xref: /openbmc/linux/fs/lockd/svc.c (revision f49169c9)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * linux/fs/lockd/svc.c
4  *
5  * This is the central lockd service.
6  *
7  * FIXME: Separate the lockd NFS server functionality from the lockd NFS
8  * 	  client functionality. Oh why didn't Sun create two separate
9  *	  services in the first place?
10  *
11  * Authors:	Olaf Kirch (okir@monad.swb.de)
12  *
13  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
14  */
15 
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/sysctl.h>
19 #include <linux/moduleparam.h>
20 
21 #include <linux/sched/signal.h>
22 #include <linux/errno.h>
23 #include <linux/in.h>
24 #include <linux/uio.h>
25 #include <linux/smp.h>
26 #include <linux/mutex.h>
27 #include <linux/kthread.h>
28 #include <linux/freezer.h>
29 #include <linux/inetdevice.h>
30 
31 #include <linux/sunrpc/types.h>
32 #include <linux/sunrpc/stats.h>
33 #include <linux/sunrpc/clnt.h>
34 #include <linux/sunrpc/svc.h>
35 #include <linux/sunrpc/svcsock.h>
36 #include <linux/sunrpc/svc_xprt.h>
37 #include <net/ip.h>
38 #include <net/addrconf.h>
39 #include <net/ipv6.h>
40 #include <linux/lockd/lockd.h>
41 #include <linux/nfs.h>
42 
43 #include "netns.h"
44 #include "procfs.h"
45 
46 #define NLMDBG_FACILITY		NLMDBG_SVC
47 #define LOCKD_BUFSIZE		(1024 + NLMSVC_XDRSIZE)
48 #define ALLOWED_SIGS		(sigmask(SIGKILL))
49 
50 static struct svc_program	nlmsvc_program;
51 
52 const struct nlmsvc_binding	*nlmsvc_ops;
53 EXPORT_SYMBOL_GPL(nlmsvc_ops);
54 
55 static DEFINE_MUTEX(nlmsvc_mutex);
56 static unsigned int		nlmsvc_users;
57 static struct svc_serv		*nlmsvc_serv;
58 unsigned long			nlmsvc_timeout;
59 
60 unsigned int lockd_net_id;
61 
62 /*
63  * These can be set at insmod time (useful for NFS as root filesystem),
64  * and also changed through the sysctl interface.  -- Jamie Lokier, Aug 2003
65  */
66 static unsigned long		nlm_grace_period;
67 static unsigned long		nlm_timeout = LOCKD_DFLT_TIMEO;
68 static int			nlm_udpport, nlm_tcpport;
69 
70 /* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */
71 static unsigned int		nlm_max_connections = 1024;
72 
73 /*
74  * Constants needed for the sysctl interface.
75  */
76 static const unsigned long	nlm_grace_period_min = 0;
77 static const unsigned long	nlm_grace_period_max = 240;
78 static const unsigned long	nlm_timeout_min = 3;
79 static const unsigned long	nlm_timeout_max = 20;
80 static const int		nlm_port_min = 0, nlm_port_max = 65535;
81 
82 #ifdef CONFIG_SYSCTL
83 static struct ctl_table_header * nlm_sysctl_table;
84 #endif
85 
86 static unsigned long get_lockd_grace_period(void)
87 {
88 	/* Note: nlm_timeout should always be nonzero */
89 	if (nlm_grace_period)
90 		return roundup(nlm_grace_period, nlm_timeout) * HZ;
91 	else
92 		return nlm_timeout * 5 * HZ;
93 }
94 
95 static void grace_ender(struct work_struct *grace)
96 {
97 	struct delayed_work *dwork = to_delayed_work(grace);
98 	struct lockd_net *ln = container_of(dwork, struct lockd_net,
99 					    grace_period_end);
100 
101 	locks_end_grace(&ln->lockd_manager);
102 }
103 
104 static void set_grace_period(struct net *net)
105 {
106 	unsigned long grace_period = get_lockd_grace_period();
107 	struct lockd_net *ln = net_generic(net, lockd_net_id);
108 
109 	locks_start_grace(net, &ln->lockd_manager);
110 	cancel_delayed_work_sync(&ln->grace_period_end);
111 	schedule_delayed_work(&ln->grace_period_end, grace_period);
112 }
113 
114 static void restart_grace(void)
115 {
116 	if (nlmsvc_ops) {
117 		struct net *net = &init_net;
118 		struct lockd_net *ln = net_generic(net, lockd_net_id);
119 
120 		cancel_delayed_work_sync(&ln->grace_period_end);
121 		locks_end_grace(&ln->lockd_manager);
122 		nlmsvc_invalidate_all();
123 		set_grace_period(net);
124 	}
125 }
126 
127 /*
128  * This is the lockd kernel thread
129  */
130 static int
131 lockd(void *vrqstp)
132 {
133 	int		err = 0;
134 	struct svc_rqst *rqstp = vrqstp;
135 	struct net *net = &init_net;
136 	struct lockd_net *ln = net_generic(net, lockd_net_id);
137 
138 	/* try_to_freeze() is called from svc_recv() */
139 	set_freezable();
140 
141 	/* Allow SIGKILL to tell lockd to drop all of its locks */
142 	allow_signal(SIGKILL);
143 
144 	dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
145 
146 	/*
147 	 * The main request loop. We don't terminate until the last
148 	 * NFS mount or NFS daemon has gone away.
149 	 */
150 	while (!kthread_should_stop()) {
151 		long timeout = MAX_SCHEDULE_TIMEOUT;
152 		RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
153 
154 		/* update sv_maxconn if it has changed */
155 		rqstp->rq_server->sv_maxconn = nlm_max_connections;
156 
157 		if (signalled()) {
158 			flush_signals(current);
159 			restart_grace();
160 			continue;
161 		}
162 
163 		timeout = nlmsvc_retry_blocked();
164 
165 		/*
166 		 * Find a socket with data available and call its
167 		 * recvfrom routine.
168 		 */
169 		err = svc_recv(rqstp, timeout);
170 		if (err == -EAGAIN || err == -EINTR)
171 			continue;
172 		dprintk("lockd: request from %s\n",
173 				svc_print_addr(rqstp, buf, sizeof(buf)));
174 
175 		svc_process(rqstp);
176 	}
177 	flush_signals(current);
178 	if (nlmsvc_ops)
179 		nlmsvc_invalidate_all();
180 	nlm_shutdown_hosts();
181 	cancel_delayed_work_sync(&ln->grace_period_end);
182 	locks_end_grace(&ln->lockd_manager);
183 
184 	dprintk("lockd_down: service stopped\n");
185 
186 	svc_exit_thread(rqstp);
187 	return 0;
188 }
189 
190 static int create_lockd_listener(struct svc_serv *serv, const char *name,
191 				 struct net *net, const int family,
192 				 const unsigned short port,
193 				 const struct cred *cred)
194 {
195 	struct svc_xprt *xprt;
196 
197 	xprt = svc_find_xprt(serv, name, net, family, 0);
198 	if (xprt == NULL)
199 		return svc_xprt_create(serv, name, net, family, port,
200 				       SVC_SOCK_DEFAULTS, cred);
201 	svc_xprt_put(xprt);
202 	return 0;
203 }
204 
205 static int create_lockd_family(struct svc_serv *serv, struct net *net,
206 			       const int family, const struct cred *cred)
207 {
208 	int err;
209 
210 	err = create_lockd_listener(serv, "udp", net, family, nlm_udpport,
211 			cred);
212 	if (err < 0)
213 		return err;
214 
215 	return create_lockd_listener(serv, "tcp", net, family, nlm_tcpport,
216 			cred);
217 }
218 
219 /*
220  * Ensure there are active UDP and TCP listeners for lockd.
221  *
222  * Even if we have only TCP NFS mounts and/or TCP NFSDs, some
223  * local services (such as rpc.statd) still require UDP, and
224  * some NFS servers do not yet support NLM over TCP.
225  *
226  * Returns zero if all listeners are available; otherwise a
227  * negative errno value is returned.
228  */
229 static int make_socks(struct svc_serv *serv, struct net *net,
230 		const struct cred *cred)
231 {
232 	static int warned;
233 	int err;
234 
235 	err = create_lockd_family(serv, net, PF_INET, cred);
236 	if (err < 0)
237 		goto out_err;
238 
239 	err = create_lockd_family(serv, net, PF_INET6, cred);
240 	if (err < 0 && err != -EAFNOSUPPORT)
241 		goto out_err;
242 
243 	warned = 0;
244 	return 0;
245 
246 out_err:
247 	if (warned++ == 0)
248 		printk(KERN_WARNING
249 			"lockd_up: makesock failed, error=%d\n", err);
250 	svc_xprt_destroy_all(serv, net);
251 	svc_rpcb_cleanup(serv, net);
252 	return err;
253 }
254 
255 static int lockd_up_net(struct svc_serv *serv, struct net *net,
256 		const struct cred *cred)
257 {
258 	struct lockd_net *ln = net_generic(net, lockd_net_id);
259 	int error;
260 
261 	if (ln->nlmsvc_users++)
262 		return 0;
263 
264 	error = svc_bind(serv, net);
265 	if (error)
266 		goto err_bind;
267 
268 	error = make_socks(serv, net, cred);
269 	if (error < 0)
270 		goto err_bind;
271 	set_grace_period(net);
272 	dprintk("%s: per-net data created; net=%x\n", __func__, net->ns.inum);
273 	return 0;
274 
275 err_bind:
276 	ln->nlmsvc_users--;
277 	return error;
278 }
279 
280 static void lockd_down_net(struct svc_serv *serv, struct net *net)
281 {
282 	struct lockd_net *ln = net_generic(net, lockd_net_id);
283 
284 	if (ln->nlmsvc_users) {
285 		if (--ln->nlmsvc_users == 0) {
286 			nlm_shutdown_hosts_net(net);
287 			cancel_delayed_work_sync(&ln->grace_period_end);
288 			locks_end_grace(&ln->lockd_manager);
289 			svc_xprt_destroy_all(serv, net);
290 			svc_rpcb_cleanup(serv, net);
291 		}
292 	} else {
293 		pr_err("%s: no users! net=%x\n",
294 			__func__, net->ns.inum);
295 		BUG();
296 	}
297 }
298 
299 static int lockd_inetaddr_event(struct notifier_block *this,
300 	unsigned long event, void *ptr)
301 {
302 	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
303 	struct sockaddr_in sin;
304 
305 	if (event != NETDEV_DOWN)
306 		goto out;
307 
308 	if (nlmsvc_serv) {
309 		dprintk("lockd_inetaddr_event: removed %pI4\n",
310 			&ifa->ifa_local);
311 		sin.sin_family = AF_INET;
312 		sin.sin_addr.s_addr = ifa->ifa_local;
313 		svc_age_temp_xprts_now(nlmsvc_serv, (struct sockaddr *)&sin);
314 	}
315 
316 out:
317 	return NOTIFY_DONE;
318 }
319 
320 static struct notifier_block lockd_inetaddr_notifier = {
321 	.notifier_call = lockd_inetaddr_event,
322 };
323 
324 #if IS_ENABLED(CONFIG_IPV6)
325 static int lockd_inet6addr_event(struct notifier_block *this,
326 	unsigned long event, void *ptr)
327 {
328 	struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
329 	struct sockaddr_in6 sin6;
330 
331 	if (event != NETDEV_DOWN)
332 		goto out;
333 
334 	if (nlmsvc_serv) {
335 		dprintk("lockd_inet6addr_event: removed %pI6\n", &ifa->addr);
336 		sin6.sin6_family = AF_INET6;
337 		sin6.sin6_addr = ifa->addr;
338 		if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
339 			sin6.sin6_scope_id = ifa->idev->dev->ifindex;
340 		svc_age_temp_xprts_now(nlmsvc_serv, (struct sockaddr *)&sin6);
341 	}
342 
343 out:
344 	return NOTIFY_DONE;
345 }
346 
347 static struct notifier_block lockd_inet6addr_notifier = {
348 	.notifier_call = lockd_inet6addr_event,
349 };
350 #endif
351 
352 static const struct svc_serv_ops lockd_sv_ops = {
353 	.svo_function		= lockd,
354 };
355 
356 static int lockd_get(void)
357 {
358 	struct svc_serv *serv;
359 	int error;
360 
361 	if (nlmsvc_serv) {
362 		svc_get(nlmsvc_serv);
363 		nlmsvc_users++;
364 		return 0;
365 	}
366 
367 	/*
368 	 * Sanity check: if there's no pid,
369 	 * we should be the first user ...
370 	 */
371 	if (nlmsvc_users)
372 		printk(KERN_WARNING
373 			"lockd_up: no pid, %d users??\n", nlmsvc_users);
374 
375 	if (!nlm_timeout)
376 		nlm_timeout = LOCKD_DFLT_TIMEO;
377 	nlmsvc_timeout = nlm_timeout * HZ;
378 
379 	serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, &lockd_sv_ops);
380 	if (!serv) {
381 		printk(KERN_WARNING "lockd_up: create service failed\n");
382 		return -ENOMEM;
383 	}
384 
385 	serv->sv_maxconn = nlm_max_connections;
386 	error = svc_set_num_threads(serv, NULL, 1);
387 	/* The thread now holds the only reference */
388 	svc_put(serv);
389 	if (error < 0)
390 		return error;
391 
392 	nlmsvc_serv = serv;
393 	register_inetaddr_notifier(&lockd_inetaddr_notifier);
394 #if IS_ENABLED(CONFIG_IPV6)
395 	register_inet6addr_notifier(&lockd_inet6addr_notifier);
396 #endif
397 	dprintk("lockd_up: service created\n");
398 	nlmsvc_users++;
399 	return 0;
400 }
401 
402 static void lockd_put(void)
403 {
404 	if (WARN(nlmsvc_users <= 0, "lockd_down: no users!\n"))
405 		return;
406 	if (--nlmsvc_users)
407 		return;
408 
409 	unregister_inetaddr_notifier(&lockd_inetaddr_notifier);
410 #if IS_ENABLED(CONFIG_IPV6)
411 	unregister_inet6addr_notifier(&lockd_inet6addr_notifier);
412 #endif
413 
414 	svc_set_num_threads(nlmsvc_serv, NULL, 0);
415 	nlmsvc_serv = NULL;
416 	dprintk("lockd_down: service destroyed\n");
417 }
418 
419 /*
420  * Bring up the lockd process if it's not already up.
421  */
422 int lockd_up(struct net *net, const struct cred *cred)
423 {
424 	int error;
425 
426 	mutex_lock(&nlmsvc_mutex);
427 
428 	error = lockd_get();
429 	if (error)
430 		goto err;
431 
432 	error = lockd_up_net(nlmsvc_serv, net, cred);
433 	if (error < 0) {
434 		lockd_put();
435 		goto err;
436 	}
437 
438 err:
439 	mutex_unlock(&nlmsvc_mutex);
440 	return error;
441 }
442 EXPORT_SYMBOL_GPL(lockd_up);
443 
444 /*
445  * Decrement the user count and bring down lockd if we're the last.
446  */
447 void
448 lockd_down(struct net *net)
449 {
450 	mutex_lock(&nlmsvc_mutex);
451 	lockd_down_net(nlmsvc_serv, net);
452 	lockd_put();
453 	mutex_unlock(&nlmsvc_mutex);
454 }
455 EXPORT_SYMBOL_GPL(lockd_down);
456 
457 #ifdef CONFIG_SYSCTL
458 
459 /*
460  * Sysctl parameters (same as module parameters, different interface).
461  */
462 
463 static struct ctl_table nlm_sysctls[] = {
464 	{
465 		.procname	= "nlm_grace_period",
466 		.data		= &nlm_grace_period,
467 		.maxlen		= sizeof(unsigned long),
468 		.mode		= 0644,
469 		.proc_handler	= proc_doulongvec_minmax,
470 		.extra1		= (unsigned long *) &nlm_grace_period_min,
471 		.extra2		= (unsigned long *) &nlm_grace_period_max,
472 	},
473 	{
474 		.procname	= "nlm_timeout",
475 		.data		= &nlm_timeout,
476 		.maxlen		= sizeof(unsigned long),
477 		.mode		= 0644,
478 		.proc_handler	= proc_doulongvec_minmax,
479 		.extra1		= (unsigned long *) &nlm_timeout_min,
480 		.extra2		= (unsigned long *) &nlm_timeout_max,
481 	},
482 	{
483 		.procname	= "nlm_udpport",
484 		.data		= &nlm_udpport,
485 		.maxlen		= sizeof(int),
486 		.mode		= 0644,
487 		.proc_handler	= proc_dointvec_minmax,
488 		.extra1		= (int *) &nlm_port_min,
489 		.extra2		= (int *) &nlm_port_max,
490 	},
491 	{
492 		.procname	= "nlm_tcpport",
493 		.data		= &nlm_tcpport,
494 		.maxlen		= sizeof(int),
495 		.mode		= 0644,
496 		.proc_handler	= proc_dointvec_minmax,
497 		.extra1		= (int *) &nlm_port_min,
498 		.extra2		= (int *) &nlm_port_max,
499 	},
500 	{
501 		.procname	= "nsm_use_hostnames",
502 		.data		= &nsm_use_hostnames,
503 		.maxlen		= sizeof(int),
504 		.mode		= 0644,
505 		.proc_handler	= proc_dobool,
506 	},
507 	{
508 		.procname	= "nsm_local_state",
509 		.data		= &nsm_local_state,
510 		.maxlen		= sizeof(int),
511 		.mode		= 0644,
512 		.proc_handler	= proc_dointvec,
513 	},
514 	{ }
515 };
516 
517 static struct ctl_table nlm_sysctl_dir[] = {
518 	{
519 		.procname	= "nfs",
520 		.mode		= 0555,
521 		.child		= nlm_sysctls,
522 	},
523 	{ }
524 };
525 
526 static struct ctl_table nlm_sysctl_root[] = {
527 	{
528 		.procname	= "fs",
529 		.mode		= 0555,
530 		.child		= nlm_sysctl_dir,
531 	},
532 	{ }
533 };
534 
535 #endif	/* CONFIG_SYSCTL */
536 
537 /*
538  * Module (and sysfs) parameters.
539  */
540 
541 #define param_set_min_max(name, type, which_strtol, min, max)		\
542 static int param_set_##name(const char *val, const struct kernel_param *kp) \
543 {									\
544 	char *endp;							\
545 	__typeof__(type) num = which_strtol(val, &endp, 0);		\
546 	if (endp == val || *endp || num < (min) || num > (max))		\
547 		return -EINVAL;						\
548 	*((type *) kp->arg) = num;					\
549 	return 0;							\
550 }
551 
552 static inline int is_callback(u32 proc)
553 {
554 	return proc == NLMPROC_GRANTED
555 		|| proc == NLMPROC_GRANTED_MSG
556 		|| proc == NLMPROC_TEST_RES
557 		|| proc == NLMPROC_LOCK_RES
558 		|| proc == NLMPROC_CANCEL_RES
559 		|| proc == NLMPROC_UNLOCK_RES
560 		|| proc == NLMPROC_NSM_NOTIFY;
561 }
562 
563 
564 static int lockd_authenticate(struct svc_rqst *rqstp)
565 {
566 	rqstp->rq_client = NULL;
567 	switch (rqstp->rq_authop->flavour) {
568 		case RPC_AUTH_NULL:
569 		case RPC_AUTH_UNIX:
570 			rqstp->rq_auth_stat = rpc_auth_ok;
571 			if (rqstp->rq_proc == 0)
572 				return SVC_OK;
573 			if (is_callback(rqstp->rq_proc)) {
574 				/* Leave it to individual procedures to
575 				 * call nlmsvc_lookup_host(rqstp)
576 				 */
577 				return SVC_OK;
578 			}
579 			return svc_set_client(rqstp);
580 	}
581 	rqstp->rq_auth_stat = rpc_autherr_badcred;
582 	return SVC_DENIED;
583 }
584 
585 
586 param_set_min_max(port, int, simple_strtol, 0, 65535)
587 param_set_min_max(grace_period, unsigned long, simple_strtoul,
588 		  nlm_grace_period_min, nlm_grace_period_max)
589 param_set_min_max(timeout, unsigned long, simple_strtoul,
590 		  nlm_timeout_min, nlm_timeout_max)
591 
592 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
593 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
594 MODULE_LICENSE("GPL");
595 
596 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
597 		  &nlm_grace_period, 0644);
598 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
599 		  &nlm_timeout, 0644);
600 module_param_call(nlm_udpport, param_set_port, param_get_int,
601 		  &nlm_udpport, 0644);
602 module_param_call(nlm_tcpport, param_set_port, param_get_int,
603 		  &nlm_tcpport, 0644);
604 module_param(nsm_use_hostnames, bool, 0644);
605 module_param(nlm_max_connections, uint, 0644);
606 
607 static int lockd_init_net(struct net *net)
608 {
609 	struct lockd_net *ln = net_generic(net, lockd_net_id);
610 
611 	INIT_DELAYED_WORK(&ln->grace_period_end, grace_ender);
612 	INIT_LIST_HEAD(&ln->lockd_manager.list);
613 	ln->lockd_manager.block_opens = false;
614 	INIT_LIST_HEAD(&ln->nsm_handles);
615 	return 0;
616 }
617 
618 static void lockd_exit_net(struct net *net)
619 {
620 	struct lockd_net *ln = net_generic(net, lockd_net_id);
621 
622 	WARN_ONCE(!list_empty(&ln->lockd_manager.list),
623 		  "net %x %s: lockd_manager.list is not empty\n",
624 		  net->ns.inum, __func__);
625 	WARN_ONCE(!list_empty(&ln->nsm_handles),
626 		  "net %x %s: nsm_handles list is not empty\n",
627 		  net->ns.inum, __func__);
628 	WARN_ONCE(delayed_work_pending(&ln->grace_period_end),
629 		  "net %x %s: grace_period_end was not cancelled\n",
630 		  net->ns.inum, __func__);
631 }
632 
633 static struct pernet_operations lockd_net_ops = {
634 	.init = lockd_init_net,
635 	.exit = lockd_exit_net,
636 	.id = &lockd_net_id,
637 	.size = sizeof(struct lockd_net),
638 };
639 
640 
641 /*
642  * Initialising and terminating the module.
643  */
644 
645 static int __init init_nlm(void)
646 {
647 	int err;
648 
649 #ifdef CONFIG_SYSCTL
650 	err = -ENOMEM;
651 	nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
652 	if (nlm_sysctl_table == NULL)
653 		goto err_sysctl;
654 #endif
655 	err = register_pernet_subsys(&lockd_net_ops);
656 	if (err)
657 		goto err_pernet;
658 
659 	err = lockd_create_procfs();
660 	if (err)
661 		goto err_procfs;
662 
663 	return 0;
664 
665 err_procfs:
666 	unregister_pernet_subsys(&lockd_net_ops);
667 err_pernet:
668 #ifdef CONFIG_SYSCTL
669 	unregister_sysctl_table(nlm_sysctl_table);
670 err_sysctl:
671 #endif
672 	return err;
673 }
674 
675 static void __exit exit_nlm(void)
676 {
677 	/* FIXME: delete all NLM clients */
678 	nlm_shutdown_hosts();
679 	lockd_remove_procfs();
680 	unregister_pernet_subsys(&lockd_net_ops);
681 #ifdef CONFIG_SYSCTL
682 	unregister_sysctl_table(nlm_sysctl_table);
683 #endif
684 }
685 
686 module_init(init_nlm);
687 module_exit(exit_nlm);
688 
689 /**
690  * nlmsvc_dispatch - Process an NLM Request
691  * @rqstp: incoming request
692  * @statp: pointer to location of accept_stat field in RPC Reply buffer
693  *
694  * Return values:
695  *  %0: Processing complete; do not send a Reply
696  *  %1: Processing complete; send Reply in rqstp->rq_res
697  */
698 static int nlmsvc_dispatch(struct svc_rqst *rqstp, __be32 *statp)
699 {
700 	const struct svc_procedure *procp = rqstp->rq_procinfo;
701 
702 	svcxdr_init_decode(rqstp);
703 	if (!procp->pc_decode(rqstp, &rqstp->rq_arg_stream))
704 		goto out_decode_err;
705 
706 	*statp = procp->pc_func(rqstp);
707 	if (*statp == rpc_drop_reply)
708 		return 0;
709 	if (*statp != rpc_success)
710 		return 1;
711 
712 	svcxdr_init_encode(rqstp);
713 	if (!procp->pc_encode(rqstp, &rqstp->rq_res_stream))
714 		goto out_encode_err;
715 
716 	return 1;
717 
718 out_decode_err:
719 	*statp = rpc_garbage_args;
720 	return 1;
721 
722 out_encode_err:
723 	*statp = rpc_system_err;
724 	return 1;
725 }
726 
727 /*
728  * Define NLM program and procedures
729  */
730 static unsigned int nlmsvc_version1_count[17];
731 static const struct svc_version	nlmsvc_version1 = {
732 	.vs_vers	= 1,
733 	.vs_nproc	= 17,
734 	.vs_proc	= nlmsvc_procedures,
735 	.vs_count	= nlmsvc_version1_count,
736 	.vs_dispatch	= nlmsvc_dispatch,
737 	.vs_xdrsize	= NLMSVC_XDRSIZE,
738 };
739 static unsigned int nlmsvc_version3_count[24];
740 static const struct svc_version	nlmsvc_version3 = {
741 	.vs_vers	= 3,
742 	.vs_nproc	= 24,
743 	.vs_proc	= nlmsvc_procedures,
744 	.vs_count	= nlmsvc_version3_count,
745 	.vs_dispatch	= nlmsvc_dispatch,
746 	.vs_xdrsize	= NLMSVC_XDRSIZE,
747 };
748 #ifdef CONFIG_LOCKD_V4
749 static unsigned int nlmsvc_version4_count[24];
750 static const struct svc_version	nlmsvc_version4 = {
751 	.vs_vers	= 4,
752 	.vs_nproc	= 24,
753 	.vs_proc	= nlmsvc_procedures4,
754 	.vs_count	= nlmsvc_version4_count,
755 	.vs_dispatch	= nlmsvc_dispatch,
756 	.vs_xdrsize	= NLMSVC_XDRSIZE,
757 };
758 #endif
759 static const struct svc_version *nlmsvc_version[] = {
760 	[1] = &nlmsvc_version1,
761 	[3] = &nlmsvc_version3,
762 #ifdef CONFIG_LOCKD_V4
763 	[4] = &nlmsvc_version4,
764 #endif
765 };
766 
767 static struct svc_stat		nlmsvc_stats;
768 
769 #define NLM_NRVERS	ARRAY_SIZE(nlmsvc_version)
770 static struct svc_program	nlmsvc_program = {
771 	.pg_prog		= NLM_PROGRAM,		/* program number */
772 	.pg_nvers		= NLM_NRVERS,		/* number of entries in nlmsvc_version */
773 	.pg_vers		= nlmsvc_version,	/* version table */
774 	.pg_name		= "lockd",		/* service name */
775 	.pg_class		= "nfsd",		/* share authentication with nfsd */
776 	.pg_stats		= &nlmsvc_stats,	/* stats table */
777 	.pg_authenticate	= &lockd_authenticate,	/* export authentication */
778 	.pg_init_request	= svc_generic_init_request,
779 	.pg_rpcbind_set		= svc_generic_rpcbind_set,
780 };
781