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 "format-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");
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 #if 0 /// with elogind, it is always a "logind system".
236 /* Make this a NOP on non-logind systems */
237 if (!logind_running())
241 if (parse_argv(handle,
246 return PAM_SESSION_ERR;
249 #if 0 /// This is pam-elogind, not pam-systemd
250 pam_syslog(handle, LOG_DEBUG, "pam-systemd initializing");
252 pam_syslog(handle, LOG_DEBUG, "pam-elogind initializing");
255 r = get_user_data(handle, &username, &pw);
256 if (r != PAM_SUCCESS) {
257 pam_syslog(handle, LOG_ERR, "Failed to get user data.");
261 /* Make sure we don't enter a loop by talking to
262 * systemd-logind when it is actually waiting for the
263 * background to finish start-up. If the service is
264 * "systemd-user" we simply set XDG_RUNTIME_DIR and
267 pam_get_item(handle, PAM_SERVICE, (const void**) &service);
268 #if 0 /// Actually it is elogind-user with elogind.
269 if (streq_ptr(service, "systemd-user")) {
271 if (streq_ptr(service, "elogind-user")) {
273 _cleanup_free_ char *rt = NULL;
275 if (asprintf(&rt, "/run/user/"UID_FMT, pw->pw_uid) < 0)
278 r = pam_misc_setenv(handle, "XDG_RUNTIME_DIR", rt, 0);
279 if (r != PAM_SUCCESS) {
280 pam_syslog(handle, LOG_ERR, "Failed to set runtime dir.");
284 r = export_legacy_dbus_address(handle, pw->pw_uid, rt);
285 if (r != PAM_SUCCESS)
291 /* Otherwise, we ask logind to create a session for us */
293 pam_get_item(handle, PAM_XDISPLAY, (const void**) &display);
294 pam_get_item(handle, PAM_TTY, (const void**) &tty);
295 pam_get_item(handle, PAM_RUSER, (const void**) &remote_user);
296 pam_get_item(handle, PAM_RHOST, (const void**) &remote_host);
298 seat = pam_getenv(handle, "XDG_SEAT");
300 seat = getenv("XDG_SEAT");
302 cvtnr = pam_getenv(handle, "XDG_VTNR");
304 cvtnr = getenv("XDG_VTNR");
306 type = pam_getenv(handle, "XDG_SESSION_TYPE");
308 type = getenv("XDG_SESSION_TYPE");
312 class = pam_getenv(handle, "XDG_SESSION_CLASS");
314 class = getenv("XDG_SESSION_CLASS");
318 desktop = pam_getenv(handle, "XDG_SESSION_DESKTOP");
319 if (isempty(desktop))
320 desktop = getenv("XDG_SESSION_DESKTOP");
324 if (strchr(tty, ':')) {
325 /* A tty with a colon is usually an X11 display,
326 * placed there to show up in utmp. We rearrange
327 * things and don't pretend that an X display was a
330 if (isempty(display))
333 } else if (streq(tty, "cron")) {
334 /* cron has been setting PAM_TTY to "cron" for a very
335 * long time and it probably shouldn't stop doing that
336 * for compatibility reasons. */
337 type = "unspecified";
338 class = "background";
340 } else if (streq(tty, "ssh")) {
341 /* ssh has been setting PAM_TTY to "ssh" for a very
342 * long time and probably shouldn't stop doing that
343 * for compatibility reasons. */
349 /* If this fails vtnr will be 0, that's intended */
351 (void) safe_atou32(cvtnr, &vtnr);
353 if (!isempty(display) && !vtnr) {
355 get_seat_from_display(display, &seat, &vtnr);
356 else if (streq(seat, "seat0"))
357 get_seat_from_display(display, NULL, &vtnr);
360 if (seat && !streq(seat, "seat0") && vtnr != 0) {
361 pam_syslog(handle, LOG_DEBUG, "Ignoring vtnr %"PRIu32" for %s which is not seat0", vtnr, seat);
366 type = !isempty(display) ? "x11" :
367 !isempty(tty) ? "tty" : "unspecified";
370 class = streq(type, "unspecified") ? "background" : "user";
372 remote = !isempty(remote_host) && !is_localhost(remote_host);
374 /* Talk to logind over the message bus */
376 r = sd_bus_open_system(&bus);
378 pam_syslog(handle, LOG_ERR, "Failed to connect to system bus: %s", strerror(-r));
379 return PAM_SESSION_ERR;
383 pam_syslog(handle, LOG_DEBUG, "Asking logind to create session: "
384 "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",
385 pw->pw_uid, getpid(),
387 type, class, strempty(desktop),
388 strempty(seat), vtnr, strempty(tty), strempty(display),
389 yes_no(remote), strempty(remote_user), strempty(remote_host));
391 r = sd_bus_call_method(bus,
392 "org.freedesktop.login1",
393 "/org/freedesktop/login1",
394 "org.freedesktop.login1.Manager",
398 "uusssssussbssa(sv)",
399 (uint32_t) pw->pw_uid,
414 if (sd_bus_error_has_name(&error, BUS_ERROR_SESSION_BUSY)) {
415 pam_syslog(handle, LOG_DEBUG, "Cannot create session: %s", bus_error_message(&error, r));
418 pam_syslog(handle, LOG_ERR, "Failed to create session: %s", bus_error_message(&error, r));
419 return PAM_SYSTEM_ERR;
423 r = sd_bus_message_read(reply,
434 pam_syslog(handle, LOG_ERR, "Failed to parse message: %s", strerror(-r));
435 return PAM_SESSION_ERR;
439 pam_syslog(handle, LOG_DEBUG, "Reply from logind: "
440 "id=%s object_path=%s runtime_path=%s session_fd=%d seat=%s vtnr=%u original_uid=%u",
441 id, object_path, runtime_path, session_fd, seat, vtnr, original_uid);
443 r = pam_misc_setenv(handle, "XDG_SESSION_ID", id, 0);
444 if (r != PAM_SUCCESS) {
445 pam_syslog(handle, LOG_ERR, "Failed to set session id.");
449 if (original_uid == pw->pw_uid) {
450 /* Don't set $XDG_RUNTIME_DIR if the user we now
451 * authenticated for does not match the original user
452 * of the session. We do this in order not to result
453 * in privileged apps clobbering the runtime directory
456 r = pam_misc_setenv(handle, "XDG_RUNTIME_DIR", runtime_path, 0);
457 if (r != PAM_SUCCESS) {
458 pam_syslog(handle, LOG_ERR, "Failed to set runtime dir.");
462 r = export_legacy_dbus_address(handle, pw->pw_uid, runtime_path);
463 if (r != PAM_SUCCESS)
467 if (!isempty(seat)) {
468 r = pam_misc_setenv(handle, "XDG_SEAT", seat, 0);
469 if (r != PAM_SUCCESS) {
470 pam_syslog(handle, LOG_ERR, "Failed to set seat.");
476 char buf[DECIMAL_STR_MAX(vtnr)];
477 sprintf(buf, "%u", vtnr);
479 r = pam_misc_setenv(handle, "XDG_VTNR", buf, 0);
480 if (r != PAM_SUCCESS) {
481 pam_syslog(handle, LOG_ERR, "Failed to set virtual terminal number.");
486 r = pam_set_data(handle, "systemd.existing", INT_TO_PTR(!!existing), NULL);
487 if (r != PAM_SUCCESS) {
488 pam_syslog(handle, LOG_ERR, "Failed to install existing flag.");
492 if (session_fd >= 0) {
493 session_fd = fcntl(session_fd, F_DUPFD_CLOEXEC, 3);
494 if (session_fd < 0) {
495 pam_syslog(handle, LOG_ERR, "Failed to dup session fd: %m");
496 return PAM_SESSION_ERR;
499 r = pam_set_data(handle, "systemd.session-fd", FD_TO_PTR(session_fd), NULL);
500 if (r != PAM_SUCCESS) {
501 pam_syslog(handle, LOG_ERR, "Failed to install session fd.");
502 safe_close(session_fd);
510 _public_ PAM_EXTERN int pam_sm_close_session(
511 pam_handle_t *handle,
513 int argc, const char **argv) {
515 _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
516 _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
517 const void *existing = NULL;
523 /* Only release session if it wasn't pre-existing when we
524 * tried to create it */
525 pam_get_data(handle, "systemd.existing", &existing);
527 id = pam_getenv(handle, "XDG_SESSION_ID");
528 if (id && !existing) {
530 /* Before we go and close the FIFO we need to tell
531 * logind that this is a clean session shutdown, so
532 * that it doesn't just go and slaughter us
533 * immediately after closing the fd */
535 r = sd_bus_open_system(&bus);
537 pam_syslog(handle, LOG_ERR, "Failed to connect to system bus: %s", strerror(-r));
538 return PAM_SESSION_ERR;
541 r = sd_bus_call_method(bus,
542 "org.freedesktop.login1",
543 "/org/freedesktop/login1",
544 "org.freedesktop.login1.Manager",
551 pam_syslog(handle, LOG_ERR, "Failed to release session: %s", bus_error_message(&error, r));
552 return PAM_SESSION_ERR;
556 /* Note that we are knowingly leaking the FIFO fd here. This
557 * way, logind can watch us die. If we closed it here it would
558 * not have any clue when that is completed. Given that one
559 * cannot really have multiple PAM sessions open from the same
560 * process this means we will leak one FD at max. */