xref: /openbmc/linux/fs/lockd/svcproc.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 
15 #define NLMDBG_FACILITY		NLMDBG_CLIENT
16 
17 #ifdef CONFIG_LOCKD_V4
18 static __be32
19 cast_to_nlm(__be32 status, u32 vers)
20 {
21 	/* Note: status is assumed to be in network byte order !!! */
22 	if (vers != 4){
23 		switch (status) {
24 		case nlm_granted:
25 		case nlm_lck_denied:
26 		case nlm_lck_denied_nolocks:
27 		case nlm_lck_blocked:
28 		case nlm_lck_denied_grace_period:
29 		case nlm_drop_reply:
30 			break;
31 		case nlm4_deadlock:
32 			status = nlm_lck_denied;
33 			break;
34 		default:
35 			status = nlm_lck_denied_nolocks;
36 		}
37 	}
38 
39 	return (status);
40 }
41 #define	cast_status(status) (cast_to_nlm(status, rqstp->rq_vers))
42 #else
43 #define cast_status(status) (status)
44 #endif
45 
46 /*
47  * Obtain client and file from arguments
48  */
49 static __be32
50 nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
51 			struct nlm_host **hostp, struct nlm_file **filp)
52 {
53 	struct nlm_host		*host = NULL;
54 	struct nlm_file		*file = NULL;
55 	struct nlm_lock		*lock = &argp->lock;
56 	__be32			error = 0;
57 
58 	/* nfsd callbacks must have been installed for this procedure */
59 	if (!nlmsvc_ops)
60 		return nlm_lck_denied_nolocks;
61 
62 	/* Obtain host handle */
63 	if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
64 	 || (argp->monitor && nsm_monitor(host) < 0))
65 		goto no_locks;
66 	*hostp = host;
67 
68 	/* Obtain file pointer. Not used by FREE_ALL call. */
69 	if (filp != NULL) {
70 		if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
71 			goto no_locks;
72 		*filp = file;
73 
74 		/* Set up the missing parts of the file_lock structure */
75 		lock->fl.fl_file  = file->f_file;
76 		lock->fl.fl_owner = (fl_owner_t) host;
77 		lock->fl.fl_lmops = &nlmsvc_lock_operations;
78 	}
79 
80 	return 0;
81 
82 no_locks:
83 	nlm_release_host(host);
84 	if (error)
85 		return error;
86 	return nlm_lck_denied_nolocks;
87 }
88 
89 /*
90  * NULL: Test for presence of service
91  */
92 static __be32
93 nlmsvc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
94 {
95 	dprintk("lockd: NULL          called\n");
96 	return rpc_success;
97 }
98 
99 /*
100  * TEST: Check for conflicting lock
101  */
102 static __be32
103 nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
104 				         struct nlm_res  *resp)
105 {
106 	struct nlm_host	*host;
107 	struct nlm_file	*file;
108 	__be32 rc = rpc_success;
109 
110 	dprintk("lockd: TEST          called\n");
111 	resp->cookie = argp->cookie;
112 
113 	/* Obtain client and file */
114 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
115 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
116 
117 	/* Now check for conflicting locks */
118 	resp->status = cast_status(nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie));
119 	if (resp->status == nlm_drop_reply)
120 		rc = rpc_drop_reply;
121 	else
122 		dprintk("lockd: TEST          status %d vers %d\n",
123 			ntohl(resp->status), rqstp->rq_vers);
124 
125 	nlm_release_host(host);
126 	nlm_release_file(file);
127 	return rc;
128 }
129 
130 static __be32
131 nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
132 				         struct nlm_res  *resp)
133 {
134 	struct nlm_host	*host;
135 	struct nlm_file	*file;
136 	__be32 rc = rpc_success;
137 
138 	dprintk("lockd: LOCK          called\n");
139 
140 	resp->cookie = argp->cookie;
141 
142 	/* Obtain client and file */
143 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
144 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
145 
146 #if 0
147 	/* If supplied state doesn't match current state, we assume it's
148 	 * an old request that time-warped somehow. Any error return would
149 	 * do in this case because it's irrelevant anyway.
150 	 *
151 	 * NB: We don't retrieve the remote host's state yet.
152 	 */
153 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
154 		resp->status = nlm_lck_denied_nolocks;
155 	} else
156 #endif
157 
158 	/* Now try to lock the file */
159 	resp->status = cast_status(nlmsvc_lock(rqstp, file, host, &argp->lock,
160 					       argp->block, &argp->cookie,
161 					       argp->reclaim));
162 	if (resp->status == nlm_drop_reply)
163 		rc = rpc_drop_reply;
164 	else
165 		dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
166 
167 	nlm_release_host(host);
168 	nlm_release_file(file);
169 	return rc;
170 }
171 
172 static __be32
173 nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
174 				           struct nlm_res  *resp)
175 {
176 	struct nlm_host	*host;
177 	struct nlm_file	*file;
178 
179 	dprintk("lockd: CANCEL        called\n");
180 
181 	resp->cookie = argp->cookie;
182 
183 	/* Don't accept requests during grace period */
184 	if (locks_in_grace()) {
185 		resp->status = nlm_lck_denied_grace_period;
186 		return rpc_success;
187 	}
188 
189 	/* Obtain client and file */
190 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
191 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
192 
193 	/* Try to cancel request. */
194 	resp->status = cast_status(nlmsvc_cancel_blocked(file, &argp->lock));
195 
196 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
197 	nlm_release_host(host);
198 	nlm_release_file(file);
199 	return rpc_success;
200 }
201 
202 /*
203  * UNLOCK: release a lock
204  */
205 static __be32
206 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
207 				           struct nlm_res  *resp)
208 {
209 	struct nlm_host	*host;
210 	struct nlm_file	*file;
211 
212 	dprintk("lockd: UNLOCK        called\n");
213 
214 	resp->cookie = argp->cookie;
215 
216 	/* Don't accept new lock requests during grace period */
217 	if (locks_in_grace()) {
218 		resp->status = nlm_lck_denied_grace_period;
219 		return rpc_success;
220 	}
221 
222 	/* Obtain client and file */
223 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
224 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
225 
226 	/* Now try to remove the lock */
227 	resp->status = cast_status(nlmsvc_unlock(file, &argp->lock));
228 
229 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
230 	nlm_release_host(host);
231 	nlm_release_file(file);
232 	return rpc_success;
233 }
234 
235 /*
236  * GRANTED: A server calls us to tell that a process' lock request
237  * was granted
238  */
239 static __be32
240 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
241 				            struct nlm_res  *resp)
242 {
243 	resp->cookie = argp->cookie;
244 
245 	dprintk("lockd: GRANTED       called\n");
246 	resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
247 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
248 	return rpc_success;
249 }
250 
251 /*
252  * This is the generic lockd callback for async RPC calls
253  */
254 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
255 {
256 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
257 			-task->tk_status);
258 }
259 
260 static void nlmsvc_callback_release(void *data)
261 {
262 	nlm_release_call(data);
263 }
264 
265 static const struct rpc_call_ops nlmsvc_callback_ops = {
266 	.rpc_call_done = nlmsvc_callback_exit,
267 	.rpc_release = nlmsvc_callback_release,
268 };
269 
270 /*
271  * `Async' versions of the above service routines. They aren't really,
272  * because we send the callback before the reply proper. I hope this
273  * doesn't break any clients.
274  */
275 static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
276 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
277 {
278 	struct nlm_host	*host;
279 	struct nlm_rqst	*call;
280 	__be32 stat;
281 
282 	host = nlmsvc_lookup_host(rqstp,
283 				  argp->lock.caller,
284 				  argp->lock.len);
285 	if (host == NULL)
286 		return rpc_system_err;
287 
288 	call = nlm_alloc_call(host);
289 	if (call == NULL)
290 		return rpc_system_err;
291 
292 	stat = func(rqstp, argp, &call->a_res);
293 	if (stat != 0) {
294 		nlm_release_call(call);
295 		return stat;
296 	}
297 
298 	call->a_flags = RPC_TASK_ASYNC;
299 	if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
300 		return rpc_system_err;
301 	return rpc_success;
302 }
303 
304 static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
305 					     void	     *resp)
306 {
307 	dprintk("lockd: TEST_MSG      called\n");
308 	return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
309 }
310 
311 static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
312 					     void	     *resp)
313 {
314 	dprintk("lockd: LOCK_MSG      called\n");
315 	return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
316 }
317 
318 static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
319 					       void	       *resp)
320 {
321 	dprintk("lockd: CANCEL_MSG    called\n");
322 	return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
323 }
324 
325 static __be32
326 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
327                                                void            *resp)
328 {
329 	dprintk("lockd: UNLOCK_MSG    called\n");
330 	return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
331 }
332 
333 static __be32
334 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
335                                                 void            *resp)
336 {
337 	dprintk("lockd: GRANTED_MSG   called\n");
338 	return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
339 }
340 
341 /*
342  * SHARE: create a DOS share or alter existing share.
343  */
344 static __be32
345 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
346 				          struct nlm_res  *resp)
347 {
348 	struct nlm_host	*host;
349 	struct nlm_file	*file;
350 
351 	dprintk("lockd: SHARE         called\n");
352 
353 	resp->cookie = argp->cookie;
354 
355 	/* Don't accept new lock requests during grace period */
356 	if (locks_in_grace() && !argp->reclaim) {
357 		resp->status = nlm_lck_denied_grace_period;
358 		return rpc_success;
359 	}
360 
361 	/* Obtain client and file */
362 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
363 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
364 
365 	/* Now try to create the share */
366 	resp->status = cast_status(nlmsvc_share_file(host, file, argp));
367 
368 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
369 	nlm_release_host(host);
370 	nlm_release_file(file);
371 	return rpc_success;
372 }
373 
374 /*
375  * UNSHARE: Release a DOS share.
376  */
377 static __be32
378 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
379 				            struct nlm_res  *resp)
380 {
381 	struct nlm_host	*host;
382 	struct nlm_file	*file;
383 
384 	dprintk("lockd: UNSHARE       called\n");
385 
386 	resp->cookie = argp->cookie;
387 
388 	/* Don't accept requests during grace period */
389 	if (locks_in_grace()) {
390 		resp->status = nlm_lck_denied_grace_period;
391 		return rpc_success;
392 	}
393 
394 	/* Obtain client and file */
395 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
396 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
397 
398 	/* Now try to unshare the file */
399 	resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
400 
401 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
402 	nlm_release_host(host);
403 	nlm_release_file(file);
404 	return rpc_success;
405 }
406 
407 /*
408  * NM_LOCK: Create an unmonitored lock
409  */
410 static __be32
411 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
412 				            struct nlm_res  *resp)
413 {
414 	dprintk("lockd: NM_LOCK       called\n");
415 
416 	argp->monitor = 0;		/* just clean the monitor flag */
417 	return nlmsvc_proc_lock(rqstp, argp, resp);
418 }
419 
420 /*
421  * FREE_ALL: Release all locks and shares held by client
422  */
423 static __be32
424 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
425 					     void            *resp)
426 {
427 	struct nlm_host	*host;
428 
429 	/* Obtain client */
430 	if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
431 		return rpc_success;
432 
433 	nlmsvc_free_host_resources(host);
434 	nlm_release_host(host);
435 	return rpc_success;
436 }
437 
438 /*
439  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
440  */
441 static __be32
442 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
443 					      void	        *resp)
444 {
445 	dprintk("lockd: SM_NOTIFY     called\n");
446 
447 	if (!nlm_privileged_requester(rqstp)) {
448 		char buf[RPC_MAX_ADDRBUFLEN];
449 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
450 				svc_print_addr(rqstp, buf, sizeof(buf)));
451 		return rpc_system_err;
452 	}
453 
454 	nlm_host_rebooted(argp);
455 	return rpc_success;
456 }
457 
458 /*
459  * client sent a GRANTED_RES, let's remove the associated block
460  */
461 static __be32
462 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
463                                                 void            *resp)
464 {
465 	if (!nlmsvc_ops)
466 		return rpc_success;
467 
468 	dprintk("lockd: GRANTED_RES   called\n");
469 
470 	nlmsvc_grant_reply(&argp->cookie, argp->status);
471 	return rpc_success;
472 }
473 
474 /*
475  * NLM Server procedures.
476  */
477 
478 #define nlmsvc_encode_norep	nlmsvc_encode_void
479 #define nlmsvc_decode_norep	nlmsvc_decode_void
480 #define nlmsvc_decode_testres	nlmsvc_decode_void
481 #define nlmsvc_decode_lockres	nlmsvc_decode_void
482 #define nlmsvc_decode_unlockres	nlmsvc_decode_void
483 #define nlmsvc_decode_cancelres	nlmsvc_decode_void
484 #define nlmsvc_decode_grantedres	nlmsvc_decode_void
485 
486 #define nlmsvc_proc_none	nlmsvc_proc_null
487 #define nlmsvc_proc_test_res	nlmsvc_proc_null
488 #define nlmsvc_proc_lock_res	nlmsvc_proc_null
489 #define nlmsvc_proc_cancel_res	nlmsvc_proc_null
490 #define nlmsvc_proc_unlock_res	nlmsvc_proc_null
491 
492 struct nlm_void			{ int dummy; };
493 
494 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
495  { .pc_func	= (svc_procfunc) nlmsvc_proc_##name,	\
496    .pc_decode	= (kxdrproc_t) nlmsvc_decode_##xargt,	\
497    .pc_encode	= (kxdrproc_t) nlmsvc_encode_##xrest,	\
498    .pc_release	= NULL,					\
499    .pc_argsize	= sizeof(struct nlm_##argt),		\
500    .pc_ressize	= sizeof(struct nlm_##rest),		\
501    .pc_xdrressize = respsize,				\
502  }
503 
504 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
505 #define	St	1				/* status */
506 #define	No	(1+1024/4)			/* Net Obj */
507 #define	Rg	2				/* range - offset + size */
508 
509 struct svc_procedure		nlmsvc_procedures[] = {
510   PROC(null,		void,		void,		void,	void, 1),
511   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
512   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
513   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
514   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
515   PROC(granted,		testargs,	res,		args,	res, Ck+St),
516   PROC(test_msg,	testargs,	norep,		args,	void, 1),
517   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
518   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
519   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
520   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
521   PROC(test_res,	testres,	norep,		res,	void, 1),
522   PROC(lock_res,	lockres,	norep,		res,	void, 1),
523   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
524   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
525   PROC(granted_res,	res,		norep,		res,	void, 1),
526   /* statd callback */
527   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
528   PROC(none,		void,		void,		void,	void, 1),
529   PROC(none,		void,		void,		void,	void, 1),
530   PROC(none,		void,		void,		void,	void, 1),
531   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
532   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
533   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
534   PROC(free_all,	notify,		void,		args,	void, 0),
535 
536 };
537