xref: /linux/fs/lockd/svc4proc.c (revision 1795cf48b322b4d19230a40dbe7181acedd34a94)
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 	int rc = rpc_success;
87 
88 	dprintk("lockd: TEST4        called\n");
89 	resp->cookie = argp->cookie;
90 
91 	/* Don't accept test requests during grace period */
92 	if (nlmsvc_grace_period) {
93 		resp->status = nlm_lck_denied_grace_period;
94 		return rc;
95 	}
96 
97 	/* Obtain client and file */
98 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
99 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
100 
101 	/* Now check for conflicting locks */
102 	resp->status = nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie);
103 	if (resp->status == nlm_drop_reply)
104 		rc = rpc_drop_reply;
105 	else
106 		dprintk("lockd: TEST4        status %d\n", ntohl(resp->status));
107 
108 	nlm_release_host(host);
109 	nlm_release_file(file);
110 	return rc;
111 }
112 
113 static __be32
114 nlm4svc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
115 				         struct nlm_res  *resp)
116 {
117 	struct nlm_host	*host;
118 	struct nlm_file	*file;
119 	int rc = rpc_success;
120 
121 	dprintk("lockd: LOCK          called\n");
122 
123 	resp->cookie = argp->cookie;
124 
125 	/* Don't accept new lock requests during grace period */
126 	if (nlmsvc_grace_period && !argp->reclaim) {
127 		resp->status = nlm_lck_denied_grace_period;
128 		return rc;
129 	}
130 
131 	/* Obtain client and file */
132 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
133 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
134 
135 #if 0
136 	/* If supplied state doesn't match current state, we assume it's
137 	 * an old request that time-warped somehow. Any error return would
138 	 * do in this case because it's irrelevant anyway.
139 	 *
140 	 * NB: We don't retrieve the remote host's state yet.
141 	 */
142 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
143 		resp->status = nlm_lck_denied_nolocks;
144 	} else
145 #endif
146 
147 	/* Now try to lock the file */
148 	resp->status = nlmsvc_lock(rqstp, file, host, &argp->lock,
149 					argp->block, &argp->cookie);
150 	if (resp->status == nlm_drop_reply)
151 		rc = rpc_drop_reply;
152 	else
153 		dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
154 
155 	nlm_release_host(host);
156 	nlm_release_file(file);
157 	return rc;
158 }
159 
160 static __be32
161 nlm4svc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
162 				           struct nlm_res  *resp)
163 {
164 	struct nlm_host	*host;
165 	struct nlm_file	*file;
166 
167 	dprintk("lockd: CANCEL        called\n");
168 
169 	resp->cookie = argp->cookie;
170 
171 	/* Don't accept requests during grace period */
172 	if (nlmsvc_grace_period) {
173 		resp->status = nlm_lck_denied_grace_period;
174 		return rpc_success;
175 	}
176 
177 	/* Obtain client and file */
178 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
179 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
180 
181 	/* Try to cancel request. */
182 	resp->status = nlmsvc_cancel_blocked(file, &argp->lock);
183 
184 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
185 	nlm_release_host(host);
186 	nlm_release_file(file);
187 	return rpc_success;
188 }
189 
190 /*
191  * UNLOCK: release a lock
192  */
193 static __be32
194 nlm4svc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
195 				           struct nlm_res  *resp)
196 {
197 	struct nlm_host	*host;
198 	struct nlm_file	*file;
199 
200 	dprintk("lockd: UNLOCK        called\n");
201 
202 	resp->cookie = argp->cookie;
203 
204 	/* Don't accept new lock requests during grace period */
205 	if (nlmsvc_grace_period) {
206 		resp->status = nlm_lck_denied_grace_period;
207 		return rpc_success;
208 	}
209 
210 	/* Obtain client and file */
211 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
212 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
213 
214 	/* Now try to remove the lock */
215 	resp->status = nlmsvc_unlock(file, &argp->lock);
216 
217 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
218 	nlm_release_host(host);
219 	nlm_release_file(file);
220 	return rpc_success;
221 }
222 
223 /*
224  * GRANTED: A server calls us to tell that a process' lock request
225  * was granted
226  */
227 static __be32
228 nlm4svc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
229 				            struct nlm_res  *resp)
230 {
231 	resp->cookie = argp->cookie;
232 
233 	dprintk("lockd: GRANTED       called\n");
234 	resp->status = nlmclnt_grant(svc_addr_in(rqstp), &argp->lock);
235 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
236 	return rpc_success;
237 }
238 
239 /*
240  * This is the generic lockd callback for async RPC calls
241  */
242 static void nlm4svc_callback_exit(struct rpc_task *task, void *data)
243 {
244 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
245 			-task->tk_status);
246 }
247 
248 static void nlm4svc_callback_release(void *data)
249 {
250 	lock_kernel();
251 	nlm_release_call(data);
252 	unlock_kernel();
253 }
254 
255 static const struct rpc_call_ops nlm4svc_callback_ops = {
256 	.rpc_call_done = nlm4svc_callback_exit,
257 	.rpc_release = nlm4svc_callback_release,
258 };
259 
260 /*
261  * `Async' versions of the above service routines. They aren't really,
262  * because we send the callback before the reply proper. I hope this
263  * doesn't break any clients.
264  */
265 static __be32 nlm4svc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
266 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
267 {
268 	struct nlm_host	*host;
269 	struct nlm_rqst	*call;
270 	__be32 stat;
271 
272 	host = nlmsvc_lookup_host(rqstp,
273 				  argp->lock.caller,
274 				  argp->lock.len);
275 	if (host == NULL)
276 		return rpc_system_err;
277 
278 	call = nlm_alloc_call(host);
279 	if (call == NULL)
280 		return rpc_system_err;
281 
282 	stat = func(rqstp, argp, &call->a_res);
283 	if (stat != 0) {
284 		nlm_release_call(call);
285 		return stat;
286 	}
287 
288 	call->a_flags = RPC_TASK_ASYNC;
289 	if (nlm_async_reply(call, proc, &nlm4svc_callback_ops) < 0)
290 		return rpc_system_err;
291 	return rpc_success;
292 }
293 
294 static __be32 nlm4svc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
295 					     void	     *resp)
296 {
297 	dprintk("lockd: TEST_MSG      called\n");
298 	return nlm4svc_callback(rqstp, NLMPROC_TEST_RES, argp, nlm4svc_proc_test);
299 }
300 
301 static __be32 nlm4svc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
302 					     void	     *resp)
303 {
304 	dprintk("lockd: LOCK_MSG      called\n");
305 	return nlm4svc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlm4svc_proc_lock);
306 }
307 
308 static __be32 nlm4svc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
309 					       void	       *resp)
310 {
311 	dprintk("lockd: CANCEL_MSG    called\n");
312 	return nlm4svc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlm4svc_proc_cancel);
313 }
314 
315 static __be32 nlm4svc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
316                                                void            *resp)
317 {
318 	dprintk("lockd: UNLOCK_MSG    called\n");
319 	return nlm4svc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlm4svc_proc_unlock);
320 }
321 
322 static __be32 nlm4svc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
323                                                 void            *resp)
324 {
325 	dprintk("lockd: GRANTED_MSG   called\n");
326 	return nlm4svc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlm4svc_proc_granted);
327 }
328 
329 /*
330  * SHARE: create a DOS share or alter existing share.
331  */
332 static __be32
333 nlm4svc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
334 				          struct nlm_res  *resp)
335 {
336 	struct nlm_host	*host;
337 	struct nlm_file	*file;
338 
339 	dprintk("lockd: SHARE         called\n");
340 
341 	resp->cookie = argp->cookie;
342 
343 	/* Don't accept new lock requests during grace period */
344 	if (nlmsvc_grace_period && !argp->reclaim) {
345 		resp->status = nlm_lck_denied_grace_period;
346 		return rpc_success;
347 	}
348 
349 	/* Obtain client and file */
350 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
351 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
352 
353 	/* Now try to create the share */
354 	resp->status = nlmsvc_share_file(host, file, argp);
355 
356 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
357 	nlm_release_host(host);
358 	nlm_release_file(file);
359 	return rpc_success;
360 }
361 
362 /*
363  * UNSHARE: Release a DOS share.
364  */
365 static __be32
366 nlm4svc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
367 				            struct nlm_res  *resp)
368 {
369 	struct nlm_host	*host;
370 	struct nlm_file	*file;
371 
372 	dprintk("lockd: UNSHARE       called\n");
373 
374 	resp->cookie = argp->cookie;
375 
376 	/* Don't accept requests during grace period */
377 	if (nlmsvc_grace_period) {
378 		resp->status = nlm_lck_denied_grace_period;
379 		return rpc_success;
380 	}
381 
382 	/* Obtain client and file */
383 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
384 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
385 
386 	/* Now try to lock the file */
387 	resp->status = nlmsvc_unshare_file(host, file, argp);
388 
389 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
390 	nlm_release_host(host);
391 	nlm_release_file(file);
392 	return rpc_success;
393 }
394 
395 /*
396  * NM_LOCK: Create an unmonitored lock
397  */
398 static __be32
399 nlm4svc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
400 				            struct nlm_res  *resp)
401 {
402 	dprintk("lockd: NM_LOCK       called\n");
403 
404 	argp->monitor = 0;		/* just clean the monitor flag */
405 	return nlm4svc_proc_lock(rqstp, argp, resp);
406 }
407 
408 /*
409  * FREE_ALL: Release all locks and shares held by client
410  */
411 static __be32
412 nlm4svc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
413 					     void            *resp)
414 {
415 	struct nlm_host	*host;
416 
417 	/* Obtain client */
418 	if (nlm4svc_retrieve_args(rqstp, argp, &host, NULL))
419 		return rpc_success;
420 
421 	nlmsvc_free_host_resources(host);
422 	nlm_release_host(host);
423 	return rpc_success;
424 }
425 
426 /*
427  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
428  */
429 static __be32
430 nlm4svc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
431 					      void	        *resp)
432 {
433 	struct sockaddr_in	saddr;
434 
435 	memcpy(&saddr, svc_addr_in(rqstp), sizeof(saddr));
436 
437 	dprintk("lockd: SM_NOTIFY     called\n");
438 	if (saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)
439 	 || ntohs(saddr.sin_port) >= 1024) {
440 		char buf[RPC_MAX_ADDRBUFLEN];
441 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
442 				svc_print_addr(rqstp, buf, sizeof(buf)));
443 		return rpc_system_err;
444 	}
445 
446 	/* Obtain the host pointer for this NFS server and try to
447 	 * reclaim all locks we hold on this server.
448 	 */
449 	memset(&saddr, 0, sizeof(saddr));
450 	saddr.sin_addr.s_addr = argp->addr;
451 	nlm_host_rebooted(&saddr, argp->mon, argp->len, argp->state);
452 
453 	return rpc_success;
454 }
455 
456 /*
457  * client sent a GRANTED_RES, let's remove the associated block
458  */
459 static __be32
460 nlm4svc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
461                                                 void            *resp)
462 {
463         if (!nlmsvc_ops)
464                 return rpc_success;
465 
466         dprintk("lockd: GRANTED_RES   called\n");
467 
468         nlmsvc_grant_reply(&argp->cookie, argp->status);
469         return rpc_success;
470 }
471 
472 
473 /*
474  * NLM Server procedures.
475  */
476 
477 #define nlm4svc_encode_norep	nlm4svc_encode_void
478 #define nlm4svc_decode_norep	nlm4svc_decode_void
479 #define nlm4svc_decode_testres	nlm4svc_decode_void
480 #define nlm4svc_decode_lockres	nlm4svc_decode_void
481 #define nlm4svc_decode_unlockres	nlm4svc_decode_void
482 #define nlm4svc_decode_cancelres	nlm4svc_decode_void
483 #define nlm4svc_decode_grantedres	nlm4svc_decode_void
484 
485 #define nlm4svc_proc_none	nlm4svc_proc_null
486 #define nlm4svc_proc_test_res	nlm4svc_proc_null
487 #define nlm4svc_proc_lock_res	nlm4svc_proc_null
488 #define nlm4svc_proc_cancel_res	nlm4svc_proc_null
489 #define nlm4svc_proc_unlock_res	nlm4svc_proc_null
490 
491 struct nlm_void			{ int dummy; };
492 
493 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
494  { .pc_func	= (svc_procfunc) nlm4svc_proc_##name,	\
495    .pc_decode	= (kxdrproc_t) nlm4svc_decode_##xargt,	\
496    .pc_encode	= (kxdrproc_t) nlm4svc_encode_##xrest,	\
497    .pc_release	= NULL,					\
498    .pc_argsize	= sizeof(struct nlm_##argt),		\
499    .pc_ressize	= sizeof(struct nlm_##rest),		\
500    .pc_xdrressize = respsize,				\
501  }
502 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
503 #define	No	(1+1024/4)				/* netobj */
504 #define	St	1					/* status */
505 #define	Rg	4					/* range (offset + length) */
506 struct svc_procedure		nlmsvc_procedures4[] = {
507   PROC(null,		void,		void,		void,	void, 1),
508   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
509   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
510   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
511   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
512   PROC(granted,		testargs,	res,		args,	res, Ck+St),
513   PROC(test_msg,	testargs,	norep,		args,	void, 1),
514   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
515   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
516   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
517   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
518   PROC(test_res,	testres,	norep,		res,	void, 1),
519   PROC(lock_res,	lockres,	norep,		res,	void, 1),
520   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
521   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
522   PROC(granted_res,	res,		norep,		res,	void, 1),
523   /* statd callback */
524   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
525   PROC(none,		void,		void,		void,	void, 0),
526   PROC(none,		void,		void,		void,	void, 0),
527   PROC(none,		void,		void,		void,	void, 0),
528   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
529   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
530   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
531   PROC(free_all,	notify,		void,		args,	void, 1),
532 
533 };
534