xref: /openbmc/linux/fs/lockd/svc4proc.c (revision 2504075d)
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 	nlm_release_call(data);
234 }
235 
236 static const struct rpc_call_ops nlm4svc_callback_ops = {
237 	.rpc_call_done = nlm4svc_callback_exit,
238 	.rpc_release = nlm4svc_callback_release,
239 };
240 
241 /*
242  * `Async' versions of the above service routines. They aren't really,
243  * because we send the callback before the reply proper. I hope this
244  * doesn't break any clients.
245  */
246 static __be32 nlm4svc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
247 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
248 {
249 	struct nlm_host	*host;
250 	struct nlm_rqst	*call;
251 	__be32 stat;
252 
253 	host = nlmsvc_lookup_host(rqstp,
254 				  argp->lock.caller,
255 				  argp->lock.len);
256 	if (host == NULL)
257 		return rpc_system_err;
258 
259 	call = nlm_alloc_call(host);
260 	if (call == NULL)
261 		return rpc_system_err;
262 
263 	stat = func(rqstp, argp, &call->a_res);
264 	if (stat != 0) {
265 		nlm_release_call(call);
266 		return stat;
267 	}
268 
269 	call->a_flags = RPC_TASK_ASYNC;
270 	if (nlm_async_reply(call, proc, &nlm4svc_callback_ops) < 0)
271 		return rpc_system_err;
272 	return rpc_success;
273 }
274 
275 static __be32 nlm4svc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
276 					     void	     *resp)
277 {
278 	dprintk("lockd: TEST_MSG      called\n");
279 	return nlm4svc_callback(rqstp, NLMPROC_TEST_RES, argp, nlm4svc_proc_test);
280 }
281 
282 static __be32 nlm4svc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
283 					     void	     *resp)
284 {
285 	dprintk("lockd: LOCK_MSG      called\n");
286 	return nlm4svc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlm4svc_proc_lock);
287 }
288 
289 static __be32 nlm4svc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
290 					       void	       *resp)
291 {
292 	dprintk("lockd: CANCEL_MSG    called\n");
293 	return nlm4svc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlm4svc_proc_cancel);
294 }
295 
296 static __be32 nlm4svc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
297                                                void            *resp)
298 {
299 	dprintk("lockd: UNLOCK_MSG    called\n");
300 	return nlm4svc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlm4svc_proc_unlock);
301 }
302 
303 static __be32 nlm4svc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
304                                                 void            *resp)
305 {
306 	dprintk("lockd: GRANTED_MSG   called\n");
307 	return nlm4svc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlm4svc_proc_granted);
308 }
309 
310 /*
311  * SHARE: create a DOS share or alter existing share.
312  */
313 static __be32
314 nlm4svc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
315 				          struct nlm_res  *resp)
316 {
317 	struct nlm_host	*host;
318 	struct nlm_file	*file;
319 
320 	dprintk("lockd: SHARE         called\n");
321 
322 	resp->cookie = argp->cookie;
323 
324 	/* Don't accept new lock requests during grace period */
325 	if (locks_in_grace() && !argp->reclaim) {
326 		resp->status = nlm_lck_denied_grace_period;
327 		return rpc_success;
328 	}
329 
330 	/* Obtain client and file */
331 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
332 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
333 
334 	/* Now try to create the share */
335 	resp->status = nlmsvc_share_file(host, file, argp);
336 
337 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
338 	nlm_release_host(host);
339 	nlm_release_file(file);
340 	return rpc_success;
341 }
342 
343 /*
344  * UNSHARE: Release a DOS share.
345  */
346 static __be32
347 nlm4svc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
348 				            struct nlm_res  *resp)
349 {
350 	struct nlm_host	*host;
351 	struct nlm_file	*file;
352 
353 	dprintk("lockd: UNSHARE       called\n");
354 
355 	resp->cookie = argp->cookie;
356 
357 	/* Don't accept requests during grace period */
358 	if (locks_in_grace()) {
359 		resp->status = nlm_lck_denied_grace_period;
360 		return rpc_success;
361 	}
362 
363 	/* Obtain client and file */
364 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
365 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
366 
367 	/* Now try to lock the file */
368 	resp->status = nlmsvc_unshare_file(host, file, argp);
369 
370 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
371 	nlm_release_host(host);
372 	nlm_release_file(file);
373 	return rpc_success;
374 }
375 
376 /*
377  * NM_LOCK: Create an unmonitored lock
378  */
379 static __be32
380 nlm4svc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
381 				            struct nlm_res  *resp)
382 {
383 	dprintk("lockd: NM_LOCK       called\n");
384 
385 	argp->monitor = 0;		/* just clean the monitor flag */
386 	return nlm4svc_proc_lock(rqstp, argp, resp);
387 }
388 
389 /*
390  * FREE_ALL: Release all locks and shares held by client
391  */
392 static __be32
393 nlm4svc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
394 					     void            *resp)
395 {
396 	struct nlm_host	*host;
397 
398 	/* Obtain client */
399 	if (nlm4svc_retrieve_args(rqstp, argp, &host, NULL))
400 		return rpc_success;
401 
402 	nlmsvc_free_host_resources(host);
403 	nlm_release_host(host);
404 	return rpc_success;
405 }
406 
407 /*
408  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
409  */
410 static __be32
411 nlm4svc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
412 					      void	        *resp)
413 {
414 	dprintk("lockd: SM_NOTIFY     called\n");
415 
416 	if (!nlm_privileged_requester(rqstp)) {
417 		char buf[RPC_MAX_ADDRBUFLEN];
418 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
419 				svc_print_addr(rqstp, buf, sizeof(buf)));
420 		return rpc_system_err;
421 	}
422 
423 	nlm_host_rebooted(argp);
424 	return rpc_success;
425 }
426 
427 /*
428  * client sent a GRANTED_RES, let's remove the associated block
429  */
430 static __be32
431 nlm4svc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
432                                                 void            *resp)
433 {
434         if (!nlmsvc_ops)
435                 return rpc_success;
436 
437         dprintk("lockd: GRANTED_RES   called\n");
438 
439         nlmsvc_grant_reply(&argp->cookie, argp->status);
440         return rpc_success;
441 }
442 
443 
444 /*
445  * NLM Server procedures.
446  */
447 
448 #define nlm4svc_encode_norep	nlm4svc_encode_void
449 #define nlm4svc_decode_norep	nlm4svc_decode_void
450 #define nlm4svc_decode_testres	nlm4svc_decode_void
451 #define nlm4svc_decode_lockres	nlm4svc_decode_void
452 #define nlm4svc_decode_unlockres	nlm4svc_decode_void
453 #define nlm4svc_decode_cancelres	nlm4svc_decode_void
454 #define nlm4svc_decode_grantedres	nlm4svc_decode_void
455 
456 #define nlm4svc_proc_none	nlm4svc_proc_null
457 #define nlm4svc_proc_test_res	nlm4svc_proc_null
458 #define nlm4svc_proc_lock_res	nlm4svc_proc_null
459 #define nlm4svc_proc_cancel_res	nlm4svc_proc_null
460 #define nlm4svc_proc_unlock_res	nlm4svc_proc_null
461 
462 struct nlm_void			{ int dummy; };
463 
464 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
465  { .pc_func	= (svc_procfunc) nlm4svc_proc_##name,	\
466    .pc_decode	= (kxdrproc_t) nlm4svc_decode_##xargt,	\
467    .pc_encode	= (kxdrproc_t) nlm4svc_encode_##xrest,	\
468    .pc_release	= NULL,					\
469    .pc_argsize	= sizeof(struct nlm_##argt),		\
470    .pc_ressize	= sizeof(struct nlm_##rest),		\
471    .pc_xdrressize = respsize,				\
472  }
473 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
474 #define	No	(1+1024/4)				/* netobj */
475 #define	St	1					/* status */
476 #define	Rg	4					/* range (offset + length) */
477 struct svc_procedure		nlmsvc_procedures4[] = {
478   PROC(null,		void,		void,		void,	void, 1),
479   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
480   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
481   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
482   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
483   PROC(granted,		testargs,	res,		args,	res, Ck+St),
484   PROC(test_msg,	testargs,	norep,		args,	void, 1),
485   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
486   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
487   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
488   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
489   PROC(test_res,	testres,	norep,		res,	void, 1),
490   PROC(lock_res,	lockres,	norep,		res,	void, 1),
491   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
492   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
493   PROC(granted_res,	res,		norep,		res,	void, 1),
494   /* statd callback */
495   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
496   PROC(none,		void,		void,		void,	void, 0),
497   PROC(none,		void,		void,		void,	void, 0),
498   PROC(none,		void,		void,		void,	void, 0),
499   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
500   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
501   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
502   PROC(free_all,	notify,		void,		args,	void, 1),
503 
504 };
505