xref: /linux/fs/lockd/svcproc.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
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 	lock_kernel();
264 	nlm_release_call(data);
265 	unlock_kernel();
266 }
267 
268 static const struct rpc_call_ops nlmsvc_callback_ops = {
269 	.rpc_call_done = nlmsvc_callback_exit,
270 	.rpc_release = nlmsvc_callback_release,
271 };
272 
273 /*
274  * `Async' versions of the above service routines. They aren't really,
275  * because we send the callback before the reply proper. I hope this
276  * doesn't break any clients.
277  */
278 static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
279 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
280 {
281 	struct nlm_host	*host;
282 	struct nlm_rqst	*call;
283 	__be32 stat;
284 
285 	host = nlmsvc_lookup_host(rqstp,
286 				  argp->lock.caller,
287 				  argp->lock.len);
288 	if (host == NULL)
289 		return rpc_system_err;
290 
291 	call = nlm_alloc_call(host);
292 	if (call == NULL)
293 		return rpc_system_err;
294 
295 	stat = func(rqstp, argp, &call->a_res);
296 	if (stat != 0) {
297 		nlm_release_call(call);
298 		return stat;
299 	}
300 
301 	call->a_flags = RPC_TASK_ASYNC;
302 	if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
303 		return rpc_system_err;
304 	return rpc_success;
305 }
306 
307 static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
308 					     void	     *resp)
309 {
310 	dprintk("lockd: TEST_MSG      called\n");
311 	return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
312 }
313 
314 static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
315 					     void	     *resp)
316 {
317 	dprintk("lockd: LOCK_MSG      called\n");
318 	return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
319 }
320 
321 static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
322 					       void	       *resp)
323 {
324 	dprintk("lockd: CANCEL_MSG    called\n");
325 	return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
326 }
327 
328 static __be32
329 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
330                                                void            *resp)
331 {
332 	dprintk("lockd: UNLOCK_MSG    called\n");
333 	return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
334 }
335 
336 static __be32
337 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
338                                                 void            *resp)
339 {
340 	dprintk("lockd: GRANTED_MSG   called\n");
341 	return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
342 }
343 
344 /*
345  * SHARE: create a DOS share or alter existing share.
346  */
347 static __be32
348 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
349 				          struct nlm_res  *resp)
350 {
351 	struct nlm_host	*host;
352 	struct nlm_file	*file;
353 
354 	dprintk("lockd: SHARE         called\n");
355 
356 	resp->cookie = argp->cookie;
357 
358 	/* Don't accept new lock requests during grace period */
359 	if (locks_in_grace() && !argp->reclaim) {
360 		resp->status = nlm_lck_denied_grace_period;
361 		return rpc_success;
362 	}
363 
364 	/* Obtain client and file */
365 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
366 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
367 
368 	/* Now try to create the share */
369 	resp->status = cast_status(nlmsvc_share_file(host, file, argp));
370 
371 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
372 	nlm_release_host(host);
373 	nlm_release_file(file);
374 	return rpc_success;
375 }
376 
377 /*
378  * UNSHARE: Release a DOS share.
379  */
380 static __be32
381 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
382 				            struct nlm_res  *resp)
383 {
384 	struct nlm_host	*host;
385 	struct nlm_file	*file;
386 
387 	dprintk("lockd: UNSHARE       called\n");
388 
389 	resp->cookie = argp->cookie;
390 
391 	/* Don't accept requests during grace period */
392 	if (locks_in_grace()) {
393 		resp->status = nlm_lck_denied_grace_period;
394 		return rpc_success;
395 	}
396 
397 	/* Obtain client and file */
398 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
399 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
400 
401 	/* Now try to unshare the file */
402 	resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
403 
404 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
405 	nlm_release_host(host);
406 	nlm_release_file(file);
407 	return rpc_success;
408 }
409 
410 /*
411  * NM_LOCK: Create an unmonitored lock
412  */
413 static __be32
414 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
415 				            struct nlm_res  *resp)
416 {
417 	dprintk("lockd: NM_LOCK       called\n");
418 
419 	argp->monitor = 0;		/* just clean the monitor flag */
420 	return nlmsvc_proc_lock(rqstp, argp, resp);
421 }
422 
423 /*
424  * FREE_ALL: Release all locks and shares held by client
425  */
426 static __be32
427 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
428 					     void            *resp)
429 {
430 	struct nlm_host	*host;
431 
432 	/* Obtain client */
433 	if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
434 		return rpc_success;
435 
436 	nlmsvc_free_host_resources(host);
437 	nlm_release_host(host);
438 	return rpc_success;
439 }
440 
441 /*
442  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
443  */
444 static __be32
445 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
446 					      void	        *resp)
447 {
448 	dprintk("lockd: SM_NOTIFY     called\n");
449 
450 	if (!nlm_privileged_requester(rqstp)) {
451 		char buf[RPC_MAX_ADDRBUFLEN];
452 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
453 				svc_print_addr(rqstp, buf, sizeof(buf)));
454 		return rpc_system_err;
455 	}
456 
457 	nlm_host_rebooted(argp);
458 	return rpc_success;
459 }
460 
461 /*
462  * client sent a GRANTED_RES, let's remove the associated block
463  */
464 static __be32
465 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
466                                                 void            *resp)
467 {
468 	if (!nlmsvc_ops)
469 		return rpc_success;
470 
471 	dprintk("lockd: GRANTED_RES   called\n");
472 
473 	nlmsvc_grant_reply(&argp->cookie, argp->status);
474 	return rpc_success;
475 }
476 
477 /*
478  * NLM Server procedures.
479  */
480 
481 #define nlmsvc_encode_norep	nlmsvc_encode_void
482 #define nlmsvc_decode_norep	nlmsvc_decode_void
483 #define nlmsvc_decode_testres	nlmsvc_decode_void
484 #define nlmsvc_decode_lockres	nlmsvc_decode_void
485 #define nlmsvc_decode_unlockres	nlmsvc_decode_void
486 #define nlmsvc_decode_cancelres	nlmsvc_decode_void
487 #define nlmsvc_decode_grantedres	nlmsvc_decode_void
488 
489 #define nlmsvc_proc_none	nlmsvc_proc_null
490 #define nlmsvc_proc_test_res	nlmsvc_proc_null
491 #define nlmsvc_proc_lock_res	nlmsvc_proc_null
492 #define nlmsvc_proc_cancel_res	nlmsvc_proc_null
493 #define nlmsvc_proc_unlock_res	nlmsvc_proc_null
494 
495 struct nlm_void			{ int dummy; };
496 
497 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
498  { .pc_func	= (svc_procfunc) nlmsvc_proc_##name,	\
499    .pc_decode	= (kxdrproc_t) nlmsvc_decode_##xargt,	\
500    .pc_encode	= (kxdrproc_t) nlmsvc_encode_##xrest,	\
501    .pc_release	= NULL,					\
502    .pc_argsize	= sizeof(struct nlm_##argt),		\
503    .pc_ressize	= sizeof(struct nlm_##rest),		\
504    .pc_xdrressize = respsize,				\
505  }
506 
507 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
508 #define	St	1				/* status */
509 #define	No	(1+1024/4)			/* Net Obj */
510 #define	Rg	2				/* range - offset + size */
511 
512 struct svc_procedure		nlmsvc_procedures[] = {
513   PROC(null,		void,		void,		void,	void, 1),
514   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
515   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
516   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
517   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
518   PROC(granted,		testargs,	res,		args,	res, Ck+St),
519   PROC(test_msg,	testargs,	norep,		args,	void, 1),
520   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
521   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
522   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
523   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
524   PROC(test_res,	testres,	norep,		res,	void, 1),
525   PROC(lock_res,	lockres,	norep,		res,	void, 1),
526   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
527   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
528   PROC(granted_res,	res,		norep,		res,	void, 1),
529   /* statd callback */
530   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
531   PROC(none,		void,		void,		void,	void, 1),
532   PROC(none,		void,		void,		void,	void, 1),
533   PROC(none,		void,		void,		void,	void, 1),
534   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
535   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
536   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
537   PROC(free_all,	notify,		void,		args,	void, 0),
538 
539 };
540