xref: /linux/fs/lockd/svc4proc.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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 	if (host)
62 		nlm_release_host(host);
63  	if (error)
64 		return error;
65 	return nlm_lck_denied_nolocks;
66 }
67 
68 /*
69  * NULL: Test for presence of service
70  */
71 static __be32
72 nlm4svc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
73 {
74 	dprintk("lockd: NULL          called\n");
75 	return rpc_success;
76 }
77 
78 /*
79  * TEST: Check for conflicting lock
80  */
81 static __be32
82 nlm4svc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
83 				         struct nlm_res  *resp)
84 {
85 	struct nlm_host	*host;
86 	struct nlm_file	*file;
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 rpc_success;
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(file, &argp->lock, &resp->lock);
103 
104 	dprintk("lockd: TEST4          status %d\n", ntohl(resp->status));
105 	nlm_release_host(host);
106 	nlm_release_file(file);
107 	return rpc_success;
108 }
109 
110 static __be32
111 nlm4svc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
112 				         struct nlm_res  *resp)
113 {
114 	struct nlm_host	*host;
115 	struct nlm_file	*file;
116 
117 	dprintk("lockd: LOCK          called\n");
118 
119 	resp->cookie = argp->cookie;
120 
121 	/* Don't accept new lock requests during grace period */
122 	if (nlmsvc_grace_period && !argp->reclaim) {
123 		resp->status = nlm_lck_denied_grace_period;
124 		return rpc_success;
125 	}
126 
127 	/* Obtain client and file */
128 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
129 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
130 
131 #if 0
132 	/* If supplied state doesn't match current state, we assume it's
133 	 * an old request that time-warped somehow. Any error return would
134 	 * do in this case because it's irrelevant anyway.
135 	 *
136 	 * NB: We don't retrieve the remote host's state yet.
137 	 */
138 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
139 		resp->status = nlm_lck_denied_nolocks;
140 	} else
141 #endif
142 
143 	/* Now try to lock the file */
144 	resp->status = nlmsvc_lock(rqstp, file, &argp->lock,
145 					argp->block, &argp->cookie);
146 
147 	dprintk("lockd: LOCK          status %d\n", ntohl(resp->status));
148 	nlm_release_host(host);
149 	nlm_release_file(file);
150 	return rpc_success;
151 }
152 
153 static __be32
154 nlm4svc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
155 				           struct nlm_res  *resp)
156 {
157 	struct nlm_host	*host;
158 	struct nlm_file	*file;
159 
160 	dprintk("lockd: CANCEL        called\n");
161 
162 	resp->cookie = argp->cookie;
163 
164 	/* Don't accept requests during grace period */
165 	if (nlmsvc_grace_period) {
166 		resp->status = nlm_lck_denied_grace_period;
167 		return rpc_success;
168 	}
169 
170 	/* Obtain client and file */
171 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
172 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
173 
174 	/* Try to cancel request. */
175 	resp->status = nlmsvc_cancel_blocked(file, &argp->lock);
176 
177 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
178 	nlm_release_host(host);
179 	nlm_release_file(file);
180 	return rpc_success;
181 }
182 
183 /*
184  * UNLOCK: release a lock
185  */
186 static __be32
187 nlm4svc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
188 				           struct nlm_res  *resp)
189 {
190 	struct nlm_host	*host;
191 	struct nlm_file	*file;
192 
193 	dprintk("lockd: UNLOCK        called\n");
194 
195 	resp->cookie = argp->cookie;
196 
197 	/* Don't accept new lock requests during grace period */
198 	if (nlmsvc_grace_period) {
199 		resp->status = nlm_lck_denied_grace_period;
200 		return rpc_success;
201 	}
202 
203 	/* Obtain client and file */
204 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
205 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
206 
207 	/* Now try to remove the lock */
208 	resp->status = nlmsvc_unlock(file, &argp->lock);
209 
210 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
211 	nlm_release_host(host);
212 	nlm_release_file(file);
213 	return rpc_success;
214 }
215 
216 /*
217  * GRANTED: A server calls us to tell that a process' lock request
218  * was granted
219  */
220 static __be32
221 nlm4svc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
222 				            struct nlm_res  *resp)
223 {
224 	resp->cookie = argp->cookie;
225 
226 	dprintk("lockd: GRANTED       called\n");
227 	resp->status = nlmclnt_grant(svc_addr_in(rqstp), &argp->lock);
228 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
229 	return rpc_success;
230 }
231 
232 /*
233  * This is the generic lockd callback for async RPC calls
234  */
235 static void nlm4svc_callback_exit(struct rpc_task *task, void *data)
236 {
237 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
238 			-task->tk_status);
239 }
240 
241 static void nlm4svc_callback_release(void *data)
242 {
243 	nlm_release_call(data);
244 }
245 
246 static const struct rpc_call_ops nlm4svc_callback_ops = {
247 	.rpc_call_done = nlm4svc_callback_exit,
248 	.rpc_release = nlm4svc_callback_release,
249 };
250 
251 /*
252  * `Async' versions of the above service routines. They aren't really,
253  * because we send the callback before the reply proper. I hope this
254  * doesn't break any clients.
255  */
256 static __be32 nlm4svc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
257 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
258 {
259 	struct nlm_host	*host;
260 	struct nlm_rqst	*call;
261 	__be32 stat;
262 
263 	host = nlmsvc_lookup_host(rqstp,
264 				  argp->lock.caller,
265 				  argp->lock.len);
266 	if (host == NULL)
267 		return rpc_system_err;
268 
269 	call = nlm_alloc_call(host);
270 	if (call == NULL)
271 		return rpc_system_err;
272 
273 	stat = func(rqstp, argp, &call->a_res);
274 	if (stat != 0) {
275 		nlm_release_call(call);
276 		return stat;
277 	}
278 
279 	call->a_flags = RPC_TASK_ASYNC;
280 	if (nlm_async_reply(call, proc, &nlm4svc_callback_ops) < 0)
281 		return rpc_system_err;
282 	return rpc_success;
283 }
284 
285 static __be32 nlm4svc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
286 					     void	     *resp)
287 {
288 	dprintk("lockd: TEST_MSG      called\n");
289 	return nlm4svc_callback(rqstp, NLMPROC_TEST_RES, argp, nlm4svc_proc_test);
290 }
291 
292 static __be32 nlm4svc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
293 					     void	     *resp)
294 {
295 	dprintk("lockd: LOCK_MSG      called\n");
296 	return nlm4svc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlm4svc_proc_lock);
297 }
298 
299 static __be32 nlm4svc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
300 					       void	       *resp)
301 {
302 	dprintk("lockd: CANCEL_MSG    called\n");
303 	return nlm4svc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlm4svc_proc_cancel);
304 }
305 
306 static __be32 nlm4svc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
307                                                void            *resp)
308 {
309 	dprintk("lockd: UNLOCK_MSG    called\n");
310 	return nlm4svc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlm4svc_proc_unlock);
311 }
312 
313 static __be32 nlm4svc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
314                                                 void            *resp)
315 {
316 	dprintk("lockd: GRANTED_MSG   called\n");
317 	return nlm4svc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlm4svc_proc_granted);
318 }
319 
320 /*
321  * SHARE: create a DOS share or alter existing share.
322  */
323 static __be32
324 nlm4svc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
325 				          struct nlm_res  *resp)
326 {
327 	struct nlm_host	*host;
328 	struct nlm_file	*file;
329 
330 	dprintk("lockd: SHARE         called\n");
331 
332 	resp->cookie = argp->cookie;
333 
334 	/* Don't accept new lock requests during grace period */
335 	if (nlmsvc_grace_period && !argp->reclaim) {
336 		resp->status = nlm_lck_denied_grace_period;
337 		return rpc_success;
338 	}
339 
340 	/* Obtain client and file */
341 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
342 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
343 
344 	/* Now try to create the share */
345 	resp->status = nlmsvc_share_file(host, file, argp);
346 
347 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
348 	nlm_release_host(host);
349 	nlm_release_file(file);
350 	return rpc_success;
351 }
352 
353 /*
354  * UNSHARE: Release a DOS share.
355  */
356 static __be32
357 nlm4svc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
358 				            struct nlm_res  *resp)
359 {
360 	struct nlm_host	*host;
361 	struct nlm_file	*file;
362 
363 	dprintk("lockd: UNSHARE       called\n");
364 
365 	resp->cookie = argp->cookie;
366 
367 	/* Don't accept requests during grace period */
368 	if (nlmsvc_grace_period) {
369 		resp->status = nlm_lck_denied_grace_period;
370 		return rpc_success;
371 	}
372 
373 	/* Obtain client and file */
374 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
375 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
376 
377 	/* Now try to lock the file */
378 	resp->status = nlmsvc_unshare_file(host, file, argp);
379 
380 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
381 	nlm_release_host(host);
382 	nlm_release_file(file);
383 	return rpc_success;
384 }
385 
386 /*
387  * NM_LOCK: Create an unmonitored lock
388  */
389 static __be32
390 nlm4svc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
391 				            struct nlm_res  *resp)
392 {
393 	dprintk("lockd: NM_LOCK       called\n");
394 
395 	argp->monitor = 0;		/* just clean the monitor flag */
396 	return nlm4svc_proc_lock(rqstp, argp, resp);
397 }
398 
399 /*
400  * FREE_ALL: Release all locks and shares held by client
401  */
402 static __be32
403 nlm4svc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
404 					     void            *resp)
405 {
406 	struct nlm_host	*host;
407 
408 	/* Obtain client */
409 	if (nlm4svc_retrieve_args(rqstp, argp, &host, NULL))
410 		return rpc_success;
411 
412 	nlmsvc_free_host_resources(host);
413 	nlm_release_host(host);
414 	return rpc_success;
415 }
416 
417 /*
418  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
419  */
420 static __be32
421 nlm4svc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
422 					      void	        *resp)
423 {
424 	struct sockaddr_in	saddr;
425 
426 	memcpy(&saddr, svc_addr_in(rqstp), sizeof(saddr));
427 
428 	dprintk("lockd: SM_NOTIFY     called\n");
429 	if (saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)
430 	 || ntohs(saddr.sin_port) >= 1024) {
431 		char buf[RPC_MAX_ADDRBUFLEN];
432 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
433 				svc_print_addr(rqstp, buf, sizeof(buf)));
434 		return rpc_system_err;
435 	}
436 
437 	/* Obtain the host pointer for this NFS server and try to
438 	 * reclaim all locks we hold on this server.
439 	 */
440 	memset(&saddr, 0, sizeof(saddr));
441 	saddr.sin_addr.s_addr = argp->addr;
442 	nlm_host_rebooted(&saddr, argp->mon, argp->len, argp->state);
443 
444 	return rpc_success;
445 }
446 
447 /*
448  * client sent a GRANTED_RES, let's remove the associated block
449  */
450 static __be32
451 nlm4svc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
452                                                 void            *resp)
453 {
454         if (!nlmsvc_ops)
455                 return rpc_success;
456 
457         dprintk("lockd: GRANTED_RES   called\n");
458 
459         nlmsvc_grant_reply(&argp->cookie, argp->status);
460         return rpc_success;
461 }
462 
463 
464 /*
465  * NLM Server procedures.
466  */
467 
468 #define nlm4svc_encode_norep	nlm4svc_encode_void
469 #define nlm4svc_decode_norep	nlm4svc_decode_void
470 #define nlm4svc_decode_testres	nlm4svc_decode_void
471 #define nlm4svc_decode_lockres	nlm4svc_decode_void
472 #define nlm4svc_decode_unlockres	nlm4svc_decode_void
473 #define nlm4svc_decode_cancelres	nlm4svc_decode_void
474 #define nlm4svc_decode_grantedres	nlm4svc_decode_void
475 
476 #define nlm4svc_proc_none	nlm4svc_proc_null
477 #define nlm4svc_proc_test_res	nlm4svc_proc_null
478 #define nlm4svc_proc_lock_res	nlm4svc_proc_null
479 #define nlm4svc_proc_cancel_res	nlm4svc_proc_null
480 #define nlm4svc_proc_unlock_res	nlm4svc_proc_null
481 
482 struct nlm_void			{ int dummy; };
483 
484 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
485  { .pc_func	= (svc_procfunc) nlm4svc_proc_##name,	\
486    .pc_decode	= (kxdrproc_t) nlm4svc_decode_##xargt,	\
487    .pc_encode	= (kxdrproc_t) nlm4svc_encode_##xrest,	\
488    .pc_release	= NULL,					\
489    .pc_argsize	= sizeof(struct nlm_##argt),		\
490    .pc_ressize	= sizeof(struct nlm_##rest),		\
491    .pc_xdrressize = respsize,				\
492  }
493 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
494 #define	No	(1+1024/4)				/* netobj */
495 #define	St	1					/* status */
496 #define	Rg	4					/* range (offset + length) */
497 struct svc_procedure		nlmsvc_procedures4[] = {
498   PROC(null,		void,		void,		void,	void, 1),
499   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
500   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
501   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
502   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
503   PROC(granted,		testargs,	res,		args,	res, Ck+St),
504   PROC(test_msg,	testargs,	norep,		args,	void, 1),
505   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
506   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
507   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
508   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
509   PROC(test_res,	testres,	norep,		res,	void, 1),
510   PROC(lock_res,	lockres,	norep,		res,	void, 1),
511   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
512   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
513   PROC(granted_res,	res,		norep,		res,	void, 1),
514   /* statd callback */
515   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
516   PROC(none,		void,		void,		void,	void, 0),
517   PROC(none,		void,		void,		void,	void, 0),
518   PROC(none,		void,		void,		void,	void, 0),
519   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
520   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
521   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
522   PROC(free_all,	notify,		void,		args,	void, 1),
523 
524 };
525