xref: /openbmc/linux/fs/lockd/svcproc.c (revision 643d1f7f) 
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 	if (host)
91 		nlm_release_host(host);
92 	if (error)
93 		return error;
94 	return nlm_lck_denied_nolocks;
95 }
96 
97 /*
98  * NULL: Test for presence of service
99  */
100 static __be32
101 nlmsvc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
102 {
103 	dprintk("lockd: NULL          called\n");
104 	return rpc_success;
105 }
106 
107 /*
108  * TEST: Check for conflicting lock
109  */
110 static __be32
111 nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
112 				         struct nlm_res  *resp)
113 {
114 	struct nlm_host	*host;
115 	struct nlm_file	*file;
116 	int rc = rpc_success;
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 rc;
125 	}
126 
127 	/* Obtain client and file */
128 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
129 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
130 
131 	/* Now check for conflicting locks */
132 	resp->status = cast_status(nlmsvc_testlock(rqstp, file, &argp->lock, &resp->lock, &resp->cookie));
133 	if (resp->status == nlm_drop_reply)
134 		rc = rpc_drop_reply;
135 	else
136 		dprintk("lockd: TEST          status %d vers %d\n",
137 			ntohl(resp->status), rqstp->rq_vers);
138 
139 	nlm_release_host(host);
140 	nlm_release_file(file);
141 	return rc;
142 }
143 
144 static __be32
145 nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
146 				         struct nlm_res  *resp)
147 {
148 	struct nlm_host	*host;
149 	struct nlm_file	*file;
150 	int rc = rpc_success;
151 
152 	dprintk("lockd: LOCK          called\n");
153 
154 	resp->cookie = argp->cookie;
155 
156 	/* Don't accept new lock requests during grace period */
157 	if (nlmsvc_grace_period && !argp->reclaim) {
158 		resp->status = nlm_lck_denied_grace_period;
159 		return rc;
160 	}
161 
162 	/* Obtain client and file */
163 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
164 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
165 
166 #if 0
167 	/* If supplied state doesn't match current state, we assume it's
168 	 * an old request that time-warped somehow. Any error return would
169 	 * do in this case because it's irrelevant anyway.
170 	 *
171 	 * NB: We don't retrieve the remote host's state yet.
172 	 */
173 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
174 		resp->status = nlm_lck_denied_nolocks;
175 	} else
176 #endif
177 
178 	/* Now try to lock the file */
179 	resp->status = cast_status(nlmsvc_lock(rqstp, file, &argp->lock,
180 					       argp->block, &argp->cookie));
181 	if (resp->status == nlm_drop_reply)
182 		rc = rpc_drop_reply;
183 	else
184 		dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
185 
186 	nlm_release_host(host);
187 	nlm_release_file(file);
188 	return rc;
189 }
190 
191 static __be32
192 nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
193 				           struct nlm_res  *resp)
194 {
195 	struct nlm_host	*host;
196 	struct nlm_file	*file;
197 
198 	dprintk("lockd: CANCEL        called\n");
199 
200 	resp->cookie = argp->cookie;
201 
202 	/* Don't accept requests during grace period */
203 	if (nlmsvc_grace_period) {
204 		resp->status = nlm_lck_denied_grace_period;
205 		return rpc_success;
206 	}
207 
208 	/* Obtain client and file */
209 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
210 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
211 
212 	/* Try to cancel request. */
213 	resp->status = cast_status(nlmsvc_cancel_blocked(file, &argp->lock));
214 
215 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
216 	nlm_release_host(host);
217 	nlm_release_file(file);
218 	return rpc_success;
219 }
220 
221 /*
222  * UNLOCK: release a lock
223  */
224 static __be32
225 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
226 				           struct nlm_res  *resp)
227 {
228 	struct nlm_host	*host;
229 	struct nlm_file	*file;
230 
231 	dprintk("lockd: UNLOCK        called\n");
232 
233 	resp->cookie = argp->cookie;
234 
235 	/* Don't accept new lock requests during grace period */
236 	if (nlmsvc_grace_period) {
237 		resp->status = nlm_lck_denied_grace_period;
238 		return rpc_success;
239 	}
240 
241 	/* Obtain client and file */
242 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
243 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
244 
245 	/* Now try to remove the lock */
246 	resp->status = cast_status(nlmsvc_unlock(file, &argp->lock));
247 
248 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
249 	nlm_release_host(host);
250 	nlm_release_file(file);
251 	return rpc_success;
252 }
253 
254 /*
255  * GRANTED: A server calls us to tell that a process' lock request
256  * was granted
257  */
258 static __be32
259 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
260 				            struct nlm_res  *resp)
261 {
262 	resp->cookie = argp->cookie;
263 
264 	dprintk("lockd: GRANTED       called\n");
265 	resp->status = nlmclnt_grant(svc_addr_in(rqstp), &argp->lock);
266 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
267 	return rpc_success;
268 }
269 
270 /*
271  * This is the generic lockd callback for async RPC calls
272  */
273 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
274 {
275 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
276 			-task->tk_status);
277 }
278 
279 static void nlmsvc_callback_release(void *data)
280 {
281 	nlm_release_call(data);
282 }
283 
284 static const struct rpc_call_ops nlmsvc_callback_ops = {
285 	.rpc_call_done = nlmsvc_callback_exit,
286 	.rpc_release = nlmsvc_callback_release,
287 };
288 
289 /*
290  * `Async' versions of the above service routines. They aren't really,
291  * because we send the callback before the reply proper. I hope this
292  * doesn't break any clients.
293  */
294 static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
295 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
296 {
297 	struct nlm_host	*host;
298 	struct nlm_rqst	*call;
299 	__be32 stat;
300 
301 	host = nlmsvc_lookup_host(rqstp,
302 				  argp->lock.caller,
303 				  argp->lock.len);
304 	if (host == NULL)
305 		return rpc_system_err;
306 
307 	call = nlm_alloc_call(host);
308 	if (call == NULL)
309 		return rpc_system_err;
310 
311 	stat = func(rqstp, argp, &call->a_res);
312 	if (stat != 0) {
313 		nlm_release_call(call);
314 		return stat;
315 	}
316 
317 	call->a_flags = RPC_TASK_ASYNC;
318 	if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
319 		return rpc_system_err;
320 	return rpc_success;
321 }
322 
323 static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
324 					     void	     *resp)
325 {
326 	dprintk("lockd: TEST_MSG      called\n");
327 	return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
328 }
329 
330 static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
331 					     void	     *resp)
332 {
333 	dprintk("lockd: LOCK_MSG      called\n");
334 	return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
335 }
336 
337 static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
338 					       void	       *resp)
339 {
340 	dprintk("lockd: CANCEL_MSG    called\n");
341 	return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
342 }
343 
344 static __be32
345 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
346                                                void            *resp)
347 {
348 	dprintk("lockd: UNLOCK_MSG    called\n");
349 	return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
350 }
351 
352 static __be32
353 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
354                                                 void            *resp)
355 {
356 	dprintk("lockd: GRANTED_MSG   called\n");
357 	return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
358 }
359 
360 /*
361  * SHARE: create a DOS share or alter existing share.
362  */
363 static __be32
364 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
365 				          struct nlm_res  *resp)
366 {
367 	struct nlm_host	*host;
368 	struct nlm_file	*file;
369 
370 	dprintk("lockd: SHARE         called\n");
371 
372 	resp->cookie = argp->cookie;
373 
374 	/* Don't accept new lock requests during grace period */
375 	if (nlmsvc_grace_period && !argp->reclaim) {
376 		resp->status = nlm_lck_denied_grace_period;
377 		return rpc_success;
378 	}
379 
380 	/* Obtain client and file */
381 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
382 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
383 
384 	/* Now try to create the share */
385 	resp->status = cast_status(nlmsvc_share_file(host, file, argp));
386 
387 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
388 	nlm_release_host(host);
389 	nlm_release_file(file);
390 	return rpc_success;
391 }
392 
393 /*
394  * UNSHARE: Release a DOS share.
395  */
396 static __be32
397 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
398 				            struct nlm_res  *resp)
399 {
400 	struct nlm_host	*host;
401 	struct nlm_file	*file;
402 
403 	dprintk("lockd: UNSHARE       called\n");
404 
405 	resp->cookie = argp->cookie;
406 
407 	/* Don't accept requests during grace period */
408 	if (nlmsvc_grace_period) {
409 		resp->status = nlm_lck_denied_grace_period;
410 		return rpc_success;
411 	}
412 
413 	/* Obtain client and file */
414 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
415 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
416 
417 	/* Now try to unshare the file */
418 	resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
419 
420 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
421 	nlm_release_host(host);
422 	nlm_release_file(file);
423 	return rpc_success;
424 }
425 
426 /*
427  * NM_LOCK: Create an unmonitored lock
428  */
429 static __be32
430 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
431 				            struct nlm_res  *resp)
432 {
433 	dprintk("lockd: NM_LOCK       called\n");
434 
435 	argp->monitor = 0;		/* just clean the monitor flag */
436 	return nlmsvc_proc_lock(rqstp, argp, resp);
437 }
438 
439 /*
440  * FREE_ALL: Release all locks and shares held by client
441  */
442 static __be32
443 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
444 					     void            *resp)
445 {
446 	struct nlm_host	*host;
447 
448 	/* Obtain client */
449 	if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
450 		return rpc_success;
451 
452 	nlmsvc_free_host_resources(host);
453 	nlm_release_host(host);
454 	return rpc_success;
455 }
456 
457 /*
458  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
459  */
460 static __be32
461 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
462 					      void	        *resp)
463 {
464 	struct sockaddr_in	saddr;
465 
466 	memcpy(&saddr, svc_addr_in(rqstp), sizeof(saddr));
467 
468 	dprintk("lockd: SM_NOTIFY     called\n");
469 	if (saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)
470 	 || ntohs(saddr.sin_port) >= 1024) {
471 		char buf[RPC_MAX_ADDRBUFLEN];
472 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
473 				svc_print_addr(rqstp, buf, sizeof(buf)));
474 		return rpc_system_err;
475 	}
476 
477 	/* Obtain the host pointer for this NFS server and try to
478 	 * reclaim all locks we hold on this server.
479 	 */
480 	memset(&saddr, 0, sizeof(saddr));
481 	saddr.sin_addr.s_addr = argp->addr;
482 	nlm_host_rebooted(&saddr, argp->mon, argp->len, argp->state);
483 
484 	return rpc_success;
485 }
486 
487 /*
488  * client sent a GRANTED_RES, let's remove the associated block
489  */
490 static __be32
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(&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