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
45static struct svc_program	nlmsvc_program;
46
47struct nlmsvc_binding *		nlmsvc_ops;
48EXPORT_SYMBOL_GPL(nlmsvc_ops);
49
50static DEFINE_MUTEX(nlmsvc_mutex);
51static unsigned int		nlmsvc_users;
52static struct task_struct	*nlmsvc_task;
53static struct svc_rqst		*nlmsvc_rqst;
54unsigned long			nlmsvc_timeout;
55
56int 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 */
62static unsigned long		nlm_grace_period;
63static unsigned long		nlm_timeout = LOCKD_DFLT_TIMEO;
64static int			nlm_udpport, nlm_tcpport;
65
66/* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */
67static unsigned int		nlm_max_connections = 1024;
68
69/*
70 * Constants needed for the sysctl interface.
71 */
72static const unsigned long	nlm_grace_period_min = 0;
73static const unsigned long	nlm_grace_period_max = 240;
74static const unsigned long	nlm_timeout_min = 3;
75static const unsigned long	nlm_timeout_max = 20;
76static const int		nlm_port_min = 0, nlm_port_max = 65535;
77
78#ifdef CONFIG_SYSCTL
79static struct ctl_table_header * nlm_sysctl_table;
80#endif
81
82static 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
91static 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
101static 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
111static 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 */
127static int
128lockd(void *vrqstp)
129{
130	int		err = 0;
131	struct svc_rqst *rqstp = vrqstp;
132
133	/* try_to_freeze() is called from svc_recv() */
134	set_freezable();
135
136	/* Allow SIGKILL to tell lockd to drop all of its locks */
137	allow_signal(SIGKILL);
138
139	dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
140
141	if (!nlm_timeout)
142		nlm_timeout = LOCKD_DFLT_TIMEO;
143	nlmsvc_timeout = nlm_timeout * HZ;
144
145	/*
146	 * The main request loop. We don't terminate until the last
147	 * NFS mount or NFS daemon has gone away.
148	 */
149	while (!kthread_should_stop()) {
150		long timeout = MAX_SCHEDULE_TIMEOUT;
151		RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
152
153		/* update sv_maxconn if it has changed */
154		rqstp->rq_server->sv_maxconn = nlm_max_connections;
155
156		if (signalled()) {
157			flush_signals(current);
158			restart_grace();
159			continue;
160		}
161
162		timeout = nlmsvc_retry_blocked();
163
164		/*
165		 * Find a socket with data available and call its
166		 * recvfrom routine.
167		 */
168		err = svc_recv(rqstp, timeout);
169		if (err == -EAGAIN || err == -EINTR)
170			continue;
171		dprintk("lockd: request from %s\n",
172				svc_print_addr(rqstp, buf, sizeof(buf)));
173
174		svc_process(rqstp);
175	}
176	flush_signals(current);
177	if (nlmsvc_ops)
178		nlmsvc_invalidate_all();
179	nlm_shutdown_hosts();
180	return 0;
181}
182
183static 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
197static 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 */
219static 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
235out_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
243static 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
262err_bind:
263	ln->nlmsvc_users--;
264	return error;
265}
266
267static 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
286static 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
321out_task:
322	svc_exit_thread(nlmsvc_rqst);
323	nlmsvc_task = NULL;
324out_rqst:
325	nlmsvc_rqst = NULL;
326	return error;
327}
328
329static struct svc_serv *lockd_create_svc(void)
330{
331	struct svc_serv *serv;
332
333	/*
334	 * Check whether we're already up and running.
335	 */
336	if (nlmsvc_rqst) {
337		/*
338		 * Note: increase service usage, because later in case of error
339		 * svc_destroy() will be called.
340		 */
341		svc_get(nlmsvc_rqst->rq_server);
342		return nlmsvc_rqst->rq_server;
343	}
344
345	/*
346	 * Sanity check: if there's no pid,
347	 * we should be the first user ...
348	 */
349	if (nlmsvc_users)
350		printk(KERN_WARNING
351			"lockd_up: no pid, %d users??\n", nlmsvc_users);
352
353	serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
354	if (!serv) {
355		printk(KERN_WARNING "lockd_up: create service failed\n");
356		return ERR_PTR(-ENOMEM);
357	}
358	dprintk("lockd_up: service created\n");
359	return serv;
360}
361
362/*
363 * Bring up the lockd process if it's not already up.
364 */
365int lockd_up(struct net *net)
366{
367	struct svc_serv *serv;
368	int error;
369
370	mutex_lock(&nlmsvc_mutex);
371
372	serv = lockd_create_svc();
373	if (IS_ERR(serv)) {
374		error = PTR_ERR(serv);
375		goto err_create;
376	}
377
378	error = lockd_up_net(serv, net);
379	if (error < 0)
380		goto err_net;
381
382	error = lockd_start_svc(serv);
383	if (error < 0)
384		goto err_start;
385
386	nlmsvc_users++;
387	/*
388	 * Note: svc_serv structures have an initial use count of 1,
389	 * so we exit through here on both success and failure.
390	 */
391err_net:
392	svc_destroy(serv);
393err_create:
394	mutex_unlock(&nlmsvc_mutex);
395	return error;
396
397err_start:
398	lockd_down_net(serv, net);
399	goto err_net;
400}
401EXPORT_SYMBOL_GPL(lockd_up);
402
403/*
404 * Decrement the user count and bring down lockd if we're the last.
405 */
406void
407lockd_down(struct net *net)
408{
409	mutex_lock(&nlmsvc_mutex);
410	lockd_down_net(nlmsvc_rqst->rq_server, net);
411	if (nlmsvc_users) {
412		if (--nlmsvc_users)
413			goto out;
414	} else {
415		printk(KERN_ERR "lockd_down: no users! task=%p\n",
416			nlmsvc_task);
417		BUG();
418	}
419
420	if (!nlmsvc_task) {
421		printk(KERN_ERR "lockd_down: no lockd running.\n");
422		BUG();
423	}
424	kthread_stop(nlmsvc_task);
425	dprintk("lockd_down: service stopped\n");
426	svc_exit_thread(nlmsvc_rqst);
427	dprintk("lockd_down: service destroyed\n");
428	nlmsvc_task = NULL;
429	nlmsvc_rqst = NULL;
430out:
431	mutex_unlock(&nlmsvc_mutex);
432}
433EXPORT_SYMBOL_GPL(lockd_down);
434
435#ifdef CONFIG_SYSCTL
436
437/*
438 * Sysctl parameters (same as module parameters, different interface).
439 */
440
441static struct ctl_table nlm_sysctls[] = {
442	{
443		.procname	= "nlm_grace_period",
444		.data		= &nlm_grace_period,
445		.maxlen		= sizeof(unsigned long),
446		.mode		= 0644,
447		.proc_handler	= proc_doulongvec_minmax,
448		.extra1		= (unsigned long *) &nlm_grace_period_min,
449		.extra2		= (unsigned long *) &nlm_grace_period_max,
450	},
451	{
452		.procname	= "nlm_timeout",
453		.data		= &nlm_timeout,
454		.maxlen		= sizeof(unsigned long),
455		.mode		= 0644,
456		.proc_handler	= proc_doulongvec_minmax,
457		.extra1		= (unsigned long *) &nlm_timeout_min,
458		.extra2		= (unsigned long *) &nlm_timeout_max,
459	},
460	{
461		.procname	= "nlm_udpport",
462		.data		= &nlm_udpport,
463		.maxlen		= sizeof(int),
464		.mode		= 0644,
465		.proc_handler	= proc_dointvec_minmax,
466		.extra1		= (int *) &nlm_port_min,
467		.extra2		= (int *) &nlm_port_max,
468	},
469	{
470		.procname	= "nlm_tcpport",
471		.data		= &nlm_tcpport,
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	= "nsm_use_hostnames",
480		.data		= &nsm_use_hostnames,
481		.maxlen		= sizeof(int),
482		.mode		= 0644,
483		.proc_handler	= proc_dointvec,
484	},
485	{
486		.procname	= "nsm_local_state",
487		.data		= &nsm_local_state,
488		.maxlen		= sizeof(int),
489		.mode		= 0644,
490		.proc_handler	= proc_dointvec,
491	},
492	{ }
493};
494
495static struct ctl_table nlm_sysctl_dir[] = {
496	{
497		.procname	= "nfs",
498		.mode		= 0555,
499		.child		= nlm_sysctls,
500	},
501	{ }
502};
503
504static struct ctl_table nlm_sysctl_root[] = {
505	{
506		.procname	= "fs",
507		.mode		= 0555,
508		.child		= nlm_sysctl_dir,
509	},
510	{ }
511};
512
513#endif	/* CONFIG_SYSCTL */
514
515/*
516 * Module (and sysfs) parameters.
517 */
518
519#define param_set_min_max(name, type, which_strtol, min, max)		\
520static int param_set_##name(const char *val, struct kernel_param *kp)	\
521{									\
522	char *endp;							\
523	__typeof__(type) num = which_strtol(val, &endp, 0);		\
524	if (endp == val || *endp || num < (min) || num > (max))		\
525		return -EINVAL;						\
526	*((type *) kp->arg) = num;					\
527	return 0;							\
528}
529
530static inline int is_callback(u32 proc)
531{
532	return proc == NLMPROC_GRANTED
533		|| proc == NLMPROC_GRANTED_MSG
534		|| proc == NLMPROC_TEST_RES
535		|| proc == NLMPROC_LOCK_RES
536		|| proc == NLMPROC_CANCEL_RES
537		|| proc == NLMPROC_UNLOCK_RES
538		|| proc == NLMPROC_NSM_NOTIFY;
539}
540
541
542static int lockd_authenticate(struct svc_rqst *rqstp)
543{
544	rqstp->rq_client = NULL;
545	switch (rqstp->rq_authop->flavour) {
546		case RPC_AUTH_NULL:
547		case RPC_AUTH_UNIX:
548			if (rqstp->rq_proc == 0)
549				return SVC_OK;
550			if (is_callback(rqstp->rq_proc)) {
551				/* Leave it to individual procedures to
552				 * call nlmsvc_lookup_host(rqstp)
553				 */
554				return SVC_OK;
555			}
556			return svc_set_client(rqstp);
557	}
558	return SVC_DENIED;
559}
560
561
562param_set_min_max(port, int, simple_strtol, 0, 65535)
563param_set_min_max(grace_period, unsigned long, simple_strtoul,
564		  nlm_grace_period_min, nlm_grace_period_max)
565param_set_min_max(timeout, unsigned long, simple_strtoul,
566		  nlm_timeout_min, nlm_timeout_max)
567
568MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
569MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
570MODULE_LICENSE("GPL");
571
572module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
573		  &nlm_grace_period, 0644);
574module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
575		  &nlm_timeout, 0644);
576module_param_call(nlm_udpport, param_set_port, param_get_int,
577		  &nlm_udpport, 0644);
578module_param_call(nlm_tcpport, param_set_port, param_get_int,
579		  &nlm_tcpport, 0644);
580module_param(nsm_use_hostnames, bool, 0644);
581module_param(nlm_max_connections, uint, 0644);
582
583static int lockd_init_net(struct net *net)
584{
585	struct lockd_net *ln = net_generic(net, lockd_net_id);
586
587	INIT_DELAYED_WORK(&ln->grace_period_end, grace_ender);
588	INIT_LIST_HEAD(&ln->lockd_manager.list);
589	spin_lock_init(&ln->nsm_clnt_lock);
590	return 0;
591}
592
593static void lockd_exit_net(struct net *net)
594{
595}
596
597static struct pernet_operations lockd_net_ops = {
598	.init = lockd_init_net,
599	.exit = lockd_exit_net,
600	.id = &lockd_net_id,
601	.size = sizeof(struct lockd_net),
602};
603
604
605/*
606 * Initialising and terminating the module.
607 */
608
609static int __init init_nlm(void)
610{
611	int err;
612
613#ifdef CONFIG_SYSCTL
614	err = -ENOMEM;
615	nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
616	if (nlm_sysctl_table == NULL)
617		goto err_sysctl;
618#endif
619	err = register_pernet_subsys(&lockd_net_ops);
620	if (err)
621		goto err_pernet;
622
623	err = lockd_create_procfs();
624	if (err)
625		goto err_procfs;
626
627	return 0;
628
629err_procfs:
630	unregister_pernet_subsys(&lockd_net_ops);
631err_pernet:
632#ifdef CONFIG_SYSCTL
633	unregister_sysctl_table(nlm_sysctl_table);
634err_sysctl:
635#endif
636	return err;
637}
638
639static void __exit exit_nlm(void)
640{
641	/* FIXME: delete all NLM clients */
642	nlm_shutdown_hosts();
643	lockd_remove_procfs();
644	unregister_pernet_subsys(&lockd_net_ops);
645#ifdef CONFIG_SYSCTL
646	unregister_sysctl_table(nlm_sysctl_table);
647#endif
648}
649
650module_init(init_nlm);
651module_exit(exit_nlm);
652
653/*
654 * Define NLM program and procedures
655 */
656static struct svc_version	nlmsvc_version1 = {
657		.vs_vers	= 1,
658		.vs_nproc	= 17,
659		.vs_proc	= nlmsvc_procedures,
660		.vs_xdrsize	= NLMSVC_XDRSIZE,
661};
662static struct svc_version	nlmsvc_version3 = {
663		.vs_vers	= 3,
664		.vs_nproc	= 24,
665		.vs_proc	= nlmsvc_procedures,
666		.vs_xdrsize	= NLMSVC_XDRSIZE,
667};
668#ifdef CONFIG_LOCKD_V4
669static struct svc_version	nlmsvc_version4 = {
670		.vs_vers	= 4,
671		.vs_nproc	= 24,
672		.vs_proc	= nlmsvc_procedures4,
673		.vs_xdrsize	= NLMSVC_XDRSIZE,
674};
675#endif
676static struct svc_version *	nlmsvc_version[] = {
677	[1] = &nlmsvc_version1,
678	[3] = &nlmsvc_version3,
679#ifdef CONFIG_LOCKD_V4
680	[4] = &nlmsvc_version4,
681#endif
682};
683
684static struct svc_stat		nlmsvc_stats;
685
686#define NLM_NRVERS	ARRAY_SIZE(nlmsvc_version)
687static struct svc_program	nlmsvc_program = {
688	.pg_prog		= NLM_PROGRAM,		/* program number */
689	.pg_nvers		= NLM_NRVERS,		/* number of entries in nlmsvc_version */
690	.pg_vers		= nlmsvc_version,	/* version table */
691	.pg_name		= "lockd",		/* service name */
692	.pg_class		= "nfsd",		/* share authentication with nfsd */
693	.pg_stats		= &nlmsvc_stats,	/* stats table */
694	.pg_authenticate = &lockd_authenticate	/* export authentication */
695};
696