xref: /linux/fs/lockd/svc4proc.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
1 /*
2  * linux/fs/lockd/svc4proc.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/smp_lock.h>
13 #include <linux/lockd/lockd.h>
14 #include <linux/lockd/share.h>
15 
16 #define NLMDBG_FACILITY		NLMDBG_CLIENT
17 
18 /*
19  * Obtain client and file from arguments
20  */
21 static __be32
22 nlm4svc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
23 			struct nlm_host **hostp, struct nlm_file **filp)
24 {
25 	struct nlm_host		*host = NULL;
26 	struct nlm_file		*file = NULL;
27 	struct nlm_lock		*lock = &argp->lock;
28 	__be32			error = 0;
29 
30 	/* nfsd callbacks must have been installed for this procedure */
31 	if (!nlmsvc_ops)
32 		return nlm_lck_denied_nolocks;
33 
34 	/* Obtain host handle */
35 	if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
36 	 || (argp->monitor && nsm_monitor(host) < 0))
37 		goto no_locks;
38 	*hostp = host;
39 
40 	/* Obtain file pointer. Not used by FREE_ALL call. */
41 	if (filp != NULL) {
42 		if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
43 			goto no_locks;
44 		*filp = file;
45 
46 		/* Set up the missing parts of the file_lock structure */
47 		lock->fl.fl_file  = file->f_file;
48 		lock->fl.fl_owner = (fl_owner_t) host;
49 		lock->fl.fl_lmops = &nlmsvc_lock_operations;
50 	}
51 
52 	return 0;
53 
54 no_locks:
55 	nlm_release_host(host);
56  	if (error)
57 		return error;
58 	return nlm_lck_denied_nolocks;
59 }
60 
61 /*
62  * NULL: Test for presence of service
63  */
64 static __be32
65 nlm4svc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
66 {
67 	dprintk("lockd: NULL          called\n");
68 	return rpc_success;
69 }
70 
71 /*
72  * TEST: Check for conflicting lock
73  */
74 static __be32
75 nlm4svc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
76 				         struct nlm_res  *resp)
77 {
78 	struct nlm_host	*host;
79 	struct nlm_file	*file;
80 	__be32 rc = rpc_success;
81 
82 	dprintk("lockd: TEST4        called\n");
83 	resp->cookie = argp->cookie;
84 
85 	/* Obtain client and file */
86 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
87 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
88 
89 	/* Now check for conflicting locks */
90 	resp->status = nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie);
91 	if (resp->status == nlm_drop_reply)
92 		rc = rpc_drop_reply;
93 	else
94 		dprintk("lockd: TEST4        status %d\n", ntohl(resp->status));
95 
96 	nlm_release_host(host);
97 	nlm_release_file(file);
98 	return rc;
99 }
100 
101 static __be32
102 nlm4svc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
103 				         struct nlm_res  *resp)
104 {
105 	struct nlm_host	*host;
106 	struct nlm_file	*file;
107 	__be32 rc = rpc_success;
108 
109 	dprintk("lockd: LOCK          called\n");
110 
111 	resp->cookie = argp->cookie;
112 
113 	/* Obtain client and file */
114 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
115 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
116 
117 #if 0
118 	/* If supplied state doesn't match current state, we assume it's
119 	 * an old request that time-warped somehow. Any error return would
120 	 * do in this case because it's irrelevant anyway.
121 	 *
122 	 * NB: We don't retrieve the remote host's state yet.
123 	 */
124 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
125 		resp->status = nlm_lck_denied_nolocks;
126 	} else
127 #endif
128 
129 	/* Now try to lock the file */
130 	resp->status = nlmsvc_lock(rqstp, file, host, &argp->lock,
131 					argp->block, &argp->cookie,
132 					argp->reclaim);
133 	if (resp->status == nlm_drop_reply)
134 		rc = rpc_drop_reply;
135 	else
136 		dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
137 
138 	nlm_release_host(host);
139 	nlm_release_file(file);
140 	return rc;
141 }
142 
143 static __be32
144 nlm4svc_proc_cancel(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 
150 	dprintk("lockd: CANCEL        called\n");
151 
152 	resp->cookie = argp->cookie;
153 
154 	/* Don't accept requests during grace period */
155 	if (locks_in_grace()) {
156 		resp->status = nlm_lck_denied_grace_period;
157 		return rpc_success;
158 	}
159 
160 	/* Obtain client and file */
161 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
162 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
163 
164 	/* Try to cancel request. */
165 	resp->status = nlmsvc_cancel_blocked(file, &argp->lock);
166 
167 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
168 	nlm_release_host(host);
169 	nlm_release_file(file);
170 	return rpc_success;
171 }
172 
173 /*
174  * UNLOCK: release a lock
175  */
176 static __be32
177 nlm4svc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
178 				           struct nlm_res  *resp)
179 {
180 	struct nlm_host	*host;
181 	struct nlm_file	*file;
182 
183 	dprintk("lockd: UNLOCK        called\n");
184 
185 	resp->cookie = argp->cookie;
186 
187 	/* Don't accept new lock requests during grace period */
188 	if (locks_in_grace()) {
189 		resp->status = nlm_lck_denied_grace_period;
190 		return rpc_success;
191 	}
192 
193 	/* Obtain client and file */
194 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
195 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
196 
197 	/* Now try to remove the lock */
198 	resp->status = nlmsvc_unlock(file, &argp->lock);
199 
200 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
201 	nlm_release_host(host);
202 	nlm_release_file(file);
203 	return rpc_success;
204 }
205 
206 /*
207  * GRANTED: A server calls us to tell that a process' lock request
208  * was granted
209  */
210 static __be32
211 nlm4svc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
212 				            struct nlm_res  *resp)
213 {
214 	resp->cookie = argp->cookie;
215 
216 	dprintk("lockd: GRANTED       called\n");
217 	resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
218 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
219 	return rpc_success;
220 }
221 
222 /*
223  * This is the generic lockd callback for async RPC calls
224  */
225 static void nlm4svc_callback_exit(struct rpc_task *task, void *data)
226 {
227 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
228 			-task->tk_status);
229 }
230 
231 static void nlm4svc_callback_release(void *data)
232 {
233 	lock_kernel();
234 	nlm_release_call(data);
235 	unlock_kernel();
236 }
237 
238 static const struct rpc_call_ops nlm4svc_callback_ops = {
239 	.rpc_call_done = nlm4svc_callback_exit,
240 	.rpc_release = nlm4svc_callback_release,
241 };
242 
243 /*
244  * `Async' versions of the above service routines. They aren't really,
245  * because we send the callback before the reply proper. I hope this
246  * doesn't break any clients.
247  */
248 static __be32 nlm4svc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
249 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
250 {
251 	struct nlm_host	*host;
252 	struct nlm_rqst	*call;
253 	__be32 stat;
254 
255 	host = nlmsvc_lookup_host(rqstp,
256 				  argp->lock.caller,
257 				  argp->lock.len);
258 	if (host == NULL)
259 		return rpc_system_err;
260 
261 	call = nlm_alloc_call(host);
262 	if (call == NULL)
263 		return rpc_system_err;
264 
265 	stat = func(rqstp, argp, &call->a_res);
266 	if (stat != 0) {
267 		nlm_release_call(call);
268 		return stat;
269 	}
270 
271 	call->a_flags = RPC_TASK_ASYNC;
272 	if (nlm_async_reply(call, proc, &nlm4svc_callback_ops) < 0)
273 		return rpc_system_err;
274 	return rpc_success;
275 }
276 
277 static __be32 nlm4svc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
278 					     void	     *resp)
279 {
280 	dprintk("lockd: TEST_MSG      called\n");
281 	return nlm4svc_callback(rqstp, NLMPROC_TEST_RES, argp, nlm4svc_proc_test);
282 }
283 
284 static __be32 nlm4svc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
285 					     void	     *resp)
286 {
287 	dprintk("lockd: LOCK_MSG      called\n");
288 	return nlm4svc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlm4svc_proc_lock);
289 }
290 
291 static __be32 nlm4svc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
292 					       void	       *resp)
293 {
294 	dprintk("lockd: CANCEL_MSG    called\n");
295 	return nlm4svc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlm4svc_proc_cancel);
296 }
297 
298 static __be32 nlm4svc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
299                                                void            *resp)
300 {
301 	dprintk("lockd: UNLOCK_MSG    called\n");
302 	return nlm4svc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlm4svc_proc_unlock);
303 }
304 
305 static __be32 nlm4svc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
306                                                 void            *resp)
307 {
308 	dprintk("lockd: GRANTED_MSG   called\n");
309 	return nlm4svc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlm4svc_proc_granted);
310 }
311 
312 /*
313  * SHARE: create a DOS share or alter existing share.
314  */
315 static __be32
316 nlm4svc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
317 				          struct nlm_res  *resp)
318 {
319 	struct nlm_host	*host;
320 	struct nlm_file	*file;
321 
322 	dprintk("lockd: SHARE         called\n");
323 
324 	resp->cookie = argp->cookie;
325 
326 	/* Don't accept new lock requests during grace period */
327 	if (locks_in_grace() && !argp->reclaim) {
328 		resp->status = nlm_lck_denied_grace_period;
329 		return rpc_success;
330 	}
331 
332 	/* Obtain client and file */
333 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
334 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
335 
336 	/* Now try to create the share */
337 	resp->status = nlmsvc_share_file(host, file, argp);
338 
339 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
340 	nlm_release_host(host);
341 	nlm_release_file(file);
342 	return rpc_success;
343 }
344 
345 /*
346  * UNSHARE: Release a DOS share.
347  */
348 static __be32
349 nlm4svc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
350 				            struct nlm_res  *resp)
351 {
352 	struct nlm_host	*host;
353 	struct nlm_file	*file;
354 
355 	dprintk("lockd: UNSHARE       called\n");
356 
357 	resp->cookie = argp->cookie;
358 
359 	/* Don't accept requests during grace period */
360 	if (locks_in_grace()) {
361 		resp->status = nlm_lck_denied_grace_period;
362 		return rpc_success;
363 	}
364 
365 	/* Obtain client and file */
366 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
367 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
368 
369 	/* Now try to lock the file */
370 	resp->status = nlmsvc_unshare_file(host, file, argp);
371 
372 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
373 	nlm_release_host(host);
374 	nlm_release_file(file);
375 	return rpc_success;
376 }
377 
378 /*
379  * NM_LOCK: Create an unmonitored lock
380  */
381 static __be32
382 nlm4svc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
383 				            struct nlm_res  *resp)
384 {
385 	dprintk("lockd: NM_LOCK       called\n");
386 
387 	argp->monitor = 0;		/* just clean the monitor flag */
388 	return nlm4svc_proc_lock(rqstp, argp, resp);
389 }
390 
391 /*
392  * FREE_ALL: Release all locks and shares held by client
393  */
394 static __be32
395 nlm4svc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
396 					     void            *resp)
397 {
398 	struct nlm_host	*host;
399 
400 	/* Obtain client */
401 	if (nlm4svc_retrieve_args(rqstp, argp, &host, NULL))
402 		return rpc_success;
403 
404 	nlmsvc_free_host_resources(host);
405 	nlm_release_host(host);
406 	return rpc_success;
407 }
408 
409 /*
410  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
411  */
412 static __be32
413 nlm4svc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
414 					      void	        *resp)
415 {
416 	dprintk("lockd: SM_NOTIFY     called\n");
417 
418 	if (!nlm_privileged_requester(rqstp)) {
419 		char buf[RPC_MAX_ADDRBUFLEN];
420 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
421 				svc_print_addr(rqstp, buf, sizeof(buf)));
422 		return rpc_system_err;
423 	}
424 
425 	nlm_host_rebooted(argp);
426 	return rpc_success;
427 }
428 
429 /*
430  * client sent a GRANTED_RES, let's remove the associated block
431  */
432 static __be32
433 nlm4svc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
434                                                 void            *resp)
435 {
436         if (!nlmsvc_ops)
437                 return rpc_success;
438 
439         dprintk("lockd: GRANTED_RES   called\n");
440 
441         nlmsvc_grant_reply(&argp->cookie, argp->status);
442         return rpc_success;
443 }
444 
445 
446 /*
447  * NLM Server procedures.
448  */
449 
450 #define nlm4svc_encode_norep	nlm4svc_encode_void
451 #define nlm4svc_decode_norep	nlm4svc_decode_void
452 #define nlm4svc_decode_testres	nlm4svc_decode_void
453 #define nlm4svc_decode_lockres	nlm4svc_decode_void
454 #define nlm4svc_decode_unlockres	nlm4svc_decode_void
455 #define nlm4svc_decode_cancelres	nlm4svc_decode_void
456 #define nlm4svc_decode_grantedres	nlm4svc_decode_void
457 
458 #define nlm4svc_proc_none	nlm4svc_proc_null
459 #define nlm4svc_proc_test_res	nlm4svc_proc_null
460 #define nlm4svc_proc_lock_res	nlm4svc_proc_null
461 #define nlm4svc_proc_cancel_res	nlm4svc_proc_null
462 #define nlm4svc_proc_unlock_res	nlm4svc_proc_null
463 
464 struct nlm_void			{ int dummy; };
465 
466 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
467  { .pc_func	= (svc_procfunc) nlm4svc_proc_##name,	\
468    .pc_decode	= (kxdrproc_t) nlm4svc_decode_##xargt,	\
469    .pc_encode	= (kxdrproc_t) nlm4svc_encode_##xrest,	\
470    .pc_release	= NULL,					\
471    .pc_argsize	= sizeof(struct nlm_##argt),		\
472    .pc_ressize	= sizeof(struct nlm_##rest),		\
473    .pc_xdrressize = respsize,				\
474  }
475 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
476 #define	No	(1+1024/4)				/* netobj */
477 #define	St	1					/* status */
478 #define	Rg	4					/* range (offset + length) */
479 struct svc_procedure		nlmsvc_procedures4[] = {
480   PROC(null,		void,		void,		void,	void, 1),
481   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
482   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
483   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
484   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
485   PROC(granted,		testargs,	res,		args,	res, Ck+St),
486   PROC(test_msg,	testargs,	norep,		args,	void, 1),
487   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
488   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
489   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
490   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
491   PROC(test_res,	testres,	norep,		res,	void, 1),
492   PROC(lock_res,	lockres,	norep,		res,	void, 1),
493   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
494   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
495   PROC(granted_res,	res,		norep,		res,	void, 1),
496   /* statd callback */
497   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
498   PROC(none,		void,		void,		void,	void, 0),
499   PROC(none,		void,		void,		void,	void, 0),
500   PROC(none,		void,		void,		void,	void, 0),
501   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
502   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
503   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
504   PROC(free_all,	notify,		void,		args,	void, 1),
505 
506 };
507