xref: /openbmc/linux/fs/lockd/svcproc.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
1 /*
2  * linux/fs/lockd/svcproc.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 #ifdef CONFIG_LOCKD_V4
25 static __be32
26 cast_to_nlm(__be32 status, u32 vers)
27 {
28 	/* Note: status is assumed to be in network byte order !!! */
29 	if (vers != 4){
30 		switch (status) {
31 		case nlm_granted:
32 		case nlm_lck_denied:
33 		case nlm_lck_denied_nolocks:
34 		case nlm_lck_blocked:
35 		case nlm_lck_denied_grace_period:
36 		case nlm_drop_reply:
37 			break;
38 		case nlm4_deadlock:
39 			status = nlm_lck_denied;
40 			break;
41 		default:
42 			status = nlm_lck_denied_nolocks;
43 		}
44 	}
45 
46 	return (status);
47 }
48 #define	cast_status(status) (cast_to_nlm(status, rqstp->rq_vers))
49 #else
50 #define cast_status(status) (status)
51 #endif
52 
53 /*
54  * Obtain client and file from arguments
55  */
56 static __be32
57 nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
58 			struct nlm_host **hostp, struct nlm_file **filp)
59 {
60 	struct nlm_host		*host = NULL;
61 	struct nlm_file		*file = NULL;
62 	struct nlm_lock		*lock = &argp->lock;
63 	__be32			error = 0;
64 
65 	/* nfsd callbacks must have been installed for this procedure */
66 	if (!nlmsvc_ops)
67 		return nlm_lck_denied_nolocks;
68 
69 	/* Obtain host handle */
70 	if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
71 	 || (argp->monitor && nsm_monitor(host) < 0))
72 		goto no_locks;
73 	*hostp = host;
74 
75 	/* Obtain file pointer. Not used by FREE_ALL call. */
76 	if (filp != NULL) {
77 		if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
78 			goto no_locks;
79 		*filp = file;
80 
81 		/* Set up the missing parts of the file_lock structure */
82 		lock->fl.fl_file  = file->f_file;
83 		lock->fl.fl_owner = (fl_owner_t) host;
84 		lock->fl.fl_lmops = &nlmsvc_lock_operations;
85 	}
86 
87 	return 0;
88 
89 no_locks:
90 	if (host)
91 		nlm_release_host(host);
92 	if (error)
93 		return error;
94 	return nlm_lck_denied_nolocks;
95 }
96 
97 /*
98  * NULL: Test for presence of service
99  */
100 static __be32
101 nlmsvc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
102 {
103 	dprintk("lockd: NULL          called\n");
104 	return rpc_success;
105 }
106 
107 /*
108  * TEST: Check for conflicting lock
109  */
110 static __be32
111 nlmsvc_proc_test(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: TEST          called\n");
118 	resp->cookie = argp->cookie;
119 
120 	/* Don't accept test requests during grace period */
121 	if (nlmsvc_grace_period) {
122 		resp->status = nlm_lck_denied_grace_period;
123 		return rpc_success;
124 	}
125 
126 	/* Obtain client and file */
127 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
128 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
129 
130 	/* Now check for conflicting locks */
131 	resp->status = cast_status(nlmsvc_testlock(rqstp, file, &argp->lock, &resp->lock, &resp->cookie));
132 	if (resp->status == nlm_drop_reply)
133 		return rpc_drop_reply;
134 
135 	dprintk("lockd: TEST          status %d vers %d\n",
136 		ntohl(resp->status), rqstp->rq_vers);
137 	nlm_release_host(host);
138 	nlm_release_file(file);
139 	return rpc_success;
140 }
141 
142 static __be32
143 nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
144 				         struct nlm_res  *resp)
145 {
146 	struct nlm_host	*host;
147 	struct nlm_file	*file;
148 
149 	dprintk("lockd: LOCK          called\n");
150 
151 	resp->cookie = argp->cookie;
152 
153 	/* Don't accept new lock requests during grace period */
154 	if (nlmsvc_grace_period && !argp->reclaim) {
155 		resp->status = nlm_lck_denied_grace_period;
156 		return rpc_success;
157 	}
158 
159 	/* Obtain client and file */
160 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
161 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
162 
163 #if 0
164 	/* If supplied state doesn't match current state, we assume it's
165 	 * an old request that time-warped somehow. Any error return would
166 	 * do in this case because it's irrelevant anyway.
167 	 *
168 	 * NB: We don't retrieve the remote host's state yet.
169 	 */
170 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
171 		resp->status = nlm_lck_denied_nolocks;
172 	} else
173 #endif
174 
175 	/* Now try to lock the file */
176 	resp->status = cast_status(nlmsvc_lock(rqstp, file, &argp->lock,
177 					       argp->block, &argp->cookie));
178 	if (resp->status == nlm_drop_reply)
179 		return rpc_drop_reply;
180 
181 	dprintk("lockd: LOCK          status %d\n", ntohl(resp->status));
182 	nlm_release_host(host);
183 	nlm_release_file(file);
184 	return rpc_success;
185 }
186 
187 static __be32
188 nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
189 				           struct nlm_res  *resp)
190 {
191 	struct nlm_host	*host;
192 	struct nlm_file	*file;
193 
194 	dprintk("lockd: CANCEL        called\n");
195 
196 	resp->cookie = argp->cookie;
197 
198 	/* Don't accept requests during grace period */
199 	if (nlmsvc_grace_period) {
200 		resp->status = nlm_lck_denied_grace_period;
201 		return rpc_success;
202 	}
203 
204 	/* Obtain client and file */
205 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
206 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
207 
208 	/* Try to cancel request. */
209 	resp->status = cast_status(nlmsvc_cancel_blocked(file, &argp->lock));
210 
211 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
212 	nlm_release_host(host);
213 	nlm_release_file(file);
214 	return rpc_success;
215 }
216 
217 /*
218  * UNLOCK: release a lock
219  */
220 static __be32
221 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
222 				           struct nlm_res  *resp)
223 {
224 	struct nlm_host	*host;
225 	struct nlm_file	*file;
226 
227 	dprintk("lockd: UNLOCK        called\n");
228 
229 	resp->cookie = argp->cookie;
230 
231 	/* Don't accept new lock requests during grace period */
232 	if (nlmsvc_grace_period) {
233 		resp->status = nlm_lck_denied_grace_period;
234 		return rpc_success;
235 	}
236 
237 	/* Obtain client and file */
238 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
239 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
240 
241 	/* Now try to remove the lock */
242 	resp->status = cast_status(nlmsvc_unlock(file, &argp->lock));
243 
244 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
245 	nlm_release_host(host);
246 	nlm_release_file(file);
247 	return rpc_success;
248 }
249 
250 /*
251  * GRANTED: A server calls us to tell that a process' lock request
252  * was granted
253  */
254 static __be32
255 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
256 				            struct nlm_res  *resp)
257 {
258 	resp->cookie = argp->cookie;
259 
260 	dprintk("lockd: GRANTED       called\n");
261 	resp->status = nlmclnt_grant(svc_addr_in(rqstp), &argp->lock);
262 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
263 	return rpc_success;
264 }
265 
266 /*
267  * This is the generic lockd callback for async RPC calls
268  */
269 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
270 {
271 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
272 			-task->tk_status);
273 }
274 
275 static void nlmsvc_callback_release(void *data)
276 {
277 	nlm_release_call(data);
278 }
279 
280 static const struct rpc_call_ops nlmsvc_callback_ops = {
281 	.rpc_call_done = nlmsvc_callback_exit,
282 	.rpc_release = nlmsvc_callback_release,
283 };
284 
285 /*
286  * `Async' versions of the above service routines. They aren't really,
287  * because we send the callback before the reply proper. I hope this
288  * doesn't break any clients.
289  */
290 static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
291 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
292 {
293 	struct nlm_host	*host;
294 	struct nlm_rqst	*call;
295 	__be32 stat;
296 
297 	host = nlmsvc_lookup_host(rqstp,
298 				  argp->lock.caller,
299 				  argp->lock.len);
300 	if (host == NULL)
301 		return rpc_system_err;
302 
303 	call = nlm_alloc_call(host);
304 	if (call == NULL)
305 		return rpc_system_err;
306 
307 	stat = func(rqstp, argp, &call->a_res);
308 	if (stat != 0) {
309 		nlm_release_call(call);
310 		return stat;
311 	}
312 
313 	call->a_flags = RPC_TASK_ASYNC;
314 	if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
315 		return rpc_system_err;
316 	return rpc_success;
317 }
318 
319 static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
320 					     void	     *resp)
321 {
322 	dprintk("lockd: TEST_MSG      called\n");
323 	return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
324 }
325 
326 static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
327 					     void	     *resp)
328 {
329 	dprintk("lockd: LOCK_MSG      called\n");
330 	return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
331 }
332 
333 static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
334 					       void	       *resp)
335 {
336 	dprintk("lockd: CANCEL_MSG    called\n");
337 	return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
338 }
339 
340 static __be32
341 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
342                                                void            *resp)
343 {
344 	dprintk("lockd: UNLOCK_MSG    called\n");
345 	return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
346 }
347 
348 static __be32
349 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
350                                                 void            *resp)
351 {
352 	dprintk("lockd: GRANTED_MSG   called\n");
353 	return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
354 }
355 
356 /*
357  * SHARE: create a DOS share or alter existing share.
358  */
359 static __be32
360 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
361 				          struct nlm_res  *resp)
362 {
363 	struct nlm_host	*host;
364 	struct nlm_file	*file;
365 
366 	dprintk("lockd: SHARE         called\n");
367 
368 	resp->cookie = argp->cookie;
369 
370 	/* Don't accept new lock requests during grace period */
371 	if (nlmsvc_grace_period && !argp->reclaim) {
372 		resp->status = nlm_lck_denied_grace_period;
373 		return rpc_success;
374 	}
375 
376 	/* Obtain client and file */
377 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
378 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
379 
380 	/* Now try to create the share */
381 	resp->status = cast_status(nlmsvc_share_file(host, file, argp));
382 
383 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
384 	nlm_release_host(host);
385 	nlm_release_file(file);
386 	return rpc_success;
387 }
388 
389 /*
390  * UNSHARE: Release a DOS share.
391  */
392 static __be32
393 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
394 				            struct nlm_res  *resp)
395 {
396 	struct nlm_host	*host;
397 	struct nlm_file	*file;
398 
399 	dprintk("lockd: UNSHARE       called\n");
400 
401 	resp->cookie = argp->cookie;
402 
403 	/* Don't accept requests during grace period */
404 	if (nlmsvc_grace_period) {
405 		resp->status = nlm_lck_denied_grace_period;
406 		return rpc_success;
407 	}
408 
409 	/* Obtain client and file */
410 	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
411 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
412 
413 	/* Now try to unshare the file */
414 	resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
415 
416 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
417 	nlm_release_host(host);
418 	nlm_release_file(file);
419 	return rpc_success;
420 }
421 
422 /*
423  * NM_LOCK: Create an unmonitored lock
424  */
425 static __be32
426 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
427 				            struct nlm_res  *resp)
428 {
429 	dprintk("lockd: NM_LOCK       called\n");
430 
431 	argp->monitor = 0;		/* just clean the monitor flag */
432 	return nlmsvc_proc_lock(rqstp, argp, resp);
433 }
434 
435 /*
436  * FREE_ALL: Release all locks and shares held by client
437  */
438 static __be32
439 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
440 					     void            *resp)
441 {
442 	struct nlm_host	*host;
443 
444 	/* Obtain client */
445 	if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
446 		return rpc_success;
447 
448 	nlmsvc_free_host_resources(host);
449 	nlm_release_host(host);
450 	return rpc_success;
451 }
452 
453 /*
454  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
455  */
456 static __be32
457 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
458 					      void	        *resp)
459 {
460 	struct sockaddr_in	saddr;
461 
462 	memcpy(&saddr, svc_addr_in(rqstp), sizeof(saddr));
463 
464 	dprintk("lockd: SM_NOTIFY     called\n");
465 	if (saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)
466 	 || ntohs(saddr.sin_port) >= 1024) {
467 		char buf[RPC_MAX_ADDRBUFLEN];
468 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
469 				svc_print_addr(rqstp, buf, sizeof(buf)));
470 		return rpc_system_err;
471 	}
472 
473 	/* Obtain the host pointer for this NFS server and try to
474 	 * reclaim all locks we hold on this server.
475 	 */
476 	memset(&saddr, 0, sizeof(saddr));
477 	saddr.sin_addr.s_addr = argp->addr;
478 	nlm_host_rebooted(&saddr, argp->mon, argp->len, argp->state);
479 
480 	return rpc_success;
481 }
482 
483 /*
484  * client sent a GRANTED_RES, let's remove the associated block
485  */
486 static __be32
487 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
488                                                 void            *resp)
489 {
490 	if (!nlmsvc_ops)
491 		return rpc_success;
492 
493 	dprintk("lockd: GRANTED_RES   called\n");
494 
495 	nlmsvc_grant_reply(&argp->cookie, argp->status);
496 	return rpc_success;
497 }
498 
499 /*
500  * NLM Server procedures.
501  */
502 
503 #define nlmsvc_encode_norep	nlmsvc_encode_void
504 #define nlmsvc_decode_norep	nlmsvc_decode_void
505 #define nlmsvc_decode_testres	nlmsvc_decode_void
506 #define nlmsvc_decode_lockres	nlmsvc_decode_void
507 #define nlmsvc_decode_unlockres	nlmsvc_decode_void
508 #define nlmsvc_decode_cancelres	nlmsvc_decode_void
509 #define nlmsvc_decode_grantedres	nlmsvc_decode_void
510 
511 #define nlmsvc_proc_none	nlmsvc_proc_null
512 #define nlmsvc_proc_test_res	nlmsvc_proc_null
513 #define nlmsvc_proc_lock_res	nlmsvc_proc_null
514 #define nlmsvc_proc_cancel_res	nlmsvc_proc_null
515 #define nlmsvc_proc_unlock_res	nlmsvc_proc_null
516 
517 struct nlm_void			{ int dummy; };
518 
519 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
520  { .pc_func	= (svc_procfunc) nlmsvc_proc_##name,	\
521    .pc_decode	= (kxdrproc_t) nlmsvc_decode_##xargt,	\
522    .pc_encode	= (kxdrproc_t) nlmsvc_encode_##xrest,	\
523    .pc_release	= NULL,					\
524    .pc_argsize	= sizeof(struct nlm_##argt),		\
525    .pc_ressize	= sizeof(struct nlm_##rest),		\
526    .pc_xdrressize = respsize,				\
527  }
528 
529 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
530 #define	St	1				/* status */
531 #define	No	(1+1024/4)			/* Net Obj */
532 #define	Rg	2				/* range - offset + size */
533 
534 struct svc_procedure		nlmsvc_procedures[] = {
535   PROC(null,		void,		void,		void,	void, 1),
536   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
537   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
538   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
539   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
540   PROC(granted,		testargs,	res,		args,	res, Ck+St),
541   PROC(test_msg,	testargs,	norep,		args,	void, 1),
542   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
543   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
544   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
545   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
546   PROC(test_res,	testres,	norep,		res,	void, 1),
547   PROC(lock_res,	lockres,	norep,		res,	void, 1),
548   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
549   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
550   PROC(granted_res,	res,		norep,		res,	void, 1),
551   /* statd callback */
552   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
553   PROC(none,		void,		void,		void,	void, 1),
554   PROC(none,		void,		void,		void,	void, 1),
555   PROC(none,		void,		void,		void,	void, 1),
556   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
557   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
558   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
559   PROC(free_all,	notify,		void,		args,	void, 0),
560 
561 };
562