1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 This file is part of systemd.
5 Copyright 2010 Lennart Poettering
12 #include <security/_pam_macros.h>
13 #include <security/pam_ext.h>
14 #include <security/pam_misc.h>
15 #include <security/pam_modules.h>
16 #include <security/pam_modutil.h>
19 #include "alloc-util.h"
20 #include "audit-util.h"
21 #include "bus-common-errors.h"
22 #include "bus-error.h"
27 #include "format-util.h"
28 #include "hostname-util.h"
29 #include "login-util.h"
31 #include "parse-util.h"
32 #include "process-util.h"
33 #include "socket-util.h"
35 #include "terminal-util.h"
37 #include "path-util.h"
38 #include "cgroup-util.h"
40 static int parse_argv(
42 int argc
, const char **argv
,
50 assert(argc
== 0 || argv
);
52 for (i
= 0; i
< (unsigned) argc
; i
++) {
53 if (startswith(argv
[i
], "class=")) {
57 } else if (startswith(argv
[i
], "type=")) {
61 } else if (streq(argv
[i
], "debug")) {
65 } else if (startswith(argv
[i
], "debug=")) {
68 k
= parse_boolean(argv
[i
] + 6);
70 pam_syslog(handle
, LOG_WARNING
, "Failed to parse debug= argument, ignoring.");
75 pam_syslog(handle
, LOG_WARNING
, "Unknown parameter '%s', ignoring", argv
[i
]);
81 static int get_user_data(
83 const char **ret_username
,
84 struct passwd
**ret_pw
) {
86 const char *username
= NULL
;
87 struct passwd
*pw
= NULL
;
94 r
= pam_get_user(handle
, &username
, NULL
);
95 if (r
!= PAM_SUCCESS
) {
96 pam_syslog(handle
, LOG_ERR
, "Failed to get user name.");
100 if (isempty(username
)) {
101 pam_syslog(handle
, LOG_ERR
, "User name not valid.");
105 pw
= pam_modutil_getpwnam(handle
, username
);
107 pam_syslog(handle
, LOG_ERR
, "Failed to get user data.");
108 return PAM_USER_UNKNOWN
;
112 *ret_username
= username
;
117 static int get_seat_from_display(const char *display
, const char **seat
, uint32_t *vtnr
) {
118 union sockaddr_union sa
= {
119 .un
.sun_family
= AF_UNIX
,
121 _cleanup_free_
char *p
= NULL
, *tty
= NULL
;
122 _cleanup_close_
int fd
= -1;
129 /* We deduce the X11 socket from the display name, then use
130 * SO_PEERCRED to determine the X11 server process, ask for
131 * the controlling tty of that and if it's a VC then we know
132 * the seat and the virtual terminal. Sounds ugly, is only
135 r
= socket_from_display(display
, &p
);
138 strncpy(sa
.un
.sun_path
, p
, sizeof(sa
.un
.sun_path
)-1);
140 fd
= socket(AF_UNIX
, SOCK_STREAM
|SOCK_CLOEXEC
, 0);
144 if (connect(fd
, &sa
.sa
, SOCKADDR_UN_LEN(sa
.un
)) < 0)
147 r
= getpeercred(fd
, &ucred
);
151 r
= get_ctty(ucred
.pid
, NULL
, &tty
);
155 v
= vtnr_from_tty(tty
);
163 *vtnr
= (uint32_t) v
;
168 static int export_legacy_dbus_address(
169 pam_handle_t
*handle
,
171 const char *runtime
) {
173 _cleanup_free_
char *s
= NULL
;
176 /* FIXME: We *really* should move the access() check into the
177 * daemons that spawn dbus-daemon, instead of forcing
178 * DBUS_SESSION_BUS_ADDRESS= here. */
180 s
= strjoin(runtime
, "/bus");
184 if (access(s
, F_OK
) < 0)
188 if (asprintf(&s
, DEFAULT_USER_BUS_ADDRESS_FMT
, runtime
) < 0)
191 r
= pam_misc_setenv(handle
, "DBUS_SESSION_BUS_ADDRESS", s
, 0);
192 if (r
!= PAM_SUCCESS
)
198 pam_syslog(handle
, LOG_ERR
, "Failed to set bus variable.");
202 static int append_session_memory_max(pam_handle_t
*handle
, sd_bus_message
*m
, const char *limit
) {
209 if (streq(limit
, "infinity")) {
210 r
= sd_bus_message_append(m
, "(sv)", "MemoryMax", "t", (uint64_t)-1);
212 pam_syslog(handle
, LOG_ERR
, "Failed to append to bus message: %s", strerror(-r
));
216 r
= parse_percent(limit
);
218 r
= sd_bus_message_append(m
, "(sv)", "MemoryMaxScale", "u", (uint32_t) (((uint64_t) UINT32_MAX
* r
) / 100U));
220 pam_syslog(handle
, LOG_ERR
, "Failed to append to bus message: %s", strerror(-r
));
224 r
= parse_size(limit
, 1024, &val
);
226 r
= sd_bus_message_append(m
, "(sv)", "MemoryMax", "t", val
);
228 pam_syslog(handle
, LOG_ERR
, "Failed to append to bus message: %s", strerror(-r
));
232 pam_syslog(handle
, LOG_WARNING
, "Failed to parse systemd.limit: %s, ignoring.", limit
);
239 static int append_session_tasks_max(pam_handle_t
*handle
, sd_bus_message
*m
, const char *limit
)
244 /* No need to parse "infinity" here, it will be set unconditionally later in manager_start_scope() */
245 if (isempty(limit
) || streq(limit
, "infinity"))
248 r
= safe_atou64(limit
, &val
);
250 r
= sd_bus_message_append(m
, "(sv)", "TasksMax", "t", val
);
252 pam_syslog(handle
, LOG_ERR
, "Failed to append to bus message: %s", strerror(-r
));
256 pam_syslog(handle
, LOG_WARNING
, "Failed to parse systemd.limit: %s, ignoring.", limit
);
261 static int append_session_cg_weight(pam_handle_t
*handle
, sd_bus_message
*m
, const char *limit
, const char *field
) {
265 if (!isempty(limit
)) {
266 r
= cg_weight_parse(limit
, &val
);
268 r
= sd_bus_message_append(m
, "(sv)", field
, "t", val
);
270 pam_syslog(handle
, LOG_ERR
, "Failed to append to bus message: %s", strerror(-r
));
273 } else if (streq(field
, "CPUWeight"))
274 pam_syslog(handle
, LOG_WARNING
, "Failed to parse systemd.cpu_weight: %s, ignoring.", limit
);
276 pam_syslog(handle
, LOG_WARNING
, "Failed to parse systemd.io_weight: %s, ignoring.", limit
);
282 _public_ PAM_EXTERN
int pam_sm_open_session(
283 pam_handle_t
*handle
,
285 int argc
, const char **argv
) {
287 _cleanup_(sd_bus_error_free
) sd_bus_error error
= SD_BUS_ERROR_NULL
;
288 _cleanup_(sd_bus_message_unrefp
) sd_bus_message
*m
= NULL
, *reply
= NULL
;
290 *username
, *id
, *object_path
, *runtime_path
,
292 *tty
= NULL
, *display
= NULL
,
293 *remote_user
= NULL
, *remote_host
= NULL
,
295 *type
= NULL
, *class = NULL
,
296 *class_pam
= NULL
, *type_pam
= NULL
, *cvtnr
= NULL
, *desktop
= NULL
,
297 *memory_max
= NULL
, *tasks_max
= NULL
, *cpu_weight
= NULL
, *io_weight
= NULL
;
298 _cleanup_(sd_bus_flush_close_unrefp
) sd_bus
*bus
= NULL
;
299 int session_fd
= -1, existing
, r
;
300 bool debug
= false, remote
;
307 /* Make this a NOP on non-logind systems */
308 if (!logind_running())
311 if (parse_argv(handle
,
316 return PAM_SESSION_ERR
;
319 pam_syslog(handle
, LOG_DEBUG
, "pam-systemd initializing");
321 r
= get_user_data(handle
, &username
, &pw
);
322 if (r
!= PAM_SUCCESS
) {
323 pam_syslog(handle
, LOG_ERR
, "Failed to get user data.");
327 /* Make sure we don't enter a loop by talking to
328 * systemd-logind when it is actually waiting for the
329 * background to finish start-up. If the service is
330 * "systemd-user" we simply set XDG_RUNTIME_DIR and
333 pam_get_item(handle
, PAM_SERVICE
, (const void**) &service
);
334 if (streq_ptr(service
, "systemd-user")) {
335 _cleanup_free_
char *rt
= NULL
;
337 if (asprintf(&rt
, "/run/user/"UID_FMT
, pw
->pw_uid
) < 0)
340 r
= pam_misc_setenv(handle
, "XDG_RUNTIME_DIR", rt
, 0);
341 if (r
!= PAM_SUCCESS
) {
342 pam_syslog(handle
, LOG_ERR
, "Failed to set runtime dir.");
346 r
= export_legacy_dbus_address(handle
, pw
->pw_uid
, rt
);
347 if (r
!= PAM_SUCCESS
)
353 /* Otherwise, we ask logind to create a session for us */
355 pam_get_item(handle
, PAM_XDISPLAY
, (const void**) &display
);
356 pam_get_item(handle
, PAM_TTY
, (const void**) &tty
);
357 pam_get_item(handle
, PAM_RUSER
, (const void**) &remote_user
);
358 pam_get_item(handle
, PAM_RHOST
, (const void**) &remote_host
);
360 seat
= pam_getenv(handle
, "XDG_SEAT");
362 seat
= getenv("XDG_SEAT");
364 cvtnr
= pam_getenv(handle
, "XDG_VTNR");
366 cvtnr
= getenv("XDG_VTNR");
368 type
= pam_getenv(handle
, "XDG_SESSION_TYPE");
370 type
= getenv("XDG_SESSION_TYPE");
374 class = pam_getenv(handle
, "XDG_SESSION_CLASS");
376 class = getenv("XDG_SESSION_CLASS");
380 desktop
= pam_getenv(handle
, "XDG_SESSION_DESKTOP");
381 if (isempty(desktop
))
382 desktop
= getenv("XDG_SESSION_DESKTOP");
386 if (strchr(tty
, ':')) {
387 /* A tty with a colon is usually an X11 display,
388 * placed there to show up in utmp. We rearrange
389 * things and don't pretend that an X display was a
392 if (isempty(display
))
395 } else if (streq(tty
, "cron")) {
396 /* cron has been setting PAM_TTY to "cron" for a very
397 * long time and it probably shouldn't stop doing that
398 * for compatibility reasons. */
399 type
= "unspecified";
400 class = "background";
402 } else if (streq(tty
, "ssh")) {
403 /* ssh has been setting PAM_TTY to "ssh" for a very
404 * long time and probably shouldn't stop doing that
405 * for compatibility reasons. */
410 /* Chop off leading /dev prefix that some clients specify, but others do not. */
411 tty
= skip_dev_prefix(tty
);
413 /* If this fails vtnr will be 0, that's intended */
415 (void) safe_atou32(cvtnr
, &vtnr
);
417 if (!isempty(display
) && !vtnr
) {
419 get_seat_from_display(display
, &seat
, &vtnr
);
420 else if (streq(seat
, "seat0"))
421 get_seat_from_display(display
, NULL
, &vtnr
);
424 if (seat
&& !streq(seat
, "seat0") && vtnr
!= 0) {
425 pam_syslog(handle
, LOG_DEBUG
, "Ignoring vtnr %"PRIu32
" for %s which is not seat0", vtnr
, seat
);
430 type
= !isempty(display
) ? "x11" :
431 !isempty(tty
) ? "tty" : "unspecified";
434 class = streq(type
, "unspecified") ? "background" : "user";
436 remote
= !isempty(remote_host
) && !is_localhost(remote_host
);
438 (void) pam_get_data(handle
, "systemd.memory_max", (const void **)&memory_max
);
439 (void) pam_get_data(handle
, "systemd.tasks_max", (const void **)&tasks_max
);
440 (void) pam_get_data(handle
, "systemd.cpu_weight", (const void **)&cpu_weight
);
441 (void) pam_get_data(handle
, "systemd.io_weight", (const void **)&io_weight
);
443 /* Talk to logind over the message bus */
445 r
= sd_bus_open_system(&bus
);
447 pam_syslog(handle
, LOG_ERR
, "Failed to connect to system bus: %s", strerror(-r
));
448 return PAM_SESSION_ERR
;
452 pam_syslog(handle
, LOG_DEBUG
, "Asking logind to create session: "
453 "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",
454 pw
->pw_uid
, getpid_cached(),
456 type
, class, strempty(desktop
),
457 strempty(seat
), vtnr
, strempty(tty
), strempty(display
),
458 yes_no(remote
), strempty(remote_user
), strempty(remote_host
));
459 pam_syslog(handle
, LOG_DEBUG
, "Session limits: "
460 "memory_max=%s tasks_max=%s cpu_weight=%s io_weight=%s",
461 strna(memory_max
), strna(tasks_max
), strna(cpu_weight
), strna(io_weight
));
464 r
= sd_bus_message_new_method_call(
467 "org.freedesktop.login1",
468 "/org/freedesktop/login1",
469 "org.freedesktop.login1.Manager",
472 pam_syslog(handle
, LOG_ERR
, "Failed to create CreateSession method call: %s", strerror(-r
));
473 return PAM_SESSION_ERR
;
476 r
= sd_bus_message_append(m
, "uusssssussbss",
477 (uint32_t) pw
->pw_uid
,
478 (uint32_t) getpid_cached(),
491 pam_syslog(handle
, LOG_ERR
, "Failed to append to bus message: %s", strerror(-r
));
492 return PAM_SESSION_ERR
;
495 r
= sd_bus_message_open_container(m
, 'a', "(sv)");
497 pam_syslog(handle
, LOG_ERR
, "Failed to open message container: %s", strerror(-r
));
498 return PAM_SYSTEM_ERR
;
501 r
= append_session_memory_max(handle
, m
, memory_max
);
503 return PAM_SESSION_ERR
;
505 r
= append_session_tasks_max(handle
, m
, tasks_max
);
507 return PAM_SESSION_ERR
;
509 r
= append_session_cg_weight(handle
, m
, cpu_weight
, "CPUWeight");
511 return PAM_SESSION_ERR
;
513 r
= append_session_cg_weight(handle
, m
, io_weight
, "IOWeight");
515 return PAM_SESSION_ERR
;
517 r
= sd_bus_message_close_container(m
);
519 pam_syslog(handle
, LOG_ERR
, "Failed to close message container: %s", strerror(-r
));
520 return PAM_SYSTEM_ERR
;
523 r
= sd_bus_call(bus
, m
, 0, &error
, &reply
);
525 if (sd_bus_error_has_name(&error
, BUS_ERROR_SESSION_BUSY
)) {
526 pam_syslog(handle
, LOG_DEBUG
, "Cannot create session: %s", bus_error_message(&error
, r
));
529 pam_syslog(handle
, LOG_ERR
, "Failed to create session: %s", bus_error_message(&error
, r
));
530 return PAM_SYSTEM_ERR
;
534 r
= sd_bus_message_read(reply
,
545 pam_syslog(handle
, LOG_ERR
, "Failed to parse message: %s", strerror(-r
));
546 return PAM_SESSION_ERR
;
550 pam_syslog(handle
, LOG_DEBUG
, "Reply from logind: "
551 "id=%s object_path=%s runtime_path=%s session_fd=%d seat=%s vtnr=%u original_uid=%u",
552 id
, object_path
, runtime_path
, session_fd
, seat
, vtnr
, original_uid
);
554 r
= pam_misc_setenv(handle
, "XDG_SESSION_ID", id
, 0);
555 if (r
!= PAM_SUCCESS
) {
556 pam_syslog(handle
, LOG_ERR
, "Failed to set session id.");
560 if (original_uid
== pw
->pw_uid
) {
561 /* Don't set $XDG_RUNTIME_DIR if the user we now
562 * authenticated for does not match the original user
563 * of the session. We do this in order not to result
564 * in privileged apps clobbering the runtime directory
567 r
= pam_misc_setenv(handle
, "XDG_RUNTIME_DIR", runtime_path
, 0);
568 if (r
!= PAM_SUCCESS
) {
569 pam_syslog(handle
, LOG_ERR
, "Failed to set runtime dir.");
573 r
= export_legacy_dbus_address(handle
, pw
->pw_uid
, runtime_path
);
574 if (r
!= PAM_SUCCESS
)
578 if (!isempty(seat
)) {
579 r
= pam_misc_setenv(handle
, "XDG_SEAT", seat
, 0);
580 if (r
!= PAM_SUCCESS
) {
581 pam_syslog(handle
, LOG_ERR
, "Failed to set seat.");
587 char buf
[DECIMAL_STR_MAX(vtnr
)];
588 sprintf(buf
, "%u", vtnr
);
590 r
= pam_misc_setenv(handle
, "XDG_VTNR", buf
, 0);
591 if (r
!= PAM_SUCCESS
) {
592 pam_syslog(handle
, LOG_ERR
, "Failed to set virtual terminal number.");
597 r
= pam_set_data(handle
, "systemd.existing", INT_TO_PTR(!!existing
), NULL
);
598 if (r
!= PAM_SUCCESS
) {
599 pam_syslog(handle
, LOG_ERR
, "Failed to install existing flag.");
603 if (session_fd
>= 0) {
604 session_fd
= fcntl(session_fd
, F_DUPFD_CLOEXEC
, 3);
605 if (session_fd
< 0) {
606 pam_syslog(handle
, LOG_ERR
, "Failed to dup session fd: %m");
607 return PAM_SESSION_ERR
;
610 r
= pam_set_data(handle
, "systemd.session-fd", FD_TO_PTR(session_fd
), NULL
);
611 if (r
!= PAM_SUCCESS
) {
612 pam_syslog(handle
, LOG_ERR
, "Failed to install session fd.");
613 safe_close(session_fd
);
621 _public_ PAM_EXTERN
int pam_sm_close_session(
622 pam_handle_t
*handle
,
624 int argc
, const char **argv
) {
626 _cleanup_(sd_bus_error_free
) sd_bus_error error
= SD_BUS_ERROR_NULL
;
627 _cleanup_(sd_bus_flush_close_unrefp
) sd_bus
*bus
= NULL
;
628 const void *existing
= NULL
;
634 /* Only release session if it wasn't pre-existing when we
635 * tried to create it */
636 pam_get_data(handle
, "systemd.existing", &existing
);
638 id
= pam_getenv(handle
, "XDG_SESSION_ID");
639 if (id
&& !existing
) {
641 /* Before we go and close the FIFO we need to tell
642 * logind that this is a clean session shutdown, so
643 * that it doesn't just go and slaughter us
644 * immediately after closing the fd */
646 r
= sd_bus_open_system(&bus
);
648 pam_syslog(handle
, LOG_ERR
, "Failed to connect to system bus: %s", strerror(-r
));
649 return PAM_SESSION_ERR
;
652 r
= sd_bus_call_method(bus
,
653 "org.freedesktop.login1",
654 "/org/freedesktop/login1",
655 "org.freedesktop.login1.Manager",
662 pam_syslog(handle
, LOG_ERR
, "Failed to release session: %s", bus_error_message(&error
, r
));
663 return PAM_SESSION_ERR
;
667 /* Note that we are knowingly leaking the FIFO fd here. This
668 * way, logind can watch us die. If we closed it here it would
669 * not have any clue when that is completed. Given that one
670 * cannot really have multiple PAM sessions open from the same
671 * process this means we will leak one FD at max. */