xref: /openbmc/linux/fs/lockd/svc4proc.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
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(rqstp, file, &argp->lock, &resp->lock, &resp->cookie);
103 	if (resp->status == nlm_drop_reply)
104 		return rpc_drop_reply;
105 
106 	dprintk("lockd: TEST4          status %d\n", ntohl(resp->status));
107 	nlm_release_host(host);
108 	nlm_release_file(file);
109 	return rpc_success;
110 }
111 
112 static __be32
113 nlm4svc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
114 				         struct nlm_res  *resp)
115 {
116 	struct nlm_host	*host;
117 	struct nlm_file	*file;
118 
119 	dprintk("lockd: LOCK          called\n");
120 
121 	resp->cookie = argp->cookie;
122 
123 	/* Don't accept new lock requests during grace period */
124 	if (nlmsvc_grace_period && !argp->reclaim) {
125 		resp->status = nlm_lck_denied_grace_period;
126 		return rpc_success;
127 	}
128 
129 	/* Obtain client and file */
130 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
131 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
132 
133 #if 0
134 	/* If supplied state doesn't match current state, we assume it's
135 	 * an old request that time-warped somehow. Any error return would
136 	 * do in this case because it's irrelevant anyway.
137 	 *
138 	 * NB: We don't retrieve the remote host's state yet.
139 	 */
140 	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
141 		resp->status = nlm_lck_denied_nolocks;
142 	} else
143 #endif
144 
145 	/* Now try to lock the file */
146 	resp->status = nlmsvc_lock(rqstp, file, &argp->lock,
147 					argp->block, &argp->cookie);
148 	if (resp->status == nlm_drop_reply)
149 		return rpc_drop_reply;
150 
151 	dprintk("lockd: LOCK          status %d\n", ntohl(resp->status));
152 	nlm_release_host(host);
153 	nlm_release_file(file);
154 	return rpc_success;
155 }
156 
157 static __be32
158 nlm4svc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
159 				           struct nlm_res  *resp)
160 {
161 	struct nlm_host	*host;
162 	struct nlm_file	*file;
163 
164 	dprintk("lockd: CANCEL        called\n");
165 
166 	resp->cookie = argp->cookie;
167 
168 	/* Don't accept requests during grace period */
169 	if (nlmsvc_grace_period) {
170 		resp->status = nlm_lck_denied_grace_period;
171 		return rpc_success;
172 	}
173 
174 	/* Obtain client and file */
175 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
176 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
177 
178 	/* Try to cancel request. */
179 	resp->status = nlmsvc_cancel_blocked(file, &argp->lock);
180 
181 	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
182 	nlm_release_host(host);
183 	nlm_release_file(file);
184 	return rpc_success;
185 }
186 
187 /*
188  * UNLOCK: release a lock
189  */
190 static __be32
191 nlm4svc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
192 				           struct nlm_res  *resp)
193 {
194 	struct nlm_host	*host;
195 	struct nlm_file	*file;
196 
197 	dprintk("lockd: UNLOCK        called\n");
198 
199 	resp->cookie = argp->cookie;
200 
201 	/* Don't accept new lock requests during grace period */
202 	if (nlmsvc_grace_period) {
203 		resp->status = nlm_lck_denied_grace_period;
204 		return rpc_success;
205 	}
206 
207 	/* Obtain client and file */
208 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
209 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
210 
211 	/* Now try to remove the lock */
212 	resp->status = nlmsvc_unlock(file, &argp->lock);
213 
214 	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
215 	nlm_release_host(host);
216 	nlm_release_file(file);
217 	return rpc_success;
218 }
219 
220 /*
221  * GRANTED: A server calls us to tell that a process' lock request
222  * was granted
223  */
224 static __be32
225 nlm4svc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
226 				            struct nlm_res  *resp)
227 {
228 	resp->cookie = argp->cookie;
229 
230 	dprintk("lockd: GRANTED       called\n");
231 	resp->status = nlmclnt_grant(svc_addr_in(rqstp), &argp->lock);
232 	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
233 	return rpc_success;
234 }
235 
236 /*
237  * This is the generic lockd callback for async RPC calls
238  */
239 static void nlm4svc_callback_exit(struct rpc_task *task, void *data)
240 {
241 	dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
242 			-task->tk_status);
243 }
244 
245 static void nlm4svc_callback_release(void *data)
246 {
247 	nlm_release_call(data);
248 }
249 
250 static const struct rpc_call_ops nlm4svc_callback_ops = {
251 	.rpc_call_done = nlm4svc_callback_exit,
252 	.rpc_release = nlm4svc_callback_release,
253 };
254 
255 /*
256  * `Async' versions of the above service routines. They aren't really,
257  * because we send the callback before the reply proper. I hope this
258  * doesn't break any clients.
259  */
260 static __be32 nlm4svc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
261 		__be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
262 {
263 	struct nlm_host	*host;
264 	struct nlm_rqst	*call;
265 	__be32 stat;
266 
267 	host = nlmsvc_lookup_host(rqstp,
268 				  argp->lock.caller,
269 				  argp->lock.len);
270 	if (host == NULL)
271 		return rpc_system_err;
272 
273 	call = nlm_alloc_call(host);
274 	if (call == NULL)
275 		return rpc_system_err;
276 
277 	stat = func(rqstp, argp, &call->a_res);
278 	if (stat != 0) {
279 		nlm_release_call(call);
280 		return stat;
281 	}
282 
283 	call->a_flags = RPC_TASK_ASYNC;
284 	if (nlm_async_reply(call, proc, &nlm4svc_callback_ops) < 0)
285 		return rpc_system_err;
286 	return rpc_success;
287 }
288 
289 static __be32 nlm4svc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
290 					     void	     *resp)
291 {
292 	dprintk("lockd: TEST_MSG      called\n");
293 	return nlm4svc_callback(rqstp, NLMPROC_TEST_RES, argp, nlm4svc_proc_test);
294 }
295 
296 static __be32 nlm4svc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
297 					     void	     *resp)
298 {
299 	dprintk("lockd: LOCK_MSG      called\n");
300 	return nlm4svc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlm4svc_proc_lock);
301 }
302 
303 static __be32 nlm4svc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
304 					       void	       *resp)
305 {
306 	dprintk("lockd: CANCEL_MSG    called\n");
307 	return nlm4svc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlm4svc_proc_cancel);
308 }
309 
310 static __be32 nlm4svc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
311                                                void            *resp)
312 {
313 	dprintk("lockd: UNLOCK_MSG    called\n");
314 	return nlm4svc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlm4svc_proc_unlock);
315 }
316 
317 static __be32 nlm4svc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
318                                                 void            *resp)
319 {
320 	dprintk("lockd: GRANTED_MSG   called\n");
321 	return nlm4svc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlm4svc_proc_granted);
322 }
323 
324 /*
325  * SHARE: create a DOS share or alter existing share.
326  */
327 static __be32
328 nlm4svc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
329 				          struct nlm_res  *resp)
330 {
331 	struct nlm_host	*host;
332 	struct nlm_file	*file;
333 
334 	dprintk("lockd: SHARE         called\n");
335 
336 	resp->cookie = argp->cookie;
337 
338 	/* Don't accept new lock requests during grace period */
339 	if (nlmsvc_grace_period && !argp->reclaim) {
340 		resp->status = nlm_lck_denied_grace_period;
341 		return rpc_success;
342 	}
343 
344 	/* Obtain client and file */
345 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
346 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
347 
348 	/* Now try to create the share */
349 	resp->status = nlmsvc_share_file(host, file, argp);
350 
351 	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
352 	nlm_release_host(host);
353 	nlm_release_file(file);
354 	return rpc_success;
355 }
356 
357 /*
358  * UNSHARE: Release a DOS share.
359  */
360 static __be32
361 nlm4svc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
362 				            struct nlm_res  *resp)
363 {
364 	struct nlm_host	*host;
365 	struct nlm_file	*file;
366 
367 	dprintk("lockd: UNSHARE       called\n");
368 
369 	resp->cookie = argp->cookie;
370 
371 	/* Don't accept requests during grace period */
372 	if (nlmsvc_grace_period) {
373 		resp->status = nlm_lck_denied_grace_period;
374 		return rpc_success;
375 	}
376 
377 	/* Obtain client and file */
378 	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
379 		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
380 
381 	/* Now try to lock the file */
382 	resp->status = nlmsvc_unshare_file(host, file, argp);
383 
384 	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
385 	nlm_release_host(host);
386 	nlm_release_file(file);
387 	return rpc_success;
388 }
389 
390 /*
391  * NM_LOCK: Create an unmonitored lock
392  */
393 static __be32
394 nlm4svc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
395 				            struct nlm_res  *resp)
396 {
397 	dprintk("lockd: NM_LOCK       called\n");
398 
399 	argp->monitor = 0;		/* just clean the monitor flag */
400 	return nlm4svc_proc_lock(rqstp, argp, resp);
401 }
402 
403 /*
404  * FREE_ALL: Release all locks and shares held by client
405  */
406 static __be32
407 nlm4svc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
408 					     void            *resp)
409 {
410 	struct nlm_host	*host;
411 
412 	/* Obtain client */
413 	if (nlm4svc_retrieve_args(rqstp, argp, &host, NULL))
414 		return rpc_success;
415 
416 	nlmsvc_free_host_resources(host);
417 	nlm_release_host(host);
418 	return rpc_success;
419 }
420 
421 /*
422  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
423  */
424 static __be32
425 nlm4svc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
426 					      void	        *resp)
427 {
428 	struct sockaddr_in	saddr;
429 
430 	memcpy(&saddr, svc_addr_in(rqstp), sizeof(saddr));
431 
432 	dprintk("lockd: SM_NOTIFY     called\n");
433 	if (saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)
434 	 || ntohs(saddr.sin_port) >= 1024) {
435 		char buf[RPC_MAX_ADDRBUFLEN];
436 		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
437 				svc_print_addr(rqstp, buf, sizeof(buf)));
438 		return rpc_system_err;
439 	}
440 
441 	/* Obtain the host pointer for this NFS server and try to
442 	 * reclaim all locks we hold on this server.
443 	 */
444 	memset(&saddr, 0, sizeof(saddr));
445 	saddr.sin_addr.s_addr = argp->addr;
446 	nlm_host_rebooted(&saddr, argp->mon, argp->len, argp->state);
447 
448 	return rpc_success;
449 }
450 
451 /*
452  * client sent a GRANTED_RES, let's remove the associated block
453  */
454 static __be32
455 nlm4svc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
456                                                 void            *resp)
457 {
458         if (!nlmsvc_ops)
459                 return rpc_success;
460 
461         dprintk("lockd: GRANTED_RES   called\n");
462 
463         nlmsvc_grant_reply(&argp->cookie, argp->status);
464         return rpc_success;
465 }
466 
467 
468 /*
469  * NLM Server procedures.
470  */
471 
472 #define nlm4svc_encode_norep	nlm4svc_encode_void
473 #define nlm4svc_decode_norep	nlm4svc_decode_void
474 #define nlm4svc_decode_testres	nlm4svc_decode_void
475 #define nlm4svc_decode_lockres	nlm4svc_decode_void
476 #define nlm4svc_decode_unlockres	nlm4svc_decode_void
477 #define nlm4svc_decode_cancelres	nlm4svc_decode_void
478 #define nlm4svc_decode_grantedres	nlm4svc_decode_void
479 
480 #define nlm4svc_proc_none	nlm4svc_proc_null
481 #define nlm4svc_proc_test_res	nlm4svc_proc_null
482 #define nlm4svc_proc_lock_res	nlm4svc_proc_null
483 #define nlm4svc_proc_cancel_res	nlm4svc_proc_null
484 #define nlm4svc_proc_unlock_res	nlm4svc_proc_null
485 
486 struct nlm_void			{ int dummy; };
487 
488 #define PROC(name, xargt, xrest, argt, rest, respsize)	\
489  { .pc_func	= (svc_procfunc) nlm4svc_proc_##name,	\
490    .pc_decode	= (kxdrproc_t) nlm4svc_decode_##xargt,	\
491    .pc_encode	= (kxdrproc_t) nlm4svc_encode_##xrest,	\
492    .pc_release	= NULL,					\
493    .pc_argsize	= sizeof(struct nlm_##argt),		\
494    .pc_ressize	= sizeof(struct nlm_##rest),		\
495    .pc_xdrressize = respsize,				\
496  }
497 #define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
498 #define	No	(1+1024/4)				/* netobj */
499 #define	St	1					/* status */
500 #define	Rg	4					/* range (offset + length) */
501 struct svc_procedure		nlmsvc_procedures4[] = {
502   PROC(null,		void,		void,		void,	void, 1),
503   PROC(test,		testargs,	testres,	args,	res, Ck+St+2+No+Rg),
504   PROC(lock,		lockargs,	res,		args,	res, Ck+St),
505   PROC(cancel,		cancargs,	res,		args,	res, Ck+St),
506   PROC(unlock,		unlockargs,	res,		args,	res, Ck+St),
507   PROC(granted,		testargs,	res,		args,	res, Ck+St),
508   PROC(test_msg,	testargs,	norep,		args,	void, 1),
509   PROC(lock_msg,	lockargs,	norep,		args,	void, 1),
510   PROC(cancel_msg,	cancargs,	norep,		args,	void, 1),
511   PROC(unlock_msg,	unlockargs,	norep,		args,	void, 1),
512   PROC(granted_msg,	testargs,	norep,		args,	void, 1),
513   PROC(test_res,	testres,	norep,		res,	void, 1),
514   PROC(lock_res,	lockres,	norep,		res,	void, 1),
515   PROC(cancel_res,	cancelres,	norep,		res,	void, 1),
516   PROC(unlock_res,	unlockres,	norep,		res,	void, 1),
517   PROC(granted_res,	res,		norep,		res,	void, 1),
518   /* statd callback */
519   PROC(sm_notify,	reboot,		void,		reboot,	void, 1),
520   PROC(none,		void,		void,		void,	void, 0),
521   PROC(none,		void,		void,		void,	void, 0),
522   PROC(none,		void,		void,		void,	void, 0),
523   PROC(share,		shareargs,	shareres,	args,	res, Ck+St+1),
524   PROC(unshare,		shareargs,	shareres,	args,	res, Ck+St+1),
525   PROC(nm_lock,		lockargs,	res,		args,	res, Ck+St),
526   PROC(free_all,	notify,		void,		args,	void, 1),
527 
528 };
529