xref: /linux/fs/lockd/svc4proc.c (revision 367b8112fe2ea5c39a7bb4d263dcdd9b612fae18)
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 #include <linux/lockd/sm_inter.h>
20 
21 
22 #define NLMDBG_FACILITY		NLMDBG_CLIENT
23 
24 /*
25  * Obtain client and file from arguments
26  */
27 static __be32
28 nlm4svc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
29 			struct nlm_host **hostp, struct nlm_file **filp)
30 {
31 	struct nlm_host		*host = NULL;
32 	struct nlm_file		*file = NULL;
33 	struct nlm_lock		*lock = &argp->lock;
34 	__be32			error = 0;
35 
36 	/* nfsd callbacks must have been installed for this procedure */
37 	if (!nlmsvc_ops)
38 		return nlm_lck_denied_nolocks;
39 
40 	/* Obtain host handle */
41 	if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
42 	 || (argp->monitor && nsm_monitor(host) < 0))
43 		goto no_locks;
44 	*hostp = host;
45 
46 	/* Obtain file pointer. Not used by FREE_ALL call. */
47 	if (filp != NULL) {
48 		if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
49 			goto no_locks;
50 		*filp = file;
51 
52 		/* Set up the missing parts of the file_lock structure */
53 		lock->fl.fl_file  = file->f_file;
54 		lock->fl.fl_owner = (fl_owner_t) host;
55 		lock->fl.fl_lmops = &nlmsvc_lock_operations;
56 	}
57 
58 	return 0;
59 
60 no_locks:
61 	nlm_release_host(host);
62  	if (error)
63 		return error;
64 	return nlm_lck_denied_nolocks;
65 }
66 
67 /*
68  * NULL: Test for presence of service
69  */
70 static __be32
71 nlm4svc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
72 {
73 	dprintk("lockd: NULL          called\n");
74 	return rpc_success;
75 }
76 
77 /*
78  * TEST: Check for conflicting lock
79  */
80 static __be32
81 nlm4svc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
82 				         struct nlm_res  *resp)
83 {
84 	struct nlm_host	*host;
85 	struct nlm_file	*file;
86 	__be32 rc = rpc_success;
87 
88 	dprintk("lockd: TEST4        called\n");
89 	resp->cookie = argp->cookie;
90 
91 	/* Obtain client and file */
92 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
93 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
94 
95 	/* Now check for conflicting locks */
96 	resp->status = nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie);
97 	if (resp->status == nlm_drop_reply)
98 		rc = rpc_drop_reply;
99 	else
100 		dprintk("lockd: TEST4        status %d\n", ntohl(resp->status));
101 
102 	nlm_release_host(host);
103 	nlm_release_file(file);
104 	return rc;
105 }
106 
107 static __be32
108 nlm4svc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
109 				         struct nlm_res  *resp)
110 {
111 	struct nlm_host	*host;
112 	struct nlm_file	*file;
113 	__be32 rc = rpc_success;
114 
115 	dprintk("lockd: LOCK          called\n");
116 
117 	resp->cookie = argp->cookie;
118 
119 	/* Obtain client and file */
120 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
121 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
122 
123 #if 0
124 	/* If supplied state doesn't match current state, we assume it's
125 	 * an old request that time-warped somehow. Any error return would
126 	 * do in this case because it's irrelevant anyway.
127 	 *
128 	 * NB: We don't retrieve the remote host's state yet.
129 	 */
130 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
131 		resp->status = nlm_lck_denied_nolocks;
132 	} else
133 #endif
134 
135 	/* Now try to lock the file */
136 	resp->status = nlmsvc_lock(rqstp, file, host, &argp->lock,
137 					argp->block, &argp->cookie,
138 					argp->reclaim);
139 	if (resp->status == nlm_drop_reply)
140 		rc = rpc_drop_reply;
141 	else
142 		dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
143 
144 	nlm_release_host(host);
145 	nlm_release_file(file);
146 	return rc;
147 }
148 
149 static __be32
150 nlm4svc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
151 				           struct nlm_res  *resp)
152 {
153 	struct nlm_host	*host;
154 	struct nlm_file	*file;
155 
156 	dprintk("lockd: CANCEL        called\n");
157 
158 	resp->cookie = argp->cookie;
159 
160 	/* Don't accept requests during grace period */
161 	if (locks_in_grace()) {
162 		resp->status = nlm_lck_denied_grace_period;
163 		return rpc_success;
164 	}
165 
166 	/* Obtain client and file */
167 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
168 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
169 
170 	/* Try to cancel request. */
171 	resp->status = nlmsvc_cancel_blocked(file, &argp->lock);
172 
173 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
174 	nlm_release_host(host);
175 	nlm_release_file(file);
176 	return rpc_success;
177 }
178 
179 /*
180  * UNLOCK: release a lock
181  */
182 static __be32
183 nlm4svc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
184 				           struct nlm_res  *resp)
185 {
186 	struct nlm_host	*host;
187 	struct nlm_file	*file;
188 
189 	dprintk("lockd: UNLOCK        called\n");
190 
191 	resp->cookie = argp->cookie;
192 
193 	/* Don't accept new lock requests during grace period */
194 	if (locks_in_grace()) {
195 		resp->status = nlm_lck_denied_grace_period;
196 		return rpc_success;
197 	}
198 
199 	/* Obtain client and file */
200 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
201 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
202 
203 	/* Now try to remove the lock */
204 	resp->status = nlmsvc_unlock(file, &argp->lock);
205 
206 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
207 	nlm_release_host(host);
208 	nlm_release_file(file);
209 	return rpc_success;
210 }
211 
212 /*
213  * GRANTED: A server calls us to tell that a process' lock request
214  * was granted
215  */
216 static __be32
217 nlm4svc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
218 				            struct nlm_res  *resp)
219 {
220 	resp->cookie = argp->cookie;
221 
222 	dprintk("lockd: GRANTED       called\n");
223 	resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
224 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
225 	return rpc_success;
226 }
227 
228 /*
229  * This is the generic lockd callback for async RPC calls
230  */
231 static void nlm4svc_callback_exit(struct rpc_task *task, void *data)
232 {
233 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
234 			-task->tk_status);
235 }
236 
237 static void nlm4svc_callback_release(void *data)
238 {
239 	lock_kernel();
240 	nlm_release_call(data);
241 	unlock_kernel();
242 }
243 
244 static const struct rpc_call_ops nlm4svc_callback_ops = {
245 	.rpc_call_done = nlm4svc_callback_exit,
246 	.rpc_release = nlm4svc_callback_release,
247 };
248 
249 /*
250  * `Async' versions of the above service routines. They aren't really,
251  * because we send the callback before the reply proper. I hope this
252  * doesn't break any clients.
253  */
254 static __be32 nlm4svc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
255 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
256 {
257 	struct nlm_host	*host;
258 	struct nlm_rqst	*call;
259 	__be32 stat;
260 
261 	host = nlmsvc_lookup_host(rqstp,
262 				  argp->lock.caller,
263 				  argp->lock.len);
264 	if (host == NULL)
265 		return rpc_system_err;
266 
267 	call = nlm_alloc_call(host);
268 	if (call == NULL)
269 		return rpc_system_err;
270 
271 	stat = func(rqstp, argp, &call->a_res);
272 	if (stat != 0) {
273 		nlm_release_call(call);
274 		return stat;
275 	}
276 
277 	call->a_flags = RPC_TASK_ASYNC;
278 	if (nlm_async_reply(call, proc, &nlm4svc_callback_ops) < 0)
279 		return rpc_system_err;
280 	return rpc_success;
281 }
282 
283 static __be32 nlm4svc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
284 					     void	     *resp)
285 {
286 	dprintk("lockd: TEST_MSG      called\n");
287 	return nlm4svc_callback(rqstp, NLMPROC_TEST_RES, argp, nlm4svc_proc_test);
288 }
289 
290 static __be32 nlm4svc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
291 					     void	     *resp)
292 {
293 	dprintk("lockd: LOCK_MSG      called\n");
294 	return nlm4svc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlm4svc_proc_lock);
295 }
296 
297 static __be32 nlm4svc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
298 					       void	       *resp)
299 {
300 	dprintk("lockd: CANCEL_MSG    called\n");
301 	return nlm4svc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlm4svc_proc_cancel);
302 }
303 
304 static __be32 nlm4svc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
305                                                void            *resp)
306 {
307 	dprintk("lockd: UNLOCK_MSG    called\n");
308 	return nlm4svc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlm4svc_proc_unlock);
309 }
310 
311 static __be32 nlm4svc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
312                                                 void            *resp)
313 {
314 	dprintk("lockd: GRANTED_MSG   called\n");
315 	return nlm4svc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlm4svc_proc_granted);
316 }
317 
318 /*
319  * SHARE: create a DOS share or alter existing share.
320  */
321 static __be32
322 nlm4svc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
323 				          struct nlm_res  *resp)
324 {
325 	struct nlm_host	*host;
326 	struct nlm_file	*file;
327 
328 	dprintk("lockd: SHARE         called\n");
329 
330 	resp->cookie = argp->cookie;
331 
332 	/* Don't accept new lock requests during grace period */
333 	if (locks_in_grace() && !argp->reclaim) {
334 		resp->status = nlm_lck_denied_grace_period;
335 		return rpc_success;
336 	}
337 
338 	/* Obtain client and file */
339 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
340 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
341 
342 	/* Now try to create the share */
343 	resp->status = nlmsvc_share_file(host, file, argp);
344 
345 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
346 	nlm_release_host(host);
347 	nlm_release_file(file);
348 	return rpc_success;
349 }
350 
351 /*
352  * UNSHARE: Release a DOS share.
353  */
354 static __be32
355 nlm4svc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
356 				            struct nlm_res  *resp)
357 {
358 	struct nlm_host	*host;
359 	struct nlm_file	*file;
360 
361 	dprintk("lockd: UNSHARE       called\n");
362 
363 	resp->cookie = argp->cookie;
364 
365 	/* Don't accept requests during grace period */
366 	if (locks_in_grace()) {
367 		resp->status = nlm_lck_denied_grace_period;
368 		return rpc_success;
369 	}
370 
371 	/* Obtain client and file */
372 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
373 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
374 
375 	/* Now try to lock the file */
376 	resp->status = nlmsvc_unshare_file(host, file, argp);
377 
378 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
379 	nlm_release_host(host);
380 	nlm_release_file(file);
381 	return rpc_success;
382 }
383 
384 /*
385  * NM_LOCK: Create an unmonitored lock
386  */
387 static __be32
388 nlm4svc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
389 				            struct nlm_res  *resp)
390 {
391 	dprintk("lockd: NM_LOCK       called\n");
392 
393 	argp->monitor = 0;		/* just clean the monitor flag */
394 	return nlm4svc_proc_lock(rqstp, argp, resp);
395 }
396 
397 /*
398  * FREE_ALL: Release all locks and shares held by client
399  */
400 static __be32
401 nlm4svc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
402 					     void            *resp)
403 {
404 	struct nlm_host	*host;
405 
406 	/* Obtain client */
407 	if (nlm4svc_retrieve_args(rqstp, argp, &host, NULL))
408 		return rpc_success;
409 
410 	nlmsvc_free_host_resources(host);
411 	nlm_release_host(host);
412 	return rpc_success;
413 }
414 
415 /*
416  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
417  */
418 static __be32
419 nlm4svc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
420 					      void	        *resp)
421 {
422 	struct sockaddr_in	saddr;
423 
424 	dprintk("lockd: SM_NOTIFY     called\n");
425 
426 	if (!nlm_privileged_requester(rqstp)) {
427 		char buf[RPC_MAX_ADDRBUFLEN];
428 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
429 				svc_print_addr(rqstp, buf, sizeof(buf)));
430 		return rpc_system_err;
431 	}
432 
433 	/* Obtain the host pointer for this NFS server and try to
434 	 * reclaim all locks we hold on this server.
435 	 */
436 	memset(&saddr, 0, sizeof(saddr));
437 	saddr.sin_family = AF_INET;
438 	saddr.sin_addr.s_addr = argp->addr;
439 	nlm_host_rebooted(&saddr, argp->mon, argp->len, argp->state);
440 
441 	return rpc_success;
442 }
443 
444 /*
445  * client sent a GRANTED_RES, let's remove the associated block
446  */
447 static __be32
448 nlm4svc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
449                                                 void            *resp)
450 {
451         if (!nlmsvc_ops)
452                 return rpc_success;
453 
454         dprintk("lockd: GRANTED_RES   called\n");
455 
456         nlmsvc_grant_reply(&argp->cookie, argp->status);
457         return rpc_success;
458 }
459 
460 
461 /*
462  * NLM Server procedures.
463  */
464 
465 #define nlm4svc_encode_norep	nlm4svc_encode_void
466 #define nlm4svc_decode_norep	nlm4svc_decode_void
467 #define nlm4svc_decode_testres	nlm4svc_decode_void
468 #define nlm4svc_decode_lockres	nlm4svc_decode_void
469 #define nlm4svc_decode_unlockres	nlm4svc_decode_void
470 #define nlm4svc_decode_cancelres	nlm4svc_decode_void
471 #define nlm4svc_decode_grantedres	nlm4svc_decode_void
472 
473 #define nlm4svc_proc_none	nlm4svc_proc_null
474 #define nlm4svc_proc_test_res	nlm4svc_proc_null
475 #define nlm4svc_proc_lock_res	nlm4svc_proc_null
476 #define nlm4svc_proc_cancel_res	nlm4svc_proc_null
477 #define nlm4svc_proc_unlock_res	nlm4svc_proc_null
478 
479 struct nlm_void			{ int dummy; };
480 
481 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
482  { .pc_func	= (svc_procfunc) nlm4svc_proc_##name,	\
483    .pc_decode	= (kxdrproc_t) nlm4svc_decode_##xargt,	\
484    .pc_encode	= (kxdrproc_t) nlm4svc_encode_##xrest,	\
485    .pc_release	= NULL,					\
486    .pc_argsize	= sizeof(struct nlm_##argt),		\
487    .pc_ressize	= sizeof(struct nlm_##rest),		\
488    .pc_xdrressize = respsize,				\
489  }
490 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
491 #define	No	(1+1024/4)				/* netobj */
492 #define	St	1					/* status */
493 #define	Rg	4					/* range (offset + length) */
494 struct svc_procedure		nlmsvc_procedures4[] = {
495   PROC(null,		void,		void,		void,	void, 1),
496   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
497   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
498   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
499   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
500   PROC(granted,		testargs,	res,		args,	res, Ck+St),
501   PROC(test_msg,	testargs,	norep,		args,	void, 1),
502   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
503   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
504   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
505   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
506   PROC(test_res,	testres,	norep,		res,	void, 1),
507   PROC(lock_res,	lockres,	norep,		res,	void, 1),
508   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
509   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
510   PROC(granted_res,	res,		norep,		res,	void, 1),
511   /* statd callback */
512   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
513   PROC(none,		void,		void,		void,	void, 0),
514   PROC(none,		void,		void,		void,	void, 0),
515   PROC(none,		void,		void,		void,	void, 0),
516   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
517   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
518   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
519   PROC(free_all,	notify,		void,		args,	void, 1),
520 
521 };
522