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svcproc.c
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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 <[email protected]>
8  */
9 
10 #include <linux/types.h>
11 #include <linux/time.h>
12 #include <linux/lockd/lockd.h>
13 #include <linux/lockd/share.h>
14 #include <linux/sunrpc/svc_xprt.h>
15 
16 #define NLMDBG_FACILITY NLMDBG_CLIENT
17 
18 #ifdef CONFIG_LOCKD_V4
19 static __be32
20 cast_to_nlm(__be32 status, u32 vers)
21 {
22  /* Note: status is assumed to be in network byte order !!! */
23  if (vers != 4){
24  switch (status) {
25  case nlm_granted:
26  case nlm_lck_denied:
27  case nlm_lck_denied_nolocks:
28  case nlm_lck_blocked:
29  case nlm_lck_denied_grace_period:
30  case nlm_drop_reply:
31  break;
32  case nlm4_deadlock:
33  status = nlm_lck_denied;
34  break;
35  default:
36  status = nlm_lck_denied_nolocks;
37  }
38  }
39 
40  return (status);
41 }
42 #define cast_status(status) (cast_to_nlm(status, rqstp->rq_vers))
43 #else
44 #define cast_status(status) (status)
45 #endif
46 
47 /*
48  * Obtain client and file from arguments
49  */
50 static __be32
51 nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
52  struct nlm_host **hostp, struct nlm_file **filp)
53 {
54  struct nlm_host *host = NULL;
55  struct nlm_file *file = NULL;
56  struct nlm_lock *lock = &argp->lock;
57  __be32 error = 0;
58 
59  /* nfsd callbacks must have been installed for this procedure */
60  if (!nlmsvc_ops)
61  return nlm_lck_denied_nolocks;
62 
63  /* Obtain host handle */
64  if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
65  || (argp->monitor && nsm_monitor(host) < 0))
66  goto no_locks;
67  *hostp = host;
68 
69  /* Obtain file pointer. Not used by FREE_ALL call. */
70  if (filp != NULL) {
71  error = cast_status(nlm_lookup_file(rqstp, &file, &lock->fh));
72  if (error != 0)
73  goto no_locks;
74  *filp = file;
75 
76  /* Set up the missing parts of the file_lock structure */
77  lock->fl.fl_file = file->f_file;
78  lock->fl.fl_owner = (fl_owner_t) host;
79  lock->fl.fl_lmops = &nlmsvc_lock_operations;
80  }
81 
82  return 0;
83 
84 no_locks:
85  nlmsvc_release_host(host);
86  if (error)
87  return error;
88  return nlm_lck_denied_nolocks;
89 }
90 
91 /*
92  * NULL: Test for presence of service
93  */
94 static __be32
95 nlmsvc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
96 {
97  dprintk("lockd: NULL called\n");
98  return rpc_success;
99 }
100 
101 /*
102  * TEST: Check for conflicting lock
103  */
104 static __be32
105 nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
106  struct nlm_res *resp)
107 {
108  struct nlm_host *host;
109  struct nlm_file *file;
110  __be32 rc = rpc_success;
111 
112  dprintk("lockd: TEST called\n");
113  resp->cookie = argp->cookie;
114 
115  /* Obtain client and file */
116  if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
117  return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
118 
119  /* Now check for conflicting locks */
120  resp->status = cast_status(nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie));
121  if (resp->status == nlm_drop_reply)
122  rc = rpc_drop_reply;
123  else
124  dprintk("lockd: TEST status %d vers %d\n",
125  ntohl(resp->status), rqstp->rq_vers);
126 
127  nlmsvc_release_host(host);
128  nlm_release_file(file);
129  return rc;
130 }
131 
132 static __be32
133 nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
134  struct nlm_res *resp)
135 {
136  struct nlm_host *host;
137  struct nlm_file *file;
138  __be32 rc = rpc_success;
139 
140  dprintk("lockd: LOCK called\n");
141 
142  resp->cookie = argp->cookie;
143 
144  /* Obtain client and file */
145  if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
146  return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
147 
148 #if 0
149  /* If supplied state doesn't match current state, we assume it's
150  * an old request that time-warped somehow. Any error return would
151  * do in this case because it's irrelevant anyway.
152  *
153  * NB: We don't retrieve the remote host's state yet.
154  */
155  if (host->h_nsmstate && host->h_nsmstate != argp->state) {
156  resp->status = nlm_lck_denied_nolocks;
157  } else
158 #endif
159 
160  /* Now try to lock the file */
161  resp->status = cast_status(nlmsvc_lock(rqstp, file, host, &argp->lock,
162  argp->block, &argp->cookie,
163  argp->reclaim));
164  if (resp->status == nlm_drop_reply)
165  rc = rpc_drop_reply;
166  else
167  dprintk("lockd: LOCK status %d\n", ntohl(resp->status));
168 
169  nlmsvc_release_host(host);
170  nlm_release_file(file);
171  return rc;
172 }
173 
174 static __be32
175 nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
176  struct nlm_res *resp)
177 {
178  struct nlm_host *host;
179  struct nlm_file *file;
180  struct net *net = SVC_NET(rqstp);
181 
182  dprintk("lockd: CANCEL called\n");
183 
184  resp->cookie = argp->cookie;
185 
186  /* Don't accept requests during grace period */
187  if (locks_in_grace(net)) {
188  resp->status = nlm_lck_denied_grace_period;
189  return rpc_success;
190  }
191 
192  /* Obtain client and file */
193  if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
194  return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
195 
196  /* Try to cancel request. */
197  resp->status = cast_status(nlmsvc_cancel_blocked(net, file, &argp->lock));
198 
199  dprintk("lockd: CANCEL status %d\n", ntohl(resp->status));
200  nlmsvc_release_host(host);
201  nlm_release_file(file);
202  return rpc_success;
203 }
204 
205 /*
206  * UNLOCK: release a lock
207  */
208 static __be32
209 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
210  struct nlm_res *resp)
211 {
212  struct nlm_host *host;
213  struct nlm_file *file;
214  struct net *net = SVC_NET(rqstp);
215 
216  dprintk("lockd: UNLOCK called\n");
217 
218  resp->cookie = argp->cookie;
219 
220  /* Don't accept new lock requests during grace period */
221  if (locks_in_grace(net)) {
222  resp->status = nlm_lck_denied_grace_period;
223  return rpc_success;
224  }
225 
226  /* Obtain client and file */
227  if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
228  return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
229 
230  /* Now try to remove the lock */
231  resp->status = cast_status(nlmsvc_unlock(net, file, &argp->lock));
232 
233  dprintk("lockd: UNLOCK status %d\n", ntohl(resp->status));
234  nlmsvc_release_host(host);
235  nlm_release_file(file);
236  return rpc_success;
237 }
238 
239 /*
240  * GRANTED: A server calls us to tell that a process' lock request
241  * was granted
242  */
243 static __be32
244 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
245  struct nlm_res *resp)
246 {
247  resp->cookie = argp->cookie;
248 
249  dprintk("lockd: GRANTED called\n");
250  resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
251  dprintk("lockd: GRANTED status %d\n", ntohl(resp->status));
252  return rpc_success;
253 }
254 
255 /*
256  * This is the generic lockd callback for async RPC calls
257  */
258 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
259 {
260  dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
261  -task->tk_status);
262 }
263 
264 void nlmsvc_release_call(struct nlm_rqst *call)
265 {
266  if (!atomic_dec_and_test(&call->a_count))
267  return;
268  nlmsvc_release_host(call->a_host);
269  kfree(call);
270 }
271 
272 static void nlmsvc_callback_release(void *data)
273 {
274  nlmsvc_release_call(data);
275 }
276 
277 static const struct rpc_call_ops nlmsvc_callback_ops = {
278  .rpc_call_done = nlmsvc_callback_exit,
279  .rpc_release = nlmsvc_callback_release,
280 };
281 
282 /*
283  * `Async' versions of the above service routines. They aren't really,
284  * because we send the callback before the reply proper. I hope this
285  * doesn't break any clients.
286  */
287 static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
288  __be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res *))
289 {
290  struct nlm_host *host;
291  struct nlm_rqst *call;
292  __be32 stat;
293 
294  host = nlmsvc_lookup_host(rqstp,
295  argp->lock.caller,
296  argp->lock.len);
297  if (host == NULL)
298  return rpc_system_err;
299 
300  call = nlm_alloc_call(host);
301  nlmsvc_release_host(host);
302  if (call == NULL)
303  return rpc_system_err;
304 
305  stat = func(rqstp, argp, &call->a_res);
306  if (stat != 0) {
307  nlmsvc_release_call(call);
308  return stat;
309  }
310 
311  call->a_flags = RPC_TASK_ASYNC;
312  if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
313  return rpc_system_err;
314  return rpc_success;
315 }
316 
317 static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
318  void *resp)
319 {
320  dprintk("lockd: TEST_MSG called\n");
321  return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
322 }
323 
324 static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
325  void *resp)
326 {
327  dprintk("lockd: LOCK_MSG called\n");
328  return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
329 }
330 
331 static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
332  void *resp)
333 {
334  dprintk("lockd: CANCEL_MSG called\n");
335  return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
336 }
337 
338 static __be32
339 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
340  void *resp)
341 {
342  dprintk("lockd: UNLOCK_MSG called\n");
343  return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
344 }
345 
346 static __be32
347 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
348  void *resp)
349 {
350  dprintk("lockd: GRANTED_MSG called\n");
351  return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
352 }
353 
354 /*
355  * SHARE: create a DOS share or alter existing share.
356  */
357 static __be32
358 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
359  struct nlm_res *resp)
360 {
361  struct nlm_host *host;
362  struct nlm_file *file;
363 
364  dprintk("lockd: SHARE called\n");
365 
366  resp->cookie = argp->cookie;
367 
368  /* Don't accept new lock requests during grace period */
369  if (locks_in_grace(SVC_NET(rqstp)) && !argp->reclaim) {
370  resp->status = nlm_lck_denied_grace_period;
371  return rpc_success;
372  }
373 
374  /* Obtain client and file */
375  if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
376  return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
377 
378  /* Now try to create the share */
379  resp->status = cast_status(nlmsvc_share_file(host, file, argp));
380 
381  dprintk("lockd: SHARE status %d\n", ntohl(resp->status));
382  nlmsvc_release_host(host);
383  nlm_release_file(file);
384  return rpc_success;
385 }
386 
387 /*
388  * UNSHARE: Release a DOS share.
389  */
390 static __be32
391 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
392  struct nlm_res *resp)
393 {
394  struct nlm_host *host;
395  struct nlm_file *file;
396 
397  dprintk("lockd: UNSHARE called\n");
398 
399  resp->cookie = argp->cookie;
400 
401  /* Don't accept requests during grace period */
402  if (locks_in_grace(SVC_NET(rqstp))) {
403  resp->status = nlm_lck_denied_grace_period;
404  return rpc_success;
405  }
406 
407  /* Obtain client and file */
408  if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
409  return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
410 
411  /* Now try to unshare the file */
412  resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
413 
414  dprintk("lockd: UNSHARE status %d\n", ntohl(resp->status));
415  nlmsvc_release_host(host);
416  nlm_release_file(file);
417  return rpc_success;
418 }
419 
420 /*
421  * NM_LOCK: Create an unmonitored lock
422  */
423 static __be32
424 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
425  struct nlm_res *resp)
426 {
427  dprintk("lockd: NM_LOCK called\n");
428 
429  argp->monitor = 0; /* just clean the monitor flag */
430  return nlmsvc_proc_lock(rqstp, argp, resp);
431 }
432 
433 /*
434  * FREE_ALL: Release all locks and shares held by client
435  */
436 static __be32
437 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
438  void *resp)
439 {
440  struct nlm_host *host;
441 
442  /* Obtain client */
443  if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
444  return rpc_success;
445 
446  nlmsvc_free_host_resources(host);
447  nlmsvc_release_host(host);
448  return rpc_success;
449 }
450 
451 /*
452  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
453  */
454 static __be32
455 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
456  void *resp)
457 {
458  dprintk("lockd: SM_NOTIFY called\n");
459 
460  if (!nlm_privileged_requester(rqstp)) {
461  char buf[RPC_MAX_ADDRBUFLEN];
462  printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
463  svc_print_addr(rqstp, buf, sizeof(buf)));
464  return rpc_system_err;
465  }
466 
467  nlm_host_rebooted(argp);
468  return rpc_success;
469 }
470 
471 /*
472  * client sent a GRANTED_RES, let's remove the associated block
473  */
474 static __be32
475 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res *argp,
476  void *resp)
477 {
478  if (!nlmsvc_ops)
479  return rpc_success;
480 
481  dprintk("lockd: GRANTED_RES called\n");
482 
483  nlmsvc_grant_reply(&argp->cookie, argp->status);
484  return rpc_success;
485 }
486 
487 /*
488  * NLM Server procedures.
489  */
490 
491 #define nlmsvc_encode_norep nlmsvc_encode_void
492 #define nlmsvc_decode_norep nlmsvc_decode_void
493 #define nlmsvc_decode_testres nlmsvc_decode_void
494 #define nlmsvc_decode_lockres nlmsvc_decode_void
495 #define nlmsvc_decode_unlockres nlmsvc_decode_void
496 #define nlmsvc_decode_cancelres nlmsvc_decode_void
497 #define nlmsvc_decode_grantedres nlmsvc_decode_void
498 
499 #define nlmsvc_proc_none nlmsvc_proc_null
500 #define nlmsvc_proc_test_res nlmsvc_proc_null
501 #define nlmsvc_proc_lock_res nlmsvc_proc_null
502 #define nlmsvc_proc_cancel_res nlmsvc_proc_null
503 #define nlmsvc_proc_unlock_res nlmsvc_proc_null
504 
505 struct nlm_void { int dummy; };
506 
507 #define PROC(name, xargt, xrest, argt, rest, respsize) \
508  { .pc_func = (svc_procfunc) nlmsvc_proc_##name, \
509  .pc_decode = (kxdrproc_t) nlmsvc_decode_##xargt, \
510  .pc_encode = (kxdrproc_t) nlmsvc_encode_##xrest, \
511  .pc_release = NULL, \
512  .pc_argsize = sizeof(struct nlm_##argt), \
513  .pc_ressize = sizeof(struct nlm_##rest), \
514  .pc_xdrressize = respsize, \
515  }
516 
517 #define Ck (1+XDR_QUADLEN(NLM_MAXCOOKIELEN)) /* cookie */
518 #define St 1 /* status */
519 #define No (1+1024/4) /* Net Obj */
520 #define Rg 2 /* range - offset + size */
521 
522 struct svc_procedure nlmsvc_procedures[] = {
523  PROC(null, void, void, void, void, 1),
524  PROC(test, testargs, testres, args, res, Ck+St+2+No+Rg),
525  PROC(lock, lockargs, res, args, res, Ck+St),
526  PROC(cancel, cancargs, res, args, res, Ck+St),
527  PROC(unlock, unlockargs, res, args, res, Ck+St),
528  PROC(granted, testargs, res, args, res, Ck+St),
529  PROC(test_msg, testargs, norep, args, void, 1),
530  PROC(lock_msg, lockargs, norep, args, void, 1),
531  PROC(cancel_msg, cancargs, norep, args, void, 1),
532  PROC(unlock_msg, unlockargs, norep, args, void, 1),
533  PROC(granted_msg, testargs, norep, args, void, 1),
534  PROC(test_res, testres, norep, res, void, 1),
535  PROC(lock_res, lockres, norep, res, void, 1),
536  PROC(cancel_res, cancelres, norep, res, void, 1),
537  PROC(unlock_res, unlockres, norep, res, void, 1),
538  PROC(granted_res, res, norep, res, void, 1),
539  /* statd callback */
540  PROC(sm_notify, reboot, void, reboot, void, 1),
541  PROC(none, void, void, void, void, 1),
542  PROC(none, void, void, void, void, 1),
543  PROC(none, void, void, void, void, 1),
544  PROC(share, shareargs, shareres, args, res, Ck+St+1),
545  PROC(unshare, shareargs, shareres, args, res, Ck+St+1),
546  PROC(nm_lock, lockargs, res, args, res, Ck+St),
547  PROC(free_all, notify, void, args, void, 0),
548 
549 };
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