1/*
2 * linux/fs/lockd/svcproc.c
3 *
4 * Lockd server procedures. We don't implement the NLM_*_RES
5 * procedures because we don't use the async procedures.
6 *
7 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
8 */
9
10#include <linux/types.h>
11#include <linux/time.h>
12#include <linux/lockd/lockd.h>
13#include <linux/lockd/share.h>
14#include <linux/sunrpc/svc_xprt.h>
15
16#define NLMDBG_FACILITY		NLMDBG_CLIENT
17
18#ifdef CONFIG_LOCKD_V4
19static __be32
20cast_to_nlm(__be32 status, u32 vers)
21{
22	/* Note: status is assumed to be in network byte order !!! */
23	if (vers != 4){
24		switch (status) {
25		case nlm_granted:
26		case nlm_lck_denied:
27		case nlm_lck_denied_nolocks:
28		case nlm_lck_blocked:
29		case nlm_lck_denied_grace_period:
30		case nlm_drop_reply:
31			break;
32		case nlm4_deadlock:
33			status = nlm_lck_denied;
34			break;
35		default:
36			status = nlm_lck_denied_nolocks;
37		}
38	}
39
40	return (status);
41}
42#define	cast_status(status) (cast_to_nlm(status, rqstp->rq_vers))
43#else
44#define cast_status(status) (status)
45#endif
46
47/*
48 * Obtain client and file from arguments
49 */
50static __be32
51nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
52			struct nlm_host **hostp, struct nlm_file **filp)
53{
54	struct nlm_host		*host = NULL;
55	struct nlm_file		*file = NULL;
56	struct nlm_lock		*lock = &argp->lock;
57	__be32			error = 0;
58
59	/* nfsd callbacks must have been installed for this procedure */
60	if (!nlmsvc_ops)
61		return nlm_lck_denied_nolocks;
62
63	/* Obtain host handle */
64	if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
65	 || (argp->monitor && nsm_monitor(host) < 0))
66		goto no_locks;
67	*hostp = host;
68
69	/* Obtain file pointer. Not used by FREE_ALL call. */
70	if (filp != NULL) {
71		error = cast_status(nlm_lookup_file(rqstp, &file, &lock->fh));
72		if (error != 0)
73			goto no_locks;
74		*filp = file;
75
76		/* Set up the missing parts of the file_lock structure */
77		lock->fl.fl_file  = file->f_file;
78		lock->fl.fl_owner = (fl_owner_t) host;
79		lock->fl.fl_lmops = &nlmsvc_lock_operations;
80	}
81
82	return 0;
83
84no_locks:
85	nlmsvc_release_host(host);
86	if (error)
87		return error;
88	return nlm_lck_denied_nolocks;
89}
90
91/*
92 * NULL: Test for presence of service
93 */
94static __be32
95nlmsvc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
96{
97	dprintk("lockd: NULL          called\n");
98	return rpc_success;
99}
100
101/*
102 * TEST: Check for conflicting lock
103 */
104static __be32
105nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
106				         struct nlm_res  *resp)
107{
108	struct nlm_host	*host;
109	struct nlm_file	*file;
110	__be32 rc = rpc_success;
111
112	dprintk("lockd: TEST          called\n");
113	resp->cookie = argp->cookie;
114
115	/* Obtain client and file */
116	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
117		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
118
119	/* Now check for conflicting locks */
120	resp->status = cast_status(nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie));
121	if (resp->status == nlm_drop_reply)
122		rc = rpc_drop_reply;
123	else
124		dprintk("lockd: TEST          status %d vers %d\n",
125			ntohl(resp->status), rqstp->rq_vers);
126
127	nlmsvc_release_host(host);
128	nlm_release_file(file);
129	return rc;
130}
131
132static __be32
133nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
134				         struct nlm_res  *resp)
135{
136	struct nlm_host	*host;
137	struct nlm_file	*file;
138	__be32 rc = rpc_success;
139
140	dprintk("lockd: LOCK          called\n");
141
142	resp->cookie = argp->cookie;
143
144	/* Obtain client and file */
145	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
146		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
147
148#if 0
149	/* If supplied state doesn't match current state, we assume it's
150	 * an old request that time-warped somehow. Any error return would
151	 * do in this case because it's irrelevant anyway.
152	 *
153	 * NB: We don't retrieve the remote host's state yet.
154	 */
155	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
156		resp->status = nlm_lck_denied_nolocks;
157	} else
158#endif
159
160	/* Now try to lock the file */
161	resp->status = cast_status(nlmsvc_lock(rqstp, file, host, &argp->lock,
162					       argp->block, &argp->cookie,
163					       argp->reclaim));
164	if (resp->status == nlm_drop_reply)
165		rc = rpc_drop_reply;
166	else
167		dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
168
169	nlmsvc_release_host(host);
170	nlm_release_file(file);
171	return rc;
172}
173
174static __be32
175nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
176				           struct nlm_res  *resp)
177{
178	struct nlm_host	*host;
179	struct nlm_file	*file;
180	struct net *net = SVC_NET(rqstp);
181
182	dprintk("lockd: CANCEL        called\n");
183
184	resp->cookie = argp->cookie;
185
186	/* Don't accept requests during grace period */
187	if (locks_in_grace(net)) {
188		resp->status = nlm_lck_denied_grace_period;
189		return rpc_success;
190	}
191
192	/* Obtain client and file */
193	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
194		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
195
196	/* Try to cancel request. */
197	resp->status = cast_status(nlmsvc_cancel_blocked(net, file, &argp->lock));
198
199	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
200	nlmsvc_release_host(host);
201	nlm_release_file(file);
202	return rpc_success;
203}
204
205/*
206 * UNLOCK: release a lock
207 */
208static __be32
209nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
210				           struct nlm_res  *resp)
211{
212	struct nlm_host	*host;
213	struct nlm_file	*file;
214	struct net *net = SVC_NET(rqstp);
215
216	dprintk("lockd: UNLOCK        called\n");
217
218	resp->cookie = argp->cookie;
219
220	/* Don't accept new lock requests during grace period */
221	if (locks_in_grace(net)) {
222		resp->status = nlm_lck_denied_grace_period;
223		return rpc_success;
224	}
225
226	/* Obtain client and file */
227	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
228		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
229
230	/* Now try to remove the lock */
231	resp->status = cast_status(nlmsvc_unlock(net, file, &argp->lock));
232
233	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
234	nlmsvc_release_host(host);
235	nlm_release_file(file);
236	return rpc_success;
237}
238
239/*
240 * GRANTED: A server calls us to tell that a process' lock request
241 * was granted
242 */
243static __be32
244nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
245				            struct nlm_res  *resp)
246{
247	resp->cookie = argp->cookie;
248
249	dprintk("lockd: GRANTED       called\n");
250	resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
251	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
252	return rpc_success;
253}
254
255/*
256 * This is the generic lockd callback for async RPC calls
257 */
258static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
259{
260	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
261			-task->tk_status);
262}
263
264void nlmsvc_release_call(struct nlm_rqst *call)
265{
266	if (!atomic_dec_and_test(&call->a_count))
267		return;
268	nlmsvc_release_host(call->a_host);
269	kfree(call);
270}
271
272static void nlmsvc_callback_release(void *data)
273{
274	nlmsvc_release_call(data);
275}
276
277static const struct rpc_call_ops nlmsvc_callback_ops = {
278	.rpc_call_done = nlmsvc_callback_exit,
279	.rpc_release = nlmsvc_callback_release,
280};
281
282/*
283 * `Async' versions of the above service routines. They aren't really,
284 * because we send the callback before the reply proper. I hope this
285 * doesn't break any clients.
286 */
287static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
288		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
289{
290	struct nlm_host	*host;
291	struct nlm_rqst	*call;
292	__be32 stat;
293
294	host = nlmsvc_lookup_host(rqstp,
295				  argp->lock.caller,
296				  argp->lock.len);
297	if (host == NULL)
298		return rpc_system_err;
299
300	call = nlm_alloc_call(host);
301	nlmsvc_release_host(host);
302	if (call == NULL)
303		return rpc_system_err;
304
305	stat = func(rqstp, argp, &call->a_res);
306	if (stat != 0) {
307		nlmsvc_release_call(call);
308		return stat;
309	}
310
311	call->a_flags = RPC_TASK_ASYNC;
312	if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
313		return rpc_system_err;
314	return rpc_success;
315}
316
317static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
318					     void	     *resp)
319{
320	dprintk("lockd: TEST_MSG      called\n");
321	return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
322}
323
324static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
325					     void	     *resp)
326{
327	dprintk("lockd: LOCK_MSG      called\n");
328	return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
329}
330
331static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
332					       void	       *resp)
333{
334	dprintk("lockd: CANCEL_MSG    called\n");
335	return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
336}
337
338static __be32
339nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
340                                               void            *resp)
341{
342	dprintk("lockd: UNLOCK_MSG    called\n");
343	return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
344}
345
346static __be32
347nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
348                                                void            *resp)
349{
350	dprintk("lockd: GRANTED_MSG   called\n");
351	return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
352}
353
354/*
355 * SHARE: create a DOS share or alter existing share.
356 */
357static __be32
358nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
359				          struct nlm_res  *resp)
360{
361	struct nlm_host	*host;
362	struct nlm_file	*file;
363
364	dprintk("lockd: SHARE         called\n");
365
366	resp->cookie = argp->cookie;
367
368	/* Don't accept new lock requests during grace period */
369	if (locks_in_grace(SVC_NET(rqstp)) && !argp->reclaim) {
370		resp->status = nlm_lck_denied_grace_period;
371		return rpc_success;
372	}
373
374	/* Obtain client and file */
375	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
376		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
377
378	/* Now try to create the share */
379	resp->status = cast_status(nlmsvc_share_file(host, file, argp));
380
381	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
382	nlmsvc_release_host(host);
383	nlm_release_file(file);
384	return rpc_success;
385}
386
387/*
388 * UNSHARE: Release a DOS share.
389 */
390static __be32
391nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
392				            struct nlm_res  *resp)
393{
394	struct nlm_host	*host;
395	struct nlm_file	*file;
396
397	dprintk("lockd: UNSHARE       called\n");
398
399	resp->cookie = argp->cookie;
400
401	/* Don't accept requests during grace period */
402	if (locks_in_grace(SVC_NET(rqstp))) {
403		resp->status = nlm_lck_denied_grace_period;
404		return rpc_success;
405	}
406
407	/* Obtain client and file */
408	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
409		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
410
411	/* Now try to unshare the file */
412	resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
413
414	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
415	nlmsvc_release_host(host);
416	nlm_release_file(file);
417	return rpc_success;
418}
419
420/*
421 * NM_LOCK: Create an unmonitored lock
422 */
423static __be32
424nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
425				            struct nlm_res  *resp)
426{
427	dprintk("lockd: NM_LOCK       called\n");
428
429	argp->monitor = 0;		/* just clean the monitor flag */
430	return nlmsvc_proc_lock(rqstp, argp, resp);
431}
432
433/*
434 * FREE_ALL: Release all locks and shares held by client
435 */
436static __be32
437nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
438					     void            *resp)
439{
440	struct nlm_host	*host;
441
442	/* Obtain client */
443	if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
444		return rpc_success;
445
446	nlmsvc_free_host_resources(host);
447	nlmsvc_release_host(host);
448	return rpc_success;
449}
450
451/*
452 * SM_NOTIFY: private callback from statd (not part of official NLM proto)
453 */
454static __be32
455nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
456					      void	        *resp)
457{
458	dprintk("lockd: SM_NOTIFY     called\n");
459
460	if (!nlm_privileged_requester(rqstp)) {
461		char buf[RPC_MAX_ADDRBUFLEN];
462		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
463				svc_print_addr(rqstp, buf, sizeof(buf)));
464		return rpc_system_err;
465	}
466
467	nlm_host_rebooted(SVC_NET(rqstp), argp);
468	return rpc_success;
469}
470
471/*
472 * client sent a GRANTED_RES, let's remove the associated block
473 */
474static __be32
475nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
476                                                void            *resp)
477{
478	if (!nlmsvc_ops)
479		return rpc_success;
480
481	dprintk("lockd: GRANTED_RES   called\n");
482
483	nlmsvc_grant_reply(&argp->cookie, argp->status);
484	return rpc_success;
485}
486
487/*
488 * NLM Server procedures.
489 */
490
491#define nlmsvc_encode_norep	nlmsvc_encode_void
492#define nlmsvc_decode_norep	nlmsvc_decode_void
493#define nlmsvc_decode_testres	nlmsvc_decode_void
494#define nlmsvc_decode_lockres	nlmsvc_decode_void
495#define nlmsvc_decode_unlockres	nlmsvc_decode_void
496#define nlmsvc_decode_cancelres	nlmsvc_decode_void
497#define nlmsvc_decode_grantedres	nlmsvc_decode_void
498
499#define nlmsvc_proc_none	nlmsvc_proc_null
500#define nlmsvc_proc_test_res	nlmsvc_proc_null
501#define nlmsvc_proc_lock_res	nlmsvc_proc_null
502#define nlmsvc_proc_cancel_res	nlmsvc_proc_null
503#define nlmsvc_proc_unlock_res	nlmsvc_proc_null
504
505struct nlm_void			{ int dummy; };
506
507#define PROC(name, xargt, xrest, argt, rest, respsize)	\
508 { .pc_func	= (svc_procfunc) nlmsvc_proc_##name,	\
509   .pc_decode	= (kxdrproc_t) nlmsvc_decode_##xargt,	\
510   .pc_encode	= (kxdrproc_t) nlmsvc_encode_##xrest,	\
511   .pc_release	= NULL,					\
512   .pc_argsize	= sizeof(struct nlm_##argt),		\
513   .pc_ressize	= sizeof(struct nlm_##rest),		\
514   .pc_xdrressize = respsize,				\
515 }
516
517#define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
518#define	St	1				/* status */
519#define	No	(1+1024/4)			/* Net Obj */
520#define	Rg	2				/* range - offset + size */
521
522struct svc_procedure		nlmsvc_procedures[] = {
523  PROC(null,		void,		void,		void,	void, 1),
524  PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
525  PROC(lock,		lockargs,	res,		args,	res, Ck+St),
526  PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
527  PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
528  PROC(granted,		testargs,	res,		args,	res, Ck+St),
529  PROC(test_msg,	testargs,	norep,		args,	void, 1),
530  PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
531  PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
532  PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
533  PROC(granted_msg,	testargs,	norep,		args,	void, 1),
534  PROC(test_res,	testres,	norep,		res,	void, 1),
535  PROC(lock_res,	lockres,	norep,		res,	void, 1),
536  PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
537  PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
538  PROC(granted_res,	res,		norep,		res,	void, 1),
539  /* statd callback */
540  PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
541  PROC(none,		void,		void,		void,	void, 1),
542  PROC(none,		void,		void,		void,	void, 1),
543  PROC(none,		void,		void,		void,	void, 1),
544  PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
545  PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
546  PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
547  PROC(free_all,	notify,		void,		args,	void, 0),
548
549};
550