xref: /linux/fs/lockd/svc4proc.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
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/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 
20 #define NLMDBG_FACILITY		NLMDBG_CLIENT
21 
22 /*
23  * Obtain client and file from arguments
24  */
25 static __be32
26 nlm4svc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
27 			struct nlm_host **hostp, struct nlm_file **filp)
28 {
29 	struct nlm_host		*host = NULL;
30 	struct nlm_file		*file = NULL;
31 	struct nlm_lock		*lock = &argp->lock;
32 	__be32			error = 0;
33 
34 	/* nfsd callbacks must have been installed for this procedure */
35 	if (!nlmsvc_ops)
36 		return nlm_lck_denied_nolocks;
37 
38 	/* Obtain host handle */
39 	if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
40 	 || (argp->monitor && nsm_monitor(host) < 0))
41 		goto no_locks;
42 	*hostp = host;
43 
44 	/* Obtain file pointer. Not used by FREE_ALL call. */
45 	if (filp != NULL) {
46 		if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
47 			goto no_locks;
48 		*filp = file;
49 
50 		/* Set up the missing parts of the file_lock structure */
51 		lock->fl.fl_file  = file->f_file;
52 		lock->fl.fl_owner = (fl_owner_t) host;
53 		lock->fl.fl_lmops = &nlmsvc_lock_operations;
54 	}
55 
56 	return 0;
57 
58 no_locks:
59 	nlm_release_host(host);
60  	if (error)
61 		return error;
62 	return nlm_lck_denied_nolocks;
63 }
64 
65 /*
66  * NULL: Test for presence of service
67  */
68 static __be32
69 nlm4svc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
70 {
71 	dprintk("lockd: NULL          called\n");
72 	return rpc_success;
73 }
74 
75 /*
76  * TEST: Check for conflicting lock
77  */
78 static __be32
79 nlm4svc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
80 				         struct nlm_res  *resp)
81 {
82 	struct nlm_host	*host;
83 	struct nlm_file	*file;
84 	__be32 rc = rpc_success;
85 
86 	dprintk("lockd: TEST4        called\n");
87 	resp->cookie = argp->cookie;
88 
89 	/* Obtain client and file */
90 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
91 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
92 
93 	/* Now check for conflicting locks */
94 	resp->status = nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie);
95 	if (resp->status == nlm_drop_reply)
96 		rc = rpc_drop_reply;
97 	else
98 		dprintk("lockd: TEST4        status %d\n", ntohl(resp->status));
99 
100 	nlm_release_host(host);
101 	nlm_release_file(file);
102 	return rc;
103 }
104 
105 static __be32
106 nlm4svc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
107 				         struct nlm_res  *resp)
108 {
109 	struct nlm_host	*host;
110 	struct nlm_file	*file;
111 	__be32 rc = rpc_success;
112 
113 	dprintk("lockd: LOCK          called\n");
114 
115 	resp->cookie = argp->cookie;
116 
117 	/* Obtain client and file */
118 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
119 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
120 
121 #if 0
122 	/* If supplied state doesn't match current state, we assume it's
123 	 * an old request that time-warped somehow. Any error return would
124 	 * do in this case because it's irrelevant anyway.
125 	 *
126 	 * NB: We don't retrieve the remote host's state yet.
127 	 */
128 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
129 		resp->status = nlm_lck_denied_nolocks;
130 	} else
131 #endif
132 
133 	/* Now try to lock the file */
134 	resp->status = nlmsvc_lock(rqstp, file, host, &argp->lock,
135 					argp->block, &argp->cookie,
136 					argp->reclaim);
137 	if (resp->status == nlm_drop_reply)
138 		rc = rpc_drop_reply;
139 	else
140 		dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
141 
142 	nlm_release_host(host);
143 	nlm_release_file(file);
144 	return rc;
145 }
146 
147 static __be32
148 nlm4svc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
149 				           struct nlm_res  *resp)
150 {
151 	struct nlm_host	*host;
152 	struct nlm_file	*file;
153 
154 	dprintk("lockd: CANCEL        called\n");
155 
156 	resp->cookie = argp->cookie;
157 
158 	/* Don't accept requests during grace period */
159 	if (locks_in_grace()) {
160 		resp->status = nlm_lck_denied_grace_period;
161 		return rpc_success;
162 	}
163 
164 	/* Obtain client and file */
165 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
166 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
167 
168 	/* Try to cancel request. */
169 	resp->status = nlmsvc_cancel_blocked(file, &argp->lock);
170 
171 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
172 	nlm_release_host(host);
173 	nlm_release_file(file);
174 	return rpc_success;
175 }
176 
177 /*
178  * UNLOCK: release a lock
179  */
180 static __be32
181 nlm4svc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
182 				           struct nlm_res  *resp)
183 {
184 	struct nlm_host	*host;
185 	struct nlm_file	*file;
186 
187 	dprintk("lockd: UNLOCK        called\n");
188 
189 	resp->cookie = argp->cookie;
190 
191 	/* Don't accept new lock requests during grace period */
192 	if (locks_in_grace()) {
193 		resp->status = nlm_lck_denied_grace_period;
194 		return rpc_success;
195 	}
196 
197 	/* Obtain client and file */
198 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
199 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
200 
201 	/* Now try to remove the lock */
202 	resp->status = nlmsvc_unlock(file, &argp->lock);
203 
204 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
205 	nlm_release_host(host);
206 	nlm_release_file(file);
207 	return rpc_success;
208 }
209 
210 /*
211  * GRANTED: A server calls us to tell that a process' lock request
212  * was granted
213  */
214 static __be32
215 nlm4svc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
216 				            struct nlm_res  *resp)
217 {
218 	resp->cookie = argp->cookie;
219 
220 	dprintk("lockd: GRANTED       called\n");
221 	resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
222 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
223 	return rpc_success;
224 }
225 
226 /*
227  * This is the generic lockd callback for async RPC calls
228  */
229 static void nlm4svc_callback_exit(struct rpc_task *task, void *data)
230 {
231 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
232 			-task->tk_status);
233 }
234 
235 static void nlm4svc_callback_release(void *data)
236 {
237 	lock_kernel();
238 	nlm_release_call(data);
239 	unlock_kernel();
240 }
241 
242 static const struct rpc_call_ops nlm4svc_callback_ops = {
243 	.rpc_call_done = nlm4svc_callback_exit,
244 	.rpc_release = nlm4svc_callback_release,
245 };
246 
247 /*
248  * `Async' versions of the above service routines. They aren't really,
249  * because we send the callback before the reply proper. I hope this
250  * doesn't break any clients.
251  */
252 static __be32 nlm4svc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
253 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
254 {
255 	struct nlm_host	*host;
256 	struct nlm_rqst	*call;
257 	__be32 stat;
258 
259 	host = nlmsvc_lookup_host(rqstp,
260 				  argp->lock.caller,
261 				  argp->lock.len);
262 	if (host == NULL)
263 		return rpc_system_err;
264 
265 	call = nlm_alloc_call(host);
266 	if (call == NULL)
267 		return rpc_system_err;
268 
269 	stat = func(rqstp, argp, &call->a_res);
270 	if (stat != 0) {
271 		nlm_release_call(call);
272 		return stat;
273 	}
274 
275 	call->a_flags = RPC_TASK_ASYNC;
276 	if (nlm_async_reply(call, proc, &nlm4svc_callback_ops) < 0)
277 		return rpc_system_err;
278 	return rpc_success;
279 }
280 
281 static __be32 nlm4svc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
282 					     void	     *resp)
283 {
284 	dprintk("lockd: TEST_MSG      called\n");
285 	return nlm4svc_callback(rqstp, NLMPROC_TEST_RES, argp, nlm4svc_proc_test);
286 }
287 
288 static __be32 nlm4svc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
289 					     void	     *resp)
290 {
291 	dprintk("lockd: LOCK_MSG      called\n");
292 	return nlm4svc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlm4svc_proc_lock);
293 }
294 
295 static __be32 nlm4svc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
296 					       void	       *resp)
297 {
298 	dprintk("lockd: CANCEL_MSG    called\n");
299 	return nlm4svc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlm4svc_proc_cancel);
300 }
301 
302 static __be32 nlm4svc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
303                                                void            *resp)
304 {
305 	dprintk("lockd: UNLOCK_MSG    called\n");
306 	return nlm4svc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlm4svc_proc_unlock);
307 }
308 
309 static __be32 nlm4svc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
310                                                 void            *resp)
311 {
312 	dprintk("lockd: GRANTED_MSG   called\n");
313 	return nlm4svc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlm4svc_proc_granted);
314 }
315 
316 /*
317  * SHARE: create a DOS share or alter existing share.
318  */
319 static __be32
320 nlm4svc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
321 				          struct nlm_res  *resp)
322 {
323 	struct nlm_host	*host;
324 	struct nlm_file	*file;
325 
326 	dprintk("lockd: SHARE         called\n");
327 
328 	resp->cookie = argp->cookie;
329 
330 	/* Don't accept new lock requests during grace period */
331 	if (locks_in_grace() && !argp->reclaim) {
332 		resp->status = nlm_lck_denied_grace_period;
333 		return rpc_success;
334 	}
335 
336 	/* Obtain client and file */
337 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
338 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
339 
340 	/* Now try to create the share */
341 	resp->status = nlmsvc_share_file(host, file, argp);
342 
343 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
344 	nlm_release_host(host);
345 	nlm_release_file(file);
346 	return rpc_success;
347 }
348 
349 /*
350  * UNSHARE: Release a DOS share.
351  */
352 static __be32
353 nlm4svc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
354 				            struct nlm_res  *resp)
355 {
356 	struct nlm_host	*host;
357 	struct nlm_file	*file;
358 
359 	dprintk("lockd: UNSHARE       called\n");
360 
361 	resp->cookie = argp->cookie;
362 
363 	/* Don't accept requests during grace period */
364 	if (locks_in_grace()) {
365 		resp->status = nlm_lck_denied_grace_period;
366 		return rpc_success;
367 	}
368 
369 	/* Obtain client and file */
370 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
371 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
372 
373 	/* Now try to lock the file */
374 	resp->status = nlmsvc_unshare_file(host, file, argp);
375 
376 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
377 	nlm_release_host(host);
378 	nlm_release_file(file);
379 	return rpc_success;
380 }
381 
382 /*
383  * NM_LOCK: Create an unmonitored lock
384  */
385 static __be32
386 nlm4svc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
387 				            struct nlm_res  *resp)
388 {
389 	dprintk("lockd: NM_LOCK       called\n");
390 
391 	argp->monitor = 0;		/* just clean the monitor flag */
392 	return nlm4svc_proc_lock(rqstp, argp, resp);
393 }
394 
395 /*
396  * FREE_ALL: Release all locks and shares held by client
397  */
398 static __be32
399 nlm4svc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
400 					     void            *resp)
401 {
402 	struct nlm_host	*host;
403 
404 	/* Obtain client */
405 	if (nlm4svc_retrieve_args(rqstp, argp, &host, NULL))
406 		return rpc_success;
407 
408 	nlmsvc_free_host_resources(host);
409 	nlm_release_host(host);
410 	return rpc_success;
411 }
412 
413 /*
414  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
415  */
416 static __be32
417 nlm4svc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
418 					      void	        *resp)
419 {
420 	dprintk("lockd: SM_NOTIFY     called\n");
421 
422 	if (!nlm_privileged_requester(rqstp)) {
423 		char buf[RPC_MAX_ADDRBUFLEN];
424 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
425 				svc_print_addr(rqstp, buf, sizeof(buf)));
426 		return rpc_system_err;
427 	}
428 
429 	nlm_host_rebooted(argp);
430 	return rpc_success;
431 }
432 
433 /*
434  * client sent a GRANTED_RES, let's remove the associated block
435  */
436 static __be32
437 nlm4svc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
438                                                 void            *resp)
439 {
440         if (!nlmsvc_ops)
441                 return rpc_success;
442 
443         dprintk("lockd: GRANTED_RES   called\n");
444 
445         nlmsvc_grant_reply(&argp->cookie, argp->status);
446         return rpc_success;
447 }
448 
449 
450 /*
451  * NLM Server procedures.
452  */
453 
454 #define nlm4svc_encode_norep	nlm4svc_encode_void
455 #define nlm4svc_decode_norep	nlm4svc_decode_void
456 #define nlm4svc_decode_testres	nlm4svc_decode_void
457 #define nlm4svc_decode_lockres	nlm4svc_decode_void
458 #define nlm4svc_decode_unlockres	nlm4svc_decode_void
459 #define nlm4svc_decode_cancelres	nlm4svc_decode_void
460 #define nlm4svc_decode_grantedres	nlm4svc_decode_void
461 
462 #define nlm4svc_proc_none	nlm4svc_proc_null
463 #define nlm4svc_proc_test_res	nlm4svc_proc_null
464 #define nlm4svc_proc_lock_res	nlm4svc_proc_null
465 #define nlm4svc_proc_cancel_res	nlm4svc_proc_null
466 #define nlm4svc_proc_unlock_res	nlm4svc_proc_null
467 
468 struct nlm_void			{ int dummy; };
469 
470 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
471  { .pc_func	= (svc_procfunc) nlm4svc_proc_##name,	\
472    .pc_decode	= (kxdrproc_t) nlm4svc_decode_##xargt,	\
473    .pc_encode	= (kxdrproc_t) nlm4svc_encode_##xrest,	\
474    .pc_release	= NULL,					\
475    .pc_argsize	= sizeof(struct nlm_##argt),		\
476    .pc_ressize	= sizeof(struct nlm_##rest),		\
477    .pc_xdrressize = respsize,				\
478  }
479 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
480 #define	No	(1+1024/4)				/* netobj */
481 #define	St	1					/* status */
482 #define	Rg	4					/* range (offset + length) */
483 struct svc_procedure		nlmsvc_procedures4[] = {
484   PROC(null,		void,		void,		void,	void, 1),
485   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
486   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
487   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
488   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
489   PROC(granted,		testargs,	res,		args,	res, Ck+St),
490   PROC(test_msg,	testargs,	norep,		args,	void, 1),
491   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
492   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
493   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
494   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
495   PROC(test_res,	testres,	norep,		res,	void, 1),
496   PROC(lock_res,	lockres,	norep,		res,	void, 1),
497   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
498   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
499   PROC(granted_res,	res,		norep,		res,	void, 1),
500   /* statd callback */
501   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
502   PROC(none,		void,		void,		void,	void, 0),
503   PROC(none,		void,		void,		void,	void, 0),
504   PROC(none,		void,		void,		void,	void, 0),
505   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
506   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
507   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
508   PROC(free_all,	notify,		void,		args,	void, 1),
509 
510 };
511