xref: /openbmc/linux/fs/lockd/svcproc.c (revision e8e0929d)
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/slab.h>
13 #include <linux/smp_lock.h>
14 #include <linux/in.h>
15 #include <linux/sunrpc/svc.h>
16 #include <linux/sunrpc/clnt.h>
17 #include <linux/nfsd/nfsd.h>
18 #include <linux/lockd/lockd.h>
19 #include <linux/lockd/share.h>
20 
21 #define NLMDBG_FACILITY		NLMDBG_CLIENT
22 
23 #ifdef CONFIG_LOCKD_V4
24 static __be32
25 cast_to_nlm(__be32 status, u32 vers)
26 {
27 	/* Note: status is assumed to be in network byte order !!! */
28 	if (vers != 4){
29 		switch (status) {
30 		case nlm_granted:
31 		case nlm_lck_denied:
32 		case nlm_lck_denied_nolocks:
33 		case nlm_lck_blocked:
34 		case nlm_lck_denied_grace_period:
35 		case nlm_drop_reply:
36 			break;
37 		case nlm4_deadlock:
38 			status = nlm_lck_denied;
39 			break;
40 		default:
41 			status = nlm_lck_denied_nolocks;
42 		}
43 	}
44 
45 	return (status);
46 }
47 #define	cast_status(status) (cast_to_nlm(status, rqstp->rq_vers))
48 #else
49 #define cast_status(status) (status)
50 #endif
51 
52 /*
53  * Obtain client and file from arguments
54  */
55 static __be32
56 nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
57 			struct nlm_host **hostp, struct nlm_file **filp)
58 {
59 	struct nlm_host		*host = NULL;
60 	struct nlm_file		*file = NULL;
61 	struct nlm_lock		*lock = &argp->lock;
62 	__be32			error = 0;
63 
64 	/* nfsd callbacks must have been installed for this procedure */
65 	if (!nlmsvc_ops)
66 		return nlm_lck_denied_nolocks;
67 
68 	/* Obtain host handle */
69 	if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
70 	 || (argp->monitor && nsm_monitor(host) < 0))
71 		goto no_locks;
72 	*hostp = host;
73 
74 	/* Obtain file pointer. Not used by FREE_ALL call. */
75 	if (filp != NULL) {
76 		if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
77 			goto no_locks;
78 		*filp = file;
79 
80 		/* Set up the missing parts of the file_lock structure */
81 		lock->fl.fl_file  = file->f_file;
82 		lock->fl.fl_owner = (fl_owner_t) host;
83 		lock->fl.fl_lmops = &nlmsvc_lock_operations;
84 	}
85 
86 	return 0;
87 
88 no_locks:
89 	nlm_release_host(host);
90 	if (error)
91 		return error;
92 	return nlm_lck_denied_nolocks;
93 }
94 
95 /*
96  * NULL: Test for presence of service
97  */
98 static __be32
99 nlmsvc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
100 {
101 	dprintk("lockd: NULL          called\n");
102 	return rpc_success;
103 }
104 
105 /*
106  * TEST: Check for conflicting lock
107  */
108 static __be32
109 nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
110 				         struct nlm_res  *resp)
111 {
112 	struct nlm_host	*host;
113 	struct nlm_file	*file;
114 	__be32 rc = rpc_success;
115 
116 	dprintk("lockd: TEST          called\n");
117 	resp->cookie = argp->cookie;
118 
119 	/* Obtain client and file */
120 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
121 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
122 
123 	/* Now check for conflicting locks */
124 	resp->status = cast_status(nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie));
125 	if (resp->status == nlm_drop_reply)
126 		rc = rpc_drop_reply;
127 	else
128 		dprintk("lockd: TEST          status %d vers %d\n",
129 			ntohl(resp->status), rqstp->rq_vers);
130 
131 	nlm_release_host(host);
132 	nlm_release_file(file);
133 	return rc;
134 }
135 
136 static __be32
137 nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
138 				         struct nlm_res  *resp)
139 {
140 	struct nlm_host	*host;
141 	struct nlm_file	*file;
142 	__be32 rc = rpc_success;
143 
144 	dprintk("lockd: LOCK          called\n");
145 
146 	resp->cookie = argp->cookie;
147 
148 	/* Obtain client and file */
149 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
150 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
151 
152 #if 0
153 	/* If supplied state doesn't match current state, we assume it's
154 	 * an old request that time-warped somehow. Any error return would
155 	 * do in this case because it's irrelevant anyway.
156 	 *
157 	 * NB: We don't retrieve the remote host's state yet.
158 	 */
159 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
160 		resp->status = nlm_lck_denied_nolocks;
161 	} else
162 #endif
163 
164 	/* Now try to lock the file */
165 	resp->status = cast_status(nlmsvc_lock(rqstp, file, host, &argp->lock,
166 					       argp->block, &argp->cookie,
167 					       argp->reclaim));
168 	if (resp->status == nlm_drop_reply)
169 		rc = rpc_drop_reply;
170 	else
171 		dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
172 
173 	nlm_release_host(host);
174 	nlm_release_file(file);
175 	return rc;
176 }
177 
178 static __be32
179 nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
180 				           struct nlm_res  *resp)
181 {
182 	struct nlm_host	*host;
183 	struct nlm_file	*file;
184 
185 	dprintk("lockd: CANCEL        called\n");
186 
187 	resp->cookie = argp->cookie;
188 
189 	/* Don't accept requests during grace period */
190 	if (locks_in_grace()) {
191 		resp->status = nlm_lck_denied_grace_period;
192 		return rpc_success;
193 	}
194 
195 	/* Obtain client and file */
196 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
197 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
198 
199 	/* Try to cancel request. */
200 	resp->status = cast_status(nlmsvc_cancel_blocked(file, &argp->lock));
201 
202 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
203 	nlm_release_host(host);
204 	nlm_release_file(file);
205 	return rpc_success;
206 }
207 
208 /*
209  * UNLOCK: release a lock
210  */
211 static __be32
212 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
213 				           struct nlm_res  *resp)
214 {
215 	struct nlm_host	*host;
216 	struct nlm_file	*file;
217 
218 	dprintk("lockd: UNLOCK        called\n");
219 
220 	resp->cookie = argp->cookie;
221 
222 	/* Don't accept new lock requests during grace period */
223 	if (locks_in_grace()) {
224 		resp->status = nlm_lck_denied_grace_period;
225 		return rpc_success;
226 	}
227 
228 	/* Obtain client and file */
229 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
230 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
231 
232 	/* Now try to remove the lock */
233 	resp->status = cast_status(nlmsvc_unlock(file, &argp->lock));
234 
235 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
236 	nlm_release_host(host);
237 	nlm_release_file(file);
238 	return rpc_success;
239 }
240 
241 /*
242  * GRANTED: A server calls us to tell that a process' lock request
243  * was granted
244  */
245 static __be32
246 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
247 				            struct nlm_res  *resp)
248 {
249 	resp->cookie = argp->cookie;
250 
251 	dprintk("lockd: GRANTED       called\n");
252 	resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
253 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
254 	return rpc_success;
255 }
256 
257 /*
258  * This is the generic lockd callback for async RPC calls
259  */
260 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
261 {
262 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
263 			-task->tk_status);
264 }
265 
266 static void nlmsvc_callback_release(void *data)
267 {
268 	lock_kernel();
269 	nlm_release_call(data);
270 	unlock_kernel();
271 }
272 
273 static const struct rpc_call_ops nlmsvc_callback_ops = {
274 	.rpc_call_done = nlmsvc_callback_exit,
275 	.rpc_release = nlmsvc_callback_release,
276 };
277 
278 /*
279  * `Async' versions of the above service routines. They aren't really,
280  * because we send the callback before the reply proper. I hope this
281  * doesn't break any clients.
282  */
283 static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
284 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
285 {
286 	struct nlm_host	*host;
287 	struct nlm_rqst	*call;
288 	__be32 stat;
289 
290 	host = nlmsvc_lookup_host(rqstp,
291 				  argp->lock.caller,
292 				  argp->lock.len);
293 	if (host == NULL)
294 		return rpc_system_err;
295 
296 	call = nlm_alloc_call(host);
297 	if (call == NULL)
298 		return rpc_system_err;
299 
300 	stat = func(rqstp, argp, &call->a_res);
301 	if (stat != 0) {
302 		nlm_release_call(call);
303 		return stat;
304 	}
305 
306 	call->a_flags = RPC_TASK_ASYNC;
307 	if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
308 		return rpc_system_err;
309 	return rpc_success;
310 }
311 
312 static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
313 					     void	     *resp)
314 {
315 	dprintk("lockd: TEST_MSG      called\n");
316 	return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
317 }
318 
319 static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
320 					     void	     *resp)
321 {
322 	dprintk("lockd: LOCK_MSG      called\n");
323 	return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
324 }
325 
326 static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
327 					       void	       *resp)
328 {
329 	dprintk("lockd: CANCEL_MSG    called\n");
330 	return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
331 }
332 
333 static __be32
334 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
335                                                void            *resp)
336 {
337 	dprintk("lockd: UNLOCK_MSG    called\n");
338 	return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
339 }
340 
341 static __be32
342 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
343                                                 void            *resp)
344 {
345 	dprintk("lockd: GRANTED_MSG   called\n");
346 	return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
347 }
348 
349 /*
350  * SHARE: create a DOS share or alter existing share.
351  */
352 static __be32
353 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
354 				          struct nlm_res  *resp)
355 {
356 	struct nlm_host	*host;
357 	struct nlm_file	*file;
358 
359 	dprintk("lockd: SHARE         called\n");
360 
361 	resp->cookie = argp->cookie;
362 
363 	/* Don't accept new lock requests during grace period */
364 	if (locks_in_grace() && !argp->reclaim) {
365 		resp->status = nlm_lck_denied_grace_period;
366 		return rpc_success;
367 	}
368 
369 	/* Obtain client and file */
370 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
371 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
372 
373 	/* Now try to create the share */
374 	resp->status = cast_status(nlmsvc_share_file(host, file, argp));
375 
376 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
377 	nlm_release_host(host);
378 	nlm_release_file(file);
379 	return rpc_success;
380 }
381 
382 /*
383  * UNSHARE: Release a DOS share.
384  */
385 static __be32
386 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
387 				            struct nlm_res  *resp)
388 {
389 	struct nlm_host	*host;
390 	struct nlm_file	*file;
391 
392 	dprintk("lockd: UNSHARE       called\n");
393 
394 	resp->cookie = argp->cookie;
395 
396 	/* Don't accept requests during grace period */
397 	if (locks_in_grace()) {
398 		resp->status = nlm_lck_denied_grace_period;
399 		return rpc_success;
400 	}
401 
402 	/* Obtain client and file */
403 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
404 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
405 
406 	/* Now try to unshare the file */
407 	resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
408 
409 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
410 	nlm_release_host(host);
411 	nlm_release_file(file);
412 	return rpc_success;
413 }
414 
415 /*
416  * NM_LOCK: Create an unmonitored lock
417  */
418 static __be32
419 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
420 				            struct nlm_res  *resp)
421 {
422 	dprintk("lockd: NM_LOCK       called\n");
423 
424 	argp->monitor = 0;		/* just clean the monitor flag */
425 	return nlmsvc_proc_lock(rqstp, argp, resp);
426 }
427 
428 /*
429  * FREE_ALL: Release all locks and shares held by client
430  */
431 static __be32
432 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
433 					     void            *resp)
434 {
435 	struct nlm_host	*host;
436 
437 	/* Obtain client */
438 	if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
439 		return rpc_success;
440 
441 	nlmsvc_free_host_resources(host);
442 	nlm_release_host(host);
443 	return rpc_success;
444 }
445 
446 /*
447  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
448  */
449 static __be32
450 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
451 					      void	        *resp)
452 {
453 	dprintk("lockd: SM_NOTIFY     called\n");
454 
455 	if (!nlm_privileged_requester(rqstp)) {
456 		char buf[RPC_MAX_ADDRBUFLEN];
457 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
458 				svc_print_addr(rqstp, buf, sizeof(buf)));
459 		return rpc_system_err;
460 	}
461 
462 	nlm_host_rebooted(argp);
463 	return rpc_success;
464 }
465 
466 /*
467  * client sent a GRANTED_RES, let's remove the associated block
468  */
469 static __be32
470 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
471                                                 void            *resp)
472 {
473 	if (!nlmsvc_ops)
474 		return rpc_success;
475 
476 	dprintk("lockd: GRANTED_RES   called\n");
477 
478 	nlmsvc_grant_reply(&argp->cookie, argp->status);
479 	return rpc_success;
480 }
481 
482 /*
483  * NLM Server procedures.
484  */
485 
486 #define nlmsvc_encode_norep	nlmsvc_encode_void
487 #define nlmsvc_decode_norep	nlmsvc_decode_void
488 #define nlmsvc_decode_testres	nlmsvc_decode_void
489 #define nlmsvc_decode_lockres	nlmsvc_decode_void
490 #define nlmsvc_decode_unlockres	nlmsvc_decode_void
491 #define nlmsvc_decode_cancelres	nlmsvc_decode_void
492 #define nlmsvc_decode_grantedres	nlmsvc_decode_void
493 
494 #define nlmsvc_proc_none	nlmsvc_proc_null
495 #define nlmsvc_proc_test_res	nlmsvc_proc_null
496 #define nlmsvc_proc_lock_res	nlmsvc_proc_null
497 #define nlmsvc_proc_cancel_res	nlmsvc_proc_null
498 #define nlmsvc_proc_unlock_res	nlmsvc_proc_null
499 
500 struct nlm_void			{ int dummy; };
501 
502 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
503  { .pc_func	= (svc_procfunc) nlmsvc_proc_##name,	\
504    .pc_decode	= (kxdrproc_t) nlmsvc_decode_##xargt,	\
505    .pc_encode	= (kxdrproc_t) nlmsvc_encode_##xrest,	\
506    .pc_release	= NULL,					\
507    .pc_argsize	= sizeof(struct nlm_##argt),		\
508    .pc_ressize	= sizeof(struct nlm_##rest),		\
509    .pc_xdrressize = respsize,				\
510  }
511 
512 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
513 #define	St	1				/* status */
514 #define	No	(1+1024/4)			/* Net Obj */
515 #define	Rg	2				/* range - offset + size */
516 
517 struct svc_procedure		nlmsvc_procedures[] = {
518   PROC(null,		void,		void,		void,	void, 1),
519   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
520   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
521   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
522   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
523   PROC(granted,		testargs,	res,		args,	res, Ck+St),
524   PROC(test_msg,	testargs,	norep,		args,	void, 1),
525   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
526   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
527   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
528   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
529   PROC(test_res,	testres,	norep,		res,	void, 1),
530   PROC(lock_res,	lockres,	norep,		res,	void, 1),
531   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
532   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
533   PROC(granted_res,	res,		norep,		res,	void, 1),
534   /* statd callback */
535   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
536   PROC(none,		void,		void,		void,	void, 1),
537   PROC(none,		void,		void,		void,	void, 1),
538   PROC(none,		void,		void,		void,	void, 1),
539   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
540   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
541   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
542   PROC(free_all,	notify,		void,		args,	void, 0),
543 
544 };
545