Root/fs/lockd/svcproc.c

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

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