2 This file is part of systemd.
4 Copyright 2010 Lennart Poettering
6 systemd is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
11 systemd is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public License
17 along with systemd; If not, see <http://www.gnu.org/licenses/>.
24 #include <security/_pam_macros.h>
25 #include <security/pam_ext.h>
26 #include <security/pam_misc.h>
27 #include <security/pam_modules.h>
28 #include <security/pam_modutil.h>
31 #include "alloc-util.h"
32 #include "audit-util.h"
33 #include "bus-common-errors.h"
34 #include "bus-error.h"
39 #include "formats-util.h"
40 #include "hostname-util.h"
41 #include "login-util.h"
43 #include "parse-util.h"
44 #include "socket-util.h"
46 #include "terminal-util.h"
49 static int parse_argv(
51 int argc
, const char **argv
,
59 assert(argc
== 0 || argv
);
61 for (i
= 0; i
< (unsigned) argc
; i
++) {
62 if (startswith(argv
[i
], "class=")) {
66 } else if (startswith(argv
[i
], "type=")) {
70 } else if (streq(argv
[i
], "debug")) {
74 } else if (startswith(argv
[i
], "debug=")) {
77 k
= parse_boolean(argv
[i
] + 6);
79 pam_syslog(handle
, LOG_WARNING
, "Failed to parse debug= argument, ignoring.");
84 pam_syslog(handle
, LOG_WARNING
, "Unknown parameter '%s', ignoring", argv
[i
]);
90 static int get_user_data(
92 const char **ret_username
,
93 struct passwd
**ret_pw
) {
95 const char *username
= NULL
;
96 struct passwd
*pw
= NULL
;
100 assert(ret_username
);
103 r
= pam_get_user(handle
, &username
, NULL
);
104 if (r
!= PAM_SUCCESS
) {
105 pam_syslog(handle
, LOG_ERR
, "Failed to get user name.");
109 if (isempty(username
)) {
110 pam_syslog(handle
, LOG_ERR
, "User name not valid.");
114 pw
= pam_modutil_getpwnam(handle
, username
);
116 pam_syslog(handle
, LOG_ERR
, "Failed to get user data.");
117 return PAM_USER_UNKNOWN
;
121 *ret_username
= username
;
126 static int get_seat_from_display(const char *display
, const char **seat
, uint32_t *vtnr
) {
127 union sockaddr_union sa
= {
128 .un
.sun_family
= AF_UNIX
,
130 _cleanup_free_
char *p
= NULL
, *tty
= NULL
;
131 _cleanup_close_
int fd
= -1;
138 /* We deduce the X11 socket from the display name, then use
139 * SO_PEERCRED to determine the X11 server process, ask for
140 * the controlling tty of that and if it's a VC then we know
141 * the seat and the virtual terminal. Sounds ugly, is only
144 r
= socket_from_display(display
, &p
);
147 strncpy(sa
.un
.sun_path
, p
, sizeof(sa
.un
.sun_path
)-1);
149 fd
= socket(AF_UNIX
, SOCK_STREAM
|SOCK_CLOEXEC
, 0);
153 if (connect(fd
, &sa
.sa
, SOCKADDR_UN_LEN(sa
.un
)) < 0)
156 r
= getpeercred(fd
, &ucred
);
160 r
= get_ctty(ucred
.pid
, NULL
, &tty
);
164 v
= vtnr_from_tty(tty
);
172 *vtnr
= (uint32_t) v
;
177 static int export_legacy_dbus_address(
178 pam_handle_t
*handle
,
180 const char *runtime
) {
182 _cleanup_free_
char *s
= NULL
;
185 if (is_kdbus_available()) {
186 if (asprintf(&s
, KERNEL_USER_BUS_ADDRESS_FMT
";" UNIX_USER_BUS_ADDRESS_FMT
, uid
, runtime
) < 0)
189 /* FIXME: We *really* should move the access() check into the
190 * daemons that spawn dbus-daemon, instead of forcing
191 * DBUS_SESSION_BUS_ADDRESS= here. */
193 s
= strjoin(runtime
, "/bus", NULL
);
197 if (access(s
, F_OK
) < 0)
201 if (asprintf(&s
, UNIX_USER_BUS_ADDRESS_FMT
, runtime
) < 0)
205 r
= pam_misc_setenv(handle
, "DBUS_SESSION_BUS_ADDRESS", s
, 0);
206 if (r
!= PAM_SUCCESS
)
212 pam_syslog(handle
, LOG_ERR
, "Failed to set bus variable.");
216 _public_ PAM_EXTERN
int pam_sm_open_session(
217 pam_handle_t
*handle
,
219 int argc
, const char **argv
) {
221 _cleanup_(sd_bus_error_free
) sd_bus_error error
= SD_BUS_ERROR_NULL
;
222 _cleanup_(sd_bus_message_unrefp
) sd_bus_message
*reply
= NULL
;
224 *username
, *id
, *object_path
, *runtime_path
,
226 *tty
= NULL
, *display
= NULL
,
227 *remote_user
= NULL
, *remote_host
= NULL
,
229 *type
= NULL
, *class = NULL
,
230 *class_pam
= NULL
, *type_pam
= NULL
, *cvtnr
= NULL
, *desktop
= NULL
;
231 _cleanup_(sd_bus_flush_close_unrefp
) sd_bus
*bus
= NULL
;
232 int session_fd
= -1, existing
, r
;
233 bool debug
= false, remote
;
240 /* Make this a NOP on non-logind systems */
241 if (!logind_running())
244 if (parse_argv(handle
,
249 return PAM_SESSION_ERR
;
252 pam_syslog(handle
, LOG_DEBUG
, "pam-systemd initializing");
254 r
= get_user_data(handle
, &username
, &pw
);
255 if (r
!= PAM_SUCCESS
) {
256 pam_syslog(handle
, LOG_ERR
, "Failed to get user data.");
260 /* Make sure we don't enter a loop by talking to
261 * systemd-logind when it is actually waiting for the
262 * background to finish start-up. If the service is
263 * "systemd-user" we simply set XDG_RUNTIME_DIR and
266 pam_get_item(handle
, PAM_SERVICE
, (const void**) &service
);
267 if (streq_ptr(service
, "systemd-user")) {
268 _cleanup_free_
char *rt
= NULL
;
270 if (asprintf(&rt
, "/run/user/"UID_FMT
, pw
->pw_uid
) < 0)
273 r
= pam_misc_setenv(handle
, "XDG_RUNTIME_DIR", rt
, 0);
274 if (r
!= PAM_SUCCESS
) {
275 pam_syslog(handle
, LOG_ERR
, "Failed to set runtime dir.");
279 r
= export_legacy_dbus_address(handle
, pw
->pw_uid
, rt
);
280 if (r
!= PAM_SUCCESS
)
286 /* Otherwise, we ask logind to create a session for us */
288 pam_get_item(handle
, PAM_XDISPLAY
, (const void**) &display
);
289 pam_get_item(handle
, PAM_TTY
, (const void**) &tty
);
290 pam_get_item(handle
, PAM_RUSER
, (const void**) &remote_user
);
291 pam_get_item(handle
, PAM_RHOST
, (const void**) &remote_host
);
293 seat
= pam_getenv(handle
, "XDG_SEAT");
295 seat
= getenv("XDG_SEAT");
297 cvtnr
= pam_getenv(handle
, "XDG_VTNR");
299 cvtnr
= getenv("XDG_VTNR");
301 type
= pam_getenv(handle
, "XDG_SESSION_TYPE");
303 type
= getenv("XDG_SESSION_TYPE");
307 class = pam_getenv(handle
, "XDG_SESSION_CLASS");
309 class = getenv("XDG_SESSION_CLASS");
313 desktop
= pam_getenv(handle
, "XDG_SESSION_DESKTOP");
314 if (isempty(desktop
))
315 desktop
= getenv("XDG_SESSION_DESKTOP");
319 if (strchr(tty
, ':')) {
320 /* A tty with a colon is usually an X11 display,
321 * placed there to show up in utmp. We rearrange
322 * things and don't pretend that an X display was a
325 if (isempty(display
))
328 } else if (streq(tty
, "cron")) {
329 /* cron has been setting PAM_TTY to "cron" for a very
330 * long time and it probably shouldn't stop doing that
331 * for compatibility reasons. */
332 type
= "unspecified";
333 class = "background";
335 } else if (streq(tty
, "ssh")) {
336 /* ssh has been setting PAM_TTY to "ssh" for a very
337 * long time and probably shouldn't stop doing that
338 * for compatibility reasons. */
344 /* If this fails vtnr will be 0, that's intended */
346 (void) safe_atou32(cvtnr
, &vtnr
);
348 if (!isempty(display
) && !vtnr
) {
350 get_seat_from_display(display
, &seat
, &vtnr
);
351 else if (streq(seat
, "seat0"))
352 get_seat_from_display(display
, NULL
, &vtnr
);
355 if (seat
&& !streq(seat
, "seat0") && vtnr
!= 0) {
356 pam_syslog(handle
, LOG_DEBUG
, "Ignoring vtnr %"PRIu32
" for %s which is not seat0", vtnr
, seat
);
361 type
= !isempty(display
) ? "x11" :
362 !isempty(tty
) ? "tty" : "unspecified";
365 class = streq(type
, "unspecified") ? "background" : "user";
367 remote
= !isempty(remote_host
) && !is_localhost(remote_host
);
369 /* Talk to logind over the message bus */
371 r
= sd_bus_open_system(&bus
);
373 pam_syslog(handle
, LOG_ERR
, "Failed to connect to system bus: %s", strerror(-r
));
374 return PAM_SESSION_ERR
;
378 pam_syslog(handle
, LOG_DEBUG
, "Asking logind to create session: "
379 "uid="UID_FMT
" pid="PID_FMT
" service=%s type=%s class=%s desktop=%s seat=%s vtnr=%"PRIu32
" tty=%s display=%s remote=%s remote_user=%s remote_host=%s",
380 pw
->pw_uid
, getpid(),
382 type
, class, strempty(desktop
),
383 strempty(seat
), vtnr
, strempty(tty
), strempty(display
),
384 yes_no(remote
), strempty(remote_user
), strempty(remote_host
));
386 r
= sd_bus_call_method(bus
,
387 "org.freedesktop.login1",
388 "/org/freedesktop/login1",
389 "org.freedesktop.login1.Manager",
393 "uusssssussbssa(sv)",
394 (uint32_t) pw
->pw_uid
,
409 if (sd_bus_error_has_name(&error
, BUS_ERROR_SESSION_BUSY
)) {
410 pam_syslog(handle
, LOG_DEBUG
, "Cannot create session: %s", bus_error_message(&error
, r
));
413 pam_syslog(handle
, LOG_ERR
, "Failed to create session: %s", bus_error_message(&error
, r
));
414 return PAM_SYSTEM_ERR
;
418 r
= sd_bus_message_read(reply
,
429 pam_syslog(handle
, LOG_ERR
, "Failed to parse message: %s", strerror(-r
));
430 return PAM_SESSION_ERR
;
434 pam_syslog(handle
, LOG_DEBUG
, "Reply from logind: "
435 "id=%s object_path=%s runtime_path=%s session_fd=%d seat=%s vtnr=%u original_uid=%u",
436 id
, object_path
, runtime_path
, session_fd
, seat
, vtnr
, original_uid
);
438 r
= pam_misc_setenv(handle
, "XDG_SESSION_ID", id
, 0);
439 if (r
!= PAM_SUCCESS
) {
440 pam_syslog(handle
, LOG_ERR
, "Failed to set session id.");
444 if (original_uid
== pw
->pw_uid
) {
445 /* Don't set $XDG_RUNTIME_DIR if the user we now
446 * authenticated for does not match the original user
447 * of the session. We do this in order not to result
448 * in privileged apps clobbering the runtime directory
451 r
= pam_misc_setenv(handle
, "XDG_RUNTIME_DIR", runtime_path
, 0);
452 if (r
!= PAM_SUCCESS
) {
453 pam_syslog(handle
, LOG_ERR
, "Failed to set runtime dir.");
457 r
= export_legacy_dbus_address(handle
, pw
->pw_uid
, runtime_path
);
458 if (r
!= PAM_SUCCESS
)
462 if (!isempty(seat
)) {
463 r
= pam_misc_setenv(handle
, "XDG_SEAT", seat
, 0);
464 if (r
!= PAM_SUCCESS
) {
465 pam_syslog(handle
, LOG_ERR
, "Failed to set seat.");
471 char buf
[DECIMAL_STR_MAX(vtnr
)];
472 sprintf(buf
, "%u", vtnr
);
474 r
= pam_misc_setenv(handle
, "XDG_VTNR", buf
, 0);
475 if (r
!= PAM_SUCCESS
) {
476 pam_syslog(handle
, LOG_ERR
, "Failed to set virtual terminal number.");
481 r
= pam_set_data(handle
, "systemd.existing", INT_TO_PTR(!!existing
), NULL
);
482 if (r
!= PAM_SUCCESS
) {
483 pam_syslog(handle
, LOG_ERR
, "Failed to install existing flag.");
487 if (session_fd
>= 0) {
488 session_fd
= fcntl(session_fd
, F_DUPFD_CLOEXEC
, 3);
489 if (session_fd
< 0) {
490 pam_syslog(handle
, LOG_ERR
, "Failed to dup session fd: %m");
491 return PAM_SESSION_ERR
;
494 r
= pam_set_data(handle
, "systemd.session-fd", FD_TO_PTR(session_fd
), NULL
);
495 if (r
!= PAM_SUCCESS
) {
496 pam_syslog(handle
, LOG_ERR
, "Failed to install session fd.");
497 safe_close(session_fd
);
505 _public_ PAM_EXTERN
int pam_sm_close_session(
506 pam_handle_t
*handle
,
508 int argc
, const char **argv
) {
510 _cleanup_(sd_bus_error_free
) sd_bus_error error
= SD_BUS_ERROR_NULL
;
511 _cleanup_(sd_bus_flush_close_unrefp
) sd_bus
*bus
= NULL
;
512 const void *existing
= NULL
;
518 /* Only release session if it wasn't pre-existing when we
519 * tried to create it */
520 pam_get_data(handle
, "systemd.existing", &existing
);
522 id
= pam_getenv(handle
, "XDG_SESSION_ID");
523 if (id
&& !existing
) {
525 /* Before we go and close the FIFO we need to tell
526 * logind that this is a clean session shutdown, so
527 * that it doesn't just go and slaughter us
528 * immediately after closing the fd */
530 r
= sd_bus_open_system(&bus
);
532 pam_syslog(handle
, LOG_ERR
, "Failed to connect to system bus: %s", strerror(-r
));
533 return PAM_SESSION_ERR
;
536 r
= sd_bus_call_method(bus
,
537 "org.freedesktop.login1",
538 "/org/freedesktop/login1",
539 "org.freedesktop.login1.Manager",
546 pam_syslog(handle
, LOG_ERR
, "Failed to release session: %s", bus_error_message(&error
, r
));
547 return PAM_SESSION_ERR
;
551 /* Note that we are knowingly leaking the FIFO fd here. This
552 * way, logind can watch us die. If we closed it here it would
553 * not have any clue when that is completed. Given that one
554 * cannot really have multiple PAM sessions open from the same
555 * process this means we will leak one FD at max. */