xref: /openbmc/linux/fs/lockd/svcproc.c (revision 8569c914)
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/in.h>
14 #include <linux/sunrpc/svc.h>
15 #include <linux/sunrpc/clnt.h>
16 #include <linux/nfsd/nfsd.h>
17 #include <linux/lockd/lockd.h>
18 #include <linux/lockd/share.h>
19 #include <linux/lockd/sm_inter.h>
20 
21 
22 #define NLMDBG_FACILITY		NLMDBG_CLIENT
23 
24 #ifdef CONFIG_LOCKD_V4
25 static __be32
26 cast_to_nlm(__be32 status, u32 vers)
27 {
28 	/* Note: status is assumed to be in network byte order !!! */
29 	if (vers != 4){
30 		switch (status) {
31 		case nlm_granted:
32 		case nlm_lck_denied:
33 		case nlm_lck_denied_nolocks:
34 		case nlm_lck_blocked:
35 		case nlm_lck_denied_grace_period:
36 		case nlm_drop_reply:
37 			break;
38 		case nlm4_deadlock:
39 			status = nlm_lck_denied;
40 			break;
41 		default:
42 			status = nlm_lck_denied_nolocks;
43 		}
44 	}
45 
46 	return (status);
47 }
48 #define	cast_status(status) (cast_to_nlm(status, rqstp->rq_vers))
49 #else
50 #define cast_status(status) (status)
51 #endif
52 
53 /*
54  * Obtain client and file from arguments
55  */
56 static __be32
57 nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
58 			struct nlm_host **hostp, struct nlm_file **filp)
59 {
60 	struct nlm_host		*host = NULL;
61 	struct nlm_file		*file = NULL;
62 	struct nlm_lock		*lock = &argp->lock;
63 	__be32			error = 0;
64 
65 	/* nfsd callbacks must have been installed for this procedure */
66 	if (!nlmsvc_ops)
67 		return nlm_lck_denied_nolocks;
68 
69 	/* Obtain host handle */
70 	if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
71 	 || (argp->monitor && nsm_monitor(host) < 0))
72 		goto no_locks;
73 	*hostp = host;
74 
75 	/* Obtain file pointer. Not used by FREE_ALL call. */
76 	if (filp != NULL) {
77 		if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
78 			goto no_locks;
79 		*filp = file;
80 
81 		/* Set up the missing parts of the file_lock structure */
82 		lock->fl.fl_file  = file->f_file;
83 		lock->fl.fl_owner = (fl_owner_t) host;
84 		lock->fl.fl_lmops = &nlmsvc_lock_operations;
85 	}
86 
87 	return 0;
88 
89 no_locks:
90 	nlm_release_host(host);
91 	if (error)
92 		return error;
93 	return nlm_lck_denied_nolocks;
94 }
95 
96 /*
97  * NULL: Test for presence of service
98  */
99 static __be32
100 nlmsvc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
101 {
102 	dprintk("lockd: NULL          called\n");
103 	return rpc_success;
104 }
105 
106 /*
107  * TEST: Check for conflicting lock
108  */
109 static __be32
110 nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
111 				         struct nlm_res  *resp)
112 {
113 	struct nlm_host	*host;
114 	struct nlm_file	*file;
115 	__be32 rc = rpc_success;
116 
117 	dprintk("lockd: TEST          called\n");
118 	resp->cookie = argp->cookie;
119 
120 	/* Obtain client and file */
121 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
122 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
123 
124 	/* Now check for conflicting locks */
125 	resp->status = cast_status(nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie));
126 	if (resp->status == nlm_drop_reply)
127 		rc = rpc_drop_reply;
128 	else
129 		dprintk("lockd: TEST          status %d vers %d\n",
130 			ntohl(resp->status), rqstp->rq_vers);
131 
132 	nlm_release_host(host);
133 	nlm_release_file(file);
134 	return rc;
135 }
136 
137 static __be32
138 nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
139 				         struct nlm_res  *resp)
140 {
141 	struct nlm_host	*host;
142 	struct nlm_file	*file;
143 	__be32 rc = rpc_success;
144 
145 	dprintk("lockd: LOCK          called\n");
146 
147 	resp->cookie = argp->cookie;
148 
149 	/* Obtain client and file */
150 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
151 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
152 
153 #if 0
154 	/* If supplied state doesn't match current state, we assume it's
155 	 * an old request that time-warped somehow. Any error return would
156 	 * do in this case because it's irrelevant anyway.
157 	 *
158 	 * NB: We don't retrieve the remote host's state yet.
159 	 */
160 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
161 		resp->status = nlm_lck_denied_nolocks;
162 	} else
163 #endif
164 
165 	/* Now try to lock the file */
166 	resp->status = cast_status(nlmsvc_lock(rqstp, file, host, &argp->lock,
167 					       argp->block, &argp->cookie,
168 					       argp->reclaim));
169 	if (resp->status == nlm_drop_reply)
170 		rc = rpc_drop_reply;
171 	else
172 		dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
173 
174 	nlm_release_host(host);
175 	nlm_release_file(file);
176 	return rc;
177 }
178 
179 static __be32
180 nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
181 				           struct nlm_res  *resp)
182 {
183 	struct nlm_host	*host;
184 	struct nlm_file	*file;
185 
186 	dprintk("lockd: CANCEL        called\n");
187 
188 	resp->cookie = argp->cookie;
189 
190 	/* Don't accept requests during grace period */
191 	if (locks_in_grace()) {
192 		resp->status = nlm_lck_denied_grace_period;
193 		return rpc_success;
194 	}
195 
196 	/* Obtain client and file */
197 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
198 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
199 
200 	/* Try to cancel request. */
201 	resp->status = cast_status(nlmsvc_cancel_blocked(file, &argp->lock));
202 
203 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
204 	nlm_release_host(host);
205 	nlm_release_file(file);
206 	return rpc_success;
207 }
208 
209 /*
210  * UNLOCK: release a lock
211  */
212 static __be32
213 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
214 				           struct nlm_res  *resp)
215 {
216 	struct nlm_host	*host;
217 	struct nlm_file	*file;
218 
219 	dprintk("lockd: UNLOCK        called\n");
220 
221 	resp->cookie = argp->cookie;
222 
223 	/* Don't accept new lock requests during grace period */
224 	if (locks_in_grace()) {
225 		resp->status = nlm_lck_denied_grace_period;
226 		return rpc_success;
227 	}
228 
229 	/* Obtain client and file */
230 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
231 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
232 
233 	/* Now try to remove the lock */
234 	resp->status = cast_status(nlmsvc_unlock(file, &argp->lock));
235 
236 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
237 	nlm_release_host(host);
238 	nlm_release_file(file);
239 	return rpc_success;
240 }
241 
242 /*
243  * GRANTED: A server calls us to tell that a process' lock request
244  * was granted
245  */
246 static __be32
247 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
248 				            struct nlm_res  *resp)
249 {
250 	resp->cookie = argp->cookie;
251 
252 	dprintk("lockd: GRANTED       called\n");
253 	resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
254 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
255 	return rpc_success;
256 }
257 
258 /*
259  * This is the generic lockd callback for async RPC calls
260  */
261 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
262 {
263 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
264 			-task->tk_status);
265 }
266 
267 static void nlmsvc_callback_release(void *data)
268 {
269 	lock_kernel();
270 	nlm_release_call(data);
271 	unlock_kernel();
272 }
273 
274 static const struct rpc_call_ops nlmsvc_callback_ops = {
275 	.rpc_call_done = nlmsvc_callback_exit,
276 	.rpc_release = nlmsvc_callback_release,
277 };
278 
279 /*
280  * `Async' versions of the above service routines. They aren't really,
281  * because we send the callback before the reply proper. I hope this
282  * doesn't break any clients.
283  */
284 static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
285 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
286 {
287 	struct nlm_host	*host;
288 	struct nlm_rqst	*call;
289 	__be32 stat;
290 
291 	host = nlmsvc_lookup_host(rqstp,
292 				  argp->lock.caller,
293 				  argp->lock.len);
294 	if (host == NULL)
295 		return rpc_system_err;
296 
297 	call = nlm_alloc_call(host);
298 	if (call == NULL)
299 		return rpc_system_err;
300 
301 	stat = func(rqstp, argp, &call->a_res);
302 	if (stat != 0) {
303 		nlm_release_call(call);
304 		return stat;
305 	}
306 
307 	call->a_flags = RPC_TASK_ASYNC;
308 	if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
309 		return rpc_system_err;
310 	return rpc_success;
311 }
312 
313 static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
314 					     void	     *resp)
315 {
316 	dprintk("lockd: TEST_MSG      called\n");
317 	return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
318 }
319 
320 static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
321 					     void	     *resp)
322 {
323 	dprintk("lockd: LOCK_MSG      called\n");
324 	return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
325 }
326 
327 static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
328 					       void	       *resp)
329 {
330 	dprintk("lockd: CANCEL_MSG    called\n");
331 	return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
332 }
333 
334 static __be32
335 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
336                                                void            *resp)
337 {
338 	dprintk("lockd: UNLOCK_MSG    called\n");
339 	return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
340 }
341 
342 static __be32
343 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
344                                                 void            *resp)
345 {
346 	dprintk("lockd: GRANTED_MSG   called\n");
347 	return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
348 }
349 
350 /*
351  * SHARE: create a DOS share or alter existing share.
352  */
353 static __be32
354 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
355 				          struct nlm_res  *resp)
356 {
357 	struct nlm_host	*host;
358 	struct nlm_file	*file;
359 
360 	dprintk("lockd: SHARE         called\n");
361 
362 	resp->cookie = argp->cookie;
363 
364 	/* Don't accept new lock requests during grace period */
365 	if (locks_in_grace() && !argp->reclaim) {
366 		resp->status = nlm_lck_denied_grace_period;
367 		return rpc_success;
368 	}
369 
370 	/* Obtain client and file */
371 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
372 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
373 
374 	/* Now try to create the share */
375 	resp->status = cast_status(nlmsvc_share_file(host, file, argp));
376 
377 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
378 	nlm_release_host(host);
379 	nlm_release_file(file);
380 	return rpc_success;
381 }
382 
383 /*
384  * UNSHARE: Release a DOS share.
385  */
386 static __be32
387 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
388 				            struct nlm_res  *resp)
389 {
390 	struct nlm_host	*host;
391 	struct nlm_file	*file;
392 
393 	dprintk("lockd: UNSHARE       called\n");
394 
395 	resp->cookie = argp->cookie;
396 
397 	/* Don't accept requests during grace period */
398 	if (locks_in_grace()) {
399 		resp->status = nlm_lck_denied_grace_period;
400 		return rpc_success;
401 	}
402 
403 	/* Obtain client and file */
404 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
405 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
406 
407 	/* Now try to unshare the file */
408 	resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
409 
410 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
411 	nlm_release_host(host);
412 	nlm_release_file(file);
413 	return rpc_success;
414 }
415 
416 /*
417  * NM_LOCK: Create an unmonitored lock
418  */
419 static __be32
420 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
421 				            struct nlm_res  *resp)
422 {
423 	dprintk("lockd: NM_LOCK       called\n");
424 
425 	argp->monitor = 0;		/* just clean the monitor flag */
426 	return nlmsvc_proc_lock(rqstp, argp, resp);
427 }
428 
429 /*
430  * FREE_ALL: Release all locks and shares held by client
431  */
432 static __be32
433 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
434 					     void            *resp)
435 {
436 	struct nlm_host	*host;
437 
438 	/* Obtain client */
439 	if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
440 		return rpc_success;
441 
442 	nlmsvc_free_host_resources(host);
443 	nlm_release_host(host);
444 	return rpc_success;
445 }
446 
447 /*
448  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
449  */
450 static __be32
451 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
452 					      void	        *resp)
453 {
454 	struct sockaddr_in	saddr;
455 
456 	dprintk("lockd: SM_NOTIFY     called\n");
457 
458 	if (!nlm_privileged_requester(rqstp)) {
459 		char buf[RPC_MAX_ADDRBUFLEN];
460 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
461 				svc_print_addr(rqstp, buf, sizeof(buf)));
462 		return rpc_system_err;
463 	}
464 
465 	/* Obtain the host pointer for this NFS server and try to
466 	 * reclaim all locks we hold on this server.
467 	 */
468 	memset(&saddr, 0, sizeof(saddr));
469 	saddr.sin_addr.s_addr = argp->addr;
470 	nlm_host_rebooted(&saddr, argp->mon, argp->len, argp->state);
471 
472 	return rpc_success;
473 }
474 
475 /*
476  * client sent a GRANTED_RES, let's remove the associated block
477  */
478 static __be32
479 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
480                                                 void            *resp)
481 {
482 	if (!nlmsvc_ops)
483 		return rpc_success;
484 
485 	dprintk("lockd: GRANTED_RES   called\n");
486 
487 	nlmsvc_grant_reply(&argp->cookie, argp->status);
488 	return rpc_success;
489 }
490 
491 /*
492  * NLM Server procedures.
493  */
494 
495 #define nlmsvc_encode_norep	nlmsvc_encode_void
496 #define nlmsvc_decode_norep	nlmsvc_decode_void
497 #define nlmsvc_decode_testres	nlmsvc_decode_void
498 #define nlmsvc_decode_lockres	nlmsvc_decode_void
499 #define nlmsvc_decode_unlockres	nlmsvc_decode_void
500 #define nlmsvc_decode_cancelres	nlmsvc_decode_void
501 #define nlmsvc_decode_grantedres	nlmsvc_decode_void
502 
503 #define nlmsvc_proc_none	nlmsvc_proc_null
504 #define nlmsvc_proc_test_res	nlmsvc_proc_null
505 #define nlmsvc_proc_lock_res	nlmsvc_proc_null
506 #define nlmsvc_proc_cancel_res	nlmsvc_proc_null
507 #define nlmsvc_proc_unlock_res	nlmsvc_proc_null
508 
509 struct nlm_void			{ int dummy; };
510 
511 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
512  { .pc_func	= (svc_procfunc) nlmsvc_proc_##name,	\
513    .pc_decode	= (kxdrproc_t) nlmsvc_decode_##xargt,	\
514    .pc_encode	= (kxdrproc_t) nlmsvc_encode_##xrest,	\
515    .pc_release	= NULL,					\
516    .pc_argsize	= sizeof(struct nlm_##argt),		\
517    .pc_ressize	= sizeof(struct nlm_##rest),		\
518    .pc_xdrressize = respsize,				\
519  }
520 
521 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
522 #define	St	1				/* status */
523 #define	No	(1+1024/4)			/* Net Obj */
524 #define	Rg	2				/* range - offset + size */
525 
526 struct svc_procedure		nlmsvc_procedures[] = {
527   PROC(null,		void,		void,		void,	void, 1),
528   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
529   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
530   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
531   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
532   PROC(granted,		testargs,	res,		args,	res, Ck+St),
533   PROC(test_msg,	testargs,	norep,		args,	void, 1),
534   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
535   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
536   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
537   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
538   PROC(test_res,	testres,	norep,		res,	void, 1),
539   PROC(lock_res,	lockres,	norep,		res,	void, 1),
540   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
541   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
542   PROC(granted_res,	res,		norep,		res,	void, 1),
543   /* statd callback */
544   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
545   PROC(none,		void,		void,		void,	void, 1),
546   PROC(none,		void,		void,		void,	void, 1),
547   PROC(none,		void,		void,		void,	void, 1),
548   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
549   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
550   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
551   PROC(free_all,	notify,		void,		args,	void, 0),
552 
553 };
554