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