xref: /illumos-gate/usr/src/cmd/fs.d/nfs/nfsd/nfsd.c (revision dd51520e127b452179a2ce4ea3bd8dee949f9afe)
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 (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 
25 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T		*/
26 /*	  All Rights Reserved  	*/
27 
28 /*
29  * University Copyright- Copyright (c) 1982, 1986, 1988
30  * The Regents of the University of California
31  * All Rights Reserved
32  *
33  * University Acknowledgment- Portions of this document are derived from
34  * software developed by the University of California, Berkeley, and its
35  * contributors.
36  */
37 
38 /* LINTLIBRARY */
39 /* PROTOLIB1 */
40 
41 /* NFS server */
42 
43 #include <sys/param.h>
44 #include <sys/types.h>
45 #include <sys/stat.h>
46 #include <syslog.h>
47 #include <tiuser.h>
48 #include <rpc/rpc.h>
49 #include <errno.h>
50 #include <thread.h>
51 #include <sys/resource.h>
52 #include <sys/time.h>
53 #include <sys/file.h>
54 #include <nfs/nfs.h>
55 #include <nfs/nfs_acl.h>
56 #include <nfs/nfssys.h>
57 #include <stdio.h>
58 #include <stdio_ext.h>
59 #include <stdlib.h>
60 #include <signal.h>
61 #include <netconfig.h>
62 #include <netdir.h>
63 #include <string.h>
64 #include <unistd.h>
65 #include <limits.h>
66 #include <stropts.h>
67 #include <sys/tihdr.h>
68 #include <sys/wait.h>
69 #include <poll.h>
70 #include <priv_utils.h>
71 #include <sys/tiuser.h>
72 #include <netinet/tcp.h>
73 #include <deflt.h>
74 #include <rpcsvc/daemon_utils.h>
75 #include <rpcsvc/nfs4_prot.h>
76 #include <libnvpair.h>
77 #include <libscf.h>
78 #include <libshare.h>
79 #include "nfs_tbind.h"
80 #include "thrpool.h"
81 #include "smfcfg.h"
82 
83 /* quiesce requests will be ignored if nfs_server_vers_max < QUIESCE_VERSMIN */
84 #define	QUIESCE_VERSMIN	4
85 /* DSS: distributed stable storage */
86 #define	DSS_VERSMIN	4
87 
88 static	int	nfssvc(int, struct netbuf, struct netconfig *);
89 static	int	nfssvcpool(int maxservers);
90 static	int	dss_init(uint_t npaths, char **pathnames);
91 static	void	dss_mkleafdirs(uint_t npaths, char **pathnames);
92 static	void	dss_mkleafdir(char *dir, char *leaf, char *path);
93 static	void	usage(void);
94 int		qstrcmp(const void *s1, const void *s2);
95 
96 extern	int	_nfssys(int, void *);
97 
98 extern int	daemonize_init(void);
99 extern void	daemonize_fini(int fd);
100 
101 /* signal handlers */
102 static void sigflush(int);
103 static void quiesce(int);
104 
105 static	char	*MyName;
106 static	NETSELDECL(defaultproviders)[] = { "/dev/tcp6", "/dev/tcp", "/dev/udp",
107 					    "/dev/udp6", NULL };
108 /* static	NETSELDECL(defaultprotos)[] =	{ NC_UDP, NC_TCP, NULL }; */
109 /*
110  * The following are all globals used by routines in nfs_tbind.c.
111  */
112 size_t	end_listen_fds;		/* used by conn_close_oldest() */
113 size_t	num_fds = 0;		/* used by multiple routines */
114 int	listen_backlog = 32;	/* used by bind_to_{provider,proto}() */
115 int	num_servers;		/* used by cots_listen_event() */
116 int	(*Mysvc)(int, struct netbuf, struct netconfig *) = nfssvc;
117 				/* used by cots_listen_event() */
118 int	max_conns_allowed = -1;	/* used by cots_listen_event() */
119 
120 /*
121  * Keep track of min/max versions of NFS protocol to be started.
122  * Start with the defaults (min == 2, max == 3).  We have the
123  * capability of starting vers=4 but only if the user requests it.
124  */
125 int	nfs_server_vers_min = NFS_VERSMIN_DEFAULT;
126 int	nfs_server_vers_max = NFS_VERSMAX_DEFAULT;
127 
128 /*
129  * Set the default for server delegation enablement and set per
130  * /etc/default/nfs configuration (if present).
131  */
132 int	nfs_server_delegation = NFS_SERVER_DELEGATION_DEFAULT;
133 
134 int
135 main(int ac, char *av[])
136 {
137 	char *dir = "/";
138 	int allflag = 0;
139 	int df_allflag = 0;
140 	int opt_cnt = 0;
141 	int maxservers = 1;	/* zero allows inifinte number of threads */
142 	int maxservers_set = 0;
143 	int logmaxservers = 0;
144 	int pid;
145 	int i;
146 	char *provider = (char *)NULL;
147 	char *df_provider = (char *)NULL;
148 	struct protob *protobp0, *protobp;
149 	NETSELDECL(proto) = NULL;
150 	NETSELDECL(df_proto) = NULL;
151 	NETSELPDECL(providerp);
152 	char *defval;
153 	boolean_t can_do_mlp;
154 	uint_t dss_npaths = 0;
155 	char **dss_pathnames = NULL;
156 	sigset_t sgset;
157 	char name[PATH_MAX], value[PATH_MAX];
158 	int ret, bufsz;
159 
160 	int pipe_fd = -1;
161 
162 	MyName = *av;
163 
164 	/*
165 	 * Initializations that require more privileges than we need to run.
166 	 */
167 	(void) _create_daemon_lock(NFSD, DAEMON_UID, DAEMON_GID);
168 	svcsetprio();
169 
170 	can_do_mlp = priv_ineffect(PRIV_NET_BINDMLP);
171 	if (__init_daemon_priv(PU_RESETGROUPS|PU_CLEARLIMITSET,
172 	    DAEMON_UID, DAEMON_GID, PRIV_SYS_NFS,
173 	    can_do_mlp ? PRIV_NET_BINDMLP : NULL, NULL) == -1) {
174 		(void) fprintf(stderr, "%s should be run with"
175 		    " sufficient privileges\n", av[0]);
176 		exit(1);
177 	}
178 
179 	(void) enable_extended_FILE_stdio(-1, -1);
180 
181 	/*
182 	 * Read in the values from SMF first before we check
183 	 * command line options so the options override SMF values.
184 	 */
185 	bufsz = PATH_MAX;
186 	ret = nfs_smf_get_prop("max_connections", value, DEFAULT_INSTANCE,
187 	    SCF_TYPE_INTEGER, NFSD, &bufsz);
188 	if (ret == SA_OK) {
189 		errno = 0;
190 		max_conns_allowed = strtol(value, (char **)NULL, 10);
191 		if (errno != 0)
192 			max_conns_allowed = -1;
193 	}
194 
195 	bufsz = PATH_MAX;
196 	ret = nfs_smf_get_prop("listen_backlog", value, DEFAULT_INSTANCE,
197 	    SCF_TYPE_INTEGER, NFSD, &bufsz);
198 	if (ret == SA_OK) {
199 		errno = 0;
200 		listen_backlog = strtol(value, (char **)NULL, 10);
201 		if (errno != 0) {
202 			listen_backlog = 32;
203 		}
204 	}
205 
206 	bufsz = PATH_MAX;
207 	ret = nfs_smf_get_prop("protocol", value, DEFAULT_INSTANCE,
208 	    SCF_TYPE_ASTRING, NFSD, &bufsz);
209 	if ((ret == SA_OK) && strlen(value) > 0) {
210 		df_proto = strdup(value);
211 		opt_cnt++;
212 		if (strncasecmp("ALL", value, 3) == 0) {
213 			free(df_proto);
214 			df_proto = NULL;
215 			df_allflag = 1;
216 		}
217 	}
218 
219 	bufsz = PATH_MAX;
220 	ret = nfs_smf_get_prop("device", value, DEFAULT_INSTANCE,
221 	    SCF_TYPE_ASTRING, NFSD, &bufsz);
222 	if ((ret == SA_OK) && strlen(value) > 0) {
223 		df_provider = strdup(value);
224 		opt_cnt++;
225 	}
226 
227 	bufsz = PATH_MAX;
228 	ret = nfs_smf_get_prop("servers", value, DEFAULT_INSTANCE,
229 	    SCF_TYPE_INTEGER, NFSD, &bufsz);
230 	if (ret == SA_OK) {
231 		errno = 0;
232 		maxservers = strtol(value, (char **)NULL, 10);
233 		if (errno != 0)
234 			maxservers = 1;
235 		else
236 			maxservers_set = 1;
237 	}
238 
239 	bufsz = 4;
240 	ret = nfs_smf_get_prop("server_versmin", value, DEFAULT_INSTANCE,
241 	    SCF_TYPE_INTEGER, NFSD, &bufsz);
242 	if (ret == SA_OK)
243 		nfs_server_vers_min = strtol(value, (char **)NULL, 10);
244 
245 	bufsz = 4;
246 	ret = nfs_smf_get_prop("server_versmax", value, DEFAULT_INSTANCE,
247 	    SCF_TYPE_INTEGER, NFSD, &bufsz);
248 	if (ret == SA_OK)
249 		nfs_server_vers_max = strtol(value, (char **)NULL, 10);
250 
251 	bufsz = PATH_MAX;
252 	ret = nfs_smf_get_prop("server_delegation", value, DEFAULT_INSTANCE,
253 	    SCF_TYPE_ASTRING, NFSD, &bufsz);
254 	if (ret == SA_OK)
255 		if (strncasecmp(value, "off", 3) == 0)
256 			nfs_server_delegation = FALSE;
257 
258 	/*
259 	 * Conflict options error messages.
260 	 */
261 	if (opt_cnt > 1) {
262 		(void) fprintf(stderr, "\nConflicting options, only one of "
263 		    "the following options can be specified\n"
264 		    "in SMF:\n"
265 		    "\tprotocol=ALL\n"
266 		    "\tprotocol=protocol\n"
267 		    "\tdevice=devicename\n\n");
268 		usage();
269 	}
270 	opt_cnt = 0;
271 
272 	while ((i = getopt(ac, av, "ac:p:s:t:l:")) != EOF) {
273 		switch (i) {
274 		case 'a':
275 			free(df_proto);
276 			df_proto = NULL;
277 			free(df_provider);
278 			df_provider = NULL;
279 
280 			allflag = 1;
281 			opt_cnt++;
282 			break;
283 
284 		case 'c':
285 			max_conns_allowed = atoi(optarg);
286 			break;
287 
288 		case 'p':
289 			proto = optarg;
290 			df_allflag = 0;
291 			opt_cnt++;
292 			break;
293 
294 		/*
295 		 * DSS: NFSv4 distributed stable storage.
296 		 *
297 		 * This is a Contracted Project Private interface, for
298 		 * the sole use of Sun Cluster HA-NFS. See PSARC/2006/313.
299 		 */
300 		case 's':
301 			if (strlen(optarg) < MAXPATHLEN) {
302 				/* first "-s" option encountered? */
303 				if (dss_pathnames == NULL) {
304 					/*
305 					 * Allocate maximum possible space
306 					 * required given cmdline arg count;
307 					 * "-s <path>" consumes two args.
308 					 */
309 					size_t sz = (ac / 2) * sizeof (char *);
310 					dss_pathnames = (char **)malloc(sz);
311 					if (dss_pathnames == NULL) {
312 						(void) fprintf(stderr, "%s: "
313 						    "dss paths malloc failed\n",
314 						    av[0]);
315 						exit(1);
316 					}
317 					(void) memset(dss_pathnames, 0, sz);
318 				}
319 				dss_pathnames[dss_npaths] = optarg;
320 				dss_npaths++;
321 			} else {
322 				(void) fprintf(stderr,
323 				    "%s: -s pathname too long.\n", av[0]);
324 			}
325 			break;
326 
327 		case 't':
328 			provider = optarg;
329 			df_allflag = 0;
330 			opt_cnt++;
331 			break;
332 
333 		case 'l':
334 			listen_backlog = atoi(optarg);
335 			break;
336 
337 		case '?':
338 			usage();
339 			/* NOTREACHED */
340 		}
341 	}
342 
343 	allflag = df_allflag;
344 	if (proto == NULL)
345 		proto = df_proto;
346 	if (provider == NULL)
347 		provider = df_provider;
348 
349 	/*
350 	 * Conflict options error messages.
351 	 */
352 	if (opt_cnt > 1) {
353 		(void) fprintf(stderr, "\nConflicting options, only one of "
354 		    "the following options can be specified\n"
355 		    "on the command line:\n"
356 		    "\t-a\n"
357 		    "\t-p protocol\n"
358 		    "\t-t transport\n\n");
359 		usage();
360 	}
361 
362 	if (proto != NULL &&
363 	    strncasecmp(proto, NC_UDP, strlen(NC_UDP)) == 0) {
364 		if (nfs_server_vers_max == NFS_V4) {
365 			if (nfs_server_vers_min == NFS_V4) {
366 				fprintf(stderr,
367 				    "NFS version 4 is not supported "
368 				    "with the UDP protocol.  Exiting\n");
369 				exit(3);
370 			} else {
371 				fprintf(stderr,
372 				    "NFS version 4 is not supported "
373 				    "with the UDP protocol.\n");
374 			}
375 		}
376 	}
377 
378 	/*
379 	 * If there is exactly one more argument, it is the number of
380 	 * servers.
381 	 */
382 	if (optind == ac - 1) {
383 		maxservers = atoi(av[optind]);
384 		maxservers_set = 1;
385 	}
386 	/*
387 	 * If there are two or more arguments, then this is a usage error.
388 	 */
389 	else if (optind < ac - 1)
390 		usage();
391 	/*
392 	 * Check the ranges for min/max version specified
393 	 */
394 	else if ((nfs_server_vers_min > nfs_server_vers_max) ||
395 	    (nfs_server_vers_min < NFS_VERSMIN) ||
396 	    (nfs_server_vers_max > NFS_VERSMAX))
397 		usage();
398 	/*
399 	 * There are no additional arguments, and we haven't set maxservers
400 	 * explicitly via the config file, we use a default number of
401 	 * servers.  We will log this.
402 	 */
403 	else if (maxservers_set == 0)
404 		logmaxservers = 1;
405 
406 	/*
407 	 * Basic Sanity checks on options
408 	 *
409 	 * max_conns_allowed must be positive, except for the special
410 	 * value of -1 which is used internally to mean unlimited, -1 isn't
411 	 * documented but we allow it anyway.
412 	 *
413 	 * maxservers must be positive
414 	 * listen_backlog must be positive or zero
415 	 */
416 	if (((max_conns_allowed != -1) && (max_conns_allowed <= 0)) ||
417 	    (listen_backlog < 0) || (maxservers <= 0)) {
418 		usage();
419 	}
420 
421 	/*
422 	 * Set current dir to server root
423 	 */
424 	if (chdir(dir) < 0) {
425 		(void) fprintf(stderr, "%s:  ", MyName);
426 		perror(dir);
427 		exit(1);
428 	}
429 
430 #ifndef DEBUG
431 	pipe_fd = daemonize_init();
432 #endif
433 
434 	openlog(MyName, LOG_PID | LOG_NDELAY, LOG_DAEMON);
435 
436 	/*
437 	 * establish our lock on the lock file and write our pid to it.
438 	 * exit if some other process holds the lock, or if there's any
439 	 * error in writing/locking the file.
440 	 */
441 	pid = _enter_daemon_lock(NFSD);
442 	switch (pid) {
443 	case 0:
444 		break;
445 	case -1:
446 		fprintf(stderr, "error locking for %s: %s", NFSD,
447 		    strerror(errno));
448 		exit(2);
449 	default:
450 		/* daemon was already running */
451 		exit(0);
452 	}
453 
454 	/*
455 	 * If we've been given a list of paths to be used for distributed
456 	 * stable storage, and provided we're going to run a version
457 	 * that supports it, setup the DSS paths.
458 	 */
459 	if (dss_pathnames != NULL && nfs_server_vers_max >= DSS_VERSMIN) {
460 		if (dss_init(dss_npaths, dss_pathnames) != 0) {
461 			fprintf(stderr, "%s", "dss_init failed. Exiting.");
462 			exit(1);
463 		}
464 	}
465 
466 	/*
467 	 * Block all signals till we spawn other
468 	 * threads.
469 	 */
470 	(void) sigfillset(&sgset);
471 	(void) thr_sigsetmask(SIG_BLOCK, &sgset, NULL);
472 
473 	if (logmaxservers) {
474 		fprintf(stderr,
475 		    "Number of servers not specified. Using default of %d.",
476 		    maxservers);
477 	}
478 
479 	/*
480 	 * Make sure to unregister any previous versions in case the
481 	 * user is reconfiguring the server in interesting ways.
482 	 */
483 	svc_unreg(NFS_PROGRAM, NFS_VERSION);
484 	svc_unreg(NFS_PROGRAM, NFS_V3);
485 	svc_unreg(NFS_PROGRAM, NFS_V4);
486 	svc_unreg(NFS_ACL_PROGRAM, NFS_ACL_V2);
487 	svc_unreg(NFS_ACL_PROGRAM, NFS_ACL_V3);
488 
489 	/*
490 	 * Set up kernel RPC thread pool for the NFS server.
491 	 */
492 	if (nfssvcpool(maxservers)) {
493 		fprintf(stderr, "Can't set up kernel NFS service: %s. Exiting",
494 		    strerror(errno));
495 		exit(1);
496 	}
497 
498 	/*
499 	 * Set up blocked thread to do LWP creation on behalf of the kernel.
500 	 */
501 	if (svcwait(NFS_SVCPOOL_ID)) {
502 		fprintf(stderr, "Can't set up NFS pool creator: %s. Exiting",
503 		    strerror(errno));
504 		exit(1);
505 	}
506 
507 	/*
508 	 * RDMA start and stop thread.
509 	 * Per pool RDMA listener creation and
510 	 * destructor thread.
511 	 *
512 	 * start rdma services and block in the kernel.
513 	 * (only if proto or provider is not set to TCP or UDP)
514 	 */
515 	if ((proto == NULL) && (provider == NULL)) {
516 		if (svcrdma(NFS_SVCPOOL_ID, nfs_server_vers_min,
517 		    nfs_server_vers_max, nfs_server_delegation)) {
518 			fprintf(stderr,
519 			    "Can't set up RDMA creator thread : %s",
520 			    strerror(errno));
521 		}
522 	}
523 
524 	/*
525 	 * Now open up for signal delivery
526 	 */
527 
528 	(void) thr_sigsetmask(SIG_UNBLOCK, &sgset, NULL);
529 	sigset(SIGTERM, sigflush);
530 	sigset(SIGUSR1, quiesce);
531 
532 	/*
533 	 * Build a protocol block list for registration.
534 	 */
535 	protobp0 = protobp = (struct protob *)malloc(sizeof (struct protob));
536 	protobp->serv = "NFS";
537 	protobp->versmin = nfs_server_vers_min;
538 	protobp->versmax = nfs_server_vers_max;
539 	protobp->program = NFS_PROGRAM;
540 
541 	protobp->next = (struct protob *)malloc(sizeof (struct protob));
542 	protobp = protobp->next;
543 	protobp->serv = "NFS_ACL";		/* not used */
544 	protobp->versmin = nfs_server_vers_min;
545 	/* XXX - this needs work to get the version just right */
546 	protobp->versmax = (nfs_server_vers_max > NFS_ACL_V3) ?
547 	    NFS_ACL_V3 : nfs_server_vers_max;
548 	protobp->program = NFS_ACL_PROGRAM;
549 	protobp->next = (struct protob *)NULL;
550 
551 	if (allflag) {
552 		if (do_all(protobp0, nfssvc) == -1) {
553 			fprintf(stderr, "setnetconfig failed : %s",
554 			    strerror(errno));
555 			exit(1);
556 		}
557 	} else if (proto) {
558 		/* there's more than one match for the same protocol */
559 		struct netconfig *nconf;
560 		NCONF_HANDLE *nc;
561 		bool_t	protoFound = FALSE;
562 		if ((nc = setnetconfig()) == (NCONF_HANDLE *) NULL) {
563 			fprintf(stderr, "setnetconfig failed : %s",
564 			    strerror(errno));
565 			goto done;
566 		}
567 		while (nconf = getnetconfig(nc)) {
568 			if (strcmp(nconf->nc_proto, proto) == 0) {
569 				protoFound = TRUE;
570 				do_one(nconf->nc_device, NULL,
571 				    protobp0, nfssvc);
572 			}
573 		}
574 		(void) endnetconfig(nc);
575 		if (protoFound == FALSE) {
576 			fprintf(stderr,
577 			    "couldn't find netconfig entry for protocol %s",
578 			    proto);
579 		}
580 	} else if (provider)
581 		do_one(provider, proto, protobp0, nfssvc);
582 	else {
583 		for (providerp = defaultproviders;
584 		    *providerp != NULL; providerp++) {
585 			provider = *providerp;
586 			do_one(provider, NULL, protobp0, nfssvc);
587 		}
588 	}
589 done:
590 
591 	free(protobp);
592 	free(protobp0);
593 
594 	if (num_fds == 0) {
595 		fprintf(stderr, "Could not start NFS service for any protocol."
596 		    " Exiting");
597 		exit(1);
598 	}
599 
600 	end_listen_fds = num_fds;
601 
602 	/*
603 	 * nfsd is up and running as far as we are concerned.
604 	 */
605 	daemonize_fini(pipe_fd);
606 
607 	/*
608 	 * Get rid of unneeded privileges.
609 	 */
610 	__fini_daemon_priv(PRIV_PROC_FORK, PRIV_PROC_EXEC, PRIV_PROC_SESSION,
611 	    PRIV_FILE_LINK_ANY, PRIV_PROC_INFO, (char *)NULL);
612 
613 	/*
614 	 * Poll for non-data control events on the transport descriptors.
615 	 */
616 	poll_for_action();
617 
618 	/*
619 	 * If we get here, something failed in poll_for_action().
620 	 */
621 	return (1);
622 }
623 
624 static int
625 nfssvcpool(int maxservers)
626 {
627 	struct svcpool_args npa;
628 
629 	npa.id = NFS_SVCPOOL_ID;
630 	npa.maxthreads = maxservers;
631 	npa.redline = 0;
632 	npa.qsize = 0;
633 	npa.timeout = 0;
634 	npa.stksize = 0;
635 	npa.max_same_xprt = 0;
636 	return (_nfssys(SVCPOOL_CREATE, &npa));
637 }
638 
639 /*
640  * Establish NFS service thread.
641  */
642 static int
643 nfssvc(int fd, struct netbuf addrmask, struct netconfig *nconf)
644 {
645 	struct nfs_svc_args nsa;
646 
647 	nsa.fd = fd;
648 	nsa.netid = nconf->nc_netid;
649 	nsa.addrmask = addrmask;
650 	if (strncasecmp(nconf->nc_proto, NC_UDP, strlen(NC_UDP)) == 0) {
651 		nsa.versmax = (nfs_server_vers_max > NFS_V3) ?
652 		    NFS_V3 : nfs_server_vers_max;
653 		nsa.versmin = nfs_server_vers_min;
654 		/*
655 		 * If no version left, silently do nothing, previous
656 		 * checks will have assured at least TCP is available.
657 		 */
658 		if (nsa.versmin > nsa.versmax)
659 			return (0);
660 	} else {
661 		nsa.versmax = nfs_server_vers_max;
662 		nsa.versmin = nfs_server_vers_min;
663 	}
664 	nsa.delegation = nfs_server_delegation;
665 	return (_nfssys(NFS_SVC, &nsa));
666 }
667 
668 static void
669 usage(void)
670 {
671 	(void) fprintf(stderr,
672 "usage: %s [ -a ] [ -c max_conns ] [ -p protocol ] [ -t transport ] ", MyName);
673 	(void) fprintf(stderr, "\n[ -l listen_backlog ] [ nservers ]\n");
674 	(void) fprintf(stderr,
675 "\twhere -a causes <nservers> to be started on each appropriate transport,\n");
676 	(void) fprintf(stderr,
677 "\tmax_conns is the maximum number of concurrent connections allowed,\n");
678 	(void) fprintf(stderr, "\t\tand max_conns must be a decimal number");
679 	(void) fprintf(stderr, "> zero,\n");
680 	(void) fprintf(stderr, "\tprotocol is a protocol identifier,\n");
681 	(void) fprintf(stderr,
682 	    "\ttransport is a transport provider name (i.e. device),\n");
683 	(void) fprintf(stderr,
684 	    "\tlisten_backlog is the TCP listen backlog,\n");
685 	(void) fprintf(stderr,
686 	    "\tand <nservers> must be a decimal number > zero.\n");
687 	exit(1);
688 }
689 
690 /*
691  * Issue nfssys system call to flush all logging buffers asynchronously.
692  *
693  * NOTICE: It is extremely important to flush NFS logging buffers when
694  *	   nfsd exits. When the system is halted or rebooted nfslogd
695  *	   may not have an opportunity to flush the buffers.
696  */
697 static void
698 nfsl_flush()
699 {
700 	struct nfsl_flush_args nfa;
701 
702 	memset((void *)&nfa, 0, sizeof (nfa));
703 	nfa.version = NFSL_FLUSH_ARGS_VERS;
704 	nfa.directive = NFSL_ALL;	/* flush all asynchronously */
705 
706 	if (_nfssys(LOG_FLUSH, &nfa) < 0)
707 		syslog(LOG_ERR, "_nfssys(LOG_FLUSH) failed: %s\n",
708 		    strerror(errno));
709 }
710 
711 /*
712  * SIGTERM handler.
713  * Flush logging buffers and exit.
714  */
715 static void
716 sigflush(int sig)
717 {
718 	nfsl_flush();
719 	_exit(0);
720 }
721 
722 /*
723  * SIGUSR1 handler.
724  *
725  * Request that server quiesce, then (nfsd) exit. For subsequent warm start.
726  *
727  * This is a Contracted Project Private interface, for the sole use
728  * of Sun Cluster HA-NFS. See PSARC/2004/497.
729  *
730  * Equivalent to SIGTERM handler if nfs_server_vers_max < QUIESCE_VERSMIN.
731  */
732 static void
733 quiesce(int sig)
734 {
735 	int error;
736 	int id = NFS_SVCPOOL_ID;
737 
738 	if (nfs_server_vers_max >= QUIESCE_VERSMIN) {
739 		/* Request server quiesce at next shutdown */
740 		error = _nfssys(NFS4_SVC_REQUEST_QUIESCE, &id);
741 
742 		/*
743 		 * ENOENT is returned if there is no matching SVC pool
744 		 * for the id. Possibly because the pool is not yet setup.
745 		 * In this case, just exit as if no error. For all other errors,
746 		 * just return and allow caller to retry.
747 		 */
748 		if (error && errno != ENOENT) {
749 			syslog(LOG_ERR,
750 			    "_nfssys(NFS4_SVC_REQUEST_QUIESCE) failed: %s",
751 			    strerror(errno));
752 			return;
753 		}
754 	}
755 
756 	/* Flush logging buffers */
757 	nfsl_flush();
758 
759 	_exit(0);
760 }
761 
762 /*
763  * DSS: distributed stable storage.
764  * Create leaf directories as required, keeping an eye on path
765  * lengths. Calls exit(1) on failure.
766  * The pathnames passed in must already exist, and must be writeable by nfsd.
767  * Note: the leaf directories under NFS4_VAR_DIR are not created here;
768  * they're created at pkg install.
769  */
770 static void
771 dss_mkleafdirs(uint_t npaths, char **pathnames)
772 {
773 	int i;
774 	char *tmppath = NULL;
775 
776 	/*
777 	 * Create the temporary storage used by dss_mkleafdir() here,
778 	 * rather than in that function, so that it only needs to be
779 	 * done once, rather than once for each call. Too big to put
780 	 * on the function's stack.
781 	 */
782 	tmppath = (char *)malloc(MAXPATHLEN);
783 	if (tmppath == NULL) {
784 		syslog(LOG_ERR, "tmppath malloc failed. Exiting");
785 		exit(1);
786 	}
787 
788 	for (i = 0; i < npaths; i++) {
789 		char *p = pathnames[i];
790 
791 		dss_mkleafdir(p, NFS4_DSS_STATE_LEAF, tmppath);
792 		dss_mkleafdir(p, NFS4_DSS_OLDSTATE_LEAF, tmppath);
793 	}
794 
795 	free(tmppath);
796 }
797 
798 /*
799  * Create "leaf" in "dir" (which must already exist).
800  * leaf: should start with a '/'
801  */
802 static void
803 dss_mkleafdir(char *dir, char *leaf, char *tmppath)
804 {
805 	/* MAXPATHLEN includes the terminating NUL */
806 	if (strlen(dir) + strlen(leaf) > MAXPATHLEN - 1) {
807 		fprintf(stderr, "stable storage path too long: %s%s. Exiting",
808 		    dir, leaf);
809 		exit(1);
810 	}
811 
812 	(void) snprintf(tmppath, MAXPATHLEN, "%s/%s", dir, leaf);
813 
814 	/* the directory may already exist: that's OK */
815 	if (mkdir(tmppath, NFS4_DSS_DIR_MODE) == -1 && errno != EEXIST) {
816 		fprintf(stderr, "error creating stable storage directory: "
817 		    "%s: %s. Exiting", strerror(errno), tmppath);
818 		exit(1);
819 	}
820 }
821 
822 /*
823  * Create the storage dirs, and pass the path list to the kernel.
824  * This requires the nfssrv module to be loaded; the _nfssys() syscall
825  * will fail ENOTSUP if it is not.
826  * Use libnvpair(3LIB) to pass the data to the kernel.
827  */
828 static int
829 dss_init(uint_t npaths, char **pathnames)
830 {
831 	int i, j, nskipped, error;
832 	char *bufp;
833 	uint32_t bufsize;
834 	size_t buflen;
835 	nvlist_t *nvl;
836 
837 	if (npaths > 1) {
838 		/*
839 		 * We need to remove duplicate paths; this might be user error
840 		 * in the general case, but HA-NFSv4 can also cause this.
841 		 * Sort the pathnames array, and NULL out duplicates,
842 		 * then write the non-NULL entries to a new array.
843 		 * Sorting will also allow the kernel to optimise its searches.
844 		 */
845 
846 		qsort(pathnames, npaths, sizeof (char *), qstrcmp);
847 
848 		/* now NULL out any duplicates */
849 		i = 0; j = 1; nskipped = 0;
850 		while (j < npaths) {
851 			if (strcmp(pathnames[i], pathnames[j]) == NULL) {
852 				pathnames[j] = NULL;
853 				j++;
854 				nskipped++;
855 				continue;
856 			}
857 
858 			/* skip i over any of its NULLed duplicates */
859 			i = j++;
860 		}
861 
862 		/* finally, write the non-NULL entries to a new array */
863 		if (nskipped > 0) {
864 			int nreal;
865 			size_t sz;
866 			char **tmp_pathnames;
867 
868 			nreal = npaths - nskipped;
869 
870 			sz = nreal * sizeof (char *);
871 			tmp_pathnames = (char **)malloc(sz);
872 			if (tmp_pathnames == NULL) {
873 				fprintf(stderr, "tmp_pathnames malloc failed");
874 				exit(1);
875 			}
876 
877 			for (i = 0, j = 0; i < npaths; i++)
878 				if (pathnames[i] != NULL)
879 					tmp_pathnames[j++] = pathnames[i];
880 			free(pathnames);
881 			pathnames = tmp_pathnames;
882 			npaths = nreal;
883 		}
884 
885 	}
886 
887 	/* Create directories to store the distributed state files */
888 	dss_mkleafdirs(npaths, pathnames);
889 
890 	/* Create the name-value pair list */
891 	error = nvlist_alloc(&nvl, NV_UNIQUE_NAME, 0);
892 	if (error) {
893 		fprintf(stderr, "nvlist_alloc failed: %s.", strerror(errno));
894 		return (1);
895 	}
896 
897 	/* Add the pathnames array as a single name-value pair */
898 	error = nvlist_add_string_array(nvl, NFS4_DSS_NVPAIR_NAME,
899 	    pathnames, npaths);
900 	if (error) {
901 		fprintf(stderr, "nvlist_add_string_array failed: %s.",
902 		    strerror(errno));
903 		nvlist_free(nvl);
904 		return (1);
905 	}
906 
907 	/*
908 	 * Pack list into contiguous memory, for passing to kernel.
909 	 * nvlist_pack() will allocate the memory for the buffer,
910 	 * which we should free() when no longer needed.
911 	 * NV_ENCODE_XDR for safety across ILP32/LP64 kernel boundary.
912 	 */
913 	bufp = NULL;
914 	error = nvlist_pack(nvl, &bufp, &buflen, NV_ENCODE_XDR, 0);
915 	if (error) {
916 		fprintf(stderr, "nvlist_pack failed: %s.", strerror(errno));
917 		nvlist_free(nvl);
918 		return (1);
919 	}
920 
921 	/* Now we have the packed buffer, we no longer need the list */
922 	nvlist_free(nvl);
923 
924 	/*
925 	 * Let the kernel know in advance how big the buffer is.
926 	 * NOTE: we cannot just pass buflen, since size_t is a long, and
927 	 * thus a different size between ILP32 userland and LP64 kernel.
928 	 * Use an int for the transfer, since that should be big enough;
929 	 * this is a no-op at the moment, here, since nfsd is 32-bit, but
930 	 * that could change.
931 	 */
932 	bufsize = (uint32_t)buflen;
933 	error = _nfssys(NFS4_DSS_SETPATHS_SIZE, &bufsize);
934 	if (error) {
935 		fprintf(stderr,
936 		    "_nfssys(NFS4_DSS_SETPATHS_SIZE) failed: %s. ",
937 		    strerror(errno));
938 		free(bufp);
939 		return (1);
940 	}
941 
942 	/* Pass the packed buffer to the kernel */
943 	error = _nfssys(NFS4_DSS_SETPATHS, bufp);
944 	if (error) {
945 		fprintf(stderr,
946 		    "_nfssys(NFS4_DSS_SETPATHS) failed: %s. ", strerror(errno));
947 		free(bufp);
948 		return (1);
949 	}
950 
951 	/*
952 	 * The kernel has now unpacked the buffer and extracted the
953 	 * pathnames array, we no longer need the buffer.
954 	 */
955 	free(bufp);
956 
957 	return (0);
958 }
959 
960 /*
961  * Quick sort string compare routine, for qsort.
962  * Needed to make arg types correct.
963  */
964 int
965 qstrcmp(const void *p1, const void *p2)
966 {
967 	char *s1 = *((char **)p1);
968 	char *s2 = *((char **)p2);
969 
970 	return (strcmp(s1, s2));
971 }
972