xref: /openbmc/linux/fs/lockd/svcproc.c (revision 384740dc) 
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 	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 	__be32 rc = rpc_success;
116 
117 	dprintk("lockd: TEST          called\n");
118 	resp->cookie = argp->cookie;
119 
120 	/* Don't accept test requests during grace period */
121 	if (nlmsvc_grace_period) {
122 		resp->status = nlm_lck_denied_grace_period;
123 		return rc;
124 	}
125 
126 	/* Obtain client and file */
127 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
128 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
129 
130 	/* Now check for conflicting locks */
131 	resp->status = cast_status(nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie));
132 	if (resp->status == nlm_drop_reply)
133 		rc = rpc_drop_reply;
134 	else
135 		dprintk("lockd: TEST          status %d vers %d\n",
136 			ntohl(resp->status), rqstp->rq_vers);
137 
138 	nlm_release_host(host);
139 	nlm_release_file(file);
140 	return rc;
141 }
142 
143 static __be32
144 nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
145 				         struct nlm_res  *resp)
146 {
147 	struct nlm_host	*host;
148 	struct nlm_file	*file;
149 	__be32 rc = rpc_success;
150 
151 	dprintk("lockd: LOCK          called\n");
152 
153 	resp->cookie = argp->cookie;
154 
155 	/* Don't accept new lock requests during grace period */
156 	if (nlmsvc_grace_period && !argp->reclaim) {
157 		resp->status = nlm_lck_denied_grace_period;
158 		return rc;
159 	}
160 
161 	/* Obtain client and file */
162 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
163 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
164 
165 #if 0
166 	/* If supplied state doesn't match current state, we assume it's
167 	 * an old request that time-warped somehow. Any error return would
168 	 * do in this case because it's irrelevant anyway.
169 	 *
170 	 * NB: We don't retrieve the remote host's state yet.
171 	 */
172 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
173 		resp->status = nlm_lck_denied_nolocks;
174 	} else
175 #endif
176 
177 	/* Now try to lock the file */
178 	resp->status = cast_status(nlmsvc_lock(rqstp, file, host, &argp->lock,
179 					       argp->block, &argp->cookie));
180 	if (resp->status == nlm_drop_reply)
181 		rc = rpc_drop_reply;
182 	else
183 		dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
184 
185 	nlm_release_host(host);
186 	nlm_release_file(file);
187 	return rc;
188 }
189 
190 static __be32
191 nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
192 				           struct nlm_res  *resp)
193 {
194 	struct nlm_host	*host;
195 	struct nlm_file	*file;
196 
197 	dprintk("lockd: CANCEL        called\n");
198 
199 	resp->cookie = argp->cookie;
200 
201 	/* Don't accept requests during grace period */
202 	if (nlmsvc_grace_period) {
203 		resp->status = nlm_lck_denied_grace_period;
204 		return rpc_success;
205 	}
206 
207 	/* Obtain client and file */
208 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
209 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
210 
211 	/* Try to cancel request. */
212 	resp->status = cast_status(nlmsvc_cancel_blocked(file, &argp->lock));
213 
214 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
215 	nlm_release_host(host);
216 	nlm_release_file(file);
217 	return rpc_success;
218 }
219 
220 /*
221  * UNLOCK: release a lock
222  */
223 static __be32
224 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
225 				           struct nlm_res  *resp)
226 {
227 	struct nlm_host	*host;
228 	struct nlm_file	*file;
229 
230 	dprintk("lockd: UNLOCK        called\n");
231 
232 	resp->cookie = argp->cookie;
233 
234 	/* Don't accept new lock requests during grace period */
235 	if (nlmsvc_grace_period) {
236 		resp->status = nlm_lck_denied_grace_period;
237 		return rpc_success;
238 	}
239 
240 	/* Obtain client and file */
241 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
242 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
243 
244 	/* Now try to remove the lock */
245 	resp->status = cast_status(nlmsvc_unlock(file, &argp->lock));
246 
247 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
248 	nlm_release_host(host);
249 	nlm_release_file(file);
250 	return rpc_success;
251 }
252 
253 /*
254  * GRANTED: A server calls us to tell that a process' lock request
255  * was granted
256  */
257 static __be32
258 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
259 				            struct nlm_res  *resp)
260 {
261 	resp->cookie = argp->cookie;
262 
263 	dprintk("lockd: GRANTED       called\n");
264 	resp->status = nlmclnt_grant(svc_addr_in(rqstp), &argp->lock);
265 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
266 	return rpc_success;
267 }
268 
269 /*
270  * This is the generic lockd callback for async RPC calls
271  */
272 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
273 {
274 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
275 			-task->tk_status);
276 }
277 
278 static void nlmsvc_callback_release(void *data)
279 {
280 	lock_kernel();
281 	nlm_release_call(data);
282 	unlock_kernel();
283 }
284 
285 static const struct rpc_call_ops nlmsvc_callback_ops = {
286 	.rpc_call_done = nlmsvc_callback_exit,
287 	.rpc_release = nlmsvc_callback_release,
288 };
289 
290 /*
291  * `Async' versions of the above service routines. They aren't really,
292  * because we send the callback before the reply proper. I hope this
293  * doesn't break any clients.
294  */
295 static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
296 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
297 {
298 	struct nlm_host	*host;
299 	struct nlm_rqst	*call;
300 	__be32 stat;
301 
302 	host = nlmsvc_lookup_host(rqstp,
303 				  argp->lock.caller,
304 				  argp->lock.len);
305 	if (host == NULL)
306 		return rpc_system_err;
307 
308 	call = nlm_alloc_call(host);
309 	if (call == NULL)
310 		return rpc_system_err;
311 
312 	stat = func(rqstp, argp, &call->a_res);
313 	if (stat != 0) {
314 		nlm_release_call(call);
315 		return stat;
316 	}
317 
318 	call->a_flags = RPC_TASK_ASYNC;
319 	if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
320 		return rpc_system_err;
321 	return rpc_success;
322 }
323 
324 static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
325 					     void	     *resp)
326 {
327 	dprintk("lockd: TEST_MSG      called\n");
328 	return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
329 }
330 
331 static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
332 					     void	     *resp)
333 {
334 	dprintk("lockd: LOCK_MSG      called\n");
335 	return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
336 }
337 
338 static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
339 					       void	       *resp)
340 {
341 	dprintk("lockd: CANCEL_MSG    called\n");
342 	return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
343 }
344 
345 static __be32
346 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
347                                                void            *resp)
348 {
349 	dprintk("lockd: UNLOCK_MSG    called\n");
350 	return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
351 }
352 
353 static __be32
354 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
355                                                 void            *resp)
356 {
357 	dprintk("lockd: GRANTED_MSG   called\n");
358 	return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
359 }
360 
361 /*
362  * SHARE: create a DOS share or alter existing share.
363  */
364 static __be32
365 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
366 				          struct nlm_res  *resp)
367 {
368 	struct nlm_host	*host;
369 	struct nlm_file	*file;
370 
371 	dprintk("lockd: SHARE         called\n");
372 
373 	resp->cookie = argp->cookie;
374 
375 	/* Don't accept new lock requests during grace period */
376 	if (nlmsvc_grace_period && !argp->reclaim) {
377 		resp->status = nlm_lck_denied_grace_period;
378 		return rpc_success;
379 	}
380 
381 	/* Obtain client and file */
382 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
383 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
384 
385 	/* Now try to create the share */
386 	resp->status = cast_status(nlmsvc_share_file(host, file, argp));
387 
388 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
389 	nlm_release_host(host);
390 	nlm_release_file(file);
391 	return rpc_success;
392 }
393 
394 /*
395  * UNSHARE: Release a DOS share.
396  */
397 static __be32
398 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
399 				            struct nlm_res  *resp)
400 {
401 	struct nlm_host	*host;
402 	struct nlm_file	*file;
403 
404 	dprintk("lockd: UNSHARE       called\n");
405 
406 	resp->cookie = argp->cookie;
407 
408 	/* Don't accept requests during grace period */
409 	if (nlmsvc_grace_period) {
410 		resp->status = nlm_lck_denied_grace_period;
411 		return rpc_success;
412 	}
413 
414 	/* Obtain client and file */
415 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
416 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
417 
418 	/* Now try to unshare the file */
419 	resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
420 
421 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
422 	nlm_release_host(host);
423 	nlm_release_file(file);
424 	return rpc_success;
425 }
426 
427 /*
428  * NM_LOCK: Create an unmonitored lock
429  */
430 static __be32
431 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
432 				            struct nlm_res  *resp)
433 {
434 	dprintk("lockd: NM_LOCK       called\n");
435 
436 	argp->monitor = 0;		/* just clean the monitor flag */
437 	return nlmsvc_proc_lock(rqstp, argp, resp);
438 }
439 
440 /*
441  * FREE_ALL: Release all locks and shares held by client
442  */
443 static __be32
444 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
445 					     void            *resp)
446 {
447 	struct nlm_host	*host;
448 
449 	/* Obtain client */
450 	if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
451 		return rpc_success;
452 
453 	nlmsvc_free_host_resources(host);
454 	nlm_release_host(host);
455 	return rpc_success;
456 }
457 
458 /*
459  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
460  */
461 static __be32
462 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
463 					      void	        *resp)
464 {
465 	struct sockaddr_in	saddr;
466 
467 	memcpy(&saddr, svc_addr_in(rqstp), sizeof(saddr));
468 
469 	dprintk("lockd: SM_NOTIFY     called\n");
470 	if (saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)
471 	 || ntohs(saddr.sin_port) >= 1024) {
472 		char buf[RPC_MAX_ADDRBUFLEN];
473 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
474 				svc_print_addr(rqstp, buf, sizeof(buf)));
475 		return rpc_system_err;
476 	}
477 
478 	/* Obtain the host pointer for this NFS server and try to
479 	 * reclaim all locks we hold on this server.
480 	 */
481 	memset(&saddr, 0, sizeof(saddr));
482 	saddr.sin_addr.s_addr = argp->addr;
483 	nlm_host_rebooted(&saddr, argp->mon, argp->len, argp->state);
484 
485 	return rpc_success;
486 }
487 
488 /*
489  * client sent a GRANTED_RES, let's remove the associated block
490  */
491 static __be32
492 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
493                                                 void            *resp)
494 {
495 	if (!nlmsvc_ops)
496 		return rpc_success;
497 
498 	dprintk("lockd: GRANTED_RES   called\n");
499 
500 	nlmsvc_grant_reply(&argp->cookie, argp->status);
501 	return rpc_success;
502 }
503 
504 /*
505  * NLM Server procedures.
506  */
507 
508 #define nlmsvc_encode_norep	nlmsvc_encode_void
509 #define nlmsvc_decode_norep	nlmsvc_decode_void
510 #define nlmsvc_decode_testres	nlmsvc_decode_void
511 #define nlmsvc_decode_lockres	nlmsvc_decode_void
512 #define nlmsvc_decode_unlockres	nlmsvc_decode_void
513 #define nlmsvc_decode_cancelres	nlmsvc_decode_void
514 #define nlmsvc_decode_grantedres	nlmsvc_decode_void
515 
516 #define nlmsvc_proc_none	nlmsvc_proc_null
517 #define nlmsvc_proc_test_res	nlmsvc_proc_null
518 #define nlmsvc_proc_lock_res	nlmsvc_proc_null
519 #define nlmsvc_proc_cancel_res	nlmsvc_proc_null
520 #define nlmsvc_proc_unlock_res	nlmsvc_proc_null
521 
522 struct nlm_void			{ int dummy; };
523 
524 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
525  { .pc_func	= (svc_procfunc) nlmsvc_proc_##name,	\
526    .pc_decode	= (kxdrproc_t) nlmsvc_decode_##xargt,	\
527    .pc_encode	= (kxdrproc_t) nlmsvc_encode_##xrest,	\
528    .pc_release	= NULL,					\
529    .pc_argsize	= sizeof(struct nlm_##argt),		\
530    .pc_ressize	= sizeof(struct nlm_##rest),		\
531    .pc_xdrressize = respsize,				\
532  }
533 
534 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
535 #define	St	1				/* status */
536 #define	No	(1+1024/4)			/* Net Obj */
537 #define	Rg	2				/* range - offset + size */
538 
539 struct svc_procedure		nlmsvc_procedures[] = {
540   PROC(null,		void,		void,		void,	void, 1),
541   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
542   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
543   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
544   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
545   PROC(granted,		testargs,	res,		args,	res, Ck+St),
546   PROC(test_msg,	testargs,	norep,		args,	void, 1),
547   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
548   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
549   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
550   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
551   PROC(test_res,	testres,	norep,		res,	void, 1),
552   PROC(lock_res,	lockres,	norep,		res,	void, 1),
553   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
554   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
555   PROC(granted_res,	res,		norep,		res,	void, 1),
556   /* statd callback */
557   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
558   PROC(none,		void,		void,		void,	void, 1),
559   PROC(none,		void,		void,		void,	void, 1),
560   PROC(none,		void,		void,		void,	void, 1),
561   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
562   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
563   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
564   PROC(free_all,	notify,		void,		args,	void, 0),
565 
566 };
567