1 | /* Inner loops of cache daemon. |
2 | Copyright (C) 1998-2017 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998. |
5 | |
6 | This program is free software; you can redistribute it and/or modify |
7 | it under the terms of the GNU General Public License as published |
8 | by the Free Software Foundation; version 2 of the License, or |
9 | (at your option) any later version. |
10 | |
11 | This program is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
14 | GNU General Public License for more details. |
15 | |
16 | You should have received a copy of the GNU General Public License |
17 | along with this program; if not, see <http://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <alloca.h> |
20 | #include <assert.h> |
21 | #include <atomic.h> |
22 | #include <error.h> |
23 | #include <errno.h> |
24 | #include <fcntl.h> |
25 | #include <grp.h> |
26 | #include <ifaddrs.h> |
27 | #include <libintl.h> |
28 | #include <pthread.h> |
29 | #include <pwd.h> |
30 | #include <resolv.h> |
31 | #include <stdio.h> |
32 | #include <stdlib.h> |
33 | #include <unistd.h> |
34 | #include <stdint.h> |
35 | #include <arpa/inet.h> |
36 | #ifdef HAVE_NETLINK |
37 | # include <linux/netlink.h> |
38 | # include <linux/rtnetlink.h> |
39 | #endif |
40 | #ifdef HAVE_EPOLL |
41 | # include <sys/epoll.h> |
42 | #endif |
43 | #ifdef HAVE_INOTIFY |
44 | # include <sys/inotify.h> |
45 | #endif |
46 | #include <sys/mman.h> |
47 | #include <sys/param.h> |
48 | #include <sys/poll.h> |
49 | #ifdef HAVE_SENDFILE |
50 | # include <sys/sendfile.h> |
51 | #endif |
52 | #include <sys/socket.h> |
53 | #include <sys/stat.h> |
54 | #include <sys/un.h> |
55 | |
56 | #include "nscd.h" |
57 | #include "dbg_log.h" |
58 | #include "selinux.h" |
59 | #include <resolv/resolv.h> |
60 | |
61 | #include <kernel-features.h> |
62 | #include <libc-internal.h> |
63 | |
64 | |
65 | /* Support to run nscd as an unprivileged user */ |
66 | const char *server_user; |
67 | static uid_t server_uid; |
68 | static gid_t server_gid; |
69 | const char *stat_user; |
70 | uid_t stat_uid; |
71 | static gid_t *server_groups; |
72 | #ifndef NGROUPS |
73 | # define NGROUPS 32 |
74 | #endif |
75 | static int server_ngroups; |
76 | |
77 | static pthread_attr_t attr; |
78 | |
79 | static void begin_drop_privileges (void); |
80 | static void finish_drop_privileges (void); |
81 | |
82 | /* Map request type to a string. */ |
83 | const char *const serv2str[LASTREQ] = |
84 | { |
85 | [GETPWBYNAME] = "GETPWBYNAME" , |
86 | [GETPWBYUID] = "GETPWBYUID" , |
87 | [GETGRBYNAME] = "GETGRBYNAME" , |
88 | [GETGRBYGID] = "GETGRBYGID" , |
89 | [GETHOSTBYNAME] = "GETHOSTBYNAME" , |
90 | [GETHOSTBYNAMEv6] = "GETHOSTBYNAMEv6" , |
91 | [GETHOSTBYADDR] = "GETHOSTBYADDR" , |
92 | [GETHOSTBYADDRv6] = "GETHOSTBYADDRv6" , |
93 | [SHUTDOWN] = "SHUTDOWN" , |
94 | [GETSTAT] = "GETSTAT" , |
95 | [INVALIDATE] = "INVALIDATE" , |
96 | [GETFDPW] = "GETFDPW" , |
97 | [GETFDGR] = "GETFDGR" , |
98 | [GETFDHST] = "GETFDHST" , |
99 | [GETAI] = "GETAI" , |
100 | [INITGROUPS] = "INITGROUPS" , |
101 | [GETSERVBYNAME] = "GETSERVBYNAME" , |
102 | [GETSERVBYPORT] = "GETSERVBYPORT" , |
103 | [GETFDSERV] = "GETFDSERV" , |
104 | [GETNETGRENT] = "GETNETGRENT" , |
105 | [INNETGR] = "INNETGR" , |
106 | [GETFDNETGR] = "GETFDNETGR" |
107 | }; |
108 | |
109 | /* The control data structures for the services. */ |
110 | struct database_dyn dbs[lastdb] = |
111 | { |
112 | [pwddb] = { |
113 | .lock = PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP, |
114 | .prune_lock = PTHREAD_MUTEX_INITIALIZER, |
115 | .prune_run_lock = PTHREAD_MUTEX_INITIALIZER, |
116 | .enabled = 0, |
117 | .check_file = 1, |
118 | .persistent = 0, |
119 | .propagate = 1, |
120 | .shared = 0, |
121 | .max_db_size = DEFAULT_MAX_DB_SIZE, |
122 | .suggested_module = DEFAULT_SUGGESTED_MODULE, |
123 | .db_filename = _PATH_NSCD_PASSWD_DB, |
124 | .disabled_iov = &pwd_iov_disabled, |
125 | .postimeout = 3600, |
126 | .negtimeout = 20, |
127 | .wr_fd = -1, |
128 | .ro_fd = -1, |
129 | .mmap_used = false |
130 | }, |
131 | [grpdb] = { |
132 | .lock = PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP, |
133 | .prune_lock = PTHREAD_MUTEX_INITIALIZER, |
134 | .prune_run_lock = PTHREAD_MUTEX_INITIALIZER, |
135 | .enabled = 0, |
136 | .check_file = 1, |
137 | .persistent = 0, |
138 | .propagate = 1, |
139 | .shared = 0, |
140 | .max_db_size = DEFAULT_MAX_DB_SIZE, |
141 | .suggested_module = DEFAULT_SUGGESTED_MODULE, |
142 | .db_filename = _PATH_NSCD_GROUP_DB, |
143 | .disabled_iov = &grp_iov_disabled, |
144 | .postimeout = 3600, |
145 | .negtimeout = 60, |
146 | .wr_fd = -1, |
147 | .ro_fd = -1, |
148 | .mmap_used = false |
149 | }, |
150 | [hstdb] = { |
151 | .lock = PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP, |
152 | .prune_lock = PTHREAD_MUTEX_INITIALIZER, |
153 | .prune_run_lock = PTHREAD_MUTEX_INITIALIZER, |
154 | .enabled = 0, |
155 | .check_file = 1, |
156 | .persistent = 0, |
157 | .propagate = 0, /* Not used. */ |
158 | .shared = 0, |
159 | .max_db_size = DEFAULT_MAX_DB_SIZE, |
160 | .suggested_module = DEFAULT_SUGGESTED_MODULE, |
161 | .db_filename = _PATH_NSCD_HOSTS_DB, |
162 | .disabled_iov = &hst_iov_disabled, |
163 | .postimeout = 3600, |
164 | .negtimeout = 20, |
165 | .wr_fd = -1, |
166 | .ro_fd = -1, |
167 | .mmap_used = false |
168 | }, |
169 | [servdb] = { |
170 | .lock = PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP, |
171 | .prune_lock = PTHREAD_MUTEX_INITIALIZER, |
172 | .prune_run_lock = PTHREAD_MUTEX_INITIALIZER, |
173 | .enabled = 0, |
174 | .check_file = 1, |
175 | .persistent = 0, |
176 | .propagate = 0, /* Not used. */ |
177 | .shared = 0, |
178 | .max_db_size = DEFAULT_MAX_DB_SIZE, |
179 | .suggested_module = DEFAULT_SUGGESTED_MODULE, |
180 | .db_filename = _PATH_NSCD_SERVICES_DB, |
181 | .disabled_iov = &serv_iov_disabled, |
182 | .postimeout = 28800, |
183 | .negtimeout = 20, |
184 | .wr_fd = -1, |
185 | .ro_fd = -1, |
186 | .mmap_used = false |
187 | }, |
188 | [netgrdb] = { |
189 | .lock = PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP, |
190 | .prune_lock = PTHREAD_MUTEX_INITIALIZER, |
191 | .prune_run_lock = PTHREAD_MUTEX_INITIALIZER, |
192 | .enabled = 0, |
193 | .check_file = 1, |
194 | .persistent = 0, |
195 | .propagate = 0, /* Not used. */ |
196 | .shared = 0, |
197 | .max_db_size = DEFAULT_MAX_DB_SIZE, |
198 | .suggested_module = DEFAULT_SUGGESTED_MODULE, |
199 | .db_filename = _PATH_NSCD_NETGROUP_DB, |
200 | .disabled_iov = &netgroup_iov_disabled, |
201 | .postimeout = 28800, |
202 | .negtimeout = 20, |
203 | .wr_fd = -1, |
204 | .ro_fd = -1, |
205 | .mmap_used = false |
206 | } |
207 | }; |
208 | |
209 | |
210 | /* Mapping of request type to database. */ |
211 | static struct |
212 | { |
213 | bool data_request; |
214 | struct database_dyn *db; |
215 | } const reqinfo[LASTREQ] = |
216 | { |
217 | [GETPWBYNAME] = { true, &dbs[pwddb] }, |
218 | [GETPWBYUID] = { true, &dbs[pwddb] }, |
219 | [GETGRBYNAME] = { true, &dbs[grpdb] }, |
220 | [GETGRBYGID] = { true, &dbs[grpdb] }, |
221 | [GETHOSTBYNAME] = { true, &dbs[hstdb] }, |
222 | [GETHOSTBYNAMEv6] = { true, &dbs[hstdb] }, |
223 | [GETHOSTBYADDR] = { true, &dbs[hstdb] }, |
224 | [GETHOSTBYADDRv6] = { true, &dbs[hstdb] }, |
225 | [SHUTDOWN] = { false, NULL }, |
226 | [GETSTAT] = { false, NULL }, |
227 | [SHUTDOWN] = { false, NULL }, |
228 | [GETFDPW] = { false, &dbs[pwddb] }, |
229 | [GETFDGR] = { false, &dbs[grpdb] }, |
230 | [GETFDHST] = { false, &dbs[hstdb] }, |
231 | [GETAI] = { true, &dbs[hstdb] }, |
232 | [INITGROUPS] = { true, &dbs[grpdb] }, |
233 | [GETSERVBYNAME] = { true, &dbs[servdb] }, |
234 | [GETSERVBYPORT] = { true, &dbs[servdb] }, |
235 | [GETFDSERV] = { false, &dbs[servdb] }, |
236 | [GETNETGRENT] = { true, &dbs[netgrdb] }, |
237 | [INNETGR] = { true, &dbs[netgrdb] }, |
238 | [GETFDNETGR] = { false, &dbs[netgrdb] } |
239 | }; |
240 | |
241 | |
242 | /* Initial number of threads to use. */ |
243 | int nthreads = -1; |
244 | /* Maximum number of threads to use. */ |
245 | int max_nthreads = 32; |
246 | |
247 | /* Socket for incoming connections. */ |
248 | static int sock; |
249 | |
250 | #ifdef HAVE_INOTIFY |
251 | /* Inotify descriptor. */ |
252 | int inotify_fd = -1; |
253 | #endif |
254 | |
255 | #ifdef HAVE_NETLINK |
256 | /* Descriptor for netlink status updates. */ |
257 | static int nl_status_fd = -1; |
258 | #endif |
259 | |
260 | #ifndef __ASSUME_ACCEPT4 |
261 | static int have_accept4; |
262 | #endif |
263 | |
264 | /* Number of times clients had to wait. */ |
265 | unsigned long int client_queued; |
266 | |
267 | |
268 | ssize_t |
269 | writeall (int fd, const void *buf, size_t len) |
270 | { |
271 | size_t n = len; |
272 | ssize_t ret; |
273 | do |
274 | { |
275 | ret = TEMP_FAILURE_RETRY (send (fd, buf, n, MSG_NOSIGNAL)); |
276 | if (ret <= 0) |
277 | break; |
278 | buf = (const char *) buf + ret; |
279 | n -= ret; |
280 | } |
281 | while (n > 0); |
282 | return ret < 0 ? ret : len - n; |
283 | } |
284 | |
285 | |
286 | #ifdef HAVE_SENDFILE |
287 | ssize_t |
288 | sendfileall (int tofd, int fromfd, off_t off, size_t len) |
289 | { |
290 | ssize_t n = len; |
291 | ssize_t ret; |
292 | |
293 | do |
294 | { |
295 | ret = TEMP_FAILURE_RETRY (sendfile (tofd, fromfd, &off, n)); |
296 | if (ret <= 0) |
297 | break; |
298 | n -= ret; |
299 | } |
300 | while (n > 0); |
301 | return ret < 0 ? ret : len - n; |
302 | } |
303 | #endif |
304 | |
305 | |
306 | enum usekey |
307 | { |
308 | use_not = 0, |
309 | /* The following three are not really used, they are symbolic constants. */ |
310 | use_first = 16, |
311 | use_begin = 32, |
312 | use_end = 64, |
313 | |
314 | use_he = 1, |
315 | use_he_begin = use_he | use_begin, |
316 | use_he_end = use_he | use_end, |
317 | use_data = 3, |
318 | use_data_begin = use_data | use_begin, |
319 | use_data_end = use_data | use_end, |
320 | use_data_first = use_data_begin | use_first |
321 | }; |
322 | |
323 | |
324 | static int |
325 | check_use (const char *data, nscd_ssize_t first_free, uint8_t *usemap, |
326 | enum usekey use, ref_t start, size_t len) |
327 | { |
328 | assert (len >= 2); |
329 | |
330 | if (start > first_free || start + len > first_free |
331 | || (start & BLOCK_ALIGN_M1)) |
332 | return 0; |
333 | |
334 | if (usemap[start] == use_not) |
335 | { |
336 | /* Add the start marker. */ |
337 | usemap[start] = use | use_begin; |
338 | use &= ~use_first; |
339 | |
340 | while (--len > 0) |
341 | if (usemap[++start] != use_not) |
342 | return 0; |
343 | else |
344 | usemap[start] = use; |
345 | |
346 | /* Add the end marker. */ |
347 | usemap[start] = use | use_end; |
348 | } |
349 | else if ((usemap[start] & ~use_first) == ((use | use_begin) & ~use_first)) |
350 | { |
351 | /* Hash entries can't be shared. */ |
352 | if (use == use_he) |
353 | return 0; |
354 | |
355 | usemap[start] |= (use & use_first); |
356 | use &= ~use_first; |
357 | |
358 | while (--len > 1) |
359 | if (usemap[++start] != use) |
360 | return 0; |
361 | |
362 | if (usemap[++start] != (use | use_end)) |
363 | return 0; |
364 | } |
365 | else |
366 | /* Points to a wrong object or somewhere in the middle. */ |
367 | return 0; |
368 | |
369 | return 1; |
370 | } |
371 | |
372 | |
373 | /* Verify data in persistent database. */ |
374 | static int |
375 | verify_persistent_db (void *mem, struct database_pers_head *readhead, int dbnr) |
376 | { |
377 | assert (dbnr == pwddb || dbnr == grpdb || dbnr == hstdb || dbnr == servdb |
378 | || dbnr == netgrdb); |
379 | |
380 | time_t now = time (NULL); |
381 | |
382 | struct database_pers_head *head = mem; |
383 | struct database_pers_head head_copy = *head; |
384 | |
385 | /* Check that the header that was read matches the head in the database. */ |
386 | if (memcmp (head, readhead, sizeof (*head)) != 0) |
387 | return 0; |
388 | |
389 | /* First some easy tests: make sure the database header is sane. */ |
390 | if (head->version != DB_VERSION |
391 | || head->header_size != sizeof (*head) |
392 | /* We allow a timestamp to be one hour ahead of the current time. |
393 | This should cover daylight saving time changes. */ |
394 | || head->timestamp > now + 60 * 60 + 60 |
395 | || (head->gc_cycle & 1) |
396 | || head->module == 0 |
397 | || (size_t) head->module > INT32_MAX / sizeof (ref_t) |
398 | || (size_t) head->data_size > INT32_MAX - head->module * sizeof (ref_t) |
399 | || head->first_free < 0 |
400 | || head->first_free > head->data_size |
401 | || (head->first_free & BLOCK_ALIGN_M1) != 0 |
402 | || head->maxnentries < 0 |
403 | || head->maxnsearched < 0) |
404 | return 0; |
405 | |
406 | uint8_t *usemap = calloc (head->first_free, 1); |
407 | if (usemap == NULL) |
408 | return 0; |
409 | |
410 | const char *data = (char *) &head->array[roundup (head->module, |
411 | ALIGN / sizeof (ref_t))]; |
412 | |
413 | nscd_ssize_t he_cnt = 0; |
414 | for (nscd_ssize_t cnt = 0; cnt < head->module; ++cnt) |
415 | { |
416 | ref_t trail = head->array[cnt]; |
417 | ref_t work = trail; |
418 | int tick = 0; |
419 | |
420 | while (work != ENDREF) |
421 | { |
422 | if (! check_use (data, head->first_free, usemap, use_he, work, |
423 | sizeof (struct hashentry))) |
424 | goto fail; |
425 | |
426 | /* Now we know we can dereference the record. */ |
427 | struct hashentry *here = (struct hashentry *) (data + work); |
428 | |
429 | ++he_cnt; |
430 | |
431 | /* Make sure the record is for this type of service. */ |
432 | if (here->type >= LASTREQ |
433 | || reqinfo[here->type].db != &dbs[dbnr]) |
434 | goto fail; |
435 | |
436 | /* Validate boolean field value. */ |
437 | if (here->first != false && here->first != true) |
438 | goto fail; |
439 | |
440 | if (here->len < 0) |
441 | goto fail; |
442 | |
443 | /* Now the data. */ |
444 | if (here->packet < 0 |
445 | || here->packet > head->first_free |
446 | || here->packet + sizeof (struct datahead) > head->first_free) |
447 | goto fail; |
448 | |
449 | struct datahead *dh = (struct datahead *) (data + here->packet); |
450 | |
451 | if (! check_use (data, head->first_free, usemap, |
452 | use_data | (here->first ? use_first : 0), |
453 | here->packet, dh->allocsize)) |
454 | goto fail; |
455 | |
456 | if (dh->allocsize < sizeof (struct datahead) |
457 | || dh->recsize > dh->allocsize |
458 | || (dh->notfound != false && dh->notfound != true) |
459 | || (dh->usable != false && dh->usable != true)) |
460 | goto fail; |
461 | |
462 | if (here->key < here->packet + sizeof (struct datahead) |
463 | || here->key > here->packet + dh->allocsize |
464 | || here->key + here->len > here->packet + dh->allocsize) |
465 | goto fail; |
466 | |
467 | work = here->next; |
468 | |
469 | if (work == trail) |
470 | /* A circular list, this must not happen. */ |
471 | goto fail; |
472 | if (tick) |
473 | trail = ((struct hashentry *) (data + trail))->next; |
474 | tick = 1 - tick; |
475 | } |
476 | } |
477 | |
478 | if (he_cnt != head->nentries) |
479 | goto fail; |
480 | |
481 | /* See if all data and keys had at least one reference from |
482 | he->first == true hashentry. */ |
483 | for (ref_t idx = 0; idx < head->first_free; ++idx) |
484 | { |
485 | if (usemap[idx] == use_data_begin) |
486 | goto fail; |
487 | } |
488 | |
489 | /* Finally, make sure the database hasn't changed since the first test. */ |
490 | if (memcmp (mem, &head_copy, sizeof (*head)) != 0) |
491 | goto fail; |
492 | |
493 | free (usemap); |
494 | return 1; |
495 | |
496 | fail: |
497 | free (usemap); |
498 | return 0; |
499 | } |
500 | |
501 | |
502 | #ifdef O_CLOEXEC |
503 | # define O_CLOEXEC |
504 | #else |
505 | # define EXTRA_O_FLAGS 0 |
506 | #endif |
507 | |
508 | |
509 | /* Initialize database information structures. */ |
510 | void |
511 | nscd_init (void) |
512 | { |
513 | /* Look up unprivileged uid/gid/groups before we start listening on the |
514 | socket */ |
515 | if (server_user != NULL) |
516 | begin_drop_privileges (); |
517 | |
518 | if (nthreads == -1) |
519 | /* No configuration for this value, assume a default. */ |
520 | nthreads = 4; |
521 | |
522 | for (size_t cnt = 0; cnt < lastdb; ++cnt) |
523 | if (dbs[cnt].enabled) |
524 | { |
525 | pthread_rwlock_init (&dbs[cnt].lock, NULL); |
526 | pthread_mutex_init (&dbs[cnt].memlock, NULL); |
527 | |
528 | if (dbs[cnt].persistent) |
529 | { |
530 | /* Try to open the appropriate file on disk. */ |
531 | int fd = open (dbs[cnt].db_filename, O_RDWR | EXTRA_O_FLAGS); |
532 | if (fd != -1) |
533 | { |
534 | char *msg = NULL; |
535 | struct stat64 st; |
536 | void *mem; |
537 | size_t total; |
538 | struct database_pers_head head; |
539 | ssize_t n = TEMP_FAILURE_RETRY (read (fd, &head, |
540 | sizeof (head))); |
541 | if (n != sizeof (head) || fstat64 (fd, &st) != 0) |
542 | { |
543 | fail_db_errno: |
544 | /* The code is single-threaded at this point so |
545 | using strerror is just fine. */ |
546 | msg = strerror (errno); |
547 | fail_db: |
548 | dbg_log (_("invalid persistent database file \"%s\": %s" ), |
549 | dbs[cnt].db_filename, msg); |
550 | unlink (dbs[cnt].db_filename); |
551 | } |
552 | else if (head.module == 0 && head.data_size == 0) |
553 | { |
554 | /* The file has been created, but the head has not |
555 | been initialized yet. */ |
556 | msg = _("uninitialized header" ); |
557 | goto fail_db; |
558 | } |
559 | else if (head.header_size != (int) sizeof (head)) |
560 | { |
561 | msg = _("header size does not match" ); |
562 | goto fail_db; |
563 | } |
564 | else if ((total = (sizeof (head) |
565 | + roundup (head.module * sizeof (ref_t), |
566 | ALIGN) |
567 | + head.data_size)) |
568 | > st.st_size |
569 | || total < sizeof (head)) |
570 | { |
571 | msg = _("file size does not match" ); |
572 | goto fail_db; |
573 | } |
574 | /* Note we map with the maximum size allowed for the |
575 | database. This is likely much larger than the |
576 | actual file size. This is OK on most OSes since |
577 | extensions of the underlying file will |
578 | automatically translate more pages available for |
579 | memory access. */ |
580 | else if ((mem = mmap (NULL, dbs[cnt].max_db_size, |
581 | PROT_READ | PROT_WRITE, |
582 | MAP_SHARED, fd, 0)) |
583 | == MAP_FAILED) |
584 | goto fail_db_errno; |
585 | else if (!verify_persistent_db (mem, &head, cnt)) |
586 | { |
587 | munmap (mem, total); |
588 | msg = _("verification failed" ); |
589 | goto fail_db; |
590 | } |
591 | else |
592 | { |
593 | /* Success. We have the database. */ |
594 | dbs[cnt].head = mem; |
595 | dbs[cnt].memsize = total; |
596 | dbs[cnt].data = (char *) |
597 | &dbs[cnt].head->array[roundup (dbs[cnt].head->module, |
598 | ALIGN / sizeof (ref_t))]; |
599 | dbs[cnt].mmap_used = true; |
600 | |
601 | if (dbs[cnt].suggested_module > head.module) |
602 | dbg_log (_("suggested size of table for database %s larger than the persistent database's table" ), |
603 | dbnames[cnt]); |
604 | |
605 | dbs[cnt].wr_fd = fd; |
606 | fd = -1; |
607 | /* We also need a read-only descriptor. */ |
608 | if (dbs[cnt].shared) |
609 | { |
610 | dbs[cnt].ro_fd = open (dbs[cnt].db_filename, |
611 | O_RDONLY | EXTRA_O_FLAGS); |
612 | if (dbs[cnt].ro_fd == -1) |
613 | dbg_log (_("\ |
614 | cannot create read-only descriptor for \"%s\"; no mmap" ), |
615 | dbs[cnt].db_filename); |
616 | } |
617 | |
618 | // XXX Shall we test whether the descriptors actually |
619 | // XXX point to the same file? |
620 | } |
621 | |
622 | /* Close the file descriptors in case something went |
623 | wrong in which case the variable have not been |
624 | assigned -1. */ |
625 | if (fd != -1) |
626 | close (fd); |
627 | } |
628 | else if (errno == EACCES) |
629 | do_exit (EXIT_FAILURE, 0, _("cannot access '%s'" ), |
630 | dbs[cnt].db_filename); |
631 | } |
632 | |
633 | if (dbs[cnt].head == NULL) |
634 | { |
635 | /* No database loaded. Allocate the data structure, |
636 | possibly on disk. */ |
637 | struct database_pers_head head; |
638 | size_t total = (sizeof (head) |
639 | + roundup (dbs[cnt].suggested_module |
640 | * sizeof (ref_t), ALIGN) |
641 | + (dbs[cnt].suggested_module |
642 | * DEFAULT_DATASIZE_PER_BUCKET)); |
643 | |
644 | /* Try to create the database. If we do not need a |
645 | persistent database create a temporary file. */ |
646 | int fd; |
647 | int ro_fd = -1; |
648 | if (dbs[cnt].persistent) |
649 | { |
650 | fd = open (dbs[cnt].db_filename, |
651 | O_RDWR | O_CREAT | O_EXCL | O_TRUNC | EXTRA_O_FLAGS, |
652 | S_IRUSR | S_IWUSR); |
653 | if (fd != -1 && dbs[cnt].shared) |
654 | ro_fd = open (dbs[cnt].db_filename, |
655 | O_RDONLY | EXTRA_O_FLAGS); |
656 | } |
657 | else |
658 | { |
659 | char fname[] = _PATH_NSCD_XYZ_DB_TMP; |
660 | fd = mkostemp (fname, EXTRA_O_FLAGS); |
661 | |
662 | /* We do not need the file name anymore after we |
663 | opened another file descriptor in read-only mode. */ |
664 | if (fd != -1) |
665 | { |
666 | if (dbs[cnt].shared) |
667 | ro_fd = open (fname, O_RDONLY | EXTRA_O_FLAGS); |
668 | |
669 | unlink (fname); |
670 | } |
671 | } |
672 | |
673 | if (fd == -1) |
674 | { |
675 | if (errno == EEXIST) |
676 | { |
677 | dbg_log (_("database for %s corrupted or simultaneously used; remove %s manually if necessary and restart" ), |
678 | dbnames[cnt], dbs[cnt].db_filename); |
679 | do_exit (1, 0, NULL); |
680 | } |
681 | |
682 | if (dbs[cnt].persistent) |
683 | dbg_log (_("cannot create %s; no persistent database used" ), |
684 | dbs[cnt].db_filename); |
685 | else |
686 | dbg_log (_("cannot create %s; no sharing possible" ), |
687 | dbs[cnt].db_filename); |
688 | |
689 | dbs[cnt].persistent = 0; |
690 | // XXX remember: no mmap |
691 | } |
692 | else |
693 | { |
694 | /* Tell the user if we could not create the read-only |
695 | descriptor. */ |
696 | if (ro_fd == -1 && dbs[cnt].shared) |
697 | dbg_log (_("\ |
698 | cannot create read-only descriptor for \"%s\"; no mmap" ), |
699 | dbs[cnt].db_filename); |
700 | |
701 | /* Before we create the header, initialize the hash |
702 | table. That way if we get interrupted while writing |
703 | the header we can recognize a partially initialized |
704 | database. */ |
705 | size_t ps = sysconf (_SC_PAGESIZE); |
706 | char tmpbuf[ps]; |
707 | assert (~ENDREF == 0); |
708 | memset (tmpbuf, '\xff', ps); |
709 | |
710 | size_t remaining = dbs[cnt].suggested_module * sizeof (ref_t); |
711 | off_t offset = sizeof (head); |
712 | |
713 | size_t towrite; |
714 | if (offset % ps != 0) |
715 | { |
716 | towrite = MIN (remaining, ps - (offset % ps)); |
717 | if (pwrite (fd, tmpbuf, towrite, offset) != towrite) |
718 | goto write_fail; |
719 | offset += towrite; |
720 | remaining -= towrite; |
721 | } |
722 | |
723 | while (remaining > ps) |
724 | { |
725 | if (pwrite (fd, tmpbuf, ps, offset) == -1) |
726 | goto write_fail; |
727 | offset += ps; |
728 | remaining -= ps; |
729 | } |
730 | |
731 | if (remaining > 0 |
732 | && pwrite (fd, tmpbuf, remaining, offset) != remaining) |
733 | goto write_fail; |
734 | |
735 | /* Create the header of the file. */ |
736 | struct database_pers_head head = |
737 | { |
738 | .version = DB_VERSION, |
739 | .header_size = sizeof (head), |
740 | .module = dbs[cnt].suggested_module, |
741 | .data_size = (dbs[cnt].suggested_module |
742 | * DEFAULT_DATASIZE_PER_BUCKET), |
743 | .first_free = 0 |
744 | }; |
745 | void *mem; |
746 | |
747 | if ((TEMP_FAILURE_RETRY (write (fd, &head, sizeof (head))) |
748 | != sizeof (head)) |
749 | || (TEMP_FAILURE_RETRY_VAL (posix_fallocate (fd, 0, total)) |
750 | != 0) |
751 | || (mem = mmap (NULL, dbs[cnt].max_db_size, |
752 | PROT_READ | PROT_WRITE, |
753 | MAP_SHARED, fd, 0)) == MAP_FAILED) |
754 | { |
755 | write_fail: |
756 | unlink (dbs[cnt].db_filename); |
757 | dbg_log (_("cannot write to database file %s: %s" ), |
758 | dbs[cnt].db_filename, strerror (errno)); |
759 | dbs[cnt].persistent = 0; |
760 | } |
761 | else |
762 | { |
763 | /* Success. */ |
764 | dbs[cnt].head = mem; |
765 | dbs[cnt].data = (char *) |
766 | &dbs[cnt].head->array[roundup (dbs[cnt].head->module, |
767 | ALIGN / sizeof (ref_t))]; |
768 | dbs[cnt].memsize = total; |
769 | dbs[cnt].mmap_used = true; |
770 | |
771 | /* Remember the descriptors. */ |
772 | dbs[cnt].wr_fd = fd; |
773 | dbs[cnt].ro_fd = ro_fd; |
774 | fd = -1; |
775 | ro_fd = -1; |
776 | } |
777 | |
778 | if (fd != -1) |
779 | close (fd); |
780 | if (ro_fd != -1) |
781 | close (ro_fd); |
782 | } |
783 | } |
784 | |
785 | #if !defined O_CLOEXEC || !defined __ASSUME_O_CLOEXEC |
786 | /* We do not check here whether the O_CLOEXEC provided to the |
787 | open call was successful or not. The two fcntl calls are |
788 | only performed once each per process start-up and therefore |
789 | is not noticeable at all. */ |
790 | if (paranoia |
791 | && ((dbs[cnt].wr_fd != -1 |
792 | && fcntl (dbs[cnt].wr_fd, F_SETFD, FD_CLOEXEC) == -1) |
793 | || (dbs[cnt].ro_fd != -1 |
794 | && fcntl (dbs[cnt].ro_fd, F_SETFD, FD_CLOEXEC) == -1))) |
795 | { |
796 | dbg_log (_("\ |
797 | cannot set socket to close on exec: %s; disabling paranoia mode" ), |
798 | strerror (errno)); |
799 | paranoia = 0; |
800 | } |
801 | #endif |
802 | |
803 | if (dbs[cnt].head == NULL) |
804 | { |
805 | /* We do not use the persistent database. Just |
806 | create an in-memory data structure. */ |
807 | assert (! dbs[cnt].persistent); |
808 | |
809 | dbs[cnt].head = xmalloc (sizeof (struct database_pers_head) |
810 | + (dbs[cnt].suggested_module |
811 | * sizeof (ref_t))); |
812 | memset (dbs[cnt].head, '\0', sizeof (struct database_pers_head)); |
813 | assert (~ENDREF == 0); |
814 | memset (dbs[cnt].head->array, '\xff', |
815 | dbs[cnt].suggested_module * sizeof (ref_t)); |
816 | dbs[cnt].head->module = dbs[cnt].suggested_module; |
817 | dbs[cnt].head->data_size = (DEFAULT_DATASIZE_PER_BUCKET |
818 | * dbs[cnt].head->module); |
819 | dbs[cnt].data = xmalloc (dbs[cnt].head->data_size); |
820 | dbs[cnt].head->first_free = 0; |
821 | |
822 | dbs[cnt].shared = 0; |
823 | assert (dbs[cnt].ro_fd == -1); |
824 | } |
825 | } |
826 | |
827 | /* Create the socket. */ |
828 | sock = socket (AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0); |
829 | if (sock < 0) |
830 | { |
831 | dbg_log (_("cannot open socket: %s" ), strerror (errno)); |
832 | do_exit (errno == EACCES ? 4 : 1, 0, NULL); |
833 | } |
834 | /* Bind a name to the socket. */ |
835 | struct sockaddr_un sock_addr; |
836 | sock_addr.sun_family = AF_UNIX; |
837 | strcpy (sock_addr.sun_path, _PATH_NSCDSOCKET); |
838 | if (bind (sock, (struct sockaddr *) &sock_addr, sizeof (sock_addr)) < 0) |
839 | { |
840 | dbg_log ("%s: %s" , _PATH_NSCDSOCKET, strerror (errno)); |
841 | do_exit (errno == EACCES ? 4 : 1, 0, NULL); |
842 | } |
843 | |
844 | /* Set permissions for the socket. */ |
845 | chmod (_PATH_NSCDSOCKET, DEFFILEMODE); |
846 | |
847 | /* Set the socket up to accept connections. */ |
848 | if (listen (sock, SOMAXCONN) < 0) |
849 | { |
850 | dbg_log (_("cannot enable socket to accept connections: %s" ), |
851 | strerror (errno)); |
852 | do_exit (1, 0, NULL); |
853 | } |
854 | |
855 | #ifdef HAVE_NETLINK |
856 | if (dbs[hstdb].enabled) |
857 | { |
858 | /* Try to open netlink socket to monitor network setting changes. */ |
859 | nl_status_fd = socket (AF_NETLINK, |
860 | SOCK_RAW | SOCK_CLOEXEC | SOCK_NONBLOCK, |
861 | NETLINK_ROUTE); |
862 | if (nl_status_fd != -1) |
863 | { |
864 | struct sockaddr_nl snl; |
865 | memset (&snl, '\0', sizeof (snl)); |
866 | snl.nl_family = AF_NETLINK; |
867 | /* XXX Is this the best set to use? */ |
868 | snl.nl_groups = (RTMGRP_IPV4_IFADDR | RTMGRP_TC | RTMGRP_IPV4_MROUTE |
869 | | RTMGRP_IPV4_ROUTE | RTMGRP_IPV4_RULE |
870 | | RTMGRP_IPV6_IFADDR | RTMGRP_IPV6_MROUTE |
871 | | RTMGRP_IPV6_ROUTE | RTMGRP_IPV6_IFINFO |
872 | | RTMGRP_IPV6_PREFIX); |
873 | |
874 | if (bind (nl_status_fd, (struct sockaddr *) &snl, sizeof (snl)) != 0) |
875 | { |
876 | close (nl_status_fd); |
877 | nl_status_fd = -1; |
878 | } |
879 | else |
880 | { |
881 | /* Start the timestamp process. */ |
882 | dbs[hstdb].head->extra_data[NSCD_HST_IDX_CONF_TIMESTAMP] |
883 | = __bump_nl_timestamp (); |
884 | } |
885 | } |
886 | } |
887 | #endif |
888 | |
889 | /* Change to unprivileged uid/gid/groups if specified in config file */ |
890 | if (server_user != NULL) |
891 | finish_drop_privileges (); |
892 | } |
893 | |
894 | #ifdef HAVE_INOTIFY |
895 | #define TRACED_FILE_MASK (IN_DELETE_SELF | IN_CLOSE_WRITE | IN_MOVE_SELF) |
896 | #define TRACED_DIR_MASK (IN_DELETE_SELF | IN_CREATE | IN_MOVED_TO | IN_MOVE_SELF) |
897 | void |
898 | install_watches (struct traced_file *finfo) |
899 | { |
900 | /* Use inotify support if we have it. */ |
901 | if (finfo->inotify_descr[TRACED_FILE] < 0) |
902 | finfo->inotify_descr[TRACED_FILE] = inotify_add_watch (inotify_fd, |
903 | finfo->fname, |
904 | TRACED_FILE_MASK); |
905 | if (finfo->inotify_descr[TRACED_FILE] < 0) |
906 | { |
907 | dbg_log (_("disabled inotify-based monitoring for file `%s': %s" ), |
908 | finfo->fname, strerror (errno)); |
909 | return; |
910 | } |
911 | dbg_log (_("monitoring file `%s` (%d)" ), |
912 | finfo->fname, finfo->inotify_descr[TRACED_FILE]); |
913 | /* Additionally listen for events in the file's parent directory. |
914 | We do this because the file to be watched might be |
915 | deleted and then added back again. When it is added back again |
916 | we must re-add the watch. We must also cover IN_MOVED_TO to |
917 | detect a file being moved into the directory. */ |
918 | if (finfo->inotify_descr[TRACED_DIR] < 0) |
919 | finfo->inotify_descr[TRACED_DIR] = inotify_add_watch (inotify_fd, |
920 | finfo->dname, |
921 | TRACED_DIR_MASK); |
922 | if (finfo->inotify_descr[TRACED_DIR] < 0) |
923 | { |
924 | dbg_log (_("disabled inotify-based monitoring for directory `%s': %s" ), |
925 | finfo->fname, strerror (errno)); |
926 | return; |
927 | } |
928 | dbg_log (_("monitoring directory `%s` (%d)" ), |
929 | finfo->dname, finfo->inotify_descr[TRACED_DIR]); |
930 | } |
931 | #endif |
932 | |
933 | /* Register the file in FINFO as a traced file for the database DBS[DBIX]. |
934 | |
935 | We support registering multiple files per database. Each call to |
936 | register_traced_file adds to the list of registered files. |
937 | |
938 | When we prune the database, either through timeout or a request to |
939 | invalidate, we will check to see if any of the registered files has changed. |
940 | When we accept new connections to handle a cache request we will also |
941 | check to see if any of the registered files has changed. |
942 | |
943 | If we have inotify support then we install an inotify fd to notify us of |
944 | file deletion or modification, both of which will require we invalidate |
945 | the cache for the database. Without inotify support we stat the file and |
946 | store st_mtime to determine if the file has been modified. */ |
947 | void |
948 | register_traced_file (size_t dbidx, struct traced_file *finfo) |
949 | { |
950 | /* If the database is disabled or file checking is disabled |
951 | then ignore the registration. */ |
952 | if (! dbs[dbidx].enabled || ! dbs[dbidx].check_file) |
953 | return; |
954 | |
955 | if (__glibc_unlikely (debug_level > 0)) |
956 | dbg_log (_("monitoring file %s for database %s" ), |
957 | finfo->fname, dbnames[dbidx]); |
958 | |
959 | #ifdef HAVE_INOTIFY |
960 | install_watches (finfo); |
961 | #endif |
962 | struct stat64 st; |
963 | if (stat64 (finfo->fname, &st) < 0) |
964 | { |
965 | /* We cannot stat() the file. Set mtime to zero and try again later. */ |
966 | dbg_log (_("stat failed for file `%s'; will try again later: %s" ), |
967 | finfo->fname, strerror (errno)); |
968 | finfo->mtime = 0; |
969 | } |
970 | else |
971 | finfo->mtime = st.st_mtime; |
972 | |
973 | /* Queue up the file name. */ |
974 | finfo->next = dbs[dbidx].traced_files; |
975 | dbs[dbidx].traced_files = finfo; |
976 | } |
977 | |
978 | |
979 | /* Close the connections. */ |
980 | void |
981 | close_sockets (void) |
982 | { |
983 | close (sock); |
984 | } |
985 | |
986 | |
987 | static void |
988 | invalidate_cache (char *key, int fd) |
989 | { |
990 | dbtype number; |
991 | int32_t resp; |
992 | |
993 | for (number = pwddb; number < lastdb; ++number) |
994 | if (strcmp (key, dbnames[number]) == 0) |
995 | { |
996 | struct traced_file *runp = dbs[number].traced_files; |
997 | while (runp != NULL) |
998 | { |
999 | /* Make sure we reload from file when checking mtime. */ |
1000 | runp->mtime = 0; |
1001 | #ifdef HAVE_INOTIFY |
1002 | /* During an invalidation we try to reload the traced |
1003 | file watches. This allows the user to re-sync if |
1004 | inotify events were lost. Similar to what we do during |
1005 | pruning. */ |
1006 | install_watches (runp); |
1007 | #endif |
1008 | if (runp->call_res_init) |
1009 | { |
1010 | res_init (); |
1011 | break; |
1012 | } |
1013 | runp = runp->next; |
1014 | } |
1015 | break; |
1016 | } |
1017 | |
1018 | if (number == lastdb) |
1019 | { |
1020 | resp = EINVAL; |
1021 | writeall (fd, &resp, sizeof (resp)); |
1022 | return; |
1023 | } |
1024 | |
1025 | if (dbs[number].enabled) |
1026 | { |
1027 | pthread_mutex_lock (&dbs[number].prune_run_lock); |
1028 | prune_cache (&dbs[number], LONG_MAX, fd); |
1029 | pthread_mutex_unlock (&dbs[number].prune_run_lock); |
1030 | } |
1031 | else |
1032 | { |
1033 | resp = 0; |
1034 | writeall (fd, &resp, sizeof (resp)); |
1035 | } |
1036 | } |
1037 | |
1038 | |
1039 | #ifdef SCM_RIGHTS |
1040 | static void |
1041 | send_ro_fd (struct database_dyn *db, char *key, int fd) |
1042 | { |
1043 | /* If we do not have an read-only file descriptor do nothing. */ |
1044 | if (db->ro_fd == -1) |
1045 | return; |
1046 | |
1047 | /* We need to send some data along with the descriptor. */ |
1048 | uint64_t mapsize = (db->head->data_size |
1049 | + roundup (db->head->module * sizeof (ref_t), ALIGN) |
1050 | + sizeof (struct database_pers_head)); |
1051 | struct iovec iov[2]; |
1052 | iov[0].iov_base = key; |
1053 | iov[0].iov_len = strlen (key) + 1; |
1054 | iov[1].iov_base = &mapsize; |
1055 | iov[1].iov_len = sizeof (mapsize); |
1056 | |
1057 | /* Prepare the control message to transfer the descriptor. */ |
1058 | union |
1059 | { |
1060 | struct cmsghdr hdr; |
1061 | char bytes[CMSG_SPACE (sizeof (int))]; |
1062 | } buf; |
1063 | struct msghdr msg = { .msg_iov = iov, .msg_iovlen = 2, |
1064 | .msg_control = buf.bytes, |
1065 | .msg_controllen = sizeof (buf) }; |
1066 | struct cmsghdr *cmsg = CMSG_FIRSTHDR (&msg); |
1067 | |
1068 | cmsg->cmsg_level = SOL_SOCKET; |
1069 | cmsg->cmsg_type = SCM_RIGHTS; |
1070 | cmsg->cmsg_len = CMSG_LEN (sizeof (int)); |
1071 | |
1072 | int *ip = (int *) CMSG_DATA (cmsg); |
1073 | *ip = db->ro_fd; |
1074 | |
1075 | msg.msg_controllen = cmsg->cmsg_len; |
1076 | |
1077 | /* Send the control message. We repeat when we are interrupted but |
1078 | everything else is ignored. */ |
1079 | #ifndef MSG_NOSIGNAL |
1080 | # define MSG_NOSIGNAL 0 |
1081 | #endif |
1082 | (void) TEMP_FAILURE_RETRY (sendmsg (fd, &msg, MSG_NOSIGNAL)); |
1083 | |
1084 | if (__glibc_unlikely (debug_level > 0)) |
1085 | dbg_log (_("provide access to FD %d, for %s" ), db->ro_fd, key); |
1086 | } |
1087 | #endif /* SCM_RIGHTS */ |
1088 | |
1089 | |
1090 | /* Handle new request. */ |
1091 | static void |
1092 | handle_request (int fd, request_header *req, void *key, uid_t uid, pid_t pid) |
1093 | { |
1094 | if (__builtin_expect (req->version, NSCD_VERSION) != NSCD_VERSION) |
1095 | { |
1096 | if (debug_level > 0) |
1097 | dbg_log (_("\ |
1098 | cannot handle old request version %d; current version is %d" ), |
1099 | req->version, NSCD_VERSION); |
1100 | return; |
1101 | } |
1102 | |
1103 | /* Perform the SELinux check before we go on to the standard checks. */ |
1104 | if (selinux_enabled && nscd_request_avc_has_perm (fd, req->type) != 0) |
1105 | { |
1106 | if (debug_level > 0) |
1107 | { |
1108 | #ifdef SO_PEERCRED |
1109 | # ifdef PATH_MAX |
1110 | char buf[PATH_MAX]; |
1111 | # else |
1112 | char buf[4096]; |
1113 | # endif |
1114 | |
1115 | snprintf (buf, sizeof (buf), "/proc/%ld/exe" , (long int) pid); |
1116 | ssize_t n = readlink (buf, buf, sizeof (buf) - 1); |
1117 | |
1118 | if (n <= 0) |
1119 | dbg_log (_("\ |
1120 | request from %ld not handled due to missing permission" ), (long int) pid); |
1121 | else |
1122 | { |
1123 | buf[n] = '\0'; |
1124 | dbg_log (_("\ |
1125 | request from '%s' [%ld] not handled due to missing permission" ), |
1126 | buf, (long int) pid); |
1127 | } |
1128 | #else |
1129 | dbg_log (_("request not handled due to missing permission" )); |
1130 | #endif |
1131 | } |
1132 | return; |
1133 | } |
1134 | |
1135 | struct database_dyn *db = reqinfo[req->type].db; |
1136 | |
1137 | /* See whether we can service the request from the cache. */ |
1138 | if (__builtin_expect (reqinfo[req->type].data_request, true)) |
1139 | { |
1140 | if (__builtin_expect (debug_level, 0) > 0) |
1141 | { |
1142 | if (req->type == GETHOSTBYADDR || req->type == GETHOSTBYADDRv6) |
1143 | { |
1144 | char buf[INET6_ADDRSTRLEN]; |
1145 | |
1146 | dbg_log ("\t%s (%s)" , serv2str[req->type], |
1147 | inet_ntop (req->type == GETHOSTBYADDR |
1148 | ? AF_INET : AF_INET6, |
1149 | key, buf, sizeof (buf))); |
1150 | } |
1151 | else |
1152 | dbg_log ("\t%s (%s)" , serv2str[req->type], (char *) key); |
1153 | } |
1154 | |
1155 | /* Is this service enabled? */ |
1156 | if (__glibc_unlikely (!db->enabled)) |
1157 | { |
1158 | /* No, sent the prepared record. */ |
1159 | if (TEMP_FAILURE_RETRY (send (fd, db->disabled_iov->iov_base, |
1160 | db->disabled_iov->iov_len, |
1161 | MSG_NOSIGNAL)) |
1162 | != (ssize_t) db->disabled_iov->iov_len |
1163 | && __builtin_expect (debug_level, 0) > 0) |
1164 | { |
1165 | /* We have problems sending the result. */ |
1166 | char buf[256]; |
1167 | dbg_log (_("cannot write result: %s" ), |
1168 | strerror_r (errno, buf, sizeof (buf))); |
1169 | } |
1170 | |
1171 | return; |
1172 | } |
1173 | |
1174 | /* Be sure we can read the data. */ |
1175 | if (__glibc_unlikely (pthread_rwlock_tryrdlock (&db->lock) != 0)) |
1176 | { |
1177 | ++db->head->rdlockdelayed; |
1178 | pthread_rwlock_rdlock (&db->lock); |
1179 | } |
1180 | |
1181 | /* See whether we can handle it from the cache. */ |
1182 | struct datahead *cached; |
1183 | cached = (struct datahead *) cache_search (req->type, key, req->key_len, |
1184 | db, uid); |
1185 | if (cached != NULL) |
1186 | { |
1187 | /* Hurray it's in the cache. */ |
1188 | ssize_t nwritten; |
1189 | |
1190 | #ifdef HAVE_SENDFILE |
1191 | if (__glibc_likely (db->mmap_used)) |
1192 | { |
1193 | assert (db->wr_fd != -1); |
1194 | assert ((char *) cached->data > (char *) db->data); |
1195 | assert ((char *) cached->data - (char *) db->head |
1196 | + cached->recsize |
1197 | <= (sizeof (struct database_pers_head) |
1198 | + db->head->module * sizeof (ref_t) |
1199 | + db->head->data_size)); |
1200 | nwritten = sendfileall (fd, db->wr_fd, |
1201 | (char *) cached->data |
1202 | - (char *) db->head, cached->recsize); |
1203 | # ifndef __ASSUME_SENDFILE |
1204 | if (nwritten == -1 && errno == ENOSYS) |
1205 | goto use_write; |
1206 | # endif |
1207 | } |
1208 | else |
1209 | # ifndef __ASSUME_SENDFILE |
1210 | use_write: |
1211 | # endif |
1212 | #endif |
1213 | nwritten = writeall (fd, cached->data, cached->recsize); |
1214 | |
1215 | if (nwritten != cached->recsize |
1216 | && __builtin_expect (debug_level, 0) > 0) |
1217 | { |
1218 | /* We have problems sending the result. */ |
1219 | char buf[256]; |
1220 | dbg_log (_("cannot write result: %s" ), |
1221 | strerror_r (errno, buf, sizeof (buf))); |
1222 | } |
1223 | |
1224 | pthread_rwlock_unlock (&db->lock); |
1225 | |
1226 | return; |
1227 | } |
1228 | |
1229 | pthread_rwlock_unlock (&db->lock); |
1230 | } |
1231 | else if (__builtin_expect (debug_level, 0) > 0) |
1232 | { |
1233 | if (req->type == INVALIDATE) |
1234 | dbg_log ("\t%s (%s)" , serv2str[req->type], (char *) key); |
1235 | else |
1236 | dbg_log ("\t%s" , serv2str[req->type]); |
1237 | } |
1238 | |
1239 | /* Handle the request. */ |
1240 | switch (req->type) |
1241 | { |
1242 | case GETPWBYNAME: |
1243 | addpwbyname (db, fd, req, key, uid); |
1244 | break; |
1245 | |
1246 | case GETPWBYUID: |
1247 | addpwbyuid (db, fd, req, key, uid); |
1248 | break; |
1249 | |
1250 | case GETGRBYNAME: |
1251 | addgrbyname (db, fd, req, key, uid); |
1252 | break; |
1253 | |
1254 | case GETGRBYGID: |
1255 | addgrbygid (db, fd, req, key, uid); |
1256 | break; |
1257 | |
1258 | case GETHOSTBYNAME: |
1259 | addhstbyname (db, fd, req, key, uid); |
1260 | break; |
1261 | |
1262 | case GETHOSTBYNAMEv6: |
1263 | addhstbynamev6 (db, fd, req, key, uid); |
1264 | break; |
1265 | |
1266 | case GETHOSTBYADDR: |
1267 | addhstbyaddr (db, fd, req, key, uid); |
1268 | break; |
1269 | |
1270 | case GETHOSTBYADDRv6: |
1271 | addhstbyaddrv6 (db, fd, req, key, uid); |
1272 | break; |
1273 | |
1274 | case GETAI: |
1275 | addhstai (db, fd, req, key, uid); |
1276 | break; |
1277 | |
1278 | case INITGROUPS: |
1279 | addinitgroups (db, fd, req, key, uid); |
1280 | break; |
1281 | |
1282 | case GETSERVBYNAME: |
1283 | addservbyname (db, fd, req, key, uid); |
1284 | break; |
1285 | |
1286 | case GETSERVBYPORT: |
1287 | addservbyport (db, fd, req, key, uid); |
1288 | break; |
1289 | |
1290 | case GETNETGRENT: |
1291 | addgetnetgrent (db, fd, req, key, uid); |
1292 | break; |
1293 | |
1294 | case INNETGR: |
1295 | addinnetgr (db, fd, req, key, uid); |
1296 | break; |
1297 | |
1298 | case GETSTAT: |
1299 | case SHUTDOWN: |
1300 | case INVALIDATE: |
1301 | { |
1302 | /* Get the callers credentials. */ |
1303 | #ifdef SO_PEERCRED |
1304 | struct ucred caller; |
1305 | socklen_t optlen = sizeof (caller); |
1306 | |
1307 | if (getsockopt (fd, SOL_SOCKET, SO_PEERCRED, &caller, &optlen) < 0) |
1308 | { |
1309 | char buf[256]; |
1310 | |
1311 | dbg_log (_("error getting caller's id: %s" ), |
1312 | strerror_r (errno, buf, sizeof (buf))); |
1313 | break; |
1314 | } |
1315 | |
1316 | uid = caller.uid; |
1317 | #else |
1318 | /* Some systems have no SO_PEERCRED implementation. They don't |
1319 | care about security so we don't as well. */ |
1320 | uid = 0; |
1321 | #endif |
1322 | } |
1323 | |
1324 | /* Accept shutdown, getstat and invalidate only from root. For |
1325 | the stat call also allow the user specified in the config file. */ |
1326 | if (req->type == GETSTAT) |
1327 | { |
1328 | if (uid == 0 || uid == stat_uid) |
1329 | send_stats (fd, dbs); |
1330 | } |
1331 | else if (uid == 0) |
1332 | { |
1333 | if (req->type == INVALIDATE) |
1334 | invalidate_cache (key, fd); |
1335 | else |
1336 | termination_handler (0); |
1337 | } |
1338 | break; |
1339 | |
1340 | case GETFDPW: |
1341 | case GETFDGR: |
1342 | case GETFDHST: |
1343 | case GETFDSERV: |
1344 | case GETFDNETGR: |
1345 | #ifdef SCM_RIGHTS |
1346 | send_ro_fd (reqinfo[req->type].db, key, fd); |
1347 | #endif |
1348 | break; |
1349 | |
1350 | default: |
1351 | /* Ignore the command, it's nothing we know. */ |
1352 | break; |
1353 | } |
1354 | } |
1355 | |
1356 | |
1357 | /* Restart the process. */ |
1358 | static void |
1359 | restart (void) |
1360 | { |
1361 | /* First determine the parameters. We do not use the parameters |
1362 | passed to main() since in case nscd is started by running the |
1363 | dynamic linker this will not work. Yes, this is not the usual |
1364 | case but nscd is part of glibc and we occasionally do this. */ |
1365 | size_t buflen = 1024; |
1366 | char *buf = alloca (buflen); |
1367 | size_t readlen = 0; |
1368 | int fd = open ("/proc/self/cmdline" , O_RDONLY); |
1369 | if (fd == -1) |
1370 | { |
1371 | dbg_log (_("\ |
1372 | cannot open /proc/self/cmdline: %s; disabling paranoia mode" ), |
1373 | strerror (errno)); |
1374 | |
1375 | paranoia = 0; |
1376 | return; |
1377 | } |
1378 | |
1379 | while (1) |
1380 | { |
1381 | ssize_t n = TEMP_FAILURE_RETRY (read (fd, buf + readlen, |
1382 | buflen - readlen)); |
1383 | if (n == -1) |
1384 | { |
1385 | dbg_log (_("\ |
1386 | cannot read /proc/self/cmdline: %s; disabling paranoia mode" ), |
1387 | strerror (errno)); |
1388 | |
1389 | close (fd); |
1390 | paranoia = 0; |
1391 | return; |
1392 | } |
1393 | |
1394 | readlen += n; |
1395 | |
1396 | if (readlen < buflen) |
1397 | break; |
1398 | |
1399 | /* We might have to extend the buffer. */ |
1400 | size_t old_buflen = buflen; |
1401 | char *newp = extend_alloca (buf, buflen, 2 * buflen); |
1402 | buf = memmove (newp, buf, old_buflen); |
1403 | } |
1404 | |
1405 | close (fd); |
1406 | |
1407 | /* Parse the command line. Worst case scenario: every two |
1408 | characters form one parameter (one character plus NUL). */ |
1409 | char **argv = alloca ((readlen / 2 + 1) * sizeof (argv[0])); |
1410 | int argc = 0; |
1411 | |
1412 | char *cp = buf; |
1413 | while (cp < buf + readlen) |
1414 | { |
1415 | argv[argc++] = cp; |
1416 | cp = (char *) rawmemchr (cp, '\0') + 1; |
1417 | } |
1418 | argv[argc] = NULL; |
1419 | |
1420 | /* Second, change back to the old user if we changed it. */ |
1421 | if (server_user != NULL) |
1422 | { |
1423 | if (setresuid (old_uid, old_uid, old_uid) != 0) |
1424 | { |
1425 | dbg_log (_("\ |
1426 | cannot change to old UID: %s; disabling paranoia mode" ), |
1427 | strerror (errno)); |
1428 | |
1429 | paranoia = 0; |
1430 | return; |
1431 | } |
1432 | |
1433 | if (setresgid (old_gid, old_gid, old_gid) != 0) |
1434 | { |
1435 | dbg_log (_("\ |
1436 | cannot change to old GID: %s; disabling paranoia mode" ), |
1437 | strerror (errno)); |
1438 | |
1439 | ignore_value (setuid (server_uid)); |
1440 | paranoia = 0; |
1441 | return; |
1442 | } |
1443 | } |
1444 | |
1445 | /* Next change back to the old working directory. */ |
1446 | if (chdir (oldcwd) == -1) |
1447 | { |
1448 | dbg_log (_("\ |
1449 | cannot change to old working directory: %s; disabling paranoia mode" ), |
1450 | strerror (errno)); |
1451 | |
1452 | if (server_user != NULL) |
1453 | { |
1454 | ignore_value (setuid (server_uid)); |
1455 | ignore_value (setgid (server_gid)); |
1456 | } |
1457 | paranoia = 0; |
1458 | return; |
1459 | } |
1460 | |
1461 | /* Synchronize memory. */ |
1462 | int32_t certainly[lastdb]; |
1463 | for (int cnt = 0; cnt < lastdb; ++cnt) |
1464 | if (dbs[cnt].enabled) |
1465 | { |
1466 | /* Make sure nobody keeps using the database. */ |
1467 | dbs[cnt].head->timestamp = 0; |
1468 | certainly[cnt] = dbs[cnt].head->nscd_certainly_running; |
1469 | dbs[cnt].head->nscd_certainly_running = 0; |
1470 | |
1471 | if (dbs[cnt].persistent) |
1472 | // XXX async OK? |
1473 | msync (dbs[cnt].head, dbs[cnt].memsize, MS_ASYNC); |
1474 | } |
1475 | |
1476 | /* The preparations are done. */ |
1477 | #ifdef PATH_MAX |
1478 | char pathbuf[PATH_MAX]; |
1479 | #else |
1480 | char pathbuf[256]; |
1481 | #endif |
1482 | /* Try to exec the real nscd program so the process name (as reported |
1483 | in /proc/PID/status) will be 'nscd', but fall back to /proc/self/exe |
1484 | if readlink or the exec with the result of the readlink call fails. */ |
1485 | ssize_t n = readlink ("/proc/self/exe" , pathbuf, sizeof (pathbuf) - 1); |
1486 | if (n != -1) |
1487 | { |
1488 | pathbuf[n] = '\0'; |
1489 | execv (pathbuf, argv); |
1490 | } |
1491 | execv ("/proc/self/exe" , argv); |
1492 | |
1493 | /* If we come here, we will never be able to re-exec. */ |
1494 | dbg_log (_("re-exec failed: %s; disabling paranoia mode" ), |
1495 | strerror (errno)); |
1496 | |
1497 | if (server_user != NULL) |
1498 | { |
1499 | ignore_value (setuid (server_uid)); |
1500 | ignore_value (setgid (server_gid)); |
1501 | } |
1502 | if (chdir ("/" ) != 0) |
1503 | dbg_log (_("cannot change current working directory to \"/\": %s" ), |
1504 | strerror (errno)); |
1505 | paranoia = 0; |
1506 | |
1507 | /* Reenable the databases. */ |
1508 | time_t now = time (NULL); |
1509 | for (int cnt = 0; cnt < lastdb; ++cnt) |
1510 | if (dbs[cnt].enabled) |
1511 | { |
1512 | dbs[cnt].head->timestamp = now; |
1513 | dbs[cnt].head->nscd_certainly_running = certainly[cnt]; |
1514 | } |
1515 | } |
1516 | |
1517 | |
1518 | /* List of file descriptors. */ |
1519 | struct fdlist |
1520 | { |
1521 | int fd; |
1522 | struct fdlist *next; |
1523 | }; |
1524 | /* Memory allocated for the list. */ |
1525 | static struct fdlist *fdlist; |
1526 | /* List of currently ready-to-read file descriptors. */ |
1527 | static struct fdlist *readylist; |
1528 | |
1529 | /* Conditional variable and mutex to signal availability of entries in |
1530 | READYLIST. The condvar is initialized dynamically since we might |
1531 | use a different clock depending on availability. */ |
1532 | static pthread_cond_t readylist_cond = PTHREAD_COND_INITIALIZER; |
1533 | static pthread_mutex_t readylist_lock = PTHREAD_MUTEX_INITIALIZER; |
1534 | |
1535 | /* The clock to use with the condvar. */ |
1536 | static clockid_t timeout_clock = CLOCK_REALTIME; |
1537 | |
1538 | /* Number of threads ready to handle the READYLIST. */ |
1539 | static unsigned long int nready; |
1540 | |
1541 | |
1542 | /* Function for the clean-up threads. */ |
1543 | static void * |
1544 | __attribute__ ((__noreturn__)) |
1545 | nscd_run_prune (void *p) |
1546 | { |
1547 | const long int my_number = (long int) p; |
1548 | assert (dbs[my_number].enabled); |
1549 | |
1550 | int dont_need_update = setup_thread (&dbs[my_number]); |
1551 | |
1552 | time_t now = time (NULL); |
1553 | |
1554 | /* We are running. */ |
1555 | dbs[my_number].head->timestamp = now; |
1556 | |
1557 | struct timespec prune_ts; |
1558 | if (__glibc_unlikely (clock_gettime (timeout_clock, &prune_ts) == -1)) |
1559 | /* Should never happen. */ |
1560 | abort (); |
1561 | |
1562 | /* Compute the initial timeout time. Prevent all the timers to go |
1563 | off at the same time by adding a db-based value. */ |
1564 | prune_ts.tv_sec += CACHE_PRUNE_INTERVAL + my_number; |
1565 | dbs[my_number].wakeup_time = now + CACHE_PRUNE_INTERVAL + my_number; |
1566 | |
1567 | pthread_mutex_t *prune_lock = &dbs[my_number].prune_lock; |
1568 | pthread_mutex_t *prune_run_lock = &dbs[my_number].prune_run_lock; |
1569 | pthread_cond_t *prune_cond = &dbs[my_number].prune_cond; |
1570 | |
1571 | pthread_mutex_lock (prune_lock); |
1572 | while (1) |
1573 | { |
1574 | /* Wait, but not forever. */ |
1575 | int e = 0; |
1576 | if (! dbs[my_number].clear_cache) |
1577 | e = pthread_cond_timedwait (prune_cond, prune_lock, &prune_ts); |
1578 | assert (__builtin_expect (e == 0 || e == ETIMEDOUT, 1)); |
1579 | |
1580 | time_t next_wait; |
1581 | now = time (NULL); |
1582 | if (e == ETIMEDOUT || now >= dbs[my_number].wakeup_time |
1583 | || dbs[my_number].clear_cache) |
1584 | { |
1585 | /* We will determine the new timout values based on the |
1586 | cache content. Should there be concurrent additions to |
1587 | the cache which are not accounted for in the cache |
1588 | pruning we want to know about it. Therefore set the |
1589 | timeout to the maximum. It will be descreased when adding |
1590 | new entries to the cache, if necessary. */ |
1591 | dbs[my_number].wakeup_time = MAX_TIMEOUT_VALUE; |
1592 | |
1593 | /* Unconditionally reset the flag. */ |
1594 | time_t prune_now = dbs[my_number].clear_cache ? LONG_MAX : now; |
1595 | dbs[my_number].clear_cache = 0; |
1596 | |
1597 | pthread_mutex_unlock (prune_lock); |
1598 | |
1599 | /* We use a separate lock for running the prune function (instead |
1600 | of keeping prune_lock locked) because this enables concurrent |
1601 | invocations of cache_add which might modify the timeout value. */ |
1602 | pthread_mutex_lock (prune_run_lock); |
1603 | next_wait = prune_cache (&dbs[my_number], prune_now, -1); |
1604 | pthread_mutex_unlock (prune_run_lock); |
1605 | |
1606 | next_wait = MAX (next_wait, CACHE_PRUNE_INTERVAL); |
1607 | /* If clients cannot determine for sure whether nscd is running |
1608 | we need to wake up occasionally to update the timestamp. |
1609 | Wait 90% of the update period. */ |
1610 | #define UPDATE_MAPPING_TIMEOUT (MAPPING_TIMEOUT * 9 / 10) |
1611 | if (__glibc_unlikely (! dont_need_update)) |
1612 | { |
1613 | next_wait = MIN (UPDATE_MAPPING_TIMEOUT, next_wait); |
1614 | dbs[my_number].head->timestamp = now; |
1615 | } |
1616 | |
1617 | pthread_mutex_lock (prune_lock); |
1618 | |
1619 | /* Make it known when we will wake up again. */ |
1620 | if (now + next_wait < dbs[my_number].wakeup_time) |
1621 | dbs[my_number].wakeup_time = now + next_wait; |
1622 | else |
1623 | next_wait = dbs[my_number].wakeup_time - now; |
1624 | } |
1625 | else |
1626 | /* The cache was just pruned. Do not do it again now. Just |
1627 | use the new timeout value. */ |
1628 | next_wait = dbs[my_number].wakeup_time - now; |
1629 | |
1630 | if (clock_gettime (timeout_clock, &prune_ts) == -1) |
1631 | /* Should never happen. */ |
1632 | abort (); |
1633 | |
1634 | /* Compute next timeout time. */ |
1635 | prune_ts.tv_sec += next_wait; |
1636 | } |
1637 | } |
1638 | |
1639 | |
1640 | /* This is the main loop. It is replicated in different threads but |
1641 | the use of the ready list makes sure only one thread handles an |
1642 | incoming connection. */ |
1643 | static void * |
1644 | __attribute__ ((__noreturn__)) |
1645 | nscd_run_worker (void *p) |
1646 | { |
1647 | char buf[256]; |
1648 | |
1649 | /* Initial locking. */ |
1650 | pthread_mutex_lock (&readylist_lock); |
1651 | |
1652 | /* One more thread available. */ |
1653 | ++nready; |
1654 | |
1655 | while (1) |
1656 | { |
1657 | while (readylist == NULL) |
1658 | pthread_cond_wait (&readylist_cond, &readylist_lock); |
1659 | |
1660 | struct fdlist *it = readylist->next; |
1661 | if (readylist->next == readylist) |
1662 | /* Just one entry on the list. */ |
1663 | readylist = NULL; |
1664 | else |
1665 | readylist->next = it->next; |
1666 | |
1667 | /* Extract the information and mark the record ready to be used |
1668 | again. */ |
1669 | int fd = it->fd; |
1670 | it->next = NULL; |
1671 | |
1672 | /* One more thread available. */ |
1673 | --nready; |
1674 | |
1675 | /* We are done with the list. */ |
1676 | pthread_mutex_unlock (&readylist_lock); |
1677 | |
1678 | #ifndef __ASSUME_ACCEPT4 |
1679 | if (have_accept4 < 0) |
1680 | { |
1681 | /* We do not want to block on a short read or so. */ |
1682 | int fl = fcntl (fd, F_GETFL); |
1683 | if (fl == -1 || fcntl (fd, F_SETFL, fl | O_NONBLOCK) == -1) |
1684 | goto close_and_out; |
1685 | } |
1686 | #endif |
1687 | |
1688 | /* Now read the request. */ |
1689 | request_header req; |
1690 | if (__builtin_expect (TEMP_FAILURE_RETRY (read (fd, &req, sizeof (req))) |
1691 | != sizeof (req), 0)) |
1692 | { |
1693 | /* We failed to read data. Note that this also might mean we |
1694 | failed because we would have blocked. */ |
1695 | if (debug_level > 0) |
1696 | dbg_log (_("short read while reading request: %s" ), |
1697 | strerror_r (errno, buf, sizeof (buf))); |
1698 | goto close_and_out; |
1699 | } |
1700 | |
1701 | /* Check whether this is a valid request type. */ |
1702 | if (req.type < GETPWBYNAME || req.type >= LASTREQ) |
1703 | goto close_and_out; |
1704 | |
1705 | /* Some systems have no SO_PEERCRED implementation. They don't |
1706 | care about security so we don't as well. */ |
1707 | uid_t uid = -1; |
1708 | #ifdef SO_PEERCRED |
1709 | pid_t pid = 0; |
1710 | |
1711 | if (__glibc_unlikely (debug_level > 0)) |
1712 | { |
1713 | struct ucred caller; |
1714 | socklen_t optlen = sizeof (caller); |
1715 | |
1716 | if (getsockopt (fd, SOL_SOCKET, SO_PEERCRED, &caller, &optlen) == 0) |
1717 | pid = caller.pid; |
1718 | } |
1719 | #else |
1720 | const pid_t pid = 0; |
1721 | #endif |
1722 | |
1723 | /* It should not be possible to crash the nscd with a silly |
1724 | request (i.e., a terribly large key). We limit the size to 1kb. */ |
1725 | if (__builtin_expect (req.key_len, 1) < 0 |
1726 | || __builtin_expect (req.key_len, 1) > MAXKEYLEN) |
1727 | { |
1728 | if (debug_level > 0) |
1729 | dbg_log (_("key length in request too long: %d" ), req.key_len); |
1730 | } |
1731 | else |
1732 | { |
1733 | /* Get the key. */ |
1734 | char keybuf[MAXKEYLEN + 1]; |
1735 | |
1736 | if (__builtin_expect (TEMP_FAILURE_RETRY (read (fd, keybuf, |
1737 | req.key_len)) |
1738 | != req.key_len, 0)) |
1739 | { |
1740 | /* Again, this can also mean we would have blocked. */ |
1741 | if (debug_level > 0) |
1742 | dbg_log (_("short read while reading request key: %s" ), |
1743 | strerror_r (errno, buf, sizeof (buf))); |
1744 | goto close_and_out; |
1745 | } |
1746 | keybuf[req.key_len] = '\0'; |
1747 | |
1748 | if (__builtin_expect (debug_level, 0) > 0) |
1749 | { |
1750 | #ifdef SO_PEERCRED |
1751 | if (pid != 0) |
1752 | dbg_log (_("\ |
1753 | handle_request: request received (Version = %d) from PID %ld" ), |
1754 | req.version, (long int) pid); |
1755 | else |
1756 | #endif |
1757 | dbg_log (_("\ |
1758 | handle_request: request received (Version = %d)" ), req.version); |
1759 | } |
1760 | |
1761 | /* Phew, we got all the data, now process it. */ |
1762 | handle_request (fd, &req, keybuf, uid, pid); |
1763 | } |
1764 | |
1765 | close_and_out: |
1766 | /* We are done. */ |
1767 | close (fd); |
1768 | |
1769 | /* Re-locking. */ |
1770 | pthread_mutex_lock (&readylist_lock); |
1771 | |
1772 | /* One more thread available. */ |
1773 | ++nready; |
1774 | } |
1775 | /* NOTREACHED */ |
1776 | } |
1777 | |
1778 | |
1779 | static unsigned int nconns; |
1780 | |
1781 | static void |
1782 | fd_ready (int fd) |
1783 | { |
1784 | pthread_mutex_lock (&readylist_lock); |
1785 | |
1786 | /* Find an empty entry in FDLIST. */ |
1787 | size_t inner; |
1788 | for (inner = 0; inner < nconns; ++inner) |
1789 | if (fdlist[inner].next == NULL) |
1790 | break; |
1791 | assert (inner < nconns); |
1792 | |
1793 | fdlist[inner].fd = fd; |
1794 | |
1795 | if (readylist == NULL) |
1796 | readylist = fdlist[inner].next = &fdlist[inner]; |
1797 | else |
1798 | { |
1799 | fdlist[inner].next = readylist->next; |
1800 | readylist = readylist->next = &fdlist[inner]; |
1801 | } |
1802 | |
1803 | bool do_signal = true; |
1804 | if (__glibc_unlikely (nready == 0)) |
1805 | { |
1806 | ++client_queued; |
1807 | do_signal = false; |
1808 | |
1809 | /* Try to start another thread to help out. */ |
1810 | pthread_t th; |
1811 | if (nthreads < max_nthreads |
1812 | && pthread_create (&th, &attr, nscd_run_worker, |
1813 | (void *) (long int) nthreads) == 0) |
1814 | { |
1815 | /* We got another thread. */ |
1816 | ++nthreads; |
1817 | /* The new thread might need a kick. */ |
1818 | do_signal = true; |
1819 | } |
1820 | |
1821 | } |
1822 | |
1823 | pthread_mutex_unlock (&readylist_lock); |
1824 | |
1825 | /* Tell one of the worker threads there is work to do. */ |
1826 | if (do_signal) |
1827 | pthread_cond_signal (&readylist_cond); |
1828 | } |
1829 | |
1830 | |
1831 | /* Check whether restarting should happen. */ |
1832 | static bool |
1833 | restart_p (time_t now) |
1834 | { |
1835 | return (paranoia && readylist == NULL && nready == nthreads |
1836 | && now >= restart_time); |
1837 | } |
1838 | |
1839 | |
1840 | /* Array for times a connection was accepted. */ |
1841 | static time_t *starttime; |
1842 | |
1843 | #ifdef HAVE_INOTIFY |
1844 | /* Inotify event for changed file. */ |
1845 | union __inev |
1846 | { |
1847 | struct inotify_event i; |
1848 | # ifndef PATH_MAX |
1849 | # define PATH_MAX 1024 |
1850 | # endif |
1851 | char buf[sizeof (struct inotify_event) + PATH_MAX]; |
1852 | }; |
1853 | |
1854 | /* Returns 0 if the file is there otherwise -1. */ |
1855 | int |
1856 | check_file (struct traced_file *finfo) |
1857 | { |
1858 | struct stat64 st; |
1859 | /* We could check mtime and if different re-add |
1860 | the watches, and invalidate the database, but we |
1861 | don't because we are called from inotify_check_files |
1862 | which should be doing that work. If sufficient inotify |
1863 | events were lost then the next pruning or invalidation |
1864 | will do the stat and mtime check. We don't do it here to |
1865 | keep the logic simple. */ |
1866 | if (stat64 (finfo->fname, &st) < 0) |
1867 | return -1; |
1868 | return 0; |
1869 | } |
1870 | |
1871 | /* Process the inotify event in INEV. If the event matches any of the files |
1872 | registered with a database then mark that database as requiring its cache |
1873 | to be cleared. We indicate the cache needs clearing by setting |
1874 | TO_CLEAR[DBCNT] to true for the matching database. */ |
1875 | static void |
1876 | inotify_check_files (bool *to_clear, union __inev *inev) |
1877 | { |
1878 | /* Check which of the files changed. */ |
1879 | for (size_t dbcnt = 0; dbcnt < lastdb; ++dbcnt) |
1880 | { |
1881 | struct traced_file *finfo = dbs[dbcnt].traced_files; |
1882 | |
1883 | while (finfo != NULL) |
1884 | { |
1885 | /* The configuration file was moved or deleted. |
1886 | We stop watching it at that point, and reinitialize. */ |
1887 | if (finfo->inotify_descr[TRACED_FILE] == inev->i.wd |
1888 | && ((inev->i.mask & IN_MOVE_SELF) |
1889 | || (inev->i.mask & IN_DELETE_SELF) |
1890 | || (inev->i.mask & IN_IGNORED))) |
1891 | { |
1892 | int ret; |
1893 | bool moved = (inev->i.mask & IN_MOVE_SELF) != 0; |
1894 | |
1895 | if (check_file (finfo) == 0) |
1896 | { |
1897 | dbg_log (_("ignored inotify event for `%s` (file exists)" ), |
1898 | finfo->fname); |
1899 | return; |
1900 | } |
1901 | |
1902 | dbg_log (_("monitored file `%s` was %s, removing watch" ), |
1903 | finfo->fname, moved ? "moved" : "deleted" ); |
1904 | /* File was moved out, remove the watch. Watches are |
1905 | automatically removed when the file is deleted. */ |
1906 | if (moved) |
1907 | { |
1908 | ret = inotify_rm_watch (inotify_fd, inev->i.wd); |
1909 | if (ret < 0) |
1910 | dbg_log (_("failed to remove file watch `%s`: %s" ), |
1911 | finfo->fname, strerror (errno)); |
1912 | } |
1913 | finfo->inotify_descr[TRACED_FILE] = -1; |
1914 | to_clear[dbcnt] = true; |
1915 | if (finfo->call_res_init) |
1916 | res_init (); |
1917 | return; |
1918 | } |
1919 | /* The configuration file was open for writing and has just closed. |
1920 | We reset the cache and reinitialize. */ |
1921 | if (finfo->inotify_descr[TRACED_FILE] == inev->i.wd |
1922 | && inev->i.mask & IN_CLOSE_WRITE) |
1923 | { |
1924 | /* Mark cache as needing to be cleared and reinitialize. */ |
1925 | dbg_log (_("monitored file `%s` was written to" ), finfo->fname); |
1926 | to_clear[dbcnt] = true; |
1927 | if (finfo->call_res_init) |
1928 | res_init (); |
1929 | return; |
1930 | } |
1931 | /* The parent directory was moved or deleted. We trigger one last |
1932 | invalidation. At the next pruning or invalidation we may add |
1933 | this watch back if the file is present again. */ |
1934 | if (finfo->inotify_descr[TRACED_DIR] == inev->i.wd |
1935 | && ((inev->i.mask & IN_DELETE_SELF) |
1936 | || (inev->i.mask & IN_MOVE_SELF) |
1937 | || (inev->i.mask & IN_IGNORED))) |
1938 | { |
1939 | bool moved = (inev->i.mask & IN_MOVE_SELF) != 0; |
1940 | /* The directory watch may have already been removed |
1941 | but we don't know so we just remove it again and |
1942 | ignore the error. Then we remove the file watch. |
1943 | Note: watches are automatically removed for deleted |
1944 | files. */ |
1945 | if (moved) |
1946 | inotify_rm_watch (inotify_fd, inev->i.wd); |
1947 | if (finfo->inotify_descr[TRACED_FILE] != -1) |
1948 | { |
1949 | dbg_log (_("monitored parent directory `%s` was %s, removing watch on `%s`" ), |
1950 | finfo->dname, moved ? "moved" : "deleted" , finfo->fname); |
1951 | if (inotify_rm_watch (inotify_fd, finfo->inotify_descr[TRACED_FILE]) < 0) |
1952 | dbg_log (_("failed to remove file watch `%s`: %s" ), |
1953 | finfo->dname, strerror (errno)); |
1954 | } |
1955 | finfo->inotify_descr[TRACED_FILE] = -1; |
1956 | finfo->inotify_descr[TRACED_DIR] = -1; |
1957 | to_clear[dbcnt] = true; |
1958 | if (finfo->call_res_init) |
1959 | res_init (); |
1960 | /* Continue to the next entry since this might be the |
1961 | parent directory for multiple registered files and |
1962 | we want to remove watches for all registered files. */ |
1963 | continue; |
1964 | } |
1965 | /* The parent directory had a create or moved to event. */ |
1966 | if (finfo->inotify_descr[TRACED_DIR] == inev->i.wd |
1967 | && ((inev->i.mask & IN_MOVED_TO) |
1968 | || (inev->i.mask & IN_CREATE)) |
1969 | && strcmp (inev->i.name, finfo->sfname) == 0) |
1970 | { |
1971 | /* We detected a directory change. We look for the creation |
1972 | of the file we are tracking or the move of the same file |
1973 | into the directory. */ |
1974 | int ret; |
1975 | dbg_log (_("monitored file `%s` was %s, adding watch" ), |
1976 | finfo->fname, |
1977 | inev->i.mask & IN_CREATE ? "created" : "moved into place" ); |
1978 | /* File was moved in or created. Regenerate the watch. */ |
1979 | if (finfo->inotify_descr[TRACED_FILE] != -1) |
1980 | inotify_rm_watch (inotify_fd, |
1981 | finfo->inotify_descr[TRACED_FILE]); |
1982 | |
1983 | ret = inotify_add_watch (inotify_fd, |
1984 | finfo->fname, |
1985 | TRACED_FILE_MASK); |
1986 | if (ret < 0) |
1987 | dbg_log (_("failed to add file watch `%s`: %s" ), |
1988 | finfo->fname, strerror (errno)); |
1989 | |
1990 | finfo->inotify_descr[TRACED_FILE] = ret; |
1991 | |
1992 | /* The file is new or moved so mark cache as needing to |
1993 | be cleared and reinitialize. */ |
1994 | to_clear[dbcnt] = true; |
1995 | if (finfo->call_res_init) |
1996 | res_init (); |
1997 | |
1998 | /* Done re-adding the watch. Don't return, we may still |
1999 | have other files in this same directory, same watch |
2000 | descriptor, and need to process them. */ |
2001 | } |
2002 | /* Other events are ignored, and we move on to the next file. */ |
2003 | finfo = finfo->next; |
2004 | } |
2005 | } |
2006 | } |
2007 | |
2008 | /* If an entry in the array of booleans TO_CLEAR is TRUE then clear the cache |
2009 | for the associated database, otherwise do nothing. The TO_CLEAR array must |
2010 | have LASTDB entries. */ |
2011 | static inline void |
2012 | clear_db_cache (bool *to_clear) |
2013 | { |
2014 | for (size_t dbcnt = 0; dbcnt < lastdb; ++dbcnt) |
2015 | if (to_clear[dbcnt]) |
2016 | { |
2017 | pthread_mutex_lock (&dbs[dbcnt].prune_lock); |
2018 | dbs[dbcnt].clear_cache = 1; |
2019 | pthread_mutex_unlock (&dbs[dbcnt].prune_lock); |
2020 | pthread_cond_signal (&dbs[dbcnt].prune_cond); |
2021 | } |
2022 | } |
2023 | |
2024 | int |
2025 | handle_inotify_events (void) |
2026 | { |
2027 | bool to_clear[lastdb] = { false, }; |
2028 | union __inev inev; |
2029 | |
2030 | /* Read all inotify events for files registered via |
2031 | register_traced_file(). */ |
2032 | while (1) |
2033 | { |
2034 | /* Potentially read multiple events into buf. */ |
2035 | ssize_t nb = TEMP_FAILURE_RETRY (read (inotify_fd, |
2036 | &inev.buf, |
2037 | sizeof (inev))); |
2038 | if (nb < (ssize_t) sizeof (struct inotify_event)) |
2039 | { |
2040 | /* Not even 1 event. */ |
2041 | if (__glibc_unlikely (nb == -1 && errno != EAGAIN)) |
2042 | return -1; |
2043 | /* Done reading events that are ready. */ |
2044 | break; |
2045 | } |
2046 | /* Process all events. The normal inotify interface delivers |
2047 | complete events on a read and never a partial event. */ |
2048 | char *eptr = &inev.buf[0]; |
2049 | ssize_t count; |
2050 | while (1) |
2051 | { |
2052 | /* Check which of the files changed. */ |
2053 | inotify_check_files (to_clear, &inev); |
2054 | count = sizeof (struct inotify_event) + inev.i.len; |
2055 | eptr += count; |
2056 | nb -= count; |
2057 | if (nb >= (ssize_t) sizeof (struct inotify_event)) |
2058 | memcpy (&inev, eptr, nb); |
2059 | else |
2060 | break; |
2061 | } |
2062 | continue; |
2063 | } |
2064 | /* Actually perform the cache clearing. */ |
2065 | clear_db_cache (to_clear); |
2066 | return 0; |
2067 | } |
2068 | |
2069 | #endif |
2070 | |
2071 | static void |
2072 | __attribute__ ((__noreturn__)) |
2073 | main_loop_poll (void) |
2074 | { |
2075 | struct pollfd *conns = (struct pollfd *) xmalloc (nconns |
2076 | * sizeof (conns[0])); |
2077 | |
2078 | conns[0].fd = sock; |
2079 | conns[0].events = POLLRDNORM; |
2080 | size_t nused = 1; |
2081 | size_t firstfree = 1; |
2082 | |
2083 | #ifdef HAVE_INOTIFY |
2084 | if (inotify_fd != -1) |
2085 | { |
2086 | conns[1].fd = inotify_fd; |
2087 | conns[1].events = POLLRDNORM; |
2088 | nused = 2; |
2089 | firstfree = 2; |
2090 | } |
2091 | #endif |
2092 | |
2093 | #ifdef HAVE_NETLINK |
2094 | size_t idx_nl_status_fd = 0; |
2095 | if (nl_status_fd != -1) |
2096 | { |
2097 | idx_nl_status_fd = nused; |
2098 | conns[nused].fd = nl_status_fd; |
2099 | conns[nused].events = POLLRDNORM; |
2100 | ++nused; |
2101 | firstfree = nused; |
2102 | } |
2103 | #endif |
2104 | |
2105 | while (1) |
2106 | { |
2107 | /* Wait for any event. We wait at most a couple of seconds so |
2108 | that we can check whether we should close any of the accepted |
2109 | connections since we have not received a request. */ |
2110 | #define MAX_ACCEPT_TIMEOUT 30 |
2111 | #define MIN_ACCEPT_TIMEOUT 5 |
2112 | #define MAIN_THREAD_TIMEOUT \ |
2113 | (MAX_ACCEPT_TIMEOUT * 1000 \ |
2114 | - ((MAX_ACCEPT_TIMEOUT - MIN_ACCEPT_TIMEOUT) * 1000 * nused) / (2 * nconns)) |
2115 | |
2116 | int n = poll (conns, nused, MAIN_THREAD_TIMEOUT); |
2117 | |
2118 | time_t now = time (NULL); |
2119 | |
2120 | /* If there is a descriptor ready for reading or there is a new |
2121 | connection, process this now. */ |
2122 | if (n > 0) |
2123 | { |
2124 | if (conns[0].revents != 0) |
2125 | { |
2126 | /* We have a new incoming connection. Accept the connection. */ |
2127 | int fd; |
2128 | |
2129 | #ifndef __ASSUME_ACCEPT4 |
2130 | fd = -1; |
2131 | if (have_accept4 >= 0) |
2132 | #endif |
2133 | { |
2134 | fd = TEMP_FAILURE_RETRY (accept4 (sock, NULL, NULL, |
2135 | SOCK_NONBLOCK)); |
2136 | #ifndef __ASSUME_ACCEPT4 |
2137 | if (have_accept4 == 0) |
2138 | have_accept4 = fd != -1 || errno != ENOSYS ? 1 : -1; |
2139 | #endif |
2140 | } |
2141 | #ifndef __ASSUME_ACCEPT4 |
2142 | if (have_accept4 < 0) |
2143 | fd = TEMP_FAILURE_RETRY (accept (sock, NULL, NULL)); |
2144 | #endif |
2145 | |
2146 | /* Use the descriptor if we have not reached the limit. */ |
2147 | if (fd >= 0) |
2148 | { |
2149 | if (firstfree < nconns) |
2150 | { |
2151 | conns[firstfree].fd = fd; |
2152 | conns[firstfree].events = POLLRDNORM; |
2153 | starttime[firstfree] = now; |
2154 | if (firstfree >= nused) |
2155 | nused = firstfree + 1; |
2156 | |
2157 | do |
2158 | ++firstfree; |
2159 | while (firstfree < nused && conns[firstfree].fd != -1); |
2160 | } |
2161 | else |
2162 | /* We cannot use the connection so close it. */ |
2163 | close (fd); |
2164 | } |
2165 | |
2166 | --n; |
2167 | } |
2168 | |
2169 | size_t first = 1; |
2170 | #ifdef HAVE_INOTIFY |
2171 | if (inotify_fd != -1 && conns[1].fd == inotify_fd) |
2172 | { |
2173 | if (conns[1].revents != 0) |
2174 | { |
2175 | int ret; |
2176 | ret = handle_inotify_events (); |
2177 | if (ret == -1) |
2178 | { |
2179 | /* Something went wrong when reading the inotify |
2180 | data. Better disable inotify. */ |
2181 | dbg_log (_("disabled inotify-based monitoring after read error %d" ), errno); |
2182 | conns[1].fd = -1; |
2183 | firstfree = 1; |
2184 | if (nused == 2) |
2185 | nused = 1; |
2186 | close (inotify_fd); |
2187 | inotify_fd = -1; |
2188 | } |
2189 | --n; |
2190 | } |
2191 | |
2192 | first = 2; |
2193 | } |
2194 | #endif |
2195 | |
2196 | #ifdef HAVE_NETLINK |
2197 | if (idx_nl_status_fd != 0 && conns[idx_nl_status_fd].revents != 0) |
2198 | { |
2199 | char buf[4096]; |
2200 | /* Read all the data. We do not interpret it here. */ |
2201 | while (TEMP_FAILURE_RETRY (read (nl_status_fd, buf, |
2202 | sizeof (buf))) != -1) |
2203 | ; |
2204 | |
2205 | dbs[hstdb].head->extra_data[NSCD_HST_IDX_CONF_TIMESTAMP] |
2206 | = __bump_nl_timestamp (); |
2207 | } |
2208 | #endif |
2209 | |
2210 | for (size_t cnt = first; cnt < nused && n > 0; ++cnt) |
2211 | if (conns[cnt].revents != 0) |
2212 | { |
2213 | fd_ready (conns[cnt].fd); |
2214 | |
2215 | /* Clean up the CONNS array. */ |
2216 | conns[cnt].fd = -1; |
2217 | if (cnt < firstfree) |
2218 | firstfree = cnt; |
2219 | if (cnt == nused - 1) |
2220 | do |
2221 | --nused; |
2222 | while (conns[nused - 1].fd == -1); |
2223 | |
2224 | --n; |
2225 | } |
2226 | } |
2227 | |
2228 | /* Now find entries which have timed out. */ |
2229 | assert (nused > 0); |
2230 | |
2231 | /* We make the timeout length depend on the number of file |
2232 | descriptors currently used. */ |
2233 | #define ACCEPT_TIMEOUT \ |
2234 | (MAX_ACCEPT_TIMEOUT \ |
2235 | - ((MAX_ACCEPT_TIMEOUT - MIN_ACCEPT_TIMEOUT) * nused) / nconns) |
2236 | time_t laststart = now - ACCEPT_TIMEOUT; |
2237 | |
2238 | for (size_t cnt = nused - 1; cnt > 0; --cnt) |
2239 | { |
2240 | if (conns[cnt].fd != -1 && starttime[cnt] < laststart) |
2241 | { |
2242 | /* Remove the entry, it timed out. */ |
2243 | (void) close (conns[cnt].fd); |
2244 | conns[cnt].fd = -1; |
2245 | |
2246 | if (cnt < firstfree) |
2247 | firstfree = cnt; |
2248 | if (cnt == nused - 1) |
2249 | do |
2250 | --nused; |
2251 | while (conns[nused - 1].fd == -1); |
2252 | } |
2253 | } |
2254 | |
2255 | if (restart_p (now)) |
2256 | restart (); |
2257 | } |
2258 | } |
2259 | |
2260 | |
2261 | #ifdef HAVE_EPOLL |
2262 | static void |
2263 | main_loop_epoll (int efd) |
2264 | { |
2265 | struct epoll_event ev = { 0, }; |
2266 | int nused = 1; |
2267 | size_t highest = 0; |
2268 | |
2269 | /* Add the socket. */ |
2270 | ev.events = EPOLLRDNORM; |
2271 | ev.data.fd = sock; |
2272 | if (epoll_ctl (efd, EPOLL_CTL_ADD, sock, &ev) == -1) |
2273 | /* We cannot use epoll. */ |
2274 | return; |
2275 | |
2276 | # ifdef HAVE_INOTIFY |
2277 | if (inotify_fd != -1) |
2278 | { |
2279 | ev.events = EPOLLRDNORM; |
2280 | ev.data.fd = inotify_fd; |
2281 | if (epoll_ctl (efd, EPOLL_CTL_ADD, inotify_fd, &ev) == -1) |
2282 | /* We cannot use epoll. */ |
2283 | return; |
2284 | nused = 2; |
2285 | } |
2286 | # endif |
2287 | |
2288 | # ifdef HAVE_NETLINK |
2289 | if (nl_status_fd != -1) |
2290 | { |
2291 | ev.events = EPOLLRDNORM; |
2292 | ev.data.fd = nl_status_fd; |
2293 | if (epoll_ctl (efd, EPOLL_CTL_ADD, nl_status_fd, &ev) == -1) |
2294 | /* We cannot use epoll. */ |
2295 | return; |
2296 | } |
2297 | # endif |
2298 | |
2299 | while (1) |
2300 | { |
2301 | struct epoll_event revs[100]; |
2302 | # define nrevs (sizeof (revs) / sizeof (revs[0])) |
2303 | |
2304 | int n = epoll_wait (efd, revs, nrevs, MAIN_THREAD_TIMEOUT); |
2305 | |
2306 | time_t now = time (NULL); |
2307 | |
2308 | for (int cnt = 0; cnt < n; ++cnt) |
2309 | if (revs[cnt].data.fd == sock) |
2310 | { |
2311 | /* A new connection. */ |
2312 | int fd; |
2313 | |
2314 | # ifndef __ASSUME_ACCEPT4 |
2315 | fd = -1; |
2316 | if (have_accept4 >= 0) |
2317 | # endif |
2318 | { |
2319 | fd = TEMP_FAILURE_RETRY (accept4 (sock, NULL, NULL, |
2320 | SOCK_NONBLOCK)); |
2321 | # ifndef __ASSUME_ACCEPT4 |
2322 | if (have_accept4 == 0) |
2323 | have_accept4 = fd != -1 || errno != ENOSYS ? 1 : -1; |
2324 | # endif |
2325 | } |
2326 | # ifndef __ASSUME_ACCEPT4 |
2327 | if (have_accept4 < 0) |
2328 | fd = TEMP_FAILURE_RETRY (accept (sock, NULL, NULL)); |
2329 | # endif |
2330 | |
2331 | /* Use the descriptor if we have not reached the limit. */ |
2332 | if (fd >= 0) |
2333 | { |
2334 | /* Try to add the new descriptor. */ |
2335 | ev.data.fd = fd; |
2336 | if (fd >= nconns |
2337 | || epoll_ctl (efd, EPOLL_CTL_ADD, fd, &ev) == -1) |
2338 | /* The descriptor is too large or something went |
2339 | wrong. Close the descriptor. */ |
2340 | close (fd); |
2341 | else |
2342 | { |
2343 | /* Remember when we accepted the connection. */ |
2344 | starttime[fd] = now; |
2345 | |
2346 | if (fd > highest) |
2347 | highest = fd; |
2348 | |
2349 | ++nused; |
2350 | } |
2351 | } |
2352 | } |
2353 | # ifdef HAVE_INOTIFY |
2354 | else if (revs[cnt].data.fd == inotify_fd) |
2355 | { |
2356 | int ret; |
2357 | ret = handle_inotify_events (); |
2358 | if (ret == -1) |
2359 | { |
2360 | /* Something went wrong when reading the inotify |
2361 | data. Better disable inotify. */ |
2362 | dbg_log (_("disabled inotify-based monitoring after read error %d" ), errno); |
2363 | (void) epoll_ctl (efd, EPOLL_CTL_DEL, inotify_fd, NULL); |
2364 | close (inotify_fd); |
2365 | inotify_fd = -1; |
2366 | break; |
2367 | } |
2368 | } |
2369 | # endif |
2370 | # ifdef HAVE_NETLINK |
2371 | else if (revs[cnt].data.fd == nl_status_fd) |
2372 | { |
2373 | char buf[4096]; |
2374 | /* Read all the data. We do not interpret it here. */ |
2375 | while (TEMP_FAILURE_RETRY (read (nl_status_fd, buf, |
2376 | sizeof (buf))) != -1) |
2377 | ; |
2378 | |
2379 | __bump_nl_timestamp (); |
2380 | } |
2381 | # endif |
2382 | else |
2383 | { |
2384 | /* Remove the descriptor from the epoll descriptor. */ |
2385 | (void) epoll_ctl (efd, EPOLL_CTL_DEL, revs[cnt].data.fd, NULL); |
2386 | |
2387 | /* Get a worker to handle the request. */ |
2388 | fd_ready (revs[cnt].data.fd); |
2389 | |
2390 | /* Reset the time. */ |
2391 | starttime[revs[cnt].data.fd] = 0; |
2392 | if (revs[cnt].data.fd == highest) |
2393 | do |
2394 | --highest; |
2395 | while (highest > 0 && starttime[highest] == 0); |
2396 | |
2397 | --nused; |
2398 | } |
2399 | |
2400 | /* Now look for descriptors for accepted connections which have |
2401 | no reply in too long of a time. */ |
2402 | time_t laststart = now - ACCEPT_TIMEOUT; |
2403 | assert (starttime[sock] == 0); |
2404 | # ifdef HAVE_INOTIFY |
2405 | assert (inotify_fd == -1 || starttime[inotify_fd] == 0); |
2406 | # endif |
2407 | assert (nl_status_fd == -1 || starttime[nl_status_fd] == 0); |
2408 | for (int cnt = highest; cnt > STDERR_FILENO; --cnt) |
2409 | if (starttime[cnt] != 0 && starttime[cnt] < laststart) |
2410 | { |
2411 | /* We are waiting for this one for too long. Close it. */ |
2412 | (void) epoll_ctl (efd, EPOLL_CTL_DEL, cnt, NULL); |
2413 | |
2414 | (void) close (cnt); |
2415 | |
2416 | starttime[cnt] = 0; |
2417 | if (cnt == highest) |
2418 | --highest; |
2419 | } |
2420 | else if (cnt != sock && starttime[cnt] == 0 && cnt == highest) |
2421 | --highest; |
2422 | |
2423 | if (restart_p (now)) |
2424 | restart (); |
2425 | } |
2426 | } |
2427 | #endif |
2428 | |
2429 | |
2430 | /* Start all the threads we want. The initial process is thread no. 1. */ |
2431 | void |
2432 | start_threads (void) |
2433 | { |
2434 | /* Initialize the conditional variable we will use. The only |
2435 | non-standard attribute we might use is the clock selection. */ |
2436 | pthread_condattr_t condattr; |
2437 | pthread_condattr_init (&condattr); |
2438 | |
2439 | #if defined _POSIX_CLOCK_SELECTION && _POSIX_CLOCK_SELECTION >= 0 \ |
2440 | && defined _POSIX_MONOTONIC_CLOCK && _POSIX_MONOTONIC_CLOCK >= 0 |
2441 | /* Determine whether the monotonous clock is available. */ |
2442 | struct timespec dummy; |
2443 | # if _POSIX_MONOTONIC_CLOCK == 0 |
2444 | if (sysconf (_SC_MONOTONIC_CLOCK) > 0) |
2445 | # endif |
2446 | # if _POSIX_CLOCK_SELECTION == 0 |
2447 | if (sysconf (_SC_CLOCK_SELECTION) > 0) |
2448 | # endif |
2449 | if (clock_getres (CLOCK_MONOTONIC, &dummy) == 0 |
2450 | && pthread_condattr_setclock (&condattr, CLOCK_MONOTONIC) == 0) |
2451 | timeout_clock = CLOCK_MONOTONIC; |
2452 | #endif |
2453 | |
2454 | /* Create the attribute for the threads. They are all created |
2455 | detached. */ |
2456 | pthread_attr_init (&attr); |
2457 | pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED); |
2458 | /* Use 1MB stacks, twice as much for 64-bit architectures. */ |
2459 | pthread_attr_setstacksize (&attr, NSCD_THREAD_STACKSIZE); |
2460 | |
2461 | /* We allow less than LASTDB threads only for debugging. */ |
2462 | if (debug_level == 0) |
2463 | nthreads = MAX (nthreads, lastdb); |
2464 | |
2465 | /* Create the threads which prune the databases. */ |
2466 | // XXX Ideally this work would be done by some of the worker threads. |
2467 | // XXX But this is problematic since we would need to be able to wake |
2468 | // XXX them up explicitly as well as part of the group handling the |
2469 | // XXX ready-list. This requires an operation where we can wait on |
2470 | // XXX two conditional variables at the same time. This operation |
2471 | // XXX does not exist (yet). |
2472 | for (long int i = 0; i < lastdb; ++i) |
2473 | { |
2474 | /* Initialize the conditional variable. */ |
2475 | if (pthread_cond_init (&dbs[i].prune_cond, &condattr) != 0) |
2476 | { |
2477 | dbg_log (_("could not initialize conditional variable" )); |
2478 | do_exit (1, 0, NULL); |
2479 | } |
2480 | |
2481 | pthread_t th; |
2482 | if (dbs[i].enabled |
2483 | && pthread_create (&th, &attr, nscd_run_prune, (void *) i) != 0) |
2484 | { |
2485 | dbg_log (_("could not start clean-up thread; terminating" )); |
2486 | do_exit (1, 0, NULL); |
2487 | } |
2488 | } |
2489 | |
2490 | pthread_condattr_destroy (&condattr); |
2491 | |
2492 | for (long int i = 0; i < nthreads; ++i) |
2493 | { |
2494 | pthread_t th; |
2495 | if (pthread_create (&th, &attr, nscd_run_worker, NULL) != 0) |
2496 | { |
2497 | if (i == 0) |
2498 | { |
2499 | dbg_log (_("could not start any worker thread; terminating" )); |
2500 | do_exit (1, 0, NULL); |
2501 | } |
2502 | |
2503 | break; |
2504 | } |
2505 | } |
2506 | |
2507 | /* Now it is safe to let the parent know that we're doing fine and it can |
2508 | exit. */ |
2509 | notify_parent (0); |
2510 | |
2511 | /* Determine how much room for descriptors we should initially |
2512 | allocate. This might need to change later if we cap the number |
2513 | with MAXCONN. */ |
2514 | const long int nfds = sysconf (_SC_OPEN_MAX); |
2515 | #define MINCONN 32 |
2516 | #define MAXCONN 16384 |
2517 | if (nfds == -1 || nfds > MAXCONN) |
2518 | nconns = MAXCONN; |
2519 | else if (nfds < MINCONN) |
2520 | nconns = MINCONN; |
2521 | else |
2522 | nconns = nfds; |
2523 | |
2524 | /* We need memory to pass descriptors on to the worker threads. */ |
2525 | fdlist = (struct fdlist *) xcalloc (nconns, sizeof (fdlist[0])); |
2526 | /* Array to keep track when connection was accepted. */ |
2527 | starttime = (time_t *) xcalloc (nconns, sizeof (starttime[0])); |
2528 | |
2529 | /* In the main thread we execute the loop which handles incoming |
2530 | connections. */ |
2531 | #ifdef HAVE_EPOLL |
2532 | int efd = epoll_create (100); |
2533 | if (efd != -1) |
2534 | { |
2535 | main_loop_epoll (efd); |
2536 | close (efd); |
2537 | } |
2538 | #endif |
2539 | |
2540 | main_loop_poll (); |
2541 | } |
2542 | |
2543 | |
2544 | /* Look up the uid, gid, and supplementary groups to run nscd as. When |
2545 | this function is called, we are not listening on the nscd socket yet so |
2546 | we can just use the ordinary lookup functions without causing a lockup */ |
2547 | static void |
2548 | begin_drop_privileges (void) |
2549 | { |
2550 | struct passwd *pwd = getpwnam (server_user); |
2551 | |
2552 | if (pwd == NULL) |
2553 | { |
2554 | dbg_log (_("Failed to run nscd as user '%s'" ), server_user); |
2555 | do_exit (EXIT_FAILURE, 0, |
2556 | _("Failed to run nscd as user '%s'" ), server_user); |
2557 | } |
2558 | |
2559 | server_uid = pwd->pw_uid; |
2560 | server_gid = pwd->pw_gid; |
2561 | |
2562 | /* Save the old UID/GID if we have to change back. */ |
2563 | if (paranoia) |
2564 | { |
2565 | old_uid = getuid (); |
2566 | old_gid = getgid (); |
2567 | } |
2568 | |
2569 | if (getgrouplist (server_user, server_gid, NULL, &server_ngroups) == 0) |
2570 | { |
2571 | /* This really must never happen. */ |
2572 | dbg_log (_("Failed to run nscd as user '%s'" ), server_user); |
2573 | do_exit (EXIT_FAILURE, errno, |
2574 | _("initial getgrouplist failed" )); |
2575 | } |
2576 | |
2577 | server_groups = (gid_t *) xmalloc (server_ngroups * sizeof (gid_t)); |
2578 | |
2579 | if (getgrouplist (server_user, server_gid, server_groups, &server_ngroups) |
2580 | == -1) |
2581 | { |
2582 | dbg_log (_("Failed to run nscd as user '%s'" ), server_user); |
2583 | do_exit (EXIT_FAILURE, errno, _("getgrouplist failed" )); |
2584 | } |
2585 | } |
2586 | |
2587 | |
2588 | /* Call setgroups(), setgid(), and setuid() to drop root privileges and |
2589 | run nscd as the user specified in the configuration file. */ |
2590 | static void |
2591 | finish_drop_privileges (void) |
2592 | { |
2593 | #if defined HAVE_LIBAUDIT && defined HAVE_LIBCAP |
2594 | /* We need to preserve the capabilities to connect to the audit daemon. */ |
2595 | cap_t new_caps = preserve_capabilities (); |
2596 | #endif |
2597 | |
2598 | if (setgroups (server_ngroups, server_groups) == -1) |
2599 | { |
2600 | dbg_log (_("Failed to run nscd as user '%s'" ), server_user); |
2601 | do_exit (EXIT_FAILURE, errno, _("setgroups failed" )); |
2602 | } |
2603 | |
2604 | int res; |
2605 | if (paranoia) |
2606 | res = setresgid (server_gid, server_gid, old_gid); |
2607 | else |
2608 | res = setgid (server_gid); |
2609 | if (res == -1) |
2610 | { |
2611 | dbg_log (_("Failed to run nscd as user '%s'" ), server_user); |
2612 | do_exit (4, errno, "setgid" ); |
2613 | } |
2614 | |
2615 | if (paranoia) |
2616 | res = setresuid (server_uid, server_uid, old_uid); |
2617 | else |
2618 | res = setuid (server_uid); |
2619 | if (res == -1) |
2620 | { |
2621 | dbg_log (_("Failed to run nscd as user '%s'" ), server_user); |
2622 | do_exit (4, errno, "setuid" ); |
2623 | } |
2624 | |
2625 | #if defined HAVE_LIBAUDIT && defined HAVE_LIBCAP |
2626 | /* Remove the temporary capabilities. */ |
2627 | install_real_capabilities (new_caps); |
2628 | #endif |
2629 | } |
2630 | |