xref: /openbsd/usr.sbin/rpc.lockd/lockd_lock.c (revision 274d7c50)
1 /*	$OpenBSD: lockd_lock.c,v 1.10 2019/06/28 13:32:50 deraadt Exp $	*/
2 
3 /*
4  * Copyright (c) 2000 Manuel Bouyer.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  */
28 
29 #include <sys/socket.h>
30 #include <sys/stat.h>
31 #include <sys/mount.h>
32 #include <sys/wait.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <unistd.h>
36 #include <fcntl.h>
37 #include <inttypes.h>
38 #include <syslog.h>
39 #include <errno.h>
40 #include <string.h>
41 #include <signal.h>
42 #include <rpc/rpc.h>
43 #include <rpcsvc/sm_inter.h>
44 #include <rpcsvc/nlm_prot.h>
45 #include "lockd_lock.h"
46 #include "lockd.h"
47 
48 /* A set of utilities for managing file locking */
49 LIST_HEAD(lcklst_head, file_lock);
50 struct lcklst_head lcklst_head = LIST_HEAD_INITIALIZER(lcklst_head);
51 
52 #define	FHANDLE_SIZE_MAX	1024	/* arbitrary big enough value */
53 typedef struct {
54 	size_t fhsize;
55 	char *fhdata;
56 } nfs_fhandle_t;
57 
58 static int
59 fhcmp(const nfs_fhandle_t *fh1, const nfs_fhandle_t *fh2)
60 {
61 	return memcmp(fh1->fhdata, fh2->fhdata, sizeof(fhandle_t));
62 }
63 
64 static int
65 fhconv(nfs_fhandle_t *fh, const netobj *rfh)
66 {
67 	size_t sz;
68 
69 	sz = rfh->n_len;
70 	if (sz > FHANDLE_SIZE_MAX) {
71 		syslog(LOG_DEBUG,
72 		    "received fhandle size %zd, max supported size %d",
73 		    sz, FHANDLE_SIZE_MAX);
74 		errno = EINVAL;
75 		return -1;
76 	}
77 	fh->fhdata = malloc(sz);
78 	if (fh->fhdata == NULL) {
79 		return -1;
80 	}
81 	fh->fhsize = sz;
82 	memcpy(fh->fhdata, rfh->n_bytes, sz);
83 	return 0;
84 }
85 
86 static void
87 fhfree(nfs_fhandle_t *fh)
88 {
89 
90 	free(fh->fhdata);
91 }
92 
93 /* struct describing a lock */
94 struct file_lock {
95 	LIST_ENTRY(file_lock) lcklst;
96 	nfs_fhandle_t filehandle; /* NFS filehandle */
97 	struct sockaddr_in *addr;
98 	struct nlm4_holder client; /* lock holder */
99 	netobj client_cookie; /* cookie sent by the client */
100 	char client_name[128];
101 	int nsm_status; /* status from the remote lock manager */
102 	int status; /* lock status, see below */
103 	int flags; /* lock flags, see lockd_lock.h */
104 	pid_t locker; /* pid of the child process trying to get the lock */
105 	int fd;	/* file descriptor for this lock */
106 };
107 
108 /* lock status */
109 #define LKST_LOCKED	1 /* lock is locked */
110 #define LKST_WAITING	2 /* file is already locked by another host */
111 #define LKST_PROCESSING	3 /* child is trying to acquire the lock */
112 #define LKST_DYING	4 /* must die when we get news from the child */
113 
114 static struct file_lock *lalloc(void);
115 void lfree(struct file_lock *);
116 enum nlm_stats do_lock(struct file_lock *, int);
117 enum nlm_stats do_unlock(struct file_lock *);
118 void send_granted(struct file_lock *, int);
119 void siglock(void);
120 void sigunlock(void);
121 
122 /* list of hosts we monitor */
123 LIST_HEAD(hostlst_head, host);
124 struct hostlst_head hostlst_head = LIST_HEAD_INITIALIZER(hostlst_head);
125 
126 /* struct describing a lock */
127 struct host {
128 	LIST_ENTRY(host) hostlst;
129 	char name[SM_MAXSTRLEN+1];
130 	int refcnt;
131 };
132 
133 void do_mon(const char *);
134 
135 #define	LL_FH	0x01
136 #define	LL_NAME	0x02
137 #define	LL_SVID	0x04
138 
139 static struct file_lock *lock_lookup(struct file_lock *, int);
140 
141 /*
142  * lock_lookup: lookup a matching lock.
143  * called with siglock held.
144  */
145 static struct file_lock *
146 lock_lookup(struct file_lock *newfl, int flags)
147 {
148 	struct file_lock *fl;
149 
150 	LIST_FOREACH(fl, &lcklst_head, lcklst) {
151 		if ((flags & LL_SVID) != 0 &&
152 		    newfl->client.svid != fl->client.svid)
153 			continue;
154 		if ((flags & LL_NAME) != 0 &&
155 		    strcmp(newfl->client_name, fl->client_name) != 0)
156 			continue;
157 		if ((flags & LL_FH) != 0 &&
158 		    fhcmp(&newfl->filehandle, &fl->filehandle) != 0)
159 			continue;
160 		/* found */
161 		break;
162 	}
163 
164 	return fl;
165 }
166 
167 /*
168  * testlock(): inform the caller if the requested lock would be granted or not
169  * returns NULL if lock would granted, or pointer to the current nlm4_holder
170  * otherwise.
171  */
172 
173 struct nlm4_holder *
174 /*ARGSUSED*/
175 testlock(struct nlm4_lock *lock, int flags)
176 {
177 	struct file_lock *fl;
178 	nfs_fhandle_t filehandle;
179 
180 	/* convert lock to a local filehandle */
181 	if (fhconv(&filehandle, &lock->fh)) {
182 		syslog(LOG_NOTICE, "fhconv failed (%m)");
183 		return NULL; /* XXX */
184 	}
185 
186 	siglock();
187 	/* search through the list for lock holder */
188 	LIST_FOREACH(fl, &lcklst_head, lcklst) {
189 		if (fl->status != LKST_LOCKED)
190 			continue;
191 		if (fhcmp(&fl->filehandle, &filehandle) != 0)
192 			continue;
193 		/* got it ! */
194 		syslog(LOG_DEBUG, "test for %s: found lock held by %s",
195 		    lock->caller_name, fl->client_name);
196 		sigunlock();
197 		fhfree(&filehandle);
198 		return (&fl->client);
199 	}
200 	/* not found */
201 	sigunlock();
202 	fhfree(&filehandle);
203 	syslog(LOG_DEBUG, "test for %s: no lock found", lock->caller_name);
204 	return NULL;
205 }
206 
207 /*
208  * getlock: try to acquire the lock.
209  * If file is already locked and we can sleep, put the lock in the list with
210  * status LKST_WAITING; it'll be processed later.
211  * Otherwise try to lock. If we're allowed to block, fork a child which
212  * will do the blocking lock.
213  */
214 enum nlm_stats
215 getlock(nlm4_lockargs * lckarg, struct svc_req *rqstp, int flags)
216 {
217 	struct file_lock *fl, *newfl;
218 	enum nlm_stats retval;
219 	struct sockaddr_in *addr;
220 
221 	if (grace_expired == 0 && lckarg->reclaim == 0)
222 		return (flags & LOCK_V4) ?
223 		    nlm4_denied_grace_period : nlm_denied_grace_period;
224 
225 	/* allocate new file_lock for this request */
226 	newfl = lalloc();
227 	if (newfl == NULL) {
228 		syslog(LOG_NOTICE, "malloc failed (%m)");
229 		/* failed */
230 		return (flags & LOCK_V4) ?
231 		    nlm4_denied_nolock : nlm_denied_nolocks;
232 	}
233 	if (fhconv(&newfl->filehandle, &lckarg->alock.fh)) {
234 		syslog(LOG_NOTICE, "fhconv failed (%m)");
235 		lfree(newfl);
236 		/* failed */
237 		return (flags & LOCK_V4) ?
238 		    nlm4_denied_nolock : nlm_denied_nolocks;
239 	}
240 	addr = svc_getcaller(rqstp->rq_xprt);
241 	newfl->addr = malloc(addr->sin_len);
242 	if (newfl->addr == NULL) {
243 		syslog(LOG_NOTICE, "malloc failed (%m)");
244 		lfree(newfl);
245 		/* failed */
246 		return (flags & LOCK_V4) ?
247 		    nlm4_denied_nolock : nlm_denied_nolocks;
248 	}
249 	memcpy(newfl->addr, addr, addr->sin_len);
250 	newfl->client.exclusive = lckarg->exclusive;
251 	newfl->client.svid = lckarg->alock.svid;
252 	newfl->client.oh.n_bytes = malloc(lckarg->alock.oh.n_len);
253 	if (newfl->client.oh.n_bytes == NULL) {
254 		syslog(LOG_NOTICE, "malloc failed (%m)");
255 		lfree(newfl);
256 		return (flags & LOCK_V4) ?
257 		    nlm4_denied_nolock : nlm_denied_nolocks;
258 	}
259 	newfl->client.oh.n_len = lckarg->alock.oh.n_len;
260 	memcpy(newfl->client.oh.n_bytes, lckarg->alock.oh.n_bytes,
261 	    lckarg->alock.oh.n_len);
262 	newfl->client.l_offset = lckarg->alock.l_offset;
263 	newfl->client.l_len = lckarg->alock.l_len;
264 	newfl->client_cookie.n_len = lckarg->cookie.n_len;
265 	newfl->client_cookie.n_bytes = malloc(lckarg->cookie.n_len);
266 	if (newfl->client_cookie.n_bytes == NULL) {
267 		syslog(LOG_NOTICE, "malloc failed (%m)");
268 		lfree(newfl);
269 		return (flags & LOCK_V4) ?
270 		    nlm4_denied_nolock : nlm_denied_nolocks;
271 	}
272 	memcpy(newfl->client_cookie.n_bytes, lckarg->cookie.n_bytes,
273 	    lckarg->cookie.n_len);
274 	strlcpy(newfl->client_name, lckarg->alock.caller_name,
275 	    sizeof(newfl->client_name));
276 	newfl->nsm_status = lckarg->state;
277 	newfl->status = 0;
278 	newfl->flags = flags;
279 	siglock();
280 	/* look for a lock rq from this host for this fh */
281 	fl = lock_lookup(newfl, LL_FH|LL_NAME|LL_SVID);
282 	if (fl) {
283 		/* already locked by this host ??? */
284 		sigunlock();
285 		syslog(LOG_NOTICE, "duplicate lock from %s.%"
286 		    PRIu32,
287 		    newfl->client_name, newfl->client.svid);
288 		lfree(newfl);
289 		switch(fl->status) {
290 		case LKST_LOCKED:
291 			return (flags & LOCK_V4) ?
292 			    nlm4_granted : nlm_granted;
293 		case LKST_WAITING:
294 		case LKST_PROCESSING:
295 			return (flags & LOCK_V4) ?
296 			    nlm4_blocked : nlm_blocked;
297 		case LKST_DYING:
298 			return (flags & LOCK_V4) ?
299 			    nlm4_denied : nlm_denied;
300 		default:
301 			syslog(LOG_NOTICE, "bad status %d",
302 			    fl->status);
303 			return (flags & LOCK_V4) ?
304 			    nlm4_failed : nlm_denied;
305 		}
306 		/* NOTREACHED */
307 	}
308 	fl = lock_lookup(newfl, LL_FH);
309 	if (fl) {
310 		/*
311 		 * We already have a lock for this file.
312 		 * Put this one in waiting state if allowed to block
313 		 */
314 		if (lckarg->block) {
315 			syslog(LOG_DEBUG, "lock from %s.%" PRIu32 ": "
316 			    "already locked, waiting",
317 			    lckarg->alock.caller_name,
318 			    lckarg->alock.svid);
319 			newfl->status = LKST_WAITING;
320 			LIST_INSERT_HEAD(&lcklst_head, newfl, lcklst);
321 			do_mon(lckarg->alock.caller_name);
322 			sigunlock();
323 			return (flags & LOCK_V4) ?
324 			    nlm4_blocked : nlm_blocked;
325 		} else {
326 			sigunlock();
327 			syslog(LOG_DEBUG, "lock from %s.%" PRIu32 ": "
328 			    "already locked, failed",
329 			    lckarg->alock.caller_name,
330 			    lckarg->alock.svid);
331 			lfree(newfl);
332 			return (flags & LOCK_V4) ?
333 			    nlm4_denied : nlm_denied;
334 		}
335 		/* NOTREACHED */
336 	}
337 
338 	/* no entry for this file yet; add to list */
339 	LIST_INSERT_HEAD(&lcklst_head, newfl, lcklst);
340 	/* do the lock */
341 	retval = do_lock(newfl, lckarg->block);
342 	switch (retval) {
343 	case nlm4_granted:
344 	/* case nlm_granted: is the same as nlm4_granted */
345 	case nlm4_blocked:
346 	/* case nlm_blocked: is the same as nlm4_blocked */
347 		do_mon(lckarg->alock.caller_name);
348 		break;
349 	default:
350 		lfree(newfl);
351 		break;
352 	}
353 	sigunlock();
354 	return retval;
355 }
356 
357 /* unlock a filehandle */
358 enum nlm_stats
359 unlock(nlm4_lock *lck, int flags)
360 {
361 	struct file_lock *fl;
362 	nfs_fhandle_t filehandle;
363 	int err = (flags & LOCK_V4) ? nlm4_granted : nlm_granted;
364 
365 	if (fhconv(&filehandle, &lck->fh)) {
366 		syslog(LOG_NOTICE, "fhconv failed (%m)");
367 		return (flags & LOCK_V4) ? nlm4_denied : nlm_denied;
368 	}
369 	siglock();
370 	LIST_FOREACH(fl, &lcklst_head, lcklst) {
371 		if (strcmp(fl->client_name, lck->caller_name) ||
372 		    fhcmp(&filehandle, &fl->filehandle) != 0 ||
373 		    fl->client.oh.n_len != lck->oh.n_len ||
374 		    memcmp(fl->client.oh.n_bytes, lck->oh.n_bytes,
375 			fl->client.oh.n_len) != 0 ||
376 		    fl->client.svid != lck->svid)
377 			continue;
378 		/* Got it, unlock and remove from the queue */
379 		syslog(LOG_DEBUG, "unlock from %s.%" PRIu32 ": found struct, "
380 		    "status %d", lck->caller_name, lck->svid, fl->status);
381 		switch (fl->status) {
382 		case LKST_LOCKED:
383 			err = do_unlock(fl);
384 			break;
385 		case LKST_WAITING:
386 			/* remove from the list */
387 			LIST_REMOVE(fl, lcklst);
388 			lfree(fl);
389 			break;
390 		case LKST_PROCESSING:
391 			/*
392 			 * being handled by a child; will clean up
393 			 * when the child exits
394 			 */
395 			fl->status = LKST_DYING;
396 			break;
397 		case LKST_DYING:
398 			/* nothing to do */
399 			break;
400 		default:
401 			syslog(LOG_NOTICE, "unknow status %d for %s",
402 			    fl->status, fl->client_name);
403 		}
404 		sigunlock();
405 		fhfree(&filehandle);
406 		return err;
407 	}
408 	sigunlock();
409 	/* didn't find a matching entry; log anyway */
410 	syslog(LOG_NOTICE, "no matching entry for %s",
411 	    lck->caller_name);
412 	fhfree(&filehandle);
413 	return (flags & LOCK_V4) ? nlm4_granted : nlm_granted;
414 }
415 
416 static struct file_lock *
417 lalloc(void)
418 {
419 	return calloc(1, sizeof(struct file_lock));
420 }
421 
422 void
423 lfree(struct file_lock *fl)
424 {
425 	free(fl->addr);
426 	free(fl->client.oh.n_bytes);
427 	free(fl->client_cookie.n_bytes);
428 	fhfree(&fl->filehandle);
429 	free(fl);
430 }
431 
432 void
433 /*ARGSUSED*/
434 sigchild_handler(int sig)
435 {
436 	int sstatus;
437 	pid_t pid;
438 	struct file_lock *fl;
439 
440 	for (;;) {
441 		pid = wait4(-1, &sstatus, WNOHANG, NULL);
442 		if (pid == -1) {
443 			if (errno != ECHILD)
444 				syslog(LOG_NOTICE, "wait failed (%m)");
445 			else
446 				syslog(LOG_DEBUG, "wait failed (%m)");
447 			return;
448 		}
449 		if (pid == 0) {
450 			/* no more child to handle yet */
451 			return;
452 		}
453 		/*
454 		 * if we're here we have a child that exited
455 		 * Find the associated file_lock.
456 		 */
457 		LIST_FOREACH(fl, &lcklst_head, lcklst) {
458 			if (pid == fl->locker)
459 				break;
460 		}
461 		if (fl == NULL) {
462 			syslog(LOG_NOTICE, "unknown child %d", pid);
463 		} else {
464 			/* protect from pid reusing. */
465 			fl->locker = 0;
466 			if (!WIFEXITED(sstatus) || WEXITSTATUS(sstatus) != 0) {
467 				syslog(LOG_NOTICE, "child %d failed", pid);
468 				/*
469 				 * can't do much here; we can't reply
470 				 * anything but OK for blocked locks
471 				 * Eventually the client will time out
472 				 * and retry.
473 				 */
474 				do_unlock(fl);
475 				return;
476 			}
477 
478 			/* check lock status */
479 			syslog(LOG_DEBUG, "processing child %d, status %d",
480 			    pid, fl->status);
481 			switch(fl->status) {
482 			case LKST_PROCESSING:
483 				fl->status = LKST_LOCKED;
484 				send_granted(fl, (fl->flags & LOCK_V4) ?
485 				    nlm4_granted : nlm_granted);
486 				break;
487 			case LKST_DYING:
488 				do_unlock(fl);
489 				break;
490 			default:
491 				syslog(LOG_NOTICE, "bad lock status (%d) for"
492 				   " child %d", fl->status, pid);
493 			}
494 		}
495 	}
496 }
497 
498 /*
499  *
500  * try to acquire the lock described by fl. Eventually fork a child to do a
501  * blocking lock if allowed and required.
502  */
503 
504 enum nlm_stats
505 do_lock(struct file_lock *fl, int block)
506 {
507 	int lflags, error;
508 	struct stat st;
509 
510 	fl->fd = fhopen((fhandle_t *)fl->filehandle.fhdata, O_RDWR);
511 	if (fl->fd == -1) {
512 		switch (errno) {
513 		case ESTALE:
514 			error = nlm4_stale_fh;
515 			break;
516 		case EROFS:
517 			error = nlm4_rofs;
518 			break;
519 		default:
520 			error = nlm4_failed;
521 		}
522 		if ((fl->flags & LOCK_V4) == 0)
523 			error = nlm_denied;
524 		syslog(LOG_NOTICE, "fhopen failed (from %s) (%m)",
525 		    fl->client_name);
526 		LIST_REMOVE(fl, lcklst);
527 		return error;
528 	}
529 	if (fstat(fl->fd, &st) == -1) {
530 		syslog(LOG_NOTICE, "fstat failed (from %s) (%m)",
531 		    fl->client_name);
532 	}
533 	syslog(LOG_DEBUG, "lock from %s.%" PRIu32 " for file%s%s: "
534 	    "dev %u ino %llu (uid %d), flags %d",
535 	    fl->client_name, fl->client.svid,
536 	    fl->client.exclusive ? " (exclusive)":"", block ? " (block)":"",
537 	    st.st_dev, (unsigned long long)st.st_ino, st.st_uid, fl->flags);
538 	lflags = LOCK_NB;
539 	if (fl->client.exclusive == 0)
540 		lflags |= LOCK_SH;
541 	else
542 		lflags |= LOCK_EX;
543 	error = flock(fl->fd, lflags);
544 	if (error != 0 && errno == EAGAIN && block) {
545 		switch (fl->locker = fork()) {
546 		case -1: /* fork failed */
547 			syslog(LOG_NOTICE, "fork failed (%m)");
548 			LIST_REMOVE(fl, lcklst);
549 			close(fl->fd);
550 			return (fl->flags & LOCK_V4) ?
551 			    nlm4_denied_nolock : nlm_denied_nolocks;
552 		case 0:
553 			/*
554 			 * Attempt a blocking lock. Will have to call
555 			 * NLM_GRANTED later.
556 			 */
557 			setproctitle("%s.%" PRIu32,
558 			    fl->client_name, fl->client.svid);
559 			lflags &= ~LOCK_NB;
560 			if(flock(fl->fd, lflags) != 0) {
561 				syslog(LOG_NOTICE, "flock failed (%m)");
562 				_exit(1);
563 			}
564 			/* lock granted */
565 			_exit(0);
566 			/*NOTREACHED*/
567 		default:
568 			syslog(LOG_DEBUG, "lock request from %s.%" PRIu32 ": "
569 			    "forked %d",
570 			    fl->client_name, fl->client.svid, fl->locker);
571 			fl->status = LKST_PROCESSING;
572 			return (fl->flags & LOCK_V4) ?
573 			    nlm4_blocked : nlm_blocked;
574 		}
575 	}
576 	/* non block case */
577 	if (error != 0) {
578 		switch (errno) {
579 		case EAGAIN:
580 			error = nlm4_denied;
581 			break;
582 		case ESTALE:
583 			error = nlm4_stale_fh;
584 			break;
585 		case EROFS:
586 			error = nlm4_rofs;
587 			break;
588 		default:
589 			error = nlm4_failed;
590 		}
591 		if ((fl->flags & LOCK_V4) == 0)
592 			error = nlm_denied;
593 		if (errno != EAGAIN)
594 			syslog(LOG_NOTICE, "flock for %s failed (%m)",
595 			    fl->client_name);
596 		else syslog(LOG_DEBUG, "flock for %s failed (%m)",
597 			    fl->client_name);
598 		LIST_REMOVE(fl, lcklst);
599 		close(fl->fd);
600 		return error;
601 	}
602 	fl->status = LKST_LOCKED;
603 	return (fl->flags & LOCK_V4) ? nlm4_granted : nlm_granted;
604 }
605 
606 void
607 /*ARGSUSED*/
608 send_granted(struct file_lock *fl, int opcode)
609 {
610 	CLIENT *cli;
611 	static char dummy;
612 	struct timeval timeo;
613 	int success;
614 	static struct nlm_res retval;
615 	static struct nlm4_res retval4;
616 
617 	cli = get_client(fl->addr,
618 	    (fl->flags & LOCK_V4) ? NLM_VERS4 : NLM_VERS);
619 	if (cli == NULL) {
620 		syslog(LOG_NOTICE, "failed to get CLIENT for %s.%" PRIu32,
621 		    fl->client_name, fl->client.svid);
622 		/*
623 		 * We fail to notify remote that the lock has been granted.
624 		 * The client will timeout and retry, the lock will be
625 		 * granted at this time.
626 		 */
627 		return;
628 	}
629 	timeo.tv_sec = 0;
630 	timeo.tv_usec = (fl->flags & LOCK_ASYNC) ? 0 : 500000; /* 0.5s */
631 
632 	if (fl->flags & LOCK_V4) {
633 		static nlm4_testargs result;
634 		result.cookie = fl->client_cookie;
635 		result.exclusive = fl->client.exclusive;
636 		result.alock.caller_name = fl->client_name;
637 		result.alock.fh.n_len = fl->filehandle.fhsize;
638 		result.alock.fh.n_bytes = fl->filehandle.fhdata;
639 		result.alock.oh = fl->client.oh;
640 		result.alock.svid = fl->client.svid;
641 		result.alock.l_offset = fl->client.l_offset;
642 		result.alock.l_len = fl->client.l_len;
643 		syslog(LOG_DEBUG, "sending v4 reply%s",
644 		    (fl->flags & LOCK_ASYNC) ? " (async)":"");
645 		if (fl->flags & LOCK_ASYNC) {
646 			success = clnt_call(cli, NLM4_GRANTED_MSG,
647 			    xdr_nlm4_testargs, &result, xdr_void, &dummy, timeo);
648 		} else {
649 			success = clnt_call(cli, NLM4_GRANTED,
650 			    xdr_nlm4_testargs, &result, xdr_nlm4_res,
651 			    &retval4, timeo);
652 		}
653 	} else {
654 		static nlm_testargs result;
655 
656 		result.cookie = fl->client_cookie;
657 		result.exclusive = fl->client.exclusive;
658 		result.alock.caller_name = fl->client_name;
659 		result.alock.fh.n_len = fl->filehandle.fhsize;
660 		result.alock.fh.n_bytes = fl->filehandle.fhdata;
661 		result.alock.oh = fl->client.oh;
662 		result.alock.svid = fl->client.svid;
663 		result.alock.l_offset =
664 		    (unsigned int)fl->client.l_offset;
665 		result.alock.l_len =
666 		    (unsigned int)fl->client.l_len;
667 		syslog(LOG_DEBUG, "sending v1 reply%s",
668 		    (fl->flags & LOCK_ASYNC) ? " (async)":"");
669 		if (fl->flags & LOCK_ASYNC) {
670 			success = clnt_call(cli, NLM_GRANTED_MSG,
671 			    xdr_nlm_testargs, &result, xdr_void, &dummy, timeo);
672 		} else {
673 			success = clnt_call(cli, NLM_GRANTED,
674 			    xdr_nlm_testargs, &result, xdr_nlm_res,
675 			    &retval, timeo);
676 		}
677 	}
678 	if (debug_level > 2)
679 		syslog(LOG_DEBUG, "clnt_call returns %d(%s) for granted",
680 		    success, clnt_sperrno(success));
681 
682 }
683 
684 enum nlm_stats
685 do_unlock(struct file_lock *rfl)
686 {
687 	struct file_lock *fl;
688 	int error;
689 	int lockst;
690 
691 	/* unlock the file: closing is enough ! */
692 	if (close(rfl->fd) == -1) {
693 		if (errno == ESTALE)
694 			error = nlm4_stale_fh;
695 		else
696 			error = nlm4_failed;
697 		if ((rfl->flags & LOCK_V4) == 0)
698 			error = nlm_denied;
699 		syslog(LOG_NOTICE, "close failed (from %s) (%m)",
700 		    rfl->client_name);
701 	} else {
702 		error = (rfl->flags & LOCK_V4) ?
703 		    nlm4_granted : nlm_granted;
704 	}
705 	LIST_REMOVE(rfl, lcklst);
706 
707 	/* process the next LKST_WAITING lock request for this fh */
708 	LIST_FOREACH(fl, &lcklst_head, lcklst) {
709 		if (fl->status != LKST_WAITING ||
710 		    fhcmp(&rfl->filehandle, &fl->filehandle) != 0)
711 			continue;
712 
713 		lockst = do_lock(fl, 1); /* If it's LKST_WAITING we can block */
714 		switch (lockst) {
715 		case nlm4_granted:
716 		/* case nlm_granted: same as nlm4_granted */
717 			send_granted(fl, (fl->flags & LOCK_V4) ?
718 			    nlm4_granted : nlm_granted);
719 			break;
720 		case nlm4_blocked:
721 		/* case nlm_blocked: same as nlm4_blocked */
722 			break;
723 		default:
724 			lfree(fl);
725 			break;
726 		}
727 		break;
728 	}
729 	lfree(rfl);
730 	return error;
731 }
732 
733 void
734 siglock(void)
735 {
736 	sigset_t block;
737 
738 	sigemptyset(&block);
739 	sigaddset(&block, SIGCHLD);
740 
741 	if (sigprocmask(SIG_BLOCK, &block, NULL) == -1) {
742 		syslog(LOG_WARNING, "siglock failed (%m)");
743 	}
744 }
745 
746 void
747 sigunlock(void)
748 {
749 	sigset_t block;
750 
751 	sigemptyset(&block);
752 	sigaddset(&block, SIGCHLD);
753 
754 	if (sigprocmask(SIG_UNBLOCK, &block, NULL) == -1) {
755 		syslog(LOG_WARNING, "sigunlock failed (%m)");
756 	}
757 }
758 
759 /* monitor a host through rpc.statd, and keep a ref count */
760 void
761 do_mon(const char *hostname)
762 {
763 	static char localhost[] = "localhost";
764 	struct host *hp;
765 	struct mon my_mon;
766 	struct sm_stat_res result;
767 	int retval;
768 
769 	LIST_FOREACH(hp, &hostlst_head, hostlst) {
770 		if (strcmp(hostname, hp->name) == 0) {
771 			/* already monitored, just bump refcnt */
772 			hp->refcnt++;
773 			return;
774 		}
775 	}
776 	/* not found, have to create an entry for it */
777 	hp = malloc(sizeof(struct host));
778 	if (hp == NULL) {
779 		syslog(LOG_WARNING, "can't monitor host %s (%m)", hostname);
780 		return;
781 	}
782 	strlcpy(hp->name, hostname, sizeof(hp->name));
783 	hp->refcnt = 1;
784 	syslog(LOG_DEBUG, "monitoring host %s", hostname);
785 	memset(&my_mon, 0, sizeof(my_mon));
786 	my_mon.mon_id.mon_name = hp->name;
787 	my_mon.mon_id.my_id.my_name = localhost;
788 	my_mon.mon_id.my_id.my_prog = NLM_PROG;
789 	my_mon.mon_id.my_id.my_vers = NLM_SM;
790 	my_mon.mon_id.my_id.my_proc = NLM_SM_NOTIFY;
791 	if ((retval = callrpc(localhost, SM_PROG, SM_VERS, SM_MON, xdr_mon,
792 	    (void *)&my_mon, xdr_sm_stat_res, (void *)&result)) != 0) {
793 		syslog(LOG_WARNING, "rpc to statd failed (%s)",
794 		    clnt_sperrno((enum clnt_stat)retval));
795 		free(hp);
796 		return;
797 	}
798 	if (result.res_stat == stat_fail) {
799 		syslog(LOG_WARNING, "statd failed");
800 		free(hp);
801 		return;
802 	}
803 	LIST_INSERT_HEAD(&hostlst_head, hp, hostlst);
804 }
805 
806 void
807 notify(const char *hostname, int state)
808 {
809 	struct file_lock *fl, *next_fl;
810 	int err;
811 	syslog(LOG_DEBUG, "notify from %s, new state %d", hostname, state);
812 	/* search all lock for this host; if status changed, release the lock */
813 	siglock();
814 	for (fl = LIST_FIRST(&lcklst_head); fl != NULL; fl = next_fl) {
815 		next_fl = LIST_NEXT(fl, lcklst);
816 		if (strcmp(hostname, fl->client_name) == 0 &&
817 		    fl->nsm_status != state) {
818 			syslog(LOG_DEBUG, "state %d, nsm_state %d, unlocking",
819 			    fl->status, fl->nsm_status);
820 			switch(fl->status) {
821 			case LKST_LOCKED:
822 				err = do_unlock(fl);
823 				if (err != nlm_granted)
824 					syslog(LOG_DEBUG,
825 					    "notify: unlock failed for %s (%d)",
826 			    		    hostname, err);
827 				break;
828 			case LKST_WAITING:
829 				LIST_REMOVE(fl, lcklst);
830 				lfree(fl);
831 				break;
832 			case LKST_PROCESSING:
833 				fl->status = LKST_DYING;
834 				break;
835 			case LKST_DYING:
836 				break;
837 			default:
838 				syslog(LOG_NOTICE, "unknow status %d for %s",
839 				    fl->status, fl->client_name);
840 			}
841 		}
842 	}
843 	sigunlock();
844 }
845