xref: /openbmc/linux/fs/lockd/svcproc.c (revision 37185b33)
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/lockd/lockd.h>
13 #include <linux/lockd/share.h>
14 #include <linux/sunrpc/svc_xprt.h>
15 
16 #define NLMDBG_FACILITY		NLMDBG_CLIENT
17 
18 #ifdef CONFIG_LOCKD_V4
19 static __be32
20 cast_to_nlm(__be32 status, u32 vers)
21 {
22 	/* Note: status is assumed to be in network byte order !!! */
23 	if (vers != 4){
24 		switch (status) {
25 		case nlm_granted:
26 		case nlm_lck_denied:
27 		case nlm_lck_denied_nolocks:
28 		case nlm_lck_blocked:
29 		case nlm_lck_denied_grace_period:
30 		case nlm_drop_reply:
31 			break;
32 		case nlm4_deadlock:
33 			status = nlm_lck_denied;
34 			break;
35 		default:
36 			status = nlm_lck_denied_nolocks;
37 		}
38 	}
39 
40 	return (status);
41 }
42 #define	cast_status(status) (cast_to_nlm(status, rqstp->rq_vers))
43 #else
44 #define cast_status(status) (status)
45 #endif
46 
47 /*
48  * Obtain client and file from arguments
49  */
50 static __be32
51 nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
52 			struct nlm_host **hostp, struct nlm_file **filp)
53 {
54 	struct nlm_host		*host = NULL;
55 	struct nlm_file		*file = NULL;
56 	struct nlm_lock		*lock = &argp->lock;
57 	__be32			error = 0;
58 
59 	/* nfsd callbacks must have been installed for this procedure */
60 	if (!nlmsvc_ops)
61 		return nlm_lck_denied_nolocks;
62 
63 	/* Obtain host handle */
64 	if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
65 	 || (argp->monitor && nsm_monitor(host) < 0))
66 		goto no_locks;
67 	*hostp = host;
68 
69 	/* Obtain file pointer. Not used by FREE_ALL call. */
70 	if (filp != NULL) {
71 		if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
72 			goto no_locks;
73 		*filp = file;
74 
75 		/* Set up the missing parts of the file_lock structure */
76 		lock->fl.fl_file  = file->f_file;
77 		lock->fl.fl_owner = (fl_owner_t) host;
78 		lock->fl.fl_lmops = &nlmsvc_lock_operations;
79 	}
80 
81 	return 0;
82 
83 no_locks:
84 	nlmsvc_release_host(host);
85 	if (error)
86 		return error;
87 	return nlm_lck_denied_nolocks;
88 }
89 
90 /*
91  * NULL: Test for presence of service
92  */
93 static __be32
94 nlmsvc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
95 {
96 	dprintk("lockd: NULL          called\n");
97 	return rpc_success;
98 }
99 
100 /*
101  * TEST: Check for conflicting lock
102  */
103 static __be32
104 nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
105 				         struct nlm_res  *resp)
106 {
107 	struct nlm_host	*host;
108 	struct nlm_file	*file;
109 	__be32 rc = rpc_success;
110 
111 	dprintk("lockd: TEST          called\n");
112 	resp->cookie = argp->cookie;
113 
114 	/* Obtain client and file */
115 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
116 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
117 
118 	/* Now check for conflicting locks */
119 	resp->status = cast_status(nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie));
120 	if (resp->status == nlm_drop_reply)
121 		rc = rpc_drop_reply;
122 	else
123 		dprintk("lockd: TEST          status %d vers %d\n",
124 			ntohl(resp->status), rqstp->rq_vers);
125 
126 	nlmsvc_release_host(host);
127 	nlm_release_file(file);
128 	return rc;
129 }
130 
131 static __be32
132 nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
133 				         struct nlm_res  *resp)
134 {
135 	struct nlm_host	*host;
136 	struct nlm_file	*file;
137 	__be32 rc = rpc_success;
138 
139 	dprintk("lockd: LOCK          called\n");
140 
141 	resp->cookie = argp->cookie;
142 
143 	/* Obtain client and file */
144 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
145 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
146 
147 #if 0
148 	/* If supplied state doesn't match current state, we assume it's
149 	 * an old request that time-warped somehow. Any error return would
150 	 * do in this case because it's irrelevant anyway.
151 	 *
152 	 * NB: We don't retrieve the remote host's state yet.
153 	 */
154 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
155 		resp->status = nlm_lck_denied_nolocks;
156 	} else
157 #endif
158 
159 	/* Now try to lock the file */
160 	resp->status = cast_status(nlmsvc_lock(rqstp, file, host, &argp->lock,
161 					       argp->block, &argp->cookie,
162 					       argp->reclaim));
163 	if (resp->status == nlm_drop_reply)
164 		rc = rpc_drop_reply;
165 	else
166 		dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
167 
168 	nlmsvc_release_host(host);
169 	nlm_release_file(file);
170 	return rc;
171 }
172 
173 static __be32
174 nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
175 				           struct nlm_res  *resp)
176 {
177 	struct nlm_host	*host;
178 	struct nlm_file	*file;
179 	struct net *net = SVC_NET(rqstp);
180 
181 	dprintk("lockd: CANCEL        called\n");
182 
183 	resp->cookie = argp->cookie;
184 
185 	/* Don't accept requests during grace period */
186 	if (locks_in_grace(net)) {
187 		resp->status = nlm_lck_denied_grace_period;
188 		return rpc_success;
189 	}
190 
191 	/* Obtain client and file */
192 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
193 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
194 
195 	/* Try to cancel request. */
196 	resp->status = cast_status(nlmsvc_cancel_blocked(net, file, &argp->lock));
197 
198 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
199 	nlmsvc_release_host(host);
200 	nlm_release_file(file);
201 	return rpc_success;
202 }
203 
204 /*
205  * UNLOCK: release a lock
206  */
207 static __be32
208 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
209 				           struct nlm_res  *resp)
210 {
211 	struct nlm_host	*host;
212 	struct nlm_file	*file;
213 	struct net *net = SVC_NET(rqstp);
214 
215 	dprintk("lockd: UNLOCK        called\n");
216 
217 	resp->cookie = argp->cookie;
218 
219 	/* Don't accept new lock requests during grace period */
220 	if (locks_in_grace(net)) {
221 		resp->status = nlm_lck_denied_grace_period;
222 		return rpc_success;
223 	}
224 
225 	/* Obtain client and file */
226 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
227 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
228 
229 	/* Now try to remove the lock */
230 	resp->status = cast_status(nlmsvc_unlock(net, file, &argp->lock));
231 
232 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
233 	nlmsvc_release_host(host);
234 	nlm_release_file(file);
235 	return rpc_success;
236 }
237 
238 /*
239  * GRANTED: A server calls us to tell that a process' lock request
240  * was granted
241  */
242 static __be32
243 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
244 				            struct nlm_res  *resp)
245 {
246 	resp->cookie = argp->cookie;
247 
248 	dprintk("lockd: GRANTED       called\n");
249 	resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
250 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
251 	return rpc_success;
252 }
253 
254 /*
255  * This is the generic lockd callback for async RPC calls
256  */
257 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
258 {
259 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
260 			-task->tk_status);
261 }
262 
263 void nlmsvc_release_call(struct nlm_rqst *call)
264 {
265 	if (!atomic_dec_and_test(&call->a_count))
266 		return;
267 	nlmsvc_release_host(call->a_host);
268 	kfree(call);
269 }
270 
271 static void nlmsvc_callback_release(void *data)
272 {
273 	nlmsvc_release_call(data);
274 }
275 
276 static const struct rpc_call_ops nlmsvc_callback_ops = {
277 	.rpc_call_done = nlmsvc_callback_exit,
278 	.rpc_release = nlmsvc_callback_release,
279 };
280 
281 /*
282  * `Async' versions of the above service routines. They aren't really,
283  * because we send the callback before the reply proper. I hope this
284  * doesn't break any clients.
285  */
286 static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
287 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
288 {
289 	struct nlm_host	*host;
290 	struct nlm_rqst	*call;
291 	__be32 stat;
292 
293 	host = nlmsvc_lookup_host(rqstp,
294 				  argp->lock.caller,
295 				  argp->lock.len);
296 	if (host == NULL)
297 		return rpc_system_err;
298 
299 	call = nlm_alloc_call(host);
300 	nlmsvc_release_host(host);
301 	if (call == NULL)
302 		return rpc_system_err;
303 
304 	stat = func(rqstp, argp, &call->a_res);
305 	if (stat != 0) {
306 		nlmsvc_release_call(call);
307 		return stat;
308 	}
309 
310 	call->a_flags = RPC_TASK_ASYNC;
311 	if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
312 		return rpc_system_err;
313 	return rpc_success;
314 }
315 
316 static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
317 					     void	     *resp)
318 {
319 	dprintk("lockd: TEST_MSG      called\n");
320 	return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
321 }
322 
323 static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
324 					     void	     *resp)
325 {
326 	dprintk("lockd: LOCK_MSG      called\n");
327 	return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
328 }
329 
330 static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
331 					       void	       *resp)
332 {
333 	dprintk("lockd: CANCEL_MSG    called\n");
334 	return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
335 }
336 
337 static __be32
338 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
339                                                void            *resp)
340 {
341 	dprintk("lockd: UNLOCK_MSG    called\n");
342 	return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
343 }
344 
345 static __be32
346 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
347                                                 void            *resp)
348 {
349 	dprintk("lockd: GRANTED_MSG   called\n");
350 	return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
351 }
352 
353 /*
354  * SHARE: create a DOS share or alter existing share.
355  */
356 static __be32
357 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
358 				          struct nlm_res  *resp)
359 {
360 	struct nlm_host	*host;
361 	struct nlm_file	*file;
362 
363 	dprintk("lockd: SHARE         called\n");
364 
365 	resp->cookie = argp->cookie;
366 
367 	/* Don't accept new lock requests during grace period */
368 	if (locks_in_grace(SVC_NET(rqstp)) && !argp->reclaim) {
369 		resp->status = nlm_lck_denied_grace_period;
370 		return rpc_success;
371 	}
372 
373 	/* Obtain client and file */
374 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
375 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
376 
377 	/* Now try to create the share */
378 	resp->status = cast_status(nlmsvc_share_file(host, file, argp));
379 
380 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
381 	nlmsvc_release_host(host);
382 	nlm_release_file(file);
383 	return rpc_success;
384 }
385 
386 /*
387  * UNSHARE: Release a DOS share.
388  */
389 static __be32
390 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
391 				            struct nlm_res  *resp)
392 {
393 	struct nlm_host	*host;
394 	struct nlm_file	*file;
395 
396 	dprintk("lockd: UNSHARE       called\n");
397 
398 	resp->cookie = argp->cookie;
399 
400 	/* Don't accept requests during grace period */
401 	if (locks_in_grace(SVC_NET(rqstp))) {
402 		resp->status = nlm_lck_denied_grace_period;
403 		return rpc_success;
404 	}
405 
406 	/* Obtain client and file */
407 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
408 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
409 
410 	/* Now try to unshare the file */
411 	resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
412 
413 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
414 	nlmsvc_release_host(host);
415 	nlm_release_file(file);
416 	return rpc_success;
417 }
418 
419 /*
420  * NM_LOCK: Create an unmonitored lock
421  */
422 static __be32
423 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
424 				            struct nlm_res  *resp)
425 {
426 	dprintk("lockd: NM_LOCK       called\n");
427 
428 	argp->monitor = 0;		/* just clean the monitor flag */
429 	return nlmsvc_proc_lock(rqstp, argp, resp);
430 }
431 
432 /*
433  * FREE_ALL: Release all locks and shares held by client
434  */
435 static __be32
436 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
437 					     void            *resp)
438 {
439 	struct nlm_host	*host;
440 
441 	/* Obtain client */
442 	if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
443 		return rpc_success;
444 
445 	nlmsvc_free_host_resources(host);
446 	nlmsvc_release_host(host);
447 	return rpc_success;
448 }
449 
450 /*
451  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
452  */
453 static __be32
454 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
455 					      void	        *resp)
456 {
457 	dprintk("lockd: SM_NOTIFY     called\n");
458 
459 	if (!nlm_privileged_requester(rqstp)) {
460 		char buf[RPC_MAX_ADDRBUFLEN];
461 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
462 				svc_print_addr(rqstp, buf, sizeof(buf)));
463 		return rpc_system_err;
464 	}
465 
466 	nlm_host_rebooted(argp);
467 	return rpc_success;
468 }
469 
470 /*
471  * client sent a GRANTED_RES, let's remove the associated block
472  */
473 static __be32
474 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
475                                                 void            *resp)
476 {
477 	if (!nlmsvc_ops)
478 		return rpc_success;
479 
480 	dprintk("lockd: GRANTED_RES   called\n");
481 
482 	nlmsvc_grant_reply(&argp->cookie, argp->status);
483 	return rpc_success;
484 }
485 
486 /*
487  * NLM Server procedures.
488  */
489 
490 #define nlmsvc_encode_norep	nlmsvc_encode_void
491 #define nlmsvc_decode_norep	nlmsvc_decode_void
492 #define nlmsvc_decode_testres	nlmsvc_decode_void
493 #define nlmsvc_decode_lockres	nlmsvc_decode_void
494 #define nlmsvc_decode_unlockres	nlmsvc_decode_void
495 #define nlmsvc_decode_cancelres	nlmsvc_decode_void
496 #define nlmsvc_decode_grantedres	nlmsvc_decode_void
497 
498 #define nlmsvc_proc_none	nlmsvc_proc_null
499 #define nlmsvc_proc_test_res	nlmsvc_proc_null
500 #define nlmsvc_proc_lock_res	nlmsvc_proc_null
501 #define nlmsvc_proc_cancel_res	nlmsvc_proc_null
502 #define nlmsvc_proc_unlock_res	nlmsvc_proc_null
503 
504 struct nlm_void			{ int dummy; };
505 
506 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
507  { .pc_func	= (svc_procfunc) nlmsvc_proc_##name,	\
508    .pc_decode	= (kxdrproc_t) nlmsvc_decode_##xargt,	\
509    .pc_encode	= (kxdrproc_t) nlmsvc_encode_##xrest,	\
510    .pc_release	= NULL,					\
511    .pc_argsize	= sizeof(struct nlm_##argt),		\
512    .pc_ressize	= sizeof(struct nlm_##rest),		\
513    .pc_xdrressize = respsize,				\
514  }
515 
516 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
517 #define	St	1				/* status */
518 #define	No	(1+1024/4)			/* Net Obj */
519 #define	Rg	2				/* range - offset + size */
520 
521 struct svc_procedure		nlmsvc_procedures[] = {
522   PROC(null,		void,		void,		void,	void, 1),
523   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
524   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
525   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
526   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
527   PROC(granted,		testargs,	res,		args,	res, Ck+St),
528   PROC(test_msg,	testargs,	norep,		args,	void, 1),
529   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
530   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
531   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
532   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
533   PROC(test_res,	testres,	norep,		res,	void, 1),
534   PROC(lock_res,	lockres,	norep,		res,	void, 1),
535   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
536   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
537   PROC(granted_res,	res,		norep,		res,	void, 1),
538   /* statd callback */
539   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
540   PROC(none,		void,		void,		void,	void, 1),
541   PROC(none,		void,		void,		void,	void, 1),
542   PROC(none,		void,		void,		void,	void, 1),
543   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
544   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
545   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
546   PROC(free_all,	notify,		void,		args,	void, 0),
547 
548 };
549