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 /* FIXME: We *really* should move the access() check into the
186 * daemons that spawn dbus-daemon, instead of forcing
187 * DBUS_SESSION_BUS_ADDRESS= here. */
189 s
= strjoin(runtime
, "/bus", NULL
);
193 if (access(s
, F_OK
) < 0)
197 if (asprintf(&s
, UNIX_USER_BUS_ADDRESS_FMT
, runtime
) < 0)
200 r
= pam_misc_setenv(handle
, "DBUS_SESSION_BUS_ADDRESS", s
, 0);
201 if (r
!= PAM_SUCCESS
)
207 pam_syslog(handle
, LOG_ERR
, "Failed to set bus variable.");
211 _public_ PAM_EXTERN
int pam_sm_open_session(
212 pam_handle_t
*handle
,
214 int argc
, const char **argv
) {
216 _cleanup_(sd_bus_error_free
) sd_bus_error error
= SD_BUS_ERROR_NULL
;
217 _cleanup_(sd_bus_message_unrefp
) sd_bus_message
*reply
= NULL
;
219 *username
, *id
, *object_path
, *runtime_path
,
221 *tty
= NULL
, *display
= NULL
,
222 *remote_user
= NULL
, *remote_host
= NULL
,
224 *type
= NULL
, *class = NULL
,
225 *class_pam
= NULL
, *type_pam
= NULL
, *cvtnr
= NULL
, *desktop
= NULL
;
226 _cleanup_(sd_bus_flush_close_unrefp
) sd_bus
*bus
= NULL
;
227 int session_fd
= -1, existing
, r
;
228 bool debug
= false, remote
;
235 /* Make this a NOP on non-logind systems */
236 if (!logind_running())
239 if (parse_argv(handle
,
244 return PAM_SESSION_ERR
;
247 pam_syslog(handle
, LOG_DEBUG
, "pam-systemd initializing");
249 r
= get_user_data(handle
, &username
, &pw
);
250 if (r
!= PAM_SUCCESS
) {
251 pam_syslog(handle
, LOG_ERR
, "Failed to get user data.");
255 /* Make sure we don't enter a loop by talking to
256 * systemd-logind when it is actually waiting for the
257 * background to finish start-up. If the service is
258 * "systemd-user" we simply set XDG_RUNTIME_DIR and
261 pam_get_item(handle
, PAM_SERVICE
, (const void**) &service
);
262 if (streq_ptr(service
, "systemd-user")) {
263 _cleanup_free_
char *rt
= NULL
;
265 if (asprintf(&rt
, "/run/user/"UID_FMT
, pw
->pw_uid
) < 0)
268 r
= pam_misc_setenv(handle
, "XDG_RUNTIME_DIR", rt
, 0);
269 if (r
!= PAM_SUCCESS
) {
270 pam_syslog(handle
, LOG_ERR
, "Failed to set runtime dir.");
274 r
= export_legacy_dbus_address(handle
, pw
->pw_uid
, rt
);
275 if (r
!= PAM_SUCCESS
)
281 /* Otherwise, we ask logind to create a session for us */
283 pam_get_item(handle
, PAM_XDISPLAY
, (const void**) &display
);
284 pam_get_item(handle
, PAM_TTY
, (const void**) &tty
);
285 pam_get_item(handle
, PAM_RUSER
, (const void**) &remote_user
);
286 pam_get_item(handle
, PAM_RHOST
, (const void**) &remote_host
);
288 seat
= pam_getenv(handle
, "XDG_SEAT");
290 seat
= getenv("XDG_SEAT");
292 cvtnr
= pam_getenv(handle
, "XDG_VTNR");
294 cvtnr
= getenv("XDG_VTNR");
296 type
= pam_getenv(handle
, "XDG_SESSION_TYPE");
298 type
= getenv("XDG_SESSION_TYPE");
302 class = pam_getenv(handle
, "XDG_SESSION_CLASS");
304 class = getenv("XDG_SESSION_CLASS");
308 desktop
= pam_getenv(handle
, "XDG_SESSION_DESKTOP");
309 if (isempty(desktop
))
310 desktop
= getenv("XDG_SESSION_DESKTOP");
314 if (strchr(tty
, ':')) {
315 /* A tty with a colon is usually an X11 display,
316 * placed there to show up in utmp. We rearrange
317 * things and don't pretend that an X display was a
320 if (isempty(display
))
323 } else if (streq(tty
, "cron")) {
324 /* cron has been setting PAM_TTY to "cron" for a very
325 * long time and it probably shouldn't stop doing that
326 * for compatibility reasons. */
327 type
= "unspecified";
328 class = "background";
330 } else if (streq(tty
, "ssh")) {
331 /* ssh has been setting PAM_TTY to "ssh" for a very
332 * long time and probably shouldn't stop doing that
333 * for compatibility reasons. */
339 /* If this fails vtnr will be 0, that's intended */
341 (void) safe_atou32(cvtnr
, &vtnr
);
343 if (!isempty(display
) && !vtnr
) {
345 get_seat_from_display(display
, &seat
, &vtnr
);
346 else if (streq(seat
, "seat0"))
347 get_seat_from_display(display
, NULL
, &vtnr
);
350 if (seat
&& !streq(seat
, "seat0") && vtnr
!= 0) {
351 pam_syslog(handle
, LOG_DEBUG
, "Ignoring vtnr %"PRIu32
" for %s which is not seat0", vtnr
, seat
);
356 type
= !isempty(display
) ? "x11" :
357 !isempty(tty
) ? "tty" : "unspecified";
360 class = streq(type
, "unspecified") ? "background" : "user";
362 remote
= !isempty(remote_host
) && !is_localhost(remote_host
);
364 /* Talk to logind over the message bus */
366 r
= sd_bus_open_system(&bus
);
368 pam_syslog(handle
, LOG_ERR
, "Failed to connect to system bus: %s", strerror(-r
));
369 return PAM_SESSION_ERR
;
373 pam_syslog(handle
, LOG_DEBUG
, "Asking logind to create session: "
374 "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",
375 pw
->pw_uid
, getpid(),
377 type
, class, strempty(desktop
),
378 strempty(seat
), vtnr
, strempty(tty
), strempty(display
),
379 yes_no(remote
), strempty(remote_user
), strempty(remote_host
));
381 r
= sd_bus_call_method(bus
,
382 "org.freedesktop.login1",
383 "/org/freedesktop/login1",
384 "org.freedesktop.login1.Manager",
388 "uusssssussbssa(sv)",
389 (uint32_t) pw
->pw_uid
,
404 if (sd_bus_error_has_name(&error
, BUS_ERROR_SESSION_BUSY
)) {
405 pam_syslog(handle
, LOG_DEBUG
, "Cannot create session: %s", bus_error_message(&error
, r
));
408 pam_syslog(handle
, LOG_ERR
, "Failed to create session: %s", bus_error_message(&error
, r
));
409 return PAM_SYSTEM_ERR
;
413 r
= sd_bus_message_read(reply
,
424 pam_syslog(handle
, LOG_ERR
, "Failed to parse message: %s", strerror(-r
));
425 return PAM_SESSION_ERR
;
429 pam_syslog(handle
, LOG_DEBUG
, "Reply from logind: "
430 "id=%s object_path=%s runtime_path=%s session_fd=%d seat=%s vtnr=%u original_uid=%u",
431 id
, object_path
, runtime_path
, session_fd
, seat
, vtnr
, original_uid
);
433 r
= pam_misc_setenv(handle
, "XDG_SESSION_ID", id
, 0);
434 if (r
!= PAM_SUCCESS
) {
435 pam_syslog(handle
, LOG_ERR
, "Failed to set session id.");
439 if (original_uid
== pw
->pw_uid
) {
440 /* Don't set $XDG_RUNTIME_DIR if the user we now
441 * authenticated for does not match the original user
442 * of the session. We do this in order not to result
443 * in privileged apps clobbering the runtime directory
446 r
= pam_misc_setenv(handle
, "XDG_RUNTIME_DIR", runtime_path
, 0);
447 if (r
!= PAM_SUCCESS
) {
448 pam_syslog(handle
, LOG_ERR
, "Failed to set runtime dir.");
452 r
= export_legacy_dbus_address(handle
, pw
->pw_uid
, runtime_path
);
453 if (r
!= PAM_SUCCESS
)
457 if (!isempty(seat
)) {
458 r
= pam_misc_setenv(handle
, "XDG_SEAT", seat
, 0);
459 if (r
!= PAM_SUCCESS
) {
460 pam_syslog(handle
, LOG_ERR
, "Failed to set seat.");
466 char buf
[DECIMAL_STR_MAX(vtnr
)];
467 sprintf(buf
, "%u", vtnr
);
469 r
= pam_misc_setenv(handle
, "XDG_VTNR", buf
, 0);
470 if (r
!= PAM_SUCCESS
) {
471 pam_syslog(handle
, LOG_ERR
, "Failed to set virtual terminal number.");
476 r
= pam_set_data(handle
, "systemd.existing", INT_TO_PTR(!!existing
), NULL
);
477 if (r
!= PAM_SUCCESS
) {
478 pam_syslog(handle
, LOG_ERR
, "Failed to install existing flag.");
482 if (session_fd
>= 0) {
483 session_fd
= fcntl(session_fd
, F_DUPFD_CLOEXEC
, 3);
484 if (session_fd
< 0) {
485 pam_syslog(handle
, LOG_ERR
, "Failed to dup session fd: %m");
486 return PAM_SESSION_ERR
;
489 r
= pam_set_data(handle
, "systemd.session-fd", FD_TO_PTR(session_fd
), NULL
);
490 if (r
!= PAM_SUCCESS
) {
491 pam_syslog(handle
, LOG_ERR
, "Failed to install session fd.");
492 safe_close(session_fd
);
500 _public_ PAM_EXTERN
int pam_sm_close_session(
501 pam_handle_t
*handle
,
503 int argc
, const char **argv
) {
505 _cleanup_(sd_bus_error_free
) sd_bus_error error
= SD_BUS_ERROR_NULL
;
506 _cleanup_(sd_bus_flush_close_unrefp
) sd_bus
*bus
= NULL
;
507 const void *existing
= NULL
;
513 /* Only release session if it wasn't pre-existing when we
514 * tried to create it */
515 pam_get_data(handle
, "systemd.existing", &existing
);
517 id
= pam_getenv(handle
, "XDG_SESSION_ID");
518 if (id
&& !existing
) {
520 /* Before we go and close the FIFO we need to tell
521 * logind that this is a clean session shutdown, so
522 * that it doesn't just go and slaughter us
523 * immediately after closing the fd */
525 r
= sd_bus_open_system(&bus
);
527 pam_syslog(handle
, LOG_ERR
, "Failed to connect to system bus: %s", strerror(-r
));
528 return PAM_SESSION_ERR
;
531 r
= sd_bus_call_method(bus
,
532 "org.freedesktop.login1",
533 "/org/freedesktop/login1",
534 "org.freedesktop.login1.Manager",
541 pam_syslog(handle
, LOG_ERR
, "Failed to release session: %s", bus_error_message(&error
, r
));
542 return PAM_SESSION_ERR
;
546 /* Note that we are knowingly leaking the FIFO fd here. This
547 * way, logind can watch us die. If we closed it here it would
548 * not have any clue when that is completed. Given that one
549 * cannot really have multiple PAM sessions open from the same
550 * process this means we will leak one FD at max. */