xref: /openbmc/linux/fs/lockd/svcproc.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
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 static u32	nlmsvc_callback(struct svc_rqst *, u32, struct nlm_res *);
26 static void	nlmsvc_callback_exit(struct rpc_task *);
27 
28 #ifdef CONFIG_LOCKD_V4
29 static u32
30 cast_to_nlm(u32 status, u32 vers)
31 {
32 	/* Note: status is assumed to be in network byte order !!! */
33 	if (vers != 4){
34 		switch (status) {
35 		case nlm_granted:
36 		case nlm_lck_denied:
37 		case nlm_lck_denied_nolocks:
38 		case nlm_lck_blocked:
39 		case nlm_lck_denied_grace_period:
40 			break;
41 		case nlm4_deadlock:
42 			status = nlm_lck_denied;
43 			break;
44 		default:
45 			status = nlm_lck_denied_nolocks;
46 		}
47 	}
48 
49 	return (status);
50 }
51 #define	cast_status(status) (cast_to_nlm(status, rqstp->rq_vers))
52 #else
53 #define cast_status(status) (status)
54 #endif
55 
56 /*
57  * Obtain client and file from arguments
58  */
59 static u32
60 nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
61 			struct nlm_host **hostp, struct nlm_file **filp)
62 {
63 	struct nlm_host		*host = NULL;
64 	struct nlm_file		*file = NULL;
65 	struct nlm_lock		*lock = &argp->lock;
66 	u32			error;
67 
68 	/* nfsd callbacks must have been installed for this procedure */
69 	if (!nlmsvc_ops)
70 		return nlm_lck_denied_nolocks;
71 
72 	/* Obtain host handle */
73 	if (!(host = nlmsvc_lookup_host(rqstp))
74 	 || (argp->monitor && !host->h_monitored && nsm_monitor(host) < 0))
75 		goto no_locks;
76 	*hostp = host;
77 
78 	/* Obtain file pointer. Not used by FREE_ALL call. */
79 	if (filp != NULL) {
80 		if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
81 			goto no_locks;
82 		*filp = file;
83 
84 		/* Set up the missing parts of the file_lock structure */
85 		lock->fl.fl_file  = file->f_file;
86 		lock->fl.fl_owner = (fl_owner_t) host;
87 		lock->fl.fl_lmops = &nlmsvc_lock_operations;
88 	}
89 
90 	return 0;
91 
92 no_locks:
93 	if (host)
94 		nlm_release_host(host);
95 	return nlm_lck_denied_nolocks;
96 }
97 
98 /*
99  * NULL: Test for presence of service
100  */
101 static int
102 nlmsvc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
103 {
104 	dprintk("lockd: NULL          called\n");
105 	return rpc_success;
106 }
107 
108 /*
109  * TEST: Check for conflicting lock
110  */
111 static int
112 nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
113 				         struct nlm_res  *resp)
114 {
115 	struct nlm_host	*host;
116 	struct nlm_file	*file;
117 
118 	dprintk("lockd: TEST          called\n");
119 	resp->cookie = argp->cookie;
120 
121 	/* Don't accept test requests during grace period */
122 	if (nlmsvc_grace_period) {
123 		resp->status = nlm_lck_denied_grace_period;
124 		return rpc_success;
125 	}
126 
127 	/* Obtain client and file */
128 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
129 		return rpc_success;
130 
131 	/* Now check for conflicting locks */
132 	resp->status = cast_status(nlmsvc_testlock(file, &argp->lock, &resp->lock));
133 
134 	dprintk("lockd: TEST          status %d vers %d\n",
135 		ntohl(resp->status), rqstp->rq_vers);
136 	nlm_release_host(host);
137 	nlm_release_file(file);
138 	return rpc_success;
139 }
140 
141 static int
142 nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
143 				         struct nlm_res  *resp)
144 {
145 	struct nlm_host	*host;
146 	struct nlm_file	*file;
147 
148 	dprintk("lockd: LOCK          called\n");
149 
150 	resp->cookie = argp->cookie;
151 
152 	/* Don't accept new lock requests during grace period */
153 	if (nlmsvc_grace_period && !argp->reclaim) {
154 		resp->status = nlm_lck_denied_grace_period;
155 		return rpc_success;
156 	}
157 
158 	/* Obtain client and file */
159 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
160 		return rpc_success;
161 
162 #if 0
163 	/* If supplied state doesn't match current state, we assume it's
164 	 * an old request that time-warped somehow. Any error return would
165 	 * do in this case because it's irrelevant anyway.
166 	 *
167 	 * NB: We don't retrieve the remote host's state yet.
168 	 */
169 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
170 		resp->status = nlm_lck_denied_nolocks;
171 	} else
172 #endif
173 
174 	/* Now try to lock the file */
175 	resp->status = cast_status(nlmsvc_lock(rqstp, file, &argp->lock,
176 					       argp->block, &argp->cookie));
177 
178 	dprintk("lockd: LOCK          status %d\n", ntohl(resp->status));
179 	nlm_release_host(host);
180 	nlm_release_file(file);
181 	return rpc_success;
182 }
183 
184 static int
185 nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
186 				           struct nlm_res  *resp)
187 {
188 	struct nlm_host	*host;
189 	struct nlm_file	*file;
190 
191 	dprintk("lockd: CANCEL        called\n");
192 
193 	resp->cookie = argp->cookie;
194 
195 	/* Don't accept requests during grace period */
196 	if (nlmsvc_grace_period) {
197 		resp->status = nlm_lck_denied_grace_period;
198 		return rpc_success;
199 	}
200 
201 	/* Obtain client and file */
202 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
203 		return rpc_success;
204 
205 	/* Try to cancel request. */
206 	resp->status = cast_status(nlmsvc_cancel_blocked(file, &argp->lock));
207 
208 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
209 	nlm_release_host(host);
210 	nlm_release_file(file);
211 	return rpc_success;
212 }
213 
214 /*
215  * UNLOCK: release a lock
216  */
217 static int
218 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
219 				           struct nlm_res  *resp)
220 {
221 	struct nlm_host	*host;
222 	struct nlm_file	*file;
223 
224 	dprintk("lockd: UNLOCK        called\n");
225 
226 	resp->cookie = argp->cookie;
227 
228 	/* Don't accept new lock requests during grace period */
229 	if (nlmsvc_grace_period) {
230 		resp->status = nlm_lck_denied_grace_period;
231 		return rpc_success;
232 	}
233 
234 	/* Obtain client and file */
235 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
236 		return rpc_success;
237 
238 	/* Now try to remove the lock */
239 	resp->status = cast_status(nlmsvc_unlock(file, &argp->lock));
240 
241 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
242 	nlm_release_host(host);
243 	nlm_release_file(file);
244 	return rpc_success;
245 }
246 
247 /*
248  * GRANTED: A server calls us to tell that a process' lock request
249  * was granted
250  */
251 static int
252 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
253 				            struct nlm_res  *resp)
254 {
255 	resp->cookie = argp->cookie;
256 
257 	dprintk("lockd: GRANTED       called\n");
258 	resp->status = nlmclnt_grant(&argp->lock);
259 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
260 	return rpc_success;
261 }
262 
263 /*
264  * `Async' versions of the above service routines. They aren't really,
265  * because we send the callback before the reply proper. I hope this
266  * doesn't break any clients.
267  */
268 static int
269 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
270 					     void	     *resp)
271 {
272 	struct nlm_res	res;
273 	u32		stat;
274 
275 	dprintk("lockd: TEST_MSG      called\n");
276 	memset(&res, 0, sizeof(res));
277 
278 	if ((stat = nlmsvc_proc_test(rqstp, argp, &res)) == 0)
279 		stat = nlmsvc_callback(rqstp, NLMPROC_TEST_RES, &res);
280 	return stat;
281 }
282 
283 static int
284 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
285 					     void	     *resp)
286 {
287 	struct nlm_res	res;
288 	u32		stat;
289 
290 	dprintk("lockd: LOCK_MSG      called\n");
291 	memset(&res, 0, sizeof(res));
292 
293 	if ((stat = nlmsvc_proc_lock(rqstp, argp, &res)) == 0)
294 		stat = nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, &res);
295 	return stat;
296 }
297 
298 static int
299 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
300 					       void	       *resp)
301 {
302 	struct nlm_res	res;
303 	u32		stat;
304 
305 	dprintk("lockd: CANCEL_MSG    called\n");
306 	memset(&res, 0, sizeof(res));
307 
308 	if ((stat = nlmsvc_proc_cancel(rqstp, argp, &res)) == 0)
309 		stat = nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, &res);
310 	return stat;
311 }
312 
313 static int
314 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
315                                                void            *resp)
316 {
317 	struct nlm_res	res;
318 	u32		stat;
319 
320 	dprintk("lockd: UNLOCK_MSG    called\n");
321 	memset(&res, 0, sizeof(res));
322 
323 	if ((stat = nlmsvc_proc_unlock(rqstp, argp, &res)) == 0)
324 		stat = nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, &res);
325 	return stat;
326 }
327 
328 static int
329 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
330                                                 void            *resp)
331 {
332 	struct nlm_res	res;
333 	u32		stat;
334 
335 	dprintk("lockd: GRANTED_MSG   called\n");
336 	memset(&res, 0, sizeof(res));
337 
338 	if ((stat = nlmsvc_proc_granted(rqstp, argp, &res)) == 0)
339 		stat = nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, &res);
340 	return stat;
341 }
342 
343 /*
344  * SHARE: create a DOS share or alter existing share.
345  */
346 static int
347 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
348 				          struct nlm_res  *resp)
349 {
350 	struct nlm_host	*host;
351 	struct nlm_file	*file;
352 
353 	dprintk("lockd: SHARE         called\n");
354 
355 	resp->cookie = argp->cookie;
356 
357 	/* Don't accept new lock requests during grace period */
358 	if (nlmsvc_grace_period && !argp->reclaim) {
359 		resp->status = nlm_lck_denied_grace_period;
360 		return rpc_success;
361 	}
362 
363 	/* Obtain client and file */
364 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
365 		return rpc_success;
366 
367 	/* Now try to create the share */
368 	resp->status = cast_status(nlmsvc_share_file(host, file, argp));
369 
370 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
371 	nlm_release_host(host);
372 	nlm_release_file(file);
373 	return rpc_success;
374 }
375 
376 /*
377  * UNSHARE: Release a DOS share.
378  */
379 static int
380 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
381 				            struct nlm_res  *resp)
382 {
383 	struct nlm_host	*host;
384 	struct nlm_file	*file;
385 
386 	dprintk("lockd: UNSHARE       called\n");
387 
388 	resp->cookie = argp->cookie;
389 
390 	/* Don't accept requests during grace period */
391 	if (nlmsvc_grace_period) {
392 		resp->status = nlm_lck_denied_grace_period;
393 		return rpc_success;
394 	}
395 
396 	/* Obtain client and file */
397 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
398 		return rpc_success;
399 
400 	/* Now try to unshare the file */
401 	resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
402 
403 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
404 	nlm_release_host(host);
405 	nlm_release_file(file);
406 	return rpc_success;
407 }
408 
409 /*
410  * NM_LOCK: Create an unmonitored lock
411  */
412 static int
413 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
414 				            struct nlm_res  *resp)
415 {
416 	dprintk("lockd: NM_LOCK       called\n");
417 
418 	argp->monitor = 0;		/* just clean the monitor flag */
419 	return nlmsvc_proc_lock(rqstp, argp, resp);
420 }
421 
422 /*
423  * FREE_ALL: Release all locks and shares held by client
424  */
425 static int
426 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
427 					     void            *resp)
428 {
429 	struct nlm_host	*host;
430 
431 	/* Obtain client */
432 	if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
433 		return rpc_success;
434 
435 	nlmsvc_free_host_resources(host);
436 	nlm_release_host(host);
437 	return rpc_success;
438 }
439 
440 /*
441  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
442  */
443 static int
444 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
445 					      void	        *resp)
446 {
447 	struct sockaddr_in	saddr = rqstp->rq_addr;
448 	int			vers = argp->vers;
449 	int			prot = argp->proto >> 1;
450 	struct nlm_host		*host;
451 
452 	dprintk("lockd: SM_NOTIFY     called\n");
453 	if (saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)
454 	 || ntohs(saddr.sin_port) >= 1024) {
455 		printk(KERN_WARNING
456 			"lockd: rejected NSM callback from %08x:%d\n",
457 			ntohl(rqstp->rq_addr.sin_addr.s_addr),
458 			ntohs(rqstp->rq_addr.sin_port));
459 		return rpc_system_err;
460 	}
461 
462 	/* Obtain the host pointer for this NFS server and try to
463 	 * reclaim all locks we hold on this server.
464 	 */
465 	saddr.sin_addr.s_addr = argp->addr;
466 	if ((argp->proto & 1)==0) {
467 		if ((host = nlmclnt_lookup_host(&saddr, prot, vers)) != NULL) {
468 			nlmclnt_recovery(host, argp->state);
469 			nlm_release_host(host);
470 		}
471 	} else {
472 		/* If we run on an NFS server, delete all locks held by the client */
473 		if ((host = nlm_lookup_host(1, &saddr, prot, vers)) != NULL) {
474 			nlmsvc_free_host_resources(host);
475 			nlm_release_host(host);
476 		}
477 	}
478 
479 	return rpc_success;
480 }
481 
482 /*
483  * client sent a GRANTED_RES, let's remove the associated block
484  */
485 static int
486 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
487                                                 void            *resp)
488 {
489 	if (!nlmsvc_ops)
490 		return rpc_success;
491 
492 	dprintk("lockd: GRANTED_RES   called\n");
493 
494 	nlmsvc_grant_reply(rqstp, &argp->cookie, argp->status);
495 	return rpc_success;
496 }
497 
498 /*
499  * This is the generic lockd callback for async RPC calls
500  */
501 static u32
502 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_res *resp)
503 {
504 	struct nlm_host	*host;
505 	struct nlm_rqst	*call;
506 
507 	if (!(call = nlmclnt_alloc_call()))
508 		return rpc_system_err;
509 
510 	host = nlmclnt_lookup_host(&rqstp->rq_addr,
511 				rqstp->rq_prot, rqstp->rq_vers);
512 	if (!host) {
513 		kfree(call);
514 		return rpc_system_err;
515 	}
516 
517 	call->a_flags = RPC_TASK_ASYNC;
518 	call->a_host  = host;
519 	memcpy(&call->a_args, resp, sizeof(*resp));
520 
521 	if (nlmsvc_async_call(call, proc, nlmsvc_callback_exit) < 0)
522 		goto error;
523 
524 	return rpc_success;
525  error:
526 	nlm_release_host(host);
527 	kfree(call);
528 	return rpc_system_err;
529 }
530 
531 static void
532 nlmsvc_callback_exit(struct rpc_task *task)
533 {
534 	struct nlm_rqst	*call = (struct nlm_rqst *) task->tk_calldata;
535 
536 	if (task->tk_status < 0) {
537 		dprintk("lockd: %4d callback failed (errno = %d)\n",
538 					task->tk_pid, -task->tk_status);
539 	}
540 	nlm_release_host(call->a_host);
541 	kfree(call);
542 }
543 
544 /*
545  * NLM Server procedures.
546  */
547 
548 #define nlmsvc_encode_norep	nlmsvc_encode_void
549 #define nlmsvc_decode_norep	nlmsvc_decode_void
550 #define nlmsvc_decode_testres	nlmsvc_decode_void
551 #define nlmsvc_decode_lockres	nlmsvc_decode_void
552 #define nlmsvc_decode_unlockres	nlmsvc_decode_void
553 #define nlmsvc_decode_cancelres	nlmsvc_decode_void
554 #define nlmsvc_decode_grantedres	nlmsvc_decode_void
555 
556 #define nlmsvc_proc_none	nlmsvc_proc_null
557 #define nlmsvc_proc_test_res	nlmsvc_proc_null
558 #define nlmsvc_proc_lock_res	nlmsvc_proc_null
559 #define nlmsvc_proc_cancel_res	nlmsvc_proc_null
560 #define nlmsvc_proc_unlock_res	nlmsvc_proc_null
561 
562 struct nlm_void			{ int dummy; };
563 
564 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
565  { .pc_func	= (svc_procfunc) nlmsvc_proc_##name,	\
566    .pc_decode	= (kxdrproc_t) nlmsvc_decode_##xargt,	\
567    .pc_encode	= (kxdrproc_t) nlmsvc_encode_##xrest,	\
568    .pc_release	= NULL,					\
569    .pc_argsize	= sizeof(struct nlm_##argt),		\
570    .pc_ressize	= sizeof(struct nlm_##rest),		\
571    .pc_xdrressize = respsize,				\
572  }
573 
574 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
575 #define	St	1				/* status */
576 #define	No	(1+1024/4)			/* Net Obj */
577 #define	Rg	2				/* range - offset + size */
578 
579 struct svc_procedure		nlmsvc_procedures[] = {
580   PROC(null,		void,		void,		void,	void, 1),
581   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
582   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
583   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
584   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
585   PROC(granted,		testargs,	res,		args,	res, Ck+St),
586   PROC(test_msg,	testargs,	norep,		args,	void, 1),
587   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
588   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
589   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
590   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
591   PROC(test_res,	testres,	norep,		res,	void, 1),
592   PROC(lock_res,	lockres,	norep,		res,	void, 1),
593   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
594   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
595   PROC(granted_res,	res,		norep,		res,	void, 1),
596   /* statd callback */
597   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
598   PROC(none,		void,		void,		void,	void, 1),
599   PROC(none,		void,		void,		void,	void, 1),
600   PROC(none,		void,		void,		void,	void, 1),
601   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
602   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
603   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
604   PROC(free_all,	notify,		void,		args,	void, 0),
605 
606 };
607