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

source code of linux/fs/lockd/svc.c