xref: /openbsd/usr.sbin/rpc.lockd/lockd_lock.c (revision 7b36286a)
1 /*	$OpenBSD: lockd_lock.c,v 1.4 2008/06/15 04:48:03 sturm 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  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *	This product includes software developed by Manuel Bouyer.
17  * 4. The name of the author may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  */
33 
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <unistd.h>
37 #include <fcntl.h>
38 #include <inttypes.h>
39 #include <syslog.h>
40 #include <errno.h>
41 #include <string.h>
42 #include <signal.h>
43 #include <rpc/rpc.h>
44 #include <sys/socket.h>
45 #include <sys/stat.h>
46 #include <sys/param.h>
47 #include <sys/mount.h>
48 #include <sys/wait.h>
49 #include <rpcsvc/sm_inter.h>
50 #include <rpcsvc/nlm_prot.h>
51 #include "lockd_lock.h"
52 #include "lockd.h"
53 
54 /* A set of utilities for managing file locking */
55 LIST_HEAD(lcklst_head, file_lock);
56 struct lcklst_head lcklst_head = LIST_HEAD_INITIALIZER(lcklst_head);
57 
58 #define	FHANDLE_SIZE_MAX	1024	/* arbitrary big enough value */
59 typedef struct {
60 	size_t fhsize;
61 	char *fhdata;
62 } nfs_fhandle_t;
63 
64 static int
65 fhcmp(const nfs_fhandle_t *fh1, const nfs_fhandle_t *fh2)
66 {
67 	return memcmp(fh1->fhdata, fh2->fhdata, sizeof(fhandle_t));
68 }
69 
70 static int
71 fhconv(nfs_fhandle_t *fh, const netobj *rfh)
72 {
73 	size_t sz;
74 
75 	sz = rfh->n_len;
76 	if (sz > FHANDLE_SIZE_MAX) {
77 		syslog(LOG_DEBUG,
78 		    "received fhandle size %zd, max supported size %d",
79 		    sz, FHANDLE_SIZE_MAX);
80 		errno = EINVAL;
81 		return -1;
82 	}
83 	fh->fhdata = malloc(sz);
84 	if (fh->fhdata == NULL) {
85 		return -1;
86 	}
87 	fh->fhsize = sz;
88 	memcpy(fh->fhdata, rfh->n_bytes, sz);
89 	return 0;
90 }
91 
92 static void
93 fhfree(nfs_fhandle_t *fh)
94 {
95 
96 	free(fh->fhdata);
97 }
98 
99 /* struct describing a lock */
100 struct file_lock {
101 	LIST_ENTRY(file_lock) lcklst;
102 	nfs_fhandle_t filehandle; /* NFS filehandle */
103 	struct sockaddr_in *addr;
104 	struct nlm4_holder client; /* lock holder */
105 	netobj client_cookie; /* cookie sent by the client */
106 	char client_name[128];
107 	int nsm_status; /* status from the remote lock manager */
108 	int status; /* lock status, see below */
109 	int flags; /* lock flags, see lockd_lock.h */
110 	pid_t locker; /* pid of the child process trying to get the lock */
111 	int fd;	/* file descriptor for this lock */
112 };
113 
114 /* lock status */
115 #define LKST_LOCKED	1 /* lock is locked */
116 #define LKST_WAITING	2 /* file is already locked by another host */
117 #define LKST_PROCESSING	3 /* child is trying to acquire the lock */
118 #define LKST_DYING	4 /* must dies when we get news from the child */
119 
120 static struct file_lock *lalloc(void);
121 void lfree(struct file_lock *);
122 enum nlm_stats do_lock(struct file_lock *, int);
123 enum nlm_stats do_unlock(struct file_lock *);
124 void send_granted(struct file_lock *, int);
125 void siglock(void);
126 void sigunlock(void);
127 
128 /* list of hosts we monitor */
129 LIST_HEAD(hostlst_head, host);
130 struct hostlst_head hostlst_head = LIST_HEAD_INITIALIZER(hostlst_head);
131 
132 /* struct describing a lock */
133 struct host {
134 	LIST_ENTRY(host) hostlst;
135 	char name[SM_MAXSTRLEN+1];
136 	int refcnt;
137 };
138 
139 void do_mon(const char *);
140 
141 #define	LL_FH	0x01
142 #define	LL_NAME	0x02
143 #define	LL_SVID	0x04
144 
145 static struct file_lock *lock_lookup(struct file_lock *, int);
146 
147 /*
148  * lock_lookup: lookup a matching lock.
149  * called with siglock held.
150  */
151 static struct file_lock *
152 lock_lookup(struct file_lock *newfl, int flags)
153 {
154 	struct file_lock *fl;
155 
156 	LIST_FOREACH(fl, &lcklst_head, lcklst) {
157 		if ((flags & LL_SVID) != 0 &&
158 		    newfl->client.svid != fl->client.svid)
159 			continue;
160 		if ((flags & LL_NAME) != 0 &&
161 		    strcmp(newfl->client_name, fl->client_name) != 0)
162 			continue;
163 		if ((flags & LL_FH) != 0 &&
164 		    fhcmp(&newfl->filehandle, &fl->filehandle) != 0)
165 			continue;
166 		/* found */
167 		break;
168 	}
169 
170 	return fl;
171 }
172 
173 /*
174  * testlock(): inform the caller if the requested lock would be granted or not
175  * returns NULL if lock would granted, or pointer to the current nlm4_holder
176  * otherwise.
177  */
178 
179 struct nlm4_holder *
180 /*ARGSUSED*/
181 testlock(struct nlm4_lock *lock, int flags)
182 {
183 	struct file_lock *fl;
184 	nfs_fhandle_t filehandle;
185 
186 	/* convert lock to a local filehandle */
187 	if (fhconv(&filehandle, &lock->fh)) {
188 		syslog(LOG_NOTICE, "fhconv failed (%m)");
189 		return NULL; /* XXX */
190 	}
191 
192 	siglock();
193 	/* search through the list for lock holder */
194 	LIST_FOREACH(fl, &lcklst_head, lcklst) {
195 		if (fl->status != LKST_LOCKED)
196 			continue;
197 		if (fhcmp(&fl->filehandle, &filehandle) != 0)
198 			continue;
199 		/* got it ! */
200 		syslog(LOG_DEBUG, "test for %s: found lock held by %s",
201 		    lock->caller_name, fl->client_name);
202 		sigunlock();
203 		fhfree(&filehandle);
204 		return (&fl->client);
205 	}
206 	/* not found */
207 	sigunlock();
208 	fhfree(&filehandle);
209 	syslog(LOG_DEBUG, "test for %s: no lock found", lock->caller_name);
210 	return NULL;
211 }
212 
213 /*
214  * getlock: try to acquire the lock.
215  * If file is already locked and we can sleep, put the lock in the list with
216  * status LKST_WAITING; it'll be processed later.
217  * Otherwise try to lock. If we're allowed to block, fork a child which
218  * will do the blocking lock.
219  */
220 enum nlm_stats
221 getlock(nlm4_lockargs * lckarg, struct svc_req *rqstp, int flags)
222 {
223 	struct file_lock *fl, *newfl;
224 	enum nlm_stats retval;
225 	struct sockaddr_in *addr;
226 
227 	if (grace_expired == 0 && lckarg->reclaim == 0)
228 		return (flags & LOCK_V4) ?
229 		    nlm4_denied_grace_period : nlm_denied_grace_period;
230 
231 	/* allocate new file_lock for this request */
232 	newfl = lalloc();
233 	if (newfl == NULL) {
234 		syslog(LOG_NOTICE, "malloc failed (%m)");
235 		/* failed */
236 		return (flags & LOCK_V4) ?
237 		    nlm4_denied_nolock : nlm_denied_nolocks;
238 	}
239 	if (fhconv(&newfl->filehandle, &lckarg->alock.fh)) {
240 		syslog(LOG_NOTICE, "fhconv failed (%m)");
241 		lfree(newfl);
242 		/* failed */
243 		return (flags & LOCK_V4) ?
244 		    nlm4_denied_nolock : nlm_denied_nolocks;
245 	}
246 	addr = svc_getcaller(rqstp->rq_xprt);
247 	newfl->addr = malloc(addr->sin_len);
248 	if (newfl->addr == NULL) {
249 		syslog(LOG_NOTICE, "malloc failed (%m)");
250 		lfree(newfl);
251 		/* failed */
252 		return (flags & LOCK_V4) ?
253 		    nlm4_denied_nolock : nlm_denied_nolocks;
254 	}
255 	memcpy(newfl->addr, addr, addr->sin_len);
256 	newfl->client.exclusive = lckarg->exclusive;
257 	newfl->client.svid = lckarg->alock.svid;
258 	newfl->client.oh.n_bytes = malloc(lckarg->alock.oh.n_len);
259 	if (newfl->client.oh.n_bytes == NULL) {
260 		syslog(LOG_NOTICE, "malloc failed (%m)");
261 		lfree(newfl);
262 		return (flags & LOCK_V4) ?
263 		    nlm4_denied_nolock : nlm_denied_nolocks;
264 	}
265 	newfl->client.oh.n_len = lckarg->alock.oh.n_len;
266 	memcpy(newfl->client.oh.n_bytes, lckarg->alock.oh.n_bytes,
267 	    lckarg->alock.oh.n_len);
268 	newfl->client.l_offset = lckarg->alock.l_offset;
269 	newfl->client.l_len = lckarg->alock.l_len;
270 	newfl->client_cookie.n_len = lckarg->cookie.n_len;
271 	newfl->client_cookie.n_bytes = malloc(lckarg->cookie.n_len);
272 	if (newfl->client_cookie.n_bytes == NULL) {
273 		syslog(LOG_NOTICE, "malloc failed (%m)");
274 		lfree(newfl);
275 		return (flags & LOCK_V4) ?
276 		    nlm4_denied_nolock : nlm_denied_nolocks;
277 	}
278 	memcpy(newfl->client_cookie.n_bytes, lckarg->cookie.n_bytes,
279 	    lckarg->cookie.n_len);
280 	strlcpy(newfl->client_name, lckarg->alock.caller_name,
281 	    sizeof(newfl->client_name));
282 	newfl->nsm_status = lckarg->state;
283 	newfl->status = 0;
284 	newfl->flags = flags;
285 	siglock();
286 	/* look for a lock rq from this host for this fh */
287 	fl = lock_lookup(newfl, LL_FH|LL_NAME|LL_SVID);
288 	if (fl) {
289 		/* already locked by this host ??? */
290 		sigunlock();
291 		syslog(LOG_NOTICE, "duplicate lock from %s.%"
292 		    PRIu32,
293 		    newfl->client_name, newfl->client.svid);
294 		lfree(newfl);
295 		switch(fl->status) {
296 		case LKST_LOCKED:
297 			return (flags & LOCK_V4) ?
298 			    nlm4_granted : nlm_granted;
299 		case LKST_WAITING:
300 		case LKST_PROCESSING:
301 			return (flags & LOCK_V4) ?
302 			    nlm4_blocked : nlm_blocked;
303 		case LKST_DYING:
304 			return (flags & LOCK_V4) ?
305 			    nlm4_denied : nlm_denied;
306 		default:
307 			syslog(LOG_NOTICE, "bad status %d",
308 			    fl->status);
309 			return (flags & LOCK_V4) ?
310 			    nlm4_failed : nlm_denied;
311 		}
312 		/* NOTREACHED */
313 	}
314 	fl = lock_lookup(newfl, LL_FH);
315 	if (fl) {
316 		/*
317 		 * We already have a lock for this file.
318 		 * Put this one in waiting state if allowed to block
319 		 */
320 		if (lckarg->block) {
321 			syslog(LOG_DEBUG, "lock from %s.%" PRIu32 ": "
322 			    "already locked, waiting",
323 			    lckarg->alock.caller_name,
324 			    lckarg->alock.svid);
325 			newfl->status = LKST_WAITING;
326 			LIST_INSERT_HEAD(&lcklst_head, newfl, lcklst);
327 			do_mon(lckarg->alock.caller_name);
328 			sigunlock();
329 			return (flags & LOCK_V4) ?
330 			    nlm4_blocked : nlm_blocked;
331 		} else {
332 			sigunlock();
333 			syslog(LOG_DEBUG, "lock from %s.%" PRIu32 ": "
334 			    "already locked, failed",
335 			    lckarg->alock.caller_name,
336 			    lckarg->alock.svid);
337 			lfree(newfl);
338 			return (flags & LOCK_V4) ?
339 			    nlm4_denied : nlm_denied;
340 		}
341 		/* NOTREACHED */
342 	}
343 
344 	/* no entry for this file yet; add to list */
345 	LIST_INSERT_HEAD(&lcklst_head, newfl, lcklst);
346 	/* do the lock */
347 	retval = do_lock(newfl, lckarg->block);
348 	switch (retval) {
349 	case nlm4_granted:
350 	/* case nlm_granted: is the same as nlm4_granted */
351 	case nlm4_blocked:
352 	/* case nlm_blocked: is the same as nlm4_blocked */
353 		do_mon(lckarg->alock.caller_name);
354 		break;
355 	default:
356 		lfree(newfl);
357 		break;
358 	}
359 	sigunlock();
360 	return retval;
361 }
362 
363 /* unlock a filehandle */
364 enum nlm_stats
365 unlock(nlm4_lock *lck, int flags)
366 {
367 	struct file_lock *fl;
368 	nfs_fhandle_t filehandle;
369 	int err = (flags & LOCK_V4) ? nlm4_granted : nlm_granted;
370 
371 	if (fhconv(&filehandle, &lck->fh)) {
372 		syslog(LOG_NOTICE, "fhconv failed (%m)");
373 		return (flags & LOCK_V4) ? nlm4_denied : nlm_denied;
374 	}
375 	siglock();
376 	LIST_FOREACH(fl, &lcklst_head, lcklst) {
377 		if (strcmp(fl->client_name, lck->caller_name) ||
378 		    fhcmp(&filehandle, &fl->filehandle) != 0 ||
379 		    fl->client.oh.n_len != lck->oh.n_len ||
380 		    memcmp(fl->client.oh.n_bytes, lck->oh.n_bytes,
381 			fl->client.oh.n_len) != 0 ||
382 		    fl->client.svid != lck->svid)
383 			continue;
384 		/* Got it, unlock and remove from the queue */
385 		syslog(LOG_DEBUG, "unlock from %s.%" PRIu32 ": found struct, "
386 		    "status %d", lck->caller_name, lck->svid, fl->status);
387 		switch (fl->status) {
388 		case LKST_LOCKED:
389 			err = do_unlock(fl);
390 			break;
391 		case LKST_WAITING:
392 			/* remove from the list */
393 			LIST_REMOVE(fl, lcklst);
394 			lfree(fl);
395 			break;
396 		case LKST_PROCESSING:
397 			/*
398 			 * being handled by a child; will clean up
399 			 * when the child exits
400 			 */
401 			fl->status = LKST_DYING;
402 			break;
403 		case LKST_DYING:
404 			/* nothing to do */
405 			break;
406 		default:
407 			syslog(LOG_NOTICE, "unknow status %d for %s",
408 			    fl->status, fl->client_name);
409 		}
410 		sigunlock();
411 		fhfree(&filehandle);
412 		return err;
413 	}
414 	sigunlock();
415 	/* didn't find a matching entry; log anyway */
416 	syslog(LOG_NOTICE, "no matching entry for %s",
417 	    lck->caller_name);
418 	fhfree(&filehandle);
419 	return (flags & LOCK_V4) ? nlm4_granted : nlm_granted;
420 }
421 
422 static struct file_lock *
423 lalloc(void)
424 {
425 	return calloc(1, sizeof(struct file_lock));
426 }
427 
428 void
429 lfree(struct file_lock *fl)
430 {
431 	free(fl->addr);
432 	free(fl->client.oh.n_bytes);
433 	free(fl->client_cookie.n_bytes);
434 	fhfree(&fl->filehandle);
435 	free(fl);
436 }
437 
438 void
439 /*ARGSUSED*/
440 sigchild_handler(int sig)
441 {
442 	int sstatus;
443 	pid_t pid;
444 	struct file_lock *fl;
445 
446 	for (;;) {
447 		pid = wait4(-1, &sstatus, WNOHANG, NULL);
448 		if (pid == -1) {
449 			if (errno != ECHILD)
450 				syslog(LOG_NOTICE, "wait failed (%m)");
451 			else
452 				syslog(LOG_DEBUG, "wait failed (%m)");
453 			return;
454 		}
455 		if (pid == 0) {
456 			/* no more child to handle yet */
457 			return;
458 		}
459 		/*
460 		 * if we're here we have a child that exited
461 		 * Find the associated file_lock.
462 		 */
463 		LIST_FOREACH(fl, &lcklst_head, lcklst) {
464 			if (pid == fl->locker)
465 				break;
466 		}
467 		if (fl == NULL) {
468 			syslog(LOG_NOTICE, "unknown child %d", pid);
469 		} else {
470 			/* protect from pid reusing. */
471 			fl->locker = 0;
472 			if (!WIFEXITED(sstatus) || WEXITSTATUS(sstatus) != 0) {
473 				syslog(LOG_NOTICE, "child %d failed", pid);
474 				/*
475 				 * can't do much here; we can't reply
476 				 * anything but OK for blocked locks
477 				 * Eventually the client will time out
478 				 * and retry.
479 				 */
480 				do_unlock(fl);
481 				return;
482 			}
483 
484 			/* check lock status */
485 			syslog(LOG_DEBUG, "processing child %d, status %d",
486 			    pid, fl->status);
487 			switch(fl->status) {
488 			case LKST_PROCESSING:
489 				fl->status = LKST_LOCKED;
490 				send_granted(fl, (fl->flags & LOCK_V4) ?
491 				    nlm4_granted : nlm_granted);
492 				break;
493 			case LKST_DYING:
494 				do_unlock(fl);
495 				break;
496 			default:
497 				syslog(LOG_NOTICE, "bad lock status (%d) for"
498 				   " child %d", fl->status, pid);
499 			}
500 		}
501 	}
502 }
503 
504 /*
505  *
506  * try to acquire the lock described by fl. Eventually fock a child to do a
507  * blocking lock if allowed and required.
508  */
509 
510 enum nlm_stats
511 do_lock(struct file_lock *fl, int block)
512 {
513 	int lflags, error;
514 	struct stat st;
515 
516 	fl->fd = fhopen((fhandle_t *)fl->filehandle.fhdata, O_RDWR);
517 	if (fl->fd < 0) {
518 		switch (errno) {
519 		case ESTALE:
520 			error = nlm4_stale_fh;
521 			break;
522 		case EROFS:
523 			error = nlm4_rofs;
524 			break;
525 		default:
526 			error = nlm4_failed;
527 		}
528 		if ((fl->flags & LOCK_V4) == 0)
529 			error = nlm_denied;
530 		syslog(LOG_NOTICE, "fhopen failed (from %s) (%m)",
531 		    fl->client_name);
532 		LIST_REMOVE(fl, lcklst);
533 		return error;
534 	}
535 	if (fstat(fl->fd, &st) < 0) {
536 		syslog(LOG_NOTICE, "fstat failed (from %s) (%m)",
537 		    fl->client_name);
538 	}
539 	syslog(LOG_DEBUG, "lock from %s.%" PRIu32 " for file%s%s: "
540 	    "dev %u ino %d (uid %d), flags %d",
541 	    fl->client_name, fl->client.svid,
542 	    fl->client.exclusive ? " (exclusive)":"", block ? " (block)":"",
543 	    st.st_dev, st.st_ino, st.st_uid, fl->flags);
544 	lflags = LOCK_NB;
545 	if (fl->client.exclusive == 0)
546 		lflags |= LOCK_SH;
547 	else
548 		lflags |= LOCK_EX;
549 	error = flock(fl->fd, lflags);
550 	if (error != 0 && errno == EAGAIN && block) {
551 		switch (fl->locker = fork()) {
552 		case -1: /* fork failed */
553 			syslog(LOG_NOTICE, "fork failed (%m)");
554 			LIST_REMOVE(fl, lcklst);
555 			close(fl->fd);
556 			return (fl->flags & LOCK_V4) ?
557 			    nlm4_denied_nolock : nlm_denied_nolocks;
558 		case 0:
559 			/*
560 			 * Attempt a blocking lock. Will have to call
561 			 * NLM_GRANTED later.
562 			 */
563 			setproctitle("%s.%" PRIu32,
564 			    fl->client_name, fl->client.svid);
565 			lflags &= ~LOCK_NB;
566 			if(flock(fl->fd, lflags) != 0) {
567 				syslog(LOG_NOTICE, "flock failed (%m)");
568 				_exit(1);
569 			}
570 			/* lock granted */
571 			_exit(0);
572 			/*NOTREACHED*/
573 		default:
574 			syslog(LOG_DEBUG, "lock request from %s.%" PRIu32 ": "
575 			    "forked %d",
576 			    fl->client_name, fl->client.svid, fl->locker);
577 			fl->status = LKST_PROCESSING;
578 			return (fl->flags & LOCK_V4) ?
579 			    nlm4_blocked : nlm_blocked;
580 		}
581 	}
582 	/* non block case */
583 	if (error != 0) {
584 		switch (errno) {
585 		case EAGAIN:
586 			error = nlm4_denied;
587 			break;
588 		case ESTALE:
589 			error = nlm4_stale_fh;
590 			break;
591 		case EROFS:
592 			error = nlm4_rofs;
593 			break;
594 		default:
595 			error = nlm4_failed;
596 		}
597 		if ((fl->flags & LOCK_V4) == 0)
598 			error = nlm_denied;
599 		if (errno != EAGAIN)
600 			syslog(LOG_NOTICE, "flock for %s failed (%m)",
601 			    fl->client_name);
602 		else syslog(LOG_DEBUG, "flock for %s failed (%m)",
603 			    fl->client_name);
604 		LIST_REMOVE(fl, lcklst);
605 		close(fl->fd);
606 		return error;
607 	}
608 	fl->status = LKST_LOCKED;
609 	return (fl->flags & LOCK_V4) ? nlm4_granted : nlm_granted;
610 }
611 
612 void
613 /*ARGSUSED*/
614 send_granted(struct file_lock *fl, int opcode)
615 {
616 	CLIENT *cli;
617 	static char dummy;
618 	struct timeval timeo;
619 	int success;
620 	static struct nlm_res retval;
621 	static struct nlm4_res retval4;
622 
623 	cli = get_client(fl->addr,
624 	    (fl->flags & LOCK_V4) ? NLM_VERS4 : NLM_VERS);
625 	if (cli == NULL) {
626 		syslog(LOG_NOTICE, "failed to get CLIENT for %s.%" PRIu32,
627 		    fl->client_name, fl->client.svid);
628 		/*
629 		 * We fail to notify remote that the lock has been granted.
630 		 * The client will timeout and retry, the lock will be
631 		 * granted at this time.
632 		 */
633 		return;
634 	}
635 	timeo.tv_sec = 0;
636 	timeo.tv_usec = (fl->flags & LOCK_ASYNC) ? 0 : 500000; /* 0.5s */
637 
638 	if (fl->flags & LOCK_V4) {
639 		static nlm4_testargs result;
640 		result.cookie = fl->client_cookie;
641 		result.exclusive = fl->client.exclusive;
642 		result.alock.caller_name = fl->client_name;
643 		result.alock.fh.n_len = fl->filehandle.fhsize;
644 		result.alock.fh.n_bytes = fl->filehandle.fhdata;
645 		result.alock.oh = fl->client.oh;
646 		result.alock.svid = fl->client.svid;
647 		result.alock.l_offset = fl->client.l_offset;
648 		result.alock.l_len = fl->client.l_len;
649 		syslog(LOG_DEBUG, "sending v4 reply%s",
650 		    (fl->flags & LOCK_ASYNC) ? " (async)":"");
651 		if (fl->flags & LOCK_ASYNC) {
652 			success = clnt_call(cli, NLM4_GRANTED_MSG,
653 			    xdr_nlm4_testargs, &result, xdr_void, &dummy, timeo);
654 		} else {
655 			success = clnt_call(cli, NLM4_GRANTED,
656 			    xdr_nlm4_testargs, &result, xdr_nlm4_res,
657 			    &retval4, timeo);
658 		}
659 	} else {
660 		static nlm_testargs result;
661 
662 		result.cookie = fl->client_cookie;
663 		result.exclusive = fl->client.exclusive;
664 		result.alock.caller_name = fl->client_name;
665 		result.alock.fh.n_len = fl->filehandle.fhsize;
666 		result.alock.fh.n_bytes = fl->filehandle.fhdata;
667 		result.alock.oh = fl->client.oh;
668 		result.alock.svid = fl->client.svid;
669 		result.alock.l_offset =
670 		    (unsigned int)fl->client.l_offset;
671 		result.alock.l_len =
672 		    (unsigned int)fl->client.l_len;
673 		syslog(LOG_DEBUG, "sending v1 reply%s",
674 		    (fl->flags & LOCK_ASYNC) ? " (async)":"");
675 		if (fl->flags & LOCK_ASYNC) {
676 			success = clnt_call(cli, NLM_GRANTED_MSG,
677 			    xdr_nlm_testargs, &result, xdr_void, &dummy, timeo);
678 		} else {
679 			success = clnt_call(cli, NLM_GRANTED,
680 			    xdr_nlm_testargs, &result, xdr_nlm_res,
681 			    &retval, timeo);
682 		}
683 	}
684 	if (debug_level > 2)
685 		syslog(LOG_DEBUG, "clnt_call returns %d(%s) for granted",
686 		    success, clnt_sperrno(success));
687 
688 }
689 
690 enum nlm_stats
691 do_unlock(struct file_lock *rfl)
692 {
693 	struct file_lock *fl;
694 	int error;
695 	int lockst;
696 
697 	/* unlock the file: closing is enough ! */
698 	if (close(rfl->fd) == -1) {
699 		if (errno == ESTALE)
700 			error = nlm4_stale_fh;
701 		else
702 			error = nlm4_failed;
703 		if ((rfl->flags & LOCK_V4) == 0)
704 			error = nlm_denied;
705 		syslog(LOG_NOTICE, "close failed (from %s) (%m)",
706 		    rfl->client_name);
707 	} else {
708 		error = (rfl->flags & LOCK_V4) ?
709 		    nlm4_granted : nlm_granted;
710 	}
711 	LIST_REMOVE(rfl, lcklst);
712 
713 	/* process the next LKST_WAITING lock request for this fh */
714 	LIST_FOREACH(fl, &lcklst_head, lcklst) {
715 		if (fl->status != LKST_WAITING ||
716 		    fhcmp(&rfl->filehandle, &fl->filehandle) != 0)
717 			continue;
718 
719 		lockst = do_lock(fl, 1); /* If it's LKST_WAITING we can block */
720 		switch (lockst) {
721 		case nlm4_granted:
722 		/* case nlm_granted: same as nlm4_granted */
723 			send_granted(fl, (fl->flags & LOCK_V4) ?
724 			    nlm4_granted : nlm_granted);
725 			break;
726 		case nlm4_blocked:
727 		/* case nlm_blocked: same as nlm4_blocked */
728 			break;
729 		default:
730 			lfree(fl);
731 			break;
732 		}
733 		break;
734 	}
735 	lfree(rfl);
736 	return error;
737 }
738 
739 void
740 siglock(void)
741 {
742 	sigset_t block;
743 
744 	sigemptyset(&block);
745 	sigaddset(&block, SIGCHLD);
746 
747 	if (sigprocmask(SIG_BLOCK, &block, NULL) < 0) {
748 		syslog(LOG_WARNING, "siglock failed (%m)");
749 	}
750 }
751 
752 void
753 sigunlock(void)
754 {
755 	sigset_t block;
756 
757 	sigemptyset(&block);
758 	sigaddset(&block, SIGCHLD);
759 
760 	if (sigprocmask(SIG_UNBLOCK, &block, NULL) < 0) {
761 		syslog(LOG_WARNING, "sigunlock failed (%m)");
762 	}
763 }
764 
765 /* monitor a host through rpc.statd, and keep a ref count */
766 void
767 do_mon(const char *hostname)
768 {
769 	static char localhost[] = "localhost";
770 	struct host *hp;
771 	struct mon my_mon;
772 	struct sm_stat_res result;
773 	int retval;
774 
775 	LIST_FOREACH(hp, &hostlst_head, hostlst) {
776 		if (strcmp(hostname, hp->name) == 0) {
777 			/* already monitored, just bump refcnt */
778 			hp->refcnt++;
779 			return;
780 		}
781 	}
782 	/* not found, have to create an entry for it */
783 	hp = malloc(sizeof(struct host));
784 	if (hp == NULL) {
785 		syslog(LOG_WARNING, "can't monitor host %s (%m)", hostname);
786 		return;
787 	}
788 	strlcpy(hp->name, hostname, sizeof(hp->name));
789 	hp->refcnt = 1;
790 	syslog(LOG_DEBUG, "monitoring host %s", hostname);
791 	memset(&my_mon, 0, sizeof(my_mon));
792 	my_mon.mon_id.mon_name = hp->name;
793 	my_mon.mon_id.my_id.my_name = localhost;
794 	my_mon.mon_id.my_id.my_prog = NLM_PROG;
795 	my_mon.mon_id.my_id.my_vers = NLM_SM;
796 	my_mon.mon_id.my_id.my_proc = NLM_SM_NOTIFY;
797 	if ((retval = callrpc(localhost, SM_PROG, SM_VERS, SM_MON, xdr_mon,
798 	    (void *)&my_mon, xdr_sm_stat_res, (void *)&result)) != 0) {
799 		syslog(LOG_WARNING, "rpc to statd failed (%s)",
800 		    clnt_sperrno((enum clnt_stat)retval));
801 		free(hp);
802 		return;
803 	}
804 	if (result.res_stat == stat_fail) {
805 		syslog(LOG_WARNING, "statd failed");
806 		free(hp);
807 		return;
808 	}
809 	LIST_INSERT_HEAD(&hostlst_head, hp, hostlst);
810 }
811 
812 void
813 notify(const char *hostname, int state)
814 {
815 	struct file_lock *fl, *next_fl;
816 	int err;
817 	syslog(LOG_DEBUG, "notify from %s, new state %d", hostname, state);
818 	/* search all lock for this host; if status changed, release the lock */
819 	siglock();
820 	for (fl = LIST_FIRST(&lcklst_head); fl != NULL; fl = next_fl) {
821 		next_fl = LIST_NEXT(fl, lcklst);
822 		if (strcmp(hostname, fl->client_name) == 0 &&
823 		    fl->nsm_status != state) {
824 			syslog(LOG_DEBUG, "state %d, nsm_state %d, unlocking",
825 			    fl->status, fl->nsm_status);
826 			switch(fl->status) {
827 			case LKST_LOCKED:
828 				err = do_unlock(fl);
829 				if (err != nlm_granted)
830 					syslog(LOG_DEBUG,
831 					    "notify: unlock failed for %s (%d)",
832 			    		    hostname, err);
833 				break;
834 			case LKST_WAITING:
835 				LIST_REMOVE(fl, lcklst);
836 				lfree(fl);
837 				break;
838 			case LKST_PROCESSING:
839 				fl->status = LKST_DYING;
840 				break;
841 			case LKST_DYING:
842 				break;
843 			default:
844 				syslog(LOG_NOTICE, "unknow status %d for %s",
845 				    fl->status, fl->client_name);
846 			}
847 		}
848 	}
849 	sigunlock();
850 }
851