1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2010 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
26 #include <security/_pam_macros.h>
27 #include <security/pam_ext.h>
28 #include <security/pam_misc.h>
29 #include <security/pam_modules.h>
30 #include <security/pam_modutil.h>
33 #include "alloc-util.h"
34 #include "audit-util.h"
35 #include "bus-common-errors.h"
36 #include "bus-error.h"
41 #include "formats-util.h"
42 #include "hostname-util.h"
43 #include "login-util.h"
45 #include "parse-util.h"
46 #include "socket-util.h"
48 #include "terminal-util.h"
51 static int parse_argv(
53 int argc, const char **argv,
61 assert(argc == 0 || argv);
63 for (i = 0; i < (unsigned) argc; i++) {
64 if (startswith(argv[i], "class=")) {
68 } else if (startswith(argv[i], "type=")) {
72 } else if (streq(argv[i], "debug")) {
76 } else if (startswith(argv[i], "debug=")) {
79 k = parse_boolean(argv[i] + 6);
81 pam_syslog(handle, LOG_WARNING, "Failed to parse debug= argument, ignoring.");
86 pam_syslog(handle, LOG_WARNING, "Unknown parameter '%s', ignoring", argv[i]);
92 static int get_user_data(
94 const char **ret_username,
95 struct passwd **ret_pw) {
97 const char *username = NULL;
98 struct passwd *pw = NULL;
102 assert(ret_username);
105 r = pam_get_user(handle, &username, NULL);
106 if (r != PAM_SUCCESS) {
107 pam_syslog(handle, LOG_ERR, "Failed to get user name.");
111 if (isempty(username)) {
112 pam_syslog(handle, LOG_ERR, "User name not valid.");
116 pw = pam_modutil_getpwnam(handle, username);
118 pam_syslog(handle, LOG_ERR, "Failed to get user data.");
119 return PAM_USER_UNKNOWN;
123 *ret_username = username;
128 static int get_seat_from_display(const char *display, const char **seat, uint32_t *vtnr) {
129 union sockaddr_union sa = {
130 .un.sun_family = AF_UNIX,
132 _cleanup_free_ char *p = NULL, *tty = NULL;
133 _cleanup_close_ int fd = -1;
140 /* We deduce the X11 socket from the display name, then use
141 * SO_PEERCRED to determine the X11 server process, ask for
142 * the controlling tty of that and if it's a VC then we know
143 * the seat and the virtual terminal. Sounds ugly, is only
146 r = socket_from_display(display, &p);
149 strncpy(sa.un.sun_path, p, sizeof(sa.un.sun_path)-1);
151 fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0);
155 if (connect(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path)) < 0)
158 r = getpeercred(fd, &ucred);
162 r = get_ctty(ucred.pid, NULL, &tty);
166 v = vtnr_from_tty(tty);
174 *vtnr = (uint32_t) v;
179 static int export_legacy_dbus_address(
180 pam_handle_t *handle,
182 const char *runtime) {
184 _cleanup_free_ char *s = NULL;
187 if (is_kdbus_available()) {
188 if (asprintf(&s, KERNEL_USER_BUS_ADDRESS_FMT ";" UNIX_USER_BUS_ADDRESS_FMT, uid, runtime) < 0)
191 /* FIXME: We *really* should move the access() check into the
192 * daemons that spawn dbus-daemon, instead of forcing
193 * DBUS_SESSION_BUS_ADDRESS= here. */
195 s = strjoin(runtime, "/bus", NULL);
199 if (access(s, F_OK) < 0)
203 if (asprintf(&s, UNIX_USER_BUS_ADDRESS_FMT, runtime) < 0)
207 r = pam_misc_setenv(handle, "DBUS_SESSION_BUS_ADDRESS", s, 0);
208 if (r != PAM_SUCCESS)
214 pam_syslog(handle, LOG_ERR, "Failed to set bus variable.");
218 _public_ PAM_EXTERN int pam_sm_open_session(
219 pam_handle_t *handle,
221 int argc, const char **argv) {
223 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
224 _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
226 *username, *id, *object_path, *runtime_path,
228 *tty = NULL, *display = NULL,
229 *remote_user = NULL, *remote_host = NULL,
231 *type = NULL, *class = NULL,
232 *class_pam = NULL, *type_pam = NULL, *cvtnr = NULL, *desktop = NULL;
233 _cleanup_bus_flush_close_unref_ sd_bus *bus = NULL;
234 int session_fd = -1, existing, r;
235 bool debug = false, remote;
242 /* Make this a NOP on non-logind systems */
243 if (!logind_running())
246 if (parse_argv(handle,
251 return PAM_SESSION_ERR;
254 pam_syslog(handle, LOG_DEBUG, "pam-systemd initializing");
256 r = get_user_data(handle, &username, &pw);
257 if (r != PAM_SUCCESS) {
258 pam_syslog(handle, LOG_ERR, "Failed to get user data.");
262 /* Make sure we don't enter a loop by talking to
263 * systemd-logind when it is actually waiting for the
264 * background to finish start-up. If the service is
265 * "systemd-user" we simply set XDG_RUNTIME_DIR and
268 pam_get_item(handle, PAM_SERVICE, (const void**) &service);
269 if (streq_ptr(service, "systemd-user")) {
270 _cleanup_free_ char *rt = NULL;
272 if (asprintf(&rt, "/run/user/"UID_FMT, pw->pw_uid) < 0)
275 r = pam_misc_setenv(handle, "XDG_RUNTIME_DIR", rt, 0);
276 if (r != PAM_SUCCESS) {
277 pam_syslog(handle, LOG_ERR, "Failed to set runtime dir.");
281 r = export_legacy_dbus_address(handle, pw->pw_uid, rt);
282 if (r != PAM_SUCCESS)
288 /* Otherwise, we ask logind to create a session for us */
290 pam_get_item(handle, PAM_XDISPLAY, (const void**) &display);
291 pam_get_item(handle, PAM_TTY, (const void**) &tty);
292 pam_get_item(handle, PAM_RUSER, (const void**) &remote_user);
293 pam_get_item(handle, PAM_RHOST, (const void**) &remote_host);
295 seat = pam_getenv(handle, "XDG_SEAT");
297 seat = getenv("XDG_SEAT");
299 cvtnr = pam_getenv(handle, "XDG_VTNR");
301 cvtnr = getenv("XDG_VTNR");
303 type = pam_getenv(handle, "XDG_SESSION_TYPE");
305 type = getenv("XDG_SESSION_TYPE");
309 class = pam_getenv(handle, "XDG_SESSION_CLASS");
311 class = getenv("XDG_SESSION_CLASS");
315 desktop = pam_getenv(handle, "XDG_SESSION_DESKTOP");
316 if (isempty(desktop))
317 desktop = getenv("XDG_SESSION_DESKTOP");
321 if (strchr(tty, ':')) {
322 /* A tty with a colon is usually an X11 display,
323 * placed there to show up in utmp. We rearrange
324 * things and don't pretend that an X display was a
327 if (isempty(display))
330 } else if (streq(tty, "cron")) {
331 /* cron has been setting PAM_TTY to "cron" for a very
332 * long time and it probably shouldn't stop doing that
333 * for compatibility reasons. */
334 type = "unspecified";
335 class = "background";
337 } else if (streq(tty, "ssh")) {
338 /* ssh has been setting PAM_TTY to "ssh" for a very
339 * long time and probably shouldn't stop doing that
340 * for compatibility reasons. */
346 /* If this fails vtnr will be 0, that's intended */
348 (void) safe_atou32(cvtnr, &vtnr);
350 if (!isempty(display) && !vtnr) {
352 get_seat_from_display(display, &seat, &vtnr);
353 else if (streq(seat, "seat0"))
354 get_seat_from_display(display, NULL, &vtnr);
357 if (seat && !streq(seat, "seat0") && vtnr != 0) {
358 pam_syslog(handle, LOG_DEBUG, "Ignoring vtnr %"PRIu32" for %s which is not seat0", vtnr, seat);
363 type = !isempty(display) ? "x11" :
364 !isempty(tty) ? "tty" : "unspecified";
367 class = streq(type, "unspecified") ? "background" : "user";
369 remote = !isempty(remote_host) && !is_localhost(remote_host);
371 /* Talk to logind over the message bus */
373 r = sd_bus_open_system(&bus);
375 pam_syslog(handle, LOG_ERR, "Failed to connect to system bus: %s", strerror(-r));
376 return PAM_SESSION_ERR;
380 pam_syslog(handle, LOG_DEBUG, "Asking logind to create session: "
381 "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",
382 pw->pw_uid, getpid(),
384 type, class, strempty(desktop),
385 strempty(seat), vtnr, strempty(tty), strempty(display),
386 yes_no(remote), strempty(remote_user), strempty(remote_host));
388 r = sd_bus_call_method(bus,
389 "org.freedesktop.login1",
390 "/org/freedesktop/login1",
391 "org.freedesktop.login1.Manager",
395 "uusssssussbssa(sv)",
396 (uint32_t) pw->pw_uid,
411 if (sd_bus_error_has_name(&error, BUS_ERROR_SESSION_BUSY)) {
412 pam_syslog(handle, LOG_DEBUG, "Cannot create session: %s", bus_error_message(&error, r));
415 pam_syslog(handle, LOG_ERR, "Failed to create session: %s", bus_error_message(&error, r));
416 return PAM_SYSTEM_ERR;
420 r = sd_bus_message_read(reply,
431 pam_syslog(handle, LOG_ERR, "Failed to parse message: %s", strerror(-r));
432 return PAM_SESSION_ERR;
436 pam_syslog(handle, LOG_DEBUG, "Reply from logind: "
437 "id=%s object_path=%s runtime_path=%s session_fd=%d seat=%s vtnr=%u original_uid=%u",
438 id, object_path, runtime_path, session_fd, seat, vtnr, original_uid);
440 r = pam_misc_setenv(handle, "XDG_SESSION_ID", id, 0);
441 if (r != PAM_SUCCESS) {
442 pam_syslog(handle, LOG_ERR, "Failed to set session id.");
446 if (original_uid == pw->pw_uid) {
447 /* Don't set $XDG_RUNTIME_DIR if the user we now
448 * authenticated for does not match the original user
449 * of the session. We do this in order not to result
450 * in privileged apps clobbering the runtime directory
453 r = pam_misc_setenv(handle, "XDG_RUNTIME_DIR", runtime_path, 0);
454 if (r != PAM_SUCCESS) {
455 pam_syslog(handle, LOG_ERR, "Failed to set runtime dir.");
459 r = export_legacy_dbus_address(handle, pw->pw_uid, runtime_path);
460 if (r != PAM_SUCCESS)
464 if (!isempty(seat)) {
465 r = pam_misc_setenv(handle, "XDG_SEAT", seat, 0);
466 if (r != PAM_SUCCESS) {
467 pam_syslog(handle, LOG_ERR, "Failed to set seat.");
473 char buf[DECIMAL_STR_MAX(vtnr)];
474 sprintf(buf, "%u", vtnr);
476 r = pam_misc_setenv(handle, "XDG_VTNR", buf, 0);
477 if (r != PAM_SUCCESS) {
478 pam_syslog(handle, LOG_ERR, "Failed to set virtual terminal number.");
483 r = pam_set_data(handle, "systemd.existing", INT_TO_PTR(!!existing), NULL);
484 if (r != PAM_SUCCESS) {
485 pam_syslog(handle, LOG_ERR, "Failed to install existing flag.");
489 if (session_fd >= 0) {
490 session_fd = fcntl(session_fd, F_DUPFD_CLOEXEC, 3);
491 if (session_fd < 0) {
492 pam_syslog(handle, LOG_ERR, "Failed to dup session fd: %m");
493 return PAM_SESSION_ERR;
496 r = pam_set_data(handle, "systemd.session-fd", FD_TO_PTR(session_fd), NULL);
497 if (r != PAM_SUCCESS) {
498 pam_syslog(handle, LOG_ERR, "Failed to install session fd.");
499 safe_close(session_fd);
507 _public_ PAM_EXTERN int pam_sm_close_session(
508 pam_handle_t *handle,
510 int argc, const char **argv) {
512 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
513 _cleanup_bus_flush_close_unref_ sd_bus *bus = NULL;
514 const void *existing = NULL;
520 /* Only release session if it wasn't pre-existing when we
521 * tried to create it */
522 pam_get_data(handle, "systemd.existing", &existing);
524 id = pam_getenv(handle, "XDG_SESSION_ID");
525 if (id && !existing) {
527 /* Before we go and close the FIFO we need to tell
528 * logind that this is a clean session shutdown, so
529 * that it doesn't just go and slaughter us
530 * immediately after closing the fd */
532 r = sd_bus_open_system(&bus);
534 pam_syslog(handle, LOG_ERR, "Failed to connect to system bus: %s", strerror(-r));
535 return PAM_SESSION_ERR;
538 r = sd_bus_call_method(bus,
539 "org.freedesktop.login1",
540 "/org/freedesktop/login1",
541 "org.freedesktop.login1.Manager",
548 pam_syslog(handle, LOG_ERR, "Failed to release session: %s", bus_error_message(&error, r));
549 return PAM_SESSION_ERR;
553 /* Note that we are knowingly leaking the FIFO fd here. This
554 * way, logind can watch us die. If we closed it here it would
555 * not have any clue when that is completed. Given that one
556 * cannot really have multiple PAM sessions open from the same
557 * process this means we will leak one FD at max. */