xref: /linux/fs/lockd/svcproc.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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/config.h>
11 #include <linux/types.h>
12 #include <linux/time.h>
13 #include <linux/slab.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 #include <linux/lockd/sm_inter.h>
21 
22 
23 #define NLMDBG_FACILITY		NLMDBG_CLIENT
24 
25 #ifdef CONFIG_LOCKD_V4
26 static u32
27 cast_to_nlm(u32 status, u32 vers)
28 {
29 	/* Note: status is assumed to be in network byte order !!! */
30 	if (vers != 4){
31 		switch (status) {
32 		case nlm_granted:
33 		case nlm_lck_denied:
34 		case nlm_lck_denied_nolocks:
35 		case nlm_lck_blocked:
36 		case nlm_lck_denied_grace_period:
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 u32
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 	u32			error;
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))
71 	 || (argp->monitor && !host->h_monitored && 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 	if (host)
91 		nlm_release_host(host);
92 	return nlm_lck_denied_nolocks;
93 }
94 
95 /*
96  * NULL: Test for presence of service
97  */
98 static int
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 int
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 
115 	dprintk("lockd: TEST          called\n");
116 	resp->cookie = argp->cookie;
117 
118 	/* Don't accept test requests during grace period */
119 	if (nlmsvc_grace_period) {
120 		resp->status = nlm_lck_denied_grace_period;
121 		return rpc_success;
122 	}
123 
124 	/* Obtain client and file */
125 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
126 		return rpc_success;
127 
128 	/* Now check for conflicting locks */
129 	resp->status = cast_status(nlmsvc_testlock(file, &argp->lock, &resp->lock));
130 
131 	dprintk("lockd: TEST          status %d vers %d\n",
132 		ntohl(resp->status), rqstp->rq_vers);
133 	nlm_release_host(host);
134 	nlm_release_file(file);
135 	return rpc_success;
136 }
137 
138 static int
139 nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
140 				         struct nlm_res  *resp)
141 {
142 	struct nlm_host	*host;
143 	struct nlm_file	*file;
144 
145 	dprintk("lockd: LOCK          called\n");
146 
147 	resp->cookie = argp->cookie;
148 
149 	/* Don't accept new lock requests during grace period */
150 	if (nlmsvc_grace_period && !argp->reclaim) {
151 		resp->status = nlm_lck_denied_grace_period;
152 		return rpc_success;
153 	}
154 
155 	/* Obtain client and file */
156 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
157 		return rpc_success;
158 
159 #if 0
160 	/* If supplied state doesn't match current state, we assume it's
161 	 * an old request that time-warped somehow. Any error return would
162 	 * do in this case because it's irrelevant anyway.
163 	 *
164 	 * NB: We don't retrieve the remote host's state yet.
165 	 */
166 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
167 		resp->status = nlm_lck_denied_nolocks;
168 	} else
169 #endif
170 
171 	/* Now try to lock the file */
172 	resp->status = cast_status(nlmsvc_lock(rqstp, file, &argp->lock,
173 					       argp->block, &argp->cookie));
174 
175 	dprintk("lockd: LOCK          status %d\n", ntohl(resp->status));
176 	nlm_release_host(host);
177 	nlm_release_file(file);
178 	return rpc_success;
179 }
180 
181 static int
182 nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
183 				           struct nlm_res  *resp)
184 {
185 	struct nlm_host	*host;
186 	struct nlm_file	*file;
187 
188 	dprintk("lockd: CANCEL        called\n");
189 
190 	resp->cookie = argp->cookie;
191 
192 	/* Don't accept requests during grace period */
193 	if (nlmsvc_grace_period) {
194 		resp->status = nlm_lck_denied_grace_period;
195 		return rpc_success;
196 	}
197 
198 	/* Obtain client and file */
199 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
200 		return rpc_success;
201 
202 	/* Try to cancel request. */
203 	resp->status = cast_status(nlmsvc_cancel_blocked(file, &argp->lock));
204 
205 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
206 	nlm_release_host(host);
207 	nlm_release_file(file);
208 	return rpc_success;
209 }
210 
211 /*
212  * UNLOCK: release a lock
213  */
214 static int
215 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
216 				           struct nlm_res  *resp)
217 {
218 	struct nlm_host	*host;
219 	struct nlm_file	*file;
220 
221 	dprintk("lockd: UNLOCK        called\n");
222 
223 	resp->cookie = argp->cookie;
224 
225 	/* Don't accept new lock requests during grace period */
226 	if (nlmsvc_grace_period) {
227 		resp->status = nlm_lck_denied_grace_period;
228 		return rpc_success;
229 	}
230 
231 	/* Obtain client and file */
232 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
233 		return rpc_success;
234 
235 	/* Now try to remove the lock */
236 	resp->status = cast_status(nlmsvc_unlock(file, &argp->lock));
237 
238 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
239 	nlm_release_host(host);
240 	nlm_release_file(file);
241 	return rpc_success;
242 }
243 
244 /*
245  * GRANTED: A server calls us to tell that a process' lock request
246  * was granted
247  */
248 static int
249 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
250 				            struct nlm_res  *resp)
251 {
252 	resp->cookie = argp->cookie;
253 
254 	dprintk("lockd: GRANTED       called\n");
255 	resp->status = nlmclnt_grant(&rqstp->rq_addr, &argp->lock);
256 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
257 	return rpc_success;
258 }
259 
260 /*
261  * This is the generic lockd callback for async RPC calls
262  */
263 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
264 {
265 	dprintk("lockd: %4d callback returned %d\n", task->tk_pid,
266 			-task->tk_status);
267 }
268 
269 static void nlmsvc_callback_release(void *data)
270 {
271 	nlm_release_call(data);
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 int nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
285 		int (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
286 {
287 	struct nlm_host	*host;
288 	struct nlm_rqst	*call;
289 	int stat;
290 
291 	host = nlmsvc_lookup_host(rqstp);
292 	if (host == NULL)
293 		return rpc_system_err;
294 
295 	call = nlm_alloc_call(host);
296 	if (call == NULL)
297 		return rpc_system_err;
298 
299 	stat = func(rqstp, argp, &call->a_res);
300 	if (stat != 0) {
301 		nlm_release_call(call);
302 		return stat;
303 	}
304 
305 	call->a_flags = RPC_TASK_ASYNC;
306 	if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
307 		return rpc_system_err;
308 	return rpc_success;
309 }
310 
311 static int nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
312 					     void	     *resp)
313 {
314 	dprintk("lockd: TEST_MSG      called\n");
315 	return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
316 }
317 
318 static int nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
319 					     void	     *resp)
320 {
321 	dprintk("lockd: LOCK_MSG      called\n");
322 	return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
323 }
324 
325 static int nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
326 					       void	       *resp)
327 {
328 	dprintk("lockd: CANCEL_MSG    called\n");
329 	return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
330 }
331 
332 static int
333 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
334                                                void            *resp)
335 {
336 	dprintk("lockd: UNLOCK_MSG    called\n");
337 	return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
338 }
339 
340 static int
341 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
342                                                 void            *resp)
343 {
344 	dprintk("lockd: GRANTED_MSG   called\n");
345 	return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
346 }
347 
348 /*
349  * SHARE: create a DOS share or alter existing share.
350  */
351 static int
352 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
353 				          struct nlm_res  *resp)
354 {
355 	struct nlm_host	*host;
356 	struct nlm_file	*file;
357 
358 	dprintk("lockd: SHARE         called\n");
359 
360 	resp->cookie = argp->cookie;
361 
362 	/* Don't accept new lock requests during grace period */
363 	if (nlmsvc_grace_period && !argp->reclaim) {
364 		resp->status = nlm_lck_denied_grace_period;
365 		return rpc_success;
366 	}
367 
368 	/* Obtain client and file */
369 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
370 		return rpc_success;
371 
372 	/* Now try to create the share */
373 	resp->status = cast_status(nlmsvc_share_file(host, file, argp));
374 
375 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
376 	nlm_release_host(host);
377 	nlm_release_file(file);
378 	return rpc_success;
379 }
380 
381 /*
382  * UNSHARE: Release a DOS share.
383  */
384 static int
385 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
386 				            struct nlm_res  *resp)
387 {
388 	struct nlm_host	*host;
389 	struct nlm_file	*file;
390 
391 	dprintk("lockd: UNSHARE       called\n");
392 
393 	resp->cookie = argp->cookie;
394 
395 	/* Don't accept requests during grace period */
396 	if (nlmsvc_grace_period) {
397 		resp->status = nlm_lck_denied_grace_period;
398 		return rpc_success;
399 	}
400 
401 	/* Obtain client and file */
402 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
403 		return rpc_success;
404 
405 	/* Now try to unshare the file */
406 	resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
407 
408 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
409 	nlm_release_host(host);
410 	nlm_release_file(file);
411 	return rpc_success;
412 }
413 
414 /*
415  * NM_LOCK: Create an unmonitored lock
416  */
417 static int
418 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
419 				            struct nlm_res  *resp)
420 {
421 	dprintk("lockd: NM_LOCK       called\n");
422 
423 	argp->monitor = 0;		/* just clean the monitor flag */
424 	return nlmsvc_proc_lock(rqstp, argp, resp);
425 }
426 
427 /*
428  * FREE_ALL: Release all locks and shares held by client
429  */
430 static int
431 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
432 					     void            *resp)
433 {
434 	struct nlm_host	*host;
435 
436 	/* Obtain client */
437 	if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
438 		return rpc_success;
439 
440 	nlmsvc_free_host_resources(host);
441 	nlm_release_host(host);
442 	return rpc_success;
443 }
444 
445 /*
446  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
447  */
448 static int
449 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
450 					      void	        *resp)
451 {
452 	struct sockaddr_in	saddr = rqstp->rq_addr;
453 	int			vers = argp->vers;
454 	int			prot = argp->proto >> 1;
455 	struct nlm_host		*host;
456 
457 	dprintk("lockd: SM_NOTIFY     called\n");
458 	if (saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)
459 	 || ntohs(saddr.sin_port) >= 1024) {
460 		printk(KERN_WARNING
461 			"lockd: rejected NSM callback from %08x:%d\n",
462 			ntohl(rqstp->rq_addr.sin_addr.s_addr),
463 			ntohs(rqstp->rq_addr.sin_port));
464 		return rpc_system_err;
465 	}
466 
467 	/* Obtain the host pointer for this NFS server and try to
468 	 * reclaim all locks we hold on this server.
469 	 */
470 	saddr.sin_addr.s_addr = argp->addr;
471 	if ((argp->proto & 1)==0) {
472 		if ((host = nlmclnt_lookup_host(&saddr, prot, vers)) != NULL) {
473 			nlmclnt_recovery(host, argp->state);
474 			nlm_release_host(host);
475 		}
476 	} else {
477 		/* If we run on an NFS server, delete all locks held by the client */
478 		if ((host = nlm_lookup_host(1, &saddr, prot, vers)) != NULL) {
479 			nlmsvc_free_host_resources(host);
480 			nlm_release_host(host);
481 		}
482 	}
483 
484 	return rpc_success;
485 }
486 
487 /*
488  * client sent a GRANTED_RES, let's remove the associated block
489  */
490 static int
491 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
492                                                 void            *resp)
493 {
494 	if (!nlmsvc_ops)
495 		return rpc_success;
496 
497 	dprintk("lockd: GRANTED_RES   called\n");
498 
499 	nlmsvc_grant_reply(rqstp, &argp->cookie, argp->status);
500 	return rpc_success;
501 }
502 
503 /*
504  * NLM Server procedures.
505  */
506 
507 #define nlmsvc_encode_norep	nlmsvc_encode_void
508 #define nlmsvc_decode_norep	nlmsvc_decode_void
509 #define nlmsvc_decode_testres	nlmsvc_decode_void
510 #define nlmsvc_decode_lockres	nlmsvc_decode_void
511 #define nlmsvc_decode_unlockres	nlmsvc_decode_void
512 #define nlmsvc_decode_cancelres	nlmsvc_decode_void
513 #define nlmsvc_decode_grantedres	nlmsvc_decode_void
514 
515 #define nlmsvc_proc_none	nlmsvc_proc_null
516 #define nlmsvc_proc_test_res	nlmsvc_proc_null
517 #define nlmsvc_proc_lock_res	nlmsvc_proc_null
518 #define nlmsvc_proc_cancel_res	nlmsvc_proc_null
519 #define nlmsvc_proc_unlock_res	nlmsvc_proc_null
520 
521 struct nlm_void			{ int dummy; };
522 
523 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
524  { .pc_func	= (svc_procfunc) nlmsvc_proc_##name,	\
525    .pc_decode	= (kxdrproc_t) nlmsvc_decode_##xargt,	\
526    .pc_encode	= (kxdrproc_t) nlmsvc_encode_##xrest,	\
527    .pc_release	= NULL,					\
528    .pc_argsize	= sizeof(struct nlm_##argt),		\
529    .pc_ressize	= sizeof(struct nlm_##rest),		\
530    .pc_xdrressize = respsize,				\
531  }
532 
533 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
534 #define	St	1				/* status */
535 #define	No	(1+1024/4)			/* Net Obj */
536 #define	Rg	2				/* range - offset + size */
537 
538 struct svc_procedure		nlmsvc_procedures[] = {
539   PROC(null,		void,		void,		void,	void, 1),
540   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
541   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
542   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
543   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
544   PROC(granted,		testargs,	res,		args,	res, Ck+St),
545   PROC(test_msg,	testargs,	norep,		args,	void, 1),
546   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
547   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
548   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
549   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
550   PROC(test_res,	testres,	norep,		res,	void, 1),
551   PROC(lock_res,	lockres,	norep,		res,	void, 1),
552   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
553   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
554   PROC(granted_res,	res,		norep,		res,	void, 1),
555   /* statd callback */
556   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
557   PROC(none,		void,		void,		void,	void, 1),
558   PROC(none,		void,		void,		void,	void, 1),
559   PROC(none,		void,		void,		void,	void, 1),
560   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
561   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
562   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
563   PROC(free_all,	notify,		void,		args,	void, 0),
564 
565 };
566