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