HAVE_STRFTIME) && !defined(USE_PAM)
char ptime[80];
#endif
unsigned int delay;
unsigned int retries;
bool failed;
bool subroot = false;
#ifndef USE_PAM
bool is_console;
#endif
int err;
const char *cp;
char *tmp;
char fromhost[512];
struct passwd *pwd = NULL;
char **envp = environ;
const char *failent_user;
/*@null@*/struct utmp *utent;
#ifdef USE_PAM
int retcode;
pid_t child;
char *pam_user = NULL;
#else
struct spwd *spwd = NULL;
#endif
/*
* Some quick initialization.
*/
sanitize_env ();
(void) setlocale (LC_ALL, "");
(void) bindtextdomain (PACKAGE, LOCALEDIR);
(void) textdomain (PACKAGE);
initenv ();
amroot = (getuid () == 0);
Prog = Basename (argv[0]);
if (geteuid() != 0) {
fprintf (stderr, _("%s: Cannot possibly work without effective root\n"), Prog);
exit (1);
}
process_flags (argc, argv);
if ((isatty (0) == 0) || (isatty (1) == 0) || (isatty (2) == 0)) {
exit (1); /* must be a terminal */
}
utent = get_current_utmp ();
/*
* Be picky if run by normal users (possible if installed setuid
* root), but not if run by root. This way it still allows logins
* even if your getty is broken, or if something corrupts utmp,
* but users must "exec login" which will use the existing utmp
* entry (will not overwrite remote hostname). --marekm
*/
if (!amroot && (NULL == utent)) {
(void) puts (_("No utmp entry. You must exec \"login\" from the lowest level \"sh\""));
exit (1);
}
/* NOTE: utent might be NULL afterwards */
tmptty = ttyname (0);
if (NULL == tmptty) {
tmptty = "UNKNOWN";
}
STRFCPY (tty, tmptty);
#ifndef USE_PAM
is_console = console (tty);
#endif
if (rflg || hflg) {
/*
* Add remote hostname to the environment. I think
* (not sure) I saw it once on Irix. --marekm
*/
addenv ("REMOTEHOST", hostname);
}
if (fflg) {
preauth_flag = true;
}
if (hflg) {
reason = PW_RLOGIN;
}
#ifdef RLOGIN
if (rflg) {
assert (NULL == username);
username = xmalloc (USER_NAME_MAX_LENGTH + 1);
username[USER_NAME_MAX_LENGTH] = '\0';
if (do_rlogin (hostname, username, USER_NAME_MAX_LENGTH, term, sizeof term)) {
preauth_flag = true;
} else {
free (username);
username = NULL;
}
}
#endif /* RLOGIN */
OPENLOG ("login");
setup_tty ();
#ifndef USE_PAM
(void) umask (getdef_num ("UMASK", GETDEF_DEFAULT_UMASK));
{
/*
* Use the ULIMIT in the login.defs file, and if
* there isn't one, use the default value. The
* user may have one for themselves, but otherwise,
* just take what you get.
*/
long limit = getdef_long ("ULIMIT", -1L);
if (limit != -1) {
set_filesize_limit (limit);
}
}
#endif
/*
* The entire environment will be preserved if the -p flag
* is used.
*/
if (pflg) {
while (NULL != *envp) { /* add inherited environment, */
addenv (*envp, NULL); /* some variables change later */
envp++;
}
}
#ifdef RLOGIN
if (term[0] != '\0') {
addenv ("TERM", term);
} else
#endif /* RLOGIN */
{
/* preserve TERM from getty */
if (!pflg) {
tmp = getenv ("TERM");
if (NULL != tmp) {
addenv ("TERM", tmp);
}
}
}
init_env ();
if (optind < argc) { /* now set command line variables */
set_env (argc - optind, &argv[optind]);
}
if (rflg || hflg) {
cp = hostname;
#ifdef HAVE_STRUCT_UTMP_UT_HOST
} else if ((NULL != utent) && ('\0' != utent->ut_host[0])) {
cp = utent->ut_host;
#endif /* HAVE_STRUCT_UTMP_UT_HOST */
} else {
cp = "";
}
if ('\0' != *cp) {
snprintf (fromhost, sizeof fromhost,
" on '%.100s' from '%.200s'", tty, cp);
} else {
snprintf (fromhost, sizeof fromhost,
" on '%.100s'", tty);
}
top:
/* only allow ALARM sec. for login */
(void) signal (SIGALRM, alarm_handler);
timeout = getdef_unum ("LOGIN_TIMEOUT", ALARM);
if (timeout > 0) {
(void) alarm (timeout);
}
environ = newenvp; /* make new environment active */
delay = getdef_unum ("FAIL_DELAY", 1);
retries = getdef_unum ("LOGIN_RETRIES", RETRIES);
#ifdef USE_PAM
retcode = pam_start ("login", username, &conv, &pamh);
if (retcode != PAM_SUCCESS) {
fprintf (stderr,
_("login: PAM Failure, aborting: %s\n"),
pam_strerror (pamh, retcode));
SYSLOG ((LOG_ERR, "Couldn't initialize PAM: %s",
pam_strerror (pamh, retcode)));
exit (99);
}
/*
* hostname & tty are either set to NULL or their correct values,
* depending on how much we know. We also set PAM's fail delay to
* ours.
*
* PAM_RHOST and PAM_TTY are used for authentication, only use
* information coming from login or from the caller (e.g. no utmp)
*/
retcode = pam_set_item (pamh, PAM_RHOST, hostname);
PAM_FAIL_CHECK;
retcode = pam_set_item (pamh, PAM_TTY, tty);
PAM_FAIL_CHECK;
#ifdef HAS_PAM_FAIL_DELAY
retcode = pam_fail_delay (pamh, 1000000 * delay);
PAM_FAIL_CHECK;
#endif
/* if fflg, then the user has already been authenticated */
if (!fflg) {
unsigned int failcount = 0;
char hostn[256];
char loginprompt[256]; /* That's one hell of a prompt :) */
/* Make the login prompt look like we want it */
if (gethostname (hostn, sizeof (hostn)) == 0) {
snprintf (loginprompt,
sizeof (loginprompt),
_("%s login: "******"login: "******"TOO MANY LOGIN TRIES (%u)%s FOR '%s'",
failcount, fromhost, failent_user));
fprintf(stderr,
_("Maximum number of tries exceeded (%u)\n"),
failcount);
PAM_END;
exit(0);
} else if (retcode == PAM_ABORT) {
/* Serious problems, quit now */
(void) fputs (_("login: abort requested by PAM\n"), stderr);
SYSLOG ((LOG_ERR,"PAM_ABORT returned from pam_authenticate()"));
PAM_END;
exit(99);
} else if (retcode != PAM_SUCCESS) {
SYSLOG ((LOG_NOTICE,"FAILED LOGIN (%u)%s FOR '%s', %s",
failcount, fromhost, failent_user,
pam_strerror (pamh, retcode)));
failed = true;
}
if (!failed) {
break;
}
#ifdef WITH_AUDIT
audit_fd = audit_open ();
audit_log_acct_message (audit_fd,
AUDIT_USER_LOGIN,
NULL, /* Prog. name */
"login",
failent_user,
AUDIT_NO_ID,
hostname,
NULL, /* addr */
tty,
0); /* result */
close (audit_fd);
#endif /* WITH_AUDIT */
(void) puts ("");
(void) puts (_("Login incorrect"));
if (failcount >= retries) {
SYSLOG ((LOG_NOTICE,
"TOO MANY LOGIN TRIES (%u)%s FOR '%s'",
failcount, fromhost, failent_user));
fprintf(stderr,
_("Maximum number of tries exceeded (%u)\n"),
failcount);
PAM_END;
exit(0);
}
/*
* Let's give it another go around.
* Even if a username was given on the command
* line, prompt again for the username.
*/
retcode = pam_set_item (pamh, PAM_USER, NULL);
PAM_FAIL_CHECK;
}
/* We don't get here unless they were authenticated above */
(void) alarm (0);
}
/* Check the account validity */
retcode = pam_acct_mgmt (pamh, 0);
if (retcode == PAM_NEW_AUTHTOK_REQD) {
retcode = pam_chauthtok (pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
}
PAM_FAIL_CHECK;
/* Open the PAM session */
get_pam_user (&pam_user);
retcode = pam_open_session (pamh, hushed (pam_user) ? PAM_SILENT : 0);
PAM_FAIL_CHECK;
/* Grab the user information out of the password file for future usage
* First get the username that we are actually using, though.
*
* From now on, we will discard changes of the user (PAM_USER) by
* PAM APIs.
*/
get_pam_user (&pam_user);
if (NULL != username) {
free (username);
}
username = pam_user;
failent_user = get_failent_user (username);
pwd = xgetpwnam (username);
if (NULL == pwd) {
SYSLOG ((LOG_ERR, "cannot find user %s", failent_user));
exit (1);
}
/* This set up the process credential (group) and initialize the
* supplementary group access list.
* This has to be done before pam_setcred
*/
if (setup_groups (pwd) != 0) {
exit (1);
}
retcode = pam_setcred (pamh, PAM_ESTABLISH_CRED);
PAM_FAIL_CHECK;
/* NOTE: If pam_setcred changes PAM_USER, this will not be taken
* into account.
*/
#else /* ! USE_PAM */
while (true) { /* repeatedly get login/password pairs */
/* user_passwd is always a pointer to this constant string
* or a passwd or shadow password that will be memzero by
* pw_free / spw_free.
* Do not free() user_passwd. */
const char *user_passwd = "!";
/* Do some cleanup to avoid keeping entries we do not need
* anymore. */
if (NULL != pwd) {
pw_free (pwd);
pwd = NULL;
}
if (NULL != spwd) {
spw_free (spwd);
spwd = NULL;
}
failed = false; /* haven't failed authentication yet */
if (NULL == username) { /* need to get a login id */
if (subroot) {
closelog ();
exit (1);
}
preauth_flag = false;
username = xmalloc (USER_NAME_MAX_LENGTH + 1);
username[USER_NAME_MAX_LENGTH] = '\0';
login_prompt (_("\n%s login: "******"!",
* the account is locked and the user cannot
* login, even if they have been
* "pre-authenticated."
*/
if ( ('!' == user_passwd[0])
|| ('*' == user_passwd[0])) {
failed = true;
}
}
if (strcmp (user_passwd, SHADOW_PASSWD_STRING) == 0) {
spwd = xgetspnam (username);
if (NULL != spwd) {
user_passwd = spwd->sp_pwdp;
} else {
/* The user exists in passwd, but not in
* shadow. SHADOW_PASSWD_STRING indicates
* that the password shall be in shadow.
*/
SYSLOG ((LOG_WARN,
"no shadow password for '%s'%s",
username, fromhost));
}
}
/*
* The -r and -f flags provide a name which has already
* been authenticated by some server.
*/
if (preauth_flag) {
goto auth_ok;
}
if (pw_auth (user_passwd, username, reason, (char *) 0) == 0) {
goto auth_ok;
}
SYSLOG ((LOG_WARN, "invalid password for '%s' %s",
failent_user, fromhost));
failed = true;
auth_ok:
/*
* This is the point where all authenticated users wind up.
* If you reach this far, your password has been
* authenticated and so on.
*/
if ( !failed
&& (NULL != pwd)
&& (0 == pwd->pw_uid)
&& !is_console) {
SYSLOG ((LOG_CRIT, "ILLEGAL ROOT LOGIN %s", fromhost));
failed = true;
}
if ( !failed
&& !login_access (username, ('\0' != *hostname) ? hostname : tty)) {
SYSLOG ((LOG_WARN, "LOGIN '%s' REFUSED %s",
username, fromhost));
failed = true;
}
if ( (NULL != pwd)
&& getdef_bool ("FAILLOG_ENAB")
&& !failcheck (pwd->pw_uid, &faillog, failed)) {
SYSLOG ((LOG_CRIT,
"exceeded failure limit for '%s' %s",
username, fromhost));
failed = true;
}
if (!failed) {
break;
}
/* don't log non-existent users */
if ((NULL != pwd) && getdef_bool ("FAILLOG_ENAB")) {
failure (pwd->pw_uid, tty, &faillog);
}
if (getdef_str ("FTMP_FILE") != NULL) {
#ifdef USE_UTMPX
struct utmpx *failent =
prepare_utmpx (failent_user,
tty,
/* FIXME: or fromhost? */hostname,
utent);
#else /* !USE_UTMPX */
struct utmp *failent =
prepare_utmp (failent_user,
tty,
hostname,
utent);
#endif /* !USE_UTMPX */
failtmp (failent_user, failent);
free (failent);
}
retries--;
if (retries <= 0) {
SYSLOG ((LOG_CRIT, "REPEATED login failures%s",
fromhost));
}
/*
* If this was a passwordless account and we get here, login
* was denied (securetty, faillog, etc.). There was no
* password prompt, so do it now (will always fail - the bad
* guys won't see that the passwordless account exists at
* all). --marekm
*/
if (user_passwd[0] == '\0') {
pw_auth ("!", username, reason, (char *) 0);
}
/*
* Authentication of this user failed.
* The username must be confirmed in the next try.
*/
free (username);
username = NULL;
/*
* Wait a while (a la SVR4 /usr/bin/login) before attempting
* to login the user again. If the earlier alarm occurs
* before the sleep() below completes, login will exit.
*/
if (delay > 0) {
(void) sleep (delay);
}
(void) puts (_("Login incorrect"));
/* allow only one attempt with -r or -f */
if (rflg || fflg || (retries <= 0)) {
closelog ();
exit (1);
}
} /* while (true) */
#endif /* ! USE_PAM */
assert (NULL != username);
assert (NULL != pwd);
(void) alarm (0); /* turn off alarm clock */
#ifndef USE_PAM /* PAM does this */
/*
* porttime checks moved here, after the user has been
* authenticated. now prints a message, as suggested
* by Ivan Nejgebauer <*****@*****.**>. --marekm
*/
if ( getdef_bool ("PORTTIME_CHECKS_ENAB")
&& !isttytime (username, tty, time ((time_t *) 0))) {
SYSLOG ((LOG_WARN, "invalid login time for '%s'%s",
username, fromhost));
closelog ();
bad_time_notify ();
exit (1);
}
check_nologin (pwd->pw_uid == 0);
#endif
if (getenv ("IFS")) { /* don't export user IFS ... */
addenv ("IFS= \t\n", NULL); /* ... instead, set a safe IFS */
}
if (pwd->pw_shell[0] == '*') { /* subsystem root */
pwd->pw_shell++; /* skip the '*' */
subsystem (pwd); /* figure out what to execute */
subroot = true; /* say I was here again */
endpwent (); /* close all of the file which were */
endgrent (); /* open in the original rooted file */
endspent (); /* system. they will be re-opened */
#ifdef SHADOWGRP
endsgent (); /* in the new rooted file system */
#endif
goto top; /* go do all this all over again */
}
#ifdef WITH_AUDIT
audit_fd = audit_open ();
audit_log_acct_message (audit_fd,
AUDIT_USER_LOGIN,
NULL, /* Prog. name */
"login",
username,
AUDIT_NO_ID,
hostname,
NULL, /* addr */
tty,
1); /* result */
close (audit_fd);
#endif /* WITH_AUDIT */
#ifndef USE_PAM /* pam_lastlog handles this */
if (getdef_bool ("LASTLOG_ENAB")) { /* give last login and log this one */
dolastlog (&ll, pwd, tty, hostname);
}
#endif
#ifndef USE_PAM /* PAM handles this as well */
/*
* Have to do this while we still have root privileges, otherwise we
* don't have access to /etc/shadow.
*/
if (NULL != spwd) { /* check for age of password */
if (expire (pwd, spwd)) {
/* The user updated her password, get the new
* entries.
* Use the x variants because we need to keep the
* entry for a long time, and there might be other
* getxxyy in between.
*/
pw_free (pwd);
pwd = xgetpwnam (username);
if (NULL == pwd) {
SYSLOG ((LOG_ERR,
"cannot find user %s after update of expired password",
username));
exit (1);
}
spw_free (spwd);
spwd = xgetspnam (username);
}
}
setup_limits (pwd); /* nice, ulimit etc. */
#endif /* ! USE_PAM */
chown_tty (pwd);
#ifdef USE_PAM
/*
* We must fork before setuid() because we need to call
* pam_close_session() as root.
*/
(void) signal (SIGINT, SIG_IGN);
child = fork ();
if (child < 0) {
/* error in fork() */
fprintf (stderr, _("%s: failure forking: %s"),
Prog, strerror (errno));
PAM_END;
exit (0);
} else if (child != 0) {
/*
* parent - wait for child to finish, then cleanup
* session
*/
wait (NULL);
PAM_END;
exit (0);
}
/* child */
#endif
/* If we were init, we need to start a new session */
if (getppid() == 1) {
setsid();
if (ioctl(0, TIOCSCTTY, 1) != 0) {
fprintf (stderr, _("TIOCSCTTY failed on %s"), tty);
}
}
/*
* The utmp entry needs to be updated to indicate the new status
* of the session, the new PID and SID.
*/
update_utmp (username, tty, hostname, utent);
/* The pwd and spwd entries for the user have been copied.
*
* Close all the files so that unauthorized access won't occur.
*/
endpwent (); /* stop access to password file */
endgrent (); /* stop access to group file */
endspent (); /* stop access to shadow passwd file */
#ifdef SHADOWGRP
endsgent (); /* stop access to shadow group file */
#endif
/* Drop root privileges */
#ifndef USE_PAM
if (setup_uid_gid (pwd, is_console))
#else
/* The group privileges were already dropped.
* See setup_groups() above.
*/
if (change_uid (pwd))
#endif
{
exit (1);
}
setup_env (pwd); /* set env vars, cd to the home dir */
#ifdef USE_PAM
{
const char *const *env;
env = (const char *const *) pam_getenvlist (pamh);
while ((NULL != env) && (NULL != *env)) {
addenv (*env, NULL);
env++;
}
}
#endif
(void) setlocale (LC_ALL, "");
(void) bindtextdomain (PACKAGE, LOCALEDIR);
(void) textdomain (PACKAGE);
if (!hushed (username)) {
addenv ("HUSHLOGIN=FALSE", NULL);
/*
* pam_unix, pam_mail and pam_lastlog should take care of
* this
*/
#ifndef USE_PAM
motd (); /* print the message of the day */
if ( getdef_bool ("FAILLOG_ENAB")
&& (0 != faillog.fail_cnt)) {
failprint (&faillog);
/* Reset the lockout times if logged in */
if ( (0 != faillog.fail_max)
&& (faillog.fail_cnt >= faillog.fail_max)) {
(void) puts (_("Warning: login re-enabled after temporary lockout."));
SYSLOG ((LOG_WARN,
"login '%s' re-enabled after temporary lockout (%d failures)",
username, (int) faillog.fail_cnt));
}
}
if ( getdef_bool ("LASTLOG_ENAB")
&& (ll.ll_time != 0)) {
time_t ll_time = ll.ll_time;
#ifdef HAVE_STRFTIME
(void) strftime (ptime, sizeof (ptime),
"%a %b %e %H:%M:%S %z %Y",
localtime (&ll_time));
printf (_("Last login: %s on %s"),
ptime, ll.ll_line);
#else
printf (_("Last login: %.19s on %s"),
ctime (&ll_time), ll.ll_line);
#endif
#ifdef HAVE_LL_HOST /* __linux__ || SUN4 */
if ('\0' != ll.ll_host[0]) {
printf (_(" from %.*s"),
(int) sizeof ll.ll_host, ll.ll_host);
}
#endif
printf (".\n");
}
agecheck (spwd);
mailcheck (); /* report on the status of mail */
#endif /* !USE_PAM */
} else {
addenv ("HUSHLOGIN=TRUE", NULL);
}
ttytype (tty);
(void) signal (SIGQUIT, SIG_DFL); /* default quit signal */
(void) signal (SIGTERM, SIG_DFL); /* default terminate signal */
(void) signal (SIGALRM, SIG_DFL); /* default alarm signal */
(void) signal (SIGHUP, SIG_DFL); /* added this. --marekm */
(void) signal (SIGINT, SIG_DFL); /* default interrupt signal */
if (0 == pwd->pw_uid) {
SYSLOG ((LOG_NOTICE, "ROOT LOGIN %s", fromhost));
} else if (getdef_bool ("LOG_OK_LOGINS")) {
SYSLOG ((LOG_INFO, "'%s' logged in %s", username, fromhost));
}
closelog ();
tmp = getdef_str ("FAKE_SHELL");
if (NULL != tmp) {
err = shell (tmp, pwd->pw_shell, newenvp); /* fake shell */
} else {
/* exec the shell finally */
err = shell (pwd->pw_shell, (char *) 0, newenvp);
}
return ((err == ENOENT) ? E_CMD_NOTFOUND : E_CMD_NOEXEC);
}
int main(int argc, char **argv)
{
int c;
int cnt;
char *childArgv[10];
char *buff;
int childArgc = 0;
int retcode;
char *pwdbuf = NULL;
struct passwd *pwd = NULL, _pwd;
struct login_context cxt = {
.tty_mode = TTY_MODE, /* tty chmod() */
.pid = getpid(), /* PID */
.conv = { misc_conv, NULL } /* PAM conversation function */
};
timeout = getlogindefs_num("LOGIN_TIMEOUT", LOGIN_TIMEOUT);
signal(SIGALRM, timedout);
siginterrupt(SIGALRM, 1); /* we have to interrupt syscalls like ioclt() */
alarm((unsigned int)timeout);
signal(SIGQUIT, SIG_IGN);
signal(SIGINT, SIG_IGN);
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
setpriority(PRIO_PROCESS, 0, 0);
initproctitle(argc, argv);
/*
* -p is used by getty to tell login not to destroy the environment
* -f is used to skip a second login authentication
* -h is used by other servers to pass the name of the remote
* host to login so that it may be placed in utmp and wtmp
*/
while ((c = getopt(argc, argv, "fHh:pV")) != -1)
switch (c) {
case 'f':
cxt.noauth = 1;
break;
case 'H':
cxt.nohost = 1;
break;
case 'h':
if (getuid()) {
fprintf(stderr,
_("login: -h for super-user only.\n"));
exit(EXIT_FAILURE);
}
init_remote_info(&cxt, optarg);
break;
case 'p':
cxt.keep_env = 1;
break;
case 'V':
printf(UTIL_LINUX_VERSION);
return EXIT_SUCCESS;
case '?':
default:
fprintf(stderr, _("usage: login [ -p ] [ -h host ] [ -H ] [ -f username | username ]\n"));
exit(EXIT_FAILURE);
}
argc -= optind;
argv += optind;
if (*argv) {
char *p = *argv;
cxt.username = xstrdup(p);
/* wipe name - some people mistype their password here */
/* (of course we are too late, but perhaps this helps a little ..) */
while (*p)
*p++ = ' ';
}
for (cnt = get_fd_tabsize() - 1; cnt > 2; cnt--)
close(cnt);
setpgrp(); /* set pgid to pid this means that setsid() will fail */
openlog("login", LOG_ODELAY, LOG_AUTHPRIV);
init_tty(&cxt);
init_loginpam(&cxt);
/* login -f, then the user has already been authenticated */
cxt.noauth = cxt.noauth && getuid() == 0 ? 1 : 0;
if (!cxt.noauth)
loginpam_auth(&cxt);
/*
* Authentication may be skipped (for example, during krlogin, rlogin,
* etc...), but it doesn't mean that we can skip other account checks.
* The account could be disabled or password expired (althought
* kerberos ticket is valid). -- [email protected] (22-Feb-2006)
*/
loginpam_acct(&cxt);
if (!(cxt.pwd = get_passwd_entry(cxt.username, &pwdbuf, &_pwd))) {
warnx(_("\nSession setup problem, abort."));
syslog(LOG_ERR, _("Invalid user name \"%s\" in %s:%d. Abort."),
cxt.username, __FUNCTION__, __LINE__);
pam_end(cxt.pamh, PAM_SYSTEM_ERR);
sleepexit(EXIT_FAILURE);
}
pwd = cxt.pwd;
cxt.username = pwd->pw_name;
/*
* Initialize the supplementary group list. This should be done before
* pam_setcred because the PAM modules might add groups during
* pam_setcred.
*
* For root we don't call initgroups, instead we call setgroups with
* group 0. This avoids the need to step through the whole group file,
* which can cause problems if NIS, NIS+, LDAP or something similar
* is used and the machine has network problems.
*/
retcode = pwd->pw_uid ? initgroups(cxt.username, pwd->pw_gid) : /* user */
setgroups(0, NULL); /* root */
if (retcode < 0) {
syslog(LOG_ERR, _("groups initialization failed: %m"));
warnx(_("\nSession setup problem, abort."));
pam_end(cxt.pamh, PAM_SYSTEM_ERR);
sleepexit(EXIT_FAILURE);
}
/*
* Open PAM session (after successful authentication and account check)
*/
loginpam_session(&cxt);
/* committed to login -- turn off timeout */
alarm((unsigned int)0);
endpwent();
cxt.quiet = get_hushlogin_status(pwd);
log_utmp(&cxt);
log_audit(&cxt, 1);
log_lastlog(&cxt);
chown_tty(&cxt);
if (setgid(pwd->pw_gid) < 0 && pwd->pw_gid) {
syslog(LOG_ALERT, _("setgid() failed"));
exit(EXIT_FAILURE);
}
if (pwd->pw_shell == NULL || *pwd->pw_shell == '\0')
pwd->pw_shell = _PATH_BSHELL;
init_environ(&cxt); /* init $HOME, $TERM ... */
setproctitle("login", cxt.username);
log_syslog(&cxt);
if (!cxt.quiet) {
motd();
#ifdef LOGIN_STAT_MAIL
/*
* This turns out to be a bad idea: when the mail spool
* is NFS mounted, and the NFS connection hangs, the
* login hangs, even root cannot login.
* Checking for mail should be done from the shell.
*/
{
struct stat st;
char *mail;
mail = getenv("MAIL");
if (mail && stat(mail, &st) == 0 && st.st_size != 0) {
if (st.st_mtime > st.st_atime)
printf(_("You have new mail.\n"));
else
printf(_("You have mail.\n"));
}
}
#endif
}
/*
* Detach the controlling terminal, fork() and create, new session
* and reinilizalize syslog stuff.
*/
fork_session(&cxt);
/* discard permissions last so can't get killed and drop core */
if (setuid(pwd->pw_uid) < 0 && pwd->pw_uid) {
syslog(LOG_ALERT, _("setuid() failed"));
exit(EXIT_FAILURE);
}
/* wait until here to change directory! */
if (chdir(pwd->pw_dir) < 0) {
warn(_("%s: change directory failed"), pwd->pw_dir);
if (!getlogindefs_bool("DEFAULT_HOME", 1))
exit(0);
if (chdir("/"))
exit(EXIT_FAILURE);
pwd->pw_dir = "/";
printf(_("Logging in with home = \"/\".\n"));
}
/* if the shell field has a space: treat it like a shell script */
if (strchr(pwd->pw_shell, ' ')) {
buff = xmalloc(strlen(pwd->pw_shell) + 6);
strcpy(buff, "exec ");
strcat(buff, pwd->pw_shell);
childArgv[childArgc++] = "/bin/sh";
childArgv[childArgc++] = "-sh";
childArgv[childArgc++] = "-c";
childArgv[childArgc++] = buff;
} else {
char tbuf[PATH_MAX + 2], *p;
tbuf[0] = '-';
xstrncpy(tbuf + 1, ((p = strrchr(pwd->pw_shell, '/')) ?
p + 1 : pwd->pw_shell), sizeof(tbuf) - 1);
childArgv[childArgc++] = pwd->pw_shell;
childArgv[childArgc++] = xstrdup(tbuf);
}
childArgv[childArgc++] = NULL;
execvp(childArgv[0], childArgv + 1);
if (!strcmp(childArgv[0], "/bin/sh"))
warn(_("couldn't exec shell script"));
else
warn(_("no shell"));
exit(EXIT_SUCCESS);
}
/**
* Do everything before the fork and do everything the exec fork
*
* @param argc The number of command line arguments
* @param argv The command line arguments
*/
void do_login(int argc, char** argv)
{
char* username = NULL;
char* hostname = NULL;
char preserve_env = 0;
int ret;
#ifdef USE_TTY_GROUP
struct group* group;
#endif
#if AUTH > 0
/* Disable echoing */
passphrase_disable_echo1(STDIN_FILENO /* Will be the terminal. */);
/* This should be done as early and quickly as possible so as little
as possible of the passphrase gets leaked to the output if the user
begins entering the passphrase directly after the username. */
#endif
/* Set process group ID */
setpgrp();
/* Parse command line arguments */
{
char double_dashed = 0;
char hostname_on_next = 0;
int i;
for (i = 1; i < argc; i++)
{
char *arg = *(argv + i);
char c;
if (*arg == 0)
;
else if ((*arg == '-') && (double_dashed == 0))
while ((c = *(++arg)))
if (c == 'H')
;
else if (c == 'V')
_exit(2);
else if (c == 'p')
preserve_env = 1;
else if (c == 'h')
{
if (*(arg + 1))
hostname = arg + 1;
else
hostname_on_next = 1;
break;
}
else if (c == 'f')
{
if (*(arg + 1))
username = arg + 1;
skip_auth = 1;
break;
}
else if (c == '-')
{
double_dashed = 1;
break;
}
else
printf("%s: unrecognised options: -%c\n", *argv, c);
else if (hostname_on_next)
{
hostname = arg;
hostname_on_next = 0;
}
else
username = arg;
}
}
/* Change that a username has been specified */
if (username == NULL)
{
printf("%s: no username specified\n", *argv);
sleep(ERROR_SLEEP);
_exit(2);
}
/* Verify that the user may login */
ret = fork_exec_wait_hook(HOOK_VERIFY, argc, argv);
if ((ret >= 0) && WIFEXITED(ret) && (WEXITSTATUS(ret) == 1))
{
sleep(ERROR_SLEEP);
_exit(2);
}
if (skip_auth)
{
/* Reset terminal settings */
passphrase_reenable_echo1(STDIN_FILENO);
/* Only root may bypass authentication */
if (getuid())
{
printf("%s: only root by use the -f option\n", *argv);
sleep(ERROR_SLEEP);
_exit(2);
}
}
/* Print ant we want a passphrase, if -f has not been used */
else
{
printf("Passphrase: ");
fflush(stdout);
}
/* Done early to make to program look like it is even faster than it is */
/* Make sure nopony is spying */
#ifdef USE_TTY_GROUP
if ((group = getgrnam(TTY_GROUP)))
tty_group = group->gr_gid;
endgrent();
#endif
secure_tty(tty_group);
#if AUTH > 0
if (skip_auth == 0)
{
/* Redisable echoing */
passphrase_disable_echo1(STDIN_FILENO);
}
#endif
/* Set up clean quiting and time out */
signal(SIGALRM, timeout_quit);
signal(SIGQUIT, user_quit);
signal(SIGINT, user_quit);
siginterrupt(SIGALRM, 1);
siginterrupt(SIGQUIT, 1);
siginterrupt(SIGINT, 1);
#if AUTH > 0
alarm(TIMEOUT_SECONDS);
#endif
/* Get user information */
if ((entry = getpwnam(username)) == NULL)
{
if (errno)
perror("getpwnam");
else
printf("User does not exist\n");
sleep(ERROR_SLEEP);
_exit(1);
}
endpwent();
username = entry->pw_name;
/* Verify passphrase or other token, if -f has not been used */
ret = 2;
#if AUTH == 0
(void) hostname;
#else
initialise_login(hostname, username, read_passphrase);
if (skip_auth == 0)
ret = authenticate_login();
/* Passphrase entered, turn off timeout */
alarm(0);
#endif
if (ret == 2)
printf("(auto-authenticated)\n");
if (ret == 0)
{
preexit();
fork_exec_wait_hook(HOOK_DENIED, argc, argv);
xsleep(FAILURE_SLEEP);
_exit(1);
}
preexit();
/* Verify account, such as that it is enabled */
verify_account();
/* Run login hook */
fork_exec_wait_hook(HOOK_LOGIN, argc, argv);
/* Partial login */
chown_tty(entry->pw_uid, tty_group, 0);
chdir_home(entry);
ensure_shell(entry);
set_environ(entry, preserve_env);
open_login_session();
/* Stop signal handling */
signal(SIGALRM, SIG_DFL);
signal(SIGQUIT, SIG_DFL);
signal(SIGTSTP, SIG_IGN);
child_pid = fork();
/* vfork cannot be used as the child changes the user,
the parent would not be able to chown the TTY */
if (child_pid == -1)
{
perror("fork");
close_login_session();
sleep(ERROR_SLEEP);
_exit(1);
}
else if (child_pid)
return; /* Do not go beyond this in the parent */
/* In case the shell does not do this */
setsid();
/* Set controlling terminal */
if (ioctl(STDIN_FILENO, TIOCSCTTY, 1))
perror("TIOCSCTTY");
signal(SIGINT, SIG_DFL);
/* Partial login */
ret = entry->pw_uid
? initgroups(username, entry->pw_gid) /* supplemental groups for user, can require network */
: setgroups(0, NULL); /* supplemental groups for root, does not require netork */
if (ret == -1)
{
perror(entry->pw_uid ? "initgroups" : "setgroups");
sleep(ERROR_SLEEP);
_exit(1);
}
set_user(entry);
exec_shell(entry);
}
