xref: /openbmc/linux/fs/lockd/svcproc.c (revision 9d56dd3b083a3bec56e9da35ce07baca81030b03)
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/lockd/lockd.h>
15 #include <linux/lockd/share.h>
16 
17 #define NLMDBG_FACILITY		NLMDBG_CLIENT
18 
19 #ifdef CONFIG_LOCKD_V4
20 static __be32
21 cast_to_nlm(__be32 status, u32 vers)
22 {
23 	/* Note: status is assumed to be in network byte order !!! */
24 	if (vers != 4){
25 		switch (status) {
26 		case nlm_granted:
27 		case nlm_lck_denied:
28 		case nlm_lck_denied_nolocks:
29 		case nlm_lck_blocked:
30 		case nlm_lck_denied_grace_period:
31 		case nlm_drop_reply:
32 			break;
33 		case nlm4_deadlock:
34 			status = nlm_lck_denied;
35 			break;
36 		default:
37 			status = nlm_lck_denied_nolocks;
38 		}
39 	}
40 
41 	return (status);
42 }
43 #define	cast_status(status) (cast_to_nlm(status, rqstp->rq_vers))
44 #else
45 #define cast_status(status) (status)
46 #endif
47 
48 /*
49  * Obtain client and file from arguments
50  */
51 static __be32
52 nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
53 			struct nlm_host **hostp, struct nlm_file **filp)
54 {
55 	struct nlm_host		*host = NULL;
56 	struct nlm_file		*file = NULL;
57 	struct nlm_lock		*lock = &argp->lock;
58 	__be32			error = 0;
59 
60 	/* nfsd callbacks must have been installed for this procedure */
61 	if (!nlmsvc_ops)
62 		return nlm_lck_denied_nolocks;
63 
64 	/* Obtain host handle */
65 	if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
66 	 || (argp->monitor && nsm_monitor(host) < 0))
67 		goto no_locks;
68 	*hostp = host;
69 
70 	/* Obtain file pointer. Not used by FREE_ALL call. */
71 	if (filp != NULL) {
72 		if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 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 
84 no_locks:
85 	nlm_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  */
94 static __be32
95 nlmsvc_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  */
104 static __be32
105 nlmsvc_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 	nlm_release_host(host);
128 	nlm_release_file(file);
129 	return rc;
130 }
131 
132 static __be32
133 nlmsvc_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 	nlm_release_host(host);
170 	nlm_release_file(file);
171 	return rc;
172 }
173 
174 static __be32
175 nlmsvc_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 
181 	dprintk("lockd: CANCEL        called\n");
182 
183 	resp->cookie = argp->cookie;
184 
185 	/* Don't accept requests during grace period */
186 	if (locks_in_grace()) {
187 		resp->status = nlm_lck_denied_grace_period;
188 		return rpc_success;
189 	}
190 
191 	/* Obtain client and file */
192 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
193 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
194 
195 	/* Try to cancel request. */
196 	resp->status = cast_status(nlmsvc_cancel_blocked(file, &argp->lock));
197 
198 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
199 	nlm_release_host(host);
200 	nlm_release_file(file);
201 	return rpc_success;
202 }
203 
204 /*
205  * UNLOCK: release a lock
206  */
207 static __be32
208 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
209 				           struct nlm_res  *resp)
210 {
211 	struct nlm_host	*host;
212 	struct nlm_file	*file;
213 
214 	dprintk("lockd: UNLOCK        called\n");
215 
216 	resp->cookie = argp->cookie;
217 
218 	/* Don't accept new lock requests during grace period */
219 	if (locks_in_grace()) {
220 		resp->status = nlm_lck_denied_grace_period;
221 		return rpc_success;
222 	}
223 
224 	/* Obtain client and file */
225 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
226 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
227 
228 	/* Now try to remove the lock */
229 	resp->status = cast_status(nlmsvc_unlock(file, &argp->lock));
230 
231 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
232 	nlm_release_host(host);
233 	nlm_release_file(file);
234 	return rpc_success;
235 }
236 
237 /*
238  * GRANTED: A server calls us to tell that a process' lock request
239  * was granted
240  */
241 static __be32
242 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
243 				            struct nlm_res  *resp)
244 {
245 	resp->cookie = argp->cookie;
246 
247 	dprintk("lockd: GRANTED       called\n");
248 	resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
249 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
250 	return rpc_success;
251 }
252 
253 /*
254  * This is the generic lockd callback for async RPC calls
255  */
256 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
257 {
258 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
259 			-task->tk_status);
260 }
261 
262 static void nlmsvc_callback_release(void *data)
263 {
264 	lock_kernel();
265 	nlm_release_call(data);
266 	unlock_kernel();
267 }
268 
269 static const struct rpc_call_ops nlmsvc_callback_ops = {
270 	.rpc_call_done = nlmsvc_callback_exit,
271 	.rpc_release = nlmsvc_callback_release,
272 };
273 
274 /*
275  * `Async' versions of the above service routines. They aren't really,
276  * because we send the callback before the reply proper. I hope this
277  * doesn't break any clients.
278  */
279 static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
280 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
281 {
282 	struct nlm_host	*host;
283 	struct nlm_rqst	*call;
284 	__be32 stat;
285 
286 	host = nlmsvc_lookup_host(rqstp,
287 				  argp->lock.caller,
288 				  argp->lock.len);
289 	if (host == NULL)
290 		return rpc_system_err;
291 
292 	call = nlm_alloc_call(host);
293 	if (call == NULL)
294 		return rpc_system_err;
295 
296 	stat = func(rqstp, argp, &call->a_res);
297 	if (stat != 0) {
298 		nlm_release_call(call);
299 		return stat;
300 	}
301 
302 	call->a_flags = RPC_TASK_ASYNC;
303 	if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
304 		return rpc_system_err;
305 	return rpc_success;
306 }
307 
308 static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
309 					     void	     *resp)
310 {
311 	dprintk("lockd: TEST_MSG      called\n");
312 	return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
313 }
314 
315 static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
316 					     void	     *resp)
317 {
318 	dprintk("lockd: LOCK_MSG      called\n");
319 	return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
320 }
321 
322 static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
323 					       void	       *resp)
324 {
325 	dprintk("lockd: CANCEL_MSG    called\n");
326 	return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
327 }
328 
329 static __be32
330 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
331                                                void            *resp)
332 {
333 	dprintk("lockd: UNLOCK_MSG    called\n");
334 	return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
335 }
336 
337 static __be32
338 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
339                                                 void            *resp)
340 {
341 	dprintk("lockd: GRANTED_MSG   called\n");
342 	return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
343 }
344 
345 /*
346  * SHARE: create a DOS share or alter existing share.
347  */
348 static __be32
349 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
350 				          struct nlm_res  *resp)
351 {
352 	struct nlm_host	*host;
353 	struct nlm_file	*file;
354 
355 	dprintk("lockd: SHARE         called\n");
356 
357 	resp->cookie = argp->cookie;
358 
359 	/* Don't accept new lock requests during grace period */
360 	if (locks_in_grace() && !argp->reclaim) {
361 		resp->status = nlm_lck_denied_grace_period;
362 		return rpc_success;
363 	}
364 
365 	/* Obtain client and file */
366 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
367 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
368 
369 	/* Now try to create the share */
370 	resp->status = cast_status(nlmsvc_share_file(host, file, argp));
371 
372 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
373 	nlm_release_host(host);
374 	nlm_release_file(file);
375 	return rpc_success;
376 }
377 
378 /*
379  * UNSHARE: Release a DOS share.
380  */
381 static __be32
382 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
383 				            struct nlm_res  *resp)
384 {
385 	struct nlm_host	*host;
386 	struct nlm_file	*file;
387 
388 	dprintk("lockd: UNSHARE       called\n");
389 
390 	resp->cookie = argp->cookie;
391 
392 	/* Don't accept requests during grace period */
393 	if (locks_in_grace()) {
394 		resp->status = nlm_lck_denied_grace_period;
395 		return rpc_success;
396 	}
397 
398 	/* Obtain client and file */
399 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
400 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
401 
402 	/* Now try to unshare the file */
403 	resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
404 
405 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
406 	nlm_release_host(host);
407 	nlm_release_file(file);
408 	return rpc_success;
409 }
410 
411 /*
412  * NM_LOCK: Create an unmonitored lock
413  */
414 static __be32
415 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
416 				            struct nlm_res  *resp)
417 {
418 	dprintk("lockd: NM_LOCK       called\n");
419 
420 	argp->monitor = 0;		/* just clean the monitor flag */
421 	return nlmsvc_proc_lock(rqstp, argp, resp);
422 }
423 
424 /*
425  * FREE_ALL: Release all locks and shares held by client
426  */
427 static __be32
428 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
429 					     void            *resp)
430 {
431 	struct nlm_host	*host;
432 
433 	/* Obtain client */
434 	if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
435 		return rpc_success;
436 
437 	nlmsvc_free_host_resources(host);
438 	nlm_release_host(host);
439 	return rpc_success;
440 }
441 
442 /*
443  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
444  */
445 static __be32
446 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
447 					      void	        *resp)
448 {
449 	dprintk("lockd: SM_NOTIFY     called\n");
450 
451 	if (!nlm_privileged_requester(rqstp)) {
452 		char buf[RPC_MAX_ADDRBUFLEN];
453 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
454 				svc_print_addr(rqstp, buf, sizeof(buf)));
455 		return rpc_system_err;
456 	}
457 
458 	nlm_host_rebooted(argp);
459 	return rpc_success;
460 }
461 
462 /*
463  * client sent a GRANTED_RES, let's remove the associated block
464  */
465 static __be32
466 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
467                                                 void            *resp)
468 {
469 	if (!nlmsvc_ops)
470 		return rpc_success;
471 
472 	dprintk("lockd: GRANTED_RES   called\n");
473 
474 	nlmsvc_grant_reply(&argp->cookie, argp->status);
475 	return rpc_success;
476 }
477 
478 /*
479  * NLM Server procedures.
480  */
481 
482 #define nlmsvc_encode_norep	nlmsvc_encode_void
483 #define nlmsvc_decode_norep	nlmsvc_decode_void
484 #define nlmsvc_decode_testres	nlmsvc_decode_void
485 #define nlmsvc_decode_lockres	nlmsvc_decode_void
486 #define nlmsvc_decode_unlockres	nlmsvc_decode_void
487 #define nlmsvc_decode_cancelres	nlmsvc_decode_void
488 #define nlmsvc_decode_grantedres	nlmsvc_decode_void
489 
490 #define nlmsvc_proc_none	nlmsvc_proc_null
491 #define nlmsvc_proc_test_res	nlmsvc_proc_null
492 #define nlmsvc_proc_lock_res	nlmsvc_proc_null
493 #define nlmsvc_proc_cancel_res	nlmsvc_proc_null
494 #define nlmsvc_proc_unlock_res	nlmsvc_proc_null
495 
496 struct nlm_void			{ int dummy; };
497 
498 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
499  { .pc_func	= (svc_procfunc) nlmsvc_proc_##name,	\
500    .pc_decode	= (kxdrproc_t) nlmsvc_decode_##xargt,	\
501    .pc_encode	= (kxdrproc_t) nlmsvc_encode_##xrest,	\
502    .pc_release	= NULL,					\
503    .pc_argsize	= sizeof(struct nlm_##argt),		\
504    .pc_ressize	= sizeof(struct nlm_##rest),		\
505    .pc_xdrressize = respsize,				\
506  }
507 
508 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
509 #define	St	1				/* status */
510 #define	No	(1+1024/4)			/* Net Obj */
511 #define	Rg	2				/* range - offset + size */
512 
513 struct svc_procedure		nlmsvc_procedures[] = {
514   PROC(null,		void,		void,		void,	void, 1),
515   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
516   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
517   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
518   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
519   PROC(granted,		testargs,	res,		args,	res, Ck+St),
520   PROC(test_msg,	testargs,	norep,		args,	void, 1),
521   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
522   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
523   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
524   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
525   PROC(test_res,	testres,	norep,		res,	void, 1),
526   PROC(lock_res,	lockres,	norep,		res,	void, 1),
527   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
528   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
529   PROC(granted_res,	res,		norep,		res,	void, 1),
530   /* statd callback */
531   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
532   PROC(none,		void,		void,		void,	void, 1),
533   PROC(none,		void,		void,		void,	void, 1),
534   PROC(none,		void,		void,		void,	void, 1),
535   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
536   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
537   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
538   PROC(free_all,	notify,		void,		args,	void, 0),
539 
540 };
541