1 | /* Inner loops of cache daemon. |
2 | Copyright (C) 1998-2024 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | This program is free software; you can redistribute it and/or modify |
6 | it under the terms of the GNU General Public License as published |
7 | by the Free Software Foundation; version 2 of the License, or |
8 | (at your option) any later version. |
9 | |
10 | This program is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
13 | GNU General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU General Public License |
16 | along with this program; if not, see <https://www.gnu.org/licenses/>. */ |
17 | |
18 | #include <alloca.h> |
19 | #include <assert.h> |
20 | #include <atomic.h> |
21 | #include <error.h> |
22 | #include <errno.h> |
23 | #include <fcntl.h> |
24 | #include <grp.h> |
25 | #include <ifaddrs.h> |
26 | #include <libintl.h> |
27 | #include <pthread.h> |
28 | #include <pwd.h> |
29 | #include <resolv.h> |
30 | #include <stdio.h> |
31 | #include <stdlib.h> |
32 | #include <unistd.h> |
33 | #include <stdint.h> |
34 | #include <arpa/inet.h> |
35 | #ifdef HAVE_NETLINK |
36 | # include <linux/netlink.h> |
37 | # include <linux/rtnetlink.h> |
38 | #endif |
39 | #ifdef HAVE_EPOLL |
40 | # include <sys/epoll.h> |
41 | #endif |
42 | #ifdef HAVE_INOTIFY |
43 | # include <sys/inotify.h> |
44 | #endif |
45 | #include <sys/mman.h> |
46 | #include <sys/param.h> |
47 | #include <sys/poll.h> |
48 | #include <sys/socket.h> |
49 | #include <sys/stat.h> |
50 | #include <sys/un.h> |
51 | |
52 | #include "nscd.h" |
53 | #include "dbg_log.h" |
54 | #include "selinux.h" |
55 | #include <resolv/resolv.h> |
56 | |
57 | #include <kernel-features.h> |
58 | #include <libc-diag.h> |
59 | |
60 | |
61 | /* Support to run nscd as an unprivileged user */ |
62 | const char *server_user; |
63 | static uid_t server_uid; |
64 | static gid_t server_gid; |
65 | const char *stat_user; |
66 | uid_t stat_uid; |
67 | static gid_t *server_groups; |
68 | #ifndef NGROUPS |
69 | # define NGROUPS 32 |
70 | #endif |
71 | static int server_ngroups; |
72 | |
73 | static pthread_attr_t attr; |
74 | |
75 | static void begin_drop_privileges (void); |
76 | static void finish_drop_privileges (void); |
77 | |
78 | /* Map request type to a string. */ |
79 | const char *const serv2str[LASTREQ] = |
80 | { |
81 | [GETPWBYNAME] = "GETPWBYNAME" , |
82 | [GETPWBYUID] = "GETPWBYUID" , |
83 | [GETGRBYNAME] = "GETGRBYNAME" , |
84 | [GETGRBYGID] = "GETGRBYGID" , |
85 | [GETHOSTBYNAME] = "GETHOSTBYNAME" , |
86 | [GETHOSTBYNAMEv6] = "GETHOSTBYNAMEv6" , |
87 | [GETHOSTBYADDR] = "GETHOSTBYADDR" , |
88 | [GETHOSTBYADDRv6] = "GETHOSTBYADDRv6" , |
89 | [SHUTDOWN] = "SHUTDOWN" , |
90 | [GETSTAT] = "GETSTAT" , |
91 | [INVALIDATE] = "INVALIDATE" , |
92 | [GETFDPW] = "GETFDPW" , |
93 | [GETFDGR] = "GETFDGR" , |
94 | [GETFDHST] = "GETFDHST" , |
95 | [GETAI] = "GETAI" , |
96 | [INITGROUPS] = "INITGROUPS" , |
97 | [GETSERVBYNAME] = "GETSERVBYNAME" , |
98 | [GETSERVBYPORT] = "GETSERVBYPORT" , |
99 | [GETFDSERV] = "GETFDSERV" , |
100 | [GETNETGRENT] = "GETNETGRENT" , |
101 | [INNETGR] = "INNETGR" , |
102 | [GETFDNETGR] = "GETFDNETGR" |
103 | }; |
104 | |
105 | #ifdef PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP |
106 | # define RWLOCK_INITIALIZER PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP |
107 | #else |
108 | # define RWLOCK_INITIALIZER PTHREAD_RWLOCK_INITIALIZER |
109 | #endif |
110 | |
111 | /* The control data structures for the services. */ |
112 | struct database_dyn dbs[lastdb] = |
113 | { |
114 | [pwddb] = { |
115 | .lock = RWLOCK_INITIALIZER, |
116 | .prune_lock = PTHREAD_MUTEX_INITIALIZER, |
117 | .prune_run_lock = PTHREAD_MUTEX_INITIALIZER, |
118 | .enabled = 0, |
119 | .check_file = 1, |
120 | .persistent = 0, |
121 | .propagate = 1, |
122 | .shared = 0, |
123 | .max_db_size = DEFAULT_MAX_DB_SIZE, |
124 | .suggested_module = DEFAULT_SUGGESTED_MODULE, |
125 | .db_filename = _PATH_NSCD_PASSWD_DB, |
126 | .disabled_iov = &pwd_iov_disabled, |
127 | .postimeout = 3600, |
128 | .negtimeout = 20, |
129 | .wr_fd = -1, |
130 | .ro_fd = -1, |
131 | .mmap_used = false |
132 | }, |
133 | [grpdb] = { |
134 | .lock = RWLOCK_INITIALIZER, |
135 | .prune_lock = PTHREAD_MUTEX_INITIALIZER, |
136 | .prune_run_lock = PTHREAD_MUTEX_INITIALIZER, |
137 | .enabled = 0, |
138 | .check_file = 1, |
139 | .persistent = 0, |
140 | .propagate = 1, |
141 | .shared = 0, |
142 | .max_db_size = DEFAULT_MAX_DB_SIZE, |
143 | .suggested_module = DEFAULT_SUGGESTED_MODULE, |
144 | .db_filename = _PATH_NSCD_GROUP_DB, |
145 | .disabled_iov = &grp_iov_disabled, |
146 | .postimeout = 3600, |
147 | .negtimeout = 60, |
148 | .wr_fd = -1, |
149 | .ro_fd = -1, |
150 | .mmap_used = false |
151 | }, |
152 | [hstdb] = { |
153 | .lock = RWLOCK_INITIALIZER, |
154 | .prune_lock = PTHREAD_MUTEX_INITIALIZER, |
155 | .prune_run_lock = PTHREAD_MUTEX_INITIALIZER, |
156 | .enabled = 0, |
157 | .check_file = 1, |
158 | .persistent = 0, |
159 | .propagate = 0, /* Not used. */ |
160 | .shared = 0, |
161 | .max_db_size = DEFAULT_MAX_DB_SIZE, |
162 | .suggested_module = DEFAULT_SUGGESTED_MODULE, |
163 | .db_filename = _PATH_NSCD_HOSTS_DB, |
164 | .disabled_iov = &hst_iov_disabled, |
165 | .postimeout = 3600, |
166 | .negtimeout = 20, |
167 | .wr_fd = -1, |
168 | .ro_fd = -1, |
169 | .mmap_used = false |
170 | }, |
171 | [servdb] = { |
172 | .lock = RWLOCK_INITIALIZER, |
173 | .prune_lock = PTHREAD_MUTEX_INITIALIZER, |
174 | .prune_run_lock = PTHREAD_MUTEX_INITIALIZER, |
175 | .enabled = 0, |
176 | .check_file = 1, |
177 | .persistent = 0, |
178 | .propagate = 0, /* Not used. */ |
179 | .shared = 0, |
180 | .max_db_size = DEFAULT_MAX_DB_SIZE, |
181 | .suggested_module = DEFAULT_SUGGESTED_MODULE, |
182 | .db_filename = _PATH_NSCD_SERVICES_DB, |
183 | .disabled_iov = &serv_iov_disabled, |
184 | .postimeout = 28800, |
185 | .negtimeout = 20, |
186 | .wr_fd = -1, |
187 | .ro_fd = -1, |
188 | .mmap_used = false |
189 | }, |
190 | [netgrdb] = { |
191 | .lock = RWLOCK_INITIALIZER, |
192 | .prune_lock = PTHREAD_MUTEX_INITIALIZER, |
193 | .prune_run_lock = PTHREAD_MUTEX_INITIALIZER, |
194 | .enabled = 0, |
195 | .check_file = 1, |
196 | .persistent = 0, |
197 | .propagate = 0, /* Not used. */ |
198 | .shared = 0, |
199 | .max_db_size = DEFAULT_MAX_DB_SIZE, |
200 | .suggested_module = DEFAULT_SUGGESTED_MODULE, |
201 | .db_filename = _PATH_NSCD_NETGROUP_DB, |
202 | .disabled_iov = &netgroup_iov_disabled, |
203 | .postimeout = 28800, |
204 | .negtimeout = 20, |
205 | .wr_fd = -1, |
206 | .ro_fd = -1, |
207 | .mmap_used = false |
208 | } |
209 | }; |
210 | |
211 | |
212 | /* Mapping of request type to database. */ |
213 | static struct |
214 | { |
215 | bool data_request; |
216 | struct database_dyn *db; |
217 | } const reqinfo[LASTREQ] = |
218 | { |
219 | [GETPWBYNAME] = { true, .db: &dbs[pwddb] }, |
220 | [GETPWBYUID] = { true, .db: &dbs[pwddb] }, |
221 | [GETGRBYNAME] = { true, .db: &dbs[grpdb] }, |
222 | [GETGRBYGID] = { true, .db: &dbs[grpdb] }, |
223 | [GETHOSTBYNAME] = { true, .db: &dbs[hstdb] }, |
224 | [GETHOSTBYNAMEv6] = { true, .db: &dbs[hstdb] }, |
225 | [GETHOSTBYADDR] = { true, .db: &dbs[hstdb] }, |
226 | [GETHOSTBYADDRv6] = { true, .db: &dbs[hstdb] }, |
227 | [SHUTDOWN] = { false, NULL }, |
228 | [GETSTAT] = { false, NULL }, |
229 | [GETFDPW] = { false, .db: &dbs[pwddb] }, |
230 | [GETFDGR] = { false, .db: &dbs[grpdb] }, |
231 | [GETFDHST] = { false, .db: &dbs[hstdb] }, |
232 | [GETAI] = { true, .db: &dbs[hstdb] }, |
233 | [INITGROUPS] = { true, .db: &dbs[grpdb] }, |
234 | [GETSERVBYNAME] = { true, .db: &dbs[servdb] }, |
235 | [GETSERVBYPORT] = { true, .db: &dbs[servdb] }, |
236 | [GETFDSERV] = { false, .db: &dbs[servdb] }, |
237 | [GETNETGRENT] = { true, .db: &dbs[netgrdb] }, |
238 | [INNETGR] = { true, .db: &dbs[netgrdb] }, |
239 | [GETFDNETGR] = { false, .db: &dbs[netgrdb] } |
240 | }; |
241 | |
242 | |
243 | /* Initial number of threads to use. */ |
244 | int nthreads = -1; |
245 | /* Maximum number of threads to use. */ |
246 | int max_nthreads = 32; |
247 | |
248 | /* Socket for incoming connections. */ |
249 | static int sock; |
250 | |
251 | #ifdef HAVE_INOTIFY |
252 | /* Inotify descriptor. */ |
253 | int inotify_fd = -1; |
254 | #endif |
255 | |
256 | #ifdef HAVE_NETLINK |
257 | /* Descriptor for netlink status updates. */ |
258 | static int nl_status_fd = -1; |
259 | |
260 | static uint32_t |
261 | __bump_nl_timestamp (void) |
262 | { |
263 | static uint32_t nl_timestamp; |
264 | |
265 | if (atomic_fetch_add_relaxed (&nl_timestamp, 1) + 1 == 0) |
266 | atomic_fetch_add_relaxed (&nl_timestamp, 1); |
267 | |
268 | return nl_timestamp; |
269 | } |
270 | #endif |
271 | |
272 | /* Number of times clients had to wait. */ |
273 | unsigned long int client_queued; |
274 | |
275 | |
276 | ssize_t |
277 | writeall (int fd, const void *buf, size_t len) |
278 | { |
279 | size_t n = len; |
280 | ssize_t ret; |
281 | do |
282 | { |
283 | ret = TEMP_FAILURE_RETRY (send (fd, buf, n, MSG_NOSIGNAL)); |
284 | if (ret <= 0) |
285 | break; |
286 | buf = (const char *) buf + ret; |
287 | n -= ret; |
288 | } |
289 | while (n > 0); |
290 | return ret < 0 ? ret : len - n; |
291 | } |
292 | |
293 | |
294 | enum usekey |
295 | { |
296 | use_not = 0, |
297 | /* The following three are not really used, they are symbolic constants. */ |
298 | use_first = 16, |
299 | use_begin = 32, |
300 | use_end = 64, |
301 | |
302 | use_he = 1, |
303 | use_he_begin = use_he | use_begin, |
304 | use_he_end = use_he | use_end, |
305 | use_data = 3, |
306 | use_data_begin = use_data | use_begin, |
307 | use_data_end = use_data | use_end, |
308 | use_data_first = use_data_begin | use_first |
309 | }; |
310 | |
311 | |
312 | static int |
313 | check_use (const char *data, nscd_ssize_t first_free, uint8_t *usemap, |
314 | enum usekey use, ref_t start, size_t len) |
315 | { |
316 | if (len < 2) |
317 | return 0; |
318 | |
319 | if (start > first_free || start + len > first_free |
320 | || (start & BLOCK_ALIGN_M1)) |
321 | return 0; |
322 | |
323 | if (usemap[start] == use_not) |
324 | { |
325 | /* Add the start marker. */ |
326 | usemap[start] = use | use_begin; |
327 | use &= ~use_first; |
328 | |
329 | while (--len > 0) |
330 | if (usemap[++start] != use_not) |
331 | return 0; |
332 | else |
333 | usemap[start] = use; |
334 | |
335 | /* Add the end marker. */ |
336 | usemap[start] = use | use_end; |
337 | } |
338 | else if ((usemap[start] & ~use_first) == ((use | use_begin) & ~use_first)) |
339 | { |
340 | /* Hash entries can't be shared. */ |
341 | if (use == use_he) |
342 | return 0; |
343 | |
344 | usemap[start] |= (use & use_first); |
345 | use &= ~use_first; |
346 | |
347 | while (--len > 1) |
348 | if (usemap[++start] != use) |
349 | return 0; |
350 | |
351 | if (usemap[++start] != (use | use_end)) |
352 | return 0; |
353 | } |
354 | else |
355 | /* Points to a wrong object or somewhere in the middle. */ |
356 | return 0; |
357 | |
358 | return 1; |
359 | } |
360 | |
361 | |
362 | /* Verify data in persistent database. */ |
363 | static int |
364 | verify_persistent_db (void *mem, struct database_pers_head *readhead, int dbnr) |
365 | { |
366 | assert (dbnr == pwddb || dbnr == grpdb || dbnr == hstdb || dbnr == servdb |
367 | || dbnr == netgrdb); |
368 | |
369 | time_t now = time (NULL); |
370 | |
371 | struct database_pers_head *head = mem; |
372 | struct database_pers_head head_copy = *head; |
373 | |
374 | /* Check that the header that was read matches the head in the database. */ |
375 | if (memcmp (s1: head, s2: readhead, n: sizeof (*head)) != 0) |
376 | return 0; |
377 | |
378 | /* First some easy tests: make sure the database header is sane. */ |
379 | if (head->version != DB_VERSION |
380 | || head->header_size != sizeof (*head) |
381 | /* We allow a timestamp to be one hour ahead of the current time. |
382 | This should cover daylight saving time changes. */ |
383 | || head->timestamp > now + 60 * 60 + 60 |
384 | || (head->gc_cycle & 1) |
385 | || head->module == 0 |
386 | || (size_t) head->module > INT32_MAX / sizeof (ref_t) |
387 | || (size_t) head->data_size > INT32_MAX - head->module * sizeof (ref_t) |
388 | || head->first_free < 0 |
389 | || head->first_free > head->data_size |
390 | || (head->first_free & BLOCK_ALIGN_M1) != 0 |
391 | || head->maxnentries < 0 |
392 | || head->maxnsearched < 0) |
393 | return 0; |
394 | |
395 | uint8_t *usemap = calloc (nmemb: head->first_free, size: 1); |
396 | if (usemap == NULL) |
397 | return 0; |
398 | |
399 | const char *data = (char *) &head->array[roundup (head->module, |
400 | ALIGN / sizeof (ref_t))]; |
401 | |
402 | nscd_ssize_t he_cnt = 0; |
403 | for (nscd_ssize_t cnt = 0; cnt < head->module; ++cnt) |
404 | { |
405 | ref_t trail = head->array[cnt]; |
406 | ref_t work = trail; |
407 | int tick = 0; |
408 | |
409 | while (work != ENDREF) |
410 | { |
411 | if (! check_use (data, first_free: head->first_free, usemap, use: use_he, start: work, |
412 | len: sizeof (struct hashentry))) |
413 | goto fail; |
414 | |
415 | /* Now we know we can dereference the record. */ |
416 | struct hashentry *here = (struct hashentry *) (data + work); |
417 | |
418 | ++he_cnt; |
419 | |
420 | /* Make sure the record is for this type of service. */ |
421 | if (here->type >= LASTREQ |
422 | || reqinfo[here->type].db != &dbs[dbnr]) |
423 | goto fail; |
424 | |
425 | /* Validate boolean field value. */ |
426 | if (here->first != false && here->first != true) |
427 | goto fail; |
428 | |
429 | if (here->len < 0) |
430 | goto fail; |
431 | |
432 | /* Now the data. */ |
433 | if (here->packet < 0 |
434 | || here->packet > head->first_free |
435 | || here->packet + sizeof (struct datahead) > head->first_free) |
436 | goto fail; |
437 | |
438 | struct datahead *dh = (struct datahead *) (data + here->packet); |
439 | |
440 | if (! check_use (data, first_free: head->first_free, usemap, |
441 | use: use_data | (here->first ? use_first : 0), |
442 | start: here->packet, len: dh->allocsize)) |
443 | goto fail; |
444 | |
445 | if (dh->allocsize < sizeof (struct datahead) |
446 | || dh->recsize > dh->allocsize |
447 | || (dh->notfound != false && dh->notfound != true) |
448 | || (dh->usable != false && dh->usable != true)) |
449 | goto fail; |
450 | |
451 | if (here->key < here->packet + sizeof (struct datahead) |
452 | || here->key > here->packet + dh->allocsize |
453 | || here->key + here->len > here->packet + dh->allocsize) |
454 | goto fail; |
455 | |
456 | work = here->next; |
457 | |
458 | if (work == trail) |
459 | /* A circular list, this must not happen. */ |
460 | goto fail; |
461 | if (tick) |
462 | trail = ((struct hashentry *) (data + trail))->next; |
463 | tick = 1 - tick; |
464 | } |
465 | } |
466 | |
467 | if (he_cnt != head->nentries) |
468 | goto fail; |
469 | |
470 | /* See if all data and keys had at least one reference from |
471 | he->first == true hashentry. */ |
472 | for (ref_t idx = 0; idx < head->first_free; ++idx) |
473 | { |
474 | if (usemap[idx] == use_data_begin) |
475 | goto fail; |
476 | } |
477 | |
478 | /* Finally, make sure the database hasn't changed since the first test. */ |
479 | if (memcmp (s1: mem, s2: &head_copy, n: sizeof (*head)) != 0) |
480 | goto fail; |
481 | |
482 | free (ptr: usemap); |
483 | return 1; |
484 | |
485 | fail: |
486 | free (ptr: usemap); |
487 | return 0; |
488 | } |
489 | |
490 | |
491 | /* Initialize database information structures. */ |
492 | void |
493 | nscd_init (void) |
494 | { |
495 | /* Look up unprivileged uid/gid/groups before we start listening on the |
496 | socket */ |
497 | if (server_user != NULL) |
498 | begin_drop_privileges (); |
499 | |
500 | if (nthreads == -1) |
501 | /* No configuration for this value, assume a default. */ |
502 | nthreads = 4; |
503 | |
504 | for (size_t cnt = 0; cnt < lastdb; ++cnt) |
505 | if (dbs[cnt].enabled) |
506 | { |
507 | pthread_rwlock_init (rwlock: &dbs[cnt].lock, NULL); |
508 | pthread_mutex_init (mutex: &dbs[cnt].memlock, NULL); |
509 | |
510 | if (dbs[cnt].persistent) |
511 | { |
512 | /* Try to open the appropriate file on disk. */ |
513 | int fd = open (file: dbs[cnt].db_filename, O_RDWR | O_CLOEXEC); |
514 | if (fd != -1) |
515 | { |
516 | char *msg = NULL; |
517 | struct stat64 st; |
518 | void *mem; |
519 | size_t total; |
520 | struct database_pers_head head; |
521 | ssize_t n = TEMP_FAILURE_RETRY (read (fd, &head, |
522 | sizeof (head))); |
523 | if (n != sizeof (head) || fstat64 (fd: fd, buf: &st) != 0) |
524 | { |
525 | fail_db_errno: |
526 | /* The code is single-threaded at this point so |
527 | using strerror is just fine. */ |
528 | msg = strerror (errno); |
529 | fail_db: |
530 | dbg_log (_("invalid persistent database file \"%s\": %s" ), |
531 | dbs[cnt].db_filename, msg); |
532 | unlink (name: dbs[cnt].db_filename); |
533 | } |
534 | else if (head.module == 0 && head.data_size == 0) |
535 | { |
536 | /* The file has been created, but the head has not |
537 | been initialized yet. */ |
538 | msg = _("uninitialized header" ); |
539 | goto fail_db; |
540 | } |
541 | else if (head.header_size != (int) sizeof (head)) |
542 | { |
543 | msg = _("header size does not match" ); |
544 | goto fail_db; |
545 | } |
546 | else if ((total = (sizeof (head) |
547 | + roundup (head.module * sizeof (ref_t), |
548 | ALIGN) |
549 | + head.data_size)) |
550 | > st.st_size |
551 | || total < sizeof (head)) |
552 | { |
553 | msg = _("file size does not match" ); |
554 | goto fail_db; |
555 | } |
556 | /* Note we map with the maximum size allowed for the |
557 | database. This is likely much larger than the |
558 | actual file size. This is OK on most OSes since |
559 | extensions of the underlying file will |
560 | automatically translate more pages available for |
561 | memory access. */ |
562 | else if ((mem = mmap (NULL, len: dbs[cnt].max_db_size, |
563 | PROT_READ | PROT_WRITE, |
564 | MAP_SHARED, fd: fd, offset: 0)) |
565 | == MAP_FAILED) |
566 | goto fail_db_errno; |
567 | else if (!verify_persistent_db (mem, readhead: &head, dbnr: cnt)) |
568 | { |
569 | munmap (addr: mem, len: total); |
570 | msg = _("verification failed" ); |
571 | goto fail_db; |
572 | } |
573 | else |
574 | { |
575 | /* Success. We have the database. */ |
576 | dbs[cnt].head = mem; |
577 | dbs[cnt].memsize = total; |
578 | dbs[cnt].data = (char *) |
579 | &dbs[cnt].head->array[roundup (dbs[cnt].head->module, |
580 | ALIGN / sizeof (ref_t))]; |
581 | dbs[cnt].mmap_used = true; |
582 | |
583 | if (dbs[cnt].suggested_module > head.module) |
584 | dbg_log (_("suggested size of table for database %s larger than the persistent database's table" ), |
585 | dbnames[cnt]); |
586 | |
587 | dbs[cnt].wr_fd = fd; |
588 | fd = -1; |
589 | /* We also need a read-only descriptor. */ |
590 | if (dbs[cnt].shared) |
591 | { |
592 | dbs[cnt].ro_fd = open (file: dbs[cnt].db_filename, |
593 | O_RDONLY | O_CLOEXEC); |
594 | if (dbs[cnt].ro_fd == -1) |
595 | dbg_log (_("\ |
596 | cannot create read-only descriptor for \"%s\"; no mmap" ), |
597 | dbs[cnt].db_filename); |
598 | } |
599 | |
600 | // XXX Shall we test whether the descriptors actually |
601 | // XXX point to the same file? |
602 | } |
603 | |
604 | /* Close the file descriptors in case something went |
605 | wrong in which case the variable have not been |
606 | assigned -1. */ |
607 | if (fd != -1) |
608 | close (fd: fd); |
609 | } |
610 | else if (errno == EACCES) |
611 | do_exit (EXIT_FAILURE, errnum: 0, _("cannot access '%s'" ), |
612 | dbs[cnt].db_filename); |
613 | } |
614 | |
615 | if (dbs[cnt].head == NULL) |
616 | { |
617 | /* No database loaded. Allocate the data structure, |
618 | possibly on disk. */ |
619 | struct database_pers_head head; |
620 | size_t total = (sizeof (head) |
621 | + roundup (dbs[cnt].suggested_module |
622 | * sizeof (ref_t), ALIGN) |
623 | + (dbs[cnt].suggested_module |
624 | * DEFAULT_DATASIZE_PER_BUCKET)); |
625 | |
626 | /* Try to create the database. If we do not need a |
627 | persistent database create a temporary file. */ |
628 | int fd; |
629 | int ro_fd = -1; |
630 | if (dbs[cnt].persistent) |
631 | { |
632 | fd = open (file: dbs[cnt].db_filename, |
633 | O_RDWR | O_CREAT | O_EXCL | O_TRUNC | O_CLOEXEC, |
634 | S_IRUSR | S_IWUSR); |
635 | if (fd != -1 && dbs[cnt].shared) |
636 | ro_fd = open (file: dbs[cnt].db_filename, |
637 | O_RDONLY | O_CLOEXEC); |
638 | } |
639 | else |
640 | { |
641 | char fname[] = _PATH_NSCD_XYZ_DB_TMP; |
642 | fd = mkostemp (template: fname, O_CLOEXEC); |
643 | |
644 | /* We do not need the file name anymore after we |
645 | opened another file descriptor in read-only mode. */ |
646 | if (fd != -1) |
647 | { |
648 | if (dbs[cnt].shared) |
649 | ro_fd = open (file: fname, O_RDONLY | O_CLOEXEC); |
650 | |
651 | unlink (name: fname); |
652 | } |
653 | } |
654 | |
655 | if (fd == -1) |
656 | { |
657 | if (errno == EEXIST) |
658 | { |
659 | dbg_log (_("database for %s corrupted or simultaneously used; remove %s manually if necessary and restart" ), |
660 | dbnames[cnt], dbs[cnt].db_filename); |
661 | do_exit (child_ret: 1, errnum: 0, NULL); |
662 | } |
663 | |
664 | if (dbs[cnt].persistent) |
665 | dbg_log (_("cannot create %s; no persistent database used" ), |
666 | dbs[cnt].db_filename); |
667 | else |
668 | dbg_log (_("cannot create %s; no sharing possible" ), |
669 | dbs[cnt].db_filename); |
670 | |
671 | dbs[cnt].persistent = 0; |
672 | // XXX remember: no mmap |
673 | } |
674 | else |
675 | { |
676 | /* Tell the user if we could not create the read-only |
677 | descriptor. */ |
678 | if (ro_fd == -1 && dbs[cnt].shared) |
679 | dbg_log (_("\ |
680 | cannot create read-only descriptor for \"%s\"; no mmap" ), |
681 | dbs[cnt].db_filename); |
682 | |
683 | /* Before we create the header, initialize the hash |
684 | table. That way if we get interrupted while writing |
685 | the header we can recognize a partially initialized |
686 | database. */ |
687 | size_t ps = sysconf (_SC_PAGESIZE); |
688 | char tmpbuf[ps]; |
689 | assert (~ENDREF == 0); |
690 | memset (s: tmpbuf, c: '\xff', n: ps); |
691 | |
692 | size_t remaining = dbs[cnt].suggested_module * sizeof (ref_t); |
693 | off_t offset = sizeof (head); |
694 | |
695 | size_t towrite; |
696 | if (offset % ps != 0) |
697 | { |
698 | towrite = MIN (remaining, ps - (offset % ps)); |
699 | if (pwrite (fd: fd, buf: tmpbuf, nbytes: towrite, offset: offset) != towrite) |
700 | goto write_fail; |
701 | offset += towrite; |
702 | remaining -= towrite; |
703 | } |
704 | |
705 | while (remaining > ps) |
706 | { |
707 | if (pwrite (fd: fd, buf: tmpbuf, nbytes: ps, offset: offset) == -1) |
708 | goto write_fail; |
709 | offset += ps; |
710 | remaining -= ps; |
711 | } |
712 | |
713 | if (remaining > 0 |
714 | && pwrite (fd: fd, buf: tmpbuf, nbytes: remaining, offset: offset) != remaining) |
715 | goto write_fail; |
716 | |
717 | /* Create the header of the file. */ |
718 | struct database_pers_head head = |
719 | { |
720 | .version = DB_VERSION, |
721 | .header_size = sizeof (head), |
722 | .module = dbs[cnt].suggested_module, |
723 | .data_size = (dbs[cnt].suggested_module |
724 | * DEFAULT_DATASIZE_PER_BUCKET), |
725 | .first_free = 0 |
726 | }; |
727 | void *mem; |
728 | |
729 | if ((TEMP_FAILURE_RETRY (write (fd, &head, sizeof (head))) |
730 | != sizeof (head)) |
731 | || (TEMP_FAILURE_RETRY_VAL (posix_fallocate (fd, 0, total)) |
732 | != 0) |
733 | || (mem = mmap (NULL, len: dbs[cnt].max_db_size, |
734 | PROT_READ | PROT_WRITE, |
735 | MAP_SHARED, fd: fd, offset: 0)) == MAP_FAILED) |
736 | { |
737 | write_fail: |
738 | unlink (name: dbs[cnt].db_filename); |
739 | dbg_log (_("cannot write to database file %s: %s" ), |
740 | dbs[cnt].db_filename, strerror (errno)); |
741 | dbs[cnt].persistent = 0; |
742 | } |
743 | else |
744 | { |
745 | /* Success. */ |
746 | dbs[cnt].head = mem; |
747 | dbs[cnt].data = (char *) |
748 | &dbs[cnt].head->array[roundup (dbs[cnt].head->module, |
749 | ALIGN / sizeof (ref_t))]; |
750 | dbs[cnt].memsize = total; |
751 | dbs[cnt].mmap_used = true; |
752 | |
753 | /* Remember the descriptors. */ |
754 | dbs[cnt].wr_fd = fd; |
755 | dbs[cnt].ro_fd = ro_fd; |
756 | fd = -1; |
757 | ro_fd = -1; |
758 | } |
759 | |
760 | if (fd != -1) |
761 | close (fd: fd); |
762 | if (ro_fd != -1) |
763 | close (fd: ro_fd); |
764 | } |
765 | } |
766 | |
767 | if (dbs[cnt].head == NULL) |
768 | { |
769 | /* We do not use the persistent database. Just |
770 | create an in-memory data structure. */ |
771 | assert (! dbs[cnt].persistent); |
772 | |
773 | dbs[cnt].head = xmalloc (n: sizeof (struct database_pers_head) |
774 | + (dbs[cnt].suggested_module |
775 | * sizeof (ref_t))); |
776 | memset (s: dbs[cnt].head, c: '\0', n: sizeof (struct database_pers_head)); |
777 | assert (~ENDREF == 0); |
778 | memset (s: dbs[cnt].head->array, c: '\xff', |
779 | n: dbs[cnt].suggested_module * sizeof (ref_t)); |
780 | dbs[cnt].head->module = dbs[cnt].suggested_module; |
781 | dbs[cnt].head->data_size = (DEFAULT_DATASIZE_PER_BUCKET |
782 | * dbs[cnt].head->module); |
783 | dbs[cnt].data = xmalloc (n: dbs[cnt].head->data_size); |
784 | dbs[cnt].head->first_free = 0; |
785 | |
786 | dbs[cnt].shared = 0; |
787 | assert (dbs[cnt].ro_fd == -1); |
788 | } |
789 | } |
790 | |
791 | /* Create the socket. */ |
792 | sock = socket (AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, protocol: 0); |
793 | if (sock < 0) |
794 | { |
795 | dbg_log (_("cannot open socket: %s" ), strerror (errno)); |
796 | do_exit (errno == EACCES ? 4 : 1, errnum: 0, NULL); |
797 | } |
798 | /* Bind a name to the socket. */ |
799 | struct sockaddr_un sock_addr; |
800 | sock_addr.sun_family = AF_UNIX; |
801 | strcpy (dest: sock_addr.sun_path, _PATH_NSCDSOCKET); |
802 | if (bind (fd: sock, addr: (struct sockaddr *) &sock_addr, len: sizeof (sock_addr)) < 0) |
803 | { |
804 | dbg_log (str: "%s: %s" , _PATH_NSCDSOCKET, strerror (errno)); |
805 | do_exit (errno == EACCES ? 4 : 1, errnum: 0, NULL); |
806 | } |
807 | |
808 | /* Set permissions for the socket. */ |
809 | chmod (_PATH_NSCDSOCKET, DEFFILEMODE); |
810 | |
811 | /* Set the socket up to accept connections. */ |
812 | if (listen (fd: sock, SOMAXCONN) < 0) |
813 | { |
814 | dbg_log (_("cannot enable socket to accept connections: %s" ), |
815 | strerror (errno)); |
816 | do_exit (child_ret: 1, errnum: 0, NULL); |
817 | } |
818 | |
819 | #ifdef HAVE_NETLINK |
820 | if (dbs[hstdb].enabled) |
821 | { |
822 | /* Try to open netlink socket to monitor network setting changes. */ |
823 | nl_status_fd = socket (AF_NETLINK, |
824 | SOCK_RAW | SOCK_CLOEXEC | SOCK_NONBLOCK, |
825 | NETLINK_ROUTE); |
826 | if (nl_status_fd != -1) |
827 | { |
828 | struct sockaddr_nl snl; |
829 | memset (s: &snl, c: '\0', n: sizeof (snl)); |
830 | snl.nl_family = AF_NETLINK; |
831 | /* XXX Is this the best set to use? */ |
832 | snl.nl_groups = (RTMGRP_IPV4_IFADDR | RTMGRP_TC | RTMGRP_IPV4_MROUTE |
833 | | RTMGRP_IPV4_ROUTE | RTMGRP_IPV4_RULE |
834 | | RTMGRP_IPV6_IFADDR | RTMGRP_IPV6_MROUTE |
835 | | RTMGRP_IPV6_ROUTE | RTMGRP_IPV6_IFINFO |
836 | | RTMGRP_IPV6_PREFIX); |
837 | |
838 | if (bind (fd: nl_status_fd, addr: (struct sockaddr *) &snl, len: sizeof (snl)) != 0) |
839 | { |
840 | close (fd: nl_status_fd); |
841 | nl_status_fd = -1; |
842 | } |
843 | else |
844 | { |
845 | /* Start the timestamp process. */ |
846 | dbs[hstdb].head->extra_data[NSCD_HST_IDX_CONF_TIMESTAMP] |
847 | = __bump_nl_timestamp (); |
848 | } |
849 | } |
850 | } |
851 | #endif |
852 | |
853 | /* Change to unprivileged uid/gid/groups if specified in config file */ |
854 | if (server_user != NULL) |
855 | finish_drop_privileges (); |
856 | } |
857 | |
858 | #ifdef HAVE_INOTIFY |
859 | #define TRACED_FILE_MASK (IN_DELETE_SELF | IN_CLOSE_WRITE | IN_MOVE_SELF) |
860 | #define TRACED_DIR_MASK (IN_DELETE_SELF | IN_CREATE | IN_MOVED_TO | IN_MOVE_SELF) |
861 | void |
862 | install_watches (struct traced_file *finfo) |
863 | { |
864 | /* Use inotify support if we have it. */ |
865 | if (finfo->inotify_descr[TRACED_FILE] < 0) |
866 | finfo->inotify_descr[TRACED_FILE] = inotify_add_watch (fd: inotify_fd, |
867 | name: finfo->fname, |
868 | TRACED_FILE_MASK); |
869 | if (finfo->inotify_descr[TRACED_FILE] < 0) |
870 | { |
871 | dbg_log (_("disabled inotify-based monitoring for file `%s': %s" ), |
872 | finfo->fname, strerror (errno)); |
873 | return; |
874 | } |
875 | dbg_log (_("monitoring file `%s` (%d)" ), |
876 | finfo->fname, finfo->inotify_descr[TRACED_FILE]); |
877 | /* Additionally listen for events in the file's parent directory. |
878 | We do this because the file to be watched might be |
879 | deleted and then added back again. When it is added back again |
880 | we must re-add the watch. We must also cover IN_MOVED_TO to |
881 | detect a file being moved into the directory. */ |
882 | if (finfo->inotify_descr[TRACED_DIR] < 0) |
883 | finfo->inotify_descr[TRACED_DIR] = inotify_add_watch (fd: inotify_fd, |
884 | name: finfo->dname, |
885 | TRACED_DIR_MASK); |
886 | if (finfo->inotify_descr[TRACED_DIR] < 0) |
887 | { |
888 | dbg_log (_("disabled inotify-based monitoring for directory `%s': %s" ), |
889 | finfo->fname, strerror (errno)); |
890 | return; |
891 | } |
892 | dbg_log (_("monitoring directory `%s` (%d)" ), |
893 | finfo->dname, finfo->inotify_descr[TRACED_DIR]); |
894 | } |
895 | #endif |
896 | |
897 | /* Register the file in FINFO as a traced file for the database DBS[DBIX]. |
898 | |
899 | We support registering multiple files per database. Each call to |
900 | register_traced_file adds to the list of registered files. |
901 | |
902 | When we prune the database, either through timeout or a request to |
903 | invalidate, we will check to see if any of the registered files has changed. |
904 | When we accept new connections to handle a cache request we will also |
905 | check to see if any of the registered files has changed. |
906 | |
907 | If we have inotify support then we install an inotify fd to notify us of |
908 | file deletion or modification, both of which will require we invalidate |
909 | the cache for the database. Without inotify support we stat the file and |
910 | store st_mtime to determine if the file has been modified. */ |
911 | void |
912 | register_traced_file (size_t dbidx, struct traced_file *finfo) |
913 | { |
914 | /* If the database is disabled or file checking is disabled |
915 | then ignore the registration. */ |
916 | if (! dbs[dbidx].enabled || ! dbs[dbidx].check_file) |
917 | return; |
918 | |
919 | if (__glibc_unlikely (debug_level > 0)) |
920 | dbg_log (_("monitoring file %s for database %s" ), |
921 | finfo->fname, dbnames[dbidx]); |
922 | |
923 | #ifdef HAVE_INOTIFY |
924 | install_watches (finfo); |
925 | #endif |
926 | struct stat64 st; |
927 | if (stat64 (file: finfo->fname, buf: &st) < 0) |
928 | { |
929 | /* We cannot stat() the file. Set mtime to zero and try again later. */ |
930 | dbg_log (_("stat failed for file `%s'; will try again later: %s" ), |
931 | finfo->fname, strerror (errno)); |
932 | finfo->mtime = 0; |
933 | } |
934 | else |
935 | finfo->mtime = st.st_mtime; |
936 | |
937 | /* Queue up the file name. */ |
938 | finfo->next = dbs[dbidx].traced_files; |
939 | dbs[dbidx].traced_files = finfo; |
940 | } |
941 | |
942 | |
943 | /* Close the connections. */ |
944 | void |
945 | close_sockets (void) |
946 | { |
947 | close (fd: sock); |
948 | } |
949 | |
950 | |
951 | static void |
952 | invalidate_cache (char *key, int fd) |
953 | { |
954 | dbtype number; |
955 | int32_t resp; |
956 | |
957 | for (number = pwddb; number < lastdb; ++number) |
958 | if (strcmp (s1: key, s2: dbnames[number]) == 0) |
959 | { |
960 | struct traced_file *runp = dbs[number].traced_files; |
961 | while (runp != NULL) |
962 | { |
963 | /* Make sure we reload from file when checking mtime. */ |
964 | runp->mtime = 0; |
965 | #ifdef HAVE_INOTIFY |
966 | /* During an invalidation we try to reload the traced |
967 | file watches. This allows the user to re-sync if |
968 | inotify events were lost. Similar to what we do during |
969 | pruning. */ |
970 | install_watches (finfo: runp); |
971 | #endif |
972 | if (runp->call_res_init) |
973 | { |
974 | res_init (); |
975 | break; |
976 | } |
977 | runp = runp->next; |
978 | } |
979 | break; |
980 | } |
981 | |
982 | if (number == lastdb) |
983 | { |
984 | resp = EINVAL; |
985 | writeall (fd, buf: &resp, len: sizeof (resp)); |
986 | return; |
987 | } |
988 | |
989 | if (dbs[number].enabled) |
990 | { |
991 | pthread_mutex_lock (mutex: &dbs[number].prune_run_lock); |
992 | prune_cache (table: &dbs[number], LONG_MAX, fd); |
993 | pthread_mutex_unlock (mutex: &dbs[number].prune_run_lock); |
994 | } |
995 | else |
996 | { |
997 | resp = 0; |
998 | writeall (fd, buf: &resp, len: sizeof (resp)); |
999 | } |
1000 | } |
1001 | |
1002 | |
1003 | #ifdef SCM_RIGHTS |
1004 | static void |
1005 | send_ro_fd (struct database_dyn *db, char *key, int fd) |
1006 | { |
1007 | /* If we do not have an read-only file descriptor do nothing. */ |
1008 | if (db->ro_fd == -1) |
1009 | return; |
1010 | |
1011 | /* We need to send some data along with the descriptor. */ |
1012 | uint64_t mapsize = (db->head->data_size |
1013 | + roundup (db->head->module * sizeof (ref_t), ALIGN) |
1014 | + sizeof (struct database_pers_head)); |
1015 | struct iovec iov[2]; |
1016 | iov[0].iov_base = key; |
1017 | iov[0].iov_len = strlen (s: key) + 1; |
1018 | iov[1].iov_base = &mapsize; |
1019 | iov[1].iov_len = sizeof (mapsize); |
1020 | |
1021 | /* Prepare the control message to transfer the descriptor. */ |
1022 | union |
1023 | { |
1024 | struct cmsghdr hdr; |
1025 | char bytes[CMSG_SPACE (sizeof (int))]; |
1026 | } buf; |
1027 | struct msghdr msg = { .msg_iov = iov, .msg_iovlen = 2, |
1028 | .msg_control = buf.bytes, |
1029 | .msg_controllen = sizeof (buf) }; |
1030 | struct cmsghdr *cmsg = CMSG_FIRSTHDR (&msg); |
1031 | |
1032 | cmsg->cmsg_level = SOL_SOCKET; |
1033 | cmsg->cmsg_type = SCM_RIGHTS; |
1034 | cmsg->cmsg_len = CMSG_LEN (sizeof (int)); |
1035 | |
1036 | int *ip = (int *) CMSG_DATA (cmsg); |
1037 | *ip = db->ro_fd; |
1038 | |
1039 | msg.msg_controllen = cmsg->cmsg_len; |
1040 | |
1041 | /* Send the control message. We repeat when we are interrupted but |
1042 | everything else is ignored. */ |
1043 | #ifndef MSG_NOSIGNAL |
1044 | # define MSG_NOSIGNAL 0 |
1045 | #endif |
1046 | (void) TEMP_FAILURE_RETRY (sendmsg (fd, &msg, MSG_NOSIGNAL)); |
1047 | |
1048 | if (__glibc_unlikely (debug_level > 0)) |
1049 | dbg_log (_("provide access to FD %d, for %s" ), db->ro_fd, key); |
1050 | } |
1051 | #endif /* SCM_RIGHTS */ |
1052 | |
1053 | |
1054 | /* Handle new request. */ |
1055 | static void |
1056 | handle_request (int fd, request_header *req, void *key, uid_t uid, pid_t pid) |
1057 | { |
1058 | if (__builtin_expect (req->version, NSCD_VERSION) != NSCD_VERSION) |
1059 | { |
1060 | if (debug_level > 0) |
1061 | dbg_log (_("\ |
1062 | cannot handle old request version %d; current version is %d" ), |
1063 | req->version, NSCD_VERSION); |
1064 | return; |
1065 | } |
1066 | |
1067 | /* Perform the SELinux check before we go on to the standard checks. */ |
1068 | if (selinux_enabled && nscd_request_avc_has_perm (fd, req: req->type) != 0) |
1069 | { |
1070 | if (debug_level > 0) |
1071 | { |
1072 | #ifdef SO_PEERCRED |
1073 | char pbuf[sizeof ("/proc//exe" ) + 3 * sizeof (long int)]; |
1074 | # ifdef PATH_MAX |
1075 | char buf[PATH_MAX]; |
1076 | # else |
1077 | char buf[4096]; |
1078 | # endif |
1079 | |
1080 | snprintf (s: pbuf, maxlen: sizeof (pbuf), format: "/proc/%ld/exe" , (long int) pid); |
1081 | ssize_t n = readlink (path: pbuf, buf: buf, len: sizeof (buf) - 1); |
1082 | |
1083 | if (n <= 0) |
1084 | dbg_log (_("\ |
1085 | request from %ld not handled due to missing permission" ), (long int) pid); |
1086 | else |
1087 | { |
1088 | buf[n] = '\0'; |
1089 | dbg_log (_("\ |
1090 | request from '%s' [%ld] not handled due to missing permission" ), |
1091 | buf, (long int) pid); |
1092 | } |
1093 | #else |
1094 | dbg_log (_("request not handled due to missing permission" )); |
1095 | #endif |
1096 | } |
1097 | return; |
1098 | } |
1099 | |
1100 | struct database_dyn *db = reqinfo[req->type].db; |
1101 | |
1102 | /* See whether we can service the request from the cache. */ |
1103 | if (__builtin_expect (reqinfo[req->type].data_request, true)) |
1104 | { |
1105 | if (__builtin_expect (debug_level, 0) > 0) |
1106 | { |
1107 | if (req->type == GETHOSTBYADDR || req->type == GETHOSTBYADDRv6) |
1108 | { |
1109 | char buf[INET6_ADDRSTRLEN]; |
1110 | |
1111 | dbg_log (str: "\t%s (%s)" , serv2str[req->type], |
1112 | inet_ntop (af: req->type == GETHOSTBYADDR |
1113 | ? AF_INET : AF_INET6, |
1114 | cp: key, buf: buf, len: sizeof (buf))); |
1115 | } |
1116 | else |
1117 | dbg_log (str: "\t%s (%s)" , serv2str[req->type], (char *) key); |
1118 | } |
1119 | |
1120 | /* Is this service enabled? */ |
1121 | if (__glibc_unlikely (!db->enabled)) |
1122 | { |
1123 | /* No, sent the prepared record. */ |
1124 | if (TEMP_FAILURE_RETRY (send (fd, db->disabled_iov->iov_base, |
1125 | db->disabled_iov->iov_len, |
1126 | MSG_NOSIGNAL)) |
1127 | != (ssize_t) db->disabled_iov->iov_len |
1128 | && __builtin_expect (debug_level, 0) > 0) |
1129 | { |
1130 | /* We have problems sending the result. */ |
1131 | char buf[256]; |
1132 | dbg_log (_("cannot write result: %s" ), |
1133 | strerror_r (errno, buf: buf, buflen: sizeof (buf))); |
1134 | } |
1135 | |
1136 | return; |
1137 | } |
1138 | |
1139 | /* Be sure we can read the data. */ |
1140 | if (__glibc_unlikely (pthread_rwlock_tryrdlock (&db->lock) != 0)) |
1141 | { |
1142 | ++db->head->rdlockdelayed; |
1143 | pthread_rwlock_rdlock (rwlock: &db->lock); |
1144 | } |
1145 | |
1146 | /* See whether we can handle it from the cache. */ |
1147 | struct datahead *cached; |
1148 | cached = (struct datahead *) cache_search (req->type, key, len: req->key_len, |
1149 | table: db, owner: uid); |
1150 | if (cached != NULL) |
1151 | { |
1152 | /* Hurray it's in the cache. */ |
1153 | if (writeall (fd, buf: cached->data, len: cached->recsize) != cached->recsize |
1154 | && __glibc_unlikely (debug_level > 0)) |
1155 | { |
1156 | /* We have problems sending the result. */ |
1157 | char buf[256]; |
1158 | dbg_log (_("cannot write result: %s" ), |
1159 | strerror_r (errno, buf: buf, buflen: sizeof (buf))); |
1160 | } |
1161 | |
1162 | pthread_rwlock_unlock (rwlock: &db->lock); |
1163 | |
1164 | return; |
1165 | } |
1166 | |
1167 | pthread_rwlock_unlock (rwlock: &db->lock); |
1168 | } |
1169 | else if (__builtin_expect (debug_level, 0) > 0) |
1170 | { |
1171 | if (req->type == INVALIDATE) |
1172 | dbg_log (str: "\t%s (%s)" , serv2str[req->type], (char *) key); |
1173 | else |
1174 | dbg_log (str: "\t%s" , serv2str[req->type]); |
1175 | } |
1176 | |
1177 | /* Handle the request. */ |
1178 | switch (req->type) |
1179 | { |
1180 | case GETPWBYNAME: |
1181 | addpwbyname (db, fd, req, key, uid); |
1182 | break; |
1183 | |
1184 | case GETPWBYUID: |
1185 | addpwbyuid (db, fd, req, key, uid); |
1186 | break; |
1187 | |
1188 | case GETGRBYNAME: |
1189 | addgrbyname (db, fd, req, key, uid); |
1190 | break; |
1191 | |
1192 | case GETGRBYGID: |
1193 | addgrbygid (db, fd, req, key, uid); |
1194 | break; |
1195 | |
1196 | case GETHOSTBYNAME: |
1197 | addhstbyname (db, fd, req, key, uid); |
1198 | break; |
1199 | |
1200 | case GETHOSTBYNAMEv6: |
1201 | addhstbynamev6 (db, fd, req, key, uid); |
1202 | break; |
1203 | |
1204 | case GETHOSTBYADDR: |
1205 | addhstbyaddr (db, fd, req, key, uid); |
1206 | break; |
1207 | |
1208 | case GETHOSTBYADDRv6: |
1209 | addhstbyaddrv6 (db, fd, req, key, uid); |
1210 | break; |
1211 | |
1212 | case GETAI: |
1213 | addhstai (db, fd, req, key, uid); |
1214 | break; |
1215 | |
1216 | case INITGROUPS: |
1217 | addinitgroups (db, fd, req, key, uid); |
1218 | break; |
1219 | |
1220 | case GETSERVBYNAME: |
1221 | addservbyname (db, fd, req, key, uid); |
1222 | break; |
1223 | |
1224 | case GETSERVBYPORT: |
1225 | addservbyport (db, fd, req, key, uid); |
1226 | break; |
1227 | |
1228 | case GETNETGRENT: |
1229 | addgetnetgrent (db, fd, req, key, uid); |
1230 | break; |
1231 | |
1232 | case INNETGR: |
1233 | addinnetgr (db, fd, req, key, uid); |
1234 | break; |
1235 | |
1236 | case GETSTAT: |
1237 | case SHUTDOWN: |
1238 | case INVALIDATE: |
1239 | { |
1240 | /* Get the callers credentials. */ |
1241 | #ifdef SO_PEERCRED |
1242 | struct ucred caller; |
1243 | socklen_t optlen = sizeof (caller); |
1244 | |
1245 | if (getsockopt (fd: fd, SOL_SOCKET, SO_PEERCRED, optval: &caller, optlen: &optlen) < 0) |
1246 | { |
1247 | char buf[256]; |
1248 | |
1249 | dbg_log (_("error getting caller's id: %s" ), |
1250 | strerror_r (errno, buf: buf, buflen: sizeof (buf))); |
1251 | break; |
1252 | } |
1253 | |
1254 | uid = caller.uid; |
1255 | #else |
1256 | /* Some systems have no SO_PEERCRED implementation. They don't |
1257 | care about security so we don't as well. */ |
1258 | uid = 0; |
1259 | #endif |
1260 | } |
1261 | |
1262 | /* Accept shutdown, getstat and invalidate only from root. For |
1263 | the stat call also allow the user specified in the config file. */ |
1264 | if (req->type == GETSTAT) |
1265 | { |
1266 | if (uid == 0 || uid == stat_uid) |
1267 | send_stats (fd, dbs); |
1268 | } |
1269 | else if (uid == 0) |
1270 | { |
1271 | if (req->type == INVALIDATE) |
1272 | invalidate_cache (key, fd); |
1273 | else |
1274 | termination_handler (signum: 0); |
1275 | } |
1276 | break; |
1277 | |
1278 | case GETFDPW: |
1279 | case GETFDGR: |
1280 | case GETFDHST: |
1281 | case GETFDSERV: |
1282 | case GETFDNETGR: |
1283 | #ifdef SCM_RIGHTS |
1284 | send_ro_fd (db: reqinfo[req->type].db, key, fd); |
1285 | #endif |
1286 | break; |
1287 | |
1288 | default: |
1289 | /* Ignore the command, it's nothing we know. */ |
1290 | break; |
1291 | } |
1292 | } |
1293 | |
1294 | static char * |
1295 | read_cmdline (size_t *size) |
1296 | { |
1297 | int fd = open (file: "/proc/self/cmdline" , O_RDONLY); |
1298 | if (fd < 0) |
1299 | return NULL; |
1300 | size_t current = 0; |
1301 | size_t limit = 1024; |
1302 | char *buffer = malloc (size: limit); |
1303 | if (buffer == NULL) |
1304 | { |
1305 | close (fd: fd); |
1306 | errno = ENOMEM; |
1307 | return NULL; |
1308 | } |
1309 | while (1) |
1310 | { |
1311 | if (current == limit) |
1312 | { |
1313 | char *newptr; |
1314 | if (2 * limit < limit |
1315 | || (newptr = realloc (ptr: buffer, size: 2 * limit)) == NULL) |
1316 | { |
1317 | free (ptr: buffer); |
1318 | close (fd: fd); |
1319 | errno = ENOMEM; |
1320 | return NULL; |
1321 | } |
1322 | buffer = newptr; |
1323 | limit *= 2; |
1324 | } |
1325 | |
1326 | ssize_t n = TEMP_FAILURE_RETRY (read (fd, buffer + current, |
1327 | limit - current)); |
1328 | if (n == -1) |
1329 | { |
1330 | int e = errno; |
1331 | free (ptr: buffer); |
1332 | close (fd: fd); |
1333 | errno = e; |
1334 | return NULL; |
1335 | } |
1336 | if (n == 0) |
1337 | break; |
1338 | current += n; |
1339 | } |
1340 | |
1341 | close (fd: fd); |
1342 | *size = current; |
1343 | return buffer; |
1344 | } |
1345 | |
1346 | |
1347 | /* Restart the process. */ |
1348 | static void |
1349 | restart (void) |
1350 | { |
1351 | /* First determine the parameters. We do not use the parameters |
1352 | passed to main because then nscd would use the system libc after |
1353 | restarting even if it was started by a non-system dynamic linker |
1354 | during glibc testing. */ |
1355 | size_t readlen; |
1356 | char *cmdline = read_cmdline (size: &readlen); |
1357 | if (cmdline == NULL) |
1358 | { |
1359 | dbg_log (_("\ |
1360 | cannot open /proc/self/cmdline: %m; disabling paranoia mode" )); |
1361 | paranoia = 0; |
1362 | return; |
1363 | } |
1364 | |
1365 | /* Parse the command line. Worst case scenario: every two |
1366 | characters form one parameter (one character plus NUL). */ |
1367 | char **argv = alloca ((readlen / 2 + 1) * sizeof (argv[0])); |
1368 | int argc = 0; |
1369 | |
1370 | for (char *cp = cmdline; cp < cmdline + readlen;) |
1371 | { |
1372 | argv[argc++] = cp; |
1373 | cp = strchr (s: cp, c: '\0') + 1; |
1374 | } |
1375 | argv[argc] = NULL; |
1376 | |
1377 | /* Second, change back to the old user if we changed it. */ |
1378 | if (server_user != NULL) |
1379 | { |
1380 | if (setresuid (ruid: old_uid, euid: old_uid, suid: old_uid) != 0) |
1381 | { |
1382 | dbg_log (_("\ |
1383 | cannot change to old UID: %s; disabling paranoia mode" ), |
1384 | strerror (errno)); |
1385 | |
1386 | paranoia = 0; |
1387 | free (ptr: cmdline); |
1388 | return; |
1389 | } |
1390 | |
1391 | if (setresgid (rgid: old_gid, egid: old_gid, sgid: old_gid) != 0) |
1392 | { |
1393 | dbg_log (_("\ |
1394 | cannot change to old GID: %s; disabling paranoia mode" ), |
1395 | strerror (errno)); |
1396 | |
1397 | ignore_value (setuid (server_uid)); |
1398 | paranoia = 0; |
1399 | free (ptr: cmdline); |
1400 | return; |
1401 | } |
1402 | } |
1403 | |
1404 | /* Next change back to the old working directory. */ |
1405 | if (chdir (path: oldcwd) == -1) |
1406 | { |
1407 | dbg_log (_("\ |
1408 | cannot change to old working directory: %s; disabling paranoia mode" ), |
1409 | strerror (errno)); |
1410 | |
1411 | if (server_user != NULL) |
1412 | { |
1413 | ignore_value (setuid (server_uid)); |
1414 | ignore_value (setgid (server_gid)); |
1415 | } |
1416 | paranoia = 0; |
1417 | free (ptr: cmdline); |
1418 | return; |
1419 | } |
1420 | |
1421 | /* Synchronize memory. */ |
1422 | int32_t certainly[lastdb]; |
1423 | for (int cnt = 0; cnt < lastdb; ++cnt) |
1424 | if (dbs[cnt].enabled) |
1425 | { |
1426 | /* Make sure nobody keeps using the database. */ |
1427 | dbs[cnt].head->timestamp = 0; |
1428 | certainly[cnt] = dbs[cnt].head->nscd_certainly_running; |
1429 | dbs[cnt].head->nscd_certainly_running = 0; |
1430 | |
1431 | if (dbs[cnt].persistent) |
1432 | // XXX async OK? |
1433 | msync (addr: dbs[cnt].head, len: dbs[cnt].memsize, MS_ASYNC); |
1434 | } |
1435 | |
1436 | /* The preparations are done. */ |
1437 | #ifdef PATH_MAX |
1438 | char pathbuf[PATH_MAX]; |
1439 | #else |
1440 | char pathbuf[256]; |
1441 | #endif |
1442 | /* Try to exec the real nscd program so the process name (as reported |
1443 | in /proc/PID/status) will be 'nscd', but fall back to /proc/self/exe |
1444 | if readlink or the exec with the result of the readlink call fails. */ |
1445 | ssize_t n = readlink (path: "/proc/self/exe" , buf: pathbuf, len: sizeof (pathbuf) - 1); |
1446 | if (n != -1) |
1447 | { |
1448 | pathbuf[n] = '\0'; |
1449 | execv (path: pathbuf, argv: argv); |
1450 | } |
1451 | execv (path: "/proc/self/exe" , argv: argv); |
1452 | |
1453 | /* If we come here, we will never be able to re-exec. */ |
1454 | dbg_log (_("re-exec failed: %s; disabling paranoia mode" ), |
1455 | strerror (errno)); |
1456 | |
1457 | if (server_user != NULL) |
1458 | { |
1459 | ignore_value (setuid (server_uid)); |
1460 | ignore_value (setgid (server_gid)); |
1461 | } |
1462 | if (chdir (path: "/" ) != 0) |
1463 | dbg_log (_("cannot change current working directory to \"/\": %s" ), |
1464 | strerror (errno)); |
1465 | paranoia = 0; |
1466 | free (ptr: cmdline); |
1467 | |
1468 | /* Re-enable the databases. */ |
1469 | time_t now = time (NULL); |
1470 | for (int cnt = 0; cnt < lastdb; ++cnt) |
1471 | if (dbs[cnt].enabled) |
1472 | { |
1473 | dbs[cnt].head->timestamp = now; |
1474 | dbs[cnt].head->nscd_certainly_running = certainly[cnt]; |
1475 | } |
1476 | } |
1477 | |
1478 | |
1479 | /* List of file descriptors. */ |
1480 | struct fdlist |
1481 | { |
1482 | int fd; |
1483 | struct fdlist *next; |
1484 | }; |
1485 | /* Memory allocated for the list. */ |
1486 | static struct fdlist *fdlist; |
1487 | /* List of currently ready-to-read file descriptors. */ |
1488 | static struct fdlist *readylist; |
1489 | |
1490 | /* Conditional variable and mutex to signal availability of entries in |
1491 | READYLIST. The condvar is initialized dynamically since we might |
1492 | use a different clock depending on availability. */ |
1493 | static pthread_cond_t readylist_cond = PTHREAD_COND_INITIALIZER; |
1494 | static pthread_mutex_t readylist_lock = PTHREAD_MUTEX_INITIALIZER; |
1495 | |
1496 | /* The clock to use with the condvar. */ |
1497 | static clockid_t timeout_clock = CLOCK_REALTIME; |
1498 | |
1499 | /* Number of threads ready to handle the READYLIST. */ |
1500 | static unsigned long int nready; |
1501 | |
1502 | |
1503 | /* Function for the clean-up threads. */ |
1504 | static void * |
1505 | __attribute__ ((__noreturn__)) |
1506 | nscd_run_prune (void *p) |
1507 | { |
1508 | const long int my_number = (long int) p; |
1509 | assert (dbs[my_number].enabled); |
1510 | |
1511 | int dont_need_update = setup_thread (&dbs[my_number]); |
1512 | |
1513 | time_t now = time (NULL); |
1514 | |
1515 | /* We are running. */ |
1516 | dbs[my_number].head->timestamp = now; |
1517 | |
1518 | struct timespec prune_ts; |
1519 | if (__glibc_unlikely (clock_gettime (timeout_clock, &prune_ts) == -1)) |
1520 | /* Should never happen. */ |
1521 | abort (); |
1522 | |
1523 | /* Compute the initial timeout time. Prevent all the timers to go |
1524 | off at the same time by adding a db-based value. */ |
1525 | prune_ts.tv_sec += CACHE_PRUNE_INTERVAL + my_number; |
1526 | dbs[my_number].wakeup_time = now + CACHE_PRUNE_INTERVAL + my_number; |
1527 | |
1528 | pthread_mutex_t *prune_lock = &dbs[my_number].prune_lock; |
1529 | pthread_mutex_t *prune_run_lock = &dbs[my_number].prune_run_lock; |
1530 | pthread_cond_t *prune_cond = &dbs[my_number].prune_cond; |
1531 | |
1532 | pthread_mutex_lock (mutex: prune_lock); |
1533 | while (1) |
1534 | { |
1535 | /* Wait, but not forever. */ |
1536 | int e = 0; |
1537 | if (! dbs[my_number].clear_cache) |
1538 | e = pthread_cond_timedwait (cond: prune_cond, mutex: prune_lock, abstime: &prune_ts); |
1539 | assert (__builtin_expect (e == 0 || e == ETIMEDOUT, 1)); |
1540 | |
1541 | time_t next_wait; |
1542 | now = time (NULL); |
1543 | if (e == ETIMEDOUT || now >= dbs[my_number].wakeup_time |
1544 | || dbs[my_number].clear_cache) |
1545 | { |
1546 | /* We will determine the new timeout values based on the |
1547 | cache content. Should there be concurrent additions to |
1548 | the cache which are not accounted for in the cache |
1549 | pruning we want to know about it. Therefore set the |
1550 | timeout to the maximum. It will be decreased when adding |
1551 | new entries to the cache, if necessary. */ |
1552 | dbs[my_number].wakeup_time = MAX_TIMEOUT_VALUE; |
1553 | |
1554 | /* Unconditionally reset the flag. */ |
1555 | time_t prune_now = dbs[my_number].clear_cache ? LONG_MAX : now; |
1556 | dbs[my_number].clear_cache = 0; |
1557 | |
1558 | pthread_mutex_unlock (mutex: prune_lock); |
1559 | |
1560 | /* We use a separate lock for running the prune function (instead |
1561 | of keeping prune_lock locked) because this enables concurrent |
1562 | invocations of cache_add which might modify the timeout value. */ |
1563 | pthread_mutex_lock (mutex: prune_run_lock); |
1564 | next_wait = prune_cache (table: &dbs[my_number], now: prune_now, fd: -1); |
1565 | pthread_mutex_unlock (mutex: prune_run_lock); |
1566 | |
1567 | next_wait = MAX (next_wait, CACHE_PRUNE_INTERVAL); |
1568 | /* If clients cannot determine for sure whether nscd is running |
1569 | we need to wake up occasionally to update the timestamp. |
1570 | Wait 90% of the update period. */ |
1571 | #define UPDATE_MAPPING_TIMEOUT (MAPPING_TIMEOUT * 9 / 10) |
1572 | if (__glibc_unlikely (! dont_need_update)) |
1573 | { |
1574 | next_wait = MIN (UPDATE_MAPPING_TIMEOUT, next_wait); |
1575 | dbs[my_number].head->timestamp = now; |
1576 | } |
1577 | |
1578 | pthread_mutex_lock (mutex: prune_lock); |
1579 | |
1580 | /* Make it known when we will wake up again. */ |
1581 | if (now + next_wait < dbs[my_number].wakeup_time) |
1582 | dbs[my_number].wakeup_time = now + next_wait; |
1583 | else |
1584 | next_wait = dbs[my_number].wakeup_time - now; |
1585 | } |
1586 | else |
1587 | /* The cache was just pruned. Do not do it again now. Just |
1588 | use the new timeout value. */ |
1589 | next_wait = dbs[my_number].wakeup_time - now; |
1590 | |
1591 | if (clock_gettime (clock_id: timeout_clock, tp: &prune_ts) == -1) |
1592 | /* Should never happen. */ |
1593 | abort (); |
1594 | |
1595 | /* Compute next timeout time. */ |
1596 | prune_ts.tv_sec += next_wait; |
1597 | } |
1598 | } |
1599 | |
1600 | |
1601 | /* This is the main loop. It is replicated in different threads but |
1602 | the use of the ready list makes sure only one thread handles an |
1603 | incoming connection. */ |
1604 | static void * |
1605 | __attribute__ ((__noreturn__)) |
1606 | nscd_run_worker (void *p) |
1607 | { |
1608 | char buf[256]; |
1609 | |
1610 | /* Initial locking. */ |
1611 | pthread_mutex_lock (mutex: &readylist_lock); |
1612 | |
1613 | /* One more thread available. */ |
1614 | ++nready; |
1615 | |
1616 | while (1) |
1617 | { |
1618 | while (readylist == NULL) |
1619 | pthread_cond_wait (cond: &readylist_cond, mutex: &readylist_lock); |
1620 | |
1621 | struct fdlist *it = readylist->next; |
1622 | if (readylist->next == readylist) |
1623 | /* Just one entry on the list. */ |
1624 | readylist = NULL; |
1625 | else |
1626 | readylist->next = it->next; |
1627 | |
1628 | /* Extract the information and mark the record ready to be used |
1629 | again. */ |
1630 | int fd = it->fd; |
1631 | it->next = NULL; |
1632 | |
1633 | /* One more thread available. */ |
1634 | --nready; |
1635 | |
1636 | /* We are done with the list. */ |
1637 | pthread_mutex_unlock (mutex: &readylist_lock); |
1638 | |
1639 | /* Now read the request. */ |
1640 | request_header req; |
1641 | if (__builtin_expect (TEMP_FAILURE_RETRY (read (fd, &req, sizeof (req))) |
1642 | != sizeof (req), 0)) |
1643 | { |
1644 | /* We failed to read data. Note that this also might mean we |
1645 | failed because we would have blocked. */ |
1646 | if (debug_level > 0) |
1647 | dbg_log (_("short read while reading request: %s" ), |
1648 | strerror_r (errno, buf: buf, buflen: sizeof (buf))); |
1649 | goto close_and_out; |
1650 | } |
1651 | |
1652 | /* Check whether this is a valid request type. */ |
1653 | if (req.type < GETPWBYNAME || req.type >= LASTREQ) |
1654 | goto close_and_out; |
1655 | |
1656 | /* Some systems have no SO_PEERCRED implementation. They don't |
1657 | care about security so we don't as well. */ |
1658 | uid_t uid = -1; |
1659 | #ifdef SO_PEERCRED |
1660 | pid_t pid = 0; |
1661 | |
1662 | if (__glibc_unlikely (debug_level > 0)) |
1663 | { |
1664 | struct ucred caller; |
1665 | socklen_t optlen = sizeof (caller); |
1666 | |
1667 | if (getsockopt (fd: fd, SOL_SOCKET, SO_PEERCRED, optval: &caller, optlen: &optlen) == 0) |
1668 | pid = caller.pid; |
1669 | } |
1670 | #else |
1671 | const pid_t pid = 0; |
1672 | #endif |
1673 | |
1674 | /* It should not be possible to crash the nscd with a silly |
1675 | request (i.e., a terribly large key). We limit the size to 1kb. */ |
1676 | if (__builtin_expect (req.key_len, 1) < 0 |
1677 | || __builtin_expect (req.key_len, 1) > MAXKEYLEN) |
1678 | { |
1679 | if (debug_level > 0) |
1680 | dbg_log (_("key length in request too long: %d" ), req.key_len); |
1681 | } |
1682 | else |
1683 | { |
1684 | /* Get the key. */ |
1685 | char keybuf[MAXKEYLEN + 1]; |
1686 | |
1687 | if (__builtin_expect (TEMP_FAILURE_RETRY (read (fd, keybuf, |
1688 | req.key_len)) |
1689 | != req.key_len, 0)) |
1690 | { |
1691 | /* Again, this can also mean we would have blocked. */ |
1692 | if (debug_level > 0) |
1693 | dbg_log (_("short read while reading request key: %s" ), |
1694 | strerror_r (errno, buf: buf, buflen: sizeof (buf))); |
1695 | goto close_and_out; |
1696 | } |
1697 | keybuf[req.key_len] = '\0'; |
1698 | |
1699 | if (__builtin_expect (debug_level, 0) > 0) |
1700 | { |
1701 | #ifdef SO_PEERCRED |
1702 | if (pid != 0) |
1703 | dbg_log (_("\ |
1704 | handle_request: request received (Version = %d) from PID %ld" ), |
1705 | req.version, (long int) pid); |
1706 | else |
1707 | #endif |
1708 | dbg_log (_("\ |
1709 | handle_request: request received (Version = %d)" ), req.version); |
1710 | } |
1711 | |
1712 | /* Phew, we got all the data, now process it. */ |
1713 | handle_request (fd, req: &req, key: keybuf, uid, pid); |
1714 | } |
1715 | |
1716 | close_and_out: |
1717 | /* We are done. */ |
1718 | close (fd: fd); |
1719 | |
1720 | /* Re-locking. */ |
1721 | pthread_mutex_lock (mutex: &readylist_lock); |
1722 | |
1723 | /* One more thread available. */ |
1724 | ++nready; |
1725 | } |
1726 | /* NOTREACHED */ |
1727 | } |
1728 | |
1729 | |
1730 | static unsigned int nconns; |
1731 | |
1732 | static void |
1733 | fd_ready (int fd) |
1734 | { |
1735 | pthread_mutex_lock (mutex: &readylist_lock); |
1736 | |
1737 | /* Find an empty entry in FDLIST. */ |
1738 | size_t inner; |
1739 | for (inner = 0; inner < nconns; ++inner) |
1740 | if (fdlist[inner].next == NULL) |
1741 | break; |
1742 | assert (inner < nconns); |
1743 | |
1744 | fdlist[inner].fd = fd; |
1745 | |
1746 | if (readylist == NULL) |
1747 | readylist = fdlist[inner].next = &fdlist[inner]; |
1748 | else |
1749 | { |
1750 | fdlist[inner].next = readylist->next; |
1751 | readylist = readylist->next = &fdlist[inner]; |
1752 | } |
1753 | |
1754 | bool do_signal = true; |
1755 | if (__glibc_unlikely (nready == 0)) |
1756 | { |
1757 | ++client_queued; |
1758 | do_signal = false; |
1759 | |
1760 | /* Try to start another thread to help out. */ |
1761 | pthread_t th; |
1762 | if (nthreads < max_nthreads |
1763 | && pthread_create (newthread: &th, attr: &attr, start_routine: nscd_run_worker, |
1764 | arg: (void *) (long int) nthreads) == 0) |
1765 | { |
1766 | /* We got another thread. */ |
1767 | ++nthreads; |
1768 | /* The new thread might need a kick. */ |
1769 | do_signal = true; |
1770 | } |
1771 | |
1772 | } |
1773 | |
1774 | pthread_mutex_unlock (mutex: &readylist_lock); |
1775 | |
1776 | /* Tell one of the worker threads there is work to do. */ |
1777 | if (do_signal) |
1778 | pthread_cond_signal (cond: &readylist_cond); |
1779 | } |
1780 | |
1781 | |
1782 | /* Check whether restarting should happen. */ |
1783 | static bool |
1784 | restart_p (time_t now) |
1785 | { |
1786 | return (paranoia && readylist == NULL && nready == nthreads |
1787 | && now >= restart_time); |
1788 | } |
1789 | |
1790 | |
1791 | /* Array for times a connection was accepted. */ |
1792 | static time_t *starttime; |
1793 | |
1794 | #ifdef HAVE_INOTIFY |
1795 | /* Inotify event for changed file. */ |
1796 | union __inev |
1797 | { |
1798 | struct inotify_event i; |
1799 | # ifndef PATH_MAX |
1800 | # define PATH_MAX 1024 |
1801 | # endif |
1802 | char buf[sizeof (struct inotify_event) + PATH_MAX]; |
1803 | }; |
1804 | |
1805 | /* Returns 0 if the file is there otherwise -1. */ |
1806 | int |
1807 | check_file (struct traced_file *finfo) |
1808 | { |
1809 | struct stat64 st; |
1810 | /* We could check mtime and if different re-add |
1811 | the watches, and invalidate the database, but we |
1812 | don't because we are called from inotify_check_files |
1813 | which should be doing that work. If sufficient inotify |
1814 | events were lost then the next pruning or invalidation |
1815 | will do the stat and mtime check. We don't do it here to |
1816 | keep the logic simple. */ |
1817 | if (stat64 (file: finfo->fname, buf: &st) < 0) |
1818 | return -1; |
1819 | return 0; |
1820 | } |
1821 | |
1822 | /* Process the inotify event in INEV. If the event matches any of the files |
1823 | registered with a database then mark that database as requiring its cache |
1824 | to be cleared. We indicate the cache needs clearing by setting |
1825 | TO_CLEAR[DBCNT] to true for the matching database. */ |
1826 | static void |
1827 | inotify_check_files (bool *to_clear, union __inev *inev) |
1828 | { |
1829 | /* Check which of the files changed. */ |
1830 | for (size_t dbcnt = 0; dbcnt < lastdb; ++dbcnt) |
1831 | { |
1832 | struct traced_file *finfo = dbs[dbcnt].traced_files; |
1833 | |
1834 | while (finfo != NULL) |
1835 | { |
1836 | /* The configuration file was moved or deleted. |
1837 | We stop watching it at that point, and reinitialize. */ |
1838 | if (finfo->inotify_descr[TRACED_FILE] == inev->i.wd |
1839 | && ((inev->i.mask & IN_MOVE_SELF) |
1840 | || (inev->i.mask & IN_DELETE_SELF) |
1841 | || (inev->i.mask & IN_IGNORED))) |
1842 | { |
1843 | int ret; |
1844 | bool moved = (inev->i.mask & IN_MOVE_SELF) != 0; |
1845 | |
1846 | if (check_file (finfo) == 0) |
1847 | { |
1848 | dbg_log (_("ignored inotify event for `%s` (file exists)" ), |
1849 | finfo->fname); |
1850 | return; |
1851 | } |
1852 | |
1853 | dbg_log (_("monitored file `%s` was %s, removing watch" ), |
1854 | finfo->fname, moved ? "moved" : "deleted" ); |
1855 | /* File was moved out, remove the watch. Watches are |
1856 | automatically removed when the file is deleted. */ |
1857 | if (moved) |
1858 | { |
1859 | ret = inotify_rm_watch (fd: inotify_fd, wd: inev->i.wd); |
1860 | if (ret < 0) |
1861 | dbg_log (_("failed to remove file watch `%s`: %s" ), |
1862 | finfo->fname, strerror (errno)); |
1863 | } |
1864 | finfo->inotify_descr[TRACED_FILE] = -1; |
1865 | to_clear[dbcnt] = true; |
1866 | if (finfo->call_res_init) |
1867 | res_init (); |
1868 | return; |
1869 | } |
1870 | /* The configuration file was open for writing and has just closed. |
1871 | We reset the cache and reinitialize. */ |
1872 | if (finfo->inotify_descr[TRACED_FILE] == inev->i.wd |
1873 | && inev->i.mask & IN_CLOSE_WRITE) |
1874 | { |
1875 | /* Mark cache as needing to be cleared and reinitialize. */ |
1876 | dbg_log (_("monitored file `%s` was written to" ), finfo->fname); |
1877 | to_clear[dbcnt] = true; |
1878 | if (finfo->call_res_init) |
1879 | res_init (); |
1880 | return; |
1881 | } |
1882 | /* The parent directory was moved or deleted. We trigger one last |
1883 | invalidation. At the next pruning or invalidation we may add |
1884 | this watch back if the file is present again. */ |
1885 | if (finfo->inotify_descr[TRACED_DIR] == inev->i.wd |
1886 | && ((inev->i.mask & IN_DELETE_SELF) |
1887 | || (inev->i.mask & IN_MOVE_SELF) |
1888 | || (inev->i.mask & IN_IGNORED))) |
1889 | { |
1890 | bool moved = (inev->i.mask & IN_MOVE_SELF) != 0; |
1891 | /* The directory watch may have already been removed |
1892 | but we don't know so we just remove it again and |
1893 | ignore the error. Then we remove the file watch. |
1894 | Note: watches are automatically removed for deleted |
1895 | files. */ |
1896 | if (moved) |
1897 | inotify_rm_watch (fd: inotify_fd, wd: inev->i.wd); |
1898 | if (finfo->inotify_descr[TRACED_FILE] != -1) |
1899 | { |
1900 | dbg_log (_("monitored parent directory `%s` was %s, removing watch on `%s`" ), |
1901 | finfo->dname, moved ? "moved" : "deleted" , finfo->fname); |
1902 | if (inotify_rm_watch (fd: inotify_fd, wd: finfo->inotify_descr[TRACED_FILE]) < 0) |
1903 | dbg_log (_("failed to remove file watch `%s`: %s" ), |
1904 | finfo->dname, strerror (errno)); |
1905 | } |
1906 | finfo->inotify_descr[TRACED_FILE] = -1; |
1907 | finfo->inotify_descr[TRACED_DIR] = -1; |
1908 | to_clear[dbcnt] = true; |
1909 | if (finfo->call_res_init) |
1910 | res_init (); |
1911 | /* Continue to the next entry since this might be the |
1912 | parent directory for multiple registered files and |
1913 | we want to remove watches for all registered files. */ |
1914 | continue; |
1915 | } |
1916 | /* The parent directory had a create or moved to event. */ |
1917 | if (finfo->inotify_descr[TRACED_DIR] == inev->i.wd |
1918 | && ((inev->i.mask & IN_MOVED_TO) |
1919 | || (inev->i.mask & IN_CREATE)) |
1920 | && strcmp (s1: inev->i.name, s2: finfo->sfname) == 0) |
1921 | { |
1922 | /* We detected a directory change. We look for the creation |
1923 | of the file we are tracking or the move of the same file |
1924 | into the directory. */ |
1925 | int ret; |
1926 | dbg_log (_("monitored file `%s` was %s, adding watch" ), |
1927 | finfo->fname, |
1928 | inev->i.mask & IN_CREATE ? "created" : "moved into place" ); |
1929 | /* File was moved in or created. Regenerate the watch. */ |
1930 | if (finfo->inotify_descr[TRACED_FILE] != -1) |
1931 | inotify_rm_watch (fd: inotify_fd, |
1932 | wd: finfo->inotify_descr[TRACED_FILE]); |
1933 | |
1934 | ret = inotify_add_watch (fd: inotify_fd, |
1935 | name: finfo->fname, |
1936 | TRACED_FILE_MASK); |
1937 | if (ret < 0) |
1938 | dbg_log (_("failed to add file watch `%s`: %s" ), |
1939 | finfo->fname, strerror (errno)); |
1940 | |
1941 | finfo->inotify_descr[TRACED_FILE] = ret; |
1942 | |
1943 | /* The file is new or moved so mark cache as needing to |
1944 | be cleared and reinitialize. */ |
1945 | to_clear[dbcnt] = true; |
1946 | if (finfo->call_res_init) |
1947 | res_init (); |
1948 | |
1949 | /* Done re-adding the watch. Don't return, we may still |
1950 | have other files in this same directory, same watch |
1951 | descriptor, and need to process them. */ |
1952 | } |
1953 | /* Other events are ignored, and we move on to the next file. */ |
1954 | finfo = finfo->next; |
1955 | } |
1956 | } |
1957 | } |
1958 | |
1959 | /* If an entry in the array of booleans TO_CLEAR is TRUE then clear the cache |
1960 | for the associated database, otherwise do nothing. The TO_CLEAR array must |
1961 | have LASTDB entries. */ |
1962 | static inline void |
1963 | clear_db_cache (bool *to_clear) |
1964 | { |
1965 | for (size_t dbcnt = 0; dbcnt < lastdb; ++dbcnt) |
1966 | if (to_clear[dbcnt]) |
1967 | { |
1968 | pthread_mutex_lock (mutex: &dbs[dbcnt].prune_lock); |
1969 | dbs[dbcnt].clear_cache = 1; |
1970 | pthread_mutex_unlock (mutex: &dbs[dbcnt].prune_lock); |
1971 | pthread_cond_signal (cond: &dbs[dbcnt].prune_cond); |
1972 | } |
1973 | } |
1974 | |
1975 | int |
1976 | handle_inotify_events (void) |
1977 | { |
1978 | bool to_clear[lastdb] = { false, }; |
1979 | union __inev inev; |
1980 | |
1981 | /* Read all inotify events for files registered via |
1982 | register_traced_file(). */ |
1983 | while (1) |
1984 | { |
1985 | /* Potentially read multiple events into buf. */ |
1986 | ssize_t nb = TEMP_FAILURE_RETRY (read (inotify_fd, |
1987 | &inev.buf, |
1988 | sizeof (inev))); |
1989 | if (nb < (ssize_t) sizeof (struct inotify_event)) |
1990 | { |
1991 | /* Not even 1 event. */ |
1992 | if (__glibc_unlikely (nb == -1 && errno != EAGAIN)) |
1993 | return -1; |
1994 | /* Done reading events that are ready. */ |
1995 | break; |
1996 | } |
1997 | /* Process all events. The normal inotify interface delivers |
1998 | complete events on a read and never a partial event. */ |
1999 | char *eptr = &inev.buf[0]; |
2000 | ssize_t count; |
2001 | while (1) |
2002 | { |
2003 | /* Check which of the files changed. */ |
2004 | inotify_check_files (to_clear, inev: &inev); |
2005 | count = sizeof (struct inotify_event) + inev.i.len; |
2006 | eptr += count; |
2007 | nb -= count; |
2008 | if (nb >= (ssize_t) sizeof (struct inotify_event)) |
2009 | memcpy (dest: &inev, src: eptr, n: nb); |
2010 | else |
2011 | break; |
2012 | } |
2013 | continue; |
2014 | } |
2015 | /* Actually perform the cache clearing. */ |
2016 | clear_db_cache (to_clear); |
2017 | return 0; |
2018 | } |
2019 | |
2020 | #endif |
2021 | |
2022 | static void |
2023 | __attribute__ ((__noreturn__)) |
2024 | main_loop_poll (void) |
2025 | { |
2026 | struct pollfd *conns = (struct pollfd *) xmalloc (n: nconns |
2027 | * sizeof (conns[0])); |
2028 | |
2029 | conns[0].fd = sock; |
2030 | conns[0].events = POLLRDNORM; |
2031 | size_t nused = 1; |
2032 | size_t firstfree = 1; |
2033 | |
2034 | #ifdef HAVE_INOTIFY |
2035 | if (inotify_fd != -1) |
2036 | { |
2037 | conns[1].fd = inotify_fd; |
2038 | conns[1].events = POLLRDNORM; |
2039 | nused = 2; |
2040 | firstfree = 2; |
2041 | } |
2042 | #endif |
2043 | |
2044 | #ifdef HAVE_NETLINK |
2045 | size_t idx_nl_status_fd = 0; |
2046 | if (nl_status_fd != -1) |
2047 | { |
2048 | idx_nl_status_fd = nused; |
2049 | conns[nused].fd = nl_status_fd; |
2050 | conns[nused].events = POLLRDNORM; |
2051 | ++nused; |
2052 | firstfree = nused; |
2053 | } |
2054 | #endif |
2055 | |
2056 | while (1) |
2057 | { |
2058 | /* Wait for any event. We wait at most a couple of seconds so |
2059 | that we can check whether we should close any of the accepted |
2060 | connections since we have not received a request. */ |
2061 | #define MAX_ACCEPT_TIMEOUT 30 |
2062 | #define MIN_ACCEPT_TIMEOUT 5 |
2063 | #define MAIN_THREAD_TIMEOUT \ |
2064 | (MAX_ACCEPT_TIMEOUT * 1000 \ |
2065 | - ((MAX_ACCEPT_TIMEOUT - MIN_ACCEPT_TIMEOUT) * 1000 * nused) / (2 * nconns)) |
2066 | |
2067 | int n = poll (fds: conns, nfds: nused, MAIN_THREAD_TIMEOUT); |
2068 | |
2069 | time_t now = time (NULL); |
2070 | |
2071 | /* If there is a descriptor ready for reading or there is a new |
2072 | connection, process this now. */ |
2073 | if (n > 0) |
2074 | { |
2075 | if (conns[0].revents != 0) |
2076 | { |
2077 | /* We have a new incoming connection. Accept the connection. */ |
2078 | int fd = TEMP_FAILURE_RETRY (accept4 (sock, NULL, NULL, |
2079 | SOCK_NONBLOCK)); |
2080 | |
2081 | /* Use the descriptor if we have not reached the limit. */ |
2082 | if (fd >= 0) |
2083 | { |
2084 | if (firstfree < nconns) |
2085 | { |
2086 | conns[firstfree].fd = fd; |
2087 | conns[firstfree].events = POLLRDNORM; |
2088 | starttime[firstfree] = now; |
2089 | if (firstfree >= nused) |
2090 | nused = firstfree + 1; |
2091 | |
2092 | do |
2093 | ++firstfree; |
2094 | while (firstfree < nused && conns[firstfree].fd != -1); |
2095 | } |
2096 | else |
2097 | /* We cannot use the connection so close it. */ |
2098 | close (fd: fd); |
2099 | } |
2100 | |
2101 | --n; |
2102 | } |
2103 | |
2104 | size_t first = 1; |
2105 | #ifdef HAVE_INOTIFY |
2106 | if (inotify_fd != -1 && conns[1].fd == inotify_fd) |
2107 | { |
2108 | if (conns[1].revents != 0) |
2109 | { |
2110 | int ret; |
2111 | ret = handle_inotify_events (); |
2112 | if (ret == -1) |
2113 | { |
2114 | /* Something went wrong when reading the inotify |
2115 | data. Better disable inotify. */ |
2116 | dbg_log (_("disabled inotify-based monitoring after read error %d" ), errno); |
2117 | conns[1].fd = -1; |
2118 | firstfree = 1; |
2119 | if (nused == 2) |
2120 | nused = 1; |
2121 | close (fd: inotify_fd); |
2122 | inotify_fd = -1; |
2123 | } |
2124 | --n; |
2125 | } |
2126 | |
2127 | first = 2; |
2128 | } |
2129 | #endif |
2130 | |
2131 | #ifdef HAVE_NETLINK |
2132 | if (idx_nl_status_fd != 0 && conns[idx_nl_status_fd].revents != 0) |
2133 | { |
2134 | char buf[4096]; |
2135 | /* Read all the data. We do not interpret it here. */ |
2136 | while (TEMP_FAILURE_RETRY (read (nl_status_fd, buf, |
2137 | sizeof (buf))) != -1) |
2138 | ; |
2139 | |
2140 | dbs[hstdb].head->extra_data[NSCD_HST_IDX_CONF_TIMESTAMP] |
2141 | = __bump_nl_timestamp (); |
2142 | } |
2143 | #endif |
2144 | |
2145 | for (size_t cnt = first; cnt < nused && n > 0; ++cnt) |
2146 | if (conns[cnt].revents != 0) |
2147 | { |
2148 | fd_ready (fd: conns[cnt].fd); |
2149 | |
2150 | /* Clean up the CONNS array. */ |
2151 | conns[cnt].fd = -1; |
2152 | if (cnt < firstfree) |
2153 | firstfree = cnt; |
2154 | if (cnt == nused - 1) |
2155 | do |
2156 | --nused; |
2157 | while (conns[nused - 1].fd == -1); |
2158 | |
2159 | --n; |
2160 | } |
2161 | } |
2162 | |
2163 | /* Now find entries which have timed out. */ |
2164 | assert (nused > 0); |
2165 | |
2166 | /* We make the timeout length depend on the number of file |
2167 | descriptors currently used. */ |
2168 | #define ACCEPT_TIMEOUT \ |
2169 | (MAX_ACCEPT_TIMEOUT \ |
2170 | - ((MAX_ACCEPT_TIMEOUT - MIN_ACCEPT_TIMEOUT) * nused) / nconns) |
2171 | time_t laststart = now - ACCEPT_TIMEOUT; |
2172 | |
2173 | for (size_t cnt = nused - 1; cnt > 0; --cnt) |
2174 | { |
2175 | if (conns[cnt].fd != -1 && starttime[cnt] < laststart) |
2176 | { |
2177 | /* Remove the entry, it timed out. */ |
2178 | (void) close (fd: conns[cnt].fd); |
2179 | conns[cnt].fd = -1; |
2180 | |
2181 | if (cnt < firstfree) |
2182 | firstfree = cnt; |
2183 | if (cnt == nused - 1) |
2184 | do |
2185 | --nused; |
2186 | while (conns[nused - 1].fd == -1); |
2187 | } |
2188 | } |
2189 | |
2190 | if (restart_p (now)) |
2191 | restart (); |
2192 | } |
2193 | } |
2194 | |
2195 | |
2196 | #ifdef HAVE_EPOLL |
2197 | static void |
2198 | main_loop_epoll (int efd) |
2199 | { |
2200 | struct epoll_event ev = { 0, }; |
2201 | int nused = 1; |
2202 | size_t highest = 0; |
2203 | |
2204 | /* Add the socket. */ |
2205 | ev.events = EPOLLRDNORM; |
2206 | ev.data.fd = sock; |
2207 | if (epoll_ctl (epfd: efd, EPOLL_CTL_ADD, fd: sock, event: &ev) == -1) |
2208 | /* We cannot use epoll. */ |
2209 | return; |
2210 | |
2211 | # ifdef HAVE_INOTIFY |
2212 | if (inotify_fd != -1) |
2213 | { |
2214 | ev.events = EPOLLRDNORM; |
2215 | ev.data.fd = inotify_fd; |
2216 | if (epoll_ctl (epfd: efd, EPOLL_CTL_ADD, fd: inotify_fd, event: &ev) == -1) |
2217 | /* We cannot use epoll. */ |
2218 | return; |
2219 | nused = 2; |
2220 | } |
2221 | # endif |
2222 | |
2223 | # ifdef HAVE_NETLINK |
2224 | if (nl_status_fd != -1) |
2225 | { |
2226 | ev.events = EPOLLRDNORM; |
2227 | ev.data.fd = nl_status_fd; |
2228 | if (epoll_ctl (epfd: efd, EPOLL_CTL_ADD, fd: nl_status_fd, event: &ev) == -1) |
2229 | /* We cannot use epoll. */ |
2230 | return; |
2231 | } |
2232 | # endif |
2233 | |
2234 | while (1) |
2235 | { |
2236 | struct epoll_event revs[100]; |
2237 | # define nrevs (sizeof (revs) / sizeof (revs[0])) |
2238 | |
2239 | int n = epoll_wait (epfd: efd, events: revs, nrevs, MAIN_THREAD_TIMEOUT); |
2240 | |
2241 | time_t now = time (NULL); |
2242 | |
2243 | for (int cnt = 0; cnt < n; ++cnt) |
2244 | if (revs[cnt].data.fd == sock) |
2245 | { |
2246 | /* A new connection. */ |
2247 | int fd = TEMP_FAILURE_RETRY (accept4 (sock, NULL, NULL, |
2248 | SOCK_NONBLOCK)); |
2249 | |
2250 | /* Use the descriptor if we have not reached the limit. */ |
2251 | if (fd >= 0) |
2252 | { |
2253 | /* Try to add the new descriptor. */ |
2254 | ev.data.fd = fd; |
2255 | if (fd >= nconns |
2256 | || epoll_ctl (epfd: efd, EPOLL_CTL_ADD, fd: fd, event: &ev) == -1) |
2257 | /* The descriptor is too large or something went |
2258 | wrong. Close the descriptor. */ |
2259 | close (fd: fd); |
2260 | else |
2261 | { |
2262 | /* Remember when we accepted the connection. */ |
2263 | starttime[fd] = now; |
2264 | |
2265 | if (fd > highest) |
2266 | highest = fd; |
2267 | |
2268 | ++nused; |
2269 | } |
2270 | } |
2271 | } |
2272 | # ifdef HAVE_INOTIFY |
2273 | else if (revs[cnt].data.fd == inotify_fd) |
2274 | { |
2275 | int ret; |
2276 | ret = handle_inotify_events (); |
2277 | if (ret == -1) |
2278 | { |
2279 | /* Something went wrong when reading the inotify |
2280 | data. Better disable inotify. */ |
2281 | dbg_log (_("disabled inotify-based monitoring after read error %d" ), errno); |
2282 | (void) epoll_ctl (epfd: efd, EPOLL_CTL_DEL, fd: inotify_fd, NULL); |
2283 | close (fd: inotify_fd); |
2284 | inotify_fd = -1; |
2285 | break; |
2286 | } |
2287 | } |
2288 | # endif |
2289 | # ifdef HAVE_NETLINK |
2290 | else if (revs[cnt].data.fd == nl_status_fd) |
2291 | { |
2292 | char buf[4096]; |
2293 | /* Read all the data. We do not interpret it here. */ |
2294 | while (TEMP_FAILURE_RETRY (read (nl_status_fd, buf, |
2295 | sizeof (buf))) != -1) |
2296 | ; |
2297 | |
2298 | dbs[hstdb].head->extra_data[NSCD_HST_IDX_CONF_TIMESTAMP] |
2299 | = __bump_nl_timestamp (); |
2300 | } |
2301 | # endif |
2302 | else |
2303 | { |
2304 | /* Remove the descriptor from the epoll descriptor. */ |
2305 | (void) epoll_ctl (epfd: efd, EPOLL_CTL_DEL, fd: revs[cnt].data.fd, NULL); |
2306 | |
2307 | /* Get a worker to handle the request. */ |
2308 | fd_ready (fd: revs[cnt].data.fd); |
2309 | |
2310 | /* Reset the time. */ |
2311 | starttime[revs[cnt].data.fd] = 0; |
2312 | if (revs[cnt].data.fd == highest) |
2313 | do |
2314 | --highest; |
2315 | while (highest > 0 && starttime[highest] == 0); |
2316 | |
2317 | --nused; |
2318 | } |
2319 | |
2320 | /* Now look for descriptors for accepted connections which have |
2321 | no reply in too long of a time. */ |
2322 | time_t laststart = now - ACCEPT_TIMEOUT; |
2323 | assert (starttime[sock] == 0); |
2324 | # ifdef HAVE_INOTIFY |
2325 | assert (inotify_fd == -1 || starttime[inotify_fd] == 0); |
2326 | # endif |
2327 | assert (nl_status_fd == -1 || starttime[nl_status_fd] == 0); |
2328 | for (int cnt = highest; cnt > STDERR_FILENO; --cnt) |
2329 | if (starttime[cnt] != 0 && starttime[cnt] < laststart) |
2330 | { |
2331 | /* We are waiting for this one for too long. Close it. */ |
2332 | (void) epoll_ctl (epfd: efd, EPOLL_CTL_DEL, fd: cnt, NULL); |
2333 | |
2334 | (void) close (fd: cnt); |
2335 | |
2336 | starttime[cnt] = 0; |
2337 | if (cnt == highest) |
2338 | --highest; |
2339 | } |
2340 | else if (cnt != sock && starttime[cnt] == 0 && cnt == highest) |
2341 | --highest; |
2342 | |
2343 | if (restart_p (now)) |
2344 | restart (); |
2345 | } |
2346 | } |
2347 | #endif |
2348 | |
2349 | |
2350 | /* Start all the threads we want. The initial process is thread no. 1. */ |
2351 | void |
2352 | start_threads (void) |
2353 | { |
2354 | /* Initialize the conditional variable we will use. The only |
2355 | non-standard attribute we might use is the clock selection. */ |
2356 | pthread_condattr_t condattr; |
2357 | pthread_condattr_init (attr: &condattr); |
2358 | |
2359 | #if defined _POSIX_CLOCK_SELECTION && _POSIX_CLOCK_SELECTION >= 0 \ |
2360 | && defined _POSIX_MONOTONIC_CLOCK && _POSIX_MONOTONIC_CLOCK >= 0 |
2361 | /* Determine whether the monotonous clock is available. */ |
2362 | struct timespec dummy; |
2363 | # if _POSIX_MONOTONIC_CLOCK == 0 |
2364 | if (sysconf (_SC_MONOTONIC_CLOCK) > 0) |
2365 | # endif |
2366 | # if _POSIX_CLOCK_SELECTION == 0 |
2367 | if (sysconf (_SC_CLOCK_SELECTION) > 0) |
2368 | # endif |
2369 | if (clock_getres (CLOCK_MONOTONIC, res: &dummy) == 0 |
2370 | && pthread_condattr_setclock (attr: &condattr, CLOCK_MONOTONIC) == 0) |
2371 | timeout_clock = CLOCK_MONOTONIC; |
2372 | #endif |
2373 | |
2374 | /* Create the attribute for the threads. They are all created |
2375 | detached. */ |
2376 | pthread_attr_init (attr: &attr); |
2377 | pthread_attr_setdetachstate (attr: &attr, PTHREAD_CREATE_DETACHED); |
2378 | /* Use 1MB stacks, twice as much for 64-bit architectures. */ |
2379 | pthread_attr_setstacksize (attr: &attr, NSCD_THREAD_STACKSIZE); |
2380 | |
2381 | /* We allow less than LASTDB threads only for debugging. */ |
2382 | if (debug_level == 0) |
2383 | nthreads = MAX (nthreads, lastdb); |
2384 | |
2385 | /* Create the threads which prune the databases. */ |
2386 | // XXX Ideally this work would be done by some of the worker threads. |
2387 | // XXX But this is problematic since we would need to be able to wake |
2388 | // XXX them up explicitly as well as part of the group handling the |
2389 | // XXX ready-list. This requires an operation where we can wait on |
2390 | // XXX two conditional variables at the same time. This operation |
2391 | // XXX does not exist (yet). |
2392 | for (long int i = 0; i < lastdb; ++i) |
2393 | { |
2394 | /* Initialize the conditional variable. */ |
2395 | if (pthread_cond_init (cond: &dbs[i].prune_cond, cond_attr: &condattr) != 0) |
2396 | { |
2397 | dbg_log (_("could not initialize conditional variable" )); |
2398 | do_exit (child_ret: 1, errnum: 0, NULL); |
2399 | } |
2400 | |
2401 | pthread_t th; |
2402 | if (dbs[i].enabled |
2403 | && pthread_create (newthread: &th, attr: &attr, start_routine: nscd_run_prune, arg: (void *) i) != 0) |
2404 | { |
2405 | dbg_log (_("could not start clean-up thread; terminating" )); |
2406 | do_exit (child_ret: 1, errnum: 0, NULL); |
2407 | } |
2408 | } |
2409 | |
2410 | pthread_condattr_destroy (attr: &condattr); |
2411 | |
2412 | for (long int i = 0; i < nthreads; ++i) |
2413 | { |
2414 | pthread_t th; |
2415 | if (pthread_create (newthread: &th, attr: &attr, start_routine: nscd_run_worker, NULL) != 0) |
2416 | { |
2417 | if (i == 0) |
2418 | { |
2419 | dbg_log (_("could not start any worker thread; terminating" )); |
2420 | do_exit (child_ret: 1, errnum: 0, NULL); |
2421 | } |
2422 | |
2423 | break; |
2424 | } |
2425 | } |
2426 | |
2427 | /* Now it is safe to let the parent know that we're doing fine and it can |
2428 | exit. */ |
2429 | notify_parent (child_ret: 0); |
2430 | |
2431 | /* Determine how much room for descriptors we should initially |
2432 | allocate. This might need to change later if we cap the number |
2433 | with MAXCONN. */ |
2434 | const long int nfds = sysconf (_SC_OPEN_MAX); |
2435 | #define MINCONN 32 |
2436 | #define MAXCONN 16384 |
2437 | if (nfds == -1 || nfds > MAXCONN) |
2438 | nconns = MAXCONN; |
2439 | else if (nfds < MINCONN) |
2440 | nconns = MINCONN; |
2441 | else |
2442 | nconns = nfds; |
2443 | |
2444 | /* We need memory to pass descriptors on to the worker threads. */ |
2445 | fdlist = (struct fdlist *) xcalloc (n: nconns, s: sizeof (fdlist[0])); |
2446 | /* Array to keep track when connection was accepted. */ |
2447 | starttime = (time_t *) xcalloc (n: nconns, s: sizeof (starttime[0])); |
2448 | |
2449 | /* In the main thread we execute the loop which handles incoming |
2450 | connections. */ |
2451 | #ifdef HAVE_EPOLL |
2452 | int efd = epoll_create (size: 100); |
2453 | if (efd != -1) |
2454 | { |
2455 | main_loop_epoll (efd); |
2456 | close (fd: efd); |
2457 | } |
2458 | #endif |
2459 | |
2460 | main_loop_poll (); |
2461 | } |
2462 | |
2463 | |
2464 | /* Look up the uid, gid, and supplementary groups to run nscd as. When |
2465 | this function is called, we are not listening on the nscd socket yet so |
2466 | we can just use the ordinary lookup functions without causing a lockup */ |
2467 | static void |
2468 | begin_drop_privileges (void) |
2469 | { |
2470 | struct passwd *pwd = getpwnam (name: server_user); |
2471 | |
2472 | if (pwd == NULL) |
2473 | { |
2474 | dbg_log (_("Failed to run nscd as user '%s'" ), server_user); |
2475 | do_exit (EXIT_FAILURE, errnum: 0, |
2476 | _("Failed to run nscd as user '%s'" ), server_user); |
2477 | } |
2478 | |
2479 | server_uid = pwd->pw_uid; |
2480 | server_gid = pwd->pw_gid; |
2481 | |
2482 | /* Save the old UID/GID if we have to change back. */ |
2483 | if (paranoia) |
2484 | { |
2485 | old_uid = getuid (); |
2486 | old_gid = getgid (); |
2487 | } |
2488 | |
2489 | if (getgrouplist (user: server_user, group: server_gid, NULL, ngroups: &server_ngroups) == 0) |
2490 | { |
2491 | /* This really must never happen. */ |
2492 | dbg_log (_("Failed to run nscd as user '%s'" ), server_user); |
2493 | do_exit (EXIT_FAILURE, errno, |
2494 | _("initial getgrouplist failed" )); |
2495 | } |
2496 | |
2497 | server_groups = (gid_t *) xmalloc (n: server_ngroups * sizeof (gid_t)); |
2498 | |
2499 | if (getgrouplist (user: server_user, group: server_gid, groups: server_groups, ngroups: &server_ngroups) |
2500 | == -1) |
2501 | { |
2502 | dbg_log (_("Failed to run nscd as user '%s'" ), server_user); |
2503 | do_exit (EXIT_FAILURE, errno, _("getgrouplist failed" )); |
2504 | } |
2505 | } |
2506 | |
2507 | |
2508 | /* Call setgroups(), setgid(), and setuid() to drop root privileges and |
2509 | run nscd as the user specified in the configuration file. */ |
2510 | static void |
2511 | finish_drop_privileges (void) |
2512 | { |
2513 | #if defined HAVE_LIBAUDIT && defined HAVE_LIBCAP |
2514 | /* We need to preserve the capabilities to connect to the audit daemon. */ |
2515 | cap_t new_caps = preserve_capabilities (); |
2516 | #endif |
2517 | |
2518 | if (setgroups (n: server_ngroups, groups: server_groups) == -1) |
2519 | { |
2520 | dbg_log (_("Failed to run nscd as user '%s'" ), server_user); |
2521 | do_exit (EXIT_FAILURE, errno, _("setgroups failed" )); |
2522 | } |
2523 | |
2524 | int res; |
2525 | if (paranoia) |
2526 | res = setresgid (rgid: server_gid, egid: server_gid, sgid: old_gid); |
2527 | else |
2528 | res = setgid (server_gid); |
2529 | if (res == -1) |
2530 | { |
2531 | dbg_log (_("Failed to run nscd as user '%s'" ), server_user); |
2532 | do_exit (child_ret: 4, errno, format: "setgid" ); |
2533 | } |
2534 | |
2535 | if (paranoia) |
2536 | res = setresuid (ruid: server_uid, euid: server_uid, suid: old_uid); |
2537 | else |
2538 | res = setuid (server_uid); |
2539 | if (res == -1) |
2540 | { |
2541 | dbg_log (_("Failed to run nscd as user '%s'" ), server_user); |
2542 | do_exit (child_ret: 4, errno, format: "setuid" ); |
2543 | } |
2544 | |
2545 | #if defined HAVE_LIBAUDIT && defined HAVE_LIBCAP |
2546 | /* Remove the temporary capabilities. */ |
2547 | install_real_capabilities (new_caps); |
2548 | #endif |
2549 | } |
2550 | |