xref: /linux/fs/lockd/svcproc.c (revision cb299ba8b5ef2239429484072fea394cd7581bd7)
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/smp_lock.h>
13 #include <linux/lockd/lockd.h>
14 #include <linux/lockd/share.h>
15 
16 #define NLMDBG_FACILITY		NLMDBG_CLIENT
17 
18 #ifdef CONFIG_LOCKD_V4
19 static __be32
20 cast_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  */
50 static __be32
51 nlmsvc_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 		if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
72 			goto no_locks;
73 		*filp = file;
74 
75 		/* Set up the missing parts of the file_lock structure */
76 		lock->fl.fl_file  = file->f_file;
77 		lock->fl.fl_owner = (fl_owner_t) host;
78 		lock->fl.fl_lmops = &nlmsvc_lock_operations;
79 	}
80 
81 	return 0;
82 
83 no_locks:
84 	nlm_release_host(host);
85 	if (error)
86 		return error;
87 	return nlm_lck_denied_nolocks;
88 }
89 
90 /*
91  * NULL: Test for presence of service
92  */
93 static __be32
94 nlmsvc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
95 {
96 	dprintk("lockd: NULL          called\n");
97 	return rpc_success;
98 }
99 
100 /*
101  * TEST: Check for conflicting lock
102  */
103 static __be32
104 nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
105 				         struct nlm_res  *resp)
106 {
107 	struct nlm_host	*host;
108 	struct nlm_file	*file;
109 	__be32 rc = rpc_success;
110 
111 	dprintk("lockd: TEST          called\n");
112 	resp->cookie = argp->cookie;
113 
114 	/* Obtain client and file */
115 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
116 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
117 
118 	/* Now check for conflicting locks */
119 	resp->status = cast_status(nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie));
120 	if (resp->status == nlm_drop_reply)
121 		rc = rpc_drop_reply;
122 	else
123 		dprintk("lockd: TEST          status %d vers %d\n",
124 			ntohl(resp->status), rqstp->rq_vers);
125 
126 	nlm_release_host(host);
127 	nlm_release_file(file);
128 	return rc;
129 }
130 
131 static __be32
132 nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
133 				         struct nlm_res  *resp)
134 {
135 	struct nlm_host	*host;
136 	struct nlm_file	*file;
137 	__be32 rc = rpc_success;
138 
139 	dprintk("lockd: LOCK          called\n");
140 
141 	resp->cookie = argp->cookie;
142 
143 	/* Obtain client and file */
144 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
145 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
146 
147 #if 0
148 	/* If supplied state doesn't match current state, we assume it's
149 	 * an old request that time-warped somehow. Any error return would
150 	 * do in this case because it's irrelevant anyway.
151 	 *
152 	 * NB: We don't retrieve the remote host's state yet.
153 	 */
154 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
155 		resp->status = nlm_lck_denied_nolocks;
156 	} else
157 #endif
158 
159 	/* Now try to lock the file */
160 	resp->status = cast_status(nlmsvc_lock(rqstp, file, host, &argp->lock,
161 					       argp->block, &argp->cookie,
162 					       argp->reclaim));
163 	if (resp->status == nlm_drop_reply)
164 		rc = rpc_drop_reply;
165 	else
166 		dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
167 
168 	nlm_release_host(host);
169 	nlm_release_file(file);
170 	return rc;
171 }
172 
173 static __be32
174 nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
175 				           struct nlm_res  *resp)
176 {
177 	struct nlm_host	*host;
178 	struct nlm_file	*file;
179 
180 	dprintk("lockd: CANCEL        called\n");
181 
182 	resp->cookie = argp->cookie;
183 
184 	/* Don't accept requests during grace period */
185 	if (locks_in_grace()) {
186 		resp->status = nlm_lck_denied_grace_period;
187 		return rpc_success;
188 	}
189 
190 	/* Obtain client and file */
191 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
192 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
193 
194 	/* Try to cancel request. */
195 	resp->status = cast_status(nlmsvc_cancel_blocked(file, &argp->lock));
196 
197 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
198 	nlm_release_host(host);
199 	nlm_release_file(file);
200 	return rpc_success;
201 }
202 
203 /*
204  * UNLOCK: release a lock
205  */
206 static __be32
207 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
208 				           struct nlm_res  *resp)
209 {
210 	struct nlm_host	*host;
211 	struct nlm_file	*file;
212 
213 	dprintk("lockd: UNLOCK        called\n");
214 
215 	resp->cookie = argp->cookie;
216 
217 	/* Don't accept new lock requests during grace period */
218 	if (locks_in_grace()) {
219 		resp->status = nlm_lck_denied_grace_period;
220 		return rpc_success;
221 	}
222 
223 	/* Obtain client and file */
224 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
225 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
226 
227 	/* Now try to remove the lock */
228 	resp->status = cast_status(nlmsvc_unlock(file, &argp->lock));
229 
230 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
231 	nlm_release_host(host);
232 	nlm_release_file(file);
233 	return rpc_success;
234 }
235 
236 /*
237  * GRANTED: A server calls us to tell that a process' lock request
238  * was granted
239  */
240 static __be32
241 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
242 				            struct nlm_res  *resp)
243 {
244 	resp->cookie = argp->cookie;
245 
246 	dprintk("lockd: GRANTED       called\n");
247 	resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
248 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
249 	return rpc_success;
250 }
251 
252 /*
253  * This is the generic lockd callback for async RPC calls
254  */
255 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
256 {
257 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
258 			-task->tk_status);
259 }
260 
261 static void nlmsvc_callback_release(void *data)
262 {
263 	nlm_release_call(data);
264 }
265 
266 static const struct rpc_call_ops nlmsvc_callback_ops = {
267 	.rpc_call_done = nlmsvc_callback_exit,
268 	.rpc_release = nlmsvc_callback_release,
269 };
270 
271 /*
272  * `Async' versions of the above service routines. They aren't really,
273  * because we send the callback before the reply proper. I hope this
274  * doesn't break any clients.
275  */
276 static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
277 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
278 {
279 	struct nlm_host	*host;
280 	struct nlm_rqst	*call;
281 	__be32 stat;
282 
283 	host = nlmsvc_lookup_host(rqstp,
284 				  argp->lock.caller,
285 				  argp->lock.len);
286 	if (host == NULL)
287 		return rpc_system_err;
288 
289 	call = nlm_alloc_call(host);
290 	if (call == NULL)
291 		return rpc_system_err;
292 
293 	stat = func(rqstp, argp, &call->a_res);
294 	if (stat != 0) {
295 		nlm_release_call(call);
296 		return stat;
297 	}
298 
299 	call->a_flags = RPC_TASK_ASYNC;
300 	if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
301 		return rpc_system_err;
302 	return rpc_success;
303 }
304 
305 static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
306 					     void	     *resp)
307 {
308 	dprintk("lockd: TEST_MSG      called\n");
309 	return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
310 }
311 
312 static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
313 					     void	     *resp)
314 {
315 	dprintk("lockd: LOCK_MSG      called\n");
316 	return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
317 }
318 
319 static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
320 					       void	       *resp)
321 {
322 	dprintk("lockd: CANCEL_MSG    called\n");
323 	return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
324 }
325 
326 static __be32
327 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
328                                                void            *resp)
329 {
330 	dprintk("lockd: UNLOCK_MSG    called\n");
331 	return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
332 }
333 
334 static __be32
335 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
336                                                 void            *resp)
337 {
338 	dprintk("lockd: GRANTED_MSG   called\n");
339 	return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
340 }
341 
342 /*
343  * SHARE: create a DOS share or alter existing share.
344  */
345 static __be32
346 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
347 				          struct nlm_res  *resp)
348 {
349 	struct nlm_host	*host;
350 	struct nlm_file	*file;
351 
352 	dprintk("lockd: SHARE         called\n");
353 
354 	resp->cookie = argp->cookie;
355 
356 	/* Don't accept new lock requests during grace period */
357 	if (locks_in_grace() && !argp->reclaim) {
358 		resp->status = nlm_lck_denied_grace_period;
359 		return rpc_success;
360 	}
361 
362 	/* Obtain client and file */
363 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
364 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
365 
366 	/* Now try to create the share */
367 	resp->status = cast_status(nlmsvc_share_file(host, file, argp));
368 
369 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
370 	nlm_release_host(host);
371 	nlm_release_file(file);
372 	return rpc_success;
373 }
374 
375 /*
376  * UNSHARE: Release a DOS share.
377  */
378 static __be32
379 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
380 				            struct nlm_res  *resp)
381 {
382 	struct nlm_host	*host;
383 	struct nlm_file	*file;
384 
385 	dprintk("lockd: UNSHARE       called\n");
386 
387 	resp->cookie = argp->cookie;
388 
389 	/* Don't accept requests during grace period */
390 	if (locks_in_grace()) {
391 		resp->status = nlm_lck_denied_grace_period;
392 		return rpc_success;
393 	}
394 
395 	/* Obtain client and file */
396 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
397 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
398 
399 	/* Now try to unshare the file */
400 	resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
401 
402 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
403 	nlm_release_host(host);
404 	nlm_release_file(file);
405 	return rpc_success;
406 }
407 
408 /*
409  * NM_LOCK: Create an unmonitored lock
410  */
411 static __be32
412 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
413 				            struct nlm_res  *resp)
414 {
415 	dprintk("lockd: NM_LOCK       called\n");
416 
417 	argp->monitor = 0;		/* just clean the monitor flag */
418 	return nlmsvc_proc_lock(rqstp, argp, resp);
419 }
420 
421 /*
422  * FREE_ALL: Release all locks and shares held by client
423  */
424 static __be32
425 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
426 					     void            *resp)
427 {
428 	struct nlm_host	*host;
429 
430 	/* Obtain client */
431 	if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
432 		return rpc_success;
433 
434 	nlmsvc_free_host_resources(host);
435 	nlm_release_host(host);
436 	return rpc_success;
437 }
438 
439 /*
440  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
441  */
442 static __be32
443 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
444 					      void	        *resp)
445 {
446 	dprintk("lockd: SM_NOTIFY     called\n");
447 
448 	if (!nlm_privileged_requester(rqstp)) {
449 		char buf[RPC_MAX_ADDRBUFLEN];
450 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
451 				svc_print_addr(rqstp, buf, sizeof(buf)));
452 		return rpc_system_err;
453 	}
454 
455 	nlm_host_rebooted(argp);
456 	return rpc_success;
457 }
458 
459 /*
460  * client sent a GRANTED_RES, let's remove the associated block
461  */
462 static __be32
463 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
464                                                 void            *resp)
465 {
466 	if (!nlmsvc_ops)
467 		return rpc_success;
468 
469 	dprintk("lockd: GRANTED_RES   called\n");
470 
471 	nlmsvc_grant_reply(&argp->cookie, argp->status);
472 	return rpc_success;
473 }
474 
475 /*
476  * NLM Server procedures.
477  */
478 
479 #define nlmsvc_encode_norep	nlmsvc_encode_void
480 #define nlmsvc_decode_norep	nlmsvc_decode_void
481 #define nlmsvc_decode_testres	nlmsvc_decode_void
482 #define nlmsvc_decode_lockres	nlmsvc_decode_void
483 #define nlmsvc_decode_unlockres	nlmsvc_decode_void
484 #define nlmsvc_decode_cancelres	nlmsvc_decode_void
485 #define nlmsvc_decode_grantedres	nlmsvc_decode_void
486 
487 #define nlmsvc_proc_none	nlmsvc_proc_null
488 #define nlmsvc_proc_test_res	nlmsvc_proc_null
489 #define nlmsvc_proc_lock_res	nlmsvc_proc_null
490 #define nlmsvc_proc_cancel_res	nlmsvc_proc_null
491 #define nlmsvc_proc_unlock_res	nlmsvc_proc_null
492 
493 struct nlm_void			{ int dummy; };
494 
495 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
496  { .pc_func	= (svc_procfunc) nlmsvc_proc_##name,	\
497    .pc_decode	= (kxdrproc_t) nlmsvc_decode_##xargt,	\
498    .pc_encode	= (kxdrproc_t) nlmsvc_encode_##xrest,	\
499    .pc_release	= NULL,					\
500    .pc_argsize	= sizeof(struct nlm_##argt),		\
501    .pc_ressize	= sizeof(struct nlm_##rest),		\
502    .pc_xdrressize = respsize,				\
503  }
504 
505 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
506 #define	St	1				/* status */
507 #define	No	(1+1024/4)			/* Net Obj */
508 #define	Rg	2				/* range - offset + size */
509 
510 struct svc_procedure		nlmsvc_procedures[] = {
511   PROC(null,		void,		void,		void,	void, 1),
512   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
513   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
514   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
515   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
516   PROC(granted,		testargs,	res,		args,	res, Ck+St),
517   PROC(test_msg,	testargs,	norep,		args,	void, 1),
518   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
519   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
520   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
521   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
522   PROC(test_res,	testres,	norep,		res,	void, 1),
523   PROC(lock_res,	lockres,	norep,		res,	void, 1),
524   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
525   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
526   PROC(granted_res,	res,		norep,		res,	void, 1),
527   /* statd callback */
528   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
529   PROC(none,		void,		void,		void,	void, 1),
530   PROC(none,		void,		void,		void,	void, 1),
531   PROC(none,		void,		void,		void,	void, 1),
532   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
533   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
534   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
535   PROC(free_all,	notify,		void,		args,	void, 0),
536 
537 };
538