1 /* $NetBSD: statd.c,v 1.34 2019/12/02 19:23:53 christos Exp $ */
2
3 /*
4 * Copyright (c) 1995
5 * A.R. Gordon (andrew.gordon@net-tel.co.uk). All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed for the FreeBSD project
18 * 4. Neither the name of the author nor the names of any co-contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY ANDREW GORDON AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 */
35
36 #include <sys/cdefs.h>
37 #ifndef lint
38 __RCSID("$NetBSD: statd.c,v 1.34 2019/12/02 19:23:53 christos Exp $");
39 #endif
40
41 /* main() function for status monitor daemon. Some of the code in this */
42 /* file was generated by running rpcgen /usr/include/rpcsvc/sm_inter.x */
43 /* The actual program logic is in the file procs.c */
44
45 #include <sys/param.h>
46 #include <sys/wait.h>
47
48 #include <err.h>
49 #include <ctype.h>
50 #include <errno.h>
51 #include <fcntl.h>
52 #include <signal.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <syslog.h>
57 #include <unistd.h>
58 #include <util.h>
59 #include <db.h>
60 #include <netconfig.h>
61
62 #include <rpc/rpc.h>
63
64 #include "statd.h"
65
66 struct sigaction sa;
67 int debug = 0; /* Controls syslog() for debug msgs */
68 extern int _rpcsvcdirty;
69 static DB *db; /* Database file */
70
71 Header status_info;
72
73 static char undefdata[] = "\0\1\2\3\4\5\6\7";
74 static DBT undefkey = {
75 undefdata,
76 sizeof(undefdata)
77 };
78
79
80 /* statd.c */
81 static int walk_one(int (*fun )(DBT *, HostInfo *, void *), DBT *, DBT *, void *);
82 static int walk_db(int (*fun )(DBT *, HostInfo *, void *), void *);
83 static int reset_host(DBT *, HostInfo *, void *);
84 static int check_work(DBT *, HostInfo *, void *);
85 static int unmon_host(DBT *, HostInfo *, void *);
86 static int notify_one(DBT *, HostInfo *, void *);
87 static void init_file(const char *);
88 static int notify_one_host(const char *);
89 static void die(int) __dead;
90
91 int
main(int argc,char * argv[])92 main(int argc, char *argv[])
93 {
94 int ch;
95 struct sigaction nsa;
96 int maxrec = RPC_MAXDATASIZE;
97
98 while ((ch = getopt(argc, argv, "d")) != (-1)) {
99 switch (ch) {
100 case 'd':
101 debug = 1;
102 break;
103 default:
104 case '?':
105 (void)fprintf(stderr, "usage: %s [-d]\n",
106 getprogname());
107 exit(1);
108 /* NOTREACHED */
109 }
110 }
111 (void)rpcb_unset(SM_PROG, SM_VERS, NULL);
112
113 rpc_control(RPC_SVC_CONNMAXREC_SET, &maxrec);
114
115 if (!svc_create(sm_prog_1, SM_PROG, SM_VERS, "udp")) {
116 errx(EXIT_FAILURE, "cannot create udp service.");
117 /* NOTREACHED */
118 }
119 if (!svc_create(sm_prog_1, SM_PROG, SM_VERS, "tcp")) {
120 errx(EXIT_FAILURE, "cannot create udp service.");
121 /* NOTREACHED */
122 }
123
124 init_file("/var/db/statd.status");
125
126 /*
127 * Note that it is NOT sensible to run this program from inetd - the
128 * protocol assumes that it will run immediately at boot time.
129 */
130 if (!debug)
131 daemon(0, 0);
132
133 sigemptyset(&nsa.sa_mask);
134 nsa.sa_flags = SA_NOCLDSTOP|SA_NOCLDWAIT;
135 nsa.sa_handler = SIG_IGN;
136 (void)sigaction(SIGCHLD, &nsa, NULL);
137
138 pidfile(NULL);
139 openlog("rpc.statd", 0, LOG_DAEMON);
140 if (debug)
141 syslog(LOG_INFO, "Starting - debug enabled");
142 else
143 syslog(LOG_INFO, "Starting");
144
145 sa.sa_handler = die;
146 sa.sa_flags = 0;
147 sigemptyset(&sa.sa_mask);
148 (void)sigaction(SIGTERM, &sa, NULL);
149 (void)sigaction(SIGQUIT, &sa, NULL);
150 (void)sigaction(SIGHUP, &sa, NULL);
151 (void)sigaction(SIGINT, &sa, NULL);
152
153 sa.sa_handler = SIG_IGN;
154 sa.sa_flags = SA_RESTART;
155 sigemptyset(&sa.sa_mask);
156 sigaddset(&sa.sa_mask, SIGALRM);
157
158 /* Initialisation now complete - start operating */
159
160 /* Notify hosts that need it */
161 notify_handler(0);
162
163 while (1)
164 svc_run(); /* Should never return */
165 die(0);
166 }
167
168 /* notify_handler ---------------------------------------------------------- */
169 /*
170 * Purpose: Catch SIGALRM and collect process status
171 * Returns: Nothing.
172 * Notes: No special action required, other than to collect the
173 * process status and hence allow the child to die:
174 * we only use child processes for asynchronous transmission
175 * of SM_NOTIFY to other systems, so it is normal for the
176 * children to exit when they have done their work.
177 */
178 void
notify_handler(int sig)179 notify_handler(int sig)
180 {
181 time_t now;
182
183 NO_ALARM;
184 sa.sa_handler = SIG_IGN;
185 (void)sigaction(SIGALRM, &sa, NULL);
186
187 now = time(NULL);
188
189 (void) walk_db(notify_one, &now);
190
191 if (walk_db(check_work, &now) == 0) {
192 /*
193 * No more work to be done.
194 */
195 CLR_ALARM;
196 return;
197 }
198 sync_file();
199 ALARM;
200 alarm(5);
201 }
202
203 /* sync_file --------------------------------------------------------------- */
204 /*
205 * Purpose: Packaged call of msync() to flush changes to mmap()ed file
206 * Returns: Nothing. Errors to syslog.
207 */
208 void
sync_file()209 sync_file()
210 {
211 DBT data;
212
213 data.data = &status_info;
214 data.size = sizeof(status_info);
215 switch ((*db->put)(db, &undefkey, &data, 0)) {
216 case 0:
217 return;
218 case -1:
219 goto bad;
220 default:
221 abort();
222 }
223 if ((*db->sync)(db, 0) == -1) {
224 bad:
225 syslog(LOG_ERR, "database corrupted %m");
226 die(1);
227 }
228 }
229
230 /* change_host -------------------------------------------------------------- */
231 /*
232 * Purpose: Update/Create an entry for host
233 * Returns: Nothing
234 * Notes:
235 *
236 */
237 void
change_host(char * hostnamep,HostInfo * hp)238 change_host(char *hostnamep, HostInfo *hp)
239 {
240 DBT key, data;
241 char *ptr;
242 char hostname[MAXHOSTNAMELEN + 1];
243 HostInfo h;
244
245 strncpy(hostname, hostnamep, MAXHOSTNAMELEN + 1);
246 h = *hp;
247
248 for (ptr = hostname; *ptr; ptr++)
249 if (isupper((unsigned char) *ptr))
250 *ptr = tolower((unsigned char) *ptr);
251
252 key.data = hostname;
253 key.size = ptr - hostname + 1;
254 data.data = &h;
255 data.size = sizeof(h);
256
257 switch ((*db->put)(db, &key, &data, 0)) {
258 case -1:
259 syslog(LOG_ERR, "database corrupted %m");
260 die(1);
261 case 0:
262 return;
263 default:
264 abort();
265 }
266 }
267
268
269 /* find_host -------------------------------------------------------------- */
270 /*
271 * Purpose: Find the entry in the status file for a given host
272 * Returns: Copy of entry in hd, or NULL
273 * Notes:
274 *
275 */
276 HostInfo *
find_host(char * hostname,HostInfo * hp)277 find_host(char *hostname, HostInfo *hp)
278 {
279 DBT key, data;
280 char *ptr;
281
282 for (ptr = hostname; *ptr; ptr++)
283 if (isupper((unsigned char) *ptr))
284 *ptr = tolower((unsigned char) *ptr);
285
286 key.data = hostname;
287 key.size = ptr - hostname + 1;
288 switch ((*db->get)(db, &key, &data, 0)) {
289 case 0:
290 if (data.size != sizeof(*hp))
291 goto bad;
292 return memcpy(hp, data.data, sizeof(*hp));
293 case 1:
294 return NULL;
295 case -1:
296 goto bad;
297 default:
298 abort();
299 }
300
301 bad:
302 syslog(LOG_ERR, "Database corrupted %m");
303 return NULL;
304 }
305
306 /* walk_one ------------------------------------------------------------- */
307 /*
308 * Purpose: Call the given function if the element is valid
309 * Returns: Nothing - exits on error
310 * Notes:
311 */
312 static int
walk_one(int (* fun)(DBT *,HostInfo *,void *),DBT * key,DBT * data,void * ptr)313 walk_one(int (*fun)(DBT *, HostInfo *, void *), DBT *key, DBT *data, void *ptr)
314 {
315 HostInfo h;
316 if (key->size == undefkey.size &&
317 memcmp(key->data, undefkey.data, key->size) == 0)
318 return 0;
319 if (data->size != sizeof(HostInfo)) {
320 syslog(LOG_ERR, "Bad data in database");
321 die(1);
322 }
323 memcpy(&h, data->data, sizeof(h));
324 return (*fun)(key, &h, ptr);
325 }
326
327 /* walk_db -------------------------------------------------------------- */
328 /*
329 * Purpose: Iterate over all elements calling the given function
330 * Returns: -1 if function failed, 0 on success
331 * Notes:
332 */
333 static int
walk_db(int (* fun)(DBT *,HostInfo *,void *),void * ptr)334 walk_db(int (*fun)(DBT *, HostInfo *, void *), void *ptr)
335 {
336 DBT key, data;
337
338 switch ((*db->seq)(db, &key, &data, R_FIRST)) {
339 case -1:
340 goto bad;
341 case 1:
342 /* We should have at least the magic entry at this point */
343 abort();
344 case 0:
345 if (walk_one(fun, &key, &data, ptr) == -1)
346 return -1;
347 break;
348 default:
349 abort();
350 }
351
352
353 for (;;)
354 switch ((*db->seq)(db, &key, &data, R_NEXT)) {
355 case -1:
356 goto bad;
357 case 0:
358 if (walk_one(fun, &key, &data, ptr) == -1)
359 return -1;
360 break;
361 case 1:
362 return 0;
363 default:
364 abort();
365 }
366 bad:
367 syslog(LOG_ERR, "Corrupted database %m");
368 die(1);
369 }
370
371 /* reset_host ------------------------------------------------------------ */
372 /*
373 * Purpose: Clean up existing hosts in file.
374 * Returns: Always success 0.
375 * Notes: Clean-up of existing file - monitored hosts will have a
376 * pointer to a list of clients, which refers to memory in
377 * the previous incarnation of the program and so are
378 * meaningless now. These pointers are zeroed and the fact
379 * that the host was previously monitored is recorded by
380 * setting the notifyReqd flag, which will in due course
381 * cause a SM_NOTIFY to be sent.
382 *
383 * Note that if we crash twice in quick succession, some hosts
384 * may already have notifyReqd set, where we didn't manage to
385 * notify them before the second crash occurred.
386 */
387 static int
reset_host(DBT * key,HostInfo * hi,void * ptr)388 reset_host(DBT *key, HostInfo *hi, void *ptr)
389 {
390
391 if (hi->monList) {
392 hi->notifyReqd = *(time_t *) ptr;
393 hi->attempts = 0;
394 hi->monList = NULL;
395 change_host((char *)key->data, hi);
396 }
397 return 0;
398 }
399
400 /* check_work ------------------------------------------------------------ */
401 /*
402 * Purpose: Check if there is work to be done.
403 * Returns: 0 if there is no work to be done -1 if there is.
404 * Notes:
405 */
406 static int
check_work(DBT * key,HostInfo * hi,void * ptr)407 check_work(DBT *key, HostInfo *hi, void *ptr)
408 {
409 return hi->notifyReqd ? -1 : 0;
410 }
411
412 /* unmon_host ------------------------------------------------------------ */
413 /*
414 * Purpose: Unmonitor a host
415 * Returns: 0
416 * Notes:
417 */
418 static int
unmon_host(DBT * key,HostInfo * hi,void * ptr)419 unmon_host(DBT *key, HostInfo *hi, void *ptr)
420 {
421 char *name = key->data;
422
423 if (do_unmon(name, hi, ptr))
424 change_host(name, hi);
425 return 0;
426 }
427
428 /* notify_one ------------------------------------------------------------ */
429 /*
430 * Purpose: Notify one host.
431 * Returns: 0 if success -1 on failure
432 * Notes:
433 */
434 static int
notify_one(DBT * key,HostInfo * hi,void * ptr)435 notify_one(DBT *key, HostInfo *hi, void *ptr)
436 {
437 time_t now = *(time_t *) ptr;
438 char *name = key->data;
439 int error;
440
441 if (hi->notifyReqd == 0 || hi->notifyReqd > now)
442 return 0;
443
444 /*
445 * If one of the initial attempts fails, we wait
446 * for a while and have another go. This is necessary
447 * because when we have crashed, (eg. a power outage)
448 * it is quite possible that we won't be able to
449 * contact all monitored hosts immediately on restart,
450 * either because they crashed too and take longer
451 * to come up (in which case the notification isn't
452 * really required), or more importantly if some
453 * router etc. needed to reach the monitored host
454 * has not come back up yet. In this case, we will
455 * be a bit late in re-establishing locks (after the
456 * grace period) but that is the best we can do. We
457 * try 10 times at 5 sec intervals, 10 more times at
458 * 1 minute intervals, then 24 more times at hourly
459 * intervals, finally giving up altogether if the
460 * host hasn't come back to life after 24 hours.
461 */
462 if (notify_one_host(name) || hi->attempts++ >= 44) {
463 error = 0;
464 hi->notifyReqd = 0;
465 hi->attempts = 0;
466 } else {
467 error = -1;
468 if (hi->attempts < 10)
469 hi->notifyReqd += 5;
470 else if (hi->attempts < 20)
471 hi->notifyReqd += 60;
472 else
473 hi->notifyReqd += 60 * 60;
474 }
475 change_host(name, hi);
476 return error;
477 }
478
479 /* init_file -------------------------------------------------------------- */
480 /*
481 * Purpose: Open file, create if necessary, initialise it.
482 * Returns: Nothing - exits on error
483 * Notes: Called before process becomes daemon, hence logs to
484 * stderr rather than syslog.
485 * Opens the file, then mmap()s it for ease of access.
486 * Also performs initial clean-up of the file, zeroing
487 * monitor list pointers, setting the notifyReqd flag in
488 * all hosts that had a monitor list, and incrementing
489 * the state number to the next even value.
490 */
491 static void
init_file(const char * filename)492 init_file(const char *filename)
493 {
494 DBT data;
495
496 db = dbopen(filename, O_RDWR|O_CREAT|O_NDELAY|O_EXLOCK, 0644, DB_HASH,
497 NULL);
498 if (db == NULL)
499 err(EXIT_FAILURE, "Cannot open `%s'", filename);
500
501 switch ((*db->get)(db, &undefkey, &data, 0)) {
502 case 1:
503 /* New database */
504 (void)memset(&status_info, 0, sizeof(status_info));
505 sync_file();
506 return;
507
508 case -1:
509 err(EXIT_FAILURE, "error accessing database (%s)", strerror(errno));
510 case 0:
511 /* Existing database */
512 if (data.size != sizeof(status_info))
513 errx(EXIT_FAILURE, "database corrupted %lu != %lu",
514 (u_long)data.size, (u_long)sizeof(status_info));
515 memcpy(&status_info, data.data, data.size);
516 break;
517 default:
518 abort();
519 }
520
521 reset_database();
522 return;
523 }
524
525 /* reset_database --------------------------------------------------------- */
526 /*
527 * Purpose: Clears the statd database
528 * Returns: Nothing
529 * Notes: If this is not called on reset, it will leak memory.
530 */
531 void
reset_database()532 reset_database()
533 {
534 time_t now = time(NULL);
535 walk_db(reset_host, &now);
536
537 /* Select the next higher even number for the state counter */
538 status_info.ourState =
539 (status_info.ourState + 2) & 0xfffffffe;
540 status_info.ourState++; /* XXX - ??? */
541 sync_file();
542 }
543
544 /* unmon_hosts --------------------------------------------------------- */
545 /*
546 * Purpose: Unmonitor all the hosts
547 * Returns: Nothing
548 * Notes:
549 */
550 void
unmon_hosts()551 unmon_hosts()
552 {
553 time_t now = time(NULL);
554 walk_db(unmon_host, &now);
555 sync_file();
556 }
557
558 static int
notify_one_host(const char * hostname)559 notify_one_host(const char *hostname)
560 {
561 struct timeval timeout = {20, 0}; /* 20 secs timeout */
562 CLIENT *cli;
563 char dummy;
564 stat_chge arg;
565 char our_hostname[MAXHOSTNAMELEN + 1];
566
567 gethostname(our_hostname, sizeof(our_hostname));
568 our_hostname[sizeof(our_hostname) - 1] = '\0';
569 arg.mon_name = our_hostname;
570 arg.state = status_info.ourState;
571
572 if (debug)
573 syslog(LOG_DEBUG, "Sending SM_NOTIFY to host %s from %s",
574 hostname, our_hostname);
575
576 cli = clnt_create(hostname, SM_PROG, SM_VERS, "udp");
577 if (!cli) {
578 syslog(LOG_ERR, "Failed to contact host %s%s", hostname,
579 clnt_spcreateerror(""));
580 return (FALSE);
581 }
582 if (clnt_call(cli, SM_NOTIFY, xdr_stat_chge, &arg, xdr_void,
583 &dummy, timeout) != RPC_SUCCESS) {
584 syslog(LOG_ERR, "Failed to contact rpc.statd at host %s",
585 hostname);
586 clnt_destroy(cli);
587 return (FALSE);
588 }
589 clnt_destroy(cli);
590 return (TRUE);
591 }
592
593
594 static void
die(int n)595 die(int n)
596 {
597 (*db->close)(db);
598 exit(n);
599 }
600