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/slab.h>
25 #include <linux/smp.h>
26 #include <linux/smp_lock.h>
27 #include <linux/mutex.h>
28 #include <linux/freezer.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 <net/ip.h>
36 #include <linux/lockd/lockd.h>
37 #include <linux/lockd/sm_inter.h>
38 #include <linux/nfs.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(nlmsvc_ops);
48
49 static DEFINE_MUTEX(nlmsvc_mutex);
50 static unsigned int nlmsvc_users;
51 static pid_t nlmsvc_pid;
52 static struct svc_serv *nlmsvc_serv;
53 int nlmsvc_grace_period;
54 unsigned long nlmsvc_timeout;
55
56 static DECLARE_COMPLETION(lockd_start_done);
57 static DECLARE_WAIT_QUEUE_HEAD(lockd_exit);
58
59 /*
60 * These can be set at insmod time (useful for NFS as root filesystem),
61 * and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003
62 */
63 static unsigned long nlm_grace_period;
64 static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO;
65 static int nlm_udpport, nlm_tcpport;
66 int nsm_use_hostnames = 0;
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 static struct ctl_table_header * nlm_sysctl_table;
78
79 static unsigned long get_lockd_grace_period(void)
80 {
81 /* Note: nlm_timeout should always be nonzero */
82 if (nlm_grace_period)
83 return roundup(nlm_grace_period, nlm_timeout) * HZ;
84 else
85 return nlm_timeout * 5 * HZ;
86 }
87
88 unsigned long get_nfs_grace_period(void)
89 {
90 unsigned long lockdgrace = get_lockd_grace_period();
91 unsigned long nfsdgrace = 0;
92
93 if (nlmsvc_ops)
94 nfsdgrace = nlmsvc_ops->get_grace_period();
95
96 return max(lockdgrace, nfsdgrace);
97 }
98 EXPORT_SYMBOL(get_nfs_grace_period);
99
100 static unsigned long set_grace_period(void)
101 {
102 nlmsvc_grace_period = 1;
103 return get_nfs_grace_period() + jiffies;
104 }
105
106 static inline void clear_grace_period(void)
107 {
108 nlmsvc_grace_period = 0;
109 }
110
111 /*
112 * This is the lockd kernel thread
113 */
114 static void
115 lockd(struct svc_rqst *rqstp)
116 {
117 int err = 0;
118 unsigned long grace_period_expire;
119
120 /* Lock module and set up kernel thread */
121 /* lockd_up is waiting for us to startup, so will
122 * be holding a reference to this module, so it
123 * is safe to just claim another reference
124 */
125 __module_get(THIS_MODULE);
126 lock_kernel();
127
128 /*
129 * Let our maker know we're running.
130 */
131 nlmsvc_pid = current->pid;
132 nlmsvc_serv = rqstp->rq_server;
133 complete(&lockd_start_done);
134
135 daemonize("lockd");
136 set_freezable();
137
138 /* Process request with signals blocked, but allow SIGKILL. */
139 allow_signal(SIGKILL);
140
141 dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
142
143 if (!nlm_timeout)
144 nlm_timeout = LOCKD_DFLT_TIMEO;
145 nlmsvc_timeout = nlm_timeout * HZ;
146
147 grace_period_expire = set_grace_period();
148
149 /*
150 * The main request loop. We don't terminate until the last
151 * NFS mount or NFS daemon has gone away, and we've been sent a
152 * signal, or else another process has taken over our job.
153 */
154 while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) {
155 long timeout = MAX_SCHEDULE_TIMEOUT;
156 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
157
158 if (signalled()) {
159 flush_signals(current);
160 if (nlmsvc_ops) {
161 nlmsvc_invalidate_all();
162 grace_period_expire = set_grace_period();
163 }
164 }
165
166 /*
167 * Retry any blocked locks that have been notified by
168 * the VFS. Don't do this during grace period.
169 * (Theoretically, there shouldn't even be blocked locks
170 * during grace period).
171 */
172 if (!nlmsvc_grace_period) {
173 timeout = nlmsvc_retry_blocked();
174 } else if (time_before(grace_period_expire, jiffies))
175 clear_grace_period();
176
177 /*
178 * Find a socket with data available and call its
179 * recvfrom routine.
180 */
181 err = svc_recv(rqstp, timeout);
182 if (err == -EAGAIN || err == -EINTR)
183 continue;
184 if (err < 0) {
185 printk(KERN_WARNING
186 "lockd: terminating on error %d\n",
187 -err);
188 break;
189 }
190
191 dprintk("lockd: request from %s\n",
192 svc_print_addr(rqstp, buf, sizeof(buf)));
193
194 svc_process(rqstp);
195 }
196
197 flush_signals(current);
198
199 /*
200 * Check whether there's a new lockd process before
201 * shutting down the hosts and clearing the slot.
202 */
203 if (!nlmsvc_pid || current->pid == nlmsvc_pid) {
204 if (nlmsvc_ops)
205 nlmsvc_invalidate_all();
206 nlm_shutdown_hosts();
207 nlmsvc_pid = 0;
208 nlmsvc_serv = NULL;
209 } else
210 printk(KERN_DEBUG
211 "lockd: new process, skipping host shutdown\n");
212 wake_up(&lockd_exit);
213
214 /* Exit the RPC thread */
215 svc_exit_thread(rqstp);
216
217 /* Release module */
218 unlock_kernel();
219 module_put_and_exit(0);
220 }
221
222 /*
223 * Make any sockets that are needed but not present.
224 * If nlm_udpport or nlm_tcpport were set as module
225 * options, make those sockets unconditionally
226 */
227 static int make_socks(struct svc_serv *serv, int proto)
228 {
229 static int warned;
230 struct svc_xprt *xprt;
231 int err = 0;
232
233 if (proto == IPPROTO_UDP || nlm_udpport) {
234 xprt = svc_find_xprt(serv, "udp", 0, 0);
235 if (!xprt)
236 err = svc_create_xprt(serv, "udp", nlm_udpport,
237 SVC_SOCK_DEFAULTS);
238 else
239 svc_xprt_put(xprt);
240 }
241 if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport)) {
242 xprt = svc_find_xprt(serv, "tcp", 0, 0);
243 if (!xprt)
244 err = svc_create_xprt(serv, "tcp", nlm_tcpport,
245 SVC_SOCK_DEFAULTS);
246 else
247 svc_xprt_put(xprt);
248 }
249 if (err >= 0) {
250 warned = 0;
251 err = 0;
252 } else if (warned++ == 0)
253 printk(KERN_WARNING
254 "lockd_up: makesock failed, error=%d\n", err);
255 return err;
256 }
257
258 /*
259 * Bring up the lockd process if it's not already up.
260 */
261 int
262 lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
263 {
264 struct svc_serv * serv;
265 int error = 0;
266
267 mutex_lock(&nlmsvc_mutex);
268 /*
269 * Check whether we're already up and running.
270 */
271 if (nlmsvc_pid) {
272 if (proto)
273 error = make_socks(nlmsvc_serv, proto);
274 goto out;
275 }
276
277 /*
278 * Sanity check: if there's no pid,
279 * we should be the first user ...
280 */
281 if (nlmsvc_users)
282 printk(KERN_WARNING
283 "lockd_up: no pid, %d users??\n", nlmsvc_users);
284
285 error = -ENOMEM;
286 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
287 if (!serv) {
288 printk(KERN_WARNING "lockd_up: create service failed\n");
289 goto out;
290 }
291
292 if ((error = make_socks(serv, proto)) < 0)
293 goto destroy_and_out;
294
295 /*
296 * Create the kernel thread and wait for it to start.
297 */
298 error = svc_create_thread(lockd, serv);
299 if (error) {
300 printk(KERN_WARNING
301 "lockd_up: create thread failed, error=%d\n", error);
302 goto destroy_and_out;
303 }
304 wait_for_completion(&lockd_start_done);
305
306 /*
307 * Note: svc_serv structures have an initial use count of 1,
308 * so we exit through here on both success and failure.
309 */
310 destroy_and_out:
311 svc_destroy(serv);
312 out:
313 if (!error)
314 nlmsvc_users++;
315 mutex_unlock(&nlmsvc_mutex);
316 return error;
317 }
318 EXPORT_SYMBOL(lockd_up);
319
320 /*
321 * Decrement the user count and bring down lockd if we're the last.
322 */
323 void
324 lockd_down(void)
325 {
326 static int warned;
327
328 mutex_lock(&nlmsvc_mutex);
329 if (nlmsvc_users) {
330 if (--nlmsvc_users)
331 goto out;
332 } else
333 printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid);
334
335 if (!nlmsvc_pid) {
336 if (warned++ == 0)
337 printk(KERN_WARNING "lockd_down: no lockd running.\n");
338 goto out;
339 }
340 warned = 0;
341
342 kill_proc(nlmsvc_pid, SIGKILL, 1);
343 /*
344 * Wait for the lockd process to exit, but since we're holding
345 * the lockd semaphore, we can't wait around forever ...
346 */
347 if (wait_event_interruptible_timeout(lockd_exit,
348 nlmsvc_pid == 0, HZ) <= 0) {
349 printk(KERN_WARNING
350 "lockd_down: lockd failed to exit, clearing pid\n");
351 nlmsvc_pid = 0;
352 }
353 out:
354 mutex_unlock(&nlmsvc_mutex);
355 }
356 EXPORT_SYMBOL(lockd_down);
357
358 /*
359 * Sysctl parameters (same as module parameters, different interface).
360 */
361
362 static ctl_table nlm_sysctls[] = {
363 {
364 .ctl_name = CTL_UNNUMBERED,
365 .procname = "nlm_grace_period",
366 .data = &nlm_grace_period,
367 .maxlen = sizeof(unsigned long),
368 .mode = 0644,
369 .proc_handler = &proc_doulongvec_minmax,
370 .extra1 = (unsigned long *) &nlm_grace_period_min,
371 .extra2 = (unsigned long *) &nlm_grace_period_max,
372 },
373 {
374 .ctl_name = CTL_UNNUMBERED,
375 .procname = "nlm_timeout",
376 .data = &nlm_timeout,
377 .maxlen = sizeof(unsigned long),
378 .mode = 0644,
379 .proc_handler = &proc_doulongvec_minmax,
380 .extra1 = (unsigned long *) &nlm_timeout_min,
381 .extra2 = (unsigned long *) &nlm_timeout_max,
382 },
383 {
384 .ctl_name = CTL_UNNUMBERED,
385 .procname = "nlm_udpport",
386 .data = &nlm_udpport,
387 .maxlen = sizeof(int),
388 .mode = 0644,
389 .proc_handler = &proc_dointvec_minmax,
390 .extra1 = (int *) &nlm_port_min,
391 .extra2 = (int *) &nlm_port_max,
392 },
393 {
394 .ctl_name = CTL_UNNUMBERED,
395 .procname = "nlm_tcpport",
396 .data = &nlm_tcpport,
397 .maxlen = sizeof(int),
398 .mode = 0644,
399 .proc_handler = &proc_dointvec_minmax,
400 .extra1 = (int *) &nlm_port_min,
401 .extra2 = (int *) &nlm_port_max,
402 },
403 {
404 .ctl_name = CTL_UNNUMBERED,
405 .procname = "nsm_use_hostnames",
406 .data = &nsm_use_hostnames,
407 .maxlen = sizeof(int),
408 .mode = 0644,
409 .proc_handler = &proc_dointvec,
410 },
411 {
412 .ctl_name = CTL_UNNUMBERED,
413 .procname = "nsm_local_state",
414 .data = &nsm_local_state,
415 .maxlen = sizeof(int),
416 .mode = 0644,
417 .proc_handler = &proc_dointvec,
418 },
419 { .ctl_name = 0 }
420 };
421
422 static ctl_table nlm_sysctl_dir[] = {
423 {
424 .ctl_name = CTL_UNNUMBERED,
425 .procname = "nfs",
426 .mode = 0555,
427 .child = nlm_sysctls,
428 },
429 { .ctl_name = 0 }
430 };
431
432 static ctl_table nlm_sysctl_root[] = {
433 {
434 .ctl_name = CTL_FS,
435 .procname = "fs",
436 .mode = 0555,
437 .child = nlm_sysctl_dir,
438 },
439 { .ctl_name = 0 }
440 };
441
442 /*
443 * Module (and sysfs) parameters.
444 */
445
446 #define param_set_min_max(name, type, which_strtol, min, max) \
447 static int param_set_##name(const char *val, struct kernel_param *kp) \
448 { \
449 char *endp; \
450 __typeof__(type) num = which_strtol(val, &endp, 0); \
451 if (endp == val || *endp || num < (min) || num > (max)) \
452 return -EINVAL; \
453 *((int *) kp->arg) = num; \
454 return 0; \
455 }
456
457 static inline int is_callback(u32 proc)
458 {
459 return proc == NLMPROC_GRANTED
460 || proc == NLMPROC_GRANTED_MSG
461 || proc == NLMPROC_TEST_RES
462 || proc == NLMPROC_LOCK_RES
463 || proc == NLMPROC_CANCEL_RES
464 || proc == NLMPROC_UNLOCK_RES
465 || proc == NLMPROC_NSM_NOTIFY;
466 }
467
468
469 static int lockd_authenticate(struct svc_rqst *rqstp)
470 {
471 rqstp->rq_client = NULL;
472 switch (rqstp->rq_authop->flavour) {
473 case RPC_AUTH_NULL:
474 case RPC_AUTH_UNIX:
475 if (rqstp->rq_proc == 0)
476 return SVC_OK;
477 if (is_callback(rqstp->rq_proc)) {
478 /* Leave it to individual procedures to
479 * call nlmsvc_lookup_host(rqstp)
480 */
481 return SVC_OK;
482 }
483 return svc_set_client(rqstp);
484 }
485 return SVC_DENIED;
486 }
487
488
489 param_set_min_max(port, int, simple_strtol, 0, 65535)
490 param_set_min_max(grace_period, unsigned long, simple_strtoul,
491 nlm_grace_period_min, nlm_grace_period_max)
492 param_set_min_max(timeout, unsigned long, simple_strtoul,
493 nlm_timeout_min, nlm_timeout_max)
494
495 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
496 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
497 MODULE_LICENSE("GPL");
498
499 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
500 &nlm_grace_period, 0644);
501 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
502 &nlm_timeout, 0644);
503 module_param_call(nlm_udpport, param_set_port, param_get_int,
504 &nlm_udpport, 0644);
505 module_param_call(nlm_tcpport, param_set_port, param_get_int,
506 &nlm_tcpport, 0644);
507 module_param(nsm_use_hostnames, bool, 0644);
508
509 /*
510 * Initialising and terminating the module.
511 */
512
513 static int __init init_nlm(void)
514 {
515 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
516 return nlm_sysctl_table ? 0 : -ENOMEM;
517 }
518
519 static void __exit exit_nlm(void)
520 {
521 /* FIXME: delete all NLM clients */
522 nlm_shutdown_hosts();
523 unregister_sysctl_table(nlm_sysctl_table);
524 }
525
526 module_init(init_nlm);
527 module_exit(exit_nlm);
528
529 /*
530 * Define NLM program and procedures
531 */
532 static struct svc_version nlmsvc_version1 = {
533 .vs_vers = 1,
534 .vs_nproc = 17,
535 .vs_proc = nlmsvc_procedures,
536 .vs_xdrsize = NLMSVC_XDRSIZE,
537 };
538 static struct svc_version nlmsvc_version3 = {
539 .vs_vers = 3,
540 .vs_nproc = 24,
541 .vs_proc = nlmsvc_procedures,
542 .vs_xdrsize = NLMSVC_XDRSIZE,
543 };
544 #ifdef CONFIG_LOCKD_V4
545 static struct svc_version nlmsvc_version4 = {
546 .vs_vers = 4,
547 .vs_nproc = 24,
548 .vs_proc = nlmsvc_procedures4,
549 .vs_xdrsize = NLMSVC_XDRSIZE,
550 };
551 #endif
552 static struct svc_version * nlmsvc_version[] = {
553 [1] = &nlmsvc_version1,
554 [3] = &nlmsvc_version3,
555 #ifdef CONFIG_LOCKD_V4
556 [4] = &nlmsvc_version4,
557 #endif
558 };
559
560 static struct svc_stat nlmsvc_stats;
561
562 #define NLM_NRVERS ARRAY_SIZE(nlmsvc_version)
563 static struct svc_program nlmsvc_program = {
564 .pg_prog = NLM_PROGRAM, /* program number */
565 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */
566 .pg_vers = nlmsvc_version, /* version table */
567 .pg_name = "lockd", /* service name */
568 .pg_class = "nfsd", /* share authentication with nfsd */
569 .pg_stats = &nlmsvc_stats, /* stats table */
570 .pg_authenticate = &lockd_authenticate /* export authentication */
571 };
572
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