xref: /linux/fs/lockd/svcproc.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
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 u32
26 cast_to_nlm(u32 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 			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 u32
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 	u32			error;
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))
70 	 || (argp->monitor && !host->h_monitored && 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 	if (host)
90 		nlm_release_host(host);
91 	return nlm_lck_denied_nolocks;
92 }
93 
94 /*
95  * NULL: Test for presence of service
96  */
97 static int
98 nlmsvc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
99 {
100 	dprintk("lockd: NULL          called\n");
101 	return rpc_success;
102 }
103 
104 /*
105  * TEST: Check for conflicting lock
106  */
107 static int
108 nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
109 				         struct nlm_res  *resp)
110 {
111 	struct nlm_host	*host;
112 	struct nlm_file	*file;
113 
114 	dprintk("lockd: TEST          called\n");
115 	resp->cookie = argp->cookie;
116 
117 	/* Don't accept test requests during grace period */
118 	if (nlmsvc_grace_period) {
119 		resp->status = nlm_lck_denied_grace_period;
120 		return rpc_success;
121 	}
122 
123 	/* Obtain client and file */
124 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
125 		return rpc_success;
126 
127 	/* Now check for conflicting locks */
128 	resp->status = cast_status(nlmsvc_testlock(file, &argp->lock, &resp->lock));
129 
130 	dprintk("lockd: TEST          status %d vers %d\n",
131 		ntohl(resp->status), rqstp->rq_vers);
132 	nlm_release_host(host);
133 	nlm_release_file(file);
134 	return rpc_success;
135 }
136 
137 static int
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 
144 	dprintk("lockd: LOCK          called\n");
145 
146 	resp->cookie = argp->cookie;
147 
148 	/* Don't accept new lock requests during grace period */
149 	if (nlmsvc_grace_period && !argp->reclaim) {
150 		resp->status = nlm_lck_denied_grace_period;
151 		return rpc_success;
152 	}
153 
154 	/* Obtain client and file */
155 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
156 		return rpc_success;
157 
158 #if 0
159 	/* If supplied state doesn't match current state, we assume it's
160 	 * an old request that time-warped somehow. Any error return would
161 	 * do in this case because it's irrelevant anyway.
162 	 *
163 	 * NB: We don't retrieve the remote host's state yet.
164 	 */
165 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
166 		resp->status = nlm_lck_denied_nolocks;
167 	} else
168 #endif
169 
170 	/* Now try to lock the file */
171 	resp->status = cast_status(nlmsvc_lock(rqstp, file, &argp->lock,
172 					       argp->block, &argp->cookie));
173 
174 	dprintk("lockd: LOCK          status %d\n", ntohl(resp->status));
175 	nlm_release_host(host);
176 	nlm_release_file(file);
177 	return rpc_success;
178 }
179 
180 static int
181 nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
182 				           struct nlm_res  *resp)
183 {
184 	struct nlm_host	*host;
185 	struct nlm_file	*file;
186 
187 	dprintk("lockd: CANCEL        called\n");
188 
189 	resp->cookie = argp->cookie;
190 
191 	/* Don't accept requests during grace period */
192 	if (nlmsvc_grace_period) {
193 		resp->status = nlm_lck_denied_grace_period;
194 		return rpc_success;
195 	}
196 
197 	/* Obtain client and file */
198 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
199 		return rpc_success;
200 
201 	/* Try to cancel request. */
202 	resp->status = cast_status(nlmsvc_cancel_blocked(file, &argp->lock));
203 
204 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
205 	nlm_release_host(host);
206 	nlm_release_file(file);
207 	return rpc_success;
208 }
209 
210 /*
211  * UNLOCK: release a lock
212  */
213 static int
214 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
215 				           struct nlm_res  *resp)
216 {
217 	struct nlm_host	*host;
218 	struct nlm_file	*file;
219 
220 	dprintk("lockd: UNLOCK        called\n");
221 
222 	resp->cookie = argp->cookie;
223 
224 	/* Don't accept new lock requests during grace period */
225 	if (nlmsvc_grace_period) {
226 		resp->status = nlm_lck_denied_grace_period;
227 		return rpc_success;
228 	}
229 
230 	/* Obtain client and file */
231 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
232 		return rpc_success;
233 
234 	/* Now try to remove the lock */
235 	resp->status = cast_status(nlmsvc_unlock(file, &argp->lock));
236 
237 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
238 	nlm_release_host(host);
239 	nlm_release_file(file);
240 	return rpc_success;
241 }
242 
243 /*
244  * GRANTED: A server calls us to tell that a process' lock request
245  * was granted
246  */
247 static int
248 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
249 				            struct nlm_res  *resp)
250 {
251 	resp->cookie = argp->cookie;
252 
253 	dprintk("lockd: GRANTED       called\n");
254 	resp->status = nlmclnt_grant(&rqstp->rq_addr, &argp->lock);
255 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
256 	return rpc_success;
257 }
258 
259 /*
260  * This is the generic lockd callback for async RPC calls
261  */
262 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
263 {
264 	dprintk("lockd: %4d callback returned %d\n", task->tk_pid,
265 			-task->tk_status);
266 }
267 
268 static void nlmsvc_callback_release(void *data)
269 {
270 	nlm_release_call(data);
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 int nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
284 		int (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
285 {
286 	struct nlm_host	*host;
287 	struct nlm_rqst	*call;
288 	int stat;
289 
290 	host = nlmsvc_lookup_host(rqstp);
291 	if (host == NULL)
292 		return rpc_system_err;
293 
294 	call = nlm_alloc_call(host);
295 	if (call == NULL)
296 		return rpc_system_err;
297 
298 	stat = func(rqstp, argp, &call->a_res);
299 	if (stat != 0) {
300 		nlm_release_call(call);
301 		return stat;
302 	}
303 
304 	call->a_flags = RPC_TASK_ASYNC;
305 	if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
306 		return rpc_system_err;
307 	return rpc_success;
308 }
309 
310 static int nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
311 					     void	     *resp)
312 {
313 	dprintk("lockd: TEST_MSG      called\n");
314 	return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
315 }
316 
317 static int nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
318 					     void	     *resp)
319 {
320 	dprintk("lockd: LOCK_MSG      called\n");
321 	return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
322 }
323 
324 static int nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
325 					       void	       *resp)
326 {
327 	dprintk("lockd: CANCEL_MSG    called\n");
328 	return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
329 }
330 
331 static int
332 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
333                                                void            *resp)
334 {
335 	dprintk("lockd: UNLOCK_MSG    called\n");
336 	return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
337 }
338 
339 static int
340 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
341                                                 void            *resp)
342 {
343 	dprintk("lockd: GRANTED_MSG   called\n");
344 	return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
345 }
346 
347 /*
348  * SHARE: create a DOS share or alter existing share.
349  */
350 static int
351 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
352 				          struct nlm_res  *resp)
353 {
354 	struct nlm_host	*host;
355 	struct nlm_file	*file;
356 
357 	dprintk("lockd: SHARE         called\n");
358 
359 	resp->cookie = argp->cookie;
360 
361 	/* Don't accept new lock requests during grace period */
362 	if (nlmsvc_grace_period && !argp->reclaim) {
363 		resp->status = nlm_lck_denied_grace_period;
364 		return rpc_success;
365 	}
366 
367 	/* Obtain client and file */
368 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
369 		return rpc_success;
370 
371 	/* Now try to create the share */
372 	resp->status = cast_status(nlmsvc_share_file(host, file, argp));
373 
374 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
375 	nlm_release_host(host);
376 	nlm_release_file(file);
377 	return rpc_success;
378 }
379 
380 /*
381  * UNSHARE: Release a DOS share.
382  */
383 static int
384 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
385 				            struct nlm_res  *resp)
386 {
387 	struct nlm_host	*host;
388 	struct nlm_file	*file;
389 
390 	dprintk("lockd: UNSHARE       called\n");
391 
392 	resp->cookie = argp->cookie;
393 
394 	/* Don't accept requests during grace period */
395 	if (nlmsvc_grace_period) {
396 		resp->status = nlm_lck_denied_grace_period;
397 		return rpc_success;
398 	}
399 
400 	/* Obtain client and file */
401 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
402 		return rpc_success;
403 
404 	/* Now try to unshare the file */
405 	resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
406 
407 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
408 	nlm_release_host(host);
409 	nlm_release_file(file);
410 	return rpc_success;
411 }
412 
413 /*
414  * NM_LOCK: Create an unmonitored lock
415  */
416 static int
417 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
418 				            struct nlm_res  *resp)
419 {
420 	dprintk("lockd: NM_LOCK       called\n");
421 
422 	argp->monitor = 0;		/* just clean the monitor flag */
423 	return nlmsvc_proc_lock(rqstp, argp, resp);
424 }
425 
426 /*
427  * FREE_ALL: Release all locks and shares held by client
428  */
429 static int
430 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
431 					     void            *resp)
432 {
433 	struct nlm_host	*host;
434 
435 	/* Obtain client */
436 	if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
437 		return rpc_success;
438 
439 	nlmsvc_free_host_resources(host);
440 	nlm_release_host(host);
441 	return rpc_success;
442 }
443 
444 /*
445  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
446  */
447 static int
448 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
449 					      void	        *resp)
450 {
451 	struct sockaddr_in	saddr = rqstp->rq_addr;
452 	int			vers = argp->vers;
453 	int			prot = argp->proto >> 1;
454 	struct nlm_host		*host;
455 
456 	dprintk("lockd: SM_NOTIFY     called\n");
457 	if (saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)
458 	 || ntohs(saddr.sin_port) >= 1024) {
459 		printk(KERN_WARNING
460 			"lockd: rejected NSM callback from %08x:%d\n",
461 			ntohl(rqstp->rq_addr.sin_addr.s_addr),
462 			ntohs(rqstp->rq_addr.sin_port));
463 		return rpc_system_err;
464 	}
465 
466 	/* Obtain the host pointer for this NFS server and try to
467 	 * reclaim all locks we hold on this server.
468 	 */
469 	saddr.sin_addr.s_addr = argp->addr;
470 	if ((argp->proto & 1)==0) {
471 		if ((host = nlmclnt_lookup_host(&saddr, prot, vers)) != NULL) {
472 			nlmclnt_recovery(host, argp->state);
473 			nlm_release_host(host);
474 		}
475 	} else {
476 		/* If we run on an NFS server, delete all locks held by the client */
477 		if ((host = nlm_lookup_host(1, &saddr, prot, vers)) != NULL) {
478 			nlmsvc_free_host_resources(host);
479 			nlm_release_host(host);
480 		}
481 	}
482 
483 	return rpc_success;
484 }
485 
486 /*
487  * client sent a GRANTED_RES, let's remove the associated block
488  */
489 static int
490 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
491                                                 void            *resp)
492 {
493 	if (!nlmsvc_ops)
494 		return rpc_success;
495 
496 	dprintk("lockd: GRANTED_RES   called\n");
497 
498 	nlmsvc_grant_reply(rqstp, &argp->cookie, argp->status);
499 	return rpc_success;
500 }
501 
502 /*
503  * NLM Server procedures.
504  */
505 
506 #define nlmsvc_encode_norep	nlmsvc_encode_void
507 #define nlmsvc_decode_norep	nlmsvc_decode_void
508 #define nlmsvc_decode_testres	nlmsvc_decode_void
509 #define nlmsvc_decode_lockres	nlmsvc_decode_void
510 #define nlmsvc_decode_unlockres	nlmsvc_decode_void
511 #define nlmsvc_decode_cancelres	nlmsvc_decode_void
512 #define nlmsvc_decode_grantedres	nlmsvc_decode_void
513 
514 #define nlmsvc_proc_none	nlmsvc_proc_null
515 #define nlmsvc_proc_test_res	nlmsvc_proc_null
516 #define nlmsvc_proc_lock_res	nlmsvc_proc_null
517 #define nlmsvc_proc_cancel_res	nlmsvc_proc_null
518 #define nlmsvc_proc_unlock_res	nlmsvc_proc_null
519 
520 struct nlm_void			{ int dummy; };
521 
522 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
523  { .pc_func	= (svc_procfunc) nlmsvc_proc_##name,	\
524    .pc_decode	= (kxdrproc_t) nlmsvc_decode_##xargt,	\
525    .pc_encode	= (kxdrproc_t) nlmsvc_encode_##xrest,	\
526    .pc_release	= NULL,					\
527    .pc_argsize	= sizeof(struct nlm_##argt),		\
528    .pc_ressize	= sizeof(struct nlm_##rest),		\
529    .pc_xdrressize = respsize,				\
530  }
531 
532 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
533 #define	St	1				/* status */
534 #define	No	(1+1024/4)			/* Net Obj */
535 #define	Rg	2				/* range - offset + size */
536 
537 struct svc_procedure		nlmsvc_procedures[] = {
538   PROC(null,		void,		void,		void,	void, 1),
539   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
540   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
541   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
542   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
543   PROC(granted,		testargs,	res,		args,	res, Ck+St),
544   PROC(test_msg,	testargs,	norep,		args,	void, 1),
545   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
546   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
547   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
548   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
549   PROC(test_res,	testres,	norep,		res,	void, 1),
550   PROC(lock_res,	lockres,	norep,		res,	void, 1),
551   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
552   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
553   PROC(granted_res,	res,		norep,		res,	void, 1),
554   /* statd callback */
555   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
556   PROC(none,		void,		void,		void,	void, 1),
557   PROC(none,		void,		void,		void,	void, 1),
558   PROC(none,		void,		void,		void,	void, 1),
559   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
560   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
561   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
562   PROC(free_all,	notify,		void,		args,	void, 0),
563 
564 };
565