1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2010 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 #include <signal.h>
27 #include <sys/types.h>
28 #include <sys/time.h>
29 #include <sys/socket.h>
30 #include <netinet/in.h>
31 #include <netinet/tcp.h>
32 #include <arpa/inet.h>
33 #include <netdb.h>
34 #include <fcntl.h>
35 #include <string.h>
36 #include <memory.h>
37 #include <sys/param.h>
38 #include <sys/pathconf.h>
39 #include <netdir.h>
40 #include <netconfig.h>
41 #include <sys/sockio.h>
42 #include <net/if.h>
43 #include <sys/resource.h>
44 #include <stdio.h>
45 #include <errno.h>
46 #include <assert.h>
47 #include <locale.h>
48 #include <unistd.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <strings.h>
52 #include <sys/unistat/spcs_s.h>
53 #include <sys/unistat/spcs_s_u.h>
54 #include <sys/unistat/spcs_errors.h>
55
56 #include <sys/nsctl/cfg.h>
57 #include <sys/nsctl/cfg_lockd.h>
58
59 #ifdef DEBUG
60 #define DPF(m) if (debug) (void) fprintf m
61 #else
62 #define DPF(m)
63 #endif
64
65 #ifdef TTY_MESSAGES
66 #define CLOSE_FD 3
67 #else
68 #define CLOSE_FD 0
69 #endif
70
71 #define MAX_LOCKQ 1024
72 #define MAX_DAEMONS 1024
73 #define MAX_LOCAL 1024
74 #define MAX_UNLOCK 32
75 #define MAX_TIMEOUTS 3
76 #define TIMEOUT_SECS 5
77
78 static char program[] = "dscfglockd";
79 static int debug;
80 static int lstate;
81 static int msgtrace;
82 static FILE *debugfile = NULL;
83
84 struct lock_req {
85 cfglockd_t type; /* read or write */
86 pid_t pid; /* pid of read locker or local writer */
87 daemonaddr_t remote; /* remote machine requesting write lock */
88 int state; /* for write locks */
89 int32_t order; /* who gets priority? */
90 } lock_queue[MAX_LOCKQ];
91
92 struct unlock_s {
93 pid_t pid; /* pid of locker */
94 uint8_t seq; /* seq number of last lock request */
95 } unlock_buf[MAX_UNLOCK];
96
97 int next_req;
98 int32_t order;
99
100 #define lock_wanted lock_queue[0]
101 long ticker = 1l;
102
103 #define ALIVE 0x10
104 #define READ_LOCK 0x11
105 #define WRITE_LOCK 0x12
106 #define UNLOCK 0x13
107 #define GRANTED 0x14
108
109 int next_q;
110
111 struct {
112 cfglockd_t type;
113 int nholders;
114 int state;
115 daemonaddr_t holder;
116 struct lockdaemon *remote_daemon;
117 pid_t holding_pid[MAX_LOCAL];
118 } the_lock;
119
120 daemonaddr_t thishost;
121 daemonaddr_t localhost;
122
123 #define STATE_CLEAR 0
124 #define STATE_ASKED 1
125 #define STATE_OKAYED 2
126 #define STATE_WANTS 3
127 #define lockdaemon_dead(ldp) ((ticker - (ldp)->timeout) > MAX_TIMEOUTS)
128 #define CRIT_BEGIN() (void) sighold(SIGALRM)
129 #define CRIT_END() (void) sigrelse(SIGALRM)
130
131 #define NORMAL_UNLOCK 0
132 #define FORCE_UNLOCK 1
133
134 struct lockdaemon {
135 daemonaddr_t host;
136 int up;
137 long timeout;
138 int inuse;
139 int state;
140 int32_t order;
141 } daemon_list[MAX_DAEMONS];
142
143 unsigned short lock_port = CFG_SERVER_PORT;
144 int lock_soc = 0;
145 int pf_inet = PF_INET;
146 #define dp_addr(p) inet_ntoa(((struct sockaddr_in *)p)->sin_addr)
147
148 #define MAXIFS 32
149
150 static char *
151 lockd_type(cfglockd_t type)
152 {
153 switch (type) {
154 case LOCK_NOTLOCKED: return "NotLocked";
155 case LOCK_READ: return "Read";
156 case LOCK_WRITE: return "Write";
157 case LOCK_LOCKED: return "Locked";
158 case LOCK_LOCKEDBY: return "LockedBy";
159 case LOCK_STAT: return "Stat";
160 case LOCK_ACK: return "Ack";
161 default: return "*unknown*";
162 }
163 }
164
165 static char *
166 lockd_state(int state)
167 {
168 switch (state) {
169 case STATE_CLEAR: return "Clear";
170 case STATE_ASKED: return "Asked";
171 case STATE_OKAYED: return "Okayed";
172 case STATE_WANTS: return "Wants";
173 default: return "*unknown*";
174 }
175 }
176
177 static char *
178 lockd_msg(int message)
179 {
180 switch (message) {
181 case ALIVE: return "Alive";
182 case READ_LOCK: return "ReadLock";
183 case WRITE_LOCK: return "WriteLock";
184 case UNLOCK: return "Unlock";
185 case GRANTED: return "Granted";
186 default: return lockd_type((cfglockd_t)message);
187 }
188 }
189
190 /*
191 * The following is stolen from autod_nfs.c
192 */
193 static void
194 getmyaddrs(struct ifconf *ifc)
195 {
196 int sock;
197 int numifs;
198 char *buf;
199 int family;
200
201 ifc->ifc_buf = NULL;
202 ifc->ifc_len = 0;
203
204 #ifdef AF_INET6
205 family = AF_INET6;
206 #else
207 family = AF_INET;
208 #endif
209 if ((sock = socket(family, SOCK_DGRAM, 0)) < 0) {
210 #ifdef DEBUG
211 perror("getmyaddrs(): socket");
212 #endif
213 return;
214 }
215
216 if (ioctl(sock, SIOCGIFNUM, (char *)&numifs) < 0) {
217 #ifdef DEBUG
218 perror("getmyaddrs(): SIOCGIFNUM");
219 #endif
220 numifs = MAXIFS;
221 }
222
223 buf = (char *)malloc(numifs * sizeof (struct ifreq));
224 if (buf == NULL) {
225 #ifdef DEBUG
226 (void) fprintf(stderr, "getmyaddrs(): malloc failed\n");
227 #endif
228 (void) close(sock);
229 return;
230 }
231
232 ifc->ifc_buf = buf;
233 ifc->ifc_len = numifs * sizeof (struct ifreq);
234
235 if (ioctl(sock, SIOCGIFCONF, (char *)ifc) < 0) {
236 #ifdef DEBUG
237 perror("getmyaddrs(): SIOCGIFCONF");
238 #endif
239 }
240
241 (void) close(sock);
242 }
243
244 struct ifconf *ifc;
245
246 static int
247 cmp_addr(daemonaddr_t *a, daemonaddr_t *b)
248 {
249 int rc;
250 rc = memcmp(&(a->sin_addr), &(b->sin_addr), sizeof (a->sin_addr));
251 DPF((stderr, "compare %s %hu with", dp_addr(a), a->sin_port));
252 DPF((stderr, " %s %hu = %d\n", dp_addr(b), b->sin_port, rc));
253 return (rc);
254 }
255
256 static int
257 addr_is_holder(int32_t order)
258 {
259 return ((the_lock.nholders > 0) && the_lock.remote_daemon != NULL &&
260 (order == the_lock.remote_daemon->order));
261 }
262
263 static int
264 islocalhost(daemonaddr_t *host)
265 {
266 int n;
267 struct sockaddr_in *s1, *s2;
268 struct ifreq *ifr;
269 int retval = 0;
270
271 ifr = ifc->ifc_req;
272 n = ifc->ifc_len / sizeof (struct ifreq);
273 s1 = host;
274 s2 = NULL;
275 for (; n > 0; n--, ifr++) {
276 if (ifr->ifr_addr.sa_family != AF_INET)
277 continue;
278
279 /* LINTED pointer alignment */
280 s2 = (struct sockaddr_in *)&ifr->ifr_addr;
281
282 if (memcmp((char *)&s2->sin_addr,
283 (char *)&s1->sin_addr, sizeof (s1->sin_addr)) == 0) {
284 retval = 1;
285 /* it's me */
286 break;
287 }
288 }
289 return (retval);
290 }
291
292 static void
293 send_lockmsg(int cmd, pid_t pid, daemonaddr_t *dp, uint8_t seq)
294 {
295 struct lock_msg message_buf;
296 int rc;
297
298 if (msgtrace && debugfile) {
299 time_t t = time(0);
300 (void) fprintf(debugfile, "%19.19s send %-9.9s to %s\n",
301 ctime(&t), lockd_msg(cmd), dp_addr(dp));
302 }
303 DPF((stderr, "send %d to %s port %hu\n", cmd,
304 dp_addr(dp), dp->sin_port));
305 message_buf.message = cmd;
306 message_buf.pid = pid;
307 message_buf.order = order;
308 message_buf.seq = seq;
309 do {
310 rc = sendto(lock_soc, &message_buf, sizeof (message_buf), 0,
311 (struct sockaddr *)dp, sizeof (struct sockaddr));
312 } while (rc == -1 && errno == EINTR);
313 if (rc == -1)
314 spcs_log("cfglockd", NULL, "sendto rc -1 errno %d", errno);
315 }
316
317 /*
318 * send an alive message to all configured daemons so that they can tell
319 * us if they are holding a write lock.
320 */
321
322 static void
323 send_aliveall()
324 {
325 struct lockdaemon *ldp;
326 int i;
327 for (i = 0, ldp = daemon_list; i < MAX_DAEMONS; i++, ldp++) {
328 if (ldp->inuse == 0)
329 break;
330 send_lockmsg(ALIVE, (pid_t)0, &(ldp->host), 0);
331 }
332 }
333
334 /* find the lock daemon structure for a give daemon address */
335
336 static struct lockdaemon *
337 find_lockdaemon(daemonaddr_t *d)
338 {
339 struct lockdaemon *ldp;
340 int i;
341 for (i = 0, ldp = daemon_list; i < MAX_DAEMONS; i++, ldp++) {
342 if (ldp->inuse == 0)
343 break;
344 if (cmp_addr(&(ldp->host), d) == 0)
345 return (ldp);
346 }
347 return (NULL);
348 }
349
350 /*
351 * a messge has been received from daemon, note this and if the daemon
352 * was previously dead and we have the write lock tell it that we do.
353 */
354
355 static void
356 daemon_alive(daemonaddr_t *daemon, int32_t order)
357 {
358 struct lockdaemon *ldp;
359 int i;
360
361 for (i = 0, ldp = daemon_list; i < MAX_DAEMONS; i++, ldp++) {
362 if (ldp->inuse == 0)
363 break;
364 if (cmp_addr(&(ldp->host), daemon) == 0) {
365 ldp->order = order;
366 ldp->timeout = ticker;
367 if (ldp->up == 0) {
368 spcs_log("cfglockd", NULL,
369 "daemon restarted on %s\n",
370 dp_addr(daemon));
371 DPF((stderr, "daemon restarted on %s\n",
372 dp_addr(daemon)));
373 ldp->up = 1;
374 goto come_up;
375 }
376 return;
377 }
378 }
379 /* new daemon has announced itself */
380 if (i < MAX_DAEMONS) {
381 DPF((stderr, "new daemon on %s\n", dp_addr(daemon)));
382 spcs_log("cfglockd", NULL,
383 "new daemon on %s\n", dp_addr(daemon));
384 ldp->host = *daemon;
385 ldp->inuse = 1;
386 ldp->timeout = ticker;
387 ldp->order = order;
388 } else {
389 /* problem, more daemons than expected */
390 i++;
391 }
392 come_up:
393 if (the_lock.type == LOCK_WRITE && the_lock.remote_daemon == NULL)
394 send_lockmsg(WRITE_LOCK, (pid_t)0, daemon, 0);
395 }
396
397 static void
398 delete_queue_entry(struct lock_req *req)
399 {
400 int i;
401
402 for (i = (req - lock_queue); i++ < next_req; req++)
403 *req = *(req+1);
404 next_req--;
405 }
406
407 static void
408 take_lock(int ackmessage)
409 {
410 send_lockmsg(ackmessage, (pid_t)0, &lock_wanted.remote, 0);
411 delete_queue_entry(lock_queue);
412 }
413
414 static void
415 check_for_write_lock()
416 {
417 struct lockdaemon *ldp;
418 int i;
419 int wait = 0;
420
421 DPF((stderr, "check for lock\n"));
422 if (lock_wanted.state != STATE_ASKED)
423 return;
424 for (i = 0, ldp = daemon_list; i < MAX_DAEMONS; i++, ldp++) {
425 if (ldp->inuse == 0)
426 break;
427 if (ldp->up && ldp->state != STATE_OKAYED) {
428 wait = 1;
429 break;
430 }
431 }
432 if (wait == 0 && lock_wanted.type == LOCK_WRITE) {
433 the_lock.type = LOCK_WRITE;
434 the_lock.holding_pid[0] = lock_wanted.pid;
435 the_lock.nholders = 1;
436 the_lock.state = STATE_CLEAR;
437 take_lock(LOCK_LOCKED);
438 }
439 }
440
441 static void
442 lock_granted(daemonaddr_t *da)
443 {
444 struct lockdaemon *ldp;
445
446 if ((ldp = find_lockdaemon(da)) != NULL) {
447 /* if we already own the lock, throw the msg away */
448 if (the_lock.remote_daemon == NULL &&
449 the_lock.type == LOCK_WRITE) {
450 return;
451 }
452
453 /*
454 * If the current lock isn't a write lock and we're not
455 * asking for one
456 * -OR-
457 * The current lock is a write lock and it's not owned by us
458 * -THEN-
459 * send back an unlocked message.
460 */
461 if ((the_lock.type != LOCK_WRITE &&
462 the_lock.state != STATE_ASKED) ||
463 (the_lock.type == LOCK_WRITE &&
464 the_lock.remote_daemon != NULL)) {
465 send_lockmsg(UNLOCK, (pid_t)0, &(ldp->host), 0);
466 return;
467 }
468 ldp->state = STATE_OKAYED;
469 }
470 check_for_write_lock();
471 }
472
473 static int
474 try_lock()
475 {
476 struct lockdaemon *ldp;
477 int i;
478
479 switch (the_lock.type) {
480 case LOCK_READ:
481 if (lock_wanted.type == LOCK_READ) {
482 i = the_lock.nholders++;
483 the_lock.holding_pid[i] = lock_wanted.pid;
484 the_lock.state = STATE_CLEAR;
485 DPF((stderr, "increment read lockers to %d\n",
486 the_lock.nholders));
487 take_lock(LOCK_LOCKED);
488 break;
489 }
490 /* write lock has to wait */
491 break;
492 case LOCK_WRITE:
493 /* lock has to wait until write lock is cleared */
494 break;
495 case LOCK_NOTLOCKED:
496 if (lock_wanted.type == LOCK_READ) {
497 DPF((stderr, "local locker, 1 lock holder\n"));
498 the_lock.holding_pid[0] = lock_wanted.pid;
499 the_lock.nholders = 1;
500 the_lock.type = LOCK_READ;
501 the_lock.state = STATE_CLEAR;
502 the_lock.remote_daemon = NULL;
503 take_lock(LOCK_LOCKED);
504 return (1);
505 }
506 if (islocalhost(&lock_wanted.remote)) {
507 DPF((stderr, "local locker, take write lock\n"));
508 /* tell everyone I'm locking */
509 if (lock_wanted.state != STATE_ASKED) {
510 for (i = 0, ldp = daemon_list; i < MAX_DAEMONS;
511 i++, ldp++) {
512 if (ldp->inuse == 0)
513 break;
514 ldp->state = STATE_ASKED;
515 send_lockmsg(WRITE_LOCK, (pid_t)0,
516 &(ldp->host), 0);
517 }
518 }
519 lock_wanted.state = STATE_ASKED;
520 check_for_write_lock();
521 the_lock.remote_daemon = NULL;
522 the_lock.state = STATE_ASKED;
523 return (0);
524 } else {
525 DPF((stderr, "remote locker, take write lock\n"));
526 the_lock.type = LOCK_WRITE;
527 the_lock.holder = lock_wanted.remote;
528 the_lock.nholders = 1;
529 the_lock.remote_daemon =
530 find_lockdaemon(&the_lock.holder);
531 the_lock.state = STATE_CLEAR;
532 /* okay to remote */
533 take_lock(GRANTED);
534 }
535 break;
536 default:
537 DPF((stderr, "weird lock type held - %d\n", the_lock.type));
538 the_lock.type = LOCK_NOTLOCKED;
539 break;
540 }
541 return (0);
542 }
543
544 static void
545 process_queue()
546 {
547 if (next_req < 1)
548 return; /* no locks queued */
549 while (try_lock())
550 ;
551 }
552
553 static int
554 lock_sort(const void *a, const void *b)
555 {
556 struct lock_req *left = (struct lock_req *)a;
557 struct lock_req *right = (struct lock_req *)b;
558
559 return (left->order - right->order);
560 }
561
562 static void
563 queue_lock(cfglockd_t type, struct lock_msg *msg, daemonaddr_t *addr)
564 {
565 int i;
566 struct lock_req *lrp;
567 struct lockdaemon *ldp;
568
569 /* first check if new lock matches current lock */
570 if (the_lock.type == type && addr_is_holder(msg->order)) {
571 /* remote daemon missed locked message */
572 send_lockmsg(GRANTED, (pid_t)0, addr, msg->seq);
573 return;
574 }
575
576 /* next search queue to check for duplicate */
577 for (i = 0, lrp = lock_queue; i++ < next_req; lrp++) {
578 if (lrp->type == type && lrp->pid == msg->pid &&
579 cmp_addr(addr, &(lrp->remote)) == 0)
580 return;
581
582 }
583
584 /*
585 * It's a new lock request. Are we in the middle of
586 * obtaining one for ourselves?
587 */
588
589 if (the_lock.type == LOCK_NOTLOCKED && the_lock.state == STATE_ASKED) {
590 /* did a higher priority request just come in? */
591 if (msg->order < order) {
592 /* requeue our request */
593 the_lock.state = STATE_CLEAR;
594 lock_wanted.state = STATE_CLEAR;
595
596 /* let the other lockds know */
597 for (i = 0, ldp = daemon_list; i < MAX_DAEMONS;
598 i++, ldp++) {
599 if (ldp->inuse == 0)
600 break;
601 if (ldp->up && ldp->state == STATE_OKAYED) {
602 send_lockmsg(UNLOCK, (pid_t)0,
603 &(ldp->host), 0);
604 }
605 }
606 }
607 }
608
609
610 lrp = lock_queue;
611 lrp += (next_req++);
612 lrp->type = type;
613 lrp->pid = msg->pid;
614 lrp->state = STATE_CLEAR;
615 lrp->order = msg->order;
616 if (addr) {
617 lrp->remote = *addr;
618 }
619
620 if (next_req > 1)
621 qsort(lock_queue, next_req, sizeof (lock_queue[0]), lock_sort);
622
623 if (the_lock.type != LOCK_WRITE)
624 process_queue();
625 }
626
627 static void
628 lock_stat()
629 {
630 char *lt = "Unknown";
631 struct lockdaemon *ldp;
632 int i;
633
634 switch (the_lock.type) {
635 case LOCK_NOTLOCKED:
636 lt = "not locked";
637 break;
638 case LOCK_READ:
639 lt = "read locked";
640 break;
641 case LOCK_WRITE:
642 lt = "write locked";
643 break;
644 }
645 spcs_log("cfglockd", NULL, "Lock is %s (%d)", lt, the_lock.type);
646 spcs_log("cfglockd", NULL, "There are %d holders of the lock",
647 the_lock.nholders);
648 if (the_lock.nholders > 0) {
649 for (i = 0; i < the_lock.nholders; i++)
650 spcs_log("cfglockd", NULL, "holding_pid[%d] = %6d", i,
651 the_lock.holding_pid[i]);
652 }
653 spcs_log("cfglockd", NULL, "holder daemon was %s port %hu, remote %x",
654 dp_addr(&the_lock.holder), the_lock.holder.sin_port,
655 the_lock.remote_daemon);
656 spcs_log("cfglockd", NULL, "Lock queue, %d requests", next_req);
657 for (i = 0; i < next_req; i++) {
658 spcs_log("cfglockd", NULL, "request %d type %d order %d", i,
659 lock_queue[i].type, lock_queue[i].order);
660 spcs_log("cfglockd", NULL, " client %s port %hu, pid %d",
661 dp_addr(&lock_queue[i].remote),
662 lock_queue[i].remote.sin_port, lock_queue[i].pid);
663 }
664 spcs_log("cfglockd", NULL, "Daemon list");
665
666 for (i = 0, ldp = daemon_list; i < MAX_DAEMONS; i++, ldp++) {
667 if (ldp->inuse == 0)
668 break;
669 spcs_log("cfglockd", NULL, "daemon %d, %s port %hu", i,
670 dp_addr(&ldp->host), ldp->host.sin_port);
671 spcs_log("cfglockd", NULL,
672 " up %d timeout %ld missed %d state %d\n", ldp->up,
673 ldp->timeout, ticker - ldp->timeout, ldp->state);
674 }
675 }
676
677 static int
678 is_duplicate(cfglockd_t type, pid_t pid, uint8_t seq)
679 {
680 struct unlock_s *bufp;
681 int i;
682
683 if (!pid) {
684 return (0);
685 }
686
687 for (i = 0, bufp = unlock_buf; bufp->pid && i < MAX_UNLOCK;
688 i++, bufp++) {
689 if (bufp->pid == pid && bufp->seq == seq) {
690 /* throw message away */
691 #ifdef DEBUG
692 spcs_log("cfglockd", NULL,
693 "duplicate '%d' request received from %d",
694 type, pid);
695 #endif
696 return (1);
697 }
698 }
699
700 /* add it to the list */
701 bcopy(unlock_buf, &unlock_buf[ 1 ],
702 sizeof (unlock_buf) - sizeof (struct unlock_s));
703 (*unlock_buf).pid = pid;
704 (*unlock_buf).seq = seq;
705
706 return (0);
707 }
708
709 static void
710 local_lock(cfglockd_t type, struct lock_msg *msg, daemonaddr_t *client)
711 {
712 if (is_duplicate(type, msg->pid, msg->seq)) {
713 if (the_lock.remote_daemon == NULL &&
714 (the_lock.type == LOCK_WRITE ||
715 the_lock.type == LOCK_READ) &&
716 the_lock.holding_pid[0] == msg->pid) {
717 send_lockmsg(LOCK_LOCKED, (pid_t)0, client, msg->seq);
718 }
719 } else {
720 queue_lock(type, msg, client);
721 }
722 }
723
724 static void
725 remote_lock(struct sockaddr_in *remote, struct lock_msg *msg)
726 {
727 /* make sure remote knows we are alive */
728 send_lockmsg(ALIVE, (pid_t)0, remote, 0);
729
730 /* clear out pid as it is meaningless on this node */
731 msg->pid = (pid_t)0;
732
733 queue_lock(LOCK_WRITE, msg, (daemonaddr_t *)remote);
734 }
735
736 static void
737 unqueue_lock(daemonaddr_t *d, pid_t pid)
738 {
739 int i;
740 struct lock_req *lrp, *xrp;
741 int diff;
742
743 /* search queue to delete ungranted locks */
744 for (i = 0, xrp = lrp = lock_queue; i++ < next_req; lrp++) {
745 *xrp = *lrp;
746 diff = 0;
747 if (pid != (pid_t)0 && lrp->pid != pid)
748 diff = 1;
749 if (d != NULL && cmp_addr(d, &(lrp->remote)) != 0)
750 diff = 1;
751 if (!diff)
752 continue;
753
754 xrp++;
755 }
756 next_req = xrp - lock_queue;
757 }
758
759 static void
760 xxunlock()
761 {
762 DPF((stderr, "** UNLOCK **\n"));
763 the_lock.remote_daemon = NULL;
764 the_lock.type = LOCK_NOTLOCKED;
765 the_lock.nholders = 0;
766 the_lock.state = STATE_CLEAR;
767 process_queue();
768 }
769
770
771 static void
772 local_unlock(pid_t pid, uint8_t seq, int method)
773 {
774 struct lockdaemon *ldp;
775 int i;
776
777 if (method == NORMAL_UNLOCK && is_duplicate(LOCK_NOTLOCKED, pid, seq)) {
778 return;
779 }
780
781 if (the_lock.type == LOCK_READ) {
782 /* delete reference to pid of reading process */
783 for (i = 0; i < the_lock.nholders; i++) {
784 if (the_lock.holding_pid[i] == pid) {
785 DPF((stderr, "decrement lockers from %d\n",
786 the_lock.nholders));
787 --the_lock.nholders;
788 break;
789 }
790 }
791 for (; i < the_lock.nholders; i++) {
792 the_lock.holding_pid[i] = the_lock.holding_pid[i+1];
793 }
794 if (the_lock.nholders > 0)
795 return;
796 } else {
797 /* LOCK_WRITE */
798 if (pid != the_lock.holding_pid[0])
799 return;
800 the_lock.holding_pid[0] = (pid_t)0;
801 for (i = 0, ldp = daemon_list; i < MAX_DAEMONS; i++, ldp++) {
802 if (ldp->inuse == 0)
803 break;
804 if (ldp->up)
805 send_lockmsg(UNLOCK, (pid_t)0, &(ldp->host), 0);
806 }
807 }
808 xxunlock();
809 }
810
811 static void
812 remote_unlock(int32_t order, daemonaddr_t *d)
813 {
814 int i;
815 struct lock_req *lrp;
816
817 DPF((stderr, "remote unlock from %s ", dp_addr(d)));
818 DPF((stderr, "when %s holds lock\n", dp_addr(&the_lock.holder)));
819
820 /* search queue to check for ungranted lock */
821 for (i = 0, lrp = lock_queue; i++ < next_req; lrp++) {
822 if (lrp->type == LOCK_WRITE &&
823 cmp_addr(d, &(lrp->remote)) == 0) {
824 delete_queue_entry(lrp);
825 return;
826 }
827
828 }
829 if (addr_is_holder(order)) {
830 xxunlock();
831 }
832 }
833
834 static void
835 lockedby(daemonaddr_t *d, uint8_t seq)
836 {
837 DPF((stderr, "lockby enquiry from %s ", dp_addr(d)));
838 switch (the_lock.type) {
839 case LOCK_NOTLOCKED:
840 send_lockmsg(LOCK_NOTLOCKED, (pid_t)0, d, seq);
841 break;
842 case LOCK_READ:
843 send_lockmsg(LOCK_READ, the_lock.holding_pid[0], d, seq);
844 break;
845 case LOCK_WRITE:
846 send_lockmsg(LOCK_WRITE, the_lock.holding_pid[0], d, seq);
847 break;
848 }
849 }
850
851 /* ARGSUSED */
852 static void
853 keepalive(int signo)
854 {
855 int i;
856 struct lock_req *locker;
857 struct lockdaemon *ldp;
858
859 DPF((stderr, "keepalive...\n"));
860 ticker++;
861
862 /*
863 * tell any other daemon that has a lock request in our queue that
864 * this daemon is still alive.
865 */
866
867 for (i = 0, locker = lock_queue; i < next_req; i++, locker++) {
868 if (locker->pid == 0) /* remote lock request */
869 send_lockmsg(ALIVE, (pid_t)0, &(locker->remote), 0);
870 }
871
872 /*
873 * if a remote daemon holds the lock, check it is still alive and
874 * if the remote daemon is sent it a grant message in case the
875 * remote daemon missed our original grant.
876 */
877
878 if (the_lock.remote_daemon) {
879 if (lockdaemon_dead(the_lock.remote_daemon)) {
880 DPF((stderr, "lock owner died\n"));
881 the_lock.remote_daemon->up = 0;
882 xxunlock();
883 } else {
884 send_lockmsg(GRANTED, (pid_t)0, &the_lock.holder, 0);
885 }
886 }
887
888 /*
889 * check for response from daemons preventing this daemon
890 * from taking a write lock by not sending a grant message.
891 * if the remote daemon is alive send another lock request,
892 * otherwise mark it as dead.
893 * send alive message to any live remote daemons if this
894 * daemon has the write lock.
895 */
896 if (lstate) {
897 (void) printf("\nlock: %s\n", lockd_type(the_lock.type));
898 (void) printf(" no. holders: %d\n", the_lock.nholders);
899 (void) printf(" hold addr : %s\n", the_lock.remote_daemon?
900 dp_addr(the_lock.remote_daemon): "0.0.0.0");
901 (void) printf(" holding pid:");
902 for (i = 0; i < the_lock.nholders; i++) {
903 (void) printf(" %ld", the_lock.holding_pid[ i ]);
904 }
905 (void) printf("\n");
906 }
907 for (i = 0, ldp = daemon_list; i < MAX_DAEMONS; i++, ldp++) {
908 if (ldp->inuse == 0)
909 break;
910
911 if (lstate) {
912 (void) printf("%-15.15s ", dp_addr(&ldp->host));
913 (void) printf("%-4.4s ", ldp->up? "up" : "down");
914 (void) printf("%5ld ", ldp->timeout);
915 (void) printf("%-10.10s ", lockd_state(ldp->state));
916 (void) printf("%6d\n", ldp->order);
917 }
918
919 if (ldp->state == STATE_ASKED) {
920 if (lockdaemon_dead(ldp)) {
921 ldp->up = 0;
922 ldp->state = STATE_CLEAR;
923 continue;
924 }
925 send_lockmsg(WRITE_LOCK, (pid_t)0, &(ldp->host), 0);
926 continue;
927 }
928 if (the_lock.type == LOCK_WRITE &&
929 the_lock.remote_daemon == NULL)
930 send_lockmsg(ALIVE, (pid_t)0, &(ldp->host), 0);
931 }
932 }
933
934 static void
935 dispatch(struct lock_msg *mp, daemonaddr_t *host)
936 {
937 int message = mp->message;
938 int localhost;
939
940 localhost = islocalhost(host);
941 if (msgtrace && debugfile) {
942 time_t t = time(0);
943 if (localhost) {
944 (void) fprintf(debugfile,
945 "%19.19s recv %-9.9s from %s (%ld)\n", ctime(&t),
946 lockd_msg(message), dp_addr(host), mp->pid);
947 } else {
948 (void) fprintf(debugfile,
949 "%19.19s recv %-9.9s from %s order %d (%ld)\n",
950 ctime(&t), lockd_msg(message), dp_addr(host),
951 mp->order, mp->pid);
952 }
953 }
954 DPF((stderr, "received message %d\n", message));
955 DPF((stderr, "from %s port %hu\n", dp_addr(host), host->sin_port));
956 if (!localhost)
957 daemon_alive(host, mp->order);
958 else
959 mp->order = order;
960 switch (message) {
961 case ALIVE:
962 DPF((stderr, "received ALIVE %s\n", dp_addr(host)));
963 /* do nothing, general "not localhost" code above does this */
964 break;
965 case UNLOCK:
966 DPF((stderr, "received UNLOCK\n"));
967 remote_unlock(mp->order, host);
968 break;
969 case GRANTED:
970 DPF((stderr, "received GRANTED\n"));
971 lock_granted(host);
972 break;
973 case WRITE_LOCK:
974 DPF((stderr, "received WRITE_LOCK\n"));
975 assert(!localhost);
976 remote_lock(host, mp);
977 break;
978 case READ_LOCK:
979 case LOCK_READ:
980 DPF((stderr, "received READ_LOCK\n"));
981 assert(localhost);
982 local_lock(LOCK_READ, mp, host);
983 break;
984 case LOCK_WRITE:
985 DPF((stderr, "received LOCK_WRITE\n"));
986 assert(localhost);
987 local_lock(LOCK_WRITE, mp, host);
988 break;
989 case LOCK_NOTLOCKED:
990 DPF((stderr, "received LOCK_NOTLOCKED\n"));
991 send_lockmsg(LOCK_ACK, (pid_t)0, host, mp->seq);
992 if (the_lock.type != LOCK_NOTLOCKED) {
993 local_unlock(mp->pid, mp->seq, NORMAL_UNLOCK);
994 }
995 break;
996 case LOCK_LOCKEDBY:
997 lockedby(host, mp->seq);
998 break;
999 case LOCK_STAT:
1000 lock_stat();
1001 break;
1002 case LOCK_ACK:
1003 /* throw message away -- this is an error to receive */
1004 break;
1005 }
1006 }
1007
1008 /*
1009 * unqueue any locks asked for by pid and unlock any locks held by pid.
1010 */
1011
1012 static void
1013 purge_pid(pid_t pid)
1014 {
1015 DPF((stderr, "purge locks for %ld\n", pid));
1016 unqueue_lock(NULL, pid);
1017 if (the_lock.type != LOCK_NOTLOCKED)
1018 local_unlock(pid, 0, FORCE_UNLOCK);
1019 }
1020
1021 /*
1022 * Check for exit or exec of client processes.
1023 * The lock protecting the processes pid in the lockfile will
1024 * be removed by the kernel when a client exits or execs.
1025 */
1026
1027 static void
1028 check_for_dead()
1029 {
1030 int i, x;
1031 pid_t pid;
1032
1033 for (i = 0; (x = cfg_filelock(i, 0)) != CFG_LF_EOF; i++) {
1034 if (x == CFG_LF_AGAIN)
1035 continue; /* can't take lock, must be still alive */
1036 cfg_readpid(i, &pid);
1037 cfg_writepid(i, (pid_t)0);
1038 (void) cfg_fileunlock(i);
1039 if (pid != (pid_t)0)
1040 purge_pid(pid);
1041 }
1042 }
1043
1044 static void
1045 build_daemon_list(char *cf_file, int exe)
1046 {
1047 FILE *fp;
1048 char host[1024];
1049 int port;
1050 int i;
1051 struct hostent *hp;
1052 struct lockdaemon *ldp;
1053
1054 if ((hp = gethostbyname("localhost")) == NULL) {
1055 (void) fprintf(stderr, "%s: Can't find hostent for %s\n",
1056 program, "localhost");
1057 spcs_log("cfglockd", NULL, "couldn't find localhost");
1058 exit(1);
1059 }
1060
1061 (void) memcpy(&(localhost.sin_addr.s_addr), *(hp->h_addr_list),
1062 sizeof (localhost.sin_addr));
1063 if (cf_file == NULL) {
1064 (void) endhostent();
1065 return;
1066 }
1067 if (exe) {
1068 if ((fp = popen(cf_file, "r")) == NULL) {
1069 perror(cf_file);
1070 (void) fprintf(stderr,
1071 "%s: Can't open config program\n", program);
1072 spcs_log("cfglockd", NULL, "couldn't read config");
1073 exit(1);
1074 }
1075 } else {
1076 if ((fp = fopen(cf_file, "r")) == NULL) {
1077 perror(cf_file);
1078 (void) fprintf(stderr, "%s: Can't open config file\n",
1079 program);
1080 spcs_log("cfglockd", NULL, "couldn't read config");
1081 exit(1);
1082 }
1083 }
1084 ldp = daemon_list;
1085 while ((i = fscanf(fp, "%s %d\n", host, &port)) != EOF) {
1086 if (host[0] == '#') /* line starting with # are comments */
1087 continue;
1088 if (i == 1) {
1089 port = lock_port;
1090 } else {
1091 if (strcmp(host, "localhost") == 0) {
1092 lock_port = port;
1093 continue;
1094 }
1095 }
1096
1097 if ((hp = gethostbyname(host)) == NULL) {
1098 (void) fprintf(stderr,
1099 "%s: Can't find hostent for %s\n", program, host);
1100 continue;
1101 }
1102
1103 (void) memcpy(&(ldp->host.sin_addr.s_addr), *(hp->h_addr_list),
1104 sizeof (ldp->host.sin_addr));
1105 DPF((stderr, "daemon: %s\t%s\n",
1106 inet_ntoa(ldp->host.sin_addr), hp->h_name));
1107 if (islocalhost(&(ldp->host))) {
1108 DPF((stderr, "is an alias for this host, skipping\n"));
1109 continue;
1110 }
1111 ldp->host.sin_port = htons((short)port);
1112 ldp->host.sin_family = hp->h_addrtype;
1113 ldp->inuse = 1;
1114 ldp->up = 1;
1115 ldp++;
1116 }
1117 if (exe)
1118 (void) pclose(fp);
1119 else
1120 (void) fclose(fp);
1121 (void) endhostent();
1122 }
1123
1124 static void
1125 usage()
1126 {
1127 (void) fprintf(stderr,
1128 gettext("usage: %s [-d] [-f file]|[-e program]\n"), program);
1129 exit(1);
1130 }
1131
1132 static void
1133 unexpected(int sig)
1134 {
1135 spcs_log("cfglockd", NULL, "pid %d unexpected signal %d, ignoring",
1136 getpid(), sig);
1137 }
1138
1139 static void
1140 term(int sig)
1141 {
1142 (void) unlink(CFG_PIDFILE);
1143 spcs_log("cfglockd", NULL, "pid %d terminate on signal %d", getpid(),
1144 sig);
1145 exit(0);
1146 }
1147
1148 static void
1149 init(int argc, char *argv[])
1150 {
1151 #if defined(_SunOS_5_6) || defined(_SunOS_5_7) || defined(_SunOS_5_8)
1152 struct rlimit rl;
1153 #endif
1154 int c, i, x;
1155 int rc;
1156 char *cp = NULL;
1157 struct itimerval tv;
1158 struct timeval tp;
1159 socklen_t len = sizeof (thishost);
1160 int exe = 0;
1161 pid_t pid;
1162 FILE *fp;
1163
1164 lstate = (getenv("LOCKD_STATE") != NULL);
1165 msgtrace = (getenv("LOCKD_MSG") != NULL);
1166
1167 /*
1168 * Fork off a child that becomes the daemon.
1169 */
1170
1171 #ifndef TTY_MESSAGES
1172 if ((rc = fork()) > 0)
1173 exit(0);
1174 else if (rc < 0) {
1175 spcs_log("cfglockd", NULL, "can't fork %d", errno);
1176 (void) fprintf(stderr, gettext("dscfglockd: cannot fork: %s\n"),
1177 strerror(errno));
1178 exit(1);
1179 }
1180 #endif
1181
1182 /*
1183 * In child - become daemon.
1184 */
1185
1186 #if !defined(_SunOS_5_6) && !defined(_SunOS_5_7) && !defined(_SunOS_5_8)
1187 /* use closefrom(3C) from PSARC/2000/193 when possible */
1188 closefrom(CLOSE_FD);
1189 #else
1190 (void) getrlimit(RLIMIT_NOFILE, &rl);
1191 for (i = CLOSE_FD; i < rl.rlim_max; i++)
1192 (void) close(i);
1193 #endif
1194
1195 #ifdef DEBUG
1196 #ifndef TTY_MESSAGES
1197 (void) open("/dev/console", O_WRONLY|O_APPEND);
1198 (void) dup(0);
1199 (void) dup(0);
1200 #endif
1201 #endif
1202 (void) close(0);
1203
1204 if (msgtrace || lstate) {
1205 debugfile = fopen("/var/tmp/dscfglockd.out", "a");
1206 if (debugfile) {
1207 time_t t = time(0);
1208 setbuf(debugfile, (char *)0);
1209 (void) fprintf(debugfile, "%19.19s dscfglockd start\n",
1210 ctime(&t));
1211 }
1212 }
1213
1214 (void) setpgrp();
1215 spcs_log("cfglockd", NULL, "new lock daemon, pid %d", getpid());
1216
1217 /*
1218 * Catch as unexpected all signals apart from SIGTERM.
1219 */
1220
1221 for (i = 1; i < _sys_nsig; i++)
1222 (void) sigset(i, unexpected);
1223 (void) sigset(SIGTERM, term);
1224
1225 for (i = 0; (c = getopt(argc, argv, "df:e:")) != EOF; i++) {
1226 switch (c) {
1227 case 'd':
1228 debug = 1;
1229 break;
1230 case 'e':
1231 exe = 1;
1232 if (cp) {
1233 usage();
1234 }
1235 cp = optarg;
1236 break;
1237 case 'f':
1238 if (cp) {
1239 usage();
1240 }
1241 cp = optarg;
1242 break;
1243 default:
1244 usage();
1245 break;
1246 }
1247 }
1248
1249 ifc = (struct ifconf *)malloc(sizeof (struct ifconf));
1250 if (ifc == NULL) {
1251 perror(CFG_PIDFILE);
1252 DPF((stderr, "Can't open pid file\n"));
1253 exit(1);
1254 }
1255 (void) memset((char *)ifc, 0, sizeof (struct ifconf));
1256 getmyaddrs(ifc);
1257
1258 /*
1259 * if (lockdaemonalive()) {
1260 * (void) fprintf(stderr, "%s: %s\n", program,
1261 * gettext("There is already a live lockdaemon"));
1262 * exit(1);
1263 * }
1264 */
1265 if ((fp = fopen(CFG_PIDFILE, "w")) == NULL) {
1266 perror(CFG_PIDFILE);
1267 DPF((stderr, "Can't open pid file\n"));
1268 exit(1);
1269 }
1270 (void) fprintf(fp, "%ld\n", getpid());
1271 (void) fclose(fp);
1272
1273 /* order should be set to node number within cluster */
1274 order = cfg_iscluster();
1275 cfg_lfinit();
1276
1277 if (!order) {
1278 (void) gettimeofday(&tp, NULL);
1279 srand48(tp.tv_usec);
1280 order = lrand48();
1281 if (debugfile) {
1282 (void) fprintf(debugfile, "WARNING: order number "
1283 "is 0 -- changing randomly to %d\n", order);
1284 }
1285 }
1286 c = 0;
1287 for (i = 0; (x = cfg_filelock(i, 0)) != CFG_LF_EOF; i++) {
1288 if (x == CFG_LF_AGAIN) {
1289 cfg_readpid(i, &pid);
1290 if (c++ == 0)
1291 spcs_log("cfglockd", NULL,
1292 "init .dscfg.lck slot %d pid %d locked",
1293 i, pid);
1294 DPF((stderr, "client process %ld still alive\n", pid));
1295 continue; /* can't take lock, must be still alive */
1296 }
1297 cfg_writepid(i, 0);
1298 (void) cfg_fileunlock(i);
1299 }
1300
1301 tv.it_interval.tv_sec = TIMEOUT_SECS;
1302 tv.it_interval.tv_usec = 0;
1303 tv.it_value = tv.it_interval;
1304
1305 bzero(unlock_buf, sizeof (unlock_buf));
1306 next_q = 0;
1307 build_daemon_list(cp, exe);
1308 if ((lock_soc = socket(pf_inet, SOCK_DGRAM, 0)) < 0) {
1309 (void) fprintf(stderr, "%s: %s\n", program,
1310 gettext("failed to create socket"));
1311 perror("socket");
1312 spcs_log("cfglockd", NULL, "couldn't create socket");
1313 exit(1);
1314 }
1315 thishost.sin_family = AF_INET;
1316 thishost.sin_addr.s_addr = INADDR_ANY;
1317 thishost.sin_port = htons(lock_port);
1318 rc = bind(lock_soc, (struct sockaddr *)&thishost, sizeof (thishost));
1319 if (rc < 0) {
1320 perror("bind");
1321 spcs_log("cfglockd", NULL, "couldn't bind");
1322 exit(1);
1323 }
1324 if (getsockname(lock_soc, (struct sockaddr *)&thishost, &len) < 0)
1325 perror("getsockname");
1326 send_aliveall();
1327 (void) sigset(SIGALRM, keepalive);
1328 (void) setitimer(ITIMER_REAL, &tv, NULL);
1329 /*
1330 * wait 2 time outs before allowing a lock to find if someone else
1331 * currently has the lock.
1332 */
1333 }
1334
1335 #ifdef lint
1336 int
1337 lintmain(int argc, char *argv[])
1338 #else
1339 int
1340 main(int argc, char *argv[])
1341 #endif
1342 {
1343 struct lock_msg message_buf;
1344 daemonaddr_t from;
1345 int addrlen;
1346 int rc;
1347 int x = 1; /* kludge to stop warnings from compiler */
1348
1349 init(argc, argv);
1350 CRIT_BEGIN();
1351 while (x) {
1352 CRIT_END();
1353 addrlen = sizeof (from);
1354 DPF((stderr, "begin recvfrom\n"));
1355 rc = recvfrom(lock_soc, &message_buf, sizeof (message_buf),
1356 0, (struct sockaddr *)&from, &addrlen);
1357 DPF((stderr, "end recvfrom rc = %d\n", rc));
1358 CRIT_BEGIN();
1359 if (rc == sizeof (message_buf))
1360 dispatch(&message_buf, &from);
1361 else
1362 check_for_write_lock();
1363
1364 /* if we own the lock, check to see if the process died */
1365 if (the_lock.type != LOCK_NOTLOCKED &&
1366 the_lock.remote_daemon == NULL)
1367 check_for_dead();
1368 }
1369 CRIT_END();
1370 return (0);
1371 }