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d6c9574f | 1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
8c6db833 LP |
2 | |
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2010 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
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 | General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
22 | #include <errno.h> | |
23 | #include <fcntl.h> | |
24 | #include <sys/file.h> | |
25 | #include <pwd.h> | |
a838e6a1 | 26 | #include <endian.h> |
ac123445 | 27 | #include <sys/capability.h> |
8c6db833 LP |
28 | |
29 | #include <security/pam_modules.h> | |
30 | #include <security/_pam_macros.h> | |
31 | #include <security/pam_modutil.h> | |
32 | #include <security/pam_ext.h> | |
33 | #include <security/pam_misc.h> | |
34 | ||
8c6db833 LP |
35 | #include "util.h" |
36 | #include "cgroup-util.h" | |
37 | #include "macro.h" | |
38 | #include "sd-daemon.h" | |
74fe1fe3 | 39 | #include "strv.h" |
8c6db833 LP |
40 | |
41 | static int parse_argv(pam_handle_t *handle, | |
42 | int argc, const char **argv, | |
43 | bool *create_session, | |
44 | bool *kill_session, | |
74fe1fe3 | 45 | bool *kill_user, |
b20c6be6 | 46 | char ***controllers, |
e9fbc77c LP |
47 | char ***reset_controllers, |
48 | char ***kill_only_users, | |
49 | char ***kill_exclude_users) { | |
8c6db833 LP |
50 | |
51 | unsigned i; | |
b20c6be6 | 52 | bool reset_controller_set = false; |
e9fbc77c | 53 | bool kill_exclude_users_set = false; |
8c6db833 LP |
54 | |
55 | assert(argc >= 0); | |
56 | assert(argc == 0 || argv); | |
57 | ||
58 | for (i = 0; i < (unsigned) argc; i++) { | |
59 | int k; | |
60 | ||
61 | if (startswith(argv[i], "create-session=")) { | |
62 | if ((k = parse_boolean(argv[i] + 15)) < 0) { | |
63 | pam_syslog(handle, LOG_ERR, "Failed to parse create-session= argument."); | |
64 | return k; | |
65 | } | |
66 | ||
67 | if (create_session) | |
68 | *create_session = k; | |
74fe1fe3 | 69 | |
8c6db833 LP |
70 | } else if (startswith(argv[i], "kill-session=")) { |
71 | if ((k = parse_boolean(argv[i] + 13)) < 0) { | |
72 | pam_syslog(handle, LOG_ERR, "Failed to parse kill-session= argument."); | |
73 | return k; | |
74 | } | |
75 | ||
76 | if (kill_session) | |
77 | *kill_session = k; | |
78 | ||
79 | } else if (startswith(argv[i], "kill-user=")) { | |
80 | if ((k = parse_boolean(argv[i] + 10)) < 0) { | |
81 | pam_syslog(handle, LOG_ERR, "Failed to parse kill-user= argument."); | |
82 | return k; | |
83 | } | |
84 | ||
85 | if (kill_user) | |
86 | *kill_user = k; | |
74fe1fe3 LP |
87 | |
88 | } else if (startswith(argv[i], "controllers=")) { | |
89 | ||
90 | if (controllers) { | |
91 | char **l; | |
92 | ||
93 | if (!(l = strv_split(argv[i] + 12, ","))) { | |
94 | pam_syslog(handle, LOG_ERR, "Out of memory."); | |
95 | return -ENOMEM; | |
96 | } | |
97 | ||
98 | strv_free(*controllers); | |
99 | *controllers = l; | |
100 | } | |
101 | ||
b20c6be6 LP |
102 | } else if (startswith(argv[i], "reset-controllers=")) { |
103 | ||
104 | if (reset_controllers) { | |
105 | char **l; | |
106 | ||
107 | if (!(l = strv_split(argv[i] + 18, ","))) { | |
108 | pam_syslog(handle, LOG_ERR, "Out of memory."); | |
109 | return -ENOMEM; | |
110 | } | |
111 | ||
112 | strv_free(*reset_controllers); | |
113 | *reset_controllers = l; | |
114 | } | |
115 | ||
116 | reset_controller_set = true; | |
74fe1fe3 | 117 | |
e9fbc77c LP |
118 | } else if (startswith(argv[i], "kill-only-users=")) { |
119 | ||
120 | if (kill_only_users) { | |
121 | char **l; | |
122 | ||
123 | if (!(l = strv_split(argv[i] + 16, ","))) { | |
124 | pam_syslog(handle, LOG_ERR, "Out of memory."); | |
125 | return -ENOMEM; | |
126 | } | |
127 | ||
128 | strv_free(*kill_only_users); | |
129 | *kill_only_users = l; | |
130 | } | |
131 | ||
132 | } else if (startswith(argv[i], "kill-exclude-users=")) { | |
133 | ||
134 | if (kill_exclude_users) { | |
135 | char **l; | |
136 | ||
137 | if (!(l = strv_split(argv[i] + 19, ","))) { | |
138 | pam_syslog(handle, LOG_ERR, "Out of memory."); | |
139 | return -ENOMEM; | |
140 | } | |
141 | ||
142 | strv_free(*kill_exclude_users); | |
143 | *kill_exclude_users = l; | |
144 | } | |
145 | ||
146 | kill_exclude_users_set = true; | |
147 | ||
8c6db833 LP |
148 | } else { |
149 | pam_syslog(handle, LOG_ERR, "Unknown parameter '%s'.", argv[i]); | |
150 | return -EINVAL; | |
151 | } | |
152 | } | |
153 | ||
b20c6be6 | 154 | if (!reset_controller_set && reset_controllers) { |
74fe1fe3 LP |
155 | char **l; |
156 | ||
157 | if (!(l = strv_new("cpu", NULL))) { | |
158 | pam_syslog(handle, LOG_ERR, "Out of memory"); | |
159 | return -ENOMEM; | |
160 | } | |
161 | ||
b20c6be6 | 162 | *reset_controllers = l; |
74fe1fe3 LP |
163 | } |
164 | ||
165 | if (controllers) | |
166 | strv_remove(*controllers, "name=systemd"); | |
167 | ||
b20c6be6 LP |
168 | if (reset_controllers) |
169 | strv_remove(*reset_controllers, "name=systemd"); | |
170 | ||
8c6db833 LP |
171 | if (kill_session && *kill_session && kill_user) |
172 | *kill_user = true; | |
173 | ||
e9fbc77c LP |
174 | if (!kill_exclude_users_set && kill_exclude_users) { |
175 | char **l; | |
176 | ||
177 | if (!(l = strv_new("root", NULL))) { | |
178 | pam_syslog(handle, LOG_ERR, "Out of memory"); | |
179 | return -ENOMEM; | |
180 | } | |
181 | ||
182 | *kill_exclude_users = l; | |
183 | } | |
184 | ||
8c6db833 LP |
185 | return 0; |
186 | } | |
187 | ||
188 | static int open_file_and_lock(const char *fn) { | |
189 | int fd; | |
190 | ||
191 | assert(fn); | |
192 | ||
193 | if ((fd = open(fn, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW|O_CREAT, 0600)) < 0) | |
194 | return -errno; | |
195 | ||
2e225d65 LP |
196 | /* The BSD socket semantics are a lot nicer than those of |
197 | * POSIX locks. Which is why we use flock() here. BSD locking | |
198 | * does not work across NFS which however is not needed here | |
199 | * as the filesystems in question should be local, and only | |
200 | * locally accessible, and most likely even tmpfs. */ | |
201 | ||
90102b22 | 202 | if (flock(fd, LOCK_EX) < 0) { |
90102b22 | 203 | close_nointr_nofail(fd); |
1f73f0f1 | 204 | return -errno; |
90102b22 | 205 | } |
8c6db833 LP |
206 | |
207 | return fd; | |
208 | } | |
209 | ||
2e225d65 LP |
210 | enum { |
211 | SESSION_ID_AUDIT = 'a', | |
212 | SESSION_ID_COUNTER = 'c', | |
213 | SESSION_ID_RANDOM = 'r' | |
214 | }; | |
215 | ||
216 | static uint64_t get_session_id(int *mode) { | |
a838e6a1 LP |
217 | char *s; |
218 | int fd; | |
8c6db833 | 219 | |
2e225d65 LP |
220 | assert(mode); |
221 | ||
a838e6a1 LP |
222 | /* First attempt: let's use the session ID of the audit |
223 | * system, if it is available. */ | |
81481c99 LP |
224 | if (have_effective_cap(CAP_AUDIT_CONTROL) > 0) |
225 | if (read_one_line_file("/proc/self/sessionid", &s) >= 0) { | |
226 | uint32_t u; | |
227 | int r; | |
8c6db833 | 228 | |
81481c99 LP |
229 | r = safe_atou32(s, &u); |
230 | free(s); | |
8c6db833 | 231 | |
81481c99 LP |
232 | if (r >= 0 && u != (uint32_t) -1 && u > 0) { |
233 | *mode = SESSION_ID_AUDIT; | |
234 | return (uint64_t) u; | |
235 | } | |
2e225d65 | 236 | } |
8c6db833 | 237 | |
a838e6a1 LP |
238 | /* Second attempt, use our own counter. */ |
239 | if ((fd = open_file_and_lock(RUNTIME_DIR "/user/.pam-systemd-session")) >= 0) { | |
240 | uint64_t counter; | |
241 | ssize_t r; | |
8c6db833 | 242 | |
a838e6a1 | 243 | /* We do a bit of endianess swapping here, just to be |
bb29785e LP |
244 | * sure. /run should be machine specific anyway, and |
245 | * even mounted from tmpfs, so this byteswapping | |
246 | * should really not be necessary. But then again, you | |
247 | * never know, so let's avoid any risk. */ | |
8c6db833 | 248 | |
a838e6a1 LP |
249 | if (loop_read(fd, &counter, sizeof(counter), false) != sizeof(counter)) |
250 | counter = 1; | |
251 | else | |
252 | counter = le64toh(counter) + 1; | |
8c6db833 | 253 | |
a838e6a1 LP |
254 | if (lseek(fd, 0, SEEK_SET) == 0) { |
255 | uint64_t swapped = htole64(counter); | |
256 | ||
257 | r = loop_write(fd, &swapped, sizeof(swapped), false); | |
258 | ||
259 | if (r != sizeof(swapped)) | |
260 | r = -EIO; | |
261 | } else | |
262 | r = -errno; | |
8c6db833 | 263 | |
a838e6a1 LP |
264 | close_nointr_nofail(fd); |
265 | ||
2e225d65 LP |
266 | if (r >= 0) { |
267 | *mode = SESSION_ID_COUNTER; | |
a838e6a1 | 268 | return counter; |
2e225d65 | 269 | } |
a838e6a1 LP |
270 | } |
271 | ||
2e225d65 LP |
272 | *mode = SESSION_ID_RANDOM; |
273 | ||
a838e6a1 LP |
274 | /* Last attempt, pick a random value */ |
275 | return (uint64_t) random_ull(); | |
276 | } | |
1f73f0f1 | 277 | |
8c6db833 LP |
278 | static int get_user_data( |
279 | pam_handle_t *handle, | |
280 | const char **ret_username, | |
281 | struct passwd **ret_pw) { | |
282 | ||
d90b9d27 LP |
283 | const char *username = NULL; |
284 | struct passwd *pw = NULL; | |
8c6db833 | 285 | int r; |
d90b9d27 LP |
286 | bool have_loginuid = false; |
287 | char *s; | |
8c6db833 LP |
288 | |
289 | assert(handle); | |
290 | assert(ret_username); | |
291 | assert(ret_pw); | |
292 | ||
81481c99 | 293 | if (have_effective_cap(CAP_AUDIT_CONTROL) > 0) { |
ac123445 LP |
294 | /* Only use audit login uid if we are executed with |
295 | * sufficient capabilities so that pam_loginuid could | |
296 | * do its job. If we are lacking the CAP_AUDIT_CONTROL | |
297 | * capabality we most likely are being run in a | |
298 | * container and /proc/self/loginuid is useless since | |
299 | * it probably contains a uid of the host system. */ | |
d90b9d27 | 300 | |
ac123445 LP |
301 | if (read_one_line_file("/proc/self/loginuid", &s) >= 0) { |
302 | uint32_t u; | |
d90b9d27 | 303 | |
ac123445 LP |
304 | r = safe_atou32(s, &u); |
305 | free(s); | |
306 | ||
307 | if (r >= 0 && u != (uint32_t) -1 && u > 0) { | |
308 | have_loginuid = true; | |
309 | pw = pam_modutil_getpwuid(handle, u); | |
310 | } | |
d90b9d27 | 311 | } |
8c6db833 LP |
312 | } |
313 | ||
d90b9d27 LP |
314 | if (!have_loginuid) { |
315 | if ((r = pam_get_user(handle, &username, NULL)) != PAM_SUCCESS) { | |
316 | pam_syslog(handle, LOG_ERR, "Failed to get user name."); | |
317 | return r; | |
318 | } | |
319 | ||
320 | if (!username || !*username) { | |
321 | pam_syslog(handle, LOG_ERR, "User name not valid."); | |
322 | return PAM_AUTH_ERR; | |
323 | } | |
324 | ||
325 | pw = pam_modutil_getpwnam(handle, username); | |
8c6db833 LP |
326 | } |
327 | ||
d90b9d27 | 328 | if (!pw) { |
8c6db833 LP |
329 | pam_syslog(handle, LOG_ERR, "Failed to get user data."); |
330 | return PAM_USER_UNKNOWN; | |
331 | } | |
332 | ||
333 | *ret_pw = pw; | |
d90b9d27 | 334 | *ret_username = username ? username : pw->pw_name; |
8c6db833 LP |
335 | |
336 | return PAM_SUCCESS; | |
337 | } | |
338 | ||
74fe1fe3 LP |
339 | static int create_user_group( |
340 | pam_handle_t *handle, | |
341 | const char *controller, | |
342 | const char *group, | |
343 | struct passwd *pw, | |
344 | bool attach, | |
345 | bool remember) { | |
346 | ||
8c6db833 LP |
347 | int r; |
348 | ||
349 | assert(handle); | |
350 | assert(group); | |
351 | ||
352 | if (attach) | |
74fe1fe3 | 353 | r = cg_create_and_attach(controller, group, 0); |
8c6db833 | 354 | else |
74fe1fe3 | 355 | r = cg_create(controller, group); |
8c6db833 LP |
356 | |
357 | if (r < 0) { | |
358 | pam_syslog(handle, LOG_ERR, "Failed to create cgroup: %s", strerror(-r)); | |
359 | return PAM_SESSION_ERR; | |
360 | } | |
361 | ||
672c48cc LP |
362 | if (r > 0 && remember) { |
363 | /* Remember that it was us who created this group, and | |
364 | * that hence we need to remove it too. This is a | |
365 | * protection against removing the cgroup when run | |
366 | * recursively. */ | |
367 | if ((r = pam_set_data(handle, "systemd.created", INT_TO_PTR(1), NULL)) != PAM_SUCCESS) { | |
368 | pam_syslog(handle, LOG_ERR, "Failed to install created variable."); | |
369 | return r; | |
370 | } | |
371 | } | |
372 | ||
74fe1fe3 LP |
373 | if ((r = cg_set_task_access(controller, group, 0644, pw->pw_uid, pw->pw_gid)) < 0 || |
374 | (r = cg_set_group_access(controller, group, 0755, pw->pw_uid, pw->pw_gid)) < 0) { | |
8c6db833 LP |
375 | pam_syslog(handle, LOG_ERR, "Failed to change access modes: %s", strerror(-r)); |
376 | return PAM_SESSION_ERR; | |
377 | } | |
378 | ||
379 | return PAM_SUCCESS; | |
380 | } | |
381 | ||
b20c6be6 LP |
382 | static int reset_group( |
383 | pam_handle_t *handle, | |
384 | const char *controller) { | |
385 | ||
386 | int r; | |
387 | ||
388 | assert(handle); | |
389 | ||
390 | if ((r = cg_attach(controller, "/", 0)) < 0) { | |
391 | pam_syslog(handle, LOG_ERR, "Failed to reset cgroup for controller %s: %s", controller, strerror(-r)); | |
392 | return PAM_SESSION_ERR; | |
393 | } | |
394 | ||
395 | return PAM_SUCCESS; | |
396 | } | |
397 | ||
8c6db833 LP |
398 | _public_ PAM_EXTERN int pam_sm_open_session( |
399 | pam_handle_t *handle, | |
400 | int flags, | |
401 | int argc, const char **argv) { | |
402 | ||
403 | const char *username = NULL; | |
404 | struct passwd *pw; | |
405 | int r; | |
406 | char *buf = NULL; | |
407 | int lock_fd = -1; | |
408 | bool create_session = true; | |
b20c6be6 | 409 | char **controllers = NULL, **reset_controllers = NULL, **c; |
1f73f0f1 | 410 | char *cgroup_user_tree = NULL; |
8c6db833 LP |
411 | |
412 | assert(handle); | |
413 | ||
672c48cc | 414 | /* pam_syslog(handle, LOG_DEBUG, "pam-systemd initializing"); */ |
8c6db833 | 415 | |
8c6db833 LP |
416 | /* Make this a NOP on non-systemd systems */ |
417 | if (sd_booted() <= 0) | |
418 | return PAM_SUCCESS; | |
419 | ||
e9fbc77c LP |
420 | if (parse_argv(handle, |
421 | argc, argv, | |
422 | &create_session, NULL, NULL, | |
423 | &controllers, &reset_controllers, | |
424 | NULL, NULL) < 0) | |
74fe1fe3 LP |
425 | return PAM_SESSION_ERR; |
426 | ||
8c6db833 LP |
427 | if ((r = get_user_data(handle, &username, &pw)) != PAM_SUCCESS) |
428 | goto finish; | |
429 | ||
1f73f0f1 LP |
430 | if ((r = cg_get_user_path(&cgroup_user_tree)) < 0) { |
431 | pam_syslog(handle, LOG_ERR, "Failed to determine user cgroup tree: %s", strerror(-r)); | |
432 | r = PAM_SYSTEM_ERR; | |
433 | goto finish; | |
434 | } | |
435 | ||
8c6db833 LP |
436 | if (safe_mkdir(RUNTIME_DIR "/user", 0755, 0, 0) < 0) { |
437 | pam_syslog(handle, LOG_ERR, "Failed to create runtime directory: %m"); | |
438 | r = PAM_SYSTEM_ERR; | |
439 | goto finish; | |
440 | } | |
441 | ||
442 | if ((lock_fd = open_file_and_lock(RUNTIME_DIR "/user/.pam-systemd-lock")) < 0) { | |
443 | pam_syslog(handle, LOG_ERR, "Failed to lock runtime directory: %m"); | |
444 | r = PAM_SYSTEM_ERR; | |
445 | goto finish; | |
446 | } | |
447 | ||
bb29785e | 448 | /* Create /run/user/$USER */ |
8c6db833 LP |
449 | free(buf); |
450 | if (asprintf(&buf, RUNTIME_DIR "/user/%s", username) < 0) { | |
451 | r = PAM_BUF_ERR; | |
452 | goto finish; | |
453 | } | |
454 | ||
455 | if (safe_mkdir(buf, 0700, pw->pw_uid, pw->pw_gid) < 0) { | |
456 | pam_syslog(handle, LOG_WARNING, "Failed to create runtime directory: %m"); | |
457 | r = PAM_SYSTEM_ERR; | |
458 | goto finish; | |
459 | } else if ((r = pam_misc_setenv(handle, "XDG_RUNTIME_DIR", buf, 0)) != PAM_SUCCESS) { | |
460 | pam_syslog(handle, LOG_ERR, "Failed to set runtime dir."); | |
461 | goto finish; | |
462 | } | |
463 | ||
464 | free(buf); | |
465 | buf = NULL; | |
466 | ||
467 | if (create_session) { | |
a838e6a1 | 468 | const char *id; |
8c6db833 LP |
469 | |
470 | /* Reuse or create XDG session ID */ | |
a838e6a1 | 471 | if (!(id = pam_getenv(handle, "XDG_SESSION_ID"))) { |
2e225d65 | 472 | int mode; |
a838e6a1 | 473 | |
2e225d65 | 474 | if (asprintf(&buf, "%llux", (unsigned long long) get_session_id(&mode)) < 0) { |
8c6db833 LP |
475 | r = PAM_BUF_ERR; |
476 | goto finish; | |
477 | } | |
478 | ||
2e225d65 LP |
479 | /* To avoid id clashes we add the session id |
480 | * source to our session ids. Note that the | |
481 | * session id source might change during | |
482 | * runtime, because a filesystem became | |
483 | * writable or the system reconfigured. */ | |
484 | buf[strlen(buf)-1] = | |
485 | mode != SESSION_ID_AUDIT ? (char) mode : 0; | |
486 | ||
a838e6a1 LP |
487 | if ((r = pam_misc_setenv(handle, "XDG_SESSION_ID", buf, 0)) != PAM_SUCCESS) { |
488 | pam_syslog(handle, LOG_ERR, "Failed to set session id."); | |
8c6db833 LP |
489 | goto finish; |
490 | } | |
491 | ||
a838e6a1 LP |
492 | if (!(id = pam_getenv(handle, "XDG_SESSION_ID"))) { |
493 | pam_syslog(handle, LOG_ERR, "Failed to get session id."); | |
8c6db833 LP |
494 | r = PAM_SESSION_ERR; |
495 | goto finish; | |
496 | } | |
497 | } | |
498 | ||
1f73f0f1 | 499 | r = asprintf(&buf, "%s/%s/%s", cgroup_user_tree, username, id); |
8c6db833 | 500 | } else |
1f73f0f1 | 501 | r = asprintf(&buf, "%s/%s/master", cgroup_user_tree, username); |
8c6db833 LP |
502 | |
503 | if (r < 0) { | |
504 | r = PAM_BUF_ERR; | |
505 | goto finish; | |
506 | } | |
507 | ||
672c48cc LP |
508 | pam_syslog(handle, LOG_INFO, "Moving new user session for %s into control group %s.", username, buf); |
509 | ||
74fe1fe3 | 510 | if ((r = create_user_group(handle, SYSTEMD_CGROUP_CONTROLLER, buf, pw, true, true)) != PAM_SUCCESS) |
8c6db833 LP |
511 | goto finish; |
512 | ||
74fe1fe3 LP |
513 | /* The additional controllers don't really matter, so we |
514 | * ignore the return value */ | |
515 | STRV_FOREACH(c, controllers) | |
516 | create_user_group(handle, *c, buf, pw, true, false); | |
517 | ||
b20c6be6 LP |
518 | STRV_FOREACH(c, reset_controllers) |
519 | reset_group(handle, *c); | |
520 | ||
8c6db833 LP |
521 | r = PAM_SUCCESS; |
522 | ||
523 | finish: | |
524 | free(buf); | |
525 | ||
526 | if (lock_fd >= 0) | |
527 | close_nointr_nofail(lock_fd); | |
528 | ||
74fe1fe3 | 529 | strv_free(controllers); |
b20c6be6 | 530 | strv_free(reset_controllers); |
74fe1fe3 | 531 | |
1f73f0f1 LP |
532 | free(cgroup_user_tree); |
533 | ||
8c6db833 LP |
534 | return r; |
535 | } | |
536 | ||
537 | static int session_remains(pam_handle_t *handle, const char *user_path) { | |
35d2e7ec | 538 | int r; |
8c6db833 | 539 | bool remains = false; |
35d2e7ec LP |
540 | DIR *d; |
541 | char *subgroup; | |
8c6db833 | 542 | |
35d2e7ec LP |
543 | if ((r = cg_enumerate_subgroups(SYSTEMD_CGROUP_CONTROLLER, user_path, &d)) < 0) |
544 | return r; | |
8c6db833 | 545 | |
35d2e7ec | 546 | while ((r = cg_read_subgroup(d, &subgroup)) > 0) { |
8c6db833 | 547 | |
96a8cbfa | 548 | remains = !streq(subgroup, "master"); |
35d2e7ec | 549 | free(subgroup); |
8c6db833 | 550 | |
35d2e7ec LP |
551 | if (remains) |
552 | break; | |
8c6db833 LP |
553 | } |
554 | ||
35d2e7ec | 555 | closedir(d); |
8c6db833 | 556 | |
35d2e7ec LP |
557 | if (r < 0) |
558 | return r; | |
8c6db833 | 559 | |
35d2e7ec | 560 | return !!remains; |
8c6db833 LP |
561 | } |
562 | ||
e9fbc77c LP |
563 | static bool check_user_lists( |
564 | pam_handle_t *handle, | |
565 | uid_t uid, | |
566 | char **kill_only_users, | |
567 | char **kill_exclude_users) { | |
568 | ||
569 | const char *name = NULL; | |
570 | char **l; | |
571 | ||
572 | assert(handle); | |
573 | ||
574 | if (uid == 0) | |
575 | name = "root"; /* Avoid obvious NSS requests, to suppress network traffic */ | |
576 | else { | |
577 | struct passwd *pw; | |
578 | ||
579 | if ((pw = pam_modutil_getpwuid(handle, uid))) | |
580 | name = pw->pw_name; | |
581 | } | |
582 | ||
583 | STRV_FOREACH(l, kill_exclude_users) { | |
584 | uint32_t id; | |
585 | ||
586 | if (safe_atou32(*l, &id) >= 0) | |
587 | if ((uid_t) id == uid) | |
588 | return false; | |
589 | ||
590 | if (name && streq(name, *l)) | |
591 | return false; | |
592 | } | |
593 | ||
594 | if (strv_isempty(kill_only_users)) | |
595 | return true; | |
596 | ||
597 | STRV_FOREACH(l, kill_only_users) { | |
598 | uint32_t id; | |
599 | ||
600 | if (safe_atou32(*l, &id) >= 0) | |
601 | if ((uid_t) id == uid) | |
602 | return true; | |
603 | ||
604 | if (name && streq(name, *l)) | |
605 | return true; | |
606 | } | |
607 | ||
608 | return false; | |
609 | } | |
610 | ||
8c6db833 LP |
611 | _public_ PAM_EXTERN int pam_sm_close_session( |
612 | pam_handle_t *handle, | |
613 | int flags, | |
614 | int argc, const char **argv) { | |
615 | ||
616 | const char *username = NULL; | |
617 | bool kill_session = false; | |
618 | bool kill_user = false; | |
619 | int lock_fd = -1, r; | |
620 | char *session_path = NULL, *nosession_path = NULL, *user_path = NULL; | |
a838e6a1 | 621 | const char *id; |
8c6db833 | 622 | struct passwd *pw; |
672c48cc | 623 | const void *created = NULL; |
e9fbc77c | 624 | char **controllers = NULL, **c, **kill_only_users = NULL, **kill_exclude_users = NULL; |
1f73f0f1 | 625 | char *cgroup_user_tree = NULL; |
8c6db833 LP |
626 | |
627 | assert(handle); | |
628 | ||
8c6db833 LP |
629 | /* Make this a NOP on non-systemd systems */ |
630 | if (sd_booted() <= 0) | |
631 | return PAM_SUCCESS; | |
632 | ||
e9fbc77c LP |
633 | if (parse_argv(handle, |
634 | argc, argv, | |
635 | NULL, &kill_session, &kill_user, | |
636 | &controllers, NULL, | |
637 | &kill_only_users, &kill_exclude_users) < 0) | |
74fe1fe3 LP |
638 | return PAM_SESSION_ERR; |
639 | ||
8c6db833 LP |
640 | if ((r = get_user_data(handle, &username, &pw)) != PAM_SUCCESS) |
641 | goto finish; | |
642 | ||
1f73f0f1 LP |
643 | if ((r = cg_get_user_path(&cgroup_user_tree)) < 0) { |
644 | pam_syslog(handle, LOG_ERR, "Failed to determine user cgroup tree: %s", strerror(-r)); | |
645 | r = PAM_SYSTEM_ERR; | |
646 | goto finish; | |
647 | } | |
648 | ||
8c6db833 LP |
649 | if ((lock_fd = open_file_and_lock(RUNTIME_DIR "/user/.pam-systemd-lock")) < 0) { |
650 | pam_syslog(handle, LOG_ERR, "Failed to lock runtime directory: %m"); | |
651 | r = PAM_SYSTEM_ERR; | |
652 | goto finish; | |
653 | } | |
654 | ||
824a1d59 | 655 | /* We are probably still in some session/user dir. Move ourselves out of the way as first step */ |
1f73f0f1 | 656 | if ((r = cg_attach(SYSTEMD_CGROUP_CONTROLLER, cgroup_user_tree, 0)) < 0) |
35d2e7ec LP |
657 | pam_syslog(handle, LOG_ERR, "Failed to move us away: %s", strerror(-r)); |
658 | ||
74fe1fe3 | 659 | STRV_FOREACH(c, controllers) |
1f73f0f1 | 660 | if ((r = cg_attach(*c, cgroup_user_tree, 0)) < 0) |
74fe1fe3 LP |
661 | pam_syslog(handle, LOG_ERR, "Failed to move us away in %s hierarchy: %s", *c, strerror(-r)); |
662 | ||
1f73f0f1 | 663 | if (asprintf(&user_path, "%s/%s", cgroup_user_tree, username) < 0) { |
8c6db833 LP |
664 | r = PAM_BUF_ERR; |
665 | goto finish; | |
666 | } | |
667 | ||
672c48cc LP |
668 | pam_get_data(handle, "systemd.created", &created); |
669 | ||
670 | if ((id = pam_getenv(handle, "XDG_SESSION_ID")) && created) { | |
8c6db833 | 671 | |
1f73f0f1 LP |
672 | if (asprintf(&session_path, "%s/%s/%s", cgroup_user_tree, username, id) < 0 || |
673 | asprintf(&nosession_path, "%s/%s/master", cgroup_user_tree, username) < 0) { | |
8c6db833 LP |
674 | r = PAM_BUF_ERR; |
675 | goto finish; | |
676 | } | |
677 | ||
e9fbc77c | 678 | if (kill_session && check_user_lists(handle, pw->pw_uid, kill_only_users, kill_exclude_users)) { |
672c48cc LP |
679 | pam_syslog(handle, LOG_INFO, "Killing remaining processes of user session %s of %s.", id, username); |
680 | ||
35d2e7ec LP |
681 | /* Kill processes in session cgroup, and delete it */ |
682 | if ((r = cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, session_path, true)) < 0) | |
8c6db833 | 683 | pam_syslog(handle, LOG_ERR, "Failed to kill session cgroup: %s", strerror(-r)); |
35d2e7ec | 684 | } else { |
672c48cc LP |
685 | pam_syslog(handle, LOG_INFO, "Moving remaining processes of user session %s of %s into control group %s.", id, username, nosession_path); |
686 | ||
824a1d59 LP |
687 | /* Migrate processes from session to user |
688 | * cgroup. First, try to create the user group | |
689 | * in case it doesn't exist yet. Also, delete | |
690 | * the session group. */ | |
74fe1fe3 | 691 | create_user_group(handle, SYSTEMD_CGROUP_CONTROLLER, nosession_path, pw, false, false); |
8c6db833 | 692 | |
35d2e7ec | 693 | if ((r = cg_migrate_recursive(SYSTEMD_CGROUP_CONTROLLER, session_path, nosession_path, false, true)) < 0) |
8c6db833 LP |
694 | pam_syslog(handle, LOG_ERR, "Failed to migrate session cgroup: %s", strerror(-r)); |
695 | } | |
74fe1fe3 LP |
696 | |
697 | STRV_FOREACH(c, controllers) { | |
698 | create_user_group(handle, *c, nosession_path, pw, false, false); | |
699 | ||
700 | if ((r = cg_migrate_recursive(*c, session_path, nosession_path, false, true)) < 0) | |
701 | pam_syslog(handle, LOG_ERR, "Failed to migrate session cgroup in hierarchy %s: %s", *c, strerror(-r)); | |
702 | } | |
8c6db833 LP |
703 | } |
704 | ||
705 | /* GC user tree */ | |
c6c18be3 | 706 | cg_trim(SYSTEMD_CGROUP_CONTROLLER, user_path, false); |
8c6db833 LP |
707 | |
708 | if ((r = session_remains(handle, user_path)) < 0) | |
709 | pam_syslog(handle, LOG_ERR, "Failed to determine whether a session remains: %s", strerror(-r)); | |
710 | ||
711 | /* Kill user processes not attached to any session */ | |
e9fbc77c | 712 | if (kill_user && r == 0 && check_user_lists(handle, pw->pw_uid, kill_only_users, kill_exclude_users)) { |
8c6db833 | 713 | |
824a1d59 | 714 | /* Kill user cgroup */ |
35d2e7ec | 715 | if ((r = cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, user_path, true)) < 0) |
8c6db833 LP |
716 | pam_syslog(handle, LOG_ERR, "Failed to kill user cgroup: %s", strerror(-r)); |
717 | } else { | |
718 | ||
c6c18be3 | 719 | if ((r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, user_path, true)) < 0) |
8c6db833 LP |
720 | pam_syslog(handle, LOG_ERR, "Failed to check user cgroup: %s", strerror(-r)); |
721 | ||
35d2e7ec LP |
722 | /* Remove user cgroup */ |
723 | if (r > 0) { | |
724 | if ((r = cg_delete(SYSTEMD_CGROUP_CONTROLLER, user_path)) < 0) | |
725 | pam_syslog(handle, LOG_ERR, "Failed to delete user cgroup: %s", strerror(-r)); | |
726 | ||
727 | /* If we managed to find somebody, don't cleanup the cgroup. */ | |
728 | } else if (r == 0) | |
8c6db833 LP |
729 | r = -EBUSY; |
730 | } | |
731 | ||
74fe1fe3 LP |
732 | STRV_FOREACH(c, controllers) |
733 | cg_trim(*c, user_path, true); | |
734 | ||
8c6db833 LP |
735 | if (r >= 0) { |
736 | const char *runtime_dir; | |
737 | ||
8c6db833 LP |
738 | if ((runtime_dir = pam_getenv(handle, "XDG_RUNTIME_DIR"))) |
739 | if ((r = rm_rf(runtime_dir, false, true)) < 0) | |
740 | pam_syslog(handle, LOG_ERR, "Failed to remove runtime directory: %s", strerror(-r)); | |
741 | } | |
742 | ||
672c48cc LP |
743 | /* pam_syslog(handle, LOG_DEBUG, "pam-systemd done"); */ |
744 | ||
8c6db833 LP |
745 | r = PAM_SUCCESS; |
746 | ||
747 | finish: | |
748 | if (lock_fd >= 0) | |
749 | close_nointr_nofail(lock_fd); | |
750 | ||
751 | free(session_path); | |
752 | free(nosession_path); | |
753 | free(user_path); | |
754 | ||
74fe1fe3 | 755 | strv_free(controllers); |
e9fbc77c LP |
756 | strv_free(kill_exclude_users); |
757 | strv_free(kill_only_users); | |
74fe1fe3 | 758 | |
1f73f0f1 LP |
759 | free(cgroup_user_tree); |
760 | ||
8c6db833 LP |
761 | return r; |
762 | } |