977 lines
25 KiB
C
977 lines
25 KiB
C
/* su for Linux. Run a shell with substitute user and group IDs.
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Copyright (C) 1992-2006 Free Software Foundation, Inc.
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Copyright (C) 2012 SUSE Linux Products GmbH, Nuernberg
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
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/* Run a shell with the real and effective UID and GID and groups
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of USER, default `root'.
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The shell run is taken from USER's password entry, /bin/sh if
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none is specified there. If the account has a password, su
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prompts for a password unless run by a user with real UID 0.
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Does not change the current directory.
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Sets `HOME' and `SHELL' from the password entry for USER, and if
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USER is not root, sets `USER' and `LOGNAME' to USER.
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The subshell is not a login shell.
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If one or more ARGs are given, they are passed as additional
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arguments to the subshell.
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Does not handle /bin/sh or other shells specially
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(setting argv[0] to "-su", passing -c only to certain shells, etc.).
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I don't see the point in doing that, and it's ugly.
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Based on an implemenation by David MacKenzie <djm@gnu.ai.mit.edu>. */
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enum
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{
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EXIT_CANNOT_INVOKE = 126,
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EXIT_ENOENT = 127
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};
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#include <config.h>
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#include <stdio.h>
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#include <getopt.h>
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#include <sys/types.h>
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#include <pwd.h>
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#include <grp.h>
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#include <security/pam_appl.h>
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#include <security/pam_misc.h>
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#include <signal.h>
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#include <sys/wait.h>
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#include <syslog.h>
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#include <utmp.h>
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#include "err.h"
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#include <stdbool.h>
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#include "c.h"
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#include "xalloc.h"
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#include "nls.h"
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#include "pathnames.h"
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#include "env.h"
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#include "closestream.h"
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#include "strutils.h"
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#include "ttyutils.h"
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/* name of the pam configuration files. separate configs for su and su - */
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#define PAM_SRVNAME_SU "su"
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#define PAM_SRVNAME_SU_L "su-l"
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#define PAM_SRVNAME_RUNUSER "runuser"
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#define PAM_SRVNAME_RUNUSER_L "runuser-l"
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#define _PATH_LOGINDEFS_SU "/etc/defaults/su"
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#define _PATH_LOGINDEFS_RUNUSER "/etc/defaults/runuser"
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#define is_pam_failure(_rc) ((_rc) != PAM_SUCCESS)
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#include "logindefs.h"
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#include "su-common.h"
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/* The shell to run if none is given in the user's passwd entry. */
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#define DEFAULT_SHELL "/bin/sh"
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/* The user to become if none is specified. */
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#define DEFAULT_USER "root"
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#ifndef HAVE_ENVIRON_DECL
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extern char **environ;
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#endif
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static void run_shell (char const *, char const *, char **, size_t)
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__attribute__ ((__noreturn__));
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/* If true, pass the `-f' option to the subshell. */
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static bool fast_startup;
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/* If true, simulate a login instead of just starting a shell. */
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static bool simulate_login;
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/* If true, change some environment vars to indicate the user su'd to. */
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static bool change_environment;
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/* If true, then don't call setsid() with a command. */
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static int same_session = 0;
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/* SU_MODE_{RUNUSER,SU} */
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static int su_mode;
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/* Don't print PAM info messages (Last login, etc.). */
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static int suppress_pam_info;
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static bool _pam_session_opened;
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static bool _pam_cred_established;
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static sig_atomic_t volatile caught_signal = false;
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static pam_handle_t *pamh = NULL;
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static int restricted = 1; /* zero for root user */
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static struct passwd *
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current_getpwuid(void)
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{
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uid_t ruid;
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/* GNU Hurd implementation has an extension where a process can exist in a
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* non-conforming environment, and thus be outside the realms of POSIX
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* process identifiers; on this platform, getuid() fails with a status of
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* (uid_t)(-1) and sets errno if a program is run from a non-conforming
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* environment.
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*
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* http://austingroupbugs.net/view.php?id=511
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*/
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errno = 0;
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ruid = getuid ();
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return errno == 0 ? getpwuid (ruid) : NULL;
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}
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/* Log the fact that someone has run su to the user given by PW;
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if SUCCESSFUL is true, they gave the correct password, etc. */
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static void
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log_syslog(struct passwd const *pw, bool successful)
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{
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const char *new_user, *old_user, *tty;
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new_user = pw->pw_name;
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/* The utmp entry (via getlogin) is probably the best way to identify
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the user, especially if someone su's from a su-shell. */
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old_user = getlogin ();
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if (!old_user)
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{
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/* getlogin can fail -- usually due to lack of utmp entry.
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Resort to getpwuid. */
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struct passwd *pwd = current_getpwuid();
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old_user = pwd ? pwd->pw_name : "";
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}
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if (get_terminal_name(STDERR_FILENO, NULL, &tty, NULL) != 0 || !tty)
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tty = "none";
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openlog (program_invocation_short_name, 0 , LOG_AUTH);
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syslog (LOG_NOTICE, "%s(to %s) %s on %s",
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successful ? "" :
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su_mode == RUNUSER_MODE ? "FAILED RUNUSER " : "FAILED SU ",
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new_user, old_user, tty);
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closelog ();
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}
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/*
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* Log failed login attempts in _PATH_BTMP if that exists.
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*/
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static void log_btmp(struct passwd const *pw)
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{
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struct utmp ut;
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struct timeval tv;
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const char *tty_name, *tty_num;
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memset(&ut, 0, sizeof(ut));
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strncpy(ut.ut_user,
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pw && pw->pw_name ? pw->pw_name : "(unknown)",
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sizeof(ut.ut_user));
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get_terminal_name(STDERR_FILENO, NULL, &tty_name, &tty_num);
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if (tty_num)
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xstrncpy(ut.ut_id, tty_num, sizeof(ut.ut_id));
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if (tty_name)
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xstrncpy(ut.ut_line, tty_name, sizeof(ut.ut_line));
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#if defined(_HAVE_UT_TV) /* in <utmpbits.h> included by <utmp.h> */
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gettimeofday(&tv, NULL);
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ut.ut_tv.tv_sec = tv.tv_sec;
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ut.ut_tv.tv_usec = tv.tv_usec;
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#else
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{
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time_t t;
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time(&t);
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ut.ut_time = t; /* ut_time is not always a time_t */
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}
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#endif
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ut.ut_type = LOGIN_PROCESS; /* XXX doesn't matter */
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ut.ut_pid = getpid();
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updwtmp(_PATH_BTMP, &ut);
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}
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static int su_pam_conv(int num_msg, const struct pam_message **msg,
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struct pam_response **resp, void *appdata_ptr)
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{
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if (suppress_pam_info
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&& num_msg == 1
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&& msg
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&& msg[0]->msg_style == PAM_TEXT_INFO)
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return PAM_SUCCESS;
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return misc_conv(num_msg, msg, resp, appdata_ptr);
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}
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static struct pam_conv conv =
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{
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su_pam_conv,
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NULL
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};
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static void
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cleanup_pam (int retcode)
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{
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int saved_errno = errno;
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if (_pam_session_opened)
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pam_close_session (pamh, 0);
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if (_pam_cred_established)
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pam_setcred (pamh, PAM_DELETE_CRED | PAM_SILENT);
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pam_end(pamh, retcode);
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errno = saved_errno;
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}
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/* Signal handler for parent process. */
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static void
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su_catch_sig (int sig)
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{
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caught_signal = sig;
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}
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/* Export env variables declared by PAM modules. */
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static void
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export_pamenv (void)
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{
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char **env;
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/* This is a copy but don't care to free as we exec later anyways. */
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env = pam_getenvlist (pamh);
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while (env && *env)
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{
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if (putenv (*env) != 0)
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err (EXIT_FAILURE, NULL);
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env++;
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}
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}
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static void
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create_watching_parent (void)
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{
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pid_t child;
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sigset_t ourset;
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struct sigaction oldact[3];
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int status = 0;
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int retval;
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retval = pam_open_session (pamh, 0);
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if (is_pam_failure(retval))
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{
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cleanup_pam (retval);
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errx (EXIT_FAILURE, _("cannot open session: %s"),
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pam_strerror (pamh, retval));
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}
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else
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_pam_session_opened = 1;
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memset(oldact, 0, sizeof(oldact));
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child = fork ();
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if (child == (pid_t) -1)
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{
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cleanup_pam (PAM_ABORT);
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err (EXIT_FAILURE, _("cannot create child process"));
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}
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/* the child proceeds to run the shell */
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if (child == 0)
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return;
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/* In the parent watch the child. */
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/* su without pam support does not have a helper that keeps
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sitting on any directory so let's go to /. */
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if (chdir ("/") != 0)
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warn (_("cannot change directory to %s"), "/");
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sigfillset (&ourset);
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if (sigprocmask (SIG_BLOCK, &ourset, NULL))
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{
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warn (_("cannot block signals"));
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caught_signal = true;
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}
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if (!caught_signal)
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{
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struct sigaction action;
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action.sa_handler = su_catch_sig;
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sigemptyset (&action.sa_mask);
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action.sa_flags = 0;
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sigemptyset (&ourset);
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if (!same_session)
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{
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if (sigaddset(&ourset, SIGINT) || sigaddset(&ourset, SIGQUIT))
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{
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warn (_("cannot set signal handler"));
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caught_signal = true;
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}
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}
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if (!caught_signal && (sigaddset(&ourset, SIGTERM)
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|| sigaddset(&ourset, SIGALRM)
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|| sigaction(SIGTERM, &action, &oldact[0])
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|| sigprocmask(SIG_UNBLOCK, &ourset, NULL))) {
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warn (_("cannot set signal handler"));
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caught_signal = true;
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}
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if (!caught_signal && !same_session && (sigaction(SIGINT, &action, &oldact[1])
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|| sigaction(SIGQUIT, &action, &oldact[2])))
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{
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warn (_("cannot set signal handler"));
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caught_signal = true;
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}
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}
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if (!caught_signal)
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{
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pid_t pid;
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for (;;)
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{
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pid = waitpid (child, &status, WUNTRACED);
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if (pid != (pid_t)-1 && WIFSTOPPED (status))
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{
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kill (getpid (), SIGSTOP);
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/* once we get here, we must have resumed */
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kill (pid, SIGCONT);
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}
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else
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break;
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}
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if (pid != (pid_t)-1)
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{
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if (WIFSIGNALED (status))
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{
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status = WTERMSIG (status) + 128;
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if (WCOREDUMP (status))
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fprintf (stderr, _("%s (core dumped)\n"),
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strsignal (WTERMSIG (status)));
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}
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else
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status = WEXITSTATUS (status);
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}
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else if (caught_signal)
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status = caught_signal + 128;
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else
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status = 1;
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}
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else
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status = 1;
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if (caught_signal)
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{
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fprintf (stderr, _("\nSession terminated, killing shell..."));
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kill (child, SIGTERM);
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}
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cleanup_pam (PAM_SUCCESS);
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|
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if (caught_signal)
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{
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sleep (2);
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kill (child, SIGKILL);
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fprintf (stderr, _(" ...killed.\n"));
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|
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/* Let's terminate itself with the received signal.
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*
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* It seems that shells use WIFSIGNALED() rather than our exit status
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* value to detect situations when is necessary to cleanup (reset)
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* terminal settings (kzak -- Jun 2013).
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*/
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switch (caught_signal) {
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case SIGTERM:
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sigaction(SIGTERM, &oldact[0], NULL);
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break;
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case SIGINT:
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sigaction(SIGINT, &oldact[1], NULL);
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break;
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case SIGQUIT:
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sigaction(SIGQUIT, &oldact[2], NULL);
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break;
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default:
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/* just in case that signal stuff initialization failed and
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* caught_signal = true */
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caught_signal = SIGKILL;
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break;
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}
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kill(getpid(), caught_signal);
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}
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exit (status);
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}
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static void
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authenticate (const struct passwd *pw)
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{
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const struct passwd *lpw = NULL;
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const char *cp, *srvname = NULL;
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int retval;
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switch (su_mode) {
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case SU_MODE:
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srvname = simulate_login ? PAM_SRVNAME_SU_L : PAM_SRVNAME_SU;
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break;
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case RUNUSER_MODE:
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srvname = simulate_login ? PAM_SRVNAME_RUNUSER_L : PAM_SRVNAME_RUNUSER;
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break;
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default:
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abort();
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break;
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}
|
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|
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retval = pam_start (srvname, pw->pw_name, &conv, &pamh);
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if (is_pam_failure(retval))
|
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goto done;
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|
|
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if (isatty (0) && (cp = ttyname (0)) != NULL)
|
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{
|
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const char *tty;
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|
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if (strncmp (cp, "/dev/", 5) == 0)
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tty = cp + 5;
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else
|
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tty = cp;
|
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retval = pam_set_item (pamh, PAM_TTY, tty);
|
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if (is_pam_failure(retval))
|
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goto done;
|
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}
|
|
|
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lpw = current_getpwuid ();
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if (lpw && lpw->pw_name)
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{
|
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retval = pam_set_item (pamh, PAM_RUSER, (const void *) lpw->pw_name);
|
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if (is_pam_failure(retval))
|
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goto done;
|
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}
|
|
|
|
if (su_mode == RUNUSER_MODE)
|
|
{
|
|
/*
|
|
* This is the only difference between runuser(1) and su(1). The command
|
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* runuser(1) does not required authentication, because user is root.
|
|
*/
|
|
if (restricted)
|
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errx(EXIT_FAILURE, _("may not be used by non-root users"));
|
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return;
|
|
}
|
|
|
|
retval = pam_authenticate (pamh, 0);
|
|
if (is_pam_failure(retval))
|
|
goto done;
|
|
|
|
retval = pam_acct_mgmt (pamh, 0);
|
|
if (retval == PAM_NEW_AUTHTOK_REQD)
|
|
{
|
|
/* Password has expired. Offer option to change it. */
|
|
retval = pam_chauthtok (pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
|
|
}
|
|
|
|
done:
|
|
|
|
log_syslog(pw, !is_pam_failure(retval));
|
|
|
|
if (is_pam_failure(retval))
|
|
{
|
|
const char *msg;
|
|
|
|
log_btmp(pw);
|
|
|
|
msg = pam_strerror(pamh, retval);
|
|
pam_end(pamh, retval);
|
|
sleep (getlogindefs_num ("FAIL_DELAY", 1));
|
|
errx (EXIT_FAILURE, "%s", msg?msg:_("incorrect password"));
|
|
}
|
|
}
|
|
|
|
static void
|
|
set_path(const struct passwd* pw)
|
|
{
|
|
int r;
|
|
if (pw->pw_uid)
|
|
r = logindefs_setenv("PATH", "ENV_PATH", _PATH_DEFPATH);
|
|
|
|
else if ((r = logindefs_setenv("PATH", "ENV_ROOTPATH", NULL)) != 0)
|
|
r = logindefs_setenv("PATH", "ENV_SUPATH", _PATH_DEFPATH_ROOT);
|
|
|
|
if (r != 0)
|
|
err (EXIT_FAILURE, _("failed to set PATH"));
|
|
}
|
|
|
|
/* Update `environ' for the new shell based on PW, with SHELL being
|
|
the value for the SHELL environment variable. */
|
|
|
|
static void
|
|
modify_environment (const struct passwd *pw, const char *shell)
|
|
{
|
|
if (simulate_login)
|
|
{
|
|
/* Leave TERM unchanged. Set HOME, SHELL, USER, LOGNAME, PATH.
|
|
Unset all other environment variables. */
|
|
char const *term = getenv ("TERM");
|
|
if (term)
|
|
term = xstrdup (term);
|
|
environ = xmalloc ((6 + !!term) * sizeof (char *));
|
|
environ[0] = NULL;
|
|
if (term)
|
|
xsetenv ("TERM", term, 1);
|
|
xsetenv ("HOME", pw->pw_dir, 1);
|
|
if (shell)
|
|
xsetenv ("SHELL", shell, 1);
|
|
xsetenv ("USER", pw->pw_name, 1);
|
|
xsetenv ("LOGNAME", pw->pw_name, 1);
|
|
set_path(pw);
|
|
}
|
|
else
|
|
{
|
|
/* Set HOME, SHELL, and (if not becoming a superuser)
|
|
USER and LOGNAME. */
|
|
if (change_environment)
|
|
{
|
|
xsetenv ("HOME", pw->pw_dir, 1);
|
|
if (shell)
|
|
xsetenv ("SHELL", shell, 1);
|
|
if (getlogindefs_bool ("ALWAYS_SET_PATH", 0))
|
|
set_path(pw);
|
|
|
|
if (pw->pw_uid)
|
|
{
|
|
xsetenv ("USER", pw->pw_name, 1);
|
|
xsetenv ("LOGNAME", pw->pw_name, 1);
|
|
}
|
|
}
|
|
}
|
|
|
|
export_pamenv ();
|
|
}
|
|
|
|
/* Become the user and group(s) specified by PW. */
|
|
|
|
static void
|
|
init_groups (const struct passwd *pw, gid_t *groups, int num_groups)
|
|
{
|
|
int retval;
|
|
|
|
errno = 0;
|
|
|
|
if (num_groups)
|
|
retval = setgroups (num_groups, groups);
|
|
else
|
|
retval = initgroups (pw->pw_name, pw->pw_gid);
|
|
|
|
if (retval == -1)
|
|
{
|
|
cleanup_pam (PAM_ABORT);
|
|
err (EXIT_FAILURE, _("cannot set groups"));
|
|
}
|
|
endgrent ();
|
|
|
|
retval = pam_setcred (pamh, PAM_ESTABLISH_CRED);
|
|
if (is_pam_failure(retval))
|
|
errx (EXIT_FAILURE, "%s", pam_strerror (pamh, retval));
|
|
else
|
|
_pam_cred_established = 1;
|
|
}
|
|
|
|
static void
|
|
change_identity (const struct passwd *pw)
|
|
{
|
|
if (setgid (pw->pw_gid))
|
|
err (EXIT_FAILURE, _("cannot set group id"));
|
|
if (setuid (pw->pw_uid))
|
|
err (EXIT_FAILURE, _("cannot set user id"));
|
|
}
|
|
|
|
/* Run SHELL, or DEFAULT_SHELL if SHELL is empty.
|
|
If COMMAND is nonzero, pass it to the shell with the -c option.
|
|
Pass ADDITIONAL_ARGS to the shell as more arguments; there
|
|
are N_ADDITIONAL_ARGS extra arguments. */
|
|
|
|
static void
|
|
run_shell (char const *shell, char const *command, char **additional_args,
|
|
size_t n_additional_args)
|
|
{
|
|
size_t n_args = 1 + fast_startup + 2 * !!command + n_additional_args + 1;
|
|
char const **args = xcalloc (n_args, sizeof *args);
|
|
size_t argno = 1;
|
|
|
|
if (simulate_login)
|
|
{
|
|
char *arg0;
|
|
char *shell_basename;
|
|
|
|
shell_basename = basename (shell);
|
|
arg0 = xmalloc (strlen (shell_basename) + 2);
|
|
arg0[0] = '-';
|
|
strcpy (arg0 + 1, shell_basename);
|
|
args[0] = arg0;
|
|
}
|
|
else
|
|
args[0] = basename (shell);
|
|
if (fast_startup)
|
|
args[argno++] = "-f";
|
|
if (command)
|
|
{
|
|
args[argno++] = "-c";
|
|
args[argno++] = command;
|
|
}
|
|
memcpy (args + argno, additional_args, n_additional_args * sizeof *args);
|
|
args[argno + n_additional_args] = NULL;
|
|
execv (shell, (char **) args);
|
|
|
|
{
|
|
int exit_status = (errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE);
|
|
warn (_("failed to execute %s"), shell);
|
|
exit (exit_status);
|
|
}
|
|
}
|
|
|
|
/* Return true if SHELL is a restricted shell (one not returned by
|
|
getusershell), else false, meaning it is a standard shell. */
|
|
|
|
static bool
|
|
restricted_shell (const char *shell)
|
|
{
|
|
char *line;
|
|
|
|
setusershell ();
|
|
while ((line = getusershell ()) != NULL)
|
|
{
|
|
if (*line != '#' && !strcmp (line, shell))
|
|
{
|
|
endusershell ();
|
|
return false;
|
|
}
|
|
}
|
|
endusershell ();
|
|
return true;
|
|
}
|
|
|
|
static void __attribute__((__noreturn__))
|
|
usage (int status)
|
|
{
|
|
if (su_mode == RUNUSER_MODE) {
|
|
fputs(USAGE_HEADER, stdout);
|
|
printf (_(" %s [options] -u <user> <command>\n"), program_invocation_short_name);
|
|
printf (_(" %s [options] [-] [<user> [<argument>...]]\n"), program_invocation_short_name);
|
|
fputs (_("\n"
|
|
"Run <command> with the effective user ID and group ID of <user>. If -u is\n"
|
|
"not given, fall back to su(1)-compatible semantics and execute standard shell.\n"
|
|
"The options -c, -f, -l, and -s are mutually exclusive with -u.\n"), stdout);
|
|
|
|
fputs(USAGE_OPTIONS, stdout);
|
|
|
|
fputs (_(" -u, --user <user> username\n"), stdout);
|
|
|
|
} else {
|
|
fputs(USAGE_HEADER, stdout);
|
|
printf (_(" %s [options] [-] [<user> [<argument>...]]\n"), program_invocation_short_name);
|
|
fputs (_("\n"
|
|
"Change the effective user ID and group ID to that of <user>.\n"
|
|
"A mere - implies -l. If <user> is not given, root is assumed.\n"), stdout);
|
|
|
|
fputs(USAGE_OPTIONS, stdout);
|
|
}
|
|
|
|
fputs (_(" -m, -p, --preserve-environment do not reset environment variables\n"), stdout);
|
|
fputs (_(" -g, --group <group> specify the primary group\n"), stdout);
|
|
fputs (_(" -G, --supp-group <group> specify a supplemental group\n\n"), stdout);
|
|
|
|
fputs (_(" -, -l, --login make the shell a login shell\n"), stdout);
|
|
fputs (_(" -c, --command <command> pass a single command to the shell with -c\n"), stdout);
|
|
fputs (_(" --session-command <command> pass a single command to the shell with -c\n"
|
|
" and do not create a new session\n"), stdout);
|
|
fputs (_(" -f, --fast pass -f to the shell (for csh or tcsh)\n"), stdout);
|
|
fputs (_(" -s, --shell <shell> run <shell> if /etc/shells allows it\n"), stdout);
|
|
|
|
fputs(USAGE_SEPARATOR, stdout);
|
|
fputs(USAGE_HELP, stdout);
|
|
fputs(USAGE_VERSION, stdout);
|
|
printf(USAGE_MAN_TAIL(su_mode == SU_MODE ? "su(1)" : "runuser(1)"));
|
|
exit (status);
|
|
}
|
|
|
|
static
|
|
void load_config(void)
|
|
{
|
|
switch (su_mode) {
|
|
case SU_MODE:
|
|
logindefs_load_file(_PATH_LOGINDEFS_SU);
|
|
break;
|
|
case RUNUSER_MODE:
|
|
logindefs_load_file(_PATH_LOGINDEFS_RUNUSER);
|
|
break;
|
|
}
|
|
|
|
logindefs_load_file(_PATH_LOGINDEFS);
|
|
}
|
|
|
|
/*
|
|
* Returns 1 if the current user is not root
|
|
*/
|
|
static int
|
|
evaluate_uid(void)
|
|
{
|
|
uid_t ruid = getuid();
|
|
uid_t euid = geteuid();
|
|
|
|
/* if we're really root and aren't running setuid */
|
|
return (uid_t) 0 == ruid && ruid == euid ? 0 : 1;
|
|
}
|
|
|
|
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;
|
|
|
|
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'},
|
|
{"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", 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':
|
|
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(_("ignore --preserve-environment, it's mutually exclusive to --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, _("COMMAND not 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 {
|
|
execvp(argv[optind], &argv[optind]);
|
|
err(EXIT_FAILURE, _("failed to execute %s"), argv[optind]);
|
|
}
|
|
}
|
|
|
|
// vim: sw=2 cinoptions=>4,n-2,{2,^-2,\:2,=2,g0,h2,p5,t0,+2,(0,u0,w1,m1
|