xref: /openbmc/linux/fs/lockd/svc4proc.c (revision 95298d63)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/fs/lockd/svc4proc.c
4  *
5  * Lockd server procedures. We don't implement the NLM_*_RES
6  * procedures because we don't use the async procedures.
7  *
8  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
9  */
10 
11 #include <linux/types.h>
12 #include <linux/time.h>
13 #include <linux/lockd/lockd.h>
14 #include <linux/lockd/share.h>
15 #include <linux/sunrpc/svc_xprt.h>
16 
17 #define NLMDBG_FACILITY		NLMDBG_CLIENT
18 
19 /*
20  * Obtain client and file from arguments
21  */
22 static __be32
23 nlm4svc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
24 			struct nlm_host **hostp, struct nlm_file **filp)
25 {
26 	struct nlm_host		*host = NULL;
27 	struct nlm_file		*file = NULL;
28 	struct nlm_lock		*lock = &argp->lock;
29 	__be32			error = 0;
30 
31 	/* nfsd callbacks must have been installed for this procedure */
32 	if (!nlmsvc_ops)
33 		return nlm_lck_denied_nolocks;
34 
35 	/* Obtain host handle */
36 	if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
37 	 || (argp->monitor && nsm_monitor(host) < 0))
38 		goto no_locks;
39 	*hostp = host;
40 
41 	/* Obtain file pointer. Not used by FREE_ALL call. */
42 	if (filp != NULL) {
43 		if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
44 			goto no_locks;
45 		*filp = file;
46 
47 		/* Set up the missing parts of the file_lock structure */
48 		lock->fl.fl_file  = file->f_file;
49 		lock->fl.fl_pid = current->tgid;
50 		lock->fl.fl_lmops = &nlmsvc_lock_operations;
51 		nlmsvc_locks_init_private(&lock->fl, host, (pid_t)lock->svid);
52 		if (!lock->fl.fl_owner) {
53 			/* lockowner allocation has failed */
54 			nlmsvc_release_host(host);
55 			return nlm_lck_denied_nolocks;
56 		}
57 	}
58 
59 	return 0;
60 
61 no_locks:
62 	nlmsvc_release_host(host);
63  	if (error)
64 		return error;
65 	return nlm_lck_denied_nolocks;
66 }
67 
68 /*
69  * NULL: Test for presence of service
70  */
71 static __be32
72 nlm4svc_proc_null(struct svc_rqst *rqstp)
73 {
74 	dprintk("lockd: NULL          called\n");
75 	return rpc_success;
76 }
77 
78 /*
79  * TEST: Check for conflicting lock
80  */
81 static __be32
82 __nlm4svc_proc_test(struct svc_rqst *rqstp, struct nlm_res *resp)
83 {
84 	struct nlm_args *argp = rqstp->rq_argp;
85 	struct nlm_host	*host;
86 	struct nlm_file	*file;
87 	__be32 rc = rpc_success;
88 
89 	dprintk("lockd: TEST4        called\n");
90 	resp->cookie = argp->cookie;
91 
92 	/* Obtain client and file */
93 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
94 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
95 
96 	/* Now check for conflicting locks */
97 	resp->status = nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie);
98 	if (resp->status == nlm_drop_reply)
99 		rc = rpc_drop_reply;
100 	else
101 		dprintk("lockd: TEST4        status %d\n", ntohl(resp->status));
102 
103 	nlmsvc_release_lockowner(&argp->lock);
104 	nlmsvc_release_host(host);
105 	nlm_release_file(file);
106 	return rc;
107 }
108 
109 static __be32
110 nlm4svc_proc_test(struct svc_rqst *rqstp)
111 {
112 	return __nlm4svc_proc_test(rqstp, rqstp->rq_resp);
113 }
114 
115 static __be32
116 __nlm4svc_proc_lock(struct svc_rqst *rqstp, struct nlm_res *resp)
117 {
118 	struct nlm_args *argp = rqstp->rq_argp;
119 	struct nlm_host	*host;
120 	struct nlm_file	*file;
121 	__be32 rc = rpc_success;
122 
123 	dprintk("lockd: LOCK          called\n");
124 
125 	resp->cookie = argp->cookie;
126 
127 	/* Obtain client and file */
128 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
129 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
130 
131 #if 0
132 	/* If supplied state doesn't match current state, we assume it's
133 	 * an old request that time-warped somehow. Any error return would
134 	 * do in this case because it's irrelevant anyway.
135 	 *
136 	 * NB: We don't retrieve the remote host's state yet.
137 	 */
138 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
139 		resp->status = nlm_lck_denied_nolocks;
140 	} else
141 #endif
142 
143 	/* Now try to lock the file */
144 	resp->status = nlmsvc_lock(rqstp, file, host, &argp->lock,
145 					argp->block, &argp->cookie,
146 					argp->reclaim);
147 	if (resp->status == nlm_drop_reply)
148 		rc = rpc_drop_reply;
149 	else
150 		dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
151 
152 	nlmsvc_release_lockowner(&argp->lock);
153 	nlmsvc_release_host(host);
154 	nlm_release_file(file);
155 	return rc;
156 }
157 
158 static __be32
159 nlm4svc_proc_lock(struct svc_rqst *rqstp)
160 {
161 	return __nlm4svc_proc_lock(rqstp, rqstp->rq_resp);
162 }
163 
164 static __be32
165 __nlm4svc_proc_cancel(struct svc_rqst *rqstp, struct nlm_res *resp)
166 {
167 	struct nlm_args *argp = rqstp->rq_argp;
168 	struct nlm_host	*host;
169 	struct nlm_file	*file;
170 
171 	dprintk("lockd: CANCEL        called\n");
172 
173 	resp->cookie = argp->cookie;
174 
175 	/* Don't accept requests during grace period */
176 	if (locks_in_grace(SVC_NET(rqstp))) {
177 		resp->status = nlm_lck_denied_grace_period;
178 		return rpc_success;
179 	}
180 
181 	/* Obtain client and file */
182 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
183 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
184 
185 	/* Try to cancel request. */
186 	resp->status = nlmsvc_cancel_blocked(SVC_NET(rqstp), file, &argp->lock);
187 
188 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
189 	nlmsvc_release_lockowner(&argp->lock);
190 	nlmsvc_release_host(host);
191 	nlm_release_file(file);
192 	return rpc_success;
193 }
194 
195 static __be32
196 nlm4svc_proc_cancel(struct svc_rqst *rqstp)
197 {
198 	return __nlm4svc_proc_cancel(rqstp, rqstp->rq_resp);
199 }
200 
201 /*
202  * UNLOCK: release a lock
203  */
204 static __be32
205 __nlm4svc_proc_unlock(struct svc_rqst *rqstp, struct nlm_res *resp)
206 {
207 	struct nlm_args *argp = rqstp->rq_argp;
208 	struct nlm_host	*host;
209 	struct nlm_file	*file;
210 
211 	dprintk("lockd: UNLOCK        called\n");
212 
213 	resp->cookie = argp->cookie;
214 
215 	/* Don't accept new lock requests during grace period */
216 	if (locks_in_grace(SVC_NET(rqstp))) {
217 		resp->status = nlm_lck_denied_grace_period;
218 		return rpc_success;
219 	}
220 
221 	/* Obtain client and file */
222 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
223 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
224 
225 	/* Now try to remove the lock */
226 	resp->status = nlmsvc_unlock(SVC_NET(rqstp), file, &argp->lock);
227 
228 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
229 	nlmsvc_release_lockowner(&argp->lock);
230 	nlmsvc_release_host(host);
231 	nlm_release_file(file);
232 	return rpc_success;
233 }
234 
235 static __be32
236 nlm4svc_proc_unlock(struct svc_rqst *rqstp)
237 {
238 	return __nlm4svc_proc_unlock(rqstp, rqstp->rq_resp);
239 }
240 
241 /*
242  * GRANTED: A server calls us to tell that a process' lock request
243  * was granted
244  */
245 static __be32
246 __nlm4svc_proc_granted(struct svc_rqst *rqstp, struct nlm_res *resp)
247 {
248 	struct nlm_args *argp = rqstp->rq_argp;
249 
250 	resp->cookie = argp->cookie;
251 
252 	dprintk("lockd: GRANTED       called\n");
253 	resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
254 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
255 	return rpc_success;
256 }
257 
258 static __be32
259 nlm4svc_proc_granted(struct svc_rqst *rqstp)
260 {
261 	return __nlm4svc_proc_granted(rqstp, rqstp->rq_resp);
262 }
263 
264 /*
265  * This is the generic lockd callback for async RPC calls
266  */
267 static void nlm4svc_callback_exit(struct rpc_task *task, void *data)
268 {
269 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
270 			-task->tk_status);
271 }
272 
273 static void nlm4svc_callback_release(void *data)
274 {
275 	nlmsvc_release_call(data);
276 }
277 
278 static const struct rpc_call_ops nlm4svc_callback_ops = {
279 	.rpc_call_done = nlm4svc_callback_exit,
280 	.rpc_release = nlm4svc_callback_release,
281 };
282 
283 /*
284  * `Async' versions of the above service routines. They aren't really,
285  * because we send the callback before the reply proper. I hope this
286  * doesn't break any clients.
287  */
288 static __be32 nlm4svc_callback(struct svc_rqst *rqstp, u32 proc,
289 		__be32 (*func)(struct svc_rqst *,  struct nlm_res *))
290 {
291 	struct nlm_args *argp = rqstp->rq_argp;
292 	struct nlm_host	*host;
293 	struct nlm_rqst	*call;
294 	__be32 stat;
295 
296 	host = nlmsvc_lookup_host(rqstp,
297 				  argp->lock.caller,
298 				  argp->lock.len);
299 	if (host == NULL)
300 		return rpc_system_err;
301 
302 	call = nlm_alloc_call(host);
303 	nlmsvc_release_host(host);
304 	if (call == NULL)
305 		return rpc_system_err;
306 
307 	stat = func(rqstp, &call->a_res);
308 	if (stat != 0) {
309 		nlmsvc_release_call(call);
310 		return stat;
311 	}
312 
313 	call->a_flags = RPC_TASK_ASYNC;
314 	if (nlm_async_reply(call, proc, &nlm4svc_callback_ops) < 0)
315 		return rpc_system_err;
316 	return rpc_success;
317 }
318 
319 static __be32 nlm4svc_proc_test_msg(struct svc_rqst *rqstp)
320 {
321 	dprintk("lockd: TEST_MSG      called\n");
322 	return nlm4svc_callback(rqstp, NLMPROC_TEST_RES, __nlm4svc_proc_test);
323 }
324 
325 static __be32 nlm4svc_proc_lock_msg(struct svc_rqst *rqstp)
326 {
327 	dprintk("lockd: LOCK_MSG      called\n");
328 	return nlm4svc_callback(rqstp, NLMPROC_LOCK_RES, __nlm4svc_proc_lock);
329 }
330 
331 static __be32 nlm4svc_proc_cancel_msg(struct svc_rqst *rqstp)
332 {
333 	dprintk("lockd: CANCEL_MSG    called\n");
334 	return nlm4svc_callback(rqstp, NLMPROC_CANCEL_RES, __nlm4svc_proc_cancel);
335 }
336 
337 static __be32 nlm4svc_proc_unlock_msg(struct svc_rqst *rqstp)
338 {
339 	dprintk("lockd: UNLOCK_MSG    called\n");
340 	return nlm4svc_callback(rqstp, NLMPROC_UNLOCK_RES, __nlm4svc_proc_unlock);
341 }
342 
343 static __be32 nlm4svc_proc_granted_msg(struct svc_rqst *rqstp)
344 {
345 	dprintk("lockd: GRANTED_MSG   called\n");
346 	return nlm4svc_callback(rqstp, NLMPROC_GRANTED_RES, __nlm4svc_proc_granted);
347 }
348 
349 /*
350  * SHARE: create a DOS share or alter existing share.
351  */
352 static __be32
353 nlm4svc_proc_share(struct svc_rqst *rqstp)
354 {
355 	struct nlm_args *argp = rqstp->rq_argp;
356 	struct nlm_res *resp = rqstp->rq_resp;
357 	struct nlm_host	*host;
358 	struct nlm_file	*file;
359 
360 	dprintk("lockd: SHARE         called\n");
361 
362 	resp->cookie = argp->cookie;
363 
364 	/* Don't accept new lock requests during grace period */
365 	if (locks_in_grace(SVC_NET(rqstp)) && !argp->reclaim) {
366 		resp->status = nlm_lck_denied_grace_period;
367 		return rpc_success;
368 	}
369 
370 	/* Obtain client and file */
371 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
372 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
373 
374 	/* Now try to create the share */
375 	resp->status = nlmsvc_share_file(host, file, argp);
376 
377 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
378 	nlmsvc_release_lockowner(&argp->lock);
379 	nlmsvc_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 nlm4svc_proc_unshare(struct svc_rqst *rqstp)
389 {
390 	struct nlm_args *argp = rqstp->rq_argp;
391 	struct nlm_res *resp = rqstp->rq_resp;
392 	struct nlm_host	*host;
393 	struct nlm_file	*file;
394 
395 	dprintk("lockd: UNSHARE       called\n");
396 
397 	resp->cookie = argp->cookie;
398 
399 	/* Don't accept requests during grace period */
400 	if (locks_in_grace(SVC_NET(rqstp))) {
401 		resp->status = nlm_lck_denied_grace_period;
402 		return rpc_success;
403 	}
404 
405 	/* Obtain client and file */
406 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
407 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
408 
409 	/* Now try to lock the file */
410 	resp->status = nlmsvc_unshare_file(host, file, argp);
411 
412 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
413 	nlmsvc_release_lockowner(&argp->lock);
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 nlm4svc_proc_nm_lock(struct svc_rqst *rqstp)
424 {
425 	struct nlm_args *argp = rqstp->rq_argp;
426 
427 	dprintk("lockd: NM_LOCK       called\n");
428 
429 	argp->monitor = 0;		/* just clean the monitor flag */
430 	return nlm4svc_proc_lock(rqstp);
431 }
432 
433 /*
434  * FREE_ALL: Release all locks and shares held by client
435  */
436 static __be32
437 nlm4svc_proc_free_all(struct svc_rqst *rqstp)
438 {
439 	struct nlm_args *argp = rqstp->rq_argp;
440 	struct nlm_host	*host;
441 
442 	/* Obtain client */
443 	if (nlm4svc_retrieve_args(rqstp, argp, &host, NULL))
444 		return rpc_success;
445 
446 	nlmsvc_free_host_resources(host);
447 	nlmsvc_release_host(host);
448 	return rpc_success;
449 }
450 
451 /*
452  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
453  */
454 static __be32
455 nlm4svc_proc_sm_notify(struct svc_rqst *rqstp)
456 {
457 	struct nlm_reboot *argp = rqstp->rq_argp;
458 
459 	dprintk("lockd: SM_NOTIFY     called\n");
460 
461 	if (!nlm_privileged_requester(rqstp)) {
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 	nlm_host_rebooted(SVC_NET(rqstp), argp);
469 	return rpc_success;
470 }
471 
472 /*
473  * client sent a GRANTED_RES, let's remove the associated block
474  */
475 static __be32
476 nlm4svc_proc_granted_res(struct svc_rqst *rqstp)
477 {
478 	struct nlm_res *argp = rqstp->rq_argp;
479 
480         if (!nlmsvc_ops)
481                 return rpc_success;
482 
483         dprintk("lockd: GRANTED_RES   called\n");
484 
485         nlmsvc_grant_reply(&argp->cookie, argp->status);
486         return rpc_success;
487 }
488 
489 
490 /*
491  * NLM Server procedures.
492  */
493 
494 #define nlm4svc_encode_norep	nlm4svc_encode_void
495 #define nlm4svc_decode_norep	nlm4svc_decode_void
496 #define nlm4svc_decode_testres	nlm4svc_decode_void
497 #define nlm4svc_decode_lockres	nlm4svc_decode_void
498 #define nlm4svc_decode_unlockres	nlm4svc_decode_void
499 #define nlm4svc_decode_cancelres	nlm4svc_decode_void
500 #define nlm4svc_decode_grantedres	nlm4svc_decode_void
501 
502 #define nlm4svc_proc_none	nlm4svc_proc_null
503 #define nlm4svc_proc_test_res	nlm4svc_proc_null
504 #define nlm4svc_proc_lock_res	nlm4svc_proc_null
505 #define nlm4svc_proc_cancel_res	nlm4svc_proc_null
506 #define nlm4svc_proc_unlock_res	nlm4svc_proc_null
507 
508 struct nlm_void			{ int dummy; };
509 
510 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
511  { .pc_func	= nlm4svc_proc_##name,	\
512    .pc_decode	= nlm4svc_decode_##xargt,	\
513    .pc_encode	= nlm4svc_encode_##xrest,	\
514    .pc_release	= NULL,					\
515    .pc_argsize	= sizeof(struct nlm_##argt),		\
516    .pc_ressize	= sizeof(struct nlm_##rest),		\
517    .pc_xdrressize = respsize,				\
518  }
519 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
520 #define	No	(1+1024/4)				/* netobj */
521 #define	St	1					/* status */
522 #define	Rg	4					/* range (offset + length) */
523 const struct svc_procedure nlmsvc_procedures4[] = {
524   PROC(null,		void,		void,		void,	void, 1),
525   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
526   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
527   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
528   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
529   PROC(granted,		testargs,	res,		args,	res, Ck+St),
530   PROC(test_msg,	testargs,	norep,		args,	void, 1),
531   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
532   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
533   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
534   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
535   PROC(test_res,	testres,	norep,		res,	void, 1),
536   PROC(lock_res,	lockres,	norep,		res,	void, 1),
537   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
538   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
539   PROC(granted_res,	res,		norep,		res,	void, 1),
540   /* statd callback */
541   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
542   PROC(none,		void,		void,		void,	void, 0),
543   PROC(none,		void,		void,		void,	void, 0),
544   PROC(none,		void,		void,		void,	void, 0),
545   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
546   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
547   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
548   PROC(free_all,	notify,		void,		args,	void, 1),
549 
550 };
551