xref: /openbmc/linux/fs/lockd/svc4proc.c (revision 22246614)
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 	int rc = rpc_success;
88 
89 	dprintk("lockd: TEST4        called\n");
90 	resp->cookie = argp->cookie;
91 
92 	/* Don't accept test requests during grace period */
93 	if (nlmsvc_grace_period) {
94 		resp->status = nlm_lck_denied_grace_period;
95 		return rc;
96 	}
97 
98 	/* Obtain client and file */
99 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
100 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
101 
102 	/* Now check for conflicting locks */
103 	resp->status = nlmsvc_testlock(rqstp, file, &argp->lock, &resp->lock, &resp->cookie);
104 	if (resp->status == nlm_drop_reply)
105 		rc = rpc_drop_reply;
106 	else
107 		dprintk("lockd: TEST4        status %d\n", ntohl(resp->status));
108 
109 	nlm_release_host(host);
110 	nlm_release_file(file);
111 	return rc;
112 }
113 
114 static __be32
115 nlm4svc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
116 				         struct nlm_res  *resp)
117 {
118 	struct nlm_host	*host;
119 	struct nlm_file	*file;
120 	int rc = rpc_success;
121 
122 	dprintk("lockd: LOCK          called\n");
123 
124 	resp->cookie = argp->cookie;
125 
126 	/* Don't accept new lock requests during grace period */
127 	if (nlmsvc_grace_period && !argp->reclaim) {
128 		resp->status = nlm_lck_denied_grace_period;
129 		return rc;
130 	}
131 
132 	/* Obtain client and file */
133 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
134 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
135 
136 #if 0
137 	/* If supplied state doesn't match current state, we assume it's
138 	 * an old request that time-warped somehow. Any error return would
139 	 * do in this case because it's irrelevant anyway.
140 	 *
141 	 * NB: We don't retrieve the remote host's state yet.
142 	 */
143 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
144 		resp->status = nlm_lck_denied_nolocks;
145 	} else
146 #endif
147 
148 	/* Now try to lock the file */
149 	resp->status = nlmsvc_lock(rqstp, file, &argp->lock,
150 					argp->block, &argp->cookie);
151 	if (resp->status == nlm_drop_reply)
152 		rc = rpc_drop_reply;
153 	else
154 		dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
155 
156 	nlm_release_host(host);
157 	nlm_release_file(file);
158 	return rc;
159 }
160 
161 static __be32
162 nlm4svc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
163 				           struct nlm_res  *resp)
164 {
165 	struct nlm_host	*host;
166 	struct nlm_file	*file;
167 
168 	dprintk("lockd: CANCEL        called\n");
169 
170 	resp->cookie = argp->cookie;
171 
172 	/* Don't accept requests during grace period */
173 	if (nlmsvc_grace_period) {
174 		resp->status = nlm_lck_denied_grace_period;
175 		return rpc_success;
176 	}
177 
178 	/* Obtain client and file */
179 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
180 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
181 
182 	/* Try to cancel request. */
183 	resp->status = nlmsvc_cancel_blocked(file, &argp->lock);
184 
185 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
186 	nlm_release_host(host);
187 	nlm_release_file(file);
188 	return rpc_success;
189 }
190 
191 /*
192  * UNLOCK: release a lock
193  */
194 static __be32
195 nlm4svc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
196 				           struct nlm_res  *resp)
197 {
198 	struct nlm_host	*host;
199 	struct nlm_file	*file;
200 
201 	dprintk("lockd: UNLOCK        called\n");
202 
203 	resp->cookie = argp->cookie;
204 
205 	/* Don't accept new lock requests during grace period */
206 	if (nlmsvc_grace_period) {
207 		resp->status = nlm_lck_denied_grace_period;
208 		return rpc_success;
209 	}
210 
211 	/* Obtain client and file */
212 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
213 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
214 
215 	/* Now try to remove the lock */
216 	resp->status = nlmsvc_unlock(file, &argp->lock);
217 
218 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
219 	nlm_release_host(host);
220 	nlm_release_file(file);
221 	return rpc_success;
222 }
223 
224 /*
225  * GRANTED: A server calls us to tell that a process' lock request
226  * was granted
227  */
228 static __be32
229 nlm4svc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
230 				            struct nlm_res  *resp)
231 {
232 	resp->cookie = argp->cookie;
233 
234 	dprintk("lockd: GRANTED       called\n");
235 	resp->status = nlmclnt_grant(svc_addr_in(rqstp), &argp->lock);
236 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
237 	return rpc_success;
238 }
239 
240 /*
241  * This is the generic lockd callback for async RPC calls
242  */
243 static void nlm4svc_callback_exit(struct rpc_task *task, void *data)
244 {
245 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
246 			-task->tk_status);
247 }
248 
249 static void nlm4svc_callback_release(void *data)
250 {
251 	nlm_release_call(data);
252 }
253 
254 static const struct rpc_call_ops nlm4svc_callback_ops = {
255 	.rpc_call_done = nlm4svc_callback_exit,
256 	.rpc_release = nlm4svc_callback_release,
257 };
258 
259 /*
260  * `Async' versions of the above service routines. They aren't really,
261  * because we send the callback before the reply proper. I hope this
262  * doesn't break any clients.
263  */
264 static __be32 nlm4svc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
265 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
266 {
267 	struct nlm_host	*host;
268 	struct nlm_rqst	*call;
269 	__be32 stat;
270 
271 	host = nlmsvc_lookup_host(rqstp,
272 				  argp->lock.caller,
273 				  argp->lock.len);
274 	if (host == NULL)
275 		return rpc_system_err;
276 
277 	call = nlm_alloc_call(host);
278 	if (call == NULL)
279 		return rpc_system_err;
280 
281 	stat = func(rqstp, argp, &call->a_res);
282 	if (stat != 0) {
283 		nlm_release_call(call);
284 		return stat;
285 	}
286 
287 	call->a_flags = RPC_TASK_ASYNC;
288 	if (nlm_async_reply(call, proc, &nlm4svc_callback_ops) < 0)
289 		return rpc_system_err;
290 	return rpc_success;
291 }
292 
293 static __be32 nlm4svc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
294 					     void	     *resp)
295 {
296 	dprintk("lockd: TEST_MSG      called\n");
297 	return nlm4svc_callback(rqstp, NLMPROC_TEST_RES, argp, nlm4svc_proc_test);
298 }
299 
300 static __be32 nlm4svc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
301 					     void	     *resp)
302 {
303 	dprintk("lockd: LOCK_MSG      called\n");
304 	return nlm4svc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlm4svc_proc_lock);
305 }
306 
307 static __be32 nlm4svc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
308 					       void	       *resp)
309 {
310 	dprintk("lockd: CANCEL_MSG    called\n");
311 	return nlm4svc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlm4svc_proc_cancel);
312 }
313 
314 static __be32 nlm4svc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
315                                                void            *resp)
316 {
317 	dprintk("lockd: UNLOCK_MSG    called\n");
318 	return nlm4svc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlm4svc_proc_unlock);
319 }
320 
321 static __be32 nlm4svc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
322                                                 void            *resp)
323 {
324 	dprintk("lockd: GRANTED_MSG   called\n");
325 	return nlm4svc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlm4svc_proc_granted);
326 }
327 
328 /*
329  * SHARE: create a DOS share or alter existing share.
330  */
331 static __be32
332 nlm4svc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
333 				          struct nlm_res  *resp)
334 {
335 	struct nlm_host	*host;
336 	struct nlm_file	*file;
337 
338 	dprintk("lockd: SHARE         called\n");
339 
340 	resp->cookie = argp->cookie;
341 
342 	/* Don't accept new lock requests during grace period */
343 	if (nlmsvc_grace_period && !argp->reclaim) {
344 		resp->status = nlm_lck_denied_grace_period;
345 		return rpc_success;
346 	}
347 
348 	/* Obtain client and file */
349 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
350 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
351 
352 	/* Now try to create the share */
353 	resp->status = nlmsvc_share_file(host, file, argp);
354 
355 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
356 	nlm_release_host(host);
357 	nlm_release_file(file);
358 	return rpc_success;
359 }
360 
361 /*
362  * UNSHARE: Release a DOS share.
363  */
364 static __be32
365 nlm4svc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
366 				            struct nlm_res  *resp)
367 {
368 	struct nlm_host	*host;
369 	struct nlm_file	*file;
370 
371 	dprintk("lockd: UNSHARE       called\n");
372 
373 	resp->cookie = argp->cookie;
374 
375 	/* Don't accept requests during grace period */
376 	if (nlmsvc_grace_period) {
377 		resp->status = nlm_lck_denied_grace_period;
378 		return rpc_success;
379 	}
380 
381 	/* Obtain client and file */
382 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
383 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
384 
385 	/* Now try to lock the file */
386 	resp->status = nlmsvc_unshare_file(host, file, argp);
387 
388 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
389 	nlm_release_host(host);
390 	nlm_release_file(file);
391 	return rpc_success;
392 }
393 
394 /*
395  * NM_LOCK: Create an unmonitored lock
396  */
397 static __be32
398 nlm4svc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
399 				            struct nlm_res  *resp)
400 {
401 	dprintk("lockd: NM_LOCK       called\n");
402 
403 	argp->monitor = 0;		/* just clean the monitor flag */
404 	return nlm4svc_proc_lock(rqstp, argp, resp);
405 }
406 
407 /*
408  * FREE_ALL: Release all locks and shares held by client
409  */
410 static __be32
411 nlm4svc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
412 					     void            *resp)
413 {
414 	struct nlm_host	*host;
415 
416 	/* Obtain client */
417 	if (nlm4svc_retrieve_args(rqstp, argp, &host, NULL))
418 		return rpc_success;
419 
420 	nlmsvc_free_host_resources(host);
421 	nlm_release_host(host);
422 	return rpc_success;
423 }
424 
425 /*
426  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
427  */
428 static __be32
429 nlm4svc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
430 					      void	        *resp)
431 {
432 	struct sockaddr_in	saddr;
433 
434 	memcpy(&saddr, svc_addr_in(rqstp), sizeof(saddr));
435 
436 	dprintk("lockd: SM_NOTIFY     called\n");
437 	if (saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)
438 	 || ntohs(saddr.sin_port) >= 1024) {
439 		char buf[RPC_MAX_ADDRBUFLEN];
440 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
441 				svc_print_addr(rqstp, buf, sizeof(buf)));
442 		return rpc_system_err;
443 	}
444 
445 	/* Obtain the host pointer for this NFS server and try to
446 	 * reclaim all locks we hold on this server.
447 	 */
448 	memset(&saddr, 0, sizeof(saddr));
449 	saddr.sin_addr.s_addr = argp->addr;
450 	nlm_host_rebooted(&saddr, argp->mon, argp->len, argp->state);
451 
452 	return rpc_success;
453 }
454 
455 /*
456  * client sent a GRANTED_RES, let's remove the associated block
457  */
458 static __be32
459 nlm4svc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
460                                                 void            *resp)
461 {
462         if (!nlmsvc_ops)
463                 return rpc_success;
464 
465         dprintk("lockd: GRANTED_RES   called\n");
466 
467         nlmsvc_grant_reply(&argp->cookie, argp->status);
468         return rpc_success;
469 }
470 
471 
472 /*
473  * NLM Server procedures.
474  */
475 
476 #define nlm4svc_encode_norep	nlm4svc_encode_void
477 #define nlm4svc_decode_norep	nlm4svc_decode_void
478 #define nlm4svc_decode_testres	nlm4svc_decode_void
479 #define nlm4svc_decode_lockres	nlm4svc_decode_void
480 #define nlm4svc_decode_unlockres	nlm4svc_decode_void
481 #define nlm4svc_decode_cancelres	nlm4svc_decode_void
482 #define nlm4svc_decode_grantedres	nlm4svc_decode_void
483 
484 #define nlm4svc_proc_none	nlm4svc_proc_null
485 #define nlm4svc_proc_test_res	nlm4svc_proc_null
486 #define nlm4svc_proc_lock_res	nlm4svc_proc_null
487 #define nlm4svc_proc_cancel_res	nlm4svc_proc_null
488 #define nlm4svc_proc_unlock_res	nlm4svc_proc_null
489 
490 struct nlm_void			{ int dummy; };
491 
492 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
493  { .pc_func	= (svc_procfunc) nlm4svc_proc_##name,	\
494    .pc_decode	= (kxdrproc_t) nlm4svc_decode_##xargt,	\
495    .pc_encode	= (kxdrproc_t) nlm4svc_encode_##xrest,	\
496    .pc_release	= NULL,					\
497    .pc_argsize	= sizeof(struct nlm_##argt),		\
498    .pc_ressize	= sizeof(struct nlm_##rest),		\
499    .pc_xdrressize = respsize,				\
500  }
501 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
502 #define	No	(1+1024/4)				/* netobj */
503 #define	St	1					/* status */
504 #define	Rg	4					/* range (offset + length) */
505 struct svc_procedure		nlmsvc_procedures4[] = {
506   PROC(null,		void,		void,		void,	void, 1),
507   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
508   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
509   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
510   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
511   PROC(granted,		testargs,	res,		args,	res, Ck+St),
512   PROC(test_msg,	testargs,	norep,		args,	void, 1),
513   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
514   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
515   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
516   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
517   PROC(test_res,	testres,	norep,		res,	void, 1),
518   PROC(lock_res,	lockres,	norep,		res,	void, 1),
519   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
520   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
521   PROC(granted_res,	res,		norep,		res,	void, 1),
522   /* statd callback */
523   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
524   PROC(none,		void,		void,		void,	void, 0),
525   PROC(none,		void,		void,		void,	void, 0),
526   PROC(none,		void,		void,		void,	void, 0),
527   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
528   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
529   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
530   PROC(free_all,	notify,		void,		args,	void, 1),
531 
532 };
533