]> git.ipfire.org Git - thirdparty/systemd.git/blame - src/login/pam_systemd.c
Merge pull request #15785 from poettering/pam-sudo-fixes-part1
[thirdparty/systemd.git] / src / login / pam_systemd.c
CommitLineData
53e1b683 1/* SPDX-License-Identifier: LGPL-2.1+ */
8c6db833 2
00229fe4 3#include <endian.h>
8c6db833
LP
4#include <errno.h>
5#include <fcntl.h>
8c6db833 6#include <pwd.h>
8c6db833 7#include <security/_pam_macros.h>
8c6db833
LP
8#include <security/pam_ext.h>
9#include <security/pam_misc.h>
00229fe4
LP
10#include <security/pam_modules.h>
11#include <security/pam_modutil.h>
12#include <sys/file.h>
ca78ad1d 13#include <sys/stat.h>
e21d9060 14#include <sys/sysmacros.h>
ca78ad1d
ZJS
15#include <sys/types.h>
16#include <unistd.h>
8c6db833 17
b5efdb8a 18#include "alloc-util.h"
430f0182 19#include "audit-util.h"
00229fe4
LP
20#include "bus-common-errors.h"
21#include "bus-error.h"
47094ce0 22#include "bus-internal.h"
ffcfcb6b 23#include "bus-util.h"
fdb3deca 24#include "cgroup-setup.h"
4bbccb02 25#include "errno-util.h"
3ffd4af2 26#include "fd-util.h"
a5c32cff 27#include "fileio.h"
f97b34a6 28#include "format-util.h"
f9c1f4e1 29#include "fs-util.h"
958b66ea 30#include "hostname-util.h"
f9c1f4e1 31#include "locale-util.h"
00229fe4
LP
32#include "login-util.h"
33#include "macro.h"
d750dde2 34#include "pam-util.h"
6bedfcbb 35#include "parse-util.h"
e37e5ed3 36#include "path-util.h"
df0ff127 37#include "process-util.h"
f9c1f4e1 38#include "rlimit-util.h"
00229fe4 39#include "socket-util.h"
055c08ef 40#include "stdio-util.h"
00229fe4
LP
41#include "strv.h"
42#include "terminal-util.h"
9ab0d3eb
LP
43#include "user-util.h"
44#include "userdb.h"
8c6db833 45
fbcb6300
LP
46#define LOGIN_SLOW_BUS_CALL_TIMEOUT_USEC (2*USEC_PER_MINUTE)
47
baae0358
LP
48static int parse_argv(
49 pam_handle_t *handle,
50 int argc, const char **argv,
51 const char **class,
49ebd11f 52 const char **type,
f5cb2820 53 const char **desktop,
baae0358 54 bool *debug) {
8c6db833
LP
55
56 unsigned i;
57
58 assert(argc >= 0);
59 assert(argc == 0 || argv);
60
49ebd11f 61 for (i = 0; i < (unsigned) argc; i++) {
d9608d40
LP
62 const char *p;
63
64 if ((p = startswith(argv[i], "class="))) {
485507b8 65 if (class)
d9608d40 66 *class = p;
485507b8 67
d9608d40 68 } else if ((p = startswith(argv[i], "type="))) {
49ebd11f 69 if (type)
d9608d40 70 *type = p;
49ebd11f 71
d9608d40 72 } else if ((p = startswith(argv[i], "desktop="))) {
f5cb2820 73 if (desktop)
d9608d40 74 *desktop = p;
f5cb2820 75
05a049cc
ZJS
76 } else if (streq(argv[i], "debug")) {
77 if (debug)
78 *debug = true;
fb6becb4 79
d9608d40 80 } else if ((p = startswith(argv[i], "debug="))) {
05a049cc 81 int k;
0e318cad 82
d9608d40 83 k = parse_boolean(p);
05a049cc 84 if (k < 0)
d9608d40 85 pam_syslog(handle, LOG_WARNING, "Failed to parse debug= argument, ignoring: %s", p);
05a049cc 86 else if (debug)
0e318cad
MS
87 *debug = k;
88
05a049cc 89 } else
fb6becb4 90 pam_syslog(handle, LOG_WARNING, "Unknown parameter '%s', ignoring", argv[i]);
49ebd11f 91 }
8c6db833 92
8c6db833
LP
93 return 0;
94}
95
9ab0d3eb 96static int acquire_user_record(
8c6db833 97 pam_handle_t *handle,
9ab0d3eb 98 UserRecord **ret_record) {
8c6db833 99
9ab0d3eb
LP
100 _cleanup_(user_record_unrefp) UserRecord *ur = NULL;
101 const char *username = NULL, *json = NULL;
8c6db833
LP
102 int r;
103
104 assert(handle);
8c6db833 105
baae0358
LP
106 r = pam_get_user(handle, &username, NULL);
107 if (r != PAM_SUCCESS) {
d9608d40 108 pam_syslog(handle, LOG_ERR, "Failed to get user name: %s", pam_strerror(handle, r));
baae0358
LP
109 return r;
110 }
d90b9d27 111
baae0358
LP
112 if (isempty(username)) {
113 pam_syslog(handle, LOG_ERR, "User name not valid.");
9ab0d3eb 114 return PAM_SERVICE_ERR;
8c6db833
LP
115 }
116
9ab0d3eb
LP
117 /* If pam_systemd_homed (or some other module) already acqired the user record we can reuse it
118 * here. */
119 r = pam_get_data(handle, "systemd-user-record", (const void**) &json);
120 if (r != PAM_SUCCESS || !json) {
121 _cleanup_free_ char *formatted = NULL;
122
123 if (!IN_SET(r, PAM_SUCCESS, PAM_NO_MODULE_DATA)) {
124 pam_syslog(handle, LOG_ERR, "Failed to get PAM user record data: %s", pam_strerror(handle, r));
125 return r;
126 }
127
128 /* Request the record ourselves */
129 r = userdb_by_name(username, 0, &ur);
130 if (r < 0) {
131 pam_syslog(handle, LOG_ERR, "Failed to get user record: %s", strerror_safe(r));
132 return PAM_USER_UNKNOWN;
133 }
134
135 r = json_variant_format(ur->json, 0, &formatted);
136 if (r < 0) {
137 pam_syslog(handle, LOG_ERR, "Failed to format user JSON: %s", strerror_safe(r));
138 return PAM_SERVICE_ERR;
139 }
140
141 /* And cache it for everyone else */
142 r = pam_set_data(handle, "systemd-user-record", formatted, pam_cleanup_free);
143 if (r < 0) {
144 pam_syslog(handle, LOG_ERR, "Failed to set PAM user record data: %s", pam_strerror(handle, r));
145 return r;
146 }
147
148 TAKE_PTR(formatted);
149 } else {
150 _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
151
152 /* Parse cached record */
153 r = json_parse(json, JSON_PARSE_SENSITIVE, &v, NULL, NULL);
154 if (r < 0) {
155 pam_syslog(handle, LOG_ERR, "Failed to parse JSON user record: %s", strerror_safe(r));
156 return PAM_SERVICE_ERR;
157 }
158
159 ur = user_record_new();
160 if (!ur)
161 return pam_log_oom(handle);
162
163 r = user_record_load(ur, v, USER_RECORD_LOAD_REFUSE_SECRET);
164 if (r < 0) {
165 pam_syslog(handle, LOG_ERR, "Failed to load user record: %s", strerror_safe(r));
166 return PAM_SERVICE_ERR;
167 }
168
169 /* Safety check if cached record actually matches what we are looking for */
170 if (!streq_ptr(username, ur->user_name)) {
171 pam_syslog(handle, LOG_ERR, "Acquired user record does not match user name.");
172 return PAM_SERVICE_ERR;
173 }
174 }
175
176 if (!uid_is_valid(ur->uid)) {
177 pam_syslog(handle, LOG_ERR, "Acquired user record does not have a UID.");
178 return PAM_SERVICE_ERR;
8c6db833
LP
179 }
180
9ab0d3eb
LP
181 if (ret_record)
182 *ret_record = TAKE_PTR(ur);
8c6db833
LP
183
184 return PAM_SUCCESS;
185}
186
ecd5f1a9
LP
187static bool display_is_local(const char *display) {
188 assert(display);
189
190 return
191 display[0] == ':' &&
192 display[1] >= '0' &&
193 display[1] <= '9';
194}
195
f7b8b5c4
LP
196static int socket_from_display(const char *display, char **path) {
197 size_t k;
198 char *f, *c;
199
200 assert(display);
201 assert(path);
202
203 if (!display_is_local(display))
204 return -EINVAL;
205
206 k = strspn(display+1, "0123456789");
207
208 f = new(char, STRLEN("/tmp/.X11-unix/X") + k + 1);
209 if (!f)
210 return -ENOMEM;
211
212 c = stpcpy(f, "/tmp/.X11-unix/X");
213 memcpy(c, display+1, k);
214 c[k] = 0;
215
216 *path = f;
217
218 return 0;
219}
220
4d6d6518 221static int get_seat_from_display(const char *display, const char **seat, uint32_t *vtnr) {
f36a9d59
ZJS
222 union sockaddr_union sa;
223 socklen_t sa_len;
e21d9060 224 _cleanup_free_ char *p = NULL, *sys_path = NULL, *tty = NULL;
baae0358 225 _cleanup_close_ int fd = -1;
4d6d6518 226 struct ucred ucred;
f36a9d59 227 int v, r;
e21d9060 228 dev_t display_ctty;
4d6d6518
LP
229
230 assert(display);
4d6d6518
LP
231 assert(vtnr);
232
233 /* We deduce the X11 socket from the display name, then use
234 * SO_PEERCRED to determine the X11 server process, ask for
235 * the controlling tty of that and if it's a VC then we know
236 * the seat and the virtual terminal. Sounds ugly, is only
237 * semi-ugly. */
238
239 r = socket_from_display(display, &p);
240 if (r < 0)
241 return r;
f36a9d59
ZJS
242 r = sockaddr_un_set_path(&sa.un, p);
243 if (r < 0)
244 return r;
245 sa_len = r;
4d6d6518
LP
246
247 fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0);
b92bea5d 248 if (fd < 0)
4d6d6518 249 return -errno;
4d6d6518 250
f36a9d59 251 if (connect(fd, &sa.sa, sa_len) < 0)
4d6d6518 252 return -errno;
4d6d6518 253
eff05270 254 r = getpeercred(fd, &ucred);
4d6d6518 255 if (r < 0)
eff05270 256 return r;
4d6d6518 257
e21d9060
TM
258 r = get_ctty_devnr(ucred.pid, &display_ctty);
259 if (r < 0)
260 return r;
261
262 if (asprintf(&sys_path, "/sys/dev/char/%d:%d", major(display_ctty), minor(display_ctty)) < 0)
263 return -ENOMEM;
264 r = readlink_value(sys_path, &tty);
4d6d6518
LP
265 if (r < 0)
266 return r;
267
268 v = vtnr_from_tty(tty);
4d6d6518
LP
269 if (v < 0)
270 return v;
271 else if (v == 0)
272 return -ENOENT;
273
fc7985ed
LP
274 if (seat)
275 *seat = "seat0";
4d6d6518
LP
276 *vtnr = (uint32_t) v;
277
278 return 0;
279}
280
00efd498
ZJS
281static int export_legacy_dbus_address(
282 pam_handle_t *handle,
00efd498
ZJS
283 const char *runtime) {
284
15ee6c20
ZJS
285 const char *s;
286 _cleanup_free_ char *t = NULL;
00efd498
ZJS
287 int r = PAM_BUF_ERR;
288
15ee6c20
ZJS
289 /* We need to export $DBUS_SESSION_BUS_ADDRESS because various applications will not connect
290 * correctly to the bus without it. This setting matches what dbus.socket does for the user
291 * session using 'systemctl --user set-environment'. We want to have the same configuration
292 * in processes started from the PAM session.
293 *
294 * The setting of the address is guarded by the access() check because it is also possible to compile
295 * dbus without --enable-user-session, in which case this socket is not used, and
296 * $DBUS_SESSION_BUS_ADDRESS should not be set. An alternative approach would to not do the access()
297 * check here, and let applications try on their own, by using "unix:path=%s/bus;autolaunch:". But we
298 * expect the socket to be present by the time we do this check, so we can just as well check once
299 * here. */
300
301 s = strjoina(runtime, "/bus");
302 if (access(s, F_OK) < 0)
303 return PAM_SUCCESS;
304
305 if (asprintf(&t, DEFAULT_USER_BUS_ADDRESS_FMT, runtime) < 0)
d750dde2 306 return pam_log_oom(handle);
00efd498 307
15ee6c20 308 r = pam_misc_setenv(handle, "DBUS_SESSION_BUS_ADDRESS", t, 0);
d750dde2
LP
309 if (r != PAM_SUCCESS) {
310 pam_syslog(handle, LOG_ERR, "Failed to set bus variable: %s", pam_strerror(handle, r));
311 return r;
312 }
00efd498
ZJS
313
314 return PAM_SUCCESS;
00efd498
ZJS
315}
316
22f93314
JS
317static int append_session_memory_max(pam_handle_t *handle, sd_bus_message *m, const char *limit) {
318 uint64_t val;
319 int r;
320
321 if (isempty(limit))
7bfbf6cc 322 return PAM_SUCCESS;
22f93314
JS
323
324 if (streq(limit, "infinity")) {
325 r = sd_bus_message_append(m, "(sv)", "MemoryMax", "t", (uint64_t)-1);
d750dde2
LP
326 if (r < 0)
327 return pam_bus_log_create_error(handle, r);
328
7bfbf6cc 329 return PAM_SUCCESS;
d750dde2
LP
330 }
331
332 r = parse_permille(limit);
333 if (r >= 0) {
334 r = sd_bus_message_append(m, "(sv)", "MemoryMaxScale", "u", (uint32_t) (((uint64_t) r * UINT32_MAX) / 1000U));
335 if (r < 0)
336 return pam_bus_log_create_error(handle, r);
337
7bfbf6cc 338 return PAM_SUCCESS;
d750dde2
LP
339 }
340
341 r = parse_size(limit, 1024, &val);
342 if (r >= 0) {
343 r = sd_bus_message_append(m, "(sv)", "MemoryMax", "t", val);
344 if (r < 0)
345 return pam_bus_log_create_error(handle, r);
346
7bfbf6cc 347 return PAM_SUCCESS;
22f93314
JS
348 }
349
d750dde2 350 pam_syslog(handle, LOG_WARNING, "Failed to parse systemd.memory_max, ignoring: %s", limit);
7bfbf6cc 351 return PAM_SUCCESS;
22f93314
JS
352}
353
adc09af2
PW
354static int append_session_runtime_max_sec(pam_handle_t *handle, sd_bus_message *m, const char *limit) {
355 usec_t val;
356 int r;
357
358 /* No need to parse "infinity" here, it will be set by default later in scope_init() */
359 if (isempty(limit) || streq(limit, "infinity"))
7bfbf6cc 360 return PAM_SUCCESS;
adc09af2
PW
361
362 r = parse_sec(limit, &val);
363 if (r >= 0) {
364 r = sd_bus_message_append(m, "(sv)", "RuntimeMaxUSec", "t", (uint64_t) val);
7bfbf6cc
LP
365 if (r < 0)
366 return pam_bus_log_create_error(handle, r);
adc09af2
PW
367 } else
368 pam_syslog(handle, LOG_WARNING, "Failed to parse systemd.runtime_max_sec: %s, ignoring.", limit);
369
7bfbf6cc 370 return PAM_SUCCESS;
adc09af2
PW
371}
372
5fdfbbd5 373static int append_session_tasks_max(pam_handle_t *handle, sd_bus_message *m, const char *limit) {
22f93314
JS
374 uint64_t val;
375 int r;
376
377 /* No need to parse "infinity" here, it will be set unconditionally later in manager_start_scope() */
378 if (isempty(limit) || streq(limit, "infinity"))
7bfbf6cc 379 return PAM_SUCCESS;
22f93314
JS
380
381 r = safe_atou64(limit, &val);
382 if (r >= 0) {
383 r = sd_bus_message_append(m, "(sv)", "TasksMax", "t", val);
d750dde2
LP
384 if (r < 0)
385 return pam_bus_log_create_error(handle, r);
22f93314 386 } else
d750dde2 387 pam_syslog(handle, LOG_WARNING, "Failed to parse systemd.tasks_max, ignoring: %s", limit);
22f93314 388
7bfbf6cc 389 return PAM_SUCCESS;
22f93314
JS
390}
391
392static int append_session_cg_weight(pam_handle_t *handle, sd_bus_message *m, const char *limit, const char *field) {
393 uint64_t val;
394 int r;
395
36a4dbae 396 if (isempty(limit))
7bfbf6cc 397 return PAM_SUCCESS;
36a4dbae
LP
398
399 r = cg_weight_parse(limit, &val);
400 if (r >= 0) {
401 r = sd_bus_message_append(m, "(sv)", field, "t", val);
d750dde2
LP
402 if (r < 0)
403 return pam_bus_log_create_error(handle, r);
36a4dbae 404 } else if (streq(field, "CPUWeight"))
d750dde2 405 pam_syslog(handle, LOG_WARNING, "Failed to parse systemd.cpu_weight, ignoring: %s", limit);
36a4dbae 406 else
d750dde2 407 pam_syslog(handle, LOG_WARNING, "Failed to parse systemd.io_weight, ignoring: %s", limit);
22f93314 408
7bfbf6cc 409 return PAM_SUCCESS;
22f93314
JS
410}
411
0ecc1c9d
LP
412static const char* getenv_harder(pam_handle_t *handle, const char *key, const char *fallback) {
413 const char *v;
414
415 assert(handle);
416 assert(key);
417
5238e957 418 /* Looks for an environment variable, preferably in the environment block associated with the
83d4ab55
LP
419 * specified PAM handle, falling back to the process' block instead. Why check both? Because we want
420 * to permit configuration of session properties from unit files that invoke PAM services, so that
421 * PAM services don't have to be reworked to set systemd-specific properties, but these properties
422 * can still be set from the unit file Environment= block. */
0ecc1c9d
LP
423
424 v = pam_getenv(handle, key);
425 if (!isempty(v))
426 return v;
427
83d4ab55
LP
428 /* We use secure_getenv() here, since we might get loaded into su/sudo, which are SUID. Ideally
429 * they'd clean up the environment before invoking foreign code (such as PAM modules), but alas they
430 * currently don't (to be precise, they clean up the environment they pass to their children, but
431 * not their own environ[]). */
432 v = secure_getenv(key);
0ecc1c9d
LP
433 if (!isempty(v))
434 return v;
435
436 return fallback;
437}
438
d6baaa69
LP
439static int update_environment(pam_handle_t *handle, const char *key, const char *value) {
440 int r;
441
442 assert(handle);
443 assert(key);
444
445 /* Updates the environment, but only if there's actually a value set. Also, log about errors */
446
447 if (isempty(value))
448 return PAM_SUCCESS;
449
450 r = pam_misc_setenv(handle, key, value, 0);
451 if (r != PAM_SUCCESS)
d9608d40 452 pam_syslog(handle, LOG_ERR, "Failed to set environment variable %s: %s", key, pam_strerror(handle, r));
d6baaa69
LP
453
454 return r;
455}
456
b9217112
LP
457static bool validate_runtime_directory(pam_handle_t *handle, const char *path, uid_t uid) {
458 struct stat st;
459
dca81e28 460 assert(handle);
b9217112
LP
461 assert(path);
462
463 /* Just some extra paranoia: let's not set $XDG_RUNTIME_DIR if the directory we'd set it to isn't actually set
464 * up properly for us. */
465
466 if (lstat(path, &st) < 0) {
4bbccb02 467 pam_syslog(handle, LOG_ERR, "Failed to stat() runtime directory '%s': %s", path, strerror_safe(errno));
b9217112
LP
468 goto fail;
469 }
470
471 if (!S_ISDIR(st.st_mode)) {
472 pam_syslog(handle, LOG_ERR, "Runtime directory '%s' is not actually a directory.", path);
473 goto fail;
474 }
475
476 if (st.st_uid != uid) {
477 pam_syslog(handle, LOG_ERR, "Runtime directory '%s' is not owned by UID " UID_FMT ", as it should.", path, uid);
478 goto fail;
479 }
480
481 return true;
482
483fail:
484 pam_syslog(handle, LOG_WARNING, "Not setting $XDG_RUNTIME_DIR, as the directory is not in order.");
485 return false;
486}
487
f9c1f4e1
LP
488static int pam_putenv_and_log(pam_handle_t *handle, const char *e, bool debug) {
489 int r;
490
491 assert(handle);
492 assert(e);
493
494 r = pam_putenv(handle, e);
495 if (r != PAM_SUCCESS) {
496 pam_syslog(handle, LOG_ERR, "Failed to set PAM environment variable %s: %s", e, pam_strerror(handle, r));
497 return r;
498 }
499
500 if (debug)
501 pam_syslog(handle, LOG_DEBUG, "PAM environment variable %s set based on user record.", e);
502
503 return PAM_SUCCESS;
504}
505
506static int apply_user_record_settings(pam_handle_t *handle, UserRecord *ur, bool debug) {
507 char **i;
508 int r;
509
510 assert(handle);
511 assert(ur);
512
513 if (ur->umask != MODE_INVALID) {
514 umask(ur->umask);
515
516 if (debug)
517 pam_syslog(handle, LOG_DEBUG, "Set user umask to %04o based on user record.", ur->umask);
518 }
519
520 STRV_FOREACH(i, ur->environment) {
521 _cleanup_free_ char *n = NULL;
522 const char *e;
523
524 assert_se(e = strchr(*i, '=')); /* environment was already validated while parsing JSON record, this thus must hold */
525
526 n = strndup(*i, e - *i);
527 if (!n)
528 return pam_log_oom(handle);
529
530 if (pam_getenv(handle, n)) {
531 if (debug)
532 pam_syslog(handle, LOG_DEBUG, "PAM environment variable $%s already set, not changing based on record.", *i);
533 continue;
534 }
535
536 r = pam_putenv_and_log(handle, *i, debug);
537 if (r != PAM_SUCCESS)
538 return r;
539 }
540
541 if (ur->email_address) {
542 if (pam_getenv(handle, "EMAIL")) {
543 if (debug)
544 pam_syslog(handle, LOG_DEBUG, "PAM environment variable $EMAIL already set, not changing based on user record.");
545 } else {
546 _cleanup_free_ char *joined = NULL;
547
548 joined = strjoin("EMAIL=", ur->email_address);
549 if (!joined)
550 return pam_log_oom(handle);
551
552 r = pam_putenv_and_log(handle, joined, debug);
553 if (r != PAM_SUCCESS)
554 return r;
555 }
556 }
557
558 if (ur->time_zone) {
559 if (pam_getenv(handle, "TZ")) {
560 if (debug)
561 pam_syslog(handle, LOG_DEBUG, "PAM environment variable $TZ already set, not changing based on user record.");
562 } else if (!timezone_is_valid(ur->time_zone, LOG_DEBUG)) {
563 if (debug)
564 pam_syslog(handle, LOG_DEBUG, "Time zone specified in user record is not valid locally, not setting $TZ.");
565 } else {
566 _cleanup_free_ char *joined = NULL;
567
568 joined = strjoin("TZ=:", ur->time_zone);
569 if (!joined)
570 return pam_log_oom(handle);
571
572 r = pam_putenv_and_log(handle, joined, debug);
573 if (r != PAM_SUCCESS)
574 return r;
575 }
576 }
577
578 if (ur->preferred_language) {
579 if (pam_getenv(handle, "LANG")) {
580 if (debug)
581 pam_syslog(handle, LOG_DEBUG, "PAM environment variable $LANG already set, not changing based on user record.");
a00a78b8 582 } else if (locale_is_installed(ur->preferred_language) <= 0) {
f9c1f4e1 583 if (debug)
a00a78b8 584 pam_syslog(handle, LOG_DEBUG, "Preferred language specified in user record is not valid or not installed, not setting $LANG.");
f9c1f4e1
LP
585 } else {
586 _cleanup_free_ char *joined = NULL;
587
588 joined = strjoin("LANG=", ur->preferred_language);
589 if (!joined)
590 return pam_log_oom(handle);
591
592 r = pam_putenv_and_log(handle, joined, debug);
593 if (r != PAM_SUCCESS)
594 return r;
595 }
596 }
597
598 if (nice_is_valid(ur->nice_level)) {
599 if (nice(ur->nice_level) < 0)
600 pam_syslog(handle, LOG_ERR, "Failed to set nice level to %i, ignoring: %s", ur->nice_level, strerror_safe(errno));
601 else if (debug)
602 pam_syslog(handle, LOG_DEBUG, "Nice level set, based on user record.");
603 }
604
605 for (int rl = 0; rl < _RLIMIT_MAX; rl++) {
606
607 if (!ur->rlimits[rl])
608 continue;
609
610 r = setrlimit_closest(rl, ur->rlimits[rl]);
611 if (r < 0)
612 pam_syslog(handle, LOG_ERR, "Failed to set resource limit %s, ignoring: %s", rlimit_to_string(rl), strerror_safe(r));
613 else if (debug)
614 pam_syslog(handle, LOG_DEBUG, "Resource limit %s set, based on user record.", rlimit_to_string(rl));
615 }
616
617 return PAM_SUCCESS;
618}
619
98a28fef 620_public_ PAM_EXTERN int pam_sm_open_session(
8c6db833
LP
621 pam_handle_t *handle,
622 int flags,
623 int argc, const char **argv) {
624
4afd3348 625 _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
22f93314 626 _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL, *reply = NULL;
d1529c9e 627 const char
9ab0d3eb 628 *id, *object_path, *runtime_path,
d1529c9e
LP
629 *service = NULL,
630 *tty = NULL, *display = NULL,
631 *remote_user = NULL, *remote_host = NULL,
632 *seat = NULL,
633 *type = NULL, *class = NULL,
f5cb2820 634 *class_pam = NULL, *type_pam = NULL, *cvtnr = NULL, *desktop = NULL, *desktop_pam = NULL,
adc09af2 635 *memory_max = NULL, *tasks_max = NULL, *cpu_weight = NULL, *io_weight = NULL, *runtime_max_sec = NULL;
4afd3348 636 _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
9ab0d3eb 637 _cleanup_(user_record_unrefp) UserRecord *ur = NULL;
d1529c9e 638 int session_fd = -1, existing, r;
d1529c9e 639 bool debug = false, remote;
baae0358
LP
640 uint32_t vtnr = 0;
641 uid_t original_uid;
8c6db833 642
ffcfcb6b 643 assert(handle);
98a28fef 644
79d860fe
MP
645 /* Make this a NOP on non-logind systems */
646 if (!logind_running())
8c6db833
LP
647 return PAM_SUCCESS;
648
e9fbc77c
LP
649 if (parse_argv(handle,
650 argc, argv,
fb6becb4 651 &class_pam,
49ebd11f 652 &type_pam,
f5cb2820 653 &desktop_pam,
5a330cda
ZJS
654 &debug) < 0)
655 return PAM_SESSION_ERR;
74fe1fe3 656
baae0358 657 if (debug)
3831838a 658 pam_syslog(handle, LOG_DEBUG, "pam-systemd initializing");
baae0358 659
9ab0d3eb 660 r = acquire_user_record(handle, &ur);
42e66809 661 if (r != PAM_SUCCESS)
5a330cda 662 return r;
8c6db833 663
30b2c336
LP
664 /* Make sure we don't enter a loop by talking to
665 * systemd-logind when it is actually waiting for the
666 * background to finish start-up. If the service is
5c390a4a 667 * "systemd-user" we simply set XDG_RUNTIME_DIR and
30b2c336
LP
668 * leave. */
669
1798f5af 670 (void) pam_get_item(handle, PAM_SERVICE, (const void**) &service);
5c390a4a 671 if (streq_ptr(service, "systemd-user")) {
055c08ef 672 char rt[STRLEN("/run/user/") + DECIMAL_STR_MAX(uid_t)];
30b2c336 673
9ab0d3eb
LP
674 xsprintf(rt, "/run/user/"UID_FMT, ur->uid);
675 if (validate_runtime_directory(handle, rt, ur->uid)) {
b9217112
LP
676 r = pam_misc_setenv(handle, "XDG_RUNTIME_DIR", rt, 0);
677 if (r != PAM_SUCCESS) {
d9608d40 678 pam_syslog(handle, LOG_ERR, "Failed to set runtime dir: %s", pam_strerror(handle, r));
b9217112
LP
679 return r;
680 }
30b2c336
LP
681 }
682
3400bc86 683 r = export_legacy_dbus_address(handle, rt);
00efd498
ZJS
684 if (r != PAM_SUCCESS)
685 return r;
686
f9c1f4e1
LP
687 r = apply_user_record_settings(handle, ur, debug);
688 if (r != PAM_SUCCESS)
689 return r;
690
ffcfcb6b 691 return PAM_SUCCESS;
8c6db833
LP
692 }
693
ffcfcb6b 694 /* Otherwise, we ask logind to create a session for us */
8c6db833 695
1798f5af
LP
696 (void) pam_get_item(handle, PAM_XDISPLAY, (const void**) &display);
697 (void) pam_get_item(handle, PAM_TTY, (const void**) &tty);
698 (void) pam_get_item(handle, PAM_RUSER, (const void**) &remote_user);
699 (void) pam_get_item(handle, PAM_RHOST, (const void**) &remote_host);
a8573ccc 700
0ecc1c9d
LP
701 seat = getenv_harder(handle, "XDG_SEAT", NULL);
702 cvtnr = getenv_harder(handle, "XDG_VTNR", NULL);
703 type = getenv_harder(handle, "XDG_SESSION_TYPE", type_pam);
704 class = getenv_harder(handle, "XDG_SESSION_CLASS", class_pam);
f5cb2820 705 desktop = getenv_harder(handle, "XDG_SESSION_DESKTOP", desktop_pam);
a4cd87e9 706
ed18b08b 707 tty = strempty(tty);
98a28fef 708
ee8545b0 709 if (strchr(tty, ':')) {
3a736949
LP
710 /* A tty with a colon is usually an X11 display, placed there to show up in utmp. We rearrange things
711 * and don't pretend that an X display was a tty. */
ee8545b0
LP
712 if (isempty(display))
713 display = tty;
a4cd87e9 714 tty = NULL;
3a736949 715
1a4459d6 716 } else if (streq(tty, "cron")) {
3a736949
LP
717 /* cron is setting PAM_TTY to "cron" for some reason (the commit carries no information why, but
718 * probably because it wants to set it to something as pam_time/pam_access/… require PAM_TTY to be set
719 * (as they otherwise even try to update it!) — but cron doesn't actually allocate a TTY for its forked
720 * off processes.) */
0ad1271f 721 type = "unspecified";
49ebd11f 722 class = "background";
a4cd87e9 723 tty = NULL;
3a736949 724
0ad1271f 725 } else if (streq(tty, "ssh")) {
3a736949
LP
726 /* ssh has been setting PAM_TTY to "ssh" (for the same reason as cron does this, see above. For further
727 * details look for "PAM_TTY_KLUDGE" in the openssh sources). */
0ad1271f 728 type ="tty";
49ebd11f 729 class = "user";
3a736949
LP
730 tty = NULL; /* This one is particularly sad, as this means that ssh sessions — even though usually
731 * associated with a pty — won't be tracked by their tty in logind. This is because ssh
732 * does the PAM session registration early for new connections, and registers a pty only
733 * much later (this is because it doesn't know yet if it needs one at all, as whether to
734 * register a pty or not is negotiated much later in the protocol). */
735
c9ed61e7
LP
736 } else
737 /* Chop off leading /dev prefix that some clients specify, but others do not. */
738 tty = skip_dev_prefix(tty);
ee8545b0 739
8e7705e5 740 /* If this fails vtnr will be 0, that's intended */
4d6d6518 741 if (!isempty(cvtnr))
2ae4842b 742 (void) safe_atou32(cvtnr, &vtnr);
4d6d6518 743
92bd5ff3 744 if (!isempty(display) && !vtnr) {
fc7985ed 745 if (isempty(seat))
d487e2d6 746 (void) get_seat_from_display(display, &seat, &vtnr);
fc7985ed 747 else if (streq(seat, "seat0"))
d487e2d6 748 (void) get_seat_from_display(display, NULL, &vtnr);
fc7985ed 749 }
4d6d6518 750
49ebd11f 751 if (seat && !streq(seat, "seat0") && vtnr != 0) {
2675747f
LP
752 if (debug)
753 pam_syslog(handle, LOG_DEBUG, "Ignoring vtnr %"PRIu32" for %s which is not seat0", vtnr, seat);
d7353ef6
MM
754 vtnr = 0;
755 }
756
49ebd11f 757 if (isempty(type))
0ad1271f 758 type = !isempty(display) ? "x11" :
49ebd11f 759 !isempty(tty) ? "tty" : "unspecified";
98a28fef 760
55efac6c 761 if (isempty(class))
e2acb67b 762 class = streq(type, "unspecified") ? "background" : "user";
55efac6c 763
fecc80c1 764 remote = !isempty(remote_host) && !is_localhost(remote_host);
98a28fef 765
22f93314
JS
766 (void) pam_get_data(handle, "systemd.memory_max", (const void **)&memory_max);
767 (void) pam_get_data(handle, "systemd.tasks_max", (const void **)&tasks_max);
768 (void) pam_get_data(handle, "systemd.cpu_weight", (const void **)&cpu_weight);
769 (void) pam_get_data(handle, "systemd.io_weight", (const void **)&io_weight);
adc09af2 770 (void) pam_get_data(handle, "systemd.runtime_max_sec", (const void **)&runtime_max_sec);
22f93314 771
4d49b48c 772 /* Talk to logind over the message bus */
5a330cda 773
355c9966
LP
774 r = pam_acquire_bus_connection(handle, &bus);
775 if (r != PAM_SUCCESS)
776 return r;
cc377381 777
22f93314 778 if (debug) {
ce959314 779 pam_syslog(handle, LOG_DEBUG, "Asking logind to create session: "
1fa2f38f 780 "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",
9ab0d3eb 781 ur->uid, getpid_cached(),
baae0358 782 strempty(service),
cda7ecb0 783 type, class, strempty(desktop),
a4cd87e9 784 strempty(seat), vtnr, strempty(tty), strempty(display),
baae0358 785 yes_no(remote), strempty(remote_user), strempty(remote_host));
22f93314 786 pam_syslog(handle, LOG_DEBUG, "Session limits: "
adc09af2
PW
787 "memory_max=%s tasks_max=%s cpu_weight=%s io_weight=%s runtime_max_sec=%s",
788 strna(memory_max), strna(tasks_max), strna(cpu_weight), strna(io_weight), strna(runtime_max_sec));
22f93314
JS
789 }
790
5d990cc5 791 r = bus_message_new_method_call(bus, &m, bus_login_mgr, "CreateSession");
d750dde2
LP
792 if (r < 0)
793 return pam_bus_log_create_error(handle, r);
22f93314
JS
794
795 r = sd_bus_message_append(m, "uusssssussbss",
9ab0d3eb 796 (uint32_t) ur->uid,
da0da5ec 797 0,
22f93314
JS
798 service,
799 type,
800 class,
801 desktop,
802 seat,
803 vtnr,
804 tty,
805 display,
806 remote,
807 remote_user,
808 remote_host);
d750dde2
LP
809 if (r < 0)
810 return pam_bus_log_create_error(handle, r);
22f93314
JS
811
812 r = sd_bus_message_open_container(m, 'a', "(sv)");
d750dde2
LP
813 if (r < 0)
814 return pam_bus_log_create_error(handle, r);
22f93314
JS
815
816 r = append_session_memory_max(handle, m, memory_max);
7bfbf6cc
LP
817 if (r != PAM_SUCCESS)
818 return r;
22f93314 819
adc09af2 820 r = append_session_runtime_max_sec(handle, m, runtime_max_sec);
7bfbf6cc
LP
821 if (r != PAM_SUCCESS)
822 return r;
adc09af2 823
22f93314 824 r = append_session_tasks_max(handle, m, tasks_max);
7bfbf6cc
LP
825 if (r != PAM_SUCCESS)
826 return r;
22f93314
JS
827
828 r = append_session_cg_weight(handle, m, cpu_weight, "CPUWeight");
7bfbf6cc
LP
829 if (r != PAM_SUCCESS)
830 return r;
22f93314
JS
831
832 r = append_session_cg_weight(handle, m, io_weight, "IOWeight");
7bfbf6cc
LP
833 if (r != PAM_SUCCESS)
834 return r;
22f93314
JS
835
836 r = sd_bus_message_close_container(m);
d750dde2
LP
837 if (r < 0)
838 return pam_bus_log_create_error(handle, r);
ce959314 839
fbcb6300 840 r = sd_bus_call(bus, m, LOGIN_SLOW_BUS_CALL_TIMEOUT_USEC, &error, &reply);
ffcfcb6b 841 if (r < 0) {
b80120c4 842 if (sd_bus_error_has_name(&error, BUS_ERROR_SESSION_BUSY)) {
2675747f 843 if (debug)
c7e93c4d 844 pam_syslog(handle, LOG_DEBUG, "Not creating session: %s", bus_error_message(&error, r));
b80120c4
DH
845 return PAM_SUCCESS;
846 } else {
847 pam_syslog(handle, LOG_ERR, "Failed to create session: %s", bus_error_message(&error, r));
8d46418e 848 return PAM_SESSION_ERR;
b80120c4 849 }
98a28fef 850 }
74fe1fe3 851
ffcfcb6b 852 r = sd_bus_message_read(reply,
baae0358 853 "soshusub",
ffcfcb6b
ZJS
854 &id,
855 &object_path,
856 &runtime_path,
857 &session_fd,
baae0358 858 &original_uid,
ffcfcb6b
ZJS
859 &seat,
860 &vtnr,
861 &existing);
d750dde2
LP
862 if (r < 0)
863 return pam_bus_log_parse_error(handle, r);
74fe1fe3 864
ce959314
MS
865 if (debug)
866 pam_syslog(handle, LOG_DEBUG, "Reply from logind: "
baae0358
LP
867 "id=%s object_path=%s runtime_path=%s session_fd=%d seat=%s vtnr=%u original_uid=%u",
868 id, object_path, runtime_path, session_fd, seat, vtnr, original_uid);
ce959314 869
d6baaa69
LP
870 r = update_environment(handle, "XDG_SESSION_ID", id);
871 if (r != PAM_SUCCESS)
5a330cda 872 return r;
8c6db833 873
9ab0d3eb 874 if (original_uid == ur->uid) {
baae0358
LP
875 /* Don't set $XDG_RUNTIME_DIR if the user we now
876 * authenticated for does not match the original user
877 * of the session. We do this in order not to result
878 * in privileged apps clobbering the runtime directory
879 * unnecessarily. */
880
9ab0d3eb 881 if (validate_runtime_directory(handle, runtime_path, ur->uid)) {
b9217112
LP
882 r = update_environment(handle, "XDG_RUNTIME_DIR", runtime_path);
883 if (r != PAM_SUCCESS)
884 return r;
885 }
00efd498 886
3400bc86 887 r = export_legacy_dbus_address(handle, runtime_path);
00efd498
ZJS
888 if (r != PAM_SUCCESS)
889 return r;
98a28fef 890 }
8c6db833 891
b2f74f07
LP
892 /* Most likely we got the session/type/class from environment variables, but might have gotten the data
893 * somewhere else (for example PAM module parameters). Let's now update the environment variables, so that this
894 * data is inherited into the session processes, and programs can rely on them to be initialized. */
895
896 r = update_environment(handle, "XDG_SESSION_TYPE", type);
897 if (r != PAM_SUCCESS)
898 return r;
899
900 r = update_environment(handle, "XDG_SESSION_CLASS", class);
901 if (r != PAM_SUCCESS)
902 return r;
903
904 r = update_environment(handle, "XDG_SESSION_DESKTOP", desktop);
905 if (r != PAM_SUCCESS)
906 return r;
907
d6baaa69
LP
908 r = update_environment(handle, "XDG_SEAT", seat);
909 if (r != PAM_SUCCESS)
910 return r;
bbc73283
LP
911
912 if (vtnr > 0) {
29d230f6 913 char buf[DECIMAL_STR_MAX(vtnr)];
baae0358 914 sprintf(buf, "%u", vtnr);
bbc73283 915
d6baaa69
LP
916 r = update_environment(handle, "XDG_VTNR", buf);
917 if (r != PAM_SUCCESS)
5a330cda 918 return r;
bbc73283
LP
919 }
920
77085881
LP
921 r = pam_set_data(handle, "systemd.existing", INT_TO_PTR(!!existing), NULL);
922 if (r != PAM_SUCCESS) {
d9608d40 923 pam_syslog(handle, LOG_ERR, "Failed to install existing flag: %s", pam_strerror(handle, r));
5a330cda 924 return r;
77085881
LP
925 }
926
21c390cc 927 if (session_fd >= 0) {
85c08dc0 928 session_fd = fcntl(session_fd, F_DUPFD_CLOEXEC, 3);
5a330cda
ZJS
929 if (session_fd < 0) {
930 pam_syslog(handle, LOG_ERR, "Failed to dup session fd: %m");
931 return PAM_SESSION_ERR;
932 }
933
23e096cc 934 r = pam_set_data(handle, "systemd.session-fd", FD_TO_PTR(session_fd), NULL);
21c390cc 935 if (r != PAM_SUCCESS) {
d9608d40 936 pam_syslog(handle, LOG_ERR, "Failed to install session fd: %s", pam_strerror(handle, r));
03e334a1 937 safe_close(session_fd);
5a330cda 938 return r;
21c390cc 939 }
98a28fef 940 }
8c6db833 941
f9c1f4e1
LP
942 r = apply_user_record_settings(handle, ur, debug);
943 if (r != PAM_SUCCESS)
944 return r;
945
355c9966 946 /* Let's release the D-Bus connection, after all the session might live quite a long time, and we are
f9c1f4e1
LP
947 * not going to use the bus connection in that time, so let's better close before the daemon kicks us
948 * off because we are not processing anything. */
355c9966 949 (void) pam_release_bus_connection(handle);
ffcfcb6b 950 return PAM_SUCCESS;
98a28fef 951}
8c6db833 952
98a28fef
LP
953_public_ PAM_EXTERN int pam_sm_close_session(
954 pam_handle_t *handle,
955 int flags,
956 int argc, const char **argv) {
8c6db833 957
5f41d1f1 958 const void *existing = NULL;
45c5fa25 959 bool debug = false;
75c8e3cf 960 const char *id;
75c8e3cf 961 int r;
8c6db833 962
ffcfcb6b 963 assert(handle);
75c8e3cf 964
45c5fa25
LP
965 if (parse_argv(handle,
966 argc, argv,
967 NULL,
968 NULL,
969 NULL,
970 &debug) < 0)
971 return PAM_SESSION_ERR;
972
973 if (debug)
974 pam_syslog(handle, LOG_DEBUG, "pam-systemd shutting down");
975
77085881
LP
976 /* Only release session if it wasn't pre-existing when we
977 * tried to create it */
d487e2d6 978 (void) pam_get_data(handle, "systemd.existing", &existing);
77085881 979
75c8e3cf 980 id = pam_getenv(handle, "XDG_SESSION_ID");
77085881 981 if (id && !existing) {
355c9966
LP
982 _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
983 _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
75c8e3cf 984
355c9966
LP
985 /* Before we go and close the FIFO we need to tell logind that this is a clean session
986 * shutdown, so that it doesn't just go and slaughter us immediately after closing the fd */
75c8e3cf 987
355c9966
LP
988 r = pam_acquire_bus_connection(handle, &bus);
989 if (r != PAM_SUCCESS)
990 return r;
75c8e3cf 991
5d990cc5 992 r = bus_call_method(bus, bus_login_mgr, "ReleaseSession", &error, NULL, "s", id);
ffcfcb6b 993 if (r < 0) {
5f41d1f1
LP
994 pam_syslog(handle, LOG_ERR, "Failed to release session: %s", bus_error_message(&error, r));
995 return PAM_SESSION_ERR;
75c8e3cf
LP
996 }
997 }
998
355c9966
LP
999 /* Note that we are knowingly leaking the FIFO fd here. This way, logind can watch us die. If we
1000 * closed it here it would not have any clue when that is completed. Given that one cannot really
1001 * have multiple PAM sessions open from the same process this means we will leak one FD at max. */
75c8e3cf 1002
5f41d1f1 1003 return PAM_SUCCESS;
8c6db833 1004}