xref: /linux/fs/lockd/svcproc.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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 			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 	if (host)
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 
116 	dprintk("lockd: TEST          called\n");
117 	resp->cookie = argp->cookie;
118 
119 	/* Don't accept test requests during grace period */
120 	if (nlmsvc_grace_period) {
121 		resp->status = nlm_lck_denied_grace_period;
122 		return rpc_success;
123 	}
124 
125 	/* Obtain client and file */
126 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
127 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
128 
129 	/* Now check for conflicting locks */
130 	resp->status = cast_status(nlmsvc_testlock(file, &argp->lock, &resp->lock));
131 
132 	dprintk("lockd: TEST          status %d vers %d\n",
133 		ntohl(resp->status), rqstp->rq_vers);
134 	nlm_release_host(host);
135 	nlm_release_file(file);
136 	return rpc_success;
137 }
138 
139 static __be32
140 nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
141 				         struct nlm_res  *resp)
142 {
143 	struct nlm_host	*host;
144 	struct nlm_file	*file;
145 
146 	dprintk("lockd: LOCK          called\n");
147 
148 	resp->cookie = argp->cookie;
149 
150 	/* Don't accept new lock requests during grace period */
151 	if (nlmsvc_grace_period && !argp->reclaim) {
152 		resp->status = nlm_lck_denied_grace_period;
153 		return rpc_success;
154 	}
155 
156 	/* Obtain client and file */
157 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
158 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
159 
160 #if 0
161 	/* If supplied state doesn't match current state, we assume it's
162 	 * an old request that time-warped somehow. Any error return would
163 	 * do in this case because it's irrelevant anyway.
164 	 *
165 	 * NB: We don't retrieve the remote host's state yet.
166 	 */
167 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
168 		resp->status = nlm_lck_denied_nolocks;
169 	} else
170 #endif
171 
172 	/* Now try to lock the file */
173 	resp->status = cast_status(nlmsvc_lock(rqstp, file, &argp->lock,
174 					       argp->block, &argp->cookie));
175 
176 	dprintk("lockd: LOCK          status %d\n", ntohl(resp->status));
177 	nlm_release_host(host);
178 	nlm_release_file(file);
179 	return rpc_success;
180 }
181 
182 static __be32
183 nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
184 				           struct nlm_res  *resp)
185 {
186 	struct nlm_host	*host;
187 	struct nlm_file	*file;
188 
189 	dprintk("lockd: CANCEL        called\n");
190 
191 	resp->cookie = argp->cookie;
192 
193 	/* Don't accept requests during grace period */
194 	if (nlmsvc_grace_period) {
195 		resp->status = nlm_lck_denied_grace_period;
196 		return rpc_success;
197 	}
198 
199 	/* Obtain client and file */
200 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
201 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
202 
203 	/* Try to cancel request. */
204 	resp->status = cast_status(nlmsvc_cancel_blocked(file, &argp->lock));
205 
206 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
207 	nlm_release_host(host);
208 	nlm_release_file(file);
209 	return rpc_success;
210 }
211 
212 /*
213  * UNLOCK: release a lock
214  */
215 static __be32
216 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
217 				           struct nlm_res  *resp)
218 {
219 	struct nlm_host	*host;
220 	struct nlm_file	*file;
221 
222 	dprintk("lockd: UNLOCK        called\n");
223 
224 	resp->cookie = argp->cookie;
225 
226 	/* Don't accept new lock requests during grace period */
227 	if (nlmsvc_grace_period) {
228 		resp->status = nlm_lck_denied_grace_period;
229 		return rpc_success;
230 	}
231 
232 	/* Obtain client and file */
233 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
234 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
235 
236 	/* Now try to remove the lock */
237 	resp->status = cast_status(nlmsvc_unlock(file, &argp->lock));
238 
239 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
240 	nlm_release_host(host);
241 	nlm_release_file(file);
242 	return rpc_success;
243 }
244 
245 /*
246  * GRANTED: A server calls us to tell that a process' lock request
247  * was granted
248  */
249 static __be32
250 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
251 				            struct nlm_res  *resp)
252 {
253 	resp->cookie = argp->cookie;
254 
255 	dprintk("lockd: GRANTED       called\n");
256 	resp->status = nlmclnt_grant(svc_addr_in(rqstp), &argp->lock);
257 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
258 	return rpc_success;
259 }
260 
261 /*
262  * This is the generic lockd callback for async RPC calls
263  */
264 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
265 {
266 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
267 			-task->tk_status);
268 }
269 
270 static void nlmsvc_callback_release(void *data)
271 {
272 	nlm_release_call(data);
273 }
274 
275 static const struct rpc_call_ops nlmsvc_callback_ops = {
276 	.rpc_call_done = nlmsvc_callback_exit,
277 	.rpc_release = nlmsvc_callback_release,
278 };
279 
280 /*
281  * `Async' versions of the above service routines. They aren't really,
282  * because we send the callback before the reply proper. I hope this
283  * doesn't break any clients.
284  */
285 static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
286 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
287 {
288 	struct nlm_host	*host;
289 	struct nlm_rqst	*call;
290 	__be32 stat;
291 
292 	host = nlmsvc_lookup_host(rqstp,
293 				  argp->lock.caller,
294 				  argp->lock.len);
295 	if (host == NULL)
296 		return rpc_system_err;
297 
298 	call = nlm_alloc_call(host);
299 	if (call == NULL)
300 		return rpc_system_err;
301 
302 	stat = func(rqstp, argp, &call->a_res);
303 	if (stat != 0) {
304 		nlm_release_call(call);
305 		return stat;
306 	}
307 
308 	call->a_flags = RPC_TASK_ASYNC;
309 	if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
310 		return rpc_system_err;
311 	return rpc_success;
312 }
313 
314 static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
315 					     void	     *resp)
316 {
317 	dprintk("lockd: TEST_MSG      called\n");
318 	return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
319 }
320 
321 static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
322 					     void	     *resp)
323 {
324 	dprintk("lockd: LOCK_MSG      called\n");
325 	return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
326 }
327 
328 static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
329 					       void	       *resp)
330 {
331 	dprintk("lockd: CANCEL_MSG    called\n");
332 	return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
333 }
334 
335 static __be32
336 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
337                                                void            *resp)
338 {
339 	dprintk("lockd: UNLOCK_MSG    called\n");
340 	return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
341 }
342 
343 static __be32
344 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
345                                                 void            *resp)
346 {
347 	dprintk("lockd: GRANTED_MSG   called\n");
348 	return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
349 }
350 
351 /*
352  * SHARE: create a DOS share or alter existing share.
353  */
354 static __be32
355 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
356 				          struct nlm_res  *resp)
357 {
358 	struct nlm_host	*host;
359 	struct nlm_file	*file;
360 
361 	dprintk("lockd: SHARE         called\n");
362 
363 	resp->cookie = argp->cookie;
364 
365 	/* Don't accept new lock requests during grace period */
366 	if (nlmsvc_grace_period && !argp->reclaim) {
367 		resp->status = nlm_lck_denied_grace_period;
368 		return rpc_success;
369 	}
370 
371 	/* Obtain client and file */
372 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
373 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
374 
375 	/* Now try to create the share */
376 	resp->status = cast_status(nlmsvc_share_file(host, file, argp));
377 
378 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
379 	nlm_release_host(host);
380 	nlm_release_file(file);
381 	return rpc_success;
382 }
383 
384 /*
385  * UNSHARE: Release a DOS share.
386  */
387 static __be32
388 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
389 				            struct nlm_res  *resp)
390 {
391 	struct nlm_host	*host;
392 	struct nlm_file	*file;
393 
394 	dprintk("lockd: UNSHARE       called\n");
395 
396 	resp->cookie = argp->cookie;
397 
398 	/* Don't accept requests during grace period */
399 	if (nlmsvc_grace_period) {
400 		resp->status = nlm_lck_denied_grace_period;
401 		return rpc_success;
402 	}
403 
404 	/* Obtain client and file */
405 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
406 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
407 
408 	/* Now try to unshare the file */
409 	resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
410 
411 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
412 	nlm_release_host(host);
413 	nlm_release_file(file);
414 	return rpc_success;
415 }
416 
417 /*
418  * NM_LOCK: Create an unmonitored lock
419  */
420 static __be32
421 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
422 				            struct nlm_res  *resp)
423 {
424 	dprintk("lockd: NM_LOCK       called\n");
425 
426 	argp->monitor = 0;		/* just clean the monitor flag */
427 	return nlmsvc_proc_lock(rqstp, argp, resp);
428 }
429 
430 /*
431  * FREE_ALL: Release all locks and shares held by client
432  */
433 static __be32
434 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
435 					     void            *resp)
436 {
437 	struct nlm_host	*host;
438 
439 	/* Obtain client */
440 	if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
441 		return rpc_success;
442 
443 	nlmsvc_free_host_resources(host);
444 	nlm_release_host(host);
445 	return rpc_success;
446 }
447 
448 /*
449  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
450  */
451 static __be32
452 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
453 					      void	        *resp)
454 {
455 	struct sockaddr_in	saddr;
456 
457 	memcpy(&saddr, svc_addr_in(rqstp), sizeof(saddr));
458 
459 	dprintk("lockd: SM_NOTIFY     called\n");
460 	if (saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)
461 	 || ntohs(saddr.sin_port) >= 1024) {
462 		char buf[RPC_MAX_ADDRBUFLEN];
463 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
464 				svc_print_addr(rqstp, buf, sizeof(buf)));
465 		return rpc_system_err;
466 	}
467 
468 	/* Obtain the host pointer for this NFS server and try to
469 	 * reclaim all locks we hold on this server.
470 	 */
471 	memset(&saddr, 0, sizeof(saddr));
472 	saddr.sin_addr.s_addr = argp->addr;
473 	nlm_host_rebooted(&saddr, argp->mon, argp->len, argp->state);
474 
475 	return rpc_success;
476 }
477 
478 /*
479  * client sent a GRANTED_RES, let's remove the associated block
480  */
481 static __be32
482 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
483                                                 void            *resp)
484 {
485 	if (!nlmsvc_ops)
486 		return rpc_success;
487 
488 	dprintk("lockd: GRANTED_RES   called\n");
489 
490 	nlmsvc_grant_reply(&argp->cookie, argp->status);
491 	return rpc_success;
492 }
493 
494 /*
495  * NLM Server procedures.
496  */
497 
498 #define nlmsvc_encode_norep	nlmsvc_encode_void
499 #define nlmsvc_decode_norep	nlmsvc_decode_void
500 #define nlmsvc_decode_testres	nlmsvc_decode_void
501 #define nlmsvc_decode_lockres	nlmsvc_decode_void
502 #define nlmsvc_decode_unlockres	nlmsvc_decode_void
503 #define nlmsvc_decode_cancelres	nlmsvc_decode_void
504 #define nlmsvc_decode_grantedres	nlmsvc_decode_void
505 
506 #define nlmsvc_proc_none	nlmsvc_proc_null
507 #define nlmsvc_proc_test_res	nlmsvc_proc_null
508 #define nlmsvc_proc_lock_res	nlmsvc_proc_null
509 #define nlmsvc_proc_cancel_res	nlmsvc_proc_null
510 #define nlmsvc_proc_unlock_res	nlmsvc_proc_null
511 
512 struct nlm_void			{ int dummy; };
513 
514 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
515  { .pc_func	= (svc_procfunc) nlmsvc_proc_##name,	\
516    .pc_decode	= (kxdrproc_t) nlmsvc_decode_##xargt,	\
517    .pc_encode	= (kxdrproc_t) nlmsvc_encode_##xrest,	\
518    .pc_release	= NULL,					\
519    .pc_argsize	= sizeof(struct nlm_##argt),		\
520    .pc_ressize	= sizeof(struct nlm_##rest),		\
521    .pc_xdrressize = respsize,				\
522  }
523 
524 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
525 #define	St	1				/* status */
526 #define	No	(1+1024/4)			/* Net Obj */
527 #define	Rg	2				/* range - offset + size */
528 
529 struct svc_procedure		nlmsvc_procedures[] = {
530   PROC(null,		void,		void,		void,	void, 1),
531   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
532   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
533   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
534   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
535   PROC(granted,		testargs,	res,		args,	res, Ck+St),
536   PROC(test_msg,	testargs,	norep,		args,	void, 1),
537   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
538   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
539   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
540   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
541   PROC(test_res,	testres,	norep,		res,	void, 1),
542   PROC(lock_res,	lockres,	norep,		res,	void, 1),
543   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
544   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
545   PROC(granted_res,	res,		norep,		res,	void, 1),
546   /* statd callback */
547   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
548   PROC(none,		void,		void,		void,	void, 1),
549   PROC(none,		void,		void,		void,	void, 1),
550   PROC(none,		void,		void,		void,	void, 1),
551   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
552   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
553   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
554   PROC(free_all,	notify,		void,		args,	void, 0),
555 
556 };
557