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 elogind.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 elogind.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 elogind.cpu_weight: %s, ignoring.", limit);
276 pam_syslog(handle, LOG_WARNING, "Failed to parse elogind.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 #if 0 /// with elogind, it is always a "logind system".
308 /* Make this a NOP on non-logind systems */
309 if (!logind_running())
313 if (parse_argv(handle,
318 return PAM_SESSION_ERR;
321 pam_syslog(handle, LOG_DEBUG, "pam-elogind initializing");
323 r = get_user_data(handle, &username, &pw);
324 if (r != PAM_SUCCESS) {
325 pam_syslog(handle, LOG_ERR, "Failed to get user data.");
329 /* Make sure we don't enter a loop by talking to
330 * elogind when it is actually waiting for the
331 * background to finish start-up. If the service is
332 * "elogind-user" we simply set XDG_RUNTIME_DIR and
335 pam_get_item(handle, PAM_SERVICE, (const void**) &service);
336 if (streq_ptr(service, "elogind-user")) {
337 _cleanup_free_ char *rt = NULL;
339 if (asprintf(&rt, "/run/user/"UID_FMT, pw->pw_uid) < 0)
342 r = pam_misc_setenv(handle, "XDG_RUNTIME_DIR", rt, 0);
343 if (r != PAM_SUCCESS) {
344 pam_syslog(handle, LOG_ERR, "Failed to set runtime dir.");
348 r = export_legacy_dbus_address(handle, pw->pw_uid, rt);
349 if (r != PAM_SUCCESS)
355 /* Otherwise, we ask logind to create a session for us */
357 pam_get_item(handle, PAM_XDISPLAY, (const void**) &display);
358 pam_get_item(handle, PAM_TTY, (const void**) &tty);
359 pam_get_item(handle, PAM_RUSER, (const void**) &remote_user);
360 pam_get_item(handle, PAM_RHOST, (const void**) &remote_host);
362 seat = pam_getenv(handle, "XDG_SEAT");
364 seat = getenv("XDG_SEAT");
366 cvtnr = pam_getenv(handle, "XDG_VTNR");
368 cvtnr = getenv("XDG_VTNR");
370 type = pam_getenv(handle, "XDG_SESSION_TYPE");
372 type = getenv("XDG_SESSION_TYPE");
376 class = pam_getenv(handle, "XDG_SESSION_CLASS");
378 class = getenv("XDG_SESSION_CLASS");
382 desktop = pam_getenv(handle, "XDG_SESSION_DESKTOP");
383 if (isempty(desktop))
384 desktop = getenv("XDG_SESSION_DESKTOP");
388 if (strchr(tty, ':')) {
389 /* A tty with a colon is usually an X11 display,
390 * placed there to show up in utmp. We rearrange
391 * things and don't pretend that an X display was a
394 if (isempty(display))
397 } else if (streq(tty, "cron")) {
398 /* cron has been setting PAM_TTY to "cron" for a very
399 * long time and it probably shouldn't stop doing that
400 * for compatibility reasons. */
401 type = "unspecified";
402 class = "background";
404 } else if (streq(tty, "ssh")) {
405 /* ssh has been setting PAM_TTY to "ssh" for a very
406 * long time and probably shouldn't stop doing that
407 * for compatibility reasons. */
412 /* Chop off leading /dev prefix that some clients specify, but others do not. */
413 tty = skip_dev_prefix(tty);
415 /* If this fails vtnr will be 0, that's intended */
417 (void) safe_atou32(cvtnr, &vtnr);
419 if (!isempty(display) && !vtnr) {
421 get_seat_from_display(display, &seat, &vtnr);
422 else if (streq(seat, "seat0"))
423 get_seat_from_display(display, NULL, &vtnr);
426 if (seat && !streq(seat, "seat0") && vtnr != 0) {
427 pam_syslog(handle, LOG_DEBUG, "Ignoring vtnr %"PRIu32" for %s which is not seat0", vtnr, seat);
432 type = !isempty(display) ? "x11" :
433 !isempty(tty) ? "tty" : "unspecified";
436 class = streq(type, "unspecified") ? "background" : "user";
438 remote = !isempty(remote_host) && !is_localhost(remote_host);
440 (void) pam_get_data(handle, "elogind.memory_max", (const void **)&memory_max);
441 (void) pam_get_data(handle, "elogind.tasks_max", (const void **)&tasks_max);
442 (void) pam_get_data(handle, "elogind.cpu_weight", (const void **)&cpu_weight);
443 (void) pam_get_data(handle, "elogind.io_weight", (const void **)&io_weight);
445 /* Talk to logind over the message bus */
447 r = sd_bus_open_system(&bus);
449 pam_syslog(handle, LOG_ERR, "Failed to connect to system bus: %s", strerror(-r));
450 return PAM_SESSION_ERR;
454 pam_syslog(handle, LOG_DEBUG, "Asking logind to create session: "
455 "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",
456 pw->pw_uid, getpid_cached(),
458 type, class, strempty(desktop),
459 strempty(seat), vtnr, strempty(tty), strempty(display),
460 yes_no(remote), strempty(remote_user), strempty(remote_host));
461 pam_syslog(handle, LOG_DEBUG, "Session limits: "
462 "memory_max=%s tasks_max=%s cpu_weight=%s io_weight=%s",
463 strna(memory_max), strna(tasks_max), strna(cpu_weight), strna(io_weight));
466 r = sd_bus_message_new_method_call(
469 "org.freedesktop.login1",
470 "/org/freedesktop/login1",
471 "org.freedesktop.login1.Manager",
474 pam_syslog(handle, LOG_ERR, "Failed to create CreateSession method call: %s", strerror(-r));
475 return PAM_SESSION_ERR;
478 r = sd_bus_message_append(m, "uusssssussbss",
479 (uint32_t) pw->pw_uid,
480 (uint32_t) getpid_cached(),
493 pam_syslog(handle, LOG_ERR, "Failed to append to bus message: %s", strerror(-r));
494 return PAM_SESSION_ERR;
497 r = sd_bus_message_open_container(m, 'a', "(sv)");
499 pam_syslog(handle, LOG_ERR, "Failed to open message container: %s", strerror(-r));
500 return PAM_SYSTEM_ERR;
503 r = append_session_memory_max(handle, m, memory_max);
505 return PAM_SESSION_ERR;
507 r = append_session_tasks_max(handle, m, tasks_max);
509 return PAM_SESSION_ERR;
511 r = append_session_cg_weight(handle, m, cpu_weight, "CPUWeight");
513 return PAM_SESSION_ERR;
515 r = append_session_cg_weight(handle, m, io_weight, "IOWeight");
517 return PAM_SESSION_ERR;
519 r = sd_bus_message_close_container(m);
521 pam_syslog(handle, LOG_ERR, "Failed to close message container: %s", strerror(-r));
522 return PAM_SYSTEM_ERR;
525 r = sd_bus_call(bus, m, 0, &error, &reply);
527 if (sd_bus_error_has_name(&error, BUS_ERROR_SESSION_BUSY)) {
528 pam_syslog(handle, LOG_DEBUG, "Cannot create session: %s", bus_error_message(&error, r));
531 pam_syslog(handle, LOG_ERR, "Failed to create session: %s", bus_error_message(&error, r));
532 return PAM_SYSTEM_ERR;
536 r = sd_bus_message_read(reply,
547 pam_syslog(handle, LOG_ERR, "Failed to parse message: %s", strerror(-r));
548 return PAM_SESSION_ERR;
552 pam_syslog(handle, LOG_DEBUG, "Reply from logind: "
553 "id=%s object_path=%s runtime_path=%s session_fd=%d seat=%s vtnr=%u original_uid=%u",
554 id, object_path, runtime_path, session_fd, seat, vtnr, original_uid);
556 r = pam_misc_setenv(handle, "XDG_SESSION_ID", id, 0);
557 if (r != PAM_SUCCESS) {
558 pam_syslog(handle, LOG_ERR, "Failed to set session id.");
562 if (original_uid == pw->pw_uid) {
563 /* Don't set $XDG_RUNTIME_DIR if the user we now
564 * authenticated for does not match the original user
565 * of the session. We do this in order not to result
566 * in privileged apps clobbering the runtime directory
569 r = pam_misc_setenv(handle, "XDG_RUNTIME_DIR", runtime_path, 0);
570 if (r != PAM_SUCCESS) {
571 pam_syslog(handle, LOG_ERR, "Failed to set runtime dir.");
575 r = export_legacy_dbus_address(handle, pw->pw_uid, runtime_path);
576 if (r != PAM_SUCCESS)
580 if (!isempty(seat)) {
581 r = pam_misc_setenv(handle, "XDG_SEAT", seat, 0);
582 if (r != PAM_SUCCESS) {
583 pam_syslog(handle, LOG_ERR, "Failed to set seat.");
589 char buf[DECIMAL_STR_MAX(vtnr)];
590 sprintf(buf, "%u", vtnr);
592 r = pam_misc_setenv(handle, "XDG_VTNR", buf, 0);
593 if (r != PAM_SUCCESS) {
594 pam_syslog(handle, LOG_ERR, "Failed to set virtual terminal number.");
599 r = pam_set_data(handle, "systemd.existing", INT_TO_PTR(!!existing), NULL);
600 if (r != PAM_SUCCESS) {
601 pam_syslog(handle, LOG_ERR, "Failed to install existing flag.");
605 if (session_fd >= 0) {
606 session_fd = fcntl(session_fd, F_DUPFD_CLOEXEC, 3);
607 if (session_fd < 0) {
608 pam_syslog(handle, LOG_ERR, "Failed to dup session fd: %m");
609 return PAM_SESSION_ERR;
612 r = pam_set_data(handle, "systemd.session-fd", FD_TO_PTR(session_fd), NULL);
613 if (r != PAM_SUCCESS) {
614 pam_syslog(handle, LOG_ERR, "Failed to install session fd.");
615 safe_close(session_fd);
623 _public_ PAM_EXTERN int pam_sm_close_session(
624 pam_handle_t *handle,
626 int argc, const char **argv) {
628 _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
629 _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
630 const void *existing = NULL;
636 /* Only release session if it wasn't pre-existing when we
637 * tried to create it */
638 pam_get_data(handle, "systemd.existing", &existing);
640 id = pam_getenv(handle, "XDG_SESSION_ID");
641 if (id && !existing) {
643 /* Before we go and close the FIFO we need to tell
644 * logind that this is a clean session shutdown, so
645 * that it doesn't just go and slaughter us
646 * immediately after closing the fd */
648 r = sd_bus_open_system(&bus);
650 pam_syslog(handle, LOG_ERR, "Failed to connect to system bus: %s", strerror(-r));
651 return PAM_SESSION_ERR;
654 r = sd_bus_call_method(bus,
655 "org.freedesktop.login1",
656 "/org/freedesktop/login1",
657 "org.freedesktop.login1.Manager",
664 pam_syslog(handle, LOG_ERR, "Failed to release session: %s", bus_error_message(&error, r));
665 return PAM_SESSION_ERR;
669 /* Note that we are knowingly leaking the FIFO fd here. This
670 * way, logind can watch us die. If we closed it here it would
671 * not have any clue when that is completed. Given that one
672 * cannot really have multiple PAM sessions open from the same
673 * process this means we will leak one FD at max. */